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Sample records for h2 hd d2

  1. Total scattering cross-sections for the systems nH2 + nH2, pH2 + pH2, nD2 + nD2, oD2 + oD2 and HD + HD for relative energies below ten milli-electron volts

    International Nuclear Information System (INIS)

    Johnson, D.L.

    1979-01-01

    Relative total scattering cross sections for nH 2 + nH 2 , pH 2 + pH 2 , nD 2 + nD 2 , oD 2 + oD 2 , and HD + HD were measured with inclined nozzle beams derived from nozzle sources and intersecting at 21 0 . Both nozzles could be varied in temperature from 4.2K to 300K to provide the velocity range for the cross sections. The use of a parahydrogen converter allowed the measurement of the pH 2 + pH 2 and oD 2 + oD 2 cross sections. Cross sections for the H 2 + H 2 were measured over a relative velocity range of 200 m/s to 1450 m/s. The nH 2 + nH 2 results show an undulation in the velocity range between 350 m/s and 400 m/s that corresponds to a l = 3 orbiting resonance. Analysis of the pH 2 + pH 2 cross section indicates a l = 4 orbiting resonance near 586 m/s. This resonance has a peak energy of 1.79 meV and a measured energy width of 1.05 meV, both which agree well with theoretical predictions. The D 2 + D 2 cross sections have been measured in the velocity range between 190 m/s and 1000 m/s. No orbiting resonances have been observed, but in the oD 2 + oD 2 cross section a deep minimum between the l = 4 and the l = 5 resonances at low velocities is clearly suggested. Initial measurements of the HD + HD cross section suggests the presence of the l = 4 orbiting resonance near a relative velocity of 300 m/s. The experimental results for each system were normalized to the total cross sections, which were convoluted to account for experimental velocity and angular dispersions. Three different potentials were considered, but a chi-square fit of the data indicates that the Schaefer and Meyer potential, which has been theoretically obtained from first principles, provides the best overall description of the hydrogen systems in the low collisional energy range

  2. Permeation of a H2 + HD + D2 gas mixture through a polymer membrane

    International Nuclear Information System (INIS)

    Mercea, P.; Cuna, S.; Kreibik, S.; Ursu, I.

    1990-01-01

    The selective permeation of a H 2 + HD + D 2 gas mixture through a polyethylene terephthalate membrane was studied at T 20 0 C. It was found that the permeation of the HD through the membrane leads to a smaller overall hydrogen-deuterium separation factor than that determined in the permeation experiments with pure H 2 and D 2 . On the other hand, a process of isotopic exchange between deuterium atoms from the penetrant gas stream and hydrogen atoms from the polymer membrane is assumed and discussed in order to explain temporal variations of the H 2 , HD and D 2 concentrations of the permanent gas stream. (author)

  3. Production of H,D(2s, 2p) by electron impact (0 - 2000 eV) on simple hydrogen containing molecules, ch. 2, A2

    International Nuclear Information System (INIS)

    Moehlman, G.R.; Heer, F.J. de

    1977-01-01

    Absolute emission cross sections of Ly-α (H,D(2p → 1s)) radiation have been determined for 0 - 2000 eV electrons incident on H 2 , HD, HCl, H 2 O, NH 3 and CH 4 . By means of the application of electric quenching, the excitation cross sections of H,D(2s) could be obtained from the increase of the resulting Ly-α radiation for these molecules. Only in the case of electrons on H 2 , D 2 and HD was excitation of H,D(2s) found

  4. Specific heat and magnetization of RMn2(H,D)2

    International Nuclear Information System (INIS)

    Tarnawski, Z.; Kolwicz-Chodak, L.; Figiel, H.; Kim-Ngan, N.-T.H.; Havela, L.; Miliyanchuk, K.; Sechovsky, V.; Santava, E.; Sebek, J.

    2007-01-01

    The effect of hydrogen absorption on magnetic and thermodynamic properties of hydrides compounds RMn 2 (H,D) 2 (R = Y, Nd, Tb, Ho, and Er) have been investigated by performing specific heat and magnetization measurements in the temperature range of 2-320 K and in magnetic fields up to 9 T. The phase transition to the antiferromagnetic order accompanying a crystal structure transformation have been revealed by complicated-structure anomalies in specific heat and weak anomalies in magnetization

  5. Secondary electron emission from solid HD and a solid H2-D2 mixture

    DEFF Research Database (Denmark)

    Sørensen, H.; Børgesen, P.; Hao-Ming, Chen

    1983-01-01

    Secondary electron emission from solid HD and a solid 0.6 H2 + 0.4 D2 mixture has been studied for electron and hydrogen ion bombardment at primary energies from 0.5 to 3 keV and 2 to 10 keV/amu, respectively. The yield for solid HD is well explained by a simple stoichiometric model of the low...

  6. Effect of high pN2 and high pD2 on NH3 production, H2 evolution, and HD formation by nitrogenases

    International Nuclear Information System (INIS)

    Jensen, B.B.; Burris, R.H.

    1985-01-01

    We have investigated the effect of the partial pressure of N2 and D2 on HD formation, H2 evolution, and NH3 production by nitrogenase from Klebsiella pneumoniae and Clostridium pasteurianum. By using pressures up to 4 atm, we have been able to extend the concentration range of N2 and D2 in our investigations beyond that used in previous studies. The pN2 dependence of HD formation with constant pD2 ideally shows no HD formation under zero pN2, reaches a peak which depends on the pD2, and then decreases to zero at very high pN2. K. pneumoniae and C. pasteurianum nitrogenases differ in their Ki(D2) for nitrogen fixation. C. pasteurianum nitrogenase had the lower activity for formation of HD. With K. pneumoniae nitrogenase, D2 enhanced H2 evolution from 31% of the electron flux partitioned to H2 in the absence of D2 to 51% of the electron flux partitioned to H2 at 400 kPa of D2. With C. pasteurianum nitrogenase, the equivalent values were 33% and 48% of the total electron flux. Our results support previou findings on the mechanism for nitrogenase-catalyzed reductions proposed by W. W. Cleland

  7. State-to-state dynamics of the H*(n) + HDD*(n′) + H2 reactive scattering

    International Nuclear Information System (INIS)

    Yu, Shengrui; Su, Shu; Dai, Dongxu; Yuan, Kaijun; Yang, Xueming

    2014-01-01

    The state-to-state dynamics of the H * (n) + HDD * (n ′ ) + H 2 reactive scattering at the collision energy of 0.5 eV have been carried out for the first time by using H-atom Rydberg tagging time-of-flight technique. Experimental results show that the angular distribution of the total H 2 products presents clearly forward-backward asymmetric, which considerably differs from that of the corresponding H + + HDD + + H 2 reaction predicted by previously theoretical calculations. Such disagreement between these two processes suggests that the Fermi independent-collider model is also not valid in describing the dynamics of isotopic variants of the H * + H 2 reaction. The rotational state distribution of the H 2 products demonstrates a saw-toothed distribution with odd-j ′ > even-j ′ . This interesting observation is strongly influenced by nuclear spin statistics

  8. Hydrogenation/Deoxygenation (H/D Reaction of Furfural-Acetone Condensation Product using Ni/Al2O3-ZrO2 Catalyst

    Directory of Open Access Journals (Sweden)

    Adam Mahfud

    2016-08-01

    Full Text Available The catalytic hydrogenation/deoxygenation (H/D reaction was carried out using Ni/Al2O3-ZrO2 catalyst. The 10% (wt/wt of Ni were impregnated on Al2O3-ZrO2 (10NiAZ by wet impregnation method followed by calcination and reduction. X-Ray diffraction analysis showed that Nideposited on the surface, with specific surface areas (SBET was 48.616 m2/g. Catalyst performance were evaluated for H/D reaction over furfural-acetone condensation products, mixture of 2-(4-furyl-3-buten-2-on and 1,5-bis-(furan-2-yl-pentan-3-one. The reaction was carried out in a batch, performed at 150°C for 8 hours. The H/D reaction gave alkane derivatives C8 and C10 by hydrogenation process followed by ring opening of furan in 15.2% yield. While, oxygenated product C10-C13 were also detected in 17.2% yield. The increasing of pore volume of 10NiAZ might enhance catalyst activity over H/D reaction. The alkene C=C bond was easy to hydrogenated under this condition by the lower bond energy gap.

  9. Cold quantum-controlled rotationally inelastic scattering of HD with H2 and D2 reveals collisional partner reorientation

    Science.gov (United States)

    Perreault, William E.; Mukherjee, Nandini; Zare, Richard N.

    2018-05-01

    Molecular interactions are best probed by scattering experiments. Interpretation of these studies has been limited by lack of control over the quantum states of the incoming collision partners. We report here the rotationally inelastic collisions of quantum-state prepared deuterium hydride (HD) with H2 and D2 using a method that provides an improved control over the input states. HD was coexpanded with its partner in a single supersonic beam, which reduced the collision temperature to 0-5 K, and thereby restricted the involved incoming partial waves to s and p. By preparing HD with its bond axis preferentially aligned parallel and perpendicular to the relative velocity of the colliding partners, we observed that the rotational relaxation of HD depends strongly on the initial bond-axis orientation. We developed a partial-wave analysis that conclusively demonstrates that the scattering mechanism involves the exchange of internal angular momentum between the colliding partners. The striking differences between H2/HD and D2/HD scattering suggest the presence of anisotropically sensitive resonances.

  10. Quantum-tunneling isotope-exchange reaction H2+D-→HD +H-

    Science.gov (United States)

    Yuen, Chi Hong; Ayouz, Mehdi; Endres, Eric S.; Lakhamanskaya, Olga; Wester, Roland; Kokoouline, Viatcheslav

    2018-02-01

    The tunneling reaction H2+D-→HD +H- was studied in a recent experimental work at low temperatures (10, 19, and 23 K) by Endres et al. [Phys. Rev. A 95, 022706 (2017), 10.1103/PhysRevA.95.022706]. An upper limit of the rate coefficient was found to be about 10-18cm3 /s. In the present study, reaction probabilities are determined using the ABC program developed by Skouteris et al. [Comput. Phys. Commun. 133, 128 (2000), 10.1016/S0010-4655(00)00167-3]. The probabilities for ortho-H2 and para-H2 in their ground rovibrational states are obtained numerically at collision energies above 50 meV with the total angular momentum J =0 -15 and extrapolated below 50 meV using a WKB approach. Thermally averaged rate coefficients for ortho- and para-H2 are obtained; the largest one, for ortho-H2, is about 3.1 ×10-20cm3 /s, which agrees with the experimental results.

  11. Variable temperature ion trap studies of CH4+ + H2, HD and D2: negative temperature dependence and significant isotope effect

    International Nuclear Information System (INIS)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D.

    2004-01-01

    Reactions of methane cations, CH 4 + , with H 2 , HD and D 2 have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH 5 + in collisions with H 2 is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH 4 + with HD, the CH 5 + product ion (68% at 15 K) prevails over CH 4 D + (32%). Reaction of CH 4 + with D 2 is found to be much slower than with H 2 or HD. The rate coefficient for converting CH 4 + into CH 3 D + by H-D exchange has been determined to be smaller than 10 -12 cm 3 /s, indicating that scrambling in the CH 6 + complex is very unlikely

  12. Multicomponent DFT study of geometrical H/D isotope effect on hydrogen-bonded organic conductor, κ-H3(Cat EDT-ST)2

    Science.gov (United States)

    Yamamoto, Kaichi; Kanematsu, Yusuke; Nagashima, Umpei; Ueda, Akira; Mori, Hatsumi; Tachikawa, Masanori

    2017-04-01

    We theoretically investigated a significant contraction of the hydrogen-bonding O⋯O distance upon H/D substitution in our recently developed purely organic crystals, κ-H3(Cat-EDT-ST)2 (H-ST) and its isotopologue κ-D3(Cat-EDT-ST)2 (D-ST), having π-electron systems coupled with hydrogen-bonding fluctuation. The origin of this geometrical H/D isotope effect was elucidated by using the multicomponent DFT method, which takes the H/D nuclear quantum effect into account. The optimized O⋯O distance in H-ST was found to be longer than that in D-ST due to the anharmonicity of the potential energy curve along the Osbnd H bond direction, which was in reasonable agreement with the experimental trend.

  13. H/D exchange in the reaction of D2 with Bis(triphenyl phosphite)(acetylacetonato)rhodium(I), Rh(P(OPh)3)2(acac)

    International Nuclear Information System (INIS)

    Whitmore, B.C.; Eisenberg, R.

    1984-01-01

    The reaction of Rh(P)OPh) 3 ) 2 (acac) (1) with D 2 benzene has been studied by 1 H NMR spectroscopy, and complex 1 has been found to undergo H/D exchange at the ortho positions of the coordinated phosphite ligands and at the central methine position of the acetylacetonate ligand. At 75 0 C, the exchange reaction proceeds with the extent of deuterium incorporation into P(OPh) 3 being the same as that into acac at all stages of the H/D exchange process. At 60 0 C, deuterium incorporation into P(OPh) 3 is initially more rapid than that into the acac ligand. The initial rate of deuterium incorporation into P(OPh) 3 by 1 in benzene-d 6 under D 2 at 60 0 C proceeds with a first-order rate constant of 9.6 x 10 -5 s -1 . A mechanism for this exchange process is proposed. 13 references, 3 figures, 2 tables

  14. Polarizability tensor invariants of H2, HD, and D2

    Science.gov (United States)

    Raj, Ankit; Hamaguchi, Hiro-o.; Witek, Henryk A.

    2018-03-01

    We report an exhaustive compilation of wavelength-dependent matrix elements over the mean polarizability (α ¯ ) and polarizability anisotropy (γ) operators for the rovibrational states of the H2, HD, and D2 molecules together with an accompanying computer program for their evaluation. The matrix elements can be readily evaluated using the provided codes for rovibrational states with J = 0-15 and v = 0-4 and for any laser wavelengths in the interval 182.25-1320.6 nm corresponding to popular, commercially available lasers. The presented results substantially extend the scope of the data available in the literature, both in respect of the rovibrational transitions analyzed and the range of covered laser frequencies. The presented detailed tabulation of accurate polarizability tensor invariants is essential for successful realization of our main long-term goal: developing a universal standard for determining absolute Raman cross sections and absolute Raman intensities in experimental Rayleigh and Raman scattering studies of molecules.

  15. Effect of buffer general acid-base catalysis on the stereoselectivity of ester and thioester H/D exchange in D2O.

    Science.gov (United States)

    Mohrig, Jerry R; Reiter, Nicholas J; Kirk, Randy; Zawadski, Michelle R; Lamarre-Vincent, Nathan

    2011-04-06

    As part of a comprehensive investigation on the stereochemistry of base-catalyzed 1,2-elimination and H/D exchange reactions of carbonyl compounds, we have found that the stereoselectivity of H/D exchange of 3-hydroxybutyryl N-acetylcysteamine (3) in D(2)O is strongly influenced by the presence of buffers. This buffer effect is also operative with a simple acyclic ester, ethyl 3-methoxybutanoate (7). Buffers whose general-acid components are cyclic tertiary ammonium ions are particularly effective in changing the stereoselectivity. (2)H NMR analysis showed that without buffer, H/D exchange of 3 produces 81-82% of the 2R*, 3R* diastereomer of 2-deuterio 3 (the anti product). In the presence of 0.33 M 3-quinuclidinone buffer, only 44% of the 2R*, 3R* diastereomer was formed. With ester 7, the stereoselectivity went from 93-94% in DO(-)/D(2)O to 60% in the presence of buffer. Phosphate buffer, as well as others, also showed substantial effects. The results are put into the context of what is known about the mechanism of H/D exchange of esters and thioesters, and the relevance of the buffer effect on the mechanism of the enoyl-CoA hydratase reaction is discussed. It is likely that hydrogen bonding in the enolate-buffer acid encounter complex is an important stereochemical determinant in producing a greater amount of the 2R*, 3S* diastereomer (the syn product). Studies that involve the protonation of enolate anions in D(2)O need to include the buffer general acid in any understanding of the stereoselectivity. © 2011 American Chemical Society

  16. Physisorption and desorption of H2, HD and D2 on amorphous solid water ice. Effect on mixing isotopologue on statistical population of adsorption sites.

    Science.gov (United States)

    Amiaud, Lionel; Fillion, Jean-Hugues; Dulieu, François; Momeni, Anouchah; Lemaire, Jean-Louis

    2015-11-28

    We study the adsorption and desorption of three isotopologues of molecular hydrogen mixed on 10 ML of porous amorphous water ice (ASW) deposited at 10 K. Thermally programmed desorption (TPD) of H2, D2 and HD adsorbed at 10 K have been performed with different mixings. Various coverages of H2, HD and D2 have been explored and a model taking into account all species adsorbed on the surface is presented in detail. The model we propose allows to extract the parameters required to fully reproduce the desorption of H2, HD and D2 for various coverages and mixtures in the sub-monolayer regime. The model is based on a statistical description of the process in a grand-canonical ensemble where adsorbed molecules are described following a Fermi-Dirac distribution.

  17. H/D isotope effects in high temperature proton conductors

    DEFF Research Database (Denmark)

    Bonanos, Nikolaos; Huijser, A.; Poulsen, Finn Willy

    2015-01-01

    The atomic mass ratio of ca. 2 between deuterium and hydrogen is the highest for any pair of stable isotopes and results in significant and measurable H/D isotope effects in high temperature proton conductors containing these species. This paper discusses H/D isotope effects manifested in O-H/O-D...

  18. Frequency dependent polarizabilities for the ground state of H2, HD, and D2

    International Nuclear Information System (INIS)

    Rychlewski, J.

    1983-01-01

    A variation-perturbation method has been employed to calculate the dynamic dipole polarizability for the ground state of the hydrogen molecule. The explicit correlated electronic wave functions were used. The averaged values of α(#betta#) and #betta#(#betta#) for several vibration-rotation states of HD and D 2 are presented. Similar values for H 2 have also been calculated and were used to test the efficiency of the method and the validity of the assumption applied in the present calculation. The agreement of the present theoretical results with the existing experimental data is found to be satisfactory

  19. 1H(d,2p)n reaction at 2 GeV deuteron energy

    International Nuclear Information System (INIS)

    Erohuml, J.; Fodor, Z.; Koncz, P.; Seres, Z.; Perdrisat, C.F.; Punjabi, V.; Boudard, A.; Bonin, B.; Garcon, M.; Lombard, R.; Mayer, B.; Terrien, Y.; Tomasi, E.; Boivin, M.; Yonnet, J.; Bhang, H.C.; Youn, M.; Belostotsky, S.L.; Grebenuk, O.G.; Nikulin, V.N.; Kudin, L.G.

    1994-01-01

    The 1 H(d,2p)n deuteron breakup reaction was measured at 2 GeV deuteron energy in a kinematically complete experiment. Fivefold differential cross sections are given in a wide range of kinematical variables and analyzed in terms of impulse approximation and NN rescattering. The deuteron momentum density was determined and deviations were found depending on the value of the four-momentum transfer |t| in the scattering process. At low |t| the momentum densities are in good agreement with the impulse approximation whereas large discrepancies were found above q∼200 MeV/c when the four-momentum transfer was large. Various possible origins of the anomalous behavior at high q values are discussed

  20. Reactive collisions of electrons with H2+ , HD+, BeH+, BeD+ and SH+

    Science.gov (United States)

    Pop, Nicolina; Iacob, Felix; Mezei, János Zsolt; Motapon, Ousmanou; Niyonzima, Sebastien; Kashinski, David O.; Talbi, Dahbia; Hickman, Albert Peet; Schneider, Ioan F.

    2017-12-01

    In numerous cold ionized gases the dissociative recombination (DR), the elastic collisions (EC), the vibrational excitation (VE) (inelastic collisions) and the vibrational de-excitation (VdE) (super-elastic collisions) of molecular cations with electrons are major elementary processes. Using a stepwise method based on the Multichannel Quantum Defect Theory (MQDT), cross sections and rate coefficients have been obtained for reactions induced on HD+, H2+, BeH+, BeD+ and SH+. Moreover, the relative importance of the different reaction mechanisms, direct vs. indirect and rotational vs. non-rotational, have been studied for these molecular systems.

  1. Isotope effects in the reactions of atomic ions with H2, D2, and HD

    International Nuclear Information System (INIS)

    Armentrout, P.B.

    1992-01-01

    Reactions of various atomic ions with H 2 , D 2 , and HD have been studied as a function of kinetic energy by using guided ion beam mass spectrometry. For exothermic reactions, the dependence on translational and rotational energy and the effect of angular momentum conservation are illustrated. For endothermic reactions, the observed behavior falls into several distinct groups (statistical, direct and impulsive) that can be used to characterize the potential energy surfaces for the reactions. The characteristic behavior of each of these groups is illustrated and then used to understand more complex reaction systems

  2. Variable temperature ion trap studies of CH{sub 4}{sup +} + H{sub 2}, HD and D{sub 2}: negative temperature dependence and significant isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D

    2004-03-08

    Reactions of methane cations, CH{sub 4}{sup +}, with H{sub 2}, HD and D{sub 2} have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH{sub 5}{sup +} in collisions with H{sub 2} is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH{sub 4}{sup +} with HD, the CH{sub 5}{sup +} product ion (68% at 15 K) prevails over CH{sub 4}D{sup +} (32%). Reaction of CH{sub 4}{sup +} with D{sub 2} is found to be much slower than with H{sub 2} or HD. The rate coefficient for converting CH{sub 4}{sup +} into CH{sub 3}D{sup +} by H-D exchange has been determined to be smaller than 10{sup -12} cm{sup 3}/s, indicating that scrambling in the CH{sub 6}{sup +} complex is very unlikely.

  3. State-to-state dynamics of the H{sup *}(n) + HDD{sup *}(n{sup ′}) + H{sub 2} reactive scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shengrui; Su, Shu; Dai, Dongxu; Yuan, Kaijun, E-mail: kjyuan@dicp.ac.cn, E-mail: xmyang@dicp.ac.cn; Yang, Xueming, E-mail: kjyuan@dicp.ac.cn, E-mail: xmyang@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China)

    2014-01-21

    The state-to-state dynamics of the H{sup *}(n) + HDD{sup *}(n{sup ′}) + H{sub 2} reactive scattering at the collision energy of 0.5 eV have been carried out for the first time by using H-atom Rydberg tagging time-of-flight technique. Experimental results show that the angular distribution of the total H{sub 2} products presents clearly forward-backward asymmetric, which considerably differs from that of the corresponding H{sup +} + HDD{sup +} + H{sub 2} reaction predicted by previously theoretical calculations. Such disagreement between these two processes suggests that the Fermi independent-collider model is also not valid in describing the dynamics of isotopic variants of the H{sup *} + H{sub 2} reaction. The rotational state distribution of the H{sub 2} products demonstrates a saw-toothed distribution with odd-j{sup ′} > even-j{sup ′}. This interesting observation is strongly influenced by nuclear spin statistics.

  4. High accuracy results for the energy levels of the molecular ions H+2, D+2 and HD+, up to J = 2

    International Nuclear Information System (INIS)

    Karr, J Ph; Hilico, L

    2006-01-01

    We present a nonrelativistic calculation of the rotation-vibration levels of the molecular ions H + 2 , D + 2 and HD + , relying on the diagonalization of the exact three-body Hamiltonian in a variational basis. The J = 2 levels are obtained with a very high accuracy of 10 -14 au (for most levels) representing an improvement by five orders of magnitude over previous calculations. The accuracy is also improved for the J = 1 levels of H + 2 and D + 2 with respect to earlier works. Moreover, we have computed the sensitivities of the energy levels with respect to the mass ratios, allowing these levels to be used for metrological purposes

  5. Comparison of experimental and theoretical integral cross sections for D+H2(v=1, j=1)→HD(v'=1, j')+H

    International Nuclear Information System (INIS)

    Kliner, D.A.V.; Adelman, D.E.; Zare, R.N.

    1991-01-01

    We have measured the nascent HD(v'=1, j') product rotational distribution from the reaction D+H 2 (v, j) in which the H 2 reagent was either thermal (v=0, j) or prepared in the level (v=1, j=1) by stimulated Raman pumping. Translationally hot D atoms were obtained by uv laser photolysis of DBr or DI. Photolysis of DBr generated D atoms with center-of-mass collision energies (E rel ) of 1.04 and 0.82 eV, which corresponded to the production of ground state Br and spin--orbit-excited Br*, respectively. The E rel values for DI photolysis were 1.38 and 0.92 eV. Quantum-state-specific detection of HD was accomplished via (2+1) resonance-enhanced multiphoton ionization and time-of-flight mass spectrometry. Vibrational excitation of the H 2 reagent results in substantial rotational excitation of the HD(v'=1) product and increases the reaction rate into v'=1 by about a factor of 4. Although the quantum-mechanical calculation of Blais et al. [Chem. Phys. Lett. 166, 11 (1990)] for the D+H 2 (v=1, j=1)→HD(v'=1, j')+H product rotational distribution at E rel =1.02 eV is in qualitative agreement with experiment, it does not quantitatively agree with the measured distribution. Specifically, the calculated distribution is too hot by 2--3 rotational quanta, and the predicted enhancement in the v'=1 rate with reagent vibrational excitation is too large by 67%±9

  6. D/H fractionation in the H2-H2O system at supercritical water conditions: Compositional and hydrogen bonding effects

    Science.gov (United States)

    Foustoukos, Dionysis I.; Mysen, Bjorn O.

    2012-06-01

    A series of experiments has been conducted in the H2-D2-D2O-H2O-Ti-TiO2 system at temperatures ranging from 300 to 800 °C and pressures between ∼0.3 and 1.3 GPa in a hydrothermal diamond anvil cell, utilizing Raman spectroscopy as a quantitative tool to explore the relative distribution of hydrogen and deuterium isotopologues of the H2 and H2O in supercritical fluids. In detail, H2O-D2O solutions (1:1) were reacted with Ti metal (3-9 h) in the diamond cell, leading to formation of H2, D2, HD, and HDO species through Ti oxidation and H-D isotope exchange reactions. Experimental results obtained in situ and at ambient conditions on quenched samples indicate significant differences from the theoretical estimates of the equilibrium thermodynamic properties of the H-D exchange reactions. In fact, the estimated enthalpy for the H2(aq)-D2(aq) disproportionation reaction (ΔHrxn) is about -3.4 kcal/mol, which differs greatly from the +0.16 kcal/mol predicted for the exchange reaction in the gas phase by statistical mechanics models. The exothermic behavior of the exchange reaction implies enhanced stability of H2 and D2 relative to HD. Accordingly, the significant energy difference of the internal H2(aq)-D2(aq)-HD(aq) equilibrium translates to strong differences of the fractionation effects between the H2O-H2 and D2O-D2 isotope exchange relationships. The D/H fractionation factors between H2O-H2(aq) and D2O-D2(aq) differ by 365‰ in the 600-800 °C temperature range, and are indicative of the greater effect of D2O contribution to the δD isotopic composition of supercritical fluids. The negative ΔHrxn values for the H2(aq)-D2(aq)-HD(aq) equilibrium and the apparent decrease of the equilibrium constant with increasing temperature might be because of differences of the Henry’s law constant between the H- and D-bearing species dissolved in supercritical aqueous solutions. Such effects may be attributed to the stronger hydrogen bonding in the O-H⋯O relative to the

  7. Isotopic exchange processes in cold plasmas of H2/D2 mixtures.

    Science.gov (United States)

    Jiménez-Redondo, Miguel; Carrasco, Esther; Herrero, Víctor J; Tanarro, Isabel

    2011-05-28

    Isotope exchange in low pressure cold plasmas of H(2)/D(2) mixtures has been investigated by means of mass spectrometric measurements of neutrals and ions, and kinetic model calculations. The measurements, which include also electron temperatures and densities, were performed in a stainless steel hollow cathode reactor for three discharge pressures: 1, 2 and 8 Pa, and for mixture compositions ranging from 100% H(2) to 100% D(2). The data are analyzed in the light of the model calculations, which are in good global agreement with the experiments. Isotope selective effects are found both in the surface recombination and in the gas-phase ionic chemistry. The dissociation of the fuel gas molecules is followed by wall recycling, which regenerates H(2) and D(2) and produces HD. Atomic recombination at the wall is found to proceed through an Eley-Rideal mechanism, with a preference for reaction of the adsorbed atoms with gas phase D atoms. The best fit probabilities for Eley-Rideal abstraction with H and D are: γ(ER H) = 1.5 × 10(-3), γ(ER D) = 2.0 × 10(-3). Concerning ions, at 1 Pa the diatomic species H(2)(+), D(2)(+) and HD(+), formed directly by electron impact, prevail in the distributions, and at 8 Pa, the triatomic ions H(3)(+), H(2)D(+), HD(2)(+) and D(3)(+), produced primarily in reactions of diatomic ions with molecules, dominate the plasma composition. In this higher pressure regime, the formation of the mixed ions H(2)D(+) and HD(2)(+) is favoured in comparison with that of H(3)(+) and D(3)(+), as expected on statistical grounds. The model results predict a very small preference, undetectable within the precision of the measurements, for the generation of triatomic ions with a higher degree of deuteration, which is probably a residual influence at room temperature of the marked zero point energy effects (ZPE), relevant for deuterium fractionation in interstellar space. In contrast, ZPE effects are found to be decisive for the observed distribution of

  8. Isotopic analysis of H2, HD, D2 mixtures and analysis of ortho-para-hydrogen mixtures by gas chromatography

    International Nuclear Information System (INIS)

    Botter, F.; Perriere, G. de la; Tistchenko, S.

    1961-01-01

    This communication describes the present situation concerning the possibilities of vapor phase chromatography for the separation and analysis of mixtures of H 2 , HD and D 2 and of ortho- and para-hydrogen mixtures. Separation factors for physical adsorption of the various varieties of hydrogen have been deduced from chromatograms and have also been measured directly with a static method - the agreements is good. (author) [fr

  9. Mechanism of Nitrogenase H 2 Formation by Metal-Hydride Protonation Probed by Mediated Electrocatalysis and H/D Isotope Effects

    Energy Technology Data Exchange (ETDEWEB)

    Khadka, Nimesh [Department of Chemistry; Milton, Ross D. [Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States; Shaw, Sudipta [Department of Chemistry; Lukoyanov, Dmitriy [Department; Dean, Dennis R. [Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States; Minteer, Shelley D. [Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States; Raugei, Simone [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Hoffman, Brian M. [Department; Seefeldt, Lance C. [Department of Chemistry

    2017-09-15

    Nitrogenase catalyzes the reduction of dinitrogen (N2) to ammonia (NH3) with obligatory reduction of protons (H+) to dihydrogen (H2) through a mechanism involving reductive elimination of two [Fe-H-Fe] bridging hydrides at its active site FeMo-cofactor. The overall rate-limiting step is associated with ATP-driven electron delivery from Fe protein, precluding isotope effect measurements on substrate reduction steps. Here, we use mediated bioelectrocatalysis to drive electron delivery to MoFe protein without Fe protein and ATP hydrolysis, thereby eliminating the normal rate-limiting step. The ratio of catalytic current in mixtures of H2O and D2O, the proton inventory, changes linearly with the D2O/H2O ratio, revealing that a single H/D is involved in the rate limiting step. Kinetic models, along with measurements that vary the electron/proton delivery rate and use different substrates, reveal that the rate-limiting step under these conditions is the H2 formation reaction. Altering the chemical environment around the active site FeMo-cofactor in the MoFe protein either by substituting nearby amino acids or transferring the isolated FeMo-cofactor into a different peptide matrix, changes the net isotope effect, but the proton inventory plot remains linear, consistent with an unchanging rate-limiting step. Density functional theory predicts a transition state for H2 formation where the proton from S-H+ moves to the hydride in Fe-H-, predicting the number and magnitude of the observed H/D isotope effect. This study not only reveals the mechanism of H2 formation, but also illustrates a strategy for mechanistic study that can be applied to other enzymes and to biomimetic complexes.

  10. Analysis of 2H(d vector, p)3H reaction at 30-90 keV by four-body Faddeev-Yakubovsky equation

    International Nuclear Information System (INIS)

    Uzu, Eizo; Oryu, Shinsho; Tanifuji, Makoto.

    1993-01-01

    Low-energy 2 H(d vector, p) 3 H reactions are investigated by the four-body Faddeev-Yakubovsky equations. Cross sections and tensor analyzing powers are calculated at 30-90 keV energies. The PEST-1 potentials are used for nucleon-nucleon interactions. The [2+2] and [3+1] subamplitudes are treated by the Hilbert-Schmidt expansions. Numerical results give qualitative explanation of experimental data. (author)

  11. Arene-mercury complexes stabilized by gallium chloride: relative rates of H/D and arene exchange.

    Science.gov (United States)

    Branch, Catherine S; Barron, Andrew R

    2002-11-27

    We have previously proposed that the Hg(arene)(2)(GaCl(4))(2) catalyzed H/D exchange reaction of C(6)D(6) with arenes occurs via an electrophilic aromatic substitution reaction in which the coordinated arene protonates the C(6)D(6). To investigate this mechanism, the kinetics of the Hg(C(6)H(5)Me)(2)(GaCl(4))(2) catalyzed H/D exchange reaction of C(6)D(6) with naphthalene has been studied. Separate second-order rate constants were determined for the 1- and 2-positions on naphthalene; that is, the initial rate of H/D exchange = k(1i)[Hg][C-H(1)] + k(2i)[Hg][C-H(2)]. The ratio of k(1i)/k(2i) ranges from 11 to 2.5 over the temperature range studied, commensurate with the proposed electrophilic aromatic substitution reaction. Observation of the reactions over an extended time period shows that the rates change with time, until they again reach a new and constant second-order kinetics regime. The overall form of the rate equation is unchanged: final rate = k(1f)[Hg][C-H(1)] + k(2f)[Hg][C-H(2)]. This change in the H/D exchange is accompanied by ligand exchange between Hg(C(6)D(6))(2)(GaCl(4))(2) and naphthalene to give Hg(C(10)H(8))(2)(GaCl(4))(2,) that has been characterized by (13)C CPMAS NMR and UV-visible spectroscopy. The activation parameters for the ligand exchange may be determined and are indicative of a dissociative reaction and are consistent with our previously calculated bond dissociation for Hg(C(6)H(6))(2)(AlCl(4))(2). The initial Hg(arene)(2)(GaCl(4))(2) catalyzed reaction of naphthalene with C(6)D(6) involves the deuteration of naphthalene by coordinated C(6)D(6); however, as ligand exchange progresses, the pathway for H/D exchange changes to where the protonation of C(6)D(6) by coordinated naphthalene dominates. The site selectivity for the H/D exchange is initially due to the electrophilic aromatic substitution of naphthalene. As ligand exchange occurs, this selectivity is controlled by the activation of the naphthalene C-H bonds by mercury.

  12. Production of Long-Lived H2-, HD-, and D2- during Grazing Scattering Collisions of H2+, H3+, D2+, D3+ and D2H+ Ions with KBr, KCl, and LiF Surfaces

    International Nuclear Information System (INIS)

    Seely, D. G.; Meyer, F. W.; Zhang, H.; Havener, C. C.

    2009-01-01

    We have investigated atomic and molecular anion production from singly charged atomic and molecular hydrogen, deuterium, and mixed isotope beams during grazing interactions with large area KBr, KCl, and LiF single crystal targets in the incident energy range 4-22.5 keV. Electron capture and, in the case of incident molecular ions, dissociation occur during the grazing interactions without appreciable angular straggling or change in velocity. As a result, atomic and molecular cation and anion interaction products are strongly peaked in the specular reflection direction, and, in case of dissociation products, at the fractional kinetic energies determined by the product fragment mass to incident mass ratios. A large-acceptance electrostatic analysis and detection system is used to collect the charged scattering products with high efficiency. Of particular interest is the production of metastable molecular ions H 2 - , HD - , and D 2 - . By comparing molecular anion yields obtained from incident hydrogen, deuterium and mixed isotope molecular ions, effects arising from isobaric contamination are seen for some incident molecular species.

  13. Electrochemical H-D isotope effect at metal-perovskite proton conductor interfaces

    DEFF Research Database (Denmark)

    Kek, D.; Bonanos, N.

    1999-01-01

    The H-D isotope effect on the electrode kinetics of a metal-proton conductor interface has been investigated. The current-voltage behaviour depends on the nature of the electrode (Ni, Ag), the atmosphere (H(2), D(2)), the partial pressures of the gases, and the temperature. The isotope effect was...

  14. Experimental and theoretical studies of the VUV emission and absorption spectra of H{sub 2}, HD and D{sub 2} molecules; Etude experimentale et theorique des spectres d'emission et d'absorption VUV des molecules H{sub 2}, D{sub 2} et HD

    Energy Technology Data Exchange (ETDEWEB)

    Roudjane, M

    2007-12-15

    The aim of this thesis is to carry out an experimental study of the absorption and emission spectra of the D{sub 2} and HD isotopes, with high resolution, in the VUV domain and to supplement it by a theoretical study of the excited electronic states involved in the observed transitions. The emission spectra of HD and D{sub 2} are produced by Penning discharge source operating under low pressure and are recorded in the spectral range 78 - 170 nm. The recorded spectra contains more than 20.000 lines. The analysis of the spectrum consists in identifying and assigning the lines to the electronic transitions between energy levels of the molecule. The present analysis is based on our theoretical calculations of the ro-vibrational energy levels of the excited electronic states and the transition probabilities from these states towards the energy levels of the fundamental state. The theoretical results are obtained by resolving the coupled equations between the excited electronic states B{sup 1}{sigma}{sub u}{sup 1}, B'{sup 1}{sigma}{sub u}{sup 1}, C{sup 1}{pi}{sub u}{sup 1} and D{sup 1}{pi}{sub u}{sup 1}, taking into account the nonadiabatic couplings between these states, and they are obtained in the adiabatic approximation for the excited electronic states B''B-bar{sup 1}{sigma}{sub u}{sup +}, D'{sup 1}{pi}{sub u}{sup 1} and D''{sup 1}{pi}{sub u}{sup 1}. The equations are resolved using a modern method based on the discretization variables representation method. In addition, we have carried out a study of the absorption spectra of the HD and D{sub 2} molecules.

  15. Selectivity in the inelastic rotational scattering of D2 and HD molecules from graphite: Similarities and differences respect to the H2 case

    Science.gov (United States)

    Rutigliano, Maria; Pirani, Fernando

    2018-03-01

    The inelastic scattering of D2 and HD molecules impinging on a graphite surface in well-defined initial roto-vibrational states has been studied by using the computational setup recently developed to characterize important selectivities in the molecular dynamics occurring at the gas-surface interface. In order to make an immediate comparison of determined elastic and inelastic scattering probabilities, we considered for D2 and HD molecules the same initial states, as well as the same collision energy range, previously selected for the investigation of H2 behaviour. The analysis of the back-scattered molecules shows that, while low-lying initial vibrational states are preserved, the medium-high initial ones give rise to final states covering the complete ladder of vibrational levels, although with different probability for the various cases investigated. Moreover, propensities in the formation of the final rotational states are found to depend strongly on the initial ones, on the collision energy, and on the isotopologue species.

  16. Theoretical/experimental comparison of deep tunneling decay of quasi-bound H(D)OCO to H(D) + CO2

    International Nuclear Information System (INIS)

    Wagner, Albert F.; Dawes, Richard; Continetti, Robert E.; Guo, Hua

    2014-01-01

    The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO 2 on several recent ab initio potential energy surfaces for the HOCO system. The tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. The resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment occurring for the PIP-NN surface based on UCCSD(T)-F12a/AVTZ electronic structure calculations and also a partial surface constructed for this study based on CASPT2/AVDZ electronic structure calculations. These two surfaces differ in barrier height by 1.6 kcal/mol but when matched at the saddle point have an almost identical shape along their reaction paths. The PIP surface is a less accurate fit to a smaller ab initio data set than that used for PIP-NN and its computed survival fractions are somewhat inferior to PIP-NN. The LTSH potential energy surface is the oldest surface examined and is qualitatively incompatible with experiment. This surface also has a small discontinuity that is easily repaired. On each surface, four different approximate tunneling methods are compared but only the small curvature tunneling method and the improved semiclassical transition state method produce useful results on all four surfaces. The results of these two methods are generally comparable and in qualitative agreement with experiment on the PIP-NN and CASPT2 surfaces. The original semiclassical transition state theory method produces qualitatively incorrect tunneling probabilities on all surfaces except the PIP. The Eckart tunneling method uses the least

  17. Quantum Dynamics Study of the Isotopic Effect on Capture Reactions: HD, D2 + CH3

    Science.gov (United States)

    Wang, Dunyou; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Time-dependent wave-packet-propagation calculations are reported for the isotopic reactions, HD + CH3 and D2 + CH3, in six degrees of freedom and for zero total angular momentum. Initial state selected reaction probabilities for different initial rotational-vibrational states are presented in this study. This study shows that excitations of the HD(D2) enhances the reactivities; whereas the excitations of the CH3 umbrella mode have the opposite effects. This is consistent with the reaction of H2 + CH3. The comparison of these three isotopic reactions also shows the isotopic effects in the initial-state-selected reaction probabilities. The cumulative reaction probabilities (CRP) are obtained by summing over initial-state-selected reaction probabilities. The energy-shift approximation to account for the contribution of degrees of freedom missing in the six dimensionality calculation is employed to obtain approximate full-dimensional CRPs. The rate constant comparison shows H2 + CH3 reaction has the biggest reactivity, then HD + CH3, and D2 + CH3 has the smallest.

  18. Production of H, D (2s, 2p) by electron impact (0-2000 eV) on simple hydrogen containing molecules

    International Nuclear Information System (INIS)

    Moehlmann, G.R.; Shima, K.H.; Heer, F.J. de

    1978-01-01

    Absolute emission cross sections of Ly-α (H, D (2p → 1s)) radiation have been determined for 0-2000 eV electrons incident on H 2 , HD, D 2 , HCl, H 2 O, NH 3 and CH 4 . By means of the application of electric quenching the excitation cross sections of H, D (2s) could be obtained from the increase of the resulting Ly-α radiation for these molecules. It was found that only for H 2 , HD and D 2 fragments in the H (2s) state are formed. (Auth.)

  19. Anomalous H/D isotope effect on 35Cl NQR frequencies and H/D isotope effect on 1H MAS NMR spectra in pyrrolidinium p-chlorobenzoate

    International Nuclear Information System (INIS)

    Nakano, Ryo; Honda, Hisashi; Nakata, Eiichi; Takamizawa, Satoshi; Noro, Sumiko; Kimura, Taiki; Kyo, Shin-shin; Ishimaru, Shin'ichi; Miyake, Ryosuke

    2010-01-01

    An anomalous isotope effect was observed in the 35 Cl NQR frequency of pyrrolidinium p-chlorobenzoate (C 4 H 8 NH 2 + ·ClC 6 H 4 COO - ) by deuterium substitution of hydrogen atoms which form two kinds of N-H...O type hydrogen bonds. Large negative frequency shifts of the 35 Cl resonance lines, reaching 309 kHz at 77 K and 267 kHz at 293 K, were obtained upon deuteration, although the Cl atom in the molecule formed no hydrogen bonds in the crystal. 1 H MAS NMR lines showed significant changes by the deuterium substitution, while in contrast, small shifts of 13 C CP/MAS NMR signals were obtained. Our measurements of 1 H NMR spin-lattice relaxation times (T 1 ) suggested that the H/D isotope shifts detected from the 35 Cl NQR frequencies and 1 H NMR spectra are due to structural changes rather than molecular dynamics. Single-crystal X-ray diffraction measurements showed two remarkable H/D isotope differences in the molecular arrangements, (1) the N-H length along the crystallographic a axis became 1 pm shorter, and (2) the dihedral angle between benzene and the pyrrolidine ring changed by 1.1(2)deg upon deuteration. Using density functional theory estimations, the anomalous 35 Cl NQR frequency shifts and 1 H MAS NMR line-shape changes could be explained by the dihedral angle change rather than the N-H length difference. (author)

  20. Experimental and theoretical studies of the VUV emission and absorption spectra of H2, HD and D2 molecules

    International Nuclear Information System (INIS)

    Roudjane, M.

    2007-12-01

    The aim of this thesis is to carry out an experimental study of the absorption and emission spectra of the D 2 and HD isotopes, with high resolution, in the VUV domain and to supplement it by a theoretical study of the excited electronic states involved in the observed transitions. The emission spectra of HD and D 2 are produced by Penning discharge source operating under low pressure and are recorded in the spectral range 78 - 170 nm. The recorded spectra contains more than 20.000 lines. The analysis of the spectrum consists in identifying and assigning the lines to the electronic transitions between energy levels of the molecule. The present analysis is based on our theoretical calculations of the ro-vibrational energy levels of the excited electronic states and the transition probabilities from these states towards the energy levels of the fundamental state. The theoretical results are obtained by resolving the coupled equations between the excited electronic states B 1 Σ u 1 , B' 1 Σ u 1 , C 1 Π u 1 and D 1 Π u 1 , taking into account the nonadiabatic couplings between these states, and they are obtained in the adiabatic approximation for the excited electronic states B''B-bar 1 Σ u + , D' 1 Π u 1 and D'' 1 Π u 1 . The equations are resolved using a modern method based on the discretization variables representation method. In addition, we have carried out a study of the absorption spectra of the HD and D 2 molecules

  1. Theoretical/experimental comparison of deep tunneling decay of quasi-bound H(D)OCO to H(D) + CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Albert F., E-mail: wagner@anl.gov [Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States); Dawes, Richard [Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States); Continetti, Robert E. [Department of Chemistry and Biochemistry, University of California, San Diego, California 92093 (United States); Guo, Hua [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2014-08-07

    The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO{sub 2} on several recent ab initio potential energy surfaces for the HOCO system. The tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. The resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment occurring for the PIP-NN surface based on UCCSD(T)-F12a/AVTZ electronic structure calculations and also a partial surface constructed for this study based on CASPT2/AVDZ electronic structure calculations. These two surfaces differ in barrier height by 1.6 kcal/mol but when matched at the saddle point have an almost identical shape along their reaction paths. The PIP surface is a less accurate fit to a smaller ab initio data set than that used for PIP-NN and its computed survival fractions are somewhat inferior to PIP-NN. The LTSH potential energy surface is the oldest surface examined and is qualitatively incompatible with experiment. This surface also has a small discontinuity that is easily repaired. On each surface, four different approximate tunneling methods are compared but only the small curvature tunneling method and the improved semiclassical transition state method produce useful results on all four surfaces. The results of these two methods are generally comparable and in qualitative agreement with experiment on the PIP-NN and CASPT2 surfaces. The original semiclassical transition state theory method produces qualitatively incorrect tunneling probabilities on all surfaces except the PIP. The Eckart tunneling method uses the

  2. A Comprehensive Study on the Electronic State of Hydrogen in α-Phase PdH(D)x-Does a Chemical Bond Between Pd and H(D) Exist?

    Science.gov (United States)

    Dekura, Shun; Kobayashi, Hirokazu; Ikeda, Ryuichi; Maesato, Mitsuhiko; Yoshino, Haruka; Ohba, Masaaki; Ishimoto, Takayoshi; Kawaguchi, Shogo; Kubota, Yoshiki; Yoshioka, Satoru; Matsumura, Syo; Sugiyama, Takeharu; Kitagawa, Hiroshi

    2018-06-12

    The palladium(Pd)-hydrogen(H) system is one of the most famous hydrogen storage systems. Although there has been much research on β-phase PdH(D)x, we comprehensively investigated the nature of the interaction between Pd and H(D) in α-phase PdH(D)x (x H(D) chemical bond for the first time, by various in situ experimental techniques and first-principles theoretical calculations. The lattice expansion by H(D) dissolution in the α-phase lattice suggests the existence of interaction between Pd and H(D). The decrease of magnetic susceptibility and the increase of electrical resistivity indicate that the electronic states are changed by the H(D) dissolution in the α phase. In situ solid-state 1H and 2H NMR results and first-principles theoretical calculations revealed that a Pd-H(D) chemical bond exists in the α phase, but the bonding character of the Pd-H(D) chemical bond in the α phase is quite different from that in the β phase; the nature of the Pd-H(D) chemical bond in the α phase is a localized covalent bond whereas that in the β phase is a metallic bond. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Isotopic analysis of H{sub 2}, HD, D{sub 2} mixtures and analysis of ortho-para-hydrogen mixtures by gas chromatography; Dosages par chromatographie en phase gazeuse de melanges d'hydrogene, d'hydrogene deutere, de deuterium et de melanges ortho-para-hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Botter, F; Perriere, G de la; Tistchenko, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    This communication describes the present situation concerning the possibilities of vapor phase chromatography for the separation and analysis of mixtures of H{sub 2}, HD and D{sub 2} and of ortho- and para-hydrogen mixtures. Separation factors for physical adsorption of the various varieties of hydrogen have been deduced from chromatograms and have also been measured directly with a static method - the agreements is good. (author) [French] Le present rapport decrit diverses possibilites qu'offre la chromatographie gazeuse d'elution en ce qui concerne le dosage des melanges H{sub 2}, HD, D{sub 2} et des varietes ortho et para de l'hydrogene. On a calcule, a partir des chromatogrammes obtenus, les facteurs de separation par adsorption physique des differentes varietes d'hydrogene, et compare aux facteurs de separation determines par mesure directe. (auteur)

  4. Small-angle neutron polarization for the 2H(d vector,n vector)3He reaction near Esub(d) = 8MeV

    International Nuclear Information System (INIS)

    Tornow, W.; Woye, W.; Mack, G.

    1981-01-01

    Considerable improvement in the quality of analyzing power experiments performed with polarized fast neutrons has been achieved during the last few years by using neutrons from the polarization transfer reaction 2 H(d vector,n vector) 3 He at a reaction angle of theta = 0 0 . To compromise in these experiments between intensity problems and finite geometry corrections, it is desirable in some instances to subtend a full-width angle Δtheta of 20 0 (lab) centered about theta = 0 0 . In order to investigate the suitability of this reaction as a source of polarized neutrons for cases where the scatterer is close to the neutron source, the neutron polarization of the reaction 2 H(d vector,n vector) 3 He has been studied with Δtheta of about 3 0 in 3 0 steps out to theta = 20 0 (lab). An incident deuteron energy near 8 MeV was chosen to yield outgoing neutrons at 11.0 MeV, a typical energy for neutron analyzing power experiments. It is found that the effective neutron polarization, a combination of the two polarizations measured when the direction of the deuteron polarization is inverted or flipped at the polarized ion source, is large and nearly constant for angles between theta = 0 0 and theta = 10 0 (lab). (orig.)

  5. State resolved rotational excitation in HD+D2 collisions. II. Angular dependence of 0→2 transitions

    International Nuclear Information System (INIS)

    Buck, U.; Huisken, F.; Maneke, G.; Schaefer, J.

    1983-01-01

    Time-of-flight spectra for the scattering of HD molecules from D 2 molecules have been measured at a collision energy of E = 70.3 meV over a range of center-of-mass scattering angles from 45 0 to 158 0 . The spectra reveal clearly resolved transitions at the energy loss ΔE = 33 meV which corresponds to 0→2 transitions of HD and the double transition 0→1 of HD and 0→2 of D 2 . The differential cross sections derived from these spectra increase with increasing scattering angle from 1.7% to 34.7% of the elastic cross section. The pure 0→2 transition of D 2 which only needs 22 meV to be induced could not be detected within our experimental sensitivity of 0.02 A 2 /sr. Closed coupled calculations based on the ab initio potential surface of Meyer and Schaefer show that this result can be explained by the different coupling terms which are responsible for these transitions. In contrast to the 0→1 transition the 0→2 transition of HD proved to be sensitive to the anisotropic part of the interaction potential for the homonuclear system. The comparison of experimental and calculated cross sections for the ab initio potential of Meyer and Schaefer reveals discrepancies for the 0→1 transition of HD, but shows agreement for the 0→2 transition of HD at intermediate angles

  6. H/D Isotope Effects in Hydrogen Bonded Systems

    Directory of Open Access Journals (Sweden)

    Aleksander Filarowski

    2013-04-01

    Full Text Available An extremely strong H/D isotope effect observed in hydrogen bonded A-H…B systems is connected with a reach diversity of the potential shape for the proton/deuteron motion. It is connected with the anharmonicity of the proton/deuteron vibrations and of the tunneling effect, particularly in cases of short bridges with low barrier for protonic and deuteronic jumping. Six extreme shapes of the proton motion are presented starting from the state without possibility of the proton transfer up to the state with a full ionization. The manifestations of the H/D isotope effect are best reflected in the infra-red absorption spectra. A most characteristic is the run of the relationship between the isotopic ratio nH/nD and position of the absorption band shown by using the example of NHN hydrogen bonds. One can distinguish a critical range of correlation when the isotopic ratio reaches the value of ca. 1 and then increases up to unusual values higher than . The critical range of the isotope effect is also visible in NQR and NMR spectra. In the critical region one observes a stepwise change of the NQR frequency reaching 1.1 MHz. In the case of NMR, the maximal isotope effect is reflected on the curve presenting the dependence of Δd (1H,2H on d (1H. This effect corresponds to the range of maximum on the correlation curve between dH and ΔpKa that is observed in various systems. There is a lack in the literature of quantitative information about the influence of isotopic substitution on the dielectric properties of hydrogen bond except the isotope effect on the ferroelectric phase transition in some hydrogen bonded crystals.

  7. Time dependent quantum dynamics study of the O++H2(v=0,j=0)→OH++H ion-molecule reaction and isotopic variants (D2,HD)

    International Nuclear Information System (INIS)

    Martinez, Rodrigo; Sierra, Jose Daniel; Gray, Stephen K.; Gonzalez, Miguel

    2006-01-01

    The time dependent real wave packet method using the helicity decoupling approximation was used to calculate the cross section evolution with collision energy (excitation function) of the O + +H 2 (v=0,j=0)→OH + +H reaction and its isotopic variants with D 2 and HD, using the best available ab initio analytical potential energy surface. The comparison of the calculated excitation functions with exact quantum results and experimental data showed that the present quantum dynamics approach is a very useful tool for the study of the selected and related systems, in a quite wide collision energy interval (approximately 0.0-1.1 eV), involving a much lower computational cost than the quantum exact methods and without a significant loss of accuracy in the cross sections

  8. Dynamics of the D(+) + H2HD + H(+) reaction at the low energy regime by means of a statistical quantum method.

    Science.gov (United States)

    González-Lezana, Tomás; Honvault, Pascal; Scribano, Yohann

    2013-08-07

    The D(+) +H2(v = 0, j = 0, 1) → HD+H(+) reaction has been investigated at the low energy regime by means of a statistical quantum mechanical (SQM) method. Reaction probabilities and integral cross sections (ICSs) between a collisional energy of 10(-4) eV and 0.1 eV have been calculated and compared with previously reported results of a time independent quantum mechanical (TIQM) approach. The TIQM results exhibit a dense profile with numerous narrow resonances down to Ec ~ 10(-2) eV and for the case of H2(v = 0, j = 0) a prominent peak is found at ~2.5 × 10(-4) eV. The analysis at the state-to-state level reveals that this feature is originated in those processes which yield the formation of rotationally excited HD(v' = 0, j' > 0). The statistical predictions reproduce reasonably well the overall behaviour of the TIQM ICSs at the larger energy range (Ec ≥ 10(-3) eV). Thermal rate constants are in qualitative agreement for the whole range of temperatures investigated in this work, 10-100 K, although the SQM values remain above the TIQM results for both initial H2 rotational states, j = 0 and 1. The enlargement of the asymptotic region for the statistical approach is crucial for a proper description at low energies. In particular, we find that the SQM method leads to rate coefficients in terms of the energy in perfect agreement with previously reported measurements if the maximum distance at which the calculation is performed increases noticeably with respect to the value employed to reproduce the TIQM results.

  9. Dynamics of the D++ H2HD + H+ reaction at the low energy regime by means of a statistical quantum method

    International Nuclear Information System (INIS)

    González-Lezana, Tomás; Honvault, Pascal; Scribano, Yohann

    2013-01-01

    The D + +H 2 (v= 0, j= 0, 1) → HD+H + reaction has been investigated at the low energy regime by means of a statistical quantum mechanical (SQM) method. Reaction probabilities and integral cross sections (ICSs) between a collisional energy of 10 −4 eV and 0.1 eV have been calculated and compared with previously reported results of a time independent quantum mechanical (TIQM) approach. The TIQM results exhibit a dense profile with numerous narrow resonances down to E c ∼ 10 −2 eV and for the case of H 2 (v= 0, j= 0) a prominent peak is found at ∼2.5 × 10 −4 eV. The analysis at the state-to-state level reveals that this feature is originated in those processes which yield the formation of rotationally excited HD(v′= 0, j′ > 0). The statistical predictions reproduce reasonably well the overall behaviour of the TIQM ICSs at the larger energy range (E c ⩾ 10 −3 eV). Thermal rate constants are in qualitative agreement for the whole range of temperatures investigated in this work, 10–100 K, although the SQM values remain above the TIQM results for both initial H 2 rotational states, j= 0 and 1. The enlargement of the asymptotic region for the statistical approach is crucial for a proper description at low energies. In particular, we find that the SQM method leads to rate coefficients in terms of the energy in perfect agreement with previously reported measurements if the maximum distance at which the calculation is performed increases noticeably with respect to the value employed to reproduce the TIQM results

  10. Remeasurement of p/suby/ for the 2H(d, n)3He reaction and its bearing on the reported f-wave admixture of the lowest 2- state in 4He

    International Nuclear Information System (INIS)

    Tornow, W.; Skubic, S.E.; Byrd, R.C.; Lisowski, P.W.; Walter, R.L.

    1976-01-01

    The polarization of neutrons from the reaction 2 H(d, n) 3 He has been measured for a deuteron energy E/subd/ = 2.44 MeV at emission angles of 45degree and 55degree (lab). The polarization values are discussed in relation both to previously reported discrepant data and to measured differences between p/suby/ and A/suby/ in the reaction 3 H(p, n) 3 He

  11. A testis-specific and testis developmentally regulated tumor protein D52 (TPD52)-like protein TPD52L3/hD55 interacts with TPD52 family proteins

    International Nuclear Information System (INIS)

    Cao Qinhong; Chen Jie; Zhu Li; Liu Yun; Zhou Zuomin; Sha Jiahao; Wang Shui; Li Jianmin

    2006-01-01

    Tumor protein D52-like proteins (TPD52) are small coiled-coil motif bearing proteins that were first identified in breast cancer. TPD52 and related proteins have been implicated in cell proliferation, apoptosis, and vesicle trafficking. To date, three human TPD52 members had been identified, named hD52 (TPD52), hD53 (TPD52L1), and hD54 (TPD52L2). The most important characteristic of the protein family is a highly conserved coiled-coil motif that is required for homo- and heteromeric interaction with other TPD52-like proteins. Herein, we identified a novel TPD52-like sequence (TPD52L3, or hD55) in human testis using cDNA microarray. Sequence analysis of the deduced protein suggests that hD55 contains a coiled-coil motif and is highly conserved compared with other TPD52-like sequences. Yeast two-hybrid and GST pull-down assays revealed that hD55 interacts with hD52, hD53, hD54, and itself. cDNA microarray detection found that hD55 was expressed at 5.6-fold higher levels in adult testis than in fetal testis. Additionally, the expression profile shows that hD55 is testis-specific, indicating a potential role for hD55 in testis development and spermatogenesis

  12. AtHD2D gene plays a role in plant growth, development and response to abiotic stresses in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Zhaofen eHan

    2016-03-01

    Full Text Available Abstracts: The histone deacetylases play important roles in the regulation of gene expression and the subsequent control of a number of important biological processes, including those involved in the response to environmental stress. A specific group of histone deacetylase genes, HD2, is present in plants. In Arabidopsis, HD2s include HD2A, HD2B, HD2C and HD2D. Previous research showed that HD2A, HD2B and HD2C are more related in terms of expression and function, but not HD2D. In this report, we studied different aspects of AtHD2D in Arabidopsis with respect to plant response to drought and other abiotic stresses. Bioinformatics analysis indicates that HD2D is distantly related to other HD2 genes. Transient expression in Nicotiana benthamiana and stable expression in Arabidopsis of AtHD2D fused with gfp showed that AtHD2D was expressed in the nucleus. Overexpression of AtHD2D resulted in developmental changes including fewer main roots, more lateral roots, and a higher root:shoot ratio. Seed germination and plant flowering time were delayed in transgenic plants expressing AtHD2D, but these plants exhibited higher degrees of tolerance to abiotic stresses, including drought, salt and cold stresses. Physiological studies indicated that the malondialdehyde (MDA content was high in wild-type plants but in plants overexpressing HD2D the MDA level increased slowly in response to stress conditions of drought, cold, and salt stress. Furthermore, electrolyte leakage in leaf cells of wild type plants increased but remained stable in transgenic plants. Our results indicate that AtHD2D is unique among HD2 genes and it plays a role in plant growth and development regulation and these changes can modulate plant stress responses.

  13. Small-angle neutron polarization for the /sup 2/H(d vector,n vector)/sup 3/He reaction near Esub(d) = 8MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W.; Woye, W.; Mack, G. (Tuebingen Univ. (Germany, F.R.). Physikalisches Inst.); Walter, R.L.; Floyd, C.E.; Guss, P.P.; Byrd, R.C. (Duke Univ., Durham, NC (USA). Dept. of Physics; Triangle Universities Nuclear Lab., Durham, NC (USA))

    1981-12-15

    Considerable improvement in the quality of analyzing power experiments performed with polarized fast neutrons has been achieved during the last few years by using neutrons from the polarization transfer reaction /sup 2/H(d vector,n vector)/sup 3/He at a reaction angle of theta = 0/sup 0/. To compromise in these experiments between intensity problems and finite geometry corrections, it is desirable in some instances to subtend a full-width angle ..delta..theta of 20/sup 0/ (lab) centered about theta = 0/sup 0/. In order to investigate the suitability of this reaction as a source of polarized neutrons for cases where the scatterer is close to the neutron source, the neutron polarization of the reaction /sup 2/H(d vector,n vector)/sup 3/He has been studied with ..delta..theta of about 3/sup 0/ in 3/sup 0/ steps out to theta = 20/sup 0/ (lab). An incident deuteron energy near 8 MeV was chosen to yield outgoing neutrons at 11.0 MeV, a typical energy for neutron analyzing power experiments. It is found that the effective neutron polarization, a combination of the two polarizations measured when the direction of the deuteron polarization is inverted or flipped at the polarized ion source, is large and nearly constant for angles between theta = 0/sup 0/ and theta = 10/sup 0/ (lab).

  14. Disagreement between theory and experiment grows with increasing rotational excitation of HD(v', j') product for the H + D2 reaction.

    Science.gov (United States)

    Jankunas, Justin; Sneha, Mahima; Zare, Richard N; Bouakline, Foudhil; Althorpe, Stuart C

    2013-03-07

    The Photoloc technique has been employed to measure the state-resolved differential cross sections of the HD(v', j(')) product in the reaction H + D2 over a wide range of collision energies and internal states. The experimental results were compared with fully dimensional, time-dependent quantum mechanical calculations on the refined Boothroyd-Keogh-Martin-Peterson potential energy surface. We find nearly perfect agreement between theory and experiment for HD(v', j(')) product states with low to medium rotational excitation, e.g., HD(v' = 1, j(') = 3) at a collision energy, Ecoll, of 1.72 eV, HD(v' = 1, j(') = 3, 5) at Ecoll = 1.97 eV, and HD(v' = 3, j(') = 3) at Ecoll = 1.97 eV. As the rotational angular momentum, j('), of HD(v', j(')) increases, the agreement between theoretical predictions and experimental measurements worsens but not in a simple fashion. A moderate disagreement between theory and experiment has been found for HD(v' = 0, j(') = 12) at Ecoll = 1.76 eV and increased monotonically for HD(v' = 0, j(') = 13) at Ecoll = 1.74 eV, HD(v' = 0, j(') = 14) at Ecoll = 1.72 eV, and HD(v' = 0, j(') = 15) at Ecoll = 1.70 eV. Disagreement was not limited to vibrationless HD(v', j(')) product states: HD(v' = 1, j(') = 12) at Ecoll = 1.60 eV and HD(v' = 3, j(') = 8, 10) at Ecoll = 1.97 eV followed a similar trend. Theoretical calculations suggest more sideways∕forward scattering than has been observed experimentally for high j(') HD(v', j(')) states. The source of this discrepancy is presently unknown but might be the result of inaccuracy in the potential energy surface.

  15. 2D heterodyne-detected sum frequency generation study on the ultrafast vibrational dynamics of H{sub 2}O and HOD water at charged interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Ken-ichi; Singh, Prashant C. [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nihonyanagi, Satoshi; Tahara, Tahei, E-mail: tahei@riken.jp [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, Shoichi [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Applied Chemistry, Saitama University, 255 Shimo-Okubo, Saitama 338-8570 (Japan)

    2015-06-07

    Two-dimensional heterodyne-detected vibrational sum-frequency generation (2D HD-VSFG) spectroscopy is applied to study the ultrafast vibrational dynamics of water at positively charged aqueous interfaces, and 2D HD-VSFG spectra of cetyltrimethylammonium bromide (CTAB)/water interfaces in the whole hydrogen-bonded OH stretch region (3000 cm{sup −1} ≤ ω{sub pump} ≤ 3600 cm{sup −1}) are measured. 2D HD-VSFG spectrum of the CTAB/isotopically diluted water (HOD-D{sub 2}O) interface exhibits a diagonally elongated bleaching lobe immediately after excitation, which becomes round with a time constant of ∼0.3 ps due to spectral diffusion. In contrast, 2D HD-VSFG spectrum of the CTAB/H{sub 2}O interface at 0.0 ps clearly shows two diagonal peaks and their cross peaks in the bleaching region, corresponding to the double peaks observed at 3230 cm{sup −1} and 3420 cm{sup −1} in the steady-state HD-VSFG spectrum. Horizontal slices of the 2D spectrum show that the relative intensity of the two peaks of the bleaching at the CTAB/H{sub 2}O interface gradually change with the change of the pump frequency. We simulate the pump-frequency dependence of the bleaching feature using a model that takes account of the Fermi resonance and inhomogeneity of the OH stretch vibration, and the simulated spectra reproduce the essential features of the 2D HD-VSFG spectra of the CTAB/H{sub 2}O interface. The present study demonstrates that heterodyne detection of the time-resolved VSFG is critically important for studying the ultrafast dynamics of water interfaces and for unveiling the underlying mechanism.

