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Sample records for hydrides varies azimuthally

  1. Depth-varying azimuthal anisotropy in the Tohoku subduction channel

    Science.gov (United States)

    Liu, Xin; Zhao, Dapeng

    2017-09-01

    We determine a detailed 3-D model of azimuthal anisotropy tomography of the Tohoku subduction zone from the Japan Trench outer-rise to the back-arc near the Japan Sea coast, using a large number of high-quality P and S wave arrival-time data of local earthquakes recorded by the dense seismic network on the Japan Islands. Depth-varying seismic azimuthal anisotropy is revealed in the Tohoku subduction channel. The shallow portion of the Tohoku megathrust zone (plate mainly exhibits trench-parallel FVDs, except for the top portion of the subducting Pacific slab where visible trench-normal FVDs are revealed. A qualitative tectonic model is proposed to interpret such anisotropic features, suggesting transposition of earlier fabrics in the oceanic lithosphere into subduction-induced new structures in the subduction channel.

  2. Anisotropic Azimuthal Power and Temperature distribution on FuelRod. Impact on Hydride Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Arthur [Pennsylvania State Univ., State College, PA (United States); Ivanov, Kostadin [Pennsylvania State Univ., State College, PA (United States); Arramova, Maria [Pennsylvania State Univ., State College, PA (United States); Hales, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-29

    The degradation of the zirconium cladding may limit nuclear fuel performance. In the high temperature environment of a reactor, the zirconium in the cladding corrodes, releasing hydrogen in the process. Some of this hydrogen is absorbed by the cladding in a highly inhomogeneous manner. The distribution of the absorbed hydrogen is extremely sensitive to temperature and stress concentration gradients. The absorbed hydrogen tends to concentrate near lower temperatures. This hydrogen absorption and hydride formation can cause cladding failure. This project set out to improve the hydrogen distribution prediction capabilities of the BISON fuel performance code. The project was split into two primary sections, first was the use of a high fidelity multi-physics coupling to accurately predict temperature gradients as a function of r, θ , and z, and the second was to use experimental data to create an analytical hydrogen precipitation model. The Penn State version of thermal hydraulics code COBRA-TF (CTF) was successfully coupled to the DeCART neutronics code. This coupled system was verified by testing and validated by comparison to FRAPCON data. The hydrogen diffusion and precipitation experiments successfully calculated the heat of transport and precipitation rate constant values to be used within the hydrogen model in BISON. These values can only be determined experimentally. These values were successfully implemented in precipitation, diffusion and dissolution kernels that were implemented in the BISON code. The coupled output was fed into BISON models and the hydrogen and hydride distributions behaved as expected. Simulations were conducted in the radial, axial and azimuthal directions to showcase the full capabilities of the hydrogen model.

  3. Azimuthally Varying Noise Reduction Techniques Applied to Supersonic Jets

    Science.gov (United States)

    Heeb, Nicholas S.

    An experimental investigation into the effect of azimuthal variance of chevrons and fluidically enhanced chevrons applied to supersonic jets is presented. Flow field measurements of streamwise and cross-stream particle imaging velocimetry were employed to determine the causes of noise reduction, which was demonstrated through acoustic measurements. Results were obtained in the over- and under- expanded regimes, and at the design condition, though emphasis was placed on the overexpanded regime due to practical application. Surveys of chevron geometry, number, and arrangement were undertaken in an effort to reduce noise and/or incurred performance penalties. Penetration was found to be positively correlated with noise reduction in the overexpanded regime, and negatively correlated in underexpanded operation due to increased effective penetration and high frequency penalty, respectively. The effect of arrangement indicated the beveled configuration achieved optimal abatement in the ideally and underexpanded regimes due to superior BSAN reduction. The symmetric configuration achieved optimal overexpanded noise reduction due to LSS suppression from improved vortex persistence. Increases in chevron number generally improved reduction of all noise components for lower penetration configurations. Higher penetration configurations reached levels of saturation in the four chevron range, with the potential to introduce secondary shock structures and generate additional noise with higher number. Alternation of penetration generated limited benefit, with slight reduction of the high frequency penalty caused by increased shock spacing. The combination of alternating penetration with beveled and clustered configurations achieved comparable noise reduction to the standard counterparts. Analysis of the entire data set indicated initial improvements with projected area that saturated after a given level and either plateaued or degraded with additional increases. Optimal reductions

  4. High Frequency Asymptotic Methods for Traveltimes and Anisotropy Parameter Estimation in Azimuthally Varying Media

    KAUST Repository

    Masmoudi, Nabil

    2014-05-01

    anellipticity parameter and the symmetry axis azimuth in inhomogeneous background media. Specifically, our expansion assumes an inhomogeneous elliptically anisotropic background medium, which may be obtained from well information and stacking velocity analysis in HTI media. This formulation has advantages on two fronts: on one hand, it alleviates the computational complexity associated with solving the HTI eikonal equation, and on the other hand, it provides a mechanism to scan for the best fitting parameters without the need for repetitive modeling of traveltimes, because the traveltime coefficients of the expansion are independent of the perturbed parameters.

  5. Waggle Dances and Azimuthal Windows

    Directory of Open Access Journals (Sweden)

    O. Duangphakdee

    2011-01-01

    Full Text Available Because the waggle dances of honeybees contain celestial components, modifications of the dances occur with changing celestial moves relative to a honeybee nest. Since the direction of a particular resource is static, the dances must alter to compensate for the sun's passage. The position of the sun is seasonal between the Tropics of Cancer and Capricorn so that turns at the end of waggle runs will vary with season and latitude. The bees are confronted with a new difficulty when the sun closely approaches its zenith because only slight errors in the bees' estimation of the relative positions of the sun and zenith generate very large errors. So, the sun compass loses its usefulness when at its zenith. We review experiments and observations on both foraging and absconding in relation to the azimuth. The honeybees' solution for the paradox of the azimuth includes an azimuthal lull, preferences, and time windows.

  6. Web life: Azimuth

    Science.gov (United States)

    2016-09-01

    Azimuth is an interesting hybrid. In part, it's the personal blog of John Carlos Baez, a mathematical physicist at the University of California, Riverside, whose current research focuses mainly on network theory.

  7. Boron Hydrides

    Science.gov (United States)

    1946-07-01

    of direct interest could be b.P.4d. ’Thus the discovory of a now proj.ect, since silano is probably too readily infla-zmablo for practical usc’ this...devoted, ho specc4fie compounds vhitih a’-ould be tocdte at prescnt arc: nron tiy * silano , %;2.SiFi3 , diothyl sila~no, (C2 115 )2 Si112, mono r.-rop; ! (n...Bcrohydrido or Li h.... I .A-4A- The prepuation of Silano med of Stannane by the interaction or lithium aluzirun hydride v-ithl silicon tetrtchiorido and

  8. Fundamental experiments on hydride reorientation in zircaloy

    Science.gov (United States)

    Colas, Kimberly B.

    remain constant in the tensile direction during the second precipitation regime. This could be due to the fact that the face of reoriented hydride platelet is in compression once these platelets have grown to a sufficient size. The second goal of this study was to perform a spatially resolved study of the effect of a stress concentration such as a notch or a crack on hydride reorientation. Using SEM and image analysis, it was found that a sharp crack induces a different hydride microstructure than a blunt notch. In the case of sharp crack, hydrides are more localized and align more with the defect than for blunt notches. The hydride connectivity also increases close to a stress concentration which will assist in crack propagation during DHC. Using TEM, the microstructure of hydrides grown near crack tips were observed to be similar to that of circumferential hydrides grown in the bulk. The orientation relationship studied with SEM and micro-X-ray diffraction was found to be in most cases δ(111)// α(0002) for hydrides grown both near and far from stress concentrations. Using the same micro-X-ray diffraction technique local hydride and matrix elastic strains were measured and observed to vary significantly from grain to grain. It was however observed that hydrides grown close to the stress concentration are in tension in the face of the platelet, similar to reoriented hydrides, while those grown far from the stress concentration are in tension, similar to circumferential hydrides. The orders of magnitude of the measured strains in the hydrides and the zirconium matrix compared well to those predicted by finite element models. This study shows that it is possible to study hydride dissolution and precipitation in-situ using time-dependent techniques. It was found that the precipitation temperature is lowered by hydride reorientation. The evolution of hydride strains during precipitation was found to be different for unstressed, stressed and reoriented hydrides. The

  9. Advanced Hydride Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, T.

    1989-01-01

    Metal hydrides have been used at the Savannah River Tritium Facilities since 1984. However, the most extensive application of metal hydride technology at the Savannah River Site is being planned for the Replacement Tritium Facility, a $140 million facility schedules for completion in 1990 and startup in 1991. In the new facility, metal hydride technology will be used to store, separate, isotopically purify, pump, and compress hydrogen isotopes. In support of the Replacement Tritium Facility, a $3.2 million, cold,'' process demonstration facility, the Advanced Hydride Laboratory began operation in November of 1987. The purpose of the Advanced Hydride Laboratory is to demonstrate the Replacement Tritium Facility's metal hydride technology by integrating the various unit operations into an overall process. This paper will describe the Advanced Hydride Laboratory, its role and its impact on the application of metal hydride technology to tritium handling.

  10. Advanced Hydride Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, T.

    1989-12-31

    Metal hydrides have been used at the Savannah River Tritium Facilities since 1984. However, the most extensive application of metal hydride technology at the Savannah River Site is being planned for the Replacement Tritium Facility, a $140 million facility schedules for completion in 1990 and startup in 1991. In the new facility, metal hydride technology will be used to store, separate, isotopically purify, pump, and compress hydrogen isotopes. In support of the Replacement Tritium Facility, a $3.2 million, ``cold,`` process demonstration facility, the Advanced Hydride Laboratory began operation in November of 1987. The purpose of the Advanced Hydride Laboratory is to demonstrate the Replacement Tritium Facility`s metal hydride technology by integrating the various unit operations into an overall process. This paper will describe the Advanced Hydride Laboratory, its role and its impact on the application of metal hydride technology to tritium handling.

  11. Erbium hydride decomposition kinetics.

    Energy Technology Data Exchange (ETDEWEB)

    Ferrizz, Robert Matthew

    2006-11-01

    Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

  12. Multiparticle azimuthal correlations

    Indian Academy of Sciences (India)

    N Borghini; P M Dinh; J-Y Ollitrault

    2003-04-01

    First observations of elliptic flow in Au–Au collisions at RHIC have been interpreted as evidence that the colliding system reaches thermal equilibrium. We discuss some of the arguments leading to this conclusion and show that a more accurate analysis is needed, which the standard flow analysis may not provide. We then present a new method of flow analysis, based on a systematic study of multiparticle azimuthal correlations. This method allows one to test quantitatively the collective behaviour of the interacting system. It has recently been applied by the STAR Collaboration at RHIC.

  13. Technology of optical azimuth transmission

    Science.gov (United States)

    Lu, Honggang; Hu, Chunsheng; Wang, Xingshu; Gao, Yang

    2012-11-01

    It often needs transfer a reference from one place to another place in aerospace and guided missile launching. At first, principles of several typical optical azimuth transmission methods are presented. Several typical methods are introduced, such as Theodolite (including gyro-theodolite) collimation method, Camera series method, Optical apparatus for azimuth method and polarization modulated light transmission method. For these typical azimuth transmission methods, their essential theories are elaborated. Then the devices, the application fields and limitations of these typical methods' are presented. Theodolite (including gyro-theodolite) collimation method is used in the ground assembly of spacecraft. Camera series method and optical apparatus for azimuth method are used in azimuth transmission between different decks of ship. Polarization modulated light transmission method is used in azimuth transmission of rocket and guided missile. At the last, the further developments of these methods are discussed.

  14. Synthesis of ruthenium hydride

    Science.gov (United States)

    Kuzovnikov, M. A.; Tkacz, M.

    2016-02-01

    Ruthenium hydride was synthesized at a hydrogen pressure of about 14 GPa in a diamond-anvil cell. Energy-dispersive x-ray diffraction was used to monitor the ruthenium crystal structure as a function of hydrogen pressure up to 30 GPa. The hydride formation was accompanied by phase transition from the original hcp structure of the pristine metal to the fcc structure. Our results confirmed the theoretical prediction of ruthenium hydride formation under hydrogen pressure. The standard Gibbs free energy of the ruthenium hydride formation reaction was calculated assuming the pressure of decomposition as the equilibrium pressure.

  15. Hysteresis in Metal Hydrides.

    Science.gov (United States)

    Flanagan, Ted B., And Others

    1987-01-01

    This paper describes a reproducible process where the irreversibility can be readily evaluated and provides a thermodynamic description of the important phenomenon of hysteresis. A metal hydride is used because hysteresis is observed during the formation and decomposition of the hydride phase. (RH)

  16. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  17. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  18. Multidimensional simulations of hydrides during fuel rod lifecycle

    Science.gov (United States)

    Stafford, D. S.

    2015-11-01

    In light water reactor fuel rods, waterside corrosion of zirconium-alloy cladding introduces hydrogen into the cladding, where it is slightly soluble. When the solubility limit is reached, the hydrogen precipitates into crystals of zirconium hydride which decrease the ductility of the cladding and may lead to cladding failure during dry storage or transportation events. The distribution of the hydride phase and the orientation of the crystals depend on the history of the spatial temperature and stress profiles in the cladding. In this work, we have expanded the existing hydride modeling capability in the BISON fuel performance code with the goal of predicting both global and local effects on the radial, azimuthal and axial distribution of the hydride phase. We compare results from 1D simulations to published experimental data. We demonstrate the new capability by simulating in 2D a fuel rod throughout a lifecycle that includes irradiation, short-term storage in the spent fuel pool, drying, and interim storage in a dry cask. Using the 2D simulations, we present qualitative predictions of the effects of the inter-pellet gap and the drying conditions on the growth of a hydride rim.

  19. Lightweight hydride storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.J.; Guthrie, S.E.; Bauer, W. [Sandia National Labs., Livermore, CA (United States)

    1995-09-01

    The need for lightweight hydrides in vehicular applications has prompted considerable research into the use of magnesium and its alloys. Although this earlier work has provided some improved performance in operating temperature and pressure, substantial improvements are needed before these materials will significantly enhance the performance of an engineered system on a vehicle. We are extending the work of previous investigators on Mg alloys to reduce the operating temperature and hydride heat of formation in light weight materials. Two important results will be discussed in this paper: (1) a promising new alloy hydride was found which has better pressure-temperature characteristics than any previous Mg alloy and, (2) a new fabrication process for existing Mg alloys was developed and demonstrated. The new alloy hydride is composed of magnesium, aluminum and nickel. It has an equilibrium hydrogen overpressure of 1.3 atm. at 200{degrees}C and a storage capacity between 3 and 4 wt.% hydrogen. A hydrogen release rate of approximately 5 x 10{sup -4} moles-H{sub 2}/gm-min was measured at 200{degrees}C. The hydride heat of formation was found to be 13.5 - 14 kcal/mole-H{sub 2}, somewhat lower than Mg{sub 2}Ni. The new fabrication method takes advantage of the high vapor transport of magnesium. It was found that Mg{sub 2}Ni produced by our low temperature process was better than conventional materials because it was single phase (no Mg phase) and could be fabricated with very small particle sizes. Hydride measurements on this material showed faster kinetic response than conventional material. The technique could potentially be applied to in-situ hydride bed fabrication with improved packing density, release kinetics, thermal properties and mechanical stability.

  20. Three-Particle Azimuthal Correlations

    CERN Document Server

    Ulery, J G

    2007-01-01

    Two-particle azimuthal correlations reveal broadened and softened away-side correlations. Several different physics mechanisms are possible: large angle gluon radiation, deflected jets, and conical flow or Cerenkov radiation. Three-particle correlations are investigated to try to discriminate these mechanisms. We present results on 3-particle azimuthal correlations between a trigger particle of 3

  1. Detection of coalbed fractures with P-wave azimuthal AVO in 3-D seismic exploration

    Institute of Scientific and Technical Information of China (English)

    LI Guofa; PENG Suping; HE Bingshou; PENG Xiaobo; YUAN Chunfang; HU Chaoyuan

    2005-01-01

    The detection of fractures is important for production and safety in coal fields. Subsurface fractures result in azimuthal anisotropy of the seismic wave, and the amplitude of reflection wave varies with offset and azimuth.In case of weak anisotropy, the reflection coefficients of P-wave are concisely denoted as the analytic function of fracture parameters. For the purpose of predicting the coalbed fracture distribution through analyzing variation of the reflection amplitudes with offset and azimuth, 3-D seismic data with full-azimuth were acquired in a coal field in Huainan, Anhui Province. The careful analysis and process of seismic data showed that the reflection amplitude of the primary coaibed varied with azimuth in much consistent with the theoretical model. The conclusion was drawn that the coal-bed fracture in this coal field could be predicted through the method of the P-wave azimuthal AVO.

  2. Hydrogen, lithium, and lithium hydride production

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.; Powell, G. Louis; Campbell, Peggy J.

    2017-06-20

    A method is provided for extracting hydrogen from lithium hydride. The method includes (a) heating lithium hydride to form liquid-phase lithium hydride; (b) extracting hydrogen from the liquid-phase lithium hydride, leaving residual liquid-phase lithium metal; (c) hydriding the residual liquid-phase lithium metal to form refined lithium hydride; and repeating steps (a) and (b) on the refined lithium hydride.

  3. Image Currents in Azimuthally Inhomogeneous Metallic Beam Pipes

    CERN Document Server

    Caspers, Friedhelm; Palumbo, L; Ruggiero, F

    2001-01-01

    We consider an ultra-relativistic particle travelling on-axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. A semi-analytical solution, obtained by applying approximate boundary conditions, predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. We discuss numerical simulations and bench measurements which confirm the theoretical predictions. Implications for the beam-induced ohmic losses in the copper coated, welded LHC beam screen are also addressed.

  4. Image currents in azimuthally inhomogeneous metallic beam pipes

    Directory of Open Access Journals (Sweden)

    A. Mostacci

    2005-08-01

    Full Text Available We consider an ultrarelativistic particle traveling on axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. For a circular geometry, a semianalytical solution is obtained using the Green functions and applying approximate boundary conditions for conductors. The theory predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. Numerical electromagnetic simulations and bench measurements confirm the theoretical predictions. Implications for the beam-induced heating in the copper-coated, welded LHC beam screen are also addressed.

  5. Drilling azimuth gamma embedded design

    Directory of Open Access Journals (Sweden)

    Zhou Yi Ren

    2016-01-01

    Full Text Available Embedded drilling azimuth gamma design, the use of radioactive measuring principle embedded gamma measurement while drilling a short section analysis. Monte Carlo method, in response to the density of horizontal well logging numerical simulation of 16 orientation, the orientation of horizontal well analysed, calliper, bed boundary location, space, different formation density, formation thickness, and other factors inclined strata dip the impact by simulating 137Cs sources under different formation conditions of the gamma distribution, to determine the orientation of drilling density tool can detect window size and space, draw depth of the logging methods. The data 360° azimuth imaging, image processing method to obtain graph, display density of the formation, dip and strata thickness and other parameters, the logging methods obtain real-time geo-steering. To establish a theoretical basis for the orientation density logging while drilling method implementation and application of numerical simulation in-depth study of the MWD azimuth and density log response factors of horizontal wells.

  6. Air and metal hydride battery

    Energy Technology Data Exchange (ETDEWEB)

    Lampinen, M.; Noponen, T. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Applied Thermodynamics

    1998-12-31

    The main goal of the air and metal hydride battery project was to enhance the performance and manufacturing technology of both electrodes to such a degree that an air-metal hydride battery could become a commercially and technically competitive power source for electric vehicles. By the end of the project it was possible to demonstrate the very first prototype of the air-metal hydride battery at EV scale, achieving all the required design parameters. (orig.)

  7. Hydrogen Outgassing from Lithium Hydride

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, L N; Schildbach, M A; Smith, R A; Balazs1, B; McLean II, W

    2006-04-20

    Lithium hydride is a nuclear material with a great affinity for moisture. As a result of exposure to water vapor during machining, transportation, storage and assembly, a corrosion layer (oxide and/or hydroxide) always forms on the surface of lithium hydride resulting in the release of hydrogen gas. Thermodynamically, lithium hydride, lithium oxide and lithium hydroxide are all stable. However, lithium hydroxides formed near the lithium hydride substrate (interface hydroxide) and near the sample/vacuum interface (surface hydroxide) are much less thermally stable than their bulk counterpart. In a dry environment, the interface/surface hydroxides slowly degenerate over many years/decades at room temperature into lithium oxide, releasing water vapor and ultimately hydrogen gas through reaction of the water vapor with the lithium hydride substrate. This outgassing can potentially cause metal hydriding and/or compatibility issues elsewhere in the device. In this chapter, the morphology and the chemistry of the corrosion layer grown on lithium hydride (and in some cases, its isotopic cousin, lithium deuteride) as a result of exposure to moisture are investigated. The hydrogen outgassing processes associated with the formation and subsequent degeneration of this corrosion layer are described. Experimental techniques to measure the hydrogen outgassing kinetics from lithium hydride and methods employing the measured kinetics to predict hydrogen outgassing as a function of time and temperature are presented. Finally, practical procedures to mitigate the problem of hydrogen outgassing from lithium hydride are discussed.

  8. Azimuthal decomposition of optical modes

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2012-07-01

    Full Text Available of Optical Modes Angela Dudley1, Igor Litvin1, Filippus S. Roux1 and Andrew Forbes1,2,3 1 CSIR National Laser Centre, Pretoria, South Africa 2 School of Physics, University of KwaZulu-Natal, Durban, South Africa 3 Laser Research Institute, University... of Stellenbosch, Stellenbosch, South Africa Presented at the 2012 South African Institute of Physics Conference University of Pretoria Pretoria, South Africa 12 July 2012 To decompose the azimuthal modes we need two steps: generation and decomposition...

  9. Metal Hydrides for High-Temperature Power Generation

    Directory of Open Access Journals (Sweden)

    Ewa C. E. Rönnebro

    2015-08-01

    Full Text Available Metal hydrides can be utilized for hydrogen storage and for thermal energy storage (TES applications. By using TES with solar technologies, heat can be stored from sun energy to be used later, which enables continuous power generation. We are developing a TES technology based on a dual-bed metal hydride system, which has a high-temperature (HT metal hydride operating reversibly at 600–800 °C to generate heat, as well as a low-temperature (LT hydride near room temperature that is used for hydrogen storage during sun hours until there is the need to produce electricity, such as during night time, a cloudy day or during peak hours. We proceeded from selecting a high-energy density HT-hydride based on performance characterization on gram-sized samples scaled up to kilogram quantities with retained performance. COMSOL Multiphysics was used to make performance predictions for cylindrical hydride beds with varying diameters and thermal conductivities. Based on experimental and modeling results, a ~200-kWh/m3 bench-scale prototype was designed and fabricated, and we demonstrated the ability to meet or exceed all performance targets.

  10. Complete azimuthal decomposition of optical fields

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2013-02-01

    Full Text Available By using digital holograms, we present a simple technique for performing a complete azimuthal decomposition of an arbitrary laser mode. The match-filter, used to perform the azimuthal decomposition, is bounded by an annular ring, allowing us...

  11. Metal Hydride Compression

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bowman, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Barton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anovitz, Lawrence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jensen, Craig [Hawaii Hydrogen Carriers LLC, Honolulu, HI (United States)

    2017-07-01

    Conventional hydrogen compressors often contribute over half of the cost of hydrogen stations, have poor reliability, and have insufficient flow rates for a mature FCEV market. Fatigue associated with their moving parts including cracking of diaphragms and failure of seal leads to failure in conventional compressors, which is exacerbated by the repeated starts and stops expected at fueling stations. Furthermore, the conventional lubrication of these compressors with oil is generally unacceptable at fueling stations due to potential fuel contamination. Metal hydride (MH) technology offers a very good alternative to both conventional (mechanical) and newly developed (electrochemical, ionic liquid pistons) methods of hydrogen compression. Advantages of MH compression include simplicity in design and operation, absence of moving parts, compactness, safety and reliability, and the possibility to utilize waste industrial heat to power the compressor. Beyond conventional H2 supplies of pipelines or tanker trucks, another attractive scenario is the on-site generating, pressuring and delivering pure H2 at pressure (≥ 875 bar) for refueling vehicles at electrolysis, wind, or solar generating production facilities in distributed locations that are too remote or widely distributed for cost effective bulk transport. MH hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas to form the MH phase and is a promising process for hydrogen energy applications [1,2]. To deliver hydrogen continuously, each stage of the compressor must consist of multiple MH beds with synchronized hydrogenation & dehydrogenation cycles. Multistage pressurization allows achievement of greater compression ratios using reduced temperature swings compared to single stage compressors. The objectives of this project are to investigate and demonstrate on a laboratory scale a two-stage MH hydrogen (H2) gas compressor with a

  12. The azimuthal magnetorotational instability (AMRI)

    CERN Document Server

    Ruediger, G; Schultz, M; Hollerbach, R; Stefani, F

    2013-01-01

    We consider the interaction of differential rotation and toroidal fields that are current-free in the gap between two corotating axially unbounded cylinders. It is shown that nonaxisymmetric perturbations are unstable if the rotation rate and Alfven frequency of the field are of the same order almost independent of the magnetic Prandtl number Pm. For the very steep rotation law \\Omega\\propto R^{-2} (the Rayleigh limit) this Azimuthal MagnetoRotational Instability (AMRI) scales with the ordinary Reynolds number and the Hartmann number, which allows a laboratory experiment with liquid metals like sodium or gallium in a Taylor-Couette container. The growth rate of AMRI scales with \\Omega^2 in the low-conductivity limit and with \\Omega in the high-conductivity limit. For the weakly nonlinear system the numerical values of the kinetic energy and the magnetic energy are derived for magnetic Prandtl numbers between 0.05 and unity. We find that the magnetic energy scales with the magnetic Reynolds number Rm, while th...

  13. Hydride development for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.J.; Guthrie, S.E.; Bauer, W.; Yang, N.Y.C. [Sandia National Lab., Livermore, CA (United States); Sandrock, G. [SunaTech, Inc., Ringwood, NJ (United States)

    1996-10-01

    The purpose of this project is to develop and demonstrate improved hydride materials for hydrogen storage. The work currently is organized into four tasks: hydride development, bed fabrication, materials support for engineering systems, and IEA Annex 12 activities. At the present time, hydride development is focused on Mg alloys. These materials generally have higher weight densities for storing hydrogen than rare earth or transition metal alloys, but suffer from high operating temperatures, slow kinetic behavior and material stability. The authors approach is to study bulk alloy additions which increase equilibrium overpressure, in combination with stable surface alloy modification and particle size control to improve kinetic properties. This work attempts to build on the considerable previous research in this area, but examines specific alloy systems in greater detail, with attention to known phase properties and structures. The authors have found that specific phases can be produced which have significantly improved hydride properties compared to previous studies.

  14. Metal hydride air conditioner

    Institute of Scientific and Technical Information of China (English)

    YANG; Ke; DU; Ping; LU; Man-qi

    2005-01-01

    The relationship among the hydrogen storage properties, cycling characteristics and thermal parameters of the metal hydride air conditioning systems was investigated. Based on a new alloy selection model, three pairs of hydrogen storage alloys, LaNi4.4 Mn0.26 Al0.34 / La0.6 Nd0.4 Ni4.8 Mn0.2 Cu0. 1, LaNi4.61Mn0. 26 Al0.13/La0.6 Nd0.4 Ni4.8 Mn0.2 Cu0. 1 and LaNi4.61 Mn0.26 Al0.13/La0.6 Y0.4 Ni4.8 Mn0. 2, were selected as the working materials for the metal hydride air conditioning system. Studies on the factors affecting the COP of the system showed that higher COP and available hydrogen content need the proper operating temperature and cycling time,large hydrogen storage capacity, flat plateau and small hysterisis of hydrogen alloys, proper original input hydrogen content and mass ratio of the pair of alloys. It also needs small conditioning system was established by using LaNi4.61 Mn0.26 Al0. 13/La0.6 Y0.4 Ni4.8 Mn0.2 alloys as the working materials, which showed that under the operating temperature of 180℃/40℃, a low temperature of 13℃ was reached, with COP =0.38 and Wnet =0.09 kW/kg.

  15. Geoneutrino and Hydridic Earth model

    CERN Document Server

    Bezrukov, Leonid

    2013-01-01

    Uranium, Thorium and Potassium-40 abundances in the Earth were calculated in the frame of Hydridic Earth model. Terrestrial heat producton from U, Th and K40 decays was calculated also. We must admit the existance of Earth expansion process to understand the obtained large value of terrestrial heat producton. The geoneutrino detector with volume more than 5 kT (LENA type) must be constructed to definitely separate between Bulk Silicat Earth model and Hydridic Earth model.

  16. Physics of hydride fueled PWR

    Science.gov (United States)

    Ganda, Francesco

    The first part of the work presents the neutronic results of a detailed and comprehensive study of the feasibility of using hydride fuel in pressurized water reactors (PWR). The primary hydride fuel examined is U-ZrH1.6 having 45w/o uranium: two acceptable design approaches were identified: (1) use of erbium as a burnable poison; (2) replacement of a fraction of the ZrH1.6 by thorium hydride along with addition of some IFBA. The replacement of 25 v/o of ZrH 1.6 by ThH2 along with use of IFBA was identified as the preferred design approach as it gives a slight cycle length gain whereas use of erbium burnable poison results in a cycle length penalty. The feasibility of a single recycling plutonium in PWR in the form of U-PuH2-ZrH1.6 has also been assessed. This fuel was found superior to MOX in terms of the TRU fractional transmutation---53% for U-PuH2-ZrH1.6 versus 29% for MOX---and proliferation resistance. A thorough investigation of physics characteristics of hydride fuels has been performed to understand the reasons of the trends in the reactivity coefficients. The second part of this work assessed the feasibility of multi-recycling plutonium in PWR using hydride fuel. It was found that the fertile-free hydride fuel PuH2-ZrH1.6, enables multi-recycling of Pu in PWR an unlimited number of times. This unique feature of hydride fuels is due to the incorporation of a significant fraction of the hydrogen moderator in the fuel, thereby mitigating the effect of spectrum hardening due to coolant voiding accidents. An equivalent oxide fuel PuO2-ZrO2 was investigated as well and found to enable up to 10 recycles. The feasibility of recycling Pu and all the TRU using hydride fuels were investigated as well. It was found that hydride fuels allow recycling of Pu+Np at least 6 times. If it was desired to recycle all the TRU in PWR using hydrides, the number of possible recycles is limited to 3; the limit is imposed by positive large void reactivity feedback.

  17. A New Reducing Regent: Dichloroindium Hydride

    Institute of Scientific and Technical Information of China (English)

    A. BABA; I. SHIBATA; N. HAYASHI

    2005-01-01

    @@ 1Introduction Among the hydride derivatives of group 13 elements, various types of aluminum hydrides and boron hydrides have been employed as powerful reduction tools. Indium hydrides have not received much attention,whereas the synthesis of indium trihydride (InH3) was reported several decades ago[1]. There have been no precedents for monometallic indium hydrides having practical reactivity, while activated hydrides such as an ate complex LiPhn InH4-n (n = 0- 2) and phosphine-coordinated indium hydrides readily reduce carbonyl compounds. In view of this background, we focused on the development of dichloroindium hydrides (Cl2InH) as novel reducing agents that bear characteristic features in both ionic and radical reactions.

  18. Hydride Olefin complexes of tantalum and niobium

    NARCIS (Netherlands)

    Klazinga, Aan Hendrik

    1979-01-01

    This thesis describes investigations on low-valent tantalum and niobium hydride and alkyl complexes, particularly the dicyclopentadienyl tantalum hydride olefin complexes Cp2Ta(H)L (L=olefin). ... Zie: Summary

  19. Complex and liquid hydrides for energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Callini, Elsa; Atakli, Zuleyha Özlem Kocabas; Hauback, Bjørn C.; Orimo, Shin-ichi; Jensen, Craig; Dornheim, Martin; Grant, David; Cho, Young Whan; Chen, Ping; Hjörvarsson, Bjørgvin; de Jongh, Petra; Weidenthaler, Claudia; Baricco, Marcello; Paskevicius, Mark; Jensen, Torben R.; Bowden, Mark E.; Autrey, Thomas S.; Züttel, Andreas

    2016-03-10

    The research on complex hydrides for hydrogen storage was imitated by the discovery of Ti as a hydrogen sorption catalyst in NaAlH4 by Boris Bogdanovic in 1996. A large number of new complex hydride materials in various forms and combinations have been synthesized and characterized and the knowledge on the properties of complex hydrides and the synthesis methods has grown enormously since then. A significant part of the research groups active in the field of complex hydrides are collaborators in the IEA task 32. This paper reports about the important issues in the field of the complex hydride research, i.e. the synthesis of borohydrides, the thermodynamics of complex hydrides and their thermodynamic properties, the effects of size and confinement, the hydrogen sorption mechanism and the complex hydride composites as well as the properties of liquid complex hydrides. This paper is the result of the collaboration of several groups and excellent summary of the recent achievements.

  20. Luminescent properties of aluminum hydride

    Energy Technology Data Exchange (ETDEWEB)

    Baraban, A.P.; Gabis, I.E.; Dmitriev, V.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Dobrotvorskii, M.A., E-mail: mstislavd@gmail.com [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Kuznetsov, V.G. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Matveeva, O.P. [National Mineral Resources University, Saint Petersburg 199106 (Russian Federation); Titov, S.A. [Petersburg State University of Railway Transport, Saint-Petersburg 190031 (Russian Federation); Voyt, A.P.; Elets, D.I. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation)

    2015-10-15

    We studied cathodoluminescence and photoluminescence of α-AlH{sub 3}– a likely candidate for use as possible hydrogen carrier in hydrogen-fueled vehicles. Luminescence properties of original α-AlH{sub 3} and α-AlH{sub 3} irradiated with ultraviolet were compared. The latter procedure leads to activation of thermal decomposition of α-AlH{sub 3} and thus has a practical implementation. We showed that the original and UV-modified aluminum hydride contain luminescence centers ‐ structural defects of the same type, presumably hydrogen vacancies, characterized by a single set of characteristic bands of radiation. The observed luminescence is the result of radiative intracenter relaxation of the luminescence center (hydrogen vacancy) excited by electrons or photons, and its intensity is defined by the concentration of vacancies, and the area of their possible excitation. UV-activation of the dehydrogenation process of aluminum hydride leads to changes in the spatial distribution of the luminescence centers. For short times of exposure their concentration increases mainly in the surface regions of the crystals. At high exposures, this process extends to the bulk of the aluminum hydride and ends with a decrease in concentration of luminescence centers in the surface region. - Highlights: • Aluminum hydride contains hydrogen vacancies which serve as luminescence centers. • The luminescence is the result of radiative relaxation of excited centers. • Hydride UV-irradiation alters distribution and concentration of luminescence centers.

  1. Photochemistry of Transition Metal Hydrides.

    Science.gov (United States)

    Perutz, Robin N; Procacci, Barbara

    2016-08-10

    Photochemical reactivity associated with metal-hydrogen bonds is widespread among metal hydride complexes and has played a critical part in opening up C-H bond activation. It has been exploited to design different types of photocatalytic reactions and to obtain NMR spectra of dilute solutions with a single pulse of an NMR spectrometer. Because photolysis can be performed on fast time scales and at low temperature, metal-hydride photochemistry has enabled determination of the molecular structure and rates of reaction of highly reactive intermediates. We identify five characteristic photoprocesses of metal monohydride complexes associated with the M-H bond, of which the most widespread are M-H homolysis and R-H reductive elimination. For metal dihydride complexes, the dominant photoprocess is reductive elimination of H2. Dihydrogen complexes typically lose H2 photochemically. The majority of photochemical reactions are likely to be dissociative, but hydride complexes may be designed with equilibrated excited states that undergo different photochemical reactions, including proton transfer or hydride transfer. The photochemical mechanisms of a few reactions have been analyzed by computational methods, including quantum dynamics. A section on specialist methods (time-resolved spectroscopy, matrix isolation, NMR, and computational methods) and a survey of transition metal hydride photochemistry organized by transition metal group complete the Review.

  2. Method of producing a chemical hydride

    Science.gov (United States)

    Klingler, Kerry M.; Zollinger, William T.; Wilding, Bruce M.; Bingham, Dennis N.; Wendt, Kraig M.

    2007-11-13

    A method of producing a chemical hydride is described and which includes selecting a composition having chemical bonds and which is capable of forming a chemical hydride; providing a source of a hydrocarbon; and reacting the composition with the source of the hydrocarbon to generate a chemical hydride.

  3. Hydrogen, lithium, and lithium hydride production

    Science.gov (United States)

    Brown, Sam W; Spencer, Larry S; Phillips, Michael R; Powell, G. Louis; Campbell, Peggy J

    2014-03-25

    A method of producing high purity lithium metal is provided, where gaseous-phase lithium metal is extracted from lithium hydride and condensed to form solid high purity lithium metal. The high purity lithium metal may be hydrided to provide high purity lithium hydride.

  4. Investigation of metal hydride nanoparticles templated in metal organic frameworks.

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Benjamin W.; Herberg, Julie L. (Lawrence Livermore National Laboratory, Livermore, CA); Highley, Aaron M.; Grossman, Jeffrey (MIT, Cambridge, MA); Wagner, Lucas (MIT, Cambridge, MA); Bhakta, Raghu; Peaslee, D. (University of Missouri, St. Louis, MO); Allendorf, Mark D.; Liu, X. (University of Missouri, St. Louis, MO); Behrens, Richard, Jr.; Majzoub, Eric H. (University of Missouri, St. Louis, MO)

    2010-11-01

    the hydrogen desorption is investigated using a simultaneous thermogravimetric modulated-beam mass spectrometry instrument. The hydrogen desorption behavior of NaAlH4 nano-clusters is found to be very different from bulk NaAlH4. The bulk NaAlH4 desorbs about 70 wt% hydrogen {approx}250 C. In contrast, confinement of NaAlH4 within the MOF pores dramatically increases the rate of H2 desorption at lower temperatures. About {approx}80% of the total H2 desorbed from MOF-confined NaAlH4 is observed between 70 to 155 C. In addition to HKUST-1, we find that other MOFs (e.g. MIL-68 and MOF-5) can be infiltrated with hydrides (LiAlH4, LiBH4) or hydride precursors (Mg(C4H9)2 and LiC2H5) without degradation. By varying pore dimensions, metal centers, and the linkers of MOFs, it will be possible to determine whether the destabilization of metal hydrides is dictated only by the size of the metal hydride clusters, their local environment in a confined space, or by catalytic effects of the framework.

  5. A method for inversion of layered shear wavespeed azimuthal anisotropy from Rayleigh wave dispersion using the Neighborhood Algorithm

    Institute of Scientific and Technical Information of China (English)

    Huajian Yao

    2015-01-01

    Seismic anisotropy provides important constraints on deformation patterns of Earth's material.Rayleigh wave dispersion data with azimuthal anisotropy can be used to invert for depth-dependent shear wavespeed azimuthal anisotropy,therefore reflecting depth-varying deformation patterns in the crust and upper mantle.In this study,we propose a two-step method that uses the Neighborhood Algorithm (NA) for the point-wise inversion of depth-dependent shear wavespeeds and azimuthal anisotropy from Rayleigh wave azimuthally anisotropic dispersion data.The first step employs the NA to estimate depthdependent Vsv (or the elastic parameter L) as well as their uncertainties from the isotropic part Rayleigh wave dispersion data.In the second step,we first adopt a difference scheme to compute approximate Rayleigh-wave phase velocity sensitivity kernels to azimuthally anisotropic parameters with respect to the velocity model obtained in the first step.Then we perform the NA to estimate the azi.muthally anisotropic parameters Gc/L and Gs/L at depths separately from the corresponding cosine and sine terms of the azimuthally anisotropic dispersion data.Finally,we compute the depth-dependent magnitude and fast polarization azimuth of shear wavespeed azimuthal anisotropy.The use of the global search NA and Bayesian analysis allows for more reliable estimates of depth-dependent shear wavespeeds and azimuthal anisotropy as well as their uncertainties.We illustrate the inversion method using the azimuthally anisotropic dispersion data in SE Tibet,where we find apparent changes of fast axes of shear wavespeed azimuthal anisotropy between the crust and uppermost mantle.

  6. Anodematerials for Metal Hydride Batteries

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf

    1997-01-01

    This report describes the work on development of hydride forming alloys for use as electrode materials in metal hydride batteries. The work has primarily been concentrated on calcium based alloys derived from the compound CaNi5. This compound has a higher capacity compared with alloys used in today......’s hydride batteries, but a much poorer stability towards repeated charge/discharge cycling. The aim was to see if the cycleability of CaNi5 could be enhanced enough by modifications to make the compound a suitable electrode material. An alloying method based on mechanical alloying in a planetary ball mill...... by annealing at 700°C for 12 hours. The alloys appeared to be nanocrystalline with an average crystallite size around 10 nm before annealing. Special steel containers was developed for the annealing of the metal powders in inert atmosphere. The use of various annealing temperatures was investigated...

  7. Hydrogen Storage in Metal Hydrides

    Science.gov (United States)

    1990-08-01

    Hydrogen Storage Capacity Hydride by weight (%) [1) by volume (g/ml) [2] MgH2 7.00 0.101 Mg2NiH4 3.84 0,081 Mg2CuH4 2.04 - - 27 ...Include Security Classification) Hydrogen Storage in Metal Hydrides (U) 12. PERSONAL AUTHOR(S) DelaRosa, Mark J. 13a. TYPE OF REPORT 13b. TIME...objective of this program was to develop an economical process for pr-ducing a lightweight hydrogen storage medium by the chemical vapor infiltration

  8. Crystallography of shear transformations in zirconium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Cassidy, Michael Philip [Univ. of Illinois, Urbana-Champaign, IL (United States)

    1978-01-01

    The crystallography and substructure of the transformations which have been hypothesized as involving a martensitic shear, and which occur between zirconium hydrides were investigated. Specifically, the formation of gamma zirconium hydride from delta hydride and the delta hydride to epsilon hydride transformation were studied. The habit planes, orientation relationships, lattice invariant shears, and interface structures were determined by transmission electron microscopy and diffraction. Surface tilts were observed and measured with an interference microscope. The direction and magnitude of the shape strain produced by the formation of gamma were determined by the measurement of fiducial scratch displacements. These results were compared with the phenomenological crystallographic theory of martensitic transformations.

  9. Characteristics and Applications of Metal Hydrides

    Science.gov (United States)

    Egan, G. J.; Lynch, F. E.

    1987-01-01

    Report discusses engineering principles of uses of metal hydrides in spacecraft. Metal hydrides absorb, store, pump, compress, and expand hydrogen gas. Additionally, they release or absorb sizeable amounts of heat as they form and decompose - property adapted for thermal-energy management or for propulsion. Describes efforts to: Identify heat sources and sinks suitable for driving metal hydride thermal cycles in spacecraft; develop concepts for hydride subsystems employing available heating and cooling methods; and produce data base on estimated sizes, masses, and performances of hydride devices for spacecraft.

  10. Characterization of hydrides and delayed hydride cracking in zirconium alloys

    Science.gov (United States)

    Fang, Qiang

    This thesis tries to fill some of the missing gaps in the study of zirconium hydrides with state-of-art experiments, cutting edge tomographical technique, and a novel numerical algorithm. A new hydriding procedure is proposed. The new anode material and solution combination overcomes many drawbacks of the AECLRTM hydriding method and leads to superior hydriding result compared to the AECL RTM hydriding procedure. The DHC crack growth velocity of as-received Excel alloy and Zr-2.5Nb alloy together with several different heat treated Excel alloy samples are measured. While it already known that the DHC crack growth velocity increases with the increase of base metal strength, the finding that the transverse plane is the weaker plane for fatigue crack growth despite having higher resistance to DHC crack growth was unexpected. The morphologies of hydrides in a coarse grained Zircally-2 sample have been studied using synchrotron x-rays at ESRF with a new technique called Diffraction Contrast Tomography that uses simultaneous collection of tomographic data and diffraction data to determine the crystallographic orientation of crystallites (grains) in 3D. It has been previously limited to light metals such as Al or Mg (due to the use of low energy x-rays). Here we show the first DCT measurements using high energy x-rays (60 keV), allowing measurements in zirconium. A new algorithm of a computationally effcient way to characterize distributions of hydrides - in particular their orientation and/or connectivity - has been proposed. It is a modification of the standard Hough transform, which is an extension of the Hough transform widely used in the line detection of EBSD patterns. Finally, a basic model of hydrogen migration is built using ABAQUS RTM, which is a mature finite element package with tested modeling modules of a variety of physical laws. The coupling of hydrogen diffusion, lattice expansion, matrix deformation and phase transformation is investigated under

  11. Azimuthal Spoke Propagation in Hall Effect Thrusters

    Science.gov (United States)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Spokes are azimuthally propagating perturbations in the plasma discharge of Hall Effect Thrusters (HETs) that travel in the E x B direction and have been observed in many different systems. The propagation of azimuthal spokes are investigated in a 6 kW HET known as the H6 using ultra-fast imaging and azimuthally spaced probes. A spoke surface is a 2-D plot of azimuthal light intensity evolution over time calculated from 87,500 frames/s videos. The spoke velocity has been determined using three methods with similar results: manual fitting of diagonal lines on the spoke surface, linear cross-correlation between azimuthal locations and an approximated dispersion relation. The spoke velocity for three discharge voltages (300, 400 and 450 V) and three anode mass flow rates (14.7, 19.5 and 25.2 mg/s) yielded spoke velocities between 1500 and 2200 m/s across a range of normalized magnetic field settings. The spoke velocity was inversely dependent on magnetic field strength for low B-field settings and asymptoted at B-field higher values. The velocities and frequencies are compared to standard drifts and plasma waves such as E x B drift, electrostatic ion cyclotron, magnetosonic and various drift waves. The empirically approximated dispersion relation yielded a characteristic velocity that matched the ion acoustic speed for 5 eV electrons that exist in the near-anode and near-field plume regions of the discharge channel based on internal measurements. Thruster performance has been linked to operating mode where thrust-to-power is maximized when azimuthal spokes are present so investigating the underlying mechanism of spokes will benefit thruster operation.

  12. Adsorbate Azimuthal Orientation from Reflectance Anisotropy Spectroscopy

    Science.gov (United States)

    Frederick, B. G.; Power, J. R.; Cole, R. J.; Perry, C. C.; Chen, Q.; Haq, S.; Bertrams, Th.; Richardson, N. V.; Weightman, P.

    1998-05-01

    We have determined the azimuthal orientation of an adsorbate on a metal surface from an intramolecular-transition-derived feature in reflectance anisotropy spectroscopy (RAS). Adsorption of 9-anthracene carboxylic acid onto p\\(2×1\\)O/Cu110 led to an ordered structure with a strong (2%), derivativelike feature at 4.5 eV. Fresnel theory predicts the measured intensity, functional behavior, and sense of the RAS signal for the molecule aligned along [110]. IR measurements confirm that the molecular plane is perpendicular to the surface and STM measurements support the azimuthal orientation. We reassign the sense of the clean Cu(110) surface RA spectrum.

  13. Properties of nanoscale metal hydrides.

    Science.gov (United States)

    Fichtner, Maximilian

    2009-05-20

    Nanoscale hydride particles may exhibit chemical stabilities which differ from those of a macroscopic system. The stabilities are mainly influenced by a surface energy term which contains size-dependent values of the surface tension, the molar volume and an additional term which takes into account a potential reduction of the excess surface energy. Thus, the equilibrium of a nanoparticular hydride system may be shifted to the hydrogenated or to the dehydrogenated side, depending on the size and on the prefix of the surface energy term of the hydrogenated and dehydrogenated material. Additional complexity appears when solid-state reactions of complex hydrides are considered and phase segregation has to be taken into account. In such a case the reversibility of complex hydrides may be reduced if the nanoparticles are free standing on a surface. However, it may be enhanced if the system is enclosed by a nanoscale void which prevents the reaction partners on the dehydrogenated side from diffusing away from each other. Moreover, the generally enhanced diffusivity in nanocrystalline systems may lower the kinetic barriers for the material's transformation and, thus, facilitate hydrogen absorption and desorption.

  14. Model-based Corrections to Observed Azimuth and Slowness Deviations from a Dipping Mohorovicic Discontinuity

    Science.gov (United States)

    Flanagan, M. P.; Myers, S.; Simmons, N. A.

    2012-12-01

    Back azimuth and slowness anomalies observed at seismic arrays can be used to constrain local and distant structural and propagation effects in the Earth. Observations of large systematic deviations in both azimuth and slowness measured for several P phases (i.e., Pg, Pn, P, PKP) recorded at several IMS arrays show a characteristic sinusoidal pattern when plotted as a function of theoretical back azimuth. These deviations are often interpreted as the affect of the wavefield being systematically bent by refraction from a dipping velocity structure beneath the array, most likely a dipping Moho. We develop a model-based technique that simultaneously fits back azimuth and slowness observations with a ray-based prediction that incorporates a dipping layer defined by its strike and dip. Because the azimuth and slowness deviations both vary as a function of true azimuth, fitting both residuals jointly will give a more consistent calibration for the array. The technique is used to fit over 9900 observations at CMAR from a global distribution of well-located seismic events. Under the assumption that the dipping layer is the Moho with mantle velocity 8.04 km/sec and crustal velocity 6.2 km/sec, we estimate that Moho strike and dip under the CMAR array are 192.6° and 18.3°, respectively. When the trend of the Moho is removed from the back azimuth and slowness residuals, both the sinuous trend and variations with predicted slowness are mitigated. While a dipping interface model does not account for all of the discrepancy between observed and predicted back azimuth and slowness anomalies, and additional calibration whether empirical or model based should be pursued, this technique is a good first step in the calibration procedure for arrays exhibiting sinusoidal residual trends.

  15. Solvent influence on the thermodynamics for hydride transfer from bis(diphosphine) complexes of nickel.

    Science.gov (United States)

    Connelly Robinson, Samantha J; Zall, Christopher M; Miller, Deanna L; Linehan, John C; Appel, Aaron M

    2016-06-14

    The thermodynamic hydricity of a metal hydride can vary considerably between solvents. This parameter can be used to determine the favourability of a hydride-transfer reaction, such as the reaction between a metal hydride and CO2 to produce formate. Because the hydricities of these species do not vary consistently between solvents, reactions that are thermodynamically unfavourable in one solvent can be favourable in others. The hydricity of a water-soluble, bis-phosphine nickel hydride complex was compared to the hydricity of formate in water and in acetonitrile. Formate is a better hydride donor than [HNi(dmpe)2](+) by 7 kcal mol(-1) in acetonitrile, and no hydride transfer from [HNi(dmpe)2](+) to CO2 occurs in this solvent. The hydricity of [HNi(dmpe)2](+) is greatly improved in water relative to acetonitrile, in that reduction of CO2 to formate by [HNi(dmpe)2](+) was found to be thermodynamically downhill by 8 kcal mol(-1). Catalysis for the hydrogenation of CO2 was pursued, but the regeneration of [HNi(dmpe)2] under catalytic conditions was unfavourable. However, the present results demonstrate that the solvent dependence of thermodynamic parameters such as hydricity and acidity can be exploited in order to produce systems with balanced or favourable overall thermodynamics. This approach should be advantageous for the design of future water-soluble catalysts.

  16. Azimuthal anisotropy of jet quenching at LHC

    Indian Academy of Sciences (India)

    I P Lokhtin; S V Petrushanko; L I Sarycheva; A M Snigirev

    2003-05-01

    We analyze the azimuthal anisotropy of jet spectra due to energy loss of hard partons in quark–gluon plasma, created initially in nuclear overlap zone in collisions with non-zero impact parameter. The calculations are performed for semi-central Pb–Pb collisions at LHC energy.

  17. The renaissance of hydrides as energy materials

    Science.gov (United States)

    Mohtadi, Rana; Orimo, Shin-Ichi

    2017-02-01

    Materials based on hydrides have been the linchpin in the development of several practical energy storage technologies, of which the most prominent example is nickel-metal hydride batteries. Motivated by the need to meet the future's energy demand, the past decade has witnessed substantial advancements in the research and development of hydrides as media for hydrogen energy storage. More recently, new and rapidly evolving discoveries have positioned hydrides as highly promising materials for future electrochemical energy storage, such as electrolytes for mono- and divalent batteries, and anodes for lithium-ion batteries. In addition, the potential of hydrides in efficient power transmission has been recently revealed. In this Review, we highlight key advances and illustrate how the versatility of hydrides has not only yielded a meaningful past, but also ensures a very bright future.

  18. Rechargeable metal hydrides for spacecraft application

    Science.gov (United States)

    Perry, J. L.

    1988-01-01

    Storing hydrogen on board the Space Station presents both safety and logistics problems. Conventional storage using pressurized bottles requires large masses, pressures, and volumes to handle the hydrogen to be used in experiments in the U.S. Laboratory Module and residual hydrogen generated by the ECLSS. Rechargeable metal hydrides may be competitive with conventional storage techniques. The basic theory of hydride behavior is presented and the engineering properties of LaNi5 are discussed to gain a clear understanding of the potential of metal hydrides for handling spacecraft hydrogen resources. Applications to Space Station and the safety of metal hydrides are presented and compared to conventional hydride storage. This comparison indicates that metal hydrides may be safer and require lower pressures, less volume, and less mass to store an equivalent mass of hydrogen.

  19. Nanostructured, complex hydride systems for hydrogen generation

    Directory of Open Access Journals (Sweden)

    Robert A. Varin

    2015-02-01

    Full Text Available Complex hydride systems for hydrogen (H2 generation for supplying fuel cells are being reviewed. In the first group, the hydride systems that are capable of generating H2 through a mechanical dehydrogenation phenomenon at the ambient temperature are discussed. There are few quite diverse systems in this group such as lithium alanate (LiAlH4 with the following additives: nanoiron (n-Fe, lithium amide (LiNH2 (a hydride/hydride system and manganese chloride MnCl2 (a hydride/halide system. Another hydride/hydride system consists of lithium amide (LiNH2 and magnesium hydride (MgH2, and finally, there is a LiBH4-FeCl2 (hydride/halide system. These hydride systems are capable of releasing from ~4 to 7 wt.% H2 at the ambient temperature during a reasonably short duration of ball milling. The second group encompasses systems that generate H2 at slightly elevated temperature (up to 100 °C. In this group lithium alanate (LiAlH4 ball milled with the nano-Fe and nano-TiN/TiC/ZrC additives is a prominent system that can relatively quickly generate up to 7 wt.% H2 at 100 °C. The other hydride is manganese borohydride (Mn(BH42 obtained by mechano-chemical activation synthesis (MCAS. In a ball milled (2LiBH4 + MnCl2 nanocomposite, Mn(BH42 co-existing with LiCl can desorb ~4.5 wt.% H2 at 100 °C within a reasonable duration of dehydrogenation. Practical application aspects of hydride systems for H2 generation/storage are also briefly discussed.

  20. Use of reversible hydrides for hydrogen storage

    Science.gov (United States)

    Darriet, B.; Pezat, M.; Hagenmuller, P.

    1980-01-01

    The addition of metals or alloys whose hydrides have a high dissociation pressure allows a considerable increase in the hydrogenation rate of magnesium. The influence of temperature and hydrogen pressure on the reaction rate were studied. Results concerning the hydriding of magnesium rich alloys such as Mg2Ca, La2Mg17 and CeMg12 are presented. The hydriding mechanism of La2Mg17 and CeMg12 alloys is given.

  1. Inhibited solid propellant composition containing beryllium hydride

    Science.gov (United States)

    Thompson, W. W. (Inventor)

    1978-01-01

    An object of this invention is to provide a composition of beryllium hydride and carboxy-terminated polybutadiene which is stable. Another object of this invention is to provide a method for inhibiting the reactivity of beryllium hydride toward carboxy-terminated polybutadiene. It was found that a small amount of lecithin inhibits the reaction of beryllium hydride with the acid groups in carboxy terminated polybutadiene.

  2. Anodematerials for Metal Hydride Batteries

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf

    1997-01-01

    by annealing at 700°C for 12 hours. The alloys appeared to be nanocrystalline with an average crystallite size around 10 nm before annealing. Special steel containers was developed for the annealing of the metal powders in inert atmosphere. The use of various annealing temperatures was investigated......This report describes the work on development of hydride forming alloys for use as electrode materials in metal hydride batteries. The work has primarily been concentrated on calcium based alloys derived from the compound CaNi5. This compound has a higher capacity compared with alloys used in today...... was developed. The parameters milling time, milling intensity, number of balls and form of the alloying metals were investigated. Based on this a final alloying technique for the subsequent preparation of electrode materials was established. The technique comprises milling for 4 hours twice possibly followed...

  3. Predicting formation enthalpies of metal hydrides

    DEFF Research Database (Denmark)

    Andreasen, A.

    2004-01-01

    In order for the hydrogen based society viz. a society in which hydrogen is the primary energy carrier to become realizable an efficient way of storing hydrogen is required. For this purpose metal hydrides are serious candidates. Metal hydrides are formedby chemical reaction between hydrogen...... and metal and for the stable hydrides this is associated with release of heat (#DELTA#H_f ). The more thermodynamically stable the hydride, the larger DHf, and the higher temperature is needed in order to desorphydrogen (reverse reaction) and vice versa. For practical application the temperature needed...

  4. Research on Metal Hydride Compressor System

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Ti-Zr series Laves phase hydrogen storage alloys with good hydrogen storage properties, such as large hydrogen capacity, rapid hydriding and dehydriding rate, high compression ratio, gentle plateau, small hysteresis, easily being activated and long cyclic stability etc. for metal hydride compressor have been investigated. In addition, a hydride compressor with special characteristics, namely, advanced filling method, good heat transfer effect and reasonable structural design etc. has also been constructed. A hydride compressor cryogenic system has been assembled coupling the compressor with a J-T micro-throttling refrigeration device and its cooling capacity can reach 0.4 W at 25 K.

  5. Thermodynamic Hydricity of Transition Metal Hydrides.

    Science.gov (United States)

    Wiedner, Eric S; Chambers, Matthew B; Pitman, Catherine L; Bullock, R Morris; Miller, Alexander J M; Appel, Aaron M

    2016-08-10

    Transition metal hydrides play a critical role in stoichiometric and catalytic transformations. Knowledge of free energies for cleaving metal hydride bonds enables the prediction of chemical reactivity, such as for the bond-forming and bond-breaking events that occur in a catalytic reaction. Thermodynamic hydricity is the free energy required to cleave an M-H bond to generate a hydride ion (H(-)). Three primary methods have been developed for hydricity determination: the hydride transfer method establishes hydride transfer equilibrium with a hydride donor/acceptor pair of known hydricity, the H2 heterolysis method involves measuring the equilibrium of heterolytic cleavage of H2 in the presence of a base, and the potential-pKa method considers stepwise transfer of a proton and two electrons to give a net hydride transfer. Using these methods, over 100 thermodynamic hydricity values for transition metal hydrides have been determined in acetonitrile or water. In acetonitrile, the hydricity of metal hydrides spans a range of more than 50 kcal/mol. Methods for using hydricity values to predict chemical reactivity are also discussed, including organic transformations, the reduction of CO2, and the production and oxidation of hydrogen.

  6. Coinage Metal Hydrides: Synthesis, Characterization, and Reactivity.

    Science.gov (United States)

    Jordan, Abraham J; Lalic, Gojko; Sadighi, Joseph P

    2016-08-10

    Hydride complexes of copper, silver, and gold encompass a broad array of structures, and their distinctive reactivity has enabled dramatic recent advances in synthesis and catalysis. This Review summarizes the synthesis, characterization, and key stoichiometric reactions of isolable or observable coinage metal hydrides. It discusses catalytic processes in which coinage metal hydrides are known or probable intermediates, and presents mechanistic studies of selected catalytic reactions. The purpose of this Review is to convey how developments in coinage metal hydride chemistry have led to new organic transformations, and how developments in catalysis have in turn inspired the synthesis of reactive new complexes.

  7. Reversible metal-hydride phase transformation in epitaxial films.

    Science.gov (United States)

    Roytburd, Alexander L; Boyerinas, Brad M; Bruck, Hugh A

    2015-03-11

    Metal-hydride phase transformations in solids commonly proceed with hysteresis. The extrinsic component of hysteresis is the result of the dissipation of energy of internal stress due to plastic deformation and fracture. It can be mitigated on the nanoscale, where plastic deformation and fracture are suppressed and the transformation proceeds through formation and evolution of coherent phases. However, the phase coherency introduces intrinsic thermodynamic hysteresis, preventing reversible transformation. In this paper, it is shown that thermodynamic hysteresis of coherent metal-hydride transformation can be eliminated in epitaxial film due to substrate constraint. Film-substrate interaction leads to formation of heterophase polydomain nanostructure with variable phase fraction which can change reversibly by varying temperature in a closed system or chemical potential in an open system.

  8. Crystal structure of gold hydride

    Energy Technology Data Exchange (ETDEWEB)

    Degtyareva, Valentina F., E-mail: degtyar@issp.ac.ru

    2015-10-05

    Highlights: • Volume expansion of metal hydrides is due to the increase in the s-band filling. • AuH structure is similar to that of Hg having one more s electron compared to Au. • Structure stability of both Hg and AuH is governed by the Hume-Rothery rule. - Abstract: A number of transition metal hydrides with close-packed metal sublattices of fcc or hcp structures with hydrogen in octahedral interstitial positions were obtained by the high-pressure-hydrogen technique described by Ponyatovskii et al. (1982). In this paper we consider volume increase of metals by hydrogenation and possible crystal structure of gold hydride in relation with the structure of mercury, the nearest neighbor of Au in the Periodic table. Suggested structure of AuH has a basic tetragonal body-centered cell that is very similar to the mercury structure Hg-t I 2. The reasons of stability for this structure are discussed within the model of Fermi sphere–Brillouin zone interactions.

  9. Azimuthal Doppler Effect in Optical Vortex Spectroscopy

    Science.gov (United States)

    Aramaki, Mitsutoshi; Yoshimura, Shinji; Toda, Yasunori; Morisaki, Tomohiro; Terasaka, Kenichiro; Tanaka, Masayoshi

    2015-11-01

    Optical vortices (OV) are a set of solutions of the paraxial Helmholtz equation in the cylindrical coordinates, and its wave front has a spiral shape. Since the Doppler shift is caused by the phase change by the movement in a wave field, the observer in the OV, which has the three-dimensional structured wave front, feels a three-dimensional Doppler effect. Since the multi-dimensional Doppler components are mixed into a single Doppler spectrum, development of a decomposition method is required. We performed a modified saturated absorption spectroscopy to separate the components. The OV and plane wave are used as a probe beam and pump beam, respectively. Although the plane-wave pump laser cancels the z-direction Doppler shift, the azimuthal Doppler shift remains in the saturated dip. The spatial variation of the dip width gives the information of the azimuthal Doppler shift. The some results of optical vortex spectroscopy will be presented.

  10. On the azimuthal asymmetries in DIS

    CERN Document Server

    Efremov, E V; Göke, K; Urbano, D

    2000-01-01

    Using the recent experimental data on the left right asymmetry in fragmentation of transversely polarized quarks and the theoretical calculation of the proton transversity distribution in the effective chiral quark soliton model we explain the azimuthal asymmetries in semi-inclusive hadron production on longitudinal (HERMES) and transversely (SMC) polarized targets with no free parameters. On this basis we state that the proton transversity distribution could be successfully measured in future DIS experiments with longitudinally polarized target.

  11. Azimuthal correlations in photon-photon collisions

    CERN Document Server

    Artéaga-Romero, N; Kessler, P; Ong, S; Panella, O

    1995-01-01

    Using the general helicity formula for \\gamma^* \\gamma^* collisions, we are showing that it should be possible to determine a number of independent ``structure functions'', i.e. linear combinations of elements of the two-photon helicity tensor, through azimuthal correlations in two-body or quasi two-body reactions induced by the photon-photon interaction, provided certain experimental conditions are satisfied. Numerical results of our computations are presented for some particular processes and dynamic models.

  12. Azimuthal effects in grazing surface scattering

    Energy Technology Data Exchange (ETDEWEB)

    Robin, A. E-mail: arobin@uos.de; Jensen, J.; Heiland, W

    2003-06-01

    We report on surface scattering experiments in the MeV regime. N{sup q+} (q=1, 2) ions with 0.7-1.4 MeV are scattered off a single-crystalline Pt(110)(1x2) surface under grazing incidence and specular reflection geometry. We investigate the energy loss dependency on the azimuthal angle under variation of the perpendicular energy.

