WorldWideScience

Sample records for 2-h post-ogtt plasma

  1. Clinical significance of 2 h plasma concentrations of first-line anti-tuberculosis drugs

    Prahl, Julie B; Johansen, Isik S; Cohen, Arieh S;

    2014-01-01

    OBJECTIVES: To study 2 h plasma concentrations of the first-line tuberculosis drugs isoniazid, rifampicin, ethambutol and pyrazinamide in a cohort of patients with tuberculosis in Denmark and to determine the relationship between the concentrations and the clinical outcome. METHODS: After 6...... patients. Therapy failure occurred more frequently when the concentrations of isoniazid and rifampicin were both below the normal ranges (P = 0.013) and even more frequently when they were below the median 2 h drug concentrations obtained in the study (P = 0.005). CONCLUSIONS: At 2 h, plasma concentrations...

  2. Optical and electrical study of Ar-C2 H2 and N2-C2 H2 RF-excited plasmas in a small cylindrical reactor

    An optical and electrical investigation were carried out of organic plasmas obtained from DC and RF discharges in mixtures of Arc-C2 H2 in a small cylindrical reactor operating under pressures ranging from 0.3 to 1.0 Torr. The Actinometric Optical Emission Spectroscopy was used to follow the trends of C H and H species in the reactive plasma, for different pressures and power coupled to the reactor. The results showed a decreasing of C H concentration with the increasing of pressure and DC power and an increasing of the H concentration with the increasing of the pressure. The electrical investigation was performed using pulsed Langmuir probe technique, indicating typical electronic temperature around 2 eV. The effects of film deposition on the probe tip surface was analyzed using. Ar as reference gas. The results obtained indicated application of the probe during few period of sweep cycle. (author). 8 refs, 5 figs

  3. Electrical and optical characterization of pulsed plasma of N2 H2

    Martínez, H.; Yousif, F. B.

    2008-03-01

    This paper considers the electrical and optical characterization of glow discharge pulsed plasma in N2/H2 gas mixtures at a pressures range between 0.5 and 4.0 Torr and discharge current between 0.2 and 0.6 A. Electron temperature and ion density measurements were performed employing a double Langmuir probe. They were found to increase rapidly as the H2 percentage in the mixture was increased up to 20%. This increase slows down as the H2 percentage in the gas mixture was increased above 20% at the same pressure. Emission spectroscopy was employed to observe emission from the pulsed plasma of a steady-state electric discharge. The discharge mainly emits within the range 280 500 nm. The emission consists of N2 (C-X) 316, 336, 358 nm narrow peaks and a broad band with a maximum at λmax = 427 nm. Also lines of N2, N2 + and NH excited states were observed. All lines and bands have their maximum intensity at the discharge current of 0.417 A. The intensities of the main bands and spectral lines are determined as functions of the total pressure and discharge current. Agreement with other theoretical and experimental groups was established.

  4. Plasma-catalytic Selective Reduction of NO with C2H4 in the Presence of Excess Oxygen

    Qi SUN; Ai Min ZHU; Xue Feng YANG; Jin Hai NIU; Yong XU; Zhi Min SONG; Jing LIU

    2005-01-01

    This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at250 ℃ in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor.With the reactant gas mixture of 530 ppm NO, 650 ppm C2H4, 5.8% O2 in N2and GHSV = 12000h-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasmacatalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.

  5. Preparation of hydrogenated diamond-like carbon films using high-density pulsed plasmas of Ar/C2H2 and Ne/C2H2 mixture

    Kimura, Takashi; Kamata, Hikaru

    2016-07-01

    Hydrogenated diamond-like carbon films are prepared using reactive high-density pulsed plasmas of Ar/C2H2 and Ne/C2H2 mixture in the total pressure range from 0.5 to 2 Pa. The plasmas are produced using a reactive high-power impulse magnetron sputtering (HiPIMS) system. A negative pulse voltage of ‑500 V is applied to the substrate for a period of 15 µs in the afterglow mode. The growth rate does not strongly depend on the type of ambient gas but it markedly increases to about 2.7 µm/h at a C2H2 fraction of 10% and a total pressure of 2 Pa with increasing C2H2 fraction. The marked increase in the growth rate means that the HiPIMS system can be regarded as a plasma source for the chemical vapor deposition process. The hardness of the films prepared by Ne/C2H2 plasmas is somewhat higher than that of the films prepared by Ar/C2H2 plasmas under the same operating conditions, and the difference becomes larger as the pressure increases. The hardness of the films prepared by Ne/C2H2 plasmas ranges between 11 and 18 GPa. In the Raman spectra, two very broad overlapping bands are assigned as the G (graphite) and D (disorder) bands. The peak position of the G band is roughly independent of the total pressure, whereas the FWHM of the G peak decreases with increasing total pressure as a whole.

  6. Controlled modification of mono- and bilayer graphene in O2, H2 and CF4 plasmas

    In this work, covalent modification of mono- and bilayer graphene is achieved using tetrafluoromethane (CF4), oxygen and hydrogen RF plasma. Controlled modification of graphene is usually difficult to achieve, in particular with oxygen plasma, which is rather aggressive and usually leads to etching of graphene. Here we use x-ray photoelectron spectroscopy and Raman spectroscopy to show that mild plasma conditions and fine tuning of the number of functional groups can be obtained in all plasmas by varying parameters such as exposure time and sample position inside the chamber. We found that even for the usual harsh oxygen treatment the defect density could be lowered, down to one defect for 3.5 × 104 carbon atoms. Furthermore, we show that CF4 plasma leads to functionalization without etching and that graphene becomes an insulator at saturation coverage. In addition, the reactivity of mono- and bilayer graphene was studied revealing faster modification of monolayer in oxygen and CF4 plasma, in agreement with previous works. In contrast, similar modification rates were observed for both mono- and bilayer during hydrogenation. We attribute this discrepancy to the presence of more energetic species in the hydrogen plasma such as positive ions that could play a role in the functionalization process. (paper)

  7. Inductively coupled plasma etching of chemical-vapor-deposited amorphous carbon in N2/H2/Ar chemistries

    In this study, we investigated the etching characteristics and the mechanism of an amorphous carbon (a-C) layer for a multi-level resist (MLR) structure. CVD (chemical-vapor-deposited) a-C layers with a SiO2 hard-mask were etched in an ICP (inductively coupled plasma) etcher while varying the process parameters, such as the top electrode power, the bottom electrode power, and the gas flow ratio in the N2/H2/Ar plasma. The results indicated that the etch rate and the profile angle of the CVD a-C increased with increasing H2 gas flow ratio in the N2/H2/Ar plasma. As the H2 flow ratio increased, the etch rate and the profile angle increase, due to the increased formation of H radicals in the plasma, leading to enhanced chemical reactions with carbon atoms. Also, the etch rate of the CVD a-C increased with increasing top and bottom electrode powers.

  8. Plasma chemistry and diagnostic in an ArN2H2 microwave expanding plasma used for nitriding treatments

    Touimi, Said; Jauberteau, Jean-Louis; Jauberteau, Isabelle; Aubreton, Jacques

    2010-01-01

    Abstract This paper reports on mass spectrometry analysis performed downstream a microwave discharge in Ar-N 2 -H 2 gas mixture in nitriding conditions. Investigations are focused on the main simple radicals NH 2, NH and N, and on the molecular species NH 3 and N 2 H 2 produced. Because of wall desorptions due to catalytic effects, we must develop a specific method taking into account both wall desorption and dissociative ionization effects, in order to correct the mass spectrometer signal...

  9. Ammonia formation in N2/H2 plasmas on ITER-relevant plasma facing materials: Surface temperature and N2 plasma content effects

    Ammonia production in N2/H2 direct current glow discharge plasmas, with nitrogen concentrations from 1.5% to 33%, different wall materials (tungsten, stainless steel and aluminium as a proxy for beryllium) and surface temperatures up to 350 °C has been investigated. Ammonia yields on the exposed materials have been deduced, resulting in different values depending on the wall material, its temperature and N2 plasma content. The results indicate weak wall temperature dependence in tungsten and stainless steel. However, wall temperatures above 300 °C have a very clear influence on aluminium walls, as almost all the molecular N2 depleted from the gas phase is converted into ammonia. The amount of implanted N seems to have a direct impact on the ammonia formation yield, pointing to the competition between N implantation and N/H–N/N recombination on the walls as the key mechanism of the ammonia formation

  10. Properties of Cr(C,N) hard coatings deposited in Ar-C2H2-N2 plasma

    Several chromium carbonitride (Cr-(C,N)) coatings were prepared with different C:N ratios by varying the N2 and C2H2 flow. Chromium nitride (Cr-N) and chromium carbide (Cr-C) coatings were also prepared for comparison. The coatings were deposited in two different ion-plating systems: by reactive evaporation in BAI730M (Balzers) apparatus at high temperature (450 deg. C) and by reactive sputtering in plasma-beam Sputron (Balzers) apparatus at low temperature (200 deg. C). Among mechanical properties microhardness, adhesion (measured by scratch test) and surface roughness were evaluated. Oxidation of the coatings was carried out by heating the samples at temperatures of 750-900 deg. C in an oxygen atmosphere. Crystal structure and microstructure were studied by XRD, TEM and SEM. Chemical State of the elements was observed by XPS. The concentration and depth profiles of the samples oxidized at various temperatures were measured by AES, EDX and GDOES

  11. Detailed study of the plasma-activated catalytic generation of ammonia in N2-H2 plasmas

    van Helden, J. H.; Wagemans, W.; Yagci, G.; Zijlmans, R. A. B.; Schram, D. C.; Engeln, R.; Lombardi, G.; Stancu, G. D.; Röpcke, J.

    2007-02-01

    We investigated the efficiency and formation mechanism of ammonia generation in recombining plasmas generated from mixtures of N2 and H2 under various plasma conditions. In contrast to the Haber-Bosch process, in which the molecules are dissociated on a catalytic surface, under these plasma conditions the precursor molecules, N2 and H2, are already dissociated in the gas phase. Surfaces are thus exposed to large fluxes of atomic N and H radicals. The ammonia production turns out to be strongly dependent on the fluxes of atomic N and H radicals to the surface. By optimizing the atomic N and H fluxes to the surface using an atomic nitrogen and hydrogen source ammonia can be formed efficiently, i.e., more than 10% of the total background pressure is measured to be ammonia. The results obtained show a strong similarity with results reported in literature, which were explained by the production of ammonia at the surface by stepwise addition reactions between adsorbed nitrogen and hydrogen containing radicals at the surface and incoming N and H containing radicals. Furthermore, our results indicate that the ammonia production is independent of wall material. The high fluxes of N and H radicals in our experiments result in a passivated surface, and the actual chemistry, leading to the formation of ammonia, takes place in an additional layer on top of this passivated surface.

  12. Spectroscopic study of H2 microwave plasmas with small admixtures of CH4 and B2H6 used for doped diamond deposition

    Microwave (MW) H2 plasmas with small admixtures of CH4 and/or B2H6 used for doped diamond deposition have been studied by infrared absorption and optical emission spectroscopy (OES) techniques. The experiments were carried out in order to analyze the dependence of the plasma chemistry on several parameters in the MW discharges, such as power, pressure and gas mixture, at relatively high pressures, i.e. up to 300 mbar, and power values, i.e. up to 4 kW. The evolution of the concentrations of five stable molecules, CH4, C2H2, C2H4, C2H6 and B2H6, was monitored in the plasma processes by in situ infrared tunable diode laser absorption spectroscopy. OES was used simultaneously to gather complementary information about the concentration of the boron atom. One target was the determination of the precursors' fragmentation rates and the conversion rates to the molecular reaction products. The analysis of correlations between the power and pressure of the plasma and molecular concentrations, and the differences found with CH4 and B2H6 admixtures were another focus of interest. The degree of dissociation of the carbon containing precursor molecule CH4 varied between 35% and 75%, while the decomposition of diborane, the boron precursor, varied between 85% and 97%. By analyzing the development of the molecular concentrations with changes of gas mixtures, pressure and plasma power values, it was found that (i) C2H2 is the most abundant reaction product in the plasma in the case of methane admixture and (ii) the boron atom concentration depends strongly on the presence of hydrocarbons in the plasma. The fragmentation efficiencies of methane and of diborane (RF(CH4) ≈ (1–2) × 1015 molecules J−1, RF(B2H6) ≈ (0.4–1.4) × 1013 molecules J−1) and the conversion efficiencies to the molecular products (RC(product) ≈ 1013–1015 molecules J−1) have been determined for different gas mixtures and plasma power, and pressure values. The boron atom

  13. Spectroscopic study of H2 microwave plasmas with small admixtures of CH4 and B2H6 used for doped diamond deposition

    Hamann, S.; Rond, C.; Pipa, A. V.; Wartel, M.; Lombardi, G.; Gicquel, A.; Röpcke, J.

    2014-08-01

    Microwave (MW) H2 plasmas with small admixtures of CH4 and/or B2H6 used for doped diamond deposition have been studied by infrared absorption and optical emission spectroscopy (OES) techniques. The experiments were carried out in order to analyze the dependence of the plasma chemistry on several parameters in the MW discharges, such as power, pressure and gas mixture, at relatively high pressures, i.e. up to 300 mbar, and power values, i.e. up to 4 kW. The evolution of the concentrations of five stable molecules, CH4, C2H2, C2H4, C2H6 and B2H6, was monitored in the plasma processes by in situ infrared tunable diode laser absorption spectroscopy. OES was used simultaneously to gather complementary information about the concentration of the boron atom. One target was the determination of the precursors' fragmentation rates and the conversion rates to the molecular reaction products. The analysis of correlations between the power and pressure of the plasma and molecular concentrations, and the differences found with CH4 and B2H6 admixtures were another focus of interest. The degree of dissociation of the carbon containing precursor molecule CH4 varied between 35% and 75%, while the decomposition of diborane, the boron precursor, varied between 85% and 97%. By analyzing the development of the molecular concentrations with changes of gas mixtures, pressure and plasma power values, it was found that (i) C2H2 is the most abundant reaction product in the plasma in the case of methane admixture and (ii) the boron atom concentration depends strongly on the presence of hydrocarbons in the plasma. The fragmentation efficiencies of methane and of diborane (RF(CH4) ≈ (1-2) × 1015 molecules J-1, RF(B2H6) ≈ (0.4-1.4) × 1013 molecules J-1) and the conversion efficiencies to the molecular products (RC(product) ≈ 1013-1015 molecules J-1) have been determined for different gas mixtures and plasma power, and pressure values. The boron atom balance, in relation to the

  14. Growth Conditions and Cell Cycle Phase Modulate Phase Transition Temperatures in RBL-2H3 Derived Plasma Membrane Vesicles.

    Erin M Gray

    Full Text Available Giant plasma membrane vesicle (GPMV isolated from a flask of RBL-2H3 cells appear uniform at physiological temperatures and contain coexisting liquid-ordered and liquid-disordered phases at low temperatures. While a single GPMV transitions between these two states at a well-defined temperature, there is significant vesicle-to-vesicle heterogeneity in a single preparation of cells, and average transition temperatures can vary significantly between preparations. In this study, we explore how GPMV transition temperatures depend on growth conditions, and find that average transition temperatures are negatively correlated with average cell density over 15°C in transition temperature and nearly three orders of magnitude in average surface density. In addition, average transition temperatures are reduced by close to 10°C when GPMVs are isolated from cells starved of serum overnight, and elevated transition temperatures are restored when serum-starved cells are incubated in serum-containing media for 12 h. We also investigated variation in transition temperature of GPMVs isolated from cells synchronized at the G1/S border through a double Thymidine block and find that average transition temperatures are systematically higher in GPMVs produced from G1 or M phase cells than in GPMVs prepared from S or G1 phase cells. Reduced miscibility transition temperatures are also observed in GPMVs prepared from cells treated with TRAIL to induce apoptosis or sphingomyelinase, and in some cases a gel phase is observed at temperatures above the miscibility transition in these vesicles. We conclude that at least some variability in GPMV transition temperature arises from variation in the local density of cells and asynchrony of the cell cycle. It is hypothesized that GPMV transition temperatures are a proxy for the magnitude of lipid-mediated membrane heterogeneity in intact cell plasma membranes at growth temperatures. If so, these results suggest that cells tune

  15. The quenching effect of hydrogen on the nitrogen in metastable state in atmospheric-pressure N2-H2 microwave plasma torch

    The atmospheric-pressure microwave N2-H2 plasma torch is generated and diagnosed by optical emission spectroscopy. It is found that a large amount of N atoms and NH radicals are generated in the plasma torch and the emission intensity of N2+ first negative band is the strongest over the spectra. The mixture of hydrogen in nitrogen plasma torch causes the morphology of the plasma discharge to change with appearance that the afterglow shrinks greatly and the emission intensity of N2+ first negative band decreases with more hydrogen mixed into nitrogen plasma. In atmospheric-pressure microwave-induced plasma torch, the hydrogen imposes a great influence on the characteristics of nitrogen plasma through the quenching effect of the hydrogen on the metastable state of N2

  16. Etching of low-k materials for microelectronics applications by means of a N2/H2 plasma: modeling and experimental investigation

    In this paper, we investigate the etch process of so-called low-k organic material by means of a N2/H2 capacitively coupled plasma, as applied in the micro-electronics industry for the manufacturing of computer chips. In recent years, such an organic material has emerged as a possible alternative for replacing bulk SiO2 as a dielectric material in the back-end-of-line, because of the smaller parasitic capacity between adjacent conducting lines, and thus a faster propagation of the electrical signals throughout the chip. Numerical simulations with a hybrid plasma model, using an extensive plasma and surface chemistry set, as well as experiments are performed, focusing on the plasma properties as well as the actual etching process, to obtain a better insight into the underlying mechanisms. Furthermore, the effects of gas pressure, applied power and gas composition are investigated to try to optimize the etch process. In general, the plasma density reaches a maximum near the wafer edge due to the so-called ‘edge effect’. As a result, the etch rate is not uniform but will also reach its maximum near the wafer edge. The pressure seems not to have a big effect. A higher power increases the etch rate, but the uniformity becomes (slightly) worse. The gas mixing ratio has no significant effect on the etch process, except when a pure H2 or N2 plasma is used, illustrating the synergistic effects of a N2/H2 plasma. In fact, our calculations reveal that the N2/H2 plasma entails an ion-enhanced etch process. The simulation results are in reasonable agreement with the experimental values. The microscopic etch profile shows the desired anisotropic shape under all conditions under study. (paper)

  17. Effects of hBN Content on the Microstructure and Properties of Atmospheric Plasma-Sprayed NiCr/Cr3C2-hBN Composite Coatings

    Cao, Yuxia

    2016-04-01

    NiCr/Cr3C2-hBN composite coatings with different contents of hBN were prepared by atmospheric plasma-spray technology. The microstructural, mechanical, and tribological properties of the coatings were systematically investigated. The results show that the flowability and apparent density of NiCr/Cr3C2-hBN composite powders, as well as the microhardness and tensile strength of the NiCr/Cr3C2-hBN composite coating, gradually decrease with the increase of hBN in the composite powders. The addition of hBN is benefit to the friction coefficient of the coatings, but it is positive to the wear rate. When the content of hBN is up to 20%, the friction coefficient of the composite coating is lowest, but the wear rate of the composite coating is highest.

  18. PMP1 18-38, a yeast plasma membrane protein fragment, binds phosphatidylserine from bilayer mixtures with phosphatidylcholine: a (2)H-NMR study.

    M. Roux; Beswick, V; Coïc, Y M; Huynh-Dinh, T.; Sanson, A.; Neumann, J M

    2000-01-01

    PMP1 is a 38-residue plasma membrane protein of the yeast Saccharomyces cerevisiae that regulates the activity of the H(+)-ATPase. The cytoplasmic domain conformation results in a specific interfacial distribution of five basic side chains, thought to strongly interact with anionic phospholipids. We have used the PMP1 18-38 fragment to carry out a deuterium nuclear magnetic resonance ((2)H-NMR) study for investigating the interactions between the PMP1 cytoplasmic domain and phosphatidylserine...

  19. HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers

    Soulimane, Soraya; Simon, Dominique; Herman, William H;

    2014-01-01

    without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random.......09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower...... as screened by 2H-PG, in comparison with never-smokers. CONCLUSION/INTERPRETATION: Across this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes....

  20. Generation and loss of reactive oxygen species in low-temperature atmospheric-pressure RF He + O2 + H2O plasmas

    This study focuses on the generation and loss of reactive oxygen species (ROS) in low-temperature atmospheric-pressure RF (13.56 MHz) He + O2 + H2O plasmas, which are of interest for many biomedical applications. These plasmas create cocktails of ROS containing ozone, singlet oxygen, atomic oxygen, hydroxyl radicals, hydrogen peroxide and hydroperoxyl radicals, i.e. ROS of great significance as recognized by the free-radical biology community. By means of one-dimensional fluid simulations (61 species, 878 reactions), the key ROS and their generation and loss mechanisms are identified as a function of the oxygen and water content in the feed gas. Identification of the main chemical pathways can guide the optimization of He + O2 + H2O plasmas for the production of particular ROS. It is found that for a given oxygen concentration, the presence of water in the feed gas decreases the net production of oxygen-derived ROS, while for a given water concentration, the presence of oxygen enhances the net production of water-derived ROS. Although most ROS can be generated in a wide range of oxygen and water admixtures, the chemical pathways leading to their generation change significantly as a function of the feed gas composition. Therefore, care must be taken when selecting reduced chemical sets to study these plasmas. (fast track communication)

  1. Comparative sterilization effectiveness of plasma in O2-H2O2 mixtures and ethylene oxide treatment.

    Silva, J M F; Moreira, A J; Oliveira, D C; Bonato, C B; Mansano, R D; Pinto, T J A

    2007-01-01

    We investigated the influence of variable parameters of plasma sterilization and compared its effectiveness with that of ethylene oxide using a reactive ion etching plasma reactor at 13.56 MHz. Gases tested were pure oxygen and oxygen-hydrogen peroxide mixtures in 190/10, 180/20, and 160/40 sccm ratios with constant gas flow at 200 sccm, pressure at 0.100 torr, radio-frequency power at 25 W, 50 W, 100 W, and 150 W, and temperature below 60 degrees C. Ethylene oxide sterilization was performed using 450 mg/L at 55 degrees C, 60% humidity, and -0.65 and 0.60 kgf/cm2 pressure. The biological indicator was Bacillus atrophaeus ATCC 9372, with exposure times of 3 to 120 min. Observed D values were 215.91, 55.55, 9.19, and 2.98 min for pure oxygen plasma at 25 W, 50 W, 100 W, and 150 W, respectively. Oxygen-hydrogen peroxide plasma produced D values of 6.41 min (190/10), 6.47 min (180/20), and 4.02 min (160/40) at 100 W and 1.47 min (190/10), 3.11 min (180/20), and 1.94 min (160/40) at 150 W. Ethylene oxide processes resulted in a D value of 2.86 min. Scanning electron microscopy analyses showed damage to the spore cortex. PMID:17722487

  2. Investigation of laser-plasma chemistry in CO-N-2-H2O mixtures using O-18 labeled water

    Ferus, Martin; Matulková, Irena; Juha, Libor; Civiš, Svatopluk

    2009-01-01

    Roč. 472, 1-3 (2009), s. 14-18. ISSN 0009-2614 R&D Projects: GA ČR GA203/06/1278; GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100523 Keywords : carbon monoxide * plasma * atmosphere Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.291, year: 2009

  3. Investigation of Laser Plasma Chemistry in CO2-N-2-H2O Using O-18 Labeled Water

    Ferus, Martin; Kubelík, Petr; Juha, Libor; Civiš, Svatopluk

    2009-01-01

    Roč. 39, 3-4 (2009), s. 245-245. ISSN 0169-6149 R&D Projects: GA MŠk LC510; GA MŠk(CZ) LC528; GA ČR GA203/06/1278; GA MŠk LA08024 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100523 Keywords : LIDB plasma * atmosphere * isotopes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.053, year: 2009

  4. Key insights into the reacting kinetics of atmospheric pressure plasmas using He +N2 /O2 /CO2 /H2 O/Air mixtures

    Murakami, Tomoyuki

    2015-09-01

    A zero dimensional kinetic chemistry computational modeling to identify the important collisional mechanisms and the dominant species in atmospheric pressure plasmas has been developed. This modeling provides an enhanced capability to tailor wide variety of reactive intermediates/species in atmospheric pressure plasmas using He +N2 /O2 /CO2 /H2 O/Air mixtures. The influence of the gas constituent, the gas temperature and the excitation frequency (kHz-, RF-, Pulsed-working) on the complex reacting chemical kinetics is clarified. This work also focuses on the benchmarking between the predictive outputs of this computer-based simulations and the diverse experimental diagnostics with particular emphasis on reactive oxygen/nitrogen intermediates/species. This work was partly supported by KAKENHI Grant Number 24561054.

  5. Ca2+ pump and Ca2+/H+ antiporter in plasma membrane vesicles isolated by aqueous two-phase partitioning from corn leaves

    Plasma membrane vesicles, which are mostly right side-out, were isolated from corn leaves by aqueous two-phase partitioning method. Characteristics of Ca2+ transport were investigated after preparing inside-out vesicles by Triton X-100 treatment. 45Ca2+ transport was assayed by membrane filtration technique. Results showed that Ca2+ transport into the plasma membrane vesicles was Mg-ATP dependent. The active Ca2+ transport system had a high affinity for Ca2+(Km(Ca2+) = 0.4 microM) and ATP(Km(ATP) = 3.9 microM), and showed pH optimum at 7.5. ATP-dependent Ca2+ uptake in the plasma membrane vesicles was stimulated in the presence of Cl- or NO3-. Quenching of quinacrine fluorescence showed that these anions also induced H+ transport into the vesicles. The Ca2+ uptake stimulated by Cl- was dependent on the activity of H+ transport into the vesicles. However, carbonylcyanide m-chlorophenylhydrazone (CCCP) and VO4(3-) which is known to inhibit the H+ pump associated with the plasma membrane, canceled almost all of the Cl(-)-stimulated Ca2+ uptake. Furthermore, artificially imposed pH gradient (acid inside) caused Ca2+ uptake into the vesicles. These results suggest that the Cl(-)-stimulated Ca2+ uptake is caused by the efflux of H+ from the vesicles by the operation of Ca2+/H+ antiport system in the plasma membrane. In Cl(-)-free medium, H+ transport into the vesicles scarcely occurred and the addition of CCCP caused only a slight inhibition of the active Ca2+ uptake into the vesicles. These results suggest that two Ca2+ transport systems are operating in the plasma membrane from corn leaves, i.e., one is an ATP-dependent active Ca2+ transport system (Ca2+ pump) and the other is a Ca2+/H+ antiport system. Little difference in characteristics of Ca2+ transport was observed between the plasma membranes isolated from etiolated and green corn leaves

  6. Bandgap measurements and the peculiar splitting of E2H phonon modes of InxAl1-xN nanowires grown by plasma assisted molecular beam epitaxy

    Tangi, Malleswararao

    2016-07-26

    The dislocation free Inx Al 1-xN nanowires (NWs) are grown on Si(111) by nitrogen plasma assisted molecular beam epitaxy in the temperature regime of 490 °C–610 °C yielding In composition ranges over 0.50 ≤ x ≤ 0.17. We study the optical properties of these NWs by spectroscopic ellipsometry (SE), photoluminescence, and Raman spectroscopies since they possesses minimal strain with reduced defects comparative to the planar films. The optical bandgap measurements of Inx Al 1-xN NWs are demonstrated by SE where the absorption edges of the NW samples are evaluated irrespective of substrate transparency. A systematic Stoke shift of 0.04–0.27 eV with increasing x was observed when comparing the micro-photoluminescence spectra with the Tauc plot derived from SE. The micro-Raman spectra in the NWs with x = 0.5 showed two-mode behavior for A1(LO) phonons and single mode behavior for E2 H phonons. As for x = 0.17, i.e., high Al content, we observed a peculiar E2 H phonon mode splitting. Further, we observe composition dependent frequency shifts. The 77 to 600 K micro-Raman spectroscopy measurements show that both AlN- and InN-like modes of A1(LO) and E2 H phonons in Inx Al 1-xN NWs are redshifted with increasing temperature, similar to that of the binary III group nitride semiconductors. These studies of the optical properties of the technologically important Inx Al 1-xN nanowires will path the way towards lasers and light-emitting diodes in the wavelength of the ultra-violet and visible range.

  7. Lipon thin films grown by plasma-enhanced metalorganic chemical vapor deposition in a N{sub 2}-H{sub 2}-Ar gas mixture

    Meda, Lamartine, E-mail: LMeda@xula.edu [Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA, 70125 (United States); Maxie, Eleston E. [Excellatron Solid State LLC, 263 Decatur Street, Atlanta, GA 30312 (United States)

    2012-01-01

    Lithium phosphorus oxynitride (Lipon) thin films have been deposited by a plasma-enhanced metalorganic chemical vapor deposition method. Lipon thin films were deposited on approximately 0.2 {mu}m thick Au-coated alumina substrates in a N{sub 2}-H{sub 2}-Ar plasma at 13.56 MHz, a power of 150 W, and at 180 Degree-Sign C using triethyl phosphate [(CH{sub 2}CH{sub 3}){sub 3}PO{sub 4}] and lithium tert-butoxide [(LiOC(CH{sub 3}){sub 3}] precursors. Lipon growth rates ranged from 10 to 42 nm/min and thicknesses varied from 1 to 2.5 {mu}m. X-ray powder diffraction showed that the films were amorphous, and X-ray photoelectron spectroscopy (XPS) revealed approximately 4 at.% N in the films. The ionic conductivity of Lipon was measured by electrochemical impedance spectroscopy to be approximately 1.02 {mu}S/cm, which is consistent with the ionic conductivity of Lipon deposited by radio frequency magnetron sputtering of Li{sub 3}PO{sub 4} targets in either mixed Ar-N{sub 2} or pure N{sub 2} atmosphere. Attempts to deposit Lipon in a N{sub 2}-O{sub 2}-Ar plasma resulted in the growth of Li{sub 3}PO{sub 4} thin films. The XPS analysis shows no C and N atom peaks. Due to the high impedance of these films, reliable conductivity measurements could not be obtained for films grown in N{sub 2}-O{sub 2}-Ar plasma.

  8. Highly selective etching of silicon nitride to physical-vapor-deposited a-C mask in dual-frequency capacitively coupled CH2F2/H2 plasmas

    A multilevel resist (MLR) structure can be fabricated based on a very thin amorphous carbon (a-C) layer ( congruent with 80 nm) and Si3N4 hard-mask layer ( congruent with 300 nm). The authors investigated the selective etching of the Si3N4 layer using a physical-vapor-deposited (PVD) a-C mask in a dual-frequency superimposed capacitively coupled plasma etcher by varying the process parameters in the CH2F2/H2/Ar plasmas, viz., the etch gas flow ratio, high-frequency source power (PHF), and low-frequency source power (PLF). They found that under certain etch conditions they obtain infinitely high etch selectivities of the Si3N4 layers to the PVD a-C on both the blanket and patterned wafers. The etch gas flow ratio played a critical role in determining the process window for infinitely high Si3N4/PVD a-C etch selectivity because of the change in the degree of polymerization. The etch results of a patterned ArF photoresisit/bottom antireflective coating/SiOx/PVD a-C/Si3N4 MLR structure supported the idea of using a very thin PVD a-C layer as an etch-mask layer for the Si3N4 hard-mask pattern with a pattern width of congruent with 80 nm and high aspect ratio of congruent with 5.

  9. Carbon Nitride Thin Films Deposited by Plasma Assisted Nd∶YAG Laser Ablation of Graphite in N2+H2 Atmosphere

    YU Wei; WANG Shufang; ZHANG Lianshui; LI Xiaowei; FU Guangsheng

    2001-01-01

    Carbon nitride thin films are deposited on silicon wafers by 532 nm Nd∶YAG laser ablation of graphite in the N2+H2 atmosphere assisted by a dc glow discharge plasma at a higher gas pressure of about 4.0 kPa. The properties of the thin films are investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The results show that the deposited films are composed of α-C3N4, β-C3N4 phase and have the N/C atomic ratio of 2.01. The optical emission spectroscopy (OES) studies indicate that the introduction of a dc glow discharge and the adoption of a higher gas pressure during the film deposition are favorable to the net generation of the atomic N, CN radicals and N+2 in B2Σ+u excited state in the plasma, which are considered to play a major role in the synthesis of carbon nitride.

  10. Ammonia formation in N{sub 2}/H{sub 2} plasmas on ITER-relevant plasma facing materials: Surface temperature and N{sub 2} plasma content effects

    Castro, A. de, E-mail: alfonso.decastro@ciemat.es; Alegre, D.; Tabarés, F.L.

    2015-08-15

    Ammonia production in N{sub 2}/H{sub 2} direct current glow discharge plasmas, with nitrogen concentrations from 1.5% to 33%, different wall materials (tungsten, stainless steel and aluminium as a proxy for beryllium) and surface temperatures up to 350 °C has been investigated. Ammonia yields on the exposed materials have been deduced, resulting in different values depending on the wall material, its temperature and N{sub 2} plasma content. The results indicate weak wall temperature dependence in tungsten and stainless steel. However, wall temperatures above 300 °C have a very clear influence on aluminium walls, as almost all the molecular N{sub 2} depleted from the gas phase is converted into ammonia. The amount of implanted N seems to have a direct impact on the ammonia formation yield, pointing to the competition between N implantation and N/H–N/N recombination on the walls as the key mechanism of the ammonia formation.

  11. Sex differences in glucose levels

    Faerch, K; Borch-Johnsen, Knut; Vaag, A;

    2010-01-01

    We aimed to examine whether sex differences in fasting plasma glucose (FPG), 2 h post-OGTT plasma glucose (2hPG) and HbA(1c) could be explained by differences in body size and/or body composition between men and women in a general non-diabetic Danish population. Moreover, we aimed to study to what...

  12. Quantum cascade laser investigations of CH4 and C2H2 interconversion in hydrocarbon/H2 gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond

    CH4 and C2H2 molecules (and their interconversion) in hydrocarbon/rare gas/H2 gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm-1 using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H2 plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH4 and C2H2 molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH4 and C2H2. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH4→C2H2 conversion occurs most efficiently in an annular shell around the central plasma (characterized by 1400gas2H2→CH4 is favored in the more distant regions where Tgas4→C2H2 conversion, whereas the reverse C2H2→CH4 process only requires H atoms to drive the reactions; H atoms are not consumed by the overall conversion.

  13. Surface reactivity of molybdenum thin films exposed to (Ar-N{sub 2}-H{sub 2}) expanding microwave plasma at low temperature: influence of the addition of H{sub 2} gas in the plasma

    Jauberteau, I [UMR 6638 CNRS, SPCTS, Faculte des Sciences et Techniques, F-87060 Limoges cedex (France); Jauberteau, J L [UMR 6638 CNRS, SPCTS, Faculte des Sciences et Techniques, F-87060 Limoges cedex (France); Cahoreau, M [UMR 6630 CNRS, SP2MI, UFR des Sciences, Bd3, Teleport 2, BP 179, F-86960 Futuroscope (France); Aubreton, J [UMR 6638 CNRS, SPCTS, Faculte des Sciences et Techniques, F-87060 Limoges cedex (France)

    2005-10-07

    The rapid transfer of a large amount of nitrogen into the surface layers followed by diffusion into the inner layers occurs in thin molybdenum films exposed to expanding microwave plasma using (Ar-35%N{sub 2}) and (Ar-25%N{sub 2}-30%H{sub 2}) gas mixtures. The nitrogen transfer into the surface layers nearly correlates to a Gaussian distribution law, which is explained by the formation of a large number of defects at the film surface in which nitrogen piles up before diffusing into the inner metal layers. Such an effect could be induced by the impinging energetic plasma species as ions, NH{sub x<3} radicals. The diffusion part is successfully fitted to Fick's second law by introducing diffusion coefficients of about (5-7) x 10{sup -14} cm{sup 2} s{sup -1} at 673 K. These values are lower than the diffusion coefficient calculated for a solid solution of nitrogen in molybdenum which is equal to about 4 x 10{sup -13} cm{sup 2} s{sup -1}. A surprisingly high diffusion coefficient of about 3 x 10{sup -13} cm{sup 2} s{sup -1} is found for the molybdenum film exposed to (Ar-25%N{sub 2}-30%H{sub 2}) plasma at room temperature. These results highlight the role of plasma hydrogen species on the enhancement of the metal surface reactivity and nitrogen diffusion into the inner metal layers. A modification of the morphology of the film surface exposed to hydrogen species is also seen. The values of electron densities measured in the various (Ar-N{sub 2}-H{sub 2}) gas mixtures are consistent with the formation of expanded plasma far from the centre of the discharge, apart from(Ar-30%N{sub 2}-12%H{sub 2}) where the plasma expansion is very low. At a distance of 10.5 cm from the centre of the discharge, the electron density is equal to about 1.66 x 10{sup 17} m{sup -3} and 1.16 x 10{sup 17} m{sup -3} for (Ar-25%N{sub 2}-30%H{sub 2}) and (Ar-35%N{sub 2}) gas mixtures, respectively.

  14. Quantum cascade laser investigations of CH4 and C2H2 interconversion in hydrocarbon/H2 gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond

    Ma, Jie; Cheesman, Andrew; Ashfold, Michael N. R.; Hay, Kenneth G.; Wright, Stephen; Langford, Nigel; Duxbury, Geoffrey; Mankelevich, Yuri A.

    2009-08-01

    CH4 and C2H2 molecules (and their interconversion) in hydrocarbon/rare gas/H2 gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm-1 using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H2 plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r ,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH4 and C2H2 molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH4 and C2H2. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH4→C2H2 conversion occurs most efficiently in an annular shell around the central plasma (characterized by 14002H2→CH4 is favored in the more distant regions where Tgas<1400 K. Analysis of the multistep interconversion mechanism reveals substantial net consumption of H atoms accompanying the CH4→C2H2 conversion, whereas the reverse C2H2→CH4 process only requires H atoms to drive the reactions; H atoms are not consumed by the overall

  15. The influence of C2H2 and dust formation on the time dependence of metastable argon density in pulsed plasmas

    Stefanovic, Ilija; Sadeghi, Nader; Winter, Jörg

    2010-01-01

    Abstract Diode laser absorption at 772.38 nm is used to measure the time resolved density of Ar*(3 P 2) metastable atoms in a capacitively coupled radio-frequency (RF) discharge running in argon/acetylene mixture at 0.1 mbar. The RF power is pulsed at 100 Hz and the density of Ar*(3 P 2) atoms in the 5 ms ON time and in the afterglow are recorded. Different plasma conditions, namely: 1) pure argon, 2) argon + 7% acetylene before powder formation, 3) argon + 7% acetylene after dust particle...

  16. 空腹血糖、糖负荷后2h血糖和HbA1C对糖尿病的诊断价值%The diagnostic value of fasting plasma glucose, 2 h plasma glucose after glucose loading, and HbA1C to diabetes mellitus

    王毅方; 黄辉; 彭贵成; 杨玉; 邓仲良; 黄光宇; 杨庆东; 卢力沾; 朱浩源

    2015-01-01

    采用整群抽样的方法,对东莞市横沥镇35岁以上的6656名户籍居民进行问卷调查和身高、体重、腰围、臀围、血压测量,同时检测血脂、空腹血糖(FPG)、HbA1C及糖负荷后2h血糖(2hPG),仅单项血糖指标增高而无糖尿病症状者1周以后再次检测,分析采用FPG、2hPG、HbA1C对糖尿病的诊断价值.结果显示,第1周检测中,FPG、HbA1C、2hPG三者中一项以上增高的初诊糖尿病共有800例,其中FPG、HbA1C、2hPG增高的初诊糖尿病分别为42.0%、55.3%、67.1%;两两组合时FPG+HbA1C、FPG+2hPG、HbA1C+2hPG增高的初诊糖尿病分别为68.8%、79.8%、91.0%.第2周对仅单项指标增高而未能确诊的糖尿病人群进行复查,FPG、HbA1C、2hPG增高的重复率各为27.6%、74.3%、31.4%;最终共确诊糖尿病患者503例,其中FPG、HbA1C、2hPG确诊糖尿病各占55.7%、76.9%、69.8%,两两组合时,FPG+HbA1C、FPG+2hPG、HbA1C+2hPG确诊糖尿病各占87.3%、78.7%、96.8%.结果提示,单纯FPG、HbA1C、2hPG诊断糖尿病均存在不同程度的漏诊,两两组合可减少漏诊率.HbA1C较FPG、2hPG更适合作为诊断糖尿病的指标;HbA1C+2hPG明显优于其他两种组合.%A total of 6 656 residents aged above 35 years in Hengli,Dongguan,were included in this epidemiologic investigation.A questionnaire survey was performed.Body height,weight,waist circumference,hip circumference,and blood pressure were measured.The plasma lipid,fasting plasma glucose (FPG),HbA1C,and 2 h plasma glucose (2hPG) levels were detected.The test was repeated one week later if only one index was increased without any symptoms of diabetes mellitus.The diagnostic values of FPG,HbA1C,and 2hPG in diabetes mellitus were explored.The results showed that at the first week,800 subjects were initially diagnosed as cases of diabetes mellitus by only one of the elevated FPG,HbA1Cor 2hPG values.The rates of single elevations of FPG,HbA1C,and 2hPG were 42.0%,55.3

  17. Quantitation of methadone enantiomers in humans using stable isotope-labeled (2H3)-, (2H5)-, and (2H8)Methadone

    Nakamura, K.; Hachey, D.L.; Kreek, M.J.; Irving, C.S.; Klein, P.D.

    1982-01-01

    A new technique for simultaneous stereoselective kinetic studies of methadone enantiomers was developed using three deuterium-labeled forms of methadone and GLC-chemical-ionization mass spectrometry. A racemic mixture (1:1) of (R)-(-)-(2H5)methadone (l-form) and (S)-(R)-(2H3)methadone (d-form) was administered orally in place of a single daily dose of unlabeled (+/-)-(2H0)methadone in long-term maintenance patients. Racemic (+/-)-(2H8)methadone was used as an internal standard for the simultaneous quantitation of (2H0)-, (2H3)-, and (2H5)methadone in plasma and urine. A newly developed extraction procedure, using a short, disposable C18 reversed-phase cartridge and improved chemical-ionization procedures employing ammonia gas, resulted in significant reduction of the background impurities contributing to the ions used for isotopic abundance measurements. These improvements enabled the measurement of labeled plasma methadone levels for 120 hr following a single dose. This methodology was applied to the study of methadone kinetics in two patients; in both patients, the analgesically active l-enantiomer of the drug had a longer plasma elimination half-life and a smaller area under the plasma disappearance curve than did the inactive d-form.

  18. Quantitation of methadone enantiomers in humans using stable isotope-labeled [2H3]-, [2H5]-, and [2H8]Methadone

    A new technique for simultaneous stereoselective kinetic studies of methadone enantiomers was developed using three deuterium-labeled forms of methadone and GLC-chemical-ionization mass spectrometry. A racemic mixture (1:1) of (R)-(-)-[2H5]methadone (l-form) and (S)-(R)-[2H3]methadone (d-form) was administered orally in place of a single daily dose of unlabeled (+/-)-[2H0]methadone in long-term maintenance patients. Racemic (+/-)-[2H8]methadone was used as an internal standard for the simultaneous quantitation of [2H0]-, [2H3]-, and [2H5]methadone in plasma and urine. A newly developed extraction procedure, using a short, disposable C18 reversed-phase cartridge and improved chemical-ionization procedures employing ammonia gas, resulted in significant reduction of the background impurities contributing to the ions used for isotopic abundance measurements. These improvements enabled the measurement of labeled plasma methadone levels for 120 hr following a single dose. This methodology was applied to the study of methadone kinetics in two patients; in both patients, the analgesically active l-enantiomer of the drug had a longer plasma elimination half-life and a smaller area under the plasma disappearance curve than did the inactive d-form

  19. Syntheses of [5-2H]-uracil, [5-2H]-cytosine, [6-2H]-uracil and [6-2H]-cytosine

    Syntheses of [5-2H]-, [6-2H]-uracil and [5-2H]-, [6-2H]-cytosine were investigated. The catalytic reaction of uracil or cytosine with 2H2 gas in alkaline media gave rise to [6-2H]-compounds almost exclusively. On the other hand, the reaction of 5-bromouracil or 5-bromocytosine with 2H2 gas gave rise to a mixture of [5-2H]-, [6-2H]- and [5-2H, 6-2H]-compounds depending on the experimental conditions. By controlling the temperature, the pressure of 2H2 gas and the amount of catalyst, [5-2H]-uracil and [5-2H]-cytosine were obtained. The isotopic distribution in each product was measured by 1H NMR spectroscopy combined with an HPLC method. (author)

  20. 空腹血糖、餐后2h血糖及糖化血红蛋白对糖尿病的诊断价值%Diagnostic value of fasting plasma glucose, 2 h postprandial plasma glucose and glycosylated hemoglobin on diabetes mellitus

    陈妍; 刘建国; 徐磊; 滑劲咏; 王惠梅; 常冉; 郭春丽

    2012-01-01

    Aim:To investigate the diagnostic value of the fasting plasma glucose (FPG) ,2 h postprandial plasma glucose (2 h-PG) and glycosylated hemoglobin ( HbAlc) towards diabetes mellitus ( DM) and impaired glucose regulation (IGR). Methods: A total of 738 patients with complete clinical data were collected from December 2009 to August 2011 in the Second People's Hospital of Zhengzhou and Zhengzhou Central Hospital . All the subjects were detected for the FPG , HbAlc and 2 h-PG,while the levels of HbAlc ranging 5.4% to 7. 0% were enrolled the study. Receiver operating characteristic curve (ROC curve) was used to examine the optimal cut-point of HbAlc for detecting DM and IGR. ReSUltS; Regarding FPG≥7. 0 mmol/L and (or) 2 h-PG≥11. 1 mmol/L as the gold standard for diagnosing DM and making ROC curve,and the optimal cut-point of HbAlc for diagnosing DM was 6. 35% , with sensitivity of 0. 698 , specificity of 0. 680 , positive likelihood ratio of 2. 18 and negative likelihood ratio of 0.44. Regarding FPG 6. 1 - 6. 9 mmol/L and (or) 2 h-PG 7. 8 ~ 11. 1 mmol/L as the gold standard for diagnosing IGR and making ROC curve ,and the optimal cut-point of HbAlc was 6.0% ,with sensitivity of 0. 646, specificity of 0. 659 , positive likelihood ratio of 1.89 and negative likelihood ratio of 0.54. Conclusion:There are a medium sensitivity to diagnose DM by HbAlc and a lower sensitivity to diagnose IGR by HbAlc. Combined test may contribute to improve the detection rate of DM and IGR .%目的:探讨空腹血糖、餐后2 h血糖及糖化血红蛋白(HbAlc)对糖尿病及糖调节受损的诊断价值.方法:收集2009年12月至2011年8月在郑州市第二人民医院和郑州市中心医院检测空腹血糖(FPG)、糖化血红蛋白(HbAlc)和餐后2 h血糖(2h-PG)的738例临床资料完整的、HbAlc在5.4%~7.0%的就诊者入选该研究,采用ROC曲线确定HbAlc预测糖尿病及糖调节受损的诊断界点.结果:以FPG≥7.0 mmol/L和(或)餐后2 h-PG≥11.1 mmol/L为诊

  1. Atomic and plasma-material interaction data for fusion. V. 8. Elastic and related transport cross sections for collisions among isotopomers of H+ + H, H+ + H2, H+ + He, H + H, and H + H2

    The Volume 8 of the 'Atomic and Plasma-Material Interaction Data for Fusion' provides an exhaustive source of information on elastic scattering, momentum transfer and viscosity cross sections for collisions of hydrogenic ions, atoms and molecules, and their isotopes, in the energy range pertinent to fusion reactor divertor plasmas and extending (in its low-energy part) to collision conditions that are relevant for astrophysics. Hydrogen ion-helium atom collisions are also included. The reported cross sections are obtained from extensive quantum-mechanical calculations and can be regarded as having very high accuracy

  2. Nitriding of titanium and its alloys by N2, NH3 or mixtures of N2 + H2 in a dc arc plasma at low pressures ( or = to torr)

    Avni, R.

    1984-01-01

    The dc glow discharges in different gas mixtures of Ar + N2, Ar + NH3 or Ar + N2 + H2 result in the surface nitriding of Ti metal and its alloy (Ti6Al4V). Various gas mixtures were used in order to establish the main active species governing the nitriding process, i.e., N, N2, NH, or NH2 as excited or ionized particles. The dc discharge was sampled and analyzed by quadruple mass spectrometry (QPMS) and optical emission spectroscopy (OES), and the nitrided samples were analyzed by scanning electron microscopy (SEM) with an EDAX attachment, microhardness, and Fourier transform infrared reflectance spectrometry (FTIR). It was found that the excited and ionized nitrogen and hydrogen atoms are the main species responsible for the nitriding process in a dc glow discharge.

  3. Mecanismos cinéticos y distribuciones energéticas de iones (H3+, N2H+, CH3+...) en plasmas fríos de H2/N2/CH4

    Tanarro, I.; Herrero, V. J.; Islyaikin, A.; Tabarés, F. L.; Tafalla, D.

    En este trabajo se presenta el estudio espectrométrico de los plasmas levemente ionizados generados en una descarga continua a baja presión de H2 con trazas de N2 y CH4, orientado principalmente a identificar la naturaleza y distribución energética de los iones que en ella se producen, y a asignar algunos de los mecanismos cinéticos elementales de formación y destrucción de tales especies. Alguno de los iones mayoritarios de estos plasmas, como el H3+, presenta gran interés desde el punto de vista de la Astrofísica por su prevista intervención en la química de las ionosferas planetarias y del medio interestelar, al actuar como sustancia intermedia en la formación de gran variedad de especies moleculares; si bien, dada su pequeña concentración, su observación real en el espacio se demoró hasta la pasada década de los años 90, cuando fue detectado por primera vez en la atmósfera de Júpiter y en otros objetos estelares. Del mismo modo que los trabajos espectroscópicos de laboratorio resultan indispensables para la posterior identificación de las especies observadas en el espacio, es de esperar que la asignación de los procesos cinéticos más importantes que tienen lugar en los plasmas generados en reactores de descarga, como los aquí presentados, permitan extrapolar los resultados así obtenidos al esclarecimiento de los mecanismos fisico-químicos participantes en otros medios observables únicamente a larga distancia.

  4. Intense laser induced field ionization of C2H2, C2H4,and C2H6

    GAO Lirong; JI Na; XONG Yijia; TANG Xiaoping; KONG Fan'ao

    2003-01-01

    Using HOMO Field Ionization Model, the tunneling probabilities and the theoretical threshold intensities of the field ionizations of acetylene, ethylene, and ethane in intense laser field are calculated. C2H2, C2H4, and C2H6 were irradiated by 800 nm, 100 fs laser pulses with the intensity range of 1013-1014 W/cm2. A TOF-mass spectrometer was coupled to the laser system and used to experimentally investigate the field ionization of these molecules. The experimental ionization threshold intensities are obtained. The calculating results of the three molecules agree well with the experimental results, indicating that HOMO Field Ionization Model is valid for the ionization of polyatomic molecules in intense laser field.

  5. Synthesis of 1-C2H3 theophylline and 3-C2H3 theophylline

    This article describes a three step-selective deuteration method of 1-methyl and 3-methylxanthine, after protection of the N-7 position by chloromethylpivalate and alkylation by trideuteromethyl iodide ; yielding 1-C2H3 and 3-C2H3 theophylline. (author)

  6. Supramolecular stabilization of N(2)H(7)(+).

    Atwood, Jerry L; Barbour, Leonard J; Jerga, Agoston

    2002-03-13

    The cation N(2)H(7)(+) has been stabilized in a largely hydrophobic supramolecular environment and characterized in the solid state. The cation is situated in the bowl-shaped cavity of calix[4]arene. All of the hydrogen atoms are clearly discernible owing to high-quality X-ray data as well as lack of disorder and symmetry-imposed ambiguity. It appears that electrostatic interactions play a critical role in stabilizing the structure. PMID:11878959

  7. Dissociative recombination of N2H+

    dos Santos, S. Fonseca; Ngassam, V.; Orel, A. E.; Larson, Å.

    2016-08-01

    The direct and indirect mechanisms of dissociative recombination of N2H+ are theoretically studied. At low energies, the electron capture is found to be driven by recombination into bound Rydberg states, while at collision energies above 0.1 eV, the direct capture and dissociation along electronic resonant states becomes important. Electron-scattering calculations using the complex Kohn variational method are performed to obtain the scattering matrix as well as energy positions and autoionization widths of resonant states. Potential-energy surfaces of electronic bound states of N2H and N2H+ are computed using structure calculations with the multireference configuration interaction method. The cross section for the indirect mechanism is calculated using a vibrational frame transformation of the elements of the scattering matrix at energies just above the ionization threshold. Here vibrational excitations of the ionic core from v =0 to v =1 and v =2 for all three normal modes are considered and autoionization is neglected. The cross section for the direct dissociation along electronic resonant states is computed with wave-packet calculations using the multiconfiguration time-dependent Hartree method, where all three internal degrees of freedom are considered. The calculated cross sections are compared to measurements.

  8. Synthesis of (2R,S)-[2-2H] and [2,3-2H] tryptophan

    α-Deuterated tryptophan was prepared either by exchange of the α-hydrogen of tryptophan or by hydrolysis and decarboxylation of ethyl 2-formamido-2-carbethoxy-3-indole propionate, followed by treatment with CH3COO2H. α,β-dideuterated tryptophan was in turn synthetized from ethyl-α-acetamido-indole-3-acrylate, by catalytic deuteration (2H2/Pd-C) and alkaline hydrolysis (NaO2H/2H2O). (author)

  9. Determination of muscle protein synthesis rates in fish using (2)H2O and (2)H NMR analysis of alanine.

    Marques, Cátia; Viegas, Filipa; Rito, João; Jones, John; Viegas, Ivan

    2016-09-15

    Following administration of deuterated water ((2)H2O), the fractional synthetic rate (FSR) of a given endogenous protein can be estimated by (2)H-enrichment quantification of its alanine residues. Currently, this is measured by mass spectrometry following a derivatization procedure. Muscle FSR was measured by (1)H/(2)H NMR analysis of alanine from seabass kept for 6 days in 5% (2)H-enriched saltwater, following acid hydrolysis and amino acid isolation by cation-exchange chromatography of muscle tissue. The analysis is simple and robust, and provides precise measurements of excess alanine (2)H-enrichment in the 0.1-0.4% range from 50 mmol of alanine recovered from muscle protein. PMID:27418547

  10. The enantiospecific synthesis of [5-2H]-5-epi-shikimic acid and of (6R) [6-2H]-, (6S) [6-2H]- and [6-2H2] shikimic acid

    The enantioselective synthesis of [5-2H]-5-epi-shikimic acid starting from commercially available L-shikimic acid has been accomplished in this work. The introduction of the stable isotope was facilitated by an enzymic reduction of a ketone. An interesting stereospecific enolisation was also observed during this reaction resulting in partial deuteration of the 6-equatorial position. In addition, the enantioselective syntheses of methyl (6R) [6-2H]-, and (6S) [6-2H] shikimate are described. The procedure is an adaptation of a reported enantiospecific synthesis of shikimic acid, with the inclusion of an enzymic reduction step. (author)

  11. Theoretical Studies on N2H+O Reaction

    L(U) Ying-wen; L(U) Wen-cai; SU Zhong-min

    2008-01-01

    The N2H+O potential energy profile was studied at the CCSD(T)/6-311G++(dfp)//MP2/6-311G(d,p) level.Reactions associated with four intermediates(cis-HNNO, trans-HNNO, NNHO, and NNOH) were investigated. The results indicate that N2H+O reaction toward H+N2O is more favored than that toward N2+OH, consistent with previous experimental studies. The pathways for the two reactions are found to go through cis-HNNO, transition state, and finally to the products. The N2H+O→NH+NO reaction was studied in detail. Product NO in such a reaction is likely to occur via cis-HNNO, followed by trans-HNNO, and finally dissociates into NH+NO. These results suggest that N2H+O→NH+NO is an important channel in NO production.

  12. C2H observations toward the Orion Bar

    Nagy, Z.; Ossenkopf, V.; Van der Tak, F. F. S.; Faure, A.; Makai, Z.; Bergin, E. A.

    2015-06-01

    Context. The ethynyl radical (C2H) is one of the first radicals to be detected in the interstellar medium. Its higher rotational transitions have recently become available with the Herschel Space Observatory. Aims: We aim to constrain the physical parameters of the C2H emitting gas toward the Orion Bar. Methods: We analyze the C2H line intensities measured toward the Orion Bar CO+ Peak and Herschel/HIFI maps of C2H, CH, and HCO+ and a NANTEN map of [Ci]. We interpret the observed C2H emission using the combination of Herschel/HIFI and NANTEN data with radiative transfer and PDR models. Results: Five rotational transitions of C2H (from N = 6-5 up to N = 10-9) have been detected in the HIFI frequency range toward the CO+ peak of the Orion Bar. Based on the five detected C2H transitions, a single component rotational diagram analysis gives a rotation temperature of ~64 K and a beam-averaged C2H column density of 4 × 1013 cm-2. The rotational diagram is also consistent with a two-component fit, resulting in rotation temperatures of 43 ± 0.2 K and 123 ± 21 K and in beam-averaged column densities of ~8.3 × 1013 cm-2 and ~2.3 × 1013 cm-2 for the three lower-N and for the three higher-N transitions, respectively. The measured five rotational transitions cannot be explained by any single parameter model. According to a non-LTE model, most of the C2H column density produces the lower-N C2H transitions and traces a warm (Tkin ~ 100-150 K) and dense (n(H2) ~ 105-106 cm-3) gas. A small fraction of the C2H column density is required to reproduce the intensity of the highest-N transitions (N = 9-8 and N = 10-9) originating in a high-density (n(H2) ~5 × 106 cm-3) hot (Tkin ~ 400 K) gas. The total beam-averaged C2H column density in the model is 1014 cm-2. A comparison of the spatial distribution of C2H to those of CH, HCO+, and [Ci] shows the best correlation with CH. Conclusions: Both the non-LTE radiative transfer model and a simple PDR model representing the Orion Bar

  13. Atmospheric chemistry of CF3OCF2CF2H and CF3OC(CF3)2H

    Andersen, Mads Peter Sulbæk; Nielsen, O J; Wallington, T J;

    2005-01-01

    gives CF3OC(O)CF3 and COF2 in molar yields that are indistinguishable from 100%. Quantitative infrared spectra were recorded and used to estimate global warming potentials of 3690 and 8230 (100 year time horizon, relative to CO2) for CF3OCF2CF2H and CF3OC(CF3)2H, respectively. All experiments were...

  14. Spectroscopic measurements of the electron temperature in low pressure radiofrequency Ar/H{sub 2}/C{sub 2}H{sub 2} and Ar/H{sub 2}/CH{sub 4} plasmas used for the synthesis of nanocarbon structures

    Gordillo-Vazquez, F J [Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Camero, M [Instituto de Ciencia de Materiales de Madrid (CSIC), 28049 Madrid (Spain); Gomez-Aleixandre, C [Instituto de Ciencia de Materiales de Madrid (CSIC), 28049 Madrid (Spain)

    2006-02-15

    This paper deals with optical emission spectroscopy studies of low pressure (0.1-0.5 Torr) capacitively coupled radiofrequency hydrocarbon/argon-rich plasmas used for the synthesis of nanocarbon structures. The main goal of this paper is to obtain the electron temperature of such far-from-equilibrium plasmas as a function of the pressure, the excitation power and the argon content. In doing so, we have found that the argon upper energy levels used for electron temperature estimation remain close to corona balance. The latter has allowed us to use a modified Boltzmann plot technique to derive the electron temperature. It was found that, for the plasmas investigated, an increase of the argon population density (from 10% to 95%) leads to a pronounced decrease of the electron temperature while an increase of the processing pressure produces a moderate increase of the electron temperature. Additionally, the increase of the power from 50 to 300 W produces a very slight growth of the electron temperature.

