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Sample records for br isotopes close

  1. Direct mass measurements of Ge, As, Se and Br isotopes close to the proton drip line

    Energy Technology Data Exchange (ETDEWEB)

    Lima, G.F.; Lepine-Szily, A. [Inst. de Fisica-Univ. de Sao Paulo, Sao Paulo, SP (Brazil); Audi, G.; Mittig, W.; Chartier, M.; Orr, N.A.; Lichtenthaeler, R.; Angelique, J.C.; Casandjian, J.M.; Cunsolo, A.; Donzeaud, C.; Foti, A.; Gillibert, A.; Lewitowicz, M.; Lukyanov, S.; Maccormick, M.; Morrissey, D.J.; Ostrowski, A.N.; Sherril, B.M.; Stephan, C.; Suomijarvi, T.; Tassan-Got, L.; Vieira, D.J.; Villari, A.C.C.; Wouters, J.M.

    2003-07-01

    The masses of neutron-deficient nuclei close to the proton-drip line are an important input for the rapid proton capture (rp)-process modeling above {sup 56}Ni. The direct measurement of the masses of neutron-deficient nuclei 32 {<=} Z {<=} 35 was undertaken at GANIL using the time-of-flight (TOF) technique. The masses of very exotic nuclides as {sup 66}As, {sup 68}Se and {sup 71}Br are reported for the first time and present final uncertainties of 0.8-1.5 x 10{sup -5}. The mass values in most cases agree well with the Audi-Wapstra predictions. (orig.)

  2. Simultaneous production of high-pure 76Br, 77Br and 79Kr using an isotope separator

    International Nuclear Information System (INIS)

    A production method of the bromine radioisotopes 76Br and 77Br in high radiochemical purity has been developed without using an isotopically enriched target, instead, their precursors 76Kr and 77Kr produced in a NaBr target by proton irradiation were mass-separated and implanted into Al foils together with 79Kr by means of a high-resolution isotope separator. The isotope separation efficiencies of the radiokryptons with a compact ECR ion source were found to be 15±2%. The 79Kr was recovered cryogenically from the Al foil heated, while 76Kr and 77Kr were allowed to decay for 14.6 h and 1.24 h, respectively during which the almost maximum growth of 76Br and 77Br occurred. A comparison was made between anion and cation exchange methods for chemical separation of the radiobromines from the Al foils. The recovery efficiencies were found to be almost identical between then, and better than 95%. (author)

  3. Dual isotope imaging with LaBr3:Ce crystal and H8500 PSPMT

    International Nuclear Information System (INIS)

    The introduction of Lanthanum Bromide crystal, characterized by a fast and high light emission, offers the possibility to improve both imaging spatial resolution and energy resolution in SPECT in the 80–300 kev energy range, without compromising detection efficiency. The expected performances may be limited if the crystal is used with a multi-anode PMT with Position Sensitive response due to the wide differences in the segmented anode pad gains, ranging from 2:1 to 10:1, . These characteristics may strongly deteriorate the overall energy resolution and, consequently, impair the detector imaging capability. For this reason, a 256 independent channel electronic read out was developed, based on an FPGA control, to individually read the charge on each anode. The electronics features a very low electronic noise ( 3:Ce crystal coupled to a 2 × 2 array SBA photocatode (38% QE) Hamamatsu H8500. An offline calibration procedure is also shown in order to compensate the anode gain variation and to exploit the LaBr3:Ce capabilities, obtaining on the whole detection area an 8.0–8.5% energy resolution at 140 kev. The high energy resolution performances of this gamma camera permitted to discriminate emissions from two different isotope ( Tc99m and Co57) with very close photon energy (140 and 122 kev respectively). This capability can be used to provide the gamma image with references coming from Co57 point sources (marker) fixed at known positions. These results confirm the LaBr3:Ce crystals as one of the most interesting for all single photon emission applications.

  4. The influences of molecule structure form the spectrum isotopic effect between 79BrF and 81BrF in the X1Σ+

    International Nuclear Information System (INIS)

    The dissociation limit of BrF in the X1Σ+ ground state are analysed with Atomic and Molecular Reaction Statics. The spectrum isotopic effect between 79BrF and 81BrF in the X1Σ+ are analysed with Herzberg's isotopic theory. Based on the analysis, the isotopic influence for the vibration energy levels and the molecular potential energy function as Murrell-Sorbie potential (MS potential) are discussed. The results show that the spectrum isotopic effect between 79BrF and 81BrF in the X1Σ+ is a kind of weak effect and are agreement with Herzberg's isotope theory, the deviation of low vibration level between experiment and Herzberg's isotope theory are small, for higher-order force constant f4 and higher-order spread coefficient a3, theoretical and experimental results have clearer differences, but the effect for the potential energy function is not obvious as the spread coefficient a3 is much smaller than a1 and a2, the overall impact on the potential energy function is not remarkable. (authors)

  5. LaBr3:Ce small FOV gamma camera with excellent energy resolution for multi-isotope imaging

    International Nuclear Information System (INIS)

    The simultaneous administration of radiopharmaceuticals labeled with more than one radioisotope is becoming of increasing interest in clinical practice. Because the photon energies of the utilized radioisotopes could be very close (less than 15% difference), a gamma camera with adequate energy resolution is required. The availability of scintillation crystals with high light yield, as lanthanum tri-bromide (LaBr3:Ce), is particularly appealing for these applications. In this work, a new small field of view gamma camera prototype is presented, based on a planar LaBr3:Ce scintillation crystal with surfaces treatment typical of spectrometric devices, in order to enhance energy resolution performances. The crystal has round shape and has been optically coupled with a position sensitive photomultiplier tube with high quantum efficiency. The presented gamma camera shows outstanding energy resolution results in the investigated energy range (32–662 keV). These relevant performances have been obtained through the application of uniformity correction on the raw data, necessary due to the presence of position sensitive phototube, characterized by a spread of anodic gain values. In spite of position linearity degradation at crystal edges, due to reflective treatment of surfaces, intrinsic spatial resolution values are satisfactory on the useful field of view.The characterization of the presented gamma camera, based on a continuous LaBr3:Ce scintillation crystal with reflective surfaces, indicates good performances in multi-isotope imaging due to the excellent energy resolution results, also in comparison with similar detectors

  6. Structure effects in the calculation of beta strength functions and half lives of Rb and Br isotopes

    International Nuclear Information System (INIS)

    The properties of beda delayed neutron emission of the precursors around mass 95 are investigated using spherical Shell Model plus pairing. The objective of this work is to find out the important parameters that effect these properties. The strength functions and half lives of both even and odd Rb and Br precursors are calculated in BCS quasi-particle theory as well as in Seniority Truncated Exact Diagonalization (STED) scheme. The calculated half lives from the two schemes are in close agreement with each other. STED gave much smoother overall trend which is in better agreement with experimental values. The calculations reveal that the so called 'odd decays' which depend in an essential way on the parent ground state configuration are of crucial importance in determining both half life, t/sub 1/2/ and delayed neutron emission probability, P/sub n/. Furthermore, it is shown that it is not possible to choose apriori global set for the single particle Shell model basis to predict the correct ground state configurations for both the odd and even nuclei. Instead, it is necessary to examine available experimental evidence in order to construct a more valid global set for single particle basis. The significant variations of the predicted half lives according to the different parent ground-state configuration choices, reveal the importance of nuclear structure effects in these isotopes. The calculated t/sub 1/2/ and P/sub n/ of Rb and Br precursors are presented, discussed and compared with experimental values

  7. Modeling study of vibrational photochemical isotope enrichment. [HBr + Cl/sub 2/; HCl + Br/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Badcock, C.C.; Hwang, W.C.; Kalsch, J.F.

    1978-09-29

    Chemical kinetic modeling studies of vibrational-photochemical isotope enrichment have been performed on two systems: Model (I), H/sup 79/Br(H/sup 81/Br) + Cl/sub 2/ and, Model (II), H/sup 37/Cl(H/sup 35/Cl) + Br. Pulsed laser excitation was modeled to the first excited vibrational level of H/sup 79/Br in Model I and the first and second excited vibrational levels of both HCl isotopes in Model II. These are prototype systems of exoergic (Model I) and endoergic (Model II) reactions. The effects on enrichment of varying the external parameters (pressure, laser intensity) and the internal parameters (rate constants for V-V exchange and excited-state reactions) were examined. Studies of these prototype systems indicate that a favorable reaction for enrichment, with isotopically-specific excitation and a significantly accelerated vibrationally-excited-state reaction should have the following properties: the reaction from v = 0 should be only moderately exoergic, and the most favorable coreactant should be a polyatomic species, such as alkyl radical. Direct excitation of the reacting vibrational level is at least an order of magnitude more favorable for enrichment than is population by energy transfer. Enrichment of the minor isotope by these processes is more effective than is major isotope enrichment. Within limits, increased laser intensity is beneficial. However, for sequential excitation of a second vibrational level, major isotope enrichment can be diminished by high populations of the first vibrational level.

  8. Vibrational, rotational, and isotopic dependence of CaBr X2 Σ spin-rotational and HFS parameters

    International Nuclear Information System (INIS)

    The previously published molecular-beam, laser-rf, double-resonance study of the rotational and isotopic dependences of the spin-rotational and hyperfine interactions in the v'' = 0, X2Σ state of CaBr is supplemented here with data for v''=1. The vibrational dependence of the parameters is now obtained. The results for CaBr are displayed along with analogous, previously published results for CaF and CaCl

  9. Development and design of a negative ion source half life measurement of isotopes I and Br produced in 235U (Nsub(th),F)

    International Nuclear Information System (INIS)

    An integrated negative surface ionization target ion source was developed for the Soreq On-Line Isotope Separator, which is especially efficient for bromine and iodine isotopes. In this work 87-90Br and 138-141I were identified by beta activity scans and half-lives of 86-89Br and 137-139I were measured. (H.K.)

  10. 79BrF和81BrF基态X1∑+光谱性质同位素效应对结构性质的影响%The influences ofmolecule structure fromthe spectrum isotopic effect between 79BrFand 81BrF in the X1Σ+

    Institute of Scientific and Technical Information of China (English)

    刘国跃; 韩彩霞

    2012-01-01

    The dissociation limit of BrF in the X1 Σ+ ground state are analysed with Atomic and Molecular Reaction Statics. The spectrum isotopic effect between "BrF and 81BrF in the X1 Σ+ are analysed with Herzberg's isotopic theory. Based on the analysis, the isotopic influence for the vibration energy levels and the molecular potential energy function as Murrell-Sorbie potential (MS potential) are discussed. The results show that the spectrum isotopic effect between "BrF and "BrF in the X1 Σ+ is a kind of weak effect and are agreement with Herzberg's isotope theory, the deviation of low vibration level between experiment and Herzberg's isotope theory are small, for higher-order force constant f4 and higher-order spread coefficient a3, theoretical and experimental results have clearer differences, but the effect for the potential energy function is not obvious as the spread coefficient a3 is much smaller than ax and a2, the overall impact on the potential energy function is not remarkable.%采用原子分子静力学的基本原理分析了BrF基态X1∑+的离解极限,采用Herzberg同位素理论分析了BrF基态X1∑+光谱数据的同位素效应,并以此为基础,分析了光谱数据的同位素效应对振动能级和分子势能函数(Murrell-Sorbie势即MS势)的影响.结果表明,79BrF和81BrF基态X1∑+的光谱数据的同位素效应是一种弱效应,与Herzberg同位素理论符合得很好,低振动能态的能级对理论预计的偏离很小,高阶力常数f4和高阶展开系数a3与实验结果有较大偏差,但由于a3本身比a1和a2小很多,结果对势能函数整体影响不大.

  11. Using Halogens (Cl, Br, F, I) and Stable Isotopes of Water (δ18O, δ2H) to Trace Hydrological and Biogeochemical Processes in Prairie Wetlands

    Science.gov (United States)

    Levy, Z. F.; Lu, Z.; Mills, C. T.; Goldhaber, M. B.; Rosenberry, D. O.; Mushet, D.; Siegel, D. I.; Fiorentino, A. J., II; Gade, M.; Spradlin, J.

    2014-12-01

    Prairie pothole wetlands are ubiquitous features of the Great Plains of North America, and important habitat for amphibians and migratory birds. The salinity of proximal wetlands varies highly due to groundwater-glacial till interactions, which influence wetland biota and associated ecosystem functions. Here we use halogens and stable isotopes of water to fingerprint hydrological and biogeochemical controls on salt cycling in a prairie wetland complex. We surveyed surface, well, and pore waters from a groundwater recharge wetland (T8) and more saline closed (P1) and open (P8) basin discharge wetlands in the Cottonwood Lake Study Area (ND) in August/October 2013 and May 2014. Halogen concentrations varied over a broad range throughout the study area (Cl = 2.2 to 170 mg/L, Br = 13 to 2000 μg/L, F = pond water (δ18O = -9.5 to -2.71 ‰) mixes with shallow groundwater in the top 0.6 m of fringing wetland soils and 1.2 m of the substrate in the center of P1. Our results suggest endogenous sources for Br and I within the prairie landscape that may be controlled by biological mechanisms or weathering of shale from glacial till.

  12. Spectroscopy of light Br and Rb isotopes. Onset of large quadrupole deformation

    International Nuclear Information System (INIS)

    Among the nuclei off the line of stability, the N ≅ Z = 34-40 region offers some very interesting and unique features: large quadrupole deformations, triaxiality, shape coexistence and transitions, and reductions of pairing correlations leading to rigid body rotation. The authors have performed over the last years at the University of Gottingen a systematic study of level energies and lifetimes of rotational bands in this mass region. In particular, they have investigated the effects which one or several aligned g/sub 9/2/ proton(s) or neutron(s) have on the collective parameters. They present here recent results in the odd-A proton nuclei Br and Rb

  13. Neon Isotope Fractionation in Ice Cores at Close-Off Depth

    Science.gov (United States)

    Liang, C.; Severinghaus, J. P.

    2015-12-01

    Analyzing trapped air bubbles in glacial ice is a well-established and useful method to reconstruct past atmospheric gas concentrations. However, trapped gas composition can be affected by fractionation during the closure of the air bubbles, complicating the reconstruction. Gases such as dioxygen (O2) and dihydrogen (H2) are known to leak out of the bubbles by permeation through the ice lattice at the close-off depth,where firn turns into ice. This process also can cause isotope fractionation, which obscures the past atmospheric isotope ratios in air bubbles in glacial ice. In order to establish the most accurate measurements of past atmospheric content, we need very detailed understanding of the permeation leakage mechanism in order to establish possible corrections. In this study, we propose the use of neon stable isotopes (neon-22 and neon-20) to place constraints on the mechanism of permeation leakage. Neon isotopes are an ideal system to explore because neon has a constant atmospheric isotope ratio, and thus only is affected by close-off fractionation. Neon permeation occurs via velocity-dependent hopping between sites within the ice lattice, because the neon atom is smaller than the critical size (3.6 Å) of the opening in the lattice. Theory predicts that neon isotope fractionation will occur due to the lower velocity of the heavier isotope, but this has never been experimentally verified and the theory is unable to quantitatively predict the magnitude of the fractionation. We will present the first results of high-precision neon isotope (22Ne/20Ne) measurements made in air pumped from the firm-to-ice transition in the Greenland Ice Sheet, where actively closing air bubbles drive permeation leakage. By measuring this natural neon isotope fractionation, we hope to learn about the mass dependence of the leakage mechanism and develop a more quantitative theory that is generalizable to biogeochemically- and climatically-active gases.

  14. Kinetic isotope studies of the gas-phase reaction (H,D,Mu) + HBr → (H,D,Mu)H + Br

    International Nuclear Information System (INIS)

    Reaction rate constants and kinetic isotope effects for the gas-phase reaction A + HBr → AH + Br, where A can be H, D, or Mu, have been studied using variational transition state theory with semiclassical tunneling on two semiempirical potential energy surfaces and a new ab initio surface. The rate constants and kinetic isotope effects are compared to experimental results. This comparison is used to test the potential energy surfaces, to determine which regions of the potential energy surface control the reaction rates and the kinetic isotope effects, and to learn whether or not any of the potential energy surfaces is accurate for a wide enough range of features to predict both the reaction rate constants and the kinetic isotope effects for this chemical system. (orig.)

  15. Reactor BR2

    International Nuclear Information System (INIS)

    The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported

  16. Hydrogeochemistry and stable isotopes of ground and surface waters from two adjacent closed basins, Atacama Desert, northern Chile

    Science.gov (United States)

    Alpers, C.N.; Whittemore, D.O.

    1990-01-01

    The geochemistry and stable isotopes of groundwaters, surface waters, and precipitation indicate different sources of some dissolved constituents, but a common source of recharge and other constituents in two adjacent closed basins in the Atacama Desert region of northern Chile (24??15???-24??45???S). Waters from artesian wells, trenches, and ephemeral streams in the Punta Negra Basin are characterized by concentrations of Na>Ca>Mg and Cl ???SO4, with TDS Mg ??? Ca and SO4 > Cl, with TDS also Mg ??? Ca and SO4 > Cl, but with TDS up to 40 g/l. The deep mine waters have pH between 3.2 and 3.9, and are high in dissolved CO2 (??13 C = -4.8%PDB), indicating probable interaction with oxidizing sulfides. The deep mine waters have ??18O values of ???-1.8%.compared with values < -3.5??? for other Hamburgo Basin waters; thus the mine waters may represent a mixture of meteoric waters with deeper "metamorphic" waters, which had interacted with rocks and exchanged oxygen isotopes at elevated temperatures. Alternatively, the deep mine waters may represent fossil meteoric waters which evolved isotopically along an evaporative trend starting from values quite depleted in ??18O and ??Dd relative to either precipitation or shallow groundwaters. High I/Br ratios in the Hamburgo Basin waters and La Escondida mine waters are consistent with regionally high I in surficial deposits in the Atacama Desert region and may represent dissolution of a wind-blown evaporite component. Rain and snow collected during June 1984, indicate systematic ??18O and ??D fractionation with increasing elevation between 3150 and 4180 m a.s.l. (-0.21??.??18O and -1.7??.??D per 100 m). Excluding the deep mine waters from La Escondida, the waters from the Hamburgo and Punta Negra Basins have similar ??D and ??18O values and together show a distinct evaporative trend (??D = 5.0 ??18O - 20.2). Snowmelt from the central Andes Cordillera to the east is the most likely source of recharge to both basins. Some of the

  17. Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China.

    Science.gov (United States)

    Li, Junxia; Wang, Yanxin; Xie, Xianjun

    2016-02-15

    In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000-10,000mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ(37)Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. PMID:26657361

  18. Search for isotopic signatures of a supernova explosion close to the solar system in marine sediments

    International Nuclear Information System (INIS)

    The recent observation of a 60Fe peak in a deep-sea ferro-manganese crust has been interpreted as due to a supernova explosion relatively close to the solar system 2.8 ± 0.4 Myr ago. To confirm this interpretation with better time-resolved measurements, and the simultaneous access, on the same sample, to other isotopes and geochemical phases, marine sediments seem to be a tool of choice. The objective of this work was to search for isotopic anomalies which would be characteristic for residues of this supernova. More specifically, 129I, 60Fe, and 26Al have been investigated, being measured by Accelerator Mass Spectrometry (AMS). Quantifying these nuclides' fluxes would help constrain stellar nucleosynthesis models. These residues are isotopes initially produced during hydrostatic and/or explosive nucleosynthesis. The physical conditions during the explosion (temperature, neutron density) are such that supernovae are thought to be good candidates for the astrophysical site of the r-process. The 129I study showed that measurement of pre-anthropogenic 129I/127I ratios need a very strict control of the various potential 129I sources, especially when working with small quantities (micrograms) of iodine. This study revealed that the expected pre-anthropogenic 129I/127I ratio for pre-nuclear samples in the marine environment shows a large discrepancy between theoretical calculations and experimental measurements. 60Fe and 26Al measurements allow us to conclude that, in the authigenic phase of the marine sediments, there is no 60Fe anomaly in the time interval defined by the signal found on the Fe-Mn crust (from 2.4 to 3.2 Myr), and no 26Al anomaly from 2.6 to 3.2 Myr. (author)

  19. Structural and energetic properties of closed shell XF(n) (X = Cl, Br, and I; n = 1-7) and XO(n)F(m) (X = Cl, Br, and I; n = 1-3; m = 0-6) molecules and ions leading to stability predictions for yet unknown compounds.

    Science.gov (United States)

    Thanthiriwatte, K Sahan; Vasiliu, Monica; Dixon, David A; Christe, Karl O

    2012-10-15

    Atomization energies at 0 K and heats of formation at 0 and 298 K were predicted for the closed shell compounds XF, XF(2)(-), XF(2)(+), XF(3), XF(4)(-), XF(4)(+), XF(5), XF(6)(-), XF(6)(+) (X = Cl and Br) and XO(+), XOF, XOF(2)(-), XOF(2)(+), XOF(3), XOF(4)(-), XOF(4)(+), XOF(5), XOF(6)(-), XO(2)(+), XO(2)F, XO(2)F(2)(-), XO(2)F(2)(+), XO(2)F(3), XO(2)F(4)(-), XO(3)(+), XO(3)F, XO(3)F(2)(-) (X = Cl, Br, and I) using a composite electronic structure approach based on coupled cluster CCSD(T) calculations extrapolated to the complete basis set limit with additional corrections. The calculated heats of formation are in good agreement with the available experimental data. The calculated heats of formation were used to predict fluoride affinities, fluorine cation affinities, and F(2) binding energies. On the basis of our results, BrOF(5) and BrO(2)F(3) are predicted to be stable against spontaneous loss of F(2) and should be able to be synthesized, whereas BrF(7), ClF(7), BrOF(6)(-), and ClOF(6)(-) are unstable by a very wide margin. The stability of ClOF(5) is a borderline case. Although its F(2) loss is predicted to be exothermic by 4.4 kcal/mol, it may have a sufficiently large barrier toward decomposition and be preparable. This situation would resemble ClO(2)F(3) which was successfully synthesized in spite of being unstable toward F(2) loss by 3.3 kcal/mol. On the other hand, the ClOF(4)(+) and BrOF(4)(+) cations are less likely to be preparable with F(2) loss exothermicities of -17.5 and -9.3 kcal/mol, respectively. On the basis of the F(-) affinities of ClOF (45.4 kcal/mol), BrOF (58.7 kcal/mol), and BrO(2)F(3) (65.7 kcal/mol) and their predicted stabilities against loss of F(2), the ClOF(2)(-), BrOF(2)(-), and BrO(2)F(4)(-) anions are excellent targets for synthesis. Our previous failure to prepare the ClO(2)F(4)(-) anion can be rationalized by the predicted high exothermicity of -17.4 kcal/mol for the loss of F(2). PMID:23009656

  20. Determination of the parameter ratio H02/K of closed thermal diffusion columns for polynary isotopic mixtures

    International Nuclear Information System (INIS)

    For the experimental determination of the H02/K ratio of the constants for prototype thermal diffusion columns from initial state mole fraction measurements there was a lack of sufficiently exact simple evaluation methods for polynary isotopic mixtures. The investigation of mole fraction changes at closed ends obtained by numerical integration of the corresponding system of second order partial differential equations resulted in a concept of approximation which allows to utilize approximative analytical solutions originally developed for binary isotopic mixtures. In the approximation the initial mole fractions are indirectly represented by the mean mass number of the initial mixture. Thus, the measured mole fraction changes can be attributed to the difference between the actual mass number of the components and the mean mass number of the enclosed mixture. By simple regression analysis a partial derivative can be obtained which can be attributed to the approximative analytical solutions for binary mixtures. (orig.)

  1. Neutron-rich In and Cd isotopes close to the doubly-magic $^{132}Sn$

    OpenAIRE

    Scherillo, A.; Genevey, J.; Pinston, J.A.; Covello, A; Faust, H.; Gargano, A.; R. Orlandi; Simpson, G.S.; Tsekhanovich, I.

    2005-01-01

    Microsecond isomers in the In and Cd isotopes, in the mass range A = 123 to 130, were investigated at the ILL reactor, Grenoble, using the LOHENGRIN mass spectrometer, through thermal-neutron induced fission reactions of Pu targets. The level schemes of the odd-mass $^{123-129}$In are reported. A shell-model study of the heaviest In and Cd nuclei was performed using a realistic interaction derived from the CD-Bonn nucleon-nucleon potential

  2. Expression of the Isotope Effects of Spectrum Data Between Au79 Br and Au81 Br in the Ground State X1Σ + and Their Performance of Structure Properties%Au79Br和 Au81Br基态 X1Σ+光谱数据的同位素效应在势能行为上的表现

    Institute of Scientific and Technical Information of China (English)

    刘国跃; 廖碧涛; 吴英

    2014-01-01

    采用原子与分子反应静力学的群论原理、微观过程的可逆性原理和能量最低原理分析了同位素分子Au79 Br和Au81 Br基态X1Σ+的对称性和离解极限;采用 Herzberg的同位素理论分析了AuBr分子基态X1Σ+主要光谱数据的同位素效应;分析探讨了光谱数据同位素效应对分子势能函数的影响。结果表明,正确的离解极限是确定同位素参数的重要依据,AuBr分子基态X1Σ+光谱数据的同位素效应是较弱的效应,对势能函数ECM势的二阶展开系数有一定的表现,三阶展开系数大大小于同位素理论的预计,导致排斥势有较大偏差,长程势尤其是渐近行为的效果与同位素理论的预计符合较好。%The symmetry and dissociation limit of Au79Br and Au81Br in the ground state X1Σ+ are analyzed with the group theory principle ,the principle of microreversibility and the minimum energy principle of a-tomic and molecular reaction statics .The isotope effects of the main spectrum data between Au79 Br and Au81 Br in the ground state X1Σ+ are analyzed using Herzberg's isotopic theory .Based on the above analy-ses ,the impacts of the structure properties from isotope effects of the spectrum data on molecular poten-tial energy function are discussed .The results show that the right dissociation limit is an important basis for the determination of isotope parameters ,that the isotope effect of spectral data for the Au79 Br and Au81 Br in the ground state X1Σ+ is relatively weak ,that to potential energy function (ECM potential) ,the sec-ond-order expansion coefficient show s some differences and the third-order expansion coefficient is signifi-cantly lower than the isotopic theory-based estimation ,resulting in obvious differences between the experi-ment and Herzberg's reject potential energy data ,and that their long-range potential ,especially their as-ymptotic behavior ,is in good agreement with the expectation of the

  3. Behaviour of the very high spin states in Er isotopes near the N=82 closed shell

    International Nuclear Information System (INIS)

    Though nuclei with a neutron number N>90 in the rare earth region exhibit a rotational behaviour up to spin approximately 60(h/2π), a different trend is observed for the neutron deficient erbium isotopes. In the spin window 30(h/2π)< I<65(h/2π), the associated continuum γ spectra exhibit two bumps of constant energy (approximately 650 keV and approximately 1400 keV respectively) for these very high spin values. These results are discussed in the framework of current models. (Auth.)

  4. The Influence of CO on the Carbon Isotopic Composition of CH4 in Closed Pyrolysis Experiment With Coal

    Institute of Scientific and Technical Information of China (English)

    刘全有; 刘文汇

    2004-01-01

    A low-mature coal (Ro=0.4%, from the Manjia'er depression, Tarim Basin, China) was subjected to closed system pyrolysis, in sealed gold tubes, under isothermal temperature conditions. The carbon isotopic compositions of the pyrolyst fractions (hydrocarbon, CO2, CO, etc.) at two temperature points (350°C and 550°C) were measured. The results showed that δ13CCH4 value is generally heavier at 350°C than that at 550°C, because the high abundance of CO generated at low temperature would greatly influence δ13CCH4 value, and the retention time of CO in gas chromatograph is close to that of CH4. But CO is formed through chemical reaction of the oxygen-containing functional group C=O, e.g. Lactones, ketones, ether, etc. At low temperature, while CO2 comes mainly from zecarboxylization.The carbon isotopic composition of coal gas from Lanzhou Coal Gas Works was definitely different from that of thermally pyrolysed products from coal. Theδ13CCH4 value of coal gas was abnormally heavier than δ13CCO. At the same time, the reversed sequence (δ13C-1>δ13C-2) of δ13C1 and δ13C2 happened. The bond energy of free ions generally decides the sequence of generation of hydrocarbon fractions according to the chemical structure, whereas the stability of pyrolysate fractions and their carbon isotope fractionation are affected by the C-C bond energy.

  5. Isotopic Differences between Forage Consumed by a Large Herbivore in Open, Closed, and Coastal Habitats: New Evidence from a Boreal Study System

    Science.gov (United States)

    Giroux, Marie-Andrée; Valiquette, Éliane; Tremblay, Jean-Pierre; Côté, Steeve D.

    2015-01-01

    Documenting habitat-related patterns in foraging behaviour at the individual level and over large temporal scales remains challenging for large herbivores. Stable isotope analysis could represent a valuable tool to quantify habitat-related foraging behaviour at the scale of individuals and over large temporal scales in forest dwelling large herbivores living in coastal environments, because the carbon (δ13C) or nitrogen (δ15N) isotopic signatures of forage can differ between open and closed habitats or between terrestrial and littoral forage, respectively. Here, we examined if we could detect isotopic differences between the different assemblages of forage taxa consumed by white-tailed deer that can be found in open, closed, supralittoral, and littoral habitats. We showed that δ13C of assemblages of forage taxa were 3.0‰ lower in closed than in open habitats, while δ15N were 2.0‰ and 7.4‰ higher in supralittoral and littoral habitats, respectively, than in terrestrial habitats. Stable isotope analysis may represent an additional technique for ecologists interested in quantifiying the consumption of terrestrial vs. marine autotrophs. Yet, given the relative isotopic proximity and the overlap between forage from open, closed, and supralittoral habitats, the next step would be to determine the potential to estimate their contribution to herbivore diet. PMID:26559186

  6. Phase diagram study of CaBr2-SrBr2 binary system

    International Nuclear Information System (INIS)

    Hydride ion conducting electrolytes are used in the electrochemical sensors for detecting hydrogen in liquid sodium coolant of fast reactors. In this connection several combinations of alkali/alkaline earth metal halides mixed with alkali/alkaline earth metal hydrides were investigated for using them as hydride ion conducting electrolytes. Currently, a mixture of CaBr2-CaH2 is used as the solid electrolyte in electrochemical sensors. With a view to develop and understand electrolyte characteristics of CaBr2-SrBr2-CaH2, system, the binary phase diagram of CaBr2-SrBr2 is being investigated in this work. Samples were prepared in dry argon atmosphere glove box using purified CaBr2 and SrBr2 salts covering the composition range of 0 to 100 mol% of CaBr2 in SrBr2 in steps of ∼10 mol%. Approximately 30 mg of samples were loaded inside hermetically closed iron capsules and were analysed by DTA under argon+4% hydrogen gas at controlled heating and cooling rates. Results have shown that the system shows appreciable terminal solid solution at both CaBr2 and SrBr2 rich sides. The system exhibits a eutectic reaction involving the terminal solid solutions at 553℃ and at ∼40 mol% CaBr2 in SrBr2. Further investigations are in progress. (author)

  7. Interaction in ternary HgBr2-BaBr2-CsBr system

    International Nuclear Information System (INIS)

    Series of polythermal sections in ternary HgBr2-BaBr2-CsBr system are investigated by the methods of physicochemical analysis. In double systems restricting ternary HgBr2-BaBr2-CsBr system formation of CsHg2Br5, CsHgBr3, Cs2HgBr4, CsBa2Br4 and CsBa2Br5 compounds is detected. Projection of liquidus surface of ternary HgBr2-BaBr2-CsBr system on triangle of compositions is plotted. This projection consists of eight fields of the primary crystallization of phases: HgBr2, BaBr2, CsBr, CsHgBr5, CsHgBr3, Cs2HgBr4, Cs2BaBr4 and CsBa2Br5. Coordinates of nonvariant points are determined

  8. BR2 Reactor: Introduction

    International Nuclear Information System (INIS)

    The irradiations in the BR2 reactor are in collaboration with or at the request of third parties such as the European Commission, the IAEA, research centres and utilities, reactor vendors or fuel manufacturers. The reactor also contributes significantly to the production of radioisotopes for medical and industrial applications, to neutron silicon doping for the semiconductor industry and to scientific irradiations for universities. Along the ongoing programmes on fuel and materials development, several new irradiation devices are in use or in design. Amongst others a loop providing enhanced cooling for novel materials testing reactor fuel, a device for high temperature gas cooled fuel as well as a rig for the irradiation of metallurgical samples in a Pb-Bi environment. A full scale 3-D heterogeneous model of BR2 is available. The model describes the real hyperbolic arrangement of the reactor and includes the detailed 3-D space dependent distribution of the isotopic fuel depletion in the fuel elements. The model is validated on the reactivity measurements of several tens of BR2 operation cycles. The accurate calculations of the axial and radial distributions of the poisoning of the beryllium matrix by 3He, 6Li and 3T are verified on the measured reactivity losses used to predict the reactivity behavior for the coming decades. The model calculates the main functionals in reactor physics like: conventional thermal and equivalent fission neutron fluxes, number of displacements per atom, fission rate, thermal power characteristics as heat flux and linear power density, neutron/gamma heating, determination of the fission energy deposited in fuel plates/rods, neutron multiplication factor and fuel burn-up. For each reactor irradiation project, a detailed geometry model of the experimental device and of its neighborhood is developed. Neutron fluxes are predicted within approximately 10 percent in comparison with the dosimetry measurements. Fission rate, heat flux and

  9. Preliminary isotopic study of groundwater salinity variations in the closed basin semiarid area of Los Monegros, Spain

    International Nuclear Information System (INIS)

    The Monegros II Irrigation Plan located in a semiarid, evaporite rich area of the Ebro (Ebre) river basin in northeastern Spain has given rise to serious environmental concern. Major potential environmental impacts include: soil and groundwater salinity problems, a change in the hydrological regime of playa lakes, and an increase of salinity in the Ebro river. The analysis and evaluation of these impacts require knowledge of the hydrogeology of the area. Natural groundwaters have high salinity, which generally increases with residence time as well as a result of groundwater evaporation in areas with a shallow water table. In order to gain insight into the groundwater flow and the sources of groundwater salinity, chemical and environmental isotopic surveys were carried out. Electrical conductivity logs show the existence of a sudden salinity increase with depth in some boreholes. The wide range of δ18O, δ2H and 3H values shows the dominance of local flow patterns with relatively short turnover times (from 10 to 100 years). Isotope fractioning evaporation in the unsaturated zone affects groundwater to some extent. The available data indicate the existence of a gypsum dissolution front in the unsaturated zone and point to a possible residual chloride front in the saturated zone. These fronts and the related water isotopic content are controlled in some cases by a clay seam. In other cases, however, they cannot be related to any lithological or hydrological features. (author). 9 refs, 8 figs

  10. Assessing groundwater recharge in an Andean closed basin using isotopic characterization and a rainfall-runoff model: Salar del Huasco basin, Chile

    Science.gov (United States)

    Uribe, Javier; Muñoz, José F.; Gironás, Jorge; Oyarzún, Ricardo; Aguirre, Evelyn; Aravena, Ramón

    2015-11-01

    Closed basins are catchments whose drainage networks converge to lakes, salt flats or alluvial plains. Salt flats in the closed basins in arid northern Chile are extremely important ecological niches. The Salar del Huasco, one of these salt flats located in the high plateau (Altiplano), is a Ramsar site located in a national park and is composed of a wetland ecosystem rich in biodiversity. The proper management of the groundwater, which is essential for the wetland function, requires accurate estimates of recharge in the Salar del Huasco basin. This study quantifies the spatio-temporal distribution of the recharge, through combined use of isotopic characterization of the different components of the water cycle and a rainfall-runoff model. The use of both methodologies aids the understanding of hydrological behavior of the basin and enabled estimation of a long-term average recharge of 22 mm/yr (i.e., 15 % of the annual rainfall). Recharge has a high spatial variability, controlled by the geological and hydrometeorological characteristics of the basin, and a high interannual variability, with values ranging from 18 to 26 mm/yr. The isotopic approach allowed not only the definition of the conceptual model used in the hydrological model, but also eliminated the possibility of a hydrogeological connection between the aquifer of the Salar del Huasco basin and the aquifer that feeds the springs of the nearby town of Pica. This potential connection has been an issue of great interest to agriculture and tourism activities in the region.

  11. Neutronic and Isotopic Simulation of a Thorium-TRU's fuel Closed Cycle in a Lead Cooled ADS

    International Nuclear Information System (INIS)

    The FACET group at CIEMAT is studying the properties and potentialities of several lead-cooled ADS designs for actinide and fission product transmutation. The main characteristics of these systems are the use of lead as primary coolant and moderator and fuels made by transuranics inside a thorium oxide matrix. The strategy assumed in this simulation implies that every discharge of the ADS will be reprocessed and would produce four waste streams: fission and activation products, remaining ''232 Th, produced ''233 U and remaining TRU's. The ''233 U is separated for other purposes; the remaining TRU are recovered altogether and mixed with the adequate amount of ''232 Th and fresh TRUs coming from LWR spent fuel. The simulations performed in this study have been focused primarily in the evolution of the fuel isotopic composition during and after each ADS burn-up cycle. (Author) 10 refs

  12. Spectra and energy levels of Br XXV, Br XXIX, Br XXX, and Br XXXI

    International Nuclear Information System (INIS)

    Emission lines of highly ionized bromine in the wavelength region 17-93 A have been identified in spectra recorded at the University of Rochester's OMEGA laser facility. The wavelengths of 2s-2p transitions in nitrogen-like Br XXIX, carbon-like Br XXX, and boron-like Br XXXI are presented. The wavelengths of the magnetic dipole transitions within the 2s22p3 ground configurations of Br XXIX are predicted from the experimental energy levels. Transitions from the n = 4 and 5 levels of sodium-like Br XXV were also identified, and the ionization energy of Br XXV was determined to be 9,023,800 +- 2 000cm-1 (1118.8 +- 0.2 eV)

  13. Foliar Stable Isotope Dynamics in a Closed-Canopy Tropical Forest: Towards a Better Understanding of Terrestrial Productivity in the Past

    Science.gov (United States)

    Graham, H. V.; Freeman, K. H.; Wing, S.

    2010-12-01

    Tropical forests with closed canopies today represent a large proportion (~40%) of global terrestrial biomass carbon, at least one-third of global soil carbon and 30-50% of terrestrial productivity. However, productivity of terrestrial habitats in the past is difficult to discern from the fossil record and the geologic history of three-dimensional forest structure remains unknown. This study seeks to identify isotopic and biochemical leaf characteristics that both signify a closed canopy forest and are preserved in the geologic record. The most charismatic feature of dense canopy forests is the extreme light gradient from canopy top to base, with as little as 1% of available light reaching the forest floor. Along this gradient, leaves exhibit strong light-dependent physiological responses and these adaptations are recorded in biochemical and anatomical leaf features. Using the canopy crane access system at Bosque San Lorenzo in Panamá we are able to sample leaves in the full diversity of light environments in a lowland, terre firme rainforest. As expected, bulk leaf material and individual plant waxes reveal a well-known pattern of vertical enrichment of carbon isotopes. This is generally attributed either to 13C-depleted carbon dioxide from respiration in the understory or to the increased photosynthetic rate typical of high light leaves. By comparing bulk leaf 13C to air samples captured in the same sampling locations we are able to contrast the effects of light with air 13C composition. Vertical gradients in the deuterium composition of leaf-water are associated with the evapotranspirative pattern of enrichment in high light leaves. We measured the D/H ratios of extracted n-alkanes to see if this relationship extends from leaf water to the geologically recalcitrant leaf wax lipids. The relationship between light environment and δDleaf as influenced by evapotranspiration can be constrained by measurement of the oxygen isotope ratio of α-cellulose, which

  14. A multi-layer, closed-loop system for continuous measurement of soil CO2 concentrations and its isotopic signature applied in a beech and a pine forest

    Science.gov (United States)

    Jochheim, Hubert; Wirth, Stephan

    2016-04-01

    We present a setup of measurement devices that allows the application of the soil CO2 gradient approach for CO2 efflux calculation in combination with the analysis of isotopic signature (δ13C). Vertical profiles of CO2 concentrations in air-filled pores of soil were measured using miniature NDIR sensors within a 16-channel closed-loop system where equilibrium with soil air can be achieved using hydrophobic, gas-permeable porous polypropylene tubes circulating gas using peristaltic pumps. A 16-position multiplexer allows the connection to an isotopic CO2 analyser. This setup was applied at two ICP Forest intensive monitoring sites, a beech and a pine forest on sandy soils located in Brandenburg, Germany. CO2 concentrations in air-filled pores of soils were measured on top of soil surface, below the humus layer, and in 10cm, 20cm, 30cm and 100 cm depths every 30 min. At both sites, soil moisture and temperature were measured continuously in the respective soil depths in identical time intervals. Isotopic signatures of soil CO2 was detected by measurement campaigns. After three years of measurements, our results provided evidence for distinct seasonal dynamics and vertical gradients of soil CO2 concentration and δ13C values. Varying impacts of soil temperature and moisture on CO2 concentration were revealed, highlighting its impact on soil physical and soil biological controls. Higher levels of CO2 concentration and a more distinct seasonal dynamics were detected at the beech site compared to the pine site. The collected data provide a suitable database for calculation of CO2 efflux and modelling of soil respiration.

  15. The BR eigenvalue algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Geist, G.A. [Oak Ridge National Lab., TN (United States). Computer Science and Mathematics Div.; Howell, G.W. [Florida Inst. of Tech., Melbourne, FL (United States). Dept. of Applied Mathematics; Watkins, D.S. [Washington State Univ., Pullman, WA (United States). Dept. of Pure and Applied Mathematics

    1997-11-01

    The BR algorithm, a new method for calculating the eigenvalues of an upper Hessenberg matrix, is introduced. It is a bulge-chasing algorithm like the QR algorithm, but, unlike the QR algorithm, it is well adapted to computing the eigenvalues of the narrowband, nearly tridiagonal matrices generated by the look-ahead Lanczos process. This paper describes the BR algorithm and gives numerical evidence that it works well in conjunction with the Lanczos process. On the biggest problems run so far, the BR algorithm beats the QR algorithm by a factor of 30--60 in computing time and a factor of over 100 in matrix storage space.

  16. 碰撞能和同位素取代对H+BrF→HBr+F反应立体动力学影响的理论研究%Influence of the collision energy and isotopic variant on the stereodynamics of reaction H + BrF→HBr + F

    Institute of Scientific and Technical Information of China (English)

    许燕; 赵娟; 王军; 刘芳; 孟庆田

    2010-01-01

    基于拟合得到的London-Eyring-Polanyi-Sato势能面,运用准经典轨线方法对H+BrF→HBr+F反应的立体动力学性质进行了理论研究.计算了反映矢量相关的角分布和对光诱导的双分子反应实验敏感的四个极化微分散射截面.结果表明:随着碰撞能的增加,产物的转动极化变强,并且产物的后向散射占主导地位.通过比较D+BrF→DBr+F和H+BrF→HBr+F反应的产物极化,揭示了明显的同位素效应.

  17. Preliminary results of the close-off depth and the stable isotopic records along a 109.91 m ice core from Dome A, Antarctica

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A 109.91 m ice core was recovered from Dome A (or Dome Argus), the highest ice feature in Antarctica, during the 2004/05 austral summer by the 21st Chinese National Antarctic Research Expedition (CHINARE-21). Both methane profile along the core and firn densification model calculation suggest that the close-off depth is at about 102.0 m with an ice age about 4200 a. Stable isotopes (δ18O and δD) of the chips samples produced during each run of ice core drilling at Dome A, together with those of the other cores recovered from the eastern inland Antarctica, suggest a relative stable climate with a temperature fluctuation amplitude about ±0.6℃ at the eastern inland Antarctica during the late Holocene. The average d-excess (or d =δ D-8δ 18O) of 17.1‰ along the Dome A core is probably the highest among the Antarctic inland ice cores, which may be resulted from the kinetic fractionation during the snow formation under an oversaturation condition. Moreover, the increasing trend of d-excess during the late Holocene reflects mainly the migration of the water source area for precipitation at Dome A towards low latitudes. This paper presents the first results of a shallow ice core recovered from the unexplored highest area of the Antarctic ice sheet, providing a background for the proposing deep ice core drilling at Dome A.

  18. Preliminary results of the close-off depth and the stable isotopic records along a 109.91 m ice core from Dome A, Antarctica

    Institute of Scientific and Technical Information of China (English)

    HOU ShuGui; LI YuanSheng; XIAO CunDe; PANG HongXi; XU JianZhong

    2009-01-01

    A 109.91 m ice core was recovered from Dome A (or Dome Argus), the highest ice feature in Antarctica,during the 2004/05 austral summer by the 21st Chinese National Antarctic Research Expedition (CHINARE-21). Both methane profile along the core and firn densification model calculation suggest that the close-off depth is at about 102.0 m with an ice age about 4200 a. Stable isotopes (δ~(18)O and δD) of the chips samples produced during each run of ice core drilling at Dome A, together with those of the other cores recovered from the eastern inland Antarctica, suggest a relative stable climate with a tem-perature fluctuation amplitude about ±0.6℃ at the eastern inland Antarctica during the late Holocene.The average d-excess (or d=δD-8δ~(18)O) of 17.1‰ along the Dome A core is probably the highest among the Antarctic inland ice cores, which may be resulted from the kinetic fractionation during the snow formation under an oversaturation condition. Moreover, the increasing trend of d-excess during the late Holocene reflects mainly the migration of the water source area for precipitation at Dome A towards low latitudes. This paper presents the first results of a shallow ice core recovered from the unexplored highest area of the Antarctic ice sheet, providing a background for the proposing deep ice core drilling at Dome A.

  19. Angular correlation for gamma-gamma transitions in 81Br and 83Br nuclei

    International Nuclear Information System (INIS)

    The directional angular correlation of coincident gamma transitions in 81Br and 83Br have been measured following the β- decay of 81Se(T sub(1/2) = 18.6 min) and 83Se(T sub(1/2) = 22.6 min) respectively, using Ge(Li) - high purity Ge and Ge(Li)-NaI(Tl) spectrometers. The radioactive sources were prepared by irradiating with neutrons in the IEA-R1 reactor, metallic selenium (natural) to produce 81Se and samples of metallic selenium enriched (to approx. 90% in 82Se) to produce 83Se. Measurements have been carried out for the gamma cascades 260-276 KeV, 290-276 KeV and 552-276 KeV in 81Br and the gamma cascades 225(510)-356 KeV, 510-356 KeV, 572-(510)-356 KeV, 718-(225)-(510)-356 KeV, 1064-356 KeV, 718-225 KeV, 718-(225)-510 KeV, 836-718 KeV, 718-(225)-866 KeV, 883-718 KeV and 1895-799 KeV in 83Br. The multipole mixing ratios, σ(E2/M1), were determined for 3 gamma transitions in 81Br and 11 gamma transitions in 83Br. In the case of 81Br present results confirmed some of the earlier results. The spin and parity assignment were made to the majority of levels in 81Br and 83Br involved in the present study, some of them confirming the earlier results. A comparison of some of the nuclear properties of the 79Br, 81Br and 83Br is made based on the available experimental data. The experimental results are also discussed qualitatively in terms of some nuclear models applicable for the description of the properties of odd-A bromine isotopes. (Author)

  20. Degradation of methyl bromide and methyl chloride in soil microcosms: Use of stable C isotope fractionation and stable isotope probing to identify reactions and the responsible microorganisms

    Science.gov (United States)

    Miller, L.G.; Warner, K.L.; Baesman, S.M.; Oremland, R.S.; McDonald, I.R.; Radajewski, S.; Murrell, J.C.

    2004-01-01

    Bacteria in soil microcosm experiments oxidized elevated levels of methyl chloride (MeCl) and methyl bromide (MeBr), the former compound more rapidly than the latter. MeBr was also removed by chemical reactions while MeCl was not. Chemical degradation dominated the early removal of MeBr and accounted for more than half of its total loss. Fractionation of stable carbon isotopes during chemical degradation of MeBr resulted in a kinetic isotope effect (KIE) of 59 ?? 7???. Soil bacterial oxidation dominated the later removal of MeBr and MeCl and was characterized by different KIEs for each compound. The KIE for MeBr oxidation was 69 ?? 9??? and the KIE for MeCl oxidation was 49 ?? 3???. Stable isotope probing revealed that different populations of soil bacteria assimilated added 13C-labeled MeBr and MeCl. The identity of the active MeBr and MeCl degrading bacteria in soil was determined by analysis of 16S rRNA gene sequences amplified from 13C-DNA fractions, which identified a number of sequences from organisms not previously thought to be involved in methyl halide degradation. These included Burkholderia , the major clone type in the 13C-MeBr fraction, and Rhodobacter, Lysobacter and Nocardioides the major clone types in the 13C-MeCl fraction. None of the 16S rRNA gene sequences for methyl halide oxidizing bacteria currently in culture (including Aminobacter strain IMB-1 isolated from fumigated soil) were identified. Functional gene clone types closely related to Aminobacter spp. were identified in libraries containing the sequences for the cmuA gene, which codes for the enzyme known to catalyze the initial step in the oxidation of MeBr and MeCl. The cmuA gene was limited to members of the alpha-Proteobacteria whereas the greater diversity demonstrated by the 16S rRNA gene may indicate that other enzymes catalyze methyl halide oxidation in different groups of bacteria. Copyright ?? 2004 Elsevier Ltd.

  1. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  2. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2002-04-01

    The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system.

  3. Reactor BR2. Introduction

    International Nuclear Information System (INIS)

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given

  4. BrO measurements over the Eastern North-Atlantic

    Directory of Open Access Journals (Sweden)

    M. Martin

    2009-04-01

    Full Text Available The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many was, e.g. since it catalytically destroys ozone, changes the NO2/NO-ratio as well as the OH/HO2-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere are not yet fully understood. <br>> We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN. Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7 ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from the African coast.

  5. BrO measurements over the Eastern North-Atlantic

    Directory of Open Access Journals (Sweden)

    U. Platt

    2009-12-01

    Full Text Available The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many ways, e.g. since it catalytically destroys ozone, changes the NO2/NO-ratio as well as the OH/HO2-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere is not yet fully understood. <br>> We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN. Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7 ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from there.

  6. Stable isotope trophic patterns in echinoderm megafauna in close proximity to and remote from Gulf of Mexico lower slope hydrocarbon seeps

    Science.gov (United States)

    Carney, Robert Spencer

    2010-11-01

    Hydrocarbon-seep communities in the Gulf of Mexico have a high biomass that is exploited as a food source to varying degrees by the photosynthesis-dependent fauna inhabiting the surrounding mud bottom. A decline concurrent with ocean depth in detritus influx to that background habitat results in a much lower background biomass. The biomass contrast between population-rich seeps and depauperate mud bottom leads to the prediction that seep utilization by the background fauna should be extensive at all depths and should increase with depth. Species depth zonation makes like-species comparisons over the full depth of the Gulf of Mexico impossible. Seeps and normal bottom above 1000 m have different fauna from those below 1000 m. Lower slope seeps are surrounded by a fauna rich in echinoderm species, especially asteroids, ophiuroids, and holothuroids. All three taxa have species that are abundant within seeps and are probably endemic to them. They also contain species found only in mud background or within mud and seeps backgrounds. Tissue analyses of δ13C and δ15N of echinoderms collected by ROV within seeps and trawling away from seeps indicate a pattern of utilization similar to that found in upper slope seeps exploited by different taxa. Seastar and ophiuroid species abundant in or endemic to seeps have tissue isotope values reflecting seep chemosynthetic input via a free-living microbial detritus or predation. A single seep-endemic deposit-feeding holothuroid showed distinct seep tissue values. Background deposit-feeding holothuroids collected within seeps showed either no or only minor incorporation of seep carbon, indicating either a lack of access to seep detritus or short feeding times within the seep. A predicted extensive utilization of seep productivity at the deeper seeps was not found. Seeps may be relatively closed systems that require special adaptations of species in order for them to enter, exploit, and survive. Alternately, the surrounding deep

  7. Effect of crystal transformation on 80Br retention in cadmium bromate

    International Nuclear Information System (INIS)

    Both the hydrated and anhydrous forms of cadmium bromate yield 15, 18 and 20 +- 1% initial retention of 80Br, sup(80m)Br and 82Br respectively. On heating at 1250C for 1 h the 80Br retention remains lower by approx. 20% than the identical values (approx. 50%) for sup(80m)Br and 82Br isotopes. The rate and the extent of annealing of the 80Br species during heat and radiation treatments are greater in the hydrated form and are further enhanced when structural rearrangement occurs following dehydration at 1250C. The associated activation energy is 0.09 eV below this temperature while it is 0.40 eV above, the latter value being identical with the activation energy for the dehydration process. (orig.)

