Science.gov

Sample records for dependent deuterium fractionation

  1. Deuterium Fractionation just after the Star Formation

    NASA Astrophysics Data System (ADS)

    Shibata, D.; Sakai, N.; Yamamoto, S.

    2013-10-01

    We have recently conducted a five-point strip observation of the DCO+, H13CO+, DNC, HN13C, and N2H+ lines toward low mass Class I protostar L1551 IRS5, and have evaluated the deuterium fractionation ratios DCO+/HCO+ and DNC/HNC. The DCO+/HCO+ ratio is found to be lower toward the protostar position than those toward the adjacent positions. On the other hand, the DNC/HNC ratio does not show such a decrease toward the protostar position. This suggests that the deuterium fractionation ratio of the neutral species is conserved after the star formation. If so, the deuterium fractionation of the neutral species can be used as a novel tracer to investigate the initial condition of the star formation process.

  2. Deuterium fractionation in the Ophiuchus molecular cloud

    NASA Astrophysics Data System (ADS)

    Punanova, A.; Caselli, P.; Pon, A.; Belloche, A.; André, Ph.

    2016-03-01

    Context. In cold (T< 25 K) and dense (nH> 104 cm-3) interstellar clouds, molecules such as CO are significantly frozen onto dust grain surfaces. Deuterium fractionation is known to be very efficient in these conditions as CO limits the abundance of H3+, which is the starting point of deuterium chemistry. In particular, N2D+ is an excellent tracer of dense and cold gas in star-forming regions. Aims: We measure the deuterium fraction, RD, and the CO depletion factor, fd, towards a number of starless and protostellar cores in the L1688 region of the Ophiuchus molecular cloud complex and search for variations based upon environmental differences across L1688. The kinematic properties of the dense gas traced by the N2H+ and N2D+ (1-0) lines are also discussed. Methods: Deuterium fraction has been measured via observations of the J = 1-0 transition of N2H+ and N2D+ towards 33 dense cores in different regions of L1688. We estimated the CO depletion factor using C17O(1-0) and 850 μm dust continuum emission from the SCUBA survey. We carried out all line observations with the IRAM 30 m antenna. Results: The dense cores show large (≃2-40%) deuterium fractions with significant variations between the sub-regions of L1688. The CO depletion factor also varies from one region to another (between ≃1 and 7). Two different correlations are found between deuterium fraction and CO depletion factor: cores in regions A, B2, and I show increasing RD with increasing fd, similar to previous studies of deuterium fraction in pre-stellar cores; cores in regions B1, B1B2, C, E, F, and H show a steeper RD - fd correlation with large deuterium fractions occurring in fairly quiescent gas with relatively low CO freeze-out factors. These are probably recently formed, centrally concentrated starless cores, which have not yet started the contraction phase towards protostellar formation. We also find that the deuterium fraction is affected by the amount of turbulence, dust temperature, and

  3. Isotopic Anomalies in Primitive Solar System Matter: Spin-State Dependent Fractionation of Nitrogen and Deuterium in Interstellar Clouds

    NASA Technical Reports Server (NTRS)

    Wirstrom, Eva S.; Charnley, Steven B.; Cordiner, Martin A.; Milan, Stefanie N.

    2012-01-01

    Organic material found in meteorites and interplanetary dust particles is enriched in D and N-15, This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule chemistry in the protosolar core. Theoretical models of interstellar fractionation at low temperatures predict large enrichments in both D and N-15 and can account for the largest isotop c enrichments measured in carbonaceous meteorites, However, more recent measurements have shown that, in some primitive samples, a large N-15 enrichment does not correlate with one in D, and that some D-enriched primitive material displays little, if any, N-15 enrichment. By considering the spin-state dependence in ion-molecule reactions involving the ortho and para forms of H2, we show that ammonia and related molecules can exhibit such a wide range of fractionation for both N-15 and D in dense cloud cores, We also show that while the nitriles, HCN and HNC, contain the greatest N-15 enrichment, this is not expected to correlate with extreme D emichment. These calculations therefore support the view that Solar System N-15 and D isotopic anomalies have an interstellar heritage, We also compare our results to existing astronomical observations and briefly discuss future tests of this model.

  4. ISOTOPIC ANOMALIES IN PRIMITIVE SOLAR SYSTEM MATTER: SPIN-STATE-DEPENDENT FRACTIONATION OF NITROGEN AND DEUTERIUM IN INTERSTELLAR CLOUDS

    SciTech Connect

    Wirstroem, Eva S.; Cordiner, Martin A.; Charnley, Steven B.; Milam, Stefanie N.

    2012-09-20

    Organic material found in meteorites and interplanetary dust particles is enriched in D and {sup 15}N. This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule chemistry in the protosolar nebula. Theoretical models of interstellar fractionation at low temperatures predict large enrichments in both D and {sup 15}N and can account for the largest isotopic enrichments measured in carbonaceous meteorites. However, more recent measurements have shown that, in some primitive samples, a large {sup 15}N enrichment does not correlate with one in D, and that some D-enriched primitive material displays little, if any, {sup 15}N enrichment. By considering the spin-state dependence in ion-molecule reactions involving the ortho and para forms of H{sub 2}, we show that ammonia and related molecules can exhibit such a wide range of fractionation for both {sup 15}N and D in dense cloud cores. We also show that while the nitriles, HCN and HNC, contain the greatest {sup 15}N enrichment, this is not expected to correlate with extreme D enrichment. These calculations therefore support the view that solar system {sup 15}N and D isotopic anomalies have an interstellar heritage. We also compare our results to existing astronomical observations and briefly discuss future tests of this model.

  5. Isotopic Anomalies in Primitive Solar System Matter: Spin-State-Dependent Fractionation of Nitrogen and Deuterium in Interstellar Clouds

    NASA Technical Reports Server (NTRS)

    Wirstrom, Eva S.; Charnley, Steven B.; Cordiner, Martin A.; Milam, Stefanie N.

    2012-01-01

    Organic material found in meteorites and interplanetary dust particles is enriched in D and N-15. This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule chemistry in the protosolar nebula, Theoretical models of interstellar fractionation at low temperatures predict large enrichments in both D and N-15 and can account for the largest isotopic enrichments measured in carbonaceous meteorites. However, more recent measurements have shown that, in some primitive samples, a large N-15 enrichment does not correlate with one in D, and that some D-enriched primitive material displays little, if any, N-15 enrichment. By considering the spin-state dependence in ion-molecule reactions involving the ortho and para forms of H2, we show that ammonia and related molecules can exhibit such a wide range of fractionation for both N-15 and D in dense cloud cores. We also show that while the nitriles, HCN and HNC, contain the greatest N=15 enrichment, this is not expected to correlate with extreme D enrichment. These calculations therefore support the view that solar system N-15 and D isotopic anomalies have an interstellar heritage. We also compare our results to existing astronomical observations and briefly discuss future tests of this model.

  6. Isotopic Anomalies in Primitive Solar System Matter: Spin-state Dependent Fractionation of Nitrogen and Deuterium in Interstellar Clouds

    NASA Astrophysics Data System (ADS)

    Charnley, Steven B.; Wirstrom, E. S.; Cordiner, M. A.; Milam, S. N.

    2012-10-01

    Organic material found in meteorites and interplanetary dust particles is enriched in D and 15N. This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule chemistry in the protosolar core [1]. Theoretical models of interstellar fractionation at low temperatures predict large enrichments in both D and 15N and can account for the largest isotopic enrichments measured in carbonaceous meteorites. However, more recent measurements have shown that, in some primitive samples, a large 15N enrichment does not correlate with one in D, and that some D-enriched primitive material displays little, if any, 15N enrichment. By considering the spin-state dependence in ion-molecule reactions involving the ortho and para forms of H2, we show that ammonia and related molecules can exhibit such a wide range of fractionation for both 15N and D in dense cloud cores. We also show that while the nitriles, HCN and HNC, contain the greatest 15N enrichment, this is not expected to correlate with extreme D enrichment. These calculations therefore support the view that Solar System 15N and D isotopic anomalies have an interstellar heritage. We also compare our results to existing astronomical observations and briefly discuss future tests of this model. [1] Mumma, M. J. and Charnley, S.B. (2011), ARA&A, 49, 471.

  7. Deuterium fractionation in the Horsehead edge

    NASA Astrophysics Data System (ADS)

    Pety, J.; Goicoechea, J. R.; Hily-Blant, P.; Gerin, M.; Teyssier, D.

    2007-03-01

    Context: Deuterium fractionation is known to enhance the [ DCO^+] /[ HCO^+] abundance ratio over the D/H ˜ 10-5 elemental ratio in the cold and dense gas typically found in pre-stellar cores. Aims: We report the first detection and mapping of very bright DCO^+J=3-2 and J=2-1 lines (3 and 4 K respectively) towards the Horsehead photodissociation region (PDR) observed with the IRAM-30m telescope. The DCO+ emission peaks close to the illuminated warm edge of the nebula (<50'' or ~0.1 pc away). Methods: Detailed nonlocal, non-LTE excitation and radiative transfer analyses have been used to determine the prevailing physical conditions and to estimate the DCO+ and H13CO+ abundances from their line intensities. Results: A large [ DCO^+] /[ HCO^+] abundance ratio (≥0.02) is inferred at the DCO+ emission peak, a condensation shielded from the illuminating far-UV radiation field where the gas must be cold (10-20 K) and dense (≥ 2 × 105 cm-3). DCO+ is not detected in the warmer photodissociation front, implying a lower [ DCO^+] /[ HCO^+] ratio (<10-3). Conclusions: .According to our gas phase chemical predictions, such a high deuterium fractionation of HCO+ can only be explained if the gas temperature is below 20 K, in good agreement with DCO+ excitation calculations. Based on observations obtained with the IRAM Plateau de Bure interferometer and 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

  8. Calculations of ion-molecule deuterium fractionation reactions involving HD

    NASA Technical Reports Server (NTRS)

    Maluendes, Sergio A.; Mclean, A. D.; Herbst, Eric

    1992-01-01

    Gas-phase chemical models of deuterium fractionation in dense interstellar clouds utilize a small number of exothermic reactions to achieve fractionation. Although HD is a major repository of deuterium, it appears not to exchange deuterium with many molecular ions. Useful semiquantitative reasons have been given for the unusual lack of reactivity of exothermic ion-HD deuterium exchange systems, but quantum chemical studies are needed to understand these ideas in more detail and to determine if the lack of reactivity pertains at very low temperatures not studied in the laboratory, or whether tunneling can drive the reactions. Accordingly, the potential energy surfaces of three representative ion-molecule exchange reactions involving protonated ions and HD have been investigated with ab initio quantum chemical techniques. Our results generally confirm the semiquantitative picture as to which reactions are likely to occur and show that tunneling at low temperatures is unlikely to alter this picture.

  9. Calculations of ion-molecule deuterium fractionation reactions involving HD

    NASA Technical Reports Server (NTRS)

    Maluendes, Sergio A.; Mclean, A. D.; Herbst, Eric

    1992-01-01

    Gas-phase chemical models of deuterium fractionation in dense interstellar clouds utilize a small number of exothermic reactions to achieve fractionation. Although HD is a major repository of deuterium, it appears not to exchange deuterium with many molecular ions. Useful semiquantitative reasons have been given for the unusual lack of reactivity of exothermic ion-HD deuterium exchange systems, but quantum chemical studies are needed to understand these ideas in more detail and to determine if the lack of reactivity pertains at very low temperatures not studied in the laboratory, or whether tunneling can drive the reactions. Accordingly, the potential energy surfaces of three representative ion-molecule exchange reactions involving protonated ions and HD have been investigated with ab initio quantum chemical techniques. Our results generally confirm the semiquantitative picture as to which reactions are likely to occur and show that tunneling at low temperatures is unlikely to alter this picture.

  10. The Gas-Phase Deuterium Fractionation of Formaldehyde

    NASA Astrophysics Data System (ADS)

    Osamura, Yoshihiro; Roberts, Helen; Herbst, Eric

    2005-03-01

    The dominant mechanism for the deuteration of formaldehyde in the gas phase of low-temperature interstellar cloud cores occurs via reaction with the deuterating ions H2D+, HD+2, and D+3. Until now, it has been assumed that deuteration leads to an ion that, on recombination with electrons, can produce a deuterated neutral species with a statistical branching fraction. Quantum chemical calculations reported here, however, show an entirely different picture, in which the deuteration of formaldehyde leads to the molecular ion H2COD+, where the deuterium binds only on the oxygen side of the molecule. The structure is quite stable, while an alternative structure, H2DCO+, cannot be produced in a straightforward manner. Dissociative recombination of H2COD+ to reproduce a formaldehyde structure then removes the deuteration if the dissociation is direct, i.e., it occurs without change of structure. There are several possible indirect mechanisms by which dissociative recombination can lead to HDCO, however. For example, if the direct products are HCOD+H, it is possible that subsequent isomerization to HDCO can occur, although this involved process is unlikely. Another possibility is isomerization during the actual dissociation of the H2COD intermediate. Models of deuterium fractionation in which dissociative recombination is predominantly direct are presented, and it is found that the deuterium fractionation of formaldehyde to form both HDCO and D2CO can still occur via other mechanisms, although with less efficiency than previously obtained. If the dissociative recombination is half indirect, however, then we can recover the previously calculated efficiency.

  11. Chemical fractionation of deuterium in the protosolar nebula

    NASA Astrophysics Data System (ADS)

    Kalvāns, J.; Shmeld, I.; Kalnin, J. R.; Hocuk, S.

    2017-01-01

    Understanding gas-grain chemistry of deuterium in star-forming objects may help to explain their history and present state. We aim to clarify how processes in ices affect the deuterium fractionation. In this regard, we investigate a Solar-mass protostellar envelope using an astrochemical rate-equation model that considers bulk-ice chemistry. The results show a general agreement with the molecular D/H abundance ratios observed in low-mass protostars. The simultaneous processes of ice accumulation and rapid synthesis of HD on grain surfaces in the prestellar core hampers the deuteration of icy species. The observed very high D/H ratios exceeding 10 per cent, i.e., super-deuteration, are reproduced for formaldehyde and dimethyl ether, but not for other species in the protostellar envelope phase. Chemical transformations in bulk ice lower D/H ratios of icy species and do not help explaining the super-deuteration. In the protostellar phase, the D2O/HDO abundance ratio was calculated to be higher than the HDO/H2O ratio owing to gas-phase chemistry. Species that undergo evaporation from ices have high molecular D/H ratio and a high gas-phase abundance.

  12. Chemical fractionation of deuterium in the protosolar nebula

    NASA Astrophysics Data System (ADS)

    Kalvāns, J.; Shmeld, I.; Kalnin, J. R.; Hocuk, S.

    2017-05-01

    Understanding the gas-grain chemistry of deuterium in star-forming objects may help to explain their history and present state. We aim to clarify how processes in ices affect the deuterium fractionation. In this regard, we investigate a Solar-mass protostellar envelope using an astrochemical rate-equation model that considers bulk-ice chemistry. The results show a general agreement with the molecular D/H abundance ratios observed in low-mass protostars. The simultaneous processes of ice accumulation and rapid synthesis of HD on grain surfaces in the pre-stellar core hamper the deuteration of icy species. The observed very high D/H ratios exceeding 10 per cent, i.e. super-deuteration, are reproduced for formaldehyde and dimethyl ether, but not for other species in the protostellar envelope phase. Chemical transformations in bulk ice lower D/H ratios of icy species and do not help explaining the super-deuteration. In the protostellar phase, the D2O/HDO abundance ratio was calculated to be higher than the HDO/H2O ratio owing to gas-phase chemistry. Species that undergo evaporation from ices have a high molecular D/H ratio and a high gas-phase abundance.

  13. CORRELATING INFALL WITH DEUTERIUM FRACTIONATION IN DENSE CORES

    SciTech Connect

    Schnee, Scott; Brunetti, Nathan; Friesen, Rachel; Di Francesco, James; Johnstone, Doug; Pon, Andy; Caselli, Paola

    2013-11-10

    We present a survey of HCO{sup +} (3-2) observations pointed toward dense cores with previous measurements of N(N{sub 2}D{sup +})/N(N{sub 2}H{sup +}). Of the 26 cores in this survey, 5 show the spectroscopic signature of outward motion, 9 exhibit neither inward nor outward motion, 11 appear to be infalling, and 1 is not detected. We compare the degree of deuterium fractionation with infall velocities calculated from the HCO{sup +} spectra and find that those cores with [D]/[H] > 0.1 are more likely to have the signature of inward motions than cores with smaller [D]/[H] ratios. Infall motions are also much more common in cores with masses exceeding their thermal Jeans masses. The fastest infall velocity measured belongs to one of the two protostellar cores in our survey, L1521F, and the observed motions are typically on the order of the sound speed.

  14. Deuterium fractionation and H2D+ evolution in turbulent and magnetized cloud cores

    NASA Astrophysics Data System (ADS)

    Körtgen, Bastian; Bovino, Stefano; Schleicher, Dominik R. G.; Giannetti, Andrea; Banerjee, Robi

    2017-08-01

    High-mass stars are expected to form from dense prestellar cores. Their precise formation conditions are widely discussed, including their virial condition, which results in slow collapse for supervirial cores with strong support by turbulence or magnetic fields, or fast collapse for subvirial sources. To disentangle their formation processes, measurements of the deuterium fractions are frequently employed to approximately estimate the ages of these cores and to obtain constraints on their dynamical evolution. We here present 3D magnetohydrodynamical simulations including for the first time an accurate non-equilibrium chemical network with 21 gas-phase species plus dust grains and 213 reactions. With this network we model the deuteration process in fully depleted prestellar cores in great detail and determine its response to variations in the initial conditions. We explore the dependence on the initial gas column density, the turbulent Mach number, the mass-to-magnetic flux ratio and the distribution of the magnetic field, as well as the initial ortho-to-para ratio (OPR) of H2. We find qualitatively good agreement with recent observations of deuterium fractions in quiescent sources. Our results show that deuteration is rather efficient, even when assuming a conservative OPR of 3 and highly subvirial initial conditions, leading to large deuterium fractions already within roughly a free-fall time. We discuss the implications of our results and give an outlook to relevant future investigations.

  15. Deuterium Fractionation in Analogs of Interstellar Ices: Laboratory Measurements

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    A question of key interest in the field of Astrobiology is the extent to which organic compounds made in space may play a role in the origin of life in planetary systems. In general, the best proof that at least some interstellar materials survive incorporation into forming stellar/planetary systems is their identification in extraterrestrial samples through detection of the isotopic anomalies they may carry. In the case of organic compounds, the chief isotopic anomalies that might be expected are the enrichment of D and 15N. and such enrichments are seen in primitive extraterrestrial materials, for example, in the organics in carbonaceous chondrites and interplanetary dust particles. In my talk I will review the various astrochemical processes by which deuterium can become enriched in organic compounds and will discuss some recent laboratory experiments that examine one of these processes in particular. name]y the UV photolysis of interstellar ices. Finally, I will review the current state of our knowledge of D enrichments in primitive solar system materials and discuss the constraints these data place on the relative importance of the various possible interstellar D enrichment processes.

  16. Fractionation of hydrogen and deuterium on Venus due to collisional ejection

    NASA Technical Reports Server (NTRS)

    Gurwell, Mark A.; Yung, Yuk L.

    1993-01-01

    The collisional ejection process for hydrogen on Venus is reanalyzed. Improved values for the efficiency of H and D escape as a function of the ionospheric temperature are reported. It is proposed that the reduction of the hydrogen flux for collisional ejection be reduced from 8 to 3.5 x 10 exp 6/sq cm/s, and a revised D/H fractional factor of 0.47 due to collisional ejection is suggested. The resulting deuterium flux is 3.1 x 10 exp 4/sq cm/s, roughly six times the flux due to charge exchange, making collisional ejection the dominant escape mechanism for deuterium on Venus.

  17. Fractionation of hydrogen and deuterium on Venus due to collisional ejection

    NASA Astrophysics Data System (ADS)

    Gurwell, M. A.; Yung, Y. L.

    1993-02-01

    The collisional ejection process for hydrogen on Venus is reanalyzed. Improved values for the efficiency of H and D escape as a function of the ionospheric temperature are reported. It is proposed that the reduction of the hydrogen flux for collisional ejection be reduced from 8 to 3.5 x 10 exp 6/sq cm/s, and a revised D/H fractional factor of 0.47 due to collisional ejection is suggested. The resulting deuterium flux is 3.1 x 10 exp 4/sq cm/s, roughly six times the flux due to charge exchange, making collisional ejection the dominant escape mechanism for deuterium on Venus.

  18. Deuterium Fractionation and Ionization Degree in Massive Protostellar/cluster Cores

    NASA Astrophysics Data System (ADS)

    Chen, Huei-Ru; Liu, Sheng-Yuan; Su, Yu-Nung

    2013-03-01

    We have conducted a survey of deuterium fractionation of N2H+, RD (N2H+) ≡ N(N2D+)/N(N2H+), with the Arizona Radio Observatory (ARO) Submillimeter Telescope (SMT) to assess the use of RD (N2H+) as an evolutionary tracer among massive protostellar/cluster cores in early stages. Our sample includes 32 dense cores in various evolutionary stages, from high-mass starless cores (HMSCs), high-mass protostellar objects (HMPOs), to ultra-compact (UC) HII regions, in infrared dark clouds (IRDCs) and high infrared extinction clouds. The results show a decreasing trend in deuterium fractionation with evolutionary stage traced by gas temperature and line width (Fig. 1). A moderate increasing trend of deuterium fractionation with the CO depletion factor is also found among cores in IRDCs and HMSCs. These suggest a general chemical behavior of deuterated species in low- and high-mass protostellar candidates. Upper limits to the ionization degree are also estimated to be in the range of 4 × 10-8 - 5 × 10-6.

  19. NEW EXTENDED DEUTERIUM FRACTIONATION MODEL: ASSESSMENT AT DENSE ISM CONDITIONS AND SENSITIVITY ANALYSIS

    SciTech Connect

    Albertsson, T.; Semenov, D. A.; Henning, Th.; Vasyunin, A. I.; Herbst, E.

    2013-08-15

    Observations of deuterated species are useful in probing the temperature, ionization level, evolutionary stage, chemistry, and thermal history of astrophysical environments. The analysis of data from the Atacama Large Millimeter Array and other new telescopes requires an elaborate model of deuterium fractionation. This paper presents a publicly available chemical network with multi-deuterated species and an extended, up-to-date set of gas-phase and surface reactions. To test this network, we simulate deuterium fractionation in diverse interstellar sources. Two cases of initial abundances are considered: (1) atomic except for H{sub 2} and HD, and (2) molecular from a prestellar core. We reproduce the observed D/H ratios of many deuterated molecules, and sort the species according to their sensitivity to temperature gradients and initial abundances. We find that many multiply deuterated species produced at 10 K retain enhanced D/H ratios at temperatures {approx}< 100 K. We study how recent updates to reaction rates affect calculated D/H ratios, and perform a detailed sensitivity analysis of the uncertainties of the gas-phase reaction rates in the network. We find that uncertainties are generally lower in dark cloud environments than in warm infrared dark clouds and that uncertainties increase with the size of the molecule and number of D-atoms. A set of the most problematic reactions is presented. We list potentially observable deuterated species predicted to be abundant in low- and high-mass star-formation regions.

  20. Hydrated fractions of cellulosics probed by infrared spectroscopy coupled with dynamics of deuterium exchange.

    PubMed

    Driemeier, Carlos; Mendes, Fernanda M; Ling, Liu Yi

    2015-08-20

    This article presents a novel method to selectively probe the non-crystalline, hydrated fractions of cellulosic biomass. The method is based on time-resolved infrared spectra analyzed to provide information on spectral and dynamical features of deuterium exchange (OH → OD) in D2O atmosphere. We assign deuterium exchange spectral regions (700-3800 cm(-1)) and explore changes due to relative humidity, different cellulosic samples, and infrared polarization. Here, two results are highlighted. First, a wide range of celluloses isolated from plants show remarkable spectral similarities whatever the relative amounts of cellulose and xylan. This result supports an inherent type of hydrated disorder which is mostly insensitive to the molecular identities of the associated polysaccharides. Second, polarized infrared analysis of cotton reveals hydrated cellulose having chains preferentially aligned with those of crystals, while the hydroxyls of hydrated cellulose present much more randomized orientation. Our results provide new insights on molecular and group orientation and on hydrogen bonding in hydrated fractions of cellulosic biomass.

  1. Structure, Dynamics, and Deuterium Fractionation of Massive Pre-stellar Cores

    NASA Astrophysics Data System (ADS)

    Goodson, Matthew D.; Kong, Shuo; Tan, Jonathan C.; Heitsch, Fabian; Caselli, Paola

    2016-12-01

    High levels of deuterium fraction in N2H+ are observed in some pre-stellar cores. Single-zone chemical models find that the timescale required to reach observed values ({D}{frac}{{{N}}2{{{H}}}+}\\equiv {{{N}}}2{{{D}}}+/{{{N}}}2{{{H}}}+≳ 0.1) is longer than the free-fall time, possibly 10 times longer. Here, we explore the deuteration of turbulent, magnetized cores with 3D magnetohydrodynamics simulations. We use an approximate chemical model to follow the growth in abundances of N2H+ and N2D+. We then examine the dynamics of the core using each tracer for comparison to observations. We find that the velocity dispersion of the core as traced by N2D+ appears slightly sub-virial compared to predictions of the Turbulent Core Model of McKee & Tan, except at late times just before the onset of protostar formation. By varying the initial mass surface density, the magnetic energy, the chemical age, and the ortho-to-para ratio of H2, we also determine the physical and temporal properties required for high deuteration. We find that low initial ortho-to-para ratios (≲ 0.01) and/or multiple free-fall times (≳ 3) of prior chemical evolution are necessary to reach the observed values of deuterium fraction in pre-stellar cores.

  2. Effect of different tritium fractions on some plasma parameters in deuterium-tritium magnetic confinement fusion

    NASA Astrophysics Data System (ADS)

    Motevalli, S. M.; Mohsenpour, T.; Dashtban, N.

    2016-09-01

    Nearly all reactor projects have considered deuterium-tritium (D-T) fusion. The cross section of D-T reaction is larger than those of other fusion reactions, thus it is considered to be a more favorable reaction. The mix of fuel can vary. In this work, a comparison between the effects of different mixture of D-T fuel on the plasma parameters is made. A time dependence calculation of the fusion process is performed using the zero-dimensional model based on a coupled set of particle and energy balance equations in ITER (International Thermonuclear Experimental Reactor). The time evolution of plasma parameters is also analyzed numerically.

  3. Dependence of implantation temperature on chemical behavior of energetic deuterium implanted into tungsten carbide

    NASA Astrophysics Data System (ADS)

    Igarashi, E.; Nishikawa, Y.; Nakahata, T.; Yoshikawa, A.; Oyaidzu, M.; Oya, Y.; Okuno, K.

    2007-06-01

    Dependence of implantation temperature on chemical behavior of energetic deuterium implanted into WC was investigated by TDS and XPS. 1.0 keV D2+ ions were implanted into WC samples at the implantation temperature range of 323-873 K. It was found that the deuterium retention decreased as the implantation temperature increased. Above 573 K, most of the retained deuterium was bound to C, which was less than 20% of the total D retention after D2+ implantation at 323 K. Above 673 K, C was segregated on the WC surface and some of the implanted deuterium was retained in the segregated carbon layer. Additionally, it can be said that the D retention in WC was much less than that in other carbon-related materials, such as graphite and SiC. Hydrogen isotope retention can be reduced significantly when WC is formed on a divertor surface as a redeposited layer.

  4. Deuterium Fractionation as an Evolutionary Probe in Massive Protostellar/Cluster Cores

    NASA Astrophysics Data System (ADS)

    Chen, Huei-Ru; Liu, Sheng-Yuan; Su, Yu-Nung; Wang, Mei-Yan

    2011-12-01

    Clouds of high infrared extinction are promising sites of massive star/cluster formation. A large number of cloud cores discovered in recent years allow for the investigation of a possible evolutionary sequence among cores in early phases. We have conducted a survey of deuterium fractionation toward 15 dense cores in various evolutionary stages, from high-mass starless cores to ultracompact H II regions, in the massive star-forming clouds of high extinction, G34.43+0.24, IRAS 18151-1208, and IRAS 18223-1243, with the Submillimeter Telescope. Spectra of N2H+ (3-2), N2D+ (3-2), and C18O (2-1) were observed to derive the deuterium fractionation of N2H+, D frac ≡ N(N2D+)/N(N2H+), as well as the CO depletion factor for every selected core. Our results show a decreasing trend in D frac with both gas temperature and line width. Since colder and quiescent gas is likely to be associated with less evolved cores, larger D frac appears to correlate with early phases of core evolution. Such decreasing trend resembles the behavior of D frac in the low-mass protostellar cores and is consistent with several earlier studies in high-mass protostellar cores. We also find a moderate increasing trend of D frac with the CO depletion factor, suggesting that sublimation of ice mantles alters the competition in the chemical reactions and reduces D frac. Our findings suggest a general chemical behavior of deuterated species in both low- and high-mass protostellar candidates at early stages. In addition, upper limits to the ionization degree are estimated to be within 2 × 10-7 and 5 × 10-6. The four quiescent cores have marginal field-neutral coupling and perhaps favor turbulent cooling flows.

  5. Deuterium Fractionation in Massive Clumps in Early Evolutionary Stages of High-Mass Star Formation

    NASA Astrophysics Data System (ADS)

    Sakai, T.; Sakai, N.; Furuya, K.; Aikawa, Y.; Hirota, T.; Yamamoto, S.

    2011-05-01

    To understand the initial conditions of star formation, it is useful to observe deuterated species, because the deuterium fractionation can be enhanced in cold starless phase. We have observed the HN13C J=1--0 and DNC J=1--0 lines toward 18 massive clumps, including infrared dark clouds (IRDCs) and high-mass protostellar objects (HMPOs), by using the Nobeyama Radio Observatory 45 m telescope. We have found that the HN13C emission is stronger than the DNC emission toward all the observed sources. The averaged DNC/HNC ratio of the observed sources is found to be 0.007, which is lower than that of the low-mass cores. The DNC/HNC ratio is found to be roughly anti-correlated with the kinetic temperature derived from NH_3 (J, K) = (1, 1) and (2, 2). We have also found that the DNC/HNC ratio of some IRDCs is lower than that of HMPOs, although the kinetic temperature of the IRDCs is lower than that of the HMPOs. With the aid of chemical model simulations, we discuss how the deuterium fractionation decreases after the onset of star formation. We suggest that the DNC/HNC ratio of star forming cores may reflect the timescale of starless phase. In addition to the above results, we report the current status of some instruments, which we have developed for observations of deuterated species. We have developed the 70 GHz receiver for the Nobeyama Radio Observatory (NRO) 45 m telescope. By using this receiver, we can observe the J=1-0 lines of various fundamental deuterated species such as DCN, DCO^+, and C_2D. For observations of the H_2D^+ line at 372 GHz, we have improved the 350 GHz receiver for the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope. We will also report the observation plans of deuterated species with these receivers.

  6. Origin of Terrestrial Water: Hydrogen/Deuterium Fractionation into Earth's Core

    NASA Astrophysics Data System (ADS)

    Wu, J.; Buseck, P. R.

    2014-12-01

    Hydrogen isotopic compositions are among the most important constraints on the origin of Earth's water. Earth's bulk water content, which is small but not negligible, is significantly greater than what the thermal gradient of the solar nebula disk would suggest for planetesimal materials condensed at one astronomical unit. The proto-solar nebula is a likely source of early Earth's water, with probable contributions from one or more of the following: water-rich planetesimals, ordinary and carbonaceous meteorites, comets, asteroids, and interplanetary dust particles. However, all of these sources have been questioned, and the proposed proto-solar nebular origin has been disputed in light of the large difference in hydrogen isotopic composition between it and terrestrial water. Current opposition to the solar nebular hypothesis is based on the critical assumption that no processes in the interior of the early Earth changed the isotopic composition of hydrogen. Nevertheless, a hypothesized hydrogenation reaction of liquid iron (2Fe + xH2 ↔ 2FeHx) during core formation likely provided a fractionation mechanism between hydrogen and deuterium (D). We propose that modern D/H ratios at Earth's surface resulted from this isotopic fractionation and that terrestrial water originated from oxidation of proto-solar hydrogen dissolved in the magma ocean in the early Earth by coexisting oxides (such as FeO). Thus, the isotopic composition of water on Earth can be mainly explained by internal terrestrial processes.

  7. Deuterium Fractionation during Amino Acid Formation by Photolysis of Interstellar Ice Analogs Containing Deuterated Methanol

    NASA Astrophysics Data System (ADS)

    Oba, Yasuhiro; Takano, Yoshinori; Watanabe, Naoki; Kouchi, Akira

    2016-08-01

    Deuterium (D) atoms in interstellar deuterated methanol might be distributed into complex organic molecules through molecular evolution by photochemical reactions in interstellar grains. In this study, we use a state-of-the-art high-resolution mass spectrometer coupled with a high-performance liquid chromatography system to quantitatively analyze amino acids and their deuterated isotopologues formed by the photolysis of interstellar ice analogs containing singly deuterated methanol CH2DOH at 10 K. Five amino acids (glycine, α-alanine, β-alanine, sarcosine, and serine) and their deuterated isotopologues whose D atoms are bound to carbon atoms are detected in organic residues formed by photolysis followed by warming up to room temperature. The abundances of singly deuterated amino acids are in the range of 0.3-1.1 relative to each nondeuterated counterpart, and the relative abundances of doubly and triply deuterated species decrease with an increasing number of D atoms in a molecule. The abundances of amino acids increase by a factor of more than five upon the hydrolysis of the organic residues, leading to decreases in the relative abundances of deuterated species for α-alanine and β-alanine. On the other hand, the relative abundances of the deuterated isotopologues of the other three amino acids did not decrease upon hydrolysis, indicating different formation mechanisms of these two groups upon hydrolysis. The present study facilitates both qualitative and quantitative evaluations of D fractionation during molecular evolution in the interstellar medium.

  8. Water deuterium fractionation in the low-mass protostar NGC1333-IRAS2A

    NASA Astrophysics Data System (ADS)

    Liu, F.-C.; Parise, B.; Kristensen, L.; Visser, R.; van Dishoeck, E. F.; Güsten, R.

    2011-03-01

    Context. Although deuterium enrichment of water may provide an essential piece of information in the understanding of the formation of comets and protoplanetary systems, only a few studies up to now have aimed at deriving the HDO/H2O ratio in low-mass star forming regions. Previous studies of the molecular deuteration toward the solar-type class 0 protostar, IRAS 16293-2422, have shown that the D/H ratio of water is significantly lower than other grain-surface-formed molecules. It is not clear if this property is general or particular to this source. Aims: In order to see if the results toward IRAS 16293-2422 are particular, we aimed at studying water deuterium fractionation in a second low-mass solar-type protostar, NGC1333-IRAS2A. Methods: Using the 1-D radiative transfer code RATRAN, we analyzed five HDO transitions observed with the IRAM 30 m, JCMT, and APEX telescopes. We assumed that the abundance profile of HDO in the envelope is a step function, with two different values in the inner warm (T > 100 K) and outer cold (T < 100 K) regions of the protostellar envelope. Results: The inner and outer abundance of HDO is found to be well constrained at the 3σ level. The obtained HDO inner and outer fractional abundances are xHDO_in = 6.6 × 10-8-1.0 × 10-7(3σ) and x^{HDO}out=9×10-11= 9 × 10-11-1.0-1.8 × 10-9(3σ). These values are close to those in IRAS 16293-2422, which suggests that HDO may be formed by the same mechanisms in these two solar-type protostars. Taking into account the (rather poorly onstrained) H2O abundance profile deduced from Herschel observations, the derived HDO/H2O in the inner envelope is ≥1% and in the outer envelope it is 0.9%-18%. These values are more than one order of magnitude higher than what is measured in comets. If the same ratios apply to the protosolar nebula, this would imply that there is some efficient reprocessing of the material between the protostellar and cometary phases. Conclusions: The H2O inner fractional

  9. Measurements of Deuterium-Tritium Fuel Fractionation from Kinetic Effects in Ignition-Relevant Direct-Drive Cryogenic Implosions

    NASA Astrophysics Data System (ADS)

    Forrest, C.; Glebov, V. Yu.; Knauer, J. P.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.

    2016-10-01

    Measurements of DT and DD reaction yields have been studied using ignition-relevant, cryogenically cooled deuterium-tritium gas-filled cryogenic DT targets in inertial confinement fusion (ICF) implosions. In these experiments, carried out at the Omega Laser Facility, highresolution time-of-flight spectroscopy was used to measure the primary neutron peak distribution required to infer the DT and DD reaction yields. From these measurements, it will be shown that the yield ratio has a χ2/per degree of freedom of 0.67 as compared with the measured fraction of the target fuel composition. This observation indicates that kinetic effects leading to species separation are insignificant in ICF ignition-relevant DT implosions on OMEGA. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  10. DEUTERIUM FRACTIONATION AS AN EVOLUTIONARY PROBE IN THE INFRARED DARK CLOUD G28.34+0.06

    SciTech Connect

    Chen, H.-R.; Liu, S.-Y.; Su, Y.-N.; Zhang Qizhou

    2010-04-10

    We have observed the J = 3 - 2 transition of N{sub 2}H{sup +} and N{sub 2}D{sup +} to investigate the trend of deuterium fractionation with evolutionary stage in three selected regions in the infrared dark cloud (IRDC) G28.34+0.06 with the Submillimeter Telescope and the Submillimeter Array. A comprehensible enhancement of roughly 3 orders of magnitude in deuterium fractionation over the local interstellar D/H ratio is observed in all sources. In particular, our sample of massive star-forming cores in G28.34+0.06 shows a moderate decreasing trend over a factor of 3 in the N(N{sub 2}D{sup +})/N(N{sub 2}H{sup +}) ratio with evolutionary stage, a behavior resembling that previously found in low-mass protostellar cores. This suggests a possible extension for the use of the N(N{sub 2}D{sup +})/N(N{sub 2}H{sup +}) ratio as an evolutionary tracer to high-mass protostellar candidates. In the most evolved core, MM1, the N{sub 2}H{sup +}(3-2) emission appears to avoid the warm region traced by dust continuum emission and emission of {sup 13}CO sublimated from grain mantles, indicating an instant release of gas-phase CO. The majority of the N{sub 2}H{sup +} and N{sub 2}D{sup +} emission is associated with extended structures larger than 8'' ({approx}0.2 pc)

  11. Platform Dependencies in Bottom-up Hydrogen/Deuterium Exchange Mass Spectrometry*

    PubMed Central

    Burns, Kyle M.; Rey, Martial; Baker, Charles A. H.; Schriemer, David C.

    2013-01-01

    Hydrogen-deuterium exchange mass spectrometry is an important method for protein structure-function analysis. The bottom-up approach uses protein digestion to localize deuteration to higher resolution, and the essential measurement involves centroid mass determinations on a very large set of peptides. In the course of evaluating systems for various projects, we established two (HDX-MS) platforms that consisted of a FT-MS and a high-resolution QTOF mass spectrometer, each with matched front-end fluidic systems. Digests of proteins spanning a 20–110 kDa range were deuterated to equilibrium, and figures-of-merit for a typical bottom-up (HDX-MS) experiment were compared for each platform. The Orbitrap Velos identified 64% more peptides than the 5600 QTOF, with a 42% overlap between the two systems, independent of protein size. Precision in deuterium measurements using the Orbitrap marginally exceeded that of the QTOF, depending on the Orbitrap resolution setting. However, the unique nature of FT-MS data generates situations where deuteration measurements can be inaccurate, because of destructive interference arising from mismatches in elemental mass defects. This is shown through the analysis of the peptides common to both platforms, where deuteration values can be as low as 35% of the expected values, depending on FT-MS resolution, peptide length and charge state. These findings are supported by simulations of Orbitrap transients, and highlight that caution should be exercised in deriving centroid mass values from FT transients that do not support baseline separation of the full isotopic composition. PMID:23197788

  12. Deuterium fractionation in the presolar nebula - Kinetic limitations on surface catalysis

    NASA Technical Reports Server (NTRS)

    Grinspoon, David H.; Lewis, John S.

    1987-01-01

    A quantitative test is presented for the possibility that grain-based catalysis could shorten the equilibration times of low temperature equilibrium fractionation sufficiently to account for the D/H ratio values of the solar system even at nebular temperatures. It is found that under the highly idealized conditions in which the full cosmic abundance of Ni is available for catalysis in pure, 5-micron grains, the equilibration time constant becomes greater than the nebular lifetime at temperatures below 560 K. This lower limit is not, however, sufficiently low to permit strong fractionation.

  13. Deuterium fractionation in the presolar nebula - Kinetic limitations on surface catalysis

    NASA Technical Reports Server (NTRS)

    Grinspoon, David H.; Lewis, John S.

    1987-01-01

    A quantitative test is presented for the possibility that grain-based catalysis could shorten the equilibration times of low temperature equilibrium fractionation sufficiently to account for the D/H ratio values of the solar system even at nebular temperatures. It is found that under the highly idealized conditions in which the full cosmic abundance of Ni is available for catalysis in pure, 5-micron grains, the equilibration time constant becomes greater than the nebular lifetime at temperatures below 560 K. This lower limit is not, however, sufficiently low to permit strong fractionation.

  14. The temperature and ion energy dependence of deuterium retention in lithium films

    NASA Astrophysics Data System (ADS)

    Buzi, Luxherta; Koel, Bruce E.; Skinner, Charles H.

    2016-10-01

    Lithium conditioning of plasma facing components in magnetic fusion devices has improved plasma performance and lowered hydrogen recycling. For applications of lithium in future high heat flux and long pulse duration machines it is important to understand and parameterize deuterium retention in lithium. This work presents surface science studies of deuterium retention in lithium films as a function of surface temperature, incident deuterium ion energy and flux. Initial experiments are performed on thin (3-30 ML) lithium films deposited on a single crystal molybdenum substrate to avoid effects due to grain boundaries, intrinsic defects and impurities. A monoenergetic and mass-filtered deuterium ion beam was generated in a differentially pumped Colutron ion gun. Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to identify the elemental composition and temperature programmed desorption was used to measure the deuterium retention under the different conditions. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  15. Cometary deuterium.

    PubMed

    Meier, R; Owen, T C

    1999-01-01

    Deuterium fractionations in cometary ices provide important clues to the origin and evolution of comets. Mass spectrometers aboard spaceprobe Giotto revealed the first accurate D/H ratios in the water of Comet 1P/Halley. Ground-based observations of HDO in Comets C/1996 B2 (Hyakutake) and C/1995 O1 (Hale-Bopp), the detection of DCN in Comet Hale-Bopp, and upper limits for several other D-bearing molecules complement our limited sample of D/H measurements. On the basis of this data set all Oort cloud comets seem to exhibit a similar (D/H)H2O ratio in H2O, enriched by about a factor of two relative to terrestrial water and approximately one order of magnitude relative to the protosolar value. Oort cloud comets, and by inference also classical short-period comets derived from the Kuiper Belt cannot be the only source for the Earth's oceans. The cometary O/C ratio and dynamical reasons make it difficult to defend an early influx of icy planetesimals from the Jupiter zone to the early Earth. D/H measurements of OH groups in phyllosilicate rich meteorites suggest a mixture of cometary water and water adsorbed from the nebula by the rocky grains that formed the bulk of the Earth may be responsible for the terrestrial D/H. The D/H ratio in cometary HCN is 7 times higher than the value in cometary H2O. Species-dependent D-fractionations occur at low temperatures and low gas densities via ion-molecule or grain-surface reactions and cannot be explained by a pure solar nebula chemistry. It is plausible that cometary volatiles preserved the interstellar D fractionation. The observed D abundances set a lower limit to the formation temperature of (30 +/- 10) K. Similar numbers can he derived from the ortho-to-para ratio in cometary water, from the absence of neon in cometary ices and the presence of S2. Noble gases on Earth and Mars, and the relative abundance of cometary hydrocarbons place the comet formation temperature near 50 K. So far all cometary D/H measurements refer to

  16. Discovery of temperature-dependent phenomena of muon-catalyzed fusion in solid deuterium and tritium mixtures.

    PubMed

    Kawamura, N; Nagamine, K; Matsuzaki, T; Ishida, K; Nakamura, S N; Matsuda, Y; Tanase, M; Kato, M; Sugai, H; Kudo, K; Takeda, N; Eaton, G H

    2003-01-31

    A systematic experimental study on muon-catalyzed fusion was conducted using a series of solid deuterium and tritium mixtures. A variety of conditions were investigated, i.e., tritium concentrations from 20% to 70%, and temperatures from 5 to 16 K. With decreasing temperature, we observed an unexpected decrease in the muon cycling rate (lambda(c)) and an increase in the muon loss probability (W). The origins of these observed changes were interpreted by the temperature-dependence in the dt mu formation process for lambda(c) and that in the muon reactivation process after muon-to-alpha sticking for W.

  17. THE DEUTERIUM-BURNING MASS LIMIT FOR BROWN DWARFS AND GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Burrows, Adam; Milsom, John A. E-mail: burrows@astro.princeton.edu

    2011-01-20

    There is no universally acknowledged criterion to distinguish brown dwarfs from planets. Numerous studies have used or suggested a definition based on an object's mass, taking the {approx}13 Jupiter mass (M{sub J} ) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 M{sub J} is generally a reasonable rule of thumb, the deuterium fusion mass depends on the helium abundance, the initial deuterium abundance, the metallicity of the model, and on what fraction of an object's initial deuterium abundance must combust in order for the object to qualify as having burned deuterium. Even though, for most proto-brown dwarf conditions, 50% of the initial deuterium will burn if the object's mass is {approx}(13.0 {+-} 0.8) M{sub J} , the full range of possibilities is significantly broader. For models ranging from zero-metallicity to more than three times solar metallicity, the deuterium-burning mass ranges from {approx}11.0 M{sub J} (for three times solar metallicity, 10% of initial deuterium burned) to {approx}16.3 M{sub J} ( for zero metallicity, 90% of initial deuterium burned).

  18. The Mass-Dependence of Cadmium Isotope Fractionation During Evaporation

    NASA Astrophysics Data System (ADS)

    Rehkamper, M.; Wombacher, F.; Mezger, K.; Wiechert, U.

    2002-12-01

    Isotope fractionation laws relate the isotope fractionation factor αA of one isotope ratio to the fractionation factor αB of a second isotope ratio of the same element with a fractionation exponent β, such that αA = αBβ. In a recent paper, Young et al. (GCA 66, 1095-1104 (2002)) inferred that kinetic and equilibrium isotope fractionations are characterized by different mass functions, such that βkin is not equal to βeq. As a consequence, kinetic isotope fractionation is expected to produce fractionation lines in three isotope space that are different from those generated by equilibrium fractionation processes. Young et al. furthermore stated that the variability in mass-dependent fractionation laws may be sufficient to account for the negative Δ17O of tropospheric O2 and the Δ17O anomalies of minerals in SNC meteorites. Such variations have otherwise been interpreted as evidence of non-mass dependant isotope fractionations (Luz et al., Nature 400, 547-550 (1999); Farquhar et al., Science 280, 1589-1582 (1998)). In the present study, we investigated the mass-dependence of isotope fractionation by evaluating the results of evaporation experiments that produced very large differences in Cd isotope compositions (up to about 100‰ ). In these experiments, liquid Cd was evaporated into a vacuum at a temperature of about 200°C. The metal residues remaining after evaporation were analyzed for their Cd isotope composition by multiple-collector inductively coupled plasma-mass spectrometry (MC-ICPMS) relative to the unfractionated starting material. The precision of the measurements is sufficient to clearly distinguish between different fractionation mechanisms. In linearized three-isotope space, the residual Cd metals plot on fractionation lines (e.g., with a slope β = 2.049 +/- 2 for 106}Cd/{114Cd vs. 110}Cd/{114Cd) that are intermediate between the kinetic (β = 2.036) and the equilibrium (β = 2.075) fractionation lines. This can be explained by an

  19. Alpha-tocopherol disappearance rates from plasma depend on lipid concentrations: Studies using deuterium labeled collard greens in younger and older adults

    USDA-ARS?s Scientific Manuscript database

    Little is known about alpha-tocopherol's bioavailability as a constituent of food or its dependence on a subject's age. To evaluate the alpha-tocopherol bioavailability from food, we used collard greens grown in deuterated water (2H collard greens) as a source of deuterium-labeled (2H) alpha-tocophe...

  20. Structure-dependent degradation of polar compounds in weathered oils observed by atmospheric pressure photo-ionization hydrogen/deuterium exchange ultrahigh resolution mass spectrometry.

    PubMed

    Islam, Ananna; Kim, Donghwi; Yim, Un Hyuk; Shim, Won Joon; Kim, Sunghwan

    2015-10-15

    The resin fractions of fresh mixtures of three oils spilled during the M/V Hebei Spirit oil spill, as well as weathered oils collected at weathering stages II and IV from the oil spill site were analyzed and compared by atmospheric pressure photo-ionization hydrogen/deuterium exchange mass spectrometry (HDX MS). The significantly decreased abundance of N(+) and [N-H+D](+) ions suggested that secondary and tertiary amine-containing compounds were preferentially degraded during the early stage of weathering. [N+H](+) and [N+D](+) ions previously attributed to pyridine-type compounds degraded more slowly than secondary and tertiary amine-containing compounds. The preferential degradation of nitrogen-containing compounds was confirmed by photo-degradation experiments using 15 standard compounds. In addition, significant increases of [S1O1+H](+) and [S1O1+D](+) ions with higher DBE values were observed from fresh oil mixtures as compared to stages II and IV samples, and that could be linked with the decrease of higher DBE compounds of the S1 class. This study presented convincing arguments and evidence demonstrating that secondary and tertiary amines were more vulnerable to photo-degradation than compounds containing pyridine, and hence, preferential degradation depending on chemical structures must be considered in the production of hazardous or toxic components. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Common magnitude representation of fractions and decimals is task dependent.

    PubMed

    Zhang, Li; Fang, Qiaochu; Gabriel, Florence C; Szűcs, Denes

    2016-01-01

    Although several studies have compared the representation of fractions and decimals, no study has investigated whether fractions and decimals, as two types of rational numbers, share a common representation of magnitude. The current study aimed to answer the question of whether fractions and decimals share a common representation of magnitude and whether the answer is influenced by task paradigms. We included two different number pairs, which were presented sequentially: fraction-decimal mixed pairs and decimal-fraction mixed pairs in all four experiments. Results showed that when the mixed pairs were very close numerically with the distance 0.1 or 0.3, there was a significant distance effect in the comparison task but not in the matching task. However, when the mixed pairs were further apart numerically with the distance 0.3 or 1.3, the distance effect appeared in the matching task regardless of the specific stimuli. We conclude that magnitudes of fractions and decimals can be represented in a common manner, but how they are represented is dependent on the given task. Fractions and decimals could be translated into a common representation of magnitude in the numerical comparison task. In the numerical matching task, fractions and decimals also shared a common representation. However, both of them were represented coarsely, leading to a weak distance effect. Specifically, fractions and decimals produced a significant distance effect only when the numerical distance was larger.

  2. Coherent states and their time dependence in fractional dimensions

    NASA Astrophysics Data System (ADS)

    Thilagam, A.; Lohe, M. A.

    2007-08-01

    We construct representations of the Lie algebra \\mathfrak{su}(1,1) using representations of the momentum and position operators satisfying the R-deformed Heisenberg relations, in which the fractional dimension d and angular momentum ell appear as parameters. The Bargmann index κ, which characterizes representations of the positive discrete series of \\mathfrak{su}(1,1) , can take any positive value. We construct coherent states in fractional dimensions, in particular we extend the two well-known analytic representations of coherent states for \\mathfrak{su}(1,1) , Perelomov and Barut-Girardello states, from dimension one to any dimension d. We generalize this construction to time-dependent coherent states by means of the \\mathfrak{su}(1,1) symmetries of the quantum time-dependent harmonic oscillator in fractional dimensions. We investigate the uncertainty relations of the momentum and position operators with respect to these coherent states, and their dependence on the dimension.

  3. Hydrogen–Deuterium Exchange and Mass Spectrometry Reveal the pH-Dependent Conformational Changes of Diphtheria Toxin T Domain

    PubMed Central

    2015-01-01

    The translocation (T) domain of diphtheria toxin plays a critical role in moving the catalytic domain across the endosomal membrane. Translocation/insertion is triggered by a decrease in pH in the endosome where conformational changes of T domain occur through several kinetic intermediates to yield a final trans-membrane form. High-resolution structural studies are only applicable to the static T-domain structure at physiological pH, and studies of the T-domain translocation pathway are hindered by the simultaneous presence of multiple conformations. Here, we report the application of hydrogen–deuterium exchange mass spectrometry (HDX-MS) for the study of the pH-dependent conformational changes of the T domain in solution. Effects of pH on intrinsic HDX rates were deconvolved by converting the on-exchange times at low pH into times under our “standard condition” (pH 7.5). pH-Dependent HDX kinetic analysis of T domain clearly reveals the conformational transition from the native state (W-state) to a membrane-competent state (W+-state). The initial transition occurs at pH 6 and includes the destabilization of N-terminal helices accompanied by the separation between N- and C-terminal segments. The structural rearrangements accompanying the formation of the membrane-competent state expose a hydrophobic hairpin (TH8–9) to solvent, prepare it to insert into the membrane. At pH 5.5, the transition is complete, and the protein further unfolds, resulting in the exposure of its C-terminal hydrophobic TH8–9, leading to subsequent aggregation in the absence of membranes. This solution-based study complements high resolution crystal structures and provides a detailed understanding of the pH-dependent structural rearrangement and acid-induced oligomerization of T domain. PMID:25290210

  4. 740,000-year Deuterium Record in an Ice Core from Dome C, Antarctica

    DOE Data Explorer

    Jouzel, Jean [Laboratoire des Sciences du Climat et de l'Environnement

    2004-01-01

    Because isotopic fractions of the heavier oxygen-18 (18O) and deuterium (2H) in snowfall are temperature-dependent and a strong spatial correlation exists between the annual mean temperature and the mean isotopic fraction of 18O or 2H in precipitation, it is possible to derive temperature records from the records of those isotopes in ice cores.

  5. Velocity-dependent isotope fractionation in secondary-ion emission

    SciTech Connect

    Gnaser, H.; Hutcheon, I.D.

    1987-01-15

    The formation of secondary ions is subject to isotopic fractionation (differing ionization probabilities for two isotopes) that depends linearly on the inverse velocity of the ejected ions. Theoretically, such a correlation follows directly from an exponential dependence of the ionization probability P on v/sup -1/, Pproportionalexp(-v/sub 0//v). The parameter v/sub 0/, derived from the experiment, amounts to --2 x 10/sup 6/ cm/sec for B, Si, and Ca ions.

  6. pH and urea dependence of amide hydrogen-deuterium exchange rates in the beta-trefoil protein hisactophilin.

    PubMed

    Houliston, R Scott; Liu, Chengsong; Singh, Laila M R; Meiering, Elizabeth M

    2002-01-29

    Amide hydrogen/deuterium exchange rates were measured as a function of pH and urea for 37 slowly exchanging amides in the beta-trefoil protein hisactophilin. The rank order of exchange rates is generally maintained under different solution conditions, and trends in the pH and urea dependence of exchange rates are correlated with the rank order of exchange rates. The observed trends are consistent with the expected behavior for exchange of different amides via global and/or local unfolding. Analysis of the pH dependence of exchange in terms of rate constants for structural opening and closing reveals a wide range of rates in different parts of the hisactophilin structure. The slowest exchanging amides have the slowest opening and closing rates. Many of the slowest exchanging amides are located in trefoil 2, but there are also some slow exchanging amides in trefoils 1 and 3. Slow exchangers tend to be near the interface between the beta-barrel and the beta-hairpin triplet portions of this single-domain structure. The pattern of exchange behaviour in hisactophilin is similar to that observed previously in interleukin-1 beta, indicating that exchange properties may be conserved among beta-trefoil proteins. Comparisons of opening and closing rates in hisactophilin with rates obtained for other proteins reveal clear trends for opening rates; however, trends in closing rates are less apparent, perhaps due to inaccuracies in the values used for intrinsic exchange rates in the data fitting. On the basis of the pH and urea dependence of exchange rates and optical measurements of stability and folding, EX2 is the main exchange mechanism in hisactophilin, but there is also evidence for varying levels of EX1 exchange at low and high pH and high urea concentrations. Equilibrium intermediates in which subglobal portions of structure are cooperatively disrupted are not apparent from analysis of the urea dependence of exchange rates. There is, however, a strong correlation between

  7. Temperature dependence of carbon isotope fractionation in CAM plants

    SciTech Connect

    Deleens, E.; Treichel, I.; O'Leary, M.H.

    1985-09-01

    The carbon isotope fractionation associated with nocturnal malic acid synthesis in Kalanchoe daigremontiana and Bryophyllum tubiflorum was calculated from the isotopic composition of carbon-4 of malic acid, after appropriate corrections. In the lowest temperature treatment (17/sup 0/C nights, 23/sup 0/C days), the isotope fractionation for both plants is -4% per thousand (that is, malate is enriched in /sup 13/C relative to the atmosphere). For K. daigremontiana, the isotope fractionation decreases with increasing temperature, becoming approximately 0% per thousand at 27/sup 0/C/33/sup 0/C. Detailed analysis of temperature effects on the isotope fractionation indicates that stomatal aperture decreases with increasing temperature and carboxylation capacity increases. For B. tubiflorum, the temperature dependence of the isotope fractionation is smaller and is principally attributed to the normal temperature dependences of the rates of diffusion and carboxylation steps. The small change in the isotopic composition of remaining malic acid in both species which is observed during deacidification indicates that malate release, rather than decarboxylation, is rate limiting in the deacidification process. 28 references, 1 figure, 4 tables.

  8. Temperature-dependent adsorption of hydrogen, deuterium, and neon on porous Vycor glass

    NASA Astrophysics Data System (ADS)

    Huber, T. E.; Scardino, D.; Tsou, H. L.

    1995-10-01

    Adsorption isotherms of H2, D2, and Ne have been measured in the temperature range from 15 K to the corresponding critical points in samples of porous Vycor glass. From the Brunauer-Emmett-Teller theory the surface layer coverages are determined. These are found to be temperature dependent. A model-independent approach allows us to fit the data for coverages ranging from submonolayer to thin film, below capillary condensation, for each adsorbate at all temperatures with a temperature-independent curve. This characteristic curve represents the distribution of adsorption sites versus the adsorption potential. In the intermediate coverage range, the isotherms exhibit the modified Frenkel-Halsey-Hill (FHH) behavior. The adsorption saturates for low-adsorption potentials. The characteristic curve is a useful universal curve since it is roughly the same for the three species investigated. We examine the relative strengths of the surface potentials and densities of the two isotopic modifications of hydrogen and of the more classical Ne adsorbed on porous Vycor glass. The characteristic adsorption curve is compared with results from two models for the adsorbate: Dubinin's isotherm for microporous solids and its extension to rough surfaces which places importance on the porosity of the surface, and Halsey's model, which is an extension of the FHH isotherm that takes into account the long-range variations of substrate adsorption potential.

  9. Does the obscured AGN fraction really depend on luminosity?

    NASA Astrophysics Data System (ADS)

    Sazonov, S.; Churazov, E.; Krivonos, R.

    2015-12-01

    We use a sample of 151 local non-blazar active galactic nuclei (AGN) selected from the INTEGRAL all-sky hard X-ray survey to investigate if the observed declining trend of the fraction of obscured (i.e. showing X-ray absorption) AGN with increasing luminosity is mostly an intrinsic or selection effect. Using a torus-obscuration model, we demonstrate that in addition to negative bias, due to absorption in the torus, in finding obscured AGN in hard X-ray flux-limited surveys, there is also positive bias in finding unobscured AGN, due to Compton reflection in the torus. These biases can be even stronger taking into account plausible intrinsic collimation of hard X-ray emission along the axis of the obscuring torus. Given the AGN luminosity function, which steepens at high luminosities, these observational biases lead to a decreasing observed fraction of obscured AGN with increasing luminosity even if this fraction has no intrinsic luminosity dependence. We find that if the central hard X-ray source in AGN is isotropic, the intrinsic (i.e. corrected for biases) obscured AGN fraction still shows a declining trend with luminosity, although the intrinsic obscured fraction is significantly larger than the observed one: the actual fraction is larger than ˜85 per cent at L ≲ 1042.5 erg s-1 (17-60 keV), and decreases to ≲60 per cent at L ≳ 1044 erg s-1. In terms of the half-opening angle θ of an obscuring torus, this implies that θ ≲ 30° in lower luminosity AGN, and θ ≳ 45° in higher luminosity ones. If, however, the emission from the central supermassive black hole is collimated as dL/dΩ ∝ cos α, the intrinsic dependence of the obscured AGN fraction is consistent with a luminosity-independent torus half-opening angle θ ˜ 30°.

  10. α-Tocopherol disappearance rates from plasma depend on lipid concentrations: studies using deuterium-labeled collard greens in younger and older adults.

    PubMed

    Traber, Maret G; Leonard, Scott W; Bobe, Gerd; Fu, Xueyan; Saltzman, Edward; Grusak, Michael A; Booth, Sarah L

    2015-04-01

    Little is known about α-tocopherol's bioavailability as a constituent of food or its dependence on a subject's age. To evaluate the α-tocopherol bioavailability from food, we used collard greens grown in deuterated water ((2)H collard greens) as a source of deuterium-labeled ((2)H) α-tocopherol consumed by younger and older adults in a post hoc analysis of a vitamin K study. Younger (mean ± SD age: 32 ± 7 y; n = 12 women and 9 men) and older (aged 67 ± 8 y; n = 8 women and 12 men) adults consumed a test breakfast that included 120 g (2)H collard greens (1.2 ± 0.1 mg (2)H-α-tocopherol). Plasma unlabeled α-tocopherol and (2)H-α-tocopherol were measured by using liquid chromatography-mass spectrometry from fasting (>12 h) blood samples drawn before breakfast (0 h) and at 24, 48, and 72 h and from postprandial samples collected at 4, 5, 6, 7, 9, 12, and 16 h. Times (12.6 ± 2.5 h) of maximum plasma (2)H-α-tocopherol concentrations (0.82% ± 0.59% total α-tocopherol), fractional disappearance rates (0.63 ± 0.26 pools/d), half-lives (30 ± 11 h), and the minimum estimated (2)H-α-tocopherol absorbed (24% ± 16%) did not vary between age groups or sexes (n = 41). Unlabeled α-tocopherol concentrations were higher in older adults (26.4 ± 8.6 μmol/L) than in younger adults (19.3 ± 4.2 μmol/L; P = 0.0019) and correlated with serum lipids (r = 0.4938, P = 0.0012). In addition, (2)H-α-tocopherol half-lives were correlated with lipids (r = 0.4361, P = 0.0044). Paradoxically, α-tocopherol remained in circulation longer in participants with higher serum lipids, but the (2)H-α-tocopherol absorbed was not dependent on the plasma lipid status. Neither variable was dependent on age. These data suggest that plasma α-tocopherol concentrations are more dependent on mechanisms that control circulating lipids rather than those related to its absorption and initial incorporation into plasma. This trial was registered at clinicaltrials.gov as NCT0036232. © 2015

  11. α-Tocopherol disappearance rates from plasma depend on lipid concentrations: studies using deuterium-labeled collard greens in younger and older adults1234

    PubMed Central

    Traber, Maret G; Leonard, Scott W; Bobe, Gerd; Fu, Xueyan; Saltzman, Edward; Grusak, Michael A; Booth, Sarah L

    2015-01-01

    Background: Little is known about α-tocopherol’s bioavailability as a constituent of food or its dependence on a subject’s age. Objective: To evaluate the α-tocopherol bioavailability from food, we used collard greens grown in deuterated water (2H collard greens) as a source of deuterium-labeled (2H) α-tocopherol consumed by younger and older adults in a post hoc analysis of a vitamin K study. Design: Younger (mean ± SD age: 32 ± 7 y; n = 12 women and 9 men) and older (aged 67 ± 8 y; n = 8 women and 12 men) adults consumed a test breakfast that included 120 g 2H collard greens (1.2 ± 0.1 mg 2H-α-tocopherol). Plasma unlabeled α-tocopherol and 2H-α-tocopherol were measured by using liquid chromatography–mass spectrometry from fasting (>12 h) blood samples drawn before breakfast (0 h) and at 24, 48, and 72 h and from postprandial samples collected at 4, 5, 6, 7, 9, 12, and 16 h. Results: Times (12.6 ± 2.5 h) of maximum plasma 2H-α-tocopherol concentrations (0.82% ± 0.59% total α-tocopherol), fractional disappearance rates (0.63 ± 0.26 pools/d), half-lives (30 ± 11 h), and the minimum estimated 2H-α-tocopherol absorbed (24% ± 16%) did not vary between age groups or sexes (n = 41). Unlabeled α-tocopherol concentrations were higher in older adults (26.4 ± 8.6 μmol/L) than in younger adults (19.3 ± 4.2 μmol/L; P = 0.0019) and correlated with serum lipids (r = 0.4938, P = 0.0012). In addition, 2H-α-tocopherol half-lives were correlated with lipids (r = 0.4361, P = 0.0044). Conclusions: Paradoxically, α-tocopherol remained in circulation longer in participants with higher serum lipids, but the 2H-α-tocopherol absorbed was not dependent on the plasma lipid status. Neither variable was dependent on age. These data suggest that plasma α-tocopherol concentrations are more dependent on mechanisms that control circulating lipids rather than those related to its absorption and initial incorporation into plasma. This trial was registered at

  12. Chemodynamical deuterium fractionation in the early solar nebula: The origin of water on earth and in asteroids and comets

    SciTech Connect

    Albertsson, T.; Semenov, D.; Henning, Th.

    2014-03-20

    Formation and evolution of water in the solar system and the origin of water on Earth constitute one of the most interesting questions in astronomy. The prevailing hypothesis for the origin of water on Earth is by delivery through water-rich small solar system bodies. In this paper, the isotopic and chemical evolution of water during the early history of the solar nebula, before the onset of planetesimal formation, is studied. A gas-grain chemical model that includes multiply deuterated species and nuclear spin-states is combined with a steady-state solar nebula model. To calculate initial abundances, we simulated 1 Myr of evolution of a cold and dark TMC-1-like prestellar core. Two time-dependent chemical models of the solar nebula are calculated over 1 Myr: (1) a laminar model and (2) a model with two-dimensional (2D) turbulent mixing. We find that the radial outward increase of the H{sub 2}O D/H ratio is shallower in the chemodynamical nebular model than in the laminar model. This is related to more efficient defractionation of HDO via rapid gas-phase processes because the 2D mixing model allows the water ice to be transported either inward and thermally evaporated or upward and photodesorbed. The laminar model shows the Earth water D/H ratio at r ≲ 2.5 AU, whereas for the 2D chemodynamical model this zone is larger, r ≲ 9 AU. Similarly, the water D/H ratios representative of the Oort-family comets, ∼2.5-10 × 10{sup –4}, are achieved within ∼2-6 AU and ∼2-20 AU in the laminar and the 2D model, respectively. We find that with regards to the water isotopic composition and the origin of the comets, the mixing model seems to be favored over the laminar model.

  13. Chemodynamical Deuterium Fractionation in the Early Solar Nebula: The Origin of Water on Earth and in Asteroids and Comets

    NASA Astrophysics Data System (ADS)

    Albertsson, T.; Semenov, D.; Henning, Th.

    2014-03-01

    Formation and evolution of water in the solar system and the origin of water on Earth constitute one of the most interesting questions in astronomy. The prevailing hypothesis for the origin of water on Earth is by delivery through water-rich small solar system bodies. In this paper, the isotopic and chemical evolution of water during the early history of the solar nebula, before the onset of planetesimal formation, is studied. A gas-grain chemical model that includes multiply deuterated species and nuclear spin-states is combined with a steady-state solar nebula model. To calculate initial abundances, we simulated 1 Myr of evolution of a cold and dark TMC-1-like prestellar core. Two time-dependent chemical models of the solar nebula are calculated over 1 Myr: (1) a laminar model and (2) a model with two-dimensional (2D) turbulent mixing. We find that the radial outward increase of the H2O D/H ratio is shallower in the chemodynamical nebular model than in the laminar model. This is related to more efficient defractionation of HDO via rapid gas-phase processes because the 2D mixing model allows the water ice to be transported either inward and thermally evaporated or upward and photodesorbed. The laminar model shows the Earth water D/H ratio at r <~ 2.5 AU, whereas for the 2D chemodynamical model this zone is larger, r <~ 9 AU. Similarly, the water D/H ratios representative of the Oort-family comets, ~2.5-10 × 10-4, are achieved within ~2-6 AU and ~2-20 AU in the laminar and the 2D model, respectively. We find that with regards to the water isotopic composition and the origin of the comets, the mixing model seems to be favored over the laminar model.

  14. Effect of deuterium on polystyrene degradation

    SciTech Connect

    Korshak, V.V.; Pavlova, S.S.A.; Gribkova, P.N.; Kozyreva, N.M.; Balykova, T.N.; Kirilin, A.I.

    1988-01-01

    The effect of replacing hydrogen by deuterium in polystyrene was studied on resistance to oxidative and thermal degradation. Polystyrene, polydeutero-styrene-D/sub 8/ containing 98-99 at.% deuterium, and a series of their statistical copolymers containing various proportions of deuterated and undeuterated monomer units were synthesized. The replacement of hydrogen by deuterium in polystyrene caused some increase in its resistance to thermal and oxidative destruction. A table shows that at all test temperatures, an increase in the fraction of deuterated monomer units in copolymer decreases the amounts of absorbed oxygen and evolved carbon oxides which is evidence for retadation of polystyrene oxidation when hydrogen is replaced by deuterium.

  15. Microbial mass-dependent fractionation of chromium isotopes

    USGS Publications Warehouse

    Sikora, E.R.; Johnson, T.M.; Bullen, T.D.

    2008-01-01

    Mass-dependent fractionation of Cr isotopes occurs during dissimilatory Cr(VI) reduction by Shewanella oneidensis strain MR-1. Cells suspended in a simple buffer solution, with various concentrations of lactate or formate added as electron donor, reduced 5 or 10 ??M Cr(VI) to Cr(III) over days to weeks. In all nine batch experiments, 53Cr/52Cr ratios of the unreacted Cr(VI) increased as reduction proceeded. In eight experiments covering a range of added donor concentrations up to 100 ??M, isotopic fractionation factors were nearly invariant, ranging from 1.0040 to 1.0045, with a mean value somewhat larger than that previously reported for abiotic Cr(VI) reduction (1.0034). One experiment containing much greater donor concentration (10 mM lactate) reduced Cr(VI) much faster and exhibited a lesser fractionation factor (1.0018). These results indicate that 53Cr/52Cr measurements should be effective as indicators of Cr(VI) reduction, either bacterial or abiotic. However, variability in the fractionation factor is poorly constrained and should be studied for a variety of microbial and abiotic reduction pathways. ?? 2008 Elsevier Ltd.

  16. Microbial mass-dependent fractionation of chromium isotopes

    NASA Astrophysics Data System (ADS)

    Sikora, Eric R.; Johnson, Thomas M.; Bullen, Thomas D.

    2008-08-01

    Mass-dependent fractionation of Cr isotopes occurs during dissimilatory Cr(VI) reduction by Shewanella oneidensis strain MR-1. Cells suspended in a simple buffer solution, with various concentrations of lactate or formate added as electron donor, reduced 5 or 10 μM Cr(VI) to Cr(III) over days to weeks. In all nine batch experiments, 53Cr/ 52Cr ratios of the unreacted Cr(VI) increased as reduction proceeded. In eight experiments covering a range of added donor concentrations up to 100 μM, isotopic fractionation factors were nearly invariant, ranging from 1.0040 to 1.0045, with a mean value somewhat larger than that previously reported for abiotic Cr(VI) reduction (1.0034). One experiment containing much greater donor concentration (10 mM lactate) reduced Cr(VI) much faster and exhibited a lesser fractionation factor (1.0018). These results indicate that 53Cr/ 52Cr measurements should be effective as indicators of Cr(VI) reduction, either bacterial or abiotic. However, variability in the fractionation factor is poorly constrained and should be studied for a variety of microbial and abiotic reduction pathways.

  17. Astration of cosmological deuterium

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1985-01-01

    Attention is given to the degree of primordial deuterium's astration through the continuous galactic processes of star formation and chemical evolution. Exact analytic solutions are given for galactic chemical evolution when infall of constant composition occurs at a rate, f(t), which is presently defined. Solutions are given for the linear model with instantaneous recycling and with constant return fraction R. The results suggest that big bang D/H was at least three times larger than the largest values observed in today's solar neighborhood, and even larger if matter falling into the disk is already astrated.

  18. Mass dependent molybdenum isotope fractionation in iron meteorites

    NASA Astrophysics Data System (ADS)

    Liang, Y. H.; Halliday, A. N.

    2016-12-01

    We report the mass dependent fractionation of molybdenum (Mo) isotopes for 23 magmatic iron meteorites from Groups IC, IIAB, IIIAB, IIIF and IVA. The δ98/95MoSRM3134 values vary from -0.24±0.06 to 0.28±0.04‰ with a chondritic average (-0.14±0.18‰). Most iron meteorites have δ98/95MoSRM3134 of -0.24 to -0.10‰, which is similar to the compositions of bulk ordinary and CI carbonaceous chondrites. Replicate dissolutions for five of the meteorites yield consistent data but Sikhote-Alin (IIAB) and Gibeon (IVA) display small differences between aliquots suggesting that the Mo isotopic composition can vary within a single iron meteorite. This is likely due to Mo isotopes fractionating between different phases. The IVA irons (10 meteorites) demonstrate the Mo isotopes become heavier at high indices of fractional crystallization such as As or Au concentration. The heaviest, Duel Hill, has an extremely heavy δ98/95MoSRM3134 of 0.28±0.04‰. The Mo/Au ratios provide supporting evidence that Mo is being removed during core differentiation.

  19. Tokamak power reactor ignition and time dependent fractional power operation

    SciTech Connect

    Vold, E.L.; Mau, T.K.; Conn, R.W.

    1986-06-01

    A flexible time-dependent and zero-dimensional plasma burn code with radial profiles was developed and employed to study the fractional power operation and the thermal burn control options for an INTOR-sized tokamak reactor. The code includes alpha thermalization and a time-dependent transport loss which can be represented by any one of several currently popular scaling laws for energy confinement time. Ignition parameters were found to vary widely in density-temperature (n-T) space for the range of scaling laws examined. Critical ignition issues were found to include the extent of confinement time degradation by alpha heating, the ratio of ion to electron transport power loss, and effect of auxiliary heating on confinement. Feedback control of the auxiliary power and ion fuel sources are shown to provide thermal stability near the ignition curve.