  15. High pressure oxidation of C2H4/NO mixtures

    Giménez-López, J.; Alzueta, M.U.; Rasmussen, C.T.;

    2011-01-01

    An experimental and kinetic modeling study of the interaction between C2H4 and NO has been performed under flow reactor conditions in the intermediate temperature range (600–900K), high pressure (60bar), and for stoichiometries ranging from reducing to oxidizing conditions. The main reaction...... reaction HOCH2CH2OO+NO→CH2OH+CH2O+NO2, which pushes a complex system of partial equilibria towards products. This is a confirmation of the findings of Doughty et al. [3] for a similar system at atmospheric pressure. Under reducing conditions and temperatures above 700K, a significant fraction of the NOx is...... pathways of the C2H4/O2/NOx conversion, the capacity of C2H4 to remove NO, and the influence of the presence of NOx on the C2H4 oxidation are analyzed. Compared to the C2H4/O2 system, the presence of NOx shifts the onset of reaction 75–150K to lower temperatures. The mechanism of sensitization involves the...

  16. Alanine flux in obese and healthy humans as evaluated by 15N- and 2H3-labeled alanines

    Estimates of plasma alanine flux as measured in humans using L-[15N]-alanine or L-[3,3,3-2H3]alanine were compared by simultaneous intravenous infusion of both tracers. Plasma isotope enrichments were measured by chemical ionization gas chromatography-mass spectrometry. In 16 obese women before and during a hypocaloric diet and in 4 normal men in the postabsorptive and fed states, the fluxes were highly correlated (r2 = 0.93) although plasma alanine flux with the 2H tracer was two to three times greater than that obtained with [15N]alanine. The fluxes decreased with the hypocaloric diet in obese subjects and increased during the fed state in healthy adults. Thus, although the estimates of alanine flux differed according to the tracer used, both appear to give equivalent information about changes in alanine kinetics induced by the nutritional conditions examined

  17. N2H+ Observations of Molecular Cloud Cores in Taurus

    Tatematsu, K; Umemoto, T; Kandori, R.; Y. Sekimoto

    2004-01-01

    N2H+ observations of molecular cloud cores in Taurus with the Nobeyama 45 m radio telescope are reported. We compare ``cores with young stars'' with ``cores without young stars''. The differences in core radius, linewidth, and core mass are small. Linewidth is dominated by thermal motions in both cases. N2H+ maps show that the intensity distribution does not differ much between cores without stars and those with stars. This is in contrast to the result previously obtained in H13CO+ toward Tau...

  18. Search for the isomers of C2H3NO and C2H3NS in the Interstellar Medium

    Etim, Emmanuel; Chakrabarti, Sandip Kumar; Das, Ankan; Gorai, Prasanta; Arunan, Elangannan

    2016-07-01

    With about 40% of all the known interstellar and circumstellar molecules having their isomeric analogues as known astromolecules, isomerism remains one of the leading themes in interstellar chemistry. In this regard, the recent detection of methyl isocyanate (with a number of isomeric analogues) in the Sgr B2(N) giant molecular cloud opens a new window for the possible astronomical detection of other C_2H_3NO isomers. The present work looks at the possibility of detecting other isomers of methyl isocyanate by considering different factors such as thermodynamic stability of the different isomers with respect to the Energy, Stability and Abundance (ESA) relationship, effect of interstellar hydrogen bonding with respect to the formation these isomers on the surface of the interstellar dust grains, possible formation routes for these isomers, spectroscopic parameters for potential astromolecules among these isomers, chemical modeling among other studies. The same studies are repeated for the C_2H_3NS isomers which are the isoelectroninc analogues of the C_2H_3NO isomers taking into account the unique chemistry of S and O-containing interstellar molecular species. Among the C_2H_3NS isomers, methyl isothiocyanate remains the most potential candidate for astronomical observation.

  19. Dynamics of He2++H ionization with exponential cosine-screened Coulomb potential

    Dynamics of He2++H ionization in dense quantum plasmas (DQPs) has been studied by the classical trajectory Monte Carlo method. The interactions between charged particles have been described by the exponential cosine-screened Coulomb potential. It is found that ionization cross sections in plasma environments are obviously larger than those in plasma-free environments due to the screening effects. Cross sections for H+ also have been calculated for comparison. For H+, cross sections increase with the increase of screening effects. However, for He2+, cross sections begin to decrease in strong screening effects at intermediate energies. Furthermore, He2+ impact ionization cross sections in weakly coupled plasmas (WCPs) also have been calculated. The interactions have been described by the static screened Coulomb potential. It is found that when screening effects are weak, cross sections in DQPs and WCPs are approximately the same. As screening effects increase, cross sections in DQPs become larger than those in WCPs at high energies. However, when screening effects are strong enough, cross sections in DQPs become smaller than those in WCPs at low and intermediate energies. (paper)

  20. Synthesis and structure of [(UO2(OH)(C6NO2H4)(C6NO2H5)

    [(UO2(OH)(C6NO2H4)(C6NO2H5)] (1) monocrystals are synthesized and studied by the method of x-ray diffraction. The compound is crystallized into monoclinic lattice with parameters: space group P21/n, Z=2, a=8.789(1), b=16.635(7), c=9.238(1), β=97.89(1). Basic structural units of the crystal are chains with composition coincidental with composition of compound belonging to crystal-chemical group AM2B2M1 (A=UO22+; M2=OH-, B2 and M1 - molecules of isonicotinic acid or isonicotinate-ions) of uranyl complexes. Reciprocal packing of the chains into three-dimensional skeleton is determined by hydrogen bonds

  1. Evidence of an association between the Arg72 allele of the peptide YY and increased risk of type 2 diabetes

    Torekov, Signe S; Larsen, Lesli H; Glümer, Charlotte; Borch-Johnsen, Knut; Jørgensen, Torben; Holst, Jens J; Madsen, Ole D; Hansen, Torben; Pedersen, Oluf

    2005-01-01

    1.05-1.35]). The same polymorphism associated with overweight (25 plasma glucose level 2 h after an oral glucose...... tolerance test (OGTT) (P = 0.03), an increased area under the curve for the post-OGTT plasma glucose level (P = 0.03), and a lower insulinogenic index (P = 0.01). In conclusion, the common Arg allele of the PYY Arg72Thr variant modestly associates with type 2 diabetes and with type 2 diabetes...

  2. Hydrophobization of epoxy nanocomposite surface with 1H,1H,2H,2H-perfluorooctyltrichlorosilane for superhydrophobic properties

    Psarski, Maciej; Marczak, Jacek; Celichowski, Grzegorz; Sobieraj, Grzegorz; Gumowski, Konrad; Zhou, Feng; Liu, Weimin

    2012-10-01

    Nature inspires the design of synthetic materials with superhydrophobic properties, which can be used for applications ranging from self-cleaning surfaces to microfluidic devices. Their water repellent properties are due to hierarchical (micrometer- and nanometre-scale) surface morphological structures, either made of hydrophobic substances or hydrophobized by appropriate surface treatment. In this work, the efficiency of two surface treatment procedures, with a hydrophobic fluoropolymer, synthesized and deposited from 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS) is investigated. The procedures involved reactions from the gas and liquid phases of the PFOTS/hexane solutions. The hierarchical structure is created in an epoxy nanocomposite surface, by filling the resin with alumina nanoparticles and micron-sized glass beads and subsequent sandblasting with corundum microparticles. The chemical structure of the deposited fluoropolymer was examined using XPS spectroscopy. The topography of the modified surfaces was characterized using scanning electron microscopy (SEM), and atomic force microscopy (AFM). The hydrophobic properties of the modified surfaces were investigated by water contact and sliding angles measurements. The surfaces exhibited water contact angles of above 150° for both modification procedures, however only the gas phase modification provided the non-sticking behaviour of water droplets (sliding angle of 3°). The discrepancy is attributed to extra surface roughness provided by the latter procedure.

  3. Detailed Studies of Hydrocarbon Radicals: C2H Dissociation

    Wittig, Curt

    2014-10-06

    A novel experimental technique was examined whose goal was the ejection of radical species into the gas phase from a platform (film) of cold non-reactive material. The underlying principle was one of photo-initiated heat release in a stratum that lies below a layer of CO2 or a layer of amorphous solid water (ASW) and CO2. A molecular precursor to the radical species of interest is deposited near or on the film's surface, where it can be photo-dissociated. It proved unfeasible to avoid the rampant formation of fissures, as opposed to large "flakes." This led to many interesting results, but resulted in our aborting the scheme as a means of launching cold C2H radical into the gas phase. A journal article resulted that is germane to astrophysics but not combustion chemistry.

  4. 2H NMR studies of supercooled and glassy aspirin

    Nath, R.; Nowaczyk, A.; Geil, B.; Bohmer, R.

    2007-11-01

    Acetyl salicylic acid, deuterated at the methyl group, was investigated using 2H-NMR in its supercooled and glassy states. Just above the glass transition temperature the molecular reorientations were studied using stimulated-echo spectroscopy and demonstrated a large degree of similarity with other glass formers. Deep in the glassy phase the NMR spectra look similar to those reported for the crystal [A. Detken, P. Focke, H. Zimmermann, U. Haeberlen, Z. Olejniczak, Z. T. Lalowicz, Z. Naturforsch. A 50 (1995) 95] and below 20 K they are indicative for rotational tunneling with a relatively large tunneling frequency. Measurements of the spin-lattice relaxation times for temperatures below 150 K reveal a broad distribution of correlation times in the glass. The dominant energy barrier characterizing the slow-down of the methyl group is significantly smaller than the well defined barrier in the crystal.

  5. Doping dependent plasmon dispersion in 2 H -transition metal dichalcogenides

    Müller, Eric; Büchner, Bernd; Habenicht, Carsten; König, Andreas; Knupfer, Martin; Berger, Helmuth; Huotari, Simo

    2016-07-01

    We report the behavior of the charge carrier plasmon of 2 H -transition metal dichalcogenides (TMDs) as a function of intercalation with alkali metals. Intercalation and concurrent doping of the TMD layers have a substantial impact on plasmon energy and dispersion. While the plasmon energy shifts are related to the intercalation level as expected within a simple homogeneous electron gas picture, the plasmon dispersion changes in a peculiar manner independent of the intercalant and the TMD materials. Starting from a negative dispersion, the slope of the plasmon dispersion changes sign and grows monotonously upon doping. Quantitatively, the increase of this slope depends on the orbital character (4 d or 5 d ) of the conduction bands, which indicates a decisive role of band structure effects on the plasmon behavior.

  6. 2H and 18O Freshwater Isoscapes of Scotland

    Meier-Augenstein, Wolfram; Hoogewerff, Jurian; Kemp, Helen; Frew, Danny

    2013-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwaters by the Scottish Environment Protection Agency (SEPA) fulfils legislative requirements with regards to water quality but new scientific methods involving stable isotope analysis present an opportunity combining these mandatory monitoring schemes with fundamental research to inform and deliver on current and nascent government policies [1] through gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and food security. For example, 2H and 18O isoscapes of Scottish freshwater could be used to underpin research and its applications in: • Climate change - Using longitudinal changes in the characteristic isotope composition of freshwater lochs and reservoirs as proxy, isoscapes will provide a means to assess if and how changes in temperature and weather patterns might impact on precipitation patterns and amount. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish soft fruit and Scottish Whisky. During 2011 and 2012, with the support of SEPA more than 110 samples from freshwater lochs and reservoirs were collected from 127 different locations across Scotland including the Highlands and Islands. Here we present the results of this sampling and analysis exercise isotope analyses in form of 2H and 18O isoscapes with an unprecedented grid resolution of 26.5 × 26.5 km (or 16.4 × 16.4 miles). [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland

  7. Nonempirical LCAO-MO-SCF calculations of geometric structure and force field of Be2H4 molecule and Be2H3+ ion

    Determination of equilibrium geometry, of the most general force field and frequencies of normal oscillations of Be2H4 molecule and Be2H3+ ion have been carried out. The ''Orbital 8'' programme has been used for nonempirical calculations on the basis of linear combinations of nodalless gauss functions. It is shown that flat bridge Dsub(2h) symmetry configuration is the only one of nuclei in Be2H4 molecule and linear configuration of D infinity h symmetry in Be2H3+ ion. A complete set of molecular constants of Be2H4 and Be2H3+ is obtained, which permits to carry out calculations of thermodynamical functions of these compounds by the methods of statistical physics

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

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

    2012-11-12

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

  9. The Distribution of Synaptotagmin Ⅱ in RBL-2H3 and Its Regulation on Exocytosis of Lysosomes in RBL-2H3

    Jicheng Zhang; Jianmin Wu; Shixiu Pan; Wenli Lv

    2005-01-01

    Synaptotagmin (Syt) constitutes a family of membrane-trafficking proteins, so far nearly 20 Syts have been discovered. Extensive work showed that synatotagmins were a potential Ca2+ sensor for regulated exocytosis. This study was to investigate the expression and location of synaptotagmin Ⅱ (Syt2) in RBL-2H3 (RBL) and its role in regulating exocytosis of RBL. The expression of Syt2 in RBL was confirmed by Western blot. The recombinant expression vector pEGFP-N1-Syt2 was constructed and transfected into RBL by electroporation, the stable transfectant RBL-Syt2-S expressing fusion protein Syt2-EGFP were obtained and Syt2 was highly concentrated at plasma membrane with little detected in cytoplasm. To analyze the role of Syt2 during exocytosis of RBL, the release of cathepsin D was assayed by immunoblotting. Compared with control, the release of cathepsin D by RBL-Syt2-S was markedly decreased. The results indicated that Syt2 played a negative regulation in exocytosis of lysosomes in RBL.

  10. Human organic cation transporter 2 (hOCT2): Inhibitor studies using S2-hOCT2 cells

    Highly expressed in kidney and located on the basolateral membrane, human organic cation transporter 2 (hOCT2) can transport various compounds (i.e. drugs and toxins) into the proximal tubular cell. Using cultured proximal tubule cells stably expressing hOCT2 (i.e. S2-hOCT2 cells), we sought to probe different compound classes (e.g. analgesics, anti-depressants, anti-psychotics, disinfectant, herbicides, insecticides, local anesthetic, muscarinic acetylcholine receptor antagonist, sedatives, steroid hormone, stimulants and toxins) for their ability to inhibit 14C-TEA uptake, a prototypical OCT2 substrate. Aconitine, amitriptyline, atropine, chlorpyrifos, diazepam, fenitrothion, haloperidol, lidocaine, malathion, mianserin, nicotine and triazolam significantly inhibited 14C-TEA uptake; IC50 values were 59.2, 2.4, 2.0, 20.7, 32.3, 13.2, 32.5, 104.6, 71.1, 17.7, 52.8 and 65.5 μM, respectively. In addition, aconitine, amitriptyline, atropine, chlorpyrifos, fenitrothion, haloperidol, lidocaine, and nicotine displayed competitive inhibition with Ki values of 145.6, 2.5, 2.4, 24.8, 16.9, 51.6, 86.8 and 57.7 μM, respectively. These in vitro data support the notion that compounds pertaining to a wide variety of different drug classes have the potential to decrease renal clearance of drugs transported via hOCT2. Consequently, these data warrant additional studies to probe hOCT2 and its role to influence drug pharmacokinetics

  11. Temperature dependence of third order ion molecule reactions. The reaction H+3 + 2H2 = H+5 + H2

    The rate constants k1 for Reaction (1): H+3+2H2 = H+5+H2 were measured in the temperature range 100--300 degreeK. The temperature dependence of k1 has the form k1proportionalT-/subn/, where n=2.3. Pierce and Porter have reported a much stronger negative temperature dependence with n=4.6. The difference arises from a determination of k1 at 300 degreeK obtained by Arifov and used by Porter. The present k1 (300 degreeK) =9times10-30 (cm6 molecules-2center-dotsec-1). This is more than an order of magnitude larger than the Arifov value. The temperature dependence of third body dependent association reactions like (1) is examined on the basis of the energy transfer theory and the recently proposed trimolecular complex transition state theory by Meot-Ner, Solomon, Field, and Gershinowitz. The temperature dependence of the rate constant for the reverse reaction (-1) is obtained from k1 and the previously determined temperature dependence of the equilibria (1). k/sub -//sub 1/ gives a good straight line Arrhenius plot leading to k/sub -//sub 1/ =8.7times10-6 exp(-8.4/RT) cm3 molecules-1center-dotsec-1. The activation energy is in kcal/mole. The preexponential factor is much larger than the rate constant for Langevin collisions. This is typical for pyrolysis of ions involving second order activation

  12. Simulation of nanoparticle coagulation in radio-frequency capacitively coupled C2H2 discharges

    A self-consistent fluid model is employed to investigate the coagulation stage of nanoparticle formation, growth, charging, and transport in a radio-frequency capacitively coupled parallel-plate acetylene (C2H2) discharge. In our simulation, the distribution of neutral species across the electrode gap is determined by mass continuity, momentum balance, and energy balance equations. Since a thermal gradient in the gas temperature induced by the flow of the neutral gas, a careful study of the thermophoretic force on the spatial distribution of the nanoparticle density profiles is indispensable. In the present paper, we mainly focus on the influences of the gas flow rate, voltage, and gas pressure on the spatial distribution of the nanoparticle density. It appears that the resulting density profile of the 10-nm particles experiences a significant shift towards the upper showerhead electrode once the neutral equations are applied, and a serious shift is observed when increasing the gas flow rate. Thus, the flow of neutral gas can strongly influence the spatial distribution of the particles in the plasma. (physics of gases, plasmas, and electric discharges)

  13. Full-dimensional quantum dynamics study of the H2 + C2H → H + C2H2 reaction on an ab initio potential energy surface.

    Chen, Liuyang; Shao, Kejie; Chen, Jun; Yang, Minghui; Zhang, Dong H

    2016-05-21

    This work performs a time-dependent wavepacket study of the H2 + C2H → H + C2H2 reaction on a new ab initio potential energy surface (PES). The PES is constructed using neural network method based on 68 478 geometries with energies calculated at UCCSD(T)-F12a/aug-cc-pVTZ level and covers H2 + C2H↔H + C2H2, H + C2H2 → HCCH2, and HCCH2 radial isomerization reaction regions. The reaction dynamics of H2 + C2H → H + C2H2 are investigated using full-dimensional quantum dynamics method. The initial-state selected reaction probabilities are calculated for reactants in eight vibrational states. The calculated results showed that the H2 vibrational excitation predominantly enhances the reactivity while the excitation of bending mode of C2H slightly inhibits the reaction. The excitations of two stretching modes of C2H molecule have negligible effect on the reactivity. The integral cross section is calculated with J-shift approximation and the mode selectivity in this reaction is discussed. The rate constants over 200-2000 K are calculated and agree well with the experimental measured values. PMID:27208951

  14. Microdomains of High Calcium Are Not Required for Exocytosis in Rbl-2h3 Mucosal Mast Cells

    Mahmoud, Sahar F.; Fewtrell, Clare

    2001-01-01

    We have previously shown that store-associated microdomains of high Ca2+ are not essential for exocytosis in RBL-2H3 mucosal mast cells. We have now examined whether Ca2+ microdomains near the plasma membrane are required, by comparing the secretory responses seen when Ca2+ influx was elicited by two very different mechanisms. In the first, antigen was used to activate the Ca2+ release–activated Ca2+ (CRAC) current (ICRAC) through CRAC channels. In the second, a Ca2+ ionophore was used to tra...

  15. Bonding in Zintl phase hydrides: density functional calculations for SrAlSiH, SrAl2H2, SrGa2H2 and BaGa2H2

    Subedi, Alaska P [ORNL; Singh, David J [ORNL

    2008-01-01

    We investigate the bonding characteristics of SrAlSiH, SrAl{sub 2}H{sub 2}, SrGa{sub 2}H{sub 2}, and BaGa{sub 2}H{sub 2} using density functional calculations. The mixed bonding characteristic of other families of Zintl phases is found, with the formation of covalent sp{sup 2} bonds in the Al/Ga/Al-Si planes of the various compounds. On the other hand the Sr and Ba atoms occur as divalent cations, while the H is anionic. The results indicate that insulating SrSiAlH may be a switchable ferroelectric.

  16. 2H and 13C tracer studies of ethanol metabolism by Fourier transform 13C[2H, 1H] NMR difference spectroscopy

    A novel form of NMR difference spectroscopy has been developed to monitor low levels of deuterium incorporation in steroids resulting from ethanol metabolism. Ethanol specifically labeled with 13C and/or 2H was administered to bile fistula rats, and bile acids were collected, derivatized and separated. Subtracting 13C [1H] spectra from 13C[2H,1H] spectra of such samples, where the brackets imply complete noise decoupling of the indicated nuclei, results in difference spectra. These spectra display 13C resonances only from 13C spins which are J-coupled to 2H spins. Particular sites and extents of 2H incorporation along the steroid skeletons could thus be evaluated and compared with GC-MS analysis. A practical lower limit of approximately 20 nanomoles of 13C--2H couples could be observed using this technique, through use of sample microcells, quadrature detection and long-term signal averaging

  17. Electron swarm parameters in pure C2H2 and in C2H2-Ar mixtures and electron collision cross sections for the C2H2 molecule

    Nakamura, Yoshiharu

    2010-09-01

    Electron swarm parameters (the drift velocity and the longitudinal diffusion coefficient) were measured in pure C2H2 and also in C2H2-Ar mixtures containing 0.517% and 5.06% acetylene over wide E/N ranges. These swarm parameters were analysed using a Boltzmann equation analysis and a set of electron collision cross sections for the C2H2 molecule was derived so that it was consistent with the present swarm data and published ionization coefficient. The present result suggested the presence of a Ramsauer-Townsend minimum in the elastic momentum transfer cross section at 0.08 eV and prominent threshold and resonance peaks in the ν4/ν5 vibrational excitation cross section. The present cross section set was also confirmed to be consistent with the published experimental total cross section of C2H2.

  18. Central nervous system dysfunction in a mouse model of FA2H deficiency.

    Potter, Kathleen A; Kern, Michael J; Fullbright, George; Bielawski, Jacek; Scherer, Steven S; Yum, Sabrina W; Li, Jian J; Cheng, Hua; Han, Xianlin; Venkata, Jagadish Kummetha; Khan, P Akbar Ali; Rohrer, Bärbel; Hama, Hiroko

    2011-07-01

    Fatty acid 2-hydroxylase (FA2H) is responsible for the synthesis of myelin galactolipids containing hydroxy fatty acid (hFA) as the N-acyl chain. Mutations in the FA2H gene cause leukodystrophy, spastic paraplegia, and neurodegeneration with brain iron accumulation. Using the Cre-lox system, we developed two types of mouse mutants, Fa2h(-/-) mice (Fa2h deleted in all cells by germline deletion) and Fa2h(flox/flox) Cnp1-Cre mice (Fa2h deleted only in oligodendrocytes and Schwann cells). We found significant demyelination, profound axonal loss, and abnormally enlarged axons in the CNS of Fa2h(-/-) mice at 12 months of age, while structure and function of peripheral nerves were largely unaffected. Fa2h(-/-) mice also exhibited histological and functional disruption in the cerebellum at 12 months of age. In a time course study, significant deterioration of cerebellar function was first detected at 7 months of age. Further behavioral assessments in water T-maze and Morris water maze tasks revealed significant deficits in spatial learning and memory at 4 months of age. These data suggest that various regions of the CNS are functionally compromised in young adult Fa2h(-/-) mice. The cerebellar deficits in 12-month-old Fa2h(flox/flox) Cnp1-Cre mice were indistinguishable from Fa2h(-/-) mice, indicating that these phenotypes likely stem from the lack of myelin hFA-galactolipids. In contrast, Fa2h(flox/flox) Cnp1-Cre mice did not show reduced performance in water maze tasks, indicating that oligodendrocytes are not involved in the learning and memory deficits found in Fa2h(-/-) mice. These findings provide the first evidence that FA2H has an important function outside of oligodendrocytes in the CNS. PMID:21491498

  19. Transport coefficients for carbon, hydrogen, and the organic mixture C2H3

    Electrical and thermal transport coefficients are calculated for amorphous elemental carbon and hydrogen, using the best available systematic theoretical methods. The density range considered is 10-3g/cm3 less than or equal to rho less than or equal to 106g/cm3 for carbon, and 10-4g/cm3 less than or equal to rho less than or equal to 105g/cm3 for hydrogen. The temperature range considered is 10-2eV less than or equal to kT less than or equal to 104eV. Calculational methods include relativistic partial-wave analysis of the extended Ziman theory, and nonrelativistic plane-wave analysis (Born approximation) of the original Ziman theory. Physical models include relativistic Dirac-Fock-Slater and nonrelativistic Thomas-Fermi-Dirac electron-ion potentials, and one-component-plasma ion-ion structure factors. A mixing algorithm is used to obtain approximate transport coefficients for the atomic ratio C2H3. 10 refs., 31 figs

  20. Environmental, trophic, and ecological factors influencing bone collagen δ2H

    Topalov, Katarina; Schimmelmann, Arndt; David Polly, P.; Sauer, Peter E.; Lowry, Mark

    2013-06-01

    Organic deuterium/hydrogen stable isotope ratios (i.e., 2H/1H, expressed as δ2H value in ‰) in animal tissues are related to the 2H/1H in diet and ingested water. Bone collagen preserves the biochemical 2H/1H isotopic signal in the δ2H value of collagen's non-exchangeable hydrogen. Therefore, δ2H preserved in bone collagen has the potential to constrain environmental and trophic conditions, which is of interest to researchers studying of both living and fossil vertebrates. Our data examine the relationship of δ2H values of collagen with geographic variation in δ2H of meteoric waters, with local variations in the ecology and trophic level of species, and with the transition from mother's milk to adult diet. Based on 97 individuals from 22 marine and terrestrial vertebrates (predominately mammals), we found the relationships of collagen δ2H to both geographic variation in meteoric water δ2H (R2 = 0.55) and to δ15N in bone collagen (R2 = 0.17) statistically significant but weaker than previously reported. The second strongest control on collagen δ2H in our data is dietary, with nearly 50 percent of the variance in δ2H explained by trophic level (R2 = 0.47). Trophic level effects potentially confound the local meteoric signal if not held constant: herbivores tend to have the lowest δ2H values, omnivores have intermediate ones, and carnivores have the highest values. Body size (most likely related to mass-specific metabolic rates) has a strong influence on collagen δ2H (R2 = 0.30), by causing greater sensitivity in smaller animals to seasonal climate variations and/or high evapotranspiration leading to 2H-enrichment in tissues. In marine mammals weaning produces a dramatic effect on collagen δ2H with adult values being universally higher than pup values (R2 = 0.79). Interestingly, the shift in δ15N at weaning is downward, even though normally hydrogen and nitrogen isotope ratios are positively correlated with one another in respect to trophic level. Our

  1. Sepsis does not alter red blood cell glucose metabolism or Na+ concentration: A 2H-, 23Na-NMR study

    The effects of sepsis on intracellular Na+ concentration ([Na+]i) and glucose metabolism were examined in rat red blood cells (RBCs) by using 23Na- and 2H-nuclear magnetic resonance (NMR) spectroscopy. Sepsis was induced in 15 halothane-anesthetized female Sprague-Dawley rats by using the cecal ligation and perforation technique; 14 control rats underwent cecal manipulation without ligation. The animals were fasted for 36 h, but allowed free access to water. At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent. Human RBCs from 17 critically ill nonseptic patients and from 7 patients who were diagnosed as septic were also examined for [Na+]i. Five rat RBC specimens had [Na+]i determined by both 23Na-NMR and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). For glucose metabolism studies, RBCs from septic and control rats were suspended in modified Krebs-Henseleit buffer containing [6,6-2H2]glucose and examined by 2H-NMR. No significant differences in [Na+]i or glucose utilization were found in RBCs from control or septic rats. There were no differences in [Na+]i in the two groups of patients. The [Na+]i determined by NMR spectroscopy agreed closely with measurements using ICP-AES and establish that 100% of the [Na+]i of the RBC is visible by NMR. Glucose measurements determined by 2H-NMR correlated closely (correlation coefficient = 0.93) with enzymatic analysis. These studies showed no evidence that sepsis disturbed RBC membrane function or metabolism

  2. Experimental studies of collisions of excited Li(4p) atoms with C2H4, C2H6, C3H8 and theoretical interpretation of the Li-C2H4 system

    Collisions of excited Li(4p) states with C2H4, C2H6 and C3H8 are studied experimentally using far-wing scattering state spectroscopy techniques. High-level ab initio quantum mechanical studies of the Li-C2H4 system are conducted to explain the results of the experiment for this system. The recent and present works indicate that knowledge of the internal structure of the perturber (C2H4, C2H6 and C3H8) is essential to fully understand the interaction between the metal and the hydrocarbon molecules. The ab initio calculation shows that the Li(4d) (with little probability under the experimental conditions) and the Li(4p) can be formed directly through the laser pumping. It also shows that the Li(4s) and Li(3d) states can be formed through an electronic diabatic coupling involving a radiationless process. However, the Li(3p), Li(3s) and Li(2p) states can only be formed through a secondary diabatic coupling which is a much less probable process than the primary one. The calculation limited to two C2v sections of the potential energy surfaces (PESs) shows peculiar multi-state crossings that we have never seen in other lithium complexes we studied

  3. The role of isovalency in the reactions of the cyano (CN), boron monoxide (BO), silicon nitride (SiN), and ethynyl (C2H) radicals with unsaturated hydrocarbons acetylene (C2H2) and ethylene (C2H4).

    Parker, D S N; Mebel, A M; Kaiser, R I

    2014-04-21

    The classification of chemical reactions based on shared characteristics is at the heart of the chemical sciences, and is well exemplified by Langmuir's concept of isovalency, in which 'two molecular entities with the same number of valence electrons have similar chemistries'. Within this account we further investigate the ramifications of the isovalency of four radicals with the same X(2)Σ(+) electronic structure - cyano (CN), boron monoxide (BO), silicon nitride (SiN), and ethynyl (C2H), and their reactions with simple prototype hydrocarbons acetylene (C2H2) and ethylene (C2H4). The fact that these four reactants own the same X(2)Σ(+) electronic ground state should dictate the outcome of their reactions with prototypical hydrocarbons holding a carbon-carbon triple and double bond. However, we find that other factors come into play, namely, atomic radii, bonding orbital overlaps, and preferential location of the radical site. These doublet radical reactions with simple hydrocarbons play significant roles in extreme environments such as the interstellar medium and planetary atmospheres (CN, SiN and C2H), and combustion flames (C2H, BO). PMID:24418936

  4. Structure, phase transitions, dielectric and spectroscopic studies of the 2-aminopyrimidinium salts: [(2-NH 2C 4N 2H 3) 2H][ClO 4] and [2-NH 2C 4N 2H 4][BF 4

    Czupiński, O.; Wojtaś, M.; Ciunik, Z.; Jakubas, R.

    2006-01-01

    Crystal structure of the 2-aminopyrimidinium derivatives: [(2-NH 2C 4N 2H 3) 2H][ClO 4] (I) and [2-NH 2C 4N 2H 4][BF 4] (II) has been determined at 100 K (I) and 293 K (II) by means of single crystal X-ray diffraction as monoclinic space group, P2/c and P2/n, respectively. The asymmetric part of the unit cell of (I) contains two symmetry independent 2-aminopyrimidine forming one dimeric cation and one disordered perchlorate anion. The structure of (II) consists of 2-aminopyrimidinium cation, [2-NH 2C 4N 2H 4] +, protonated at a pyrimidine ring-N atom and [BF 4] - anion. Differential scanning calorimetry (DSC) on perchlorate derivative ( 1:1), [2-NH 2C 4N 2H 3][ClO 4] (III)—being isomorphic to tetrafluoroborate one (I) at room temperature, reveals two phase transitions of first order: at 250/275 K and 390/410 K (cooling-heating, respectively), whereas the analog (II) only one transition at high temperatures—343/385 K. The dielectric studies in the frequency range 75 kHz - 10 MHz disclose relaxation process at high temperatures in salt (I). Infrared spectra of polycrystalline [2-NH 2C 4N 2H 4][BF 4] have been studied in the temperature range 300-420 K. Substantial changes in the temperature evolution of frequencies of internal modes of the 2-aminopyrimidinium cations and [BF 4] - anions near 390 K are due to the variations in the motion of both moieties and hydrogen bond configuration. The experimental studies indicate that all phase transitions taking place in studied 2-aminopyrimidinium derivatives are classified as an order-disorder.

  5. Dissection and cytological mapping of barley chromosome 2H in the genetic background of common wheat

    Joshi, Giri Prasad; Nasuda, Shuhei; Endo, Takashi R.

    2011-01-01

    We used gametocidal (Gc) chromosomes 2C and 3C[SAT] to dissect barley 2H added to common wheat. The Gc chromosome induces chromosomal breakage resulting in chromosomal aberrations in the progeny of the 2H addition line of common wheat carrying the monosomic Gc chromosome. We conducted in situ hybridization to select plants carrying structurally rearranged aberrant 2H chromosomes and characterized them by sequential C-banding and in situ hybridization. We established 66 dissection lines of com...

  6. The evaluation of 2H(n,2n)1H reaction cross section

    2H(n,2n)p reaction cross section is useful to nuclear power development. All the experimental data of 2H(n,2n)p reaction until 1990 were collected. The original data and errors of all the experiments were analysed and fitted on computer MICRO-VAX-II with orthogonal polynomial. The recommended 2H(n,2n) cross section are presented

  7. Synthesis of 2-substituted 2H-chromenes using potassium vinyltrifluoroborates

    Liu, Fei; Evans, Todd; Das, Bhaskar C.

    2008-01-01

    2H-Chromenes were synthesized from salicylaldehyde using potassium vinylic borates in the presence of secondary amines. We synthesized these 2H-chromene derivatives as a part of an ongoing project to develop inhibitors for TGF-β receptors. Potassium vinyl trifluoroborates react with salicylaldehydes at 80 °C in the presence of a secondary amine and produced 2-substituted 2H-chromene derivatives with a 70–90% yield.

  8. Nuclear reaction analysis of 1H and 2H in hafnium silicate films on Si

    The 1H(15N,αγ)12C and 2H(3He,p)4He nuclear reactions were employed to detect, respectively, 1H and 2H in hafnium silicates films on Si. The methods employed to achieve quantitative analyses are described. Moreover, by performing annealing sequences in vacuum or O2 followed by 1H2 or 2H2, it was observed that the O2-preanneled films incorporate less H, either 1H or 2H. This was explained by O-deficient, H-trapping sites that are eliminated by the O2 preannealing

  9. On the Meshing Efficiency of 2K-2H Type Planetary Gear Reducer

    Long-Chang Hsieh; Hsiu-Chen Tang

    2013-01-01

    This paper proposes 2K-2H type planetary gear reducer and analyzes its meshing efficiency. First, according to the concept of train value equation, the kinematic design of 2K-2H type planetary gear reducers is carried out. Three 2K-2H type planetary gear reducers are designed to illustrate the design algorithm. Then, based on the latent power theorem, the meshing efficiency equation of 2K-2H type planetary gear reducer is derived. According to the meshing efficiency equation, the meshing effi...

  10. Central nervous system dysfunction in a mouse model of FA2H deficiency

    Potter, Kathleen A.; Kern, Michael J.; Fullbright, George; Bielawski, Jacek; Scherer, Steven S.; Yum, Sabrina W.; Li, Jian J.; Cheng, Hua; Han, Xianlin; Venkata, Jagadish Kummetha; Khan, P. Akbar Ali; Rohrer, Bärbel; Hama, Hiroko

    2011-01-01

    Fatty acid 2-hydroxylase (FA2H) is responsible for the synthesis of myelin galactolipids containing hydroxy fatty acid (hFA) as the N-acyl chain. Mutations in the FA2H gene cause leukodystrophy, spastic paraplegia, and neurodegeneration with brain iron accumulation. Using the Cre-lox system, we developed two types of mouse mutants, Fa2h−/− mice (Fa2h deleted in all cells by germline deletion) and Fa2hflox/flox Cnp1-Cre mice (Fa2h deleted only in oligodendrocytes and Schwann cells). We found s...

  11. Calculational and Experimental Investigations of the Pressure Effects on Radical - Radical Cross Combinations Reactions: C2H5 + C2H3

    Fahr, Askar; Halpern, Joshua B.; Tardy, Dwight C.

    2007-01-01

    Pressure-dependent product yields have been experimentally determined for the cross-radical reaction C2H5 + C2H3. These results have been extended by calculations. It is shown that the chemically activated combination adduct, 1-C4H8*, is either stabilized by bimolecular collisions or subject to a variety of unimolecular reactions including cyclizations and decompositions. Therefore the "apparent" combination/disproportionation ratio exhibits a complex pressure dependence. The experimental studies were performed at 298 K and at selected pressures between about 4 Torr (0.5 kPa) and 760 Torr (101 kPa). Ethyl and vinyl radicals were simultaneously produced by 193 nm excimer laser photolysis of C2H5COC2H3 or photolysis of C2H3Br and C2H5COC2H5. Gas chromatograph/mass spectrometry/flame ionization detection (GC/MS/FID) were used to identify and quantify the final reaction products. The major combination reactions at pressures between 500 (66.5 kPa) and 760 Torr are (1c) C2H5 + C2H3 yields 1-butene, (2c) C2H5 + C2H5 yields n-butane, and (3c) C2H3 + C2H3 yields 1,3-butadiene. The major products of the disproportionation reactions are ethane, ethylene, and acetylene. At moderate and lower pressures, secondary products, including propene, propane, isobutene, 2-butene (cis and trans), 1-pentene, 1,4-pentadiene, and 1,5-hexadiene are also observed. Two isomers of C4H6, cyclobutene and/or 1,2-butadiene, were also among the likely products. The pressure-dependent yield of the cross-combination product, 1-butene, was compared to the yield of n-butane, the combination product of reaction (2c), which was found to be independent of pressure over the range of this study. The [ 1-C4H8]/[C4H10] ratio was reduced from approx.1.2 at 760 Torr (101 kPa) to approx.0.5 at 100 Torr (13.3 kPa) and approx.0.1 at pressures lower than about 5 Torr (approx.0.7 kPa). Electronic structure and RRKM calculations were used to simulate both unimolecular and bimolecular processes. The relative importance

  12. Hyperfine excitation of N$_2$H$^+$ by H$_2$: Toward a revision of N$_2$H$^+$ abundance in cold molecular clouds

    Lique, François; Pagani, Laurent; Feautrier, Nicole

    2014-01-01

    The modelling of emission spectra of molecules seen in interstellar clouds requires the knowledge of collisional rate coefficients. Among the commonly observed species, N$_2$H$^+$ is of particular interest since it was shown to be a good probe of the physical conditions of cold molecular clouds. Thus, we have calculated hyperfine-structure resolved excitation rate coefficients of N$_2$H$^+$(X$^1\\Sigma^+$) by H$_2(j=0)$, the most abundant collisional partner in the cold interstellar medium. The calculations are based on a new potential energy surface, obtained from highly correlated {\\it ab initio} calculations. State-to-state rate coefficients between the first hyperfine levels were calculated, for temperatures ranging from 5 K to 70 K. By comparison with previously published N$_2$H$^+$-He rate coefficients, we found significant differences which cannot be reproduced by a simple scaling relationship. As a first application, we also performed radiative transfer calculations, for physical conditions typical of ...

  13. C2H as a PDR tracer: a case study toward the Orion Bar

    Nagy, Z; Van der Tak, F F S; Faure, A; Makai, Z; Bergin, E A

    2014-01-01

    We study the spatial distribution and abundance of C2H in the prototypical high UV-illumination PDR, the Orion Bar. We analyse Herschel/HIFI maps of C2H, CH, and HCO+, and a NANTEN map of [CI]. We interpret the observed C2H emission using the combination of Herschel/HIFI and NANTEN data with radiative transfer and PDR models. Five rotational transitions of C2H (from N=6-5 up to N=10-9) have been detected in the HIFI frequency range toward the CO+ peak of the Orion Bar. Based on the five detected C2H transitions, a rotation diagram analysis gives a rotation temperature of 67 K and a C2H column density of 5x10^13 cm^-2. A non-LTE radiative transfer model with a C2H column density of 10^14 cm^-2, an H2 volume density of 10^6 cm^-3, a kinetic temperature of 400 K, and an electron density of 10 cm^-3 is required to fit the two highest rotational transitions of C2H. This model gives a reasonable fit to the lower-N transitions as well, however, the N=6-5,...,8-7 transitions are more consistent with lower kinetic tem...

  14. Hot-Pressing Effects on Polymer Electrolyte Membrane Investigated by 2H NMR Spectroscopy

    The structural change of Nafion polymer electrolyte membrane (PEM) induced by hot-pressing, which is one of the representative procedures for preparing membrane-electrode-assembly for low temperature fuel cells, was investigated by 2H nuclear magnetic resonance (NMR) spectroscopy. The hydrophilic channels were asymmetrically flattened and more aligned in the membrane plane than along the hot-pressing direction. The average O-2H director of 2H2O in polymer electrolyte membrane was employed to extract the structural information from the 2H NMR peak splitting data. The dependence of 2H NMR data on water contents was systematically analyzed for the first time. The approach presented here can be used to understand the chemicals' behavior in nano-spaces, especially those reshaping and functioning interactively with the chemicals in the wet and/or mixed state

  15. Structural, elastic and electronic properties of 2H- and 4H-SiC

    Md. Nuruzzaman

    2015-05-01

    Full Text Available The structural, five different elastic constants and electronic properties of 2H- and 4H-Silicon carbide (SiC are investigated by using density functional theory (DFT. The total energies of primitive cells of 2H- and 4H-SiC phases are close to each other and moreover satisfy the condition E2H >E4H . Thus, the 4H-SiC structure appears to be more stable than the 2H- one. The analysis of elastic properties also indicates that the 4H-SiC polytype is stiffer than the 2H structures. The electronic energy bands, the total density of states (DOS are calculated. The fully relaxed and isotropic bulk modulus is also estimated. The implication of the comparison of our results with the existing experimental and theoretical studies is made.

  16. The transcriptional regulator c2h2 accelerates mushroom formation in Agaricus bisporus.

    Pelkmans, Jordi F; Vos, Aurin M; Scholtmeijer, Karin; Hendrix, Ed; Baars, Johan J P; Gehrmann, Thies; Reinders, Marcel J T; Lugones, Luis G; Wösten, Han A B

    2016-08-01

    The Cys2His2 zinc finger protein gene c2h2 of Schizophyllum commune is involved in mushroom formation. Its inactivation results in a strain that is arrested at the stage of aggregate formation. In this study, the c2h2 orthologue of Agaricus bisporus was over-expressed in this white button mushroom forming basidiomycete using Agrobacterium-mediated transformation. Morphology, cap expansion rate, and total number and biomass of mushrooms were not affected by over-expression of c2h2. However, yield per day of the c2h2 over-expression strains peaked 1 day earlier. These data and expression analysis indicate that C2H2 impacts timing of mushroom formation at an early stage of development, making its encoding gene a target for breeding of commercial mushroom strains. PMID:27207144

  17. Hydrogen bridging in the compounds X2H (X=Al,Si,P,S)

    Owens, Zachary T.; Larkin, Joseph D.; Schaefer, Henry F.

    2006-10-01

    X2H hydrides (X =Al, Si, P, and S) have been investigated using coupled cluster theory with single, double, and triple excitations, the latter incorporated as a perturbative correction [CCSD(T)]. These were performed utilizing a series of correlation-consistent basis sets augmented with diffuse functions (aug-cc-pVXZ, X =D, T, and Q). Al2H and Si2H are determined to have H-bridged C2v structures in their ground states: the Al2H ground state is of B12 symmetry with an Al-H-Al angle of 87.6°, and the Si2H ground state is of A12 symmetry with a Si-H-Si angle of 79.8°. However, P2H and S2H have nonbridged, bent Cs structures: the P2H ground state is of A'2 symmetry with a P-P-H angle of 97.0°, and the S2H ground state is of A'2 symmetry with a S-S-H angle of 93.2°. Ground state geometries, vibrational frequencies, and electron affinities have been computed at all levels of theory. Our CCSD(T)/aug-cc-pVQZ adiabatic electron affinity of 2.34eV for the Si2H radical is in excellent agreement with the photoelectron spectroscopy experiments of Xu et al. [J. Chem. Phys. 108, 7645 (1998)], where the electron affinity was determined to be 2.31±0.01eV.

  18. Band structure and optical response of 2H-Mo X2 compounds ( X=S , Se, and Te)

    Reshak, Ali Hussain; Auluck, Sushil

    2005-04-01

    We report calculations of the electronic and optical properties for the 2H-MoX2 (X=S,Se,Te) compounds using the full potential linear augmented plane wave method within the local density approximation. When S is replaced by Se and Te, the energy gap changes and the bandwidth of the Mo-d bands reduces. From the partial density of states we find a strong hybridization between Mo-d and X-p states below the Fermi energy EF . On going from S to Se to Te the structures in the frequency-dependent imaginary part of the dielectric function ɛ2(ω) shifts towards lower energies. The frequency-dependent reflectivity and absorption show that the plasma minimum also shifts towards lower energies. We compare our calculations with the experimental optical data and find a good agreement.

  19. Reactive scattering of carbon atoms: the reaction dynamics of C(3P, 1D) +C2H2 and C2H4

    The reaction dynamics of C(3P, 1D) with acetylene and ethylene have been investigated by using the crossed beam technique with mass spectrometric detection and time-of-flight (TOF) analysis. The novel capability of generating continuous supersonic beams of carbon atoms by a radio-frequency discharge beam source is exploited. From angular and velocity distribution measurements, the primary reaction products are identified, their relative importance assessed, and their dynamics of formation characterized. While the reaction C(3P) + C2H2(X1Σg+) has been found to lead to C3H + H and C3(X1Σg+) + H2(X1Σg+) in comparable amount, the reaction C(3P) + C2H4(X1At) has been found to lead, predominantly, to H + C3H3 (propargylene). The dynamics of the C(1D) reactions are also characterized. The spin-forbidden H2 elimination channel in the reaction C(3P) + C2H2 is attributed to the occurrence of inter-system-crossing between the triplet and singlet manifold of the C3H2 potential energy surfaces. Interestingly, these findings provide evidence that the C(3P) + C2H2 reaction maybe the source of both C3H and C3 species detected in the extreme environment of dense interstellar clouds and outflows of carbon stars, as well as in combustion systems. (author)

  20. SMA observations of C2H in High-Mass Star Forming Regions

    Jiang, Xue-Jian; Zhang, Qizhou; Wang, Junzhi; Zhang, Zhi-Yu; Li, Juan; Gao, Yu; Gu, Qiusheng

    2015-01-01

    C$_2$H is a representative hydrocarbon that is abundant and ubiquitous in the interstellar medium (ISM). To study its chemical properties, we present Submillimeter Array (SMA) observations of the C$_2$H $N=3-2$ and HC$_3$N $J=30-29$ transitions and the 1.1 mm continuum emission toward four OB cluster-forming regions, AFGL 490, ON 1, W33 Main, and G10.6-0.4, which cover a bolometric luminosity range of $\\sim$10$^3$--10$^6$ $L_{\\odot}$. We found that on large scales, the C$_2$H emission traces the dense molecular envelope. However, for all observed sources, the peaks of C$_2$H emission are offset by several times times 10$^4$ AU from the peaks of 1.1 mm continuum emission, where the most luminous stars are located. By comparing the distribution and profiles of C$_2$H hyperfine lines and the 1.1 mm continuum emission, we find that the C$_2$H column density (and abundance) around the 1.1 mm continuum peaks is lower than those in the ambient gas envelope. Chemical models suggest that C$_2$H might be transformed to...

  1. Chromatin remodeling enzyme Snf2h regulates embryonic lens differentiation and denucleation.

    He, Shuying; Limi, Saima; McGreal, Rebecca S; Xie, Qing; Brennan, Lisa A; Kantorow, Wanda Lee; Kokavec, Juraj; Majumdar, Romit; Hou, Harry; Edelmann, Winfried; Liu, Wei; Ashery-Padan, Ruth; Zavadil, Jiri; Kantorow, Marc; Skoultchi, Arthur I; Stopka, Tomas; Cvekl, Ales

    2016-06-01

    Ocular lens morphogenesis is a model for investigating mechanisms of cellular differentiation, spatial and temporal gene expression control, and chromatin regulation. Brg1 (Smarca4) and Snf2h (Smarca5) are catalytic subunits of distinct ATP-dependent chromatin remodeling complexes implicated in transcriptional regulation. Previous studies have shown that Brg1 regulates both lens fiber cell differentiation and organized degradation of their nuclei (denucleation). Here, we employed a conditional Snf2h(flox) mouse model to probe the cellular and molecular mechanisms of lens formation. Depletion of Snf2h induces premature and expanded differentiation of lens precursor cells forming the lens vesicle, implicating Snf2h as a key regulator of lens vesicle polarity through spatial control of Prox1, Jag1, p27(Kip1) (Cdkn1b) and p57(Kip2) (Cdkn1c) gene expression. The abnormal Snf2h(-/-) fiber cells also retain their nuclei. RNA profiling of Snf2h(-/) (-) and Brg1(-/-) eyes revealed differences in multiple transcripts, including prominent downregulation of those encoding Hsf4 and DNase IIβ, which are implicated in the denucleation process. In summary, our data suggest that Snf2h is essential for the establishment of lens vesicle polarity, partitioning of prospective lens epithelial and fiber cell compartments, lens fiber cell differentiation, and lens fiber cell nuclear degradation. PMID:27246713

  2. Trends and variations in CO, C2H6, and HCN in the Southern Hemisphere point to the declining anthropogenic emissions of CO and C2H6

    N. B. Jones

    2012-08-01

    Full Text Available We analyse the carbon monoxide (CO, ethane (C2H6 and hydrogen cyanide (HCN partial columns (from the ground to 12 km derived from measurements by ground-based solar Fourier Transform Spectroscopy at Lauder, New Zealand (45° S, 170° E, and at Arrival Heights, Antarctica (78° S, 167° E, from 1997 to 2009. Significant negative trends are calculated for all species at both locations, based on the daily-mean observed time series, namely CO (−0.94 ± 0.47% yr−1, C2H6 (−2.37 ± 1.18% yr−1 and HCN (−0.93 ± 0.47% yr−1 at Lauder and CO (−0.92 ± 0.46% yr−1, C2H6 (−2.82 ± 1.37% yr−1 and HCN (−1.41 ± 0.71% yr−1 at Arrival Heights. The uncertainties reflect the 95% confidence limits. However, the magnitudes of the trends are influenced by the anomaly associated with the 1997–1998 El Niño Southern Oscillation event at the beginning of the time series reported. We calculate trends for each month from 1997 to 2009 and find negative trends for all months. The largest monthly trends of CO and C2H6 at Lauder, and to a lesser degree at Arrival Heights, occur during austral spring during the Southern Hemisphere tropical and subtropical biomass burning period. For HCN, the largest monthly trends occur in July and August at Lauder and around November at Arrival Heights. The correlations between CO and C2H6 and between CO and HCN at Lauder in September to November, when the biomass burning maximizes, are significantly larger that those in other seasons. A tropospheric chemistry-climate model is used to simulate CO, C2H6, and HCN partial columns for the period of 1997–2009, using interannually varying biomass burning emissions from GFED3 and annually periodic but seasonally varying emissions from both biogenic and anthropogenic sources. The model-simulated partial columns of these species compare well with the measured partial columns and the model accurately reproduces seasonal cycles of all three species at both locations. However

  3. Optical emission spectroscopy study of premixed C2H4/O2 and C2H4/C2H2/O2 flames for diamond growth with and without CO2 laser excitation

    He, X. N.; Gebre, T.; Shen, X. K.; Xie, Z. Q.; Zhou, Y. S.; Lu, Y. F.

    2010-02-01

    Optical emission spectroscopy (OES) measurements were carried out to study premixed C2H4/O2 and C2H4/C2H2/O2 combustion flame for diamond deposition with and without a CO2 laser excitation. Strong emissions from radicals C2 and CH were observed in the visible range in all the OES spectra acquired. By adding a continuous-wave CO2 laser to irradiate the flame at a wavelength of 10.591 μm, the common CO2 laser wavelength, it was discovered that the emission intensities of the C2 and CH radicals were increased due to the laser beam induced excitation. OES measurements of the C2 and CH radicals were performed using different gas combinations and laser powers. The rotational temperatures in the flame were determined by analyzing the spectra of the R-branch of the A2Δ-->X2Π (0, 0) electronic transition near 430 nm (CH band head). Information obtained from the OES spectra, including the emission intensities of the C2 and CH radicals, the intensity ratios, and the rotational temperatures, was integrated into the study of diamond deposition on tungsten carbide substrates for mechanism analysis of the laser induced vibrational excitation and laser-assisted diamond deposition.

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

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

    2014-04-20

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

  5. Stress corrosion cracking of 13Cr steels in CO2-H2S-Cl- environments

    SCC behavior of two type 13Cr steels was investigated in aqueous CO2/H2S environments. The 13Cr steels were less resistant to SCC in CO2/H2S environments than low alloy steels, but some 13Cr steels were not subject to SCC even at a hydrogen sulfide partial pressure of 0.3 atm. Further, it was found that SCC in a CO2/H2S environment was caused by hydrogen embrittlement and that the SCC susceptibility of 13Cr steels was affected by their intergranular cracking behavior. Thus, their microstructures and carbide dispersions are important factors to SCC susceptibility of 13Cr steels

  6. Determination of the delta(2H/1H)of Water: RSIL Lab Code 1574

    Revesz, Kinga; Coplen, Tyler B.

    2008-01-01

    Reston Stable Isotope Laboratory (RSIL) lab code 1574 describes a method used to determine the relative hydrogen isotope-ratio delta(2H,1H), abbreviated hereafter as d2H of water. The d2H measurement of water also is a component of the National Water Quality Laboratory (NWQL) schedules 1142 and 1172. The water is collected unfiltered in a 60-mL glass bottle and capped with a Polyseal cap. In the laboratory, the water sample is equilibrated with gaseous hydrogen using a platinum catalyst (Horita, 1988; Horita and others, 1989; Coplen and others, 1991). The reaction for the exchange of one hydrogen atom is shown in equation 1.

  7. Experimental and kinetic modeling study of C2H4 oxidation at high pressure

    Lopez, Jorge Gimenez; Rasmussen, Christian Lund; Alzueta, Maria;

    2009-01-01

    A detailed chemical kinetic model for oxidation of C2H4 in the intermediate temperature range and high pressure has been developed and validated experimentally. New ab initio calculations and RRKM analysis of the important C2H3 + O-2 reaction was used to obtain rate coefficients over a wide range...... bar, varying the reaction stoichiometry from very lean to fuel-rich conditions. Model predictions are generally satisfactory. The governing reaction mechanisms are outlined based on calculations with the kinetic model. Under the investigated conditions the oxidation pathways for C2H4 are more complex...

  8. One-step fabrication of nickel nanocones by electrodeposition using CaCl2·2H2O as capping reagent

    Lee, Jae Min; Jung, Kyung Kuk; Lee, Sung Ho; Ko, Jong Soo

    2016-04-01

    In this research, a method for the fabrication of nickel nanocones through the addition of CaCl2·2H2O to an electrodeposition solution was proposed. When electrodeposition was performed after CaCl2·2H2O addition, precipitation of the Ni ions onto the (2 0 0) crystal face was suppressed and anisotropic growth of the nickel electrodeposited structures was promoted. Sharper nanocones were produced with increasing concentration of CaCl2·2H2O added to the solution. Moreover, when temperature of the electrodeposition solutions approached 60 °C, the apex angle of the nanostructures decreased. In addition, the nanocones produced were applied to superhydrophobic surface modification using a plasma-polymerized fluorocarbon (PPFC) coating. When the solution temperature was maintained at 60 °C and the concentration of the added CaCl2·2H2O was 1.2 M or higher, the fabricated samples showed superhydrophobic surface properties. The proposed nickel nanocone formation method can be applied to various industrial fields that require metal nanocones, including superhydrophobic surface modification.

  9. Calculation of dissociating autoionizing states using the block diagonalization method: Application to N2H

    We report the calculation of preliminary potential surfaces necessary to treat dissociative recombination (DR) of electrons with N2H+. We performed multi-reference, configuration interaction calculations with a large active space for N2H+ and N2H, using the GAMESS electronic structure code. Rydberg-valence coupling is strong in N2H, and a systematic procedure is desirable to isolate the appropriate dissociating, autoionizing states. We used the block diagonalization method, which requires only modest additional effort beyond the standard methodology. We treated both linear and bent geometries of the molecules, with N2 fixed at its equilibrium separation. The results indicate that the crossing between the dissociating neutral curve and the initial ion potential is not favorably located, suggesting that the direct mechanism for DR will be small. Dynamics calculations using the multi-configuration, time-dependent Hartree (MCTDH) method confirm this conclusion.

  10. Deuterium MR in vivo imaging of the rat eye using 2H2O

    In vivo deuterium MR imaging (2H MR) was investigated in rats after intraperitoneal administration of deuterated saline, and a dynamic study of the water movement in rat eyes was performed. Deuterium MR imaging was carried out by means of a gradient-echo (GRE) and a spin-echo (SE) pulse sequence. The rat eye was imaged in 2H MR more selectively by SE than by GRE, but a lower signal-to-noise ratio was obtained in 2H MR imaging using the SE sequence. The MR signal intensity of the rat eye was followed by a 3-compartment model, which enabled determination of the flow rate constant of the water in the eye (0.359/min). Deuterium MR imaging is useful to visualize the dynamic change of water in rat eyes using 2H MR at the same magnetic field (2 T) that can also be used for conventional MR imaging in humans. (orig.)

  11. Structural, mechanical, and electronic properties of monoclinic N2H5N3 under pressure

    Structural, elastic, mechanical, and electronic properties of monoclinic N2H5N3 at zero and high pressure have been investigated using the plane-wave ultrasoft pseudopotential method within the density-functional theory (DFT). The pressure dependences of structural parameters, elastic constants, mechanical properties, band gaps, and density of states of monoclinic N2H5N3 have been calculated and discussed. The obtained results show that monoclinic N2H5N3 is unstable at pressures exceeding the value 126.1 GPa. The ratio of B/G and the Cauchy’s pressure indicate that monoclinic N2H5N3 behaves in ductile nature with pressure ranging from 0 to 200 GPa. (author)

  12. Rings of C2H in the Molecular Disks Orbiting TW Hya and V4046 Sgr

    Kastner, J H; Gorti, U; Hily-Blant, P; Oberg, K; Forveille, T; Andrews, S; Wilner, D

    2015-01-01

    We have used the Submillimeter Array to image, at ~1" resolution, C2H(3-2) emission from the molecule-rich circumstellar disks orbiting the nearby, classical T Tauri star systems TW Hya and V4046 Sgr. The SMA imaging reveals that the C2H emission exhibits a ring-like morphology within each disk, the inner hole radius of the C2H ring within the V4046 Sgr disk (~70 AU) is somewhat larger than than of its counterpart within the TW Hya disk (~45 AU). We suggest that, in each case, the C2H emission likely traces irradiation of the tenuous surface layers of the outer disks by high-energy photons from the central stars.

  13. Adsorption geometry of PTCDA on 2H-NbSe2

    Low-temperature scanning tunnelling microscopy of submonolayers of PTCDA adsorbed on 2H-NbSe2 reveals an adsorbate layer that is neither commensurate with the substrate lattice nor with the charge density wave periodicity. The observed smallness of deviations from the PTCDA bulk-state unit-cell dimensions indicates that PTCDA film formation is dominated by intermolecular interactions rather than by interaction between PTCDA and 2H-NbSe2. (orig.)

  14. Direct Experimental Verification of Neutron Acceleration by the Material Optical Potential of Solid 2H2

    We have measured the acceleration of neutrons by the material optical potential of solid 2H2. Using a gravitational spectrometer, we find a minimal kinetic energy Ec=(99±7) neV of neutrons from a superthermal ultracold neutron (UCN) source with solid 2H2 as an UCN converter. The result is in excellent agreement with theoretical predictions, Ec=106 neV

  15. A Forward Chemical Screen Using Zebrafish Embryos with Novel 2-Substituted 2H-Chromene Derivatives

    Torregroza, Ingrid; Evans, Todd; Das, Bhaskar C.

    2009-01-01

    We synthesized 2-substituted 2H-chromene derivatives from salicylaldehyde using potassium vinylic borates in the presence of secondary amines. Our goal was to generate novel compounds that might modulate transforming growth factor-β signaling, based on limited rational design. Potassium vinyl trifluoroborates react with salicylaldehydes at 80 °C in the presence of a secondary amine and produce 2-substituted 2H-chromene derivatives with a 70–90% yield. A small library of these compounds, predi...