  8. Experimental studies on BrO/Br ratios at Stromboli, Etna, Masaya, Gorely and Nyiragongo

    Science.gov (United States)

    Bobrowski, Nicole; Wittmer, Julian; Liotta, Marcello; Calabrese, Sergio; Giuffrida, Giovanni; Brusca, Lorenzo; Platt, Ulrich

    2014-05-01

    on the degassing of magmatic bodies inside the Earth. First results indicate that the BrO/SO2 ratio is close to a temporarily equilibrium already after only few minutes of the gas emission from the vent (e.g. Bobrowski and Giuffrida, 2012). This equilibrium seems to be relatively independent from meteorological parameters except for extreme conditions. We here present an empirical approach to answer the above question by discussing BrO formation studies from five different volcanoes, Stromboli and Etna (Italy), Masaya (Nicaragua), Gorely (Russia) and Nyiragongo (DR Congo). These volcanoes have a broad variation in their geological settings, surrounding environment and climate. They cover subduction related systems and rift volcanism and encompass climate zones from the subarctic to the tropics. For the BrO studies Multi-Axis-Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements have been carried out. Active alkaline traps were applied to determine bromine emissions at the crater rim. All measurements have been taken simultaneously or within a maximum time distance of a few hours. From these measurements we determined that a range of about 5 to 30 percent of the total bromine is transformed into BrO. We show and discuss how the varying BrO-Br partition is related partly to the geological settings, the various meteorological conditions and explore further possible influences. We will shortly discuss the current limitations of the commonly used measurement techniques itself and introduce possible future improvements.

  9. B and Li isotopes as intrinsic tracers for injection tests in aquifer storage and recovery systems

    International Nuclear Information System (INIS)

    Boron and Li isotopes have been tested as environmental tracers of treated sewage injected into a sandy aquifer (Shafdan reclamation project, Israel). During a 38 days injection test in a newly dug injection well, a conservative artificial tracer (Br-) was monitored together with δ11B and δ7Li in the injectate, in the unsaturated soil zone (porous cup) and an observation well in the aquifer. In spite of B and Li concentrations in the injectate close to background values, significant shifts of the isotope signatures could be observed over the duration of the injection test. Boron isotope ratios show a breakthrough curve delayed with respect to Br- breakthrough due to some reversible sorption on the aquifer material. No isotope fractionation was observed in the unsaturated or the saturated zone so that B isotopes can be considered as conservative in the investigated part of the aquifer system. Lithium isotopes are strongly fractionated, probably due to sorption processes. Lithium concentrations point to a Li sink in the system, δ7Li values vary strongly with a tendency of 7Li depletion in the liquid phase over the duration of the experiment. This is opposite to the expected preferential sorption of 6Li onto clay minerals. Boron isotopes reveals a valuable tracer of artificial recharge of freshwaters derived from treated sewage, both for short term tracer tests and for long-term monitoring of artificial recharge, even if in aquifers with higher clay contents, sorption-linked isotope fractionation cannot be excluded. More data are needed on Li isotope fractionation in natural groundwater systems to assess the potential of this tracer as monitoring tool.

  10. Pathways for the OH + Br2 → HOBr + Br and HOBr + Br → HBr + BrO Reactions.

    Science.gov (United States)

    Wang, Hongyan; Qiu, Yudong; Schaefer, Henry F

    2016-02-11

    The OH radical reaction with Br2 and the subsequent reaction HOBr + Br are of exceptional importance to atmospheric chemistry and environmental chemistry. The entrance complex, transition state, and exit complex for both reactions have been determined using the coupled-cluster method with single, double, and perturbative triple excitations CCSD(T) with correlation consistent basis sets up to size cc-pV5Z and cc-pV5Z-PP. Coupled cluster effects with full triples (CCSDT) and full quadruples (CCSDTQ) are explicitly investigated. Scalar relativistic effects, spin-orbit coupling, and zero-point vibrational energy corrections are evaluated. The results from the all-electron basis sets are compared with those from the effective core potential (ECP) pseudopotential (PP) basis sets. The results are consistent. The OH + Br2 reaction is predicted to be exothermic 4.1 ± 0.5 kcal/mol, compared to experiment, 3.9 ± 0.2 kcal/mol. The entrance complex HO···BrBr is bound by 2.2 ± 0.2 kcal/mol. The transition state lies similarly well below the reactants OH + Br2. The exit complex HOBr···Br is bound by 2.7 ± 0.6 kcal/mol relative to separated HOBr + Br. The endothermicity of the reaction HOBr + Br → HBr + BrO is 9.6 ± 0.7 kcal/mol, compared with experiment 8.7 ± 0.3 kcal/mol. For the more important reverse (exothermic) HBr + BrO reaction, the entrance complex BrO···HBr is bound by 1.8 ± 0.6 kcal/mol. The barrier for the HBr + BrO reaction is 6.8 ± 0.9 kcal/mol. The exit complex (Br···HOBr) for the HBr + BrO reaction is bound by 1.9 ± 0.2 kcal/mol with respect to the products HOBr + Br. PMID:26766412

  11. A new Approach to estimate Isotopic Ratios in Nuclear and Radiological Materials from Nuclear Spectrometric Measurements with Count Rates Close to Background.

    OpenAIRE

    Steiner, Martin; ZAEHRINGER Matthias; BERLIZOV Andriy; KIRCHNER Gerald

    2009-01-01

    Quantification and interpretation of isotopic ratios is generally acknowledged as a powerful method in nuclear forensic analyses to identify the origin of nuclear and radiological materials or the contamination source of environmental media. Nuclear spectrometric measurements provide a straightforward, relatively easy and fast technique for such analyses, which can even be performed on site for gamma emitting radioisotopes. However, radioisotopes relevant for nuclear forensic analyses ofte...

  12. Stable bromine isotopic composition of methyl bromide released from plant matter

    Science.gov (United States)

    Horst, Axel; Holmstrand, Henry; Andersson, Per; Thornton, Brett F.; Wishkerman, Asher; Keppler, Frank; Gustafsson, Örjan

    2014-01-01

    Methyl bromide (CH3Br) emitted from plants constitutes a natural source of bromine to the atmosphere, and is a component in the currently unbalanced global CH3Br budget. In the stratosphere, CH3Br contributes to ozone loss processes. Studies of stable isotope composition may reduce uncertainties in the atmospheric CH3Br budget, but require well-constrained isotope fingerprints of the source end members. Here we report the first measurements of stable bromine isotopes (δ81Br) in CH3Br from abiotic plant emissions. Incubations of both KBr-fortified pectin, a ubiquitous cell-stabilizing macromolecule, and of a natural halophyte (Salicornia fruticosa), yielded an enrichment factor (ε) of -2.00 ± 0.23‰ (1σ, n = 8) for pectin and -1.82 ± 0.02‰ (1σ, n = 4) for Salicornia (the relative amount of the heavier 81Br was decreased in CH3Br compared to the substrate salt). For short incubations, and up to 10% consumption of the salt substrate, this isotope effect was similar for temperatures from 30 up to 300 °C. For longer incubations of up to 90 h at 180 °C the δ81Br values increased from -2‰ to 0‰ for pectin and to -1‰ for Salicornia. These δ81Br source signatures of CH3Br formation from plant matter combine with similar data for carbon isotopes to facilitate multidimensional isotope diagnostics of the CH3Br budget.

  13. Complex approach to modelling of evolution of multi-recycled uranium isotope composition in closed fuel cycle of light water reactors

    International Nuclear Information System (INIS)

    Irradiated uranium fuel contains more then 90% of uranium, but at the present time the level of nuclear science and technology makes us mostly to postpone the using of recycling uranium up to far future or not at all. Only small number of states has the experience in using of recycling uranium and this experience is limited to one recycle. At the same time multiple recycling decreases the need in uranium mining and improves the utilization of uranium resources. Calculations result that in VVER-1000 irradiated fuel residual 235U concentration remains more than in natural uranium up to burnup level ∝ 60 MW.day/kg of heavy metals (h.m.). Utilization of reprocessed uranium as a source is more complicated due to 232U and 236U isotopes presenting in irradiated fuel. Some other uranium isotopes effect on the fuel reprocessing and fabrication is significantly less. 232U effect on neutron physical parameters is negligible due to very small concentration in reprocessed uranium. However introduction of this isotope may lead to an increase radiation dose rate to personnel because the hard gamma rays from its decay daughters. To limit this dose rate at the fuel fabrication plant 232U concentration in reprocessed uranium was restricted at the level 2.10-7 wt. %. Taking into account the enhanced technologies of fuel pin fabrication this restriction can become softer. 236U is a parasitic neutron absorber and to compensate this effect fuel with recycled uranium must be enriched more than that free from 236U. 234U concentration in reprocessed uranium is relatively small in comparison with 236U and need not compensation, but in the future this option can become necessary. (orig.)

  14. Temperature dependence of rate constants of the reactions Br(Br*)+IBr → Br2+I

    International Nuclear Information System (INIS)

    Rate constant and their temperature dependence in the range from -25 to +50 deg C for reactions Br(2P3/2)+IBr → Br2+I(2P2/3) and Br*(2P1/2)+IBr → Br2+I(2P3/2) have been measured by the method of laser atomic-resonance spectroscopy using radiation of iodine and bromine lasers. It has been detected that at 300 K the values of k1 and k2 agree with the known ones, meanwhile with the temperature growth both constants increase, moreover, for k2 the temperature dependence is much stronger. It is shown that the value of deceleration of the rate of reaction between Br atom and IBr in case of its spin-orbital excitation is the function of the temperature, decreasing with the temperature increase. 14 refs.; 3 figs.; 2 tabs

  15. Statistical clumped isotope signatures.

    Science.gov (United States)

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  16. Maximum abundant isotopes correlation

    International Nuclear Information System (INIS)

    The neutron excess of the most abundant isotopes of the element shows an overall linear dependence upon the neutron number for nuclei between neutron closed shells. This maximum abundant isotopes correlation supports the arguments for a common history of the elements during nucleosynthesis. (Auth.)

  17. Isotope effects in lattice dynamics

    International Nuclear Information System (INIS)

    The large number of available stable isotopes and well developed isotope separation technology have enabled growing crystals of C, LiH, ZnO, CuCl, CuBr, Cu2O, CdS, α-Sn, Ge, Si, etc. with a controlled isotope composition. Experimental and theoretical studies provide evidence that the isotope effect has an influence on the thermal, elastic, and vibrational properties of crystals. In this paper it is shown that in Ge and C crystals isotope effect causes only weak phonon scattering whereas in LiH the scattering potential changes are so strong that they lead to experimentally observable phonon localization. It is emphasized that a systematic description of isotope effects requires that anharmonicity be taken into account. (reviews of topical problems)

  18. Transition probabilities of Br II

    Science.gov (United States)

    Bengtson, R. D.; Miller, M. H.

    1976-01-01

    Absolute transition probabilities of the three most prominent visible Br II lines are measured in emission. Results compare well with Coulomb approximations and with line strengths extrapolated from trends in homologous atoms.

  19. Search for isotopic signatures of a supernova explosion close to the solar system in marine sediments; Recherche de signatures isotopiques dans les sediments marins de l'explosion d'une supernova proche du systeme solaire

    Energy Technology Data Exchange (ETDEWEB)

    Fitoussi, Caroline [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, (CSNSM) IN2P3/CNRS, Campus d' Orsay, Bat 108, 91405 Orsay (France)

    2006-06-15

    The recent observation of a {sup 60}Fe peak in a deep-sea ferro-manganese crust has been interpreted as due to a supernova explosion relatively close to the solar system 2.8 {+-} 0.4 Myr ago. To confirm this interpretation with better time-resolved measurements, and the simultaneous access, on the same sample, to other isotopes and geochemical phases, marine sediments seem to be a tool of choice. The objective of this work was to search for isotopic anomalies which would be characteristic for residues of this supernova. More specifically, {sup 129}I, {sup 60}Fe, and {sup 26}Al have been investigated, being measured by Accelerator Mass Spectrometry (AMS). Quantifying these nuclides' fluxes would help constrain stellar nucleosynthesis models. These residues are isotopes initially produced during hydrostatic and/or explosive nucleosynthesis. The physical conditions during the explosion (temperature, neutron density) are such that supernovae are thought to be good candidates for the astrophysical site of the r-process. The {sup 129}I study showed that measurement of pre-anthropogenic {sup 129}I/{sup 127}I ratios need a very strict control of the various potential {sup 129}I sources, especially when working with small quantities (micrograms) of iodine. This study revealed that the expected pre-anthropogenic {sup 129}I/{sup 127}I ratio for pre-nuclear samples in the marine environment shows a large discrepancy between theoretical calculations and experimental measurements. {sup 60}Fe and {sup 26}Al measurements allow us to conclude that, in the authigenic phase of the marine sediments, there is no {sup 60}Fe anomaly in the time interval defined by the signal found on the Fe-Mn crust (from 2.4 to 3.2 Myr), and no {sup 26}Al anomaly from 2.6 to 3.2 Myr. (author)

  20. A multi-layer, closed-loop system for continuous measurement of CO2 concentrations and its isotopic signature in forest soils as a basis for CO2 efflux calculation and for revealing its controls

    Science.gov (United States)

    Jochheim, Hubert; Wirth, Stephan

    2015-04-01

    We present a setup of measurement devices that allows the application of the soil CO2 gradient approach for CO2 efflux calculation in combination with the analysis of isotopic signature (δ13C). Vertical profiles of CO2 concentrations in air-filled pores of soil were measured using miniature NDIR sensors within a 16-channel closed-loop system where equilibrium with soil air can be achieved using hydrophobic, gas-permeable porous polypropylene tubes circulating gas using peristaltic pumps. A 16-position multiplexer allows the connection to an isotopic CO2 analyser. This setup was applied at two ICP Forest intensive monitoring sites, a beech and a pine forest on sandy soils located in Brandenburg, Germany. CO2 concentrations in air-filled pores of soils were measured on top of soil surface, below the humus layer, and in 10cm, 20cm, 30cm and 100 cm depths every 30 min. At both sites, soil moisture and temperature were measured continuously in the respective soil depths in identical time intervals. Isotopic signatures of soil CO2 was detected by measurement campaigns. After two years of measurements, our results provided evidence for distinct seasonal dynamics and vertical gradients of soil CO2 concentration and δ13C values. Varying impacts of soil temperature and moisture on CO2 concentration were revealed, highlighting its impact on soil physical and soil biological controls. Higher levels of CO2 concentration and a more distinct seasonal dynamics were detected at the beech site compared to the pine site. The collected data provide a suitable database for calculation of CO2 efflux and modelling of soil respiration.

  1. Carbon isotope fractionation of methyl bromide during agricultural soil fumigations

    Science.gov (United States)

    Bill, M.; Miller, L.G.; Goldstein, Allen H.

    2002-01-01

    The isotopic composition of methyl bromide (CH3Br) has been suggested to be a potentially useful tracer for constraining the global CH3Br budget. In order to determine the carbon isotopic composition of CH3Br emitted from the most significant anthropogenic application (pre-plant fumigation) we directly measured the ??13C of CH3Br released during commercial fumigation. We also measured the isotopic fractionation associated with degradation in agricultural soil under typical field fumigation conditions. The isotopic composition of CH3Br collected in soil several hours after injection of the fumigant was -44.5??? and this value increased to -20.7??? over the following three days. The mean kinetic isotope effect (KIE) associated with degradation of CH3Br in agricultural soil (12???) was smaller than the reported value for methylotrophic bacterial strain IMB-1, isolated from previously fumigated agricultural soil, but was similar to methylotrophic bacterial strain CC495, isolated from a pristine forest litter zone. Using this fractionation associated with the degradation of CH3Br in agricultural soil and the mean ??13C of the industrially manufactured CH3Br (-54.4???), we calculate that the agricultural soil fumigation source has a carbon isotope signature that ranges from -52.8??? to -42.0???. Roughly 65% of industrially manufactured CH3Br is used for field fumigations. The remaining 35% is used for structural and post-harvest fumigations with a minor amount used during industrial chemical manufacturing. Assuming that the structural and post-harvest fumigation sources of CH3Br are emitted without substantial fractionation, we calculate that the ??13C of anthropogenically emitted CH3Br ranges from -53.2??? to -47.5???.

  2. Three-dimensional intramolecular dynamics: Internal rotation of (CH3)3GeBr

    International Nuclear Information System (INIS)

    The microwave spectra of (CH3)374Ge79Br and its isotopologues (CH3)372Ge79Br and (CH3)374Ge81Br have been studied in the frequency range from 2.4-20 GHz revealing the complex internal dynamics of this organometallic molecule with three internal rotors. The assignment of the complex spectrum has been facilitated by permutation-inversion theory - the appropriate molecular symmetry group is G162. The V3 barrier to internal rotation is determined to be 4.783(12) kJ/mol. An analysis of the bromine quadrupole coupling yields the description of the Ge-Br and the Ge-C bonding characters. From this analysis we find that the bromine atom has a positive partial charge resulting from π-backbonding of the bromine towards germanium. From isotopic substitution, the Ge-Br bond distance could be determined to 2.34589(21) A

  3. Reaction cross section and matter radius measurements of proton-rich Ga, Ge, As, Se and Br nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Lima, G.F.; Lepine-Szily, A. E-mail: alinka.lepine@dfn.if.usp.br; Villari, A.C.C.; Mittig, W.; Lichtenthaeler, R.; Chartier, M.; Orr, N.A.; Angelique, J.C.; Audi, G.; Baldini-Neto, E.; Carlson, B.V.; Casandjian, J.M.; Cunsolo, A.; Donzaud, C.; Foti, A.; Gillibert, A.; Hirata, D.; Lewitowicz, M.; Lukyanov, S.; MacCormick, M.; Morrissey, D.J.; Ostrowski, A.N.; Sherrill, B.M.; Stephan, C.; Suomijaervi, T.; Tassan-Got, L.; Vieira, D.J.; Wouters, J.M

    2004-05-03

    Proton-rich isotopes of Ga, Ge, As, Se and Br had their total reaction cross sections ({sigma}{sub R}) measured. Root-mean-squared matter radii were determined from Glauber model calculations, which reproduced the experimental {sigma}{sub R} values. For all isotopic series a decrease of the r{sub rms} with increasing neutron number was observed.

  4. Anomalous behaviour of matter radii of proton-rich Ga, Ge, As, Se and Br nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Lepine-Szily, A.; Lichtenthaeler, R. [Instituto de Fisica-Universidade de Sao Paulo (Brazil); Lima, G.F. [Inst. di Fisica, Univ. Sao Paulo (Brazil)]|[FACENS, Faculdade de Engenharia de Sorocaba (Brazil); Villari, A.C.C. [GANIL, IN2P3-CNRS/DSM-CEA (France)]|[Physics Division, Argonne National Laboratory, IL (United States); Mittig, W.; Casandjian, J.M.; Lewitowicz, M. [IN2P3-CNRS/DSM-CEA, GANIL (France); Chartier, M. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Orr, N.A.; Angelique, J.C. [ISMRA et Universite de Caen, LPC, IN2P3-CNRS (France); Audi, G. [CSNSM, Orsay Campus (France); Cunsolo, A.; Foti, A. [INFN, Catania (Italy); Donzaud, C.; MacCormick, M.; Stephan, C.; Suomijaervi, T.; Tassan-Got, L. [IPN Orsay (France); Gillibert, A.; Hirata, D. [Open University, Department of Physics and Astronomy (United Kingdom); Lukyanov, S.; Morrissey, D.J.; Sherrill, B.M. [Michigan State University, NSCL, East Lansing, MI (United States); Ostrowski, A.N. [GANIL, IN2P3-CNRS/DSM-CEA (France)]|[Institut fur Physik, Universitat Mainz (Germany); Vieira, D.J.; Wouters, J.M. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2005-09-01

    Proton-rich isotopes of Ga, Ge, As, Se and Br had their total reaction cross-sections ({sigma}{sub R}) measured. Root-mean-squared matter radii were determined from Glauber model calculations, which reproduced the experimental {sigma}{sub R} values. For all isotopic series a decrease of the r{sub rms} with increasing neutron number and a correlation with deformation was observed. (orig.)

  5. Sepp, Brüder

    OpenAIRE

    2009-01-01

    Vater der Brüder war Johann S. (* 24.6.1626 Kaltern/Südtirol [Caldaro/I], † zw. 1679/84 Schlanders/Südtirol [Silandro/I]). Paul (Paolo): * 1649 Kaltern/Südtirol (Caldaro/I), † April 1670 Bozen/Südtirol (Bolzano/I) oder 1692 Kaltern. Sänger, Komponist, Organist.

  6. Underground-brändien rakentuminen

    OpenAIRE

    Hänninen, Johanna

    2010-01-01

    Markkinajohtajuudesta eri toimialoilla taistelevat usein suuret ja kauan toiminnassa olleet brändit, joiden haastaminen saattaa olla vaikeaa. Brändinrakennus kannattaakin suunnata näiden suurien brändien väliin jääviin tyhjiin markkinarakoihin. Yksi esimerkki tällaisesta hyvin hyödynnetystä markkinaraosta ovat underground-brändit, joiden brändinrakennuksen lähtökohtana ei ole kilpailla toimialan suurien brändien kanssa, vaan hallita omaa markkinarakoaan kohdennetulla tarjonnallaan. Niiden tav...

  7. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    Directory of Open Access Journals (Sweden)

    M. Dorf

    2005-12-01

    Full Text Available For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM. Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY satellite instrument. The balloon observations include (a balloon-borne in situ resonance fluorescence detection of BrO, (b balloon-borne solar occultation DOAS measurements (Differential Optical Absorption Spectroscopy of BrO in the UV, and (c BrO profiling from the solar occultation SAOZ (Systeme d'Analyse par Observation Zenithale balloon instrument. Since stratospheric BrO is subject to considerable diurnal variation and none of the measurements are performed close enough in time and space for a direct comparison, all balloon observations are considered with reference to outputs from the 3-D CTM. The referencing is performed by forward and backward air mass trajectory calculations to match the balloon with the satellite observations. The diurnal variation of BrO is considered by 1-D photochemical model calculation along the trajectories. The 1-D photochemical model is initialised with output data of the 3-D model with additional constraints on the vertical transport, the total amount and photochemistry of stratospheric bromine as given by the various balloon observations. Total [Bry]=(20.1±2.8pptv obtained from DOAS BrO observations at mid-latitudes in 2003, serves as an upper limit of the comparison. Most of the balloon observations agree with the photochemical model predictions within their given error estimates. First retrieval exercises of BrO limb profiling from the SCIAMACHY satellite instrument agree to <±50% with the photochemically-corrected balloon observations, and tend to show less agreement

  8. Oxygen isotopes separation during fluorination of oxygen-containing compounds

    International Nuclear Information System (INIS)

    The mechanisms of separation of oxygen isotopes in the reaction of water with BrF5 and CoF3 and of calcium sulphate with CsBrF4 are considered. The reaction of water with BrF5 is accompanied by enrichment of the oxygen released with the light isotope 16O, and with CoF3, by enrichment with the heavy isotope 18O. The separation of the oxygen isotopes attending the reaction of water with CoF3 is due to the establishment of isotopic equilibrium between the oxygen and the intermediate reaction product, i.e. the hydroderivative of cobalt trifluoride (α=1.016 at 350 deg C). In the case of BrF5 a kinetic isotopic effect takes place (α=0.994sup(*) at 25 deg C and α=0.996 at 120 deg C), which is due to the preferential rupture of the H-16O bond (α is the separation coefficient). The incomplete release of oxygen in the form of O2 from CaSO4 does not lead to separation of the oxygen isotopes, probably becaused of the equivalence of all the peripheral oxygen atoms in the SO4-2 anion from the point of view of the reaction with CsBrF4

  9. Isotopic Biogeochemistry

    Science.gov (United States)

    Hayes, J. M.

    1985-01-01

    An overview is provided of the biogeochemical research. The funding, productivity, personnel and facilities are reviewed. Some of the technical areas covered are: carbon isotopic records; isotopic studies of banded iron formations; isotope effects in microbial systems; studies of organic compounds in ancient sediments; and development in isotopic geochemistry and analysis.

  10. Mass independent isotope separations

    International Nuclear Information System (INIS)

    Mass independent separations between isotopes of an element were first observed by Clayton on 17 O and 18 O from the Allende meteorite and attributed then to nucleosynthesis. Anomalous ratios of isotope abundance known at that time were due to nuclear processes. Later, atmospheric ozone and stratospheric CO2 were shown to exhibit mass independent isotope composition of oxygen. Several formation mechanisms of these 'anomalous' molecules have been proposed, none being completely satisfactory. In the laboratory, these mass independent chemical separation effects were eventually reproduced. Anomalous separations were also obtained between isotopes of uranium, and even of light elements such as magnesium. These were first connected with irregularities in atomic nucleus volumes. Such effects are not recorded on natural terrestrial samples. Two main reasons prevent such observations from having been made. Firstly, laboratories investigating isotope compositions of elements, publish almost exclusively deltas of one isotope only. But, to look for possible anomalies, one needs to compare each isotope abundance in a sample similar to that in the standard used as origin of deltas. An example of such calculation will be given. Secondly, deltas of isotopes published by different laboratories are usually not comparable to better than a few per mil. The reason is that, to calculate deltas, most laboratories use working standards whose absolute values may not be exactly established as they are not crucial to their work. Several per mil differences will be shown to be implied between the 'absolute' isotope abundance of 13 C of standards, reputedly the same, used by different laboratories. Laboratories making surveys of natural samples should be encouraged, e.g. by IUPAC, to cover every isotope of multiple isotope elements, and to make, at not infrequent intervals, a close comparison of their working standards with internationally distributed ones. (author)

  11. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    Directory of Open Access Journals (Sweden)

    M. Dorf

    2006-01-01

    Full Text Available For the first time, results of four stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM. Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY satellite instrument. The balloon observations include (a balloon-borne in situ resonance fluorescence detection of BrO (Triple, (b balloon-borne solar occultation DOAS measurements (Differential Optical Absorption Spectroscopy of BrO in the UV, and (c BrO profiling from the solar occultation SAOZ (Systeme d'Analyse par Observation Zenithale balloon instrument. Since stratospheric BrO is subject to considerable diurnal variation and none of the measurements are performed close enough in time and space for a direct comparison, all balloon observations are considered with reference to outputs from the 3-D CTM. The referencing is performed by forward and backward air mass trajectory calculations to match the balloon with the satellite observations. The diurnal variation of BrO is considered by 1-D photochemical model calculation along the trajectories. The 1-D photochemical model is initialised with output data of the 3-D model with additional constraints on the vertical transport, the total amount and photochemistry of stratospheric bromine as given by the various balloon observations. Total [Bry]=(20.1±2.5 pptv obtained from DOAS BrO observations at mid-latitudes in 2003, serves as an upper limit of the comparison. Most of the balloon observations agree with the photochemical model predictions within their given error estimates. First retrieval exercises of BrO limb profiling from the SCIAMACHY satellite instrument on average agree to around 20% with the photochemically-corrected balloon observations of the remote sensing instruments (SAOZ

  12. Yrityksen brändin uudistaminen

    OpenAIRE

    Saarimaa, Petri

    2015-01-01

    Brändin rakentaminen on tänä päivänä tärkeä osa yrityksen näkyvyyden ja kilpailukyvyn edistämisessä. Huolellisesti rakennetulla brändillä ja hyvällä markkinoinnilla yritys voi erottua kilpailijoistaan positiivisesti. Tie menestyvään brändiin on kuitenkin pitkä prosessi. Toimeksiantajana opinnäytetyössä toimi rakennusyritys Rakennus Vuoriot Oy. Opinnäytetyön tavoitteena oli toteuttaa yritykselle brändin uudistaminen luomalla kokonaan uusi perusta ja rakennusosat olemassa olevalle brändille...

  13. Ravintola Teerenpelin brändi

    OpenAIRE

    Malaste, Paavo-Sakari

    2007-01-01

    Tässä opinnäytetyössä käsitellään brändiä ja sen luomista palveluyrityksissä. Tässä työssä tutkitaan myös millaisena asiakkaat kokevat Teerenpeli-ravintolan brändin. Teoriaosassa selvitetään brändin luomista ja asemointia palveluyrityksissä. Brändin luomiseen palveluyrityksissä liittyy samoja piirteitä kuin tavaroidenkin kohdalla, mutta palvelut eroavat tavaroista siinä, että ne ovat aineettomia. Brändillä tarkoitetaan sekä brändin luojan näkemystä eli brändi-identiteettiä että asiakkaiden nä...

  14. New insight into halogen release from experimental studies on BrO/Br ratios in volcanic plumes

    Science.gov (United States)

    Bobrowski, Nicole; Wittmer, Julian; Liotta, Marcello; Calabrese, Sergio; Giuffrida, Giovanni; Brusca, Lorenzo; Platt, Ulrich

    2014-05-01

    Since the discovery of BrO in a volcanic plume (Bobrowski et al. 2003) many measurements have been performed as well as modelling to understand the radical chemistry in volcanic plumes, in particular, the interaction between volcanic gas species, released under strongly reduced conditions, and the oxidizing atmosphere. Besides the goal in atmospheric chemistry to better determine the impact of volcanic emission (e.g. reactive bromine) on the local (and maybe global) scale, volcanologists also have an interest to understand if the BrO/SO2 ratios can be used as a monitoring parameter giving further insides in dynamic processes of volcanoes. However, one of the arguments which potentially makes volcanological interpretations difficult is the reactivity of BrO. Therefore it is, of great importance to link the measurements of BrO and gaseous hydrogen bromide to the total emission flux of bromine in order to estimate the pristine gas composition released from magmas. In particular, trace gas composition of the surrounding atmosphere, the volcanic gas composition and meteorological parameters can all potentially effect the formation of BrO and might have to be considered. Some of these factors potentially also influence near source (crater rim) in-situ measurement. We need to answer the question: Can we correlate BrO measurements to the total bromine outgassing? Only with this knowledge we can relate changes of the measured gas ratios (BrO/SO2) to the volcanic fluids emitted by the underlying magma and can interpret data as signals from depth, which provide insight on the degassing of magmatic bodies inside the Earth. Some studies indicate that the BrO/SO2 ratio is close to a temporarily equilibrium already after only few minutes of the gas emission from the vent (e.g. Bobrowski and Giuffrida, 2012). This equilibrium seems to be relatively independent from meteorological parameters except for extreme conditions. We here present an empirical approach to answer the above

  15. BR2 reactor neutron beams

    International Nuclear Information System (INIS)

    The use of reactor neutron beams is becoming increasingly more widespread for the study of some properties of condensed matter. It is mainly due to the unique properties of the ''thermal'' neutrons as regards wavelength, energy, magnetic moment and overall favorable ratio of scattering to absorption cross-sections. Besides these fundamental reasons, the impetus for using neutrons is also due to the existence of powerful research reactors (such as BR2) built mainly for nuclear engineering programs, but where a number of intense neutron beams are available at marginal cost. A brief introduction to the production of suitable neutron beams from a reactor is given. (author)

  16. Aagesta-BR3 Decommissioning Cost. Comparison and Benchmarking Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Geoff [NAC International, Henley on Thames (United Kingdom)

    2002-11-01

    25 is equipment. The BR3 work packages described in this report add up to something like 83,000 labour hours plus about MSEK 13 of investments and consumables costs. At Swedish average team labour rates 83,000 hours would equate to about MSEK 52. Adding the investment cost of MSEK 13 gives a total of about MSEK 65. This of course is quite close to the Aagesta figure but it would be wrong to draw immediate, firm conclusions based on these data. Such a comparison should take into account, inter alia: The number and relative sizes of the equipment decontaminated and dismantled at Aagesta and BR3. The assumed productivity in the Aagesta estimate compared to the actual BR3 figures. The physical scale of the Aagesta reactor is somewhat larger than the BR3 reactor, so all other things being equal, one might expect the Aagesta decommissioning cost estimate to be higher than for BR3. Aagesta has better access overall, which should help to constrain costs. The productivity ratio for workers at BR3 on average was high - generally 80 per cent or more, so this is unlikely to be exceeded at Aagesta and might not be equalled, which would tend to push the Aagesta cost up relative to the BR3 situation. There is an additional question of the possible extra work performed at BR3 due to the R and D nature of the project. The BR3 data analysed has tried to strip away any such 'extra' work but nevertheless there may be some residual effect on the final numbers. Analysis and comparison of individual work packages has raised several conclusions, as follows: The constructed cost for Aagesta using BR3 benchmark data is encouragingly close to the Aagesta estimate value but it is not clear that the way of deriving the Aagesta estimate for decontamination was entirely rigorous. The reliability of the Aagesta estimate on these grounds therefore might reasonably be questioned. A significant discrepancy between the BR3 and Aagesta cases appears to exist in respect of the volumes of waste

  17. Ozone Depletion Potential of CH3Br

    Science.gov (United States)

    Sander, Stanley P.; Ko, Malcolm K. W.; Sze, Nien Dak; Scott, Courtney; Rodriquez, Jose M.; Weisenstein, Debra K.

    1998-01-01

    The ozone depletion potential (ODP) of methyl bromide (CH3Br) can be determined by combining the model-calculated bromine efficiency factor (BEF) for CH3Br and its atmospheric lifetime. This paper examines how changes in several key kinetic data affect BEF. The key reactions highlighted in this study include the reaction of BrO + H02, the absorption cross section of HOBr, the absorption cross section and the photolysis products of BrON02, and the heterogeneous conversion of BrON02 to HOBR and HN03 on aerosol particles. By combining the calculated BEF with the latest estimate of 0.7 year for the atmospheric lifetime of CH3Br, the likely value of ODP for CH3Br is 0.39. The model-calculated concentration of HBr (approximately 0.3 pptv) in the lower stratosphere is substantially smaller than the reported measured value of about I pptv. Recent publications suggested models can reproduce the measured value if one assumes a yield for HBr from the reaction of BrO + OH or from the reaction of BrO + H02. Although the DeAlore et al. evaluation concluded any substantial yield of HBr from BrO + HO2 is unlikely, for completeness, we calculate the effects of these assumed yields on BEF for CH3Br. Our calculations show that the effects are minimal: practically no impact for an assumed 1.3% yield of HBr from BrO + OH and 10% smaller for an assumed 0.6% yield from BrO + H02.

  18. Response of LaBr3(Ce) scintillators to 14 MeV fusion neutrons

    International Nuclear Information System (INIS)

    The response of a 3″×3″ LaBr3(Ce) scintillator to 14 MeV neutron irradiation has been measured at the Frascati Neutron Generator and simulated by means of a dedicated MCNP model. Several reactions are found to contribute to the measured response, with a key role played by neutron inelastic scattering and (n,2n) reactions on 79Br, 81Br and 139La isotopes. An overall 43% efficiency to 14 MeV neutron detection above an experimental threshold of 0.35 MeV is calculated and confirmed by measurements. Post irradiation activation of the crystal has been also observed and is explained in terms of nuclear decays from the short lived 78Br and 80Br isotopes produced in (n,2n) reactions. The results presented in this paper are of relevance for the design of γ-ray detectors in burning plasma fusion experiments of the next generation, such as ITER, where capability to perform measurements in an intense 14 MeV neutron flux is required

  19. Practical limitations for the release of fission products during the operation of a research reactor: a case study of BR2

    Energy Technology Data Exchange (ETDEWEB)

    Joppen, F. [Health Physics and Safety Department, SCK-CEN, B-2400 Mol (Belgium)

    1998-07-01

    Failure of the cladding of a fuel element is an event occurring from time to time while operating a research reactor. As a consequence, fission products are released in the primary circuit of the reactor. This contamination means no direct hazard for the workers or for the environment in case the reactor has a closed primary circuit. The operator can decide to continue the irradiation to finish a scientific experiment or a commercial isotope production program. However, the operator cannot prolong the cycle regardless the concentration fission products in the primary loop. Beside the limitations imposed by the regulatory authorities, ALARA considerations should be taken into account. An untimely stop of the reactor can have serious financial consequences and prolonged operation causes higher radiation doses. This paper gives an overview of decision process applied in case of detection of fission products in the primary circuit of BR2. (author)

  20. Practical limitations for the release of fission products during the operation of a research reactor: a case study of BR2

    International Nuclear Information System (INIS)

    Failure of the cladding of a fuel element is an event occurring from time to time while operating a research reactor. As a consequence, fission products are released in the primary circuit of the reactor. This contamination means no direct hazard for the workers or for the environment in case the reactor has a closed primary circuit. The operator can decide to continue the irradiation to finish a scientific experiment or a commercial isotope production program. However, the operator cannot prolong the cycle regardless the concentration fission products in the primary loop. Beside the limitations imposed by the regulatory authorities, ALARA considerations should be taken into account. An untimely stop of the reactor can have serious financial consequences and prolonged operation causes higher radiation doses. This paper gives an overview of decision process applied in case of detection of fission products in the primary circuit of BR2. (author)

  1. Phase diagram of the CsBr-CaBr2 system

    Institute of Scientific and Technical Information of China (English)

    BAO Xinhua; CHEN Nianyi; LU Wencong; CHENG Zhixuan; LUO Yunyun; LU Weiying; XIA Yiben

    2006-01-01

    The phase diagram of the CsBr-CaBr2 system was re-determined by using differential thermal analysis and high temperature and room temperature X-ray diffraction analysis. It is concluded that there are three intermediate compounds in this system: a congruently melting compound, CsCaBr3, with a melting point of 823℃ and two incongruently melting compounds, Cs2CaBr4 and Cs3Ca2Br7, whose peritectic points being 597℃ and 635℃, respectively. X-ray diffraction analysis indicated that compound CsCaBr3 is of slightly distorted perovskite structure.

  2. Miten brändi säilyttää brändiarvonsa?

    OpenAIRE

    Sara, Maria

    2015-01-01

    Tässä opinnäytetyössä tarkasteltiin brändiä ja sen ylläpitämistä. Tavoitteena oli selvittää, miten brändi voi säilyttää jo saavuttamansa brändiarvon. Brändillä tarkoitetaan tavaramerkin ympärille muodostunutta positiivista mielikuvaa. Yrityksen kannalta brändi on kilpailukeino. Vahvan brändin etuja yritykselle ovat esimerkiksi uskolliset asiakkaat, haluttavuus yhteistyökumppanina ja kiinnostavuus työnantajana. Aihe valittiin työn tekijän oman kiinnostuksen perusteella. Aihetta tarkastelti...

  3. Annealing and dehydration studies following (n,γ) recoil in Pr(BrO3)3.6H2O

    International Nuclear Information System (INIS)

    Initial retention values determined with respect to 80Br, 80mBr and 82Br isotopes in case of neutron activated Pr(BrO3)3.6H2O are 23, 23 and 30 (±2%). Isothermal dehydration and annealing are carried out over the temperature range 80 - 140 degC. Maximum observed weight loss of 12% is assigned to dehydration. Maximum recovery of the parent compound is reached to 60% value following the first order rate law. Results are discussed in the light of hydration energy and oxidation state of the recoil Pr atom. (author). 6 refs., 2 figs

  4. Variants of closing the nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Andrianova, E. A., E-mail: Andrianova-EA@nrcki.ru; Davidenko, V. D.; Tsibulskiy, V. F.; Tsibulskiy, S. V. [National Research Center Kurchatov Institute (Russian Federation)

    2015-12-15

    Influence of the nuclear energy structure, the conditions of fuel burnup, and accumulation of new fissile isotopes from the raw isotopes on the main parameters of a closed fuel cycle is considered. The effects of the breeding ratio, the cooling time of the spent fuel in the external fuel cycle, and the separation of the breeding area and the fissile isotope burning area on the parameters of the fuel cycle are analyzed.

  5. Variants of closing the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Influence of the nuclear energy structure, the conditions of fuel burnup, and accumulation of new fissile isotopes from the raw isotopes on the main parameters of a closed fuel cycle is considered. The effects of the breeding ratio, the cooling time of the spent fuel in the external fuel cycle, and the separation of the breeding area and the fissile isotope burning area on the parameters of the fuel cycle are analyzed

  6. Gas-Phase Reactions of (n, γ) and Isomeric Transition-Activated Br80 with Alkanes and Haloalkanes

    International Nuclear Information System (INIS)

    Experimental data are presented on the gas-phase reactions of alkanes and haloalkanes with bromine atoms and ions activated by nuclear transformations. The target molecules include CH4 CD4, C2H6, C2D6, CH3Cl, CH2Cl2, CHCI3, CCl4, CH2F2, CHF3, CF4, C2F6, CF3Br, and CH3Br. The nuclear reactions and transformations used in producing the energetic recoil atoms and ions were Br80m (isomeric transition), Br80, and Br79 (n, γ) Br80. The percentage of the radioactivity found in organic combination (the organic yield, O. Y.) was determined as a function of the concentration of the target molecule in the mole-fraction range of about 0.95 to 1.00. Elemental Br2 served both as a source of hot atoms and as a scavenger. Usually 20-50 separate samples of each reaction system were examined and the data of O.Y. as a function of the concentration of scavenger were plotted and extrapolated to unit mole fraction of target molecule. In all cases, die O.Y. decreased with increasing halogen concentration. Data on the (n, γ) activated reactions of Br80 with isotopic alkanes suggest a comparable extrapolated O.Y. for C2H6 and C2D6, but an O.Y. for CD4 about half of the O.Y. with CH4. Gas chromatographic analysis of the organic products indicates that about 90% of the O.Y. in CH4 is caused by CH3Br and 10% by CH2Br2 For CD4 as the target the distribution of organic activity is approx. 75% CD3Br and 25% CD2Br2. These various data are discussed in terms of possible mechanisms involving hot halogen atoms and ions

  7. Isotopic geology

    International Nuclear Information System (INIS)

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  8. Isotopic clusters

    International Nuclear Information System (INIS)

    Spectra of isotopically mixed clusters (dimers of SF6) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  9. Photoinduced Br Desorption from CsBr Thin Films Grown on Cu(100)

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, Matthew T.; Joly, Alan G.; Hess, Wayne P.; Shluger, AL

    2015-10-22

    Thin films of CsBr deposited onto metals such as copper are potential photocathode materials for light sources and other applications. We investigate desorption dynamics of Br atoms from CsBr films grown on insulator (KBr, LiF) and metal (Cu) substrates induced by sub-bandgap 6.4 eV laser pulses. The experimental results demonstrate that the peak kinetic energy of Br atoms desorbed from CsBr/Cu films is much lower than that for the hyperthermal desorption from CsBr/LiF films. Kelvin probe measurements indicate negative charge at the surface following Br desorption from CsBr/Cu films. Our ab initio calculations of excitons at CsBr surfaces demonstrate that this behavior can be explained by an exciton model of desorption including electron trapping at the CsBr surface. Trapped negative charges reduce the energy of surface excitons available for Br desorption. We examine the electron-trapping characteristics of low-coordinated sites at the surface, in particular, divacancies and kink sites. We also provide a model of cation desorption caused by Franck-Hertz excitation of F centers at the surface in the course of irradiation of CsBr/Cu films. These results provide new insights into the mechanisms of photoinduced structural evolution of alkali halide films on metal substrates and activation of metal photocathodes coated with CsBr.

  10. Laser Pyrolysis of CH3Br

    OpenAIRE

    Chang, Hua,; Hsieh, Jang Ching

    1993-01-01

    Laser pyrolysis of CH3Br by a strong laser irradiation was studied in this work. Besides a fine needle of solid carbon was deposited at the surface on the substrate, HBr and CH4, were found as gaseous products with a ratio of 2:1. Small amount of C2H2 was also detected. The variation in the pressures of CH3Br, HBr and CH4 were measured by Raman spectroscopy. It indicated that the decomposition of CH3Br was first order with respect to CH3Br. The reaction mechanism of the laser pyrolysis was su...

  11. Rotational-isotopic symmetries

    International Nuclear Information System (INIS)

    In this note we submit a nonlocal (integral) generalization of the rotational-isotopic symmetries O-circumflex(3) introduced in preceding works for nonlinear and nonhamiltonian systems in local approximation. By recalling that the Lie-isotopic theory naturally admits nonlocal terms when all embedded in the isounit, while the conventional symplectic geometry is strictly local-differential, we introduce the notion of symplectic-isotopic two-forms, which are exact symplectic two-forms admitting a factorization into the Kronecker product of a canonical two-form time the isotopic element of an underlying Euclidean-isotopic space. Topological consistency is then achieved by embedding all nonlocal terms in the isounit of the iso-cotangent bundle, while keeping the local topology for the canonical part. In this way, we identify the symplectic-isotopic geometry as being the natural geometrical counterpart of the Lie-isotopic theory. The results are used for the introduction of the notion of Birkhoffian angular momentum, that is, the generalization of the conventional canonical angular momentum which is applicable to Birkhoffian systems with generally nonlinear, nonlocal and nonhamiltonian internal forces. The generators J (and the parameters θ) coincide with the conventional quantities. Nevertheless, the quantity J is defined on the underlying Euclidean-isotopic space, by therefore acquiring a generalized magnitude. The isocommutation rules and isoexponentiation of the Birkhoffian angular momentum are explicitly computed and shown to characterize the most general known nonlinear and nonlocal realization of the isorotational symmetry. The local isomorphisms between the infinitely possible isotopes O-circumflex(3) and the conventional symmetry O(3) is proved. Finally the isosymmetries O-circumflex(3) are used to characterize the conserved, total, Birkhoffian angular momentum of closed nonselfadjoint systems. (author). 4 refs

  12. Punkaliven brändiohjeisto

    OpenAIRE

    Vikiö, Timo

    2010-01-01

    Tässä opinnäytetyössä käsitellään brändiohjeiston rakentamista pk-yritys Punkalivelle, joka valmistaa designkalusteita ja paviljonkeja Finnforestin kehittämästä Kerto®-puumateriaalista. Yrityksen strategisena lähtökohtana on ollut rakentaa uutta yritys-trendiä, joka ottaa huomioon nykypäivän vaativan kuluttajan ja on kiinnostunut kestä-vän kehityksen arvoista. Opinnäytetyön tavoitteena on ollut kartoittaa kestävän kehityksen käsitettä, siihen liit-tyviä tekijöitä niin viestinnässä kuin mu...

  13. Sokos Herkun brändimielikuva nuorten silmissä brändiarvojen perusteella mitattuna

    OpenAIRE

    Lappalainen, Sanna

    2016-01-01

    Tämä opinnäytetyö tehtiin Tampereen keskustassa sijaitsevalle Sokos Herkku ruokakaupalle. Opinnäytetyöni käsittelee brändin rakentamista ja brändimielikuvan muodostumista. Teoriaosiossa käydään läpi brändin rakentaminen brändi-identiteetin luomisesta brändin johtamiseen brändipääomalla. Teoriaosiossani katsotaan brändiä myös palvelubrändin näkökulmasta, sillä elintarvikekaupat ovat yhä kasvavassa määrin palveluyrityksiä. Tutkimuksen tavoitteena oli kehittää Sokos Herkun brändimielikuvaa n...

  14. Aagesta-BR3 Decommissioning Cost. Comparison and Benchmarking Analysis

    International Nuclear Information System (INIS)

    equipment. The BR3 work packages described in this report add up to something like 83,000 labour hours plus about MSEK 13 of investments and consumables costs. At Swedish average team labour rates 83,000 hours would equate to about MSEK 52. Adding the investment cost of MSEK 13 gives a total of about MSEK 65. This of course is quite close to the Aagesta figure but it would be wrong to draw immediate, firm conclusions based on these data. Such a comparison should take into account, inter alia: The number and relative sizes of the equipment decontaminated and dismantled at Aagesta and BR3. The assumed productivity in the Aagesta estimate compared to the actual BR3 figures. The physical scale of the Aagesta reactor is somewhat larger than the BR3 reactor, so all other things being equal, one might expect the Aagesta decommissioning cost estimate to be higher than for BR3. Aagesta has better access overall, which should help to constrain costs. The productivity ratio for workers at BR3 on average was high - generally 80 per cent or more, so this is unlikely to be exceeded at Aagesta and might not be equalled, which would tend to push the Aagesta cost up relative to the BR3 situation. There is an additional question of the possible extra work performed at BR3 due to the R and D nature of the project. The BR3 data analysed has tried to strip away any such 'extra' work but nevertheless there may be some residual effect on the final numbers. Analysis and comparison of individual work packages has raised several conclusions, as follows: The constructed cost for Aagesta using BR3 benchmark data is encouragingly close to the Aagesta estimate value but it is not clear that the way of deriving the Aagesta estimate for decontamination was entirely rigorous. The reliability of the Aagesta estimate on these grounds therefore might reasonably be questioned. A significant discrepancy between the BR3 and Aagesta cases appears to exist in respect of the volumes of waste arising from the

  15. Chemical effects of the radioactive decay 7677Kr→7677Br reactions of recoil bromine in the gas phase

    International Nuclear Information System (INIS)

    This thesis describes the chemical reactions of 76Br and 77Br recoil species, formed by radioactive decay of 76Kr and 77Kr, with various gaseous compounds. Due to differences in decay energy and decay mode the resulting 76Br and 77Br isotopes obtain different kinetic energies and carry different charges; 76Kr decays completely via electron capture and the resulting 76Br is formed with a multiple positive charge and a kinetic energy of 7.2 eV at the most. 77Kr decays for only 16% via electron capture, resulting in 77Brsup(n+) ions with a maximal kinetic energy of 56.9 eV. 84% of the 77Kr decays via #betta#+ particle emission, which leads to 77Br species, that are mainly negative or uncharged and that possess a maximal kinetic energy of 36.4 eV. The aim of this study was to explore whether these initial differences in charge and kinetic energy are reflected in the products, formed after chemical reactions of 76Br and 77Br. (Auth.)

  16. Som brødre vi dele

    DEFF Research Database (Denmark)

    Holm, Claus

    2010-01-01

    Debatten om forskningsfrihed gjorde broderskabet til forudsætningen for forskningfrihed, men skal forskere dele som brødre i 2010?......Debatten om forskningsfrihed gjorde broderskabet til forudsætningen for forskningfrihed, men skal forskere dele som brødre i 2010?...

  17. Cd4As2Br3

    Directory of Open Access Journals (Sweden)

    Mohammed Kars

    2014-03-01

    Full Text Available Single crystals of Cd4As2Br3 (tetracadmium biarsenide tribromide were grown by a chemical transport reaction. The structure is isotypic with the members of the cadmium and mercury pnictidohalides family with general formula M4A2X3 (M = Cd, Hg; A = P, As, Sb; X = Cl, Br, I and contains two independent As atoms on special positions with site symmetry -3 and two independent Cd atoms, of which one is on a special position with site symmetry -3. The Cd4As2Br3 structure consists of AsCd4 tetrahedra sharing vertices with isolated As2Cd6 octahedra that contain As–As dumbbells in the centre of the octahedron. The Br atoms are located in the voids of this three-dimensional arrangement and bridge the different polyhedra through Cd...Br contacts.

  18. A porewater – based stable isotope approach for the investigation of subsurface hydrological processes

    Directory of Open Access Journals (Sweden)

    J. Garvelmann

    2011-10-01

    Full Text Available Predicting and understanding subsurface flowpaths is still a crucial issue in hydrological research. We present an experimental approach to reveal present and past subsurface flowpaths of water in the unsaturated and saturated zone. Two hillslopes in a humid moutainous catchment have been investigated. The H2O(liquid – H2O(vapor equilibration laser spectroscopy method was used to obtain high resolution δ2H vertical depth profiles of porewater at various points along a fall line of a pasture hillslope in the southern Black Forest, Germany. The Porewater Stable Isotope Profile (PSIP approach was developed to use the integrated information of several vertical depth profiles of deuterium along two transects at the hillslopes. <br>> Different shapes of depth profiles were observed in relation to hillslope position. The statistical variability (inter-quartile range and standard deviation of each profile was used to characterize different types of depth profiles. The profiles upslope or with a weak affinity for saturation as indicated by a low topographic wetness index preserve the isotopic input signal by precipitation with a distinct seasonal variability. These observations indicate mainly vertical movement of soil water in the upper part of the hillslope before sampling. The profiles downslope or at locations with a strong affinity for saturation do not show a similar seasonal isotopic signal. The input signal is erased in the foothills and a large proportion of pore water samples are close to the isotopic values of δ2H in stream water during base flow. Near the stream indications for efficient mixing of water from lateral subsurface flow paths with vertical percolation are found.

  19. A porewater-based stable isotope approach for the investigation of subsurface hydrological processes

    Directory of Open Access Journals (Sweden)

    J. Garvelmann

    2012-02-01

    Full Text Available Predicting and understanding subsurface flowpaths is still a crucial issue in hydrological research. We present an experimental approach to reveal present and past subsurface flowpaths of water in the unsaturated and saturated zone. Two hillslopes in a humid mountainous catchment have been investigated. The H2O(liquid – H2O(vapor equilibration laser spectroscopy method was used to obtain high resolution δ2H vertical depth profiles of pore water at various points along two fall lines of a pasture hillslope in the southern Black Forest, Germany. The Porewater-based Stable Isotope Profile (PSIP approach was developed to use the integrated information of several vertical depth profiles of deuterium along transects at the hillslope. <br>> Different shapes of depth profiles were observed in relation to hillslope position. The statistical variability (inter-quartile range and standard deviation of each profile was used to characterize different types of depth profiles. The profiles upslope or with a weak affinity for saturation as indicated by a low topographic wetness index preserve the isotopic input signal by precipitation with a distinct seasonal variability. These observations indicate mainly vertical movement of soil water in the upper part of the hillslope before sampling. The profiles downslope or at locations with a strong affinity for saturation do not show a similar seasonal isotopic signal. The input signal is erased in the foothills and a large proportion of pore water samples are close to the isotopic values of δ2H in streamwater during base flow conditions indicating the importance of the groundwater component in the catchment. Near the stream indications for efficient mixing of water from lateral subsurface flow paths with vertical percolation are found.