  13. Metal Hydrides for Rechargeable Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Valoeen, Lars Ole

    2000-03-01

    Rechargeable battery systems are paramount in the power supply of modern electronic and electromechanical equipment. For the time being, the most promising secondary battery systems for the future are the lithium-ion and the nickel metal hydride (NiMH) batteries. In this thesis, metal hydrides and their properties are described with the aim of characterizing and improving those. The thesis has a special focus on the AB{sub 5} type hydrogen storage alloys, where A is a rare earth metal like lanthanum, or more commonly misch metal, which is a mixture of rare earth metals, mainly lanthanum, cerium, neodymium and praseodymium. B is a transition metal, mainly nickel, commonly with additions of aluminium, cobalt, and manganese. The misch metal composition was found to be very important for the geometry of the unit cell in AB{sub 5} type alloys, and consequently the equilibrium pressure of hydrogen in these types of alloys. The A site substitution of lanthanum by misch metal did not decrease the surface catalytic properties of AB{sub 5} type alloys. B-site substitution of nickel with other transition elements, however, substantially reduced the catalytic activity of the alloy. If the internal pressure within the electrochemical test cell was increased using inert argon gas, a considerable increase in the high rate charge/discharge performance of LaNi{sub 5} was observed. An increased internal pressure would enable the utilisation of alloys with a high hydrogen equivalent pressure in batteries. Such alloys often have favourable kinetics and high hydrogen diffusion rates and thus have a potential for improving the high current discharge rates in metal hydride batteries. The kinetic properties of metal hydride electrodes were found to improve throughout their lifetime. The activation properties were found highly dependent on the charge/discharge current. Fewer charge/discharge cycles were needed to activate the electrodes if a small current was used instead of a higher

  14. Metal Hydrides for Rechargeable Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Valoeen, Lars Ole

    2000-03-01

    Rechargeable battery systems are paramount in the power supply of modern electronic and electromechanical equipment. For the time being, the most promising secondary battery systems for the future are the lithium-ion and the nickel metal hydride (NiMH) batteries. In this thesis, metal hydrides and their properties are described with the aim of characterizing and improving those. The thesis has a special focus on the AB{sub 5} type hydrogen storage alloys, where A is a rare earth metal like lanthanum, or more commonly misch metal, which is a mixture of rare earth metals, mainly lanthanum, cerium, neodymium and praseodymium. B is a transition metal, mainly nickel, commonly with additions of aluminium, cobalt, and manganese. The misch metal composition was found to be very important for the geometry of the unit cell in AB{sub 5} type alloys, and consequently the equilibrium pressure of hydrogen in these types of alloys. The A site substitution of lanthanum by misch metal did not decrease the surface catalytic properties of AB{sub 5} type alloys. B-site substitution of nickel with other transition elements, however, substantially reduced the catalytic activity of the alloy. If the internal pressure within the electrochemical test cell was increased using inert argon gas, a considerable increase in the high rate charge/discharge performance of LaNi{sub 5} was observed. An increased internal pressure would enable the utilisation of alloys with a high hydrogen equivalent pressure in batteries. Such alloys often have favourable kinetics and high hydrogen diffusion rates and thus have a potential for improving the high current discharge rates in metal hydride batteries. The kinetic properties of metal hydride electrodes were found to improve throughout their lifetime. The activation properties were found highly dependent on the charge/discharge current. Fewer charge/discharge cycles were needed to activate the electrodes if a small current was used instead of a higher

  15. Kinetics of hydride front in Zircaloy-2 and H release from a fractional hydrided surface

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, M.; Gonzalez-Gonzalez, A.; Moya, J. S.; Remartinez, B.; Perez, S.; Sacedon, J. L. [Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Iberdrola, Tomas Redondo 3, 28033 Madrid (Spain); Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain)

    2009-07-15

    The authors study the hydriding process on commercial nuclear fuel claddings from their inner surface using an ultrahigh vacuum method. The method allows determining the incubation and failure times of the fuel claddings, as well as the dissipated energy and the partial pressure of the desorbed H{sub 2} from the outer surface of fuel claddings during the hydriding process. The correlation between the hydriding dissipated energy and the amount of zirconium hydride (formed at different stages of the hydriding process) leads to a near t{sup 1/2} potential law corresponding to the time scaling of the reaction for the majority of the tested samples. The calibrated relation between energy and hydride thickness allows one to calculate the enthalpy of the {delta}-ZrH{sub 1.5} phase. The measured H{sub 2} desorption from the external surface is in agreement with a proposed kinetic desorption model from the hydrides precipitated at the surface.

  16. Azimuthally dependent radiative transfer in a non-homogeneous cylindrical medium

    CERN Document Server

    Hsu, S C; Ou, N R

    1998-01-01

    This work applies the discrete-ordinate method (DOM) to study azimuthally dependent radiative transfer in a two-dimensional cylindrical medium with spatially varying properties. Product angular quadratures are selected to generate discrete-ordinate approximations. The validity of the present DOM scheme is examined by comparing the present results with the results available in the literature. The effects of the optical thickness and the spatially varying extinction coefficient, scattering albedo and coefficients of the phase function are investigated.

  17. Ionic conduction of lithium hydride single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Pilipenko, G.I.; Oparin, D.V.; Zhuravlev, N.A.; Gavrilov, F.F.

    1987-09-01

    Using the electrical-conductivity- and NMR-measurement- methods, the ionic-conduction mechanism is established in stoichiometric lithium hydride single crystals. The activation energies of migration of anion- and cation-vacancies and the formation of Schottky-pair defects are determined. They assume that the mechanisms of self-diffusion and conductivity are different in lithium hydride.

  18. Rescuing the nonjet (NJ) azimuth quadrupole from the flow narrative

    CERN Document Server

    Trainor, Thomas A

    2016-01-01

    According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity $v_2$ and interpreted to represent elliptic flow. Jet angular correlations may also contribute to $v_2$ data as "nonflow" depending on the method used to calculate $v_2$, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ) quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modification ("jet quenching") in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential $v_2(p_t)$ data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quad...

  19. Investigation of long term stability in metal hydrides

    Science.gov (United States)

    Marmaro, Roger W.; Lynch, Franklin E.; Chandra, Dhanesh; Lambert, Steve; Sharma, Archana

    1991-01-01

    It is apparent from the literature and the results of this study that cyclic degradation of AB(5) type metal hydrides varies widely according to the details of how the specimens are cycled. The Rapid Cycle Apparatus (RCA) used produced less degradation in 5000 to 10000 cycles than earlier work with a Slow Cycle Apparatus (SCA) produced in 1500 cycles. Evidence is presented that the 453 K (356 F) Thermal Aging (TA) time spent in the saturated condition causes hydride degradation. But increasing the cooling (saturation) period in the RCA did not greatly increase the rate of degradation. It appears that TA type degradation is secondary at low temperatures to another degradation mechanism. If rapid cycles are less damaging than slow cycles when the saturation time is equal, the rate of hydriding/dehydriding may be an important factor. The peak temperatures in the RCA were about 30 C lower than the SCA. The difference in peak cycle temperatures (125 C in the SCA, 95 C in RCA) cannot explain the differences in degradation. TA type degradation is similar to cyclic degradation in that nickel peaks and line broadening are observed in X ray diffraction patterns after either form of degradation.

  20. Submillimeter Spectroscopy of Hydride Molecules

    Science.gov (United States)

    Phillips, T. G.

    1998-05-01

    Simple hydride molecules are of great importance in astrophysics and astrochemistry. Physically they dominate the cooling of dense, warm phases of the ISM, such as the cores and disks of YSOs. Chemically they are often stable end points of chemical reactions, or may represent important intermediate stages of the reaction chains, which can be used to test the validity of the process. Through the efforts of astronomers, physicists, chemists, and laboratory spectroscopists we have an approximate knowledge of the abundance of some of the important species, but a great deal of new effort will be required to achieve the comprehensive and accurate data set needed to determine the energy balance and firmly establish the chemical pathways. Due to the low moment of inertia, the hydrides rotate rapidly and so have their fundamental spectral lines in the submillimeter. Depending on the cloud geometry and temperature profile they may be observed in emission or absorption. Species such as HCl, HF, OH, CH, CH(+) , NH_2, NH_3, H_2O, H_2S, H_3O(+) and even H_3(+) have been detected, but this is just a fraction of the available set. Also, most deduced abundances are not nearly sufficiently well known to draw definitive conclusions about the chemical processes. For example, the most important coolant for many regions, H_2O, has a possible range of deduced abundance of a factor of 1000. The very low submillimeter opacity at the South Pole site will be a significant factor in providing a new capabilty for interstellar hydride spectroscopy. The new species and lines made available in this way will be discussed.

  1. Azimuthal Spoke Propagation in Hall Effect Thrusters

    Science.gov (United States)

    2013-10-01

    to bk. The cross-correlation function is17 Rjk = lim T→∞ 1 T ∫ T 0 bj (t) bk (t + τ)dt (2) Signal delays for non -frequency dispersive propagation can...During the neutral replenishment period within the discharge channel, slight perturbations or azimuthal non - uniformities in electron density, electron...electron thermal velocity is the average of an assumed Maxwellian distribution37 vthe = √ 8qTe/(πme) with Te in eV. The region from 0.16 < z/Lchnl

  2. Azimuth orientation of the dragonfly (Sympetrum)

    Science.gov (United States)

    Hisada, M.

    1972-01-01

    Evidence is presented of directional orientation by an alighting dragonfly relative to the azimuth of the sun. The effects of wind direction on this orientation are analyzed. It was concluded that wind does not play a major role in orientation but may have some secondary function in helping greater numbers of dragonflies face windward more often than leeward. A search was made to find the principle sensory receptor for orientation. Two possibilities, the large compound eye and the frontal ocelli, were noted; however, no conclusive evidence could be found.

  3. Moveout analysis of wide-azimuth data in the presence of lateral velocity variation

    KAUST Repository

    Takanashi, Mamoru

    2012-05-01

    Moveout analysis of wide-azimuth reflection data seldom takes into account lateral velocity variations on the scale of spreadlength. However, velocity lenses (such as channels and reefs) in the overburden can cause significant, laterally varying errors in the moveout parameters and distortions in data interpretation. Here, we present an analytic expression for the normal-moveout (NMO) ellipse in stratified media with lateral velocity variation. The contribution of lateral heterogeneity (LH) is controlled by the second derivatives of the interval vertical traveltime with respect to the horizontal coordinates, along with the depth and thickness of the LH layer. This equation provides a quick estimate of the influence of velocity lenses and can be used to substantially mitigate the lens-induced distortions in the effective and interval NMO ellipses. To account for velocity lenses in nonhyperbolic moveout inversion of wide-azimuth data, we propose a prestack correction algorithm that involves computation of the lens-induced traveltime distortion for each recorded trace. The overburden is assumed to be composed of horizontal layers (one of which contains the lens), but the target interval can be laterally heterogeneous with dipping or curved interfaces. Synthetic tests for horizontally layered models confirm that our algorithm accurately removes lens-related azimuthally varying traveltime shifts and errors in the moveout parameters. The developed methods should increase the robustness of seismic processing of wide-azimuth surveys, especially those acquired for fracture-characterization purposes. © 2012 Society of Exploration Geophysicists.

  4. A DFT based investigation into the electronic structure and properties of hydride rich rhodium clusters.

    Science.gov (United States)

    Brayshaw, Simon K; Green, Jennifer C; Hazari, Nilay; Weller, Andrew S

    2007-05-14

    Density functional theory has been used to investigate the structures, bonding and properties of a family of hydride rich late transition metal clusters of the type [Rh(6)(PH(3))(6)H(12)](x) (x = 0, +1, +2, +3 or +4), [Rh(6)(PH(3))(6)H(16)](x) (x = +1 or +2) and [Rh(6)(PH(3))(6)H(14)](x) (x = 0, +1 or +2). The positions of the hydrogen atoms around the pseudo-octahedral Rh(6) core in the optimized structures of [Rh(6)(PH(3))(6)H(12)](x) (x = 0, +1, +2, +3 or +4) varied depending on the overall charge on the cluster. The number of semi-bridging hydrides increased (semi-bridging hydrides have two different Rh-H bond distances) as the charge on the cluster increased and simultaneously the number of perfectly bridging hydrides (equidistant between two Rh centers) decreased. This distortion maximized the bonding between the hydrides and the metal centers and resulted in the stabilization of orbitals related to the 2T(2g) set in a perfectly octahedral cluster. In contrast, the optimized structures of the 16-hydride clusters [Rh(6)(PH(3))(6)H(12)](x) (x = +1 or +2) were similar and both clusters contained an interstitial hydride, along with one terminal hydride, ten bridging hydrides and two coordinated H(2) molecules which were bound to two rhodium centers in an eta(2):eta(1)-fashion. All the hydrides were on the outside of the Rh(6) core in the lowest energy structures of the 14-hydride clusters [Rh(6)(PH(3))(6)H(14)] and [Rh(6)(PH(3))(6)H(14)](+), which both contained eleven bridging hydrides, one terminal hydride and one coordinated H(2) molecule. Unfortunately, the precise structure of [Rh(6)(PH(3))(6)H(14)](2+) could not be determined as structures both with and without an interstitial hydride were of similar energy. The reaction energetics for the uptake and release of two molecule of H(2) by a cycle consisting of [Rh(6)(PH(3))(6)H(12)](2+), [Rh(6)(PH(3))(6)H(16)](2+), [Rh(6)(PH(3))(6)H(14)](+), [Rh(6)(PH(3))(6)H(12)](+) and [Rh(6)(PH(3))(6)H(14)](2+) were modelled

  5. Hydrogen-storing hydride complexes

    Science.gov (United States)

    Srinivasan, Sesha S [Tampa, FL; Niemann, Michael U [Venice, FL; Goswami, D Yogi [Tampa, FL; Stefanakos, Elias K [Tampa, FL

    2012-04-10

    A ternary hydrogen storage system having a constant stoichiometric molar ratio of LiNH.sub.2:MgH.sub.2:LiBH.sub.4 of 2:1:1. It was found that the incorporation of MgH.sub.2 particles of approximately 10 nm to 20 nm exhibit a lower initial hydrogen release temperature of 150.degree. C. Furthermore, it is observed that the particle size of LiBNH quaternary hydride has a significant effect on the hydrogen sorption concentration with an optimum size of 28 nm. The as-synthesized hydrides exhibit two main hydrogen release temperatures, one around 160.degree. C. and the other around 300.degree. C., with the main hydrogen release temperature reduced from 310.degree. C. to 270.degree. C., while hydrogen is first reversibly released at temperatures as low as 150.degree. C. with a total hydrogen capacity of 6 wt. % to 8 wt. %. Detailed thermal, capacity, structural and microstructural properties have been demonstrated and correlated with the activation energies of these materials.

  6. Azimuthal dynamo wave in spherical shell convection

    CERN Document Server

    Cole, Elizabeth; Mantere, Maarit J; Brandenburg, Axel

    2013-01-01

    We report the finding of an azimuthal dynamo wave of a low-order (m=1) mode in direct numerical simulations (DNS) of turbulent convection in spherical shells. Such waves are predicted by mean field dynamo theory and have been obtained previously in mean-field models. Observational results both from photometry and Doppler imaging have revealed persistent drifts of spots for several rapidly rotating stars, but, although an azimuthal dynamo wave has been proposed as a possible mechanism responsible for this behavior, it has been judged as unlikely, as practical evidence for such waves from DNS has been lacking. The large-scale magnetic field in our DNS, which is due to self-consistent dynamo action, is dominated by a retrograde m=1 mode. Its pattern speed is nearly independent of latitude and does not reflect the speed of the differential rotation at any depth. The extrema of magnetic m=1 structures coincide reasonably with the maxima of m=2 structures of the temperature. These results provide direct support for...

  7. Hydride heat pump with heat regenerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  8. Modeling of Gallium Nitride Hydride Vapor Phase Epitaxy

    Science.gov (United States)

    Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

    1997-01-01

    A reactor model for the hydride vapor phase epitaxy of GaN is presented. The governing flow, energy, and species conservation equations are solved in two dimensions to examine the growth characteristics as a function of process variables and reactor geometry. The growth rate varies with GaCl composition but independent of NH3 and H2 flow rates. A change in carrier gas for Ga source from H2 to N2 affects the growth rate and uniformity for a fixed reactor configuration. The model predictions are in general agreement with observed experimental behavior.

  9. A Novel Azimuth Super-Resolution Method by Synthesizing Azimuth Bandwidth of Multiple Tracks of Airborne Stripmap SAR Data

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2016-06-01

    Full Text Available Azimuth resolution of airborne stripmap synthetic aperture radar (SAR is restricted by the azimuth antenna size. Conventionally, a higher azimuth resolution should be achieved by employing alternate modes that steer the beam in azimuth to enlarge the synthetic antenna aperture. However, if a data set of a certain region, consisting of multiple tracks of airborne stripmap SAR data, is available, the azimuth resolution of specific small region of interest (ROI can be conveniently improved by a novel azimuth super-resolution method as introduced by this paper. The proposed azimuth super-resolution method synthesize the azimuth bandwidth of the data selected from multiple discontinuous tracks and contributes to a magnifier-like function with which the ROI can be further zoomed in with a higher azimuth resolution than that of the original stripmap images. Detailed derivation of the azimuth super-resolution method, including the steps of two-dimensional dechirping, residual video phase (RVP removal, data stitching and data correction, is provided. The restrictions of the proposed method are also discussed. Lastly, the presented approach is evaluated via both the single- and multi-target computer simulations.

  10. A Novel Azimuth Super-Resolution Method by Synthesizing Azimuth Bandwidth of Multiple Tracks of Airborne Stripmap SAR Data.

    Science.gov (United States)

    Wang, Yan; Li, Jingwen; Sun, Bing; Yang, Jian

    2016-06-13

    Azimuth resolution of airborne stripmap synthetic aperture radar (SAR) is restricted by the azimuth antenna size. Conventionally, a higher azimuth resolution should be achieved by employing alternate modes that steer the beam in azimuth to enlarge the synthetic antenna aperture. However, if a data set of a certain region, consisting of multiple tracks of airborne stripmap SAR data, is available, the azimuth resolution of specific small region of interest (ROI) can be conveniently improved by a novel azimuth super-resolution method as introduced by this paper. The proposed azimuth super-resolution method synthesize the azimuth bandwidth of the data selected from multiple discontinuous tracks and contributes to a magnifier-like function with which the ROI can be further zoomed in with a higher azimuth resolution than that of the original stripmap images. Detailed derivation of the azimuth super-resolution method, including the steps of two-dimensional dechirping, residual video phase (RVP) removal, data stitching and data correction, is provided. The restrictions of the proposed method are also discussed. Lastly, the presented approach is evaluated via both the single- and multi-target computer simulations.

  11. Spontaneous azimuthal breakout and instability at the circular hydraulic jump

    CERN Document Server

    Ray, Arnab K; Basu, Abhik; Bhattacharjee, Jayanta K

    2015-01-01

    We consider a shallow, two-dimensional flow of a liquid in which the radial and the azimuthal dynamics are coupled to each other. The steady and radial background flow of this system creates an axially symmetric circular hydraulic jump. On this background we apply time-dependent perturbations of the matter flow rate and the azimuthal flow velocity, with the latter strongly localized at the hydraulic jump. The perturbed variables depend spatially on both the radial and azimuthal coordinates. Linearization of the perturbations gives a coupled system of wave equations. The characteristic equations extracted from these wave equations show that under a marginally stable condition a spontaneous breaking of axial symmetry occurs at the position of the hydraulic jump. Departure from the marginal stability shows further that a linear instability develops in the azimuthal direction, resulting in an azimuthal transport of liquid at the hydraulic jump. The time for the growth of azimuthal instability is scaled by viscosi...

  12. Gyroscopic Inertial Micro-Balance Azimuth Locator (GIMBAL) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Research Support Instruments, Inc. (RSI) proposes the Gyroscopic Inertial Micro-Balance Azimuth Locator (GIMBAL) program to use an innovative encapsulated spinning...

  13. Comparison of the reference mark azimuth determination methods

    Directory of Open Access Journals (Sweden)

    Danijel Šugar

    2013-03-01

    Full Text Available The knowledge of the azimuth of the reference mark is of crucial importance in the determination of the declination which is defined as the ellipsoidal (geodetic azimuth of the geomagnetic meridian. The accuracy of the azimuth determination has direct impact on the accuracy of the declination. The orientation of the Declination-Inclination Magnetometer is usually carried out by sighting the reference mark in two telescope faces in order to improve the reliability of the observations and eliminate some instrumental errors. In this paper, different coordinate as well as azimuth determination methods using GNSS (Global Navigation Satellite System observation techniques within VPPS (High-Precision Positioning Service and GPPS (Geodetic-Precision Positioning Service services of the CROPOS (CROatian POsitioning System system were explained. The azimuth determination by the observation of the Polaris was exposed and it was subsequently compared with the observation of the Sun using hour-angle and zenith-distance method. The procedure of the calculation of the geodetic azimuth from the astronomic azimuth was explained. The azimuth results obtained by different methods were compared and the recommendations on the minimal distance between repeat station and azimuth mark were given. The results shown in this paper were based on the observations taken on the POKU_SV repeat station.

  14. Preparing for measurements of dijet azimuthal decorrelations at ATLAS

    CERN Document Server

    Moraes, A; Clements, D; Skillicorn, I O

    2005-01-01

    Dijet azimuthal decorrelations are investigated in this report. We present a study on how well the event generators PYTHIA, HERWIG and HERWIG+JIMMY describe some of the recent measurements on dijet azimuthal decorrelations made by D0. We predict the correlations in the azimuthal angle between the two largest transverse momentum jets in the central rapidity for LHC inclusive dijet event samples. Reconstructed dijet azimuthal decorrelation distributions for simulated jet events at ATLAS (Rome samples) are shown to reproduce the MC event generator predictions.

  15. Angular MET sensor for precise azimuth determination

    Science.gov (United States)

    Zaitsev, Dmitry; Antonov, Alexander; Krishtop, Vladimir

    2016-12-01

    This paper describes using a MET-based low-noise angular motion sensor to precisely determine azimuth direction in a dynamic-scheme method of measuring Earth's rotation velocity vector. The scheme includes installing a sensor on a rotating platform so that it could scan a space and seek for the position of highest Earth's rotation vector projection on its axis. This method is very efficient provided a low-noise sensor is used. We take a low-cost angular sensor based on MET (molecular electronic transduction) technology. Sensors of this kind were originally developed for the seismic activity monitoring and are well-known for very good noise performance and high sensitivity. This approach, combined with use of special signal processing algorithms, allowed for reaching the accuracy of 0.07° for a measurement time of 200 seconds.

  16. Hydrogen storage in complex metal hydrides

    National Research Council Canada - National Science Library

    Bogdanovic, Borislav; Felderhoff, Michael; Streukens, Guido

    2009-01-01

    ...) are solid-state hydrogen-storage materials with high hydrogen capacities. They can be used in combination with fuel cells as a hydrogen source thus enabling longer operation times compared with classical metal hydrides...

  17. Method of forming metal hydride films

    Science.gov (United States)

    Steinberg, R.; Alger, D. L.; Cooper, D. W. (Inventor)

    1977-01-01

    The substrate to be coated (which may be of metal, glass or the like) is cleaned, both chemically and by off-sputtering in a vacuum chamber. In an ultra-high vacuum system, vapor deposition by a sublimator or vaporizer coats a cooled shroud disposed around the substrate with a thin film of hydride forming metal which getters any contaminant gas molecules. A shutter is then opened to allow hydride forming metal to be deposited as a film or coating on the substrate. After the hydride forming metal coating is formed, deuterium or other hydrogen isotopes are bled into the vacuum system and diffused into the metal film or coating to form a hydride of metal film. Higher substrate temperatures and pressures may be used if various parameters are appropriately adjusted.

  18. Sealed aerospace metal-hydride batteries

    Science.gov (United States)

    Coates, Dwaine

    1992-01-01

    Nickel metal hydride and silver metal hydride batteries are being developed for aerospace applications. There is a growing market for smaller, lower cost satellites which require higher energy density power sources than aerospace nickel-cadmium at a lower cost than space nickel-hydrogen. These include small LEO satellites, tactical military satellites and satellite constellation programs such as Iridium and Brilliant Pebbles. Small satellites typically do not have the spacecraft volume or the budget required for nickel-hydrogen batteries. NiCd's do not have adequate energy density as well as other problems such as overcharge capability and memory effort. Metal hydride batteries provide the ideal solution for these applications. Metal hydride batteries offer a number of advantages over other aerospace battery systems.

  19. Probing the cerium/cerium hydride interface using nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Brierley, Martin, E-mail: martin.brierley@awe.co.uk [Atomic Weapons Establishment, Aldermaston, Berkshire RG7 4PR (United Kingdom); University of Manchester, Manchester M13 9PL (United Kingdom); Knowles, John, E-mail: john.knowles@awe.co.uk [Atomic Weapons Establishment, Aldermaston, Berkshire RG7 4PR (United Kingdom)

    2015-10-05

    Highlights: • A disparity exists between the minimum energy and actual shape of a cerium hydride. • Cerium hydride is found to be harder than cerium metal by a ratio of 1.7:1. • A zone of material under compressive stress was identified surrounding the hydride. • No distribution of hardness was apparent within the hydride. - Abstract: A cerium hydride site was sectioned and the mechanical properties of the exposed phases (cerium metal, cerium hydride, oxidised cerium hydride) were measured using nanoindentation. An interfacial region under compressive stress was observed in the cerium metal surrounding a surface hydride that formed as a consequence of strain energy generated by the volume expansion associated with precipitation of the hydride phase.

  20. Destabilization of magnesium hydride through interface engineering

    OpenAIRE

    Mooij, L.P.A.

    2013-01-01

    The aim of this thesis is to study the thermodynamics of hydrogenation of nanoconfined magnesium within a thin film multilayer model system. Magnesium hydride is a potential material for hydrogen storage, which is a key component in a renewable energy system based on hydrogen. In bulk form, magnesium hydride is very stable, which means that hydrogen is released only at elevated temperature. Furthermore, the kinetics of hydrogen sorption is slow, which further hampers the practical use of this...

  1. Hydrogen generation from magnesium hydride by using organic acid

    Science.gov (United States)

    Ho, Yen-Hsi

    In this paper, the hydrolysis of solid magnesium hydride has been studied with the high concentration of catalyst at the varying temperature. An organic acid (acetic acid, CH3COOH) has been chosen as the catalyst. The study has three objectives: first, using three different weights of MgH 2 react with aqueous solution of acid for the hydrogen generation experiments. Secondly, utilizing acetic acid as the catalyst accelerates hydrogen generation. Third, emphasizing the combination of the three operating conditions (the weight of MgH2, the concentration of acetic acid, and the varying temperature) influence the amount of hydrogen generation. The experiments results show acetic acid truly can increase the rate of hydrogen generation and the weight of MgH2 can affect the amount of hydrogen generation more than the varying temperature.

  2. gamma-Zr-Hydride Precipitate in Irradiated Massive delta- Zr-Hydride

    DEFF Research Database (Denmark)

    Warren, M. R.; Bhattacharya, D. K.

    1975-01-01

    During examination of A Zircaloy-2-clad fuel pin, which had been part of a test fuel assembly in a boiling water reactor, several regions of severe internal hydriding were noticed in the upper-plenum end of the pin. Examination of similar fuel pins has shown that hydride of this type is caused...

  3. Extracting the jet azimuthal anisotropy from higher order cumulants

    CERN Document Server

    Lokhtin, Igor P; Snigirev, A M

    2003-01-01

    We analyze the method for calculation of a coefficient of jet azimuthal anisotropy without reconstruction of the nuclear reaction plane considering the higher order correlators between the azimuthal position of jet axis and the angles of particles not incorporated in the jet. The reliability of this technique in the real physical situation under LHC conditions is illustrated.

  4. Overview of recent azimuthal correlation measurements from ALICE

    CERN Document Server

    INSPIRE-00290856

    2016-01-01

    Azimuthal correlations are a powerful tool to probe the properties and the evolution of the collision system. In this proceedings, we will review the recent azimuthal correlation measurements from ALICE at the LHC. The comparison to other experimental measurements and various theoretical calculations will be discussed as well.

  5. The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components Delayed Hydride Cracking

    CERN Document Server

    Puls, Manfred P

    2012-01-01

    By drawing together the current theoretical and experimental understanding of the phenomena of delayed hydride cracking (DHC) in zirconium alloys, The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components: Delayed Hydride Cracking provides a detailed explanation focusing on the properties of hydrogen and hydrides in these alloys. Whilst the focus lies on zirconium alloys, the combination of both the empirical and mechanistic approaches creates a solid understanding that can also be applied to other hydride forming metals.   This up-to-date reference focuses on documented research surrounding DHC, including current methodologies for design and assessment of the results of periodic in-service inspections of pressure tubes in nuclear reactors. Emphasis is placed on showing that our understanding of DHC is supported by progress across a broad range of fields. These include hysteresis associated with first-order phase transformations; phase relationships in coherent crystalline metallic...

  6. Preliminary development of flaw evaluation procedures for delayed hydride cracking initiation under hydride non-ratcheting conditions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.; Cui, J.; Kawa, D.; Shek, G.K.; Scarth, D.A. [Kinectrics Inc., Toronto, Ontario (Canada)

    2006-07-01

    The flaw evaluation procedure for Delayed Hydride Cracking (DHC) initiation currently provided in the CSA Standard N285.8 was developed for hydride ratcheting conditions, in which flaw-tip hydrides do not completely dissolve at peak temperature. Test results have shown that hydrided regions formed under non-ratcheting conditions, in which flaw-tip hydrides completely dissolve at peak temperature, have significantly higher resistance to cracking than those formed under ratcheting conditions. This paper presents some preliminary work on the development of a procedure for the evaluation of DHC initiation for flaws under hydride non-ratcheting conditions. (author)

  7. White Paper Summary of 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Louthan, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); PNNL, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-29

    This white paper recommends that ASTM International develop standards to address the potential impact of hydrides on the long term performance of irradiated zirconium alloys. The need for such standards was apparent during the 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding and Assembly Components, sponsored by ASTM International Committee C26.13 and held on June 10-12, 2014, in Jackson, Wyoming. The potentially adverse impacts of hydrogen and hydrides on the long term performance of irradiated zirconium-alloy cladding on used fuel were shown to depend on multiple factors such as alloy chemistry and processing, irradiation and post irradiation history, residual and applied stresses and stress states, and the service environment. These factors determine the hydrogen content and hydride morphology in the alloy, which, in turn, influence the response of the alloy to the thermo-mechanical conditions imposed (and anticipated) during storage, transport and disposal of used nuclear fuel. Workshop presentations and discussions showed that although hydrogen/hydride induced degradation of zirconium alloys may be of concern, the potential for occurrence and the extent of anticipated degradation vary throughout the nuclear industry because of the variations in hydrogen content, hydride morphology, alloy chemistry and irradiation conditions. The tools and techniques used to characterize hydrides and hydride morphologies and their impacts on material performance also vary. Such variations make site-to-site comparisons of test results and observations difficult. There is no consensus that a single material or system characteristic (e.g., reactor type, burnup, hydrogen content, end-of life stress, alloy type, drying temperature, etc.) is an effective predictor of material response during long term storage or of performance after long term storage. Multi-variable correlations made for one alloy may not represent the behavior of another alloy exposed to

  8. Mathematical modeling of the nickel/metal hydride battery system

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, Blaine Kermit [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

    1995-09-01

    A group of compounds referred to as metal hydrides, when used as electrode materials, is a less toxic alternative to the cadmium hydroxide electrode found in nickel/cadmium secondary battery systems. For this and other reasons, the nickel/metal hydride battery system is becoming a popular rechargeable battery for electric vehicle and consumer electronics applications. A model of this battery system is presented. Specifically the metal hydride material, LaNi{sub 5}H{sub 6}, is chosen for investigation due to the wealth of information available in the literature on this compound. The model results are compared to experiments found in the literature. Fundamental analyses as well as engineering optimizations are performed from the results of the battery model. In order to examine diffusion limitations in the nickel oxide electrode, a ``pseudo 2-D model`` is developed. This model allows for the theoretical examination of the effects of a diffusion coefficient that is a function of the state of charge of the active material. It is found using present data from the literature that diffusion in the solid phase is usually not an important limitation in the nickel oxide electrode. This finding is contrary to the conclusions reached by other authors. Although diffusion in the nickel oxide active material is treated rigorously with the pseudo 2-D model, a general methodology is presented for determining the best constant diffusion coefficient to use in a standard one-dimensional battery model. The diffusion coefficients determined by this method are shown to be able to partially capture the behavior that results from a diffusion coefficient that varies with the state of charge of the active material.

  9. Thin-film metal hydrides.

    Science.gov (United States)

    Remhof, Arndt; Borgschulte, Andreas

    2008-12-01

    The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis.

  10. High H- ionic conductivity in barium hydride

    Science.gov (United States)

    Verbraeken, Maarten C.; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T. S.

    2015-01-01

    With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H-) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm-1 at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on.

  11. AXIOLOGICAL AZIMUTHS OF THE GLOBAL EDUCATIONAL POLICY

    Directory of Open Access Journals (Sweden)

    Valentyna Bobrytska

    2016-11-01

    Full Text Available Purpose: As the initial point of methodological research the author defines understanding of the essence of value azimuths (orientation, benchmarks in the formation of global education policy seen as a position on the decisive role of consolidation of efforts of supranational structures of the world, civil community in its global dimension, teachers’ associations and educational institutions of different levels in strengthening social and axiological ​​and personality-related and axiological factors of modernization of education as a strategic resource of socio-economic and cultural development of countries, an important lever of civilization development. Methods: In the article there has been used the method of terminological analysis to determine the essential content of the concepts of «value» and «ideal» in projections of development global education policy; the method of theoretical and comparative analysis to review the works of scientists on problems of shaping the global value-based measurements of educational policy. Results: The article presents implications made from the author’s conclusions regarding the content of the concepts of «value» and the «ideal» in projections of the global educational policy. It has been ascertained that the essential characteristics of the concept of «value» are as follows: 1 those are to satisfy the interests and needs of the individual; 2 specific individual reality whose essence lies in its positive significance; 3 «marker» of particular significance of things, processes, ideas for the life of the person; 4 what affects motivation and choice of modes of behavior of man. On the grounds that the term «ideal» denotes excellence, the perfect model, the ultimate goal of aspirations, activities, it has been found that the formation of modes of action, in particular, in the sphere of planning and implementing the global education policy, as far as the ideal is concerned, is a specific

  12. Azimuthal correlations of particles produced in pp collisions at 400GeV/c

    Institute of Scientific and Technical Information of China (English)

    王韶舜

    1996-01-01

    The two particle azimuthal correlations are observed but the azimuthal structure seems to be of stochastic nature.no jet-like structure was observed.And a new method is used to study the azimuthal substructure.

  13. Description of a Photoelectric Rotating Slit Elevation and Azimuth Sensor.

    Science.gov (United States)

    Brown, H E; Brown, P B; Goodson, D W; Cope, J D

    1966-06-01

    The Photoelectric Rotating Slit Elevation and Azimuth Sensor (PERSEAS) measures the azimuth and elevation of the line of sight to a target reflecting or emitting radiation in the 0.4- tol.1-micro portion of the spectrum. Angular field of view is 360 degrees in azimuth and 30 degrees in elevation. Eight stationary lenses are used with rotating fiber-optics slits and silicon photodiode detectors to produce electrical pulses which are time related to target angular coordinates. Data rate is one line-of-sight measurement per 2.5 msec. Accuracy is better than 1 mrad.

  14. Fiber based polarization filter for radially and azimuthally polarized light.

    Science.gov (United States)

    Jocher, Christoph; Jauregui, Cesar; Voigtländer, Christian; Stutzki, Fabian; Nolte, Stefan; Limpert, Jens; Tünnermann, Andreas

    2011-09-26

    We demonstrate a new fiber based concept to filter azimuthally or radially polarized light. This concept is based on the lifting of the modal degeneracy that takes place in high numerical aperture fibers. In such fibers, the radially and azimuthally polarized modes can be spectrally separated using a fiber Bragg grating. As a proof of principle, we filter azimuthally polarized light in a commercially available fiber in which a fiber Bragg grating has been written by a femtosecond pulsed laser. © 2011 Optical Society of America

  15. Synthetic aperture radar images with composite azimuth resolution

    Energy Technology Data Exchange (ETDEWEB)

    Bielek, Timothy P; Bickel, Douglas L

    2015-03-31

    A synthetic aperture radar (SAR) image is produced by using all phase histories of a set of phase histories to produce a first pixel array having a first azimuth resolution, and using less than all phase histories of the set to produce a second pixel array having a second azimuth resolution that is coarser than the first azimuth resolution. The first and second pixel arrays are combined to produce a third pixel array defining a desired SAR image that shows distinct shadows of moving objects while preserving detail in stationary background clutter.

  16. Lattice contraction in photochromic yttrium hydride

    Energy Technology Data Exchange (ETDEWEB)

    Maehlen, Jan Petter, E-mail: jepe@ife.no; Mongstad, Trygve T.; You, Chang Chuan; Karazhanov, Smagul

    2013-12-15

    Highlights: •Photochromic yttrium hydride films (YH:O) were prepared by reactive sputtering. •Black and transparent YH:O films were studied by time-resolved synchrotron XRD. •Both YH:O samples showed a lattice contraction upon illumination. •Also exposure to the X-ray beam itself results in a lattice contraction. -- Abstract: A strong photochromic effect was recently discovered in thin films of oxygen-containing yttrium hydride taking place at room temperature and reacting to ultraviolet and visible light. In this paper, we report on a lattice contraction upon illumination observed for thin-film samples of photochromic yttrium hydride, recorded by time-resolved X-ray diffraction using synchrotron radiation. The time dependence of the lattice contraction is consistent with the observed photochromic response of the samples.

  17. Atom probe analysis of titanium hydride precipitates.

    Science.gov (United States)

    Takahashi, J; Kawakami, K; Otsuka, H; Fujii, H

    2009-04-01

    It is expected that the three-dimensional atom probe (3DAP) will be used as a tool to visualize the atomic scale of hydrogen atoms in steel is expected, due to its high spatial resolution and very low detection limit. In this paper, the first 3DAP analysis of titanium hydride precipitates in metal titanium is reported in terms of the quantitative detection of hydrogen. FIB fabrication techniques using the lift-out method have enabled the production of needle tips of hydride precipitates, of several tens of microns in size, within a titanium matrix. The hydrogen concentration estimated from 3DAP analysis was slightly smaller than that of the hydride phase predicted from the phase diagram. We discuss the origin of the difference between the experimental and predicted values and the performance of 3DAP for the quantitative detection of hydrogen.

  18. Hydrogen storage in complex metal hydrides

    Directory of Open Access Journals (Sweden)

    BORISLAV BOGDANOVIĆ

    2009-02-01

    Full Text Available Complex metal hydrides such as sodium aluminohydride (NaAlH4 and sodium borohydride (NaBH4 are solid-state hydrogen-storage materials with high hydrogen capacities. They can be used in combination with fuel cells as a hydrogen source thus enabling longer operation times compared with classical metal hydrides. The most important point for a wide application of these materials is the reversibility under moderate technical conditions. At present, only NaAlH4 has favourable thermodynamic properties and can be employed as a thermally reversible means of hydrogen storage. By contrast, NaBH4 is a typical non- -reversible complex metal hydride; it reacts with water to produce hydrogen.

  19. Iron Group Hydrides in Noyori Bifunctional Catalysis.

    Science.gov (United States)

    Morris, Robert H

    2016-12-01

    This is an overview of the hydride-containing catalysts prepared in the Morris group for the efficient hydrogenation of simple ketones, imines, nitriles and esters and the asymmetric hydrogenation and transfer hydrogenation of prochiral ketones and imines. The work was inspired by and makes use of Noyori metal-ligand bifunctional concepts involving the hydride-ruthenium amine-hydrogen HRuNH design. It describes the synthesis and some catalytic properties of hydridochloro, dihydride and amide complexes of ruthenium and in one case, osmium, with monodentate, bidentate and tetradentate phosphorus and nitrogen donor ligands. The iron hydride that has been identified in a very effective asymmetric transfer hydrogenation process is also mentioned. The link between the HMNH structure and the sense of enantioinduction is demonstrated by use of simple transition state models.

  20. The effects of structural setting on the azimuthal velocities of blast induced ground motion in perlite

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, S.G. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    1995-02-01

    A series of small scale explosive tests were performed during the spring of 1994 at a perlite mine located near Socorro, NM. The tests were designed to investigate the azimuthal or directional relationship between small scale geologic structures such as joints and the propagation of explosively induced ground motion. Three shots were initiated within a single borehole located at ground zero (gz) at depths varying from the deepest at 83 m (272 ft) to the shallowest at 10 m (32 ft). The intermediate shot was initiated at a depth of 63 m (208 ft). An array of three component velocity and acceleration transducers were placed in two concentric rings entirely surrounding the single shot hole at 150 and 300 azimuths as measured from ground zero. Data from the transducers was then used to determine the average propagation velocity of the blast vibration through the rock mass at the various azimuths. The rock mass was mapped to determine the prominent joint orientations (strike and dip) and the average propagation velocities were correlated with this geologic information. The data from these experiments shows that there is a correlation between the orientation of prominent joints and the average velocity of ground motion. It is theorized that this relationship is due to the relative path the ground wave follows when encountering a joint or structure within the rock mass. The more prominent structures allow the wave to follow along their strike thereby forming a sort of channel or path of least resistance and in turn increasing the propagation velocity. Secondary joints or structures may act in concert with more prominent features to form a network of channels along which the wave moves more freely than it may travel against the structure. The amplitudes of the ground motion was also shown to vary azimuthally with the direction of the most prominent structures.

  1. Thermodynamic properties of the cubic plutonium hydride solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Haschke, J M

    1981-12-01

    Pressure, temperature, and composition data for the cubic solid solution plutonium hydride phase, PuH/sub x/, have been measured by microbalance methods. Integral enthalpies and entropies of formation have been evaluated for the composition range 1.90 less than or equal to X less than or equal to 3.00. At 550/sup 0/K, ..delta..H/sup 0/ /sub f/(PuH/sub x/(s)) varies linearly from approximately (-38 +- 1) kcal mol/sup -1/ at PuH/sub 190/ to (-50 +- 1 kcal mol/sup -1/) at PuH/sub 3/ /sub 00/. Thermochemical values obtained by reevaluating tensimetric data from the literature are in excellent agreement with these results. Isotopic effects have been quantified by comparing the results for hydride and deuteride, and equations are presented for predicting ..delta..H/sup 0/ /sub f/ and ..delta..S/sup 0/ /sub f/ values for PuH/sub x/(s) and PuD/sub x/(s).

  2. Varying Constants

    CERN Document Server

    Damour, Thibault Marie Alban Guillaume

    2003-01-01

    We review some string-inspired theoretical models which incorporate a correlated spacetime variation of coupling constants while remaining naturally compatible both with phenomenological constraints coming from geochemical data (Oklo; Rhenium decay) and with present equivalence principle tests. Barring unnatural fine-tunings of parameters, a variation of the fine-structure constant as large as that recently ``observed'' by Webb et al. in quasar absorption spectra appears to be incompatible with these phenomenological constraints. Independently of any model, it is emphasized that the best experimental probe of varying constants are high-precision tests of the universality of free fall, such as MICROSCOPE and STEP. Recent claims by Bekenstein that fine-structure-constant variability does not imply detectable violations of the equivalence principle are shown to be untenable.

  3. Evidence of stress-induced hydrogen ordering in zirconium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Steuwer, A. [FaME38 at the ESRF-ILL, 6 rue J Horowitz, 38042 Grenoble (France); ESS Scandinavia, University of Lund, Stora Algatan 4, 22350 Lund (Sweden)], E-mail: steuwer@ill.fr; Santisteban, J.R. [Centro Atomico Bariloche, CNEA, San Carlos de Bariloche (Argentina); Preuss, M. [University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Peel, M.J.; Buslaps, T. [European Synchrotron Radiation Facility, 6 rue J Horowitz, 38042 Grenoble (France); Harada, M. [R and D Section, Chofu-Kita Plant, Kobe Special Tube Co, Shimonoseki 752-0953 (Japan)

    2009-01-15

    The formation of hydrides in zirconium alloys significantly affects their mechanical properties and is considered to play a critical role in their failure mechanisms, yet relatively little is known about the micromechanical behavior of hydrides in the bulk. This paper presents the result of in situ uniaxial mechanical tensioning experiments on hydrided zircaloy-2 and zircaloy-4 specimens using energy-dispersive synchrotron X-ray diffraction, which suggests that a stress-induced transformation of the {delta}-hydride to {gamma}-hydride via ordering of the hydrogen atoms occurs, akin to a Snoek-type relaxation. Subsequent annealing was found to reverse the ordering phenomenon.

  4. Fiber-optic gyro location of dome azimuth

    Science.gov (United States)

    Kuehne, John W.

    2016-07-01

    The 2.1-m Otto Struve Telescope, world's second largest in 1939, today has modern motion control and superb tracking, yet the 19-m-diameter Art Deco dome has resisted many attempts to record its azimuth electronically. Demonstrated in January 2016, a small tactical-grade fiber-optic gyro located anywhere on the rotating structure, aided by a few fiducial points to zero gyro drift, adequately locates the azimuth. The cost of a gyro is practically independent of dome size, offering an economical solution for large domes that cannot be easily encoded with conventional systems. The 100-Hz sampling is capable of revealing anomalies in the rotation rate, valuable for preventive maintenance on any dome. I describe software methods and time series analysis to integrate angular velocity to dome azimuth; transformation of telescope hour angle and declination into required dome azimuth, using a formula that accounts for a cross-axis mount inside an offset dome; and test results.

  5. Jet quenching and high-pt azimuthal asymmetry

    CERN Document Server

    Lokhtin, Igor P; Vitev, I

    2002-01-01

    The azimuthal anisotropy of high-pt particle production in non-central heavy ion collisions is among the most promising observables of partonic energy loss in an azimuthally non-symmetric volume of quark-gluon plasma. We discuss the implications of nuclear geometry for the models of partonic energy loss in the context of recent RHIC data and consequences for observation of jet quenching at the LHC.

  6. Azimuthal Correlation of Collective Motion in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    HUO Lei; ZHANG Wei-Ning; CHEN Xiang-Jun; TANG Gui-Xin; ZHANG Jing-Bo

    2001-01-01

    The out-of-plane squeeze-out effect in relativistic heavy ion collisions is used to estimate the reaction plane by performing a modified transverse momentum analysis. A technique for investigating the azimuthal correlation between the out-of-plane squeeze-out and directed in-plane flow is described. A clear signature of the azimuthal correlation is evidenced in the 600 A MeV Au + Au reaction from the quantum molecular dynamic model calculations.

  7. Azimuth Phase Coding for Range Ambiguity Suppression in SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Kusk, Anders

    2004-01-01

    A novel ambiguity suppression technique is proposed. Range ambiguities in synthetic aperture radar (SAR) images are eliminated with an azimuth filter after having applied an azimuth phase modulation to the transmitted pulses and a corresponding demodulation to the received pulses. The technique...... by the antenna elevation dimension. The fundamental antenna area constraint still applies, but the PRF can be chosen with more freedom. In addition to ambiguity suppression, potential applications include nadir return elimination and signal-to-noise ratio improvement....

  8. Application of thermal electrochemical equation to metal-hydride half-cell system

    Institute of Scientific and Technical Information of China (English)

    LIU Kai-yu; HUANG Bai-yun; ZHANG Ping-min; HE Yue-hui; ZHOU Ke-chao; SU Geng

    2006-01-01

    Application of thermal electrochemical equation to metal-hydride half-cell system was investigated, and the influence of state of charge on the thermal electrochemical performance of hydrogen storage materials was studied. The results show that both the absolute value of the molar enthalpy change and the internal resistance of evolution hydrogen reaction are less than that of absorption hydrogen reaction at the same state of charge. The molar reaction enthalpy change of absorption and evolution of hydride electrode change contrarily with the enhancement of filling degree of hydrogen in hydride electrode. The relation curve of molar reaction enthalpy change to state of charge, both absorption and evolution hydrogen reaction, is close to a constant when the state of charge is 10%-60%, and during state of charge below 10% or state of charge above 60%, the molar reaction enthalpy change varies sharply. Meanwhile, the internal resistance of electrode reaction has an ascending trend with the enhancement on filling degree of hydrogen in hydride electrode in both absorption and evolution hydrogen reaction.

  9. Model for the Prediction of the Hydriding Thermodynamics of Pd-Rh-Co Ternary Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Teter, D.F.; Thoma, D.J.

    1999-03-01

    A dilute solution model (with respect to the substitutional alloying elements) has been developed, which accurately predicts the hydride formation and decomposition thermodynamics and the storage capacities of dilute ternary Pd-Rh-Co alloys. The effect of varying the rhodium and cobalt compositions on the thermodynamics of hydride formation and decomposition and hydrogen capacity of several palladium-rhodium-cobalt ternary alloys has been investigated using pressure-composition (PC) isotherms. Alloying in the dilute regime (<10 at.%) causes the enthalpy for hydride formation to linearly decrease with increasing alloying content. Cobalt has a stronger effect on the reduction in enthalpy than rhodium for equivalent alloying amounts. Also, cobalt reduces the hydrogen storage capacity with increasing alloying content. The plateau thermodynamics are strongly linked to the lattice parameters of the alloys. A near-linear dependence of the enthalpy of hydride formation on the lattice parameter was observed for both the binary Pd-Rh and Pd-Co alloys, as well as for the ternary Pd-Rh-Co alloys. The Pd-5Rh-3Co (at. %) alloy was found to have similar plateau thermodynamics as a Pd-10Rh alloy, however, this ternary alloy had a diminished hydrogen storage capacity relative to Pd-10Rh.

  10. The development of nickel-metal hydride technology for use in aerospace applications

    Science.gov (United States)

    Rampel, Guy; Johnson, Herschel; Dell, Dan; Wu, Tony; Puglisi, Vince

    1992-01-01

    The nickel metal hydride technology for battery application is relatively immature even though this technology was made widely known by Philips' scientists as long ago as 1970. Recently, because of the international environmental regulatory pressures being placed on cadmium in the workplace and in disposal practices, battery companies have initiated extensive development programs to make this technology a viable commercial operation. These hydrides do not pose a toxilogical threat as does cadmium. Also, they provide a higher energy density and specific energy when compared to the other nickel based battery technologies. For these reasons, the nickel metal hydride electrochemisty is being evaluated as the next power source for varied applications such as laptop computers, cellular telephones, electric vehicles, and satellites. A parallel development effort is under way to look at aerospace applications for nickel metal hydride cells. This effort is focused on life testing of small wound cells of the commercial type to validate design options and development of prismatic design cells for aerospace applications.

  11. Hydride formation on deformation twin in zirconium alloy

    Science.gov (United States)

    Kim, Ju-Seong; Kim, Sung-Dae; Yoon, Jonghun

    2016-12-01

    Hydrides deteriorate the mechanical properties of zirconium (Zr) alloys used in nuclear reactors. Intergranular hydrides that form along grain boundaries have been extensively studied due to their detrimental effects on cracking. However, it has been little concerns on formation of Zr hydrides correlated with deformation twins which is distinctive heterogeneous nucleation site in hexagonal close-packed metals. In this paper, the heterogeneous precipitation of Zr hydrides at the twin boundaries was visualized using transmission electron microscopy. It demonstrates that intragranular hydrides in the twinned region precipitates on the rotated habit plane by the twinning and intergranular hydrides precipitate along the coherent low energy twin boundaries independent of the conventional habit planes. Interestingly, dislocations around the twin boundaries play a substantial role in the nucleation of Zr hydrides by reducing the misfit strain energy.

  12. Optical properties of the cirrus cloud ice crystals with preferred azimuthal orientation for polarization lidars with azimuthal scanning

    Science.gov (United States)

    Konoshonkin, Alexander V.; Kustova, Natalia V.; Nasonov, Sergey V.; Bryukhanov, Ilia D.; Shishko, Viktor A.; Timofeev, Dmitriy N.; Borovoi, Anatoly G.

    2016-10-01

    Optical properties of the cirrus cloud ice crystals with preferred azimuthal orientation are required for current numerical models of the Earth's radiation balance. Retrieving the orientation distributions function of the crystals from a vertically pointing polarization lidar measuring the full Mueller matrix is a very complicated problem because of lake of information. Lidars with zenith scanning can be used only to retrieve the properties of horizontally oriented particles. The paper shows that if the particles have preferred azimuthal orientation, the polarization lidars with azimuthal scanning should be used. It is also shown that all the elements of the Mueller matrix give no extra information compare to the depolarization ratio. Optical properties of preferred azimuthal oriented hexagonal ice columns with size from 10 to 1000 μm for wavelengths of 0.355, 0.532 and 1.064 μm were collected as a data bank.

  13. Destabilization of magnesium hydride through interface engineering

    NARCIS (Netherlands)

    Mooij, L.P.A.

    2013-01-01

    The aim of this thesis is to study the thermodynamics of hydrogenation of nanoconfined magnesium within a thin film multilayer model system. Magnesium hydride is a potential material for hydrogen storage, which is a key component in a renewable energy system based on hydrogen. In bulk form,

  14. Destabilization of magnesium hydride through interface engineering

    NARCIS (Netherlands)

    Mooij, L.P.A.

    2013-01-01

    The aim of this thesis is to study the thermodynamics of hydrogenation of nanoconfined magnesium within a thin film multilayer model system. Magnesium hydride is a potential material for hydrogen storage, which is a key component in a renewable energy system based on hydrogen. In bulk form, magnesiu

  15. Destabilization of magnesium hydride through interface engineering

    NARCIS (Netherlands)

    Mooij, L.P.A.

    2013-01-01

    The aim of this thesis is to study the thermodynamics of hydrogenation of nanoconfined magnesium within a thin film multilayer model system. Magnesium hydride is a potential material for hydrogen storage, which is a key component in a renewable energy system based on hydrogen. In bulk form, magnesiu

  16. A Mode Detection Method Using the Azimuthal Directivity of a Turbofan Model

    Science.gov (United States)

    Thomas, R. H.; Farassat, F.; Clark, L. R.; Gerhold, C. H.; Kelly, J. J.; Becker, L. E.

    1999-01-01

    The azimuthal, far field directivity of a scale fan model was measured in high resolution. The model is a 12 inch diameter rotor with 16 blades followed by 40 stator vanes. The tests were conducted at the nominal 100% speed corresponding to a tip speed of 905 ft/sec. Measurement of the radiated sound field, forward of the fan, was made in an anechoic chamber with an inflow control device and a baffle separating the aft and forward radiated interaction noise. The acoustic field was surveyed with a circular hoop array of 16 microphones which was moved to 14 axial stations. At each axial station the hoop was rotated in half-degree increments to take 736 points in the azimuthal angle. In addition to sound pressure level, the phase angle relative to a reference microphone was measured at each point. The sound pressure level is shown to vary in patterns by 10-15 dB especially for the fundamental tone but also for the first and second harmonic. A far field mode detection method has been developed and used with the data which determines the modes generated by the fan and which then interact to form the azimuthal directivity.

  17. Development of a metal hydride refrigeration system as an exhaust gas-driven automobile air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Feng; Chen, Jiangping; Chen, Zhijiu [Institute of Refrigeration and Cryogenics Engineering, Shanghai Jiaotong University, Shanghai 200030 (China); Lu, Manqi; Yang, Ke [Engineering Center, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, Liaoning Province 110016 (China); Zhou, Yimin [Research Center, Zhejiang Yinlun Machinery Co. Ltd., Tiantai County, Zhejiang Province 317200 (China)

    2007-10-15

    Aiming at developing exhaust gas-driven automobile air conditioners, two types of systems varying in heat carriers were preliminarily designed. A new hydride pair LaNi{sub 4.61}Mn{sub 0.26}Al{sub 0.13}/La{sub 0.6}Y{sub 0.4}Ni{sub 4.8}Mn{sub 0.2} was developed working at 120-200 C/20-50 C/-10-0 C. P-C isotherms and reaction kinetics were tested. Reaction enthalpy, entropy and theoretical cycling coefficient of performance (COP) were deducted from Van't-Hoff diagram. Test results showed that the hydride pair has flat plateau slopes, fast reaction dynamics and small hystereses; the reaction enthalpy of the refrigeration hydride is -27.1 kJ/mol H{sub 2} and system theoretical COP is 0.711. Mean particle sizes during cycles were verified to be an intrinsic property affected by constitution, heat treatment and cycle numbers rather than initial grain sizes. Based on this work pair, cylindrical reactors were designed and a function proving metal hydride intermittent refrigeration system was constructed with heat conducting oil as heat source and water as heat sink. The reactor equivalent thermal conductivity is merely 1.3 W/(m K), which still has not meet practical requirement. Intermittent refrigeration cycles were achieved and the average cooling power is 84.6 W at 150 C/30 C/0 C with COP being 0.26. The regulations of cycling performance and minimum refrigeration temperature (MRT) were determined by altering heat source temperature. Results showed that cooling power and system COP increase while MRT decreases with the growth of heat source temperature. This study develops a new hydride pair and confirms its application in automobile refrigeration systems, while their heat transfer properties still need to be improved for better performance. (author)

  18. Topological states in partially-PT-symmetric azimuthal potentials

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2015-01-01

    We introduce partially-parity-time-symmetric (pPT-symmetric) azimuthal potentials composed from individual PT-symmetric cells located on a ring, where two azimuthal directions are nonequivalent in a sense that in such potentials excitations carrying topological dislo-cations exhibit different dynamics for different directions of energy circulation in the initial field distribution. Such non-conservative ratchet-like structures support rich families of stable vortex solitons in cubic nonlinear media, whose properties depend on the sign of the topological charge due to the nonequivalence of azimuthal directions. In contrast, oppositely charged vortex solitons remain equivalent in similar fully PT-symmetric potentials. The vortex solitons in the pPT- and PT-symmetric potentials are shown to feature qualitatively different internal current distributions, which are described by different discrete rotation symmetries of the intensity profiles.

  19. Numerical study of a magnesium hydride tank

    Science.gov (United States)

    Delhomme, Baptiste; de Rango, Patricia; Marty, Philippe

    2012-11-01

    Hydrogen storage in metal hydride tanks (MHT) is a very promising solution. Several experimental tanks, studied by different teams, have already proved the feasibility and the interesting performances of this solution. However, in much cases, an optimization of tank geometry is still needed in order to perform fast hydrogen loading. The development of efficient numerical tools is a key issue for MHT design and optimization. We propose a simple model representing a metal hydride tank exchanging its heat of reaction with a thermal fluid flow. In this model, the radial and axial discretisations have been decoupled by using Matlab® one-dimensional tools. Calculations are compared to experimental results obtained in a previous study. A good agreement is found for the loading case. The discharging case shows some discrepancies, which are discussed in this paper.

  20. The electrochemical impedance of metal hydride electrodes

    DEFF Research Database (Denmark)

    Valøen, Lars Ole; Lasia, Andrzej; Jensen, Jens Oluf

    2002-01-01

    The electrochemical impedance responses for different laboratory type metal hydride electrodes were successfully modeled and fitted to experimental data for AB5 type hydrogen storage alloys as well as one MgNi type electrode. The models fitted the experimental data remarkably well. Several AC......, explaining the experimental impedances in a wide frequency range for electrodes of hydride forming materials mixed with copper powder, were obtained. Both charge transfer and spherical diffusion of hydrogen in the particles are important sub processes that govern the total rate of the electrochemical...... hydrogen absorption/desorption reaction. To approximate the experimental data, equations describing the current distribution in porous electrodes were needed. Indications of one or more parallel reduction/oxidation processes competing with the electrochemical hydrogen absorption/desorption reaction were...

  1. Azimuthal instabilities of the Gribov-Levin-Ryskin equation

    Energy Technology Data Exchange (ETDEWEB)

    Gambini, Guillermo; Torrieri, Giorgio [State University of Campinas, IFGW, Campinas (Brazil)

    2017-01-15

    We introduce the phenomenology of elliptic flow in nuclear collisions, and argue that its scaling across energies, rapidities and system sizes could be suggestive of a QCD-based rather than a hydrodynamical explanation. As a hypothesis for such an explanation, we show that the GLR equation develops unstable modes when the parton distribution function is generalized to depend on azimuthal angle. This generally means that the structure function acquires an azimuthal dependence. We argue that this process is a plausible alternative explanation for the origin of elliptic flow, one that naturally respects the scaling experimentally observed. (orig.)

  2. Azimuthal dependence of collective expansion for symmetric heavy ion collisions

    CERN Document Server

    Stoicea, G; Andronic, A; Herrmann, N; Alard, J P; Basrak, Z; Barret, V; Bastid, N; Caplar, R; Crochet, Philippe; Dupieux, P; Dzelalija, M; Fodor, Z; Hartmann, O; Hildenbrand, K D; Hong, B; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Korolija, M; Kotte, R; Kress, T; Lebedev, A; Leifels, Y; López, X; Merschmeyer, M; Neubert, W; Pelte, D; Ramires, F; Reisdorf, W; Schull, D; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V T; Stockmeier, M R; Wisniewski, K; Wohlfarth, D; Yushmanov, I E; Zhilin, A; Danielewicz, P

    2004-01-01

    Detailed studies of the azimuthal dependence of the mean fragment and flow energies in the Au+Au and Xe+CsI systems are reported as a function of incident energy and centrality. Comparisons between data and model calculations show that the flow energy values along different azimuthal directions could be viewed as snapshots of the fireball expansion with different exposure times. For the same number of participating nucleons more transversally elongated participant shapes from the heavier system produce less collective transverse energy. Good agreement with BUU calculations is obtained for a soft nuclear equation of state.

  3. Nickel metal hydride LEO cycle testing

    Science.gov (United States)

    Lowery, Eric

    1995-01-01

    The George C. Marshall Space Flight Center is working to characterize aerospace AB5 Nickel Metal Hydride (NiMH) cells. The cells are being evaluated in terms of storage, low earth orbit (LEO) cycling, and response to parametric testing (high rate charge and discharge, charge retention, pulse current ability, etc.). Cells manufactured by Eagle Picher are the subjects of the evaluation. There is speculation that NiMH cells may become direct replacements for current Nickel Cadmium cells in the near future.

  4. Storing hydrogen in the form of light alloy hydrides

    Science.gov (United States)

    Freund, E.; Gillerm, C.

    1981-01-01

    Different hydrides are investigated to find a system with a sufficiently high storage density (at least 3%). The formation of hydrides with light alloys is examined. Reaction kinetics for hydride formation were defined and applied to the systems Mg-Al-H, Mg-Al-Cu-H, Ti-Al-H, Ti-Al-Cu-H, and Ti-Al-Ni-H. Results indicate that the addition of Al destabilizes MgH2 and TiH2 hydrides while having only a limited effect on the storage density.

  5. Plasmonic hydrogen sensing with nanostructured metal hydrides.

    Science.gov (United States)

    Wadell, Carl; Syrenova, Svetlana; Langhammer, Christoph

    2014-12-23

    In this review, we discuss the evolution of localized surface plasmon resonance and surface plasmon resonance hydrogen sensors based on nanostructured metal hydrides, which has accelerated significantly during the past 5 years. We put particular focus on how, conceptually, plasmonic resonances can be used to study metal-hydrogen interactions at the nanoscale, both at the ensemble and at the single-nanoparticle level. Such efforts are motivated by a fundamental interest in understanding the role of nanosizing on metal hydride formation processes in the quest to develop efficient solid-state hydrogen storage materials with fast response times, reasonable thermodynamics, and acceptable long-term stability. Therefore, a brief introduction to the thermodynamics of metal hydride formation is also given. However, plasmonic hydrogen sensors not only are of academic interest as research tool in materials science but also are predicted to find more practical use as all-optical gas detectors in industrial and medical applications, as well as in a future hydrogen economy, where hydrogen is used as a carbon free energy carrier. Therefore, the wide range of different plasmonic hydrogen sensor designs already available is reviewed together with theoretical efforts to understand their fundamentals and optimize their performance in terms of sensitivity. In this context, we also highlight important challenges to be addressed in the future to take plasmonic hydrogen sensors from the laboratory to real applications in devices, including poisoning/deactivation of the active materials, sensor lifetime, and cross-sensitivity toward other gas species.

  6. A phase-field model to study the effects of temperature change on shape evolution of γ-hydrides in zirconium

    Science.gov (United States)

    Bair, Jacob; Asle Zaeem, Mohsen; Tonks, Michael

    2016-10-01

    A temperature-dependent phase-field model is developed to study the effects of temperature change on shape evolution of γ-hydrides in an α-zirconium matrix. To construct the temperature-dependent free energy functional of the phase-field model, Gibbs free energies of formation from previous experiments are employed, and one conserved and three non-conserved phase-field variables are used for hydrogen concentration and hydride orientations, respectively. The mixed order evolution equations of phase-field variables coupled with mechanical equilibrium equations are solved in a finite element framework. Results from isothermal simulations of seeded and random nucleation in single crystal α-zirconium matrix show that the thickness of non-equilibrium hydrides varies with temperature during evolution, and the hydrides are more rod-like (thinner) at higher temperatures and thicker at lower temperatures. Quench simulations with random nucleation indicate that the majority of precipitation occurs at early stages of quenching, but the size and shape of hydrides change as the temperature decreases. Simulations from random nucleation of hydrides in a polycrystalline α-zirconium matrix show a higher concentration of precipitates along high angle grain boundaries.