  16. Lewis acid Mediated Aza-Diels-Alder Reactions and Asymmetric Alkylations of 2H-azirines

    Risberg, Erik

    2004-01-01

    This thesis describes the use of 2H-azirines, three-membered unsaturatednitrogen-containing heterocycles, as reactive intermediates ina number of Lewis acid promoted alkylations and Diels-Alderreactions providing synthetically useful aziridines. In order to carry out this investigation a new generalprocedure for the ring closure of vinyl azides, forming theresultant 3-substituted-2H-azirines, was developed applying low boiling solventsin closed reaction vessels at elevated temperatures. The a...

  17. Broad N2H+ emission towards the protostellar shock L1157-B1

    Codella, C; Ceccarelli, C; Lefloch, B; Benedettini, M; Busquet, G; Caselli, P; Fontani, F; Gómez-Ruiz, A; Podio, L; Vasta, M

    2013-01-01

    We present the first detection of N2H+ towards a low-mass protostellar outflow, namely the L1157-B1 shock, at about 0.1 pc from the protostellar cocoon. The detection was obtained with the IRAM 30-m antenna. We observed emission at 93 GHz due to the J = 1-0 hyperfine lines. The analysis of the emission coupled with the HIFI CHESS multiline CO observations leads to the conclusion that the observed N2H+(1-0) line originates from the dense (> 10^5 cm-3) gas associated with the large (20-25 arcsec) cavities opened by the protostellar wind. We find a N2H+ column density of few 10^12 cm-2 corresponding to an abundance of (2-8) 10^-9. The N2H+ abundance can be matched by a model of quiescent gas evolved for more than 10^4 yr, i.e. for more than the shock kinematical age (about 2000 yr). Modelling of C-shocks confirms that the abundance of N2H+ is not increased by the passage of the shock. In summary, N2H+ is a fossil record of the pre-shock gas, formed when the density of the gas was around 10^4 cm-3, and then furth...

  18. Investigation on the Interactions of NiCR and NiCR-2H with DNA

    Chitranshi, Priyanka; Chen, Chang-Nan; Jones, Patrick R.; Faridi, Jesika S.; Xue, Liang

    2010-01-01

    We report here a biophysical and biochemical approach to determine the differences in interactions of NiCR and NiCR-2H with DNA. Our goal is to determine whether such interactions are responsible for the recently observed differences in their cytotoxicity toward MCF-7 cancer cells. Viscosity measurement and fluorescence displacement titration indicated that both NiCR and NiCR-2H bind weakly to duplex DNA in the grooves. The coordination of NiCR-2H with the N-7 of 2′-deoxyguanosine 5′-monophosphate (5′-dGMP) is stronger than that of NiCR as determined by 1H NMR. NiCR-2H, like NiCR, can selectively oxidize guanines present in distinctive DNA structures (e.g., bulges), and notably, NiCR-2H oxidizes guanines more efficiently than NiCR. In addition, UV and 1H NMR studies revealed that NiCR is oxidized into NiCR-2H in the presence of KHSO5 at low molar ratios with respect to NiCR (≤4). PMID:20671951

  19. Resolved Depletion Zones and Spatial Differentiation of N2H+ and N2D+

    Tobin, John J; Hartmann, Lee; Lee, Jeong-Eun; Maret, Sebastien; Myers, Phillip C; Looney, Leslie W; Chiang, Hsin-Fang; Friesen, Rachel

    2013-01-01

    We present a study on the spatial distribution of N2D+ and N2H+ in thirteen protostellar systems. Eight of thirteen objects observed with the IRAM 30m telescope show relative offsets between the peak N2D+ (J=2-1) and N2H+ (J=1-0) emission. We highlight the case of L1157 using interferometric observations from the Submillimeter Array and Plateau de Bure Interferometer of the N2D+ (J=3-2) and N2H+ (J=1-0) transitions respectively. Depletion of N2D+ in L1157 is clearly observed inside a radius of ~2000 AU (7") and the N2H+ emission is resolved into two peaks at radii of ~1000 AU (3.5"), inside the depletion region of N2D+. Chemical models predict a depletion zone in N2H+ and N2D+ due to destruction of H2D+ at T ~ 20 K and the evaporation of CO off dust grains at the same temperature. However, the abundance offsets of 1000 AU between the two species are not reproduced by chemical models, including a model that follows the infall of the protostellar envelope. The average abundance ratios of N2D+ to N2H+ have been ...

  20. H2-H2O-HI Hydrogen Separation in H2-H2O-HI Gaseous Mixture Using the Silica Membrane

    It was evaluated aiming at the application for hydrogen iodide decomposition in the thermochemical lS process. Porous alumina tube having pore size of 0.1 μm was modified by chemical vapor deposition using tetraethoxysilane. The permeance single gas of He, H2, and N2 was measured at 300-600 oC. Hydrogen permeance of the modified membrane at a permeation temperature of 600 oC was about 5.22 x 10-08 mol/Pa m2 s, and 3.2 x 10-09 of using gas mixture of H2-H2O-HI, where as HI permeances was below 1 x 10-10 mol/Pa m2 s. The Hydrogen permeance relative was not changed after 25 hours exposure in a mixture of H2-H2O-HI gas at the temperature of 450 oC. (author)

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

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

    2012-11-20

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

  2. Isolation and purification of BVⅠ-2H from bee venom and analysis of its biological action

    2002-01-01

    The medical use of bee venom for rheumatoid arthritis ( RA ) has a very long tradition. In this study, isolation and purification of polypeptides from bee venom were carried out on sephadex chromatography, heparin sepharose CL-6B chromatography and HPLC. Several fractions were extracted, and their effects on activation of splenocyte and THP-1 cell were studied. The inhibitory fraction was selected for further studies. Finally, BVⅠ-2H that the HPLC elution profiles was a single peak was isolated by C8 column. ESI- MS detection results showed that BVⅠ-2H was a fraction of bee venom, and the molecular weight of the major component was 644.8. BVⅠ-2H could inhibit ConA-induced splenocyte proliferation, IL-1 production and interfere with splenocyte cycle in mice. Moreover, BVⅠ-2H could inhibit PMA-induced TNFα production in THP-1 cells, which was due to its inhibitory effects on TNFα mRNA expression and protein phosphorylation of IκBα. Our studies indicated that BVⅠ-2H was one of the anti-inflammatory components of bee venom.

  3. Drivers of δ2H variations in an idealized extratropical cyclone

    Dütsch, Marina; Pfahl, Stephan; Wernli, Heini

    2016-05-01

    Numerical model simulations of stable water isotopes help to improve our understanding of the complex processes driving isotopic variability in atmospheric moisture. We use the isotope-enabled Consortium for Small-Scale Modelling (COSMO) model to study the governing mechanisms of δ2H variations in an idealized extratropical cyclone. A set of experiments with differing initial conditions of δ2H in vapor and partly deactivated isotopic fractionation allows us to quantify the relative roles of cloud fractionation and vertical and horizontal advection for the simulated δ2H signals associated with the cyclone and fronts. Horizontal transport determines the large-scale pattern of δ2H in both vapor and precipitation, while fractionation and vertical transport are more important on a smaller scale, near the fronts. During the passage of the cold front fractionation leads to a V-shaped trend of δ2H in precipitation and vapor, which is, for vapor, superimposed on a gradual decrease caused by the arrival of colder air masses.

  4. Ethynyl (C2H) in massive star formation: Tracing the initial conditions?

    Beuther, H; Henning, T; Linz, H

    2008-01-01

    APEX single-dish observations at sub-millimeter wavelengths toward a sample of massive star-forming regions reveal that C2H is almost omni-present toward all covered evolutionary stages from Infrared Dark Clouds via High-Mass Protostellar Objects to Ultracompact HII regions. High-resolution data from the Submillimeter Array toward one hot-core like High-Mass Protostellar Object show a shell-like distribution of C2H with a radius of ~9000AU around the central submm peak position. These observed features are well reproduced by a 1D cloud model with power-law density and temperature distributions and a gas-grain chemical network. The reactive C2H radical (ethynyl) is abundant from the onset of massive star formation, but later it is rapidly transformed to other molecules in the core center. In the outer cloud regions the abundance of C2H remains high due to constant replenishment of elemental carbon from CO being dissociated by the interstellar UV photons. We suggest that C2H may be a molecule well suited to stu...

  5. A Novel Orange Juice Concentration Method Based on C2H4 Clathrate Hydrate Formation

    Shifeng Li

    2014-06-01

    Full Text Available A novel orange juice concentration method by C2H4 hydrate formation was presented. The experiments were carried out in a high-pressure stirred reactor. The changes of temperature and pressure during C2H4 hydrate formation were discussed under different pressure (2.10 and 4.43 MPa. Dehydration ratio was defined in order to evaluate the separation efficiency. It was found that secondary nucleation happened under higher initial pressure. The dehydration ratios were 20.2 and 99.3% with initial pressure at 2.10 and 4.43 MPa, respectively. The results demonstrated that removal of water by formation of C2H4 hydrate is a potential technology for orange juice concentration.

  6. Natural 4-Hydroxy-2,5-dimethyl-3(2H-furanone (Furaneol®

    Wilfried Schwab

    2013-06-01

    Full Text Available 4-Hydroxy-2,5-dimethyl-3(2H-furanone (HDMF, furaneol® and its methyl ether 2,5-dimethyl-4-methoxy-3(2H-furanone (DMMF are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.

  7. Hydrogenation-induced atomic stripes on the 2 H -MoS2 surface

    Han, Sang Wook; Yun, Won Seok; Lee, J. D.; Hwang, Y. H.; Baik, J.; Shin, H. J.; Lee, Wang G.; Park, Young S.; Kim, Kwang S.

    2015-12-01

    We report that the hydrogenation of a single crystal 2 H -MoS2 induces a novel-intermediate phase between 2H and 1T phases on its surface, i.e., the large-area, uniform, robust, and surface array of atomic stripes through the intralayer atomic-plane gliding. The total energy calculations confirm that the hydrogenation-induced atomic stripes are energetically most stable on the MoS2 surface between the semiconducting 2H and metallic 1T phase. Furthermore, the electronic states associated with the hydrogen ions, which is bonded to sulfur anions on both sides of the MoS2 surface layer, appear in the vicinity of the Fermi level (EF) and reduces the band gap. This is promising in developing the monolayer-based field-effect transistor or vanishing the Schottky barrier for practical applications.

  8. A SAS2H/KENO-V Methodology for 3D Full Core depletion analysis

    This paper describes the use of a SAS2H/KENO-V methodology for 3D full core depletion analysis and illustrates its capabilities by applying it to burnup analysis of the IRIS core benchmarks. This new SAS2H/KENO-V sequence combines a 3D Monte Carlo full core calculation of node power distribution and a 1D Wigner-Seitz equivalent cell transport method for independent depletion calculation of each of the nodes. This approach reduces by more than an order of magnitude the time required for getting comparable results using the MOCUP code system. The SAS2H/KENO-V results for the asymmetric IRIS core benchmark are in good agreement with the results of the ALPHA/PHOENIX/ANC code system. (author)

  9. New coordination modes in potassium edta salts: K2[H2edta]2H2O, K3[Hedta]2H2O and K4[edta]·3.92H2O.

    Krawczyk, Monika K; Lis, Tadeusz

    2011-07-01

    Three potassium edta (edta is ethylenediaminetetraacetic acid, H(4)Y) salts which have different degrees of ionization of the edta anion, namely dipotassium 2-({2-[bis(carboxylatomethyl)azaniumyl]ethyl}(carboxylatomethyl)azaniumyl)acetate dihydrate, 2K(+)·C(10)H(14)N(2)O(8)(2-)·2H(2)O, (I), tripotassium 2,2'-({2-[bis(carboxylatomethyl)amino]ethyl}ammonio)diacetate dihydrate, 3K(+)·C(10)H(13)N(2)O(8)(3-)·2H(2)O, (II), and tetrapotassium 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetate 3.92-hydrate, 4K(+)·C(10)H(12)N(2)O(8)(4-)·3.92H(2)O, (III), were obtained in crystalline form from water solutions after mixing edta with potassium hydroxide in different molar ratios. In (II), a new mode of coordination of the edta anion to the metal is observed. The HY(3-) anion contains one deprotonated N atom coordinated to K(+) and the second N atom is involved in intramolecular bifurcated N-H···O and N-H···N hydrogen bonds. The overall conformation of the HY(3-) anions is very similar to that of the Y(4-) anions in (III), although a slightly different spatial arrangement of the -CH(2)COO(-) groups in relation to (III) is observed, whereas the H(2)Y(2-) anions in (I) adopt a distinctly different geometry. The preferred synclinal conformation of the -NCH(2)CH(2)N- moiety was found for all edta anions. In all three crystals, the anions and water molecules are arranged in three-dimensional networks linked via O-H···O and C-H···O [and N-H···O in (I) and (II)] hydrogen bonds. K···O interactions also contribute to the three-dimensional polymeric architecture of the salts. PMID:21727627

  10. On-board electric vehicle battery charger with enhanced V2H operation mode

    Monteiro, Vítor Duarte Fernandes; Exposto, Bruno Fernandes; Pinto, J. G.; Almeida, Raul Fernando Silva; João C. Ferreira; Meléndez, Andrés A. Nogueiras; João L Afonso

    2014-01-01

    This paper proposes an on-board Electric Vehicle (EV) battery charger with enhanced Vehicle-to-Home (V2H) operation mode. For such purpose was adapted an on-board bidirectional battery charger prototype to allow the Grid-to-Vehicle (G2V), Vehicle-to-Grid (V2G) and V2H operation modes. Along the paper are presented the hardware topology and the control algorithms of this battery charger. The idea underlying to this paper is the operation of the on-board bidirectional ba...

  11. 4-Methyl-2-oxo-2H-chromen-7-yl 4-methoxybenzenesulfonate

    Suman Sinha

    2011-12-01

    Full Text Available In the title compound, C17H14O6S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.016 (1 Å. The dihedral angle between the 2H-chromene and the benzene rings is 54.61 (5°. The C atom of the methoxy group is close to coplanar with its attached ring [deviation = 0.082 (2 Å]. In the crystal, molecules are connected via C—H...O hydrogen bonds, forming sheets lying parallel to the bc plane. Weak C—H...π interactions are also observed.

  12. Effects of structural modulations on the quasiparticle distribution in 2H-TaSe{sub 2}

    Haenke, Torben; Kordyuk, Alexander; Zabolotnyy, Volodymyr; Evtushinsky, Daniil; Sass, Paul; Hess, Christian; Borisenko, Sergey; Buechner, Bernd [IFW Dresden, Institute for Solid State Research, P.O. Box 270116, D-01171 Dresden (Germany); Berger, Helmut [Institut de Physique Appliquee, EPF, 1015 Lausanne (Switzerland)

    2009-07-01

    We report on a temperature dependent scanning tunneling microscopy (STM) and angle resolved photoemission (ARPES) study of the Cu intercalated dichalcogenide 2H-TaSe{sub 2}. The Cu intercalation leads not only to a lowering of the transition temperature into the commensurate charge-density wave state (CDW) but also to the formation of a {radical}(13) x {radical}(13) superstructure, previously observed for the 1T polytype only. The origin, spectroscopic appearance, and influence of these superstructures on the electronic properties of 2H-TaSe{sub 2} are discussed.

  13. Effects of structural modulations on the quasiparticle distribution in 2H-TaSe2

    We report on a temperature dependent scanning tunneling microscopy (STM) and angle resolved photoemission (ARPES) study of the Cu intercalated dichalcogenide 2H-TaSe2. The Cu intercalation leads not only to a lowering of the transition temperature into the commensurate charge-density wave state (CDW) but also to the formation of a √(13) x √(13) superstructure, previously observed for the 1T polytype only. The origin, spectroscopic appearance, and influence of these superstructures on the electronic properties of 2H-TaSe2 are discussed.

  14. Multicomponent Synthesis of 3,6-Dihydro-2H-1,3-thiazine-2-thiones

    Frans J. J. de Kanter

    2012-02-01

    Full Text Available Non-fused 3,6-dihydro-2H-1,3-thiazine-2-thiones constitute a so far rather unexplored class of compounds, with the latest report dating back more than two decades. Thiazine-2-thiones contain an endocyclic dithiocarbamate group, which is often found in pesticides, in substrates for radical chemistry and in synthetic intermediates towards thioureas and amidines. We now report the multicomponent reaction (MCR of in situ-generated 1-azadienes with carbon disulfide. With this reaction, a one-step protocol towards the potentially interesting 3,6-dihydro-2H-1,3-thiazine-2-thiones was established and a small library was synthesized.

  15. Trojan Horse particle invariance for 2H(d,p)3H reaction: a detailed study

    Pizzone R.G.; Spitaleri C.; Bertulani C.A.; Mukhamedzhanov A.M.; Blokhintsev L.; La Cognata M.; Lamia L.; Rinollo A.; Spartá R.; Tumino A.

    2014-01-01

    In the last decades the Trojan Horse method has played a crucial role for the measurement of several charged particle induced reactions cross sections of astrophysical interest. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The Trojan Horse nucleus invariance for the binary d(d,p)t reaction was therefore tested using the quasi free 2H(6Li, pt)4He and 2H(3He,pt)H reaction...

  16. Protein kinase C-α mediates TNF release process in RBL-2H3 mast cells

    Abdel-Raheem, Ihab T; Hide, Izumi; Yanase, Yuhki; Shigemoto-Mogami, Yukari; SAKAI, Norio; Shirai, Yasuhito; Saito, Naoaki; Hamada, Farid M; El-Mahdy, Nagh A; Elsisy, Alaa El-Din E; Sokar, Samya S; Nakata, Yoshihiro

    2005-01-01

    To clarify the mechanism of mast cell TNF secretion, especially its release process after being produced, we utilized an antiallergic drug, azelastine (4-(p-chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4-yl)-1-(2H)- phthalazinone), which has been reported to inhibit TNF release without affecting its production in ionomycin-stimulated RBL-2H3 cells.Such inhibition was associated with the suppression of an ionomycin-induced increase in membrane-associated PKC activity rather than the suppressi...

  17. Study of the peak effect phenomenon in single crystals of 2H-NbSe2

    C V Tomy; D Pal; S S Banerjee; S Ramakrishnan; A K Grover; S Bhattacharya; M Higgins; G Balakrishnan; McK Paul

    2002-05-01

    The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order–disorder transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability effects and pinning.

  18. Analytical potential energy surface for O + C2H2 system

    Garashchuk, Sophya; Rassolov, Vitaly A.; Braams, Bastiaan J.

    2013-11-01

    Full-dimensional analytical potential energy surfaces (PESs) for the O(1P) + C2H2 and O(3P) + C2H2 reactions are presented. The PESs are constructed by fitting thousands of ab initio data points using permutationally invariant polynomials [5]. Electronic structure data are obtained within the restricted coupled cluster theory with single and double excitations with perturbative triple corrections and correlation consistent basis set of triple-ζ with diffuse functions. Motivated by experiments, formation of DOCC and cyclic DCCO at collision energies of 2.5-4 eV is examined using quasi-classical trajectory dynamics on the triplet surface.

  19. Infrared intensities and optical constants of crystalline C 2H 4 and C 2D 4

    Zhao, G.; Ospina, M. J.; Khanna, R. K.

    Infrared absorption spectra of several thin films of C 2H 4 and C 2D 4 at ˜55 K were investigated at ˜0.6 cm -1 resolution. The integrated band intensities of the infrared active fundamental modes were obtained by a linear fit of the integrated absorbances vs film thickness. An iterative Kramers—Kronig analysis of the absorption data was carried out to obtain the complex refractive indices of crystalline C 2H 4 and C 2D 4 in the regions of absorption bands.

  20. A Gas-Phase Investigation of Oxygen-Hydrogen Exchange Reaction of O(3P) + C2H5 → H(2S) + C2H4O

    The gas-phase radical-radical reaction O(3P) + C2H5 (ethyl) → H(2S) + CH3CHO (acetaldehyde) was investigated by applying a combination of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration and ab initio calculations. The two radical reactants O(3P) and C2H5 were respectively produced by photolysis of NO2 and supersonic flash pyrolysis of the synthesized precursor azoethane. Doppler profile analysis of the nascent H-atom products in the Lyman-α region revealed that the average translational energy of the products and the average fraction of the total available energy released as translational energy were 5.01 ± 0.72 kcal mol-1 and 6.1%, respectively. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title exchange reaction is a major channel and proceeds via an addition-elimination mechanism through the formation of a short-lived, dynamical addition complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed small kinetic energy release can be explained in terms of the loose transition state with a product-like geometry and a small reverse activation barrier along the reaction coordinate

  1. Synthesis and Crystal Structure of Ni3(admt)6(NCS)6·C2H5OH·2H2O

    2000-01-01

    Reaction of nickel (Ⅱ) perchlorate with 4-amino-3,5-dimethyl-1,2,4-triaxole(admt)and NG4NCS gave a trinuclear complex Ni3(admtrz)6 (NCS)6·C2H5OH·2H2O,C32H58N30Ni3O3S6.The compound crystallizes in the orthorhombic space group Pbca(#61) with a=13. 551(3) , b=25.146(6), c=16.553(4) A, V=5640(2)A 3, Z=4, Mr=1279.47, Dc=1. 507 g/cm3; μ(Mo-Kα)=12.70 cm-1 and F(000) = 2656. The final refinement with 2543 observed reflections is converged with R= 0. 058 and Rw= 0. 069. In the Ni3 (admt)6 (NCS)6 molecule, the central nickel atom is coordinated in a distorted octahedral environment by four triazole bridges and two thiocyanate bridges. The terminal nickel atoms are in addition coordinated by two thiocyanate and one admtrz ligand, and thus also have a distorted octahedral geometry.Ni-N distances are 2.040(7)-2. 222(7) A, Ni-Ni distances are 3. 411(1) A.

  2. Investigation of Compton profiles of NO and C2H2%NO与C2H2的康普顿轮廓研究

    马永朋; 赵小利; 刘亚伟; 徐龙泉; 康旭; 倪冬冬; 闫帅; 朱林繁; 杨科

    2015-01-01

    The Compton profiles of nitric oxide and acetylene molecules have been determined at an incident photon energy of 20 keV. Compton profile measurements are carried out with the beamline BL15U1 at the Shanghai Synchrotron Radiation Facility (SSRF). A dedicated gas cell is used, in which diffuse scattering is effectively suppressed. By considering that the statistical accuracy of 0.2%at pz ≈0 is achieved, the Compton profiles of NO and C2H2 determined in this paper can serve as the experimental benchmark data. Furthermore, the density functional theory (DFT) and HF calculation for different basis sets are used to calculate the Compton profiles of nitric oxide and acetylene. It is found that the DFT calculations with the diffuse basis sets are closer to the experimental results, indicating that the electronic density distribution of nitric oxide is more diffuse. For acetylene, the HF calculation is of better agreement with the experimental result. To better understand Compton profiles, we have compared them with distributions of electron density by theoretical calculation. There are clear correspondences between them: diffuse distribution is related to the localized profile and complex structure in electron density distribution, which also shows a subtle structure in profile. The present Compton profiles of nitric oxide and acetylene molecules achieved by synchrotron radiation are the most accurate up to now, as far as we know.%基于第三代同步辐射光源,在20 keV的入射X射线能量下测量了NO与C2H2分子的康普顿轮廓.考虑到本次实验结果在pz ≈0附近的统计精度达到了0.2%,本文报道的NO和C2H2的康普顿轮廓可以作为严格检验理论的实验基准.除此之外,还分别采用HF方法及密度泛函方法选用不同的基组计算了NO与C2 H2康普顿轮廓.通过对比实验结果与理论计算,发现对于NO分子,加入弥散函数基组理论计算结果与实验符合更好,说明NO分子基态的电

  3. 脉冲调制射频容性耦合SiH/C2H4/Ar放电的发射光谱诊断%Optical emission spectrometry diagnosis of pulse-modulated RF capacitive coupling discharge in SiH4/C2H4/Ar

    张娇; 张鹏云

    2011-01-01

    Characteristics of pulse-modulated capacitive coupling plasmas in SiH4/C2H4/Ar gas mixture were diagnosed by optical emission spectroscopy.The electron excitation temperature of plasmas was calculated with the five Ar emission spectral lines by Boltzmann slope method.Then, the dependence of the excitation temperature and relative emission intensity on the discharge power, duty cycle, modulation frequency and gas pressure were presented.%本文采用发射光谱法诊断了低气压下氩气(Ar)、硅烷(SiH4)及乙烯(C2H4)混合气体(SiH4/C2H4/Ar)脉冲调制射频放电等离子体特性,利用了Ar发射光谱中的五条谱线通过Boltzmann斜率法计算了电子激发温度,研究了占空比、调制频率、功率及气压等对电子激发温度和谱线相对强度的影响.

  4. Synthesis and properties of [(DMSO)2H] trans-[Ru(DMSO)2Cl4

    [(DMSO)2H]trans-[Ru(DMSO)2Cl4] is synthesized through interaction of ruthenium hydroxotrichloride with DMSO in weakly acid acetone or alcoholic solution. The compound is identified by methods of chemical analysis RPA, ESP, EPR and IRS. The complex behaviour in DMSO and acid solutions is studied

  5. Analytical Formulas of Molecular Ion Abundances and N2H+ Ring in Protoplanetary Disks

    Aikawa, Yuri; Nomura, Hideko; Qi, Chunhua

    2015-01-01

    We investigate the chemistry of ion molecules in protoplanetary disks, motivated by the detection of N$_2$H$^+$ ring around TW Hya. While the ring inner radius coincides with the CO snow line, it is not apparent why N$_2$H$^+$ is abundant outside the CO snow line in spite of the similar sublimation temperatures of CO and N$_2$. Using the full gas-grain network model, we reproduced the N$_2$H$^+$ ring in a disk model with millimeter grains. The chemical conversion of CO and N$_2$ to less volatile species (sink effect hereinafter) is found to affect the N$_2$H$^+$ distribution. Since the efficiency of the sink depends on various parameters such as activation barriers of grain surface reactions, which are not well constrained, we also constructed the no-sink model; the total (gas and ice) CO and N$_2$ abundances are set constant, and their gaseous abundances are given by the balance between adsorption and desorption. Abundances of molecular ions in the no-sink model are calculated by analytical formulas, which a...

  6. 4-[(2H-Tetrazol-2-yl)methyl]benzonitrile

    Zhi-Rong Qu; Zheng Xing

    2008-01-01

    The title compound, C9H7N5, was synthesized by reaction of 4-(bromomethyl)benzonitrile and 2H-tetrazole in the presence of KOH. The relative orientation of the planar tetrazole ring and the methylbenzonitrile moiety is (−)-anticlinal. The crystal packing is dominated by van der Waals interactions.

  7. Optimizing GC Injections when Analyzing δ2H of Vanillin for Traceability Studies

    Hansen, Anne-Mette Sølvbjerg; Fromberg, Arvid; Frandsen, Henrik Lauritz

    Column overloading is a problem when analyzing δ2H, due to the low natural abundance of deuterium and poor ionization efficiency of H2. This problem can be overcome by using split injections instead of splitless. In this study we have compared the influence upon the measured isotopic ratios when ...

  8. Structural transition study of NiCl2.2H2O by specific heat

    The specific heat of polycrystalline NiCl2.2H2O measured in an adiabatic calorimeter by the heat-pulse method between 80 and 281 K indicates a first-order phase transition at Tc = (220.0 ± 0.5) K. This confirms a crystallographic transformation first detected by X-ray and EPR methods. (author)

  9. NEUT development for T2K and relevance of updated 2p2h models

    Wilkinson, Callum

    2015-01-01

    The MiniBooNE large axial-mass anomaly has motivated the development of new theoretical Charged Current Quasi-Elastic (CCQE) cross-section models in recent years. These proceedings review the development of the neutrino simulation generator NEUT to incorporate these more sophisticated CCQE models, including multi-nucleon interaction (2p2h) effects. The fit results on the MINER$\

  10. A Search for ^2H, ^3H, and ^3He in Large Solar Flares

    Mewaldt, R. A.; Stone, E. C.

    1983-01-01

    The results of a new study of solar flare H and He isotopes imply that earlier observations have significantly overestimated the abundances of ^2H, ^3H, and ^3He in large solar flares. We find no evidence that solar flare nuclei have suffered any significant amount of fragmentation before escaping from the Sun.

  11. Photo-induced reactions in the ion-molecule complex Mg+-OCNC2H5

    Sun, Ju-Long; Liu, Haichuan; Han, Ke-Li; Yang, Shihe

    2003-06-01

    Ion-molecule complexes of magnesium cation with ethyl isocyanate were produced in a laser-ablation supersonic expansion nozzle source. Photo-induced reactions in the 1:1 complexes have been studied in the spectral range of 230-410 nm. Photodissociation mass spectrometry revealed the persistent product Mg+ from nonreactive quenching throughout the entire wavelength range. As for the reactive channels, the photoproducts, Mg+OCN and C2H5+, were produced only in the blue absorption band of the complex with low yields. The action spectrum of Mg+(OCNC2H5) consists of two pronounced peaks on the red and blue sides of the Mg+ 32P←32S atomic transition. The ground state geometry of Mg+-OCNC2H5 was fully optimized at B3LYP/6-31+G** level by using GAUSSIAN 98 package. The calculated absorption spectrum of the complex using the optimized structure of its ground state agrees well with the observed action spectrum. Photofragment branching fractions of the products are almost independent of the photolysis photon energy for the 3Px,y,z excitations. The very low branching ratio of reactive products to nonreactive fragment suggests that evaporation is the main relaxation pathway in the photo-induced reactions of Mg+(OCNC2H5).

  12. A combined crossed molecular beams and theoretical study of the reaction CN + C2H4

    Highlights: • The CN + C2H4 reaction was investigated in crossed beam experiments. • Electronic structure calculations of the potential energy surface were performed. • RRKM estimates qualitatively reproduce the experimental C2H3NC yield. - Abstract: The CN + C2H4 reaction has been investigated experimentally, in crossed molecular beam (CMB) experiments at the collision energy of 33.4 kJ/mol, and theoretically, by electronic structure calculations of the relevant potential energy surface and Rice–Ramsperger–Kassel–Marcus (RRKM) estimates of the product branching ratio. Differently from previous CMB experiments at lower collision energies, but similarly to a high energy study, we have some indication that a second reaction channel is open at this collision energy, the characteristics of which are consistent with the channel leading to CH2CHNC + H. The RRKM estimates using M06L electronic structure calculations qualitatively support the experimental observation of C2H3NC formation at this and at the higher collision energy of 42.7 kJ/mol of previous experiments

  13. Quaternion-valued admissible wavelets and orthogonal decomposition of L2(IG(2),(H))

    ZHAO Jiman; PENG Lizhong

    2007-01-01

    A series of admissible wavelets is fixed, which forms an ortho- normal basis for the Hilbert space of all the quaternion-valued admissible wavelets. It turns out that their corresponding admissible wavelet transforms give an orthogonal decomposition of L2 (IG(2), (H)).

  14. N2H+ depletion in the massive protostellar cluster AFGL 5142

    Busquet, Gemma; Zhang, Qizhou; Viti, Serena; Palau, Aina; Ho, Paul T P; Sanchez-Monge, Alvaro

    2010-01-01

    We aim at investigating with high angular resolution the NH3/N2H+ ratio toward the high-mass star-forming region AFGL 5142 in order to study whether this ratio behaves similarly to the low-mass case, for which the ratio decreases from starless cores to cores associated with YSOs. CARMA was used to observe the 3.2 mm continuum and N2H+(1-0) emission. We used NH3(1,1) and (2,2), HCO+(1-0) and H13CO+(1-0) data from the literature and we performed a time-dependent chemical modeling of the region. The 3.2 mm continuum emission reveals a dust condensation of ~23 Msun associated with the massive YSOs, deeply embedded in the strongest NH3 core (hereafter central core). The N2H+ emission reveals two main cores, the western and eastern core, located to the west and to the east of the mm condensation, and surrounded by a more extended and complex structure of ~0.5 pc. Toward the central core the N2H+ emission drops significantly, indicating a clear chemical differentiation in the region. We found low values of the NH3/N...

  15. Synthesizing mixed H2/H-infinity dynamic controller using evolutionary algorithms

    Pedersen, Gerulf; Langballe, A.S.; Wisniewski, Rafal

    2001-01-01

    This paper covers the design of an Evolutionary Algorithm (EA), which should be able to synthesize a mixed H2/H-infinity. It will be shown how a system can be expressed as Matrix Inequalities (MI) and these will then be used in the design of the EA. The main objective is to examine whether a mixed...

  16. Synthesizing multi-objective H2/H-infinity dynamic controller using evolutionary algorithms

    Pedersen, Gerulf; Langballe, A.S.; Wisniewski, Rafal

    This paper covers the design of an Evolutionary Algorithm (EA), which should be able to synthesize a mixed H2/H-infinity. It will be shown how a system can be expressed as Matrix Inequalities (MI) and these will then be used in the design of the EA. The main objective is to examine whether a mixed...

  17. Study of UO2F2 - H2O - HF compounds

    We study various compounds resulting from the interaction of UO2F2 with H2O and HF (gas), and various triple compounds UO2F2 - H2O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author)

  18. LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY

    Adu-Wusu, K.

    2012-05-10

    Glycolic acid (GA) is being studied as an alternate reductant in the Defense Waste Processing Facility (DWPF) feed preparation process. It will either be a total or partial replacement for the formic acid that is currently used. A literature review has been conducted on the impact of glycolate on two post-DWPF downstream systems - the 2H Evaporator system and the Effluent Treatment Facility (ETF). The DWPF recycle stream serves as a portion of the feed to the 2H Evaporator. Glycolate enters the evaporator system from the glycolate in the recycle stream. The overhead (i.e., condensed phase) from the 2H Evaporator serves as a portion of the feed to the ETF. The literature search revealed that virtually no impact is anticipated for the 2H Evaporator. Glycolate may help reduce scale formation in the evaporator due to its high complexing ability. The drawback of the solubilizing ability is the potential impact on the criticality analysis of the 2H Evaporator system. It is recommended that at least a theoretical evaluation to confirm the finding that no self-propagating violent reactions with nitrate/nitrites will occur should be performed. Similarly, identification of sources of ignition relevant to glycolate and/or update of the composite flammability analysis to reflect the effects from the glycolate additions for the 2H Evaporator system are in order. An evaluation of the 2H Evaporator criticality analysis is also needed. A determination of the amount or fraction of the glycolate in the evaporator overhead is critical to more accurately assess its impact on the ETF. Hence, use of predictive models like OLI Environmental Simulation Package Software (OLI/ESP) and/or testing are recommended for the determination of the glycolate concentration in the overhead. The impact on the ETF depends on the concentration of glycolate in the ETF feed. The impact is classified as minor for feed glycolate concentrations {le} 33 mg/L or 0.44 mM. The ETF unit operations that will have

  19. Resolving the sources of plasma glucose excursions following a glucose tolerance test in the rat with deuterated water and [U-13C]glucose

    Delgado, T.C.; Barosa, C.; Nunes, P.M.; Cerdán, S.; Geraldes, C.F.G.C.; Jones, J.G.

    2012-01-01

    Sources of plasma glucose excursions (PGE) following a glucose tolerance test enriched with [U-(13)C]glucose and deuterated water were directly resolved by (13)C and (2)H Nuclear Magnetic Resonance spectroscopy analysis of plasma glucose and water enrichments in rat. Plasma water (2)H-enrichment att

  20. Change of plasma visfatin level in the population with different glucose tolerances

    杨媚

    2006-01-01

    Objective To investigate the change of plasma visfatin level and the relationship of plasma visfatin level to body mass index (BMI) , waist hip ratio (WHR) , blood glucose, plasma insulin levels as well as other factors in the subjects with different glucose tolerances. Methods Fasting and glucose loading 2 h plasma visfatin levels were assayed by ELISA in patients with type 2 diabetes

  1. Microbial H2 cycling does not affect δ2H values of ground water

    Landmeyer, J.E.; Chapelle, F.H.; Bradley, P.M.

    2000-01-01

    Stable hydrogen-isotope values of ground water (δ2H) and dissolved hydrogen concentrations (H(2(aq)) were quantified in a petroleum-hydrocarbon contaminated aquifer to determine whether the production/consumption of H2 by subsurface microorganisms affects ground water &delta2H values. The range of &delta2H observed in monitoring wells sampled (-27.8 ‰c to -15.5 ‰c) was best explained, however, by seasonal differences in recharge temperature as indicated using ground water δ18O values, rather than isotopic exchange reactions involving the microbial cycling of H2 during anaerobic petroleum-hydrocarbon biodegradation. The absence of a measurable hydrogen-isotope exchange between microbially cycled H2 and ground water reflects the fact that the amount of H2 available from the anaerobic decomposition of petroleum hydrocarbons is small relative to the amount of hydrogen present in water, even though milligram per liter concentrations of readily biodegradable contaminants are present at the study site. Additionally, isotopic fractionation calculations indicate that in order for H2 cycling processes to affect δ2H values of ground water, relatively high concentrations of H2 (>0.080 M) would have to be maintained, considerably higher than the 0.2 to 26 nM present at this site and characteristic of anaerobic conditions in general. These observations suggest that the conventional approach of using δ2H and δ18O values to determine recharge history is appropriate even for those ground water systems characterized by anaerobic conditions and extensive microbial H2 cycling.

  2. Tailoring the hydrogen desorption thermodynamics of V{sub 2}H by alloying additives

    Kumar, Sanjay, E-mail: sanjay.barc@gmail.com [Fusion Reactor Materials Section, BARC, Mumbai (India); Tiwari, G.P. [R.A. Institute of Technology, Vidya Nagri, Nerul 400709, Navi Mumbai (India); Krishnamurthy, N. [Fusion Reactor Materials Section, BARC, Mumbai (India)

    2015-10-05

    Highlights: • Decomposition of VH{sub 2} is three step process. • Electronic structure and H solubility are correlated. • Addition of hydride forming metal enhance the thermal stability of V{sub 2}H. • Lattices strain energy could decrease thermal stability of V{sub 2}H. - Abstract: Vanadium could be a potential candidate for on board hydrogen storage application because of its high gravimetric hydrogen storage capacity (∼3.8 mass%) which is even better then the most widely explored AB{sub 5}, AB{sub 2} & AB intermetallic compounds. Hydrogen absorption of vanadium takes place at ambient temperature and pressure with fast kinetics. The vanadium hydride (VH{sub 2}) releases hydrogen in two steps: (1) VH{sub 2}(γ){sub (s)} ↔ ½ V{sub 2}H(β){sub (s)} and (2) V{sub 2}H(β){sub (s)} ↔ 2V{sub (s)} + ½ H{sub 2(g)}. First step is achievable at the ambient temperature and pressure conditions while, the second step requires high temperature (590 K). Thus only half of the total hydrogen storage capacity is available for use on subsequent absorption–desorption cycles at the ambient temperature. The usable hydrogen storage capacity of VH{sub 2} at ambient conditions could be enhanced by tailoring the thermodynamics and kinetics of second step of hydrogen desorption reaction. This could be possible by selecting suitable alloy additives. The present study deals with the selection criteria of alloy additives based on the electronic consideration to tailor the hydrogen desorption thermodynamics and kinetics of V{sub 2}H.

  3. Plasma theory

    A series of lectures on plasma theory with the main headings: introduction; charged particles moving in em fields; the liquid model; transport phenomena in the plasma; wave propagation in plasmas; plasma instabilities. 57 figs. (qui)

  4. Equilibrium coefficient of cocrystallization in the system ZnC2O4x2H2O-Mn(2)-H2O

    To determine the equilibrium volume coefficient of cocrystallization (D) of the Mn(2+) impurity, labelled by 54Mn radionuclide with sediment ZpC2O4x2H2O (Mn concentration in aqueous solution is 4x10-6 - 1.86x10-3 mol/l) three methods are used: 1) spontaneous sediment ripening; 2) sediment ripening alternating with wearing of a solid phase; 3) technique of express D determination for difficultly soluble substances in open systems. It is shown that the 1 and 2 methods lead to the same stationary state of the system for which D--0.100+-0.006, and D magnitude is not dependent on initial Mn concentration. The 3 method gives overstated magnitudes of D=O.16+-0.04

  5. The Dissociation Energies of CH4 and C2H2 Revisited

    Partridge, Harry; Bauschlicher, Charles W., Jr.; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The bond dissociation energies of CH4 and C2H2 and their fragments are investigated using basis set extrapolations and high levels of correlation. The computed bond dissociation energies (D(sub e)) are accurate to within 0.2 kcal/mol. The agreement with the experimental (D(sub 0)) values is excellent if we assume that the zero-point energy of C2H is 9.18 kcal/mol. The effect of core (1s) correlation on the bond dissociation energies of C-H bonds is shown to vary from 0.2 to 0.7 kcal/mol and that for C-C bonds varies from 0.4 to 2.2 kcal/mol.

  6. THE 2H(alpha, gamma6LI REACTION AT LUNA AND BIG BANG NUCLEOSYNTHETIS

    Carlo Gustavino

    2013-12-01

    Full Text Available The 2H(α, γ6Li reaction is the leading process for the production of 6Li in standard Big Bang Nucleosynthesis. Recent observations of lithium abundance in metal-poor halo stars suggest that there might be a 6Li plateau, similar to the well-known Spite plateau of 7Li. This calls for a re-investigation of the standard production channel for 6Li. As the 2H(α, γ6Li cross section drops steeply at low energy, it has never before been studied directly at Big Bang energies. For the first time the reaction has been studied directly at Big Bang energies at the LUNA accelerator. The preliminary data and their implications for Big Bang nucleosynthesis and the purported 6Li problem will be shown.

  7. Crystal structure of (6-bromo-2-oxo-2H-chromen-4-ylmethyl morpholine-4-carbodithioate

    K. Mahesh Kumar

    2015-07-01

    Full Text Available In the title compound, C15H14BrNO3S2, the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.034 (2 Å, and the morpholine ring adopts a chair conformation. The dihedral angle between best plane through the 2H-chromene ring system and the morpholine ring is 86.32 (9°. Intramolecular C—H...S hydrogen bonds are observed. In the crystal, inversion-related C—H...S and C—H...O interactions generate R22(10 and R22(8 rings patterns, respectively. In addition, the crystal packing features π–π interactions between fused benzene rings [centroid–centroid distance = 3.7558 (12 Å].

  8. Preparation of [2`,3`,5`,6`-{sup 2}H{sub 4}]pteroylglutamic acid

    Dueker, S.R.; Clifford, A.J. [Univ. of California, Davis (United States). Dept. of Nutrition; Jones, A.D. [Univ. of California, Davis (United States). Dept. of Food Science and Technology; Smith, G.M. [Univ. of California, Davis (United States). Facility for Advanced Instrumentation

    1995-10-01

    Folic acid plays a key role in nucleic acid biosynthesis, essential for normal cell proliferation and function. Localized folate deficiencies may be related to changes in cytology associated with cancer development; analogs of folic acid, such as methotrexate, are potent chemotherapeutic agents and are widely used either alone or in combination therapy for many types of cancer. In this report we describe the synthesis of a tetra-deuterated folic acid from perdeuterated toluene. The primary intermediate, N-(4-amino [2,3,5,6{sup 2}H{sub 4}]benzolyl)-L-glutamic acid diethyl ester was coupled to N(2`)-acetyl-6-formylpterin to create [2`,3`,5`,6`-{sup 2}H{sub 4}]folic acid. A similar scheme can be used for the preparation of [1`,2`,3`,4`,5`,6`-{sup 13}C{sub 6}] folic acid [{sup 13}C{sub 6}] ring labeled toluene. (author).

  9. Synthesis and Stereochemical Assignment of Crypto-Optically Active (2) H6 -Neopentane.

    Masarwa, Ahmad; Gerbig, Dennis; Oskar, Liron; Loewenstein, Aharon; Reisenauer, Hans Peter; Lesot, Philippe; Schreiner, Peter R; Marek, Ilan

    2015-10-26

    The determination of the absolute configuration of chiral molecules is at the heart of asymmetric synthesis. Here we probe the spectroscopic limits for chiral discrimination with NMR spectroscopy in chiral aligned media and with vibrational circular dichroism spectroscopy of the sixfold-deuterated chiral neopentane. The study of this compound presents formidable challenges since its stereogenicity is only due to small mass differences. For this purpose, we selectively prepared both enantiomers of (2) H6 -1 through a concise synthesis utilizing multifunctional intermediates. While NMR spectroscopy in chiral aligned media could be used to characterize the precursors to (2) H6 -1, the final assignment could only be accomplished with VCD spectroscopy, despite the fleetingly small dichroic properties of 1. Both enantiomers were assigned by matching the VCD spectra with those computed with density functional theory. PMID:26480341

  10. The 2H Electric Dipole Moment in a Separable Potential Approach

    Afnan I.R.

    2010-04-01

    Full Text Available Measurement of the electric dipole moment (EDM of 2H or of 3He may well come prior to the coveted measurement of the neutron EDM. Exact model calculations for the deuteron are feasible, and we explore here the model dependence of such deuteron EDM calculations. We investigate in a separable potential approach the relationship of the full model calculation to the plane wave approximation, correct an error in an early potential model result, and examine the tensor force aspects of the model results as well as the effect of the short range repulsion found in the realistic, contemporary potential model calculations of Liu and Timmermans. We conclude that, because one-pion exchange dominates the EDM calculation, separable potential model calculations should provide an adequate picture of the 2H EDM until better than 10% measurements are achieved.

  11. Temporal and spatial distributions of δ18O and δ2H in precipitation in Romania

    Nagavciuc, Viorica; Bădăluță, Carmen-Andreea; Perșoiu, Aurel

    2015-04-01

    Stable isotope ratios of meteoric water have an important role in climatic, paleoclimatic, hydrological and meteorological studies. While such data are available from most of Europe, so far, in Romania (East Central Europe), no systematic study of the stable isotopic composition of precipitation exists. In this context, the aim of this study is to analyze the isotopic composition of rainwater, its temporal and spatial distribution, the identification of the main factors influencing these variations and the creation of the first map of spatial distribution of stable isotopes in precipitation in Romania. Between March 2012 and March 2014 we have collected monthly samples from 22 stations in Romania, which were subsequently analyzed for their δ18O and δ2H at the Stable Isotopes Laboratory, Stefan cel Mare University, Suceava, Romania. Precipitation in W and NW Romania plot along the GMWL, while those in the East are slightly below it, on an evaporative trend. The LMWL for Romania is defined as δ2H=7,27*δ18O + 6,92. The W-E gradient in the distribution of δ18O and δ2H are less marked than the N-S ones, with local influences dominating in areas of strong evaporation (intramountain basins, rain-shadow areas etc). In SW, and especially in autumn and winter, Meditteranean cyclones carry moisture from the Eastern Mediterranean, the δ18O and δ2H values in precipitation in the area plotting between the GMWL and the Eastern Mediterranean Meteoric Water Line. The isotopic composition of rainwater in Romania correlates well with air temperature, and is influenced to a lesser extent by other factors such as the amount of precipitation, topography configuration, the effect of continentalism and season of the year.

  12. Generalised permutation branes on a product of cosets Gk1/HxGk2/H

    We study the modifications of the generalized permutation branes defined in hep-th/0509153, which are required to give rise to the non-factorizable branes on a product of cosets Gk1/HxGk2/H. We find that for k1k2 there exists big variety of branes, which reduce to the usual permutation branes, when k1=k2 and the permutation symmetry is restored

  13. Study of the tau- -> 3h- 2h+ nu-tau Decay

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J 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; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; 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; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, 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 A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; 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 M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; 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; Treadwell, E; 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; 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; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; 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, Erwin; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, 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; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; 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; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L M; 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; 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; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; 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; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; 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; Martínez-Vidal, F; 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; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; 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 J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; 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; Bóna, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2004-01-01

    A preliminary measurement of the branching fraction of the tau- -> 3h-2h+nu decay (h= pi, K$) with the BaBar detector is found to be {8.52 +/- 0.09 +/- 0.40} x 10E-4, where the first error is statistical and the second is systematic. The data show evidence that the rho resonance plays a strong role in the decay of the tau lepton to five charged hadrons.

  14. Characterization Results for the March 2016 H-Tank Farm 2H Evaporator Overhead Samples

    Nicholson, J. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-09

    This report contains the radioanalytical results of the 2H evaporator overhead sample received at SRNL on March 16, 2016. Specifically, concentrations of 137Cs, 90Sr, and 129I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). All of the radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits.

  15. Bis[2-(2H-benzotriazol-2-yl-4-methylphenolato]palladium(II

    Chen-Yen Tsai

    2009-06-01

    Full Text Available In the title complex, [Pd(C13H10N3O2], the PdII atom is tetracoordinated by two N atoms and two O atoms from two bidentate 2-(2H-benzotriazol-2-yl-4-methylphenolate ligands, forming a square-planar environment. The asymmetric unit contains one half molecule in which the Pd atom lies on a centre of symmetry.

  16. 1H and 2H NMR study in paramagnetic solutions of Eu3+ nitrate

    The dependence of the spin-lattice rate(1/T1) of 1H and 2H nuclei for the 2.1 T magnetic field of the concentration (from 0.1 to 2.75 mol) of Eu3+ paramagnetic ions in the range from 263 K to 373 K is presented . Also the NMRD profield for the frecuency range from 0.1 to 500 Mhz is showed

  17. 4-[(2H-Tetra­zol-2-yl)meth­yl]benzonitrile

    Xing, Zheng; Qu, Zhi-Rong

    2008-01-01

    The title compound, C9H7N5, was synthesized by reaction of 4-(bromomethyl)benzonitrile and 2H-tetrazole in the presence of KOH. The relative orientation of the planar tetra­zole ring and the methyl­benzonitrile moiety is (−)-anti­clinal. The crystal packing is dominated by van der Waals inter­actions.

  18. Investigation of the $^{8}$Li($^{2}$H,p)$^{9}$Li Reaction at REX-ISOLDE

    2002-01-01

    We propose to investigate the $^{8}$Li($^{2}$H,p )$^{9}$Li reaction at REX-ISOLDE. The main aim is to test a recently found discrepancy in extracted spectroscopic factors for this reaction. As a byproduct we will obtain improved data relevant for predictions of the $^{8}$Li(n,$\\gamma$)$^{9}$Li rate in inhomogeneous nucleosynthesis. For the full experiment including beam tuning and background measurements we ask for 13 shifts.

  19. Band structure analysis of (1 × 2)-H/Pd(110)-pr

    Shuttleworth, I. G.

    2013-09-01

    A novel method of band structure analysis based on the atomic orbital (AO) coefficients in LCAO-DFT has been applied to the (1 × 2)-H/Pd(110)-pr system. The analysis has revealed symmetry-dependent Pd 4d band splitting due to H ligand effects; ensemble effects due to the (1 × 2) Pd reconstruction are shown to be relatively minor.

  20. [2H26]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

    Christian A. Citron; Dickschat, Jeroen S.

    2013-01-01

    During growth on fully deuterated medium the volatile terpene [2H26]-1-epi-cubenol was released by the actinomycete Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotope effect of deuterium is known to slow down all metabolic processes in living organisms. Potential app...

  1. Cross sections for H(2p) formation in slow He{sup 2+}-H collisions

    Higgins, D.P.; Geddes, J.; McCullough, R.W. [The Queen`s Univ. of Belfast (United Kingdom)] [and others

    1994-12-31

    A crossed beam method, previously developed in this laboratory, has been used to study H(2p) formation in He{sup 2+}-H collision by observing the spontaneous emission of Lyman alpha radiation. Measurements at energies below 8 keV amu{sup {minus}1} usefully extend previous higher energy data into an energy range where theoretical predictions are markedly different and exhibit interesting structures which reflect the complexity of the excitation mechanism.

  2. NMR resonance splitting of urea in stretched hydrogels: proton exchange and (1)H/(2)H isotopologues.

    Kuchel, Philip W; Naumann, Christoph; Chapman, Bogdan E; Shishmarev, Dmitry; Håkansson, Pär; Bacskay, George; Hush, Noel S

    2014-10-01

    Urea at ∼12 M in concentrated gelatin gel, that was stretched, gave (1)H and (2)H NMR spectral splitting patterns that varied in a predictable way with changes in the relative proportions of (1)H2O and (2)H2O in the medium. This required consideration of the combinatorics of the two amide groups in urea that have a total of four protonation/deuteration sites giving rise to 16 different isotopologues, if all the atoms were separately identifiable. The rate constant that characterized the exchange of the protons with water was estimated by back-transformation analysis of 2D-EXSY spectra. There was no (1)H NMR spectral evidence that the chiral gelatin medium had caused in-equivalence in the protons bonded to each amide nitrogen atom. The spectral splitting patterns in (1)H and (2)H NMR spectra were accounted for by intra-molecular scalar and dipolar interactions, and quadrupolar interactions with the electric field gradients of the gelatin matrix, respectively. PMID:25241007

  3. Modelling of c-C2H4O formation on grain surfaces

    Occhiogrosso, A; Ward, M D; Price, S D

    2012-01-01

    Despite its potential reactivity due to ring strain, ethylene oxide (c-C2H4O) is a complex molecule that seems to be stable under the physical conditions of an interstellar dense core; indeed it has been detected towards several high-mass star forming regions with a column density of the order of 10e13cm-2 (Ikeda et al. 2001). To date, its observational abundances cannot be reproduced by chemical models and this may be due to the significant contribution played by its chemistry on grain surfaces. Recently, Ward and Price (2011) have performed experiments in order to investigate the surface formation of ethylene oxide starting with oxygen atoms and ethylene ice as reactants. We present a chemical model which includes the most recent experimental results from Ward and Price (2011) on the formation of c-C2H4O. We study the influence of the physical parameters of dense cores on the abundances of c-C2H4O. We verify that ethylene oxide can indeed be formed during the cold phase (when the ISM dense cores are formed)...

  4. Angular momentum of the N2H+ cores in the Orion A cloud

    Tatematsu, Ken'ichi; Ohashi, Satoshi; Sanhueza, Patricio; Nguyen Luong, Quang; Umemoto, Tomofumi; Mizuno, Norikazu

    2016-04-01

    We have analyzed the angular momentum of the molecular cloud cores in the Orion A giant molecular cloud observed in the N2H+ J = 1-0 line with the Nobeyama 45 m radio telescope. We have measured the velocity gradient using position-velocity diagrams passing through core centers, and made sinusoidal fits against the position angle. Twenty-seven out of 34 N2H+ cores allowed us to measure the velocity gradient without serious confusion. The derived velocity gradient ranges from 0.5 to 7.8 km s-1 pc-1. We marginally found that the specific angular momentum J/M (against the core radius R) of the Orion N2H+ cores tends to be systematically larger than that of molecular cloud cores in cold dark clouds obtained by Goodman et al., in the J/M-R relation. The ratio β of rotational to gravitational energy is derived to be β = 10-2.3±0.7, and is similar to that obtained for cold dark cloud cores in a consistent definition. The large-scale rotation of the ∫-shaped filament of the Orion A giant molecular cloud does not likely govern the core rotation at smaller scales.

  5. Regulated release of Ca2+ from respiring mitochondria by Ca2+/2H+ antiport.

    Fiskum, G; Lehninger, A L

    1979-07-25

    Simultaneous measurements of oxygen consumption and transmembrane transport of Ca2+, H+, and phosphate show that the efflux of Ca2+ from respiring tightly coupled rat liver mitochondria takes place by an electroneutral Ca2+/2H+ antiport process that is ruthenium red-insensitive and that is regulated by the oxidation-reduction state of the mitochondrial pyridine nucleotides. When mitochondrial pyridine nucleotides are kept in a reduced steady state, the efflux of Ca2+ is inhibited; when they are in an oxidized state, Ca2+ efflux is activated. These processes were demonstrated by allowing phosphate-depleted mitochondria respiring on succinate in the presence of rotenone to take up Ca2+ from the medium. Upon subsequent addition of ruthenium red to block Ca2+ transport via the electrophoretic influx pathway, and acetoacetate, to bring mitochondrial pyridine nucleotides into the oxidized state, Ca2+ efflux and H+ influx ensued. The observed H+ influx/Ca2+ efflux ratio was close to the value 2.0 predicted for the operation of an electrically neutral Ca2+/2H+ antiport process. PMID:36390

  6. SAS2H: The SCALE-4 analysis sequence for LWR fuel depletion

    The primary use of the SAS2H control module of SCALE (Standardized Computer Analyses for Licensing Evaluation) is for fuel depletion analyses of light-water-reactor (LWR) fuel. Spent fuel characteristics such as radiation sources, heat generation sources, and isotopic concentrations can be computed within SCALE using the SAS2 control module. At each time step, the SAS2 sequence performs a radiation transport analysis (via XSDRNPM-S) to obtain appropriate cross sections and spectral parameters for an ORIGEN-S point-depletion analysis. Each ORIGEN-S case produces the burnup-dependent fuel composition to be used in the next spectral calculation. A final ORIGEN-S case is used to perform the complete depletion/decay analysis using the burnup-dependent cross sections. A significantly enhanced version of the SAS2 control module, which is denoted as SAS2H, has been made available with the release of SCALE-4. The techniques used by SAS2H are presented in this paper along with a discussion of some recent validation/verification efforts

  7. Liquid water on Mars - An energy balance climate model for CO2/H2O atmospheres

    Hoffert, M. I.; Callegari, A. J.; Hsieh, C. T.; Ziegler, W.

    1981-01-01

    A simple climatic model is developed for a Mars atmosphere containing CO2 and sufficient liquid water to account for the observed hydrologic surface features by the existence of a CO2/H2O greenhouse effect. A latitude-resolved climate model originally devised for terrestrial climate studies is applied to Martian conditions, with the difference between absorbed solar flux and emitted long-wave flux to space per unit area attributed to the divergence of the meridional heat flux and the poleward heat flux assumed to equal the atmospheric eddy heat flux. The global mean energy balance is calculated as a function of atmospheric pressure to assess the CO2/H2O greenhouse liquid water hypothesis, and some latitude-resolved cases are examined in detail in order to clarify the role of atmospheric transport and temperature-albedo feedback. It is shown that the combined CO2/H2O greenhouse at plausible early surface pressures may account for climates hot enough to support a hydrological cycle and running water at present-day insolation and visible albedo levels.

  8. The application of 2H2O to measure skeletal muscle protein synthesis

    Fluckey James D

    2010-04-01

    Full Text Available Abstract Skeletal muscle protein synthesis has generally been determined by the precursor:product labeling approach using labeled amino acids (e.g., [13C]leucine or [13C]-, [15N]-, or [2H]phenylalanine as the tracers. Although reliable for determining rates of protein synthesis, this methodological approach requires experiments to be conducted in a controlled environment, and as a result, has limited our understanding of muscle protein renewal under free-living conditions over extended periods of time (i.e., integrative/cumulative assessments. An alternative tracer, 2H2O, has been successfully used to measure rates of muscle protein synthesis in mice, rats, fish and humans. Moreover, perturbations such as feeding and exercise have been included in these measurements without exclusion of common environmental and biological factors. In this review, we discuss the principle behind using 2H2O to measure muscle protein synthesis and highlight recent investigations that have examined the effects of feeding and exercise. The framework provided in this review should assist muscle biologists in designing experiments that advance our understanding of conditions in which anabolism is altered (e.g., exercise, feeding, growth, debilitating and metabolic pathologies.

  9. Modeling studies of the chemical vapor deposition of boron films from B 2H 6

    Lamborn, Daniel R.; Snyder, David W.; Xi, X. X.; Redwing, Joan M.

    2007-02-01

    The effect of growth conditions on the chemical vapor deposition of boron thin films from diborane (B 2H 6) was investigated using a combination of experimental studies and computational fluid dynamics-based reactor modeling. A multi-physics computational model was developed to simulate the thermal-fluid environment in the reactor. The proposed chemistry model incorporated into the simulations includes gas-phase decomposition and formation of B 2H 6 and surface adsorption and reaction of borane (BH 3). The model accurately predicts the experimentally measured temperature and partial pressure dependence of the boron growth rate using the sticking coefficient of BH 3 on the growth surface as the only adjustable parameter in the calculations. The results indicate that at lower growth temperatures (500 °C) the growth rate is limited by mass transfer of BH 3 to the substrate surface. The studies of boron thin film growth are relevant to the deposition of superconducting MgB 2 thin films, in which B 2H 6 is used as the boron precursor.