  20. Kinetic study of thermal/radiation annealing and dehydration of nickel, bromate following 79Br(n,γ)80Br reaction

    International Nuclear Information System (INIS)

    The initial retentions of 80Br,sup(80m)Br and 82Br following neutron activation with 252Cf source of Ni(BrO3)2.6H2O at 25deg C are 17,19 and 31 +- 1% respectively. Heat and radiation treatments yield higher 80Br recovery in the hydrated salt than in the anhydrous salt. At 110deg C 80Br retention rises suddenly to close on 100% in the hydrated salt while in the anhydrous salt it increases from 22 to 42%. In both the cases thermal annealing carried over the temperature range 25-110deg C follows first order kinetics and shows 77deg C as the threshold annealing temperature. The rate of annealing increases with the rate of dehydration. The annealing data yield 2.7 and 0.49 eV as the activation energy values for the hydrated and dehydrated forms respectively while isothermal dehydration data yield the value as 0.31 eV. A probable mechanism is suggested. (author)

  1. Band structure of 79Br

    International Nuclear Information System (INIS)

    High-spin states of 79Br have been studied in the reaction 76Ge(7Li, 4nγ) at 32 MeV. A gamma-detector array with twelve Compton-suppressed HPGe detectors was used. The positive-parity yrast states, interpreted as a rotationally aligned g(9(2)) proton band, and the negative-parity ground state band have been extended to spins of (33(2+)) and (25(2-)), respectively. Lifetime measurements indicate that both bands have a similar quadrupole deformation of β2 ∼ 0.2. The positive-parity α = -(1(2)) band has been identified. Several new inter-band transitions are observed. A cranked-shell model analysis shows that the νg(9(2)) and πg(9(2)) alignments occur in the positive-parity and the negative-parity bands at rotational frequencies of ℎω ∼ 0.6 and 0.4 MeV, respectively. The level energies and the electromagnetic properties of the g(9(2)) band can be well reproduced by a particle-rotor model calculation with an axially symmetric core

  2. Simultaneous spectroscopy of $\\gamma$- rays and conversion electrons: Systematic study of EO transitions and intruder states in close vicinity of mid-shell point in odd-Au isotopes

    CERN Multimedia

    Venhart, M; Grant, A F; Petrik, K

    This proposal focuses on detailed systematic studies of the $\\beta$ /EC-decays of $^{179,181,183,185}$Hg leading to excited states in the neutron-deficient Au isotopes in the vicinity of the N=104 midshell. $\\gamma$-ray, X-ray and conversion electron de-excitations of odd-A Au isotopes will be studied simultaneously. These studies will address important structural questions such as the excitation energies of coexisting states, properties of multiple intruder states (i.e. intruder particles coupled to intruder cores) and mixing of coexisting structures. The unique combination of Hg beam purity and yields make ISOLDE a unique facility for these experiments.

  3. Structure and Heats of Formation of Iodine Fluorides and the Respective Closed-Shell Ions from CCSD(T) Electronic Structure Calculations and Reliable Prediction of the Steric Activity of the Free-Valence Electron Pair in ClF₆⁻, BrF₆⁻, and IF₆⁻

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David A.; Grant, Daniel J.; Christe, Karl O.; Peterson, Kirk A.

    2008-06-16

    The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Atomization energies at 0 K and heats of formation at 0 and 298 K are predicted for IF, IF₂-, IF₂+, IF₃, IF₄-, IF₄+,IF₅, IF₆-, IF₆+, IF₇, IF₈-, BrF₆-, and ClF₆- from coupled cluster theory [CCSD(T)] calculations with effective-core potential correlation-consistent basis sets for I. In order to achieve near chemical accuracy (±1 kcal/mol), three corrections were added to the complete basis set binding energies based on frozen-core coupled-cluster theory energies: a correction for core-valence effects, a correction for scalar relativistic effects, and a correction for firstorder atomic spin-orbit effects. Vibrational zero-point energies were computed at the coupled-cluster level of theory except for IF₆-, IF₇, and IF₈-. The calculated heats of formation for the neutral and ionic IFn fluorides were used to predict fluoride affinities. It is shown that high-level calculations are required to predict correctly the steric activity of the free-valence electron pair on the central atoms in IF₆- (C₃v), BrF₆- (Oh), and ClF₆- (Oh). The vibrational spectrum of IF₈- was reanalyzed, and complete mode descriptions for square-antiprismatic XF₈ species of D₄d symmetry are given.

  4. Lastnosti lesa bršljana

    OpenAIRE

    Merhar, Klemen

    2014-01-01

    Raziskali smo tiste izbrane lastnosti lesa navadnega bršljana (Hedera helix L.), ki bi utegnile predvideti njegovo uporabo. Raziskali smo anatomsko zgradbo in makroskopske posebnosti, vlažnost v svežem stanju, gostoto, anizotropijo krčenja in nabrekanja, kazalnike dimenzijske stabilnosti ter tlačno in upogibno trdnost bršljanovega lesa. Raziskava je pokazala, da bršljanov les spada med polvenčasto porozne drevesne vrste. Gostota absolutno suhega lesa je 522 kg/m3. Vlažnost svežega lesa, ki jo...

  5. BR2: The first year of operation after refurbishment

    International Nuclear Information System (INIS)

    The BR2 reactor has resumed operation in April 97 after an extensive refurbishment shutdown, which lasted for nearly two years. The yearly operation is presently limited to major cycles of 21 efpd, plus some short cycles for special programmes. The reactor is mainly used for irradiations in the framework of the following programs: qualification of MOX fuel at high burn-up, the PWR vessel surveillance program and associated modelling activities, the IASCC program focused on PVVR vessel intervals. The major irradiation device is the CALLISTO loop, simulating PWR conditions and comprising three in-pile sections. Additionally production activities are carried out: radio-isotopes and silicon doping. Irradiations for the surveillance programmes of beryllium and aluminum are underway; they concerns unirradiated and preirradiated samples, with various lead factors. Several refurbishment actions are still continuing, mainly: - continuation of the renewal of the process instrumentation, - extension of the BR2 DAS, - follow-up of the seismic qualification study, - follow-up of the PSA study: some detailed studies on supporting systems. A formalised training programme for the reactor operators has been launched. Special attention is given to the new reactor control desk and the emergency control panel outside of the containment building. A solution for the evacuation of the spent fuel has been adopted and is being implemented: reprocessing in La Hague

  6. Separation of sulfur isotopes

    Science.gov (United States)

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  7. Radioactive and stable isotope geology

    International Nuclear Information System (INIS)

    Aimed at post-graduate and post-doctoral researchers in geochemistry, this book reflects the rapid changes in the applications of radioactive and stable isotope analysis to a range of geological and geochemical problems. Isotropic chemistry and methods used in mass spectroscopy are discussed initially. The second section deals with radiometric dating methods. The role of isotopes in climate and environmental research is also explored. The book closes with a section on extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth's lithosphere. (UK)

  8. Brändimielikuvia kosmetiikan markkinoilla : Cliniquen brändimielikuva

    OpenAIRE

    Pitkä, Nea

    2014-01-01

    Tämän opinnäytetyön tarkoituksena oli selvittää, millainen Cliniquen brändimielikuva on kuluttajien kokemana. Clinique on suurimpia kosmetiikkabrändejä selektiivisen kosmetiikan markkinoilla. Yhdysvaltalaisella Cliniquella on omalaatuinen kliininen imago kilpailijoihinsa nähden, joten brändistä muotoutunutta mielikuvaa tutkittiin sen pohjalta. Toinen selvityksen kohde oli Cliniquen brändimielikuvan vaikutus ostopäätökseen. Työssä käsiteltiin laajasti brändin määritelmää ja olennaisimpia t...

  9. Brändivalokuva Suomessa : Kuinka saavutetaan laadukas brändivalokuva

    OpenAIRE

    Luostarinen, Antti

    2015-01-01

    Opinnäytetyössä tutkitaan mitä brändivalokuva on ja miten laadukas brändivalokuva saavutetaan Suomessa. Kentällä tapahtuvaa toimintaa lähestytään kolmesta suunnasta: valokuvaajan (toteuttaja), suunnittelijan (luova toimisto) sekä yrityksen (tilaaja) näkökulmasta. Brändivalokuvan tekemisen prosessia kuvataan yrityksen ja sen palkkaamien ulkoistettujen yhteistyötahojen toiminnan kautta. Opinnäyte ei siis ota kantaa inhouse-toiminnassa tuotettuun brändivalokuvaan. Tutkimuksen tavoitteena on...

  10. From photoelectron detachment spectra of BrHBr{sup −}, BrDBr{sup −} and IHI{sup −}, IDI{sup −} to vibrational bonding of BrMuBr and IMuI

    Energy Technology Data Exchange (ETDEWEB)

    Manz, Jörn [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectrocopy, Shanxi University, Taiyuan 030006 (China); Freie Universität Berlin, Institut für Chemie und Biochemie, 14195 Berlin (Germany); Sato, Kazuma; Takayanagi, Toshiyuki, E-mail: tako@mail.saitama-u.ac.jp; Yoshida, Takahiko [Department of Chemistry, Saitama University, Saitama City, Saitama 338-8570 (Japan)

    2015-04-28

    Photoelectron detachment XLX{sup −}(00{sup 0}0) + hν → XLX(vib) + e{sup −} + KER (X = Br or I, L = H or D) at sufficiently low temperatures photoionizes linear dihalogen anions XLX{sup −} in the vibrational ground state (v{sub 1}v{sub 2}{sup l}v{sub 3} = 00{sup 0}0) and prepares the neutral radicals XLX(vib) in vibrational states (vib). At the same time, part of the photon energy (hν) is converted into kinetic energy release (KER) of the electron [R. B. Metz, S. E. Bradforth, and D. M. Neumark, Adv. Chem. Phys. 81, 1 (1992)]. The process may be described approximately in terms of a Franck-Condon type transfer of the vibrational wavefunction representing XLX{sup −}(00{sup 0}0) from the domain close to the minimum of its potential energy surface (PES) to the domain close to the linear transition state of the PES of the neutral XLX. As a consequence, prominent peaks of the photoelectron detachment spectra (pds) correlate with the vibrational energies E{sub XLX,vib} of states XLX(vib) which are centered at linear transition state. The corresponding vibrational quantum numbers may be labeled vib = (v{sub 1}v{sub 2}{sup l}v{sub 3}) = (00{sup 0}v{sub 3}). Accordingly, the related most prominent peaks in the pds are labeled v{sub 3}. We construct a model PES which mimics the “true” PES in the domain of transition state such that it supports vibrational states with energies E{sub XLX,pds,00{sup 0}v{sub 3}} close to the peaks of the pds labeled v{sub 3} = 0, 2, and 4. Subsequently, the same model PES is also used to calculate approximate values of the energies E{sub XMuX,00{sup 0}0} of the isotopomers XMuX(00{sup 0}0). For the heavy isotopomers XHX and XDX, it turns out that all energies E{sub XLX,00{sup 0}v{sub 3}} are above the threshold for dissociation, which means that all heavy XLX(00{sup 0}v{sub 3}) with wavefunctions centered at the transition state are unstable resonances with finite lifetimes. Turning the table, bound states of the heavy XLX are van

  11. R and D on fuzzy control applications to the BR1 research reactor

    International Nuclear Information System (INIS)

    Fuzzy control applications in nuclear reactor operations present a tremendous challenge. The main reason for this is the public awareness of the risks of nuclear industry and the very strict safety regulations in force for nuclear power plants. The very same regulations prevent a researcher from quickly introducing novel fuzzy-logic methods into this field. On the other hand, the application of fuzzy logic has, despite the ominous sound of the word 'fuzzy' to nuclear engineers, a number of very desirable advantages over classical methods, e.g., its robustness and the capability to include human experience into the controller. In this paper we report an on-going R and D project for controlling the power level of the Belgian Nuclear Reactor 1 (BR1) at the Belgian Nuclear Research Centre (SCK.CEN). The project started in 1995 and aims to investigate the added value of fuzzy control for nuclear reactors. We first review some relevant literature on fuzzy logic control in nuclear reactors, then present the state-of-the-art of the BR1 project. After experimenting fuzzy logic control under off-line tests at the BR1 reactor, we now foresee a new development for a closed-loop fuzzy control as an on-line operation of the BR1 reactor. Finally, we present the new development for a closed-loop fuzzy logic control at BR1 with an understanding of the safety requirements for this real fuzzy logic control application in nuclear rectors. (author)

  12. Inductively coupled plasma-mass spectrometry for elemental analysis and isotope ratio determinations in individual organic compounds separated by gas chromatography

    International Nuclear Information System (INIS)

    A gas chromatograph (GC) with a packed column was interfaced to an inductively coupled plasma-mass spectrometer (ICP-MS) to yield atomic mass spectra from volatile organic compounds. Atomization of injected compounds was nearly complete and independent of molecular structure, so that elemental ratios could be determined. Detection limits were in the range 0.001 to 400 ng s-1, depending on the ionization energy of the element and its abundance in the background spectrum. The relative standard deviation of measured isotope ratios varied from 0.4% for Br (i.e., a ratio close to unity) to 18% for N (a very large ratio). Thus, GC-ICP-MS provides elemental and isotope ratio information that is complementary to the molecular information derived from GC-MS with conventional ionization methods

  13. Inductively coupled plasma-mass spectrometry for elemental analysis and isotope ratio determinations in individual organic compounds separated by gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Chong, N.S.; Houk, R.S.

    1987-01-01

    A gas chromatograph (GC) with a packed column was interfaced to an inductively coupled plasma-mass spectrometer (ICP-MS) to yield atomic mass spectra from volatile organic compounds. Atomization of injected compounds was nearly complete and independent of molecular structure, so that elemental ratios could be determined. Detection limits were in the range 0.001 to 400 ng s/sup -1/, depending on the ionization energy of the element and its abundance in the background spectrum. The relative standard deviation of measured isotope ratios varied from 0.4% for Br (i.e., a ratio close to unity) to 18% for N (a very large ratio). Thus, GC-ICP-MS provides elemental and isotope ratio information that is complementary to the molecular information derived from GC-MS with conventional ionization methods.

  14. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  15. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    Science.gov (United States)

    Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values

  16. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  17. Radiative forcing calculations for CH3Br

    International Nuclear Information System (INIS)

    Methyl Bromide, CH3Br, is the major organobromine species in the lower atmosphere and is a primary source of bromine in the stratosphere. It has a lifetime of 1.3 years. The IR methyl bromide spectra in the atmospheric window region, 7--13μ, was determined using a well tested Coriolis resonance and ell-doubling (and ell-resonance) computational system. A radiative forcing value of 0.00493 W/m2/ppbv was obtained for CH3Br and is approximately linear in the background abundance. This value is about 2 percent of the forcing of CFC-11 and about 278 times the forcing of C02, on a per molecule basis. The radiative forcing calculation is used to estimate the global warming potential (GWP) of CH3Br. The results give GWPs for CH3Br of the order of 13 for an integration period of 20 years and 4 for an integration period of 100 years (assuming C02 = 1, following IPCC [1994]). While CH3Br has a GWP which is approximately 25 percent of the GWP of CH4, the current emission rates are too low to cause serious atmospheric greenhouse heating effects at this time

  18. Brändikäsikirja brändinhallinnan tukena Case: Innojok Oy

    OpenAIRE

    Tamminen, Tytti; Uusitalo, Nea

    2016-01-01

    Opinnäytetyön tavoitteena oli laatia brändikäsikirja opinnäytetyön case yritys Innojok Oy:lle. Tutkimustyön tarkoituksena on selvittää, mitä tehokkaan ja hyödyllisen brändikäsikirjan tulisi sisältää, jotta sen optimaalinen käyttötarkoitus toteutuu. Toimeksianto saatiin case yritykseltä, koska yrityksellä ei ollut vielä brändikäsikirjaa olemassa. Opinnäytetyön teoreettinen viitekehys käsittelee brändiä ja brändinhallinnan merkitystä liiketoiminnan kannalta. Opinnäytetyön teoreettisen ...

  19. Optical properties of CdBr2:Eu and CdBr2:Eu, Mn crystals

    International Nuclear Information System (INIS)

    Optical and luminescent properties of the CdBr:Eu and CdBr2:Eu, Mn crystals, grown through the Stockbarger-Bridgman method in evacuated quartz ampoules, are studied within the temperature range of 85-295 K. The results obtained are compared with spectral characteristics of the CdBr2 and CdBr2:Mn crystals. The band with the maximum about 254 nm, observed in the absorption spectra of mono- and polyactivated crystals of cadmium bromide, is attributed to the 4f7 -> 4f65d electron transitions in the Eu2+ ions. The manganese sensitized luminescence is identified by excitation of the CdBr2:Eu, Mn crystals by the light from the area of this band. The nature of the capture centers, responsible for thermostimulated fluorescence, and excitation mechanisms of recombination luminescence in the studied crystals are considered

  20. Brändiopas : brändäys kauneudenhoitoalalla

    OpenAIRE

    Rastas, Kaisa

    2015-01-01

    Brändit vetoavat asiakkaan tunteisiin ja tuottavat elämyksiä sekä unohtumattomia kokemuksia. Brändi on aineeton ulottuvuus, mielikuva, joka rakentuu asiakkaan mielessä. Brändi onkin hieman erilainen eri ihmiseltä kysyttäessä. Tässä oppaassa käsiteltiin kauneudenhoitoalan yritys- ja henkilöbrändin rakentamisen vaiheita. Oppaassa käsiteltiin myös asiakaskokemuksen merkitystä menestyvän yritysbrändin rakentumisessa. Vaikka brändi termiä käytetään hyvin laajasti puhekielessä, se usein liitet...

  1. Preparation, characterization, and photocatalytic activity of porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts

    Science.gov (United States)

    Yang, Fan; Tian, Baozhu; Zhang, Jinlong; Xiong, Tianqing; Wang, Tingting

    2014-02-01

    Porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts were synthesized by a multistep route, including a dealloying method to prepare porous Ag, a transformation from Ag to AgBr and AgBrI, and a photo-reduction process to form Ag nanoparticles on the surface of AgBr and AgBrI. It was found that the porous structure kept unchanged during Ag was transferred into AgBr, AgBrI, AgBr@Ag, and AgBrI@Ag. Both porous AgBr@Ag and porous AgBrI@Ag showed much higher visible-light photocatalytic activity than cubic AgBr@Ag for the degradation of methyl orange, which is because the interconnected pore channels not only provide more reactive sites but also favor the transportation of photo-generated electrons and holes. For AgBrI@Ag, AgBrI solid solution formed at the interface of AgBr and AgI, and the phase junction can effectively separate the photo-generated electrons and holes, favorable to the improvement of photocatalytic activity. The optimal I content for obtaining the highest activity is ∼10 at.%.

  2. Brändäys pelialalla

    OpenAIRE

    Saarelainen, Joona

    2014-01-01

    Tämän opinnäytetyön tavoitteena oli tarjota lukijalle tietopaketti siitä, mikä merkitys brändeillä ja brändäyksellä on kuluttajille videopelimarkkinoilla. Työn tarkoituksena oli tarjota kansainvälisille pelimarkkinoille pyrkivälle yritykselle tietoa brändin rakentamisen aloittamisesta ja siinä tarvittavista analyyseistä. Tämä oli myös opinnäytetyöhön valittu tutkimusongelma. Opinnäytetyö kirjoitettiin kahdessa eri osassa. Teoriaosuus käsittelee suomalaista ja kansainvälistä pelialaa sekä...

  3. Production of 77 Br for medical application

    International Nuclear Information System (INIS)

    Bromine-77 is produced with the variable energy cyclotron (CV-28) at the Instituto de Engenharia Nuclear, via the 75 As. (α, 2 n) 77 Br reaction, by bombarding arsenic trioxide with 28 MeV alpha-particles. The thick target yield is 0.3 mCi/μAh. The target is dissolved in concentrated N H4 OH and 77 Br, separated from arsenic, by an anionic exchange resin, is obtained carrier-free with a separation yield greater than 90%. All the process is remotely controlled using electric and pneumatic systems, manipulators and tongs. The quality control is made by atomic absorption and gamma-ray spectroscopy. The present production rate of Br-77 is 2.3 mCi per irradiation. (author)

  4. C, O and Sr isotopic stratigraphy of carbonates pre and pos Jequitai glaciation: Bezerra-Formosa area, Goias, BR;Variacoes dos isotopos de C e Sr em carbonatos pre e pos-glaciacao Jequitai (Esturtiano) na regiao de Bezerra-Formosa, Goias

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Carlos Jose Souza de; Della Giustina, Maria Emilia Schuteski; Silva, Nivea Goulart Carramal; Santos, Roberto Ventura; Gioia, Simone Maria Costa Lima; Guimaraes, Edi Mendes; Dardenne, Marcel Auguste, E-mail: alva1@unb.b [Universidade de Brasilia (IG/UnB), DF (Brazil). Inst. de Geociencias; Sial, Alcides Nobrega; Ferreira, Valderez Pinto [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Lab. de Isotopos Estaveis (LABISE)

    2007-12-15

    Carbonate rocks of the upper Paranoa Group and lower Bambui Group (Sete Lagoas Formation) have been founded at the occidental border of the Sao Francisco craton. These units have been separated by the Sturtian glaciation, identified by Jequitai Formation, but in some localities the glacial record is absent and is difficult to separate these two carbonates units. In this paper two sections with a good stratigraphic control have been chosen to find C, O and Sr isotopic values to have tools for the correlations. Carbonates of the Paranoa Group present a trend of positive {delta}{sup 13}C{sub PDB} varying between +0.8 e +2.7 %o, of {delta}{sup 18}O{sub PDB} varying between -9.0 e -4.7 %o and {sup 87}Sr/{sup 86}Sr ranging from 0.7063 to 0.7068. The diamictite sample of Jequitai Formation has {delta}{sup 13}C{sub PDB} values of -1.8%o and {delta}{sup 18}O{sub PDB} values of -5.1%o. The cap dolomites of the Sete Lagoas Formation are associated with an extremely negative {delta}{sup 13}C{sub PDB} values between -6.0 e -3.2 %o, {delta}{sup 18}O{sub PDB} values between -9.1 e -5.3%o and high {sup 87}Sr/{sup 86}Sr ratios suggesting a radiogenic Sr isotope anomaly. Limestone and muddy-limestone above the cap dolomite still starts with extremely negative {delta}{sup 13}C{sub PDB} values (-6.0%o) and are followed by an upward trend of increasing carbon isotope values up to +9.2 %o. In the same interval the {delta}{sup 18}O{sub PDB} values ranging from -10.1%o at the base to -5.5%o in direction to the top of formation and primary {sup 87}Sr/{sup 86}Sr ratios between 0.70745 and 0.70758. The Carbon and Sr isotope data presented here reveal significant differences between carbonates from the Paranoa Group and the Bambui Group. These data developed here provides the framework for a new regional isotopic correlation model to the carbonates units of the Paranoa and Bambui groups. (author)

  5. Can a secondary isotope effect be larger than a primary?

    Science.gov (United States)

    Perrin, Charles L; Burke, Kathryn D

    2015-05-21

    Primary and secondary (18)O equilibrium isotope effects on the acidities of a variety of Brønsted and Lewis acids centered on carbon, boron, nitrogen, and phosphorus were computed by density-functional theory. For many of these acids, the secondary isotope effect was found to be larger than the primary isotope effect. This is a counterintuitive result, because the H atom that is lost is closer to the (18)O atom that is responsible for the primary isotope effect. The relative magnitudes of the isotope effects can be associated with the vibrational frequency and zero-point energy of the X═O vibrations, which are greater than those of the X-O vibrations. However, the difference between these contributions is small, and the major responsibility for the larger secondary isotope effect comes from the moment-of-inertia factor, which depends on the position of the (18)O atom relative to the principal axes of rotation. PMID:25879248

  6. Collision energy effect on the H′ + BrH (ν = 0, j = 0) → H′Br + H reaction: A quasi-classical trajectory study

    International Nuclear Information System (INIS)

    Graphical abstract: The theoretical studies of the dynamics of the exchange reaction H′ + BrH (ν = 0, j = 0) → H′Br + H reactions are presented by stereodynamics calculations with quasiclassical trajectory method. Highlights: ► The cross sections for collision energies from 0.5 to 2.0 eV are determined. ► The rotational, vibrational and translational fractions are presented. ► The repulsive character of the potential energy surface is explored. ► The alignment and the orientation of H′Br are found to be close relation to Ec. - Abstract: Theoretical studies on the dynamics of the exchange reaction H′ + BrH (ν = 0, j = 0) → H′Br + H are performed on potential energy surface (PES) (Kurosaki et al., private communication) for the ground state using the quasi-classical trajectory method. The cross sections, computed at the collision energies (Ec) of 0.5–2.0 eV, are in good agreement with the earlier quantum wave packet results. The rotational, vibrational, and translational fractions in the total energy and the vibrational distribution for the product molecule are calculated at the same collision-energy range. The results support the repulsive character of the PES. In the considered Ec range, it has little chance to occur in an indirect reaction. The alignment and orientation of the product H′Br are investigated in detail with stereodynamics. The results show that Ec can effect on both the alignment and the orientation of product.

  7. Stable-isotope composition of the water of apple juice

    International Nuclear Information System (INIS)

    By deuterium and oxygen 18 analysis, it was shown that apples' water is enriched in heavier isotopes as compared to rain water. The isotopic composition of the water of reconstituted apple juice is closed to the isotopic content of the rain water used for dilution. Thus, deuterium and oxyden 18 analysis allows a good analytical distinction between natural apple juice and reconstituted juices

  8. Large BR( h → τ μ) in the MSSM?

    Science.gov (United States)

    Aloni, Daniel; Nir, Yosef; Stamou, Emmanuel

    2016-04-01

    We study how large the rate of the lepton-flavor violating Higgs decay h → τ μ can be in the (R-parity conserving) MSSM. We make no assumptions, such as universality or alignment, about the flavor structure of the MSSM. We only assume that all couplings and, in particular, the trilinear scalar ones, are perturbative. We take into account lower bounds on the bino and slepton masses from τ → μγ and h → γγ as well as upper bounds on the trilinear scalar couplings from the requirement that the global minimum is not charge breaking. We find that in highly fine-tuned regions of parameter space, the ratio BR( h → τ μ) /BR( h → τ τ ) can be enhanced by about three orders of magnitude above the estimate from naive dimensional analysis, but still about two orders of magnitude below the present bound. Thus, if h → τ μ is experimentally established to be close to present bounds, the MSSM will be excluded.

  9. Study of 138La radioactive decays using LaBr3 scintillators

    International Nuclear Information System (INIS)

    We present a detailed investigation of the intrinsic activity of LaBr3 scintillators from the natural abundance of radioactive isotope 138La. Compared to earlier studies of lanthanum halides intrinsic activity, we gained a sharper insight by using samples of different sizes, ranging from 0.16 cm3 to 347 cm3, and by applying in our recent analysis results on the non-proportionality of scintillation response. In addition, we took advantage of the fact that LaBr3 spectrometers offer a unique opportunity, never available before, to study the characteristics of the 138La electron capture and β radioactive decays that are 2nd order unique forbidden transitions. The observed shape of the β continuum, measured down to the energy of 2 keV, is found to be different than expected from standard nuclear theory, indicating a possible underestimation of the screening effect for β energies below 75 keV.

  10. Proton induced activation of LaBr3:Ce and LaCl3:Ce

    International Nuclear Information System (INIS)

    In the framework of an assessment of lanthanum halide scintillators, such as LaBr3:Ce and LaCl3:Ce on their suitability for space based gamma-ray spectroscopy, proton induced activation of the materials has been studied. One inch scintillators were subjected to proton irradiations in the range of 60-184 MeV, where after the activation was measured. The activation was analyzed by identifying the decaying isotopes by means of gamma-ray spectroscopy and lifetime measurements using both a germanium detector and the activated scintillator itself. It was found that the dominant source of activation in the scintillators originates from the lighter elements in the materials: bromide and chloride, respectively. The activation of LaBr3:Ce manifest itself through gamma-decay, which partly leaves the volume. Activation of LaCl3:Ce originates mainly from beta decay, which is confined to the volume itself

  11. Ravintola Tallin brändi-identiteetti ja -imago

    OpenAIRE

    Hirvikoski, Mira

    2015-01-01

    Opinnäytetyöni aiheena on brändi. Brändit ovat nykyaikana oleellinen osa liiketoimintaa ja parhaimmil-laan jopa yritystensä kallisarvoisinta omaisuutta. Brändi-identiteetti on tulevaisuuden tavoite, johon yritys pyrkii. Se kertoo, millaisena yritys toivoisi ulkopuolisten tahojen, kuten asiakkaiden, näkevän sen brändin. Brändi-imago taas kuvaa sitä, millaisena yrityksen ulkopuoliset tahot näkevät sen brändin juuri tällä het-kellä. Opinnäytetyöni tavoitteena oli selvittää, miten Ravintola T...

  12. The TbBr3–LiBr binary system: Experimental thermodynamic investigation and assessment of phase diagram

    International Nuclear Information System (INIS)

    Highlights: ► DSC measurements for the (LiBr + TbBr3) system. ► congruently Li3TbBr6 and incongruently melting Li5TbBr8 compounds. ► Thermodynamic description of the liquid phase in the (LiBr + TbBr3) system. ► Assessment with a two-sublattice ionic solution model. - Abstract: DSC was used to study the phase equilibrium in the TbBr3–LiBr binary system. The results obtained provided a basis for constructing the phase diagram of this system. It exhibits two compounds: Li5TbBr8, which decomposes in the solid state at 611 K, and Li3TbBr6, which melts congruently at 785 K with the related enthalpy 59.1 kJ·mol−1. The binary LiBr–TbBr3 system was then optimized using the available experimental information on phase diagram and thermodynamic properties. A two-sub-lattice ionic solution model (Li+)P:(Br−, TbBr6−3, TbBr3)Q was adopted to describe the liquid phase. The present assessment of the binary LiBr–TbBr3 system was in good agreement with the corresponding experimental data and confirmed their consistency.

  13. Elamusturundus: riigi brändimine ja Eesti bränd / Siiri Same

    Index Scriptorium Estoniae

    Same, Siiri

    2015-01-01

    Artikli autor oma 2015. a. Tallinna Tehnikaülikoolis kaitstud doktoritööst "Conceptualization of experience marketing and country branding from a marketing management perspective" ("Elamusturunduse ja riigi brändimise kontseptualiseerimine turunduse juhtimise vaatenurgast")

  14. Isotope Spectroscopy

    CERN Document Server

    Caffau, E; Bonifacio, P; Ludwig, H -G; Monaco, L; Curto, G Lo; Kamp, I

    2013-01-01

    The measurement of isotopic ratios provides a privileged insight both into nucleosynthesis and into the mechanisms operating in stellar envelopes, such as gravitational settling. In this article, we give a few examples of how isotopic ratios can be determined from high-resolution, high-quality stellar spectra. We consider examples of the lightest elements, H and He, for which the isotopic shifts are very large and easily measurable, and examples of heavier elements for which the determination of isotopic ratios is more difficult. The presence of 6Li in the stellar atmospheres causes a subtle extra depression in the red wing of the 7Li 670.7 nm doublet which can only be detected in spectra of the highest quality. But even with the best spectra, the derived $^6$Li abundance can only be as good as the synthetic spectra used for their interpretation. It is now known that 3D non-LTE modelling of the lithium spectral line profiles is necessary to account properly for the intrinsic line asymmetry, which is produced ...

  15. Vahva ja erottuva brändi yrityksen kilpailuetuna : VihreäKeiju-brändin kuluttaja-asiakastutkimus

    OpenAIRE

    Merta, Helinä

    2011-01-01

    Brändi on kaikkien niiden mielikuvien ja tietojen summa, joita ihmisellä on jostain asiasta. Brändi syntyi 1700-luvun Amerikassa, jossa karja merkittiin polttomerkein (engl. brand), jotta jokainen erottaisi oman karjansa. Brändi tarkoittikin aluksi erilaistavaa tunnistetta tai symbolia. Nykyisin brändillä viitataan konkreettisiin ja mielikuvallisiin ominaisuuksiin, joiden avulla tuotteet erottuvat toisistaan. Brändiä rakentamalla pyritään kirkastamaan brändiin liitettyjä mielikuvia sekä er...

  16. The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

    Directory of Open Access Journals (Sweden)

    A. M. Batenburg

    2012-05-01

    very D-depleted H2 in the wet season may contribute to this phenomenon. <br>> Some of the samples have very high χ(H2 and very low δD values, which indicates a pollution effect. Aircraft engine exhaust plumes are a suspected cause, since the effect mostly occurs in samples collected close to airports, but no similar signals are found in other chemical tracers to support this. The isotopic source signature of the H2 pollution seems to be on the low end of the signature for fossil fuel burning.

  17. The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

    Directory of Open Access Journals (Sweden)

    A. M. Batenburg

    2012-01-01

    of very D-depleted H2 in the wet season may contribute to this phenomenon. <br>> Some of the samples have very high m(H2 and very low δD values, which indicates a pollution effect. Aircraft engine exhaust plumes are a suspected cause, since the effect mostly occurs in samples collected close to airports, but no similar signals are found in other chemical tracers to support this. The isotopic source signature of the H2 pollution seems to be on the low end of the signature for fossil fuel burning.

  18. Aging and mechanical properties of NR/BR blends

    Science.gov (United States)

    Chiu, Hsien-Tang; Tsai, Peir-An

    2006-02-01

    The mechanical properties and post-thermal aging properties of natural rubber (NR) and polybutadiene rubber (BR) blends at different blending ratios are investigated herein. The experimental results show that both tensile and tear strengths of NR/BR blends increase with increasing NR content. BR has a higher compression stiffness than NR. The deformation of BR is less than that of NR under the same load conditions. With regard to aging properties, both tensile stress and strain of NR/BR blends decrease after prolonged aging. In addition, the stress loss of BR is lower than that of NR, meaning that the aging resistance property of BR is superior to that of NR. Furthermore, accumulated thermal history has shifted the glass transition temperature (T g) of NR/BR blends toward lower temperatures while the loss tangent (tan δ) value increases with prolonged thermal aging.

  19. Plasmid DNA breakage by decay of DNA associated isotopes 123I and 125I

    International Nuclear Information System (INIS)

    The biological consequences of decay of DNA-associated 125I have been extensively investigated using a variety of systems. It is well established that decay of the isotope in close proximity to DNA produces a DSB with an efficiency close to 1. Much less information is available for another iodine isotope - 123I. It is a 'weaker' Auger emitter than 125I, and has much shorter half-life; 13.2 hours compared to 60 days for 125I. Cell culture studies indicate that decay of 123I is more than two times less efficient in killing V79 cells than decay of 125I, and produces from 0.45 to 0.74 DSB per decay in the cell nucleus. The Monte Carlo simulation of 123I decay and DSB induction has generated a value of 0.4 DSB per decay of incorporated isotope. We have adapted the plasmid DNA assay to compare strand breakage by decay of DNA-associated 125I and 125I, exploiting DNA minor groove binding ligand Hoechst 33258 labelled with either of these isotopes. Application of the plasmid assay to this study highlighted a range of important factors, which were taken into account to ensure a valid outcome. These factors involve the statistical implications of the nature of the breakage events (such as multiple breaks arising from a single decay event), two different sources of damage, namely internal (from DNA-associated decay events) and external (from decays occurring anywhere in solution), and consideration of the fraction of DNA-bound ligand. In our experiments, we incubated pBR322 plasmid with [125I]-iodoHoechst 33258 or with mixture of ligands labelled with 123I and 125I. The latter approach allows measurement of the ratio of probabilities of DSB formation per decay for the two isotopes, with much higher precision than determination of the individual breakage probabilities for each isotope. We obtained for the probability (per decay) of induction of DSB by the 125I-labeled ligand a value of 0.82 ± 0.05. Inclusion of DMSO as a radical scavenger, reduces this value to 0.65 ± 0

  20. Molecular elimination of Br2 in photodissociation of CH2BrC(O)Br at 248 nm using cavity ring-down absorption spectroscopy

    International Nuclear Information System (INIS)

    The primary elimination channel of bromine molecule in one-photon dissociation of CH2BrC(O)Br at 248 nm is investigated using cavity ring-down absorption spectroscopy. By means of spectral simulation, the ratio of nascent vibrational population in v = 0, 1, and 2 levels is evaluated to be 1:(0.5 ± 0.1):(0.2 ± 0.1), corresponding to a Boltzmann vibrational temperature of 581 ± 45 K. The quantum yield of the ground state Br2 elimination reaction is determined to be 0.24 ± 0.08. With the aid of ab initio potential energy calculations, the obtained Br2 fragments are anticipated to dissociate on the electronic ground state, yielding vibrationally hot Br2 products. The temperature-dependence measurements support the proposed pathway via internal conversion. For comparison, the Br2 yields are obtained analogously from CH3CHBrC(O)Br and (CH3)2CBrC(O)Br to be 0.03 and 0.06, respectively. The trend of Br2 yields among the three compounds is consistent with the branching ratio evaluation by Rice-Ramsperger-Kassel-Marcus method. However, the latter result for each molecule is smaller by an order of magnitude than the yield findings. A non-statistical pathway so-called roaming process might be an alternative to the Br2 production, and its contribution might account for the underestimate of the branching ratio calculations.

  1. BR2 Reactor: Irradiation of Fusion Materials

    International Nuclear Information System (INIS)

    In collaboration with the EFDA (European Fusion Development Agreement), SCK-CEN irradiates several materials in the BR2 reactor at different temperatures and up to different doses to study their mechanical and physical properties during and after irradiation. Those materials are candidates for the construction of different parts of the ITER fusion reactor and of the long-term DEMO (DEMOnstration) reactor. The objectives of research performed at SCK-CEN are to irradiate up to 2 dpa RAFM (Reduced Activity Ferritic Martensitic) steels joints and RAFM ODS (Oxide Dispersion Strengthening) at 300 degrees Celsius; to build and test an experimental rig to perform in-situ creep-fatigue tests under neutron irradiation and its out-pile equipment and to design a new irradiation basket to irradiate in BR2 copper/stainless steel joints and RAFM specimens with implanted helium at low dose

  2. Energy levels of HoBr 63-

    Science.gov (United States)

    Tanner, Peter A.

    1986-12-01

    The excitation, electronic absorption and luminescence spectra of cubic Cs 2NaHoBr 6 have been recorded at temperatures down to that of liquid helium. The detailed spectral analyses enable comparisons to be made of the crystal-field splittings of Russell—Saunders terms with those in Cs 2NaHoCl 6. Under intense 647.1 nm laser excitation, luminescence is observed in the neat material in the spectral region between 17800 and 21750 cm -1.

  3. Decommissioning of the BR3 PWR

    International Nuclear Information System (INIS)

    The objectives, programme and main achievements of SCK-CEN's decommissioning programme in 1997 are summarised. Particular emphasis is on the BR3 decommissioning project. In 1997, auxiliary equipment and loops were dismantled; concrete antimissile slabs were decontaminated; the radiology of the primary loop was modelled; the quality assurance procedure for dismantling loops and equipment were implemented; a method for the dismantling of the reactor pressure vessel was selected; and contaminated thermal insulation of the primary loop containing asbestos was removed

  4. Decommissioning of the BR3 PWR

    International Nuclear Information System (INIS)

    The dismantling and the decommissioning of nuclear installations at the end of their life-cycle is a new challenge to the nuclear industry. Different techniques and procedures for the dismantling of a nuclear power plant on an existing installation, the BR-3 pressurized-water reactor, are described. The scientific program, objectives, achievements in this research area at the Belgian Nuclear Research Centre SCK-CEN for 1997 are summarized

  5. SOFC brændselsceller i et intelligent elnet

    OpenAIRE

    Hjelm, Johan

    2015-01-01

    SOFC brændselsceller kan være med til at skabe balance i elnettet i takt med at elproduktionen i stigende grad baseres på sol og vind. Brændselscellerne kan kobles til naturgasnettet og på sigt bruge forskellige former for VE-gasser som brændstof.

  6. BR2 reactor: medical and industrial applications

    International Nuclear Information System (INIS)

    The radioisotopes are produced for various applications in the nuclear medicine (diagnostic, therapy, palliation of metastatic bone pain), industry (radiography of welds, ...), agriculture (radiotracers, ...) and basic research. Due to the availability of high neutron fluxes (thermal neutron flux up to 1015 n/cm2.s), the BR2 reactor is considered as a major facility through its contribution for a continuous supply of products such 99Mo (99mTc), 131I, 133Xe, 192Ir, 186Re, 153Sm, 90Y, 32P, 188W (188Re), 203Hg, 82Br, 41Ar, 125I, 177Lu,89Sr, 60Co, 169Yb, 147Nd, and others. Neutron Transmutation Doped (NTD) silicon is produced for the semiconductor industry in the SIDONIE (Silicon Doping by Neutron Irradiation Experiment) facility, which is designed to continuously rotate and traverse the silicon through the neutron flux. These combined movements produce exceptional dopant homogeneity in batches of silicon measuring 4 and 5-inches in diameter by up to 750 mm in length. The main objectives of work performed were to provide a reliable and qualitative supply of radioisotopes and NTD-silicon to the customers in accordance with a quality system that has been certified to the requirements of the EN ISO 9001: 2000. This new Quality System Certificate has been obtained in November 2003 for the Production of radioisotopes for medical and industrial applications and the Production of Neutron Transmutation Doped (NTD) Silicon in the BR2 reactor

  7. Energy transfer in CsCdBr3 : Nd3+ system

    OpenAIRE

    Barthem, R. B.; Buisson, R.; Vial, J.C.; Chaminade, Jean-Pierre

    1985-01-01

    CsCdBr3 doped with trivalent rare earths is an attractive system to study energy transfer phenomena. Trivalent rare earths substituted to Cd2+ can be associated in pairs close to a Cd2+ vacancy. In these systems, cooperative relaxation (up conversion and cross relaxation) are very efficient. A comparaison between Nd3+ absorption and excitation spectra shows that the great majority of Nd3+ are associated in one kind of pairs even in low doping crystals.

  8. Three-dimensional intramolecular dynamics: Internal rotation of (CH{sub 3}){sub 3}GeBr

    Energy Technology Data Exchange (ETDEWEB)

    Schnell, Melanie [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany)], E-mail: schnell@fhi-berlin.mpg.de; Grabow, Jens-Uwe [Gottfried-Wilhelm-Leibniz-Universitaet Hannover, Institut fuer Physikalische Chemie, Lehrgebiet A, Callinstrasse 3-3a, D-30167 Hannover (Germany)

    2008-01-29

    The microwave spectra of (CH{sub 3}){sub 3}{sup 74}Ge{sup 79}Br and its isotopologues (CH{sub 3}){sub 3}{sup 72}Ge{sup 79}Br and (CH{sub 3}){sub 3}{sup 74}Ge{sup 81}Br have been studied in the frequency range from 2.4-20 GHz revealing the complex internal dynamics of this organometallic molecule with three internal rotors. The assignment of the complex spectrum has been facilitated by permutation-inversion theory - the appropriate molecular symmetry group is G{sub 162}. The V{sub 3} barrier to internal rotation is determined to be 4.783(12) kJ/mol. An analysis of the bromine quadrupole coupling yields the description of the Ge-Br and the Ge-C bonding characters. From this analysis we find that the bromine atom has a positive partial charge resulting from {pi}-backbonding of the bromine towards germanium. From isotopic substitution, the Ge-Br bond distance could be determined to 2.34589(21) A.

  9. Dry storage of the BR3 spent fuel in the Castor BR3 cask

    Energy Technology Data Exchange (ETDEWEB)

    Ooms, L.; Massaut, V.; Noynaert, L. [SCK/CEN, B-2400 Mol (Belgium); Braeckeveldt, M. [Niras/Ondraf, B-1210 Brussels (Belgium)

    2001-07-01

    Twenty-five years of operation has resulted in an inventory of spent fuel with a wide variety in the BR3 nuclear pilot power plant. Studies were launched to evaluate all possible solutions for the BR3 experimental and 'exotic' spent fuel, i.e. reprocessing, dry storage in containers and dry storage in canisters. For the BR3 spent fuel the interim dry storage in Castor BR3 containers was chosen. The present paper describes in a first part the history and characteristics of the spent fuel. A second part handles with the different options, which were studied for the spent fuel evacuation. The last part focuses on the spent fuel preparation and the production of the Castor BR3. This project allowed the SCK-CEN to build up an important know-how in the field of spent fuel management, especially the management of research reactor fuel, which is very specific and not comparable with spent fuel of commercial nuclear power plants. (author)

  10. Communication: An unusual halogen-bonding motif: the LiBr···BrF dimer as a model system.

    Science.gov (United States)

    McDowell, Sean A C; Joseph, Jerelle A

    2012-11-01

    A stable complex, LiBr···BrF, is predicted in which the negative Br atom of LiBr is anchored to the Br atom of BrF by a halogen bond, while the positively charged Li atom interacts with the lone pair electron density on the Br atom of BrF in a direction roughly perpendicular to the halogen bond. As far as we are aware, this is the first reported instance of an atom of one diatomic molecule (Br of BrF) being bonded to two different, oppositely charged atoms (Li and Br) of another diatomic molecule (LiBr). Other less stable dimers of LiBr and BrF were predicted and compared with this novel complex. PMID:23145710

  11. Magnetic ordering in the erbium honey comb lattices of ErX3 (X = Cl, Br,

    International Nuclear Information System (INIS)

    Complete text of publication follows. Unusual 2-D and 3-D magnetic ordering phenomena have been observed in the insulating, transparent erbium trihalides ErX3 (X = Cl, Br, I) in the mini Kelvin temperature range. The layer-type crystal structures of ErCl3 (AlCl3 type structure) and ErBr3/ErI3 (BiI3 type structure) are closely related. All three compounds show a new type of 2 sublattice 120 deg antiferromagnetic order in the erbium honey comb layers with an infinite rotational degeneracy. The magnetic structures were determined by powder and single crystal neutron diffraction. ErCl3 shows a transition to 3-D magnetic order at 350 mK with a k-vector of (2/3, 0, -1/12). ErBr3 and ErI3 display short-range 2-D magnetic order from 400 mK to several Kelvin, longrange 2-D order between 280 mK and 400 mK, and short-range 3-D order below 280 mK with a correlation length of 15 A and k = (1/3, 1/3, 0). The differences between ErCl3 and ErBr3/ErI3 are due to different geometrical layer stackings. For ErBr3/ErI3 a threefold ambiguity in the magnetic layer stacking causes the disorder along the c-axis. The ordered magnetic moments at saturation increase from 3.3 to 4.7 and 5.5 μB/Er3+ for ErCl3, ErBr3 and ErI3, respectively. This is the first report on magnetic structures of layer-type rare-earth trihalides. (author)

  12. Vaatemerkin brändin vaikutus vaatteiden ostoon

    OpenAIRE

    Orkamaa, Miro

    2014-01-01

    Opinnäytetyöni aiheena on tutkia, kuinka vaatemerkin brändi vaikuttaa vaatteiden ostamiseen Kemi-Tornion ammattikorkeakoulun opiskelijoiden keskuudessa. Opinnäytetyössäni pohdin kuluttajien ostokäyttäytymistä, itse ostoprosessia sekä brändiä, brändin merkitystä nyky-yhteiskunnassa ja brändikritiikkiä. Otan esimerkkejä brändeistä, jotka liittyvät vaateteollisuuteen ja ovat tunnettuja merkkejä. Tutkimusta varten suoritin kyselyn, jonka tavoitteena oli selvittää, kuinka paljon vaatemerkki j...

  13. Nitrogen isotope dynamics and fractionation during sedimentary denitrification in Boknis Eck, Baltic Sea

    Directory of Open Access Journals (Sweden)

    K. Dähnke

    2013-01-01

    Full Text Available The global marine nitrogen cycle is constrained by nitrogen fixation as a source of reactive nitrogen, and denitrification or anammox on the sink side. These processes with their respective isotope effects set the marine nitrate 15N-isotope value (δ15N to a relatively constant average of 5‰. This value can be used to better assess the magnitude of these sources and sink terms, but the underlying assumption is that sedimentary denitrification and anammox, processes responsible for approximately one third of global nitrogen removal, have little to no isotope effect on nitrate in the water column. <br>> We investigated the isotope fractionation in sediment incubations, measuring net denitrification and nitrogen and oxygen stable isotope fractionation in surface sediments from the coastal Baltic Sea (Boknis Eck, Northern Germany, a site with seasonal hypoxia and dynamic nitrogen turnover. <br>> We found tremendously high denitrification rates, and regardless of current paradigms assuming little fractionation during sediment denitrification, we measured fractionation factors of 18.9‰ for nitrogen and 15.8‰ for oxygen in nitrate. While the input of nitrate to the water column remains speculative, these results challenge the current view of fractionation during sedimentary denitrification and imply that nitrogen budget calculations may need to consider this variability, as both preferential uptake of light nitrate and release of the remaining heavy fraction can significantly alter water column nitrate isotope vales at the sediment-water interface.

  14. Enhanced tropospheric BrO over Antarctic sea ice in mid winter observed by MAX-DOAS on board the research vessel Polarstern

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2007-06-01

    Full Text Available We present Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS observations of tropospheric BrO carried out on board the German research vessel Polarstern during the Antarctic winter 2006. Polarstern entered the area of first year sea ice around Antarctica on 24 June 2006 and stayed within this area until 15 August 2006. For the period when the ship cruised inside the first year sea ice belt, enhanced BrO concentrations were almost continuously observed. Outside the first year sea ice belt, typically low BrO concentrations were found. Based on back trajectory calculations we find a positive correlation between the observed BrO differential slant column densities (ΔSCDs and the duration for which the air masses had been in contact with the sea ice surface prior to the measurement. While we can not completely rule out that in several cases the highest BrO concentrations might be located close to the ground, our observations indicate that the maximum BrO concentrations might typically exist in a (possibly extended layer around the upper edge of the boundary layer. Besides the effect of a decreasing pH of sea salt aerosol with altitude and therefore an increase of BrO with height, this finding might be also related to vertical mixing of air from the free troposphere with the boundary layer, probably caused by convection over the warm ocean surface at polynyas and cracks in the ice. Strong vertical gradients of BrO and O3 could also explain why we found enhanced BrO levels almost continuously for the observations within the sea ice. Based on our estimated BrO profiles we derive BrO mixing ratios of several ten ppt, which is slightly higher than many existing observations. Our observations indicate that enhanced BrO concentrations around Antarctica exist about one month earlier than observed by satellite instruments. From detailed radiative transfer simulations we find that MAX-DOAS observations are up to about one order of

  15. In situ production of brGDGTs in Lake Lugano

    Science.gov (United States)

    Weber, Yuki; Hopmans, Ellen C.; Schubert, Carsten; Simona, Marco; Sinninghe Damsté, Jaap S.; Lehmann, Moritz F.; Niemann, Helge

    2015-04-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that commonly occur in soils, as well as in sediments and suspended particulate matter (SPM) of lakes. The distribution of brGDGTs is related with temperature and pH, allowing their use as proxy indicators for the reconstruction of past climatic and environmental conditions. While transfer functions are well-established for brGDGTs derived from soils, still little is known about the links between the composition of aquatically produced brGDGTs and environmental parameters. Also the identity, ecology and carbon substrate of the aquatic source organisms are mostly unknown. We analyzed brGDGTs in the core- and intact polar lipid fractions of SPM from eutrophic Lake Lugano (Switzerland) using an advanced HPLC-MS method, capable of distinguishing between 5 methyl brGDGTs and the recently discovered 6 methyl brGDGT isomers. Our data show large variations in both the concentration and the relative abundances of brGDGTs throughout the water column, with most pronounced compositional changes right at the oxic/anoxic interface: A novel brGDGT isomer, which we discovered recently for the first time in sediments of another Swiss lake (Lake Hinterburg) and which is probably intrinsic to lacustrine environments, occurs exclusively in the anoxic monimolimnion but neither in the oxic mixolimnion nor in catchments soils of Lake Lugano. Furthermore, the brGDGT distribution in the lake's mixolimnion also differs from that in the catchment. This indicates that the brGDGTs present in the water column are dominantly autochthonous and that several distinct brGDGT-producing bacterial communities with different redox requirements can co-exist within the same lake system. Hence, our results provide new insights into the sources and distribution of brGDGTs in lacustrine environments, with important implications for the use of brGDGT-based proxies in paleolimnological studies.

  16. Influence of methoxy-substituents on the strength of BrBr type II halogen bonds in bromobenzoic acid

    Science.gov (United States)

    Raffo, Pablo A.; Marcolongo, Juan P.; Funes, Alejandro V.; Slep, Leonardo D.; Baggio, Ricardo F.; Cukiernik, Fabio D.