  16. Acetone and Water on TiO(110): H/D Exchange

    International Nuclear Information System (INIS)

    Henderson, Michael A.

    2005-01-01

    Isotopic H/D exchange between coadsorbed acetone and water on the TiO(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in the high temperature region of the d?-acetone TPD spectrum at ∼340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above ∼0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at ∼390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H/D exchange

  17. Slow Histidine H/D Exchange Protocol for Thermodynamic Analysis of Protein Folding and Stability using Mass Spectrometry

    OpenAIRE

    Tran, Duc T.; Banerjee, Sambuddha; Alayash, Abdu I.; Crumbliss, Alvin L.; Fitzgerald, Michael C.

    2012-01-01

    Described here is a mass spectrometry based protocol to study the thermodynamic stability of proteins and protein-ligand complexes using the slow H/D exchange reaction of the imidazole C2 proton in histidine side chains. The protocol, which involves evaluating the denaturant dependence of this slow H/D exchange reaction in proteins, allows the global and/or subglobal unfolding/refolding properties of proteins and protein-ligand complexes to be probed. The protocol is developed using several m...

  18. Response-function measurement of an NE213 scintillator using the [sup 2]H(d, n)[sup 3]He reaction

    Energy Technology Data Exchange (ETDEWEB)

    Aksoy, A. (Energy Research Lab., King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)); Coban, A. (Energy Research Lab., King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)); Naqvi, A.A. (Energy Research Lab., King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)); Khiari, F.Z. (Energy Research Lab., King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)); Hanly, J.M. (Duke Univ., Nuclear Labs., Durham, NC (United States)); Howell, C.R. (Duke Univ., Nuclear Labs., Durham, NC (United States)); Tornow, W. (Duke Univ., Nuclear Labs., Durham, NC (United States)); Felsher, P.D. (Duke Univ., Nuclear Labs., Durham, NC (United States)); Al-Ohali, M.A. (Duke Univ., Nuclear Labs., Durham, NC (United States)); Walter, R.L. (Duke Univ., Nuclear Labs., Durham, NC (United States))

    1994-01-01

    The response function of a 12.5 cm diameter NE213 scintillator detector has been measured over neutron energies ranging from 4.9 to 16.6 MeV. Beams of monoenergetic neutrons were produced using the [sup 2]H(d, n)[sup 3]He reaction. The response function is about 12% lower than previously reported values for a similar detector obtained using a continuous spectrum of neutrons from a [sup 252]Cf fission source. However, the present response function agrees with portions of data sets obtained in published work that used monoenergetic neutron source reactions. (orig.)

  19. Conformations of cationized linear oligosaccharides revealed by FTMS combined with in-ESI H/D exchange.

    Science.gov (United States)

    Kostyukevich, Yury; Kononikhin, Alexey; Popov, Igor; Nikolaev, Eugene

    2015-10-01

    Previously (Kostyukevich et al. Anal Chem 2014, 86, 2595), we have reported that oligosaccharides anions are produced in the electrospray in two different conformations, which differ by the rate of gas phase hydrogen/deuterium (H/D) exchange reaction. In the present paper, we apply the in-electrospray ionization (ESI) source H/D exchange approach for the investigation of the oligosaccharides cations formed by attaching of metal ions (Na, K) to the molecule. It was observed that the formation of different conformers can be manipulated by varying the temperature of the desolvating capillary of the ESI interphase. Separation of the conformers was performed using gas phase H/D approach. Because the conformers have different rates of the H/D exchange reaction, the deuterium distribution spectrum becomes bimodal. It was found that the conformation corresponding to the slow H/D exchange rate dominates in the spectrum when the capillary temperature is low (~200 °C), and the conformation corresponding to the fast H/D exchange rate dominates at high (~400 °C) temperatures. In the intermediate temperature region, two conformers are present simultaneously. It was also observed that large oligosaccharide requires higher temperature for the formation of another conformer. It was found that the presence of the conformers considerably depends on the solvent used for ESI and the pH. We have compared these results with the previously performed in-ESI source H/D exchange experiments with peptides and proteins. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Precision spectroscopy of the X1Σg+, v=0→1(J=0-2) rovibrational splittings in H2, HD and D2

    Science.gov (United States)

    Niu, M. L.; Salumbides, E. J.; Dickenson, G. D.; Eikema, K. S. E.; Ubachs, W.

    2014-06-01

    Accurate experimental values for the vibrational ground tone or fundamental vibrational energy splitting of H2, HD, and D2 are presented. Absolute accuracies of 2×10-4 cm-1 are obtained from Doppler-free laser spectroscopy applied in a collisionless environment. The vibrational splitting frequencies are derived from the combination difference between separate electronic excitations from the X1Σg+, v=0, J and v=1, J vibrational states to a common EF1Σg+, v=0, J state. The present work on rotational quantum states J=1,2 extends the results reported by Dickenson et al. on J=0 [Phys. Rev. Lett. 110 (2013) 193601]. The experimental procedures leading to this high accuracy are discussed in detail. A comparison is made with full ab initio calculations encompassing Born-Oppenheimer energies, adiabatic and non-adiabatic corrections, as well as relativistic corrections and QED-contributions. The present agreement between the experimental results and the calculations provides a stringent test on the application of quantum electrodynamics in molecules. Furthermore, the combined experimental-theoretical uncertainty can be interpreted to provide bounds to new interactions beyond the Standard Model of Physics or fifth forces between hadrons.

  1. Quantum approaches for the insertion dynamics of the H++D2 and D++H2 reactive collisions

    International Nuclear Information System (INIS)

    Gonzalez-Lezana, Tomas; Aguado, Alfredo; Paniagua, Miguel; Roncero, O.

    2005-01-01

    The H + +D 2 and D + +H 2 reactive collisions are studied using a recently proposed adiabatic potential energy surface of spectroscopic accuracy. The dynamics is studied using an exact wave packet method on the adiabatic surface at energies below the curve crossing occurring at ≅1.5 eV above the threshold. It is found that the reaction is very well described by a statistical quantum method for a zero total angular momentum (J) as compared with the exact ones, while for higher J some discrepancies are found. For J>0 different centrifugal sudden approximations are proposed and compared with the exact and statistical quantum treatments. The usual centrifugal sudden approach fails by considering too high reaction barriers and too low reaction probabilities. A new statistically modified centrifugal sudden approach is considered which corrects these two failures to a rather good extent. It is also found that an adiabatic approximation for the helicities provides results in very good agreement with the statistical method, placing the reaction barrier properly. However, both statistical and adiabatic centrifugal treatments overestimate the reaction probabilities. The reaction cross sections thus obtained with the new approaches are in rather good agreement with the exact results. In spite of these deficiencies, the quantum statistical method is well adapted for describing the insertion dynamics, and it is then used to evaluate the differential cross sections

  2. Some measurements of H/D polarizability isotope effects using differential refractometry

    Energy Technology Data Exchange (ETDEWEB)

    Foster Smith, M; Van Hook, W A [Tennessee Univ., Knoxville (USA). Dept. of Chemistry

    1989-05-01

    Refractive index differences between the H and D isomers of some common molecules in the liquid phase were measured between 404.7 and 690.0 nm. The data are combined with information on molar volume isotope effects to yield values for H/D isotope effects on the static polarizability, the vibrational contribution to the static and frequency dependent parts of the polarizability, and the H/D isotope effect on the second moment of the electronic charge distribution. The present results suffice to demonstrate the practicability of this technique to measure the components of the polarizability listed above. However for accurate resolution of the vibrational and second moment contributions, refractive index data of still greater precision will be required. (orig.).

  3. Some measurements of H/D polarizability isotope effects using differential refractometry

    International Nuclear Information System (INIS)

    Foster Smith, M.; Van Hook, W.A.

    1989-01-01

    Refractive index differences between the H and D isomers of some common molecules in the liquid phase were measured between 404.7 and 690.0 nm. The data are combined with information on molar volume isotope effects to yield values for H/D isotope effects on the static polarizability, the vibrational contribution to the static and frequency dependent parts of the polarizability, and the H/D isotope effect on the second moment of the electronic charge distribution. The present results suffice to demonstrate the practicability of this technique to measure the components of the polarizability listed above. However for accurate resolution of the vibrational and second moment contributions, refractive index data of still greater precision will be required. (orig.)

  4. Dynamics of the D{sup +}+ H{sub 2}→ HD + H{sup +} reaction at the low energy regime by means of a statistical quantum method

    Energy Technology Data Exchange (ETDEWEB)

    González-Lezana, Tomás [Instituto de Física Fundamental, IFF-CSIC, Serrano 123, 28006 Madrid (Spain); Honvault, Pascal [Lab. Interdisciplinaire Carnot de Bourgogne, UMR CNRS 6303, Univ. Bourgogne, 21078 Dijon Cedex, France and UFR Sciences et Techniques, Univ. de Franche-Comté, 25030 Besançon cedex (France); Scribano, Yohann [Lab. Univers et Particules de Montpellier, Univ. de Montpellier II, LUPM - UMR CNRS 5299, 34095 Montpellier Cedex (France)

    2013-08-07

    The D{sup +}+H{sub 2}(v= 0, j= 0, 1) → HD+H{sup +} reaction has been investigated at the low energy regime by means of a statistical quantum mechanical (SQM) method. Reaction probabilities and integral cross sections (ICSs) between a collisional energy of 10{sup −4} eV and 0.1 eV have been calculated and compared with previously reported results of a time independent quantum mechanical (TIQM) approach. The TIQM results exhibit a dense profile with numerous narrow resonances down to E{sub c}∼ 10{sup −2} eV and for the case of H{sub 2}(v= 0, j= 0) a prominent peak is found at ∼2.5 × 10{sup −4} eV. The analysis at the state-to-state level reveals that this feature is originated in those processes which yield the formation of rotationally excited HD(v′= 0, j′ > 0). The statistical predictions reproduce reasonably well the overall behaviour of the TIQM ICSs at the larger energy range (E{sub c}⩾ 10{sup −3} eV). Thermal rate constants are in qualitative agreement for the whole range of temperatures investigated in this work, 10–100 K, although the SQM values remain above the TIQM results for both initial H{sub 2} rotational states, j= 0 and 1. The enlargement of the asymptotic region for the statistical approach is crucial for a proper description at low energies. In particular, we find that the SQM method leads to rate coefficients in terms of the energy in perfect agreement with previously reported measurements if the maximum distance at which the calculation is performed increases noticeably with respect to the value employed to reproduce the TIQM results.

  5. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    KAUST Repository

    Zhao, Yujun; Lim, XiaoZhi; Pan, Yuanhang; Zong, Lili; Feng, Wei; Tan, Choonhong; Huang, Kuo-Wei

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction's stereoselectivity. © 2012 The Royal Society of Chemistry.

  6. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    KAUST Repository

    Zhao, Yujun

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction\\'s stereoselectivity. © 2012 The Royal Society of Chemistry.

  7. Energy-sensitive imaging detector applied to the dissociative recombination of D2H+

    International Nuclear Information System (INIS)

    Buhr, H.; Schwalm, D.; Mendes, M. B.; Novotny, O.; Berg, M. H.; Bing, D.; Krantz, C.; Orlov, D. A.; Sorg, T.; Stuetzel, J.; Varju, J.; Wolf, A.; Heber, O.; Rappaport, M. L.; Zajfman, D.

    2010-01-01

    We report on an energy-sensitive imaging detector for studying the fragmentation of polyatomic molecules in the dissociative recombination of fast molecular ions with electrons. The system is based on a large area (10x10 cm 2 ) position-sensitive, double-sided Si-strip detector with 128 horizontal and 128 vertical strips, whose pulse height information is read out individually. The setup allows us to uniquely identify fragment masses and is thus capable of measuring branching ratios between different fragmentation channels, kinetic energy releases, and breakup geometries as a function of the relative ion-electron energy. The properties of the detection system, which has been installed at the Test Storage Ring (TSR) facility of the Max-Planck Institute for Nuclear Physics in Heidelberg, is illustrated by an investigation of the dissociative recombination of the deuterated triatomic hydrogen cation D 2 H + . A huge isotope effect is observed when comparing the relative branching ratio between the D 2 + H and the HD + D channel; the ratio 2B(D 2 + H)/B(HD + D), which is measured to be 1.27±0.05 at relative electron-ion energies around 0 eV, is found to increase to 3.7±0.5 at ∼5 eV.

  8. Energy-sensitive imaging detector applied to the dissociative recombination of D2H+

    Science.gov (United States)

    Buhr, H.; Mendes, M. B.; Novotný, O.; Schwalm, D.; Berg, M. H.; Bing, D.; Heber, O.; Krantz, C.; Orlov, D. A.; Rappaport, M. L.; Sorg, T.; Stützel, J.; Varju, J.; Wolf, A.; Zajfman, D.

    2010-06-01

    We report on an energy-sensitive imaging detector for studying the fragmentation of polyatomic molecules in the dissociative recombination of fast molecular ions with electrons. The system is based on a large area (10×10 cm2) position-sensitive, double-sided Si-strip detector with 128 horizontal and 128 vertical strips, whose pulse height information is read out individually. The setup allows us to uniquely identify fragment masses and is thus capable of measuring branching ratios between different fragmentation channels, kinetic energy releases, and breakup geometries as a function of the relative ion-electron energy. The properties of the detection system, which has been installed at the Test Storage Ring (TSR) facility of the Max-Planck Institute for Nuclear Physics in Heidelberg, is illustrated by an investigation of the dissociative recombination of the deuterated triatomic hydrogen cation D2H+. A huge isotope effect is observed when comparing the relative branching ratio between the D2 + H and the HD + D channel; the ratio 2B(D2 + H)/B(HD + D), which is measured to be 1.27±0.05 at relative electron-ion energies around 0 eV, is found to increase to 3.7±0.5 at ~5 eV.

  9. Chemical reaction dynamics of Rydberg atoms with neutral molecules: A comparison of molecular-beam and classical trajectory results for the H(n)+D2HD+D(n') reaction

    International Nuclear Information System (INIS)

    Song Hui; Dai Dongxu; Wu Guorong; Wang, C.-C.; Harich, Steven A.; Hayes, Michael Y.; Wang Xiuyan; Gerlich, Dieter; Yang Xueming; Skodje, Rex T.

    2005-01-01

    Recent molecular-beam experiments have probed the dynamics of the Rydberg-atom reaction, H(n)+D 2HD+D(n) at low collision energies. It was discovered that the rotationally resolved product distribution was remarkably similar to a much more limited data set obtained at a single scattering angle for the ion-molecule reaction H + +D 2D + +HD. The equivalence of these two problems would be consistent with the Fermi-independent-collider model (electron acting as a spectator) and would provide an important new avenue for the study of ion-molecule reactions. In this work, we employ a classical trajectory calculation on the ion-molecule reaction to facilitate a more extensive comparison between the two systems. The trajectory simulations tend to confirm the equivalence of the ion+molecule dynamics to that for the Rydberg-atom+molecule system. The theory reproduces the close relationship of the two experimental observations made previously. However, some differences between the Rydberg-atom experiments and the trajectory simulations are seen when comparisons are made to a broader data set. In particular, the angular distribution of the differential cross section exhibits more asymmetry in the experiment than in the theory. The potential breakdown of the classical model is discussed. The role of the 'spectator' Rydberg electron is addressed and several crucial issues for future theoretical work are brought out

  10. Competition H(D) kinetic isotope effects in the autoxidation of hydrocarbons.

    Science.gov (United States)

    Muchalski, Hubert; Levonyak, Alexander J; Xu, Libin; Ingold, Keith U; Porter, Ned A

    2015-01-14

    Hydrogen atom transfer is central to many important radical chain sequences. We report here a method for determination of both the primary and secondary isotope effects for symmetrical substrates by the use of NMR. Intramolecular competition reactions were carried out on substrates having an increasing number of deuterium atoms at symmetry-related sites. Products that arise from peroxyl radical abstraction at each position of the various substrates reflect the competition rates for H(D) abstraction. The primary KIE for autoxidation of tetralin was determined to be 15.9 ± 1.4, a value that exceeds the maximum predicted by differences in H(D) zero-point energies (∼7) and strongly suggests that H atom abstraction by the peroxyl radical occurs with substantial quantum mechanical tunneling.

  11. Kinetic Investigation of Homogeneous H(2)-D(2) Equilibration Catalyzed by Pt-Au Cluster Compounds. Characterization of the Cluster [(H)Pt(AuPPh(3))(9)](NO(3))(2).

    Science.gov (United States)

    Rubinstein, Leon I.; Pignolet, Louis H.

    1996-11-06

    The new Pt-Au hydrido cluster compound [(H)Pt(AuPPh(3))(9)](NO(3))(2) (3) has been synthesized and characterized by NMR, FABMS, and single-crystal X-ray diffraction [triclinic, P&onemacr;, a = 17.0452(1) Å, b = 17.4045(2) Å, c = 55.2353(1) Å, alpha = 89.891(1) degrees, beta = 85.287(1) degrees, gamma = 75.173(1) degrees, V = 15784.0(2) Å(3), Z = 4 (two molecules in asymmetric unit), residual R = 0.089 for 45 929 observed reflections and 3367 variables, Mo Kalpha radiation]. The Pt(AuP)(9) core geometry is a distorted icosahedron with three vertices vacant. The Pt-Au, Au-Au, and Au-P distances are within the normal ranges observed in other Pt-Au clusters. This cluster is a catalyst for H(2)-D(2) equilibration in homogeneous solution phase and has been used in a general mechanistic study of this reaction catalyzed by Pt-Au clusters. We previously proposed that a key step in the mechanism for catalytic H(2)-D(2) equilibration is the dissociation of a PPh(3) ligand to give a cluster with an open Au site for bonding of H(2) or D(2). This was based on qualitative observations that PPh(3) inhibited the rate of HD production with [Pt(AuPPh(3))(8)](NO(3))(2) (1) as catalyst. In order to test this hypothesis, phosphine inhibition (on the rate of HD production) and phosphine ligand exchange kinetic experiments were carried out with [(H)(PPh(3))Pt(AuPPh(3))(7)](NO(3))(2) (2) and 3. In this paper we show that the rate constant for phosphine dissociation determined from the PPh(3) inhibition rate study of H(2)-D(2) equilibration with cluster 2 is nearly identical to the rate constant for dissociative phosphine ligand exchange. The slower rate for H(2)-D(2) equilibration observed with 3 compared with 2 (5.5 x 10(-3) vs 7.7 x 10(-2) turnover s(-1)) is explained by its smaller rate constant for phosphine dissociation (2.8 x 10(-5) vs 2.9 x 10(-4) s(-1)). The fact that clusters 2 and 3 show similar kinetic behaviors suggests that the PPh(3) dissociation step in the catalytic H(2

  12. Improved results for the 2H(d, n)3He transverse vector polarization-transfer coefficient Kyy'(0o) at low energies

    International Nuclear Information System (INIS)

    Roper, C.D.; Dunham, J.D.; Clegg, T.B.; Mendez, A.J.; Tornow, W.; Walter, R.L.

    2010-01-01

    Measurements of the 2 H(d, n) 3 He transverse vector polarization-transfer coefficient K y y' at 0 o . are reported for 29 outgoing neutron energies between 3.94 and 8.47 MeV. Our new results determine K y y' (0 o ) more accurately than previous data, especially for neutron energies below 5 MeV. Low-energy data for this reaction are important both as a high-intensity source of highly polarized neutrons for nuclear physics studies with polarized neutron beams, and as a test of the emerging theoretical descriptions of the four-body system, where recently substantial progress has been made. (author)

  13. Cross sections of the O++H2→OH++H ion-molecule reaction and isotopic variants (D2, HD): Quasiclassical trajectory study and comparison with experiments

    International Nuclear Information System (INIS)

    Martinez, Rodrigo; Sierra, Jose Daniel; Gonzalez, Miguel

    2005-01-01

    A dynamics study [cross section and microscopic mechanism versus collision energy (E T )] of the reaction O + +H 2 →OH + +H, which plays an important role in Earth's ionosphere and interstellar chemistry, was conducted using the quasiclassical trajectory method, employing an analytical potential energy surface (PES) recently derived by our group [R. Martinez et al., J. Chem. Phys. 120, 4705 (2004)]. Experimental excitation functions for the title reaction, as well as its isotopic variants with D 2 and HD, were near-quantitatively reproduced in the calculations in the very broad collision energy range explored (E T =0.01-6.0 eV). Intramolecular and intermolecular isotopic effects were also examined, yielding data in good agreement with experimental results. The reaction occurs via two microscopic mechanisms (direct and nondirect abstraction). The results were satisfactorily interpreted based on the reaction probability and the maximum impact parameter dependences with E T , and considering the influence of the collinear [OHH] + absolute minimum of the PES on the evolution from reactants to products. The agreement between theory and experiment suggests that the reaction mainly occurs through the lowest energy PES and nonadiabatic processes are not very important in the wide collision energy range analyzed. Hence, the PES used to describe this reaction is suitable for both kinetics and dynamics studies

  14. Increased H2CO production in the outer disk around HD 163296

    Science.gov (United States)

    Carney, M. T.; Hogerheijde, M. R.; Loomis, R. A.; Salinas, V. N.; Öberg, K. I.; Qi, C.; Wilner, D. J.

    2017-09-01

    Context. The gas and dust in circumstellar disks provide the raw materials to form planets. The study of organic molecules and their building blocks in such disks offers insight into the origin of the prebiotic environment of terrestrial planets. Aims: We aim to determine the distribution of formaldehyde, H2CO, in the disk around HD 163296 to assess the contribution of gas- and solid-phase formation routes of this simple organic. Methods: Three formaldehyde lines were observed (H2CO 303-202, H2CO 322-221, and H2CO 321-220) in the protoplanetary disk around the Herbig Ae star HD 163296 with ALMA at 0.5″ (60 AU) spatial resolution. Different parameterizations of the H2CO abundance were compared to the observed visibilities, using either a characteristic temperature, a characteristic radius or a radial power law index to describe the H2CO chemistry. Similar models were applied to ALMA Science Verification data of C18O. In each scenario, χ2 minimization on the visibilities was used to determine the best-fit model in each scenario. Results: H2CO 303-202 was readily detected via imaging, while the weaker H2CO 322-221 and H2CO 321-220 lines required matched filter analysis to detect. H2CO is present throughout most of the gaseous disk, extending out to 550 AU. An apparent 50 AU inner radius of the H2CO emission is likely caused by an optically thick dust continuum. The H2CO radial intensity profile shows a peak at 100 AU and a secondary bump at 300 AU, suggesting increased production in the outer disk. In all modeling scenarios, fits to the H2CO data show an increased abundance in the outer disk. The overall best-fit H2CO model shows a factor of two enhancement beyond a radius of 270 ± 20 AU, with an inner abundance (relative to H2) of 2 - 5 × 10-12. The H2CO emitting region has a lower limit on the kinetic temperature of T> 20 K. The C18O modeling suggests an order of magnitude depletion of C18O in the outer disk and an abundance of 4 - 12 × 10-8 in the inner disk

  15. Water as a solute in aprotic dipolar solvents. 2. D2O-H2O solute isotope effects on the enthalpy of water dissolution in nitromethane, acetonitrile and propylene carbonate at 298.15 K

    International Nuclear Information System (INIS)

    Ivanov, Evgeniy V.; Smirnov, Valeriy I.

    2010-01-01

    The enthalpies of solution of ordinary (H 2 O) and heavy (D 2 O) water in nitromethane (NM), acetonitrile (ACN) and propylene carbonate (PC) were measured calorimetrically at 298.15 K. Standard (at the infinite dilution) enthalpies of solution and solvation, along with D 2 O-H 2 O solute isotope effects on the quantities in question, were calculated. The enthalpies of solution of water H/D isotopologues were found to be positive by sign and substantially increasing in magnitude on going from ACN and PC to NM, whereas the corresponding positive solute H/D isotope effect changes in a consequence: NM > ACN > PC. The qualitative interrelations between the enthalpy-isotopic effect of dissolution (solvation) of water and the electron-accepting/donating ability of aprotic dipolar solvent (within a series considered) were found.

  16. Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D Exchange Monitored by FT-ICR Mass Spectrometry

    Science.gov (United States)

    Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.

    2013-07-01

    The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

  17. State-to-state quantum mechanical calculations of rate coefficients for the D+ + H2HD + H+ reaction at low temperature.

    Science.gov (United States)

    Honvault, P; Scribano, Y

    2013-10-03

    The dynamics of the D(+) + H2HD + H(+) reaction on a recent ab initio potential energy surface (Velilla, L.; Lepetit, B.; Aguado, A.; Beswick, J. A.; Paniagua, M. J. Chem. Phys. 2008, 129, 084307) has been investigated by means of a time-independent quantum mechanical approach. Cross-sections and rate coefficients are calculated, respectively, for collision energies below 0.1 eV and temperatures up to 100 K for astrophysical application. An excellent accord is found for collision energy above 5 meV, while a disagreement between theory and experiment is observed below this energy. We show that the rate coefficients reveal a slightly temperature-dependent behavior in the upper part of the temperature range considered here. This is in agreement with the experimental data above 80 K, which give a temperature independent value. However, a significant decrease is found at temperatures below 20 K. This decrease can be related to quantum effects and the decay back to the reactant channel, which are not considered by simple statistical approaches, such as the Langevin model. Our results have been fitted to appropriate analytical expressions in order to be used in astrochemical and cosmological models.

  18. H?, D? and HD adsorption upon the metal-organic framework [Cu?Zn?(btc)?]? studied by pulsed ENDOR and HYSCORE spectroscopy

    Science.gov (United States)

    Jee, Bettina; Hartmann, Martin; Pöppl, Andreas

    2013-10-01

    The adsorption of hydrogen has become interesting in terms of gas separation as well as safe and reversible storage of hydrogen as an energy carrier. In this regard, metal-organic framework compounds are potential candidates. The metal-organic framework [Cu?Zn?(btc)?]? as a partially Zn-substituted analogue of the well known compound HKUST-1 is well suited for studying adsorption geometries at cupric ions by electron paramagnetic resonance (EPR) methods due to the formation of few mixed Cu/Zn paddle wheel units with isolated S = 1/2 electron spins. The adsorption of hydrogen (H2) as well as the deuterium (D2) and HD molecules were investigated by continuous wave EPR and pulsed ENDOR and HYSCORE spectroscopy. The principal values of the proton and deuterium hyperfine coupling tensors ? and ? were determined by spectral simulations as well as of the deuterium nuclear quadrupole tensor ? for adsorbed HD and D2. The results show a side-on coordination of HD and D2 with identical Cu-H and Cu-D distances rCuX = 2.8 Å with the tensors ? and ? aligned parallel to the C4 symmetry axis of the paddle wheel unit. A thermodynamic non-equilibrium state with J = 1, mJ = ±1 is indicated by the experimental data with ? and ? averaged by rotation around C4.

  19. Fusion with highly spin polarized HD and D2

    International Nuclear Information System (INIS)

    Honig, A.; Letzring, S.; Skupsky, S.

    1993-01-01

    Our experimental efforts over the past 5 years have been aimed at cazrying out ICF shots with spin-polarized 0 fuel. We successfully prepared polarized 0 in HD, and solved the problems of loading target shells with our carefully prepared isotopic -rnixt.l.l?-es, polarizing them so that the 0 polarization remains metastably frozen-in for about half a day, and carrying out the various cold transfer requirements at Syracuse, where the target is prepared, and at Rochester, where the cold target is inserted fusion chamber. Upon shooting the accurately positioned unpolarized high density cold target, no neutron yield was observed. Inspection inside the OMEGA tank after the shot indicated the absence of neutron yield was dus to mal-timing or insufficient retraction rate of OMEGA'S fast shroud mechanism, resulting in interception of at least 20 of the 24 laser beams by the faulty shroud. In spits of this, all alements of the complex experiment we originally undertook have been successfully demonstrated, and the cold retrieval concepts and methods we developed are being utilized on the ICF upgrades at Rochester and at Livermore. In addition to the solution of the interface problems, we obtained novel results on polymer shell characteristics at low temperatures, and continuation of these experiments is c = ently supported by KLUP. Extensive additional mappings were ca=ied out of nuclear spin relaxation rates of H and D in solid HD in the temperature-magnetic field rangs of 0.01 to 4.2K and 0 - 13 Tesla. New phenomena were discovered, such as association of impurity clustering with very low temperature motion, and inequality of the growth-rate and decay-rate of the magnetization

  20. Interplay between crystal and magnetic structures in YFe{sub 2}(H{sub α}D{sub 1−α}){sub 4.2} compounds studied by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Boncour, V., E-mail: paulbon@icmpe.cnrs.fr [Université de Paris Est, ICMPE, CNRS-UPEC, UMR7182, 2-8 rue Henri Dunant, 94320 Thiais (France); Guillot, M. [LNCMI, CNRS, BP166, 38042 Grenoble Cedex 9 (France); Isnard, O. [CNRS, Institut Néel, 38042 Grenoble (France); Univ. Grenoble Alpes, Inst. Néel, 38042 Grenoble (France); Ouladdiaf, B. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Hoser, A. [Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-141 09 Berlin (Germany); Hansen, T. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Stuesser, N. [Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-141 09 Berlin (Germany)

    2017-01-15

    We report a detailed magnetic structure investigation of YFe{sub 2}(H{sub α}D{sub 1−α}){sub 4.2} (α=0, 0.64, 1) compounds presenting a strong (H,D) isotope effect by neutron diffraction and Mössbauer spectroscopy analysis. They crystallize in the same monoclinic structure (Pc space group) with 8 inequivalent Fe sites having different H(D) environment. At low temperature, the compounds are ferromagnetic (FM) and show an easy magnetization axis perpendicular to the b axis and only slightly tilted away from the c axis. Upon heating, they display a first order transition from a ferromagnetic towards an antiferromagnetic (AFM) structure at T{sub M0} which is sensitive to the H/D isotope nature. The AFM cell is described by doubling the crystal cell along the monoclinic b axis. It presents an unusual coexistence of non magnetic Fe layer sandwiched by two thicker ferromagnetic Fe layers which are antiparallel to each other. This FM-AFM transition is driven by the loss of ordered moment on one Fe site (Fe7) through an itinerant electron metamagnetic (IEM) behaviour. The key role of the Fe7 position is assigned to both its hydrogen rich atomic environment and its geometric position. Above T{sub M0} a field induced metamagnetic transition is observed from the AFM towards the FM structure accompanied by a cell volume increase. Both thermal and magnetic field dependence of the magnetic structure are found strongly related to the anisotropic cell distortion induced by (H,D) order in interstitial sites. - Graphical abstract: Representation of the FM-AFM magnetic structures of YFe{sub 2}D{sub 4.2} deuteride. - Highlights: • YFe{sub 2}(H,D){sub 4.2} compounds undergoes a isotope sensitive FM-AFM transition at T{sub M0}. • The FM structure is formed of Fe moments perpendicular to the monoclinic b axis. • AFM structure is formed by antiparallel Fe layers separated by non-magnetic Fe layer. • One Fe site among eight loses its moment at T{sub M0} due to larger Fe–H

  1. Diffusion Monte Carlo simulations of gas phase and adsorbed D2-(H2)n clusters

    Science.gov (United States)

    Curotto, E.; Mella, M.

    2018-03-01

    We have computed ground state energies and analyzed radial distributions for several gas phase and adsorbed D2(H2)n and HD(H2)n clusters. An external model potential designed to mimic ionic adsorption sites inside porous materials is used [M. Mella and E. Curotto, J. Phys. Chem. A 121, 5005 (2017)]. The isotopic substitution lowers the ground state energies by the expected amount based on the mass differences when these are compared with the energies of the pure clusters in the gas phase. A similar impact is found for adsorbed aggregates. The dissociation energy of D2 from the adsorbed clusters is always much higher than that of H2 from both pure and doped aggregates. Radial distributions of D2 and H2 are compared for both the gas phase and adsorbed species. For the gas phase clusters, two types of hydrogen-hydrogen interactions are considered: one based on the assumption that rotations and translations are adiabatically decoupled and the other based on nonisotropic four-dimensional potential. In the gas phase clusters of sufficiently large size, we find the heavier isotopomer more likely to be near the center of mass. However, there is a considerable overlap among the radial distributions of the two species. For the adsorbed clusters, we invariably find the heavy isotope located closer to the attractive interaction source than H2, and at the periphery of the aggregate, H2 molecules being substantially excluded from the interaction with the source. This finding rationalizes the dissociation energy results. For D2-(H2)n clusters with n ≥12 , such preference leads to the desorption of D2 from the aggregate, a phenomenon driven by the minimization of the total energy that can be obtained by reducing the confinement of (H2)12. The same happens for (H2)13, indicating that such an effect may be quite general and impact on the absorption of quantum species inside porous materials.

  2. Formation of H_2^+ and its Isotopomers by Radiative Association: the Role of Shape and Feshbach Resonances

    Science.gov (United States)

    Beyer, Maximilian; Merkt, Frederic

    2017-06-01

    The recent observations [1,2] of shape and Feshbach resonances in the high-resolution photoelectron spectra of H_2, HD and D_2 in the vicinity of the dissociation thresholds of H_2^+, HD^+ and D_2^+ raise questions concerning their potential role in the formation of H_2^+ and its isotopomers in the early universe by radiative association, a topic of astrophysical interest [3]. Close-coupling calculations for the cross sections of the reactions {H}^+ + {H} &\\to {H}_2^+ + hν {H}^+ + {D} &\\to {HD}^+ + hν {D}^+ + {H} &\\to {HD}^+ + hν {D}^+ + {D} &\\to {D}_2^+ + hν, will be presented which take into account nonadiabatic couplings involving rovibronic and hyperfine interactions, as well as relativistic and radiative corrections. The calculated energies and widths will be compared with the experimental results of Ref. [1,2] for H_2^+ and new data for HD^+ and D_2^+. The effect of the resonances on the radiative association rate coefficients will be discussed, also in comparison with earlier studies [4]. [1] M. Beyer and F. Merkt, Phys. Rev. Lett. 116, 093001 (2016). [2] M. Beyer and F. Merkt, J. Mol. Spectrosc. 330, 147 (2016). [3] Molecule formation in dust-poor environments, J. F. Babb and K. P. Kirby, in "The molecular astrophysics of stars and galaxies", T. W. Hartquist and D. A. Williams, eds., Oxford University Press, Oxford, 1998, pp. 11-34. [4] D. E. Ramaker and J. M. Peek, Phys. Rev. A 13, 58 (1976).

  3. Cross sections for ion production in reactions of H+ with D2; Effects of vibrational and rotational excited states of D2

    OpenAIRE

    市原 晃; 岩本 修; 横山 啓一

    1998-01-01

    H+とD2の反応で生じるD2+,D+及びHD+イオン生成の断面積を、重心衝突エネルギーEcm=2.5-8.0eVの範囲内で、非経験的分子軌道計算で得られたH3+の3次元ポテンシャル面上でのトラジェクトリーサーフェスホッピング(TSH)法を用いることにより、評価した。反応物D2の初期状態が各イオン生成に与える影響を調べるために、D2の振動及び回転の量子数をv=0-3,j=1,5,10に設定して計算を行った。その結果、D2+イオンの生成は、D2の振動回転状態(v,j)が高くなるに従って著しく増大することが分かった。D2+生成の飛躍的な増大には、D2の振動励起が主要な役割を果たし、回転励起は補助的な効果を与えた。D2+生成と比較して、D2の振動状態がD+及びHD+イオンの生成に与える効果は一桁小さく、D2の回転状態に対する効果は殆ど無視しうる大きさであった。...

  4. Reactive scattering for H{sup -} + H{sub 2} and H{sup +} + H{sub 2} and its isotopologues. Classical versus quantum investigation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dequan

    2016-07-01

    reaction preferentially occurs adiabatically, but at higher collision energies non-adiabatic effects have to be taken into account. Reaction probabilities and reaction cross sections for the collision H{sup -} with H{sub 2} and its isotopologues using quasi-classical trajectories and quantum wavepackets were presented in the main part of Chapter 5. It was found that, at low collision energies, the reaction probabilities using SM-PES and AY-PES are very similar. The reaction probabilities based on the PS-PES are lower than those based on the SM-PES and AY-PES. At lower collision energies the reaction cross sections calculated with SM-PES are higher than those calculated with PS-PES. The reaction cross sections investigated with quasi-classical trajectories are higher than those calculated with quantum wavepackets (using the same potential). The last section of Chapter 5 showed results for the collision of H{sup -} and D{sup -} with HD. The total I reaction probabilities, the reaction cross sections, and the product ratios were determined using quasi-classical trajectories. One can learn from these calculations that for the H{sup -} + HD(v=0-1, j=0) reaction and low collision energies, the main product are H{sub 2} + D{sup -}. At high collision energies, the product channel HD + H{sup -} is slightly dominant. For the collision of D{sup -} with HD and low collision energies the product channel HD + D{sup -} is strongly favored, but in the high collision energy range, the product channel D{sub 2} + H{sup -} dominates.

  5. Influence of isotopic disorder on solid state amorphization and polyamorphism in solid H2O -D2O solutions

    Science.gov (United States)

    Gromnitskaya, E. L.; Danilov, I. V.; Lyapin, A. G.; Brazhkin, V. V.

    2015-10-01

    We present a low-temperature and high-pressure ultrasonic study of elastic properties of isotopic H2O-D2O solid solutions, comparing their properties with those of the isotopically pure H2O and D2O ices. Measurements were carried out for solid state amorphization (SSA) from 1h to high-density amorphous (HDA) ice upon compression up to 1.8 GPa at 77 K and for the temperature-induced (77 -190 K ) u-HDA (unrelaxed HDA) → e-HDA (expanded HDA) → low-density amorphous (LDA )→1 c cascade of ice transformations near room pressure. There are many similarities in the elasticity behaviour of H2O ,D2O , and H2O-D2O solid solutions, including the softening of the shear elastic modulus as a precursor of SSA and the HDA →LDA transition. We have found significant isotopic effects during H/D substitution, including elastic softening of H2O -D2O solid solutions with respect to the isotopically pure ices in the case of the bulk moduli of ices 1c and 1h and for both bulk and shear elastic moduli of HDA ice at high pressures (>1 GPa ) . This softening is related to the configurational isotopic disorder in the solid solutions. At low pressures, the isotope concentration dependence of the elastic moduli of u-HDA ice changes remarkably and becomes monotonic with pronounced change of the bulk modulus (≈20 %) .

  6. D/H ratio for Jupiter

    International Nuclear Information System (INIS)

    Smith, H.; Schempp, W.V.; Baines, K.H.

    1989-01-01

    Observations of Jupiter's spectrum near the R5(0) HD line at 6063.88 A are reported. A feature with an equivalent width of 0.065 + or - 0.021 mA is coincident with the expected line. This feature is compared with HD profiles computed for inhomogeneous scattering models for Jupiter to yield a range for the Jovian D/H ratio of 1.0-2.9 x 10 to the -5th. This D/H ratio is in the lower range of previously reported D/H values for Jupiter and corresponds to an essentially solar D/H ratio for Jupiter. The detection of HD features in the presence of probable blends with spectral features of minor atmospheric hydrocarbon molecules is discussed. Such blends may make unambiguous identification of HD features difficult. 26 references

  7. Theoretical/experimental comparison of deep tunneling decay of quasi-bound H(D)OCO to H(D) + CO₂.

    Science.gov (United States)

    Wagner, Albert F; Dawes, Richard; Continetti, Robert E; Guo, Hua

    2014-08-07

    The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO2 on several recent ab initio potential energy surfaces for the HOCO system. The tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. The resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment occurring for the PIP-NN surface based on UCCSD(T)-F12a/AVTZ electronic structure calculations and also a partial surface constructed for this study based on CASPT2/AVDZ electronic structure calculations. These two surfaces differ in barrier height by 1.6 kcal/mol but when matched at the saddle point have an almost identical shape along their reaction paths. The PIP surface is a less accurate fit to a smaller ab initio data set than that used for PIP-NN and its computed survival fractions are somewhat inferior to PIP-NN. The LTSH potential energy surface is the oldest surface examined and is qualitatively incompatible with experiment. This surface also has a small discontinuity that is easily repaired. On each surface, four different approximate tunneling methods are compared but only the small curvature tunneling method and the improved semiclassical transition state method produce useful results on all four surfaces. The results of these two methods are generally comparable and in qualitative agreement with experiment on the PIP-NN and CASPT2 surfaces. The original semiclassical transition state theory method produces qualitatively incorrect tunneling probabilities on all surfaces except the PIP. The Eckart tunneling method uses the least

  8. Insertion and C-H bond activation of unsaturated substrates by bis(benzamidinato)yttrium alkyl, [PhC(NSiMe(3))(2)](2)YR (R=CH(2)Ph center dot THF,CH(SiMe(3))(2)), and hydride, {[PhC(NSiMe(3))(2)]Y-2(mu-H)}(2), compounds

    NARCIS (Netherlands)

    Duchateau, R; vanWee, CT; Teuben, JH

    1996-01-01

    The reactivity of benzamidinate-stabilized yttrium complexes [PhC(NSiMe(3))(2)](2)YR (R = CH(2)Ph . THF, CH(SiMe(3))(2) and {[PhC(NSiMe(3))(2)]Y-2(mu-H)}(2) have been investigated. The complexes are thermally stable showing no sign of decomposition, ligand or solvent metalation or H/D exchange after

  9. Insertion and C-H Bond Activation of Unsaturated Substrates by Bis(benzamidinato)yttrium Alkyl, [PhC(NSiMe3)2]2YR (R = CH2Ph·THF, CH(SiMe3)2), and Hydrido, {[PhC(NSiMe3)2]2Y(μ-H)}2, Compounds

    NARCIS (Netherlands)

    Duchateau, Robbert; Wee, Cornelis T. van; Teuben, Jan H.

    1996-01-01

    The reactivity of benzamidinate-stabilized yttrium complexes [PhC(NSiMe3)2]2YR (R = CH2Ph·THF, CH(SiMe3)2) and {[PhC(NSiMe3)2]2Y(μ-H)}2 has been investigated. The complexes are thermally stable showing no sign of decomposition, ligand or solvent metalation, or H/D exchange after hours at 100 °C in

  10. Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A

    International Nuclear Information System (INIS)

    Fang, Mei-Juan; Zhang, He; Liao, Chao; Qiu, Ying-Kun; Fang, Hua; Zheng, Zhen-Yu; Gao, Xiang; Zhao, Yu-Fen; Wu, Zhen

    2015-01-01

    Highlights: • ESI-MS n , HRMS and H/D exchange were used. • The fragmentation pathways of NPAAE-BFA in ESI-MS n were described. • Fragment ions involved in phosphorus group’s rearrangement reactions were observed. • Two rearrangement mechanisms about phosphorylation–dephosphorylation were proposed. - Abstract: As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a–2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments’s structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a–2d have been summarized and the plausible schemes for the fragmentation pathways were proposed. In this study, one dephosphorylated ion and two phosphorylated ions were observed in ESI-MS 2 spectra of [M + Na] + ions for compounds 2a–2d. The possible mechanisms about phosphorylation and dephosphorylation were proposed and confirmed by H/D exchange. For the “dephosphorylation” rearrangement, a nitrogen atom was migrated from the phosphoryl group to the carbon atom of Brefeldin A’s backbone with losing a molecule of C 3 H 7 PO 3 (122 Da). For the “phosphorylation” rearrangement, an oxygen atom of one phosphoryl group attacked the sideward phosphorus atom to form a nine-member ring intermediate, then two steps of C-H covalent bond cleavage with consecutive migration of hydrogen atom to lose a molecule of C 16 H 20 O 2 (244 Da). The two proposed rearrangement mechanisms about phosphoryl group transfer might be valuable for the structure analysis of other analogs and provide insights into elucidating the dynamic process of the phosphorylation–dephosphorylation of proteins

  11. Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Mei-Juan; Zhang, He; Liao, Chao; Qiu, Ying-Kun [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); Fang, Hua [The Third Institute of Oceanography of the State Oceanic Administration, Xiamen 361005 (China); Zheng, Zhen-Yu [College of Chemistry and Chemical Engineering, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Gao, Xiang [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); Zhao, Yu-Fen [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); College of Chemistry and Chemical Engineering, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Wu, Zhen, E-mail: wuzhen@xmu.edu.cn [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China)

    2015-01-01

    Highlights: • ESI-MS{sup n}, HRMS and H/D exchange were used. • The fragmentation pathways of NPAAE-BFA in ESI-MS{sup n} were described. • Fragment ions involved in phosphorus group’s rearrangement reactions were observed. • Two rearrangement mechanisms about phosphorylation–dephosphorylation were proposed. - Abstract: As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a–2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments’s structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a–2d have been summarized and the plausible schemes for the fragmentation pathways were proposed. In this study, one dephosphorylated ion and two phosphorylated ions were observed in ESI-MS{sup 2} spectra of [M + Na]{sup +} ions for compounds 2a–2d. The possible mechanisms about phosphorylation and dephosphorylation were proposed and confirmed by H/D exchange. For the “dephosphorylation” rearrangement, a nitrogen atom was migrated from the phosphoryl group to the carbon atom of Brefeldin A’s backbone with losing a molecule of C{sub 3}H{sub 7}PO{sub 3} (122 Da). For the “phosphorylation” rearrangement, an oxygen atom of one phosphoryl group attacked the sideward phosphorus atom to form a nine-member ring intermediate, then two steps of C-H covalent bond cleavage with consecutive migration of hydrogen atom to lose a molecule of C{sub 16}H{sub 20}O{sub 2} (244 Da). The two proposed rearrangement mechanisms about phosphoryl group transfer might be valuable for the structure analysis of other analogs and provide insights into elucidating the dynamic process of the phosphorylation–dephosphorylation of proteins.

  12. Isotopic equilibrium constants of the deuterium exchange between HDO and H2S, H2Se and H2Te

    International Nuclear Information System (INIS)

    Marx, D.

    1959-11-01

    We have determined experimentally the equilibrium constant K of each of the following isotope exchanges: SH 2 + OHD ↔ SHD + OH 2 ; SeH 2 + OHD ↔ SeHD + OH 2 ; TeH 2 + OHD ↔ TeHD + OH 2 . In gaseous phase, statistical thermodynamics leads to the expression: K (Z OHD x Z RH 2 )/(Z OH 2 x Z RHD ) x e W/T (R being the elements S, Se or Te). Z, the partition functions, have been calculated and, through our experimental results, the constant W has been determined. Having obtained W, the equilibrium constant K has been calculated for a series of temperatures. (author) [fr

  13. Multiple scattering mechanisms causing interference effects in the differential cross sections of H + D{sub 2} → HD(v′ = 4,  j′) + D at 3.26 eV collision energy

    Energy Technology Data Exchange (ETDEWEB)

    Sneha, Mahima; Gao, Hong; Zare, Richard N., E-mail: zare@stanford.edu, E-mail: aoiz@quim.ucm.es [Department of Chemistry, Stanford University, Stanford, California 94305 (United States); Jambrina, P. G.; Menéndez, M.; Aoiz, F. J., E-mail: zare@stanford.edu, E-mail: aoiz@quim.ucm.es [Departamento de Quimica Fisica I, Facultad de Quimica, Universidad Complutense de Madrid, Madrid 28040 (Spain)

    2016-07-14

    Differential cross sections (DCSs) for the H + D{sub 2} → HD(v′ = 4,  j′) + D reaction at 3.26 eV collision energy have been measured using the photoloc technique, and the results have been compared with those from quantum and quasiclassical scattering calculations. The quantum mechanical DCSs are in good overall agreement with the experimental measurements. In common with previous results at 1.97 eV, clear interference patterns which appear as fingerlike structures have been found at 3.26 eV but in this case for vibrational states as high as v′ = 4. The oscillatory structure is prominent for low rotational states and progressively disappears as j′ increases. A detailed analysis, similar to that carried out at 1.97 eV, shows that the origin of these structures could be traced to interferences between well defined classical mechanisms. In addition, at this energy, we do not observe the anomalous positive j′–θ trend found for the v′ = 4 manifold at lower collision energies, thus reinforcing our explanation that the anomalous distribution for HD(v′ = 4,  j′) at 1.97 eV only takes place for those states associated with low product recoil energies.

  14. Approximate quantum differential cross section for the F + HD → HF + D and DF + H reactions

    International Nuclear Information System (INIS)

    Lee, K.T.; Bowman, J.M.

    1982-01-01

    In a previous paper we proposed a novel way to obtain approximate quantum mechanical differential cross sections. Here, we use this approximate method to study the reactions F + HD(nu = 0) → FH(nu' = 2) + D and F + DH(nu = 0) → DF(nu' = 3) + H. Backward and forward scattering are found for the first reaction and only backward scattering for the second one. These results agree qualitatively with experiment. 1 figure

  15. Applicability of ambient dose equivalent H*(d) in mixed radiation fields - a critical discussion

    International Nuclear Information System (INIS)

    Hajek, M.; Vana, N.

    2004-01-01

    For purposes of routine radiation protection, it is desirable to characterize the potential irradiation of individuals in terms of a single dose equivalent quantity that would exist in a phantom approximating the human body. The phantom of choice is the ICRU sphere made of 30 cm diameter tissue-equivalent plastic with a density of 1 g.cm-3 and a mass composition of 76.2 % O, 11.1 % C, 10.1 % H and 2.6 % N. Ambient dose equivalent, H*(d), was defined in ICRU report 51 as the dose equivalent that would be produced by an expanded and aligned radiation field at a depth d in the ICRU sphere. The recommended reference depths are 10 mm for strongly penetrating radiation and 0.07 mm for weakly penetrating radiation, respectively. As an operational quantity in radiation protection, H*(d) shall serve as a conservative and directly measurable estimate of protection quantities, e.g. effective dose E, which in turn are intended to give an indication of the risk associated with radiation exposure. The situation attains increased complexity in radiation environments being composed of a variety of charged and uncharged particles in a broad energetic spectrum. Radiation fields of similarly complex nature are, for example, encountered onboard aircraft and in space. Dose equivalent was assessed as a function of depth in quasi tissue-equivalent spheres by means of thermoluminescent dosemeters evaluated according to the high-temperature ratio (HTR) method. The presented experiments were performed both onboard aircraft and the Russian space station Mir. As a result of interaction processes within the phantom body, the incident primary spectrum may be significantly modified with increasing depth. For the radiation field at aviation altitudes we found the maximum of dose equivalent in a depth of 60 mm which conflicts with the 10 mm value recommended by ICRU. Contrary, for the space radiation environment the maximum dose equivalent was found at the surface of the sphere. This suggests that

  16. Three-dimensional quantum mechanical studies of D+H2HD+H reactive scattering. II

    International Nuclear Information System (INIS)

    Choi, B.H.; Tang, K.T.

    1975-01-01

    Three-dimensional quantum mechanical calculations are carried out for the reactive scattering of D+H 2 →DH+H on the Yates--Lester potential surface. The differential and total cross sections as well as the S-matrix elements are obtained and are compared with the corresponding results obtained on the Porter--Karplus potential surface. The differential cross sections and the distributions over final angular momentum states are in much better agreement with the experimental measurements than the previous results obtained on the Porter--Karplus surface. However, the calculated threshold energy for the reaction seems too high whereas the threshold on the Porter--Karplus potential seems too low. These dynamic attributes are discussed in terms of the two-body potentials between the atom and the molecule

  17. Probing peptide fragment ion structures by combining sustained off-resonance collision-induced dissociation and gas-phase H/D exchange (SORI-HDX) in Fourier transform ion-cyclotron resonance (FT-ICR) instruments.

    Science.gov (United States)

    Somogyi, Arpád

    2008-12-01

    The usefulness of gas-phase H/D exchange is demonstrated to probe heterogeneous fragment and parent ion populations. Singly and multiply protonated peptides/proteins were fragmented by using sustained off-resonance irradiation collision-induced dissociation (SORI-CID). The fragments and the surviving precursor ions then all undergo H/D exchange in the gas-phase with either D(2)O or CD(3)OD under the same experimental conditions. Usually, 10 to 60 s of reaction time is adequate to monitor characteristic differences in the H/D exchange kinetic rates. These differences are then correlated to isomeric ion structures. The SORI-HDX method can be used to rapidly test fragment ion structures and provides useful insights into peptide fragmentation mechanisms.

  18. The Deuterator: software for the determination of backbone amide deuterium levels from H/D exchange MS data

    Directory of Open Access Journals (Sweden)

    Tsinoremas NF

    2007-05-01

    Full Text Available Abstract Background The combination of mass spectrometry and solution phase amide hydrogen/deuterium exchange (H/D exchange experiments is an effective method for characterizing protein dynamics, and protein-protein or protein-ligand interactions. Despite methodological advancements and improvements in instrumentation and automation, data analysis and display remains a tedious process. The factors that contribute to this bottleneck are the large number of data points produced in a typical experiment, each requiring manual curation and validation, and then calculation of the level of backbone amide exchange. Tools have become available that address some of these issues, but lack sufficient integration, functionality, and accessibility required to address the needs of the H/D exchange community. To date there is no software for the analysis of H/D exchange data that comprehensively addresses these issues. Results We have developed an integrated software system for the automated analysis and representation of H/D exchange data that has been titled "The Deuterator". Novel approaches have been implemented that enable high throughput analysis, automated determination of deuterium incorporation, and deconvolution of overlapping peptides. This has been achieved by using methods involving iterative theoretical envelope fitting, and consideration of peak data within expected m/z ranges. Existing common file formats have been leveraged to allow compatibility with the output from the myriad of MS instrument platforms and peptide sequence database search engines. A web-based interface is used to integrate the components of The Deuterator that are able to analyze and present mass spectral data from instruments with varying resolving powers. The results, if necessary, can then be confirmed, adjusted, re-calculated and saved. Additional tools synchronize the curated calculation parameters with replicate time points, increasing throughput. Saved results can then

  19. Adding a dimension to the infrared spectra of interfaces using heterodyne detected 2D sum-frequency generation (HD 2D SFG) spectroscopy.

    Science.gov (United States)

    Xiong, Wei; Laaser, Jennifer E; Mehlenbacher, Randy D; Zanni, Martin T

    2011-12-27

    In the last ten years, two-dimensional infrared spectroscopy has become an important technique for studying molecular structures and dynamics. We report the implementation of heterodyne detected two-dimensional sum-frequency generation (HD 2D SFG) spectroscopy, which is the analog of 2D infrared (2D IR) spectroscopy, but is selective to noncentrosymmetric systems such as interfaces. We implement the technique using mid-IR pulse shaping, which enables rapid scanning, phase cycling, and automatic phasing. Absorptive spectra are obtained, that have the highest frequency resolution possible, from which we extract the rephasing and nonrephasing signals that are sometimes preferred. Using this technique, we measure the vibrational mode of CO adsorbed on a polycrystalline Pt surface. The 2D spectrum reveals a significant inhomogenous contribution to the spectral line shape, which is quantified by simulations. This observation indicates that the surface conformation and environment of CO molecules is more complicated than the simple "atop" configuration assumed in previous work. Our method can be straightforwardly incorporated into many existing SFG spectrometers. The technique enables one to quantify inhomogeneity, vibrational couplings, spectral diffusion, chemical exchange, and many other properties analogous to 2D IR spectroscopy, but specifically for interfaces.

  20. MARVEL analysis of the rotational-vibrational states of the molecular ions H2D+ and D2H+.

    Science.gov (United States)

    Furtenbacher, Tibor; Szidarovszky, Tamás; Fábri, Csaba; Császár, Attila G

    2013-07-07

    Critically evaluated rotational-vibrational line positions and energy levels, with associated critically reviewed labels and uncertainties, are reported for two deuterated isotopologues of the H3(+) molecular ion: H2D(+) and D2H(+). The procedure MARVEL, standing for Measured Active Rotational-Vibrational Energy Levels, is used to determine the validated levels and lines and their self-consistent uncertainties based on the experimentally available information. The spectral ranges covered for the isotopologues H2D(+) and D2H(+) are 5.2-7105.5 and 23.0-6581.1 cm(-1), respectively. The MARVEL energy levels of the ortho and para forms of the ions are checked against ones determined from accurate variational nuclear motion computations employing the best available adiabatic ab initio potential energy surfaces of these isotopologues. The number of critically evaluated, validated and recommended experimental (levels, lines) are (109, 185) and (104, 136) for H2D(+) and D2H(+), respectively. The lists of assigned MARVEL lines and levels and variational levels obtained for H2D(+) and D2H(+) as part of this study are deposited in the ESI to this paper.

  1. Accurate Quantum Wave Packet Study of the Deep Well D+ + HD Reaction: Product Ro-vibrational State-Resolved Integral and Differential Cross Sections.

    Science.gov (United States)

    He, Haixiang; Zhu, Weimin; Su, Wenli; Dong, Lihui; Li, Bin

    2018-03-08

    The H + + H 2 reaction and its isotopic variants as the simplest triatomic ion-molecule reactive system have been attracting much interests, however there are few studies on the titled reaction at state-to-state level until recent years. In this work, accurate state-to-state quantum dynamics studies of the titled reaction have been carried out by a reactant Jacobi coordinate-based time-dependent wave packet approach on diabatic potential energy surfaces constructed by Kamisaka et al. Product ro-vibrational state-resolved information has been calculated for collision energies up to 0.2 eV with maximal total angular momentum J = 40. The necessity of including all K-component for accounting the Coriolis coupling for the reaction has been illuminated. Competitions between the two product channels, (D + + HD' → D' + + HD and D + + HD' → H + + DD') were investigated. Total integral cross sections suggest that resonances enhance the reactivity of channel D + + HD'→ H + + DD', however, resonances depress the reactivity of the another channel D + + HD' → D' + + HD. The structures of the differential cross sections are complicated and depend strongly on collision energies of the two channels and also on the product rotational states. All of the product ro-vibrational state-resolved differential cross sections for this reaction do not exhibit rigorous backward-forward symmetry which may indicate that the lifetimes of the intermediate resonance complexes should not be that long. The dynamical observables of this deuterated isotopic reaction are quite different from the reaction of H + + H 2H 2 + H + reported previously.

  2. Anomalous H/D isotope effect in hydrogen bonded systems: H-bonded cyclic structures and transfers of protons

    International Nuclear Information System (INIS)

    Marechal, Y.

    1993-01-01

    The systematic H/D substitution is a precious tool to obtain information on the dynamics of H-bonds. It is particularly useful in IR spectroscopy where H-bonds are at the origin of particularly intense and specific bands and where the particularly great value for the m D /m H ratio ensures strongly marked effects. In most H-bonded systems the effects of these substitutions are normal, in the sense that they are at the origin of bands having intensities, centers (of intensity) and widths smaller in D-bonds by a factor close to √2 as compared to H-bonds. In some systems as carboxylic acid dimers, however, anomalous ratios of intensities are found upon such a substitution. Their origin is still obscure. Experimental results suggest that such anomalous ratios have much to do with the cyclic structure of these systems. It leads to stressing an important property of H-bonded cyclic structures which is that they seem necessary for having transfers of protons between molecules through H-bonds in a neutral aqueous medium (p H =7) at room temperature. The mechanism of such transfers of protons is still poorly known, but these transfers are now suspected to play a fundamental role in such widespread reactions as hydrolysis, peptide synthesis, etc... which may make them soon appear as being a crucial basic mechanism for reactivity of aqueous systems, particularly biological systems

  3. Three-dimensional quantum mechanical studies of D+H2HD+H reactive scattering

    International Nuclear Information System (INIS)

    Tang, K.T.; Choi, B.H.

    1975-01-01

    A three-dimensional quantum mechanical study is made on the reactive scattering of D+H 2 → DH+H. The differential and total cross sections as well as the S-matrix elements are obtained from the adiabatic distorted wave model. With the initial molecule H 2 in the ground rotational state, we calculated the cross sections for reactions to all possible rotational states of the product molecule DH. The potential used is that of the Porter and Karplus semiempirical surface. The reactive scattering is predominantly backward. However, the peak in the differential cross sections gradually shifts away from theta=π as the energy is increased, with higher rotational states shifting more. In the thermal energy region, there is virtually no scattering in forward directions. The reaction is endothermic but only slightly so. Although the 0→0 rotational transition contributes only a small fraction to the total reactive cross section, most product molecules prefer rotational states that are considerably lower than the highest one allowed by energy conservation. Differential cross sections summed over all possible final rotational states are significantly different from that of any one state. Previous three-dimensional quantum mechanical studies on this system are all limited to one final rotational state; these previous results are compared with the result of the corresponding case in the present study. The present results are also compared with the corresponding classical trajectory calculations on the same potential surface. Finally, the experimental measurements of Geddes, Kraus, and Fite are compared with the present results. Qualitatively, there are general agreements. but quantitatively the calculated cross sections are definitely too large as compared with the experimental ones. The most likely cause for this difference is that the potential surface used is ''too reactive.''

  4. H-D exchange on natural aluminosilicates of orthosilicate group

    International Nuclear Information System (INIS)

    Markevich, S.V.; Kolesnikov, I.M.

    1982-01-01

    Experimental data are presented on the effect of aluminium ion coordination in the composition of polyhedrons on the capability of polyhedrons to change the reaction rate of H-D exchange (on the example of ethylene). It is shown that at temperature lower 400 deg C the rate of isotopic exchange reaction is low. Experimental results both for irradiated and non-irradiated minerals are presented. The conclusion is made that the increase of aluminosilicates activity under radiation is connected with the presence of (AlO 4 )-tetrahedrons in the system and change of their state. (AlO 5 ) and (AlO 6 )-polyhedrons are not activated with gamma rays

  5. 2H(d,p)3H and 2H(d,n)3He reactions at sub-coulomb energies

    International Nuclear Information System (INIS)

    Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A. M.; Typel, S.; Spartá, R.; Aliotta, M.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Mrazek, J.; Pizzone, R. G.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.

    2012-01-01

    The 2 H( 3 He,p 3 H) 1 H and 2 H( 3 He,n 3 He) 1 H processes have been measured in quasi free kinematics to investigate for the first time the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions by means of the Trojan Horse Method. The 3 He+d experiment was performed at 18 MeV, corresponding the a d-d energy range from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre Main Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the bare nucleus S(E) factors have been extracted for the first time. They deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3 H+p and 60.1±1.9 MeVb for 3 He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  6. Direct observation of forward-scattering oscillations in the H+HD→H2+D reaction

    Science.gov (United States)

    Yuan, Daofu; Yu, Shengrui; Chen, Wentao; Sang, Jiwei; Luo, Chang; Wang, Tao; Xu, Xin; Casavecchia, Piergiorgio; Wang, Xingan; Sun, Zhigang; Zhang, Dong H.; Yang, Xueming

    2018-06-01

    Accurate measurements of product state-resolved angular distributions are central to fundamental studies of chemical reaction dynamics. Yet, fine quantum-mechanical structures in product angular distributions of a reactive scattering process, such as the fast oscillations in the forward-scattering direction, have never been observed experimentally and the nature of these oscillations has not been fully explored. Here we report the crossed-molecular-beam experimental observation of these fast forward-scattering oscillations in the product angular distribution of the benchmark chemical reaction, H + HDH2 + D. Clear oscillatory structures are observed for the H2(v' = 0, j' = 1, 3) product states at a collision energy of 1.35 eV, in excellent agreement with the quantum-mechanical dynamics calculations. Our analysis reveals that the oscillatory forward-scattering components are mainly contributed by the total angular momentum J around 28. The partial waves and impact parameters responsible for the forward scatterings are also determined from these observed oscillations, providing crucial dynamics information on the transient reaction process.

  7. Physisorbed H{sub 2}@Cu(100) surface: Potential and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Eddy; Houriez, Céline; Mitrushchenkov, Alexander O.; Guitou, Marie; Chambaud, Gilberte, E-mail: gilberte.chambaud@univ-mlv.fr [Université Paris-Est, Laboratoire Modélisation et Simulation Multi-Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, Champs sur Marne, F-77454 Marne-la-Vallée (France)

    2015-02-07

    Using an embedding approach, a 2-D potential energy function has been calculated to describe the physisorption interaction of H{sub 2} with a Cu(100) surface. For this purpose, a cluster model of the system calculated with highly correlated wavefunctions is combined with a periodic Density-Functional-Theory method using van der Waals-DF2 functional. Rotational and vibrational energy levels of physisorbed H{sub 2}, as well as D{sub 2} and HD, are calculated using the 2D embedding corrected potential energy function. The calculated transitions are in a very good agreement with Electron-Energy-Loss-Spectroscopy observations.

  8. On the sign of d2H/dt2

    International Nuclear Information System (INIS)

    Dipankar, R.

    1977-11-01

    For a system with a given energy that has N different possible states, the H function (of thermodynamics) satisfies d 2 H/dt 2 >0 if N( 2 H/dt 2 may be both positive and negative if N(>=)5. The case of N=4 remains undetermined

  9. Probing the pre-reactive a Cl (2P) + H2(D2) Van der Waals well through the photodetachment spectroscopy of Cl- H2(D2). CP-31

    International Nuclear Information System (INIS)

    Ghosal, Subhas; Mahapatra, Susanta

    2004-01-01

    The photodetachment spectrum of ClH 2 - and ClD 2 , probing the van der Waals well region of the reactive Cl( 2 P) + H 2 (D 2 ) potential energy surface, is theoretically calculated and compared with the experiment. A time-dependent wave packet approach is employed using the Capecchi-Werner coupled multi-sheeted ab initio potential energy surfaces of neutral ClH 2 for this purpose

  10. Intermolecular potential and rovibrational states of the H2O–D2 complex

    International Nuclear Information System (INIS)

    Avoird, Ad van der; Scribano, Yohann; Faure, Alexandre; Weida, Miles J.; Fair, Joanna R.; Nesbitt, David J.