  7. Stationary MHD equilibria describing azimuthal rotations in symmetric plasmas

    Science.gov (United States)

    da Silva, Sidney T.; Viana, Ricardo L.

    2016-12-01

    We consider the stationary magnetohydrodynamical (MHD) equilibrium equation for an axisymmetric plasma undergoing azimuthal rotations. The case of cylindrical symmetry is treated, and we present two semi-analytical solutions for the stationary MHD equilibrium equations, from which a number of physical properties of the magnetically confined plasma are derived.

  8. Relative azimuth inversion by way of damped maximum correlation estimates

    Science.gov (United States)

    Ringler, A.T.; Edwards, J.D.; Hutt, C.R.; Shelly, F.

    2012-01-01

    Horizontal seismic data are utilized in a large number of Earth studies. Such work depends on the published orientations of the sensitive axes of seismic sensors relative to true North. These orientations can be estimated using a number of different techniques: SensOrLoc (Sensitivity, Orientation and Location), comparison to synthetics (Ekstrom and Busby, 2008), or by way of magnetic compass. Current methods for finding relative station azimuths are unable to do so with arbitrary precision quickly because of limitations in the algorithms (e.g. grid search methods). Furthermore, in order to determine instrument orientations during station visits, it is critical that any analysis software be easily run on a large number of different computer platforms and the results be obtained quickly while on site. We developed a new technique for estimating relative sensor azimuths by inverting for the orientation with the maximum correlation to a reference instrument, using a non-linear parameter estimation routine. By making use of overlapping windows, we are able to make multiple azimuth estimates, which helps to identify the confidence of our azimuth estimate, even when the signal-to-noise ratio (SNR) is low. Finally, our algorithm has been written as a stand-alone, platform independent, Java software package with a graphical user interface for reading and selecting data segments to be analyzed.

  9. Fiber amplification of radially and azimuthally polarized laser light

    CERN Document Server

    Fridman, Moti; Dubinskiy, Mark; Friesem, Asher A; Davidson, Nir

    2010-01-01

    The results on amplifying either radially or azimuthally polarized light with a fiber amplifier are presented. Experimental results reveal that more than 85% polarization purity can be retained at the output even with 40dB amplification, and that efficient conversion of the amplified light to linear polarization can be obtained.

  10. The azimuthal decorrelation of forward jets in deep inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sabio Vera, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Schwennsen, F. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2007-08-15

    We study the azimuthal angle decorrelation of forward jets in Deep Inelastic Scattering. We make predictions for this observable at HERA describing the high energy limit of the relevant scattering amplitudes with quasi-multi-Regge kinematics together with a collinearly improved evolution kernel for multiparton emissions. (orig.)

  11. Pseudorapidity Dependence of Anisotropic Azimuthal Flow with the ALICE Detector

    DEFF Research Database (Denmark)

    Hansen, Alexander Colliander

    In ultra-relativistic heavy-ion collisions a new state of matter known as the strongly interacting quark-gluon plasma (sQGP) is produced. A key observable in the study of the sQGP is anisotropic azimuthal ow. The anisotropies are described by ow harmonics, vn. In this thesis, bias arising from non...

  12. Heavy-flavor azimuthal correlations of D mesons

    CERN Document Server

    Nahrgang, Marlene; Gossiaux, Pol Bernard; Werner, Klaus

    2013-01-01

    Observables of heavy-quark azimuthal correlations in heavy-ion collisions are a new and promising tool for the investigation of the in-medium energy loss. We explore the potential of these observables to discriminate the collisional and radiative contributions within a hybrid EPOS+MC@sHQ transport approach.

  13. Sparse synthetic aperture radar imaging with optimized azimuthal aperture

    Institute of Scientific and Technical Information of China (English)

    ZENG Cao; WANG MinHang; LIAO GuiSheng; ZHU ShengQi

    2012-01-01

    To counter the problem of acquiring and processing huge amounts of data for synthetic aperture radar (SAR) using traditional sampling techniques,a method for sparse SAR imaging with an optimized azimuthal aperture is presented.The equivalence of an azimuthal match filter and synthetic array beamforming is shown so that optimization of the azimuthal sparse aperture can be converted to optimization of synthetic array beamforming.The azimuthal sparse aperture,which is composed of a middle aperture and symmetrical bilateral apertures,can be obtained by optimization algorithms (density weighting and simulated annealing algorithms,respectively).Furthermore,sparse imaging of spectrum analysis SAR based on the optimized sparse aperture is achieved by padding zeros at null samplings and using a non-uniform Taylor window. Compared with traditional sampling,this method has the advantages of reducing the amount of sampling and alleviating the computational burden with acceptable image quality.Unlike periodic sparse sampling,the proposed method exhibits no image ghosts.The results obtained from airborne measurements demonstrate the effectiveness and superiority of the proposed method.

  14. Robust improvement of target resolution in azimuth and range

    NARCIS (Netherlands)

    Ruggiano, M.

    2011-01-01

    This thesis addresses the development of a robust processing technique aimed at resolving and unmasking targets, in range and azimuth, embedded in the received signal of a single and monostatic rotating surveillance radar. The reason for the need of such technique is twofold. Firstly, there are

  15. 14 CFR 171.313 - Azimuth performance requirements.

    Science.gov (United States)

    2010-01-01

    ... degree. From the approach reference datum to the coverage limit, the PFE, PFN and CMN limits, expressed... runway centerline extended, by a factor of 1.2 for the PFE and PFN limits and to ±0.10 degree for the CMN... degree azimuth angles for the PFE, PFN and CMN limits. (iii) With elevation angle from +9 degrees to +15...

  16. Robust improvement of target resolution in azimuth and range

    NARCIS (Netherlands)

    Ruggiano, M.

    2011-01-01

    This thesis addresses the development of a robust processing technique aimed at resolving and unmasking targets, in range and azimuth, embedded in the received signal of a single and monostatic rotating surveillance radar. The reason for the need of such technique is twofold. Firstly, there are seve

  17. Method of making crack-free zirconium hydride

    Science.gov (United States)

    Sullivan, Richard W.

    1980-01-01

    Crack-free hydrides of zirconium and zirconium-uranium alloys are produced by alloying the zirconium or zirconium-uranium alloy with beryllium, or nickel, or beryllium and scandium, or nickel and scandium, or beryllium and nickel, or beryllium, nickel and scandium and thereafter hydriding.

  18. Creating nanoshell on the surface of titanium hydride bead

    Directory of Open Access Journals (Sweden)

    PAVLENKO Vyacheslav Ivanovich

    2016-12-01

    Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

  19. Hydrogen storage in the form of metal hydrides

    Science.gov (United States)

    Zwanziger, M. G.; Santana, C. C.; Santos, S. C.

    1984-01-01

    Reversible reactions between hydrogen and such materials as iron/titanium and magnesium/ nickel alloy may provide a means for storing hydrogen fuel. A demonstration model of an iron/titanium hydride storage bed is described. Hydrogen from the hydride storage bed powers a converted gasoline electric generator.

  20. Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed

    Directory of Open Access Journals (Sweden)

    Thirugnasambandam G. Manivasagam

    2012-10-01

    Full Text Available As potential hydrogen storage media, magnesium based hydrides have been systematically studied in order to improve reversibility, storage capacity, kinetics and thermodynamics. The present article deals with the electrochemical and optical properties of Mg alloy hydrides. Electrochemical hydrogenation, compared to conventional gas phase hydrogen loading, provides precise control with only moderate reaction conditions. Interestingly, the alloy composition determines the crystallographic nature of the metal-hydride: a structural change is induced from rutile to fluorite at 80 at.% of Mg in Mg-TM alloy, with ensuing improved hydrogen mobility and storage capacity. So far, 6 wt.% (equivalent to 1600 mAh/g of reversibly stored hydrogen in MgyTM(1-yHx (TM: Sc, Ti has been reported. Thin film forms of these metal-hydrides reveal interesting electrochromic properties as a function of hydrogen content. Optical switching occurs during (dehydrogenation between the reflective metal and the transparent metal hydride states. The chronological sequence of the optical improvements in optically active metal hydrides starts with the rare earth systems (YHx, followed by Mg rare earth alloy hydrides (MgyGd(1-yHx and concludes with Mg transition metal hydrides (MgyTM(1-yHx. In-situ optical characterization of gradient thin films during (dehydrogenation, denoted as hydrogenography, enables the monitoring of alloy composition gradients simultaneously.

  1. High energy density battery based on complex hydrides

    Science.gov (United States)

    Zidan, Ragaiy

    2016-04-26

    A battery and process of operating a battery system is provided using high hydrogen capacity complex hydrides in an organic non-aqueous solvent that allows the transport of hydride ions such as AlH.sub.4.sup.- and metal ions during respective discharging and charging steps.

  2. High energy density battery based on complex hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Zidan, Ragaiy

    2016-04-26

    A battery and process of operating a battery system is provided using high hydrogen capacity complex hydrides in an organic non-aqueous solvent that allows the transport of hydride ions such as AlH.sub.4.sup.- and metal ions during respective discharging and charging steps.

  3. Synthesis, characterization and properties of some organozinc hydride complexes

    NARCIS (Netherlands)

    Koning, A.J. de; Boersma, J.; Kerk, G.J.M. van der

    1980-01-01

    The synthesis and characterization of the monopyridine complexes of ethylzinc hydride and phenylzinc hydride are described. On treatment with TMED these complexes are converted into R2Zn3H4. TMED species through a combination of ligand-exchange and disproportionation. The formation of organozinc hyd

  4. Hydride morphology and striation formation during delayed hydride cracking in Zr-2.5% Nb

    Energy Technology Data Exchange (ETDEWEB)

    Shek, G.K. [Ontario Hydro Technol., Ont. (Canada). Mater. Technol. Unit; Jovanovic, M.T. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mining, Metallurgical and Petroleum Engineering; Seahra, H. [Ontario Hydro Technol., Ont. (Canada). Mater. Technol. Unit; Ma, Y. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mining, Metallurgical and Petroleum Engineering; Li, D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mining, Metallurgical and Petroleum Engineering; Eadie, R.L. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mining, Metallurgical and Petroleum Engineering

    1996-08-01

    These experiments were designed to study hydride formation at the crack tip, acoustic emission (AE), potential drop (PD) and striation formation during DHC (delayed hydride cracking) in Zr-2.5% Nb. The test material was taken from an especially extruded pressure tube, which showed similar strength properties to normal pressure tube material but somewhat coarser microstructure. In testing at K{sub I} below 12 MPa {radical}m at both 200 and 250 C very large striations (>40 {mu}m at 200 and >50 {mu}m at 250 C) were produced. In simultaneous monitoring with acoustic emission and potential drop, both AE and PD jumps were shown to be monolithic. The number of striations on the fracture surface corresponded to the number of monolithic AE/PD jumps. Tapered shaped hydrides with the thick end adjacent to the crack tip were observed. These hydrides grew in size during the incubation period until they reached the striation length and then fractured monolithically. However, when K{sub I} was increased beyond about 12 MPa {radical}m for these same specimens, the striation spacing decreased below 30 {mu}m, the monolithic jumping dissolved into more continuous changes in signals, although the smaller striations were still visible on the fracture surface. (orig.).

  5. Hydride morphology and striation formation during delayed hydride cracking in Zr-2.5% Nb

    Science.gov (United States)

    Shek, G. K.; Jovanoviċ, M. T.; Seahra, H.; Ma, Y.; Li, D.; Eadie, R. L.

    1996-08-01

    These experiments were designed to study hydride formation at the crack tip, acoustic emission (AE), potential drop (PD) and striation formation during DHC (delayed hydride cracking) in Zr-2.5% Nb. The test material was taken from an especially extrude pressure tube, which showed similar strength properties to normal pressure tube material but somewhat coarser microstructure. In testing at KI below 12 MPa √m at both 200 and 250°C very large striations (> 40 μ at 200 and >50 μm at 250°C) were produced. In simultaneous monitoring with acoustic emission and potential drop, both AE and PD jumps were shown to be monolithic. The number of striations on the fracture surface corresponded to the number of monolithic AE/PD jumps. Tapered shaped hydrides with the thick end adjacent to the crack tip were observed. These hydrides grew in size during the incubation period until they reached the striation length and then fractured monolithically. However, when KI was increased beyond about 12 MPa √m for these same specimens, the striation spacing decreased below 30 μ, the monolithic jumping dissolved into more continuous changes in signals, although the smaller striations were still visible on the fracture surface.

  6. High ramp rate thermogravimetric analysis of zirconium(II) hydride and titanium(II) hydride

    Energy Technology Data Exchange (ETDEWEB)

    Licavoli, Joseph J., E-mail: jjlicavo@mtu.edu; Sanders, Paul G., E-mail: sanders@mtu.edu

    2015-09-20

    Highlights: • A unique arc image device has been proposed for high ramp rate thermogravimetry. • Powder oxidation influences decomposition kinetics at temperatures below 933 K. • Particle size has a negligible effect on TiH{sub 2} decomposition behavior. • Improvements to the device are required to conduct accurate kinetic analysis. - Abstract: Zirconium and titanium hydride are utilized in liquid phase metal foam processing techniques. This application results in immediate exposure to molten metal and almost immediate decomposition at high temperatures. Most decomposition characterization techniques utilize slow heating rates and are unable to capture the decomposition behavior of hydrides under foam processing conditions. In order to address this issue a specialized high ramp rate thermogravimetric analyzer was created from a xenon arc image refiner. In addition to thermogravimetry, complimentary techniques including X-ray diffraction and scanning electron microscopy were used to characterize hydride decomposition and compare the results to literature. Hydrides were partially oxidized and separated into particles size ranges to evaluate the influence of these factors on decomposition. Oxidizing treatments were found to decrease decomposition rate only at temperatures below 933 K (660 °C) while particle size effects appeared to be negligible. Several improvements to the unique TGA apparatus presented in the current work are suggested to allow reliable kinetic modeling and analysis.

  7. ORNL Interim Progress Report on Hydride Reorientation CIRFT Tests

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yan, Yong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-28

    A systematic study of H. B. Robinson (HBR) high burnup spent nuclear fuel (SNF) vibration integrity was performed in Phase I project under simulated transportation environments, using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) hot cell testing technology developed at Oak Ridge National Laboratory in 2013–14. The data analysis on the as-irradiated HBR SNF rods demonstrated that the load amplitude is the dominant factor that controls the fatigue life of bending rods. However, previous studies have shown that the hydrogen content and hydride morphology has an important effect on zirconium alloy mechanical properties. To address the effect of radial hydrides in SNF rods, in Phase II a test procedure was developed to simulate the effects of elevated temperatures, pressures, and stresses during transfer-drying operations. Pressurized and sealed fuel segments were heated to the target temperature for a preset hold time and slow-cooled at a controlled rate. The procedure was applied to both non-irradiated/prehydrided and high-burnup Zircaloy-4 fueled cladding segments using the Nuclear Regulatory Commission-recommended 400°C maximum temperature limit at various cooling rates. Before testing high-burnup cladding, four out-of-cell tests were conducted to optimize the hydride reorientation (R) test condition with pre-hydride Zircaloy-4 cladding, which has the same geometry as the high burnup fuel samples. Test HR-HBR#1 was conducted at the maximum hoop stress of 145 MPa, at a 400°C maximum temperature and a 5°C/h cooling rate. On the other hand, thermal cycling was performed for tests HR-HBR#2, HR-HBR#3, and HR-HBR#4 to generate more radial hydrides. It is clear that thermal cycling increases the ratio of the radial hydride to circumferential hydrides. The internal pressure also has a significant effect on the radial hydride morphology. This report describes a procedure and experimental results of the four out-of-cell hydride reorientation tests of

  8. Growth and decomposition of Lithium and Lithium hydride on Nickel

    DEFF Research Database (Denmark)

    Engbæk, Jakob; Nielsen, Gunver; Nielsen, Jane Hvolbæk

    2006-01-01

    In this paper we have investigated the deposition, structure and decomposition of lithium and lithium-hydride films on a nickel substrate. Using surface sensitive techniques it was possible to quantify the deposited Li amount, and to optimize the deposition procedure for synthesizing lithium......-hydride films. By only making thin films of LiH it is possible to study the stability of these hydride layers and compare it directly with the stability of pure Li without having any transport phenomena or adsorbed oxygen to obscure the results. The desorption of metallic lithium takes place at a lower...... temperature than the decomposition of the lithium-hydride, confirming the high stability and sintering problems of lithium-hydride making the storage potential a challenge. (c) 2006 Elsevier B.V. All rights reserved....

  9. Helium trapping at erbium oxide precipitates in erbium hydride

    Energy Technology Data Exchange (ETDEWEB)

    Foiles, Stephen M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Battaile, Corbett Chandler [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-02-01

    The formation of He bubbles in erbium tritides is a significant process in the aging of these materials. Due to the long-standing uncertainty about the initial nucleation process of these bubbles, there is interest in mechanisms that can lead to the localization of He in erbium hydrides. Previous work has been unable to identify nucleation sites in homogeneous erbium hydride. This work builds on the experimental observation that erbium hydrides have nano- scale erbium oxide precipitates due to the high thermodynamic stability of erbium oxide and the ubiquitous presence of oxygen during materials processing. Fundamental DFT calculations indicate that the He is energetically favored in the oxide relative to the bulk hydride. Activation energies for the motion of He in the oxide and at the oxide-hydride interface indicate that trapping is kinetically feasible. A simple kinetic Monte Carlo model is developed that demonstrates the degree of trapping of He as a function of temperature and oxide fraction.

  10. Photochromism of rare-earth metal-oxy-hydrides

    Science.gov (United States)

    Nafezarefi, F.; Schreuders, H.; Dam, B.; Cornelius, S.

    2017-09-01

    Recently, thin films of yttrium oxy-hydride (YOxHy) were reported to show an unusual color-neutral photochromic effect promising for application in smart windows. Our present work demonstrates that also oxy-hydrides based on Gd, Dy, and Er have photochromic properties and crystal structures similar to YOxHy. Compared to YOxHy, the optical bandgaps of the lanthanide based oxy-hydrides are smaller while photochromic contrast and kinetics show large variation among different cations. Based on these findings, we propose that cation alloying is a viable pathway to tailor the photochromic properties of oxy-hydride materials. Furthermore, we predict that the oxy-hydrides of the other lanthanides are also potentially photochromic.

  11. Metal hydrides for concentrating solar thermal power energy storage

    Science.gov (United States)

    Sheppard, D. A.; Paskevicius, M.; Humphries, T. D.; Felderhoff, M.; Capurso, G.; Bellosta von Colbe, J.; Dornheim, M.; Klassen, T.; Ward, P. A.; Teprovich, J. A.; Corgnale, C.; Zidan, R.; Grant, D. M.; Buckley, C. E.

    2016-04-01

    The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room temperature and as high as 1100 °C. The potential of metal hydrides for thermal storage is explored, while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature TES are also addressed.

  12. Crack growth through the thickness of thin-sheet Hydrided Zircaloy-4

    Science.gov (United States)

    Raynaud, Patrick A. C.

    means of digital image processing, so as to understand the influence of the hydride microstructure on fracture toughness, at the various test temperatures. Crack growth occurred through a microstructure which varied within the thickness of the thin-sheet Zircaloy-4 such that the hydrogen concentration and the radial hydride content decreased with increasing distance from the hydride blister. At 25°C, the fracture toughness was sensitive to the changes in hydride microstructure, such that the toughness KJi decreased from 39 MPa√m to 24 MPa√m with increasing hydrogen content and increasing the fraction of radial hydrides. The hydride particles present in the Zircaloy-4 substrate fractured ahead of the crack tip, and crack growth occurred by linking the crack-tip with the next hydride-induced primary void ahead of it. Unstable crack growth was observed at 25°C prior to any stable crack growth in the specimens where the hydrogen content was the highest. At 375°C as well as in most cases at 300°C, the hydride particles were resistant to cracking and the resistance to crack-growth initiation was very high. As a result, for this bend test procedure, crack extension was solely due to crack-tip blunting instead of crack growth in all tests at 375°C and in most cases at 300°C. The lower bound for fracture toughness at these temperatures, the parameter KJPmax, had values of K JPmax˜54MPa√m at both 300°C and 375°C. For cases where stable crack growth occurred at 300°C, the fracture toughness was K Ji˜58MPa√m and the tearing modulus was twice as high as that at 25°C. It is believed that the failure of hydrided Zircaloy-4 thin-wall cladding can be predicted using fracture mechanics analyses when failure occurs by crack growth. This failure mechanism was observed to occur in all cases at 25°C and in some cases at 300°C. However, at more elevated temperatures, such as 375°C, failure will likely occur by a mechanism other than crack growth, possibly by an

  13. Results of NDE Technique Evaluation of Clad Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kunerth, Dennis C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report fulfills the M4 milestone, M4FT-14IN0805023, Results of NDE Technique Evaluation of Clad Hydrides, under Work Package Number FT-14IN080502. During service, zirconium alloy fuel cladding will degrade via corrosion/oxidation. Hydrogen, a byproduct of the oxidation process, will be absorbed into the cladding and eventually form hydrides due to low hydrogen solubility limits. The hydride phase is detrimental to the mechanical properties of the cladding and therefore it is important to be able to detect and characterize the presence of this constituent within the cladding. Presently, hydrides are evaluated using destructive examination. If nondestructive evaluation techniques can be used to detect and characterize the hydrides, the potential exists to significantly increase test sample coverage while reducing evaluation time and cost. To demonstrate the viability this approach, an initial evaluation of eddy current and ultrasonic techniques were performed to demonstrate the basic ability to these techniques to detect hydrides or their effects on the microstructure. Conventional continuous wave eddy current techniques were applied to zirconium based cladding test samples thermally processed with hydrogen gas to promote the absorption of hydrogen and subsequent formation of hydrides. The results of the evaluation demonstrate that eddy current inspection approaches have the potential to detect both the physical damage induced by hydrides, e.g. blisters and cracking, as well as the combined effects of absorbed hydrogen and hydride precipitates on the electrical properties of the zirconium alloy. Similarly, measurements of ultrasonic wave velocities indicate changes in the elastic properties resulting from the combined effects of absorbed hydrogen and hydride precipitates as well as changes in geometry in regions of severe degradation. However, for both approaches, the signal responses intended to make the desired measurement incorporate a number of contributing

  14. Nanoindentation measurements of the mechanical properties of zirconium matrix and hydrides in unirradiated pre-hydrided nuclear fuel cladding

    Science.gov (United States)

    Rico, A.; Martin-Rengel, M. A.; Ruiz-Hervias, J.; Rodriguez, J.; Gomez-Sanchez, F. J.

    2014-09-01

    It is well known that the mechanical properties of the nuclear fuel cladding may be affected by the presence of hydrides. The average mechanical properties of hydrided cladding have been extensively investigated from a macroscopic point of view. In addition, the mechanical and fracture properties of bulk hydride samples fabricated from zirconium plates have also been reported. In this paper, Young's modulus, hardness and yield stress are measured for each phase, namely zirconium hydrides and matrix, of pre-hydrided nuclear fuel cladding. To this end, nanoindentation tests were performed on ZIRLO samples in as-received state, on a hydride blister and in samples with 150 and 1200 ppm of hydrogen homogeneously distributed along the hoop direction of the cladding. The results show that the measured mechanical properties of the zirconium hydrides and ZIRLO matrix (Young's modulus, hardness and yield stress) are rather similar. From the experimental data, the hydride volume fraction in the cladding samples with 150 and 1200 ppm was estimated and the average mechanical properties were calculated by means of the rule of mixtures. These values were compared with those obtained from ring compression tests. Good agreement between the results obtained by both methods was found.

  15. Nanoindentation measurements of the mechanical properties of zirconium matrix and hydrides in unirradiated pre-hydrided nuclear fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Rico, A., E-mail: alvaro.rico@urjc.es [DIMME, Departamento de Tecnología Mecánica, Universidad Rey Juan Carlos, c/Tulipán s/n, E-28933 Móstoles, Madrid (Spain); Martin-Rengel, M.A., E-mail: mamartin@mater.upm.es [Departamento de Ciencia de los Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren SN, E-28040 Madrid (Spain); Ruiz-Hervias, J., E-mail: jesus.ruiz@upm.es [Departamento de Ciencia de los Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren SN, E-28040 Madrid (Spain); Rodriguez, J. [DIMME, Departamento de Tecnología Mecánica, Universidad Rey Juan Carlos, c/Tulipán s/n, E-28933 Móstoles, Madrid (Spain); Gomez-Sanchez, F.J., E-mail: javier.gomez@amsimulation.com [Advanced Material Simulation, S.L, Madrid (Spain)

    2014-09-15

    It is well known that the mechanical properties of the nuclear fuel cladding may be affected by the presence of hydrides. The average mechanical properties of hydrided cladding have been extensively investigated from a macroscopic point of view. In addition, the mechanical and fracture properties of bulk hydride samples fabricated from zirconium plates have also been reported. In this paper, Young’s modulus, hardness and yield stress are measured for each phase, namely zirconium hydrides and matrix, of pre-hydrided nuclear fuel cladding. To this end, nanoindentation tests were performed on ZIRLO samples in as-received state, on a hydride blister and in samples with 150 and 1200 ppm of hydrogen homogeneously distributed along the hoop direction of the cladding. The results show that the measured mechanical properties of the zirconium hydrides and ZIRLO matrix (Young’s modulus, hardness and yield stress) are rather similar. From the experimental data, the hydride volume fraction in the cladding samples with 150 and 1200 ppm was estimated and the average mechanical properties were calculated by means of the rule of mixtures. These values were compared with those obtained from ring compression tests. Good agreement between the results obtained by both methods was found.

  16. Nanostructured Magnesium Hydride for Reversible Hydrogen Storage

    Science.gov (United States)

    de Rango, P.; Chaise, A.; Fruchart, D.; Miraglia, S.; Marty, Ph.

    2013-05-01

    The aim of this work was to develop suitable materials to store hydrogen in a solid state. A systematic investigation of the co-milling process of magnesium hydride with a transition metal was undertaken in order to produce nanostructured and highly reactive powders. The initiating role of the transition metal was evidenced by in situ neutron diffraction experiments. High performances in terms of thermal and mechanical behavior were achieved introducing expanded graphite and compacting the mixture to form composite materials. Absorption and desorption kinetics have been measured versus temperature and H2 pressure.

  17. Lithium hydride - A space age shielding material

    Science.gov (United States)

    Welch, F. H.

    1974-01-01

    Men and materials performing in the environment of an operating nuclear reactor require shielding from the escaping neutron particles and gamma rays. For efficient shielding from gamma rays, dense, high atomic number elements such as iron, lead, or tungsten are required, whereas light, low atomic number elements such as hydrogen, lithium, or beryllium are required for efficient neutron shielding. The use of lithium hydride (LiH) as a highly efficient neutron-shielding material is considered. It contains, combined into a single, stable compound, two of the elements most effective in attenuating and absorbing neutrons.

  18. Highly Concentrated Palladium Hydrides/Deuterides; Theory

    Energy Technology Data Exchange (ETDEWEB)

    Papaconstantopoulos, Dimitrios

    2013-11-26

    Accomplishments are reported in these areas: tight-binding molecular dynamics study of palladium; First-principles calculations and tight-binding molecular dynamics simulations of the palladium-hydrogen system; tight-binding studies of bulk properties and hydrogen vacancies in KBH{sub 4}; tight-binding study of boron structures; development of angular dependent potentials for Pd-H; and density functional and tight-binding calculations for the light-hydrides NaAlH4 and NaBH4

  19. Development of nickel-metal hydride cell

    Science.gov (United States)

    Kuwajima, Saburo; Kamimori, Nolimits; Nakatani, Kensuke; Yano, Yoshiaki

    1993-01-01

    National Space Development Agency of Japan (NASDA) has conducted the research and development (R&D) of battery cells for space use. A new R&D program about a Nickel-Metal Hydride (Ni-MH) cell for space use from this year, based on good results in evaluations of commercial Ni-MH cells in Tsukuba Space Center (TKSC), was started. The results of those commercial Ni-MH cell's evaluations and recent status about the development of Ni-MH cells for space use are described.

  20. Binaurality and azimuth tun-ing of neurons in the auditorycortex of the big brown bat

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By using a combined closed and free-field stimulation system, binaurality and azimuth tuning of the neurons in the auditory cortex of the big brown bat, Eptesicus fuscus, were studied. A variety of azimuth-tuning functions were demonstrated for the binaural neurons. The large majority of EE (contralateral and ipsilateral excitatory) neurons exhibited azimuth selectivity with the best azimuths (BA) at contralateral 30(- 40(, some at ipsilateral 20(-40( and preferred azimuth ranges (PAR, response amplitude ≥75% of maximum) between 8( and 40(. Sound source azimuths strongly modulate spike counts with a mean modulation depth of 83.8% for EE neurons. EI (contralateral excitatory and ipsilateral inhibitory) neurons have simple azimuth tuning with BA located at contralateral 20(-40( and a broad PAR ranged from 30( to 55(. The present results suggest that azimuth-tuning characteristics of binaural neurons in the auditory cortex of the bat are of significance for acoustic behaviour.

  1. The method for analysing jet azimuthal anisotropy in ultrarelativistic heavy ion collisions

    CERN Document Server

    Lokhtin, Igor P; Snigirev, A M

    2002-01-01

    The azimuthal anisotropy of jet spectra due to energy loss of jet partons in azimuthally non-symmetric volume of dense quark-gluon matter is considered for semi-central nuclear interactions at collider energies. We develop the techniques for event-by-event analysing jet azimuthal anisotropy using particle and energy elliptic flow, and suggest the method for calculating coefficient of jet azimuthal anisotropy without reconstruction of nuclear reaction plane.

  2. Azimuthal anisotropies as stringent test for nuclear transport models

    Science.gov (United States)

    Crochet, P.; Rami, F.; Donà, R.; Coffin, J. P.; Fintz, P.; Guillaume, G.; Jundt, F.; Kuhn, C.; Roy, C.; de Schauenburg, B.; Tizniti, L.; Wagner, P.; Alard, J. P.; Andronic, A.; Basrak, Z.; Bastid, N.; Belyaev, I.; Bendarag, A.; Berek, G.; Best, D.; Biegansky, J.; Buta, A.; Čaplar, R.; Cindro, N.; Dupieux, P.; Dželalija, M.; Fan, Z. G.; Fodor, Z.; Fraysse, L.; Freifelder, R. P.; Gobbi, A.; Herrmann, N.; Hildenbrand, K. D.; Hong, B.; Jeong, S. C.; Kecskemeti, J.; Kirejczyk, M.; Koncz, P.; Korolija, M.; Kotte, R.; Lebedev, A.; Leifels, Y.; Manko, V.; Moisa, D.; Mösner, J.; Neubert, W.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Reisdorf, W.; Ritman, J. L.; Sadchikov, A. G.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczyńska, K.; Sodan, U.; Teh, K. M.; Trzaska, M.; Wang, G. S.; Wessels, J. P.; Wienold, T.; Wisniewski, K.; Wohlfarth, D.; Zhilin, A.; Hartnack, C.; FOPI Collaboration

    1997-02-01

    Azimuthal distributions of charged particles and intermediate mass fragments emitted in Au+Au collisions at 600 A MeV have been measured using the FOPI facility at GSI-Darmstadt. Data show a strong increase of the in-plane azimuthal anisotropy ratio with the charge of the detected fragment. Intermediate mass fragments are found to exhibit a strong momentum-space alignment with respect of the reaction plane. The experimental results are presented as a function of the polar centre-of-mass angle and over a broad range of impact parameters. They are compared to the predictions of the Isospin Quantum Molecular Dynamics model using three different parametrisations of the equation of state. We show that such highly accurate data provide stringent test for microscopic transport models and can potentially constrain separately the stiffness of the nuclear equation of state and the momentum dependence of the nuclear interaction.

  3. Initial state azimuthal anisotropies in small collision systems

    CERN Document Server

    Lappi, T

    2015-01-01

    Strong multiparticle azimuthal correlations have recently been observed in high energy proton-nucleus collisions. While final state collective effects can be responsible for many of the observations, the domain structure in the classical color field of a high energy nucleus also naturally leads to such correlations. We describe recent calculations of the momentum space 2-particle cumulant azimuthal anisotropy coefficients v_n{2}, n=2,3,4 from fundamental representation Wilson line distributions describing the high energy nucleus. We find significant differences between Wilson lines from the MV model and from JIMWLK evolution. We also discuss the relation of this calculation to earlier work on the ridge correlation obtained in the "glasma graph" approximation, and to the "color electric field domain model."

  4. Photoinduced Magnetic Nanoprobe Excited by Azimuthally Polarized Vector Beam

    CERN Document Server

    Guclu, Caner; Capolino, Filippo

    2016-01-01

    The concept of magnetic nanoprobes (or magnetic nanoantennas) providing a magnetic near-field enhancement and vanishing electric field is presented and investigated, together with their excitation. It is established that a particular type of cylindrical vector beams called azimuthally electric polarized vector beams yield strong longitudinal magnetic field on the beam axis where the electric field is ideally null. These beams with an electric polarization vortex and cylindrical symmetry are important in generating high magnetic to electric field contrast, i.e., large local field admittance, and in allowing selective excitation of magnetic transitions in matter located on the beam axis. We demonstrate that azimuthally polarized vector beam excitation of a photoinduced magnetic nanoprobe made of a magnetically polarizable nano cluster leads to enhanced magnetic near field with resolution beyond diffraction limit. We introduce two figures of merit as magnetic field enhancement and local field admittance normaliz...

  5. Azimuthal Decorrelation of Jets Widely Separated in Rapidity

    Science.gov (United States)

    Abachi, S.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alitti, J.; Álvarez, G.; Alves, G. A.; Amidi, E.; Amos, N.; Anderson, E. W.; Aronson, S. H.; Astur, R.; Avery, R. E.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Bartlett, J. F.; Bazizi, K.; Bendich, J.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Bischoff, A.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Borders, J.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; de, K.; Demarteau, M.; Denisenko, N.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Dixon, R.; Draper, P.; Drinkard, J.; Ducros, Y.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahey, S.; Fahland, T.; Fatyga, M.; Fatyga, M. K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Franzini, P.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Geld, T. L.; Genik, R. J., II; Genser, K.; Gerber, C. E.; Gibbard, B.; Glebov, V.; Glenn, S.; Glicenstein, J. F.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gómez, B.; Gomez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Griffin, G.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Gu, W. X.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Guryn, W.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hansen, S.; Hatcher, R.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Tao; Hu, Ting; Hu, Tong; Huehn, T.; Igarashi, S.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johari, H.; Johns, K.; Johnson, M.; Johnstad, H.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Kehoe, R.; Kelly, M. L.; Kerth, L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klochkov, B. I.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Landsberg, G.; Lebrat, J.-F.; Leflat, A.; Li, H.; Li, J.; Li, Y. K.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Mani, S.; Mao, H. S.; Margulies, S.; Markeloff, R.; Markosky, L.; Marshall, T.; Martin, M. I.; May, B.; Mayorov, A. A.; McCarthy, R.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; de Mello Neto, J. R.; Merritt, K. W.; Miettinen, H.; Mincer, A.; de Miranda, J. M.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Mudan, M.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Neis, E.; Nemethy, P.; NešiĆ, D.; Nicola, M.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Pang, M.; Para, A.; Park, C. H.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Perkins, J.; Peryshkin, A.; Peters, M.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Pušeljić, D.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rao, M. V.; Rapidis, P. A.; Rasmussen, L.; Read, A. L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Souza, M.; Spadafora, A. L.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stoianova, D. A.; Stoker, D.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Taylor, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Virador, P. R.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; Wen, F.; White, A.; White, J. T.; Wightman, J. A.; Wilcox, J.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Q.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1996-07-01

    This study reports the first measurement of the azimuthal decorrelation between jets with pseudorapidity separation up to five units. The data were accumulated using the D0 detector during the 1992-1993 collider run of the Fermilab Tevatron at s = 1.8 TeV. These results are compared to next-to-leading order (NLO) QCD predictions and to two leading-log approximations (LLA) where the leading-log terms are resummed to all orders in αS. The final state jets as predicted by NLO QCD show less azimuthal decorrelation than the data. The parton showering LLA Monte Carlo HERWIG describes the data well; an analytical LLA prediction based on Balitsky-Fadin-Kuraev-Lipatov resummation shows more decorrelation than the data.

  6. Conformal couplings and "azimuthal matching" of QCD Pomerons

    CERN Document Server

    Marchal, N

    2000-01-01

    Using the asymptotic conformal invariance of perturbative QCD we derive the expression of the coupling of external states to all conformal spin-p components of the forward elastic amplitude. Using the wave-function formalism for structure functions at small x, we derive the perturbative coupling of the virtual photon for p= 1, which is maximal for linear transverse polarization. The non-perturbative coupling to the proton is discussed in terms of ``azimuthal matching'' between the proton color dipoles and the quark- antiquark configurations of the photon. As an application, the recent conjecture of a second QCD Pomeron related to the conformal spin-1 component is shown to rely upon a strong azimuthal matching of the p= 1 component in gamma* -proton scattering.

  7. The azimuthal decorrelation of jets widely separated in rapidity

    CERN Document Server

    Abachi, S; Abolins, M; Acharya, B S; Adam, I; Adams, D L; Adams, M; Ahn, S; Aihara, H; Alitti, J; Alvarez, G; Alves, G A; Amidi, E; Amos, N; Anderson, E W; Aronson, S H; Astur, R; Avery, R E; Baden, A; Balamurali, V; Balderston, J; Baldin, B Yu; Bantly, J; Bartlett, J F; Bazizi, K; Bendich, J; Beri, S B; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Bischoff, A; Biswas, N; Blazey, G C; Blessing, S K; Bloom, P; Böhnlein, A; Bozhko, N; Borcherding, F O; Borders, J; Boswell, C; Brandt, A; Brock, R L; Bross, A D; Buchholz, D A; Burtovoi, V S; Butler, J M; Casey, D; Castilla-Valdez, H; Chakraborty, D; Chang, S M; Chekulaev, S V; Chen, L P; Chen, W; Chevalier, L; Chopra, S; Choudhary, B C; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cobau, W G; Cochran, J; Cooper, W E; Cretsinger, C E; Cullen-Vidal, D E; Cummings, M; Cutts, D; Dahl, O I; De, K; Demarteau, M; Demina, R; Denisenko, K; Denisenko, N; Denisov, D S; Denisov, S P; Dharmaratna, W; Diehl, H T; Diesburg, M; DiLoreto, G; Dixon, R; Draper, P; Drinkard, J; Ducros, Y; Dugad, S R; Durston-Johnson, S; Edmunds, D L; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Evdokimov, V N; Fahey, S; Fahland, T; Fatyga, M K; Featherly, J; Fehér, S; Fein, D K; Ferbel, T; Finocchiaro, G; Fisk, H E; Fisyak, Yu; Flattum, E M; Forden, G E; Fortner, M R; Frame, K C; Franzini, P; Fredriksen, S; Fuess, S; Galjaev, A N; Gallas, E J; Gao, C S; Gao, S; Geld, T L; Genik, R J; Genser, K; Gerber, C E; Gibbard, B; Glebov, V Yu; Glenn, S; Gobbi, B; Glicenstein, J F; Goforth, M; Goldschmidt, A; Gómez, B; Good, M L; Goncharov, P I; Gordon, H; Goss, L T; Graf, N; Grannis, P D; Green, D R; Green, J; Greenlee, H B; Griffin, G; Grossman, N L; Grudberg, P M; Grünendahl, S; Gu, W; Guida, J A; Guida, J M; Guryn, W; Gurzhev, S N; Gutnikov, Yu E; Hadley, N J; Haggerty, H; Hagopian, S L; Hagopian, V; Hahn, K S; Hall, R; Hansen, S; Hatcher, R; Hauptman, J M; Hedin, D; Heinson, A P; Heintz, U; Hernández-Montoya, R; Heuring, T C; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoftun, J S; Hsieh, F; Ting, H; Hu Tong; Hühn, T; Igarashi, S; Ito, A S; James, E; Jaques, J; Jerger, S A; Jiang, J Z Y; Joffe-Minor, T M; Johari, H; Johns, K; Johnson, M; Johnstad, H; Jonckheere, A M; Jones, M; Jöstlein, H; Jun, S Y; Jung, C K; Kahn, S; Kang, J S; Kehoe, R; Kelly, M; Kernan, A; Kerth, L T; Kim, C L; Klatchko, A; Klima, B; Klochkov, B I; Klopfenstein, C; Klioukhine, V I; Kochetkov, V I; Kohli, J M; Koltick, D S; Kotcher, J; Kostritskii, A V; Kourlas, J; Kozelov, A V; Kozlovskii, E; Krishnaswamy, M R; Krzywdzinski, S; Kunori, S; Lami, S; Landsberg, G L; Lanou, R E; Lebrat, J F; Leflat, A; Li, H; Li, J; Li, R B; Li, Y K; Li-Demarteau, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J T; Lipton, R; Liu, Y C; Lobkowicz, F; Loch, P; Loken, S C; Lökös, S; Lueking, L H; Lyon, A L; Maciel, A K A; Madaras, R J; Madden, R; Mandrichenko, I V; Mangeot, Philippe; Mani, S; Mansoulié, B; Mao, H S; Margulies, S; Markeloff, R; Markosky, L A; Marshall, T; Martin, M I; Marx, M; May, B; Mayorov, A A; McCarthy, R; McKibbens, T; McKinley, J; Melanson, H L; De Mello-Neto, J R T; Merritt, K W B; Miettinen, H; Milder, A J; Mincer, A; De Miranda, J M; Mishra, C S; Mohammadi-Baarmand, M; Mokhov, N V; Mondal, N K; Montgomery, H E; Mooney, P; Mudan, M S; Murphy, C; Murphy, C T; Nang, F; Narain, M; Narasimham, V S; Narayanan, A; Neal, H A; Negret, J P; Neis, E; Némethy, P; Nesic, D; Norman, D; Oesch, L H; Oguri, V; Oltman, E; Oshima, N; Owen, D; Padley, P; Pang, M; Para, A; Park, C H; Partridge, R; Parua, N; Paterno, M; Perkins, J; Peryshkin, A N; Peters, M; Piekarz, H; Pishchalnikov, Yu M; Pluquet, A; Podstavkov, V M; Pope, B G; Prosper, H B; Protopopescu, S D; Puseljic, D; Qian, J; Quintas, P Z; Raja, R; Rajagopalan, S; Ramírez, O; Rao, M V S; Rapidis, P A; Rasmussen, L; Read, A L; Reucroft, S; Rijssenbeek, M; Rockwell, T; Roe, N A; Rubinov, P M; Ruchti, R C; Rusi, S; Rutherfoord, John P; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Scully, J R; Shabbalina, E; Shaffer, C; Shankar, H C; Shivpuri, R K; Shupe, M A; Singh, J B; Sirotenko, V I; Smart, W M; Smith, A; Smith, R P; Snihur, R; Snow, G A; Snyder, S; Solomon, J; Sood, P M; Sosebee, M; Souza, M; Spadafora, A L; Stephens, R W; Stevenson, M L; Stewart, D; Stocker, F; Stoyanova, D A; Stoker, D P; Streets, K; Strovink, M; Taketani, A; Tamburello, P D; Tarazi, J; Tartaglia, M; Taylor, T L; Teiger, J; Thompson, J; Trippe, T G; Tuts, P M; Varelas, N; Varnes, E W; Virador, P; Vititoe, D L; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, D C; Wang, L Z; Warchol, J; Wayne, M; Weerts, H; Wenzel, W A; White, A; White, J T; Wightman, J A; Wilcox, J; Willis, S; Wimpenny, S J; Wirjawan, J V D; Womersley, J; Won, E; Wood, D R; Xu, H; Yamada, R; Yamin, P; Yanagisawa, C; Yang, J; Yang, M J; Yasuda, T; Yoshikawa, C; Youssef, S; Yu, J; Yu, Y; Zhang, Y; Zhang, Z; Zhou, Y H; Zhu, Q; Zhu, Y S; Zhu, Z H; Zieminska, D; Zieminski, A; Zylberstejn, A

    1996-01-01

    This study reports the first measurement of the azimuthal decorrelation between jets with pseudorapidity separation up to five units. The data were accumulated using the D\\O\\ detector during the 1992--1993 collider run of the Fermilab Tevatron at \\sqrt{s}= 1.8 TeV. These results are compared to next--to--leading order (NLO) QCD predictions and to two leading--log approximations (LLA) where the leading--log terms are resummed to all orders in \\alpha_{\\scriptscriptstyle S}. The final state jets as predicted by NLO QCD show less azimuthal decorrelation than the data. The parton showering LLA Monte Carlo {\\small HERWIG} describes the data well; an analytical LLA prediction based on BFKL resummation shows more decorrelation than the data.

  8. Theoretical Aspects of Azimuthal and Transverse Spin Asymmetries

    CERN Document Server

    Mulders, P J; Boer, D

    2001-01-01

    We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading (zeroth) order in a 1/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins fragmentation function. The moments of these functions are matrix elements of known twist two and twist three operators. We present the evolution in the large N_c limit, restricted to the non-singlet case for the chiral-even functions.

  9. THEORETICAL ASPECTS OF AZIMUTHAL AND TRANSVERSE SPIN ASYMMETRIES.

    Energy Technology Data Exchange (ETDEWEB)

    MULDERS,P.J.; HENNEMAN,A.A.; BOER,D.

    2001-04-27

    We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading (zeroth) order in a l/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins fragmentation function. The moments of these functions are matrix elements of known twist two and twist three operators. We present the evolution in the large NC limit, restricted to the non-singlet case for the chiral-even functions.

  10. Theoretical Aspects of Azimuthal and Transverse Spin Asymmetries

    Science.gov (United States)

    Mulders, P. J.; Henneman, A. A.; Boer, D.

    2002-10-01

    We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading (zeroth) order in a 1/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins fragmentation function. The moments of these functions are matrix elements of known twist two and twist three operators. We present the evolution in the large Nc limit, restricted to the non-singlet case for the chiral-even functions.

  11. Propagation along azimuthally magnetized ferrite-loaded circular waveguides

    Science.gov (United States)

    Mueller, R. S.; Rosenbaum, F. J.

    1977-01-01

    The paper describes the modal dispersion characteristics of electromagnetic waves traveling along the azimuthally magnetized ferrite-loaded coaxial transmission line and the ferrite-loaded wire. The modal dispersion curves are used to determine the pass and stop bands of normal propagation. Boundary-value problems were solved with Bolle-Heller functions. The dispersion characteristics of transverse electric modes are presented as plots of the normalized propagation constant vs the normalized frequency.

  12. Measurement of Azimuthal Asymmetries in Deep Inelastic Scattering

    CERN Document Server

    Breitweg, J; Derrick, Malcolm; Krakauer, D A; Magill, S; Musgrave, B; Pellegrino, A; Repond, J; Stanek, R; Yoshida, R; Mattingly, M C K; Abbiendi, G; Anselmo, F; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Castellini, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Coppola, N; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Laurenti, G; Levi, G; Margotti, A; Massam, Thomas; Nania, R; Palmonari, F; Pesci, A; Polini, A; Sartorelli, G; Zamora-Garcia, Yu E; Zichichi, A; Amelung, C; Bornheim, A; Brock, I; Coboken, K; Crittenden, James Arthur; Deffner, R; Hartmann, H; Heinloth, K; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kerger, R; Paul, E; Schnurbusch, H; Stifutkin, A; Tandler, J; Voss, K C; Weber, A; Wieber, H; Bailey, D S; Barret, O; Brook, N H; Foster, B; Heath, G P; Heath, H F; McFall, J D; Piccioni, D; Rodrigues, E; Scott, J; Tapper, R J; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Jeoung, H Y; Kim, J Y; Lee, J H; Lim, I T; Ma, K J; Pac, M Y; Caldwell, A; Liu, W; Liu, X; Mellado, B; Paganis, S; Sampson, S; Schmidke, W B; Sciulli, F; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Klimek, K H; Olkiewicz, K; Piotrzkowski, K; Przybycien, M B; Stopa, P; Zawiejski, L; Bednarek, B; Jelen, K; Kisielewska, D; Kowal, A M; Kowalski, T; Rulikowska-Zarebska, E; Suszycki, L; Szuba, D; Kotanski, Andrzej; Bauerdick, L A T; Behrens, U; Bienlein, J K; Burgard, C; Dannheim, D; Desler, K; Drews, G; Fox-Murphy, A; Fricke, U; Göbel, F; Göttlicher, P; Graciani, R; Haas, T; Hain, W; Hartner, G F; Hasell, D; Hebbel, K; Johnson, K F; Kasemann, M; Koch, W; Kötz, U; Kowalski, H; Lindemann, L; Löhr, B; Martínez, M; Milite, M; Monteiro, T; Moritz, M; Notz, D; Pelucchi, F; Petrucci, M C; Rohde, M; Saull, P R B; Savin, A A; Schneekloth, U; Selonke, F; Sievers, M; Stonjek, S; Tassi, E; Wolf, G; Wollmer, U; Youngman, C; Zeuner, W; Coldewey, C; López-Duran-Viani, A; Meyer, A; Schlenstedt, S; Straub, P B; Barbagli, G; Gallo, E; Pelfer, P G; Maccarrone, G D; Votano, L; Bamberger, Andreas; Benen, A; Eisenhardt, S; Markun, P; Raach, H; Wölfle, S; Bussey, Peter J; Doyle, A T; Lee, S W; MacDonald, N; McCance, G J; Saxon, D H; Sinclair, L E; Skillicorn, Ian O; Waugh, R; Bohnet, I; Gendner, N; Holm, U; Meyer-Larsen, A; Salehi, H; Wick, K; Garfagnini, A; Gialas, I; Gladilin, L K; Kcira, D; Klanner, Robert; Lohrmann, E; Poelz, G; Zetsche, F; Goncalo, R; Long, K R; Miller, D B; Tapper, A D; Walker, R; Mallik, U; Cloth, P; Filges, D; Ishii, T; Kuze, M; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Ahn, S H; Lee, S B; Park, S K; Lim, H; Park, I H; Son, D; Barreiro, F; García, G; Glasman, C; González, O; Labarga, L; Del Peso, J; Redondo, I; Terron, J; Barbi, M S; Corriveau, F; Hanna, D S; Ochs, A; Padhi, S; Riveline, M; Stairs, D G; Wing, M; Tsurugai, T; Bashkirov, V; Dolgoshein, B A; Dementev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korotkova, N A; Korzhavina, I A; Kuzmin, V A; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Solomin, A N; Vlasov, N N; Zotkin, S A; Bokel, C; Botje, M; Brümmer, N; Engelen, J; Grijpink, S; Koffeman, E; Kooijman, P M; Schagen, S; Van Sighem, A; Tiecke, H G; Tuning, N; Velthuis, J J; Vossebeld, Joost Herman; Wiggers, L; De Wolf, E; Acosta, D; Bylsma, B; Durkin, L S; Gilmore, J; Ginsburg, C M; Kim, C L; Ling, T Y; Boogert, S; Cooper-Sarkar, A M; Devenish, R C E; Grosse-Knetter, J; Matsushita, T; Ruske, O; Sutton, M R; Walczak, R; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; Dosselli, U; Dusini, S; Limentani, S; Morandin, M; Posocco, M; Stanco, L; Stroili, R; Voci, C; Adamczyk, L; Iannotti, L; Oh, B Y; Okrasinski, J R; Toothacker, W S; Whitmore, J J; Iga, Y; D'Agostini, Giulio; Marini, G; Nigro, A; Cormack, C; Hart, J C; McCubbin, N A; Shah, T P; Epperson, D E; Heusch, C A; Sadrozinski, H F W; Seiden, A; Wichmann, R; Williams, D C; Pavel, N; Abramowicz, H; Dagan, S; Kananov, S; Kreisel, A; Levy, A; Abe, T; Fusayasu, T; Umemori, K; Yamashita, T; Hamatsu, R; Hirose, T; Inuzuka, M; Kitamura, S; Nishimura, T; Arneodo, M; Cartiglia, N; Cirio, R; Costa, M; Ferrero, M I; Maselli, S; Monaco, V; Peroni, C; Ruspa, M; Sacchi, R; Solano, A; Staiano, A; Dardo, M; Bailey, D C; Fagerstroem, C P; Galea, R; Koop, T; Levman, G M; Martin, J F; Orr, R S; Polenz, S; Sabetfakhri, A; Simmons, D; Butterworth, J M; Catterall, C D; Hayes, M E; Heaphy, E A; Jones, T W; Lane, J B; West, B J; Ciborowski, J; Ciesielski, R; Grzelak, G; Nowak, R J; Pawlak, J M; Pawlak, R; Smalska, B; Tymieniecka, T; Wróblewski, A K; Zakrzewski, J A; Adamus, M; Gadaj, T; Deppe, O; Eisenberg, Y; Hochman, D; Karshon, U; Badgett, W F; Chapin, D; Cross, R; Foudas, C; Mattingly, S E K; Reeder, D D; Smith, W H; Vaiciulis, A W; Wildschek, T; Wodarczyk, M; Deshpande, A A; Dhawan, S K; Hughes, V W; Bhadra, S; Cole, J E; Frisken, W R; Hall-Wilton, R; Khakzad, M; Menary, S R

    2000-01-01

    The distribution of the azimuthal angle for the charged hadrons has been studied in the hadronic centre-of-mass system for neutral current deep inelastic positron-proton scattering with the ZEUS detector at HERA. Measurements of the dependence of the moments of this distribution on the transverse momenta of the charged hadrons are presented. Asymmetries that can be unambiguously attributed to perturbative QCD processes have been observed for the first time.

  13. Moving Target Focusing with Normalized Relative Speed in Azimuth-Invarian Bistatic Sar

    OpenAIRE

    Vu, Viet Thuy; Sjögren, Thomas; Pettersson, Mats

    2013-01-01

    Focusing moving targets with Normalized Relative Speed (NRS) for bistatic synthetic aperture radar (SAR) is discussed in this paper. The discussion concentrates on azimuth invariant bistatic geometry. The focusing approach for azimuth-invariant bistatic geometry is derived analytically. The validity of the proposed approach for other bistatic geometry like azimuth-variant is also investigated.

  14. Rossby Wave Green's Functions in an Azimuthal Wind

    CERN Document Server

    Webb, G M; Hu, Q

    2015-01-01

    Green's functions for Rossby waves in an azimuthal wind are obtained, in which the stream-function $\\psi$ depends on $r$, $\\phi$ and $t$, where $r$ is cylindrical radius and $\\phi$ is the azimuthal angle in the $\\beta$-plane relative to the easterly direction, in which the $x$-axis points east and the $y$-axis points north. The Rossby wave Green's function with no wind is obtained using Fourier transform methods, and is related to the previously known Green's function obtained for this case, which has a different but equivalent form to the Green's function obtained in the present paper. We emphasize the role of the wave eikonal solution, which plays an important role in the form of the solution. The corresponding Green's function for a rotating wind with azimuthal wind velocity ${\\bf u}=\\Omega r{\\bf e}_\\phi$ ($\\Omega=$const.) is also obtained by Fourier methods, in which the advective rotation operator in position space is transformed to a rotation operator in ${\\bf k}$ transform space. The finite Rossby defo...

  15. Azimuth DOA Estimation in Y-bend Antenna Array

    Science.gov (United States)

    Sanudin, R.

    2016-11-01

    In smart antenna system, it is extremely crucial to estimate the direction of incoming signals in order to achieve better reception. Reliability of DOA estimation depends on several factors such as the choice of DOA algorithm, size of antenna array as well as array geometry. Therefore, it is particularly desirable to have a configuration of antenna array that could produce an accurate azimuth estimation. In this work, a new planar array is proposed to address the problem of azimuth estimation. This is achieved by having a flexible element position on the x- y plane that improves the steering vector, hence significantly enhances the accuracy of DOA estimation. Besides, a fair distribution of the antenna elements on the x-y plane also helps to eliminates estimation failure in the azimuth range between 240° and 360°. A comparison study between the proposed array and V-shape array is performed in order to gauge the performance of the proposed array in DOA estimation. Simulation results show that the proposed array has acquired better estimation resolution than V-shape array. On top of that, the proposed array has reduced estimation error in V-shape array. It is concluded that the proposed array has shown potential as an excellent choice of antenna array geometry for smart antenna system.

  16. Transverse Spin Azimuthal Asymmetries in SIDIS at COMPASS: Multidimensional Analysis

    Science.gov (United States)

    Parsamyan, Bakur

    2016-02-01

    COMPASS is a high-energy physics experiment operating at the SPS at CERN. Wide physics program of the experiment comprises study of hadron structure and spectroscopy with high energy muon and hadrons beams. As for the muon-program, one of the important objectives of the COMPASS experiment is the exploration of the transverse spin structure of the nucleon via spin (in)dependent azimuthal asymmetries in single-hadron production in deep inelastic scattering of polarized leptons off transversely polarized target. For this purpose a series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and transversely polarized 6LiD (in 2002, 2003 and 2004) and NH3 (in 2007 and 2010) targets. The experimental results obtained by COMPASS for unpolarized target azimuthal asymmetries, Sivers and Collins effects and other azimuthal observables play an important role in the general understanding of the three-dimensional nature of the nucleon. Giving access to the entire twsit-2 set of transverse momentum dependent parton distribution functions and fragmentation functions COMPASS data triggers constant theoretical interest and is being widely used in phenomenological analyses and global data fits. In this review main focus is given to the very recent results obtained by the COMPASS collaboration from first ever multi-dimensional extraction of transverse spin asymmetries.

  17. Transverse spin azimuthal asymmetries in SIDIS at COMPASS: Multidimensional analysis

    CERN Document Server

    Parsamyan, Bakur

    2015-01-01

    COMPASS is a high-energy physics experiment operating at the SPS at CERN. Wide physics program of the experiment comprises study of hadron structure and spectroscopy with high energy muon and hadrons beams. As for the muon-program, one of the important objectives of the COMPASS experiment is the exploration of the transverse spin structure of the nucleon via spin (in)dependent azimuthal asymmetries in single-hadron production in deep inelastic scattering of polarized leptons off transversely polarized target. For this purpose a series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and transversely polarized 6LiD (in 2002, 2003 and 2004) and NH3 (in 2007 and 2010) targets. The experimental results obtained by COMPASS for unpolarized target azimuthal asymmetries, Sivers and Collins effects and other azimuthal observables play an important role in the general understanding of the three-dimensional nature of the nucleon. Giving access to the entire "twsit-2" set of transv...

  18. Rossby wave Green's functions in an azimuthal wind

    Science.gov (United States)

    Webb, G. M.; Duba, C. T.; Hu, Q.

    2016-05-01

    Green's functions for Rossby waves in an azimuthal wind are obtained, in which the stream-function $\\psi$ depends on $r$, $\\phi$ and $t$, where $r$ is cylindrical radius and $\\phi$ is the azimuthal angle in the $\\beta$-plane relative to the easterly direction, in which the $x$-axis points east and the $y$-axis points north. The Rossby wave Green's function with no wind is obtained using Fourier transform methods, and is related to the previously known Green's function obtained for this case, which has a different but equivalent form to the Green's function obtained in the present paper. We emphasize the role of the wave eikonal solution, which plays an important role in the form of the solution. The corresponding Green's function for a rotating wind with azimuthal wind velocity ${\\bf u}=\\Omega r{\\bf e}_\\phi$ ($\\Omega=$const.) is also obtained by Fourier methods, in which the advective rotation operator in position space is transformed to a rotation operator in ${\\bf k}$ transform space. The finite Rossby deformation radius is included in the analysis. The physical characteristics of the Green's functions are delineated and applications are discussed. In the limit as $\\Omega\\to 0$, the rotating wind Green's function reduces to the Rossby wave Green function with no wind.

  19. GMT azimuth bogie wheel-rail interface wear study

    Science.gov (United States)

    Teran, Jose; Lindh, Cory; Morgan, Chris; Manuel, Eric; Bigelow, Bruce C.; Burgett, William S.

    2016-07-01

    Performance of the GMT azimuth drive system is vital for the operation of the telescope and, as such, all components subject to wear at the drive interface merit a high level of scrutiny for achieving a proper balance between capital costs, maintenance costs, and the risk for downtime during planned and unplanned maintenance or replacement procedures. Of particular importance is the interface between the azimuth wheels and rail, as usage frequency is high, the full weight of the enclosure must be transferred through small patches of contact, and replacement of the rail would pose a greater logistical challenge than the replacement of smaller components such as bearings and gearmotors. This study investigates tradeoffs between various wheel-rail and roller-track interfaces, including performance, complexity, and anticipated wear considerations. First, a survey of railway and overhead crane industry literature is performed and general detailing recommendations are made to minimize wear and the risk of rolling contact fatigue. Second, Adams/VI-Rail is used to simulate lifetime wear of four specific configurations under consideration for the GMT azimuth wheel-rail interface; all studied configurations are shown to be viable, and their relative merits are discussed.

  20. NATO Advanced Study Institute on Metal Hydrides

    CERN Document Server

    1981-01-01

    In the last five years, the study of metal hydrides has ex­ panded enormously due to the potential technological importance of this class of materials in hydrogen based energy conversion schemes. The scope of this activity has been worldwide among the industrially advanced nations. There has been a consensus among researchers in both fundamental and applied areas that a more basic understanding of the properties of metal/hydrogen syster;,s is required in order to provide a rational basis for the selection of materials for specific applications. The current worldwide need for and interest in research in metal hydrides indicated the timeliness of an Advanced Study Insti­ tute to provide an in-depth view of the field for those active in its various aspects. The inclusion of speakers from non-NATO coun­ tries provided the opportunity for cross-fertilization of ideas for future research. While the emphasis of the Institute was on basic properties, there was a conscious effort to stimulate interest in the applic...

  1. From permanent magnets to rechargeable hydride electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Willems, J.J.G.; Buschow, K.H.J.

    1987-02-15

    A brief historical survey is given of how the study of coercitivity mechanisms in SmCo/sub 5/ permanent-magnet materials eventually led to the discovery of the favourable hydrogen sorption properties of the compound LaNi/sub 5/. It is shown how continued research by many investigators dealing with a variety of different physical and chemical properties has resulted in an advanced understanding of some of the principles that govern hydrogen absorption and which are responsible for the changes in physical properties that accompany it. The problems associated with various applications of LaNi/sub 5/-based hydrogen-storage materials are also briefly discussed. A large part of this paper is devoted to the applicability of LaNi/sub 5/-type materials in batteries. Research in this area has resulted in the development of a new type of rechargeable battery: the nickel-hydride cell. This battery can be charged and discharged at high rates and is relatively insensitive to overcharging and overdischarging. Special attention is given to the nature of the electrode degradation process and the effect of composition variations in LaNi/sub 5/-related materials on the lifetime of the corresponding hydride electrodes when subjected to severe electrochemical charge-discharge cycles.

  2. Metal hydrides for lithium-ion batteries.

    Science.gov (United States)

    Oumellal, Y; Rougier, A; Nazri, G A; Tarascon, J-M; Aymard, L

    2008-11-01

    Classical electrodes for Li-ion technology operate via an insertion/de-insertion process. Recently, conversion electrodes have shown the capability of greater capacity, but have so far suffered from a marked hysteresis in voltage between charge and discharge, leading to poor energy efficiency and voltages. Here, we present the electrochemical reactivity of MgH(2) with Li that constitutes the first use of a metal-hydride electrode for Li-ion batteries. The MgH(2) electrode shows a large, reversible capacity of 1,480 mAh g(-1) at an average voltage of 0.5 V versus Li(+)/Li(o) which is suitable for the negative electrode. In addition, it shows the lowest polarization for conversion electrodes. The electrochemical reaction results in formation of a composite containing Mg embedded in a LiH matrix, which on charging converts back to MgH(2). Furthermore, the reaction is not specific to MgH(2), as other metal or intermetallic hydrides show similar reactivity towards Li. Equally promising, the reaction produces nanosized Mg and MgH(2), which show enhanced hydrogen sorption/desorption kinetics. We hope that such findings can pave the way for designing nanoscale active metal elements with applications in hydrogen storage and lithium-ion batteries.

  3. Molecular rare-earth-metal hydrides in non-cyclopentadienyl environments.

    Science.gov (United States)

    Fegler, Waldemar; Venugopal, Ajay; Kramer, Mathias; Okuda, Jun

    2015-02-02

    Molecular hydrides of the rare-earth metals play an important role as homogeneous catalysts and as counterparts of solid-state interstitial hydrides. Structurally well-characterized non-metallocene-type hydride complexes allow the study of elementary reactions that occur at rare-earth-metal centers and of catalytic reactions involving bonds between rare-earth metals and hydrides. In addition to neutral hydrides, cationic derivatives have now become available.