    2016-03-01

    4-bromo-3,5-di(methoxy)benzoic acid (I) crystallizes in the monoclinic C2/c space group, a = 22.3405 (6) Å, b = 4.85142 (14) Å, c = 18.1583 (5) Å, β = 93.086 (2)°. The crystal structure shows head-to-head dimeric units linked via type II BrBr interactions as well as Br … π and weak H-bonding interactions. The whole structure exhibits features similar to those of the parent 4-bromobenzoic acid (II), most notably the overall geometrical features involved in the BrBr type II interactions. Both structures display comparable C-BrBr angles (θ1 = 98.3 and 91.6° and θ2 = 163.0 and 163.5° for (I) and (II) respectively), but the BrBr distance is significantly shorter in (I) (3.58 Å) than in (II) (3.81 Å). QM computations provide the magnitude of the intermolecular interactions present in both (I) and (II), and allow disclosing the individual covalent and electrostatic contributions to the Br⋯Br halogen bond in terms of interaction energies, electrostatic potentials, and a molecular orbital (MO) analysis.

  17. Randnahe Kopfbolzen im Brückenbau

    OpenAIRE

    Raichle, Jochen

    2015-01-01

    Kopfbolzen stellen ein bewährtes und wirtschaftliches Verbindungsmittel zwischen einem Bauteil aus Stahl und einem Bauteil aus Beton dar. Die randnahen Kopfbolzen weisen gegenüber dem häufigen Fall der randfernen Kopfbolzen einen geringen Abstand der Bolzenachse zur Betonoberfläche auf. Dadurch ergibt sich bei randnahen Kopfbolzen gegenüber randfernen Kopfbolzen ein geändertes Trag- und Ermüdungsverhalten der Verbundfuge, das insbesondere in Hinblick auf Ermüdung und damit der Anwendung im Br...

  18. Present status of TCA/BR Tokamak

    International Nuclear Information System (INIS)

    The TCA tokamak is being partially reconstructed and reassembled in the Plasma Laboratory of The University of Sao Paulo, and afterwards it will be named TCA/BR. The first discharges are expected by June/July of next year. The main scientific objectives envisaged for the machine are: Alfven wave heating and current drive, confinement improvement, disruptions and turbulence. In this paper we also describe: (i) the present status of the project; (ii) the diagnostic system; (iii) the control and data acquisition system; (iv) the RF system for the excitation of Alfven waves, that are being developed, and also the results of predictive transport simulations of its performance. (author)

  19. Microhardness studies on as-grown faces of NaClO3 and NaBrO3 crystals

    Indian Academy of Sciences (India)

    K Kishan Rao; V Surender; B Saritha Rani

    2002-12-01

    Single crystals of NaClO3 and NaBrO3 are grown from their aqueous solutions at a constant temperature of 35°C by slow evaporation by using good quality seed crystals. Systematic microhardness studies are made on as-grown faces of these crystals at various loads. Typical cracks are observed at the corners of the impressions in NaClO3 whereas in addition to the cracks at the corners microcracks also appeared in NaBrO3 crystals around the impressions. The impressions formed in NaBrO3 are not very clear as in NaClO3, a possible mechanism for it is discussed. The work hardening index number () for both these crystals is around 1.6 suggesting that these are moderately harder samples. The hardness studies point out that NaBrO3 is harder than NaClO3 ( ≈ 100 kg/mm2), this could be due to strong inter ionic forces acting between Na–Br in NaBrO3 crystals. Using Gilman’s empirical relation, hardness values are calculated from the values of elastic constants (44) and are found to be close to the experimental results.

  20. Nickel isotopes and methanogens

    Science.gov (United States)

    Neubeck, A.; Ivarsson, M.

    2013-12-01

    Methanogens require Ni for their growth and as a consequence the microbial fractionation of Ni isotopes can be used as a biomarker for activity of methanogenic communities1. Anaerobic laboratory experiments was performed using methanogens to investigate methanogenic growth in a modified nutrient media2 with olivine Fo91 (5g/l) added as an additional mineral nutrient source and as the only H2 provider. One of the investigated methanogens showed an increased growth in the experiments with added olivine. There were also a close relationship between the mobilized Ni and the growth of the methanogen. Ni is an element that previously has been neglected in the study of fossilized microorganisms and their interaction with mineral substrates and, thus, there are no records or published data of Ni in association with microfossils. However, we have detected enrichments of Ni in fossilized microorganisms and ichno-fossils, respectively, from three separate locations. Ni is not present in the host rock in any of the samples. Thus, Ni is present in association with fossilized microorganisms from environments and more extensive analysis is required to understand the magnitude, uptake, preservation and fractionation of Ni in microfossils. In order to analyze Ni isotope fractionation from microbe-mineral interaction, we plan to use a high-resolution Laser-Ablation Time-of-Flight Mass Spectrometer (LMS)3. In situ profile ablation will provide detailed and localized data on fractionation patterns between microfossils and their host rock. Also, this technique will allow us to identify the change in Ni isotopic fractionation in rock samples caused by abiotic and biogenic processes in a faster and easier way and with less risk for contamination compared to the wet chemistry analyses of Ni isotopes. 1. Cameron, V., Vance, D., Archer, C. & House, C. H. A biomarker based on the stable isotopes of nickel. Proceedings of the National Academy of Sciences 106, 10944-10948 (2009). 2. Schn

  1. Ozone Depletion Potential of CH3Br. Appendix H

    Science.gov (United States)

    Ko, Malcolm K. W.; Sze, Nien Dak; Scott, Courtney; Rodriguez, Jose M.; Weisenstein, Debra K.; Sander, Stanley P.

    1998-01-01

    The ozone depletion potential (ODP) of methyl bromide (CH3Br) can be determined by combining the model-calculated bromine efficiency factor (BEF) for CH3Br and its atmospheric lifetime. This paper examines how changes in several key kinetic data affect BEF. The key reactions highlighted in this study include the reaction of BrO + HO2, the absorption cross section of HOBr, the absorption cross section and the photolysis products of BrONO2, and the heterogeneous conversion of BrONO2 to HOBr and HNO3 on aerosol particles. By combining the calculated BEF with the latest estimate of 0.7 year for the atmospheric lifetime of CH3Br, the likely value of ODP for CH3Br is 0.39. The model-calculated concentration of HBr (approx. 0.3 pptv) in the lower stratosphere is substantially smaller than the reported measured value of about 1 pptv. Recent publications suggested models can reproduce the measured value if one assumes a yield for HBr from the reaction of BrO + OH or from the reaction of BrO + HO2. Although the evaluation concluded any substantial yield of HBr from BrO + HO2 is unlikely, for completeness, we calculate the effects of these assumed yields on BEF for CH3Br. Our calculations show that the effects are minimal: practically no impact for an assumed 1.3% yield of HBr from BrO + OH and 10% smaller for an assumed 0.6% yield from BrO + HO2.

  2. BR2 reactor: medical and industrial applications

    International Nuclear Information System (INIS)

    The radioisotopes are produced for various applications in the nuclear medicine (diagnostic, therapy, palliation of metastatic bone pain), industry (radiography of welds ...), agriculture (radiotracers ...) and basic research. Due to the availability of high neutron fluxes (thermal neutron flux up to 1015 n/cm2.s), the BR2 reactor is considered as a major facility through its contribution for a continuous supply of products such as 99Mo (99mTc), 131I, 133Xe, 192Ir, 186Re, 90Sm, 131Y, 32P, 188W (188Re), 203Hg, 82Br, 41Ar, 125I, 177Lu, 89Sr, 60Co, 169Yb, 147Nd, ... Neutron Transmutation Doped (NTD) silicon is produced for the semiconductor industry in the SIDONIE (Silicon Doping by Neutron Irradiation Experiment) facility, which is designed to continuously rotate and traverse the silicon through the neutron flux. These combined movements produce exceptional dopant homogeneity in batches of silicon measuring 4 and 5-inches in diameter by up to 750 mm in length

  3. H 2O and halogen (F, Cl, Br) behaviour during shallow magma degassing processes

    Science.gov (United States)

    Villemant, Benoı̂t; Boudon, Georges

    1999-05-01

    Degassing paths of silicic H 2O-rich magmas during explosive Plinian and dome-forming eruptions may be represented in simple evolution diagrams relating the residual volatile content of the melt to the volume ratio of gas over melt ( Vg/ Vl). These parameters are measurable in erupted magma fragments. They are used for interpreting the H 2O and halogen contents determined in a series of variously degassed volcanic clasts from the 650 y. B.P. eruption at Mt. Pelée (Martinique, FWI) which is characterized by the succession of a dome extrusion and a Plinian activity. H 2O degassing of Plinian pumice clasts are modeled by an equilibrium closed system evolution which allows to calculate the partition coefficients of halogen between the aqueous fluid and the rhyolitic melt d v-li: ≪1 for F, 10±1.5 for Cl and 3.7±1 for Br, at around 900°C. The strong increase of the dv-li values of Cl and Br during dome extrusion is explained by an open system degassing model with a simultaneous crystallization of the melt. Some significant Br enrichments relative to Cl in dome fragments are attributed to interactions with an hydrothermal fluid close to seawater in composition. The models allow calculation of Cl and Br contents of aqueous fluids generated by the different degassing paths: Cl contents are ≈0.5 mol/l for closed system evolution and vary between 0.2 and 1 mol/l during open system evolutions. These fluids are able to extract significant amounts of chloride complexed metals and silica from the magma during dome forming eruptions. They also may generate mineralization of the wall rocks or the rising dome itself (e.g. silica precipitation) which may seal the volcanic system and be responsible for the dome explosivity and the transition from dome-forming to Plinian eruptive style. The Cl/Br ratio of initial melts of P1 eruption (≈250) is much lower than the basaltic and exospheric ratios (≈400), suggesting that strong Cl-Br fractionation may occur during the

  4. Brändi ja sen kehittäminen : Bränditutkimus ja brändinkehittämisehdotuksia kauppakeskus Elolle

    OpenAIRE

    Kumanto, Sofia

    2015-01-01

    Tämä työn tarkoituksena oli tutkia kauppakeskus Elon asiakkaiden brändimielikuvaa Elosta ja vastauksien perusteella koota brändinkehittämisehdotuksia. Tavoitteena on käyttää näitä tuloksia lisäämään kauppakeskus Elon johdon tietoa Elon brändistä heidän asiakkaiden näkökulmasta. Lisäksi tavoitteena on auttaa tämän tiedon ja työn sisältämien brändikehittämisehdotuksien pohjalta kehittämään Elon brändiä ja näin saada houkuteltua lisää asiakkaita kauppakeskukseen. Johdannossa esitellään kaup...

  5. Isotopic heterogeneity of East Antarctic mantle

    International Nuclear Information System (INIS)

    Isotopic heterogeneity of deep garnet-bearing mantle xenolytes of East Antarctics is studied to analyze the mechanisms of geochemical heterogeneity occurrence in the Earth mantle. Analysis of isotope data for the system 143Nd/144Nd - Sm/Nd permitted ascertaining the time of the last thermal impact on the mantle material (108-35 bill. years) for certain nodules, which is close to the age of ultra base alkali magmatism intrusion

  6. The origin of branched GDGTs in lake environments: Tracing allochthonous and autochthonous sources using compound-specific carbon isotope analysis

    Science.gov (United States)

    Weber, Yuki; De Jonge, Cindy; Hopmans, Ellen C.; Sinninghe Damsté, Jaap S.; Gilli, Adrian; Lehmann, Moritz F.; Niemann, Helge

    2015-04-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that are ubiquitous in soils and peat, as well as in sediments and suspended particulate matter (SPM) of lakes, rivers and coastal marine environments. It has been found that the relative distribution of brGDGTs changes systematically with ambient temperature and pH, making them promising proxy indicators for paleoclimatic reconstructions in sedimentary archives. In lacustrine deposits, it was initially assumed that brGDGTs mainly originate from allochthonous soil organic matter, thus reflecting the integrated mean annual air temperature (MAAT) within the watershed. Most recent research, however, strongly suggest that the brGDGTs used for paleo-thermometry can also be produced in situ within the lake system, offsetting the temperature-brGDGT relationships commonly known from soils. Until now, disentangling the relative contribution of allochthonous versus autochthonous brGDGT sources in lacustrine sediments was impossible, complicating the use of brGDGTs for quantitative paleotemperature reconstructions. We recently discovered a novel brGDGT isomer with a strongly 13C-depleted carbon isotope composition of about 46.6 o in sediments of a small eutrophic Alpine lake (Lake Hinterburg, Switzerland), which was not present in soils collected from the catchment. Furthermore, all other major brGDGTs in the sediment uniformly displayed δ13C values of about 43 o strongly contrasting the C-isotopic composition of brGDGTs from catchment soils (ca. 27 ). These findings raise two prime questions: (1) Are lake-derived brGDGTs generally more depleted in 13C with respect to their allochthonous counterparts? (2) Does the δ13C of sedimentary brGDGTs serve as a reliable indicator for lacustrine in situ production of brGDGTs? To address these questions, we determined the 13C content of brGDGTs in surface sediments from various lakes across the Swiss Alps by CG-IRMS analysis of their alkyl chains

  7. Brändi mielikuvien luojana : Case:IKU

    OpenAIRE

    Perkiö, Markus

    2012-01-01

    Brändi terminä on yleistynyt puhekielessä viimeisten vuosikymmenien aikana. Brändiä käytetään kuvaamaan esineitä, asioita, yrityksiä, ihmisiä tai ideologiaa. Tässä opinnäytetyössä perehdyttiin brändiin ilmiönä, brändin luomiseen sekä sen erottumiseen kilpailijoistaan. Opinnäytetyössä tarkasteltiin brändiä työkaluna uuden artistin esille tuomisessa kohderyhmälleen sekä suurelle yleisölle. Vaikka brändi termiä käytetään hyvin laajasti puhekielessä, se usein liitetään virheellisesti johonkin...

  8. Yrityksen brändi-imago ja -identiteetti

    OpenAIRE

    Anttonen, Jaakko

    2008-01-01

    Tämä opinnäytetyö käsittelee brändiä, brändi-imagoa ja -identiteettiä. Opinnäytetyö tehtiin Viikko-Häme Oy:n toimeksiantona. Opinnäytetyön tutkimusongelma oli selvittää, millaisia sanomalehti Viikko-Hämeen tämänhetkiset brändi-imago ja brändi-identiteetti ovat ja miten niitä voisi kehittää. Brändi on yritys, tuote tai palvelu, jolla on jonkinlaista lisäarvoa kuluttajalle, minkä vuoksi se erottuu edukseen markkinoilla. Vahva ja tunnettu brändi herättää kuluttajassa luottamusta ja on näin lupau...

  9. SOFC brændselsceller i et intelligent elnet

    DEFF Research Database (Denmark)

    Hjelm, Johan

    2015-01-01

    SOFC brændselsceller kan være med til at skabe balance i elnettet i takt med at elproduktionen i stigende grad baseres på sol og vind. Brændselscellerne kan kobles til naturgasnettet og på sigt bruge forskellige former for VE-gasser som brændstof.......SOFC brændselsceller kan være med til at skabe balance i elnettet i takt med at elproduktionen i stigende grad baseres på sol og vind. Brændselscellerne kan kobles til naturgasnettet og på sigt bruge forskellige former for VE-gasser som brændstof....

  10. Iron isotope systematics of the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Lesher, Charles; Lundstrom, C.C.; Barfod, Gry;

    The early Eocene Skaergaard intrusion, central east Greenland, is one of the most thoroughly studied layered mafic intrusions on Earth and an exceptional example of (near) closed-system magmatic differentiation. The Skaergaard intrusion is ideally suited to test models of closed-system fractional....... Forward modeling of closed system fractional crystallization constrained by cumulate volumes, whole rock and mineral compositions, mineral modes and independent constraints on Fe isotope fractionation factors account for the stratigraphic relations, except during the final stages of differentiation of...... crystallization on non-traditional stable isotope systems, particularly iron. FeTi oxide minerals (titanomagnetite and ilmenite) appear after ~60% of the magma had solidified. This was a significant event affecting the liquid line of descent and potentially accompanied by iron isotope fractionation. Here we...

  11. Determination of isotopic shift for some compounds having stable isotopic composition using FTIR technique

    International Nuclear Information System (INIS)

    A new route has been devised, leading to the production of VOX3 molecules where X = F, Br and I by an on-line process using vanadium oxytrichloride, VOCl3 as a starting compound passed over the following heated salts NaF, KBr and KI at 375, 700, and 550 Centigrades, respectively. The products have been characterized by the IR spectra of their vapors. The low resolution gas phase on-line Fourier transform infrared spectra reported for the first time show strong bands, with PQR type structure, centered at 1058, 1035, 1030 and 1025 cm-1 assigned to the ν1(a1), the O = V stretching fundamental mode of VOF3, COCl3, VOBr3 and VOI3 respectively. A new route has been devised, leading to the production of phosphorus thiotrihalides SPX3 where X = F, Br and I by an on-line process using phosphorus thio trichloride, SPCl3 as starting compound passed over the following heated salts NaF, KBr and KI at 530, 800, and 440 Centigrades, respectively. The products have been characterized by their IR spectra, showing bands with PQR type structure, centered at 985, 762, 744 and 715 cm-1. These bands are assigned to ν1(a1), the S = P stretching fundamental modes of SPF3, SPCl3, SPBr3 and SPI3, respectively. Isotopic shifts of the following groups P81-Br, P97-Br, P81-Br, P79-Br, P37-Cl, P35-Cl3, FP34S, FP32S, 34S=P, 32S = PF3, 34S = PF3 were determined. (author)

  12. Corrosion inhibition performance of a ionic liquid surfactant Br

    OpenAIRE

    Jing LIU; Dishun ZHAO; LIU, RAN; Wang, Ming; Peibing REN

    2016-01-01

    In order to study the novel green organic mercury-substituting inhibitors, the ionic liquid surfactant 1-methyl-3-dodecyl imidazole bromide ( Br) is synthesized with N-methyl imidazole and 1-bromodecane as raw materials. The corrosion inhibition of Br for zinc in zinc-manganese batteries is investigated using electrochemical methods and weight loss methods. The results show that corrosion inhibition efficiency increases with the increase of the concentration of Br, and when the concentration ...

  13. Brüssel Euroopa pealinnaks? / Ülar Mark

    Index Scriptorium Estoniae

    Mark, Ülar, 1968-

    2009-01-01

    Brüsseli Euroopa kvartali planeerimisvõistlusest, mille peakorraldaja oli Brüsseli pealinna piirkond koos Brüsseli linna ja Euroopa Komisjoniga. Eestist osales žüriis arhitekt Ülar Mark. Meeskonna Atelier Christian de Portzamparc võidutööst ja teiste teise vooru pääsenud nelja meeskonna (JDS / Julien De Smedt Architects, OMA / Office for Metropolitan Architecture, Xaveer De Geyter Architect, Fletcher Priest Architects) töödest

  14. Solid-liquid equilibria in the systems ClF5-BF3 and BrF5-BF3

    International Nuclear Information System (INIS)

    The method of differential thermal analysis has been used to investigate solid-liquid equilibria in the systems ClF5-BF3 and BrF5-BF3 in the whole range of concent-- rations of components. No formation of chemical compounds is found. BrF5-BF3 system refers to the series of simple systems of the eutectic type and is characterized by eutectics depleted in bromine pentafluoride content (less than 5 mol. %) with the melting temperature close to melting temperature of pure boron trifluoride. In the ClF5-BF3 system components are mutually insoluble in both liquid and solid states

  15. Isotopic geochemistry at Wairakei

    International Nuclear Information System (INIS)

    Deuterium measurements on geothermal water at Wairakei are consistent with the water being derived from rainfall which has percolated down from the surface. The oxygen-18 content, however, is enriched compared to average rainfall. This 18O shift is due to isotopic exchange between water and rock at greater-than-explored depths. The magnitude of the shift implied that the mass ration (W/R) of water that has passed through the system (W) to the rock it has exchanged with (R) is about 1 assuming open (i.e. single-pass) conditions. (The ratio is about 2 if it has been a closed system, but this is thought to be less likely). The residence time of water underground cannot be determined from tritium and carbon-14 measurements at present, but arguments based on the argon isotope and deuterium contents suggest mean residence times of a few tens of thousand years. The water-rock ratio and large natural outflow of thermal water prior to exploitation are consistent with this. The 18O content of the water has changed only slightly, and the D content not at all, during exploitation at Wairakei (measurements from 1963, 1974 and 1981). An initial tendency for the 18O to increase because of steam loss (also shown more clearly by chloride), has been followed by decrease of 18O (and chloride) because of dilution with infiltrating near-surface water in parts of the field

  16. Brändin rakentaminen : case Dressing Mimia

    OpenAIRE

    Rinne, Helena

    2011-01-01

    Opinnäytetyö käsittelee sitä miten brändi rakennetaan ja mistä elementeistä brändikuva muodostuu. Tutkimuskohteena oli Dressing Mimia -tapahtuman brändikuva. Dressing Mimia -tapahtuma on poikkitaiteellinen muotinäytös ja cocktailtilaisuus, joka järjestetään kerran vuodessa Turussa. Työn tavoitteena oli selvittää millaisia mielikuvia tapahtuman asiakkailla on tapahtumasta sekä saada taustatietoa tapahtumassa kävijöistä. Tulosten perusteella voidaan kehittää Dressing Mimian brändiarvoa ja koota...

  17. Brändin kirkastaminen - esimerkki Aleksanterin teatteri

    OpenAIRE

    Lautamo, Jussi

    2011-01-01

    Laurea-ammattikorkeakoulu Tiivistelmä Laurea Leppävaara Palvelujen tuottaminen ja johtaminen Lautamo, Jussi Brändin kirkastaminen – esimerkki Aleksanterin teatteri Vuosi 2011 Sivumäärä 57 Yrityksen brändi ja sen rakentaminen ovat tänä päivänä asioita, joita menestyvä yritys ei voi jättää huomioimatta. Yrityksen brändin määritteleminen ja sen esiintuominen voivat olla ratkaisevia asioita yrityksen menestyksen kannalta. Brändinsä kautta yritys edustaa itseään markki...

  18. Kvinnors upplevelser av att leva med bröstcancer

    OpenAIRE

    Music, Sanela

    2010-01-01

    Bakgrund: Bröstcancer utgör en tredjedel av all cancer som kvinnor drabbas av. Tidigare studier indikerar att kvinnor upplever mycket starka känslor kring sjukdomen bröstcancer och att de har drabbats av den. Tanken av att förlora ett bröst är en av punkterna som bringar mycket ångest och lidande. Syfte: Syftet med studien är att belysa kvinnors upplevelser av att leva med bröstcancer. Metod: En litteraturstudie med självbiografiska böcker har utförts. Studiens syfte har besvarats genom att t...

  19. Synthesis and structural characterization of luminescent inorganic materials of the type CS2NaErBr6 and CS2NaHoBr6

    International Nuclear Information System (INIS)

    The synthesis and structural characterization is described of two luminescent materials, with technological [1] and spectroscopic [2] interest, whose crystallographic charts have not been published in the literature. The synthesis of both systems: Cs2NaErBr6 and CS2NaHoBr6, was done using solid state reactions in a controlled environment. The thermal analyses DTA/TGA, applied with a temperature gradient of 10o C/min., established crystallization ranges of 490,4 oC to 545,4 oC, for the elpasolite CS2NaHoBr6 and 501oC to 556oC, for the structure CS2NaErBr6.. The heat vacuum treatments were carried out at 505 oC and 526 oC respectively, obtaining optimum crystallization. The structural characterization was performed with powdered X-ray diffraction (XRD). The range between 12o and 80o (2θ), was analyzed for 3352 points, measured steps of 0.02o (2θ using the Rietveld profile refining program. The following crystallographic parameters were established: a0 = 11,279(1), and 11,293(4) Angstroms, for the two structures analyzed, respectively. The relationship Rexp wp in both cases is highly accurate for the 32 test lines that were analyzed. The structures present cubic closed packing Cs1+ 3 Cl1-, with Ho3+ and Er3+ atoms, filling the octahedral holes. The test data obtained will be very useful for completing the mass of experimental data needed to develop the design engineering, with specific applications for luminescent devices

  20. Isotopic exchange reactions. Kinetics and efficiency of the reactors using them in isotopic separation

    International Nuclear Information System (INIS)

    In the first part, some definitions and the thermodynamic and kinetic isotopic effect concepts are recalled. In the second part the kinetic laws are established, in homogeneous and heterogeneous medium (one component being on occasions present in both phases), without and with isotopic effects. Emphasis is put on application to separation of isotopes, the separation factor α being close to 1, one isotope being in large excess with respect to the other one. Isotopic transfer is then given by: J = Ka (x - y/α) where x and y are the (isotopic) mole fractions in both phases, Ka may be either the rate of exchange or a transfer coefficient which can be considered as the 'same in both ways' if α-1 is small compared to the relative error on the measure of Ka. The third part is devoted to isotopic exchange reactors. Relationships between their efficiency and kinetics are established in some simple cases: plug cocurrent flow reactors, perfectly mixed reactors, countercurrent reactors without axial mixing. We treat only cases where α and the up flow to down flow ratio is close to 1 so that Murphee efficiency approximately overall efficiency (discrete stage contactors). HTU (phase 1) approximately HTU (phase 2) approximately HETP (columns). In a fourth part, an expression of the isotopic separative power of reactors is proposed and discussed

  1. MTR fuel testing in BR2

    International Nuclear Information System (INIS)

    New fuel design for MTR 's requires to be qualified under representative conditions, that is geometry, neutron spectrum, heat flux and thermo hydraulic conditions. An irradiation device for fuel plates has been designed to derive the maximum benefit from the BR2 irradiation capacities. The fuel plates can be easily extracted from their support during a shutdown to undergo additional tests. One of these tests is the measurement of the thickness changes along the fuel plate. To that purpose, a facility in the reactor water pool has been designed to measure the fuel swelling with an accuracy of 5 μm using inductive probes. At SCK-CEN, the full range of destructive and non-destructive PIE can be performed, including γ-scanning, wet sipping, surface examination and other methods. (author)

  2. BR-100 spent fuel shipping cask development

    International Nuclear Information System (INIS)

    Continued public acceptance of commercial nuclear power is contingent to a large degree on the US Department of Energy (DOE) establishing an integrated waste management system for spent nuclear fuel. As part of the from-reactor transportation segment of this system, the B ampersand W Fuel Company (BWFC) is under contract to the DOE to develop a spent-fuel cask that is compatible with both rail and barge modes of transportation. Innovative design approaches were the keys to achieving a cask design that maximizes payload capacity and cask performance. The result is the BR-100, a 100-ton rail/barge cask with a capacity of 21 PWR or 52 BWR ten-year cooled, intact fuel assemblies. 3 figs

  3. Yrityksen brändin kehittäminen : Medbit Oy:n brändiuudistus

    OpenAIRE

    Salminen, Valtteri

    2016-01-01

    Opinnäytetyö tehtiin toimeksiantona ICT-alalla toimivalle Medbit Oy:lle. Yritys teki brändiuudistuksen vuoden 2015 alkupuolella ja halusi selvittää, miten asiakkaat, yhteistyökumppanit ja henkilökunta ovat ottaneet uudistuksen vastaan. Opinnäytetyössä perehdyttiin bränditutkimuksen lisäksi tutkimuksen kannalta olennaisiin aiheisiin brändin teoriasta. Brändiä käsittelevän tietoperustan avulla selvitettiin, mitä brändillä tarkoitetaan, millainen on hyvä brändi ja mitä hyötyjä siitä on yrityksel...

  4. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  5. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  6. Method for separating isotopes

    Science.gov (United States)

    Jepson, B.E.

    1975-10-21

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

  7. Developing isotopic functions

    International Nuclear Information System (INIS)

    Isotopic functions, or ratios of two isotopic variables, are used to verify Pu and U measurements of spent fuels in reprocessing plants. Systematic methods have been developed for forming and evaluating isotopic functions. This paper describes the method used at Battelle to form and evaluate isotopic functions. The data base at Battelle contains measurements and calculations for the fuel from 35 reactors

  8. The isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  9. The B(1/2 2P3/2) --> X(1/2 2Sigma + ) transition in XeBr

    Science.gov (United States)

    Clevenger, Jason O.; Tellinghuisen, Joel

    1995-12-01

    The B(1/2 2P3/2)→X(1/2 2Σ+) transition in XeBr is recorded at high resolution, using a CCD array detector to record spectra from Tesla discharge sources containing isotopically pure 136Xe with 81Br2 or 79Br2. The high signal/noise capabilities of the detector permit the measurement of discrete vibrational structure in this system, which has normally been treated as a purely bound-free transition. The assignments comprise 119 υ'-υ″ bands for 136Xe81Br and 86 for 136Xe79Br, spanning υ'=0-33 and υ″=0-16. The van der Waals ground state is analyzed through fits to the customary polynomials in (υ+1/2) and to near-dissociation expansions. Franck-Condon calculations are used to locate the X-state potential on the internuclear axis relative to the B state, which is modeled as a Rittner potential. The following fundamental spectroscopic constants (units cm-1, for 136Xe81Br) are obtained from the analysis: Te'=35 863.2, ωe'=135.72, ωexe'=0.32, ωe″=25.7, ωexe″=0.62. The ground state has a dissociation energy De″=254±2 cm-1 and supports 24 bound vibrational levels.

  10. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    This invention provides a method for separating uranium isotopes comprising the steps of selectively irradiating a photochemically-reactive uranyl source material at a wavelength selective to a desired isotope of uranium at an effective temperature for isotope spectral line splitting below about 77 K, further irradiating the source material within the fluorescent lifetime of the selectively irradiated source material to selectively photochemically reduce the selectively excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  11. Evaluation of production samples of the scintillators LaBr3:Ce and LaCl3:Ce

    International Nuclear Information System (INIS)

    We report on the evaluation of the performance of two recently developed scintillator materials, LaCl3:Ce and LaBr3:Ce, at the task of gamma ray spectroscopy. Their performance is compared to a standard scintillator used for gamma ray spectroscopy--a 25 mm diameter 25 mm tall cylinder of NaI:Tl. We measure the pulse height, energy resolution, and full-energy efficiency of production LaBr3:Ce and LaCl3:Ce scintillation crystals of different sizes and geometries for a variety of gamma-ray energies. Using production rather than specially selected crystals will establish whether immediate large-scale use is feasible. The crystal is excited by gamma rays from one of six isotopic sources (125I, 241Am, 57Co, 22Na, 137Cs, and 60Co) placed 15 cm away from the scintillator. Our measurements show that both LaCl3 and LaBr3 outperform NaI:Tl in almost all cases. They outperform NaI:Tl at all energies for the photopeak fraction and counting rate measurements, and for energy resolution at higher energies (above 200 keV for LaCl3 and 75 keV for LaBr3). The performance of production crystals is excellent and these scintillators should be considered for immediate use in systems where stopping power and energy resolution are crucial

  12. Dry storage of the BR3 spent fuel in the CASTOR BR3 cask

    International Nuclear Information System (INIS)

    The BR3 reactor was the first PWR plant installed in Europe. Started in 1962, BR3 was definitely shut down on June 30th, 1987. Used at the beginning of its life as a training device for commercial plant operators, it was also used during its whole life as test-reactor for new fuel types and assemblies. Most of the spent fuel was stored in the deactivation pool of the plant for more than 15 years. The reactor being now in decommissioning, it was decided to remove the spent fuel from the plant. After comparison of different solutions, the long term storage in dual purpose storage casks was selected in 1997. The selected CASTOR-BR3 cask is designed as a transport and storage cask for accommodating 30 spent fuel assemblies. As a type B(U) cask fitted with shock absorbers, it meets the transport requirements according to the IAEA guidelines and fulfils also the conditions for cask storage. (author)

  13. Computational study of elastic and electronically inelastic scattering of Br by ground state I atoms: Role of potential curve crossing

    International Nuclear Information System (INIS)

    Two-state, close-coupled quantal computations of the elastic and inelastic scattering of ground-state I atoms by ground-state Br and spin--orbit excited Br* atoms have been carried out over a range of total energies E from 0.01 to 0.94 eV. The possibility of translational--electronic energy transfer arises from the 3Pi0+ potential curve crossing at E=0.25 eV, responsible for the well-known IBr predissociation. The Y, B, and V12(R) diabatic potentials have been obtained by judicious extension (and manipulation) of the spectroscopically derived B and B' adiabats. At energies below the threshold for Br* formation (E/sub th/=0.457 eV) collisions of I+Br are necessarily elastic, exhibiting both shape and compound-state resonances. These produce interesting interference patterns in the differential cross sections, but no significant inverse-predissociation resonance (which might have been anticipated for E> or =0.25 eV). The main features of the elastic scattering can be fairly well approximated considering only the lower adiabat, even at post threshold energies where the inelastic process becomes important. An oscillatory pattern found in the total elastic cross section has been identified with a barrier effect associated with the maximum in this B adiabat. Total inelastic cross sections are well reproduced by the closed-form Landau--Zener--Stueckelberg (LZS) approximation. The Boltzmann-averaged LZS rate constant for the collisional deactivation I+Br*→I+Br is calculated to be 1.8x10-11 cm3 sec-1 at 300 K (with only a slight temperature dependence over the range 300--1000 K). This large rate is due to the inverse predissociation mechanism, common

  14. ESR spectrum and structure of BrF6

    International Nuclear Information System (INIS)

    The BrF6 radical has been obtained by γ irradiation of a mixture of BrF5 in SF6. The ESR spectrum was obtained and used to confirm the identity of the radical and to obtain hyperfine coupling constants. (AIP)

  15. Corrosion inhibition performance of a ionic liquid surfactant Br

    Directory of Open Access Journals (Sweden)

    Jing LIU

    2016-02-01

    Full Text Available In order to study the novel green organic mercury-substituting inhibitors, the ionic liquid surfactant 1-methyl-3-dodecyl imidazole bromide ( Br is synthesized with N-methyl imidazole and 1-bromodecane as raw materials. The corrosion inhibition of Br for zinc in zinc-manganese batteries is investigated using electrochemical methods and weight loss methods. The results show that corrosion inhibition efficiency increases with the increase of the concentration of Br, and when the concentration is higher than 8×10-3 mol/L, the inhibition efficiency tends to be stable. The polarization curve shows that Br belongs to mixed-type corrosion inhibitor. The thermodynamic parameters show that Br is spontaneously adsorbed on the zinc surface, forming a monomolecular adsorption layer, which fits with Langmuir adsorption isotherm with physical and chemical adsorption mechanism.

  16. Bromine recovery in residual solutions generated in the 15 N isotopic determination methodology (Rittenberg, 1946)

    International Nuclear Information System (INIS)

    The isotopic determination of 15 N (Rittenberg, 1946) is a methodology used in the Laboratory of Isotope Stable (CENA/USP). In this procedure, in the oxidation of nitrogen species for N2, solution of Li Br O is used, generating as residue 50 L y-1 of solution contends Li Br and Li Br O. Seeking to recover the bromine contained in that residue, very toxic substance, a special line was built composed by reaction balloons (1 and 2 liters), addition funnel, gas flow regulator and connections in glass. In the system proposed, after the acidification (sulfuric acid) of the alkaline residual solution, the liberated bromine (Br2) it was then dragged by flow of nitrogen and reacted with solution of LiOH. That reaction facilitated the production of Li Br O in solution (Efficiency = 82±2%), that was reused later on same analytic procedure. The high cost of the liquid bromine is another attractiveness that corroborates the employment of the developed procedure. They took place isotopic determinations using the recovered solutions and prepared, and the observed values didn't show statistical difference (T test of Student). The presented procedure is part of the Management Program of Chemical Residues of CENA/USP, which seeks to destine the residues of responsibility of the institution appropriately, forming professionals to the practices of environmental management. (author)

  17. Hydrogen isotopic composition of bacterial tetraether membrane lipids as recorder of precipitation dynamics

    Science.gov (United States)

    Peterse, F.; Ernst, N.; Eglinton, T. I.

    2012-12-01

    Recent research has shown that the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGTs), membrane lipids of soil bacteria ubiquitously present in soils worldwide, reflects the climatic conditions of the source organism's living environment. Hence, their distribution in sedimentary archives can be, and has been used to reconstruct past changes in continental air temperature. Over the past decade, compound-specific hydrogen isotope analysis (δD) of lipid biomarkers has been implemented as a method to track changes in the hydrological cycle. Since the hydrogen isotopic composition of a biomarker is related to the moisture source of its precursor organism, the δD-value of brGDGTs may reflect the hydroclimate experienced by soil microorganisms. In this study, we determine the distribution and hydrogen isotopic composition of brGDGTs in soils along an altitudinal gradient from the Cherrapunji plateau in Northeast India, known as 'the wettest place on earth', to test if brGDGTs, besides temperature, also record the precipitation signal of their living environment, and thus their suitability as proxy for past precipitation dynamics. Based on the 'amount' and 'altitude effects' on the precipitation δD in this monsoon area, the brGDGTs are expected to be δD-depleted on top of the plateau relative to in the valley. However, to render the brGDGTs amendable for gas chromatographic separation and determination of their isotopic composition, their ether bonds are generally cleaved with HI, during which the possibility of hydrogen exchange occurs, influencing the δD-value of the brGDGT-derived hydrocarbons. The Cherrapunji transect provides an excellent setting to test the occurrence and potential consequences of hydrogen exchange. The distribution of brGDGTs along the 1800m long altitude transect reflects the adiabatic cooling of air with altitude, indicating active membrane adaptation to environmental changes. Furthermore, comparison of brGDGT-δD with

  18. 大白菜BrTCP24基因的克隆与功能分析%Cloning and Functional Analysis of BrTCP24 Gene in Chinese Cabbage (Brassica rapa L.ssp.pekinensis)

    Institute of Scientific and Technical Information of China (English)

    王凤德; 谭婷婷; 张一卉; 李景娟; 李化银; 李利斌; 刘立锋; 高建伟

    2013-01-01

    It is very important to isolate and characterize the genes responsible for negative control of the leaf heading growth of Chinese cabbage,which can be help to speed up breeding progress of the small heading Chinese cabbage varieties that meet the current market demands.Here,a full-length TCP cDNA named BrTCP24,which belongs to the second subgroups of TCP domain family,was isolated from leaves of Chinese cabbage inbred line Fushanbaotou (Brassica rapa L.ssp.pekinensis).The full-length cDNA of BrTCP24 consisted of 1 221 nucleotides,and was predicted to code a 406-amino acid polypeptide.In addition,there were no introns in BrTCP24 gene.The phylogenetic analysis about BrTCP24 and TCP families in Arabidopsis was carried out using the software of MEGA4.0.The result indicated that BrTCP24 gene and Arabidopsis AtTCP3 gene would belong to the same branch,which suggested they had closely genetic relationship.The alignment of predicted amino acid sequences of BrTCP24 and Arabidopsis AtTCP3 indicated that there was 55.15% identity between them.Additionally,these two proteins contained conserved TCP domain and had 91.53% identity in this domain.These results suggested that BrTCP24 and Arabidopsis AtTCP3 would have similar biological functions.The semiquantitive RT-PCR indicated that BrTCP24 gene was expressed in roots,dwarf stems,rosette leaves,folding leaves,flowers,siliques and bud flowers examined in Chinese cabbage.Among them,rosette leaves had the highest mRNA level,followed by roots,folding leaves,flowers,siliques and bud flowers,while dwarf stems had the lowest mRNA level.Interestingly,the expression level of BrTCP24 didn't effect by 5 μmol NAA treatment in 12 h period.To test the function of BrTCP24,we then engineered Arabidopsis plants that would over-express BrTCP24 ectopically,driven by CaMV 35S promoter,and obtained 17 transgenic lines by Kanamycin and PCR screening.Using RT-PCR method,we randomly detected 5 transgenic lines and found all of them could express

  19. Giant oxygen isotope effect in manganese perovskites

    International Nuclear Information System (INIS)

    The giant oxygen isotope shift of the temperature of the ferromagnetic phase transition is calculated in La0.8Ca0.2MnO3 taking into account the values of the bandwidth, the Jahn-Teller polaron energy and the value of the stretching Mn-O optical phonon frequency. The obtained result is close to the experimental one

  20. Standardization of gamma sources using NaI (Tl) and LaBr3 (Ce) detectors: measurements and simulations

    International Nuclear Information System (INIS)

    In the present work, we made detailed studies on activity of a single gamma emitter 137Cs for different values of source-detector separation. The studies were made using NaI (Tl) and LaBr3 (Ce) detectors. Monte Carlo techniques were employed to estimate the intrinsic photo-peak efficiencies corresponding to 662 keV gamma rays. We have also made activity measurements on a double gamma emitter 60Co using sum-peak method. In both cases, calibrated sources were used and the measured results were compared with the activities certified by the manufacturer (Board of Radiation and Isotope Technology, Govt. of India)

  1. Isotopic geology; Geologie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Allegre, C. [Paris-7 Univ. Denis Diderot, 75 (France); Institut de physique du globe de Paris, 75 - Paris (France)

    2005-07-01

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  2. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144Sm and 154Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  3. Mg Isotopes of the Late Permian Evaporites, New Mexico, USA

    Science.gov (United States)

    Feng, C.; Gao, C. H.; Chang, S. C.

    2015-12-01

    Mg isotope holds promise to decipher the evaporative environment of evaporites. High-precision Mg isotope compositions of the late Permian langbeinites have been measured by using MC-ICPMS. The equilibrium Mg isotope fractionation factor between langbeinite and aqueous Mg2+ solutions has been determined using quantum chemistry calculations. All computations are employed at B3LYP/6-311++G(2d,2p) level and solvation effects are treated by solvent model ("water-droplet" approach), mineral structures are constructed using volume variable cluster models (VVCM). The Mg isotope compositions of the langbeinite samples, whose total formation thickness ranges up to 100 meters, are extremely isotopically lighter than that of modern seawater and relatively homogeneous (δ26MgDSM3 is from -4.12±0.03‰ to -3.81±0.07‰ v.s. -0.83‰ of modern seawater). The computed equilibrium Mg isotope fractionation factors between langbeinite and aqueous Mg2+ solutions are -2.73‰, -2.66‰ and -2.53‰ at 25, 30 and 40 ℃, respectively. These significant equilibrium fractionation factors indicate that a huge equilibrium Mg isotope fractionation between langbeinite and its parent brine can happen during langbeinite depositions, and langbeinites are enriched in isotopically light 24Mg comparing to the brine. Using the computed fractionation factors to simulate a Rayleigh fractionation process of langbeinite Mg precipitation, we find that a significant Mg isotope difference between langbeinite and its growing brine (seawater) is indeed present but the Mg isotope composition of langbeinite merely increase monotonically in a closed system. Because of that, the homogenous Mg isotope compositions of such a thick evaporite sequence suggest a disequlibrium effect rather than an equilibrium Mg isotope fractionation behavior during its formation. Combined with its prevailing Mg-bearing character, the homogenous Mg isotope compositions reveal that this the late Permian langbeinite sequence has

  4. The BR-3 decommissioning project, Belgium

    International Nuclear Information System (INIS)

    BR-3 was a small 10 MW(e) PWR which was shut down in 1987 after 25 years of operation. It was selected as an EU pilot project for the research and development programme on decommissioning of nuclear installations. The decommissioning project started in 1989. The optimization of the management of waste material generated by decommissioning activities has always been an intensive task and the minimization of the radioactive waste a priority. Over the past 16 years, the factors influencing the management of waste have been constantly evolving in Belgium, steered mainly by the following changes in technologies, regulations and economic conditions: - The publication of the Royal Decree of 20 July 2001, establishing a legal frame on decommissioning and including a set of clearance levels; - The improvement of the instrumentation used for characterization; - The increase in the performance of decontamination techniques; - The cost increase of the waste disposal paths; - The implementation of international recommendations in areas such as environmental impact, waste categorization, human aspects, ethics, etc.; -The strengthening of the legislation related to industrial safety and environmental release; - The diminution of the background radiation level at the decommissioning site itself. The first part of this annex gives a description of relevant influencing factors in order to define the context in which the dismantling activities took place. The second part puts in perspective the strategy chosen for the management of the waste, recognizing the influencing factors. As mentioned in the scope of this report, the focus is LLW. High and intermediate level wastes for which disposal in dedicated repositories is assumed are outside the scope of this report. They are therefore not examined in detail here

  5. Enhanced tropospheric BrO concentrations over the Antarctic sea ice belt in mid winter observed from MAX-DOAS observations on board the research vessel Polarstern

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2007-02-01

    Full Text Available We present Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS observations of tropospheric BrO carried out on board the German research vessel Polarstern during the Antarctic winter 2006. Polarstern entered the area of first year sea ice around Antarctica on 24 June 2006 and stayed within this area until 15 August 2006. For the period when the ship cruised inside the first year sea ice belt, enhanced BrO concentrations were almost continuously observed. One interesting exception appeared on 7 July 2006, when the sun elevation angle was < about –2.8° indicating that for low insulation the photolysis of Br2 and/or HOBr is too slow to provide sufficient amounts of Br radicals. Before and after the period inside the first year sea ice belt, typically low BrO concentrations were observed. Our observations indicate that enhanced BrO concentrations around Antarctica exist about one month earlier than observed by satellite instruments. The small BrO concentrations over the open oceans indicate a short atmospheric lifetime of activated bromine without contact to areas of first year sea ice. From detailed radiative transfer simulations we find that MAX-DOAS observations are about one order of magnitude more sensitive to near-surface BrO than satellite observations. In contrast to satellite observations the MAX-DOAS sensitivity hardly decreases for large solar zenith angles and is almost independent from the ground albedo. Thus this technique is very well suited for observations in polar regions close to the solar terminator. Furthermore, combination of both techniques could yield additional information on the vertical distribution of BrO in the lower troposphere.

  6. Selected Femme / Homme - brändin lanseeraus Suomen markkinoille

    OpenAIRE

    Saarinen, Saila

    2009-01-01

    Tanskalaisomistuksessa oleva, kansainvälinen muotitalo Bestseller A/S lanseerasi uuden Selec-ted Femme / Homme - brändin Suomen markkinoille lokakuussa 2008. Tuotemerkin vali-koimiin kuuluu naisten ja miesten vaatteet, asusteet sekä jalkineet. Mallistoista on tuotteita arkeen ja juhlaan. Niissä yhdistyvät hyvän hinta laatu-suhteen lisäksi trendikkyys. Opinnäytetyössä tarkasteltiin brändin ensimmäisen unisex -myymälän lanseerausta kuluttajil-le. Työn tarkoitus oli tutkia uuden brändin ide...

  7. Bränditutkimus Etelä-Pohjanmaan Osuuspankille

    OpenAIRE

    Jämbäck, Anna-Leena

    2013-01-01

    Opinnäytetyön tarkoituksena oli tutkia Etelä-Pohjanmaan Osuuspankin brändiä sen 20–30-vuotiaiden asiakkaiden näkökulmasta. Ensimmäisenä tavoitteena oli perehtyä brändeihin. Opinnäytetyön toisena tavoitteena oli bränditutkimuksen toteuttaminen EPOP:n 20–30-vuotiaille asiakkaille, jotta saataisiin selville millaiseksi se koetaan eri osa-alueilla sekä kokonaisuutena nuorten aikuisten keskuudessa. Kolmantena tavoitteena oli pohtia tutkimustulosten perusteella uusia ideoita organisaation markkinoi...

  8. Brøndby på Facebook

    OpenAIRE

    Johansen, Louise Løvendahl; Petersen, Simon Boje

    2012-01-01

    Dette er en målgruppeanalyse af Brøndby IF's kommunikation på Facebook, som tager udgangspunkt i Brøndbyfans. Specialet bygger på teori om fællesskab og netværk, hvor teoretikerne Castells, Baumann, Luhmann, Jesper Tække m.fl. er brugt, som alle arbejder med Facebook som enten et netværks- eller fællesskabsmedie. Specialet analysere, hvorledes Brøndby IF formår at kommunikere hensigstsmæssigt til deres fans, og om Facebook kan bruges til genopbyggelse af supporterfællesskabet.

  9. Kolea AK/JPK : -brändin konseptisuunnittelu

    OpenAIRE

    Koskilahti, Anni

    2016-01-01

    Opinnäytetyössä suunniteltiin valmis konsepti, perusteilla olevalle, Kolea – nimiselle vaatetusalan yritykselle ja brändille. Työssä käytettiin design managementin ja brändäyksen teorioita. Työn tavoitteena oli selventää design managementin mukainen kokonaisuus ja kehittää eheä konsepti vaatetusalan brändille. Työn toimintasuunnitelmaan ja sen kulkuun sovellettiin toimintatutkimuksen syklimallia. Opinnäytetyössä päätiedonhankintamenetelminä käytettiin havainnointia, haastatteluja ja benchm...

  10. Measurement and simulation of proton induced activation of LaBr3:Ce

    International Nuclear Information System (INIS)

    To assess the suitability of LaBr3:Ce scintillators for space mission applications, proton induced activation of LaBr3 has been investigated. The crystals were irradiated using proton beams at several different energies to mimic the spectrum of a solar flare. We have measured the activation both internally and externally by measuring the count rate in the scintillator itself and with a germanium detector. The setup allowed to identify the dominant radioactive isotopes before and after irradiation. At lower energies, we have seen that the dominant source of activation originates from proton induced activation of bromine. At energies above 2MeV the activation is several orders of magnitude less and the spectrum shows no distinct features. In addition, we discuss results of a simulation of the activation using Monte Carlo methods in combination with state-of-the-art calculations of nuclear cross-sections. Results from the Monte Carlo simulations and the measurements agree within a factor of 2

  11. Characterization of groundwater in the Ejina Basin,northwest China:hydrochemical and environmental isotopes approaches

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    To characterize the groundwater in the Ejina Basin,surface and groundwater samples were collected in May and October of 2002.On-site analyses included temperature,electrical conductance(EC),total alkalinity(as HCO 3) by titration,and pH.Chemical analyses were undertaken at the Geochemistry Laboratory of the Cold and Arid Region Environmental and Engineering Institute,Chinese Academy of Sciences,Lanzhou,China.The pH of the groundwater ranged from 7.18 to 8.90 with an average value of 7.72,indicating an alkaline nature.The total dissolved solids(TDS) of the groundwater ranged from 567.5 to 5,954.4 mg/L with an average of 1,543.1 mg/L and a standard deviation of 1,471.8 mg/L.According to the groundwater salinity classification of Robinove et al.(1958),47.4 percent of the samples were brackish and the remainder were fresh water.The ion concentration of the groundwater along the riverbed and near the southern margin of the basin were lower than those farther away from the riverbed.The groundwater in the study area was of Na +-HCO 3 type near the bank of the Heihe River and in the southern margin of the basin,while Na +-SO 4 2-Cl type samples were observed in the terminal lake region.In the desert area the groundwater reached a TDS of 3,000-6,000 mg/L and was predominantly by a Na +-Cl chemistry.Br/Cl for the water of Ejina Basin indicates an evaporite origin for the groundwater with a strongly depleted Br/Cl ratio(average 0.000484).The surface water was slightly enriched in Br/Cl(average 0.000711) compared with groundwater.The calculated saturation index(SI) for calcite and dolomite of the groundwater samples range from 0.89 to 1.31 and 1.67 to 2.67 with averaged 0.24 and 0.61,respectively.About 97 percent of the groundwater samples were kinetically oversaturated with respect to calcite and dolomite,and all the samples were below the equilibrium state with gypsum.Using isotope and hydrochemical analyses,this study investigated the groundwater evolution and its residence

  12. Equilibrium reconstruction in the TCA/Br tokamak; Reconstrucao do equilibrio no tokamak TCA/BR

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Wanderley Pires de

    1996-12-31

    The accurate and rapid determination of the Magnetohydrodynamic (MHD) equilibrium configuration in tokamaks is a subject for the magnetic confinement of the plasma. With the knowledge of characteristic plasma MHD equilibrium parameters it is possible to control the plasma position during its formation using feed-back techniques. It is also necessary an on-line analysis between successive discharges to program external parameters for the subsequent discharges. In this work it is investigated the MHD equilibrium configuration reconstruction of the TCA/BR tokamak from external magnetic measurements, using a method that is able to fast determine the main parameters of discharge. The thesis has two parts. Firstly it is presented the development of an equilibrium code that solves de Grad-Shafranov equation for the TCA/BR tokamak geometry. Secondly it is presented the MHD equilibrium reconstruction process from external magnetic field and flux measurements using the Function Parametrization FP method. this method. This method is based on the statistical analysis of a database of simulated equilibrium configurations, with the goal of obtaining a simple relationship between the parameters that characterize the equilibrium and the measurements. The results from FP are compared with conventional methods. (author) 68 refs., 31 figs., 16 tabs.

  13. LiikeAkatemian brändimielikuvan tutkiminen ja brändin kehittäminen

    OpenAIRE

    Petäsnoro, Iida-Mari; Rajala, Emilia

    2014-01-01

    Toteutamme opinnäytetyömme Lapin ammattikorkeakoulussa Tornion kampuksella toimivalle LiikeAkatemialle, jossa opiskellaan käytännönläheisesti tiimiyrityksissä. Tavoitteenamme on tutkia LiikeAkatemian aikaisempaa brändimarkkinointia, ja sen vaikutusta nykyisen brändimielikuvan tilaan liiketalouden opettajien ja opiskelijoiden keskuudessa. Näiden tutkimustulosten perusteella esitämme brändin kehittämiseen liittyviä kehitysideoita. Työn teoreettinen viitekehys on koottu aiheeseen liittyvästä...