    2012-01-01

    Graphical abstract: H 2 O–D 2 potential surface and pH 2 O–oD 2 ground state wave function, for planar geometries. Highlights: ► The interaction between H 2 O and H 2 is of great astrophysical interest. ► The rovibrational states of H 2 O–D 2 were computed on an ab initio potential surface. ► Results are compared with the rovibrational states of H 2 O–H 2 computed recently. ► We measured the high-resolution infrared spectrum of H 2 O–D 2 in the H 2 O bend region. ► Comparison with the calculations provides information on H 2 O–H 2 potential surface. - Abstract: A five-dimensional intermolecular potential for H 2 O–D 2 was obtained from the full nine-dimensional ab initio potential surface of Valiron et al. [P. Valiron, M. Wernli, A. Faure, L. Wiesenfeld, C. Rist, S. Kedžuch, J. Noga, J. Chem. Phys. 129 (2008) 134306] by averaging over the ground state vibrational wave functions of H 2 O and D 2 . On this five-dimensional potential with a well depth D e of 232.12 cm −1 we calculated the bound rovibrational levels of H 2 O–D 2 for total angular momentum J = 0–3. The method used to compute the rovibrational levels is similar to a scattering approach—it involves a basis of coupled free rotor wave functions for the hindered internal rotations and the overall rotation of the dimer—while it uses a discrete variable representation of the intermolecular distance coordinate R. The basis was adapted to the permutation symmetry associated with the para/ortho (p/o) nature of both H 2 O and D 2 , as well as to inversion symmetry. As expected, the H 2 O–D 2 dimer is more strongly bound than its H 2 O–H 2 isotopologue [cf. A. van der Avoird, D.J. Nesbitt, J. Chem. Phys. 134 (2011) 044314], with dissociation energies D 0 of 46.10, 50.59, 67.43, and 73.53 cm −1 for pH 2 O–oD 2 , oH 2 O–oD 2 , pH 2 O–pD 2 , and oH 2 O–pD 2 . A rotationally resolved infrared spectrum of H 2 O–D 2 was measured in the frequency region of the H 2 O bend

  11. Isotopic equilibrium constants of the deuterium exchange between HDO and H{sub 2}S, H{sub 2}Se and H{sub 2}Te; Etude des constantes des equilibres isotopiques du deuterium entre l'eau et les hydrures des metalloides de la deuxieme famille

    Energy Technology Data Exchange (ETDEWEB)

    Marx, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-11-15

    We have determined experimentally the equilibrium constant K of each of the following isotope exchanges: SH{sub 2} + OHD {r_reversible} SHD + OH{sub 2}; SeH{sub 2} + OHD {r_reversible} SeHD + OH{sub 2}; TeH{sub 2} + OHD {r_reversible} TeHD + OH{sub 2}. In gaseous phase, statistical thermodynamics leads to the expression: K (Z{sub OHD} x Z{sub RH{sub 2}})/(Z{sub OH{sub 2}} x Z{sub RHD}) x e{sup W/T} (R being the elements S, Se or Te). Z, the partition functions, have been calculated and, through our experimental results, the constant W has been determined. Having obtained W, the equilibrium constant K has been calculated for a series of temperatures. (author) [French] Nous avons determine experimentalement la constante K de chacun des equilibres isotopiques suivants: SH{sub 2} + OHD {r_reversible} SHD + OH{sub 2}; SeH{sub 2} + OHD {r_reversible} SeHD + OH{sub 2}; TeH{sub 2} + OHD {r_reversible} TeHD + OH{sub 2}. En phase gazeuse, la thermodynamique donne l'expression: K = (Z{sub OHD} x Z{sub RH{sub 2}})/(Z{sub OH{sub 2}} x Z{sub RHD}) x e{sup W/T} (R representant un atome de soufre, selenium ou tellure). Les fonctions de partition Z de chacune des molecules ont ete calculees et, grace a nos resultats experimentaux, nous avons determine la constante W. Connaissant W, la constante d'equilibre K a pu etre tabulee en fonction de la temperature. (auteur)

  12. On Secondary Electron Emission from Solid H2 and D2

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.

    1978-01-01

    The emission of secondary electrons from solid hydrogen (H2 , D2, T2) is often considered to be of importance for the interaction between a fusion plasma and pellets of solid hydrogens. A set-up was therefore built for studies of interactions between energetic particles and solid hydrogens. Studies...... of secondary electron emission (SEE) from solid H2 and D2 were made for incidence of electrons up to 3 keV and for incidence of ions of hydrogen, deuterium, and helium up to 10 keV. The measurements were made for normal incidence, and in some cases also for oblique incidence. The SEE coefficients for solid H2...... is always 0.65-0.70 times that for solid D2. This difference is attributed to different losses to vibrational states in H2 and D2 for the low energy electrons. Measurements were also made on solid para-H2 with both electrons and hydrogen ions. There was no difference from the results for normal H2, which...

  13. Differential cross sections for transfer into the 2S state of hydrogen: H+ + H2, H+ + D2

    International Nuclear Information System (INIS)

    Williams, D.G.; Lee, A.R.; Butcher, E.C.

    1986-01-01

    Differential cross sections for electron capture into the 2S state of hydrogen are presented for the reactions H + + H 2 and H + + D 2 . The results are for laboratory collision energies between 3.3 and 24 keV and scattering angles between 30 and 90'. The measurements expand on the results previously presented. (author)

  14. Ab initio study of {sup 2}H(d,{gamma}){sup 4}He, {sup 2}H(d,p){sup 3}H, and {sup 2}H(d,n){sup 4}He reactions and the tensor force

    Energy Technology Data Exchange (ETDEWEB)

    Arai, K.; Aoyama, S.; Suzuki, Y.; Descouvemont, P.; Baye, D. [Division of General Education, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, Niigata, 940-8532 (Japan); Center for Academic Information Service, Niigata University, Niigata 950-2181 (Japan); Department of Physics, Niigata University, Niigata 950-2181, Japan and RIKEN Nishina Center, Wako 351-0198 (Japan); Physique Nucleaire Theorique et Physique Mathematique, C.P.229, Universite Libre de Bruxelles, B 1050 Brussels (Belgium); Physique Quantique, CP165/82, Universite Libre de Bruxelles, B-1050 Brussels (Belgium)

    2012-11-12

    The {sup 2}H(d,p){sup 3}H, {sup 2}H(d,n){sup 3}He, and {sup 2}H(d,{gamma}){sup 4}He reactions at low energies are studied with realistic nucleon-nucleon interactions in an ab initio approach. The obtained astrophysical S-factors are all in very good agreement with experiment. The most important channels for both transfer and radiative capture are all found to dominate thanks to the tensor force.

  15. Non-invasive acoustic-based monitoring of uranium in solution and H/D ratio

    Energy Technology Data Exchange (ETDEWEB)

    Pantea, Cristian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beedle, Christopher Craig [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinha, Dipen N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lakis, Rollin Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-01

    The primary objective of this project is to adapt existing non-invasive acoustic techniques (Swept-Frequency Acoustic Interferometry and Gaussian-pulse acoustic technique) for the purpose of demonstrating the ability to quantify U or H/D ratios in solution. Furthermore, a successful demonstration will provide an easily implemented, low cost, and non-invasive method for remote and unattended uranium mass measurements for International Atomic Energy Agency (IAEA).

  16. The H+3 + H2 isotopic system. Origin of deuterium astrochemistry

    International Nuclear Information System (INIS)

    Hugo, Edouard Jean-Marie

    2008-01-01

    Dense cold molecular clouds reckoned to be stellar nurseries are the scene of an extreme molecular deuteration. Despite the cosmic D/H ratio of ∝10 -5 , molecular species in prestellar cores are observed to contain nearly as much deuterium as hydrogen. This astonishing deuterium enrichment promoted by low temperatures is the work of H + 3 . It is the key species which unlocks the deuterium from its HD reservoir via reactions like H + 3 +HDH 2 D + +H 2 and drags it further to other species in successive reactions. For this reason, the H + 3 +H 2 isotopic system is outstandingly critical for the astrochemistry of cold environments. However, its understanding is yet incomplete and insufficient. This thesis thus focuses on the H + 3 +H 2 isotopic system from a theoretical, experimental and astronomical point of view giving a particular look into the role of nuclear spins. As a first step, the stringent nuclear spin selection rules in associative, dissociative and reactive collisions are investigated. This purely theoretical study zooms into the details of the nuclear spin wavefunctions and shows that their permutation symmetry representation is necessary and sufficient, contrary to their angular momentum representation. Additionally, a new deterministic interpretation of nuclear spins in chemical reactions is proposed. Based on these considerations, a complete set of state-to-state rate coefficients for all H + 3 + H 2 isotopic variants is calculated using a microcanonical model leaned on phase space theory. An experimental study is conducted in parallel with a 22-pole ion trap apparatus in order to inspect the influences of temperature and H 2 ortho-to-para ratio. The good overall agreement between experimental and theoretical results supports the validity and utility of the calculated set of rate coefficients. Furthermore, the potentiality of the 22-pole ion trap apparatus is explored via the Laser Induced Reaction (LIR) technique applied to our system of

  17. The vibration-rotation-tunneling levels of N2-H2O and N2-D2O

    Science.gov (United States)

    Wang, Xiao-Gang; Carrington, Tucker

    2015-07-01

    In this paper, we report vibration-rotation-tunneling levels of the van der Waals clusters N2-H2O and N2-D2O computed from an ab initio potential energy surface. The only dynamical approximation is that the monomers are rigid. We use a symmetry adapted Lanczos algorithm and an uncoupled product basis set. The pattern of the cluster's levels is complicated by splittings caused by H-H exchange tunneling (larger splitting) and N-N exchange tunneling (smaller splitting). An interesting result that emerges from our calculation is that whereas in N2-H2O, the symmetric H-H tunnelling state is below the anti-symmetric H-H tunnelling state for both K = 0 and K = 1, the order is reversed in N2-D2O for K = 1. The only experimental splitting measurements are the D-D exchange tunneling splittings reported by Zhu et al. [J. Chem. Phys. 139, 214309 (2013)] for N2-D2O in the v2 = 1 region of D2O. Due to the inverted order of the split levels, they measure the sum of the K = 0 and K = 1 tunneling splittings, which is in excellent agreement with our calculated result. Other splittings we predict, in particular those of N2-H2O, may guide future experiments.

  18. Physical limit of stability in supercooled D2O and D2O+H2O mixtures

    Science.gov (United States)

    Kiselev, S. B.; Ely, J. F.

    2003-01-01

    The fluctuation theory of homogeneous nucleation was applied for calculating the physical boundary of metastable states, the kinetic spinodal, in supercooled D2O and D2O+H2O mixtures. The kinetic spinodal in our approach is completely determined by the surface tension and equation of state of the supercooled liquid. We developed a crossover equation of state for supercooled D2O, which predicts a second critical point of low density water-high density water equilibrium, CP2, and represents all available experimental data in supercooled D2O within experimental accuracy. Using Turnbull's expression for the surface tension we calculated with the crossover equation of state for supercooled D2O the kinetic spinodal, TKS, which lies below the homogeneous nucleation temperature, TH. We show that CP2 always lies inside in the so-called "nonthermodynamic habitat" and physically does not exist. However, the concept of a second "virtual" critical point is physical and very useful. Using this concept we have extended this approach to supercooled D2O+H2O mixtures. As an example, we consider here an equimolar D2O+H2O mixture in normal and supercooled states at atmospheric pressure, P=0.1 MPa.

  19. Report on Non-invasive acoustic monitoring of D2O concentration Oct 31 2017

    Energy Technology Data Exchange (ETDEWEB)

    Pantea, Cristian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinha, Dipen N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lakis, Rollin Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beedle, Christopher Craig [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Davis, Eric Sean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-06

    There is an urgent need for real-time monitoring of the hydrogen /deuterium ratio (H/D) for heavy water production monitoring. Based upon published literature, sound speed is sensitive to the deuterium content of heavy water and can be measured using existing acoustic methods to determine the deuterium concentration in heavy water solutions. We plan to adapt existing non-invasive acoustic techniques (Swept-Frequency Acoustic Interferometry and Gaussian-pulse acoustic technique) for the purpose of quantifying H/D ratios in solution. A successful demonstration will provide an easily implemented, low cost, and non-invasive method for remote and unattended H/D ratio measurements with a resolution of less than 0.2% vol.

  20. Thermally activated 3D to 2D structural transformation of [Ni2(en)2(H2O)6(pyr)]·4H2O flexible coordination polymer

    International Nuclear Information System (INIS)

    Begović, Nebojša N.; Blagojević, Vladimir A.; Ostojić, Sanja B.; Radulović, Aleksandra M.; Poleti, Dejan; Minić, Dragica M.

    2015-01-01

    Thermally activated 3D to 2D structural transformation of the binuclear [Ni 2 (en) 2 (H 2 O) 6 (pyr)]·4H 2 O complex was investigated using a combination of theoretical and experimental methods. Step-wise thermal degradation (dehydration followed by release of ethylene diamine) results in two layered flexible coordination polymer structures. Dehydration process around 365 K results in a conjugated 2D structure with weak interlayer connectivity. It was shown to be a reversible 3D to 2D framework transformation by a guest molecule, and rehydration of the dehydration product occurs at room temperature in saturated water vapor. Rehydrated complex exhibits lower dehydration temperature, due to decreased average crystalline size, with higher surface area resulting in easier release and diffusion of water during dehydration. Thermal degradation of dehydration around 570 K, results in loss of ethylene diamine, producing a related 2D layered polymer structure, without interconnectivity between individual polymer layers. - Highlights: • Reversible 3D to 2D framework topochemical transformation on dehydration around 365 K. • Resulting polymer exhibits 2D layered structure with weak interlayer connectivity. • Dehydration is fully reversible in saturated water vapor at room temperature. • Further degradation around 570 K yields 2D polymer without interlayer connectivity. • 2D polymer exhibits conjugated electronic system

  1. Theoretical Study of H/D Isotope Effects on Nuclear Magnetic Shieldings Using an ab initio Multi-Component Molecular Orbital Method

    Directory of Open Access Journals (Sweden)

    Masanori Tachikawa

    2013-05-01

    Full Text Available We have theoretically analyzed the nuclear quantum effect on the nuclear magnetic shieldings for the intramolecular hydrogen-bonded systems of σ-hydroxy acyl aromatic species using the gauge-including atomic orbital technique combined with our multi-component density functional theory. The effect of H/D quantum nature for geometry and nuclear magnetic shielding changes are analyzed. Our study clearly demonstrated that the geometrical changes of hydrogen-bonds induced by H/D isotope effect (called geometrical isotope effect: GIE is the dominant factor of deuterium isotope effect on 13C chemical shift.

  2. Novel 2D or 3D alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand

    Science.gov (United States)

    Du, Zi-Yi; Wen, He-Rui; Xie, Yong-Rong

    2008-11-01

    Three novel alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand, namely, [Ca(O 3SC 2H 4PO 3H)(H 2O) 2] ( 1), [Sr(O 3SC 2H 4PO 3H)] ( 2) and [Ba 2(O 3SC 2H 4PO 3H) 2] ( 3), have been synthesized by hydrothermal reactions. They represent the first structurally characterized alkaline-earth metal complexes of phosphonic acid attached with a sulfonate group. The structure of compound 1 features a 2D layer based on 1D chains of [Ca 2(PO 3) 2] bridged by -CH 2-CH 2-SO 3- groups. Compounds 2 and 3 show pillar-layer architecture based on two different inorganic layers linked by -CH 2-CH 2- groups. The inorganic layer in compound 2 features a 1D chain of edge-sharing SrO 8 polyhedra whereas that in compound 3 features an edge-sharing Ba 2O 14 di-polyhedral unit which is further corner-shared with four neighboring ones. The [O 3S-C 2H 4-PO 3H] 2- ligand shows diverse coordination modes in the three alkaline-earth metal sulfonate-phosphonates.

  3. Evaluation of the efficiency of Pd/H2 -catalyzed benzylic H/D exchange of dehydroabietinal with D(2) O and synthesis of a tritium-labeled analogue.

    Science.gov (United States)

    Petros, Robby A; Shah, Jyoti

    2014-01-01

    Dehydroabietinal (DA) has been identified as an important signaling molecule in systemic acquired resistance in plants. Deuterium and tritium-labeled DA were synthesized to confirm its role in signaling and to further elucidate the mechanism by which DA induces systemic acquired resistance. Pd/H2 -catalyzed exchange of benzylic hydrogen atoms of DA with (2) H-H2 O or (3) H-H2 O was conducted with >97% label incorporation for (2) H-DA and a specific activity of 12.6 mCi/mmol for (3) H-DA synthesized from 90 mCi/mmol (3) H-H2 O. The extent of deuterium labeling at each benzylic position was determined via an inverse-gated (13) C NMR experiment. C7 and C15 were 87% and 81% labeled, respectively. Isotope-induced chemical shift changes at C6 were used to approximate the amount of singly (66%) and doubly (17%) labeled (2) H-DA at C7. Results also indicated that two of the three benzylic protons in DA underwent facile exchange. Exchange at the remaining position was likely hampered by steric interactions of nearby methyl groups at the surface of the Pd catalyst. Copyright © 2013 John Wiley & Sons, Ltd.

  4. A Cadmium Anionic 1-D Coordination Polymer {[Cd(H2O6][Cd2(atr22-btc2(H2O4] 2H2O}n within a 3-D Supramolecular Charge-Assisted Hydrogen-Bonded and π-Stacking Network

    Directory of Open Access Journals (Sweden)

    Anas Tahli

    2016-03-01

    Full Text Available The hydrothermal reaction of 4,4′-bis(1,2,4-triazol-4-yl (btr and benzene-1,3,5-tricarboxylic acid (H3btc with Cd(OAc2·2H2O at 125 °C in situ forms 4-amino-1,2,4-triazole (atr from btr, which crystallizes to a mixed-ligand, poly-anionic chain of [Cd2(atr22-btc2(H2O4]2–. Together with a hexaaquacadmium(II cation and water molecules the anionic coordination-polymeric forms a 3-D supramolecular network of hexaaquacadmium(II-catena-[bis(4-amino-1,2,4-triazoletetraaquabis(benzene-1,3,5-tricarboxylatodicadmate(II] dihydrate, 1-D-{[Cd(H2O6][Cd2(atr22-btc2(H2O4] 2H2O}n which is based on hydrogen bonds (in part charge-assisted and π–π interactions.

  5. Comparative evaluation of HD 2D/3D laparoscopic monitors and benchmarking to a theoretically ideal 3D pseudodisplay: even well-experienced laparoscopists perform better with 3D.

    Science.gov (United States)

    Wilhelm, D; Reiser, S; Kohn, N; Witte, M; Leiner, U; Mühlbach, L; Ruschin, D; Reiner, W; Feussner, H

    2014-08-01

    Though theoretically superior to standard 2D visualization, 3D video systems have not yet achieved a breakthrough in laparoscopy. The latest 3D monitors, including autostereoscopic displays and high-definition (HD) resolution, are designed to overcome the existing limitations. We performed a randomized study on 48 individuals with different experience levels in laparoscopy. Three different 3D displays (glasses-based 3D monitor, autostereoscopic display, and a mirror-based theoretically ideal 3D display) were compared to a 2D HD display by assessing multiple performance and mental workload parameters and rating the subjects during a laparoscopic suturing task. Electromagnetic tracking provided information on the instruments' pathlength, movement velocity, and economy. The usability, the perception of visual discomfort, and the quality of image transmission of each monitor were subjectively rated. Almost all performance parameters were superior with the conventional glasses-based 3D display compared to the 2D display and the autostereoscopic display, but were often significantly exceeded by the mirror-based 3D display. Subjects performed a task faster and with greater precision when visualization was achieved with the 3D and the mirror-based display. Instrument pathlength was shortened by improved depth perception. Workload parameters (NASA TLX) did not show significant differences. Test persons complained of impaired vision while using the autostereoscopic monitor. The 3D and 2D displays were rated user-friendly and applicable in daily work. Experienced and inexperienced laparoscopists profited equally from using a 3D display, with an improvement in task performance about 20%. Novel 3D displays improve laparoscopic interventions as a result of faster performance and higher precision without causing a higher mental workload. Therefore, they have the potential to significantly impact the further development of minimally invasive surgery. However, as shown by the

  6. Theoretical study on separation of H2/HD by multi-column interlinking cryogenic distillation

    International Nuclear Information System (INIS)

    Xia Xiulong

    2010-01-01

    Multi-column interlinking is an effective separation method adopted for enrichment of trace deuterium and tritium. Conceptual design and proper operating mode were proposed for separation of H2/HD by cryogenic distillation with three interlinking columns,and separation performance were obtained.Enrichment of 20 x 10 x 10 achieved with proper operating mode indicating multi-column interlinking is specially suitable for trace composition enrichment. Pressure and reflux ratio' effect on separation performance were also investigated. As pressure increased from 0.6 atm to 1.5 atm, deuterium stripping efficiency dropped from 99.79% to 99.44%; As reflux ratio increased from 3 to 5, deuterium stripping efficiency increased from 99.67% to 99.81%. (authors)

  7. Charge transfer processes in collisions of H+ ions with H2, D2, CO, CO2 CH4, C2H2, C2H6 and C3H8 molecules below 10 keV

    International Nuclear Information System (INIS)

    Kusakabe, T.; Buenker, R.J.; Kimura, M.

    2002-01-01

    Charge transfer processes resulting from collisions of H + ions with H 2 , D 2 , CO, CO 2 CH 4 , C 2 H 2 , C 2 H 6 and C 3 H 8 molecules have been investigated in the energy range of 0.2 to 4.0 keV experimentally and theoretically. The initial growth rate method was employed in the experiment for studying the dynamics and cross sections. Theoretical analysis based on a molecular-orbital expansion method for H 2 , D 2 , CO, CH 4 and C 2 H 2 targets was also carried out. The present results for the H 2 , CO and CO 2 molecules by H + impact are found to be in excellent accord with most of previous measurements above 1 keV, but they show some differences below this energy where our result displays a stronger energy-dependence. For CH 4 , C 2 H 2 , C 2 H 6 and C 3 H 8 targets, both experimental and theoretical results indicate that if one assumes vibrationally excited molecular ions (CH 4 + , C 2 H 2 + , C 2 H 6 + and C 3 H 8 + ) formed in the exit channel, then charge transfer processes sometimes become more favorable since these vibrationally excited fragments meet an accidental resonant condition. This is a clear indication of the role of vibrational excited states for charge transfer, and is an important realization for general understanding. (author)

  8. Probing the Gaseous Structure of a β-Hairpin Peptide with H/D Exchange and Electron Capture Dissociation.

    Science.gov (United States)

    Straus, Rita N; Jockusch, Rebecca A

    2017-02-01

    An improved understanding of the extent to which native protein structure is retained upon transfer to the gas phase promises to enhance biological mass spectrometry, potentially streamlining workflows and providing fundamental insights into hydration effects. Here, we investigate the gaseous conformation of a model β-hairpin peptide using gas-phase hydrogen-deuterium (H/D) exchange with subsequent electron capture dissociation (ECD). Global gas-phase H/D exchange levels, and residue-specific exchange levels derived from ECD data, are compared among the wild type 16-residue peptide GB1p and several variants. High protection from H/D exchange observed for GB1p, but not for a truncated version, is consistent with the retention of secondary structure of GB1p in the gas phase or its refolding into some other compact structure. Four alanine mutants that destabilize the hairpin in solution show levels of protection similar to that of GB1p, suggesting collapse or (re)folding of these peptides upon transfer to the gas phase. These results offer a starting point from which to understand how a key secondary structural element, the β-hairpin, is affected by transfer to the gas phase. This work also demonstrates the utility of a much-needed addition to the tool set that is currently available for the investigation of the gaseous conformation of biomolecules, which can be employed in the future to better characterize gaseous proteins and protein complexes. Graphical Abstract ᅟ.

  9. Electronic structure tautomerism, and mechanism of H-D exchange in imidazole aqueous solutions

    International Nuclear Information System (INIS)

    Borisov, Yu.A.; Vorob'eva, N.P.; Abronin, I.A.; Kolomiets, A.F.

    1988-01-01

    The imidazole electronic structure in a gaseous phase is studied taking into account the influence of solvation effects in aqueous solutions. Possible mechanisms of tautomeric transformations and H-D exchange reactions with water molecules are discussed. Using the quantum chemistry methods, it is shown that the intramolecular mechanism of imidazole isomerization in the gaseous phase and the aqueous solution is unprofitable, and the intermolecular mechanism can proceed through the stage of protonated and carbene form formation

  10. Separation of H-D mixtures by cryogenic distillation

    International Nuclear Information System (INIS)

    Luo Yangming; Gu Mei; Wang Heyi; Liu Jun; Fu Zhonghua; Xia Xiulong; Liu Yunnu; Weng Kuiping; Xie Bo; Ren Xingbi

    2007-01-01

    In this paper, separation of hydrogen-deuterium mixtures were performed on a cryogenic distillation apparatus. The results show that the D/H ratio in the reboiler reduced to 1.27x10 -2 at 120h with a flow flux of 5mol/h of the gas mixture in D/H ratio of 1.4xl0 -4 . The enrichment effect increased apparently with D/H ratio of the feeding gas. However, the deuterium content in the top of distillation column increased with the deuterium content in the reboiler, and the de-deuterium efficiencies decreased. In the full reflux experiment, the de-deuterium efficiency increased with heating power of the reboiler, and the inside pressure in the distillation column increased, too. It was necessary that suitable heating power should be chosen in order to control operation pressure in the cryogenic distillation process. (authors)

  11. {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions at sub-coulomb energies

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A. M.; Typel, S.; Sparta, R.; Aliotta, M.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Mrazek, J.; Pizzone, R. G.; Rapisarda, G. G.; Romano, S.; Sergi, M. L. [Universita degli Studi di Enna Kore, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Cyclotron Institute Texas A and M University - College Station, Texas (United States); Excellence Cluster Universe - Technische Universitaet Muenchen, Garching, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH - Theorie Darmstadt (Germany); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); School of Physics and Astronomy - University of Edinburgh, SUPA (United Kingdom); Nuclear Physics Institute of ASCR - Rez near Prague (Czech Republic); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Nuclear Physics Institute of ASCR - Rez near Prague (Czech Republic); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy)

    2012-11-20

    The {sup 2}H({sup 3}He,p{sup 3}H){sup 1}H and {sup 2}H({sup 3}He,n{sup 3}He){sup 1}H processes have been measured in quasi free kinematics to investigate for the first time the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions by means of the Trojan Horse Method. The {sup 3}He+d experiment was performed at 18 MeV, corresponding the a d-d energy range from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre Main Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the bare nucleus S(E) factors have been extracted for the first time. They deviate by more than 15% from available direct data with new S(0) values of 57.4{+-}1.8 MeVb for {sup 3}H+p and 60.1{+-}1.9 MeVb for {sup 3}He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  12. Structure of solid H2-D2 mixtures

    International Nuclear Information System (INIS)

    Krupskij, I.N.; Kovalenko, S.I.; Krajnyukova, N.V.

    1978-01-01

    The structure of vapor deposited H 2 -D 2 solid mixtures is investigated. The electron-diffraction examination has been carried out in the temperature range from 2.3K up to the sample sublimation temperature, taking place in case of H 2 at T approximately 5K and D 2 -at T approximately 7K. On the basis of the difractogramm obtained it is shown that in solid films of pure components a FCC structure with parameters asub(Hsub(2))=5.310+-0.01A and asub(Osub(2))=5.100+-0.005A is realized, the structure being metastable in the temperature range. The existence of non-limitted solubility in solid two-component condensates is stated. The decay absence at T approximately 5K, when molecula mobility is enough for the transition of metastable FCC structure into HCP, is in good agreement with the results of experimental and theoretical estimations, according to which the decay critical temperature should not exceed 4K. The existance of the continuous series of solutions at lower temperatures is explained by a small coefficient value of a volumetric and surface diffusion of molecula as well

  13. Intermolecular potential and rovibrational states of the H{sub 2}O-D{sub 2} complex

    Energy Technology Data Exchange (ETDEWEB)

    Avoird, Ad van der, E-mail: A.vanderAvoird@theochem.ru.nl [Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Scribano, Yohann [Laboratoire Interdisciplinaire Carnot de Bourgogne-UMR 5209, CNRS-Universite de Bourgogne, 9 Av. Alain Savary, B.P. 47870, F-21078 Dijon Cedex (France); Faure, Alexandre [UJF-Grenoble 1/CNRS, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble F-38041 (France); Weida, Miles J. [Daylight Solutions, 15378 Avenue of Science, San Diego, CA 92128 (United States); Fair, Joanna R. [Department of Radiology, MSC10 5530, 1 University of New Mexico, Albuquerque, NM 87131-0001 (United States); Nesbitt, David J. [JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0440 (United States)

    2012-05-03

    Graphical abstract: H{sub 2}O-D{sub 2} potential surface and pH{sub 2}O-oD{sub 2} ground state wave function, for planar geometries. Highlights: Black-Right-Pointing-Pointer The interaction between H{sub 2}O and H{sub 2} is of great astrophysical interest. Black-Right-Pointing-Pointer The rovibrational states of H{sub 2}O-D{sub 2} were computed on an ab initio potential surface. Black-Right-Pointing-Pointer Results are compared with the rovibrational states of H{sub 2}O-H{sub 2} computed recently. Black-Right-Pointing-Pointer We measured the high-resolution infrared spectrum of H{sub 2}O-D{sub 2} in the H{sub 2}O bend region. Black-Right-Pointing-Pointer Comparison with the calculations provides information on H{sub 2}O-H{sub 2} potential surface. - Abstract: A five-dimensional intermolecular potential for H{sub 2}O-D{sub 2} was obtained from the full nine-dimensional ab initio potential surface of Valiron et al. [P. Valiron, M. Wernli, A. Faure, L. Wiesenfeld, C. Rist, S. Kedzuch, J. Noga, J. Chem. Phys. 129 (2008) 134306] by averaging over the ground state vibrational wave functions of H{sub 2}O and D{sub 2}. On this five-dimensional potential with a well depth D{sub e} of 232.12 cm{sup -1} we calculated the bound rovibrational levels of H{sub 2}O-D{sub 2} for total angular momentum J = 0-3. The method used to compute the rovibrational levels is similar to a scattering approach-it involves a basis of coupled free rotor wave functions for the hindered internal rotations and the overall rotation of the dimer-while it uses a discrete variable representation of the intermolecular distance coordinate R. The basis was adapted to the permutation symmetry associated with the para/ortho (p/o) nature of both H{sub 2}O and D{sub 2}, as well as to inversion symmetry. As expected, the H{sub 2}O-D{sub 2} dimer is more strongly bound than its H{sub 2}O-H{sub 2} isotopologue [cf. A. van der Avoird, D.J. Nesbitt, J. Chem. Phys. 134 (2011) 044314], with dissociation energies D

  14. Can two-photon spectroscopy of H{sub 2}{sup +} or HD{sup +} allow a new determination of m{sub p}/m{sub e} ratio?; La spectroscopie a deux photons de H{sub 2}{sup +} ou HD{sup +} peut-elle permettre une nouvelle determination de m{sub p}/m{sub e}?

    Energy Technology Data Exchange (ETDEWEB)

    Karr, J.Ph.; Kilic, S.; Hilico, L. [Universite Pierre et Marie Curie, Lab. Kastler Brossel, 75 - Paris (France); Evry Val d' Essonne Univ., Dept. de Physique, 91 (France)

    2006-10-15

    We present an exact calculation of the non-relativistic energies and wavefunctions of the J=1 states of the HD{sup +} molecular ion. The energies are obtained with a high accuracy of 10{sup -14} u.a, that is an improvement of several orders of magnitude with respects to previous calculations. Then we compute the 2-photon transition probabilities between J=0 states. Finally we extend our study to transitions between higher J states by using the Born-Oppenheimer approximate expression of the transition probability. The HD{sup +} molecular ion appears to be a better candidate than H{sub 2}{sup +} for a 2-photon spectroscopy experiment aimed at determining the m{sub p}/m{sub e} ratio because of the existence of an exceptionally intense 2-photon transition: J=1, v=0 {yields} J=1, v= 2 at 5.369 {mu}m. Furthermore 2 experimental factors support this choice, first the initial level of the transition will be 10 times as populated as in the case of H{sub 2}{sup +}. Secondly, laser sources in the range 5-6 {mu}m are more powerful than those in the range 9-10 {mu}m required for H{sub 2}{sup +}.

  15. Detection of HD in the atmospheres of Uranus and Neptune : a new determination of the D/H ratio

    NARCIS (Netherlands)

    Feuchtgruber, H; Lellouch, E; Bezard, B; Encrenaz, T; de Graauw, T.; Davis, GR

    Observations with the Short Wavelength Spectrometer (SWS) onboard the Infrared Space Observatory (ISO) have led to the first unambiguous detection of HD in the atmospheres of Uranus and Neptune, from its R(2) rotational line at 37.7 mu m Using S(0) and S(1) quadrupolar lines of H(2) at 28.2 and 17.0

  16. Double C-H activation of ethane by metal-free SO2*+ radical cations.

    Science.gov (United States)

    de Petris, Giulia; Cartoni, Antonella; Troiani, Anna; Barone, Vincenzo; Cimino, Paola; Angelini, Giancarlo; Ursini, Ornella

    2010-06-01

    The room-temperature C-H activation of ethane by metal-free SO(2)(*+) radical cations has been investigated under different pressure regimes by mass spectrometric techniques. The major reaction channel is the conversion of ethane to ethylene accompanied by the formation of H(2)SO(2)(*+), the radical cation of sulfoxylic acid. The mechanism of the double C-H activation, in the absence of the single activation product HSO(2)(+), is elucidated by kinetic studies and quantum chemical calculations. Under near single-collision conditions the reaction occurs with rate constant k=1.0 x 10(-9) (+/-30%) cm(3) s(-1) molecule(-1), efficiency=90%, kinetic isotope effect k(H)/k(D)=1.1, and partial H/D scrambling. The theoretical analysis shows that the interaction of SO(2)(*+) with ethane through an oxygen atom directly leads to the C-H activation intermediate. The interaction through sulfur leads to an encounter complex that rapidly converts to the same intermediate. The double C-H activation occurs by a reaction path that lies below the reactants and involves intermediates separated by very low energy barriers, which include a complex of the ethyl cation suitable to undergo H/D scrambling. Key issues in the observed reactivity are electron-transfer processes, in which a crucial role is played by geometrical constraints. The work shows how mechanistic details disclosed by the reactions of metal-free electrophiles may contribute to the current understanding of the C-H activation of ethane.

  17. Stability of globular proteins in H2O and D2O

    NARCIS (Netherlands)

    Efimova, Y. M.; Haemers, S.; Wierczinski, B.; Norde, W.; van Well, A. A.

    2007-01-01

    In several experimental techniques D2O rather then H2O is often used as a solvent for proteins. Concerning the influence of the solvent on the stability of the proteins, contradicting results have been reported in literature. In this paper the influence of H2O-D2O solvent substitution on the

  18. A Novel Aldo-Keto Reductase, HdRed, from the Pacific Abalone Haliotis discus hannai, Which Reduces Alginate-derived 4-Deoxy-L-erythro-5-hexoseulose Uronic Acid to 2-Keto-3-deoxy-D-gluconate.

    Science.gov (United States)

    Mochizuki, Shogo; Nishiyama, Ryuji; Inoue, Akira; Ojima, Takao

    2015-12-25

    Abalone feeds on brown seaweeds and digests seaweeds' alginate with alginate lyases (EC 4.2.2.3). However, it has been unclear whether the end product of alginate lyases (i.e. unsaturated monouronate-derived 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEH)) is assimilated by abalone itself, because DEH cannot be metabolized via the Embden-Meyerhof pathway of animals. Under these circumstances, we recently noticed the occurrence of an NADPH-dependent reductase, which reduced DEH to 2-keto-3-deoxy-D-gluconate, in hepatopancreas extract of the pacific abalone Haliotis discus hannai. In the present study, we characterized this enzyme to some extent. The DEH reductase, named HdRed in the present study, could be purified from the acetone-dried powder of hepatopancreas by ammonium sulfate fractionation followed by conventional column chromatographies. HdRed showed a single band of ∼ 40 kDa on SDS-PAGE and reduced DEH to 2-keto-3-deoxy-D-gluconate with an optimal temperature and pH at around 50 °C and 7.0, respectively. HdRed exhibited no appreciable activity toward 28 authentic compounds, including aldehyde, aldose, ketose, α-keto-acid, uronic acid, deoxy sugar, sugar alcohol, carboxylic acid, ketone, and ester. The amino acid sequence of 371 residues of HdRed deduced from the cDNA showed 18-60% identities to those of aldo-keto reductase (AKR) superfamily enzymes, such as human aldose reductase, halophilic bacterium reductase, and sea hare norsolorinic acid (a polyketide derivative) reductase-like protein. Catalytic residues and cofactor binding residues known in AKR superfamily enzymes were fairly well conserved in HdRed. Phylogenetic analysis for HdRed and AKR superfamily enzymes indicated that HdRed is an AKR belonging to a novel family. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. A Novel Aldo-Keto Reductase, HdRed, from the Pacific Abalone Haliotis discus hannai, Which Reduces Alginate-derived 4-Deoxy-l-erythro-5-hexoseulose Uronic Acid to 2-Keto-3-deoxy-d-gluconate*

    Science.gov (United States)

    Mochizuki, Shogo; Nishiyama, Ryuji; Inoue, Akira; Ojima, Takao

    2015-01-01

    Abalone feeds on brown seaweeds and digests seaweeds' alginate with alginate lyases (EC 4.2.2.3). However, it has been unclear whether the end product of alginate lyases (i.e. unsaturated monouronate-derived 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH)) is assimilated by abalone itself, because DEH cannot be metabolized via the Embden-Meyerhof pathway of animals. Under these circumstances, we recently noticed the occurrence of an NADPH-dependent reductase, which reduced DEH to 2-keto-3-deoxy-d-gluconate, in hepatopancreas extract of the pacific abalone Haliotis discus hannai. In the present study, we characterized this enzyme to some extent. The DEH reductase, named HdRed in the present study, could be purified from the acetone-dried powder of hepatopancreas by ammonium sulfate fractionation followed by conventional column chromatographies. HdRed showed a single band of ∼40 kDa on SDS-PAGE and reduced DEH to 2-keto-3-deoxy-d-gluconate with an optimal temperature and pH at around 50 °C and 7.0, respectively. HdRed exhibited no appreciable activity toward 28 authentic compounds, including aldehyde, aldose, ketose, α-keto-acid, uronic acid, deoxy sugar, sugar alcohol, carboxylic acid, ketone, and ester. The amino acid sequence of 371 residues of HdRed deduced from the cDNA showed 18–60% identities to those of aldo-keto reductase (AKR) superfamily enzymes, such as human aldose reductase, halophilic bacterium reductase, and sea hare norsolorinic acid (a polyketide derivative) reductase-like protein. Catalytic residues and cofactor binding residues known in AKR superfamily enzymes were fairly well conserved in HdRed. Phylogenetic analysis for HdRed and AKR superfamily enzymes indicated that HdRed is an AKR belonging to a novel family. PMID:26555267

  20. Matrix Isolation Spectroscopy of H2O2, D2O, and HDO in Solid Parahydrogen

    National Research Council Canada - National Science Library

    Fajardo, Mario

    2003-01-01

    ...) solids doped with H2O, D2O and HDO molecules. Analysis of the rovibrational spectra of the isolated H20, D2O and HDO monomers reveals their existence as very slightly hindered rotors, typically showing only 2 to 5...

  1. Weyl and transverse diffeomorphism invariant spin-2 models in D=2+1

    Science.gov (United States)

    Dalmazi, Denis; dos Santos, A. L. R.; Ghosh, Subir; Mendonça, E. L.

    2017-09-01

    There are two covariant descriptions of massless spin-2 particles in D=3+1 via a symmetric rank-2 tensor: the linearized Einstein-Hilbert (LEH) theory and the Weyl plus transverse diffeomorphism (WTDIFF) invariant model. From the LEH theory one can obtain the linearized new massive gravity (NMG) in D=2+1 via Kaluza-Klein dimensional reduction followed by a dual master action. Here we show that a similar route takes us from the WTDIFF model to a linearized scalar-tensor NMG which belongs to a larger class of consistent spin-0 modifications of NMG. We also show that a traceless master action applied to a parity singlet furnishes two new spin-2 self-dual models. Moreover, we examine the singular replacement h_{μ ν } → h_{μ ν } - η _{μ ν }h/D and prove that it leads to consistent massive spin-2 models in D=2+1. They include linearized versions of unimodular topologically massive gravity (TMG) and unimodular NMG. Although the free part of those unimodular theories are Weyl invariant, we do not expect any improvement in the renormalizability. Both the linearized K-term (in NMG) and the linearized gravitational Chern-Simons term (in TMG) are invariant under longitudinal reparametrizations δ h_{μ ν } = partial _{μ }partial _{ν }ζ , which is not a symmetry of the WTDIFF Einstein-Hilbert term. Therefore, we still have one degree of freedom whose propagator behaves like 1/p^2 for large momentum.

  2. Definitive difference among [DS-D2O], [DS-H2O] and [Bulk-D2O] cells in the deuterization and deuterium-reaction

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue Chang

    2000-01-01

    We observed a new phenomena that the enormous amount of deuterium/hydrogen can be absorbed quickly as a 'solute-atom' into fine metal powders embedded inside a double-structure (DS) cathode in the electrolyses of D 2 O and H 2 O-electrolytes, respectively, but such highly deuterated powders can be produced only using DS-cathode immersed in D 2 O-electrolyte; [DS-D 2 O], and never generated in H 2 O-electrolyte even using the DS-cathode; [DS-H 2 O]. On the other hand, [Bulk-D 2 O] with bulk-cathode made by the bulk Pd metal never produces highly deuterated metal as mentioned above even though using D 2 O-electrolyte. In short, the deuterium-concentration generating in [Bulk-D 2 O] is found to be much lower than that in [DS-D 2 O]. As a result, because of reason mentioned above, in marked contrast to the case with the [DS-D 2 O], neither excess heat nor 4 He production are observed with both [DS-H 2 O] and [Bulk-D 2 O]. (author)

  3. Distillation of hydrogen isotopes for polarized HD targets

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, T., E-mail: takeshi@rcnp.osaka-u.ac.jp [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Bouchigny, S. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); CEA LIST, BP6-92265 Fontenay-aux-Roses, CEDEX (France); Didelez, J.-P. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Fukuda, K. [Kansai University of Nursing and Health Sciences, Shizuki Awaji 656-2131 (Japan); Kohri, H.; Kunimatsu, T.; Morisaki, C.; Ono, S. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Rouille, G. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); Tanaka, M. [Kobe Tokiwa University, Ohtani-cho 2-6-2, Nagata, Kobe 653-0838 (Japan); Ueda, K.; Uraki, M.; Utsuro, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Wang, S.Y. [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Physics, National Kaohsiung Normal University, Kaohsiung 824, Taiwan (China); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan)

    2012-02-01

    We have developed a new cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for polarized HD targets in LEPS experiments at SPring-8. A small amount of ortho-H{sub 2} ({approx}0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1-5% impurities of H{sub 2} and D{sub 2} in commercially available HD gases, it is necessary to purify the HD gas up to {approx}99.99%. The distillation system is equipped with a cryogenic distillation unit filled with many small stainless steel cells called 'Heli-pack'. The distillation unit consists of a condenser part, a rectification part, and a reboiler part. The unit is kept at the temperature of 17-21 K. The Heli-pack has a large surface area that makes a good contact between gases and liquids. An amount of 5.2 mol of commercial HD gas is fed into the distillation unit. Three trials were carried out to purify the HD gas by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. One mol of HD gas with a purity better than 99.99% has been successfully obtained for the first time. The effective NTP (Number of Theoretical Plates), which is an indication of the distillation performances, is obtained to be 37.2{+-}0.6. This value is in good agreement with a designed value of 37.9. The HD target is expected to be efficiently polarized under a well-controlled condition by adding an optimal amount of ortho-H{sub 2} to the purified HD gas.

  4. Synthesis of 25-hydroxy-[26,27-3H]vitamin D2, 1,25-dihydroxy-[26,27-3H]vitamin D2 and their (24R)-epimers

    International Nuclear Information System (INIS)

    Sicinski, R.R.; Tanaka, Y.; Phelps, M.; Schnoes, H.K.; DeLuca, H.F.

    1987-01-01

    Synthesis of a C-24-epimeric mixture of 25-hydroxy-[26,27- 3 H]vitamin D2 and a C-24-epimeric mixture of 1,25-dihydroxy-[26,27- 3 H]vitamin D2 by the Grignard reaction of the corresponding 25-keto-27-nor-vitamin D2 and 1 alpha-acetoxy-25-keto-27-nor-vitamin D3 with tritiated methyl magnesium bromide is described. Separation of epimers by high-performance liquid chromatography afforded pure radiolabeled vitamins of high specific activity (80 Ci/mmol). The identities and radiochemical purities of 25-hydroxy-[26,27- 3 H[vitamin D2 and 1,25-dihydroxy-[26,27- 3 H]vitamin D2 D2 were established by cochromatography with synthetic 25-hydroxyvitamin D2 or 1,25-dihydroxyvitamin D2. Biological activity of 25-hydroxy-[26,27- 3 H]vitamin D2 was demonstrated by its binding to the rat plasma binding protein for vitamin D compounds, and by its in vitro conversion to 1,25-dihydroxy-[26,27- 3 H]vitamin D2 by kidney homogenate prepared from vitamin D-deficient chickens. The biological activity of 1,25-dihydroxy-[26,27- 3 H]vitamin D2 was demonstrated by its binding to the chick intestinal receptor for 1,25-dihydroxyvitamin D3

  5. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2 and 118-H-3 Solid Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Vialetti

    2008-05-20

    This report presents the final hazard categorization for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site.

  6. Transfer of π- from hydrogen to deuterium in H2O + D2O mixtures

    International Nuclear Information System (INIS)

    Stanislaus, S.; Measday, D.F.; Vetterli, D.; Weber, P.; Aniol, K.A.; Harston, M.R.; Armstrong, D.S.

    1989-07-01

    The transfer of stopping π - mesons from hydrogen to deuterium has been investigated in mixtures of H 2 O+D 2 O as a function of D 2 O concentration. The concentration dependence of the transfer probability is similar to that observed for the gas mixtures of H 2 and D 2 but slightly more transfer is found for H 2 O+D 2 O. (Author) 17 refs., 2 tabs., 4 figs

  7. Thermally activated 3D to 2D structural transformation of [Ni{sub 2}(en){sub 2}(H{sub 2}O){sub 6}(pyr)]·4H{sub 2}O flexible coordination polymer

    Energy Technology Data Exchange (ETDEWEB)

    Begović, Nebojša N. [Faculty of Physical Chemistry, University of Belgrade (Serbia); Institute of General and Physical Chemistry, Belgrade (Serbia); Blagojević, Vladimir A. [Faculty of Physical Chemistry, University of Belgrade (Serbia); Ostojić, Sanja B.; Radulović, Aleksandra M. [Institute of General and Physical Chemistry, Belgrade (Serbia); Poleti, Dejan [Faculty of Technology and Metallurgy, University of Belgrade (Serbia); Minić, Dragica M., E-mail: dminic@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade (Serbia); Department of Biomedical Sciences, State University of Novi Pazar (Serbia)

    2015-01-15

    Thermally activated 3D to 2D structural transformation of the binuclear [Ni{sub 2}(en){sub 2}(H{sub 2}O){sub 6}(pyr)]·4H{sub 2}O complex was investigated using a combination of theoretical and experimental methods. Step-wise thermal degradation (dehydration followed by release of ethylene diamine) results in two layered flexible coordination polymer structures. Dehydration process around 365 K results in a conjugated 2D structure with weak interlayer connectivity. It was shown to be a reversible 3D to 2D framework transformation by a guest molecule, and rehydration of the dehydration product occurs at room temperature in saturated water vapor. Rehydrated complex exhibits lower dehydration temperature, due to decreased average crystalline size, with higher surface area resulting in easier release and diffusion of water during dehydration. Thermal degradation of dehydration around 570 K, results in loss of ethylene diamine, producing a related 2D layered polymer structure, without interconnectivity between individual polymer layers. - Highlights: • Reversible 3D to 2D framework topochemical transformation on dehydration around 365 K. • Resulting polymer exhibits 2D layered structure with weak interlayer connectivity. • Dehydration is fully reversible in saturated water vapor at room temperature. • Further degradation around 570 K yields 2D polymer without interlayer connectivity. • 2D polymer exhibits conjugated electronic system.

  8. New determination of the 2H(d,p)3H and 2H(d,n)3He reaction rates at astrophysical energies

    International Nuclear Information System (INIS)

    Tumino, A.; Spartà, R.; Spitaleri, C.; Pizzone, R. G.; La Cognata, M.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Mukhamedzhanov, A. M.; Typel, S.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.; Burjan, V.; Kroha, V.; Hons, Z.; Mrazek, J.; Piskor, S.; Lamia, L.

    2014-01-01

    The cross sections of the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions have been measured via the Trojan Horse method applied to the quasi-free 2 H( 3 He,p 3 H) 1 H and 2 H( 3 He,n 3 He) 1 H processes at 18 MeV off the proton in 3 He. For the first time, the bare nucleus S(E) factors have been determined from 1.5 MeV, across the relevant region for standard Big Bang nucleosynthesis, down to the thermal energies of deuterium burning in the pre-main-sequence (PMS) phase of stellar evolution, as well as of future fusion reactors. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from the available direct data and existing fitting curves, with substantial variations in the electron screening by more than 50%. As a consequence, the reaction rates for astrophysics experience relevant changes, with a maximum increase of up to 20% at the temperatures of the PMS phase. From a recent primordial abundance sensitivity study, it turns out that the 2 H(d,n) 3 He reaction is quite influential on 7 Li, and the present change in the reaction rate leads to a decrease in its abundance by up to 10%. The present reaction rates have also been included in an updated version of the FRANEC evolutionary code to analyze their influence on the central deuterium abundance in PMS stars with different masses. The largest variation of about 10%-15% pertains to young stars (≤1 Myr) with masses ≥1 M ☉ .

  9. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

    International Nuclear Information System (INIS)

    Rodovsky, T.J.

    2006-01-01

    This report presents the final hazard categorization (FHC) for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site

  10. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    T. J. Rodovsky

    2006-12-06

    This report presents the final hazard categorization (FHC) for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site.

  11. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    T. J. Rodovsky

    2007-04-12

    This report presents the final hazard categorization (FHC) for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site.

  12. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

    International Nuclear Information System (INIS)

    TRodovsky, T.J.

    2007-01-01

    This report presents the final hazard categorization (FHC) for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site

  13. Stability of globular proteins in H2O and in D2O

    NARCIS (Netherlands)

    Efimova, Y.M.; Haemers, S.; Wierczinsky, B.; Norde, W.; Well, van A.A.

    2007-01-01

    In several experimental techniques D2O rather then H2O is often used as a solvent for proteins. Concerning the influence of the solvent on the stability of the proteins, contradicting results have been reported in literature. In this paper the influence of H2O-D2O solvent substitution on the

  14. Ion-molecule interactions in crossed-beams. [N/sup +/-H/sub 2/; F/sup +/-H; CO/sub 2//sup +/-D/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S.G.

    1980-09-01

    Interactions of the ions N/sup +/, F/sup +/, and CO/sub 2//sup +/ with H/sub 2/ and/or its isotopes were examined using the crossed-beam technique in the low (< 4 eV) initial relative energy. For the reaction N/sup +/(/sup 3/P) + H/sub 2/ ..-->.. NH/sup +/ + H, complex formation dominates up to 1.9 eV and a substantial interaction occurs between all collision partners up to 3.6 eV. The distribution of N/sup +/ scattered nonreactively from H/sub 2/ also showed a long-lived complex channel below 1.9 eV. The reaction F/sup +/(/sup 3/P) + H/sub 2/ ..-->..FH/sup +/ + H proceeded by a direct reaction mechanism at 0.20 to 1.07 eV. The reaction CO/sub 2//sup +/ + D/sub 2/ ..-->.. DCO/sub 2//sup +/ + D gives asymmetric product distributions at 0.27 eV and above, indicating a direct reaction mechanism. Results indicated that there are probably barriers in the exit channels for DCO/sub 2//sup +/, DCO/sup +/, and D/sub 2/O/sup +/ products. The electronic state distributions of the N/sup +/, F/sup +/, and CO/sub 2//sup +/ beams was investigated using beam attenuation and total luminescence techniques.

  15. The H{sup +}{sub 3} + H{sub 2} isotopic system. Origin of deuterium astrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hugo, Edouard Jean-Marie

    2008-07-01

    Dense cold molecular clouds reckoned to be stellar nurseries are the scene of an extreme molecular deuteration. Despite the cosmic D/H ratio of {proportional_to}10{sup -5}, molecular species in prestellar cores are observed to contain nearly as much deuterium as hydrogen. This astonishing deuterium enrichment promoted by low temperatures is the work of H{sup +}{sub 3}. It is the key species which unlocks the deuterium from its HD reservoir via reactions like H{sup +}{sub 3}+HD {r_reversible} H{sub 2}D{sup +}+H{sub 2} and drags it further to other species in successive reactions. For this reason, the H{sup +}{sub 3}+H{sub 2} isotopic system is outstandingly critical for the astrochemistry of cold environments. However, its understanding is yet incomplete and insufficient. This thesis thus focuses on the H{sup +}{sub 3}+H{sub 2} isotopic system from a theoretical, experimental and astronomical point of view giving a particular look into the role of nuclear spins. As a first step, the stringent nuclear spin selection rules in associative, dissociative and reactive collisions are investigated. This purely theoretical study zooms into the details of the nuclear spin wavefunctions and shows that their permutation symmetry representation is necessary and sufficient, contrary to their angular momentum representation. Additionally, a new deterministic interpretation of nuclear spins in chemical reactions is proposed. Based on these considerations, a complete set of state-to-state rate coefficients for all H{sup +}{sub 3} + H{sub 2} isotopic variants is calculated using a microcanonical model leaned on phase space theory. An experimental study is conducted in parallel with a 22-pole ion trap apparatus in order to inspect the influences of temperature and H{sub 2} ortho-to-para ratio. The good overall agreement between experimental and theoretical results supports the validity and utility of the calculated set of rate coefficients. Furthermore, the potentiality of the 22-pole

  16. The H2O/D2O exchange across vesicular lipid bilayers

    International Nuclear Information System (INIS)

    Engelbert, H.P.; Lawaczek, R.

    1985-01-01

    A new method to measure the water (D 2 O/H 2 O) permeation across vesicular lipid bilayers is described. The method is based on the solvent isotope effect of the light scattering which is a consequence of the different indices of refraction of D 2 O and H 2 O. Unilamellar lipid vesicles in excess of H 2 O are rapidly mixed with D 2 O or vice versa. As result of the H 2 O/D 2 O exchange across the vesicular bilayer the light scattering signal has a time dependent, almost single exponential component allowing the deduction of the exchange relaxation rate and, at known size, of the permeability coefficient. The experimental results are in accord with calculations from the Mie theory of light scattering for coated spheres. The method is applicable for large vesicles where the permeation is the rate-limiting step. Size separations are performed by a flow dialysis through a sequence of pore-membrane-filters. For dimyristoyl-lecithin bilayers the water permeability-coefficient is 1.9 . 10 -5 cm/s in the crystalline phase and increases by a factor of 10-100 in the liquid-crystalline state. The temperature dependence of the permeation exhibits a sharp change at the phase transition. For binary mixtures of lecithins this sharp change follows the solidus curve of the non-ideal phase diagram determined by spectroscopic techniques. (orig.)

  17. First use of a laser-driven polarized H/D target at the IUCF cooler

    International Nuclear Information System (INIS)

    Bailey, K.; Brack, J.; Cadman, R. V.; Cummings, W. J.; Fedchak, J.; Fox, B.; Gao, H.; Grosshauser, C.; Holt, R. J.; Jones, C.; Kinney, E.; Kowalczyk, R.; Lu, Z.-T.; Miller, M. A.; Nagengast, W.; Owen, B.; Rith, K.; Schmidt, F.; Schulte, E.; Sowinski, J.; Sperisen, F.; Stenger, J.; Thorsland, E.; Williamson, S.

    1997-01-01

    The HERMES Laser-Driven Target Task Force (Argonne, Erlangen and Illinois) is charged with developing a polarized H/D target for use in the HERA ring at DESY. Rapid progress was made in the beginning of 1996, leading us to the decision to test the target in a realistic experimental environment. In particular, polarizations of 0.6 and flows above 10 18 atoms·s -1 have been achieved on the bench. The laser-driven target and a simple detector system are currently installed in Cooler storage ring at the Indiana University Cyclotron Facility in order to test its applicability to nuclear physics experiments. Target polarizations are being measured using the rvec H(p, p) and rvec D(p, p) reactions. Initial tests were reasonably successful and the target is well along toward becoming viable for nuclear physics

  18. 3-D dosimetric evaluation of 2.5 mm HD120 multileaf system for intensity modulated stereotactic radiosurgery using optical CT based polymer gel dosimetry

    International Nuclear Information System (INIS)

    Wuu, C-S; Kessel, Jack; Xu, Y

    2009-01-01

    A Trilogy TX equipped with a 2.5 mm HD120 multileaf collimator system is available for the treatment of radiosurgery and IMRT. In this study, we evaluated the 3-D dosimetric impact of leaf width on an IMRT radiosurgery plan by comparing the target coverage and the dose gradient around the target, produced from both a 2.5 mm HD120 high-definition MLC system and a 5mm-leaf-width millennium 120 MLC system, using an optical CT based polymer gel dosimetry system. The 2.5 mm MLC improves target conformity and surrounding tissue sparing when compared to that of 5 mm MLC.

  19. Weighted linear regression using D2H and D2 as the independent variables

    Science.gov (United States)

    Hans T. Schreuder; Michael S. Williams

    1998-01-01

    Several error structures for weighted regression equations used for predicting volume were examined for 2 large data sets of felled and standing loblolly pine trees (Pinus taeda L.). The generally accepted model with variance of error proportional to the value of the covariate squared ( D2H = diameter squared times height or D...

  20. Analytical Description of the H/D Exchange Kinetic of Macromolecule.

    Science.gov (United States)

    Kostyukevich, Yury; Kononikhin, Alexey; Popov, Igor; Nikolaev, Eugene

    2018-04-17

    We present the accurate analytical solution obtained for the system of rate equations describing the isotope exchange process for molecules containing an arbitrary number of equivalent labile atoms. The exact solution was obtained using Mathematica 7.0 software, and this solution has the form of the time-dependent Gaussian distribution. For the case when forward exchange considerably overlaps the back exchange, it is possible to estimate the activation energy of the reaction by obtaining a temperature dependence of the reaction degree. Using a previously developed approach for performing H/D exchange directly in the ESI source, we have estimated the activation energies for ions with different functional groups and they were found to be in a range 0.04-0.3 eV. Since the value of the activation energy depends on the type of functional group, the developed approach can have potential analytical applications for determining types of functional groups in complex mixtures, such as petroleum, humic substances, bio-oil, and so on.

  1. 1H NMR study of 2-deoxy-D-arabino-hexopyranose (2-deoxy-glucopyranose), 2-deoxy-D-lyxo-hexopyranose (2-deoxy-galactopyranose) and 2'-deoxy lactose

    International Nuclear Information System (INIS)

    Bruyn, A. de; Anteunis, M.

    1975-01-01

    Complete analyses of the 1 H n.m.r. spectra at 300 MHz of D 2 O solutions of 2-deoxy-D-arabino-hexopyranose, 2-deoxy-D-lyxo-hexopyranose and 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose are compared with those previously obtained in the parent aldeohexopyranoses, glucobioses and D-galactopyranosol-D-glucoses. Increment values are suggested in order to predict chemical shifts in 2-deoxy derivatives from the well known rules for aldohexopyranoses. (author)

  2. Positronium formation and hydrated positron reactions in H2O, D2O, 1.74 M PPS/H2O and 1.74 M PPS/D2O solutions of Cl−, Br− and I−

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Pedersen, Niels Jørgen

    1986-01-01

    Angular correlation of annihilation photons were measured for H2O, D2O, 1.74 M PPS/H2O and 1.74 M PPS/D2O solutions of Cl−, Br− and I−. The three components of the angular correlation spectra for D2O and H2O were nearly identical in shape. The positronium (Ps) yields for the H2O and D2O solutions...... before annihilation (lifetime 400 ps) was determined for the three halides in the four solvents. Simple kinetic equations (“trapping model”) with time dependent rate constant, solved analytically, could explain the [X−, e+] formation in H2O fairly well for concentrations below 0.03 M X−, if a diffusion...... controlled reaction with positron diffusion constant D = 5 × 10−5 cm2/s and reaction radius R = 1 nm were assumed. The three halides gave roughly identical [X−, e+] formation below 0.03 M X−. The difference between the four solutions could be explained partly only in terms of viscosity change for the model...

  3. Dissociative ionization of H2 and D2 by electron impact near threshold

    NARCIS (Netherlands)

    Boesten, L.G.J.; Heideman, H.G.M.

    We have studied the dissciative ionization of H2 and D2 by electron impact. It is found that in the vicinity of the 2Σ+g dissociation threshold of H+2 (18.08 eV) a significant fraction of the produced protons originates from the process e + H2 → H− + H+ + e (threshold at 17.34 eV). Similar results

  4. Bare nucleus S(E) factor of the 2H(d,p)3H and 2H(d,n)3He reactions via the Trojan Horse Method

    International Nuclear Information System (INIS)

    Tumino, A; Spitaleri, C; Kiss, G G; Cognata, M La; Lamia, L; Pizzone, R G; Rapisarda, G G; Romano, S; Sergi, M L; Spartà, R; Mukhamedzhanov, A M; Typel, S; Aliotta, M; Burjan, V; Kroha, V; Hons, Z; Mrazek, J; Piskor, S; Santo, M Gimenez del

    2012-01-01

    The Trojan Horse Method was applied for the first time to the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions by measuring the 2 H( 3 He,p 3 H) 1 H and 2 H( 3 He,n 3 He) 1 H processes in quasi free kinematics. The 3 He+d experiment was performed at 18 MeV, corresponding the a d-d energy range from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre Main Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the bare nucleus S(E) factors have been extracted for the first time. They deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3 H+p and 60.1±1.9 MeVb for 3 He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  5. Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Ludowise

    2009-06-17

    This report presents the final hazard categorization for the remediation of the 118-D-1, 118-D-2, 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site. A material at risk calculation was performed that determined the radiological inventory for each burial ground to be Hazard Category 3.

  6. Effects of Hd2 in the presence of the photoperiod-insensitive functional allele of Hd1 in rice

    Directory of Open Access Journals (Sweden)

    Zhen-Hua Zhang

    2016-11-01

    Full Text Available The role of photoperiod sensitivity (PS of flowering genes have become well recognized in rice, whereas little attention has been drawn to the non-PS component of these genes, especially to their influence on gene-by-gene interactions. Rice populations in which the photoperiod-sensitive allele at Hd1 has become insensitive to photoperiod but continued to affect heading date (HD were used in this study to fine-map a quantitative trait locus (QTL for HD and analyze its genetic relationship to Hd1. The QTL was delimitated to a 96.3-kb region on the distal end of the long arm of chromosome 7. Sequence comparison revealed that this QTL is identical to Hd2. In the near-isogenic line (NIL populations analyzed, Hd1 and Hd2 were shown to be photoperiod insensitive and have pleiotropic effects for HD, plant height and yield traits. The two genes were found to largely act additively in regulating HD and yield traits. The results indicate that non-PS components of flowering genes involved in photoperiod response play an important role in controlling flowering time and grain yield in rice, which should allow breeders to better manipulate pleiotropic genes for balancing adaptability and high-yielding accumulation.

  7. Kinetics of the radiation-induced exchange reactions of H2, D2, and T2: a review

    International Nuclear Information System (INIS)

    Pyper, J.W.; Briggs, C.K.

    1978-01-01

    Mixtures of H 2 --T 2 or D 2 --T 2 will exchange to produce HT or DT due to catalysis by the tritium β particle. The kinetics of the reaction D 2 + T 2 = 2DT may play an important role in designing liquid or solid targets of D 2 --DT--T 2 for implosion fusion, and distillation schemes for tritium cleanup systems in fusion reactors. Accordingly, we have critically reviewed the literature for information on the kinetics and mechanism of radiation-induced self-exchange reactions among the hydrogens. We found data for the reaction H 2 + T 2 = 2HT in the gas phase and developed a scheme based on these data to predict the halftime to equilibrium for any gaseous H 2 + T 2 mixture at ambient temperature with an accuracy of +-10 percent. The overall order of the H 2 + T 2 = 2HT reaction is 1.6 based on an initial rate treatment of the data. The most probable mechanism for radiation-induced self-exchange reaction is an ion-molecule chain mechanism

  8. Heavily-doped 2D-quantized structures and the Einstein relation

    CERN Document Server

    Ghatak, Kamakhya P

    2015-01-01

    This book presents the Einstein Relation(ER) in two-dimensional (2-D) Heavily Doped(HD) Quantized Structures. The materials considered are quantized structures of HD non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, GaP, Gallium Antimonide, II-V, Bismuth Telluride together with various types of HD superlattices and their Quantized counterparts respectively. The ER in HD opto-electronic materials and their nanostructures is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestion for the experimental determination of HD 2D and 3D ERs and the importance of measurement of band gap in HD optoelectronic materials under intense built-in electric field in nanodevices and strong external photo excitation (for measuring photon induced physical properties) are also discussed in this context. The influence of crossed electric and quantizing ma...