  20. ALCHEMIC: Advanced time-dependent chemical kinetics

    NASA Astrophysics Data System (ADS)

    Semenov, Dmitry A.

    2017-08-01

    ALCHEMIC solves chemical kinetics problems, including gas-grain interactions, surface reactions, deuterium fractionization, and transport phenomena and can model the time-dependent chemical evolution of molecular clouds, hot cores, corinos, and protoplanetary disks.

  1. Deuterium enrichment of interstellar dusts

    NASA Astrophysics Data System (ADS)

    Das, Ankan; Chakrabarti, Sandip Kumar; Majumdar, Liton; Sahu, Dipen

    2016-07-01

    High abundance of some abundant and simple interstellar species could be explained by considering the chemistry that occurs on interstellar dusts. Because of its simplicity, the rate equation method is widely used to study the surface chemistry. However, because the recombination efficiency for the formation of any surface species is highly dependent on various physical and chemical parameters, the Monte Carlo method is best suited for addressing the randomness of the processes. We carry out Monte-Carlo simulation to study deuterium enrichment of interstellar grain mantle under various physical conditions. Based on the physical properties, various types of clouds are considered. We find that in diffuse cloud regions, very strong radiation fields persists and hardly a few layers of surface species are formed. In translucent cloud regions with a moderate radiation field, significant number of layers would be produced and surface coverage is mainly dominated by photo-dissociation products such as, C, CH_3, CH_2D, OH and OD. In the intermediate dense cloud regions (having number density of total hydrogen nuclei in all forms ˜2 × 10^4 cm^{-3}), water and methanol along with their deuterated derivatives are efficiently formed. For much higher density regions (˜10^6 cm^{-3}), water and methanol productions are suppressed but surface coverage of CO, CO_2, O_2, O_3 are dramatically increased. We find a very high degree of fractionation of water and methanol. Observational results support a high fractionation of methanol but surprisingly water fractionation is found to be low. This is in contradiction with our model results indicating alternative routes for de-fractionation of water.

  2. Measured fraction of carboxyhaemoglobin depends on oxygen saturation of haemoglobin.

    PubMed

    Hütler, M; Beneke, R; Littschwager, A; Böning, D

    2001-02-01

    The use of the OSM3 oximeter for measurement of the fraction of carboxyhaemoglobin (FCOHb) in blood allows for estimation of total circulating haemoglobin mass (Hb(tot)) by using the carbon monoxide rebreathing method. To ensure high accuracy of Hb(tot) estimation, potential sources of analytical errors should be identified and adjusted for. Based on observed differences in results of measured FCOHb between simultaneously sampled, arterialized and venous blood samples we investigated the influence of haemoglobin oxygen saturation (sO2) on results of measured FCOHb. Blood from nine healthy non-smokers was tonometered with gas mixtures containing 94% N2 or air and 6% CO2. The resulting oxygenated and deoxygenated specimens were mixed in different proportions to obtain varying sO2 values in the same blood. sO2, fractions of dyshaemoglobins, pO2, pCO2 and pH were measured at each step. FCOHb was significantly (p<0.001) higher in oxygenated (median, range: 0.6%, 0.4-0.9%) compared to deoxygenated (-0.2%, -0.5-0.0%) blood. Regression analysis identified the sO2 as the most important factor explaining 86% of the variance in observed changes in FCOHb. The observed sO2 effect has important implications on calibration procedure of OSM3, accuracy of measured FCOHb, and FCOHb dependent calculations such as estimation of Hb(tot) and related quantities. If the highest accuracy of FCOHb measurement is needed, an sO2 effect on results of measured FCOHb has to be considered and adjusted for.

  3. DEPENDENCE OF BARRED GALAXY FRACTION ON GALAXY PROPERTIES AND ENVIRONMENT

    SciTech Connect

    Lee, Gwang-Ho; Lee, Myung Gyoon; Park, Changbom; Choi, Yun-Young E-mail: mglee@astro.snu.ac.kr E-mail: yy.choi@khu.ac.kr

    2012-02-01

    We investigate the dependence of the occurrence of bars in galaxies on galaxy properties and environment. We use a volume-limited sample of 33,391 galaxies brighter than M{sub r} = -19.5 + 5logh at 0.02 {<=} z {<=} 0.05489, drawn from the Sloan Digital Sky Survey Data Release 7. We classify the galaxies into early and late types, and identify bars by visual inspection. Among 10,674 late-type galaxies with axis ratio b/a > 0.60, we find 3240 barred galaxies (f{sub bar} = 30.4%) which divide into 2542 strong bars (f{sub SB1} = 23.8%) and 698 weak bars (f{sub SB2} = 6.5%). We find that f{sub SB1} increases as u - r color becomes redder and that it has a maximum value at intermediate velocity dispersion ({sigma} {approx_equal}150 km s{sup -1}). This trend suggests that strong bars are dominantly hosted by intermediate-mass systems. Weak bars prefer bluer galaxies with lower mass and lower concentration. In the case of strong bars, their dependence on the concentration index appears only for massive galaxies with {sigma} > 150 km s{sup -1}. We also find that f{sub bar} does not directly depend on the large-scale background density when other physical parameters (u - r color or {sigma}) are fixed. We discover that f{sub SB1} decreases as the separation to the nearest neighbor galaxy becomes smaller than 0.1 times the virial radius of the neighbor regardless of neighbor's morphology. These results imply that strong bars are likely to be destroyed during strong tidal interactions and that the mechanism for this phenomenon is gravitational and not hydrodynamical. The fraction of weak bars has no correlation with environmental parameters. We do not find any direct evidence for environmental stimulation of bar formation.

  4. Deuterium in carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Kolodny, Y.; Kerridge, J. F.; Kaplan, I. R.

    1980-01-01

    Hydrogen isotopic compositions in seven carbonaceous chondrites lie in the range -70 to +771 per thousand relative to standard mean ocean water. These values decrease, to a range from -145 to +219 per thousand, after low-temperature oxidation in an oxygen plasma. Deuterium enrichment is therefore concentrated in the organic matter, the hydrous silicates probably lying close to the terrestrial range for such material. Calculated values for delta D of the organic fraction are +450 per thousand for Orgueil and Ivuna and up to +1600 per thousand for Renazzo. These enrichments, at least for Orgueil and Ivuna, suggest equilibration with protosolar hydrogen at very low temperatures. Assuming a value of 2.5 x 10 to the -5th for the protosolar D/H ratio, nominal equilibration temperatures of 230 K for silicates and 180 K for organic matter may be derived.

  5. Mass-dependent fractionation of nickel isotopes in meteoritic metal

    NASA Astrophysics Data System (ADS)

    Cook, David L.; Wadhwa, Meenakshi; Clayton, Robert N.; Dauphas, Nicolas; Janney, Philip E.; Davis, Andrew M.

    We measured nickel isotopes via multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) in the bulk metal from 36 meteorites, including chondrites, pallasites, and irons (magmatic and non-magmatic). The Ni isotopes in these meteorites are mass fractionated; the fractionation spans an overall range of ≈0.4‰ amu-1. The ranges of Ni isotopic compositions (relative to the SRM 986 Ni isotopic standard) in metal from iron meteorites (≈0.0 to ≈0.3‰ amu-1) and chondrites (≈0.0 to ≈0.2‰ amu-1) are similar, whereas the range in pallasite metal (≈-0.1 to 0.0‰ amu-1) appears distinct. The fractionation of Ni isotopes within a suite of fourteen IIIAB irons (≈0.0 to ≈0.3‰ amu-1) spans the entire range measured in all magmatic irons. However, the degree of Ni isotopic fractionation in these samples does not correlate with their Ni content, suggesting that core crystallization did not fractionate Ni isotopes in a systematic way. We also measured the Ni and Fe isotopes in adjacent kamacite and taenite from the Toluca IAB iron meteorite. Nickel isotopes show clearly resolvable fractionation between these two phases; kamacite is heavier relative to taenite by ≈0.4‰ amu-1. In contrast, the Fe isotopes do not show a resolvable fractionation between kamacite and taenite. The observed isotopic compositions of kamacite and taenite can be understood in terms of kinetic fractionation due to diffusion of Ni during cooling of the Fe-Ni alloy and the development of the Widmanstätten pattern.

  6. Exploring the Origins of Deuterium Enrichments in Solar Nebular Organics

    NASA Astrophysics Data System (ADS)

    Cleeves, L. Ilsedore; Bergin, Edwin A.; O'D. Alexander, Conel M.; Du, Fujun; Graninger, Dawn; Öberg, Karin I.; Harries, Tim J.

    2016-03-01

    Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies generally have higher D/H ratios and show greater D/H variation when compared to D/H in solar system water. We propose this difference arises at least in part due to (1) the availability of additional chemical fractionation pathways for organics beyond that for water, and (2) the higher volatility of key carbon reservoirs compared to oxygen. We test this hypothesis using detailed disk models, including a sophisticated, new disk ionization treatment with a low cosmic-ray ionization rate, and find that disk chemistry leads to higher deuterium enrichment in organics compared to water, helped especially by fractionation via the precursors CH2D+/CH3+. We also find that the D/H ratio in individual species varies significantly depending on their particular formation pathways. For example, from ˜20-40 au, CH4 can reach {{D}}/{{H}}˜ 2× {10}-3, while D/H in CH3OH remains locally unaltered. Finally, while the global organic D/H in our models can reproduce intermediately elevated D/H in the bulk hydrocarbon reservoir, our models are unable to reproduce the most deuterium-enriched organic materials in the solar system, and thus our model requires some inheritance from the cold interstellar medium from which the Sun formed.

  7. Muon capture in deuterium

    NASA Astrophysics Data System (ADS)

    Ricci, P.; Truhlík, E.; Mosconi, B.; Smejkal, J.

    2010-06-01

    Model dependence of the capture rates of the negative muon capture in deuterium is studied starting from potential models and the weak two-body meson exchange currents constructed in the tree approximation and also from an effective field theory. The tree one-boson exchange currents are derived from the hard pion chiral Lagrangians of the NΔπρωa system. If constructed in conjunction with the one-boson exchange potentials, the capture rates can be calculated consistently. On the other hand, the effective field theory currents, constructed within the heavy baryon chiral perturbation theory, contain a low energy constant d that cannot be extracted from data at the one-particle level nor determined from the first principles. Comparative analysis of the results for the doublet transition rate allows us to extract the constant d.

  8. Stable strontium mass dependent isotopic fractionation in authigenic continental barite

    NASA Astrophysics Data System (ADS)

    Griffith, E. M.; Widanagamage, I. H.; Scher, H. D.; Senko, J.

    2013-12-01

    The use of stable Sr-isotopic measurements (δ88Sr) of barite precipitates from terrestrial environments will be evaluated as a new geochemical proxy to identify mode of barite mineralization for use in earth science applications including understanding similar ancient barite deposits. Stable Sr-isotope measurements of barite and waters from three warm artesian springs in the continental United States where barite precipitates under a variety of conditions (e.g., temperatures, saturation states, microbial communities) will be presented. Initial results show a large range of fractionation factors during barite precipitation from aqueous solution between and within some of the field sites of >0.6 permil. The waters range from δ88Sr = -0.04 to +0.50 permil. The solid barite precipitates that have been separated from the bulk sediment using a modified sequential leaching procedure range from δ88Sr = -0.43 to +0.16 permil. Average 2σ for the isotopic analyses is 0.05 permil, similar to previously published estimates for error on this measurement by MC-ICPMS. Barite is a highly stable and widely-distributed mineral found in magmatic, metamorphic, and sedimentary rocks (of all ages), as well as in soils, aerosol dust, and extraterrestrial material. Establishing the controlling parameters of stable Sr-isotopic fractionation in barite is important as barite may be an ideal vehicle to address critical questions in the earth sciences, including early earth biogeochemistry.

  9. THE ENVIRONMENTAL DEPENDENCE OF THE EVOLVING S0 FRACTION

    SciTech Connect

    Just, Dennis W.; Zaritsky, Dennis; Sand, David J.; Desai, Vandana; Rudnick, Gregory

    2010-03-01

    We re-investigate the dramatic rise in the S0 fraction, f{sub S0}, within clusters since z {approx} 0.5. In particular, we focus on the role of the global galaxy environment on f{sub S0} by compiling, either from our own observations or the literature, robust line-of-sight velocity dispersions, sigma's, for a sample of galaxy groups and clusters at 0.1 < z < 0.8 that have uniformly determined, published morphological fractions. We find that the trend of f{sub S0} with redshift is twice as strong for sigma < 750 km s{sup -1} groups/poor clusters than for higher-sigma, rich clusters. From this result, we infer that over this redshift range galaxy-galaxy interactions, which are more effective in lower-sigma environments, are more responsible for transforming spiral galaxies into S0's than galaxy-environment processes, which are more effective in higher-sigma environments. The rapid, recent growth of the S0 population in groups and poor clusters implies that large numbers of progenitors exist in low-sigma systems at modest redshifts ({approx}0.5), where morphologies and internal kinematics are within the measurement range of current technology.

  10. Molecular weight dependence of segmental alignment in a sheared polymer melt: A deuterium nuclear magnetic resonance investigation

    NASA Astrophysics Data System (ADS)

    Cormier, Ryan J.; Callaghan, Paul T.

    2002-06-01

    2H NMR quadrupole interaction spectroscopy has been used to measure the molecular weight dependence of poly(dimethylsiloxane) chain deformation under shear in a cylindrical Couette cell while NMR velocimetry has been used to directly measure shear rates. The signals were acquired from a perdeuterated benzene probe molecule, which provides a motionally averaged sampling of the entire segmental ensemble. We have measured the dependence on shear rate of the SXX (velocity), SYY (velocity gradient), and SZZ (vorticity) elements of the segmented alignment tensor, fitting the data using the standard Doi-Edwards theory and modified to allow for convected constraint release. Our results suggest that the tube disengagement times scale as molecular weight to the power 3.5±0.1, consistent with the usual 3.4 power law. Our velocimetry measurements indicate a reproducible and consistent slip occurring at high molecular weights (>1 M Dalton), a phenomenon which is independently observed in a lower than expected chain deformation.

  11. Temperature effect on leaf water deuterium enrichment and isotopic fractionation during leaf lipid biosynthesis: results from controlled growth of C3 and C4 land plants.

    PubMed

    Zhou, Youping; Grice, Kliti; Chikaraishi, Yoshito; Stuart-Williams, Hilary; Farquhar, Graham D; Ohkouchi, Naohiko

    2011-02-01

    The hydrogen isotopic ratios ((2)H/(1)H) of land plant leaf water and the carbon-bound hydrogen of leaf wax lipids are valuable indicators for climatic, physiological, metabolic and geochemical studies. Temperature will exert a profound effect on the stable isotopic composition of leaf water and leaf lipids as it directly influences the isotopic equilibrium (IE) during leaf water evaporation and cellular water dissociation. It is also expected to affect the kinetics of enzymes involved in lipid biosynthesis, and therefore the balance of hydrogen inputs along different biochemical routes. We conducted a controlled growth experiment to examine the effect of temperature on the stable hydrogen isotopic composition of leaf water and the biological and biochemical isotopic fractionations during lipid biosynthesis. We find that leaf water (2)H enrichment at 20°C is lower than that at 30°C. This is contrary to the expectation that at lower temperatures leaf water should be more enriched in (2)H due to a larger equilibrium isotope effect associated with evapotranspiration from the leaf if all other variables are held constant. A hypothesis is presented to explain the apparent discrepancy whereby lower temperature-induced down-regulation of available aquaporin water channels and/or partial closure of transmembrane water channel forces water flow to "detour" to a more convoluted apoplastic pathway, effectively increasing the length over which diffusion acts against advection as described by the Péclet effect (Farquhar and Lloyd, 1993) and decreasing the average leaf water enrichment. The impact of temperature on leaf water enrichment is not reflected in the biological isotopic fractionation or the biochemical isotopic fractionation during lipid biosynthesis. Neither the biological nor biochemical fractionations at 20°C are significantly different from that at 30°C, implying that temperature has a negligible effect on the isotopic fractionation during lipid biosynthesis

  12. A Ca2+-stimulated, Mg2+-dependent ATPase activity in subcellular fractions from Schistosoma mansoni.

    PubMed

    Cunha, V M; de Souza, W; Noël, F

    1988-12-05

    A Ca2+-stimulated, Mg2+-dependent ATPase activity was found in subcellular fractions from Schistosoma mansoni. Its specific and relative activities were higher in the heterogeneous cuticle fraction and in the microsomal fraction. The K0.5 for ATPase activation by free Ca2+ was 0.2-0.5 microM. This is the first description of an ATPase activity stimulated by Ca2+ in the micromolar range in S. mansoni.

  13. Metabolite identification of triptolide by data-dependent accurate mass spectrometric analysis in combination with online hydrogen/deuterium exchange and multiple data-mining techniques.

    PubMed

    Du, Fuying; Liu, Ting; Liu, Tian; Wang, Yongwei; Wan, Yakun; Xing, Jie

    2011-10-30

    Triptolide (TP), the primary active component of the herbal medicine Tripterygium wilfordii Hook F, has shown promising antileukemic and anti-inflammatory activity. The pharmacokinetic profile of TP indicates an extensive metabolic elimination in vivo; however, its metabolic data is rarely available partly because of the difficulty in identifying it due to the absence of appropriate ultraviolet chromophores in the structure and the presence of endogenous interferences in biological samples. In the present study, the biotransformation of TP was investigated by improved data-dependent accurate mass spectrometric analysis, using an LTQ/Orbitrap hybrid mass spectrometer in conjunction with the online hydrogen (H)/deuterium (D) exchange technique for rapid structural characterization. Accurate full-scan MS and MS/MS data were processed with multiple post-acquisition data-mining techniques, which were complementary and effective in detecting both common and uncommon metabolites from biological matrices. As a result, 38 phase I, 9 phase II and 8 N-acetylcysteine (NAC) metabolites of TP were found in rat urine. Accurate MS/MS data were used to support assignments of metabolite structures, and online H/D exchange experiments provided additional evidence for exchangeable hydrogen atoms in the structure. The results showed the main phase I metabolic pathways of TP are hydroxylation, hydrolysis and desaturation, and the resulting metabolites subsequently undergo phase II processes. The presence of NAC conjugates indicated the capability of TP to form reactive intermediate species. This study also demonstrated the effectiveness of LC/HR-MS(n) in combination with multiple post-acquisition data-mining methods and the online H/D exchange technique for the rapid identification of drug metabolites. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Structure-dependent deuterium release from ion implanted beryllium: Comparison between Be(1 1 2¯ 0) and Be(poly)

    NASA Astrophysics Data System (ADS)

    Oberkofler, M.; Reinelt, M.; Lindig, S.; Linsmeier, Ch.

    2009-02-01

    The temperature-driven release of deuterium implanted as keV ions into metallic beryllium is measured by temperature-programmed desorption (TPD). TPD spectra from single and polycrystalline Be implanted with 1 keV ions are compared. The high-temperature desorption stage (T > 700 K) is attributed to the release of deuterium trapped at several types of energetically different ion-induced defects. A release peak around 850 K is recorded in the single crystal, while in the polycrystal all deuterium desorbs below this temperature. An increase in the maximum release temperature is observed after implantation of the polycrystal with higher ion energies (2 and 3 keV). We propose an interpretation of the experimental results based on two types of traps, with depth distributions adapted to the implantation energy. Preliminary TMAP7 calculations qualitatively reproduce the shifts in the maximum desorption temperature, observed in the polycrystal at different implantation energies. The difference between the single and the polycrystal is explained by a higher density of surviving defects in the single crystal. Diffusion of mobile defects to grain boundaries and subsequent annihilation is proposed as the dominant mechanism for differences in deuterium desorption from Be(1 1 2 bar 0) and Be(poly).

  15. Temperature dependency of the triple isotope fractionation relationship for equilibrium processes

    NASA Astrophysics Data System (ADS)

    Hayles, J. A.; Cao, X.; Bao, H.

    2015-12-01

    The use of an approximation to the Bigeleisen-Mayer-Urey model for isotope fractionation has led to the concept of a constant, and later constrained, mass fractionation law for multiple isotopes of the same element. This concept has brought new insights to investigation in photochemistry, radical chemistry, or the contribution of quantum tunneling to chemical and biological processes. Despite previous work indicating that these mass fractionation laws can be highly variable, the concept of a constant relationship remains common in these fields. Using the diatomic case as a first-order approximation, we demonstrate generically that the mass fractionation exponent, θ, can take any value for small fractionations but is less variable for large fractionations. The predicted variability is larger than both theoretical and analytical precision. These deviations from the traditional range of mass-dependence exponents are the largest under cross-over scenarios, but can occur for any scenario with small fractionations. We advocate the use of ∆∆‡M or "change in cap-delta", defined strictly with a slope of at the high-temperature limit, as a necessary, more reliable and more useful descriptor of mass-dependent fractionation. This work can bring new insights and a conventional explanation to low temperature experiments yielding traditionally unusual mass fractionation laws.

  16. Mass-dependent and -independent fractionation of isotopes in Ni and Pb chelate complex formation reactions

    NASA Astrophysics Data System (ADS)

    Nomura, Masao; Kudo, Takashi; Adachi, Atsuhiko; Aida, Masao; Fujii, Yasuhiko

    2013-11-01

    Mass independent fractionation (MIF) has been a very interesting topic in the field of inorganic isotope chemistry, in particular, geo- and cosmo- chemistry. In the present work, we studied the isotope fractionation of Ni(II) and Pb(II) ions in complex formation with chelating reagent EDTA. To obtain clear results on the mass dependence of the isotope fractionation, we have conducted long-distance ion exchange chromatography of Ni(II) and Pb(II), using chelate complex reagent EDTA. The results apparently show that the isotope fractionation in Ni complex formation system is governed by the mass dependent rule. On the other hand the isotope fractionation in the Pb complex system is governed by the mass independent rule or the nuclear volume effect.

  17. Mass-dependent and -independent fractionation of isotopes in Ni and Pb chelate complex formation reactions

    SciTech Connect

    Nomura, Masao; Kudo, Takashi; Adachi, Atsuhiko; Aida, Masao; Fujii, Yasuhiko

    2013-11-13

    Mass independent fractionation (MIF) has been a very interesting topic in the field of inorganic isotope chemistry, in particular, geo- and cosmo- chemistry. In the present work, we studied the isotope fractionation of Ni(II) and Pb(II) ions in complex formation with chelating reagent EDTA. To obtain clear results on the mass dependence of the isotope fractionation, we have conducted long-distance ion exchange chromatography of Ni(II) and Pb(II), using chelate complex reagent EDTA. The results apparently show that the isotope fractionation in Ni complex formation system is governed by the mass dependent rule. On the other hand the isotope fractionation in the Pb complex system is governed by the mass independent rule or the nuclear volume effect.

  18. Deuterium in the daytime thermosphere

    NASA Technical Reports Server (NTRS)

    Breig, E. L.; Sanatani, S.; Hanson, W. B.

    1987-01-01

    Ion concentration measurements for H(+) and D(+) from the magnetic ion mass spectrometer on the Atmosphere Explorer C satellite are used, in conjunction with other atmospheric data, to determine the concentrations of H and D in the nonpolar daytime thermosphere. The ratio of the observed D(+) to H(+) concentrations has essentially the same height dependence in the 300 to 800-km region as expected for their neutral counterparts, even in the presence of ion temperature gradients and probable large vertical ion fluxes. Rapid charge exchange with atomic oxygen ensures that D/H is about equal to D(+)/H(+) at the lower altitudes where the derived D to H concentration ratio is a factor of about 6 larger than its sea level value, for an exospheric temperature of 930 K. This relative enhancement of deuterium arises from the fact that hydrogen more readily escapes the earth, and a large vertical gradient in the H concentration relative to its diffusive equilibrium value is necessary to drive this upward flux through the lower thermosphere. If these planetary losses of hydrogen are much greater than those associated with evaporative escape, as is the current view, then correspondingly larger deuterium loss rates are also likely in order that the thermospheric D/H ratio not increase well above the observed value. The absolute winter daytime concentration of deuterium at 300 km is found to be 210 + or - 50 atoms/cu cm.

  19. The dependencies of phase velocity and dispersion on volume fraction in cancellous-bone-mimicking phantoms.

    PubMed

    Wear, Keith A

    2009-02-01

    Frequency-dependent phase velocity was measured in eight cancellous-bone-mimicking phantoms consisting of suspensions of randomly oriented nylon filaments (simulating trabeculae) in a soft-tissue-mimicking medium (simulating marrow). Trabecular thicknesses ranged from 152 to 356 mum. Volume fractions of nylon filament material ranged from 0% to 10%. Phase velocity varied approximately linearly with frequency over the range from 300 to 700 kHz. The increase in phase velocity (compared with phase velocity in a phantom containing no filaments) at 500 kHz was approximately proportional to volume fraction occupied by nylon filaments. The derivative of phase velocity with respect to frequency was negative and exhibited nonlinear, monotonically decreasing dependence on volume fraction. The dependencies of phase velocity and its derivative on volume fraction in these phantoms were similar to those reported in previous studies on (1) human cancellous bone and (2) phantoms consisting of parallel nylon wires immersed in water.

  20. Interstellar Deuterium Chemistry

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.

    2003-01-01

    The presence of isotopic anomalies is the most unequivocal demonstration that meteoritic material contains circumstellar or interstellar components. In the case of organic compounds in meteorites and interplanetary dust particles (IDPs), the most useful isotopic tracer of interstellar components has been deuterium (D) excesses. In some cases these enrichments are seen in bulk meteoritic materials, but D enrichments have also been observed in meteoritic subfractions and even within specific classes of molecular species, such as amino and carboxylic acids. These anomalies are not thought to be the result of nucleosynthetic processes, but are instead ascribed to chemical and physical processes occurring in the interstellar medium (ISM). The traditional explanation of these D excesses has been to invoke the presence of materials made in the ISM by low temperature gas phase ion-molecule reactions. Indeed, the DM ratios seen in the simple interstellar gas phase molecules in cold dense clouds amenable to measurement using radio spectral techniques are generally considerably higher than the values seen in enriched Solar System materials. However, the true linkage between the DM ratios in interstellar and meteoritic materials is obscured by several effects. First, current observations of D enrichment in the ISM have been made of only a few simple molecules, molecules that are not the main carriers of D in Solar System materials. Second, some of the interstellar D enrichment is likely to reside on labile moieties that will have exchanged to some degree with more isotopically normal material during incorporation into the warm protosolar nebula, parent body processing, delivery, recovery, and analysis. Third, ion-molecule reactions represent only one of at least four processes that can produce strong D-H fractionation in the ISM.

  1. EVIDENCE FOR MULTIPLE PATHWAYS TO DEUTERIUM ENHANCEMENTS IN PROTOPLANETARY DISKS

    SciTech Connect

    Oeberg, Karin I.; Qi, Chunhua; Wilner, David J.; Hogerheijde, Michiel R.

    2012-04-20

    The distributions of deuterated molecules in protoplanetary disks are expected to depend on the molecular formation pathways. We use observations of spatially resolved DCN emission from the disk around TW Hya, acquired during ALMA science verification with a {approx}3'' synthesized beam, together with comparable DCO{sup +} observations from the Submillimeter Array, to investigate differences in the radial distributions of these species and hence differences in their formation chemistry. In contrast to DCO{sup +}, which shows an increasing column density with radius, DCN is better fit by a model that is centrally peaked. We infer that DCN forms at a smaller radii and thus at higher temperatures than DCO{sup +}. This is consistent with chemical network model predictions of DCO{sup +} formation from H{sub 2}D{sup +} at T < 30 K and DCN formation from additional pathways involving CH{sub 2}D{sup +} at higher temperatures. We estimate a DCN/HCN abundance ratio of {approx}0.017, similar to the DCO{sup +}/HCO{sup +} abundance ratio. Deuterium fractionation appears to be efficient at a range of temperatures in this protoplanetary disk. These results suggest caution in interpreting the range of deuterium fractions observed in solar system bodies, as multiple formation pathways should be taken into account.

  2. (Un)true deuterium abundance in the Galactic disk

    NASA Astrophysics Data System (ADS)

    Prodanović, Tijana; Steigman, Gary; Fields, Brian D.

    2010-04-01

    Deuterium has a special place in cosmology, nuclear astrophysics, and galactic chemical evolution, because of its unique property that it is only created in the big bang nucleosynthesis while all other processes result in its net destruction. For this reason, among other things, deuterium abundance measurements in the interstellar medium (ISM) allow us to determine the fraction of interstellar gas that has been cycled through stars, and set constraints and learn about different Galactic chemical evolution (GCE) models. However, recent indications that deuterium might be preferentially depleted onto dust grains complicate our understanding about the meaning of measured ISM deuterium abundances. For this reason, recent estimates by Linsky et al. (2006) have yielded a lower bound to the “true”, undepleted, ISM deuterium abundance that is very close to the primordial abundance, indicating a small deuterium astration factor contrary to the demands of many GCE models. To avoid any prejudice about deuterium dust depletion along different lines of sight that are used to determine the “true” D abundance, we propose a model-independent, statistical Bayesian method to address this issue and determine in a model-independent manner the undepleted ISM D abundance. We find the best estimate for the gas-phase ISM deuterium abundance to be (D/H)ISM ≥ (2.0 ± 0.1) × 10-5. Presented are the results of Prodanović et al. (2009).

  3. Mass dependent isotope fractionation during impacts induced the Archaean mass-independent fractionation of sulphur: Evidence against Great Oxidation Event

    NASA Astrophysics Data System (ADS)

    Huang, H.

    2010-12-01

    A prevailing hypothesis, low-oxygen level of the Archaean atmosphere, relies strongly on the presence of strong mass-independent fractionation (MIF) of the sulfur isotopes in sulfide- and sulfate-bearing minerals older than 2.4 billion years. Actually, there is “a broad overlap between MIF signals observed within Archaean sedimentary sequences and periods of enhanced asteroid impacts represented by impact ejecta/fallout units”(Glikson 2010) (Fig. 1). Moreover, usually MIF- related sulphur occurs in the Archaean sedimentary rocks as pyrite (FeS2) which has been found in the K-T boundary clay beds and in several identified impact craters, which is an independent argument in favor of pyrites could be the product of impact. Impact processes (vaporization and condensation) are sufficient to explain the MIF signals following the principle: the earlier the condensed material, the more enriched in lighter isotopes (Huang 2010). The nature of the MIF of the sulfur isotopes is that the fractionation of isotope is still mass dependent during impacts, which means the measured nonzero Δ33S values of Archean sulfide- and sulfate-bearing minerals indicate that their different condensation sequences. Another important line of evidence that support the impact-generated MIF of the sulfur isotopes comes from the various iron isotope values of the pyrites especially those with iron isotope heterogeneity at grain scale. Thus, it is clear that the signals are the markers of impact rather than O2 poor atmosphere. Furthermore, this can also account for the lack of MIF-S in several Archaean units before 2.4 billion years. Figure 1 Plot of mass-independent fractionation of sulphur and asteroid impact events with age. Modified from Glikson (2010)

  4. Simultaneous inversion for the space-dependent diffusion coefficient and the fractional order in the time-fractional diffusion equation

    NASA Astrophysics Data System (ADS)

    Li, Gongsheng; Zhang, Dali; Jia, Xianzheng; Yamamoto, Masahiro

    2013-06-01

    This paper deals with an inverse problem of simultaneously identifying the space-dependent diffusion coefficient and the fractional order in the 1D time-fractional diffusion equation with smooth initial functions by using boundary measurements. The uniqueness results for the inverse problem are proved on the basis of the inverse eigenvalue problem, and the Lipschitz continuity of the solution operator is established. A modified optimal perturbation algorithm with a regularization parameter chosen by a sigmoid-type function is put forward for the discretization of the minimization problem. Numerical inversions are performed for the diffusion coefficient taking on different functional forms and the additional data having random noise. Several factors which have important influences on the realization of the algorithm are discussed, including the approximate space of the diffusion coefficient, the regularization parameter and the initial iteration. The inversion solutions are good approximations to the exact solutions with stability and adaptivity demonstrating that the optimal perturbation algorithm with the sigmoid-type regularization parameter is efficient for the simultaneous inversion.

  5. Correcting the initialization of models with fractional derivatives via history-dependent conditions

    NASA Astrophysics Data System (ADS)

    Du, Maolin; Wang, Zaihua

    2016-04-01

    Fractional differential equations are more and more used in modeling memory (history-dependent, non-local, or hereditary) phenomena. Conventional initial values of fractional differential equations are defined at a point, while recent works define initial conditions over histories. We prove that the conventional initialization of fractional differential equations with a Riemann-Liouville derivative is wrong with a simple counter-example. The initial values were assumed to be arbitrarily given for a typical fractional differential equation, but we find one of these values can only be zero. We show that fractional differential equations are of infinite dimensions, and the initial conditions, initial histories, are defined as functions over intervals. We obtain the equivalent integral equation for Caputo case. With a simple fractional model of materials, we illustrate that the recovery behavior is correct with the initial creep history, but is wrong with initial values at the starting point of the recovery. We demonstrate the application of initial history by solving a forced fractional Lorenz system numerically.

  6. Deuterium quantification through deuterium-induced remote 1H and 13C NMR shifts.

    PubMed

    Knorr, Rudolf; Stephenson, David S

    2012-06-11

    Partial labeling by deuterium may be quantified through simple integrations of those (1)H (200 or 400 MHz) and (13)C (100.6 MHz) NMR resonances that are split into pairs by chemical shifts (n)Δ = δ(deuterated) - δ(nondeuterated) as induced by deuterium across n>2 chemical bonds. The relative intensities of the two components of a pair are shown to be influenced to practically equal degrees by relaxation effects, so that a deuterium fraction may be determined from (1)H and (13)C integral pairs at more remote molecular positions under the routine conditions of fast accumulative spectral acquisition. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Wavelength-dependent isotope fractionation in visible light O3 photolysis and atmospheric implications

    NASA Astrophysics Data System (ADS)

    Früchtl, Marion; Janssen, Christof; Taraborrelli, Domenico; Gromov, Sergey; Röckmann, Thomas

    2015-10-01

    The 17O and 18O isotope fractionation associated with photolysis of O3 in the Chappuis band was determined using a broadband light source with cutoff filters at 455, 550, and 620 nm and narrowband light sources at 530, 617, and 660 nm. The isotope effects follow a mass-dependent fractionation pattern (δ17O/δ18O = 0.53). Contrary to theoretical predictions, fractionations are negative for all wavelength ranges investigated and do not change signs at the absorption cross-section maximum. Our measurements differ from theoretical calculations by as much as 34‰ in 18ɛO3+hν = (18J/16J - 1). The wavelength dependence is also weaker than predicted. Photo-induced fractionation is strongest when using a low-wavelength cutoff at 620 nm with 18ɛO3+hν = -26.9(±1.4)‰. With decreasing wavelength, fractionation values diminish to 18ɛO3+hν = -12.9(±1.3)‰ at 530 nm. Results from an atmospheric model demonstrate that visible light photolysis is the most important tropospheric sink of O3, which thus contributes about one sixth to the ozone enrichment.

  8. Deuterium astration in the local disc and beyond

    NASA Astrophysics Data System (ADS)

    Romano, Donatella; Tosi, Monica; Chiappini, Cristina; Matteucci, Francesca

    2006-06-01

    Estimates of the interstellar deuterium abundance span a wide range of values. Until recently, it was customary to adopt the abundance of deuterium measured in the Local Bubble as representative of the local one. Now, it is becoming unclear whether the true local deuterium abundance is significantly higher or lower than this value, depending on the interpretation given to current data. It is important to deal with the issue of the deuterium variation and see whether it challenges our current understanding of the Galaxy evolution. To this aim, we study the evolution of deuterium in the framework of successful models for the chemical evolution of the Milky Way able to reproduce the majority of the observational constraints for the solar neighbourhood and for the Galactic disc. We show that, in the framework of our models, the lowest D/H (deuterium-to-oxygen) values observed locally cannot be explained in terms of simple astration processes occurring during the Galaxy evolution. Indeed, the combination of a mild star formation and a continuous infall of unprocessed gas required to fit all the available observational data allows only a modest variation of the deuterium abundance from its primordial value. Therefore, we suggest that depletion of deuterium on to dust grains is the most likely physical mechanism proposed so far to explain the observed dispersion in the local data.

  9. Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.

    SciTech Connect

    Chakraborty, Subrata; Davis, Ryan; Ahmed, Musahid; Jackson, Teresa L.; Thiemens, Mark H.

    2012-01-03

    Several absorption bands exist in the VUV region of Carbon monoxide (CO). Emission spectra indicate that these bands are all predissociative. An experimental investigation of CO photodissociation by vacuum ultraviolet photons (90 to 108 nm; ~13 to 11 eV) from the Advanced Light Source Synchrotron and direct measurement of the associated oxygen isotopic composition of the products are presented here. A wavelength dependency of the oxygen isotopic composition in the photodissociation product was observed. Slope values (δ'{sup 18}O/ δ'{sup 17}O) ranging from 0.76 to 1.32 were observed in oxygen three-isotope space (δ'{sup 18}O vs. δ'{sup 17}O) which correlated with increasing synchrotron photon energy, and indicate a dependency of the upper electronic state specific dissociation dynamics (e.g., perturbation and coupling associated with a particular state). An unprecedented magnitude in isotope separation was observed for photodissociation at the 105 and 107 nm synchrotron bands and are found to be associated with accidental predissociation of the vibrational states ({nu} = 0 and 1) of the upper electronic state E{sup 1}Π. For each synchrotron band, a large (few hundred per mil) extent of isotopic fractionation was observed and the range of fractionation is a combination of column density and exposure time. A significant temperature dependency in oxygen isotopic fractionation was observed, indicating a rotational level dependency in the predissociation process.

  10. Kaon Electroproduction on Deuterium

    SciTech Connect

    David Abbott; Abdellah Ahmidouch, Pawel Ambrozewicz; Chris Armstrong; John Arrington; K. Assamagan; Kevin Bailey; Oliver K. Baker; Shelton Beedoe; Elizabeth Beise; Herbert Breuer; Roger Carlini; Jinseok Cha; G. Collins; C. Cothran; W.J. Cummings; Samuel Danagoulian; Fraser Duncan; Jim Dunne; Dipangkar Dutta; Tom Eden; Rolf Ent; Lars Ewell; H.T. Fortune; Haiyan Gao; Donald Geesaman; Kenneth Gustafsson; Paul Gueye; Jens-Ole Hansen; Wendy Hinton; Hal Jackson; Cynthia Keppel; Andi Klein; D. Koltenok; David Mack; Richard Madey; Pete Markowitz; C.J. Martoff; David Meekins; Joseph Mitchell; R. Mohring; Hamlet Mkrtchyan; S.K. Mtingwa; Tom O'Neill; Gabriel Niculescu; Ioana Niculescu; Dave Potterveld; John Price; Philip Roos; Brian Raue; J.J. Reidy; Juerg Reinhold; G. Savage; Reyad Sawafta; J.P. Schiffer; Ralph Segel; Stepan Stepanyan; V. Tadevosian; Liguang Tang; B. Terburg; Stephen Wood; Chen Yan; Ben Zeidman; Beni Zihlmann

    1998-08-01

    Kaon electroproduction on deuterium and hydrogen targets has been measured at beam energies of 3.245 and 2.445GeV and momentum transfer Q{sup 2}=0.38 and O.5(GeV/c ){sup 2} Associated production off a proton in the deuteron exhibits a quasifree production mechanism. The electroproduction of a Sigma - off the neutron could be extracted for the first time with reasonable errors.

  11. Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images.

    PubMed

    Larsson, Anne; Johansson, Lennart

    2003-11-21

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  12. Effects of deuterium oxide on cell growth and vesicle speed in RBL-2H3 cells

    PubMed Central

    Triplett, Ashley R.

    2014-01-01

    For the first time we show the effects of deuterium oxide on cell growth and vesicle transport in rat basophilic leukemia (RBL-2H3) cells. RBL-2H3 cells cultured with 15 moles/L deuterium showed decreased cell growth which was attributed to cells not doubling their DNA content. Experimental observations also showed an increase in vesicle speed for cells cultured in deuterium oxide. This increase in vesicle speed was not observed in deuterium oxide cultures treated with a microtubule-destabilizing drug, suggesting that deuterium oxide affects microtubule-dependent vesicle transport. PMID:25237603

  13. Lamb shift in muonic deuterium

    SciTech Connect

    Gorchtein, Mikhail; Vanderhaeghen, Marc; Carlson, Carl E.

    2013-11-07

    We consider the two-photon exchange contribution to the 2P-2S Lamb shift in muonic deuterium in the framework of forward dispersion relations. The dispersion integrals are evaluated with minimal model dependence using experimental data on elastic deuteron form factors and inelastic electron-deuteron scattering, both in the quasielastic and hadronic range. The subtraction constant that is required to ensure convergence of the dispersion relation for the forward Compton amplitude T{sub 1} (ν,Q{sup 2}) is related to the deuteron magnetic polarizability β(Q{sup 2}) and represents the main source of uncertainty in our analysis. We obtain for the Lamb shift ΔE{sub 2P-2S} = 1.620±0.190 meV and discuss ways to further reduce this uncertainty.

  14. Size-dependent geometrically nonlinear free vibration analysis of fractional viscoelastic nanobeams based on the nonlocal elasticity theory

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Faraji Oskouie, M.; Gholami, R.

    2016-01-01

    In recent decades, mathematical modeling and engineering applications of fractional-order calculus have been extensively utilized to provide efficient simulation tools in the field of solid mechanics. In this paper, a nonlinear fractional nonlocal Euler-Bernoulli beam model is established using the concept of fractional derivative and nonlocal elasticity theory to investigate the size-dependent geometrically nonlinear free vibration of fractional viscoelastic nanobeams. The non-classical fractional integro-differential Euler-Bernoulli beam model contains the nonlocal parameter, viscoelasticity coefficient and order of the fractional derivative to interpret the size effect, viscoelastic material and fractional behavior in the nanoscale fractional viscoelastic structures, respectively. In the solution procedure, the Galerkin method is employed to reduce the fractional integro-partial differential governing equation to a fractional ordinary differential equation in the time domain. Afterwards, the predictor-corrector method is used to solve the nonlinear fractional time-dependent equation. Finally, the influences of nonlocal parameter, order of fractional derivative and viscoelasticity coefficient on the nonlinear time response of fractional viscoelastic nanobeams are discussed in detail. Moreover, comparisons are made between the time responses of linear and nonlinear models.

  15. Dynamic Deuterium Enrichment in Cometary Water via Eley–Rideal Reactions

    NASA Astrophysics Data System (ADS)

    Yao, Yunxi; Giapis, Konstantinos P.

    2017-01-01

    The deuterium-to-hydrogen ratio (D/H) in water found in the coma of Jupiter family comet (JFC) 67P/Churyumov–Gerasimenko was reported to be (5.3 ± 0.7) × 10‑4, the highest among comets and three times the value for other JFCs with an ocean-like ratio. This discrepancy suggests the diverse origins of JFCs and clouds the issue of the origin of Earth’s oceanic water. Here we demonstrate that Eley–Rideal reactions between accelerated water ions and deuterated cometary surface analogs can lead to instantaneous deuterium enrichment in water scattered from the surface. The reaction proceeds with H2O+ abstracting adsorbed D atoms, forming an excited H2DO* state, which dissociates subsequently to produce energetic HDO. Hydronium ions are also produced readily by the abstraction of H atoms, consistent with H3O+ detection and abundance in various comets. Experiments with water isotopologs and kinematic analysis on deuterated platinum surfaces confirmed the dynamic abstraction mechanism. The instantaneous fractionation process is independent of the surface temperature and may operate on the surface of cometary nuclei or dust grains, composed of deuterium-rich silicates and carbonaceous chondrites. The requisite energetic water ions have been detected in the coma of 67P in two populations. This dynamic fractionation process may temporarily increase the water D/H ratio, especially as the comet gets closer to the Sun. The magnitude of the effect depends on the water ion energy-flux and the deuterium content of the exposed cometary surfaces.

  16. Oxygen and sulfur isotope fractionation during methane dependent sulfate reduction in high pressure continuous incubation studies

    NASA Astrophysics Data System (ADS)

    Deusner, C.; Brunner, B.; Holler, T.; Widdel, F.; Ferdelman, T. G.

    2009-12-01

    The anaerobic oxidation of methane (AOM) coupled to sulfate reduction in marine sediments is an important sink in the global methane budget. However, many aspects of methane dependent sulfate reduction are not fully understood. We developed a novel high pressure biotechnical system to simulate marine conditions with high concentrations of dissolved gases, e.g. at gas seeps and gas hydrate systems. The system allows for batch, fed-batch and continuous gas-phase free incubation. We employ this system to study the kinetics and isotope fractionation during AOM at varying methane partial pressures up to 10 MPa. We present the results of long-term continuous and fed-batch incubations with highly active naturally enriched biomass from microbial mats from the Black Sea. During these experiments the methane partial pressure was increased stepwise from 0.1 to 10 MPa. The methane dependent sulfate reduction rate increased from 0.1 mmol/l/d to 3.5 mmol/l/d resulting from the increase in methane concentration and microbial growth. Sulfate reduction was negligible in the absence of methane. The sulfur and oxygen isotope fractionation during sulfate reduction was strongly influenced by the concentration of dissolved methane. Sulfur isotope fractionation was highest at low methane concentrations, and lowest at high methane concentrations. Relative to sulfate reduction rates, oxygen isotope exchange between sulfate and water was highest at low methane concentrations, and lowest at high methane concentrations.

  17. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide.

    USDA-ARS?s Scientific Manuscript database

    We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of gluc...

  18. Load-dependent destabilization of the γ-rotor shaft in FOF1 ATP synthase revealed by hydrogen/deuterium-exchange mass spectrometry

    PubMed Central

    Vahidi, Siavash; Bi, Yumin; Dunn, Stanley D.; Konermann, Lars

    2016-01-01

    FoF1 is a membrane-bound molecular motor that uses proton-motive force (PMF) to drive the synthesis of ATP from ADP and Pi. Reverse operation generates PMF via ATP hydrolysis. Catalysis in either direction involves rotation of the γε shaft that connects the α3β3 head and the membrane-anchored cn ring. X-ray crystallography and other techniques have provided insights into the structure and function of FoF1 subcomplexes. However, interrogating the conformational dynamics of intact membrane-bound FoF1 during rotational catalysis has proven to be difficult. Here, we use hydrogen/deuterium exchange mass spectrometry to probe the inner workings of FoF1 in its natural membrane-bound state. A pronounced destabilization of the γ C-terminal helix during hydrolysis-driven rotation was observed. This behavior is attributed to torsional stress in γ, arising from γ⋅⋅⋅α3β3 interactions that cause resistance during γ rotation within the apical bearing. Intriguingly, we find that destabilization of γ occurs only when FoF1 operates against a PMF-induced torque; the effect disappears when PMF is eliminated by an uncoupler. This behavior resembles the properties of automotive engines, where bearings inflict greater forces on the crankshaft when operated under load than during idling. PMID:26884184

  19. THE ENVIRONMENTAL DEPENDENCE OF THE FRACTION OF 'UNCONVENTIONAL' GALAXIES: RED LATE TYPES AND BLUE EARLY TYPES

    SciTech Connect

    Deng Xinfa; He Jizhou; Wu Ping; Ding Yingping

    2009-07-10

    From the Main galaxy sample of the Sloan Digital Sky Survey Data Release 6, we construct two volume-limited samples with the luminosity -20.0 {<=} M{sub r} {<=} -18.5 and -22.40 {<=} M{sub r} {<=} -20.16, respectively, to explore the environmental dependence of the fraction of 'unconventional' galaxies: red late types and blue early types. We use the density estimator within the distance to the fifth nearest neighbor, and construct two samples at both extremes of density and perform comparative studies between them for each volume-limited sample. Results of two volume-limited samples show the same conclusions: the fraction of red late-type galaxies rises considerably with increasing local density, and that one of the blue early-type galaxies declines substantially with increasing local density. In addition, we note that bluer galaxies preferentially are late types, but the red galaxies are not dominated by early types.

  20. Presence of a voltage-dependent anion channel 1 in the rat postsynaptic density fraction.

    PubMed

    Moon, J I; Jung, Y W; Ko, B H; De Pinto, V; Jin, I; Moon, I S

    1999-02-25

    Little is known about the molecular organization and functions of the postsynaptic density (PSD), a cytoskeletal specialization on the postsynaptic membrane. In an attempt to elucidate the protein composition of PSD, we have sequenced a 35 kDa protein of the rat forebrain PSD fraction. Amino acid sequence information of the tryptic peptides and immunoblot analyses revealed that the protein is a voltage-dependent anion channel 1 (VDAC1). VDAC1 was enriched in the PSD fraction and was partially soluble in 1% n-octyl glucoside (NOG) or Triton X-100. Our data indicate that VDAC1, which is originally found in the outer mitochondrial membrane, is also present in the central nervous system (CNS) synapses in association with the PSD 'core'.

  1. Reporting and measurement of mass-dependent and mass-independent fractionation of mercury isotopes

    NASA Astrophysics Data System (ADS)

    Bergquist, B. A.; Blum, J. D.

    2007-12-01

    Hg isotope analysis by MC-ICP-MS is an important new approach for fingerprinting Hg sources and monitoring Hg redox reactions and bioaccumulation, especially with the recent discovery of mass independent Hg isotope fractionation. Unfortunately research groups have adopted different standards, definitions of delta values, and methods of isotopic measurement. We suggest that a single standard, NIST SRM 3133, be adopted for reporting the isotopic variability of Hg isotopes. Isotope ratios should be determined by sample-standard bracketing (SSB) during analysis and reported as permil (‰) deviation from SRM 3133. For the highest precision and accuracy, a Tl internal standard along with SSB should be used to correct instrumental mass bias. Measurement routines should also include on-peak zero corrections and matching of concentration and matrix between the samples and bracketing standard. For samples that display mass-dependent fractionation (MDF), only one delta value needs to be reported (δ202/198Hg). Mass-independent fractionation (MIF) (Jackson et al., 2006; Bergquist et al., 2006; Bergquist and Blum, submitted) requires additional nomenclature, and we suggest reporting MIF as the deviation in isotope ratios from the theoretical mass dependent kinetic isotope fractionation (Δxxx/198Hg)¬. External reproducibility should be monitored by analysis of secondary standards. For studies of MDF, we use an in-house secondary standard solution made from metallic Hg mined from Almaden Spain and obtain a δ202Hg of -0.55 ±0.06‰ (2SD). For studies of MIF, we use NRCC CRM DORM-2 (dogfish muscle) and obtain a mean value of δ202Hg of +0.19 ±0.13‰ (2SD), Δ201Hg of +0.89 ±0.07‰ (2SD) , and Δ199Hg of +1.07 ±0.08‰ (2SD).

  2. Deuterium retention in tungsten exposed to low-energy pure and helium-seeded deuterium plasmas

    NASA Astrophysics Data System (ADS)

    Ogorodnikova, O. V.; Schwarz-Selinger, T.; Sugiyama, K.; Alimov, V. Kh.

    2011-01-01

    Influence of helium (He) on the deuterium (D) retention in tungsten (W) under simultaneous He-D plasma exposure was investigated. Bulk polycrystalline tungsten and two W coatings on carbon substrate, namely, plasma-sprayed tungsten and combined magnetron-sputtered and ion implanted tungsten (CMSII-W) were exposed to pure and He-seeded D plasmas generated by electron-cyclotron-resonance plasma source. The D retention in each sample was subsequently analyzed by various methods such as nuclear reaction analysis for the D depth profiling up to 6 μm and thermal desorption spectroscopy for the determination of total amount of D retention. It is shown that seeding of helium into D plasma with helium ion flux fraction of 10% reduces the deuterium retention for all tungsten grades but more significant reduction was observed for polycrystalline W and less significant effect was found for W coatings. From the thermal desorption spectroscopy measurements, we conclude that the presence of He modifies the density of existing traps for D but does not modify the nature of traps. Maximum effect of a reduction in the deuterium retention due to helium seeding was observed at around 500 K for bulk polycrystalline W. Mechanisms of deuterium retention and He effect in different W materials are discussed.

  3. Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K

    NASA Astrophysics Data System (ADS)

    Morozov, Oleksandr; Zhurba, Volodymyr; Neklyudov, Ivan; Mats, Oleksandr; Rud, Aleksandr; Chernyak, Nikolay; Progolaieva, Viktoria

    2015-03-01

    Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 1015 to 5 × 1018 D/cm2. The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.

  4. ORIGINS OF NON-MASS-DEPENDENT FRACTIONATION OF EXTRA-TERRESTRIAL OXYGEN

    SciTech Connect

    Barcena, Homar; Connolly, Harold C.

    2012-08-01

    The distribution of oxygen isotopes in meteorites and within the earliest solids that formed in the solar system hints that the precursors of these materials must have undergone a mass-independent process. The mass-independent process is specifically one that fractionates {sup 16}O from {sup 17}O and {sup 18}O. This chemical signature is indicative of non-equilibrium processing, which bear resemblance to some unusual terrestrial phenomenon such as fractionation of ozone in the upper Earth atmosphere. That the mass-independent fractionation of oxygen isotopes is preserved within petrological records presents planetary scientists interesting clues to the events that may have occurred during the formation of the solar system. Currently, there are several hypotheses on the origins of the oxygen isotope distribution within primitive planetary materials, which include both thermal and photochemical models. We present a new model based on a physico-chemical hypothesis for the origin of non-mass-dependent O-isotope distribution in oxygen-bearing extra-terrestrial materials, which originated from the disproportionation of CO in dark molecular clouds to create CO{sub 2} reservoirs. The disproportionation created a reservoir of heavy oxygen isotopes and could have occurred throughout the evolution of the disk. The CO{sub 2} was a carrier of the isotope anomaly in the solar nebula and we propose that non-steady-state mixing of these reservoirs with the early rock-forming materials during their formation corresponds with the birth and evolution of the solar system.

  5. CO2-dependent carbon isotope fractionation in the dinoflagellate Alexandrium tamarense

    NASA Astrophysics Data System (ADS)

    Wilkes, Elise B.; Carter, Susan J.; Pearson, Ann

    2017-09-01

    The carbon isotopic composition of marine sedimentary organic matter is used to resolve long-term histories of pCO2 based on studies indicating a CO2-dependence of photosynthetic carbon isotope fractionation (εP). It recently was proposed that the δ13C values of dinoflagellates, as recorded in fossil dinocysts, might be used as a proxy for pCO2. However, significant questions remain regarding carbon isotope fractionation in dinoflagellates and how such fractionation may impact sedimentary records throughout the Phanerozoic. Here we investigate εP as a function of CO2 concentration and growth rate in the dinoflagellate Alexandrium tamarense. Experiments were conducted in nitrate-limited chemostat cultures. Values of εP were measured on cells having growth rates (μ) of 0.14-0.35 d-1 and aqueous carbon dioxide concentrations of 10.2-63 μmol kg-1 and were found to correlate linearly with μ/[CO2(aq)] (r2 = 0.94) in accord with prior, analogous chemostat investigations with eukaryotic phytoplankton. A maximum fractionation (εf) value of 27‰ was characterized from the intercept of the experiments, representing the first value of εf determined for an algal species employing Form II RubisCO-a structurally and catalytically distinct form of the carbon-fixing enzyme. This value is larger than theoretical predictions for Form II RubisCO and not significantly different from the ∼25‰ εf values observed for taxa employing Form ID RubisCO. We also measured the carbon isotope contents of dinosterol, hexadecanoic acid, and phytol from each experiment, finding that each class of biomarker exhibits different isotopic behavior. The apparent CO2-dependence of εP values in our experiments strengthens the proposal to use dinocyst δ13C values as a pCO2 proxy. Moreover, the similarity between the εf value for A. tamarense and the consensus value of ∼25‰ indicates that the CO2-sensitivity of carbon isotope fractionation saturates at similar CO2 levels across all three

  6. Physicochemical Processes on Ice Dust Towards Deuterium Enrichment

    NASA Astrophysics Data System (ADS)

    Watanabe, Naoki

    2017-06-01

    Water and some organic molecules were found to be deuterium enriched toward various astronomical targets. Understanding the deuterium-fractionation process pertains directly to know how and when molecules are created. Although gas phase chemistry is certainly important for deuterium enrichment, the role of physicochemical processes on the dust surfaces should be also considered. In fact, the extreme deuterium enrichment of formaldehyde and methanol requires the dust grain-surface process. In this context, we have performed a series of experiments on the formation of deuterated species of water and simple organic molecules. From the results of these experiments and related works, I will discuss the key processes for the deuterium enrichment on dust. For deuterium chemistry, another important issue is the ortho-to-para ratio (OPR) of H_{2}, which is closely related to the formation of H_{2}D^{+} and thus the deuterium fractionation of molecules in the gas phase. Because the radiative nuclear spin conversion of H_{2} is forbidden, the ortho-para conversion is very slow in the gas phase. In contrast, it was not obvious how the nuclear spins behave on cosmic dust. Therefore, it is desirable to understand how the OPR of H_{2} is determined on the dust surfaces. We have tackled this issue experimentally. Using experimental techniques of molecular beam, photostimulated-desorption, and resonance-enhanced multiphoton ionization, we measured the OPRs of H_{2} photodesorbed from amorphous solid water at around 10 K, which is an ice dust analogue. It was first demonstrated that the rate of spin conversion from ortho to para drastically increases from 2.4 × 10^{-4} to 1.7 × 10^{-3} s^{-1} within the very narrow temperature window of 9.2 to16 K. The observed strong temperature cannot be explained by solely state-mixing models ever proposed but by the energy dissipation model via two phonon process. I will present our recent experiments regarding this.

  7. Inelastic dark matter with spin-dependent couplings to protons and large modulation fractions in DAMA

    SciTech Connect

    Scopel, Stefano; Yoon, Kook-Hyun E-mail: koreasds@naver.com

    2016-02-01

    We discuss a scenario where the DAMA modulation effect is explained by a Weakly Interacting Massive Particle (WIMP) which upscatters inelastically to a heavier state and predominantly couples to the spin of protons. In this scenario constraints from xenon and germanium targets are evaded dynamically, due to the suppression of the WIMP coupling to neutrons, while those from fluorine targets are evaded kinematically, because the minimal WIMP incoming speed required to trigger upscatters off fluorine exceeds the maximal WIMP velocity in the Galaxy, or is very close to it. In this scenario WIMP scatterings off sodium are usually sensitive to the large-speed tail of the WIMP velocity distribution and modulated fractions of the signal close to unity arise in a natural way. On the other hand, a halo-independent analysis with more conservative assumptions about the WIMP velocity distribution allows to extend the viable parameter space to configurations where large modulated fractions are not strictly necessary. We discuss large modulated fractions in the Maxwellian case showing that they imply a departure from the usual cosine time dependence of the expected signal in DAMA. However we explicitly show that the DAMA data is not sensitive to this distortion, both in time and frequency space, even in the extreme case of a 100 % modulated fraction. Moreover the same scenario provides an explanation of the maximum in the energy spectrum of the modulation amplitude detected by DAMA in terms of WIMPs whose minimal incoming speed matches the kinematic threshold for inelastic upscatters. For the elastic case the detection of such maximum suggests an inversion of the modulation phase below the present DAMA energy threshold, while this is not expected for inelastic scattering. This may allow to discriminate between the two scenarios in a future low-threshold analysis of the DAMA data.

  8. Release of the phosphodiesterase activator by cyclic AMP-dependent ATP:protein phosphotransferase from subcellular fractions of rat brain.

    PubMed

    Gnegy, M E; Nathanson, J A; Uzunov, P

    1977-03-29

    The subcellular distribution of the endogenous phosphodiesterase activator and its release from membranes by a cyclic AMP-dependent ATP:protein phosphotransferase was studied in fractions and subfractions of rat brain homogenate. These fractions were obtained by differential centrifugation and sucrose density gradient; their identity was ascertained by electron microscopy and specific enzyme markers. In the subcellular particulate fractions, the concentration of activator is highest in the microsomal fraction, followed by the mitochondrial and nuclear fractions. Gradient centrifugation of the main mitochondrial subfraction revealed that activator was concentrated in those fractions containing mainly synaptic membranes. Activator was releasted from membranes by a cyclic AMP-dependent phosphorylation of membrane protein. The release of activator occurred mainly from the mitochondrial subfractions containing synaptic membranes and synaptic vesicles. The data support the view that a release of activator from membranes may be important in normalizing the elevated concentration of cyclic AMP following persistent transsynaptic activation of adenylate cyclase.

  9. Resonant spin-flavor conversion of supernova neutrinos: Dependence on electron mole fraction

    SciTech Connect

    Yoshida, Takashi; Takamura, Akira; Kimura, Keiichi; Yokomakura, Hidekazu; Kawagoe, Shio; Kajino, Toshitaka

    2009-12-15

    Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Y{sub e} is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds 0.5 in several seconds after the core collapse. When a higher resonance of the RSF conversion is located in the innermost region, flavor change of the neutrinos strongly depends on the sign of 1-2Y{sub e}. At an adiabatic high RSF resonance the flavor conversion of {nu}{sub e}{r_reversible}{nu}{sub {mu}}{sub ,{tau}} occurs in Y{sub e}<0.5 and normal mass hierarchy or in Y{sub e}>0.5 and inverted mass hierarchy. In other cases of Y{sub e} values and mass hierarchies, the conversion of {nu}{sub e}{r_reversible}{nu}{sub {mu}}{sub ,{tau}} occurs. The final {nu}{sub e} spectrum is evaluated in the cases of Y{sub e}<0.5 and Y{sub e}>0.5 taking account of the RSF conversion. Based on the obtained result, time variation of the event number ratios of low {nu}{sub e} energy to high {nu}{sub e} energy is discussed. In normal mass hierarchy, an enhancement of the event ratio should be seen in the period when the electron fraction in the innermost region exceeds 0.5. In inverted mass hierarchy, on the other hand, a dip of the event ratio should be observed. Therefore, the time variation of the event number ratio is useful to investigate the effect of the RSF conversion.

  10. CO2-dependent carbon isotope fractionation in dinoflagellates relates to their inorganic carbon fluxes.

    PubMed

    Hoins, Mirja; Eberlein, Tim; Van de Waal, Dedmer B; Sluijs, Appy; Reichart, Gert-Jan; Rost, Björn

    2016-08-01

    Carbon isotope fractionation (εp) between the inorganic carbon source and organic matter has been proposed to be a function of pCO2. To understand the CO2-dependency of εp and species-specific differences therein, inorganic carbon fluxes in the four dinoflagellate species Alexandrium fundyense, Scrippsiella trochoidea, Gonyaulax spinifera and Protoceratium reticulatum have been measured by means of membrane-inlet mass spectrometry. In-vivo assays were carried out at different CO2 concentrations, representing a range of pCO2 from 180 to 1200 μatm. The relative bicarbonate contribution (i.e. the ratio of bicarbonate uptake to total inorganic carbon uptake) and leakage (i.e. the ratio of CO2 efflux to total inorganic carbon uptake) varied from 0.2 to 0.5 and 0.4 to 0.7, respectively, and differed significantly between species. These ratios were fed into a single-compartment model, and εp values were calculated and compared to carbon isotope fractionation measured under the same conditions. For all investigated species, modeled and measured εp values were comparable (A. fundyense, S. trochoidea, P. reticulatum) and/or showed similar trends with pCO2 (A. fundyense, G. spinifera, P. reticulatum). Offsets are attributed to biases in inorganic flux measurements, an overestimated fractionation factor for the CO2-fixing enzyme RubisCO, or the fact that intracellular inorganic carbon fluxes were not taken into account in the model. This study demonstrates that CO2-dependency in εp can largely be explained by the inorganic carbon fluxes of the individual dinoflagellates.

  11. Fractional Viscosity Dependence of Reaction Kinetics in Glass-Forming Liquids

    NASA Astrophysics Data System (ADS)

    Kwon, Seulki; Cho, Hyun Woo; Kim, Jeongmin; Sung, Bong June

    2017-08-01

    The diffusion of molecules in complex systems such as glasses and cell cytoplasm is slow, heterogeneous, and sometimes nonergodic. The effects of such intriguing diffusion on the kinetics of chemical and biological reactions remain elusive. In this Letter, we report that the kinetics of the polymer loop formation reaction in a Kob-Andersen (KA) glass forming liquid is influenced significantly by the dynamic heterogeneity. The diffusion coefficient D of a KA liquid deviates from the Stokes-Einstein relation at low temperatures and D shows a fractional dependence on the solvent viscosity ηs, i.e., D ˜ηs-ξD with ξD=0.85 . The dynamic heterogeneity of a KA liquid affects the rate constant krxn of the loop formation and leads to the identical fractional dependence of krxn on ηs with krxn˜ηs-ξ and ξ =ξD, contrary to reactions in dynamically homogeneous solutions where krxn˜ηs-1.

  12. Time-dependent fractional dynamics with memory in quantum and economic physics

    NASA Astrophysics Data System (ADS)

    Tarasov, Vasily E.; Tarasova, Valentina V.

    2017-08-01

    Fractional dynamics of open quantum systems and sectors of national economies, where the parameters depend on time, are discussed. We show that the quantum and economic processes can demonstrate the same dynamic behavior caused by effects of power-law fading memory. In this paper, we propose generalizations of time-ordered exponential (T-exponential) and time-ordered product (T-product) for processes with power-lawmemory. The expressions of time-ordered exponential with memory and corresponding generalization time-ordered product are derived by using matrix fractional differential equations. In quantum physics, we consider equations of N-level open quantum system with memory, quantum oscillator with friction and memory. In economic physics (econophysics), we use equations of dynamic intersectoral model with power-law memory, where the matrix of direct material costs and the matrix of incremental capital intensity of production depend on time. The solutions of these equations with derivatives of non-integer orders are suggested.

  13. Non-mass-dependent fractionation of sulfur and oxygen isotopes during UV photolysis of sulfur dioxide

    NASA Astrophysics Data System (ADS)

    Pen, Aranh

    Since the discovery of anomalous sulfur isotope abundance in the geological record in sulfate and sulfide minerals (Farquhar et al., 2000), much effort has been put into understanding their origin to provide new insights into the environmental conditions on the early Earth (Farquhar et al., 2001; Pavlov and Kasting, 2002; Ono et al., 2003; Zahnle et al., 2006; Farquhar et al., 2007; Lyons, 2007; Lyons, 2008). This discovery gained immense interest because of its implications for both the lack of oxygen in the atmosphere during the Archean era 2.5-3.8 Gya (billion years ago), and for rise of oxygen, or the "Great Oxidation Event", that occurred 2.2-2.4 Gya (Holland, 2002). These signatures are believed to be produced in an anticorrelation to oxygen abundance in the early atmosphere, which will aid in quantifying the rate of oxygenation during the "Great Oxidation Event". According to Farquhar et al. (2000), the non-mass-dependent (NMD), or anomalous, fractionation signatures were produced by photochemical reactions of volcanic sulfur species in Earth's early atmosphere (> 2.3 Gya) due to the lack of an oxygen and ozone shield, resulting in an atmosphere transparent to solar ultraviolet (UV) radiation (Farquhar et al., 2001). Interpretation of the anomalous rock records, though, depends on the identification of (1) chemical reactions that can produce the NMD signature (Farquhar and Wing, 2003); and (2) conditions necessary for conversion of the gas-phase products into solid minerals (Pavlov and Kasting, 2002). The focus of my research addresses the first step, which is to determine whether the chemical reactions that occurred in Earth's early atmosphere, resulting in NMD fractionation of sulfur isotopes, were due to broadband UV photochemistry, and to test isotopic self-shielding as the possible underlying mechanism. In this project, our goals were to test isotopic self-shielding during UV photolysis as a possible underlying mechanism for anomalous sulfur isotopic

  14. Human Renovascular Disease: Estimating Fractional Tissue Hypoxia to Analyze Blood Oxygen Level–dependent MR

    PubMed Central

    Saad, Ahmed; Crane, John; Glockner, James F.; Herrmann, Sandra M. S.; Friedman, Hannah; Ebrahimi, Behzad; Lerman, Lilach O.

    2013-01-01

    Purpose: To test the hypothesis that fractional kidney hypoxia, measured by using blood oxygen level–dependent (BOLD) magnetic resonance (MR) imaging, correlates with renal blood flow (RBF), tissue perfusion, and glomerular filtration rate (GFR) in patients with atherosclerotic renal artery stenosis (RAS) better than regionally selected region of interest–based methods. Materials and Methods: The study was approved by the institutional review board according to a HIPAA-compliant protocol, with written informed consent. BOLD MR imaging was performed in 40 patients with atherosclerotic RAS (age range, 51–83 years; 22 men, 18 women) and 32 patients with essential hypertension (EH) (age range, 26–85 years; 19 men, 13 women) during sodium intake and renin-angiotensin blockade. Fractional kidney hypoxia (percentage of entire axial image section with R2* above 30 sec−1) and conventional regional estimates of cortical and medullary R2* levels were measured. Stenotic and nonstenotic contralateral kidneys were compared for volume, tissue perfusion, and blood flow measured with multidetector computed tomography. Statistical analysis was performed (paired and nonpaired t tests, linear regression analysis). Results: Stenotic RBF was reduced compared with RBF of contralateral kidneys (225.2 mL/min vs 348 mL/min, P = .0003). Medullary perfusion in atherosclerotic RAS patients was lower than in EH patients (1.07 mL/min per milliliter of tissue vs 1.3 mL/min per milliliter of tissue, P = .009). While observer-selected cortical R2* (18.9 sec−1 [stenosis] vs 18.5 sec−1 [EH], P = .07) did not differ, fractional kidney hypoxia was higher in stenotic kidneys compared with kidneys with EH (17.4% vs 9.6%, P < .0001) and contralateral kidneys (7.2%, P < .0001). Fractional hypoxia correlated inversely with blood flow (r = −0.34), perfusion (r = −0.3), and GFR (r = −0.32). Conclusion: Fractional tissue hypoxia rather than cortical or medullary R2* values used to assess

  15. Growth-dependent hydrogen isotopic fractionation of algal lipid biomarkers in hypersaline Isabel Lake (México)

    NASA Astrophysics Data System (ADS)

    Romero-Viana, Lidia; Kienel, Ulrike; Wilkes, Heinz; Sachse, Dirk

    2013-04-01

    In this study, we evaluated the potential of the hydrogen isotopic composition of algal lipid biomarkers as a proxy for past hydroclimatic variability in hypersaline Isabel Lake, Mexico (Eastern Pacific). We compared rainfall variability recorded in the region over the last 65 years with changes in δD values of the most abundant compounds preserved in the uppermost 16 cm of lake sediment. Changes in δD values of the 1,15-C32 diol (δDdiol), a specific biomarker of algal populations, were related to rainfall variability; specifically, n-alkyl diols were more deuterium-enriched (depleted) during wetter (drier) periods. Strikingly, neither the magnitude of lipid biomarker isotopic changes over interannual timescales (of up to 70-80‰) nor the direction of that variability can be explained by changes in δD values of the water source or salinity fluctuations (approximately 30 on the practical salinity scale) controlled by seasonal rainfall. However, changes in sedimentary biomarker composition, higher total organic carbon content and less negative δ13C values of the 1,15-C32 diol indicate enhanced algal growth during wetter periods. We find that these conditions result in less negative δD values of n-alkyl diols. We hypothesize that due to higher lipid demand during enhanced algal growth, an increasing proportion of hydrogen for lipid synthesis is derived from the cytosol via oxidation of polysaccharides, which may cause a deuterium enrichment of the acetogenic compounds. This study has significant implications for paleohydrological reconstructions using algal lipid δD values, particularly in highly seasonal environments such as Isabel Lake. In such environments, δD values of specific algal lipid biomarkers may not record the full seasonal cycle in source water δD but appear to be mainly controlled by the physiological state of algal populations. Our data provide the first evidence that changes in D/H fractionation due to algal growth conditions can be recorded

  16. Dialysis experiments for assessing the pH-dependent sorption of sulfonamides to soil clay fractions.

    PubMed

    Anskjær, G G; Krogh, K A; Halling-Sørensen, B

    2014-01-01

    Equilibrium dialysis experiments, a novel approach for conducting soil/water distribution experiments in environmental samples, were found to be applicable for assessing pH-dependent partitioning and to quantify the sorption of three sulfonamides, sulfadiazine, sulfadoxine, and sulfacetamide. Clay fractions from two agricultural soils including both particulate and dissolved soil matter were used in the experiments to achieve a high sorption capacity when varying pH in a relevant environmental range. Stabilizing and controlling pH was done by using organic buffers. In two clay fractions, Kd for sulfadiazine was determined to be 43 and 129 L kg(-1), and 1.3 and 4.6 L kg(-1) at pH 4.0 and pH 9.0, respectively. This corresponded to Kd for the neutral and ionized form of sulfadiazine, respectively. The difference in sulfadiazine sorption between the two clay fractions could to some extent be related to the difference in the amount of organic carbon. Sorption experiments with sulfacetamide and sulfadoxine also exhibited decreasing sorption when increasing pH. At low pH, maximum Kd for sulfacetamide and sulfadoxine was determined to be 83 and 211 L kg(-1), respectively, while at high pH minimum Kd was 4.8 and 1.2 L kg(-1), respectively. Hence, compound speciation was important for the quantity of sorbed sulfonamide, which was confirmed by a correlation (R(2)) close to unity, when using the experimentally obtained Kd values with a simple model weighing the contribution from the neutral and the ionized compound, respectively.

  17. Primary ion dependence of LiF direct recoil intensities and ion fractions

    NASA Astrophysics Data System (ADS)

    Chen, J. N.; Shi, M.; Rabalais, J. W.

    1987-02-01

    Time-of-flight (TOF) spectra of the scattered and recoiled particles resulting from 1-10 keV He+, Ne+, Ar+, Kr+, and Xe+ ions impingent on surfaces of LiF thin films have been obtained. Measurements of directly recoiled (DR) neutrals plus ions and neutrals alone are used to calculate positive and negative ion fractions Y+,- from DR events. The oppositely charged ion fractions have a distinctly different behavior as a function of kinetic energy. The Y+ values exhibit a threshold at low energy followed by a plateau region at higher energy while the Y- values are maximum in the low energy region followed by a decreasing yield as energy increases. The energy dependence of Y+,- is interpreted in terms of the recently developed model [J. Chem. Phys. 85, 3615 (1986)] for electronic charge exchange in keV ion/surface collisions which considers electron promotions in the close atomic encounter and resonant and Auger transitions along the outgoing trajectory. The ionization potential of the primary ion relative to the energy levels of the target atom is shown to have a large influence on charge exchange in the close encounter. The ratio of direct recoil to scattering particle flux increases by a factor of >102 from He to Xe; scattering and recoil cross sections are used to model this process.