  14. Brüssel - unistus Euroopa pealinnast / Kristi Grishakov

    Index Scriptorium Estoniae

    Grishakov, Kristi

    2008-01-01

    Brüsseli linnaplaneerimise ajaloost, linnaehituslikest ja sotsiaalset laadi probleemidest, võimalikust tulevikust Euroopa pealinnana. Berlage Instituudi näitusest "A Vision for Brussels" Bozari kunstikeskuses

  15. GMO konverents Brüsselis / Nastja Pertsjonok

    Index Scriptorium Estoniae

    Pertsjonok, Nastja

    2007-01-01

    Brüsselis toimunud GMO-vabade piirkondade konverentsist, kus räägiti GMO-vabade piirkondade liikumisest, GMO-de lubamisest ja keelamisest ning hoiakutest nende suhtes Euroopa Liidus ja mujal maailmas

  16. Performance evaluation of LaBr3: Ce scintillator

    International Nuclear Information System (INIS)

    The cerium doped lanthanum bromide crystal (LaBr3: Ce) is a new kind of scintillator with many advantages such as good energy resolution, high light output, short decay time, good proportionality response. These properties make the LaBr3: Ce attractive substantial interest to use in the radiation detection. The energy resolution were investigated with Φ25 × 25 mm LaBr3: Ce coupled to a Hamamatsu R8900 photomultiplier tube. Energy resolution of 3.6% (FWHM) have been achieved for 511 keV photons (18F source) at room temperature. Decay time constant of 20 ns have been acquired with a Hamamatsu fast-time-response R9800 photomultiplier tube. The results approve the excellent characterizations of LaBr3: Ce and imply its enormous potentiality in the radiation detectors of gamma-ray spectroscopy and PET. (authors)

  17. Traian Brăileanu în documente (I

    Directory of Open Access Journals (Sweden)

    Radu-Florian Bruja

    2006-11-01

    Full Text Available A Romanian’s politician from Bukovina, Traian Brăileanu agreed the idea of possible activities of former political parties. Although he was a regional party, his activity was oriented to complete the unification and consolidation of Romania. Traian Brăileanu was a sociologist and doctor Professor at University of Cernăuţi. A polyglot, TraianBrăileanu has known the Greek and German’s philosophy. He has begun his political activity in People’s Party, then in League of National and Christian Protection and finally in The Legionary Movement. We bring bock into scientific circuit some documents from the personal records of Traian Brăileanu. This documents covering the period 1920-1921 on the ground of some investigations archirved by the author from Cernăuţi, Ukraina.

  18. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  19. BR2: Some aspects of structural mechanics

    International Nuclear Information System (INIS)

    This article discusses some of the important aspects of structural mechanics of BR2, namely: the follow-up of the beryllium matrix and of the reactor vessel and the seismic qualification. According the licence, a follow up program for the beryllium matrix is mandatory. This inspection is necessary because of the swelling of beryllium during irradiation. Due to this swelling, the individual beryllium blocks make contact between each other. This results in mechanical stresses and, because beryllium is a brittle material, cracks. At regular intervals inspection are made to evaluate the evolution of the swelling and the cracks. The maximum allowed neutron fluence is 6.4 1022 fast neutrons (energy more than 1 MeV) per cm2 . After this time the matrix has to be replaced. This has been done already twice. During the replacement an inspection of the reactor pressure vessel must be made. Last inspection was performed in 1996, using ultrasonic and eddy current inspections. On this occasion a fracture mechanics calculation was made and the minimum allowed fracture toughness of material was determined. Since very little information on irradiated aluminium 5052-O is available, a number of samples were cut out of a second wall around the vessel. This aluminium had received nearly the fluence. Out of the samples test pieces (tensile and charpy) were made. A number of them were tested immediately, while the other was loaded in the reactor for accelerated irradiation. In this way a material follow up program was started. This program still continues. During the period safety reassessment the authorities requested a seismic qualification. It was decided to make a full dynamic calculation, with input a 0.1g zero period peak ground acceleration and a regulatory guide 1.60 spectrum. The installation can withstand this earthquake, considered as a safe shutdown earthquake. A few structural reinforcements were necessary. The main ones were the primary piping outside the containment

  20. Kan lignin omdannes til flydende brændstof?

    DEFF Research Database (Denmark)

    Nielsen, Joachim Bachmann; Jensen, Anders; Felby, Claus;

    2015-01-01

    Ved en solvolytisk omdannelse af plantematerialet lignin til et flydende brændstof behandles det ved høj temperatur og højt tryk i et passende opløsningsmiddel. En sådan proces kan gennemføres ikke-katalytisk og være med til at skabe flydende brændsler baseret på vedvarende energikilder. Her...

  1. Accurate determination and certification of bromine in plastic by isotope dilution inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ohata, Masaki, E-mail: m-oohata@aist.go.jp; Miura, Tsutomu

    2014-07-21

    Highlights: • Accurate analytical method of Br in plastic was studied by isotope dilution ICPMS. • A microwave acid digestion using quartz vessel was suitable for Br analysis. • Sample dilution by NH{sub 3} solution could remove memory effect for ICPMS measurement. • The analytical result of the ID-ICPMS showed consistency with that of INAA. • The ID-ICPMS developed could apply to certification of Br in candidate plastic CRM. - Abstract: The accurate analytical method of bromine (Br) in plastic was developed by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The figures of merit of microwave acid digestion procedures using polytetrafluoroethylene (PTFE) or quartz vessels were studied and the latter one was suitable for Br analysis since its material was free from Br contamination. The sample dilution procedures using Milli-Q water or ammonium (NH{sub 3}) solution were also studied to remove memory effect for ICPMS measurement. Although severe memory effect was observed on Milli-Q water dilution, NH{sub 3} solution could remove it successfully. The accuracy of the ID-ICPMS was validated by a certified reference material (CRM) as well as the comparison with the analytical result obtained by an instrumental neutron activation analysis (INAA) as different analytical method. From these results, the ID-ICPMS developed in the present study could be evaluated as accurate analytical method of Br in plastic materials and it could apply to certification of Br in candidate plastic CRM with respect to such regulations related to RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive.

  2. Accurate determination and certification of bromine in plastic by isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: • Accurate analytical method of Br in plastic was studied by isotope dilution ICPMS. • A microwave acid digestion using quartz vessel was suitable for Br analysis. • Sample dilution by NH3 solution could remove memory effect for ICPMS measurement. • The analytical result of the ID-ICPMS showed consistency with that of INAA. • The ID-ICPMS developed could apply to certification of Br in candidate plastic CRM. - Abstract: The accurate analytical method of bromine (Br) in plastic was developed by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The figures of merit of microwave acid digestion procedures using polytetrafluoroethylene (PTFE) or quartz vessels were studied and the latter one was suitable for Br analysis since its material was free from Br contamination. The sample dilution procedures using Milli-Q water or ammonium (NH3) solution were also studied to remove memory effect for ICPMS measurement. Although severe memory effect was observed on Milli-Q water dilution, NH3 solution could remove it successfully. The accuracy of the ID-ICPMS was validated by a certified reference material (CRM) as well as the comparison with the analytical result obtained by an instrumental neutron activation analysis (INAA) as different analytical method. From these results, the ID-ICPMS developed in the present study could be evaluated as accurate analytical method of Br in plastic materials and it could apply to certification of Br in candidate plastic CRM with respect to such regulations related to RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive

  3. Close-ups

    DEFF Research Database (Denmark)

    Fausing, Bent

    2013-01-01

    Investigations in the close-up and its meaning regarding nearness, abstraction and transparency. Face, facelike and animism are also major key-words in thsi article... . I have always been fascinated with the close-up, not as an end, but a filter of opportunities to open up for and nearness of...... transcendence, associations and memories. The close-up is not the end, it rather in my view to be regarded as a beginning of different perceptions...

  4. Stable isotope applications

    International Nuclear Information System (INIS)

    The following domains of stable isotope applications are presented: - isotope dilution analyses as in trace analyses or volume and mass determinations; - stable isotopes as tracers as applied in environmental studies, agricultural research, products and objects authentification, transport phenomena, reaction mechanisms, determinations of structure and complex biological function, metabolism studies, diagnostic respiration tests, positron emission tomography; - equilibrium isotopic effects as investigated in measurements of effects, studies of equilibrium conditions, the mechanism of drug action, study of natural processes, water circuit, temperature measurements; - kinetic isotopic effects, as, for instance, reaction rates and mechanisms, solvent isotopic effects; - stable isotopes for advanced nuclear reactors as, for instance, uranium nitride with 15 N as nuclear fuel or 157 Gd for reactivity control. In spite of the difficulties regarding stable isotope use and first of all, of the difficult and costly analytical techniques, a continuous growth of the number of stable isotope applications in different fields is registered. The number of works and scientific meetings on the subject, as organized by the International Society of Isotopes and IAEA-Vienna, Gordon Conferences, regional meetings in Germany, France, etc. increase continuously. Development of the stable isotope application on a larger scale requires improving both their production technologies as well as those of labelled substances and, at the same time, the analytical methods

  5. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    Chromium (Cr) stable isotopes are a useful tracer of changes in redox conditions because changes in its oxidation state are accompanied by an isotopic fractionation. For this reason the Cr isotope system is being developed as a potential tool for paleo-redox reconstruction. Dissolved Cr in seawater...... is incorporated into carbonates. Hence, ancient carbonates can potentially record the Cr isotopic composition (δ53Cr ‰) of seawater in the geological past. Reliable application and interpretation of this proxy requires a detailed knowledge about processes that fractionate Cr on the Earth’s surface......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river...

  6. Application of TlBr to nuclear medicine imaging

    Science.gov (United States)

    Cirignano, Leonard; Kim, Hadong; Kargar, Alireza; Churilov, Alexei V.; Ciampi, Guido; Higgins, William; Kim, Suyoung; Barber, Bradford; Haston, Kyle; Shah, Kanai

    2012-10-01

    Thallium bromide (TlBr) has been under development for room temperature gamma ray spectroscopy due to high density, high Z and wide bandgap of the material. Furthermore, its low melting point (460 °C), cubic crystal structure and congruent melting with no solid-solid phase transitions between the melting point and room temperature, TlBr can be grown by relatively simple melt based methods. As a result of improvements in material processing and detector fabrication over the last several years, TlBr with electron mobility-lifetime products (μeτe) in the mid 10-3 cm2/V range has been obtained. In this paper we are going to report on our unipolar charging TlBr results for the application as a small animal imaging. For SPECT application, about 5 mm thick pixellated detectors were fabricated and tested. About 1 % FWHM at 662 keV energy resolution was estimated at room temperature. By applying the depth correction technique, less than 1 % energy resolution was estimated. We are going to report the results from orthogonal strip TlBr detector for PET application. In this paper we also present our latest detector highlights and recent progress made in long term stability of TlBr detectors at or near room temperature. This work is being supported by the Domestic Nuclear Detection Office (DNDO) and the Department of Energy (DOE).

  7. Elementary excitations in isotope-mixed crystals

    International Nuclear Information System (INIS)

    Over the last five decades, the isotope effect has been one of the major research in solids. Most of the physical properties of a solid depend to a greater or lesser degree on its isotopic composition. Scientific interest, technological promise and increased availability of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor and insulator crystals. A great number of stable isotopes and well-developed methods of their separation has made it possible to date to grow crystals of C, LiH, ZnO, ZnSe, CuCl, GaN, GaAs, CdS, Cu2O, Si, Ge and α-Sn with a controllable isotopic composition. The use of such objects allows the investigation of not only the isotope effects in lattice dynamics (vibrational, elastic and thermal properties) but also the influence of such effects on the electronic states via electron-phonon coupling (the renormalization of the band-to-band transition energy Eg, the exciton binding energy EB and the size of the longitudinal-transverse splitting ΔLT). The thermal conductivity enhancement in the isotopically enriched materials amounts (C; Ge; Si) to almost 10% at room temperature and is close to a factor of six at the thermal conductivity maximum around 20K (Si-case). The change in the lattice constant is Δa/a∼10-3-10-4, while the change δcik in the elastic constants amounts to several percent. The nonlinear dependence of the free exciton luminescence (especially Cx1312C1-x, LiHxD1-x) intensity on the excitation density allows to consider these crystals as potential solid-state lasers in the UV part of the spectrum. Isotopic information storage may consist in assigning the information 'zero' or 'one' to mono-isotopic microislands (or even to single atoms) within a bulk crystalline (or thin film) structure. Isotope information storage and isotope quantum computers are briefly discussed

  8. Wannier-Mott excitons in isotope-disordered crystals

    International Nuclear Information System (INIS)

    Most of the physical properties of a solid depend to a greater or lesser degree on its isotopic composition. Scientific interest, technological promise and increased availability of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor and insulator crystals. A systematic analysis is for the first time presented of isotopic and disorder effects observed in crystals of various isotopic composition via low-temperature large-radius exciton spectroscopy. Substituting a light isotope with a heavy one increases the interband transition energy and the binding energy of the Wannier-Mott exciton as well as the magnitude of the longitudinal-transverse splitting. The nonlinear variation of these quantities with the isotope concentration is due to the isotopic disordering of the crystal lattice and is consistent with the concentration dependence of line half-widths in exciton reflection and luminescence spectra. The common nature of the isotopic and disorder effects in the crystals of C, LiH, ZnO, ZnSe, CuCl, CdS, Cu2O, GaAs, Si and Ge is emphasized. The review closes with an outlook on the exciting future possibilities offered through isotope control of a wide range of semiconductor and insulator crystals. (author)

  9. Wavelength calculation of highly stripped ions S10+→S13+, Br23+, Br24+, Ge20+, Ge21+

    International Nuclear Information System (INIS)

    Wavelengths of highly stripped ions S10+ →S13+ , Br23+ , Br24+ , Ge20+ , Ge21+ are calculated by means of GRASP code. The calculations are performed based on multiconfiguration Dirac-Fock technique. Corrections to the energy levels due to the retarded Coulomb interaction (Breit interaction) and the polarization of the vacuum by the nuclear distribution and electron self-energy are included in a perturbation approximation. Comparisons with the new experimental data by CIAE group are presented

  10. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, M.; H. Bösch; Butz, A.; Camy-Peyret, C.; Chipperfield, M. P.; Engel, A.; Goutail, F.; Grunow, K.; Hendrick, F.; Hrechanyy, S.; B. Naujokat; J.-P. Pommereau; Van Roozendael, M.; C. Sioris; F. Stroh

    2006-01-01

    For the first time, results of four stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-borne in situ ...

  11. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, M.; H. Bösch; Butz, A.; Camy-Peyret, C.; Chipperfield, M. P.; Engel, A.; Goutail, F.; Grunow, K.; Hendrick, F.; Hrechanyy, S.; B. Naujokat; J.-P. Pommereau; Van Roozendael, M.; C. Sioris; F. Stroh

    2005-01-01

    For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-b...

  12. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, M.; H. Bösch; Butz, A.; Camy-Peyret, C.; Chipperfield, M. P.; Engel, A.; Goutail, F.; Grunow, K.; Hendrick, F.; Hrechanyy, S.; B. Naujokat; Pommereau, J.-P.; Van Roozendael, M.; C. Sioris; F. Stroh

    2005-01-01

    International audience For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observat...

  13. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, M.; H. Bösch; Butz, A.; Camy-Peyret, C.; Chipperfield, M. P.; Engel, A.; Goutail, F.; Grunow, K.; Hendrick, F.; Hrechanyy, S.; B. Naujokat; Pommereau, J.-P.; Van Roozendael, M.; C. Sioris; F. Stroh

    2006-01-01

    International audience For the first time, results of four stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include ...

  14. Balloon-borne stratospheric BrO measurements : comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, Marcel; Bösch, Hartmut; BUTZ Andre; Camy-Peyret, Claude C.; Chipperfield, Martyn P.; Engel, Andreas; Goutail, Florence; Grunow, Katja; Hendrick, François; Hrechanyy, Serhiy; Naujokat, Barbara; Pommereau, Jean-Pierre; Van Roozendael, Michel; Sioris, Christopher E.; Stroh, Fred

    2005-01-01

    For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-b...

  15. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, Marcel; Bösch, Hartmut; BUTZ Andre; Camy-Peyret, Claude C.; Chipperfield, Martyn P.; Engel, Andreas; Goutail, Florence; Grunow, Katja; Hendrick, François; Hrechanyy, Serhiy; Naujokat, Barbara; Pommereau, Jean-Pierre; Van Roozendael, Michel; Sioris, Christopher E.; Stroh, Fred

    2006-01-01

    For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-b...

  16. Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

    OpenAIRE

    Dorf, M.; H. Bösch; B. Naujokat; Pommereau, J. P.; Van Roozendael, M.; C. Sioris; F. Stroh; Weidner, F.; K. Pfeilsticker; Butz, A.; Camy-Peyret, C.; Chipperfield, M. P.; Engel, A.; Goutail, F.; Grunow, K.

    2006-01-01

    For the first time, results of four stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include ( a) balloon-borne in situ...

  17. Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric PM

    Directory of Open Access Journals (Sweden)

    S. Moukhtar

    2011-05-01

    Full Text Available A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter (PM is presented. It has been found in numerous laboratory studies that these compounds are photooxidation products of toluene in PM. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. PM was collected on quartz fibre filters using dichotomous high volume air samplers for PM 2.5. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography (HPLC and solid phase extraction (SPE. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyltrifluoroacetamide (BSTFA, was added to the solution for Gas Chromatography/Mass Spectroscopy (GC/MS analysis. The second half of the sample was stored at low temperature. When GC/MS analysis showed high enough concentrations the remaining sample was derivatized with BSTFA and analysed for stable isotope ratio using a Gas Chromatography/Isotope Ratio Mass Spectrometry (GC-IRMS. <br>> In all atmospheric PM samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol. Nevertheless, due to low pollution levels occurring in the rural area, no samples had concentrations high enough to perform stable carbon isotope composition measurements of the methylnitrophenols. Samples collected in the suburban area could be analysed for carbon stable isotope ratio using GC-IRMS. <br>> The procedure described in this paper provides a very sensitive and selective method for the analysis of methylnitrophenols in atmospheric PM at concentrations as low as 1 pg m−3. For accurate (within ±0.5‰ stable isotope ratio analysis significantly higher concentrations in the range of 100 pg m−3 or more are required.

  18. Isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    The mechanisms producing isotopic contamination in the electromagnetic separation of isotopes are studied with the aid of the Separator of Saclay and an electrostatic analyzer in cascade. After a separate investigation the result of which is that no contamination comes from the spreading of initial energies of ions, two principal mechanisms are emphasized; scattering and instability of the regime of the sources. The characters of each type of contamination arising from both mechanisms are described in some detail. An unique scheme of isotopic contamination is then derived from the partial ones. This scheme is successfully verified in several experimental separations. The applications concern principally the performances of magnetic cascades and more complex apparatus. It is found that the isotopic purities that such machines can deliver are extremely high. (author)

  19. [Isotopic composition of the delta-18O--delta-13C from the otoliths of reef fish from Taiaro (Tuamotu, French Polynesia): isotopic and biological implications].

    Science.gov (United States)

    Blamart, Dominique; Escoubeyrou, Karine; Juillet-Leclerc, Anne; Ouahdi, Rabia; Lecomte-Finiger, Raymonde

    2002-02-01

    Nuclei (larval stage) and outer parts (adult stage) of fish otoliths from the Taiaro closed lagoon (French Polynesia) and adjacent ocean have been analysed for the C-O isotopic compositions. delta 18O values of the nuclei of both populations indicate that isotopic equilibrium is reached. This implies that the lagoonal fish population has done its complete biological cycle in the lagoon and represents an adaptation in a closed system. delta 18O values of the outer parts show a slight isotopic disequilibrium (< 0.2@1000) interpreted in term of vital effect. All the delta 13C values exhibit a strong isotopic disequilibrium related to metabolic activity. PMID:11980181

  20. Stable isotope compositions (O-C) of reef fish otoliths from the Taiaro lagoon (Tuamotu, French Polynesia): isotopic and biologic implications

    International Nuclear Information System (INIS)

    Nuclei (larval stage) and outer parts (adult stage) of fish otoliths from the Taiaro closed lagoon (French Polynesia) and adjacent ocean have been analysed for the C-O isotopic compositions. δ18O values of the nuclei of both populations indicate that isotopic equilibrium is reached. This implies that the lagoonal fish population has done its complete biological cycle in the lagoon and represents an adaptation in a closed system. δ18O values of the outer parts show a slight isotopic disequilibrium (13C values exhibit a strong isotopic disequilibrium related to metabolic activity. (authors)

  1. Combinatorial effects on clumped isotopes and their significance in biogeochemistry

    Science.gov (United States)

    Yeung, Laurence Y.

    2016-01-01

    The arrangement of isotopes within a collection of molecules records their physical and chemical histories. Clumped-isotope analysis interrogates these arrangements, i.e., how often rare isotopes are bound together, which in many cases can be explained by equilibrium and/or kinetic isotope fractionation. However, purely combinatorial effects, rooted in the statistics of pairing atoms in a closed system, are also relevant, and not well understood. Here, I show that combinatorial isotope effects are most important when two identical atoms are neighbors on the same molecule (e.g., O2, N2, and D-D clumping in CH4). When the two halves of an atom pair are either assembled with different isotopic preferences or drawn from different reservoirs, combinatorial effects cause depletions in clumped-isotope abundance that are most likely between zero and -1‰, although they could potentially be -10‰ or larger for D-D pairs. These depletions are of similar magnitude, but of opposite sign, to low-temperature equilibrium clumped-isotope effects for many small molecules. Enzymatic isotope-pairing reactions, which can have site-specific isotopic fractionation factors and atom reservoirs, should express this class of combinatorial isotope effect, although it is not limited to biological reactions. Chemical-kinetic isotope effects, which are related to a bond-forming transition state, arise independently and express second-order combinatorial effects related to the abundance of the rare isotope. Heteronuclear moeties (e.g., Csbnd O and Csbnd H), are insensitive to direct combinatorial influences, but secondary combinatorial influences are evident. In general, both combinatorial and chemical-kinetic factors are important for calculating and interpreting clumped-isotope signatures of kinetically controlled reactions. I apply this analytical framework to isotope-pairing reactions relevant to geochemical oxygen, carbon, and nitrogen cycling that may be influenced by combinatorial

  2. Sulfur isotope analyses of individual aerosol particles in the urban aerosol at a central European site (Mainz, Germany

    Directory of Open Access Journals (Sweden)

    B. Winterholler

    2008-05-01

    Full Text Available Sulfur isotope analysis of atmospheric aerosols is a well established tool for identifying sources of sulfur in the atmosphere, estimating emission factors, and tracing the spread of sulfur from anthropogenic sources through ecosystems. Conventional gas mass spectrometry averages the isotopic compositions of several different types of sulfur aerosol particles, and therefore masks the individual isotopic signatures. In contrast, the new single particle technique presented here determines the isotopic signature of the individual particles. <br>> Primary aerosol particles retain the original isotopic signature of their source. The isotopic composition of secondary sulfates depends on the isotopic composition of precursor SO2 and the oxidation process. The fractionation with respect to the source SO2 is −9‰ for homogeneous and +16.5‰ for heterogeneous oxidation. The sulfur isotope ratio of secondary sulfate particles can therefore be used to identify the oxidation pathway by which this sulfate was formed. With the new single particle technique, different types of primary and secondary sulfates were first identified based on their chemical composition, and then their individual isotopic signature was measured separately. Our samples were collected in Mainz, Germany, in an urban environment. Secondary sulfates (ammonium sulfate, gypsum, mixed sulfates and coatings on silicates or organic aerosol dominated sulfate loadings in our samples. Comparison of the chemical and isotopic composition of secondary sulfates showed that the isotopic composition was homogeneous, independent of the chemical composition. This is typical for particles that derive from in-cloud processing. The isotopic composition of the source SO2 of secondary sulfates was calculated based on the isotopic composition of particles with known oxidation pathway and showed a strong dependence on wind direction. The contribution of heterogeneous

  3. Molecular dynamics simulations of Si etching in Cl- and Br-based plasmas: Cl+ and Br+ ion incidence in the presence of Cl and Br neutrals

    International Nuclear Information System (INIS)

    Classical molecular dynamics (MD) simulations have been performed for Cl+ and Br+ ions incident on Si(100) surfaces with Cl and Br neutrals, respectively, to gain a better understanding of the ion-enhanced surface reaction kinetics during Si etching in Cl- and Br-based plasmas. The ions were incident normally on surfaces with translational energies in the range Ei = 20–500 eV, and low-energy neutrals of En = 0.01 eV were also incident normally thereon with the neutral-to-ion flux ratio in the range Γn0/Γi0 = 0–100, where an improved Stillinger--Weber potential form was employed for the interatomic potential concerned. The etch yields and thresholds presently simulated were in agreement with the experimental results previously reported for Si etching in Cl2 and Br2 plasmas as well as in Cl+, Cl2+, and Br+ beams, and the product stoichiometry simulated was consistent with that observed during Ar+ beam incidence on Si in Cl2. Moreover, the surface coverage of halogen atoms, halogenated layer thickness, surface stoichiometry, and depth profile of surface products simulated for Γn0/Γi0 = 100 were in excellent agreement with the observations depending on Ei reported for Si etching in Cl2 plasmas. The MD also indicated that the yield, coverage, and surface layer thickness are smaller in Si/Br than in Si/Cl system, while the percentage of higher halogenated species in product and surface stoichiometries is larger in Si/Br. The MD further indicated that in both systems, the translational energy distributions of products and halogen adsorbates desorbed from surfaces are approximated by two Maxwellians of temperature T1 ≈ 2500 K and T2 ≈ 7000–40 000 K. These energy distributions are discussed in terms of the desorption or evaporation from hot spots formed through chemically enhanced physical sputtering and physically enhanced chemical sputtering, which have so far been speculated to both occur in the ion-enhanced surface reaction

  4. Molecular dynamics simulations of Si etching in Cl- and Br-based plasmas: Cl+ and Br+ ion incidence in the presence of Cl and Br neutrals

    Science.gov (United States)

    Nakazaki, Nobuya; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

    2015-12-01

    Classical molecular dynamics (MD) simulations have been performed for Cl+ and Br+ ions incident on Si(100) surfaces with Cl and Br neutrals, respectively, to gain a better understanding of the ion-enhanced surface reaction kinetics during Si etching in Cl- and Br-based plasmas. The ions were incident normally on surfaces with translational energies in the range Ei = 20-500 eV, and low-energy neutrals of En = 0.01 eV were also incident normally thereon with the neutral-to-ion flux ratio in the range Γn0/Γi0 = 0-100, where an improved Stillinger--Weber potential form was employed for the interatomic potential concerned. The etch yields and thresholds presently simulated were in agreement with the experimental results previously reported for Si etching in Cl2 and Br2 plasmas as well as in Cl+, Cl2+, and Br+ beams, and the product stoichiometry simulated was consistent with that observed during Ar+ beam incidence on Si in Cl2. Moreover, the surface coverage of halogen atoms, halogenated layer thickness, surface stoichiometry, and depth profile of surface products simulated for Γn0/Γi0 = 100 were in excellent agreement with the observations depending on Ei reported for Si etching in Cl2 plasmas. The MD also indicated that the yield, coverage, and surface layer thickness are smaller in Si/Br than in Si/Cl system, while the percentage of higher halogenated species in product and surface stoichiometries is larger in Si/Br. The MD further indicated that in both systems, the translational energy distributions of products and halogen adsorbates desorbed from surfaces are approximated by two Maxwellians of temperature T1 ≈ 2500 K and T2 ≈ 7000-40 000 K. These energy distributions are discussed in terms of the desorption or evaporation from hot spots formed through chemically enhanced physical sputtering and physically enhanced chemical sputtering, which have so far been speculated to both occur in the ion-enhanced surface reaction kinetics of plasma etching.

  5. Isotope enrichment systems

    International Nuclear Information System (INIS)

    This invention provides a system in which both phases of the countercurrent contact isotope exchange concentration process are recycled continuously and an isotope depleted liquid phase substance thereof has its prior content of the desired isotope of hydrogen and/or oxygen replenished in an isotope regenerator by direct contact isotope exchange with a flow of steam from a source external to the concentrating process, whereby such replenished liquid serves as the feed liquid for the concentration process. As the supply of steam is gaseous, all problems incident to mineral solids in solution in liquid water are eliminated. As the elevated temperature corresponds to that of the steam, the isotope replenishment of the process feed liquid may be conducted without materially altering the characteristics of the steam for use as an energy source in any system

  6. Isotopes in Australian environmental analysis

    International Nuclear Information System (INIS)

    amount of surface water that can be utilised in a particular catchment, but that is not the case for groundwater, leading to tension amongst users in connected systems. Isotopes such as the stable and radioactive isotopes of water and carbon are particularly appropriate for the study of our dry landscape in its connected water systems, providing a clear method of determining the source of groundwater, and hence the extent of mixing of nearby surface water and the time frame for the mixing process. In particular, the stable isotopes 2H, 18O, and 13C provide a robust end-member analysis for the hydrographical separation of regional groundwater and any amount of river water which was replenished at a remote location; while the radioactive isotopes 3H and 14C are used to confirm the presence in groundwater of (isotopically modern) surface water, but also accurately determine the apparent rate of mixing at particular distances from the river. Isotope tracer techniques have been applied to study the fate, pathways and risks associated with contaminants and particulates in coastal aquatic systems. Examples include: (i) sand and sediment tracing in coasts and estuaries using radiotracers such as 192Ir labelled sand (MacMasters Beach, NSW) or neutron activatable tracers such as 115In (Homebush Bay, Sydney); (ii) biokinetics of environmental contaminants in aquatic and terrestrial systems have been investigated using radionuclides such as 109Cd, 65Zn and 210Pb; (iii) tracing of sewage effluent from Australian coastal outfalls undertaken using radioisotope tracers such as 198Au and tritiated water; and (iv) groundwater dynamics under tidal forcing using a short-lived radioisotope tracer 82Br to track groundwater movement in three dimensions (Hat Head, NSW). Accelerator Mass Spectrometry is still the only technique able to determine extremely low concentrations (-12) of long- lived radioisotopes in small (mg) environmental samples. In Australia, radiocarbon dating is used for the

  7. Examination of the bioaccumulation of halogenated dimethyl bipyrroles in an Arctic marine food web using stable nitrogen isotope analysis.

    Science.gov (United States)

    Tittlemier, Sheryl A; Fisk, Aaron T; Hobson, Keith A; Norstrom, Ross J

    2002-01-01

    Concentrations of four possibly naturally produced organohalogens--1,1'-dimethyl-3,3',4-tribromo-4,5,5'-trichloro-2,2'-bipyrrole (DBP-Br3Cl3), 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), 1,1'-dimethyl-3,3',4,4',5-pentabromo-5'-chloro-2,2'-bipyrrole (DBP-Br5Cl) and 1,1'-dimethyl-3,3',4,4',5,5'-hexabromo-2,2'-bipyrrole (DBP-Br6)--were quantitated and the extent of their magnification through an entire Arctic marine food web [measured as integrated trophic magnification factors (TMFs)] were calculated. The food web consisted of three zooplankton species (Calanus hyperboreus, Mysis oculata, and Sagitta sp.), one fish species [Arctic cod (Boreogadus saida)], four seabird species [dovekie (Alle alle), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), and glaucous gull (Larus hyperboreus)], and one marine mammal species [ringed seal (Phoca hispida)]. Trophic levels in the food web were calculated from ratios of stable isotopes of nitrogen (15N/14N). All halogenated dimethyl bipyrrole (HDBP) congeners were found to significantly (Ptrophic level in the invertebrate--fish--seabird food web. DBP-Br4Cl2 (TMF= 14.6) was found to biomagnify to a greater extent than DBP-Br3Cl3 (TMF = 5.2), DBP-Br5Cl (TMF = 6.9), or DBP-Br6 (TMF = 7.0), even though the Kow of DBP-Br4CI2 was predicted to be lower than those of DBP-Br5Cl and DBP-Br6. None of the four HDBP congeners in ringed seals followed the general trend of increasing concentration with trophic level, which was possibly due to an ability of the seals to metabolize HDBPs. PMID:11808557

  8. Uses of stable isotopes

    International Nuclear Information System (INIS)

    The most important fields of stable isotope use with examples are presented. In isotope dilution analysis the stable isotopes are used in trace analysis, measurements of volumes and masses. In the field of stable isotope use as tracers the following applications are encountered: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic. In the domain of isotope equilibrium effects applications in the study of mechanism of drug action, study of natural processes, investigation of equilibrium conditions and water cycle as well as in temperature measurements are encountered. Stable isotopes are also used in advanced nuclear reactors, particularly, the uranium nitride with 15 N as nuclear fuel and 157 Gd for reactor control. In spite of some difficulties of stable isotope use, especially related to analytical techniques, which are slow and expensive, the number of papers reporting this subject is steadily growing as well the number of scientific meetings organized by International Isotope Society and IAEA, Gordon Conferences, and regional meetings in Germany, France, etc. Stable isotope application development on large scale is ensured by improving their production technologies, as well as by development of new labelled compounds and of analytical techniques. (author)

  9. Isotopes in hydrogeology

    International Nuclear Information System (INIS)

    Questions of the application of radioactive isotopes in hydrogeology and seismology are considered, as well as their physico-chemical and geochemical properties and the regularities of their occurrence and migration in natural waters. The possibility of application of these isotopes in calculating the age of waters and in solving paleohydrogeological problems is studied. Elucidated are questions of utilization of helium and uranium isotope content in determining the effect of faults on the hydrogeological conditions of regions and in selecting burial sites for industrial wastes. Utilization of changes in the isotopic and gas composition of underground waters during the activization of tectonic movements for earthquake forecasts is considered

  10. PRINCIPAL ISOTOPE SELECTION REPORT

    International Nuclear Information System (INIS)

    Utilizing nuclear fuel to produce power in commercial reactors results in the production of hundreds of fission product and transuranic isotopes in the spent nuclear fuel (SNF). When the SNF is disposed of in a repository, the criticality analyses could consider all of the isotopes, some principal isotopes affecting criticality, or none of the isotopes, other than the initial loading. The selected set of principal isotopes will be the ones used in criticality analyses of the SNF to evaluate the reactivity of the fuel/waste package composition and configuration. This technical document discusses the process used to select the principal isotopes and the possible affect that these isotopes could have on criticality in the SNF. The objective of this technical document is to discuss the process used to select the principal isotopes for disposal criticality evaluations with commercial SNF. The principal isotopes will be used as supporting information in the ''Disposal Criticality Analysis Methodology Topical Report'' which will be presented to the United States Nuclear Regulatory Commission (NRC) when approved by the United States Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM)

  11. The isotope breathe test

    International Nuclear Information System (INIS)

    The foundations of the breath diagnostic test, based on application of the carbon compounds, labeled with the stable (13C) or radioactive isotope are presented. The methodology for conducting the breath isotope test and the apparatuses, making it possible to determine under clinical conditions the isotope composition of the carbon, contained in the expired air, depending on the introduced tracer type, is briefly described. The safety of the method and prospects of its application are discussed. The examples of the breath isotope test practical application are presented

  12. Closed Claim Query File

    Data.gov (United States)

    Social Security Administration — This file is used to hold information about disability claims that have been closed and have been selected for sampling.Sampling is the process whereby OQR reviews...

  13. Mitigation : Closed Basin Project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The upcoming meeting on waterfowl mitigation for the Closed Basin Project will have several people talk about possible changes to the waterfowl mitigation program....

  14. Atmospheric test of the J(BrONO2)/kBrO+NO2 ratio: implications for total stratospheric Bry and bromine-mediated ozone loss

    Science.gov (United States)

    Kreycy, S.; Camy-Peyret, C.; Chipperfield, M. P.; Dorf, M.; Feng, W.; Hossaini, R.; Kritten, L.; Werner, B.; Pfeilsticker, K.

    2013-07-01

    We report on time-dependent O3, NO2 and BrO profiles measured by limb observations of scattered skylight in the stratosphere over Kiruna (67.9° N, 22.1° E) on 7 and 8 September 2009 during the autumn circulation turn-over. The observations are complemented by simultaneous direct solar occultation measurements around sunset and sunrise performed aboard the same stratospheric balloon payload. Supporting radiative transfer and photochemical modelling indicate that the measurements can be used to constrain the ratio J(BrONO2)/kBrO+NO2, for which at T = 220 ± 5 K an overall 1.7 (+0.4 -0.2) larger ratio is found than recommended by the most recent Jet Propulsion Laboratory (JPL) compilation (Sander et al., 2011). Sensitivity studies reveal the major reasons are likely to be (1) a larger BrONO2 absorption cross-section σBrONO2, primarily for wavelengths larger than 300 nm, and (2) a smaller kBrO+NO2 at 220 K than given by Sander et al. (2011). Other factors, e.g. the actinic flux and quantum yield for the dissociation of BrONO2, can be ruled out. The observations also have consequences for total inorganic stratospheric bromine (Bry) estimated from stratospheric BrO measurements at high NOx loadings, since the ratio J(BrONO2)/kBrO+NO2 largely determines the stratospheric BrO/Bry ratio during daylight. Using the revised J(BrONO2)/kBrO+NO2 ratio, total stratospheric Bry is likely to be 1.4 ppt smaller than previously estimated from BrO profile measurements at high NOx loadings. This would bring estimates of Bry inferred from organic source gas measurements (e.g. CH3Br, the halons, CH2Br2, CHBr3, etc.) into closer agreement with estimates based on BrO observations (inorganic method). The consequences for stratospheric ozone due to the revised J(BrONO2)/kBrO+NO2 ratio are small (maximum -0.8%), since at high NOx (for which most Bry assessments are made) the enhanced ozone loss by overestimating Bry is compensated for by the suppressed ozone loss due to the underestimation

  15. Isotope hydrochemical investigation of saline intrusion in coastal aquifer of Karachi-Pakistan

    International Nuclear Information System (INIS)

    . Further, the deep groundwater is quite saline. In general, the bacteriological quality of deep groundwater is good except in case of pumping wells installed either within highly populated and poorly drained areas or close to the polluted rivers. The hydrochemical and stable isotope results indicates that the confined aquifer hosts a mixture of rainwater from hinterlands and surrounding regions around coastal Karachi as well as sea trapped water/seawater through intrusion under natural infiltration conditions or under induced recharge conditions. The present investigations prove seawater intrusion/existence of trapped seawater salinity and build- up of salt-water up-coning in the shallow and deep confined aquifer in coastal Karachi. Similar observations have been made by Yurtsever and Payne for shallow and deep groundwater and the local seawater as well as seawater from Doha-Qatar in the Gulf area. The postulation of seawater intrusion or build-up of salt-water up-coning and/or existence of trapped seawater salinity in the deep confined aquifer will be validated upon additional isotopic analysis such as δ34S (aqueous sulfate), tritium (3H) and radiocarbon (14C) content, as well as Cl-/Br- ratio of surface water and groundwater samples in coastal Karachi. (author)

  16. Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Nimz, G. J., LLNL

    1998-06-01

    also be treated as a mostly closed system for mass balance considerations. It is the near closure of the system that permits well- constrained chemical mass balance calculations to be made. These calculations generally focus of lithogenic solutes, and therefore in our discussions of lithogenic nuclides in the paper, the concept of chemical mass balance in a nearly dosed system will play an important role. Examination of the isotopic compositions of solutes provides a better understanding of the variety of processes controlling mass balance. It is with this approach that we examined the variety of processes occurring within the catchment system, such as weathering and soil production, generation of stormflow and streamflow (hydrograph separation), movement of soil pore water, groundwater flow, and the overall processes involved with basinal water balance. In this paper, the term `nuclide` will be used when referring to a nuclear species that contains a particular number of protons and neutrons. The term is not specific to any element. The term `isotope` will be used to distinguish nuclear species of a given element (atoms with the same number of protons). That is to say, there are many nuclides in nature - for example, {sup 36}Cl, {sup 87}Sr, {sup 238}U; the element has four naturally-occurring isotopes - {sup 87}Sr, and {sup 88}Sr. This paper will first discuss the general principles that underlie the study of lithogenic and cosmogenic nuclides in hydrology, and provide references to some of the more important studies applying these principles and nuclides. We then turn in the second section to a discussion of their specific applications in catchment- scale systems. The final section of this paper discusses new directions in the application of lithogenic and cosmogenic nuclides to catchment hydrology, with some thoughts concerning possible applications that still remain unexplored.

  17. High-resolution continuum source electrothermal absorption spectrometry of AlBr and CaBr for the determination of bromine

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Heitmann, Uwe [ISAS - Institute for Analytical Sciences, Department of Interface Spectroscopy, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Okruss, Michael [Gesellschaft zur Foerderung angewandter Optik, Optoelektronik, Quantenelektronik und Spektroskopie (GOS) e.V., Rudower Chaussee 29, 12489 Berlin (Germany)], E-mail: okruss@isas.de

    2008-05-15

    Molecular absorption spectra of AlBr and CaBr, produced in a graphite furnace, were investigated using a high-resolution echelle spectrometer equipped with a xenon short-arc lamp as continuum source. The analytical usability of the spectra for the determination of bromine was studied. To this end, the molecular absorptions of AlBr at 278.914 nm and CaBr at 625.315 nm were evaluated. Apart from strong absorption bands of CaF around 625.3 nm, which disturb the use of CaBr, no spectral interferences were observed for both AlBr and CaBr. Regarding chemical interference with matrix substances, the molecular absorption of AlBr and CaBr is influenced in a different way. While the sensitivity of the CaBr absorption is susceptible to chloride, aluminum, potassium and sodium ions, there is no significant effect on the AlBr absorption. In contrast, the inorganic acids (nitric, phosphoric, and sulfuric) have an influence on AlBr, but not on the CaBr molecular absorption. Therefore, the two methods complement each other and each has its own application area. Regarding real samples, a salt sample from the death sea and an organic pharmaceutical were evaluated. The results were in good agreement with those derived from two independent methods and with an existing reference value. Relative standard deviations were found in the range of 5%. The limit of detection for bromine was about 2 ng for both AlBr and CaBr molecular absorption; the dynamic range was linear at least up to 250 ng Br.

  18. Fine-structure energy levels and lifetimes in Br XXIV

    Energy Technology Data Exchange (ETDEWEB)

    Tayal, Vikas; Gupta, G P [Department of Physics, SD (Postgraduate) College, Muzaffarnagar, UP (India)

    2005-11-28

    We have performed large-scale CIV3 calculations of excitation energies from the ground state for 48 fine-structure levels as well as of oscillator strengths and radiative decay rates for all electric-dipole-allowed and intercombination transitions among the (1s{sup 2}2s{sup 2}2p{sup 6})3s{sup 2}({sup 1}S), 3s3p({sup 1,3}P{sup o}), 3s3d({sup 1,3}D), 3s4s({sup 1,3}S), 3s4p({sup 1,3}P{sup o}), 3s4d({sup 1,3}D), 3s4f({sup 1,3}F{sup o}), 3p{sup 2}({sup 1}S, {sup 3}P, {sup 1}D), 3p3d({sup 1,3}P{sup o}, {sup 1,3}D{sup o}, {sup 1,3}F{sup o}), 3p4s({sup 1,3}P{sup o}) and 3d{sup 2}({sup 1}S, {sup 3}P, {sup 1}D) states of Br XXIV. These states are represented by extensive configuration-interaction (CI) wavefunctions obtained using the CIV3 computer code of Hibbert. The relativistic effects in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian which consists of the non-relativistic term plus the one-body mass correction, Darwin term, and spin-orbit, spin-other-orbit and spin-spin operators. Small adjustments to the diagonal elements of the Hamiltonian matrices have been made so that the energy splittings are as close as possible to the experimental values. Our calculated excitation energies, including their ordering, are in excellent agreement with the available experimental results except that the levels {sup 1}D{sub 2} and {sup 3}P{sub 2} belonging to the same configuration 3p{sup 2} interchanged their positions compared to the experiment. This interchange in our calculation is discussed and explained through eigenvector compositions of the two levels. From our radiative decay rates, we have calculated radiative lifetimes of some fine-structure levels. Our calculated lifetimes of the levels 3s3p({sup 3}P{sub 1}) and 3s3p({sup 1}P{sub 1}) are found to be in good agreement with the experimental and other theoretical results. In this calculation we also predict new data for several fine-structure levels where no other theoretical and experimental

  19. Pyroelectric and Dilatometric Studies on the Low Temperature Ferroelectric Phase Transition of (CH3NH3)5Bi2Br11

    Science.gov (United States)

    Dziedzic, J.; Mróz, J.; Jakubas, R.

    2006-09-01

    The results of the linear thermal expansion studies on (CH3NH3)5Bi2Br11 single crystals in the temperature range 60-340 K are presented. The thermal anomaly in the vicinity of 77 K is assigned to the phase transition classified as close to first order type. The pyroelectric measurements of (CH3NH3)5Bi2Br11 were carried out in the range of 45-320 K along the a- and c-axis. The step-like change in the spontaneous polarization along the a-axis at 77 K indicates a discontinuous character of ferroelectric transition.

  20. Lifetime measurement of 75Br with inverse kinematic reaction

    International Nuclear Information System (INIS)

    75Br is an isotone of 74Se and 76Kr. Both of them are known for showing shape coexistence with different shape in ground state. It is a question whether odd particle, in this case a proton in 75Br, stabilizes one of the shape or feel the shape co-existence of the core. Transitional probabilities and magnetic moment of the states will help in answering these questions. Thus it motivates us to re-measure the lifetime of excited states of ground state band of 75Br using inverse reaction and to provide necessary information about the feeding time of these states which can then be used in magnetic moment measurement

  1. Pressure-induced structural changes in NH4Br.

    Science.gov (United States)

    Huang, Yanping; Huang, Xiaoli; Li, Wenbo; Wang, Lu; Wu, Gang; Zhao, Zhonglong; Duan, Defang; Bao, Kuo; Zhou, Qiang; Liu, Bingbing; Cui, Tian

    2015-08-14

    We report angle dispersive X-ray diffraction (XRD) measurements and Raman spectroscopy on NH4Br up to 70.0 GPa at room temperature. Three thermodynamically stable phases (phases II, IV, and V) are confirmed and a new possible phase (phase VI) of P21/m symmetry is proposed whose structure was established from Rietveld refinement of synchrotron XRD data for the first time. The phase sequence observed in NH4Br is in accordance with phase II → IV → V → VI. Phase V transforms into phase VI at about 57.8 GPa with a huge volume reduction of 30%. Still, the intramolecular distances are analyzed to better understand the nature of structures. The H-H interactions become markedly more important as the N-Br distances are compacted, which is probably the reason of the kink of symmetric stretching band (ν1) at the transition pressure. PMID:26277143

  2. Pressure-induced structural changes in NH4Br

    International Nuclear Information System (INIS)

    We report angle dispersive X-ray diffraction (XRD) measurements and Raman spectroscopy on NH4Br up to 70.0 GPa at room temperature. Three thermodynamically stable phases (phases II, IV, and V) are confirmed and a new possible phase (phase VI) of P21/m symmetry is proposed whose structure was established from Rietveld refinement of synchrotron XRD data for the first time. The phase sequence observed in NH4Br is in accordance with phase II → IV → V → VI. Phase V transforms into phase VI at about 57.8 GPa with a huge volume reduction of 30%. Still, the intramolecular distances are analyzed to better understand the nature of structures. The H–H interactions become markedly more important as the N–Br distances are compacted, which is probably the reason of the kink of symmetric stretching band (ν1) at the transition pressure

  3. Henkilöbrändäyksen mahdollisuudet kauneudenhoitoalalla

    OpenAIRE

    Gallotti, Mirva

    2015-01-01

    Henkilöbrändäys on vielä suhteellisen uusi termi ja ilmiö Suomessa. Kuitenkin parin viime vuoden aikana aihe on ollut entistä useammin esillä mediassa. Kiristynyt tilanne työmarkkinoilla on pakottanut ihmisiä löytämään tapoja, joilla voi erottautua massasta ja luoda positiivista kuvaa itsestä. Henkilöbrändäystä voidaan kutsua oman osaamisen ja asiantuntijuuden profiloinniksi. Tämän opinnäytetyön tarkoitus oli tutkia olisiko henkilöbrändäyksestä apua työllistymiseen ja uralla etenemiseen myös ...

  4. Raman spectra of ZnBr2-based glasses

    International Nuclear Information System (INIS)

    Raman spectra of ZnBr2-KBr and ZnBr2-KBr-CaBr2 glasses contain strong bands at 60 cm-1 and 155 or 174 cm-1 and some weak bands between 200-300 cm-1. From the compositional dependence of the spectra and comparison with vibrational modes of molten mixtures and crystals, the 155 and 174 cm-1 bands are assigned to symmetric stretching modes of tetrahedra consisting of four bridging and four non-bridging bromines, respectively. It is revealed that tetrahedra of bridging bromines exist in the glasses even at the composition of so large amount of bromine that the theoretical number of non-bridging bromine per zinc is beyond 4. (author) 6 refs., 4 figs

  5. Thermal neutron imaging with CsBr storage phosphors

    International Nuclear Information System (INIS)

    The storage phosphor material CsBr:Eu2+ has been investigated for use in thermal neutron imaging. CsBr:Eu2+ imaging plates were prepared in a polycrystalline form by cold pressing starting powders. These as-prepared materials show only small photostimulated luminescence intensity under thermal neutron irradiation, but the luminescence intensity can be increased by incorporating separate neutron converters, in the form of lithium, boron or gadolinium containing compounds. An imaging plate containing 5% 10B2O3 as a neutron converter has 50% the photostimulated luminescence intensity of a commercial Fuji neutron imaging plate. Thermal neutron imaging was shown to be possible with the CsBr:Eu2+-based imaging plates, and the differences in thermal neutron and X-ray images were clearly observed

  6. Influence of Biofield Energy Treatment on Isotopic Abundance Ratio in Aniline Derivatives

    OpenAIRE

    Mahendra Kumar Trivedi; Alice Branton; Dahryn Trivedi; Gopal Nayak

    2015-01-01

    The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of 13C/12C or 2H/1H or 15N/14N ≡ (PM+1)/PM in aniline; and (PM+1)/PM and 81Br/79Br ≡ (PM+2)/PM in 4-bromoaniline using Gas Chromatography-Mass Spectrometry (GC-MS). Aniline and 4-bromoaniline samples were divided into two parts: control and treated. The control part remained as untreated, while the treated part was subjected to Mr. Trivedi’s biofield energy treatment. The ...

  7. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  8. Discovery of the Mercury Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2009-01-01

    Forty mercury isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  9. Discovery of the Einsteinium Isotopes

    OpenAIRE

    Bury, A.; Fritsch, A; Ginepro, J. Q.; Heim, M; Schuh, A.; Shore, A.; Thoennessen, M.

    2009-01-01

    Seventeen einsteinium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  10. Discovery of the Titanium Isotopes

    OpenAIRE

    Meierfrankenfeld, D.; Thoennessen, M.

    2009-01-01

    Twentyfive titanium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  11. Discovery of the Scandium Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2010-01-01

    Twenty-three scandium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  12. Discovery of the Tungsten Isotopes

    OpenAIRE

    A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  13. Discovery of the Vanadium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-four vanadium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  14. Discovery of the Arsenic Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Discovery of the Barium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the Silver Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-eight silver isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the Cadmium Isotopes

    OpenAIRE

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Discovery of the Krypton Isotopes

    OpenAIRE

    Heim, M.; A. Fritsch; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-two krypton isotopes have been observed so far; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of the Iron Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Twenty-eight iron isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the Gold Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-six gold isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T; Thoennessen, M

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  2. Brändin kehittäminen : Even juoksukoulu

    OpenAIRE

    Koli, Eveliina

    2016-01-01

    Tämän opinnäytetyön tavoitteena oli selkeyttää Even juoksukoulun brändin tavoitemielikuvaa. Opinnäytetyön tutkimuksen avulla pyrittiin selvittämään Even juoksukoulun brändin tilannetta sekä luomaan sen avulla toiminnalle selkeä missio ja visio. Lisäksi tutkimuksen avulla haluttiin selvittää Even juoksukoulun tunnettavuutta. Even juoksukoulun tarkoituksena on tarjota monipuolisia harjoituksia, opastaa oikeaoppista tekniikkaa ja kehittää asiakkaiden tietämystä lihaskunnon ja liikkuvuuden tä...

  3. Brändin esiintyvyys blogeissa - Case Adidas

    OpenAIRE

    Kolehmainen, Tiia

    2013-01-01

    Tämän opinnäytetyön tarkoituksena oli selvittää adidas -brändin blogiesiintyvyys suomalaisissa blogeissa. Tutkimuksen tavoitteena oli saada käsitys siitä, millaisissa muodoissa adidas-brändi esiintyy Suomen suosituimmissa blogeissa. Tutkimuksessa tutkittiin myös Adidaksen kampanjan blogiesiintyvyyttä. Opinnäytetyön toimeksiantajana toimi Adidas Suomi Oy, joka on osa globaalia Adidas Groupia. Yritys on yksi maailman johtavimmista urheilutuotemerkeistä. Tutkimuksen teoreettisessa osuud...