  10. Preparation and Molecular Structure of (SCZ)(TNPG)·2H2O

    CHEN Hong-Yan; ZHANG Tong-Lai; ZHANG Jian-Guo

    2005-01-01

    The (SCZ)(TNPG)·2H2O prepared by mixing semicarbazide (SCZ) and trinitrophloroglucinol (TNPG) was characterized by elemental analysis and IR measurement, and its crystal structure was determined by X-ray single-crystal diffraction analysis.The crystal belongs to triclinic,0.93966(19), c = 1.1925(2) nm, α = 67.48(3), β = 77.56(3), γ = 78.93(3)°, V = 0.6908(2) nm3, Z = 2,Dc = 1.789 g/cm3, Mr = 373.23, F(000) = 384, S = 0.999 andt(MoKα) = 0.172 mm-1.The final R and wR are 0.0394 and 0.1057 for 1724 observed reflections with I > 2σ(I).It is concluded that (SCZ)(TNPG) 2H2O is an ionic compound composed of a cation SCZ+, an anion TNPG- and two water molecules.The TNPG anion and SCZ+ cation are bonded together by electrostatic attraction and hydrogen bonds, and the compound structure is stable.The thermal decomposition of (SCZ)(TNPG) 2H2O was studied by using TG-DTG and DSC techniques with a heating rate of 10 ℃/min, showing the compound contains one endothermic process of dehydrating stage and two intensive exothermic decomposition stages.The enthalpy of exothermic decomposition reaction is 452.31 kJ/mol.

  11. Angular Momentum of the N2H+ Cores in the Orion A Cloud

    Tatematsu, Ken'ichi; Sanhueza, Patricio; Luong, Quang Nguyen; Umemoto, Tomofumi; Mizuno, Norikazu

    2016-01-01

    We have analyzed the angular momentum of the molecular cloud cores in the Orion A giant molecular cloud observed in the N2H+ J = 1-0 line with the Nobeyama 45 m radio telescope. We have measured the velocity gradient using position velocity diagrams passing through core centers, and made sinusoidal fitting against the position angle. 27 out of 34 N2H+ cores allowed us to measure the velocity gradient without serious confusion. The derived velocity gradient ranges from 0.5 to 7.8 km/s/pc. We marginally found that the specific angular momentum J/M (against the core radius R) of the Orion N2H+ cores tends to be systematically larger than that of molecular cloud cores in cold dark clouds obtained by Goodman et al., in the J/M-R relation. The ratio beta of rotational to gravitational energy is derived to be beta = 10^{-2.3+/-0.7}, and is similar to that obtained for cold dark cloud cores in a consistent definition. The large-scale rotation of the integral-shaped filament of the Orion A giant molecular cloud does n...

  12. Laboratory IR Studies and Astrophysical Implications of C2H2-Containing Binary Ices

    Knez, C.; Moore, M. H.; Ferrante, R. F.; Hudson, R. L.

    2012-04-01

    Studies of molecular hot cores and protostellar environments have shown that the observed abundance of gas-phase acetylene (C2H2) cannot be matched by chemical models without the inclusion of C2H2 molecules subliming from icy grain mantles. Searches for infrared (IR) spectral features of solid-phase acetylene are under way, but few laboratory reference spectra of C2H2 in icy mixtures, which are needed for spectral fits to observational data, have been published. Here, we report a systematic study of the IR spectra of condensed-phase pure acetylene and acetylene in ices dominated by carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water (H2O). We present new spectral data for these ices, including band positions and intrinsic band strengths. For each ice mixture and concentration, we also explore the dependence of acetylene's ν5-band position (743 cm-1, 13.46 μm) and FWHM on temperature. Our results show that the ν5 feature is much more cleanly resolved in ices dominated by non-polar and low-polarity molecules, specifically CO, CO2, and CH4, than in mixtures dominated by H2O-ice. We compare our laboratory ice spectra with observations of a quiescent region in Serpens.

  13. LABORATORY IR STUDIES AND ASTROPHYSICAL IMPLICATIONS OF C2H2-CONTAINING BINARY ICES

    Studies of molecular hot cores and protostellar environments have shown that the observed abundance of gas-phase acetylene (C2H2) cannot be matched by chemical models without the inclusion of C2H2 molecules subliming from icy grain mantles. Searches for infrared (IR) spectral features of solid-phase acetylene are under way, but few laboratory reference spectra of C2H2 in icy mixtures, which are needed for spectral fits to observational data, have been published. Here, we report a systematic study of the IR spectra of condensed-phase pure acetylene and acetylene in ices dominated by carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and water (H2O). We present new spectral data for these ices, including band positions and intrinsic band strengths. For each ice mixture and concentration, we also explore the dependence of acetylene's ν5-band position (743 cm–1, 13.46 μm) and FWHM on temperature. Our results show that the ν5 feature is much more cleanly resolved in ices dominated by non-polar and low-polarity molecules, specifically CO, CO2, and CH4, than in mixtures dominated by H2O-ice. We compare our laboratory ice spectra with observations of a quiescent region in Serpens.

  14. Peak effect studies in single crystals CeRu2 and 2H-NbS2

    A A Tulapurkar; A K Grover; S Ramakrishnan; A Niazi; A K Rastogi

    2002-05-01

    We have studied the peak effect (PE) phenomenon in single crystals of weakly pinned superconductors CeRu2 and 2H-NbS2. 2H-NbS2 is iso-structural and iso-electronic to 2H-NbSe2, whose similarity with CeRu2 as regards the PE representing the order-to-disorder transformation of the flux line lattice was claimed some time ago. We report on the step change in equilibrium magnetization across the peak effect in CeRu2. We also present the vortex phase diagram of 2H-NbS2 obtained from the magnetization data, and compare the PE phenomenon in 2H-NbS2 and 2H-NbSe2.

  15. Gas-phase CO2, C2H2, and HCN toward Orion-KL

    Boonman, A. M. S.; van Dishoeck, E. F.; Lahuis, F.; Doty, S. D.; Wright, C. M.; Rosenthal, D.

    2003-03-01

    The infrared spectra toward Orion-IRc2, Peak 1 and Peak 2 in the 13.5-15.5 mu m wavelength range are presented, obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory. The spectra show absorption and emission features of the vibration-rotation bands of gas-phase CO2, HCN, and C2H2, respectively. Toward the deeply embedded massive young stellar object IRc2 all three bands appear in absorption, while toward the shocked region Peak 2 CO2, HCN, and C2H2 are seen in emission. Toward Peak 1 only CO2 has been detected in emission. Analysis of these bands shows that the absorption features toward IRc2 are characterized by excitation temperatures of ~ 175-275 K, which can be explained by an origin in the shocked plateau gas. HCN and C2H2 are only seen in absorption in the direction of IRc2, whereas the CO2 absorption is probably more widespread. The CO2 emission toward Peak 1 and 2 is best explained with excitation by infrared radiation from dust mixed with the gas in the warm component of the shock. The similarity of the CO2 emission and absorption line shapes toward IRc2, Peak 1 and Peak 2 suggests that the CO2 is located in the warm component of the shock (T ~ 200 K) toward all three positions. The CO2 abundances of ~ 10-8 for Peak 1 and 2, and of a few times 10-7 toward IRc2 can be explained by grain mantle evaporation and/or reformation in the gas-phase after destruction by the shock. The HCN and C2H2 emission detected toward Peak 2 is narrower (T ~ 50-150 K) and originates either in the warm component of the shock or in the extended ridge. In the case of an origin in the warm component of the shock, the low HCN and C2H2 abundances of ~ 10-9 suggest that they are destroyed by the shock or have only been in the warm gas for a short time (t Germany, The Netherlands and the UK) and with the participation of ISAS and NASA.

  16. Anti-sense RNA Inhibits the Expression of Synaptotagmin Ⅱ in RBL-2H3 and Enhances the Exocytosis of Lysosomes in RBL-2H3

    2005-01-01

    The expression of synaptotagmin Ⅱ (Syt2) in RBL-2H3 (RBL) and its role during exocytosis of RBL was investigated. The expression of Syt2 in RBL was detected by western blot and Syt2 gene was amplified by PCR. The anti-sense full length Syt2 cDNA expression vector was constructed with pEGFP-N1 and transfected into RBL by electroporation, and stable transfectants were selected by using G418. To analyze the role of Syt2 during exocytosis of RBL, the release of cathepsin D was assayed by immunoblotting. The results showed that Syt2 was expressed in RBL.The anti-sense expression vector pEGFP-N1-Syt2-AS was constructed and the sequence of insertion was completely consistent with rat Syt2 (accession number in GeneBank: NM012665). The stable transfectants (RBL-Syt2-AS) were obtained. Western blot showed that RBL-Syt2-AS expressed a lower level of Syt2 (8 % and 10 % of control cells), indicating that the expression of Syt2 in RBLSyt2-AS was markedly down-regulated by anti-RNA. Compared with control, the release of cathepsin D by RBL-Syt2-AS was increased. It was concluded that Syt2 expressed in RBL and could inhibit exocytosis of lysosomes in RBL.

  17. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    NICOLAY K; Smaal, E B; de Kruijff, B.

    1986-01-01

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal systems, indicative of acyl chain disordering.

  18. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal system, indicative of acyl chain disordering. (Auth.)

  19. Synthesis of 4-Triazolylamino- and 4-Benzothiazolylamino-3-nitro-2H-[1]-Benzopyran-2-ones and their Antimicrobial Activity

    Ramiz Hoti; Aferdita Nura-Lama; Gjyle Mulliqi-Osmani; Naser Troni; Fatbardh Gashi; Hamit Ismaili; Veprim Thaci

    2014-01-01

    Novel substituted benzopyran-2-one derivatives were synthesized by catalytic condensation reactions under reflux conditions. 4-(1,2,4-Triazolyl-3-amino)-3-nitro-2H-[1]-benzopyran-2-ones 4(a-b) were synthesized by condensation of 4-chloro-3-nitro-2H-[1]-benzopyran-2-one (2) and corresponding 3-aminotriazoles 3(a-b). 4-(4’-methoxy-2-benzothiazolylamino)-3-nitro-2H-[1]-benzopyran-2-one (4c), 4-(6’-nitro-2-benzothiazolylamino)-3-nitro-2H-[1]-benzopyiran-2-one (4d) and 4-(6’-fluoro-2-benzothiazoly...

  20. The hnRNP 2H9 gene, which is involved in the splicing reaction, is a multiply spliced gene

    Honoré, B

    2000-01-01

    The hnRNP 2H9 gene products are involved in the splicing process and participate in early heat shock-induced splicing arrest. By combining low/high stringency hybridisation, database search, Northern and Western blotting it is shown that the gene is alternatively spliced into at least six...... transcripts: hnRNPs 2H9, 2H9A, 2H9B, 2H9C, 2H9D and 2H9E predicting proteins containing 346, 331, 297, 215, 145 and 139 amino acids, respectively. The hnRNP 2H9A cDNA sequence was used to obtain a genomic BAC clone and the structure of the hnRNP 2H9 gene was revealed by sequencing two subclones together...... indicates that the alternatively spliced transcripts give rise to different sets and levels of proteins expressed among various human cells and tissues. Due to their great structural variations the different proteins may thus possess different functions in the splicing reaction. Udgivelsesdato: 2000-Jun-21...

  1. Plasma spot welding of ferritic stainless steels

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  2. Validation of SCALE (SAS2H) Isotopic Predictions for BWR Spent Fuel

    Hermann, O.W.

    1998-01-01

    Thirty spent fuel samples obtained from boiling-water-reactor (BWR) fuel pins have been modeled at Oak Ridge National Laboratory using the SAS2H sequence of the SCALE code system. The SAS2H sequence uses transport methods combined with the depletion and decay capabilities of the ORIGEN-S code to estimate the isotopic composition of fuel as a function of its burnup history. Results of these calculations are compared with chemical assay measurements of spent fuel inventories for each sample. Results show reasonable agreement between measured and predicted isotopic concentrations for important actinides; however, little data are available for most fission products considered to be important for spent fuel concerns (e.g., burnup credit, shielding, source-term calculations, etc.). This work is a follow-up to earlier works that studied the ability to predict spent fuel compositions in pressurized-water-reactor (PWR) fuel pins. Biases and uncertainties associated with BWR isotopic predictions are found to be larger than those of PWR calculations. Such behavior is expected, as the operation of a BWR is significantly more complex than that of a PWR plant, and in general the design of a BWR has a more heterogeneous configuration than that of a PWR. Nevertheless, this work shows that the simple models employed using SAS2H to represent such complexities result in agreement to within 5% (and often less than 1%) or less for most nuclides important for spent fuel applications. On the other hand, however, the set of fuel samples analyzed represent a small subset of the BWR fuel population, and results reported herein may not be representative of the full population of BWR spent fuel.

  3. Quinolone-1-(2H)-ones as hedgehog signalling pathway inhibitors.

    Trinh, Trieu N; McLaughlin, Eileen A; Abdel-Hamid, Mohammed K; Gordon, Christopher P; Bernstein, Ilana R; Pye, Victoria; Cossar, Peter; Sakoff, Jennette A; McCluskey, Adam

    2016-07-14

    A series of quinolone-2-(1H)-ones derived from the Ugi-Knoevenagel three- and four-component reaction were prepared exhibiting low micromolar cytotoxicity against a panel of eight human cancer cell lines known to possess the Hedgehog Signalling Pathway (HSP) components, as well as the seminoma TCAM-2 cell line. A focused SAR study was conducted and revealed core characteristics of the quinolone-2-(1H)-ones required for cytotoxicity. These requirements included a C3-tethered indole moiety, an indole C5-methyl moiety, an aliphatic tail or an ester, as well as an additional aromatic moiety. Further investigation in the SAG-activated Shh-LIGHT2 cell line with the most active analogues: 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(1-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (5), 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (23) and ethyl (2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)acetyl)glycinate (24) demonstrated a down regulation of the HSP via a reduction in Gli expression, and in the mRNA levels of Ptch1 and Gli2. Analogues 5, 23 and 24 returned in cell inhibition values of 11.6, 2.9 and 3.1 μM, respectively, making this new HSP-inhibitor pharmacophore amongst the most potent non-Smo targeted inhibitors thus far reported. PMID:27272335

  4. Volume-discharge formed in SF6 and C2H6 mixtures without preionization

    Zhang, Ge; Ke, Changjun; Zhang, Shujuan

    2014-11-01

    A new approach to obtain glow discharge in working mixtures of non-chain HF laser has been brought forward. The most advantage of the approach is without pre-ionization, so the contamination of pre-ionization will not happen and the laser equipment is compact and simple. It is found, if the cathode surface is equally rough, we can obtain uniform volume-discharge in SF6 mixtures without any pre-ionization, and dispense with uniform electric field electrode profile. The form of Self-Sustained Volume Discharge (SSVD) is a Self-Initiated Volume Discharge (SIVD). We show here the possibility of obtaining SIVD with a uniform energy deposition in a system of electrodes with non-uniform electric field. Experiments show that, with rough cathode and even anode, a volume discharge is forming in non-uniform electric-field without pre-ionization in SF6 and C2H6 mixtures. At the beginning of the discharge, many diffuse channels attached to bright circular cathode spots, then, diverge towards the anode, with the channels overlapping, form a spatially uniform glow discharge. SIVD has been performed at a total mixture pressure up to 8kPa and energy deposition up to 200J/l. We also report measurements of the V-I characteristics of SIVD with SF6 and C2H6 mixtures at pressure up to about 8kPa. The experimental results indicate that SSVD in SF6 and C2H6 mixtures develops in the form of SIVD is promising for creation of high energy and pulse-periodic HF laser.

  5. Spectroscopic Line Parameters in the Infrared Bands of CH3CN and C2H6

    Devi, V. Malathy

    2010-10-01

    In this paper, measurements of critical spectroscopic line parameters such as positions, absolute intensities and pressure broadened (self- and N2) half-width coefficients for transitions in the ν4 band of CH3CN (acetonitile, ethanenitrile, methyl cyanide) and the ν9 band of C2H6 (ethane) are presented. CH3CN has been measured by remote sensing in the earth's atmosphere, in comets and in interstellar molecular clouds. It is also a constituent in the atmospheres of Titan, Saturn's largest moon. Likewise, C2H6 is also an important constituent in the atmosphere of earth, the giant planets and comets. The 12- μm(˜720-850 cm-1) emission features of this molecule have been observed in spectra from outer solar system bodies of Jupiter, Saturn, Neptune and Titan. Because of their importance in remote sensing measurements, we recently recorded and analyzed a large number of laboratory infrared absorption spectra of pure and N2-broadened spectra of both these molecular bands. Spectra used in these analyses were recorded using either the Bruker IFS 125HR or the Bruker IFS 120HR FTS located at the Pacific Northwest National Laboratory (PNNL), in Richland Washington. To retrieve the various spectral line parameters, a multispectrum nonlinear least squares fitting algorithm was employed and all spectra belonging to each band were fitted simultaneously. Using this fitting technique, the same spectral regions from multiple spectra were fit all at once to maximize the accuracy of the retrieved parameters. The results obtained from present analyses are briefly discussed. In the case of C2H6 both room- and low temperature (˜210-296 K) spectra were recorded, but results from analyzing only room-temperature spectra will be discussed in this work.

  6. Thermal neutron capture cross sections for 16,171,18O and 2H

    Firestone, R. B.; Revay, Zs.

    2016-04-01

    Thermal neutron capture γ -ray spectra for 16,17,18O and 2H have been measured with guided cold neutron beams from the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) reactor and the Budapest Research Reactor (BRR) on natural and O,1817 enriched D2O targets. Complete neutron capture γ -ray decay schemes for the 16,17,18O(n ,γ ) reactions were measured. Absolute transition probabilities were determined for each reaction by a least-squares fit of the γ -ray intensities to the decay schemes after accounting for the contribution from internal conversion. The transition probability for the 870.76-keV γ ray from 16O(n ,γ ) was measured as Pγ(871 )=96.6 ±0.5 % and the thermal neutron cross section for this γ ray was determined as 0.164 ±0.003 mb by internal standardization with multiple targets containing oxygen and stoichiometric quantities of hydrogen, nitrogen, and carbon whose γ -ray cross sections were previously standardized. The γ -ray cross sections for the O,1817(n ,γ ) and 2H(n ,γ ) reactions were then determined relative to the 870.76-keV γ -ray cross section after accounting for the isotopic abundances in the targets. We determined the following total radiative thermal neutron cross sections for each isotope from the γ -ray cross sections and transition probabilities; σ0(16O )=0.170 ±0.003 mb; σ0(17O )=0.67 ±0.07 mb; σ0(18O )=0.141 ±0.006 mb; and σ0(2H )=0.489 ±0.006 mb.

  7. Synthesis and properties of [(DMSO)2H][Ru(DMSO)2Br4

    The ruthenium (3) [(DMSO)2H][Ru(DMSO)2Br4] complex, structure of which is defined on the basis of the chemical analysis, IRS and ESP data, is synthesized by interaction of ruthenium tribromide with DMSO. The compound is labile in the solutions, in the DMSO solutions it transforms into the ruthenium (2) dimethylsulfoxide complexes, in the HBr solutions occurs fast deoxygeneration of coordinated DMSO and formation of the ruthenium(3) dimethylsulfide complexes, which thereafter are transformed into [RuBr6]3- ion. The ruthenium(3) dimethylsulfide is formed by interaction of ruthenium with DMSO and in thepresence of HBr at the temperature of 130 deg C

  8. CO2-H2O和CO2-H2O-NaCl体系的相平衡研究进展%Progress in the Study on the Phase Equilibria of the CO2-H2O and CO2-H2O-NaCl Systems

    吉远辉; 吉晓燕; 冯新; 刘畅; 吕玲红; 陆小华

    2007-01-01

    To study the feasibility of CO2 geological sequestration, it is needed to understand the complicated multiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological conditions (273.15 473.15K, 0-60MPa), which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose, studies on the relevant phase equilibria and densities are reviewed and analyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable predictions in a wide temperature and pressure range.Besides, three different models (the electrolyte non random twoliquid (ELECNRTL), the electrolyte NRTL combining with Helgeson model (ENRTL-HG), Pitzer activity coefficient model combining with Helgeson model (PITZ-HG) are used to calculate the vapor-liquid phase equilibrium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system, the calculation results agree with the experimental data very well at low and medium pressure (0-20MPa), but there are great discrepancies above 20MPa.For the water content at 473.15K, the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system, the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCI concentration of 0.52mol·L-1.Bur for the NaCl concentration of 3.997mol·L-1,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accurate thermodynamic calculations are needed in high temperature and pressure ranges (above 398.15K and 31.5MPa).

  9. Measurement of Magnetization Curve and Magnetic Relaxation for 2H-NbSe2 Crystals

    Zhang Ning; Liu Hai-lin; Yu Zhu-xing; Xiong Rui; Shi Jing

    2004-01-01

    The characteristics of electronic transport properties: behaviors of magnetization curve and magnetic relaxation of a typical normal superconductor 2H-NbSe2 are investigated. The results show that TCand ΔTC of the samples are 7.2,0.18 K, indicating that superconducting energy gap at zero temperature is 1.1 meV. No fish tail shape is found in the magnetization curves at several temperatures. The relationship between remnant magnetic moment and time reveals that the magnetic flux creep of the sample agrees with the Kim-Anderson thermal activation model with the relaxation rate S=0.000 36 at T=6 K.

  10. Smoothed orientational order profile of lipid bilayers by 2H-nuclear magnetic resonance

    A new method has been developed to determine the complete orientational order profile of lipid bilayers using 2H-NMR. The profile is obtained from a single powder spectrum of a lipid which has a saturated chain fully deuteriated. The smoothed order profile is determined directly from the normalized dePaked spectrum assuming a monotonic decrease of the order along the acyl chain. The oscillatory variations of the order at the beginning of the chain are not described by this method. However the smoothed order profile reveals in a straightforward way the crucial features of the anisotropic order of the bilayer

  11. Relativistic model of 2p-2h meson exchange currents in (anti)neutrino scattering

    Simo, I Ruiz; Barbaro, M B; De Pace, A; Caballero, J A; Donnelly, T W

    2016-01-01

    We develop a model of relativistic, charged meson-exchange currents (MEC) for neutrino-nucleus interactions. The two-body current is the sum of seagull, pion-in-flight, pion-pole and $\\Delta$-pole operators. These operators are obtained from the weak pion-production amplitudes for the nucleon derived in the non-linear $\\sigma$-model together with weak excitation of the $\\Delta(1232)$ resonance and its subsequent decay into $N\\pi$. With these currents we compute the five 2p-2h response functions contributing to $(\

  12. 3-(3,4-Dihydroxyphenyl-8-hydroxy-2H-chromen-2-one

    Ivan Svinyarov

    2015-10-01

    Full Text Available We report a novel protocol for the synthesis of 3-(3,4-dihydroxyphenyl-8-hydroxy-2H-chromen-2-one via demethylation/delactonization/elimination/lactonization/ decarboxylation domino reaction sequence of diastereomeric mixture of cis- and trans-3-(2,3-dimethoxyphenyl-6,7-dimethoxy-1-oxoisochroman-4-carboxylic acids in boiling HBr/AcOH. The structure of the target compound was established for the first time by means of spectral methods such as 1H-, 13C-, DEPT-135-NMR, IR and HRMS.

  13. High purity H-2/H2O/Ni/SZ electrodes at 500 degrees C

    Høgh, Jens Valdemar Thorvald; Hansen, Karin Vels; Norrman, Kion; Chorkendorff, Ib; Jacobsen, Torben; Mogensen, Mogens

    2013-01-01

    stabilized zirconia (SZ) with 10,13 and 18 mol% yttria and one with 6 mol% scandia plus 4 mol% yttria were studied at open circuit voltage at 400-500 degrees C in mixtures of H-2/H2O over 46 days. The polarization resistances (R-p) for all samples increased significantly during the first 10-20 days at 500......The performance of SOFC (solid oxide fuel cell) anodes is influenced negatively by impurities. In the present study segregation of impurities is minimized by using high purity materials at relatively low temperatures to prevent fast segregation. Ni point electrodes on polished single crystals of...

  14. Transcriptional Silencing in the Imprinted Igf2-H19 Loci: The Mystique of Epigenetics

    Ginjala, Vasudeva

    2002-01-01

    Genomic imprinting marks a subset of autosomal loci expressed in parent of origin-dependent monoallelic expression in a non-Mendelian fashion. To restore totipotency and to reset the imprint according to the sex of the individual, the mark must be erased during germline development. The imprinted Igf2-H19 loci located distally on chromosome 7 in mouse and 11p15.5 in human, share common regulatory elements that regulate differential expression. Where the H19 is silenced when paternally inherit...

  15. Characterization Results for the 2014 HTF 3H & 2H Evaporator Overhead Samples

    Washington, A. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-05-11

    This report tabulates the radiochemical analysis of the 3H and 2H evaporator overhead samples for 137Cs, 90Sr, and 129I to meet the requirements in the Effluent Treatment Project (ETP) Waste Acceptance Criteria (WAC) (rev. 6). This report identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. All data was found to be within the ETP WAC (rev. 6) specification for the Waste Water Collection Tanks (WWCT).

  16. High purity H-2/H2O/Ni/SZ electrodes at 500 degrees C

    Høgh, Jens Valdemar Thorvald; Hansen, Karin Vels; Norrman, Kion;

    2013-01-01

    The performance of SOFC (solid oxide fuel cell) anodes is influenced negatively by impurities. In the present study segregation of impurities is minimized by using high purity materials at relatively low temperatures to prevent fast segregation. Ni point electrodes on polished single crystals...... of stabilized zirconia (SZ) with 10,13 and 18 mol% yttria and one with 6 mol% scandia plus 4 mol% yttria were studied at open circuit voltage at 400-500 degrees C in mixtures of H-2/H2O over 46 days. The polarization resistances (R-p) for all samples increased significantly during the first 10-20 days at 500...

  17. First-principles calculations of the magnetism of Fe$_2$O$_2$H$_2$

    Stolbov, Sergey; Klemm, Richard A.; Rahman, Talat S.

    2005-01-01

    By expanding the wave function in plane waves, we use the pseudopotential method of density functional theory within the generalized gradient approximation to calculate the effective magnetic coupling energies of the S=5/2 spins in the Fe2 dimer, approximated as Fe$_2$O$_2$H$_2$. Setting the Fe-O bond length at the value corresponding to the minimum total energy, we find the difference in antiferromagnetic and ferromagnetic exchange energies as a function of the Fe-O-Fe bond angle $\\theta$. T...

  18. Nonfactorized Calculation of the Process 3He(e,e'p)2H at Medium Energies

    The exclusive process 3He(e,e'p)2H has been analyzed by a nonfactorized and parameter-free approach based upon realistic few-body wave functions corresponding to the AV18 interaction and treating the rescattering of the struck nucleon within a generalized eikonal approximation. The results of our calculations, compared with recent JLab experimental data, show that the left-right asymmetry exhibits a clear dependence upon the final state interaction demonstrating the breaking down of the factorization approximation at 'negative' and large (> or approx. 300 MeV/c) values of the missing momentum

  19. Dissolution of plutonium metal in HNO3-N2H4-KF

    Plutonium metal dissolves in HNO3-N2H4.HNO3-KF solution to yield a Pu3+ solution without an accompanying precipitation of plutonium oxide solids. The reaction evolves less than 0.2 mole of gas per mole of plutonium dissolved; the gas contains only 3% H2. About 10-3 moles of HN3 are produced per mole of plutonium dissolved. Optimum conditions for dissolving both alpha-phase and delta-phase plutonium metal were developed. Possible applications are to the recovery of plutonium metal or the processing of irradiated plutonium metal and alloys

  20. Crystal structure of 2-oxo-N′-phenyl-2H-chromene-3-carbohydrazide

    Joel T. Mague

    2015-12-01

    Full Text Available In the title compound, C16H12N2O3, the 2H-chromene moiety is essentially planar, with an r.m.s. deviation of the nine constituent atoms from the mean plane of 0.0093 Å, and makes a dihedral angle of 76.84 (3° with the pendant phenyl ring. An intramolecular N—H...O hydrogen bond helps to determine the conformation of the side chain. In the crystal, N—H...O and N—H...N hydrogen bonds link the molecules, forming [100] chains.

  1. Photon polarization in the 4He(γ,rvec d)2H reaction

    We derive double polarization observables for the photodisintegration of 4He with an incident polarized photon beam. In particular we study the effect of the ground state α-particle D wave on these observables in a simple nuclear model. We find that in general the double polarization observables offer no clear advantage to the corresponding variables studied in the single polarization 4He(γ,rvec d)2H reaction. However, the photon asymmetry Σ appears as a promising observable for the study of ground state effects

  2. Methyl N-{4-[(4-methoxyphenoxymethyl]-2-oxo-2H-chromen-7-yl}carbamate

    K. Mahesh Kumar

    2012-06-01

    Full Text Available In the title compound, C19H17NO6, the dihedral angle between the 2H-chromene ring system and benzene ring is 5.34 (6°. A short intramolecular C—H...O contact occurs. In the crystal, molecules are linked by N—H...O hydrogen bonds, generating C(8 chains propagating in [010]. The chains are linked by C—H...O interactions and the packing also exhibits π–π stacking interactions between benzene and pyran rings, with a centroid–centroid distance of 3.676 (9 Å.

  3. [2H26]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

    Christian A. Citron

    2013-12-01

    Full Text Available During growth on fully deuterated medium the volatile terpene [2H26]-1-epi-cubenol was released by the actinomycete Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotope effect of deuterium is known to slow down all metabolic processes in living organisms. Potential applications of completely labelled compounds from natural sources in structure elucidation, biosynthetic or pharmacokinetic investigations are discussed.

  4. Thermodynamic study of NaCl-CdCl2-H2O system at 25 deg

    The solubility is studied and water activity is measured in the whole region concentrations of ternary solutions of the NaCl-CdCl2-H2O system at 25 deg by isothermal and isopiestic methods respectively. The solubility isotherm has two branches proper to crystallization of the 2xNaClxCdCl2x3H2O and 3xNaClx4CdCl2x14H2O complexes. Changes of isobar potential at formation of the above compounds from the system components are calculated, based on the data on phase equilibriums

  5. Plasma properties

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  6. Underestimation of glucose turnover measured with [6-3H]- and [6,6-2H]- but not [6-14C]glucose during hyperinsulinemia in humans

    Recent studies indicate that hydrogen-labeled glucose tracers underestimate glucose turnover in humans under conditions of high flux. The cause of this underestimation is unknown. To determine whether the error is time-, pool-, model-, or insulin-dependent, glucose turnover was measured simultaneously with [6-3H]-, [6,6-2H2]-, and [6-14C]glucose during a 7-h infusion of either insulin (1 mU.kg-1.min-1) or saline. During the insulin infusion, steady-state glucose turnover measured with both [6-3H]glucose (8.0 +/- 0.5 mg.kg-1.min-1) and [6,6-2H2]glucose (7.6 +/- 0.5 mg.kg-1.min-1) was lower (P less than .01) than either the glucose infusion rate required to maintain euglycemia (9.8 +/- 0.7 mg.kg-1.min-1) or glucose turnover determined with [6-14C]glucose and corrected for Cori cycle activity (9.8 +/- 0.7 mg.kg-1.min-1). Consequently negative glucose production rates (P less than .01) were obtained with either [6-3H]- or [6,6-2H2]- but not [6-14C]glucose. The difference between turnover estimated with [6-3H]glucose and actual glucose disposal (or 14C glucose flux) did not decrease with time and was not dependent on duration of isotope infusion. During saline infusion, estimates of glucose turnover were similar regardless of the glucose tracer used. High-performance liquid chromatography of the radioactive glucose tracer and plasma revealed the presence of a tritiated nonglucose contaminant. Although the contaminant represented only 1.5% of the radioactivity in the [6-3H]glucose infusate, its clearance was 10-fold less (P less than .001) than that of [6-3H]glucose. This resulted in accumulation in plasma, with the contaminant accounting for 16.6 +/- 2.09 and 10.8 +/- 0.9% of what customarily is assumed to be plasma glucose radioactivity during the insulin or saline infusion, respectively (P less than .01)

  7. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  8. EVIDENCE OF DIFFERENTIAL PH REGULATION OF THE ARABIDOPSIS VACUOLAR CA2+/H+ ANTIPORTERS CAX1 AND CAX2

    The Arabidopsis Ca(2+)/H(+) antiporters cation exchanger (CAX) 1 and 2 utilise an electrochemical gradient to transport Ca(2+) into the vacuole to help mediate Ca(2+) homeostasis. Previous whole plant studies indicate that activity of Ca(2+)/H(+) antiporters is regulated by pH. However, the pH regul...

  9. 2H-SiC Dendritic Nanocrystals In Situ Formation from Amorphous Silicon Carbide under Electron Beam Irradiation

    2006-01-01

    Under electron beam irradiation, the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed. The homogenous transition mainly occurs at the thin edge and on the surface of specimen where the energy obtained from electron beam irradiation is high enough to cause the amorphous crystallizing into 2H-SiC.

  10. Rapid solid-state NMR of deuterated proteins by interleaved cross-polarization from 1H and 2H nuclei

    Bjerring, Morten; Paaske, Berit; Oschkinat, Hartmut; Akbey, Ümit; Nielsen, Niels Chr.

    2012-01-01

    We present a novel sampling strategy, interleaving acquisition of multiple NMR spectra by exploiting initial polarization subsequently from 1H and 2H spins, taking advantage of their different T1 relaxation times. Different 1H- and 2H-polarization based spectra are in this way simultaneously recorded improving either information content or sensitivity by adding spectra. The so-called Relaxation-optimized Acquisition of Proton Interleaved with Deuterium (RAPID) 1H → 13C/ 2H → 13C CP/MAS multiple-acquisition method is demonstrated by 1D and 2D experiments using a uniformly 2H, 15N, 13C-labeled α-spectrin SH3 domain sample with all or 30% back-exchanged labile 2H to 1H. It is demonstrated how 1D 13C CP/MAS or 2D 13C- 13C correlation spectra initialized with polarization from either 1H or 2H may be recorded simultaneously with flexibility to be added or used individually for spectral editing. It is also shown how 2D 13C- 13C correlation spectra may be recorded interleaved with 2H- 13C correlation spectra to obtain 13C- 13C correlations along with information about dynamics from 2H sideband patterns.

  11. Plasma harmonics

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  12. Volumetric Properties and Fluid Phase Equilibria of CO2 + H2O

    Capobianco, Ryan [Virginia Polytechnic Institute and State University; Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Bodnar, Robert [Virginia Polytechnic Institute and State University

    2013-01-01

    The need for accurate modeling of fluid-mineral processes over wide ranges of temperature, pressure and composition highlighted considerable uncertainties of available property data and equations of state, even for the CO2 + H2O binary system. In particular, the solubility, activity, and ionic dissociation equilibrium data for the CO2-rich phase, which are essential for understanding dissolution/precipitation, fluid-matrix reactions, and solute transport, are uncertain or missing. In this paper we report the results of a new experimental study of volumetric and phase equilibrium properties of CO2 + H2O, to be followed by measurements for bulk and confined multicomponent fluid mixtures. Mixture densities were measured by vibrating tube densimetry (VTD) over the entire composition range at T = 200 and 250 C and P = 20, 40, 60, and 80 MPa. Initial analysis of the mutual solubilities, determined from volumetric data, shows good agreement with earlier results for the aqueous phase, but finds that the data of Takenouchi and Kennedy (1964) significantly overestimated the solubility of water in supercritical CO2 (by a factor of more than two at 200 C). Resolving this well-known discrepancy will have a direct impact on the accuracy of predictive modeling of CO2 injection in geothermal reservoirs and geological carbon sequestration through improved equations of state, needed for calibration of predictive molecular-scale models and large-scale reactive transport simulations.

  13. Affordable uniform isotope labeling with 2H, 13C and 15N in insect cells

    For a wide range of proteins of high interest, the major obstacle for NMR studies is the lack of an affordable eukaryotic expression system for isotope labeling. Here, a simple and affordable protocol is presented to produce uniform labeled proteins in the most prevalent eukaryotic expression system for structural biology, namely Spodoptera frugiperda insect cells. Incorporation levels of 80 % can be achieved for 15N and 13C with yields comparable to expression in full media. For 2H,15N and 2H,13C,15N labeling, incorporation is only slightly lower with 75 and 73 %, respectively, and yields are typically twofold reduced. The media were optimized for isotope incorporation, reproducibility, simplicity and cost. High isotope incorporation levels for all labeling patterns are achieved by using labeled algal amino acid extracts and exploiting well-known biochemical pathways. The final formulation consists of just five commercially available components, at costs 12-fold lower than labeling media from vendors. The approach was applied to several cytosolic and secreted target proteins

  14. Influence of high absorbed irradiation doses on conversion of CO2-H2S mixtures

    It was investigated the CO2-H2S mixture radiolysis at large absorbed irradiation doses. The observed high yield of final products in this system (Gpr.≥10.0) gives the possibility to consider the radiolytic hydrogen sulphide decomposition as one of the variants of purification of hydrogen sulphide containing residues of natural gas with a simultaneous production of sulphur and synthesis-gas (CO2). It has been show that at dose MGy∼16 % of initial product convert into synthesis-gas and sulfur. The mechanism of radiolytic conversion is discussed and the observed yield of hydrogen made G0(H2)=11.0±0.8 that considerably excesses G0(H2) at radiolysis of pure H2S(G0(H2)=7.5±0.5). Accumulation of carbon monoxide is described with 5 % accuracy with parabola of the second order: [CO] (-0.00082+0.359D-0.0013D2)·1019 mol/cm3 the initial yield of CO production for the given mixture is equal 3.59 which is G0(CO) = 4.5 in recalculation upon pure carbon dioxide. It has been established that the radiolytic reprocessing of acidic components of natural gas (CO2, H2S) gives the possibility to product sulphur and synthesis gas with yield to 30 vol.% (D=10 MGy), and the opportunity of simultaneous decision of ecological problems

  15. Emission spectroscopic study of the system F2-H2 in the shock tube

    In a shock tube Ar-F2-H2-mixtures, containing 0.2% F2 and 0.2% H2, were heated up to temperatures of approx. 830 respectively 940 K. The pressures amounted to 4.0 respectively 3.6 bar. The following reaction was observed via the radiation emission of the vibrational excited HF-molecules. The spectral range from 660 to 960 nm was investigated. From these measurements it was possible to determine the population numbers of discrete vibrational levels (v = 3,...,9) of the HF-molecule. Chemical kinetic calculations were carried out in order to evaluate from these measurements informations on rate coefficients of certain elementary reactions. By adapting the calculations to the measurements it was found among others, that VVT-processes between HF and HF do occur much faster at higher vibrational quantum numbers than originally supposed. Furthermore, statements could be made on VT-processes between HF and Ar as well as on the pumping reaction H + F2 → HF + F. (orig.)

  16. Emission-spectroscopic investigation of the F2-H2-system in a shock tube

    In a shock tube Ar-F2-H2-mixtures, containing 0.2% F2 and 0.2% H2, were heated up to temperatures of appr. 830 resp. 940 K. The pressures amounted to 4.0 resp. 3.6 bar. The reaction between H2 and F2 was observed via the radiation emission of the vibrational excited HF-molecules. The spectral range from 660 to 960 nm was investigated. From these measurements it was possible to determine population numbers of discrete vibrational levels (v = 3,...9) of the HF-molecule. Chemical kinetic calculations were carried out in order to evaluate from these measurements informations on rate coefficients of certain elementary reactions. By adapting the calculations to the measurements it was found among others, that VVT-relaxation processes between HF and HF occur much faster at higher vibrational quantum numbers than it was supposed up to now. Furthermore, some preliminary results were obtained on VT-relaxation processes between HF and Ar as well as on the pumping reaction H + F2 → HF + F. (orig.)

  17. THE COSMIC DECLINE IN THE H2/H I RATIO IN GALAXIES

    We use a pressure-based model for splitting cold hydrogen into its atomic (H I) and molecular (H2) components to tackle the co-evolution of H I, H2, and star formation rates (SFR) in ∼3 x 107 simulated galaxies in the Millennium simulation. The main prediction is that galaxies contained similar amounts of H I at redshift z ∼ 1-5 than today, but substantially more H2, in quantitative agreement with the strong molecular line emission already detected in a few high-redshift galaxies and approximately consistent with inferences from studies of the damped Lyman-α absorbers seen in the spectra of quasars. The cosmic H2/H I ratio is predicted to evolve monotonically as ΩH2/ΩHI∝(1+z)1.6. This decline of the H2/H I ratio as a function of cosmic time is driven by the growth of galactic disks and the progressive reduction of the mean cold gas pressure. Finally, a comparison between the evolutions of H I, H2, and SFRs reveals two distinct cosmic epochs of star formation: an early epoch (z ∼> 3), driven by the evolution of ΩHI+H2(z), and a late epoch (z ∼H2(z)/ΩHI(z).

  18. Redetermination of [EuCl2(H2O6]Cl

    Frank Tambornino

    2014-06-01

    Full Text Available The crystal structure of the title compound, hexaaquadichloridoeuropium(III chloride, was redetermined with modern crystallographic methods. In comparison with the previous study [Lepert et al. (1983. Aust. J. Chem. 36, 477–482], it could be shown that the atomic coordinates of some O atoms had been confused and now were corrected. Moreover, it was possible to freely refine the positions of the H atoms and thus to improve the accurracy of the crystal structure. [EuCl2(H2O6]Cl crystallizes with the GdCl3·6H2O structure-type, exhibiting discrete [EuCl2(H2O6]+ cations as the main building blocks. The main blocks are linked with isolated chloride anions via O—H...Cl hydrogen bonds into a three-dimensional framework. The Eu3+ cation is located on a twofold rotation axis and is coordinated in the form of a Cl2O6 square antiprism. One chloride anion coordinates directly to Eu3+, whereas the other chloride anion, situated on a twofold rotation axis, is hydrogen bonded to six octahedrally arranged water molecules.

  19. Trojan Horse particle invariance for 2H(d,p3H reaction: a detailed study

    Pizzone R.G.

    2014-03-01

    Full Text Available In the last decades the Trojan Horse method has played a crucial role for the measurement of several charged particle induced reactions cross sections of astrophysical interest. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The Trojan Horse nucleus invariance for the binary d(d,pt reaction was therefore tested using the quasi free 2H(6Li, pt4He and 2H(3He,ptH reactions after 6Li and 3He break-up, respectively. The astrophysical S(E-factor for the d(d,pt binary process was then extracted in the framework of the Plane Wave Approximation applied to the two different break-up schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement confirms the applicability of the plane wave approximation and suggests the independence of binary indirect cross section on the chosen Trojan Horse nucleus also for the present case.

  20. Trojan Horse particle invariance for 2H(d,p)3H reaction: a detailed study

    Pizzone, R. G.; Spitaleri, C.; Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L.; La Cognata, M.; Lamia, L.; Rinollo, A.; Spartá, R.; Tumino, A.

    2014-03-01

    In the last decades the Trojan Horse method has played a crucial role for the measurement of several charged particle induced reactions cross sections of astrophysical interest. To better understand its cornerstones and its applications to physical cases many tests were performed to verify all its properties and the possible future perspectives. The Trojan Horse nucleus invariance for the binary d(d,p)t reaction was therefore tested using the quasi free 2H(6Li, pt)4He and 2H(3He,pt)H reactions after 6Li and 3He break-up, respectively. The astrophysical S(E)-factor for the d(d,p)t binary process was then extracted in the framework of the Plane Wave Approximation applied to the two different break-up schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement confirms the applicability of the plane wave approximation and suggests the independence of binary indirect cross section on the chosen Trojan Horse nucleus also for the present case.

  1. Bound and continuum states of molecular anions C2H- and C3N-

    Harrison, Stephen; Tennyson, Jonathan

    2011-02-01

    Recently a number of molecular anions, closed-shell linear carbon chains of the form CnH- and CnN-, have been detected in space. The molecules C2H- and C3N- are investigated by using the R-matrix method to consider electron scattering from the corresponding neutral targets. Initial target calculations are conducted and refined in order to produce target state characteristics similar to the experimental data. A number of different scattering models are tested including static exchange and close-coupling models, and the use of Hartree-Fock or natural orbitals in the close-coupling calculations. The calculations concentrate on bound and resonances states for the anions as well as eigenphase sums, elastic cross-sections and electronic excitation cross-sections for electron collisions with the neutral. It is found that electronic resonances are all too high in energy to be important for anion formation in the interstellar medium. However, C3N-, unlike C2H-, supports a number of very weakly bound excited states, which may well provide the route to electron attachment for this system.

  2. Solar photocatalytic degradation of isoproturon over TiO2/H-MOR composite systems

    The photocatalytic degradation and mineralization of isoproturon herbicide was investigated in aqueous solution containing TiO2 over H-mordenite (H-MOR) photocatalysts under solar light. The catalysts are characterized by X-ray diffraction (XRD), UV-Vis diffused reflectance spectra (UV-Vis DRS), Fourier transform-infra red spectra (FT-IR) and scanning electron microscopy (SEM) techniques. The effect of TiO2, H-MOR support and different wt% of TiO2 over the support on the photocatalytic degradation and influence of parameters such as TiO2 loading, catalyst amount, pH and initial concentration of isoproturon on degradation are evaluated. 15 wt% TiO2/H-MOR composite is found to be optimum. The degradation reaction follows pseudo-first order kinetics and is discussed in terms of Langmuir-Hinshelwood (L-H) kinetic model. The extent of isoproturon mineralization studied with chemical oxygen demand (COD) and total organic carbon (TOC) measurements and ∼80% mineralization occurred in 5 h. A plausible mechanism is proposed based on the intermediates identified by liquid chromatography-mass spectroscopy (LC-MS)

  3. Graphite Nanostructures Produce in the Acetilene, Argon-Acetylene and Argon-Hydrogen-Acetylene Plasmas

    Grigonis A.; Marcinauskas L.; Carnauskas M.; Kaliasas R.

    2012-01-01

    The amorphous carbon films were deposited on silicon-metal substrates by plasma jet chemical vapor deposition (PJCVD) and plasma enchanted CVD (PECVD). PJCVD carbon coatings have been prepared at atmospheric pressure in Ar/ C2H2 and Ar/H2/C2H2 mixtures. The films prepared in Ar/C2H2 plasma are at-tributed to graphite-like carbon films. Addition of the hydrogen decreases growth rate and the surface roughness of the coatings, but coatings have low fraction of oxygen (~5 at.%) The formation of t...

  4. Effect of Sterol Structure on Chain Ordering of an Unsaturated Phospholipid: A 2H-NMR Study of POPC/Sterol Membranes

    Shaghaghi, Mehran; Thewalt, Jenifer; Zuckermann, Martin

    2012-10-01

    The physical properties of biological membranes are considerably altered by the presence of sterols. In particular, sterols help to maintain the integrity of the cell by adjusting the fluidity of the plasma membrane. Cholesterol is in addition an important component of lipid rafts which are hypothesized to compartmentalize the cell membrane surface thereby making it possible for certain proteins to function. Using 2H-NMR spectroscopy, we studied the effect of a series of different sterols on the chain ordering of POPC, an unsaturated phospholipid present in eukaryotic cell membranes. We were able to assigned specific roles to the structural differences between the sterols by comparing the manner in which they affect the average lipid chain conformation of POPC.

  5. Pulsed RF Plasma Source for Materials Processing

    Nasiruddin, Abutaher Mohammad

    A pulsed rf plasma source was evaluated for materials processing. A pulsed rf discharge of carbon tetrafluoride (CF_4), sulfur hexafluoride (SF _6), oxygen (O_2), or acetylene (C_2H_2 ) created the plasmas. The frequency and duration of the rf discharge were about 290 kHz and 30 musec, respectively. The repetition rate was 1 discharge per minute. Plasma diagnostics included Langmuir probes, a photodiode dectector, an optical multichannel analyzer (OMA), and a microwave interferometer. Langmuir probe measurements showed that at a position 67 cm away from the rf coil, CF_4 plasma arrived in separate packets. Plasma densities and electron temperatures at this position were in the range 4 times 10^{11} cm ^{-3} to 1.8 times 10^{13} cm ^{-3} and 2 eV to 8.3 eV, respectively. The OMA measurements identified neutral atomic fluorine in the CF_4 plasma and neutral atomic oxygen in the O_2 plasma. A plasma slab model of the microwave interferometer was applied to predict the interferometer response. The measured response was found to be almost identical to the predicted response. The influence of different reactor parameters on plasma parameters was studied. Metal barriers of different geometry were used to control the ratio of charged particles to atomic neutrals in the plasma chamber. Four plasma structures were identified: precursor plasma, shock induced plasma, driver plasma, and delayed glow plasma. Pulsed CF _4 and SF_6 plasmas were used to etch silicon dioxide (SiO_2 ) grown on silicon wafers. The SF_6 plasma etched SiO_2 at a rate of about 0.71 A per discharge and the CF_4 plasma deposited a non-uniform film (possibly polymer) instead of etching. The C_2H _2 plasma deposited plasma polymerized acetylene on a KBr pellet with a deposition rate of 127 A per discharge. An FT-IR spectrum of the deposited film showed that carbon -to-carbon double bonds as well as carbon-to-hydrogen bonds were present. This device can be used in plasma assisted deposition and/or synthesis

  6. Sterilization Effect of Wet Oxygen Plasma in the Bubbling Method.

    Tamazawa, Kaoru; Shintani, Hideharu; Tamazawa, Yoshinori; Shimauchi, Hidetoshi

    2015-01-01

    A new low-temperature sterilization method to replace the ethylene oxide gas sterilization is needed. Strong bactericidal effects of OH and O2H radicals are well known. The purpose of this study was to evaluate the sterilization effect of wet oxygen ("O2+H2O") plasma in the bubbling method, confirming the effect of humidity. Sterility assurance was confirmed by using a biological indicator (Geobacillus stearothermophilus ATCC7953, Namsa, USA). One hundred and eight samples (10(5) spores/carrier) were divided into three groups of 36 in each for treatment with a different type of gas (O2, O2+H2O, Air+H2O). Plasma processing was conducted using a plasma ashing apparatus (13.56 MHz, PACK-3(®), Y. A. C., Japan) under various gas pressures (13, 25, 50 Pa) and gas flows (50, 100, 200 sccm). Fixed plasma treatment parameters were power at 150 W, temperature of 60 ℃, treatment time of 10 min. The samples after treatment were incubated in trypticase soy broth at 58 ℃ for 72 h. The negative culture rate in the "O2+H2O" group was significantly (Mantel-Haenszel procedure, psterilization effect of the "O2+H2O" group depends on the bubbling method which is the method of introducing vapor into the chamber. The bubbling method seems able to generate OH and O2H radicals in a stable way. PMID:26699857

  7. Modeling Ice Giant Interiors Using Constraints on the H2-H2O Critical Curve

    Bailey, E.; Stevenson, D. J.

    2015-12-01

    We present a range of models of Uranus and Neptune, taking into account recent experimental data (Bali, 2013) implying the location of the critical curve of the H2-H2O system at pressures up to 2.6 GPa. The models presented satisfy the observed total mass of each planet and the radius at the observed 1-bar pressure level. We assume the existence of three regions at different depths: an outer adiabatic envelope composed predominately of H2 and He, with a helium mass fraction 0.26, a water-rich layer including varied amounts of rock and hydrogen, and a chemically homogeneous rock core. Using measured rotation rates of Uranus and Neptune, and a density profile obtained for each model using constituent equations of state and the assumption of hydrostatic equilibrium, we calculate the gravitational harmonics J2 and J4 for comparison with observed values as an additional constraint. The H2-H2O critical curve provides information about the nature of the boundary between the outer, hydrogen-rich envelope and underlying water-rich layer. The extrapolated critical curve for hydrogen-water mixtures crosses the adiabat of the outer atmospheric shell in these models at two depths, implying a shallow outer region of limited miscibility, an intermediate region between ~90 and 98 percent of the total planet radius within which hydrogen and water can mix in all proportions, and another, deeper region of limited miscibility at less than ~90 percent of the total planet radius. The pressure and temperature of the gaseous adiabatic shell at the depth of the shallowest extent of the water-rich layer determines whether a gradual compositional transition or an ocean surface boundary may exist at depth in these planets. To satisfy the observed J2, the outer extent of the water-rich layer in these models must be located between approximately 80 and 85 percent of the total planet radius, within the deep region of limited H2-H2O miscibility, implying an ocean surface is possible within the

  8. SNF2H interacts with XRCC1 and is involved in repair of H2O2-induced DNA damage.

    Kubota, Yoshiko; Shimizu, Shinji; Yasuhira, Shinji; Horiuchi, Saburo

    2016-07-01

    The protein XRCC1 has no inherent enzymatic activity, and is believed to function in base excision repair as a dedicated scaffold component that coordinates other DNA repair factors. Repair foci clearly represent the recruitment and accumulation of DNA repair factors at sites of damage; however, uncertainties remain regarding their organization in the context of nuclear architecture and their biological significance. Here we identified the chromatin remodeling factor SNF2H/SMARCA5 as a novel binding partner of XRCC1, with their interaction dependent on the casein kinase 2-mediated constitutive phosphorylation of XRCC1. The proficiency of repairing H2O2-induced damage was strongly impaired by SNF2H knock-down, and similar impairment was observed with knock-down of both XRCC1 and SNF2H simultaneously, suggesting their role in a common repair pathway. Most SNF2H exists in the nuclear matrix fraction, forming salt extraction-resistant foci-like structures in unchallenged nuclei. Remarkably, damage-induced formation of both PAR and XRCC1 foci depended on SNF2H, and the PAR and XRCC1 foci co-localized with the SNF2H foci. We propose a model in which a base excision repair complex containing damaged chromatin is recruited to specific locations in the nuclear matrix for repair, with this recruitment mediated by XRCC1-SNF2H interaction. PMID:27268481

  9. Satellite observations of ethylene (C2H4) from the Aura Tropospheric Emission Spectrometer: A scoping study

    Dolan, Wayana; Payne, Vivienne H.; Kualwik, Susan S.; Bowman, Kevin W.

    2016-09-01

    We present a study focusing on detection and initial quantitative estimates of ethylene (C2H4) in observations from the Tropospheric Emission Spectrometer (TES), a Fourier transform spectrometer aboard the Aura satellite that measures thermal infrared radiances with high spectral resolution (0.1 cm-1). We analyze observations taken in support of the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission and demonstrate the feasibility of future development of C2H4 into a TES standard product. In the Northern Hemisphere, C2H4 is commonly associated with boreal fire plumes, motor vehicle exhaust and petrochemical emissions. It has a short lifetime (∼14-32 h) in the troposphere due to its reaction with OH and O3. Chemical destruction of C2H4 in the atmosphere leads to the production of ozone and other species such as carbon monoxide (CO) and formaldehyde. Results indicate a correlation between C2H4 and CO in boreal fire plumes. Quantitative C2H4 estimates are sensitive to assumptions about the plume height and width. We find that C2H4 greater than 2-3 ppbv can be detected in a single TES observation (for a fire plume at 3 km altitude and 1.5 km width). Spatial averaging will be needed for surface-peaking profiles where TES sensitivity is lower.

  10. 5-[4-(1H-Imidazol-1-ylphenyl]-2H-tetrazole dihydrate

    Yan-Hua Zhang

    2011-06-01

    Full Text Available In the title compound, C10H8N6·2H2O, the central aromatic ring makes dihedral angles of 23.59 (15 and 16.99 (16° with the terminal imidazole and tetrazole rings, respectively, which are themselves almost coplanar [dihedral angle = 6.61 (18°]. Two H atoms of the two water molecules are half occupied. In the crystal packing, weak intermolecular O—H...N, O—H...O and N—H...N hydrogen bonds and π–π stacking interactions [centroid–centroid distances of 3.73 (4 Å between benzene rings and 3.66 (3 Å between imidazole and tetrazole rings] are observed.

  11. Photophysical Property of Ternary Complex Eu(DPHA)3*Phen*2H20

    王明召; 王淑贤; 蔡冠梁

    2001-01-01

    One ternary complex of europium with the plant growth regulator HDPHA (2-Hydroxydiphenyl acetic acid) and Phen (1,10-Phenanthroline), Eu(DPHA)3*Phen*2H2O, was synthesized and characterized by the elemental analysis and DTA-TG measurement. The photophysical property of the complex was investigated by means of IR spectra, Raman spectrum and laser-exited, high-resolved excitation and emission spectra as well as time-resolved luminescence spectra. The luminescence spectra reveal four Eu3+ sites with energy difference within 25 cm-1 and local symmetries of C1 or C2 or Cs in the complex. The energy transfer among the Eu3+ sites is observed. The 7FJ sublevel splitting of the Eu3+ ion is discussed.

  12. Crystal structure of erbium trichloroacetate Er(CCl3COO)·2H2O

    X-ray structure study of Er(CCl3COO)3x2H2O crystals is conducted (SYNTEX P21 autodiffractometer, MoKα-radiation). The crystals are of triclinic syngony: a11.697 (4), b=12.790 (4), c=15223 (4) A, α=70.67 (3), β=77.80 (3), γ=6561 (3)deg; space group P1, Z=4. There are two crystallographically independent types of erbium atoms with coordination numbers 7 and 8, respectively, in the unit cell. These atoms are linked by tetra- and double-carboxylated cross-links in the endless chains, while water molecules complete the metal coordination polyhedron is within 2.259-2.393 A interval, while in seven-coordination - within 2.229-2.267 A interval. Er-H2O distances constitute 2.389-2.534 A

  13. Synthesis of novel 2H,5H-Dihydrofuran-3-yl Ketones via ISNC reactions

    Grandbois, Matthew L.; Betsch, Kelsie J.; Buchanan, William D.; Duffy-Matzner, Jetty L.

    2009-01-01

    Unique 1-[2H,5H-dihydrofur-3-yl]ketones have been synthesized from propargylic nitroethers via intramolecular cycloadditions involving silyl nitronates. Various substituent groups were placed on the 2 and 5 positions of the dihydrofuran rings. We examined the scope of the long-range coupling in proton NMR of the oxo-dihydrofuran products. The identities of the diastereomers resulting from the Michael Addition/cycloaddition reactions were tentatively assigned for the first time. CAChe MNDO PM5 and CONFLEX programs were engaged to assist with the identification of these stereoisomers. The reaction times and conditions for these oxo-dihydrofurans were found to be different than that of the published dihydrofuranals, which led us to propose a different mechanism. PMID:20161382

  14. Photon stimulated ion desorption from polyatomic molecules in the VUV:C2H4-graphite

    We have investigated photon stimulated ion desorption from C2H4 physisorbed on highly oriented pyrolytic graphite using VUV synchrotron radiation in the energy range 13-40 eV. In contrast with gas phase photodissociation measurements, only H+ ions are detected. This result is attributed to the image potential barrier to desorption from the surface and the unequal distribution of kinetic energy amongst the molecular photofragments. The yield of desorbed H+ ions shows a threshold at 20.5 eV and a resonance at 24 eV and appears to be enhanced in the monolayer regime. This behaviour differs significantly from that of the gas phase, and is attributed to selective quenching of excited molecular electronic states on the surface and to chemical reactions between specific molecular dissociated fragments and the substrate. (author). Letter-to-the-editor

  15. Na and Cs intercalation of 2H-TaSe2 studied by photoemission

    The electronic structure of the layered compound 2H-TaSe2 has been studied using angle-resolved photoemission before and after in situ intercalation with Na and Cs. Core level spectra verified that Na and Cs both intercalate easily at room temperature, with only small amounts remaining on the surface. Valence band spectra revealed changes in the electronic band structure which were much more extensive than predicted by the rigid band model, but which were in reasonable agreement with theoretical bands calculated by the LAPW method. Some discrepancies between the experimental and calculated results are probably due to intercalation induced changes in the stacking of host layers. A general similarity with results from transition metal dichalcogenides with 1T structure indicates that the intercalation properties are not critically dependent on the internal structure of the host layers. (author)

  16. 2p-2h excitations in neutrino scattering: angular distribution and frozen approximation

    Simo, I Ruiz; Amaro, J E; Barbaro, M B; Caballero, J A; Donnelly, T W

    2015-01-01

    We study the phase-space dependence of 2p-2h excitations in neutrino scattering using the relativistic Fermi gas model. We follow a similar approach to other authors, but focusing in the phase-space properties, comparing with the non-relativistic model. A careful mathematical analysis of the angular distribution function for the outgoing nucleons is performed. Our goals are to optimize the CPU time of the 7D integral to compute the hadron tensor in neutrino scattering, and to conciliate the different relativistic and non relativistic models by describing general properties independently of the two-body current. For some emission angles the angular distribution becomes infinite in the Lab system, and we derive a method to integrate analytically around the divergence. Our results show that the frozen approximation, obtained by neglecting the momenta of the two initial nucleons inside the integral of the hadron tensor, reproduces fairly the exact response functions for constant current matrix elements.