  4. Measurement of multi-directional azimuth and tilt angles using an improved DVD pickup head with a CMOS sensor: A simulation design study

    Science.gov (United States)

    Sun, Wen-Shing; Lin, Yan-Nan; Tien, Chuen-Lin; Chang, Jenq-Yang

    2013-06-01

    We present a new detection method for an improved DVD pickup head system capable of measuring the multidirectional azimuth and small tilt angles. A complementary metal-oxide semiconductor (CMOS) sensor is used to capture images and analyze the slight shift of the central position of the beam shape when the test plane rotates to create a tilt angle and angular signal. The proposed detection method can determine the azimuth angle of the test plane from 0° to 360° at intervals of 5°. The tilt angle measurement is varied from 0° to 4.2° at intervals of 0.3°. The simulation results show that the improved DVD pickup head system can recognize multi-directional azimuth angles of the test plane under a small tilt.

  5. Filiform-mode hydride corrosion of uranium surfaces

    Science.gov (United States)

    Hill, M. A.; Schulze, R. K.; Bingert, J. F.; Field, R. D.; McCabe, R. J.; Papin, P. A.

    2013-11-01

    Hydride nucleation and growth has previously been studied in uranium with an air-formed oxide. Preferred directional growth of uranium hydride has not been observed, presumably due to the constraint of the oxide layer and/or the presence of a surface layer distorted by mechanical grinding and polishing. Instead, hydrides typically first form as subsurface blisters that do not exhibit preferred growth directionality. By eliminating the strained surface layer through electropolishing, removing the natural oxide through ion sputtering, avoiding exposure of the uranium to air, and then exposing uranium to high purity hydrogen in an environmental cell, hydride growth patterns emerge that correspond to defect structures within the microstructure. These hydride growth patterns are similar to filiform corrosion, a type of corrosion that frequently forms under thin protective films. This work describes the first reported observation of filiform-like corrosion in uranium. The uranium hydride initiates at defects, but grows into filaments up to 20 μm wide, and tends to form in straight lines, largely propagating along twin boundaries. Propagation is driven by hydrogen reaction at the filament head, promoted by more efficient delivery of reactant. However, this phenomenon does not involve an electrochemical process associated with conventional filiform corrosion and is therefore described as filiform-like. Hydride growth was observed using optical microscopy for a period of nearly three years. Sample characterization included automated electron backscatter diffraction (EBSD) measurements to determine growth directions. Observation of this anomalous hydride growth provides clues as to the mechanisms operating in uranium hydriding for more conventionally prepared sample surfaces.

  6. Technical and economic aspects of hydrogen storage in metal hydrides

    Science.gov (United States)

    Schmitt, R.

    1981-01-01

    The recovery of hydrogen from such metal hydrides as LiH, MgH2, TiH2, CaH2 and FeTiH compounds is studied, with the aim of evaluating the viability of the technique for the storage of hydrogen fuel. The pressure-temperature dependence of the reactions, enthalpies of formation, the kinetics of the hydrogen absorption and desorption, and the mechanical and chemical stability of the metal hydrides are taken into account in the evaluation. Economic aspects are considered. Development of portable metal hydride hydrogen storage reservoirs is also mentioned.

  7. PIE techniques for hydride reorientation test at NDC

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, Tomohiro; Shinohara, Yasunari; Yamaguchi, Yoichiro [Nuclear Development Corporation, Ibaraki (Japan)

    2008-11-15

    Dry storage of spent fuels in the interim storage facility is being planned in Japan. However, the gradual deterioration of the mechanical property of fuel cladding due to internal pressure and temperature during the storage term is known. Therefore, the integrity of stored fuel rods should be confirmed before the start of dry storage. For the last several years, NDC had a lot of experiences on the hydride reorientation test. The specimen preparation techniques on the hydride reorientation test and the mechanical testing techniques after the hydride reorientation are shown in this paper.

  8. Hydrogen storage in metal hydrides and complex hydrides; Wasserstoffspeicherung in Metall- und komplexen Hydriden - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bielmann, M.; Zuettel, A.

    2007-07-01

    This final report for the Swiss Federal Office of Energy (SFOE), reports on work done in 2007 at the Swiss Federal Laboratories for Materials Science and Technology EMPA on the storage of hydrogen in metal hydrides and complex hydrides. In particular, the use of tetrahydroborates is noted. The potential of this class of materials is stressed. The structures at room-temperature were examined using neutron and X-ray diffraction methods. Thermodynamic methods helped determine the thermodynamic stability of the materials. Also, a complete energy diagram for the materials was developed. The use of silicon oxide to reduce activation energy and its catalytic effects are discussed. The challenges placed by desorption mechanisms are noted. The authors note that reversibility is basically proven.

  9. Azimuth calculation for buried pipelines using a synthetic array of emitters, a single survey line and scattering matrix formalism

    Science.gov (United States)

    Bullo, Darío; Villela, Almendra; Bonomo, Néstor

    2016-11-01

    We evaluate the simultaneous application of a synthetic-emitter array (SEA) methodology and formulation derived from the analysis of the rotation transformations of the scattering matrix (RTSM) to calculate the orientation of buried pipes from GPR data acquired along a single survey line. The main objective of this study is to analyze if the SEA-RTSM combination can improve the azimuth calculation obtained from the usual single-offset-RTSM (SO-RTSM) procedure. This possibility is based on the SEA ability of increasing the continuity and amplitude of the primary reflections with respect to the background clutter and noise, which is expected to reduce the fluctuations involved in the RTSM calculation of the azimuth, so that its accuracy and precision are improved. A SEA methodology designed to be used in conjunction with the RTSM methodology is described. A procedure that optimizes the results of the SEA methodology is explained. A statistical RTSM calculation is adopted in order to obtain the final azimuth. Different relevant parameters of the soil and the array of emitters are varied in order to evaluate the SEA-RTSM methodology and its results. Numerically simulated and experimental data are used in this evaluation. The SEA-RTSM and the SO-RTSM results are compared between them. These results are also compared with an equivalent common-midpoint-RTSM (CMP-RTSM) calculation. Improved precision and accuracy are obtained from the SEA-RTSM methodology in the great majority of the examples. The height/width of the resulting azimuth distribution increases 102% in average when using this procedure instead of the usual SO-RTSM procedure, the average standard deviation diminishes 12%, and the average differences between the calculated and true azimuths reduce 34%. Minor improvements with respect to SO are obtained with the CMP-RTSM methodology. The proposed SEA-RTSM methodology and its results are especially relevant in civil engineering applications in which it is

  10. Correlations between the zeta potentials of silica hydride-based stationary phases, analyte retention behaviour and their ionic interaction descriptors.

    Science.gov (United States)

    Kulsing, Chadin; Yang, Yuanzhong; Munera, Caesar; Tse, Colby; Matyska, Maria T; Pesek, Joseph J; Boysen, Reinhard I; Hearn, Milton T W

    2014-03-19

    In this study, the zeta potentials of type-B silica, bare silica hydride, the so-called Diamond Hydride™ and phenyl substituted silica hydride stationary phases have been measured in aqueous-organic media and correction procedures developed to account for the more negative zeta potential values in media containing different acetonitrile contents. Retention studies of 16 basic, acidic and neutral compounds were also performed with these four stationary phases with mobile phases containing 0.1% (v/v) formic acid and various acetonitrile-water compositions ranging from 0-90% (v/v) acetonitrile. The retention properties of these analytes were correlated to the corrected stationary phase zeta potentials measured under these different mobile phase conditions with R(2) values ranging from 0.01 to 1.00, depending on the stationary phase and analyte type. Using linear solvation energy relationships, stationary phase descriptors for each stationary phase have been developed for the different mobile phase conditions. Very high correlations of the zeta potentials with the ionic interaction descriptors were obtained for the type-B silica and the Diamond Hydride™ phases and good correlation with bare silica hydride material whilst there was no correlation observed for the phenyl substituted silica hydride phase. The nature of the retention mechanisms which gives rise to these different observations is discussed. The described methods represent a useful new approach to characterize and assess the retention properties of silica-hydride based chromatographic stationary phases of varying bonded-phase coverage and chemistries, as would be broadly applicable to other types of stationary phase used in the separation sciences.

  11. Acute arsenious hydride intoxication. Four cases

    Energy Technology Data Exchange (ETDEWEB)

    Gosselin, B.; Mathieu, D.; Desprez-Nolf, M.; Cosson, A.; Goudemand, J.; Haguenoer, J.M.; Wattel, F.

    1982-02-06

    While engaged in the repair of a zinc furnace, 4 workers were accidentally exposed to arsenious hydride (AsH3) fumes. Acute intravascular haemolysis developed within a few hours. On admission, the patients immediately underwent exsanguino-transfusion; 8.2 to 10.2 l of blood were exchanged through a continuous perfusion pump at the rate of 1 l/hour. Two patients resumed diuresis during transfusion, but the other two required repeated haemodialysis. Between the 10th and 30th days, while renal function was gradually returning to normal, mildly megaloblastic anaemia developed. This was followed during the 3rd month by clinical and electric signs of polyneuritis of the lower and upper limbs, which subsequently regressed. Regular measurements of arsenic levels in the blood and urine were performed between and during exsanguino-transfusion and haemodialysis.

  12. Hydrogen desorption from nanostructured magnesium hydride composites

    Directory of Open Access Journals (Sweden)

    Brdarić Tanja P.

    2007-01-01

    Full Text Available The influence of 3d transition metal addition (Fe, Co and Ni on the desorption properties of magnesium hydride were studied. The ball milling of MgH2-3d metal blends was performed under Ar. Microstructural and morphological characterization were performed by XRD and SEM analysis, while the hydrogen desorption properties were investigated by DSC. The results show a strong correlation between the morphology and thermal stability of the composites. The complex desorption behavior (the existence of more than one desorption peak was correlated with the dispersion of the metal additive particles that appear to play the main role in the desorption. The desorption temperature can be reduced by more than 100 degrees if Fe is added as additive. The activation energy for H2 desorption from the MgH2-Fe composite is 120 kJ/mol, implying that diffusion controls the dehydration process.

  13. Review of magnesium hydride-based materials: development and optimisation

    NARCIS (Netherlands)

    Crivello, J. -C.; Dam, B.; Denys, R. V.; Dornheim, M.; Grant, D. M.; Huot, J.; Jensen, T. R.; de Jongh, P.|info:eu-repo/dai/nl/186125372; Latroche, M.; Milanese, C.; Milcius, D.; Walker, G. S.; Webb, C. J.; Zlotea, C.; Yartys, V. A.

    Magnesium hydride has been studied extensively for applications as a hydrogen storage material owing to the favourable cost and high gravimetric and volumetric hydrogen densities. However, its high enthalpy of decomposition necessitates high working temperatures for hydrogen desorption while the

  14. Direct observation of hydrides formation in cavity-grade niobium

    Directory of Open Access Journals (Sweden)

    F. Barkov

    2012-12-01

    Full Text Available Niobium is an important technological superconductor used to make radio frequency cavities for particle accelerators. Using laser confocal microscopy we have directly investigated hydride precipitates formation in cavity-grade niobium at 77 and 140 K. We have found that large hydrides were usually formed after chemical or mechanical treatments, which are known to lead to a strong degradation of the quality factor known as Q disease. From our experiments we can conclude that hydrides causing Q disease are islands with a characteristic thickness of ≳100  nm and in-plane dimensions 1–10  μm. Our results show that mechanical polishing uploads a lot of hydrogen into bulk niobium while electropolishing leads to a mild contamination. Vacuum treatments at 600–800°C are demonstrated to preclude large hydride formation in line with the absence of Q disease in similarly treated cavities.

  15. Materials science of Mg-Ni-based new hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Orimo, S.; Fujii, H. [Hiroshima Univ. (Japan). Faculty of Integrated Arts and Sciences

    2001-02-01

    One of the advantageous functional properties of Mg alloys (or compounds) is to exhibit the reversible hydriding reaction. In this paper, we present our systematic studies regarding the relationship between nanometer- or atomistic-scale structures and the specific hydriding properties of the Mg-Ni binary system, such as(1) nanostructured (n)-Mg{sub 2}Ni, (2) a mixture of n-Mg{sub 2}Ni and amorphous (a)-MgNi,(3) pure a-MgNi, and(4) n-MgNi{sub 2}. Further studies on(5) an a-MgNi-based system for clarifying the effect of the short-range ordering on the structural and hydriding properties and(6) a MgNi{sub 2}-based system for synthesizing the new Laves phase structure are also presented. The materials science of Mg-Ni-based new hydrides will provide indispensable knowledge for practically developing the Mg alloys as hydrogen-storage materials. (orig.)

  16. Structure and bonding of second-row hydrides

    OpenAIRE

    Blinder, S. M.

    2014-01-01

    The atomic orbitals, hybridization and chemical bonding of the most common hydrides of boron, carbon, nitrogen and oxygen are described. This can be very instructive for beginning students in chemistry and chemical physics.

  17. Artificial exomuscle investigations for applications--metal hydride.

    Science.gov (United States)

    Crevier, Marie-Charlotte; Richard, Martin; Rittenhouse, D Matheson; Roy, Pierre-Olivier; Bédard, Stéphane

    2007-03-01

    In pursuing the development of bionic devices, Victhom identified a need for technologies that could replace current motorized systems and be better integrated into the human body motion. The actuators used to obtain large displacements are noisy, heavy, and do not adequately reproduce human muscle behavior. Subsequently, a project at Victhom was devoted to the development of active materials to obtain an artificial exomuscle actuator. An exhaustive literature review was done at Victhom to identify promising active materials for the development of artificial muscles. According to this review, metal hydrides were identified as a promising technology for artificial muscle development. Victhom's investigations focused on determining metal hydride actuator potential in the context of bionics technology. Based on metal hydride properties and artificial muscle requirements such as force, displacement and rise time, an exomuscle was built. In addition, a finite element model, including heat and mass transfer in the metal hydride, was developed and implemented in FEMLAB software.

  18. DETERMINATION OF METAL HYDRIDE SYSTEMS CHARACTERISTICS WHILE HEATING

    Directory of Open Access Journals (Sweden)

    Yu. Kluchka

    2012-01-01

    Full Text Available Experimental dependence of the pressure of hydrogen in the hydride cartridge when it is heated is obtained. Experimental data prove the theoretical values with an accuracy of ≈ 6%.

  19. Bipolar Nickel-Metal Hydride Battery Being Developed

    Science.gov (United States)

    Manzo, Michelle A.

    1998-01-01

    The NASA Lewis Research Center has contracted with Electro Energy, Inc., to develop a bipolar nickel-metal hydride battery design for energy storage on low-Earth-orbit satellites. The objective of the bipolar nickel-metal hydride battery development program is to approach advanced battery development from a systems level while incorporating technology advances from the lightweight nickel electrode field, hydride development, and design developments from nickel-hydrogen systems. This will result in a low-volume, simplified, less-expensive battery system that is ideal for small spacecraft applications. The goals of the program are to develop a 1-kilowatt, 28-volt (V), bipolar nickel-metal hydride battery with a specific energy of 100 watt-hours per kilogram (W-hr/kg), an energy density of 250 W-hr/liter and a 5-year life in low Earth orbit at 40-percent depth-of-discharge.

  20. High-pressure synthesis of noble metal hydrides.

    Science.gov (United States)

    Donnerer, Christian; Scheler, Thomas; Gregoryanz, Eugene

    2013-04-07

    The formation of hydride phases in the noble metals copper, silver, and gold was investigated by in situ x-ray diffraction at high hydrogen pressures. In the case of copper, a novel hexagonal hydride phase, Cu2H, was synthesised at pressures above 18.6 GPa. This compound exhibits an anti-CdI2-type structure, where hydrogen atoms occupy every second layer of octahedral interstitial sites. In contrast to chemically produced CuH, this phase does not show a change in compressibility compared to pure copper. Furthermore, repeated compression (after decomposition of Cu2H) led to the formation of cubic copper hydride at 12.5 GPa, a phenomenon attributed to an alteration of the microstructure during dehydrogenation. No hydrides of silver (up to 87 GPa) or gold (up to 113 GPa) were found at both room and high temperatures.

  1. Artificial exomuscle investigations for applications-metal hydride

    Energy Technology Data Exchange (ETDEWEB)

    Crevier, Marie-Charlotte; Richard, Martin; Rittenhouse, D Matheson; Roy, Pierre-Olivier; Bedard, Stephane [Victhom Human Bionics Inc., Saint-Augustin-de-Desmaures, QC (Canada)

    2007-03-01

    In pursuing the development of bionic devices, Victhom identified a need for technologies that could replace current motorized systems and be better integrated into the human body motion. The actuators used to obtain large displacements are noisy, heavy, and do not adequately reproduce human muscle behavior. Subsequently, a project at Victhom was devoted to the development of active materials to obtain an artificial exomuscle actuator. An exhaustive literature review was done at Victhom to identify promising active materials for the development of artificial muscles. According to this review, metal hydrides were identified as a promising technology for artificial muscle development. Victhom's investigations focused on determining metal hydride actuator potential in the context of bionics technology. Based on metal hydride properties and artificial muscle requirements such as force, displacement and rise time, an exomuscle was built. In addition, a finite element model, including heat and mass transfer in the metal hydride, was developed and implemented in FEMLAB software. (review article)

  2. Out-of-pile accelerated hydriding of Zircaloy fasteners

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, J.C.

    1979-10-01

    Mechanical joints between Zircaloy and nickel-bearing alloys, mainly the Zircaloy-4/Inconel-600 combination, were exposed to water at 450/sup 0/F and 520/sup 0/F to study hydriding of Zircaloy in contact with a dissimilar metal. Accelerated hydriding of the Zircaloy occurred at both temperatures. At 450/sup 0/F the dissolved hydrogen level of the water was over ten times that at 520/sup 0/F. At 520/sup 0/F the initially high hydrogen ingress rate decreased rapidly as exposure time increased and was effectively shut off in about 25 days. Severely hydrided Zircaloy components successfully withstood thermal cycling and mechanical testing. Chromium plating of the nickel-bearing parts was found to be an effective and practical barrier in preventing nickel-alloy smearing and accelerated hydriding of Zircaloy.

  3. Hydrogen storage in sodium aluminum hydride.

    Energy Technology Data Exchange (ETDEWEB)

    Ozolins, Vidvuds; Herberg, J.L. (Lawrence Livermore National Laboratories, Livermore, CA); McCarty, Kevin F.; Maxwell, Robert S. (Lawrence Livermore National Laboratories, Livermore, CA); Stumpf, Roland Rudolph; Majzoub, Eric H.

    2005-11-01

    Sodium aluminum hydride, NaAlH{sub 4}, has been studied for use as a hydrogen storage material. The effect of Ti, as a few mol. % dopant in the system to increase kinetics of hydrogen sorption, is studied with respect to changes in lattice structure of the crystal. No Ti substitution is found in the crystal lattice. Electronic structure calculations indicate that the NaAlH{sub 4} and Na{sub 3}AlH{sub 6} structures are complex-ionic hydrides with Na{sup +} cations and AlH{sub 4}{sup -} and AlH{sub 6}{sup 3-} anions, respectively. Compound formation studies indicate the primary Ti-compound formed when doping the material at 33 at. % is TiAl{sub 3} , and likely Ti-Al compounds at lower doping rates. A general study of sorption kinetics of NaAlH{sub 4}, when doped with a variety of Ti-halide compounds, indicates a uniform response with the kinetics similar for all dopants. NMR multiple quantum studies of solution-doped samples indicate solvent interaction with the doped alanate. Raman spectroscopy was used to study the lattice dynamics of NaAlH{sub 4}, and illustrated the molecular ionic nature of the lattice as a separation of vibrational modes between the AlH{sub 4}{sup -} anion-modes and lattice-modes. In-situ Raman measurements indicate a stable AlH{sub 4}{sup -} anion that is stable at the melting temperature of NaAlH{sub 4}, indicating that Ti-dopants must affect the Al-H bond strength.

  4. Pure Azimuthal Shear of an Elastic Dielectric Material

    Directory of Open Access Journals (Sweden)

    Kuldeep Kumar

    2010-03-01

    Full Text Available The purpose of this research is to examine the effect of polarization for the problem of pure azimuthal shear of an elastic dielectric material. The present problem is investigated in context of finite deformation theory. In this paper, the author studied the effect of polarization on the stresses for Neoprene rubber and compare the results with elastic material (Mooney-Rivlin material graphically. Twisting of a rigid cylinder in an infinite elastic medium is considered as a special case in this research.

  5. Azimuthal Dependence of Pion Interferometry at the AGS

    CERN Document Server

    Lisa, M A; Alexander, J M; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D; Chance, J L; Chung, P; Cole, B; Crowe, K M; Das, A C; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A S; Hjort, E L; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J C; Klay, J L; Krofcheck, D; Lacey, R A; Lauret, J; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D L; Panitkin, S Y; Pinkenburg, C H; Porile, N T; Rai, G; Ritter, H G; Romero, J L; Scharenberg, R P; Schröder, L; Srivastava, B; Stone, N T B; Symons, T J M; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Zhang Wei Ning

    2000-01-01

    Two-pion correlation functions, measured as a function of azimuthal emission angle with respect to the reaction plane, provide novel information on the anisotropic shape and orientation of the pion-emitting zone formed in heavy ion collisions. We present the first experimental determination of this information, for semi-central Au+Au collisions at 2-6 AGeV. The source extension perpendicular to the reaction plane is greater than the extension in the plane, and tilt of the pion source in coordinate space is found to be opposite its tilt in momentum space.

  6. Electronic structure of ternary hydrides based on light elements

    Energy Technology Data Exchange (ETDEWEB)

    Orgaz, E. [Departamento de Fisica y Quimica Teorica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, CP 04510 Coyoacan, Mexico, D.F. (Mexico)]. E-mail: orgaz@eros.pquim.unam.mx; Membrillo, A. [Departamento de Fisica y Quimica Teorica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, CP 04510 Coyoacan, Mexico, D.F. (Mexico); Castaneda, R. [Departamento de Fisica y Quimica Teorica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, CP 04510 Coyoacan, Mexico, D.F. (Mexico); Aburto, A. [Departamento de Fisica, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, CP 04510 Coyoacan, Mexico, D.F. (Mexico)

    2005-12-08

    Ternary hydrides based on light elements are interesting owing to the high available energy density. In this work we focused into the electronic structure of a series of known systems having the general formula AMH{sub 4}(A=Li,Na,M=B,Al). We computed the energy bands and the total and partial density of states using the linear-augmented plane waves method. In this report, we discuss the chemical bonding in this series of complex hydrides.

  7. Ab-Initio Study of the Group 2 Hydride Anions

    Science.gov (United States)

    Harris, Joe P.; Wright, Timothy G.; Manship, Daniel R.

    2013-06-01

    The beryllium hydride (BeH)- dimer has recently been shown to be surprisingly strongly bound, with an electronic structure which is highly dependent on internuclear separation. At the equilibrium distance, the negative charge is to be found on the beryllium atom, despite the higher electronegativity of the hydrogen. The current study expands this investigation to the other Group 2 hydrides, and attempts to explain these effects. M. Verdicchio, G. L. Bendazzoli, S. Evangelisti, T. Leininger J. Phys. Chem. A, 117, 192, (2013)

  8. Suppression of the critical temperature in binary vanadium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, M.D., E-mail: michael.dolan@csiro.au [CSIRO Energy Technology, 1 Technology Court, Pullenvale, QLD 4069 (Australia); McLennan, K.G. [CSIRO Energy Technology, 1 Technology Court, Pullenvale, QLD 4069 (Australia); Chandra, D. [Department of Chemical and Materials Engineering, University of Nevada, Reno, Reno, NV 89557 (United States); Kochanek, M.A. [CSIRO Energy Technology, 1 Technology Court, Pullenvale, QLD 4069 (Australia); Song, G. [CSIRO Process Science and Engineering, Gate 4, Normanby Rd, Clayton, VIC 3168 (Australia)

    2014-02-15

    Highlights: • Addition of 10 mol% Cr to V increases the β-hydride T{sub C} to >200 °C. • Addition of 10 mol% Ni to V increases the β-hydride T{sub C} to >400 °C. • Addition of 10 mol% Al to V decreases the β-hydride T{sub C} to <30 °C. • V{sub 90}Al{sub 10} membrane can be cycled to <30 °C under H{sub 2} without β-hydride formation. -- Abstract: The tendency of vanadium-based alloy membranes to embrittle is the biggest commercialisation barrier for this hydrogen separation technology. Excessive hydrogen absorption and the α → β hydride transition both contribute to brittle failure of these membranes. Alloying is known to reduce absorption, but the influence of alloying on hydride phase formation under conditions relevant to membrane operation has not been studied in great detail previously. Here, the effect of Cr, Ni, and Al alloying additions on V–H phase equilibrium has been studied using hydrogen absorption measurements and in situ X-ray diffraction studies. The addition of 10 mol% Ni increases the critical temperature for α + β hydride formation to greater than 400 °C, compared to 170 °C for V. Cr also increases the critical temperature, to between 200 and 300 °C. The addition of 10 mol% Al, however, suppresses the critical temperature to less than 30 °C, thereby enabling this material to be cycled thermally and hydrostatically while precluding formation of the β-hydride phase. This is despite Al also decreasing hydrogen absorption. The implication of this finding is that one of the mechanisms of brittle failure in vanadium-based hydrogen-selective membranes has been eliminated, thereby increasing the robustness of this material relative to V.

  9. Method of selective reduction of polyhalosilanes with alkyltin hydrides

    Science.gov (United States)

    Sharp, Kenneth G.; D'Errico, John J.

    1989-01-01

    The invention relates to the selective and stepwise reduction of polyhalosilanes by reacting at room temperature or below with alkyltin hydrides without the use of free radical intermediates. Alkyltin hydrides selectively and stepwise reduce the Si--Br, Si--Cl, or Si--I bonds while leaving intact any Si--F bonds. When two or more different halogens are present on the polyhalosilane, the halogen with the highest atomic weight is preferentially reduced.

  10. Method of selective reduction of halodisilanes with alkyltin hydrides

    Science.gov (United States)

    D'Errico, John J.; Sharp, Kenneth G.

    1989-01-01

    The invention relates to the selective and sequential reduction of halodisilanes by reacting these compounds at room temperature or below with trialkyltin hydrides or dialkyltin dihydrides without the use of free radical intermediates. The alkyltin hydrides selectively and sequentially reduce the Si-Cl, Si-Br or Si-I bonds while leaving intact the Si-Si and Si-F bonds present.

  11. Electronic structure and optical properties of lightweight metal hydrides

    NARCIS (Netherlands)

    Setten, van M.J.; Popa, V.A.; Wijs, de G.A.; Brocks, G.

    2007-01-01

    We study the dielectric functions of the series of simple hydrides LiH, NaH, MgH2, and AlH3, and of the complex hydrides Li3AlH6, Na3AlH6, LiAlH4, NaAlH4, and Mg(AlH4)2, using first-principles density-functional theory and GW calculations. All compounds are large gap insulators with GW single-partic

  12. Optimization of Hydride Rim Formation in Unirradiated Zr 4 Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Hanson, Brady D.; MacFarlan, Paul J.

    2013-09-30

    The purpose of this work is to build on the results reported in the M2 milestone M2FT 13PN0805051, document number FCRD-USED-2013-000151 (Hanson, 2013). In that work, it was demonstrated that unirradiated samples of zircaloy-4 cladding could be pre-hydrided at temperatures below 400°C in pure hydrogen gas and that the growth of hydrides on the surface could be controlled by changing the surface condition of the samples and form a desired hydride rim on the outside diameter of the cladding. The work performed at Pacific Northwest National Laboratory since the issuing of the M2 milestone has focused its efforts to optimize the formation of a hydride rim on available zircaloy-4 cladding samples by controlling temperature variation and gas flow control during pre-hydriding treatments. Surface conditioning of the outside surface was also examined as a variable. The results of test indicate that much of the variability in the hydride thickness is due to temperature variation occurring in the furnaces as well as how hydrogen gas flows across the sample surface. Efforts to examine other alloys, gas concentrations, and different surface conditioning plan to be pursed in the next FY as more cladding samples become available

  13. Mechanochemical synthesis of nanostructured chemical hydrides in hydrogen alloying mills

    Energy Technology Data Exchange (ETDEWEB)

    Wronski, Z. [CANMET' s Materials Technology Laboratory, Natural Resources Canada, Ottawa (Canada) and Department of Mechanical Engineering, University of Waterloo, Waterloo, Ont., Canada N2L 3G1 (Canada)]. E-mail: zwronski@nrcan.gc.ca; Varin, R.A. [Department of Mechanical Engineering, University of Waterloo, Waterloo, Ont., Canada N2L 3G1 (Canada); Chiu, C. [Department of Mechanical Engineering, University of Waterloo, Waterloo, Ont., Canada N2L 3G1 (Canada); Czujko, T. [Department of Mechanical Engineering, University of Waterloo, Waterloo, Ont., Canada N2L 3G1 (Canada); Calka, A. [Department of Materials Science and Engineering, University of Wollongong, NSW 2518 (Australia)

    2007-05-31

    Mechanical alloying of magnesium metal powders with hydrogen in specialized hydrogen ball mills can be used as a direct route for mechanochemical synthesis of emerging chemical hydrides and hydride mixtures for advanced solid-state hydrogen storage. In the 2Mg-Fe system, we have successfully synthesized the ternary complex hydride Mg{sub 2}FeH{sub 6} in a mixture with nanometric Fe particles. The mixture of complex magnesium-iron hydride and nano-iron released 3-4 wt.%H{sub 2} in a thermally programmed desorption experiment at the range 285-295 {sup o}C. Milling of the Mg-2Al powder mixture revealed a strong competition between formation of the Al(Mg) solid solution and the {beta}-MgH{sub 2} hydride. The former decomposes upon longer milling as the Mg atoms react with hydrogen to form the hydride phase, and drive the Al out of the solid solution. The mixture of magnesium dihydride and nano-aluminum released 2.1 wt.%H{sub 2} in the temperature range 329-340 {sup o}C in the differential scanning calorimetry experiment. The formation of MgH{sub 2} was suppressed in the Mg-B system; instead, a hydrogenated amorphous phase (Mg,B)H {sub x}, was formed in a mixture with nanometric MgB{sub 2}. Annealing of the hydrogen-stabilized amorphous mixture produced crystalline MgB{sub 2}.

  14. Novel fuel cell stack with coupled metal hydride containers

    Science.gov (United States)

    Liu, Zhixiang; Li, Yan; Bu, Qingyuan; Guzy, Christopher J.; Li, Qi; Chen, Weirong; Wang, Cheng

    2016-10-01

    Air-cooled, self-humidifying hydrogen fuel cells are often used for backup and portable power sources, with a metal hydride used as the hydrogen storage material. To provide a stable hydrogen flow to the fuel cell stack, heat must be provided to the metal hydride. Conventionally, the heat released from the exothermic reaction of hydrogen and oxygen in the fuel cell stack to the exhaust air is used to heat a separate metal hydride container. In this case, the heat is only partially used instead of being more closely coupled because of the heat transfer resistances in the system. To achieve better heat integration, a novel scheme is proposed whereby hydrogen storage and single fuel cells are more closely coupled. Based on this idea, metal hydride containers in the form of cooling plates were assembled between each pair of cells in the stack so that the heat could be directly transferred to a metal hydride container of much larger surface-to-volume ratio than conventional separate containers. A heat coupled fuel cell portable power source with 10 cells and 11 metal hydride containers was constructed and the experimental results show that this scheme is beneficial for the heat management of fuel cell stack.

  15. The use of metal hydrides in fuel cell applications

    Directory of Open Access Journals (Sweden)

    Mykhaylo V. Lototskyy

    2017-02-01

    Full Text Available This paper reviews state-of-the-art developments in hydrogen energy systems which integrate fuel cells with metal hydride-based hydrogen storage. The 187 reference papers included in this review provide an overview of all major publications in the field, as well as recent work by several of the authors of the review. The review contains four parts. The first part gives an overview of the existing types of fuel cells and outlines the potential of using metal hydride stores as a source of hydrogen fuel. The second part of the review considers the suitability and optimisation of different metal hydrides based on their energy efficient thermal integration with fuel cells. The performances of metal hydrides are considered from the viewpoint of the reversible heat driven interaction of the metal hydrides with gaseous H2. Efficiencies of hydrogen and heat exchange in hydrogen stores to control H2 charge/discharge flow rates are the focus of the third section of the review and are considered together with metal hydride – fuel cell system integration issues and the corresponding engineering solutions. Finally, the last section of the review describes specific hydrogen-fuelled systems presented in the available reference data.

  16. Metal hydrides based high energy density thermal battery

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhigang Zak, E-mail: zak.fang@utah.edu [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Zhou, Chengshang; Fan, Peng [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Udell, Kent S. [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States); Bowman, Robert C. [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Vajo, John J.; Purewal, Justin J. [HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265 (United States); Kekelia, Bidzina [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States)

    2015-10-05

    Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH{sub 2} and TiMnV as a working pair. • High energy density can be achieved by the use of MgH{sub 2} to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH{sub 2} as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV{sub 0.62}Mn{sub 1.5} alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles.

  17. Metallographic and fractographic observations of hydrides during delayed hydride cracking in Zr-2.5% Nb alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, M.T.; Eadie, R.L. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical and Materials Engineering; Shek, G.K.; Seahra, H. [Ontario Hydro Technologies, Toronto, Ontario (Canada)

    1998-01-01

    Potential drop measurements, optical microscopy, and scanning electron microscopy were performed to study the mechanism of delayed hydride cracking (DHC), the relation of the fracture to the hydride morphology, and the fractography of the DHC mechanism. The material used in this study was taken from modified extrusions of the material used to manufacture Zr-2.5% Nb pressure tubes. The material was electrolytically hydrided to approximately 60 {micro}g/g before testing. Cracking tests were carried out at 250 C with an applied K{sub 1} of 12 MPa {radical}m. The number of potential jumps was strongly correlated to the number of striations on the fracture surface. The results indicate that the DHC process occurs in these samples in an intermittent fashion. Brittle fracture is the operating fracture mechanism for the hydrides that cover most of the fracture surface, but there are some regions of ductile fracture both within the fracture and at the striations.

  18. Trialkylborane-Assisted CO(2) Reduction by Late Transition Metal Hydrides.

    Science.gov (United States)

    Miller, Alexander J M; Labinger, Jay A; Bercaw, John E

    2011-01-01

    Trialkylborane additives promote reduction of CO(2) to formate by bis(diphosphine) Ni(II) and Rh(III) hydride complexes. The late transition metal hydrides, which can be formed from dihydrogen, transfer hydride to CO(2) to give a formate-borane adduct. The borane must be of appropriate Lewis acidity: weaker acids do not show significant hydride transfer enhancement, while stronger acids abstract hydride without CO(2) reduction. The mechanism likely involves a pre-equilibrium hydride transfer followed by formation of a stabilizing formate-borane adduct.

  19. SIDIS transverse spin azimuthal asymmetries at COMPASS: Multidimensional analysis

    CERN Document Server

    Parsamyan, Bakur

    2015-01-01

    Exploration of transverse spin structure of the nucleon via study of the spin (in)dependent azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS) and Drell-Yan (DY) reactions is one of the main aspects of the broad physics program of the COMPASS experiment (CERN, Switzerland). In past decade COMPASS has collected a considerable amount of polarized deuteron and proton SIDIS data while 2014 and 2015 runs were dedicated to the Drell-Yan measurements. Results on SIDIS azimuthal effects provided so far by COMPASS play an important role in general understanding of the three-dimensional nature of the nucleon. Giving access to the entire "twist-2" set of transverse momentum dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs) COMPASS data are being widely used in phenomenological analyses and experimental data fits. Recent unique and first ever x-$Q^{2}$-z-pT multidimensional results for transverse spin asymmetries obtained by COMPASS serve as a direct and unprece...

  20. Transverse spin azimuthal asymmetries in SIDIS at COMPASS: Multidimensional analysis

    CERN Document Server

    Parsamyan, Bakur

    2015-01-01

    One of the important objectives of the COMPASS experiment (CERN, SPS north area) is the exploration of transverse spin structure of nucleon via study of spin (in)dependent azimuthal asymmetries with semi-inclusive deep inelastic scattering (SIDIS) processes and recently also with Drell-Yan (DY) reactions. In the past twelve years series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and polarized $^6LiD$ and $NH_3$ targets. Drell-Yan measurements with high energy (190 GeV/c) pion beam and transversely polarized $NH_3$ target started in 2014 with a pilot-run have been followed by 140 days of data taking in 2015. The experimental results obtained by COMPASS for azimuthal effects in SIDIS play an important role in the general understanding of the three-dimensional nature of the nucleon and are widely used in theoretical analyses and global data fits. In addition, future first ever polarized DY-data from COMPASS compared with SIDIS results will open a new chapter probing ...

  1. Origin of azimuthal seismic anisotropy in oceanic plates and mantle

    Science.gov (United States)

    Becker, Thorsten W.; Conrad, Clinton P.; Schaeffer, Andrew J.; Lebedev, Sergei

    2014-09-01

    Seismic anisotropy is ubiquitous in the Earth's mantle but strongest in its thermo-mechanical boundary layers. Azimuthal anisotropy in the oceanic lithosphere and asthenosphere can be imaged by surface waves and should be particularly straightforward to relate to well-understood plate kinematics and large-scale mantle flow. However, previous studies have come to mixed conclusions as to the depth extent of the applicability of paleo-spreading and mantle flow models of anisotropy, and no simple, globally valid, relationships exist. Here, we show that lattice preferred orientation (LPO) inferred from mantle flow computations produces a plausible global background model for asthenospheric anisotropy underneath oceanic lithosphere. The same is not true for absolute plate motion (APM) models. A ˜200 km thick layer where the flow model LPO matches observations from tomography lies just below the ˜1200 °C isotherm of a half-space cooling model, indicating strong temperature-dependence of the processes that control the development of azimuthal anisotropy. We infer that the depth extent of shear, and hence the thickness of a relatively strong oceanic lithosphere, can be mapped this way. These findings for the background model, and ocean-basin specific deviations from the half-space cooling pattern, are found in all of the three recent and independent tomographic models considered. Further exploration of deviations from the background model may be useful for general studies of oceanic plate formation and dynamics as well as regional-scale tectonic analyses.

  2. Spatial-Frequency Azimuthally Stable Cartography of Biological Polycrystalline Networks

    Directory of Open Access Journals (Sweden)

    V. A. Ushenko

    2013-01-01

    Full Text Available A new azimuthally stable polarimetric technique processing microscopic images of optically anisotropic structures of biological tissues histological sections is proposed. It has been used as a generalized model of phase anisotropy definition of biological tissues by using superposition of Mueller matrices of linear birefringence and optical activity. The matrix element M44 has been chosen as the main information parameter, whose value is independent of the rotation angle of both sample and probing beam polarization plane. For the first time, the technique of concerted spatial-frequency filtration has been used in order to separate the manifestation of linear birefringence and optical activity. Thereupon, the method of azimuthally stable spatial-frequency cartography of biological tissues histological sections has been elaborated. As the analyzing tool, complex statistic, correlation, and fractal analysis of coordinate distributions of M44 element has been performed. The possibility of using the biopsy of the uterine wall tissue in order to differentiate benign (fibromyoma and malignant (adenocarcinoma conditions has been estimated.

  3. Non-azimuthal linear polarization in protoplanetary disks

    CERN Document Server

    Canovas, H; de Boer, J; Pinte, C; Avenhaus, H; Schreiber, M R

    2015-01-01

    Several studies discussing imaging polarimetry observations of protoplanetary disks use the so-called radial Stokes parameters Q_phi and U_phi to discuss the results. This approach has the advantage of providing a direct measure of the noise in the polarized images under the assumption that the polarization is azimuthal only, i.e., perpendicular to the direction towards the illuminating source. However, a detailed study of the validity of this assumption is currently missing. We aim to test whether departures from azimuthal polarization can naturally be produced by scattering processes in optically thick protoplanetary disks at near infrared wavelengths. We use the radiative transfer code MCFOST to create a generic model of a transition disk using different grain size distributions and dust masses. From these models we generate synthetic polarized images at 2.2\\mum. We find that even for moderate inclinations (e.g., i = 40degr), multiple scattering alone can produce significant (up to ~4.5% of the Q_phi image...

  4. Method for measurement of azimuth of a borehole while drilling

    Energy Technology Data Exchange (ETDEWEB)

    DiPersio, R.D.; Cobern, M.E.

    1989-03-21

    A method is described for determining the azimuth angle of a borehole being drilled by instruments contained downhole in the drillstring, including the steps of: sensing with accelerometer means, during a period of nonrotation of the drillstring, the components of Gx, Gy and Gz of the total gravity field Go at the location of the instrument; sensing with magnetometer means, during a period of nonrotation of the drillstring, the components of Hx, Hy and Hz of the total magnetic field Ho at the location of the instrument; the components Gz and Hz being along the axis of the drillstring, the components Gx and the components and Gy being orthogonal to Gz and the components Hx and Hy being orthogonal to Hz; rotating the magnetometer means with the drillstring and obtaining the parameter Hzr which is the Hz component of the magnetic field at the location of the instrument during rotation of the drillstring; determining Ho from values Hx, Hy and Hz sensed during nonrotation of the drillstring; determining the inclination angle of the drillstring; determining the dip angle of the magnetic field; determining the angle between the direction of the magnetic field and the axis of the drillstring at the location of the instrument from Ho and Hzr; and determining the azimuth angle.

  5. PERFORMANCE ANALYSIS OF AZIMUTH ELECTRONIC BEAM STEERING MODE SPACEBORNE SAR

    Institute of Scientific and Technical Information of China (English)

    Han Xiaodong; Xu Wei; Han Xiaolei

    2013-01-01

    Pointing angle and pattern of the antenna can be changed swiftly to actualize the azimuth beam scanning by using electronic beam steering,which makes the Synthetic Aperture Radar (SAR)system more flexible and achieve a high resolution or cover a long strip within short time span.When the pointing angle is steered away from boresight,some aberrations may appear on the antenna pattern,e.g.,the grating lobe appears,the main lobe gain decrease,and antenna pattern broadens,e.g.,the aberrations result in the worsening of system performance,and complicate the corresponding performance analysis method.Conventional computation methods of performance parameters do not account for the rapid change of the antenna pattern.It introduces remarkable errors when the scanning angle is large.In this paper,a method of calculating performance parameters is proposed for the beam steering mode,which achieves the parameters by the energy accumulation in time domain.Actually,the proposed method simulates the working process of SAR and obtains accurate performance parameters.Furthermore,we analyze the effects of the grating lobe on the Azimuth Ambiguity to Signal Ratio (AASR),and present the generic Pulse Repetition Frequency (PRF) choosing principle which can also prevent the ambiguous area from weighting by the grating lobe.Finally,the effect of the antenna configuration on the performance parameters is analyzed by a system example.

  6. A quantitative phase field model for hydride precipitation in zirconium alloys: Part II. Modeling of temperature dependent hydride precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Zhihua [The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen (China); PolyU Base (Shenzhen) Limited, Shenzhen (China); Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Hao, Mingjun [The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen (China); Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Guo, Xianghua [State Key Laboratory of Explosion and Safety Science, Beijing Institute of Technology, Beijing 100081 (China); Tang, Guoyi [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Shi, San-Qiang, E-mail: mmsqshi@polyu.edu.hk [The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen (China); PolyU Base (Shenzhen) Limited, Shenzhen (China); Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2015-04-15

    A quantitative free energy functional developed in Part I (Shi and Xiao, 2014 [1]) was applied to model temperature dependent δ-hydride precipitation in zirconium in real time and real length scale. At first, the effect of external tensile load on reorientation of δ-hydrides was calibrated against experimental observations, which provides a modification factor for the strain energy in free energy formulation. Then, two types of temperature-related problems were investigated. In the first type, the effect of temperature transient was studied by cooling the Zr–H system at different cooling rates from high temperature while an external tensile stress was maintained. At the end of temperature transients, the average hydride size as a function of cooling rate was compared to experimental data. In the second type, the effect of temperature gradients was studied in a one or two dimensional temperature field. Different boundary conditions were applied. The results show that the hydride precipitation concentrated in low temperature regions and that it eventually led to the formation of hydride blisters in zirconium. A brief discussion on how to implement the hysteresis of hydrogen solid solubility on hydride precipitation and dissolution in the developed phase field scheme is also presented.

  7. Kinetics of thermal decomposition of titanium hydride powder using in situ high-temperature X-ray diffraction (HTXRD

    Directory of Open Access Journals (Sweden)

    Hugo Ricardo Zschommler Sandim

    2005-09-01

    Full Text Available The thermal decomposition of titanium hydride powder (delta-phase to titanium (alpha-phase was investigated by means of thermogravimetric analysis (TGA and high-temperature X-ray diffraction (HTXRD in high vacuum. The delta-to-alpha phase transformation was followed in situ by HTXRD at temperatures varying from room temperature up to 1000 °C. The transformation was also analyzed as a function of time at isothermal conditions from 450 to 650 °C. The results of TGA show that the decomposition of the titanium hydride becomes significant at about 450 °C. Above 500 °C the decomposition is completed in times shorter than 50 minutes. The apparent activation energy for hydrogen desorption was found to be 63 ± 6 kJ.mol-1.

  8. Designing metal hydride complexes for water splitting reactions: a molecular electrostatic potential approach.

    Science.gov (United States)

    Sandhya, K S; Suresh, Cherumuttathu H

    2014-08-28

    The hydridic character of octahedral metal hydride complexes of groups VI, VII and VIII has been systematically studied using molecular electrostatic potential (MESP) topography. The absolute minimum of MESP at the hydride ligand (Vmin) and the MESP value at the hydride nucleus (VH) are found to be very good measures of the hydridic character of the hydride ligand. The increasing/decreasing electron donating feature of the ligand environment is clearly reflected in the increasing/decreasing negative character of Vmin and VH. The formation of an outer sphere metal hydride-water complex showing the HH dihydrogen interaction is supported by the location and the value of Vmin near the hydride ligand. A higher negative MESP suggested lower activation energy for H2 elimination. Thus, MESP features provided a way to fine-tune the ligand environment of a metal-hydride complex to achieve high hydridicity for the hydride ligand. The applicability of an MESP based hydridic descriptor in designing water splitting reactions is tested for group VI metal hydride model complexes of tungsten.

  9. Chemical Hydride Slurry for Hydrogen Production and Storage

    Energy Technology Data Exchange (ETDEWEB)

    McClaine, Andrew W

    2008-09-30

    The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH2 slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at a time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston

  10. Hydriding and Dehydriding Properties of Zinc Borohydride, Nickel, and Titanium-Added Magnesium Hydride

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Jun; Kwon, Sung Nam; Song, Myoung Youp [Chonbuk National University, Jeonju (Korea, Republic of)

    2015-11-15

    A Zn(BH{sub 4}){sub 2} sample was prepared by milling ZnCl{sub 2} and NaBH{sub 4} in a planetary ball mill under Ar gas. This sample contained NaCl. Then, 90 wt% MgH{sub 2}-5 wt% Zn(BH{sub 4}){sub 2}-2.5 wt% Ni-2.5 wt% Ti samples [named 90MgH{sub 2}-5Zn(BH{sub 4}){sub 2}-2.5Ni-2.5Ti] were prepared by milling in a planetary ball mill under H{sub 2} gas. The hydrogen absorption and release properties of the prepared samples were investigated. In particular, the variations of the initial hydriding and dehydriding rates with temperature were examined. SEM micrographs and XRD patterns of 90MgH{sub 2}-5Zn(BH{sub 4}){sub 2}-2.5Ni-2.5Ti after reactive mechanical grinding and after hydriding-dehydriding were also studied. Particle size distributions and BET specific surface areas of 90MgH{sub 2}-5Zn(BH{sub 4}){sub 2}-2.5Ni-2.5Ti after reactive mechanical grinding and after 11 hydriding-dehydriding cycles were analyzed. The 90MgH{sub 2}-5Zn(BH{sub 4}){sub 2}-2.5Ni-2.5Ti had an effective hydrogen storage capacity (the quantity of hydrogen absorbed for 60 min) of near 5 wt% (4.91 wt% at 593 K).

  11. Thermal conductivity measurements of copper-coated metal hydrides (LaNi{sub 5}, Ca{sub 0.6}Mm{sub 0.4}Ni{sub 5}, and LaNi{sub 4.75}Al{sub 0.25}) for use in metal hydride hydrogen compression systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Michael; Kim, Kwang J.; Hopkins, Ryan R. [Mechanical Engineering Department, University of Nevada, Reno, NV 89557 (United States); Gawlik, Keith [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393 (United States)

    2009-04-15

    This study was performed to supplement the limited data on metal hydrides by experimentally determining the thermal conductivity of various metal hydride powder pellets that underwent a copper coating process. Three different metal hydride powders were tested (LaNi{sub 5}, Ca{sub 0.6}Mm{sub 0.4}Ni{sub 5}, and LaNi{sub 4.75}Al{sub 0.25}) for their thermal conductivity, with variations in testing parameters, and with copper coating processes that varied from 30 to 60 s A testing apparatus was specifically designed for this experiment, and the study reported thermal conductivity values of 3-6 W/m-K. (author)

  12. Infrared Observations Of Saturn's Rings : Azimuthal Variations And Thermal Modeling

    Science.gov (United States)

    Leyrat, C.; Spilker, L. J.; Altobelli, N.; Pilorz, S.; Ferrari, C.; Edgington, S. G.; Wallis, B. D.; Nugent, C.; Flasar, M.

    2007-12-01

    Saturn's rings represent a collection of icy centimeter to meter size particles with their local dynamic dictated by self gravity, mutual collisions, surface roughness and thickness of the rings themselves. The infrared observations obtained by the CIRS infrared spectrometer on board Cassini over the last 3.5 year contain informations on the local dynamic, as the thermal signature of planetary rings is influenced both by the ring structure and the particle properties. The ring temperature is very dependent on the solar phase angle (Spilker et al., this issue), and on the local hour angle around Saturn, depending on whether or not particles' visible hemispheres are heated by the Sun. The geometric filling factor, which can be estimated from CIRS spectra, is less dependent on the local hour angle, suggesting that the non isothermal behavior of particles' surfaces have low impact, but it is very dependent on the spacecraft elevation for the A and C rings. The ring small scale structure can be explored using CIRS data. Variations of the filling factor with the local hour angle relative to the spacecraft azimuth reveals self-gravity wakes. We derive morphological parameters of such wakes in both A and B rings assuming that wakes can be modeled either by regularly spaced bars with infinite or finite optical depth. Our results indicates that wakes in the A ring are almost flat, with a ratio height/width ≈ 0.44 ± 0.16 and with a pitch angle relative to the orbital motion direction of ≍ 27deg. This is consistent with UVIS (Colwell et al., 2006) and VIMS data (Hedman et al., 2007). Such models are more difficult to constrain in the B ring, but small variations of the filling factor indicate that the pitch angle decreases drastically in this ring. We also present a new thermal bar model to explain azimuthal variations of temperatures in the A ring. We compare results with previous ring thermal models of spherical particles. The Cassini/CIRS azimuthal scans data set is

  13. Azimuthal Distributions in Intermediate Energy Heavy-Ion Collisions

    Science.gov (United States)

    Wilson, William Kenneth

    The azimuthal distributions of light particles (Z = 1,2) with respect to the entrance channel reaction plane are investigated with a view towards characterizing the modes of collective motion in intermediate energy heavy -ion collisions. A new technique for reaction plane determination from the distribution of light particles produced in a collision is developed and applied to Ar+V data. The data were acquired using the MSU 4pi Array, a new 215 element large solid angle detector system. At a beam energy of 35 MeV/nucleon, light charged particles are found to exhibit an enhanced emission in the reaction plane which increases with the mass of the detected particle. As the beam energy is increased to 100 MeV/nucleon, the anisotropy nearly vanishes, providing clues to the dynamics of these reactions in a transitional energy regime. The observed anisotropy contains signatures of two distinct modes of collective motion: attractive mean field deflection, and rotation of the fused system. A microscopic calculation based on mean-field mediated interactions plus nucleon-nucleon collisions reproduces both forms of collective motion and their associated azimuthal distributions. The calculation also suggests that the anisotropy due to mean -field deflection is established during the initial stages of the collision. The nature of the nuclear mean-field is further explored using data taken by the 4pi Array for peripheral 50 MeV/nucleon C induced reactions on C and Au targets. Although projectile fragments in grazing collisions are positively deflected by the coulomb force, a specific set of protons are found to be simultaneously attractively deflected by the mean-field towards the opposite side of the reaction plane. This direct observation of attractive mean field deflection supports aspects of the interpretation of the Ar+V data. Lastly, the experimental results are summarized and the potential for extracting more information about the dynamics of heavy-ion collisions using

  14. Parametric characterization and estimation of bi-azimuth dispersion of path components

    DEFF Research Database (Denmark)

    Yin, Xuefeng; Pedersen, Troels; Czink, Nicolai;

    2006-01-01

    -Mises-Fisher distributions. The elements in this family maximize the entropy under the constraint that the expectations and correlation matrix of the directions are known. The probability density function (pdf) of the proposed distribution is used to describe the bi-azimuth power spectrum of individual path components....... An estimator of the parameters of the pdf is derived and applied to characterize the spreads in both azimuth of departure and azimuth of arrival, as well as the correlation between both azimuths of individual path components. Preliminary results from an experimental investigation demonstrate the applicability...

  15. Hydrogen storage as a hydride. Citations from the International Aerospace Abstracts data base

    Science.gov (United States)

    Zollars, G. F.

    1980-01-01

    These citations from the international literature concern the storage of hydrogen in various metal hydrides. Binary and intermetallic hydrides are considered. Specific alloys discussed are iron titanium, lanthanium nickel, magnesium copper and magnesium nickel among others.

  16. Hydrogen storage as a hydride. Citations from the International Aerospace Abstracts data base

    Science.gov (United States)

    Zollars, G. F.

    1980-01-01

    These citations from the international literature concern the storage of hydrogen in various metal hydrides. Binary and intermetallic hydrides are considered. Specific alloys discussed are iron titanium, lanthanium nickel, magnesium copper and magnesium nickel among others.

  17. Numerical simulation and performance test of metal hydride hydrogen storage system

    Directory of Open Access Journals (Sweden)

    Tzu-Hsiang Yen, Bin-Hao Chen, Bao-Dong Chen

    2011-05-01

    Full Text Available Metal hydride reactors are widely used in many industrial applications, such as hydrogen storage, thermal compression, heat pump, etc. According to the research requirement of metal hydride hydrogen storage, the thermal analyses have been implemented in the paper. The metal hydride reaction beds are considered as coupled cylindrical tube modules which combine the chemical absorption and desorption in metal hydride. The model is then used metal hydride LaNi5 as an example to predict the performance of metal hydride hydrogen storage devices, such as the position of hydration front and the thermal flux. Under the different boundary condition the characteristics of heat transfer and mass transfer in metal hydride have influence on the hydrogen absorption and desorption. The researches revealed that the scroll design can improve the temperature distribution in the reactor and the porous tube for directing hydrogen can increase the penetration depth of hydride reaction to decrease the hydrogen absorption time.

  18. Micro-scale fracture experiments on zirconium hydrides and phase boundaries

    Science.gov (United States)

    Chan, H.; Roberts, S. G.; Gong, J.

    2016-07-01

    Fracture properties of micro-scale zirconium hydrides and phase boundaries were studied using microcantilever testing methods. FIB-machined microcantilevers were milled on cross-sectional surfaces of hydrided samples, with the most highly-stressed regions within the δ-hydride film, within the α-Zr or along the Zr-hydride interface. Cantilevers were notched using the FIB and then tested in bending using a nanoindenter. Load-displacement results show that three types of cantilevers have distinct deformation properties. Zr cantilevers deformed plastically. Hydride cantilevers fractured after a small amount of plastic flow; the fracture toughness of the δ-hydride was found to be 3.3 ± 0.4 MPam1/2 and SEM examination showed transgranular cleavage on the fracture surfaces. Cantilevers notched at the Zr-hydride interface developed interfacial voids during loading, at loads considerably lower than that which initiate brittle fracture of hydrides.

  19. A coupled transport and solid mechanics formulation with improved reaction kinetics parameters for modeling oxidation and decomposition in a uranium hydride bed.

    Energy Technology Data Exchange (ETDEWEB)

    Salloum, Maher N.; Shugard, Andrew D.; Kanouff, Michael P.; Gharagozloo, Patricia E.

    2013-03-01

    Modeling of reacting flows in porous media has become particularly important with the increased interest in hydrogen solid-storage beds. An advanced type of storage bed has been proposed that utilizes oxidation of uranium hydride to heat and decompose the hydride, releasing the hydrogen. To reduce the cost and time required to develop these systems experimentally, a valid computational model is required that simulates the reaction of uranium hydride and oxygen gas in a hydrogen storage bed using multiphysics finite element modeling. This SAND report discusses the advancements made in FY12 (since our last SAND report SAND2011-6939) to the model developed as a part of an ASC-P&EM project to address the shortcomings of the previous model. The model considers chemical reactions, heat transport, and mass transport within a hydride bed. Previously, the time-varying permeability and porosity were considered uniform. This led to discrepancies between the simulated results and experimental measurements. In this work, the effects of non-uniform changes in permeability and porosity due to phase and thermal expansion are accounted for. These expansions result in mechanical stresses that lead to bed deformation. To describe this, a simplified solid mechanics model for the local variation of permeability and porosity as a function of the local bed deformation is developed. By using this solid mechanics model, the agreement between our reacting bed model and the experimental data is improved. Additionally, more accurate uranium hydride oxidation kinetics parameters are obtained by fitting the experimental results from a pure uranium hydride oxidation measurement to the ones obtained from the coupled transport-solid mechanics model. Finally, the coupled transport-solid mechanics model governing equations and boundary conditions are summarized and recommendations are made for further development of ARIA and other Sandia codes in order for them to sufficiently implement the model.

  20. Azimuthal Asymmetries and Vibrational Modes in Bubble Pinch-off

    CERN Document Server

    Schmidt, Laura E

    2011-01-01

    The pressure-driven inertial collapse of a cylindrical void in an inviscid liquid is an integrable, Hamiltonian system that forms a finite-time singularity as the radius of the void collapses to zero. Here it is shown that when the natural cylindrical symmetry of the void is perturbed azimuthally, the perturbation modes neither grow nor decay, but instead cause constant amplitude vibrations about the leading-order symmetric collapse. Though the amplitudes are frozen in time, they grow relative to the mean radius which is collapsing to zero, eventually overtaking the leading-order symmetric implosion. Including weak viscous dissipation destroys the integrability of the underlying symmetric implosion, and the effect on the stability spectrum is that short-wavelength disturbances are now erased as the implosion proceeds. Introducing a weak rotational flow component to the symmetric implosion dynamics causes the vibrating shapes to spin as the mean radius collapses. The above theoretical scenario is compared to a...

  1. Optimal analysis of azimuthal features in the CMB

    CERN Document Server

    Osborne, Stephen; Smith, Kendrick

    2013-01-01

    We present algorithms for searching for azimuthally symmetric features in CMB data. Our algorithms are fully optimal for masked all-sky data with inhomogeneous noise, computationally fast, simple to implement, and make no approximations. We show how to implement the optimal analysis in both Bayesian and frequentist cases. In the Bayesian case, our algorithm for evaluating the posterior likelihood is so fast that we can do a brute-force search over parameter space, rather than using a Monte Carlo Markov chain. Our motivating example is searching for bubble collisions, a pre-inflationary signal which can be generated if multiple tunneling events occur in an eternally inflating spacetime, but our algorithms are general and should be useful in other contexts.

  2. A fast algorithm for 3D azimuthally anisotropic velocity scan

    KAUST Repository

    Hu, Jingwei

    2014-11-11

    © 2014 European Association of Geoscientists & Engineers. The conventional velocity scan can be computationally expensive for large-scale seismic data sets, particularly when the presence of anisotropy requires multiparameter scanning. We introduce a fast algorithm for 3D azimuthally anisotropic velocity scan by generalizing the previously proposed 2D butterfly algorithm for hyperbolic Radon transforms. To compute semblance in a two-parameter residual moveout domain, the numerical complexity of our algorithm is roughly O(N3logN) as opposed to O(N5) of the straightforward velocity scan, with N being the representative of the number of points in a particular dimension of either data space or parameter space. Synthetic and field data examples demonstrate the superior efficiency of the proposed algorithm.

  3. Azimuthal angular correlations in high transverse momentum dijet events

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The azimuthal angle correlation between the two jets with the largest transverse momenta in inclusive 2-jet topologies, close to the back-to-back configuration, is measured for several regions of the leading jet transverse momentum. Measurements of the same observable requiring the presence of extra jets are also presented. The analysis is based on proton-proton collision data collected with the CMS experiment at a center-of-mass energy of $13~\\mathrm{TeV}$ corresponding to an integrated luminosity of $35.9~\\mathrm{fb}^{-1}$. The results are compared to predictions using Monte Carlo event generators which combine perturbative QCD calculations up to next-to-leading-order accuracy with contributions from parton showers, hadronization, and multiparton interactions.

  4. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mali, P.; Mukhopadhyay, A., E-mail: amitabha-62@rediffmail.com; Sarkar, S. [University of North Bengal, Department of Physics (India); Singh, G. [SUNY at Fredonia, Department of Computer and Information Science (United States)

    2015-03-15

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from {sup 84}Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from {sup 28}Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured.

  5. Nonmodal analysis of helical and azimuthal magnetorotational instabilities

    CERN Document Server

    Mamatsashvili, G

    2016-01-01

    The helical and the azimuthal magnetorotational instabilities operate in rotating magnetized flows with relatively steep negative or extremely steep positive shear. The corresponding lower and upper Liu limits of the shear, which determine the threshold of modal growth of these instabilities, are continuously connected when some axial electrical current is allowed to pass through the rotating fluid. We investigate the nonmodal dynamics of these instabilities arising from the nonnormality of shear flow in the local approximation, generalizing the results of the modal approach. It is demonstrated that moderate transient/nonmodal amplification of both types of magnetorotational instability occurs within the Liu limits, where the system is stable according to modal analysis. We show that for the helical magnetorotational instability this magnetohydrodynamic behavior is closely connected with the nonmodal growth of the underlying purely hydrodynamic problem.

  6. Binaural sound localizer for azimuthal movement detection based on diffraction.

    Science.gov (United States)

    Kim, Keonwook; Choi, Anthony

    2012-01-01

    Sound localization can be realized by utilizing the physics of acoustics in various methods. This paper investigates a novel detection architecture for the azimuthal movement of sound source based on the interaural level difference (ILD) between two receivers. One of the microphones in the system is surrounded by barriers of various heights in order to cast the direction dependent diffraction of the incoming signal. The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source. Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively. Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall.

  7. Azimuthal swirl in liquid metal electrodes and batteries

    Science.gov (United States)

    Ashour, Rakan; Kelley, Douglas

    2016-11-01

    Liquid metal batteries consist of two molten metals with different electronegativity separated by molten salt. In these batteries, critical performance related factors such as the limiting current density are governed by fluid mixing in the positive electrode. In this work we present experimental results of a swirling flow in a layer of molten lead-bismuth alloy driven by electrical current. Using in-situ ultrasound velocimetery, we show that poloidal circulation appears at low current density, whereas azimuthal swirl becomes dominant at higher current density. The presence of thermal gradients produces buoyant forces, which are found to compete with those produced by current injection. Taking the ratio of the characteristic electromagnetic to buoyant flow velocity, we are able to predict the current density at which the flow becomes electromagnetically driven. Scaling arguments are also used to show that swirl is generated through self-interaction between the electrical current in the electrode with its own magnetic field.

  8. Azimuthally polarized cathodoluminescence from InP nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Brenny, B. J. M.; Osorio, C. I.; Polman, A., E-mail: polman@amolf.nl [Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Dam, D. van [COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Gómez Rivas, J. [COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); FOM Institute DIFFER, P.O. Box 6336, 5600 HH Eindhoven (Netherlands)

    2015-11-16

    We determine the angle and polarization dependent emission from 1.75 µm and 2.50 µm long InP nanowires by using cathodoluminescence polarimetry. We excite the vertical wires using a 5 keV electron beam, and find that the 880 nm bandgap emission shows azimuthally polarized rings, with the number of rings depending on the wire height. The data agree well with a model in which spontaneous emission from the wire emitted into the far field interferes with emission reflected off the substrate. From the model, the depth range from which the emission is generated is found to be up to 400 nm below the top surface of the wires, well beyond the extent of the primary electron cloud. This enables a probe of the carrier diffusion length in the InP nanowires.

  9. Some properties of the circular waveguide with azimuthally magnetized ferrite

    Science.gov (United States)

    Ivanov, Kamen P.; Georgiev, Georgi N.