  9. 1H and 2H NMR relaxation study on the phase transitions of (NH4)3H(SO4)2 and (ND4)3D(SO4)2 single crystals

    International Nuclear Information System (INIS)

    Lim, Ae Ran; Jeong, Se-Young

    2006-01-01

    T 1 , T 1ρ and T 2 for the 1 H and 2 H nuclei in (NH 4 ) 3 H(SO 4 ) 2 and (ND 4 ) 3 D(SO 4 ) 2 single crystals grown using the slow evaporation method were measured for phases I, II, III, IV and V. The 1 H T 1 , T 1ρ , and T 2 values were found to exhibit different trends in phases II and III: T 1 , T 1ρ and T 2 for 1 H do not change significantly near the phase transition at 265 K, whereas near 413 K they change discontinuously. We conclude that the NH 4 + and H(SO 4 ) 2 - ions do not play an important role in the III-II phase transition, but do play important roles in the II-I phase transition. The liquid-like nature of the 1 H T 1ρ and T 2 above 413 K is indicative of the destruction and reconstruction of hydrogen bonds. Moreover, the phase transitions of the (NH 4 ) 3 H(SO 4 ) 2 crystal are accompanied by changes in the molecular motion of the (NH 4 ) + ions. The variations with temperature of the 2 H T 1 and T 2 of (ND 4 ) 3 D(SO 4 ) 2 crystals are not similar to those observed for the 1 H T 1 and T 2 . Our comparison of the results for (NH 4 ) 3 H(SO 4 ) 2 and (ND 4 ) 3 D(SO 4 ) 2 crystals indicates the following: the 1 H T 1ρ and T 2 of the (NH 4 ) + and H(SO 4 ) 2 - ions above T C1 are characteristic of fast, liquid-like motion, which is not the case for (ND 4 ) 3 D(SO 4 ) 2 ; and the 2 H T 1 of D(SO 4 ) 2 - in (ND 4 ) 3 D(SO 4 ) 2 is longer than the 2 H T 1 of (ND 4 ) + in contrast to the results for (NH 4 ) 3 H(SO 4 ) 2 crystals

  10. Quantum stereodynamics study for the reaction F + HD

    International Nuclear Information System (INIS)

    Yu-Fang, Liu; Wei, Zhang; De-Heng, Shi; Jin-Feng, Sun

    2009-01-01

    This paper studies the quantum stereodynamics of the F + HD(ν = 0,j = 0) → HD + F/HF + D reaction at the collision energies of 0.52 and 0.87 kcal/mol. The quantum scattering calculations, based on Stark–Werner potential energy surfaces, show that the differential cross sections for the HF(ν' = 2) + D and DF(ν' = 3) + H channels are consistent with the recent theoretical results. Furthermore, the product rotational angular momentum orientation and alignment have been determined for some selected rovibrational states of the HF + D and DF + H channels. (atomic and molecular physics)

  11. THz spectroscopy of liquid H2O and D2O

    DEFF Research Database (Denmark)

    Rønne, C.; Åstrand, P.-O.; Keiding, S.R.

    1999-01-01

    We have measured and analyzed the dielectric (0.1-2 THz) response of liquid H2O and D2O from 270 to 365 K. The response has been modeled using a Debye model with a fast and a slow decay time. By shifting the temperature scale for the slow decay time of D2O by 7.2 K we find identical behavior for D2......O and H2O. The temperature dependence and isotope shift of the intermolecular structural relaxation characterized by the slow decay time can be modeled with a singular point at 228 K for H2O and 235 K for D2O. [S0031-9007(99)08896-1]....

  12. The localized vibrations of H-H-, D-D- and H-D- pairs in KCl, KBr, KI, RbCl and NaCl

    International Nuclear Information System (INIS)

    Robert, R.

    1974-01-01

    The localized vibrational modes of H - H - , D - D - and H - D - pairs in KCl, KBr, KI, RbCl and NaCl were studied for different pair configurations. The measured frequencies of the infrared active modes were found to be in good agreement with a model of two coupled harmonic oscillators. The line width for different modes in the salts studied is discussed. The temperature dependence for the transversal modes T 1 and T 2 of the line width for the H - H - pairs in KCl indicates that the broadening of these lines is due to the 'decomposition mechanism', that generates two phonons. The generated phonons due to the decay of the localized in phase mode are: -one acustic phonon of the lattice, -one localized phonon that corresponds to the out of phase vibration of the H - H - pair. The general properties, as the Ivey law and several particulars of the properties in the alkali-halides studied are presented [pt

  13. Symmetry Breakdown in Ground State Dissociation of HD+

    International Nuclear Information System (INIS)

    Ben-Itzhak, I.; Wells, E.; Carnes, K. D.; Krishnamurthi, Vidhya; Weaver, O. L.; Esry, B. D.

    2000-01-01

    Experimental studies of the dissociation of the electronic ground state of HD + following ionization of HD by fast proton impact indicate that the H + +D 1s dissociation channel is more likely than the H1s+D + dissociation channel by about 7% . This isotopic symmetry breakdown is due to the finite nuclear mass correction to the Born-Oppenheimer approximation which makes the 1sσ state 3.7 meV lower than the 2pσ state at the dissociation limit. The measured fractions of the two dissociation channels are in agreement with coupled-channels calculations of 1sσ to 2pσ transitions. (c) 2000 The American Physical Society

  14. Adsorbed Layers of D2, H2, O2, and 3He on Graphite Studied by Neutron Scattering

    DEFF Research Database (Denmark)

    Nielsen, Mourits; McTague, J. P.; Ellenson, W. D.

    1977-01-01

    The phase diagrams of adsorbed monolayers of D2, H2, O2, and 3He on graphite have been measured by neutron diffraction. H2 and D2-layers have a registered √3 structure at low coverages, and at monolayer completion they have a dense triangular structure, which is incommensurate with the substrate...

  15. Neutron Spectra in H{sub 2}O, D{sub 2}O, BeO and CH{sub 2}; Spectres de Neutrons dans H{sub 2}O, D{sub 2}O, BeO et CH{sub 2}; Spektry nejtronov v H{sub 2}O, D{sub 2}O, BeO i CH{sub 2}; Espectros Neutronicos en H{sub 2}O, D{sub 2}O, BeO y CH{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Neill, J. M.; Young, J. C.; Trimble, G. D.; Beyster, J. R. [General Atomic Division of General Dynamics Corporation, John Jay Hopkins Laboratory for Pure and Applied Science, San Diego, CA (United States)

    1965-08-15

    Thermal neutron spectral measurements in moderators of interest to reactor technology are being made at General Atomic. The purpose of these measurements is to provide an integral check of the adequacy of proposed scattering models for these moderators. At present the scattering kernels are obtained by measuring the double differential scattering cross-sections directly, or by inferring them from a study of the vibrational and rotational motions of the molecules in a liquid or the lattice vibrational spectrum in a solid. The direct measurement has suffered from some experimental difficulties, such as obtaining the desired intensity and resolution and making the proper corrections for multiple scattering in the sample. From the standpoint of the application to reactor technology, the latter procedure for obtaining the scattering kernel has been more satisfactory in many instances. The integral measurements that have been made, coupled to comparative calculations of the neutron spectra, allow comment to be made on the status of the theoretical scattering models for H{sub 2}O, D{sub 2}O and BeO. In this paper, angular- and position-dependent spectra measured in H{sub 2}O and D{sub 2}O poisoned with boron or cadmium are presented and show improved agreement with the theoretical values. It appears that the Nelkin model for H{sub 2}O provides a reasonable first description for the scattering by that moderator. It also appears that the Honeck model for D{sub 2}O, an extension of the incoherent model for H{sub 2}O of Nelkin, is also an adequate description for some applications. This is surprising since deuterium, unlike hydrogen, is mostly a coherent scatterer; however it supports recent studies by Koppel which showed that the intramolecular and intermolecular interference scattering terms in D{sub 2}O tend to cancel. Measured angularly-dependent neutron spectra in BeO poisoned with borated stainless steel are also presented. In general the agreement of measurement with

  16. Calculation of the cross section of the H2+(D2+)+Li→Li++2H(2D) charge-exchange reaction

    International Nuclear Information System (INIS)

    Voronin, A.I.; Osherov, V.I.; Poluyanov, L.V.; Ushakov, V.G.

    1983-01-01

    The method of classic trajectories with account for non-adiabatic transitions has been used to calculate Li atoms charge-exchange cross sections on H 2 + and D 2 + ions depending on collision energy and oscillatory excitation of molecular ion. Surfaces of potentil energy of nuclei interaction corresponding to essential for the chargeexchange process electron states are plotted by the diatomics-in-molecules (DIM) method. Qualitative characteristics of calculated cross sections (dependence on collision energy, oscillatory number, deuteration effect) coincide well with those obtained during the experiment. However the experimental cross section value approximately two times surpasses the theoretical one. This is connected with insufficient accuracy of the DIM method

  17. The ‘sub’ metallide oxide hydrides Sr{sub 21}Si{sub 2}O{sub 5}H{sub 12+x} and Ba{sub 21}M{sub 2}O{sub 5}H{sub 12+x} (M = Zn, Cd, Hg, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Jehle, Michael; Hoffmann, Anke [Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, D-79104 Freiburg (Germany); Kohlmann, Holger [Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, D-04103 Leipzig (Germany); Scherer, Harald [Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, D-79104 Freiburg (Germany); Röhr, Caroline, E-mail: caroline@ruby.chemie.uni-freiburg.de [Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, D-79104 Freiburg (Germany)

    2015-02-25

    Highlights: • The sub metallide oxide hydrides (Sr/Ba){sub 21}M{sub 2}O{sub 5}H{sub 12+x} were prepared for 14 M elements. • M covers a wide range of elements, from the Zn group to the pentels. • The ionic partial structure contains isolated M anions and suboxide clusters [O{sub 5}A{sub 18}]. • The H-content was determined by neutron diffraction and {sup 1}H/{sup 2}D MAS-NMR spectroscopy. • Band structure calculations support the H/D content and distribution. - Abstract: The title compounds sporting a great variety of anions M of different formal charges have been synthesized from melts of the composition A:M:O:H/D = 21:2:5:24, using BaH{sub 2}/SrH{sub 2} as hydrogen sources. All phases were characterized by means of single crystal X-ray data [cubic, space group Fd3{sup ¯}m; Sr{sub 21}Si{sub 2}O{sub 5}H{sub 12+x}: a = 1911.90(1) pm, R1 = 0.0201; for the barium phases with Zn (a = 2041.7(3) pm, R1 = 0.077), Cd (a = 2063.3(1) pm, R1 = 0.051), Hg (a = 2050.7(1) pm, R1 = 0.059), In (a = 2060.7(1) pm, R1 = 0.101), Tl (a = 2068.1(10) pm, R1 = 0.0485), Si (a = 2033.6(1) pm, R1 = 0.045), Ge (a = 2035.6(1) pm, R1 = 0.037), Sn (a = 2053.2(2) pm, R1 = 0.054), Pb (a = 2059.7(1) pm, R1 = 0.056), As (a = 2023.0(3) pm, R1 = 0.087), Sb (a = 2041.9(1) pm, R1 = 0.067) and Bi (a = 2045.9(1) pm, R1 = 0.075)]. Neutron powder diffraction data collected for the Ba silicide (both H and D compound) were refined by the Rietveld method (a = 2037.0(1), R{sub p} = 0.0173; wR{sub p} = 0.0304, R(F{sup 2}) = 0.086). The statistically occupied (H/D)(1) site 96g, which corresponds to the carbon position inSr{sub 21}Si{sub 2}O{sub 5}C{sub 6}, together with two further sparsely occupied sites (H/D)(2,3), yields the overall composition Ba{sub 21}Si{sub 2}O{sub 5}D{sub 14}. The hydrogen content, its chemical character and the distribution among the three H/D positions was evaluated by {sup 1}H/{sup 2}H MAS NMR spectroscopy for the Si, Ge and Sb compound. The crystal structure exhibits two

  18. Surface tension of H2O and D2O

    International Nuclear Information System (INIS)

    Vargaftik, N.B.; Voljak, L.D.; Volkov, B.N.

    1975-01-01

    There is a great number of works on surface tension of clean water (H 2 O) at temperatures up to 100 deg C and very few above the boiling point. Works on surface tension of heavy water (D 2 O) are insufficient. A review of works on surface tension of both kinds of water is given

  19. Study of negative ion surface production in cesium-free H_2 and D_2 plasmas: application to neutral beam injectors for ITER and DEMO

    International Nuclear Information System (INIS)

    Achkasov, Kostiantyn

    2015-01-01

    The objective of this thesis was to find solutions to produce high yields of H"-/D"- negative ions (NI) on surfaces in Cs-free H_2/D_2 plasmas for thermonuclear fusion applications. Modeling of the negative-ion energy distribution functions (NIEDF) has shown remarkable agreement with experiment for carbon materials. The reconstruction method developed in the course of this thesis has allowed to determine the distribution in energy and angle of NI emitted from the surface. The reconstruction method can be applied to any type of surface and/or NI. A study was performed on a large variety of materials: different types of graphite, diamond films and metals. The influence of surface temperature, bias and plasma exposure time on NI yield was investigated. The method of pulsed bias was developed to enable the study of NI production on surfaces of insulating materials such as microcrystalline non-doped diamond (MCD). The use of ex situ surface diagnostics such as temperature programmed desorption (TPD) and Raman spectroscopy has allowed to characterize the surface state of carbon materials. Basing on the performed studies, we demonstrated that to optimize the NI yield on diamond one has to work with a less degraded surface. This can be obtained rising the surface temperature to 400 C-500 C which allows restoring intrinsic properties of diamond. The less degraded surface state can also be obtained by applying the pulsed bias which gives the possibility to increase the H_2/D_2 surface coverage and diminish the defects induced by plasma exposure. (author) [fr

  20. Ionization and solvation of HCl adsorbed on the D2O-ice surface

    International Nuclear Information System (INIS)

    Kondo, M.; Kawanowa, H.; Gotoh, Y.; Souda, R.

    2004-01-01

    The interaction of HCl with the D 2 O-ice surface has been investigated in the temperature range 15-200 K by utilizing time-of-flight secondary ion mass spectroscopy, temperature-programmed desorption, and x-ray photoelectron spectroscopy. The intensities of sputtered H + (D 2 O) and Cl - ions (the H + ions) are increased (decreased) markedly above 40 K due to the hydrogen bond formation between the HCl and D 2 O molecules. The HCl molecules which form ionic hydrates undergo H/D exchange at 110-140 K and a considerable fraction of them dissolves into the bulk above 140 K. The neutral hydrates of HCl should coexist as evidenced by the desorption of HCl above 170 K. They are incorporated completely in the D 2 O layer up to 140 K. The HCl molecules embedded in the thick D 2 O layer dissolve into the bulk, and the ionic hydrate tends to segregate to the surface above 150 K

  1. The BPS spectrum of the 4d {N}=2 SCFT's H 1, H 2, D 4, E 6, E 7, E 8

    Science.gov (United States)

    Cecotti, Sergio; Del Zotto, Michele

    2013-06-01

    Extending results of 1112.3984, we show that all rank 1 {N}=2 SCFT's in the sequence H 1, H 2, D 4 E 6, E 7, E 8 have canonical finite BPS chambers containing precisely 2 h(F) = 12(∆ - 1) hypermultiplets. The BPS spectrum of the canonical BPS chambers saturates the conformal central charge c, and satisfies some intriguing numerology.

  2. Metal-Free 2D/2D Phosphorene/g-C3 N4 Van der Waals Heterojunction for Highly Enhanced Visible-Light Photocatalytic H2 Production.

    Science.gov (United States)

    Ran, Jingrun; Guo, Weiwei; Wang, Hailong; Zhu, Bicheng; Yu, Jiaguo; Qiao, Shi-Zhang

    2018-04-30

    The generation of green hydrogen (H 2 ) energy using sunlight is of great significance to solve the worldwide energy and environmental issues. Particularly, photocatalytic H 2 production is a highly promising strategy for solar-to-H 2 conversion. Recently, various heterostructured photocatalysts with high efficiency and good stability have been fabricated. Among them, 2D/2D van der Waals (VDW) heterojunctions have received tremendous attention, since this architecture can promote the interfacial charge separation and transfer and provide massive reactive centers. On the other hand, currently, most photocatalysts are composed of metal elements with high cost, limited reserves, and hazardous environmental impact. Hence, the development of metal-free photocatalysts is desirable. Here, a novel 2D/2D VDW heterostructure of metal-free phosphorene/graphitic carbon nitride (g-C 3 N 4 ) is fabricated. The phosphorene/g-C 3 N 4 nanocomposite shows an enhanced visible-light photocatalytic H 2 production activity of 571 µmol h -1 g -1 in 18 v% lactic acid aqueous solution. This improved performance arises from the intimate electronic coupling at the 2D/2D interface, corroborated by the advanced characterizations techniques, e.g., synchrotron-based X-ray absorption near-edge structure, and theoretical calculations. This work not only reports a new metal-free phosphorene/g-C 3 N 4 photocatalyst but also sheds lights on the design and fabrication of 2D/2D VDW heterojunction for applications in catalysis, electronics, and optoelectronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Photodissociaton of allyl-d2 iodide excited at 193 nm: Stability of highly rotationally excited H2CDCH2 radicals to C-D fission

    International Nuclear Information System (INIS)

    Szpunar, D.E.; Liu, Y.; McCullagh, M.J.; Butler, L.J.; Shu, J.

    2003-01-01

    The photodissociation of allyl-d2 iodide (H2C=CDCH2I) and the dynamics of the nascent allyl-d2 radical (H2CCDCH2) were studied using photofragment translational spectroscopy. A previous study found the allyl radical stable at internal energies up to 15 kcal/mol higher than the 60 kcal/mol barrier to allene + H formation as the result of a centrifugal barrier. The deuterated allyl radical should then also show a stability to secondary dissociation at internal energies well above the barrier due to centrifugal effects. A comparison in this paper shows the allyl-d2 radical is stable to allene + D formation at energies of 2-3 kcal/mol higher than that of the non-deuterated allyl radical following photolysis of allyl iodide at 193 nm. This is most likely a result of a combination of the slight raising of the barrier from the difference in zero-point levels and a reduction of the impact parameter of the dissociative fragments due to the decrease in frequency of the C-D bending modes, and the refore allene + D product orbital angular momentum. Integrated signal taken at m/e = 40 (allene) and m/e = 41 (allene-d1 and propyne-d3) shows a minor fraction of the allyl-d2 radicals isomerize to the 2-propenyl radical, in qualitative support of earlier conclusions of the domination of direct allene + H formation over isomerization

  4. 2,5-hexanedione (HD) treatment alters calmodulin, Ca2+/calmodulin-dependent protein kinase II, and protein kinase C in rats' nerve tissues

    International Nuclear Information System (INIS)

    Wang Qingshan; Hou Liyan; Zhang Cuili; Zhao Xiulan; Yu Sufang; Xie, Ke-Qin

    2008-01-01

    Calcium-dependent mechanisms, particularly those mediated by Ca 2+ /calmodulin (CaM)-dependent protein kinase II (CaMKII), have been implicated in neurotoxicant-induced neuropathy. However, it is unknown whether similar mechanisms exist in 2,5-hexanedione (HD)-induced neuropathy. For that, we investigated the changes of CaM, CaMKII, protein kinase C (PKC) and polymerization ratios (PRs) of NF-L, NF-M and NF-H in cerebral cortex (CC, including total cortex and some gray), spinal cord (SC) and sciatic nerve (SN) of rats treated with HD at a dosage of 1.75 or 3.50 mmol/kg for 8 weeks (five times per week). The results showed that CaM contents in CC, SC and SN were significantly increased, which indicated elevation of Ca 2+ concentrations in nerve tissues. CaMKII contents and activities were also increased in CC and were positively correlated with gait abnormality, but it could not be found in SC and SN. The increases of PKC contents and activities were also observed in SN and were positively correlated with gait abnormality. Except for that of NF-M in CC, the PRs of NF-L, NF-M and NF-H were also elevated in nerve tissues, which was consistent with the activation of protein kinases. The results suggested that CaMKII might be partly (in CC but not in SC and SN) involved in HD-induced neuropathy. CaMKII and PKC might mediate the HD neurotoxicity by altering the NF phosphorylation status and PRs

  5. D+D thermonuclear fusion reactions with polarized particles

    International Nuclear Information System (INIS)

    Kozma, P.

    1986-01-01

    Polarization measurements from the 2 H(d, n) 3 He and 2 H(d, p) 3 H thermonuclear reactions at deuteron energies below 1 MeV are anayzed. Results of analysis enable to discuss the existence of 4 He excited states in the vicinity of d+d threshold energy as well as to extrapolate total cross-sections σ tot (d+d) into the region of very low energies

  6. The effect of biofiltration on red blood cells 2.3-diphosphoglycerate and pH.

    Science.gov (United States)

    Umimoto, K; Hirai, Y; Hayashi, T; Tanaka, H

    2000-12-01

    To investigate the effect of biofiltration (BF) on the ability of blood to supply oxygen to the peripheral tissues, a 2 week crossover study was conducted with bicarbonate hemodialysis (BcHD) and BF using 5 male patients with diabetic renal failure as subjects. BcHD and BF were performed for 4 h and 3.5 h per session, respectively. Blood gases, the pH of red blood cells (RBC-pH), and 2. 3-diphosphoglycerate in RBC (RBC-2.3DPG) were measured during each treatment. After a 2 week BF treatment, the plasma HCO3- at the beginning of BF was significantly higher than that of BcHD (p level (p levels. The RBC-2.3DPG during BcHD remained unchanged, but during BF significantly increased (p level. The improved metabolic acidosis might occur as a result of the increase in RBC-2.3DPG during BF. This increase in RBC-2.3DPG has the effect of reducing the affinity of oxygen for hemoglobin and allows more oxygen to be delivered to the peripheral tissues although the increase in RBC-pH by dialysis restricts the dissociation of oxygen from hemoglobin.

  7. Efforts towards a dynamically polarised HD-target

    International Nuclear Information System (INIS)

    Radtke, E.; Goertz, St.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Reicherz, G.

    2004-01-01

    The molecular hydrogen isotopes contain no unpolarisable background. From this point of view they appear to be the material of choice for a polarised bulk target in scattering experiments. The fast nuclear relaxation of H 2 and D 2 is one reason that these substances are not highly polarisable. This fact brings hydrogendeuteride (HD) into focus. In Bochum a device to freeze out gases into the consisting 4 He-cryostat has been built up. The principle of the Dynamic Nuclear Polarisation requires a sufficient amount of paramagnetic electrons. These have been produced by cracking HD molecules at 1 K using a 90 Sr β-source with an activity of 3.7 GBq. Six days of effective irradiation resulted in a density of paramagnetic centres in the order of 10 18 spins/cm 3 . This could be estimated from bolometric electron paramagnetic resonance (EPR) measurements. Dynamic polarisation could not be achieved. This is accounted to isotopic impurities in the used HD, which accelerate the nuclear relaxation. The constant of ortho-para conversion in H 2 could be confirmed to be 1.9%/h

  8. The first 3D malonate bridged copper [Cu(O2C–CH2–CO2H)2·2H2O]: Structure, properties and electronic structure

    International Nuclear Information System (INIS)

    Seguatni, A.; Fakhfakh, M.; Smiri, L.S.; Gressier, P.; Boucher, F.; Jouini, N.

    2012-01-01

    A new inorganic-organic compound [Cu(O 2 C–CH 2 –CO 2 H) 2 ·2H 2 O] ([Cumal]) was hydrothermally synthesized and characterized by IR spectroscopy, thermal analysis and single crystal X-ray diffraction. [Cumal] is the first three-dimensional compound existing in the system Cu(II)–malonic acid–H 2 O. Its framework is built up through carboxyl bridged copper where CuO 6 octahedra are elongated with an almost D 4h symmetry (4+2) due to the Jahn–Teller effect. The magnetic properties were studied by measuring its magnetic susceptibility in the temperature range of 2–300 K indicating the existence of weak ferromagnetic interactions. The electronic structure of [Cumal] was calculated within the density functional theory (DFT) framework. Structural features are well reproduced using DFT structural optimizations and the optical spectra, calculated within the dielectric formalism, explain very well the light blue colour of the compound. It is shown that a GGA+U approach with a U eff value of about 6 eV is necessary for a better correlation with the experiment. - Graphical abstract: [Cu(O 2 C–CH 2 –CO 2 H) 2 ·2H 2 O]: the first 3D hybrid organic–inorganic compound built up carboxyl groups. The network presents a diamond-like structure achieved via carboxyl. Highlights: ► A new organic–inorganic material with an unprecedented topology is synthesized. ► Crystallographic structure is determined using single crystal X-ray diffraction. ► Electronic structure is obtained from DFT, GGA+U calculation. ► Framework can be described as formed from CuC 4 tetrahedron sharing four corners. ► This structure can be classified as an extended diamond structure.

  9. Final Hazard Categorization and Auditable Safety Analysis for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2 and 118-H-3 Solid Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    T. J. Rodovsky

    2006-03-01

    This report presents the initial hazard categorization, final hazard categorization and auditable safety analysis for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site.

  10. Fusion with highly spin polarized HD and D2

    International Nuclear Information System (INIS)

    Honig, A.

    1992-01-01

    This report discusses the following topics relating to inertial confinement with spin polarized hydrogen targets: low temperature implementation of mating a target to omega; dilution-refrigerator cold-entry and retrieval system; target shell tensile strength characterization at low temperatures; and proton and deuteron spin-lattice relaxation measurements in HD in the millikelvin temperature range

  11. Detection of planet candidates around K giants. HD 40956, HD 111591, and HD 113996

    Science.gov (United States)

    Jeong, G.; Lee, B.-C.; Han, I.; Omiya, M.; Izumiura, H.; Sato, B.; Harakawa, H.; Kambe, E.; Mkrtichian, D.

    2018-02-01

    Aims: The purpose of this paper is to detect and investigate the nature of long-term radial velocity (RV) variations of K-type giants and to confirm planetary companions around the stars. Methods: We have conducted two planet search programs by precise RV measurement using the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO) and the 1.88 m telescope at Okayama Astrophysical Observatory (OAO). The BOAO program searches for planets around 55 early K giants. The OAO program is looking for 190 G-K type giants. Results: In this paper, we report the detection of long-period RV variations of three K giant stars, HD 40956, HD 111591, and HD 113996. We investigated the cause of the observed RV variations and conclude the substellar companions are most likely the cause of the RV variations. The orbital analyses yield P = 578.6 ± 3.3 d, m sin i = 2.7 ± 0.6 MJ, a = 1.4 ± 0.1 AU for HD 40956; P = 1056.4 ± 14.3 d, m sin i = 4.4 ± 0.4 MJ, a = 2.5 ± 0.1 AU for HD 111591; P = 610.2 ± 3.8 d, m sin i = 6.3 ± 1.0 MJ, a = 1.6 ± 0.1 AU for HD 113996. Based on observations made with the BOES at BOAO in Korea and HIDES at OAO in Japan.Tables 3-5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A3

  12. Fluorescence of RbH and RbD formed by irradiating the mixed gases Rb + H2 and Rb + D2 with laser light

    International Nuclear Information System (INIS)

    Kato, Hajime; Toyosaka, Yukiko; Suzuki, Tomonari

    1985-01-01

    When a mixture of 85 Rb, 85 Rb 2 , and D 2 was irradiated by laser light at 5145 or 4880 A, small visible particles appeared and the fluorescence spectra were observed. By analyzing these spectra, we determined the rotational constants B v and the centrifugal distortion constants D v and H v for the X 1 Σ + and A 1 Σ + states of 85 RbD. By considering the isotopic dependence of the Dunham coefficients, we determined various molecular constants of 85 RbH whose values were in good agreement with the observed fluorescence spectra of 85 RbH excited by laser lines at 4762, 4765, and 4880 A. The process of RbH formation is discussed. (author)

  13. Mechanism and kinetics of LiX(X=H, D, T) + H2O reaction

    International Nuclear Information System (INIS)

    Lei Hongjie; Duan Hao; Xing Pifeng; Tang Yongjian

    2011-01-01

    The reaction mechanism of LiX(X=H, D, T) with H 2 O was investigated at MP2/6-311G (d) level using ab initio quantum chemistry in Gaussian 03 software. The equilibrium geometries, harmonic frequencies and energy of various stationary points on the potential energy surfaces were calculated in the lowest singlet states. Considering the quantum correction, the reaction rate constants were calculated using classical transition state theory. The results show the reaction of LiH (LiD, LiT) with H 2 O was considerably dependent on temperature that it is lower, the reaction rate constants are smaller. (authors)

  14. Fusion with highly spin polarized HD and D2

    International Nuclear Information System (INIS)

    Honig, A.; Letzring, S.; Skupsky, S.

    1993-01-01

    The experimental efforts over the past 5 years have been aimed at carrying out ICF shots with spin-polarized D fuel. The authors successfully prepared polarized D in HD, and solved the problems of loading target shells with their carefully prepared isotopic mixtures, polarizing them so that the D polarization remains metastably frozen-in for about half a day, and carrying out the various cold transfer requirements at Syracuse, where the target is prepared, and at Rochester, where the cold target is inserted into the OMEGA fusion chamber. A principal concern during this past year was overcoming difficulties encountered in maintaining the integrity of the fragile cold target during the multitude of cold-transfers required for the experiment. These difficulties arose from insufficient rigidity of the cold transfer systems, which were constrained to be of small diameter by the narrow central access bore of the dilution refrigerator, and were exacerbated by the multitude of required target shell manipulations between different environments, each with different coupling geometry, including target shell permeation, polarization, storage, transport, retrieval and insertion into OMEGA. The authors did solve all of these problems, and were able to position a cold, high density but unpolarized target with required precision in OMEGA. Upon shooting the accurately positioned unpolarized high density cold target, no neutron yield was observed. Inspection inside the OMEGA tank after the shot indicated the absence of neutron yield was due to mal-timing or insufficient retraction rate of OMEGA's fast shroud mechanism, resulting in interception of at least 20 of the 24 laser beams by the faulty shroud. In spite of this, all elements of the complex experiment the authors originally undertook have been successfully demonstrated, and the cold retrieval concepts and methods they developed are being utilized on the ICF upgrades at Rochester and at Livermore

  15. Nuclear quantum effects on adsorption of H2 and isotopologues on metal ions

    Science.gov (United States)

    Savchenko, Ievgeniia; Gu, Bing; Heine, Thomas; Jakowski, Jacek; Garashchuk, Sophya

    2017-02-01

    The nuclear quantum effects on the zero-point energy (ZPE), influencing adsorption of H2 and isotopologues on metal ions, are examined using normal mode analysis of ab initio electronic structure results for complexes with 17 metal cations. The lightest metallic nuclei, Li and Be, are found to be the most 'quantum'. The largest selectivity in adsorption is predicted for Cu, Ni and Co ions. Analysis of the nuclear wavepacket dynamics on the ground state electronic potential energy surfaces (PES) performed for complexes of Li+ and Cu+2 with H2/D2/HD shows that the PES anharmonicity changes the ZPE by up to 9%.

  16. Trajectory Calculations for Bergman Cyclization Predict H/D Kinetic Isotope Effects Due to Nonstatistical Dynamics in the Product.

    Science.gov (United States)

    Doubleday, Charles; Boguslav, Mayla; Howell, Caronae; Korotkin, Scott D; Shaked, David

    2016-06-22

    An unusual H/D kinetic isotope effect (KIE) is described, in which isotopic selectivity arises primarily from nonstatistical dynamics in the product. In DFT-based quasiclassical trajectories of Bergman cyclization of (Z)-3-hexen-1,5-diyne (1) at 470 K, the new CC bond retains its energy, and 28% of nascent p-benzyne recrosses back to the enediyne on a vibrational time scale. The competing process of intramolecular vibrational redistribution (IVR) in p-benzyne is too slow to prevent this. Deuteration increases the rate of IVR, which decreases the fraction of recrossing and increases the yield of statistical (trapable) p-benzyne, 2. Trapable yields for three isotopomers of 2 range from 72% to 86%. The resulting KIEs for Bergman cyclization differ substantially from KIEs predicted by transition state theory, which suggests that IVR in this reaction can be studied by conventional KIEs. Leakage of vibrational zero point energy (ZPE) into the reaction coordinate was probed by trajectories in which initial ZPE in the CH/CD stretching modes was reduced by 25%. This did not change the predicted KIEs.

  17. New metal-organic frameworks of [M(C6H5O7)(C6H6O7)(C6H7O7)(H2O)] . H2O (M=La, Ce) and [Ce2(C2O4)(C6H6O7)2] . 4H2O

    International Nuclear Information System (INIS)

    Weng Shengfeng; Wang, Yun-Hsin; Lee, Chi-Shen

    2012-01-01

    Two novel materials, [M(C 6 H 5 O 7 )(C 6 H 6 O 7 )(C 6 H 7 O 7 )(H 2 O)] . H 2 O (M=La(1a), Ce(1b)) and [Ce 2 (C 2 O 4 )(C 6 H 6 O 7 ) 2 ] . 4H 2 O (2), with a metal-organic framework (MOF) were prepared with hydrothermal reactions and characterized with photoluminescence, magnetic susceptibility, thermogravimetric analysis and X-ray powder diffraction in situ. The crystal structures were determined by single-crystal X-ray diffraction. Compound 1 crystallized in triclinic space group P1-bar (No. 2); compound 2 crystallized in monoclinic space group P2 1 /c (No. 14). The structure of 1 is built from a 1D MOF, composed of deprotonated citric ligands of three kinds. Compound 2 contains a 2D MOF structure consisting of citrate and oxalate ligands; the oxalate ligand arose from the decomposition in situ of citric acid in the presence of Cu II ions. Photoluminescence spectra of compounds 1b and 2 revealed transitions between the 5d 1 excited state and two levels of the 4f 1 ground state ( 2 F 5/2 and 2 F 7/2 ). Compounds 1b and 2 containing Ce III ion exhibit a paramagnetic property with weak antiferromagnetic interactions between the two adjacent magnetic centers. - Graphical Abstract: [M(C 6 H 5 O 7 )(C 6 H 6 O 7 )(C 6 H 7 O 7 )(H 2 O)] . H 2 O (M=La(1a), Ce(1b)) and [Ce 2 (C 2 O 4 )(C 6 H 6 O 7 ) 2 ] . 4H 2 O (2)—with 1D and 2D structures were synthesized and characterized. Highlights: ► Two MOF – [M(C 6 H 5 O 7 )(C 6 H 6 O 7 )(C 6 H 7 O 7 )(H 2 O)] . H 2 O (M=La(1a), Ce(1b)) and [Ce 2 (C 2 O 4 )(C 6 H 6 O 7 ) 2 ] . 4H 2 O (2) – with 1D and 2D structures. ► The adjacent chains of the 1D framework were correlated with each other through an oxalate ligand to form a 2D layer structure. ► The source of the oxalate ligand was the decomposition in situ of citric acid oxidized in the presence of Cu II ions.

  18. How to Analyse Metal Hydride Decomposition Temperatures Using a Sieverts’ Type Hydriding-Dehydriding Apparatus and Hydrogen-Storage Characteristics for an MgH2–Based Alloy

    Directory of Open Access Journals (Sweden)

    Young Jun KWAK

    2018-02-01

    Full Text Available In this work, a method to analyze metal hydride decomposition temperatures (the onset temperature of the metal hydride decomposition and the temperature for the maximum ratio of released gas quantity change with temperature change, of prepared samples were investigated using a Sieverts’ type hydriding-dehydriding apparatus, in which a back-pressure regulator was employed. The quantity of the gas released under 1.0 bar H2 was measured as the temperature was increased with a heating rate of 4 K/min. The variation in the ratio of released hydrogen quantity Hd change with temperature T change, dHd/dT, as a function of temperature was obtained and from the variation in dHd/dT with T, the metal hydride decomposition temperatures were analyzed. This analysis method can be used instead of thermal analysis methods such as thermogravimetric analysis (TGA, differential scanning calorimetry (DSC analysis, differential thermal analysis (DTA, and thermal desorption spectroscopy (TDS analysis. For this analysis, a sample with a composition of 89 wt.% MgH2 + 4.9 wt.% Ni + 1.7 wt.% Zn(BH42 + 1.0 wt% NaCl + 1.7 wt.% Ti + 1.7 wt % Fe (named MgH2-Ni-Zn(BH42-NaCl-Ti-Fe sample was prepared by planetary ball milling. In the prepared MgH2-Ni-Zn(BH42-NaCl-Ti-Fe sample, it is believed that MgH2 begins to decompose at about 575 K and dHd/dT reaches its peak at about 610 K.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17664

  19. New determination of the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reaction rates at astrophysical energies

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A.; Spartà, R.; Spitaleri, C.; Pizzone, R. G.; La Cognata, M.; Rapisarda, G. G.; Romano, S.; Sergi, M. L. [Laboratori Nazionali del Sud-INFN, Catania (Italy); Mukhamedzhanov, A. M. [Cyclotron Institute Texas A and M University-College Station, Texas (United States); Typel, S. [GSI Helmholtzzentrum für Schwerionenforschung GmbH-Theorie Darmstadt (Germany); Tognelli, E.; Degl' Innocenti, S.; Prada Moroni, P. G. [Dipartimento di Fisica, Università di Pisa, and INFN-Sezione di Pisa, Pisa (Italy); Burjan, V.; Kroha, V.; Hons, Z.; Mrazek, J.; Piskor, S. [Nuclear Physics Institute of ASCR-Rez near Prague (Czech Republic); Lamia, L., E-mail: tumino@lns.infn.it [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Catania (Italy)

    2014-04-20

    The cross sections of the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions have been measured via the Trojan Horse method applied to the quasi-free {sup 2}H({sup 3}He,p {sup 3}H){sup 1}H and {sup 2}H({sup 3}He,n {sup 3}He){sup 1}H processes at 18 MeV off the proton in {sup 3}He. For the first time, the bare nucleus S(E) factors have been determined from 1.5 MeV, across the relevant region for standard Big Bang nucleosynthesis, down to the thermal energies of deuterium burning in the pre-main-sequence (PMS) phase of stellar evolution, as well as of future fusion reactors. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from the available direct data and existing fitting curves, with substantial variations in the electron screening by more than 50%. As a consequence, the reaction rates for astrophysics experience relevant changes, with a maximum increase of up to 20% at the temperatures of the PMS phase. From a recent primordial abundance sensitivity study, it turns out that the {sup 2}H(d,n){sup 3}He reaction is quite influential on {sup 7}Li, and the present change in the reaction rate leads to a decrease in its abundance by up to 10%. The present reaction rates have also been included in an updated version of the FRANEC evolutionary code to analyze their influence on the central deuterium abundance in PMS stars with different masses. The largest variation of about 10%-15% pertains to young stars (≤1 Myr) with masses ≥1 M {sub ☉}.

  20. Tritiated-water detection with a 2D(γ,n)1H monitor

    International Nuclear Information System (INIS)

    Winn, W.G.; Baumann, N.P.

    Tritiated process water is monitored by detecting the D 2 O component via the 2 D(γ,n) 1 H reaction. A probe containing a 1 to 7 mCi 24 Na (15 h) γ-source and six 3 He neutron detectors produces and monitors the 2 D(γ,n) 1 H reaction. A variety of probe configurations were examined for D 2 O detection sensitivity. The corresponding detection limits range from 6 to 280 μL for D 2 O droplets and 1 to 13 μL/cm for D 2 O streams, when 10-minute neutron counting with a 1 mCi γ-source is used. Results from two field applications illustrate the utility of the monitor

  1. Sc2C2@D3h(14246)-C74: A Missing Piece of the Clusterfullerene Puzzle.

    Science.gov (United States)

    Wang, Yaofeng; Tang, Qiangqiang; Feng, Lai; Chen, Ning

    2017-02-20

    Clusterfullerenes with variable carbon cages have been extensively studied in recent years. However, despite all these efforts, C 74 cage-based clusterfullerene remains a missing piece of the puzzle. Herein, we show that single-crystal X-ray crystallographic analysis unambiguously assigns the previously reported dimetallofullerene Sc 2 @C 76 to a novel carbide clusterfullerene, Sc 2 C 2 @D 3h (14246)-C 74 , the first experimentally proven clusterfullerene with a C 74 cage. In addition, Sc 2 C 2 @D 3h (14246)-C 74 was charaterized by mass spectrometry, ultraviolet-visible-near-infrared absorption spectroscopy, 45 Sc nuclear magnetic resonance, and cyclic voltammetry. Comparative studies of the motion of the carbide cluster in Sc 2 C 2 @D 3h (14246)-C 74 and Sc 2 C 2 @C 2n (n = 40-44) revealed that a combination of factors, involving both the shape and size of the cage, is crucial in dictating the cluster motion. Moreover, structural studies of D 3h (14246)-C 74 revealed that it can be easily converted to C s (10528)-C 72 and T d (19151)-C 76 cages via C 2 desertion/insertion and Stone-Wales transformation. This suggests that D 3h (14246)-C 74 might play an important role in the growth pathway of clusterfullerenes.

  2. Magnetism of CuCl{sub 22D{sub 2}O and CuCl{sub 22H{sub 2}O, and of CuBr{sub 2}·6H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    DeFotis, G.C., E-mail: gxdefo@wm.edu [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hampton, A.S.; Van Dongen, M.J.; Komatsu, C.H.; Benday, N.S.; Davis, C.M. [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Hays, K.; Wagner, M.J. [Department of Chemistry, George Washington University, Washington, D.C. 20052 (United States)

    2017-07-15

    Highlights: • CuCl{sub 22D{sub 2}O is examined magnetically and compared with CuCl{sub 22H{sub 2}O. • Slightly lower magnetic characteristic temperatures occur for deuterated dihydrate. • The new compound CuBr{sub 2}·6H{sub 2}O is examined magnetically. • Unexpected relationships appears between magnetic behaviors of CuBr{sub 2}·6H{sub 2}O and CuBr{sub 2}. • Two alternative monoclinic unit cells can account for diffraction data on CuBr{sub 2}·6H{sub 2}O. - Abstract: The magnetic properties of little examined CuCl{sub 22D{sub 2}O are studied and compared with those of CuCl{sub 22H{sub 2}O. New CuBr{sub 2}·6H{sub 2}O is also examined. Susceptibility maxima appear for chlorides at 5.35 and 5.50 K, in the above order, with estimated antiferromagnetic ordering at 4.15 and 4.25 K. Curie-Weiss fits yield g of 2.210 and 2.205, and Weiss θ of −6.0 and −4.7 K, respectively, in χ{sub M} = C/(T − θ). One-dimensional Heisenberg model fits to susceptibilities, including interchain exchange in a mean-field approximation, are performed. Interchain exchange is significant but much weaker than intrachain. The bromide hexahydrate strongly differs magnetically from any chloride hydrate, but exhibits notable similarities and differences compared to previously studied CuBr{sub 2}. A broad susceptibility maximum occurs near 218 K, only 4% lower than for CuBr{sub 2}, but with almost twice the magnitude. Powder X-ray diffraction data for CuBr{sub 2}·6H{sub 2}O may be best accounted for by a monoclinic unit cell that is metrically orthorhombic. The volume per formula unit is consistent with trends in metal ionic radii. However, an alternative monoclinic cell with 5% smaller volume more readily rationalizes the magnetism.

  3. An accurate potential energy surface for the F + H2 → HF + H reaction by the coupled-cluster method

    International Nuclear Information System (INIS)

    Chen, Jun; Sun, Zhigang; Zhang, Dong H.

    2015-01-01

    A three dimensional potential energy surface for the F + H 2 → HF + H reaction has been computed by the spin unrestricted coupled cluster method with singles, doubles, triples, and perturbative quadruples [UCCSDT(2) Q ] using the augmented correlation-consistent polarised valence quadruple zeta basis set for the fluorine atom and the correlation-consistent polarised valence quadruple zeta basis set for the hydrogen atom. All the calculations are based on the restricted open-shell Hartree-Fock orbitals, together with the frozen core approximations, and the UCCSD(T)/complete basis set (CBS) correction term was included. The global potential energy surface was calculated by fitting the sampled ab initio points without any scaling factor for the correlation energy part using a neutral network function method. Extensive dynamics calculations have been carried out on the potential energy surface. The reaction rate constants, integral cross sections, product rotational states distribution, and forward and backward scattering as a function of collision energy of the F + HD → HF + D, F + HD → DF + H, and F + H 2 reaction, were calculated by the time-independent quantum dynamics scattering theory using the new surface. The satisfactory agreement with the reported experimental observations previously demonstrates the accuracy of the new potential energy surface

  4. /sup 1/H NMR study of 2-deoxy-D-arabino-hexopyranose (2-deoxy-glucopyranose), 2-deoxy-D-lyxo-hexopyranose (2-deoxy-galactopyranose) and 2'-deoxy lactose. Shift increment studies in 2-deoxy carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    de Bruyn, A; Anteunis, M [Ghent Rijksuniversiteit (Belgium)

    1975-01-01

    Complete analyses are given of the /sup 1/H n.m.r. spectra at 300 MHz of D/sub 2/O solutions of 2-deoxy-D-arabino-hexopyranose, 2-deoxy-D-lyxo-hexopyranose and 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose are compared with those previously obtained in the parent aldeohexopyranoses, glucobioses and D-galactopyranosol-D-glucoses. Increment values are suggested in order to predict chemical shifts in 2-deoxy derivatives from the well known rules for aldohexopyranoses.

  5. Laser-driven polarized H/D sources and targets

    International Nuclear Information System (INIS)

    Clasie, B.; Crawford, C.; Dutta, D.; Gao, H.; Seely, J.; Xu, W.

    2005-01-01

    Traditionally, Atomic Beam Sources are used to produce targets of nuclear polarized hydrogen (H) or deuterium (D) for experiments using storage rings. Laser-Driven Sources (LDSs) offer a factor of 20-30 gain in the target thickness (however, with lower polarization) and may produce a higher overall figure of merit. The LDS is based on the technique of spin-exchange optical pumping where alkali vapor is polarized by absorbing circularly polarized laser photons. The H or D atoms are nuclear-polarized through spin-exchange collisions with the polarized alkali vapor and through subsequent hyperfine interactions during frequent H-H or D-D collisions

  6. Impact of Different H/D Ratio on Axial Gas Holdup Measured by Four-Tips Optical Fiber Probe in Slurry Bubble Column

    Directory of Open Access Journals (Sweden)

    Yasser Imad Abdulaziz

    2016-02-01

    Full Text Available In wide range of chemical, petrochemical and energy processes, it is not possible to manage without slurry bubble column reactors. In this investigation, time average local gas holdup was recorded for three different height to diameter (H/D ratios 3, 4 and 5 in 18" diameter slurry bubble column. Air-water-glass beads system was used with superficial velocity up to 0.24 m/s. the gas holdup was measured using 4-tips optical fiber probe technique. The results show that the axial gas holdup increases almost linearly with the superficial gas velocity in 0.08 m/s and levels off with a further increase of velocity. A comparison of the present data with those reported for other slurry bubble column having diameters larger than 18" and H/D higher than 5 indicated that there is little effect of diameter on gas holdup. Also, local section-average gas holdups increase with increasing superficial gas velocity, while the effect of solid loading are less significant than that of superficial gas velocity.

  7. Hanging drop: an in vitro air toxic exposure model using human lung cells in 2D and 3D structures.

    Science.gov (United States)

    Liu, Faye F; Peng, Cheng; Escher, Beate I; Fantino, Emmanuelle; Giles, Cindy; Were, Stephen; Duffy, Lesley; Ng, Jack C

    2013-10-15

    Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX(®) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50cell for 1h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kgdry weight, which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Barrier widths, barrier heights, and the origins of anomalous kinetic H/D isotope effects

    International Nuclear Information System (INIS)

    Wolfe, S.; Hoz, Shmaryahu; Kim, Chankyung; Yang, Kiyull

    1990-01-01

    Proton transfer between MeO - and HOMe has been studied using ab initio molecular orbital theory. At the highest level employed (MP2/6-31+G(d)//6-31G(d)+ZPE), -ΔH 298 and -ΔG 298 for the formation of the ion-molecule complex MeO - hor-ellipsis HOMe from the separated reactants are 26.3 and 15.2 kcal/mol, respectively. At the 6-31G(d)//6-31G(d) level of theory, the (MeO-H-OMe) - transition structure is 2.19 kcal/mol higher in energy than the ion-molecule complex (ΔE double-dagger = 2.19), but this barrier disappears when zero-point energies are taken into account. The performance of AM1 on this system is quantitatively different (-ΔH 298 = 13.3; -ΔG 298 = 6.9; ΔE double-dagger = 4.91; k H /k D = 5.13, increasing to 5.79 when quantum mechanical tunneling is invoked) but appears to be acceptable for the research envisaged in the title. The effect of an enforced separation of the heavy atoms upon proton transfer barriers and isotope effects (which simulates steric effects) has been studied briefly at the 6-31G(d) level and in some detail using AM1

  9. Electrochemical behaviour of cadmium in the H{sub 2}O-D{sub 2}O system. I. Polarographic study

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Lopez, J

    1966-07-01

    The diffusion current of Cd{sup 2} in a H{sub 2}O-D{sub 2}O system with a supporting electrolyte of 0.1 M KC1 + 0.01 M HC1 has been studied as a function of parameters such as time, height of the mercury reservoir and electrolyte temperature. the characteristics of the process are those of a reversible diffusion-controlled process. In the H{sub 2}O-D{sub 2}O system, the values of the diffusion current were smaller than the corresponding ones in H{sub 2}O, at 25 degree centigrade. The decrease was proportional to D{sub 2}O concentration when this was greater than 35 per cent. This fact may be used as an analytical means of determining D{sub 2}O in H{sub 2}O mixtures. (Author) 7 refs.

  10. An accurate potential energy surface for the F + H{sub 2} → HF + H reaction by the coupled-cluster method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jun; Sun, Zhigang, E-mail: zsun@dicp.ac.cn, E-mail: zhangdh@dicp.ac.cn; Zhang, Dong H., E-mail: zsun@dicp.ac.cn, E-mail: zhangdh@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2015-01-14

    A three dimensional potential energy surface for the F + H{sub 2} → HF + H reaction has been computed by the spin unrestricted coupled cluster method with singles, doubles, triples, and perturbative quadruples [UCCSDT(2){sub Q}] using the augmented correlation-consistent polarised valence quadruple zeta basis set for the fluorine atom and the correlation-consistent polarised valence quadruple zeta basis set for the hydrogen atom. All the calculations are based on the restricted open-shell Hartree-Fock orbitals, together with the frozen core approximations, and the UCCSD(T)/complete basis set (CBS) correction term was included. The global potential energy surface was calculated by fitting the sampled ab initio points without any scaling factor for the correlation energy part using a neutral network function method. Extensive dynamics calculations have been carried out on the potential energy surface. The reaction rate constants, integral cross sections, product rotational states distribution, and forward and backward scattering as a function of collision energy of the F + HD → HF + D, F + HD → DF + H, and F + H{sub 2} reaction, were calculated by the time-independent quantum dynamics scattering theory using the new surface. The satisfactory agreement with the reported experimental observations previously demonstrates the accuracy of the new potential energy surface.

  11. Achievement of transportable polarized D, in solid HD, with a one day passively maintained polarization

    International Nuclear Information System (INIS)

    Honig, A.; Alexander, N.; Fan, Q.; Wei, X.; Yu, Y.Y.

    1993-01-01

    At a previous workshop, we discussed evaporating solid HD with spin-polarized deuterons to produce a high density polarized deuteron gaseous internal target. Since then, we have achieved in solid HD 38% polarized D, whose spin-lattice relaxation time at 1.5 K in a field of 0.1 T is of the order of a day. Optimization of the procedure with the present apparatus should result in 60% D polarization, and longer polarization holding times. The polarized sample of approximately 0.2 cm 3 volume used here is extractable from the dilution refrigerator with a cold-transfer apparatus which maintains the sample at or below 5 K, insuring retention of the high polarization. It is subsequently insertable into a variety of systems, and employable as a polarized solid, liquid, or gas. We are exploring the possibility of extending the polarization maintenance time to about a month (with a matched 1 month preparation time), of polarizing metastably H as well as D, and of producing much larger samples, of the order of 100 cm 3

  12. Variations of brightness and Ca 2 emission of the xi Boo AB and HD 1835 dWarf G stars

    Energy Technology Data Exchange (ETDEWEB)

    Chuganov, P.F.

    1983-01-01

    75 photoelectric UBV-observations of xi Boo AB were obtained during 45 nights in 1980. Real light variations of several thousandths of magnitude are revealed. Moreover, the variations observed in two nights were resembling flares. Both recent and published data on HD 1835 together with Wilson's observations of H and K Ca II lines in the spectra of xi Boo A, xi Boo B and HD 1835 are used for the search of periodicities. The periodicities are present in variations of light and Ca II -emission. Periodicities are more prominent in light variations (periods are 10 days for xi Boo AB and 7.66 days for HD 1835). In H and K Ca II lines the duration of cycles is different but the basic period is the same as in light variations. Therefore, the basic period (interpreted as the period of star roration) can be revealed only from a very long run of H and K Ca II observations (approximately 150). Light variations of xi Boo AB are probably due to the A-component since the basic period of Ca II-variations in xi Boo A is approximately the same (10 days). The basic period of Ca II-variations in xi Boo B is considerably larger.

  13. Variations of brightness and Ca 2 emission of the xi Boo AB and HD 1835 dWarf G stars

    International Nuclear Information System (INIS)

    Chuganov, P.F.

    1983-01-01

    75 photoelectric UBV-observations of xi Boo AB were obtained during 45 nights in 1980. Real light variations of several thousandths of magnitude are revealed. Moreover, the variations observed in two nights were resembling flares. Both recent and published data on HD 1835 together with Wilson's observations of H and K Ca II lines in the spectra of xi Boo A, xi Boo B and HD 1835 are used for the search of periodicities. The periodicities are present in variations of light and Ca II -emission. Periodicities are more prominent in light variations (periods are 10 days for xi Boo AB and 7.66 days for HD 1835). In H and K Ca II lines the dura-- tion of cycles is different but the basic period is the same as in light variations. Therefore, the basic period (interpreted as the period of star roration) can be revealed only from a very long run of H and K Ca II observations (approximately 150). Light variations of xi Boo AB are probably due to the A-component since the basic period of Ca II-variations in xi Boo A is approximately the same (10 days). The basic period of Ca II-variations in xi Boo B is considerably larger;

  14. A novel bioactive haemodialysis system using dissolved dihydrogen (H2) produced by water electrolysis: a clinical trial.

    Science.gov (United States)

    Nakayama, Masaaki; Nakano, Hirofumi; Hamada, Hiromi; Itami, Noritomo; Nakazawa, Ryoichi; Ito, Sadayoshi

    2010-09-01

    Chronic inflammation in haemodialysis (HD) patients indicates a poor prognosis. However, therapeutic approaches are limited. Hydrogen gas (H(2)) ameliorates oxidative and inflammatory injuries to organs in animal models. We developed an HD system using a dialysis solution with high levels of dissolved H(2) and examined the clinical effects. Dialysis solution with H(2) (average of 48 ppb) was produced by mixing dialysate concentrates and reverse osmosis water containing dissolved H(2) generated by a water electrolysis technique. Subjects comprised 21 stable patients on standard HD who were switched to the test HD for 6 months at three sessions a week. During the study period, no adverse clinical signs or symptoms were observed. A significant decrease in systolic blood pressure (SBP) before and after dialysis was observed during the study, and a significant number of patients achieved SBP <140 mmHg after HD (baseline, 21%; 6 months, 62%; P < 0.05). Changes in dialysis parameters were minimal, while significant decreases in levels of plasma monocyte chemoattractant protein 1 (P < 0.01) and myeloperoxidase (P < 0.05) were identified. Adding H(2) to haemodialysis solutions ameliorated inflammatory reactions and improved BP control. This system could offer a novel therapeutic option for control of uraemia.

  15. Nuclear quantum effects on adsorption of H_2 and isotopologues on metal ions

    International Nuclear Information System (INIS)

    Savchenko, Ievgeniia; Gu, Bing; Heine, Thomas; Jakowski, Jacek; Garashchuk, Sophya

    2017-01-01

    The nuclear quantum effects on the zero-point energy (ZPE), influencing adsorption of H_2 and isotopologues on metal ions, are examined in this study using normal mode analysis of ab initio electronic structure results for complexes with 17 metal cations. To estimate for the anharmonicity, a nuclear wavepacket dynamics on the ground state electronic potential energy surfaces (PES) have been employed for complexes of Li"+ and Cu"+"2 with H_2, D_2, HD. The dynamics analysis shows that incorporation of the PES anharmonicity changes the ZPE by up to 9%. Finally, the lightest metallic nuclei, Li and Be, are found to be the most 'quantum'. The largest selectivity in adsorption is predicted for Cu, Ni and Co ions.

  16. Nanoporous materials for hydrogen storage and H2/D2 isotope separation

    International Nuclear Information System (INIS)

    Oh, Hyunchul

    2014-01-01

    This thesis presents a study of hydrogen adsorption properties at RT with noble metal doped porous materials and an efficient separation of hydrogen isotopes with nanoporous materials. Most analysis is performed via thermal desorption spectra (TDS) and Sieverts-type apparatus. The result and discussion is presented in two parts; Chapter 4 focuses on metal doped nanoporous materials for hydrogen storage. Cryogenic hydrogen storage by physisorption on porous materials has the advantage of high reversibility and fast refuelling times with low heat evolution at modest pressures. At room temperature, however, the physisorption mechanism is not abEle to achieve enough capacity for practical application due to the weak van der Waals interaction, i.e., low isosteric heats for hydrogen sorption. Recently, the ''spillover'' effect has been proposed by R. Yang et al. to enhance the room temperature hydrogen storage capacity. However, the mechanism of this storage enhancement by decoration of noble metal particles inside high surface area supports is not yet fully understood and still under debate. In this chapter, noble metal (Pt / Pd) doped nanoporous materials (i.e. porous carbon, COFs) have been investigated for room temperature hydrogen storage. Their textural properties and hydrogen storage capacity are characterized by various analytic techniques (e.g. SEM, HRTEM, XRD, BET, ICP-OES, Thermal desorption spectra, Sievert's apparatus and Raman spectroscopy). Firstly, Pt-doped and un-doped templated carbons possessing almost identical textural properties were successfully synthesized via a single step wet impregnation method. This enables the study of Pt catalytic activities and hydrogen adsorption kinetics on porous carbons at ambient temperature by TDS after H 2 /D 2 gas exposure and PCT measurement, respectively. While the H 2 adsorption kinetics in the microporous structure is enhanced by Pt catalytic activities (spillover), only a small enhancement of the hydrogen

  17. Effects of substituting D2O for H2O on SANS measurements of hydrating cement

    International Nuclear Information System (INIS)

    Sabine, T.M.; Prior, M.J.

    2002-01-01

    Full text: Small angle neutron scattering (SANS) measurements of cement have been found useful in the investigation of the shape and growth of particles formed during hydration. Calorimetric measurements of hydrating cement samples have shown that the substitution of D 2 O for H 2 O has the effect of slowing the hydration process. In order to throw some light on this phenomenon, we have measured SANS profiles from cement samples hydrating in H 2 O and D 2 O. This involved obtaining SANS profiles at half-hourly intervals during the initial stage of hydration. The only instruments capable of this at present are located at the Hahn-Meitner Institute in Berlin and at the Nuclear Physics Institute at Rez near Prague. Initial experiments carried out on the V12a UltraSANS diffractometer at The Hahn-Meitner Institute were only partially successful owing to excessive multiple scattering in the D 2 O samples. Subsequent measurements were therefore carried out on the similar instrument at Rez near Prague which operates at a shorter neutron wavelength. Results from these measurements show profound differences in the evolution of cements hydrating in D 2 O and those hydrating in H 2 O

  18. revealing H{sub 2}D{sup +} depletion and compact structure in starless and protostellar cores with ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, R. K. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto, ON M5S 3H4 (Canada); Di Francesco, J. [National Research Council Canada, Radio Astronomy Program, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Bourke, T. L. [Radio and Geoastronomy Division, Harvard Smithsonian Center for Astrophysics, MS-42, Cambridge, MA 02138 (United States); Caselli, P. [Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, D-85748 Garching (Germany); Jørgensen, J. K. [Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø. (Denmark); Pineda, J. E. [Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, CH-8093 Zürich (Switzerland); Wong, M., E-mail: friesen@dunlap.utoronto.ca [University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)

    2014-12-10

    We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the submillimeter dust continuum and H{sub 2}D{sup +} 1{sub 10}-1{sub 11} emission toward two evolved, potentially protostellar cores within the Ophiuchus molecular cloud, Oph A SM1 and SM1N. The data reveal small-scale condensations within both cores, with mass upper limits of M ≲ 0.02 M {sub ☉} (∼20 M {sub Jup}). The SM1 condensation is consistent with a nearly symmetric Gaussian source with a width of only 37 AU. The SM1N condensation is elongated and extends 500 AU along its major axis. No evidence for substructure is seen in either source. A Jeans analysis indicates that these sources are unlikely to fragment, suggesting that both will form single stars. H{sub 2}D{sup +} is only detected toward SM1N, offset from the continuum peak by ∼150-200 AU. This offset may be due to either heating from an undetected, young, low-luminosity protostellar source or first hydrostatic core, or HD (and consequently H{sub 2}D{sup +}) depletion in the cold center of the condensation. We propose that SM1 is protostellar and that the condensation detected by ALMA is a warm (T ∼ 30-50 K) accretion disk. The less concentrated emission of the SM1N condensation suggests that it is still starless, but we cannot rule out the presence of a low-luminosity source, perhaps surrounded by a pseudodisk. These data observationally reveal the earliest stages of the formation of circumstellar accretion regions and agree with theoretical predictions that disk formation can occur very early in the star formation process, coeval with or just after the formation of a first hydrostatic core or protostar.

  19. Homogeneous catalysis of deuterium transfer by potassium hydroxide and potassium methoxide D2-H2O and D2-CH3OH exchange

    International Nuclear Information System (INIS)

    Strathdee, G.G.; Garner, D.M.; Given, R.M.

    1977-01-01

    The kinetics and mechanism of exchange of deuterium between D 2 and water and between D 2 and methanol, catalyzed respectively by concentrated potassium hydroxide and potassium methoxide, has been studied between 348 and 398 K. In the D 2 -KOH-H 2 O case, the transfer of deuterium was found to be controlled by the rate of activation of the D 2 molecule by OH - . Rapid exchange of D + with the aqueous solution followed. From the D 2 -KOCH 3 -CH 3 OH studies, it was concluded that deuterium exchange depended upon the rates of both D 2 activation by methoxide and interaction of the solvent with the transition, or encounter, complex. The dependence of second-order rate constants on solvent activity for both systems was determined by normalization of the exchange reaction rates to unit reagent activity. Analysis of the kinetic isotope effects for each system suggested that their increase with base concentration or temperature was due to solvation effects. (author)

  20. Structure of LaH(PO3H)2.3H2O

    International Nuclear Information System (INIS)

    Loukili, M.; Durand, J.; Larbot, A.; Cot, L.; Rafiq, M.

    1991-01-01

    Lanthanum hydrogen bis(hydrogenphosphite) trihydrate, LaH(Po 3 H) 2 .3H 2 O, M r =353.8, monoclinic, P2 1 /c, a=9.687 (3), b=7.138 (2), c=13.518 A, β=104.48 (3) deg, V=905.0 (5) A 3 , Z=4, D m =2.56 (2), D x =2.598 Mg m -3 , λ(MoKα)=0.71073 A, μ(MoKα)=5.103 mm -1 , F(000)=672, T=300 K, R=0.032 for 1018 independent observed reflections. The structure contains two phosphite anions connected by a hydrogen bond. The La 3+ cation is eight coordinated by seven O atoms from phosphite anions and one O atom of a water molecule. (orig.)

  1. The first 3D malonate bridged copper [Cu(O{sub 2}C-CH{sub 2}-CO{sub 2}H){sub 2}{center_dot}2H{sub 2}O]: Structure, properties and electronic structure

    Energy Technology Data Exchange (ETDEWEB)

    Seguatni, A., E-mail: seguatni@gmail.com [LBPC-INSERM U 698, Institut Galilee, Universite Paris XIII, 99, avenue J. B. Clement 93430, Villetaneuse (France); Fakhfakh, M. [Unite de recherche UR 12-30, Synthese et Structure de Materiaux Inorganiques, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Departement de Chimie, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-ville, Montreal, Que., H3C 3P8 (Canada); Smiri, L.S. [Unite de recherche UR 12-30, Synthese et Structure de Materiaux Inorganiques, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Gressier, P.; Boucher, F. [Institut des Materiaux Jean Rouxel, Universite de Nantes, CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3 (France); Jouini, N. [Departement de Chimie, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-ville, Montreal, Que., H3C 3P8 (Canada)

    2012-03-15

    A new inorganic-organic compound [Cu(O{sub 2}C-CH{sub 2}-CO{sub 2}H){sub 2}{center_dot}2H{sub 2}O] ([Cumal]) was hydrothermally synthesized and characterized by IR spectroscopy, thermal analysis and single crystal X-ray diffraction. [Cumal] is the first three-dimensional compound existing in the system Cu(II)-malonic acid-H{sub 2}O. Its framework is built up through carboxyl bridged copper where CuO{sub 6} octahedra are elongated with an almost D{sub 4h} symmetry (4+2) due to the Jahn-Teller effect. The magnetic properties were studied by measuring its magnetic susceptibility in the temperature range of 2-300 K indicating the existence of weak ferromagnetic interactions. The electronic structure of [Cumal] was calculated within the density functional theory (DFT) framework. Structural features are well reproduced using DFT structural optimizations and the optical spectra, calculated within the dielectric formalism, explain very well the light blue colour of the compound. It is shown that a GGA+U approach with a U{sub eff} value of about 6 eV is necessary for a better correlation with the experiment. - Graphical abstract: [Cu(O{sub 2}C-CH{sub 2}-CO{sub 2}H){sub 2}{center_dot}2H{sub 2}O]: the first 3D hybrid organic-inorganic compound built up carboxyl groups. The network presents a diamond-like structure achieved via carboxyl. Highlights: Black-Right-Pointing-Pointer A new organic-inorganic material with an unprecedented topology is synthesized. Black-Right-Pointing-Pointer Crystallographic structure is determined using single crystal X-ray diffraction. Black-Right-Pointing-Pointer Electronic structure is obtained from DFT, GGA+U calculation. Black-Right-Pointing-Pointer Framework can be described as formed from CuC{sub 4} tetrahedron sharing four corners. Black-Right-Pointing-Pointer This structure can be classified as an extended diamond structure.