  18. Time-dependence of sea-ice concentration and multiyear ice fraction in the Arctic Basin

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Zwally, H. J.; Chang, A. T. C.; Hall, D. K.; Campbell, W. J.; Ramseier, R. O.

    1978-01-01

    Microwave images of sea ice obtained by Nimbus-5 and the NASA CV-990 airborne laboratory are used to determine the time variation of the sea-ice concentration and multiyear ice fraction within the pack ice in the Arctic Basin. The images, constructed from data acquired from the electrically scanned microwave radiometer, are analyzed for four seasons during 1973-1975. Observations indicate significant variations in the sea-ice concentration in the spring, late fall, and early winter. Sea-ice concentrations as low as 50% were detected in large areas in the interior of the Arctic polar sea-ice pack. The applicability of passive-microwave remote sensing for monitoring the time dependence of sea-ice concentration is considered.

  19. Frequency dependent piecewise fractional-order modelling of ultracapacitors using hybrid optimization and fuzzy clustering

    NASA Astrophysics Data System (ADS)

    Kumar, Mano Ranjan; Ghosh, Subhojit; Das, Shantanu

    2016-12-01

    The usage of ultracapacitors for development of energy storage devices and alternative power sources is increasing at a very rapid rate. However accuracy in selection of ultracapacitor model parameter plays key role in the design of such devices, especially in applications involving wide operating frequency. Ultracapacitors are known to exhibit fractional dynamics and the model parameters vary significantly with frequency. This paper proposes a piecewise modelling and parameter estimation approach for ultracapacitors using a hybrid optimization and fuzzy clustering approach. The proposed modelling technique has been applied over impedance frequency response data acquired from a commercially available ultracapacitor. The model is able to represent the experimental data over different operating points with reduced number of model parameters. Comparative numerical simulations have been carried out to validate the benefits of the proposed approach. The estimated parameters revealed the disparity in the frequency dependent behavior of ultracapacitors and standard electrolytic capacitors.

  20. Deuterium implantation into Y2O3-doped and pure tungsten: Deuterium retention and blistering behavior

    NASA Astrophysics Data System (ADS)

    Zhao, M.; Jacob, W.; Manhard, A.; Gao, L.; Balden, M.; von Toussaint, U.; Zhou, Z.

    2017-04-01

    The blistering and near-surface deuterium retention of a Y2O3-doped tungsten (W) and two different pure W grades were studied after exposure to deuterium (D) plasma at elevated temperatures (370, 450 and 570 K). Samples were exposed to a deuterium fluence of 6 × 1024 D m-2 applying a moderate ion flux of about 9 × 1019 D m-2 s-1 at an ion energy of 38 eV/D. Morphological modifications at the surface were analyzed by confocal laser scanning microscopy and scanning electron microscopy. The D depth profiles and the accumulated D inventories within the topmost 8 μm were determined by nuclear reaction analysis. Blistering and deuterium retention were strongly dependent on the implantation temperature. In addition, blistering was sensitively influenced by the used tungsten grade, although the total amount of retained D measured by nuclear reaction analysis was comparable. Among the three different investigated tungsten grades, Y2O3-doped W exhibited the lowest degree of surface modification despite a comparable total D retention.

  1. Shock compression of precompressed deuterium

    SciTech Connect

    Armstrong, M R; Crowhurst, J C; Zaug, J M; Bastea, S; Goncharov, A F; Militzer, B

    2011-07-31

    Here we report quasi-isentropic dynamic compression and thermodynamic characterization of solid, precompressed deuterium over an ultrafast time scale (< 100 ps) and a microscopic length scale (< 1 {micro}m). We further report a fast transition in shock wave compressed solid deuterium that is consistent with the ramp to shock transition, with a time scale of less than 10 ps. These results suggest that high-density dynamic compression of hydrogen may be possible on microscopic length scales.

  2. Deuterium Enrichment of PAHs by VUV Irradiation of Interstellar Ices

    NASA Technical Reports Server (NTRS)

    Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.; Gillette, J. Seb; Zare, Richard N.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    Laboratory results demonstrate that polycyclic aromatic hydrocarbons (PAHs) rapidly exchange their hydrogen atoms with those of nearby molecules when they are frozen into low-temperature ices and exposed to vacuum ultraviolet radiation. As a result, PAHs quickly become deuterium-enriched when VUV irradiated in D-containing ices. This mechanism has important consequences for several astrophysical issues owing to the ubiquitous nature of PAHs in the interstellar medium. For example, this process may explain the deuterium enrichments found in PAHs in meteorites and interplanetary dust particles. These results also provide general predictions about the molecular siting of the deuterium on aromatic materials in meteorites if this process produced a significant fraction of their D-enrichment.

  3. Laser-driven polarized hydrogen and deuterium internal targets

    SciTech Connect

    Jones, C.E.; Fedchak, J.A.; Kowalczyk, R.S.

    1995-08-01

    After completing comprehensive tests of the performance of the source with both hydrogen and deuterium gas, we began tests of a realistic polarized deuterium internal target. These tests involve characterizing the atomic polarization and dissociation fraction of atoms in a storage cell as a function of flow and magnetic field, and making direct measurements of the average nuclear tensor polarization of deuterium atoms in the storage cell. Transfer of polarization from the atomic electron to the nucleus as a result of D-D spin-exchange collisions was observed in deuterium, verifying calculations suggesting that high vector polarization in both hydrogen and deuterium can be obtained in a gas in spin temperature equilibrium without inducing RF transitions between the magnetic substates. In order to improve the durability of the system, the source glassware was redesigned to simplify construction and installation and eliminate stress points that led to frequent breakage. Improvements made to the nuclear polarimeter, which used the low energy {sup 3}H(d,n){sup 4}He reaction to analyze the tensor polarization of the deuterium, included installing acceleration lenses constructed of wire mesh to improve pumping conductance, construction of a new holding field coil, and elimination of the Wien filter from the setup. These changes substantially simplified operation of the polarimeter and should have reduced depolarization in collisions with the wall. However, when a number of tests failed to show an improvement of the nuclear polarization, it was discovered that extended operation of the system with a section of teflon as a getter for potassium caused the dissociation fraction to decline with time under realistic operating conditions, suggesting that teflon may not be a suitable material to eliminate potassium from the target. We are replacing the teflon surfaces with drifilm-coated ones and plan to continue tests of the polarized internal target in this configuration.

  4. Influence of Deuterium Treatments on the Polysilicon-Based Metal-Semiconductor-Metal Photodetector.

    PubMed

    Lee, Jae-Sung

    2016-06-01

    The electrical behavior of metal-semiconductor-metal (MSM) Schottky barrier photodetector structure, depending on deuterium treatment, is analyzed by means of the dark current and the photocurrent measurements. Al/Ti bilayer was used as Schottky metal. The deuterium incorporation into the absorption layer, undoped polysilicon, was achieved with annealing process and with ion implantation process, respectively. In the photocurrent-to-dark current ratio measurement, deuterium-ion-implanted photodetector shows over hundred higher than the control device. It means that the heightening of the Schottky barrier and the passivation of grain boundary trap were achieved effectively through the deuterium ion implantation process.

  5. Fractional Laplacian time-space models for linear and nonlinear lossy media exhibiting arbitrary frequency power-law dependency.

    PubMed

    Chen, W; Holm, S

    2004-04-01

    Frequency-dependent attenuation typically obeys an empirical power law with an exponent ranging from 0 to 2. The standard time-domain partial differential equation models can describe merely two extreme cases of frequency-independent and frequency-squared dependent attenuations. The otherwise nonzero and nonsquare frequency dependency occurring in many cases of practical interest is thus often called the anomalous attenuation. In this study, a linear integro-differential equation wave model was developed for the anomalous attenuation by using the space-fractional Laplacian operation, and the strategy is then extended to the nonlinear Burgers equation. A new definition of the fractional Laplacian is also introduced which naturally includes the boundary conditions and has inherent regularization to ease the hypersingularity in the conventional fractional Laplacian. Under the Szabo's smallness approximation, where attenuation is assumed to be much smaller than the wave number, the linear model is found consistent with arbitrary frequency power-law dependency.

  6. Can a Time Fractional-Derivative Model Capture Scale-Dependent Dispersion in Saturated Soils?

    PubMed

    Garrard, Rhiannon M; Zhang, Yong; Wei, Song; Sun, HongGuang; Qian, Jiazhong

    2017-07-10

    Time nonlocal transport models such as the time fractional advection-dispersion equation (t-fADE) were proposed to capture well-documented non-Fickian dynamics for conservative solutes transport in heterogeneous media, with the underlying assumption that the time nonlocality (which means that the current concentration change is affected by previous concentration load) embedded in the physical models can release the effective dispersion coefficient from scale dependency. This assumption, however, has never been systematically examined using real data. This study fills this historical knowledge gap by capturing non-Fickian transport (likely due to solute retention) documented in the literature (Huang et al. 1995) and observed in our laboratory from small to intermediate spatial scale using the promising, tempered t-fADE model. Fitting exercises show that the effective dispersion coefficient in the t-fADE, although differing subtly from the dispersion coefficient in the standard advection-dispersion equation, increases nonlinearly with the travel distance (varying from 0.5 to 12 m) for both heterogeneous and macroscopically homogeneous sand columns. Further analysis reveals that, while solute retention in relatively immobile zones can be efficiently captured by the time nonlocal parameters in the t-fADE, the motion-independent solute movement in the mobile zone is affected by the spatial evolution of local velocities in the host medium, resulting in a scale-dependent dispersion coefficient. The same result may be found for the other standard time nonlocal transport models that separate solute retention and jumps (i.e., displacement). Therefore, the t-fADE with a constant dispersion coefficient cannot capture scale-dependent dispersion in saturated porous media, challenging the application for stochastic hydrogeology methods in quantifying real-world, preasymptotic transport. Hence improvements on time nonlocal models using, for example, the novel subordination

  7. Variations in the magnitude of non mass dependent sulfur fractionation in the Archean atmosphere

    NASA Astrophysics Data System (ADS)

    Claire, M.; Kasting, J. F.

    2010-12-01

    Recent experimental data have enabled quantitatively meaningful computations of the non-mass dependent fractionation of sulfur’s isotopes (Δ33S) that exemplify the Archean rock record. The Δ33S signal originates as a result of fine structure in the absorption cross-section of SO2 isotopologues [1], which only undergo significant photolysis in reducing atmospheres [2]. The Δ33S signal produced by SO2 photolysis varies significantly between 190 and 220 nm, and thus is strongly dependent on any other atmospheric gases which absorb photons in this range [3], as well as the height at which photolysis occurs. A model that is capable of resolving the altitude-dependent radiative transfer through a realistic self-consistent reducing atmosphere is therefore essential when making direct comparisons between atmospheric Δ33S production and the rock record. In this work, we investigate how the magnitude of Δ33S might vary as function of atmospheric composition, which in turn allows the rock record to constrain the Archean atmosphere. Other recent work on this topic using simplied atmospheric models has implicated large concentrations of SO2 [5], OCS [3], and CO2 [6] as being responsible for the variations in Archean Δ33S. We present results from an altitude-dependent photochemical model of Archean photochemistry [4] of necessary complexity to resolve the complicated redox structure of the Archean atmosphere. We show that while increased concentrations of these gases all affect Δ33S in an unconstrained model, the atmospheric conditions required for OCS or SO2 shielding are unlikely to occur in an Archean atmosphere constrained by reasonable expectations of volcanic and biogenic fluxes. Within the context of plausible Archean atmospheres, we investigate how shielding due to changing amounts of CO2, biogenic sulfur gases, and fractal organic haze [7] affect the magnitude of Δ33S produced by the Archean atmosphere, and show why simplified atmospheric modeling may lead to

  8. An update on the Thermal Gradient Induced Non -Mass-Dependent Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Sun, T.; Niles, P. B.; Bao, H.; Socki, R. A.

    2012-12-01

    Mass flow and compositional gradient (elemental and isotope separation) occur when fluid(s) or gas(es) in an enclosure is subjected to a thermal gradient, and the phenomenon is named thermal diffusion. Gas phase thermal diffusion has been experimentally and theoretically investigated for more than a century, although there has not been a satisfactory theory to date. Nevertheless, theories predict that when dealing with a multi-isotope system, such as O16-O17-O18, S32-S33-S34-S36, or Ne20-Ne21-Ne22, the mass difference is the only term in the thermal diffusion separation factors that distinguish one isotope pair from another. Thus a mass dependent relationship is expected. For O-bearing molecules the α17O/ α 18O is expected to be at 0.5 to 0.515, and for S-bearing molecules the α33S/ α 34S at 0.5 to 0.508, where α is isotope fractionation factor between cold and warm reservoirs. We recently reported that thermal diffusion generates non-mass dependent (NMD) isotope fractionation for low-pressure O2 and SF6 gases. The observed NMD phenomenon in the simple thermal-diffusion experiments demands quantitative validation and theoretical explanation. It was suggested that additional (not mass related) terms need to be theoretically considered in the order to account for the observations. In addition to the pressure and temperature dependency illustrated in our earlier report, the role of turbulence, batch gas effects, and whether it is only a transient, non-equilibrium effect have been examined in this study. We report here new results on low-pressure O2 gas thermal diffusion. (1) In a purely diffusive vertical two-bulb setting with colder reservoir at lower position, time course experiments showed that the NMD effect persists after the system reaches isotopic steady state between warmer and colder compartments, suggesting that the effect is not a transient one. (2) When the average temperature approaching condensation point for O2, the 17O switches to migrating

  9. Non-monotonic dependence of Pickering emulsion gel rheology on particle volume fraction.

    PubMed

    Kaganyuk, M; Mohraz, A

    2017-03-29

    The microstructure of Pickering emulsion gels features a tenuous network of faceted droplets, bridged together by shared monolayers of particles. In this investigation, we use standard oscillatory rheometry in conjunction with confocal microscopy to gain a more comprehensive understanding of the role particle bridged interfaces have on the rheology of Pickering emulsion gels. The zero-shear elastic modulus of Pickering emulsion gels shows a non-monotonic dependence on particle loading, with three separate regimes of power-law and linear gel strengthening, and subsequent gel weakening. The transition from power-law to linear scaling is found to coincide with a peak in the volume fraction of particles that participate in bridging, which we indirectly calculate using measureable quantities, and the transition to gel weakening is shown to result from a loss in network connectivity at high particle loadings. These observations are explained via a simple representation of how Pickering emulsion gels arise from an initial population of partially-covered droplets. Based on these considerations, we propose a combined variable related to the initial droplet coverage, to be used in reporting and rationalizing the rheology of Pickering emulsion gels. We demonstrate the applicability of this variable with Pickering emulsions prepared at variable fluid ratios and with different-sized colloidal particles. The results of our investigation have important implications for many technological applications that utilize solid stabilized multi-phase emulsions and require a priori knowledge or engineering of their flow characteristics.

  10. Time-dependence of sea-ice concentration and multiyear ice fraction in the Arctic Basin

    USGS Publications Warehouse

    Gloersen, P.; Zwally, H.J.; Chang, A.T.C.; Hall, D.K.; Campbell, W.J.; Ramseier, R.O.

    1978-01-01

    The time variation of the sea-ice concentration and multiyear ice fraction within the pack ice in the Arctic Basin is examined, using microwave images of sea ice recently acquired by the Nimbus-5 spacecraft and the NASA CV-990 airborne laboratory. The images used for these studies were constructed from data acquired from the Electrically Scanned Microwave Radiometer (ESMR) which records radiation from earth and its atmosphere at a wavelength of 1.55 cm. Data are analyzed for four seasons during 1973-1975 to illustrate some basic differences in the properties of the sea ice during those times. Spacecraft data are compared with corresponding NASA CV-990 airborne laboratory data obtained over wide areas in the Arctic Basin during the Main Arctic Ice Dynamics Joint Experiment (1975) to illustrate the applicability of passive-microwave remote sensing for monitoring the time dependence of sea-ice concentration (divergence). These observations indicate significant variations in the sea-ice concentration in the spring, late fall and early winter. In addition, deep in the interior of the Arctic polar sea-ice pack, heretofore unobserved large areas, several hundred kilometers in extent, of sea-ice concentrations as low as 50% are indicated. ?? 1978 D. Reidel Publishing Company.

  11. Integration by parts and Pohozaev identities for space-dependent fractional-order operators

    NASA Astrophysics Data System (ADS)

    Grubb, Gerd

    2016-08-01

    Consider a classical elliptic pseudodifferential operator P on Rn of order 2a (0 < a < 1) with even symbol. For example, P = A(x , D)a where A (x , D) is a second-order strongly elliptic differential operator; the fractional Laplacian (- Δ)a is a particular case. For solutions u of the Dirichlet problem on a bounded smooth subset Ω ⊂Rn, we show an integration-by-parts formula with a boundary integral involving (d-a u)|∂Ω, where d (x) = dist (x , ∂ Ω). This extends recent results of Ros-Oton, Serra and Valdinoci, to operators that are x-dependent, nonsymmetric, and have lower-order parts. We also generalize their formula of Pohozaev-type, that can be used to prove unique continuation properties, and nonexistence of nontrivial solutions of semilinear problems. An illustration is given with P =(- Δ +m2)a. The basic step in our analysis is a factorization of P, P ∼P-P+, where we set up a calculus for the generalized pseudodifferential operators P± that come out of the construction.

  12. Novel PEFC Application for Deuterium Isotope Separation.

    PubMed

    Matsushima, Hisayoshi; Ogawa, Ryota; Shibuya, Shota; Ueda, Mikito

    2017-03-16

    The use of a polymer electrolyte fuel cell (PEFC) with a Nafion membrane for isotopic separation of deuterium (D) was investigated. Mass analysis at the cathode side indicated that D diffused through the membrane and participated in an isotope exchange reaction. The exchange of D with protium (H) in H₂O was facilitated by a Pt catalyst. The anodic data showed that the separation efficiency was dependent on the D concentration in the source gas, whereby the water produced during the operation of the PEFC was more enriched in D as the D concentration of the source gas was increased.

  13. Novel PEFC Application for Deuterium Isotope Separation

    PubMed Central

    Matsushima, Hisayoshi; Ogawa, Ryota; Shibuya, Shota; Ueda, Mikito

    2017-01-01

    The use of a polymer electrolyte fuel cell (PEFC) with a Nafion membrane for isotopic separation of deuterium (D) was investigated. Mass analysis at the cathode side indicated that D diffused through the membrane and participated in an isotope exchange reaction. The exchange of D with protium (H) in H2O was facilitated by a Pt catalyst. The anodic data showed that the separation efficiency was dependent on the D concentration in the source gas, whereby the water produced during the operation of the PEFC was more enriched in D as the D concentration of the source gas was increased. PMID:28772661

  14. Deuterium in North Atlantic storm tops

    NASA Technical Reports Server (NTRS)

    Smith, Ronald B.

    1992-01-01

    During the ERICA project in 1989, ice crystals were collected from the tops of two winter storms and one broad cirrus cloud. Deuterium concentration in the storm ice samples, together with a model of isotope fractionation, are used to determine the temperature where the ice was formed. Knowledge of the ice formation temperature allows us to determine whether the ice has fallen or been lofted to the altitude of collection. In both storms, the estimated fall distance decreases upward. In the 21 January storm, the fall distance decreases to zero at the cloud top. In the 23 January storm, the fall distance decreases to zero at a point 2 km below the cloud top and appears to become negative above, indicating lofted ice. Cloud particle data from the cloud tops show an ice-to-vapor ratio greater than one and indicate the presence of particles with small terminal velocities; both observations support the idea of ice lofting. The satellite-derived cloud tops lie well below the actual cloud top (e.g., 2.5 km below on 23 January), indicating that the lofted ice in winter storms may not be detectable from space using IR radiance techniques. A comparison of deuterium in cloud-top ice and clear-air vapor suggests that even in winter, when vertical air motions are relatively weak, lofted ice crystals are the dominant source of water vapor in the upper troposphere.

  15. Development of a time-dependent incompressible Navier-Stokes solver based on a fractional-step method

    NASA Technical Reports Server (NTRS)

    Rosenfeld, Moshe

    1990-01-01

    The development, validation and application of a fractional step solution method of the time-dependent incompressible Navier-Stokes equations in generalized coordinate systems are discussed. A solution method that combines a finite-volume discretization with a novel choice of the dependent variables and a fractional step splitting to obtain accurate solutions in arbitrary geometries was previously developed for fixed-grids. In the present research effort, this solution method is extended to include more general situations, including cases with moving grids. The numerical techniques are enhanced to gain efficiency and generality.

  16. Diffusion, trapping, and isotope exchange of plasma implanted deuterium in ion beam damaged tungsten

    NASA Astrophysics Data System (ADS)

    Barton, Joseph Lincoln

    Tritium accumulation in nuclear fusion reactor materials is a major concern for practical and safe fusion energy. This work examines hydrogen isotope exchange as a tritium removal technique, analyzes the effects of neutron damage using high energy copper ion beams, and introduces a diffusion coefficient that is a function of the concentration of trapped atoms. Tungsten samples were irradiated with high energy (0.5 - 5 MeV) copper ions for controlled levels of damage - 10-3 to 10-1 displacements per atom (dpa) - at room temperature. Samples were then exposed to deuterium plasma at constant temperature (˜ 380 K) to a high fluence of 1024 ions/m2, where retention is at is maximized (i.e. saturated). By then subsequently exposing these samples to fractions of this fluence with hydrogen plasma, isotope exchange rates were observed. The resulting deuterium still trapped in the tungsten is then measured post mortem. Nuclear reaction analysis (NRA) gives the depth resolved deuterium retention profile with the 3He(D,p) 4He reaction, and thermal desorption spectroscopy (TDS) gives the total amount of deuterium trapped in the tungsten by heating a sample in vacuum up to 1200 K and measuring the evaporated gas molecules with a residual gas analyzer. Isotope exchange data show that hydrogen atoms can displace trapped deuterium atoms efficiently only up to the first few microns, but does not affect the atoms trapped at greater depths. In ion damaged tungsten, measurements showed a significant increase in retention in the damage region proportional to dpa 0.66, which results in a significant spike in total retention, and isotope exchange in damaged samples is still ineffective at depths greater than a few microns. Thus, isotope exchange is not an affective tritium removal technique; however, these experiments have shown that trapping in material defects greatly affects diffusion. These experiments lead to a simplified diffusion model with defect densities as the only free

  17. Deuterium enrichment of the interstellar grain mantle

    NASA Astrophysics Data System (ADS)

    Das, Ankan; Sahu, Dipen; Majumdar, Liton; Chakrabarti, Sandip K.

    2016-01-01

    We carry out Monte Carlo simulation to study deuterium enrichments of interstellar grain mantles under various physical conditions. Based on the physical properties, various types of clouds are considered. We find that in diffuse cloud regions, very strong radiation fields persists and hardly a few layers of surface species are formed. In translucent cloud regions with a moderate radiation field, significant number of layers would be produced and surface coverage is mainly dominated by photo-dissociation products such as, C, CH3, CH2D, OH and OD. In the intermediate dense cloud regions (having number density of total hydrogen nuclei in all forms ˜2 × 104 cm-3), water and methanol along with their deuterated derivatives are efficiently formed. For much higher density regions (˜106 cm-3), water and methanol productions are suppressed but surface coverages of CO, CO2, O2 and O3 are dramatically increased. We find a very high degree of fractionation of water and methanol. Observational results support a high fractionation of methanol but surprisingly water fractionation is found to be low. This is in contradiction with our model results indicating alternative routes for de-fractionation of water. Effects of various types of energy barriers are also studied. Moreover, we allow grain mantles to interact with various charged particles (such as H+, Fe+, S+ and C+) to study the stopping power and projected range of these charged particles on various target ices.

  18. Human Milk MicroRNA and Total RNA Differ Depending on Milk Fractionation.

    PubMed

    Alsaweed, Mohammed; Hepworth, Anna R; Lefèvre, Christophe; Hartmann, Peter E; Geddes, Donna T; Hassiotou, Foteini

    2015-10-01

    MicroRNA have been recently discovered in human milk signifying potentially important functions for both the lactating breast and the infant. Whilst human milk microRNA have started to be explored, little data exist on the evaluation of sample processing, and analysis to ensure that a full spectrum of microRNA can be obtained. Human milk comprises three main fractions: cells, skim milk, and lipids. Typically, the skim milk fraction has been measured in isolation despite evidence that the lipid fraction may contain more microRNA. This study aimed to standardize isolation of microRNA and total RNA from all three fractions of human milk to determine the most appropriate sampling and analysis procedure for future studies. Three different methods from eight commercially available kits were tested for their efficacy in extracting total RNA and microRNA from the lipid, skim, and cell fractions of human milk. Each fraction yielded different concentrations of RNA and microRNA, with the highest quantities found in the cell and lipid fractions, and the lowest in skim milk. The column-based phenol-free method was the most efficient extraction method for all three milk fractions. Two microRNAs were expressed and validated in the three milk fractions by qPCR using the three recommended extraction kits for each fraction. High expression levels were identified in the skim and lipid milk factions for these microRNAs. These results suggest that careful consideration of both the human milk sample preparation and extraction protocols should be made prior to embarking upon research in this area.

  19. Human Milk MicroRNA and Total RNA Differ Depending on Milk Fractionation

    PubMed Central

    Alsaweed, Mohammed; Hepworth, Anna R.; Lefèvre, Christophe; Hartmann, Peter E.; Geddes, Donna T.

    2015-01-01

    ABSTRACT MicroRNA have been recently discovered in human milk signifying potentially important functions for both the lactating breast and the infant. Whilst human milk microRNA have started to be explored, little data exist on the evaluation of sample processing, and analysis to ensure that a full spectrum of microRNA can be obtained. Human milk comprises three main fractions: cells, skim milk, and lipids. Typically, the skim milk fraction has been measured in isolation despite evidence that the lipid fraction may contain more microRNA. This study aimed to standardize isolation of microRNA and total RNA from all three fractions of human milk to determine the most appropriate sampling and analysis procedure for future studies. Three different methods from eight commercially available kits were tested for their efficacy in extracting total RNA and microRNA from the lipid, skim, and cell fractions of human milk. Each fraction yielded different concentrations of RNA and microRNA, with the highest quantities found in the cell and lipid fractions, and the lowest in skim milk. The column‐based phenol‐free method was the most efficient extraction method for all three milk fractions. Two microRNAs were expressed and validated in the three milk fractions by qPCR using the three recommended extraction kits for each fraction. High expression levels were identified in the skim and lipid milk factions for these microRNAs. These results suggest that careful consideration of both the human milk sample preparation and extraction protocols should be made prior to embarking upon research in this area. J. Cell. Biochem. 116: 2397–2407, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. PMID:25925799

  20. [Consideration of the deuterium-free water supply to an expedition to Mars].

    PubMed

    Siniak, Iu E; Turusov, V S; Grigor'ev, A I; Zaridze, D G; Gaĭdadymov, V B; Gus'kova, E I; Antoshina, E E; Gor'kova, T G; Trukhanova, L S

    2003-01-01

    Interplanetary missions, including to Mars, will put crews into severe radiation conditions. Search for methods of reducing the risk of radiation-induced cancer is of the top priority in preparation for the mission to Mars. One of the options is designing life support systems that will generate water with low content of the stable hydrogen isotope (deuterium) to be consumed by crewmembers. Preliminary investigations have shown that a decrease of the deuterium fraction by 65% does impart to water certain anti-cancer properties. Therefore, drinking deuterium-free water has the potential to reduce the risk of cancer consequent to the extreme radiation exposure of the Martian crew.

  1. Detection of atomic deuterium in the upper atmosphere of Mars.

    PubMed

    Krasnopolsky, V A; Mumma, M J; Gladstone, G R

    1998-06-05

    High-resolution spectroscopy of Mars' atmosphere with the Hubble Space Telescope revealed the deuterium Lyman alpha line at an intensity of 23 +/- 6 rayleighs. This measured intensity corresponds to HD/H2 = 1.5 +/- 0.6 x 10(-4), which is smaller by a factor of 11 than HDO/H2O. This indicates that fractionation of HD/H2 relative to that of HDO/H2O is not kinetically controlled by the rates of formation and destruction of H2 and HD but is thermodynamically controlled by the isotope exchange HD + H2O left and right arrow HDO + H2. Molecular hydrogen is strongly depleted in deuterium relative to water on Mars because of the very long lifetime of H2 (1200 years). The derived isotope fractionation corresponds to an estimate of a planetwide reservoir of water ice about 5 meters thick that is exchangeable with the atmosphere.

  2. Detection of atomic deuterium in the upper atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, V. A.; Mumma, M. J.; Gladstone, G. R.

    1998-01-01

    High-resolution spectroscopy of Mars' atmosphere with the Hubble Space Telescope revealed the deuterium Lyman alpha line at an intensity of 23 +/- 6 rayleighs. This measured intensity corresponds to HD/H2 = 1.5 +/- 0.6 x 10(-4), which is smaller by a factor of 11 than HDO/H2O. This indicates that fractionation of HD/H2 relative to that of HDO/H2O is not kinetically controlled by the rates of formation and destruction of H2 and HD but is thermodynamically controlled by the isotope exchange HD + H2O left and right arrow HDO + H2. Molecular hydrogen is strongly depleted in deuterium relative to water on Mars because of the very long lifetime of H2 (1200 years). The derived isotope fractionation corresponds to an estimate of a planetwide reservoir of water ice about 5 meters thick that is exchangeable with the atmosphere.

  3. Detection of atomic deuterium in the upper atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, V. A.; Mumma, M. J.; Gladstone, G. R.

    1998-01-01

    High-resolution spectroscopy of Mars' atmosphere with the Hubble Space Telescope revealed the deuterium Lyman alpha line at an intensity of 23 +/- 6 rayleighs. This measured intensity corresponds to HD/H2 = 1.5 +/- 0.6 x 10(-4), which is smaller by a factor of 11 than HDO/H2O. This indicates that fractionation of HD/H2 relative to that of HDO/H2O is not kinetically controlled by the rates of formation and destruction of H2 and HD but is thermodynamically controlled by the isotope exchange HD + H2O left and right arrow HDO + H2. Molecular hydrogen is strongly depleted in deuterium relative to water on Mars because of the very long lifetime of H2 (1200 years). The derived isotope fractionation corresponds to an estimate of a planetwide reservoir of water ice about 5 meters thick that is exchangeable with the atmosphere.

  4. Local control dependence on consecutive vs. nonconsecutive fractionation in lung stereotactic body radiation therapy.

    PubMed

    Alite, Fiori; Stang, Kyle; Balasubramanian, Neelam; Adams, William; Shaikh, Mohammad Parvez; Small, Christina; Sethi, Anil; Nagda, Suneel; Emami, Bahman; Harkenrider, Matthew M

    2016-10-01

    Recent reports demonstrate impaired tumor re-oxygenation 24-48h after stereotactic body radiation therapy (SBRT), suggesting that non-consecutive treatment delivery may be advantageous. To test this hypothesis clinically, we compared local control in patients treated in consecutive daily fractions vs. nonconsecutive fractions. We retrospectively reviewed 107 lung SBRT patients (117 tumors) treated for T1-T2N0 NSCLC with LINAC based SBRT (50 or 60Gy/5fractions). Patients were characterized as having been treated in consecutive daily fractions vs. in non-consecutive fractions. Local control, survival and toxicity end points (CTCAE V4.0) were compared. Propensity score matching and Cox regression analyses were performed in order to determine the effect of fractionation on local control. With a median follow up of 23.7months, 3-year local control was superior at 93.3% vs. 63.6% in the non-consecutive and consecutive group, respectively (p=0.001). Multivariate analysis and propensity score matching showed that consecutive fractionation was an independent predictor of local failure. Overall survival trended toward improvement in the non-consecutive group, but this was not statistically significant (p=0.188). Development of any grade 2 toxicity was not significantly different between the two groups (p=0.75). Five-fraction SBRT delivered over non-consecutive days imparts superior LC and similar toxicity compared to consecutive fractionation. These results should be validated in independent datasets and in a prospective fashion. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Spectral irradiance standard for the ultraviolet - The deuterium lamp

    NASA Technical Reports Server (NTRS)

    Saunders, R. D.; Ott, W. R.; Bridges, J. M.

    1978-01-01

    A set of deuterium lamps is calibrated as spectral irradiance standards in the 200-350-nm spectral region utilizing both a high accuracy tungsten spectral irradiance standard and a newly developed argon mini-arc spectral radiance standard. The method which enables a transfer from a spectral radiance to a spectral irradiance standard is described. The following characteristics of the deuterium lamp irradiance standard are determined: sensitivity to alignment; dependence on input power and solid angle; reproducibility; and stability. The absolute spectral radiance is also measured in the 167-330-nm region. Based upon these measurements, values of the spectral irradiance below 200 nm are obtained through extrapolation.

  6. Transport of Recycled Deuterium to the Plasma Core in TFTR

    SciTech Connect

    Bell, M.G.; Budny, R.V.; Jassby, D.L.; Park, H.; Skinner, C.H.; et al

    1997-10-01

    We report a study of the fueling of the plasma core by recycling in the Tokamak Fusion Test Reactor (TFTR) [Phys. Plasmas 2, 2176 (1995)]. We have analyzed discharges fueled by deuterium recycled from the limiter and tritium-only neutral beam injection. In these plasmas, the DT neutron rate provides a measure of the deuterium influx into the core plasma. We find a reduced influx with plasmas using lithium pellet conditioning and with plasmas of reduced major (and minor) radius. Modeling with the DEGAS neutrals code shows that the dependence on radius can be related to the penetration of neutrals through the scrape-off layer.

  7. Transport of recycled deuterium to the plasma core in TFTR

    SciTech Connect

    Skinner, C.H.; Bell, M.G.; Budny, R.V.; Jassby, D.L.; Park, H.; Ramsey, A.T.; Stotler, D.P.; Strachan, J.D.

    1997-10-01

    The authors report a study of the fueling of the plasma core by recycling in the Tokamak Fusion Test Reactor (TFTR). They have analyzed discharges fueled by deuterium recycled from the limiter and tritium-only neutral beam injection. In these plasmas, the DT neutron rate provides a measure of the deuterium influx into the core plasma. They find a reduced influx with plasmas using lithium pellet conditioning and with plasmas of reduced major (and minor) radius. Modeling with the DEGAS neutrals code shows that the dependence on radius can be related to the penetration of neutrals through the scrape-off layer.

  8. NOTE: On the Deuterium Abundance on Mars and Some Related Problems

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, Vladimir

    2000-12-01

    Strong fractionation of deuterium in photolysis of H 2O and above the hygropause reduces the production of HD relative to H 2 on Mars by a factor of 3.7 total. The model by Y. L. Yung et al. (1988, Icarus76, 146-159) for deuterium fractionation in chemical reactions on Mars corrected for this factor results in (HD/H 2)/(HDO/H 2O)=0.43. This value may fit the deuterium abundance observed by V. A. Krasnopolsky et al. (1998, Science 280, 1576-1580) if the eddy diffusion coefficient does not depend on solar activity: K=1.4×10 13n-1/2 cm 2 s -1 (model 2). The Mariner 9 observations show very low variability of atomic oxygen at the 1.2 n bar pressure level (h˜125 km) with solar activity. This requires eddy diffusion to be proportional to the solar activity index F10.7: K=( F10.7 cm/30)×10 13n-1/2 cm 2 s -1 (model 1). The fractionation factor for escape of hydrogen isotopes is equal to 0.016 and 0.135 for models 1 and 2. These values have been averaged over the solar cycle. The three-reservoir model for hydrogen isotope fractionation suggested by Krasnopolsky et al. (1998) involves a reservoir composed primarily of water ice in the polar caps that isotopically interacts with the atmosphere. Assuming that water ice is half of the total volume of the polar caps and the polar-layered deposits, the total loss of water from Mars is equal to 65 and 120 m for models 1 and 2, respectively. Along with thermal and nonthermal escape, these values may include the loss of water by oxidation of regolith, if the released hydrogen escaped with isotopic fractionation. Although the solar-wind α particles are the main source of He on Mars, capture of the solar-wind H + and D + ions by Mars has a negligible effect on the thermospheric abundances of H and D. Improved observations of minor components in Mars' thermosphere may resolve the problem of eddy diffusion at various solar activity and choosing between the models.

  9. Study of ion-irradiated tungsten in deuterium plasma

    NASA Astrophysics Data System (ADS)

    Khripunov, B. I.; Gureev, V. M.; Koidan, V. S.; Kornienko, S. N.; Latushkin, S. T.; Petrov, V. B.; Ryazanov, A. I.; Semenov, E. V.; Stolyarova, V. G.; Danelyan, L. S.; Kulikauskas, V. S.; Zatekin, V. V.; Unezhev, V. N.

    2013-07-01

    Experimental study aimed at investigation of neutron induced damage influence on fusion reactor plasma facing materials is reported. Displacement damage was produced in tungsten by high-energy helium and carbon ions at 3-10 MeV. The reached level of displacement damage ranged from several dpa to 600 dpa. The properties of the irradiated tungsten were studied in steady-state deuterium plasma on the LENTA linear divertor simulator. Plasma exposures were made at 250 eV of ion energy to fluence 1021-1022 ion/сm2. Erosion dynamics of the damaged layer and deuterium retention were observed. Surface microstructure modifications and important damage of the 5 μm layer shown. Deuterium retention in helium-damaged tungsten (ERD) showed its complex behavior (increase or decrease) depending on implanted helium quantity and the structure of the surface layer.

  10. Nucleon structure at large x: nuclear effects in deuterium

    SciTech Connect

    Wally Melnitchouk

    2010-07-01

    I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x -> 1. A new global study of parton distributions, using less restrictive kinematic cuts in Q^2 and W^2, finds strong suppression of the d quark distribution once nuclear corrections are accounted for.

  11. Solid deuterium centrifuge pellet injector

    SciTech Connect

    Foster, C.A.

    1982-01-01

    Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150/sup 0/ of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s.

  12. Deuterium pellet injector gun design

    SciTech Connect

    Lunsford, R.V.; Wysor, R.B.; Bryan, W.E.; Shipley, W.D.; Combs, S.K.; Foust, C.R.; Milora, S.L.; Fisher, P.W.

    1985-01-01

    The Deuterium Pellet Injector (DPI), an eight-pellet pneumatic injector, is being designed and fabricated for the Tokamak Fusion Test Reactor (TFTR). It will accelerate eight pellets, 4 by 4 mm maximum, to greater than 1500 m/s. It utilizes a unique pellet-forming mechanism, a cooled pellet storage wheel, and improved propellant gas scavenging.

  13. Regio-Selective Intramolecular Hydrogen/Deuterium Exchange in Gas-Phase Electron Transfer Dissociation.

    PubMed

    Hamuro, Yoshitomo

    2017-05-01

    Protein backbone amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) typically utilizes enzymatic digestion after the exchange reaction and before MS analysis to improve data resolution. Gas-phase fragmentation of a peptic fragment prior to MS analysis is a promising technique to further increase the resolution. The biggest technical challenge for this method is elimination of intramolecular hydrogen/deuterium exchange (scrambling) in the gas phase. The scrambling obscures the location of deuterium. Jørgensen's group pioneered a method to minimize the scrambling in gas-phase electron capture/transfer dissociation. Despite active investigation, the mechanism of hydrogen scrambling is not well-understood. The difficulty stems from the fact that the degree of hydrogen scrambling depends on instruments, various parameters of mass analysis, and peptide analyzed. In most hydrogen scrambling investigations, the hydrogen scrambling is measured by the percentage of scrambling in a whole molecule. This paper demonstrates that the degree of intramolecular hydrogen/deuterium exchange depends on the nature of exchangeable hydrogen sites. The deuterium on Tyr amide of neurotensin (9-13), Arg-Pro-Tyr-Ile-Leu, migrated significantly faster than that on Ile or Leu amides, indicating the loss of deuterium from the original sites is not mere randomization of hydrogen and deuterium but more site-specific phenomena. This more precise approach may help understand the mechanism of intramolecular hydrogen exchange and provide higher confidence for the parameter optimization to eliminate intramolecular hydrogen/deuterium exchange during gas-phase fragmentation. Graphical Abstract ᅟ.

  14. Regio-Selective Intramolecular Hydrogen/Deuterium Exchange in Gas-Phase Electron Transfer Dissociation

    NASA Astrophysics Data System (ADS)

    Hamuro, Yoshitomo

    2017-05-01

    Protein backbone amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) typically utilizes enzymatic digestion after the exchange reaction and before MS analysis to improve data resolution. Gas-phase fragmentation of a peptic fragment prior to MS analysis is a promising technique to further increase the resolution. The biggest technical challenge for this method is elimination of intramolecular hydrogen/deuterium exchange (scrambling) in the gas phase. The scrambling obscures the location of deuterium. Jørgensen's group pioneered a method to minimize the scrambling in gas-phase electron capture/transfer dissociation. Despite active investigation, the mechanism of hydrogen scrambling is not well-understood. The difficulty stems from the fact that the degree of hydrogen scrambling depends on instruments, various parameters of mass analysis, and peptide analyzed. In most hydrogen scrambling investigations, the hydrogen scrambling is measured by the percentage of scrambling in a whole molecule. This paper demonstrates that the degree of intramolecular hydrogen/deuterium exchange depends on the nature of exchangeable hydrogen sites. The deuterium on Tyr amide of neurotensin (9-13), Arg-Pro-Tyr-Ile-Leu, migrated significantly faster than that on Ile or Leu amides, indicating the loss of deuterium from the original sites is not mere randomization of hydrogen and deuterium but more site-specific phenomena. This more precise approach may help understand the mechanism of intramolecular hydrogen exchange and provide higher confidence for the parameter optimization to eliminate intramolecular hydrogen/deuterium exchange during gas-phase fragmentation.

  15. Regio-Selective Intramolecular Hydrogen/Deuterium Exchange in Gas-Phase Electron Transfer Dissociation

    NASA Astrophysics Data System (ADS)

    Hamuro, Yoshitomo

    2017-02-01

    Protein backbone amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) typically utilizes enzymatic digestion after the exchange reaction and before MS analysis to improve data resolution. Gas-phase fragmentation of a peptic fragment prior to MS analysis is a promising technique to further increase the resolution. The biggest technical challenge for this method is elimination of intramolecular hydrogen/deuterium exchange (scrambling) in the gas phase. The scrambling obscures the location of deuterium. Jørgensen's group pioneered a method to minimize the scrambling in gas-phase electron capture/transfer dissociation. Despite active investigation, the mechanism of hydrogen scrambling is not well-understood. The difficulty stems from the fact that the degree of hydrogen scrambling depends on instruments, various parameters of mass analysis, and peptide analyzed. In most hydrogen scrambling investigations, the hydrogen scrambling is measured by the percentage of scrambling in a whole molecule. This paper demonstrates that the degree of intramolecular hydrogen/deuterium exchange depends on the nature of exchangeable hydrogen sites. The deuterium on Tyr amide of neurotensin (9-13), Arg-Pro-Tyr-Ile-Leu, migrated significantly faster than that on Ile or Leu amides, indicating the loss of deuterium from the original sites is not mere randomization of hydrogen and deuterium but more site-specific phenomena. This more precise approach may help understand the mechanism of intramolecular hydrogen exchange and provide higher confidence for the parameter optimization to eliminate intramolecular hydrogen/deuterium exchange during gas-phase fragmentation.

  16. Coil fraction-dependent phase behaviour of a model globular protein–polymer diblock copolymer

    SciTech Connect

    Thomas, Carla S.; Olsen, Bradley D.

    2014-01-01

    The self-assembly of the model globular protein–polymer block copolymer mCherry-b-poly(N-isopropyl acrylamide) is explored across a range of polymer coil fractions from 0.21 to 0.82 to produce a phase diagram for these materials as a function of molecular composition. Overall, four types of morphologies were observed: hexagonally packed cylinders, perforated lamellae, lamellae, and disordered nanostructures. Across all coil fractions and morphologies, a lyotropic re-entrant order–disorder transition in water was observed, with disordered structures below 30 wt% and above 70 wt% and well-ordered morphologies at intermediate concentrations. Solid state samples prepared by solvent evaporation show moderately ordered structures similar to those observed in 60 wt% solutions, suggesting that bulk structures result from kinetic trapping of morphologies which appear at lower concentrations. While highly ordered cylindrical nanostructures are observed around a bioconjugate polymer volume fraction of 0.3 and well-ordered lamellae are seen near a volume fraction of 0.6, materials at lower or higher coil fractions become increasingly disordered. Notable differences between the phase behaviour of globular protein–polymer block copolymers and coil–coil diblock copolymers include the lack of spherical nanostructures at either high or low polymer coil fractions as well as shifted phase boundaries between morphologies which result in an asymmetric phase diagram.

  17. A molecular dynamic model for analyzing concentrations of electrolytes: Fractional molar dependences of microstructure properties

    NASA Astrophysics Data System (ADS)

    Khalansky, D.; Popova, E.; Gladyshev, P.; Dushanov, E.; Kholmurodov, Kh.

    2014-12-01

    Aqueous electrolyte solutions play an important role in many electrophysical and chemical processes in aerospace technology and industrial applications. As noncovalent interactions, the interactions between ions are crucially important for biomolecular structures as well (protein structure folding, molecular level processes followed by ionic pair correlations, the formation of flexible hydrate shells, and so on). Specifically, ions (cations and anions with the same valence charges) can form stable pairs if their sizes match. The formation of ionic pairs can substantially affect the thermodynamic stabilities of proteins in the alkali salts physiologically present in the human body. Research aims and problems impose severe demands on readjustments of the ionic force fields and potential parameters developed to describe aqueous solutions and electrolytic systems. Ionic solutions and their interaction with biomolecules have been observed for over 100 years [1], but the behavior of such solutions remains poorly studied today. New data obtained in this work deals with parameterization strategies and adjustments for the ionic force fields of the alkali cations and halide anions that should be helpful in biomolecular research. Using molecular dynamics (MD) models, four electrolytic systems (HCl-H2O, LiCl-H2O, NaCl-H2O, and KCl-H2O) are investigated as binary mixtures of water and cations and anions, respectively. The intermolecular interaction parameters are varied for two of the four model electrolytes (HCl-H2O and NaCl-H2O) to simulate the possibility of different ionic shells forming during interaction with water. It is found that varying the potential parameters strongly affects the dynamic and structural characteristics of electrolyte systems. MD simulations are performed in the temperature range of 300 to 600 K with a step of 50 K. MD simulations for all electrolyte models (HCl-H2O, LiCl-H2O, NaCl-H2O, KCl-H2O) are also conducted for different molar fractions of

  18. Palm oil tocotrienol fractions restore endothelium dependent relaxation in aortic rings of streptozotocin-induced diabetic and spontaneously hypertensive rats.

    PubMed

    Muharis, Syed Putra; Top, Abdul Gapor Md; Murugan, Dharmani; Mustafa, Mohd Rais

    2010-03-01

    Diabetes and hypertension are closely associated with impaired endothelial function. Studies have demonstrated that regular consumption of edible palm oil may reverse endothelial dysfunction. The present study investigates the effect of palm oil fractions: tocotrienol rich fraction (TRF), alpha-tocopherol and refined palm olein (vitamin E-free fraction) on the vascular relaxation responses in the aortic rings of streptozotocin-induced diabetic and spontaneously hypertensive rats (SHR). We hypothesize that the TRF and alpha-tocopherol fractions are able to improve endothelial function in both diabetic and hypertensive rat aortic tissue. A 1,1-diphenyl picryl hydrazyl assay was performed on the various palm oil fractions to evaluate their antioxidant activities. Endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside) relaxations were examined on streptozotocin-induced diabetic and SHR rat aorta following preincubation with the different fractions. In 1-diphenyl picryl hydrazyl antioxidant assay, TRF and alpha-tocopherol fractions exhibited a similar degree of activity while palm olein exhibited poor activity. TRF and alpha-tocopherol significantly improved acetylcholine-induced relaxations in both diabetic (TRF, 88.5% +/- 4.5%; alpha-tocopherol, 87.4% +/- 3.4%; vehicle, 65.0 +/- 1.6%) and SHR aorta (TRF, 72.1% +/- 7.9%; alpha-tocopherol, 69.8% +/- 4.0%, vehicle, 51.1% +/- 4.7%), while palm olein exhibited no observable effect. These results suggest that TRF and alpha-tocopherol fractions possess potent antioxidant activities and provide further support to the cardiovascular protective effects of palm oil vitamin E. TRF and alpha-tocopherol may potentially improve vascular endothelial function in diabetes and hypertension by their sparing effect on endothelium derived nitric oxide bioavailability.

  19. Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K.

    PubMed

    Morozov, Oleksandr; Zhurba, Volodymyr; Neklyudov, Ivan; Mats, Oleksandr; Rud, Aleksandr; Chernyak, Nikolay; Progolaieva, Viktoria

    2015-01-01

    Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 10(15) to 5 × 10(18) D/cm(2). The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.

  20. Studies of quaternary saline lakes-I. Hydrogen isotope fractionation in saline minerals

    USGS Publications Warehouse

    Matsuo, S.; Friedman, I.; Smith, G.I.

    1972-01-01

    Borax, gaylussite, nahcolite and trona were synthesized in aqueous solution at temperatures ranging from 8?? to 35??C. Except for borax, deuterium was always depleted in these hydrated minerals relative to the solutions from which they were crystallized. In borax, no significant fractionation was found. The fractionation factor of D H for the trona-water system exhibited a marked temperature dependence. By combining the deuterium contents of trona and the solution from which trona was crystallized, the following thermometer scale was obtained: In ( D H) trona ( D H)water = 1.420 ?? 104 T2 + 23.56 T (1). An attempt to establish a geothermometer based on C13 C12 fractionation between carbonate minerals and carbonate ions in aqueous solution was not successful. ?? 1972.

  1. Species-dependent silicon isotope fractionation in unialgal cultures of marine diatoms

    NASA Astrophysics Data System (ADS)

    Sutton, J. N.; Varela, D. E.; Brzezinski, M. A.; Beucher, C.

    2011-12-01

    Variations in the natural abundance of stable isotopes of silicon (expressed as δ30Si in %) are a key tool for studying the marine silicon (Si) cycle in modern and ancient oceans. In particular, this tool can be used to track relative differences in silicic acid drawdown in surface waters by siliceous microplankton. Diatoms are siliceous phytoplankton that dominate the cycling of Si in the oceans. They represent a major source of primary production and are important in the transfer of Si, nitrogen, phosphorus, and atmospheric carbon to the deep sea. Previous investigations of Si isotope fractionation in diatom cultures have ruled out the influence of temperature (12-22°C) and shown that Si fractionation was invariant in different species of temperate diatoms (De La Rocha et al. 1997). However, the application of this proxy for marine paleo-silicon reconstructions has typically only been used in polar regions, such as the Southern Ocean, where high primary production rates give rise to diatom-rich sediments. Here, we present results on the fractionation of Si isotopes by four species of polar diatoms grown in semi-continuous cultures (Chaetoceros brevis, Fragilariopsis kerguelensis, Porosira glacialis, and Thalassiosira antarctica). To compare with previous studies (De La Rocha et al, 1997), we also tested Si isotope fractionation by two species of temperate diatoms (Thalassiosira pseudonana and Thalassiosira weissflogii). The temperate species yielded Si isotope fractionation (Δ30Si) values of -0.81 % (±0.12, SD, n=11) for T. pseudonana and -1.03% (±0.09, SD, n=3) for T. weissflogii, that are identical to the previously reported fractionation of -1.1 % (±0.4, SD, n=6) (De La Rocha et al. 1997). Similarly, our data for polar species F. kerguelensis, P. glacialis and T. antarctica suggest a fractionation of -0.7 to -1.1 %. Interestingly, our preliminary results from Chaetoceros brevis cultures show a Si isotope fractionation value of about -2.61 % (±0.05, SD

  2. Temperature dependence of oxygen isotope acid fractionation for modern and fossil tooth enamels.

    PubMed

    Passey, Benjamin H; Cerling, Thure E; Levin, Naomi E

    2007-01-01

    The oxygen isotope ratio of CO(2) liberated from structural carbonate in tooth enamel apatite was measured at phosphoric acid reaction temperatures of 25 degrees C, 60 degrees C and 90 degrees C, and it was found that apparent acid fractionation factors for pristine enamel, fossilized enamel, and calcite follow different temperature relationships. Using sealed vessel reactions normalized to alpha(25) = 1.01025 (the fractionation factor for calcite at 25 degrees C), the apparent fractionation factor at 90 degrees C (alpha*(90)) for pristine enamel ranged between 1.00771 and 1.00820, and between 1.00695 and 1.00772 for fossilized enamel. Apparent fractionation factors for common acid bath reactions are similar to those for sealed vessel reactions. A significant correlation exists between alpha*(90) and F(-) content, suggesting that change in the acid fractionation factor may be related to the replacement of OH(-) with F(-) during fossilization of bioapatite. These results have important implications for making accurate comparisons between modern and fossil tooth enamel delta(18)O values, and for the uniformity of isotope data produced in different laboratories using different acid reaction temperatures.

  3. Dependence of particle volume fraction on sound velocity and attenuation of EPDM composites.

    PubMed

    Kim, K S; Lee, K I; Kim, H Y; Yoon, S W; Hong, S H

    2007-05-01

    The sound velocity and the attenuation coefficient of EPDM (Ethylene-propylene Diene Monomer) composites incorporated with Silicon Carbide particles (SiCp's) of various volume fractions (0-40%) were experimentally and theoretically investigated. For the experiment a through-transmission technique was used. For the theoretical prediction, some mechanical property models such as Reuss model and Coherent Potential Approximation (CPA) model etc. were employed. The experimental results showed that the sound velocity decreased with the increase of the SiCp volume fraction up to 30% and then increased with the 40 vol% specimen. The attenuation coefficient was increased with the increasing SiCp volume fractions. The modified Reuss model with a longitudinal elastic modulus predicted most well the experimental sound velocity and elastic modulus results.

  4. Simulation of the modulation transfer function dependent on the partial Fourier fraction in dynamic contrast enhancement magnetic resonance imaging.

    PubMed

    Takatsu, Yasuo; Ueyama, Tsuyoshi; Miyati, Tosiaki; Yamamura, Kenichirou

    2016-12-01

    The image characteristics in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) depend on the partial Fourier fraction and contrast medium concentration. These characteristics were assessed and the modulation transfer function (MTF) was calculated by computer simulation. A digital phantom was created from signal intensity data acquired at different contrast medium concentrations on a breast model. The frequency images [created by fast Fourier transform (FFT)] were divided into 512 parts and rearranged to form a new image. The inverse FFT of this image yielded the MTF. From the reference data, three linear models (low, medium, and high) and three exponential models (slow, medium, and rapid) of the signal intensity were created. Smaller partial Fourier fractions, and higher gradients in the linear models, corresponded to faster MTF decline. The MTF more gradually decreased in the exponential models than in the linear models. The MTF, which reflects the image characteristics in DCE-MRI, was more degraded as the partial Fourier fraction decreased.

  5. Influence of traps on the deuterium behaviour in the low activation martensitic steels F82H and Batman

    NASA Astrophysics Data System (ADS)

    Serra, E.; Perujo, A.; Benamati, G.

    1997-06-01

    A time dependent permeation method is used to measure the permeability, diffusivity and solubility of deuterium in the low activation martensitic steels F82H and Batman. The measurements cover the temperature range from 373 to 743 K which includes the onset of deuterium trapping effects on diffusivity and solubility. The results are interpreted using a trapping model. The number of trap sites and their average energies for deuterium in F82H and Batman steels are determined.

  6. Electroproduction of kaons on hydrogen and deuterium

    NASA Astrophysics Data System (ADS)

    Koltenuk, Douglas Michael

    1999-10-01

    High-statistics data have been acquired for the reactions p(e,e'K+) and d(e,eK+) over a range of W from 1.70-1.95 GeV. Coincidence measurements at Q 2 = 0.38, 0.50, and 0.52 GeV2 cover a range of virtual photon-kaon angles for both liquid hydrogen and deuterium targets. Monte Carlo simulations have been matched to the data in order to extract cross sections. The W-dependence of the p(e,e'K+)Λ and p(e,e'K+)Σ0 cross sections deviates from a previous model fitted to photoproduction data. The difference in cross sections on hydrogen and on the proton in deuterium has been quantified for Λ production. The subtraction of the Λ and Σ 0 contribution from the proton in the deuteron allows the extraction of n(e,e'K+)Σ- cross sections. The wealth of new data on Λ, Σ0, and Σ - production will put tight constraints on existing models for kaon production and form factors.

  7. Thermal desorption of deuterium implanted into beryllium

    SciTech Connect

    Markin, A.V.; Chernikov, V.N.; Zakharov, A.P.

    1995-09-01

    By means of TDS measurements it is shown that the desorption of deuterium from Be implanted with 5 keV D ions to fluences, {Phi}, from 1x10{sup 20} D/m{sup 2} to 1x10{sup 21} D/m{sup 2} proceeds in one high temperature stage B, while at {Phi} {ge} 1.2x10{sup 21}D/m{sup 2} one more stage A is added. The desorption maximum A is narrow and consists of two peaks A{sub 1} and A{sub 2} at about 460 K and 490 K, respectively. Peak A{sub 1} is attributed to the desorption of deuterium from the walls of opened channels formed under D ion implantation. Peak {sub A}2 is a consequence of the opening of a part of closed bubbles/channels to the outer surface. The position of maximum B shifts noticeably and nonsteadily on the fluence in a range from 850 to 1050 K. The origin of this maximum is the liberation of D atoms bound at vacancy complexes discussed previously by Wampler. The dependence of Tm(B) on the fluence is governed by the interaction of freely migrating D atoms with partly opened or fully closed gas cavity arrangements which are created under temperature ramping, but differently in specimens implanted with D ions to different fluences.

  8. Palliative radiotherapy fractionation schedules prescribed are dependent on the distance a patient travels to receive treatment.

    PubMed

    Barnes, Mark; Tiwana, Manpreet S; Miller, Stacy; Kiraly, Andrew; Olivotto, Ivo A; Emmons, Scott; Olson, Robert A

    2015-11-01

    This study assessed the impact of the distance a patient travelled to the treatment centre on the use of single fraction RT for bone metastases. There was significant variability in the prescription of SFRT by distance at which the patient lives from a cancer centre (p<0.001).

  9. NOTE: Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images

    NASA Astrophysics Data System (ADS)

    Larsson, Anne; Johansson, Lennart

    2003-11-01

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  10. More than just halo mass: modelling how the red galaxy fraction depends on multiscale density in an HOD framework

    NASA Astrophysics Data System (ADS)

    Phleps, S.; Wilman, D. J.; Zibetti, S.; Budavári, T.

    2014-03-01

    The fraction of galaxies with red colours depends sensitively on environment, and on the way in which environment is measured. To distinguish competing theories for the quenching of star formation, a robust and complete description of environment is required, to be applied to a large sample of galaxies. The environment of galaxies can be described using the density field of neighbours on multiple scales - the multiscale density field. We are using the Millennium simulation and a simple halo occupation distribution (HOD) prescription which describes the multiscale density field of Sloan Digital Sky Survey DR7 galaxies to investigate the dependence of the fraction of red galaxies on the environment. Using a volume-limited sample, where we have sufficient galaxies in narrow density bins, we have more dynamic range in halo mass and density for satellite galaxies than for central galaxies. Therefore, we model the red fraction of central galaxies as a constant while we use a functional form to describe the red fraction of satellites as a function of halo mass which allows us to distinguish a sharp from a gradual transition. While it is clear that the data can only be explained by a gradual transition, an analysis of the multiscale density field on different scales suggests that colour segregation within the haloes is needed to explain the results. We also rule out a sharp transition for central galaxies, within the halo mass range sampled.

  11. Estimation of Nuclear Volume Dependent Fractionation of Mercury Isotopes Using Octanol- Water Partitioning of Inorganic Mercury

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Bergquist, B. A.; Schauble, E. A.; Blum, J. D.

    2009-05-01

    Mercury is a globally distributed pollutant; the toxicity and biomagnifications in aquatic food chains, even in remote areas, makes it a serious worldwide problem. Similar to other stable isotope systems, the isotopic composition of environmental Hg is potentially a new tool to better understand the biogeochemical cycling, fluxes and anthropogenic impacts of Hg. The promise of Hg isotopes is even more exciting with the recent discovery of large mass independent fractionation (MIF) displayed by the odd Hg isotopes (199Hg and 201Hg). Based on current theory MIF of Hg isotopes can arise either from the non-linear scaling of nuclear volume with mass for heavy isotopes (Nuclear Volume Effect, NVE) or from the magnetic isotope effect (MIE), which is due to the non-zero nuclear spin and nuclear magnetic moments of odd-mass isotopes. In order to interpret and use Hg MIF signatures in nature, both experimental and theoretical work is needed to better understand the controls and expression of MIF along with the underlying mechanisms of MIF. The goal of the current study was to design an experiment that would express the NVE in order to confirm theoretical predictions of the isotopic signature of the NVE for Hg. Unfortunately, both NVE and MIE predict MIF for only the odd isotopes. However since MIE is a kinetic phenomenon only, MIF observed in equilibrium reactions should be attributable to the NVE only. Thus it should be possible to isolate NVE driven MIF from MIE driven MIF. A laboratory experiment was designed on equilibrium octanol-water partitioning of different Hg chloride species. Octanol-water partitioning of Hg depends on the hydrophobicity of the Hg species, so non polar lipophilic species partition into the octanol phase while polar species remain in water phase. At 25 degree Celsius, a Cl- concentration of 1 molar and pH <2, the dominant aqueous phase is HgCl42- while non polar HgCl2 will partition into the octanol phase. Since HgCl42- has a stronger ionic

  12. Temperature Dependence and Recoil-free Fraction Effects in Olivines Across the Mg-Fe Solid Solution

    NASA Technical Reports Server (NTRS)

    Sklute, E. C.; Rothstein, Y.; Dyar, M. D.; Schaefer, M. W.; Menzies, O. N.; Bland, P. A.; Berry, F. J.

    2005-01-01

    Olivine and pyroxene are the major ferromagnesian minerals in most meteorite types and in mafic igneous rocks that are dominant at the surface of the Earth. It is probable that they are the major mineralogical components at the surface of any planetary body that has undergone differentiation processes. In situ mineralogical studies of the rocks and soils on Mars suggest that olivine is a widespread mineral on that planet s surface (particularly at the Gusev site) and that it has been relatively unaffected by alteration. Thus an understanding of the characteristics of Mossbauer spectra of olivine is of great importance in interpreting MER results. However, variable temperature Mossbauer spectra of olivine, which are needed to quantify recoil-free fraction effects and to understand the temperature dependence of olivine spectra, are lacking in the literature. Thus, we present here a study of the temperature dependence and recoil-free fraction of a series of synthetic olivines.

  13. Deuterium implantation in magnetic garnets

    SciTech Connect

    Wilts, C.H.; Urai, A.

    1988-11-01

    The magnetic effects of deuterium implantation and subsequent annealing were measured in Gd, Tm, and Ga-substituted yttrium iron garnet films for comparison with measurements made earlier with hydrogen implantation. Implantation energy was 60 keV and the dose ranged from 0.5 to 3 x 10/sup 16/ ions/cm/sup 2/ for D/sup +//sub 2/ ions, as compared to an energy of 120 keV and a dose from 0.3 to 4 x 10/sup 16/ ions/cm/sup 2/ for H/sup +//sub 2/ in the earlier study. Measurements made included x-ray rocking curves and ferromagnetic resonance spectra measured at 9.5 GHz. For all doses the implanted layer remained crystalline. Implanted layer thickness was about 4200 A and peak strain occured at a depth of 2600 A. Peak strain increased monotonically, but departed from a linear relation with dose. For the highest dose, the peak strain was 2.5%. Relaxation of strain with annealing was intermediate between that found earlier for hydrogen and neon implantation. As compared to all other implant elements, both deuterium and hydrogen show a large anomalous magnetic anisotropy which can exceed 10 000 Oe for either ion. The absence of this effect for He, Ne, and other ions supports the conjecture that the effect is chemical and related to electronic bonding rather than strain or disorder. The anomalous anisotropy for deuterium decreases and shifts location with annealing. It has largely disappeared at temperatures of 300--350 /sup 0/C. The shape of the profile is consistent with the hypothesis that the shift in anisotropy is associated with diffusion of the deuterium atoms to the surface of the garnet film. At the highest dose, crystalline damage in the region of highest strain is sufficient to radically alter magnetic properties and in particular reduces even the excess anisotropy so that a two-peak profile results until modified by annealing.

  14. Dependence of the Broad Absorption Line Quasar Fraction on Radio Luminosity

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Dai, Xinyu; Sivakoff, Gregory R.

    2008-11-01

    We find that the fraction of classical broad absorption line quasars (BALQSOs) among the FIRST radio sources in the Sloan Data Release 3, is 20.5+ 7.3-5.9% at the faintest radio powers detected (L1.4 GHz ~ 1032 erg s-1), and rapidly drops to lesssim8% at L1.4 GHz ~ 3 × 1033 erg s-1. Similarly, adopting the broader absorption index (AI) definition of Trump et al., we find the fraction of radio BALQSOs to be 44+ 8.1-7.8%, reducing to 23.1+ 7.3-6.1% at high luminosities. While the high fraction at low radio power is consistent with the recent near-IR estimates by Dai et al., the lower fraction at high radio powers is intriguing and confirms previous claims based on smaller samples. The trend is independent of the redshift range, the optical and radio flux selection limits, or the exact definition of a radio match. We also find that at fixed optical magnitude, the highest bins of radio luminosity are preferentially populated by non-BALQSOs, consistent with the overall trend. We do find, however, that those quasars identified as AI-BALQSOs but not under the classical definition do not show a significant drop in their fraction as a function of radio power, further supporting independent claims that these sources, characterized by lower equivalent width, may represent an independent class from the classical BALQSOs. We find the balnicity index, a measure of the absorption trough in BALQSOs, and the mean maximum wind velocity to be roughly constant at all radio powers. We discuss several plausible physical models which may explain the observed fast drop in the fraction of the classical BALQSOs with increasing radio power, although none is entirely satisfactory. A strictly evolutionary model for the BALQSO and radio emission phases requires a strong fine-tuning to work, while a simple geometric model, although still not capable of explaining polar BALQSOs and the paucity of FRII BALQSOs, is statistically successful in matching the data if part of the apparent radio

  15. Frequency dependence of complex moduli of brain tissue using a fractional Zener model

    NASA Astrophysics Data System (ADS)

    Kohandel, M.; Sivaloganathan, S.; Tenti, G.; Darvish, K.

    2005-06-01

    Brain tissue exhibits viscoelastic behaviour. If loading times are substantially short, static tests are not sufficient to determine the complete viscoelastic behaviour of the material, and dynamic test methods are more appropriate. The concept of complex modulus of elasticity is a powerful tool for characterizing the frequency domain behaviour of viscoelastic materials. On the other hand, it is well known that classical viscoelastic models can be generalized by means of fractional calculus to describe more complex viscoelastic behaviour of materials. In this paper, the fractional Zener model is investigated in order to describe the dynamic behaviour of brain tissue. The model is fitted to experimental data of oscillatory shear tests of bovine brain tissue to verify its behaviour and to obtain the material parameters.

  16. The dependence of optimal fractionation schemes on the spatial dose distribution

    NASA Astrophysics Data System (ADS)

    Unkelbach, Jan; Craft, David; Salari, Ehsan; Ramakrishnan, Jagdish; Bortfeld, Thomas

    2013-01-01

    We consider the fractionation problem in radiation therapy. Tumor sites in which the dose-limiting organ at risk (OAR) receives a substantially lower dose than the tumor, bear potential for hypofractionation even if the α/β-ratio of the tumor is larger than the α/β-ratio of the OAR. In this work, we analyze the interdependence of the optimal fractionation scheme and the spatial dose distribution in the OAR. In particular, we derive a criterion under which a hypofractionation regimen is indicated for both a parallel and a serial OAR. The approach is based on the concept of the biologically effective dose (BED). For a hypothetical homogeneously irradiated OAR, it has been shown that hypofractionation is suggested by the BED model if the α/β-ratio of the OAR is larger than α/β-ratio of the tumor times the sparing factor, i.e. the ratio of the dose received by the tumor and the OAR. In this work, we generalize this result to inhomogeneous dose distributions in the OAR. For a parallel OAR, we determine the optimal fractionation scheme by minimizing the integral BED in the OAR for a fixed BED in the tumor. For a serial structure, we minimize the maximum BED in the OAR. This leads to analytical expressions for an effective sparing factor for the OAR, which provides a criterion for hypofractionation. The implications of the model are discussed for lung tumor treatments. It is shown that the model supports hypofractionation for small tumors treated with rotation therapy, i.e. highly conformal techniques where a large volume of lung tissue is exposed to low but nonzero dose. For larger tumors, the model suggests hyperfractionation. We further discuss several non-intuitive interdependencies between optimal fractionation and the spatial dose distribution. For instance, lowering the dose in the lung via proton therapy does not necessarily provide a biological rationale for hypofractionation.

  17. Analysis of a class of boundary value problems depending on left and right Caputo fractional derivatives

    NASA Astrophysics Data System (ADS)

    Antunes, Pedro R. S.; Ferreira, Rui A. C.

    2017-07-01

    In this work we study boundary value problems associated to a nonlinear fractional ordinary differential equation involving left and right Caputo derivatives. We discuss the regularity of the solutions of such problems and, in particular, give precise necessary conditions so that the solutions are C1([0, 1]). Taking into account our analytical results, we address the numerical solution of those problems by the augmented -RBF method. Several examples illustrate the good performance of the numerical method.

  18. Influence of radiative processes on the ignition of deuterium-tritium plasma containing inactive impurities

    NASA Astrophysics Data System (ADS)

    Gus'kov, S. Yu.; Sherman, V. E.

    2016-08-01

    The degree of influence of radiative processes on the ignition of deuterium-tritium (DT) plasma has been theoretically studied as dependent on the content of inactive impurities in plasma. The analytic criterion of plasma ignition in inertial confinement fusion (ICF) targets is modified taking into account the absorption of intrinsic radiation from plasma in the ignition region. The influence of radiative processes on the DT plasma ignition has been analytically and numerically studied for plasma that contains a significant fraction of inactive impurities either as a result of DT fuel mixing with ICF target ablator material or as a result of using light metal DT-hydrides as solid noncryogenic fuel. It has been shown that the effect of the absorption of intrinsic radiation leads to lower impurity-induced increase in the ignition energy as compared to that calculated in the approximation of optically transparent ignition region.

  19. Time-Dependent Regional Myocardial Strains in Patients with Heart Failure with a Preserved Ejection Fraction

    PubMed Central

    Smith, Shane P.; Secomb, Timothy W.; Hong, Brian D.; Moulton, Michael J.

    2016-01-01

    Objectives. To better understand the etiology of HFpEF in a controlled human population, regional time-varying strains were computed using echocardiography speckle tracking in patients with heart failure with a preserved ejection fraction and normal subjects. Methods. Eleven normal volunteers and ten patients with echo-graded diastolic dysfunction and symptoms of heart failure were imaged with echocardiography and longitudinal, circumferential, and rotational strains were determined using speckle-tracking. Diastolic strain rate was also determined. Patient demographics and echo-derived flows, volumes, and pressures were recorded. Results. Peak longitudinal and circumferential strain was globally reduced in patients (p < 0.001), when compared to controls. The patients attained peak longitudinal and circumferential strain at a consistently later point in systole than controls. Rotational strains were not different in most LV regions. Early diastolic strain rate was significantly reduced in the patients (p < 0.001). LV mass and wall thickness were significantly increased in the patients; however ejection fraction was preserved and stroke volume was diminished (p < 0.001). Conclusions. This study shows that patients with HFpEF have reduced early diastolic strain rate and reduced peak strain that is regionally homogeneous and that they also utilize a longer fraction of systole to achieve peak axial strains. PMID:27042673

  20. Single crystal diamond detector measurements of deuterium-deuterium and deuterium-tritium neutrons in Joint European Torus fusion plasmas

    SciTech Connect

    Cazzaniga, C. Gorini, G.; Nocente, M.; Sundén, E. Andersson; Binda, F.; Ericsson, G.; Croci, G.; Grosso, G.; Cippo, E. Perelli; Tardocchi, M.; Giacomelli, L.; Rebai, M.; Griesmayer, E.; Kaveney, G.; Syme, B.; Collaboration: JET-EFDA Contributors

    2014-04-15

    First simultaneous measurements of deuterium-deuterium (DD) and deuterium-tritium neutrons from deuterium plasmas using a Single crystal Diamond Detector are presented in this paper. The measurements were performed at JET with a dedicated electronic chain that combined high count rate capabilities and high energy resolution. The deposited energy spectrum from DD neutrons was successfully reproduced by means of Monte Carlo calculations of the detector response function and simulations of neutron emission from the plasma, including background contributions. The reported results are of relevance for the development of compact neutron detectors with spectroscopy capabilities for installation in camera systems of present and future high power fusion experiments.

  1. Single crystal diamond detector measurements of deuterium-deuterium and deuterium-tritium neutrons in Joint European Torus fusion plasmas.

    PubMed

    Cazzaniga, C; Sundén, E Andersson; Binda, F; Croci, G; Ericsson, G; Giacomelli, L; Gorini, G; Griesmayer, E; Grosso, G; Kaveney, G; Nocente, M; Perelli Cippo, E; Rebai, M; Syme, B; Tardocchi, M

    2014-04-01

    First simultaneous measurements of deuterium-deuterium (DD) and deuterium-tritium neutrons from deuterium plasmas using a Single crystal Diamond Detector are presented in this paper. The measurements were performed at JET with a dedicated electronic chain that combined high count rate capabilities and high energy resolution. The deposited energy spectrum from DD neutrons was successfully reproduced by means of Monte Carlo calculations of the detector response function and simulations of neutron emission from the plasma, including background contributions. The reported results are of relevance for the development of compact neutron detectors with spectroscopy capabilities for installation in camera systems of present and future high power fusion experiments.