  4. The BR1 Reactor:. a Versatile Tool for Fission Experiments

    Science.gov (United States)

    Wagemans, J.

    2008-04-01

    The BR1 reactor located at the Belgian Nuclear Research Centre SCK·CEN in Mol, Belgium, is a research reactor with a variety of irradiation possibilities. Thanks to its large reactor core, its flexible operation and its different irradiation facilities, this reactor is particularly suited for in-core and ex-core neutron physics experiments. This paper gives a general description of the BR1 reactor, with special emphasis on the available irradiation possibilities. Then some examples of fission experiments that have been performed in the past will be referred to and two ongoing projects related to fission will be presented.

  5. Brändit kustannustoiminassa CASE: Arktinen Banaani

    OpenAIRE

    Pursiainen, Anna-Liisa

    2010-01-01

    Brändien rakentaminen on aina kovaa ja systemaattista työtä toimialasta riippumatta. Yritykset kehittävät tuotteita ja koko toimintaa kysyntä- ja markkinalähtöisesti. Perinteisillä toimialoilla jollaiseksi myös kustannusala voidaan lukea, toimintaa ja kehitystyötä on viime aikoina tehty jatkuvien muutosten parissa. Suuret kustannusyhtiöt ovat ostaneet pienempiä samalla kun osa yhtiöistä on kiristyvän kilpailutilanteen vuoksi lopettanut toimintansa. Tuotteistaminen ja brändin luominen ...

  6. Skandaalin vaikutus brändin imagoon - Case Audi

    OpenAIRE

    Puntalo, Ville-Veikko

    2016-01-01

    Opinnäytetyössä tutkittiin Volkswagenin päästöhuijausskandaalin vaikutusta Audi-brändin imagoon. Tutkimuksessa pyrittiin selvittämään onko ennakoitavissa mahdollisia myyntitulosten muutoksia ja johtuivatko ne kyseisestä skandaalista. Opinnäytetyön teoriaosuudessa perehdyttiin ostokäyttäytymisen prosessiin, brändin rakentumiseen, positiivisen maineen saavuttamiseen ja tunnettuihin yritysmaailman skandaaleihin. Lisäksi käytiin läpi Volkswagen päästöskandaalin taustaa sekä sen seurauksia. ...

  7. Brändistrategian merkitys yrityksen digitaalisessa markkinoinnissa

    OpenAIRE

    Niskala, Harri

    2011-01-01

    Tämä tutkielma on kirjoitettu siksi, että olen aikaisemmin työskennellyt digitaalista markkinointia myyvän yrityksen palveluksessa. Kyseinen työnantaja, Advertising Media Finland Oy, on ollut tämän tutkielman toimeksiantaja. Työn tavoitteena oli selvittää, kuinka suuri merkitys brändistrategialla on suomalaisissa yrityksissä. Lisäksi pyrittiin selvittämään, mikä on suomalaisten yritysten brändi-identiteetin ja imagon merkitys digitaalisessa markkinoinissa. Näiden kahden asian lisäksi selvitet...

  8. Stable isotopes in river ice: identifying primary over-winter streamflow signals and their hydrological significance

    Science.gov (United States)

    Gibson, J. J.; Prowse, T. D.

    2002-03-01

    The process of isotopic fractionation during freezing in the riverine environment is discussed with reference to a multi-year isotope sampling survey conducted in the Liard-Mackenzie River Basins, northwestern Canada. Systematic isotopic patterns are evident in cores of congelation ice (black ice) obtained from rivers and from numerous tributaries that are recognized as primary streamflow signals but with isotope offsets close to the equilibrium ice-water fractionation. The results, including comparisons with the isotopic composition of fall and spring streamflow measured directly in water samples, suggest that isotopic shifts during ice-on occur due to gradual changes in the fraction of flow derived from groundwater, surface water and precipitation sources during the fall to winter recession. Low flow isotopic signatures during ice-on suggest a predominantly groundwater-fed regime during late winter, whereas low flow isotopic signatures during ice-off reflect a mixed groundwater-, surface water- and precipitation-fed regime during late fall.

  9. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  10. (Carbon isotope fractionation inplants)

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  11. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  12. Variation of Br-in groundwater and its relationship with other main ions along eastern coast of Leizhou peninsular%雷州半岛东岸地下水 Br-变化及其与宏量离子的关系研究

    Institute of Scientific and Technical Information of China (English)

    黄向青; 甘华阳; 路剑飞; 张顺枝; 潘毅

    2014-01-01

    According to the lab data on groundwater samples during two tidal cycles from monitoring wells J1 and J2 along eastern coast of Leizhou Peninsular , the paper analyzed the anion Br -'s concentration , variation and relationship with other main ions .The results demonstrate that Br -comes mainly from sea-water intrusion, and the basic types of measured well are Na +K· Ca· Mg-Cl· SO4 , and the types of J2 is Na+K· Ca· Mg-Cl· SO4· HCO3;the average content of Br -in J1 is 11.69~14.35mg/L and the concentration of Br -in J2 is almost half in J1's.Br -statistical characteristics every well change with the number of measurement .Combined with the ratio of Br -/Cl -and the invironment of measured well , it is thought that J1 primarily has sea-phase and J2 has river-sea phase in term of Br -/Cl -;Br -owns al-most the same relative amplitudes with Cl -and SO4 2-,which show Br -also actively takes part in the process of seawater intrusion;the correlation of Br -with other ions also varies with wells and the ratio of Br-to Na +is the lowest among the ratio of Br -to cations.the highest is K +;the ratio of Br -to Mg2+is in the meantime .The frequency in the region of milligram equivalent ratio chiefly appears the distribu-tion forms of left lean, sharp peak and flat peak , especially in well J2, the ratio ofγBr -/γK+is close to normal .The relativity of milligram equivalent ratio and mass equivalent ratio is consistent .The linear rela-tionship between Br -/Na +and Br -/Cl -is good.The paper finally made linear LST fitness .%依据雷州半岛东岸J1、J2测井地下水潮周期取样测试数据,对Br-含量、变化及其与其它宏量离子的关系进行了分析。结果显示:Br-主要来源于海水侵染,测井基本类型为 Na +K · Ca · Mg -Cl · SO4, J2为Na+K· Ca· Mg-Cl· SO4· HCO3。 J1测井Br-平均含量为11.69~14.35 mg/L,J2测井Br-平均值约为J1的一半,各测井Br-统计特征随测次而有所变化。进一步结

  13. Synchrotron x-ray powder diffraction study of the structural phase transition in CaBr2

    International Nuclear Information System (INIS)

    The structures of CaBr2 have been investigated using high resolution synchrotron powder x-ray diffraction methods between room temperature and 800 deg. C. At room temperature CaBr2 has an orthorhombic CaCl2-type structure (Pnnm Z=2) with a=6.8847(1), b=6.5806(1), and c=4.3477(1) A. Heating above 560 deg. C results in a continuous transition to a tetragonal rutile type structure (P42/mnm Z=2) with a=6.810 95(7) A and c=4.417 70(5) A at 650 deg. C. Investigation, through either spontaneous strain or octahedral tilt angle, suggests that the transition is close to second order in nature, although the contribution from the sixth order term in the Landau potential cannot be neglected

  14. Selection of Isotopes and Elements for Fuel Cycle Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Piet

    2009-04-01

    Fuel cycle system analysis simulations examine how the selection among fuel cycle options for reactors, fuel, separation, and waste management impact uranium ore utilization, waste masses and volumes, radiotoxicity, heat to geologic repositories, isotope-dependent proliferation resistance measures, and so forth. Previously, such simulations have tended to track only a few actinide and fission product isotopes, those that have been identified as important to a few criteria from the standpoint of recycled material or waste, taken as a whole. After accounting for such isotopes, the residual mass is often characterized as “fission product other” or “actinide other”. However, detailed assessment of separation and waste management options now require identification of key isotopes and residual mass for Group 1A/2A elements (Rb, Cs, Sr, Ba), inert gases (Kr, Xe), halogens (Br, I), lanthanides, transition metals, transuranic (TRU), uranium, actinide decay products. The paper explains the rationale for a list of 81 isotopes and chemical elements to better support separation and waste management assessment in dynamic system analysis models such as Verifiable Fuel Cycle Simulation (VISION)

  15. Li isotope fractionation in peridotites and mafic melts

    Science.gov (United States)

    Jeffcoate, A. B.; Elliott, T.; Kasemann, S. A.; Ionov, D.; Cooper, K.; Brooker, R.

    2007-01-01

    We have measured the Li isotope ratios of a range of co-existing phases from peridotites and mafic magmas to investigate high-temperature fractionations of 7Li/ 6Li. The Li isotopic compositions of seven mantle peridotites, reconstructed from analyses of mineral separates, show little variation (δ 7Li 3.2-4.9‰) despite a wide range in fertility and radiogenic isotopic compositions. The most fertile samples yield a best estimate of δ 7Li ˜ 3.5‰ for the upper mantle. Bulk analyses of olivine separates from the xenoliths are typically ˜1.5‰ isotopically lighter than co-existing orthopyroxenes, suggestive of a small, high-temperature equilibrium isotope fractionation. On the other hand, bulk analyses of olivine phenocrysts and their host melts are isotopically indistinguishable. Given these observations, equilibrium mantle melting should generate melts with δ 7Li little different from their sources (style of zoning is also observed in the phenocrysts of holocrystalline Hawaiian lavas. More dramatically, a single orthopyroxene crystal from a San Carlos xenolith shows a W-shaped Li isotope profile with a 40‰ range in δ 7Li, close to the isotope variability seen in all terrestrial whole rock analyses. We attribute Li isotope zonation in mineral phases to diffusive fractionation of Li isotopes, within mineral phases and along melt pathways that pervade xenoliths. Given the high diffusivity of Li, the Li isotope profiles we observe can persist, at most, only a few years at magmatic temperatures. Our results thus highlight the potential of Li isotopes as a high-resolution geospeedometer of the final phases of magmatic activity and cooling.

  16. Modelling of stable water isotopes in Central Europe with COSMOiso

    Science.gov (United States)

    Christner, Emanuel; Pfahl, Stephan; Schädler, Gerd

    2016-04-01

    Atmospheric water in form of vapor or clouds is responsible for ˜75 % of the natural greenhouse effect and carries huge amounts of latent heat. For this reason, a best possible description of the hydrological cycle is a prerequisite for reliable climate modelling. As the stable isotopes H216O, H218O and HDO differ in vapor pressure, they are fractionated during phase changes and contain information about the formation of precipitation, evaporation from the ground, etc. Therefore, the isotopic composition of atmospheric water is an useful tracer to test and improve our understanding of the extremely complex and variable hydrological cycle in Earth's atmosphere. Within the project PalMod the isotope-enabled limited-area model COSMOiso will be used for high-resolution isotope simulations of paleo-climates. For validation with modern observations we compare 12 years of modelled isotope ratios from Central Europe to observations of the Global Network of Isotopes in Precipitation (GNIP) and to observations of isotope ratios of water vapor at different locations in Germany. We find a good agreement of modelled and observed isotope ratios in summer. In winter, we observe a systematic overestimation of modelled isotope ratios in precipitation and low-level water vapor. We relate those differences to specific circulation regimes with predominantly easterly moisture transport and the corresponding strong dependence of modelled isotope ratios on lateral boundary data. Furthermore, we investigate the dependence of modelled isotope ratios in winter on the type of isotope fractionation during surface evaporation at skin temperatures close to the freezing point.

  17. Stable isotopic composition of East African lake waters

    International Nuclear Information System (INIS)

    The investigation of stable isotopic composition of East African lake waters was conducted by scientists from the Department of Geology, University of Nairobi, as part of the International Decade for the East African Lakes (IDEAL) project and in close collaboration with the scientists from Large Lakes Observatory of the University of Minnesota and the Isotope Hydrology Laboratory of the IAEA in Vienna. The Research Contract was part of the IAEA Co-ordinated Research Programme on Isotope Techniques in Lake Dynamics Investigations, and was sponsored by the Agency. Water and grab sediment samples were obtained from East African Lakes during the month of January and February 1994 and July/August 1995. Water samples were analysed for oxygen and deuterium isotopic composition at the IAEA Laboratories in Vienna, Austria. In this final paper we report the results of the study of oxygen and deuterium isotopic composition from the East African lake waters. (author)

  18. Principles of stable isotope distribution

    CERN Document Server

    Criss, Robert E

    1999-01-01

    1. Abundance and Measurement of Stable Isotopes 1.1. Discovery of Isotopes 1.2. Nuclide Types, Abundances, and Atomic Weights 1.3. Properties and Fractionation of Isotopic Molecules 1.4. Material Balance Relationships 1.5. Mass Spectrometers 1.6. Notation and Standards 1.7. Summary 1.8. Problems References 2. Isotopic Exchange and Equilibrium Fractionation 2.1. Isotopic Exchange Reactions 2.2. Basic Equations 2.3. Molecular Models 2.4. Theory of Isotopic Fractionation 2.5. Temperature Dependence of Isotopic Fractionation Factors 2.6. Rule of the Mean 2.7. Isotopic Thermometers

  19. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  20. The BR2 materials testing reactor. Past, ongoing and under-study upgradings

    International Nuclear Information System (INIS)

    The BR2 reactor (Mol, Belgium) is a high-flux materials testing reactor. The fuel is 93% 235U enriched uranium. The nominal power ranges from 60 to 100 MW. The main features of the design are the following: 1) maximum neutron flux, thermal: 1.2 x 1015 n/cm2 s; fast (E > 0.1 MeV) : 8.4 x 1014 n /cm2 s; 2) great flexibility of utilization: the core configuration and operation mode can be adapted to the experimental loading; 3) neutron spectrum tailoring; 4) availability of five 200 mm diameter channels besides the standard channels (84 mm diameter); 5) access to the top and bottom covers of the reactor authorizing the irradiation of loops. The reactor is used to study the behaviour of fuel elements and structural materials intended for future nuclear power stations of several types (fission and fusion). Irradiations are carried out in connection with performance tests up to very high burn-up or neutron fluence as well as for safety experiments, power cycling experiments, and generally speaking, tests under off-normal conditions. Irradiations for nuclear transmutation (production of high specific activity radio-isotopes and transplutonium elements), neutron-radiography, use of beam tubes for physics studies, and gamma irradiations are also carried out. The BR2 is used in support of Belgian programs, at the request of utilities, industry and universities and in the framework of international agreements. The paper reviews the past and ongoing upgrading and enhancement of reactor capabilities as well as those under study or consideration, namely with regard to: reactor equipment, fuel elements, irradiation facilities, reactor operation conditions and long-term strategy. (author)

  1. Fundamental studies on kinetic isotope effect (KIE) of hydrogen isotope fractionation in natural gas systems

    Science.gov (United States)

    Ni, Y.; Ma, Q.; Ellis, G.S.; Dai, J.; Katz, B.; Zhang, S.; Tang, Y.

    2011-01-01

    Based on quantum chemistry calculations for normal octane homolytic cracking, a kinetic hydrogen isotope fractionation model for methane, ethane, and propane formation is proposed. The activation energy differences between D-substitute and non-substituted methane, ethane, and propane are 318.6, 281.7, and 280.2cal/mol, respectively. In order to determine the effect of the entropy contribution for hydrogen isotopic substitution, a transition state for ethane bond rupture was determined based on density function theory (DFT) calculations. The kinetic isotope effect (KIE) associated with bond rupture in D and H substituted ethane results in a frequency factor ratio of 1.07. Based on the proposed mathematical model of hydrogen isotope fractionation, one can potentially quantify natural gas thermal maturity from measured hydrogen isotope values. Calculated gas maturity values determined by the proposed mathematical model using ??D values in ethane from several basins in the world are in close agreement with similar predictions based on the ??13C composition of ethane. However, gas maturity values calculated from field data of methane and propane using both hydrogen and carbon kinetic isotopic models do not agree as closely. It is possible that ??D values in methane may be affected by microbial mixing and that propane values might be more susceptible to hydrogen exchange with water or to analytical errors. Although the model used in this study is quite preliminary, the results demonstrate that kinetic isotope fractionation effects in hydrogen may be useful in quantitative models of natural gas generation, and that ??D values in ethane might be more suitable for modeling than comparable values in methane and propane. ?? 2011 Elsevier Ltd.

  2. Closed Spaces in Cosmology

    CERN Document Server

    Fagundes, Helio V

    2008-01-01

    This paper deals with two aspects of relativistic cosmologies with closed (compact and boundless) spatial sections. These spacetimes are based on the theory of General Relativity, and admit a foliation into space sections, which are spacelike hypersurfaces satisfying the postulate of the closure of space: each is a 3-dimensional closed Riemannian manifold. The discussed topics are: (1) A comparison, previously obtained, between Thurston's geometries and Bianchi-Kantowski-Sachs metrics for such 3-manifolds is here clarified and developed. (2) Some implications of global inhomogeneity for locally homogeneous 3-spaces of constant curvature are analyzed from an observational viewpoint.

  3. The New Locality of Chenopodium Pumilio R. Br. in Poland

    OpenAIRE

    Witosławski, Piotr

    2010-01-01

    The clammy goosefoot Chenopodium pumilio R. Br. is a rare anthropophyte in the Polish flora. Hitherto, this species was recorded in Gdańsk and Rybnik. The present study describes the newly-discovered locality in Stryków near Łódź (Central Poland), the occurrence of this species in Poland and the general geographical distribution in the world.

  4. The new locality of Chetiopodium pumilio R. Br. in Poland

    OpenAIRE

    Witosławski, Piotr

    2009-01-01

    The clammy goosefoot Chenopodium pumilio R. Br. is a rare anthropophyte in the Polish flora. Hitherto, this species was recorded in Gdańsk and Rybnik. The present study describes the newly-discovered locality in Stryków near Łódź (Central Poland), the occurrence of this species in Poland and the general geographical distribution in the world.

  5. The stability of TlBr detectors at low temperature

    International Nuclear Information System (INIS)

    Thallium bromide (TlBr) is a promising semiconductor detector material due to its high atomic number (Tl: 81, Br: 35), high density (7.56 g/cm3) and wide band gap (2.68 eV). Current TlBr detectors suffer from polarization, which causes performance degradation over time when high voltage is applied. A 4.6-mm thick TlBr detector with pixellated anodes made by Radiation Monitoring Devices Inc. was used in the experiments. The detector has a planar cathode and nine anode pixels surrounded by a guard ring. The pixel pitch is 1.0-mm. Digital pulse waveforms of preamplifier outputs were recorded using a multi-channel GaGe PCI digitizer board for pulse shaping. Several experiments were carried out at -20 oC while the detector was under bias for over a month. No polarization effect was observed and the detector's spectroscopic performance improved over time. Energy resolution of 1.5% FWHM at 662 keV has been measured without depth correction at -2000 V cathode bias. Average electron mobility-lifetime of (5.7±0.8) x10-3 cm2/V has been measured from four anode pixels.

  6. Narva kant vajab oma brändi / Esko Passila

    Index Scriptorium Estoniae

    Passila, Esko

    2007-01-01

    Autor leiab, et Ida-Virumaa peaks looma ühtse tugeva brändi, mille alusel tulevikuotsuseid teha. See peaks tooma välja soodsa asukoha eelised, võimalused, tööjõu kättesaadavuse, kasutusvalmid maa-alad, hinnad jne.

  7. Analytical potential energy function for the Br + H2 system

    International Nuclear Information System (INIS)

    Analytical functions with a many-body expansion for the ground and first-excited-state potential energy surfaces for the Br+H2 system are newly presented in this work. These functions describe the abstraction and exchange reactions qualitatively well, although it has been found that the function for the ground-state potential surface is still quantitatively unsatisfactory. (author)

  8. Bellahøj. Ballerup. Brøndby Strand

    DEFF Research Database (Denmark)

    Bertelsen, S.

    det der skete? Hvem tog initiativet? Hvorfor lykkedes det med så stor succes, som det faktisk gjorde? Hvilke tanker, idealer og indgreb var udgangspunkt for den store indsats? På grundlag af disse spørgsmål har Sven Bertelsen i "Bellahøj - Ballerup - Brøndby Strand" skildret en væsentlig epoke i dansk...

  9. Cône Sud et Brésil

    OpenAIRE

    Droulers, Martine

    2005-01-01

    Synthèse mettant en perspective les rapides mutations actuelles et les anciens héritages de l'Amérique latine. Cet ouvrage distingue quatre ensembles territoriaux dont le Cône Sud et le Brésil (chapitre 4) qui forment l'entité la plus développée...

  10. Large BR(h -> tau mu) in Supersymmetric Models

    CERN Document Server

    Hammad, Ahmed; Un, Cem Salih

    2016-01-01

    We analyze the Lepton Flavor Violating (LFV) Higgs decay h -> tau mu in three supersymmetric models: Minimal Supersymmetric Standard Model (MSSM), Supersymmetric Seesaw Model (SSM), and Supersymmetric B-L model with Inverse Seesaw (BLSSM-IS). We show that in generic MSSM, with non-universal slepton masses and/or trilinear couplings, it is not possible to enhance BR(h -> tau mu) without violating the experimental bound on the BR(tau -> mu gamma). In SSM, where flavor mixing is radiatively generated, the LFV process mu -> e gamma strictly constrains the parameter space and the maximum value of BR(h -> tau mu) is of order 10^-10, which is extremely smaller than the recent results reported by the CMS and ATLAS experiments. In BLSSM-IS, with universal soft SUSY breaking terms at the grand unified scale, we emphasize that the measured values of BR(h -> tau mu) can be accommodated in a wide region of parameter space without violating LFV constraints. Thus, confirming the LFV Higgs decay results will be a clear signa...

  11. Pressure and temperature dependence kinetics study of the NO + BrO yielding NO2 + Br reaction - Implications for stratospheric bromine photochemistry

    Science.gov (United States)

    Watson, R. T.; Sander, S. P.; Yung, Y. L.

    1979-01-01

    The reactivity of NO with BrO radicals over a wide range of pressure (100-700 torr) and temperature (224-398 K) is investigated using the flash photolysis-ultraviolet absorption technique. The flash photolysis system consists of a high-pressure xenon arc light source, a reaction cell/gas filter/flash lamp combination, and a 216.5 half-meter monochromator/polychromator/spectrography for wavelength selectivity. The details of the reaction and its corresponding Arrhenius expression are identified. The results are compared with previous measurements, and atmospheric implications of the reaction are discussed. The NO + BrO yielding NO2 + Br reaction is shown to be important in controlling the concentration ratios of BrO/Br and BrO/HBr in the stratosphere, but this reaction does not affect the catalytic efficiency of BrOx in ozone destruction.

  12. Pd Close Coupled Catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhong Hua SHI; Mao Chu GONG; Yao Qiang CHEN

    2006-01-01

    A catalyst comprised novel high surface area alumina support was prepared to control emission of automobiles. The results showed that prepared catalyst could satisfy the requirements of a high performance close coupled catalyst for its good catalytic activity at low temperature and good stability at high temperature.

  13. On closed weak supplemented modules

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing-yi; SHI Mei-hua

    2006-01-01

    A module M is called closed weak supplemented if for any closed submodule N of M, there is a submodule K of M such that M=K+N and K(c)N<<M. Any direct summand of closed weak supplemented module is also closed weak supplemented.Any nonsingular image of closed weak supplemented module is closed weak supplemented. Nonsingular V-rings in which all nonsingular modules are closed weak supplemented are characterized in Section 4.

  14. Decommissioning of the BR3 reactor: status and perspectives

    International Nuclear Information System (INIS)

    The BR3 plant at Mol in Belgium built at the end of the fifties was the first PWR plant built outside the USA. The reactor had a small net power output (10 MWe) but comprised all the loops and features of a commercial PWR plant. The BR3 plant was operated with the main objective of testing advanced PWR fuels under irradiation conditions similar to those encountered in large commercial PWR plants. The reactor was started in 1962 and shut down in 1987 after 25 years of continuous operation. Since 1989, SCK.CEN is decommissioning the BR3 PWR research reactor. The dismantling of the metallic components including reactor pressure vessel and internals is completed and extensively reported in the literature. The dismantling of auxiliary components and the decontamination of parts of the infrastructure are now going on. The decommissioning progress is continuously monitored and costs and strategy are regularly reassessed. The first part of the paper describes the main results and lessons learned from the reassessment exercises performed in 1994, 1999, 2004 and 2007. Impacts of changes in legal framework on the decommissioning costs will be addressed. These changes concern e.g. licensing aspects, clearance levels, waste management... The middle part of the paper discusses the management of activated and/or contaminated concrete. The costing exercise performed in 1995 highlighted that the management of activated and contaminated concrete is the second main cost item after the dismantling of the reactor pressure vessel and internals. Different possible solutions were studied. These are evacuation as radioactive waste with or without supercompaction, recycling this 'radioactive' grout or concrete for conditioning of radioactive waste e.g. conditioning of metallic waste. The paper will give the results of the cost-benefit analysis made to select the solution retained. The last part of the paper will discuss the end goal of the decommissioning of the BR3. In the final

  15. Isotopic and chemical composition of waters and gases from the east coast accretionary prism, New Zealand

    International Nuclear Information System (INIS)

    Gases and saline waters discharges from springs and mud volcanoes along the east coast of the North Island of New Zealand provide a unique opportunity to study the evolution of fluids within an active accretionary prism. The waters show intermediate (5000 mg Cl/kg) to high (26,000 mg Cl/kg) salinities and are enriched in both deuterium (δ 2H from -20 to -2 per mille) and oxygen-18 (δ18O from +3 to 7 per mille) with respect to local groundwater. Cl/Br ratios are with 250±50 close to those of seawater (285), B/Cl ratios are higher than those of seawater (0.0003) and range from 0.003 to 0.03 at comparatively uniform Li/B ratios of 0.05 ± 0.03. Relative Na, K and Mg contents suggest close attainment of water-rock equilibrium at temperatures of 85 ± 25 deg. C. Gas geothermometers (CO2, CH4, Ar) indicate equilibration in the liquid phase at somewhat higher temperatures of 100 ± 20 deg. C. Ratios of 3He/4He in gases from the central sector reach values of 3.35 RA indicating the presence of about 40% of mantle He. Significant amounts of N2 appear to be added from other than atmospheric sources. Formation of the highest Cl water (26,000 mg Cl/kg) is explained in terms of the hydration of basalt of a subducted seamount to form chlorite or serpentine. The isotopic and chemical compositions of the waters in the subducting sediments are compatible with the assumption that they form the main source for the magmatic components of waters discharged from andesitic volcanoes and associated geothermal systems. (author). 37 refs, 9 figs, 3 tabs

  16. Atmospheric test of the J(BrONO2/kBrO+NO2 ratio: implications for total stratospheric Bry and bromine-mediated ozone loss

    Directory of Open Access Journals (Sweden)

    B. Werner

    2012-10-01

    Full Text Available We report on time-dependent O3, NO2 and BrO profile measurements taken in the stratosphere by limb observations of scattered skylight at high-latitudes during autumn circulation turn-over. The observations are complemented by simultaneous direct solar occultation measurements around sunset and sunrise performed aboard the same stratospheric balloon payload. Supporting radiative transfer and photochemical modelling indicates that, the measurements can be used to constrain the ratio J(BrONO2/kBrO+NO2, for which overall a 1.69 ± 0.04 larger ratio is found than indicated by the most recent JPL compilation (Sander et al., 2011. Sensitivity studies reveal the major reasons likely to be (1 a larger BrONO2 absorption cross-section σBrONO2, primarily for wavelengths larger than 300 nm, and (2 a smaller kBrO+NO2 at 220 K than given by Sander et al. (2011. Other factors, e.g. the actinic flux and quantum yield for the dissociation of BrONO2, can be ruled out. The observations also have consequences for total inorganic stratospheric bromine (Bry estimated from stratospheric BrO measurements at high NOx loadings, since the J(BrONO2/kBrO+NO2 ratio largely determines the stratospheric BrO/Bry ratio during daylight. Using the revised J(BrONO2/kBrO+NO2 ratio, total stratospheric Bry is likely to be 1.4 ppt smaller than previously estimated from BrO profile measurements at high NOx loadings. This brings estimates of total stratospheric bromine inferred from organic source gas measurements (i.e. CH3Br, the halons, CH2Br2, CHBr3, ... into closer agreement with estimates based on BrO observations (inorganic method. The consequences for stratospheric ozone due to the revised J(BrONO2/kBrO+NO2 ratio are small (maximum −0.8%, since at high NOx (for which most Bry assessments are made an overestimated Bry using the inorganic method would in return almost cancel out with the amount of reactive bromine calculated in the photochemical models.

  17. Decommissioning of a small reactor (BR3 reactor, Belgium)

    International Nuclear Information System (INIS)

    Since 1989, SCK-CEN has been dismantling its PWR reactor BR3 (Belgian Reactor No. 3). After gaining a great deal of experience in remote dismantling of highly radioactive components during the actual dismantling of the two sets of internals, the BR3 team completed the cutting of its reactor pressure vessel (RPV). During the feasibility phase of the RPV dismantling, a decision was made to cut it under water in the refuelling pool of the plant, after having removed it from its cavity. The RPV was cut into segments using a milling cutter and a bandsaw machine. These mechanical techniques have shown their ability for this kind of operations. Prior to the segmentation, the thermal insulation situated around the RPV was remotely removed and disposed of. The paper will describe all these operations. The BR3 decommissioning activities also include the dismantling of contaminated loops and equipment. After a careful sorting of the pieces, optimized management routes are selected in order to minimize the final amount of radioactive waste to be disposed of. Some development of different methods of decontamination were carried out: abrasive blasting (or sand blasting), chemical decontamination (Oxidizing-Reducing process using Cerium). The main goal of the decontamination program is to recycle most of the metallic materials either in the nuclear world or in the industrial world by reaching the respective recycling or clearance level. Overall the decommissioning of the BR3 reactor has shown the feasibility of performing such a project in a safe and economical way. Moreover, BR3 has developed methodologies and decontamination processes to economically reduce the amount of radwaste produced. (author)

  18. Synthesis of [6-36Cl]chlorouracil, [6-82Br]bromouracil and [6-123I]iodouracil

    International Nuclear Information System (INIS)

    Three C-6 radiohalogenated uracil derivatives were prepared by non-isotopic halogen exchange reactions for evaluation as diagnostic radiopharmaceuticals. [6-36Cl]chlorouracil (radiochemical yield 77%, specific activity 5.66 MBq mmol-1) was prepared via calcium [36Cl]chloride exchange on 6-iodouracil, [6-82Br]bromouracil (27%, 68.4 MBq mmol-1) was prepared via ammonium [82Br]bromide exchange on 6-iodouracil and [6-123I]iodouracil (55.4%, 5.41 GBq mmol-1) was prepared via sodium [123I]iodide exchange on 6-chlorouracil. The specific activities and radiochemical yields were dependent upon the halide-ion concentration. (author)

  19. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  20. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  1. Carbon isotope techniques

    International Nuclear Information System (INIS)

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The 11C, 12C, 13C, and 14C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations

  2. Canonical approach to the closed string non-commutativity

    Directory of Open Access Journals (Sweden)

    Davidović Ljubica

    2014-01-01

    Full Text Available We consider the propagation of the closed bosonic string in the weakly curved background. We show that the closed string non-commutativity is essentially connected to the T-duality and nontrivial background. From the T-duality transformation laws, connecting the canonical variables of the original and T-dual theory, we find the structure of the Poisson brackets in the T-dual space corresponding to the fundamental Poisson brackets in the original theory. We find that the commutative original theory is equivalent to the non-commutative T-dual theory, in which Poisson brackets close on winding and momenta numbers and the coefficients are proportional to the background fluxes. [Projekat Ministarstva nauke Republike Srbije, br. 171031

  3. Fully isotopic model of fragmentation

    International Nuclear Information System (INIS)

    A general model for the fragmentation of a two-component or bipartite system (e.g., protons and neutrons) is proposed and solved exactly. The extension of this model to any number of components is also shown to be exactly solvable. A connection between this model and the permutation group is discussed and used to obtain closed-form solutions. The notion of isotopic equivalence is defined in order to evaluate the equivalence of these models to earlier one-component models. All the one-component models considered in earlier papers are shown to be equivalent to a particular subclass of two-component models. A simplified model applicable to the case of nuclear fragmentation is introduced and analyzed. Modifications to this model to include effects such as pairing and Coulomb interactions are discussed

  4. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs.

  5. Stable isotope geochemistry: definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author).

  6. Nuclear Structure of N $\\simeq$ 56 Krypton Isotopes

    CERN Multimedia

    2002-01-01

    In view of the strong overlap in subject matter, the proposals IP-39 and 40 were considered together by the ISOLDE-Committee, and a combined investigation was suggested to be presented to the PSCC.\\\\ \\\\ First results on $\\beta$-decay properties of very neutron-rich Br isotopes (Z=35) indicate a rather smooth onset of deformation already below N=60 and the existence of a deformed N=56 subshell gap. This behaviour is in contrast to earlier observations of a sudden onset of strong deformations at N=60 for $ \\% Z ge $ 37 nuclei. \\\\ \\\\ We propose to study at CERN-ISOLDE nuclear structure properties of N=55 - 57 Kr isotopes from $\\beta$-decay of $^9

  7. Unwrapping Closed Timelike Curves

    CERN Document Server

    Slobodov, Sergei

    2008-01-01

    Closed timelike curves (CTCs) appear in many solutions of the Einstein equation, even with reasonable matter sources. These solutions appear to violate causality and so are considered problematic. Since CTCs reflect the global properties of a spacetime, one can attempt to change its topology, without changing its geometry, in such a way that the former CTCs are no longer closed in the new spacetime. This procedure is informally known as unwrapping. However, changes in global identifications tend to lead to local effects, and unwrapping is no exception, as it introduces a special kind of singularity, called quasi-regular. This "unwrapping" singularity is similar to the string singularities. We give two examples of unwrapping of essentially 2+1 dimensional spacetimes with CTCs, the Gott spacetime and the Godel universe. We show that the unwrapped Gott spacetime, while singular, is at least devoid of CTCs. In contrast, the unwrapped Godel spacetime still contains CTCs through every point. A "multiple unwrapping"...

  8. Identification of Yellow Pigmentation Genes in Brassica rapa ssp. pekinensis Using Br300 Microarray

    Directory of Open Access Journals (Sweden)

    Hee-Jeong Jung

    2014-01-01

    Full Text Available The yellow color of inner leaves in Chinese cabbage depends on its lutein and carotene content. To identify responsible genes for yellow pigmentation in leaves, the transcriptome profiles of white (Kenshin and yellow leaves (Wheessen were examined using the Br300K oligomeric chip in Chinese cabbage. In yellow leaves, genes involved in carotene synthesis (BrPSY, BrPDS, BrCRTISO, and BrLCYE, lutein, and zeaxanthin synthesis (BrCYP97A3 and BrHYDB were upregulated, while those associated with carotene degradation (BrNCED3, BrNCED4, and BrNCED6 were downregulated. These expression patterns might support that the content of both lutein and total carotenoid was much higher in the yellow leaves than that in the white leaves. These results indicate that the yellow leaves accumulate high levels of both lutein and β-carotene due to stimulation of synthesis and that the degradation rate is inhibited. A large number of responsible genes as novel genes were specifically expressed in yellow inner leaves, suggesting the possible involvement in pigment synthesis. Finally, we identified three transcription factors (BrA20/AN1-like, BrBIM1, and BrZFP8 that are specifically expressed and confirmed their relatedness in carotenoid synthesis from Arabidopsis plants.

  9. Nonrelativistic closed string theory

    OpenAIRE

    Gomis, Jaume; Ooguri, Hirosi

    2001-01-01

    We construct a Galilean invariant nongravitational closed string theory whose excitations satisfy a nonrelativistic dispersion relation. This theory can be obtained by taking a consistent low energy limit of any of the conventional string theories, including the heterotic string. We give a finite first order worldsheet Hamiltonian for this theory and show that this string theory has a sensible perturbative expansion, interesting high energy behavior of scattering amplitudes and a Hagedorn tra...

  10. Simultaneous balloon-borne measurements of the key inorganic bromine species BrO and BrONO2 in the stratosphere: DOAS and MIPAS-B evaluation

    Science.gov (United States)

    Kazarski, Sebastian; Maucher, Guido; Ebersoldt, Andreas; Butz, André; Friedl-Vallon, Felix; Höpfner, Michael; Kleinert, Anne; Nordmeyer, Hans; Oelhaf, Hermann; Pfeilsticker, Klaus; Sinnhuber, Björn-Martin; Wetzel, Gerald; Orphal, Johannes

    2015-04-01

    Inorganic bromine contributes to a loss of stratospheric ozone of about 25 - 30%. Past studies have demonstrated several uncertainties in the photochemistry of stratospheric bromine, especially by considering the three body reaction (kBrONO2) BrO + NO2 + M → BrONO2 + M, and the photolysis frequencies of BrONO2 (jBrONO2). Hence, an improved knowledge of the ratio jBrONO2/kBrONO2 is crucial to better assess the bromine-related loss of ozone as well as the total amount of bromine in the stratosphere. Here, we report on the first simultaneous balloon-borne measurements of NO2, BrO, and BrONO2 in the stratosphere, performed over Timmins (Ontario, 49 °N, Canada) on Sept., 7th and 8th, 2014. During the flight the targeted species were monitored by remote sensing in the UV, visible and mid-IR spectral ranges by Differential Optical Absorption Spectroscopy (DOAS) and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B), respectively. The analysis and interpretation of the measurements involves radiative transfer as well as photochemical modelling. Major features of the applied techniques are reported and first results of the DOAS as well as MIPAS-B evaluation are discussed. Further investigations address inter-comparisons of the retrieved NO2, BrO, and O3 concentrations and volume mixing ratios, to demonstrate validations of both evaluation methods.

  11. Simulated oxygen isotopes in cave drip water and speleothem calcite in European caves

    Directory of Open Access Journals (Sweden)

    A. Wackerbarth

    2012-11-01

    Full Text Available Interpreting stable oxygen isotope18O records from stalagmites is still one of the complex tasks in speleothem research. Here, we present a novel model-based approach, where we force a model describing the processes and modifications of δ18O from rain water to speleothem calcite (Oxygen isotope Drip water and Stalagmite Model – ODSM with the results of a state-of-the-art atmospheric general circulation model enhanced by explicit isotope diagnostics (ECHAM5-wiso. The approach is neither climate nor cave-specific and allows an integrated assessment of the influence of different varying climate variables, e.g. temperature and precipitation amount, on the isotopic composition of drip water and speleothem calcite. <br>> First, we apply and evaluate this new approach under present-day climate conditions using observational data from seven caves from different geographical regions in Europe. Each of these caves provides measured δ18O values of drip water and speleothem calcite to which we compare our simulated isotope values. For six of the seven caves modeled δ18O values of drip water and speleothem calcite are in good agreement with observed values. The mismatch of the remaining caves might be caused by the complexity of the cave system, beyond the parameterizations included in our cave model. <br>> We then examine the response of the cave system to mid-Holocene (6000 yr before present, 6 ka climate conditions by forcing the ODSM with ECHAM5-wiso results from 6 ka simulations. For a set of twelve European caves, we compare the modeled mid-Holocene-to-modern difference in speleothem calcite δ18O to available measurements. We show that the general European changes are simulated well. However, local discrepancies are found, and might be explained either by a too low model resolution, complex local soil-atmosphere interactions affecting evapotranspiration or by cave specific factors

  12. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  13. Method for isotope separation

    International Nuclear Information System (INIS)

    The inventor proposes a method for separating isotopes from gaseous compounds by selective excitation by means of laser beams for such cases where the reaction partners each consist of several isotopes. For example, separation of 235U and 238U in the form of UCl6 is mentioned with 35Cl and 37Cl existing in the natural composition of 76:24. According to the invention, after isolating the reaction product obtained in a way already known, the remaining fraction of the compound mixture is brought together with the reaction partner present in the natural isotope composition, in a heated flow path. Thereby by isotope exchange of the latter regeneration will take place, and the mixture can pass again through the separation plant in initial composition. (orig./PW)

  14. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  15. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  16. Material test reactor fuel research at the BR2 reactor

    International Nuclear Information System (INIS)

    The construction of new, high performance material test reactor or the conversion of such reactors' core from high enriched uranium (HEU) to low enriched uranium (LEU) based fuel requires several fuel qualification steps. For the conversion of high performance reactors, high density dispersion or monolithic fuel types are being developed. The Uranium-Molybdenum fuel system has been selected as reference system for the qualification of LEU fuels. For reactors with lower performance characteristics, or as medium enriched fuel for high performance reactors, uranium silicide dispersion fuel is applied. However, on the longer term, the U-Mo based fuel types may offer a more efficient fuel alternative and-or an easier back-end solution with respect to the silicide based fuels. At the BR2 reactor of the Belgian nuclear research center, SCK-CEN in Mol, several types of fuel testing opportunities are present to contribute to such qualification process. A generic validation test for a selected fuel system is the irradiation of flat plates with representative dimensions for a fuel element. By flexible positioning and core loading, bounding irradiation conditions for fuel elements can be performed in a standard device in the BR2. For fuel element designs with curved plates, the element fabrication method compatibility of the fuel type can be addressed by incorporating a set of prototype fuel plates in a mixed driver fuel element of the BR2 reactor. These generic types of tests are performed directly in the primary coolant flow conditions of the BR2 reactor. The experiment control and interpretation is supported by detailed neutronic and thermal-hydraulic modeling of the experiments. Finally, the BR2 reactor offers the flexibility for irradiation of full size prototype fuel elements, as 200mm diameter irradiation channels are available. These channels allow the accommodation of various types of prototype fuel elements, eventually using a dedicated cooling loop to provide the

  17. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  18. Canada's medical isotope strategy

    International Nuclear Information System (INIS)

    This paper details Canada's medical isotope strategy and the role of the Canadian Government in the security of the isotope supply chain. The government's role is to promote health and safety of Canadians, establish appropriate regulatory framework, allow the markets to work, facilitate international collaboration, fund high-risk early stage research and development, encourage private sector investment in innovation and support and respect environmental and non-proliferation goals.

  19. Separating isotopes by laser

    International Nuclear Information System (INIS)

    Isotope separation by laser radiation is proving a very promising method for obtaining large scale isotope production at low cost and is particularly relevant to the enrichment of 235U for the nuclear power industry. Various methods for laser separation, differing mainly in the way the selectively excited atoms or molecules are extracted, are discussed. The efficiency of the various methods, which is the controlling factor in determining their practical viability and some of the problems encountered are examined. (UK)

  20. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  1. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  2. Isotope heated thermal batteries

    International Nuclear Information System (INIS)

    A deferred action thermal battery is described that includes a quantity of radioactive isotope normally positioned so that only a small part of the thermal energy generated by the isotope is received by the battery, but adapted, when the battery is rendered active, to be moved automatically to a position where a large part of the thermal energy is received. The battery may comprise a chamber containing its cells and a second chamber part of which is remote from the cells for normal storage of the isotope and part of which is adjacent to the cells; the isotope is moved to the latter part when the battery is activated. The cell chamber is preferably toroidal and surrounds the second portion of the isotope chamber. The isotope may be contained in a carriage held by a retaining means adapted for release when the battery is activated, resilient means then moving the carriage to the active position. The retaining means may be a wire that disintegrates on the passage of electric current, the current also igniting a combustible composition to activate the battery. The object is to provide thermal batteries having an extended life. (U.K.)

  3. High-resolution infrared spectroscopy of CH281BrF near 8 μm: rovibrational analysis of the ν3 and ν8 fundamentals and resonances with the dark states 2ν5 and ν6 + ν9

    DEFF Research Database (Denmark)

    Stroppa, P.; Tasinato, N.; Baldacci, A.;

    2014-01-01

    The infrared spectrum of isotopically enriched CH2 81BrF was investigated in the ν3 and ν8 region between 1150 and 1370 cm−1 at a resolution of 0.003 cm−1. The ν3 vibration of symmetry species A gives rise to an a-/b-hybrid band with a-type predominance, while the ν8 mode of A symmetry produces c...

  4. The isotopic distribution conundrum.

    Science.gov (United States)

    Valkenborg, Dirk; Mertens, Inge; Lemière, Filip; Witters, Erwin; Burzykowski, Tomasz

    2012-01-01

    Although access to high-resolution mass spectrometry (MS), especially in the field of biomolecular MS, is becoming readily available due to recent advances in MS technology, the accompanied information on isotopic distribution in high-resolution spectra is not used at its full potential, mainly because of lack of knowledge and/or awareness. In this review, we give an insight into the practical problems related to calculating the isotopic distribution for large biomolecules, and present an overview of methods for the calculation of the isotopic distribution. We discuss the key events that triggered the development of various algorithms and explain the rationale of how and why the various isotopic-distribution calculations were performed. The review is focused around the developmental stages as briefly outlined below, starting with the first observation of an isotopic distribution. The observations of Beynon in the field of organic MS that chlorine appeared in a mass spectrum as two variants with odds 3:1 lie at the basis of the first wave of algorithms for the calculation of the isotopic distribution, based on the atomic composition of a molecule. From here on, we explain why more complex biomolecules such as peptides exhibit a highly complex isotope pattern when assayed by MS, and we discuss how combinatorial difficulties complicate the calculation of the isotopic distribution on computers. For this purpose, we highlight three methods, which were introduced in the 1980s. These are the stepwise procedure introduced by Kubinyi, the polynomial expansion from Brownawell and Fillippo, and the multinomial expansion from Yergey. The next development was instigated by Rockwood, who suggested to decompose the isotopic distribution in terms of their nucleon count instead of the exact mass. In this respect, we could claim that the term "aggregated" isotopic distribution is more appropriate. Due to the simplification of the isotopic distribution to its aggregated counterpart

  5. Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    S. Moukhtar

    2011-11-01

    Full Text Available A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter is presented. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. Particulate matter was collected on quartz fibre filters using dichotomous high volume air samplers. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography and solid phase extraction. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyltrifluoroacetamide, was added for Gas Chromatography-Mass Spectrometry analysis. The second half of the sample was stored in a refrigerator. For samples with concentrations exceeding 1 ng μl−1, the second half of the sample was used for measurement of stable carbon isotope ratios by Gas Chromatography-Isotope Ratio Mass Spectrometry. <br>> The procedure described in this paper provides a method for the analysis of methylnitrophenols in atmospheric particulate matter at concentrations as low as 0.3 pg m−3 and for stable isotope ratios with an accuracy of better than ±0.5‰ for concentrations exceeding 100 pg m−3. <br>> In all atmospheric particulate matter samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol, with concentrations ranging from the low pg m−3 range in rural areas to more than 200 pg m−3 in some samples from a suburban location.

  6. Stable carbon isotope reconstruction of ungulate diet changes through the seasonal cycle

    OpenAIRE

    Codron, D.; Lee-Thorp, J A; M. Sponheimer; J. Codron

    2007-01-01

    We analysed stable carbon isotope ratios (13C) in faeces of 11 African ungulate species from three South African savanna environments to determine whether this approach is sufficiently sensitive to record short-term seasonal diet changes in browsers (BR), mixed-feeders (IM), and grazers (GR). At monthly intervals, faecal 13C revealed variations in proportions of C3 (browse) to C4 (grass) biomass consumed that were not detected by broader dry versus wet season comparisons, including subtle die...

  7. Electron nuclear double resonance study of photostimulated luminescence active centers in CsBr:Eu2+ medical imaging plates

    International Nuclear Information System (INIS)

    CsBr:Eu2+ needle image plates exhibit an electron-paramagnetic-resonance (EPR) spectrum at room temperature (RT), whose intensity is correlated with the photostimulated luminescence sensitivity of the plate. This EPR spectrum shows a strong temperature dependence: At RT it is owing to a single Eu2+ (S =7/2) center with axial symmetry, whereas at T1H nuclei close to the central Eu2+ ions in the centers. Analysis of the angular dependence of the ENDOR spectra allows to propose models for these centers, providing an explanation for the observed difference in intensity between the spectral components and for their temperature dependence.

  8. Structural studies of the polysaccharides from the lipopolysaccharides of Azospirillum brasilense Sp246 and SpBr14.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Grinev, Vyacheslav S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2014-10-29

    Lipopolysaccharides from closely related Azospirillum brasilense strains, Sp246 and SpBr14, were obtained by phenol-water extraction. Mild acid hydrolysis of the lipopolysaccharides followed by GPC on Sephadex G-50 resulted in polysaccharide mixtures. On the basis of sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy data, it was concluded that both bacteria possess the same two distinct polysaccharides having structures 1 and 2: [structure: see text]. Structure 1 has been reported earlier for a polysaccharide of A. brasilense 54 [Fedonenko et al., 2011] whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. PMID:25240180

  9. A calender of high multiplicity 16O induced reactions in Ag(Br) at 200A MeV

    International Nuclear Information System (INIS)

    This calendar contains information about all charged particles in 50 high multiplicity 16O + 107Ag or 80Br events in nuclear emulsions between 200A MeV and 220A MeV. A stack of 26 Ilford G5 pellicles, each 10*10*0.06 cm3, has been exposed horizontally to the 250A MeV 16O beam from the Berkeley Bevalac with a flux of 5*104 ions/cm2. All charged particles with a range >= 5 μm are registered and indentified by conventional methods. Except for Z=1 particles, no mass determination could be performed experimentally and the adopted mass values are otherwise those of the most stable isotopes. The tables could be used to: Estimation of source velocity. Correlation studies of various kind - angles, phase space etc. Flow tensor calculations. (author) (50 tables, 50 figures)

  10. Pyridine•BrF3, the missing link for clean fluorinations of aromatic derivatives.

    Science.gov (United States)

    Hagooly, Youlia; Rozen, Shlomo

    2012-02-17

    This work demonstrates the unique features of the never used before Py•BrF(3) complex in the field of aromatic organic fluorinations. The main disadvantage of the noncomplexed BrF(3) is the fact that usually, in addition to the desired fluorination, a parallel electrophilic aromatic bromination takes place as well. Use of the Py•BrF(3) complex reduces this electrophilic bromination, which is observed with most reagents based on fluorine and bromine [BrF]. PMID:22313187

  11. Les guides et inventaires patrimoniaux au Brésil

    OpenAIRE

    Kühl, Beatriz Mugayar

    2014-01-01

    La production des guides du patrimoine au Brésil, caractérisée par son extrême hétérogénéité, s’appuie dans la plupart des cas sur des listes de biens classés ou sur des inventaires qui ne garantissent pas la protection légale des édifices et qui sont souvent limités à de brèves descriptions sans ou avec peu d’analyses. Alors que des récits plus anciens de voyageurs présentaient des descriptions de villes, d’édifices et de paysages, tout en apportant un regard critique extérieur sur la réalit...

  12. Closed strings from nothing

    OpenAIRE

    Kleban, Matthew; Lawrence, Albion; Shenker, Stephen

    2000-01-01

    We study the physics of open strings in bosonic and type II string theories in the presence of unstable D-branes. When the potential energy of the open string tachyon is at its minimum, Sen has argued that only closed strings remain in the perturbative spectrum. We explore the scenario of Yi and of Bergman, Hori and Yi, who argue that the open string degrees of freedom are strongly coupled and disappear through confinement. We discuss arguments using open string field theory and worldsheet bo...

  13. Closed Circuit Videoinstallationen

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    and 650 artists. This and the notes on further reading and viewing will enable deeper explorations of the material in a way not unlike the open “hyper-text”- structure. Video technique makes it possible to simultaneously record and reproduce images, sound and sequences of motion; that potential can...... and at the same time general investigations. The research project, ‘Closed-Circuit-Video Installations. A Study on the History and Theory of Media Art’, is being supported by the Fritz-Thyssen Foundation, Cologne....