  2. Bulk Soil Organic Matter d2H as a Precipitation Proxy

    Science.gov (United States)

    Williams, E. K.; Terwilliger, V. J.; Nakamoto, B. J.; Berhe, A. A.; Fogel, M. L.

    2016-12-01

    The stable hydrogen isotopic composition (d2H) of leaf waxes have traditionally been used to infer modern and paleoclimate precipitation sources. However, the extent to which evapotranspiration of leaf waters affects the d2H of plant leaf waxes remains hotly contested with offsets varying between species. Because of the relative importance of root organic matter contribution to bulk soil pools compared to litter/leaves and the minimal fractionation between soil water and root material, it is plausible that bulk soil organic matter d2H may be an option for modern and paleoclimate precipitation reconstructions. In this study, we analyzed the non-exchangeable d2H composition of roots, litter, leaves, and bulk soils along an elevation gradient in the southern Sierra Nevada range (USA). Our results show a consistent offset of 30 ± 3‰ in bulk soil organic matter in surface soils from the measured precipitation. This consistent relationship with precipitation was not found in any of the other organic materials that we measured and implies that d2H bulk soil organic matter can record precipitation signals regardless of above-ground species composition. Additionally, we utilized physical density fractionation to determine which fractions (which vary in level of mineral association and in turnover time) of the soil control this relationship. These findings and how this relationship holds with depth will be presented in conjunction with data from a soil profile on the Ethiopian plateau spanning 6000 years.

  3. Complete active space second order perturbation theory (CASPT2) study of N({sup 2}D) + H{sub 2}O reaction paths on D{sub 1} and D{sub 0} potential energy surfaces: Direct and roaming pathways

    Energy Technology Data Exchange (ETDEWEB)

    Isegawa, Miho; Liu, Fengyi [Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Kyoto 606-8103 (Japan); Maeda, Satoshi [Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Morokuma, Keiji, E-mail: morokuma@fukui.kyoto-u.ac.jp [Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Kyoto 606-8103 (Japan); Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

    2014-10-21

    We report reaction paths starting from N({sup 2}D) + H{sub 2}O for doublet spin states, D{sub 0} and D{sub 1}. The potential energy surfaces are explored in an automated fashion using the global reaction route mapping strategy. The critical points and reaction paths have been fully optimized at the complete active space second order perturbation theory level taking all valence electrons in the active space. In addition to direct dissociation pathways that would be dominant, three roaming processes, two roaming dissociation, and one roaming isomerization: (1) H{sub 2}ON → H–O(H)N → H–HON → NO({sup 2}Π) + H{sub 2}, (2) cis-HNOH → HNO–H → H–HNO → NO + H{sub 2}, (3) H{sub 2}NO → H–HNO → HNO–H → trans-HNOH, are confirmed on the D{sub 0} surface.

  4. Experimental and theoretical study of rotationally inelastic diffraction of H2(D2) from methyl-terminated Si(111)

    International Nuclear Information System (INIS)

    Nihill, Kevin J.; Hund, Zachary M.; Sibener, S. J.; Muzas, Alberto; Cueto, Marcos del; Díaz, Cristina; Frankcombe, Terry; Plymale, Noah T.; Lewis, Nathan S.; Martín, Fernando

    2016-01-01

    Fundamental details concerning the interaction between H 2 and CH 3 –Si(111) have been elucidated by the combination of diffractive scattering experiments and electronic structure and scattering calculations. Rotationally inelastic diffraction (RID) of H 2 and D 2 from this model hydrocarbon-decorated semiconductor interface has been confirmed for the first time via both time-of-flight and diffraction measurements, with modest j = 0 → 2 RID intensities for H 2 compared to the strong RID features observed for D 2 over a large range of kinematic scattering conditions along two high-symmetry azimuthal directions. The Debye-Waller model was applied to the thermal attenuation of diffraction peaks, allowing for precise determination of the RID probabilities by accounting for incoherent motion of the CH 3 –Si(111) surface atoms. The probabilities of rotationally inelastic diffraction of H 2 and D 2 have been quantitatively evaluated as a function of beam energy and scattering angle, and have been compared with complementary electronic structure and scattering calculations to provide insight into the interaction potential between H 2 (D 2 ) and hence the surface charge density distribution. Specifically, a six-dimensional potential energy surface (PES), describing the electronic structure of the H 2 (D 2 )/CH 3 −Si(111) system, has been computed based on interpolation of density functional theory energies. Quantum and classical dynamics simulations have allowed for an assessment of the accuracy of the PES, and subsequently for identification of the features of the PES that serve as classical turning points. A close scrutiny of the PES reveals the highly anisotropic character of the interaction potential at these turning points. This combination of experiment and theory provides new and important details about the interaction of H 2 with a hybrid organic-semiconductor interface, which can be used to further investigate energy flow in technologically relevant systems.

  5. Time-resolved investigations of the fragmentation dynamic of H{sub 2} (D{sub 2}) in and with ultra-short laser pulses; Zeitaufgeloeste Untersuchungen zur Fragmentationsdynamik von H{sub 2} (D{sub 2}) in ultra-kurzen Laserpulsen

    Energy Technology Data Exchange (ETDEWEB)

    Ergler, T.

    2006-07-19

    In course of this work pump-probe experiments aimed to study ultrafast nuclear motion in H{sub 2} (D{sub 2}) fragmentation by intense 6-25 fs laser pulses have been carried out. In order to perform time-resolved measurements, a Mach-Zehnder interferometer providing two identical synchronized laser pulses with the time-delay variable from 0 to 3000 fs with 300 as accuracy and long-term stability has been built. The laser pulses at the intensities of up to 10{sup 15} W/cm{sup 2} were focused onto a H{sub 2} (D{sub 2}) molecular beam leading to the ionization or dissociation of the molecules, and the momenta of all charged reactions fragments were measured with a reaction microscope. With 6-7 fs pulses it was possible to probe the time evolution of the bound H{sup +}{sub 2} (D{sup +}{sub 2}) nuclear wave packet created by the first (pump) laser pulse, fragmenting the molecule with the second (probe) pulse. A fast delocalization, or ''collapse'', and subsequent ''revival'' of the vibrational wave packet have been observed. In addition, the signatures of the ground state vibrational excitation in neutral D{sub 2} molecule have been found, and the dominance of a new, purely quantum mechanical wave packet preparation mechanism (the so-called ''Lochfrass'') has been proved. In the experiments with 25 fs pulses the theoretically predicted enhancement of the ionization probability for the dissociating H{sup +}{sub 2} molecular ion at large internuclear distances has been detected for the first time. (orig.)

  6. [H2en]2{La2M(SO4)6(H2O)2} (M=Co, Ni): First organically templated 3d-4f mixed metal sulfates

    International Nuclear Information System (INIS)

    Yuan Yanping; Wang Ruiyao; Kong Deyuan; Mao Jianggao; Clearfield, Abraham

    2005-01-01

    The first organically templated 3d-4f mixed metal sulfates, [H 2 en] 2 {La 2 M(SO 4 ) 6 (H 2 O) 2 } (M=Co 1, Ni 2) have been synthesized and structurally determined from non-merohedrally twinned crystals. The two compounds are isostructural and their structures feature a three-dimensional anionic network formed by the lanthanum(III) and nickel(II) ions bridged by sulfate anions. The La(III) ions in both compounds are 10-coordinated by four sulfate anions in bidentate chelating fashion, and two sulfate anions in a unidentate fashion. The transition metal(II) ion is octahedrally coordinated by six oxygens from four sulfate anions and two aqua ligands. The doubly protonated enthylenediamine cations are located at the tunnels formed by 8-membered rings (four La and four sulfate anions)

  7. Exchange reaction of acetylene-d2 with hydrogen chloride

    International Nuclear Information System (INIS)

    Bopp, A.F.; Kern, R.D.

    1975-01-01

    A mixture containing 3 percent each of the reactants C 2 D 2 and HCl in an Ne--Ar diluent was studied over the temperature range 1650 to 2600 0 K utilizing a shock tube coupled to a time-of-flight mass spectrometer. Plots of the mole fractions f of the exchange products, DCl and C 2 HD, revealed two distinct regions of growth: (a) an initial low conversion region characterized by an induction period t/sub i/; and (b) a region of accelerated exchange during which exchange products were formed with a quadratic dependence of the reaction time. These two regions labeled a and b were combined using two empirical equations, 1 - f/sub a//f/sub eq,a/ = exp [-k/sub a/[M]t], where t less than or equal to t/sub i/, and 1 - f/sub b//f/sub eq,b/ = exp [-k/sub b/[M](t - t/sub i/) 2 ], in order to represent the entire reaction profile at any given temperature within the interval investigated. The Arrhenius parameters for k/sub a/ and k/sub b/ were determined to be 10 11 . 15+-0 . 30 exp (-19990 +- 2850/RT) and 10 16 . 40+-0 . 41 exp (-31480 +- 4200/RT), respectively, for DCl and 10 11 . 69+-0 . 29 exp (-19150 +- 2740/RT) and 10 15 . 24+-0 . 34 exp (-17620 +- 3480/RT) for C 2 HD. The units for k/sub a/ are cm 3 mol -1 sec -1 and cm 3 mol -1 sec -2 for k/sub b/. Activation energies are reported in cal mol -1 . Comparison with the profiles obtained for acetylene pyrolysis strongly suggests that the mechanism for the exchange is atomic. Furthermore, the exchange experiments indicate that the initial step in the pyrolysis of acetylene is the disproportionation reaction, 2C 2 H 2 → C 2 H + C 2 H 3

  8. Synthesis and structural characterization of two cobalt phosphites: 1-D (H3NC6H4NH3)Co(HPO3)2 and 2-D (NH4)2Co2(HPo3)3

    International Nuclear Information System (INIS)

    Cheng, C.-C.; Chang, W.-K.; Chiang, R.-K.; Wang, S.-L.

    2010-01-01

    Two new cobalt phosphites, (H 3 NC 6 H 4 NH 3 )Co(HPO 3 ) 2 (1) and (NH 4 ) 2 Co 2 (HPO 3 ) 3 (2), have been synthesized and characterized by single-crystal X-ray diffraction. All the cobalt atoms of 1 are in tetrahedral CoO 4 coordination. The structure of 1 comprises twisted square chains of four-rings, which contain alternating vertex-shared CoO 4 tetrahedra and HPO 3 groups. These chains are interlinked with trans-1,4-diaminocyclohexane cations by hydrogen bonds. The 2-D structure of 2 comprises anionic complex sheets with ammonium cations present between them. An anionic complex sheet contains three-deck phosphite units, which are interconnected by Co 2 O 9 to form complex layers. Magnetic susceptibility measurements of 1 and 2 showed that they have a weak antiferromagnetic interaction. - Graphical abstract: The 2-D structure of (NH 4 ) 2 Co 2 (HPO 3 ) 3 comprises anionic complex sheets with ammonium cations present between them. An anionic complex sheet contains three-deck phosphite units, which are interconnected by dimmeric Co 2 O 9 to form complex layers.

  9. Studies of molecular association in H2O and D2O vapors by measurement of thermal conductivity

    International Nuclear Information System (INIS)

    Curtiss, L.A.; Frurip, D.J.; Blander, M.

    1979-01-01

    The thermal conductivities of H 2 O and D 2 O vapors were measured in a modified thick hot wire cell between 358 and 386 K at pressures ranging from 100 to 1000 Torr. Analysis of the data indicates that molecular association to form a dimeric species is the main source of enhancement of the thermal conductivity of both vapors. The enthalpy and entropy of association of the H 2 O dimer are -3.59 kcal mol -1 and -18.59 cal deg -1 mol -1 , respectively. The enthalpy and entropy of association of the D 2 O dimer are -3.66 kcal mol -1 and -18.67 cal deg -1 mol -1 , respectively. The measured enthalpy of association of the H 2 O dimer is in agreement with recently reported ab initio molecular orbital calculations on the H 2 O dimer. The entropies of association of the H 2 O and D 2 O dimers are calculated theoretically and are found to be in agreement with the measured values

  10. Vibrational state-resolved differential cross sections for the D + H2 → DH + H reaction

    International Nuclear Information System (INIS)

    Continetti, R.E.

    1989-11-01

    In this thesis, crossed-molecular-beams studies of the reaction D + H 2 → DH + H at collision energies of 0.53 and 1.01 eV are reported. Chapter 1 provides a survey of important experimental and theoretical studies on the dynamics of the hydrogen exchange reaction. Chapter 2 discusses the development of the excimer-laser photolysis D atom beam source that was used in these studies and preliminary experiments on the D + H 2 reaction. In Chapter 3, the differential cross section measurements are presented and compared to recent theoretical predictions. The measured differential cross sections for rotationally excited DH products showed significant deviations from recent quantum scattering calculations, in the first detailed comparison of experimental and theoretical differential cross sections. These results indicate that further work on the H 3 potential energy surface, particularly the bending potential, is in order

  11. D2-H2 equilibration over γ-irradiated zeolites

    International Nuclear Information System (INIS)

    Novakova, J.; Wichterlova, B.

    1987-01-01

    D 2 -H 2 equilibration was studied at 77 and 298 K over HY, AlHY, HZSM-5 and Alsub(x)Osub(y)HZSM-5 zeolites which had been γ-irradiated at 77 and/or 298 K. The exchange rate was found to be higher at the lower temperature regardless of the temperature of irradiation. Moreover, at 77 K the exchange rates were similar and more stable over the individual zeolites than at 298 K, thus indicating a common reaction path at 77 K. The exchange rate at 298 K depended on the zeolite type: it was more stable and higher over HZSM-5 than over HY, and extra-lattice Al increased both these properties on HY as well as on HZSM-5. The reaction mechanism is discussed in connection with the nature of defects generated by γ-irradiation. (author)

  12. Recovery of deuterium from H-D gas mixture by thermal diffusion in a multi-concentric-tube column device of fixed total sum of column heights with transverse sampling streams

    International Nuclear Information System (INIS)

    Yeh, H.-M.

    2010-01-01

    The effect of the increment in the number of concentric-tube thermal diffusion columns on the recovery of deuterium from H 2 -HD-D 2 system with fixed total sum of column heights, has been investigated. The equations for predicting the degrees of separation in single-column, double-column and triple-column devices have been derived. Considerable improvement in recovery can be achieved if a multi-column device with larger number of column is employed, instead of a single-column device with column height equal to the same total sum of column heights, especially for the case of higher flow-rate operation and larger total sum of column heights.

  13. Detecting moisture transport pathways to the subtropical North Atlantic free troposphere using paired H2O-δD in situ measurements

    Directory of Open Access Journals (Sweden)

    Y. González

    2016-04-01

    Full Text Available We present two years of in situ measurements of water vapour (H2O and its isotopologue ratio (δD, the standardized ratio between H216O and HD16O, made at two remote mountain sites on Tenerife in the subtropical North Atlantic. We show that the data – if measured during night-time – are well representative for the lower/middle free troposphere. We use the measured H2O-δD pairs, together with dust measurements and back trajectory modelling for analysing the moisture pathways to this region. We can identify four principally different transport pathways. The air mass transport from high altitudes and high latitudes shows two different scenarios. The first scenario brings dry air masses to the stations, as the result of condensation events occurring at low temperatures. The second scenario brings humid air masses to the stations, due to cross-isentropic mixing with lower-level and more humid air during transport since last condensation (LC. The third pathway is transportation from lower latitudes and lower altitudes, whereby we can identify rain re-evaporation as an occasional source of moisture. The fourth pathway is linked to the African continent, where during summer, dry convection processes over the Sahara very effectively inject humidity from the boundary layer to higher altitudes. This so-called Saharan Air Layer (SAL is then advected westward over the Atlantic and contributes to moisten the free troposphere. We demonstrate that the different pathways leave distinct fingerprints on the measured H2O-δD pairs.

  14. Infrared absorption spectra of gaseous HD. II. Collision-induced fundamental band of HD in HD--Ne and HD--Ar mixtures at room temperature

    International Nuclear Information System (INIS)

    Prasad, R.D.G.; Reddy, S.P.

    1976-01-01

    The collision-induced infrared absorption spectra of the fundamental band of HD in binary mixtures of HD with Ne and Ar at room temperature have been studied with an absorption path length of 105.2 cm for different base densities of HD in the range 8--20 amagat and a number of total gas densities up to 175 amagat. The observed features of the profiles of the enhancement of absorption in these mixtures resemble closely those of the corresponding profiles of the fundamental band of H 2 in binary mixtures with Ne and Ar. The binary absorption coefficients of the band obtained from the measured integrated intensities are (1.84 +- 0.06) x 10 -35 and (4.41 +- 0.06) x 10 -35 cm 6 s -1 for HD--Ne and HD--Ar, respectively. The characteristic half-width parameters, delta/subd/ and delta/subc/ of the overlap transitions and delta/subq/ (and delta/subq//sub prime/) of the quadrupolar transitions, are obtained from an analysis of the profiles of the enhancement of absorption in both these mixtures. The quantity delta/subc/ which is the half-width of the intercollisional interference dip of the Q branch increases with the density of the perturbing gas Ne or Ar, and for HD--Ne it varies in a manner similar to that for HD--He as described in Paper I of this series

  15. MASCARA-2 b. A hot Jupiter transiting the mV = 7.6 A-star HD 185603

    Science.gov (United States)

    Talens, G. J. J.; Justesen, A. B.; Albrecht, S.; McCormac, J.; Van Eylen, V.; Otten, G. P. P. L.; Murgas, F.; Palle, E.; Pollacco, D.; Stuik, R.; Spronck, J. F. P.; Lesage, A.-L.; Grundahl, F.; Fredslund Andersen, M.; Antoci, V.; Snellen, I. A. G.

    2018-04-01

    In this paper we present MASCARA-2 b, a hot Jupiter transiting the mV = 7.6 A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of the star, corresponding to a total of almost 3000 h of observations, revealing a periodic dimming in the flux with a depth of 1.3%. Photometric follow-up observations were performed with the NITES and IAC80 telescopes and spectroscopic measurements were obtained with the Hertzsprung SONG telescope. We find MASCARA-2 b orbits HD 185603 with a period of 3.4741119-0.000006+0.000005 at a distance of 0.057 ± 0.006 au, has a radius of 1.83 ± 0.07 RJ and place a 99% upper limit on the mass of http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A57

  16. DIRECT DETERMINATION OF THE HF/H{sub 2} ABUNDANCE RATIO IN INTERSTELLAR GAS

    Energy Technology Data Exchange (ETDEWEB)

    Indriolo, Nick; Neufeld, D. A. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Seifahrt, A. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Richter, M. J. [Department of Physics, University of California Davis, Davis, CA 95616 (United States)

    2013-02-20

    We report the first detection of the v = 1-0, R(0) ro-vibrational transition of HF at 2.499385 {mu}m arising from interstellar gas. The line is seen in absorption toward three background sources-HD 154368, Elias 29, and AFGL 2136 IRS 1-all of which have reported H{sub 2} column densities determined from observations of H{sub 2}. This allows for the first direct determination of the HF/H{sub 2} abundance ratio. We find values of N(HF)/N(H{sub 2}) = 1.15 Multiplication-Sign 10{sup -8} and 0.69 Multiplication-Sign 10{sup -8} for HD 154368 and Elias 29, respectively. The sight line toward AFGL 2136 IRS 1 also shows absorption from the v = 1-0, R(1) transition of HF, indicating warm, dense (n {sub H} {approx}> 10{sup 9} cm{sup -3}) gas, likely very close to the central protostar. Ascribing portions of the HF absorption to warm and cold gas, we find N(HF)/N(H{sub 2}) = (1.7-2.9) Multiplication-Sign 10{sup -8} and (0.33-0.58) Multiplication-Sign 10{sup -8} for the two components, respectively. Except for the warm component toward AFGL 2136 IRS 1, all observed HF/H{sub 2} ratios are well below N(HF)/N(H{sub 2}) = 3.6 Multiplication-Sign 10{sup -8}, the value predicted if nearly all gas phase fluorine is in the form of HF. Models of fluorine chemistry that account for depletion onto grains are able to reproduce the results toward HD 154368, but not in the cold, dense gas toward AFGL 2136 IRS 1 and Elias 29. Most likely, some combinations of simplifying assumptions made in the chemical models are responsible for these discrepancies.

  17. Quasiclassical Studies of Eley-Rideal and Hot Atom Reactions on Surface: H(D)→D(H)+Cu(111)

    International Nuclear Information System (INIS)

    Vurdu, C.D.

    2004-01-01

    Randomly distributed hydrogen adsorbates on the surface of Cu(1 1 1) are used to form 0.50, 0.25 and 0.15 monolayers of coverages to simulate D(H)→H(D) + Cu(111) system at 30 K and 94 K surface temperatures. The interaction of this system is mimicked by a LEPS function which is parameterized by using the energy points which were calculated by a density-functional theory method and the generalized gradient approximation for the exchange-correlation energy for various configurations of one a,nd two hydrogen atoms on the Cu(111) surface. Our results on H 2 , D 2 , and HD formations via Eley-Redial and hot-atom mechanisms will be presented at these temperatures. Probabilities for the rotational, vibrational, total and translational energy distributions of the products are calculated. In addition traping onto the surface, inelastic reflection of the incident projectile and penetration of the adsorbate or projectile atom into the slab is analyzed. Hot-atom pathways for product formations are shown to make significant contributions

  18. High temperature thermodynamics of H2 and D2 in titanium, and in dilute titanium oxygen solid solutions

    International Nuclear Information System (INIS)

    Dantzer, P.

    1983-01-01

    The Tian Calvet microcalorimetric method has been improved in order to determine ΔH-barsub(H)(D), the partial molar enthalpy of mixing of hydrogen (deuterium) in the Ti-H 2 (D 2 ) solid systems for compositions 0 2 solid solutions (y = (O/Ti)) at 745 K. The combined calorimetric and equilibrium method allows a precise evaluation of the partial molar entropies. The results of this study differ substantially from earlier published data. (author)

  19. Significance of porous structure on degradatin of 2 2' dichloro diethyl sulphide and 2 chloroethyl ethyl sulphide on the surface of vanadium oxide nanostructure

    International Nuclear Information System (INIS)

    Singh, Beer; Mahato, T.H.; Srivastava, A.K.; Prasad, G.K.; Ganesan, K.; Vijayaraghavan, R.; Jain, Rajeev

    2011-01-01

    Degradation of the king of chemical warfare agent, 2 2' dichloro diethyl sulphide (HD), and its simulant 2 chloroethyl ethyl sulphide (CEES) were investigated on the surface of porous vanadium oxide nanotubes at room temperature (30 ± 2 ° C ). Reaction kinetics was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data indicates that HD degraded faster relative to CEES inside the solid decontaminant compared to the reported liquid phase degradation of CEES and HD. Data explores the role of hydrolysis, elimination and oxidation reactions in the detoxification of HD and CEES and the first order rate constant and t 1/2 were calculated to be 0.026 h -1 , 26.6 h for CEES and 0.052 h -1 , 13.24 h for HD. In this report faster degradation of HD compared to CEES was explained on the basis of porous structure.

  20. Extraction of volume produced H- or D- ions from a sheet plasma, 2

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1984-02-01

    A development to large area H - or D - ion source is tried by using three extraction electrodes: The first electrode bias voltage is set near the wall potential (floating), the second electrode is set near 13 % of main extraction voltage and the third electrode is the main acceleration electrode. An ion current of 13 mA (3.3 mA/cm 2 ) for H - or 11 mA (2.8 mA/ cm 2 ) for D - at 3 KeV is extracted from 9 apertures of 6 mm phi in 4 cm 2 outside of the sheet plasma (14 cm wide and 1.0 cm thick) under a pressure of 7.7 x 10 -4 H2 or D2 gas and a weak magnetic field 50 gauss. Then, it is noted that the corresponding electron current is suppressed below 1/10 of the H - or D - ion current. (author)

  1. Biosynthesis, purification and receptor binding properties of high specific radioactivity 1α,24(R), 25-trihydroxy-[26,27-methyl-3H]-vitamin D3

    International Nuclear Information System (INIS)

    Chandler, J.S.; Pike, J.W.; Haussler, M.R.

    1982-01-01

    A procedure for the biosynthesis and purification of 1α,24(R),25-trihydroxy[26,27-methyl- 3 H]-vitamin D 3 (1,24,25-(OH) 3 [ 3 H]D 3 ) is reported. A kidney homogenate from chicks receiving a high calcium diet (3%) and oral supplements of 1α,25-dihydroxyvitamin D 3 (1,25-(OH) 2 D 3 ) was used for C-24-hydroxylation of 1α,25-dihydroxy[26,27-methyl- 3 H]-vitamin D 3 (1,25-(OH) 2 [ 3 H]D 3 ), in vitro. Extraction and purification of the homogenate lipid fraction by Sephadex LH-20 and high performance liquid chromatography yielded radiochemically pure 1,24,25-(OH) 3 [ 3 H]D 3 with a specific radioactivity equivalent to the initial substrate (166 Ci/mmol). The authenticity of the generated metabolite was assessed by co-migration with synthetic 1,24,25-(OH) 3 D 3 on high performance liquid chromatography and by equimolar competition with authentic radioinert 1,24,25-(OH) 3 D 3 for binding to a purified receptor protein from rat kidney. Binding studies indicate the trihydroxylated metabolite competes 40-50% as effectively as 1,25-(OH) 2 D 3 for hormone binding sites. Further analysis of 1,24,25-(OH) 3 D 3 -receptor interaction reveals a high-affinity, saturable binding with an apparent Ksub(d) of 2.2 x 10 -9 M. These studies demonstrate that although slightly less active than 1,25-(OH) 2 D 3 , 1,24,25-(OH) 3 D 3 is capable of hormone-like interactions, in vitro. The availability of this high specific radioactivity sterol should allow for clarification of its potential physiologic significance. (author)

  2. Dopamine D2 receptor radiotracers [11C](+)-PHNO and [3H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    International Nuclear Information System (INIS)

    McCormick, Patrick N.; Kapur, Shitij; Seeman, Philip; Wilson, Alan A.

    2008-01-01

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [ 11 C](+)-PHNO ([ 11 C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [ 3 H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [ 11 C](+)-PHNO and [ 3 H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for 11 C and 3 H. The specific binding ratio {SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum)} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [ 11 C](+)-PHNO and [ 3 H]raclopride SBRs responded indistinguishably in terms of both ED 50 and Hill slope (e.g., (-)-NPA ED 50 values are 0.027 and 0.023 mg/kg for [ 11 C](+)-PHNO and [ 3 H]raclopride, respectively). In response to AMPH challenge, [ 11 C](+)-PHNO and [ 3 H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [ 11 C](+)-PHNO- and [ 3 H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo applicability of the D2 two-state model, as described by in vitro binding experiments

  3. Mechanical Design of HD2, a 15 T Nb3Sn Dipole Magnet with a 35 mm Bore

    Energy Technology Data Exchange (ETDEWEB)

    Ferracin, P.; Bartlett, S.E.; Caspi, S.; Dietderich, D.R.; Gourlay, S.A.; Hafalia, A.R.; Hannaford, C.R.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Sabbi, G.L.

    2006-06-01

    After the fabrication and test of HD1, a 16 T Nb{sub 3}Sn dipole magnet based on flat racetrack coil configuration, the Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is developing the Nb{sub 3}Sn dipole HD2. With a dipole field above 15 T, a 35 mm clear bore, and nominal field harmonics within a fraction of one unit, HD2 represents a further step towards the application of block-type coils to high-field accelerator magnets. The design features tilted racetrack-type ends, to avoid obstructing the beam path, and a 4 mm thick stainless steel tube, to support the coil during the preloading operation. The mechanical structure, similar to the one used for HD1, is based on an external aluminum shell pretensioned with pressurized bladders. Axial rods and stainless steel plates provide longitudinal support to the coil ends during magnet excitation. A 3D finite element analysis has been performed to evaluate stresses and deformations from assembly to excitation, with particular emphasis on conductor displacements due to Lorentz forces. Numerical results are presented and discussed.

  4. Isolation and characterization of ScGluD2, a new sugarcane beta-1,3-glucanase D family gene induced by Sporisorium scitamineum, ABA, H2O2, NaCl, and CdCl2 stresses

    Directory of Open Access Journals (Sweden)

    Yachun Su

    2016-09-01

    Full Text Available Beta-1,3-glucanases (EC 3.2.1.39, commonly known as pathogenesis-related (PR proteins, play an important role not only in plant defense against fungal pathogens but also in plant physiological and developmental processes. However, only a limited number of sugarcane beta-1,3-glucanase genes have been isolated. In the present study, we identified and characterized a new beta-1,3-glucanase gene ScGluD2 (GenBank Acc No. KF664181 from sugarcane. An X8 domain was present at the C terminal region of ScGluD2, suggesting beta-1,3-glucan-binding function. Phylogenetic analysis showed that the predicted ScGluD2 protein was classified into subfamily D beta-1,3-glucanase. Localization of the ScGluD2 protein in the plasma membrane was determined by tagging it with green fluorescent protein. The expression of ScGluD2 was more up-regulated in sugarcane smut-resistant cultivars in the early stage (1 d or 3 d than in the susceptible ones after being challenged by the smut pathogen, revealing that ScGluD2 may be involved in defense against the invasion of Sporisorium scitamineum. Transient overexpression of ScGluD2 in Nicotiana benthamiana leaves induced a defense response and exhibited antimicrobial action on the tobacco pathogens Pseudomonas solanacearum and Botrytis cinerea, further demonstrating that ScGluD2 was related to the resistance to plant pathogens. However, the transcripts of ScGluD2 partially increased (12 h under NaCl stress, and were steadily up-regulated from 6 h to 24 h upon ABA, H2O2, and CdCl2 treatments, suggesting that ABA may be a signal molecule regulating oxidative stress and play a role in the salt and heavy metal stress-induced stimulation of ScGluD2 transcripts. Taken together, ScGluD2, a novel member of subfamily D beta-1,3-glucanase, was a stress-related gene of sugarcane involved in plant defense against smut pathogen attack and salt and heavy metal stresses.

  5. Absorption spectra between 0.8 {mu} and 30 {mu} of mixtures of H{sub 2}O - D{sub 2}O in the liquid state; Le spectre d'absorption des melanges H{sub 2}O-D{sub 2}O a l'etat liquide entre 0,8 et 30 {mu}

    Energy Technology Data Exchange (ETDEWEB)

    Ceccaldi, M; Goldman, M; Roth, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    There has been very little work carried out recently on the absorption bands of H{sub 2}O, HDO and D{sub 2}O in the liquid state. We have established the spectra of these molecules in between 0.8 and 30 p. The table of absorption bands of the molecules HDO and D{sub 2}O for which all the bands corresponding to those for H{sub 2}O had not been established has been completed. We have sought a convenient method of representing the variations in optical density of certain HDO bands as a function of the concentration of heavy water in the mixtures studied. (author) [French] Il y a peu de travaux recents sur les bandes d'absorption de H{sub 2}O, HDO et D{sub 2}O a l'etat liquide. Nous avons releve les spectres de ces molecules entre 0,8 et 30 p. Le tableau des bandes d'absorption des molecules HDO et D{sub 2}O, pour lesquelles le releve de toutes les bandes correspondantes a celles de H{sub 2}O n'etait pas encore effectue, a ete complete. Nous avons cherche des modes de representation commodes des variations de densite optique de certaines bandes de HDO en fonction de la teneur en eau lourde des melanges etudies. (auteur)

  6. Disruption of dopamine D1/D2 receptor complex is involved in the function of haloperidol in cardiac H9c2 cells.

    Science.gov (United States)

    Lencesova, L; Szadvari, I; Babula, P; Kubickova, J; Chovancova, B; Lopusna, K; Rezuchova, I; Novakova, Z; Krizanova, O; Novakova, M

    2017-12-15

    Haloperidol is an antipsychotic agent and acts as dopamine D2 receptor (D2R) antagonist, as a prototypical ligand of sigma1 receptors (Sig1R) and it increases expression of type 1 IP 3 receptors (IP 3 R1). However, precise mechanism of haloperidol action on cardiomyocytes through dopaminergic signaling was not described yet. This study investigated a role of dopamine receptors in haloperidol-induced increase in IP 3 R1 and Sig1R, and compared physiological effect of melperone and haloperidol on basic heart parameters in rats. We used differentiated NG-108 cells and H9c2 cells. Gene expression, Western blot and immunofluorescence were used to evaluate haloperidol-induced differences; proximity ligation assay (PLA) and immunoprecipitation to determine interactions of D1/D2 receptors. To evaluate cardiac parameters, Wistar albino male rats were used. We have shown that antagonism of D2R with either haloperidol or melperone results in upregulation of both, IP 3 R1 and Sig1R, which is associated with increased D2R, but reduced D1R expression. Immunofluorescence, immunoprecipitation and PLA support formation of heteromeric D1/D2 complexes in H9c2 cells. Treatment with haloperidol (but not melperone) caused decrease in systolic and diastolic blood pressure and significant increase in heart rate. Because D1R/D2R complexes can engage Gq-like signaling in other experimental systems, these results are consistent with the possibility that disruption of D1R/D2R complex in H9c2 cells might cause a decrease in IP 3 R1 activity, which in turn may account for the increase expression of IP 3 R and Sig1R. D2R is probably not responsible for changes in cardiac parameters, since melperone did not have any effect. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Significance of porous structure on degradatin of 2 2' dichloro diethyl sulphide and 2 chloroethyl ethyl sulphide on the surface of vanadium oxide nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Beer, E-mail: beerbs5@rediffmail.com [Defence R and D Establishment, Jhansi Road, Gwalior, M.P 474002 (India); Mahato, T.H.; Srivastava, A.K.; Prasad, G.K.; Ganesan, K.; Vijayaraghavan, R. [Defence R and D Establishment, Jhansi Road, Gwalior, M.P 474002 (India); Jain, Rajeev [School of Studies in Chemistry, Jiwaji University, Gwalior, M.P. 474011 (India)

    2011-06-15

    Degradation of the king of chemical warfare agent, 2 2' dichloro diethyl sulphide (HD), and its simulant 2 chloroethyl ethyl sulphide (CEES) were investigated on the surface of porous vanadium oxide nanotubes at room temperature (30 {+-} 2{sup Degree-Sign }C ). Reaction kinetics was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data indicates that HD degraded faster relative to CEES inside the solid decontaminant compared to the reported liquid phase degradation of CEES and HD. Data explores the role of hydrolysis, elimination and oxidation reactions in the detoxification of HD and CEES and the first order rate constant and t{sub 1/2} were calculated to be 0.026 h{sup -1}, 26.6 h for CEES and 0.052 h{sup -1}, 13.24 h for HD. In this report faster degradation of HD compared to CEES was explained on the basis of porous structure.

  8. Electron capture and excitation in collisions of O+(4S,2D,2P) with H2 molecules

    International Nuclear Information System (INIS)

    Pichl, Lukas; Li Yan; Liebermann, Heinz-Peter; Buenker, Robert J.; Kimura, Mineo

    2004-01-01

    Using an electronic-state close-coupling method, we treated the electron capture and excitation processes of O + ions both in ground state O + ( 4 S) and metastable states O +* ( 2 D) and O +* ( 2 P) in collisions with the H 2 molecule. In the ground-state projectile energy region considered (from 50 eV/amu to 10 keV/amu), the experimental data vary by orders of magnitude: our results smoothly connect to the data by Flesch and Ng [J. Chem. Phys. 94, 2372 (1991)] and Xu et al. [J. Phys. B 23, 1235 (1990)] at low energy and agree with Phaneuf et al. [Phys. Rev. A 17, 534 (1978)] in the high-energy region. The present values differ from Sieglaff et al. [Phys. Rev. A 59, 3538 (1999)] and Nutt et al. [J. Phys. B 12, L157 (1979)], especially in the energy region below 1 keV/amu. We provide the first calculated state-resolved cross sections of electron capture and target-projectile electronic excitations for the O + ( 4 S, 2 D, 2 P)-H 2 collision system

  9. Synthesis of (R)-5-(Di[2,3-3H2]propylamino)-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one-([3H]U-86170) and (R)-5-([2,3-3H2]propylamino)-5,6-dihydro-4H-imidazo(4,5,1-ij) quinolin-2(1H)-one ([3H]U-91356)

    International Nuclear Information System (INIS)

    Moon, M.W.; Hsi, R.S.P.

    1992-01-01

    (R)-5-(diallylamino)-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one (12b) was prepared in 9% overall yield from 3-aminoquinoline. Reaction of 12b in ethyl acetate with tritium gas in presence of a 5% platinum on carbon catalyst afforded a mixture of (R)-5-(di[2,3- 3 H 2 ]propylamino)-5,6-dihydro-4H-imidazo[4,5,1-ij]-quinolin-2(1H)-one ([ 3 H]U-86170, 69 Ci/mmol) and (R)-5-([2,3- 3 H 2 ]-propylamino)5,6-dihydro-4H-imidazo-[4,5,1-ij]quinolin-2(1H)-one ( [ 3 H]U-91356, 34 Ci/mmol) which was separated by preparative reverse-phase chromatography. U-86170 and U-91356 are potent dopamine D2 agonists. The labelled compounds are useful for drug disposition studies. [ 3 H]U-86170 is also useful as a dopamine D2 agonist radioligand for receptor binding studies. (author)

  10. Central-field intermolecular potentials from the differential elastic scattering of H2(D2) by other molecules

    International Nuclear Information System (INIS)

    Kuppermann, Aron; Gordon, R.J.; Coggiola, M.J.

    1974-01-01

    Differential elastic scattering cross sections for the systems H 2 +O 2 , SF 6 , NH 3 , CO, and CH 4 and for D 2 +O 2 , SF 6 , and NH 3 have been obtained from crossed beam studies. In all cases, rapid quantum oscillations have been resolved which permit the determination of intermolecular potentiel parameters if a central-field assumption is adopted. These potentials were found to be independent of both the isotopic form of the hydrogen molecule, and the relative collision energy. As a result of this, and the ability of these spherical potentials to quantitatively describe the measured scattering, it is concluded that anisotropy effects do not seem important in these H 2 (D 2 ) systems

  11. 2D Bayesian automated tilted-ring fitting of disc galaxies in large H I galaxy surveys: 2DBAT

    Science.gov (United States)

    Oh, Se-Heon; Staveley-Smith, Lister; Spekkens, Kristine; Kamphuis, Peter; Koribalski, Bärbel S.

    2018-01-01

    We present a novel algorithm based on a Bayesian method for 2D tilted-ring analysis of disc galaxy velocity fields. Compared to the conventional algorithms based on a chi-squared minimization procedure, this new Bayesian-based algorithm suffers less from local minima of the model parameters even with highly multimodal posterior distributions. Moreover, the Bayesian analysis, implemented via Markov Chain Monte Carlo sampling, only requires broad ranges of posterior distributions of the parameters, which makes the fitting procedure fully automated. This feature will be essential when performing kinematic analysis on the large number of resolved galaxies expected to be detected in neutral hydrogen (H I) surveys with the Square Kilometre Array and its pathfinders. The so-called 2D Bayesian Automated Tilted-ring fitter (2DBAT) implements Bayesian fits of 2D tilted-ring models in order to derive rotation curves of galaxies. We explore 2DBAT performance on (a) artificial H I data cubes built based on representative rotation curves of intermediate-mass and massive spiral galaxies, and (b) Australia Telescope Compact Array H I data from the Local Volume H I Survey. We find that 2DBAT works best for well-resolved galaxies with intermediate inclinations (20° < i < 70°), complementing 3D techniques better suited to modelling inclined galaxies.

  12. H-D exchange in metal carbene complexes: Structure of cluster (μ-H)(μ-OCD3)Os3(CO)9{:C(CD3)NC2H8O}

    Science.gov (United States)

    Savkov, Boris; Maksakov, Vladimir; Kuratieva, Natalia

    2015-10-01

    X-ray and spectroscopic data for the new complex (μ-H)(μ-OCH3)Os3(CO)9{:C(CD3)NC2H8O} (2) obtained in the reaction of the (μ-H)(μ-Cl)Os3(CO)9{:C(CH3)NC2H8O} (1) with NaOCD3 in CD3OD solution are reported. It is shown that cluster 1 has the property of CH-acidity inherent of Fisher type carbenes. This had demonstrated using hydrogen deuterium exchange reaction in the presence of a strong base. Bridging chlorine to metoxide ligand substitution takes place during the reaction. The molecular structure of 2 is compared with known analogues.

  13. Electron-impact excitation and recombination of molecular cations in edge fusion plasma: application to H2+and BeD+

    Science.gov (United States)

    Pop, Nicolina; Iacob, Felix; Mezei, Zsolt; Motapon, Ousmanou; Niyonzima, Sebastien; Schneider, Ioan

    2017-10-01

    Dissociative recombination, ro-vibrational excitation and dissociative excitation of molecular cations with electrons are major elementary process in the kinetics and in the energy balance of astrophysically-relevant ionized media (supernovae, interstellar molecular clouds, planetary ionospheres, early Universe), in edge fusion and in many other cold media of technological interest. For the fusion plasma edge, extensive cross sections and rate coefficients have been produced for reactions induced on HD+, H2+ and BeD+ using the Multichannel Quantum Defect Theory (MQDT). Our calculations resulted in good agreement with the CRYRING (Stockholm) and TSR (Heidelberg) magnetic storage ring results, and our approach is permanently improved in order to face the new generation of electrostatic storage rings, as CSR (Heidelberg) and DESIREE (Stockholm). Member of APS Reciprocal Society: European Physics Society.

  14. Study in crossed molecular beams of the state-to-state reactive collision: O("1D) + H_2(X "1Σ_g"+,v) → OH(X "2Π and A"2Σ"+,v',J') + H("2S)

    International Nuclear Information System (INIS)

    Drawin, Stefan

    1990-01-01

    Reactions between oxygen and hydrogen such as O + H_2 → OH + H play a significant role in combustion processes and in atmospheric and interstellar chemistry. But they are also examples of reactive collisions between atoms and molecules which can be addressed theoretically and experimentally for a better understanding of mechanisms present in a chemical reaction. This research thesis reports the experimental study of two reactive ways involving the metastable compound O("1D): O("1D) + H_2 → OH(X "2Π) + H O("1D) + H_2 → OH(A "2Σ"+) + H. The experiment is performed by using crossed molecular beams. Thus, the nature of reactants is well defined, and the interaction medium is rarefied. The first way is largely exothermic, whereas for the second one, endothermicity is overcome by H_2 vibrational excitation. A characterization of reactants is performed. Three methods of analysis of the OH product are used: time-of-flight measurement at different angles, laser induced fluorescence, and spontaneous fluorescence [fr

  15. Vibrational state-resolved differential cross sections for the D + H sub 2 yields DH + H reaction

    Energy Technology Data Exchange (ETDEWEB)

    Continetti, R.E.

    1989-11-01

    In this thesis, crossed-molecular-beams studies of the reaction D + H{sub 2} {yields} DH + H at collision energies of 0.53 and 1.01 eV are reported. Chapter 1 provides a survey of important experimental and theoretical studies on the dynamics of the hydrogen exchange reaction. Chapter 2 discusses the development of the excimer-laser photolysis D atom beam source that was used in these studies and preliminary experiments on the D + H{sub 2} reaction. In Chapter 3, the differential cross section measurements are presented and compared to recent theoretical predictions. The measured differential cross sections for rotationally excited DH products showed significant deviations from recent quantum scattering calculations, in the first detailed comparison of experimental and theoretical differential cross sections. These results indicate that further work on the H{sub 3} potential energy surface, particularly the bending potential, is in order.

  16. Optically stimulated luminescence study on gamma-irradiated ice frozen from H sub 2 O and D sub 2 O

    CERN Document Server

    Yada, T; Hirai, M; Yamanaka, C; Ikeya, M

    2002-01-01

    Optically stimulated luminescence (OSL) and thermoluminescence (TL) for gamma-irradiated ice samples have been investigated as future dating techniques for icy bodies in the solar system. The OSL around 400nm lasted more than 600s for gamma-irradiated H sub 2 O ice and D sub 2 O ice under 623-nm-light stimulation at 90 K; the latter was used to study the migration of hydrogen atoms. A defect containing trapped electrons is the most suitable explanation of the OSL emissions. The intensity of the TL peak at 120 K increased linearly with gamma-dosage increasing up to 15 kGy for both D sub 2 O ice and H sub 2 O ice. Intensities of both OSL and TL for D sub 2 O ice were larger than those for H sub 2 O ice. The TL peak related to H sub 2 O was observed but its thermal characteristics did not agree with those of OH and HO sub 2 radicals measured by ESR. The OSL method should be employed in future surveys in the solar system.

  17. Chemical kinetics in H2O and D2O under hydrothermal conditions

    International Nuclear Information System (INIS)

    Ghandi, K.; Alcorn, C.D.; Legate, G.; Percival, P.W.; Brodovitch, J.-C.

    2010-01-01

    Muonium (Mu = μ + e - ) is a light analogue of the H-atom. Studies of Mu chemical kinetics have been extended to supercritical water, a medium in some designs of future generation nuclear reactors. The Supercritical-Water-Cooled Reactor (SCWR) would operate at higher temperatures than current pressurized water-cooled reactors, and the lack of knowledge of water radiolysis under supercritical conditions constitutes a technology gap for SCWR development. Accurate modeling of chemistry in a SCWR requires data on kinetics of reactions involved in the radiolysis of water. In this paper, we first review our measurements of kinetics in H 2 O and then describe new data for D 2 O under sub- and supercritical conditions. (author)

  18. Studies of FCAPT uvby Photometry with Period04: The mCP Stars HD 5797, HD 36792, HD 27309, HD 47913, HD 74521, HD 120198, HD 171263, and HD 215441

    Science.gov (United States)

    Dukes, Robert J., Jr.; Adelman, Saul J.

    2018-04-01

    We present differential Strömgren uvby Four College Automated Photometric Telescope (FCAPT) observations of eight magnetic chemically peculiar stars: HD 5797, HD 26792, HD 27309, HD 49713, HD 74521, HD 120198, HD 171263, and HD 215441. Our data sets are larger than those of most mCP stars in the literature. These are the first FCAPT observations of HD 5797, HD 26792, HD 49713, and HD 171263. Those for the other four stars substantially extend published FCAPT data sets. The FCAPT has observed some stars for a longer time range and with greater accuracy than other optical region telescopes. We determine very accurate periods and u, v, b, and y amplitudes, as well as if there are any long-term periods. Further, we compare our results with those of magnetic field measurements, when they exist, to help interpret the light curves. For each star, we used the Period04 computer program to analyze the uvby light curves. This program provides errors for the derived quantities. Our derived periods of 68.0457 ± 0.0200 days for HD 5797, 3.80205 ± 0.00015 days for HD 26792, 1.5688908 ± 0.0000046 days for HD 27309, 2.135361 ± 0.000031 days for HD 49713, 7.05053 ± 0.00024 for days HD 74521, 1.3857690 ± 0.0000058 days for HD 120198, 3.99744 ± 0.00015 days for HD 171263, and 9.487792 ± 0.000049 days for HD 215441 are refinements of the last determinations in the literature. We also found a low-frequency term for HD 49713 in all four filters.

  19. The TRIUMF compact DC H-/D- ion source

    International Nuclear Information System (INIS)

    Jayamanna, K.; McDonald, M.; Yuan, D.H.; Schmor, P.W.

    1990-06-01

    A compact dc H - /D - ion source using multicusp magnetic plasma confinement, has been experimentally studied and optimized on the TRIUMF ion source test stand. The plasma parameters have been obtained with rapid computer controlled Langmuir probe scans. The extraction electrode configuration, originally tailored to the TR30 cyclotron requirements, has been further developed. With a 12 mm diameter extraction hole this source now provides 9 mA within a normalized emittance of 0.44 π mm-mrad and can be easily modified for lower currents of smaller emittance (1 mA H - current with normalized emittance 0.12π.mm-mrad or 7 mA H - current with normalized emittance 0.34π.mm-mrad). The source has proven to have low maintenance, high reliability and long filament lifetime. This paper emphasizes basic plasma parameters which determine the efficiency of H - /D - production. Some experimental results obtained from several versions of the extraction system are also described. (Author) 6 refs., 8 figs

  20. 24,25,28-Trihydroxyvitamin D2 and 24,25,26-trihydroxyvitamin D2: Novel metabolites of vitamin D2

    International Nuclear Information System (INIS)

    Reddy, G.S.; Tserng, K.

    1990-01-01

    Understanding of the inactivation pathways of 25-hydroxyvitamin D 2 and 24-hydroxyvitamin D 2 , the two physiologically significant monohydroxylated metabolites of vitamin D 2 , is of importance, especially during hypervitaminosis D 2 . At present, little information is available regarding the inactivation pathway of 25-hydroxyvitamin D 2 except its further metabolism into 24,25-dihydroxyvitamin D 2 . In our present study, the authors investigated the metabolic fate of 25-hydroxyvitamin D 2 in the isolated perfused rat kidney and demonstrated its conversion not only into 24,25-dihydroxyvitamin D 2 but also into two other new metabolites, namely, 24,25,28-trihydroxyvitamin D 2 and 24,25,26-trihydroxyvitamin D 2 . The structure identification of the new metabolites was established by the techniques of ultraviolet absorption spectrophotometry and mass spectrometry and by the characteristic nature of each new metabolite's susceptibility to sodium metaperiodate oxidation. In order to demonstrate the physiological significance of the two new trihydroxy metabolites of vitamin D 2 , induced hypervitaminosis D 2 in a rat using [3α- 3 H]vitamin D 2 and analyzed its plasma for the various [3α- 3 H]vitamin D 2 metabolites on two different high-pressure liquid chromatography systems. The results indicate that both 24,25,26-trihydroxyvitamin D 2 and 24,25,26-trihydroxyvitamin D 2 circulate in the vitamin D 2 intoxicated rat in significant amounts along with other previously identified monohydroxy and dihydroxy metabolites of vitamin D 2 , namely, 24-hydroxyvitamin D 2 , 25-hydroxyvitamin D 2 , and 24,25-dihydroxyvitamin D 2

  1. ROVIBRATIONAL QUENCHING RATE COEFFICIENTS OF HD IN COLLISIONS WITH He

    International Nuclear Information System (INIS)

    Nolte, J. L.; Stancil, P. C.; Lee, T.-G.; Balakrishnan, N.; Forrey, R. C.

    2012-01-01

    Along with H 2 , HD has been found to play an important role in the cooling of the primordial gas for the formation of the first stars and galaxies. It has also been observed in a variety of cool molecular astrophysical environments. The rate of cooling by HD molecules requires knowledge of collisional rate coefficients with the primary impactors, H, He, and H 2 . To improve knowledge of the collisional properties of HD, we present rate coefficients for the He-HD collision system over a range of collision energies from 10 –5 to 5 × 10 3 cm –1 . Fully quantum mechanical scattering calculations were performed for initial HD rovibrational states of j = 0 and 1 for v = 0-17 which utilized accurate diatom rovibrational wave functions. Rate coefficients of all Δv = 0, –1, and –2 transitions are reported. Significant discrepancies with previous calculations, which adopted a small basis and harmonic HD wave functions for excited vibrational levels, were found for the highest previously considered vibrational state of v = 3. Applications of the He-HD rate coefficients in various astrophysical environments are briefly discussed.

  2. Chemical analysis of three barium stars: HD 51959, HD 88035, and HD 121447

    Science.gov (United States)

    Karinkuzhi, Drisya; Goswami, Aruna; Sridhar, Navin; Masseron, Thomas; Purandardas, Meenakshi

    2018-05-01

    We present elemental abundance results from high-resolution spectral analysis of three nitrogen-enhanced barium stars. The analysis is based on spectra obtained with the fibre-fed extended range optical spectrograph attached to 1.52 m telescope at European Southern Observatory, Chile. The spectral resolution is R ˜ 48,000 and the spectral coverage spans from 3500 to 9000Å . For the objects HD 51959 and HD 88035, we present the first-time abundance analyses results. Although a few studies are available in literature on the object HD 121447, the results are significantly different from each other. We have therefore carried out a detailed chemical composition study for this object based on a high-resolution spectrum with high S/N ratio, for a better understanding of the origin of the abundance patterns observed in this star. Stellar atmospheric parameters, the effective temperature, surface gravity, microturbulence, and metallicity of the stars are determined from the local thermodynamic equilibrium analysis using model atmospheres. The metallicities of HD 51959 and HD 88035 are found to be near-solar; they exhibit enhanced abundances of neutron-capture elements. HD 121447 is found to be moderately metal-poor with [Fe/H] = -0.65. While carbon is near-solar in the other two objects, HD 121447 shows carbon enhancement at a level, [C/Fe] = 0.82. Neutron-capture elements are highly enhanced with [X/Fe] > 2 (X: Ba, La, Pr, Nd, Sm) in this object. The α- and iron-peak elements show abundances very similar to field giants with the same metallicity. From kinematic analysis all the three objects are found to be members of thin disc population with a high probability of 0.99, 0.99, and 0.92 for HD 51959, HD 88035, and HD 121447, respectively.

  3. Differential and integral cross sections for the rotationally inelastic scattering of methyl radicals with H2 and D2

    International Nuclear Information System (INIS)

    Tkáč, Ondřej; Orr-Ewing, Andrew J.; Ma, Qianli; Dagdigian, Paul J.; Rusher, Cassandra A.; Greaves, Stuart J.

    2014-01-01

    Comparisons are presented of experimental and theoretical studies of the rotationally inelastic scattering of CD 3 radicals with H 2 and D 2 collision partners at respective collision energies of 680 ± 75 and 640 ± 60 cm −1 . Close-coupling quantum-mechanical calculations performed using a newly constructed ab initio potential energy surface (PES) provide initial-to-final CD 3 rotational level (n, k → n′, k′) integral and differential cross sections (ICSs and DCSs). The DCSs are compared with crossed molecular beam and velocity map imaging measurements of angular scattering distributions, which serve as a critical test of the accuracy of the new PES. In general, there is very good agreement between the experimental measurements and the calculations. The DCSs for CD 3 scattering from both H 2 and D 2 peak in the forward hemisphere for n′ = 2–4 and shift more to sideways and backward scattering for n′ = 5. For n′ = 6–8, the DCSs are dominated by backward scattering. DCSs for a particular CD 3 n → n′ transition have a similar angular dependence with either D 2 or H 2 as collision partner. Any differences between DCSs or ICSs can be attributed to mass effects because the PES is unchanged for CD 3 −H 2 and CD 3 –D 2 collisions. Further comparisons are drawn between the CD 3 –D 2 scattering and results for CD 3 –He presented in our recent paper [O. Tkáč, A. G. Sage, S. J. Greaves, A. J. Orr-Ewing, P. J. Dagdigian, Q. Ma, and M. H. Alexander, Chem. Sci. 4, 4199 (2013)]. These systems have the same reduced mass, but are governed by different PESs

  4. Influence of H/D isotope substitution on physicochemical properties of aqueous solutions of urea and thiourea

    International Nuclear Information System (INIS)

    Jelinska-Kazimierczuk, M.; Szydlowski, J.

    2001-01-01

    The influence of the H/D isotope substitution on excess volumes, partial molar volumes, viscosity and ultrasound speed in aqueous solutions of urea and thiourea are studied at 20 o C. The excess volume of the solutions studied is relatively small - however, it is negative in urea and positive in thiourea solutions. On the other hand, the deuteration affects the excess volume in both solutions in the same way: deuterated systems show smaller deviation from additivity than regular ones. The speed of sound in the systems studied increases monotonously with concentration , but its isotope effect decreases as the concentration increases. The curves of viscosity are monotonous too, but isotope effect of kinematic viscosity is practically the same in the whole concentration range studied. The present results for urea and thiourea aqueous solutions are compared with those previously obtained for amide- water systems. (author)

  5. Laser photoelectron spectroscopy of MnH - 2, FeH - 2, CoH - 2, and NiH - 2: Determination of the electron affinities for the metal dihydrides

    Science.gov (United States)

    Miller, Amy E. S.; Feigerle, C. S.; Lineberger, W. C.

    1986-04-01

    The laser photoelectron spectra of MnH-2, FeH-2, CoH-2, and NiH-2 and the analogous deuterides are reported. Lack of vibrational structure in the spectra suggests that all of the dihydrides and their negative ions have linear geometries, and that the transitions observed in the spectra are due to the loss of nonbonding d electrons. The electron affinities for the metal dihydrides are determined to be 0.444±0.016 eV for MnH2, 1.049±0.014 eV for FeH2, 1.450±0.014 eV for CoH2, and 1.934±0.008 eV for NiH2. Electronic excitation energies are provided for excited states of FeH2, CoH2, and NiH2. Electron affinities and electronic excitation energies for the dideuterides are also reported. A limit on the electron affinity of CrH2 of ≥2.5 eV is determined. The electron affinities of the dihydrides directly correlate with the electron affinities of the high-spin states of the monohydrides, and with the electron affinities of the metal atoms. These results are in agreement with a qualitative model developed for bonding in the monohydrides.

  6. Magnetic structure and phase transitions of Co1-xMnxCl2.2H2O and Co1-xMnxCl2.2D2O

    International Nuclear Information System (INIS)

    Brueckel, T.; Lippert, M.; Kubo, H.; Zenmyo, K.; Mayer, H.M.; Pfeiffer, F.; Hohlwein, D.; Krimmel, A.

    1995-01-01

    We present neutron diffraction results of the magnetic structure, phase transitions and magnetic short-range order of Co 1-x Mn x Cl 2 .2H 2 O/D 2 O single crystals. For samples in an intermediate composition range, where a spin glass phase exists, we found the coexistence of spin glass and long-range antiferromagnetic order. ((orig.))

  7. Theoretical studies of molecule surface scattering: Rotationally inelastic diffraction and dissociative dynamics of H2 on metals

    International Nuclear Information System (INIS)

    Cruz Pol, A.J.

    1993-01-01

    The interaction of H 2 and its isotopes with metal surfaces has been the subject of many investigations. The scattering experiments provide data such as the final rotational state distribution, sticking coefficients, kinetic energy distribution, and diffraction data. In the first study of this thesis the author implemented a model for looking at the rotationally inelastic diffraction probabilities for H 2 , HD, and D 2 , as a function of surface temperature. The surface is treated in a quantum mechanical fashion using a recently developed formalism. The center of mass translational motion is treated semiclassically using Gaussian wave packets, and the rotations are described quantum mechanically. The phonon summed rotation-diffraction probabilities as well as the probability distribution for a scattering molecule exchanging an amount of energy ΔE with the surface were computed. In the second and third study of this thesis the author implemented a mixed quantum-classical model to compute the probability for dissociation and rotational excitation for H 2 , HD, and D 2 scattered from Ni(100) dimensionally in dynamics simulations. Of the six degrees of freedom for the dissociative adsorption of a diatomic molecule on a static surface, the author treats Z,d the center of mass distance above the surface plan, r, the internuclear separation, θ, the polar orientation angle, quantum mechanically. The remaining three degrees of freedom, X and Y, the center of mass position on the surface plane, and oe, the azimuthal orientation angle, are treated classically. Probabilities for dissociation and ro-vibrational excitation are computed as a function of incident translational energy. Two sudden approximations are tested, in which either the center of mass translation parallel to the surface or the azimuthal orientation of the molecule are frozen. Comparisons are made between low and high dimensionality results and with fully classical results

  8. Betaine Phosphate (CH3)3N+CH2COO-.H3PO4 Modification Using D2O

    International Nuclear Information System (INIS)

    Saryati; Ridwan; Deswita; Sugiantoro, Sugik

    2002-01-01

    Betaine fosfate (CH 3 ) 3 N + CH 2 COO - .H 3 PO 4 modification by using D 2 O has been studied. This modification was carried out by slowly evaporation the saturated Betaine phosphat in the D 2 O solution in the dry box at 40 o C, until the dry crystal were formed. Based on the NMR data, can be concluded that the exchange process with D has been runed well and Betaine phosphate-D (CH 3 ) 3 N + CH 2 COO - .H 3 PO 4 has been resulted. From the X-ray diffraction pattern data can be concluded that there are a deference in the crystal structure between Betaine phosphate and Betaine phosphate modification result. From the Differential Scanning Colorimeter (DSC) diagram at the range temperature from 30 o C to 250 o C, can be shown that the Betaine phosphate-H has two endothermic transition phase, at 99 o C with a very little adsorbed calor and at 221.50 o C with -26.75 cal/g. Modified Betaine phosphate has also two endothermic transition phase, at 99.86 o C with -1.94 cal/g and at 171.01 o C with -3.48 cal/g. It can be conclosed that the D atom substitution on the H atoms in Betaine phosphate, to change the crystal and the endothermic fase temperature and energy

  9. Experimental and theoretical study of rotationally inelastic diffraction of H{sub 2}(D{sub 2}) from methyl-terminated Si(111)

    Energy Technology Data Exchange (ETDEWEB)

    Nihill, Kevin J.; Hund, Zachary M.; Sibener, S. J., E-mail: s-sibener@uchicago.edu [The James Franck Institute and Department of Chemistry, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637 (United States); Muzas, Alberto; Cueto, Marcos del [Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Díaz, Cristina [Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid (Spain); Frankcombe, Terry [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra ACT 2610 (Australia); Plymale, Noah T.; Lewis, Nathan S. [Division of Chemistry and Chemical Engineering, Beckman Institute and Kavli Nanoscience Institute, California Institute of Technology, 210 Noyes Laboratory, 127-72, Pasadena, California 91125 (United States); Martín, Fernando [Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, 28049 Madrid (Spain)

    2016-08-28

    Fundamental details concerning the interaction between H{sub 2} and CH{sub 3}–Si(111) have been elucidated by the combination of diffractive scattering experiments and electronic structure and scattering calculations. Rotationally inelastic diffraction (RID) of H{sub 2} and D{sub 2} from this model hydrocarbon-decorated semiconductor interface has been confirmed for the first time via both time-of-flight and diffraction measurements, with modest j = 0 → 2 RID intensities for H{sub 2} compared to the strong RID features observed for D{sub 2} over a large range of kinematic scattering conditions along two high-symmetry azimuthal directions. The Debye-Waller model was applied to the thermal attenuation of diffraction peaks, allowing for precise determination of the RID probabilities by accounting for incoherent motion of the CH{sub 3}–Si(111) surface atoms. The probabilities of rotationally inelastic diffraction of H{sub 2} and D{sub 2} have been quantitatively evaluated as a function of beam energy and scattering angle, and have been compared with complementary electronic structure and scattering calculations to provide insight into the interaction potential between H{sub 2} (D{sub 2}) and hence the surface charge density distribution. Specifically, a six-dimensional potential energy surface (PES), describing the electronic structure of the H{sub 2}(D{sub 2})/CH{sub 3}−Si(111) system, has been computed based on interpolation of density functional theory energies. Quantum and classical dynamics simulations have allowed for an assessment of the accuracy of the PES, and subsequently for identification of the features of the PES that serve as classical turning points. A close scrutiny of the PES reveals the highly anisotropic character of the interaction potential at these turning points. This combination of experiment and theory provides new and important details about the interaction of H{sub 2} with a hybrid organic-semiconductor interface, which can be used

  10. GC-MS and GC-MS/MS measurement of ibuprofen in 10-μL aliquots of human plasma and mice serum using [α-methylo-2H3]ibuprofen after ethyl acetate extraction and pentafluorobenzyl bromide derivatization: Discovery of a collision energy-dependent H/D isotope effect and pharmacokinetic application to inhaled ibuprofen-arginine in mice.

    Science.gov (United States)

    Tsikas, Dimitrios; Kayacelebi, Arslan Arinc; Hanff, Erik; Mitschke, Anja; Beckmann, Bibiana; Tillmann, Hanns-Christian; Gutzki, Frank-Mathias; Müller, Meike; Bernasconi, Corrado

    2017-02-01

    GC-MS and GC-MS/MS methods were developed and validated for the quantitative determination of ibuprofen (d 0 -ibuprofen), a non-steroidal anti-inflammatory drug (NSAID), in human plasma using α-methyl- 2 H 3 -4-(isobutyl)phenylacetic acid (d 3 -ibuprofen) as internal standard. Plasma (10μL) was diluted with acetate buffer (80μL, 1M, pH 4.9) and d 0 - and d 3 -ibuprofen were extracted with ethyl acetate (2×500μL). After solvent evaporation d 0 - and d 3 -ibuprofen were derivatized in anhydrous acetonitrile by using pentafluorobenzyl (PFB) bromide and N,N-diisopropylethylamine as the base catalyst. Under electron-capture negative-ion chemical ionization (ECNICI), the PFB esters of d 0 - and d 3 -ibuprofen readily ionize to form their carboxylate anions [M-PFB] - at m/z 205 and m/z 208, respectively. Collision-induced dissociation (CID) of m/z 205 and m/z 208 resulted in the formation of the anions at m/z 161 and m/z 164, respectively, due to neutral loss of CO 2 (44 Da). A collision energy-dependent H/D isotope effect was observed, which involves abstraction/elimination of H - from d 0 -ibuprofen and D - from d 3 -ibuprofen and is minimum at a CE value of 5eV. Quantitative GC-MS determination was performed by selected-ion monitoring of m/z 205 and m/z 208. Quantitative GC-MS/MS determination was performed by selected-reaction monitoring of the mass transitions m/z 205 to m/z 161 for d 0 -ibuprofen and m/z 208 to m/z 164 for d 3 -ibuprofen. In a therapeutically relevant concentration range (0-1000μM) d 0 -ibuprofen added to human plasma was determined with accuracy (recovery, %) and imprecision (relative standard deviation, %) ranging between 93.7 and 110%, and between 0.8 and 4.9%, respectively. GC-MS (y) and GC-MS/MS (x) yielded almost identical results (y=4.00+0.988x, r 2 =0.9991). In incubation mixtures of arachidonic acid (10μM), d 3 -ibuprofen (10μM) or d 0 -ibuprofen (10μM) with ovine cyclooxygenase (COX) isoforms 1 and 2, the concentration of d 3

  11. Time-resolved investigations of the fragmentation dynamic of H2 (D2) in and with ultra-short laser pulses

    International Nuclear Information System (INIS)

    Ergler, T.