  17. RNF20-SNF2H Pathway of Chromatin Relaxation in DNA Double-Strand Break Repair

    Akihiro Kato

    2015-07-01

    Full Text Available Rapid progress in the study on the association of histone modifications with chromatin remodeling factors has broadened our understanding of chromatin dynamics in DNA transactions. In DNA double-strand break (DSB repair, the well-known mark of histones is the phosphorylation of the H2A variant, H2AX, which has been used as a surrogate marker of DSBs. The ubiquitylation of histone H2B by RNF20 E3 ligase was recently found to be a DNA damage-induced histone modification. This modification is required for DSB repair and regulated by a distinctive pathway from that of histone H2AX phosphorylation. Moreover, the connection between H2B ubiquitylation and the chromatin remodeling activity of SNF2H has been elucidated. In this review, we summarize the current knowledge of RNF20-mediated processes and the molecular link to H2AX-mediated processes during DSB repair.

  18. Tris[2-(2H-indazol-2-ylethyl]amine

    Saúl Ovalle

    2012-06-01

    Full Text Available The title tertiary amine, C27H27N7, a potential tripodal ligand for coordination chemistry, crystallizes with the central N atom located on a threefold axis of a trigonal cell. The gauche conformation of the N(amime—CH2—CH2—N(indazole chain [torsion angle = −64.2 (2°] places the pendant 2H-indazole heterocycles surrounding the symmetry axis, affording a claw-like shaped molecule. Two symmetry-related indazole planes in the molecule make an acute angle of 60.39 (4°. The lone pair of the tertiary N atom is located inside the cavity, and should thus be inactive (as a ligand. In the crystal, neither significant π–π nor C—H...π interactions between molecules are found.

  19. Direct growth of graphene on gallium nitride using C2H2 as carbon source

    Wang, Bing; Zhao, Yun; Yi, Xiao-Yan; Wang, Guo-Hong; Liu, Zhi-Qiang; Duan, Rui-Rei; Huang, Peng; Wang, Jun-Xi; Li, Jin-Min

    2016-04-01

    Growing graphene on gallium nitride (GaN) at temperatures greater than 900°C is a challenge that must be overcome to obtain high quality of GaN epi-layers. We successfully met this challenge using C2H2 as the carbon source. We demonstrated that graphene can be grown both on copper and directly on GaN epi-layers. The Raman spectra indicated that the graphene films were about 4-5 layers thick. Meanwhile, the effects of the growth temperature on the growth of the graphene films were systematically studied, and 830°C was found to be the optimum growth temperature. We successfully grew high-quality graphene films directly on gallium nitride.

  20. Resonances in the reaction ortho- and para- D2 + H at temperatures below 10 K

    Simbotin, I.; Côté, R.

    2016-05-01

    In a previous study we reported cross sections for the reaction H2 + D in the temperature regime 10-6 D2 + H for vibrationally excited ortho- and para- D2, and compare and contrast these results with those for H2 + D. We remark that this benchmark system is a prototypical example of reactions with a strong barrier, which have very small cross sections in the cold and ultracold regimes. However, shape resonances can enhance the reaction cross sections by orders of magnitude for temperatures around and below T = 1 K. Moreover, resonant features would provide stringent tests for quantum chemistry calculations of potential energy surfaces. Partial support from the US Army Research Office (Grant No. W911NF-13-1-0213).

  1. Dual-laser absorption spectroscopy of C2H2 at 1.4 μ m

    Fasci, E.; Odintsova, T. A.; Castrillo, A.; De Vizia, M. D.; Merlone, A.; Bertiglia, F.; Moretti, L.; Gianfrani, L.

    2016-04-01

    Spectroscopic parameters (line intensity factor, pressure self-broadening, and shifting coefficients) of C2H2 at 1.4 μ m were accurately measured using a dual-laser approach, based upon the technique of optical phase locking. This generated an absolute frequency scale underneath the absorption spectra. A pair of extended-cavity diode lasers was used. One of them, the probe laser, is forced to maintain a precise frequency offset from a reference laser, which is an optical frequency standard based on noise-immune cavity-enhanced optical heterodyne molecular spectroscopy. Laser-gas interaction takes place inside an isothermal multipass cell that is stabilized at the temperature of the triple point of water. The fidelity in the observation of the shape associated to the Pe(14) line of the 2 ν3+ν5 band allowed us to measure the spectroscopic parameters, with a global uncertainty for the line strength of 0.22%.

  2. Ethyl (4-{[(diethylcarbamothioylsulfanyl]methyl}-2-oxo-2H-chromen-7-ylcarbamate

    K. R. Roopashree

    2014-02-01

    Full Text Available In the title compound, C18H22N2O4S2, the 2H-chromene ring system is essentially planar (r.m.s. deviation = 0.012 Å. The molecular conformation is stabilized by a C—H...O hydrogen bond. In the crystal, N—H...S and C—H...O hydrogen bonds occur, the former enclosing an R22(22 ring motif, and lead to the formation of a two-dimensional slab-like network lying parallel to (10-1. π–π interactions are observed between inversion-related aromatic rings [shortest centroid–centroid distance = 3.6300 (11 Å].

  3. The p-shell nuclei in a(0+2)h-bar ω model space

    In this thesis the phenomenological approach is used to obtain a microscopic description for nuclei with A = 4-16, the p-shell nuclei. Despite the successes of these earlier calculations a number of discrepancies between theory and experiment remained. In particular the existence of intruder states was an unsolved problem. These are low-lying states in the spectrum which could not be reproduced in the calculations. However, one assumed that they could be described in larger model spaces. It is the topic of this thesis, which is a natural continuation of the earlier calculations: the p-shell nuclei in a (0+2) h.barω model space. Chapter 2 defines the (0+2) h.barω model space and describes a translation invariant interaction, which is parametrized by talmi integrals. Chapter 3 discusses the fitting procedure in detail. It is shown how static moments can be included in this procedure. Furthermore two kinds of errors for the parameters are defined. They give an indication about the accuracy of the parameter values. The strategy to obtain the interaction is also described in this chapter. Finally the resulting interaction is presented and followed by a discussion about the values of the parameters. Chapter 4 shows the obtained spectra. They are compared with experimental data. Besides it is explained why the 'mixing catastrophe' does not appear with the present interaction parameters. The interesting phenomenon of radially excitated states is discussed well. In chapter 5 the structure of the obtained wave functions is presented in more detail. In chapter 6 the obtained values for several observables are given. These are the charge r.m.s. radii, static moments, M1- and E2-transition strenghts, log ft values and form factors for electron scattering. All calculated observables are compared with the experimental values. Chapter 7 contains the main conclusions which can be drawn from the present investigation. (author). 77 refs.; 75 figs.; 9 tabs

  4. Interplay of charge density wave and multiband superconductivity in 2H-PdxTaSe2.

    Bhoi, D; Khim, S; Nam, W; Lee, B S; Kim, Chanhee; Jeon, B-G; Min, B H; Park, S; Kim, Kee Hoon

    2016-01-01

    2H-TaSe2 has been one of unique transition metal dichalcogenides exhibiting several phase transitions due to a delicate balance among competing electronic ground states. An unusual metallic state at high-T is sequentially followed by an incommensurate charge density wave (ICDW) state at ≈122 K and a commensurate charge density wave (CCDW) state at ≈90 K, and superconductivity at TC ~ 0.14 K. Upon systematic intercalation of Pd ions into TaSe2, we find that CCDW order is destabilized more rapidly than ICDW to indicate a hidden quantum phase transition point at x ~ 0.09-0.10. Moreover, TC shows a dramatic enhancement up to 3.3 K at x = 0.08, ~24 times of TC in 2H-TaSe2, in proportional to the density of states N(EF). Investigations of upper critical fields Hc2 in single crystals reveal evidences of multiband superconductivity as temperature-dependent anisotropy factor γH = , quasi-linear increase of , and an upward, positive-curvature in near TC. Furthermore, analysis of temperature-dependent electronic specific heat corroborates the presence of multiple superconducting gaps. Based on above findings and electronic phase diagram vs x, we propose that the increase of N(EF) and effective electron-phonon coupling in the vicinity of CDW quantum phase transition should be a key to the large enhancement of TC in PdxTaSe2. PMID:27045426

  5. Cloning and characterization of a Ca(2+)/H(+) exchanger from the halophyte Salicornia europaea L.

    Zhang, Liquan; Hao, Jinfeng; Bao, Mulan; Hasi, Agula; Niu, Yiding

    2015-11-01

    The calcium ion (Ca(2+)), which functions as a second messenger, plays an important role in plants' responses to various abiotic stresses, and Ca(2+)/H(+) exchangers (CAXs) are an important part of this process. In this study, we isolated and characterized a putative Ca(2+)/H(+) exchanger gene (SeCAX3) from Salicornia europaea L., a succulent, leafless euhalophyte. The SeCAX3 open reading frame was 1368 bp long and encoded a 455-amino-acid polypeptide that showed 67.9% similarity to AtCAX3. SeCAX3 was expressed in the shoots and roots of S. europaea. Expression of SeCAX3 was up-regulated by Ca(2+), Na(+), sorbitol, Li(+), abscisic acid, and cold treatments in shoots, but down-regulated by Ca(2+), sorbitol, abscisic acid, and cold treatments in roots. When SeCAX3 was transformed into a Ca-sensitive yeast strain, the transformed cells were able to grow in the presence of 200 mM Ca(2+). Furthermore, SeCAX3 conferred drought, salt, and cold tolerance in yeast. Compared with the control strains, the yeast transformants expressing SeCAX3 were able to grow well in the presence of 30 mM Li(+), 150 mM Mg(2+), or 6 mM Ba(2+). These results showed that the expression of SeCAX3 in yeast suppressed its Ca(2+) hypersensitivity and conferred tolerance to Mg(2+) and Ba(2+). Together, these findings suggest that SeCAX3 might be a Ca(2+) transporter that plays a role in regulating cation tolerance and the responses of S. europaea to various abiotic stresses. PMID:26332662

  6. Protein dynamics in the solid state from 2H NMR line shape analysis: a consistent perspective.

    Meirovitch, Eva; Liang, Zhichun; Freed, Jack H

    2015-02-19

    Deuterium line shape analysis of CD3 groups has emerged as a particularly useful tool for studying microsecond-millisecond protein motions in the solid state. The models devised so far consist of several independently conceived simple jump-type motions. They are comprised of physical quantities encoded in their simplest form; improvements are only possible by adding yet another simple motion, thereby changing the model. The various treatments developed are case-specific; hence comparison among the different systems is not possible. Here we develop a new methodology for (2)H NMR line shape analysis free of these limitations. It is based on the microscopic-order-macroscopic-disorder (MOMD) approach. In MOMD motions are described by diffusion tensors, spatial restrictions by potentials/ordering tensors, and geometric features by relative tensor orientations. Jump-type motions are recovered in the limit of large orientational potentials. Model improvement is accomplished by monitoring the magnitude, symmetry, and orientation of the various tensors. The generality of MOMD makes possible comparison among different scenarios. CD3 line shapes from the Chicken Villin Headpiece Subdomain and the Streptomyces Subtilisin Inhibitor are used as experimental examples. All of these spectra are reproduced by using rhombic local potentials constrained for simplicity to be given by the L = 2 spherical harmonics, and by axial diffusion tensors. Potential strength and rhombicity are found to be ca. 2-3 k(B)T. The diffusion tensor is tilted at 120° from the C-CD3 axis. The perpendicular (parallel) correlation times for local motion are 0.1-1.0 ms (3.3-30 μs). Activation energies in the 1.1-8.0 kcal/mol range are estimated. Future prospects include extension to the (2)H relaxation limit, application to the (15)N and (13)C NMR nuclei, and accounting for collective motions and anisotropic media. PMID:25594631

  7. The photodissociation dynamics of the ethyl radical, C2H5, investigated by velocity map imaging

    The photodissociation dynamics of the ethyl radical C2H5 has been investigated by velocity map imaging. Ethyl was produced by flash pyrolysis from n-propyl nitrite and excited to the à 2A′ (3s) Rydberg state around 250 nm. The energetically most favorable reaction channel in this wavelength region is dissociation to C2H4 (ethene) + H. The H-atom dissociation products were ionized in a [1+1′] process via the 1s-2p transition. The observed translational energy distribution is bimodal: A contribution of slow H-atoms with an isotropic angular distribution peaks at low translational energies. An expectation value for the fraction of excess energy released into translation of T>= 0.19 is derived from the data, typical for statistical dissociation reactions. In addition, a fast H-atom channel is observed, peaking around 1.8 eV. The latter shows an anisotropic distribution with β= 0.45. It originates from a direct dissociation process within less than a rotational period. Time-delay scans with varying extraction voltages indicate the presence of two rates for the formation of H-atoms. One rate with a sub-nanosecond time constant is associated with H-atoms with large translational energy; a second one with a time constant on the order of 100 ns is associated with H-atoms formed with low translational energy. The data confirm and extend those from previous experiments and remove some inconsistencies. Possible mechanisms for the dissociation are discussed in light of the new results as well as previous ones.

  8. The effects of maternal anxiety during pregnancy on IGF2/H19 methylation in cord blood.

    Mansell, T; Novakovic, B; Meyer, B; Rzehak, P; Vuillermin, P; Ponsonby, A-L; Collier, F; Burgner, D; Saffery, R; Ryan, J

    2016-01-01

    Compelling evidence suggests that maternal mental health in pregnancy can influence fetal development. The imprinted genes, insulin-like growth factor 2 (IGF2) and H19, are involved in fetal growth and each is regulated by DNA methylation. This study aimed to determine the association between maternal mental well-being during pregnancy and differentially methylated regions (DMRs) of IGF2 (DMR0) and the IGF2/H19 imprinting control region (ICR) in newborn offspring. Maternal depression, anxiety and perceived stress were assessed at 28 weeks of pregnancy in the Barwon Infant Study (n=576). DNA methylation was measured in purified cord blood mononuclear cells using the Sequenom MassArray Platform. Maternal anxiety was associated with a decrease in average ICR methylation (Δ=-2.23%; 95% CI=-3.68 to -0.77%), and across all six of the individual CpG units in anxious compared with non-anxious groups. Birth weight and sex modified the association between prenatal anxiety and infant methylation. When stratified into lower (⩽3530 g) and higher (>3530 g) birth weight groups using the median birth weight, there was a stronger association between anxiety and ICR methylation in the lower birth weight group (Δ=-3.89%; 95% CI=-6.06 to -1.72%), with no association in the higher birth weight group. When stratified by infant sex, there was a stronger association in female infants (Δ=-3.70%; 95% CI=-5.90 to -1.51%) and no association in males. All the linear regression models were adjusted for maternal age, smoking and folate intake. These findings show that maternal anxiety in pregnancy is associated with decreased IGF2/H19 ICR DNA methylation in progeny at birth, particularly in female, low birth weight neonates. ICR methylation may help link poor maternal mental health and adverse birth outcomes, but further investigation is needed. PMID:27023171

  9. Technical support for a proposed decay heat guide using SAS2H/ORIGEN-S data

    Major revisions are proposed to the current US Nuclear Regulatory Commission decay heat rate guide entitled ''Regulatory Guide 3.54, Spent Fuel Heat Generation in an Independent Spent Fuel Storage Installation,'' using a new data base produced by the SAS2H analysis sequence of the SCALE-4 system. The data base for the proposed guide revision has been significantly improved by increasing the number and range of parameters that generally characterize pressurized-water-reactor (PWR) and boiling-water-reactor (BWR) spent fuel assemblies. Using generic PWR and BWR assembly models, calculations were performed with each model for six different burnups at each of three separate specific powers to produce heat rates at 20 cooling times in the range of 1 to 110 y. The proposed procedure specifies proper interpolation formulae for the tabulated heat generation rates. Adjustment formulae for the interpolated values are provided to account for differences in initial 235U enrichment and changes in the specific power of a cycle from the average value. Finally, safety factor formulae were derived as a function of burnup, cooling time, and type of reactor. The proposed guide revision was designed to be easier to use. Also, the complete data base and guide procedure is incorporated into an interactive code called LWRARC which can be executed on a personal computer. The report shows adequate comparisons of heat rates computed by SAS2H/ORIGEN-S and measurements for 10 BWR and 10 PWR fuel assemblies. The average differences of the computed minus the measured heat rates of fuel assemblies were -07 ± 2.6% for the BWR and 1.5 ± 1.3% for the PWR. In addition, a detailed analysis of the proposed procedure indicated the method and equations to be valid

  10. The First Detailed 2H and 18O Isoscapes of Freshwater in Scotland

    Meier-Augenstein, W.; Hoogewerff, J.; Kemp, H. F.; Frew, D.

    2012-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwater quality by the Scottish Environmental Protection Agency (SEPA) fulfils the legislative requirements but new scientific methods involving stable isotope analysis present an opportunity for delivering on current and nascent government policies [1] and gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and the aforementioned functions. In brief, 2H and 18O isoscapes of Scottish freshwater could be used to support fundamental and applied research in: • Climate change - These first ever isoscapes will provide a baseline against which future environmental impact can be assessed due to changes in the characteristic isotope composition of freshwater lochs and reservoirs. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish berries and Scottish Whisky. During 2011, freshwater samples were collected with the support of SEPA from more than 80 freshwater lochs and reservoirs across Scotland. Here we present the result of the 2H and 18O stable isotope analyses of these water samples together with the first isoscapes generated based on these data. [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland's National Food and Drink Policy (2009); Scottish Planning Policy Environmental Report (2009); Scottish Planning Policy (SPP) 15 Planning for Rural Development (2005); National Planning Policy Guideline (NPPG) 14: Natural Heritage (1999).

  11. Repeated Short-term (2h×14d) Emotional Stress Induces Lasting Depression-like Behavior in Mice

    Kim, Kyoung-Shim; Kwon, Hye-Joo; Baek, In-Sun; Han, Pyung-Lim

    2012-01-01

    Chronic behavioral stress is a risk factor for depression. To understand chronic stress effects and the mechanism underlying stress-induced emotional changes, various animals model have been developed. We recently reported that mice treated with restraints for 2 h daily for 14 consecutive days (2h-14d or 2h×14d) show lasting depression-like behavior. Restraint provokes emotional stress in the body, but the nature of stress induced by restraints is presumably more complex than emotional stress...

  12. Copper-catalysed asymmetric allylic alkylation of alkylzirconocenes to racemic 3,6-dihydro-2H-pyrans

    Rideau, Emeline

    2015-01-01

    Summary Asymmetric allylic alkylation is a powerful reaction that allows the enantioselective formation of C–C bonds. Here we describe the asymmetric alkylation of alkylzirconium species to racemic 3,6-dihydro-2H-pyrans. Two systems were examined: 3-chloro-3,6-dihydro-2H-pyran using linear optimization (45–93% ee, up to 33% yield, 5 examples) and 3,6-dihydro-2H-pyran-3-yl diethyl phosphate with the assistance of a design of experiments statistical approach (83% ee, 12% yield). 1H NMR spectroscopy was used to gain insight into the reaction mechanisms. PMID:26734091

  13. Full-dimensional, high-level ab initio potential energy surfaces for H2(H2O) and H2(H2O)2 with application to hydrogen clathrate hydrates

    Homayoon, Zahra; Conte, Riccardo; Qu, Chen; Bowman, Joel M.

    2015-08-01

    New, full-dimensional potential energy surfaces (PESs), obtained using precise least-squares fitting of high-level electronic energy databases, are reported for intrinsic H2(H2O) two-body and H2(H2O)2 three-body potentials. The database for H2(H2O) consists of approximately 44 000 energies at the coupled cluster singles and doubles plus perturbative triples (CCSD(T))-F12a/haQZ (aug-cc-pVQZ for O and cc-pVQZ for H) level of theory, while the database for the three-body interaction consists of more than 36 000 energies at the CCSD(T)-F12a/haTZ (aug-cc-pVTZ for O, cc-pVTZ for H) level of theory. Two precise potentials are based on the invariant-polynomial technique and are compared to computationally faster ones obtained via "purified" symmetrization. All fits use reduced permutational symmetry appropriate for these non-covalent interactions. These intrinsic potentials are employed together with existing ones for H2, H2O, and (H2O)2, to obtain full PESs for H2(H2O) and H2(H2O)2. Properties of these full PESs are presented, including a diffusion Monte Carlo calculation of the zero-point energy and wavefunction, and dissociation energy of the H2(H2O) dimer. These PESs together with an existing one for water clusters are used in a many-body representation of the PES of hydrogen clathrate hydrates, illustrated for H2@(H2O)20. An analysis of this hydrate is presented, including the electronic dissociation energy to remove H2 from the calculated equilibrium structure.

  14. Full-dimensional, high-level ab initio potential energy surfaces for H2(H2O) and H2(H2O)2 with application to hydrogen clathrate hydrates

    New, full-dimensional potential energy surfaces (PESs), obtained using precise least-squares fitting of high-level electronic energy databases, are reported for intrinsic H2(H2O) two-body and H2(H2O)2 three-body potentials. The database for H2(H2O) consists of approximately 44 000 energies at the coupled cluster singles and doubles plus perturbative triples (CCSD(T))-F12a/haQZ (aug-cc-pVQZ for O and cc-pVQZ for H) level of theory, while the database for the three-body interaction consists of more than 36 000 energies at the CCSD(T)-F12a/haTZ (aug-cc-pVTZ for O, cc-pVTZ for H) level of theory. Two precise potentials are based on the invariant-polynomial technique and are compared to computationally faster ones obtained via “purified” symmetrization. All fits use reduced permutational symmetry appropriate for these non-covalent interactions. These intrinsic potentials are employed together with existing ones for H2, H2O, and (H2O)2, to obtain full PESs for H2(H2O) and H2(H2O)2. Properties of these full PESs are presented, including a diffusion Monte Carlo calculation of the zero-point energy and wavefunction, and dissociation energy of the H2(H2O) dimer. These PESs together with an existing one for water clusters are used in a many-body representation of the PES of hydrogen clathrate hydrates, illustrated for H2@(H2O)20. An analysis of this hydrate is presented, including the electronic dissociation energy to remove H2 from the calculated equilibrium structure

  15. 1H, 1H, 2H, 2H-Perfluoroalkyl-Functionalization of Ni(II), Pd(II) and Pt(II) Mono- and Diphosphine Complexes : minimizing the Electronic Consequences for the Metal Center

    Koten, G. van; Wolf, E. de; Mens, A.J.M.; Gijzeman, O.L.J.; Lenthe, J.H. van; Jenneskens, L.W.; Deelman, B.J.

    2003-01-01

    A series of fluorous derivatives of group 10 complexes MCl2(dppe) and [M(dppe)2](BF4)2 (M = Ni, Pd or Pt; dppe = 1,2-bis(diphenylphosphino)ethane) and cis-PtCl2(PPh3)2 was synthesized. The influence of para-(1H,1H,2H,2H-perfluoroalkyl)dimethylsilyl-functionalization of the phosphine phenyl groups of

  16. Full-dimensional, high-level ab initio potential energy surfaces for H2(H2O) and H2(H2O)2 with application to hydrogen clathrate hydrates.

    Homayoon, Zahra; Conte, Riccardo; Qu, Chen; Bowman, Joel M

    2015-08-28

    New, full-dimensional potential energy surfaces (PESs), obtained using precise least-squares fitting of high-level electronic energy databases, are reported for intrinsic H2(H2O) two-body and H2(H2O)2 three-body potentials. The database for H2(H2O) consists of approximately 44 000 energies at the coupled cluster singles and doubles plus perturbative triples (CCSD(T))-F12a/haQZ (aug-cc-pVQZ for O and cc-pVQZ for H) level of theory, while the database for the three-body interaction consists of more than 36 000 energies at the CCSD(T)-F12a/haTZ (aug-cc-pVTZ for O, cc-pVTZ for H) level of theory. Two precise potentials are based on the invariant-polynomial technique and are compared to computationally faster ones obtained via "purified" symmetrization. All fits use reduced permutational symmetry appropriate for these non-covalent interactions. These intrinsic potentials are employed together with existing ones for H2, H2O, and (H2O)2, to obtain full PESs for H2(H2O) and H2(H2O)2. Properties of these full PESs are presented, including a diffusion Monte Carlo calculation of the zero-point energy and wavefunction, and dissociation energy of the H2(H2O) dimer. These PESs together with an existing one for water clusters are used in a many-body representation of the PES of hydrogen clathrate hydrates, illustrated for H2@(H2O)20. An analysis of this hydrate is presented, including the electronic dissociation energy to remove H2 from the calculated equilibrium structure. PMID:26328838

  17. Studies in synthetic carbonatite systems: Solidus relationships for CaO-MgO-CO_2-H_2O to 40 kbar and CaO-MgO-SiO_2-CO_2-H_2O to 10 kbar

    Boettcher, A. L.; Robertson, J. K.; Wyllie, P. J.

    1980-01-01

    The system CaO-MgO-SiO_2-CO_2-H_2O is an important model for many igneous and metamorphic processes, including the generation and differentiation of carbonatite and associated silicate magmas. We have experimentally established the vapor-saturated solidus for the system CaO-MgO-CO_2-H_2O from 595°C/1 kbar to

  18. A FORMAÇÃO DE LIGAÇÕES DE HIDROGÊNIO π‧‧‧H, F‧‧‧H E C‧‧‧H NOS COMPLEXOS C2H2‧‧‧(HF, C2H2‧‧‧2(HF E C2H2‧‧‧3(HF

    Boaz G. Oliveira

    2016-04-01

    Full Text Available In this work, a theoretical study on the basis of structural, vibrational, electronic and topological parameters of the C2H2‧‧‧(HF, C2H2‧‧‧2(HF and C2H2‧‧‧3(HF complexes concerning the formation of π‧‧‧H, F‧‧‧H and C‧‧‧H hydrogen bonds is presented. The main difference among these complexes is not properly the interaction strength, but the hydrogen bond type whose benchmark is ruled justly by the structure. Meanwhile, the occurrence of π‧‧‧H hydrogen bonds was unveiled in both C2H2‧‧‧(HF dimer and C2H2‧‧‧3(HF tetramer, although in latter, this interaction is stronger than C‧‧‧H of the C2H2‧‧‧2(HF trimer. However, the F‧‧‧H hydrogen bonds within the subunits of hydrofluoric acid are the strongest ones, reaching a partial covalent limit, and thereby contribute decisively to the stabilization of the tetramer structure. In line with this, the largest red-shifts were observed on the hydrofluoric acid trimer of the C2H2‧‧‧3(HF complex.

  19. Hydrocarbon transport in the laboratory plasma (MAP)

    Matsuyama, Seiji; Yamaguchi, Kenji; Yamawaki, Michio [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Tanaka, Satoru

    1996-10-01

    Hydrocarbons are admitted in the laboratory plasma in order to investigate the transport processes of carbon - containing molecules in relation to redeposition processes in the fusion boundary plasma. When CH{sub 4} was introduced into the plasma, CH radical band spectra were optically identified, while in the case of C{sub 2}H{sub 2} introduction, C{sub 2} radicals were also identified in addition to CH radicals. Excitation temperature was determined from CH and C{sub 2} spectra band, which was observed to increase on approaching to the target. (author)

  20. Biosynthese und Metabolismus von 2,5-Dimethyl-4-hydroxy-3(2H)-furanon in Erdbeeren

    Wein, Martina

    2002-01-01

    Die vorliegende Arbeit präsentiert neue Erkenntnisse zur Biosynthese von 2,5-Dimethyl-4-hydroxy-3(2H)-furanon (DMHF) und 2,5-Dimethyl-4-methoxy-3(2H)-furanon (DMMF), zwei wichtigen Aromakomponenten in Erdbeeren. Potentielle, mit stabilen Isotopen markierte Vorläufersubstanzen wurden an Erdbeeren appliziert und drei Tage bei Raumtemperatur inkubiert. Der Nachweis über den erfolgreichen Einbau erfolgte mittels Gaschromatographie-Massenspektrometrie. Anhand der Massenspektren von DMHF und DMMF, ...

  1. Total photoabsorption cross sections for 1H, 2H and 3He from 200 to 800 MeV

    The total photoabsorption cross sections for 1H, 2H and 3He have been measured for incident photon energies ranging from 200 to 800 MeV. The results show clearly the changes in the nucleon resonances in going from 1H to 3He. In particular, for the D13 region the behaviour for 3He is intermediate between that for 1H, 2H and heavier nuclei. (author)

  2. Effect of metformin therapy on 2-h post-glucose insulin levels in patients of polycystic ovarian syndrome

    Pikee Saxena; Anupam Prakash; Aruna Nigam

    2010-01-01

    Aims : To evaluate if 2-h post glucose insulin level is an effective tool to monitor insulin resistance in response to metformin therapy, in infertile women with polycystic ovarian syndrome (PCOS). Settings and Design : This prospective observational study was carried out in a tertiary care infertility clinic. Materials and Methods : 40 women with PCOS were categorized as having insulin resistance if fasting or 2-h post glucose insulin levels were >25 or >41μU/ml respectively. Post glucose in...

  3. 1,3,5-trinitroso- and 1,3,5-trinitrohexahydro-1,3,5-triazine-2H6

    Perdeuteration of 1,3,5-trinitrosohexahydro-1,3,5-triazine was brought about by treatment with potassium alkoxide in CH3O2H(99.5%). The important high energy compound, 1,3,5-trinitrohexahydro-1,3,5-triazine (RDX), was obtained in its perdeuterated modification (>99% 2H) by oxidation of the perdeuterated trinitrosamine with a mixture of nitric acid (100%) and hydrogen peroxide (30%). (author)

  4. Palladium-catalyzed coupling of N-tosylhydrazones and β-bromostyrene derivatives: new approach to 2H-chromenes.

    Xia, Yamu; Xia, Ying; Zhang, Yan; Wang, Jianbo

    2014-12-14

    2H-Chromene is an important structural motif that exists in natural products and non-natural compounds possessing interesting biological activities. In this investigation, a highly efficient approach toward 2H-chromenes has been developed based on palladium-catalyzed coupling of N-tosylhydrazones and β-bromostyrenes. The mechanism of this reaction is proposed that involves the formation of vinyl palladium by carbene migratory insertion and the intramolecular nucleophilic substitution. PMID:25327448

  5. Plasma waves

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  6. Plasma astrophysics

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  7. Synthesis of 4-Triazolylamino- and 4-Benzothiazolylamino-3-nitro-2H-[1]-Benzopyran-2-ones and their Antimicrobial Activity

    Ramiz Hoti

    2014-10-01

    Full Text Available Novel substituted benzopyran-2-one derivatives were synthesized by catalytic condensation reactions under reflux conditions. 4-(1,2,4-Triazolyl-3-amino-3-nitro-2H-[1]-benzopyran-2-ones 4(a-b were synthesized by condensation of 4-chloro-3-nitro-2H-[1]-benzopyran-2-one (2 and corresponding 3-aminotriazoles 3(a-b. 4-(4’-methoxy-2-benzothiazolylamino-3-nitro-2H-[1]-benzopyran-2-one (4c, 4-(6’-nitro-2-benzothiazolylamino-3-nitro-2H-[1]-benzopyiran-2-one (4d and 4-(6’-fluoro-2-benzothiazolylamino-3-nitro-2H-[1]-benzopyran-2-one (4e were synthesized by condensation of 4-chloro-3-nitro-2H-[1]-benzopyran-2-one (2 and corresponding 2-aminobenzothiazole 3(c-e under reflux reaction conditions. Further, alkali hydrolysis of 4(a-e afforded the 2-hydroxy-ω-nitroacetophenone (5. Antimicrobial activity of products 4(a-e against S. aurous, E. coli and Klebsiella were investigated measuring of inhibition zones around the discs which are marked with DMF, concentration 2 mg/mL, 4 mg/mL and 6 mg/mL solutions. Compounds 4c, 4e and 4d were more active against S. aureus. Emphatic activity against E. coli exhibited compounds 4b and 4e, whereas 4c and 4d were more active against Klebsiella.

  8. Ligand-induced substrate steering and reshaping of [Ag2(H)](+) scaffold for selective CO2 extrusion from formic acid.

    Zavras, Athanasios; Khairallah, George N; Krstić, Marjan; Girod, Marion; Daly, Steven; Antoine, Rodolphe; Maitre, Philippe; Mulder, Roger J; Alexander, Stefanie-Ann; Bonačić-Koutecký, Vlasta; Dugourd, Philippe; O'Hair, Richard A J

    2016-01-01

    Metalloenzymes preorganize the reaction environment to steer substrate(s) along the required reaction coordinate. Here, we show that phosphine ligands selectively facilitate protonation of binuclear silver hydride cations, [LAg2(H)](+) by optimizing the geometry of the active site. This is a key step in the selective, catalysed extrusion of carbon dioxide from formic acid, HO2CH, with important applications (for example, hydrogen storage). Gas-phase ion-molecule reactions, collision-induced dissociation (CID), infrared and ultraviolet action spectroscopy and computational chemistry link structure to reactivity and mechanism. [Ag2(H)](+) and [Ph3PAg2(H)](+) react with formic acid yielding Lewis adducts, while [(Ph3P)2Ag2(H)](+) is unreactive. Using bis(diphenylphosphino)methane (dppm) reshapes the geometry of the binuclear Ag2(H)(+) scaffold, triggering reactivity towards formic acid, to produce [dppmAg2(O2CH)](+) and H2. Decarboxylation of [dppmAg2(O2CH)](+) via CID regenerates [dppmAg2(H)](+). These gas-phase insights inspired variable temperature NMR studies that show CO2 and H2 production at 70 °C from solutions containing dppm, AgBF4, NaO2CH and HO2CH. PMID:27265868

  9. The effects of maternal anxiety during pregnancy on IGF2/H19 methylation in cord blood

    Mansell, T; Novakovic, B; Meyer, B; Rzehak, P; Vuillermin, P; Ponsonby, A-L; Collier, F; Burgner, D; Saffery, R; Ryan, J; Vuillermin, Peter; Ponsonby, Anne-Louise; Carlin, John B; Allen, Katie J; Tang, Mimi L; Saffery, Richard; Ranganathan, Sarath; Burgner, David; Dwyer, Terry; Jachno, Kim; Sly, Peter

    2016-01-01

    Compelling evidence suggests that maternal mental health in pregnancy can influence fetal development. The imprinted genes, insulin-like growth factor 2 (IGF2) and H19, are involved in fetal growth and each is regulated by DNA methylation. This study aimed to determine the association between maternal mental well-being during pregnancy and differentially methylated regions (DMRs) of IGF2 (DMR0) and the IGF2/H19 imprinting control region (ICR) in newborn offspring. Maternal depression, anxiety and perceived stress were assessed at 28 weeks of pregnancy in the Barwon Infant Study (n=576). DNA methylation was measured in purified cord blood mononuclear cells using the Sequenom MassArray Platform. Maternal anxiety was associated with a decrease in average ICR methylation (Δ=−2.23% 95% CI=−3.68 to −0.77%), and across all six of the individual CpG units in anxious compared with non-anxious groups. Birth weight and sex modified the association between prenatal anxiety and infant methylation. When stratified into lower (⩽3530 g) and higher (>3530 g) birth weight groups using the median birth weight, there was a stronger association between anxiety and ICR methylation in the lower birth weight group (Δ=−3.89% 95% CI=−6.06 to −1.72%), with no association in the higher birth weight group. When stratified by infant sex, there was a stronger association in female infants (Δ=−3.70% 95% CI=−5.90 to −1.51%) and no association in males. All the linear regression models were adjusted for maternal age, smoking and folate intake. These findings show that maternal anxiety in pregnancy is associated with decreased IGF2/H19 ICR DNA methylation in progeny at birth, particularly in female, low birth weight neonates. ICR methylation may help link poor maternal mental health and adverse birth outcomes, but further investigation is needed. PMID:27023171

  10. Hydrochemistry and 18O/16O and 2H/1H Ratios of Ugandan Waters

    Gebremichael, M. G.; Jasechko, S.

    2013-12-01

    Today, 70% of the 35 million people living in Uganda have access to an improved water source, ranking Uganda 148 out of 179 nations reporting in 2010 (Millennium Development Goals Indicators). 80% of Ugandans rely on groundwater as their primary drinking water source, collecting at springs or from shallow wells. Similarly, 80% of Ugandans rely upon agriculture - usually rain fed - as their primary income source. Despite lack of access to protected water sources faced by 10 million Ugandans, and the importance of the blue economy to Uganda's continued development, a country-wide investigation of the chemistry and the stable oxygen and hydrogen isotope compositions of waters has yet to be completed. Here we present 250 analyses of 18O/16O, 2H/1H and dissolved ion concentrations of Ugandan lakes, rivers, groundwaters and springs collected during July, 2013. We use the new data to characterize regional scale groundwater recharge sources, advection pathways and interactions with surface waters. Large lakes - Albert, Edward and Victoria - show increases in 18O/16O and 2H/1H ratios consistent with open water evaporation, and are shown to be distinct from nearby groundwaters, suggesting minimal recharge from large lakes to the subsurface. Salinities of eastern Ugandan groundwaters are elevated relative to samples collected from the central and western regions, suggesting that longer groundwater residence times and enhanced water-rock interactions characterize these waters. Springs from western Uganda show a shift in 18O/16O to higher values as a result of hydrothermal water-rock exchanges. Dissolved ion and noble gas concentrations show potential for use in assessing geothermal energy resources, perhaps aiding the Ugandan Ministry for Energy, Minerals and Development to meet their goal of increasing renewable energy from 4% (current) to 61% of total use by 2017 (Nyakabwa-Atwoki, 2013). Millennium Development Goals Indicators. mdgs.un.org/unsd/mdg/data.aspx Nyakabwa

  11. CO2 and C2H2 in cold nanodroplets of oxygenated organic molecules and water

    Devlin, J. Paul; Balcı, F. Mine; Maşlakcı, Zafer; Uras-Aytemiz, Nevin

    2014-11-01

    Recent demonstrations of subsecond and microsecond timescales for formation of clathrate hydrate nanocrystals hint at future methods of control of environmental and industrial gases such as CO2 and methane. Combined results from cold-chamber and supersonic-nozzle [A. S. Bhabhe, "Experimental study of condensation and freezing in a supersonic nozzle," Ph.D. thesis (Ohio State University, 2012), Chap. 7] experiments indicate extremely rapid encagement of components of all-vapor pre-mixtures. The extreme rates are derived from (a) the all-vapor premixing of the gas-hydrate components and (b) catalytic activity of certain oxygenated organic large-cage guests. Premixing presents no obvious barrier to large-scale conditions of formation. Further, from sequential efforts of the groups of Trout and Buch, a credible defect-based model of the catalysis mechanism exists for guidance. Since the catalyst-generated defects are both mobile and abundant, it is often unnecessary for a high percentage of the cages to be occupied by a molecular catalyst. Droplets represent the liquid phase that bridges the premixed vapor and clathrate hydrate phases but few data exist for the droplets themselves. Here we describe a focused computational and FTIR spectroscopic effort to characterize the aerosol droplets of the all-vapor cold-chamber methodology. Computational data for CO2 and C2H2, hetero-dimerized with each of the organic catalysts and water, closely match spectroscopic redshift patterns in both magnitude and direction. Though vibrational frequency shifts are an order of magnitude greater for the acetylene stretch mode, both CO2 and C2H2 experience redshift values that increase from that for an 80% water-methanol solvent through the solvent series to approximately doubled values for tetrahydrofuran and trimethylene oxide (TMO) droplets. The TMO solvent properties extend to a 50 mol.% solution of CO2, more than an order of magnitude greater than for the water-methanol solvent mixture

  12. Methionine kinetics in adult men: effects of dietary betaine on L-[2H3-methyl-1-13C]methionine

    The effects of a daily 3-g supplement of betaine on kinetic aspects of L-[2H3-methyl-1-13C]methionine (MET) metabolism in healthy young adult men were explored. Four groups of four subjects each were given a control diet, based on an L-amino acid mixture supplying 29.5 and 21.9 mg.kg-1.d-1 of L-methionine and L-cystine for 4 d before the tracer study, conducted on day 5 during the fed state. Two groups received the control diet and two groups received the betaine supplement. Tracer was given intravenously (iv) or orally. The transmethylation rate of MET (TM), homocysteine remethylation (RM), and oxidation of methionine were estimated from plasma methionine labeling and 13C enrichment of expired air. RM tended to increase (P = 0.14) but the TM and methionine oxidation were significantly (P less than 0.05) higher after betaine supplementation when estimated with the oral tracer. No differences were detected with the intravenous tracer. Methionine concentration in plasma obtained from blood taken from subjects in the fed state was higher (P less than 0.01) with betaine supplementation. These results suggest that excess methyl-group intake may increase the dietary requirement for methionine

  13. Magnetic properties of Cr-CrH and YFe2-YFe2H4

    Modifications of the electronic and magnetic properties of Cr and YFe2 due to hydrogen absorption were studied using band structure calculations with the LMTO-ASA method. For chromium, we show that the presence of hydrogen leads to a disappearance of antiferromagnetism. The paramagnetic state is the stable state of the hexagonal hydride CrH, in agreement with experimental results. We analyzed the role of the structural modifications and volume expansion of the Cr lattice and also the role of hydrogen on the electronic and magnetic properties. The increase of the density of states at the Fermi level from Cr to CrH is in agreement with measurements of heat capacity and magnetic susceptibility. The stronger magnetization in ferromagnetic YFe2H4 compared to YFe2 was explained by two antagonistic effects: (i) the lattice expansion due to hydrogen insertion which increases the magnetic moments MS at the Fe sites (ii) the metal-hydrogen interaction which slightly reduces MS. In the hydride, the majority spin states of Fe are fully filled and the Fermi energy falls in a peak of the minority spin density of states. We found a small ferrimagnetic coupling of the 4d states of yttrium. Our results are in satisfactory agreement with experimental magnetic data

  14. The H2O2-H2O Hypothesis: Extremophiles Adapted to Conditions on Mars?

    Houtkooper, Joop M.; Schulze-Makuch, Dirk

    2007-08-01

    The discovery of extremophiles on Earth is a sequence of discoveries of life in environments where it had been deemed impossible a few decades ago. The next frontier may be the Martian surface environment: could life have adapted to this harsh environment? What we learned from terrestrial extremophiles is that life adapts to every available niche where energy, liquid water and organic materials are available so that in principle metabolism and propagation are possible. A feasible adaptation mechanism to the Martian surface environment would be the incorporation of a high concentration of hydrogen peroxide in the intracellular fluid of organisms. The H2O2-H2O hypothesis suggests the existence of Martian organisms that have a mixture of H2O2 and H2O instead of salty water as their intracellular liquid (Houtkooper and Schulze-Makuch, 2007). The advantages are that the freezing point is low (the eutectic freezes at 56.5°C) and that the mixture is hygroscopic. This would enable the organisms to scavenge water from the atmosphere or from the adsorbed layers of water molecules on mineral grains, with H2O2 being also a source of oxygen. Moreover, below its freezing point the H2O2-H2O mixture has the tendency to supercool. Hydrogen peroxide is not unknown to biochemistry on Earth. There are organisms for which H2O2 plays a significant role: the bombardier beetle, Brachinus crepitans, produces a 25% H2O2 solution and, when attacked by a predator, mixes it with a fluid containing hydroquinone and a catalyst, which produces an audible steam explosion and noxious fumes. Another example is Acetobacter peroxidans, which uses H2O2 in its metabolism. H2O2 plays various other roles, such as the mediation of physiological responses such as cell proliferation, differentiation, and migration. Moreover, most eukaryotic cells contain an organelle, the peroxisome, which mediates the reactions involving H2O2. Therefore it is feasible that in the course of evolution, water-based organisms

  15. Energetic 128I reactions in Cdl2 - H2O system

    Energetic 128I reactions in gaseous and liquid phase are studied extensively by conventional retention measurements. Also a few charge plate collection experiments in liquid phase are performed. However, hot iodine atom reaction studies in water at N.T.P. by charge plate collection experiments are not reported so far. The present effort is an attempt to study the reactions of energetic 128I atoms originating from neutron bombardment of cadmium iodide in water. It is hoped that a relatively high thermal neutron capture cross section of iodine and convenient half life of 128I enable us to study favorably the high energy chemistry following 127I(n,γ)128I reaction in water. Present results are new and are critically discussed with the existing views, theories and mechanisms. It is concluded from the present investigation that the reactions of energetic iodine species in CdI2-H2O system is essentially governed by the reactivity of medium principally with the formation of reaction intermediates and/or complexes through collapsing the original molecular environment

  16. Near threshold angular distributions of the $^2$H$(\\gamma,\\Lambda)$X reaction

    Beckford, B; Chiba, A; Doi, D; Fujii, T; Fujii, Y; Futatsukawa, K; Gogami, T; Hashimoto, O; Honda, R; Hosomi, K; Kanda, H; Kaneta, M; Kaneko, Y; Kato, S; Kawama, D; Kimura, C; Kiyokawa, S; Koike, T; Maeda, K; Makabe, K; Matsubara, M; Miwa, K; Nagao, S; Nakamura, S N; Okuyama, A; Shirotori, K; Sugihara, K; Tamura, H; Tsukada, K; Yagi, K; Yamamoto, F; Yamamoto, T O; Han, Y C; Hirose, K; Ishikawa, T; Suzuki, K; Tamae, T; Yamazaki, H

    2013-01-01

    A study of the $^2$H$({\\gamma},{\\Lambda})$X reaction was performed using a tagged photon beam at the Research Center for Electron Photon Science (ELPH), Tohoku University. The photoproduced $\\Lambda$ was measured in the $p{\\pi^{-}}$ decay channel by the upgraded Neutral Kaon Spectrometer (NKS2+). The momentum integrated differential cross section was determined as a function of the scatting angle of ${\\Lambda}$ in the laboratory frame for five energy bins. Our results indicated a peak in the cross section at angles smaller than cos$\\theta^{LAB}_{\\Lambda}$ = 0.95. The experimentally obtained angular distributions were compared to isobar models, Kaon-Maid (KM) and Saclay-Lyon A (SLA), in addition to the composite Regge-plus-resonance (RPR) model. Both SLA(r$K_{1}K_{\\gamma}$ = -1.4) and RPR describe the tendency of the data quite well in contrast to the KM model that substantially under predicted the cross section. With the anticipated forthcoming data on ${\\Lambda}$ integrated and momentum dependent differentia...

  17. 2,3,5-Triphenyl-2H-tetrazol-3-ium iodide

    Hoong-Kun Fun

    2012-09-01

    Full Text Available The asymmetric unit of the title molecular salt, C19H15N4+·I−, contains four 2,3,5-triphenyl-2H-tetrazol-3-ium cations and five iodide anions, with two of the latter lying on crystallographic inversion centres. In each cation, the tetrazole ring is essentially planar (r.m.s. deviations = 0.004–0.007 Å. The dihedral angles between the tetrazole ring and its three attached benzene rings in the four independent cations are: 12.9 (4, 67.0 (4, 48.1 (4; 20.8 (4, 51.1 (4, 62.3 (4; 11.4 (4, 52.3 (4, 47.3 (4 and 6.0 (4, 85.7 (4, 43.5 (4°. A C—H...I hydrogen bond and C—H...π interactions are observed in the crystal.

  18. Laser-induced nuclear motions in the Coulomb explosion of C2H2+ ions

    The laser-induced multifragmentation of C2H2 into protons and multicharged carbon ions is shown to be a direct instantaneous explosion of the molecule. The evolution of the overall nuclear structure is studied through ion-ion correlation peak shapes. The ratios of the maxima of the kinetic-energy release distributions to the Coulomb repulsion energies calculated at the equilibrium internuclear distances are measured to be 45% for the protons and 53% for the CZ+ ions for all the detected H++CZ'++CZ+ +H+ fragmentation channels. The time scale for electronic polarization and stripping compared with the intramolecular electronic and nuclear time evolutions does not allow using a frozen molecular ion structure for the description of the explosion, thus explaining in part the observed fragmentation pattern. During the laser-induced alignment and subsequent stabilization of the molecular frame around the laser polarization direction, the carbon-carbon axis undergoes small damped oscillations that remain larger than the corresponding oscillations of the hydrogen-hydrogen axis. This difference comes from the lower moment of inertia of the hydrogen atoms compared with that of the carbon atoms in the molecule. However, the subsequent deviation from the initial linear structure remains small and is observed when the molecular ion is not completely aligned along the laser electric field

  19. Structure and ferroelectric properties of ( C3 N2 H5 )5 Bi2 Cl11

    Jakubas, R.; Piecha, A.; Pietraszko, A.; Bator, G.

    2005-09-01

    Pentakis (imidazolium) undecachlorodibismuthate(III), (C3N2H5)5Bi2Cl11 , has been synthesized and studied by means of the x-ray, differential scanning calorimetry (DSC), and dielectric methods over a wide temperature range. The room temperature crystal structure has been determined as monoclinic, space group P21/n with a=13.616Å , b=14.684Å , c=9.045Å , and β=96.85° . Two solid-solid phase transitions: P4¯n2→360KP21/n (I→II) , and P21/n→166KP21 (II→III) , discontinuous and continuous in nature, respectively, have been revealed. The dielectric and pyroelectric measurements allow us to characterize the lowest temperature phase (III) as ferroelectric with the Curie point at 166K and saturated spontaneous polarization value of the order of 6×10-3Cm-2 along the b axis. The ferroelectric phase transition mechanism is governed by the dynamics of imidazolium cations. The room temperature, paraelectric phase (II) demonstrates additionally the ferroelastic properties.

  20. Supramolecular order and structural dynamics: A STM study of 2H-tetraphenylporphycene on Cu(111)

    The adsorption of 2H-tetraphenylporphycene (2HTPPc) on Cu(111) was investigated by scanning tunneling microscopy (STM). At medium coverages, supramolecular ordered islands are observed. The individual 2HTPPc molecules appear as two pairs of intense protrusions which are separated by an elongated depression. In the islands, the molecules are organized in rows oriented along one of the close packed Cu(111) substrate rows; the structure is stabilized by T-type interactions of the phenyl substituents of neighboring molecules. Two types of rows are observed, namely, highly ordered rows in which all molecules exhibit the same orientation, and less ordered rows in which the molecules exhibit two perpendicular orientations. Altogether, three different azimuthal orientations of 2HTPPc are observed within one domain, all of them rotated by 15° ± 1° relative to one closed packed Cu direction. The highly ordered rows are always separated by either one or two less ordered rows, with the latter structure being the thermodynamically more stable one. The situation in the islands is highly dynamic, such that molecules in the less ordered rows occasionally change orientation, also complete highly ordered rows can move. The supramolecular order and structural dynamics are discussed on the basis of the specific molecule-substrate and molecule-molecule interactions

  1. Supramolecular order and structural dynamics: A STM study of 2H-tetraphenylporphycene on Cu(111).

    Stark, Michael; Träg, Johannes; Ditze, Stefanie; Brenner, Wolfgang; Jux, Norbert; Steinrück, Hans-Peter; Marbach, Hubertus

    2015-03-14

    The adsorption of 2H-tetraphenylporphycene (2HTPPc) on Cu(111) was investigated by scanning tunneling microscopy (STM). At medium coverages, supramolecular ordered islands are observed. The individual 2HTPPc molecules appear as two pairs of intense protrusions which are separated by an elongated depression. In the islands, the molecules are organized in rows oriented along one of the close packed Cu(111) substrate rows; the structure is stabilized by T-type interactions of the phenyl substituents of neighboring molecules. Two types of rows are observed, namely, highly ordered rows in which all molecules exhibit the same orientation, and less ordered rows in which the molecules exhibit two perpendicular orientations. Altogether, three different azimuthal orientations of 2HTPPc are observed within one domain, all of them rotated by 15° ± 1° relative to one closed packed Cu direction. The highly ordered rows are always separated by either one or two less ordered rows, with the latter structure being the thermodynamically more stable one. The situation in the islands is highly dynamic, such that molecules in the less ordered rows occasionally change orientation, also complete highly ordered rows can move. The supramolecular order and structural dynamics are discussed on the basis of the specific molecule-substrate and molecule-molecule interactions. PMID:25770514

  2. Isomerization, Perturbations, Calculations and the S_{1} State of C_{2}H_{2}

    Baraban, J. H.; Changala, P. B.; Berk, J. R. P.; Field, R. W.; Stanton, J. F.; Merer, A. J.

    2013-06-01

    Preliminary analysis of the energy region of the cis-trans isomerization transition state on the S_{1} surface of C_{2}H_{2} has revealed novel patterns and surprising perturbations, including unusually large (and high-order) anharmonicities, as well as K-staggerings of several vibrational levels. These effects complicate the analysis considerably, and require new models and calculations to account for and predict features of the observed spectra. The ˜{A}-˜{X} spectrum of acetylene has been studied both experimentally and theoretically for almost a century, and this cycle of unexpected phenomena eliciting innovative responses is found throughout its history. Especially in the last ten years, progress in understanding the S_{1} state rovibrational level structure and cis-trans isomerization has been accelerated by combining the information available from both ab initio computation and spectroscopic observations. The resulting dialogue has then frequently suggested fruitful avenues for further experiments and calculations. Current challenges and recent results in understanding the cis-trans isomerization transition state region will be discussed in this context.

  3. Supramolecular order and structural dynamics: A STM study of 2H-tetraphenylporphycene on Cu(111)

    Stark, Michael; Träg, Johannes; Ditze, Stefanie; Steinrück, Hans-Peter; Marbach, Hubertus, E-mail: hubertus.marbach@fau.de [Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen (Germany); Interdisciplinary Center for Molecular Materials (ICMM), Universität Erlangen-Nürnberg, Henkestr. 42, 91054 Erlangen (Germany); Brenner, Wolfgang; Jux, Norbert [Lehrstuhl für Organische Chemie II, Universität Erlangen-Nürnberg, Henkestr. 42, 91054 Erlangen (Germany)

    2015-03-14

    The adsorption of 2H-tetraphenylporphycene (2HTPPc) on Cu(111) was investigated by scanning tunneling microscopy (STM). At medium coverages, supramolecular ordered islands are observed. The individual 2HTPPc molecules appear as two pairs of intense protrusions which are separated by an elongated depression. In the islands, the molecules are organized in rows oriented along one of the close packed Cu(111) substrate rows; the structure is stabilized by T-type interactions of the phenyl substituents of neighboring molecules. Two types of rows are observed, namely, highly ordered rows in which all molecules exhibit the same orientation, and less ordered rows in which the molecules exhibit two perpendicular orientations. Altogether, three different azimuthal orientations of 2HTPPc are observed within one domain, all of them rotated by 15° ± 1° relative to one closed packed Cu direction. The highly ordered rows are always separated by either one or two less ordered rows, with the latter structure being the thermodynamically more stable one. The situation in the islands is highly dynamic, such that molecules in the less ordered rows occasionally change orientation, also complete highly ordered rows can move. The supramolecular order and structural dynamics are discussed on the basis of the specific molecule-substrate and molecule-molecule interactions.

  4. Crystal and magnetic structures of 2H BaMnO{sub 3}

    Cussen, E.J.; Battle, P.D.

    2000-03-01

    The crystal structure of the 2H perovskite BaMnO{sub 3} has been refined from neutron powder diffraction data collected at room temperature and 80 and 1.7 K. The structure consists of chains of face-sharing MnO{sub 6} octahedra, separated by Ba{sup 2+} cations. At room temperature, a = 5.6991(2), c = 4.8148(2) {angstrom}, space group P6{sub 3}/mmc. At 80 K, a = 9.8467(1), c = 4.8075(1) {angstrom}, space group P6{sub 3}cm. The structural phase transition introduces a displacement of neighboring chains and reduces the coordination number of Ba{sup 2+}. Long-range antiferromagnetic ordering is apparent below T{sub N} = 59(2) K, with a magnetic moment of 1.31(5) {micro}{sub B} per Mn{sup 4+} cation at 1.7 K. Neighboring spins within each chain are antiferromagnetically coupled and lie in a plane perpendicular to [001]. The spin directions associated with the chains at (1/3, 2/3, z ) and (2/3, 1/3, z) are rotated by {+-} 120 {degree} with respect to that of the chain at (0, 0, z)

  5. Stability and mobility of screw dislocations in 4H, 2H and 3C silicon carbide

    Large-scale first-principles calculations were performed to determine the stability and mobility properties of screw dislocations in common silicon carbide polytypes (4H, 2H and 3C). There is a profound lack of knowledge regarding these dislocations, although experimental observations show that they govern the plastic behavior of SiC at low temperature. Numerical simulations reported in this paper indicate that these dislocations are characterized by a shuffle core, the associated Peierls stress of which ranges from 8.9 to 9.6 GPa depending on the polytype. The only other stable dislocation core exhibits a reconstruction along the dislocation line, with a greater stability, but is also found to be sessile. Polytypism has a weak influence on these results, especially regarding dislocation core energies and Peierls stress. However, a qualitative difference is predicted between the cubic and the hexagonal systems regarding slip planes, with a possible dislocation displacement along a prismatic plane on average, which would result from a zigzag motion of the screw dislocations at the atomic scale

  6. Influence of 2p-2h configurations on beta-decay rates

    Severyukhin, A P; Borzov, I N; Arsenyev, N N; Van Giai, Nguyen

    2014-01-01

    The effects of the phonon-phonon coupling on the beta-decay rates of neutron-rich nuclei are studied in a microscopic model based on Skyrme-type interactions. The approach uses a finite-rank separable approximation of the Skyrme-type particle-hole (p-h) residual interaction. Very large two-quasiparticle spaces can thus be treated. A redistribution of the Gamow-Teller (G-T) strength is found due to the tensor correlations and the 2p-2h fragmentation of G-T states. As a result, the beta-decay half-lives are decreased significantly. Using the Skyrme interaction SGII together with a volume-type pairing interaction we illustrate this reduction effect by comparing with available experimental data for the Ni isotopes and neutron-rich N=50 isotones. We give predictions for 76Fe and 80Ni in comparison with the case of the doubly-magic nucleus 78Ni which is an important waiting point in the r-process.

  7. Removal of Boron in Silicon by H2-H2O Gas Mixtures

    Tang, Kai; Andersson, Stefan; Nordstrand, Erlend; Tangstad, Merete

    2012-08-01

    The removal of boron in pure silicon by gas mixtures has been examined in the laboratory. Water-vapor-saturated hydrogen was used to remove boron doped in electronic-grade silicon in a vacuum frequency furnace. Boron concentrations in silicon were reduced from 52 ppm initially to 0.7 ppm and 3.4 ppm at 1450°C and 1500°C, respectively, after blowing a H2-3.2%H2O gas mixture for 180 min. The experimental results indicate that the boron removal as a function of gas-blowing time follows the law of exponential decay. After 99% of the boron is removed, approximately 90% of the silicon can be recovered. In order to better understand the gaseous refining mechanism, the quantum chemical coupled cluster with single and double excitations and a perturbative treatment of triple excitations method was used to accurately predict the enthalpy and entropy of formation of the HBO molecule. A simple refining model was then used to describe the boron refining process. This model can be used to optimize the refining efficiency.