    1990-05-01

    A comprehensive analysis of normal rotationally symmetric TE modes in a circular waveguide, filled with ferrite, magnetized azimuthally to remanence by a coaxial switching conductor of finite radius, is presented. The characteristic equation of the structure, derived in terms of Kummer and Tricomi confluent hypergeometric functions of complex parameter and variable, is solved numerically, using specially compiled tables of wave functions. Families of theoretically calculated nonreciprocal phase characteristics of the gyrotropic waveguide are shown in normalized form for the two latched states of remanent magnetization, a variety of ferrite parameters, and different values of switching conductor to waveguide radius ratio. The influence of structure geometry and parameters of anisotropic ferrite on normalized differential phase shift and cutoff frequency spectrum of the TE01 mode is discussed.

  10. Improvement of azimuthal homogeneity in permanent-magnet bearing rotors

    Science.gov (United States)

    Hull, J. R.; Rossing, T. D.; Mulcahy, T. M.; Uherka, K. L.

    1992-10-01

    Permanent magnets that are levitated and rotating over a bulk high-temperature superconductor (HTS) form the basis of many superconducting bearing designs. Experiments have shown that the rotational-loss 'coefficient of friction' for thrust bearings of this type can be as low as 8 x 10(exp -6). While the loss mechanisms of such bearings are not well understood, the azimuthal homogeneity of the rotating permanent magnet is believed to play an important role in determining the loss. One possible loss mechanism is magnetic hysteresis in the HTS, where the energy loss E per cycle is derived from the critical state model and given by E = K (Delta B)(sup 3)/J(sub c) where K is a geometric coefficient, Delta B is the variation in magnetic field at the surface of the HTS experienced during a rotation of the levitated magnet, and J(sub c) is the critical current density of the HTS. It is clear that a small decrease in Delta B (i.e., decreasing the azimuthal inhomogeneity of the rotating magnetic field) could have profound effects on decreasing E and the rotational coefficient of friction. The role of Delta B is also expected to be significant in reducing losses from eddy currents and other mechanisms. Low rotational losses in HTS bearings have been demonstrated only for levitated masses of several grams. For practical bearings, it is important to obtain these low losses with larger levitated masses. There are two main routes toward decreasing Delta B. The first is to improve the alignment of the magnetic particles during fabrication and to maintain close tolerances on grinding angles during manufacture of the permanent magnet. The second, the subject of this paper, is to provide correctional procedures after the magnet is fabricated.

  11. Investigation of Cracked Lithium Hydride Reactor Vessels

    Energy Technology Data Exchange (ETDEWEB)

    bird, e.l.; mustaleski, t.m.

    1999-06-01

    Visual examination of lithium hydride reactor vessels revealed cracks that were adjacent to welds, most of which were circumferentially located in the bottom portion of the vessels. Sections were cut from the vessels containing these cracks and examined by use of the metallograph, scanning electron microscope, and microprobe to determine the cause of cracking. Most of the cracks originated on the outer surface just outside the weld fusion line in the base material and propagated along grain boundaries. Crack depths of those examined sections ranged from {approximately}300 to 500 {micro}m. Other cracks were reported to have reached a maximum depth of 1/8 in. The primary cause of cracking was the creation of high tensile stresses associated with the differences in the coefficients of thermal expansion between the filler metal and the base metal during operation of the vessel in a thermally cyclic environment. This failure mechanism could be described as creep-type fatigue, whereby crack propagation may have been aided by the presence of brittle chromium carbides along the grain boundaries, which indicates a slightly sensitized microstructure.

  12. Transition-Metal Hydride Radical Cations.

    Science.gov (United States)

    Hu, Yue; Shaw, Anthony P; Estes, Deven P; Norton, Jack R

    2016-08-10

    Transition-metal hydride radical cations (TMHRCs) are involved in a variety of chemical and biochemical reactions, making a more thorough understanding of their properties essential for explaining observed reactivity and for the eventual development of new applications. Generally, these species may be treated as the ones formed by one-electron oxidation of diamagnetic analogues that are neutral or cationic. Despite the importance of TMHRCs, the generally sensitive nature of these complexes has hindered their development. However, over the last four decades, many more TMHRCs have been synthesized, characterized, isolated, or hypothesized as reaction intermediates. This comprehensive review focuses on experimental studies of TMHRCs reported through the year 2014, with an emphasis on isolated and observed species. The methods used for the generation or synthesis of TMHRCs are surveyed, followed by a discussion about the stability of these complexes. The fundamental properties of TMHRCs, especially those pertaining to the M-H bond, are described, followed by a detailed treatment of decomposition pathways. Finally, reactions involving TMHRCs as intermediates are described.

  13. Comparison of the interactions in the rare gas hydride and Group 2 metal hydride anions.

    Science.gov (United States)

    Harris, Joe P; Manship, Daniel R; Breckenridge, W H; Wright, Timothy G

    2014-02-28

    We study both the rare gas hydride anions, RG-H(-) (RG = He-Rn) and Group 2 (Group IIa) metal hydride anions, MIIaH(-) (MIIa = Be-Ra), calculating potential energy curves at the CCSD(T) level with augmented quadruple and quintuple basis sets, and extrapolating the results to the basis set limit. We report spectroscopic parameters obtained from these curves; additionally, we study the Be-He complex. While the RG-H(-) and Be-He species are weakly bound, we show that, as with the previously studied BeH(-) and MgH(-) species, the other MIIaH(-) species are strongly bound, despite the interactions nominally also being between two closed shell species: M(ns(2)) and H(-)(1s(2)). We gain insight into the interactions using contour plots of the electron density changes and population analyses. For both series, the calculated dissociation energy is significantly less than the ion/induced-dipole attraction term, confirming that electron repulsion is important in these species; this effect is more dramatic for the MIIaH(-) species than for RG-H(-). Our analyses lead us to conclude that the stronger interaction in the case of the MIIaH(-) species arises from sp and spd hybridization, which allows electron density on the MIIa atom to move away from the incoming H(-).

  14. The effect of stress state on zirconium hydride reorientation

    Science.gov (United States)

    Cinbiz, Mahmut Nedim

    Prior to storage in a dry-cask facility, spent nuclear fuel must undergo a vacuum drying cycle during which the spent fuel rods are heated up to elevated temperatures of ≤ 400°C to remove moisture the canisters within the cask. As temperature increases during heating, some of the hydride particles within the cladding dissolve while the internal gas pressure in fuel rods increases generating multi-axial hoop and axial stresses in the closed-end thin-walled cladding tubes. As cool-down starts, the hydrogen in solid solution precipitates as hydride platelets, and if the multiaxial stresses are sufficiently large, the precipitating hydrides reorient from their initial circumferential orientation to radial orientation. Radial hydrides can severely embrittle the spent nuclear fuel cladding at low temperature in response to hoop stress loading. Because the cladding can experience a range of stress states during the thermo-mechanical treatment induced during vacuum drying, this study has investigated the effect of stress state on the process of hydride reorientation during controlled thermo-mechanical treatments utilizing the combination of in situ X-ray diffraction and novel mechanical testing analyzed by the combination of metallography and finite element analysis. The study used cold worked and stress relieved Zircaloy-4 sheet containing approx. 180 wt. ppm hydrogen as its material basis. The failure behavior of this material containing radial hydrides was also studied over a range of temperatures. Finally, samples from reactor-irradiated cladding tubes were examined by X-ray diffraction using synchrotron radiation. To reveal the stress state effect on hydride reorientation, the critical threshold stress to reorient hydrides was determined by designing novel mechanical test samples which produce a range of stress states from uniaxial to "near-equibiaxial" tension when a load is applied. The threshold stress was determined after thermo-mechanical treatments by

  15. Sodium-based hydrides for thermal energy applications

    Science.gov (United States)

    Sheppard, D. A.; Humphries, T. D.; Buckley, C. E.

    2016-04-01

    Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH4) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH3- x F x , Na-based transition metal hydrides, NaBH4 and Na3AlH6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100 °C to more than 650 °C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

  16. Comparison of Hydrogen Elimination from Molecular Zinc and Magnesium Hydride Clusters

    NARCIS (Netherlands)

    Intemann, J.; Sirsch, Peter; Harder, Sjoerd

    2014-01-01

    In analogy to the previously reported tetranuclear magnesium hydride cluster with a bridged dianionic bis-beta-diketiminate ligand, a related zinc hydride cluster has been prepared. The crystal structures of these magnesium and zinc hydride complexes are similar: the metal atoms are situated at the

  17. Use of triammonium salt of aurin tricarboxylic acid as risk mitigant for aluminum hydride

    Science.gov (United States)

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2017-08-08

    A process and a resulting product by process of an aluminum hydride which is modified with by physically combining in a ball milling process an aluminum hydride with a triammonium salt of aurin tricarboxylic acid. The resulting product is an aluminum hydride which is resistant to air, ambient moisture, and liquid water while maintaining useful hydrogen storage and release kinetics.

  18. Comparison of Hydrogen Elimination from Molecular Zinc and Magnesium Hydride Clusters

    NARCIS (Netherlands)

    Intemann, J.; Sirsch, Peter; Harder, Sjoerd

    2014-01-01

    In analogy to the previously reported tetranuclear magnesium hydride cluster with a bridged dianionic bis-beta-diketiminate ligand, a related zinc hydride cluster has been prepared. The crystal structures of these magnesium and zinc hydride complexes are similar: the metal atoms are situated at the

  19. Investigation of metal hydride materials as hydrogen reservoirs for metal-hydrogen batteries

    Science.gov (United States)

    ONISCHAK

    1976-01-01

    The performance and suitability of various metal hydride materials were examined for use as possible hydrogen storage reservoirs for secondary metal-hydrogen batteries. Lanthanum pentanickel hydride appears as a probable candidate in terms of stable hydrogen supply under feasible thermal conditions. A kinetic model describing the decomposition rate data of the hydride has been developed.

  20. A study of advanced magnesium-based hydride and development of a metal hydride thermal battery system

    Science.gov (United States)

    Zhou, Chengshang

    Metal hydrides are a group of important materials known as energy carriers for renewable energy and thermal energy storage. A concept of thermal battery based on advanced metal hydrides is studied for heating and cooling of cabins in electric vehicles. The system utilizes a pair of thermodynamically matched metal hydrides as energy storage media. The hot hydride that is identified and developed is catalyzed MgH2 due to its high energy density and enhanced kinetics. TiV0.62Mn1.5, TiMn2, and LaNi5 alloys are selected as the matching cold hydride. A systematic experimental survey is carried out in this study to compare a wide range of additives including transitions metals, transition metal oxides, hydrides, intermetallic compounds, and carbon materials, with respect to their effects on dehydrogenation properties of MgH2. The results show that additives such as Ti and V-based metals, hydride, and certain intermetallic compounds have strong catalytic effects. Solid solution alloys of magnesium are exploited as a way to destabilize magnesium hydride thermodynamically. Various elements are alloyed with magnesium to form solid solutions, including indium and aluminum. Thermodynamic properties of the reactions between the magnesium solid solution alloys and hydrogen are investigated, showing that all the solid solution alloys that are investigated in this work have higher equilibrium hydrogen pressures than that of pure magnesium. Cyclic stability of catalyzed MgH2 is characterized and analyzed using a PCT Sievert-type apparatus. Three systems, including MgH2-TiH 2, MgH2-TiMn2, and MgH2-VTiCr, are examined. The hydrogenating and dehydrogenating kinetics at 300°C are stable after 100 cycles. However, the low temperature (25°C to 150°C) hydrogenation kinetics suffer a severe degradation during hydrogen cycling. Further experiments confirm that the low temperature kinetic degradation can be mainly related the extended hydrogenation-dehydrogenation reactions. Proof

  1. Iron Hydride Detection and Intramolecular Hydride Transfer in a Synthetic Model of Mono-Iron Hydrogenase with a CNS Chelate.

    Science.gov (United States)

    Durgaprasad, Gummadi; Xie, Zhu-Lin; Rose, Michael J

    2016-01-19

    We report the identification and reactivity of an iron hydride species in a synthetic model complex of monoiron hydrogenase. The hydride complex is derived from a phosphine-free CNS chelate that includes a Fe-C(NH)(═O) bond (carbamoyl) as a mimic of the active site iron acyl. The reaction of [((O═)C(HN)N(py)S(Me))Fe(CO)2(Br)] (1) with NaHBEt3 generates the iron hydride intermediate [((O═)C(HN)N(py)S(Me))Fe(H)(CO)2] (2; δFe-H = -5.08 ppm). Above -40 °C, the hydride species extrudes CH3S(-) via intramolecular hydride transfer, which is stoichiometrically trapped in the structurally characterized dimer μ2-(CH3S)2-[((O═)C(HN)N(Ph))Fe(CO)2]2 (3). Alternately, when activated by base ((t)BuOK), 1 undergoes desulfurization to form a cyclometalated species, [((O═)C(NH)NC(Ph))Fe(CO)2] (5); derivatization of 5 with PPh3 affords the structurally characterized species [((O═)C(NH)NC)Fe(CO)(PPh3)2] (6), indicating complex 6 as the common intermediate along each pathway of desulfurization.

  2. Simultaneous determination of hydride and non-hydride forming elements by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Benzo, Z. [Instituto Venezolano de Investigaciones Cientificas, IVIC, Altos de Pipe, Caracas (Venezuela, Bolivarian Republic of); Matos-Reyes, M.N.; Cervera, M.L.; Guardia, M. de la, E-mail: m.luisa.cervera@uv.es [Department of Analytical Chemistry, University of Valencia, Valencia (Spain)

    2011-09-15

    The operating characteristics of a dual nebulization system were studied including instrumental and chemical conditions for the hydride generation and analytical figures of merit for both, hydride and non hydride forming elements. Analytical performance of the nebulization system was characterized by detection limits from 0.002 to 0.0026 {mu}g mL{sup -1} for the hydride forming elements and between 0.0034 and 0.0121 {mu}g mL{sup -1} for the non-hydride forming elements, relative standard deviation for 10 replicate measurements at 0.25 mg L{sup -1} level and recovery percentages between 97 and 103%. The feasibility of the system was demonstrated in the simultaneous determination of Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Zn, As, Bi, Sb, Se, and Te in the NIST 1549 (non-fat milk powder), NIST 1570a (spinach leaves), DORM-2 (dogfish muscle) and TORT-2 (lobster hepatopancreas) certified samples for trace elements. Results found were in good agreement with the certified ones. (author)

  3. Theoretical Estimate of Hydride Affinities of Aromatic Carbonyl Compounds

    Institute of Scientific and Technical Information of China (English)

    AI Teng; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Aromatic carbonyl compounds are one type of the most important organic compounds, and the reductions ofthem by hydride agents such as LiAlH4 or NaBH4 are widely used in organic synthesis. The reactivity of carbonyl compounds generally increases in the following order: ketone < aldehyde, and amide < acid < ester < acid halide, which could be related to their hydride affinities (HA). In the previous paper, Robert[1] calculated the absolute HAof a series of small non-aromatic carbonyl compounds. In this paper, we use DFT method at B3LYP/6-311 + + G (2d, 2p)∥B3LYP/6-31 + G* level to estimate hydride affinities of five groups of aromatic carbonyl compounds. The detailed results are listed in Table 1.

  4. A nickel metal hydride battery for electric vehicles.

    Science.gov (United States)

    Ovshinsky, S R; Fetcenko, M A; Ross, J

    1993-04-09

    Widespread use of electric vehicles can have significant impact on urban air quality, national energy independence, and international balance of trade. An efficient battery is the key technological element to the development of practical electric vehicles. The science and technology of a nickel metal hydride battery, which stores hydrogen in the solid hydride phase and has high energy density, high power, long life, tolerance to abuse, a wide range of operating temperature, quick-charge capability, and totally sealed maintenance-free operation, is described. A broad range of multi-element metal hydride materials that use structural and compositional disorder on several scales of length has been engineered for use as the negative electrode in this battery. The battery operates at ambient temperature, is made of nontoxic materials, and is recyclable. Demonstration of the manufacturing technology has been achieved.

  5. CO2 hydrogenation on a metal hydride surface.

    Science.gov (United States)

    Kato, Shunsuke; Borgschulte, Andreas; Ferri, Davide; Bielmann, Michael; Crivello, Jean-Claude; Wiedenmann, Daniel; Parlinska-Wojtan, Magdalena; Rossbach, Peggy; Lu, Ye; Remhof, Arndt; Züttel, Andreas

    2012-04-28

    The catalytic hydrogenation of CO(2) at the surface of a metal hydride and the corresponding surface segregation were investigated. The surface processes on Mg(2)NiH(4) were analyzed by in situ X-ray photoelectron spectroscopy (XPS) combined with thermal desorption spectroscopy (TDS) and mass spectrometry (MS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). CO(2) hydrogenation on the hydride surface during hydrogen desorption was analyzed by catalytic activity measurement with a flow reactor, a gas chromatograph (GC) and MS. We conclude that for the CO(2) methanation reaction, the dissociation of H(2) molecules at the surface is not the rate controlling step but the dissociative adsorption of CO(2) molecules on the hydride surface.

  6. Zirconium hydride formation in Hanford production reactor process tubes

    Energy Technology Data Exchange (ETDEWEB)

    Winegardner, W.K.; Griggs, B.

    1967-12-01

    Examination of Zircaloy-2 process tubes from Hanford Production Reactors has revealed extensive zirconium hydride formation. In general, attack is limited to the downstream portions of tubes where aluminum spacers are located. Most of the hydride platelets are contained in a case or layer on the inner surface of the tube. It is not unusual to find cases 0.004 to 0.005 in. thick. Analyses of the 0.037 in. wall tubes with such cases intact often reveal hydrogen concentrations greater than 1000 ppM. Investigation indicates that the hydriding is the result of galvanic contact between aluminum and Zircaloy-2. The galvanic couple (contact between dissimilar metals in the presence of reactor cooling water which serves as the electrolyte) results in the cathodic charging of hydrogen into the Zircaloy.

  7. NUMERICAL ANALYSIS FOR HYDRIDING IN METAL HYDRIDE HYDROGEN STORAGE TANK%金属氢化物储氢器吸氢过程的数值分析

    Institute of Scientific and Technical Information of China (English)

    叶建华; 蒋利军; 李志念; 刘晓鹏; 王树茂

    2011-01-01

    Based on the principle of hydride adsorption, a one-dimensional mathematical model for hydriding in a cylindrical metal hydride hydrogen storage tank was established. The heat and mass transfer of metal hydride beds was computed by finite difference method. The variation in temperature and hydrogen concentration at different radial positions of the hydride layer was analyzed during the process of hydriding. The effects of supply pressure, heat convection coefficient and hydride layer radial thickness on the hydriding was studied. It is shown that hydride formation initially takes place uniformly all over the metal hydride layer, but with the process of hydriding, the hydriding rate at the core region is gradually slower than one at surface region. The increase of supply pressure and heat convection coefficient can accelerate the hydriding of the hydrogen storage tank. The effect of hydride layer radial thickness is significant on the hydriding rate, and the thinner hydride layer, the higher the hydriding rate.%基于金属氢化物吸氢基本特性,建立圆柱形金属氢化物储氢器吸氢过程的-维数学物理模型.采用有限差分法对金属氢化物床体的传热传质进行计算.分别研究金属氢化物床体各处温度和氢含量在吸氢过程中的变化以及氢气压力、对流传热系数和金属氢化物床体径向厚度对金属氢化物吸氢过程的影响.计算结果表明:初始阶段金属氢化物床均匀吸氢,但随着氢化过程的进行,其中心区域的吸氢速率逐渐低于边缘区域;增加吸氢压力、提高对流传热系数均可促进储氢器的吸氢;金属氢化物床的径向厚度对吸氢速率影响很大,金属氢化物床越薄,氢化反应的速度越快.

  8. The sup 252 Cf-source-driven noise measurements of unreflected uranium hydride cylinder subcriticality

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, J.T.; Pare, V.K.; Blakeman, E.D. (Oak Ridge National Lab., TN (United States))

    1991-01-01

    Subcritical neutron multiplication factors have been measured by the {sup 252}Cf-source-driven noise analysis method for unreflected, 15.0-cm-diam uranium hydride cylinders of varying heights. Because of the difficulty and cost of controlling the H/U ratio in damp uranium (93.2 wt% {sup 235}U) oxide power and fabricating sufficient material for experiments, few experiments have been performed with materials of low H/U ratios. These measurements may provide alternate information that can be used for verifying calculational methods since the H/U ratio for this material is 3.00. These measurements, which are the first application of this method to uranium hydride, were performed at the Los Alamos National Laboratory Critical Experiments Facility in 1989. These measurements were used to demonstrate the capability of this measurement method for this type of material and to provide a benchmark experiment for calculational methods with slightly moderated systems. Previous experiments by this method were for a wide variety of well-moderated systems or unmoderated uranium metal cylinders.

  9. A Comparative Study of Two Azimuth Based Non Standard Location Methods

    Science.gov (United States)

    2017-03-23

    Azimuthal Triangulation, Induced Perpendicular Bisector, Array Signal Processing, Skewed Seismic Network, Calibration, Ground Truth, Nuclear Explosion...affect the triangulation result (Table). This is yet another indication that the adaptive method J0 is robust. A COMPARATIVE STUDY OF TWO AZIMUTH

  10. AZIMUTHAL ASYMMETRY OF NEUTRAL PION EMISSION IN AU+AU REACTIONS AT 1-GEV NUCLEON

    NARCIS (Netherlands)

    VENEMA, LB; BRAAK, H; LOHNER, H; RASCHKE, AE; SIEMSSEN, RH; SUMBERA, M; WILSCHUT, HW; BERG, FD; KUHN, W; METAG, [No Value; NOTHEISEN, M; NOVOTNY, R; PFEIFFER, M; RITMAN, J; SCHWALB, O; GOBBI, A; HILDENBRAND, KD; HLAVAC, S; HOLZMANN, R; SIMON, RS; SODAN, U; TEH, K; WESSELS, JP; HERRMANN, N; WIENOLD, T; KOTTE, R; MOSNER, J; NEUBERT, W; WOHLFARTH, D; OSTENDORF, R; SCHUTZ, Y; BRUMMUND, N; SANTO, R

    1993-01-01

    The azimuthal angle distributions of neutral pions at midrapidity from Au+Au reactions at 1 GeV/nucleon incident energy have been measured. An enhanced emission of pi0's perpendicular to the reaction plane is observed. The azimuthal asymmetry is dependent on the pi0 momentum: the pi0 spectrum perpen

  11. High-Spin Cobalt Hydrides for Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Patrick L. [Univ. of Rochester, NY (United States)

    2013-08-29

    Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

  12. Phase I. Lanthanum-based Start Materials for Hydride Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Gschneidner, K. A. [Ames Lab., Ames, IA (United States); Schmidt, F. A. [Ames Lab., Ames, IA (United States); Frerichs, A. E. [Ames Lab., Ames, IA (United States); Ament, K. A. [Ames Lab., Ames, IA (United States)

    2013-08-20

    The purpose of Phase I of this work is to focus on developing a La-based start material for making nickel-metal (lanthanum)-hydride batteries based on our carbothermic-silicon process. The goal is to develop a protocol for the manufacture of (La1-xRx)(Ni1-yMy)(Siz), where R is a rare earth metal and M is a non-rare earth metal, to be utilized as the negative electrode in nickel-metal hydride (NiMH) rechargeable batteries.

  13. Review of magnesium hydride-based materials: development and optimisation

    Science.gov (United States)

    Crivello, J.-C.; Dam, B.; Denys, R. V.; Dornheim, M.; Grant, D. M.; Huot, J.; Jensen, T. R.; de Jongh, P.; Latroche, M.; Milanese, C.; Milčius, D.; Walker, G. S.; Webb, C. J.; Zlotea, C.; Yartys, V. A.

    2016-02-01

    Magnesium hydride has been studied extensively for applications as a hydrogen storage material owing to the favourable cost and high gravimetric and volumetric hydrogen densities. However, its high enthalpy of decomposition necessitates high working temperatures for hydrogen desorption while the slow rates for some processes such as hydrogen diffusion through the bulk create challenges for large-scale implementation. The present paper reviews fundamentals of the Mg-H system and looks at the recent advances in the optimisation of magnesium hydride as a hydrogen storage material through the use of catalytic additives, incorporation of defects and an understanding of the rate-limiting processes during absorption and desorption.

  14. Hydride formation in core-shell alloyed metal nanoparticles

    Science.gov (United States)

    Zhdanov, Vladimir P.

    2016-07-01

    The model and analysis presented are focused on hydride formation in nanoparticles with a Pd shell and a core formed by another metal. The arrangement of metal atoms is assumed to be coherent (no dislocations). The lattice strain distribution, elastic energy, and chemical potential of hydrogen atoms are scrutinized. The slope of the chemical potential (as a function of hydrogen uptake) is demonstrated to decrease with increasing the core volume, and accordingly the critical temperature for hydride formation and the corresponding hysteresis loops are predicted to decrease as well.

  15. Hydrogen Desorption from Mg Hydride: An Ab Initio Study

    Directory of Open Access Journals (Sweden)

    Simone Giusepponi

    2012-07-01

    Full Text Available Hydrogen desorption from hydride matrix is still an open field of research. By means of accurate first-principle molecular dynamics (MD simulations an Mg–MgH2 interface is selected, studied and characterized. Electronic structure calculations are used to determine the equilibrium properties and the behavior of the surfaces in terms of structural deformations and total energy considerations. Furthermore, extensive ab-initio molecular dynamics simulations are performed at several temperatures to characterize the desorption process at the interface. The numerical model successfully reproduces the experimental desorption temperature for the hydride.

  16. Ab-initio study of transition metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ramesh [Dept. of Physics, Feroze Gandhi Insititute of Engineering and Technology, Raebareli-229001 (India); Shukla, Seema, E-mail: sharma.yamini62@gmail.com; Dwivedi, Shalini, E-mail: sharma.yamini62@gmail.com; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics Feroze Gandhi College, Raebareli-229001 (India)

    2014-04-24

    We have performed ab initio self consistent calculations based on Full potential linearized augmented plane wave (FP-LAPW) method to investigate the optical and thermal properties of yttrium hydrides. From the band structure and density of states, the optical absorption spectra and specific heats have been calculated. The band structure of Yttrium metal changes dramatically due to hybridization of Y sp orbitals with H s orbitals and there is a net charge transfer from metal to hydrogen site. The electrical resistivity and specific heats of yttrium hydrides are lowered but the thermal conductivity is slightly enhanced due to increase in scattering from hydrogen sites.

  17. Azimuth space-variant properties of BiSAR with nonequal velocities

    Institute of Scientific and Technical Information of China (English)

    Yang Yonghong; Pi Yiming

    2008-01-01

    Bistatic SAR possesses characteristic of the azimuth space-variant when the velocities of transmitter and receiver are not equal.The geometric model of BiSAR with the parallel trajectories and the nonequal platform velocities is presented.Analyzing the motion relationship of transmitter and receiver,the formula of azimuth space-variant is derived in time domain.Via Taylor polynomial expansions,the azimuth space-variant is factorized by four terms: zero-order,first-order,second-order,and third-order term.And,their impacts on impulse response are illuminated.Some characteristics about azimuth space-variant of airborne BiSAR case are exhibited by simulation experiments,arid these simulated results are coincident with the formulae of azimuth space-variant.

  18. Experimental identification of an azimuthal current in a magnetic nozzle of a radiofrequency plasma thruster

    Science.gov (United States)

    Takahashi, Kazunori; Chiba, Aiki; Komuro, Atsushi; Ando, Akira

    2016-10-01

    The azimuthal plasma current in a magnetic nozzle of a radiofrequency plasma thruster is experimentally identified by measuring the plasma-induced magnetic field. The axial plasma momentum increases over about 20 cm downstream of the thruster exit due to the Lorentz force arising from the azimuthal current. The measured current shows that the azimuthal current is given by the sum of the electron diamagnetic drift and \\mathbf{E}× \\mathbf{B} drift currents, where the latter component decreases with an increase in the magnetic field strength; hence the azimuthal current approaches the electron diamagnetic drift one for the strong magnetic field. The Lorentz force calculated from the measured azimuthal plasma current and the radial magnetic field is smaller than the directly measured force exerted to the magnetic field, which indicates the existence of a non-negligible Lorentz force in the source tube.

  19. Exploring "aerogen-hydride" interactions between ZOF2 (Z = Kr, Xe) and metal hydrides: An ab initio study

    Science.gov (United States)

    Esrafili, Mehdi D.; Mohammadian-Sabet, Fariba

    2016-06-01

    In this work, a new σ-hole interaction formed between ZOF2 (Z = Kr and Xe) as the Lewis acid and a series of metal-hydrides HMX (M = Be, Mg, Zn and X = H, F, CN, CH3) is reported. The nature of this interaction, called "aerogen-hydride" interaction, is unveiled by molecular electrostatic potential, non-covalent interaction, quantum theory of atoms in molecules and natural bond orbital analyses. Our results indicate that the aerogen-hydride interactions are quite strong and can be comparable in strength to other σ-hole bonds. An important charge-transfer interaction is also associated with the formation of OF2Z⋯HMX complexes.

  20. Uranium Hydride Nucleation and Growth Model FY'16 ESC Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Richards, Andrew Walter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Holby, Edward F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schulze, Roland K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-12-20

    Uranium hydride corrosion is of great interest to the nuclear industry. Uranium reacts with water and/or hydrogen to form uranium hydride which adversely affects material performance. Hydride nucleation is influenced by thermal history, mechanical defects, oxide thickness, and chemical defects. Information has been gathered from past hydride experiments to formulate a uranium hydride model to be used in a Canned Subassembly (CSA) lifetime prediction model. This multi-scale computer modeling effort started in FY’13, and the fourth generation model is now complete. Additional high-resolution experiments will be run to further test the model.

  1. Chemical Hydride Slurry for Hydrogen Production and Storage

    Energy Technology Data Exchange (ETDEWEB)

    McClaine, Andrew W

    2008-09-30

    The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH2 slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at a time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston

  2. The influence of hydride on fracture toughness of recrystallized Zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiao-Hung, E-mail: 175877@mail.csc.com.tw [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China); China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chiang, Ming-Feng [China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chen, Yen-Chen [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China)

    2014-04-01

    In this work, RXA cladding tubes were hydrogen-charged to target hydrogen content levels between 150 and 800 wppm (part per million by weight). The strings of zirconium hydrides observed in the cross sections are mostly oriented in the circumferential direction. The fracture toughness of hydrided RXA Zircaloy-4 cladding was measured to evaluate its hydride embrittlement susceptibility. With increasing hydrogen content, the fracture toughness of hydrided RXA cladding decreases at both 25 °C and 300 °C. Moreover, highly localized hydrides (forming a hydride rim) aggravate the degradation of the fracture properties of RXA Zircaloy-4 cladding at both 25 °C and 300 °C. Brittle features in the form of quasi-cleavages and secondary cracks were observed on the fracture surface of the hydride rim, even for RXA cladding tested at 300 °C.

  3. Precision continuous high-strength Azimuth track for large telescopes

    Science.gov (United States)

    Antebi, Joseph; Kan, Frank W.

    2003-01-01

    A novel track joint was developed for the azimuth track of the 50-m diameter Large Millimeter Telescope (LMT) now under construction in Mexico at an elevation of 4,600 m. The track, which is 430 mm wide by 230 mm deep, must be flat to within +/- 0.3 mm, and the material hardness at least 290 Brinell. This design uses a partial penetration narrow gap groove weld on the top surface of the track and a splice plate welded to the underside of the track. Pre-camber of the joint compensates for weld shrinkage which is small because of the use of the narrow gap groove weld. The residual deviations from flatness are reduced to the required tolerance by adjusting anchor bolts using an optimization procedure. The feasibility of the design with respect to fabrication, strength, fatigue, and alignment was demonstrated by detailed finite element analyses, trial welding and alignment of full scale joints, and testing of the mechanical properties of the joint and adjacent metal.

  4. Two-jet astrosphere model: effect of azimuthal magnetic field

    CERN Document Server

    Golikov, E A; Alexashov, D B; Belov, N A

    2016-01-01

    Opher et al. (2015), Drake et al. (2015) have shown that the heliospheric magnetic field results in formation of two-jet structure of the solar wind flow in the inner heliosheath, i.e. in the subsonic region between the heliospheric termination shock and the heliopause. In this scenario the heliopause has a tube-like topology as compared with a sheet-like topology in the most models of the global heliosphere (e.g. Izmodenov and Alexashov, 2015). In this paper we explore the two-jet scenario for a simplified astrosphere in which 1) the star is at rest with respect to the circumstellar medium, 2) radial magnetic field is neglected as compared with azimuthal component, 3) the stellar wind outflow is assumed to be hypersonic (both the Mach number and the Alfv\\'enic Mach number are much greater than unity at the inflow boundary). We have shown that the problem can be formulated in dimensionless form, in which the solution depends only on one dimensionless parameter epsilon that is reciprocal of the Alfv\\'enic Mach...

  5. Azimuthal Magnetorotational Instability at low and high magnetic Prandtl numbers

    CERN Document Server

    Guseva, A; Willis, A P; Avila, M

    2016-01-01

    The magnetorotational instability (MRI) is considered to be one of the most powerful sources of turbulence in hydrodynamically stable quasi-Keplerian flows, such as those governing accretion disk flows. Although the linear stability of these flows with applied external magnetic field has been studied for decades, the influence of the instability on the outward angular momentum transport, necessary for the accretion of the disk, is still not well known. In this work we model Keplerian rotation with Taylor-Couette flow and imposed azimuthal magnetic field using both linear and nonlinear approaches. We present scalings of instability with Hartmann and Reynolds numbers via linear analysis and direct numerical simulations (DNS) for the two magnetic Prandtl numbers of $1.4 \\cdot 10^{-6}$ and $1$. Inside of the instability domains modes with different axial wavenumbers dominate, resulting in sub-domains of instabilities, which appear different for each $Pm$. The DNS show the emergence of 1- and 2-frequency spatio-te...

  6. The Large Binocular Telescope azimuth and elevation encoder system

    Science.gov (United States)

    Ashby, David S.; Sargent, Tom; Cox, Dan; Rosato, Jerry; Brynnel, Joar G.

    2008-08-01

    A typical high-resolution encoder interpolator relies on careful mechanical alignment of the encoder read-heads and tight electrical tolerances of the signal processing electronics to ensure linearity. As the interpolation factor increases, maintaining these tight mechanical and electrical tolerances becomes impractical. The Large Binocular Telescope (LBT) is designed to utilize strip-type encoders on the main axes. Because of the very large scale of the telescope, the accumulative length of the azimuth and elevation encoder strips exceeds 80 meters, making optical tape prohibitively expensive. Consequently, the designers of the LBT incorporated the far less expensive Farrand Controls Inductosyn® linear strip encoder to encode the positions of the main axes and the instrument rotators. Since the cycle pitch of these encoders is very large compared to that of optical strip encoders, the interpolation factor must also be large in order to achieve the 0.005 arcsecond encoder resolution as specified. The authors present a description of the innovative DSP-based hardware / software solution that adaptively characterizes and removes common systematic cycle-to-cycle encoder interpolation errors. These errors can be caused by mechanical misalignment, encoder manufacturing flaws, variations in electrical gain, signal offset or cross-coupling of the encoder signals. Simulation data are presented to illustrate the performance of the interpolation algorithm, and telemetry data are presented to demonstrate the actual performance of the LBT main-axis encoder system.

  7. Azimuthal Seismic Amplitude Difference Inversion for Fracture Weakness

    Science.gov (United States)

    Chen, Huaizhen; Zhang, Guangzhi; Ji, Yuxin; Yin, Xingyao

    2016-08-01

    Fracture weakness prediction is an important task in fractured reservoir analysis. We propose a new method to use seismic amplitude differences between azimuths to estimate the normal and tangential fracture weaknesses under the assumption that the anisotropic perturbation of the reflection coefficient is mainly induced by fractures. We first derive an expression of the reflection coefficient in terms of the normal and tangential fracture weaknesses for the case of an interface separating two fractured media. Then we use the linear fitting method to get the relationship between the two fracture weaknesses, and change the variables to precondition the inversion problem. The Bayesian framework, under the hypothesis of a Cauchy distribution prior information and a Gaussian distribution likelihood function, is employed to construct the objective function, and an initial low-frequency constraint is introduced to the objective function to make the inversion more stable. The conjugate gradient algorithm is adopted to solve the inverse problem. Tests on both synthetic and real data demonstrate that the normal and tangential fracture weaknesses can be estimated reasonably in the case of seismic data containing a moderate noise, and our inversion approach appears to be a stable method for predicting the fracture weaknesses.

  8. Azimuthal Metallicity Structure in the Milky Way Disk

    CERN Document Server

    Balser, Dana S; Anderson, L D; Bania, T M

    2015-01-01

    Elemental abundance patterns in the Galactic disk constrain theories of the formation and evolution of the Milky Way. HII region abundances are the result of billions of years of chemical evolution. We made radio recombination line and continuum measurements of 21 HII regions located between Galactic azimuth Az = 90-130 degree, a previously unexplored region. We derive the plasma electron temperatures using the line-to-continuum ratios and use them as proxies for the nebular [O/H] abundances, because in thermal equilibrium the abundance of the coolants (O, N, and other heavy elements) in the ionized gas sets the electron temperature, with high abundances producing low temperatures. Combining these data with our previous work produces a sample of 90 HII regions with high quality electron temperature determinations. We derive kinematic distances in a self-consistent way for the entire sample. The radial gradient in [O/H] is -0.082 +/- 0.014 dex/kpc for Az = 90-130 degree, about a factor of two higher than the a...

  9. Production and characterization of thin film group IIIB, IVB and rare earth hydrides by reactive evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Provo, James L., E-mail: jlprovo@verizon.net [Consultant, J.L. Provo Consulting, Trinity, Florida 34655-7179 (United States)

    2015-07-15

    A recent short history of reactive evaporation by D. M. Mattox [History Corner—A Short History of Reactive Evaporation, SVC Bulletin (Society of Vacuum Coaters, Spring 2014), p. 50–51] describes various methods for producing oxides, nitrides, carbides, and some compounds, but hydrides were not mentioned. A study was performed in the mid-1970s at the General Electric Company Neutron Devices Department in Largo, FL, by the author to study preparation of thin film hydrides using reactive evaporation and to determine their unique characteristics and properties. Films were produced of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), and the rare earth praseodymium (Pr), neodymium (Nd), gadolinium (Gd), dysprosium (Dy), and erbium (Er) hydrides by hot crucible filament and electron beam evaporation in atmospheres of deuterium and tritium gases. All-metal vacuum systems were used and those used with tritium were dedicated for this processing. Thin film test samples 1000 nm thick were prepared on 1.27 cm diameter molybdenum disk substrates for each occluder (i.e., an element that can react with hydrogen to form a hydride) material. Loading characteristics as determined by gas-to-metal atomic ratios, oxidation characteristics as determined by argon–sputter Auger analysis, film structure as determined by scanning electron microscope analysis, and film stress properties as determined by a double resonator technique were used to define properties of interest. Results showed hydrogen-to-metal atomic ratios varied from 1.5 to 2.0 with near maximum loading for all but Pr and Nd occluders which correlated with the oxidation levels observed, with all occluder oxidation levels being variable due to vacuum system internal processing conditions and the materials used. Surface oxide levels varied from ∼80 Å to over 1000 Å. For most films studied, results showed that a maximum loading ratio of near 2.0 and a minimum surface oxide level of ∼80 Å could be

  10. Hydrogen Storage in Porous Materials and Magnesium Hydrides

    NARCIS (Netherlands)

    Grzech, A.

    2013-01-01

    In this thesis representatives of two different types of materials for potential hydrogen storage application are presented. Usage of either nanoporous materials or metal hydrides has both operational advantages and disadvantages. A main objective of this thesis is to characterize the hydrogen

  11. Pore confined synthesis of magnesium boron hydride nanoparticles

    NARCIS (Netherlands)

    Au, Yuen S.; Yan, Yigang; De Jong, Krijn P.; Remhof, Arndt; De Jongh, Petra E.

    2014-01-01

    Nanostructured materials based on light elements such as Li, Mg, and Na are essential for energy storage and conversion applications, but often difficult to prepare with control over size and structure. We report a new strategy that is illustrated for the formation of magnesium boron hydrides,

  12. Novel baker's yeast catalysed hydride reduction of an epoxide moiety

    CSIR Research Space (South Africa)

    Horak, RM

    1995-02-27

    Full Text Available -4039(95)00043-7 Tetrahedron Letters, Vol. 36, No. 9, pp. 1541-1544, 1995 Elsevier Science Ltd Printed in Great Britain 0040-4039/95 $9.50+0.00 A Novel Baker's Yeast Catalysed Hydride Reduction of an Epoxide Moiety R. Marthinus Horak, Robin A...

  13. Release of hydrogen from nanoconfined hydrides by application of microwaves

    Science.gov (United States)

    Sanz-Moral, Luis Miguel; Navarrete, Alexander; Sturm, Guido; Link, Guido; Rueda, Miriam; Stefanidis, Georgios; Martín, Ángel

    2017-06-01

    The release of hydrogen from solid hydrides by thermolysis can be improved by nanoconfinement of the hydride in a suitable micro/mesoporous support, but the slow heat transfer by conduction through the support can be a limitation. In this work, a C/SiO2 mesoporous material has been synthesized and employed as matrix for nanoconfinement of hydrides. The matrix showed high surface area and pore volume (386 m2/g and 1.41 cm3/g), which enabled the confinement of high concentrations of hydride. Furthermore, by modification of the proportion between C and SiO2, the dielectric properties of the complex could be modified, making it susceptible to microwave heating. As with this heating method the entire sample is heated simultaneously, the heat transfer resistances associated to conduction were eliminated. To demonstrate this possibility, ethane 1,2-diaminoborane (EDAB) was embedded on the C/SiO2 matrix at concentrations ranging from 11 to 31%wt using a wet impregnation method, and a device appropriate for hydrogen release from this material by application of microwaves was designed with the aid of a numerical simulation. Hydrogen liberation tests by conventional heating and microwaves were compared, showing that by microwave heating hydrogen release can be initiated and stopped in shorter times.

  14. Hydrogen Storage in Porous Materials and Magnesium Hydrides

    NARCIS (Netherlands)

    Grzech, A.

    2013-01-01

    In this thesis representatives of two different types of materials for potential hydrogen storage application are presented. Usage of either nanoporous materials or metal hydrides has both operational advantages and disadvantages. A main objective of this thesis is to characterize the hydrogen stora

  15. Review of magnesium hydride-based materials: development and optimisation

    NARCIS (Netherlands)

    Crivello, J. -C.; Dam, B.; Denys, R. V.; Dornheim, M.; Grant, D. M.; Huot, J.; Jensen, T. R.; de Jongh, P.; Latroche, M.; Milanese, C.; Milcius, D.; Walker, G. S.; Webb, C. J.; Zlotea, C.; Yartys, V. A.

    2016-01-01

    Magnesium hydride has been studied extensively for applications as a hydrogen storage material owing to the favourable cost and high gravimetric and volumetric hydrogen densities. However, its high enthalpy of decomposition necessitates high working temperatures for hydrogen desorption while the slo

  16. Process of forming a sol-gel/metal hydride composite

    Science.gov (United States)

    Congdon, James W.

    2009-03-17

    An external gelation process is described which produces granules of metal hydride particles contained within a sol-gel matrix. The resulting granules are dimensionally stable and are useful for applications such as hydrogen separation and hydrogen purification. An additional coating technique for strengthening the granules is also provided.

  17. Hydrogen adsorption on palladium and palladium hydride at 1 bar

    DEFF Research Database (Denmark)

    Johansson, Martin; Skulason, Egill; Nielsen, Gunver

    2010-01-01

    The dissociative sticking probability for H-2 on Pd films supported on sputtered Highly Ordered Pyrolytic Graphite (HOPG) has been derived from measurements of the rate of the H-D exchange reaction at 1 bar. The sticking probability for H-2, S. is higher on Pd hydride than on Pd (a factor of 1...

  18. Pore confined synthesis of magnesium boron hydride nanoparticles

    NARCIS (Netherlands)

    Au, Yuen S.; Yan, Yigang; De Jong, Krijn P.; Remhof, Arndt; De Jongh, Petra E.

    2014-01-01

    Nanostructured materials based on light elements such as Li, Mg, and Na are essential for energy storage and conversion applications, but often difficult to prepare with control over size and structure. We report a new strategy that is illustrated for the formation of magnesium boron hydrides, relev

  19. Optimization of Internal Cooling Fins for Metal Hydride Reactors

    Directory of Open Access Journals (Sweden)

    Vamsi Krishna Kukkapalli

    2016-06-01

    Full Text Available Metal hydride alloys are considered as a promising alternative to conventional hydrogen storage cylinders and mechanical hydrogen compressors. Compared to storing in a classic gas tank, metal hydride alloys can store hydrogen at nearly room pressure and use less volume to store the same amount of hydrogen. However, this hydrogen storage method necessitates an effective way to reject the heat released from the exothermic hydriding reaction. In this paper, a finned conductive insert is adopted to improve the heat transfer in the cylindrical reactor. The fins collect the heat that is volumetrically generated in LaNi5 metal hydride alloys and deliver it to the channel located in the center, through which a refrigerant flows. A multiple-physics modeling is performed to analyze the transient heat and mass transfer during the hydrogen absorption process. Fin design is made to identify the optimum shape of the finned insert for the best heat rejection. For the shape optimization, use of a predefined transient heat generation function is proposed. Simulations show that there exists an optimal length for the fin geometry.

  20. Superconductivity and unexpected chemistry of germanium hydrides under pressure

    Science.gov (United States)

    Davari Esfahani, M. Mahdi; Oganov, Artem R.; Niu, Haiyang; Zhang, Jin

    2017-04-01

    Following the idea that hydrogen-rich compounds might be high-Tc superconductors at high pressures, and the very recent breakthrough in predicting and synthesizing hydrogen sulfide with record-high Tc=203 K , an ab initio evolutionary algorithm for crystal structure prediction was employed to find stable germanium hydrides. In addition to the earlier structure of germane with space group Ama2, we propose a C2/m structure, which is energetically more favorable at pressures above 278 GPa (with inclusion of zero-point energy). Our calculations indicate that the C2/m phase of germane is a superconductor with Tc=67 K at 280 GPa. Germane is found to become thermodynamically unstable to decomposition to hydrogen and the compound Ge3H11 at pressures above 300 GPa. Ge3H11 with space group I 4 ¯m 2 is found to become stable at above 285 GPa with Tc=43 K . We find that the pressure-induced phase stability of germanium hydrides is distinct from analogous isoelectronic systems, e.g., Si hydrides and Sn hydrides. Superconductivity stems from large electron-phonon coupling associated with the wagging, bending, and stretching intermediate-frequency modes derived mainly from hydrogen.

  1. Structural stability of complex hydrides LiBH4 revisited

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Vegge, Tejs

    2004-01-01

    A systematic approach to study the phase stability of LiBH4 based on ab initio calculations is presented. Three thermodynamically stable phases are identified and a new phase of Cc symmetry is proposed for the first time for a complex hydride. The x-ray diffraction pattern and vibrational spectra...

  2. Hydride encapsulation by molecular alkali-metal clusters.

    Science.gov (United States)

    Haywood, Joanna; Wheatley, Andrew E H

    2008-07-14

    The sequential treatment of group 12 and 13 Lewis acids with alkali-metal organometallics is well established to yield so-called ''ate' complexes, whereby the Lewis-acid metal undergoes nucleophilic attack to give an anion, at least one group 1 metal acting to counter this charge. However, an alternative, less well recognised, reaction pathway involves the Lewis acid abstracting hydride from the organolithium reagent via a beta-elimination mechanism. It has recently been shown that in the presence of N,N'-bidentate ligands this chemistry can be harnessed to yield a new type of molecular main-group metal cluster in which the abstracted LiH is effectively trapped, with the hydride ion occupying an interstitial site in the cluster core. Discussion focuses on the development of this field, detailing advances in our understanding of the roles of Lewis acid, organolithium, and amine substrates in the syntheses of these compounds. Structure-types are discussed, as are efforts to manipulate cluster geometry and composition as well as hydride-coordination. Embryonic mechanistic studies are reported, as well as attempts to generate hydride-encapsulation clusters under catalytic control.

  3. Optimizing Misch-Metal Compositions In Metal Hydride Anodes

    Science.gov (United States)

    Bugga, Ratnakumar V.; Halpert, Gerald

    1995-01-01

    Electrochemical cells based on metal hydride anodes investigated experimentally in effort to find anode compositions maximizing charge/discharge-cycle performances. Experimental anodes contained misch metal alloyed with various proportions of Ni, Co, Mn, and Al, and experiments directed toward optimization of composition of misch metal.

  4. Well-defined transition metal hydrides in catalytic isomerizations.

    Science.gov (United States)

    Larionov, Evgeny; Li, Houhua; Mazet, Clément

    2014-09-07

    This Feature Article intends to provide an overview of a variety of catalytic isomerization reactions that have been performed using well-defined transition metal hydride precatalysts. A particular emphasis is placed on the underlying mechanistic features of the transformations discussed. These have been categorized depending upon the nature of the substrate and in most cases discussed following a chronological order.

  5. Nanocrystalline Metal Hydrides Obtained by Severe Plastic Deformations

    Directory of Open Access Journals (Sweden)

    Jacques Huot

    2012-01-01

    Full Text Available It has recently been shown that Severe Plastic Deformation (SPD techniques could be used to obtain nanostructured metal hydrides with enhanced hydrogen sorption properties. In this paper we review the different SPD techniques used on metal hydrides and present some specific cases of the effect of cold rolling on the hydrogen storage properties and crystal structure of various types of metal hydrides such as magnesium-based alloys and body centered cubic (BCC alloys. Results show that generally cold rolling is as effective as ball milling to enhance hydrogen sorption kinetics. However, for some alloys such as TiV0.9Mn1.1 alloy ball milling and cold rolling have detrimental effect on hydrogen capacity. The exact mechanism responsible for the change in hydrogenation properties may not be the same for ball milling and cold rolling. Nevertheless, particle size reduction and texture seems to play a leading role in the hydrogen sorption enhancement of cold rolled metal hydrides.

  6. Metal hydrides for smart window and sensor applications

    NARCIS (Netherlands)

    Yoshimura, K.; Langhammer, C.; Dam, B.

    2013-01-01

    The hydrogenation of metals often leads to changes in optical properties in the visible range. This allows for fundamental studies of the hydrogenation process, as well as the exploration of various applications using these optical effects. Here, we focus on recent developments in metal hydride-base

  7. Tribochemical Decomposition of Light Ionic Hydrides at Room Temperature.

    Science.gov (United States)

    Nevshupa, Roman; Ares, Jose Ramón; Fernández, Jose Francisco; Del Campo, Adolfo; Roman, Elisa

    2015-07-16

    Tribochemical decomposition of magnesium hydride (MgH2) induced by deformation at room temperature was studied on a micrometric scale, in situ and in real time. During deformation, a near-full depletion of hydrogen in the micrometric affected zone is observed through an instantaneous (t MgH2 with reduced crystal size by mechanical deformation.

  8. KNH2-KH: a metal amide-hydride solid solution.

    Science.gov (United States)

    Santoru, Antonio; Pistidda, Claudio; Sørby, Magnus H; Chierotti, Michele R; Garroni, Sebastiano; Pinatel, Eugenio; Karimi, Fahim; Cao, Hujun; Bergemann, Nils; Le, Thi T; Puszkiel, Julián; Gobetto, Roberto; Baricco, Marcello; Hauback, Bjørn C; Klassen, Thomas; Dornheim, Martin

    2016-09-27

    We report for the first time the formation of a metal amide-hydride solid solution. The dissolution of KH into KNH2 leads to an anionic substitution, which decreases the interaction among NH2(-) ions. The rotational properties of the high temperature polymorphs of KNH2 are thereby retained down to room temperature.

  9. Modified Omega-k Algorithm for High-Speed Platform Highly-Squint Staggered SAR Based on Azimuth Non-Uniform Interpolation

    Directory of Open Access Journals (Sweden)

    Hong-Cheng Zeng

    2015-02-01

    Full Text Available In this work, the staggered SAR technique is employed for high-speed platform highly-squint SAR by varying the pulse repetition interval (PRI as a linear function of range-walk. To focus the staggered SAR data more efficiently, a low-complexity modified Omega-k algorithm is proposed based on a novel method for optimal azimuth non-uniform interpolation, avoiding zero padding in range direction for recovering range cell migration (RCM and saving in both data storage and computational load. An approximate model on continuous PRI variation with respect to sliding receive-window is employed in the proposed algorithm, leaving a residual phase error only due to the effect of a time-varying Doppler phase caused by staggered SAR. Then, azimuth non-uniform interpolation (ANI at baseband is carried out to compensate the azimuth non-uniform sampling (ANS effect resulting from continuous PRI variation, which is further followed by the modified Omega-k algorithm. The proposed algorithm has a significantly lower computational complexity, but with an equally effective imaging performance, as shown in our simulation results.

  10. Forward Modeling of Azimuthal Anisotropy to the Reflected P Wave of Coal Seam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-gong; DONG Shou-hua; YUE Jian-hua

    2006-01-01

    Under the condition of weak anisotropy, the relation of P-wave anisotropy in direction to fractures of coal seams was researched in order to forecast the density and the direction of the fractures. Although the approximate solution by Rüger is suitable for thick reservoirs, it has some limitations for the composite reflected wave from both roofs and floors of coal seams, as well as multiple reflections. So first, the phase velocity and group velocity as well as their travel time were calculated about the reflected P-wave of the coal seam. Then, the anisotropic coefficients of both roofs and floors were calculated by Rüger formulae and last, the section versus azimuth in fixed offset can be gotten by convolution. In addition, the relation of amplitude of the composite reflected wave to azimuth angle was discussed. The forward modelling results of the coal azimuth anisotropy show these: 1) the coal seam is the strong reflecting layer, but the change of the reflectivity caused by the azimuth anisotropy is smaller; 2) if the azimuth angle is parallel to the crack strike, the reflectivity reaches up to the maximum absolute value, however, if the azimuth angle is perpendicular to the crack strike, the absolute value of the reflection coefficient is minimum; and 3)the reflection coefficient is the cosine function of the azimuth angle and the period is π.

  11. Azimuthal cement evaluation with an acoustic phased-arc array transmitter: numerical simulations and field tests

    Science.gov (United States)

    Che, Xiao-Hua; Qiao, Wen-Xiao; Ju, Xiao-Dong; Wang, Rui-Jia

    2016-03-01

    We developed a novel cement evaluation logging tool, named the azimuthally acoustic bond tool (AABT), which uses a phased-arc array transmitter with azimuthal detection capability. We combined numerical simulations and field tests to verify the AABT tool. The numerical simulation results showed that the radiation direction of the subarray corresponding to the maximum amplitude of the first arrival matches the azimuth of the channeling when it is behind the casing. With larger channeling size in the circumferential direction, the amplitude difference of the casing wave at different azimuths becomes more evident. The test results showed that the AABT can accurately locate the casing collars and evaluate the cement bond quality with azimuthal resolution at the casing—cement interface, and can visualize the size, depth, and azimuth of channeling. In the case of good casing—cement bonding, the AABT can further evaluate the cement bond quality at the cement—formation interface with azimuthal resolution by using the amplitude map and the velocity of the formation wave.

  12. Azimuthal dependence of the Garton-Tomkins orbit in crossed magnetic and electric fields

    Science.gov (United States)

    Bleasdale, C.; Lewis, R. A.; Bruno-Alfonso, A.

    2016-08-01

    Work on classical closed orbits in the diamagnetic Kepler problem is predominately focused on the chaos observed in the polar launch angle as opposed to the azimuthal launch angle. This is due to atomic systems, along with widely studied external-field geometries (parallel magnetic and electric fields or pure magnetic field), being uniform in azimuthal angle, rendering the azimuthal angle unimportant. In the case of crossed magnetic and electric fields, this is no longer the case, and closed orbits do present an azimuthal launch angle dependence. In atomic systems, due to their spherical symmetry, the electric-field orientation in the plane perpendicular to the magnetic field does not affect the spectrum of orbits. However, in shallow n -type donors in anisotropic semiconductors such as silicon, the orientation of the external fields with respect to conduction-band valleys will be important. In this work we examine the Garton-Tomkins orbit in crossed magnetic and electric fields, and analyze how it and its harmonics' azimuthal dependencies behave through variation of the scaled field or scaled energy. At low scaled fields, harmonics have either twofold or fourfold azimuthal dependencies determined by the rotational symmetry of the individual harmonics. As the scaled field or scaled energy is increased, several harmonics undergo significant bifurcations, resulting in large azimuthal angular regions of essentially closed orbits, which will lead to strong resonances in experimental work.

  13. Thin-film metal hydrides for solar energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Mongstad, Trygve Tveiteraas

    2012-11-01

    Thin-film metal hydrides may become important solar energy materials in the future. This thesis demonstrates interesting material properties of metal hydride films, relevant for applications as semiconducting materials for photovoltaic (PV) solar cells and for regulation of light using smart window technology.The work presented here has comprised an experimental study, focusing on three different materials: Magnesium hydride (MgH2), magnesium nickel hydride (Mg2NiH4) and yttrium hydride (YHx). Reactive sputter deposition was used to prepare the metal hydride film samples.This synthesis method is relatively uncommon for metal hydrides. Here,the first demonstration of reactive sputtering synthesis for YHx and Mg2NiH4 is given. Different challenges in forming singlephase, pure metal hydrides were identified: MgH2 could not be deposited without 3-16% metallic Mg present in the films, and YHx was found to react strong-ly to oxygen (O) during the deposition process. On the other hand, Mg2NiH4 films formed easily and apparently without major metallic clusters and with low O content.Mg2NiH4 is a semiconductor with an optical band gap that is suitable for PV solar cells. This study has showed that films with promising electrical and optical properties can be synthesized using reactive cosputtering of Mg and Ni. Using optical methods, the band gap for the as deposited samples was estimated to 1.54-1.76 eV, depending on the Mg-Ni composition. The asdeposited films were amorphous or nano-crystalline, but could be crystallized into the high-temperature fcc structure of Mg2NiH4 using heat treatment at 523 K. The band gap of the crystalline films was 2.1-2.2 eV, depending on the composition.A pronounced photochromic reaction to visible and UV light was observed for transparent yttrium hydride (T-YHx) samples. The optical transmission was reduced when the samples were illuminated, and the original optical transmission was restored when the samples were kept under dark conditions

  14. Activation and discharge kinetics of metal hydride electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Stein Egil

    2003-07-01

    Potential step chronoamperometry and Electrochemical Impedance Spectroscopy (eis) measurements were performed on single metal hydride particles. For the {alpha}-phase, the bulk diffusion coefficient and the absorption/adsorption rate parameters were determined. Materials produced by atomisation, melt spinning and conventional casting were investigated. The melt spun and conventional cast materials were identical and the atomised material similar in composition. The particles from the cast and the melt spun material were shaped like parallelepipeds. A corresponding equation, for this geometry, for diffusion coupled to an absorption/adsorption reaction was developed. It was found that materials produced by melt spinning exhibited lower bulk diffusion (1.7E-14 m2/s) and absorption/adsorption reaction rate (1.0E-8 m/s), compared to materials produced by conventionally casting (1.1E-13 m2/s and 5.5E-8 m/s respectively). In addition, the influence of particle active surface and relative diffusion length were discussed. It was concluded that there are uncertainties connected to these properties, which may explain the large distribution in the kinetic parameters measured on metal hydride particles. Activation of metal hydride forming materials has been studied and an activation procedure, for porous electrodes, was investigated. Cathodic polarisation of the electrode during a hot alkaline surface treatment gave the maximum discharge capacity on the first discharge of the electrode. The studied materials were produced by gas atomisation and the spherical shape was retained during the activation. Both an AB{sub 5} and an AB{sub 2} alloy was successfully activated and discharge rate properties determined. The AB{sub 2} material showed a higher maximum discharge capacity, but poor rate properties, compared to the AB{sub 5} material. Reduction of surface oxides, and at the same time protection against corrosion of active metallic nickel, can explain the satisfying results of

  15. D Geological Outcrop Characterization: Automatic Detection of 3d Planes (azimuth and Dip) Using LiDAR Point Clouds

    Science.gov (United States)

    Anders, K.; Hämmerle, M.; Miernik, G.; Drews, T.; Escalona, A.; Townsend, C.; Höfle, B.

    2016-06-01

    Terrestrial laser scanning constitutes a powerful method in spatial information data acquisition and allows for geological outcrops to be captured with high resolution and accuracy. A crucial aspect for numerous geologic applications is the extraction of rock surface orientations from the data. This paper focuses on the detection of planes in rock surface data by applying a segmentation algorithm directly to a 3D point cloud. Its performance is assessed considering (1) reduced spatial resolution of data and (2) smoothing in the course of data pre-processing. The methodology is tested on simulations of progressively reduced spatial resolution defined by varying point cloud density. Smoothing of the point cloud data is implemented by modifying the neighborhood criteria during normals estima-tion. The considerable alteration of resulting planes emphasizes the influence of smoothing on the plane detection prior to the actual segmentation. Therefore, the parameter needs to be set in accordance with individual purposes and respective scales of studies. Fur-thermore, it is concluded that the quality of segmentation results does not decline even when the data volume is significantly reduced down to 10%. The azimuth and dip values of individual segments are determined for planes fit to the points belonging to one segment. Based on these results, azimuth and dip as well as strike character of the surface planes in the outcrop are assessed. Thereby, this paper contributes to a fully automatic and straightforward workflow for a comprehensive geometric description of outcrops in 3D.

  16. Metal Hydrides as hot carrier cell absorber materials

    Science.gov (United States)

    Wang, Pei; Wen, Xiaoming; Shrestha, Santosh; Conibeer, Gavin; Aguey-Zinsou, Kondo-Francois

    2016-09-01

    The hot Carrier Solar Cell (HCSC) allows the photon-induced hot carriers (the carriers with energy larger than the band gap) to be collected before they completely thermalise. The absorber of the HCSC should have a large phononic band gap to supress Klemens Decay, which results in a slow carrier cooling speed. In fact, a large phononic band gap likely exists in a binary compound whose constituent elements have a large mass ratio between each other. Binary hydrides with their overwhelming mass ratio of the constituent elements are important absorber candidates. Study on different types of binary hydrides as potential absorber candidates is presented in this paper. Many binary transition metal hydrides have reported theoretical or experimental phonon dispersion charts which show large phononic band gaps. Among these hydrides, the titanium hydride (TiHX) is outstanding because of its low cost, easy fabrication process and is relatively inert to air and water. A TiHX thin film is fabricated by directly hydrogenating an evaporated titanium thin film. Characterisation shows good crystal quality and the hydrogenation process is believed to be successful. Ultrafast transient absorption (TA) spectroscopy is used to study the electron cooling time of TiHX. The result is very noisy due to the low absorption and transmission of the sample. The evolution of the TA curves has been explained by band to band transition using the calculated band structure of TiH2. Though not reliable due to the high noise, decay time fitting at 700nm and 600nm shows a considerably slow carrier cooling speed of the sample.

  17. Synthesis of hydrides by interaction of intermetallic compounds with ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, Boris P., E-mail: tarasov@icp.ac.ru [Institute of Problems of Chemical Physics of the Russian Academy of Sciences, Chernogolovka 142432 (Russian Federation); Fokin, Valentin N.; Fokina, Evelina E. [Institute of Problems of Chemical Physics of the Russian Academy of Sciences, Chernogolovka 142432 (Russian Federation); Yartys, Volodymyr A., E-mail: volodymyr.yartys@ife.no [Institute for Energy Technology, Kjeller NO 2027 (Norway); Department of Materials Science and Engineering, Norwegian University of Science and Technology, Trondheim NO 7491 (Norway)

    2015-10-05

    Highlights: • Interaction of the intermetallics A{sub 2}B, AB, AB{sub 2}, AB{sub 5} and A{sub 2}B{sub 17} with NH{sub 3} was studied. • The mechanism of interaction of the alloys with ammonia is temperature-dependent. • Hydrides, hydridonitrides, disproportionation products or metal–N–H compounds are formed. • NH{sub 4}Cl was used as an activator of the reaction between ammonia and intermetallics. • Interaction with ammonia results in the synthesis of the nanopowders. - Abstract: Interaction of intermetallic compounds with ammonia was studied as a processing route to synthesize hydrides and hydridonitrides of intermetallic compounds having various stoichiometries and types of crystal structures, including A{sub 2}B, AB, AB{sub 2}, AB{sub 5} and A{sub 2}B{sub 17} (A = Mg, Ti, Zr, Sc, Nd, Sm; B = transition metals, including Fe, Co, Ni, Ti and nontransition elements, Al and B). In presence of NH{sub 4}Cl used as an activator of the reaction between ammonia and intermetallic alloys, their interaction proceeds at rather mild P–T conditions, at temperatures 100–200 °C and at pressures of 0.6–0.8 MPa. The mechanism of interaction of the alloys with ammonia appears to be temperature-dependent and, following a rise of the interaction temperature, it leads to the formation of interstitial hydrides; interstitial hydridonitrides; disproportionation products (binary hydride; new intermetallic hydrides and binary nitrides) or new metal–nitrogen–hydrogen compounds like magnesium amide Mg(NH{sub 2}){sub 2}. The interaction results in the synthesis of the nanopowders where hydrogen and nitrogen atoms become incorporated into the crystal lattices of the intermetallic alloys. The nitrogenated materials have the smallest particle size, down to 40 nm, and a specific surface area close to 20 m{sup 2}/g.