    2006-01-01

    In course of this work pump-probe experiments aimed to study ultrafast nuclear motion in H 2 (D 2 ) fragmentation by intense 6-25 fs laser pulses have been carried out. In order to perform time-resolved measurements, a Mach-Zehnder interferometer providing two identical synchronized laser pulses with the time-delay variable from 0 to 3000 fs with 300 as accuracy and long-term stability has been built. The laser pulses at the intensities of up to 10 15 W/cm 2 were focused onto a H 2 (D 2 ) molecular beam leading to the ionization or dissociation of the molecules, and the momenta of all charged reactions fragments were measured with a reaction microscope. With 6-7 fs pulses it was possible to probe the time evolution of the bound H + 2 (D + 2 ) nuclear wave packet created by the first (pump) laser pulse, fragmenting the molecule with the second (probe) pulse. A fast delocalization, or ''collapse'', and subsequent ''revival'' of the vibrational wave packet have been observed. In addition, the signatures of the ground state vibrational excitation in neutral D 2 molecule have been found, and the dominance of a new, purely quantum mechanical wave packet preparation mechanism (the so-called ''Lochfrass'') has been proved. In the experiments with 25 fs pulses the theoretically predicted enhancement of the ionization probability for the dissociating H + 2 molecular ion at large internuclear distances has been detected for the first time. (orig.)

  12. DISEQUILIBRIUM CARBON, OXYGEN, AND NITROGEN CHEMISTRY IN THE ATMOSPHERES OF HD 189733b AND HD 209458b

    International Nuclear Information System (INIS)

    Moses, Julianne I.; Visscher, C.; Fortney, J. J.; Showman, A. P.; Lewis, N. K.; Griffith, C. A.; Klippenstein, S. J.; Shabram, M.; Friedson, A. J.; Marley, M. S.; Freedman, R. S.

    2011-01-01

    We have developed a one-dimensional photochemical and thermochemical kinetics and diffusion model to study the effects of disequilibrium chemistry on the atmospheric composition of 'hot-Jupiter' exoplanets. Here we investigate the coupled chemistry of neutral carbon, hydrogen, oxygen, and nitrogen species on HD 189733b and HD 209458b and we compare the model results with existing transit and eclipse observations. We find that the vertical profiles of molecular constituents are significantly affected by transport-induced quenching and photochemistry, particularly on the cooler HD 189733b; however, the warmer stratospheric temperatures on HD 209458b help maintain thermochemical equilibrium and reduce the effects of disequilibrium chemistry. For both planets, the methane and ammonia mole fractions are found to be enhanced over their equilibrium values at pressures of a few bar to less than an mbar due to transport-induced quenching, but CH 4 and NH 3 are photochemically removed at higher altitudes. Disequilibrium chemistry also enhances atomic species, unsaturated hydrocarbons (particularly C 2 H 2 ), some nitriles (particularly HCN), and radicals like OH, CH 3 , and NH 2 . In contrast, CO, H 2 O, N 2 , and CO 2 more closely follow their equilibrium profiles, except at pressures ∼ 2 O, and N 2 are photochemically destroyed and CO 2 is produced before its eventual high-altitude destruction. The enhanced abundances of CH 4 , NH 3 , and HCN are expected to affect the spectral signatures and thermal profiles of HD 189733b and other relatively cool, transiting exoplanets. We examine the sensitivity of our results to the assumed temperature structure and eddy diffusion coefficients and discuss further observational consequences of these models.

  13. Bound energy levels at the n=2 dissociation threshold in HD

    NARCIS (Netherlands)

    Pielage, T.G.P.; de Lange, A.; Brandi, F.; Ubachs, W.M.G.

    2002-01-01

    Level energies of g symmetry states lying just below the n = 2 dissociation threshold have been determined in a XUV + IR multi-step laser excitation experiment in HD, with an absolute accuracy of the excitation energy of 0.015 cm

  14. File list: NoD.Emb.50.AllAg.2-4h_embryos [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Emb.50.AllAg.2-4h_embryos dm3 No description Embryo 2-4h embryos ERX008189,ERX0...08195,ERX008192,ERX008185 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/NoD.Emb.50.AllAg.2-4h_embryos.bed ...

  15. Testing the early Mars H2-CO2 greenhouse hypothesis with a 1-D photochemical model

    Science.gov (United States)

    Batalha, Natasha; Domagal-Goldman, Shawn D.; Ramirez, Ramses; Kasting, James F.

    2015-09-01

    A recent study by Ramirez et al. (Ramirez, R.M. et al. [2014]. Nat. Geosci. 7(1), 59-63. http://www.nature.com/doifinder/10.1038/ngeo2000 (accessed 16.09.14)) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of water. Such warm temperatures appear necessary to generate the rainfall (or snowfall) amounts required to carve the ancient martian valleys. Here, we use our best estimates for early martian outgassing rates, along with a 1-D photochemical model, to assess the conversion efficiency of CO, CH4, and H2S to CO2, SO2, and H2. Our outgassing estimates assume that Mars was actively recycling volatiles between its crust and interior, as Earth does today. H2 production from serpentinization and deposition of banded iron-formations is also considered. Under these assumptions, maintaining an H2 concentration of ˜1-2% by volume is achievable, but reaching 5% H2 requires additional H2 sources or a slowing of the hydrogen escape rate below the diffusion limit. If the early martian atmosphere was indeed H2-rich, we might be able to see evidence of this in the rock record. The hypothesis proposed here is consistent with new data from the Curiosity Rover, which show evidence for a long-lived lake in Gale Crater near Mt. Sharp. It is also consistent with measured oxygen fugacities of martian meteorites, which show evidence for progressive mantle oxidation over time.

  16. Evidence for H2/D2 isotope effects on Fischer-Tropsch synthesis over supported ruthenium catalysts

    International Nuclear Information System (INIS)

    Kellner, C.S.; Bell, A.T.

    1981-01-01

    The effects of using D 2 rather than H 2 during Fischer-Tropsch synthesis were investigated using alumina- and silica-supported Ru catalysts. For the alumina-supported catalysts, the rate of CD 4 formation was 1.4 to 1.6 times faster than the formation of CH 4 . A noticeable isotope effect was also observed for higher molecular weight products. The magnitude of the isotope effects observed using the silica-supported catalyst was much smaller than that found using the alumina-supported catalysts. The formation of olefins relative to paraffins was found to be higher when H 2 rather than D 2 was used, independent of the catalyst support. The observed isotope effects are explained in terms of a mechanism for CO hydrogenation and are shown to arise from a complex combination of the kinetic and equilibrium isotope effects associated with elementary processes occurring on the catalyst surface

  17. Neutral interstellar gas toward epsilon persei: H I, H2, D I, N I, O I

    International Nuclear Information System (INIS)

    Vidal, A.; Ferlet, R.; Laurent, C.; York, D.G.

    1982-01-01

    The study of the interstellar medium toward epsilon Per, a moderately reddened (E/sub B/-V = 0.1) B0.5 star, through the analysis of H I, D I, H 2 , N I, O I, and Ar I absorption features, revealed the following structure of the line of sight: (1) a main interstellar, cold (Tapprox.100 K; b = 2.9 km s -1 ) component, (2) a weak (approx.1% of the main one) probably cold component, and (3) a weak (also approx.1% of the main one) and hot component (Tapprox.8000 K). All three components have normal abundances. Comparison with ground-based observations or other UV studies reveals the presence on the line of sight of an H II region not detected in the neutral species observed in this study. High-velocity H I gas is also detected, located either in the interstellar medium or very likely in the stellar wind for the blue-shifted components. One of these features is blended with the deuterium lines and therefore obscures our D/H evaluation. All we can say is that the data are compatible with a D/H ratio equal to 1.5 x 10 -5 . This blended feature proved to vary by at least a factor of 3 in column density within few hours, a result which sustains our interpretation of the stellar wind origin of the blueshifted high-velocity H I component. However, the alternative interpretation of a high D/H (approx.10 -4 ) value is also compatible with our data

  18. H-Ransac a Hybrid Point Cloud Segmentation Combining 2d and 3d Data

    Science.gov (United States)

    Adam, A.; Chatzilari, E.; Nikolopoulos, S.; Kompatsiaris, I.

    2018-05-01

    In this paper, we present a novel 3D segmentation approach operating on point clouds generated from overlapping images. The aim of the proposed hybrid approach is to effectively segment co-planar objects, by leveraging the structural information originating from the 3D point cloud and the visual information from the 2D images, without resorting to learning based procedures. More specifically, the proposed hybrid approach, H-RANSAC, is an extension of the well-known RANSAC plane-fitting algorithm, incorporating an additional consistency criterion based on the results of 2D segmentation. Our expectation that the integration of 2D data into 3D segmentation will achieve more accurate results, is validated experimentally in the domain of 3D city models. Results show that HRANSAC can successfully delineate building components like main facades and windows, and provide more accurate segmentation results compared to the typical RANSAC plane-fitting algorithm.

  19. The energy dependence of selective hydrogen atom abstraction by H(D) atoms in the photolysis of neopentane - ethane mixtures at 77 K

    International Nuclear Information System (INIS)

    Miyazaki, T.; Fueki, K.

    1980-01-01

    Selective hydrogen - atom - abstraction reaction by H or D atom has been studied in a neo C 5 H 12 - C 2 H 6 (less than 1 mol %) mixture at 77 K by ESR spectroscopy. The H (or D) atom produced by the photolysis of HI (or DI) reacts with neo - C 2 H 12 and C 2 H 6 to form neo - C 5 H 11 and C 2 H 5 radicals. In order to obtain H atoms with different kinetic energies, the photolysis was performed with different lights of 313, 254 and 229 nm. The selective formation of the C 2 H 5 radical by the reaction of the H (or D) atom with C 2 H 6 becomes more effective with the decrease in the energy of the H (or D) atom. The formation of the neo - C 5 H 11 radical by the reaction of the H (or D) atom with neo - C 2 H 12 becomes more effective with the increase in the energy of the H (or D) atom. (A.R.H.) [pt

  20. Exploring the dynamics of reaction N((2)D)+C2H4 with crossed molecular-beam experiments and quantum-chemical calculations.

    Science.gov (United States)

    Lee, Shih-Huang; Chin, Chih-Hao; Chen, Wei-Kan; Huang, Wen-Jian; Hsieh, Chu-Chun

    2011-05-14

    We conducted the title reaction using a crossed molecular-beam apparatus, quantum-chemical calculations, and RRKM calculations. Synchrotron radiation from an undulator served to ionize selectively reaction products by advantage of negligibly small dissociative ionization. We observed two products with gross formula C(2)H(3)N and C(2)H(2)N associated with loss of one and two hydrogen atoms, respectively. Measurements of kinetic-energy distributions, angular distributions, low-resolution photoionization spectra, and branching ratios of the two products were carried out. Furthermore, we evaluated total branching ratios of various exit channels using RRKM calculations based on the potential-energy surface of reaction N((2)D)+C(2)H(4) established with the method CCSD(T)/6-311+G(3df,2p)//B3LYP/6-311G(d,p)+ZPE[B3LYP/6-311G(d,p)]. The combination of experimental and computational results allows us to reveal the reaction dynamics. The N((2)D) atom adds to the C=C π-bond of ethene (C(2)H(4)) to form a cyclic complex c-CH(2)(N)CH(2) that directly ejects a hydrogen atom or rearranges to other intermediates followed by elimination of a hydrogen atom to produce C(2)H(3)N; c-CH(2)(N)CH+H is the dominant product channel. Subsequently, most C(2)H(3)N radicals, notably c-CH(2)(N)CH, further decompose to CH(2)CN+H. This work provides results and explanations different from the previous work of Balucani et al. [J. Phys. Chem. A, 2000, 104, 5655], indicating that selective photoionization with synchrotron radiation as an ionization source is a good choice in chemical dynamics research.

  1. N-(4-Bromobenzyl-2-(5,6-dimethyl-1H-benzo[d]imid-azol-2-ylbenzeneamine

    Directory of Open Access Journals (Sweden)

    Monika Dziełak

    2018-01-01

    Full Text Available N-(4-Bromobenzyl-2-(5,6-dimethyl-1H-benzo[d]imidazol-2-ylbenzeneamine was obtained by condensation of N-(4-bromobenzyl-3,1-benzoxazine-2,4-dione (N-(4-bromobenzylisatoic anhydride with 4,5-dimethyl-1,2-phenylenediamine in refluxing acetic acid. This is a rare example of condensation of N-substituted 3,1-benzoxazine-2,4-dione with 1,2-phenylenediamine, which resulted in the formation of a benzimidazole derivative with a moderate yield. Crystallographic studies and initial biological screening were performed for the obtained product.

  2. Hydrothermal synthesis, structural elucidation, spectroscopic studies, thermal behavior and luminescence properties of a new 3-d compound: FeAlF2(C10H8N2)(HPO4)2(H2O)

    Science.gov (United States)

    Bouzidia, Nabaa; Salah, Najet; Hamdi, Besma; Ben Salah, Abdelhamid

    2017-04-01

    The study of metal phosphate has been a proactive field of research thanks to its applied and scientific importance, especially in terms of the development of optical devices such as solid state lasers as well as optical fibers. The present paper seeks to investigate the synthesis, crystal structure, elemental analysis and properties of FeAlF2(C10H8N2)(HPO4)2(H2O) compound investigated by spectroscopic studies (FT-IR and FT-Raman), thermal behavior and luminescence. The Hirshfeld surface analysis and 2-D fingerprint plot have been performed to explore the behavior of these weak interactions and crystal cohesion. This investigation shows that the molecules are connected by hydrogen bonds of the type Osbnd H⋯O and Osbnd H⋯F. In addition, the 2,2'‒bipyridine ligand plays a significant role in the construction of 3-D supramolecular framework via π‒π stacking. FT‒IR and FT‒Raman spectra were used so as to ease the responsibilities of the vibration modes of the title compound. The thermal analysis (TGA) study shows a mass loss evolution as a temperature function. Finally, the optical properties were evaluated by photoluminescence spectroscopy.

  3. Use of hydrogen-deuterium exchange for contrast in {sup 1}H NMR microscopy investigations of an operating PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Feindel, Kirk W.; Bergens, Steven H.; Wasylishen, Roderick E. [Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alta. T6G 2G2 (Canada)

    2007-11-08

    The use of hydrogen-deuterium (H-D) exchange as a method to introduce contrast in {sup 1}H NMR microscopy images and to investigate the dynamic distribution of water throughout an operating H{sub 2}/O{sub 2} polymer electrolyte membrane fuel cell, PEMFC, is demonstrated. Cycling D{sub 2}O(l) through the flow channels of a PEMFC causes H-D exchange with water in the PEM to result in a D{sub 2}O-saturated PEM and thus concomitant removal of the {sup 1}H NMR signal. Subsequent operation of the PEMFC with H{sub 2}(g) enables visualization of the redistribution of water from wet or flooded conditions as H-D exchange occurs with D{sub 2}O in the PEM and results in recovery of the {sup 1}H NMR signal. Alternating between H{sub 2}(g) and D{sub 2}(g) as fuel allows observation of water distributions in the PEM while the cell is operating at a steady-state under low relative humidity. At similar currents, the rate of observable H-D exchange in the PEM during fuel cell operation was faster when the PEM was saturated with water than when under low relative humidity. These results are consistent with the known proportions of the conductive hydrophilic and nonconductive hydrophobic domains of Nafion when exposed to different relative humidities. (author)

  4. THE CHEMISTRY OF VIBRATIONALLY EXCITED H2 IN THE INTERSTELLAR MEDIUM

    International Nuclear Information System (INIS)

    Agundez, M.; Roueff, E.; Goicoechea, J. R.; Cernicharo, J.; Faure, A.

    2010-01-01

    The internal energy available in vibrationally excited H 2 molecules can be used to overcome or diminish the activation barrier of various chemical reactions of interest for molecular astrophysics. In this paper, we investigate in detail the impact on the chemical composition of interstellar clouds of the reactions of vibrationally excited H 2 with C + , He + , O, OH, and CN, based on the available chemical kinetics data. It is found that the reaction of H 2 (v>0) and C + has a profound impact on the abundances of some molecules, especially CH + , which is a direct product and is readily formed in astronomical regions with fractional abundances of vibrationally excited H 2 , relative to the ground state H 2 , in excess of ∼10 -6 , independently of whether the gas is hot or not. The effects of these reactions on the chemical composition of the diffuse clouds ζOph and HD 34078, the dense photon-dominated region (PDR) Orion Bar, the planetary nebula NGC 7027, and the circumstellar disk around the B9 star HD 176386 are investigated through PDR models. We find that formation of CH + is especially favored in dense and highly FUV illuminated regions such as the Orion Bar and the planetary nebula NGC 7027, where column densities in excess of 10 13 cm -2 are predicted. In diffuse clouds, however, this mechanism is found to be not efficient enough to form CH + with a column density close to the values derived from astronomical observations.

  5. Dopamine D2 receptor radiotracers [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Patrick N. [Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada)], E-mail: patrick.mccormick@camhpet.ca; Kapur, Shitij [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Seeman, Philip [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Department of Pharmacology, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Wilson, Alan A. [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2008-01-15

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [{sup 11}C](+)-PHNO ([{sup 11}C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [{sup 3}H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for {sup 11}C and {sup 3}H. The specific binding ratio {l_brace}SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum){r_brace} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs responded indistinguishably in terms of both ED{sub 50} and Hill slope (e.g., (-)-NPA ED{sub 50} values are 0.027 and 0.023 mg/kg for [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride, respectively). In response to AMPH challenge, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [{sup 11}C](+)-PHNO- and [{sup 3}H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo

  6. Evidence of diketopiperazine and oxazolone structures for HA b2+ ion.

    Science.gov (United States)

    Perkins, Brittany R; Chamot-Rooke, Julia; Yoon, Sung Hwan; Gucinski, Ashley C; Somogyi, Arpád; Wysocki, Vicki H

    2009-12-09

    Peptide fragmentation can lead to an oxazolone or diketopiperazine b(2)(+) ion structure. IRMPD spectroscopy combined with computational modeling and gas-phase H/D exchange was used to study the structure of the b(2)(+) ion from protonated HAAAA. The experimental spectrum of the b(2)(+) ion matches both the experimental spectrum for the protonated cyclic dipeptide HA (a commercial diketopiperazine) and the theoretical spectrum for a diketopiperazine protonated at the imidazole pi nitrogen. A characteristic band at 1875 cm(-1) and increased abundance of the peaks at 1619 and 1683 cm(-1) indicate a second population corresponding to an oxazolone species. H/D exchange also shows a mixture of two populations consistent with a mixture of b(2)(+) ion diketopiperazine and oxazolone structures.

  7. Simultaneous Laser Raman-rayleigh-lif Measurements and Numerical Modeling Results of a Lifted Turbulent H2/N2 Jet Flame in a Vitiated Coflow

    Science.gov (United States)

    Cabra, R.; Chen, J. Y.; Dibble, R. W.; Myhrvold, T.; Karpetis, A. N.; Barlow, R. S.

    2002-01-01

    An experiment and numerical investigation is presented of a lifted turbulent H2/N2 jet flame in a coflow of hot, vitiated gases. The vitiated coflow burner emulates the coupling of turbulent mixing and chemical kinetics exemplary of the reacting flow in the recirculation region of advanced combustors. It also simplifies numerical investigation of this coupled problem by removing the complexity of recirculating flow. Scalar measurements are reported for a lifted turbulent jet flame of H2/N2 (Re = 23,600, H/d = 10) in a coflow of hot combustion products from a lean H2/Air flame ((empty set) = 0.25, T = 1,045 K). The combination of Rayleigh scattering, Raman scattering, and laser-induced fluorescence is used to obtain simultaneous measurements of temperature and concentrations of the major species, OH, and NO. The data attest to the success of the experimental design in providing a uniform vitiated coflow throughout the entire test region. Two combustion models (PDF: joint scalar Probability Density Function and EDC: Eddy Dissipation Concept) are used in conjunction with various turbulence models to predict the lift-off height (H(sub PDF)/d = 7,H(sub EDC)/d = 8.5). Kalghatgi's classic phenomenological theory, which is based on scaling arguments, yields a reasonably accurate prediction (H(sub K)/d = 11.4) of the lift-off height for the present flame. The vitiated coflow admits the possibility of auto-ignition of mixed fluid, and the success of the present parabolic implementation of the PDF model in predicting a stable lifted flame is attributable to such ignition. The measurements indicate a thickened turbulent reaction zone at the flame base. Experimental results and numerical investigations support the plausibility of turbulent premixed flame propagation by small scale (on the order of the flame thickness) recirculation and mixing of hot products into reactants and subsequent rapid ignition of the mixture.

  8. Experimental investigation of H2/D2 isotope separation by cryo-adsorption in metal-organic frameworks

    International Nuclear Information System (INIS)

    Teufel, Julia Sonja

    2012-01-01

    Light-gas isotopes differ in their adsorption behavior under cryogenic conditions in nanoporous materials due to their difference in zero-point energy. However, the applicability of these cryo-effects for the separation of isotope mixtures is still lacking an experimental proof. The current work describes the first experimentally obtained H 2 /D 2 selectivity values of nanoporous materials measured by applying isotope mixtures in low-temperature thermal desorption spectroscopy (TDS). The dissertation contains the following key points: 1) A proof of the experimental method, i.e. it is shown that TDS leads to reasonable selectivity values. 2) A series of small-pore MFU-4 derivatives (MOFs) is shown to separate isotope mixtures by quantum sieving, i.e. by the difference in the adsorption kinetics. The influence of the pore size on the selectivity is studied systematically for this series. 3) Two MOFs with pores much larger than the kinetic diameter of H 2 do not exhibit kinetic quantum sieving. However, if the MOFs are exposed to an isotope mixture, deuterium adsorbs preferentially at the adsorption sites with high heats of adsorption. According to the experimental results, these strong adsorption sites can be every selective for deuterium. On the basis of the experimentally obtained selectivity values, technical implementations for H 2 /D 2 light-gas isotope separation by cryo-adsorption are described.

  9. Facial One-Pot Synthesis of D 3h Symmetric Bicyclocalix[2]arene[2]triazines and Their Layered Comb Self-Assembly

    KAUST Repository

    Chen, Yin

    2017-11-23

    A number of D3h symmetric bicyclocalix[2]arene[2]triazine core compounds were synthesized via a general and good-yielding (43-48% yield) facile protocol starting from cyanuric halides, phloroglucinol and K2CO3 under very mild reaction conditions. These cage-like compounds are tolerate with different reaction conditions and can be derived with other functional groups in high yield. The X-ray crystal structures show these compounds have slightly distorted D3h symmetric structures. Due to the unique molecular topological structure, bicyclocalix[2]arene[2]triazine molecules form unique layered comb networks when hydrogen bond groups exist (such as CO2H, B(OH)2), which represent a new kind of building block unit for supramolecular architectures.

  10. T20 measurements for 1H(d searrow,γ)3He and the P-wave component of the nucleon-nucleon force

    International Nuclear Information System (INIS)

    Schmid, G.J.; Chasteler, R.M.; Weller, H.R.; Tilley, D.R.; Fonseca, A.C.; Lehman, D.R.

    1996-01-01

    Measurements of T 20 (θ lab =90 degree) for 1 H(d searrow,γ) 3 He, in the energy range E d (lab)=12.7 endash 19.8 MeV, have been compared with the results of new exact three-body Faddeev calculations using the Paris and Bonn-A nucleon-nucleon (NN) potentials. This comparison indicates a strong sensitivity of the T 20 observable to the p-wave part of the NN force. In particular, we find that the 3 P 1 component of the P-wave interaction is the dominant P-wave term affecting the value of T 20 (θ lab =90 degree) at these energies. This contrasts with the results of polarized N-D scattering studies where the 3 P 0 component has been found to dominate. cents 1996 The American Physical Society

  11. Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

    International Nuclear Information System (INIS)

    Song, Yuan; Wu, Keqiang; Dhaubhadel, Sangeeta; An, Lizhe; Tian, Lining

    2010-01-01

    DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

  12. Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yuan [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); Wu, Keqiang [Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan (China); Dhaubhadel, Sangeeta [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); An, Lizhe, E-mail: lizhean@lzu.edu.cn [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Tian, Lining, E-mail: tianl@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada)

    2010-05-28

    DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

  13. Spectroscopic diagnostics of the vibrational population in the ground state of H2 and D2 molecules

    International Nuclear Information System (INIS)

    Fantz, U.; Heger, B.

    1998-01-01

    A diagnostic method has been evaluated for measuring the relative vibrational ground-state population of molecular hydrogen and deuterium. It is based on the analysis of the diagonal Fulcher bands · 3 Π u →a 3 Σ g + ) and the Franck-Condon principle of excitation. The validity of the underlying assumptions was verified by experiments in microwave discharges and the method is recommended for application in divertor plasmas in controlled fusion experiments. By attributing a vibrational temperature T vib to the ground-state electronic level (X 1 Σ g + ) and assuming population via the Franck-Condon principle, the upper Fulcher state vibrational distribution can be derived theoretically with T vib as parameter. Comparison with experimentally derived upper-state population gives the corresponding T vib of the ground state. The Franck-Condon factors for the · 3 Π 1 Σ g + and · 3 Π u →a 3 Σ g + transitions have been calculated for both hydrogen and deuterium from molecular constants using the FCFRKR code. The method has been applied to low pressure H 2 /He and D 2 /He microwave plasmas, showing good agreement of experimentally and theoretically derived upper Fulcher state vibrational distributions. The vibrational temperatures range from 3200 K to 6800 K for H 2 and 2600 K to 4000 K for D 2 · depending on molecular density, pressure and electron temperature, but indicating nearly the same vibrational population for H 2 and D 2 for comparable plasma conditions. (author)

  14. (Solid + liquid) phase equilibria of (Ca(H2PO2)2 + CaCl2 + H2O) and (Ca(H2PO2)2 + NaH2PO2 + H2O) ternary systems at T = 323.15 K

    International Nuclear Information System (INIS)

    Cao, Hong-yu; Zhou, Huan; Bai, Xiao-qin; Ma, Ruo-xin; Tan, Li-na; Wang, Jun-min

    2016-01-01

    Graphical abstract: Solubility diagram of the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system at T = (323.15 and 298.15) K. - Highlights: • Phase diagrams of Ca 2+ -H 2 PO 2 − -Cl − -H 2 O, Ca 2+ -Na + -H 2 PO 2 − -H 2 O at 323.15 K were obtained. • Incompatible double salt of NaCa(H 2 PO 2 ) 3 in Ca 2+ -Na + -H 2 PO 2 − -H 2 O system was determined. • Density diagram of the corresponding liquid were simultaneously measured. - Abstract: Calcium hypophosphite has been widely used as an anti-corrosive agent, flame retardant, fertilizer, assistant for Ni electroless plating, and animal nutritional supplement. High purity calcium hypophosphite can be synthesized via the replacement reaction of sodium hypophosphite and calcium chloride. In this work, the (solid + liquid) phase equilibria of (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) and (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) ternary systems at T = 323.15 K were studied experimentally via the classical isothermal solubility equilibrium method, and the phase diagrams for these two systems were obtained. It was found that two solid salts of CaCl 2 ·2H 2 O and Ca(H 2 PO 2 ) 2 exist in the (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) system, and three salts of Ca(H 2 PO 2 ) 2 , NaH 2 PO 2 ·H 2 O and one incompatible double salt, NaCa(H 2 PO 2 ) 3 occur in the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system.

  15. High resolution emission spectra of H2 and D2 near 80 nm

    International Nuclear Information System (INIS)

    Larzilliere, M.; Roncin, J.-Y.; Launay, F.

    1980-01-01

    A few lines have been observed in the far ultraviolet emission spectrum of molecular hydrogen and deuterium. They are assigned to transitions from levels of the 3pπD 1 PIsub(u)sup(-) state, lying above the dissociation limit into H(ls) + H(n=2), near 84.5 nm, and, for some of them, above the first ionization limit near 80.4 nm, the lower state being X 1 Σsub(g)sup(+) (v''=1). This is in fair agreement with measured predissociation and preionization yields. Accurate line position measurements lead to molecular constants in very good agreement with theoretical calculations

  16. Late radiation injuries of the gastrointestinal tract in het H2 and H5 EORTC Hodgkin's disease trials

    International Nuclear Information System (INIS)

    Cosset, J.M.; Henry-Amar, M.; Burgers, J.M.V.; Noordijk, E.Ml.; Van der Schueren, E.

    1988-01-01

    Out of 516 patients who entered in the two succesive EORTC trials H2 and H5 for supra-diaphragmatic stages I and II Hodgkin's disease (HD), and who received an infra-diaphragmatic irradiation, 36 (7%) developed the late radiation injuries of the gastrointestinal tract (GIT). Twenty-five patients presented with ulcers (stomach or duodenum), 2 with severe gastritis, 6 with small bowel obstruction or perforation and 3 patients had both un ulcer and bowel obstruction. A previous laparotomy played an important role. While the complication rate was 2.7% without any previous abdominal surgery, it was 11.5% after laparotomy (p < 0.001). Fractionation was also found to be of importance in the occurrence of complications: three different weekly schedules were used - 5 x 2 Gy, 4 x 2.5 Gy and 3 x 3.3 Gy; the GIT complication rates were 4, 9 and 22%, respectively (p < 0.001). These data provide new arguments: (1) against the systematic use of laparotomy and splenectomy in the management of HD; (2) against the use of large fraction sizes (superior to 2 Gy) when irradiating those patients

  17. The D1Πu state of HD and the mass scaling relation of its predissociation widths

    Science.gov (United States)

    Dickenson, G. D.; Ubachs, W.

    2012-07-01

    Absorption spectra of HD have been recorded in the wavelength range of 75-90 nm at 100 K using the vacuum ultraviolet Fourier transform spectrometer at the Synchrotron SOLEIL. The present wavelength resolution represents an order of magnitude improvement over that of previous studies. We present a detailed study of the D1Πu-X1Σ+g system observed up to v‧ = 18. The Q-branch transition probing levels of Π- symmetry are observed as narrow resonances limited by the Doppler width at 100 K. Line positions for these transitions are determined to an estimated absolute accuracy of 0.06 cm-1. Predissociation line widths of Π+ levels are extracted from the absorption spectra. A comparison with the recent results on a study of the D1Πu state in H2 and D2 reveals that the predissociation widths scale as μ-2J(J + 1), with μ being the reduced mass of the molecule and J the rotational angular momentum quantum number, as expected from an interaction with the B‧1Σ+u continuum causing the predissociation.

  18. HypGrid2D. A 2-d mesh generator

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, N N

    1998-03-01

    The implementation of a hyperbolic mesh generation procedure, based on an equation for orthogonality and an equation for the cell face area is described. The method is fast, robust and gives meshes with good smoothness and orthogonality. The procedure is implemented in a program called HypGrid2D. The HypGrid2D program is capable of generating C-, O- and `H`-meshes for use in connection with the EllipSys2D Navier-Stokes solver. To illustrate the capabilities of the program, some test examples are shown. First a series of C-meshes are generated around a NACA-0012 airfoil. Secondly a series of O-meshes are generated around a NACA-65-418 airfoil. Finally `H`-meshes are generated over a Gaussian hill and a linear escarpment. (au)

  19. Three-dimensional WS2 nanosheet networks for H2O2 produced for cell signaling

    Science.gov (United States)

    Tang, Jing; Quan, Yingzhou; Zhang, Yueyu; Jiang, Min; Al-Enizi, Abdullah M.; Kong, Biao; An, Tiance; Wang, Wenshuo; Xia, Limin; Gong, Xingao; Zheng, Gengfeng

    2016-03-01

    Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in living RAW 264.7 macrophage cells and neurons. First-principles calculations further demonstrate that the enhanced sensitivity of probing H2O2 is attributed to the efficient and spontaneous H2O2 adsorption on WS2 nanosheet edge sites. The combined features of 3D WS2 nanosheet networks suggest attractive new opportunities for exploring the physiological roles of reactive oxygen species like H2O2 in living systems.Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in

  20. Collisional energy transfer in Na(4p--3d)--He,H2 collisions

    International Nuclear Information System (INIS)

    Kleiber, P.D.; Wong, T.H.; Bililign, S.

    1993-01-01

    We have investigated the direct collisional energy transfer process Na*(4p)+M→Na*(3d)+M, where M=He,H 2 under gas cell conditions. We have measured the temporal profiles of the Na(3d--3p) sensitized fluorescence as a function of quenching gas pressure and fit the profiles to a two-state rate equation model to obtain the quenching rate coefficients from the Na*(4p) state. The total energy transfer rate coefficient out of the 4p state for He is small [(0.5±0.2)x10 -10 cm 3 /s]. The total quenching rate coefficient out of the 4p state is much larger for H 2 [(3.9±0.5)x10 -10 cm 3 /s]. Evidence suggests that the energy transfer rate coefficient for the 4p--3d process is ∼2.0x10 -10 cm 3 /s with the remainder of the 4p quenching being predominantly reactive. We also compare the far-red wing absorption line shapes for the NaHe and NaH 2 systems

  1. Time resolved spectroscopic investigation of SiD2 + D2: kinetic study

    Science.gov (United States)

    Al-Rubaiey, Najem A.; Walsh, Robin

    2017-03-01

    Silylenes (silanediyls) have made an important impact on organosilicon chemistry even if it is of more recent foundation than carbenes in organic chemistry and much less complete. These species are highly reactive intermediates. They play a central role in the chemical vapour deposition (CVD) of various silicon-containing thin films which have a technological importance in microelectronics as well as in the dry etching processes of silicon wafers. Spectroscopic methods have been developed to observe these species, a necessary pre-requisite to their direct monitoring. In this work, deuterated phenylsilane precursor, PhSiD3 was chosen for SiD2 because its analogue phenylsilane, PhSiH3 proved to be a good precursor for SiH2 and the high quality decay signals observed revealed that SiD2 be readily detected from PhSiD3 and that if other decomposition pathways (e.g. PhSiD + D2) are occurring, they do not effect measurements of the rate constants for SiD2. The absorption spectrum of SiD2 formed from the flash photolysis of a mixture of PhSiD3 and SF6 at 193nm were found in the region 17384-17391 cm-1 with strong band at 17387.07 cm-1. This single rotational line of pQ1 was chosen to monitor SiD2 removal. Time-resolved studies of SiD2 have been carried out to obtain rate constants for its bimolecular reactions with D2. The reactions were studied over the pressure range 5-100 Torr (in SF6 bath gas) at four temperatures in the range 298-498K. Single decay from 10 photolysis laser shots were averaged and found to give reasonable first-order kinetics fits. Second order kinetics were obtained by pressure dependence of the pseudo first order decay constants and substance D2 pressures within experimental error. The reaction was found to be weakly pressure dependent at all temperatures, consistent with a third-body mediated association process. In addition, SiH2+ H2 reaction is approximately ca. 60% faster than SiD2+D2 reaction. Theoretical extrapolations (using Lindemann

  2. Time resolved spectroscopic investigation of SiD2 + D2: kinetic study

    Directory of Open Access Journals (Sweden)

    Al-Rubaiey Najem A.

    2017-01-01

    Full Text Available Silylenes (silanediyls have made an important impact on organosilicon chemistry even if it is of more recent foundation than carbenes in organic chemistry and much less complete. These species are highly reactive intermediates. They play a central role in the chemical vapour deposition (CVD of various silicon-containing thin films which have a technological importance in microelectronics as well as in the dry etching processes of silicon wafers. Spectroscopic methods have been developed to observe these species, a necessary pre-requisite to their direct monitoring. In this work, deuterated phenylsilane precursor, PhSiD3 was chosen for SiD2 because its analogue phenylsilane, PhSiH3 proved to be a good precursor for SiH2 and the high quality decay signals observed revealed that SiD2 be readily detected from PhSiD3 and that if other decomposition pathways (e.g. PhSiD + D2 are occurring, they do not effect measurements of the rate constants for SiD2. The absorption spectrum of SiD2 formed from the flash photolysis of a mixture of PhSiD3 and SF6 at 193nm were found in the region 17384-17391 cm-1 with strong band at 17387.07 cm-1. This single rotational line of pQ1 was chosen to monitor SiD2 removal. Time-resolved studies of SiD2 have been carried out to obtain rate constants for its bimolecular reactions with D2. The reactions were studied over the pressure range 5-100 Torr (in SF6 bath gas at four temperatures in the range 298-498K. Single decay from 10 photolysis laser shots were averaged and found to give reasonable first-order kinetics fits. Second order kinetics were obtained by pressure dependence of the pseudo first order decay constants and substance D2 pressures within experimental error. The reaction was found to be weakly pressure dependent at all temperatures, consistent with a third-body mediated association process. In addition, SiH2+ H2 reaction is approximately ca. 60% faster than SiD2+D2 reaction. Theoretical extrapolations (using

  3. 2D NiFe/CeO2 Basic-Site-Enhanced Catalyst via in-Situ Topotactic Reduction for Selectively Catalyzing the H2 Generation from N2HH2O.

    Science.gov (United States)

    Wu, Dandan; Wen, Ming; Gu, Chen; Wu, Qingsheng

    2017-05-17

    An economical catalyst with excellent selectivity and high activity is eagerly desirable for H 2 generation from the decomposition of N 2 H 4 ·H 2 O. Here, a bifunctional two-dimensional NiFe/CeO 2 nanocatalyst with NiFe nanoparticles (∼5 nm) uniformly anchored on CeO 2 nanosheets supports has been successfully synthesized through a dynamic controlling coprecipitation process followed by in-situ topotactic reduction. Even without NaOH as catalyst promoter, as-designed Ni 0.6 Fe 0.4 /CeO 2 nanocatalyst can show high activity for selectively catalyzing H 2 generation (reaction rate (mol N2H4 mol -1 NiFe h -1 ): 5.73 h -1 ). As ceria is easily reducible from CeO 2 to CeO 2-x , the surface of CeO 2 could supply an extremely large amount of Ce 3+ , and the high-density electrons of Ce 3+ can work as Lewis base to facilitate the absorption of N 2 H 4 , which can weaken the N-H bond and promote NiFe active centers to break the N-H bond preferentially, resulting in the high catalytic selectivity (over 99%) and activity for the H 2 generation from N 2 H 4 ·H 2 O.

  4. Neutronics comparisons of d-Li and t-H2O neutron sources

    International Nuclear Information System (INIS)

    Doran, D.G.; Cierjacks, S.; Mann, F.M.; Greenwood, L.R.; Daum, E.

    1995-01-01

    Calculations were performed to compare the neutronics of two neutron source concepts which are candidates for an international fusion materials irradiation facility (IFMIF). One concept, d-Li, produces neutrons by stopping 35 MeV deuterons in a flowing lithium target. Criticism of this concept because of the high energy tail above 14 MeV gave rise to the t-H 2 O concept proposed by Cierjacks. It would generate neutrons below 14.6 MeV ( 2 O. Test volumes that met certain damage parameter criteria were estimated. Because of the softer spectra and somewhat lower yields for t-H 2 O, the d-Li concept was found to have a test volume advantage of a factor of 2 or more, depending on the material to be irradiated. ((orig.))

  5. GaAs micromachining in the 1 H2SO4:1 H2O2:8 H2O system. From anisotropy to simulation

    Science.gov (United States)

    Tellier, C. R.

    2011-02-01

    The bulk micromachining on (010), (110) and (111)A GaAs substrates in the 1 H2SO4:1 H2O2:8 H2O system is investigated. Focus is placed on anisotropy of 3D etching shapes with a special emphasis on convex and concave undercuts which are of prime importance in the wet micromachining of mechanical structures. Etched structures exhibit curved contours and more and less rounded sidewalls showing that the anisotropy is of type 2. This anisotropy can be conveniently described by a kinematic and tensorial model. Hence, a database composed of dissolution constants is further determined from experiments. A self-elaborated simulator which works with the proposed database is used to derive theoretical 3D shapes. Simulated shapes agree well with observed shapes of microstructures. The successful simulations open up two important applications for MEMS: CAD of mask patterns and meshing of simulated shapes for FEM simulation tools.

  6. On thermal expansion of RbD2PO4, CsH2PO4 and CsDrPO4 crystals

    International Nuclear Information System (INIS)

    Vlokh, O.G.; Shchur, Ya.I.; Klymiv, I.M.

    1994-01-01

    Thermal expansion of RbD 2 PO 4 , CsH 2 PO 4 , CsD 2 PO 4 crystals in a wide range of temperatures embracing points of phase transitions was studied. An explanation of anomalous behaviour of thermal expansion factor along directions b and c in the course of RbD 2 PO 4 transfer into intermediate phase was suggested. 10 refs., 4 figs

  7. Study of UO{sub 2}F{sub 2} - H{sub 2}O - HF compounds; Etude des composes UO{sub 2}F{sub 2} - H{sub 2}O - HF

    Energy Technology Data Exchange (ETDEWEB)

    Neveu, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    We study various compounds resulting from the interaction of UO{sub 2}F{sub 2} with H{sub 2}O and HF (gas), and various triple compounds UO{sub 2}F{sub 2} - H{sub 2}O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author) [French] Nous etudions divers composes formes par reaction de UO{sub 2}F{sub 2} avec H{sub 2}O et HF (gaz) et divers composes triples UO{sub 2}F{sub 2} - H{sub 2}O - HF, en essayant de preciser les decompositions et domaines d'exisfence thermodynamiques de ces corps. (auteur)

  8. Infrared laser spectroscopy of H2 and D2 Rydberg states. II. Diode laser spectra and assignment of 5g--4f, 6h--5g, and 8i--6h systems

    International Nuclear Information System (INIS)

    Davies, P.B.; Guest, M.A.; Stickland, R.J.

    1990-01-01

    Infrared diode laser absorption spectra of portions of the 5g--4f, 6h--5g, and 8i--6h Rydberg bands of H 2 and D 2 have been measured at Doppler limited resolution in low pressure A. C. discharges. The spectra, arising from L uncoupled states of H 2 and D 2 , are assigned using an ab initio polarization model supported by intensity calculations. Details of the different implementations of this polarization model are given in the preceding paper. The most useful was the single channel vibrationally extended (1)/(2) V 6 model which became progressively better at higher n (and L). Results of multichannel calculations for a selected set of transitions are also reported

  9. 1D ferromagnetic edge contacts to 2D graphene/h-BN heterostructures

    Science.gov (United States)

    Karpiak, Bogdan; Dankert, André; Cummings, Aron W.; Power, Stephen R.; Roche, Stephan; Dash, Saroj P.

    2018-03-01

    We report the fabrication of one-dimensional (1D) ferromagnetic edge contacts to two-dimensional (2D) graphene/h-BN heterostructures. While aiming to study spin injection/detection with 1D edge contacts, a spurious magnetoresistance signal was observed, which is found to originate from the local Hall effect in graphene due to fringe fields from ferromagnetic edge contacts and in the presence of charge current spreading in the nonlocal measurement configuration. Such behavior has been confirmed by the absence of a Hanle signal and gate-dependent magnetoresistance measurements that reveal a change in sign of the signal for the electron- and hole-doped regimes, which is in contrast to the expected behavior of the spin signal. Calculations show that the contact-induced fringe fields are typically on the order of hundreds of mT, but can be reduced below 100 mT with careful optimization of the contact geometry. There may be an additional contribution from magnetoresistance effects due to tunneling anisotropy in the contacts, which needs further investigation. These studies are useful for optimization of spin injection and detection in 2D material heterostructures through 1D edge contacts.

  10. 2-(6-Bromobenzo[d]thiazol-2-yl-5,5-dimethylthiazol-4(5H-one

    Directory of Open Access Journals (Sweden)

    Rainer Beckert

    2013-12-01

    Full Text Available The title compound, C12H9BrN2OS2, was obtained by reacting 6-bromobenzo[d]thiazole-2-carbonitrile in iso-propanol with ethyl 2-mercapto-2-methylpropanoate at reflux temperature for several hours. The resulting dimethyloxyluciferin derivative shows partial double-bond character of the carbon–carbon bond between the two heterocyclic moieties [C—C = 1.461 (3 Å]. This double bond restricts rotation around this C—C axis, therefore leading to an almost planar molecular structure [N—C—C—S torsion angle = 9.7 (3°]. The five-membered thiazoline ring is not completely planar as a result of the bulky S atom [C—S—C—C torsion angle = 5.17 (12°].

  11. + H2

    Indian Academy of Sciences (India)

    (1D. ) + H2 (v = 0, j = 0) →. OH + H is undertaken using the quasiclassical trajectory (QCT) method for the collision energy is in the large length of 1.3 to 43 kcal/mol using Dobbyn and Knowles (DK) surface, and the obtained results are compared with those available from earlier available calculated results on the BR surface ...

  12. Einstein A coefficients for rovibronic lines of the A2Π → X2Σ+ and B2Σ+ → X2Σ+ transitions of CaH and CaD

    Science.gov (United States)

    Alavi, S. Fatemeh; Shayesteh, Alireza

    2018-02-01

    Calcium monohydride is an important diatomic molecule appearing in the spectra of sunspots and M dwarfs. We report complete line lists with Einstein A coefficients for the A2Π-X2Σ+ and B2Σ+-X2Σ+ electronic transitions of CaH and CaD radicals. The most recent ab initio transition dipole moments and potential energy curves were used for the calculation of vibronic band intensities, taking the Herman-Wallis effect into account, and the rotational line strengths were calculated using the PGOPHER program of Western. For the A2Π and B2Σ+ excited states of CaH and CaD, new off-diagonal electronic matrix elements were included in the Hamiltonian matrix, and new sets of spectroscopic constants were determined in order to accurately reproduce the line positions and relative intensities of the observed branches in laboratory spectra. For both CaH and CaD isotopologues, Einstein A coefficients were calculated for all possible rovibronic transitions from the v΄ = 0-3 vibrational levels of the A2Π state and the v΄ = 0-2 vibrational levels of the B2Σ+ state to the v″ = 0-4 vibrational levels of the X2Σ+ ground state. The line lists and intensities reported here can be used to accurately determine the amounts of CaH and CaD in stellar environments.

  13. High orbital angular momentum states in H2 and D2. II. The 6h--5g and 6g--5f transitions

    International Nuclear Information System (INIS)

    Jungen, C.; Dabrowski, I.; Herzberg, G.; Kendall, D.J.W.

    1989-01-01

    A group of lines accompanying the first line of the Pfund series of the H atom has been observed by Fourier transform infrared spectrometry. The lines are due to transitions in molecular hydrogen of a nonpenetrating Rydberg electron possessing a high-orbital angular momentum, which is coupled only loosely to the vibrations and rotations of the H + 2 core. Lines belonging to the 6h--5g and 6g--5f (v=0--3) transitions of H 2 have been identified. The identifications are based on a calculation of the spectrum from first principles by multichannel quantum defect theory. The interaction between the nonpenetrating electron and the core was evaluated in terms of the permanent and induced molecular moments of H + 2 as calculated by Bishop and collaborators. The analogous transitions in D 2 have also been observed and assigned

  14. A 3d-4f complex constructed by the assembly of a cationic template, [Cu(en){sub 2}]{sup 2+}, and a 3D anionic coordination polymer, [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-}

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Szu-Yu; Yeh, Chang-Tsung; Wang, Chih-Chieh [Department of Chemistry, Soochow University, Taipei, Taiwan (China); Lee, Gene-Hsiang [Instrumentation Center, National Taiwan University, Taipei, Taiwan (China); Sheu, Hwo-Shuenn [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China)

    2017-05-18

    A three-dimensional (3D) 3d-4f complex, [Cu(en){sub 2}][Sm{sub 2}(C{sub 5}O{sub 5})(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 2}].8H{sub 2}O (1) (en = ethylenediamine, C{sub 5}O{sub 5}{sup 2-} = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), were prepared via the in-situ ring-opening oxidation reaction of croconate in the presence of the template-directed complex, [Cu(en){sub 2}]{sup 2+} cation. The structural characterization determined by X-ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-} in 1 can be describe in terms of in-plane 2D honeycomb-like [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}] layered frameworks bridged by oxalate with bis-chelating mode, being mutually interlinked via the bridge of μ{sub 1,2,3,4}-croconate ligands with bis-chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 x 11.893 Aa (longest atom-atom contact distances) along the b axis. The structure-directing complex, [Cu(en){sub 2}]{sup 2+}, and solvated water molecules are resided into these honeycomb-type hexagonal channels. The thermal stability of 1 was further studied by TGA and in-situ powder X-ray diffraction measurement. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. 2ΔH(D) and 1ΔN(D) isotope effects on nuclear shielding of ammonium ions in complexes with crown ethers and cryptands

    International Nuclear Information System (INIS)

    Hansen, P.E.; Hansen, Aa.E.; Lycka, A.; Buvari-Barcza, A.

    1993-01-01

    One-bond deuterium isotope effects on nitrogen nuclear shielding, 1 ΔN(D) and two-bond isotope effects at 1 H nuclear shielding, 2 ΔH(D), have been investigated in a series of inclusion complexes. The hosts comprise, SC-24, [2.2.2], [2.2.1], [2.2.1] D, [2.2] DD, K5, 18-crown-6 and 18-crown-6 tetracarboxylic acid. The structure of the host [2.2.1] is discussed based on isotope effects and 1 H chemical shifts, and an interesting exchange reaction is observed between CDCl 3 and ammonium ions in the [2.2.1] complex. The counterion dependence is shown to be zero for ammonium ions fully included in cages such as SC-24 and [2.2.2] and for 18-C-6(COOH) 4 . For cryptands and podands such as [2.2.1] and K5 a weak counterion dependence of 2 ΔH(D) opposite to that found for ammonium ions in water is observed, while 1 ΔN(D) and 15 N chemical shifts depend very strongly on the counterions, as also found for ammonium ions in water solution. The anilinium ion shows effects similar to those observed for the ammonium ion. 1 ΔN(D) isotope effects correlate well with δN and 2 ΔH(D) correlate with δNH. The correlation between 1 ΔN(D) and 2 ΔH(D) is different for ammonium ions in water and ions included in crowns, cryptands or podands. This shows that different mechanisms are operating. The 2 ΔH(D) isotope effects and δNH chemical shifts depend on the distance to the nearest acceptor (oxygen or nitrogen), and they also depend on the type of acceptor. 2 ΔH(D) isotope effects are found to be a good gauge of N ... N or N ... O distances of the inclusion complexes. The 2 ΔH(D) isotope effects vary with temperature, but the dramatic changes in the 1 H NMR spectra of the host are not reflected in the isotope effects. The one-bond couplings, 1 J(N,H), correlate with 2 ΔH(D). The variations are much larger for the cryptands than found in water solutions. (au) (50 refs.)

  16. Vibrational and cascade dissociation of H{sub 2}{sup +} ions by collision with gas molecules; Dissociation vibrationnelle et dissociation en cascade d'ions H{sub 2}{sup +} par collisions avec les molecules d'un gaz

    Energy Technology Data Exchange (ETDEWEB)

    Verveer, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    Protons produced by collisional dissociation of H{sub 2}{sup +} ions have an energy spectrum with a narrow central peak. For a part the protons in this peak are produced by vibrational dissociation and for another part by a cascade of two collisions. For H{sub 2}{sup +} ions of 50 to 150 keV the cross section for vibrational dissociation is about 4.1 10{sup -19} cm{sup 2}/molecule in hydrogen and 1.1 10{sup -18} cm{sup 2}/molecule in argon. (author) [French] Les protons resultant de la dissociation par collisions d'ions H{sub 2}{sup +} dans un gaz ont un spectre d'energie qui presente un pic central tres etroit. Les protons dans ce pic proviennent, pour une part de la dissociation vibrationnelle et pour l'autre part d'une suite de deux collisions. Dans le domaine d'energie des ions H{sub 2}{sup +} de 50 a 150 keV la section efficace de dissociation vibrationnel vaut 4.1 10{sup -19} cm{sup 2}/molecule pour l'hydrogene et 1,1 10{sup -18} cm{sup 2}/molecule pour l'argon.

  17. Syntheses of [5-2H]-uracil, [5-2H]-cytosine, [6-2H]-uracil and [6-2H]-cytosine

    International Nuclear Information System (INIS)

    Kiritani, Reiko; Asano, Takeyoshi; Fujita, Shin-ichi; Dohmaru, Takaaki; Kawanishi, Tetsuro

    1986-01-01

    Syntheses of [5- 2 H]-, [6- 2 H]-uracil and [5- 2 H]-, [6- 2 H]-cytosine were investigated. The catalytic reaction of uracil or cytosine with 2 H 2 gas in alkaline media gave rise to [6- 2 H]-compounds almost exclusively. On the other hand, the reaction of 5-bromouracil or 5-bromocytosine with 2 H 2 gas gave rise to a mixture of [5- 2 H]-, [6- 2 H]- and [5- 2 H, 6- 2 H]-compounds depending on the experimental conditions. By controlling the temperature, the pressure of 2 H 2 gas and the amount of catalyst, [5- 2 H]-uracil and [5- 2 H]-cytosine were obtained. The isotopic distribution in each product was measured by 1 H NMR spectroscopy combined with an HPLC method. (author)

  18. A SAS2H/KENO-V Methodology for 3D Full Core depletion analysis

    International Nuclear Information System (INIS)

    Milosevic, M.; Greenspan, E.; Vujic, J.; Petrovic, B.

    2003-04-01

    This paper describes the use of a SAS2H/KENO-V methodology for 3D full core depletion analysis and illustrates its capabilities by applying it to burnup analysis of the IRIS core benchmarks. This new SAS2H/KENO-V sequence combines a 3D Monte Carlo full core calculation of node power distribution and a 1D Wigner-Seitz equivalent cell transport method for independent depletion calculation of each of the nodes. This approach reduces by more than an order of magnitude the time required for getting comparable results using the MOCUP code system. The SAS2H/KENO-V results for the asymmetric IRIS core benchmark are in good agreement with the results of the ALPHA/PHOENIX/ANC code system. (author)

  19. Synthesis and characteristics of a novel 3-D organic amine oxalate: (enH2)1.5[Bi3(C2O4)6(CO2CONHCH2CH2NH3)].6.5H2O

    International Nuclear Information System (INIS)

    Yu Xiaohong; Zhang Hanhui; Cao Yanning; Chen Yiping; Wang Zhen

    2006-01-01

    A novel 3-D compound of (enH 2 ) 1.5 [Bi 3 (C 2 O 4 ) 6 (CO 2 CONHCH 2 CH 2 NH 3 )].6.5H 2 O has been hydrothermally synthesized and characterized by IR, ultraviolet-visible diffuse reflection integral spectrum (UV-Vis DRIS), fluorescence spectra, TGA and single crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C2/c with a=31.110(8)A, b=11.544(3)A, c=22.583(6)A, β=112.419(3) o , V=7497(3)A 3 , Z=8, R 1 =0.0463 and wR 2 =0.1393 for unique 7686 reflections I>2σ(I). In the title compound, the Bi atoms have eight-fold and nine-fold coordination with respect to the oxygen atoms, with the Bi atoms in distorted dodecahedron and monocapped square antiprism, respectively. The 3-D framework of the title compound contains channels and is composed of linkages between Bi atoms and oxalate units, forming honeycomb-like layers with two kinds of 6+6 membered aperture, and pillared by oxalate ligands and monamide groups. The channels have N-ethylamine oxalate monamide group - CO 2 CONHCH 2 CH 2 NH 3 + , which is formed by the in situ reaction of en and oxalate acid. At room temperature, the complex exhibits intense blue luminescence with an emission peak at 445nm

  20. Techniques for vector analyzing power measurements of the 2H(n vector,np)n breakup reaction at low energies

    International Nuclear Information System (INIS)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L.; Lambert, J.M.; Treado, P.A.

    1990-01-01

    Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the 2 H(d vector, n vector) 3 He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.)

  1. A SAS2H/KENO-V methodology for 3D fuel burnup analysis

    International Nuclear Information System (INIS)

    Milosevic, M.; Greenspan, E.; Vujic, J.

    2002-01-01

    An efficient methodology for 3D fuel burnup analysis of LWR reactors is described in this paper. This methodology is founded on coupling Monte Carlo method for 3D calculation of node power distribution, and transport method for depletion calculation in ID Wigner-Seitz equivalent cell for each node independently. The proposed fuel burnup modeling, based on application of SCALE-4.4a control modules SAS2H and KENO-V.a is verified for the case of 2D x-y model of IRIS 15 x 15 fuel assembly (with reflective boundary condition) by using two well benchmarked code systems. The one is MOCUP, a coupled MCNP-4C and ORIGEN2.1 utility code, and the second is KENO-V.a/ORIGEN2.1 code system recently developed by authors of this paper. The proposed SAS2H/KENO-V.a methodology was applied for 3D burnup analysis of IRIS-1000 benchmark.44 core. Detailed k sub e sub f sub f and power density evolution with burnup are reported. (author)

  2. Molecular dynamics simulation based on the multi-component molecular orbital method: Application to H5O2+,D5O2+,andT5O2+

    International Nuclear Information System (INIS)

    Ishimoto, Takayoshi; Koyama, Michihisa

    2012-01-01

    Graphical abstract: Molecular dynamics method based on multi-component molecular orbital method was applied to basic hydrogen bonding systems, H 5 O 2 + , and its isotopomers (D 5 O 2 + andT 5 O 2 + ). Highlights: ► Molecular dynamics method with nuclear quantum effect was developed. ► Multi-component molecular orbital method was used as ab initio MO calculation. ► Developed method applied to basic hydrogen bonding system, H 5 O 2 + , and isotopomers. ► O ⋯ O vibrational stretching reflected to the distribution of protonic wavefunctions. ► H/D/T isotope effect was also analyzed. - Abstract: We propose a molecular dynamics (MD) method based on the multi-component molecular orbital (MC M O) method, which takes into account the quantum effect of proton directly, for the detailed analyses of proton transfer in hydrogen bonding system. The MC M O based MD (MC M O-MD) method is applied to the basic structures, H 5 O 2 + (called “Zundel ion”), and its isotopomers (D 5 O 2 + andT 5 O 2 + ). We clearly demonstrate the geometrical difference of hydrogen bonded O ⋯ O distance induced by H/D/T isotope effect because the O ⋯ O in H-compound was longer than that in D- or T-compound. We also find the strong relation between stretching vibration of O ⋯ O and the distribution of hydrogen bonded protonic wavefunction because the protonic wavefunction tends to delocalize when the O ⋯ O distance becomes short during the dynamics. Our proposed MC M O-MD simulation is expected as a powerful tool to analyze the proton dynamics in hydrogen bonding systems.

  3. Mechanochemical Solvent-Free and Catalyst-Free One-Pot Synthesis of Pyrano[2,3-d]Pyrimidine-2,4(1H,3H-Diones with Quantitative Yields

    Directory of Open Access Journals (Sweden)

    M. Reza Naimi-Jamal

    2009-01-01

    Full Text Available Solvent-free synthesis of pyrano[2,3-d]pyrimidine-2,4(1H,3H-diones by ball-milling and without any catalyst is described. This method provides several advantages such as being environmentally friendly, using a simple workup procedure, and affording high yields.

  4. Factors affecting temporal H2S emission at construction and demolition (C&D) debris landfills.

    Science.gov (United States)

    Xu, Qiyong; Townsend, Timothy

    2014-02-01

    Odor problems associated with H2S emissions often result in odor complaints from nearby residents of C&D debris landfills, especially in the early morning. As part of a field study conducted on H2S removal ability using different cover materials, daily and seasonal H2S emissions through a soil cover layer were monitored at a C&D debris landfill to investigate factors affecting H2S emissions. H2S emission rates were not a constant, but varied seasonally, with an average emission rate of 4.67×10(-6)mgm(-2)s(-1). During a the 10-month field study, as the H2S concentration increased from 140ppm to about 3500ppm underneath the cover soil in the testing cell, H2S emissions ranged from zero to a maximum emission rate of 1.24×10(-5)mgm(-2)s(-1). Continuous emission monitoring indicated that H2S emissions even changed over time throughout the day, generally increasing from morning to afternoon, and were affected by soil moisture and temperature. Laboratory experiments were also conducted to investigate the effects of H2S concentration and cover soil moisture content on H2S emissions. The results showed that increased soil moisture reduced H2S emissions by retarding H2S migration through cover soil and dissolving H2S into soil water. The field study also indicated that due to atmospheric dispersion, high H2S emissions may not cause odor problems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Theoretical Time Dependent Thermal Neutron Spectra and Reaction Rates in H2O and D2O

    International Nuclear Information System (INIS)

    Purohit, S.N.

    1966-04-01

    The early theoretical and experimental time dependent neutron thermalization studies were limited to the study of the transient spectrum in the diffusion period. The recent experimental measurements of the time dependent thermal neutron spectra and reaction rates, for a number of moderators, have generated considerable interest in the study of the time dependent Boltzmann equation. In this paper we present detailed results for the time dependent spectra and the reaction rates for resonance detectors using several scattering models of H 2 O and D 2 O. This study has been undertaken in order to interpret the integral time dependent neutron thermalization experiments in liquid moderators which have been performed at the AB Atomenergi. The proton gas and the deuteron gas models are inadequate to explain the measured reaction rates in H 2 O and D 2 O. The bound models of Nelkin for H 2 O and of Butler for D 2 O give much better agreement with the experimental results than the gas models. Nevertheless, some disagreement between theoretical and experimental results still persists. This study also indicates that the bound model of Butler and the effective mass 3. 6 gas model of Brown and St. John give almost identical reaction rates. It is also surprising to note that the calculated reaction rate for Cd for the Butler model appears to be in better agreement with the experimental results of D 2 O than of the Nelkin model with H 2 O experiments. The present reaction rate studies are sensitive enough so as to distinguish between the gas model and the bound model of a moderator. However, to investigate the details of a scattering law (such as the effect of the hindered rotations in H 2 O and D 2 O and the weights of different dynamical modes) with the help of these studies would require further theoretical as well as experimental investigations. Theoretical results can be further improved by improving the source for thermal neutrons, the group structure and the scattering

  6. Photolysis of H2O-H2O2 Mixtures: The Destruction of H2O2

    Science.gov (United States)

    Loeffler, M. J.; Fama, M.; Baragiola, R. A.; Carlson, R. W.

    2013-01-01

    We present laboratory results on the loss of H2O2 in solid H2O + H2O2 mixtures at temperatures between 21 and 145 K initiated by UV photolysis (193 nm). Using infrared spectroscopy and microbalance gravimetry, we measured the decrease of the 3.5 micrometer infrared absorption band during UV irradiation and obtained a photodestruction cross section that varies with temperature, being lowest at 70 K. We use our results, along with our previously measured H2O2 production rates via ionizing radiation and ion energy fluxes from the spacecraft to compare H2O2 creation and destruction at icy satellites by ions from their planetary magnetosphere and from solar UV photons. We conclude that, in many cases, H2O2 is not observed on icy satellite surfaces because the H2O2 photodestruction rate is much higher than the production rate via energetic particles, effectively keeping the H2O2 infrared signature at or below the noise level.

  7. Polarized Disk Emission from Herbig Ae/Be Stars Observed Using Gemini Planet Imager: HD 144432, HD 150193, HD 163296, and HD 169142

    Energy Technology Data Exchange (ETDEWEB)

    Monnier, John D.; Aarnio, Alicia; Adams, Fred C.; Calvet, Nuria; Hartmann, Lee [Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States); Harries, Tim J.; Hinkley, Sasha; Kraus, Stefan [University of Exeter, Exeter (United Kingdom); Andrews, Sean; Wilner, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 91023 (United States); Espaillat, Catherine [Boston University, Boston, MA (United States); McClure, Melissa [European Southern Observatory, Garching (Germany); Oppenheimer, Rebecca [American Museum of Natural History, New York (United States); Perrin, Marshall [Space Telescope Science Institute, Baltimore, MD (United States)

    2017-03-20

    In order to look for signs of ongoing planet formation in young disks, we carried out the first J -band polarized emission imaging of the Herbig Ae/Be stars HD 150193, HD 163296, and HD 169142 using the Gemini Planet Imager, along with new H band observations of HD 144432. We confirm the complex “double ring” structure for the nearly face-on system HD 169142 first seen in H -band, finding the outer ring to be substantially redder than the inner one in polarized intensity. Using radiative transfer modeling, we developed a physical model that explains the full spectral energy distribution and J - and H -band surface brightness profiles, suggesting that the differential color of the two rings could come from reddened starlight traversing the inner wall and may not require differences in grain properties. In addition, we clearly detect an elongated, off-center ring in HD 163296 (MWC 275), locating the scattering surface to be 18 au above the midplane at a radial distance of 77 au, co-spatial with a ring seen at 1.3 mm by ALMA linked to the CO snow line. Lastly, we report a weak tentative detection of scattered light for HD 150193 (MWC 863) and a non-detection for HD 144432; the stellar companion known for each of these targets has likely disrupted the material in the outer disk of the primary star. For HD 163296 and HD 169142, the prominent outer rings we detect could be evidence for giant planet formation in the outer disk or a manifestation of large-scale dust growth processes possibly related to snow-line chemistry.