  2. Modelling of Deuterium Chemistry in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Roberts, Helen

    2005-08-01

    Several new multiply deuterated species have been detected over the past three years, including ND3 (van der Tak et al. 2002; Lis et al. 2002), CHD2OH, CD3OH (Parise et al. 2002, 2004), D2S (Vastel et al. 2003), HD2+ (Vastel et al. 2004) and D2CS (Marcelino et al. 2005). In addition, mono-deuterated species have been observed with abundances >10% of their un-deuterated analogues (e.g. CH2DOH observed by Parise et al. 2002; NH2D observed by Saito et al. 2000 and Hatchell 2003). These are remarkable results, given that the underlying abundance of deuterium in the local interstellar medium (ISM) is ˜10-5 times lower than that of hydrogen (Linsky 1998; Sonneborn et al. 2000).Such large enhancements in the abundances of deuterium-bearing molecules can either be due to gas-phase or to grain-surface fractionation. Grain-surface reactions are undoubtedly important in producing saturated species such as methanol, water, ammonia, and hydrogen sulphide. Water ice is observed to be abundant and ubiquitous throughout the ISM, and enhanced abundances of gas-phase NH3, CH3OH, H2CO and H2S (among others) are observed in warmer regions around protostars where grain mantles have evaporated.Recent observational and theoretical evidence suggests that the deuterium fractionation in star-forming regions is set by gas-phase and grain-surface reactions during the cold, dense pre-protostellar phase. For species which form on grain surfaces via H atom addition to CO, N, O and S, the deuterium fractionation on grains comes from the relative amounts of atomic D and H which are accreting from the gas. The observations of deuterated methanol and D2S require that the gas-phase atomic D/H ratio at the time the molecules formed was ≥ 0.1.This paper presents results from chemical models of the prestellar core phase of star formation, showing how this high atomic D/H ratio can be produced, and discusses how models can also be used to look at deuterium fractionation in the protostellar stages of

  3. Deuterium Gas Analysis by Residual Gas Analyzer

    NASA Astrophysics Data System (ADS)

    Das, B. K.; Shukla, R.; Das, R.; Shyam, A.; Rao, A. D. P.

    2012-11-01

    Hydrogen gas is generated by electrolysis method in a compact hydrogen generator. A simple procedure reduces handling and storage of hydrogen cylinders for laboratory applications. In such a system, we are producing deuterium gas from heavy water by electrolysis method. After production of the deuterium gas, we have checked the purity level of the outgoing deuterium from the electrolyser. The test was carried out in a high vacuum system in which one residual gas analyser (RGA) was mounted. The deuterium gas was inserted by one manual gas leak valve in to the vacuum system. In this study, the effect of the emission current of the RGA on the detection of the deuterium was performed. In this paper, we will discuss the detail analysis of the deuterium gas and the effect of the emission current on the partial pressure measurement.

  4. Deuterium Abundance in Consciousness and Current Cosmology

    NASA Astrophysics Data System (ADS)

    Rauscher, Elizabeth A.

    We utilize the deuterium-hydrogen abundances and their role in setting limits on the mass and other conditions of cosmogenesis and cosmological evolution. We calculate the dependence of a set of physical variables such as density, temperature, energy mass, entropy and other physical variable parameters through the evolution of the universe under the Schwarzschild conditions as a function from early to present time. Reconciliation with the 3°K and missing mass is made. We first examine the Schwarzschild condition; second, the geometrical constraints of a multidimensional Cartesian space on closed cosmologies, and third we will consider the cosmogenesis and evolution of the universe in a multidimensional Cartesian space, obeying the Schwarzschild condition. Implications of this model for matter creation are made. We also examine experimental evidence for closed versus open cosmologies; x-ray detection of the "missing mass" density. Also the interstellar deuterium abundance, along with the value of the Hubble constant set a general criterion on the value of the curvature constant, k. Once the value of the Hubble constant, H is determined, the deuterium abundance sets stringent restrictions on the value of the curvature constant k by an detailed discussion is presented. The experimental evidences for the determination of H and the primary set of coupled equations to determine D abundance is given. 'The value of k for an open, closed, or flat universe will be discussed in terms of the D abundance which will affect the interpretation of the Schwarzschild, black hole universe. We determine cosmology solutions to Einstein's field obeying the Schwarzschild solutions condition. With this model, we can form a reconciliation of the black hole, from galactic to cosmological scale. Continuous creation occurs at the dynamic blackhole plasma field. We term this new model the multiple big bang or "little whimper model". We utilize the deuteriumhydrogen abundances and their role in

  5. The Diffusion of Muonic Deuterium Atoms in Deuterium Gas.

    NASA Astrophysics Data System (ADS)

    Kraiman, James Brian

    Negative muons were brought to rest in a target array consisting of 30-50 parallel plastic foils coated with Au which were separated by a few mm. The interstitial volumes between the foils were filled with deuterium gas at pressures from 0.094 bar to 1.52 bar. Muons which stopped in the deuterium formed mud atoms, which subsequently diffused through the gas until either the muon decayed or the mud atom struck a foil surface. For mud atoms impinging upon the Au layer, the muon would transfer to an Au atom, resulting in the formation of a mu Au atom in a highly excited state. De-excitation to the 1S ground state resulted in emission of characteristic muonic Au x rays, and after the muon was absorbed by the Au nucleus, the emission of Pt gamma rays. These transfer photons were detected by one of four germanium x-ray detectors adjacent to the target vessel. Analysis of the time distributions formed by collecting delayed transfer events for several sets of experimental conditions yielded information on the diffusion process of mud atoms in deuterium gas. The initial speed distribution of the mud atoms upon reaching the 1S state is described reasonably well by a Maxwellian speed distribution of mean energy 3KT/2 = 1.8 +/- 0.1 eV. The theoretical scattering cross sections for the reaction mud + d to mud + d calculated by Bubak and Faifman agree well with this experiment when the effects of molecular scattering are approximated by multiplying the nuclear cross sections by a factor of about two. It was found that a factor of 2.10 for center of mass collision energies greater than 0.30 eV, and 2.30 for collision energies less than 0.30 eV provided a good fit to the experimental data.

  6. Low deuterium content of Lake Vanda, Antarctica

    USGS Publications Warehouse

    Ragotzkie, R.A.; Friedman, I.

    1965-01-01

    Lake Vanda in Victoria Land, Antarctica, is permanently ice-covered and permanently stratified, with warm, salty water near the bottom. Deuterium analyses of lake water from several levels indicate that the lake has a low deuterium content, and that it is stratified with respect to this isotope. This low deuterium content supports the evidence from the lake's ionic content that the saline layer is not of marine origin, and it indicates that evaporation from the ice surface has taken place. The stratification of the lake with respect to deuterium suggests that the upper and lower layers of water were formed at different times from different sources of glacial melt water.

  7. Order or chaos in Boolean gene networks depends on the mean fraction of canalizing functions

    NASA Astrophysics Data System (ADS)

    Karlsson, Fredrik; Hörnquist, Michael

    2007-10-01

    We explore the connection between order/chaos in Boolean networks and the naturally occurring fraction of canalizing functions in such systems. This fraction turns out to give a very clear indication of whether the system possesses ordered or chaotic dynamics, as measured by Derrida plots, and also the degree of order when we compare different networks with the same number of vertices and edges. By studying also a wide distribution of indegrees in a network, we show that the mean probability of canalizing functions is a more reliable indicator of the type of dynamics for a finite network than the classical result on stability relating the bias to the mean indegree. Finally, we compare by direct simulations two biologically derived networks with networks of similar sizes but with power-law and Poisson distributions of indegrees, respectively. The biologically motivated networks are not more ordered than the latter, and in one case the biological network is even chaotic while the others are not.

  8. Fractionation and reconstitution of factors required for accurate transcription of mammalian ribosomal RNA genes: identification of a species-dependent initiation factor.

    PubMed Central

    Mishima, Y; Financsek, I; Kominami, R; Muramatsu, M

    1982-01-01

    Mouse and human cell extracts (S100) can support an accurate and efficient transcription initiation on homologous ribosomal RNA gene (rDNA) templates. The cell extracts were fractionated with the aid of a phosphocellulose column into four fractions (termed A, B, C and D), including one containing a major part of the RNA polymerase I activity. Various reconstitution experiments indicate that fraction D is an absolute requirement for the correct and efficient transcription initiation by RNA polymerase I on both mouse and human genes. Fraction B effectively suppresses random initiation on these templates. Fraction A appears to further enhance the transcription which takes place with fractions C and D. Although fractions A, B and C are interchangeable between mouse and human extracts, fraction D is not; i.e. initiation of transcription required the presence of a homologous fraction D for both templates. The factor(s) in fraction D, however, is not literally species-specific, since mouse D fraction is capable of supporting accurate transcription initiation on a rat rDNA template in the presence of all the other fractions from human cell extract under the conditions where human D fraction is unable to support it. We conclude from these experiments that a species-dependent factor in fraction D plays an important role in the initiation of rDNA transcription in each animal species. Images PMID:7177852

  9. Dependence of microwave absorption properties on ferrite volume fraction in MnZn ferrite/rubber radar absorbing materials

    NASA Astrophysics Data System (ADS)

    Gama, Adriana M.; Rezende, Mirabel C.; Dantas, Christine C.

    2011-11-01

    We report the analysis of measurements of the complex magnetic permeability ( μr) and dielectric permittivity ( ɛr) spectra of a rubber radar absorbing material (RAM) with various MnZn ferrite volume fractions. The transmission/reflection measurements were carried out in a vector network analyzer. Optimum conditions for the maximum microwave absorption were determined by substituting the complex permeability and permittivity in the impedance matching equation. Both the MnZn ferrite content and the RAM thickness effects on the microwave absorption properties, in the frequency range of 2-18 GHz, were evaluated. The results show that the complex permeability and permittivity spectra of the RAM increase directly with the ferrite volume fraction. Reflection loss calculations by the impedance matching degree (reflection coefficient) show the dependence of this parameter on both thickness and composition of RAM.

  10. Carbon and hydrogen isotope fractionation during nitrite-dependent anaerobic methane oxidation by Methylomirabilis oxyfera

    NASA Astrophysics Data System (ADS)

    Rasigraf, Olivia; Vogt, Carsten; Richnow, Hans-Hermann; Jetten, Mike S. M.; Ettwig, Katharina F.

    2012-07-01

    Anaerobic oxidation of methane coupled to nitrite reduction is a recently discovered methane sink of as yet unknown global significance. The bacteria that have been identified to carry out this process, Candidatus Methylomirabilis oxyfera, oxidize methane via the known aerobic pathway involving the monooxygenase reaction. In contrast to aerobic methanotrophs, oxygen is produced intracellularly and used for the activation of methane by a phylogenetically distinct particulate methane monooxygenase (pMMO). Here we report the fractionation factors for carbon and hydrogen during methane oxidation by an enrichment culture of M. oxyfera bacteria. In two separate batch incubation experiments with different absolute biomass and methane contents, the specific methanotrophic activity was similar and the progressive isotope enrichment identical. Headspace methane was consumed up to 98% with rates showing typical first order reaction kinetics. The enrichment factors determined by Rayleigh equations were -29.2 ± 2.6‰ for δ13C (εC) and -227.6 ± 13.5‰ for δ2H (εH), respectively. These enrichment factors were in the upper range of values reported so far for aerobic methanotrophs. In addition, two-dimensional specific isotope analysis (Λ = ( α H - 1 - 1)/( α C - 1 - 1)) was performed and also the determined Λ value of 9.8 was within the range determined for other aerobic and anaerobic methanotrophs. The results showed that in contrast to abiotic processes biological methane oxidation exhibits a narrow range of fractionation factors for carbon and hydrogen irrespective of the underlying biochemical mechanisms. This work will therefore facilitate the correct interpretation of isotopic composition of atmospheric methane with implications for modeling of global carbon fluxes.

  11. Mass-dependent and -independent fractionation of Fe isotopes in magnetotactic bacteria

    NASA Astrophysics Data System (ADS)

    Amor, M.; Busigny, V.; Louvat, P.; Gelabert, A.; Cartigny, P.; Durand-Dubief, M.; Ona-Nguema, G.; Alphandéry, E.; Chebbi, I.; Guyot, F. J.

    2016-12-01

    Magnetotactic bacteria (MTB) perform biomineralization of intracellular magnetite (Fe3O4) nanoparticles. Although they may be among the oldest microorganisms capable of biomineralization on Earth, identification of their activity in the geological record remains poorly resolved because of the lack of reliable signatures. Here, we determined Fe isotope fractionation by the magnetotactic bacterium Magnetospirillum magneticum strain AMB-1 to better understand Fe cycling in MTB and provide new signatures of the contribution of MTB to iron geochemistry. AMB-1 strain was cultivated with either Fe(III)-quinate or Fe(II)-ascorbate as Fe sources. Iron isotope composition of Fe sources, bacterial growth media after AMB-1 cultures, bacterial lysates (corresponding to AMB-1 cells devoid of magnetite) and magnetite samples were analyzed by MC-ICP-MS after column chromatography. In the two culture conditions, growth media after AMB-1 cultures were enriched in light Fe isotopes relative to Fe sources. Two distinct bacterial Fe reservoirs were characterized in AMB-1: (1) magnetite enriched in the light Fe isotopes by 1.5 to 2.5‰ in δ56Fe relative to Fe sources, and (2) lysate enriched in the heavy Fe isotopes by 0.3 to 0.8‰ relative to Fe sources. More importantly, mass-independent fractionations in odd (57Fe) but not in even isotopes (54Fe, 56Fe and 58Fe) were observed for the first time, highlighting a magnetic isotope effect. Magnetite samples were significantly enriched in 57Fe by 0.23‰ relative to 54Fe, 56Fe and 58Fe. Based on our results, we propose a model for Fe cycling and magnetite biomineralization in AMB-1, and propose to use this specific mass-independent signature of Fe isotopes to evaluate the contribution of MTB to the iron biogeochemistry of recent and ancient environmental samples.

  12. Deuterium accelerator experiments for APT.

    SciTech Connect

    Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

  13. Was Venus wet? Deuterium reconsidered

    NASA Technical Reports Server (NTRS)

    Grinspoon, David H.

    1987-01-01

    The ratio of deuterium to hydrogen on Venus has been accepted as proof of a wetter, more earth-like part on that planet. However, the present-day water abundance and the nonthermal hydrogen escape flux on Venus imply that hydrogen is in a steady state and that a hydrogen source, most likely cometary infall, is present. An alternative interpretation of the D/H ratio is offered, in which the measured value is consistent with a steady-state evolution over the age of the solar system. No past water excess is required to explain the isotopic data.

  14. Estimation of intervention effects using recurrent event time data in the presence of event dependence and a cured fraction.

    PubMed

    Xu, Ying; Lam, K F; Cheung, Yin Bun

    2014-06-15

    Recurrent event data with a fraction of subjects having zero event are often seen in randomized clinical trials. Those with zero event may belong to a cured (or non-susceptible) fraction. Event dependence refers to the situation that a person's past event history affects his future event occurrences. In the presence of event dependence, an intervention may have an impact on the event rate in the non-cured through two pathways-a primary effect directly on the outcome event and a secondary effect mediated through event dependence. The primary effect combined with the secondary effect is the total effect. We propose a frailty mixture model and a two-step estimation procedure for the estimation of the effect of an intervention on the probability of cure and the total effect on event rate in the non-cured. A summary measure of intervention effects is derived. The performance of the proposed model is evaluated by simulation. Data on respiratory exacerbations from a randomized, placebo-controlled trial are re-analyzed for illustration.

  15. Threshold character of temperatures on deuterium thermal desorption in Mg-V composite grown atom-by-atom

    NASA Astrophysics Data System (ADS)

    Neklyudov, I. M.; Morozov, O. M.; Kulish, V. G.; Zhurba, V. I.; Galitskiy, A. G.; Lomino, N. S.; Kuprin, A. S.; Ovcharenko, V. D.; Reshetnyak, E. N.

    2012-08-01

    The plasma evaporation-sputtering method was applied to make composite materials of the Mg-V system. The ion-implanted deuterium desorption temperature variations as a function of the component concentration were studied. It has been established that, by introducing vanadium into magnesium, the deuterium desorption temperature can be appreciably decreased (to 300-330 K) in comparison with the case of deuterium desorption from magnesium (~800 K). A step-like form of the curve of deuterium desorption temperature evidences on the presence of two different structure states of the Mg-V system depending on the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions formed, in the process of composite making and annealing, by the insoluble component (vanadium) atoms providing the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through the surface barrier). A necessary high diffusion mobility of deuterium is provided by the amorphous state of Mg83+xVx samples. The deuterium desorption data obtained on the example of Mg-V and Mg-Zr composites provide support for further research into hydrogen storage materials containing low-soluble chemical elements in the alloy components.

  16. Fundamental aspects of deuterium retention in tungsten at high flux plasma exposure

    SciTech Connect

    Ogorodnikova, O. V.

    2015-08-21

    An effect of enhanced trapping of deuterium in tungsten at high flux was discovered. It was shown analytically and confirmed experimentally that the deuterium trapping in a presence of high density of defects in tungsten (W) depends on the ion energy and ion flux. Newly developed analytical model explains experimentally observed discrepancy of deuterium trapping at radiation-induced defects in tungsten at different ion fluxes that significantly improves a prediction of hydrogen isotope accumulation in different plasma devices, including ITER and DEMO. The developed model can be used for many system of hydrogen in a metal in both normal and extreme environments (high fluxes, elevated temperatures, neutron irradiation, etc.). This new model allows, for the first time, to validate density function theory (DFT) predictions of multiple occupation of a defect with deuterium against experimental data that bridge the gap in length and time scale between DFT calculations and experiments. By comparing first-principle calculations based on DFT and semi-empirical “adsorption model,” it was proved that the mechanism of hydrogen isotope trapping in a vacancy cluster is similar to a chemisorption on a surface. Binding energies of deuterium with different types of defects in W were defined. Moreover, the surface barrier of deuterium to be chemisorbed on a clean W surface was found to be less than 1 eV and kinetics of deuterium release is limited by de-trapping from defects rather than to be limited by surface effects.

  17. Fundamental aspects of deuterium retention in tungsten at high flux plasma exposure

    NASA Astrophysics Data System (ADS)

    Ogorodnikova, O. V.

    2015-08-01

    An effect of enhanced trapping of deuterium in tungsten at high flux was discovered. It was shown analytically and confirmed experimentally that the deuterium trapping in a presence of high density of defects in tungsten (W) depends on the ion energy and ion flux. Newly developed analytical model explains experimentally observed discrepancy of deuterium trapping at radiation-induced defects in tungsten at different ion fluxes that significantly improves a prediction of hydrogen isotope accumulation in different plasma devices, including ITER and DEMO. The developed model can be used for many system of hydrogen in a metal in both normal and extreme environments (high fluxes, elevated temperatures, neutron irradiation, etc.). This new model allows, for the first time, to validate density function theory (DFT) predictions of multiple occupation of a defect with deuterium against experimental data that bridge the gap in length and time scale between DFT calculations and experiments. By comparing first-principle calculations based on DFT and semi-empirical "adsorption model," it was proved that the mechanism of hydrogen isotope trapping in a vacancy cluster is similar to a chemisorption on a surface. Binding energies of deuterium with different types of defects in W were defined. Moreover, the surface barrier of deuterium to be chemisorbed on a clean W surface was found to be less than 1 eV and kinetics of deuterium release is limited by de-trapping from defects rather than to be limited by surface effects.

  18. Energy-dependent and Fraction Specific Response of Pyrogenic Dissolved Organic Carbon during Photodegradation

    NASA Astrophysics Data System (ADS)

    Leonce, B. C.; Harvey, O. R.; Liu, Y.; Kuo, L. J.

    2016-12-01

    The extent that pyrogenic dissolved organic carbon (Py-DOC) photodegrades in aqueous environments is a function of pyrolysis conditions, feedstock chemistry, aqueous conditions and solar exposure. We exposed py-DOC extracted from wood and grass chars (pyrolyzed at 300 °C and 400 °C) to different levels of solar radiation to investigate the effects of energy input on, 1) the extent of photodegradation and 2) the chemical characteristics of photodegradation byproducts. Fluorescence spectral mapping revealed solar energy induced changes in three primary regions/fractions around excitation/emission wavelengths at 360/475nm (Region 1), 405/645nm (Region 2) and 400/675nm (Region 3) respectively. Responsiveness of py-DOC fractions to solar energy input followed the order Region 1> Region 2 > Region 3 with overall loss in fluorescence intensity (I/I0) being typically higher in wood- than grass-derived py-DOC. For example, a solar energy input of 40 kJ over an 8 h period resulted in up to 41%, 26% and 16% py-DOC fluorescence intensity loss in Region 1, 2 and 3 respectively - with intensity loss for wood-derived py-DOC averaging 10% more than grass-derived py-DOC extracted from chars produced at the same temperature. Ultra high resolution mass spectromoetry analysis also revealed significantly different chemical characteristics (e.g. molecular weights, O/C and H/C) of photodegradation by-products with energy input and py-DOC feedstock. Compared to the 0 kJ (dark) control, a 40 kJ energy input triggered a higher proportion of more oxidized, lower molecular weight photodegradation byproducts in the wood-derived py-DOC but had no effect on oxidation status or molecular weight distribution of grass-derived py-DOC. The presentation will focus on specific energy-driven changes, their associated reaction mechanisms, critical energy inputs and implications for biogeochemical cycling of photodegraded py-DOC in aquatic systems.

  19. Retention behavior in tungsten and molybdenum exposed to high fluences of deuterium ions in TPE

    SciTech Connect

    J.P. Sharpe; R.D. Kolasinski; M. Shimada; P. Calderoni; R.A. Causey

    2009-06-01

    The Tritium Plasma Experiment (TPE) has been used to investigate deuterium fuel retention behavior in tungsten and molybdenum– materials utilized for plasma-facing surfaces in some existing tokamak plasma devices and under consideration for future devices. Although several studies have been performed over the past several years on these metals, many issues remain unresolved, including for example blister formation mechanisms and correlation to surface conditions. In this study we expose several metal samples to deuterium ion fluences up to 1026 ions/m2 and measure retention behavior with thermal desportion spectroscopy. Fractional retention of up to 2.0×10-5 is found for W at 600 K, and Mo similarly retains deuterium at a fraction of 1.5×10-5 at 600 K. Blistering was found for W samples exposed at temperatures above 453 K, whereas blistering was not observed for Mo samples at any experiment temperature.

  20. On estimation of time-dependent attributable fraction from population-based case-control studies.

    PubMed

    Zhao, Wei; Chen, Ying Qing; Hsu, Li

    2017-01-18

    Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer.

  1. Clay Flocculation in the Presence of Suspended Silt: Independent or Dependent Fractions?

    NASA Astrophysics Data System (ADS)

    Tran, D. A.; Strom, K.

    2016-12-01

    This research examines whether or not mixes of clay and silt in suspension act and settle independent of each other. More specifically, we examine the following three questions: (1) does the presence of silt in suspension alter the size of mud flocs relative to a pure clay suspension of equivalent concentration? (2) can silt particles become bound inside clay flocs?; (3) and if silt is bound within flocs, how does this change the settling properties of the clay and silt? These questions are explored through a series of laboratory experiments in which the floc and silt size distributions are imaged and measured as a function of time within a turbulent suspension. These measurements are made with a floc imaging system without transferring the mixture to a separate chamber for analysis. The experiments are made with pure clay, with pure silt, and with different mixture ratio of silt and clay. The results show three primary conclusions. First, most of the silt fraction gets bound up within the floc aggregates. Second, the presence of the silt had no significant impact on floc size. And thirdly, the addition of silt within the flocs increased the particle settling velocity by approximately 50%. These results have potential implications for the modeling of suspended mud mixtures in rivers, estuaries, and turbidity currents.

  2. Fractionation and assimilation of Mg isotopes by fungi is species dependent.

    PubMed

    Fahad, Zaenab A; Bolou-Bi, Emile B; Köhler, Stephan J; Finlay, Roger D; Mahmood, Shahid

    2016-12-01

    Symbiotic ectomycorrhizal fungi mobilize nutrients from both organic and inorganic substrates and supply them to their host plants. Their role in mobilizing base cations and phosphorus from mineral substrates through weathering has received increasing attention in recent years but the processes involved remain to be elucidated. We grew selected ectomycorrhizal and nonmycorrhizal fungi in axenic systems containing mineral and organic substrates and examined their capacity to fractionate and assimilate stable isotopes of magnesium. The mycorrhizal fungi were significantly depleted in heavy isotopes with the lowest Δ(26) Mg values (the difference between δ(26) Mg in fungal tissue and δ(26) Mg in the substrate) compared with nonmycorrhizal fungi, when grown on mineral substrates containing granite particles. The ectomycorrhizal fungi accumulated significantly higher concentrations of Mg, K and P than the nonmycorrhizal fungi. There was a highly significant statistical relationship between δ(26) Mg tissue signature and mycelial concentration of Mg, with a clear separation between most ectomycorrhizal fungi and the nonmycorrhizal fungi. These results are consistent with the idea that ectomycorrhizal fungi have evolved efficient mechanisms to mobilize, transport and store Mg within their mycelia. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Vanadium hydride deuterium-tritium generator

    DOEpatents

    Christensen, Leslie D.

    1982-01-01

    A pressure controlled vanadium hydride gas generator to provide deuterium-tritium gas in a series of pressure increments. A high pressure chamber filled with vanadium-deuterium-tritium hydride is surrounded by a heater which controls the hydride temperature. The heater is actuated by a power controller which responds to the difference signal between the actual pressure signal and a programmed pressure signal.

  4. In vitro assessment of antineoplastic effects of deuterium depleted water.

    PubMed

    Soleyman-Jahi, Saeed; Zendehdel, Kazem; Akbarzadeh, Kambiz; Haddadi, Mahnaz; Amanpour, Saeid; Muhammadnejad, Samad

    2014-01-01

    In vitro, in vivo and clinical studies have demonstrated anti-cancer effects of deuterium depleted water (DDW). The nature of this agents action, cytotoxic or cytostatic, remains to be elucidated. We here aimed to address the point by examining effects on different cell lines. 3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) -based cytotoxicity analysis was conducted for human breast, stomach, colon, prostate cancer and glioblastoma multiforme cell lines as well as human dermal fibroblasts. The cell lines were treated with decreasing deuterium concentrations of DDW alone, paclitaxel alone and both. One way analysis of variance (ANOVA) was used for statistical analysis. Treatment with different deuterium concentrations of DDW alone did not impose any significant inhibitory effects on growth of cell lines. Paclitaxel significantly decreased the survival fractions of all cell lines. DDW augmented paclitaxel inhibitory effects on breast, prostate, stomach cancer and glioblastoma cell lines, with influence being more pronounced in breast and prostate cases. DDW per se does not appear to have inhibitory effects on the assessed tumor cell lines as well as normal fibroblasts. As an adjuvant, however, DDW augmented inhibitory effects of paclitaxel and thus it could be considered as an adjuvant to conventional anticancer agents in future trials.

  5. Lifetimes of Hydrogen and Deuterium Related Vibrational Modes in Silicon

    SciTech Connect

    Budde, M.; Luepke, G.; Chen, E; Zhang, X.; Tolk, N. H.; Feldman, L. C.; Tarhan, E.; Ramdas, A. K.; Stavola, M.

    2001-10-01

    Lifetimes of hydrogen and deuterium related stretch modes in Si are measured by high-resolution infrared absorption spectroscopy and transient bleaching spectroscopy. The lifetimes are found to be extremely dependent on the defect structure, ranging from 2 to 295 ps. Against conventional wisdom, we find that lifetimes of Si-D modes typically are longer than for the corresponding Si-H modes. The potential implications of the results on the physics of electronic device degradation are discussed.

  6. Deuterium depth distribution study in Yb

    NASA Astrophysics Data System (ADS)

    Guan, Xing-Cai; Lu, Yong-Kai; He, Hou-Jun; Zhao, Jiang-Tao; Wang, Qiang; Fang, Kai-Hong; Meng, Xuan; Wang, Tie-Shan; Kasagi, Jirohta

    2017-05-01

    The deuterium depth distribution for a , while beam implanted into ytterbium (Yb) at a temperature between 300 and 340 K was studied using the D(d,p)T reaction. By analyzing the proton yields, the deuterium depth distribution from the front surface to 500 nm depth was found. The results indicate that an equilibrium deuterium distribution region from the front surface to a depth approximately equal to the mean range of implanted deuterons was formed in Yb during the implantation. The deduced deuterium concentration in the equilibrium deuterium distribution region was D/Yb = 22%. Supported by National Natural Science Foundation of China (11275085, 11305080, 11405079 and 11505086), Fundamental Research Funds for Central University of China (lzujbky-2015-69 and lzujbky-2016-36).

  7. New insights into the rate dependence of sulfur isotope fractionation during dissimilatory sulfate reduction

    NASA Astrophysics Data System (ADS)

    Giannetta, M.; Druhan, J. L.; Sanford, R. A.

    2016-12-01

    The vast majority of experiments concerning the isotope partitioning of sulfate reducing bacteria (SRB) are conducted under artificially optimized growth conditions. In contrast, many natural environments supporting SRB reflect limited nutrient availability. In this study, we couple the cell-specific reduction rate of a common SRB to the characteristic partitioning of stable sulfur isotopes. However, our method is novel in that we regulate the addition of electron donor such that cell growth is minimized and cell-specific reduction rates are constant, thus simulating the low reactivity characteristic of natural conditions. Anoxic bioreactors containing equal amounts of Desulfovibrio vulgariswere continuously injected with formate to control the rate of dissimilatory sulfate reduction (DSR). Cell growth was minimized through two means, (1) a high initial culture density ensured the ratio of nutrients per cell was low; (2) the oxidation state of carbon in formate is unfavorable to cell biomass accumulation. Negligible cell growth was verified by flow cytometry. Four controlled DSR rates ranging from 0.32 to 1.8 µmole/hour exhibited fractionation factor (ɛ) values ranging from 9‰ to 4‰ over 1200 to 300 hours, respectively. These results demonstrate a unique value of ɛ for each rate of DSR, where larger S isotope partitioning is characteristic of a slower cell-specific rate of sulfate reduction. The results of this study provide a unique dataset that can be used to constrain variations in ɛ as a function of DSR rate. Specifically, the dataset offers a foundation to test recently proposed analytical models and predict variations in observed ɛ as a result of a multi-step reactive pathway. Based on these results, we suggest a novel rate expression for incorporation into reactive transport models. Such a rate law supports extrapolation of experimental behavior into natural conditions over modern to geologic timescales.

  8. Growth phase dependent hydrogen isotopic fractionation in alkenone-producing haptophytes

    NASA Astrophysics Data System (ADS)

    Wolhowe, M. D.; Prahl, F. G.; Probert, I.; Maldonado, M.

    2009-08-01

    Recent works have investigated use of the hydrogen isotopic composition of C37 alkenones (δDK37s, lipid biomarkers of certain haptophyte microalgae, as an independent paleosalinity proxy. We discuss herein the factors impeding the success of such an application and identify the potential alternative use of δDK37s measurements as a proxy for non-thermal, physiological stress impacts on the U37K' paleotemperature index. Batch-culture experiments with the haptophyte Emiliania huxleyi (CCMP 1742) were conducted to determine the magnitude and variability of the isotopic contrasts between individual C37 alkenones. Further experiments were conducted with Emiliania huxleyi (CCMP 1742) andGephyrocapsa oceanica (PZ3-1) to determine whether, and to what extent, δDK37s varies between the physiological extremes of nutrient-replete exponential growth and nutrient-depleted senescence. Emiliania huxleyi was observed to exhibit an isotopic contrast between di- and tri-unsaturated C37 alkenones (αK37:3-K37:2≈0.97) that is nearly identical to that reported recently by others for environmental samples. Furthermore, this contrast appears to be constant with growth stage. The consistency of the offset across different growth stages suggests that a single, well-defined value for αK37:3-K37:2 may exist and that its use in an isotope mass-balance will allow accurate determination of δD values for individual alkenones without having to rely on time- and labor-intensive chemical separations. The isotopic fractionation between growth medium and C37 alkenones was observed to increase dramatically upon the onset of nutrient-depletion-induced senescence, suggesting that δDK37s may serve as an objective tool for recognizing and potentially correcting, at least semi-quantitatively, for the effects of nutrient stress on U37K' temperature records.

  9. Impact-induced devolatilization and hydrogen isotopic fractionation of serpentine: implications for planetary accretion.

    PubMed

    Tyburczy, J A; Krishnamurthy, R V; Epstein, S; Ahrens, T J

    1990-05-01

    The degree of impact-induced devolatilization of nonporous serpentine, porous serpentine, and deuterium-enriched serpentine was investigated using two independent experimental methods, the gas recovery method and the solid recovery method, yielding consistent results. The gas recovery method enables determination of the chemical and hydrogen isotopic composition of the recovered gases. Experiments on deuterium-enriched serpentine unambiguously identify the samples as the source of the recovered gases, as opposed to other possible contaminants. For shock pressures near incipient devolatilization (Pinitial = 5.0 GPa), the hydrogen isotopic composition of the evolved gas is similar to that of the starting material. For higher shock pressures the bulk evolved gas is significantly lower in deuterium than the starting material. There is also significant reduction of H2O to H2 in gases recovered at higher shock pressures, probably caused by reaction of evolved H2O with the metal gas recovery fixture. The hydrogen isotopic fractionation between the evolved gas and the residual solid indicates nonequilibrium, kinetic control of gas-solid isotopic ratios. In contrast, gaseous H2O-H2 isotopic fractionation suggests high temperature (800-1300 K) isotopic equilibrium between the gaseous species, indicating initiation of devolatilization at sites of greater than average energy deposition (i.e., shear bands). Impact-induced hydrogen isotopic fractionation of hydrous silicates during accretion can affect the distribution of hydrogen isotopes of planetary bodies during accretion, leaving the interiors enriched in deuterium. The significance of this process for planetary development depends on the models used for extrapolation of the observed isotopic fractionation to devolatilizations greater than those investigated experimentally and assumptions about timing and rates of protoatmosphere loss, frequency of multiple impacts, and rates of gas-solid or gas-melt isotopic re

  10. Determination of mass-dependent isotopic fractionation of cerium and neodymium in geochemical samples by MC-ICPMS.

    PubMed

    Ohno, Takeshi; Hirata, Takafumi

    2013-01-01

    We have developed a new analytical method to determine the mass-dependent isotopic fractionations on Ce and Nd in geochemical samples. Mass discrimination effects on Ce and Nd were externally corrected by normalizing (149)Sm/(147)Sm and (153)Eu/(151)Eu, being 0.92124 and 1.0916, respectively based on an exponential law. The reproducibility of the isotopic ratio measurements on (142)Ce/(140)Ce, (146)Nd/(144)Nd and (148)Nd/(144)Nd were 0.08‰ (2SD, n = 25), 0.06‰ (2SD, n = 39) and 0.12‰ (2SD, n = 39), respectively. The present technique was applied to determine the variations of the Ce and Nd isotopic ratios for five geochemical reference materials (igneous rocks, JB-1a and JA-2; sedimentary rocks, JMn-1, JCh-1 and JDo-1). The resulting ratios for two igneous rocks (JB-1a and JA-2) and two sedimentary rocks (JMn-1 and JCh-1) did not vary significantly among the samples, whereas the Ce and Nd isotope ratios for the carbonate samples (JDo-1) were significantly higher than those for igneous and sedimentary rock samples. The 1:1 simple correlation between δ(142)Ce and δ(146)Nd indicates that there were no significant difference in the degree of isotopic fractionation between the Ce and Nd. This suggests that the isotopic fractionation for Ce found in the JDo-1 could be induced by geochemical or physicochemical processes without changing the oxidation status of Ce, since the redox-reaction can produce larger isotopic fractionation than the reactions without changing the oxidation state. The variations in the Ce and Nd isotope ratios for geochemical samples could provide new information concerning the physico-chemical processes of the sample formation.

  11. An Update on the Non-Mass-Dependent Isotope Fractionation under Thermal Gradient

    NASA Technical Reports Server (NTRS)

    Sun, Tao; Niles, Paul; Bao, Huiming; Socki, Richard; Liu, Yun

    2013-01-01

    Mass flow and compositional gradient (elemental and isotope separation) occurs when flu-id(s) or gas(es) in an enclosure is subjected to a thermal gradient, and the phenomenon is named thermal diffusion. Gas phase thermal diffusion has been theoretically and experimentally studied for more than a century, although there has not been a satisfactory theory to date. Nevertheless, for isotopic system, the Chapman-Enskog theory predicts that the mass difference is the only term in the thermal diffusion separation factors that differs one isotope pair to another,with the assumptions that the molecules are spherical and systematic (monoatomic-like structure) and the particle collision is elastic. Our previous report indicates factors may be playing a role because the Non-Mass Dependent (NMD) effect is found for both symmetric and asymmetric, linear and spherical polyatomic molecules over a wide range of temperature (-196C to +237C). The observed NMD phenomenon in the simple thermal-diffusion experiments demands quantitative validation and theoretical explanation. Besides the pressure and temperature dependency illustrated in our previous reports, efforts are made in this study to address issues such as the role of convection or molecular structure and whether it is a transient, non-equilibrium effect only.

  12. Culture-Dependent and -Independent Methods Capture Different Microbial Community Fractions in Hydrocarbon-Contaminated Soils

    PubMed Central

    Stefani, Franck O. P.; Bell, Terrence H.; Marchand, Charlotte; de la Providencia, Ivan E.; El Yassimi, Abdel; St-Arnaud, Marc; Hijri, Mohamed

    2015-01-01

    Bioremediation is a cost-effective and sustainable approach for treating polluted soils, but our ability to improve on current bioremediation strategies depends on our ability to isolate microorganisms from these soils. Although culturing is widely used in bioremediation research and applications, it is unknown whether the composition of cultured isolates closely mirrors the indigenous microbial community from contaminated soils. To assess this, we paired culture-independent (454-pyrosequencing of total soil DNA) with culture-dependent (isolation using seven different growth media) techniques to analyse the bacterial and fungal communities from hydrocarbon-contaminated soils. Although bacterial and fungal rarefaction curves were saturated for both methods, only 2.4% and 8.2% of the bacterial and fungal OTUs, respectively, were shared between datasets. Isolated taxa increased the total recovered species richness by only 2% for bacteria and 5% for fungi. Interestingly, none of the bacteria that we isolated were representative of the major bacterial OTUs recovered by 454-pyrosequencing. Isolation of fungi was moderately more effective at capturing the dominant OTUs observed by culture-independent analysis, as 3 of 31 cultured fungal strains ranked among the 20 most abundant fungal OTUs in the 454-pyrosequencing dataset. This study is one of the most comprehensive comparisons of microbial communities from hydrocarbon-contaminated soils using both isolation and high-throughput sequencing methods. PMID:26053848

  13. Ozonolysis of beta-pinene: temperature dependence of secondary organic aerosol mass fraction.

    PubMed

    Pathak, Ravikant; Donahue, Neil M; Pandis, Spyros N

    2008-07-15

    The SOA formation from beta-pinene ozonolysis at modest precursor concentrations (2-40 ppb) was investigated in the temperature range of 0-40 degrees C. The presence of inert seeds and high ozone concentrations is necessary to minimize losses of semivolatile vapors to the walls of the smog chamber. beta-pinene secondary organic aerosol production increases significantly with decreasing temperature. An increase by a factor of 2-3, depending on the reacted beta-pinene concentration, was observed as the temperature decreased from 40 to 0 degrees C. This increase appearsto be due mainly to the shifting of partitioning of the semivolatile SOA componentstoward the particulate phase and not to a change of the beta-pinene product distribution with temperature. The measurements are used to develop a new temperature-dependent parametrization for the four-component basis-set. The parametrization predicts much higher SOA production for beta-pinene ozonolysis for typical atmospheric conditions than the values that have been suggested by previous studies.

  14. Growth phase dependent hydrogen isotopic fractionation in alkenone-producing haptophytes

    NASA Astrophysics Data System (ADS)

    Wolhowe, M. D.; Prahl, F. G.; Probert, I.; Maldonado, M.

    2009-04-01

    Several recent works have investigated use of the hydrogen isotopic composition of C37 alkenones (δDK37s), lipid biomarkers of certain haptophyte microalgae, as an independent paleosalinity proxy. We discuss herein the factors impeding the success of such an application and identify the potential alternative use of δDK37s measurements as a proxy for non-thermal, physiological stress impacts on the U37K' paleotemperature index. Batch-culture experiments with the haptophyte Emiliania huxleyi (CCMP 1742) were conducted to determine the magnitude and variability of the isotopic contrasts between individual C37 alkenones, an analytical impediment to the use of δDK37s in any paleoceanographic context. Further experiments were conducted with Emiliania huxleyi (CCMP 1742) and Gephyrocapsa oceanica (PZ3-1) to determine whether, and to what extent, δDK37s varies between the physiological extremes of nutrient-replete exponential growth and nutrient-depleted senescence, the basis for our proposed use of the measurement as an indicator of stress. Emiliania huxleyi exhibited an isotopic contrast between di- and tri-unsaturated C37 alkenones (αK37:3-K37:2≈0.97) that is nearly identical to that reported recently by others for environmental samples. Furthermore, this contrast appears to be constant with growth stage. The consistency of the offset across different growth stages suggests that a single, well-defined value for αK37:3-K37:2 exists and that its use in an isotope mass-balance will allow accurate determination of δD values for individual alkenones without having to rely on time- and labor-intensive chemical separations. The isotopic fractionation between growth medium and C37 alkenones was observed to increase dramatically upon the onset of nutrient-depletion-induced senescence, suggesting that δDK37s may serve as an objective tool for recognizing and potentially correcting, at least semi-quantitatively, for the effects of nutrient stress on U37K' temperature

  15. Ion Channeling Analysis of Gallium Nitride Implanted with Deuterium

    SciTech Connect

    Myers, S.M.; Wampler, W.R.

    1998-12-23

    Ion channeling and transmission electron microscopy were used to examine the microstructure of GaN implanted with deuterium (D) at high (>1 at. %) and low (< 0.1 at. %) D concentrations. At high concentrations, bubbles and basal-plane stacking faults were observed. Ion channeling showed the D was disordered relative to the GaN lattice, consistent with precipitation of D2 into bubbles. At low D concentrations, bubbles and stacking faults are absent and ion channeling shows that a large fraction of the D occupies sites near the center of the c-axis channel.

  16. Temperature dependence of oxygen isotope fractionation in coccolith calcite: A culture and core top calibration of the genus Calcidiscus

    NASA Astrophysics Data System (ADS)

    Candelier, Yaël; Minoletti, Fabrice; Probert, Ian; Hermoso, Michaël

    2013-01-01

    Reconstructions of seawater temperature based on measurement of oxygen isotopes in carbonates mostly derive from analyses of bulk sediment samples or manually picked foraminifera. The temperature dependence of 18O fractionation in biogenic calcite was first established in the 1950s and the objective of the present study is to re-evaluate this temperature dependence in coccolith calcite with a view to developing a robust proxy for reconstructing "vital effect"-free δ18O values. Coccoliths, the micron-sized calcite scales produced by haptophyte algae that inhabit surface mixed-layer waters, are a dominant component of pelagic sediments. Despite their small size, recent methodological developments allow species-specific separation (and thus isotopic analysis) of coccoliths from bulk sediments. This is especially the case for Calcidiscus spp. coccoliths that are relatively easy to separate out from other sedimentary carbonate grains including other coccolith taxa. Three strains of coccolithophores belonging to the genus Calcidiscus and characterised by distinct cell and coccolith diameters were grown in the laboratory under controlled temperature conditions over a range from 15 to 26 °C. The linear relationship that relates 18O fractionation to the temperature of calcification is here calibrated by the equation: T [°C] = -5.83 × (δ18OCalcidiscus - δ18Omedium) + 4.83 (r = 0.98). The slope of the regression is offset of ˜-1.1‰ from that of equilibrium calcite. This offset corresponds to the physiologically induced isotopic effect or "vital effect". The direction of fractionation towards light isotopic values is coherent with previous reports, but the intensity of fractionation in our dilute batch cultures was significantly closer to equilibrium compared to previously reported offset values. No significant isotopic difference was found between the three Calcidiscus coccolithophores, ruling out a control of the cell geometry on oxygen isotope fractionation within

  17. A high field optical-pumping spin-exchange polarized deuterium source

    SciTech Connect

    Coulter, K.P.; Holt, R.J.; Kinney, E.R.; Kowalczyk, R.S.; Poelker, M.; Potterveld, D.H.; Young, L.; Zeidman, B. ); Toporkov, D. . Inst. Yadernoj Fiziki)

    1992-01-01

    Recent results from a prototype high field optical-pumping spin-exchange polarized deuterium source are presented. Atomic polarization as high as 62% have been observed with an intensity of 6.3 [times] 10[sup 17] atoms-sec[sup [minus]1] and 65% dissociation fraction.

  18. Not all 2 gray radiation prescriptions are equivalent: Cytotoxic effect depends on delivery sequences of partial fractionated doses

    SciTech Connect

    Lin, P.-S. . E-mail: plin@vcu.edu; Wu, Andrew

    2005-10-01

    Purpose: To test whether or not the commonly prescribed daily dose of 2 Gy (whole fraction), when delivered as various partial fraction (PF) dose sequences simulating clinical treatment fields, produces equal biologic effects. Methods and Materials: Eleven actively proliferating cell lines derived from human and animal tissues were used in this study. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and clonogenic assays were used to determine the radiation effects on cell proliferation and survival, respectively. The 2 Gy dose was divided into 2 or more PFs for delivery to simulate the delivery of clinical treatment fields. Most irradiation sequences contained two parts consisting of at least 1 small PF, denoted by S which was 0.5 Gy or less, and a large PF, denoted by L which was 1 Gy or more. Irradiation schemes were designed to include the following conditions: (a) the 2 Gy dose divided into combinations of an L-dose and one or more S-doses; (b) the L-dose given either before or after the S-doses; and (c) delivery of all partial fractions within a fixed total time. Results: Significant differences in biologic effect were observed between sequences in which the L-dose was given before or after the S-doses in both the MTT and clonogenic assays. Nearly all the latter schemes, that is S-L, produced greater cytotoxic effects than the L-S schemes. Conclusions: These data demonstrate that the biologic effects of 2 Gy may differ in different clinical settings depending on the size and sequence of the partial fractions. The variation between cytotoxic effects is likely a result of the combination of low-dose hyper-radiosensitivity (HRS) and higher-dose increased radioresistance (IRR) effects established recently. We suggest that to ensure the optimal biologic effect of a prescribed dose of 2 Gy clinically, it is critical to consider the sequence in which the treatment fields are delivered when partial fractions of different sizes are used.

  19. Fractionating the neural substrates of transitive reasoning: task-dependent contributions of spatial and verbal representations.

    PubMed

    Prado, Jérôme; Mutreja, Rachna; Booth, James R

    2013-03-01

    It has long been suggested that transitive reasoning relies on spatial representations in the posterior parietal cortex (PPC). Previous neuroimaging studies, however, have always focused on linear arguments, such as "John is taller than Tom, Tom is taller than Chris, therefore John is taller than Chris." Using functional magnetic resonance imaging (fMRI), we demonstrate here that verbal representations contribute to transitive reasoning when it involves set-inclusion relations (e.g., "All Tulips are Flowers, All Flowers are Plants, therefore All Tulips are Plants"). In the present study, such arguments were found to engage verbal processing regions of the left inferior frontal gyrus (IFG) and left PPC that were identified in an independent localizer task. Specifically, activity in these verbal regions increased as the number of relations increased in set-inclusion arguments. Importantly, this effect was specific to set-inclusion arguments because left IFG and left PPC were not differentially engaged when the number of relations increased in linear arguments. Instead, such an increase was linked to decreased activity in a spatial processing region of the right PPC that was identified in an independent localizer task. Therefore, both verbal and spatial representations can underlie transitive reasoning, but their engagement depends upon the structure of the argument.

  20. Fractionating the Neural Substrates of Transitive Reasoning: Task-Dependent Contributions of Spatial and Verbal Representations

    PubMed Central

    Mutreja, Rachna; Booth, James R.

    2013-01-01

    It has long been suggested that transitive reasoning relies on spatial representations in the posterior parietal cortex (PPC). Previous neuroimaging studies, however, have always focused on linear arguments, such as “John is taller than Tom, Tom is taller than Chris, therefore John is taller than Chris.” Using functional magnetic resonance imaging (fMRI), we demonstrate here that verbal representations contribute to transitive reasoning when it involves set-inclusion relations (e.g., “All Tulips are Flowers, All Flowers are Plants, therefore All Tulips are Plants”). In the present study, such arguments were found to engage verbal processing regions of the left inferior frontal gyrus (IFG) and left PPC that were identified in an independent localizer task. Specifically, activity in these verbal regions increased as the number of relations increased in set-inclusion arguments. Importantly, this effect was specific to set-inclusion arguments because left IFG and left PPC were not differentially engaged when the number of relations increased in linear arguments. Instead, such an increase was linked to decreased activity in a spatial processing region of the right PPC that was identified in an independent localizer task. Therefore, both verbal and spatial representations can underlie transitive reasoning, but their engagement depends upon the structure of the argument. PMID:22275478

  1. Deuterium and the stellar birthline

    NASA Technical Reports Server (NTRS)

    Stahler, Steven W.

    1988-01-01

    A series of simplified evolutionary calculations are used to show that deuterium burning acts as an effective thermostat in low-mass protostars over a plausible range of initial conditions and mass accretion rates. The thermostat keeps the central temperature of the accreting hydrostatic core close to 10 to the 6th K, and thereby tightly constrains the core's mass-radius relation. This relation, when combined with premain-sequence evolutionary tracks, yields a theoretical birthline or upper envelope for young stars in the H-R diagram which maintains excellent agreement with observations of T Tauri stars in nearby molecular cloud complexes. This derivation of the birthline helps to explain its insensitivity to protostellar collapse conditions. The calculations indicate that the birthline will be little affected by the inclusion of rotation as long as the newly visible stars have lost most of their accreted angular momentum.

  2. Theory of the n = 2 levels in muonic deuterium

    NASA Astrophysics Data System (ADS)

    Krauth, Julian J.; Diepold, Marc; Franke, Beatrice; Antognini, Aldo; Kottmann, Franz; Pohl, Randolf

    2016-03-01

    The present knowledge of Lamb shift, fine- and hyperfine structure of the 2S and 2P states in muonic deuterium is reviewed in anticipation of the results of a first measurement of several 2S -2P transition frequencies in muonic deuterium (μd). A term-by-term comparison of all available sources reveals reliable values and uncertainties of the QED and nuclear structure-dependent contributions to the Lamb shift, which are essential for a determination of the deuteron rms charge radius from μd. Apparent discrepancies between different sources are resolved, in particular for the difficult two-photon exchange contributions. Problematic single-sourced terms are identified which require independent recalculation.

  3. Particle coating-dependent interaction of molecular weight fractionated natural organic matter: impacts on the aggregation of silver nanoparticles.

    PubMed

    Yin, Yongguang; Shen, Mohai; Tan, Zhiqiang; Yu, Sujuan; Liu, Jingfu; Jiang, Guibin

    2015-06-02

    Ubiquitous natural organic matter (NOM) plays an important role in the aggregation state of engineered silver nanoparticles (AgNPs) in aquatic environment, which determines the transport, transformation, and toxicity of AgNPs. As various capping agents are used as coatings for nanoparticles and NOM are natural polymer mixture with wide molecular weight (MW) distribution, probing the particle coating-dependent interaction of MW fractionated natural organic matter (Mf-NOM) with various coatings is helpful for understanding the differential aggregation and transport behavior of engineered AgNPs as well as other metal nanoparticles. In this study, we investigated the role of pristine and Mf-NOM on the aggregation of AgNPs with Bare, citrate, and PVP coating (Bare-, Cit-, and PVP-AgNP) in mono- and divalent electrolyte solutions. We observed that the enhanced aggregation or dispersion of AgNPs in NOM solution highly depends on the coating of AgNPs. Pristine NOM inhibited the aggregation of Bare-AgNPs but enhanced the aggregation of PVP-AgNPs. In addition, Mf-NOM fractions have distinguishing roles on the aggregation and dispersion of AgNPs, which also highly depend on the AgNPs coating as well as the MW of Mf-NOM. Higher MW Mf-NOM (>100 kDa and 30-100 kDa) enhanced the aggregation of PVP-AgNPs in mono- and divalent electrolyte solutions, whereas lower MW Mf-NOM (10-30 kDa, 3-10 kDa and <3 kDa) inhibited the aggregation of PVP-AgNPs. However, all the Mf-NOM fractions inhibited the aggregation of Bare-AgNPs. For PVP- and Bare-AgNPs, the stability of AgNPs in electrolyte solution was significantly correlated to the MW of Mf-NOM. But for Cit-AgNPs, pristine NOM and Mf-NOM has minor influence on the stability of AgNPs. These findings about significantly different roles of Mf-NOM on aggregation of engineered AgNPs with various coating are important for better understanding of the transport and subsequent transformation of AgNPs in aquatic environment.

  4. Mercury (Hg) in meteorites: Variations in abundance, thermal release profile, mass-dependent and mass-independent isotopic fractionation

    NASA Astrophysics Data System (ADS)

    Meier, Matthias M. M.; Cloquet, Christophe; Marty, Bernard

    2016-06-01

    We have measured the concentration, isotopic composition and thermal release profiles of Mercury (Hg) in a suite of meteorites, including both chondrites and achondrites. We find large variations in Hg concentration between different meteorites (ca. 10 ppb to 14,000 ppb), with the highest concentration orders of magnitude above the expected bulk solar system silicates value. From the presence of several different Hg carrier phases in thermal release profiles (150-650 °C), we argue that these variations are unlikely to be mainly due to terrestrial contamination. The Hg abundance of meteorites shows no correlation with petrographic type, or mass-dependent fractionation of Hg isotopes. Most carbonaceous chondrites show mass-independent enrichments in the odd-numbered isotopes 199Hg and 201Hg. We show that the enrichments are not nucleosynthetic, as we do not find corresponding nucleosynthetic deficits of 196Hg. Instead, they can partially be explained by Hg evaporation and redeposition during heating of asteroids from primordial radionuclides and late-stage impact heating. Non-carbonaceous chondrites, most achondrites and the Earth do not show these enrichments in vapor-phase Hg. All meteorites studied here have however isotopically light Hg (δ202Hg = ∼-7 to -1) relative to the Earth's average crustal values, which could suggest that the Earth has lost a significant fraction of its primordial Hg. However, the late accretion of carbonaceous chondritic material on the order of ∼2%, which has been suggested to account for the water, carbon, nitrogen and noble gas inventories of the Earth, can also contribute most or all of the Earth's current Hg budget. In this case, the isotopically heavy Hg of the Earth's crust would have to be the result of isotopic fractionation between surface and deep-Earth reservoirs.

  5. Mass-dependent and mass-independent fractionation of mercury isotopes in precipitation from Guiyang, SW China

    NASA Astrophysics Data System (ADS)

    Wang, Zhuhong; Chen, Jiubin; Feng, Xinbin; Hintelmann, Holger; Yuan, Shengliu; Cai, Hongming; Huang, Qiang; Wang, Shuxiao; Wang, Fengyang

    2015-11-01

    The isotopic composition of mercury (Hg) is increasingly used to constrain the sources and pathways of this metal in the atmosphere. Though China has the highest Hg production, consumption and emission in the world, Hg isotope ratios are rarely reported for Chinese wet deposition. In this study, we examined, for the first time outside North America, both mass-dependent fractionation (MDF, expressed as δ202Hg) and mass-independent fractionation of odd (odd-MIF, Δ199Hg) and even (even-MIF, Δ200Hg) Hg isotopes in 15 precipitation samples collected from September 2012 to August 2013 in Guiyang (SW China). All samples displayed significant negative δ202Hg (-0.44 ∼ -4.27‰), positive Δ199Hg (+0.19 to +1.16‰) and slightly positive Δ200Hg (-0.01‰ to +0.20‰). Potential sources of Hg in precipitation were identified by coupling both MDF and MIF of Hg isotopes with a back-trajectory model. The results showed that local emission from coal-fired power plants and cement plants and western long-range transportation are two main contributing sources, while the contribution of Hg from south wind events would be very limited on an annual basis. The relatively lower Δ200Hg values in Guiyang precipitation may indicate a dilution effect by local sources and/or insignificant even-MIF in the tropopause contribution of this subtropical region. Our study demonstrates the usefulness of isotope fractionation, especially MIF for tracing sources and pathways of Hg in the atmosphere.

  6. In vivo NMR imaging of deuterium

    NASA Astrophysics Data System (ADS)

    Müller, S.; Seelig, J.

    D 2O is used as a contrast agent for studying anatomical images and flow in vivo by deuterium NMR. A deuterium image of the head of a living rat after administration of D 2O (5% v/v) in the drinking water is shown. It was obtained in 14 min with a surface coil and has a spatial resolution of about one millimeter. The application of D 2O as a tracer is discussed and the inflow of heavy water into the brain of a rat is recorded in a time series of deuterium images. Spatially resolved inflow time constants have been determined.

  7. Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

    NASA Astrophysics Data System (ADS)

    Klir, D.; Shishlov, A. V.; Kubes, P.; Rezac, K.; Fursov, F. I.; Kokshenev, V. A.; Kovalchuk, B. M.; Kravarik, J.; Kurmaev, N. E.; Labetsky, A. Yu.; Ratakhin, N. A.

    2012-03-01

    Deuterium gas-puff experiments have been carried out on the GIT-12 generator at the Institute of High Current Electronics in Tomsk. The emphasis was put on the study of plasma dynamics and neutron production in double shell gas puffs. A linear mass density of deuterium (D2) varied between 50 and 85 μg/cm. Somewhat problematic was a spread of the D2 gas at a large diameter in the central anode-cathode region. The generator operated in two regimes, with and without a plasma opening switch (POS). When the POS was used, a current reached a peak of 2.7 MA with a 200 ns rise time. Without the POS, a current rise time approached 1500 ns. The influence of different current rise times on neutron production was researched. Obtained results were important for comparison of fast deuterium Z-pinches with plasma foci. Average DD neutron yields with and without the POS were about 1011. The neutron yield seems to be dependent on a peak voltage at the Z-pinch load. In all shots, the neutron emission started during stagnation. At the beginning of the neutron production, the neutron emission correlated with soft x-rays and a significant fraction of neutrons could be explained by the thermonuclear mechanism. Nevertheless, a peak of the neutron emission occurred 40 ns after a soft x-ray peak. At this very moment, hard x-rays above 1 MeV were detected and a rapid expansion with a velocity of 3×105 m/s was observed. In the case of the POS, 1 MeV widths of radial neutron spectra implied that there are deuterons with the energy above 200 keV moving in the radial direction. On the basis of D2 gas puff experiments in the 0.3-17 MA region, the neutron yield dependence on a current as Y∝I3.0±0.2 was proposed.

  8. Surface Structure and Electron Density Dependence of Scattered Ne^+ Ion Fractions From the Si(100)-(2x1) Surface

    NASA Astrophysics Data System (ADS)

    Wolfgang, John; Nordlander, Peter; Vaquilla, Isadora; Lui, K. M.; Rabalais, J. W.

    2000-03-01

    Experimental measurements of ion neutralization rates scattered from semiconductor surfaces have shown strong dependence on local surface structure and charge density. Recent scattering experiments utilizing 4 KeV Ne^+ scattered from a Si(100)-(2x1)surface exhibit strong azmuthal anisotropy, and can be shown to directly correlate to the reconstructed silicon surface geometry. Using a simple rate equation approach, a model based on the local charge density of the silicon surface has been used to determine the final neutral ion fraction from this scattering experiment. This rate equation approach has also been applied to scattering events between 4 KeV Ne^+ and a n- or p-type Si(100)-(2x1) surface. In the case of an n-doped Si surface, little or no change in the final ion neutralization is observed, while p-doping of the Si surface presents a significant decrease in the final neutral ion fractions compared to the undoped case. This effect will be discussed using a rate equation analysis, examining contributions from modification of the valence and conduction bands as a result of Si doping upon the overall charge transfer and ion neutralization.

  9. Experimental determination of the strain and strain rate dependence of the fraction of plastic work converted to heat

    SciTech Connect

    Hodowany, J.; Ravichandran, G.; Rosakis, A.J.

    1995-12-31

    When metals are deformed dynamically, there is insufficient time for heat generated by plastic deformation to be conducted to the surroundings. Thus, the conversion of plastic work into heat at high strain rates can result in significant temperature increases, which contribute to thermal softening, thereby altering a material`s constitutive response. The fraction of plastic work converted to heat represents the strength of the coupling term between temperature and mechanical fields in thermalmechanical problems involving plastic flow. The experimental determination of this constitutive function is important since it is an integral part of the formulation of coupled thermomechanical field equations. This fraction also plays an important role in failure mode characterization for metals deforming at high rates of strain, such as the formation of adiabatic shear bands. This investigation systematically examines the rate of conversion of plastic work to heat in metals under dynamic loading. Temperature was measured in-situ using an array of high speed In-Sb infrared detectors. The plastic work rate and the heat generation rate were determined directly from experimental data. The ratio of heat generation rate to plastic work rate, i.e., the relative rate at which plastic work is converted to heat, was calculated from this data. The functional dependence of this quantity upon strain and strain rate is reported for 1020 steel, 2024 aluminum, Ti-6Al-4V titanium alloy, and C300 maraging steel.

  10. Measurements of branching fractions and time-dependent CP-violating asymmetries in B --> eta'K decays.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges-Pous, E; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Zhang, L; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Pierini, M; Plaszczynski, S; Schune, M H; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Patel, P M; Robertson, S H; Cerizza, G; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-05-20

    We present measurements of the B --> eta(')K branching fractions; for B(+) --> eta(')K(+) we measure also the time-integrated charge asymmetry Alpha(ch), and for B(0) --> eta(')K(0)(S) the time-dependent CP-violation parameters S and C. The data sample corresponds to 232 x 10(6) BB pairs produced by e(+)e(-) annihilation at the Upsilon (4S). The results are Beta(B --> eta(')K(+)) = (68.9 +/- 2.0 +/- 3.2) x 10(-6), Beta(B(0) --> eta(')K(0)) = (67.4 +/- 3.2) x 10(-6), Alpha(ch) = 0.033 +/- 0.028 +/- 0.005, S = 0.30 +/- 0.140 +/- 0.02, and C = -0.21 +/- 0.10 +/- 0.02, where the first error quoted is statistical and the second is systematic.

  11. Size- and density-dependent elution of normal and pathological red blood cells by gravitational field-flow fractionation.

    PubMed

    Cardot, P J; Elgéa, C; Guernet, M; Godet, D; Andreux, J P

    1994-04-01

    Elution of normal and pathological human red blood cells (RBCs) was performed by gravitational field-flow fractionation (GFFF). The reproducibility of the retention factor was lower than 10% and elution at high and low flow-rates confirmed the existence of "lifting forces". No direct correlation between size and retention was observed for normal RBCs in the absence of density information. Elution of pathological human RBCs, known to be modified in shape, density and rigidity, was performed. The elution parameters confirmed that the retention mechanism of RBCs is at least density dependent but that other factors can be involved, such as shape or deformity. Moreover, peak profile description parameters (standard deviation and asymmetry) can be qualitatively related to some biophysical parameters. Numerous elution characteristics can be linked to cell properties described in the literature and although GFFF appeared to have limited capabilities in terms of size analysis it appeared to be a versatile tool for studying cell biophysical characteristics.

  12. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments

    SciTech Connect

    Bang, W.; Quevedo, H. J.; Bernstein, A. C.; Dyer, G.; Ihn, Y. S.; Cortez, J.; Aymond, F.; Gaul, E.; Donovan, M. E.; Barbui, M.; Bonasera, A.; Natowitz, J. B.; Albright, B. J.; Fernández, J. C.; Ditmire, T.

    2014-12-10

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure the average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.

  13. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments

    DOE PAGES

    Bang, W.; Quevedo, H. J.; Bernstein, A. C.; ...

    2014-12-10

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure themore » average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.« less

  14. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments

    NASA Astrophysics Data System (ADS)

    Bang, W.; Quevedo, H. J.; Bernstein, A. C.; Dyer, G.; Ihn, Y. S.; Cortez, J.; Aymond, F.; Gaul, E.; Donovan, M. E.; Barbui, M.; Bonasera, A.; Natowitz, J. B.; Albright, B. J.; Fernández, J. C.; Ditmire, T.

    2014-12-01

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure the average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.

  15. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments.

    PubMed

    Bang, W; Quevedo, H J; Bernstein, A C; Dyer, G; Ihn, Y S; Cortez, J; Aymond, F; Gaul, E; Donovan, M E; Barbui, M; Bonasera, A; Natowitz, J B; Albright, B J; Fernández, J C; Ditmire, T

    2014-12-01

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure the average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.

  16. Mass Dependency of Isotope Fractionation of Gases Under Thermal Gradient and Its Possible Implications for Planetary Atmosphere Escaping Process

    NASA Technical Reports Server (NTRS)

    Sun, Tao; Niles, Paul; Bao, Huiming; Socki, Richard

    2014-01-01

    Physical processes that unmix elements/isotopes of gas molecules involve phase changes, diffusion (chemical or thermal), effusion and gravitational settling. Some of those play significant roles for the evolution of chemical and isotopic compositions of gases in planetary bodies which lead to better understanding of surface paleoclimatic conditions, e.g. gas bubbles in Antarctic ice, and planetary evolution, e.g. the solar-wind erosion induced gas escaping from exosphere on terrestrial planets.. A mass dependent relationship is always expected for the kinetic isotope fractionations during these simple physical processes, according to the kinetic theory of gases by Chapman, Enskog and others [3-5]. For O-bearing (O16, -O17, -O18) molecules the alpha O-17/ alpha O-18 is expected at 0.5 to 0.515, and for S-bearing (S32,-S33. -S34, -S36) molecules, the alpha S-33/ alpha S-34 is expected at 0.5 to 0.508, where alpha is the isotope fractionation factor associated with unmixing processes. Thus, one isotope pair is generally proxied to yield all the information for the physical history of the gases. However, we recently] reported the violation of mass law for isotope fractionation among isotope pairs of multiple isotope system during gas diffusion or convection under thermal gradient (Thermal Gradient Induced Non-Mass Dependent effect, TGI-NMD). The mechanism(s) that is responsible to such striking observation remains unanswered. In our past studies, we investigated polyatomic molecules, O2 and SF6, and we suggested that nuclear spin effect could be responsible to the observed NMD effect in a way of changing diffusion coefficients of certain molecules, owing to the fact of negligible delta S-36 anomaly for SF6.. On the other hand, our results also showed that for both diffusion and convection under thermal gradient, this NMD effect is increased by lower gas pressure, bigger temperature gradient and lower average temperature, which indicate that the nuclear spin effect may

  17. In-ESI source hydrogen/deuterium exchange of carbohydrate ions.

    PubMed

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

    2014-03-04

    We present the investigation of hydrogen/deuterium (H/D) exchange of carbohydrates ions occurring in the electrospray ion source. The shape of the deuterium distribution was observed to be considerably dependent on the temperature of the ion transfer tube and the solvent used. If deuterated alcohol (EtOD or MeOD) or D2O/deuterated alcohol is used as an electrospray solvent, then for high temperatures (>350 °C), intensive back exchange is observed, resulting in ∼30% depth of the deuterium exchange. At low temperatures (<150 °C), the back exchange is weaker and the depth of the deuterium exchange is ∼70%. In the intermediate temperature region (∼250 °C), the deuterium distribution is unusually wide for methanol and bimodal for ethanol. The addition of 1% formic acid results in low (∼30%) depth of the deuterium exchange for any temperature in the operating region. The bimodal distribution for the ethanol can be possibly explained by the presence of differently folded gas-phase ions of carbohydrates.

  18. Energy Levels of Hydrogen and Deuterium

    National Institute of Standards and Technology Data Gateway

    SRD 142 Energy Levels of Hydrogen and Deuterium (Web, free access)   This database provides theoretical values of energy levels of hydrogen and deuterium for principle quantum numbers n = 1 to 200 and all allowed orbital angular momenta l and total angular momenta j. The values are based on current knowledge of the revelant theoretical contributions including relativistic, quantum electrodynamic, recoil, and nuclear size effects.

  19. Vanadium hydride deuterium-tritium generator

    DOEpatents

    Christensen, L.D.

    1980-03-13

    A pressure controlled vanadium hydride gas generator was designed to provide deuterium-tritium gas in a series of pressure increments. A high pressure chamber filled with vanadium-deuterium-tritium hydride is surrounded by a heater which controls the hydride temperature. The heater is actuated by a power controller which responds to the difference signal between the actual pressure signal and a programmed pressure signal.

  20. Vicinal deuterium perturbations on hydrogen NMR chemical shifts in cyclohexanes.

    PubMed

    O'Leary, Daniel J; Allis, Damian G; Hudson, Bruce S; James, Shelly; Morgera, Katherine B; Baldwin, John E

    2008-10-15

    The substitution of a deuterium for a hydrogen is known to perturb the NMR chemical shift of a neighboring hydrogen atom. The magnitude of such a perturbation may depend on the specifics of bonding and stereochemical relationships within a molecule. For deuterium-labeled cyclohexanes held in a chair conformation at -80 degrees C or lower, all four possible perturbations of H by D as H-C-C-H is changed to D-C-C-H have been determined experimentally, and the variations seen, ranging from 6.9 to 10.4 ppb, have been calculated from theory and computational methods. The predominant physical origins of the NMR chemical shift perturbations in deuterium-labeled cyclohexanes have been identified and quantified. The trends defined by the Delta delta perturbation values obtained through spectroscopic experiments and by theory agree satisfactorily. They do not match the variations typically observed in vicinal J(H-H) coupling constants as a function of dihedral angles.

  1. Time and concentration dependency in the potentially affected fraction of species: the case of hydrogen peroxide treatment of ballast water.

    PubMed

    Smit, Mathijs G D; Ebbens, Eltjo; Jak, Robbert G; Huijbregtst, Mark A J

    2008-03-01

    Transport of large volumes of ballast water contributes greatly to invasions of species. Hydrogen peroxide (H2O2) can be used as a disinfectant to prevent the spread of exotic species via ballast water. Instead of using environmental risk assessment techniques for protecting a certain fraction of the species from being affected, the present study aimed to apply these techniques to define treatment regimes of H2O2 and effectively eliminate as many species as possible. Based on time-dependent dose-response curves for five marine species (Corophium volutator, Artemia salina, Brachionus plicatilis, Dunaliella teriolecta, and Skeletonema costatum), time-dependent species-sensitivity distributions (SSDs) were derived for different effect sizes. The present study showed that H2O2 can be used effectively to treat ballast water but that relatively high concentrations and long treatment durations are required to eliminate the vast majority of species in ballast water. The described toxicant effectiveness approach using SSDs also has other potential fields of application, including short-term application of biocides.

  2. Power-law dependence of the melting temperature of ubiquitin on the volume fraction of macromolecular crowders.

    PubMed

    Waegele, Matthias M; Gai, Feng

    2011-03-07

    The dependence of the melting temperature increase (ΔT(m)) of the protein ubiquitin on the volume fraction (ϕ) of several commonly used macromolecular crowding agents (dextran 6, 40, and 70 and ficoll 70) was quantitatively examined and compared to a recently developed theoretical crowding model, i.e., ΔT(m) ∼ (R(g)∕R(c))(α)φ(α∕3). We found that in the current case this model correctly predicts the power-law dependence of ΔT(m) on φ but significantly overestimates the role of the size (i.e., R(c)) of the crowding agent. In addition, we found that for ubiquitin the exponent α is in the range of 4.1-6.5, suggesting that the relation of α=3∕(3ν-1) is a better choice for estimating α based on the Flory coefficient (ν) of the polypeptide chain. Taken together these findings highlight the importance of improving our knowledge and theoretical treatment of the microcompartmentalization of the commonly used model crowding agents. © 2011 American Institute of Physics.

  3. Pion Induced Pion Production on Deuterium.

    NASA Astrophysics Data System (ADS)

    Sossi, Vesna

    V. We also added the Fermi motion of the nucleon to the model to account for the deuterium environment. The 'free' parameters of the model are the largely unknown coupling constants listed above. We fixed C to be -2.08 by requiring the energy dependence of the model to be that of the measurement of (22) and compared the energy and angular distributions of the model to our data for several values of the f_Delta and g_{N^*Delta_tau } coupling constants ranging between 0 and 2 (where the units are 4/5 f_{NNpi }) and between 1.08 and 1.53 respectively. We found reasonable sensitivity of the model to the f _Delta variation, but only limited sensitivity to the value of the g_{N ^*Delta_tau} coupling constant. Overall we achieved a very good agreement between data and the theoretical predictions for f_ Delta values smaller than 0.5 and g _{N^*Delta_tau} values closer to its lower limit. Improved statistical accuracy of the data would however be needed to better constrain the values of the coupling constants. On the basis of our results we feel that this model is a useful tool for planning future experiments and that a more extensive (pi,2pi) experimental program, where differential cross sections are measured for differing isospin channels, would provide a further, more stringent test on the model allowing for a more precise determination of the coupling constants.

  4. Free and bioavailable fractions of sex steroids may influence bones in young men, depending on age and oestradiol level.

    PubMed

    Szyska-Skrobot, Dorota; Marchlewska, Katarzyna; Walczak-Jędrzejowska, Renata; Oszukowska, Elżbieta; Filipiak, Eliza; Kula, Piotr; Mężyk, Ryszard; Kowalska, Aldona; Jaszewski, Ryszard; Słowikowska-Hilczer, Jolanta; Kula, Krzysztof

    2014-01-01

    Longitudinal bone growth ceases by the end of puberty, and it is thought to be a result, in both sexes, of increased pubertal oestrogen serum concentrations. Since peak bone mass is achieved by the third decade of life or later, the aim of this study was to relate sex steroid hormones and sex hormone binding globulin (SHBG) levels to bone quality in men during their third and fourth decades of life. Eighty men, healthy volunteers aged between 18 and 39 years, were subjected to an interviewer-administered questionnaire, body mass index (BMI) measurement, blood sample and calcaneal quantitative ultrasound (QUS) (Hologic-SAHARA). Blood was assessed for testosterone (T), oestradiol (E2), dehydroepiandrosterone sulfate (DHEAS), SHBG, luteinising hormone (LH) and follicle stimulating hormone (FSH). Free and bioavailable T and E2 levels were calculated knowing SHBG and albumin levels. While T, E2, DHEAS, LH and FSH levels were not related, free and bioavailable fractions of T and E2 were positively associated with QUS readings. SHBG level was associated negatively. After dichotomisation for age, the associations remained significant only for younger subjects (18-30 years, n = 47). After adjustment for other co-variants, only SHBG in younger subjects retained its negative association with QUS. Older subjects (31-39 years, n = 33) revealed higher BMI and lower serum concentrations of total (-17 %), free (-18.5%) and bioavailable (-22.5%) levels of E2 than younger subjects. Free and bioavailable fractions of sex steroids may influence bones in young men, depending on age and E2 level.