  18. Heat exchanger selection and design analyses for metal hydride heat pump systems

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.

    2016-01-01

    This study presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select...... the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used....... The thermo-physical properties of the heat transfer medium and geometrical parameters are varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each...

  19. Characterization of the New GBT Azimuth Track and Pointing Model

    Science.gov (United States)

    Hunter, T. R.; Constantikes, K. T.; Ghigo, F.; Brandt, J.; Grider, R.

    2008-01-01

    Following the completion of the mechanical aspect of the azimuth track refurbishment project (described in the October 2007 Newsletter), it was necessary to character- ize the performance of the new track and implement a new pointing model prior to the resumption of scheduled operations. The Precision Telescope Control System (PTCS) team was responsible for this effort, which required significant planning and development beginning a year ago in January 2007. Although there was high confidence that the refurbishment would yield a flatter and more resilient track, the possibility of remaining low-level features spurred the team to develop a robust technique for measuring track features prior to the April 30 shutdown. To characterize the track, the centerpiece instrument is a pair of two-axis gas-damped capacitive-readout inclinometers mounted on the ends of the elevation axle. With the new track, both the large scale (tens of degrees) and small scale structure has been greatly reduced, with an rms of 0.94 arcseconds (equivalent to 5.7 thousandths of an inch at the track radius). A repeated measurement of the new track over the timescale of a week has shown the remaining features to be stable, but it will be monitored occasionally during the coming year. The nighttime blind pointing performance now shows a standard deviation of 3.4" in cross-elevation, 3.7" in elevation, and 2.0 mm in focus. These rms values are improved by about 1" in elevation and 1 mm in focus over the previous model when compared under the same conditions in fall 2006 and spring 2007.

  20. Two-jet astrosphere model: effect of azimuthal magnetic field

    Science.gov (United States)

    Golikov, E. A.; Izmodenov, V. V.; Alexashov, D. B.; Belov, N. A.

    2017-01-01

    Opher et al., Drake, Swisdak and Opher have shown that the heliospheric magnetic field results in formation of two-jet structure of the solar wind flow in the inner heliosheath, i.e. in the subsonic region between the heliospheric termination shock (TS) and the heliopause. In this scenario, the heliopause has a tube-like topology as compared with a sheet-like topology in the most models of the global heliosphere. In this paper, we explore the two-jet scenario for a simplified astrosphere in which (1) the star is at rest with respect to the circumstellar medium, (2) radial magnetic field is neglected as compared with azimuthal component and (3) the stellar wind outflow is assumed to be hypersonic (both the Mach number and the Alfvénic Mach number are much greater than unity at the inflow boundary). We have shown that the problem can be formulated in dimensionless form, in which the solution depends only on one dimensionless parameter ε that is reciprocal of the Alfvénic Mach number at the inflow boundary. This parameter is proportional to stellar magnetic field. We present the numerical solution of the problem for various values of ε. Three first integrals of the governing ideal magnetohydrodynamic equations are presented, and we make use of them in order to get the plasma distribution in the jets. Simple relations between distances to the TS, astropause and the size of the jet are established. These relations allow us to determine the stellar magnetic field from the geometrical pattern of the jet-like astrosphere.

  1. Broadband azimuthal polarization conversion using gold nanowire enhanced step-index fiber.

    Science.gov (United States)

    Tuniz, Alessandro; Jain, Chhavi; Weidlich, Stefan; Schmidt, Markus A

    2016-02-01

    We show broadband azimuthal polarization state conversion using an entirely connectorized step-index fiber with a central gold nanowire. This device provides broadband polarization discrimination of the low-loss TE01 fiber mode with respect to all other modes, and converts light into the azimuthal polarization state, resulting in a high beam quality and an azimuthal conversion efficiency of 37%. The device is monolithically integrated into fiber circuitry, representing a new platform for plasmonics and fiber optics and enabling important applications in super-resolution microscopy, laser tweezing, and plasmonic superfocussing.

  2. Estimation of azimuth and slowness of teleseismic signals recorded by a local seismic network

    Institute of Scientific and Technical Information of China (English)

    靳平; 潘常周

    2002-01-01

    A new method that is applicable to local seismic networks to estimate the azimuth and slowness of teleseismic signals is introduced in the paper. The method is based on the correlation between the arrival times and station positions. The analyzed results indicate that the azimuth and slowness of teleseismic signals can be accurately estimated by the method. Average errors for azimuth and slowness measurements obtained by this method using data of Xi(an Digital Telemetry Seismic Network are 2.0o and 0.34 s/(o), respectively. The conclusions drawn from this study indicate that this method may be very useful to interpret teleseismic records of local seismic networks.

  3. Transformation of vector beams with radial and azimuthal polarizations in biaxial crystals

    CERN Document Server

    Turpin, Alex; Lizana, Angel; Torres-Ruiz, Fabián; Estévez, Irene; Moreno, Ignacio; Campos, Juan; Mompart, Jordi

    2015-01-01

    We present both experimentally and theoretically the transformation of radially and azimuthally polarized vector beams when they propagate through a biaxial crystal and are transformed by the conical refraction phenomenon. We show that, at the focal plane, the transverse pattern is formed by a ring-like light structure with an azimuthal node, being this node found at diametrically opposite points of the ring for radial/azimuthal polarizations. We also prove that the state of polarization of the transformed beams is conical refraction-like, i.e. that every two diametrically opposite points of the light ring are linearly orthogonally polarized.

  4. Heliostat tilt and azimuth angle charts and the heliostat orientation protractor

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, M.M.; Al-Rabghi, O.M. (Thermal Energy Dept., King Abdulaziz Univ., Jeddah 21413 (SA))

    1992-02-01

    This paper reports that using cartesian heliostat field coordinates analytical expressions were derived for the heliostat tilt angle s, and heliostat azimuth angle {gamma} (clockwise from south). These expressions are dependent on the field cartesian coordinates of the center of the heliostat and the solar zenith and azimuth angles (clockwise from south), {theta}{sub z} and {Psi}, respectively. Here, cylindrical coordinates are conveniently used to derive the expressions for the heliostat angles s and {gamma}. The expression of {gamma}is used to construct the so-called heliostat orientation protractor. The protractor is a useful tool to determine the instantaneous heliostat azimuth angle as will be illustrated.

  5. Exploiting azimuthal variance of scatterers for multiple-look SAR recognition

    Science.gov (United States)

    Bhanu, Bir; Jones, Grinnell, III

    2002-08-01

    The focus of this paper is optimizing the recognition of vehicles in Synthetic Aperture Radar (SAR) imagery using multiple SAR recognizers at different look angles. The variance of SAR scattering center locations with target azimuth leads to recognition system results at different azimuths that are independent, even for small azimuth deltas. Extensive experimental recognition results are presented in terms of receiver operating characteristic (ROC) curves to show the effects of multiple look angles on recognition performance for MSTAR vehicle targets with configuration variants, articulation, and occlusion.

  6. Anomalous enhancement of drilling rate in carbon fiber reinforced plastic using azimuthally polarized CO2 laser

    Science.gov (United States)

    Endo, Masamori; Araya, Naohiro; Kurokawa, Yuki; Uno, Kazuyuki

    2016-09-01

    We developed an azimuthally polarized pulse-periodic CO2 laser for high-performance drilling applications. We discovered an anomalous enhancement in the drilling rate with the azimuthally polarized beam compared to that with radially or randomly polarized beams. We drilled 0.45 mm-thick carbon fiber reinforced plastic (CFRP) using a focusing lens with a focal length of 50 mm and a numerical aperture (NA) of 0.09. The conditions other than polarization states were identical for all the experiments. The azimuthally polarized beam exhibited a drilling rate more than 10 times greater on average than those of the other two polarizations.

  7. Hydride structures in Ti-aluminides subjected to high temperature and hydrogen pressure charging conditions

    Science.gov (United States)

    Legzdina, D.; Robertson, I. M.; Birnbaum, H. K.

    1991-01-01

    The distribution and chemistry of hydrides produced in single and dual phase alloys with a composition near TiAl have been investigated by using a combination of TEM and X-ray diffraction techniques. The alloys were exposed at 650 C to 13.8 MPa of gaseous H2 for 100 h. In the single-phase gamma alloy, large hydrides preferentially nucleated on the grain boundaries and matrix dislocations and a population of small hydrides was distributed throughout the matrix. X-ray and electron diffraction patterns from these hydrides indicated that they have an fcc structure with a lattice parameter of 0.45 nm. EDAX analysis of the hydrides showed that they were enriched in Ti. The hydrides were mostly removed by vacuum annealing at 800 C for 24 h. On dissolution of the hydrides, the chemistry of hydride-free regions of the grain boundary returned to the matrix composition, suggesting that Ti segregation accompanied the hydride formation rather than Ti enrichment causing the formation of the hydride.

  8. Hydriding performances and modeling of a small-scale ZrCo bed

    Energy Technology Data Exchange (ETDEWEB)

    Koo, D.; Lee, J.; Park, J.; Paek, S.; Chung, H. [KAERI-UST, Yuseong, Daejeon (Korea, Republic of); Chang, M.H.; Yun, S.H.; Cho, S.; Jung, K.J. [NFRI, Yuseong, Daejeon (Korea, Republic of)

    2015-03-15

    In order to evaluate the performance of the hydriding of a ZrCo bed, a small-scale getter bed of ZrCo was designed and fabricated. The results show that the hydriding time at room temperature was somewhat shorter than that at higher temperatures of ZrCo and that the performance of hydriding at low temperatures of ZrCo was better than that at high temperatures of ZrCo. The experimental results of the hydrogen pressure of hydriding (ZrCoH{sub 2.8}) at different temperatures were in agreement with the computed values using a numerical modeling equation but with a small difference during the first 10 minutes of the hydriding of ZrCo. The model is based on the Kozeny-Carman equation. The effect of a helium blanket on hydriding was measured and analyzed. The hydriding with no helium blanket in the primary vessel of ZrCo is much faster than that with a helium blanket. The hydriding at a helium concentration of 8% is slower than that at 0%. As the helium concentration increases, the hydriding of ZrCo decreases. The experimental results of the hydriding with 0 %, 4%, and 8% of helium concentration are in agreement with the calculated values but with minimal differences during the first 10 minutes.

  9. Dissociation potential curves of low-lying states in transition metal hydrides. 3. Hydrides of groups 6 and 7.

    Science.gov (United States)

    Koseki, Shiro; Matsushita, Takeshi; Gordon, Mark S

    2006-02-23

    The dissociation curves of low-lying spin-mixed states in monohydrides of groups 6 and 7 were calculated by using an effective core potential (ECP) approach. This approach is based on the multiconfiguration self-consistent field (MCSCF) method, followed by first-order configuration interaction (FOCI) calculations, in which the method employs an ECP basis set proposed by Stevens and co-workers (SBKJC) augmented by a set of polarization functions. Spin-orbit coupling (SOC) effects are estimated within the one-electron approximation by using effective nuclear charges, since SOC splittings obtained with the full Breit-Pauli Hamitonian are underestimated when ECP basis sets are used. The ground states of group 6 hydrides have Omega = (1)/(2)(X(6)Sigma(+)(1/2)), where Omega is the z component of the total angular momentum quantum number. Although the ground states of group 7 hydrides have Omega = 0(+), their main adiabatic components are different; the ground state in MnH originates from the lowest (7)Sigma(+), while in TcH and ReH the main component of the ground state is the lowest (5)Sigma(+). The present paper reports a comprehensive set of theoretical results including the dissociation energies, equilibrium distances, electronic transition energies, harmonic frequencies, anharmonicities, and rotational constants for several low-lying spin-mixed states in these hydrides. Transition dipole moments were also computed among the spin-mixed states and large peak positions of electronic transitions are suggested theoretically for these hydrides. The periodic trends of physical properties of metal hydrides are discussed, based on the results reported in this and other recent studies.

  10. Heavy hydrides: H2Te ultraviolet photochemistry

    Science.gov (United States)

    Underwood, J.; Chastaing, D.; Lee, S.; Wittig, C.

    2005-08-01

    The room-temperature ultraviolet absorption spectrum of H2Te has been recorded. Unlike other group-6 hydrides, it displays a long-wavelength tail that extends to 400 nm. Dissociation dynamics have been examined at photolysis wavelengths of 266 nm (which lies in the main absorption feature) and 355 nm (which lies in the long-wavelength tail) by using high-n Rydberg time-of-flight spectroscopy to obtain center-of-mass translational energy distributions for the channels that yield H atoms. Photodissociation at 355 nm yields TeH(Π1/22) selectively relative to the TeH(Π3/22) ground state. This is attributed to the role of the 3A' state, which has a shallow well at large RH-TeH and correlates to H +TeH(Π1/22). Note that the Π1/22 state is analogous to the P1/22 spin-orbit excited state of atomic iodine, which is isoelectronic with TeH. The 3A' state is crossed at large R only by 2A″, with which it does not interact. The character of 3A' at large R is influenced by a strong spin-orbit interaction in the TeH product. Namely, Π1/22 has a higher degree of spherical symmetry than does Π3/22 (recall that I(P1/22) is spherically symmetric), and consequently Π1/22 is not inclined to form either strongly bonding or antibonding orbitals with the H atom. The 3A'←X transition dipole moment dominates in the long-wavelength region and increases with R. Structure observed in the absorption spectrum in the 380-400 nm region is attributed to vibrations on 3A'. The main absorption feature that is peaked at ˜240nm might arise from several excited surfaces. On the basis of the high degree of laboratory system spatial anisotropy of the fragments from 266 nm photolysis, as well as high-level theoretical studies, the main contribution is believed to be due to the 4A″ surface. The 4A″←X transition dipole moment dominates in the Franck-Condon region, and its polarization is in accord with the experimental observations. An extensive secondary photolysis (i.e., of nascent TeH) is

  11. Composite Materials for Hazard Mitigation of Reactive Metal Hydrides.

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Joseph William; Cordaro, Joseph Gabriel; Sartor, George B.; Dedrick, Daniel E.; Reeder, Craig L.

    2012-02-01

    In an attempt to mitigate the hazards associated with storing large quantities of reactive metal hydrides, polymer composite materials were synthesized and tested under simulated usage and accident conditions. The composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride. Composites with vinyl-containing siloxane oligomers were also polymerized with and without added styrene and divinyl benzene. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride reduced the inherent hydrogen storage capacity of the material. The composites were found to be initially effective at reducing the amount of heat released during oxidation. However, upon cycling the composites, the mitigating behavior was lost. While the polymer composites we investigated have mitigating potential and are physically robust, they undergo a chemical change upon cycling that makes them subsequently ineffective at mitigating heat release upon oxidation of the metal hydride. Acknowledgements The authors would like to thank the following people who participated in this project: Ned Stetson (U.S. Department of Energy) for sponsorship and support of the project. Ken Stewart (Sandia) for building the flow-through calorimeter and cycling test stations. Isidro Ruvalcaba, Jr. (Sandia) for qualitative experiments on the interaction of sodium alanate with water. Terry Johnson (Sandia) for sharing his expertise and knowledge of metal hydrides, and sodium alanate in particular. Marcina Moreno (Sandia) for programmatic assistance. John Khalil (United Technologies Research Corp) for insight into the hazards of reactive metal hydrides and real-world accident scenario experiments. Summary In an attempt to mitigate and/or manage hazards associated with storing bulk quantities of reactive metal hydrides, polymer composite materials (a mixture of a mitigating polymer and a metal hydride) were synthesized and tested

  12. Numerical simulation of azimuth electromagnetic wave tool response based on self-adaptive FEM

    Science.gov (United States)

    Li, Hui; Shen, Yi-Ze

    2017-07-01

    Azimuth electromagnetic wave is a new type of electromagnetic prospecting technology. It can detect weak electromagnetic wave signal and realize real-time formation conductivity imaging. For effectively optimizing measurement accuracy of azimuth electromagnetic wave imaging tool, the efficient numerical simulation algorithm is required. In this paper, self-adaptive finite element method (FEM) has been used to investigate the azimuth electromagnetic wave logging tool response by adjusting antenna array system in different geological conditions. Numerical simulation examples show the accuracy and efficiency of the method, and provide physical interpretation of amplitude attenuation and phase shift of electromagnetic wave signal. Meanwhile, the high-accuracy numerical simulation results have great value to azimuth electromagnetic wave imaging tool calibration and data interpretation.

  13. Radial modal dependence of the azimuthal spectrum after parametric down-conversion

    CSIR Research Space (South Africa)

    Zhang, Y

    2014-01-01

    Full Text Available The radial degrees of freedom of the biphoton states that are produced in spontaneous parametric down-conversion (SPDC) in the Laguerre-Gaussian (LG) basis are investigated, theoretically and experimentally. We calculated the theoretical azimuthal...

  14. Dijet azimuthal decorrelations in pp collisions at √s=7 TeV.

    Science.gov (United States)

    Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Fabjan, C; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hartl, C; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kiesenhofer, W; Krammer, M; Liko, D; Mikulec, I; Pernicka, M; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Teischinger, F; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Benucci, L; Cerny, K; De Wolf, E A; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Roland, B; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Beauceron, S; Blekman, F; Blyweert, S; D'Hondt, J; Devroede, O; Gonzalez Suarez, R; Kalogeropoulos, A; Maes, J; Maes, M; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Gay, A P R; Hammad, G H; Hreus, T; Marage, P E; Thomas, L; Vander Velde, C; Vanlaer, P; Wickens, J; Adler, V; Costantini, S; Grunewald, M; Klein, B; Marinov, A; Mccartin, J; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Walsh, S; Zaganidis, N; Basegmez, S; Bruno, G; Caudron, J; Ceard, L; De Favereau De Jeneret, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Hollar, J; Lemaitre, V; Liao, J; Militaru, O; Ovyn, S; Pagano, D; Pin, A; Piotrzkowski, K; Schul, N; Beliy, N; Caebergs, T; Daubie, E; Alves, G A; De Jesus Damiao, D; Pol, M E; Souza, M H G; Carvalho, W; Da Costa, E M; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Nogima, H; Oguri, V; Prado Da Silva, W L; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Dias, F A; Dias, M A F; Fernandez Perez Tomei, T R; Gregores, E M; Marinho, F; Novaes, S F; Padula, Sandra S; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Tcholakov, V; Trayanov, R; Vankov, I; Dyulendarova, M; Hadjiiska, R; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Jiang, C H; Liang, D; Liang, S; Wang, J; Wang, J; Wang, X; Wang, Z; Xu, M; Yang, M; Zang, J; Zhang, Z; Ban, Y; Guo, S; Guo, Y; Li, W; Mao, Y; Qian, S J; Teng, H; Zhang, L; Zhu, B; Zou, W; Cabrera, A; Gomez Moreno, B; Ocampo Rios, A A; Osorio Oliveros, A F; Sanabria, J C; Godinovic, N; Lelas, D; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Attikis, A; Galanti, M; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Assran, Y; Mahmoud, M A; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Azzolini, V; Eerola, P; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Ungaro, D; Wendland, L; Banzuzi, K; Korpela, A; Tuuva, T; Sillou, D; Besancon, M; Choudhury, S; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Shreyber, I; Titov, M; Verrecchia, P; Baffioni, S; Beaudette, F; Bianchini, L; Bluj, M; Broutin, C; Busson, P; Charlot, C; Dahms, T; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Mironov, C; Ochando, C; Paganini, P; Sabes, D; Salerno, R; Sirois, Y; Thiebaux, C; Wyslouch, B; Zabi, A; Agram, J-L; Andrea, J; Besson, A; Bloch, D; Bodin, D; Brom, J-M; Cardaci, M; Chabert, E C; Collard, C; Conte, E; Drouhin, F; Ferro, C; Fontaine, J-C; Gelé, D; Goerlach, U; Greder, S; Juillot, P; Karim, M; Le Bihan, A-C; Mikami, Y; Van Hove, P; Fassi, F; Mercier, D; Baty, C; Beaupere, N; Bedjidian, M; Bondu, O; Boudoul, G; Boumediene, D; Brun, H; Chanon, N; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Falkiewicz, A; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Mirabito, L; Perries, S; Sordini, V; Tosi, S; Tschudi, Y; Verdier, P; Xiao, H; Megrelidze, L; Roinishvili, V; Lomidze, D; Anagnostou, G; Edelhoff, M; Feld, L; Heracleous, N; Hindrichs, O; Jussen, R; Klein, K; Merz, J; Mohr, N; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Sprenger, D; Weber, H; Weber, M; Wittmer, B; Ata, M; Bender, W; Erdmann, M; Frangenheim, J; Hebbeker, T; Hinzmann, A; Hoepfner, K; Hof, C; Klimkovich, T; Klingebiel, D; Kreuzer, P; Lanske, D; Magass, C; Masetti, G; Merschmeyer, M; Meyer, A; Papacz, P; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Steggemann, J; Teyssier, D; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Haj Ahmad, W; Heydhausen, D; Kress, T; Kuessel, Y; Linn, A; Nowack, A; Perchalla, L; Pooth, O; Rennefeld, J; Sauerland, P; Stahl, A; Thomas, M; Tornier, D; Zoeller, M H; Aldaya Martin, M

    2011-03-25

    Measurements of dijet azimuthal decorrelations in pp collisions at √s=7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 pb⁻¹. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.

  15. Microdrilling in steel using ultrashort pulsed laser beams with radial and azimuthal polarization.

    Science.gov (United States)

    Kraus, Martin; Ahmed, Marwan Abdou; Michalowski, Andreas; Voss, Andreas; Weber, Rudolf; Graf, Thomas

    2010-10-11

    A linear to radial and/or azimuthal polarization converter (LRAC) has been inserted into the beam delivery of a micromachining station equipped with a picosecond laser system. Percussion drilling and helical drilling in steel have been performed using radially as well as azimuthally polarized infrared radiation at 1030 nm. The presented machining results are discussed on the basis of numerical simulations of the polarization-dependent beam propagation inside the fabricated capillaries.

  16. Dijet Azimuthal Decorrelations in pp Collisions at sqrt(s) = 7 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, Vardan [Yerevan Physics Inst. (Armenia); et al.

    2011-03-01

    Measurements of dijet azimuthal decorrelations in pp collisions at sqrt(s) = 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 inverse picobarns. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.

  17. Azimuthal correlations of high-transverse-momentum pi /sup 0/ pairs

    CERN Document Server

    Cobb, J H; Filippas-Tassos, A; Fowler, E C; Goldberg, M; Horwitz, N; Iwata, S; Kourkoumelis, C; Lankford, A J; Mannelli, I; Moneti, G C; Mouzourakis, P; Nakamura, K; Nappi, A; Palmer, R B; Rahm, David Charles; Rehak, R; Resvanis, L K; Struczinski, W; Stumer, I; Willis, W J

    1978-01-01

    The authors have studied correlations between two pi /sup 0/s produced at the CERN intersecting storage rings, utilizing detectors with large azimuthal acceptance. It is found that the previously observed enhancement of two pi /sup 0/s produced at azimuthal difference near 180 degrees can be made to vanish when certain kinematic effects are removed. However, it is observed that aligned configurations above 8 GeV of transverse energy are unexplained by such kinematic effects. (9 refs).

  18. Dijet Azimuthal Decorrelations in pp Collisions at $\\sqrt{s}$ = 7 TeV

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Haensel, Stephan; Hartl, Christian; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kasieczka, Gregor; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Teischinger, Florian; Wagner, Philipp; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Benucci, Leonardo; Cerny, Karel; De Wolf, Eddi A.; Janssen, Xavier; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Beauceron, Stephanie; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Devroede, Olivier; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Joris; Maes, Michael; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Adler, Volker; Costantini, Silvia; Grunewald, Martin; Klein, Benjamin; Marinov, Andrey; Mccartin, Joseph; Ryckbosch, Dirk; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Caudron, Julien; Ceard, Ludivine; De Favereau De Jeneret, Jerome; Delaere, Christophe; Demin, Pavel; Favart, Denis; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Ovyn, Severine; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; De Jesus Damiao, Dilson; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Carvalho, Wagner; Da Costa, Eliza Melo; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Sznajder, Andre; De Almeida Dias, Flavia; Ferreira Dias, Marco Andre; Tomei, Thiago; De Moraes Gregores, Eduardo; Da Cunha Marinho, Franciole; Novaes, Sergio F.; Padula, Sandra; Darmenov, Nikolay; Dimitrov, Lubomir; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vankov, Ivan; Dyulendarova, Milena; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Marinova, Evelina; Mateev, Matey; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xu, Ming; Yang, Min; Zang, Jingjing; Zhang, Zhen; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Zhang, Linlin; Zhu, Bo; Zou, Wei; Cabrera, Andrés; Gomez Moreno, Bernardo; Ocampo Rios, Alberto Andres; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Lelas, Karlo; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A.; Rykaczewski, Hans; Assran, Yasser; Mahmoud, Mohammed; Hektor, Andi; Kadastik, Mario; Kannike, Kristjan; Müntel, Mait; Raidal, Martti; Rebane, Liis; Azzolini, Virginia; Eerola, Paula; Czellar, Sandor; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Klem, Jukka; Kortelainen, Matti J.; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Gentit, François-Xavier; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Marionneau, Matthieu; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Verrecchia, Patrice; Baffioni, Stephanie; Beaudette, Florian; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dobrzynski, Ludwik; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Thiebaux, Christophe; Wyslouch, Bolek; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Besson, Auguste; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Greder, Sebastien; Juillot, Pierre; Karim, Mehdi; Le Bihan, Anne-Catherine; Mikami, Yoshinari; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Baty, Clement; Beaupere, Nicolas; Bedjidian, Marc; Bondu, Olivier; Boudoul, Gaelle; Boumediene, Djamel; Brun, Hugues; Chanon, Nicolas; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Falkiewicz, Anna; Fay, Jean; Gascon, Susan; Ille, Bernard; Kurca, Tibor; Le Grand, Thomas; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Xiao, Hong; Megrelidze, Luka; Roinishvili, Vladimir; Lomidze, David; Anagnostou, Georgios; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Mohr, Niklas; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Weber, Martin; Wittmer, Bruno; Ata, Metin; Bender, Walter; Erdmann, Martin; Frangenheim, Jens; Hebbeker, Thomas; Hinzmann, Andreas; Hoepfner, Kerstin; Hof, Carsten; Klimkovich, Tatsiana; Klingebiel, Dennis; Kreuzer, Peter; Lanske, Dankfried; Magass, Carsten; Masetti, Gianni; Merschmeyer, Markus; Meyer, Arnd; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Bontenackels, Michael; Davids, Martina; Duda, Markus; Flügge, Günter; Geenen, Heiko; Giffels, Manuel; Haj Ahmad, Wael; Heydhausen, Dirk; Kress, Thomas; Kuessel, Yvonne; Linn, Alexander; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Thomas, Maarten; Tornier, Daiske; Zoeller, Marc Henning; Aldaya Martin, Maria; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Borras, Kerstin; Cakir, Altan; Campbell, Alan; Castro, Elena; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Flossdorf, Alexander; Flucke, Gero; Geiser, Achim; Glushkov, Ivan; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katkov, Igor; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Mankel, Rainer; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Olzem, Jan; Parenti, Andrea; Raspereza, Alexei; Raval, Amita; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Stein, Matthias; Tomaszewska, Justyna; Volyanskyy, Dmytro; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Gebbert, Ulla; Kaschube, Kolja; Kaussen, Gordon; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Naumann-Emme, Sebastian; Nowak, Friederike; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schröder, Matthias; Schum, Torben; Schwandt, Joern; Srivastava, Ajay Kumar; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Wolf, Roger; Barth, Christian; Bauer, Julia; Buege, Volker; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Feindt, Michael; Gruschke, Jasmin; Hackstein, Christoph; Hartmann, Frank; Heindl, Stefan Michael; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Kuhr, Thomas; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Peiffer, Thomas; Piparo, Danilo; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Renz, Manuel; Saout, Christophe; Scheurer, Armin; Schieferdecker, Philipp; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Wagner-Kuhr, Jeannine; Zeise, Manuel; Zhukov, Valery; Ziebarth, Eva Barbara; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Petrakou, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Triantis, Frixos A.; Aranyi, Attila; Bencze, Gyorgy; Boldizsar, Laszlo; Debreczeni, Gergely; Hajdu, Csaba; Horvath, Dezso; Kapusi, Anita; Krajczar, Krisztian; Laszlo, Andras; Sikler, Ferenc; Vesztergombi, Gyorgy; Beni, Noemi; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Veszpremi, Viktor; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Jindal, Monika; Kaur, Manjit; Kohli, Jatinder Mohan; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Anil; Singh, Jas Bir; Singh, Supreet Pal; Ahuja, Sudha; Bhattacharya, Satyaki; Choudhary, Brajesh C.; Gupta, Pooja; Jain, Sandhya; Jain, Shilpi; Kumar, Ashok; Shivpuri, Ram Krishen; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kataria, Sushil Kumar; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Devdatta; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Saha, Anirban; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Mondal, Naba Kumar; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Dimitrov, Anton; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Manna, Norman; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pierro, Giuseppe Antonio; Pompili, Alexis; Pugliese, Gabriella; Romano, Francesco; Roselli, Giuseppe; Selvaggi, Giovanna; Silvestris, Lucia; Trentadue, Raffaello; Tupputi, Salvatore; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Giunta, Marina; Marcellini, Stefano; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Genta, Chiara; Gonzi, Sandro; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Ghezzi, Alessio; Malberti, Martina; Malvezzi, Sandra; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Tancini, Valentina; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cimmino, Anna; De Cosa, Annapaola; De Gruttola, Michele; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Merola, Mario; Noli, Pasquale; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; De Mattia, Marco; Dorigo, Tommaso; Gasparini, Fabrizio; Gasparini, Ugo; Giubilato, Piero; Gonella, Franco; Gresele, Ambra; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Mazzucato, Mirco; Meneguzzo, Anna Teresa; Nespolo, Massimo; Perrozzi, Luca; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Triossi, Andrea; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Baesso, Paolo; Berzano, Umberto; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Viviani, Claudio; Biasini, Maurizio; Bilei, Gian Mario; Caponeri, Benedetta; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Santocchia, Attilio; Servoli, Leonello; Taroni, Silvia; Valdata, Marisa; Volpe, Roberta; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Palmonari, Francesco; Sarkar, Subir; Segneri, Gabriele; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Di Marco, Emanuele; Diemoz, Marcella; Franci, Daniele; Grassi, Marco; Longo, Egidio; Organtini, Giovanni; Palma, Alessandro; Pandolfi, Francesco; Paramatti, Riccardo; Rahatlou, Shahram; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Castello, Roberto; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Marone, Matteo; Maselli, Silvia; Migliore, Ernesto; Mila, Giorgia; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Trocino, Daniele; Vilela Pereira, Antonio; Belforte, Stefano; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Montanino, Damiana; Penzo, Aldo; Heo, Seong Gu; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kong, Dae Jung; Park, Hyangkyu; Son, Dohhee; Son, Dong-Chul; Kim, Jaeho; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Ji Hyun; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Rhee, Han-Bum; Seo, Eunsung; Shin, Seungsu; Sim, Kwang Souk; Choi, Minkyoo; Kang, Seokon; Kim, Hyunyong; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Martisiute, Dalia; Petrov, Pavel; Sabonis, Tomas; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Lopez-Fernandez, Ricardo; Sanchez-Hernandez, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A.; Allfrey, Philip; Krofcheck, David; Butler, Philip H.; Doesburg, Robert; Silverwood, Hamish; Ahmad, Muhammad; Ahmed, Ijaz; Asghar, Muhammad Irfan; Hoorani, Hafeez R.; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Sá Martins, Pedro; Musella, Pasquale; Nayak, Aruna; Ribeiro, Pedro Quinaz; Seixas, Joao; Silva, Pedro; Varela, Joao; Wöhri, Hermine Katharina; Belotelov, Ivan; Bunin, Pavel; Finger, Miroslav; Finger Jr., Michael; Golutvin, Igor; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Bondar, Nikolai; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Toropin, Alexander; Troitsky, Sergey; Epshteyn, Vladimir; Gavrilov, Vladimir; Kaftanov, Vitali; Kossov, Mikhail; Krokhotin, Andrey; Lychkovskaya, Natalia; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Rusakov, Sergey V.; Vinogradov, Alexey; Azhgirey, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Slabospitsky, Sergey; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cepeda, Maria; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M.; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Vizan Garcia, Jesus Manuel; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chamizo Llatas, Maria; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bell, Alan James; Benedetti, Daniele; Bernet, Colin; Bialas, Wojciech; Bloch, Philippe; Bocci, Andrea; Bolognesi, Sara; Breuker, Horst; Brona, Grzegorz; Bunkowski, Karol; Camporesi, Tiziano; Cano, Eric; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; Curé, Benoît; D'Enterria, David; De Roeck, Albert; Di Guida, Salvatore; Duarte Ramos, Fernando; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Gaddi, Andrea; Gennai, Simone; Georgiou, Georgios; Gerwig, Hubert; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Glege, Frank; Gomez-Reino Garrido, Robert; Gouzevitch, Maxime; Govoni, Pietro; Gowdy, Stephen; Guiducci, Luigi; Hansen, Magnus; Harvey, John; Hegeman, Jeroen; Hegner, Benedikt; Henderson, Conor; Hesketh, Gavin; Hoffmann, Hans Falk; Honma, Alan; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Lecoq, Paul; Lourenco, Carlos; Macpherson, Alick; Maki, Tuula; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Nesvold, Erik; Nguyen, Matthew; Orimoto, Toyoko; Orsini, Luciano; Perez, Emmanuelle; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Polese, Giovanni; Racz, Attila; Rodrigues Antunes, Joao; Rolandi, Gigi; Rommerskirchen, Tanja; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sharma, Archana; Siegrist, Patrice; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Spiropulu, Maria; Stöckli, Fabian; Stoye, Markus; Tropea, Paola; Tsirou, Andromachi; Tsyganov, Andrey; Veres, Gabor Istvan; Vichoudis, Paschalis; Voutilainen, Mikko; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Starodumov, Andrei; Bortignon, Pierluigi; Caminada, Lea; Chen, Zhiling; Cittolin, Sergio; Dissertori, Günther; Dittmar, Michael; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hervé, Alain; Hintz, Wieland; Lecomte, Pierre; Lustermann, Werner; Marchica, Carmelo; Martinez Ruiz del Arbol, Pablo; Meridiani, Paolo; Milenovic, Predrag; Moortgat, Filip; Nef, Pascal; Nessi-Tedaldi, Francesca; Pape, Luc; Pauss, Felicitas; Punz, Thomas; Rizzi, Andrea; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Sawley, Marie-Christine; Stieger, Benjamin; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Matthias; Wehrli, Lukas; Weng, Joanna; Aguiló, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Regenfus, Christian; Robmann, Peter; Schmidt, Alexander; Snoek, Hella; Chang, Yuan-Hann; Chen, Kuan-Hsin; Chen, Wan-Ting; Dutta, Suchandra; Go, Apollo; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Ming-Hsiung; Liu, Zong-Kai; Lu, Yun-Ju; Mekterovic, Darko; Wu, Jing-Han; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wang, Minzu; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karaman, Turker; Kayis Topaksu, Aysel; Nart, Alisah; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Tali, Bayram; Topakli, Huseyin; Uzun, Dilber; Vergili, Latife Nukhet; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yildirim, Eda; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Demir, Durmus; Gülmez, Erhan; Halu, Arda; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Levchuk, Leonid; Bell, Peter; Bostock, Francis; Brooke, James John; Cheng, Teh Lee; Clement, Emyr; Cussans, David; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Hansen, Maria; Hartley, Dominic; Heath, Greg P.; Heath, Helen F.; Huckvale, Benedickt; Jackson, James; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M.; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J.; Ward, Simon; Basso, Lorenzo; Bell, Ken W.; Belyaev, Alexander; Brew, Christopher; Brown, Robert M.; Camanzi, Barbara; Cockerill, David J.A.; Coughlan, John A.; Harder, Kristian; Harper, Sam; Kennedy, Bruce W.; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R.; Womersley, William John; Worm, Steven; Bainbridge, Robert; Ball, Gordon; Ballin, Jamie; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Davies, Gavin; Della Negra, Michel; Fulcher, Jonathan; Futyan, David; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Karapostoli, Georgia; Lyons, Louis; Magnan, Anne-Marie; Marrouche, Jad; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rompotis, Nikolaos; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Tapper, Alexander; Tourneur, Stephane; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardrope, David; Whyntie, Tom; Barrett, Matthew; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R.; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Teodorescu, Liliana; Hatakeyama, Kenichi; Bose, Tulika; Carrera Jarrin, Edgar; Clough, Andrew; Fantasia, Cory; Heister, Arno; St. John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Avetisyan, Aram; Bhattacharya, Saptaparna; Chou, John Paul; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Landsberg, Greg; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Speer, Thomas; Tsang, Ka Vang; Borgia, Maria Assunta; Breedon, Richard; Calderon De La Barca Sanchez, Manuel; Cebra, Daniel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Friis, Evan; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Liu, Haidong; Maruyama, Sho; Miceli, Tia; Nikolic, Milan; Pellett, Dave; Robles, Jorge; Salur, Sevil; Schwarz, Thomas; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Veelken, Christian; Andreev, Valeri; Arisaka, Katsushi; Cline, David; Cousins, Robert; Deisher, Amanda; Duris, Joseph; Erhan, Samim; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Jarvis, Chad; Plager, Charles; Rakness, Gregory; Schlein, Peter; Tucker, Jordan; Valuev, Vyacheslav; Babb, John; Clare, Robert; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Jeng, Geng-Yuan; Kao, Shih-Chuan; Liu, Feng; Liu, Hongliang; Luthra, Arun; Nguyen, Harold; Pasztor, Gabriella; Satpathy, Asish; Shen, Benjamin C.; Stringer, Robert; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G.; Cerati, Giuseppe Benedetto; Dusinberre, Elizabeth; Evans, David; Golf, Frank; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Mangano, Boris; Muelmenstaedt, Johannes; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pi, Haifeng; Pieri, Marco; Ranieri, Riccardo; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tu, Yanjun; Vartak, Adish; Würthwein, Frank; Yagil, Avraham; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Koay, Sue Ann; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Mccoll, Nickolas; Pavlunin, Viktor; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; Vlimant, Jean-Roch; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Gataullin, Marat; Kcira, Dorian; Litvine, Vladimir; Ma, Yousi; Mott, Alexander; Newman, Harvey B.; Rogan, Christopher; Timciuc, Vladlen; Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Jun, Soon Yung; Liu, Yueh-Feng; Paulini, Manfred; Russ, James; Terentyev, Nikolay; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Dinardo, Mauro Emanuele; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T.; Gaz, Alessandro; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Zang, Shi-Lei; Agostino, Lorenzo; Alexander, James; Chatterjee, Avishek; Das, Souvik; Eggert, Nicholas; Fields, Laura Johanna; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Kuznetsov, Valentin; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Puigh, Darren; Riley, Daniel; Ryd, Anders; Shi, Xin; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Biselli, Angela; Cirino, Guy; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Atac, Muzaffer; Bakken, Jon Alan; Banerjee, Sunanda; Bauerdick, Lothar A.T.; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C.; Bloch, Ingo; Borcherding, Frederick; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Demarteau, Marcel; Eartly, David P.; Elvira, Victor Daniel; Esen, Selda; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Green, Dan; Gunthoti, Kranti; Gutsche, Oliver; Hahn, Alan; Hanlon, Jim; Harris, Robert M.; Hirschauer, James; Hooberman, Benjamin; James, Eric; Jensen, Hans; Johnson, Marvin; Joshi, Umesh; Khatiwada, Rakshya; Kilminster, Benjamin; Klima, Boaz; Kousouris, Konstantinos; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Limon, Peter; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Mason, David; McBride, Patricia; McCauley, Thomas; Miao, Ting; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Popescu, Sorina; Pordes, Ruth; Prokofyev, Oleg; Saoulidou, Niki; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J.; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D.; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Goldberg, Sean; Kim, Bockjoo; Klimenko, Sergey; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Matchev, Konstantin; Mitselmakher, Guenakh; Muniz, Lana; Pakhotin, Yuriy; Prescott, Craig; Remington, Ronald; Schmitt, Michael; Scurlock, Bobby; Sellers, Paul; Skhirtladze, Nikoloz; Wang, Dayong; Yelton, John; Zakaria, Mohammed; Ceron, Cristobal; Gaultney, Vanessa; Kramer, Laird; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bandurin, Dmitry; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F.; Prosper, Harrison; Quertenmont, Loic; Sekmen, Sezen; Veeraraghavan, Venkatesh; Baarmand, Marc M.; Dorney, Brian; Guragain, Samir; Hohlmann, Marcus; Kalakhety, Himali; Ralich, Robert; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Garcia-Solis, Edmundo Javier; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silvestre, Catherine; Smoron, Agata; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Cankocak, Kerem; Clarida, Warren; Duru, Firdevs; Lae, Chung Khim; McCliment, Edward; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bonato, Alessio; Eskew, Christopher; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Tran, Nhan Viet; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Murray, Michael; Noonan, Daniel; Radicci, Valeria; Sanders, Stephen; Wood, Jeffrey Scott; Zhukova, Victoria; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Wan, Zongru; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Eno, Sarah Catherine; Ferencek, Dinko; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G.; Kirn, Malina; Lu, Ying; Mignerey, Alice; Rossato, Kenneth; Rumerio, Paolo; Santanastasio, Francesco; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C.; Twedt, Elizabeth; Alver, Burak; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Everaerts, Pieter; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Harris, Philip; Kim, Yongsun; Klute, Markus; Lee, Yen-Jie; Li, Wei; Loizides, Constantinos; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Sumorok, Konstanty; Sung, Kevin; Wenger, Edward Allen; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cole, Perrie; Cooper, Seth; Cushman, Priscilla; Dahmes, Bryan; De Benedetti, Abraham; Dudero, Phillip Russell; Franzoni, Giovanni; Haupt, Jason; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Rekovic, Vladimir; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Cremaldi, Lucien Marcus; Godang, Romulus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Summers, Don; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R.; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kelly, Tony; Kravchenko, Ilya; Lazo-Flores, Jose; Lundstedt, Carl; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R.; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Boeriu, Oana; Chasco, Matthew; Reucroft, Steve; Swain, John; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Kolberg, Ted; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Warchol, Jadwiga; Wayne, Mitchell; Ziegler, Jill; Bylsma, Ben; Durkin, Lloyd Stanley; Gu, Jianhui; Hill, Christopher; Killewald, Phillip; Kotov, Khristian; Ling, Ta-Yung; Rodenburg, Marissa; Williams, Grayson; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hunt, Adam; Jones, John; Laird, Edward; Lopes Pegna, David; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E.; Bolla, Gino; Borrello, Laura; Bortoletto, Daniela; Everett, Adam; Garfinkel, Arthur F.; Gecse, Zoltan; Gutay, Laszlo; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Laasanen, Alvin T.; Leonardo, Nuno; Liu, Chang; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Jindal, Pratima; Parashar, Neeti; Boulahouache, Chaouki; Cuplov, Vesna; Ecklund, Karl Matthew; Geurts, Frank J.M.; Liu, Jinghua H.; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Flacher, Henning; Garcia-Bellido, Aran; Goldenzweig, Pablo; Gotra, Yury; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Orbaker, Douglas; Petrillo, Gianluca; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Yan, Ming; Atramentov, Oleksiy; Barker, Anthony; Duggan, Daniel; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hits, Dmitry; Lath, Amitabh; Panwalkar, Shruti; Patel, Rishi; Richards, Alan; Rose, Keith; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Asaadi, Jonathan; Eusebi, Ricardo; Gilmore, Jason; Gurrola, Alfredo; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Nguyen, Chi Nhan; Osipenkov, Ilya; Pivarski, James; Safonov, Alexei; Sengupta, Sinjini; Tatarinov, Aysen; Toback, David; Weinberger, Michael; Akchurin, Nural; Bardak, Cemile; Damgov, Jordan; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Mane, Poonam; Roh, Youn; Sill, Alan; Volobouev, Igor; Wigmans, Richard; Yazgan, Efe; Appelt, Eric; Brownson, Eric; Engh, Daniel; Florez, Carlos; Gabella, William; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Buehler, Marc; Conetti, Sergio; Cox, Bradley; Francis, Brian; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Lamichhane, Pramod; Mattson, Mark; Milstène, Caroline; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Bellinger, James Nugent; Carlsmith, Duncan; Dasu, Sridhara; Efron, Jonathan; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Loveless, Richard; Mohapatra, Ajit; Reeder, Don; Ross, Ian; Savin, Alexander; Smith, Wesley H.; Swanson, Joshua; Weinberg, Marc

    2011-01-01

    Measurements of dijet azimuthal decorrelations in pp collisions at sqrt(s) = 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 inverse picobarns. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.

  19. Study of the azimuthal asymmetry of jets in neutral current deep inelastic scattering at HERA

    CERN Document Server

    Chekanov, S; Magill, S; Musgrave, B; Repond, J; Yoshida, R; Mattingly, M C K; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Cifarelli, L; Cindolo, F; Contin, A; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Margotti, A; Nania, R; Palmonari, F; Pesci, A; Sartorelli, G; Zichichi, A; Aghuzumtsyan, G; Bartsch, D; Brock, I; Goers, S; Hartmann, H; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kind, O; Paul, E; Rautenberg, J; Renner, R; Schnurbusch, H; Stifutkin, A; Tandler, J; Voss, K C; Wang, M; Weber, A; Bailey, D S; Brook, N H; Cole, J E; Foster, B; Heath, G P; Heath, H F; Robins, S; Rodrigues, E; Scott, J; Tapper, R J; Wing, M; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Kim, J Y; Kim, Y K; Lee, J H; Lim, I T; Pac, M Y; Caldwell, A; Helbich, M; Liu, X; Mellado, B; Ning, Y; Paganis, S; Ren, Z; Schmidke, W B; Sciulli, F; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Olkiewicz, K; Stopa, P; Zawiejski, L; Adamczyk, L; Bold, T; Grabowska-Bold, I; Kisielewska, D; Kowal, A M; Kowal, M; Kowalski, T; Przybycien, M B; Suszycki, L; Szuba, D; Szuba, J; Kotanski, A; Slominski, W; Bauerdick, L A T; Behrens, U; Bloch, I; Borras, K; Chiochia, V; Dannheim, D; Derrick, M; Drews, G; Fourletova, J; Fox-Murphy, A; Fricke, U; Geiser, A; Göbel, F; Göttlicher, P; Gutsche, O; Haas, T; Hain, W; Hartner, G F; Hillert, S; Kötz, U; Kowalski, H; Kramberger, G; Labes, H; Lelas, D; Löhr, B; Mankel, R; Melzer-Pellmann, I A; Moritz, M; Notz, D; Petrucci, M C; Polini, A; Raval, A; Schneekloth, U; Selonke, F; Wessoleck, H; Wichmann, R; Wolf, G; Youngman, C; Zeuner, W; Lopez-Duran Viani, A; Meyer, A; Schlenstedt, S; Barbagli, G; Gallo, E; Genta, C; Pelfer, P G; Bamberger, A; Benen, A; Coppola, N; Bell, M; Bussey, P J; Doyle, A T; Glasman, C; Hanlon, S; Lee, S W; Lupi, A; McCance, G J; Saxon, D H; Skillicorn, I O; Gialas, I; Bodmann, B; Carli, T; Holm, U; Klimek, K; Krumnack, N; Lohrmann, E; Milite, M; Salehi, H; Stonjek, S; Wick, K; Ziegler, A; Collins-Tooth, C; Foudas, C; Goncalo, R; Long, K R; Metlica, F; Tapper, A D; Cloth, P; Filges, D; Kuze, M; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Barakbaev, A N; Boos, E G; Pokrovskiy, N S; Zhautykov, B O; Lim, H; Son, D; Barreiro, F; González, O; Labarga, L; Del Peso, J; Redondo, I; Tassi, E; Terron, J; Vázquez, M; Barbi, M; Bertolin, A; Corriveau, F; Ochs, A; Padhi, S; Stairs, D G; Saint-Laurent, M G; Tsurugai, T; Antonov, A; Danilov, P; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V V; Suchkov, S; Dementiev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korzhavina, I A; Kuzmin, V A; Levchenko, B B; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Vlasov, N N; Zotkin, S A; Bokel, C; Engelen, J; Grijpink, S; Koffeman, E; Kooijman, P; Maddox, E; Pellegrino, A; Schagen, S; Tiecke, H G; Tuning, N; Velthuis, J J; Wiggers, L; De Wolf, E; Brümmer, N; Bylsma, B; Durkin, L S; Ling, T Y; Boogert, S; Cooper-Sarkar, A M; Devenish, R C E; Ferrando, J; Grzelak, G; Matsushita, T; Rigby, M; Ruske, O; Sutton, M R; Walczak, R; Brugnera, R; Carlin, R; Dal Corso, F; Dusini, S; Garfagnini, A; Limentani, S; Longhin, A; Parenti, A; Posocco, M; Stanco, L; Turcato, M; Heaphy, E A; Oh, B Y; Saull, P R B; Whitmore, J J; Iga, Y; D'Agostini, G; Marini, G; Nigro, A; Cormack, C; Hart, J C; McCubbin, N A; Heusch, C; Park, I H; Pavel, N; Abramowicz, H; Gabareen, A; Kananov, S; Kreisel, A; Levy, A; Abe, T; Fusayasu, T; Kagawa, S; Kohno, T; Tawara, T; Yamashita, T; Hamatsu, R; Hirose, T; Inuzuka, M; Kitamura, S; Matsuzawa, K; Nishimura, T; Arneodo, M; Ferrero, M I; Monaco, V; Ruspa, M; Sacchi, R; Solano, A; Galea, R; Koop, T; Levman, G M; Martin, J F; Mirea, A; Sabetfakhri, A; Butterworth, J M; Gwenlan, C; Hall-Wilton, R; Jones, T W; Lightwood, M S; Loizides, J H; West, B J; Ciborowski, J; Ciesielski, R; Nowak, R J; Pawlak, J M; Smalska, B; Sztuk, J; Tymieniecka, T; Ukleja, A; Ukleja, J; Zarnecki, A F; Adamus, M; Plucinsky, P P; Eisenberg, Y; Gladilin, L K; Hochman, D; Karshon, U; Kcira, D; Lammers, S; Li, L; Reeder, D D; Savin, A A; Smith, W H; Deshpande, Abhay A; Dhawan, S; Hughes, V W; Straub, P B; Bhadra, S; Catterall, C D; Fourletov, S; Menary, S; Soares, M; Standage, J

    2003-01-01

    The azimuthal distribution of jets produced in the Breit frame in high-Q**2 deep inelastic e+p scattering has been studied with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. The measured azimuthal distribution shows a structure that is well described by next-to-leading-order QCD predictions over the Q**2 range considered, Q**2>125 GeV**2.

  20. Effect of thermo-mechanical cycling on zirconium hydride reorientation studied in situ with synchrotron X-ray diffraction

    Science.gov (United States)

    Colas, Kimberly B.; Motta, Arthur T.; Daymond, Mark R.; Almer, Jonathan D.

    2013-09-01

    The circumferential hydrides normally present in nuclear reactor fuel cladding after reactor exposure may dissolve during drying for dry storage and re-precipitate when cooled under load into a more radial orientation, which could embrittle the fuel cladding. It is necessary to study the rates and conditions under which hydride reorientation may happen in order to assess fuel integrity in dry storage. The objective of this work is to study the effect of applied stress and thermal cycling on the hydride morphology in cold-worked stress-relieved Zircaloy-4 by combining conventional metallography and in situ X-ray diffraction techniques. Metallography is used to study the evolution of hydride morphology after several thermo-mechanical cycles. In situ X-ray diffraction performed at the Advanced Photon Source synchrotron provides real-time information on the process of hydride dissolution and precipitation under stress during several thermal cycles. The detailed study of diffracted intensity, peak position and full-width at half-maximum provides information on precipitation kinetics, elastic strains and other characteristics of the hydride precipitation process. The results show that thermo-mechanical cycling significantly increases the radial hydride fraction as well as the hydride length and connectivity. The radial hydrides are observed to precipitate at a lower temperature than circumferential hydrides. Variations in the magnitude and range of hydride strains due to reorientation and cycling have also been observed. These results are discussed in light of existing models and experiments on hydride reorientation. The study of hydride elastic strains during precipitation shows marked differences between circumferential and radial hydrides, which can be used to investigate the reorientation process. Cycling under stress above the threshold stress for reorientation drastically increases both the reoriented hydride fraction and the hydride size. The reoriented hydride

  1. Distinguishing the nonjet azimuth quadrupole from QCD jets and hydrodynamic flows via 2D angular correlations and quadrupole spectrum analysis

    CERN Document Server

    Trainor, Thomas A

    2016-01-01

    According to the flow narrative commonly applied to high-energy nuclear collisions a 1D cylindrical-quadrupole component of 2D angular correlations conventionally denoted by quantity $v_2$ is interpreted to represent elliptic flow: azimuth modulation of transverse or radial flow in noncentral nucleus-nucleus (A-A) collisions. The nonjet (NJ) quadrupole component exhibits various properties inconsistent with a flow or hydro interpretation, including the observation that NJ-quadrupole centrality variation in $A$-$A$ collisions has no relation to strongly-varying jet modification ("jet quenching") in those collisions commonly attributed to jet interaction with a dense flowing medium. In the present study I report isolation of quadrupole spectra from $p_t$-differential $v_2(p_t)$ data obtained at the relativistic heavy ion collider (RHIC) and large hadron collider (LHCr). I demonstrate that NJ quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole...

  2. Optimal Full Waveform Inversion Strategy in Azimuthally Rotated Elastic Orthorhombic Media

    KAUST Repository

    Oh, Juwon

    2017-05-26

    The elastic orthorhombic assumption is one of the most practical Earth models that takes into account the horizontal anisotropic layering and vertical fracture network. In this model, the rotation angle of the vertical planes of symmetry is a crucial parameter needed to increase the convergence of an anisotropic full waveform inversion (FWI) as well as to provide the fracture geometry along azimuthal direction. As an initial step, we investigate the possibility of recovering the azimuth angle via FWI, which may offer high-resolution information. We first utilize our new parameterization with deviation parameters, which provides the opportunity for multi-stage FWI. Based on the radiation patterns and gradient directions of each parameter, we show that the azimuth angle mainly affects the parameters that have azimuth-dependent radiation patterns, so that we can hierarchically build up the subsurface model from isotropic to VTI to azimuthally rotated orthorhombic models with less trade-offs. From the numerical example for a synthetic 3D model, we expect that both a deviation parameter and the azimuth angle can be recovered in the last stage of FWI with minimum trade-offs.

  3. FEASIBILITY OF RECYCLING PLUTONIUM AND MINOR ACTINIDES IN LIGHT WATER REACTORS USING HYDRIDE FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Greenspan, Ehud; Todreas, Neil; Taiwo, Temitope

    2009-03-10

    The objective of this DOE NERI program sponsored project was to assess the feasibility of improving the plutonium (Pu) and minor actinide (MA) recycling capabilities of pressurized water reactors (PWRs) by using hydride instead of oxide fuels. There are four general parts to this assessment: 1) Identifying promising hydride fuel assembly designs for recycling Pu and MAs in PWRs 2) Performing a comprehensive systems analysis that compares the fuel cycle characteristics of Pu and MA recycling in PWRs using the promising hydride fuel assembly designs identified in Part 1 versus using oxide fuel assembly designs 3) Conducting a safety analysis to assess the likelihood of licensing hydride fuel assembly designs 4) Assessing the compatibility of hydride fuel with cladding materials and water under typical PWR operating conditions Hydride fuel was found to offer promising transmutation characteristics and is recommended for further examination as a possible preferred option for recycling plutonium in PWRs.

  4. Heat transfer analysis of metal hydrides in metal-hydrogen secondary batteries

    Science.gov (United States)

    Onischak, M.; Dharia, D.; Gidaspow, D.

    1976-01-01

    The heat transfer between a metal-hydrogen secondary battery and a hydrogen-storing metal hydride was studied. Temperature profiles of the endothermic metal hydrides and the metal-hydrogen battery were obtained during discharging of the batteries assuming an adiabatic system. Two hydride materials were considered in two physical arrangements within the battery system. In one case the hydride is positioned in a thin annular region about the battery stack; in the other the hydride is held in a tube down the center of the stack. The results show that for a typical 20 ampere-hour battery system with lanthanum pentanickel hydride as the hydrogen reservoir the system could perform successfully.

  5. Molecular early main group metal hydrides: synthetic challenge, structures and applications.

    Science.gov (United States)

    Harder, Sjoerd

    2012-11-25

    Within the general area of early main group metal chemistry, the controlled synthesis of well-defined metal hydride complexes is a rapidly developing research field. As group 1 and 2 metal complexes are generally highly dynamic and lattice energies for their [MH](∞) and [MH(2)](∞) salts are high, the synthesis of well-defined soluble hydride complexes is an obvious challenge. Access to molecular early main group metal hydrides, however, is rewarding: these hydrocarbon-soluble metal hydrides are highly reactive, have found use in early main group metal catalysis and are potentially also valuable molecular model systems for polar metal hydrides as a hydrogen storage material. The article focusses specifically on alkali and alkaline-earth metal hydride complexes and discusses the synthetic challenge, molecular structures, reactivity and applications.

  6. Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kjell-Tore

    1996-08-01

    Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

  7. Orbital-like motion of hydride ligands around low-coordinate metal centers.

    Science.gov (United States)

    Ortuño, Manuel A; Vidossich, Pietro; Conejero, Salvador; Lledós, Agustí

    2014-12-15

    Hydrogen atoms in the coordination sphere of a transition metal are highly mobile ligands. Here, a new type of dynamic process involving hydrides has been characterized by computational means. This dynamic event consists of an orbital-like motion of hydride ligands around low-coordinate metal centers containing N-heterocyclic carbenes. The hydride movement around the carbene-metal-carbene axis is the lowest energy mode connecting energy equivalent isomers. This understanding provides crucial information for the interpretation of NMR spectra.

  8. High Temperature Metal Hydrides as Heat Storage Materials for Solar and Related Applications

    Directory of Open Access Journals (Sweden)

    Borislav Bogdanović

    2009-01-01

    Full Text Available For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 °C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described.

  9. High temperature metal hydrides as heat storage materials for solar and related applications.

    Science.gov (United States)

    Felderhoff, Michael; Bogdanović, Borislav

    2009-01-01

    For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 degrees C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described.

  10. Neutral binuclear rare-earth metal complexes with four μ₂-bridging hydrides.

    Science.gov (United States)

    Rong, Weifeng; He, Dongliang; Wang, Meiyan; Mou, Zehuai; Cheng, Jianhua; Yao, Changguang; Li, Shihui; Trifonov, Alexander A; Lyubov, Dmitrii M; Cui, Dongmei

    2015-03-25

    The first neutral rare-earth metal dinuclear dihydrido complexes [(NPNPN)LnH2]2 (2-Ln; Ln = Y, Lu; NPNPN: N[Ph2PNC6H3((i)Pr)2]2) bearing μ2-bridging hydride ligands have been synthesized. In the presence of THF, 2-Y undergoes intramolecular activation of the sp(2) C-H bond to form dinuclear aryl-hydride complex 3-Y containing three μ2-bridging hydride ligands.

  11. Development of a novel metal hydride-air secondary battery

    Energy Technology Data Exchange (ETDEWEB)

    Gamburzev, S.; Zhang, W.; Velev, O.A.; Srinivasan, S.; Appleby, A.J. [Texas A and M University, College Station (United States). Center for Electrochemical Systems and Hydrogen Research; Visintin, A. [Universidad Nacional de La Plata (Argentina). Insituto Nacional de Investigaciones Fisicoquimica Teoricas y Applicadas

    1998-05-01

    A laboratory metal hydride/air cell was evaluated. Charging was via a bifunctional air gas-diffusion electrode. Mixed nickel and cobalt oxides, supported on carbon black and activated carbon, were used as catalysts in this electrode. At 30 mA cm{sup -2} in 6 M KOH, the air electrode potentials were -0.2 V (oxygen reduction) and +0.65 V (oxygen evolution) vs Hg/HgO. The laboratory cell was cycled for 50 cycles at the C/2 rate (10 mA cm{sup -2}). The average discharge/charge voltages of the cell were 0.65 and 1.6 V, respectively. The initial capacity of the metal hydride electrode decreased by about 15% after 50 cycles. (author)

  12. Detecting low concentrations of plutonium hydride with magnetization measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Wook; Mun, E. D.; Baiardo, J. P.; Zapf, V. S.; Mielke, C. H. [National High Magnetic Field Laboratory, MPA-CMMS, Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545 (United States); Smith, A. I.; Richmond, S.; Mitchell, J.; Schwartz, D. [Nuclear Material Science Group, MST-16, LANL, Los Alamos, New Mexico 87545 (United States)

    2015-02-07

    We report the formation of plutonium hydride in 2 at. % Ga-stabilized δ-Pu, with 1 at. % H charging. We show that magnetization measurements are a sensitive, quantitative measure of ferromagnetic plutonium hydride against the nonmagnetic background of plutonium. It was previously shown that at low hydrogen concentrations, hydrogen forms super-abundant vacancy complexes with plutonium, resulting in a bulk lattice contraction. Here, we use magnetization, X-ray, and neutron diffraction measurements to show that in addition to forming vacancy complexes, at least 30% of the H atoms bond with Pu to precipitate PuH{sub x} on the surface of the sample with x ∼ 1.9. We observe magnetic hysteresis loops below 40 K with magnetic remanence, consistent with ferromagnetic PuH{sub 1.9}.

  13. Optical studies of neutron-irradiated lithium hydride single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Oparin, D.V.; Pilipenko, G.I.; Tyutyunnik, O.I.; Gavrilov, F.F.; Sulimov, E.M. (Ural' skij Politekhnicheskij Inst., Sverdlovsk (USSR))

    1984-09-01

    Lithium hydride single crystals irradiated with neutrons were studied by the optical method. Wide bands belonging to the large F-aggregate and quasimetallic F-centres and to the metallic lithium colloids were discovered in the absorption spectra at room temperature. The small Fsub(n)-centres and molecular lithium centres were detected at 77 K. From the electron-vibrational structure of the absorption spectra of these centres the energies of acoustic phonons in X, W, L points of the Brillouin zone of lithium hydride have been found out: TA(L)-235 cm/sup -1/, TA(X)-27g cm/sup -1/, TA(W)-327 cm/sup -1/, LA(W)-384 cm/sup -1/, LA(X)-426 cm/sup -1/.

  14. Hydrorefining distillates from coal liquefaction using intermetallic compound hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kadiev, Kh.M.; Pivovarova, N.A.; Askhabova, Kh.N.; Taramov, Kh.K.

    1986-07-01

    Investigations are discussed into hydrorefining of coal liquefaction distillate using ZrNi intermetallic compound hydride as catalyst. The paper shows that 70-75% reduction in content of unsaturated and sulfur-containing compounds takes place in the presence of this catalyst at low temperature (200-250 C) and pressure (0.1 MPa), and establishes that preliminary preparation of starting material (removal of phenols and nitrous bases) produces significant effect on hydrorefining results and product stability. Tests have also shown that although intermetallic compound hydride catalyst has fairly low stability, it is capable of recovering its catalytic properties on reduction-oxidation treatment. Description of the tests and characteristics of hydrorefining products of coal liquefaction distillate are given. 8 references.

  15. ALUMINUM HYDRIDE: A REVERSIBLE STORAGE MATERIAL FOR HYDROGEN STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Zidan, R; Christopher Fewox, C; Brenda Garcia-Diaz, B; Joshua Gray, J

    2009-01-09

    One of the challenges of implementing the hydrogen economy is finding a suitable solid H{sub 2} storage material. Aluminium (alane, AlH{sub 3}) hydride has been examined as a potential hydrogen storage material because of its high weight capacity, low discharge temperature, and volumetric density. Recycling the dehydride material has however precluded AlH{sub 3} from being implemented due to the large pressures required (>10{sup 5} bar H{sub 2} at 25 C) and the thermodynamic expense of chemical synthesis. A reversible cycle to form alane electrochemically using NaAlH{sub 4} in THF been successfully demonstrated. Alane is isolated as the triethylamine (TEA) adduct and converted to unsolvated alane by heating under vacuum. To complete the cycle, the starting alanate can be regenerated by direct hydrogenation of the dehydrided alane and the alkali hydride (NaH) This novel reversible cycle opens the door for alane to fuel the hydrogen economy.