  8. Polarized Disk Emission from Herbig Ae/Be Stars Observed Using Gemini Planet Imager: HD 144432, HD 150193, HD 163296, and HD 169142

    International Nuclear Information System (INIS)

    Monnier, John D.; Aarnio, Alicia; Adams, Fred C.; Calvet, Nuria; Hartmann, Lee; Harries, Tim J.; Hinkley, Sasha; Kraus, Stefan; Andrews, Sean; Wilner, David; Espaillat, Catherine; McClure, Melissa; Oppenheimer, Rebecca; Perrin, Marshall

    2017-01-01

    In order to look for signs of ongoing planet formation in young disks, we carried out the first J -band polarized emission imaging of the Herbig Ae/Be stars HD 150193, HD 163296, and HD 169142 using the Gemini Planet Imager, along with new H band observations of HD 144432. We confirm the complex “double ring” structure for the nearly face-on system HD 169142 first seen in H -band, finding the outer ring to be substantially redder than the inner one in polarized intensity. Using radiative transfer modeling, we developed a physical model that explains the full spectral energy distribution and J - and H -band surface brightness profiles, suggesting that the differential color of the two rings could come from reddened starlight traversing the inner wall and may not require differences in grain properties. In addition, we clearly detect an elongated, off-center ring in HD 163296 (MWC 275), locating the scattering surface to be 18 au above the midplane at a radial distance of 77 au, co-spatial with a ring seen at 1.3 mm by ALMA linked to the CO snow line. Lastly, we report a weak tentative detection of scattered light for HD 150193 (MWC 863) and a non-detection for HD 144432; the stellar companion known for each of these targets has likely disrupted the material in the outer disk of the primary star. For HD 163296 and HD 169142, the prominent outer rings we detect could be evidence for giant planet formation in the outer disk or a manifestation of large-scale dust growth processes possibly related to snow-line chemistry.

  9. Observations of Concentration and δ D of Atmospheric H2 in an Alaskan Boreal Forest

    Science.gov (United States)

    Rahn, T.; Kitchen, N.; Fessenden, J.; Randerson, J. T.; Eiler, J. M.

    2001-12-01

    Molecular hydrogen is the second most abundant reduced gas in the atmosphere with a seasonally dependent mixing ratio averaging ~ 0.5 ppmv; the budget is thought to be controlled by sources from photo-oxidation of hydrocarbons, biomass burning and anthropogenic emissions and sinks dominated by soil uptake and oxidation by OH radicals. We are examining the isotopic signatures of these processes using a new method of H2 recovery and mass spectrometry on sub-liter-sized air samples (i.e., vigorous H2 uptake and were negatively correlated with respiring CO2 (-0.8 to -1.2 ppb H2/ppm CO2). Decreases in H2 concentration are correlated with increases in δ D, indicating that one or more steps in the process of hydrogen consumption (presumably either diffusion into the soil or microbial utilization) is isotopically fractionating. Based on these data, we derive a fractionation factor, α = D/Hresidual/D/Hconsumed = 0.96±0.01. This value is within the range of previous flux-chamber experiments [Gerst and Quay, 2001]. Data from the 24 hour time series yielded a similar nighttime draw down of H2 and elevated CO2 (observable even above canopy) and comparable fractionation factors for D/H. Unexpectedly, samples collected during daylight hours when the canopy was well flushed (evidenced by background CO2 levels) exhibited a modest positive correlation between hydrogen concentration and its deuterium content. We speculate that these enrichments may be the first observational verification of photochemically induced enrichment during oxidation of methane and non-methane hydrocarbons such as that proposed by Gerst and Quay [2001]. Gerst, S. and P. Quay, J. Geophys. Res., 106, 5021-5031, 2001.

  10. H1N1, H3N2 et B à Abidjan, Côte d'Ivoire

    African Journals Online (AJOL)

    English Title: Comparative analysis of the epidemiological and clinical profiles of influenza infection due to 2009 pH1N1, H1N1, H3N2 and B viruses in Abidjan, Cote d'Ivoire. English Abstract. Influenza can have various epidemiological and clinical characteristics. This study compares the epidemio-clinical profiles of ...

  11. Study of the solubility, viscosity and density in Na+, Zn2+/Cl− − H2O, Na+ − Zn2+ − (H2PO2)− − H2O, Na+, Cl−/(H2PO2)− − H2O, and Zn2+, Cl−/(H2PO2)− − H2O ternary systems, and in Na+, Zn2+/Cl−, (H2PO2)−//H2O reciprocal quaternary system at 273.15 K

    International Nuclear Information System (INIS)

    Adiguzel, Vedat; Erge, Hasan; Alisoglu, Vahit; Necefoglu, Hacali

    2014-01-01

    Highlights: • The physicochemical properties of ternary and one quaternary have been studied. • Reciprocal quaternary systems’ solubility and phase equilibrium have been studied. • In all systems the solid phases have been found. • It was found that Zn(H 2 PO 2 ) 2 salt contains 70% of the general crystallization field. - Abstract: The solubility and the physicochemical properties (density, viscosity) in the Na-Zn- Cl-H 2 O), (Na + Zn + H 2 PO 2 + H 2 O), (Na + Cl + H 2 PO 2 + H 2 O), and (Zn + Cl + H 2 PO 2 + H 2 O) ternaries, and in Na + , Zn 2+ /Cl − , (H 2 PO 2 ) − //H 2 O reciprocal quaternary systems at T = 273.15 K were investigated by using the isothermal method. The diagrams of ternary salts systems, (NaCl + ZnCl 2 + H 2 O), (NaCl + NaH 2 PO 2 + H 2 O), (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), are plotted in figures 1–4. However, whole ions of reciprocal quaternary salt systems are plotted in figure 5. Additionally, the density and viscosity values of ternary systems vs. their corresponding composition values in weight per cent are plotted in figures 6–10. At the (i) (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ii) (NaCl + ZnCl 2 + H 2 O), (iii) (NaCl + NaH 2 PO 2 + H 2 O), (iv) (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O) ternary systems the solid phase compositions have been determined as: (i) Zn(H 2 PO 2 ) 2H 2 O, Zn(H 2 PO 2 ) 2 , ZnCl 22H 2 O, (ii) NaCl, 2NaCl ⋅ ZnCl 22H 2 O, and ZnCl 22H 2 O, (iii) NaCl and NaH 2 PO 2H 2 O, (iv) Zn(H 2 PO 2 ) 2H 2 O and NaH 2 PO 2H 2 O, respectively. On the other hand reciprocal quaternary system was observed as: ZnCl 22H 2 O, 2NaCl ⋅ ZnCl 22H 2 O, Zn(H 2 PO 2 ) 2H 2 O, NaH 2 PO 2H 2 O, NaCl. According to results, the least soluble salt was Zn(H 2 PO 2 ) 2 . The crystallization field of this salt, being the largest in comparison with those of other salts, occupied 70% of the general crystallization field

  12. Mesospheric H2O and H2O2 densities inferred from in situ positive ion composition measurement

    Science.gov (United States)

    Kopp, E.

    1984-01-01

    A model for production and loss of oxonium ions in the high-latitude D-region is developed, based on the observed excess of 34(+) which has been interpreted as H2O2(+). The loss mechanism suggested in the study is the attachment of N2 and/or CO2 in three-body reactions. Furthermore, mesospheric water vapor and H2O2 densities are inferred from measurements of four high-latitude ion compositions, based on the oxonium model. Mixing ratios of hydrogen peroxide of up to two orders of magnitude higher than previous values were obtained. A number of reactions, reaction constants, and a block diagram of the oxonium ion chemistry in the D-region are given.

  13. On the Electronic Structure of [Cu(H2O)6]2+

    DEFF Research Database (Denmark)

    Tanaka, Kiyoshi; Johansen, Helge

    1997-01-01

    The electronic structure of the ground state and doublet excited states due to d-d transitions and charge transfer transitions from ligand to copper of [Cu(H2O)6]2+ are investigated by ab initio calculations. The excited states corresponding to the the d-d transitions are calculated to be 1.1 - 1...... on the description of these excited states. The chargetransfer excitations are predicted to start around 6.5 eV for [Cu(H2O)6]2+....

  14. Characterization of Runella slithyformis HD-Pnk, a bifunctional DNA/RNA end-healing enzyme composed of an N-terminal 2',3' -phosphoesterase HD domain and a C-terminal 5' -OH polynucleotide kinase domain.

    Science.gov (United States)

    Munir, Annum; Shuman, Stewart

    2016-11-28

    5' and 3' end healing are key steps in nucleic acid break repair in which 5' -OH ends are phosphorylated by a polynucleotide kinase and 3' -PO 4 or 2',3' -cyclic-PO 4 ends are hydrolyzed by a phosphoesterase to generate the 5' -PO 4 and 3' -OH termini required for sealing by classic polynucleotide ligases. End healing and sealing enzymes are present in diverse bacterial taxa, often organized as modular units within a single multifunctional polypeptide or as subunits of a repair complex. Here we identify and characterize Runella slithyformis HD-Pnk as a novel bifunctional end-healing enzyme composed of an N-terminal 2',3' -phosphoesterase HD domain and a C-terminal 5' -OH polynucleotide kinase P-loop domain. HD-Pnk phosphorylates 5' -OH polynucleotides (9-mers or longer) in the presence of magnesium and any NTP donor. HD-Pnk dephosphorylates RNA 2',3' -cyclic phosphate, RNA 3' -phosphate, RNA 2' -phosphate, and DNA 3' -phosphate ends in the presence of a transition metal cofactor, which can be nickel, copper or cobalt. HD-Pnkp homologs are present in genera from eleven bacterial phyla and are often encoded in an operon with a putative ATP-dependent polynucleotide ligase. The present study provides insights to the diversity of nucleic acid repair strategies via the characterization of Runella slithyformis HD-Pnkp as the exemplar of a novel clade of dual 5' and 3' end-healing enzymes that phosphorylate 5' -OH termini and dephosphorylate 2',3' -cyclic-PO 4 , 3' -PO 4 , and 2' -PO 4 ends. The distinctive feature of HD-Pnk is its domain composition: a fusion of an N-terminal HD phosphohydrolase module to a C-terminal P-loop polynucleotide kinase module. Homologs of Runella HD-Pnk with the same domain composition, domain order, and similar polypeptide size are distributed widely among genera from eleven bacterial phyla. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. “What’s in a Name?”: H.D.’s Re-Vision of Shakespeare

    Directory of Open Access Journals (Sweden)

    Claire Conilleau

    2010-09-01

    Full Text Available H.D. is both a familiar figure of the Imagist movement fashioned by Ezra Pound and an elusive author of “high modernism.” Primarily known as a poet, H.D. wrote a lot of posthumously published autobiographical prose to disentangle herself from the enshrouding influence of Imagism and the “war trauma.” Shakespeare is a powerful ally for he embodies the intersection between the personal and the literary, the real and the fictional. His plays underwrite H.D.’s autobiographical prose in relation to family, history and identity. H.D. excavates Shakespeare and his plays to reinscribe them in a new body of work – a strategy which enables her to engage with the male literary history and re-vise it by establishing a familial rather than adversarial relation to tradition. This article envisions the complex interactions between Shakespeare’s text and H.D.’s prose as the cornerstone of her positioning as woman writer in the economy of literary creation. It explores the creative diversions and reappropriations of Shakespeare’s plays that H.D. resorts to, especially her play with onomastics, the evocations and inscriptions of the Bard and his plays in the body of her works as well as a lesser known text, By Avon River, whose theme is Shakespeare himself.H.D. est à la fois une figure familière du mouvement Imagiste façonné par Ezra Pound et un auteur insaisissable du modernisme historique. Essentiellement connue comme poète, H.D. a pourtant produit de nombreux textes en prose à caractère autobiographique, qui n’ont pas été publiés de son vivant, pour s’affranchir du carcan imagiste et des traumatismes de la Guerre. Shakespeare est un allié précieux car il incarne la jonction entre le personnel et le littéraire, le réel et le fictionnel. Ses pièces sous-tendent la prose autobiographique de H.D. en rapport à la famille, l’histoire et l’identité. H.D. déterre l’auteur et ses textes pour les réinscrire dans un nouveau

  16. Comparisons of amino acids, body constituents and antioxidative response between long-time HD and normal HD.

    Science.gov (United States)

    Torigoe, Akira; Sato, Emiko; Mori, Takefumi; Ieiri, Norio; Takahashi, Chika; Ishida, Yoko; Hotta, Osamu; Ito, Sadayoshi

    2016-10-01

    Introduction Oxidative stress is one of the main mediators of progression of chronic kidney diseases (CKD). Nuclear factor E2-related factor 2 (Nrf2) is the transcription factor of antioxidant and detoxifying enzymes and related proteins which play an important role in cellular defense. Long-time hemodialysis (HD) therapy (8 hours) has been considered to be more beneficial compared to normal HD therapy (4 hours). We investigated oxidative response related to Nrf2 in peripheral blood mononuclear cells (PBMCs) of long-time HD and normal HD patients. Methods Eight adult long-time HD therapy patients (44.5 ± 3.0 years) and 10 normal HD therapy patients (68.1 ± 2.7 years) were enrolled. PBMCs were isolated and processed for expression of Nrf2 and its related genes by qRT-PCR. Plasma indoxyl sulfate, amino acids, and body constituents were measured. Findings Plasma indoxyl sulfate was significantly low after long-time HD therapy compare to that of normal HD therapy. Although, skeletal muscle mass, lean body mass, mineral and protein were significantly decreased 2 months in normal HD patients, those in long-time HD patients were significantly increased after 2 months. Almost of amino acids were significantly decreased after HD therapy in both HD therapies. Plasma amino acids were significantly low in long-time HD patients compared to normal HD patients. In PBMCs, the expression of Nrf2 was significantly decreased and hemooxygenase-1 expression was significantly increased in long-time HD compared to normal HD. Conclusion These observations indicate the beneficial effects of in long-time HD in improving oxidative stress in patients. © 2016 International Society for Hemodialysis.

  17. Construction of CARS Spectroscopy for Determination of Isotope shift of Hydrogen H2, D2

    International Nuclear Information System (INIS)

    Zidan, M. D.; Jazmati, A.; Manni, A.

    2007-01-01

    Coherent anti-Stokes Raman scattering (CARS) spectrometer has been built. It consists of Raman cell, which is filled with a H2 gas at 5 atm pressure, and a frequency-doubled Nd:YAG laser-pumped dye laser. The two beams are focused by means of a bi-convex 400 mm lens into the Raman cell. The anti-Stokes signal (CARS beam) is generated due to four-wave mixing process. The anti-Stokes signal is directed to a monochrometer entrance slit by prism to be detected by a photomultiplier, which is connected to a computer. The dye laser frequency has to be tuned to satisfy the energy difference between the V 1 beam (Nd:YAG laser beam) and the V 2 beam (the Stokes beam or the dye laser beam) that exactly corresponds to a vibrational or a rotational Raman resonance (E 2 -E 1 ) in the hydrogen molecule, then the anti-Stokes signal ( V 3 ) is generated. The spectra of the anti-Stokes signal has been recorded to determine the isotope shift between H 2 , and D 2 , which is 1161 cm -1 .

  18. The D1Πu state of HD and the mass scaling relation of its predissociation widths

    International Nuclear Information System (INIS)

    Dickenson, G D; Ubachs, W

    2012-01-01

    Absorption spectra of HD have been recorded in the wavelength range of 75–90 nm at 100 K using the vacuum ultraviolet Fourier transform spectrometer at the Synchrotron SOLEIL. The present wavelength resolution represents an order of magnitude improvement over that of previous studies. We present a detailed study of the D 1 Π u –X 1 Σ + g system observed up to v′ = 18. The Q-branch transition probing levels of Π − symmetry are observed as narrow resonances limited by the Doppler width at 100 K. Line positions for these transitions are determined to an estimated absolute accuracy of 0.06 cm −1 . Predissociation line widths of Π + levels are extracted from the absorption spectra. A comparison with the recent results on a study of the D 1 Π u state in H 2 and D 2 reveals that the predissociation widths scale as μ −2 J(J + 1), with μ being the reduced mass of the molecule and J the rotational angular momentum quantum number, as expected from an interaction with the B′ 1 Σ + u continuum causing the predissociation. (paper)

  19. Predissociation of the D 1PIsub(u) state of H2 near threshold

    International Nuclear Information System (INIS)

    Borondo, F.; Eguiagaray, L.R.; Riera, A.

    1982-01-01

    A recent calculation of Komarov and Ostrovsky (J. Phys. B.; 12:2485 (1979)) seemed to have settled a controversy regarding the different experimental values of the H(2s)/H(2p) sharing ratio in the predissociation of the D 1 PIsub(u) state of H 2 near threshold. This calculation was based on a correct physical picture of the dissociation process, but the dynamical treatment rests on invalid assumptions. In the present work, a more rigorous quantum mechanical treatment is presented, and a branching ratio of 0.70 is obtained. (author)

  20. Quantum dynamics of small H2 and D2 clusters in the large cage of structure II clathrate hydrate: Energetics, occupancy, and vibrationally averaged cluster structures

    Science.gov (United States)

    Sebastianelli, Francesco; Xu, Minzhong; Bačić, Zlatko

    2008-12-01

    We report diffusion Monte Carlo (DMC) calculations of the quantum translation-rotation (T-R) dynamics of one to five para-H2 (p-H2) and ortho-D2 (o-D2) molecules inside the large hexakaidecahedral (51264) cage of the structure II clathrate hydrate, which was taken to be rigid. These calculations provide a quantitative description of the size evolution of the ground-state properties, energetics, and the vibrationally averaged geometries, of small (p-H2)n and (o-D2)n clusters, n=1-5, in nanoconfinement. The zero-point energy (ZPE) of the T-R motions rises steeply with the cluster size, reaching 74% of the potential well depth for the caged (p-H2)4. At low temperatures, the rapid increase of the cluster ZPE as a function of n is the main factor that limits the occupancy of the large cage to at most four H2 or D2 molecules, in agreement with experiments. Our DMC results concerning the vibrationally averaged spatial distribution of four D2 molecules, their mean distance from the cage center, the D2-D2 separation, and the specific orientation and localization of the tetrahedral (D2)4 cluster relative to the framework of the large cage, agree very well with the low-temperature neutron diffraction experiments involving the large cage with the quadruple D2 occupancy.

  1. Evaluation of Lagergren Kinetics Equation by Using Novel Kinetics Expression of Sorption of Zn2+ onto Horse Dung Humic Acid (HD-HA

    Directory of Open Access Journals (Sweden)

    Bambang Rusdiarso

    2016-12-01

    Full Text Available Extraction and purification of humic acid from dry horse dung powder (HD-HA was performed successfully and the purified HD-HA was then applied as sorbent to adsorb Zn2+. Extraction and purification were performed based on procedure of Stevenson (1994 under atmospheric air. Parameters investigated in this work consist of effect of medium sorption acidity, sorption rate (ka and desorption rate constant (kd, Langmuir (monolayer and Freundlich (multilayer sorption capacities, and energy (E of sorption. The ka and kd were determined according to the kinetic model of second order sorption reaching equilibrium, monolayer sorption capacity (b and energy (E were determined according to Langmuir isotherm model, and multilayer sorption capacity (B was determined based on Freundlich isotherm model. Sorption of Zn2+ on purified HD-HA was maximum at pH 5.0. The novel kinetic expression resulted from proposed kinetic model has been shown to be more applicable than the commonly known Lagergren equation obtained from the pseudo-first order sorption model. The application of the equation revealed that the intercept of Lagergren equation, ln qe was more complex function of initial concentration of Zn2+ (a, Langmuir sorption capacity (b, and sorbed Zn2+ at equilibrium (xe.

  2. Investigation of the Na2(H2PO2)2 - Ba(H2PO2)2 - H2O Water-Salt Ternary System at Room Temperature

    OpenAIRE

    Erge, Hasan; Turan, Hakan; Kul, Ali Riza

    2016-01-01

    Objective: In this study, the solubility, density, conductivity and phase equilibria of the Na2(H2PO2)2-Ba(H2PO2)2-H2O ternary system located in the structure of the Na+, Ba2+, (H2PO2)-//H2O quaternary reciprocal water-salt system were investigated using physicochemical analysis methods. Material and Methods: Riedel-de Haen and Merck salts were used to investigate the solubility and phase equilibria of the Na2(H2PO2)2 -Ba(H2PO2)2-H2O ternary water–salt system at room temperature Res...

  3. Chemical kinetics in H{sub 2}O and D{sub 2}O under hydrothermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ghandi, K.; Alcorn, C.D.; Legate, G. [Mount Allison Univ., Sackville, New Brunswick (Canada); Percival, P.W.; Brodovitch, J.-C. [Simon Fraser Univ., Burnaby, British Columbia (Canada)

    2010-07-01

    Muonium (Mu = μ{sup +}e{sup -}) is a light analogue of the H-atom. Studies of Mu chemical kinetics have been extended to supercritical water, a medium in some designs of future generation nuclear reactors. The Supercritical-Water-Cooled Reactor (SCWR) would operate at higher temperatures than current pressurized water-cooled reactors, and the lack of knowledge of water radiolysis under supercritical conditions constitutes a technology gap for SCWR development. Accurate modeling of chemistry in a SCWR requires data on kinetics of reactions involved in the radiolysis of water. In this paper, we first review our measurements of kinetics in H{sub 2}O and then describe new data for D{sub 2}O under sub- and supercritical conditions. (author)

  4. DFT and CCSD(T) study of the A2H3- (A = Al, Ga) isomerization, [Ga2(μ-H)(μ-H2)]- and [Ga2(μ-H3)]- unprecedented hydrido-bimetallic structures

    International Nuclear Information System (INIS)

    Guermoune, Abdeladim; Jarid, Abdellah

    2007-01-01

    Total potential energy surfaces (PES) are scanned in order to study the isomerization of the A 2 H 3 - (A = Al, Ga) anions. Al 2 H 3 - PES is characterized by six minima and seven transition structures which are connectable with themselves. Indeed of these 12 same extrema, the Ga 2 H 3 - PES has three other minima and four TSs. These structures exhibit an activated H 2 molecule in one or both Ga atoms coordination sphere where the Ga atom seems imply its metallic character via its occupied d-orbital. We have also localized two unusual structures: a minimum having M 2 (μ-H)(μ-H 2 )-like structure and a transition with M 2 (μ-H 3 )-like arrangement where the H 3 entity is coordinated to both Ga atoms. The connectivity of all these extrema brings to the fore an eventual fluxional behaviour of these compounds

  5. Neutron scattering studies of K3H(SO4)2 and K3D(SO4)2: the particle-in-a-box model for the quantum phase transition.

    Science.gov (United States)

    Fillaux, François; Cousson, Alain

    2012-08-21

    In the crystal of K(3)H(SO(4))(2) or K(3)D(SO(4))(2), dimers SO(4)···H···SO(4) or SO(4)···D···SO(4) are linked by strong centrosymmetric hydrogen or deuterium bonds whose O···O length is ≈2.50 Å. We address two open questions. (i) Are H or D sites split or not? (ii) Is there any structural counterpart to the phase transition observed for K(3)D(SO(4))(2) at T(c) ≈ 85.5 K, which does not exist for K(3)H(SO(4))(2)? Neutron diffraction by single-crystals at cryogenic or room temperature reveals no structural transition and no resolvable splitting of H or D sites. However, the width of the probability densities suggest unresolved splitting of the wavefunctions suggesting rigid entities H(L1/2)-H(R1/2) or D(L1/2)-D(R1/2) whose separation lengths are l(H) ≈ 0.16 Å or l(D) ≈ 0.25 Å. The vibrational eigenstates for the center of mass of H(L1/2)-H(R1/2) revealed by inelastic neutron scattering are amenable to a square-well and we suppose the same potential holds for D(L1/2)-D(R1/2). In order to explain dielectric and calorimetric measurements of mixed crystals K(3)D((1-ρ))H(ρ)(SO(4))(2) (0 ≤ ρ ≤ 1), we replace the classical notion of order-disorder by the quantum notion of discernible (e.g., D(L1/2)-D(R1/2)) or indiscernible (e.g., H(L1/2)-H(R1/2)) components depending on the separation length of the split wavefunction. The discernible-indiscernible isostructural transition at finite temperatures is induced by a thermal pure quantum state or at 0 K by ρ.

  6. Large source test stand for H-(D-) ion source

    International Nuclear Information System (INIS)

    Larson, R.; McKenzie-Wilson, R.

    1981-01-01

    The Brookhaven National Laboratory Neutral Beam Group has constructed a large source test stand for testing of the various source modules under development. The first objective of the BNL program is to develop a source module capable of delivering 10A of H - (D - ) at 25 kV operating in the steady state mode with satisfactory gas and power efficiency. The large source test stand contains gas supply and vacuum pumping systems, source cooling systems, magnet power supplies and magnet cooling systems, two arc power supplies rated at 25 kW and 50 kW, a large battery driven power supply and an extractor electrode power supply. Figure 1 is a front view of the vacuum vessel showing the control racks with the 36'' vacuum valves and refrigerated baffles mounted behind. Figure 2 shows the rear view of the vessel with a BNL Mk V magnetron source mounted in the source aperture and also shows the cooled magnet coils. Currently two types of sources are under test: a large magnetron source and a hollow cathode discharge source

  7. Mechanics and composition of middle cerebral arteries from simulated microgravity rats with and without 1-h/d -Gx gravitation.

    Directory of Open Access Journals (Sweden)

    Jiu-Hua Cheng

    Full Text Available BACKGROUND: To elucidate further from the biomechanical aspect whether microgravity-induced cerebral vascular mal-adaptation might be a contributing factor to postflight orthostatic intolerance and the underlying mechanism accounting for the potential effectiveness of intermittent artificial gravity (IAG in preventing this adverse effect. METHODOLOGY/PRINCIPAL FINDINGS: Middle cerebral arteries (MCAs were isolated from 28-day SUS (tail-suspended, head-down tilt rats to simulate microgravity effect, S+D (SUS plus 1-h/d -Gx gravitation by normal standing to simulate IAG, and CON (control rats. Vascular myogenic reactivity and circumferential stress-strain and axial force-pressure relationships and overall stiffness were examined using pressure arteriography and calculated. Acellular matrix components were quantified by electron microscopy. The results demonstrate that myogenic reactivity is susceptible to previous pressure-induced, serial constrictions. During the first-run of pressure increments, active MCAs from SUS rats can strongly stiffen their wall and maintain the vessels at very low strains, which can be prevented by the simulated IAG countermeasure. The strains are 0.03 and 0.14 respectively for SUS and S+D, while circumferential stress being kept at 0.5 (106 dyn/cm2. During the second-run pressure steps, both the myogenic reactivity and active stiffness of the three groups declined. The distensibility of passive MCAs from S+D is significantly higher than CON and SUS, which may help to attenuate the vasodilatation impairment at low levels of pressure. Collagen and elastin percentages were increased and decreased, respectively, in MCAs from SUS and S+D as compared with CON; however, elastin was higher in S+D than SUS rats. CONCLUSIONS: Susceptibility to previous myogenic constrictions seems to be a self-limiting protective mechanism in cerebral small resistance arteries to prevent undue cerebral vasoconstriction during orthostasis at 1-G

  8. Styrylpyrylium Salts: 1H and 13C NMR High-Resolution Spectroscopy (1D and 2D

    Directory of Open Access Journals (Sweden)

    Jean Claude W. Ouédraogo

    2010-01-01

    Full Text Available 1H and 13C NMR high-resolution spectroscopy (1D and 2D (1H, 1H-COSY, HSQC, HMBC for four styrylpyrylium perchlorates were carried out and signal attributions are reported. Chemical shifts observed on 13C NMR spectra for the styrylpyrylium salts were compared with net atomic charge for carbon obtained by AM1 semiempirical calculations. The position of the styryl group present low effect on chemical shifts for carbon atoms, while the presence of methyl group led to the unshielding of the substituted carbon.

  9. Probing the global potential energy minimum of (CH2O)2: THz absorption spectrum of (CH2O)2 in solid neon and para-hydrogen

    DEFF Research Database (Denmark)

    Andersen, Jonas; Voute, A.; Mihrin, Dmytro

    2017-01-01

    conformations of Cs and C2h symmetry have almost identical energies. The present work demonstrates how the class of large-amplitude hydrogen bond vibrational motion probed in the THz region provides excellent direct spectroscopic observables for these weak intermolecular CH⋯O hydrogen bond motifs....... The combination of concentration dependency measurements, observed isotopic spectral shifts associated with H/D substitutions and dedicated annealing procedures, enables the unambiguous assignment of three large-amplitude infrared active hydrogen bond vibrational modes for the non-planar Cs configuration of (CH2O...

  10. Um estudo teórico de propriedades moleculares em complexos de hidrogênio trimoleculares C2H4···2HF, C2H2···2HF e C3h6···2HF A theoretical study of molecular properties of C2H4···2HF, C2H2···2HF AND C3H6···2HF trimolecular hydrogen-bonded complexes

    Directory of Open Access Journals (Sweden)

    Boaz G. Oliveira

    2008-01-01

    Full Text Available We present a theoretical study of molecular properties in C2H4···2HF, C2H2···2HF and C3H6···2HF trimolecular hydrogen-bonded complexes. From B3LYP/6-311++G(d,p calculations, the most important structural deformations are related to the C=C (C2H4, C≡C (C2H2, C-C (C3H6 and HF bond lengths. According to the Bader's atoms in molecules and CHELPG calculations, it was identified a tertiary interaction between the fluorine atom of the second hydrofluoric acid molecule and hydrogen atoms of the ethylene and acetylene within the C2H4···2HF and C2H2···2HF complexes, respectively. Additionally, the evaluation of the infrared spectrum characterized the new vibrational modes and bathochromic effect of the HF molecules.

  11. Comparing 1.5D ONETWO and 2D SOLPS analyses of inter-ELM H-mode plasma in DIII-D

    International Nuclear Information System (INIS)

    Owen, Larry W.; Canik, John; Groebner, R.; Callen, J.D.; Bonnin, X.; Osborne, T.H.

    2010-01-01

    A DIII-D inter-ELM H-mode plasma that is in approximate transport equilibrium is analysed with the 1.5D ONETWO core code and the 2D SOLPS code. In order to investigate the importance of core-edge coupling and 2D effects, including divertor fuelling across the X-point and poloidal asymmetries that are not explicitly included in ONETWO, the domain of SOLPS is extended to very near the magnetic axis. Two principal objectives are (1) to determine whether poloidal asymmetries in the plasma distributions are large enough to vitiate a core-type interpretive plasma transport analysis and (2) to determine whether the interpretive transport coefficients and neutral beam power and particle sources from ONETWO, when used in 2D SOLPS full plasma simulations, yield the same quality fits to the measured upstream density and temperature profiles as obtained with ONETWO. Results show that only a small increase in the separatrix value of the particle diffusion coefficient, and no change in the thermal diffusivities from ONETWO was needed to get excellent agreement of the upstream SOLPS density and temperature profiles and the Thomson scattering and CER data. Good agreement of the ONETWO and SOLPS flux surface averaged distributions of the core electron and D+ densities and temperatures are also obtained. Likewise the C6+ density, with a simple chemical sputtering model based on a constant fraction of the divertor D+ flux, the core heat and particle fluxes and the neutral density reveal no 2D effects in the core/pedestal region that would vitiate a 1.5D treatment of the inter-ELM H-mode plasma.

  12. Magnetic measurements and neutron diffraction study of the layered hybrid compounds Mn(C8H4O4)(H2O)2 and Mn2(OH)2(C8H4O4)

    International Nuclear Information System (INIS)

    Sibille, Romain; Mesbah, Adel; Mazet, Thomas; Malaman, Bernard; Capelli, Silvia; François, Michel

    2012-01-01

    Mn(C 8 H 4 O 4 )(H 2 O) 2 and Mn 2 (OH) 2 (C 8 H 4 O 4 ) layered organic–inorganic compounds based on manganese(II) and terephthalate molecules (C 8 H 4 O 4 2− ) have been studied by DC and AC magnetic measurements and powder neutron diffraction. The dihydrated compound behaves as a 3D antiferromagnet below 6.5 K. The temperature dependence of its χT product is typical of a 2D Heisenberg system and allows determining the in-plane exchange constant J≈−7.4 K through the carboxylate bridges. The magnetic structure confirms the in-plane nearest neighbor antiferromagnetic interactions and the 3D ordering. The hydroxide based compound also orders as a 3D antiferromagnet with a higher Néel temperature (38.5 K). Its magnetic structure is described from two antiferromagnetically coupled ferromagnetic sublattices, in relation with the two independent metallic sites. The isothermal magnetization data at 2 K are consistent with the antiferromagnetic ground-state of these compounds. However, in both cases, a slope change points to field-induced modification of the magnetic structure. - Graphical abstract: The macroscopic magnetic properties and magnetic structures of two metal-organic frameworks based on manganese (II) and terephthalate molecules are presented. Highlights: ► Magnetic study of Mn(C 8 H 4 O 4 )(H 2 O) 2 and Mn 2 (OH) 2 (C 8 H 4 O 4 ). ► Two compounds with common features (interlayer linker/distance, S=5/2 spin). ► Magnetic measurements quantitatively analyzed to deduce exchange constants. ► Magnetic structures determined from neutron powder diffraction experiments.

  13. Allelic association of the D2 dopamine receptor gene with receptor-binding characteristics in alcoholism

    International Nuclear Information System (INIS)

    Noble, E.P.; Blum, K.; Ritchie, T.; Montgomery, A.; Sheridan, P.J.

    1991-01-01

    The allelic association of the human D2 dopamine receptor gene with the binding characteristics of the D2 dopamine receptor was determined in 66 brains of alcoholic and non-alcoholic subjects. In a blinded experiment, DNA from the cerebral cortex was treated with the restriction endonuclease Taql and probed with a 1.5-kilobase (kb) digest of a clone (lambda hD2G1) of the human D2 dopamine receptor gene. The binding characteristics (Kd [binding affinity] and Bmax [number of binding sites]) of the D2 dopamine receptor were determined in the caudate nuclei of these brains using tritiated spiperone as the ligand. The adjusted Kd was significantly lower in alcoholic than in nonalcoholic subjects. In subjects with the A1 allele, in whom a high association with alcoholism was found, the Bmax was significantly reduced compared with the Bmax of subjects with the A2 allele. Moreover, a progressively reduced Bmax was found in subjects with A2/A2, A1/A2, and A1/A1 alleles, with subjects with A2/A2 having the highest mean values, and subjects with A1/A1, the lowest. The polymorphic pattern of the D2 dopamine receptor gene and its differential expression of receptors suggests the involvement of the dopaminergic system in conferring susceptibility to at least one subtype of severe alcoholism

  14. Upper limit for the D2H+ ortho-to-para ratio in the prestellar core 16293E (CHESS)

    Science.gov (United States)

    Vastel, C.; Caselli, P.; Ceccarelli, C.; Bacmann, A.; Lis, D. C.; Caux, E.; Codella, C.; Beckwith, J. A.; Ridley, T.

    2012-11-01

    The H_3^+ ion plays a key role in the chemistry of dense interstellar gas clouds where stars and planets are forming. The low temperatures and high extinctions of such clouds make direct observations of H_3^+ impossible, but lead to large abundances of H2D+ and D2H+, which are very useful probes of the early stages of star and planet formation. The ground-state rotational ortho-D2H+ 11,1-00,0 transition at 1476.6 GHz in the prestellar core 16293E has been searched for with the Herschel HIFI instrument, within the CHESS (Chemical HErschel Surveys of Star forming regions) Key Program. The line has not been detected at the 21 mK km s-1 level (3σ integrated line intensity). We used the ortho-H2D+ 11,0-11,1 transition and para-D2H+ 11,0-10,1 transition detected in this source to determine an upper limit on the ortho-to-para D2H+ ratio as well as the para-D2H+/ortho-H2D+ ratio from a non-local thermodynamic equilibrium analysis. The comparison between our chemical modeling and the observations suggests that the CO depletion must be high (larger than 100), with a density between 5 × 105 and 106 cm-3. Also the upper limit on the ortho-D2H+ line is consistent with a low gas temperature (~11 K) with a ortho-to-para ratio of 6 to 9, i.e. 2 to 3 times higher than the value estimated from the chemical modeling, making it impossible to detect this high frequency transition with the present state of the art receivers. The chemical network is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A33Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  15. Continuous infra-red measurement using an interference filter, dosage of H{sub 2}O - D{sub 2}O mixtures; Doseur continu infra-rouge a filtre interferentiel dosage des melanges H{sub 2}O - D{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Ceccaldi, M; Goujon, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In this report is described original work leading to the construction of an apparatus for the continuous measurement of the isotopic content of H{sub 2}O - D{sub 2}O mixtures. The measurement is based on an application of the Beer-Lambert law to the {gamma}{sub OH} band of HDO (3400 cm{sup -1}). The conditions of measurement are given. The apparatus is a double-beam device in which the wave length selection is obtained with an interference filter together with a modulator acting as a pass-band filter. The large-surface pneumatic detector using capacity changes has made it possible to obtain a simple optical set-up. Various results are presented. If sufficient precautions are taken to maintain the apparatus and the water at a constant temperature it is possible to carry out measurements with a precision of {+-} 0.002, or else to detect concentration differences of 0.001 per cent in the case of heavy waters containing more than 99.5 per cent of D{sub 2}O. (authors) [French] Dans ce memoire original il est decrit la realisation d'un appareil destine a mesurer en continu la teneur isotopique des melanges H{sub 2}O-D{sub 2}O. La mesure est basee sur l'application de la loi de Beer-Lambert a la bande {gamma}{sub OH} de HDO (3400 cm{sup -1}). Les conditions de mesure sont precisees. L'appareil est un dispositif 'double-faisceau' dans lequel la selection des longueurs d'onde est obtenue par un filtre interferentiel associe a un modulateur travaillant en filtre passe-bande. Le detecteur pneumatique, de grande surface, a variation de capacite, a permis un montage optique simple. Divers resultats sont presentes. En prenant la precaution de maintenir constante la temperature de l'appareil et de l'eau on peut effectuer des mesures a {+-} 0,002 pour cent pres, ou mettre en evidence des ecarts de teneur de 0,001 pour cent pour des eaux lourdes de titre superieur a 99,5 pour cent. (auteurs)

  16. Isotopic labeling affects 1,25-dihydroxyvitamin D metabolism

    International Nuclear Information System (INIS)

    Halloran, B.P.; Bikle, D.D.; Castro, M.E.; Gee, E.

    1989-01-01

    Isotope substitution can change the biochemical properties of vitamin D. To determine the effect of substituting 3H for 1H on the metabolism of 1,25(OH)2D3, we measured the metabolic clearance rate and renal metabolism of unlabeled and 3H-labeled 1,25(OH)2D3. Substitution of 3H for 1H on carbons 26 and 27 [1,25(OH)2[26,27(n)-3H]D3] or on carbons 23 and 24 [1,25(OH)2[23,24(n)-3H]D3] reduced the in vivo metabolic clearance rate of 1,25(OH)2D3 by 36% and 37%, respectively, and reduced the in vitro renal catabolism of 1,25(OH)2D3 by 11% and 54%, respectively. Substitutions of 3H for 1H on carbons 23 and 24 as opposed to carbons 26 and 27 reduced conversion of [3H]1,25(OH)2D3 to [3H]1,24,25(OH)2D3 by 25% and to putative 24-oxo-1,23,25-dihydroxyvitamin D3 by 1600%. These results indicate that substitution of 3H for 1H on carbons 26 and 27 or on carbons 23 and 24 can reduce the metabolic clearance rate and in vitro metabolism of 1,25(OH)2D3 and quantitatively alter the pattern of metabolic products produced

  17. Techniques for vector analyzing power measurements of the sup 2 H(n vector,np)n breakup reaction at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L. (Duke Univ., Durham, NC (USA) Triangle Universities Nuclear Lab., Durham, NC (USA)); Lambert, J.M.; Treado, P.A. (Georgetown Univ., Washington, DC (USA). Dept. of Physics); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia))

    1990-05-10

    Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the {sup 2}H(d vector, n vector){sup 3}He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.).

  18. HFE Mutations C282Y and H63D in Iranian Population With Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Golchin

    2015-04-01

    Full Text Available Background Type 2 diabetes (T2D is a common metabolic disease caused by insulin secretion defects, which is associated with a variety of complications such as retinopathy, nephropathy, and neuropathy. Objectives Regarding the relationship between type 2 diabetes and hereditary chromatists, we conducted a genetic analysis on two previously reported mutations C282Y and H63D related to the HFE gene in our population. Patients and Methods Altogether, 145 patients with type 2 diabetes and 145 healthy controls were examined. A genotyping assay performed using electrophoresis of the DNA digestion products from MboI and RsaI for H63D and C282Y, respectively. Results Results showed a significant difference between case and controls regarding C282Y (P value < 0.001 and H63D genotypes (P value = 0.013. We also found a relationship between both mutations and nephropathy. Moreover, the difference between C282Y genotypes of patients with retinopathy and healthy controls were statistically significant (P value = 0.020 while there was no association between H63D and retinopathy. In addition, observed differences of both mutations were significant when nephropathic patients compared to the controls. Conclusions Our study showed a significant association between H63D and C282Y mutations and the risk of type 2 diabetes in Iranian population.

  19. Filtering reaction dynamics using nearside-farside theory and local angular momentum theory: application to the angular scattering of the H + D2(v(i) = 0, j(i) = 0) --> HD(v(f) = 3, j(f) = 0) + D reaction in the energy and time domains.

    Science.gov (United States)

    Monks, P D D; Connor, J N L; Bouakline, F

    2009-04-23

    We investigate methods for filtering reaction mechanisms in the angular scattering of the state-to-state reaction, H + D(2)(v(i) = 0, j(i) = 0, m(i) = 0) --> HD(v(f) = 3, j(f) = 0, m(f) = 0) + D, where v(i), j(i), and m(i) and v(f), j(f), and m(f) are initial and final vibrational, rotational, and helicity quantum numbers, respectively. The input to our filtrations is a new set of accurate quantum scattering matrix elements for total energies in the range 1.52-2.50 eV (in steps of 0.01 eV) and for total angular momentum quantum numbers in the range, 0-40, in steps of unity. We filter reaction mechanisms in both the energy domain and the time domain. The time-domain calculations employ the plane wave packet formulation of time-dependent scattering. The theoretical tools used are nearside-farside (NF) analysis of partial wave series for scattering amplitudes, together with NF local angular momentum (LAM) theory. An energy-domain LAM analysis reveals the existence of an important dynamical feature in the N scattering, a "trench" which bisects the (energy, angle) plane. We use the location of this trench to approximately filter two reaction mechanisms. Transformation to the time domain demonstrates that the two reaction mechanisms correspond to direct and delayed (by about 25 fs) scattering. Further analysis, including filtration in the time domain, shows that the pronounced LAM trench arises from the interference of the energy-domain analogues of the time-direct and time-delayed scattering. Our theory and results provide the first successful demonstration of reaction mechanism filtering carried out directly in the (energy, angle) domain. The calculations and results in this paper extend and complement earlier research reported by Monks, Connor, and Althorpe (Monks, P. D. D.; Connor, J. N. L.; Althorpe, S. C. J. Phys. Chem. A 2006, 110, 741; J. Phys. Chem. A 2007, 111, 10302).

  20. Listeria monocytogenes infection of HD11, chicken macrophage-like cells.

    Science.gov (United States)

    Jarvis, N A; Donaldson, J R; O'Bryan, C A; Ricke, S C; Crandall, P G

    2017-04-01

    Listeria monocytogenes can be carried by and infect poultry, although the clinical disease in birds is rare. Escape from macrophage phagocytosis is a key step in pathogenesis for L. monocytogenes. Therefore, we investigated the infection of the chicken macrophage-like cell line HD11 with 2 strains of L. monocytogenes EGD-e and Scott A. After infection, L. monocytogenes was quantified by spread plating and HD11 was quantified with trypan blue exclusion stain before enumeration. The standard macrophage killing protocols require washing the cell monolayers 3 times with PBS, which was found to negatively influence HD11 monolayers. Maximum bacterial densities within macrophages were not different between the 2 Listeria strains. HD11 required more than 11 h to effectively reduce intracellular L. monocytogenes Scott A, and Scott A was more susceptible to HD11 killing than EGD-e. It appears that Listeria infection initially causes attenuation of HD11 growth, and infected HD11 cells do not begin to lyse until at least 11 h post infection. These results suggest that there are subtle strain to strain differences in response to HD11 macrophage phagocytosis. The long lead-time required for HD11 to kill L. monocytogenes cells means that there is sufficient time available for chicken macrophages to circulate in the blood and transfer the intracellular Listeria to multiple tissues. © 2016 Poultry Science Association Inc.

  1. Sub-Doppler slit jet infrared spectroscopy of astrochemically relevant cations: Symmetric (ν1) and antisymmetric (ν6) NH stretching modes in ND2H2+

    Science.gov (United States)

    Chang, Chih-Hsuan; Nesbitt, David J.

    2018-01-01

    Sub-Doppler infrared rovibrational transitions in the symmetric (v1) and antisymmetric (v6) NH stretch modes of the isotopomerically substituted ND2H2+ ammonium cation are reported for the first time in a slit jet discharge supersonic expansion spectrometer. The partially H/D substituted cation is generated by selective isotopic exchange of ND3 with H2O to form NHD2, followed by protonation with H3+ formed in the NHD2/H2/Ne slit-jet discharge expansion environment. Rotational assignment for ND2H2+ is confirmed rigorously by four line ground state combination differences, which agree to be within the sub-Doppler precision in the slit jet (˜9 MHz). Observation of both b-type (ν1) and c-type (ν6) bands enables high precision determination of the ground and vibrationally excited state rotational constants. From an asymmetric top Watson Hamiltonian analysis, the ground state constants are found to be A″ = 4.856 75(4) cm-1, B″ = 3.968 29(4) cm-1, and C″ = 3.446 67(6) cm-1, with band origins at 3297.5440(1) and 3337.9050(1) cm-1 for the v1 and v6 modes, respectively. This work permits prediction of precision microwave/mm-wave transitions, which should be invaluable in facilitating ongoing spectroscopic searches for partially deuterated ammonium cations in interstellar clouds and star-forming regions of the interstellar medium.

  2. Syntheses of 24R,25-dihydroxy-[6,19,19-3H]vitamin D3 and 24R,25-dihydroxy-[6,19,19-2H]vitamin D3

    International Nuclear Information System (INIS)

    Yamada, S.; Shimizu, M.; Fukushima, K.; Niimura, K.; Maeda, Y.

    1989-01-01

    24R,25-Dihydroxy-[6,19,19-3H]vitamin D3 with a specific activity of 54 Ci/mmol and 24R,25-dihydroxy-[6,19,19-2H]vitamin D3 with 2.6 deuterium atoms/mol were synthesized in four steps starting from 24R,25-Dihydroxyvitamin D3 via its sulfur dioxide adduct

  3. Crankshafts: using simple, flat C2h-symmetric molecules to direct the assembly of chiral 2D nanopatterns.

    Science.gov (United States)

    Zhou, Hui; Wuest, James D

    2013-06-18

    Linear D2h-symmetric bisisophthalic acids 1 and 2 and related substances have well-defined flattened structures, high affinities for graphite, and strong abilities to engage in specific intermolecular interactions. Their adsorption produces characteristic nanopatterns that reveal how 2D molecular organization can be controlled by reliable interadsorbate interactions such as hydrogen bonds when properly oriented by molecular geometry. In addition, the behavior of these compounds shows how large-scale organization can be obstructed by programming molecules to associate strongly according to competing motifs that have similar stability and can coexist smoothly without creating significant defects. Analogous new bisisophthalic acids 3a and 4a have similar associative properties, and their unique C2h-symmetric crankshaft geometry gives them the added ability to probe the poorly understood effect of chirality on molecular organization. Their adsorption shows how nanopatterns composed predictably of a single enantiomer can be obtained by depositing molecules that can respect established rules of association only by accepting neighbors of the same configuration. In addition, an analysis of the adsorption of crankshaft compounds 3a and 4a and their derivatives by STM reveals directly on the molecular level how kinetics and thermodynamics compete to control the crystallization of chiral compounds. In such ways, detailed studies of the adsorption of properly designed compounds on surfaces are proving to be a powerful way to discover and test rules that broadly govern molecular organization in both 2D and 3D.

  4. Trojan Horse particle invariance for 2H(d,p)3H reaction: a detailed study

    International Nuclear Information System (INIS)

    Pizzone, R.G.; La Cognata, M.; Rinollo, A.; Spitaleri, C; Sparta, R.; Bertulani, C.A.; Mukhamedzhanov, A.M.; Blokhintsev, L.; Lamia, L.; Tumino, A.

    2014-01-01

    The basic idea of the Trojan Horse Method (THM) is to extract the cross section in the low-energy region of a two-body reaction with significant astrophysical impact: a + x → c + C from a suitable quasi-free (QF) break-up of the so called Trojan Horse nucleus, e.g. A=x (+) s where usually x is referred to as the participant and s as the spectator particle. In the last decades the Trojan Horse method has played a crucial role for the measurement of several charged particle induced reactions cross sections of astrophysical interest. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The Trojan Horse nucleus invariance for the binary d(d,p)t reaction was therefore tested using the quasi free 2 H( 6 Li, pt) 4 He and 2 H( 3 He,pt)H reactions after 6 Li and 3 He break-up, respectively. The astrophysical S(E)-factor for the d(d,p)t binary process was then extracted in the framework of the Plane Wave Approximation applied to the two different break-up schemes. Polynomial fits were then performed on the data giving S 0 = (75 ± 21) keV*b in the case of the 6 Li break-up, while for 3 He one obtains S 0 = (58 ± 2) keV*b. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement confirms the applicability of the plane wave approximation and suggests the independence of binary indirect cross section on the chosen Trojan Horse nucleus also for the present case

  5. Analysis of 2H(rvec d,p)3H reaction by the four-body Faddeev-Yakubovsky equations

    International Nuclear Information System (INIS)

    Uzu, E.; Oryu, S.; Tanifuji, M.

    1995-01-01

    Very low energy 2 H(rvec d,p) 3 H reactions are investigated by using the four-body Fadeev-Yakubovsky integral equations. The adopted potential is the Ernst-Shakin-Thaler's separable expansion of the Paris potential or the PEST potential. The [3+1] and the [2+2] sub-amplitudes are given by the Hilbert-Schmidt rank-2, rank-3 and rank-4 separable expansion. The calculated total cross section, differential cross section, and tensor analyzing powers at 30keV-90keV are in very good agreement with the experimental data. copyright 1995 American Institute of Physics

  6. The denitrification paradox: The role of O2 in sediment N2O production

    Science.gov (United States)

    Barnes, Jonathan; Upstill-Goddard, Robert C.

    2018-01-01

    We designed a novel laboratory sediment flux chamber in which we maintained the headspace O2 partial pressure at preselected values, allowing us to experimentally regulate "in-situ" O2 to evaluate its role in net N2O production by an intertidal estuarine sediment (Tyne, UK). In short-term (30 h) incubations with 10 L of overlying estuarine water (∼3 cm depth) and headspace O2 regulation (headspace: sediment/water ratio ∼9:1), net N2O production was highest at 1.2% O2 (sub-oxic; 32.3 nmol N2O m-2 d-1), an order of magnitude higher than at either 0.0% (anoxic; 2.5 N2O nmol m-2 d-1) or 20.85% (ambient; 2.3 nmol N2O m-2 d-1) O2. In a longer-term sealed incubation (∼490 h) without O2 control, time-dependent behaviour of N2O in the tank headspace was highly non-linear with time, showing distinct phases: (i) an initial period of no or little change in O2 or N2O up to ∼ 100 h; (ii) a quasi-linear, inverse correlation between O2 and N2O to ∼360 h, in which O2 declined to ∼2.1% and N2O rose to ∼7800 natm; (iii) over the following 50 h a slower O2 decline, to ∼1.1%, and a more rapid N2O increase, to ∼12000 natm; (iv) over the next 24 h a slowed O2 decline towards undetectable levels and a sharp fall in N2O to ∼4600 natm; (iv) a continued N2O decrease at zero O2, to ∼3000 natm by ∼ 490 h. These results show clearly that rapid N2O consumption (∼115 nmol m-2 d-1), presumably via heterotrophic denitrification (HD), occurs under fully anoxic conditions and therefore that N2O production, which was optimal for sub-oxic O2, results from other nitrogen transformation processes. In experiments in which we amended sediment overlying water to either 1 mM NH4+ or 1 mM NO3-, N2O production rates were 2-134 nmol N2O m-2 d-1 (NH4+ addition) and 0.4-2.2 nmol N2O m-2 d-1 (NO3- addition). We conclude that processes involving NH4+ oxidation (nitrifier nitrification; nitrifier denitrification; nitrification-coupled denitrification) are principally responsible for N2O

  7. Analyzing powers for the three-nucleon breakup reaction 1H(d vector,p)pn at 16 MeV

    International Nuclear Information System (INIS)

    Brown, R.E.; Ohlsen, G.G.; Correll, F.D.; Hardekopf, R.A.; Jarmie, N.

    1980-01-01

    Analyzing powers for the 1 H(d,p)pn reaction were measured at 16.0 MeV and beam polarization of approximately 0.82. Similar data for the elastic scattering 1 H(d,p) 2 H were also taken. The breakup analyzing power A/sub xz/, which attains the largest magnitude, is shown as a function of excitation energy. Angular distributions of elastic and breakup analyzing powers are compared; large differences are noted for A/sub xx/ and A/sub xz/. It is found that 1-MeV energy bins are too large to use in the study of singlet-state effects. 2 figures

  8. Coordination polymers of scandium sulfate. Crystal structures of (H2Bipy)[Sc(H2O)(SO4)2]2·2H2O and (H2Bipy)[HSO4]2

    International Nuclear Information System (INIS)

    Petrosyants, S.P.; Ilyukhin, A.B.

    2005-01-01

    Compounds with general formula Cat x [Sc(H 2 O) z (SO 4 ) y ]·nH 2 O (Cat=NH 4 , H 2 Bipy (Bipy - 4,4'-bipyridine), HEdp (Edp - ethylene dipyridine)) identified on element analysis data and IR spectra are synthesized. X-ray diffraction analysis of (H 2 Bipy)[Sc(H 2 O)(SO 4 ) 2 ] 2 ·2H 2 O shows that in structure of the compound chains of ScO 6 octahedron and SO 4 tetrahedrons are joined in bands by tridentate coordination of sulfate ions. Bands form skeleton in endless emptiness of which there are H 2 Bipy 2+ cations [ru

  9. Supercritical fluid in the mantle transition zone deduced from H-D interdiffusion of wadsleyite

    Science.gov (United States)

    Sun, Wei; Yoshino, Takashi; Sakamoto, Naoya; Yurimoto, Hisayoshi

    2018-02-01

    Knowledge of the distribution of water in the Earth's mantle is key to understanding the mantle convection and geochemical evolution of the Earth. As wadsleyite and ringwoodite can incorporate large amounts of water in their crystal structures, proton conduction has been invoked to account for the widespread conductive anomalies observed in the mantle wedge, where descending slab stagnates at the transition zone. However, there is a lot of controversy on whether proton conduction by itself is able to explain such anomalies, because of large discrepancy in the extent of the water effect deduced from previous electrical conductivity measurements on hydrous polycrystalline wadsleyite and ringwoodite. Here we report the hydrogen self-diffusion coefficient obtained from H-D interdiffusion experiments in wadsleyite single-crystal couples. Our results demonstrate that the effect of water on the electrical conductivity of wadsleyite is limited and hydrous wadsleyite by itself is unable to explain conductive anomalies in the transition zone. In contrast, the expected hydrogen effective diffusion does not allow the wide propagation of water between the stagnant slab and surrounding mantle, probably leading to persistence of local water saturation and continuous release of supercritical fluids at the stagnant slab roof on geological time scales. This phenomenon provides an alternative explanation for both the high-conductivity and seismic-velocity anomalies observed in the mantle wedge at the transition-zone depth.

  10. 2-(1H-Imidazol-1-yl)-3-isopropyl-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

    OpenAIRE

    Xu, Sheng-Zhen

    2007-01-01

    In the title compound, C16H14N4OS, the three fused rings of the benzothieno[3,2-d]pyrimidinone unit are essentially coplanar, the maximum deviation from the mean plane being 0.067 (3) Å. The dihedral angle between the mean plane of the fused rings and the imidazole ring is 72.00 (3)°. Offset π–π stacking interactions involving the fused rings are effective in the stabilization of the crystal structure. The centroid–centroid distances between t...

  11. Deuterium and 15N fractionation in N2H+ during the formation of a Sun-like star

    Science.gov (United States)

    De Simone, M.; Fontani, F.; Codella, C.; Ceccarelli, C.; Lefloch, B.; Bachiller, R.; López-Sepulcre, A.; Caux, E.; Vastel, C.; Soldateschi, J.

    2018-05-01

    Although chemical models predict that the deuterium fractionation in N2H+ is a good evolutionary tracer in the star formation process, the fractionation of nitrogen is still a poorly understood process. Recent models have questioned the similar evolutionary trend expected for the two fractionation mechanisms in N2H+, based on a classical scenario in which ion-neutral reactions occurring in cold gas should have caused an enhancement of the abundance of N2D+, 15NNH+, and N15NH+. In the framework of the ASAI IRAM-30m large program, we have investigated the fractionation of deuterium and 15N in N2H+ in the best known representatives of the different evolutionary stages of the Sun-like star formation process. The goal is to ultimately confirm (or deny) the classical `ion-neutral reactions' scenario that predicts a similar trend for D and 15N fractionation. We do not find any evolutionary trend of the 14N/15N ratio from both the 15NNH+ and N15NH+ isotopologues. Therefore, our findings confirm that, during the formation of a Sun-like star, the core evolution is irrelevant in the fractionation of 15N. The independence of the 14N/15N ratio with time, found also in high-mass star-forming cores, indicates that the enrichment in 15N revealed in comets and protoplanetary discs is unlikely to happen at core scales. Nevertheless, we have firmly confirmed the evolutionary trend expected for the H/D ratio, with the N2H+/N2D+ ratio decreasing before the pre-stellar core phase, and increasing monotonically during the protostellar phase. We have also confirmed clearly that the two fractionation mechanisms are not related.

  12. A new ab initio potential energy surface for the collisional excitation of N2H+ by H2

    International Nuclear Information System (INIS)

    Spielfiedel, Annie; Balança, Christian; Feautrier, Nicole; Senent, Maria Luisa; Kalugina, Yulia; Scribano, Yohann; Lique, François

    2015-01-01

    We compute a new potential energy surface (PES) for the study of the inelastic collisions between N 2 H + and H 2 molecules. A preliminary study of the reactivity of N 2 H + with H 2 shows that neglecting reactive channels in collisional excitation studies is certainly valid at low temperatures. The four dimensional (4D) N 2 H + –H 2 PES is obtained from electronic structure calculations using the coupled cluster with single, double, and perturbative triple excitation level of theory. The atoms are described by the augmented correlation consistent triple zeta basis set. Both molecules were treated as rigid rotors. The potential energy surface exhibits a well depth of ≃2530 cm −1 . Considering this very deep well, it appears that converged scattering calculations that take into account the rotational structure of both N 2 H + and H 2 should be very difficult to carry out. To overcome this difficulty, the “adiabatic-hindered-rotor” treatment, which allows para-H 2 (j = 0) to be treated as if it were spherical, was used in order to reduce the scattering calculations to a 2D problem. The validity of this approach is checked and we find that cross sections and rate coefficients computed from the adiabatic reduced surface are in very good agreement with the full 4D calculations

  13. A new ab initio potential energy surface for the collisional excitation of N2H(+) by H2.

    Science.gov (United States)

    Spielfiedel, Annie; Senent, Maria Luisa; Kalugina, Yulia; Scribano, Yohann; Balança, Christian; Lique, François; Feautrier, Nicole

    2015-07-14

    We compute a new potential energy surface (PES) for the study of the inelastic collisions between N2H(+) and H2 molecules. A preliminary study of the reactivity of N2H(+) with H2 shows that neglecting reactive channels in collisional excitation studies is certainly valid at low temperatures. The four dimensional (4D) N2H(+)-H2 PES is obtained from electronic structure calculations using the coupled cluster with single, double, and perturbative triple excitation level of theory. The atoms are described by the augmented correlation consistent triple zeta basis set. Both molecules were treated as rigid rotors. The potential energy surface exhibits a well depth of ≃2530 cm(-1). Considering this very deep well, it appears that converged scattering calculations that take into account the rotational structure of both N2H(+) and H2 should be very difficult to carry out. To overcome this difficulty, the "adiabatic-hindered-rotor" treatment, which allows para-H2(j = 0) to be treated as if it were spherical, was used in order to reduce the scattering calculations to a 2D problem. The validity of this approach is checked and we find that cross sections and rate coefficients computed from the adiabatic reduced surface are in very good agreement with the full 4D calculations.

  14. HD 97658 and its super-Earth

    Directory of Open Access Journals (Sweden)

    Van Grootel V.

    2015-01-01

    Full Text Available Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present the confirmation, based on Spitzer observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a low-mass (M* = 0.77 ± 0.05 M⊙ K1 dwarf, as determined from the Hipparcos parallax and stellar evolution modeling. To constrain the planet parameters, we carry out Bayesian global analyses of Keck-HIRES radial velocities, and MOST and Spitzer photometry. HD 97658 b is a massive (MP = 7.55−0.79+0.83 M⊕ and large (RP = 2.247−0.095+0.098 R⊕ at 4.5 μm super-Earth. We investigate the possible internal compositions for HD 97658 b. Our results indicate a large rocky component, by at least 60% by mass, and very little H-He components, at most 2% by mass. We also discuss how future asteroseismic observations can improve the knowledge of the HD 97658 system, in particular by constraining its age.

  15. Ground and excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters: Insight into the electronic structure of the [Fe(H2O)6]2+ – [Fe(H2O)6]3+ complex

    Energy Technology Data Exchange (ETDEWEB)

    Miliordos, Evangelos; Xantheas, Sotiris S.

    2015-04-14

    We report the ground and low lying electronically excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters using multi-configuration electronic structure theory. In particular, we have constructed the Potential Energy Curves (PECs) with respect to the iron-oxygen distance when removing all water ligands at the same time from the cluster minima and established their correlation to the long range dissociation channels. Due to the fact that both the second and third ionization potentials of iron are larger than the one for water, the ground state products asymptotically correlate with dissociation channels that are repulsive in nature at large separations as they contain at least one H2O+ fragment and a positive metal center. The most stable equilibrium structures emanate – via intersections and/or avoided crossings – from the channels consisting of the lowest electronic states of Fe2+(5D; 3d6) or Fe3+(6S; 3d5) and six neutral water molecules. Upon hydration, the ground state of Fe2+(H2O)6 is a triply (5Tg) degenerate one with the doubly (5Eg) degenerate state lying slightly higher in energy. Similarly, Fe3+(H2O)6 has a ground state of 6Ag symmetry under Th symmetry. We furthermore examine a multitude of electronically excited states of many possible spin multiplicities, and report the optimized geometries for several selected states. The PECs for those cases are characterized by a high density of states. Focusing on the ground and the first few excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters, we studied their mutual interaction in the gas phase. We obtained the optimal geometries of the Fe2+(H2O)6 – Fe3+(H2O)6 gas phase complex for different Fe–Fe distances. For distances shorter than 6.0 Å, the water molecules in the respective first solvation shells located between the two metal centers were found to interact via weak hydrogen bonds. We examined a total of ten electronic states for this complex, including those corresponding to the

  16. Isotope effects in aqueous systems. Excess thermodynamic properties of 1,3-dimethylurea solutions in H2O and D2O

    International Nuclear Information System (INIS)

    Jakli, G.; Hook, W.A. Van

    1997-01-01

    The osmotic coefficients of 1,3-dimethylurea-h 2 (DMUh 2 )/H 2 O and 1,3-dimethylurea-d 2 (DMUd 2 )/D 2 O solutions (1, 2, 4, 12, and 20 m aq , 15 < t/degree C < 80) were obtained from differential vapor pressure measurements. Excess partial molar free energies, enthalpies, and entropies for the solvent and their isotope effects were calculated from the temperature derivatives of the osmotic coefficients. New partial molar volume data are reported at 25 C at low and intermediate concentrations. The thermodynamic properties of solution are compared with those of urea and discussed using the cage model of hydrophobic hydration. The results support the mixed (polar-apolar) character of this compound and show that its structural effect on water changes with temperature and concentration

  17. Facial One-Pot Synthesis of D 3h Symmetric Bicyclocalix[2]arene[2]triazines and Their Layered Comb Self-Assembly

    KAUST Repository

    Chen, Yin; Jiahui, Wang; Xu, Hai; Qianqian, Li; Jing, Jiang

    2017-01-01

    A number of D3h symmetric bicyclocalix[2]arene[2]triazine core compounds were synthesized via a general and good-yielding (43-48% yield) facile protocol starting from cyanuric halides, phloroglucinol and K2CO3 under very mild reaction conditions

  18. Self-assembly of red-blood-cell-like (NH4)[Fe2(OH)(PO4)22H2O architectures from 2D nanoplates by sonochemical method.