  5. Measurements of branching fractions and time-dependent CP violating asymmetries in B0→D(*)±D∓ decays

    NASA Astrophysics Data System (ADS)

    Röhrken, M.; Adachi, I.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Bakich, A. M.; Barrett, M.; Belous, K.; Bhardwaj, V.; Bhuyan, B.; Bischofberger, M.; Bondar, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Brovchenko, O.; Browder, T. E.; Chang, M.-C.; Chen, A.; Chen, P.; Cheon, B. G.; Chilikin, K.; Cho, I.-S.; Cho, K.; Choi, Y.; Dalseno, J.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Eidelman, S.; Fast, J. E.; Feindt, M.; Gaur, V.; Gabyshev, N.; Garmash, A.; Goh, Y. M.; Haba, J.; Hayashii, H.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Hyun, H. J.; Iijima, T.; Ishikawa, A.; Itoh, R.; Iwabuchi, M.; Iwasaki, Y.; Julius, T.; Kang, J. H.; Kawasaki, T.; Kiesling, C.; Kim, H. J.; Kim, H. O.; Kim, J. B.; Kim, J. H.; Kim, K. T.; Kim, M. J.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Koblitz, S.; Kodyš, P.; Korpar, S.; Kouzes, R. T.; Križan, P.; Krokovny, P.; Kronenbitter, B.; Kuhr, T.; Kumita, T.; Kwon, Y.-J.; Lee, S.-H.; Li, J.; Li, Y.; Libby, J.; Liu, C.; Liu, Y.; Liu, Z. Q.; Liventsev, D.; Louvot, R.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Moll, A.; Mori, T.; Muramatsu, N.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Ogawa, S.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Ozaki, H.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Park, K. S.; Pedlar, T. K.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Poluektov, A.; Prim, M.; Prothmann, K.; Ritter, M.; Ryu, S.; Sahoo, H.; Sakai, Y.; Sanuki, T.; Sato, Y.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Senyo, K.; Seon, O.; Sevior, M. E.; Shapkin, M.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Sibidanov, A.; Simon, F.; Singh, J. B.; Smerkol, P.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Sumisawa, K.; Sumiyoshi, T.; Trabelsi, K.; Uchida, M.; Uehara, S.; Unno, Y.; Uno, S.; Urquijo, P.; Vanhoefer, P.; Varner, G.; Varvell, K. E.; Vorobyev, V.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamamoto, H.; Yamashita, Y.; Zander, D.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

    2012-05-01

    We report measurements of branching fractions and time-dependent CP asymmetries in B0→D+D- and B0→D*±D∓ decays using a data sample that contains (772±11)×106BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We determine the branching fractions to be B(B0→D+D-)=(2.12±0.16±0.18)×10-4 and B(B0→D*±D∓)=(6.14±0.29±0.50)×10-4. We measure CP asymmetry parameters SD+D-=-1.06-0.14+0.21±0.08 and CD+D-=-0.43±0.16±0.05 in B0→D+D- and AD*D=+0.06±0.05±0.02, SD*D=-0.78±0.15±0.05, CD*D=-0.01±0.11±0.04, ΔSD*D=-0.13±0.15±0.04 and ΔCD*D=+0.12±0.11±0.03 in B0→D*±D∓, where the first uncertainty is statistical and the second is systematic. We exclude the conservation of CP symmetry in both decays at equal to or greater than 4σ significance.

  6. The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23

    NASA Astrophysics Data System (ADS)

    Matthee, Jorryt; Sobral, David; Oteo, Iván; Best, Philip; Smail, Ian; Röttgering, Huub; Paulino-Afonso, Ana

    2016-05-01

    We present the first results from our CAlibrating LYMan α with Hα (CALYMHA) pilot survey at the Isaac Newton Telescope. We measure Lyα emission for 488 Hα selected galaxies at z = 2.23 from High-z Emission Line Survey in the COSMOS and UDS fields with a specially designed narrow-band filter (λc = 3918 Å, Δλ = 52 Å). We find 17 dual Hα-Lyα emitters [fLyα > 5 × 10-17 erg s-1 cm-2, of which five are X-ray active galactic nuclei (AGN)]. For star-forming galaxies, we find a range of Lyα escape fractions (fesc, measured with 3 arcsec apertures) from 2 to 30 per cent. These galaxies have masses from 3 × 108 M⊙ to 1011 M⊙ and dust attenuations E(B - V) = 0-0.5. Using stacking, we measure a median escape fraction of 1.6 ± 0.5 per cent (4.0 ± 1.0 per cent without correcting Hα for dust), but show that this depends on galaxy properties. The stacked fesc tends to decrease with increasing star formation rate and dust attenuation. However, at the highest masses and dust attenuations, we detect individual galaxies with fesc much higher than the typical values from stacking, indicating significant scatter in the values of fesc. Relations between fesc and UV slope are bimodal, with high fesc for either the bluest or reddest galaxies. We speculate that this bimodality and large scatter in the values of fesc is due to additional physical mechanisms such as outflows facilitating fesc for dusty/massive systems. Lyα is significantly more extended than Hα and the UV. fesc continues to increase up to at least 20 kpc (3σ, 40 kpc [2σ]) for typical star-forming galaxies and thus the aperture is the most important predictor of fesc.

  7. BRANCHING FRACTION AND TIME-DEPENDENT CP ASYMMETRY IN NEUTRAL B DECAYS TO PSI AND A NEUTRAL PION

    SciTech Connect

    Soha, Aron L

    2003-05-23

    The invariance of physical laws under the combination of exchange of particles with antiparticles (charge conjugation, C) and reversal of coordinates (parity, P) is called CP symmetry. The violation of CP symmetry was first discovered in 1964 in the neutral kaon system, and is in general one of the great puzzles of particle physics. The recent observation of CP violation in the B meson system has been a simultaneous success for model predictions and experiment. The opportunity now exists to probe details of the underlying mechanisms. This thesis presents measurements of the branching fraction and time-dependent CP-violating asymmetry in neutral B decays to J/{psi}{pi}{sup 0}. The decay amplitude for this channel features both tree and penguin diagram contributions, the interference of which can yield a result for the asymmetry differing from that found in the ''golden mode'' B{sup 0} {yields} J/{psi} K{sub s}{sup 0}. Using the measured branching fraction and CP asymmetry, constraints are placed on the ratio of penguin to tree amplitudes in B{sup 0} {yields} J/{psi}{pi}{sup 0}. In addition, the impact on the CP asymmetry measurement in B{sup 0} {yields} J/{psi} K{sub s}{sup 0} is discussed. The results are presented for e{sup +}e{sup -} annihilation data collected with the BABAR detector on the {Upsilon}(4S) resonance at the PEP-II asymmetric-energy B Factory at SLAC. The measurement of the branching fraction, based on about 23 million B{bar B} pairs collected between October 1999 and October 2000, yields BF(B{sup 0} {yields} J/{psi}{pi}{sup 0}) = (2.0 {+-} 0.6 (stat) {+-} 0.2(syst)) x 10{sup -5}. With about 88 million B{bar B} pairs collected during the years 1999-2002, our results for the coefficients of the cosine and sine terms of the CP asymmetry are C{sub J/{psi}{pi}{sup 0}} = 0.38 {+-} 0.41 (stat) {+-} 0.09 (syst) and S{sub J/{psi}{pi}{sup 0}} = 0.05 {+-} 0.49 (stat) {+-} 0.16 (syst).

  8. Measurement and modeling of diffusion time dependence of apparent diffusion coefficient and fractional anisotropy in prostate tissue ex vivo.

    PubMed

    Bourne, Roger; Liang, Sisi; Panagiotaki, Eleftheria; Bongers, Andre; Sved, Paul; Watson, Geoffrey

    2017-10-01

    The purpose of this study was to measure and model the diffusion time dependence of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) derived from conventional prostate diffusion-weighted imaging methods as used in recommended multiparametric MRI protocols. Diffusion tensor imaging (DTI) was performed at 9.4 T with three radical prostatectomy specimens, with diffusion times in the range 10-120 ms and b-values 0-3000 s/mm(2) . ADC and FA were calculated from DTI measurements at b-values of 800 and 1600 s/mm(2) . Independently, a two-component model (restricted isotropic plus Gaussian anisotropic) was used to synthesize DTI data, from which ADC and FA were predicted and compared with the measured values. Measured ADC and FA exhibited a diffusion time dependence, which was closely predicted by the two-component model. ADC decreased by about 0.10-0.15 μm(2) /ms as diffusion time increased from 10 to 120 ms. FA increased with diffusion time at b-values of 800 and 1600 s/mm(2) but was predicted to be independent of diffusion time at b = 3000 s/mm(2) . Both ADC and FA exhibited diffusion time dependence that could be modeled as two unmixed water pools - one having isotropic restricted dynamics, and the other unrestricted anisotropic dynamics. These results highlight the importance of considering and reporting diffusion times in conventional ADC and FA calculations and protocol recommendations, and inform the development of improved diffusion methods for prostate cancer imaging. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Gas swelling and deuterium distribution in beryllium implanted with deuterium ions

    SciTech Connect

    Chernikov, V.N.; Alimov, V.Kh.; Zakharov, A.P.

    1995-09-01

    An extensive TEM study of the microstructure of Be TIP-30 irradiated with 3 and 10 keV D ions up to fluences, {Phi}, in the range from 3 x 10{sup 20} to 8 x 10{sup 21} D/m{sup 2} at temperatures T{sub irr} = 300 K, 500 K and 700 K has been carried out. Depth distributions of deuterium in the form of separate D atoms and D{sub 2} molecules have been investigated by means of SIMS and RGA methods, correspondingly. D ion irradiation is accompanied by blistering and gives rise to different kind of destructions depending mainly on the irradiation temperature. Irradiation with D ions at 300 K leads to the formation of tiny highly pressurized D{sub 2} bubbles reminiscent of He bubbles in Be. Under 3 keV D ion irradiation D{sub 2} bubbles ({bar r}{sub b} {approx} 0.7 nm) appear at a fluence as low as 3x10{sup 20} D/m{sup 2}. Irradiation at 500 K results in the development, along with relatively small facetted bubbles, of larger oblate gas-filled cavities accumulating most of injected D atoms and providing for much higher gas swelling values as compared to irradiation at 300 K. The increase of D and/or T{sub irr}, to 700 K causes the further coarsening of large cavities which are transformed into sub-surface labyrinth structures. D and He ion implantation leads to the enhanced growth of porous microcrystalline layers of c.p.h.-BeO oxide with a microstructure which differs considerably from that of oxide layers on electropolished surfaces of Be. Based on the analysis of experimental data questions of deuterium reemission, thermal desorption and trapping in Be have been discussed in detail.

  10. Deuterium nuclear magnetic resonance unambiguously quantifies pore and collagen-bound water in cortical bone

    PubMed Central

    Ong, Henry H.; Wright, Alexander C.; Wehrli, Felix W.

    2012-01-01

    Bone water (BW) plays a pivotal role in nutrient transport and conferring bone with its viscoelastic mechanical properties. BW is partitioned between the pore spaces of the Haversian and lacuno-canalicular system, and water predominantly bound to the matrix proteins (essentially collagen). The general model of BW is that the former predominantly experiences fast isotropic molecular reorientation, whereas water in the bone matrix undergoes slower anisotropic rotational diffusion. Here, we provide direct evidence for the correctness of this model and show that unambiguous quantification in situ of these two functionally and dynamically different BW fractions is possible. The approach chosen relies on nuclear magnetic resonance (NMR) of deuterium (2H) that unambiguously separates and quantifies the two fractions on the basis of their distinguishing microdynamic properties. Twenty-four specimens of the human tibial cortex from six donors (3 male, 3 female, ages 27-83 years) were cored and 2H spectra recorded at 62 MHz (9.4 Tesla) on a Bruker Instruments DMX 400 spectrometer after exchange of native BW with 2H2O. Spectra consisted of a doublet signal resulting from quadrupole interaction of water bound to collagen. Doublet splittings were found to depend on the orientation of the osteonal axis with respect to the magnetic field direction (8.2 and 4.3 kHz for parallel and perpendicular orientation, respectively). In contrast, the isotropically reorienting pore-resident water yielded a single resonance line superimposed on the doublet. Nulling of the singlet resonance allowed separation of the two fractions. The results indicate that in human cortical bone 60-80% of detectable BW is collagen-bound. Porosity determined as the difference between total BW and collagen bound water fraction was found to strongly parallel μCT based measurements (R2 = 0.91). Our method provides means for direct validation of emerging relaxation-based measurements of cortical bone porosity by

  11. Chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, prevents fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment.

    PubMed

    Lee, Tammy C; Greene-Schloesser, Dana; Payne, Valerie; Diz, Debra I; Hsu, Fang-Chi; Kooshki, Mitra; Mustafa, Rashida; Riddle, David R; Zhao, Weiling; Chan, Michael D; Robbins, Mike E

    2012-07-01

    We hypothesized that chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, to young adult male rats would prevent/ameliorate fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment. Eighty 12-14-week-old young adult male Fischer 344 rats received either: (1) sham irradiation, (2) 40 Gy of fractionated whole-brain irradiation delivered as two 5 Gy fractions/week for 4 weeks, (3) sham irradiation plus continuous administration of 15 mg/L of ramipril in the drinking water starting 3 days before irradiation, or (4) fractionated whole-brain irradiation plus ramipril. Cognitive function was assessed using a perirhinal cortex-dependent version of the novel object recognition task 26 weeks after irradiation. Microglial activation was determined in the perirhinal cortex and the dentate gyrus of the hippocampus 28 weeks after irradiation using the ED1 antibody. Neurogenesis was assessed in the granular cell layer and subgranular zones of the dentate gyrus using a doublecortin antibody. Fractionated whole-brain irradiation led to: (1) a significant impairment in perirhinal cortex-dependent cognitive function, (2) a significant increase in activated microglia in the dentate gyrus but not in the perirhinal cortex, and (3) a significant decrease in neurogenesis. Continuous administration of ramipril before, during, and after irradiation prevented the fractionated whole-brain irradiation-induced changes in perirhinal cortex-dependent cognitive function, as well as in microglial activation in the dentate gyrus. Thus, as hypothesized, continuous administration of the angiotensin-converting enzyme inhibitor, ramipril, can prevent the fractionated whole-brain irradiation-induced impairment in perirhinal cortex-dependent cognitive function.

  12. Chronic Administration of the Angiotensin-Converting Enzyme Inhibitor, Ramipril, Prevents Fractionated Whole-Brain Irradiation-Induced Perirhinal Cortex-Dependent Cognitive Impairment

    PubMed Central

    Lee, Tammy C.; Greene-Schloesser, Dana; Payne, Valerie; Diz, Debra I.; Hsu, Fang-Chi; Kooshki, Mitra; Mustafa, Rashida; Riddle, David R.; Zhao, Weiling; Chan, Michael D.; Robbins, Mike E.

    2012-01-01

    We hypothesized that chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, to young adult male rats would prevent/ameliorate fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment. Eighty 12–14-week-old young adult male Fischer 344 rats received either: (1) sham irradiation, (2) 40 Gy of fractionated whole-brain irradiation delivered as two 5 Gy fractions/week for 4 weeks, (3) sham irradiation plus continuous administration of 15 mg/L of ramipril in the drinking water starting 3 days before irradiation, or (4) fractionated whole-brain irradiation plus ramipril. Cognitive function was assessed using a perirhinal cortex-dependent version of the novel object recognition task 26 weeks after irradiation. Microglial activation was determined in the perirhinal cortex and the dentate gyrus of the hippocampus 28 weeks after irradiation using the ED1 antibody. Neurogenesis was assessed in the granular cell layer and subgranular zones of the dentate gyrus using a doublecortin antibody. Fractionated whole-brain irradiation led to: (1) a significant impairment in perirhinal cortex-dependent cognitive function, (2) a significant increase in activated microglia in the dentate gyrus but not in the perirhinal cortex, and (3) a significant decrease in neurogenesis. Continuous administration of ramipril before, during, and after irradiation prevented the fractionated whole-brain irradiation-induced changes in perirhinal cortex-dependent cognitive function, as well as in microglial activation in the dentate gyrus. Thus, as hypothesized, continuous administration of the angiotensin-converting enzyme inhibitor, ramipril, can prevent the fractionated whole-brain irradiation-induced impairment in perirhinal cortex-dependent cognitive function. PMID:22687052

  13. Pulsed deuterium lithium nuclear reactor

    SciTech Connect

    Fischer, A.G.

    1980-01-08

    A nuclear reactor that burns hydrogen bomb material 6-lithium deuterotritide to helium in successive microexplosions which are ignited electrically and enclosed by this same molten material, and that permits the conversion of the reaction heat into useful electrical power. A specially-constructed high-current pulse machine is discharged via a thermally-preformed highly conducting path through a mass of the molten salt 6lid1-xtx (0deuterium bubbles. The heat shock is buffered by partial melting of the external solid crust. The reaction heat is carried by the liquid metal of the external cooling jacket to the heat exchanger of the associated turbo-generator. Every few seconds, a new pulse can take place.

  14. Sputtering and codeposition of silicon carbide with deuterium

    NASA Astrophysics Data System (ADS)

    Causey, Rion A.

    2003-03-01

    Due to its excellent thermal properties, silicon carbide is being considered as a possible plasma-facing material for fusion devices. If used as a plasma-facing material, the energetic hydrogen isotope ions and charge-exchanged neutrals escaping from the plasma will sputter the silicon carbide. To assess the tritium inventory problems that will be generated by the use of this material, it is necessary that we know the codeposition properties of the redeposited silicon carbide. To determine the codeposition properties, the deuterium plasma experiment at Sandia National Laboratories in Livermore, California has been used to directly compare the deuterium sputtering and codeposition of silicon carbide with that of graphite. A Penning discharge at a flux of 6×10 19 D/m 2 and an energy of ≈300 eV was used to sputter silicon and carbon from a pair of 0.05 m diameter silicon carbide disks. The removal rate of deuterium gas from the fixed volume of the system isolated from all other sources and sinks was used to measure the codeposition probability (probability that a hydrogen isotope atom will be removed through codeposition per ion striking the sample surface). A small catcher plate used to capture a fraction of the codeposited film was analyzed using Auger spectroscopy. This analysis showed the film to begin with a high carbon to silicon ratio due to preferential sputtering of the carbon. As the film became thicker, the ratio of the depositing material changed over to the (1:1) value that must eventually be attained.

  15. Measurements of Branching Fractions and Time-Dependent CP-Violating Asymmetries in B to eta' K Decays

    SciTech Connect

    Aubert, B.

    2005-02-07

    The authors present measurements of the B {yields} {eta}{prime}K branching fractions; for B{sup +} {yields} {eta}{prime}K{sup +} they measure also the time-integrated charge asymmetry {Alpha}{sub ch}, and for B{sup 0} {yields} {eta}{prime}K{sub s}{sup 0} the time dependent CP-violation parameters S and C. The data sample corresponds to 232 million B{bar B} pairs produced by e{sup +}e{sup -} annihilation at the {Upsilon}(4S). The results are {Beta}(B{sup +} {yields} {eta}{prime}K{sup +}) = (68.9 {+-} 2.0 {+-} 3.2) x 10{sup -6}, {Beta}(B{sup 0} {yields} {eta}{prime}K{sup 0}) = (67.4 {+-} 3.3 {+-} 3.2) x 10{sup -6}, {Alpha}{sub ch} = 0.033 {+-} 0.028 {+-} 0.005, S = 0.30 {+-} 0.14 {+-} 0.02, and C = -0.21 {+-} 0.10 {+-} 0.02, where the first error quoted is statistical and the second systematic.

  16. Controlling the Neutron Yield from a Small Dense Plasma Focus using Deuterium-Inert Gas Mixtures

    SciTech Connect

    Bures, B. L.; Krishnan, M.; Eshaq, Y.

    2009-01-21

    The dense plasma focus (DPF) is a well known source of neutrons when operating with deuterium. The DPF is demonstrated to scale from 10{sup 4} n/pulse at 40 kA to >10{sup 12} n/pulse at 2 MA by non-linear current scaling as described in [1], which is itself based on the simple yet elegant model developed by Lee [2]. In addition to the peak current, the gas pressure controls the neutron yield. Recent published results suggest that mixing 1-5% mass fractions of Krypton increase the neutron yield per pulse by more than 10x. In this paper we present results obtained by mixing deuterium with Helium, Neon and Argon in a 500 J dense plasma focus operating at 140 kA with a 600 ns rise time. The mass density was held constant in these experiments at the optimum (pure) deuterium mass density for producing neutrons. A typical neutron yield for a pure deuterium gas charge is 2x10{sup 6}{+-}15% n/pulse. Neutron yields in excess of 10{sup 7}{+-}10% n/pulse were observed with low mass fractions of inert gas. Time integrated optical images of the pinch, soft x-ray measurements and optical emission spectroscopy where used to examine the pinch in addition to the neutron yield monitor and the fast scintillation detector. Work supported by Domestic Nuclear Detection Office under contract HSHQDC-08-C-00020.

  17. Threshold character of temperatures on deuterium desorption from the Mg-Zr composite

    NASA Astrophysics Data System (ADS)

    Neklyudov, I. M.; Morozov, O. M.; Kulish, V. G.; Zhurba, V. I.; Lomino, N. S.; Ovcharenko, V. D.; Kuprin, O. S.

    2011-06-01

    The plasma evaporation-sputtering method was used to manufacture composite materials of the Mg-Zr system. The ion-implanted deuterium desorption temperature variations depending on the component concentrations were studied. It has been established that the introduction of a Zr impurity to magnesium leads to the significant decrease of the deuterium desorption temperature (~400K) as compared to the release from Mg samples. A step-like form of the curve of the deuterium desorption temperature testifies to presence of two various structural conditions at composite Mg-Zr depending on the relation of components. The hydrogen desorption data obtained using Mg-Zr composites can be used for the further invrstigations into the hydrogen storage materials containing chemical elements with a low solubility in the alloy components.

  18. Hot muonic deuterium and tritium from cold targets

    SciTech Connect

    Marshall, G.M.; Beveridge, J.L. ); Bailey, J.M. ); Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A. ); Brewer, J.H.; Forster, B.M. ); Huber, T.M.; Pippitt, B. ); Jacot-Guillarmod, R.; Schellenberg, L. (Fribourg U

    1992-01-01

    Experiments are described which use a solid hydrogen layer to form muonic hydrogen isotopes in vacuum. The method relies on transfer of the muon from protium to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections, and may be emitted from the surface of the layer. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes. A target has been constructed which exploits muonic atom emission in order to study the energy dependence of transfer and muon molecular formation.

  19. Hot muonic deuterium and tritium from cold targets

    SciTech Connect

    Marshall, G.M.; Beveridge, J.L.; Bailey, J.M.; Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A.; Brewer, J.H.; Forster, B.M.; Huber, T.M.; Pippitt, B.; Jacot-Guillarmod, R.; Schellenberg, L.; Kammel, P.; Zmeskal, J.; Kunselman, A.R.; Martoff, C.J.; Petitjean, C.

    1992-12-31

    Experiments are described which use a solid hydrogen layer to form muonic hydrogen isotopes in vacuum. The method relies on transfer of the muon from protium to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections, and may be emitted from the surface of the layer. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes. A target has been constructed which exploits muonic atom emission in order to study the energy dependence of transfer and muon molecular formation.

  20. Impact-induced devolatilization and hydrogen isotopic fractionation of serpentine: Implications for planetary accretion

    NASA Technical Reports Server (NTRS)

    Tyburczy, James A.; Krishnamurthy, R. V.; Epstein, Samuel; Ahrens, Thomas J.

    1988-01-01

    Impact-induced devolatilization of porous serpentine was investigated using two independent experimental methods, the gas recovery and the solid recovery method, each yielding nearly identical results. For shock pressures near incipient devolatilization, the hydrogen isotopic composition of the evolved H2O is very close to that of the starting material. For shock pressures at which up to 12 percent impact-induced devolatilization occurs, the bulk evolved gas is significantly lower in deuterium than the starting material. There is also significant reduction of H2O to H2 in gases recovered at these higher shock pressures, probably caused by reaction of evolved H2O with the metal gas recovery fixture. Gaseous H2O-H2 isotopic fractionation suggests high temperature isotopic equilibrium between the gaseous species, indicating initiation of devolatilization at sites of greater than average energy deposition. Bulk gas-residual solid isotopic fractionations indicate nonequilibrium, kinetic control of gas-solid isotopic ratios. Impact-induced hydrogen isotopic fractionation of hydrous silicates during accretion can strongly affect the long-term planetary isotopic ratios of planetary bodies, leaving the interiors enriched in deuterium. Depending on the model used for extrapolation of the isotopic fractionation to devolatilization fractions greater than those investigated experimentally can result from this process.

  1. Fundamental Equation of State for Deuterium

    SciTech Connect

    Richardson, I. A.; Leachman, J. W.; Lemmon, E. W.

    2014-03-15

    World utilization of deuterium is anticipated to increase with the rise of fusion-energy machines such as ITER and NIF. We present a new fundamental equation of state for the thermodynamic properties of fluid deuterium. Differences between thermodynamic properties of orthodeuterium, normal deuterium, and paradeuterium are described. Separate ideal-gas functions were fitted for these separable forms together with a single real-fluid residual function. The equation of state is valid from the melting line to a maximum pressure of 2000 MPa and an upper temperature limit of 600 K, corresponding to available experimental measurements. The uncertainty in predicted density is 0.5% over the valid temperature range and pressures up to 300 MPa. The uncertainties of vapor pressures and saturated liquid densities are 2% and 3%, respectively, while speed-of-sound values are accurate to within 1% in the liquid phase.

  2. Deuterium isotope effect on the oxidation of monophenols and o-diphenols by tyrosinase.

    PubMed Central

    Fenoll, Lorena G; Peñalver, María José; Rodríguez-López, José N; García-Ruiz, P A; García-Cánovas, Francisco; Tudela, José

    2004-01-01

    A solvent deuterium isotope effect on the catalytic affinity (km) and catalytic constant (kcat) of tyrosinase in its action on different monophenols and o-diphenols was observed. The catalytic constant decreased in all substrates as the molar fraction of deuterated water in the medium increased, while the catalytic affinity only decreased for the o-diphenols with an R group in C-1 [-H, -CH3 and -CH(CH3)2]. In a proton inventory study of the oxidation of o-diphenols, the representation of kcat fn/kcat f0 against n (atom fractions of deuterium), where kcat fn is the catalytic constant for a molar fraction of deuterium (n) and kcat f0 is the corresponding kinetic parameter in a water solution, was linear for all substrates, indicating that only one of the four protons transferred from the hydroxy groups of the two molecules of substrate, which are oxidized in one turnover, is responsible for the isotope effects, the proton transferred from the hydroxy group of C-4 to the peroxide of the oxytyrosinase form (Eox). However, in the representation of Km fn/Km f0 against n, where Km fn represents the catalytic affinity for a molar fraction of deuterium (n) and Km f0 is the corresponding kinetic parameter in a water solution, a linear decrease was observed as n increased in the case of o-diphenols with the R group [-H, -CH3 and -CH(CH3)2], and a parabolic increase with other R groups, indicating that more than one proton is responsible for the isotope effects on substrate binding. In the case of monophenols with six protons transferred in the catalytic cycle, the isotope effect occurs in the same way as for o-diphenols. In the present paper, the fractionation factors of different monophenols and o-diphenols are described and possible mechanistic implications are discussed. PMID:15025557

  3. Surface structure and electron density dependence of scattered Ne + ion fractions from the Si(1 0 0)-(2×1) surface

    NASA Astrophysics Data System (ADS)

    Vaquila, I.; Lui, K. M.; Rabalais, J. W.; Wolfgang, J.; Nordlander, P.

    2001-01-01

    The magnitudes and azimuthal anisotropies of 4 keV Ne + scattered ion fractions from the Si(1 0 0)-(2×1) two-domain surface have been measured by means of time-of-flight scattering and recoiling spectrometry. The absolute values of these ion fractions as well as their dependence on surface structure and electron density have been determined. By investigating the trajectories of the scattered Ne +, a clear correlation is demonstrated between these experimentally observed surviving ion fractions of Ne + and the fraction of ions that scatters from the topmost layer of the surface. This is interpreted in terms of a model in which the neutralization probability of Ne + is proportional to the local substrate electronic charge density.

  4. Deuterium kinetic isotope effect (DKIE) in copper-induced LDL peroxidation: Interrelated effects of on inhibition and propagation.

    PubMed

    Pinchuk, Ilya; Lichtenberg, Dov

    2017-06-01

    LDL peroxidation plays a major role in many physiological and pathophysiological processes. The mechanisms of LDL peroxidation induced by transition metal ions have therefore been studied intensively. It has been proposed that the mechanism involves free radical production that occurs via decomposition of hydroperoxides. This, in turn, requires the cleavage of O-H bonds. Cleavage of O-D bond is slower and comparison of the kinetics in D2O to the kinetics in H2O is therefore a straightforward way to test this aspect of the alleged mechanism. The kinetics of peroxidation exhibit marked deuterium kinetic isotope effects at all the stages of oxidation under all the studied conditions. We found that the rate of propagation of copper-induced peroxidation is a monotonically decreasing function of D2O fraction in D2O/H2O mixtures. The only elementary reaction that involves "exchangeable" hydrogen at this stage is copper-induced decomposition of conjugated hydroperoxides. Therefore, we conclude that the latter step is rate-limiting reaction including cleavage of oxygen-hydrogen bond of hydroperoxide. The lag preceding rapid peroxidation exhibits a biphasic dependence on the fraction of D2O. This may be understood on the basis of the effect of substituting hydrogen atoms by deuterium. Specifically, such substitution is expected to decrease both the rate of initiation of peroxidation and the potency of the antioxidant. We interpret our results in terms of the effects of isotopic substitution on the rates of the reactions that involve the abstraction of "exchangeable" hydrogen atoms of OH groups in tocopherol and hydroperoxides. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Community N and O isotope fractionation by sulfide-dependent denitrification and anammox in a stratified lacustrine water column

    NASA Astrophysics Data System (ADS)

    Wenk, Christine B.; Zopfi, Jakob; Blees, Jan; Veronesi, Mauro; Niemann, Helge; Lehmann, Moritz F.

    2014-01-01

    We investigated the community nitrogen (N) and oxygen (O) isotope effects of fixed N loss in the northern basin of Lake Lugano, where sulfide-dependent denitrification and anammox are the main drivers of suboxic N2 production. A decrease in nitrate (NO3-) concentration toward the redox transition zone (RTZ) at mid-water depth was paralleled by an increase in δ15N and δ18O from approximately 5‰ to >20‰ and from 0‰ to >10‰, respectively. Ammonium (NH4+) concentrations were highest in the near-bottom water and decreased toward the RTZ concomitant with an increase in δ15N-NH4+ from ∼7‰ to >15‰. A diffusion-reaction model yielded N and O isotope enrichment factors that are significantly smaller than isotope effects reported previously for microbial NO3- reduction and NH4+ oxidation (15εNO3 ≈ 10‰, 18εNO3 ≈ 7‰, and 15εNH4 ≈ 10-12‰). For the Lake Lugano north basin, we constrain the apparent under-expression of the N isotope effects to: (1) environmental conditions (e.g., substrate limitation, low cell specific N transformation rates), or (2) low process-specific (chemolithotrophic denitrification and anammox) isotope fractionation. Our results have confirmed the robust nature of the co-linearity between N and O isotope enrichment during microbial denitrification beyond its organotrophic mode. However, the ratio of 18O to 15N enrichment (18εNO3:15εNO3) associated with NO3- reduction in the RTZ was ∼0.89, which is lower than observed in marine environments and in most culture experiments. We propose that chemolithotrophic NO3- reduction in the Lake Lugano north basin was partly catalyzed by the periplasmic dissimilatory nitrate reductase (Nap) (rather than the membrane-bound dissimilatory Nar), which is known to express comparably low 18εNO3:15εNO3 ratios in the ambient NO3- pool. However, NO2- re-oxidation, e.g., during anammox or microaerobic nitrification, could have contributed to the lowered 18O to 15N enrichment ratios. Although

  6. Thermal boundary layer convection in silicic magma chambers: Effects of temperature-dependent rheology and implications for thermogravitational chemical fractionation

    NASA Astrophysics Data System (ADS)

    Spera, Frank J.; Yuen, David A.; Kirschvink, Stephen J.

    1982-10-01

    vertical velocities wmax of 10 and 25 km/yr, boundary layer thicknesses δT of 20 and 50 m, and marginal heat flows q0 of 1200 and 700 HFU, respectively. Transport parameters depend markedly on H2O content; for anhydrous rhyolite with identical boundary conditions q0 ˜ 600 HFU, umax ˜0.5 km yr-1 and τ0 ˜ 10-1 bar at a distance of 1 km along the vertical wall. Maximum vertical convective velocities usually exceed crystal settling rates by several orders of magnitude; crystal settling cannot be important in vigorously convecting chambers except in local regions. The petrological and geothermal implications of the calculations are discussed in terms of an extreme (but plausible) type of magmatic system, the constant enthalpy open magma chamber. In this case, heat losses due to dissipation of magmatic heat to the country rock are precisely balanced by heat input by injection of hot, mafic magma into the roots of the chamber. The requirements of the thermal steady-state chamber permit an estimation of the mass flow rate into the roots of the chamber. Results agree well with known rates of basaltic magmatism along mid-ocean ridges and at intraplate `hot spot' sites. Semi-quantitative evaluation of the magnitude of chemical fractionation in a constant enthalpy magma chamber due to coupling of rapid (km yr-1) vertical convective flow with slow horizontal Soret diffusion across thin marginal thermal layers suggests that on a 106 year time scale, significant chemical gradients can be generated. An analytical approach is suggested for answering the question of whether or not such fractionated melt can maintain its integrity (i.e., not become remixed).

  7. Deuterium-free water ( 1H2O) in complex life-support systems of long-term space missions

    NASA Astrophysics Data System (ADS)

    Sinyak, Y.; Grigoriev, A.; Gaydadimov, V.; Gurieva, T.; Levinskih, M.; Pokrovskii, B.

    Heavy water containing deuterium displays toxic property. It is stated that any quantity of a heavy isotope of hydrogen—deuterium—is undesirable to animals and plants. It was earlier shown by us that physical-chemical life support systems on board the "MIR" station fractionate (change) isotopes of hydrogen, oxygen and carbon. Therefore, the problem of regenerative systems in habitable space objects should include removal, from water, of a heavy stable isotope of hydrogen—deuterium. In this article we consider one method of obtaining deuterium-free water—decomposition of distillate water in an electrolyser to hydrogen and oxygen with subsequent synthesis in a catalytic or high-temperature reactor. The influence of deuterium-free water on the growth and development of Arabidopsis thaliana and Japanese quail is investigated. It is shown that with the help of the electrolysis method it is possible to fabricate water containing 80% less deuterium in comparison with SMOW. Experimentally, it is proved on a culture of Arabidopsis thaliana and Japanese quail that water with reduced contents of deuterium (80%) displays positive biological activity.

  8. Radiofrequency ablation of coronary sinus-dependent atrial flutter guided by fractionated mid-diastolic coronary sinus potentials

    PubMed Central

    De Sisti, Antonio; Amara, Walid; Frank, Robert; Hidden-Lucet, Françoise

    2010-01-01

    Background The efficacy of radiofrequency (RF) ablation of an uncommon coronary sinus (CS)-dependent atrial flutter (AFL) was evaluated using conventional electrophysiological criteria in a highly selected subset of patients with typical and atypical AFL. Methods Fourteen patients with atrial flutter (11 males, mean age 69 ± 9 years) without previous right or left atrial RF ablation were included. Heart disease was present in eight patients. Baseline ECG suggested typical AFL in 12 patients and atypical AFL in two. Mean AFL cycle length was 324 ± 64 ms at the time of RF ablation in the CS. Lateral right atrium activation was counterclockwise (CCW) in 13 patients and clockwise in one. CS activation was CCW in all. Criteria for CS ablation included the presence of CS mid-diastolic fractionated atrial potentials (APs) associated with concealed entrainment with a postpacing interval within 20 ms. Success was defined as termination of AFL and subsequent noninducibility. Results The initial target for ablation was the cavotricuspid isthmus (CTI) in 11 patients and the CS with further CTI ablation in three. AP duration at the CS target site was 122 ± 33 ms, spanning 40 ± 12% of the AFL cycle length. CS ablation site was located 1–4 cm from the CS ostium. Ablation was successful in all patients. Mean time to AFL termination during CS ablation was 39 ± 52 s (<20 s in eight patients). No recurrence of ablated arrhythmia occurred during a follow-up of 18 ± 8 months. Conclusions The CS musculature is a critical part of some AFL circuits in patients with typical and atypical AFL. AFL can be terminated in patients with CS or CTI/CS AFL reentrant circuits by targeting CS mid-diastolic fragmented APs. PMID:20814733

  9. Depletion of GSH in human blood plasma and cytosolic fraction during cadmium toxicity is temperature and pH dependent.

    PubMed

    Ullah, Hashmat; Khan, Muhammad Farid; Jan, Syed Umer; Hashmat, Farwa

    2016-01-01

    Toxicities of heavy metals is a burning issue and a topic of interest among the toxicologists throughout the world. Metals are always in use of man since long but in recent years the use of cadmium has increased in the form of various cadmium compounds such as cadmium compounds as stabilizers in plastic pipe industries and in the preparations of different alloys etc. Cadmium is even used in phosphate fertilizers and thus comes directly or indirectly in contact with human eatables like crops, vegetables and fruits. Once it is absorbed it affects almost all the organs and systems of human body especially blood components and kidneys. Always the chemical reactions of different chemicals are dependent on some influential factors, among these factors the effect of pH and temperature of the media in which these chemicals interact with each other are very much important. Keeping in view this fact we have evaluated the effect of cadmium nitrate tetra hydrate on GSH of human plasma and cytosolic fraction. Estimation of thiol was done by Ellman's modified method and was found that the interaction of cadmium nitrate tetra hydrate and GSH of these blood components was more at a pH and temperature, which were near to physiological pH and temperature of human body. This fact was proved as the estimated thiol concentration left after the interaction of cadmium nitrate tetra hydrate and thiol of these blood components was minimum at pH and temperature near to human blood pH and temperature. We concluded that the possible reason for depletion of GSH of these blood components was conversion of GSH into Cd(SG) (2) and/or GSSG formation.

  10. Deuterium separation by infrared-induced addition reaction

    DOEpatents

    Marling, John B.

    1977-01-01

    A method for deuterium enrichment by the infrared-induced addition reaction of a deuterium halide with an unsaturated aliphatic compound. A gaseous mixture of a hydrogen halide feedstock and an unsaturated aliphatic compound, particularly an olefin, is irradiated to selectively vibrationally excite the deuterium halide contained therein. The excited deuterium halide preferentially reacts with the unsaturated aliphatic compound to produce a deuterated addition product which is removed from the reaction mixture.

  11. The need for T₂ correction on MRS-based vertebral bone marrow fat quantification: implications for bone marrow fat fraction age dependence.

    PubMed

    Dieckmeyer, Michael; Ruschke, Stefan; Cordes, Christian; Yap, Samuel P; Kooijman, Hendrik; Hauner, Hans; Rummeny, Ernst J; Bauer, Jan S; Baum, Thomas; Karampinos, Dimitrios C

    2015-04-01

    Vertebral bone marrow fat quantification using single-voxel MRS is confounded by overlapping water-fat peaks and the difference in T2 relaxation time between water and fat components. The purposes of the present study were: (i) to determine the proton density fat fraction (PDFF) of vertebral bone marrow using single-voxel multi-TE MRS, addressing these confounding effects; and (ii) to investigate the implications of these corrections with respect to the age dependence of the PDFF. Single-voxel MRS was performed in the L5 vertebral body of 86 subjects (54 women and 32 men). To reliably extract the water peak from the overlying fat peaks, the mean bone marrow fat spectrum was characterized based on the area of measurable fat peaks and an a priori knowledge of the chemical triglyceride structure. MRS measurements were performed at multiple TEs. The T2 -weighted fat fraction was calculated at each TE. In addition, a T2 correction was performed to obtain the PDFF and the T2 value of water (T2w ) was calculated. The implications of the T2 correction were investigated by studying the age dependence of the T2 -weighted fat fractions and the PDFF. Compared with the PDFF, all T2 -weighted fat fractions significantly overestimated the fat fraction. Compared with the age dependence of the PDFF, the age dependence of the T2 -weighted fat fraction showed an increased slope and intercept as TE increased for women and a strongly increased intercept as TE increased for men. For women, a negative association between the T2 value of bone marrow water and PDFF was found. Single-voxel MRS-based vertebral bone marrow fat quantification should be based on a multi-TE MRS measurement to minimize confounding effects on PDFF determination, and also to allow the simultaneous calculation of T2w , which might be considered as an additional parameter sensitive to the composition of the water compartment.

  12. Integrated Simulation Studies of Plasma Performances and Fusion Reactions in the Deuterium Experiment of LHD

    NASA Astrophysics Data System (ADS)

    Murakami, S.; Yamaguchi, H.; Homma, M.; Maeta, S.; Saito, Y.; Fukuyama, A.; Nagaoka, K.; Takahashi, H.; Nakano, H.; Osakabe, M.; Yokoyama, M.; Tanaka, K.; Ida, K.; Yoshinuma, M.; Isobe, M.; Tomita, H.; Ogawa, K.; LHD Exp Group Team

    2016-10-01

    The deuterium experiment project from 2017 is planned in LHD, where the deuterium NBI heating beams with the power more than 30MW are injected into the deuterium plasma. Principal objects of this project are to clarify the isotope effect on the heat and particle transport in the helical plasma and to study energetic particle confinement in a helical magnetic configuration measuring triton burn-up neutrons. We study the deuterium experiment plasma of LHD applying the integrated simulation code, TASK3D [Murakami, PPCF2015], and the 5-D drift kinetic equation solver, GNET [Murakami, NF2006]. (i) More than 20% of ion temperature increment is obtained in the deuterium plasma (nD /nH +nD = 0.8) due to the isotope effect assuming the turbulent transport model based on the H/He plasma experiment of LHD. (ii) The triton burn-up simulation shows the triton slowing down distribution and the strong magnetic configuration dependency of the triton burn-up ratio in LHD. This work was supported by JSPS KAKENHI Grant Number 26420851.

  13. Helium processing for deuterium/helium burns in ITER's physics phase

    SciTech Connect

    Finn, P.A.; Sze, D.K.

    1991-01-01

    The requirements for vacuum pumping and fuel processing for deuterium/helium (D/{sup 3}He) burns in the physics operating phase for the International Thermonuclear Experimental Reactor (ITER) were assessed. These burns are expected to have low fusion power (100 MW), short burn times ({le}30 s), limited operation (2000 shots), and a fractional burn {approximately}0.3%. For the physics phase, the fuel processing system will include several units to separate deuterium and helium (activated charcoal bed, SAES getter and a Pd/Ag diffuser), as well as an isotopic separation system to separate {sup 3}He and {sup 4}He. The needed vacuum system's cryosorption surface area may be as large as 10 m{sup 2} if the burn time is {approximately}200 s, the fractional burn is <0.3%, or the fusion power is >100 MW. 8 refs., 1 fig., 4 tabs.

  14. Theoretical predictions of deuterium abundances in the Jovian planets

    SciTech Connect

    Hubbard, W.B.; MacFarlane, J.J.

    1980-01-01

    Current concepts for the origin of the Jovian planets and current constraints on their interior structure are used to support the argument that the presence of large amounts of 'ice' (H2O, CH4, and NH3) in Uranus and Neptune indicates temperature low enough to condense these species at the time Uranus and Neptune formed. Such low temperatures, however, imply orders-of-magnitude fractionation effects for deuterium into the 'ice' component if isotopic equilibration can occur. The present models thus imply that Uranus and Neptune should have D/H ratio at least four times primordial, contrary to observation for Uranus. It is found that the Jovian and Saturnian D/H should be close to primordial regardless of formation scenario.

  15. Dependence of the hormonal stimulation of adenylate cyclase on the fraction of the plasma membrane accessible for lateral displacement of proteins of the adenylate cyclase complex

    SciTech Connect

    Kazarov, A.R.; Rozenkrants, A.A.; Sobolev, A.S.

    1986-09-10

    Hormonal activation of the adenylate cyclase complex is associated with lateral displacement in the membrane of the proteins that constitute this complex. In this work an experimental investigation was made of the changes in the interaction of the proteins of the adenylate cyclase complex with the changing fraction of fluid lipids in the cell membrane. A decrease in the fraction of fluid lipids of rat reticulocyte membranes led to a decrease (all the way down to a total suppression) of the interaction of the ..beta..-adrenoreceptors with the regulatory N-proteins. The interaction of the N-proteins with the catalytic proteins was also suppressed. On the other hand, an increase in the fraction of fluid lipids led to more effective interaction. It was shown that in this case the functional intactness of the interacting proteins is unimpaired. An analysis of the results obtained, performed on the basis of the percolation theory, suggests the conclusion that the hormonal stimulation of adenylate cyclase depends on the fraction of fluid lipids in the membrane, and the proteins are displaced during interaction over distances comparable with the size of the membrane itself. It was also shown that characteristic activity of the ..beta..-agonist 1-isoproterenol varies from 1.0 to 0, depending on the fraction of fluid lipids in the membrane. The data obtained suggest that in the absence of guanylic nucleotides in the membrane in vitro there are no preexisting complexes with a high affinity for the agonist.

  16. The predicted abundances of deuterium-bearing gases in the atmospheres of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.; Prinn, Ronald G.

    1988-01-01

    The first set of comprehensive thermochemical equilibrium and chemical kinetic calculations on the chemistry of deuterium-bearing gases in the deep atmospheres of Jupiter and Saturn is presented. The sensitivity of the results to variations in elemental and isotopic abundances is studied. Isotopic fractionation effects in the C-13/C12, N-15/N-14, and O-18/O-16 ratios in nonequilibrium species such as CO, CO2, HCN, and N2 are briefly considered.

  17. The deuterium puzzle in the symmetric universe

    NASA Technical Reports Server (NTRS)

    Leroy, B.; Nicolle, J. P.; Schatzman, E.

    1973-01-01

    An attempt was made to use deuterium abundance in the symmetric universe to prove that no nucleosynthesis takes place during annihilation and therefore neutrons were loss before nucleosynthesis. Data cover nucleosynthesis during the radiative era, cross section estimates, maximum abundance of He-4 at the end of nucleosynthesis area, and loss rate.

  18. Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling: A case study from Mangrove Lake, Bermuda

    NASA Astrophysics Data System (ADS)

    Pellerin, André; Bui, Thi Hao; Rough, Mikaella; Mucci, Alfonso; Canfield, Donald E.; Wing, Boswell A.

    2015-01-01

    The multiple sulfur isotope composition of porewater sulfate from the anoxic marine sapropel of Mangrove Lake, Bermuda was measured in order to establish how multiple sulfur isotopes are fractionated during reoxidative sulfur cycling. The porewater-sulfate δ34S and Δ33S dataset exhibits the distinct isotopic signatures of microbial sulfate reduction and sulfur reoxidation. We reproduced the measurements with a simple diagenetic model that yielded fractionation factors for net sulfate removal of between -29.2‰ and -32.5‰. A new approach to isotopic modeling of the sulfate profiles, informed by the chemistry of sulfur intermediate compounds in Mangrove Lake, reveals that sulfate reduction produces a relatively small intrinsic fractionation and that an active reoxidative sulfur cycle increases the fractionation of the measured values. Based on the model results, the reoxidative cycle of Mangrove Lake appears to include sulfide oxidation to elemental sulfur followed by the disproportionation of the elemental sulfur to sulfate and sulfide. This model also indicates that the reoxidative sulfur cycle of Mangrove Lake turns over from 50 to 80% of the sulfide produced by microbial sulfate reduction. The Mangrove Lake case study shows how sulfur isotope fractionations can be separated into three different "domains" in Δ33S-δ34S space based on their ability to resolve reductive and reoxidative sulfur transformations. The first domain that differentiates reductive and reoxidative sulfur cycling is well illustrated by previous studies and requires 34S-32S fractionations more negative than ≈-70‰, beyond the fractionation limit of microbial sulfate reduction at earth surface temperatures. The second domain that distinguishes reductive and reoxidative processes is between 34S-32S fractionations of -40‰ and 0‰, where the 33S-32S fractionations of sulfate reduction and reoxidation are significantly different. In the remaining domain (between 34S-32S fractionations

  19. Forward Hadron Production in Muon Deep Inelastic Scattering at 490-GeV from Deuterium and Xenon

    SciTech Connect

    Salvarani, Alexandro F.

    1991-01-01

    This thesis presents measurements of the energy fraction $z$ and transverse momentum of the final state charged hadrons in muon deep inelastic scattering at 490 Ge V from deuterium and xenon targets. The measurements were made as part of Experiment 665 at Fermilab. The ratio of the forward hadron multiplicity between the two nuclei shows that at large transfer energy, $\

  20. Magnetohydrodynamic Simulation of Solid-Deuterium - Z-Pinch Experiments

    NASA Astrophysics Data System (ADS)

    Sheehey, Peter Trogdon

    Solid-deuterium-initiated Z-pinch experiments are numerically simulated using a two-dimensional resistive magnetohydrodynamic model, which includes many important experimental details, such as "cold-start" initial conditions, thermal conduction, radiative energy loss, actual discharge current vs. time, and grids of sufficient size and resolution to allow realistic development of the plasma. The alternating -direction-implicit numerical technique used meets the substantial demands presented by such a computational task. Simulations of fiber-initiated experiments show that when the fiber becomes fully ionized (at a time depending on current ramp and fiber thickness), rapidly developing m = 0 instabilities, which originated in the coronal plasma generated from the ablating fiber, drive intense non-uniform heating and rapid expansion of the plasma column. The possibility that inclusion of additional physical effects would improve stability is explored. Finite-Larmor-radius-ordered Hall and diamagnetic pressure terms in the magnetic field evolution equation, corresponding energy equation terms, and separate ion and electron energy equations are included; these do not change the basic results. Model diagnostics, such as shadowgrams and interferograms, generated from simulation results, are in good agreement with experiment. Two alternative experimental approaches are explored: high-current magnetic implosion of hollow cylindrical deuterium shells, and "plasma -on wire" (POW) implosion of low-density plasma onto a central deuterium fiber. By minimizing instability problems, these techniques may allow attainment of higher temperatures and densities than possible with bare fiber-initiated Z -pinches. Conditions for significant D-D or D-T fusion neutron production may be realizable with these implosion -based approaches.

  1. Radio observations of D I and fractionation

    NASA Technical Reports Server (NTRS)

    Heiles, Carl; Mccullough, Peter R.; Glassgold, Alfred E.

    1993-01-01

    We report observations to detect the 327 MHz line of atomic deuterium in the primarily molecular clouds towards Cas A and Sgr A, making appropriate choices of spectral and spatial resolution. Our best results for Cas A, based on 1253 hr of observing with the 85 foot (26 m) Hat Creek telescope and 45 hr with the very large array (VLA), yield an upper limit for the fraction of deuterium in atomic form, D I, of 0.14. We present an approximate analytical analysis of deuterium fractionation in translucent clouds, which shows that gas-phase ion-molecule reactions, assisted by dust and HD line self-shielding, are efficient in converting deuterium to HD. We conclude that little atomic deuterium is present in the molecular clumps in the Cas A clouds and that much higher sensitivity observations would be required to detect 327 MHz line in molecular clouds. We have also attempted to detect the 72 GHz line of DCO(+) toward Cas A. The observed upper limit to the DCO(+)/HCO(+) ratio of approximately 0.03 is not much larger than our theoretical estimate, and the DCO(+) line should be detectable with existing instrumentation, unless the temperature of these clouds is much larger than usually assumed.

  2. Radio observations of D I and fractionation

    NASA Technical Reports Server (NTRS)

    Heiles, Carl; Mccullough, Peter R.; Glassgold, Alfred E.

    1993-01-01

    We report observations to detect the 327 MHz line of atomic deuterium in the primarily molecular clouds towards Cas A and Sgr A, making appropriate choices of spectral and spatial resolution. Our best results for Cas A, based on 1253 hr of observing with the 85 foot (26 m) Hat Creek telescope and 45 hr with the very large array (VLA), yield an upper limit for the fraction of deuterium in atomic form, D I, of 0.14. We present an approximate analytical analysis of deuterium fractionation in translucent clouds, which shows that gas-phase ion-molecule reactions, assisted by dust and HD line self-shielding, are efficient in converting deuterium to HD. We conclude that little atomic deuterium is present in the molecular clumps in the Cas A clouds and that much higher sensitivity observations would be required to detect 327 MHz line in molecular clouds. We have also attempted to detect the 72 GHz line of DCO(+) toward Cas A. The observed upper limit to the DCO(+)/HCO(+) ratio of approximately 0.03 is not much larger than our theoretical estimate, and the DCO(+) line should be detectable with existing instrumentation, unless the temperature of these clouds is much larger than usually assumed.

  3. Hydrogen-deuterium substitution in solid ethanol by surface reactions at low temperatures

    NASA Astrophysics Data System (ADS)

    Oba, Yasuhiro; Osaka, Kazuya; Chigai, Takeshi; Kouchi, Akira; Watanabe, Naoki

    2016-10-01

    Ethanol (CH3CH2OH) is one of the most abundant complex organic molecules in star-forming regions. Despite its detection in the gas phase only, ethanol is believed to be formed by low-temperature grain-surface reactions. Methanol, the simplest alcohol, has been a target for observational, experimental, and theoretical studies in view of its deuterium enrichment in the interstellar medium; however, the deuterium chemistry of ethanol has not yet been an area of focus. Recently, deuterated dimethyl ether, a structural isomer of ethanol, was found in star-forming regions, indicating that deuterated ethanol can also be present in those environments. In this study, we performed laboratory experiments on the deuterium fractionation of solid ethanol at low temperatures through a reaction with deuterium (D) atoms at 10 K. Hydrogen (H)-D substitution, which increases the deuteration level, was found to occur on the ethyl group but not on the hydroxyl group. In addition, when deuterated ethanol (e.g. CD3CD2OD) solid was exposed to H atoms at 10 K, D-H substitution that reduced the deuteration level occurred on the ethyl group. Based on the results, it is likely that deuterated ethanol is present even under H-atom-dominant conditions in the interstellar medium.

  4. The fractional acoustoelectric current plateau induced by the energy-dependent tunnelling from dynamic quantum dots into an impurity dot

    NASA Astrophysics Data System (ADS)

    Chen, S. W.; Song, L.

    2016-08-01

    The fractional acoustoelectric (AE) current plateau in surface-acoustic-waves (SAW) single-electron transport devices is studied by measuring the current plateau as a function of the SAW power and gate bias as well as a function of perpendicular magnetic filed. Our investigation indicates that the fractional plateau is induced by the tunnelling effect from the dynamic quantum dots (QDs) into a static impurity dot. Rate equations are used to extract the tunnelling rates, which change a lot with the number of electrons in the dynamic QDs, the SAW power and gate bias. In addition, the current plateau evolves into a fractional structure, when a strong perpendicular magnetic field is applied to the system.

  5. Mass dependent fractionation of stable chromium isotopes in mare basalts: Implications for the formation and the differentiation of the Moon

    NASA Astrophysics Data System (ADS)

    Bonnand, Pierre; Parkinson, Ian J.; Anand, Mahesh

    2016-02-01

    We present the first stable chromium isotopic data from mare basalts in order to investigate the similarity between the Moon and the Earth's mantle. A double spike technique coupled with MC-ICP-MS measurements was used to analyse 19 mare basalts, comprising high-Ti, low-Ti and KREEP-rich varieties. Chromium isotope ratios (δ53Cr) for mare basalts are positively correlated with indices of magmatic differentiation such as Mg# and Cr concentration which suggests that Cr isotopes were fractionated during magmatic differentiation. Modelling of the results provides evidence that spinel and pyroxene are the main phases controlling the Cr isotopic composition during fractional crystallisation. The most evolved samples have the lightest isotopic compositions, complemented by cumulates that are isotopically heavy. Two hypotheses are proposed to explain this fractionation: (i) equilibrium fractionation where heavy isotopes are preferentially incorporated into the spinel lattice and (ii) a difference in isotopic composition between Cr2+ and Cr3+ in the melt. However, both processes require magmatic temperatures below 1200 °C for appreciable Cr3+ to be present at the low oxygen fugacities found in the Moon (IW -1 to -2 log units). There is no isotopic difference between the most primitive high-Ti, low-Ti and KREEP basalts, which suggest that the sources of these basalts were homogeneous in terms of stable Cr isotopes. The least differentiated sample in our sample set is the low-Ti basalt 12016, characterised by a Cr isotopic composition of -0.222 ± 0.025‰, which is within error of the current BSE value (-0.124 ± 0.101‰). The similarity between the mantles of the Moon and Earth is consistent with a terrestrial origin for a major fraction of the lunar Cr. This similarity also suggests that Cr isotopes were not fractionated by core formation on the Moon.

  6. Trajectory dependence of scattered Ne+ and recoiled S- ion fractions from the Cd- and S-terminated CdS{0001} surfaces

    NASA Astrophysics Data System (ADS)

    Houssiau, L.; Rabalais, J. W.; Wolfgang, J.; Nordlander, P.

    1999-04-01

    Scattered Ne+ and recoiled S- ion fractions resulting from 4 keV Ne+ and 4 keV Kr+ impingement, respectively, on both the Cd- and S-terminated surfaces of CdS{0001} have been measured. The absolute values of these ion fractions as well as their dependence on surface structure and electron density have been determined. Using a density functional approach, a clear correlation has been demonstrated between these Ne+ and S- ion fractions and the lateral variation of the electrostatic potential along the outgoing trajectories of the scattered and recoiled atoms. The observed anisotropy in the ion fractions is a result of the variations in surface to atom electron transfer rates due to tunneling barriers introduced by the electrostatic potentials. Both the Ne+ and S- ion fractions are higher on the Cd-terminated surface than on the S-terminated surface and their azimuthal patterns are different due to the spatial modulation of the electron tunneling rates on the surface caused by the electrostatic barriers. The azimuthal anisotropies of electrons ejected during the collision indicate that they are emitted only from collisions whose impact parameters are less than a threshold value, consistent with a kinetic electron emission mechanism.

  7. Cosmic Deuterium and Social Networking Software

    NASA Astrophysics Data System (ADS)

    Pasachoff, J. M.; Suer, T.-A.; Lubowich, D. A.; Glaisyer, T.

    2006-08-01

    For the education of newcomers to a scientific field and for the convenience of students and workers in the field, it is helpful to have all the basic scientific papers gathered. For the study of deuterium in the Universe, in 2004-5 we set up http://www.cosmicdeuterium.info with clickable links to all the historic and basic papers in the field and to many of the current papers. Cosmic deuterium is especially important because all deuterium in the Universe was formed in the epoch of nucleosynthesis in the first 1000 seconds after the Big Bang, so study of its relative abundance (D:H~1:100,000) gives us information about those first minutes of the Universe's life. Thus the understanding of cosmic deuterium is one of the pillars of modern cosmology, joining the cosmic expansion, the 3 degree cosmic background radiation, and the ripples in that background radiation. Studies of deuterium are also important for understanding Galactic chemical evolution, astrochemistry, interstellar processes, and planetary formation. Some papers had to be scanned while others are available at the Astrophysical Data System, adswww.harvard.edu, or to publishers' Websites. By 2006, social networking software (http:tinyurl.com/ zx5hk) had advanced with popular sites like facebook.com and MySpace.com; the Astrophysical Data System had even set up MyADS. Social tagging software sites like http://del.icio.us have made it easy to share sets of links to papers already available online. We have set up http://del.icio.us/deuterium to provide links to many of the papers on cosmicdeuterium.info, furthering previous del.icio.us work on /eclipses and /plutocharon. It is easy for the site owner to add links to a del.icio.us site; it takes merely clicking on a button on the browser screen once the site is opened and the desired link is viewed in a browser. Categorizing different topics by keywords allows subsets to be easily displayed. The opportunity to expose knowledge and build an ecosystem of web

  8. A laser-driven source of polarized hydrogen and deuterium

    SciTech Connect

    Young, L.; Holt, R.J.; Gilman, R.A.; Kowalczyk, R.; Coulter, K.

    1989-01-01

    A novel laser-driven polarized source of hydrogen and deuterium which operates on the principle of spin-exchange optical pumping is being developed. This source is designed to operate as an internal target in an electron storage ring for fundamental studies of spin-dependent structure of nuclei. It has the potential to exceed the flux from existing conventional sources (3 /times/ 10/sup 16//s) by an order of magnitude. Currently, the source delivers hydrogen at a flux of 8 /times/ 10/sup 16/ atoms/s with an atomic polarization of 24% and deuterium at 6 /times/ 10/sup 16/ atoms/s with a polarization of 29%. Technical obstacles which have been overcome, with varying degrees of success are complete Doppler-coverage in the optical-pumping stage without the use of a buffer gas, wall-induced depolarization and radiation-trapping. Future improvements should allow achievement of the design goals of 4 /times/ 10/sup 17/ atoms/s with a polarization of 50%. 8 refs., 2 figs.

  9. Deuterium stable isotope ratios as tracers of water resource use: an experimental test with rock doves.

    PubMed

    McKechnie, Andrew E; Wolf, Blair O; Martínez del Rio, Carlos

    2004-07-01

    Naturally-occurring deuterium stable isotope ratios can potentially be used to trace water resource use by animals, but estimating the contribution of isotopically distinct water sources requires the accurate prediction of isotopic discrimination factors between water inputs and an animal's body water pool. We examined the feasibility of using estimates of water fluxes between a bird and its environment with a mass-balance model for the deuterium stable isotope ratio of avian body water (deltaDbody) to predict isotopic discrimination factors. Apparent fractionation and thus discrimination factors were predicted to vary with the proportion of an animal's total water losses than could be attributed to evaporative processes. To test our ability to predict isotopic discrimination, we manipulated water intake and evaporative water loss in rock doves (Columba livia) by providing them with fresh water or 0.15 M NaCl solution in thermoneutral or hot environments. After we switched the birds from drinking water with deltaD=-95 per thousand VSMOW (Vienna Standard Mean Ocean Water) to enriched drinking water with deltaD=+52 per thousand VSMOW, steady-state deltaDbody was approached asymptotically. The equilibrium deltaDbody was enriched by 10-50 per thousand relative to water inputs. After isotopic equilibrium was reached, the degree of enrichment was positively related (r2=0.34) to the fraction of total water loss that occurred by evaporation (revap/rH2O)supporting the major prediction of the model. The variation we observed in discrimination factors suggests that the apparent fractionation of deuterium will be difficult to predict accurately under natural conditions. Our results show that accurate estimates of the contribution of different water sources to a bird's body water pool require large deuterium isotopic differences between the sources.

  10. Deuterium motion in yttrium studied by ultrasonic measurements

    SciTech Connect

    Leisure, R.G. ); Schwarz, R.B.; Migliori, A. ); Torgeson, D.R. ); Svare, I. ); Anderson, I.S. )

    1993-07-01

    Ultrasonic-attenuation measurements in YD[sub 0.10] reveal broad, asymmetric attenuation peaks that are interpreted in terms of rapid motion of deuterium among interstitial sites in the Y metal lattice. The results are well described with a model involving tunneling among highly asymmetric sites. A weakly temperature-dependent relaxation rate, compatible with coupling of the sites to electrons, accounts for the relaxation up to about 70 K. At higher temperatures a strongly temperature-dependent relaxation rate becomes dominant. The major asymmetries that are responsible for the coupling of the tunneling centers to the ultrasound are attributed to the interaction between D atoms that lie on [ital different] [ital c] axes.

  11. Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D(*+)D(*-).

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kral, J F; Kukartsev, G; LeClerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Romosan, A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Knowles, D J; Morgan, S E; Penny, R C; Watson, A T; Watson, N K; Deppermann, T; Goetzen, K; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmuecker, H; Steinke, M; Barlow, N R; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Mackay, C; Wilson, F F; Abe, K; Cuhadar-Donszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Chao, M; Kirkby, D; Lankford, A J; Mandelkern, M; McMahon, S; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Schwanke, U; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Kuznetsova, N; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Barillari, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Dubitzky, R S; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, K R; Schwierz, R; Spaan, B; Wilden, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Khan, A; Lavin, D; Muheim, F; Playfer, S; Swain, J E; Tinslay, J; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Falciai, D; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Pastore, F C; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Gaillard, J R; Morton, G W; Nash, J A; Sanders, P; Taylor, G P; Grenier, G J; Lee, S-J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Brigljević, V; Cheng, C H; Lange, D J; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Kay, M; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Shorthouse, H W; Strother, P; Vidal, P B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, R J; Hart, P A; Forti, A C; Jackson, F; Lafferty, G D; Lyon, A J; Weatherall, J H; Williams, J C; Farbin, A; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Milek, M; Patel, P M; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Hast, C; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; LoSecco, J M; Gabriel, T A; Brau, B; Pulliam, T; Wong, Q K; Brau, J; Frey, R; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; Stark, J; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Tanaka, H A; Varnes, E W; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yeche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Coupal, D P; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Grauges-Pous, E; Hadig, T; Halyo, V; Hryn'ova, T; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocian, M L; Langenegger, U; Leith, D W G S; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Menke, S; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Robertson, S H; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Hu, H; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2003-09-26

    We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B0-->D(*+)D(*-) using a data sample of 88x10(6)BB pairs collected by the BABAR detector at the PEP-II B Factory at SLAC. We determine the CP-odd fraction to be 0.063+/-0.055(stat)+/-0.009(syst). The time-dependent CP asymmetry parameters Im(lambda(+)) and /lambda(+)/ are determined to be 0.05+/-0.29(stat)+/-0.10(syst) and 0.75+/-0.19(stat)+/-0.02(syst), respectively. The standard model predicts these parameters to be -sin(2beta and 1, respectively, in the absence of penguin diagram contributions.

  12. Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D*+D*-.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Altenburg, D; Feltresi, E; Hauke, A; Spaan, B; Brandt, T; Brose, J; Dickopp, M; Klose, V; Lacker, H M; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Wu, J; Dubitzky, R S; Langenegger, U; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Vazquez, W P; Charles, M J; Mader, W F; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Petersen, T C; Pierini, M; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Schofield, K C; Touramanis, C; Cormack, C M; Di Lodovico, F; Sacco, R; Brown, C L; Cowan, G; Flaecher, H U; Green, M G; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Li, X; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Strube, J; Torrence, E; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pacetti, S; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Graziani, G; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S; Thompson, J M; Va'vra, J; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, S L; Yu, Z; Neal, H

    2005-10-07

    We present an updated measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D*+D*- using 232x10(6)BB pairs collected by the BABAR detector at the SLAC PEP-II B factory. We determine the CP-odd fraction to be 0.125+/-0.044(stat)+/-0.007(syst). The time-dependent CP asymmetry parameters C+ and S+ are determined to be 0.06+/-0.17(stat)+/-0.03(syst) and -0.75+/-0.25(stat)+/-0.03(syst), respectively. The standard model predicts these parameters to be 0 and -sin2beta, respectively, in the absence of penguin amplitude contributions.

  13. Measurement of Time-Dependent CP Asymmetries and the CP-Odd Fraction in the Decay B0→D*+D*-

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Zghiche, A.; Palano, A.; Pompili, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Day, C. T.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; Leclerc, C.; Levi, M. E.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Ford, K.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; Morgan, S. E.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Steinke, M.; Barlow, N. R.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Kelly, M. P.; Latham, T. E.; Mackay, C.; Wilson, F. F.; Abe, K.; Cuhadar-Donszelmann, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Kyberd, P.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Golubev, V. B.; Ivanchenko, V. N.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Yushkov, A. N.; Best, D.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Mommsen, R. K.; Roethel, W.; Stoker, D. P.; Buchanan, C.; del Re, D.; Hadavand, H. K.; Hill, E. J.; Macfarlane, D. B.; Paar, H. P.; Rahatlou, Sh.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Dahmes, B.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beck, T. W.; Beringer, J.; Eisner, A. M.; Heusch, C. A.; Lockman, W. S.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Albert, J.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Narsky, I.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Abe, T.; Barillari, T.; Blanc, F.; Bloom, P.; Chen, S.; Clark, P. J.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Zhang, L.; Harton, J. L.; Hu, T.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Altenburg, D.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Lacker, H. M.; Maly, E.; Müller-Pfefferkorn, R.; Nogowski, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Tinslay, J.; Andreotti, M.; Azzolini, V.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Negrini, M.; Piemontese, L.; Sarti, A.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Bailey, S.; Morii, M.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Gaillard, J. R.; Morton, G. W.; Nash, J. A.; Sanders, P.; Taylor, G. P.; Grenier, G. J.; Lee, S.-J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Yi, J.; Davier, M.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Petersen, T. C.; Plaszczynski, S.; Schune, M. H.; Tantot, L.; Wormser, G.; Brigljević, V.; Cheng, C. H.; Lange, D. J.; Wright, D. M.; Bevan, A. J.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Kay, M.; Parry, R. J.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Back, J. J.; Harrison, P. F.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Brown, C. L.; Cowan, G.; Flack, R. L.; Flaecher, H. U.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Hart, P. A.; Forti, A. C.; Jackson, F.; Lafferty, G. D.; Lyon, A. J.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Kovalskyi, D.; Lae, C. K.; Lillard, V.; Roberts, D. A.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Saremi, S.; Staengle, H.; Willocq, S.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Mangeol, D. J.; Milek, M.; Patel, P. M.; Lazzaro, A.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Godang, R.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Hast, C.; Taras, P.; Nicholson, H.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Losecco, J. M.; Gabriel, T. A.; Brau, B.; Pulliam, T.; Wong, Q. K.; Brau, J.; Frey, R.; Potter, C. T.; Sinev, N. B.; Strom, D.; Torrence, E.; Colecchia, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Tiozzo, G.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; John, M. J.; Leruste, Ph.; Ocariz, J.; Pivk, M.; Roos, L.; Stark, J.; T'jampens, S.; Therin, G.; Manfredi, P. F.; Re, V.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Calderini, G.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Wagoner, D. E.; Danielson, N.; Elmer, P.; Lu, C.; Miftakov, V.; Olsen, J.; Smith, A. J.; Tanaka, H. A.; Varnes, E. W.; Bellini, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Mazzoni, M. A.; Morganti, S.; Pierini, M.; Piredda, G.; Safai Tehrani, F.; Voena, C.; Christ, S.; Wagner, G.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Xella, S. M.; Aleksan, R.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Schott, G.; Vasseur, G.; Yeche, Ch.; Zito, M.; Purohit, M. V.; Weidemann, A. W.; Yumiceva, F. X.; Aston, D.; Bartoldus, R.; Berger, N.; Boyarski, A. M.; Buchmueller, O. L.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dujmic, D.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Grauges-Pous, E.; Hadig, T.; Halyo, V.; Hryn'ova, T.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Ratcliff, B. N.; Robertson, S. H.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Simi, G.; Snyder, A.; Soha, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Va'Vra, J.; Wagner, S. R.; Weaver, M.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Edwards, A. J.; Meyer, T. I.; Roat, C.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Saleem, M.; Wappler, F. R.; Bugg, W.; Krishnamurthy, M.; Spanier, S. M.; Eckmann, R.; Kim, H.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Borean, C.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Vitale, L.; Vuagnin, G.; Panvini, R. S.; Banerjee, Sw.; Brown, C. M.; Fortin, D.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Kutter, P. E.; Li, H.; Liu, R.; di Lodovico, F.; Mihalyi, A.; Mohapatra, A. K.; Pan, Y.; Prepost, R.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, J.; Wu, S. L.; Yu, Z.; Neal, H.

    2003-09-01

    We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B0→D*+D*- using a data sample of 88×106BB¯ pairs collected by the BABAR detector at the PEP-II B Factory at SLAC. We determine the CP-odd fraction to be 0.063±0.055(stat)±0.009(syst). The time-dependent CP asymmetry parameters Im(λ+) and |λ+| are determined to be 0.05±0.29(stat)±0.10(syst) and 0.75±0.19(stat)±0.02(syst), respectively. The standard model predicts these parameters to be -sin(2β and 1, respectively, in the absence of penguin diagram contributions.

  14. Measurement of Time-Dependent CP Asymmetries and the CP-Odd Fraction in the Decay B0->D*+D*-

    SciTech Connect

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Vanderbilt U. /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.

    2005-07-06

    We present an updated measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B{sup 0} D*{sup +}D*{sup -} using 232 x 10{sup 6} B{bar B} pairs collected by the BABAR detector at the PEP-II B factory. We determine the CP-odd fraction to be 0.125 {+-} 0.044(stat) {+-} 0.007(syst). The time-dependent CP asymmetry parameters C{sub +} and S{sub +} are determined to be 0.06 {+-} 0.17(stat) {+-} 0.03(syst) and -0.75 {+-} 0.25(stat) {+-} 0.03(syst), respectively. The Standard Model predicts these parameters to be 0 and -sin2{beta}, respectively, in the absence of penguin amplitude contributions.

  15. High-dose total-body irradiation and autologous marrow reconstitution in dogs: dose-rate-related acute toxicity and fractionation-dependent long-term survival

    SciTech Connect

    Deeg, H.J.; Storb, R.; Weiden, P.L.; Schumacher, D.; Shulman, H.; Graham, T.; Thomas, E.D.

    1981-11-01

    Beagle dogs treated by total-body irradiation (TBI) were given autologous marrow grafts in order to avoid death from marrow toxicity. Acute and delayed non-marrow toxicities of high single-dose (27 dogs) and fractionated TBI (20 dogs) delivered at 0.05 or 0.1 Gy/min were compared. Fractionated TBI was given in increments of 2 Gy every 6 hr for three increments per day. Acute toxicity and early mortality (<1 month) at identical total irradiation doses were comparable for dogs given fractionated or single-dose TBI. With single-dose TBI, 14, 16, and 18 Gy, respectively, given at 0.05 Gy/min, 0/5, 5/5, and 2/2 dogs died from acute toxicity; with 10, 12, and 14 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 5/5 dogs died acutely. With fractionated TBI, 14 and 16 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 2/2 dogs died auctely. Early deaths were due to radiation enteritis with or without associated septicemia (29 dogs; less than or equal to Day 10). Three dogs given 10 Gy of TBI at 0.1 Gy/min died from bacterial pneumonia; one (Day 18) had been given fractionated and two (Days 14, 22) single-dose TBI. Fifteen dogs survived beyond 1 month; eight of these had single-dose TBI (10-14 Gy) and all died within 7 months of irradiation from a syndrome consisting of hepatic damage, pancreatic fibrosis, malnutrition, wasting, and anemia. Seven of the 15 had fractionated TBI, and only one (14 Gy) died on Day 33 from hepatic failure, whereas 6 (10-14 Gy) are alive and well 250 to 500 days after irradiation. In conclusion, fractionated TBI did not offer advantages over single-dose TBI with regard to acute toxicity and early mortality; rather, these were dependent upon the total dose of TBI. The total acutely tolerated dose was dependent upon the exposure rate; however, only dogs given fractionated TBI became healthy long-term survivors.