  8. Theory of muon spin relaxation of gaseous C2H4Mu

    A theoretical study of the muon spin relaxation of the gaseous muonated ethyl radical C2H4Mu is expanded in this paper to include both longitudinal and transverse signals. This study is based upon an operator expansion of the spin-density operator for the radical with its time dependence described by the linearized quantum Boltzmann equation. Relaxation is due to collisions which reorient the radical close-quote s rotational angular momentum while effects on the muon close-quote s spin are due to couplings between the muon close-quote s spin, the radical close-quote s free-electron spin, and the radical close-quote s rotational angular momentum. The coefficients of the radical close-quote s spin Hamiltonian and the collisional lifetimes (cross sections) are used as fitting parameters to describe the transverse signals. A fit to the transverse data by itself and a global fit to both the transverse and longitudinal data are obtained with good accuracy. copyright 1996 The American Physical Society

  9. Mesostructured tin oxide as sensitive material for C(2)H(5)OH sensor.

    Wang, Yu-De; Ma, Chun-Lai; Wu, Xing-Hui; Sun, Xiao-Dan; Li, Heng-De

    2002-07-01

    Mesostructured tin oxide with high specific surface area was synthesized using cationic surfactant (cetyltrimethylammonium bromide, CTAB: CH(3)(CH(2))(15)N(+)(CH(3))(3)Br(-)) as the organic template and hydrous tin chloride (SnCl(4).5H(2)O) and NH(4)OH as the inorganic precursors under acidic conditions at ambient temperature. Thermogravimetric analysis (TGA), Fourier transformed infrared (FTIR), X-ray diffraction analysis (XRD), X-ray photoelectron spectrum (XPS) and N(2)-sorption isotherms were used to characterize the mesostructured tin oxide that was formed at room temperature as well as calcined at different temperature. The surface area of mesostructured tin oxide calcined at 400 degrees C is 136 m(2) g(-1). The indirect heating sensor using this material as sensitive body was fabricated on an alumna tube with Au electrodes and platinum wires. Electrical and sensing properties of such a sensor were investigated. It was found that the mesostructured tin oxide with high surface area had higher sensitivity to C(2)H(5)OH and selectivity to gasoline than commercial sample of polycrystalline tin(IV) oxide. PMID:18968691

  10. Protein 2D NMR analysis utilizing selective 2H and 13C enrichment

    E. coli thioredoxin has been prepared with specific residue types substituted with fully enriched 2H or 13C labeled amino acids. In 1H COSY and NOESY experiments cross peaks result from pairs of protons interacting via through-bond or through-space coupling respectively. A cross peak is eliminated if either nucleus is substituted with deuterium. Direct residue type assignments of cross peaks have been obtained by comparing data from protein samples with one residue type deuterated and data from a non-enriched sample. Selective deuteration is particularly useful for the interresidue connectivity assignments obtained by NOESY experiments which normally depend on residue type assignment information obtained from independent COSY data. Difficulties in 1H COSY type intraresidue connectivity assignments are the main reason that successful analyses generally have been limited to proteins less than 10 kilodaltons. The authors have collected 13C homonuclear COSY data which compared to the 1H experiment benefit from larger spin couplings as well as from the spectral simplification obtained by enrichment. Resolved cross peaks for the 13C-13C J1 couplings are readily observed with 30 mg of labeled protein. 1H-13C heteronuclear COSY experiments then provide an independent method of intraresidue proton spin connectivity assignments

  11. 2H(p,γ)3He reaction using polarized and unpolarized protons

    The 900 yield curve for the 2H(p,γ) 3He reaction has been studied over the excitation region in 3He of approximately 7 to 15 MeV. Both polarized and unpolarized proton beams were used to measure the angular distributions of cross section and analyzing power at E/sub x/ = 8.83, 9.83, and 10.83 MeV. If only the four non-spin-flip E1 and E2 T-matrix elements are considered, their amplitudes and relative phases can be extracted. The E2 cross section obtained from this analysis is found to be (12 +- 5) % of the total cross section. The detailed balanced differential (theta/sub lab/ = 900) and total cross sections at E/sub x/ = 10.83 MeV are found to be (117 +- 11) μb/sr and (1.07 +- 0.11) mb, respectively; the quoted errors represent the total uncertainties in the cross sections obtained in this experiment. The results are also compared with recent E1 and E2 calculations

  12. Applications of stable isotopes of 2H, 13C and 15N to clinical problems

    The function of the Argonne Program is to provide synthetic, analytical instrumental capability in a core facility for the clinical investigator who needs to use 2H, 13C, or 15N labelled compounds for metabolic or clinical research on pregnant women, newborn infants, young children, or for mass screening. To carry out such application development, there were six stages which were recurrent steps in every application. Five fundamental strategies should be adopted to establish the use of stable isotopes in clinical work. The instrument required for measurements was a combined gas chromatograph-mass spectrometer, and its use was schematically illustrated. Some of the successful experiences with compounds labelled by stable isotopes, such as deuterium labelled chenodeoxycholic acid, and respective 13C and 15N-labelled glycine were described. Deutrium labelled bile acid enabled easy and safe determination of the size of the bile acid pool and the replacement rate, providing clearer diagnoses for cholestatic liver disease and gallstones. 13C and 15N labelled compounds were used in clinical studies, of children with genetic disorders of amino acid metabolism, i.e., non ketotic hyperflycinemia, B12-responsive methyl malonic acidemia, and Lesch-Nyhan syndrome. 15N-labelled glycine was also studied in a child with Lesch-Nyhan syndrome. (Mukohata, S.)

  13. Synthesis, structure and NMR characterization of a new monomeric aluminophosphate [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4 containing four different types of monophosphates

    Chen, Peng; Li, Jiyang; Xu, Jun; Duan, Fangzheng; Deng, Feng; Xu, Ruren

    2009-03-01

    A new zero-dimensional (0D) aluminophosphate monomer [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4 (designated AlPO-CJ38) with Al/P ratio of 1/6 has been solvothermally prepared by using racemic cobalt complex dl-Co(en) 3Cl 3 as the template. The Al atom is octahedrally linked to six P atoms via bridging oxygen atoms, forming a unique [Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2] 6- monomer. Notably, there exists intramolecular symmetrical O⋯H⋯O bonds, which results in pseudo-4-rings stabilized by the strong H-bonding interactions. The structure is also featured by the existence of four different types of monophosphates that have been confirmed by 31P NMR and 1H NMR spectra. The crystal data are as follows: AlPO-CJ38, [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4, M = 1476.33, monoclinic, C2/ c (No. 15), a = 36.028(7) Å, b = 8.9877(18) Å, c = 16.006(3) Å, β = 100.68(3)°, U = 5093.2(18) Å 3,Z = 4, R1 = 0.0509 ( I > 2 σ( I)) and wR2 = 0.1074 (all data). CCDC number 689491.

  14. DNA methylation of the IGF2/H19 imprinting control region and adiposity distribution in young adults

    Huang Rae-Chi

    2012-11-01

    Full Text Available Abstract Background The insulin-like growth factor 2 (IGF2 and H19 imprinted genes control growth and body composition. Adverse in-utero environments have been associated with obesity-related diseases and linked with altered DNA methylation at the IGF2/H19 locus. Postnatally, methylation at the IGF2/H19 imprinting control region (ICR has been linked with cerebellum weight. We aimed to investigate whether decreased IGF2/H19 ICR methylation is associated with decreased birth and childhood anthropometry and increased contemporaneous adiposity. DNA methylation in peripheral blood (n = 315 at 17 years old was measured at 12 cytosine-phosphate-guanine sites (CpGs, analysed as Sequenom MassARRAY EpiTYPER units within the IGF2/H19 ICR. Birth size, childhood head circumference (HC at six time-points and anthropometry at age 17 years were measured. DNA methylation was investigated for its association with anthropometry using linear regression. Results The principal component of IGF2/H19 ICR DNA methylation (representing mean methylation across all CpG units positively correlated with skin fold thickness (at four CpG units (P-values between 0.04 to 0.001 and subcutaneous adiposity (P = 0.023 at age 17, but not with weight, height, BMI, waist circumference or visceral adiposity. IGF2/H19 methylation did not associate with birth weight, length or HC, but CpG unit 13 to 14 methylation was negatively associated with HC between 1 and 10 years. β-coefficients of four out of five remaining CpG units also estimated lower methylation with increasing childhood HC. Conclusions As greater IGF2/H19 methylation was associated with greater subcutaneous fat measures, but not overall, visceral or central adiposity, we hypothesize that obesogenic pressures in youth result in excess fat being preferentially stored in peripheral fat depots via the IGF2/H19 domain. Secondly, as IGF2/H19 methylation was not associated with birth size but negatively with early childhood HC, we

  15. A versatile entry into aqueous niobium chemistry: isolation and structure of the intermediate Nb4(mu2-O)2(mu2-OC2H5)4Cl2(OC2H5)4(HOC2H5)4

    Ooi, Bee Lean; Søtofte, Inger

    2004-01-01

    The reduction of ethanolic solutions of niobium pentachloride with zinc, followed by treatment with aqueous acids serves as a versatile entry into the aqueous solution chemistry of niobium. From the zinc-reduced solution, the major intermediate, Nb4(mu2-O)2(mu2-OC2H5)4Cl4(OC2H5)4(HOC2H5)4, was...... isolated and the crystal structure determined by X-ray crystallography. The complex crystallizes in the orthorhombic space group Pccn, with Z = 4, a = 21.0105(9), b = 11.0387(5), c = 19.1389(8), V = 4438.9(3) Å3, Mr = 1090.19, R1 = 0.0327 and wR2 = 0.0876. The structure revealed a centro......¬symmetric tetrameric Nb(IV) complex, consisting of a pair of edge-sharing bi-octahedral Nb2(mu2-OC2H5)4Cl2(OC2H5)2(HOC2H5)2 units that are joined by two axial oxo ligands. The Nb-Nb distance of 2.7458(3) Å is consistent with a single metal-metal bond....

  16. N2H4·H2O水热体系ZnO微晶的结晶特性%ZnO microcrystal growth in hydrothermal processing with N2H4·H2O

    刘长友; 谷智; 王涛; 查钢强; 介万奇

    2011-01-01

    研究了低浓度(0.01~0.20mol/L)N2H4.H2O条件下ZnO微晶的低温水热结晶特性。N2H4.H2O弱碱性和N2H5+吸附配位性影响ZnO微晶的形核和各晶面的生长速率。随着N2H4.H2O浓度的提高,ZnO微晶分别呈板条状、六角片状和六角棒束状。碱性分散剂和超声的分散作用影响主要在成核阶段;受分散剂弱碱性的影响,0.20mol/L N2H4.H2O显现出强的还原性,N2气泡模板生长机制使所制ZnO微晶呈六角管状晶须束。%ZnO microcrystal growth was investigated under a low temperature hydrothermal process with a relatively low concentration of N2H4·H2O(0.01-0.20mol/L).The nucleation and the growth rates of various crystal planes are strongly affected by the weak alkalinity of N2H4·H2O and the co-ordinative activity of N2H+5 ion.ZnO microcrystals change from oatmeal-like plate to hexagonal plate,and then to hexagonal rod-like cluster with increasing of N2H4·H2O concentrations,respectively.The nucleations of ZnO microcrystals are influenced by the alkaline dispersant and ultrasonic treatment.The solution of 0.20mol/L N2H4·H2O with the alkaline dispersant has a strong reducibility,which changes the mechanism of nucleation and growth of ZnO microcrystals.The center-hollow hexagonal rod-like ZnO clusters were obtained through the N2 bubble template-growth route.

  17. 2H-1-苯并吡喃衍生物的合成及其体外抗癌活性的初步评价%Synthesis and initially anticancer activity evaluation of novel 2 H-1-benzopyran derivatives

    聂爱华; 顾为; 王勇俊; 黄子为

    2008-01-01

    Aim To design and synthesize novel 2H-1-benzopyran derivatives and to evaluate their anticancer activity.Methods 2'-Hydroxychalcones were transferred to flavones derivatives under microwave irradiation.The flavones derivatives were reacted with POCl3 to get 4-chloro-2H-chromene-3-carbaldehydes.Novel 2H-1-benzopyran derivatives were prepared by the reaction of various 4-chloro-2H-chromene-3-carbaldehydes with R3CONHNH2 under microwave irradiation combining solution phase parallel synthesis.HL-60 cell line was employed to evaluate anticancer activity of these compounds in vitro.Results and conclusion A combinatorial library containing 32 novel 2H-1-benzopyran derivatives was synthesized.Some of these compounds exhibited inhibitory activity against HL-60 cell proliferation.The inhibitory rate of compound 9e was 70.8% at the concentration of 30 μmol·L-1.%目的 设计并合成2H-1-苯并吡喃衍生物化合库并对其体外抗癌活性进行评价.方法 以2'-羟基查耳酮为原料通过微波促进合成得到黄酮衍生物中间体,此中间体与POC13反应得到4-氯-2H-色原烯-3-醛,通过微波辅助液相平行合成的方法.此醛与R3CONHNH2反应得到2H-1-苯并吡喃衍生物化合库.利用HL-60细胞系评价该化合物库的体外抗癌活性.结果 与结论合成了含有32个化合物的2H-1-苯并吡喃衍生物库,体外活性评价表明,部分化合物对HL-60细胞的增殖有一定的抑制作用,其中,化合物9e在浓度为30μmol·L-1的抑制率为70.8%.

  18. Plasma device

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  19. ECR plasma assisted nitridation of high speed steel

    Conventional industrial nitridation techniques for tool steel include DC plasma and gas phase reactions. Nitridation by Electron Cyclotron Resonance plasma (ECR) of N2 + H2 has yielded higher case depth of nitrided layer on tool steel in lower time as compared to Industrial nitridation. This is mainly due to the higher energies as well as densities of ions in ECR plasma. The substrates were mounted on a heater held in the upstream of the N2 + H2 plasma zone. The heater and correspondingly the samples were heated for temperatures 450 deg and 550 deg. during plasma treatment. A negative bias of -300 V with respect to the chamber was given to the sample. The samples were treated for a time of 90 minutes

  20. Simulation of nanoparticle coagulation in radio-frequency C2H2/Ar microdischarges

    Xiang-Mei, Liu; Qi-Nan, Li; Rui, Li

    2016-06-01

    The nanoparticle coagulation is investigated by using a couple of fluid models and aerosol dynamics model in argon with a 5% molecular acetylene admixture rf microdischarges, with the total input gas flow rate of 400 sccm. It co-exists with a homogeneous, secondary electron-dominated low temperature γ-mode glow discharges. The heat transfer equation and flow equation for neutral gas are taken into account. We mainly focused on investigations of the nanoparticle properties in atmospheric pressure microdischarges, and discussed the influences of pressure, electrode spacing, and applied voltage on the plasma density and nanoparticle density profiles. The results show that the characteristics of microdischarges are quite different from those of low pressure radio-frequency discharges. First, the nanoparticle density in the bulk plasma in microdischarges is much larger than that of low pressure discharges. Second, the nanoparticle density of 10 nm experiences an exponential increase as soon as the applied voltage increases, especially in the presheath. Finally, as the electrode spacing increases, the nanoparticle density decreased instead of increasing. Project supported by the Natural Science Foundation of Heilongjiang Province, China (Grant Nos. A2015011 and A2015010), the Postdoctoral Scientific Research Development Fund of Heilongjiang Province, China (Grant No. LBH-Q14159), the Program for Young Teachers Scientific Research in Qiqihar University (Grant No. 2014k-Z11), the National Natural Science Foundation of China (Grant No. 11404180), and the University Nursing Program for Yong Scholars with Creative Talents in Heilongjiang Province, China (Grant No. UNPYSCT-2015095).

  1. Pharmacokinetic equivalence of 5(ethyl(/sup 2/H)5)- and unlabelled phenobarbitone

    Benchekroun, Y.; Ribon, B.; Falconnet, J.B.; Cherrah, Y.; Brazier, J.L.

    1989-02-01

    The present study shows the absence of in vivo pharmacokinetic isotope effect on phenobarbitone (PB) C5-ethyl deuteration (PBd5) following oral administration to man of equimolar PB/PBd5 mixtures (0.40 mmol each). Plasma PB and PBd5 (17 days) and urine PB, PBd5 and parahydroxy-metabolites (PBOH, PBHOd5) levels were determined by GC-MS. Isotope effect research includes comparison of pharmacokinetic parameters, study of time-dependence of isotope ratios (IRs) in plasma and urine (linearity test), comparison of IRs between samples and administered mixtures (Mann Whitney's test) and comparison of PBOH/PBOHd5 ratios before and after urine enzymatic hydrolysis (Student's two tailed t-test). No significant isotope effect was observed on pharmacokinetic parameters, PB hydroxylation or PBOH conjugation (x less than or equal to 5%); which the absence of pentadeuteration-induced alteration in PB's HSA binding parameters (binding mode, Ka, N) corroborates (x less than or equal to 5%). These results establish bioequivalence of PB and PBd5; the latter can be used with benefit in stable-isotope clinical pharmacology (steady state pharmacokinetics, drug interactions...) investigations as well as bioavailability studies of PB preparations.

  2. Pharmacokinetic equivalence of 5(ethyl(2H)5)- and unlabelled phenobarbitone

    The present study shows the absence of in vivo pharmacokinetic isotope effect on phenobarbitone (PB) C5-ethyl deuteration (PBd5) following oral administration to man of equimolar PB/PBd5 mixtures (0.40 mmol each). Plasma PB and PBd5 (17 days) and urine PB, PBd5 and parahydroxy-metabolites (PBOH, PBHOd5) levels were determined by GC-MS. Isotope effect research includes comparison of pharmacokinetic parameters, study of time-dependence of isotope ratios (IRs) in plasma and urine (linearity test), comparison of IRs between samples and administered mixtures (Mann Whitney's test) and comparison of PBOH/PBOHd5 ratios before and after urine enzymatic hydrolysis (Student's two tailed t-test). No significant isotope effect was observed on pharmacokinetic parameters, PB hydroxylation or PBOH conjugation (x less than or equal to 5%); which the absence of pentadeuteration-induced alteration in PB's HSA binding parameters (binding mode, Ka, N) corroborates (x less than or equal to 5%). These results establish bioequivalence of PB and PBd5; the latter can be used with benefit in stable-isotope clinical pharmacology (steady state pharmacokinetics, drug interactions...) investigations as well as bioavailability studies of PB preparations

  3. Plasma antennas

    Anderson, Theodore

    2011-01-01

    The plasma antenna is an emerging technology that partially or fully utilizes ionized gas as the conducting medium instead of metal to create an antenna. The key advantages of plasma antennas are that they are highly reconfigurable and can be turned on and off. The disadvantage is that the plasma antennas require energy to be ionized. This unique resource provides you with a solid understanding of the efficient design and prototype development of plasma antennas, helping you to meet the challenge of reducing the power required to ionize the gas at various plasma densities. You also find thorou

  4. Radiation heterogeneous processes in the system nano-ZrO2+H2O

    Full text : In this paper, in order to determine the influence of zirconia on the radiolysis of water there were investigated the kinetics of accumulation of molecular hydrogen at the radiolytic decomposition of water in the system ZrO2 + H2O at T = 300 K. On the basis of the kinetic curves there was determined value of the process rate and radiation - chemical yield of molecular hydrogen G(H2) calculated for the energy of the absorbed water. In the operation of nuclear reactors construction materials (ZrO2) are simultaneously exposed to the influence of temperature and radiation in contact with the coolant. In this paper, in order to identify regularities of radiation, radiation-thermal processes in contact of coolant with the nanopowder of ZrO2, which is the material of nuclear reactors with water cooling there were studied the kinetics of accumulation of molecular hydrogen under the influence of gamma - radiation at different temperatures. Zirconium dioxide (ZrO2) is one of the materials, which are widely used in science and technology. ZrO2 is used in the manufacture of nuclear reactor fuel cells that convert chemical energy into electrical energy. Fuel cell devices operating at high temperatures. The use of zirconia for fuel cells due to the high ionic conductivity, which is due to the transfer of the oxygen anion vacancies. In order to ensure their high quality there are use nanoscale powders. Nanoscale systems are very different from conventional single-crystal systems. Therefore, the study of their properties under the influence of gamma - radiation is of practical and scientific interest

  5. Water interactions with varying molecular states of bovine casein: 2H NMR relaxation studies

    The caseins occur in milk as spherical colloidal complexes of protein and salts with an average diameter of 1200 A, the casein micelles. Removal of Ca2+ is thought to result in their dissociation into smaller protein complexes stabilized by hydrophobic interactions and called submicelles. Whether these submicelles actually occur within the micelles as discrete particles interconnected by calcium phosphate salt bridges has been the subject of much controversy. A variety of physical measurements have shown that casein micelles contain an inordinately high amount of trapped water (2 to 7 g H2O/g protein). With this in mind it was of interest to determine if NMR relaxation measurements could detect the presence of this trapped water within the micelles, and to evaluate whether it is a continuum with picosecond correlation times or is associated in part with discrete submicellar structures with nanosecond motions. For this purpose the variations in 2H NMR longitudinal and transverse relaxation rates of water with protein concentration were determined for bovine casein at various temperatures, under both submicellar and micellar conditions. D2O was used instead of H2O to eliminate cross-relaxation effects. From the protein concentration dependence of the relaxation rates, the second virial coefficient of the protein was obtained by nonlinear regression analysis. Using either an isotropic tumbling or an intermediate asymmetry model, degrees of hydration, v, and correlation times, tau c, were calculated for the caseins; from the latter parameter the Stokes radius, r, was obtained. Next, estimates of molecular weights were obtained from r and the partial specific volume. Values were in the range of those published from other methodologies for the submicelles

  6. Synthesis and antifungal activity of 2H-1,4-benzoxazin-3(4H)-one derivatives.

    Śmist, Małgorzata; Kwiecień, Halina; Krawczyk, Maria

    2016-06-01

    A series of 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l) was easily synthesized by two-step process involving O-alkylation of 2-nitrophenols with methyl 2-bromoalkanoates and next "green" catalytic reductive cyclization of the obtained 2-nitro ester intermediates (3a-l). Further, 6,7-dibromo (5a-c) and N-acetyl (6) derivatives were prepared by bromination and acetylation of unsubstituted 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-c). The novel compounds (3a-l, 4d-l, 5a-c and 6) were fully characterized by spectroscopic methods (MS, (1)H and (13)C NMR). 2-Alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l, 5a-c and 6) were screened for antifungal activity. Preliminary assays were performed using two methods: in vitro against seven phytopathogenic fungi-Botrytis cinerea, Phythophtora cactorum, Rhizoctonia solani, Phoma betae, Fusarium culmorum, Fusarium oxysporum and Alternaria alternata-and in vivo against barley powdery mildew Blumeria graminis. The tested compounds displayed moderate to good antifungal activity at high concentration (200 mg L(-1)). The most potent compounds were 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a), 2-ethyl-7-fluoro-2H-1,4-benzoxazin-3(4H)-one (4g) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6), which completely inhibited the mycelial growth of seven agricultural fungi at the concentration of 200 mg L(-1) in the in vitro tests. Moreover, 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6) were also screened for antifungal activity at concentrations of 100 mg L(-1) and 20 mg L(-1). In the concentration of 100 mg L(-1), the N-acetyl derivative (6) completely inhibited the growth of three strains of fungi (F. culmorum, P. cactorum and R. solani), while 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) completely inhibited only R. solani strain. At the concentration of 20 mg L(-1), compound 6 showed good activity only against P. cactorum strain (72%). PMID:26963527

  7. Upper limit for the D2H+ ortho-to-para ratio in the prestellar core 16293E (CHESS)

    Vastel, C; Ceccarelli, C; Bacmann, A; Lis, D C; Pagani, L; Caux, E; Codella, C; Beckwith, J A; Ridley, T

    2012-01-01

    The H3+ ion plays a key role in the chemistry of dense interstellar gas clouds where stars and planets are forming. The low temperatures and high extinctions of such clouds make direct observations of H3+ impossible, but lead to large abundances of H2D+ and D2H+, which are very useful probes of the early stages of star and planet formation. The ground-state rotational ortho-D2H+ 111-000 transition at 1476.6 GHz in the prestellar core 16293E has been searched for with the Herschel/HIFI instrument, within the CHESS (Chemical HErschel Surveys of Star forming regions) Key Program. The line has not been detected at the 21 mK km/s level (3 sigma integrated line intensity). We used the ortho-H2D+ 110-111 transition and para-D2H+ 110-101 transition detected in this source to determine an upper limit on the ortho-to-para D2H+ ratio as well as the para-D2H+/ortho-H2D+ ratio from a non-LTE analysis. The comparison between our chemical modeling and the observations suggests that the CO depletion must be high (larger than...

  8. Site-resolved (2)H relaxation experiments in solid materials by global line-shape analysis of MAS NMR spectra.

    Lindh, E L; Stilbs, P; Furó, I

    2016-07-01

    We investigate a way one can achieve good spectral resolution in (2)H MAS NMR experiments. The goal is to be able to distinguish between and study sites in various deuterated materials with small chemical shift dispersion. We show that the (2)H MAS NMR spectra recorded during a spin-relaxation experiment are amenable to spectral decomposition because of the different evolution of spectral components during the relaxation delay. We verify that the results are robust by global least-square fitting of the spectral series both under the assumption of specific line shapes and without such assumptions (COmponent-REsolved spectroscopy, CORE). In addition, we investigate the reliability of the developed protocol by analyzing spectra simulated with different combinations of spectral parameters. The performance is demonstrated in a model material of deuterated poly(methacrylic acid) that contains two (2)H spin populations with similar chemical shifts but different quadrupole splittings. In (2)H-exchanged cellulose containing two (2)H spin populations with very similar chemical shifts and quadrupole splittings, the method provides new site-selective information about the molecular dynamics. PMID:27152833

  9. Charge density wave and superconductivity in 2H- and 4H-NbSe2: A revisit

    I Naik; A K Rastogi

    2011-06-01

    Good-quality hexagonal NbSe2 single crystals were prepared. In 2H-NbSe2, superconducting and charge density wave (CDW) transitions were found at = 7.4 K and = 35 K respectively as reported previously. We have noticed that these two transitions are changed to = 42 K and = 6.5 K, in 4H-NbSe2. Thermopower has shown clear anomaly at CDW transitions. The anisotropic upper critical field was calculated as ∼ 3 and 6.3 for 2H- and 4H-single crystals around = 0.81, where = /, from resistivity and explained in terms of coherence length. From the relation, $H_{c2}() = H_{c2}(0)[1 − ^2]$, $H^l_{c2}(0)$ was calculated as ∼ 8.15 T and 16.98 T at = 0.84 in 2H-NbSe2 and 4H-NbSe2 respectively. However, $H^_{c2}(0) = 2.68$ T for both single crystals.

  10. Grasping hydrogen adsorption and dynamics in metal-organic frameworks using (2)H solid-state NMR.

    Lucier, Bryan E G; Zhang, Yue; Lee, Kelly J; Lu, Yuanjun; Huang, Yining

    2016-06-18

    Record greenhouse gas emissions have spurred the search for clean energy sources such as hydrogen (H2) fuel cells. Metal-organic frameworks (MOFs) are promising H2 adsorption and storage media, but knowledge of H2 dynamics and adsorption strengths in these materials is lacking. Variable-temperature (VT) (2)H solid-state NMR (SSNMR) experiments targeting (2)H2 gas (i.e., D2) shed light on D2 adsorption and dynamics within six representative MOFs: UiO-66, M-MOF-74 (M = Zn, Mg, Ni), and α-M3(COOH)6 (M = Mg, Zn). D2 binding is relatively strong in Mg-MOF-74, Ni-MOF-74, α-Mg3(COOH)6, and α-Zn3(COOH)6, giving rise to broad (2)H SSNMR powder patterns. In contrast, D2 adsorption is weaker in UiO-66 and Zn-MOF-74, as evidenced by the narrow (2)H resonances that correspond to rapid reorientation of the D2 molecules. Employing (2)H SSNMR experiments in this fashion holds great promise for the correlation of MOF structural features and functional groups/metal centers to H2 dynamics and host-guest interactions. PMID:27181834

  11. Chemical study of intermediate-mass (IM) Class 0 protostars. CO depletion and N2H+ deuteration

    Alonso-Albi, T; Crimier, N; Caselli, P; Ceccarelli, C; Johnstone, D; Planesas, P; Rizzo, J R; Wyrowski, F; Tafalla, M; Lefloch, B; Maret, S; Dominik, C

    2010-01-01

    We are carrying out a physical and chemical study of the protostellar envelopes in a representative sample of IM Class 0 protostars. In our first paper (Crimier et al. 2010), we determined the physical structure (Density-Temperature radial profiles) of the protostellar envelopes. Here, we study the CO depletion and N2H+ deuteration. We observed the millimeter lines of C18O, C17O, N2H+ and N2D+ toward the protostars using the IRAM 30m telescope. Based on these observations, we derived the C18O, N2H+ and N2D+ radial abundance profiles across their envelopes using a radiative transfer code. In addition, we modeled the chemistry of the protostellar envelopes. All the C18O 1-0 maps are well fit assuming that the C18O abundance decreases inwards within the protostellar envelope until the gas and dust reach the CO evaporation temperature, 20-25K, where the CO is released back to the gas phase. The N2H+ deuterium fractionation in Class 0 IMs is [N2D+]/[N2H+]=0.005-0.014, two orders of magnitude larger than the elemen...

  12. Synergistic WO3·2H2O Nanoplates/WS2 Hybrid Catalysts for High-Efficiency Hydrogen Evolution.

    Yang, Lun; Zhu, Xiaobin; Xiong, Shijie; Wu, Xinglong; Shan, Yun; Chu, Paul K

    2016-06-01

    Tungsten trioxide dihydrate (WO3·2H2O) nanoplates are prepared by in situ anodic oxidation of tungsten disulfide (WS2) film on carbon fiber paper (CFP). The WO3·2H2O/WS2 hybrid catalyst exhibits excellent synergistic effects which facilitate the kinetics of the hydrogen evolution reaction (HER). The electrochromatic effect takes place via hydrogen intercalation into WO3·2H2O. This process is accelerated by the desirable proton diffusion coefficient in the layered WO3·2H2O. Hydrogen spillover from WO3·2H2O to WS2 occurs via atomic polarization caused by the electric field of the charges on the planar defect or edge active sites of WS2. The optimized hybrid catalyst presents a geometrical current density of 100 mA cm(-2) at 152 mV overpotential with a Tafel slope of ∼54 mV per decade, making the materials one of the most active nonprecious metal HER catalysts. PMID:27211828

  13. Analyzing powers for 2H(d(vector sign),d)2H at deuteron energies of 3.0, 4.75, and 6.0 MeV

    Tensor analyzing powers for 2H(d(vector sign),d)2H elastic scattering were measured at deuteron energies of 3.0, 4.75, and 6.0 MeV. The measured values are below 0.02 and increase with increasing energy. The data were compared to the results of an R-matrix parametrization and microscopic four-body calculations. The calculations indicate that the nucleon-nucleon p waves have a strong effect on the observables. (c) 2000 The American Physical Society

  14. Thermodynamic parameters of MeO2+ + H+ reversible MeO22+ + 1/2 H2 reaction for americium and neptunium ions in solution of potassium phosphotungstates

    Formal oxidation potentials of MeO22+-MeO2+ pair are measured for americium and neptunium ions in solutions of potassium phosphotungstates in 23-51 deg C temperature range at solution pH values equal to 1.0 and 4.0 by differential coulopotentiometric and potentiometric methods. Based on the data obtained Gibbs energy change values; enthalpies and enthropies for MeO2+ + H+ ↔ MeO22+ + 1/2H2 reaction are calculated

  15. Nonisothermal Kinetice of Dehydration Process of [Sm(m-CIBA)3phen]2·2H2O and[Sm(p-CIBA)3phen]2·2H2O

    REN Ning; WANG Xie; ZHANG Jie; ZHANG Jian-jun; XU Su-ling; ZHANG Hai-yan

    2008-01-01

    Compounds[Sm(m-CIBA)3phen]2·2H2O and[Sm(p-ClBA)3phen]2·2H2O(m-ClBA=m-chlorobenzoate,PClBA=p-chlorobenzoate,phen=1,10-phenanthroline)were prepared.The dehydration processes and kinetics of these compounds were studied from the analysis of the DSC curves using a method of processing the data of thermal analysis kinetics.The Arrhenius equation for the dehydration process can be expressed as lnk=38.65-243.90x103|RT for and△S≠ of dehydration reaction for the title compounds are determined,respectively.

  16. Full-dimensional, high-level ab initio potential energy surfaces for H{sub 2}(H{sub 2}O) and H{sub 2}(H{sub 2}O){sub 2} with application to hydrogen clathrate hydrates

    Homayoon, Zahra; Conte, Riccardo; Qu, Chen; Bowman, Joel M., E-mail: jmbowma@emory.edu [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

    2015-08-28

    New, full-dimensional potential energy surfaces (PESs), obtained using precise least-squares fitting of high-level electronic energy databases, are reported for intrinsic H{sub 2}(H{sub 2}O) two-body and H{sub 2}(H{sub 2}O){sub 2} three-body potentials. The database for H{sub 2}(H{sub 2}O) consists of approximately 44 000 energies at the coupled cluster singles and doubles plus perturbative triples (CCSD(T))-F12a/haQZ (aug-cc-pVQZ for O and cc-pVQZ for H) level of theory, while the database for the three-body interaction consists of more than 36 000 energies at the CCSD(T)-F12a/haTZ (aug-cc-pVTZ for O, cc-pVTZ for H) level of theory. Two precise potentials are based on the invariant-polynomial technique and are compared to computationally faster ones obtained via “purified” symmetrization. All fits use reduced permutational symmetry appropriate for these non-covalent interactions. These intrinsic potentials are employed together with existing ones for H{sub 2}, H{sub 2}O, and (H{sub 2}O){sub 2}, to obtain full PESs for H{sub 2}(H{sub 2}O) and H{sub 2}(H{sub 2}O){sub 2}. Properties of these full PESs are presented, including a diffusion Monte Carlo calculation of the zero-point energy and wavefunction, and dissociation energy of the H{sub 2}(H{sub 2}O) dimer. These PESs together with an existing one for water clusters are used in a many-body representation of the PES of hydrogen clathrate hydrates, illustrated for H{sub 2}@(H{sub 2}O){sub 20}. An analysis of this hydrate is presented, including the electronic dissociation energy to remove H{sub 2} from the calculated equilibrium structure.

  17. Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

    Qian, Ping; Du, Bingnan; Jiao, Wei; Mei, Haibo

    2016-01-01

    Summary An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C–C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields. Additionally, N-methacryloylbenzamides were also suitable substrates for the current reaction and provided the alkyl-substituted isoquinoline-1,3(2H,4H)-diones in good yield. PMID:26977189

  18. Plasma Modification of PCL Porous Scaffolds Fabricated by Solvent Casting/Particulate Leaching for Tissue Engineering

    Sardella, E.; Gristina, R; NARDULLI M.; Ceccone, Giacomo; Favia, P.; D'AGOSTINO R.

    2010-01-01

    This study points out how the plasma modification of PCL porous scaffolds, produced by Solvent Casting/Particulate Leaching, may enhance their biocompatibility. A C2H4/N2 plasma deposition followed by a H2 plasma treatment was used to increase the hydrophilicity of the whole scaffold to support osteoblast cell proliferation, both outside and inside the scaffold. A better cell growth was obtained on plasma modified scaffolds.

  19. Dehydrogenation of N{sub 2}H{sub X} (X = 2 − 4) by nitrogen atoms: Thermochemical and kinetics

    Spada, Rene Felipe Keidel; Araujo Ferrão, Luiz Fernando de [Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 12.228-900, São Paulo (Brazil); Departamento de Física, Instituto Tecnológico de Aeronáutica, São José dos Campos 12.228-900, São Paulo (Brazil); Roberto-Neto, Orlando [Divisão de Aerotermodinâmica e Hipersônica, Instituto de Estudos Avançados, São José dos Campos 12.229-840, São Paulo (Brazil); Machado, Francisco Bolivar Correto, E-mail: fmachado@ita.br [Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 12.228-900, São Paulo (Brazil)

    2013-11-21

    Thermochemical and kinetics of sequential hydrogen abstraction reactions from hydrazine by nitrogen atoms were studied. The dehydrogenation was divided in three steps, N{sub 2}H{sub 4} + N, N{sub 2}H{sub 3} + N, and N{sub 2}H{sub 2} + N. The thermal rate constants were calculated within the framework of canonical variational theory, with zero and small curvature multidimensional tunnelling corrections. The reaction paths were computed with the BB1K/aug-cc-pVTZ method and the thermochemical properties were improved with the CCSD(T)/CBS//BB1K/aug-cc-pVTZ approach. The first dehydrogenation step presents the lowest rate constants, equal to 1.22 × 10{sup −20} cm{sup 3} molecule{sup −1} s{sup −1} at 298 K.

  20. Synthesis of pteroylglutamic acid-3',5'-2H2 by trifluoroacetic acid catalyzed exchange with deuterium oxide

    Pteroylglutamic acid (PGA) was deuterated by trifluoroacetic acid catalyzed exchange with deuterium oxide. The product, pteroylglutamic acid-3',5'-2H2, was specifically deuterated in the aromatic protons of the p-aminobenzoyl (PABA) moiety; the protons on C7 and C9 and in the glutamic acid residue were not exchanged. Deuterium incorporation was measured by chemical ionization mass spectrometry (CI-MS). Pteroylglutamates were cleaved by a base-catalyzed, oxidative hydrolysis to PABA, which was converted to the methyl ester, N-trifluoroacetate for analysis by gas chromatography-chemical ionization-mass spectrometry. Products from the exchange typically contained 1 percent 2H1 and 90 percent 2H2 species. The procedure may be used to label specifically various analogs of PGA with deuterium in the PABA portion of the molecule

  1. Local structure and molecular motions in imidazolium hydrogen malonate crystal as studied by 2H and 13C NMR

    The local structure and molecular motion of the imidazolium hydrogen malonate crystal were investigated using solid-state 2H and 13C NMR. The imidazolium ion undergoes isotropic rotation, which is correlated with a defect in the crystal, as observed by 2H NMR broadline spectra above 263 K. A 180∘ flip of the imidazolium ion in the regular site was observed from 2H NMR quadrupole Carr-Purcell-Meiboom-Gill (QCPMG) spectra. The Grotthuss mechanism was accompanied by a 180∘ flip of the imidazolium ion in regular sites. Moreover, the proton transfer associated with the imidazolium ion of the defective crystal is important for proton conductivity of the imidazolium hydrogen malonate crystal

  2. Determination of relative natural isotopic abundance of 2H using NMR spectroscopy and application in food analysis

    The basic relations are defined for determining the content of deuterium in compound CXHP. Hydrogen atoms 1H and 2H are distributed among the individual diastereotopic points in the molecule which is either monodeuterized or non deuterized. The SNIF-NMR parameter is derived from these assumptions. Procedures are presented for preparing samples for NMR experiments. For measuring NMR spectra of 2H the effects are considered of relaxation times and the total time of measurement. Relaxation times of deuterium in small molecules are of the order of 1 second. The possibilities are shown of using 2H NMR spectroscopy for the study of deuterium transfer during chemical and biochemical reactions, for the determination of isotope purity, the determination of the origin of the sample and for the surveillance of technological processes. Examples of the applications are given. (E.S.). 3 figs., 8 tabs., 42 refs

  3. BROAD N{sub 2}H{sup +} EMISSION TOWARD THE PROTOSTELLAR SHOCK L1157-B1

    Codella, C.; Fontani, F.; Gómez-Ruiz, A.; Vasta, M. [INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Viti, S. [Department of Physics and Astronomy, University College London, London (United Kingdom); Ceccarelli, C.; Lefloch, B.; Podio, L. [UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Benedettini, M.; Busquet, G. [INAF, Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, 00133 Roma (Italy); Caselli, P., E-mail: codella@rcetri.astro.it [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2013-10-10

    We present the first detection of N{sub 2}H{sup +} toward a low-mass protostellar outflow, namely, the L1157-B1 shock, at ∼0.1 pc from the protostellar cocoon. The detection was obtained with the IRAM 30 m antenna. We observed emission at 93 GHz due to the J = 1-0 hyperfine lines. Analysis of this emission coupled with HIFI CHESS multiline CO observations leads to the conclusion that the observed N{sub 2}H{sup +}(1-0) line originated from the dense (≥10{sup 5} cm{sup –3}) gas associated with the large (20''-25'') cavities opened by the protostellar wind. We find an N{sub 2}H{sup +} column density of a few 10{sup 12} cm{sup –2} corresponding to an abundance of (2-8) × 10{sup –9}. The N{sub 2}H{sup +} abundance can be matched by a model of quiescent gas evolved for more than 10{sup 4} yr, i.e., for more than the shock kinematical age (≅2000 yr). Modeling of C-shocks confirms that the abundance of N{sub 2}H{sup +} is not increased by the passage of the shock. In summary, N{sub 2}H{sup +} is a fossil record of the pre-shock gas, formed when the density of the gas was around 10{sup 4} cm{sup –3}, and then further compressed and accelerated by the shock.

  4. H2CO AND N2H+ IN PROTOPLANETARY DISKS: EVIDENCE FOR A CO-ICE REGULATED CHEMISTRY

    We present Submillimeter Array (SMA) observations of H2CO and N2H+ emission in the disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296 at 2''-6'' resolution and discuss the distribution of these species with respect to CO freezeout. The H2CO and N2H+ emission toward HD 163296 does not peak at the continuum emission center that marks the stellar position but is instead significantly offset. Using a previously developed model for the physical structure of this disk, we show that the H2CO observations are reproduced if H2CO is present predominantly in the cold outer disk regions. A model where H2CO is present only beyond the CO snow line (estimated at a radius of 160 AU) matches the observations well. We also show that the average H2CO excitation temperature, calculated from two transitions of H2CO observed in these two disks and a larger sample of disks around T Tauri stars in the DISCS (the Disk Imaging Survey of Chemistry with SMA) program, is consistent with the CO freezeout temperature of ∼20 K. In addition, we show that N2H+ and H2CO line fluxes in disks are strongly correlated, indicative of co-formation of these species across the sample. Taken together, these results imply that H2CO and N2H+ are generally present in disks only at low temperatures where CO depletes onto grains, consistent with fast destruction of N2H+ by gas-phase CO, and in situ formation of H2CO through hydrogenation of CO ice. In this scenario H2CO, CH3OH, and N2H+ emission in disks should appear as rings with the inner edge at the CO midplane snow line. This prediction can be tested directly using observations from ALMA with higher resolution and better sensitivity.

  5. Fourth interlaboratory comparison exercise for δ2H and δ18O analysis of water samples (WICO2011)

    Complete text of publication follows. The IAEA Isotope Hydrology Laboratory organized the fourth interlaboratory comparison exercise for the analysis of hydrogen and oxygen stable isotope composition of water. Four water samples prepared and calibrated at the IAEA Isotope Hydrology Laboratory were labelled IAEA-OH-13 to IAEA-OH-16. Altogether 137 laboratories from 53 countries submitted 172 datasets to the IAEA. Samples cover the range of δ18O and δ2H values typical of natural waters. Each laboratory received four samples with a randomly assigned identification code. The reference values were calculated from the results of the 12 laboratories whose performance was the best in the last intercomparison exercise, WICO2002 (Table 1). Cumulative deviations for δ18O and δ2H are less than 0.2h and 2.0h, respectively. Statistical analysis of the submitted results was undertaken to assess the performance of each laboratory (precision and accuracy) with respect to the reference δ18O and δ2H values for the analysed four samples by a two-stage statistical treatment adopted in previous IAEA interlaboratory exercises. From our results (Table 2) it is generally seen that the mean values are within uncertainty the same as the reference values, however, our standard deviations are significantly higher. Fig. 1. shows the obtained value of each laboratory for the δ18O of the OH-16 sample and the δ2H value of the OH-14 sample, respectively. Our values are indicated by black arrows. The upper and the lower horizontal black lines show the 1σ deviation of the reference value (middle line). Fig. 2. shows the cumulative deviation of datasets from the reference values determined as 8 x δ18O + δ2H. According to these data, our dataset (black arrow) is the 25th best out of the 172 datasets of 153 laboratories in the world.

  6. Controls on compound specific 2H/1H of leaf waxes along a North American monsoonal transect

    Berke, M. A.; Tipple, B. J.; Hambach, B.; Ehleringer, J. R.

    2013-12-01

    The use of hydrogen isotope ratios of sedimentary n-alkanes from leaf waxes has become an important method for the reconstruction of paleohydrologic conditions. Ideally, the relationship between lipid 2H/1H values and source water is one-to-one. But the extent to which the 2H/1H values are altered between initial source water and lipid 2H/1H values varies by plant type and environment. Additionally, these variables may be confounded by use of varied source waters by plants in the same ecosystem. Here, we use a transect study across the arid southwestern landscape of the United States, which is heavily influenced by the North American Monsoon, to study the variability in 2H/1H values of leaf waxes in co-occurring plants from Tucson, Arizona to Salt Lake City, Utah. Perennials, including rabbit brush (Chrysothamnus nauseosus), sagebrush (Artemisia tridentata), and gambel oak (Quercus gambelii) and an annual plant, sunflower (Helianthus annuus), were chosen for their wide geographic distribution along the entire transect. Our results indicate that n-alkane distribution for each plant was similar and generally showed no relationship to environmental variables (elevation, mean annual precipitation, latitude, and temperature). However, we find evidence of n-alkane 2H/1H value relating to transect latitude, a relationship that is weaker for all samples combined than the strong individual correlation for each plant species. Further, these 2H/1H values suggest that not all plants in the monsoon region utilize monsoon-delivered precipitation. These results imply an adaptation to discontinuous spatial coverage and amount of monsoonal precipitation and suggest care must be taken when assuming consistent source water for different plants, particularly in regions with highly seasonal precipitation delivery.

  7. Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

    Palmer, Rachel K., E-mail: rachel.palmer@maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Hutchinson, Lee M.; Burpee, Benjamin T.; Tupper, Emily J.; Pelletier, Jonathan H.; Kormendy, Zsolt; Hopke, Alex R.; Malay, Ethan T.; Evans, Brieana L.; Velez, Alejandro [Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Gosse, Julie A., E-mail: julie.gosse@umit.maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States)

    2012-01-01

    Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clone 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast cells.

  8. Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

    Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clone 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast cells.

  9. Molecular orientation effect on the fragmentation of C2H4 in charge-changing collisions of carbon ions

    We report a role of molecular orientation in collision-induced fragmentation of C2H4 molecule under conditions of electron loss and capture collisions of C2+ ions at an energy of 857keV (v=1.69 a.u.). Coincidence measurements of fragment ions from C2H4 and charge-selected projectile ions were performed by means of a momentum three-dimensional imaging technique. The effect of molecular orientation is observed rather strongly in all the charge-changing collisions investigated. The experimental data are fitted to a newly developed formula which is often used to predict the orientation effect of diatomic molecules. (author)

  10. State-feedback H2/H-infinity controller design with D-stability constraints for stochastic systems

    Zhongwei LIN; Weihai ZHANG

    2007-01-01

    This paper addresses the state-feedback H2/H-infinity controller design that satisfies D-stability constraints for stochastic systems. Firstly, the concept of regional stability for stochastic systems is defined in linear matrix inequality(LMI) regions; Secondly, the characterization about stochastic D-stability is presented. This paper introduces a new technique to solve the regional stability problem for stochastic systems, which is different from the pole placement technique ever used in deterministic systems. Based on this, in the state-feedback case, mixed H2/H-infinity synthesis with D-stability constraints is discussed via LMI optimization.

  11. ARP: Automatic rapid processing for the generation of problem dependent SAS2H/ORIGEN-s cross section libraries

    Leal, L.C.; Hermann, O.W.; Bowman, S.M.; Parks, C.V.

    1998-04-01

    In this report, a methodology is described which serves as an alternative to the SAS2H path of the SCALE system to generate cross sections for point-depletion calculations with the ORIGEN-S code. ARP, Automatic Rapid Processing, is an algorithm that allows the generation of cross-section libraries suitable to the ORIGEN-S code by interpolation over pregenerated SAS2H libraries. The interpolations are carried out on the following variables: burnup, enrichment, and water density. The adequacy of the methodology is evaluated by comparing measured and computed spent fuel isotopic compositions for PWR and BWR systems.

  12. Optical properties of 1T and 2H phases of TaS2 and TaSe2

    Sangeeta Sharma; S Auluck; M A Khan

    2000-03-01

    We have calculated the anisotropic frequency dependent dielectric function for the 1T and 2H phases of TaS2 and TaSe2 using the linear muffin tin orbital method within the atomic sphere approximation. We find significant anisotropy in the frequency dependent dielectric function for the 1T and 2H phases at low energies (less than 4 eV). Unfortunately there are no experimental data to compare with. The averaged dielectric function agrees with the available experimental data except that the calculated peak heights are underestimated and shifted to higher energies by 1–2 eV.

  13. Updated evidences of the Trojan Horse particle invariance for $^2$H(d,p)$^3$H reaction

    Pizzone, R. G.; Spitaleri, C.(Dip. di Fisica e Astronomia, Univ. di Catania, via S. Sofia, Catania, Italy); Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L.; M. La Cognata; Lamia, L; Rinollo, A.; Spartá, R.; A. Tumino

    2012-01-01

    The Trojan Horse nucleus invariance for the binary d(d,p)t reaction was tested using the quasi free $^2$H($^6$Li, pt)$^4$He and $^2$H($^3$He,pt)H reactions after $^6$Li and $^3$He break-up, respectively. The astrophysical S(E)-factor for the d(d,p)t binary process was then extracted in the framework of the Plane Wave Approximation applied to the two different break-up schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good ag...

  14. A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H-furanones

    Jubi John

    2014-06-01

    Full Text Available A facile route towards highly functionalized 3(2H-furanones via a sequential Mannich addition–palladium catalyzed ring closing has been elaborated. The reaction of 4-chloroacetoacetate esters with imines derived from aliphatic and aromatic aldehydes under palladium catalysis afforded 4-substituted furanones in good to excellent yields. 4-Hydrazino-3(2H-furanones could also be synthesized from diazo esters in excellent yields by utilising the developed strategy. We could also efficiently transform the substituted furanones to aza-prostaglandin analogues.

  15. Constraints on Asian and European sources of methane from CH 4 -C 2 H 6 -CO correlations in Asian outflow

    Xiao, Yaping; Jacob, Daniel James; Wang, James; Logan, Jennifer A.; Palmer, Paul; Suntharalingam, Parvadha; Yantosca, Robert M.; Sachse, Glen; Blake, Donald; Streets, David

    2004-01-01

    Aircraft observations of Asian outflow from the Transport and Chemical Evolution Over the Pacific (TRACE-P) aircraft mission over the NW Pacific (March and April 2001) show large CH4 enhancements relative to background, as well as strong CH4-C2H6-CO correlations that provide signatures of regional sources. We apply a global chemical transport model simulation of the CH4-C2H6-CO system for the TRACE-P period to interpret these observations in terms of CH4 sources and to explore in particular t...

  16. Second-meal effects of pulses on blood glucose and subjective appetite following a standardized meal 2 h later.

    Mollard, Rebecca C; Wong, Christina L; Luhovyy, Bohdan L; Cho, France; Anderson, G Harvey

    2014-07-01

    This study investigated whether pulses (chickpeas, yellow peas, navy beans, lentils) have an effect on blood glucose (BG) and appetite following a fixed-size meal 2 h later. Over the following 2 h, all pulses lowered BG area under the curve (AUC) and lentils reduced appetite AUC compared with white bread (p < 0.05). Following the meal, BG was lower after lentils and chickpeas at 150 and 165 min, and AUC was lower after lentils compared with white bread (p < 0.05). PMID:24797207

  17. Automatic rapid process for the generation of problem-dependent SAS2H/ORIGEN-S cross-section libraries

    A methodology is described that serves as an alternative to the SAS2H path of the SCALE system to generate cross sections for point-depletion calculations with the ORIGEN-S code. Automatic Rapid Processing (ARP) is an algorithm that allows the generation of cross-section libraries suitable to the ORIGEN-S code by interpolation over pregenerated SAS2H libraries. The interpolations are carried out on the following variables: burnup, enrichment, and water density. The adequacy of the methodology is evaluated by comparing measured and computed spent-fuel isotopic compositions for pressurized water reactor and boiling water reactor systems

  18. Plasma physics

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  19. Plasma undulator

    Two types of the undulator which is developed as a generator of the highly brilliant light for the synchrotron radiation sources and the free electron lasers, are newly proposed using the array of slender plasmas columns. One is the magnetic field type, in which the undulator force on the relativistic electron beam is generated with the electric current flowing through the plasma columns. The other is the electric field type, in which the undulator force is generated with the periodic variation of the density between the slender plasma columns. The production methods and stabilization ones of plasma columns are discussed. (author)

  20. The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

    Hassan Ibrahim

    2006-12-31

    completed in June 2002 and the high Q^2 kinematics were completed in November 2002. Before the start of the experiment many preparations were made to assure the quality of the collected data. Approximately two Terabytes of data were collected by the end of the experiment. The cross section results in this dissertation show clearly the effect of final state interactions between the two final state nucleons. The cross section ratio to the Laget PWBA+FSI calculation has a wiggle at P_miss ~ 300 MeV. It is yet to be seen whether this is merely due to the lack of MEC and IC in the present theoretical calculation. However, a similar feature was observed in a previous Hall A experiment. Further, discrepancies at very low P_miss cast some doubt on neutron form factor measurements using the deuteron as target. This study will add to the already growing body of systematic data for the ^2H(e,e'p)n reaction to better understand the N N short range and to provide vital input for heavier nuclei.

  1. N2H4 electrooxidation at negative potential on novel wearable nano-Ni-MWNTs-textile electrode

    Highlights: • The novel Ni-MWNTs-textile electrode is prepared by the facile “dipping and drying” and electrodeposition process. • The Ni-MWNTs-textile electrode exhibits a special three dimensional network structure. • The Ni-MWNTs-textile electrode exhibits excellent performance for N2H4 electrooxidation. - Abstract: A new composite Ni electrode is simply prepared by electrodeposition of nano-scaled Ni particles onto multi-walled carbon nanotubes (MWNTs)-enabled conductive textile fiber (cosmetic cotton) which owns an especial three-dimensional (3D) network structure. The morphology and phase structure of the Ni-MWNTs-textile electrode are characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction spectrometer, and the catalytic performance for the N2H4 electrooxidation is tested by linear sweep voltammetry and chronoamperometry. The results show that the Ni-MWNTs-textile electrode exhibits a remarkably high catalytic activity and good stability for N2H4 electrooxidation. The onset potential stays at around −0.9 V and the oxidation current density reaches as high as 12 mA cm−2 in the solution containing 1 mol dm−3 NaOH and 20 mmol dm−3 N2H4 at around −0.80 V, both of which outstrip the previous reports

  2. A NOTE ON THE CONSTRUCTION OF SYMPLECTIC SCHEMES FOR SPLITABLE HAMILTONIAN H = H(1) + H(2) + H(3)

    Yifa Tang

    2002-01-01

    In this note, we will give a proof for the uniqueness of 4th-order time-reversible sym-plectic difference schemes of 13th-fold compositions of phase flows φtH(1), t tφH(2), φH(3) withdifferent temporal parameters for splitable hamiltonian H - H(1) + H(2) + H(3).

  3. 5,6-Dihydro-4-methoxy-2H-pyran-2-one, a new mycotoxin from Penicillium italicum

    The structure of 5,6-dihydro-4-methoxy-2H-pyran-2-one, a mycotoxin produced by Penicillium italicum, has been determined by spectroscopic methods. The 1H and 13C n.m.r. spectra are consistent with the assigned structure

  4. DNC/HNC and N2D+/N2H+ ratios in high-mass star forming cores

    Fontani, F; Furuya, K; Sakai, N; Aikawa, Y; Yamamoto, S

    2014-01-01

    Chemical models predict that the deuterated fraction (the column density ratio between a molecule containing D and its counterpart containing H) of N2H+, Dfrac(N2H+), is high in massive pre-protostellar cores and rapidly drops of an order of magnitude after the protostar birth, while that of HNC, Dfrac(HNC), remains constant for much longer. We tested these predictions by deriving Dfrac(HNC) in 22 high-mass star forming cores divided in three different evolutionary stages, from high-mass starless core candidates (HMSCs, 8) to high-mass protostellar objects (HMPOs, 7) to Ultracompact HII regions (UCHIIs, 7). For all of them, Dfrac (N2H+) was already determined through IRAM-30m Telescope observations, which confirmed the theoretical rapid decrease of Dfrac(N2H+) after protostar birth (Fontani et al. 2011). Therefore our comparative study is not affected by biases introduced by the source selection. We have found average Dfrac(HNC) of 0.012, 0.009 and 0.008 in HMSCs, HMPOs and UCHIIs, respectively, with no stati...

  5. Identification of Unsaturated and 2H Polyfluorocarboxylate Homologous Series and Their Detection in Environmental Samples and as Polymer Degradation Products

    A pair of homologous series of polyfluorinated degradation products have been identified, both having structures similar to perfluorocarboxylic acids but (i) having a H substitution for F on the α carbon for 2H polyfluorocarboxylic acids (2HPFCAs) and (ii) bearing a double ...

  6. Herbivory responsive C2H2 zinc finger transcription factor protein StZFP2 from potato

    While C2H2 zinc finger transcription factors are often regulated by abiotic stress, their role during insect infestation has been overlooked. This study demonstrates that the transcripts of the zinc finger transcription factors StZFP1 and StZFP2 are induced in potato (Solanum tuberosum) upon infesta...

  7. ACIDIFICATION OF RAIN IN THE PRESENCE OF SO2, H2O2, O3, AND HNO3

    The production of acid sulfate and the accumulation of acid nitrate are calculated for falling raindrops using a physico-chemical model that accounts for the mass transfer of SO2, H2O2, O3, HNO3, and CO2. The acidification is postulated to occur through the absorption of free gas...

  8. Acetylene (C2H2 and hydrogen cyanide (HCN from IASI satellite observations: global distributions, validation, and comparison with model

    V. Duflot

    2015-05-01

    Full Text Available We present global distributions of C2H2 and HCN total columns derived from the Infrared Atmospheric Sounding Interferometer (IASI. These distributions are obtained with a fast method allowing to retrieve C2H2 abundance globally with a 5% precision and HCN abundance in the tropical (subtropical belt with a 10% (30% precision. IASI data are compared for validation purposes with ground-based Fourier Transform Infrared (FTIR spectrometer measurements at four selected stations. We show that there is an overall agreement between the ground-based and space measurements. Global C2H2 and subtropical HCN abundances retrieved from IASI spectra show the expected seasonality linked to variations in the anthropogenic emissions and seasonal biomass burning activity, as well as exceptional events, and are in good agreement with previous spaceborne studies. IASI measurements are also compared to the distributions from the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4. Seasonal cycles observed from satellite data are reasonably well reproduced by the model. However, the model seems to overestimate (underestimate anthropogenic (biomass burning emissions and a negative global mean bias of 1% (16% of the model relative to the satellite observations was found for C2H2 (HCN.

  9. Non-isothermal Kinetics of the Dehydration Process of Na2MoO4·2H20

    张建军; 张秀芳; 武克忠; 任宁; 周雪; 刘晓地

    2004-01-01

    The dehydration process of Na2MoO4·2H2O and its kinetics have been studied by TG-DTG. Using Malek method, SB(m,n) was defined as the kinetic model of the dehydration process. The corresponding kinetic and thermodynamic parameters were obtained.

  10. Generalised Permutation Branes on a product of cosets $G_{k_1}/H\\times G_{k_2}/H$

    Sarkissian, Gor

    2006-01-01

    We study the modifications of the generalized permutation branes defined in hep-th/0509153, which are required to give rise to the non-factorizable branes on a product of cosets $G_{k_1}/H\\times G_{k_2}/H$. We find that for $k_1\

  11. Ring contraction of 3,6-Dihydro-2H-thiopyrans to thiolanes by an lodo-oxyacylation reaction

    Lucassen, A.C.B.; Zwanenburg, B.