  14. Refurbishment of BR2 (Phases 4 and 5)

    International Nuclear Information System (INIS)

    The BR2 is a materials testing reactor and is SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In phase 4 of the refurbishment programme, various activities were performed to allow reactor start-up. In phase 5, remaining refurbishment works were carried out as well as the extra studies and upgradings required by the licensing authorities. Major achievements in 1997 are described and discussed

  15. Status report on developing I-124, Pd-103, Tc-94m, Br-76 and Cu-64 radioisotopes at KIRAMS

    International Nuclear Information System (INIS)

    The decay characteristics of their radioisotopes such as I-124, Pd-103, Tc-94m, Br-76 and Cu-64 radionuclides produced by cyclotron have considered useful agents for diagnostic imaging or therapy. In order to increase the availability of the radionuclides, the investigation for the high capacity target design and simple procedures yielding high activities is being carried. Therefore, KIRAMS will lead researchers in nuclear medicine to access the feasibility of reliable production for enough quantities of several research radioisotopes using (p,xn) reactions. The quality and yield of products are evaluated theoretically from the excitation functions as a function of proton energies, target thickness, bombarding time, and growth time. Radionuclidic impurities are determined by gamma-spectrometer with high purity Germanium (HPGe) detector and the yields are read by ion chamber. Multi-millicuries of radioisotope I-124 (23% positron emission, half-life 4.2 days) is produced by 125-TeO2(p,2n)124-I reaction at the incident proton energy of 22 MeV. The production of carrier-free Pd-103 by the 103Rh(p,n)103Pd reaction with the 18 MeV proton beam. The electroplating method of Rh to Cu plate and recovery of rhodium from irradiated target fragments will be discussed. The thermal stability of Rh films on Cu plate will be tested for the mass production by increasing beam current up to 220uA with high-current cyclotron. For Cu-64, Tc-94m and Br-76 radionuclides, the target preparation and separating techniques are under developing. Our research project emphasis is in the development of routine methods for the production of Pd-103 radionuclide for brachytherapy seed and PET radionuclides, which include I-124, Tc-94m, Br-76 and Cu-64. In addition to the production of these radionuclides, we are developing novel radiopharmaceuticals utilizing these isotopes for both imaging and therapy

  16. Production of neutron-rich isotopes in transfer-type reactions

    International Nuclear Information System (INIS)

    The production yields of new neutron-rich 84,86Zn and 90,92Ge isotopes beyond N=50 and isotopes of nuclei with charge numbers Z=64-80 are estimated for future experiments in the multinucleon transfer reactions at energies close to the Coulomb barrier. (author)

  17. Molecular laser isotope separation programme at BARC

    International Nuclear Information System (INIS)

    Little over thirty years ago, BARC ventured into a new frontier of scientific research: Molecular Laser Isotope Separation (MLIS) programme based on the interaction of lasers with molecules. The initial project was a scheme to produce enriched uranium. The idea was to use the intense, monochromatic light of lasers to break the chemical bonds of only those molecules containing the fissionable isotope uranium-235. At present the programme is evolving around separation of low and middle mass isotopes, namely sulphur 34/33/32, oxygen 17/18, carbon 13/12, hydrogen T/D/H to be followed by an advanced engineering programme designed to lead to a demonstration plant. The latest results have come very close to the design parameters specified for a full-scale separation of carbon isotopes. All these expertise provide an infra structure for future front line R and D activities in the general area of Laser Photochemical Technology which would include i) LIS of other useful elements ii) Material processing and iii) Fuel reprocessing/ waste management (author)

  18. ZnWO4 nanorods decorated with Ag/AgBr nanoparticles as highly efficient visible-light-responsive photocatalyst for dye AR18 photodegradation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Ag/AgBr-sensitized ZnWO4 nanorod heterojunction was fabricated and characterized. • The composite showed the enhanced visible-light activity for AR18 photodegradation. • The enhancement mechanism and the catalytic degradation mechanism were revealed. • The effects of various parameters on AR18 photodegradation kinetics were examined. - Abstract: A novel Ag-AgBr/ZnWO4 nanorod heterostructure composite was prepared via a facile deposition–precipitation method with ZnWO4 nanorods as the substrate, and characterized by XRD, SEM-EDX, TEM, XPS, and DRS to confirm its structure, morphology, composition, and optical property. The composite was used as a photocatalyst to destroy azo dye Acid Red 18 (AR18) under visible light irradiation. The effects of catalyst composition, solution pH, catalyst loading, and initial dye concentration on photocatalytic degradation rate and efficiency were examined. It was revealed that the photocatalytic activity of Ag-AgBr/ZnWO4 nanojunction system was higher than that of the single ZnWO4 or Ag-AgBr for AR18 degradation under visible light irradiation. The optimal content of Ag-AgBr in Ag-AgBr/ZnWO4 composite was 0.58:1 of Ag/W molar ratio using in the catalyst preparation. Acid pH and decreasing dye initial concentration were favorable to AR18 photodegradation, but the catalyst loading had an optimal value. The catalyst was stable and recyclable, after five successive cycles the photoactivity was fully maintained and the XRD patterns of AgBr displayed no evident change. Photoluminescence spectra revealed the enhanced photocatalytic activity and stability were closely related to the efficient separation of photogenerated carriers in Ag-AgBr/ZnWO4 nanojunction system. Superoxide radicals and holes were found to be main active species for AR18 photodegradation. Finally, the possible mechanism for AR18 degradation over Ag-AgBr/ZnWO4 nanorods under visible light irradiation was proposed as well

  19. ZnWO{sub 4} nanorods decorated with Ag/AgBr nanoparticles as highly efficient visible-light-responsive photocatalyst for dye AR18 photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kebin, E-mail: kebinlee314@gmail.com [College of Chemistry and Material Science, Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, Northwest University, Xi’an 710069 (China); Xue, Jie; Zhang, Yanhui [College of Chemistry and Material Science, Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, Northwest University, Xi’an 710069 (China); Wei, Hong [Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi’an University of Technology, Xi’an 710048 (China); Liu, Yalan; Dong, Chengxing [College of Chemistry and Material Science, Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, Northwest University, Xi’an 710069 (China)

    2014-11-30

    Graphical abstract: - Highlights: • Ag/AgBr-sensitized ZnWO{sub 4} nanorod heterojunction was fabricated and characterized. • The composite showed the enhanced visible-light activity for AR18 photodegradation. • The enhancement mechanism and the catalytic degradation mechanism were revealed. • The effects of various parameters on AR18 photodegradation kinetics were examined. - Abstract: A novel Ag-AgBr/ZnWO{sub 4} nanorod heterostructure composite was prepared via a facile deposition–precipitation method with ZnWO{sub 4} nanorods as the substrate, and characterized by XRD, SEM-EDX, TEM, XPS, and DRS to confirm its structure, morphology, composition, and optical property. The composite was used as a photocatalyst to destroy azo dye Acid Red 18 (AR18) under visible light irradiation. The effects of catalyst composition, solution pH, catalyst loading, and initial dye concentration on photocatalytic degradation rate and efficiency were examined. It was revealed that the photocatalytic activity of Ag-AgBr/ZnWO{sub 4} nanojunction system was higher than that of the single ZnWO{sub 4} or Ag-AgBr for AR18 degradation under visible light irradiation. The optimal content of Ag-AgBr in Ag-AgBr/ZnWO{sub 4} composite was 0.58:1 of Ag/W molar ratio using in the catalyst preparation. Acid pH and decreasing dye initial concentration were favorable to AR18 photodegradation, but the catalyst loading had an optimal value. The catalyst was stable and recyclable, after five successive cycles the photoactivity was fully maintained and the XRD patterns of AgBr displayed no evident change. Photoluminescence spectra revealed the enhanced photocatalytic activity and stability were closely related to the efficient separation of photogenerated carriers in Ag-AgBr/ZnWO{sub 4} nanojunction system. Superoxide radicals and holes were found to be main active species for AR18 photodegradation. Finally, the possible mechanism for AR18 degradation over Ag-AgBr/ZnWO{sub 4} nanorods under

  20. Optimized Control Rods of the BR2 Reactor

    International Nuclear Information System (INIS)

    At the present time the BR-2 reactor uses control elements with cadmium as neutron absorbing part. The lower section of the control element is a beryllium assembly cooled by light water. Due to the burn up of the lower end of the cadmium section during the reactor operation, the presently used rods for reactivity control of the BR-2 reactor have to be replaced by new ones. Considered are various types Control Rods with full active part of the following materials: cadmium (Cd), hafnium (Hf), europium oxide (Eu2O3) and gadolinium (Gd2O3). Options to decrease the burn up of the control rod material in the hot spot, such as use of stainless steel in the lower active part of the Control Rod are discussed. Comparison with the characteristics of the presently used Control Rods types is performed. The changing of the characteristics of different types Control Rods and the perturbation effects on the reactor neutronics during the BR-2 fuel cycle are investigated. The burn up of the Control Rod absorbing material, total and differential control rods worth, macroscopic and effective microscopic absorption cross sections, fuel and reactivity evolution are evaluated during approximately 30 operating cycles.

  1. Bréal, un antinaturalisme d’inspiration humboldtienne

    Directory of Open Access Journals (Sweden)

    Babu Jean-Philippe

    2014-07-01

    Full Text Available Dans De la forme et de la fonction des mots, Bréal formulait, dès 1866, outre une critique générale du formalisme de la philologie comparative depuis Bopp, une thèse radicalement opposée à l’orientation naturaliste de l’évolutionnisme linguistique de Schleicher. Cette thèse, que nous prendrons le risque de définir comme thèse du primat de la fonction sur la forme linguistique, est au coeur de ce programme de linguistique générale pour lequel Bréal allait forger, quelques années plus tard, le mot de sémantique. Fortement marqué par la notion humboldtienne d’innere Sprachform, Bréal, contrairement à Saussure, n'abandonnera jamais le changement linguistique au hasard de l'histoire et maintiendra l'intelligence comme premier moteur des langues, quitte à poser la nécessité de repenser cette intelligence.

  2. Irradiation of Fuel Elements in the Belgian BR3 Reactor

    International Nuclear Information System (INIS)

    Under a contract concluded by EURATOM and CEN-BelgoNucléaire, fuel rods containing plutonium-enriched uranium were irradiated in the Belgian BR3 reactor with the object of evaluating the behaviour of plutonium fuel elements in power reactors. The first experiment consisted in introducing 12 fuel elements fabricated by vibration and compacting followed by swaging into a core assembly of the BR3 pressurized-water power reactor. Irradiation was carried out for a period corresponding to 4820 h at full power. Subsequent examination of the fuel rods showed that they had been unaffected by irradiation. A second series of experiments is being carried out in collaboration with the United Kingdom Atomic Energy Authority. These experiments involve irradiating an assembly of 37 plutonium-enriched fuel elements, some compacted and others of the pellet type, in the BR3/VN power reactor. The fabrication of the vibrocompacted elements and the thermal studies relating to the assembly are briefly described. (author)

  3. Optimized Control Rods of the BR2 Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kalcheva, Silva; Koonen, E.

    2007-09-15

    At the present time the BR-2 reactor uses control elements with cadmium as neutron absorbing part. The lower section of the control element is a beryllium assembly cooled by light water. Due to the burn up of the lower end of the cadmium section during the reactor operation, the presently used rods for reactivity control of the BR-2 reactor have to be replaced by new ones. Considered are various types Control Rods with full active part of the following materials: cadmium (Cd), hafnium (Hf), europium oxide (Eu2O3) and gadolinium (Gd2O3). Options to decrease the burn up of the control rod material in the hot spot, such as use of stainless steel in the lower active part of the Control Rod are discussed. Comparison with the characteristics of the presently used Control Rods types is performed. The changing of the characteristics of different types Control Rods and the perturbation effects on the reactor neutronics during the BR-2 fuel cycle are investigated. The burn up of the Control Rod absorbing material, total and differential control rods worth, macroscopic and effective microscopic absorption cross sections, fuel and reactivity evolution are evaluated during approximately 30 operating cycles.

  4. Closed strings from nothing

    International Nuclear Information System (INIS)

    We study the physics of open strings in bosonic and type-II string theories in the presence of unstable D-branes. When the potential energy of the open string tachyon is at its minimum, Sen has argued that only closed strings remain in the perturbative spectrum. We explore the scenario of Yi and of Bergman, Hori, and Yi, who argue that the open string degrees of freedom are strongly coupled and disappear through confinement. We discuss arguments using open string field theory and world sheet boundary renormalization group flows, which seem to indicate otherwise. We then describe a solitonic excitation of the open string tachyon and gauge field with the charge and tension of a fundamental closed string. This requires a double scaling limit where the tachyon is taken to its minimal value and the electric field is taken to its maximum value. The resulting flux tube has an unconstrained spatial profile; and for large fundamental string charge it appears to have light, weakly coupled open strings existing in the core. We argue that the flux tube acquires a size of order α' through sigma model and string coupling effects, and that confinement effects make the light degrees of freedom heavy and strongly interacting

  5. Closed Strings From Nothing

    International Nuclear Information System (INIS)

    We study the physics of open strings in bosonic and type II string theories in the presence of unstable D-branes. When the potential energy of the open string tachyon is at its minimum, Sen has argued that only closed strings remain in the perturbative spectrum. We explore the scenario of Yi and of Bergman, Hori and Yi, who argue that the open string degrees of freedom are strongly coupled and disappear through confinement. We discuss arguments using open string field theory and worldsheet boundary RG flows, which seem to indicate otherwise. We then describe a solitonic excitation of the open string tachyon and gauge field with the charge and tension of a fundamental closed string. This requires a double scaling limit where the tachyon is taken to its minimal value and the electric field is taken to its maximum value. The resulting flux tube has an unconstrained spatial profile; and for large fundamental string charge, it appears to have light, weakly coupled open strings living in the core. We argue that the flux tube acquires a size or order α' through sigma model and string coupling effects; and we argue that confinement effects make the light degrees of freedom heavy and strongly interacting

  6. Optimization of the Time Response of LaBr3(Ce) Detectors, and Its Dependence on Ce Concentration

    Science.gov (United States)

    Vedia, V.; Mach, H.; Fraile, L. M.; Lalkovski, S.; Udías, J. M.

    Fast inorganic scintillators that exhibit good spectroscopy performance, like LaBr3(Ce), are the crystals of choice for many applications; they play a crucial role in the Ultra Fast Timing technique by virtue of their good energy resolution and fast response [1]. This method, which is very sensitive to the LaBr3(Ce) time resolution, allows measurements of nuclear level lifetimes down to few ps range. There are indications that the nominal Ce concentration does strongly influence on the timing properties as well as it varies the photon yield and the energy resolution [2]. In this work we have searched for the best settings in order to optimize the time resolution of three cylindrical LaBr3(Ce) detectors equipped with crystals identical in volume and shape but with different Ce dopant concentration. The time resolution of every detector depends on the proper selection of the fast photomultiplier tube and the set up parameters that can be further optimized by fine-tuning of the Constant Fraction Discrimination (CFD) and the PMT bias voltage. Very good time resolution can be obtained with the ORTEC 935 CFD for very short time-delays. Timing properties of the three crystals were studied by delayed coincidence measurements against a reference BaF2 detector, whose time response is well known. The LaBr3(Ce) detector and the reference unit were placed in a close geometry with the radioactive source in between. We report timing results measured at the 60Co and 22Na energies.

  7. Diet-consumer nitrogen isotope fractionation for prolonged fasting arthropods.

    Science.gov (United States)

    Mizota, Chitoshi; Yamanaka, Toshiro

    2011-12-01

    Nitrogen acquisition for cellular metabolism during diapause is a primary concern for herbivorous arthropods. Analyses of naturally occurring stable isotopes of nitrogen help elucidate the mechanism. Relevant articles have cited (58 times up to mid-June 2011) anomalously elevated δ(15)N (per mil deviation of (15)N/(14)N, relative to atmospheric nitrogen=0 ‰) values (diet-consumer nitrogen isotope fractionation; up to 12 ‰) for a prolonged fasting raspberry beetle (Byturus tomentosus Degeer (Coleoptera: Byturidae)), which feeds on red raspberries (Rubus idaeus: δ(15)N= ~ +2 ‰). Biologists have hypothesised that extensive recycling of amino acid nitrogen is responsible for the prolonged fasting. Since this hypothesis was proposed in 1995, scientists have integrated biochemical and molecular knowledge to support the mechanism of prolonged diapausing of animals. To test the validity of the recycling hypothesis, we analysed tissue nitrogen isotope ratios for four Japanese arthropods: the shield bug Parastrachia japonensis Scott (Hemiptera: Cydnidae), the burrower bug Canthophorus niveimarginatus Scott (Hemiptera: Cydnidae), leaf beetle Gastrophysa atrocyanea Motschulsky (Coleoptera: Chrysomelidae) and the Japanese oak silkworm Antheraea yamamai (Lepidoptera: Saturniidae), all of which fast for more than 6 months as part of their life-history strategy. Resulting diet-consumer nitrogen isotope discrimination during fasting ranged from 0 to 7‰, as in many commonly known terrestrial arthropods. We conclude that prolonged fasting of arthropods does not always result in anomalous diet-consumer nitrogen isotope fractionation, since the recycling process is closed or nearly closed with respect to nitrogen isotopes. PMID:22166153

  8. Measurement of the relative branching ratio BR(\\Xi_c^+ \\to p^+ K^-\\pi^+)\\BR(\\Xi_c^+ \\to \\Xi^- \\pi^+ \\pi^+)

    CERN Document Server

    Link, J M; Yager, P M; Anjos, J C; Bediaga, I; Göbel, C; Magnin, J; Massafferri, A; De Miranda, J M; Pepe, I M; Dos Reis, A C; Simão, F R A; Carrillo, S; Casimiro, E; Sánchez-Hernández, A; Uribe, C; Vázquez, F; Cinquini, L; Cumalat, J P; O'Reilly, B; Ramírez, J E; Vaandering, E W; Butler, J N; Cheung, H W K; Gaines, I; Garbincius, P H; Garren, L A; Gottschalk, E E; Kasper, P H; Kreymer, A E; Kutschke, R; Bianco, S; Fabbri, Franco Luigi; Sarwar, S; Zallo, A

    2001-01-01

    We report the observation of the Cabibbo suppressed decay \\Xi_c^+ \\to p K^-\\pi^+ using data collected with the FOCUS spectrometer during the 1996--97 Fermilab fixed target run. We find a \\Xi_c^+ signal peak of 202\\pm35 events. We have measured the relative branching ratios BR(\\Xi^+_c\\to p K^-\\pi^+)/BR(\\Xi^+_c\\to\\Xi^-\\pi^+\\pi^+)= 0.234 \\pm 0.047 \\pm 0.022 and BR(\\Xi^+_c\\to p \\bar{K}^*(892)^0)/BR(\\Xi^+_c\\to p K^-\\pi^+)= 0.54 \\pm 0.09 \\pm 0.05 .

  9. Metathesis Polymerization Reactions Induced by the Bimetallic Complex (Ph4P2[W2(μ-Br3Br6

    Directory of Open Access Journals (Sweden)

    Despoina Chriti

    2015-12-01

    Full Text Available The reactivity of the bimetallic complex (Ph4P2[W2(μ-Br3Br6] ({W 2.5 W}7+, a′2e3 towards ring opening metathesis polymerization (ROMP of norbornene (NBE and some of its derivatives, as well as the mechanistically related metathesis polymerization of phenylacetylene (PA, is presented. Our results show that addition of a silver salt (AgBF4 is necessary for the activation of the ditungsten complex. Polymerization of PA proceeds smoothly in tetrahydrofuran (THF producing polyphenylacetylene (PPA in high yields. On the other hand, the ROMP of NBE and its derivatives is more efficient in CH2Cl2, providing high yields of polymers. 13C Cross Polarization Magic Angle Spinning (CPMAS spectra of insoluble polynorbornadiene (PNBD and polydicyclopentadiene (PDCPD revealed the operation of two mechanisms (metathetic and radical for cross-linking, with the metathesis pathway prevailing.

  10. No-carrier-added radiobromination via the Gattermann reaction. Synthesis of 75Br- and 77Br-bromperidol

    Energy Technology Data Exchange (ETDEWEB)

    Suehiro, Makiko; Yokoi, Fuji; Nozaki, Tadashi; Iwamoto, Masako

    1987-10-01

    The Gattermann reaction was applied to the non-carrier-added radiobromination of bromperidol. The synthesis with diazotized precursor, no-carrier-added 75Br- or 77Br-, and copper powder proved to give the radiobrominated neuroleptic drug in high radiochemical yield of 60 - 70 %, and in high specific activity (approx. 15 Ci/..mu..mole). The radiobromination also proved to be regio-selective. In the reaction, the copper catalyst was observed to play an important role. Formation of unlabeled by-products due to stable chlorine or bromine contamination in the reaction mixture was also studied by neutron activation analysis. Removal of such undesirable halogen nuclides and separation of the unavoidably-formed chlorinated compound from the radiobrominated bromperidol is discussed.

  11. No-carrier-added radiobromination via the Gattermann reaction. Synthesis of 75Br- and 77Br-bromperidol

    International Nuclear Information System (INIS)

    The Gattermann reaction was applied to the non-carrier-added radiobromination of bromperidol. The synthesis with diazotized precursor, no-carrier-added 75Br- or 77Br-, and copper powder proved to give the radiobrominated neuroleptic drug in high radiochemical yield of 60 - 70 %, and in high specific activity (∼ 15 Ci/μmole). The radiobromination also proved to be regio-selective. In the reaction, the copper catalyst was observed to play an important role. Formation of unlabeled by-products due to stable chlorine or bromine contamination in the reaction mixture was also studied by neutron activation analysis. Removal of such undesirable halogen nuclides and separation of the unavoidably-formed chlorinated compound from the radiobrominated bromperidol is discussed. (author)

  12. VSLS Bry estimation from SMILES BrO observation

    Science.gov (United States)

    Suzuki, Makoto; Shiotani, Masato; Mitsuda, Chihiro; Manago, Naohiro; Kinnison, Douglas; Imai, Koji; Ozeki, Hiroyuki

    Very Short Lived Source (VSLS) gases of Bry have been investigated, since it affects the chemistry of the stratosphere such as the long term recovery of the Ozone layer. VSLS Bry can be estimated from the difference of observed and model BrO value and the Bry/BrO calculated by the model. But previous VSLS Bry estimation spread over 4-8 ppt, due to the large uncertainty of the BrO observation. In this paper, we will report the SMILES (Superconducting Submillimeter-wave Limb Emission Sounder) BrO observation, and VSLS Bry estimation using SMILES L2 and Specified Dynamics WACCM Model (nudged to GEOS-5 data) calculation. SMILES operated on the ISS from Oct. 12, 2009 to Apr. 21, 2010. Since the detector (Superconductor-Insulator-Superconductor: SIS mixer) was cooled down to 4K, SMILES showed system noise figure, Tsys 250K, or spectral noise floor 0.4K, which gave one order better signal to noise ratio compared to previous sub-mm observations from space (Aura/MLS and Odin/SMR). SMILES VSLS Bry estimate (mean of 34 and 37 km) are about 4 pptv for Band A  (625 GHz), and about 5 pptv for Band C (650 GHz) for 10° latitude bins. Estimates become slightly lower in 30S-20S and 20S-10S, but are agreed within 4.63 5.27 pptv at 10S-50N at 34 km. VSLS Bry using v2.3 Band C BrO at 34 km as following, 30S-20S (3.26±0.66 pptv), 20S-10S (3.77±0.88), 10S-EQ (4.63±0.83), EQ-10N (4.67±0.58 ppt), 10N-20N (4.99±0.54), 20N-30N (5.27±0.59), 30N-40N (4.87±0.67). and 40N-50N (4.91±0.70).

  13. BrO in the arctic atmosphere in spring 2007

    Science.gov (United States)

    Prados Roman, C.; Butz, A.; Deutschmann, T.; Dorf, M.; Kritten, L.; Minikin, A.; Platt, U.; Schlager, H.; Pfeilsticker, K.

    2009-12-01

    Within the ASTAR 2007 campaign ("Arctic Study of Tropospheric Aerosol, Clouds and Radiation", IPY 2007/8) that took place in Svalbard (78°N) in April 2007, spectroscopic limb scattered skylight measurements were performed from aboard the DLR (Deutsches Zentrum für Luft- und Raumfahrt) Falcon aircraft. By applying the Differential Optical Absorption Spectroscopy technique (DOAS), we attempted to detect the mixing ratio vertical profiles of O3, NO2, BrO, OClO, IO, OIO, HONO, C2H2O2, CH2O, H2O and O4 from the boundary layer (BL), up to the lowermost stratosphere within the arctic atmosphere. Here we will focus on the detection of BrO and its vertical profile retrieval. Even though the limb DOAS measurements are extremely sensitive regarding the detection of trace gases (i.e., limit for the BrO detection ~1 pptv), the challenge of the profile retrieval comes with dealing appropriately with the actual Radiative Transfer (RT) processes in the atmosphere (e.g., Rayleigh and Mie scattering). Here, our approach is based on the retrieval of the Mie scattering extinction profile from measured radiance ratios, validated using in-situ measured aerosol and cloud particle concentrations. This information is then fed into forward RT calculations in order to obtain the proper kernel for mathematical inversion of the measured slant column absorption. The inverted O4 profile is used as a proof of the viability of this method and, finally, the vertical profile of the BrO mixing ratio is retrieved. In general, results of the ASTAR 2007 flights indicate that bromine explosions and ozone depletion events (ODEs) were occurring above the arctic first-year sea ice in non-hazy conditions in April 2007. In particular, the flight on the 8th April 2007 shows largely depleted O3 (environment will be presented. In addition, the source of our BrO data will be discussed (e.g. BL or stratospheric signal, etc).

  14. Ustioni da fuoco / Burn injuries / Les brûlures

    Directory of Open Access Journals (Sweden)

    Liliana Copertino

    2008-04-01

    Full Text Available Severe burn injuries require high specialistic treatment. Burn injuries are common in disasters and war scenarios, so war medicine has been fundamental to improve treatment protocols for burn patients..Burn injuries are classified according to the etiopathogenetic agent (physical, chemical or radiation, that determines different anatomoisthologic aspects.An estimation of the depth and extension are fundamental for defining the gravity of the burn. Critical burn patients have to be transported in specialistic Centers. There they are treated by multispecialistic teams from the resuscitation phase to the reconstructive surgery and specialist rehabilitation.. This process can continue for two years with the objective to return patients to a quiet normal life. Les brûlures sont des lésions traumatiques qui requièrent un traitement spécialisé. Lors de catastrophes et de guerres, les brûlures sont des lésions très fréquentes et la médecine de guerre a contribué à faire avancer la science de manière importante, dans le traitement de cette pathologie.Les brûlures sont classées en fonction de l'agent étiopathogénique (agents physiques, chimiques ou radiations dont le mécanisme d'action qui provoque la lésion cause des aspects anatomohistologiques caractéristiques.Pour définir la sévérité d'une brûlure, il est aussi fondamental d'éstimer l'extension de la surface corporelle et la profondeur de l'épiderme, et éventuellement du derme, atteints. Les patients gravement brûlés doivent être hospitalisés dans des Centres Spécialisés où des équipes multispécialistes les suivent de la phase initiale de la réanimation aux phases de chirurgie reconstructive et au processus de réhabilitation. Ces dernières phases peuvent se prolonger pendant les deux années suivant le traumatisme avant qu'une réintégration dans une vie sociale acceptable ne puisse être faite.

  15. Isotopic characteristics of canopies in simulated leaf assemblages

    Science.gov (United States)

    Graham, Heather V.; Patzkowsky, Mark E.; Wing, Scott L.; Parker, Geoffrey G.; Fogel, Marilyn L.; Freeman, Katherine H.

    2014-11-01

    The geologic history of closed-canopy forests is of great interest to paleoecologists and paleoclimatologists alike. Closed canopies have pronounced effects on local, continental and global rainfall and temperature patterns. Although evidence for canopy closure is difficult to reconstruct from the fossil record, the characteristic isotope gradients of the "canopy effect" could be preserved in leaves and proxy biomarkers. To assess this, we employed new carbon isotopic data for leaves collected in diverse light environments within a deciduous, temperate forest (Maryland, USA) and for leaves from a perennially closed canopy, moist tropical forest (Bosque Protector San Lorenzo, Panamá). In the tropical forest, leaf carbon isotope values range 10‰, with higher δ13Cleaf values occurring both in upper reaches of the canopy, and with higher light exposure and lower humidity. Leaf fractionation (Δleaf) varied negatively with height and light and positively with humidity. Vertical 13C enrichment in leaves largely reflects changes in Δleaf, and does not trend with δ13C of CO2 within the canopy. At the site in Maryland, leaves express a more modest δ13C range (∼6‰), with a clear trend that follows both light and leaf height. Using a model we simulate leaf assemblage isotope patterns from canopy data binned by elevation. The re-sampling (bootstrap) model determined both the mean and range of carbon isotope values for simulated leaf assemblages ranging in size from 10 to over 1000 leaves. For the tropical forest data, the canopy's isotope range is captured with 50 or more randomly sampled leaves. Thus, with a sufficient number of fossil leaves it is possible to distinguish isotopic gradients in an ancient closed canopy forest from those in an open forest. For very large leaf assemblages, mean isotopic values approximate the δ13C of carbon contributed by leaves to soil and are similar to observed δ13Clitter values at forested sites within Panamá, including the

  16. Transportation of medical isotopes

    International Nuclear Information System (INIS)

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document

  17. Science policy up close

    CERN Document Server

    Marburger, John H

    2015-01-01

    In a career that included tenures as president of Stony Brook University, director of Brookhaven National Laboratory, and science advisor to President George W. Bush, John Marburger (1941 2011) found himself on the front line of battles that pulled science ever deeper into the political arena. From nuclear power to global warming and stem cell research, science controversies, he discovered, are never just about science. Science Policy Up Close" presents Marburger s reflections on the challenges science administrators face in the twenty-first century. In each phase of public service Marburger came into contact with a new dimension of science policy. The Shoreham Commission exposed him to the problem of handling a volatile public controversy over nuclear power. The Superconducting Super Collider episode gave him insights into the collision between government requirements and scientists expectations and feelings of entitlement. The Directorship of Brookhaven taught him how to talk to the public about the risks ...

  18. Vortices on closed surfaces

    CERN Document Server

    Boatto, Stefanella

    2008-01-01

    We consider $N$ point vortices $s_j$ of strengths $\\kappa_j$ moving on a closed (compact, boundaryless, orientable) surface $S$ with riemannian metric $g$. As far as we know, only the sphere or surfaces of revolution, the latter qualitatively, have been treated in the available literature. The aim of this note is to present an intrinsic geometric formulation for the general case. We give a simple proof of Kimura's conjecture that a dipole describes geodesic motion. Searching for integrable vortex pairs systems on Liouville surfaces is in order. The vortex pair system on a triaxial ellipsoid extends Jacobi's geodesics. Is it Arnold-Liouville integrable? Not in our wildest dreams is another possibility: that quantizing a vortex system could relate with a million dollars worth question, but we took courage - nerve is more like it - to also present it.

  19. "Brücke dreht sich um!". A Deconstructionist Reading of Kafka's "Die Brücke"

    Directory of Open Access Journals (Sweden)

    Eva Hoffmann

    2014-12-01

    Full Text Available Franz Kafka's (1883-1924 "Die Brücke" is one of the less well-known texts by one of the most prolific authors of literary modernity. However, this short prose text embodies prevalent questions of literary modernity and philosophy as it reflects the crisis of language in regard of identity, communication, and literary production. Placed in the context of fin-de-siècle's discourse of language crisis, this article provides a dialogue between Kafka's "Die Brücke" and Hannah Arendt's (1906-1975 philosophy of thinking and speaking in The Life of the Mind. Contrary to Arendt's understanding of the metaphor as "a carrying over" between the mental activities of the solitude thinker and a reconciliation with the pluralistic world shared with others, this article argues for a deconstructionist reading of "Die Brücke" as a tool to reevaluate Arendt's notion of a shared human experience ensured through language and illustrates the advantages of poetic texts within philosophical discourses.

  20. Improved Growth Methods for LaBr3 Scintillation Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S

    2011-05-01

    The objective is to develop advanced materials for deployment as high-resolution gamma ray detectors. Both LaBr3 and CeBr3 are advanced scintillation materials, and will be studied in this research. Prototype devices, in collaboration Sandia National Laboratories, will be demonstrated along with recommendations for mass production and deployment. It is anticipated that improved methods of crystal growth will yield larger single crystals of LaBr3 for deployable room-temperature operated gamma radiation spectrometers. The growth methods will be characterized. The LaBr3 and CeBr3 scintillation crystals will be characterized for light yield, spectral resolution, and for hardness.

  1. Improved Growth Methods for LaBr3 Scintillation Radiation Detectors

    International Nuclear Information System (INIS)

    The objective is to develop advanced materials for deployment as high-resolution gamma ray detectors. Both LaBr3 and CeBr3 are advanced scintillation materials, and will be studied in this research. Prototype devices, in collaboration Sandia National Laboratories, will be demonstrated along with recommendations for mass production and deployment. It is anticipated that improved methods of crystal growth will yield larger single crystals of LaBr3 for deployable room-temperature operated gamma radiation spectrometers. The growth methods will be characterized. The LaBr3 and CeBr3 scintillation crystals will be characterized for light yield, spectral resolution, and for hardness.

  2. Molecular elimination of Br{sub 2} in photodissociation of CH{sub 2}BrC(O)Br at 248 nm using cavity ring-down absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fan He; Tsai, Po-Yu; Lin, King-Chuen [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lin, Cheng-Wei; Yan, Chi-Yu; Yang, Shu-Wei; Chang, A. H. H. [Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan (China)

    2012-12-07

    The primary elimination channel of bromine molecule in one-photon dissociation of CH{sub 2}BrC(O)Br at 248 nm is investigated using cavity ring-down absorption spectroscopy. By means of spectral simulation, the ratio of nascent vibrational population in v = 0, 1, and 2 levels is evaluated to be 1:(0.5 {+-} 0.1):(0.2 {+-} 0.1), corresponding to a Boltzmann vibrational temperature of 581 {+-} 45 K. The quantum yield of the ground state Br{sub 2} elimination reaction is determined to be 0.24 {+-} 0.08. With the aid of ab initio potential energy calculations, the obtained Br{sub 2} fragments are anticipated to dissociate on the electronic ground state, yielding vibrationally hot Br{sub 2} products. The temperature-dependence measurements support the proposed pathway via internal conversion. For comparison, the Br{sub 2} yields are obtained analogously from CH{sub 3}CHBrC(O)Br and (CH{sub 3}){sub 2}CBrC(O)Br to be 0.03 and 0.06, respectively. The trend of Br{sub 2} yields among the three compounds is consistent with the branching ratio evaluation by Rice-Ramsperger-Kassel-Marcus method. However, the latter result for each molecule is smaller by an order of magnitude than the yield findings. A non-statistical pathway so-called roaming process might be an alternative to the Br{sub 2} production, and its contribution might account for the underestimate of the branching ratio calculations.

  3. Laser isotope separation techniques

    International Nuclear Information System (INIS)

    Having examined the high cost and low efficiency of existing processes for separating uranium isotopes in comparison with the encouraging assessed figures for laser separation processes and having considered the high potential separation factors which make possibly very low 235U concentrations in the depleted tailings from laser separation processes, the design of such a system is considered. There are two essential features. Firstly, only one isotope must absorb laser radiation, and secondly that absorption must lead to a successful physical or chemical separation of that species which has been optically excited. Such a scheme is illustrated and discussed. The important aspect of loss mechanisms which can depopulate the selectively excited levels and the ways in which isotopes may exhibit differences in optical absorption frequencies are considered. Examples are given to illustrate techniques used in the separation stage. Finally a summary is presented of those elements in which some enrichment has been achieved by optical techniques. (U.K.)

  4. Lithium isotope separation

    International Nuclear Information System (INIS)

    Published methods for 6Li-7Li lithium isotope separation have been reviewed. Future demand for 6Li, whose main use will be as a tritium breeder in blankets surrounding the core of DT fusion power reactors, is likely to exceed 5 Mg/a in the next century. The applicability of the various available methods to such a large scale production rate has been assessed. Research on improving the effectiveness of current lithium isotope separation processes has been carried out worldwide in several major areas during the past decade; these include two-phase chemical exchange systems, ion exchange resin chromatography, highly isotope-selective techniques like laser photoactivation and radiofrequency spectroscopy. Chemical exchange systems appear to offer good potential in the near term for 6Li enrichment

  5. Biological Sources of Branched Glycerol Dialkyl Glycerol Tetraethers (brGDGTs) in Terrestrial Hot Springs: A Possible Link Between Nitrogen-cycling Bacteria and brGDGT Production

    Science.gov (United States)

    Wang, J. X.; Xie, W.; Boyd, E. S.; Hedlund, B. P.; Zhang, C.

    2014-12-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are common in peat, soil, lakes, rivers and hot springs. To seek the potential biological sources of brGDGTs in geothermal environments, we investigated 65 hot springs in the Yellowstone National Park (USA) and Tengchong (China). Together with previously published data from hot springs in the Great Basin (USA) and Tibet (China), we found that the abundance of brGDGTs tended to peak in springs with pH > 8. This contrasts with previous observations indicating an abundance of brGDGTs in acidic soils and peat bogs, suggesting a different biological source and function for lipids in these environments. In support of this hypothesis, a comparison of Cyclization ratios of Branched Tetraethers (CBT) between hot springs and surrounding soils indicated that more brGDGTs with cyclopentane moieties were produced in alkaline hot springs than in nearby low-temperature soils. Since Acidobacteria (the likely source of brGDGTs in peat bog environments) tend to have low CBT ratios, these data suggest a different source for brGDGTs in hot spring environments. RDA and regression analysis integrating brGDGT compounds and nitrogen species indicate that Bacteria involved in the nitrogen biogeochemical cycle (ammonia oxidation and nitrite reduction) may be related to the production of brGDGTs in terrestrial hot springs. However, direct evidence showing the link between nitrogen-cycling bacteria and brGDGT production has yet to be demonstrated under laboratory conditions. Nevertheless, our study expands the possibility of brGDGT sources into bacterial communities in terrestrial geothermal systems where Acidobacteria are absent or only a minor component.

  6. Isotopes in condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Plekhanov, Vladimir G. [Computer Science College, Tallinn (Estonia). Mathematics and Physics Dept.

    2013-07-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed. The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  7. Isotopes in Condensed Matter

    CERN Document Server

    G Plekhanov, Vladimir

    2013-01-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe  in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed.  The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  8. Environmental isotope survey

    International Nuclear Information System (INIS)

    Work was initiated on the 1st of September 1971 with the objective of finding out how best to use environmental isotopes in the interpretation of the hydrology, particularly subsurface hydrology, of Cyprus through a sparse reconnaissance sampling of all the major aquifers and springs covering the whole island. The distribution of sampling was such that the survey in itself could assist in clarifying particular hydrogeologic problems, provide a better understanding of the water systems of the island, establish a general environmental isotope - framework of the hydrologic regimen of Cyprus as well as to provide the basis for specific, more detailed, studies to be undertaken subsequently

  9. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  10. Zinc isotope anomalies

    International Nuclear Information System (INIS)

    The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion. 32 refs

  11. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  12. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  13. Geochemistry of the Halogens (I, Br, Cl) and Evolution of the Seawater During the Archean

    Science.gov (United States)

    Avice, G.; Marty, B.; Burgess, R.; Goldsmith, S. L.

    2015-12-01

    Halogens (I, Cl, Br) on Earth are depleted relative to the results of the condensation sequence of elements from the solar nebula [1]. The cause of this depletion remains unknown but might be related to loss from impacts or to the presence of an hidden reservoir (e.g. core). The presence of fluid inclusions in hydrothermal quartz of various ages is an opportunity to follow the evolution of the composition of the atmosphere (N, noble gases) through time [2] but also of halogens in seawater (their main reservoir). Such studies may help to constrain what is the origin of these volatile elements on Earth. For this purpose, we analysed quartz from hydrothermal veins and pods of various localities and ages (e.g. Barberton Greenstone Belt (South Africa; 3.2 Ga), Fortescue Group (Australia; 2.7 Ga)) by crushing and step-heating following the extended Ar-Ar method [3]. In Barberton and Fortescue Gp. quartz, a hydrothermal component characterized by excess 40Ar (40ArE) and closely associated with chlorine is clearly identified from crushing and step-heating results and permits to define a 40ArE/Cl used to correct Ar-Ar data for this contribution. In the case of Barberton, the correction for the hydrothermal component leads to an approximate formation age of the quartz of 3.2 (+/- 0.1) Ga. In Barberton quartz, halogens elemental ratios obtained during crushing and step-heating experiments are highly enriched in iodine and bromine (I/Cl=2-7x10-4; Br/Cl=4-10x10-3) relative to modern seawater. These results are similar to those found in a previous study of Barberton fluid inclusions [3] and can be interpreted as indicators that organic carbon was not sufficiently abundant at this time and/or this location to efficiently pump Br and I during sediment burial. Iodine and bromine, in Fortescue Gp. quartz, are less enriched suggesting that, in that case, organic activity already acted as pump for these elements. [1] Sharp & Draper (2013) EPSL, 369-370, p. 71-77 [2] Pujol et al. (2011

  14. Stratospheric ozone isotope enrichment studied by submillimeter-wave heterodyne radiometry

    Science.gov (United States)

    Kasai, Y.; Urban, J.; Takahashi, K.; JEM/SMILES Science-Team,

    2002-05-01

    Since the discovery of the heavy isotope enrichment of ozone formation in the stratosphere in 1981, considerable progress has been made in understanding the processes that control the isotope enrichment by using mass spectrometry, spectrometric techniques, laboratory measurements, and so on. The detection limit of the mass spectrometers is enough to discuss these isotope enrichments, but symmetric and asymmetric ozone isotopes cannot be distinguished. It is important to observe symmetric and asymmetric ozone isotopes separately with enough accuracy to understand the mechanism of the ozone isotope enrichment for the ozone formation chemistry. Measurements of the ozone isotopes using a new technology of he superconducting submillimeter-wave limb emission spectrometer (SMILES) have been proposed. The instrument is planned to be aboard the Japanese Experiment Module (JEM) at the International Space Station. The SMILES instrument is planned to be launched in 2006. The SMILES instrument measures thermal emissions from ozone isotopes as well as ozone-depletion-related molecules such as ClO, HCl, HO2, HNO3 and BrO in the frequency bands at 624.32-626.32 GHz and 649.12-650.32 GHz. Overview of this experiment, such as new techniques for a high-sensitive sounding, measurement coverage, measurement frequency, is described. The scientific objective of the SMILES experiment, including a brief review on the controversial problem of stratospheric ozone isotope anomaly, is presented. The error analysis of the SMILES measurement is evaluated by using the SMILES simulator for all 5 isotopes of normal ozone, asymmetric-17-ozone, asymmetric-18-ozone, symmetric-17-ozone, symmetric-18-ozone. The evaluation suggests that the global distributions of symmetric-17-ozone, asymmetric-18-ozone, symmetric-17-ozone, as well as normal ozone can be obtained from the single profile, with the errors of less than about 1 % between 20 and 40 km with the partial column about 5 km.

  15. Global modelling of H2 mixing ratios and isotopic compositions with the TM5 model

    Directory of Open Access Journals (Sweden)

    R. L. Langenfelds

    2011-07-01

    Full Text Available The isotopic composition of molecular hydrogen (H2 contains independent information for constraining the global H2 budget. To explore this, we have implemented hydrogen sources and sinks, including their stable isotopic composition and isotope fractionation constants, into the global chemistry transport model TM5. For the first time, a global model now includes a simplified but explicit isotope reaction scheme for the photochemical production of H2. We present a comparison of modelled results for the H2 mixing ratio and isotope composition with available measurements on seasonal to inter annual time scales for the years 2001–2007. The base model results agree well with observations for H2 mixing ratios. For δD[H2], modelled values are slightly lower than measurements. A detailed sensitivity study is performed to identify the most important parameters for modelling the isotopic composition of H2. The results show that on the global scale, the discrepancy between model and measurements can be closed by adjusting the default values of the isotope effects in deposition, photochemistry and the stratosphere-troposphere exchange within the known range of uncertainty. However, the available isotope data do not provide sufficient information to uniquely constrain the global isotope budget. Therefore, additional studies focussing on the isotopic composition near the tropopause and on the isotope effects in the photochemistry and deposition are recommended.

  16. The closed fuel cycle

    International Nuclear Information System (INIS)

    Available in abstract form only. Full text of publication follows: The fast growth of the world's economy coupled with the need for optimizing use of natural resources, for energy security and for climate change mitigation make energy supply one of the 21. century most daring challenges. The high reliability and efficiency of nuclear energy, its competitiveness in an energy market undergoing a new oil shock are as many factors in favor of the 'renaissance' of this greenhouse gas free energy. Over 160,000 tHM of LWR1 and AGR2 Used Nuclear Fuel (UNF) have already been unloaded from the reactor cores corresponding to 7,000 tons discharged per year worldwide. By 2030, this amount could exceed 400,000 tHM and annual unloading 14,000 tHM/year. AREVA believes that closing the nuclear fuel cycle through the treatment and recycling of Used Nuclear Fuel sustains the worldwide nuclear power expansion. It is an economically sound and environmentally responsible choice, based on the preservation of natural resources through the recycling of used fuel. It furthermore provides a safe and secure management of wastes while significantly minimizing the burden left to future generations. (authors)

  17. Ganymede - close up photos

    Science.gov (United States)

    1979-01-01

    Two close-up photos of Ganymede, largest of Jupiter's 13 moons, were obtained on July 8 by Voyager 2 from 86,000 miles (top) and 192,000 miles. They show different views of the largest block of dark, heavily cratered terrain seen on the giant moon. The bottom image shows objects three to four miles across; has a resolution of about 1.5 miles. The light, linear stripes recurring across the dark region resemble the outer rings of the large ring structure on Callisto. If these features are in fact related to an ancient ring structure formed by a large impact, their small curvature suggests that the original structure was even larger than one seen on Callisto. There is no apparent trace now of the center of this suggested structure, which must have been destroyed by the resurfacing evident over most of Ganymede in the grooved terrain. Another interpretation is that these features are not impact-related rings but are internally produced fractures crossing the dark terrain, similar to the grooved bands.

  18. X-ray transitions in Br XXIV-XXVIII

    International Nuclear Information System (INIS)

    Transitions in the wavelength region 4.9-8.1 A from Br , , , , and have been identified in spectra from laser-produced plasmas. The identifications were made using ab initio calculations of wavelengths and oscillator strengths. Spatially resolved spectra were recorded for laser irradiation intensities from 3 x 10/sup 13/ to 4 x 10/sup 14/ W/cm2. The dependence of the spectral lines on the distance from the target and on the irradiation intensity was very useful in distinguishing the transitions from different ionization stages

  19. Brüssel enne Moskvat / Markus Meckel, Matthias Wissmann

    Index Scriptorium Estoniae

    Meckel, Markus

    2005-01-01

    Saksa liiduparlamendi sotsiaaldemokraatide fraktsiooni liikme Markus Meckeli ja Saksa liiduparlamendi Euroopa komisjoni esimehe Matthias Wissmanni avaldus, milles nad kutsuvad tunnistama Balti riikide ajalugu ja korraldama päev enne Moskvas toimuvat Teise maailmasõja lõppu tähistavat üritust Brüsselis sõja lõpu 60. aastapäeva mälestusürituse. Artikkel ilmus samaaegselt ajalehtedes International Herald Tribune, Die Welt, Die Presse, Le Figaro, Gazeta Wyborcza, Lietuvas rytas, Diena

  20. Planetary3br: Three massive body resonance calculator

    Science.gov (United States)

    Gallardo, Tabaré

    2016-07-01

    Given two planets P1 and P2 with arbitrary orbits, planetary3br calculates all possible semimajor axes that a third planet P0 can have in order for the system to be in a three body resonance; these are identified by the combination k0*P0 + k1*P1 + k2*P2. P1 and P2 are assumed to be not in an exact two-body resonance. The program also calculates three "strengths" of the resonance, one for each planet, which are only indicators of the dynamical relevance of the resonance on each planet. Sample input data are available along with the Fortran77 source code.

  1. Refurbishment of BR2 (Phases 4 and 5)

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P.; Dekeyser, J.; Van Der Auwera, J

    1998-07-01

    The BR2 is a materials testing reactor and is SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In phase 4 of the refurbishment programme, various activities were performed to allow reactor start-up. In phase 5, remaining refurbishment works were carried out as well as the extra studies and upgradings required by the licensing authorities. Major achievements in 1997 are described and discussed.

  2. PHARMACOGNOSTIC AND PHYTOCHEMICAL STUDY OF CHLOROPHYTUM LAXUM R. BR.

    Directory of Open Access Journals (Sweden)

    Patil Vishal Narayan

    2011-06-01

    Full Text Available Chlorophytum laxum R. Br. belongs to family Liliaceae and is being used in the indigenous systems of medicine as a galactogogue and aphrodisiac. It is being sold in the market under the common name “safed musali”. The white tuberous roots of this plant are the medicinally useful parts. The tuberous roots of other species of Chlorophytum, Asparagus, Bombax and Orchids are also sometimes called safed musali leading to confusion. In order to ensure correct botanical standardization, the detailed pharmacognostic study on tuberous roots of Chlorophytum laxum has been carried out in this study.

  3. Adidas Suomi Oy: Brändikuvan rakentaminen markkinoinnin keinoin

    OpenAIRE

    Leinonen, Miira

    2015-01-01

    Tämä opinnäytetyö tehtiin toimeksiantona Adidas Suomi Oy:lle syksyllä 2014. Opinnäytetyön tavoitteena oli selvittää muotialan mielipidevaikuttajien mielikuvat Adidaksesta ja sen merkittävimmistä kilpailijoista. Vertailtaviksi brändeiksi valittiin kuusi tärkeintä kilpailijaa, jotka ovat Converse, Karhu, New Balance, Nike, Puma ja Reebok. Opinnäytetyön toimeksiantaja Adidas Suomi Oy on osa kansainvälistä Adidas Group konsernia. Yritys on yksi maailman tunnetuimmista urheilumerkeistä ja toim...

  4. Competing C-Br and O-NO Photofission upon Excitation of BrCH2CH2ONO at 193 nm.

    Science.gov (United States)

    Wang, Lei; Scrape, Preston G; Roberts, Trevor D; Joshi, Prakriti P; Butler, Laurie J

    2015-12-17

    This study characterizes two of the primary photodissociation channels of 2-bromoethyl nitrite, BrCH2CH2ONO, at 193 nm and the subsequent unimolecular dissociation channels of the nascent vibrationally excited BrCH2CH2O radicals produced from the O-NO bond photofission. We use a crossed laser-molecular beam scattering apparatus with electron bombardment detection. Upon photodissociation of BrCH2CH2ONO at 193 nm, the measured branching ratio between primary O-NO photofission and C-Br photofission is 3.9:1 (O-NO/C-Br). The measured O-NO photofission recoil kinetic energy distribution (P(ET)) peaks near 30 kcal/mol and extends from 20 to 50 kcal/mol. We use the O-NO photofission P(ET) to characterize the internal energy distribution in the nascent ground-electronic-state BrCH2CH2O radicals. At 193 nm, all of the BrCH2CH2O radicals are formed with enough internal energy to unimolecularly dissociate to CH2Br + H2CO or to BrCH2CHO + H. We also investigated the possibility of the BrCH2CH2O → CH2CHO + HBr reaction arising from the vibrationally excited BrCH2CH2O radicals produced from O-NO primary photodissociation. Signal strengths at HBr(+), however, demonstrate that the vinoxy product does not have HBr as a cofragment, so the BrCH2CH2O → HBr + vinoxy channel is negligible compared to the CH2Br + H2CO channel. We also report our computational prediction of the unimolecular dissociation channels of the vibrational excited CH2CH2ONO radical resulting from C-Br bond photofission. Our theoretical calculations on the ground-state CH2CH2ONO potential energy surface at the G4//B3LYP/6-311++G(3df,2p) level of theory give the energetics of the zero-point corrected minima and transition states. The lowest accessible barrier height for the unimolecular dissociation of CH2CH2ONO is a 12.7 kcal/mol barrier from the cis-ONO conformer, yielding NO2 + ethene. Our measured internal energy distribution of the nascent CH2CH2ONO radicals together with this computational result suggests

  5. Discoveries of isotopes by fission

    Indian Academy of Sciences (India)

    M Thoennessen

    2015-09-01

    Of the about 3000 isotopes presently known, about 20% have been discovered in fission. The history of fission as it relates to the discovery of isotopes as well as the various reaction mechanisms leading to isotope discoveries involving fission are presented.