  16. The Production of Hadrons in Muon Scattering on Deuterium and Xenon Nuclei at 480-GeV

    SciTech Connect

    Soldner-Rembold, Stefan

    1992-01-01

    For the present thesis the hadronic final states of 6309 muon-deuterium events and 2064 muon-xenon events in the kinematical range Q2>1 (GeV/c)2, x>0.002, 0.1< y<0.85, 8< W<30 GeV, and θ>3.5 mrad were studied. The multiplicity distributions of the muon-deuterium events and the muon-xenon events were described by means of the negative binomial distribution in intervals of the c.m. energy W. The two parameters anti n (mean multiplicity) and 1/k show for the muon-deuterium events a linear dependence on ln W2. The mean multiplicity anti n on xenon (anti n=10.43±0.19) is distinctly higher than on deuterium (anti n=7.76±0.07). The rapidity distributions of the positively charged and the negatively charged hadrons from muon-deuterium events are very well described by the Monte-Carlo program LUND. In the two-particle rapidity correlation both short-range and long-range correlations can be detected. The two-particle rapidity correlation in the xenon data are different from the deuterium data in the backward range. This difference indicates that the intranuclear cascade takes place in a limited range of small rapidities - relatively independently on the residual fragmentation process.

  17. GROWTH OF AZOTOBACTER IN DEUTERIUM OXIDE

    PubMed Central

    Johnstone, D. B.

    1962-01-01

    Johnstone, D. B. (University of Vermont, Burlington). Growth of Azotobacter in deuterium oxide. J. Bacteriol. 83:867–870. 1962.—To the small list of bacteria that are reported to have been cultured in fully deuterated media can be added Azotobacter agilis and A. vinelandii. Moreover, these bacteria, although growing in a deuterium oxide medium with deuterated carbon sources, will fix atmospheric nitrogen. Lag periods occur prior to growth, and wide morphological variation is apparent during adaptation to a deuterated environment. A convenient method is presented for measuring, by infrared spectroscopy, the amount of water that accumulates in a D2O medium; during incubation this amounts to about 1% per day. Prevention of this accumulation of water indicates that growth, after a lag period, probably is not supported by accumulated hydrogen. PMID:14452164

  18. Deuterium content of the Venus atmosphere

    NASA Technical Reports Server (NTRS)

    Bertaux, Jean-Loup; Clarke, John T.

    1989-01-01

    The abundance of deuterium in the atmosphere of Venus is an important clue to the role of water in the planet's history, because ordinary and deuterated water escape the atmosphere at different rates. The high-resolution mode of the IUE was used to measure hydrogen Lyman-alpha emission from Venus, but only an upper limit on deuterium Lyman-alpha emission was found, from which was inferred a D/H ratio of less than 0.002-0.005. This is smaller by a factor of 3-8 than the D/H ratio derived from measurements by the Pioneer Venus Large Probe, and may indicate either a stratification of D/H ratio with altitude or a smaller overall ratio than previously thought.

  19. Deuterium Abundance in the Local Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Ferlet, R.; Gry, C.; Vidal-Madjar, A.

    1984-01-01

    The present situation of deuterium abundance evaluation in interstellar space is discussed, and it is shown that it should be or = .00001 by studying in more detail lambda the Sco line of sight and by observing two NaI interstellar components toward that star, it can be shown that the D/H evaluation made toward lambda Sco is in fact related to the local interstellar medium (less than 10 pc from the Sun). Because this evaluation is also or = .00001 it is in striking contrast with the one made toward alpha Aur (D/H or = .000018 confirming the fact that the deuterium abundance in the local interstellar medium varies by at least a factor of two over few parsecs.

  20. Scaling and long-range dependence in option pricing III: A fractional version of the Merton model with transaction costs

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Tian; Yan, Hai-Gang; Tang, Ming-Ming; Zhu, En-Hui

    2010-02-01

    A model for option pricing of fractional version of the Merton model with ‘Hurst exponent’ H being in [1/2,1) is established with transaction costs. In particular, for H∈(1/2,1) the minimal price Cmin(t,St) of an option under transaction costs is obtained, which displays that the timestep δt and the ‘Hurst exponent’ H play an important role in option pricing with transaction costs.

  1. Precision Measures of the Primordial Abundance of Deuterium

    NASA Astrophysics Data System (ADS)

    Cooke, Ryan J.; Pettini, Max; Jorgenson, Regina A.; Murphy, Michael T.; Steidel, Charles C.

    2014-01-01

    We report the discovery of deuterium absorption in the very metal-poor ([Fe/H] = -2.88) damped Lyα system at z abs = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D I absorption lines and the damping wings of the H I Lyα transition, we have obtained a new, precise measure of the primordial abundance of deuterium. Furthermore, to bolster the present statistics of precision D/H measures, we have reanalyzed all of the known deuterium absorption-line systems that satisfy a set of strict criteria. We have adopted a blind analysis strategy (to remove human bias) and developed a software package that is specifically designed for precision D/H abundance measurements. For this reanalyzed sample of systems, we obtain a weighted mean of (D/H)p = (2.53 ± 0.04) × 10-5, corresponding to a universal baryon density 100 Ωb, 0 h 2 = 2.202 ± 0.046 for the standard model of big bang nucleosynthesis (BBN). By combining our measure of (D/H)p with observations of the cosmic microwave background (CMB), we derive the effective number of light fermion species, N eff = 3.28 ± 0.28. We therefore rule out the existence of an additional (sterile) neutrino (i.e., N eff = 4.046) at 99.3% confidence (2.7σ), provided that the values of N eff and of the baryon-to-photon ratio (η10) did not change between BBN and recombination. We also place a strong bound on the neutrino degeneracy parameter, independent of the 4He primordial mass fraction, Y P: ξD = +0.05 ± 0.13 based only on the CMB+(D/H)p observations. Combining this value of ξD with the current best literature measure of Y P, we find a 2σ upper bound on the neutrino degeneracy parameter, |ξ| <= +0.062. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (VLT program IDs: 68.B-0115(A), 70.A-0425(C), 078.A-0185(A), 085.A-0109(A)), and at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of

  2. Precision measures of the primordial abundance of deuterium

    SciTech Connect

    Cooke, Ryan J.; Jorgenson, Regina A.; Murphy, Michael T.; Steidel, Charles C.

    2014-01-20

    We report the discovery of deuterium absorption in the very metal-poor ([Fe/H] = –2.88) damped Lyα system at z {sub abs} = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D I absorption lines and the damping wings of the H I Lyα transition, we have obtained a new, precise measure of the primordial abundance of deuterium. Furthermore, to bolster the present statistics of precision D/H measures, we have reanalyzed all of the known deuterium absorption-line systems that satisfy a set of strict criteria. We have adopted a blind analysis strategy (to remove human bias) and developed a software package that is specifically designed for precision D/H abundance measurements. For this reanalyzed sample of systems, we obtain a weighted mean of (D/H){sub p} = (2.53 ± 0.04) × 10{sup –5}, corresponding to a universal baryon density 100 Ω{sub b,} {sub 0} h {sup 2} = 2.202 ± 0.046 for the standard model of big bang nucleosynthesis (BBN). By combining our measure of (D/H){sub p} with observations of the cosmic microwave background (CMB), we derive the effective number of light fermion species, N {sub eff} = 3.28 ± 0.28. We therefore rule out the existence of an additional (sterile) neutrino (i.e., N {sub eff} = 4.046) at 99.3% confidence (2.7σ), provided that the values of N {sub eff} and of the baryon-to-photon ratio (η{sub 10}) did not change between BBN and recombination. We also place a strong bound on the neutrino degeneracy parameter, independent of the {sup 4}He primordial mass fraction, Y {sub P}: ξ{sub D} = +0.05 ± 0.13 based only on the CMB+(D/H){sub p} observations. Combining this value of ξ{sub D} with the current best literature measure of Y {sub P}, we find a 2σ upper bound on the neutrino degeneracy parameter, |ξ| ≤ +0.062.

  3. Formation and retention of organically bound deuterium in rice in deuterium water release experiment.

    PubMed

    Atarashi-Andoh, Mariko; Amano, Hikaru; Kakiuchi, Hideki; Ichimasa, Michiko; Ichimasa, Yusuke

    2002-06-01

    As a substitute of tritium, deuterated water (D2O) vapor release experiments were performed in a greenhouse to estimate the different formation and subsequent retention of organically bound deuterium in rice plants between daytime and nighttime exposure. Potted rice plants were exposed to D2O vapor in the greenhouse for 8 h, under day or night conditions. Deuterium concentrations in free water and organic matter in rice leaves and ears were investigated until harvest time. The formation of organically bound deuterium in the daytime was higher than during the nighttime by the factors of 2.4 for the ear and 2.9 for the leaf. The decrease of the organically bound deuterium concentration in the ear after the nighttime exposure was faster than that after the daytime exposure. Data analysis was carried out using a compartment model in which different generating processes of organic matter were considered. The calculated organically bound deuterium retention in rice agreed with the measured value.

  4. Applications of deuterium oxide in human health.

    PubMed

    Bila, Wendell Costa; Mariano, Reysla Maria da Silveira; Silva, Valmin Ramos; Santos, Maria Emília Soares Martins Dos; Lamounier, Joel Alves; Ferriolli, Eduardo; Galdino, Alexsandro Sobreira

    2017-02-06

    The main aim goal of this review was to gather information about recent publications related to deuterium oxide (D2O), and its use as a scientific tool related to human health. Searches were made in electronic databases Pubmed, Scielo, Lilacs, Medline and Cochrane. Moreover, the following patent databases were consulted: EPO (Espacenet patent search), USPTO (United States Patent and Trademark Office) and Google Patents, which cover researches worldwide related to innovations using D2O.

  5. A crucial role of fractional occupation numbers of natural orbitals (NOs) in the description of double excitations in response time-dependent NO functional theory

    NASA Astrophysics Data System (ADS)

    Gritsenko, O. V.

    2017-09-01

    We demonstrate a crucial role of fractional occupation numbers (FONs) of natural orbitals (NOs) in the description of double excitations in time-dependent NO functional theory (TDNOFT). An analytical dependence of the double excitation energy ωα on the ratio of the FONs is derived in a model from the matrix diagonalization problem. In the large ratio Heitler-London limit the derived formula reproduces the correct asymptotics of ωα of the ionic state of double excitation character. In the small ratio Møller-Plesset, MP limit the reverse relation of static MP perturbation theory emerges in the dynamical response theory to provide ωα .

  6. Central Greenland Holocene Deuterium Excess Variability

    NASA Astrophysics Data System (ADS)

    Masson-Delmotte, V.; Jouzel, J.; Falourd, S.; Cattani, O.; Dahl-Jensen, D.; Johnsen, S.; Sveinbjornsdottir, A. E.; White, J. W. C.

    Water stable isotopes (oxygen 18 and deuterium) have been measured along the Holocene part of two deep ice cores from central Greenland, GRIP and North GRIP. Theoretical studies have shown that the second-order isotopic parameter, the deu- terium excess (d=dD-8d18O), is an indicator of climatic changes at the oceanic mois- ture source reflecting at least partly changes in sea-surface-temperature. The two deu- terium excess records from GRIP and North GRIP show a long term increasing trend already observed in Antarctic deep ice cores and related to changes in the Earth's obliquity during the Holocene : an decreased obliquity is associated with a larger low to high latitude annual mean insolation gradient, warmer tropics, colder poles, and a more intense atmospheric transport from the tropics to the poles, resulting in a higher moisture source temperature and higher deuterium excess values. Superimposed onto this long term trend, central Greenland deuterium excess records also exhibit small abrupt events (8.2 ka BP and 4.5 ka BP) and a high frequency variability.

  7. Is Deuterium Nuclear Fusion Catalyzed by Antineutrinos?

    NASA Astrophysics Data System (ADS)

    Shomer, Isaac

    2010-02-01

    The hypothesis of Fischbach and Jenkins that neutrinos emitted from the sun accelerate radioactive decay is noted. It is thought that neutrinos accelerate beta decay by reacting with neutron-rich nuclides to form a beta particle and a daughter product, with no antineutrino emitted. Conversely, it is proposed that antineutrinos can react with proton-rich nuclides to cause positron decay, with no neutrino emitted. It is also proposed that the nuclear fusion of the hydrogen bomb is triggered not only by the energy of the igniting fission bomb, but by the antineutrinos created by the rapid beta decay of the daughter products in the fission process. The contemplated mechanism for antineutrino initiated fusion is the following: 1. The antineutrinos from the fission daughter products cause positron decay of deuterium by the process outlined above. 2. In a later fusion step, these positrons subsequently react with neutrons in deuterium to create antineutrinos. Electrons are unavailable to annihilate positrons in the plasma of the hydrogen bomb. 3. These antineutrinos thereafter react with more deuterium to form positrons, thereby propagating a chain reaction. )

  8. HCl and DCl: a case study of different approaches for determining photo fractionation constants.

    PubMed

    Grage, Mette M-L; Nyman, Gunnar; Johnson, Matthew S

    2006-11-07

    The photoabsorption cross sections of HCl and DCl are calculated using the reflection principle and time dependent wavepacket propagation methods. The absorption cross sections are compared to high precision experimental absorption cross sections from the literature and the different results given by the methods are discussed. The results of the calculations emphasize the important roles that photodissociation dynamics and the change in transition dipole moment with internuclear distance play in isotopic fractionation. The wave number dependent fractionation constants have been determined. The process fractionation constant has been calculated in the Venusian atmosphere where photo-fractionation leads to enrichment in deuterium through loss of hydrogen to space. At an altitude of 70 km the process fractionation constant was found to be epsilon(p) = -344 per thousand and epsilon(p) = -256 per thousand for the experimental and the reflection principle methods, respectively. At the top of the atmosphere the process fractionation constant was evaluated to be epsilon(p) = -32 per thousand, epsilon(p) = -20 per thousand and epsilon(p) = -40 per thousand using the experimental data, the wavepacket and the reflection principle methods, respectively. Using the Rayleigh distillation formula it is concluded that HCl at the top of the Venusian atmosphere is fractionated (enriched in D) relative to the bulk composition prior to photolysis.

  9. CO2-dependent fractional crystallization of alkaline silicate magmas and unmixing of carbonatites within the intrusive complexes of Brava Island (Cape Verde)

    NASA Astrophysics Data System (ADS)

    Weidendorfer, D.; Schmidt, M. W.; Mattsson, H. B.

    2014-12-01

    Intrusive carbonatites often occur in intimate association with SiO2-undersaturated rocks such as melilitites, nephelinites, syenites and phonolites. The occurrence of carbonatites on five of the 10 main islands of the Cape Verde hotspot argues for a CO2-enriched mantle source. Whether alkali-poor carbonatites on the Cape Verdes directly represent small mantle melt fractions or form by extreme fractionation and/or liquid immiscibility from a CO2-rich silicate magma remains a matter of debate. This study focuses on the pyroxenites, nephelinites, ijolites, syenites, phonolites and carbonatites of the intrusive unit of Brava Island. This relative complete series allows for the deduction of a CO2-dependent fractionation pathway from the most primitive basanitic dikes towards phonolitic compositions through an ijolitic series. Major and trace element whole rock and mineral composition trends can be reproduced by fractionating a sequence of olivine, augite, perovskite, biotite, apatite, sodalite and FeTi-oxides, present as phenocrysts in the rocks corresponding to their fractionation interval. To reproduce the observed chemistry of the alkaline silicate rocks a total fractionation of ~87% is required. The melts evolve towards the carbonatite-silicate miscibility gap, an initial CO2 of 0.5 wt% would be sufficient to maintain CO2-saturation in the more evolved compositions. The modelled carbonatite compositions, conjugate to nepheline-syenites to phonolites, correspond well to the observed ones except for an alkali-enrichment with respect to the natural samples. The alkali-depleted nature of the small carbonatite intrusions and dikes on Brava is likely a consequence of fluid-release to the surrounding wall-rocks during crystallization, where fenitization can be observed. The trace element chemistry of primary carbonates and also cpx within both, the carbonatites and the associated silicate rocks, substantiates our fractionation model. Furthermore, carbonatite and silicate

  10. Evolution of dispersion in the cosmic deuterium abundance

    NASA Astrophysics Data System (ADS)

    Dvorkin, Irina; Vangioni, Elisabeth; Silk, Joseph; Petitjean, Patrick; Olive, Keith A.

    2016-05-01

    Deuterium is created during big bang nucleosynthesis, and, in contrast to the other light stable nuclei, can only be destroyed thereafter by fusion in stellar interiors. In this Letter, we study the cosmic evolution of the deuterium abundance in the interstellar medium (ISM) and its dispersion using realistic galaxy evolution models. We find that models that reproduce the observed metal abundance are compatible with observations of the deuterium abundance in the local ISM and z ˜ 3 absorption line systems. In particular, we reproduce the low astration factor which we attribute to a low global star formation efficiency. We calculate the dispersion in deuterium abundance arising from different structure formation histories in different parts of the Universe. Our model also predicts a tight correlation between deuterium and metal abundances which could be used to measure the primordial deuterium abundance.

  11. Dose-Dependent Effects of Focal Fractionated Irradiation on Secondary Malignant Neoplasms in Nf1 mutant mice

    PubMed Central

    Nakamura, Jean L; Phong, Connie; Pinarbasi, Emile; Kogan, Scott C; Vandenberg, Scott; Horvai, Andrew E; Faddegon, Bruce A; Fiedler, Dorothea; Shokat, Kevan; Houseman, Benjamin T; Chao, Richard; Pieper, Russell O; Shannon, Kevin

    2010-01-01

    Secondary malignant neoplasms (SMNs) are increasingly common complications of cancer therapy that have proven difficult to model in mice. Clinical observations suggest that the development of SMN correlates with radiation dose; however, this relationship has not been investigated systematically. We developed a novel procedure for administering fractionated cranial irradiation (CI) and investigated the incidence and spectrum of cancer in control and heterozygous Nf1 mutant mice irradiated to a moderate (15 Gy) or high dose (30 Gy). Heterozygous Nf1 inactivation cooperated with CI to induce solid tumors and myeloid malignancies, with mice developing many of the most common SMNs found in human patients. CI-induced malignancies segregated according to radiation dose as Nf1+/− mice developed predominately hematologic abnormalities after 15 Gy, while solid tumors predominated at 30 Gy, suggesting that radiation dose thresholds exist for hematologic and non-hematologic cancers. Genetic and biochemical studies revealed discrete patterns of somatic Nf1 and Trp53 inactivation and we observed hyperactive Ras signaling in many radiation-induced solid tumors. This technique for administering focal fractionated irradiation will facilitate mechanistic and translational studies of SMNs. PMID:21199799

  12. The effect of propylene glycol on the P450-dependent metabolism of acetaminophen and other chemicals in subcellular fractions of mouse liver

    SciTech Connect

    Snawder, J.E.; Benson, R.W.; Leakey, J.E.A.; Roberts, D.W. )

    1993-01-01

    Propylene glycol (PG) decreases the hepatotoxicity of acetominophen (APAP). To elucidate the mechanism for this response, the authors measured the effect of PG on the in vitro metabolism of APAP by subcellular liver fractions from 6-10 week-old male B6C3F1 mice. The fractions were assayed for their ability to bioactivate APAP to N-acetyl-p-benzoquinone imine, which was trapped as APAP-glutathione conjugates or APAP-protein adducts, and for dimethyl-nitrosamine-N-demethylase (DMN), 4-nitrophenol hydroxylase (4-NPOH), and phenacetin-O-deethylase (PAD) activities. Activity in the crude mitochondrial-rich (10,000 [times] g pellet) fraction was low and PG had no effect. PG inhibited DMN and 4-NPOH, indicators of IIE1-dependent activity, and the formation of APAP-glutathione conjugates and APAP-protein adducts in both heavy (15,000 [times] g pellet) and light (100,000 [times] g pellet) microsomes. PAD, a measure of IA2-dependent activity, was not inhibited. These data demonstrate that PG selectively inhibits IIE1 activity, including the bioactivation of APAP, and implicates this as the mechanism for PG-mediated protection of APAP hepatotoxicity in mice. 27 refs., 1 fig., 1 tab.

  13. Simultaneous experimental determination of labile proton fraction ratio and exchange rate with irradiation radio frequency power-dependent quantitative CEST MRI analysis.

    PubMed

    Sun, Phillip Zhe; Wang, Yu; Xiao, Gang; Wu, Renhua

    2013-01-01

    Chemical exchange saturation transfer (CEST) imaging is sensitive to dilute proteins/peptides and microenvironmental properties, and has been increasingly evaluated for molecular imaging and in vivo applications. However, the experimentally measured CEST effect depends on the CEST agent concentration, exchange rate and relaxation time. In addition, there may be non-negligible direct radio-frequency (RF) saturation effects, particularly severe for diamagnetic CEST (DIACEST) agents owing to their relatively small chemical shift difference from that of the bulk water resonance. As such, the commonly used asymmetry analysis only provides CEST-weighted information. Recently, it has been shown with numerical simulation that both labile proton concentration and exchange rate can be determined by evaluating the RF power dependence of DIACEST effect. To validate the simulation results, we prepared and imaged two CEST phantoms: a pH phantom of serially titrated pH at a fixed creatine concentration and a concentration phantom of serially varied creatine concentration titrated to the same pH, and solved the labile proton fraction ratio and exchange rate per-pixel. For the concentration phantom, we showed that the labile proton fraction ratio is proportional to the CEST agent concentration with negligible change in the exchange rate. Additionally, we found the exchange rate of the pH phantom is dominantly base-catalyzed with little difference in the labile proton fraction ratio. In summary, our study demonstrated quantitative DIACEST MRI, which remains promising to augment the conventional CEST-weighted MRI analysis.

  14. Isolation of CA1 nuclear enriched fractions from hippocampal slices to study activity-dependent nuclear import of synapto-nuclear messenger proteins.

    PubMed

    Yuanxiang, Pingan; Bera, Sujoy; Karpova, Anna; Kreutz, Michael R; Mikhaylova, Marina

    2014-08-10

    Studying activity dependent protein expression, subcellular translocation, or phosphorylation is essential to understand the underlying cellular mechanisms of synaptic plasticity. Long-term potentiation (LTP) and long-term depression (LTD) induced in acute hippocampal slices are widely accepted as cellular models of learning and memory. There are numerous studies that use live cell imaging or immunohistochemistry approaches to visualize activity dependent protein dynamics. However these methods rely on the suitability of antibodies for immunocytochemistry or overexpression of fluorescence-tagged proteins in single neurons. Immunoblotting of proteins is an alternative method providing independent confirmation of the findings. The first limiting factor in preparation of subcellular fractions from individual tetanized hippocampal slices is the low amount of material. Second, the handling procedure is crucial because even very short and minor manipulations of living slices might induce activation of certain signaling cascades. Here we describe an optimized workflow in order to obtain sufficient quantity of nuclear enriched fraction of sufficient purity from the CA1 region of acute hippocampal slices from rat brain. As a representative example we show that the ERK1/2 phosphorylated form of the synapto-nuclear protein messenger Jacob actively translocates to the nucleus upon induction of LTP and can be detected in a nuclear enriched fraction from CA1 neurons.

  15. Deuterium incorporation in biomass cell wall components by NMR analysis

    SciTech Connect

    Foston, Marcus B; McGaughey, Joseph; O'Neill, Hugh Michael; Evans, Barbara R; Ragauskas, Arthur J

    2012-01-01

    A commercially available deuterated kale sample was analyzed for deuterium incorporation by ionic liquid solution 2H and 1H nuclear magnetic resonance (NMR). This protocol was found to effectively measure the percent deuterium incorporation at 33%, comparable to the 31% value determined by combustion. The solution NMR technique also suggested by a qualitative analysis that deuterium is preferentially incorporated into the carbohydrate components of the kale sample.

  16. Microstructural studies of hydrogen and deuterium in bcc refractory metals

    SciTech Connect

    Moss, S.C.

    1980-01-01

    Over the past four years this research has been principally concerned with uncovering the microstructural atomic arrangements in alloys of hydrogen and deuterium with bcc refractory metals. Because these are interstitial phases in which the host metal lattice is substantially deformed by the incorporation of the H(D) atoms, there are pronounced x-ray scattering effects. X-ray diffraction has, therefore, been the main structural tool. A main objective of the project has been to determine the degree to which phase relations and solid solution properties in metal-hydride alloys depend upon the hydrogen-hydrogen interaction via the displacement field of the metal atoms. This has often included the elucidation of subtle thermodynamic properties which are revealed in structural studies.

  17. Pion Electroproduction form Helium 3, Deuterium, and Hydrogen

    SciTech Connect

    Avery, Stephen Milton

    2002-05-01

    A series of measurements for pion electroproduction from helium-3, deuterium, and hydrogen were completed at the Thomas Jefferson National Accelerator Facility by the NucPi Collaboration. E91003 began taking data in February 1998 and was completed in April 1998. The longitudinal and transverse parts of the differential cross section were extracted, by means of a Rosenbluth type separation, in the direction parallel to the virtual photon, at Q 2 = 0.4 GeV 2 , for W = 1.15 and W = 1.6 GeV. The mass dependence of the longitudinal cross section should provide insight into the surprising apparent absence of any significant cross section enhancement due to excess pions in the nuclear medium.

  18. Can in vitro metabolism-dependent covalent binding data distinguish hepatotoxic from nonhepatotoxic drugs? An analysis using human hepatocytes and liver S-9 fraction.

    PubMed

    Bauman, Jonathon N; Kelly, Joan M; Tripathy, Sakambari; Zhao, Sabrina X; Lam, Wing W; Kalgutkar, Amit S; Obach, R Scott

    2009-02-01

    In vitro covalent binding studies in which xenobiotics are shown to undergo metabolism-dependent covalent binding to macromolecules have been commonly used to shed light on the biochemical mechanisms of xenobiotic-induced toxicity. In this paper, 18 drugs (nine hepatotoxins and nine nonhepatotoxins) were tested for their proclivity to demonstrate metabolism-dependent covalent binding to macromolecules in human liver S-9 fraction (9000 g supernatant) or human hepatocytes, as an extension to previous work that used human liver microsomes published in this journal [ Obach et al. ( 2008 ) Chem. Res. Toxicol. 21 , 1814 -1822 ]. In the S-9 fraction, seven out of the nine drugs in each category demonstrated some level of metabolism-dependent covalent binding. Inclusion of reduced glutathione, cofactors needed by conjugating enzymes, and other parameters (total daily dose and fraction of total intrinsic clearance comprised by covalent binding) improved the ability of the system to separate hepatotoxins from nonhepatotoxins to a limited extent. Covalent binding in human hepatocytes showed that six out of the nine hepatotoxins and four out of eight nonhepatotoxins demonstrated covalent binding. Taking into account estimates of total daily body burden of covalent binding from the hepatocyte data showed an improvement over other in vitro systems for distinguishing hepatotoxins from nonhepatotoxins; however, this metabolism system still displayed some false positives. Combined with the previous study using liver microsomes, these findings identify the limitations of in vitro covalent binding data for prospective prediction of hepatotoxicity for new drug candidates and highlight the need for a better understanding of the link between drug bioactivation, covalent adduct formation, and toxicity outcomes. Directly relating covalent binding to hepatotoxicity is likely an oversimplification of the process whereby adduct formation ultimately leads to toxicity. Understanding underlying

  19. Measurements of the Branching Fraction and Time-Dependent CP Asymmetries of B0 to J/Psi pi0 Decays.

    SciTech Connect

    Aubert, B.

    2005-08-04

    The authors present measurements of the branching fraction and time-dependent CP asymmetries in B{sup 0} {yields} J/{psi} {pi}{sup 0} decays based on (231.8 {+-} 2.6) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC during the years 1999-2004. We obtain a branching fraction {Beta}(B{sup 0} {yields} J/{psi}{pi}{sup 0}) = (1.94 {+-} 0.22 (stat) {+-} 0.17 (syst)) x 10{sup -5}. They also measure the CP asymmetry parameters C = -0.21 {+-} 0.26 (stat) {+-} 0.09 (syst) and S = -0.68 {+-} 0.30 (stat) {+-} 0.04 (syst). All results presented in this paper are preliminary.

  20. Measurements of the Branching Fraction and Time-Dependent CP Asymmetries of B0 to J/Psi pi0 Decays

    SciTech Connect

    George, K

    2006-03-10

    We present measurements of the branching fraction and time-dependent CP asymmetries in B{sup 0} {yields} J/{psi}{pi}{sup 0} decays based on (231.8 {+-} 2.6) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We obtain a branching fraction {Beta}(B{sup 0} {yields} J/{psi}{pi}{sup 0}) = (1.94 {+-} 0.22 (stat) {+-} 0.17 (syst)) x 10{sup -5}. We also measure the CP asymmetry parameters C = -0.21 {+-} 0.26 (stat) {+-} 0.06 (syst) and S = -0.68 {+-} 0.30 (stat) {+-} 0.04 (syst).

  1. Note: Infrared laser diagnostics for deuterium gas puff Z pinches

    NASA Astrophysics Data System (ADS)

    Ivanov, V. V.; McKee, E. S.; Hammel, B. D.; Darling, T. W.; Swanson, K. J.; Covington, A. M.

    2017-07-01

    Deuterium gas puff Z pinches have been used for generation of strong neutron fluxes on the MA class pulse power machines. Due to the low electron density of deuterium Z-pinch plasma, regular laser diagnostics in the visible range cannot be used for observation and study of the pinch. Laser probing at the wavelength of 1064 nm was used for visualization of deuterium plasma. Infrared schlieren and interferometry diagnostics showed the deuterium gas puff plasma dynamics, instabilities, and allowed for the reconstruction of the profile of the plasma density.

  2. Chemical Behaviors of Energetic Deuterium Implanted into Boron Coatings

    SciTech Connect

    Kodama, H.; Morimoto, Y.; Sasaki, M.; Oyaidu, M.; Oya, Y.; Sagara, A.; Noda, N.; Okuno, K.

    2003-09-15

    To study chemical behaviors of energetic deuterium implanted into boron coating deposited by boronization in fusion devices, two types of boron coating film deposited on silicon and IG-430U were prepared by Plasma Chemical Vapor Deposition (PCVD) technique. Boron polycrystal was used as the reference sample. The chemical behavior of deuterium was investigated by XPS (X-ray photoelectron spectroscopy) and TDS (Thermal adsorption spectroscopy).The 1.0 keV D{sub 2}{sup +} ions were implanted into the samples and the deuterium desorption behavior was studied by TDS. The TDS spectra showed that there were two deuterium release peaks at around 550 and 750 K, which were attributed to the release from deuterium trapped by boron and carbon, respectively. It was also found that most of implanted deuterium was trapped in carbon trapping site compared with boron one.In XPS measurements, the chemical shift of B-1s towards positive side was observed in the film on IG-430U after D{sub 2}{sup +} ion implantation. However, no chemical shifts were found in the film on silicon and boron polycrystal. In highly concentrated boron materials, even if deuterium was implanted into the boron materials, the amount of B-D bond was too low to be measured by XPS. This suggests that deuterium implanted into highly pure boron materials wasn't almost trapped, so that the retention of deuterium in the boron materials would be reduced, compared that in carbon materials.

  3. Neutron production from puffing deuterium in plasma focus device

    SciTech Connect

    Kubes, P.; Cikhardt, J.; Kortanek, J.; Batobolotova, B.; Rezac, K.; Klir, D.; Kravarik, J.; Paduch, M.; Zielinska, E.; Surala, W.; Sadowski, M. J.; Scholz, M.; Karpinski, L.

    2014-08-15

    The current research has continued on the PF-1000 plasma focus device at the current of 2 MA by comparison of the shots with and without injected deuterium. The increase of the total neutron yield at the level of 10{sup 10}–10{sup 11} per shot was achieved after the compression of about 10 μg/cm of the deuterium from the gas-valve by about 46 μg/cm of the neon or deuterium plasma sheath. It increases five times at the decrease of the puffing deuterium mass to one-half. In shots with neon in the chamber and with puffing deuterium, a considerable decrease was confirmed of the soft X-ray emission in comparison with shots without deuterium injection. This decrease can be explained by the absence of the neon in the region of the compressed and hot plasma. The deuterium plasma from the gas-puff should then be confined in the internal structures both in the phase of implosion as well as during their formation and transformation. In shots with puffing deuterium, the evolution of instabilities in the plasma column was suppressed. The deuterium plasma has a higher conductance and better ability to form expressive and dense plasmoids and to transport the internal current in comparison with neon plasma. Neutrons were produced both at the initial phase of stagnation, as well as at a later time at the evolution of the constrictions and dense plasmoids.

  4. Isotopic effect of parametric instabilities during lower hybrid waves injection into hydrogen/deuterium plasmas

    NASA Astrophysics Data System (ADS)

    Zhao, Aihui; Gao, Zhe

    2017-01-01

    Based on the local dispersion relation, the parametric instability (PI) was numerically investigated for the injection of lower hybrid waves (LHWs) into hydrogen and deuterium plasmas separately. Numerical calculations under typical scrape-off layer parameters in tokamak plasmas show that both the unstable regions of the PI and the values of growth rates are close for two cases, in spite of the decaying channel of the ion sound quasimode or ion cyclotron quasimode (ICQM). These numerical results could be understood by the analyses based on the fluid model. Parameter dependences are also similar for hydrogen and deuterium plasmas. For example, the ICQM growth rate increases with an increasing density, a decreasing temperature, and a decreasing magnetic field in deuterium plasmas as it does in hydrogen plasmas. The isotopic effect of the PI during the LHW injection is weak. As a result, the lower hybrid current drive efficiency at a high density in deuterium plasmas cannot be much improved over hydrogen plasmas if the PI process dominates the behavior of LHWs at the plasma edge.

  5. Modulation of Intestinal Inflammation by Yeasts and Cell Wall Extracts: Strain Dependence and Unexpected Anti-Inflammatory Role of Glucan Fractions

    PubMed Central

    Jawhara, Samir; Habib, Khalid; Maggiotto, François; Pignede, Georges; Vandekerckove, Pascal; Maes, Emmanuel; Dubuquoy, Laurent; Fontaine, Thierry; Guerardel, Yann; Poulain, Daniel

    2012-01-01

    Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and β-glucan crude fractions prepared from Sc2 and highly purified β-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas β-glucan fraction was protective against both. Surprisingly, purified β-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that β-glucan fractions or pure β-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model. PMID

  6. Size Dependent Lipidomic Analysis of Urinary Exosomes from Patients with Prostate Cancer by Flow Field-Flow Fractionation and Nanoflow Liquid Chromatography-Tandem Mass Spectrometry.

    PubMed

    Yang, Joon Seon; Lee, Jong Cheol; Byeon, Seul Kee; Rha, Koon Ho; Moon, Myeong Hee

    2017-02-21

    Exosomes are membrane-bound extracellular vesicles involved in intercellular communication and tumor cell metastasis. In this study, flow field-flow fractionation (FlFFF) was utilized to separate urinary exosomes by size, demonstrating a significant difference in exosome sizes between healthy controls and patients with prostate cancer (PCa). Exosome fractions of different sizes were collected for microscopic analysis during an FlFFF run and evaluated with exosome marker proteins using Western blot analysis. The results indicated that exosomes of different sizes originated from different types of cells. Collected exosome fractions were further examined using nanoflow ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (nUPLC-ESI-MS/MS) for lipidomic analysis. A total of 162 lipids (from 286 identified) were quantified using a selected reaction monitoring (SRM) method. The overall amount of lipids increased by 1.5- to 2-fold in patients with PCa and degree of increase was more significant in the smaller fractions (diameter <150 nm) than in the larger ones (diameter >150 nm) some classes of lipids. In addition, neutral lipids like diacylglycerol (DAG) and triacylglycerol (TAG) decreased in all exosomes without size dependency. Moreover, a dramatic increase in 22:6/22:6-phosphatidylglycerol (PG) was observed and significant decrease in (16:0,16:0)- and (16:1, 18:1)-DAG species (nearly 5-fold) and high abundant TAG species (>2.5-fold) was observed in patients with PCa. The results of this study indicate that FlFFF can be employed for the high-speed screening of urinary exosome sizes in patients with PCa and lipidomic analysis of the fractionated exosomes has potential for developing and distinguishing biomarkers of PCa.

  7. Surface morphology and deuterium retention in tungsten exposed to low-energy, high flux pure and helium-seeded deuterium plasmas

    NASA Astrophysics Data System (ADS)

    Alimov, V. Kh; Shu, W. M.; Roth, J.; Sugiyama, K.; Lindig, S.; Balden, M.; Isobe, K.; Yamanishi, T.

    2009-12-01

    Blistering and deuterium retention in re-crystallized tungsten exposed to low-energy, high flux pure and helium-seeded D plasmas to a fluence of 1027 D m-2 have been examined with scanning electron microscopy, thermal desorption spectroscopy, and the D(3He,p)4He nuclear reaction at 3He energies varied from 0.69 to 4.0 MeV. In the case of exposure to pure D plasma (38 eV D-1), blisters with various shapes and sizes depending on the exposure temperature are found on the W surface. No blisters appear at temperatures above 700 K. The deuterium retention increases with the exposure temperature, reaching a maximum value of about 1022 D m-2 at 480 K, and then decreases as the temperature rises further. Seeding of 76 eV He ions into the D plasma significantly reduces the D retention at elevated temperatures and prevents formation of the blisters.

  8. Tempered fractional calculus

    SciTech Connect

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  9. Thermodynamic forward models to calculate P-T phase diagrams that reflect fractional equilibrium crystallisation of garnet in path-dependent reacting bulk rock chemistries

    NASA Astrophysics Data System (ADS)

    Klitscher, N.; Konrad-Schmolke, M.; Schildhauer, H.

    2012-04-01

    garnet growth along a series of P-T paths, representative for barrovian and subduction zone metamorphism in basaltic and felsic rock compositions in order to detect path-dependent P-T regions of limited or ceased garnet growth. With our approach it is possible to detect fields that are characterised by thermodynamic garnet destabilisation due to changing EBC as a result of fractional garnet crystallisation along typical P-T paths. The mapped areas of limited garnet growth occur in metapelitic as well as metabasaltic rocks and develop along barrovian but also high-pressure P-T paths. Such general thermodynamic forward models allow a better general interpretation of often observed garnet growth zonations resulting from fractional crystallisation and sluggish diffusional re-equilibration.

  10. omega-Aga IVA selectively inhibits the calcium-dependent fraction of the evoked release of [3H]GABA from synaptosomes.

    PubMed

    Sitges, M; Chiu, L M

    1995-09-01

    The effect of omega-Aga IVA, a P-type Ca2+ channel blocker, on the release of the inhibitory neurotransmitter GABA and on the elevation of Cai induced by depolarization was investigated in [3H]GABA and fura-2 preloaded mouse brain synaptosomes, respectively. Two strategies (i.e. 20 mM external K+ and veratridine) that depolarize by different mechanisms the preparation were used. High K+ elevates Cai and induces [3H]GABA release in the absence of external Na+ and in the presence of TTX, conditions that abolish veratridine induced responses. The effect of omega-Aga IVA on the Ca2+ and Na+ dependent fractions of the depolarization evoked release of [3H]GABA were separately investigated in synaptosomes depolarized with high K+ in the absence of external Na+ and with veratridine in the absence of external Ca2+, respectively. The Ca2+ dependent fraction of the evoked release of [3H]GABA and the elevation of Ca2+ induced by high K+ are markedly inhibited (about 50%) in synaptosomes exposed to omega-Aga IVA (300 nM) for 3 min before depolarization, whereas the Na+ dependent, Ca2+ independent carrier mediated release of [3H]GABA induced by veratridine, which is sensitive to verapamil and amiloride, is not modified by omega-Aga IVA. Our results indicate that an omega-Aga IVA sensitive type of Ca2+ channel is highly involved in GABA exocytosis.

  11. Dispersion in DLA metallicities and deuterium abundances

    NASA Astrophysics Data System (ADS)

    Dvorkin, Irina; Silk, Joseph; Vangioni, Elisabeth; Petitjean, Patrick; Olive, Keith A.

    2017-03-01

    Recent chemical abundance measurements of damped Lyman-alpha absorbers (DLAs) revealed a large intrinsic scatter in their metallicities. We discuss a semi-analytic model that was specifically designed to study this scatter by tracing the chemical evolution of the interstellar matter in small regions of the Universe with different mean density, from over- to underdense regions. It is shown that different histories of structure formation in these regions are reflected in the chemical properties of the proto-galaxies. We also address deuterium abundance measurements, which constitute a complementary probe of the star formation and infall histories.

  12. Lamb shift in the muonic deuterium atom

    SciTech Connect

    Krutov, A. A.; Martynenko, A. P.

    2011-11-15

    We present an investigation of the Lamb shift (2P{sub 1/2}-2S{sub 1/2}) in the muonic deuterium ({mu}D) atom using the three-dimensional quasipotential method in quantum electrodynamics. The vacuum polarization, nuclear-structure, and recoil effects are calculated with the account of contributions of orders {alpha}{sup 3}, {alpha}{sup 4}, {alpha}{sup 5}, and {alpha}{sup 6}. The results are compared with earlier performed calculations. The obtained numerical value of the Lamb shift at 202.4139 meV can be considered a reliable estimate for comparison with forthcoming experimental data.

  13. Neutron scattering kernel for solid deuterium

    NASA Astrophysics Data System (ADS)

    Granada, J. R.

    2009-06-01

    A new scattering kernel to describe the interaction of slow neutrons with solid deuterium was developed. The main characteristics of that system are contained in the formalism, including the lattice's density of states, the Young-Koppel quantum treatment of the rotations, and the internal molecular vibrations. The elastic processes involving coherent and incoherent contributions are fully described, as well as the spin-correlation effects. The results from the new model are compared with the best available experimental data, showing very good agreement.

  14. Deuterium and He-3 in cosmic rays

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.

    1989-01-01

    Observation of a large flux of antiprotons in cosmic rays prompted many to postulate new ideas relating to the origin and propagation of cosmic rays in the Galaxy, within the framework of the secondary hypothesis. Under this hypothesis, cosmic rays traverse a large amount of matter either in the source region or in the interstellar space. As a result, large amounts of deuterium and He-3 are also produced as a consequence of spallation of helium and heavier nuclei. In this paper, the spectra of these isotopes are derived, using various models for the propagation of cosmic rays and compare with the existing observations.

  15. Sulfur and oxygen isotope fractionation during sulfate reduction coupled to anaerobic oxidation of methane is dependent on methane concentration

    NASA Astrophysics Data System (ADS)

    Deusner, Christian; Holler, Thomas; Arnold, Gail L.; Bernasconi, Stefano M.; Formolo, Michael J.; Brunner, Benjamin

    2014-08-01

    to induce very large sulfur isotope fractionation between sulfate and sulfide (i.e. >60‰) and will drive the oxygen isotope composition of sulfate towards the sulfate-water oxygen isotope equilibrium value. Sulfur isotope fractionation by AOM-SR at gas seeps, where methane fluxes are high, will be much smaller (i.e. 20 to 40‰).

  16. Bifidobacterium animalis ssp. lactis BI07 modulates the tumor necrosis factor alpha-dependent imbalances of the enterocyte-associated intestinal microbiota fraction.

    PubMed

    Centanni, Manuela; Turroni, Silvia; Rampelli, Simone; Biagi, Elena; Quercia, Sara; Consolandi, Clarissa; Severgnini, Marco; Brigidi, Patrizia; Candela, Marco

    2014-08-01

    Using a previously developed in vitro model to characterize the enterocyte-adherent microbiota fraction, we explored the potential of the probiotic strain Bifidobacterium animalis ssp. lactis BI07 to modulate the inflammation-dependent dysbioses of the enterocyte-adherent microbiota from 12 healthy human donors. According to our findings, B. animalis ssp. lactis BI07 is effective in limiting the increase of pro-inflammatory pathobionts on the inflamed mucosal site, supporting the recovery of a mutualistic community. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. Stage-dependent and sex-dependent sensitivity to water-soluble fractions of fresh and weathered oil in the marine copepod Calanus finmarchicus.

    PubMed

    Jager, Tjalling; Altin, Dag; Miljeteig, Cecilie; Hansen, Bjørn Henrik

    2016-03-01

    Acute toxicity differs between species but also varies within a species. Important intraspecific factors are the exposure duration and properties of the animal such as life stage, sex, and physiological status. In the present study, the acute toxicity of water-soluble fractions (WSFs) from fresh and artificially weathered oil was followed over time in different life stages of the calanoid copepod Calanus finmarchicus, including adult males and females. The life stages differ in size but also in lipid content and physiology. To meaningfully compare the sensitivity of the different stages, the authors fitted a toxicokinetic-toxicodynamic (TKTD) model from the framework of the General Unified Threshold Model of Survival (GUTS) to the mortality patterns over time. The oil WSFs could not be treated as single compounds: the rapid effect at high doses could not be reconciled with the slow effect at low doses. Treating the oil as a mixture of 2 component blocks could, however, capture these patterns satisfactorily. Even though the early life stages of animals are generally considered to be the most vulnerable, the adult males of C. finmarchicus turned out to be most sensitive, followed by the early copepodites. Naupliar larvae were equally susceptible to oil toxicity as late copepodites and adult females. The relationship between the GUTS model parameters and the physiological traits for the different life stages remains, however, unclear.

  18. A Method for Partitioning the Attributable Fraction of Multiple Time-Dependent Coexisting Risk Factors for an Adverse Health Outcome

    PubMed Central

    Allore, Heather G.; McAvay, Gail; Tinetti, Mary E.; Gill, Thomas M.; Gross, Cary P.; Murphy, Terrence E.

    2013-01-01

    Objectives. We decomposed the total effect of coexisting diseases on a timed occurrence of an adverse outcome into additive effects from individual diseases. Methods. In a cohort of older adults enrolled in the Precipitating Events Project in New Haven County, Connecticut, we assessed a longitudinal extension of the average attributable fraction method (LE-AAF) to estimate the additive and order-free contributions of multiple diseases to the timed occurrence of a health outcome, with right censoring, which may be useful when relationships among diseases are complex. We partitioned the contribution to death into additive LE-AAFs for multiple diseases. Results. The onset of heart failure and acute episodes of pneumonia during follow-up contributed the most to death, with the overall LE-AAFs equal to 13.0% and 12.1%, respectively. The contribution of preexisting diseases decreased over the years, with a trend of increasing contribution from new onset of diseases. Conclusions. LE-AAF can be useful for determining the additive and order-free contribution of individual time-varying diseases to a time-to-event outcome. PMID:22515873

  19. Unraveling sterol-dependent membrane phenotypes by analysis of protein abundance-ratio distributions in different membrane fractions under biochemical and endogenous sterol depletion.

    PubMed

    Zauber, Henrik; Szymanski, Witold; Schulze, Waltraud X

    2013-12-01

    During the last decade, research on plasma membrane focused increasingly on the analysis of so-called microdomains. It has been shown that function of many membrane-associated proteins involved in signaling and transport depends on their conditional segregation within sterol-enriched membrane domains. High throughput proteomic analysis of sterol-protein interactions are often based on analyzing detergent resistant membrane fraction enriched in sterols and associated proteins, which also contain proteins from these microdomain structures. Most studies so far focused exclusively on the characterization of detergent resistant membrane protein composition and abundances. This approach has received some criticism because of its unspecificity and many co-purifying proteins. In this study, by a label-free quantitation approach, we extended the characterization of membrane microdomains by particularly studying distributions of each protein between detergent resistant membrane and detergent-soluble fractions (DSF). This approach allows a more stringent definition of dynamic processes between different membrane phases and provides a means of identification of co-purifying proteins. We developed a random sampling algorithm, called Unicorn, allowing for robust statistical testing of alterations in the protein distribution ratios of the two different fractions. Unicorn was validated on proteomic data from methyl-β-cyclodextrin treated plasma membranes and the sterol biosynthesis mutant smt1. Both, chemical treatment and sterol-biosynthesis mutation affected similar protein classes in their membrane phase distribution and particularly proteins with signaling and transport functions.

  20. Deuterium-depleted water has stimulating effects on long-term memory in rats.

    PubMed

    Mladin, Cristian; Ciobica, Alin; Lefter, Radu; Popescu, Alexandru; Bild, Walther

    2014-11-07

    Deuterium-depleted water (DDW) is a water which has a 6-7-fold less concentration of the naturally occurring deuterium (20-25ppm vs. 150ppm). While administrated for a longer period, it may reduce the concentration of deuterium throughout the body, thus activating cellular mechanisms which are depending on protons (channels, pumps, enzyme proteins). The aim of the present work was to study, for the first time in our knowledge, the possible influence of deuterium-depleted water (DDW) chronic administration in normal Wistar rats, as compared to a control group which received distilled water, on spatial working memory and the locomotor activity (as studied through Y-maze) or both short-term and long-term spatial memory (assed in radial 8 arms-maze task). Our results presented here showed no significant modifications in terms of spatial working memory (assessed through spontaneous alternation percentage) and locomotor activity (expressed through the number of arm entries) in Y-maze, as a result of DDW ingestion. Also, no significant differences between the DDW and control group were found in terms of the number of working memory errors in the eight-arm radial maze, as a parameter of short-term memory. Still, we observed a significant decrease for the number of reference memory errors in the DDW rats. In this way, we could speculate that the administration of DDW may generate an improvement of the reference memory, as an index of long-term memory. Thus, we can reach the conclusion that the change between the deuterium/hydrogen balance may have important consequences for the mechanisms that govern long-term memory, as showed here especially in the behavioral parameters from the eight-arm radial maze task.

  1. Fundamental limits to the accuracy of deuterium isotopes for identifying the spatial origin of migratory animals

    USGS Publications Warehouse

    Farmer, A.; Cade, B.S.; Torres-Dowdall, J.

    2008-01-01

    Deuterium isotope analyses have revolutionized the study of migratory connectivity because global gradients of deuterium in precipitation (??DP) are expressed on a continental scale. Several authors have constructed continental scale base maps of ??DP to provide a spatial reference for studying the movement patterns of migratory species and, although they are very useful, these maps present a static, 40-year average view of the landscape that ignores much underlying inter-annual variation. To more fully understand the consequences of this underlying variation, we analyzed the GNIP deuterium data, the source for all current ??DP maps, to estimate the minimum separation in ??DP (and latitude) necessary to conclude with a given level of confidence that distinct ??DP values represent different geographic sites. Extending analyses of ??DP successfully to deuterium in tissues of living organisms, e.g., feathers in migratory birds (??DF), is dependent on the existence of geographic separation of ??DP, where every geographic location has a distribution of values associated with temporal variability in ??DP. Analyses were conducted for three distinct geographic regions: North America, eastern North America (east of longitude 100??W), and Argentina. At the 80% confidence level, the minimum separation values were 12, 7, and 14?? of latitude (equivalent to 53, 31, and 32???) for North America, eastern North America, and Argentina, respectively. Hence, in eastern North America, for example, one may not be able to accurately assign individual samples to sites separated by less than about 7?? of latitude as the distributions of ??DP were not distinct at latitudes <7?? apart. Moreover, two samples that differ by less than 31??? cannot be confidently said to originate from different latitudes. These estimates of minimum separation for ??DP do not include other known sources of variation in feather deuterium (??D F) and hence are a first order approximation that may be useful, in

  2. A possible deuterium anomaly: Implications of the CH3D/CH4 mixing ratios in the atmospheres of Jupiter, Saturn, and Uranus

    NASA Technical Reports Server (NTRS)

    Lutz, Barry L.; Debergh, Catherine; Owen, Tobias

    1986-01-01

    Observations of CH3D in the atmospheres of the outer planets provide a test of the theory of deuterium fractionation equilibrium in the formation and evolution of these planets. Recent measurements of the CH3D/CH4 mixing ratios made for Saturn and Uranus are presented and intercompared with current values of Jupiter, illustrating large differences between the planets. Their implied D/H ratios are compared to D/H ratios derived from measurements of HD/H2; and, in the cases of Jupiter and Saturn, they may be incompatible. Implications of these comparisons are discussed in terms of the deuterium fractionation chemistry and possible enrichments of deuterium in the core ices of the planets.

  3. Cryotarget Control Software for Liquid Deuterium

    NASA Astrophysics Data System (ADS)

    Brakman, David; Gilfoyle, Gerard; Cuevas, Chris; Christo, Steve; CLAS Collaboration

    2015-10-01

    One of the experiments in Hall B at Jefferson Lab will measure the neutron elastic magnetic form factor with a 12 GeV electron beam striking a liquid deuterium target (LD2) and measuring the resulting debris in the CEBAF Large Acceptance Spectrometer (CLAS12). A program was created that acts as a control system for the LD2 target. It will monitor the deuterium target and send data to the main control system and the shift workers monitoring the experiment in real time. The data include measurements of pressure, temperature, and liquid level. The system will also control setpoints for temperature, heater power, and other parameters as well as download calibration curves. The program was written in LabVIEW, a graphical programming language noted for readily interfacing with lab equipment. This project has completed two stages so far. Simulated data were generated within LabVIEW and passed to subroutines that send, log, and display data on a PC. In the second stage, the PC was connected to a data acquisition board, and test signals were read and analyzed to simulate the target sensors. Work supported by the University of Richmond and the US Department of Energy.

  4. Cold versus hot fusion deuterium branching ratios

    SciTech Connect

    Fox, H.; Bass, R.

    1995-12-31

    A major source of misunderstanding of the nature of cold nuclear fusion has been the expectation that the deuterium branching ratios occurring within a palladium lattice would be consistent with the gas-plasma branching ratios. This misunderstanding has led to the concept of the dead graduate student, the 1989`s feverish but fruitless search for neutron emissions from cold fusion reactors, and the follow-on condemnation of the new science of cold fusion. The experimental facts are that in a properly loaded palladium lattice, the deuterium fusion produces neutrons at little above background, a greatly less-than-expected production of tritium (the tritium desert), and substantially more helium-4 than is observed in hot plasma physics. The experimental evidence is now compelling (800 reports of success from 30 countries) that cold nuclear fusion is a reality, that the branching ratios are unexpected, and that a new science is struggling to be recognized. Commercialization of some types of cold fusion devices has already begun.

  5. Muon capture in hydrogen and deuterium

    NASA Astrophysics Data System (ADS)

    Petitjean, Claude

    2009-09-01

    We report on a new generation of muon lifetime experiments at PSI to measure the nuclear muon capture rate in hydrogen and deuterium with ≤1% accuracy. The goals are to determine in μp capture the induced pseudoscalar coupling g P predicted in HBchPT, and in μd capture the axial two-body current term L1 A described by modern EFT’s. For the μp experiment a hydrogen TPC was developed as active muon stop detector, surrounded by cylindrical wire chambers and a plastic hodoscope as electron detector. Ultra-high purity of the hydrogen isotope ^1H_1 at levels below 10 - 8 was achieved with a specially developed gas circulation and purification system, and with a novel isotope separation column. About 2 ·1010 events were collected which are now in final analysis. Data from the first production run result in g P = 7.3 ± 1.1 in good agreement with theory. The μd experiment is in development. It requires measurements in ultra-pure, cold deuterium gas at ˜30K. For this we are constructing a new Cryo-TPC.

  6. Deuterium anions in inertial electrostatic confinement devices.

    PubMed

    Boris, D R; Alderson, E; Becerra, G; Donovan, D C; Egle, B; Emmert, G A; Garrison, L; Kulcinski, G L; Santarius, J F; Schuff, C; Zenobia, S J

    2009-09-01

    A magnetic deflection-energy analyzer and Faraday trap diagnostic have been used to make measurements of divergent deuterium anion flow in the inertial electrostatic confinement experiment at the University of Wisconsin-Madison (UW-IEC) [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, I. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)], a device to confine high-energy light ions in a spherically symmetric electrostatic potential well. Deuterium anion current densities as high as 8.5 microA/cm2 have been measured at the wall of the UW-IEC device, 40 cm from the surface of the device cathode with a detector assembly of admittance area 0.7 cm2. Energy spectra obtained using a magnetic deflection-energy analyzer diagnostic indicate the presence of D2(-), and D- ions produced through thermal electron attachment near the device cathode, as well as D- ions produced via charge-transfer processes between the anode and cathode of the device.

  7. Deuterium anions in inertial electrostatic confinement devices

    NASA Astrophysics Data System (ADS)

    Boris, D. R.; Alderson, E.; Becerra, G.; Donovan, D. C.; Egle, B.; Emmert, G. A.; Garrison, L.; Kulcinski, G. L.; Santarius, J. F.; Schuff, C.; Zenobia, S. J.

    2009-09-01

    A magnetic deflection-energy analyzer and Faraday trap diagnostic have been used to make measurements of divergent deuterium anion flow in the inertial electrostatic confinement experiment at the University of Wisconsin-Madison (UW-IEC) [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, I. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)], a device to confine high-energy light ions in a spherically symmetric electrostatic potential well. Deuterium anion current densities as high as 8.5μA/cm2 have been measured at the wall of the UW-IEC device, 40 cm from the surface of the device cathode with a detector assembly of admittance area 0.7cm2 . Energy spectra obtained using a magnetic deflection-energy analyzer diagnostic indicate the presence of D2- , and D- ions produced through thermal electron attachment near the device cathode, as well as D- ions produced via charge-transfer processes between the anode and cathode of the device.

  8. Confinement and heating of a deuterium-tritium plasma

    SciTech Connect

    Hawryluk, R. J.; Adler, H.; Alling, P.; Synakowski, E.

    1994-03-01

    The Tokamak Fusion Test Reactor (TFTR) has performed initial high-power experiments with the plasma fueled by deuterium and tritium to nominally equal densities. Compared to pure deuterium plasmas, the energy stored in the electron and ions increased by ~20%. These increases indicate improvements in confinement associated with the use of tritium and possibly heating of electrons by α-particles.

  9. Deuterium enrichment by selective photoinduced dissociation of a multihalogenated organic compound

    DOEpatents

    Marling, John B.; Herman, Irving P.

    1981-01-01

    A method for deuterium enrichment by photoinduced dissociation which uses as the deuterium source a multihalogenated organic compound selected from the group consisting of a dihalomethane, a trihalomethane, a 1,2-dihaloethene, a trihaloethene, a tetrahaloethane and a pentahaloethane. The multihalogenated organic compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of substantially only those molecules containing deuterium to provide a deuterium enriched dissociation product. The deuterium enriched product may be combusted with oxygen to provide deuterium enriched water. The deuterium depleted undissociated molecules may be redeuterated by treatment with a deuterium source such as water.

  10. Spatial Variation of Deuterium Enrichment in Bulk Water of Snowgum Leaves1[OA

    PubMed Central

    Šantrůček, Jiří; Květoň, Jiří; Šetlík, Jiří; Bulíčková, Lenka

    2007-01-01

    Deuterium enrichment of bulk water was measured and modeled in snowgum (Eucalyptus pauciflora Sieber ex Sprengel) leaves grown under contrasting air and soil humidity in arid and wet conditions in a glasshouse. A map of the enrichment was constructed with a resolution of 4 mm by using a newly designed cryodistillation method. There was progressively increasing enrichment in both longitudinal (along the leaf midrib) and transversal (perpendicular to the midrib) directions, most pronounced in the arid-grown leaf. The whole-leaf average of the enrichment was well below the value estimated by the Craig-Gordon model. The discrepancy between model and measurements persisted when the estimates were carried out separately for the leaf base and tip, which differed in temperature and stomatal conductance. The discrepancy was proportional to the transpiration rate, indicating the significance of diffusion-advection interplay (Péclet effect) of deuterium-containing water molecules in small veins close to the evaporating sites in the leaf. Combined Craig-Gordon and desert-river models, with or without the Péclet number, P, were used for predicting the leaf longitudinal enrichment. The predictions without P overestimated the measured values of δdeuterium. Fixed P value partially improved the coincidence. We suggest that P should vary along the leaf length l to reconcile the modeled data with observations of longitudinal enrichment. Local values of P, P(l), integrating the upstream fraction of water used or the leaf area, substantially improved the model predictions. PMID:17158587

  11. Tables of equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium

    NASA Astrophysics Data System (ADS)

    Zaghloul, Mofreh R.

    2015-11-01

    We present computational results and tables of the equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium. The present results are generated using a recently developed chemical model that takes into account different high density effects such as Coulomb interactions among charged particles, partial degeneracy, and intensive short range hard core repulsion. Internal partition functions are evaluated in a statistical-mechanically consistent way implementing recent developments in the literature. The shock Hugoniot curve derived from the present tables is overall in reasonable agreement with the Hugoniot derived from the Nova-laser shock wave experiments on liquid deuterium, showing that deuterium has a significantly higher compressibility than predicted by the SESAME tables or by Path Integral Monte Carlo calculations. Computational results are presented as surface plots for the dissociated fraction, degree of ionization, pressure, and specific internal energy for densities ranging from 0.0001 to 40 g/cm3 and temperatures from 2000 to ˜106 K. Tables for values of the above mentioned quantities in addition to the specific heat at constant pressure, cp, ratio of specific heats, cp/cv, sound speed and Hugoniot curve (for a specific initial state) are presented for practical use.

  12. Precise measurement of total body water using trace quantities of deuterium oxide.

    PubMed

    Halliday, D; Miller, A G

    1977-04-01

    This study was undertaken to investigate the possibility of measuring total body water in human subjects to better than +/-0.5%. Accurate serial estimates of total body water were required to complement densitometric and anthropometric measurements used to monitor body compositional changes in obese patients undergoing dietary or surgical weight reduction therapy. The method required the oral administration of 1-2 g of deuterium oxide and the analysis of pre-dose and respective equilibrated samples of urine, plasma or saliva. The sample size required for analysis was 5 microliter and the conversion of gaseous phase was accomplished using a uranium reduction furnace. Isotopic enrichment of samples was measured using a mass spectrometer incorporating several features designed to cope with problems inherent in H2/H2H isotopic analysis. Reproducibility of sample preparation and accuracy of the mass spectrometer were tested using international standards and shown to give an overall sensitivity of 2 parts in 10(7) for the determination of deuterium in H2O/H2HO mixtures. This precision has enabled us to demonstrate that isotopic fractionation of deuterium with respect to hydrogen occurs within the body and expands the potential use of this isotope for quantitative biochemical studies in the human subject.

  13. Tables of equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium

    SciTech Connect

    Zaghloul, Mofreh R.

    2015-11-15

    We present computational results and tables of the equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium. The present results are generated using a recently developed chemical model that takes into account different high density effects such as Coulomb interactions among charged particles, partial degeneracy, and intensive short range hard core repulsion. Internal partition functions are evaluated in a statistical-mechanically consistent way implementing recent developments in the literature. The shock Hugoniot curve derived from the present tables is overall in reasonable agreement with the Hugoniot derived from the Nova-laser shock wave experiments on liquid deuterium, showing that deuterium has a significantly higher compressibility than predicted by the SESAME tables or by Path Integral Monte Carlo calculations. Computational results are presented as surface plots for the dissociated fraction, degree of ionization, pressure, and specific internal energy for densities ranging from 0.0001 to 40 g/cm{sup 3} and temperatures from 2000 to ∼10{sup 6 }K. Tables for values of the above mentioned quantities in addition to the specific heat at constant pressure, c{sub p}, ratio of specific heats, c{sub p}/c{sub v}, sound speed and Hugoniot curve (for a specific initial state) are presented for practical use.

  14. The structure of liquid and supercritical deuterium fluoride from neutron scattering using high-pressure techniques

    NASA Astrophysics Data System (ADS)

    Pfleiderer, Till; Waldner, Isabella; Bertagnolli, Helmut; Tödheide, Klaus; Fischer, Henry E.

    2000-09-01

    We present neutron diffraction data for deuterium fluoride at two liquid and four supercritical states in the temperature range of 300-473 K and for pressures up to 320 bar, spanning a factor of 4 in sample density. The intra- and intermolecular parts of the measured structure factors were separated and conclusions about the temperature and density dependence of the intra- and intermolecular structure are deduced. 2000 American Institute of Physics.

  15. Effect of Deuterium Interactions with Lattice Defects on Superconducting PdDx System

    NASA Astrophysics Data System (ADS)

    Yasuzuka, Syuma; Ogita, Norio; Anzai, Daichi; Hatakenaka, Noriyuki

    2016-12-01

    Results are presented for the current-voltage characteristics of PdDx, which shows a partial superconducting (SC) transition at Tc ˜ 7 K. The temperature dependence of the critical current is well fitted by the Ambegaokar-Baratoff relation, suggesting the existence of Josephson junctions between the SC grains. The effect of deuterium interactions with defects on the SC state in the PdDx system is discussed.

  16. TEMPERED FRACTIONAL CALCULUS

    PubMed Central

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2014-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series. PMID:26085690

  17. Calcium-dependent isolation of the 36-kilodalton substrate of pp60/sup src/-kinase. Fractionation of the phosphorylated and unphosphorylated species

    SciTech Connect

    Soric, J.; Gordon, J.A.

    1986-11-05

    In this paper, the authors present a new and simple purification of the 36-kDa protein, a major substrate of both viral and growth factor-receptor associated tyrosine protein kinases, and its complex from normal and Schmidt-Ruppin strain Rous sarcoma virus-transformed chicken embryo fibroblasts that employs a DEAE-Sephacel column and introduces the calcium-dependent adsorption of 36-kDa protein. The use of EGTA step gradients differentially elutes the 36-kDa molecules from the DEAE-Sephacel column. An average total yield of the 36-kDa protein in all fractions approached 80% and represented 0.78% of the (/sup 35/S)methionine-labeled cellular protein. A purity of 95-99% was obtained with a yield of 60% in the central elution fractions from normal or Rous sarcoma virus-transformed chicken embryo fibroblasts. Furthermore, 2 mM EGTA elutes poorly phosphorylated molecules while heavily phosphorylated 36-kDa protein requires 4 or 6 M EGTA; a small residual fraction is released at 8-10 mM EGTA. If the EGTA step gradients were neutralized with Ca/sup 2 +/ ion, elution of the 36-kDa protein is inhibited. Tyrosine phosphorylation of the 36-kDa protein is increased 2-3-fold following a short term incubation of whole cells with micromolar vanadate. The elution pattern (but not intensity) of the 36-kDa protein obtained from lysates of vanadate-treated cells was identical to untreated cell lysates. The additional phosphorylation appears to result from a recruitment of unphosphorylated 36-kDa protein as the position (but not intensity) of the phosphorylated tryptic peptides is unchanged. They conclude that the function of the 36-kDa protein may be calcium ion-dependent and may be influenced by the phosphorylation state of the protein.

  18. Isotope fractionation

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A rash of new controversy has emerged around the subject of mass-independent isotope fractionation effects, particularly in the case of the oxygen isotopes. To be sure, the controversy has been around for awhile, but it has been given new impetus by the results of a recent study by Mark H. Thiemens and John E. Heidenreich III of the University of California, San Diego (Science, March 4, 1983).Gustav Arrhenius has been trying to convince the planetary science community that chemical effects in isotope fractionation processes could explain observations in meteorites that appear to be outside of the traditionally understood mass-dependent fractionations (G. Arrhenius, J . L. McCrumb, and N. F. Friedman, Astrophys. Space Sci, 65, 297, 1974). Robert Clayton had made the basic observations of oxygen in carbonaceous chondrites that the slope of the δ17 versus δ18 line was 1 instead of the slope of ½ characteristic of terrestrial rocks and lunar samples (Ann. Rev. Nucl. Part. Sci., 28, 501, 1978). The mass-independent effects were ascribed to the apparent contribution of an ancient presolar system component of O16.

  19. Deuterium Enrichment of Amino and Hydroxy Acids Found in the Murchison Meteorite: Constraints on Parent Body Conditions

    NASA Technical Reports Server (NTRS)

    Lerner, Narcinda R.; Chang, Sherwood (Technical Monitor)

    1997-01-01

    The alpha-amino and alpha-hydroxy acids found in the Murchison carbonaceous chondrite are deuterium enriched. These compounds are thought to have originated from common deuterium enriched carbonyl precursors, by way of a Strecker synthesis which took place in a solution of HCN, NH3, and carbonyl compounds during the period of aqueous alteration of the meteorite parent body. However, the hydroxy acids found on Murchison are less deuterium enriched than the amino acids. With the objective of determining if the discrepancy in deuterium enrichment between the amino acids and the hydroxy acids found on Murchison is consistent with their formation in a Strecker synthesis, we have measured the deuterium content of alpha-amino and alpha-hydroxy acids produced in solutions of deuterated carbonyl compounds, KCN and NH4Cl, and also in mixtures of such solutions and Allende dust at 263 K and 295 K. Retention of the isotopic signature of the starting carbonyl by both alpha amino acids and alpha hydroxy acids is more dependent upon temperature, concentration and pH than upon the presence of meteorite dust in the solution. The constraints these observations place on Murchison parent body conditions will be discussed.

  20. Brief early-life non-specific incorporation of deuterium extends mean life span in Drosophila melanogaster without affecting fecundity.

    PubMed

    Hammel, Stephanie C; East, Kyle; Shaka, A J; Rose, Michael R; Shahrestani, Parvin

    2013-04-01

    We have investigated the effects of brief, non-specific deuteration of Drosophila melanogaster by including varying percentages of ²H (D) in the H₂O used in the food mix consumed during initial development. Up to 22.5% deuterium oxide (D₂O) in H₂O was administered, with the result that a low percentage of D₂O in the water increased mean life span, whereas the highest percentage used (22.5%) reduced life span. After the one-time treatment period, adult flies were maintained ad libitum with food of normal isotopic distribution. At low deuterium levels, where life span extension was observed, there was no observed change in fecundity. Dead flies were assayed for deuterium incorporation by complete hydrolysis in hot 12 N HCl solution followed by subsequent high-performance liquid chromatography/mass spectrometry (HPLC/MS). Isoleucine and leucine residues showed a small, linear dose-dependent incorporation of deuterium at non-exchangeable sites. Although high levels of D₂O itself are toxic for other reasons, higher levels of deuterium incorporation, which can be achieved without toxicity by strategies that avoid direct use of D₂O, are clearly worth exploring.

  1. Influence of displacement damage on deuterium and helium retention in austenitic and ferritic-martensitic alloys considered for ADS service

    NASA Astrophysics Data System (ADS)

    Voyevodin, V. N.; Karpov, S. A.; Kopanets, I. E.; Ruzhytskyi, V. V.; Tolstolutskaya, G. D.; Garner, F. A.

    2016-01-01

    The behavior of ion-implanted hydrogen (deuterium) and helium in austenitic 18Cr10NiTi stainless steel, EI-852 ferritic steel and ferritic/martensitic steel EP-450 and their interaction with displacement damage were investigated. Energetic argon irradiation was used to produce displacement damage and bubble formation to simulate nuclear power environments. The influence of damage morphology and the features of radiation-induced defects on deuterium and helium trapping in structural alloys was studied using ion implantation, the nuclear reaction D(3He,p)4He, thermal desorption spectrometry and transmission electron microscopy. It was found in the case of helium irradiation that various kinds of helium-radiation defect complexes are formed in the implanted layer that lead to a more complicated spectra of thermal desorption. Additional small changes in the helium spectra after irradiation with argon ions to a dose of ≤25 dpa show that the binding energy of helium with these traps is weakly dependent on the displacement damage. It was established that retention of deuterium in ferritic and ferritic-martensitic alloys is three times less than in austenitic steel at damage of ˜1 dpa. The retention of deuterium in steels is strongly enhanced by presence of radiation damages created by argon ion irradiation, with a shift in the hydrogen release temperature interval of 200 K to higher temperature. At elevated temperatures of irradiation the efficiency of deuterium trapping is reduced by two orders of magnitude.

  2. Origin of the Deuterium Enrichment in the Solar System

    NASA Astrophysics Data System (ADS)

    Lecluse, C.; Robert, F.

    1992-07-01

    The present-day D/H ratio of the solar system is well known. In meteorites, water is under the form of -OH bearing minerals with D/H ratio lying in the range 140.10^-6 to 180.10^-6. On the Earth, the D/H ratio of water is close to 155.10^-6. Such a value demonstrates clearly the common origin of water on Earth and in meteorites. The giant planets, which are assumed to have kept the primordial molecular hydrogen from the protosolar nebula have a ratio close to 30.10^-6. The aim of the present work is to determine if it is possible to obtain, via isotopic exchange processes, a meteorite-like D/H ratio during the life-time of the nebula. Thus isotopic exchange rate constants for the hydrogen-water and hydrogen-methane reactions were measured: HD + H2O <--> H2 + HDO & HD + CH4 <--> H2 + CH3D D2O-H2 and CD4-H2 mixtures were prepared at several temperatures and pressures. After the reaction, molecular hydrogen is separated cryogenically from CD4 or D2O. Hydrogen is analyzed by mass spectrometry. The duration and the temperature of these experiments permit a precise determination of the rate constants. Catalytic effects were also studied, on SiO2, clays and organic polymers: exchange rates do not markedly increase relative to those determined without catalysts. Based on our present data, several numerical applications to the nebula were performed using Cameron's model [1] with the following parameters: total H2 pressure in the nebula between 10^-3 and 10^-4 atm for 1 to 3 A.U.; life-time of the nebula: 30 m.y.; maximum temperature reached by the nebula: 1300 K; cooling rate: t(sub)1/2 ranging from 3 to 6.10^6 years; initial D/H ratio in hydrogen: 30.10^-6. These calculations led us to the following conclusions: 1) Deuterium exchange with CH4 is always slower than with H2O. 2) The maximum deuterium enrichment depends markedly on the total pressure in the nebula. 3) Deuterium enrichments similar to those measured in carbonaceous chondrites can be reached for distances from

  3. Influence of the tritium beta(-) decay on low-temperature thermonuclear burn-up in deuterium-tritium mixtures

    PubMed

    Frolov

    2000-09-01

    Low-temperature (Tdeuterium-tritium mixtures with various deuterium-tritium-helium-3 ratios is considered. The general dependence is studied for the critical burn-up parameter x(c)=rhor(c) upon the initial temperature T, density rho(0), and tritium molar concentration y for the [D]:y[T]:(1-y)[3He] mixture. In particular, it is shown that, if the tritium concentration y decreases, then the critical burn-up parameter x(c)(T,rho(0),y) grows very quickly (at fixed T and rho(0)). This means that tritium beta(-) decay significantly complicates thermonuclear burn-up in deuterium-tritium mixtures.