    2004-01-01

    Reaction of functionalized 3,6-dihydro-2H-thiopyrans with N-iodosuccinimide in the presence of carboxylic acids results in the stereospecific formation of poly-functionalised thiolanes in good yield. The formation of these thiolanes is believed to proceed through either a nucleophilic or an electrop

  12. Superstaar Ott Lepland tõi Pärnu miksimeistrile B2H-le võidu / Andris Tammela

    Tammela, Andris

    2009-01-01

    Pärnu hiphopartistist B2H-st ehk Andres Selgojast, kes võitis Power Hit Radio korraldatud võistluse, milles tuli remiksida TV3 show' "Eesti otsib superstaari" finalistide lugusid. Võidu tõi remiks värske superstaari Ott Leplandi esitatud Snoop Dogi loost "Who I Am (Whats My Name)"

  13. Quartz crystal microbalance study of tungsten atomic layer deposition using WF6 and Si2H6

    The atomic layer deposition (ALD) of tungsten can be accomplished using sequential exposures of WF6 and Si2H6 (disilane). In this paper, W ALD is explored using in situ quartz crystal microbalance (QCM) measurements as a function of the reactant exposure and deposition temperature. The QCM measurements revealed that the WF6 reaction is self-limiting. In contrast, W ALD growth rates exhibited a slow and continual increase for disilane exposures > 4 x 104 L. The W ALD growth rate was also weakly temperature-dependent with an activation energy of 1.5 ± 0.1 kcal/mol at T 275 deg. C. The QCM results and previous Auger results for W ALD yield the relationship between the silicon coverage deposited during the Si2H6 exposure and the tungsten coverage deposited during the WF6 exposure. The W/Si atomic ratio of ∼ 1:1 is consistent with earlier Auger investigations of the surface chemistry during W ALD at 200 deg. C. The QCM measurements are also consistent with silicon coverages of 1.7-2.1 monolayers after the Si2H6 exposures. These high silicon coverages are believed to result by silylene insertion from Si2H6 into surface Si-H bonds

  14. A new ab initio potential energy surface for the collisional excitation of N2H+ by H2

    We compute a new potential energy surface (PES) for the study of the inelastic collisions between N2H+ and H2 molecules. A preliminary study of the reactivity of N2H+ with H2 shows that neglecting reactive channels in collisional excitation studies is certainly valid at low temperatures. The four dimensional (4D) N2H+–H2 PES is obtained from electronic structure calculations using the coupled cluster with single, double, and perturbative triple excitation level of theory. The atoms are described by the augmented correlation consistent triple zeta basis set. Both molecules were treated as rigid rotors. The potential energy surface exhibits a well depth of ≃2530 cm−1. Considering this very deep well, it appears that converged scattering calculations that take into account the rotational structure of both N2H+ and H2 should be very difficult to carry out. To overcome this difficulty, the “adiabatic-hindered-rotor” treatment, which allows para-H2(j = 0) to be treated as if it were spherical, was used in order to reduce the scattering calculations to a 2D problem. The validity of this approach is checked and we find that cross sections and rate coefficients computed from the adiabatic reduced surface are in very good agreement with the full 4D calculations

  15. A combined crossed molecular beams and theoretical study of the reaction CN + C{sub 2}H{sub 4}

    Balucani, Nadia, E-mail: nadia.balucani@unipg.it [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Leonori, Francesca; Petrucci, Raffaele [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Wang, Xingan [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Casavecchia, Piergiorgio [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Skouteris, Dimitrios [Scuola Normale Superiore, Pisa (Italy); Albernaz, Alessandra F. [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Gargano, Ricardo [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, FL 32611 (United States)

    2015-03-01

    Highlights: • The CN + C{sub 2}H{sub 4} reaction was investigated in crossed beam experiments. • Electronic structure calculations of the potential energy surface were performed. • RRKM estimates qualitatively reproduce the experimental C{sub 2}H{sub 3}NC yield. - Abstract: The CN + C{sub 2}H{sub 4} reaction has been investigated experimentally, in crossed molecular beam (CMB) experiments at the collision energy of 33.4 kJ/mol, and theoretically, by electronic structure calculations of the relevant potential energy surface and Rice–Ramsperger–Kassel–Marcus (RRKM) estimates of the product branching ratio. Differently from previous CMB experiments at lower collision energies, but similarly to a high energy study, we have some indication that a second reaction channel is open at this collision energy, the characteristics of which are consistent with the channel leading to CH{sub 2}CHNC + H. The RRKM estimates using M06L electronic structure calculations qualitatively support the experimental observation of C{sub 2}H{sub 3}NC formation at this and at the higher collision energy of 42.7 kJ/mol of previous experiments.

  16. Computational study on the negative electron affinities of NO2 -.(H2O)n clusters (n=0-30).

    Ejsing, Anne Marie; Brøndsted Nielsen, Steen

    2007-04-21

    Here we report negative electron affinities of NO(2)(-).(H2O)n clusters (n=0-30) obtained from density functional theory calculations and a simple correction to Koopmans' theorem. The method relies on the calculation of the detachment energy of the monoanion and its highest occupied molecular orbital and lowest unoccupied molecular orbital energies, and explicit calculations on the dianion itself are avoided. A good agreement with resonances in the cross section for neutral production in electron scattering experiments is found for n=0, 1, and 2. We find several isomeric structures of NO(2)(-).(H2O)2 of similar energy that elucidate the interplay between water-water and ion-water interactions. The topology is predicted to influence the electron affinity by 0.5 and 0.4 eV for NO(2)(-).(H2O) and NO(2)(-).(H2O)2, respectively. The electron affinity of larger clusters is shown to follow a (n+delta)-1/3 dependence, where delta=3 represents the number of water molecules that in volume, could replace NO(2) (-). PMID:17461632

  17. N2H+ and N15NH+ toward the prestellar core 16293E in L1689N

    Daniel, F.; Faure, A.; Pagani, L.; Lique, F.; Gérin, M.; Lis, D.; Hily-Blant, P.; Bacmann, A.; Roueff, E.

    2016-07-01

    Context. Understanding the processes that could lead to an enrichment of molecules in 15N atoms is of particular interest because this may shed light on the relatively strong variations observed in the 14N/15N ratio in various solar system environments. Aims: The sample of molecular clouds where 14N/15N ratios have been measured currently is small and has to be enlarged to allow statistically significant studies. In particular, the N2H+ molecule currently shows the broadest spread of 14N/15N ratios in high-mass star-forming regions. However, the 14N/15N ratio in N2H+ was obtained in only two low-mass star-forming regions (L1544 and B1b). We here extend this sample to a third dark cloud. Methods: We targeted the 16293E prestellar core, where the N15NH+J = 1-0 line was detected. Using a model previously developed for the physical structure of the source, we solved the molecular excitation with a nonlocal radiative transfer code. For this purpose, we computed specific collisional rate coefficients for the N15NH+-H2 collisional system. As a first step of the analysis, the N2H+ abundance profile was constrained by reproducing the N2H+J = 1-0 and 3-2 maps. A scaling factor was then applied to this profile to match the N15NH+J = 1-0 spectrum. Results: We derive a column density ratio N2H+/N15NH. Conclusions: We performed a detailed analysis of the excitation of N2H+ and N15NH+ in the direction of the 16293E core with modern models that solve the radiative transfer and with the most accurate collisional rate coefficients available to date. We obtained the third estimate of the N2H+/N15NH+ column density ratio in the direction of a cold prestellar core. The current estimate ~330 agrees with the typical value of the elemental isotopic ratio in the local interstellar medium. It is lower than in some other cores, however, where values as high as 1300 have been reported.

  18. Constraints on Asian and European sources of methane from CH4-C2H6-CO correlations in Asian outflow

    Xiao, Yaping; Jacob, Daniel J.; Wang, James S.; Logan, Jennifer A.; Palmer, Paul I.; Suntharalingam, Parvadha; Yantosca, Robert M.; Sachse, Glen W.; Blake, Donald R.; Streets, David G.

    2004-08-01

    Aircraft observations of Asian outflow from the Transport and Chemical Evolution Over the Pacific (TRACE-P) aircraft mission over the NW Pacific (March and April 2001) show large CH4 enhancements relative to background, as well as strong CH4-C2H6-CO correlations that provide signatures of regional sources. We apply a global chemical transport model simulation of the CH4-C2H6-CO system for the TRACE-P period to interpret these observations in terms of CH4 sources and to explore in particular the unique constraints from the CH4-C2H6-CO correlations. We use as a priori a global CH4 source inventory constrained with National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory (CMDL) surface observations [Wang et al., 2004]. We find that the observed CH4 concentration enhancements and CH4-C2H6-CO correlations in Asian outflow in TRACE-P are determined mainly by anthropogenic emissions from China and Eurasia (defined here as Europe and eastern Russia), with only little contribution from tropical sources (wetlands and biomass burning). The a priori inventory overestimates the observed CH4 enhancements and shows regionally variable biases for the CH4/C2H6 slope. The CH4/CO slopes are simulated without significant bias. Matching both the observed CH4 enhancements and the CH4-C2H6-CO slopes in Asian outflow requires increasing the east Asian anthropogenic source of CH4, and decreasing the Eurasian anthropogenic source, by at least 30% for both. The need to increase the east Asian source is driven by the underestimate of the CH4/C2H6 slope in boundary layer Chinese outflow. The Streets et al. [2003] anthropogenic emission inventory for east Asia fits this constraint by increasing CH4 emissions from that region by 40% relative to the a priori, largely because of higher livestock and landfill source estimates. Eurasian sources (mostly European) then need to be reduced by 30-50% from the a priori value of 68 Tg yr-1. The decrease of

  19. H(2): The Critical Juncture between Polymerization and Dissociation of Hydrocarbons in a Low-temperature Plasma

    Hansen, T. A. R.; R. van de Sanden,; Engeln, R.

    2011-01-01

    The chemistry in an argon plasma jet, admixed with a small percentage of CH(4), C(2)H(2), H(2) and mixtures thereof, is investigated by means of residual gas analysis. Polymerization of such hydrocarbon precursors is known to occur when their densities exceed the Ar(+) ion density. This paper shows

  20. Deuterium NMR of Val1...(2-2H)Ala3...gramicidin A in oriented DMPC bilayers

    Deuterium NMR is used to study the selectively labeled Val1...(2-2H)Ala3...gramicidin A molecule to investigate the structure and dynamics of the C alpha-2H bond in the Ala3 residue of gramicidin. Val1...(2-2H)Ala3...gramicidin A is synthesized, purified, and characterized and then incorporated into oriented bilayers of dimyristoylphosphatidylcholine sandwiched between glass coverslips. Phosphorus NMR line shapes obtained from this sample are consistent with the presence of the bilayer phase and indicate that no nonbilayer phases are present in significant amounts. Deuterium NMR line shapes obtained from this sample indicate that the motional axis of the gramicidin Ala3 residue is parallel to the coverslip normal, that the distribution of motional axis orientations has a width of 2 degrees, and that only one major conformational and dynamical state of the Ala3 C alpha-2H bond is observed on the NMR time scale. Furthermore, the Ala3 C alpha-2H bond angle relative to the motional axis is 19-20 degrees if fast axial rotation is assumed to be the only motion present but is less than or equal to 19-20 degrees in the absence of such an assumption. This result indicates that various double-stranded, helical dimer models are very unlikely to represent the structure of gramicidin in the sample studied but that the single-stranded, beta 6.3 helical dimer models are consistent with the experimental data. However, a definitive distinction between the left-handed, single-stranded, beta 6.3 helical dimer model and the right-handed, single-stranded, beta 6.3 helical dimer model cannot be made on the basis of the experimental data obtained in this study

  1. Analyses of Weapons-Grade MOX VVER-1000 Neutronics Benchmarks: Pin-Cell Calculations with SCALE/SAS2H

    Ellis, R.J.

    2001-01-11

    A series of unit pin-cell benchmark problems have been analyzed related to irradiation of mixed oxide fuel in VVER-1000s (water-water energetic reactors). One-dimensional, discrete-ordinates eigenvalue calculations of these benchmarks were performed at ORNL using the SAS2H control sequence module of the SCALE-4.3 computational code system, as part of the Fissile Materials Disposition Program (FMDP) of the US DOE. Calculations were also performed using the SCALE module CSAS to confirm the results. The 238 neutron energy group SCALE nuclear data library 238GROUPNDF5 (based on ENDF/B-V) was used for all calculations. The VVER-1000 pin-cell benchmark cases modeled with SAS2H included zero-burnup calculations for eight fuel material variants (from LEU UO{sub 2} to weapons-grade MOX) at five different reactor states, and three fuel depletion cases up to high burnup. Results of the SAS2H analyses of the VVER-1000 neutronics benchmarks are presented in this report. Good general agreement was obtained between the SAS2H results, the ORNL results using HELIOS-1.4 with ENDF/B-VI nuclear data, and the results from several Russian benchmark studies using the codes TVS-M, MCU-RFFI/A, and WIMS-ABBN. This SAS2H benchmark study is useful for the verification of HELIOS calculations, the HELIOS code being the principal computational tool at ORNL for physics studies of assembly design for weapons-grade plutonium disposition in Russian reactors.

  2. A Preliminary Study of the Plasma Pyrolysis of Waste Tyres

    唐兰; 黄海涛; 赵增立; 吴创之

    2003-01-01

    Thermal plasma pyrolysis of waste tyres for recovering energy was performed in a nitrogen plasma reactor. The main gaseous products were identified by chromatography as H2, CO, CH4, C2H2 and so on. From a series of experiments, the effects of the process parameters of thermal plasma pyrolysis were investigated. Under our experimental conditions with steam injection, the total contents of H2 and CO reached up to 38.3% in the gas product, C2H2 up to 4%, and the maximum calorific value of the pyrolysis gas was 8.96 MJ/m3. The results indicate that plasma-assisted thermal decomposition of waste tyre particles may be a useful way for recovering energy and useful chemicals.

  3. FTIR time-series of biomass burning products (HCN, C2H6, C2H2, CH3OH, and HCOOH) at Reunion Island (21° S, 55° E) and comparisons with model data

    Vigouroux, C.; Stavrakou, T.; Whaley, C.; Dils, B.; Duflot, V.; Hermans, C.; Kumps, N.; Metzger, J.-M.; Scolas, F.; Vanhaelewyn, G.; Müller, J.-F.; Jones, D. B. A.; Li, Q.; De Mazière, M.

    2012-11-01

    Reunion Island (21° S, 55° E), situated in the Indian Ocean at about 800 km east of Madagascar, is appropriately located to monitor the outflow of biomass burning pollution from Southern Africa and Madagascar, in the case of short-lived compounds, and from other Southern Hemispheric landmasses such as South America, in the case of longer-lived species. Ground-based Fourier transform infrared (FTIR) solar absorption observations are sensitive to a large number of biomass burning products. We present in this work the FTIR retrieval strategies, suitable for very humid sites such as Reunion Island, for hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), methanol (CH3OH), and formic acid (HCOOH). We provide their total columns time-series obtained from the measurements during August-October 2004, May-October 2007, and May 2009-December 2010. We show that biomass burning explains a large part of the observed seasonal and interannual variability of the chemical species. The correlations between the daily mean total columns of each of the species and those of CO, also measured with our FTIR spectrometer at Reunion Island, are very good from August to November (R ≥ 0.86). This allows us to derive, for that period, the following enhancement ratios with respect to CO: 0.0047, 0.0078, 0.0020, 0.012, and 0.0046 for HCN, C2H6, C2H2, CH3OH, and HCOOH, respectively. The HCN ground-based data are compared to the chemical transport model GEOS-Chem, while the data for the other species are compared to the IMAGESv2 model. We show that using the HCN/CO ratio derived from our measurements (0.0047) in GEOS-Chem reduces the underestimation of the modeled HCN columns compared with the FTIR measurements. The comparisons between IMAGESv2 and the long-lived species C2H6 and C2H2 indicate that the biomass burning emissions used in the model (from the GFED3 inventory) are probably underestimated in the late September-October period for all years of measurements, and especially in

  4. Plasma reactor

    Molina Mansilla, Ricardo; Erra Serrabasa, Pilar; Bertrán Serra, Enric

    2008-01-01

    [EN] A plasma reactor that can operate in a wide pressure range, from vacuum and low pressures to atmospheric pressure and higher pressures. The plasma reactor is also able to regulate other important settings and can be used for processing a wide range of different samples, such as relatively large samples or samples with rough surfaces.

  5. Plasma properties

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  6. PLASMA DEVICE

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  7. Is the Reaction of C3N(-) with C2H2 a Possible Process for Chain Elongation in Titan's Ionosphere?

    Lindén, Fredrik; Alcaraz, Christian; Ascenzi, Daniela; Guillemin, Jean-Claude; Koch, Leopold; Lopes, Allan; Polášek, Miroslav; Romanzin, Claire; Žabka, Jan; Zymak, Illia; Geppert, Wolf D

    2016-07-14

    The reaction of C3N(-) with acetylene was studied using three different experimental setups, a triple quadrupole mass spectrometer (Trento), a tandem quadrupole mass spectrometer (Prague), and the "CERISES" guided ion beam apparatus at Orsay. The process is of astrophysical interest because it can function as a chain elongation mechanism to produce larger anions that have been detected in Titan's ionosphere by the Cassini Plasma Spectrometer. Three major products of primary processes, C2H(-), CN(-), and C5N(-), have been identified, whereby the production of the cyanide anion is probably partly due to collisional induced dissociation. The formations of all these products show considerable reaction thresholds and also display comparatively small cross sections. Also, no strong signals of anionic products for collision energies lower than 1 eV have been observed. Ab initio calculations have been performed to identify possible pathways leading to the observed products of the title reaction and to elucidate the thermodynamics of these processes. Although the productions of CN(-) and C5N(-) are exoergic, all reaction pathways have considerable barriers. Overall, the results of these computations are in agreement with the observed reaction thresholds. Due to the existence of considerable reaction energy barriers and the small observed cross sections, the title reaction is not very likely to play a major role in the buildup of large anions in cold environments like the interstellar medium or planetary and satellite ionospheres. PMID:27135984

  8. Plasma polymerization for cell adhesive/anti-adhesive implant coating

    Meichsner, Juergen; Testrich, Holger; Rebl, Henrike; Nebe, Barbara

    2015-09-01

    Plasma polymerization of ethylenediamine (C2H8N2, EDA) and perfluoropropane (C3F8, PFP) with admixture of argon and hydrogen, respectively, was studied using an asymmetric 13.56 MHz CCP. The analysis of the plasma chemical gas phase processes for stable molecules revealed consecutive reactions: C2H8N2 consumption, intermediate product NH3, and main final product HCN. In C3F8- H2 plasma the precursor molecule C3F8 and molecular hydrogen are consumed and HF as well as CF4 and C2F6 are found as main gaseous reaction products. The deposited plasma polymer films on the powered electrode are strongly cross-linked due to ion bombardment. The stable plasma polymerized films from EDA are characterized by high content of nitrogen with N/C ratio of about 0.35. The plasma polymerized fluorocarbon film exhibit a reduced F/C ratio of about 1.2. Adhesion tests with human osteoblast cell line MG-63 on coated Ti6Al4V samples (polished) compared with uncoated reference sample yielded both, the enhanced cell adhesion for plasma polymerized EDA and significantly reduced cell adhesion for fluorocarbon coating, respectively. Aging of the plasma polymerized EDA film, in particular due to the reactions with oxygen from air, showed no significant change in the cell adhesion. The fluorocarbon coating with low cell adhesion is of interest for temporary implants. Funded by the Campus PlasmaMed.

  9. An alternative calculation technique in the generator-coordinate method (GCM) to determine the ground state energies of 2H and 4He and the electric quadrupole moment of 2H

    An alternative calculation technique in the generator-coordinate method (GCM) has been proposed in which square-well potential between nucleon-pairs is employed, instead of the harmonic oscillator potential of the HOSM (harmonic oscillator shell model). The eigen-function of the Schroedinger equation with nucleon-pair Hamiltonian replaces the HOSM wave function and its kernels. The GCM kernels are projected out on an arbitrary non-orthonormal function, whereas the total wave function is expanded in terms of this function to obtain standard eigen-values equation. Ground state energies of 2H and 4He and the electric quadrupole moment of 2H were calculated and the results were compared to the Variational Monte Carlo (VMC) calculation and experiential data. (author)

  10. Covariance mapping of two-photon double core hole states in C 2 H 2 and C 2 H 6 produced by an x-ray free electron laser

    Few-photon ionization and relaxation processes in acetylene (C2H2) and ethane (C2H6) were investigated at the linac coherent light source x-ray free electron laser (FEL) at SLAC, Stanford using a highly efficient multi-particle correlation spectroscopy technique based on a magnetic bottle. The analysis method of covariance mapping has been applied and enhanced, allowing us to identify electron pairs associated with double core hole (DCH) production and competing multiple ionization processes including Auger decay sequences. The experimental technique and the analysis procedure are discussed in the light of earlier investigations of DCH studies carried out at the same FEL and at third generation synchrotron radiation sources. In particular, we demonstrate the capability of the covariance mapping technique to disentangle the formation of molecular DCH states which is barely feasible with conventional electron spectroscopy methods

  11. Etude théorique de surfaces d'énergie potentielle, de moment dipolaire et de polarizabilité des complexes de van der Waals CH4-N2 et C2H4-C2H4

    Kalugina, Yulia

    2010-01-01

    Dans cette thèse, des calculs ab initio et analytiques ont été effectués pour déterminer les surfaces d'énergie potentielle, de moment dipolaire et de polarisabilité des complexes de van der Waals faiblement liés CH4-N2 et C2H4-C2H4, pour une large gamme de distances intermoléculaires et de configurations, dans l'approximation des molécules en interaction rigides. Pour les calculs ab initio, la méthode CCSD(T), CCSD(T)-F12, ainsi que les méthodes moins couteuses MP2, MP2-F12, SAPT et DFT-SAPT...

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

    A new inorganic-organic compound [Cu(O2C–CH2–CO2H)2·2H2O] ([Cumal]) was hydrothermally synthesized and characterized by IR spectroscopy, thermal analysis and single crystal X-ray diffraction. [Cumal] is the first three-dimensional compound existing in the system Cu(II)–malonic acid–H2O. Its framework is built up through carboxyl bridged copper where CuO6 octahedra are elongated with an almost D4h symmetry (4+2) due to the Jahn–Teller effect. The magnetic properties were studied by measuring its magnetic susceptibility in the temperature range of 2–300 K indicating the existence of weak ferromagnetic interactions. The electronic structure of [Cumal] was calculated within the density functional theory (DFT) framework. Structural features are well reproduced using DFT structural optimizations and the optical spectra, calculated within the dielectric formalism, explain very well the light blue colour of the compound. It is shown that a GGA+U approach with a Ueff value of about 6 eV is necessary for a better correlation with the experiment. - Graphical abstract: [Cu(O2C–CH2–CO2H)2·2H2O]: the first 3D hybrid organic–inorganic compound built up carboxyl groups. The network presents a diamond-like structure achieved via carboxyl. Highlights: ► A new organic–inorganic material with an unprecedented topology is synthesized. ► Crystallographic structure is determined using single crystal X-ray diffraction. ► Electronic structure is obtained from DFT, GGA+U calculation. ► Framework can be described as formed from CuC4 tetrahedron sharing four corners. ► This structure can be classified as an extended diamond structure.

  13. Upper limit for the D2H+ ortho-to-para ratio in the prestellar core 16293E (CHESS)

    Vastel, C.; Caselli, P.; Ceccarelli, C.; Bacmann, A.; Lis, D. C.; Caux, E.; Codella, C.; Beckwith, J. A.; Ridley, T.

    2012-11-01

    The H_3^+ ion plays a key role in the chemistry of dense interstellar gas clouds where stars and planets are forming. The low temperatures and high extinctions of such clouds make direct observations of H_3^+ impossible, but lead to large abundances of H2D+ and D2H+, which are very useful probes of the early stages of star and planet formation. The ground-state rotational ortho-D2H+ 11,1-00,0 transition at 1476.6 GHz in the prestellar core 16293E has been searched for with the Herschel HIFI instrument, within the CHESS (Chemical HErschel Surveys of Star forming regions) Key Program. The line has not been detected at the 21 mK km s-1 level (3σ integrated line intensity). We used the ortho-H2D+ 11,0-11,1 transition and para-D2H+ 11,0-10,1 transition detected in this source to determine an upper limit on the ortho-to-para D2H+ ratio as well as the para-D2H+/ortho-H2D+ ratio from a non-local thermodynamic equilibrium analysis. The comparison between our chemical modeling and the observations suggests that the CO depletion must be high (larger than 100), with a density between 5 × 105 and 106 cm-3. Also the upper limit on the ortho-D2H+ line is consistent with a low gas temperature (~11 K) with a ortho-to-para ratio of 6 to 9, i.e. 2 to 3 times higher than the value estimated from the chemical modeling, making it impossible to detect this high frequency transition with the present state of the art receivers. The chemical network is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A33Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  14. Equilibrium 2H/ 1H fractionations in organic molecules. II: Linear alkanes, alkenes, ketones, carboxylic acids, esters, alcohols and ethers

    Wang, Ying; Sessions, Alex L.; Nielsen, Robert J.; Goddard, William A., III

    2009-12-01

    Equilibrium 2H/ 1H fractionation factors (α eq) for various H positions in alkanes, alkenes, ketones, carboxylic acids, esters, alcohols, and ethers were calculated between 0 and 100 °C using vibrational frequencies from ab initio QM calculations (B3LYP/6-311G**). Results were then corrected using a temperature-dependent linear calibration curve based on experimental data for H α in ketones ( Wang et al., 2009). The total uncertainty in reported α eq values is estimated at 10-20‰. The effects of functional groups were found to increase the value of α eq for H next to electron-donating groups, e.g. sbnd OR, sbnd OH or sbnd O(C dbnd O)R, and to decrease the value of α eq for H next to electron-withdrawing groups, e.g. sbnd (C dbnd O)R or sbnd (C dbnd O)OR. Smaller but significant functional group effects are also observed for H β and sometimes H γ. By summing over individual H positions, we estimate the equilibrium fractionation relative to water to be -90‰ to -70‰ for n-alkanes and around -100‰ for pristane and phytane. The temperature dependence of these fractionations is very weak between 0 and 100 °C. Our estimates of α eq agree well with field data for thermally mature hydrocarbons (δ 2H values between -80‰ and -110‰ relative to water). Therefore the observed δ 2H increase of individual hydrocarbons and the disappearance of the biosynthetic δ 2H offset between n-alkyl and linear isoprenoid lipids during maturation of organic matter can be confidently attributed to H exchange towards an equilibrium state. Our results also indicate that many n-alkyl lipids are biosynthesized with δ 2H values that are close to equilibrium with water. In these cases, constant down-core δ 2H values for n-alkyl lipids cannot be reliably used to infer a lack of isotopic exchange.

  15. Molecular structural visualization and micro-structural features of 4,6-dimethyl-3-cyanopyridine-(2H)-selenone

    Graphical abstract: Packing and spacefill unit cells of 4,6-dimethyl-3-cyanopyridine-(2H)-selenone with different plans of symmetry showing selenium-ion as nucleation center. Highlights: ► Compound(I) 4,6-dimethyl-3-cyanopyridine-(2H)-selenone is mainly belongs to monoclinic crystal structure with P21/n space group as confirmed in crystallographic data. ► XRD-powder diffraction could used as quantitative tool for estimating different phases for small nucleus of organic compounds. ► There are four types of H-bonding two are intra-H-bond in the same molecule of 4,6-dimethyl-3-cyanopyridine-(2H)-selenone which are Se⋯H⋯CN and Se⋯H⋯N while the others two inter-H-bond are Se⋯H⋯N and Se⋯H⋯Se, these four types of hydrogen bonding are responsible for forming 3D-framnet of 4,6-dimethyl-3-cyanopyridine-(2H)-selenone as solid array material. ► The visualized investigations exhibited good fitting with experimental data. ► The average grain size was calculated and found in between 1.13 μm and 2.91 μm which is relatively high in contrast with that calculated throughly applying Scherrer's formula for pure 4,6-dimethyl-3-cyanopyridine-(2H)-selenone monoclinic-phase (D ∼ 0.89 μm). - Abstract: The compound of selenium containing heterocycles namely (I) 4,6-dimethyl-3-cyanopyridine-(2H)-selenone (C8H8N2Se) was used as model to investigate the structural and micro-structural features of some selected selenones. Visualization of molecular structure of selenium containing moiety was accurately investigated to clarify role of selenium ion in nucleation process of forming 3D-framenet of H-bonded of substituted selenones. Bond distances, torsions on angles of investigated compound were compared with others crystal data to confirm crystal structures of substituted selenones which is monoclinic crystal form with P21/n space group.

  16. Plasma universe

    Traditionally the views in our cosmic environment have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasma. Such a medium may also emit synchrotron radiation which is observable in the radio region. If we try to base a model of the universe on the plasma phenomena mentioned we find that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasma. This approach is possible because it is likely that the basic properties of plasma are the same everywhere. In order to test the usefulness of the plasma universe model we apply it to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4-5 bilions years ago with an accuracy of better than 1 percent

  17. Plasma physics

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  18. Plasma chemistry in an atmospheric pressure Ar/NH3 dielectric barrier discharge

    Fateev, A.; Leipold, F.; Kusano, Y.;

    2005-01-01

    An atmospheric pressure dielectric barrier discharge (DBD) in Ar/NH3 (0.1 - 10%) mixtures with a parallel plate electrode geometry was studied. The plasma was investigated by emission and absorption spectroscopy in the UV spectral range. Discharge current and voltage were measured as well. UV...... absorption spectroscopy was also employed for the detection of stable products in the exhaust gas. To clarify the different processes for ammonia decomposition, N-2(2 - 10%) was added to the plasma. Modeling of the chemical kinetics in an Ar/NH3 plasma was performed as well. The dominant stable products of...... an atmospheric pressure Ar/NH3 DBD are H-2, N-2 and N2H4. The hydrazine (N2H4) concentration in the plasma and in the exhaust gases at various ammonia concentrations and different discharge powers was measured. Thermal N2H4 decomposition into NH2 radicals may be used for NOx reduction processes....

  19. Separation of Th and Zr from acid medium by 3-formyl-4-hydroxy-N-methyl 2(H) quinoline

    3-Formyl-4-hydroxy-N-methyl 2(H) quinoline (FHMQ) was synthesized and characterized. This compound was found not soluble in water or nitric acid solutions of different concentration. The uptake of Zr and Th from nitric acid by FHMQ has been investigated. The effect of shaking time on the percent uptake was studied. It was found that the equilibrium uptake of Zr is reached in one step after 2 hrs while in case of Th 4 hrs was required to reach equilibrium. The effect of nitric acid, metal ion and FHMQ on Zr uptake was studied. Studies on the retention capacity of 3-formyl-4-hydroxy-N-methyl 2(H) quinoline showed that its capacity decreases by increasing the nitric acid concentration for both Zr and Th. From the results obtained a selective method for separation of Zr from Th and U(VI) was developed using a floating bed column. (author)

  20. Vibrational properties of 2H-PbI{sub 2} semiconductors studied via Density Functional Theory calculations

    Pedesseau, L., E-mail: laurent.pedesseau@insa.rennes.fr [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France); Even, J. [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France); Katan, C. [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France); CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, 35042 Rennes (France); Raouafi, F. [Laboratoire de Physico-chimie des matériaux polymères, Institut Préparatoire aux Etudes Scientifiques et Techniques, BP51, 2070 La Marsa (Tunisia); Wei, Y.; Deleporte, E. [Laboratoire de Photonique Quantique et Moléculaire, Ecole Normale Supérieure de Cachan, 61 Avenue du Président Wilson, 94 235 Cachan Cedex (France); Jancu, J.-M. [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France)

    2013-08-31

    Density Functional Theory is used to study the vibrational properties of 2H-PbI{sub 2} semiconductor. The Born charge tensors are determined. Calculated phonon frequencies at the Brillouin zone center are compared to Raman scattering and IR absorption measurements. The computed Raman spectra show a good agreement with available experimental data. The simulated phonon dispersion curves are compared with triple-axis neutron scattering measurements. - Highlights: ► Symmetry properties of the optical phonons of the 2H-PbI{sub 2} crystal are analysed. ► Born charges and the dynamical matrix are calculated the Brillouin zone center. ► Raman spectra and Phonon dispersion have been compared with experimental results. ► Dielectric tensors are calculated and compared to measurements.

  1. Temperature Dependent Product Yields for the Spin Forbidden Singlet Channel of the C(3P) + C2H2 Reaction

    Hickson, Kevin M; Wakelam, Valentine

    2016-01-01

    The atomic hydrogen formation channels of the C + C2H2 reaction have been investigated using a continuous supersonic flow reactor over the 52 K 296 K temperature range. H-atoms were detected directly at 121.567 nm by vacuum ultraviolet laser induced fluorescence. Absolute H-atom yields were determined by comparison with the H-atom signal generated by the C + C2H4 reaction. The product yields agree with earlier crossed beam experiments employing universal detection methods. Incorporating these branching ratios in a gas-grain model of dense interstellar clouds increases the cC3H abundance. This reaction is a minor source of C3 containing molecules in the present simulations.

  2. An MP2 investigation on the encapsulation of H2 and 2H2 inside C50 fullerene

    Zeinalinezhad, Alireza; Sahnoun, Riadh; Nambiar, Vishnu P.; Aziz, Madzlan

    2014-02-01

    The possibility of encapsulation of one and two H2 molecule inside C50 fullerene was investigated at MP2 level of theory. By calculating the complexation energy, it was confirmed that H2@C50 complex is thermodynamically stable, while 2H2@C50 one is unstable. This was evidenced by negative complexation energy for H2@C50 and positive one for 2H2@C50 calculated using different basis sets. Examination of the host-guest interaction forces and strain energies in both complexes and the maximum expansion of the C50 cage before C-C bonds breaking also proved that only one H2 can reside inside the C50 cage.

  3. Chemical synthesis and characterization of hydrous tin oxide (SnO2:H2O) thin films

    S N Pusawale; P R Deshmukh; C D Lokhande

    2011-10-01

    In the present investigation, we report chemical synthesis of hydrous tin oxide (SnO2:H2O) thin films by successive ionic layer adsorption and reaction (SILAR) method at room temperature (∼300 K). The films are characterized for their structural and surface morphological properties. The formation of nanocrystalline SnO2 with porous and agglomerated particle morphology is revealed from X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies, respectively. The Fourier transform infrared spectroscopy (FTIR) study confirmed the formation of Sn–O phase and hydrous nature of the deposited film. Static water contact angle studies showed the hydrophilic nature of SnO2:H2O thin film. Electrical resistivity showed the semiconducting behaviour with room temperature electrical resistivity of 105 cm. The electrochemical properties studied in 0.5 M Na2SO4 electrolyte showed a specific capacitance of 25 F g-1 at 5 mVs-1 scan rate.

  4. First direct measurement of the 2H(α,γ)6Li cross section at Big Bang energies at LUNA

    The amount of 6Li produced during the Big Bang Nucleosynthesis (BBN) era can be theoretically estimated on the basis of cosmological and nuclear astrophysics knowledge. The latter strongly depends on the measurement of the nuclear cross section of the processes involved in the production and destruction of 6Li during the first stages of the Universe. Whereas the destruction process cross sections are well known, the reaction that dominates the 6Li production, the 2H(α,γ)6Li, has never been directly measured in the BBN energy range and only upper limits coming from indirect measurements are available till now. Here we report the first direct measurement of the 2H(α,γ)6Li cross section at BBN energies obtained at LUNA (Laboratory for Underground Nuclear Astrophysics, LNGS, Italy). (author)

  5. Design of Highly Sensitive C2H5OH Sensors Using Self-Assembled ZnO Nanostructures

    Jong-Heun Lee

    2011-10-01

    Full Text Available Various ZnO nanostructures such as porous nanorods and two hierarchical structures consisting of porous nanosheets or crystalline nanorods were prepared by the reaction of mixtures of oleic-acid-dissolved ethanol solutions and aqueous dissolved Zn-precursor solutions in the presence of NaOH. All three ZnO nanostructures showed sensitive and selective detection of C2H5OH. In particular, ultra-high responses (Ra/Rg = ~1,200, Ra: resistance in air, Rg: resistance in gas to 100 ppm C2H5OH was attained using porous nanorods and hierarchical structures assembled from porous nanosheets, which is one of the highest values reported in the literature. The gas response and linearity of gas sensors were discussed in relation to the size, surface area, and porosity of the nanostructures.

  6. CO2/H2 Methanation Reactivity of Nickel Oxide Based Catalyst Prepared from Different Nickel Salt Precursors

    The catalytic activity of NiO based catalyst prepared from different salt precursors of acetate, nitrate and sulphate salts were investigated towards CO2/H2 methanation reaction, in order to study the effect of type of precursor on the reactivity of the catalyst prepared. Results obtained showed that the NiO based catalyst prepared from nitrate precursor gave highest catalytic activity with 80.03% methanation of CO2 at 500 deg. C of the reaction temperature. Characterization techniques such as FTIR, XRD and SEM were carried out to see the effect of various physical properties of the NiO based catalyst obtained from different salts precursors used, which contributed in a good CO2/H2 methanation reactivity of the catalyst.

  7. Conformational adaptation of 2H-Tetraphenylporphyrin at Fe/Si(1 0 0 interface during metalation

    Chhagan Lal

    2014-01-01

    Full Text Available Many recent studies have highlighted the possibility to tailor the physical and chemical properties of porphyrin at the molecular level to design novel catalysts, sensors and devices with applications in electronics, opto-electronics, etc. In the present work we study the electronic properties of 2H-Tetraphenylporphyrin (2H-TPP on iron (Fe and iron silicide (Fe3Si onto Si (1 0 0 substrate using X-ray and Ultraviolet photoelectron spectroscopy (XPS & UPS. The results revealed that the iron atom is coordinated by TPP molecules at Fe/Si system. XPS results provide evidence of the iron coordination with TPP molecules. The UPS analysis show the fine structure in the electronic spectra related to HOMO states below the Fermi level.

  8. Updated evidence of the Trojan horse particle invariance for the 2H(d,p)3H reaction

    Pizzone, R. G.; Spitaleri, C.; Bertulani, C. A.; Mukhamedzhanov, A. M.; Blokhintsev, L.; La Cognata, M.; Lamia, L.; Rinollo, A.; Spartá, R.; Tumino, A.

    2013-02-01

    The Trojan horse nucleus invariance for the binary d(d,p)t reaction was tested by means of an experiment using the quasifree 2H(6Li,pt)4He and 2H(3He,pt)H reactions after 6Li and 3He breakup, respectively. The astrophysical S(E) factor for the d(d,p)t binary process was extracted from the present data in the framework of the plane wave approximation applied to the two different breakup schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement confirms the applicability of the plane wave approximation and suggests the independence of the binary indirect cross section on the chosen Trojan horse nucleus also for the present case.

  9. Updated evidences of the Trojan Horse particle invariance for $^2$H(d,p)$^3$H reaction

    Pizzone, R G; Bertulani, C A; Mukhamedzhanov, A M; Blokhintsev, L; La Cognata, M; Lamia, L; Rinollo, A; Spartá, R; Tumino, A

    2012-01-01

    The Trojan Horse nucleus invariance for the binary d(d,p)t reaction was tested using the quasi free $^2$H($^6$Li, pt)$^4$He and $^2$H($^3$He,pt)H reactions after $^6$Li and $^3$He break-up, respectively. The astrophysical S(E)-factor for the d(d,p)t binary process was then extracted in the framework of the Plane Wave Approximation applied to the two different break-up schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement confirms the applicability of the Plane Wave Approximation and suggests the independence of binary indirect cross section on the chosen Trojan Horse nucleus also for the present case.

  10. Analysis of heavy water production plant using bithermal and monothermal H2/H2O isotopic exchange processes

    The analysis of the heavy water production rate was carried out numerically for a heavy water production plant composed of the 3 stages bithermal H2/H2O-isotopic exchange columns of multisection separated-bed type and monothermal H2/H2O-isotopic exchange EXEL-finisher of the same type. The production rate was influenced by the isotopic exchange efficiency in the hydrophobic Pt-catalyst bed, ηc, and in the scrubbing bed, ηb, and by the water stream cut, θ1, from the first to the second stage and θ2 from the second to the third stage and θ3 from the third to the EXEL-finisher. Finally, the D-concentration profile in the EXEL-finisher was calculated under the standard conditions. (author)

  11. All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe2–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials

  12. Study of degranulation induced by injective excipients in a rat mast (RBL-2H3) cell line%常用注射用辅料刺激RBL-2H3细胞脱颗粒的作用

    关翠雯; 金晶; 李佳; 李萍; 邱玉文; 涂家生; 孙会敏; 黄芝瑛

    2012-01-01

    Objective To study directive effects of multiple kinds of injective excipients on the degranulalion in the RBL-2H3 rat mast cell line and to provide some indications for establishing a screening and evaluating method for pseudoallergy induced by injective excipients. Methods RBL-2H3 cells were cultured and treated with varying dose of injective excipients including Hydroxypropyl-β-cyclodexlrin (HP-β-CD) , Melhoxy pgly(ethylene glycol)-poly(D,L-lactide) 40/60 (mPEG-PDLLA40/60) , Tween80, Polyethylene glycol 400 (PEG400) , Polyethylene glycol 600 (FEG600) and Cremophor EL(CrEL). And then the amount of releasing β-hexosarninidase was delected. MTT assay was demonstrated to determine the cytotoxicity of injective excipients which causing RBL-2H3 cells degranulation. Results HP-β-CD, high concentration Tween80(3.0 mg/ml) and high concentration mPEC-PDLLA40/60(40mg/ml) induced RBL-2H3 cells degranulation in a concentration-dependent manner. Degranulation was not delected in cells treated with PEC400, PEC600 and CrCL. HP-β-CD showed cytotoxicity without concentration-dependent manner while mPEG-PDLLA 40/60 had no cytotoxicity. Tween80 showed low-toxiciry cytotoxicity in a concentration-dependent manner. Conclusion β-hexosaminidase release assay of RBL-2H3 cells ia effective and sensitive, and can be used for evaluating the anaphylactoid reaction caused by injective excipients. Cell degranulation induced by high concentration Tween80 may be due to its cylotoxicity.%目的 研究多种注射用辅料刺激肥大细胞RBL-2H3脱颗粒的作用,建立和完善注射用辅科引发类过敏反应的筛选评价体系.方法 以不同浓度的注射用辅料羟丙基-β-环糊精(HP-β-CD)、甲氧基聚乙二醇-聚乳酸共聚物40/60( mPEG-PDLLA40/60)、聚乙二醇400(PEG400)、聚乙二醇600 (PEG600)、聚氧乙烯蓖麻油(CrEL)和吐温80处理RBL-2H3细胞,测定β-氨基己糖苷酶释放率,并通过MTT法进一步研究有脱颗粒作用的受试物对RBL-2H3

  13. Muonium Addition Reactions and Kinetic Isotope Effects in the Gas Phase: k∞ Rate Constants for Mu + C2H2.

    Arseneau, Donald J; Garner, David M; Reid, Ivan D; Fleming, Donald G

    2015-07-16

    The kinetics of the addition reaction of muonium (Mu) to acetylene have been studied in the gas phase at N2 moderator pressures mainly from ∼800 to 1000 Torr and over the temperature range from 168 to 446 K, but also down to 200 Torr at 168 K and over a much higher range of pressures, from 10 to 44 bar at 295 K, demonstrating pressure-independent rate constants, kMu(T). Even at 200 Torr moderator pressure, the kinetics for Mu + C2H2 addition behave as if effectively in the high-pressure limit, giving k∞ = kMu due to depolarization of the muon spin in the MuC2H2 radical formed in the addition step. The rate constants kMu(T) exhibit modest Arrhenius curvature over the range of measured temperatures. Comparisons with data and with calculations for the corresponding H(D) + C2H2 addition reactions reveal a much faster rate for the Mu reaction at the lowest temperatures, by 2 orders of magnitude, in accord with the propensity of Mu to undergo quantum tunneling. Moreover, isotopic atom exchange, which contributes in a major way to the analogous D atom reaction, forming C2HD + H, is expected to be unimportant in the case of Mu addition, a consequence of the much higher zero-point energy and hence weaker C-Mu bond that would form, meaning that the present report of the Mu + C2H2 reaction is effectively the only experimental study of kinetic isotope effects in the high-pressure limit for H-atom addition to acetylene. PMID:25664674

  14. Inhibitory effect of tannins from galls of Carpinus tschonoskii on the degranulation of RBL-2H3 Cells

    Yamada, Parida; Ono, Takako; Shigemori, Hideyuki; Han, Junkyu; Isoda, Hiroko

    2012-01-01

    In this study, the anti-allergy potency of thirteen tannins isolated from the galls on buds of Carpinus tschonoskii (including two tannin derivatives) was investigated. RBL-2H3 (rat basophilic leukemia) cells were incubated with these compounds, and the release of β-hexosaminidase and cytotoxicity were measured. Of the thirteen tannins, tetragalloylglucose (2), pentagalloylglucose (3), casuarictin (4), and casuarinin (9) were the most potent inhibitors, and all the tannins showed no cytotoxic...

  15. Radical-controlled Oscillations in BrO3--fructose-Mn2+-H2SO4 System

    He Xing LI; Chun Hua GE

    2005-01-01

    Sustained oscillations were observed in the BrO3--fructose-Mn2+-H2SO4 system.Unlike the classical BZ oscillations, the present oscillations might be considered as radicalcontrolled rather than bromide-controlled since no substance subjected to bromination was present.Addition of acetone induced dual-frequency oscillations comprised of both the radical-controlled and the bromide-controlled oscillations.

  16. On the formation of cyclopentadiene in the C3H5˙ + C2H2 reaction

    Bouwman, J.; Bodi, A.; Oomens, J.; Hemberger, P.

    2015-01-01

    The reaction between the allyl radical (C3H5˙) and acetylene (C2H2) in a heated microtubular reactor has been studied at the VUV beamline of the Swiss Light Source. The reaction products are sampled from the reactor and identified by their photoion mass-selected threshold photoelectron spectra (ms-TPES) by means of imaging photoelectron photoion coincidence spectroscopy. Cyclopentadiene is identified as the sole reaction product by comparison of the measured photoelectron spectrum with that o...

  17. Regioselective synthesis of (E)-2-[2H or 3H]-5-succinimido-4-oxo-pent-2-enoic acid

    The synthesis of highly enriched C-2 deuteriated and tritiated (E)-5-succinimido-4-oxo-pent-2-enoic acid for use in enzymatic reduction is described. The starting materials 3-methoxycarbonyl-[3-2H]propionyl chloride and 3-methoxycarbonyl-[3-3H]propionyl chloride were prepared in high yield by regioselective deuteriation or tritiation of monomethyl succinate. The synthetic route involved regioselective bromination of 5-succinimidolaevulinic acid followed by dehydrobromination. (author)

  18. Herbivory responsive C2H2 zinc finger transcription factor protein StZFP2 from potato.

    Lawrence, Susan D; Novak, Nicole G; Jones, Richard W; Farrar, Robert R; Blackburn, Michael B

    2014-07-01

    While C2H2 zinc finger transcription factors (TF) are often regulated by abiotic stress, their role during insect infestation has been overlooked. This study demonstrates that the transcripts of the zinc finger transcription factors StZFP1 and StZFP2 are induced in potato (Solanum tuberosum L.) upon infestation by either the generalist tobacco hornworm (THW, Manduca sexta L.) or the specialist Colorado potato beetle (CPB, Leptinotarsa decemlineata Say). StZFP1 has been previously characterized as conferring salt tolerance to transgenic tobacco and its transcript is induced by Phytophthora infestans and several abiotic stresses. StZFP2 has not been characterized previously, but contains the hallmarks of a C2H2 zinc finger TF, with two conserved zinc finger domains and DLN motif, which encodes a transcriptional repressor domain. Expression studies demonstrate that StZFP2 transcript is also induced by tobacco hornworm and Colorado potato beetle. These observations expand the role of the C2H2 transcription factor in potato to include the response to chewing insect pests. PMID:24811678

  19. First steps towards a research on the kinetics of oxidation of B2H6 by atomic oxygen

    The objective of this work was to study the kinetics of oxidation of B2H6 by atomic oxygen. In this report preliminary work toward achieving this goal is presented. A detailed development of the research tools, while studying the oxidation kinetics of C2H6, was carried out. The kinetics of oxidation by atomic oxygen, much better known than the B2H6/O kinetics, was used as a tool for developing and testing the research meyhods. OH concentration as a function of oxidation time was measured. The measurements were conducted in a plug flow reactor, using the laser fluorescence diagnostic method. A model containing 51 elementary reactions describing the oxidation process was developed. The model simulations with minor parameters fit, yielded a very good agreement between the measurements and the calculations. The good fit obtained for a wide range of conditions, enhanches the reliability of the model and it is expected to be of a good predictive power for the entire oxidation process. (author)

  20. Permutationally invariant fitting of intermolecular potential energy surfaces: A case study of the Ne-C2H2 system

    Li, Jun; Guo, Hua

    2015-12-01

    The permutation invariant polynomial-neural network (PIP-NN) approach is extended to fit intermolecular potential energy surfaces (PESs). Specifically, three PESs were constructed for the Ne-C2H2 system. PES1 is a full nine-dimensional PIP-NN PES directly fitted to ˜42 000 ab initio points calculated at the level of CCSD(T)-F12a/cc-pCVTZ-F12, while the other two consist of the six-dimensional PES for C2H2 [H. Han, A. Li, and H. Guo, J. Chem. Phys. 141, 244312 (2014)] and an intermolecular PES represented in either the PIP (PES2) or PIP-NN (PES3) form. The comparison of fitting errors and their distributions, one-dimensional cuts and two-dimensional contour plots of the PESs, as well as classical trajectory collisional energy transfer dynamics calculations shows that the three PESs are very similar. We conclude that full-dimensional PESs for non-covalent interacting molecular systems can be constructed efficiently and accurately by the PIP-NN approach for both the constituent molecules and intermolecular parts.

  1. The phonon splitting and anisotropic effect of B2H6 molecular in the C2v minima

    Based on Jahn-Teller effect theory, quantum theory and group theory, the phonon splitting and anisotropic phenomena of the E ⊗e' system for B2H6 molecules with D3h symmetry are studied in the C2v minima. The vibration frequency of the system after Jahn-Teller distortion is calculated using the unitary shift transformation and modified scale transformation, it is found that the doubly degenerate vibration state e' is split into two states and its degeneration is completely lifted because of Jahn-Teller distortion. No matter which of the four C2v minima the system is in, the phonon splitting of the system is completely same. The Jahn-Teller distortion results in that the ground state of the system has lower energy after the distortion than before the distortion, B2H6 molecules will achieve a more stable state after the distortion just for the energy lessening. The phonon splitting is further discussed using group theory in this paper, the discussed results show that the vibration state e' of the system is split into two states respectively with a1 and b2 symmetries under the group C2v. The phonon splitting signifies that the isotropy of B2H6 molecules is destroyed and its anisotropy should appear. (authors)

  2. Metabolism of excess methionine in the liver of intact rat: an in vivo 2H NMR study

    L-Methionine is the most toxic amino acid if supplied in excess, and the metabolic basis for this toxicity has been extensively studied, with varying conclusions. It is demonstrated here that in vivo 2H NMR spectroscopy provides a useful approach to the study of the hepatic metabolism of methionine in the anesthetized rat. Resonances corresponding to administered L-[methyl-2H3]methionine, and to the transmethylation product sarcosine, are observed during the first 10-min period after an intravenous injection of the labeled methionine, and the time dependence has been followed for a period of 5 h. A third resonance, assigned to the N-trimethyl groups of carnitine, phosphorylcholine, and other metabolites, becomes observable several hours after administration of the deuteriated methionine. In addition, there is a small increase in the intensity of the HDO resonance over the period of the study, which is interpreted to reflect the ultimate oxidation of the labeled sarcosine methyl group via mitochondrial sarcosine dehydrogenase. Additional small 2H resonances assigned to N1-methylhistidine and creatine could be observed in perchloric acid extracts of the livers of rats treated with the deuteriated methionine. Inhibition of the flux through the transmethylation pathway is observed in the rat pretreated with the S-ethyl analogue of methionine, ethionine. These data provide strong support for the importance of glycine transmethylation in the catabolism of excess methionine

  3. Dual-bias STM study on adsorption configurations of C2H4 on a Ge(100) surface

    Using dual-bias scanning tunneling microscopy (STM), we investigated the adsorption of C2H4 on a Ge(100) surface at room temperature. We found two kinds of adsorption features in the STM images, one occupying one dimer and the other occupying two adjacent dimers in a dimer row. The high-resolution filled-state and empty-state images allowed us to convincingly identify the two STM features as a single C2H4 molecule adsorbed on top of a dimer and a pair of C2H4 molecules adsorbed across the ends of two adjacent dimers in the same dimer row (paired end-bridges), respectively. In particular, the empty-state STM images resolving the four protrusions of the two-dimer feature serve as unambiguous experimental evidence for the paired end-bridge configuration. The bias-voltage dependent STM contrast observed for both configurations was attributed to the difference in the polarizations of the charge densities over the molecules and the bare Ge dimers due to the electric-field.

  4. Effect of metformin therapy on 2-h post-glucose insulin levels in patients of polycystic ovarian syndrome

    Pikee Saxena

    2010-01-01

    Full Text Available Aims : To evaluate if 2-h post glucose insulin level is an effective tool to monitor insulin resistance in response to metformin therapy, in infertile women with polycystic ovarian syndrome (PCOS. Settings and Design : This prospective observational study was carried out in a tertiary care infertility clinic. Materials and Methods : 40 women with PCOS were categorized as having insulin resistance if fasting or 2-h post glucose insulin levels were >25 or >41μU/ml respectively. Post glucose insulin was compared before and after six months of metformin therapy along with other clinical, hormonal and metabolic parameters by using McNemar and the Student′s t-test. Results : Fasting insulin was elevated in 4 (10% and post-load insulin in 34 (85% patients; after metformin therapy respective values were 2 (5% and 16 (40%. Metformin therapy reduced post glucose insulin levels (P<0.001, improved the regularity of periods (P<0.001 and resulted in reduction of LH levels (P<0.001, total testosterone (P<0.001 and mean Body mass index (BMI (P=0.047. Metformin therapy did not alter waist-hip ratio and fasting insulin levels. Conclusion : 2-h post glucose insulin level is an effective tool to monitor insulin resistance in PCOS patients and improves significantly after metformin therapy, similar to improvements observed in clinical, hormonal and metabolic parameters.

  5. Effect of metformin therapy on 2-h post-glucose insulin levels in patients of polycystic ovarian syndrome

    Saxena, Pikee; Prakash, Anupam; Nigam, Aruna

    2010-01-01

    AIMS: To evaluate if 2-h post glucose insulin level is an effective tool to monitor insulin resistance in response to metformin therapy, in infertile women with polycystic ovarian syndrome (PCOS). SETTINGS AND DESIGN: This prospective observational study was carried out in a tertiary care infertility clinic. MATERIALS AND METHODS: 40 women with PCOS were categorized as having insulin resistance if fasting or 2-h post glucose insulin levels were >25 or >41μU/ml respectively. Post glucose insulin was compared before and after six months of metformin therapy along with other clinical, hormonal and metabolic parameters by using McNemar and the Student’s t-test. RESULTS: Fasting insulin was elevated in 4 (10%) and post-load insulin in 34 (85%) patients; after metformin therapy respective values were 2 (5%) and 16 (40%). Metformin therapy reduced post glucose insulin levels (P<0.001), improved the regularity of periods (P<0.001) and resulted in reduction of LH levels (P<0.001), total testosterone (P<0.001) and mean Body mass index (BMI) (P=0.047). Metformin therapy did not alter waist-hip ratio and fasting insulin levels. CONCLUSION: 2-h post glucose insulin level is an effective tool to monitor insulin resistance in PCOS patients and improves significantly after metformin therapy, similar to improvements observed in clinical, hormonal and metabolic parameters. PMID:21234175

  6. Measurement of the 2H(d ,p ) 3H reaction at astrophysical energies via the Trojan-horse method

    Li, Chengbo; Wen, Qungang; Fu, Yuanyong; Zhou, Jing; Zhou, Shuhua; Meng, Qiuying; Spitaleri, C.; Tumino, A.; Pizzone, R. G.; Lamia, L.

    2015-08-01

    The study of the 2H(d ,p ) 3H reaction is very important for the nucleosynthesis in both the standard Big Bang and stellar evolution, as well as for the future fusion reactor's planning of energy production. The 2H(d ,p ) 3H bare nucleus astrophysical S (E ) factor has been measured indirectly at energies from about 400 keV down to several keV by means of the Trojan-horse method applied to the quasifree process 2H(6Li ,p t ) 4He induced at a lithium beam energy of 9.5 MeV, which is closer to the zero-quasifree-energy point. An accurate analysis leads to the determination of the Sbare(0 ) =56.7 ±2.0 keV b and of the corresponding electron screening potential Ue=13.2 ±4.3 eV. In addition, this work gives an updated test for the Trojan-horse nucleus invariance by comparing with previous indirect investigations using the 3He=(d +p ) breakup.

  7. Measurements of hydrogen cyanide (HCN and acetylene (C2H2 from the Infrared Atmospheric Sounding Interferometer (IASI

    V. Duflot

    2013-04-01

    Full Text Available Hydrogen cyanide (HCN and acetylene (C2H2 are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. Because of their weak infrared absorption, overlapped by the CO2 Q branch near 720 cm−1, nadir sounders have up to now failed to measure these gases routinely. Taking into account CO2 line mixing, we provide for the first time extensive measurements of HCN and C2H2 total columns at Reunion Island (21° S, 55° E and Jungfraujoch (46° N, 8° E in 2009–2010 using observations from the Infrared Atmospheric Sounding Interferometer (IASI. A first order comparison with local ground-based Fourier transform infraRed (FTIR measurements has been carried out allowing tests of seasonal consistency which is reasonably captured, except for HCN at Jungfraujoch. The IASI data shows a greater tendency to high C2H2 values. We also examine a nonspecific biomass burning plume over austral Africa and show that the emission ratios with respect to CO agree with previously reported values.

  8. SONATINA-2H: a computer program for seismic analysis of the two-dimensional horizontal slice HTGR core

    A Computer program SONATINA-2H has been developed for predicting the behavior of a two-dimensional horizontal HTGR core under seismic excitation. SONATINA-2H is a general two-dimensional computer program capable of analyzing the horizontal slice HTGR core with the fixed side reflector blocks and its restraint structures and the core support structure. In the analytical model, each block is treated as a rigid body and represent one column of the reactor core and is connected to the core support structure by means of column springs and viscous dampers. A single dashpot model is used for the collision process between adjacent blocks. The core support structure is represented by a single block. The computer program SONATINA-2H is capable of analyzing the core behavior for an excitation input applied simultaneously in two mutually perpendicular horizontal directions. In the present report are given, the theoretical formulation of the analytical model, an user's manual to describe the input and output format and sample problems. (author)

  9. Photodetectors and birefringence in ZnP{sub 2}–S{sub 2h}{sup 5} crystals

    Stamov, I.G. [Tiraspol State Corporative University, Yablocicin Street 5, 2069 Tiraspol, Republic of Moldova (Moldova, Republic of); Syrbu, N.N., E-mail: sirbunn@yahoo.com [Technical University of Moldova, 168 Stefan cel Mare Avenue, 2004 Chisinau, Republic of Moldova (Moldova, Republic of); Dorogan, A.V. [Technical University of Moldova, 168 Stefan cel Mare Avenue, 2004 Chisinau, Republic of Moldova (Moldova, Republic of)

    2013-03-01

    The spectral dependences of refractive indexes n{sub o}(n{sup ⊥}), n{sub e}(n{sup ||}) and Δn=n{sub o}(n{sup ⊥})−n{sub e}(n{sup ||}) were studied in ZnP{sub 2}–C{sub 2h}{sup 5} crystals. The intersection of n{sub o}(n{sup ⊥}) and n{sub e}(n{sup ||}) was found for λ{sub 0}=0.906 μm. The crystal possesses positive dispersion Δn=n{sub o}(n{sup ⊥})−n{sub e}(n{sup ||}) in the region where λ>λ{sub 0}, and a negative dispersion is observed in the region where λ<λ{sub 0}. The electrical, spectral and azimuth characteristics of monolith n–r- and Me-n–r-ZnP{sub 2}C{sub 2h}{sup 5} and discrete ZnP{sub 2}–C{sub 2h}{sup 5–}ZnP{sub 2}–D{sub 4}{sup 8} structures were studied, and a prognosis was made on the usage perspective of these devices.

  10. Plasma Cleaning

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  11. Plasma technology

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  12. Plasma confinement

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  13. Plasma Diagnostics

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  14. Plasma Speaker

    Kovář, J

    2015-01-01

    The article describes the design and construction of one-channel plasma speaker. Absence of mechanical membrane gives the plasma speaker no frequency limitation. The design consists of power source to supply control electronic for signal modulation, converter and output transformer. Modulation of audio signal is realized by integrated circuit TL 594 that provides the PWM modulation. Duty cycle and frequency is adjusted by potentiometers. Dual forward converter is used to voltage amplification...