  16. Irradiation effects on thermal properties of LWR hydride fuel

    Science.gov (United States)

    Terrani, Kurt; Balooch, Mehdi; Carpenter, David; Kohse, Gordon; Keiser, Dennis; Meyer, Mitchell; Olander, Donald

    2017-04-01

    Three hydride mini-fuel rods were fabricated and irradiated at the MIT nuclear reactor with a maximum burnup of 0.31% FIMA or ∼5 MWd/kgU equivalent oxide fuel burnup. Fuel rods consisted of uranium-zirconium hydride (U (30 wt%)ZrH1.6) pellets clad inside a LWR Zircaloy-2 tubing. The gap between the fuel and the cladding was filled with lead-bismuth eutectic alloy to eliminate the gas gap and the large temperature drop across it. Each mini-fuel rod was instrumented with two thermocouples with tips that are axially located halfway through the fuel centerline and cladding surface. In-pile temperature measurements enabled calculation of thermal conductivity in this fuel as a function of temperature and burnup. In-pile thermal conductivity at the beginning of test agreed well with out-of-pile measurements on unirradiated fuel and decreased rapidly with burnup.

  17. Pyrophoric behaviour of uranium hydride and uranium powders

    Energy Technology Data Exchange (ETDEWEB)

    Le Guyadec, F., E-mail: fabienne.leguyadec@cea.f [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Genin, X.; Bayle, J.P. [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Dugne, O. [DEN/DTEC/SGCS, 30207 Bagnols sur Ceze, BP 17171 (France); Duhart-Barone, A.; Ablitzer, C. [CEA Cadarache DEN/DEC/SPUA, 13108 St. Paul lez Durance (France)

    2010-01-31

    Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (<0.5 wt.%) was obtained by heat treatment at low temperature in flowing Ar/5%H{sub 2}. Pure uranium powder was obtained by dehydration in flowing pure argon. Those fine powders showed spontaneous ignition at room temperature in air. An in situ CCD-camera displayed ignition associated with powder temperature measurement. Characterization of powders before and after ignition was performed by XRD measurements and SEM observations. Oxidation mechanisms are proposed.

  18. Structural isotope effects in metal hydrides and deuterides.

    Science.gov (United States)

    Ting, Valeska P; Henry, Paul F; Kohlmann, Holger; Wilson, Chick C; Weller, Mark T

    2010-03-07

    Historically the extraction of high-quality crystallographic information from inorganic samples having high hydrogen contents, such as metal hydrides, has involved preparing deuterated samples prior to study using neutron powder diffraction. We demonstrate, through direct comparison of the crystal structure refinements of the binary hydrides SrH(2) and BaH(2) with their deuteride analogues at 2 K and as a function of temperature, that precise and accurate structural information can be obtained from rapid data collections from samples containing in excess of 60 at.% hydrogen using modern high-flux, medium resolution, continuous wavelength neutron powder diffraction instruments. Furthermore, observed isotope-effects in the extracted lattice parameters and atomic positions illustrate the importance of investigating compounds in their natural hydrogenous form whenever possible.

  19. Effects of metastability on hydrogen sorption in fluorine substituted hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Pinatel, E.R.; Corno, M.; Ugliengo, P.; Baricco, M., E-mail: marcello.baricco@unito.it

    2014-12-05

    Highlights: • Fluorine substitution in simple metal hydrides has been modelled. • The stability of the MH{sub (1−x)}F{sub x} solid solutions has been discussed. • Conditions for reversibility of sorption reactions have been suggested. - Abstract: In this work ab initio calculations and Calphad modelling have been coupled to describe the effect of fluorine substitution on the thermodynamics of hydrogenation–dehydrogenation in simple hydrides (NaH, AlH{sub 3} and CaH{sub 2}). These example systems have been used to discuss the conditions required for the formation of a stable hydride–fluoride solid solution necessary to obtain a reversible hydrogenation reaction.

  20. H{sub 2} thermal desorption and hydride conversion reactions in Li cells of TiH{sub 2}/C amorphous nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Vitucci, F.M., E-mail: francesco.vitucci@roma1.infn.it [CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma (Italy); Paolone, A. [CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma (Italy); Brutti, S. [CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma (Italy); Dipartimento di Scienze, Univ. Basilicata, V.le Ateneo Lucano, 10, 85100 Potenza (Italy); Munaò, D.; Silvestri, L.; Panero, S. [Dipartimento di Chimica, Sapienza Univ. Roma, P.le A. Moro 5, 00185 Roma (Italy); Reale, P. [ENEA – Centro Ricerche Casaccia,via Anguillarese 301, 00100 Roma (Italy)

    2015-10-05

    Highlights: • Galvanostatic measurements on amorphous TiH{sub 2} is reported. • Variation of ball milling pre-treatment vary the first discharge capacity. • Relation between thermal H{sub 2} desorption and electrochemical properties is proposed. - Abstract: Here we investigate the properties of amorphous TiH{sub 2}/carbon nanocomposites as possible active material in lithium cells. Several TiH{sub 2}/C mixtures are prepared by a mechanochemical route, by varying the carbon/hydride ratio. Materials are tested in electrochemical cells versus lithium metal in EC:DMC LiPF{sub 6} electrolyte by galvanostatic cycling (GC) and are characterized by X-ray diffraction, transmission electron microscopy, thermogravimetry and mass spectrometry. Thermal dehydrogenation processes are altered by the mechanochemical treatment of the sample: milling decreases the hydrogen content of the hydride. On the other hand, the mechanochemical grinding increases the specific capacity delivered during the first GC discharge. We suggest that the electrochemical process is the result of a delicate balance between the absolute quantity of hydrogen and its availability for the hydride conversion reaction.

  1. Shielding efficiency of metal hydrides and borohydrides in fusion reactors

    OpenAIRE

    Singh Vishvanath P.; Badiger Nagappa M.; Gerward Leif

    2016-01-01

    Mass attenuation coefficients, mean free paths and exposure buildup factors have been used to characterize the shielding efficiency of metal hydrides and borohydrides, with high density of hydrogen. Gamma ray exposure buildup factors were computed using five-parameter geometric progression fitting at energies 0.015 MeV to15 MeV, and for penetration depths up to 40 mean free paths. Fast-neutron shielding efficiency has been characterized by the effective neu...

  2. Photoelectron spectroscopic study of carbon aluminum hydride cluster anions

    Science.gov (United States)

    Zhang, Xinxing; Wang, Haopeng; Ganteför, Gerd; Eichhorn, Bryan W.; Kiran, Boggavarapu; Bowen, Kit H.

    2016-10-01

    Numerous previously unknown carbon aluminum hydride cluster anions were generated in the gas phase, identified by time-of-flight mass spectrometry and characterized by anion photoelectron spectroscopy, revealing their electronic structure. Density functional theory calculations on the CAl5-9H- and CAl5-7H2- found that several of them possess unusually high carbon atom coordination numbers. These cluster compositions have potential as the basis for new energetic materials.

  3. METHOD OF MAKING DELTA ZIRCONIUM HYDRIDE MONOLITHIC MODERATOR PIECES

    Science.gov (United States)

    Vetrano, J.B.

    1962-01-23

    A method is given for preparing large, sound bodies of delta zirconium hydride. The method includes the steps of heating a zirconium body to a temperature of not less than l000 deg C, providing a hydrogen atmosphere for the zirconium body at a pressure not greater than one atmosphere, reducing the temperature slowly to 800 deg C at such a rate that cracks do not form while maintaining the hydrogen pressure substantially constant, and cooling in an atmosphere of hydrogen. (AEC)

  4. Aluminum Hydride as a Fuel Supplement to NanoThermites

    Science.gov (United States)

    2014-01-01

    explosives and as a hydrogen storage medium. There are as many as six crystalline phases of alane, of which α-alane is themost stable and is also the...a pure nanoaluminum-corresponding metal oxide thermite. As Fig. 2 shows, the addition ofmicron-scale aluminum hydride to a nanoaluminum–copper-oxide... hydrogen does not participate in the thermite reaction. It is quite possible that the hydrogen may react with oxygen and or the metal oxide as an

  5. Gas chromatographic separation of hydrogen isotopes using metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, F.T.

    1984-05-09

    A study was made of the properties of metal hydrides which may be suitable for use in chromatographic separation of hydrogen isotopes. Sixty-five alloys were measured, with the best having a hydrogen-deuterium separation factor of 1.35 at 60/sup 0/C. Chromatographic columns using these alloys produced deuterium enrichments of up to 3.6 in a single pass, using natural abundance hydrogen as starting material. 25 references, 16 figures, 4 tables.

  6. Synthesis of Renewable Energy Materials, Sodium Aluminum Hydride by Grignard Reagent of Al

    Directory of Open Access Journals (Sweden)

    Jun-qin Wang

    2015-01-01

    Full Text Available The research on hydrogen generation and application has attracted widespread attention around the world. This paper is to demonstrate that sodium aluminum hydride can be synthesized under simple and mild reaction condition. Being activated through organics, aluminum powder reacts with hydrogen and sodium hydride to produce sodium aluminum hydride under atmospheric pressure. The properties and composition of the sample were characterized by FTIR, XRD, SEM, and so forth. The results showed that the product through this synthesis method is sodium aluminum hydride, and it has higher purity, perfect crystal character, better stability, and good hydrogen storage property. The reaction mechanism is also discussed in detail.

  7. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of antimony by automated-hydride atomic absorption spectrophotometry

    Science.gov (United States)

    Brown, G.E.; McLain, B.J.

    1994-01-01

    The analysis of natural-water samples for antimony by automated-hydride atomic absorption spectrophotometry is described. Samples are prepared for analysis by addition of potassium and hydrochloric acid followed by an autoclave digestion. After the digestion, potassium iodide and sodium borohydride are added automatically. Antimony hydride (stibine) gas is generated, then swept into a heated quartz cell for determination of antimony by atomic absorption spectrophotometry. Precision and accuracy data are presented. Results obtained on standard reference water samples agree with means established by interlaboratory studies. Spike recoveries for actual samples range from 90 to 114 percent. Replicate analyses of water samples of varying matrices give relative standard deviations from 3 to 10 percent.

  8. Pressure-driven formation and stabilization of superconductive chromium hydrides

    Science.gov (United States)

    Yu, Shuyin; Jia, Xiaojing; Frapper, Gilles; Li, Duan; Oganov, Artem R.; Zeng, Qingfeng; Zhang, Litong

    2015-01-01

    Chromium hydride is a prototype stoichiometric transition metal hydride. The phase diagram of Cr-H system at high pressures remains largely unexplored due to the challenges in dealing with the high activation barriers and complications in handing hydrogen under pressure. We have performed an extensive structural study on Cr-H system at pressure range 0 ∼ 300 GPa using an unbiased structure prediction method based on evolutionary algorithm. Upon compression, a number of hydrides are predicted to become stable in the excess hydrogen environment and these have compositions of Cr2Hn (n = 2–4, 6, 8, 16). Cr2H3, CrH2 and Cr2H5 structures are versions of the perfect anti-NiAs-type CrH with ordered tetrahedral interstitial sites filled by H atoms. CrH3 and CrH4 exhibit host-guest structural characteristics. In CrH8, H2 units are also identified. Our study unravels that CrH is a superconductor at atmospheric pressure with an estimated transition temperature (T c) of 10.6 K, and superconductivity in CrH3 is enhanced by the metallic hydrogen sublattice with T c of 37.1 K at 81 GPa, very similar to the extensively studied MgB2. PMID:26626579

  9. Metal hydride-based thermal energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Vajo, John J.; Fang, Zhigang

    2017-10-03

    The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

  10. Air passivation of metal hydride beds for waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J. E.; Hsu, R. H. [Savannah River National Laboratory, Aiken, SC 29808 (United States)

    2008-07-15

    One waste acceptance criteria for hydride bed waste disposal is that the bed be non-pyrophoric. Batch-wise air ingress tests were performed which determined the amount of air consumed by a metal hydride bed. A desorbed, 4.4 kg titanium prototype hydride storage vessel (HSV) produced a 4.4 deg.C internal temperature rise upon the first air exposure cycle and a 0.1 deg.C temperature rise upon a second air exposure. A total of 346 sec air was consumed by the bed (0.08 sec per gram Ti). A desorbed, 9.66 kg LaNi{sub 4.25}Al{sub 0.75} prototype storage bed experienced larger temperature rises over successive cycles of air ingress and evacuation. The cycles were performed over a period of days with the bed effectively passivated after the 12. cycle. Nine to ten STP-L of air reacted with the bed producing both oxidized metal and water. (authors)

  11. Modellization of Metal Hydride Canister for Hydrogen Storage

    Directory of Open Access Journals (Sweden)

    Rocio Maceiras

    2015-06-01

    Full Text Available Hydrogen shows very interesting features for its use on-board applications as fuel cell vehicles. This paper presents the modelling of a tank with a metal hydride alloy for on-board applications, which provides good performance under ambient conditions. The metal hydride contained in the tank is Ti0.98Zr0.02V0.43Fe0.09Cr0.05Mn1.5. A two-dimensional model has been performed for the refuelling process (absorption and the discharge process (desorption. For that, individual models of mass balance, energy balance, reaction kinetics and behaviour of hydrogen gas has been modelled. The model has been developed under Matlab / Simulink© environment. Finally, individual models have been integrated into a global model, and simulated under ambient conditions. With the aim to analyse the temperature influence on the state of charge and filling and emptying time, other simulations were performed at different temperatures. The obtained results allow to conclude that this alloy offers a good behaviour with the discharge process under normal ambient conditions. Keywords: Hydrogen storage; metal hydrides; fuel cell; simulation; board applications

  12. Performance study of a hydrogen powered metal hydride actuator

    Science.gov (United States)

    Mainul Hossain Bhuiya, Md; Kim, Kwang J.

    2016-04-01

    A thermally driven hydrogen powered actuator integrating metal hydride hydrogen storage reactor, which is compact, noiseless, and able to generate smooth actuation, is presented in this article. To test the plausibility of a thermally driven actuator, a conventional piston type actuator was integrated with LaNi5 based hydrogen storage system. Copper encapsulation followed by compaction of particles into pellets, were adopted to improve overall thermal conductivity of the reactor. The operation of the actuator was thoroughly investigated for an array of operating temperature ranges. Temperature swing of the hydride reactor triggering smooth and noiseless actuation over several operating temperature ranges were monitored for quantification of actuator efficiency. Overall, the actuator generated smooth and consistent strokes during repeated cycles of operation. The efficiency of the actuator was found to be as high as 13.36% for operating a temperature range of 20 °C-50 °C. Stress-strain characteristics, actuation hysteresis etc were studied experimentally. Comparison of stress-strain characteristics of the proposed actuator with traditional actuators, artificial muscles and so on was made. The study suggests that design modification and use of high pressure hydride may enhance the performance and broaden the application horizon of the proposed actuator in future.

  13. Dual-mode chemical vapor generation for simultaneous determination of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry.

    Science.gov (United States)

    Wang, Yu; Xu, Kailai; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-05-21

    A dual-mode chemical vapor generation integrating hydride generation and photochemical vapor generation was developed for simultaneous multi-element analysis of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry. Four elements were selected as model elements of hydride-forming (As, Cd) and non-hydride-forming (Ni, Fe) elements to validate this proposed method. Standard or sample solutions were separately pumped to mix with tetrahydroborate, and concentrated formic acid and ammonia, and then directed to a hydride generator and a photochemical reactor to realize simultaneous hydride generation and photochemical vapor generation, respectively. Optimum conditions for dual-mode chemical vapor generation were carefully investigated. Under the optimized conditions, limits of detection of 0.05, 0.008, 0.8 and 0.1 μg L(-1) were obtained for As, Cd, Fe and Ni, respectively. The precisions were 5.0, 5.5, 4.3 and 4.5% (n = 6, RSDs) for 2 μg L(-1) of As, 1 μg L(-1) of Cd, 50 μg L(-1) of Fe and 10 μg L(-1) of Ni, respectively. This method was validated for accuracy with three certified reference water samples and applied to the simultaneous determination of these elements in a tap water sample with spike recoveries in the range of 95-99%.

  14. Hydrogen storage and evolution catalysed by metal hydride complexes.

    Science.gov (United States)

    Fukuzumi, Shunichi; Suenobu, Tomoyoshi

    2013-01-07

    The storage and evolution of hydrogen are catalysed by appropriate metal hydride complexes. Hydrogenation of carbon dioxide by hydrogen is catalysed by a [C,N] cyclometalated organoiridium complex, [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoic acid-κC(3))(OH(2))](2)SO(4) [Ir-OH(2)](2)SO(4), under atmospheric pressure of H(2) and CO(2) in weakly basic water (pH 7.5) at room temperature. The reverse reaction, i.e., hydrogen evolution from formate, is also catalysed by [Ir-OH(2)](+) in acidic water (pH 2.8) at room temperature. Thus, interconversion between hydrogen and formic acid in water at ambient temperature and pressure has been achieved by using [Ir-OH(2)](+) as an efficient catalyst in both directions depending on pH. The Ir complex [Ir-OH(2)](+) also catalyses regioselective hydrogenation of the oxidised form of β-nicotinamide adenine dinucleotide (NAD(+)) to produce the 1,4-reduced form (NADH) under atmospheric pressure of H(2) at room temperature in weakly basic water. In weakly acidic water, the complex [Ir-OH(2)](+) also catalyses the reverse reaction, i.e., hydrogen evolution from NADH to produce NAD(+) at room temperature. Thus, interconversion between NADH (and H(+)) and NAD(+) (and H(2)) has also been achieved by using [Ir-OH(2)](+) as an efficient catalyst and by changing pH. The iridium hydride complex formed by the reduction of [Ir-OH(2)](+) by H(2) and NADH is responsible for the hydrogen evolution. Photoirradiation (λ > 330 nm) of an aqueous solution of the Ir-hydride complex produced by the reduction of [Ir-OH(2)](+) with alcohols resulted in the quantitative conversion to a unique [C,C] cyclometalated Ir-hydride complex, which can catalyse hydrogen evolution from alcohols in a basic aqueous solution (pH 11.9). The catalytic mechanisms of the hydrogen storage and evolution are discussed by focusing on the reactivity of Ir-hydride complexes.

  15. Reactivity patterns of transition metal hydrides and alkyls

    Energy Technology Data Exchange (ETDEWEB)

    Jones, W.D. II

    1979-05-01

    The complex PPN/sup +/ CpV(CO)/sub 3/H/sup -/ (Cp=eta/sup 5/-C/sub 5/H/sub 5/ and PPN = (Ph/sub 3/P)/sub 2/) was prepared in 70% yield and its physical properties and chemical reactions investigated. PPN/sup +/ CpV(CO)/sub 3/H/sup -/ reacts with a wide range of organic halides. The organometallic products of these reactions are the vanadium halides PPN/sup +/(CpV(C)/sub 3/X)/sup -/ and in some cases the binuclear bridging hydride PPN/sup +/ (CpV(CO)/sub 3/)/sub 2/H/sup -/. The borohydride salt PPN/sup +/(CpV(CO)/sub 3/BH/sub 4/)/sup -/ has also been prepared. The reaction between CpV(CO)/sub 3/H/sup -/ and organic halides was investigated and compared with halide reductions carried out using tri-n-butyltin hydride. Results demonstrate that in almost all cases, the reduction reaction proceeds via free radical intermediates which are generated in a chain process, and are trapped by hydrogen transfer from CpV(CO)/sub 3/H/sup -/. Sodium amalgam reduction of CpRh(CO)/sub 2/ or a mixture of CpRh(CO)/sub 2/ and CpCo(CO)/sub 2/ affords two new anions, PPN/sup +/ (Cp/sub 2/Rh/sub 3/(CO)/sub 4/)/sup -/ and PPN/sup +/(Cp/sub 2/RhCo(CO)/sub 2/)/sup -/. CpMo(CO)/sub 3/H reacts with CpMo(CO)/sub 3/R (R=CH/sub 3/,C/sub 2/H/sub 5/, CH/sub 2/C/sub 6/H/sub 5/) at 25 to 50/sup 0/C to produce aldehyde RCHO and the dimers (CpMo(CO)/sub 3/)/sub 2/ and (CpMo(CO)/sub 2/)/sub 2/. In general, CpV(CO)/sub 3/H/sup -/ appears to transfer a hydrogen atom to the metal radical anion formed in an electron transfer process, whereas CpMo(CO)/sub 3/H transfers hydride in a 2-electron process to a vacant coordination site. The chemical consequences are that CpV(CO)/sub 3/H/sup -/ generally reacts with metal alkyls to give alkanes via intermediate alkyl hydride species whereas CpMo(CO)/sub 3/H reacts with metal alkyls to produce aldehyde, via an intermediate acyl hydride species.

  16. Reactivity patterns of transition metal hydrides and alkyls

    Energy Technology Data Exchange (ETDEWEB)

    Jones, W.D. II

    1979-05-01

    The complex PPN/sup +/ CpV(CO)/sub 3/H/sup -/ (Cp=eta/sup 5/-C/sub 5/H/sub 5/ and PPN = (Ph/sub 3/P)/sub 2/) was prepared in 70% yield and its physical properties and chemical reactions investigated. PPN/sup +/ CpV(CO)/sub 3/H/sup -/ reacts with a wide range of organic halides. The organometallic products of these reactions are the vanadium halides PPN/sup +/(CpV(C)/sub 3/X)/sup -/ and in some cases the binuclear bridging hydride PPN/sup +/ (CpV(CO)/sub 3/)/sub 2/H/sup -/. The borohydride salt PPN/sup +/(CpV(CO)/sub 3/BH/sub 4/)/sup -/ has also been prepared. The reaction between CpV(CO)/sub 3/H/sup -/ and organic halides was investigated and compared with halide reductions carried out using tri-n-butyltin hydride. Results demonstrate that in almost all cases, the reduction reaction proceeds via free radical intermediates which are generated in a chain process, and are trapped by hydrogen transfer from CpV(CO)/sub 3/H/sup -/. Sodium amalgam reduction of CpRh(CO)/sub 2/ or a mixture of CpRh(CO)/sub 2/ and CpCo(CO)/sub 2/ affords two new anions, PPN/sup +/ (Cp/sub 2/Rh/sub 3/(CO)/sub 4/)/sup -/ and PPN/sup +/(Cp/sub 2/RhCo(CO)/sub 2/)/sup -/. CpMo(CO)/sub 3/H reacts with CpMo(CO)/sub 3/R (R=CH/sub 3/,C/sub 2/H/sub 5/, CH/sub 2/C/sub 6/H/sub 5/) at 25 to 50/sup 0/C to produce aldehyde RCHO and the dimers (CpMo(CO)/sub 3/)/sub 2/ and (CpMo(CO)/sub 2/)/sub 2/. In general, CpV(CO)/sub 3/H/sup -/ appears to transfer a hydrogen atom to the metal radical anion formed in an electron transfer process, whereas CpMo(CO)/sub 3/H transfers hydride in a 2-electron process to a vacant coordination site. The chemical consequences are that CpV(CO)/sub 3/H/sup -/ generally reacts with metal alkyls to give alkanes via intermediate alkyl hydride species whereas CpMo(CO)/sub 3/H reacts with metal alkyls to produce aldehyde, via an intermediate acyl hydride species.

  17. Carbene-metal hydrides can be much less acidic than phosphine-metal hydrides: significance in hydrogenations.

    Science.gov (United States)

    Zhu, Ye; Fan, Yubo; Burgess, Kevin

    2010-05-05

    Acidities of iridium hydride intermediates were shown to be critical in some transformations mediated by the chiral analogues of Crabtree's catalyst, 1-3. To do this, several experiments were undertaken to investigate the acidities of hydrogenation mixtures formed using these iridium-oxazoline complexes. DFT calculations indicated that the acidity difference for Ir-H intermediates in these hydrogenations were astounding; iridium hydride from the N-heterocyclic carbene catalyst 1 was calculated to be around seven pK(a) units less acidic than those from the P-based complexes 2 and 3. Consistent with this, the carbene complex 1 was shown to be more effective for hydrogenations of acid-sensitive substrates. In deuteration experiments, less "abnormal" deuteration was observed, corresponding to fewer complications from acid-mediated alkene isomerization preceding the D(2)-addition step. Finally, simple tests with pH indicators provided visual evidence that phosphine-based catalyst precursors give significantly more acidic reaction mixtures than the corresponding N-heterocyclic carbene ones. These observations indicate carbene-for-phosphine (and similar) ligand substitutions may impact the outcome of catalytic reactions by modifying the acidities of the metal hydrides formed.

  18. Fluorosis varied treatment options

    OpenAIRE

    Sherwood I

    2010-01-01

    Fluorosis has been reported way back in 1901. The treatment options for fluorosis are varied depending upon individual cases. This article comes from Madurai in India where its surrounding towns are fluorosis-prone zones. The purpose of this article is to report various treatment options available for dental fluorosis; this is the first time that complete full mouth rehabilitation for dental fluorosis is being reported. This article also dwells on the need for the dentists to be aware of thei...

  19. Low-Cost Metal Hydride Thermal Energy Storage System for Concentrating Solar Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Zidan, Ragaiy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hardy, B. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Corgnale, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Teprovich, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ward, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Motyka, Ted [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-01-31

    The objective of this research was to evaluate and demonstrate a metal hydride-based TES system for use with a CSP system. A unique approach has been applied to this project that combines our modeling experience with the extensive material knowledge and expertise at both SRNL and Curtin University (CU). Because of their high energy capacity and reasonable kinetics many metal hydride systems can be charged rapidly. Metal hydrides for vehicle applications have demonstrated charging rates in minutes and tens of minutes as opposed to hours. This coupled with high heat of reaction allows metal hydride TES systems to produce very high thermal power rates (approx. 1kW per 6-8 kg of material). A major objective of this work is to evaluate some of the new metal hydride materials that have recently become available. A problem with metal hydride TES systems in the past has been selecting a suitable high capacity low temperature metal hydride material to pair with the high temperature material. A unique aspect of metal hydride TES systems is that many of these systems can be located on or near dish/engine collectors due to their high thermal capacity and small size. The primary objective of this work is to develop a high enthalpy metal hydride that is capable of reversibly storing hydrogen at high temperatures (> 650 °C) and that can be paired with a suitable low enthalpy metal hydride with low cost materials. Furthermore, a demonstration of hydrogen cycling between the two hydride beds is desired.

  20. Tracing Outflows and Accretion: A Bimodal Azimuthal Dependence of MgII Absorption

    CERN Document Server

    Kacprzak, G G; Nielsen, N M

    2012-01-01

    We report a bimodality in the azimuthal angle distribution of gas around galaxies as traced by MgII absorption: Halo gas prefers to exist near the projected galaxy major and minor axes. The bimodality is demonstrated by computing the mean azimuthal angle probability distribution function using 88 spectroscopically confirmed MgII absorption-selected galaxies [W_r(2796)> 0.1A] and 35 spectroscopically confirmed non-absorbing galaxies [W_r(2796)<0.1A] imaged with HST and SDSS. The azimuthal angle distribution for non-absorbers is flat, indicating no azimuthal preference for gas characterized by W_r(2796)<0.1A. We find that blue star-forming galaxies clearly drive the bimodality. We compute an azimuthal angle dependent MgII absorption covering fraction and find that it is enhanced by as much as 20-30% along the major and minor axes. The equivalent width distribution for gas along the major axis is likely skewed toward weaker MgII absorption than for gas along the projected minor axis. These combined results...

  1. Forecasting Fractures in Coal Seams by Using Azimuthal Anisotropy from P-Wave Seismic Data

    Institute of Scientific and Technical Information of China (English)

    DONG Shou-hua; YUE Jian-hua; ZHANG Fen-xuan

    2007-01-01

    If the thickness of coal seams and the lithology of both roofs and floors of coal seams have not changed at all or only a little, then it is thought that the elastic anisotropy of coal seams depends mainly on fractures and obeys the horizontally symmetric model of an azimuth anisotropy. For a fixed offset, the amplitude A of the reflection P-wave and the cosine of 2 (ψ) has an approximately linear relation, ( (ψ) is the source-detector azimuth with respect to the fracture strike. Based on this relationship, many things can be done, such as the extraction of macro bins, the correction of residual normal moveout, the formation of azimuth gather, the transformation and normalization of azimuth gathers and the extraction of reflection wave amplitudes of coal seams. The least squares method was used to inverse theoretically the direction and density of fractures of coal seams. The result is in good agreement with the regional geological structure, indicating that the azimuth anisotropic analysis of the P-wave is feasible in evaluating the density and direction of fractures in coal seams.

  2. Formation of palladium hydrides in low temperature Ar/H{sub 2}-plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, H., E-mail: wulff@uni-greifswald.de [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Quaas, M. [LITEC-LP, Brandteichstraße 20, 17489 Greifswald (Germany); Deutsch, H.; Ahrens, H. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Fröhlich, M. [Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2 (Germany); Helm, C.A. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany)

    2015-12-01

    20 nm thick Pd coatings deposited on Si substrates with 800 nm SiO{sub 2} and 1 nm Cr buffer layers were treated in a 2.45 GHz microwave plasma source at 700 W plasma power and 40 Pa working pressure without substrate heating. For obtaining information on the effect of energy influx due to ion energy on the palladium films the substrate potential was varied from U{sub sub} = 0 V to − 150 V at constant gas flow corresponding to mean ion energies E{sub i} from 0.22 eV ∙ cm{sup −2} ∙ s{sup −1} to 1.28 eV ∙ cm{sup −2} ∙ s{sup −1}. In contrast to high pressure reactions with metallic Pd, under plasma exposure we do not observe solid solutions over a wide range of hydrogen concentration. The hydrogen incorporation in Pd films takes place discontinuously. At 0 V substrate voltage palladium hydride is formed in two steps to PdH{sub 0.14} and PdH{sub 0.57}. At − 50 V substrate voltage PdH{sub 0.57} is formed directly. However, substrate voltages of − 100 V and − 150 V cause shrinking of the unit cell. We postulate the formation of two fcc vacancy palladium hydride clusters PdH{sub Vac}(I) and PdH{sub Vac}(II). Under longtime plasma exposure the fcc PdH{sub Vac}(II) phase forms cubic PdH{sub 1.33}. The fcc PdH{sub 0.57} phase decomposes at temperatures > 300 °C to form metallic fcc Pd. The hydrogen removal causes a decrease of lattice defects. In situ high temperature diffractometry measurements also confirm the existence of PdH{sub Vac}(II) as a palladium hydride phase. Stoichiometric relationship between cubic PdH{sub 1.33} and fcc PdH{sub Vac}(II) becomes evident from XR measurements and structure considerations. We assume both phases have the chemical composition Pd{sub 3}H{sub 4}. Up to 700 °C we observe phase transformation between both the fcc PdH{sub Vac}(II) and cubic PdH{sub 1.33} phases. These phase transformations could be explained analog to a Bain distortion by displacive solid state structural changes. - Highlights: • Thin Pd films

  3. Fluorosis varied treatment options

    Directory of Open Access Journals (Sweden)

    Sherwood I

    2010-01-01

    Full Text Available Fluorosis has been reported way back in 1901. The treatment options for fluorosis are varied depending upon individual cases. This article comes from Madurai in India where its surrounding towns are fluorosis-prone zones. The purpose of this article is to report various treatment options available for dental fluorosis; this is the first time that complete full mouth rehabilitation for dental fluorosis is being reported. This article also dwells on the need for the dentists to be aware of their local indigenous pathologies to treat it in a better manner.

  4. Crack initiation at long radial hydrides in Zr-2. 5Nb pressure tube material at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, R.; Puls, M.P. (AECL Research, Pinawa, Manitoba (Canada). Whiteshell Labs.)

    1994-05-01

    Crack initiation at hydrides in smooth tensile specimens of Zr-2.5Nb pressure tube material was investigated at elevated temperatures up to 300 C using an acoustic emission (AE) technique. The test specimens contained long, radial hydride platelets. These hydrides have their plate normals oriented in the applied stress direction. Below [approximately]100 C, widespread hydride cracking was initiated at stresses close to the yield stress. An estimate of the hydride's fracture strength from this data yielded a value of [approximately]520 MPa at 100 C. Metallography showed that up to this temperature, cracking occurred along the length of the hydrides. However, at higher temperatures, there was no clear evidence of lengthwise cracking of hydrides, and fewer of the total hydride population fractured during deformation, as indicated by the AE record and the metallography. Moreover, the hydrides showed significant plasticity by-being able to flow along with the matrix material and align themselves parallel to the applied stress direction without fracturing. Near the fracture surface of the specimen, transverse cracking of the flow-reoriented hydrides had occurred at various points along the lengths of the hydrides. These fractures appear to be the result of stresses produced by large plastic strains imposed by the surrounding matrix on the less ductile hydrides.

  5. Well-Defined Molecular Magnesium Hydride Clusters : Relationship between Size and Hydrogen-Elimination Temperature

    NARCIS (Netherlands)

    Intemann, Julia; Spielmann, Jan; Sirsch, Peter; Harder, Sjoerd

    A new tetranuclear magnesium hydride cluster, [{NN-(MgH)2}2], which was based on a NN-coupled bis--diketiminate ligand (NN2-), was obtained from the reaction of [{NN-(MgnBu)2}2] with PhSiH3. Its crystal structure reveals an almost-tetrahedral arrangement of Mg atoms and two different sets of hydride

  6. Zirconium hydrides and Fe redistribution in Zr-2.5%Nb alloy under ion irradiation

    Science.gov (United States)

    Idrees, Y.; Yao, Z.; Cui, J.; Shek, G. K.; Daymond, M. R.

    2016-11-01

    Zr-2.5%Nb alloy is used to fabricate the pressure tubes of the CANDU reactor. The pressure tube is the primary pressure boundary for coolant in the CANDU design and is susceptible to delayed hydride cracking, reduction in fracture toughness upon hydride precipitation and potentially hydride blister formation. The morphology and nature of hydrides in Zr-2.5%Nb with 100 wppm hydrogen has been investigated using transmission electron microscopy. The effect of hydrides on heavy ion irradiation induced decomposition of the β phase has been reported. STEM-EDX mapping was employed to investigate the distribution of alloying elements. The results show that hydrides are present in the form of stacks of different sizes, with length scales from nano- to micro-meters. Heavy ion irradiation experiments at 250 °C on as-received and hydrided Zr-2.5%Nb alloy, show interesting effects of hydrogen on the irradiation induced redistribution of Fe. It was found that Fe is widely redistributed from the β phase into the α phase in the as-received material, however, the loss of Fe from the β phase and subsequent precipitation is retarded in the hydrided material. This preliminary work will further the current understanding of microstructural evolution of Zr based alloys in the presence of hydrogen.

  7. Arsenic speciation analysis by HPLC postcolumn hydride generation and detection by atomic fluorescence spectrometry

    OpenAIRE

    Marschner, K; Musil, S. (Stanislav); Rychlovský, P.; Dědina, J. (Jiří)

    2014-01-01

    The aim of this contribution is to present a new method of hydride generation that enables to generate arsines from iAs , iAs , MMA and DMA in a flow injection mode with the same efficiency and in the next step connection of this hydride generator with HPLC column.

  8. Pore-Confined Light Metal Hydrides for Energy Storage and Catalysis

    NARCIS (Netherlands)

    Bramwell, P.L.

    2017-01-01

    Light metal hydrides have enjoyed several decades of attention in the field of hydrogen storage, but their applications have recently begun to diversify more and more into the broader field of energy storage. For example, light metal hydrides have shown great promise as battery materials, in sensors

  9. Experimental comparison on heat transfer-enhancing component of metal hydride bed

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun-goo, E-mail: hgkang@nfri.re.kr; Chung, Dong-you; Oh, Yun Hee; Chang, Min Ho; Yun, Sei-Hun

    2016-11-01

    Highlights: • Two small ZrCo metal hydride beds were developed. • Copper foam or fin as heat transfer-enhancing component are experimentally compared. • Copper foam bed is more efficient for uniform and rapid heating of metal hydride. • Copper foam bed is more efficient in removal of reaction heat during absorption. - Abstract: Metal hydride bed will be one of the key components for safe handling of tritium in fusion fuel cycle. In case of normal or emergency shutdown of fuel cycle, metal hydride bed installed in storage and delivery system (SDS) of tritium plant will absorb tritium gas in the system as soon as possible. Supply of hydrogen isotope gas to fueling system of fusion reactor will start from the metal hydride beds. Rapid delivery, rapid recovery including rapid heating and cooling are key issues. For better performance of metal hydride bed, various forms of heat transfer enhancing component or design can be applied. This study aims to help the selection of heat transfer enhancing component. Two small ZrCo beds with copper foam and copper fin were developed and experimented with hydrogen gas. Recovery and delivery performance, heating and cooling performance are compared. Experimental results show metal hydride bed with copper foam has improved performance. Uniform heating of metal hydride during desorption and removal of reaction heat during absorption are more efficient with copper foam bed than copper fin bed.

  10. Study on the Use of Hydride Fuel in High-Performance Light Water Reactor Concept

    Directory of Open Access Journals (Sweden)

    Haileyesus Tsige-Tamirat

    2015-01-01

    Full Text Available Hydride fuels have features which could make their use attractive in future advanced power reactors. The potential benefit of use of hydride fuel in HPLWR without introducing significant modification in the current core design concept of the high-performance light water reactor (HPLWR has been evaluated. Neutronics and thermal hydraulic analyses were performed for a single assembly model of HPLWR with oxide and hydride fuels. The hydride assembly shows higher moderation with softer neutron spectrum and slightly more uniform axial power distribution. It achieves a cycle length of 18 months with sufficient excess reactivity. At Beginning of Cycle the fuel temperature coefficient of the hydride assembly is higher whereas the moderator and void coefficients are lower. The thermal hydraulic results show that the achievable fuel temperature in the hydride assembly is well below the design limits. The potential benefits of the use of hydride fuel in the current design of the HPLWR with the achieved improvements in the core neutronics characteristics are not sufficient to justify the replacement of the oxide fuel. Therefore for a final evaluation of the use of hydride fuels in HPLWR concepts additional studies which include modification of subassembly and core layout designs are required.

  11. Theoretical study on hydrogenation catalysts containing a metal hydride as additional hydrogen supply

    NARCIS (Netherlands)

    Snijder, E.D.; Versteeg, G.F.; Swaaij, W.P.M. van

    1992-01-01

    A hypothetical hydrogenation catalyst consisting of porous, catalytically active particles embedded with metal hydride powder was evaluated. The metal hydride provides temporarily additional hydrogen if the mass transfer rate of the hydrogen to the internal of the particle is not sufficient. A numer

  12. First-principles study of superabundant vacancy formation in metal hydrides.

    Science.gov (United States)

    Zhang, Changjun; Alavi, Ali

    2005-07-13

    Recent experiments have established the generality of superabundant vacancies (SAV) formation in metal hydrides. Aiming to elucidate this intriguing phenomenon and to clarify previous interpretations, we employ density-functional theory to investigate atomic mechanisms of SAV formation in fcc hydrides of Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au. We have found that upon H insertion, vacancy formation energies reduce substantially. This is consistent with experimental suggestions. We demonstrate that the entropy effect, which has been proposed to explain SAV formation, is not the main cause. Instead, it is the drastic change of electronic structure induced by the H in the SAV hydrides, which is to a large extent responsible. Interesting trends in systems investigated are also found: ideal hydrides of 5d metals and noble metals are unstable compared to the corresponding pure metals, but the SAV hydrides are more stable than the corresponding ideal hydrides, whereas opposite results exist in the cases of Ni, Rh, and Pd. These trends of stabilities of the SAV hydrides are discussed in detail and a general understanding for SAV formation is provided. Finally, we propose an alternative reaction pathway to generate a SAV hydride from a metal alloy.

  13. Complex transition metal hydrides: linear correlation of countercation electronegativity versus T-D bond lengths.

    Science.gov (United States)

    Humphries, T D; Sheppard, D A; Buckley, C E

    2015-06-30

    For homoleptic 18-electron complex hydrides, an inverse linear correlation has been established between the T-deuterium bond length (T = Fe, Co, Ni) and the average electronegativity of the metal countercations. This relationship can be further employed towards aiding structural solutions and predicting physical properties of novel complex transition metal hydrides.

  14. Active correction of the tilt angle of the surface plane with respect to the rotation axis during azimuthal scan

    CERN Document Server

    Sereno, M; Debiossac, M; Kalashnyk, N; Roncin, P

    2016-01-01

    A procedure to measure the residual tilt angle $\\tau$ between a flat surface and the azimuthal rotation axis of the sample holder is described. When the incidence angle $\\theta$ and readout of the azimuthal angle $\\phi$ are controlled by motors, an active compensation mechanism can be implemented to reduce the effect of the tilt angle during azimuthal motion. After this correction, the effective angle of incidence is kept fixed, and only the small residual oscillation of the scattering plane remains.

  15. Charge-dependent azimuthal correlations from AuAu to UU collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bloczynski, John [Physics Department and Center for Exploration of Energy and Matter, Indiana University, 2401 N Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Huang, Xu-Guang, E-mail: huangxuguang@fudan.edu.cn [Physics Department and Center for Exploration of Energy and Matter, Indiana University, 2401 N Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Physics Department and Center for Field Theory and Particle Physics, Fudan University, Shanghai 200433 (China); Zhang, Xilin [Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Liao, Jinfeng [Physics Department and Center for Exploration of Energy and Matter, Indiana University, 2401 N Milo B. Sampson Lane, Bloomington, IN 47408 (United States); RIKEN BNL Research Center, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-07-15

    We study the charge-dependent azimuthal correlations in relativistic heavy ion collisions, as motivated by the search for the Chiral Magnetic Effect (CME) and the investigation of related background contributions. In particular we aim to understand how these correlations induced by various proposed effects evolve from collisions with AuAu system to that with UU system. To do that, we quantify the generation of magnetic field in UU collisions at RHIC energy and its azimuthal correlation with the matter geometry using event-by-event simulations. Taking the experimental data for charge-dependent azimuthal correlations from AuAu collisions and extrapolating to UU with reasonable assumptions, we examine the resulting correlations to be expected in UU collisions and compare them with recent STAR measurements. Based on such analysis we discuss the viability for explaining the data with a combination of the CME-like and flow-induced contributions.

  16. Cassini UVIS Observations of the Io Plasma Torus. IV. Modeling Temporal and Azimuthal Variability

    CERN Document Server

    Steffl, A J; Bagenal, F

    2007-01-01

    In this fourth paper in a series, we present the results of our efforts to model the remarkable temporal and azimuthal variability of the Io plasma torus during the Cassini encounter with Jupiter. The long-term (months) temporal variation in the average torus composition observed by the Cassini Ultraviolet Imaging Spectrograph (UVIS) can be modeled by supposing a factor of ~4 increase in the amount of material supplied to the extended neutral clouds that are the source of torus plasma, followed by a gradual decay to more "typical" values. On shorter timescales, the observed 10.07-hour torus periodicity and azimuthal variation in plasma composition, including its surprising modulation with System III longitude, is reproduced by our model using the superposition of two azimuthal variations of suprathermal electrons: a primary hot electron variation that slips 12.5 degrees/day relative to the Jovian magnetic field and a secondary variation that remains fixed in System III longitude.

  17. ANALYSIS OF METHOD FOR DETERMINING AZIMUTH OF PRINCIPAL AXIS OF INERTIA BASED ON DYNAMIC BALANCE MEASUREMENT

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; GUAN Yingzi; QI Naiming

    2006-01-01

    The dynamic balance quality of a rotating object is an important factor to maintain the stability and accuracy for motion. The azimuth of the principal axis of inertia is a major sign of dynamic balance. A usual method is measuring moment of inertia matrix relative to some base coordinates on a rotary inertia machine so as to calculate the azimuth of principal axis of inertia. By using the measured unbalance results on the two trimmed planes on a vertical hard bearing double-plane dynamic balancing machine, the dimension and direction of couple unbalance can be found. An azimuth angle formula for the principal axis of inertia is derived and is solved by using unbalance quantities. The experiments indicate that method based on dynamic balancing measurement is proved rational and effective and has a fine precision.

  18. Near- and far-field properties of plasmonic oligomers under radially and azimuthally polarized light excitation.

    Science.gov (United States)

    Yanai, Avner; Grajower, Meir; Lerman, Gilad M; Hentschel, Mario; Giessen, Harald; Levy, Uriel

    2014-05-27

    We present a comprehensive experimental and theoretical study on the near- and far-field properties of plasmonic oligomers using radially and azimuthally polarized excitation. These unconventional polarization states are perfectly matched to the high spatial symmetry of the oligomers and thus allow for the excitation of some of the highly symmetric eigenmodes of the structures, which cannot be excited by linearly polarized light. In particular, we study hexamer and heptamer structures and strikingly find very similar optical responses, as well as the absence of a Fano resonance. Furthermore, we investigate the near-field distributions of the oligomers using near-field scanning optical microscopy (NSOM). We observe significantly enhanced near-fields, which arise from efficient excitation of the highly symmetric eigenmodes by the radially and azimuthally polarized light fields. Our study opens up possibilities for tailored light-matter interaction, combining the design freedom of complex plasmonic structures with the remarkable properties of radially and azimuthally polarized light fields.

  19. Methods and applications of 3-D wave equation common-azimuth prestack migration

    Institute of Scientific and Technical Information of China (English)

    CHENG Jiubing; WANG Huazhong; GENG Jianhua; MA Zaitian

    2007-01-01

    To tackle the difficulties of a 3-D full volum eprestack migration based on the double-square-root (DSR) one-way wave equation in practical applications, the common-azimuth migration approach is first discussed using dual-domain wave propagators under the theoretical frame of crossline common-offset migration. Through coor-dinate transforming, a common-azimuth prestack tau migra-tion technology that recursively continues the source and receiver wavefields and picks up the migrated results in the two-way vertical traveltime (tau) direction is developed.The migrations of synthetic data sets of SEG/EAGE salt model prove that our common-azimuth migration approaches are effective in both depth and tau domains. Two real data examples show the advantages of wave-theory based prestack migration methods in accuracy and imaging resolution over the conventional Kirchhoff integral methods.

  20. Focusing Azimuth-Invariant Bistatic Synthetic Aperture Radar Data Based on a Polynomial Model

    Institute of Scientific and Technical Information of China (English)

    ZHONG Hua; LIU Xing-zhao; WANG Jun-feng

    2009-01-01

    In this paper, a focusing approach is presented to widen the use of efficient monostatic imaging algorithms for azimuth-invariant bistatic synthetic aperture radar (SAR) data. The bistatic range history is modeled by a polynomial of azimuth time. Using this model, an analytic form of the signal spectrum in the 2D frequency domain is derived, and a simple single-valued relation between the transmitter and receive ranges is established. In this way, a lot of monostatic image formation algorithms can be extended for the bistatic SAR data, and a bistatic chirp scaling algorithm is developed as an application of the new approach. This algorithm can be used to process the azimuth-invariant bistatic configuration where the transmitter and receiver platforms are moving on parallel tracks with the same velocity. In addition, some simulation results are given to demonstrate the validity of the proposed approach.

  1. Suppressing azimuth ambiguity in spaceborne SAR images based on compressed sensing

    Institute of Scientific and Technical Information of China (English)

    YU Ze; LIU Min

    2012-01-01

    In spaceborne synthetic aperture radar,undersampling at the rate of the pulse repetition frequency causes azimuth ambiguity,which induces ghost into the images.This paper introduces compressed sensing for azimuth ambiguity suppression and presents two novel methods from the perspectives of system design and image formation,known as azimuth random sampling and ambiguity separation,respectively.The first method makes the imaging results for the ambiguity zones as disperse as possible while ensuring that the imaging results for the main scene are affected as little as possible.The second method separates the ambiguity signals from the echoes and achieves imaging results without the ambiguity effect.Simulation results show that the two methods can reduce the ambiguity levels by about 16 dB and 99.37%,respectively.

  2. Transverse azimuthal dephasing of vortex spin wave in a hot atomic gas

    CERN Document Server

    Shi, Shuai; Zhang, Wei; Zhou, Zhi-Yuan; Dong, Ming-Xin; Liu, Shi-Long; Shi, Bao-Sen; Guo, Guang-Can

    2016-01-01

    Optical fields with orbital angular momentum (OAM) interact with medium have many remarkable properties with its unique azimuthal phase, showing many potential applications in high capacity information processing, high precision measurement etc. The dephasing mechanics of optical fields with OAM in an interface between light and matter plays a vital role in many areas of physics. In this work, we study the transverse azimuthal dephasing of OAM spin wave in a hot atomic gas via OAM storage. The transverse azimuthal phase difference between the control and probe beams is mapped onto the spin wave, which essentially results in dephasing of atomic spin wave. The dephasing of OAM spin wave can be controlled by the parameters of OAM topological charge and beam waist. Our results are helpful for studying OAM light interaction with matter, maybe hold a promise in OAM-based quantum information processing.

  3. Magnetorotational turbulence in Taylor--Couette flow with imposed azimuthal magnetic field

    CERN Document Server

    Guseva, A; Hollerbach, R; Avila, M

    2015-01-01

    The magnetorotational instability (MRI) is thought to be a powerful source of turbulence and momentum transport in astrophysical accretion discs, but obtaining observational evidence of its operation is challenging. Recently, laboratory experiments of Taylor--Couette flow with externally imposed axial and azimuthal magnetic fields have revealed the kinematic and dynamic properties of the MRI close to the instability onset. While good agreement was found with linear stability analyses, little is known about the transition to turbulence and transport properties of the MRI. We here report on a numerical investigation of the MRI with an imposed azimuthal magnetic field. We show that the laminar Couette flow becomes unstable to a wave rotating in the azimuthal direction and standing in the axial direction via a supercritical Hopf bifurcation. Subsequently, the flow features a catastrophic transition to spatio-temporal defects which is mediated by a subcritical subharmonic Hopf bifurcation. Our results are in agree...

  4. Manipulation of Magnetization States of Permalloy Nanorings by an External Azimuthal Field

    Science.gov (United States)

    Yang, Tianyu; Pradhan, Nihar; Goldman, Abby; Kemei, Moureen; Licht, Abbey; Li, Yihan; Tuominen, Mark; Aidala, Katherine

    2011-03-01

    This experimental research investigates a new method of manipulating the magnetic states of ferromagnetic nanorings using a circular magnetic field directed along the ring circumference. This type of azimuthal field can naturally select a vortex magnetization of desired chirality. The understanding of the magnetization switching behavior in an azimuthal field could lead to new designs of practical magnetic data storage devices. Symmetric and asymmetric nanorings made of permalloy are fabricated by a standard technique using electron-beam lithography and e-beam evaporation. Azimuthal fields are generated by passing current through an atomic force microscope tip, which is positioned at the center of the ring. The magnetic field direction and magnitude are controlled by the current. We demonstrate control over switching from an onion state to a vortex state, and also between two vortex states, using magnetic force microscopy to image the resulting magnetic states. This work was supported by NSF grants DMR-0907201 CMMI-0531171.

  5. Single-Site Tetracoordinated Aluminum Hydride Supported on Mesoporous Silica. From Dream to Reality!

    KAUST Repository

    Werghi, Baraa

    2016-09-26

    The reaction of mesoporous silica (SBA15) dehydroxylated at 700 °C with diisobutylaluminum hydride, i-Bu2AlH, gives after thermal treatment a single-site tetrahedral aluminum hydride with high selectivity. The starting aluminum isobutyl and the final aluminum hydride have been fully characterized by FT-IR, advanced SS NMR spectroscopy (1H, 13C, multiple quanta (MQ) 2D 1H-1H, and 27Al), and elemental analysis, while DFT calculations provide a rationalization of the occurring reactivity. Trimeric i-Bu2AlH reacts selectively with surface silanols without affecting the siloxane bridges. Its analogous hydride catalyzes ethylene polymerization. Indeed, catalytic tests show that this single aluminum hydride site is active in the production of a high-density polyethylene (HDPE). © 2016 American Chemical Society.

  6. A mechanical-force-driven physical vapour deposition approach to fabricating complex hydride nanostructures

    Science.gov (United States)

    Pang, Yuepeng; Liu, Yongfeng; Gao, Mingxia; Ouyang, Liuzhang; Liu, Jiangwen; Wang, Hui; Zhu, Min; Pan, Hongge

    2014-03-01

    Nanoscale hydrides desorb and absorb hydrogen at faster rates and lower temperatures than bulk hydrides because of their high surface areas, abundant grain boundaries and short diffusion distances. No current methods exist for the direct fabrication of nanoscale complex hydrides (for example, alanates, borohydrides) with unique morphologies because of their extremely high reducibility, relatively low thermodynamic stability and complicated elemental composition. Here, we demonstrate a mechanical-force-driven physical vapour deposition procedure for preparing nanoscale complex hydrides without scaffolds or supports. Magnesium alanate nanorods measuring 20-40 nm in diameter and lithium borohydride nanobelts measuring 10-40 nm in width are successfully synthesised on the basis of the one-dimensional structure of the corresponding organic coordination polymers. The dehydrogenation kinetics of the magnesium alanate nanorods are improved, and the nanorod morphology persists through the dehydrogenation-hydrogenation process. Our findings may facilitate the fabrication of such hydrides with improved hydrogen storage properties for practical applications.

  7. Another Look at the Mechanisms of Hydride Transfer Enzymes with Quantum and Classical Transition Path Sampling.

    Science.gov (United States)

    Dzierlenga, Michael W; Antoniou, Dimitri; Schwartz, Steven D

    2015-04-02

    The mechanisms involved in enzymatic hydride transfer have been studied for years, but questions remain due, in part, to the difficulty of probing the effects of protein motion and hydrogen tunneling. In this study, we use transition path sampling (TPS) with normal mode centroid molecular dynamics (CMD) to calculate the barrier to hydride transfer in yeast alcohol dehydrogenase (YADH) and human heart lactate dehydrogenase (LDH). Calculation of the work applied to the hydride allowed for observation of the change in barrier height upon inclusion of quantum dynamics. Similar calculations were performed using deuterium as the transferring particle in order to approximate kinetic isotope effects (KIEs). The change in barrier height in YADH is indicative of a zero-point energy (ZPE) contribution and is evidence that catalysis occurs via a protein compression that mediates a near-barrierless hydride transfer. Calculation of the KIE using the difference in barrier height between the hydride and deuteride agreed well with experimental results.

  8. Hydrogenation reaction characteristics and properties of its hydrides for magnetic regenerative material HoCu2

    Institute of Scientific and Technical Information of China (English)

    金滔; 吴梦茜; 黄迦乐; 汤珂; 陈立新

    2016-01-01

    The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu2 (CeCu2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of HoCu2 were a mixture of Cu, unknown hydride I, and unknown hydride II. Based on the PCT (pressure−concentration−temperature) curves under different reaction temperatures, the relationships among reaction temperature, equilibrium pressure, and maximum hydrogen absorption capacity were analyzed and discussed. The enthalpy changeΔH and entropy changeΔS as a result of the whole hydrogenation process were also calculated from the PCT curves. The magnetization and volumetric specific heat capacity of the hydride were also measured by SQUID magnetometer and PPMS, respectively.

  9. Complex rare-earth aluminum hydrides: mechanochemical preparation, crystal structure and potential for hydrogen storage.

    Science.gov (United States)

    Weidenthaler, Claudia; Pommerin, André; Felderhoff, Michael; Sun, Wenhao; Wolverton, Christopher; Bogdanović, Borislav; Schüth, Ferdi

    2009-11-25

    A novel type of complex rare-earth aluminum hydride was prepared by mechanochemical preparation. The crystal structure of the REAlH(6) (with RE = La, Ce, Pr, Nd) compounds was calculated by DFT methods and confirmed by preliminary structure refinements. The trigonal crystal structure consists of isolated [AlH(6)](3-) octahedra bridged via [12] coordinated RE cations. The investigation of the rare-earth aluminum hydrides during thermolysis shows a decrease of thermal stability with increasing atomic number of the RE element. Rare-earth hydrides (REH(x)) are formed as primary dehydrogenation products; the final products are RE-aluminum alloys. The calculated decomposition enthalpies of the rare-earth aluminum hydrides are at the lower end for reversible hydrogenation under moderate conditions. Even though these materials may require somewhat higher pressures and/or lower temperatures for rehydrogenation, they are interesting examples of low-temperature metal hydrides for which reversibility might be reached.

  10. Strategies for the improvement of the hydrogen storage properties of metal hydride materials.

    Science.gov (United States)

    Wu, Hui

    2008-10-24

    Metal hydrides are an important family of materials that can potentially be used for safe, efficient and reversible on-board hydrogen storage. Light-weight metal hydrides in particular have attracted intense interest due to their high hydrogen density. However, most of these hydrides have rather slow absorption kinetics, relatively high thermal stability, and/or problems with the reversibility of hydrogen absorption/desorption cycling. This paper discusses a number of different approaches for the improvement of the hydrogen storage properties of these materials, with emphasis on recent research on tuning the ionic mobility in mixed hydrides. This concept opens a promising pathway to accelerate hydrogenation kinetics, reduce the activation energy for hydrogen release, and minimize deleterious possible by-products often associated with complex hydride systems.

  11. Getting metal-hydrides to do what you want them to

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, D.M.

    1981-01-01

    With the discovery of AB/sub 5/ compounds, intermetallic hydrides with unusual properties began to be developed (H dissociation pressures of one to several atmospheres, extremely rapid and reversible adsorption/desorption very large amounts of H adsorbed). This paper reviews the factors that must be controlled in order to modify these hydrides to make them useful. The system LaNi/sub 5/ + H/sub 2/ is used as example. Use of AB/sub 5/ hydrides to construct a chemical heat pumps is discussed. Results of a systematic study substituting Al for Ni are reported; the HYCSOS pump is described briefly. Use of hydrides as hydrogen getters (substituted ZrV/sub 2/) is also discussed. Finally, possible developments in intermetallic hydride research in the 1980's and the hydrogen economy are discussed. 10 figures. (DLC)

  12. Evaluation of hydride blisters in zirconium pressure tube in CANDU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Y. M.; Kim, Y. S.; Gong, U. S.; Kwon, S. C.; Kim, S. S.; Choo, K.N

    2000-09-01

    When the garter springs for maintaining the gap between the pressure tube and the calandria tube are displaced in the CANDU reactor, the sagging of pressure tube results in a contact to the calandria tube. This causes a temperature difference between the inner and outer surface of the pressure tube. The hydride can be formed at the cold spot of outer surface and the volume expansion by hydride dormation causes the blistering in the zirconium alloys. An incident of pressure tube rupture due to the hydride blisters had happened in the Canadian CANDU reactor. This report describes the theoretical development and models on the formation and growth of hydride blister and some experimental results. The evaluation methodology and non-destructive testing for hydride blister in operating reactors are also described.

  13. Assessing nanoparticle size effects on metal hydride thermodynamics using the Wulff construction.

    Science.gov (United States)

    Kim, Ki Chul; Dai, Bing; Karl Johnson, J; Sholl, David S

    2009-05-20

    The reaction thermodynamics of metal hydrides are crucial to the use of these materials for reversible hydrogen storage. In addition to altering the kinetics of metal hydride reactions, the use of nanoparticles can also change the overall reaction thermodynamics. We use density functional theory to predict the equilibrium crystal shapes of seven metals and their hydrides via the Wulff construction. These calculations allow the impact of nanoparticle size on the thermodynamics of hydrogen release from these metal hydrides to be predicted. Specifically, we study the temperature required for the hydride to generate a H(2) pressure of 1 bar as a function of the radius of the nanoparticle. In most, but not all, cases the hydrogen release temperature increases slightly as the particle size is reduced.

  14. Hydrogenase Enzymes and Their Synthetic Models: The Role of Metal Hydrides.

    Science.gov (United States)

    Schilter, David; Camara, James M; Huynh, Mioy T; Hammes-Schiffer, Sharon; Rauchfuss, Thomas B

    2016-08-10

    Hydrogenase enzymes efficiently process H2 and protons at organometallic FeFe, NiFe, or Fe active sites. Synthetic modeling of the many H2ase states has provided insight into H2ase structure and mechanism, as well as afforded catalysts for the H2 energy vector. Particularly important are hydride-bearing states, with synthetic hydride analogues now known for each hydrogenase class. These hydrides are typically prepared by protonation of low-valent cores. Examples of FeFe and NiFe hydrides derived from H2 have also been prepared. Such chemistry is more developed than mimicry of the redox-inactive monoFe enzyme, although functional models of the latter are now emerging. Advances in physical and theoretical characterization of H2ase enzymes and synthetic models have proven key to the study of hydrides in particular, and will guide modeling efforts toward more robust and active species optimized for practical applications.

  15. A computational study on novel carbon-based lithium materials for hydrogen storage and the role of carbon in destabilizing complex metal hydrides

    Science.gov (United States)

    Ghouri, Mohammed Minhaj

    materials with varying amounts of hydrogen. A detailed analysis of the heats of reactions of these materials using different reaction schemes is performed and based on the promising thermodynamic and gravimetric storage density, LiC4Be2H5 is divulged as a promising novel carbon based lithium material. In the later part, this dissertation performs a detailed study on the effect of carbon when it is used as a dopant in four different well known complex hydrides, lithium beryllium hydride (Li2BeH4), lithium borohydride (LiBH4), lithium aluminum hydride (LiAlH 4) and sodium borohydride (NaBH4). Initially, the unit cells of the crystal structure are fully resolved using the plane-wave pseudopotential implementation of DFT. The supercells of each of these are then constructed and optimized. Varying amounts of carbon is introduced as impurity in these crystals in different sites such as the top, subsurface and the bulk of the crystal lattice. Using the electronic structure calculations, it is established that (i) C-Be-H, C-B-H or C-Al-H compounds are formed respectively in the cases of Li2BeH4, LiBH4 and LiAlH4 when carbon is doped in them; (ii) and carbon dopant causes a decrease in the bond strengths of Be-H, B-H and Al-H in respective cases. This reduction in the bond strengths combined with the fact that there is a decrease in the ionic interaction between the cation and the anionic hydride units of these complex hydrides causes a destabilization effect.

  16. Shaping the focal field of radially/azimuthally polarized phase vortex with Zernike polynomials

    CERN Document Server

    Wei, Lei

    2016-01-01

    The focal field properties of radially/azimuthally polarized Zernike polynomials are studied. A method to design the pupil field in order to shape the focal field of radially or azimuthally polarized phase vortex is introduced. With this method, we are able to obtain a pupil field to achieve a longitudinally polarized hollow spot with a depth of focus up to $12\\lambda$ and $0.14\\lambda$ lateral resolution for a optical system with numerical aperture 0.99; A pupil field to generate 8 circularly polarized focal spots along the optical axis is also obtained with this method.

  17. Azimuthal correlations of hadrons and fragments in nucleus-nucleus collisions

    Institute of Scientific and Technical Information of China (English)

    LI Hui-Ling

    2011-01-01

    Two-particle (two-fragment) azimuthal correlation functions are studied by using a simple formula which describes uniformly azimuthal distributions of final-state charged particles and nuclear fragments.This formula is obtained in the framework of a multi-source thermal model (or multi-source ideal gas model).The calculated results are compared and found to be in agreement with the experimental data of charged hadrons and nuclear fragments in nucleus-nucleus collisions at intermediate and high energies.

  18. Estudio de las maniobras de un remolcador con sistema azimuth stern drive

    OpenAIRE

    Suasi Carayol, Pedro Jose

    2015-01-01

    En el presente Trabajo de Fin de Grado, se pretende explicar los conceptos básicos del sistema Azimuth Stern Drive desde el punto de vista de maniobras. Con el fin de contextualizar al lector, se hace un breve resumen del inicio del sistema Azimuth Stern Drive y un análisis sobre los elementos técnicos que forman este sistema de propulsión tan utilizado hoy en día en Remolcadores de todo el Mundo. El cuerpo del trabajo, explica las diferentes posibilidades de movimiento que tiene un Remolcado...

  19. Dijet azimuthal decorrelations for $\\Delta \\phi_{\\rm dijet} < 2\\pi/3$ in perturbative QCD

    CERN Document Server

    Wobisch, M

    2015-01-01

    We point out an inconsistency in perturbative QCD predictions previously used for dijet azimuthal decorrelations for azimuthal angles of $\\Delta\\phi_{\\rm dijet} < 2\\pi/3$ between the two jets. We show how the inconsistency arises and how the calculations can be modified to provide more accurate results that exhibit a smaller scale dependence and give a better description of the data than the inconsistent results. We also explain how the quality of the predictions strongly depends on a perceivedly minor detail in the definition of the dijet phase space and give recommendations for future measurements.