  4. Determination of degradation rates of organic substances in the unsaturated soil zone depending on the grain size fractions of various soil types

    NASA Astrophysics Data System (ADS)

    Fichtner, Thomas; Stefan, Catalin; Goersmeyer, Nora

    2015-04-01

    Rate and extent of the biological degradation of organic substances during transport through the unsaturated soil zone is decisively influenced by the chemical and physical properties of the pollutants such as water solubility, toxicity and molecular structure. Furthermore microbial degradation processes are also influenced by soil-specific properties. An important parameter is the soil grain size distribution on which the pore volume and the pore size depends. Changes lead to changes in air and water circulation as well as preferred flow paths. Transport capacity of water inclusive nutrients is lower in existing bad-drainable fine pores in soils with small grain size fractions than in well-drainable coarse pores in a soil with bigger grain size fractions. Because fine pores are saturated with water for a longer time than the coarse pores and oxygen diffusion in water is ten thousand times slower than in air, oxygen is replenished much slower in soils with small grain size fractions. As a result life and growth conditions of the microorganisms are negatively affected. This leads to less biological activity, restricted degradation/mineralization of pollutants or altered microbial processes. The aim of conducted laboratory column experiments was to study the correlation between the grain size fractions respectively pore sizes, the oxygen content and the biodegradation rate of infiltrated organic substances. Therefore two columns (active + sterile control) were filled with different grain size fractions (0,063-0,125 mm, 0,2-0,63 mm and 1-2 mm) of soils. The sterile soil was inoculated with a defined amount of a special bacteria culture (sphingobium yanoikuae). A solution with organic substances glucose, oxalic acid, sinaphylic alcohol and nutrients was infiltrated from the top in intervals. The degradation of organic substances was controlled by the measurement of dissolved organic carbon in the in- and outflow of the column. The control of different pore volumes

  5. Gallic Acid Enriched Fraction of Phyllanthus emblica Potentiates Indomethacin-Induced Gastric Ulcer Healing via e-NOS-Dependent Pathway.

    PubMed

    Chatterjee, Ananya; Chatterjee, Sirshendu; Biswas, Angshuman; Bhattacharya, Sayanti; Chattopadhyay, Subrata; Bandyopadhyay, Sandip K

    2012-01-01

    The healing activity of gallic acid enriched ethanolic extract (GAE) of Phyllanthus emblica fruits (amla) against the indomethacin-induced gastric ulceration in mice was investigated. The activity was correlated with the ability of GAE to alter the cyclooxygenase- (COX-) dependent healing pathways. Histology of the stomach tissues revealed maximum ulceration on the 3rd day after indomethacin (18 mg/kg, single dose) administration that was associated with significant increase in inflammatory factors, namely, mucosal myeloperoxidase (MPO) activity and inducible nitric oxide synthase (i-NOS) expression. Proangiogenic parameters such as the levels of prostaglandin (PG) E(2), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), von Willebrand Factor VIII, and endothelial NOS (e-NOS) were downregulated by indomethacin. Treatment with GAE (5 mg/kg/day) and omeprazole (3 mg/kg/day) for 3 days led to effective healing of the acute ulceration, while GAE could reverse the indomethacin-induced proinflammatory changes of the designated biochemical parameters. The ulcer healing activity of GAE was, however, compromised by coadministration of the nonspecific NOS inhibitor, N-nitro-L-arginine methyl ester (L-NAME), but not the i-NOS-specific inhibitor, L-N6-(1-iminoethyl) lysine hydrochloride (L-NIL). Taken together, these results suggested that the GAE treatment accelerates ulcer healing by inducing PGE(2) synthesis and augmenting e-NOS/i-NOS ratio.

  6. Deuterium enrichment of polycyclic aromatic hydrocarbons by photochemically induced exchange with deuterium-rich cosmic ices

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.; Bernstein, M. P.; Allamandola, L. J.; Gillette, J. S.; Zare, R. N.

    2000-01-01

    The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly exchanges its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. Exchange occurs via three different chemical processes: D atom addition, D atom exchange at oxidized edge sites, and D atom exchange at aromatic edge sites. Observed exchange rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These exchange mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.

  7. Deuterium enrichment of polycyclic aromatic hydrocarbons by photochemically induced exchange with deuterium-rich cosmic ices

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.; Bernstein, M. P.; Allamandola, L. J.; Gillette, J. S.; Zare, R. N.

    2000-01-01

    The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly exchanges its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. Exchange occurs via three different chemical processes: D atom addition, D atom exchange at oxidized edge sites, and D atom exchange at aromatic edge sites. Observed exchange rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These exchange mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.

  8. The Triple-point Temperature of Pure Equilibrium Deuterium

    NASA Astrophysics Data System (ADS)

    Pavese, F.; McConville, G. T.

    1987-01-01

    A study specifically intended to measure the triple-point temperature of both n-D2 and e-D2 containing a volume fraction of HD not higher than 0.0001 has been completed. It was performed by measuring samples of gas in metal sealed cells. The cells, after being checked for a non-increasing HD contamination within the stated limits, were filled by directly connecting them to the outlet of a thermal-diffusion column for isotopic separation, known to produce D2 with a HD volume fraction not larger than 0.00003. In the case of e-D2, additional studies were performed on the effect of deuterating the catalyst or on high-temperature activation of the catalyst. Results proved that it is possible to obtain good results for e-D2 with partially deuterated catalyst, but this does not allow a reliable control of the contamination. An alternative procedure to full deuteration has been found, which uses commercial hydrous ferric oxide heated to about 400 °C, and commercially available deuterium, produced by isotopic separation and showing a purity better than 99.99%. Temperature values (18.7327 +/- 0.0003) K for n-D2 and (18.6983 +/- 0.0003) K for e-D2 on NPL-IPTS-68 were obtained at the liquidus point; the best thermodynamic values for these triple points are (18.7232 +/- 0.001) K and (18.6888 +/- 0.001) K respectively; e-D2 can be used as a first-quality temperature reference point.

  9. Ions in a binary asymmetric dipolar mixture: mole fraction dependent Born energy of solvation and partial solvent polarization structure.

    PubMed

    Kashyap, Hemant K; Biswas, Ranjit

    2007-11-14

    Mean spherical approximation (MSA) for electrolyte solution has been extended to investigate the role of partial solvent polarization densities around an ion in a completely asymmetric binary dipolar mixture. The differences in solvent diameters, dipole moments, and ionic size are incorporated systematically within the MSA framework in the present theory for the first time. In addition to the contributions due to difference in dipole moments, the solvent-solvent and ion-solvent size ratios are found to significantly affect the nonideality in binary dipolar mixtures. Subsequently, the theory is used to investigate the role of ion-solvent and solvent-solvent size ratios in determining the nonideality in Born free energy of solvation of a unipositive rigid ion in alcohol-water and dimethyl sulfoxide-acetonitrile mixtures, where the solvent components are represented only by their molecular diameters and dipole moments. Nonideality in Born free energy of solvation in such simplified mixtures is found to be stronger for smaller ions. The slope of the nonideality for smaller alkali metal ions in methanol-water mixture is found to be opposite to that for larger ion, such as quaternary tertiary butyl ammonium ion. For ethanol-water mixtures, the slopes are in the same direction for all the ions studied here. These results are in qualitative agreement with experiments, which is surprising as the present MSA approach does not include the hydrogen bonding and hydrophobic interactions present in the real mixtures. The calculated partial polarization densities around a unipositive ion also show the characteristic deviation from ideality and reveal the microscopic origin of the ion and solvent size dependent preferential solvation. Also, the excess free energy of mixing (in the absence of any ion) for these binary mixtures has been calculated and a good agreement between theory and experiment has been found.

  10. [Biological significance of naturally occurring deuterium: the antitumor effect of deuterium depletion].

    PubMed

    Somlyai, Gábor; Molnár, Miklós; Laskay, Gábor; Szabó, Mariann; Berkényi, Tamás; Guller, Imre; Kovács, András

    2010-09-05

    The concentration of deuterium is about 150 ppm (over 16 mmol/L) in surface water and more than 10 mmol/L in living organisms. Experiments with deuterium depleted water (30+/-5 ppm) revealed that due to D-depletion various tumorous cell lines (PC-3, human prostate, MDA, human breast, HT-29, human colon, M14, human melanoma) required longer time to multiply in vitro. DDW caused tumor regression in xenotransplanted mice (MDA and MCF-7, human breast, PC-3) and induced apoptosis in vitro and in vivo. Deuterium depleted water (25+/-5 ppm) induced complete or partial tumor regression in dogs and cats with spontaneous malignancies, it was registered as anticancer for veterinary use in 1999 (Vetera-DDW-25 A.U.V., 13/99 FVM). The hypodermic preparation of the registered veterinary drug was successfully tested in clinical investigations. Under the permission of the Hungarian Institute of Pharmacology (No. 5621/40/95) a randomized, double blind controlled, human Phase II clinical trial with prostate cancer was performed, in compliance with GCP principles, which exhibited a significant difference between the control and treated groups with respect to the examined parameters, median survival time and the extension of life-span. We suggest that cells are able to regulate the D/H ratio and the changes in the D/H ratio can trigger certain molecular mechanisms having a key role in cell cycle regulation. We suppose that not the shift in the intracellular pH, but the concomitant increase in the D/H ratio is the real trigger for the cells to enter into S phase. The decrease of D concentration can intervene in the signal transduction pathways thus leading to tumor regression. Deuterium depletion may open new perspectives in cancer treatment and prevention helping to increase the effectiveness of current oncotherapies.

  11. Ignition of deuterium-trtium fuel targets

    DOEpatents

    Musinski, Donald L.; Mruzek, Michael T.

    1991-01-01

    A method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom.

  12. Ignition of deuterium-tritium fuel targets

    DOEpatents

    Musinski, D.L.; Mruzek, M.T.

    1991-08-27

    Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

  13. Deuterium permeation and retention in copper alloys

    NASA Astrophysics Data System (ADS)

    Zhou, Hai-Shan; Liu, Hao-Dong; An, Zhong-Qing; Li, Bo; Xu, Yu-Ping; Liu, Feng; Zhao, Ming-Zhong; Xu, Qian; Ding, Fang; Luo, Guang-Nan

    2017-09-01

    For plasma-facing components of ITER, tritium (T) transport into the coolant by permeation through CuCrZr heat sink will raise T safety and recovery issues. In the present work, hydrogen isotope permeation and retention in copper (Cu) materials have been experimentally studied. Deuterium (D) gas-driven permeation (GDP) experiments have been performed to evaluate the permeability and diffusion coefficients. Meanwhile, D retention properties in these Cu materials are compared by gas absorption and subsequent thermal desorption spectroscopy (TDS). Finally, low energy (several eV) plasma-driven permeation (PDP) of D through Cu and its alloys has been demonstrated. Significant enhancement in D permeation flux compared with that of GDP has been measured.

  14. Deuterium and hydrogen flows in the thermosphere

    NASA Technical Reports Server (NTRS)

    Breig, E. L.; Hanson, W. B.

    1991-01-01

    Processes that affect vertical distributions and flows of deuterium and hydrogen between 100 and 500 km in the daytime thermosphere are investigated using a steady state numerical model that includes HD and H2 molecular flows, relevant chemistry, and transport by both molecular and eddy diffusion. The results of calculations indicate that the outward thermospheric fuxes and, hence, the planetary loss rates for D must be large compared to evaporative escape (as is also the case for H), confirming the suggestion of Breig et al. (1987). Results of measurements of H in the mesosphere and lower thermosphere and of H and D in the thermosphere were used to derive upward fluxes through the daytime thermosphere, showing that the upward fluxes exceeded the corresponding Jeans evaporative escape rates by factors of about 5 for H, and greater than 500 for D.

  15. Scaled energy (z) distributions of charged hadrons observed in deep-inelastic muon scattering at 490 GeV from xenon and deuterium targets

    NASA Astrophysics Data System (ADS)

    Adams, M. R.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Braun, H. M.; Busza, W.; Carroll, T.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Seyerlein, H. J.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H. J.; Venkataramania, H.; Vidal, M.; Wilhelm, M.; Wilkes, J.; Wilson, Richard; Wittek, W.; Wolbers, S. A.; Zhao, T.

    1994-08-01

    Fermilab Experiment-665 measured deep-inelastic scattering of 490 GeV muons off deuterium and xenon targets. Events were selected with a range of energy exchange ν from 100 GeV to 500 GeV and with large ranges of Q2 and xBj: 0.1 GeV2/c2fractional energy (z) distributions of forward-produced hadrons from the two targets have been compared as a function of the kinematics of the scattering; specifically, the kinematic region of ``shadowing'' has been compared to that of nonshadowing. The dependence of the distributions upon the order of the hadrons, determined by the fractional energies, has been examined as well; a strong degree of similarity has been observed in the shapes of the distributions of the different order hadrons. These z distributions, however, show no nuclear dependence, even in the kinematic region of shadowing.

  16. Real-time prostate motion assessment: image-guidance and the temporal dependence of intra-fraction motion

    PubMed Central

    2013-01-01

    Background The rapid adoption of image-guidance in prostate intensity-modulated radiotherapy (IMRT) results in longer treatment times, which may result in larger intrafraction motion, thereby negating the advantage of image-guidance. This study aims to qualify and quantify the contribution of image-guidance to the temporal dependence of intrafraction motion during prostate IMRT. Methods One-hundred and forty-three patients who underwent conventional IMRT (n=67) or intensity-modulated arc therapy (IMAT/RapidArc, n=76) for localized prostate cancer were evaluated. Intrafraction motion assessment was based on continuous RL (lateral), SI (longitudinal), and AP (vertical) positional detection of electromagnetic transponders at 10 Hz. Daily motion amplitudes were reported as session mean, median, and root-mean-square (RMS) displacements. Temporal effect was evaluated by categorizing treatment sessions into 4 different classes: IMRTc (transponder only localization), IMRTcc (transponder + CBCT localization), IMATc (transponder only localization), or IMATcc (transponder + CBCT localization). Results Mean/median session times were 4.15/3.99 min (IMATc), 12.74/12.19 min (IMATcc), 5.99/5.77 min (IMRTc), and 12.98/12.39 min (IMRTcc), with significant pair-wise difference (p<0.0001) between all category combinations except for IMRTcc vs. IMATcc (p>0.05). Median intrafraction motion difference between CBCT and non-CBCT categories strongly correlated with time for RMS (t-value=17.29; p<0.0001), SI (t-value=−4.25; p<0.0001), and AP (t-value=2.76; p<0.0066), with a weak correlation for RL (t-value=1.67; p=0.0971). Treatment time reduction with non-CBCT treatment categories showed reductions in the observed intrafraction motion: systematic error (Σ)<0.6 mm and random error (σ)<1.2 mm compared with ≤0.8 mm and <1.6 mm, respectively, for CBCT-involved treatment categories. Conclusions For treatment durations >4-6 minutes, and without any intrafraction motion mitigation protocol

  17. Detection of the pedogenic magnetic fraction in volcanic soils developed on basalts using frequency-dependent magnetic susceptibility: comparison of two instruments

    NASA Astrophysics Data System (ADS)