  15. Relationship between C2H2 reduction, H2 evolution and 15N2 fixation in root nodules of pea (Pisum sativum)

    Skøt, Leif

    1983-01-01

    after planting. After correction for H2 evolution in air, the factor (C2H2-H2)/N2 decreased to values near the theoretical value 3, or in one case to a value significantly (P <0.05) below 3. The proportion of the total electron flow through nitrogenase, which is not wasted in H2 production but used for...... N2 reduction, is often stated as the relative efficiency (1-H2/C2H2). This factor varied significantly (P <0.05) during the growth period. The actual allocation of electrons to H2 and N2, expressed as the H2/N2 ratio, was independent of plant age, however. This discrepancy and the observation that...... the (C2H2-H2)/N2 conversion factor tended to be lower than 3, suggests that the C2H2reduction assay underestimates the total electron flow through nitrogenase....

  16. Plasma turbulence

    This paper presents an overview of the progress made in understanding plasma turbulence. It has relied heavily on numerical simulations to gain some intuition on the physical processes underlying nonlinear interaction and as a cross check for quantitative estimates derived from weak turbulence theory or DIA-based strong turbulence theory. The mathematical description of plasmas, especially those confined in a magnetic bottle, is far more complex than the Navier-Stokes fluid. Yet because of the dispersion of the plasma eigenmodes, the DIA perhaps has greater validity in a plasma than in a Navier-Stokes fluid. Recent developments in dynamical-systems theory have not yet been implemented in plasma turbulence at the level discussed in other studies for boundary-layer turbulence. This technique has promise for evaluating the behavior of large eddies, which may dominate plasma transport as a low-order system. In the collisionless, kinetic regime, where turbulence in x, v phase space has to be addressed, the new methods involving noneigenmode entities called clumps and holes, need further evolution to gain complete acceptability. For the future, a combination of analytical tools and numerical methods may afford the optimum route. Some examples of this are revireviewed

  17. 2H-nuclear magnetic resonance investigations on phospholipid acyl chain order and dynamics in the gramicidin-induced hexagonal HII phase.

    Chupin, V.; Killian, J A; Kruijff, B. de

    1987-01-01

    The following results are reported in this paper: The interaction of gramicidin with [11,11-2H2]dioleoylphosphatidylcholine (DOPC) and [11,11-2H2]dioleoylphosphatidylethanolamine (DOPE) at different stages of hydration was studied by 2H- and 31P-nuclear magnetic resonance. In the L alpha phase in excess water the acyl chains of phosphatidylethanolamine (PE) are more ordered than phosphatidylcholine (PC) most likely as the result of the lower headgroup hydration of the former lipid. In excess ...

  18. Gas temperature effect on the time for onset of particle nucleation in argon diluted acetylene plasma

    Stefanovic, I; Berndt, J; Winter, J; Stefanovic, Ilija; Kovacevic, Eva; Berndt, Johannes; Winter, Jorg

    2004-01-01

    In our work we are focused on study of powder formation in C2H2/Ar plasmas. In this scope we used a combination of FTIR and mass spectroscopy, which are the mostly used experimental techniques for plasma powder formation diagnostics. To test the proposed mechanism for particle nucleation delay we measured the particle nucleation under different plasma conditions: firstly we increased the gas temperature and secondly we changed the background gas from argon to helium.

  19. Structure and composition of plasma deposited boron-containing carbon films

    Deposition of boron-carbon films on silicon, nickel, graphite, Kh18N10T steel from gas discharge plasma, the film chemical composition and erosion resistance to ion-plasma effects are studied. Conclusion is made on possibility of such film application as well coating for discharge chambers of thermonuclear facilities. Method of deposition from plasma makes it possible to avoid application of the previously used high-toxic and dangerously explosive B2H6

  20. Scientific Reports of Plasma Medicine and its Mechanism for Therapy in Plasma Bioscience Research Center

    Choi, Eun Ha

    2015-09-01

    Scientific reports of plasma medicine and its basic mechanism for therapy will be introduced, especially, performed in Plasma Bioscience Research Center, Korea. We have investigated enhanced anticancer effect of monocytes and macrophages activated by nonthermal plasma which act as immune-modulator on these immune cells. Further, we investigated the action of the nanosecond pulsed plasma activated media (NPPAM) on the lung cancer cells and its DNA oxidation pathway. We observed OD induced apoptosis on melanocytes G361 cancer cells through DNA damage signaling cascade. We also studied DNA oxidation by extracting DNA from treated cancer cell and analyzed the effects of OD/OH/D2O2/H2O2 on protein modification and oxidation. Additionally, we attempted molecular docking approaches to check the action of D2O2 on the apoptosis related genes.

  1. Plasma metallization

    Crowther, J M

    1997-01-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of s...

  2. Plasma properties

    The topics of active research in the calendar year 1989 included: RF induced plasma transport, not only for its effects on the mean particle distribution function but also as a means to enhance confinement of particles and to eliminate relatively cold alpha particle ash; thorough statistical analysis of tokamak data; improved neoclassical transport analysis; deeper analysis of two-fluid Braginskii transport in a tokamak; modelling of the plasma edge and wall interaction problem; reformulation of ballooning mode stability analysis in particularly strong and general terms; MHD modelling of tokamak phenomena, such as H-mode transition, and giant sawteeth, description of highly elongated tokamaks; and analysis of edge plasma RF antenna interactions. Our basic plasma physics studies include: statistical mechanics of Coulomb gases in bounded domains; theory of MHD instabilities with flow; numerical scheme for kinetic equations with nontrivial collision operators, and heat flow in particle simulations induced by discreteness effects. In addition, there is a modest space plasma physics effort funded by non-DOE sources. The studies of heating of the solar corona are strongly affected by work from the fusion program. Equally, work on ballooning modes led to work in magnetotail instabilities and additional solar corona heating mechanisms. We except to keep some research effort in this area. We do not include in this proposal plans for any new work in this field

  3. Effect of salinity on 2H/1H fractionation in lipids from continuous cultures of the coccolithophorid Emiliania huxleyi

    Sachs, Julian P.; Maloney, Ashley E.; Gregersen, Josh; Paschall, Christopher

    2016-09-01

    Salinity and temperature dictate the buoyancy of seawater, and by extension, ocean circulation and heat transport. Yet there remain few widely applicable proxies for salinity with the precision necessary to infer all but the largest hydrographic variations in the past. In the last decade the hydrogen isotope composition (2H/1H or δ2H) of microalgal lipids has been shown to increase systematically with salinity, providing a foundation for its use as a paleosalinity proxy. Culture and field studies have indicated a wide range of sensitivities for this response, ranging from about 0.6-3.3‰ ppt-1 depending on the lipid, location and/or culturing conditions. Lacking in these studies has been the controlled conditions necessary to isolate the response to salinity while keeping all other growth parameters constant. Here we show that the hydrogen isotope composition of lipids in the marine coccolithophorid Emiliania huxleyi grown in chemostats increased by 1.6 ± 0.3‰ ppt-1 (p fractionation factors on salinity yielded slopes of 1.2-2.2‰ ppt-1. This sensitivity of δ2Halkenone to salinity is 45-71% of that previously reported for E. huxleyi, which can be attributed to the fact that previous experiments were performed with batch cultures in which growth rates and other parameters differed between salinity treatments. The underlying cause of this response to salinity remains unknown, but may result from changes in (1) the proportion of lipid hydrogen derived from NADPH versus water, (2) the proportion of lipid hydrogen derived from NADPH from Photosystem I versus the oxidative pentose phosphate pathway (and other metabolic sources), or (3) the δ2H value of intracellular water.

  4. Mobile Column Measurements of HCHO, NO2, NH3, and C2H6 in Colorado during FRAPPE

    Kille, N.; Volkamer, R. M.; Baidar, S.; Ortega, I.; Sinreich, R.; Hannigan, J. W.; Cooper, O. R.; Nussbaumer, E.; Pfister, G.

    2015-12-01

    Gases from anthropogenic sources have the potential to have a profound impact on air quality. Emissions from large cattle feedlots and ONG (Oil and Natural Gas) sites are comprised of NH3 (ammonia) and C2H6 (ethane) as pollutants. C2H6 contributes to photochemical ozone (O3) production and oxidation production of HCHO (formaldehyde). NH3 is a major source for reactive nitrogen to form particulate matter 2.5, which negatively affects human health. NO2 (nitrogen dioxide), emitted during combustion, is considered a large-scale pollutant and contributes to the formation of O3. Deploying an innovative suite of remote sensing instruments in a mobile laboratory, a Multi Axis Differential Optical Absorption Spectrometer (MAX-DOAS), a UV-Vis Spectrometer, and a Fourier Transform Infrared Spectrometer, we obtain mobile column measurements at high spatial and temporal resolution, 2 seconds for the UV-Vis and IR spectrometers and 20 seconds for the MAX-DOAS. Within the scope of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) we measure total columns of HCHO, NO2, NH3, and C2H6 using the University of Colorado mobile laboratory. Emissions of urban areas, agriculture, and ONG sites were studied. For the measurement of total columns the solar occultation flux method has been applied. We measured significant variability in the columns. The measurement of total columns allows one to determine the emission flux and source strength when driving a closed box around or upwind and downwind of a source with the mobile laboratory. We present results from select research drives.

  5. Structure and stability of high pressure synthesized MgTM2H6 (TM = Zr, Nb) hydrides

    The structure of two isomorphous high pressure synthesized metal hydrides MgZr2H6 and MgNb2H6 is described in the R-3m space group with the hexagonal unit cells a = 3.3592(2) Å, c = 25.131(3) Å and a = 3.2901(9) Å, c = 23.09(1) Å, respectively (Z = 3). The metal atom structures were refined from powder XRD data, with Mg in the 3a site (0, 0, 0,) and Zr and Nb in the 6c site (0, 0, z) with the only refineable atomic parameter z = 0.225 and z = 0.220, respectively. As only a minute sample could be produced in the anvil cell, a conventional structural determination with neutron diffraction on a deuterated sample could not be made. Instead formation energies of the all proposed structural models were calculated using density functional theory (DFT) for accessing the most stable structure of the lowest energy level. The measured lattice parameters and the refined atomic positional parameters from the powder X-ray diffraction pattern were reproduced well by the DFT calculation. The hydrogen atoms were found to fully occupy an octahedral site coordinated by 3Mg and 3Zr atoms, a tetrahedral site coordinated by 4Zr atoms and another tetrahedral site coordinated by 3Mg and 1Zr atoms. Chemical, mechanical and dynamical stabilities of the MgZr2H6 structure were further discussed based on a chemical potential equilibrium diagram constructed from the calculated formation energies, calculated elastic constants and phonon spectra respectively. It is also shown that a high pressure increases the stability of the new hydrides

  6. Comparison of Cytotoxic and Antiproliferative Effects of Benzylidenecyclopentanone Analogues of Curcumin on RBL-2H3 Cells

    Agung Endro Nugroho

    2015-11-01

    Full Text Available Curcumin is a natural yellow pigment isolated from the rhizomes of Curcuma longa L. (turmeric, and has several pharmacological effects and no toxicity in both in animal and human clinical study. However, the problem of curcumin is its stability because of its active methylene moiety. Modification of this moiety to cyclopentanone is expected to increase the stability. Previous study reported that benzylidenecyclopentanone analogues of curcumin showed inhibitory effect on histamine release from RBL-2H3 (rat basophilic leukemia cells, a tumor analog of mast cells. One of them, the hydroxy-methoxy analog (PGV-0, showed more potent effect than that of curcumin. In the present study, some benzylidenecyclopentanone analogues of curcumin were evaluated for their effects on the viability and proliferation of RBL-2H3 cells. Viable cells were counted under a light microscope with a cells-counting chamber or using the cell viability reagent WST-1. The results showed that mast cell viability and histamine content were not affected by curcumin and benzylidene cyclopentanone for 30 min incubation, however, impaired for overnight incubation. The hydroxy-dimethyl benzylidene analog (PGV-1 strongly decreased the mast cells viability for overnight incubation, and its effect was highest among the other analogues. In the proliferation study, this compound also strongly inhibited the proliferation of mast cells, whereas curcumin and hydroxy-methoxy benzylidene analog inhibited the proliferation slightly. There were no inhibitory effects on mast cells proliferation treated by dibenzylidene; dihydroxybenzylidene; and hydroxy-diethylbenzylidene cyclopentanone.Keywords : viability, proliferation, curcumin, benzylidene cyclopentanone, RBL-2H3 cells

  7. Structural, vibrational and DFT studies on 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione

    Arjunan, V.; Saravanan, I.; Ravindran, P.; Mohan, S.

    2009-10-01

    The Fourier transform infrared (FTIR) and FT-Raman spectra of 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione have been measured in the range of 4000-400 and 4000-100 cm -1, respectively. Complete vibrational assignment and analysis of the fundamental modes of the compounds were performed using the observed FTIR and FT-Raman data. The geometry was optimised without any symmetry constraints using the DFT/B3LYP method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The vibrational frequencies determined experimentally are compared with those obtained theoretically from DFT gradient calculations employing the B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) methods for the optimised geometry of the compounds. The structural parameters and normal modes of vibration obtained from DFT method are in good agreement with the experimental data. The force fields obtained from DFT method were utilised and the potential energy distributions of all the fundamental vibrations of the compounds were calculated.

  8. Physical characterization and reactivity of the uranyl peroxide [UO2(η(2)-O2)(H2O)2]·2H2O: implications for storage of spent nuclear fuels.

    Mallon, Colm; Walshe, Aurora; Forster, Robert J; Keyes, Tia E; Baker, Robert J

    2012-08-01

    The unusual uranyl peroxide studtite, [UO(2)(η(2)-O(2))(H(2)O)(2)]·2H(2)O, is a phase alteration product of spent nuclear fuel and has been characterized by solid-state cyclic voltammetry. The voltammogram exhibits two reduction waves that have been assigned to the U(VI/V) redox couple at -0.74 V and to the U(V/IV) redox couple at -1.10 V. This potential shows some dependence upon the identity of the cation of the supporting electrolyte, where cations with larger ionic radii exhibit more cathodic reduction potentials. Raman spectroelectrochemistry indicated that exhaustive reduction at either potential result in a product that does not contain peroxide linkers and is likely to be UO(2). On the basis of the reduction potentials, the unusual behavior of neptunium in the presence of studtite can be rationalized. Furthermore, the oxidation of other species relevant to the long-term storage of nuclear fuel, namely, iodine and iodide, has been explored. The phase altered product should therefore be considered as electrochemically noninnocent. Radiotracer studies with (241)Am show that it does not interact with studtite so mobility will not be retarded in repositories. Finally, a large difference in band gap energies between studtite and its dehydrated congener metastudtite has been determined from the electronic absorption spectra. PMID:22813353

  9. Responsive Copolymer Brushes of Poly[(2-(Methacryloyloxy)Ethyl) Trimethylammonium Chloride] (PMETAC) and Poly((1) H,(1) H,(2) H,(2) H-Perfluorodecyl acrylate) (PPFDA) to Modulate Surface Wetting Properties.

    Politakos, Nikolaos; Azinas, Stavros; Moya, Sergio Enrique

    2016-04-01

    Polymer brushes have a large potential for controlling properties such as surface lubrication or wetting through facile functionalization. Polymer chemistry, chain density, and length impact on the wetting properties of brushes. This study explores the use of diblock copolymer brushes with different block length and spatial arrangement of the blocks to tune surface wettability. Block copolymer brushes of the polyelectrolyte [2-(methacryloyloxy)ethyl] trimethylammonium chloride (PMETAC) with a contact angle of 17° and a hydrophobic block of (1) H, (1) H, (2) H, (2) H-perfluorodecyl Acrylate (PPFDA) with a contact angle of 130° are synthesized by RAFT polymerization. By changing the sequence of polymerization either block is synthesized as top or bottom block. By varying the concentration of initiator the length of the blocks is varied. Contact angle values with intermediate values between 17° and 130° are measured. In addition, by changing solvent pH and in presence of a different salt the contact angle of the copolymer brushes can be fine tuned. Brushes are characterized by atomic force microscopy, Raman confocal microscopy, and X-ray photoelectron spectroscopy. PMID:26872001

  10. Ground-based solar absorption measurements of CH{sub 4}, CO, C{sub 2}H{sub 6}, C2H2 and HCN in the tropics

    Petersen, Anna K.; Warneke, Thorsten; Velasco, Voltaire; Notholt, Justus [Institute of Environmental Physics (IUP), University of Bremen (Germany); Schrems, Otto [Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven (Germany)

    2007-07-01

    The composition of the tropical atmosphere and its change is of significant importance for global climate. Currently large uncertainties in the budgets of many trace gases in the tropics exist, mainly due to a lack of measurements in the tropics. We have performed solar absorption Fourier Transform InfraRed measurements at Paramaribo, Suriname (5.83 N, 55.17 W) during four consecutive dry seasons, starting in autumn 2004. Currently these are the only remote sensing measurements performed in the inner-tropics over a longer time period. In the case of methane these measurements represent the only tropical ground-based remote sensing data of sufficient precision to validate satellite retrievals of CH4. Here we present first results on methane (CH{sub 4}) and trace gases related to biomass burning. Methane retrievals are compared with model simulations, satellite retrievals from SCIAMACHY and in situ data. In addition we investigate the pollution from biomass burning using CO, C{sub 2}H{sub 6}, C{sub 2}H{sub 2} and HCN. Backwardtrajectories and global fire maps were used to identify the origin of the polluted air masses. Correlations between the different gases are analysed and compared to literature data.

  11. Hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) into gypsum (CaSO 4·2H 2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight

    Boisvert, Jean-Philippe; Domenech, Marc; Foissy, Alain; Persello, Jacques; Mutin, Jean-Claude

    2000-12-01

    The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO 4·2H 2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner.

  12. Plasma dynamo

    Rincon, F; Schekochihin, A A; Valentini, F

    2015-01-01

    Magnetic fields pervade the entire Universe and, through their dynamical interactions with matter, affect the formation and evolution of astrophysical systems from cosmological to planetary scales. How primordial cosmological seed fields arose and were further amplified to $\\mu$Gauss levels reported in nearby galaxy clusters, near equipartition with kinetic energy of plasma motions and on scales of at least tens of kiloparsecs, is a major theoretical puzzle still largely unconstrained by observations. Extragalactic plasmas are weakly collisional (as opposed to collisional magnetohydrodynamic fluids), and whether magnetic-field growth and its sustainment through an efficient dynamo instability driven by chaotic motions is possible in such plasmas is not known. Fully kinetic numerical simulations of the Vlasov equation in a six-dimensional phase space necessary to answer this question have until recently remained beyond computational capabilities. Here, we show by means of such simulations that magnetic-field a...

  13. Ion-neutral reactions of C2H2N+ with hydrocarbons : relevant to Titan’s ionosphere

    Fathi, Pantea

    2015-01-01

    To provide some insights on the formation of long-chain carbon-nitrogen bearing ions in Titan’s atmosphere, laboratory measurements of ion-neutral reactions were conducted and results are presented in the following licentiate thesis. The product ions of the C2H2N+ reaction with saturated and unsaturated neutral hydrocarbons have been studied using guided ion beam mass spectrometer (GIB-MS). The data have been used to infer the product ion signal intensity dependences on pressure and collision...

  14. Copper(II)-Mediated Intermolecular C(sp(2))-H Amination of Benzamides with Electron-Rich Anilines.

    Singh, Bijaya Kumar; Polley, Arghya; Jana, Ranjan

    2016-05-20

    Despite significant progress, copper-catalyzed/mediated C-H amination reactions with electron-rich anilines remain an unsolved problem due to catalyst deactivation and deleterious side reactions. Herein, we report a copper(II)-mediated C(sp(2))-H amination of benzamides with electronically neutral or electron-rich anilines. A dramatic influence of silver(I) and tetrabutylammonium bromide was observed on the reaction outcome. The present protocol also demonstrates the synthesis of a number of nonsteroidal anti-inflammatory drugs. PMID:27148754

  15. Impact-induced chemisorption of C2H2 on diamond(0 0 1) surfaces: a molecular dynamics simulation

    This paper reports some new observations in studying the interaction between hyperthermal C2H2 and diamond (0 0 1)-2x1 surface at room temperature by means of molecular dynamics simulations with the many-body hydrocarbon potential. Six types of chemisorption configurations have been observed, some of these are reported for the first time. Also, we have observed threshold effect and hydrogen atom dissociation in the chemisorption processes. All these facts are expected to be useful in setting experimental condition in diamond synthesis

  16. First results of the isotopic study (18O, 2H, 3H) of the Douala Quaternary aquifer (Cameroon)

    The Quaternary sandy aquifer of the Douala sedimentary basin generally shows homogeneous isotopic abundances (18O, 2H, 3H) of water sampled at different depths.The large majority of these samples indicated a direct and fast infiltration of precipitation, without significant evaporation. This homogeneity can moreover be accentuated under the pumping effects, connecting various levels of the multilayer aquifer. These results show that pollution from the surface can quickly reach the deeper layers, and seems to corroborate those obtained on the basis of field measurements and chemical analyses. (author)

  17. Oxidation Properties of Nitrogen-Doped Silicon Films Deposited from Si2H6 and NH3

    Scheid, Emmanuel; Boyer, Pierre; Samitier, Josep; Hassani, Ahmed

    1994-03-01

    Si2H6/NH3 gas mixture was employed to obtain, by low-pressure chemical vapor deposition (LPCVD) at low temperature, nitrogen-doped silicon (NIDOS) films with various N/Si ratios. Thermal oxide was grown in dry oxygen at 900°C and 1100°C on NIDOS films. The result indicates that the nitrogen content of NIDOS films, assessed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), greatly influences their oxidation rate.

  18. Ejectile Polarization for $^2 H(e,e'\\vec p)n$ at GeV energies

    Jeschonnek, Sabine [The Ohio State Univ., Columbus, OH (United States); van Orden, Jay Wallace [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2010-01-01

    We perform a fully relativistic calculation of the $^2 H(e,e'\\vec p)n$ reaction in the impulse approximation employing the Gross equation to describe the deuteron ground state, and we use the SAID parametrization of the full NN scattering amplitude to describe the final state interactions (FSIs). The formalism for treating the ejectile polarization with a spin projection on an arbitrary axes is discussed. We show results for the six relevant asymmetries and discuss the role of spin-dependent FSI contributions.

  19. Crystal structure and characterization of a novel acentric imidazolium analog [C3N2H5+][Br

    Gągor, A.; Piecha, A.; Jakubas, R.; Miniewicz, A.

    2011-02-01

    A novel nonlinear optical crystal [C3N2H5+][Br] has been synthesized and characterized by a single-crystal X-ray diffraction, calorimetric, dilatometric and dielectric measurements. Above 200 K the crystal structure is polar, with symmetry R3. It consists of a highly disordered imidazolium cations and discrete Br anions. The compound reveals a first order phase transition at 199/201 K (cooling/heating cycle) which leads to the monoclinic centrosymmetric space group P21/m. The exceptionally large increment of dielectric permittivity accompaning the structure transformation is related to the freezing of cation motions and a significant rebuilding of the anionic substructure.

  20. Study of T-H isotope exchange between H2-H2O by Pt-C-PTFE hydrophobic catalyst

    The preparation of Pt-C-PTFE hydrophobic catalyst is described. The experiments of T-H isotope exchange between H2/H2O by Pt-C-PTFE hydrophobic catalyst were carried out at 30 deg C, 50 deg C and 75 deg C respectively. Within the limits (9.65-38.22) cm/s, catalystic activity increases with the increase of hydrogen flow rate. The catalystic activity at 50 deg C is optimum. The catalystic activity of this catalyst between gas-liquid is larger than that between gas-vapour. Mixture of the hydrophobic catalyst with hydrophilic filler in the bed can improve hydrogen isotope exchange

  1. First results of the isotopic study (18O, 2H, 3H) of the Douala Quaternary aquifer (Cameroon)

    The quaternary sandy aquifer of the Douala sedimentary basin generally indicates homogeneity in isotopic abundance (18O, 2H, 3H) of water sampled at different depths. The large majority of these samples indicated a direct and fast infiltration of the precipitations, without significant evaporation. This homogeneity can moreover be accentuated under the pumping effects, putting in communication various levels of the multilayer aquifer. These results show that pollution from the surface can quickly reach the deeper layers, and seems to corroborate those obtained on the basis of field measurements and chemical analyses. (author)

  2. Experimental study of exclusive $^2$H$(e,e^\\prime p)n$ reaction mechanisms at high $Q^2$

    Kim Egiyan; Gegham Asryan; Nerses Gevorgyan; Keith Griffioen; Jean Laget; Sebastian Kuhn; Gary Adams; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; Gerard Audit; Harutyun AVAKIAN; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; Steve Barrow; Vitaly Baturin; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Lukasz Blaszczyk; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Antoine Cazes; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Dieter Cords; Pietro Corvisiero; Donald Crabb; Volker Crede; John Cummings; Natalya Dashyan; Rita De Masi; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Haluk Denizli; Lawrence Dennis; Alexandre Deur; Kahanawita Dharmawardane; Richard Dickson; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Steven Dytman; Oleksandr Dzyubak; Hovanes Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; Paul Eugenio; Renee Fatemi; Gleb Fedotov; Gerald Feldman; Robert Feuerbach; Robert Fersch; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Michel Guidal; Matthieu Guillo; Hayko Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; Charles Hanretty; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; Narbe Kalantarians; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Zebulun Krahn; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Ji Li; Kenneth Livingston; Haiyun Lu; Marion MacCormick; Claude Marchand; Nikolai Markov; Paul Mattione; Simeon McAleer; Bryan McKinnon; John McNabb; Bernhard Mecking; Surik Mehrabyan; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Viktor Mokeev; Kei Moriya; Steven Morrow; Maryam Moteabbed; James Mueller; Edwin Munevar Espitia; Gordon Mutchler; Pawel Nadel-Turonski; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Grant O' Rielly; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Sergio Pereira; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Julian Salamanca; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Alexander Skabelin; Elton Smith; Lee Smith; Daniel Sober; Daria Sokhan; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Steffen Strauch; Mauro Taiuti; David Tedeschi; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2007-06-01

    The reaction {sup 2}H(e,e{prime} p)n has been studied with full kinematic coverage for photon virtuality 1.75 < 5.5 {approx} GeV{sup 2}. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (p{sub n} < 100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100 < 750 MeV/c proton-neutron rescattering dominates the cross section, while {Delta} production followed by the N{Delta} {yields} NN transition is the primary contribution at higher momenta.

  3. Zero-field NMR study on a spin glass: iron-doped 2H-niobium diselenide

    Spin echoes are used to study the 93Nb NQR in 2H-NbSe2Fe/sub x/. Measured are (intensity) x (temperature), and T/sub 1P/ (spin-lattice relaxation parameter) and T2 (spin-spin relaxation time) as a function of temperature. Data reveal dramatic differences between non-spin glass samples (x = 0, 0.25%, 1% and 5%) and spin glass samples (x = 8%, 10% and 12%). All of the NQR results and the model calculation of the correlation times of Fe spins are best described by the phase transition picture of spin glasses

  4. Experimental study of exclusive 2H(e,e(prime) p)n reaction mechanisms at high Q2

    The reaction 2H(e,e(prime) p)n has been studied with full kinematic coverage for photon virtuality 1.75 2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (pn < 100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100 < 750 MeV/c proton-neutron rescattering dominates the cross section, while Δ production followed by the NΔ → NN transition is the primary contribution at higher momenta

  5. Determination of Isotopic Abundance of 2H, 13C, 18O, and 37Cl in Biofield Energy Treated Dichlorophenol Isomers

    Mahendra Kumar Trivedi

    2015-01-01

    2,4-Dichlorophenol (2,4-DCP) and 2,6-dichlorophenol (2,6-DCP) are two isomers of dichlorophenols, have been used as preservative agents for wood, paints, vegetable fibers and as intermediates in the production of pharmaceuticals and dyes. The aim of the study was to evaluate the impact of biofield energy treatment on the isotopic abundance ratios of 2H/1H or 13C/12C, and 18O/16O or 37Cl/35Cl, in dichlorophenol isomers using gas chromatography-mass spectrometry (GC-MS). The 2,4- DCP and 2,6-DC...

  6. Experimental study of exclusive $^2$H$(e,e^\\prime p)n$ reaction mechanisms at high $Q^2$

    Egiyan, K S; Amaryan, M J; Ambrozewicz, P; Anefalos Pereira, S; Anghinolfi, M; Asryan, G; Audit, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Batourine, V; Battaglieri, M; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Boiarinov, S; Bouchigny, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Butuceanu, C; Bültmann, S; Calarco, J R; Careccia, S L; Carman, D S; Cazes, A; Chen, S; Cole, P L; Collins, P; Coltharp, P; Cords, D; Corvisiero, P; Crabb, D; Credé, V; Cummings, J P; Dashyan, N B; De Masi, R; De Sanctis, E; De Vita, R; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fatemi, R; Fedotov, G; Feldman, G; Fersch, R; Feuerbach, R J; Garçon, M; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gonenc, A; Gordon, C I O; Gothe, R W; Griffioen, K A; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Joo, K; Jüngst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kubarovski, V; Kuhn, S E; Kuleshov, S V; Kühn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Li, Ji; Livingston, K; Lu, H Y; MacCormick, M; Marchand, C; Markov, N; Mattione, P; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mehrabyan, S S; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Minehart, R C; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Müller, J; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O I; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Sabatie, F; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Shvedunov, N V; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A V; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Strauch, S; Taiuti, M; Tedeschi, D J; Thoma, U; Tkabladze, A; Tkachenko, S I; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

    2007-01-01

    The reaction $^2$H$(e,e^\\prime p)n$ has been studied with full kinematic coverage for photon virtuality $1.75

  7. Solvent 1H/2H isotopic effects in the reaction of the L-Tyrosine oxidation catalyzed by Tyrosinase

    Tyrosinase is well known catalyst in the oxidation of L-Tyrosine to L-DOPA and following oxidation of L-DOPA to dopachinone. The aim of communication is to present the results of studies on the solvent isotopic effects (SIE) in the above reactions for the 1H/2H in the 3',5' and 2',6' substituted tyrosine. Obtained dependence of the reaction rate on the substrate concentration were applied for optimization of the kinetic parameters, kcat and kcat/Km, in the Michaelis-Menten equation. As a result - better understanding of the L-DOPA creation can be achieved

  8. Ejectile Polarization for $^2 H(e,e'\\vec p)n$ at GeV energies

    Jeschonnek, Sabine

    2009-01-01

    We perform a fully relativistic calculation of the $^2 H(e,e'\\vec p)n$ reaction in the impulse approximation employing the Gross equation to describe the deuteron ground state, and we use the SAID parametrization of the full NN scattering amplitude to describe the final state interactions (FSIs). The formalism for treating the ejectile polarization with a spin projection on an arbitrary axes is discussed. We show results for the six relevant asymmetries and discuss the role of spin-dependent FSI contributions.

  9. Double and zero quantum filtered 2H NMR analysis of D2O in intervertebral disc tissue

    Ooms, Kristopher J.; Vega, Alexander J.; Polenova, Tatyana; Cannella, Marco; Marcolongo, Michele

    2015-09-01

    The analysis of double and zero quantum filtered 2H NMR spectra obtained from D2O perfused in the nucleus pulposus of human intervertebral disc tissue samples is reported. Fitting the spectra with a three-site model allows for residual quadrupolar couplings and T2 relaxation times to be measured. The analysis reveals changes in both the couplings and relaxation times as the tissue begins to show signs of degradation. The full analysis demonstrates that information about tissue hydration, water collagen interactions, and sample heterogeneity can be obtained and used to better understand the biochemical differences between healthy and degraded tissue.

  10. Spatial and temporal characteristics of 2H and 18O in the basin of Dongting Lake. Impact of monsoon precipitation

    Two water sampling campaigns were carried out in April and August 2012 to investigate the spatial and temporal characteristics of 2H and 18O in the basin of Dongting Lake and to further understand the interactions between precipitation, river water, lake water, and groundwater. Influenced by different monsoons, precipitation, river water, and lake water are enriched in isotopes in April but depleted in August. Stable isotopes of river water and lake water also have great spatial variations. Unlike river and lake water, groundwater has little seasonal isotopic variation, indicating that the transformation between surface water and groundwater is very slow. (author)

  11. A High-Performance WSe2 /h-BN Photodetector using a Triphenylphosphine (PPh3 )-Based n-Doping Technique.

    Jo, Seo-Hyeon; Kang, Dong-Ho; Shim, Jaewoo; Jeon, Jaeho; Jeon, Min Hwan; Yoo, Gwangwe; Kim, Jinok; Lee, Jaehyeong; Yeom, Geun Young; Lee, Sungjoo; Yu, Hyun-Yong; Choi, Changhwan; Park, Jin-Hong

    2016-06-01

    The effects of triphenylphosphine (PPh3 )-based n-doping and hexagonal boron nitride (h-BN) insertion on a tungsten diselenide (WSe2 ) photodetector are systematically studied, and a very high performance WSe2 /h-BN heterostucture-based photodetector is demonstrated with a record photoresponsivity (1.27 × 10(6) A W(-1) ) and temporal photoresponse (rise time: 2.8 ms, decay time: 20.8 ms) under 520 nm wavelength and 5 pW power laser illumination. PMID:27106134

  12. Infrared band extinctions and complex refractive indices of crystalline C2H2 and C4H2

    Khanna, R. K.; Ospina, Mario J.; Zhao, Guizhi

    1988-03-01

    Thermal IR absorption intensities are obtained for thin films of crystalline C2H2 and C4H2 at 70 K, and their n and k complex refractive indices are ascertained by separating true film absorption from interface reflection on the basis of an analysis of the transmission spectrum ratio for two sample thicknesses. This method significantly simplifies the n and k iteration process. The n and k values determined in the laboratory will in most cases reproduce a given sample thickness' observed transmission to within + or - 5 percent.

  13. 2,2′-(Propane-1,3-di­yl)bis­(2H-indazole)

    Ovalle, Saúl; Bernès, Sylvain; Pérez Rodríguez, Nancy; Elizondo Martínez, Perla

    2011-01-01

    The title mol­ecule, C17H16N4, is a bis-indazole crystallized in the rare 2H-tautomeric form. Indazole heterocycles are connected by a propane C3 chain, and the mol­ecule is placed on a general position, in contrast to the analogous compound with a central C2 ethane bridge, which was previously found to be placed on an inversion center in the same space group. In the title mol­ecule, indazole rings make a dihedral angle of 60.11 (7)°, and the bridging alkyl chain displays a trans conformation...

  14. Plasma properties

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  15. LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

    Saji, Viswanathan S; Song, Hyun-Kon

    2015-01-01

    Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures. PMID:26328435

  16. Plasma physics and engineering

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  17. ''Dusty plasmas''

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  18. 9- and 13-Hydroxy-octadecadienoic acids (9+13 HODE) are inversely related to granulocyte colony stimulating factor and IL-6 in runners after 2h running.

    Nieman, David C; Meaney, Mary Pat; John, Casey S; Knagge, Kevin J; Chen, Huiyuan

    2016-08-01

    This study utilized a pro-inflammatory exercise mode to explore potential linkages between increases in 9- and 13-hydroxy-octadecadienoic acid (9+13 HODE) and biomarkers for inflammation, oxidative stress, and muscle damage. Male (N=10) and female (N=10) runners ran at ∼70% VO2max for 1.5h followed by 30min of downhill running (-10%). Blood samples were taken pre-run and immediately-, 1-h-, and 24-h post-run, and analyzed for 9+13 HODE, F2-isoprostanes, six cytokines, C-reactive protein (CRP), creatine kinase (CK), and myoglobin (MYO). Gender groups performed at comparable relative heart rate and oxygen consumption levels during the 2-h run. All outcome measures increased post-run (time effects, P⩽0.001), with levels near pre-run levels by 24h except for CRP, CK, MYO, and delayed onset of muscle soreness (DOMS). Plasma 9+13 HODE increased 314±38.4% post-run (P<0.001), 77.3±15.8% 1-h post-run (P<0.001), and 40.6±16.4% 24-h post-exercise (P=0.024), and F2-isoprostanes increased 50.8±8.9% post-run (P<0.001) and 19.0±5.3% 1-h post-run (P=0.006). Post-run increases were comparable between genders for all outcomes except for 9+13 HODE (interaction effect, P=0.024, post-run tending higher in females), IL-10 (P=0.006, females lower), and DOMS (P=0.029, females lower). The pre-to-post-run increase in 9+13 HODEs was not related to other outcomes except for plasma granulocyte colony stimulating factor (GCSF) (r=-0.710, P<0.001) and IL-6 (r=-0.457, P=0.043). Within the context of this study, exercise-induced increases in 9+13 HODEs tended higher in females, and were not related to increases in F2-isoprostanes, muscle damage, or soreness. The negative relationships to GCSF and IL-6 suggest a linkage between 9+13 HODES and exercise-induced neutrophil chemotaxis, degranulation, and inflammation. PMID:27018002

  19. Master regulator for chondrogenesis, Sox9, regulates transcriptional activation of the endoplasmic reticulum stress transducer BBF2H7/CREB3L2 in chondrocytes.

    Hino, Kenta; Saito, Atsushi; Kido, Miori; Kanemoto, Soshi; Asada, Rie; Takai, Tomoko; Cui, Min; Cui, Xiang; Imaizumi, Kazunori

    2014-05-16

    The endoplasmic reticulum (ER) stress transducer, box B-binding factor 2 human homolog on chromosome 7 (BBF2H7), is a basic leucine zipper (bZIP) transmembrane transcription factor. This molecule is activated in response to ER stress during chondrogenesis. The activated BBF2H7 accelerates cartilage matrix protein secretion through the up-regulation of Sec23a, which is responsible for protein transport from the ER to the Golgi apparatus and is a target of BBF2H7. In the present study, we elucidated the mechanisms of the transcriptional activation of Bbf2h7 in chondrocytes. The transcription of Bbf2h7 is regulated by Sex determining region Y-related high-mobility group box 9 (Sox9), a critical factor for chondrocyte differentiation that facilitates the expression of one of the major cartilage matrix proteins Type II collagen (Col2), through binding to the Sox DNA-binding motif in the Bbf2h7 promoter. BBF2H7 is activated as a transcription factor in response to physiological ER stress caused by abundant synthesis of cartilage matrix proteins, and consequently regulates the secretion of cartilage matrix proteins. Taken together, our findings demonstrate novel regulatory mechanisms of Sox9 for controlling the secretion of cartilage matrix proteins through the activation of BBF2H7-Sec23a signaling during chondrogenesis. PMID:24711445

  20. Effect of Plasma Processing and Organosilane Modifications of Polyethylene on Aeromonas hydrophila Biofilm Formation

    Dorota Kregiel; Kamila Niedzielska

    2014-01-01

    The aim of our research was to study how the modifications of polyethylene—a material commonly used in medicine and water industry—influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy) propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimeth...

  1. Quantum Dynamics Scattering Study of AB+CDE Reactions: A Seven Dimensional Treatment for the H2+C2H Reaction

    Wang, Dunyou

    2003-01-01

    A time-dependent wave-packet approach is presented for the quantum dynamics study of the AB+CDE reaction system for zero total angular momentum. A seven-degree-of-freedom calculation is employed to study the chemical reaction of H2+C2H yields H + C2H2 by treating C2H as a linear molecule. Initial state selected reaction probabilities are presented for various initial ro-vibrational states. This study shows that vibrational excitation of H2 enhances the reaction probability, whereas the excitation of C2H has only a small effect on the reactivity. An integral cross section is also reported for the initial ground states of H2 and C2H. The theoretical and experimental results agree with each other very well when the calculated seven dimensional results are adjusted to account for the lower transition state barrier heights found in recent ab initio calculations.

  2. Theoretical study of radiative electron attachment to CN, C{sub 2}H, and C{sub 4}H radicals

    Douguet, Nicolas; Fonseca dos Santos, S.; Orel, Ann E. [Department of Chemical Engineering and Materials Science, University of California at Davis, Davis, California 95616 (United States); Raoult, Maurice; Dulieu, Olivier [Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS Cachan, bât. 505, Campus d’Orsay, 91405 Orsay Cedex (France); Kokoouline, Viatcheslav [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)

    2015-06-21

    A first-principle theoretical approach to study the process of radiative electron attachment is developed and applied to the negative molecular ions CN{sup −}, C{sub 4}H{sup −}, and C{sub 2}H{sup −}. Among these anions, the first two have already been observed in the interstellar space. Cross sections and rate coefficients for formation of these ions by direct radiative electron attachment to the corresponding neutral radicals are calculated. For the CN molecule, we also considered the indirect pathway, in which the electron is initially captured through non-Born-Oppenheimer coupling into a vibrationally resonant excited state of the anion, which then stabilizes by radiative decay. We have shown that the contribution of the indirect pathway to the formation of CN{sup −} is negligible in comparison to the direct mechanism. The obtained rate coefficients for the direct mechanism at 30 K are 7 × 10{sup −16} cm{sup 3}/s for CN{sup −}, 7 × 10{sup −17} cm{sup 3}/s for C{sub 2}H{sup −}, and 2 × 10{sup −16} cm{sup 3}/s for C{sub 4}H{sup −}. These rates weakly depend on temperature between 10 K and 100 K. The validity of our calculations is verified by comparing the present theoretical results with data from recent photodetachment experiments.

  3. Global isoscapes for δ18O and δ2H in precipitation: improved prediction using regionalized climatic regression models

    Terzer, S.; Wassenaar, L. I.; Araguás-Araguás, L. J.; Aggarwal, P. K.

    2013-11-01

    A regionalized cluster-based water isotope prediction (RCWIP) approach, based on the Global Network of Isotopes in Precipitation (GNIP), was demonstrated for the purposes of predicting point- and large-scale spatio-temporal patterns of the stable isotope composition (δ2H, δ18O) of precipitation around the world. Unlike earlier global domain and fixed regressor models, RCWIP predefined 36 climatic cluster domains and tested all model combinations from an array of climatic and spatial regressor variables to obtain the best predictive approach to each cluster domain, as indicated by root-mean-squared error (RMSE) and variogram analysis. Fuzzy membership fractions were thereafter used as the weights to seamlessly amalgamate results of the optimized climatic zone prediction models into a single predictive mapping product, such as global or regional amount-weighted mean annual, mean monthly, or growing-season δ18O/δ2H in precipitation. Comparative tests revealed the RCWIP approach outperformed classical global-fixed regression-interpolation-based models more than 67% of the time, and clearly improved upon predictive accuracy and precision. All RCWIP isotope mapping products are available as gridded GeoTIFF files from the IAEA website (www.iaea.org/water) and are for use in hydrology, climatology, food authenticity, ecology, and forensics.

  4. Global isoscapes for δ18O and δ2H in precipitation: improved prediction using regionalized climatic regression models

    S. Terzer

    2013-06-01

    Full Text Available A Regionalized Climatic Water Isotope Prediction (RCWIP approach, based on the Global Network for Isotopes in Precipitation (GNIP, was demonstrated for the purposes of predicting point- and large-scale spatiotemporal patterns of the stable isotope compositions of water (δ2H, δ18O in precipitation around the world. Unlike earlier global domain and fixed regressor models, RCWIP pre-defined thirty-six climatic cluster domains, and tested all model combinations from an array of climatic and spatial regressor variables to obtain the best predictive approach to each cluster domain, as indicated by RMSE and variogram analysis. Fuzzy membership fractions were thereafter used as the weights to seamlessly amalgamate results of the optimized climatic zone prediction models into a single predictive mapping product, such as global or regional amount-weighted mean annual, mean monthly or growing-season δ18O/δ2H in precipitation. Comparative tests revealed the RCWIP approach outperformed classical global-fixed regression-interpolation based models more than 67% of the time, and significantly improved upon predictive accuracy and precision. All RCWIP isotope mapping products are available as gridded GeoTIFF files from the IAEA website (www.iaea.org/water and are for use in hydrology, climatology, food authenticity, ecology, and forensics.

  5. Electrical properties and conduction mechanism of [C2H5NH3]2CuCl4 compound

    Mohamed, C. Ben; Karoui, K.; Jomni, F.; Guidara, K.; Rhaiem, A. Ben

    2015-02-01

    The [(C2H5)NH3]2CuCl4 compound was prepared and characterized by several technique: the X-ray powder diffraction confirms the purity of the synthetized compound, the differential scanning calorimetric show several phase transitions at 236 K, 330 K, 357 K and 371 K, the dialectical properties confirms the ferroelectric-paraelectric phase transition at 238 K, which is reported by V. Kapustianyk et al. (2007) [1]. The two semi-circles observed in the complex impedance identify the presence of the grain interior and grain boundary contributions to the electrical response in this material. The equivalent circuit is modeled by a combination series of two parallel RP-CPE circuits. The temperature dependence of the alternative current conductivity (σg) and direct current conductivity (σdc) confirm the observed transitions in the calorimetric study. The (AC) electrical conduction in [(C2H5)NH3]2CuCl4 was studied by two processes that can be attributed to a hopping transport mechanism: the non-overlapping small polaron tunneling (NSPT) model in phase III and the correlated barrier hopping (CBH) model in phases I, II, IV, V and VI.

  6. Structural characterization and ferroelectric ordering in (C3N2H5)5Sb2Br11

    A ferroelectric crystal (C3N2H5)5Sb2Br11 has been synthesized. The single crystal X-ray diffraction studies (at 300, 155, 138 and 121 K) show that it is built up of discrete corner-sharing bioctahedra Sb2Br115- and highly disordered imidazolium cations. The room temperature crystal structure has been determined as monoclinic, space group, P21/n with: a=9.139A, b=15.150A and c=13.969A and β=96.190. The crystal undergoes three solid-solid phase transitions: (tetragonal?)354/352P21/n(I↔II) discontinuous, P21/n145Pn(II↔III) continuous and Pn120/135Pn(III↔IV) discontinuous. The dielectric and pyroelectric measurements allow us to characterize the low temperature phases III and IV as ferroelectric with the Curie point at 145 K and the saturated spontaneous polarization value of the order of 1.8x10-3Cm-2 along the a-axis (135 K). The ferroelectric phase transition mechanism at 145 K is due to the dynamics of imidazolium cations. - Crystal packing down the a-axis in (C3N2H5)5Sb2Br11 in plane II at 155 K

  7. N$_2$H$^+$ and N$^{15}$NH$^+$ towards the prestellar core 16293E in L1689N

    Daniel, F; Pagani, L; Lique, F; Gérin, M; Lis, D C; Hily-Blant, P; Bacmann, A; Roueff, E

    2016-01-01

    Understanding the processes that could lead to enrichment of molecules in $^{15}$N atoms is of particular interest in order to shed light on the relatively large variations observed in the $^{14}$N/$^{15}$N ratio in various solar system environments. Currently, the sample of molecular clouds where $^{14}$N/$^{15}$N ratios have been measured is small and has to be enlarged in order to allow statistically significant studies. In particular, the N$_2$H$^+$ molecule currently shows the largest spread of $^{14}$N/$^{15}$N ratios in high-mass star forming regions. However, the $^{14}$N/$^{15}$N ratio in N$_2$H$^+$ was obtained in only two low-mass star forming regions (L1544 and B1b). The current work extends this sample to a third dark cloud. We targeted the 16293E prestellar core, where the N$^{15}$NH$^+$ $J$=1-0 line was detected. Using a model previously developed for the physical structure of the source, we solved the molecular excitation with a non-local radiative transfer code. For that purpose, we computed ...

  8. Benchmark of SCALE (SAS2H) isotopic predictions of depletion analyses for San Onofre PWR MOX fuel

    Hermann, O.W.

    2000-02-01

    The isotopic composition of mixed-oxide (MOX) fuel, fabricated with both uranium and plutonium, after discharge from reactors is of significant interest to the Fissile Materials Disposition Program. The validation of the SCALE (SAS2H) depletion code for use in the prediction of isotopic compositions of MOX fuel, similar to previous validation studies on uranium-only fueled reactors, has corresponding significance. The EEI-Westinghouse Plutonium Recycle Demonstration Program examined the use of MOX fuel in the San Onofre PWR, Unit 1, during cycles 2 and 3. Isotopic analyses of the MOX spent fuel were conducted on 13 actinides and {sup 148}Nd by either mass or alpha spectrometry. Six fuel pellet samples were taken from four different fuel pins of an irradiated MOX assembly. The measured actinide inventories from those samples has been used to benchmark SAS2H for MOX fuel applications. The average percentage differences in the code results compared with the measurement were {minus}0.9% for {sup 235}U and 5.2% for {sup 239}Pu. The differences for most of the isotopes were significantly larger than in the cases for uranium-only fueled reactors. In general, comparisons of code results with alpha spectrometer data had extreme differences, although the differences in the calculations compared with mass spectrometer analyses were not extremely larger than that of uranium-only fueled reactors. This benchmark study should be useful in estimating uncertainties of inventory, criticality and dose calculations of MOX spent fuel.

  9. Auto-inducing media for uniform isotope labeling of proteins with 15N, 13C and 2H

    Auto-inducing media for protein expression offer many advantages like robust reproducibility, high yields of soluble protein and much reduced workload. Here, an auto-inducing medium for uniform isotope labelling of proteins with 15N, 13C and/or 2H in E. coli is presented. So far, auto-inducing media have not found widespread application in the NMR field, because of the prohibitively high cost of labeled lactose, which is an essential ingredient of such media. Here, we propose using lactose that is only selectively labeled on the glucose moiety. It can be synthesized from inexpensive and readily available substrates: labeled glucose and unlabeled activated galactose. With this approach, uniformly isotope labeled proteins were expressed in unattended auto-inducing cultures with incorporation of 13C, 15N of 96.6 % and 2H, 15N of 98.8 %. With the present protocol, the NMR community could profit from the many advantages that auto-inducing media offer

  10. Total single electron captive cross sections for slow He2+-Ne and He2+ - H2 collisions

    Total cross sections for single electron capture in He2+-Ne collisions have been measured in the impact energy range of 260 to 2000 eV. Such data are not yet available in the literature. Our results were interpreted with a simple two state Landau-Zener theory. From the Landau-Zener formula with an empirical transition matrix element the maximum cross section is predicted at ion impact energy of 36.5 eV. The experimental cross section values follow the expected trend with impact energy, suggesting that they are in an energy range above the location of the maximum cross section. Using these measured total single electron capture cross sections for He2+-Ne, a calibration for total single electron capture cross sections for He2+-H2 collisions could be carried out. We note, e.g., that at an impact energy of 600 eV the single electron capture cross section for He2+-H2 collisions is only about 2 % of the one for Ne, i.e. of the order of 4x10-18 cm2 and therefore rather small

  11. 1H MAS, 13C CP/MAS, and 2H NMR spectra studies of piperidinium p-chlorobenzoate

    Anomalous H/D isotope effects were detected in the 1H MAS NMR spectra of piperidinium p-chlorobenzoate (C5H10NH 2+⋅ ClC6H4COO − ) upon deuterium substitution of hydrogen atoms which form two kinds of N-H⋯O H-bonds in the crystal; in contrast to these spectra, only slight chemical shifts were recorded in 13C CP/MAS NMR spectra. 2H NMR spectrum of the deuterated sample show quadrupole coupling constants of 148 and 108 kHz, and reveal that there are a few motions contributing to the electric-field modulation of the 2H nucleus. The 1H MAS NMR spectra of piperidinium p-chlrobenzoate-d16 (C5D10ND 2+⋅ ClC6D4COO − ) and -d14 (C5D10NH 2+⋅ ClC6D4COO − ) revealed that the change in the envelope is caused by chemical shifts of each signal upon deuteration. Calculations based on the density-functional-theory showed that the N-H distance along the crystallographic a-axis mainly contributes to the anomalous isotope effects on 1H MAS NMR envelopes.

  12. Impact of membrane characteristics on the performance and cycling of the Br-2-H-2 redox flow cell

    Tucker, MC; Cho, KT; Spingler, FB; Weber, AZ; Lin, GY

    2015-06-15

    The Br-2/H-2 redox flow cell shows promise as a high-power, low-cost energy storage device. In this paper, the effect of various aspects of material selection and processing of proton exchange membranes on the operation of the Br-2/H-2 redox flow cell is determined. Membrane properties have a significant impact on the performance and efficiency of the system. In particular, there is a tradeoff between conductivity and crossover, where conductivity limits system efficiency at high current density and crossover limits efficiency at low current density. The impact of thickness, pretreatment procedure, swelling state during cell assembly, equivalent weight, membrane reinforcement, and addition of a microporous separator layer on this tradeoff is assessed. NR212 (50 mu m) pretreated by soaking in 70 degrees C water is found to be optimal for the studied operating conditions. For this case, an energy efficiency of greater than 75% is achieved for current density up to 400 mA cm(-2), with a maximum obtainable energy efficiency of 88%. A cell with this membrane was cycled continuously for 3164 h. Membrane transport properties, including conductivity and bromine and water crossover, were found to decrease moderately upon cycling but remained higher than those for the as-received membrane. (C) 2015 Elsevier B.V. All rights reserved.

  13. Geostatistical Analysis of Spatial Isotope (δ18O, δ2H and 3H) Variability of Groundwater Across Morocco

    Environmental isotopes are increasingly being used for a variety of applications in the fields of the Earth's water cycle and climate change. This paper reports the first national level survey of δ18O, δ2H, 3H and 14C in groundwater across Morocco, including the analysis of the spatial distribution of stable (δ18O and δ2H) and radioactive (tritium and carbon-14) isotopes used to assess eleven groundwater basins distributed across Morocco. The interpolations were carried out using ESRI ArcGIS 9.2 with spatial analyst extension. The methods used are ordinary kriging inverse distance weighting (IDW). The maps showing the spatial variability of tritium and radiocarbon in the basins are used to visualize the presence of modern and old groundwater, while the stable isotope maps show that the age of groundwater, the type (shallow or deep groundwater), the distance of the basin from the sea (Atlantic and Mediterranean) and the altitude are the main factors influencing the isotopic composition of groundwater. Those thematic maps will provide a valuable contribution for sustainable groundwater management of resources for drinking water supplies, agriculture and industry, which is a prime concern in countries dominated by arid and semiarid climates such as Morocco. (author)

  14. Impact of membrane characteristics on the performance and cycling of the Br2-H2 redox flow cell

    Tucker, Michael C.; Cho, Kyu Taek; Spingler, Franz B.; Weber, Adam Z.; Lin, Guangyu

    2015-06-01

    The Br2/H2 redox flow cell shows promise as a high-power, low-cost energy storage device. In this paper, the effect of various aspects of material selection and processing of proton exchange membranes on the operation of the Br2/H2 redox flow cell is determined. Membrane properties have a significant impact on the performance and efficiency of the system. In particular, there is a tradeoff between conductivity and crossover, where conductivity limits system efficiency at high current density and crossover limits efficiency at low current density. The impact of thickness, pretreatment procedure, swelling state during cell assembly, equivalent weight, membrane reinforcement, and addition of a microporous separator layer on this tradeoff is assessed. NR212 (50 μm) pretreated by soaking in 70 °C water is found to be optimal for the studied operating conditions. For this case, an energy efficiency of greater than 75% is achieved for current density up to 400 mA cm-2, with a maximum obtainable energy efficiency of 88%. A cell with this membrane was cycled continuously for 3164 h. Membrane transport properties, including conductivity and bromine and water crossover, were found to decrease moderately upon cycling but remained higher than those for the as-received membrane.

  15. EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

    Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L2,3 white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

  16. Measurements of hydrogen cyanide (HCN and acetylene (C2H2 from the Infrared Atmospheric Sounding Interferometer (IASI

    C. Clerbaux

    2012-10-01

    Full Text Available Hydrogen cyanide (HCN and acetylene (C2H2 are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. Because of their weak infrared absorption, overlapped by the CO2 Q-branch near 720 cm−1, nadir sounders have up to now failed to measure these gases routinely. Taking into account CO2 line mixing we provide for the first time extensive measurements of HCN and C2H2 total columns at Reunion Island (21° S; 55° E and Jungfraujoch (46° N; 8° E in 2009–2010 using observations from the Infrared Atmospheric Sounding Interferometer (IASI. These are compared with local ground-based Fourier Transform InfraRed (FTIR measurements and we demonstrate that the seasonality is well captured, except for HCN at Jungfraujoch. We also examine a nonspecific biomass burning plume over austral Africa and show that the emission ratios with respect to CO agree with previously reported values.

  17. Affordable uniform isotope labeling with {sup 2}H, {sup 13}C and {sup 15}N in insect cells

    Sitarska, Agnieszka; Skora, Lukasz; Klopp, Julia; Roest, Susan; Fernández, César; Shrestha, Binesh; Gossert, Alvar D., E-mail: alvar.gossert@novartis.com [Novartis Institutes for BioMedical Research (Switzerland)

    2015-06-15

    For a wide range of proteins of high interest, the major obstacle for NMR studies is the lack of an affordable eukaryotic expression system for isotope labeling. Here, a simple and affordable protocol is presented to produce uniform labeled proteins in the most prevalent eukaryotic expression system for structural biology, namely Spodoptera frugiperda insect cells. Incorporation levels of 80 % can be achieved for {sup 15}N and {sup 13}C with yields comparable to expression in full media. For {sup 2}H,{sup 15}N and {sup 2}H,{sup 13}C,{sup 15}N labeling, incorporation is only slightly lower with 75 and 73 %, respectively, and yields are typically twofold reduced. The media were optimized for isotope incorporation, reproducibility, simplicity and cost. High isotope incorporation levels for all labeling patterns are achieved by using labeled algal amino acid extracts and exploiting well-known biochemical pathways. The final formulation consists of just five commercially available components, at costs 12-fold lower than labeling media from vendors. The approach was applied to several cytosolic and secreted target proteins.

  18. EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

    Espinosa-Magana, F., E-mail: francisco.espinosa@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Ochoa-Lara, M.T. [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Lovey, F. [Centro Atomico Bariloche, 8300 S.C. de Bariloche (Argentina); Flores-Zuniga, H. [Universidad Autonoma de Zacatecaa, Av. Lopez Velarde 801, Zacatecas, Zac. 98060 (Mexico); Rios-Jara, D. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, San luis Potosi, S.L.P. 78126 (Mexico)

    2010-01-01

    Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L{sub 2,3} white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

  19. Degradation of Pentachlorophenol in Aqueous Solution by the UV/ZrO 2 /H 2 O 2 Photocatalytic Process

    Mohammad Reza Samarghandi

    2015-12-01

    Full Text Available Pentachlorophenol (PCP, which is one of the resistant phenolic compounds, has been classified in the category of EPA’s priority pollutants due to its high toxicity and carcinogenic potential. Therefore, its removal from water and wastewater is very important. Various methods have been studied for removing the compound, among which advanced oxidation processes (AOPs have attracted much attention because of ease of application and high efficiency. Thus the aim of this study was to investigate the efficiency of the UV/ZrO2/H2O2 process, as an AOP, for PCP removal from aquatic environments. The effects of several parameters such as ultraviolet (UV exposure time, initial PCP concentration, pH, concentration of zirconium dioxide (ZrO2 nanoparticles, and H2O2 concentration were studied. Kinetics of the reaction was also detected. The concentration of the stated materials in the samples was determined using a spectrophotometer at 500 nm. The results showed that the highest efficiency (approximately 100% was reached at optimized conditions of pH 6, contact time of 30 minutes, initial PCP concentration of 20 mg/L, the nanoparticles concentration of 0.1 g/L and H2O2 concentration of 14.7 mM/L. Also, the process followed the first order kinetics reaction. The obtained results illustrated that the UV/ZrO2/H2O2 process has a high ability in removing PCP.

  20. Strain-induced giant second-harmonic generation in monolayered 2H-MoX2 (X = S, Se, Te)

    Rhim, S. H.; Kim, Yong Soo; Freeman, A. J.

    2015-12-01

    Dynamic second-order nonlinear susceptibilities, χ(2)(2 ω,ω,ω)≡χ(2)(ω) , are calculated here within a fully first-principles scheme for monolayered molybdenum dichalcogenides, 2H-MoX2 (X = S, Se, and Te). The absolute values of χ(2)(ω) across the three chalcogens critically depend on the band gap energies upon uniform strain, yielding the highest χ(2)(0 )˜140 pm/V for MoTe2 in the static limit. Under this uniform in-plane stress, 2H-MoX2 can undergo direct-to-indirect transition of band gaps, which in turn substantially affects χ(2)(ω) . The tunability of χ(2)(ω) by either compressive or tensile strain is demonstrated especially for two important experimental wavelengths, 1064 nm and 800 nm, where resonantly enhanced non-linear effects can be exploited: χ(2) of MoSe2 and MoTe2 approach ˜800 pm/V with -2% strain at 1064 nm.