  20. Azimuthal inhomogeneity of turbulence structure and its impact on intermittent particle transport in linear magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, T., E-mail: kobayashi.tatsuya@LHD.nifs.ac.jp [National Institute for Fusion Science, Toki 509-5292 (Japan); Inagaki, S.; Sasaki, M.; Nagashima, Y.; Kasuya, N.; Fujisawa, A.; Itoh, S.-I. [Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan); Research Center for Plasma Turbulence, Kyushu University, Kasuga 816-8580 (Japan); Kosuga, Y. [Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan); Institute for Advanced Study, Kyushu University, Fukuoka 812-8581 (Japan); Arakawa, H. [Teikyo University, 6-22 Misakimachi, Omuta 836-8505 (Japan); Yamada, T. [Research Center for Plasma Turbulence, Kyushu University, Kasuga 816-8580 (Japan); Faculty of Arts and Science, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Miwa, Y. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580 (Japan); Itoh, K. [National Institute for Fusion Science, Toki 509-5292 (Japan); Research Center for Plasma Turbulence, Kyushu University, Kasuga 816-8580 (Japan)

    2015-11-15

    Fluctuation component in the turbulence regime is found to be azimuthally localized at a phase of the global coherent modes in a linear magnetized plasma PANTA. Spatial distribution of squared bicoherence is given in the azimuthal cross section as an indicator of nonlinear energy transfer function from the global coherent mode to the turbulence. Squared bicoherence is strong at a phase where the turbulence amplitude is large. As a result of the turbulence localization, time evolution of radial particle flux becomes bursty. Statistical features such as skewness and kurtosis are strongly modified by the localized turbulence component, although contribution to mean particle flux profile is small.

  1. Time Varying Feature Data

    Science.gov (United States)

    Echterhoff, J.; Simonis, I.; Atkinson, R.

    2012-04-01

    The infrastructure to gather, store and access information about our environment is improving and growing rapidly. The increasing amount of information allows us to get a better understanding of the current state of our environment, historical processes and to simulate and predict the future state of the environment. Finer grained spatial and temporal data and more reliable communications make it easier to model dynamic states and ephemeral features. The exchange of information within and across geospatial domains is facilitated through the use of harmonized information models. The Observations & Measurements (O&M) developed through OGC and standardised by ISO is an example of such a cross-domain information model. It is used in many domains, including meteorology, hydrology as well as the emergency management. O&M enables harmonized representation of common metadata that belong to the act of determining the state of a feature property, whether by sensors, simulations or humans. In addition to the resulting feature property value, information such as the result quality but especially the time that the result applies to the feature property can be represented. Temporal metadata is critical to modelling past and future states of a feature. The features, and the semantics of each property, are defined in domain specific Application Schema using the General Feature Model (GFM) from ISO 19109 and usually encoded following ISO 19136. However, at the moment these standards provide only limited support for the representation and handling of time varying feature data. Features like rivers, wildfires or gas plumes have a defined state - for example geographic extent - at any given point in time. To keep track of changes, a more complex model for example using time-series coverages is required. Furthermore, the representation and management of feature property value changes via the service interfaces defined by OGC and ISO - namely: WFS and WCS - would be rather complex

  2. ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Zidan, R; Christopher Fewox, C; Brenda Garcia-Diaz, B; Joshua Gray, J

    2009-01-09

    Hydrogen storage is one of the challenges to be overcome for implementing the ever sought hydrogen economy. Here we report a novel cycle to reversibly form high density hydrogen storage materials such as aluminium hydride. Aluminium hydride (AlH{sub 3}, alane) has a hydrogen storage capacity of 10.1 wt% H{sub 2}, 149 kg H{sub 2}/m{sup 3} volumetric density and can be discharged at low temperatures (< 100 C). However, alane has been precluded from use in hydrogen storage systems because of the lack of practical regeneration methods. The direct hydrogenation of aluminium to form AlH{sub 3} requires over 10{sup 5} bars of hydrogen pressure at room temperature and there are no cost effective synthetic means. Here we show an unprecedented reversible cycle to form alane electrochemically, using alkali metal alanates (e.g. NaAlH{sub 4}, LiAlH{sub 4}) in aprotic solvents. To complete the cycle, the starting alanates can be regenerated by direct hydrogenation of the dehydrided alane and the alkali hydride being the other compound formed in the electrochemical cell. The process of forming NaAlH{sub 4} from NaH and Al is well established in both solid state and solution reactions. The use of adducting Lewis bases is an essential part of this cycle, in the isolation of alane from the mixtures of the electrochemical cell. Alane is isolated as the triethylamine (TEA) adduct and converted to pure, unsolvated alane by heating under vacuum.

  3. ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Fewox, C; Ragaiy Zidan, R; Brenda Garcia-Diaz, B

    2008-12-31

    Hydrogen storage is one of the greatest challenges for implementing the ever sought hydrogen economy. Here we report a novel cycle to reversibly form high density hydrogen storage materials such as aluminium hydride. Aluminium hydride (AlH{sub 3}, alane) has a hydrogen storage capacity of 10.1 wt% H{sub 2}, 149 kg H{sub 2}/m{sup 3} volumetric density and can be discharged at low temperatures (< 100 C). However, alane has been precluded from use in hydrogen storage systems because of the lack of practical regeneration methods; the direct hydrogenation of aluminium to form AlH{sub 3} requires over 10{sup 5} bars of hydrogen pressure at room temperature and there are no cost effective synthetic means. Here we show an unprecedented reversible cycle to form alane electrochemically, using alkali alanates (e.g. NaAlH{sub 4}, LiAlH{sub 4}) in aprotic solvents. To complete the cycle, the starting alanates can be regenerated by direct hydrogenation of the dehydrided alane and the alkali hydride being the other compound formed in the electrochemical cell. The process of forming NaAlH{sub 4} from NaH and Al is well established in both solid state and solution reactions. The use of adducting Lewis bases is an essential part of this cycle, in the isolation of alane from the mixtures of the electrochemical cell. Alane is isolated as the triethylamine (TEA) adduct and converted to pure, unsolvated alane by heating under vacuum.

  4. Effects of Ca additions on some Mg-alloy hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Lupu, D.; Biris, A.; Indrea, E.; Bucur, R.V.

    1983-01-01

    The hydrogenation of the alloy of composition CaMg/sub 1/ /sub 8/Ni/sub 0/ /sub 5/ containing CaMg/sub 2/ and MgNi/sub 2/ shows fast activation kinetics. The Mg/sub 2/Ni phase is observed in the dehydrided samples. The three plateaus on the hydrogen desorption isotherms correspond to the most stable magnesium hydrides observed up to now in Mg-alloy (..delta.. H = 20 to 24 kcal/mol H/sub 2/). The effects of Ca additions on the hydrogen storage capacity and desorption rates of some Mg-rich alloys have been studied. 16 references, 3 figures, 1 table.

  5. Alkyl and Hydride-Olefin Complexes of Niobocene

    NARCIS (Netherlands)

    Klazinga, A.H.; Teuben, J.H.

    1980-01-01

    Reactions of Cp2NbCl2 with RMgCl (R = n-C3H7, i-C3H7, n-C4H9, s-C4H9 and n-C5H11) give niobocene hydride olefin complexes Cp2Nb(H)L (L = C3H6, C4H8 and C5H10). The last step of the reaction probably proceeds via a stereospecific β-H elimination from the monoalkyl species Cp2NbR. Decomposition of n-a

  6. Geoneutrinos and Hydridic Earth (or primordially Hydrogen-Rich Planet)

    CERN Document Server

    Bezrukov, L

    2014-01-01

    Geoneutrino is a new channel of information about geochemical composition of the Earth. We alnalysed here the following problem. What statistics do we need to distinguish between predictions of Bulk Silicate Earth model and Hydridic Earth model for Th/U signal ratio? We obtained the simple formula for estimation of error of Th/U signal ratio. Our calculations show that we need more than $22 kt \\cdot year$ exposition for Gran-Sasso underground laboratory and Sudbury Neutrino Observatory. We need more than $27 kt \\cdot year$ exposition for Kamioka site in the case of stopping of all Japanese nuclear power plants.

  7. Electrochemical process and production of novel complex hydrides

    Science.gov (United States)

    Zidan, Ragaiy

    2013-06-25

    A process of using an electrochemical cell to generate aluminum hydride (AlH.sub.3) is provided. The electrolytic cell uses a polar solvent to solubilize NaAlH.sub.4. The resulting electrochemical process results in the formation of AlH.sub.3. The AlH.sub.3 can be recovered and used as a source of hydrogen for the automotive industry. The resulting spent aluminum can be regenerated into NaAlH.sub.4 as part of a closed loop process of AlH.sub.3 generation.

  8. Comparison between different reactions of group IV hydride with H

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Shaolong; ZHANG; Xuqiang; ZHANG; Qinggang; ZHANG; Yici

    2006-01-01

    The four-dimensional time-dependent quantum dynamics calculations for reactions of group IV hydride with H are carried out by employing the semirigid vibrating rotor target model and the time-dependent wave packet method. The reaction possibility, cross section and rate constants for reactions (H+SiH4 and H+GeH4) in different initial vibrational and rotational states are obtained. The common feature for such kind of reaction process is summarized. The theoretical result is consistent with available measurement, which indicates the credibility of this theory and the potential energy surface.

  9. Equilibrium composition for the reaction of plutonium hydride with air

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    There are six independent constituents with 4 chemical elements, i.e. PuH2.7(s), PuN(s), Pu2O3(s), N2, O2 and H2, therefore , the system described involves of 2 independent reactions ,both those of the experimental, which indicates that the chemical equilibrium is nearly completely approached. Therefore, it is believed that the reaction rate of plutonium hydride with air is extremely rapid. The present paper has briefly discussed the simultaneous reactions and its thermodynamic coupling effect.

  10. Bipolar Nickel-Metal Hydride Battery Development Project

    Science.gov (United States)

    Cole, John H.

    1999-01-01

    This paper reviews the development of the Electro Energy, Inc.'s bipolar nickel metal hydride battery. The advantages of the design are that each cell is individually sealed, and that there are no external cell terminals, no electrode current collectors, it is compatible with plastic bonded electrodes, adaptable to heat transfer fins, scalable to large area, capacity and high voltage. The design will allow for automated flexible manufacturing, improved energy and power density and lower cost. The development and testing of the battery's component are described. Graphic presentation of the results of many of the tests are included.

  11. Research in Nickel/Metal Hydride Batteries 2016

    Directory of Open Access Journals (Sweden)

    Kwo-Hsiung Young

    2016-10-01

    Full Text Available Nineteen papers focusing on recent research investigations in the field of nickel/metal hydride (Ni/MH batteries have been selected for this Special Issue of Batteries. These papers summarize the joint efforts in Ni/MH battery research from BASF, Wayne State University, the National Institute of Standards and Technology, Michigan State University, and FDK during 2015–2016 through reviews of basic operational concepts, previous academic publications, issued US Patent and filed Japan Patent Applications, descriptions of current research results in advanced components and cell constructions, and projections of future works.

  12. Formation of noble-gas hydrides and decay of solvated protons revisited: diffusion-controlled reactions and hydrogen atom losses in solid noble gases.

    Science.gov (United States)

    Tanskanen, Hanna; Khriachtchev, Leonid; Lignell, Antti; Räsänen, Markku; Johansson, Susanna; Khyzhniy, Ivan; Savchenko, Elena

    2008-02-07

    UV photolysis and annealing of C2H2/Xe, C2H2/Xe/Kr, and HBr/Xe matrices lead to complicated photochemical processes and reactions. The dominating products in these experiments are noble-gas hydrides with general formula HNgY (Ng = noble-gas atom, Y = electronegative fragment). We concentrate on distinguishing the local and global mobility and losses of H atoms, barriers of the reactions, and the decay of solvated protons. Different deposition temperatures change the amount of lattice imperfections and thus the amount of traps for H atoms. The averaged distance between reacting species influencing the reaction kinetics is controlled by varying the precursor concentration. A number of solid-state processes connected to the formation of noble-gas hydrides and decay of solvated protons are discussed using a simple kinetic model. The most efficient formation of noble-gas hydrides is connected with global (long-range) mobility of H atoms leading to the H + Xe + Y reaction. The highest concentration of noble-gas hydrides was obtained in matrices of highest optical quality, which probably have the lowest concentration of defects and H-atom losses. In matrices with high amount of geometrical imperfections, the product formation is inefficient and dominated by a local (short-range) process. The decay of solvated protons is rather local than a global process, which is different from the formation of noble-gas molecules. However, the present data do not allow distinguishing local proton and electron mobilities. Our previous results indicate that these are electrons which move to positively-charged centers and neutralize them. It is believed that the image obtained here for solid xenon is applicable to solid krypton whereas the case of argon deserves special attention.

  13. Development of a component design tool for metal hydride heat pumps

    Science.gov (United States)

    Waters, Essene L.

    Given current demands for more efficient and environmentally friendly energy sources, hydrogen based energy systems are an increasingly popular field of interest. Within the field, metal hydrides have become a prominent focus of research due to their large hydrogen storage capacity and relative system simplicity and safety. Metal hydride heat pumps constitute one such application, in which heat and hydrogen are transferred to and from metal hydrides. While a significant amount of work has been done to study such systems, the scope of materials selection has been quite limited. Typical studies compare only a few metal hydride materials and provide limited justification for the choice of those few. In this work, a metal hydride component design tool has been developed to enable the targeted down-selection of an extensive database of metal hydrides to identify the most promising materials for use in metal hydride thermal systems. The material database contains over 300 metal hydrides with various physical and thermodynamic properties included for each material. Sub-models for equilibrium pressure, thermophysical data, and default properties are used to predict the behavior of each material within the given system. For a given thermal system, this tool can be used to identify optimal materials out of over 100,000 possible hydride combinations. The selection tool described herein has been applied to a stationary combined heat and power system containing a high-temperature proton exchange membrane (PEM) fuel cell, a hot water tank, and two metal hydride beds used as a heat pump. A variety of factors can be used to select materials including efficiency, maximum and minimum system pressures, pressure difference, coefficient of performance (COP), and COP sensitivity. The targeted down-selection of metal hydrides for this system focuses on the system's COP for each potential pair. The values of COP and COP sensitivity have been used to identify pairs of highest interest for

  14. Identification and characterization of a new zirconium hydride; Identification et caracterisation d'un nouvel hydrure de zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhao; Morniroli, J.P.; Legris, A.; Thuinet, L. [Universite des Sciences et Technologies de Lille, USTL, ENSCL, CNRS, 59 - Villeneuve d' Ascq (France); Zhao, Zhao; Blat-Yrieix, M.; Ambard, A.; Legras, L. [Electricite de France (EDF/RD), Centre des Renardieres, 77 - Moret sur Loing (France); Kihn, Y. [CEMES-CNRS, 31 - Toulouse (France)

    2007-07-01

    A study of hydrides characterization has been carried out in using the transmission electron microscopy technique. It has revealed the presence of small hydrides of acicular form whose length does not exceed 500 nm, among the zircaloy-4 samples hydrided by cathodic way. The electronic diffraction has shown that these small hydrides have a crystallographic structure different of those of the hydrides phases already index in literature. A more complete identification study has then been carried out. In combining the different electronic microscopy techniques (precession electronic micro diffraction and EELS) with ab initio calculations, a new hydride phase has been identified. It is called hydride {zeta}, is of trigonal structure with lattice parameters a{sub {zeta}} = a{sub {alpha}}{sub Zr} = 0.33 nm and c{sub {zeta}} 2c{sub {alpha}}{sub Zr} = 1.029 nm, its spatial group being P3m1. (O.M.)

  15. A fast forward algorithm for real-time geosteering of azimuthal gamma-ray logging.

    Science.gov (United States)

    Qin, Zhen; Pan, Heping; Wang, Zhonghao; Wang, Bintao; Huang, Ke; Liu, Shaohua; Li, Gang; Amara Konaté, Ahmed; Fang, Sinan

    2017-05-01

    Geosteering is an effective method to increase the reservoir drilling rate in horizontal wells. Based on the features of an azimuthal gamma-ray logging tool and strata spatial location, a fast forward calculation method of azimuthal gamma-ray logging is deduced by using the natural gamma ray distribution equation in formation. The response characteristics of azimuthal gamma-ray logging while drilling in the layered formation models with different thickness and position are simulated and summarized by using the method. The result indicates that the method calculates quickly, and when the tool nears a boundary, the method can be used to identify the boundary and determine the distance from the logging tool to the boundary in time. Additionally, the formation parameters of the algorithm in the field can be determined after a simple method is proposed based on the information of an offset well. Therefore, the forward method can be used for geosteering in the field. A field example validates that the forward method can be used to determine the distance from the azimuthal gamma-ray logging tool to the boundary for geosteering in real-time.

  16. Back azimuth constrained double-difference seismic location and tomography for downhole microseismic monitoring

    Science.gov (United States)

    Chen, Yukuan; Zhang, Haijiang; Miao, Yuanyuan; Zhang, Yinsheng; Liu, Qiang

    2017-03-01

    We have developed a new seismic tomography method, back azimuth constrained double-difference (DD) seismic tomography, which is suitable for downhole microseismic monitoring of hydraulic fracturing. The new method simultaneously locates microseismic events and determines three-dimensional (3D) Vp and Vs models for the fracturing zone using differential arrival times from pairs of events and event back azimuths in addition to absolute arrival times. Compared to the existing DD location and tomography method, our method incorporates back azimuth information to better constrain microseismic event locations in the case of poor spatial station coverage such as the linear downhole seismic array generally used for microseismic monitoring. By incorporating the relative arrival time and back azimuth information of events, the extended DD method can provide better relative event locations, and thus can better characterize the fracture distribution. In addition to microseismic locations, seismic velocity anomalies determined around the fracturing zone may also provide valuable information for fracture development. Due to the existence of fractures and fluids, the seismic velocity is expected to be lower in the fractured zone compared to the surrounding regions. Therefore the area of low seismic velocity anomaly may be used as a proxy for the stimulated reservoir volume. We have applied the new method to a downhole microseismic dataset from shale gas hydraulic fracturing. The microseismic events are more accurately relocated than the conventional grid search location method, and they are generally associated with low velocity anomalies.

  17. Azimuthal correlations in Pb--Pb and pp collisions measured with the ALICE detector

    DEFF Research Database (Denmark)

    Zhou, You; Collaboration, for the ALICE

    2012-01-01

    We present results from the measurements of azimuthal correlations of charged particles in $\\sqrt{s_{_{NN}}}$ = 2.76 TeV Pb--Pb collisions and $\\sqrt{s_{_{NN}}}$ = 7 TeV pp collisions. In addition, the comparison of the experimental measurements in pp collisions with those from Pythia and Phojet...

  18. Principles of azimuthal correlation measurement of J/psi with charged hadrons

    CERN Multimedia

    Maire, Antonin

    2012-01-01

    Schematic illustration of measurement variables in the azimuthal J/psi-hadron correlation measurement. The z-axis perpendicular to the x-y-plane corresponds to the beam axis in the experiment. The reconstructed e+e- pairs are only identifiable as J/psi mesons on a statistical basis.

  19. Wide-azimuth angle gathers for anisotropic wave-equation migration

    KAUST Repository

    Sava, Paul C.

    2012-10-15

    Extended common-image-point gathers (CIP) constructed by wide-azimuth TI wave-equation migration contain all the necessary information for angle decomposition as a function of the reflection and azimuth angles at selected locations in the subsurface. The aperture and azimuth angles are derived from the extended images using analytic relations between the space- and time-lag extensions using information which is already available at the time of migration, i.e. the anisotropic model parameters. CIPs are cheap to compute because they can be distributed in the image at the most relevant positions, as indicated by the geologic structure. If the reflector dip is known at the CIP locations, then the computational cost can be reduced by evaluating only two components of the space-lag vector. The transformation from extended images to angle gathers is a planar Radon transform which depends on the local medium parameters. This transformation allows us to separate all illumination directions for a given experiment, or between different experiments. We do not need to decompose the reconstructed wavefields or to choose the most energetic directions for decomposition. Applications of the method include illumination studies in complex areas where ray-based methods fail, and assuming that the subsurface illumination is sufficiently dense, the study of amplitude variation with aperture and azimuth angles. © 2012 European Association of Geoscientists & Engineers.

  20. Azimuthal angular correlations of D mesons and charged particles with the ALICE detector at the LHC

    NARCIS (Netherlands)

    Bjelogrlic, S.

    2016-01-01

    The thesis presents the results of the analysis of azimuthal angular correlations of D mesons and charged particles with the ALICE detector, in pp and p-Pb collisions at center-of mass energies of 7 and 5.02 TeV respectively. The measurements have been performed differentially as function of the tra

  1. A new method to determine the energy of vanishing flow, using particle-particle azimuthal correlations

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Institute of Atomic Physics, Bucharest (Romania); Angelique, J.C.; Bizard, G.; Brou, R.; Cussol, D. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, G.; Cabot, C. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Cassagnou, Y. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Crema, E. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Sao Paulo Univ., SP (Brazil). Inst. de Fisica; El Masri, Y. [Louvain Univ., Louvain-la-Neuve (Belgium). Unite de Physique Nucleaire; and others

    1996-09-01

    Measuring the in-plane flow parameter appears to be a promising method to gain information on the equation of state of nuclear matter. A new method, based on particle-particle azimuthal correlations is proposed. This method does not require the knowledge of the reaction plane. The collisions Zn+Ni and Ar+Al are presented as an example. (K.A.).

  2. Break up of the azimuthal symmetry of higher order fiber modes

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten

    2014-01-01

    We investigate Bessel-like modes guided in a double cladding fiber where the outer cladding is an aircladding. For very high order LP0 X-modes, the azimuthal symmetry is broken and the mode is no longer linearly polarized. This is observed experimentally and confirmed numerically. The effect...

  3. Azimuthal spectrum after parametric down-convertion with radial degrees of freedom

    CSIR Research Space (South Africa)

    Zhang, Y

    2014-08-01

    Full Text Available Considering the quantum state produced in type I spontaneous parametric down-conversion with collinear, degenerate signal and idler beams, and a Gaussian pump, we show that the azimuthal Schmidt number in the Laguerre-Gaussian (LG) basis increases...

  4. Wide-azimuth angle-domain imaging for anisotropic reverse-time migration

    KAUST Repository

    Sava, Paul C.

    2011-01-01

    Extended common-image-point gathers (CIP) constructed by wide-azimuth TI wave-equation migration contain all the necessary information for angle decomposition as a function of the reflection and azimuth angles at selected locations in the subsurface. The reflection and azimuth angles are derived from the extended images using analytic relations between the space-lag and time-lag extensions. This post-imaging decomposition requires only information which is already available at the time of migration, i.e. the model parameters and the tilt angles of the TI medium. The transformation amounts to a linear Radon transform applied to the CIPs obtained after the application of the extended imaging condition. If information about the reflector dip is available at the CIP locations, then only two components of the space-lag vectors are required, thus reducing computational cost and increasing the affordability of the method. This efficient angle decomposition method is suitable for wide-azimuth imaging in anisotropic media with arbitrary orientation of the symmetry plane. © 2011 Society of Exploration Geophysicists.

  5. INVESTIGATION OF POLAR AND AZIMUTHAL DISTRIBUTIONS OF SUBTHRESHOLD PIONS AT INTERMEDIATE ENERGIES

    NARCIS (Netherlands)

    SCHUBERT, A; HOLZMANN, R; HLAVAC, S; KULESSA, R; NIEBUR, W; SIMON, RS; LAUTRIDOU, P; LEFEVRE, F; MARQUES, M; MATULEWICZ, T; MITTIG, W; OSTENDORF, RW; ROUSSELCHOMAZ, P; SCHUTZ, Y; LOHNER, H; VANPOL, JHG; SIEMSSEN, RH; WILSCHUT, HW; BALLESTER, F; DIAZ, J; MARIN, A; MARTINEZ, G; METAG, [No Value; NOVOTNY, R; WAGNER, [No Value; QUEBERT, J

    1994-01-01

    We present data on pi0 emission coincident with projectile-like fragments from Ar-36 + Au-197 and Ar-36 + C-12 reactions at 95 MeV/u. The pion polar and azimuthal distributions, obtained for different impact parameters, are interpreted in terms of strong final-state interactions. We propose to explo

  6. RADIAL AND AZIMUTHAL OSCILLATIONS OF HALO CORONAL MASS EJECTIONS IN THE SUN

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Harim; Moon, Y.-J.; Nakariakov, V. M., E-mail: harim@khu.ac.kr, E-mail: moonyj@khu.ac.kr, E-mail: V.Nakariakov@warwick.ac.uk [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of)

    2015-04-10

    We present the first observational detection of radial and azimuthal oscillations in full halo coronal mass ejections (HCMEs). We analyze nine HCMEs well-observed by the Large Angle and Spectrometric Coronagraph (LASCO) from 2011 February to June. Using the LASCO C3 running difference images, we estimated the instantaneous apparent speeds of the HCMEs in different radial directions from the solar disk center. We find that the development of all these HCMEs is accompanied by quasi-periodic variations of the instantaneous radial velocity with the periods ranging from 24 to 48 minutes. The amplitudes of the instant speed variations reach about a half of the projected speeds. The amplitudes are found to anti-correlate with the periods and correlate with the HCME speed, indicating the nonlinear nature of the process. The oscillations have a clear azimuthal structure in the heliocentric polar coordinate system. The oscillations in seven events are found to be associated with distinct azimuthal wave modes with the azimuthal wave number m = 1 for six events and m = 2 for one event. The polarization of the oscillations in these seven HCMEs is broadly consistent with those of their position angles with the mean difference of 43°. The oscillations may be connected with natural oscillations of the plasmoids around a dynamical equilibrium, or self-oscillatory processes, e.g., the periodic shedding of Alfvénic vortices. Our results indicate the need for an advanced theory of oscillatory processes in coronal mass ejections.

  7. Inclusive jet cross-sections and dijet azimuthal decorrelations with D0

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, Raimund; /Munich U.

    2006-01-01

    We present a preliminary measurement of the inclusive jet cross-sections based on an integrated luminosity of 378 pb{sup -1} acquired with the D0 detector between 2002 and 2004 at a center of mass energy of {radical}s = 1.96 TeV and a measurement of azimuthal dijet decorrelations based on an integrated luminosity of 150 pb{sup -1}. The cross section measurements are based on an iterative cone algorithm with a cone size of R = 0.7. They are performed in two rapidity bins between 0.0 and 0.8. The measurements are in good agreement with next to leading order calculations. The azimuthal angle between the two leading jets is sensitive to higher order QCD effects. The measurement of dijet azimuthal decorrelations therefore probes these effects without explicitly reconstructing more than two jets. Except for large azimuthal angles where soft effects are important the measurements are well described by the next to leading order perturbation theory.

  8. In situ spatiotemporal measurements of the detailed azimuthal substructure of the substorm current wedge

    DEFF Research Database (Denmark)

    Forsyth, C.; Fazakerley, A. N.; Rae, I. J.

    2014-01-01

    perigee passes of the Cluster 1 and 4 spacecraft during a substorm on 15 January 2010, in conjunction with ground-based observations, to examine the spatial structuring and temporal variability of the SCW. At this time, the spacecraft traveled east-west azimuthally above the auroral region. We show...

  9. ;Study of secondary hydriding at high temperature in zirconium based nuclear fuel cladding tubes by coupling information from neutron radiography/tomography, electron probe micro analysis, micro elastic recoil detection analysis and laser induced breakdown spectroscopy microprobe

    Science.gov (United States)

    Brachet, Jean-Christophe; Hamon, Didier; Le Saux, Matthieu; Vandenberghe, Valérie; Toffolon-Masclet, Caroline; Rouesne, Elodie; Urvoy, Stéphane; Béchade, Jean-Luc; Raepsaet, Caroline; Lacour, Jean-Luc; Bayon, Guy; Ott, Frédéric

    2017-05-01

    This paper gives an overview of a multi-scale experimental study of the secondary hydriding phenomena that can occur in nuclear fuel cladding materials exposed to steam at high temperature (HT) after having burst (loss-of-coolant accident conditions). By coupling information from several facilities, including neutron radiography/tomography, electron probe micro analysis, micro elastic recoil detection analysis and micro laser induced breakdown spectroscopy, it was possible to map quantitatively, at different scales, the distribution of oxygen and hydrogen within M5™ clad segments having experienced ballooning and burst at HT followed by steam oxidation at 1100 and 1200 °C and final direct water quenching down to room temperature. The results were very reproducible and it was confirmed that internal oxidation and secondary hydriding at HT of a cladding after burst can lead to strong axial and azimuthal gradients of hydrogen and oxygen concentrations, reaching 3000-4000 wt ppm and 1.0-1.2 wt% respectively within the β phase layer for the investigated conditions. Consistent with thermodynamic and kinetics considerations, oxygen diffusion into the prior-β layer was enhanced in the regions highly enriched in hydrogen, where the α(O) phase layer is thinner and the prior-β layer thicker. Finally the induced post-quenching hardening of the prior-β layer was mainly related to the local oxygen enrichment. Hardening directly induced by hydrogen was much less significant.

  10. varying elastic parameters distributions

    KAUST Repository

    Moussawi, Ali

    2014-12-01

    The experimental identication of mechanical properties is crucial in mechanics for understanding material behavior and for the development of numerical models. Classical identi cation procedures employ standard shaped specimens, assume that the mechanical elds in the object are homogeneous, and recover global properties. Thus, multiple tests are required for full characterization of a heterogeneous object, leading to a time consuming and costly process. The development of non-contact, full- eld measurement techniques from which complex kinematic elds can be recorded has opened the door to a new way of thinking. From the identi cation point of view, suitable methods can be used to process these complex kinematic elds in order to recover multiple spatially varying parameters through one test or a few tests. The requirement is the development of identi cation techniques that can process these complex experimental data. This thesis introduces a novel identi cation technique called the constitutive compatibility method. The key idea is to de ne stresses as compatible with the observed kinematic eld through the chosen class of constitutive equation, making possible the uncoupling of the identi cation of stress from the identi cation of the material parameters. This uncoupling leads to parametrized solutions in cases where 5 the solution is non-unique (due to unknown traction boundary conditions) as demonstrated on 2D numerical examples. First the theory is outlined and the method is demonstrated in 2D applications. Second, the method is implemented within a domain decomposition framework in order to reduce the cost for processing very large problems. Finally, it is extended to 3D numerical examples. Promising results are shown for 2D and 3D problems.

  11. Lab-size rechargeable metal hydride-air cells

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wei-Kang; Noreus, Dag [Department of Materials and Enviromental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm (Sweden)

    2010-09-01

    Lab-size rechargeable metal hydride-air (MH-air) cells with a gas management device were designed in order to minimize the loss of electrolyte. An AB{sub 5}-type hydrogen storage alloy was used as anode materials of the MH-air. The thickness of the metal hydride electrodes was in the range of 3.0-3.4 mm. Porous carbon-based air electrodes with Ag{sub 2}O catalysts were used as bi-functional electrodes for oxygen reduction and generation. The electrodes were first examined in half-cells to evaluate their performance and then assembled into one MH-air cell. The results showed the good cycling stability of the rechargeable MH-air cell with a capacity of 1990 mAh. The discharge voltage was 0.69 V at 0.05-0.1 C. The charge efficiency was about 90%. The specific and volumetric energy densities were about 95Wh kg{sup -1} and 140 Wh L{sup -1}, respectively. (author)

  12. Thermodynamic Calculation on the Formation of Titanium Hydride

    Institute of Scientific and Technical Information of China (English)

    Jing-wei Zhao; Hua Ding; Xue-feng Tian; Wen-juan Zhao; Hong-liang Hou

    2008-01-01

    A modified Miedema model, using interrelationship among the basic properties of elements Ti and H, is employed to calculate the standard enthalpy of formation of titanium hydride TiHx (1≤x≤2). Based on Debye theories of solid thermal capacity, the vibrational entropy, as well as electronic entropy, is acquired by quantum mechanics and statistic thermodynamics methods, and a new approach is presented to calculate the standard entropy of formation of Till2. The values of standard enthalpy of formation of TiHx decrease linearly with increase of x. The calculated results of standard enthalpy, entropy, and free energy of forma- tion of Till2 at 298.16 K are -142.39 kJ/mol, -143.0 J/(mol-K) and -99.75 k J/tool, respectively, which is consistent with the previously-reported data obtained by either experimental or theoretical calculation methods. The results show that the thermodynamic model for titanium hydride is reasonable.

  13. Effects of Alkaline Pre-Etching to Metal Hydride Alloys

    Directory of Open Access Journals (Sweden)

    Tiejun Meng

    2017-10-01

    Full Text Available The responses of one AB5, two AB2, four A2B7, and one C14-related body-centered-cubic (BCC metal hydrides to an alkaline-etch (45% KOH at 110 °C for 2 h were studied by internal resistance, X-ray diffraction, scanning electron microscope, inductively coupled plasma, and AC impedance measurements. Results show that while the etched rare earth–based AB5 and A2B7 alloys surfaces are covered with hydroxide/oxide (weight gain, the transition metal–based AB2 and BCC-C14 alloys surfaces are corroded and leach into electrolyte (weight loss. The C14-predominated AB2, La-only A2B7, and Sm-based A2B7 showed the most reduction in the internal resistance with the alkaline-etch process. Etched A2B7 alloys with high La-contents exhibited the lowest internal resistance and are suggested for use in the high-power application of nickel/metal hydride batteries.

  14. Gallium Nitride Nanowires Grown by Hydride Vapor Phase Epitaxy

    Institute of Scientific and Technical Information of China (English)

    LIU Zhan-Hui; XIU Xiang-Qan; YAN Huai-Yue; ZHANG Rong; XIE Zi-Li; HAN Ping; SHI Yi; ZHENG You-Dou

    2011-01-01

    @@ GaN nanowires are grown by hydride vapor phase epitaxy using nickel as a catalyst.The properties of the obtained GaN nanowires are characterized by scanning and transmission electron microscopy,electron diffraction,roomtemperature photoluminescence and energy dispersive spectroscopy.The results show that the nanowires are wurtzite single crystals growing along the[0001]direction and a redshift in the photoluminescence is observed due to a superposition of several effects.The Raman spectra are close to those of the bulk GaN and the significantly broadening of those modes indicates the phonon confinement effects associated with the nanoscale dimensions of the system.%GaN nanowires are grown by hydride vapor phase epitaxy using nickel as a catalyst. The properties of the obtained GaN nanowires are characterized by scanning and transmission electron microscopy, electron diffraction, room-temperature photoluminescence and energy dispersive spectroscopy. The results show that the nanowires are wurtzite single crystals growing along the [0001] direction and a redshift in the photoluminescence is observed due to a superposition of several effects. The Raman spectra are close to those of the bulk GaN and the significantly broadening of those modes indicates the phonon confinement effects associated with the nanoscale dimensions of the system.

  15. Measurement of nuclear fuel pin hydriding utilizing epithermal neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.H. [Univ. of Missouri, Columbia, MO (United States); Farkas, D.M.; Lutz, D.R. [General Electric Co., Pleasanton, CA (United States)

    1996-12-31

    The measurement of hydrogen or zirconium hydriding in fuel cladding has long been of interest to the nuclear power industry. The detection of this hydrogen currently requires either destructive analysis (with sensitivities down to 1 {mu}g/g) or nondestructive thermal neutron radiography (with sensitivities on the order of a few weight percent). The detection of hydrogen in metals can also be determined by measuring the slowing down of neutrons as they collide and rapidly lose energy via scattering with hydrogen. This phenomenon is the basis for the {open_quotes}notched neutron spectrum{close_quotes} technique, also referred to as the Hysen method. This technique has been improved with the {open_quotes}modified{close_quotes} notched neutron spectrum technique that has demonstrated detection of hydrogen below 1 {mu}g/g in steel. The technique is nondestructive and can be used on radioactive materials. It is proposed that this technique be applied to the measurement of hydriding in zirconium fuel pins. This paper summarizes a method for such measurements.

  16. Interstellar chemistry of nitrogen hydrides in dark clouds

    CERN Document Server

    Gal, Romane Le; Faure, Alexandre; Forêts, Guillaume Pineau des; Rist, Claire; Maret, Sébastien

    2013-01-01

    The aim of the present work is to perform a comprehensive analysis of the interstellar chemistry of nitrogen, focussing on the gas-phase formation of the smallest polyatomic species and in particular nitrogen hydrides. We present a new chemical network in which the kinetic rates of critical reactions have been updated based on recent experimental and theoretical studies, including nuclear spin branching ratios. Our network thus treats the different spin symmetries of the nitrogen hydrides self-consistently together with the ortho and para forms of molecular hydrogen. This new network is used to model the time evolution of the chemical abundances in dark cloud conditions. The steady-state results are analysed, with special emphasis on the influence of the overall amounts of carbon, oxygen, and sulphur. Our calculations are also compared with Herschel/HIFI observations of NH, NH$_2$, and NH$_3$ detected towards the external envelope of the protostar IRAS 16293-2422. The observed abundances and abundance ratios ...

  17. Superconductive "sodalite"-like clathrate calcium hydride at high pressures

    CERN Document Server

    Wang, Hui; Tanaka, Kaori; Iitaka, Toshiaki; Ma, Yanming

    2012-01-01

    Hydrogen-rich compounds hold promise as high-temperature superconductors under high pressures. Recent theoretical hydride structures on achieving high-pressure superconductivity are composed mainly of H2 fragments. Through a systematic investigation of Ca hydrides with different hydrogen contents using particle-swam optimization structural search, we show that in the stoichiometry CaH6 a body-centred cubic structure with hydrogen that forms unusual "sodalite" cages containing enclathrated Ca stabilizes above pressure 150 GPa. The stability of this structure is derived from the acceptance by two H2 of electrons donated by Ca forming a "H4" unit as the building block in the construction of the 3-dimensional sodalite cage. This unique structure has a partial occupation of the degenerated orbitals at the zone centre. The resultant dynamic Jahn-Teller effect helps to enhance electron-phonon coupling and leads to superconductivity of CaH6. A superconducting critical temperature (Tc) of 220-235 K at 150 GPa obtained...

  18. Electronic structure of the palladium hydride studied by compton scattering

    CERN Document Server

    Mizusaki, S; Yamaguchi, M; Hiraoka, N; Itou, M; Sakurai, Y

    2003-01-01

    The hydrogen-induced changes in the electronic structure of Pd have been investigated by Compton scattering experiments associated with theoretical calculations. Compton profiles (CPs) of single crystal of Pd and beta phase hydride PdH sub x (x=0.62-0.74) have been measured along the [100], [110] and [111] directions with a momentum resolution of 0.14-0.17 atomic units using 115 keV x-rays. The theoretical Compton profiles have been calculated from the wavefunctions obtained utilizing the full potential linearized augmented plane wave method within the local density approximation for Pd and stoichiometric PdH. The experimental and the theoretical results agreed well with respect to the difference in the CPs between PdH sub x and Pd, and the anisotropy in the CPs of Pd or PdH sub x. This study provides lines of evidence that upon hydride formation the lowest valance band of Pd is largely modified due to hybridization with H 1s-orbitals and the Fermi energy is raised into the sp-band. (author)

  19. Electronic Principles of Hydrogen Incorporation and Dynamics in Metal Hydrides

    Directory of Open Access Journals (Sweden)

    Ljiljana Matović

    2012-08-01

    Full Text Available An approach to various metal hydrides based on electronic principles is presented. The effective medium theory (EMT is used to illustrate fundamental aspects of metal-hydrogen interaction and clarify the most important processes taking place during the interaction. The elaboration is extended using the numerous existing results of experiment and calculations, as well as using some new material. In particular, the absorption/desorption of H in the Mg/MgH2 system is analyzed in detail, and all relevant initial structures and processes explained. Reasons for the high stability and slow sorption in this system are noted, and possible solutions proposed. The role of the transition-metal impurities in MgH2 is briefly discussed, and some interesting phenomena, observed in complex intermetallic compounds, are mentioned. The principle mechanism governing the Li-amide/imide transformation is also discussed. Latterly, some perspectives for the metal-hydrides investigation from the electronic point of view are elucidated.

  20. ACCEPTABILITY ENVELOPE FOR METAL HYDRIDE-BASED HYDROGEN STORAGE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B.; Corgnale, C.; Tamburello, D.; Garrison, S.; Anton, D.

    2011-07-18

    The design and evaluation of media based hydrogen storage systems requires the use of detailed numerical models and experimental studies, with significant amount of time and monetary investment. Thus a scoping tool, referred to as the Acceptability Envelope, was developed to screen preliminary candidate media and storage vessel designs, identifying the range of chemical, physical and geometrical parameters for the coupled media and storage vessel system that allow it to meet performance targets. The model which underpins the analysis allows simplifying the storage system, thus resulting in one input-one output scheme, by grouping of selected quantities. Two cases have been analyzed and results are presented here. In the first application the DOE technical targets (Year 2010, Year 2015 and Ultimate) are used to determine the range of parameters required for the metal hydride media and storage vessel. In the second case the most promising metal hydrides available are compared, highlighting the potential of storage systems, utilizing them, to achieve 40% of the 2010 DOE technical target. Results show that systems based on Li-Mg media have the best potential to attain these performance targets.

  1. A deformation and thermodynamic model for hydride precipitation kinetics in spent fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Stout, R.B.

    1989-10-01

    Hydrogen is contained in the Zircaloy cladding of spent fuel rods from nuclear reactors. All the spent fuel rods placed in a nuclear waste repository will have a temperature history that decreases toward ambient; and as a result, most all of the hydrogen in the Zircaloy will eventually precipitate as zirconium hydride platelets. A model for the density of hydride platelets is a necessary sub-part for predicting Zircaloy cladding failure rate in a nuclear waste repository. A model is developed to describe statistically the hydride platelet density, and the density function includes the orientation as a physical attribute. The model applies concepts from statistical mechanics to derive probable deformation and thermodynamic functionals for cladding material response that depend explicitly on the hydride platelet density function. From this model, hydride precipitation kinetics depend on a thermodynamic potential for hydride density change and on the inner product of a stress tensor and a tensor measure for the incremental volume change due to hydride platelets. The development of a failure response model for Zircaloy cladding exposed to the expected conditions in a nuclear waste repository is supported by the US DOE Yucca Mountain Project. 19 refs., 3 figs.

  2. [Investigation of enhancing effect for hydride generation-atomic fluorescence of transition metal elements].

    Science.gov (United States)

    Sun, Han-Wen; Suo, Ran

    2008-11-01

    A mechanism of hydride generation based on disassembly reaction of hydrogen-transferred interim state [M(BH4)m]* was developed by investigating the effect of reaction medium acidity on hydride generation. The effects of Co2+ and Ni2+, phenanthroline and 8-hydroxyquinoline on hydride generation-atomic fluorescence signals of Zn, Cd, Cu and Ni were studied, respectively, and their enhancing mechnism was discussed. The enhancing effect Co2+ and Ni2+ on the fluorescence signals of Zn and Cd was due to the increase in transmission efficiency of hydride of Zn and Cd. There was a synergic enhancing effect between phenanthroline or 8-hydroxyquinoline and Co2+ on the fluorescence signals of Zn and Cd, however no synergic enhancing effect between phenanthroline and 8-hydroxyquinoline on the fluorescence signals of Zn and Cd. The simulative action of cationic surfactant, anion surfactant and non-ionic surfactant surfactant to hydride generation was investigated. It is shown that both cationic surfactant and non-ionic surfactant have obvious enhancing effect on the fluorescence signals of analytes because of the decrease in surface tension of reaction solution. The release characteristics of hydride from the absorption solution containing surfactant was ulteriorly examined by using graphite furnace atomic absorption spectrometry, and the mechanism of enhancing effect of surfactant on hydride generation and transmission was proposed.

  3. Main Group Lewis Acid-Mediated Transformations of Transition-Metal Hydride Complexes.

    Science.gov (United States)

    Maity, Ayan; Teets, Thomas S

    2016-08-10

    This Review highlights stoichiometric reactions and elementary steps of catalytic reactions involving cooperative participation of transition-metal hydrides and main group Lewis acids. Included are reactions where the transition-metal hydride acts as a reactant as well as transformations that form the metal hydride as a product. This Review is divided by reaction type, illustrating the diverse roles that Lewis acids can play in mediating transformations involving transition-metal hydrides as either reactants or products. We begin with a discussion of reactions where metal hydrides form direct adducts with Lewis acids, elaborating the structure and dynamics of the products of these reactions. The bulk of this Review focuses on reactions where the transition metal and Lewis acid act in cooperation, and includes sections on carbonyl reduction, H2 activation, and hydride elimination reactions, all of which can be promoted by Lewis acids. Also included is a section on Lewis acid-base secondary coordination sphere interactions, which can influence the reactivity of hydrides. Work from the past 50 years is included, but the majority of this Review focuses on research from the past decade, with the intent of showcasing the rapid emergence of this field and the potential for further development into the future.

  4. Insertion of Group 12-16 Hydrides into NHCs: A Theoretical Investigation.

    Science.gov (United States)

    Iversen, Kalon J; Dutton, Jason L; Wilson, David

    2017-03-06

    The endocyclic ring expansion of N-heterocyclic carbene (NHC) rings by transition metal (Group 12) and main group (Group 13-16) element hydrides has been investigated in a computational study. In addition to previously reported insertion reactivity with Si, B, Be and Zn, similar reactivity is predicted to be feasible for heavier group 13 elements (Al, Ga, In, Tl), with the reaction barriers for Al-Tl calculated to be lower than for boron. Insertion is not expected with group 15-16 element hydrides, as the initial adduct formation is thermodynamically unfavourable. The reaction pathway with group 12 hydrides is calculated to be more favourable with two NHCs rather than a single NHC (analogous to Be), however hydride ring insertion with metal dihydrides is not feasible, but rather a reduced NHC is thermodynamically favoured. For group 14, ring-insertion reactivity is predicted to be feasible with the heavier dihydrides. Trends in reactivity of element hydrides may be related to the protic or hydridic character of the element hydrides.

  5. Multiparticle azimuthal correlations in p -Pb and Pb-Pb collisions at the CERN Large Hadron Collider

    NARCIS (Netherlands)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Belmont, R.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.|info:eu-repo/dai/nl/371577810; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.|info:eu-repo/dai/nl/371578248; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.|info:eu-repo/dai/nl/355079615; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Böhmer, F. V.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.|info:eu-repo/dai/nl/070139032; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.|info:eu-repo/dai/nl/411885812; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Casula, E. A R; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.|info:eu-repo/dai/nl/411888056; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; De Caro, A.; De Cataldo, G.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Rooij, R.|info:eu-repo/dai/nl/315888644; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, O.; Dobrin, A.|info:eu-repo/dai/nl/372618715; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dørheim, S.; Dubey, A. K.; Dubla, A.|info:eu-repo/dai/nl/355502488; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Hilden, T. E.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Esposito, M.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grelli, A.|info:eu-repo/dai/nl/326052577; Grigoras, A.; Grigoras, C.; Grigoriev, V.

    2014-01-01

    Measurements of multiparticle azimuthal correlations (cumulants) for charged particles in p-Pb at sNN=5.02 TeV and Pb-Pb at sNN=2.76 TeV collisions are presented. They help address the question of whether there is evidence for global, flowlike, azimuthal correlations in the p-Pb system. Comparisons

  6. Development of a used fuel cladding damage model incorporating circumferential and radial hydride responses

    Science.gov (United States)

    Chen, Qiushi; Ostien, Jakob T.; Hansen, Glen

    2014-04-01

    At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of δ-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radially-oriented hydride inclusions may weaken the cladding material and lead to issues during used fuel storage and transportation processes. A high fidelity model of the mechanical behavior of hydrides has utility in both designing fuel cladding to be more resistant to this hydride-induced weakening and also in suggesting modifications to drying, storage, and transport operations to reduce the impact of hydride formation and/or the avoidance of loading scenarios that could overly stress the radial inclusions. We develop a mechanical model for the Zry4-hydride system that, given a particular morphology of hydride inclusions, allows the calculation of the response of the hydrided cladding under various loading scenarios. The model treats the Zry4 matrix material as J2 elastoplastic, and treats the hydrides as platelets oriented in predefined directions (e.g., circumferentially and radially). The model is hosted by the Albany analysis framework, where a finite element approximation of the weak form of the cladding boundary value problem is solved using a preconditioned Newton-Krylov approach. Instead of forming the required system Jacobian operator directly or approximating its action with a differencing operation, Albany leverages the Trilinos Sacado package to form the Jacobian via automatic differentiation. We present results that describe the performance of the model in comparison with as-fabricated Zry4 as well as HB Robinson fuel cladding. Further, we also present performance results that demonstrate the efficacy of the overall solution method employed to host the model.

  7. Development of a used fuel cladding damage model incorporating circumferential and radial hydride responses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiushi, E-mail: qiushi@clemson.edu [Glenn Department of Civil Engineering, Clemson University, Clemson, SC 29634 (United States); Ostien, Jakob T., E-mail: jtostie@sandia.gov [Mechanics of Materials Dept. 8256, Sandia National Laboratories, P.O. Box 969, Livermore, CA 94551-0969 (United States); Hansen, Glen, E-mail: gahanse@sandia.gov [Computational Multiphysics Dept. 1443, Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185-1321 (United States)

    2014-04-01

    At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of δ-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radially-oriented hydride inclusions may weaken the cladding material and lead to issues during used fuel storage and transportation processes. A high fidelity model of the mechanical behavior of hydrides has utility in both designing fuel cladding to be more resistant to this hydride-induced weakening and also in suggesting modifications to drying, storage, and transport operations to reduce the impact of hydride formation and/or the avoidance of loading scenarios that could overly stress the radial inclusions. We develop a mechanical model for the Zry4-hydride system that, given a particular morphology of hydride inclusions, allows the calculation of the response of the hydrided cladding under various loading scenarios. The model treats the Zry4 matrix material as J{sub 2} elastoplastic, and treats the hydrides as platelets oriented in predefined directions (e.g., circumferentially and radially). The model is hosted by the Albany analysis framework, where a finite element approximation of the weak form of the cladding boundary value problem is solved using a preconditioned Newton–Krylov approach. Instead of forming the required system Jacobian operator directly or approximating its action with a differencing operation, Albany leverages the Trilinos Sacado package to form the Jacobian via automatic differentiation. We present results that describe the performance of the model in comparison with as-fabricated Zry4 as well as HB Robinson fuel cladding. Further, we also present performance results that demonstrate the efficacy of the overall solution method employed to host the model.

  8. Solid hydrides as hydrogen storage reservoirs; Hidruros solidos como acumuladores de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.; Sanchez, C.; Friedrichs, O.; Ares, J. R.; Leardini, F.; Bodega, J.; Fernandez, J. F.

    2010-07-01

    Metal hydrides as hydrogen storage materials are briefly reviewed in this paper. Fundamental properties of metal-hydrogen (gas) system such as Pressure-Composition-Temperature (P-C-T) characteristics are discussed on the light of the metal-hydride thermodynamics. Attention is specially paid to light metal hydrides which might have application in the car and transport sector. The pros and cons of MgH{sub 2} as a light material are outlined. Researches in course oriented to improve the behaviour of MgH{sub 2} are presented. Finally, other very promising alternative materials such as Al compounds (alanates) or borohydrides as light hydrogen accumulators are also considered. (Author)

  9. The storage of hydrogen in the form of metal hydrides: An application to thermal engines

    Science.gov (United States)

    Gales, C.; Perroud, P.

    1981-01-01

    The possibility of using LaNi56, FeTiH2, or MgH2 as metal hydride storage sytems for hydrogen fueled automobile engines is discussed. Magnesium copper and magnesium nickel hydrides studies indicate that they provide more stable storage systems than pure magnesium hydrides. Several test engines employing hydrogen fuel have been developed: a single cylinder motor originally designed for use with air gasoline mixture; a four-cylinder engine modified to run on an air hydrogen mixture; and a gas turbine.

  10. Hückel's Rule of Aromaticity Categorizes Aromatic Closo Boron Hydride Clusters

    OpenAIRE

    Poater i Teixidor, Jordi; Solà i Puig, Miquel; Viñas, Clara; Teixidor, Francesc

    2016-01-01

    A direct connection is established between tridimensional aromatic closo boron hydride clusters and planar aromatic [n]annulenes for medium and large size boron clusters. In particular, our results prove the existence of a link between the two-dimensional Hückel rule followed by aromatic [n]-annulenes and Wade-Mingos' rule of three-dimensional aromaticity applied to the aromatic [BnHn]2- closo boron hydride clusters. Our results show that closo boron hydride clusters can be categorized into d...

  11. Electrolyser-metal hydride-fuel cell system for seasonal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Vanhanen, J.P.; Lund, P.D.; Tolonen, J.S. [Helsinki Univ. of Technology, Engineering Physics and Mathematics Dept., Helsinki (Finland)

    1998-12-01

    A small-scale seasonal energy storage system, comprising an electrolyser, metal hydride hydrogen store and fuel cell, has been studied. According to the feasibility study, solid polymer electrolysers and fuel cells are the best options for the electrolyser-metal hydride-fuel cell energy storage systems. A round-trip efficiency of 30% has already been demonstrated, and the next target is to reach a round-trip efficiency close to 40%. The electyrolyser-metal hydride-fuel cell systems are suitable for small-scale self-sufficient applications in which high volumetric capacity is needed and safety aspects are appreciated. (Author)

  12. Generalized computational model for high-pressure metal hydrides with variable thermal properties

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2015-01-01

    This study considers a detailed 1D fueling model applied to a metal hydride system, with Ti1.1CrMn as the absorbing alloy, to predict the weight fraction of the absorbed hydrogen and the solid bed temperature. Dependencies of thermal conductivity and specific heat capacity upon pressure...... and hydrogen content, respectively, are accounted for by interpolating experimental data. The effect of variable parameters on the critical metal hydride thickness is investigated and compared to results obtained from a constant-parameter analysis. Finally, the discrepancy in the metal hydride thickness value...

  13. Thermal decomposition kinetics of titanium hydride and Al alloy melt foaming process

    Institute of Scientific and Technical Information of China (English)

    YANG; Donghui; HE; Deping; YANG; Shangrun

    2004-01-01

    A temperature programmed decomposition (TPD) apparatus with metal tube structure, in which Ar is used as the carrier gas, is established and the TPD spectrum of titanium hydride is acquired. Using consulting table method (CTM), spectrum superposition method (SSM) and differential spectrum technique, TPD spectrum of titanium hydride is separated and a set of thermal decomposition kinetics equations are acquired. According to these equations, the relationship between decomposition quantity and time for titanium hydride at the temperature of 940 K is obtained and the result well coincides with the Al alloy melt foaming process.

  14. Interaction of electrons with light metal hydrides in the transmission electron microscope.

    Science.gov (United States)

    Wang, Yongming; Wakasugi, Takenobu; Isobe, Shigehito; Hashimoto, Naoyuki; Ohnuki, Somei

    2014-12-01

    Transmission electron microscope (TEM) observation of light metal hydrides is complicated by the instability of these materials under electron irradiation. In this study, the electron kinetic energy dependences of the interactions of incident electrons with lithium, sodium and magnesium hydrides, as well as the constituting element effect on the interactions, were theoretically discussed, and electron irradiation damage to these hydrides was examined using in situ TEM. The results indicate that high incident electron kinetic energy helps alleviate the irradiation damage resulting from inelastic or elastic scattering of the incident electrons in the TEM. Therefore, observations and characterizations of these materials would benefit from increased, instead decreased, TEM operating voltage.

  15. Alkali Metal Cation Affinities of Anionic Main Group-Element Hydrides Across the Periodic Table.

    Science.gov (United States)

    Boughlala, Zakaria; Fonseca Guerra, Célia; Bickelhaupt, F Matthias

    2017-08-05

    We have carried out an extensive exploration of gas-phase alkali metal cation affinities (AMCA) of archetypal anionic bases across the periodic system using relativistic density functional theory at ZORA-BP86/QZ4P//ZORA-BP86/TZ2P. AMCA values of all bases were computed for the lithium, sodium, potassium, rubidium and cesium cations and compared with the corresponding proton affinities (PA). One purpose of this work is to provide an intrinsically consistent set of values of the 298 K AMCAs of all anionic (XHn-1(-) ) constituted by main group-element hydrides of groups 14-17 along the periods 2-6. In particular, we wish to establish the trend in affinity for a cation as the latter varies from proton to, and along, the alkali cations. Our main purpose is to understand these trends in terms of the underlying bonding mechanism using Kohn-Sham molecular orbital theory together with a quantitative bond energy decomposition analyses (EDA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Specimen type and size effects on lithium hydride tensile strength distributions

    Energy Technology Data Exchange (ETDEWEB)

    Oakes, Jr, R E

    1991-12-01

    Weibull's two-parameter statistical-distribution function is used to account for the effects of specimen size and loading differences on strength distributions of lithium hydride. Three distinctly differing uniaxial specimen types (i.e., an elliptical-transition pure tensile specimen, an internally pressurized ring tensile, and two sizes of four-point-flexure specimens) are shown to provide different strength distributions as expected, because of their differing sizes and modes of loading. After separation of strengths into volumetric- and surface-initiated failure distributions, the Weibull characteristic strength parameters for the higher-strength tests associated with internal fracture initiations are shown to vary as predicted by the effective specimen volume Weibull relationship. Lower-strength results correlate with the effective area to much lesser degree, probably because of the limited number of surface-related failures and the different machining methods used to prepare the specimen. The strength distribution from the fourth specimen type, the predominantly equibiaxially stressed disk-flexure specimen, is well below that predicted by the two-parameter Weibull-derived effective volume or surface area relations. The two-parameter Weibull model cannot account for the increased failure probability associated with multiaxial stress fields. Derivations of effective volume and area relationships for those specimens for which none were found in the literature, the elliptical-transition tensile, the ring tensile, and the disk flexure (including the outer region), are also included.

  17. Studies on MgNi-Based Metal Hydride Electrode with Aqueous Electrolytes Composed of Various Hydroxides

    Directory of Open Access Journals (Sweden)

    Jean Nei

    2016-08-01

    Full Text Available Compositions of MgNi-based amorphous-monocrystalline thin films produced by radio frequency (RF sputtering with a varying composition target have been optimized. The composition Mg52Ni39Co3Mn6 is identified to possess the highest initial discharge capacity of 640 mAh·g−1 with a 50 mA·g−1 discharge current density. Reproduction in bulk form of Mg52Ni39Co3Mn6 alloy composition was prepared through a combination of melt spinning (MS and mechanical alloying (MA, shows a sponge-like microstructure with >95% amorphous content, and is chosen as the metal hydride (MH alloy for a sequence of electrolyte experiments with various hydroxides including LiOH, NaOH, KOH, RbOH, CsOH, and (C2H54N(OH. The electrolyte conductivity is found to be closely related to cation size in the hydroxide compound used as 1 M additive to the 4 M KOH aqueous solution. The degradation performance of Mg52Ni39Co3Mn6 alloy through cycling demonstrates a strong correlation with the redox potential of the cation in the alkali hydroxide compound used as 1 M additive to the 5 M KOH aqueous solution. NaOH, CsOH, and (C2H54N(OH additions are found to achieve a good balance between corrosion and conductivity performances.

  18. Understanding of hydriding mechanisms of zircaloy-4 alloy during corrosion in PWR simulated conditions and influence of zirconium hydrides on zircaloy-4 corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Bisor-Melloul, C.; Tupin, M.; Bossis, P. [DEN/DANS/DMN/SEMI, CEA/Saclay, 91191 Gif-sur-Yvette (France); Chene, J. [DEN/DANS/DPC/SCCME, CEA/Saclay, 91191 Gif-sur-Yvette (France); Bechade, J.L. [DEN/DANS/DMN/SRMA, CEA/Saclay, 91191 Gif-sur-Yvette (France); Motta, A. [Mechanical and Nuclear Engineering Department, Penn State University, 227 Reber Building, University Park, PA 16802 (United States)

    2010-07-01

    Zirconium alloys are widely used as fuel claddings in Power Water Reactors. As they represent the first containment barrier to fission products, their mechanical integrity is essential for nuclear safety. During their corrosion in primary water, some of the hydrogen involved in the oxidation reaction with water ingresses into the alloy through the oxide layer. In the metallic matrix, once the solid solution limit is reached at the irradiation temperature, hydrogen precipitates as Zr hydrides mainly located just under the metal/oxide interface due to the thermal gradient across the cladding. As these hydrides may contribute to a larger oxide thickness and to a more fragile behaviour of the cladding, the minimization of hydrogen pick-up is required. Accordingly, since the Zircaloy-4 (Zr-1.3Sn-0.2Fe-0.1Cr) alloy is known to be sensitive to this phenomenon, the understanding of its hydriding mechanism and of the influence of zirconium hydrides on its corrosion behaviour is needed. Regarding the study of the hydriding mechanism, isotopic exchanges were carried out in D{sub 2}O environment at 360 deg. C and led to the localization, in the oxide scales, of the limiting step for the hydrogen diffusion. To estimate an apparent diffusion coefficient of hydrogen in the oxide formed on Zircaloy-4, we firstly based on SIMS profiles and penetration depth of deuterium in the dense part of the oxide film. Secondly, ERDA estimation of the hydrogen content in zirconia and fusion measurements of the hydrogen content in both metal and oxide were used to estimate a hydrogen flux absorbed by the alloy and hence to deduce an apparent diffusion coefficient. Finally, these two methods lead to quite similar values (between 2.10{sup -14} cm{sup 2}/s and 6.10{sup -14} cm{sup 2}/s) which are in accordance with bibliography. Concerning the impact of hydrides on the corrosion of Zircaloy-4, several pre-hydrided and reference samples were corroded simultaneously in primary water at 360 deg. C

  19. Hydrogen Storage Engineering Center of Excellence Metal Hydride Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-05-31

    The Hydrogen Storage Engineering Center of Excellence (HSECoE) was established in 2009 by the U.S. Department of Energy (DOE) to advance the development of materials-based hydrogen storage systems for hydrogen-fueled light-duty vehicles. The overall objective of the HSECoE is to develop complete, integrated system concepts that utilize reversible metal hydrides, adsorbents, and chemical hydrogen storage materials through the use of advanced engineering concepts and designs that can simultaneously meet or exceed all the DOE targets. This report describes the activities and accomplishments during Phase 1 of the reversible metal hydride portion of the HSECoE, which lasted 30 months from February 2009 to August 2011. A complete list of all the HSECoE partners can be found later in this report but for the reversible metal hydride portion of the HSECoE work the major contributing organizations to this effort were the United Technology Research Center (UTRC), General Motors (GM), Pacific Northwest National Laboratory (PNNL), the National Renewable Energy Laboratory (NREL) and the Savannah River National Laboratory (SRNL). Specific individuals from these and other institutions that supported this effort and the writing of this report are included in the list of contributors and in the acknowledgement sections of this report. The efforts of the HSECoE are organized into three phases each approximately 2 years in duration. In Phase I, comprehensive system engineering analyses and assessments were made of the three classes of storage media that included development of system level transport and thermal models of alternative conceptual storage configurations to permit detailed comparisons against the DOE performance targets for light-duty vehicles. Phase 1 tasks also included identification and technical justifications for candidate storage media and configurations that should be capable of reaching or exceeding the DOE targets. Phase 2 involved bench-level testing and

  20. Hydride-induced embrittlement of Zircaloy-4 cladding under plane-strain tension

    Science.gov (United States)

    Daum, Robert S.

    The mechanical response of high-burnup Zircaloy-4 fuel cladding subjected to a postulated reactivity initiated accident (referred to as a rod ejection accident (REA) in a pressurized water reactor) can be affected by hydrogen embrittlement. This study addresses the hydrogen embrittlement of non-irradiated, stress-relieved Zircaloy-4 cladding under conditions (state of stress and temperature) relevant to those of a reactivity initiated accident. Specifically, the study has investigated the effects of a concentrated density of hydride particles (in the form of a rim at the outer surface of the cladding tube introduced by gas-charging) on the cladding ductility when tested under a near-plane-strain tension at 25, 300, and 375°C. The influence of the hydride-rim thickness and local hydrogen contents on cladding ductility is studied as a function of temperature and correlated with the hydride microstructure. Using synchrotron x-ray diffraction, this study has found that the delta-hydride phase (i.e., ZrHx, where x ≈ 1.66) is the predominant hydride phase to precipitate in stress-relieved Zircaloy-4 cladding for hydrogen contents up to 1250 wt ppm. At hydrogen contents above 2700 wt ppm, although delta-hydride is still the majority phase, both gamma- and epsilon-hydride phases are also observed. The volume fraction of hydrides was estimated as a function of hydrogen content, using the diffracted x-ray intensities. These estimated values agree well with calculated values assuming hydride precipitates are delta-hydride. Under near-plane-strain hoop tension, the ductility and fracture of the cladding is highly dependent on both the hydride-rim thickness and the testing temperature. At room temperature, due to a high density of hydride particles within the rim, a Mode I crack is injected shortly after yielding. This limits cladding ductility, such that it decreases with increasing thickness of the hydride rim. Cladding containing hydride rims with a thickness of ≥100