    Science.gov (United States)

    Wu, Kaipeng; Liu, Diwei; Tang, Yun

    2018-01-01

    Red-blood-cell-like (RBC-like) (NH 4 )[Fe 2 (OH)(PO 4 ) 22H 2 O architectures assembled from 2D nanoplates are successfully synthesized via a facile sonochemical method. XRD measurement indicates that the as-prepared sample is well crystallized with a monoclinic structure. The morphology of the sample is characterized by SEM analysis, which shows that the (NH 4 )[Fe 2 (OH)(PO 4 ) 22H 2 O particles exhibit a unique biconcave red blood cell morphology with an average diameter of 4um and thickness of 1.5um. The detailed time-dependent experiments are conducted to investigate the morphological evolution process. It reveals that the ultrasonic time is crucial to the morphology of the products, and the RBC-like (NH 4 )[Fe 2 (OH)(PO 4 ) 22H 2 O proceeds in steps of crystallization, formation of thin plates, and the subsequent self-assembly. Compared to the available methods that are typically time-consuming and complicated, this smart sonochemical strategy proposed herein is efficient and simple. Moreover, these obtained special RBC-like architectures will be more fascinating for application in many areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) mediates repression of TNF-α by decreasing levels of acetylated histone H3 and H4 at its promoter

    International Nuclear Information System (INIS)

    Engdahl, Ryan; Monroy, M. Alexandra; Daly, John M.

    2007-01-01

    Prostaglandin metabolite 15-Deoxy-Δ 12,14 -prostaglandin J2 (15d-PGJ2) is known to inhibit a number of pro-inflammatory cytokines as well as being a ligand for nuclear receptor PPARγ. We investigated the ability of 15d-PGJ2 to inhibit TNF-α gene expression through mechanisms that involve histone modification. Pretreatment with 15d-PGJ2 (10 μM) inhibited LPS-stimulated TNF-α mRNA in THP-1 monocytes or PMA-differentiated cells to nearly basal levels. A specific PPARγ ligand, GW1929, failed to inhibit LPS-induced TNF-α mRNA expression nor did a PPARγ antagonist, GW9662, alter the repression of TNF-α mRNA in LPS-stimulated cells pretreated with 15d-PGJ2 suggesting a PPARγ-independent inhibition of TNF-α mRNA in THP-1 cells. Transfection studies with a reporter construct and subsequent treatment with 15d-PGJ2 demonstrated a dose-dependent inhibition of the TNF-α promoter. Additional studies demonstrated that inhibition of histone deacetylases with trichostatin A (TSA) or overexpression of histone acetyltransferase CBP could overcome 15d-PGJ2-mediated repression of the TNF-α promoter, suggesting that an important mechanism whereby 15d-PGJ2 suppresses a cytokine is through factors that regulate histone modifications. To examine the endogenous TNF-α promoter, chromatin immunoprecipitations (ChIP) were performed. ChIP assays demonstrated that LPS stimulation induced an increase in histone H3 and H4 acetylation at the TNF-α promoter, which was reduced in cells pretreated with 15d-PGJ2. These results highlight the ability of acetylation and deacetylation factors to affect the TNF-α promoter and demonstrate that an additional important mechanism whereby 15d-PGJ2 mediates TNF-α transcriptional repression by altering levels of acetylated histone H3 and H4 at its promoter

  20. Repeated Short-term (2h×14d) Emotional Stress Induces Lasting Depression-like Behavior in Mice.

    Science.gov (United States)

    Kim, Kyoung-Shim; Kwon, Hye-Joo; Baek, In-Sun; Han, Pyung-Lim

    2012-03-01

    Chronic behavioral stress is a risk factor for depression. To understand chronic stress effects and the mechanism underlying stress-induced emotional changes, various animals model have been developed. We recently reported that mice treated with restraints for 2 h daily for 14 consecutive days (2h-14d or 2h×14d) show lasting depression-like behavior. Restraint provokes emotional stress in the body, but the nature of stress induced by restraints is presumably more complex than emotional stress. So a question remains unsolved whether a similar procedure with "emotional" stress is sufficient to cause depression-like behavior. To address this, we examined whether "emotional" constraints in mice treated for 2h×14d by enforcing them to individually stand on a small stepping platform placed in a water bucket with a quarter full of water, and the stress evoked by this procedure was termed "water-bucket stress". The water-bucket stress activated the hypothalamus-pituitary-adrenal gland (HPA) system in a manner similar to restraint as evidenced by elevation of serum glucocorticoids. After the 2h×14d water-bucket stress, mice showed behavioral changes that were attributed to depression-like behavior, which was stably detected >3 weeks after last water-bucket stress endorsement. Administration of the anti-depressant, imipramine, for 20 days from time after the last emotional constraint completely reversed the stress-induced depression-like behavior. These results suggest that emotional stress evokes for 2h×14d in mice stably induces depression-like behavior in mice, as does the 2h×14d restraint.

  1. Synthesis and Crystal Structure of an Unprecedented Supramolecular Complex[Co(μ2-ClO4)2(H2O)22MA

    Institute of Scientific and Technical Information of China (English)

    XU,Jing; BAI,Zhengshuai; SUN,Weiyin

    2009-01-01

    A new supramolecular framework[Co(μ2-C104)2(H2O)22MA(1)[MA=melamine(C3H6N6)]has been syn-thesized by a hydrothermal method.Interestingly,there ale inorganic and organic building blocks with two different supramolecular synthons:(a)2D(4,4)network constructed by infinite inorganic 1D chains through interchain hy-drogen bonding interactions;(b)1D zigzag organic chains formed by hydrogen bonds, which further stack up through,ππ-interactions between the two adjacent MA molecules.The entire structure of 1 is a 3D supramolecular framework resulting from the presence of abundant hydrogen bonds between infinite[CO(μ2-C1O4)2(H2O)2]n chains and zigzag MA chains in different sheets.1 gives a nice example of supramolecular framework based on non-covalent interactions including hydrogen bonding and π-π interactions.

  2. Fabrication of 2D SnS2/g-C3N4 heterojunction with enhanced H2 evolution during photocatalytic water splitting.

    Science.gov (United States)

    Liu, Enzhou; Chen, Jibing; Ma, Yongning; Feng, Juan; Jia, Jia; Fan, Jun; Hu, Xiaoyun

    2018-08-15

    In this work, the 2D SnS 2 /g-C 3 N 4 heterojunctions were successfully prepared by heating the homogeneous dispersion of SnS 2 nanosheets and g-C 3 N 4 nanosheets using a microwave muffle. SEM, TEM and HRTEM images indicated that the SnS 2 nanosheets were loaded on the surface of the g-C 3 N 4 nanosheets. The UV-vis spectra show that the absorption intensity of the as-prepared samples was increased and the absorption range was also extended from 420 nm to approximately 600 nm. The H 2 production rate over 5 wt% SnS 2 /g-C 3 N 4 can reach 972.6 μmol·h -1 ·g -1 under visible light irradiation (λ > 420 nm) using TEOA as the sacrifice agent and Pt as the electron trap, which is 2.9 and 25.6 times higher than those of the pristine g-C 3 N 4 and SnS 2 , respectively. According to the obtained PL spectra, photocurrent and EIS spectra, the enhanced performance for H 2 generation over the heterojunctions is primarily ascribed to the rapid charge transfer arising from the suitable band gap positions leading to an improved photocatalytic performance. The recycling experiments indicated that the as-prepared composites exhibit good stability in H 2 production. Additionally, a possible enhanced mechanism for H 2 evolution was deduced based on the results obtained by various characterization techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Theoretical study of H2/+/ spectroscopic properties. II, III. [2p and 3d excited electronic states

    Science.gov (United States)

    Beckel, C. L.; Shafi, M.; Peek, J. M.

    1973-01-01

    Description of the theoretical spectroscopic properties of the 2p pi/sub u/ and 3d sigma/sub g/ excited states of the H2/+/ hydrogen molecular ion. Numerical integration of the Schrodinger equation is used to determine vibration-rotation eigenvalues. Dunham power series expansions are used to determine the equilibrium separation, potential coefficients, and spectroscopic constants. The eigenvalues are used to determine delta-G, Bv, Dv, and Hv.

  4. Convenient synthesis of 2,2-Dimethyl-3,4-dihydro-2 H-pyrano[2,3- b]quinolines

    Digital Repository Service at National Institute of Oceanography (India)

    Parsekar, S.B.; Amonkar, C.P.; Parameswaran, P.S.; Tilve, S.G.

    A convenient general synthesis of 2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]quinolines using the Wittig reaction is described. The o-nitrobenzaldehydes (1a-d) on reaction with phosphorane 2 provided (E)-ethyl-a-(2,2-dimethylprop-2-ene)-2...

  5. Investigation of the Direct Charge Transfer in Low Energy D2+ + H Collisions using Merged-Beams Technique

    Science.gov (United States)

    Romano, S. L.; Guillen, C. I.; Andrianarijaona, V. M.; Havener, C. C.

    2011-10-01

    The hydrogen - hydrogen (deuterium) molecular ion is the most fundamental ion-molecule two-electron system. Charge transfer (CT) for H2+ on H, which is one of the possible reaction paths for the (H-H2)+ system, is of special interest because of its contribution to H2 formation in the early universe, its exoergicity, and rich collision dynamics. Due to technical difficulty in making an atomic H target, the direct experimental investigations of CT for H2+ on H are sparse and generally limited to higher collision energies. The measurements of the absolute cross section of different CT paths for H2+ on H over a large range of collision energy are needed to benchmark theoretical calculations, especially the ones at low energies. The rate coefficient of CT at low energy is not known but may be comparable to other reaction rate coefficients in cold plasmas with H, H+, H2+, and H3+ as constituents. For instance, CT for H2+ on H and the following H3+ formation reaction H2+ + H2H + H3+ are clearly rate interdependent although it was always assumed that every ionization of H2 will lead to the formation of H3+. CT proceeds through dynamically coupled electronic, vibrational and rotational degrees of freedom. One can depict three paths, electronic CT, CT with nuclear substitution, and CT with dissociation. Electronic CT and CT with nuclear substitution in the H2+ on H collisions are not distinguishable by any quantum theory. Here we use the isotopic system (D2+ - H) to measure without ambiguity the electronic CT cross section by observing the H+ products. Using the ion-atom merged-beam apparatus at Oak Ridge National Laboratory, the absolute direct CT cross sections for D2+ + H from keV/u to meV/u collision energies have been measured. The molecular ions are extracted from an Electron-Cyclotron Resonance (ECR) ion source with a vibrational state distribution which is most likely determined by Frank-Condon transitions between ground state D2 and D2+. A ground-state H beam

  6. Preparation of deuteriated adipic [2H2]-, [2H4]-, [2H6]-, and [2H8]-acids by use of Kolbe electrolysis as a key reaction

    International Nuclear Information System (INIS)

    Tashiro, Masahi; Tsuzuki, Hirohisa; Mataka, Shuntaro; Goto, Hideyuki; Ogasahara, Shoji

    1990-01-01

    Using Kolbe electrolysis of methyl hydrogen [ 2 H 0 ]-, [ 2 H 2 ]-, and [ 2 H 4 ]-succinates as a key reaction, adipic [2,2- 2 H 2 ]-, [2,3- 2 H 2 ]-, [2,2,3,3- 2 H 4 ]-, [2,3,4,5- 2 H 4 ]-, [2,3,5,5- 2 H 4 ]-, [2,2,3,3,5,5- 2 H 6 ]-, and [2,2,3,3,4,4,5,5- 2 H 8 ]-acids were prepared in high deuterium contents. (author)

  7. SYNTHESIS OF DERIVATIVES OF 8H-INDENO[1,2-D]THIAZOL-2-AMINES VIA α-BROMO, α,α-DIBROMO AND α-TOSYLOXY CARBONYL COMPOUNDS Synthese von Derivaten 8H-INDENO [1,2-d] thiazol-2-AMINE VIA α-BROMO, α, α-DIBROMO UND α-Tosyloxy CARBONYLVERBINDUNGEN

    OpenAIRE

    Deepak K. Aneja and Om Prakash

    2012-01-01

    The present study described the synthesis of derivatives of 8H-indeno[1,2-d]thiazol-2- amines (5) by the reaction of thiourea with 2-tosyloxy-1-indanone (3), 2-bromo-2,3- dihydroinden-1-ones (6) and 2,2-dibromo-2,3-dihydroinden-1-one (7) in fairly good to excellent yields (90-95%).

  8. Kinetic isotope effects in the CH4 + H→CH3 + H2 system. Predictions of the LMR six-body potential-energy reaction hypersurface

    International Nuclear Information System (INIS)

    Marriott, T.D.

    1976-01-01

    Scope of Study: The purpose of this study was two-fold. First, it served to test, in part, the usefulness of the LMR six-body potential-energy surface (LMR-PES) for transition-state theory predictions of the kinetic isotope effects for both the forward and reverse reactions of CH 4 + H reversible CH 3 + H 2 . In this regard the agreement between experimental and theoretical isotope effects, assuming the former to be accurate, provides information about the accuracy of the curvature of the potential energy surface for motion both parallel and perpendicular to the reaction coordinate. Second, these isotope effects were used to assess the validity of a number of qualitative and semi-quantitative interpretations of kinetic isotope effects developed in physical organic chemistry with regard to this reaction system. The force constants and geometries obtained numerically from the LMR-PES were found to produce reasonable harmonic approximations to the reactant normal mode frequencies. Neglecting tunneling, the LMR-PES reasonably reproduces the experimental k/sub H//k/sub D/ values for the reactions CH 4 + H(D), CH 3 + HD(DH) and CD 2 + HD(DH). Since previous theoretical treatments of primary deuterium kinetic isotope effects have neglected the bending normal mode frequencies, a semi-quantitative study of the effect of neglecting bending frequencies on the VP, EXC, and ZPE elements as well as the transition-state theory kinetic isotope effects was performed. The Swain-Schaad relationship between primary deuterium and tritium kinetic isotope effects was shown to hold to a reasonable degree of accuracy for the LMR-PES reaction system. A relationship between 13-carbon and 14-carbon kinetic isotope effects similar to the Swain-Schaad relationship was derived

  9. Supercooling of natural water, heavy water and of the blends H2O-D2O

    International Nuclear Information System (INIS)

    Lafargue, C.; Babin, L.; Clausse, D.; Lere-Porte, M.; Broto, F.

    1975-01-01

    It is shown that the coherency of the results of various measurements on water freezing temperatures proves that freezing temperatures must be dependent on the structure of the supercooled liquid. Recent experiments that confirm this interpretation are described: study of the stability of supercooled water as a function of time at fixed temperature, study of the influence of various thermal treatments on the behavior of supercooled water, study of the supercooling of heavy water and of D 2 O-H 2 O blends [fr

  10. 2D 1H -13C Heteronuclear Shift Correlation Of 2a - Hydroxy Aiantolactone From Pulicaria Undulata C.A. Mey

    Directory of Open Access Journals (Sweden)

    A. Rustaiyan

    1992-07-01

    Full Text Available We have reported recently the isolation and characterization of several sesquiterpene lactones from Pulicaria undulata (1."nThe lactones were isolated from an Et20 - Petrol (1:3 fraction by different chromatographic techniques including HPLC (RP 8, MeOH - H2O, 13:7."nIn this way three eudesmanolides 1 - 3, a guaianolide 4, a nor -guaianolide 5, as well as the pseudoguaianolide 6 and the xanthanolide 7 were isolated. One of the eudesmanolides (2a - hydroxy aiantolactone, 1, was present as the main component."nSuch lactones being known as biologically active substances, we have decided to describe for the first time a detailed interpretation of proton, 1H -NMR, 13C - NMR and 2D lH -13C - heteronuclear shift correlation spectra of 2a - hydroxy aiantolactone. The stereochemistry of C - 2 , C - 7 and C - 8 was determined by the NOESY experiments, H - 7 and H - 8 are in the a configuration and H - 2 is in the b configuration.

  11. Characterization of Runella slithyformis HD-Pnk, a Bifunctional DNA/RNA End-Healing Enzyme Composed of an N-Terminal 2′,3′-Phosphoesterase HD Domain and a C-Terminal 5′-OH Polynucleotide Kinase Domain

    Science.gov (United States)

    Munir, Annum

    2016-01-01

    ABSTRACT 5′- and 3′-end-healing reactions are key steps in nucleic acid break repair in which 5′-OH ends are phosphorylated by a polynucleotide kinase (Pnk) and 3′-PO4 or 2′,3′-cyclic-PO4 ends are hydrolyzed by a phosphoesterase to generate the 5′-PO4 and 3′-OH termini required for sealing by classic polynucleotide ligases. End-healing and sealing enzymes are present in diverse bacterial taxa, often organized as modular units within a single multifunctional polypeptide or as subunits of a repair complex. Here we identify and characterize Runella slithyformis HD-Pnk as a novel bifunctional end-healing enzyme composed of an N-terminal 2′,3′-phosphoesterase HD domain and a C-terminal 5′-OH polynucleotide kinase P-loop domain. HD-Pnk phosphorylates 5′-OH polynucleotides (9-mers or longer) in the presence of magnesium and any nucleoside triphosphate donor. HD-Pnk dephosphorylates RNA 2′,3′-cyclic phosphate, RNA 3′-phosphate, RNA 2′-phosphate, and DNA 3′-phosphate ends in the presence of a transition metal cofactor, which can be nickel, copper, or cobalt. HD-Pnk homologs are present in genera from 11 bacterial phyla and are often encoded in an operon with a putative ATP-dependent polynucleotide ligase. IMPORTANCE The present study provides insights regarding the diversity of nucleic acid repair strategies via the characterization of Runella slithyformis HD-Pnk as the exemplar of a novel clade of dual 5′- and 3′-end-healing enzymes that phosphorylate 5′-OH termini and dephosphorylate 2′,3′-cyclic-PO4, 3′-PO4, and 2′-PO4 ends. The distinctive feature of HD-Pnk is its domain composition, i.e., a fusion of an N-terminal HD phosphohydrolase module and a C-terminal P-loop polynucleotide kinase module. Homologs of Runella HD-Pnk with the same domain composition, same domain order, and similar polypeptide sizes are distributed widely among genera from 11 bacterial phyla. PMID:27895092

  12. Gas phase 1H NMR studies and kinetic modeling of dihydrogen isotope equilibration catalyzed by Ru-nanoparticles under normal conditions: dissociative vs. associative exchange.

    Science.gov (United States)

    Limbach, Hans-Heinrich; Pery, Tal; Rothermel, Niels; Chaudret, Bruno; Gutmann, Torsten; Buntkowsky, Gerd

    2018-04-25

    The equilibration of H2, HD and D2 between the gas phase and surface hydrides of solid organic-ligand-stabilized Ru metal nanoparticles has been studied by gas phase 1H NMR spectroscopy using closed NMR tubes as batch reactors at room temperature and 800 mbar. When two different nanoparticle systems, Ru/PVP (PVP ≡ polyvinylpyrrolidone) and Ru/HDA (HDA ≡ hexadecylamine) were exposed to D2 gas, only the release of HD from the hydride containing surface could be detected in the initial stages of the reaction, but no H2. In the case of Ru/HDA also the reverse experiment was performed where surface deuterated nanoparticles were exposed to H2. In that case, the conversion of H2 into gaseous HD was detected. In order to analyze the experimental kinetic and spectroscopic data, we explored two different mechanisms taking into account potential kinetic and equilibrium H/D isotope effects. Firstly, we explored the dissociative exchange mechanism consisting of dissociative adsorption of dihydrogen, fast hydride surface diffusion and associative desorption of dihydrogen. It is shown that if D2 is the reaction partner, only H2 will be released in the beginning of the reaction, and HD only in later reaction stages. The second mechanism, dubbed here associative exchange consists of the binding of dihydrogen to Ru surface atoms, followed by a H-transfer to or by H-exchange with an adjacent hydride site, and finally of the associative desorption of dihydrogen. In that case, in the exchange with D2, only HD will be released in the beginning of the reaction. Our experimental results are not compatible with the dissociative exchange but can be explained in terms of the associative exchange. Whereas the former will dominate at low temperatures and pressures, the latter will prevail around room temperature and normal pressures where transition metal nanoparticles are generally used as reaction catalysts.

  13. Designing an Epithermal Neutron Beam for Boron Neutron Capture Therapy for the Fusion Reactions 2H(d,n)3He and 3H(d,n)4He1

    International Nuclear Information System (INIS)

    Verbeke, J.M.; Costes, S.V.; Bleuel, D.; Vujic, J.; Leung, K.N.

    1998-01-01

    A beam shaping assembly has been designed to moderate high energy neutrons from the fusion reactions 2 H(d,N) 3 He and 3 H(d,n) 4 He for use fin boron neutron capture therapy. The low neutron yield of the 2 H(d,n) 3 He reaction led to unacceptably long treatment times. However, a 160 mA deuteron beam of energy 400 keV led to a treatment time of 120 minutes with the reaction 3 H(d,n) 4 He. Equivalent doses of 9.6 Gy-Eq and 21.9 Gy-Eq to the skin and to a 8 cm deep tumor respectively have been computed

  14. Requirements for charged-particle reaction cross sections in the d-d, d-t, t-t, and d-3He fuel cycles

    International Nuclear Information System (INIS)

    Jarmie, N.

    1986-12-01

    This paper reviews the status of experimental data and data evaluations for charged-particle reactions of interest in fusion-reactor design. In particular, the 2 H(t,α)n, 2 H(d,p) 3 H, 2 H(d, 3 He)n, 3 H(t,α)nn and 3 He(d,p) 4 He reactions at low energies are studied. Other secondary reactions are considered. The conclusion is that such cross sections are well known for the near and medium term, and that no crucial experimental lack exists. There is a serious lack of standard evaluations of these reactions, which should be in an internationally acceptable format and easily accessible. Support for generating such evaluations should be given serious consideration

  15. Functionalization of liquid-exfoliated two-dimensional 2H-MoS2.

    Science.gov (United States)

    Backes, Claudia; Berner, Nina C; Chen, Xin; Lafargue, Paul; LaPlace, Pierre; Freeley, Mark; Duesberg, Georg S; Coleman, Jonathan N; McDonald, Aidan R

    2015-02-23

    Layered two-dimensional (2D) inorganic transition-metal dichalchogenides (TMDs) have attracted great interest as a result of their potential application in optoelectronics, catalysis, and medicine. However, methods to functionalize and process such 2D TMDs remain scarce. We have established a facile route towards functionalized layered MoS2 . We found that the reaction of liquid-exfoliated 2D MoS2 , with M(OAc)2 salts (M=Ni, Cu, Zn; OAc=acetate) yielded functionalized MoS2 -M(OAc)2 materials. Importantly, this method furnished the 2H-polytype of MoS2 which is a semiconductor. X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT-IR), and thermogravimetric analysis (TGA) provide strong evidence for the coordination of MoS2 surface sulfur atoms to the M(OAc)2 salt. Interestingly, functionalization of 2H-MoS2 allows for its dispersion/processing in more conventional laboratory solvents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Accurate analytic model potentials for D2 and H2 based on the perturbed-Morse--oscillator model

    International Nuclear Information System (INIS)

    Huffaker, J.N.; Cohen, D.I.

    1986-01-01

    Model potentials with as few as 19 free parameters are fitted to published ab initio abiabatic potentials for D 2 and H 2 , with accuracy such that rovibrational eigenvalues are in error by only about 10 -2 cm -1 . A three-parameter model is suggested for describing nonadiabatic effects on eigenvalues, with the intention that such a model might be suitable for all hydrides. Dunham coefficients are calculated from the perturbed-Morse--oscillator series expansion of the model, permitting a critical evaluation of convergence properties of both the Dunham series and the WKB series

  17. Design, Synthesis, Antibacterial and Antifungal Activity of Novel 2-[(E-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4- dihydro-4-quinolinones

    Directory of Open Access Journals (Sweden)

    Anisetti Ravinder Nath

    2012-01-01

    Full Text Available The novel 2-[(E-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4- dihydro-4-quinolinones (4a-j analogs were synthesized by Knoevenagel condensation of a solution of 2-methyl-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4-dihydro-4-quinazolinone (3 with aromatic aldehyde in presence of catalytic amount of piperidine. Compounds (4a-j showed significant biological activity against all the standard strains. All the synthesized compounds were characterized on the basis of their IR, 1H NMR, MASS spectroscopic data and elemental analyses. All the compounds have been tested for antimicrobial and antifungal activity by the cup-plate method.

  18. HD-DVD: the next consumer electronics revolution?

    Science.gov (United States)

    Topiwala, Pankaj N.

    2003-11-01

    The DVD is emerging as one of the world's favorite consumer electronics product, rapidly replacing analog videotape in the US and many other markets at prodigious rates. It is capable of offering a full feature-length, standard-definition movie in crisp rendition on TV. TV technology is itself in the midst of switching from analog to digital TV, with high-definition being the main draw. In fact, the US government has been advocating that switch over to digital TC, with both carrot and stick approaches, for nearly two decades, with only modest results--about 2% penetration. Under FCC herding, broadcasters are falling in the digital line--slowly, and sans profit. Meanwhile, delivery of HD content on portable media would be a great solution. Indeed, a new disk technology based on blue lasers is coming; but its widespread adoption may yet be four to five yeras away. But a promising new video codec--H.264/MPEG-4 AVC, the latest coding standard jointly developed by the Video Coding Experts Group (VCEG) of ITU-T and Moving Picture Experts Group (MPEG) of ISO/IEC, just might be the missing link. It offers substantial coding gains over MPEG-2, used in today's DVDs. With H.264, it appears possible to put HD movies on today's red-laser DVDs. Since consumers love DVDs, and HD--when they can see it, can H.264 and HD-DVD ignite a new revolution, now? It may have a huge impact on (H)DTV adoption rates.

  19. cis- and trans-2,3,3a,4,5,9b-Hexahydro-1H-benz[e]indoles: synthesis and evaluation of dopamine D2, and D3 receptor binding affinity

    DEFF Research Database (Denmark)

    Song, Xiaodong; Crider, Michael A.; Cruse, Sharon F.

    1999-01-01

    cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz [e]indoles were synthesized as conformationally rigid analogues of 3-phenylpyrrolidine and evaluated for dopamine (DA) D2S and D3 receptor binding affinity. The tricyclic benz[e]indole nucleus was constructed by a previously reported reductive...... configuration. These novel ligands may be useful tools for gaining additional information about the DA D3 receptor. Copyright Elsevier, Paris.dopamine / D2S receptor / D3 receptor / cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz[e]indoles / receptor binding affinity....... receptors was shown by compounds substituted with N-n-propyl or N-allyl groups. The cis-(+-)-N-allyl derivative 21e demonstrated a D2S/D3 selectivity of 290. Resolution of cis-(+-)-5 and trans-(+-)- 21c into individual enantiomers showed that in both series the more active isomer had 3aR absolute...

  20. Tricyclic sesquiterpene copaene prevents H2O2-induced neurotoxicity

    Directory of Open Access Journals (Sweden)

    Hasan Turkez

    2014-02-01

    Full Text Available Aim: Copaene (COP, a tricyclic sesquiterpene, is present in several essential oils of medicinal and aromatic plants and has antioxidant and anticarcinogenic features. But, very little information is known about the effects of COP on oxidative stress induced neurotoxicity. Method: We used hydrogen peroxide (H2O2 exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of COP in H2O2-induced toxicity in rat cerebral cortex cell cultures for the first time. For this purpose, methyl thiazolyl tetrazolium (MTT and lactate dehydrogenase (LDH release assays were carried out to evaluate cytotoxicity. Total antioxidant capacity (TAC and total oxidative stress (TOS parameters were used to evaluate oxidative changes. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG levels, the single cell gel electrophoresis (SCGE or comet assay was also performed for measuring the resistance of neuronal DNA to H2O2-induced challenge. Result: The results of this study showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage increased in the H2O2 alone treated cultures. But pre-treatment of COP suppressed the cytotoxicity, genotoxicity and oxidative stress which were increased by H2O2. Conclusion: It is proposed that COP as a natural product with an antioxidant capacity in mitigating oxidative injuries in the field of neurodegenerative diseases. [J Intercult Ethnopharmacol 2014; 3(1.000: 21-28

  1. Effect of hydration on the amide I band in the binary solvents dioxane-D2O and dioxane-H2O

    International Nuclear Information System (INIS)

    Kobayashi, M.; Kobayashi, M.

    1980-01-01

    Hydration of amides in aqueous solutions has been studied by measuring the infrared spectra of amides (benzamide, p-methoxybenzamide, and ropionamide) in dioxane-D 2 O and dioxane-H 2 O mixtures. The absorption due to the C=O stretching (or amide I band) exhibited a very remarkable red shift accompanied by a characteristic change of the band shape as the water content in the medium increased. The spectral change is attributed to the change of the hydration state at the carbonyl oxygen. In the aqueous mixtures, amide molecules participate in an equilibrium among various states of hydration. The weighted mean frequency of the ν/sub C = O/ absorption, anti ν/sub C = O/, varied in proportion to the water contained in the medium. The difference between the anti ν/sub C = O/ value in pure water and that in pure dioxane,Δ anti ν, was used as a measure of the maximum degree of hydration. It was larger for propionamide than for the aromatic amides, suggesting that the steric effect of the substituents is of major importance in hydration. The isotope effect, Δ anti ν/sub D 2 O//Δ anti ν/sub H 2 O/, in the range from 1.4 to 1.6 for all cases examined, indicated that stronger hydration of amides occurred with D 2 O than with H 2 O

  2. Cellular localization of 2-[3H]deoxy-D-glucose from paraffin-embedded brains

    International Nuclear Information System (INIS)

    Durham, D.; Woolsey, T.A.; Kruger, L.

    1981-01-01

    Results of experiments in which regional neuronal activity is revealed by a 2-[ 3 H]deoxy-D-glucose ( 3 H-2-DG)-paraffin section-emulsion autoradiography method are described. The trigeminal pathway of freely behaving mice was activated differentially by selective patterns of whisker removal. One hour after injection of concentrated 3 H-2-DG, the animals were perfused systemically with a periodate/lysine/paraformaldehyde mixture the brains were embedded in paraffin, and serial sections were taken and coated with emulsion for autoradiography. Diffusion of the isotope out of the tissue was assessed visually and by liquid scintillation counting. While substantial loss of 3 H isotope into the embedding fluids (about 95%) was found, the scintillation counts and the autoradiograms showed good fixation of the isotope in situ, no evidence of isotope movement into the emulsion, and no gradients of diffusion in the sectioned material. Patterns of regional labeling were similar to those reported from brains prepared by conventional 2-[ 14 C]deoxy-D-glucose ( 14 C-2-DG) autoradiography; Trigeminal structures associated with the intact (stimulated) whiskers were labeled relatively heavily, indicating that label uptake is specific with respect to neuronal activity. In the cortex, the patterns of label corresponded directly and precisely to those barrels known to receive inputs from the intact whiskers. Distribution of silver grains in the cortex and in the brainstem was correlated directly with neuronal profiles. Clearly, this approach offers considerable technical advantages, in particular, the ease with which the histological material is prepared. The resolution of the autoradiograms and the quality of the histology are excellent

  3. Biokinetic Analysis and Metabolic Fate of 2,4-D in 2,4-D-Resistant Soybean (Glycine max).

    Science.gov (United States)

    Skelton, Joshua J; Simpson, David M; Peterson, Mark A; Riechers, Dean E

    2017-07-26

    The Enlist weed control system allows the use of 2,4-D in soybean but slight necrosis in treated leaves may be observed in the field. The objectives of this research were to measure and compare uptake, translocation, and metabolism of 2,4-D in Enlist (E, resistant) and non-AAD-12 transformed (NT, sensitive) soybeans. The adjuvant from the Enlist Duo herbicide formulation (ADJ) increased 2,4-D uptake (36%) and displayed the fastest rate of uptake (U 50 = 0.2 h) among treatments. E soybean demonstrated a faster rate of 2,4-D metabolism (M 50 = 0.2 h) compared to NT soybean, but glyphosate did not affect 2,4-D metabolism. Metabolites of 2,4-D in E soybean were qualitatively different than NT. Applying 2,4-D-ethylhexyl ester instead of 2,4-D choline (a quaternary ammonium salt) eliminated visual injury to E soybean, likely due to the time required for initial de-esterification and bioactivation. Excessive 2,4-D acid concentrations in E soybean resulting from ADJ-increased uptake may significantly contribute to foliar injury.

  4. Theoretical Time Dependent Thermal Neutron Spectra and Reaction Rates in H{sub 2}O and D{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Purohit, S N

    1966-04-15

    The early theoretical and experimental time dependent neutron thermalization studies were limited to the study of the transient spectrum in the diffusion period. The recent experimental measurements of the time dependent thermal neutron spectra and reaction rates, for a number of moderators, have generated considerable interest in the study of the time dependent Boltzmann equation. In this paper we present detailed results for the time dependent spectra and the reaction rates for resonance detectors using several scattering models of H{sub 2}O and D{sub 2}O. This study has been undertaken in order to interpret the integral time dependent neutron thermalization experiments in liquid moderators which have been performed at the AB Atomenergi. The proton gas and the deuteron gas models are inadequate to explain the measured reaction rates in H{sub 2}O and D{sub 2}O. The bound models of Nelkin for H{sub 2}O and of Butler for D{sub 2}O give much better agreement with the experimental results than the gas models. Nevertheless, some disagreement between theoretical and experimental results still persists. This study also indicates that the bound model of Butler and the effective mass 3. 6 gas model of Brown and St. John give almost identical reaction rates. It is also surprising to note that the calculated reaction rate for Cd for the Butler model appears to be in better agreement with the experimental results of D{sub 2}O than of the Nelkin model with H{sub 2}O experiments. The present reaction rate studies are sensitive enough so as to distinguish between the gas model and the bound model of a moderator. However, to investigate the details of a scattering law (such as the effect of the hindered rotations in H{sub 2}O and D{sub 2}O and the weights of different dynamical modes) with the help of these studies would require further theoretical as well as experimental investigations. Theoretical results can be further improved by improving the source for thermal neutrons, the

  5. Selective labelling of dopamine (D2) receptors in rat striatum by [3H]domperidone but not by [3H]spiperone

    International Nuclear Information System (INIS)

    Lazareno, S.; Nahorski, S.R.

    1982-01-01

    Specific binding of [ 3 H]spiperone and [ 3 H]domperidone, displaceable by 1 μM d-butaclamol, was examined in rat striatal membranes. Initial saturation and displacement experiments indicated that [ 3 H]spiperone bound to more sites than [ 3 H]domperidone and that, whilst all displacing drugs were more potent against [ 3 H]domperidone, this difference in potency was greatest for dopamine agonists and specific antagonists and least for 5HT-related drugs. Sulpiride displaced [ 3 H]spiperone biphasically, and was used at a concentration of 50 μM to examine two classes of [ 3 H]spiperone binding: site 1 displaceable by sulpiride, and site 2 displaceable by butaclamol but not by sulpiride. Site 1 had twice the capacity of site 2 and ten times the affinity for [ 3 H]spiperone. Dopaminergic drugs displaced preferentially from site 1, whilst 5HT-related drugs were more potent against site 2. GTP reduced the potency of dopamine, noradrenaline and, to a lesser extent, 5HT at site 1, but had no effect at site 2. [ 3 H]Domperidone sites had the same capacity as [ 3 H]spiperone site 1, and dopamine, noradrenaline and 5HT, in the absence or presence of GTP, and sulpiride had essentially identical affinities for [ 3 H]domperidone sites and [ 3 H]spiperone site 1. It is concluded that [ 3 H]domperidone and [ 3 H]spiperone label an identical population of dopamine (D 2 ) receptors, whilst [ 3 H]spiperone also labels a substantial number of non-dopamine sites, at least some of which are 5TH-related. [ 3 H]Domperidone is the better radioligand for dopamine receptors. (Auth.)

  6. Ab initio calculation of the transition-state properties and addition rate constants for H + C2H2 and selected isotopic analogues

    International Nuclear Information System (INIS)

    Harding, L.B.; Wagner, A.F.; Bowman, J.M.; Schatz, G.C.; Christoffel, K.

    1982-01-01

    GVB-POL-CI ab initio calculations of the geometries, energetics, and normal mode frequencies of C 2 H 2 , C 2 H 3 , and the transition state for the addition reaction of H + C 2 H 2 are presented. In addition, normal mode frequencies for the isotopic variants D + C 2 D 2 , D + C 2 H 2 , and H + C 2 D 2 are preented. These results are compared to experimental values for C 2 H 2 and to ab initio values of Hagase and Kern, and semiempirical values of Keil, Lynch, Cowfer, and Michael. The results are also used to calculate the apparent bimolecular addition rate constant using conventional RRKM theory for chemical activation. The calculated rate constants and their isotopic variants are compared as a function of temperature and pressure to available experimental information. The agreement is little different from that obtained by Keil et al. with a similar calculation using semiempirical values for acetylene, transition-state, and vinyl radical properties. In particular, the calculated high-pressure limit of the rate constant appears to be at least 1 order of magnitude higher than the experimental limit. Several possible reasons for this discrepancy are discussed

  7. Syntheses of 4-aminobutanoic acid-2,2-/sup 2/H/sub 2/ and -4,4-/sup 2/H/sub 2/ and progabide-2,2-/sup 2/H/sub 2/ and -4,4-/sup 2/H/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Davis, B.

    1987-10-01

    4-Aminobutanoic acid-2,2-/sup 2/H/sub 2/ and -4,4-/sup 2/H/sub 2/ were synthesized in high yield with high deuterium incorporation, and then converted into the corresponding deuterium-labelled anti-convulsant drug, progabide, by means of a transimination reaction.

  8. Hyperpolarized H2O MR angiography

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, Jan Henrik; Laustsen, Christoffer; Bowen, Sean

    2014-01-01

    polarization followed by dissolution in D2O. A water 1H signal enhancement of 77 times compared with 4.7 Tesla was obtained. This corresponds to a polarization of 3.5% for the 3.9 mol/L 1H in D2O . Moreover, a T1 in excess of 20 s was achieved. The use of hyperpolarized water as a contrast agent presents a new...

  9. COMPARISON OF 2D AND 3D VIDEO DISPLAYS FOR TEACHING VITREORETINAL SURGERY.

    Science.gov (United States)

    Chhaya, Nisarg; Helmy, Omar; Piri, Niloofar; Palacio, Agustina; Schaal, Shlomit

    2017-07-11

    To compare medical students' learning uptake and understanding of vitreoretinal surgeries by watching either 2D or 3D video recordings. Three vitreoretinal procedures (tractional retinal detachment, exposed scleral buckle removal, and four-point scleral fixation of an intraocular lens [TSS]) were recorded simultaneously with a conventional recorder for two-dimensional viewing and a VERION 3D HD system using Sony HVO-1000MD for three-dimensional viewing. Two videos of each surgery, one 2D and the other 3D, were edited to have the same content side by side. One hundred UMass medical students randomly assigned to a 2D group or 3D, then watched corresponding videos on a MacBook. All groups wore BiAL Red-blue 3D glasses and were appropriately randomized. Students filled out questionnaires about surgical steps or anatomical relationships of the pathologies or tissues, and their answers were compared. There was no significant difference in comprehension between the two groups for the extraocular scleral buckle procedure. However, for the intraocular TSS and tractional retinal detachment videos, the 3D group performed better than 2D (P < 0.05) on anatomy comprehension questions. Three-dimensional videos may have value in teaching intraocular ophthalmic surgeries. Surgical procedure steps and basic ocular anatomy may have to be reviewed to ensure maximal teaching efficacy.

  10. Drosophila TRPA1 isoforms detect UV light via photochemical production of H2O2

    Science.gov (United States)

    Guntur, Ananya R.; Gu, Pengyu; Takle, Kendra; Chen, Jingyi; Xiang, Yang; Yang, Chung-Hui

    2015-01-01

    The transient receptor potential A1 (TRPA1) channel is an evolutionarily conserved detector of temperature and irritant chemicals. Here, we show that two specific isoforms of TRPA1 in Drosophila are H2O2 sensitive and that they can detect strong UV light via sensing light-induced production of H2O2. We found that ectopic expression of these H2O2-sensitive Drosophila TRPA1 (dTRPA1) isoforms conferred UV sensitivity to light-insensitive HEK293 cells and Drosophila neurons, whereas expressing the H2O2-insensitive isoform did not. Curiously, when expressed in one specific group of motor neurons in adult flies, the H2O2-sensitive dTRPA1 isoforms were as competent as the blue light-gated channelrhodopsin-2 in triggering motor output in response to light. We found that the corpus cardiacum (CC) cells, a group of neuroendocrine cells that produce the adipokinetic hormone (AKH) in the larval ring gland endogenously express these H2O2-sensitive dTRPA1 isoforms and that they are UV sensitive. Sensitivity of CC cells required dTRPA1 and H2O2 production but not conventional phototransduction molecules. Our results suggest that specific isoforms of dTRPA1 can sense UV light via photochemical production of H2O2. We speculate that UV sensitivity conferred by these isoforms in CC cells may allow young larvae to activate stress response—a function of CC cells—when they encounter strong UV, an aversive stimulus for young larvae. PMID:26443856

  11. Tropospheric water vapour isotopologue data (H216O, H218O, and HD16O) as obtained from NDACC/FTIR solar absorption spectra

    Science.gov (United States)

    Barthlott, Sabine; Schneider, Matthias; Hase, Frank; Blumenstock, Thomas; Kiel, Matthäus; Dubravica, Darko; García, Omaira E.; Sepúlveda, Eliezer; Mengistu Tsidu, Gizaw; Takele Kenea, Samuel; Grutter, Michel; Plaza-Medina, Eddy F.; Stremme, Wolfgang; Strong, Kim; Weaver, Dan; Palm, Mathias; Warneke, Thorsten; Notholt, Justus; Mahieu, Emmanuel; Servais, Christian; Jones, Nicholas; Griffith, David W. T.; Smale, Dan; Robinson, John

    2017-01-01

    We report on the ground-based FTIR (Fourier transform infrared) tropospheric water vapour isotopologue remote sensing data that have been recently made available via the database of NDACC (Network for the Detection of Atmospheric Composition Change; MUSICA/" target="_blank">ftp://ftp.cpc.ncep.noaa.gov/ndacc/MUSICA/) and via doi:10.5281/zenodo.48902. Currently, data are available for 12 globally distributed stations. They have been centrally retrieved and quality-filtered in the framework of the MUSICA project (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water). We explain particularities of retrieving the water vapour isotopologue state (vertical distribution of H216O, H218O, and HD16O) and reveal the need for a new metadata template for archiving FTIR isotopologue data. We describe the format of different data components and give recommendations for correct data usage. Data are provided as two data types. The first type is best-suited for tropospheric water vapour distribution studies disregarding different isotopologues (comparison with radiosonde data, analyses of water vapour variability and trends, etc.). The second type is needed for analysing moisture pathways by means of H2O, δD-pair distributions.

  12. Near ultraviolet photodissociation spectroscopy of Mn{sup +}(H{sub 2}O) and Mn{sup +}(D{sub 2}O)

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, Wright L.; Copeland, Christopher; Kocak, Abdulkadir; Sallese, Zachary; Metz, Ricardo B., E-mail: rbmetz@chem.umass.edu [Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003 (United States)

    2014-11-28

    The electronic spectra of Mn{sup +}(H{sub 2}O) and Mn{sup +}(D{sub 2}O) have been measured from 30 000 to 35 000 cm{sup −1} using photodissociation spectroscopy. Transitions are observed from the {sup 7}A{sub 1} ground state in which the Mn{sup +} is in a 3d{sup 5}4s{sup 1} electronic configuration, to the {sup 7}B{sub 2} (3d{sup 5}4p{sub y}) and {sup 7}B{sub 1} (3d{sup 5}4p{sub x}) excited states with T{sub 0} = 30 210 and 32 274 cm{sup −1}, respectively. Each electronic transition has partially resolved rotational and extensive vibrational structure with an extended progression in the metal−ligand stretch at a frequency of ∼450 cm{sup −1}. There are also progressions in the in-plane bend in the {sup 7}B{sub 2} state, due to vibronic coupling, and the out-of-plane bend in the {sup 7}B{sub 1} state, where the calculation illustrates that this state is slightly non-planar. Electronic structure computations at the CCSD(T)/aug-cc-pVTZ and TD-DFT B3LYP/6-311++G(3df,3pd) level are also used to characterize the ground and excited states, respectively. These calculations predict a ground state Mn-O bond length of 2.18 Å. Analysis of the experimentally observed vibrational intensities reveals that this bond length decreases by 0.15 ± 0.015 Å and 0.14 ± 0.01 Å in the excited states. The behavior is accounted for by the less repulsive p{sub x} and p{sub y} orbitals causing the Mn{sup +} to interact more strongly with water in the excited states than the ground state. The result is a decrease in the Mn-O bond length, along with an increase in the H-O-H angle. The spectra have well resolved K rotational structure. Fitting this structure gives spin-rotation constants ε{sub aa}″ = −3 ± 1 cm{sup −1} for the ground state and ε{sub aa}′ = 0.5 ± 0.5 cm{sup −1} and ε{sub aa}′ = −4.2 ± 0.7 cm{sup −1} for the first and second excited states, respectively, and A′ = 12.8 ± 0.7 cm{sup −1} for the first excited state. Vibrationally mediated

  13. Computational study on the mechanisms and energetics of trimethylindium reactions with H2O and H2S.

    Science.gov (United States)

    Raghunath, P; Lin, M C

    2007-07-19

    The reactions of trimethylindium (TMIn) with H2O and H2S are relevant to the chemical vapor deposition of indium oxide and indium sulfide thin films. The mechanisms and energetics of these reactions in the gas phase have been investigated by density functional theory and ab initio calculations using the CCSD(T)/[6-31G(d,p)+Lanl2dz]//B3LYP/[6-31G(d,p)+Lanl2dz] and CCSD(T)/[6-31G(d,p)+Lanl2dz] //MP2/[6-31G(d,p)+Lanl2dz] methods. The results of both methods are in good agreement for the optimized geometries and relative energies. When TMIn reacts with H2O and H2S, initial molecular complexes [(CH3)3In:OH2 (R1)] and [(CH3)3In:SH2 (R2)] are formed with 12.6 and 3.9 kcal/mol binding energies. Elimination of a CH4 molecule from each complex occurs with a similar energy barrier at TS1 (19.9 kcal/mol) and at TS3 (22.1 kcal/mol), respectively, giving stable intermediates (CH3)2InOH and (CH3)2InSH. The elimination of the second CH4 molecule from these intermediate products, however, has to overcome very high and much different barriers of 66.1 and 53.2 kcal/mol, respectively. In the case of DMIn with H2O and H2S reactions, formation of both InO and InS is exothermic by 3.1 and 30.8 kcal/mol respectively. On the basis of the predicted heats of formation of R1 and R2 at 0 K and -20.1 and 43.6 kcal/mol, the heats of formation of (CH3)2InOH, (CH3)2InSH, CH3InO, CH3InS, InO, and InS are estimated to be -20.6, 31.8, and 29.0 and 48.4, 35.5, and 58.5 kcal/mol, respectively. The values for InO and InS are in good agreement with available experimental data. A similar study on the reactions of (CH3)2In with H2O and H2S has been carried out; in these reactions CH3InOH and CH3InSH were found to be the key intermediate products.

  14. Diffusion Monte Carlo studies of MB-pol (H{sub 2}O){sub 2−6} and (D{sub 2}O){sub 2−6} clusters: Structures and binding energies

    Energy Technology Data Exchange (ETDEWEB)

    Mallory, Joel D.; Mandelshtam, Vladimir A. [Department of Chemistry, University of California, Irvine, California 92697 (United States)

    2016-08-14

    We employ the diffusion Monte Carlo (DMC) method in conjunction with the recently developed, ab initio-based MB-pol potential energy surface to characterize the ground states of small (H{sub 2}O){sub 2−6} clusters and their deuterated isotopomers. Observables, other than the ground state energies, are computed using the descendant weighting approach. Among those are various spatial correlation functions and relative isomer fractions. Interestingly, the ground states of all clusters considered in this study, except for the dimer, are delocalized over at least two conformations that differ by the orientation of one or more water monomers with the relative isomer populations being sensitive to the isotope substitution. Most remarkably, the ground state of the (H{sub 2}O){sub 6} hexamer is represented by four distinct cage structures, while that of (D{sub 2}O){sub 6} is dominated by the prism, i.e., the global minimum geometry, with a very small contribution from a prism-book geometry. In addition, for (H{sub 2}O){sub 6} and (D{sub 2}O){sub 6}, we performed DMC calculations to compute the ground states constrained to the cage and prism geometries. These calculations compared results for three different potentials, MB-pol, TTM3/F, and q-TIP4P/F.

  15. Spectroscopic studies of O-type binaries. IV. HD 165052 and Hd 167771

    International Nuclear Information System (INIS)

    Morrison, N.D.; Conti, P.S.

    1978-01-01

    HD 165052, O6.5 V, and HD 167771, 07.5 III ((f)), are double-lined binaries with periods of six and four days, respectively, and velocity semiamplitudes near 100 km s -1 . In our spectroscopic orbital analysis, we investigated the effect of correcting the measured radial velocities for pair blending. The derived velocity amplitudes are increased by roughly 7%, and hence the minimum masses increase by 20%--255. The raw data lead to minimum masses, m sin 3 i, between 2 and 3 mD/sub sun/. Since normal O stars are thought to have masses greater than 20 m/sub sun/, the orbits must be highly inclined to the line of sight. From the luminosities and effective temperatures we derived stellar radii. For HD 167771, the requirement that neither component over fill it Roche lobe implies that each has a mass in the neighborhood of 30m/sub sun/ or larger

  16. H{sub 2} R and D activities in the Nordic Countries

    Energy Technology Data Exchange (ETDEWEB)

    Holst Joergensen, B.

    2003-10-01

    The report describes hydrogen related R and D activities in the five Nordic countries from 1998 and onwards. It is not a comprehensive account of all hydrogen related R and D as much relevant research is not described under the heading of hydrogen energy but integrated in other programmes or part of more generic basic research. Also much industry conducted H2 R and D activities are not published. It gives some background information on R and D in the five Nordic countries and gives account of the R and D efforts. At Nordic level through the Nordic Energy Research a number of R and D projects are also conducted and shortly described. At EU level, Nordic stakeholders are represented in a number of hydrogen and fuel cell R and D projects and short descriptions are provided. In the appendix, more detaield informaiton is given on the R and D projects at national, EU and Nordic levels. (au)

  17. Strong Metal Support Interaction of Pt and Ru Nanoparticles Deposited on HOPG Probed by the H-D Exchange Reaction

    DEFF Research Database (Denmark)

    Fiordaliso, Elisabetta M.; Dahl, Søren; Chorkendorff, Ib

    2012-01-01

    The interaction between metals and support is investigated in the case of 50 Å Pt and 50 Å Ru films deposited on a HOPG substrate. The films are prepared by electron beam physical vapor deposition and annealed in UHV to temperatures up to 700 °C. The equilibrium hydrogen exchange rate between...... adsorbed and gas phase at 1 bar is measured before and after annealing. The rate is measured in the temperature range of 40–200 °C at 1 bar, by utilization of the H-D exchange reaction. Experiments are performed on fresh cleaved and sputtered HOPG, which give similar results. We find that annealing...... the films from 150 up to 700 °C increases the amount of carbon present in the films up to 95%, as derived by surface analysis, indicating the formation of a carbon layer on top of the metal films. The exchange rate decreases dramatically with increasing carbon content on the films for both metals, pointing...

  18. Lightweight hydrogen-storage material Mg0.65Sc0.35D2 studied with 2H and 2H–{45Sc} MAS NMR exchange spectroscopy

    NARCIS (Netherlands)

    Srinivasan, S.; Magusin, P.C.M.M.

    2011-01-01

    Using double-quantum 2H MAS NMR with 45Sc recoupling and Bloch–Siegert compensated 2H–{45Sc} TRAPDOR we have identified the overlapping NMR signals of deuterium with and without scandium neighbors in Mg0.65Sc0.35D2, a candidate lightweight material for hydrogen storage. At room temperature we also

  19. dKDM2 couples histone H2A ubiquitylation to histone H3 demethylation during Polycomb group silencing

    NARCIS (Netherlands)

    A. Lagarou (Anna); A.B. Mohd Sarip; Y.M. Moshkin (Yuri); G.E. Chalkley (Gillian); K. Bezstarosti (Karel); J.A.A. Demmers (Jeroen); C.P. Verrijzer (Peter)

    2008-01-01

    textabstractTranscription regulation involves enzyme-mediated changes in chromatin structure. Here, we describe a novel mode of histone crosstalk during gene silencing, in which histone H2A monoubiquitylation is coupled to the removal of histone H3 Lys 36 dimethylation (H3K36me2). This pathway was

  20. Predissociation of the D /sup 1/PIsub(u) state of H/sub 2/ near threshold

    Energy Technology Data Exchange (ETDEWEB)

    Borondo, F.; Eguiagaray, L.R.; Riera, A. (Universidad Autonoma de Madrid (Spain). Dept. de Quimica Fisica y Quimica Cuantica)

    1982-03-28

    A recent calculation of Komarov and Ostrovsky (J. Phys. B.; 12:2485 (1979)) seemed to have settled a controversy regarding the different experimental values of the H(2s)/H(2p) sharing ratio in the predissociation of the D /sup 1/PIsub(u) state of H/sub 2/ near threshold. This calculation was based on a correct physical picture of the dissociation process, but the dynamical treatment rests on invalid assumptions. In the present work, a more rigorous quantum mechanical treatment is presented, and a branching ratio of 0.70 is obtained.

  1. Reaction Coordinate Leading to H2 Production in [FeFe]-Hydrogenase Identified by Nuclear Resonance Vibrational Spectroscopy and Density Functional Theory.

    Science.gov (United States)

    Pelmenschikov, Vladimir; Birrell, James A; Pham, Cindy C; Mishra, Nakul; Wang, Hongxin; Sommer, Constanze; Reijerse, Edward; Richers, Casseday P; Tamasaku, Kenji; Yoda, Yoshitaka; Rauchfuss, Thomas B; Lubitz, Wolfgang; Cramer, Stephen P

    2017-11-22

    [FeFe]-hydrogenases are metalloenzymes that reversibly reduce protons to molecular hydrogen at exceptionally high rates. We have characterized the catalytically competent hydride state (H hyd ) in the [FeFe]-hydrogenases from both Chlamydomonas reinhardtii and Desulfovibrio desulfuricans using 57 Fe nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT). H/D exchange identified two Fe-H bending modes originating from the binuclear iron cofactor. DFT calculations show that these spectral features result from an iron-bound terminal hydride, and the Fe-H vibrational frequencies being highly dependent on interactions between the amine base of the catalytic cofactor with both hydride and the conserved cysteine terminating the proton transfer chain to the active site. The results indicate that H hyd is the catalytic state one step prior to H 2 formation. The observed vibrational spectrum, therefore, provides mechanistic insight into the reaction coordinate for H 2 bond formation by [FeFe]-hydrogenases.

  2. Structurally characterized 1,1,3,3-tetramethylguanidine solvated magnesium aryloxide complexes: [Mg(mu-OEt)(DBP)(H-TMG)]2, [Mg(mu-OBc)(DBP)(H-TMG)]2, [Mg(mu-TMBA)(DBP)(H-TMG)]2, [Mg(mu-DPP)(DBP)(H-TMG)]2, [Mg(BMP)2(H-TMG)2], [Mg(O-2,6-Ph2C6H3)2 (H-TMG)2].

    Science.gov (United States)

    Monegan, Jessie D; Bunge, Scott D

    2009-04-06

    The synthesis and structural characterization of several 1,1,3,3-tetramethylguanidine (H-TMG) solvated magnesium aryloxide complexes are reported. Bu(2)Mg was successfully reacted with H-TMG, HOC(6)H(3)(CMe(3))(2)-2,6 (H-DBP), and either ethanol, a carboxylic acid, or diphenyl phosphate in a 1:1 ratio to yield the corresponding [Mg(mu-L)(DBP)(H-TMG)](2) where L = OCH(2)CH(3) (OEt, 1), O(2)CC(CH(3))(3) (OBc, 2), O(2)C(C(6)H(2)-2,4,6-(CH(3))(3)) (TMBA, 3), or O(2)P(OC(6)H(5))(2) (DPP, 4). Bu(2)Mg was also reacted with two equivalents of H-TMG and HOC(6)H(3)(CMe(3))-2-(CH(3))-6 (BMP) or HO-2,6-Ph(2)C(6)H(3) to yield [Mg(BMP)(2)(H-TMG)(2)] (5) and [Mg(O-2,6-Ph(2)C(6)H(3))(2)(H-TMG)(2)] (6). Compounds 1-6 were characterized by single-crystal X-ray diffraction. Polymerization of l- and rac-lactide with 1 was found to generate polylactide (PLA). A discussion concerning the relevance of compounds 2 - 4 to the structure of Mg-activated phosphatase enzymes is also provided. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FT-IR spectroscopy, and (1)H, (13)C and (31)P NMR studies.

  3. Association equilibrium constants and populations of clusters (H2O)n(g) and (D2O)n(g): differences between isotopomers and a possible relation to isotope enrichment

    International Nuclear Information System (INIS)

    Slanina, Z.

    1986-01-01

    Equilibrium constants of H 2 O(g) and D 2 O(g) associations to clusters (H 2 O) n (g) and (D 2 O) n (g) were calculated on the basis of the ab initio SCF CI MCY-B water-water pair potential. Populations of the components of equilibrium cluster mixtures were evaluated at various temperatures and pressures for both isotopomeric series. Differences between the H and D steam are pointed out and possible consequences are discussed. (author)

  4. Dopamine D2 receptors in the cerebral cortex: Distribution and pharmacological characterization with [3H]raclopride

    International Nuclear Information System (INIS)

    Lidow, M.S.; Goldman-Rakic, P.S.; Rakic, P.; Innis, R.B.

    1989-01-01

    An apparent involvement of dopamine in the regulation of cognitive functions and the recognition of a widespread dopaminergic innervation of the cortex have focused attention on the identity of cortical dopamine receptors. However, only the presence and distribution of dopamine D 1 receptors in the cortex have been well documented. Comparable information on cortical D 2 sites is lacking. The authors report here the results of binding studied in the cortex and neostriatum of rat and monkey using the D 2 selective antagonist [ 3 H]raclopride. In both structures [ 3 H]raclopride bound in a sodium-dependent and saturable manner to a single population of sites with pharmacological profiles of dopamine D 2 receptors. D 2 sites were present in all regions of the cortex, although their density was much lower than in the neostriatum. The density of these sites in both monkey and, to a lesser extent, rat cortex displayed a rostral-caudal gradient with highest concentrations in the prefrontal and lowest concentrations in the occipital cortex, corresponding to dopamine levels in these areas. Thus, the present study established the presence and widespread distribution of dopamine D 2 receptors in the cortex

  5. Hallucinogenic 5-HT2AR agonists LSD and DOI enhance dopamine D2R protomer recognition and signaling of D2-5-HT2A heteroreceptor complexes.

    Science.gov (United States)

    Borroto-Escuela, Dasiel O; Romero-Fernandez, Wilber; Narvaez, Manuel; Oflijan, Julia; Agnati, Luigi F; Fuxe, Kjell

    2014-01-03

    Dopamine D2LR-serotonin 5-HT2AR heteromers were demonstrated in HEK293 cells after cotransfection of the two receptors and shown to have bidirectional receptor-receptor interactions. In the current study the existence of D2L-5-HT2A heteroreceptor complexes was demonstrated also in discrete regions of the ventral and dorsal striatum with in situ proximity ligation assays (PLA). The hallucinogenic 5-HT2AR agonists LSD and DOI but not the standard 5-HT2AR agonist TCB2 and 5-HT significantly increased the density of D2like antagonist (3)H-raclopride binding sites and significantly reduced the pKiH values of the high affinity D2R agonist binding sites in (3)H-raclopride/DA competition experiments. Similar results were obtained in HEK293 cells and in ventral striatum. The effects of the hallucinogenic 5-HT2AR agonists on D2R density and affinity were blocked by the 5-HT2A antagonist ketanserin. In a forskolin-induced CRE-luciferase reporter gene assay using cotransfected but not D2R singly transfected HEK293 cells DOI and LSD but not TCB2 significantly enhanced the D2LR agonist quinpirole induced inhibition of CRE-luciferase activity. Haloperidol blocked the effects of both quinpirole alone and the enhancing actions of DOI and LSD while ketanserin only blocked the enhancing actions of DOI and LSD. The mechanism for the allosteric enhancement of the D2R protomer recognition and signalling observed is likely mediated by a biased agonist action of the hallucinogenic 5-HT2AR agonists at the orthosteric site of the 5-HT2AR protomer. This mechanism may contribute to the psychotic actions of LSD and DOI and the D2-5-HT2A heteroreceptor complex may thus be a target for the psychotic actions of hallunicogenic 5-HT2A agonists. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Antioxidative potential of Duranta repens (linn.) fruits against H 2 O 2 ...

    African Journals Online (AJOL)

    The effects of Duranta repens fruits were investigated on H2O2 induced oxidative cell death to evaluate its antioxidative potential in vitro. HEK293T cells were treated with different concentrations [0-1000 ìg/ ml] of ethanol extract (E-Ex) and methanol extract (M-Ex) of D. repens for 24h, and then treated with 100 ìM H2O2 for ...

  7. The synthesis of [2-3H2] taurine and [2-3H2] hypotaurine

    International Nuclear Information System (INIS)

    Fellman, J.H.

    1981-01-01

    The synthesis of [2- 3 H 2 ]-2-aminoethanesulfonate [2- 3 H]-taurine by the reduction of cyanomethanesulfonic acid with tritium gas is described. The conversion of [2- 3 H]-taurine and its 14 C and 35 S isotopic forms to 2-aminoethanesulfinate (hypotaurine) was accomplished by converting taurine to its corresponding sulfonyl chloride and reducing the latter with metallic zinc. (author)

  8. 2D Numerical Simulation and Sensitive Analysis of H-Darrieus Wind Turbine

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad E. Saryazdi

    2018-02-01

    Full Text Available Recently, a lot of attention has been devoted to the use of Darrieus wind turbines in urban areas. The aerodynamics of a Darrieus turbine are very complex due to dynamic stall and changing forces on the turbine triggered by changing horizontal angles. In this study, the aerodynamics of H-rotor vertical axis wind turbine (VAWT has been studied using computational fluid dynamics via two different turbulence models. Shear stress transport (SST k-ω turbulence model was used to simulate a 2D unsteady model of the H-Darrieus turbine. In order to complete this simulation, sensitivity analysis of the effective turbine parameters such as solidity factor, airfoil shape, wind velocity and shaft diameter were done. To simulate the flow through the turbine, a 2D simplified computational domain has been generated. Then fine mesh for each case consisting of different turbulence models and dimensions has been generated. Each mesh in this simulation dependent on effective parameters consisted of domain size, mesh quality, time step and total revolution. The sliding mesh method was applied to evaluate the unsteady interaction between the stationary and rotating components. Previous works just simulated turbine, while in our study sensitivity analysis of effective parameters was done. The simulation results closely match the experimental data, providing an efficient and reliable foundation to study wind turbine aerodynamics. This also demonstrates computing the best value of the effective parameter. The sensitivity analysis revealed best value of the effective parameter that could be used in the process of designing turbine. This work provides the first step in developing an accurate 3D aerodynamic modeling of Darrieus wind turbines. Article History: Received :August 19th 2017; Received: December 15th 2017; Accepted: Januari 14th 2018; Available online How to Cite This Article: Saryazdi, S. M. E. and Boroushaki, M. (2018 2D Numerical Simulation and Sensitive

  9. Hydrogen-atom tunneling through a very high barrier; spontaneous thiol → thione conversion in thiourea isolated in low-temperature Ar, Ne, H2 and D2 matrices.

    Science.gov (United States)

    Rostkowska, Hanna; Lapinski, Leszek; Nowak, Maciej J

    2018-05-23

    Spontaneous thiol → thione hydrogen-atom transfer has been investigated for molecules of thiourea trapped in Ar, Ne, normal-H2 (n-H2) and normal-D2 (n-D2) low-temperature matrices. The most stable thione isomer was the only form of the compound present in the matrices after their deposition. According to MP2/6-311++G(2d,p) calculations, the thiol tautomer should be higher in energy by 62.5 kJ mol-1. This less stable thiol form of the compound was photochemically generated in a thione → thiol process, occurring upon UV irradiation of the matrix. Subsequently, a very slow spontaneous conversion of the thiol tautomer into the thione form was observed for the molecules isolated in Ar, Ne, n-H2 and n-D2 matrices kept at 3.5 K and in the dark. Since the thiol → thione transformation in thiourea is a process involving the dissociation of a chemical bond, the barrier for this hydrogen-atom transfer is very high (104-181 kJ mol-1). Crossing such a high potential-energy barrier at a temperature as low as 3.5 K, is possible only by hydrogen-atom tunneling. The experimentally measured time constants of this tunneling process: 52 h (Ar), 76 h (Ne), 94 h (n-H2) and 94 h (n-D2), do not differ much from one another. Hence, the dependence of the tunneling rate on the matrix environment is not drastic. The progress of the thiol → thione conversion was also monitored for Ar matrices at different temperature: 3.5 K, 9 K and 15 K. For this temperature range, the experiments revealed no detectable temperature dependence of the rate of the tunneling process.

  10. H2-H2O-HI Hydrogen Separation in H2-H2O-HI Gaseous Mixture Using the Silica Membrane

    International Nuclear Information System (INIS)

    Pandiangan, Tumpal

    2002-01-01

    It was evaluated aiming at the application for hydrogen iodide decomposition in the thermochemical lS process. Porous alumina tube having pore size of 0.1 μm was modified by chemical vapor deposition using tetraethoxysilane. The permeance single gas of He, H 2 , and N 2 was measured at 300-600 o C. Hydrogen permeance of the modified membrane at a permeation temperature of 600 o C was about 5.22 x 10 -08 mol/Pa m 2 s, and 3.