    Grison, Hana; Petrovsky, Eduard; Kapicka, Ales; Hanzlikova, Hana

    2017-01-01

    SUMMARYIn studies of the magnetic properties of soils, the frequency-<span class="hlt">dependent</span> magnetic susceptibility percentage (χFD%) is often used for the identification of ultrafine magnetically superparamagnetic/stable single-domain (SP/SSD) particles. This parameter is commonly used as an indicator for increased pedogenesis. In strongly magnetic soils, the SP/SSD magnetic signal (mostly bio-pedogenic) may be masked by lithological signals; making pedogenesis hard to detect. In this study we compare results for the detection of ultrafine SP/SSD magnetic particles in andic soils using two instruments: a Bartington MS2B dual-frequency meter and an AGICO Kappabridge MFK1-FA. In particular, the study focuses on the effect of pedogenesis by investigating the relationship between specific soil magnetic and chemical properties (soil organic carbon and pHH2O). The values of χFD% obtained with the MS2B varied from 2.4 to 5.9%, and mass-specific magnetic susceptibility (χLF) from 283 to 1688 × 10-8 m3 kg-1, while values of χFD% and χLF obtained with the MFK1-FA varied from 2.7 to 8.2% and from 299 to 1859 × 10-8 m3 kg-1, respectively. Our results suggest that the detection of the SP/SSD magnetic <span class="hlt">fraction</span> can be accomplished by comparing relative trends of χFD% along the soil profile. Moreover, the discrimination between bio-pedogenic and lithogenic magnetic contributions in the SP/SSD <span class="hlt">fraction</span> is possible by comparing the χFD% and χLF data determined in the fine earth (<2 mm) and the coarse <span class="hlt">fraction</span> (4-10 mm) samples down the soil profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.209..654G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.209..654G"><span>Detection of the pedogenic magnetic <span class="hlt">fraction</span> in volcanic soils developed on basalts using frequency-<span class="hlt">dependent</span> magnetic susceptibility: comparison of two instruments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grison, Hana; Petrovsky, Eduard; Kapicka, Ales; Hanzlikova, Hana</p> <p>2017-05-01</p> <p>In studies of the magnetic properties of soils, the frequency-<span class="hlt">dependent</span> magnetic susceptibility percentage (χFD%) is often used for the identification of ultrafine magnetically superparamagnetic/stable single-domain (SP/SSD) particles. This parameter is commonly used as an indicator for increased pedogenesis. In strongly magnetic soils, the SP/SSD magnetic signal (mostly bio-pedogenic) may be masked by lithological signals; making pedogenesis hard to detect. In this study, we compare results for the detection of ultrafine SP/SSD magnetic particles in andic soils using two instruments: a Bartington MS2B dual-frequency meter and an AGICO Kappabridge MFK1-FA. In particular, the study focuses on the effect of pedogenesis by investigating the relationship between specific soil magnetic and chemical properties (soil organic carbon and pHH2O). The values of χFD% obtained with the MS2B varied from 2.4 to 5.9 per cent, and mass-specific magnetic susceptibility (χLF) from 283 to 1688 × 10-8 m3 kg-1, while values of χFD% and χLF obtained with the MFK1-FA varied from 2.7 to 8.2 per cent and from 299 to 1859 × 10-8 m3 kg-1, respectively. Our results suggest that the detection of the SP/SSD magnetic <span class="hlt">fraction</span> can be accomplished by comparing relative trends of χFD% along the soil profile. Moreover, the discrimination between bio-pedogenic and lithogenic magnetic contributions in the SP/SSD <span class="hlt">fraction</span> is possible by comparing the χFD% and χLF data determined in the fine earth (<2 mm) and the coarse <span class="hlt">fraction</span> (4-10 mm) samples down the soil profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70010560','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70010560"><span>The <span class="hlt">deuterium</span> content of water in some volcanic glasses</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Friedman, I.; Smith, R.L.</p> <p>1958-01-01</p> <p>The <span class="hlt">deuterium</span>-hydrogen composition (relative to Lake Michigan water = 0.0) of water extractsd from coexisting perlite and obsidian from eleven different localities was determined. The water content of the obsidians is generally from 0.09 to 0.29 per cent by weight, though two samples from near Olancha, California, contain about 0.92 per cent. The relative <span class="hlt">deuterium</span> concentration is from -4.6 to -12.3 per cent. The coexisting perlite contains from 2.0 to 3.8 per cent of water with a relative <span class="hlt">deuterium</span> concentration of -3.1 to -16.6 per cent. The <span class="hlt">deuterium</span> concentration in the perlites is not related to that in the enclosed obsidian. The <span class="hlt">deuterium</span> concentration in the perlite water is related to the <span class="hlt">deuterium</span> concentration of the modern meteoric water and the perlite water contains approximately 4 per cent less <span class="hlt">deuterium</span> than does the groundwater of the area in which the perlites occur. The above relations hold true for perlites from northern New Mexico, east slope of the Sierra Nevada. California Coast Range, Yellowstone Park, Wyoming, and New Zealand. As the water in the obsidian is unrelated to meteoric water, but the enclosing perlite water is related, we believe that this is evidence for the secondary hydration of obsidian to form high water content perlitic glass. ?? 1958.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18320428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18320428"><span><span class="hlt">Deuterium</span> excess in precipitation of Alpine regions - moisture recycling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Froehlich, Klaus; Kralik, Martin; Papesch, Wolfgang; Rank, Dieter; Scheifinger, Helfried; Stichler, Willibald</p> <p>2008-03-01</p> <p>The paper evaluates long-term seasonal variations of the <span class="hlt">deuterium</span> excess (d-excess = delta(2)H - 8. delta(18)O) in precipitation of stations located north and south of the main ridge of the Austrian Alps. It demonstrates that sub-cloud evaporation during precipitation and continental moisture recycling are local, respectively, regional processes controlling these variations. In general, sub-cloud evaporation decreases and moisture recycling increases the d-excess. Therefore, evaluation of d-excess variations in terms of moisture recycling, the main aim of this paper, includes determination of the effect of sub-cloud evaporation. Since sub-cloud evaporation is governed by saturation deficit and distance between cloud base and the ground, its effect on the d-excess is expected to be lower at mountain than at lowland/valley stations. To determine quantitatively this difference, we examined long-term seasonal d-excess variations measured at three selected mountain and adjoining valley stations. The altitude differences between mountain and valley stations ranged from 470 to 1665 m. Adapting the 'falling water drop' model by Stewart [J. Geophys. Res., 80(9), 1133-1146 (1975).], we estimated that the long-term average of sub-cloud evaporation at the selected mountain stations (altitudes between about 1600 and 2250 m.a.s.l.) is less than 1 % of the precipitation and causes a decrease of the d-excess of less than 2 per thousand. For the selected valley stations, the corresponding evaporated <span class="hlt">fraction</span> is at maximum 7 % and the difference in d-excess ranges up to 8 per thousand. The estimated d-excess differences have been used to correct the measured long-term d-excess values at the selected stations. Finally, the corresponding <span class="hlt">fraction</span> of water vapour has been estimated that recycled by evaporation of surface water including soil water from the ground. For the two mountain stations Patscherkofel and Feuerkogel, which are located north of the main ridge of the Alps, the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.443..275A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.443..275A"><span><span class="hlt">Deuterium</span> chemistry of dense gas in the vicinity of low-mass and massive star-forming regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Awad, Zainab; Viti, Serena; Bayet, Estelle; Caselli, Paola</p> <p>2014-09-01</p> <p>The standard interstellar ratio of <span class="hlt">deuterium</span> to hydrogen (D/H) atoms is ˜1.5 × 10-5. However, the <span class="hlt">deuterium</span> <span class="hlt">fractionation</span> is in fact found to be enhanced, to different degrees, in cold, dark cores, hot cores around massive star-forming regions, lukewarm cores, and warm cores (hereafter hot corinos) around low-mass star-forming regions. In this paper, we investigate the overall differences in the <span class="hlt">deuterium</span> chemistry between hot cores and hot corinos. We have modelled the chemistry of dense gas around low-mass and massive star-forming regions using a gas-grain chemical model. We investigate the influence of varying the core density, the depletion efficiency of gaseous species on to dust grains, the collapse mode and the final mass of the protostar on the chemical evolution of star-forming regions. We find that the <span class="hlt">deuterium</span> chemistry is, in general, most sensitive to variations of the depletion efficiency on to grain surfaces, in agreement with observations. In addition, the results showed that the chemistry is more sensitive to changes in the final density of the collapsing core in hot cores than in hot corinos. Finally, we find that ratios of deuterated sulphur bearing species in dense gas around hot cores and corinos may be good evolutionary indicators in a similar way as their non-deuterated counterparts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5143373','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5143373"><span>Immune-system-<span class="hlt">dependent</span> anti-tumor activity of a plant-derived polyphenol rich <span class="hlt">fraction</span> in a melanoma mouse model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gomez-Cadena, A; Urueña, C; Prieto, K; Martinez-Usatorre, A; Donda, A; Barreto, A; Romero, P; Fiorentino, S</p> <p>2016-01-01</p> <p>Recent findings suggest that part of the anti-tumor effects of several chemotherapeutic agents require an intact immune system. This is in part due to the induction of immunogenic cell death. We have identified a gallotannin-rich <span class="hlt">fraction</span>, obtained from Caesalpinia spinosa (P2Et) as an anti-tumor agent in both breast carcinoma and melanoma. Here, we report that P2Et treatment results in activation of caspase 3 and 9, mobilization of cytochrome c and externalization of annexin V in tumor cells, thus suggesting the induction of apoptosis. This was preceded by the onset of autophagy and the expression of immunogenic cell death markers. We further demonstrate that P2Et-treated tumor cells are highly immunogenic in vaccinated mice and induce immune system activation, clearly shown by the generation of interferon gamma (IFN-γ) producing tyrosine-related protein 2 antigen-specific CD8+ T cells. Moreover, the tumor protective effects of P2Et treatment were abolished in immunodeficient mice, and partially lost after CD4 and CD8 depletion, indicating that P2Et's anti-tumor activity is highly <span class="hlt">dependent</span> on immune system and at least in part of T cells. Altogether, these results support the hypothesis that the gallotannin-rich <span class="hlt">fraction</span> P2Et's anti-tumor effects are mediated to a great extent by the endogenous immune response following to the exposure to immunogenic dying tumor cells. PMID:27253407</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/562572','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/562572"><span>Method for measuring <span class="hlt">deuterium</span> in erbium deuteride films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brangan, J.R.; Thornberg, S.M.; Keenan, M.R.</p> <p>1997-09-01</p> <p>Determining the quantity of <span class="hlt">deuterium</span> in an erbium deuteride (ErD{sub 2}) film is essential for assessing the quality of the hydriding process but is a challenging measurement to make. First, the ideal gas law cannot be applied directly due to high temperature (950{degrees}C) and low temperature (25{degrees}C) regions in the same manifold. Additionally, the metal hydride does not release all of the <span class="hlt">deuterium</span> rapidly upon heating and metal evaporation occurs during extended heating periods. Therefore, the method developed must provide a means to compensate for temperature inhomogeneities and the amount of <span class="hlt">deuterium</span> retained in the metal film while heating for a minimal duration. This paper presents two thermal desorption methods used to evaluate the kinetics and equilibria of the <span class="hlt">deuterium</span> desorption process at high temperatures (950{degrees}C). Of primary concern is the evaluation of the quantity of <span class="hlt">deuterium</span> remaining in these films at the high temperature. A multiple volume expansion technique provided insight into the kinetics of the <span class="hlt">deuterium</span> evolution and metal evaporation from the film. Finally a repeated pump-down approach yielded data that indicated approximately 10% of the <span class="hlt">deuterium</span> is retained in the metal film at 950{degrees}C and approximately 1 Torr pressure. When the total moles of <span class="hlt">deuterium</span> determined by this method were divided by the moles of erbium determined by ICP/AES, nearly stochiometric values of 2:1 were obtained for several erbium dideuteride films. Although this work presents data for erbium and <span class="hlt">deuterium</span>, these methods are applicable to other metal hydrides as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002APS..DPPCO2002M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002APS..DPPCO2002M"><span><span class="hlt">Deuterium</span> Equation-of-State Experiments on Nike</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mostovych, Andrew; Bates, J. W.; Brown, D.; Karasik, M.; Schmitt, A. J.; Weaver, J.; Velikovich, A. L.; Gardner, J. H.</p> <p>2002-11-01</p> <p>Experiments to measure the primary Hugoniot equation of state of <span class="hlt">deuterium</span> in the pressure range of 0.5 to 1.5 Mbar are being conducted on the Nike laser facility. Previous experiments [1,2,3] have yielded conflicting data on the nature of the primary shock Hugoniot and the extent of compressibility of <span class="hlt">deuterium</span> at high pressure. Current experiments are aimed at providing data to help resolve this discrepancy. The experiment uses the Nike laser to drive an aluminum pusher plate into liquid <span class="hlt">deuterium</span> and to launch a steady shock in the <span class="hlt">deuterium</span>. The primary Hugoniot is determined from the particle and shock velocities in the <span class="hlt">deuterium</span> sample. Impedance matching between the releasing aluminum and shocked <span class="hlt">deuterium</span> determines the particle velocity whereas the shock velocity is measured directly. Special targets employ a stepped aluminum pusher to measure the aluminum pressure before release into the <span class="hlt">deuterium</span> and masked witness plates record the time-of-flight velocity of the <span class="hlt">deuterium</span> shocks as they travel from the pusher to the witness plate. Data are analyzed assuming that the aluminum release curves are well represented by the SESAME EOS. In the range of 0.5-0.75 Mbar, initial data show higher compressibility in <span class="hlt">deuterium</span> than is predicted by SESAME but relatively good agreement at higher pressures. 1. L.B. DaSilva et al., Phys. Rev. Lett. 78, 483 (1997). 2. A.N. Mostovych et al., Phys. Rev. Lett. 85, 3870 (2000). 3. M. D. Knudson, et al., Phys. Rev. Lett. 87, 225501-1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5103195','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5103195"><span>Fucose-containing <span class="hlt">fraction</span> of Ling-Zhi enhances lipid rafts-<span class="hlt">dependent</span> ubiquitination of TGFβ receptor degradation and attenuates breast cancer tumorigenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tsao, Shu-Ming; Hsu, Hsien-Yeh</p> <p>2016-01-01</p> <p>Ganoderma lucidum exerts antitumor activity, but the mechanism of G. lucidum polysaccharides on cancer is unclear. Here, we demonstrated that a fucose-containing <span class="hlt">fraction</span> of Ling-Zhi (FFLZ) reduced tumor size and suppressed metastasis in vivo. Furthermore, FFLZ inhibited breast cancer cell migration and altered the epithelial-to-mesenchymal transition (EMT) phenotype. Transforming growth factor-β receptor (TGFR) pathways act as key mediators to promote tumor progression and metastasis. We found that FFLZ down-regulated TGFR and downstream signaling pathways, including the phosphorylation of Smad2/3 and the expression of Smad4. In an investigation of the underlying mechanisms, we found that FFLZ enhanced the Smurf2-<span class="hlt">dependent</span> ubiquitination of TGFR by disrupting the balance of the lipid rafts, promoted the “re-localization” of the TGFR to the caveolae, and facilitated the degradation of TGFR. Together, our data indicated that FFLZ is associated with the inhibition of EMT and the prevention of metastasis by promoting ubiquitination-<span class="hlt">dependent</span> TGFR degradation and abolishing TGFR signaling pathways. Moreover, the combination of FFLZ and trastuzumab synergistically inhibited the viability of certain trastuzumab-resistant human breast cancer cells. In summary, our current findings indicate that FFLZ is a potential therapeutic or dietary supplemental agent for cancer patients and that it functions via the caveolin-1/Smad7/Smurf2-<span class="hlt">dependent</span> ubiquitin-mediated degradation of TGFR. PMID:27830743</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5216155','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5216155"><span><span class="hlt">Dependence</span> on solar elevation and the daily sunshine <span class="hlt">fraction</span> of the correlation between monthly-average-hourly diffuse and global radiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Soler, A. )</p> <p>1992-01-01</p> <p>In the present work the authors study for Uccle, Belgium data (50{degree}48 minutes N, 4{degree}21 minutes E), the <span class="hlt">dependence</span> on {anti {gamma}} and {sigma} of the correlations between {anti K}{sub d} = {anti I}{sub d}/{anti I}{sub o} and {anti I}{sub t} = {anti I}/{anti I}{sub o}, where {anti I}, {anti I}{sub d}, and {anti I}{sub o} are respectively, the monthly-average-hourly value of global, diffuse, and extraterrestrial radiation (all of them on a horizontal surface), {anti {gamma}} is the solar elevation at midhour and {sigma} the daily sunshine <span class="hlt">fraction</span>. The <span class="hlt">dependence</span> on {sigma} is studied for different ranges of values, from {sigma} = 0 to {sigma} > 0.9. The <span class="hlt">dependence</span> on {anti {gamma}} is studied for {anti {gamma}} = 5{degree}, 10{degree}, 15{degree}, 25{degree}-30{degree}; 35{degree}-40{degree}; 45{degree}-60{degree} ({delta}{anti {gamma}} = 5{degree}). Relating the <span class="hlt">dependence</span> on {sigma}, for increasing values of {sigma}({sigma} {>=} 0), there is an increase in {anti K}{sub d} with the increase in {anti K}{sub t}. For 0.42 < {anti K}{sub t} < 0.52 a maximum is obtained for {anti K}{sub d}. After the maximum, as the skies become clearer, {anti K}{sub d} decreases as {anti K}{sub t} increases. Relating the <span class="hlt">dependence</span> on {anti {gamma}}, for each range of values of {sigma} ({sigma} > 0.2), values of the slope for linear {anti K}{sub d} = f({anti K}{sub t}) correlations show a tendency to decrease as {anti {gamma}} increases. For each value of {anti {gamma}} the slopes of the linear {anti K}{sub d} = f({anti K}{sub t}) correlations tend to decrease when {sigma} increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..96c2005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..96c2005S"><span>Invariant-mass and <span class="hlt">fractional</span>-energy <span class="hlt">dependence</span> of inclusive production of dihadrons in e+e- annihilation at √{s }=10.58 GeV</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seidl, R.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aushev, T.; Ayad, R.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Behera, P.; Bhardwaj, V.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, S.-K.; Choi, Y.; Cinabro, D.; Dash, N.; Di Carlo, S.; Doležal, Z.; Drásal, Z.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goldenzweig, P.; Guido, E.; Haba, J.; Hayasaka, K.; Hayashii, H.; Hou, W.-S.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwasaki, Y.; Jacobs, W. W.; Jaegle, I.; Jeon, H. B.; Jia, S.; Jin, Y.; Joffe, D.; Joo, K. K.; Julius, T.; Kang, K. H.; Karyan, G.; Kim, D. Y.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Krokovny, P.; Kulasiri, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Li, L.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lubej, M.; Luo, T.; Masuda, M.; Matsuda, T.; Matvienko, D.; Merola, M.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Nath, K. J.; Natkaniec, Z.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Ono, H.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Pardi, S.; Park, H.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Pulvermacher, C.; Ritter, M.; Rostomyan, A.; Sakai, Y.; Santelj, L.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Sokolov, A.; Solovieva, E.; Starič, M.; Strube, J. F.; Sumisawa, K.; Sumiyoshi, T.; Takizawa, M.; Tamponi, U.; Tanida, K.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Varner, G.; Vorobyev, V.; Vossen, A.; Wang, C. H.; Wang, P.; Watanabe, M.; Watanabe, Y.; Watanuki, S.; Widmann, E.; Won, E.; Yamashita, Y.; Ye, H.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration</p> <p>2017-08-01</p> <p>The inclusive cross sections for dihadrons of charged pions and kaons (e+e-→h h X ) in electron-positron annihilation are reported. They are obtained as a function of the total <span class="hlt">fractional</span> energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere dihadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-<span class="hlt">dependent</span> measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655 fb-1 data sample collected at or near the ϒ (4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850034841&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddeuterium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850034841&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddeuterium"><span>Observations of interstellar hydrogen and <span class="hlt">deuterium</span> toward Alpha Centauri A</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Landsman, W. B.; Henry, R. C.; Moos, H. W.; Linsky, J. L.</p> <p>1984-01-01</p> <p>A composite profile is presented of the Ly-alpha emission line of Alpha Cen A, obtained from 10 individual spectra with the high-resolution spectrograph aboard the International Ultraviolet Explorer (IUE) satellite. There is excellent overall agreement with two previous Copernicus observations. Interstellar <span class="hlt">deuterium</span> is detected, and a lower limit is set on the <span class="hlt">deuterium</span> to hydrogen ratio of nDI/nHI greater than 8 x 10 to the -6th. In addition, the <span class="hlt">deuterium</span> bulk velocity appears blueshifted by 8 + or - 2 km/s with respect to interstellar hydrogen, suggesting a nonuniform medium along the line of sight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=246192','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=246192"><span>Oxidation of C1 Compounds by Particulate <span class="hlt">fractions</span> from Methylococcus capsulatus: distribution and properties of methane-<span class="hlt">dependent</span> reduced nicotinamide adenine dinucleotide oxidase (methane hydroxylase).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ribbons, D W</p> <p>1975-01-01</p> <p>Cell-free particulate <span class="hlt">fractions</span> of extracts from the obligate methylotroph Methylococcus capsulatus catalyze the reduced nicotinamide adenine dinucleotide (NADH) and O2-<span class="hlt">dependent</span> oxidation of methane (methane hydroxylase). The only oxidation product detected was formate. These preparations also catalyze the oxidation of methanol and formaldehyde to formate in the presence or absence of phenazine methosulphate with oxygen as the terminal electron acceptor. Methane hydroxylase activity cannot be reproducibly obtained from disintegrated cell suspensions even though the whole cells actively respired when methane was presented as a substrate. Varying the disintegration method or extraction medium had no significant effect on the activities obtained. When active particles were obtained, hydroxylase activity was stable at 0 C for days. Methane hydroxylase assays were made by measuring the methane-<span class="hlt">dependent</span> oxidation of NADH by O2. In separate experiments, methane consumption and the accumulation of formate were also demonstrated. Formate is not oxidized by these particulate <span class="hlt">fractions</span>. The effects of particle concentration, temperature, pH, and phosphate concentration on enzymic activity are described. Ethane is utilized in the presence of NADH and O2. The stoichiometric relationships of the reaction(s) with methane as substrate were not established since (i) the presumed initial product, methanol, is also oxidized to formate, and (ii) the contribution that NADH oxidase activity makes to the observed consumption of reactants could not be assessed in the presence of methane. Studies with known inhibitors of electron transport systems indicate that the path of electron flow from NADH to oxygen is different for the NADH oxidase, methane hydroxylase, and methanol oxidase activities. Images PMID:238946</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25564955','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25564955"><span>Identical Hg isotope mass <span class="hlt">dependent</span> <span class="hlt">fractionation</span> signature during methylation by sulfate-reducing bacteria in sulfate and sulfate-free environment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Perrot, Vincent; Bridou, Romain; Pedrero, Zoyne; Guyoneaud, Remy; Monperrus, Mathilde; Amouroux, David</p> <p>2015-02-03</p> <p>Inorganic mercury (iHg) methylation in aquatic environments is the first step leading to monomethylmercury (MMHg) bioaccumulation in food webs and might play a role in the Hg isotopic composition measured in sediments and organisms. Methylation by sulfate reducing bacteria (SRB) under sulfate-reducing conditions is probably one of the most important sources of MMHg in natural aquatic environments, but its influence on natural Hg isotopic composition remains to be ascertained. In this context, the methylating SRB Desulfovibrio dechloracetivorans (strain BerOc1) was incubated under sulfate reducing and fumarate respiration conditions (SR and FR, respectively) to determine Hg species specific (MMHg and IHg) isotopic composition associated with methylation and demethylation kinetics. Our results clearly establish Hg isotope mass-<span class="hlt">dependent</span> <span class="hlt">fractionation</span> (MDF) during biotic methylation (-1.20 to +0.58‰ for δ(202)Hg), but insignificant mass-independent <span class="hlt">fractionation</span> (MIF) (-0.12 to +0.15‰ for Δ(201)Hg). During the 24h of the time-course experiments Hg isotopic composition in the produced MMHg becomes significantly lighter than the residual IHg after 1.5h and shows similar δ(202)Hg values under both FR and SR conditions at the end of the experiments. This suggests a unique pathway responsible for the MDF of Hg isotopes during methylation by this strain regardless the metabolism of the cells. After 9 h of experiment, significant simultaneous demethylation is occurring in the culture and demethylates preferentially the lighter Hg isotopes of MMHg. Therefore, <span class="hlt">depending</span> on their methylation/demethylation capacities, SRB communities in natural sulfate reducing conditions likely have a significant and specific influence on the Hg isotope composition of MMHg (MDF) in sediments and aquatic organisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhRvD..76g2004D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhRvD..76g2004D"><span>Measurement of branching <span class="hlt">fraction</span> and time-<span class="hlt">dependent</span> CP asymmetry parameters in B0→D*+D*-KS0 decays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dalseno, J.; Adachi, I.; Aihara, H.; Aushev, T.; Bakich, A. M.; Balagura, V.; Bay, A.; Bitenc, U.; Bizjak, I.; Bozek, A.; Bračko, M.; Browder, T. E.; Chao, Y.; Chen, A.; Cheon, B. G.; Chistov, R.; Cho, I.-S.; Choi, Y.; Choi, Y. K.; Danilov, M.; Dash, M.; Drutskoy, A.; Eidelman, S.; Go, A.; Ha, H.; Hayasaka, K.; Hazumi, M.; Heffernan, D.; Hokuue, T.; Hyun, H. J.; Inami, K.; Ishikawa, A.; Ishino, H.; Iwasaki, M.; Iwasaki, Y.; Joshi, N. J.; Kah, D. H.; Kang, J. H.; Kapusta, P.; Katayama, N.; Kawai, H.; Kawasaki, T.; Kichimi, H.; Kim, H. J.; Kim, Y. J.; Kinoshita, K.; Križan, P.; Krokovny, P.; Kumar, R.; Kuo, C. C.; Kuzmin, A.; Kwon, Y.-J.; Lee, J. S.; Lee, S. E.; Lesiak, T.; Li, J.; Limosani, A.; Lin, S.-W.; Liventsev, D.; Mandl, F.; Matsumoto, T.; McOnie, S.; Medvedeva, T.; Mitaroff, W.; Miyake, H.; Miyata, H.; Moloney, G. R.; Nakano, E.; Nakao, M.; Nishida, S.; Nitoh, O.; Ogawa, S.; Ohshima, T.; Okuno, S.; Onuki, Y.; Ostrowicz, W.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, K. S.; Pestotnik, R.; Piilonen, L. E.; Sahoo, H.; Sakai, Y.; Schneider, O.; Schümann, J.; Seidl, R.; Sekiya, A.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shibuya, H.; Singh, J. B.; Sokolov, A.; Somov, A.; Stanič, S.; Starič, M.; Stoeck, H.; Sumisawa, K.; Sumiyoshi, T.; Takasaki, F.; Tanaka, M.; Taylor, G. N.; Teramoto, Y.; Tian, X. C.; Tsukamoto, T.; Uehara, S.; Ueno, K.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Varner, G.; Villa, S.; Vinokurova, A.; Wang, C. C.; Wang, C. H.; Watanabe, Y.; Wedd, R.; Won, E.; Yabsley, B. D.; Yamaguchi, A.; Yamashita, Y.; Yamauchi, M.; Zhang, Z. P.; Zhilich, V.; Zupanc, A.</p> <p>2007-10-01</p> <p>We present a measurement of the branching <span class="hlt">fraction</span> and time-<span class="hlt">dependent</span> CP violation parameters for B0→D*+D*-KS0 decays. These results are obtained from a 414fb-1 data sample that contains 449×106 BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the branching <span class="hlt">fraction</span>, B(B0→D*+D*-KS0)=[3.4±0.4(stat)±0.7(syst)]×10-3, which is in agreement with the current world average. We also obtain an upper limit on the product branching <span class="hlt">fraction</span> for a possible two-body decay, B(B0→Ds1+(2536)D*-)B(Ds1+(2536)→D*+KS0)<7.1×10-4 (90% CL). In the traditional 2-parameter time-<span class="hlt">dependent</span> CP analysis, we measure the CP violation parameters, ACP=-0.01-0.28+0.28(stat)±0.09(syst), Dsin⁡2ϕ1=0.06-0.44+0.45(stat)±0.06(syst). No evidence for either mixing-induced or direct CP violation is found. In a 3-parameter fit sensitive to cos⁡2ϕ1 performed in the half-Dalitz spaces, s-≤s+ and s->s+, where s±≡m2(D*±KS0), we extract the CP violation parameters, Jc/J0=0.60-0.28+0.25(stat)±0.08(syst), 2Js1/J0sin⁡2ϕ1=-0.17-0.42+0.42(stat)±0.09(syst), 2Js2/J0cos⁡2ϕ1=-0.23-0.41+0.43(stat)±0.13(syst). A large value of Jc/J0 would indicate a significant resonant contribution from a broad unknown Ds**+ state. Although the sign of the factor, 2Js2/J0, can be deduced from theory, no conclusion can be drawn regarding the sign of cos⁡2ϕ1 given the errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/426224','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/426224"><span>Computer experiments concerning palladium-<span class="hlt">deuterium</span> and titanium-<span class="hlt">deuterium</span> lattices - implications to phenomenon of low-energy nuclear reaction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rao, K.R.; Chaplot, S.L.</p> <p>1996-12-01</p> <p>Short-lived large energy fluctuations (SLEFs) in solids, proposed by Khait, are known to be responsible for several anomalous properties in a variety of materials. The study of SLEFs in palladium-<span class="hlt">deuterium</span> and titanium-<span class="hlt">deuterium</span> lattices via computer experiments is reported. The relevance of these large energy fluctuations in penetrating coulombic barriers in these systems is discussed. Such dynamical effects arising from the phonon bath in solids may enhance nuclear reaction probabilities leading to cold fusion. Expected cold fusion reaction rates are reported taking into account the effective charges of the <span class="hlt">deuterium</span> atoms in the solid and SLEF frequencies. 25 refs., 7 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993Metic..28Q.385L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993Metic..28Q.385L"><span>Influence of Murchison Minerals on Hydrogen-<span class="hlt">Deuterium</span> Exchange of Amino Acids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lerner, N. R.</p> <p>1993-07-01</p> <p>The amino acids found on the Murchison meteorite are <span class="hlt">deuterium</span> enriched. For the glycine-alanine <span class="hlt">fraction</span>, delta D = +2448 per mil, and for the alpha-amino isobutyric acid <span class="hlt">fraction</span>, delta D = +149 per mil [1]. In order to retain such levels of <span class="hlt">deuterium</span> enrichment, the amino acids found in Murchison must have not only retained the <span class="hlt">deuterium</span> enrichment of their interstellar precursors (delta D > +1500 per mil [2]) during synthesis, as has been recently shown [3], but they must have also retained their <span class="hlt">deuterium</span> label during the aqueous alteration phase [4]. By measuring the rates of <span class="hlt">deuterium</span> exchange of amino acids with D(sub)2O, limits can be set on the length of time and the conditions under which the Murchison parent body experienced an aqueous environment. The rates of hydrogen-<span class="hlt">deuterium</span> exchange of nondeuterated glycine, alanine, alpha-amino isobutyric acid, and amino diacetic acid have been measured in D(sub)2O as a function of temperature, pH, and the presence of Murchison minerals. In addition to the amino and carboxylic hydrogens, only the alpha- hydrogens of glycine, alanine, and amino diacetic acid are found to exchange. Even for solutions maintained for weeks at temperatures as high as 120 degrees C, no exchange was observed with the hydrogens of the methyl groups of alanine or alpha-amino isobutyric acid. The rate of exchange for alpha-hydrogens of amino acids is first-order with respect to the amino acid concentration. Increasing the pH of the solution markedly increases the rate of exchange. For example, at 115 degrees C and pH 4.0, 7.0, and 10 the rates are 14, 30, and 125 yr^-1 respectively for glycine and 2.0, 3.5, and 14 yr^-1 respectively for alanine. In a pH-6.0 D(sub)2O solution of amino acids containing Murchison dust the rates are 135 yr^-1 for glycine and 32 yr^-1 for alanine, rates close to those for the pH 10 solution. Activation energies for exchange were obtained from Arrhenius plots constructed from measurements made between 70 degrees</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19670000304','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19670000304"><span>Cytology is advanced by studying effects of <span class="hlt">deuterium</span> environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bose, S.; Crespi, H. L.; Flaumenhaft, E.; Katz, J. J.</p> <p>1967-01-01</p> <p>Research of <span class="hlt">deuterium</span> effects on biological systems shows deuteriation is not incompatible with life. With the successful cultivation of deuteriated bacteria, work is now being done on extraction of deuterio-compounds from bacteria.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22252188','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22252188"><span>Laser induced neutron production by explosion of the <span class="hlt">deuterium</span> clusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Holkundkar, Amol R.; Mishra, Gaurav Gupta, N. K.</p> <p>2014-01-15</p> <p>The high energy <span class="hlt">deuterium</span> ions serve as compact source of neutrons when fused with either <span class="hlt">deuterium</span> or tritium atoms. In view of this, the explosion of the <span class="hlt">deuterium</span> clusters under the influence of the laser pulse with intensity ranging from 10{sup 15} to 10{sup 19} W/cm{sup 2} is being studied along with the effect of the cluster radius and inter-cluster distance. The objective of this article is to study the efficiency of the <span class="hlt">deuterium</span> cluster as a compact source of neutrons under various laser and cluster parameters. It is being observed that the cluster density (number of clusters per unit volume) is quite important to gain high neutron yield.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5200425','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5200425"><span>Infrared presensitization photography at <span class="hlt">deuterium</span> fluoride laser wavelengths</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Geary, J.M.; Ross, K.; Suter, K. )</p> <p>1989-09-01</p> <p>Near-field irradiance distributions of a <span class="hlt">deuterium</span> flouride laser system are obtained using infrared presensitization photography. This represents the shortest wavelength region to employ this technique thus far.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JNuM..415S.713P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JNuM..415S.713P"><span>Influence of beryllium carbide formation on <span class="hlt">deuterium</span> retention and release</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Porosnicu, C.; Anghel, A.; Sugiyama, K.; Krieger, K.; Roth, J.; Lungu, C. P.</p> <p>2011-08-01</p> <p>The inconel cladding tiles of the ITER-like-wall to be tested at JET will be coated by a beryllium layer. Carbon containing tiles will be also present. These materials are sputtered in the high flux (1022 m-2 s-1 or higher) of the <span class="hlt">deuterium</span>-tritium plasma. Ionized by the energetic electrons and with hydrogen isotope ions they will be implanted or re-deposited, creating composite layers.In order to study the <span class="hlt">deuterium</span> retention and release, mixed layers were prepared using the thermionic arc method.<span class="hlt">Deuterium</span> implantation was performed using a high current ion source at room temperature using a <span class="hlt">deuterium</span> ion beam with energy of 200 eV/D. Thermal Desorption Spectroscopy (TDS) analyses were correlated with the beryllium/carbon relative concentrations of the prepared films. At higher carbon concentrations the peak value from TDS spectra corresponding to beryllium was lower and an increased peak corresponding to the carbon was observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.P33A1741E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.P33A1741E"><span><span class="hlt">Deuterium</span> in astrophysical ice analogues: Isotope exchange and IR detection sensitivity for HDO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Escribano, R. M.; Galvez, O.; Mate, B.; Herrero, V. J.</p> <p>2011-12-01</p> <p>Among D-bearing molecules, water is especially interesting from an astrophysical point of view. Although the <span class="hlt">deuterium</span> content of water in astronomical environments is relatively small as compared with other molecules, it holds most valuable information, still largely undeciphered, on the dynamics of formation and evaporation of ice grain mantels in protostellar regions [1], and is crucial for the understanding of the formation of the Solar System and the Earth [2]. In this work, we have used the OD stretching bands of HDO and D2O molecules in various ice mixtures formed by vapor deposition on a cold substrate (see ref [3] for a description of the experimental set-up) to study the sensitivity of the IR technique for the detection of HDO in ice samples, and to monitor processes of H/D isotope exchange in these solids. It is found that the detection sensitivity is strongly <span class="hlt">dependent</span> on the ice structure. The OD band is extremely broad and tends to disappear into the absorption continuum of H2O for low temperature amorphous samples. Detectable HDO/H2O ratios with this technique may range from a few per cent for amorphous samples to a few per thousand in crystalline ice. These relatively high upper limits and the appreciable <span class="hlt">dependence</span> of the band shape on temperature, complicating the interpretation of data from many lines of sight, may question the usefulness of this technique. Isotopic H/D exchange in mixed ices of H2O/D2O is found to start at ~ 120 K and is greatly accelerated at 150 K, as crystallization proceeds in the ice. The process is mainly driven by proton transfer assisted by orientational defect mobility. Annealed amorphous samples are more favourable for isotope exchange than samples directly formed in the crystalline phase. The annealing process seems to lead to polycrystalline ice morphology with a higher defect activity. The present data emphasize the relevance of a depletion mechanism for D atoms in hydroxylic bonds in the solid state, recently</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26852022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26852022"><span>Combinatorial synthesis of <span class="hlt">deuterium</span>-enriched (S)-oxybutynin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Feng; Jiang, Wenfeng; Czarnik, Anthony W; Li, Wenbao</p> <p>2016-08-01</p> <p>The concept of <span class="hlt">deuterium</span> enrichment has gained more attention due to its advantages in the studies of clinical pharmacokinetics and metabolic profiles. In addition, it is cost and time efficient to develop <span class="hlt">deuterium</span>-enriched drugs. Herein we built a combinatorial library of deuterated (S)-oxybutynins which all 8 D-compounds were characterized by MS, [Formula: see text] NMR and [Formula: see text]C NMR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993NIMPB..79..487H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993NIMPB..79..487H"><span>Depth profiling of <span class="hlt">deuterium</span> using nuclear reaction analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, I. G.; Behrisch, R.; Martinelli, A. P.</p> <p>1993-06-01</p> <p>We report on a method to measure the depth profile of <span class="hlt">deuterium</span> up to a depth of 7 μm in a carbon/beryllium layer using the D( 3He, p) 4He nuclear reaction in a resonance-like technique. The <span class="hlt">deuterium</span> depth profile is determined from a measurement of the proton yield as a function of incident 3He ion energy for a limiter tile from the Joint European Torus (JET) tokamak.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992NIMPB..64..434H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992NIMPB..64..434H"><span>Depth profiling of <span class="hlt">deuterium</span> in a beryllium/carbon layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, I. G.; Behrisch, R.; Martinelli, A. P.</p> <p>1992-02-01</p> <p>Depth distributions for <span class="hlt">deuterium</span> trapped within the Be/C layer on a JET limiter after long-term operation have been measured up to a depth of 7 μm using the D( 3He, p) 4He reaction in a resonance-like technique. For several points along a JET limiter tile, depth profiles and the total amount of trapped <span class="hlt">deuterium</span> have been determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PMB....50.2127M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PMB....50.2127M"><span>Pharmaco-thermodynamics of <span class="hlt">deuterium</span>-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medina, Daniel C.; Li, Xin; Springer, Charles S., Jr.</p> <p>2005-05-01</p> <p>In addition to its common usage as a tracer in metabolic and physiological studies, <span class="hlt">deuterium</span> possesses anti-tumoural activity and confers protection against γ-irradiation. A more recent interest in <span class="hlt">deuterium</span> emanates from the search for alternatives capable of improving neutron penetrance whilst reducing healthy tissue radiation dose deposition in boron neutron capture therapy of malignant brain tumours. Despite this potential clinical application, <span class="hlt">deuterium</span> induces brain oedema, which is detrimental to neutron capture therapy. In this study, five adult male rats were titrated with deuterated drinking water while brain oedema was monitored via water proton magnetic resonance imaging. This report concludes that <span class="hlt">deuterium</span>, as well as <span class="hlt">deuterium</span>-induced brain oedema, possesses a uniform brain bio-distribution. At a steady-state blood fluid deuteration value of 16%, when the <span class="hlt">deuterium</span> isotope <span class="hlt">fraction</span> in drinking water was 25%, a mean oedematous volume change of 9 ± 2% (p-value <0.001) was observed in the rat brain—this may account for neurological and behavioural abnormalities found in mammals drinking highly deuterated water. In addition to characterizing the pharmaco-thermodynamics of <span class="hlt">deuterium</span>-induced oedema, this report also estimates the impact of oedema on thermal neutron enhancement and effective dose reduction factors using simple linear transport calculations. While body fluid deuteration enhances thermal neutron flux penetrance and reduces dose deposition, oedema has the opposite effect because it increases the volume of interest, e.g., the brain volume. Thermal neutron enhancement and effective dose reduction factors could be reduced by as much as ~10% in the presence of a 9% water volume increase (oedema). All three authors have contributed equally to this work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15843741','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15843741"><span>Pharmaco-thermodynamics of <span class="hlt">deuterium</span>-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Medina, Daniel C; Li, Xin; Springer, Charles S</p> <p>2005-05-07</p> <p>In addition to its common usage as a tracer in metabolic and physiological studies, <span class="hlt">deuterium</span> possesses anti-tumoural activity and confers protection against gamma-irradiation. A more recent interest in <span class="hlt">deuterium</span> emanates from the search for alternatives capable of improving neutron penetrance whilst reducing healthy tissue radiation dose deposition in boron neutron capture therapy of malignant brain tumours. Despite this potential clinical application, <span class="hlt">deuterium</span> induces brain oedema, which is detrimental to neutron capture therapy. In this study, five adult male rats were titrated with deuterated drinking water while brain oedema was monitored via water proton magnetic resonance imaging. This report concludes that <span class="hlt">deuterium</span>, as well as <span class="hlt">deuterium</span>-induced brain oedema, possesses a uniform brain bio-distribution. At a steady-state blood fluid deuteration value of 16%, when the <span class="hlt">deuterium</span> isotope <span class="hlt">fraction</span> in drinking water was 25%, a mean oedematous volume change of 9 +/- 2% (p-value <0.001) was observed in the rat brain-this may account for neurological and behavioural abnormalities found in mammals drinking highly deuterated water. In addition to characterizing the pharmaco-thermodynamics of <span class="hlt">deuterium</span>-induced oedema, this report also estimates the impact of oedema on thermal neutron enhancement and effective dose reduction factors using simple linear transport calculations. While body fluid deuteration enhances thermal neutron flux penetrance and reduces dose deposition, oedema has the opposite effect because it increases the volume of interest, e.g., the brain volume. Thermal neutron enhancement and effective dose reduction factors could be reduced by as much as approximately 10% in the presence of a 9% water volume increase (oedema).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24038445','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24038445"><span>Four-bond <span class="hlt">deuterium</span> isotope effects on the chemical shifts of amide nitrogens in proteins.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tugarinov, Vitali</p> <p>2013-11-01</p> <p>An approach towards precision NMR measurements of four-bond <span class="hlt">deuterium</span> isotope effects on the chemical shifts of backbone amide nitrogen nuclei in proteins is described. Three types of four-bond (15) N <span class="hlt">deuterium</span> isotope effects are distinguished <span class="hlt">depending</span> on the site of proton-to-<span class="hlt">deuterium</span> substitution: (4)ΔN(N(i-1)D), (4)ΔN(N(i+1)D) and (4)ΔN(Cβ,(i-1)D). All the three types of isotope shifts are quantified in the (partially) deuterated protein ubiquitin. The (4)ΔN(N(i+1)D) and (4)ΔN(C(β,i-1)D) effects are by far the largest in magnitude and vary between 16 and 75 ppb and -18 and 46 ppb, respectively. A semi-quantitative correlation between experimental (4)ΔN(N(i+1)D) and (4)ΔN(C(β,i-1)D) values and the distances between nitrogen nuclei and the sites of (1)H-to-D substitution is noted. The largest isotope shifts in both cases correspond to the shortest inter-nuclear distances. Copyright © 2013 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MRE.....2g6101M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MRE.....2g6101M"><span><span class="hlt">Deuterium</span> ordering found in new ferroelectric compound Co2(OD)3Cl</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meng, Dong-Dong; Zheng, Xu-Guang; Liu, Xiao-Dong; Xu, Xing-Liang; Guo, Qi-Xin</p> <p>2015-07-01</p> <p>A detailed temperature-<span class="hlt">dependent</span> Raman spectroscopic study revealed a new type of <span class="hlt">deuterium</span>-order ferroelectrics in a geometrically frustrated magnet Co2(OD)3Cl at Tɛ = 229 K. Significant changes in the parameters of the Raman vibration modes were observed near Tɛ, suggesting a strong phonon-charge coupling. Additional asymmetric phonon bands appeared below around Tɛ, which are consistently interpreted by phonon folding processes due to a small local structural change resulting from the ordering of <span class="hlt">deuterium</span>. The wavenumber and intensity changes of the Raman-active modes, as well as the normalized intensities of the additional bands, all follow a power-law fit Δω, ΔI, I ∝ (1 - T/TC)2β, wherein TC = 230 K ˜ Tɛ and β = 0.35(2), clearly demonstrating an ordering process below Tɛ. The critical exponent is reminiscent of a second order transition. Our study presents a rare and new type of multiferroic material with ferroelectricity arising from the <span class="hlt">deuterium</span> ordering in geometrically frustrated magnets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhLA..374.2766W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhLA..374.2766W"><span>Ultra-dense <span class="hlt">deuterium</span> and cold fusion claims</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winterberg, F.</p> <p>2010-06-01</p> <p>An attempt is made to explain the recently reported occurrence of 14 MeV neutron induced nuclear reactions in <span class="hlt">deuterium</span> metal hydrides as the manifestation of a slightly radioactive ultra-dense form of <span class="hlt">deuterium</span>, with a density of 130,000 g/cm 3 observed by a Swedish research group through the collapse of <span class="hlt">deuterium</span> Rydberg matter. In accordance with this observation it is proposed that a large number of deuterons form a “linear-atom” supermolecule. By the Madelung transformation of the Schrödinger equation, the linear <span class="hlt">deuterium</span> supermolecule can be described by a quantized line vortex. A vortex lattice made up of many such supermolecules is possible only with <span class="hlt">deuterium</span>, because deuterons are bosons, and the same is true for the electrons, which by the electron-phonon interaction in a vortex lattice form Cooper pairs. It is conjectured that the latent heat released by the collapse into the ultra-dense state has been misinterpreted as cold fusion. Hot fusion though, is here possible through the fast ignition of a thermonuclear detonation wave from a hot spot made with a 1 kJ 10 petawatt laser in a thin slice of the ultra-dense <span class="hlt">deuterium</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1347567-first-measurements-deuterium-tritium-deuterium-deuterium-fusion-reaction-yields-ignition-scalable-direct-drive-implosions','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1347567-first-measurements-deuterium-tritium-deuterium-deuterium-fusion-reaction-yields-ignition-scalable-direct-drive-implosions"><span>First measurements of <span class="hlt">deuterium</span>-tritium and <span class="hlt">deuterium-deuterium</span> fusion reaction yields in ignition-scalable direct-drive implosions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Forrest, C. J.; Radha, P. B.; Knauer, J. P.; ...</p> <p>2017-03-03</p> <p>In this study, the <span class="hlt">deuterium</span>-tritium (D-T) and <span class="hlt">deuterium-deuterium</span> neutron yield ratio in cryogenic inertial confinement fusion (ICF) experiments is used to examine multifluid effects, traditionally not included in ICF modeling. This ratio has been measured for ignition-scalable direct-drive cryogenic DT implosions at the Omega Laser Facility using a high-dynamic-range neutron time-of-flight spectrometer. The experimentally inferred yield ratio is consistent with both the calculated values of the nuclear reaction rates and the measured preshot target-fuel composition. These observations indicate that the physical mechanisms that have been proposed to alter the fuel composition, such as species separation of the hydrogen isotopes, aremore » not significant during the period of peak neutron production in ignition-scalable cryogenic direct-drive DT implosions.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25722428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25722428"><span>Systemically delivered adipose stromal vascular <span class="hlt">fraction</span> cells disseminate to peripheral artery walls and reduce vasomotor tone through a CD11b+ cell-<span class="hlt">dependent</span> mechanism.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morris, Marvin E; Beare, Jason E; Reed, Robert M; Dale, Jacob R; LeBlanc, Amanda J; Kaufman, Christina L; Zheng, Huaiyu; Ng, Chin K; Williams, Stuart K; Hoying, James B</p> <p>2015-04-01</p> <p>Vasoactivity, an important aspect of tissue healing, is often compromised in disease and tissue injury. Dysfunction in the smaller vasoactive arteries is most impactful, given the role of these vessels in controlling downstream tissue perfusion. The adipose stromal vascular <span class="hlt">fraction</span> (SVF) is a mix of homeostatic cells shown to promote tissue healing. Our objective was to test the hypothesis that autologous SVF cells therapeutically modulate peripheral artery vasoactivity in syngeneic mouse models of small artery function. Analysis of vasoactivity of saphenous arteries isolated from normal mice 1 week after intravenous injection of freshly isolated SVF cells revealed that pressure-<span class="hlt">dependent</span> artery vasomotor tone was decreased by the SVF cell isolate, but not one depleted of CD11b(+) cells. Scavenging hydrogen peroxide in the vessel wall abrogated the artery relaxation promoted by the SVF cell isolate. Consistent with a CD11b(+) cell being the relevant cell type, SVF-derived F4/80-positive macrophages were present within the adventitia of the artery wall coincident with vasorelaxation. In a model of artery inflammation mimicking a common disease condition inducing vasoactive dysfunction, the SVF cells potentiated relaxation of saphenous arteries without structurally remodeling the artery via a CD11b(+) cell-<span class="hlt">dependent</span> manner. Our findings demonstrate that freshly isolated, adipose SVF cells promote vasomotor relaxation in vasoactive arteries via a hydrogen peroxide-<span class="hlt">dependent</span> mechanism that required CD11b(+) cells (most likely macrophages). Given the significant impact of small artery dysfunction in disease, we predict that the intravenous delivery of this therapeutic cell preparation would significantly improve tissue perfusion, particularly in diseases with diffuse vascular involvement. ©AlphaMed Press.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4367510','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4367510"><span>Systemically Delivered Adipose Stromal Vascular <span class="hlt">Fraction</span> Cells Disseminate to Peripheral Artery Walls and Reduce Vasomotor Tone Through a CD11b+ Cell-<span class="hlt">Dependent</span> Mechanism</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Morris, Marvin E.; Beare, Jason E.; Reed, Robert M.; Dale, Jacob R.; LeBlanc, Amanda J.; Kaufman, Christina L.; Zheng, Huaiyu; Ng, Chin K.; Williams, Stuart K.</p> <p>2015-01-01</p> <p>Vasoactivity, an important aspect of tissue healing, is often compromised in disease and tissue injury. Dysfunction in the smaller vasoactive arteries is most impactful, given the role of these vessels in controlling downstream tissue perfusion. The adipose stromal vascular <span class="hlt">fraction</span> (SVF) is a mix of homeostatic cells shown to promote tissue healing. Our objective was to test the hypothesis that autologous SVF cells therapeutically modulate peripheral artery vasoactivity in syngeneic mouse models of small artery function. Analysis of vasoactivity of saphenous arteries isolated from normal mice 1 week after intravenous injection of freshly isolated SVF cells revealed that pressure-<span class="hlt">dependent</span> artery vasomotor tone was decreased by the SVF cell isolate, but not one depleted of CD11b+ cells. Scavenging hydrogen peroxide in the vessel wall abrogated the artery relaxation promoted by the SVF cell isolate. Consistent with a CD11b+ cell being the relevant cell type, SVF-derived F4/80-positive macrophages were present within the adventitia of the artery wall coincident with vasorelaxation. In a model of artery inflammation mimicking a common disease condition inducing vasoactive dysfunction, the SVF cells potentiated relaxation of saphenous arteries without structurally remodeling the artery via a CD11b+ cell-<span class="hlt">dependent</span> manner. Our findings demonstrate that freshly isolated, adipose SVF cells promote vasomotor relaxation in vasoactive arteries via a hydrogen peroxide-<span class="hlt">dependent</span> mechanism that required CD11b+ cells (most likely macrophages). Given the significant impact of small artery dysfunction in disease, we predict that the intravenous delivery of this therapeutic cell preparation would significantly improve tissue perfusion, particularly in diseases with diffuse vascular involvement. PMID:25722428</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PPNL....9...96D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PPNL....9...96D"><span>Comparative analysis of <span class="hlt">deuterium</span> ions implanted and <span class="hlt">deuterium</span> atoms saturated at high pressure in pure pd and Pd diluted alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Didyk, A. Yu.; Kulikauskas, V. S.; Wiśniewski, R.; Wilczynska, T.; Kitowski, K.</p> <p>2012-01-01</p> <p>Pd and its diluted alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV <span class="hlt">deuterium</span> ions at a fluence interval of (1.2-2.3) × 1022 m-2. The same property alloys were saturated by <span class="hlt">deuterium</span> atoms using high pressure chamber during long period with temperature stabilization and electrical resistance measurement of standard Pd wire. The post-treatment depth distributions of <span class="hlt">deuterium</span> and accompanied hydrogen atoms were measured immediately after implantation (ten days) and after definite time period (three months) after saturation with the usage of elastic recoil detection analysis (ERDA). After two months, the measurements were repeated. The comparison of obtained results in both series of studies allowed one to make an important observation of a relative stability of <span class="hlt">deuterium</span> and hydrogen atoms in pure Pd and its diluted alloys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/917468','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/917468"><span>Equations of state for hydrogen and <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kerley, Gerald Irwin (Kerley Technical Services, Appomattox, VA)</p> <p>2003-12-01</p> <p>This report describes the complete revision of a <span class="hlt">deuterium</span> equation of state (EOS) model published in 1972. It uses the same general approach as the 1972 EOS, i.e., the so-called 'chemical model,' but incorporates a number of theoretical advances that have taken place during the past thirty years. Three phases are included: a molecular solid, an atomic solid, and a fluid phase consisting of both molecular and atomic species. Ionization and the insulator-metal transition are also included. The most important improvements are in the liquid perturbation theory, the treatment of molecular vibrations and rotations, and the ionization equilibrium and mixture models. In addition, new experimental data and theoretical calculations are used to calibrate certain model parameters, notably the zero-Kelvin isotherms for the molecular and atomic solids, and the quantum corrections to the liquid phase. The report gives a general overview of the model, followed by detailed discussions of the most important theoretical issues and extensive comparisons with the many experimental data that have been obtained during the last thirty years. Questions about the validity of the chemical model are also considered. Implications for modeling the 'giant planets' are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920003661','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920003661"><span><span class="hlt">Deuterium</span> on Venus: Observations from Earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lutz, Barry L.; Debergh, C.; Bezard, B.; Owen, T.; Crisp, D.; Maillard, J.-P.</p> <p>1991-01-01</p> <p>In view of the importance of the <span class="hlt">deuterium</span>-to-hydrogen ratio in understanding the evolutionary scenario of planetary atmospheres and its relationship to understanding the evolution of our own Earth, we undertook a series of observations designed to resolve previous observational conflicts. We observed the dark side of Venus in the 2.3 micron spectral region in search of both H2O and HDO, which would provide us with the D/H ratio in Venus' atmosphere. We identified a large number of molecular lines in the region, belonging to both molecules, and, using synthetic spectral techniques, obtained mixing ratios of 34 plus or minus 10 ppm and 1.3 plus or minus 0.2 ppm for H2O and HDO, respectively. These mixing ratios yield a D/H ratio for Venus of D/H equals 1.9 plus or minus 0.6 times 10 (exp 12) and 120 plus or minus 40 times the telluric ratio. Although the detailed interpretation is difficult, our observations confirm that the Pioneer Venus Orbiter results and establish that indeed Venus had a period in its early history in which it was very wet, perhaps not unlike the early wet period that seems to have been present on Mars, and that, in contrast to Earth, lost much of its water over geologic time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.600..338P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.600..338P"><span>Muon capture experiments in hydrogen and <span class="hlt">deuterium</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petitjean, Claude</p> <p>2009-02-01</p> <p>We report about new muon lifetime precision experiments at PSI to measure the singlet μp capture rate ΛS to ⩽1% and the doublet μd capture rate ΛD to ⩽1.5%. The goal is to determine precisely the induced pseudoscalar coupling gP from ΛS, and the axial two-body current term L1A from ΛD. We have developed a new hydrogen time projection chamber (TPC) operating at 10 bar as active muon stop detector. It is surrounded by cylindrical wire chambers and a plastic hodoscope as electron detector. Ultra-high purity of the hydrogen gas ( cZ<10 -7) was accomplished by continuous gas circulation and purification. Isotopic purity cd<10 -8 was achieved with a special isotope separation column. In total, ˜1.5×10 10 good events were collected which are now in final analysis. Our first result from 10% of the statistics, gP=7.3±1.1, agrees well with the theory. The μd experiment is now in development. We will use a new TPC operating in <span class="hlt">deuterium</span> gas at T˜30 K. The proposed experimental setup is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7188745','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7188745"><span>Absolute measurement of the photodisintegration of <span class="hlt">deuterium</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Knott, J.E.</p> <p>1988-01-01</p> <p>This experiment measured the differential cross section for deuteron photodisintegration between photon energies of 63 and 71 MeV. The photon beam was produced by the bremsstrahlung of an 88.4 MeV CW electron beam, from the University of Illinois Nuclear Physics Laboratory electron microtron, in a 1.4 {times} 10{sup {minus}3} radiation length aluminum converter. The photon energy was determined to .25 MeV by the technique of bremsstrahlung tagging. The <span class="hlt">deuterium</span> target gas, at atmospheric pressure, was contained in a thin walled cylinder 2.4 m long. The protons from deuteron photo-disintegration were detected in the LArge Solid Angle detector, which was built for this experiment. The LASA detector consists of three concentric, cylindrical MWPC chambers surrounded by segmented plastic scintillators. The target cylinder is on the axis of the chamber. Particles were collected from 20{degrees} to 160{degrees}, the angle determined by the charge division technique in the wire chamber. The de/dx measurements in the wire chamber and the scintillators allowed the separation of protons from electrons. The differential cross sections have been fit by Legendre polynomials. These results are in reasonable agreement with previous experiments and theoretical calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21287056','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21287056"><span>Density of states in solid <span class="hlt">deuterium</span>: Inelastic neutron scattering study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Frei, A.; Gutsmiedl, E.; Morkel, C.; Mueller, A. R.; Paul, S.; Urban, M.; Schober, H.; Rols, S.; Unruh, T.; Hoelzel, M.</p> <p>2009-08-01</p> <p>The dynamics of solid <span class="hlt">deuterium</span> (sD{sub 2}) is studied by means of inelastic scattering (coherent and incoherent) of thermal and cold neutrons at different temperatures and para-ortho ratios. In this paper, the results for the generalized density of states (GDOS) are presented and discussed. The measurements were performed at the thermal neutron time-of-flight (TOF) instrument IN4 at ILL Grenoble and at the cold neutron TOF instrument TOFTOF at FRM II Garching. The GDOS comprises besides the hcp phonon excitations of the sD{sub 2} the rotational transitions J=0{yields}1 and J=1{yields}2. The intensities of these rotational excitations <span class="hlt">depend</span> strongly on the ortho-D{sub 2} molecule concentration c{sub o} in sD{sub 2}. Above E=10 meV there are still strong excitations, which very likely may originate from higher-energy damped optical phonons and multiphonon contributions. A method for separating the one-phonon and multiphonon contributions to the density of states will be presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004Natur.431..437W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004Natur.431..437W"><span>Complete photo-fragmentation of the <span class="hlt">deuterium</span> molecule</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, T.; Czasch, A. O.; Jagutzki, O.; Müller, A. K.; Mergel, V.; Kheifets, A.; Rotenberg, E.; Meigs, G.; Prior, M. H.; Daveau, S.; Landers, A.; Cocke, C. L.; Osipov, T.; Díez Muiño, R.; Schmidt-Böcking, H.; Dörner, R.</p> <p>2004-09-01</p> <p>All properties of molecules-from binding and excitation energies to their geometry-are determined by the highly correlated initial-state wavefunction of the electrons and nuclei. Details of these correlations can be revealed by studying the break-up of these systems into their constituents. The fragmentation might be initiated by the absorption of a single photon, by collision with a charged particle or by exposure to a strong laser pulse: if the interaction causing the excitation is sufficiently understood, the fragmentation process can then be used as a tool to investigate the bound initial state. The interaction and resulting fragment motions therefore pose formidable challenges to quantum theory. Here we report the coincident measurement of the momenta of both nuclei and both electrons from the single-photon-induced fragmentation of the <span class="hlt">deuterium</span> molecule. The results reveal that the correlated motion of the electrons is strongly <span class="hlt">dependent</span> on the inter-nuclear separation in the molecular ground state at the instant of photon absorption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..462.1161T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..462.1161T"><span><span class="hlt">Fractional</span> randomness</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tapiero, Charles S.; Vallois, Pierre</p> <p>2016-11-01</p> <p>The premise of this paper is that a <span class="hlt">fractional</span> probability distribution is based on <span class="hlt">fractional</span> operators and the <span class="hlt">fractional</span> (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a <span class="hlt">fractional</span> density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a <span class="hlt">fractional</span> kernel may have properties that differ due to the <span class="hlt">fractional</span> index used and the <span class="hlt">fractional</span> calculus applied to define it. The purpose of this paper is to consider an application of <span class="hlt">fractional</span> calculus to define the <span class="hlt">fractional</span> density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define <span class="hlt">fractional</span> probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to <span class="hlt">fractional</span> calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical <span class="hlt">fractional</span> models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70044451','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70044451"><span>Mass <span class="hlt">fractionation</span> of noble gases in synthetic methane hydrate: Implications for naturally occurring gas hydrate dissociation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hunt, Andrew G.; Stern, Laura; Pohlman, John W.; Ruppel, Carolyn; Moscati, Richard J.; Landis, Gary P.</p> <p>2013-01-01</p> <p>As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings may presently be dissociating and releasing methane and other gases to the ocean-atmosphere system. A key challenge in assessing the impact of dissociating gas hydrates on global atmospheric methane is the lack of a technique able to distinguish between methane recently released from gas hydrates and methane emitted from leaky thermogenic reservoirs, shallow sediments (some newly thawed), coal beds, and other sources. Carbon and <span class="hlt">deuterium</span> stable isotopic <span class="hlt">fractionation</span> during methane formation provides a first-order constraint on the processes (microbial or thermogenic) of methane generation. However, because gas hydrate formation and dissociation do not cause significant isotopic <span class="hlt">fractionation</span>, a stable isotope-based hydrate-source determination is not possible. Here, we investigate patterns of mass-<span class="hlt">dependent</span> noble gas <span class="hlt">fractionation</span> within the gas hydrate lattice to fingerprint methane released from gas hydrates. Starting with synthetic gas hydrate formed under laboratory conditions, we document complex noble gas <span class="hlt">fractionation</span> patterns in the gases liberated during dissociation and explore the effects of aging and storage (e.g., in liquid nitrogen), as well as sampling and preservation procedures. The laboratory results confirm a unique noble gas <span class="hlt">fractionation</span> pattern for gas hydrates, one that shows promise in evaluating modern natural gas seeps for a signature associated with gas hydrate dissociation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.118w3401S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.118w3401S"><span>Highly Nuclear-Spin-Polarized <span class="hlt">Deuterium</span> Atoms from the UV Photodissociation of <span class="hlt">Deuterium</span> Iodide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sofikitis, Dimitris; Glodic, Pavle; Koumarianou, Greta; Jiang, Hongyan; Bougas, Lykourgos; Samartzis, Peter C.; Andreev, Alexander; Rakitzis, T. Peter</p> <p>2017-06-01</p> <p>We report a novel highly spin-polarized <span class="hlt">deuterium</span> (SPD) source, via the photodissociation of <span class="hlt">deuterium</span> iodide at 270 nm. I (<mml:mmultiscripts>P2 </mml:mmultiscripts> 3 /2) photofragments are ionized with m -state selectivity, and their velocity distribution measured via velocity-map slice imaging, from which the D polarization is determined. The process produces ˜100 % electronically polarized D at the time of dissociation, which is then converted to ˜60 % nuclear D polarization after ˜1.6 ns . These production times for SPD allow collision-limited densities of ˜1 018 cm-3 and at production rates of ˜1 021 s-1 which are 1 06 and 1 04 times higher than conventional (Stern-Gerlach separation) methods, respectively. We discuss the production of SPD beams, and combining high-density SPD with laser fusion, to investigate polarized D-T, D -<mml:mmultiscripts>He 3 </mml:mmultiscripts> , and D-D fusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24957134','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24957134"><span>A chemically defined 2,3-trans procyanidin <span class="hlt">fraction</span> from willow bark causes redox-sensitive endothelium-<span class="hlt">dependent</span> relaxation in porcine coronary arteries.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaufeld, Aurica M; Pertz, Heinz H; Kolodziej, Herbert</p> <p>2014-07-25</p> <p>Extracts of the bark of willow species (Salix spp.) are popular herbal remedies to relieve fever and inflammation. The effects are attributed to salicin and structurally related phenolic metabolites, while polyphenols including procyanidins are suggested to contribute to the overall effect of willow bark. This study aimed at investigating the relaxant response to a highly purified and chemically defined 2,3-trans procyanidin <span class="hlt">fraction</span> in porcine coronary arteries. The procyanidin sample produced a concentration-<span class="hlt">dependent</span> relaxation in U46619-precontracted tissues. Relaxation was predominantly mediated through the redox-sensitive activation of the endothelial phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway, leading to the subsequent activation of endothelial nitric oxide synthase (eNOS) by phosphorylation, as evidenced by Western blotting using human umbilical vein endothelial cells (HUVECs). That the relaxant response to Salix procyanidins was reactive oxygen species (ROS)-<span class="hlt">dependent</span> with O2(-) as the key species followed from densitometric analysis using 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA assay) and employment of various ROS inhibitors, respectively. The data also suggested the modification of intracellular Ca(2+) levels and KCa channel functions. In addition, our organ bath studies showed that Salix procyanidins reversed the abrogation of the relaxant response to bradykinin by oxidized low-density lipoproteins (oxLDL) in coronary arteries, suggesting a vasoprotective effect of willow bark against detrimental oxLDL in pathological conditions. Taken together, our findings suggest for the first time that 2,3-trans procyanidins may contribute not only to the beneficial effects of willow bark but also to health-promoting benefits of diverse natural products of plant origin.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017isms.confEMG08H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017isms.confEMG08H"><span>The Role of Perturbations in the B-X UV Spectrum of S_{2} in a Temperature-<span class="hlt">Dependent</span> Mechanism for Sulfur Mass Independent <span class="hlt">Fractionation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, Alexander W.; Field, Robert W.; Ono, Shuhei</p> <p>2017-06-01</p> <p>Sulfur mass independent <span class="hlt">fractionation</span> (S-MIF) describes anomalous sulfur isotope ratios commonly found in sedimentary rocks older than 2.45 billion years. These anomalies likely originate from photochemistry of small, sulfur-containing molecules in the atmosphere, and their sudden disappearance from rock samples younger than 2.45 years is thought to be correlated with a sharp rise in atmospheric oxygen levels. The emergence of atmospheric oxygen is an important milestone in the development of life on Earth, but the mechanism for sulfur MIF in an anoxic atmosphere is not well understood. In this context, we present an analysis of the B-X UV spectrum of S_{2}, an extension of work presented last year. The B state of S_{2} is strongly perturbed by the nearby B" state, as originally described by Green and Western (1996). Our analysis suggests that a doorway-mediated transfer mechanism shifts excited state population from the short-lifetime B state to the longer-lifetime B" state. Furthermore, access to the perturbed doorway states is strongly <span class="hlt">dependent</span> on the population distribution in the ground state. This suggests that the temperature of the Achaean atmosphere may have played a significant role in determining the extent of S-MIF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11306134','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11306134"><span>UT841 purified from sea urchin (Toxopneustes pileolus) venom inhibits time-<span class="hlt">dependent</span> (45)Ca(2+) uptake in crude synaptosome <span class="hlt">fraction</span> from chick brain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Y; Abe, J; Siddiq, A; Nakagawa, H; Honda, S; Wada, T; Ichida, S</p> <p>2001-08-01</p> <p>To clarify the mechanism by which the toxic abstract from Toxopneustes pileolus inhibits time-<span class="hlt">dependent</span> (Time-dep.) Ca(2+) uptake in crude synaptosome <span class="hlt">fraction</span>, the effective component from pedicellarial venom of the sea urchin was purified. The crude extracts were purified by a series of steps including ion exchange (DEAE-sephadex-A25 gel), gel filtration (with Superdex-2000 and Superdex-peptide columns) and reversed-phase chromatography (Sephasil-C18 column). The effective component that inhibited Time-dep. 45Ca(2+) uptake was purified and named UT841. Its IC(50) was determined to be lower than 35ng/ml. UT841 is an acidic protein with an apparent molecular weight of about 18,000. The N-terminal sequence (40 amino acids) was almost identical to that of Contractin A (a protein purified from the same kind of venom which induces smooth muscle contraction). Even though it is unclear whether or not UT841 is Contractin A, Ca(2+) mobilization in nerve cells was shown to be influenced by UT841. This investigation also revealed that a donor of nitric oxide, arachidonic acid and an inhibitor of phospholipase C selectively inhibit Time-dep. (45)Ca(2+) uptake. These results suggest that UT841 purified from sea urchin venom may affect Time-dep. (45)Ca(2+) uptake through the metabolism of some lipids and nitric oxide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/892614','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/892614"><span>Measurement of the Branching <span class="hlt">Fraction</span> and Time-<span class="hlt">Dependent</span> CP Asymmetry in the Decay B0 to D*+D*-Ks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aubert, B.</p> <p>2006-09-26</p> <p>The authors study the decay B{sup 0} {yields} D*{sup +}D*{sup -} K{sub S}{sup 0} using (230 {+-} 2) x 10{sup 6} B{bar B} pairs collected by the BABAR detector at the PEP-II B factory. They measure a branching <span class="hlt">fraction</span> {Beta}(B{sup 0} {yields} D*{sup +}D*{sup -} K{sub S}{sup 0}) = (4.4 {+-} 0.4 {+-} 0.7) x 10{sup -3} and find evidence for the decay B{sup 0} {yields} D*{sup -} D{sub s1}{sup +}(2536) with a statistical significance of 4.6 {sigma}. A time-<span class="hlt">dependent</span> CP asymmetry analysis is also performed to study the possible resonant contributions to B{sup 0} {yields} D*{sup +}D*{sup -} K{sub S}{sup 0} and the sign of cos2{beta}. Their measurement indicates that there is a sizable resonant contribution to the decay B{sup 0} {yields} D*{sup +} D*{sup -} K{sub S}{sup 0} from a unknown D{sub s1}{sup +} state with large width, and that cos2{beta} is positive at the 94% confidence level under certain theoretical assumptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PlST...18..751N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PlST...18..751N"><span>N2 Mole <span class="hlt">Fraction</span> <span class="hlt">Dependence</span> of Plasma Bullet Propagation in Premixed He/N2 Plasma Needle Discharge at Atmospheric Pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ni, Gengsong; Qian, Muyang; Yang, Congying; Liu, Sanqiu; Wang, Dezhen</p> <p>2016-07-01</p> <p>In this work, a computational modeling study on the mechanism of the acceleration behavior of a plasma bullet in needle-plane configuration is presented. Above all, in our model, two sub-models of time-<span class="hlt">dependent</span> plasma dynamics and laminar flow are connected using a oneway coupled method, and both the working gas and the surrounding gas around the plasma jet are assumed to be the same, which are premixed He/N2 gas. The mole <span class="hlt">fractions</span> of the N2 (NMF) ingredient are set to be 0.01%, 0.1% and 1% in three cases, respectively. It is found that in each case, the plasma bullet accelerates with time to a peak velocity after it exits the nozzle and then decreases until getting to the treated surface, and that the velocity of the plasma bullet increases at each time moment with the peak value changing from 0.72×106 m/s to 0.80×106 m/s but then drops more sharply when the NMF varies from 0.01% to 1%. Besides, the electron impact ionizations of helium neutrals and nitrogen molecules are found to have key influences on the propagation of a plasma bullet instead of the penning ionization. supported by National Natural Science Foundation of China (No. 11465013), the Natural Science Foundation of Jiangxi Province, China (No. 20151BAB212012), and in part by the International Science and Technology Cooperation Program of China (No. 2015DFA61800)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22047410','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22047410"><span>Measurements and monitoring of the hydrogen and <span class="hlt">deuterium</span> contents in the plasma of the L-2M stellarator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Voronov, G. S.; Berezhetskii, M. S.</p> <p>2012-04-15</p> <p>The program of experiments on ITER includes a sequential change of the plasma isotopic composition from pure hydrogen plasma in the initial stage of research to <span class="hlt">deuterium</span> and, then, <span class="hlt">deuterium</span>-tritium plasma with a gradual increase in the tritium content. In this context, the influence of the plasma isotopic composition on the processes of plasma heating and confinement are being actively studied on the existing tokamaks and stellarators. The plasma isotopic composition also <span class="hlt">depends</span> on the composition of the gas desorbed from the vacuum chamber wall in the course of recycling. Therefore, the rate of change of the plasma isotopic composition after altering the injected gas also <span class="hlt">depends</span> on the rate of change of the isotopic composition of the gas absorbed in the wall. These effects were studied in the experiments carried out on the L-2M stellarator in which the working gas was changed from hydrogen to <span class="hlt">deuterium</span>. Spectral measurements of the intensity ratio between the H{sub {alpha}} and D{sub {alpha}} lines made it possible to monitor the isotopic composition of the plasma in the course of cleaning of the chamber wall from earlier absorbed hydrogen and its replacement with <span class="hlt">deuterium</span>. After returning to hydrogen, the rate of cleaning of the wall from <span class="hlt">deuterium</span> was also determined. The results of these experiments show that the plasma isotopic composition varies exponentially with the number N of shots after transition to another isotope, {approx}exp(-N/47). Hence, the isotopic composition can be changed almost completely over 2 to 3 working days. This allows one to study the influence of the plasma isotopic composition on plasma confinement during the same experimental session.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11671032','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11671032"><span>A <span class="hlt">Deuterium</span> NMR Spectroscopic Study of Solid BH(3)NH(3).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Penner, Glenn H.; Chang, Y. C. Phillis; Hutzal, Jennifer</p> <p>1999-06-14</p> <p><span class="hlt">Deuterium</span> nuclear magnetic resonance (NMR) powder spectra and spin-lattice relaxation times (T(1)) are used to measure the <span class="hlt">deuterium</span> quadrupolar coupling constants (QCCs) chi(BD) and chi(ND) and to investigate the molecular reorientation of the BD(3) and ND(3) groups in solid deuterated borane monoammoniate, BD(3)NH(3) and BH(3)ND(3), respectively. In the high-temperature, tetragonal, phase (above 225 K) the following Arrhenius parameters are obtained from the temperature-<span class="hlt">dependent</span> T(1): E(a) = 5.9 +/- 0.5 kJ/mol and tau(infinity) = 1.1 x 10(-)(13) s for BD(3)NH(3); E(a) = 7.3 +/- 0.8 kJ/mol and tau(infinity) = 4.4 x 10(-)(14) s for BH(3)ND(3). In the low-temperature, orthorhombic, phase the following parameters are obtained: E(a) = 26.4 +/- 1.4 kJ/mol and tau(infinity) = 1.2 x 10(-)(17) s for BD(3)NH(3); E(a) = 13.7 +/- 0.9 kJ/mol and tau(infinity) = 5.7 x 10(-)(15) s for BH(3)ND(3). Here tau(infinity) is proportional to the inverse of the usual Arrhenius preexponential factor, A. <span class="hlt">Deuterium</span> line shape measurements for the low-temperature phase of BD(3)NH(3) yield E(a) = 25 +/- 2 kJ/mol and tau(infinity) = 4.7 x 10(-)(19) s. These dynamic factors indicate that the molecule is probably undergoing whole molecule rotation above the phase transition but the BH(3) and NH(3) groups are undergoing uncorrelated motion in the low-temperature phase. <span class="hlt">Deuterium</span> quadrupolar coupling constants of 105 +/- 10 and 200 +/- 10 kHz were determined for BD(3)NH(3) and BH(3)ND(3), respectively. Molecular orbital (MO) calculations (CI(SD)/6-31G(d,p)//MP2/6-31G(d,p)) for the isolated molecule yield values of 143 and 255 kHz. MO calculations also show that the <span class="hlt">deuterium</span> quadrupolar coupling constants chi(BD) and chi(ND) are relatively insensitive to all molecular structural parameters except the B-H and N-H bond lengths, respectively. It is suggested that the large decrease in the QCC on going from the gas phase to the solid state may be due to a slight lengthening of the B-H and N-H bonds</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21538141','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21538141"><span>Chemical response of lithiated graphite with <span class="hlt">deuterium</span> irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Taylor, C. N.; Heim, B.; Allain, J. P.</p> <p>2011-03-01</p> <p>Lithium wall conditioning has been found to enhance plasma performance for graphite walled fusion devices such as TFTR, CDX-U, T-11M, TJ-II and NSTX. Among observed plasma enhancements is a reduction in edge density and reduced <span class="hlt">deuterium</span> recycling. The mechanism by which lithiated graphite retains <span class="hlt">deuterium</span> is largely unknown. Under controlled laboratory conditions, X-ray photoelectron spectroscopy (XPS) is used to observe the chemical changes that occur on ATJ graphite after lithium deposition. The chemical state of lithiated graphite is found to change upon <span class="hlt">deuterium</span> irradiation indicating the formation Li-O-D, manifest at 532.9 {+-} 0.6 eV. Lithium-<span class="hlt">deuterium</span> interactions are also manifest in the C 1s photoelectron energy range and show Li-C-D interactions at 291.2 {+-} 0.6 eV. Post-mortem NSTX tiles that have been exposed to air upon extraction are cleaned and examined, revealing the chemical archaeology that formed during NSTX operations. XPS spectra show strong correlation ({+-} 0.3 eV) in Li-O-D and Li-O peaks from post-mortem and control experiments, thus validating offline experiments. We report findings that show that <span class="hlt">deuterium</span> is found to interact with lithium after lithium has already reacted with carbon and oxygen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JAP...109e3306T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JAP...109e3306T"><span>Chemical response of lithiated graphite with <span class="hlt">deuterium</span> irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, C. N.; Heim, B.; Allain, J. P.</p> <p>2011-03-01</p> <p>Lithium wall conditioning has been found to enhance plasma performance for graphite walled fusion devices such as TFTR, CDX-U, T-11M, TJ-II and NSTX. Among observed plasma enhancements is a reduction in edge density and reduced <span class="hlt">deuterium</span> recycling. The mechanism by which lithiated graphite retains <span class="hlt">deuterium</span> is largely unknown. Under controlled laboratory conditions, X-ray photoelectron spectroscopy (XPS) is used to observe the chemical changes that occur on ATJ graphite after lithium deposition. The chemical state of lithiated graphite is found to change upon <span class="hlt">deuterium</span> irradiation indicating the formation Li-O-D, manifest at 532.9 ± 0.6 eV. Lithium-<span class="hlt">deuterium</span> interactions are also manifest in the C 1s photoelectron energy range and show Li-C-D interactions at 291.2 ± 0.6 eV. Post-mortem NSTX tiles that have been exposed to air upon extraction are cleaned and examined, revealing the chemical archaeology that formed during NSTX operations. XPS spectra show strong correlation (± 0.3 eV) in Li-O-D and Li-O peaks from post-mortem and control experiments, thus validating offline experiments. We report findings that show that <span class="hlt">deuterium</span> is found to interact with lithium after lithium has already reacted with carbon and oxygen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000DPS....32.6530K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000DPS....32.6530K"><span>D/H <span class="hlt">Fractionation</span> in Circumstellar Disks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kessler, J. E.; Qi, C.; Blake, G. A.</p> <p>2000-12-01</p> <p>In recent years millimeter-wave interferometers have imaged the gas and dust surrounding over a dozen T Tauri and Herbig Ae stars (see Sargent 1996 in Disks and Outflows from Young Stars, pp. 1-23, for review). These studies demonstrate the potential to improve dramatically our understanding of disk physical and chemical structure, providing unique insights that will ultimately enable a more comprehensive understanding of star and planet formation. In particular, through the comparison of disk properties such as (D/H) <span class="hlt">fractionation</span> with those of comets and Kuiper belt objects the origin of primitive solar system bodies can be investigated. In this study, 1.3 mm transitions of the deuterated species DCN and HDO were detected toward the T Tauri star LkCa 15 using the Owens Valley Radio Observatory Millimeter Array (for previous observations of various molecules toward LkCa 15 see Qi, PhD thesis, 2000). The resulting DCN abundance was compared to that found for HCN and H13CN. The measured intensity ratios of the (DCN/HCN) transitions lead to (D/H) ratios of <0.5, but are clearly influenced by opacity in the HCN 1-0 transition. Observations of the optically thin isotope H13CN, yield an estimated DCN/HCN ratio of ~ 0.01. This value is much larger than the estimated protosolar D/H of ~ 1.6e-5 (Gautier & Morel 1997 A&A 323, L9) and quite close to that observed in dark molecular clouds, 0.01-0.05 (Wooten 1987 Astrochem 120, 311), indicating that the assignment of cometary origin using D/H <span class="hlt">fractionation</span> is a complicated endeavor. Through the combination of the observations presented here and chemical models of circumstellar material, the temperature <span class="hlt">dependence</span> of <span class="hlt">fractionation</span> and enrichment of <span class="hlt">deuterium</span> through gas-grain surface reactions can be explored. Further, although H2O cannot be observed and thus HDO/H2O was not measured, differences in the morphology of maps of the observed emission from DCN and HDO may shed light on differences in <span class="hlt">fractionation</span> seen in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22398787','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22398787"><span><span class="hlt">Deuterium</span> absorption from the D{sub 2}O exposure of oxidized 4H-SiC (0001), (0001{sup ¯}), and (112{sup ¯}0) surfaces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, Gang; Xu, Can; Feldman, Leonard C.; Yakshinskiy, Boris; Wielunski, Leszek; Gustafsson, Torgny; Bloch, Joseph; Dhar, Sarit</p> <p>2015-03-23</p> <p>We report results on <span class="hlt">deuterium</span> absorption on several oxidized 4H-SiC surfaces following D{sub 2}O vapor absorption. Absorption at the oxide/semiconductor interface is strongly face <span class="hlt">dependent</span> with an order of magnitude more <span class="hlt">deuterium</span> on the C-face and a-face than on the Si-face, in contrast to the bulk of the oxides which show essentially no face <span class="hlt">dependence</span>. Annealing in NO gas produces a large reduction in interfacial <span class="hlt">deuterium</span> absorption in all cases. The reduction of the positive charge at the interface scales linearly with the interface D content. These results also scale with the variation in interface trap density (D{sub it}) and mobility on the three faces after wet oxidation annealing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JChPh.146d1101J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JChPh.146d1101J"><span>Communication: Dissolution DNP reveals a long-lived <span class="hlt">deuterium</span> spin state imbalance in methyl groups</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jhajharia, Aditya; Weber, Emmanuelle M. M.; Kempf, James G.; Abergel, Daniel; Bodenhausen, Geoffrey; Kurzbach, Dennis</p> <p>2017-01-01</p> <p>We report the generation and observation of long-lived spin states in deuterated methyl groups by dissolution DNP. These states are based on population imbalances between manifolds of spin states corresponding to irreducible representations of the C3v point group and feature strongly dampened quadrupolar relaxation. Their lifetime <span class="hlt">depends</span> on the activation energies of methyl group rotation. With dissolution DNP, we can reduce the <span class="hlt">deuterium</span> relaxation rate by a factor up to 20, thereby extending the experimentally available time window. The intrinsic limitation of NMR spectroscopy of quadrupolar spins by short relaxation times can thus be alleviated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NucFu..57c4003J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NucFu..57c4003J"><span>Subsurface <span class="hlt">deuterium</span> bubble formation in W due to low-energy high flux <span class="hlt">deuterium</span> plasma exposure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jia, Y. Z.; Liu, W.; Xu, B.; Qu, S. L.; Shi, L. Q.; Morgan, T. W.</p> <p>2017-03-01</p> <p>The <span class="hlt">deuterium</span> (D) bubbles formed in W exposed to high flux D plasma were researched by scanning electron microscopy and transmission electron microscopy. After D plasma exposure at 500 K and 1000 K, a layer of nano-sized bubbles were homogenously distributed in W subsurface region. The D bubbles were homogenously nucleated due to the high D concentration, and the nucleation process is not related to the vacancy defects. At low temperature (500 K), D bubbles can grow by surface blistering, which caused different nano scale morphologies on different surfaces. At high temperature (1000 K), D bubbles mainly grow by vacancy clustering, which caused pinholes on the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614036O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614036O"><span>Mass-<span class="hlt">dependent</span> and Mass-independent Sulphur Isotope <span class="hlt">Fractionation</span> Accompanying Thermal- and Photo-chemical Decomposition of Sulphur Bearing Organic Compounds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oduro, Harry; Izon, Gareth; Ono, Shuhei</p> <p>2014-05-01</p> <p>The bimodal S-isotope record, specifically the transition from mass independent (MIF) to mass <span class="hlt">dependent</span> <span class="hlt">fractionation</span> (MDF), is perhaps the most widely cited line of evidence for an irreversible rise in atmospheric oxygen at ca. 2.4Ga. The production and preservation of S-MIF, manifested in both Δ33S and Δ36S, within the geological record are linked to atmospheric O2 via a number of arguments. However, to date, the only mechanism capable of generating S-MIF consistent with the Archaean sedimentary records involves gas-phase ultraviolet irradiation of SO21 photolysis. More recently, Δ33S S-MIF trends have been reported from en vitro thermochemical sulphate reduction (TSR) experiments, prompting authors to question the importance of S-MIF as a proxy for Earth oxidation2. Importantly, whilst emerging TSR experiments3,4 affirm the reported Δ33S trends2, these experiments fail to identify correlated S-MIF between Δ33S and Δ36S values3,4. Realization that S-MIF is confined to Δ33S during TSR, precludes TSR as a mechanism responsible for the origin of the Archaean S-MIF record but strongly suggests the effect originating from a magnetic isotope effect (MIE) associated with 33S nucleus3,4. Clearly, photochemical and thermochemical processes impart different Δ36S/Δ33S trends with significant variation in δ34S; however, a complete experimental elucidation of mechanisms responsible for the S-MIF and S-MIE signatures is lacking. Interestingly, a complete understanding of the S-isotope chemistry during thermal- and photo-chemical decomposition may reveal wavelength and thermal <span class="hlt">dependence</span> archived in the sedimentary record. Here we extend the experimental database to explore the magnitude and sign of Δ36S/Δ33S and δ34S produced during both photo- and thermochemical processes. Here the organic sulphur compounds (OSC) utilized in these experiments carries diagnostic Δ36S/Δ33S patterns that differ from those reported from photolysis experiment SO2 and from the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/494289','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/494289"><span>Incorporation of <span class="hlt">deuterium</span> in coke formed on an acetylene hydrogenation catalyst</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Larsson, M.; Jansson, J.; Asplund, S.</p> <p>1996-09-01</p> <p>In selective hydrogenation of acetylene in excess ethylene, considerable amounts of coke or {open_quotes}green oils{close_quotes} are formed and accumulate on the catalyst. A <span class="hlt">fraction</span> of the acetylene undergoes oligomerization reactions producing C{sub 4}`s and larger hydrocarbons. Compounds larger than C{sub 8} are retained on the catalysts surface or as a condensed phase in the pore system. The reaction mechanism is largely unknown but several authors have postulated that oligomerization occurs through dissociatively adsorbed acetylene (2), i.e., C{sub 2}H(ads) and C{sub 2}(ads). In this paper a novel method of studying the coke formation on a catalyst is introduced. <span class="hlt">Deuterium</span> is incorporated in the coke during hydrogenation of acetylene, and during temperature-programmed oxidation (TPO) experiments the <span class="hlt">deuterium</span> content is analyzed. The objective is to shed some light on the mechanism for oligomer formation in this system. The catalyst, Pd/{alpha}-Al{sub 2}O{sub 3}, was prepared by the impregnation of {alpha}-alumina (Sued-Chemie) with a solution of Pd(NO{sub 3}){sub 2} in 30% HNO{sub 3}. 8 refs., 4 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......296S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......296S"><span>A dosimetry study of <span class="hlt">deuterium-deuterium</span> neutron generator-based in vivo neutron activation analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sowers, Daniel A.</p> <p></p> <p>A neutron irradiation cavity for in vivo Neutron Activation Analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized <span class="hlt">deuterium-deuterium</span> neutron generator which produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 x 108 +/-30% s-1. A moderator/reflector/shielding (5 cm high density polyethylene (HDPE), 5.3 cm graphite & 5.7 cm borated HDPE) assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeter (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and photon dose by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10 min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 +/- 0.8 mSv for neutron and 4.2 +/- 0.2 mSv for photon for 10 mins; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26509624','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26509624"><span>A Dosimetry Study of <span class="hlt">Deuterium-Deuterium</span> Neutron Generator-based In Vivo Neutron Activation Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H</p> <p>2015-12-01</p> <p>A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized <span class="hlt">deuterium-deuterium</span> neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1300M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1300M"><span>The discovery and modeling of energy <span class="hlt">dependent</span> time-lags and <span class="hlt">fractional</span> RMS of heartbeat state in GRS 1915+105</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mir, Mubashir; Iqbal, Naseer; Pahari, Mayukh; Misra, Ranjeev</p> <p>2016-07-01</p> <p>We report the discovery and modeling of enigmatic Energy <span class="hlt">dependent</span> time-lags and <span class="hlt">fractional</span> RMS of the heartbeat state in GRS 1915+105. The time-lags reveal the crucial information related to geometry of accretion flow, the emission regions and the relation between various spectral parameters. The lag and frms at the fundamental frequency show non-monotonic behavior with energy. The lag increases up to typically ˜10 keV and later shows a reversal and in some observations becomes hard(negative). However, the lags at the harmonic increase with energy and don't show any turn around at least till ˜20 keV. The frms at harmonic has similar non-monotonic behavior as at fundamental, however the variability amplitude is lesser as expected. The lag seen here can have magnitude of the order of seconds, and thus can't be accounted by light travel time effects or comptonization delays. The continuum X-ray spectra can roughly be described by a disk blackbody and a hard X-ray power-law component and from phase resolved spectroscopy it has been shown that the inner disk radius varies during the oscillation We propose the model based on the delayed response of inner disc (DRIOD) radius to the outer accretion rate i;e r_{in}(t)∝ dot{m}^β (t-τ_d). The fluctuating accretion rate varies the inner disk after a certain time delay t_d which could be of the order of the viscous propagation delays. The model very well explains the observed shape and nature of lags and frms at fundamental and harmonic frequencies. We present here the series of observations that constrain the four free parameters of our model. These parameters contain the vital information related to the nature of accretion flow in a highly periodic state like a heartbeat state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JKPS...63.1644Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JKPS...63.1644Y"><span>A study of the <span class="hlt">dependence</span> of protocol optimization on the left ventricular ejection <span class="hlt">fraction</span> (LVEF) in coronary CT angiography (CCTA) examination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Dong-Su; Cho, Jae-Hwan; Park, Cheol-Soo; Yoo, Heung-Joon; Choi, Cheon-Woong; Kim, Dae-Hyun</p> <p>2013-10-01</p> <p>The purpose of this study is to obtain a good quality image and to minimize patient doses and re-examination rates through an optimization of the protocol for coronary computed tomography angiography (CCTA) examination based on a comparison and an analysis of the heart rates (HRs) of patients who had left ventricular ejection <span class="hlt">fraction</span> (LVEF) values of less than 40% and the HRs of ordinary patients. This study targeted 16 patients who received thallium single-photon emission computed tomography (SPECT) or echocardiography simultaneously among the patients who took the CCTA examinations. <span class="hlt">Depending</span> on the LVEF value (30 ˜ 39, 40 ˜ 49, 50 ˜ 59, and 60% or above), the patients were divided into groups of four based on HR (50 ˜ 59, 60 ˜ 69, 70 ˜ 79, and 80 or above). DynEva software was used to set the region of interest (ROI) on the ascending aorta and for a measurement of the threshold value. Comparisons and analyses were made based on the LVEF values and the HRs, after which the results were compared with the ones from the existing examination protocols and contrast medium protocols. According to the study results, the relation between the HR and the LVEF demonstrated that it took a long time to reach the true 100 hounsfield unit (HU) when the LVEF was 40% or below. Contrasting media showed significant differences, except in the case where the HR was 80 or above, and/or the LVEF was less than 40%. Moreover, for an LVEF of less than 40%, time differences were significant when contrasting media reached the true 100 HU to begin the scanning process. Therefore, it was possible to predict that the contrasting media were already being washed out from the left ventricle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22e3102K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22e3102K"><span>Selective <span class="hlt">deuterium</span> ion acceleration using the Vulcan petawatt laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krygier, A. G.; Morrison, J. T.; Kar, S.; Ahmed, H.; Alejo, A.; Clarke, R.; Fuchs, J.; Green, A.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.</p> <p>2015-05-01</p> <p>We report on the successful demonstration of selective acceleration of <span class="hlt">deuterium</span> ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% <span class="hlt">deuterium</span> ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, > 10 20 W / cm 2 laser pulse by cryogenically freezing heavy water (D2O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°-8.5°), we find laser-to-<span class="hlt">deuterium</span>-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22820106J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22820106J"><span>Core <span class="hlt">Deuterium</span> Fusion and Radius Inflation in Hot Jupiters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaikumar, Prashanth; Rachid Ouyed</p> <p>2016-06-01</p> <p>Several laboratory-based studies have shown that the <span class="hlt">Deuterium</span> fusion cross-section is enhanced in a solid deuterated target as compared to a gas target, attributable to enhanced mobility of deuterons in a metal lattice. As an application, we propose that, for core temperatures and compositions characterizing hot Jupiters, screened <span class="hlt">Deuterium</span> fusion can occur deep in the interior, and show that the amount of radius inflation from this effect can be important if there is sufficient rock-ice in the core. The mechanism of screened <span class="hlt">Deuterium</span> fusion, operating in the above temperature range, is generally consistent with the trend in radius anomaly with planetary equilibrium temperature. We also explore the trend with planetary mass using a simple analytic model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25174785','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25174785"><span>Regioselective <span class="hlt">deuterium</span> labeling of estrone and catechol estrogen metabolites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stack, Douglas E; Ritonya, Justin; Jakopovic, Scott; Maloley-Lewis, Brittney</p> <p>2014-12-01</p> <p>Increased exposure to estrogens and estrogen metabolites is linked with increased rates of breast, ovarian and other human cancers. Metabolism of estrogen can led to formation of electrophilic o-quinones capable of binding to DNA. In order to gain insight into the mechanism of estrogen-induced DNA damage, estrone and catechol estrogens derived from estrone, have been regioselectively labeled with <span class="hlt">deuterium</span> at the 1-position. Estrone-1-d, estrone-1,2,4-d3, 4-hydroxyestrone-1-d and 2-hydroxyestrone-1-d have been synthesized with or without <span class="hlt">deuteriums</span> at the 16-position. The key labeling step involves deuterated trifluoroacetic acid exchange catalyzed by t-butyl alcohol. This economical, straightforward labeling technique makes available a range of estrone compounds containing <span class="hlt">deuterium</span> at the 1-position. Copyright © 2014 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21390986','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21390986"><span>Large <span class="hlt">deuterium</span> isotope effects and their use: a historical review.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krumbiegel, Peter</p> <p>2011-03-01</p> <p>Isotope effects are differences in the properties of the isotopes of an element resulting in different reaction rates of a corresponding compound, in equilibrium constants and in the spectra. Shortly after the discovery of stable isotopes of hydrogen, oxygen, and carbon, Jacob Bigeleisen formulated a theory of isotope effects and calculated possible maximum values. Large isotope effects of (2)H (<span class="hlt">deuterium</span>) against (1)H (protium) were seen to possibly influence interpretations of reaction mechanisms if corresponding labelling is used. Much work was invested to ensure the safety of <span class="hlt">deuterium</span> use in men in spite of the large isotope effect. On the other hand, large <span class="hlt">deuterium</span> isotope effects gave rise to several practical applications. Examples are the enhancement of the stability of some technical products against oxidative and against hydrolytic degradation (oils, pharmaceuticals) as well as alterations of the detoxification metabolism of pharmaceuticals in vivo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21344667','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21344667"><span>Effects of nonequilibrium particle distributions in <span class="hlt">deuterium</span>-tritium burning</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Michta, David; Graziani, Frank; Luu, Thomas; Pruet, Jason</p> <p>2010-01-15</p> <p>The effects of nonequilibrium particle distributions resulting from rapid <span class="hlt">deuterium</span>-tritium burning in plasmas are investigated using a Fokker-Planck code that incorporates small-angle Coulomb scattering, bremsstrahlung, Compton scattering, and light-ion fusion. For inertial confinement fusion environments, it is found that deviations away from Maxwellian distributions for either <span class="hlt">deuterium</span> or tritium ions are small and result in 1% changes in the energy production rates. The <span class="hlt">deuterium</span> and tritium effective temperatures are not equal, but differ by only about 2.5% near the time of peak burn rate. Simulations with high Z (Xe) dopants show that the dopant temperature closely tracks that of the fuel. On the other hand, fusion product ion distributions are highly non-Maxwellian, and careful treatments of energy-exchange between these ions and other particles is important for determining burn rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780031572&hterms=capella+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcapella%2Bstar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780031572&hterms=capella+star&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcapella%2Bstar"><span><span class="hlt">Deuterium</span> and hydrogen in the local interstellar medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dupree, A. K.; Baliunas, S. L.; Shipman, H. L.</p> <p>1977-01-01</p> <p>Densities of neutral hydrogen and <span class="hlt">deuterium</span> are found from observation with the Copernicus satellite of the Ly-alpha line toward two nearby stars. The hydrogen density is 0.03 + or - 0.01 per cu cm toward Alpha Aur (Capella) and 0.20 + or - 0.05 per cu cm in the direction of Alpha Cen A, values indicating that the nearby (less than 14 pc) interstellar medium is inhomogeneous and can be of low density in certain directions. The ratios of <span class="hlt">deuterium</span> to hydrogen - 3.9 (+5.7, -1.7) by 10 to the -5th power and 0.24 (+0.12, -0.07) by 10 to the -5th power for Alpha Aur and Alpha Cen A, respectively - suggest that variations in the <span class="hlt">deuterium</span> abundance may exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26620531','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26620531"><span>Ion Mobility Spectrometry-Hydrogen <span class="hlt">Deuterium</span> Exchange Mass Spectrometry of Anions: Part 3. Estimating Surface Area Exposure by <span class="hlt">Deuterium</span> Uptake.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khakinejad, Mahdiar; Kondalaji, Samaneh Ghassabi; Donohoe, Gregory C; Valentine, Stephen J</p> <p>2016-03-01</p> <p>Gas-phase hydrogen <span class="hlt">deuterium</span> exchange (HDX), collision cross section (CCS) measurement, and molecular dynamics simulation (MDS) techniques were utilized to develop and compare three methods for estimating the relative surface area exposure of separate peptide chains within bovine insulin ions. Electrosprayed [M - 3H](3-) and [M - 5H](5-) insulin ions produced a single conformer type with respective collision cross sections of 528 ± 5 Å(2) and 808 ± 2 Å(2). [M - 4H](4-) ions were comprised of more compact (Ω = 676 ± 3 Å(2)) and diffuse (i.e., more elongated, Ω = 779 ± 3 Å(2)) ion conformer types. Ions were subjected to HDX in the drift tube using D2O as the reagent gas. Collision-induced dissociation was used to fragment mobility-selected, isotopically labeled [M - 4H](4-) and [M - 5H](5-) ions into the protein subchains. <span class="hlt">Deuterium</span> uptake levels of each chain can be explained by limited inter-chain isotopic scrambling upon collisional activation. Using nominal ion structures from MDS and a hydrogen accessibility model, the <span class="hlt">deuterium</span> uptake for each chain was correlated to its exposed surface area. In separate experiments, the per-residue <span class="hlt">deuterium</span> content for the protonated and deprotonated ions of the synthetic peptide KKDDDDDIIKIIK were compared. The differences in <span class="hlt">deuterium</span> content indicated the regional HDX accessibility for cations versus anions. Using ions of similar conformational type, this comparison highlights the complementary nature of HDX data obtained from positive- and negative-ion analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JASMS..27..462K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JASMS..27..462K"><span>Ion Mobility Spectrometry-Hydrogen <span class="hlt">Deuterium</span> Exchange Mass Spectrometry of Anions: Part 3. Estimating Surface Area Exposure by <span class="hlt">Deuterium</span> Uptake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.</p> <p>2016-03-01</p> <p>Gas-phase hydrogen <span class="hlt">deuterium</span> exchange (HDX), collision cross section (CCS) measurement, and molecular dynamics simulation (MDS) techniques were utilized to develop and compare three methods for estimating the relative surface area exposure of separate peptide chains within bovine insulin ions. Electrosprayed [M - 3H]3- and [M - 5H]5- insulin ions produced a single conformer type with respective collision cross sections of 528 ± 5 Å2 and 808 ± 2 Å2. [M - 4H]4- ions were comprised of more compact (Ω = 676 ± 3 Å2) and diffuse (i.e., more elongated, Ω = 779 ± 3 Å2) ion conformer types. Ions were subjected to HDX in the drift tube using D2O as the reagent gas. Collision-induced dissociation was used to fragment mobility-selected, isotopically labeled [M - 4H]4- and [M - 5H]5- ions into the protein subchains. <span class="hlt">Deuterium</span> uptake levels of each chain can be explained by limited inter-chain isotopic scrambling upon collisional activation. Using nominal ion structures from MDS and a hydrogen accessibility model, the <span class="hlt">deuterium</span> uptake for each chain was correlated to its exposed surface area. In separate experiments, the per-residue <span class="hlt">deuterium</span> content for the protonated and deprotonated ions of the synthetic peptide KKDDDDDIIKIIK were compared. The differences in <span class="hlt">deuterium</span> content indicated the regional HDX accessibility for cations versus anions. Using ions of similar conformational type, this comparison highlights the complementary nature of HDX data obtained from positive- and negative-ion analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhDT........20G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhDT........20G"><span>The <span class="hlt">deuterium</span> content of atmospheric molecular hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerst, Steven Gregory</p> <p>2000-09-01</p> <p>A new technique for the separation of molecular hydrogen (H2) from air and the determination of its <span class="hlt">deuterium</span> (D) content is presented. A high-pressure air sample in an aluminum cylinder is condensed at -196°C, whereby H2 contained in the air sample is enriched in the gaseous headspace above the liquefied air. The H2-enriched headspace is bled into a vacuum extraction line where the H2 is oxidized to H2O for cryogenic isolation from the air stream. The captured water is reduced back to H2 for determination of its D/H ratio via isotope-ratio mass spectrometry (δD is reported in permil (‰) vs. Vienna Standard Mean Ocean Water, where δD = ((D/H)sample/(D/H) VSMOW - 1)*1000‰). Air samples for δD analyses were collected in November-December 1998 on a transect from Seattle, WA, 48°N, to McMurdo, Antarctica, 71°S (n = 19), and over a two-year interval on the Washington Coast, 48°N (n = 11), and Point Barrow, AK, 71°N (n = 6). Results indicate that the average δD of global atmospheric H2 is +130 +/- 4‰, with average δD values of +123 +/- 3‰ and +138 +/- 8‰ in the northern and southern hemispheres, respectively. Comparison of background and polluted samples in the Seattle area indicate the δD of H2 produced by anthropogenic activities (e.g. automobiles) is -1961 +/- 10‰. Laboratory combustion studies of pine needles and pine branches indicate that the δD of H2 emitted during biomass burning is -293 +/- 60‰. The results of field experiments (n = 6) using a large chamber to isolate a volume of air in contact with soil imply that the H2 removed during soil uptake has a δD value 57 +/- 24‰ lower than that of atmospheric H2. The constraints that these preliminary isotopic measurements place on the global H2 budget are limited by the unmeasured isotopic composition of photochemically produced H2, δDhν. However, the global H2 isotope balance implies that the average global value of δDhν must be +130‰, and this value is demonstrated to be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005NuPhA.758..795L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005NuPhA.758..795L"><span><span class="hlt">Deuterium</span> Nucleosynthesis in AGN: Is D Cosmological?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lubowich, D. A.; Kuno, N.; Roberts, H.; Millar, T. J.; Henkel, C.; Pasachoff, J.; Mauersberger, R.</p> <p>2005-07-01</p> <p>Although <span class="hlt">deuterium</span> is predicted to be primarily cosmological, D can also be produced by cosmic-ray or γ-ray spallation reactions - possibly between high energy jets and the surrounding gas in AGN. We used the Nobeyama mm array with a 3" resolution (200 pc) in April 2003 to search for any enhanced D from the DCN J = 2 1 line in the 45"×45" (3 kpc) circumnuclear region of the Seyfert galaxy NGC 1068. NGC 1068 is an optimal target because it has jets, starburst activity, a circumuclear molecular ring and molecular disk, dense optically thick concentrations of HCN, and a low-energy X-ray flux of 1042 erg/s (the highest X-ray flux of any galaxy in which HCN has been detected and the flux required to produce high D abundances). Although DCN is detected in most Galactic or LMC molecular clouds with optically thick HCN, we did not detect DCN with Srms = 11 mJy/beam or Trms = 35.6 mK. Thus our 3σ upper limits are S⩽ 33 mJy/beam or Tmb ⩽ 106.7 mK and DCN/HCN⩽ 0.0044. Using our 5260 reaction chemical network we estimate the underlying D/H⩽ 1.5×10-5 less than or equal to but not greater than the local Galactic ISM D/H = 1.5 × 10-5. Thus there is no significant D production in the nuclear region of NGC 1068 and NGC 1068 has probably not had a recent period of activity with a γ-ray or cosmic-ray luminosity > 1042 erg/s. If jet-cloud nucleosynthesis produces significant amounts of D, then the D is either produced inside a very small nuclear region or transported outside the nuclear region whereby subsequent infall may continuously supply galactic nuclei with D. However, any enhanced D produced via spallation reactions would have been destroyed via astration due to the large AGN star formation rate. Our results are additional evidence that D is primarily cosmological and that AGN do not produce D.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980JChPh..72.5603M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980JChPh..72.5603M"><span><span class="hlt">Deuterium</span> separation at high pressure by nanosecond CO2 laser multiple-photon dissociation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marling, Jack B.; Herman, Irving P.; Thomas, Scott J.</p> <p>1980-05-01</p> <p>Photochemical <span class="hlt">deuterium</span> separation is evaluated at pressures up to 1 atm using 2 ns duration CO2 laser pulses to achieve multiple-photon dissociation (MPD) as the isotopic separation step. Photochemical performance is compared for Freon 123 (2,2-dichloro-1,1,1-trifluoroethane), difluoromethane, and trifluoromethane based on <span class="hlt">deuterium</span> optical selectivity in absorption, photoproduct yield, and single-step <span class="hlt">deuterium</span> enrichment factor. The absorption coefficient versus energy fluence is measured from 0.01 to 3 J/cm2 fluence for CF3CDCl2, CDF3, and CHDF2; added buffer gas results in an order-of-magnitude increase in the CDF3 absorption coefficient. The <span class="hlt">deuterium</span> optical selectivity in absorption at 0.5 J/cm2 fluence with added buffer is 80 for CF3CDCl2 at 10.65 μ, 800 for CHDF2 at 10.48 μ, and 2500 for CDF3 at 10.21 μ. The absorption coefficients and hence optical isotopic selectivities are <span class="hlt">dependent</span> on fluence, and the optical selectivity attains a maximum value of 8000 for CDF3 below 0.01 J/cm2 fluence. The <span class="hlt">deuterium</span>-bearing MPD photoproducts at high pressure are trifluoroethylene for Freon 123, hydrogen fluoride for trifluoromethane, and both hydrogen fluoride and monofluoroacetylene for difluoromethane. Yield data determined by gas chromatography are analyzed using a model describing MPD due to a focused Gaussian beam in an absorbing medium to remove compositional and geometrical effects; this analysis results in a saturation fluence (at which the dissociation probability approaches 100%) of 12±2 J/cm2 for CF3CDCl2, 20±2 J/cm2 for CDF3 buffered by 1 atm argon, 30±2 J/cm2 for CDF3 buffered by 60-400 Torr CHF3, and 22±3 J/cm2 for CHDF2 buffered by 100-400 Torr CH2F2. Near unity dissociation probabilities are obtained for samples unbuffered by argon with operating pressures up to 40 Torr for Freon 123, and up to 400 Torr for both difluoromethane and trifluoromethane; the methane derivatives are much more resistant to high pressure collisional quenching than</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PMB....61N.667J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PMB....61N.667J"><span>Extended T2-IVIM model for correction of TE <span class="hlt">dependence</span> of pseudo-diffusion volume <span class="hlt">fraction</span> in clinical diffusion-weighted magnetic resonance imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jerome, N. P.; d'Arcy, J. A.; Feiweier, T.; Koh, D.-M.; Leach, M. O.; Collins, D. J.; Orton, M. R.</p> <p>2016-12-01</p> <p>The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T 2 s in the model compartments, resulting in overestimation of pseudodiffusion <span class="hlt">fraction</span> f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) <span class="hlt">dependence</span> of f, and provides direct compartment T 2 estimates. Two consented healthy volunteer cohorts (n  =  5, 6) underwent DWI comprising multiple TE/b-value combinations (Protocol 1: TE  =  62-102 ms, b  =  0-250 mm-2s, 30 combinations. Protocol 2: 8 b-values 0-800 mm-2s at TE  =  62 ms, with 3 additional b-values 0-50 mm-2s at TE  =  80, 100 ms scanned twice). Data from liver ROIs were fitted with IVIM at individual TEs, and with the T2-IVIM model using all data. Repeat-measures coefficients of variation were assessed for Protocol 2. Conventional IVIM modelling at individual TEs (Protocol 1) demonstrated apparent f increasing with longer TE: 22.4  ±  7% (TE  =  62 ms) to 30.7  ±  11% (TE  =  102 ms) T2-IVIM model fitting accounted for all data variation. Fitting of Protocol 2 data using T2-IVIM yielded reduced f estimates (IVIM: 27.9  ±  6%, T2-IVIM: 18.3  ±  7%), as well as T 2  =  42.1  ±  7 ms, 77.6  ±  30 ms for true and pseudodiffusion compartments, respectively. A reduced Protocol 2 dataset yielded comparable results in a clinical time frame (11 min). The confounding <span class="hlt">dependence</span> of IVIM f on TE can be accounted for using additional b/TE images and the extended T2-IVIM model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27893459','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27893459"><span>Extended T2-IVIM model for correction of TE <span class="hlt">dependence</span> of pseudo-diffusion volume <span class="hlt">fraction</span> in clinical diffusion-weighted magnetic resonance imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jerome, N P; d'Arcy, J A; Feiweier, T; Koh, D-M; Leach, M O; Collins, D J; Orton, M R</p> <p>2016-12-21</p> <p>The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T 2 s in the model compartments, resulting in overestimation of pseudodiffusion <span class="hlt">fraction</span> f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) <span class="hlt">dependence</span> of f, and provides direct compartment T 2 estimates. Two consented healthy volunteer cohorts (n  =  5, 6) underwent DWI comprising multiple TE/b-value combinations (Protocol 1: TE  =  62-102 ms, b  =  0-250 mm(-2)s, 30 combinations. Protocol 2: 8 b-values 0-800 mm(-2)s at TE  =  62 ms, with 3 additional b-values 0-50 mm(-2)s at TE  =  80, 100 ms; scanned twice). Data from liver ROIs were fitted with IVIM at individual TEs, and with the T2-IVIM model using all data. Repeat-measures coefficients of variation were assessed for Protocol 2. Conventional IVIM modelling at individual TEs (Protocol 1) demonstrated apparent f increasing with longer TE: 22.4  ±  7% (TE  =  62 ms) to 30.7  ±  11% (TE  =  102 ms); T2-IVIM model fitting accounted for all data variation. Fitting of Protocol 2 data using T2-IVIM yielded reduced f estimates (IVIM: 27.9  ±  6%, T2-IVIM: 18.3  ±  7%), as well as T 2  =  42.1  ±  7 ms, 77.6  ±  30 ms for true and pseudodiffusion compartments, respectively. A reduced Protocol 2 dataset yielded comparable results in a clinical time frame (11 min). The confounding <span class="hlt">dependence</span> of IVIM f on TE can be accounted for using additional b/TE images and the extended T2-IVIM model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhRvL..81.5153H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhRvL..81.5153H"><span>Surface Structure and Electron Density <span class="hlt">Dependence</span> of Scattered Ne+ Ion <span class="hlt">Fractions</span> from Cd- and S-Terminated CdS\\{0001\\} Surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Houssiau, L.; Rabalais, J. W.; Wolfgang, J.; Nordlander, P.</p> <p>1998-12-01</p> <p>Experimental measurements of the magnitudes and azimuthal anisotropies of 4 keV Ne+ scattered ion <span class="hlt">fractions</span> from both the Cd- and S-terminated surfaces of CdS\\{0001\\} exhibit high sensitivity to both surface structure and electron density. Using a density functional approach, a clear correlation has been demonstrated between these Ne+ ion <span class="hlt">fractions</span> and the lateral variation of the electrostatic potential along the outgoing trajectories of the scattered Ne atoms. The observed anisotropy in the ion <span class="hlt">fractions</span> is a result of the variations in surface to atom electron transfer rates due to tunneling barriers introduced by the electrostatic potentials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15002120','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15002120"><span>Calculation of Shock Hugoniot Curves of Precompressed Liquid <span class="hlt">Deuterium</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Militzer, B</p> <p>2002-11-18</p> <p>Path integral Monte Carlo simulations have been used to study <span class="hlt">deuterium</span> at high pressure and temperature. The equation of state has been derived in the temperature and density region of 10,000 {le} T {le} 1,000,000 and 0.6 {le} {rho} {le} 2.5 g cm{sup -3}. A series of shock Hugoniot curves is computed for different initial compressions in order to compare with current and future shock wave experiments using liquid <span class="hlt">deuterium</span> samples precompressed in diamond anvil cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22591027','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22591027"><span>Gas temperature measurements in <span class="hlt">deuterium</span> hollow cathode glow discharge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Majstorović, Gordana; Šišović, Nikola</p> <p>2016-03-25</p> <p>We report results of optical emission spectroscopy measurements of rotational T{sub rot} and translational (gas) temperature of <span class="hlt">deuterium</span> molecules in a hollow cathode (HC) glow discharge. The rotational temperature of excited electronic state of D{sub 2} was determined from the intensity distribution in the rotational structure of Q branch of the two Fulcher-α diagonal bands: (ν’=ν”=2) and (ν’=ν”=3). The population of excited energy levels, determined from relative line intensities, was used to derive radial rotational temperature distributions as well as gas temperature distribution of <span class="hlt">deuterium</span> molecule.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70010122','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70010122"><span><span class="hlt">Deuterium</span>: Natural variations used as a biological tracer</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gleason, J.D.; Friedman, I.</p> <p>1970-01-01</p> <p>The suggestion is made that isotope tracing be carried out by monitoring the natural variations in <span class="hlt">deuterium</span> concentrations. As an example, the natural variations in <span class="hlt">deuterium</span> concentrations between food and water collected in Illinois and food and water collected in Colorado were used to determine the residence time of water in the blood and urine of rats. We observed not only a 51/2-day turnover time of water in the blood and urine, but also evidence for the influx of water vapor from the atmosphere through the lungs into the blood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10163587','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10163587"><span>Commissioning status of the Continuous Wave <span class="hlt">Deuterium</span> Demonstrator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hartog, P.D.; Dooling, J.; Lorello, M.; Rathke, J.; Carwardine, J.; Godden, D.; Pile, G.; Yule, T.; Zinneman, T.</p> <p>1993-06-01</p> <p>Grumman Aerospace Corporation, Argonne National Laboratory, and Culham Laboratory are commissioning the Continuous Wave <span class="hlt">Deuterium</span> Demonstrator (CWDD) in a facility at Argonne National Laboratory. CWDD is a high-brightness, high-current, 7.5-MeV negative <span class="hlt">deuterium</span> accelerator. The 352-MHz rf accelerating cavities are cryogenically cooled with supercritical neon to reduce the rf power requirements. Installation of the accelerator into the Argonne facility began in May 1991, and first beam from the injector was extracted in February 1992. The accelerator and facility are described, and current status and future plans are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6531875','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6531875"><span>Commissioning status of the Continuous Wave <span class="hlt">Deuterium</span> Demonstrator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hartog, P.D.; Dooling, J.; Lorello, M.; Rathke, J. ); Carwardine, J.; Godden, D.; Pile, G. ); Yule, T.; Zinneman, T. )</p> <p>1993-01-01</p> <p>Grumman Aerospace Corporation, Argonne National Laboratory, and Culham Laboratory are commissioning the Continuous Wave <span class="hlt">Deuterium</span> Demonstrator (CWDD) in a facility at Argonne National Laboratory. CWDD is a high-brightness, high-current, 7.5-MeV negative <span class="hlt">deuterium</span> accelerator. The 352-MHz rf accelerating cavities are cryogenically cooled with supercritical neon to reduce the rf power requirements. Installation of the accelerator into the Argonne facility began in May 1991, and first beam from the injector was extracted in February 1992. The accelerator and facility are described, and current status and future plans are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5019653','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5019653"><span>Synthesis of <span class="hlt">deuterium</span> labeled 17-methyl-testosterone</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shinohara, Y.; Baba, S.; Kasuya, Y.</p> <p>1984-09-01</p> <p>The synthesis of two forms of selectively deuterated 17-methyl-testosterone is described. 17-Methyl-d3-testosterone was prepared by the Grignard reaction of dehydroepiandrosterone with <span class="hlt">deuterium</span> labeled methyl magnesium iodide followed by an Oppenauer oxidation. 17-Methyl-d3-testosterone-19,19,19-d3 was prepared by treating 3,3-ethylenedioxy-5,10-epoxy-5 alpha, 10 alpha-estran-17-one with <span class="hlt">deuterium</span> labeled methyl magnesium bromide followed by hydrolysis and dehydration of the 5 alpha-hydroxyandrostane derivative.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23076183','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23076183"><span>[Research progress of the inhibitory effect of <span class="hlt">deuterium</span>-depleted water on cancers].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Hongqiang; Liu, Cong; Fang, Weiyi; Yang, Huiling</p> <p>2012-10-01</p> <p><span class="hlt">Deuterium</span> is an important predisposing factor for cancer. <span class="hlt">Deuterium</span>-depleted Water, also known as low <span class="hlt">deuterium</span> water, ultra-light water or no <span class="hlt">deuterium</span> water, can be obtained by removing <span class="hlt">deuterium</span> from natural water. Studies have shown that water with a low <span class="hlt">deuterium</span> concentration (<65% percent of volume) can inhibit cancer growth. Clinical trials demonstrated that drinking DDW (10-20 ppm) caused growth arrest of malignant cells in cancer patients and significantly prolonged the patient survival with also improved quality of life. A wide range of anti-cancer drugs in current use are associated with severe adverse effects, while <span class="hlt">deuterium</span>-depleted water appears to have virtually no pharmacological side effects and is convenient to administer. The authors review the advances in the researches of anti-cancer effects and the underlying mechanisms of <span class="hlt">deuterium</span>-depleted water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PlPhR..42...38D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PlPhR..42...38D"><span>Specific features of X-ray generation by plasma focus chambers with <span class="hlt">deuterium</span> and <span class="hlt">deuterium</span>-tritium fillings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dulatov, A. K.; Krapiva, P. S.; Lemeshko, B. D.; Mikhailov, Yu. V.; Moskalenko, I. N.; Prokuratov, I. A.; Selifanov, A. N.</p> <p>2016-01-01</p> <p>The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with <span class="hlt">deuterium</span> and <span class="hlt">deuterium</span>-tritium fillings are determined. In experiments with PF chambers filled with a <span class="hlt">deuterium</span>-tritium mixture, in addition to the HXR pulse with photon energies of up to 200-300 keV, a γ-ray pulse with photon energies of up to 2.5-3.0 MeV is recorded, and a mechanism of its generation is proposed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T41B2571W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T41B2571W"><span>Evidence of the Timing and Rate of Uplift of Central Peruvian Andes from <span class="hlt">Deuterium</span> Isotopes in Volcanic Glass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winton, R.; Saylor, J. E.; Horton, B. K.</p> <p>2013-12-01</p> <p>The uplift history of the Central Andean Plateau (CAP) presents challenges to paleoelevation research with both the rate and timing of uplift debated. Two end-member models have been proposed: 1) gradual surface uplift driven primarily by tectonic shortening (e.g., Barnes and Ehlers, 2009); and 2) rapid uplift in the late Miocene driven primarily by convective removal of dense lower lithosphere (e.g., Garzione et al., 2008). Recently acquired stable isotope and paleotemperature data present a more complex picture of CAP uplift, with multiple spatially and temporally separate uplift pulses (e.g., Quade et al., 2011; Saylor et al., 2012; Leier et al., 2013). In particular, Quade et al. (2011) and Saylor et al. (2012) suggest that the southern and northern CAP may have been uplifted in the early Oligocene and early Miocene, respectively; earlier than the central Altiplano implying an 'edge-to-center' progression of uplift. Determining the rates, timing, and spatial patterns of uplift is hindered by the complex array of factors that influence paleoelevation proxies. While the isotopic composition in rising air masses, precipitation and surface water shows a systematic depletion of 18O and D at higher elevations, this lapse rate may have varied through time due to changes in topography or climate (e.g., Insel et al., 2012). Further complications arise when using carbonates as a proxy record because the <span class="hlt">fractionation</span> factor between surface water and carbonate <span class="hlt">depends</span> on the temperature of crystallization which is, in turn, also <span class="hlt">dependent</span> primarily on elevation. Here we present new <span class="hlt">deuterium</span> isotopic analyses of volcanic glass in the Ayacucho Basin (13.15° S, 74.2° W), central Peru. The Ayacucho Basin is located north of the Altiplano at 2.7-3.7 km elevation, north of the Abancay Deflection. Volcanic glass is well suited for this study because once hydrated, the isotopic composition of the waters of hydration remains distinct from the isotopic composition of modern</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20590323','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20590323"><span><span class="hlt">Fractional</span> dissipative standard map.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tarasov, Vasily E; Edelman, M</p> <p>2010-06-01</p> <p>Using kicked differential equations of motion with derivatives of noninteger orders, we obtain generalizations of the dissipative standard map. The main property of these generalized maps, which are called <span class="hlt">fractional</span> maps, is long-term memory. The memory effect in the <span class="hlt">fractional</span> maps means that their present state of evolution <span class="hlt">depends</span> on all past states with special forms of weights. Already a small deviation of the order of derivative from the integer value corresponding to the regular dissipative standard map (small memory effects) leads to the qualitatively new behavior of the corresponding attractors. The <span class="hlt">fractional</span> dissipative standard maps are used to demonstrate a new type of <span class="hlt">fractional</span> attractors in the wide range of the <span class="hlt">fractional</span> orders of derivatives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title10-vol2/pdf/CFR-2012-title10-vol2-sec110-24.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title10-vol2/pdf/CFR-2012-title10-vol2-sec110-24.pdf"><span>10 CFR 110.24 - General license for the export of <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>... 10 Energy 2 2012-01-01 2012-01-01 false General license for the export of <span class="hlt">deuterium</span>. 110.24... MATERIAL Licenses § 110.24 General license for the export of <span class="hlt">deuterium</span>. (a) A general license is issued to any person to export to any country not listed in § 110.28 or § 110.29 <span class="hlt">deuterium</span> in individual...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol2/pdf/CFR-2011-title10-vol2-sec110-24.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol2/pdf/CFR-2011-title10-vol2-sec110-24.pdf"><span>10 CFR 110.24 - General license for the export of <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... 10 Energy 2 2011-01-01 2011-01-01 false General license for the export of <span class="hlt">deuterium</span>. 110.24... MATERIAL Licenses § 110.24 General license for the export of <span class="hlt">deuterium</span>. (a) A general license is issued to any person to export to any country not listed in § 110.28 or § 110.29 <span class="hlt">deuterium</span> in individual...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title10-vol2/pdf/CFR-2014-title10-vol2-sec110-24.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title10-vol2/pdf/CFR-2014-title10-vol2-sec110-24.pdf"><span>10 CFR 110.24 - General license for the export of <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... 10 Energy 2 2014-01-01 2014-01-01 false General license for the export of <span class="hlt">deuterium</span>. 110.24... MATERIAL Licenses § 110.24 General license for the export of <span class="hlt">deuterium</span>. (a) A general license is issued to any person to export to any country not listed in § 110.28 or § 110.29 <span class="hlt">deuterium</span> in individual...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title10-vol2/pdf/CFR-2013-title10-vol2-sec110-24.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title10-vol2/pdf/CFR-2013-title10-vol2-sec110-24.pdf"><span>10 CFR 110.24 - General license for the export of <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... 10 Energy 2 2013-01-01 2013-01-01 false General license for the export of <span class="hlt">deuterium</span>. 110.24... MATERIAL Licenses § 110.24 General license for the export of <span class="hlt">deuterium</span>. (a) A general license is issued to any person to export to any country not listed in § 110.28 or § 110.29 <span class="hlt">deuterium</span> in individual...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title10-vol2/pdf/CFR-2010-title10-vol2-sec110-24.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title10-vol2/pdf/CFR-2010-title10-vol2-sec110-24.pdf"><span>10 CFR 110.24 - General license for the export of <span class="hlt">deuterium</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 10 Energy 2 2010-01-01 2010-01-01 false General license for the export of <span class="hlt">deuterium</span>. 110.24... MATERIAL Licenses § 110.24 General license for the export of <span class="hlt">deuterium</span>. (a) A general license is issued to any person to export <span class="hlt">deuterium</span> in individual shipments of 10 kilograms or less (50 kilograms of heavy...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NucFu..57d6004Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NucFu..57d6004Z"><span><span class="hlt">Deuterium</span> trapping and surface modification of polycrystalline tungsten exposed to a high-flux plasma at high fluences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zibrov, M.; Balden, M.; Morgan, T. W.; Mayer, M.</p> <p>2017-04-01</p> <p><span class="hlt">Deuterium</span> (D) retention and surface modifications of hot-rolled polycrystalline tungsten (W) exposed to a low-energy (~40 eV D‑1), high-flux (2–5  ×  1023 D m‑2 s‑1) D plasma at temperatures of ~380 K and ~1140 K to fluences up to 1.2  ×  1028 D m‑2 have been examined by using nuclear reaction analysis, thermal desorption spectroscopy, and scanning electron microscopy. The samples exposed at ~380 K exhibited various types of surface modifications: dome-shaped blister-like structures, stepped flat-topped protrusions, and various types of nanostructures. It was observed that a large <span class="hlt">fraction</span> of the surface was covered with blisters and protrusions, but their average size and the number density showed almost no fluence <span class="hlt">dependence</span>. The D depth distributions and total D inventories also barely changed with increasing fluence at ~380 K. A substantial amount of D was retained in the subsurface region, and thickness correlated with the depth where the cavities of blisters and protrusions were located. It is therefore suggested that defects appearing during creation of blisters and protrusions govern the D trapping in the investigated fluence range. In addition, a large number of small cracks was observed on the exposed surfaces, which can serve as fast D release channels towards the surface, resulting in a reduction of the effective D influx into the W bulk. On the samples exposed at ~1140 K no blisters and protrusions were found. However, wave-like and faceted terrace-like structures were formed instead. The concentrations of trapped D were very low (<10‑5 at. fr.) after the exposure at ~1140 K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24328359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24328359"><span>Resolving isotopic fine structure to detect and quantify natural abundance- and hydrogen/<span class="hlt">deuterium</span> exchange-derived isotopomers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Qian; Easterling, Michael L; Agar, Jeffrey N</p> <p>2014-01-07</p> <p>Hydrogen/<span class="hlt">deuterium</span> exchange (HDX) mass spectrometry (MS) is used for analyzing protein dynamics, protein folding/unfolding, and molecular interactions. Until this study, HDX MS experiments employed mass spectral resolving powers that afforded only one peak per nominal mass in a given peptide's isotope distribution, and HDX MS data analysis methods were developed accordingly. A level of complexity that is inherent to HDX MS remained unaddressed, namely, various combinations of natural abundance heavy isotopes and exchanged <span class="hlt">deuterium</span> shared the same nominal mass and overlapped at previous resolving powers. For example, an A + 2 peak is comprised of (among other isotopomers) a two-(2)H-exchanged/zero-(13)C isotopomer, a one-(2)H-exchanged/one-(13)C isotopomer, and a zero-(2)H-exchanged/two-(13)C isotopomer. Notably, such isotopomers differ slightly in mass as a result of the ∼3 mDa mass defect between (2)H and (13)C atoms. Previous HDX MS methods did not resolve these isotopomers, requiring a natural-abundance-only (before HDX or "time zero") spectrum and data processing to remove its contribution. It is demonstrated here that high-resolution mass spectrometry can be used to detect isotopic fine structure, such as in the A + 2 profile example above, deconvolving the isotopomer species resulting from <span class="hlt">deuterium</span> incorporation. Resolving isotopic fine structure during HDX MS therefore permits direct monitoring of HDX, which can be calculated as the sum of the <span class="hlt">fractional</span> peak magnitudes of the <span class="hlt">deuterium</span>-exchanged isotopomers. This obviates both the need for a time zero spectrum as well as data processing to account for natural abundance heavy isotopes, saving instrument and analysis time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19922057','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19922057"><span>Body composition in 10-13-year-old children: a comparison between air displacement plethysmography and <span class="hlt">deuterium</span> dilution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plasqui, G; den Hoed, M; Bonomi, A; Westerterp, K R</p> <p>2009-01-01</p> <p>Air diplacement plethysmography (ADP) has become increasingly popular to assess body composition in children. The aim of this study was to compare ADP with <span class="hlt">deuterium</span> dilution and to investigate the effect of using child-specific prediction equations to correct raw body volume from ADP for thoracic gas volume (TGV) and body surface area (BSA). Thirty-seven healthy Dutch children (17 girls, 20 boys) aged 10-13 years were recruited. Body volume was measured using the Bod Pod. Both adult and child-specific prediction equations were used to correct raw body volume from the Bod Pod for TGV and BSA. Total body water (TBW) was assessed using <span class="hlt">deuterium</span> dilution. Child-specific densities and hydration <span class="hlt">fractions</span> of fat-free mass were used to convert body volume and TBW to percentage fat mass (%FM). Correlation and agreement between methods was assessed using linear regression analysis and Bland-Altman plots. Despite a high correlation between the Bod Pod and <span class="hlt">deuterium</span> dilution (R=0.91, p <0.001), a significant difference was found between %FM obtained using the Bod Pod and <span class="hlt">deuterium</span> dilution (p <0.001), regardless of the equation used to correct raw body volume for TGV and BSA. Bland-Altman plots showed a systematic bias towards a smaller difference between techniques at higher %FM. Significant differences in %FM were found between both methods. Given the underlying assumptions to translate body volume or TBW to %FM, it is recommended to use a 3- or 4-compartment model when assessing body composition in children.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4633821','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4633821"><span>The <span class="hlt">deuterium</span>/hydrogen distribution in chondritic organic matter attests to early ionizing irradiation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Laurent, Boris; Roskosz, Mathieu; Remusat, Laurent; Robert, François; Leroux, Hugues; Vezin, Hervé; Depecker, Christophe; Nuns, Nicolas; Lefebvre, Jean-Marc</p> <p>2015-01-01</p> <p>Primitive carbonaceous chondrites contain a large array of organic compounds dominated by insoluble organic matter (IOM). A striking feature of this IOM is the systematic enrichment in <span class="hlt">deuterium</span> compared with the solar hydrogen reservoir. This enrichment has been taken as a sign of low-temperature ion-molecule or gas-grain reactions. However, the extent to which Solar System processes, especially ionizing radiation, can affect D/H ratios is largely unknown. Here, we report the effects of electron irradiation on the hydrogen isotopic composition of organic precursors containing different functional groups. From an initial terrestrial composition, overall D-enrichments and differential intramolecular <span class="hlt">fractionations</span> comparable with those measured in the Orgueil meteorite were induced. Therefore, ionizing radiation can quantitatively explain the deuteration of organics in some carbonaceous chondrites. For these meteorites, the precursors of the IOM may have had the same isotopic composition as the main water reservoirs of the inner Solar System. PMID:26461170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870047756&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeuterium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870047756&hterms=deuterium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeuterium"><span>Deuterated C3H2 as a clue to <span class="hlt">deuterium</span> chemistry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gerin, M.; Combes, F.; Wootten, H. A.; Boulanger, F.; Peters, W. L., III; Kuiper, T. B. H.</p> <p>1987-01-01</p> <p>The deuterated cyclopropenylidene ring molecule, C3HD, has been detected toward several sources in four rotational lines, at 19, 79, 104, and 107 GHz. The relative integrated intensities of the 2-sub-12 - 1-sub-01 lines of C3HD and C3H2 are found in the ratio 1:5, indicating a high <span class="hlt">deuterium</span> <span class="hlt">fractionation</span> ratio for cyclopropenylidene. The detection of the C-13 isotope of C3H2 at the same position allows a determination of the optical thickness (about 3) of the line. The detection of such a large enhancement in the deuterated form of C3H2 very strongly suggests that a molecular ion is the chemical precursor of the molecules. Consideration of the amount of the enhancement relative to that in other molecules suggests that the precursor ion is C3H3+.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22410440','SCIGOV-STC'); return false;" href="https://www