  6. 81Br, 37Cl, and 87Sr studies to assess groundwater flow and solute sources in the southwestern Great Artesian Basin, Australia

    International Nuclear Information System (INIS)

    The Great Artesian Basin (GAB) is a water source for more than 200,000 residents in central Australia. This study investigates the relationship of bromine and chlorine stable isotopes to groundwater chemistry in a confined aquifer in the southwestern GAB to better understand its flow regime and solute sources. δ81Br values range from +0.660/00 near the recharge area to +1.04 0/00, 150 km down gradient, while δ37Cl ranges from 00/00 to -2.50/00. While δ37Cl decreases with distance from the recharge area, δ81Br increases slightly. Bromide in the recharge area is possibly enriched from selective atmospheric processes causing fractionation in marine aerosols during transport. When confined and isolated from the atmosphere, increases in bromide and to a lesser extent strontium concentrations may contribute through water-rock interaction to changes in isotopic signatures along the flow system. 87Sr/86Sr values range from ∼0.717 near the recharge zone to a depleted 0.708 160 km down gradient. (authors)

  7. Nitrosyl bromo complexes of rhenium: Re(NO)2Br3 and [Re(NO)2Br4]-; crystal structure of PPh4[Re(NO)2Br4] . 2 CCl4

    International Nuclear Information System (INIS)

    PPh4[Re(NO)2Br4] is prepared in the form of dark red-brown powder by the reaction of PPh4[Re(NO)2Cl4] with excess boron tribromide. From a solution of CH2Br2 and CCl4 it crystallizes with two moles CCl4, one of which splits off easily in vacuo. The reaction of aluminium tribromide in CH2Br2 solution leads to a slightly soluble red-brown Re(NO)2Br3 powder. The i.r. spectra indicate cis positions of the covalently bound NO ligands in both complexes. Re(NO)2Br3 is dimeric via bromo bridges. The crystal structure determination of PPh4[Re(NO)2Br4] . 2 CCl4 was solved by X-ray diffraction methods at -115 0C. The complex crystallizes in the monoclinic space group P21/c with four formula units per unit cell (4434 independent reflexions, R = 0.085). The unit cell dimensions are a = 1092.3 pm, b = 2088.0 pm, c = 1657.6 pm, β = 96.100. The structure consists of P(C6H5)4+ cations, [Re(NO)2Br4]- anions and intercalated CCl4 molecules. In the anion the NO groups are covalently bound to the Re atom like Re-=N+=O and they are arranged in cis position to one another. (author)

  8. Dynamics of endoergic substitution reactions. II. Br+/C2H2Cl2/→Cl+/C2H2ClBr/

    International Nuclear Information System (INIS)

    We have extended the crossed beams studies described in the preceding paper to the reactions of Br atoms with 1,1- and trans-dichloroethylene. The shapes of the product translational energy distributions and excitation functions for both reactions support our previous conclusion that Cl elimination from Br--R--Cl collision complexes can compete with Br elimination only in the limit that few vibrational modes of the complex are active in energy redistribution. The substitution cross section for the Br+CH2CCl2 reaction is considerably lower than that for the Br+trans-CHClCHCl reaction in the collision energy range 15--25 kcal/mol, suggesting that steric effects play a dominant role in determining the relative magnitudes of the cross sections

  9. Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI

    International Nuclear Information System (INIS)

    We report a beam-foil study of multiply ionized bromine in the region 400-1300A, performed with 6 and 8 MeV Br ions from a tandem accelerator. At these energies transitions belonging to Fe-like Br X and Mn-like Br XI are expected to be prominent. We have identified 31 lines as 3d74s-3d74p transitions in Br X, from which 16 levels of the previously unknown 3d74s configuration could be established. We have also added 6 new 3d74p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d64s-3d64p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)

  10. Nuclear medical isotope research

    International Nuclear Information System (INIS)

    81Rb is produced in high specific activity and yield by the reaction 79Br(α,2n)81Rb. The 81Rb is purified and absorbed on an ion-exchange column in a minigenerator, which allows the elution, at a rapid rate, of the /SUP 81m/Kr daughter in a biologically compatible, sterile solution. Applications of /sup 81m/Kr are described. Chemical binding in tumor cells is being studied and the use of /sup 134m/Cs for myocardial scanning is being evaluated. (U.S.)

  11. Close to the Sky

    Science.gov (United States)

    2007-11-01

    Today, a new ALMA outreach and educational book was publicly presented to city officials of San Pedro de Atacama in Chile, as part of the celebrations of the anniversary of the Andean village. ESO PR Photo 50a/07 ESO PR Photo 50a/07 A Useful Tool for Schools Entitled "Close to the sky: Biological heritage in the ALMA area", and edited in English and Spanish by ESO in Chile, the book collects unique on-site observations of the flora and fauna of the ALMA region performed by experts commissioned to investigate it and to provide key initiatives to protect it. "I thank the ALMA project for providing us a book that will surely be a good support for the education of children and youngsters of San Pedro de Atacama. Thanks to this publication, we expect our rich flora and fauna to be better known. I invite teachers and students to take advantage of this educational resource, which will be available in our schools", commented Ms. Sandra Berna, the Mayor of San Pedro de Atacama, who was given the book by representatives of the ALMA global collaboration project. Copies of the book 'Close to the sky' will be donated to all schools in the area, as a contribution to the education of students and young people in northern Chile. "From the very beginning of the project, ALMA construction has had a firm commitment to environment and local culture, protecting unique flora and fauna species and preserving old estancias belonging to the Likan Antai culture," said Jacques Lassalle, who represented ALMA at the hand-over. "Animals like the llama, the fox or the condor do not only live in the region where ALMA is now being built, but they are also key elements of the ancient Andean constellations. In this sense they are part of the same sky that will be explored by ALMA in the near future." ESO PR Photo 50c/07 ESO PR Photo 50c/07 Presentation of the ALMA book The ALMA Project is a giant, international observatory currently under construction on the high-altitude Chajnantor site in Chile

  12. Isotope effect on the zero point energy shift upon condensation

    International Nuclear Information System (INIS)

    The various isotope-dependent and independent atomic and molecular properties that pertain to the isotopic difference between the zero point energy (ZPE) shifts upon condensation were derived. The theoretical development of the change of the ZPE associated with the internal molecular vibrations, due to the condensation of the gaseous molecules, is presented on the basis of Wolfsberg's second-order perturbation treatment of the isotope-dependent London dispersion forces between liquid molecules. The isotope effect on the ZPE shift is related to the difference between the sums of the integrated intensities of the infrared absorption bands of the two gaseous isotopic molecules. The effective atomic charges are also calculated from available experimental infrared intensity data. The effects of isotopic substitutions of carbon-13 for carbon-12 and/or deuterium for protium, in ethylene, methane, and the fluorinated methanes, CH3F, CH2F2, CHF3, and CF4, on the ZPE shift upon condensation are calculated. These results compare well with the Bigeleisen B-factors, which are experimentally obtained from vapor pressure measurements of the isotopic species. Each of the following molecular properties will tend to increase the isotopic difference between the ZPE shifts upon condensation: (1) large number of highly polar bonds, (2) high molecular weight, (3) non-polar (preferably) or massive molecule, (4) non-hydrogenous molecule, and (5) closely packed liquid molecules. These properties will result in stronger dispersion forces in the liquid phase between the lighter molecules than between the isotopically heavier molecules. 36 tables, 9 figures

  13. Isotopic ratios at z=0.68 from molecular absorption lines toward B 0218+357

    CERN Document Server

    Wallstrom, S H J; Guelin, M

    2016-01-01

    Isotopic ratios of heavy elements are a key signature of the nucleosynthesis processes in stellar interiors. The contribution of successive generations of stars to the metal enrichment of the Universe is imprinted on the evolution of isotopic ratios over time. We investigate the isotopic ratios of carbon, nitrogen, oxygen, and sulfur through millimeter molecular absorption lines arising in the z=0.68 absorber toward the blazar B 0218+357. We find that these ratios differ from those observed in the Galactic interstellar medium, but are remarkably close to those in the only other source at intermediate redshift for which isotopic ratios have been measured to date, the z=0.89 absorber in front of PKS1830-211. The isotopic ratios in these two absorbers should reflect enrichment mostly from massive stars, and they are indeed close to the values observed toward local starburst galaxies. Our measurements set constraints on nucleosynthesis and chemical evolution models.

  14. Isotope hydrology experiments

    International Nuclear Information System (INIS)

    From the concentrations of H2 and O18 in the examined ground waters in the Lower Muschelkalk of the SW flank of the Asse mine it can be inferred that the flow field of the ground water with the isotopic composition of the recent precipitations has an effect down to a depth of only 611 to 744 m. (DG)

  15. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  16. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090432 Zhou Shuqing (School of Energy Resources, China University of Geosciences Beijing 100083, China); Huang Haiping Stable Isotopic Records vs. Important Events in Life Evolution and the Concurrent Environment (Geological Review, ISSN0371-5736, CN11-1952, 54(2), 2008, p.225-231, 3 illus., 1 table, 77 refs.)

  17. Isotopes in aquaculture research

    International Nuclear Information System (INIS)

    The applications of isotopes in aquaculture research include areas like aquatic production process, nutrient cycles and food chain dynamics, fish nutrition, fish physiology, genetics and immunology. The radioisotopes commonly used are beta emitters. The use of different radioisotopes in aquaculture research are presented. 2 tabs

  18. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  19. Isotopic geochemistry of calcretes

    International Nuclear Information System (INIS)

    Sr, C, O, U and Th isotopes have been studied in calcium carbonates accumulated in soils of semi-arid regions (calcretes). We have investigated 1) the role of in-situ weathering and climatic conditions in the genesis of calcretes from Central Spain (Toledo) and Atlantic Morocco (Sidi Ifni), 2) the origin of Ca, and 3) the age of these accumulations. Our results show that calcium carbonates replace the parent rock (granite) and preserve the bulk-volume. Sr isotopic data suggest that 90 % of Ca in the spanish calcretes is allochthonous and related to atmospheric input. O and C isotopic compositions of the carbonates are compatible with soil temperatures and respiration rates during the beginning of the summer season. U-series disequilibrium in the carbonates suggests ages ranging between 40 to 270 ky, commensurate with the climatic cycle. The Sr isotopic signatures of spanish and moroccan calcretes are similar to those of the Quaternary marine carbonates. Assuming that only Ca-rich aerosols have been the source for calcretes of the studied regions, we propose that the wide continental plateaus exposed during glacial periods (low sea level) provided a major part of the calcic input to the soils. Semi-arid conditions of Spain and Morocco allowed the percolation and precipitation in the soil profiles to form calcretes. (author)

  20. Uranium isotopes in El hamraween harbour sediments

    International Nuclear Information System (INIS)

    Isotopes of uranium in marine sediments collected from El Hamraween harbour and Ras El-Bhar areas on the Egyptian coast of the Red Sea have been studied using radiochemical separation procedures and alpha-particle spectrometry. Activity concentrations of 238U, 235U, 234U were calculated. The activities observed indicating the enhancement of radioactivity level in El Hamraween harbor area due to the activities of phosphate shipment operation. Secular equilibrium between 234U and 238U was found in the analyzed samples. The average activity ratio of 235U/ 238U was close to the value 0.046 for uranium in nature

  1. Equilibrium reconstruction in the TCA/Br tokamak

    International Nuclear Information System (INIS)

    The accurate and rapid determination of the Magnetohydrodynamic (MHD) equilibrium configuration in tokamaks is a subject for the magnetic confinement of the plasma. With the knowledge of characteristic plasma MHD equilibrium parameters it is possible to control the plasma position during its formation using feed-back techniques. It is also necessary an on-line analysis between successive discharges to program external parameters for the subsequent discharges. In this work it is investigated the MHD equilibrium configuration reconstruction of the TCA/BR tokamak from external magnetic measurements, using a method that is able to fast determine the main parameters of discharge. The thesis has two parts. Firstly it is presented the development of an equilibrium code that solves de Grad-Shafranov equation for the TCA/BR tokamak geometry. Secondly it is presented the MHD equilibrium reconstruction process from external magnetic field and flux measurements using the Function Parametrization FP method. this method. This method is based on the statistical analysis of a database of simulated equilibrium configurations, with the goal of obtaining a simple relationship between the parameters that characterize the equilibrium and the measurements. The results from FP are compared with conventional methods. (author)

  2. Pan-Balti bränding - müüt või tegelikkus? / Joel Volkov

    Index Scriptorium Estoniae

    Volkov, Joel, 1972-

    2006-01-01

    Brändil pole kodumaad, on keel ja päritolumaa. Lokaalsed brändid valivad suhtlemiseks kohalikega nende kodukeele, globaalsed brändid harilikult inglise keele. Üks suuremaid ja tugevamaid lokaalsest süsteemist kasvanud Pan-Balti brände on Hansapank. Lisa: Sulev Vedler. Hansast võib saada Swedbank

  3. Isotope effects of samarium and ytterbium in the acetate/amalgam separation system

    International Nuclear Information System (INIS)

    The data on the fractionation of all stable isotopes of ytterbium and samarium in a Me(III) acetate/Me amalgam system were obtained. The light isotopes were preferentially fractionated into the amalgam phase. The single separation gains per mass difference were found to be in the range (4.90/17.8) x 10-4 for ytterbium and (2.2/3.8) x 10-4 for samarium. The divergence from the linear dependence between separation gains and isotope mass differences was observed and explained as the effect of nuclear field shift and nuclear spin effects. The maximum value of εu.m. was observed to be 17.8 x 10-4 for the lightest, neutron deficit isotope of ytterbium, 168Yb. The same value for the lightest isotope of samarium, 144Sm, with a magic number of neutrons (82), was close to the mean for other isotopes. (author)

  4. Mercury stable isotope biogeochemistry

    International Nuclear Information System (INIS)

    Full text: Methods for high precision measurement of natural Hg isotope ratios by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) have been developed recently by our group and allow the use of Hg isotopes to trace the biogeochemistry of Hg. Mercury has seven stable isotopes ranging from 196 to 204 amu.We have found that the isotopic composition of Hg varies by both mass dependent fractionation (MDF) and mass independent fractionation (MIF). Even and odd isotopes of Hg are fractionated by mass-dependent processes, whereas odd isotopes are also fractionated in a mass-independent way by photochemical reactions. Isotope ratios are measured relative to the NIST 3133 Hg standard reference material. MDF is reported as δ202Hg (± 0.08 %o, 2 SD) which is the difference in 202Hg/198Hg between a sample and NIST 3133 in permil (%o). MIF is reported as Δ 201Hg (± 0.05 %o, 2 SD), which is the difference in 201Hg/198Hg ratio in permil from what the 201Hg/198Hg ratio would be if the fractionation were entirely mass dependent. In this presentation we summarize the range of Hg isotopic compositions of a variety of environmental and geological materials. In previous work we described biotic and abiotic laboratory fractionation experiments demonstrating the range of mass dependent and mass independent fractionation caused by mercury redox transformations in the surface environment. Thus far we have found that MIF occurs during photochemical reduction of methyl-Hg and Hg2+ following a Rayleigh-like fractionation. Bacterial reduction causes Rayleigh-like MDF but no MIF. Coastal-marine and freshwater fish from North America have positive Δ 201Hg values (0.2 to > 3 %o) reflecting transfer of methyl-Hg into the food web after partial reduction by photochemical reactions. Most coals and the organic horizons of soils from North America have negative Δ 201Hg values (-0.1 to -0.4 %o), possibly reflecting the influence of Hg that was photochemically reduced in

  5. Identification of the bound residue composition derived from 14C-labeled chlorsulfuron in soil by using LC-MS and isotope tracing method

    Institute of Scientific and Technical Information of China (English)

    YE Qing-fu; WU Jian-min; SUN Jin-he

    2004-01-01

    A new method for extracting the bound residue(BR) derived from 14C-labeled chlorsulfuron in soils was developed, and the technique of combining LC-MS with isotope tracing method was subsequently applied to identify the composition of the 14 C-BR in a loamy Fluvent derived from marine deposit. The results showed that the 14C-[2-amino-4-methoxyl-6-methyl-1,3,5]-triazine, 14 C-[ 2-amino-4-hydroxyl-6-methyl-1,3,5]-triazine and 14 C-chlorsulfuron parent compound constituted the main composition of the 14 C-BR derived from 14 C-labeled chlorsulfuron in the soil. The radioactive ratio of three compounds accounted for 39.8 %, 35.4 % and 17.9 % of total recovered radioactivity, respectively. However, a small amount(3.6% of total recovered radioactivity) of the complex of 14 C-[ 2-amino-4-hydroxyl-6-methyl-1,3,5 ]-triazine might have existed in the 14 C-BR in association with an unknown soil substrate. 2-chlorobenzenesulfonamide was also detected to be one of the components of the BR. The results could well explain the mechanism of phytotoxicity caused by the BR derived from chlorsulfuron in soil. In addition, the mechanism of BR formation in soil was also discussed in details.

  6. Ensuring reliable medical isotope supply

    International Nuclear Information System (INIS)

    This paper describes the role of MDS Nordion and AECL in ensuring a reliable global supply of medical isotopes. The First part of the paper discusses the uses of medical isotopes, their importance to the medical community, and the benefits to patients of a secure supply of medical isotopes. The second part describes the role of the NRU reactor and the future role of the MAPLE reactors and New Processing Facility being commissioned at AECL's Chalk River Laboratories for production of medical isotopes to meet the world market demand for the next 40 years. MDS Nordion is the world's leading supplier of medical isotopes. These isotopes are used to conduct some 34,000 nuclear medicine procedures performed every day around the world, such as determining the severity of heart disease, the spread of cancer, and diagnosing brain disorders. These medical isotopes are currently produced primarily by AECL in the NRU reactor at Chalk River, Ontario, Canada. (author)

  7. Chromium isotope uptake in carbonates

    DEFF Research Database (Denmark)

    Rodler, Alexandra

    Chromium (Cr) is a redox sensitive element potentially capable of tracing fine-scale fluctuations of the oxygenation of Earth’s early surface environments and seawater. The Cr isotope composition of carbonates could perhaps be used as paleo-redox proxy to elucidate changes in the geological past....... Processes that potentially fractionate Cr isotopes, perhaps during deposition, burial and alteration need to be constrained.Previous studies have shown that Cr isotopes are fractionated during oxidative weathering on land, where heavy Cr isotopes are preferentially removed with Cr(VI) while residual soils...... retain an isotopically light Cr signature. Cr(VI) enriched in heavy Cr isotopes is then transported via river waters to the oceans and sequestered into marine sediments. Marine chemical sediments such asbanded iron formations and modern marine carbonates have proven useful in recording the Cr isotope...

  8. On the role of Brønsted catalysis in Pseudomonas fluorescens mannitol 2-dehydrogenase.

    Science.gov (United States)

    Klimacek, Mario; Kavanagh, Kathryn L; Wilson, David K; Nidetzky, Bernd

    2003-10-01

    X-ray structure of the Pseudomonas fluorescens mannitol 2-dehydrogenase ternary complex with NAD+ and D-mannitol suggests that Lys-295 provides catalytic base assistance to secondary alcohol group oxidation. We have replaced Lys-295 by site-directed mutagenesis with alanine or methionine and evaluated the catalytic significance of side-chain substitution by kinetic analysis of restoration of activity with external amines, and from pH and solvent isotope effects on the reaction catalysed by K295A (Lys-295-->Ala mutant). K295A and K295M (Lys-295-->Met mutants) show 3x10(4)- and 2x10(6)-fold lower turnover numbers respectively for D-mannitol oxidation (kcatO) at pH 10.0 than the wild-type. The second-order rate constant for non-covalent rescue of activity (kB) by free methylamine base is 31 M(-1) x s(-1) for K295A, but only 0.021 M(-1) x s(-1) for K295M. A Brønsted relationship of log kB (corrected for molecular size effects) and pKa of the external amine is linear (slope beta=0.66+/-0.16; r2=0.99) for K295A-catalysed D-mannitol oxidation at pH 10.0. The kcatO values of K295A in H2O and 2H2O are linearly dependent on [OL-] in the pL range 7.5-10.5 (where L is 1H or 2H). The solvent isotope effect on kcatO is 0.69. The time course of D-fructose reduction by K295A at pH 8.2 displays a pre-steady-state burst of NADH consumption. These data support a mechanism in which the epsilon -NH2 group of Lys-295 participates in an obligatory pH-dependent, pre-catalytic equilibrium which may control alcohol/alkoxide equilibration of enzyme-bound D-mannitol and activates the C2 atom for subsequent catalytic oxidation by NAD+. PMID:12826012

  9. Control strategies for laser separation of carbon isotopes

    Indian Academy of Sciences (India)

    V Parthasarathy; A K Nayak; S K Sarkar

    2002-12-01

    Laser isotope separation (LIS) by infrared laser chemistry of polyatomic molecules has come a long way since its discovery. The last decade has seen considerable efforts in scaling up of the process for light elements like carbon, oxygen and silicon. These efforts aim at ways to improve both the enrichment factor and the throughput. The achievement is quite significant especially for carbon isotope separation wherein macroscopic operating scales have been realized. We report our studies on the IR laser chemistry of two promising systems, viz. neat CF2HCl and CF3Br/Cl2. We have investigated conditions for optimizing the dissociation yield and selectivity using natural samples containing 1.1 % C-13. We also highlight our current efforts for scaling up the process. These include the design aspects of a photochemical reactor with multipass refocusing Herriott optics for efficient photon utilization, development of a cryogenic distillation set up and a preparative gas chromatograph for large scale separation/collection of the isotopically enriched photoproduct in the post-irradiation stage.

  10. Comparative study of α and β-ThBr4: structure and luminescence. Spectroscopy of U4+ in α-ThBr4

    International Nuclear Information System (INIS)

    UV absorption of β-ThBr4: presents a plain absorption front and for the same temperature the threshold energy has the same value than the threshold energy of excitation function and photocurrent peak. Emission intensity and lifetime decrease when temperature increases from 300 K to 400K (extinction temperature). Results are interpreted either by molecular orbital levels of the ThBr84- cluster or either by conduction and valence bands of the matrix above. Absorption and emission spectra of U4+ in α-ThBr4 (where U4+ has a S4 symmetry) between 300 K and 4.2 K allow indexation of 30 levels. Spectroscopic parameters are calculated in D2d and S4 symmetry. Comparison of these parameters with those of U4+ in β-ThBr4 and β-ThCl4 shows that crystal field force is practically the same in the three matrices but the structure transformation from β to α has more influence on Bqk than ligand change from Br- to Cl-. Owing to very low phonon energy, fluorescence spectra of U4+ is easy to observe in α-ThBr4 as it is in β-ThBr4 and ThCl4

  11. Separation and characterization of a radioresistant bacterium strain BR501 from radiation polluted soil

    International Nuclear Information System (INIS)

    Strain BR501, an extremely radioresistant bacterium isolated from the radioactive experimental soil. The optimal temperature for the growth of strain BR501 was 30 degree C. The UV radiation and γ-radiation survival curves showed the strain BR501 had highly radio-resistance. The strain was sensitive to Amp, Km, Rif, Cm and Tc. The 16S rDNA of the BR501 shared highly similarity to those of species in genus Deinococcus, especially to that of D.radiodurans r1(99%). Based on the 16S rDNA sequence analysis and the phenotype characteristics, the BR501 belongs to the evolution branch of Deinococcus and was designated Deinococcus sp. BR501. (authors)

  12. Compton suppressed LaBr3 detection system for use in nondestructive spent fuel assay

    Science.gov (United States)

    Bender, S.; Heidrich, B.; Ünlü, K.

    2015-06-01

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr3, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as 137Cs and 140La, due to scattered interactions in the detector, which allowed more spectral features to be resolved. There was a

  13. Compton suppressed LaBr3 detection system for use in nondestructive spent fuel assay

    International Nuclear Information System (INIS)

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr3, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as 137Cs and 140La, due to scattered interactions in the detector, which allowed more spectral features to be resolved. There was a

  14. Compton suppressed LaBr{sub 3} detection system for use in nondestructive spent fuel assay

    Energy Technology Data Exchange (ETDEWEB)

    Bender, S., E-mail: BenderESarah@gmail.com; Heidrich, B.; Ünlü, K.

    2015-06-01

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr{sub 3}, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as {sup 137}Cs and {sup 140}La, due to scattered interactions in the detector, which allowed more spectral features to be resolved

  15. Role of hexadecapole interaction in proton rich barium isotopes

    International Nuclear Information System (INIS)

    From the systematic analysis of the experimental data on proton rich barium isotopes, it is observed that nuclei in the region z ≥ 50 and N≤82 are the transitional nuclei as they show a shape transition from spherical to deformed shape. An interesting feature of the observed yrast spectra in barium isotopic mass chain is the systematic variation of E2+, E4+ and E6+ excitation energy states from 120Ba to 136Ba. It is observed that these states follow a systematic decreasing trend as move away from 136Ba towards 120Ba. The isotopes 120-128Ba can be taken to be quasi-deformed nuclei having E4+/E2+ ratio larger than 2.7. Based on the systematics of low-lying states and the experimental data of quadrupole moments and B(E2) transition probabilities, the stable barium isotopes range from the approximately spherical 138Ba to l30Ba which is close to the deformed 120-128Ba isotopes. The purpose of the paper is to determine the importance of octupole-octupole and hexadecapole- hexadecapole parts of the two body interaction in reproducing the observed nuclear structure properties of 120-136Ba isotopes

  16. Nuclear-spectroscopic measurements related to the design of 79Br, 81Br, and 87Rb solar-neutrino detectors

    International Nuclear Information System (INIS)

    Spectroscopic properties for low-lying states in 79Kr, 81Kr, and 87Sr were studied using the 78Kr(dvector,p)79Kr, 80Kr(dvector,p)81Kr, and 86Sr(dvector,p)87Sr reactions initiated by 11 MeV purely vector-polarized deuteron beams at Triangle Universities Nuclear Laboratory. A Distorted-Wave Born Approximation analysis of the resulting angular distributions of cross section and vector analyzing power enabled the assignment of spin-parity and extraction of neutron spectroscopic factors for 48 nuclear states. A technique for preparation of thin targets using ion implantation was developed as a means to improve spectrum resolution by reducing projectile straggling in the entrance and exit foils of gas cell targets. The neutrino capture process, sigma + (Z,A) → (Z + 1,A) + e-, is equivalent to inverse beta decay. In order to interpret the results of a solar neutrino experiment using 79Br, 81Br, or 87Rb, low-lying states in the daughter nuclei, 79Kr, 81Kr, and 87Sr, must be studied. In particular, the states in the daughter nuclei that have appropriate spin-parity to be populated by allowed inverse beta decay must be identified

  17. Stable isotopes in alpine ice cores: Do they record climate variability?

    International Nuclear Information System (INIS)

    Data from the national networks of stable isotopes in precipitation in Switzerland, Germany and Austria reveal distinct structures of climate variability within the Alpine region during the past three decades. To investigate the possibility of linking on longer time scales water isotopes and climate anomalies like the North Atlantic Oscillation (NAO), a high-resolution stable isotope record of an ice core from the Bernese Alps is examined with respect to the isotope information obtained from the precipitation data. Dating of the ice core is performed by annual layer counting of water isotopes, controlled by well known discrete time markers like reference horizons from nuclear weapon tests, the Chernobyl fall out, extreme events of Saharan dust falls and additionally compared to the seasonal behaviour of chemical constituents. After checking for post-depositional effects, the defined year-to-year isotope data sets are sub-divided into monthly composites according to the precipitation distribution of a high altitude precipitation station from the Swiss isotope network. For the last thirty years, the normalised data sets of the stable isotopes in the ice core show close similarities to the regional isotope distribution and the NAO index. Although the method has to be refined, an extension of the existing isotope record several centuries back in time to study climate variability seems to be feasible and reasonable. (author)

  18. BR-Explorer: An FCA-based algorithm for Information Retrieval

    OpenAIRE

    Messai, Nizar; Devignes, Marie-Dominique; Napoli, Amedeo; Smaïl-Tabbone, Malika

    2006-01-01

    In this paper we present BR-Explorer, an FCA-based algorithm that addresses the problem of retrieving the relevant objects for a given query. Initially, a formal context representing the relation between a set of objects and the corresponding set of attributes is given, and the associated concept lattice is built. BR-Explorer starts by generating a formal concept representing the considered query, and classifies this query concept in the concept lattice. Then, BR-Explorer tries to locate the ...

  19. The BR1 research facilities to calibrate fuzzy logic technology for nuclear reactor control

    International Nuclear Information System (INIS)

    During the last three decades SCK-CEN has participated in various international programmes using the BR1 (Belgian Reactor 1) facilities for various research and calibration purposes. The BR1 has proved to be an excellent for calibration and validation of techniques, integral nuclear data validation, activation analysis, characterisation of materials by neutron transmission, and physics experiments. Moreover, the knowledge, built up at BR1 has lead to the best calibration conditions for applying fuzzy logic control (FLC) for nuclear reactor control

  20. Effects of carbon black distribution on the electrical properties of Br/Epdm compounds

    International Nuclear Information System (INIS)

    The correlations between mechanical and electrical properties of butadiene/ethylene propylene diene terpolymer (BR/EPDM) and the distribution of carbon black levels are studied. It was found that the BR phase in the blends, compared to the EPDM phase, is more preferential for the used type of carbon black, probably because the lower viscosity and lower polarity of the BR phase. Tensile strength increases with an increase of carbon black. Possible reasons for these results are discussed

  1. Babcock and Wilcox BR-100 100-ton rail/barge spent fuel shipping cask

    International Nuclear Information System (INIS)

    This Preliminary Design Report (PDR) provides a detailed description of the design, analyses, and testing programs for the BR-100 cask. The BR-100 is a Type B(U) cask designed for transport by rail or barge. This report presents the preliminary analyses and tests which have been performed for the BR-100 and outlines the confirmatory analyses and tests which will be performed

  2. Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

    Directory of Open Access Journals (Sweden)

    J. Liao

    2011-09-01

    Full Text Available A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission was examination of bromine photochemistry in the spring time, high latitude troposphere based on aircraft and satellite measurements of BrO and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometry (CIMS instrument to measure BrO and a mist chamber (MC to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2, hypobromous acid (HOBr, bromine oxide (BrO, and hydrogen bromide (HBr as soluble bromide (Br was 0.9±0.1, 1.06±0.30, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.98; intercept = −3.5 pptv between modeled and observed soluble bromide, when BrO was above detection limit (>2 pptv under unpolluted conditions (NO < 100 pptv, indicates that the CIMS BrO measurements were consistent with the MC soluble bromide. Tropospheric BrO vertical column densities (BROTROPVCD derived from CIMS BrO observations compare well with BROTROPVCD from OMI on 17 April 2008.

  3. Babcock and Wilcox BR-100 100-ton rail/barge spent fuel shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-02-01

    This Preliminary Design Report (PDR) provides a detailed description of the design, analyses, and testing programs for the BR-100 cask. The BR-100 is a Type B(U) cask designed for transport by rail or barge. This report presents the preliminary analyses and tests which have been performed for the BR-100 and outlines the confirmatory analyses and tests which will be performed.

  4. New isotope 265Bh

    International Nuclear Information System (INIS)

    A new isotope 265Bh was produced and identified at the Sector Focus Cyclotron of the Heavy Ion Research Facility in Lanzhou. This experiment was performed via the reaction of an 243Am target with 168 MeV 26Mg ions. Identification was made by observation of correlated α -particle decays between the new isotope 265Bh and its 261Db and 257Lr daughter nuclei using a set of rotating-wheels system. A total of 8 correlated decay events of 265Bh and 4 decay events of 264Bh were observed. 265Bh decays with a 0.94 -0.31+0.70 s half-life by emission of α-particles with an average energy of 9.24 ±0.05 MeV. The half-life and α decay energy of 265Bh from this experiment are in agreement with theoretical predictions. (orig.)

  5. Cyclotrons for isotope production

    International Nuclear Information System (INIS)

    Cyclotrons continue to be efficient accelerators for radioisotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  6. Isotope enrichment systems

    International Nuclear Information System (INIS)

    This patent provides a process for concentrating the heavy isotope of at least one element of the class consisting of hydrogen and oxygen by the dual temperature exchange of the heavy and light isotopes of the element between two separable fluids containing said element. One of the fluids is in the gaseous phase and the other in the liquid phase. The liquid phase is provided as a solution consisting essentially in minor molar proportion, of water and in major molar proportion, of material selected from the class consisting of the water miscible organic hydroxy and/or carboxy compounds which have a ratio of carbon atoms to their alcoholic and acidic hydroxyl groups not greater than 2

  7. Climatic changes and isotopic content along the River Nile valley

    International Nuclear Information System (INIS)

    , Nile surface water samples have been collected at Cairo throughout the period 8/11/1994 to 6/7/1996, beginning immediately following a heavy storm event in the beginning of November 1994 which deposited precipitation across Egypt of isotopic composition close to -44 per mille in ΠD and -6.5 in δ18O. The isotopic content of Nile water samples fluctuated and slightly changing with time. The conventional relation between δ18O and δD in precipitation for the region is given by δD=9.97δ 18O-4.15. The variation of the bomb-tritium response of the Nile has been reconstructed by using a model calibrated using measurements taken in the Nile basin. The results show that pre-bomb tritium content in the Nile was likely close to 5 T.U which peaked in the early 1960s at about 500 T.U. At present, the tritium level content of the Nile is about 9 T.U. (author)

  8. Isotopic hydrodynamic of the aquifer systems Jaruco and Aguacate, Cuba

    International Nuclear Information System (INIS)

    An isotopic dispersive model is applied to the Jaruco and Aguacate karstic groundwater basins of Western Cuba. The best fit of the model was validated with stable (18O and 2H) and radioactive (3H) isotopes. Modeling showed an aquifer stratification in two basic levels with turnover times of three month to upper level and close to 100 years to the lower level. The last one mainly supplies the base flow of the Ojo de agua and Bello springs and therefore, controls the dry season exploitation yields of the aqueducts of El Gato and Bello. Model results introduces an important constraint in the exploitation of groundwater resource of both aquifer systems

  9. Variation in the flowering time orthologs BrFLC and BrSOC1 in a natural population of Brassica rapa.

    Science.gov (United States)

    Franks, Steven J; Perez-Sweeney, Beatriz; Strahl, Maya; Nowogrodzki, Anna; Weber, Jennifer J; Lalchan, Rebecca; Jordan, Kevin P; Litt, Amy

    2015-01-01

    Understanding the genetic basis of natural phenotypic variation is of great importance, particularly since selection can act on this variation to cause evolution. We examined expression and allelic variation in candidate flowering time loci in Brassica rapa plants derived from a natural population and showing a broad range in the timing of first flowering. The loci of interest were orthologs of the Arabidopsis genes FLC and SOC1 (BrFLC and BrSOC1, respectively), which in Arabidopsis play a central role in the flowering time regulatory network, with FLC repressing and SOC1 promoting flowering. In B. rapa, there are four copies of FLC and three of SOC1. Plants were grown in controlled conditions in the lab. Comparisons were made between plants that flowered the earliest and latest, with the difference in average flowering time between these groups ∼30 days. As expected, we found that total expression of BrSOC1 paralogs was significantly greater in early than in late flowering plants. Paralog-specific primers showed that expression was greater in early flowering plants in the BrSOC1 paralogs Br004928, Br00393 and Br009324, although the difference was not significant in Br009324. Thus expression of at least 2 of the 3 BrSOC1 orthologs is consistent with their predicted role in flowering time in this natural population. Sequences of the promoter regions of the BrSOC1 orthologs were variable, but there was no association between allelic variation at these loci and flowering time variation. For the BrFLC orthologs, expression varied over time, but did not differ between the early and late flowering plants. The coding regions, promoter regions and introns of these genes were generally invariant. Thus the BrFLC orthologs do not appear to influence flowering time in this population. Overall, the results suggest that even for a trait like flowering time that is controlled by a very well described genetic regulatory network, understanding the underlying genetic basis of

  10. Solvent dependent branching between C-I and C-Br bond cleavage following 266 nm excitation of CH2BrI

    International Nuclear Information System (INIS)

    It is well known that ultraviolet photoexcitation of halomethanes results in halogen-carbon bond cleavage. Each halogen-carbon bond has a dominant ultraviolet (UV) absorption that promotes an electron from a nonbonding halogen orbital (nX) to a carbon-halogen antibonding orbital (σ*C-X). UV absorption into specific transitions in the gas phase results primarily in selective cleavage of the corresponding carbon-halogen bond. In the present work, broadband ultrafast UV-visible transient absorption studies of CH2BrI reveal a more complex photochemistry in solution. Transient absorption spectra are reported spanning the range from 275 nm to 750 nm and 300 fs to 3 ns following excitation of CH2BrI at 266 nm in acetonitrile, 2-butanol, and cyclohexane. Channels involving formation of CH2Br + I radical pairs, iso-CH2Br-I, and iso-CH2I-Br are identified. The solvent environment has a significant influence on the branching ratios, and on the formation and stability of iso-CH2Br-I. Both iso-CH2Br-I and iso-CH2I-Br are observed in cyclohexane with a ratio of ∼2.8:1. In acetonitrile this ratio is 7:1 or larger. The observation of formation of iso-CH2I-Br photoproduct as well as iso-CH2Br-I following 266 nm excitation is a novel result that suggests complexity in the dissociation mechanism. We also report a solvent and concentration dependent lifetime of iso-CH2Br-I. At low concentrations the lifetime is >4 ns in acetonitrile, 1.9 ns in 2-butanol and ∼1.4 ns in cyclohexane. These lifetimes decrease with higher initial concentrations of CH2BrI. The concentration dependence highlights the role that intermolecular interactions can play in the quenching of unstable isomers of dihalomethanes

  11. Dual isotope assays

    International Nuclear Information System (INIS)

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  12. Carbon isotopes in photosynthesis

    International Nuclear Information System (INIS)

    The efficiency of photosynthesis continues to interest biochemists, biologists, and plant physiologists. Scientists interested in CO2 uptake are concerned about the extent to which the uptake rate is limited by such factors as stomatal diffusion and the chemistry of the CO2 absorption process. The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake

  13. Photochemical separation of isotopes

    International Nuclear Information System (INIS)

    A process for the photochemical separation of carbon 13 and oxygen 18 uses 123.54 nm resonance radiation from a gaseous discharge containing Kr and an inert gas to excite selectively 13C16O, 12C18O, or both with no significant excitation of 12C16O. The excited molecules react with ground state CO to yield CO2 and C3O2. The isotopically-enriched products are removed from the reactants by condensation

  14. Isotopes and agriculture

    International Nuclear Information System (INIS)

    The agriculture is defined as the art of desturbing the ecosystems in economical terms with the minimum of irreversible damage. Man survival in the biosphere will depend on its ability of using four technologies - mechanization, fertilizers, irrigation and pest disease control. The isotopes are usefull to establish means of producing more food and to preserve it; and clains of unbearable damages to the ecosystems caused by fertilizers and pesticides are not true, are presented. (author)

  15. Stable isotope laser spectroscopy

    Science.gov (United States)

    Becker, J. F.; Yaldaei, Ramil; Mckay, Christopher P.

    1989-01-01

    Recent advances in semiconductor laser technology have produced a reliable lightweight device ideally suited for a spacecraft high resolution molecular spectrometer. Lead-salt tunable diode lasers (TDL) emit in several spectral modes, each with a very narrow linewidth of -0.0003/cm. This spectral resolution is much narrower than typical Doppler broadened molecular linewidths in the mid-IR range. Thus it is possible to detect individual rotational lines within the vibrational band and measure their intensity, which can be used to determine gas concentration. The narrow spectral lines of any impurity gas tend to lie between the narrow lines of the gas of interest. This represents a major advantage over the accepted gas chromatograph mass spectrometer (GCMS) technique for measuring gas concentrations and isotope ratios. The careful and extensive gas purification procedures required to remove impurities for reliable GCMS measurements will not be required for an IR laser gas analysis. The infrared laser gas analysis technique is being developed to measure stable isotopic ratios of gases such as CO2, CH4, N2O, and NH3. This will eventually lead to development of instruments capable of in situ istopic measurements on planets such as Mars. The carbon (C-12, C-13) isotope ratio is indicative of the type of carbon fixation mechanisms (e.g., photosynthesis, respiration) in operation on a planet, while the nitrogen (N-14, N-15) isotope ratio can probably be used to date nitrogen-bearing Martian samples. The absorbance ratio of two adjacent lines of CO2 in the 2300/cm (4.3 micron) region of the spectrum was measured. The precision of the measurement is presently better than 1 percent and significant improvement is anticipated as rapid sweep-integration techniques and computer controlled data acquistion capabilities are incorporated.

  16. The isotope correlation experiment

    International Nuclear Information System (INIS)

    The ESARDA working group on Isotopic Correlation Techniques, ICT and Reprocessing Input Analysis performed an Isotope Correlation Experiment, ICE with the aim to check the feasibility of the new technique. Ten input batches of the reprocessing of the KWO fuel at the WAK plant were analysed by 4 laboratories. All information to compare ICT with the gravimetric and volumetric methods was available. ICT combined with simplified reactor physics calculation was included. The main objectives of the statistical data evaluation were detection of outliers, the estimation of random errors and of systematic errors of the measurements performed by the 4 laboratories. Different methods for outlier detection, analysis of variances, Grubbs' analysis for the constant-bias model and Jaech's non-constant-bias model were applied. Some of the results of the statistical analysis may seem inconsistent which is due to the following reasons. For the statistical evaluations isotope abundance data (weight percent) as well as nuclear concentration data (atoms/initial metal atoms) were subjected to different outlier criteria before being used for further statistical evaluations. None of the four data evaluation groups performed a complete statistical data analysis which would render possible a comparison of the different methods applied since no commonly agreed statistical evaluation procedure existed. The results prove that ICT is as accurate as conventional techniques which have to rely on costly mass spectrometric isotope dilution analysis. The potential of outlier detection by ICT on the basis of the results from a single laboratory is as good as outlier detection by costly interlaboratory comparison. The application of fission product or Cm-244 correlations would be more timely than remeasurements at safeguards laboratories

  17. Carbon-13 kinetic isotope effects in the decarbonylation of lactic acid of natural isotopic composition in phosphoric acid medium

    International Nuclear Information System (INIS)

    The 13C kinetic isotope effect fractionation in the decarbonylation of lactic acid (LA) of natural isotopic composition by concentrated phosphoric acids (PA) and by 85% H3PO4 has been studied in the temperature interval of 60-150 deg C. The values of the 13C(1) isotope effects in the decarbonylation of lactic acid in 100% H3PO4, in pyrophosphoric acid and in more concentrated phosphoric acids are intermediate between the values calculated assuming that the C(1)-OH bond is broken in the rate-controlling step of dehydration and those calculated for rupture of the carbon-carbon bond in the transition state. In the temperature interval of 90-130 deg C the experimental 13C fractionation factors determined in concentrated PA approach quite closely the 13C fractionation corresponding to C(2)-C(1) bond scission. The 13C(1) kinetic isotope effects in the decarbonylation of LA in 85% orthophosphoric acid in the temperature range of 110-150 deg C coincide with the 13C isotope effects calculated assuming that the frequency corresponding to the C(1)-OH vibration is lost in the transition state of decarbonylation. A change of the mechanism of decarbonylation of LA in going from concentrated PA medium to 85% H3PO4 has been suggested. A possible secondary 18O and a primary18O kinetic isotope effect in decarbonylation of lactic acid in phosphoric acids media have been discussed, too. (author) 21 refs.; 3 tabs

  18. Suostuttelevan markkinointiviestinnän metodit brändipersoonallisuuden luomiseksi Twitter-kontekstissa

    OpenAIRE

    Laitinen, Timo

    2014-01-01

    Tutkielman tutkimusongelma on määritelty kolmen käsitteen kautta: markkinointiviestintä, brändipersoonallisuus ja suostuttelu. Tutkimusongelman ytimenä on brändin mahdollisuus hyödyntää suostuttelua markkinointiviestinnässään, luodakseen itsestään tarkoituksenmukaisen brändipersoonallisuuden. Tutkimusmenetelmänä on laadullinen sisällönanalyysi ja aineistona toimii kahdeksan kansainvälisen brändin Twitter-markkinointiviestintä. Suostuttelua tut-kitaan harkinnan todennäköisyyden teorian avulla ...

  19. Kuluttaja-asiakkaiden mielikuva Concept.10-brändistä

    OpenAIRE

    Väisänen, Janna-Mari

    2011-01-01

    Tutkimuksen tavoitteena on selvittää, millainen käsitys Concept.10:n kuluttaja-asiakkailla on brändin eri osa-alueista ja millaisia mielleyhtymiä brändin mainonta, nimi, tunnus ja slogan herättävät. Näillä tekijöillä on vaikutusta kokonaismielikuvan syntymiseen brändistä. Tutkimusongelmana on, millainen mielikuva kuluttaja-asiakkailla on Concept.10-brändistä. Concept.10 toimii yhteisenä markkinointinimenä Mikkelin Puhelin Oyj:n omistamille yhtiöille ja niiden palveluille. Teoreettisessa v...

  20. Validation of Aura Microwave Limb Sounder BrO observations in the stratosphere

    OpenAIRE

    J. Kovalenko, L.; L. Livesey, N.; J. Salawitch, R.; Camy-Peyret, C.; P. Chipperfield, M.; E. Cofield, R.; Dorf, M.; J. Drouin, B.; L. Froidevaux; Fuller, R. A.; Goutail, Florence; F. Jarnot, R.; Jucks, K.; W. Knosp, B.; Lambert, A.

    2007-01-01

    Validation of stratospheric BrO vertical profiles obtained by the Microwave Limb Sounder (MLS) on the Aura satellite is discussed. MLS BrO measurements are compared with expectations of its latitudinal and seasonal dependence, as well as with more localized balloon-borne measurements of BrO. We describe the expected precision and systematic errors of the version 2.2 retrieval and show that scientific studies using MLS BrO vertical profiles require extensive averaging to increase the signal-to...

  1. Observations of BrO and its vertical distribution during surface ozone depletion at Alert

    Energy Technology Data Exchange (ETDEWEB)

    Hoeinninger, G.; Platt, U. [Universitaet Heidelberg (Germany). Inst. fuer Umweltphysik

    2002-06-01

    During the ALERT2000 polar sunrise experiment at Alert, Nunavut, Canada, we performed measurements of boundary layer bromine oxide radicals (BrO) by differential optical absorption spectroscopy (DOAS) using scattered sunlight in the spectral range from 320 to 400 nm. For the first time the Multi-Axis-(MAX)-DOAS method was applied to derive vertical profile information of BrO. BrO was observed at slant column densities (SCD) of up to 10{sup 15} molecules/cm{sup 2} during a 10-day period of complete surface ozone depletion. The largest BrO column densities were found by observing scattered sunlight from 5{sup o} above the horizon, and SCDs were decreasing with increasing elevation angles of the light-receiving telescope. For zenith scattered light the lowest absorption was recorded. Radiative transfer modelling and the calculation of air mass factors show that in most cases the bulk of the observed BrO was present in a layer of 1{+-}0.5 km thickness above the surface (in the boundary layer). The inferred extent of the BrO layer agrees very well with the observed height of the ozone depletion layer (Bottenheim et al., Atmos. Environ., 2002) from ozone sonde data. Assuming that BrO layer is well-mixed, volume mixing ratios reached levels of 20-30 ppt BrO. These values are consistent with previous measurements of BrO during low ozone events in the Arctic boundary layer. (Author)

  2. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  3. 2014, l’année brésilienne

    OpenAIRE

    Dabène,Olivier

    2014-01-01

    Dilma Rousseff pourrait être élue personnalité de l’année 2014 en Amérique latine. La présidente du Brésil a réussi à organiser une Coupe du monde de football exemplaire, apportant un démenti cinglant aux oiseaux de mauvais augure qui ont accaparé les médias pendant des mois. Très impopulaire en début d’année, empêtrée dans un scandale de corruption et handicapée par une récession économique, elle est ensuite parvenue à offrir au Parti des travailleurs (PT) une quatrième victoire ...

  4. Collisional trap losses of cold, magnetically-trapped Br atoms

    CERN Document Server

    Lam, J; Softley, T P

    2014-01-01

    Near-threshold photodissociation of Br$_2$ from a supersonic beam produces slow bromine atoms that are trapped in the magnetic field minimum formed between two opposing permanent magnets. Here, we quantify the dominant trap loss rate due to collisions with two sources of residual gas: the background limited by the vacuum chamber base pressure, and the carrier gas during the supersonic gas pulse. The loss rate due to collisions with residual Ar in the background follows pseudo first-order kinetics, and the bimolecular rate coefficient for collisional loss from the trap is determined by measurement of this rate as a function of the background Ar pressure. This rate coefficient is smaller than the total elastic collision rate coefficient, as it only samples those collisions that lead to trap loss, and is determined to be $\\langle\

  5. Kuluttajat brändisisältöjen parissa

    OpenAIRE

    Puolakka, Patricia; Sjöblom, Siiri

    2015-01-01

    Tämän opinnäytetyön aihe on sisältömarkkinoinnin purevuus. Sisältömarkkinointi on kovin laaja käsite, jonka vuoksi aihe rajattiin siihen, mitkä ominaisuudet tekevät sisältömarkkinoinnista tehokkaan ja minkälaiset sisällöt erottuvat miljoonien viestien seasta digitaalisessa ympäristössä. Tarkoituksena on ymmärtää, mitkä piirteet tekevät brändien sisältömarkkinoinnista niin tehokasta ja vetävää, että kuluttajat viettävät sen parissa aikaa sekä samalla rakentaa ymmärrystä kuluttajakäyttäytymises...

  6. Evaluation of theoretical conversion coefficients using BrIcc

    International Nuclear Information System (INIS)

    A new internal conversion coefficient database, BrIcc has been developed which integrates a number of tabulations on internal conversion electron (ICC) and electron-positron pair conversion coefficients (IPC), as well as Ω(E0) electronic factors. A critical review of general formulae and procedures to evaluate theoretical ICC and IPC values are presented, including the treatment of uncertainties in transition energy and mixing ratio in accordance with the Evaluated Nuclear Structure Data File. The default ICC table, based on the Dirac-Fock calculations using the so called 'Frozen Orbital' approximation, takes into account the effect of atomic vacancies created in the conversion process. The table has been calculated for all atomic shells and to cover transition energies of 1-6000 keV and atomic numbers of Z=5-110. The software tools presented here are well suited for basic nuclear structure research and for a range of applications

  7. ISO Observations of the dusty quasar BR1202-0725

    CERN Document Server

    Leech, K J; Metcalfe, L

    2001-01-01

    We present mid- and far-IR photometry of the high-redshift (z=4.69) dusty quasar BR1202-0725. The quasar was detected in the near-IR, at a flux level (0.7+/-0.2 mJy) consistent with an average Radio-Quiet Quasar at it's redshift. Only upper limits for the emission were obtained in the far-IR. These upper limits, when combined with data from ground-based telescopes, are the first direct evidence for a turn-over in the far-IR emission and hence confirm that a black-body dominates the SED at FIR wavelengths. This black-body is most probably cool dust, constrained to have a temperature below 80K, for a beta of 1.5.

  8. Estimering af brændstofforbrug vha. GPS Data

    DEFF Research Database (Denmark)

    Andersen, Ove; Lahrmann, Harry; Torp, Kristian

    2010-01-01

    Det er simpelt og billigt at opsamle GPS målinger fra køretøjer. Når større mængder GPS data indsamles fra et passende antal køretøjer kan dataen bruges til at beregne f.eks. køretider. Det er ligeledes muligt ud fra GPS data at estimere miljøindikatorer så som, hvor aggressivt kører bilister og er...... der nogle vejstrækninger, der har en højere (negativ) miljø påvirkning end andre? I denne artikel præsenterer et forsøg, hvor GPS data anvendes til at estimere brændstofforbruget ved en enkelt tur og for vejnettet generelt. Dette gøres ved at opbygge en database med GPS data. Ud fra disse data gives...

  9. Oxygen isotope fractionation during N2O production by soil denitrification

    Science.gov (United States)

    Lewicka-Szczebak, Dominika; Dyckmans, Jens; Kaiser, Jan; Marca, Alina; Augustin, Jürgen; Well, Reinhard

    2016-02-01

    The isotopic composition of soil-derived N2O can help differentiate between N2O production pathways and estimate the fraction of N2O reduced to N2. Until now, δ18O of N2O has been rarely used in the interpretation of N2O isotopic signatures because of the rather complex oxygen isotope fractionations during N2O production by denitrification. The latter process involves nitrate reduction mediated through the following three enzymes: nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR). Each step removes one oxygen atom as water (H2O), which gives rise to a branching isotope effect. Moreover, denitrification intermediates may partially or fully exchange oxygen isotopes with ambient water, which is associated with an exchange isotope effect. The main objective of this study was to decipher the mechanism of oxygen isotope fractionation during N2O production by soil denitrification and, in particular, to investigate the relationship between the extent of oxygen isotope exchange with soil water and the δ18O values of the produced N2O. In our soil incubation experiments Δ17O isotope tracing was applied for the first time to simultaneously determine the extent of oxygen isotope exchange and any associated oxygen isotope effect. We found that N2O formation in static anoxic incubation experiments was typically associated with oxygen isotope exchange close to 100 % and a stable difference between the 18O / 16O ratio of soil water and the N2O product of δ18O(N2O / H2O) = (17.5 ± 1.2) ‰. However, flow-through experiments gave lower oxygen isotope exchange down to 56 % and a higher δ18O(N2O / H2O) of up to 37 ‰. The extent of isotope exchange and δ18O(N2O / H2O) showed a significant correlation (R2 = 0.70, p fractionation model was used to test various scenarios with different magnitudes of branching isotope effects at different steps in the reduction process. The results suggest that during denitrification, isotope exchange occurs prior to

  10. Regulation of arsenite oxidation by the phosphate two-component system PhoBR in Halomonas sp. HAL1.

    Science.gov (United States)

    Chen, Fang; Cao, Yajing; Wei, Sha; Li, Yanzhi; Li, Xiangyang; Wang, Qian; Wang, Gejiao

    2015-01-01

    Previously, the expression of arsenite [As(III)] oxidase genes aioBA was reported to be regulated by a three-component regulatory system, AioXSR, in a number of As(III)-oxidizing bacterial strains. However, the regulation mechanism is still unknown when aioXSR genes are absent in some As(III)-oxidizing bacterial genomes, such as in Halomonas sp. HAL1. In this study, transposon mutagenesis and gene knock-out mutation were performed, and two mutants, HAL1-phoR 931 and HAL1-▵phoB, were obtained in strain HAL1. The phoR and phoB constitute a two-component system which is responsible for phosphate (Pi) acquisition and assimilation. Both of the mutants showed negative As(III)-oxidation phenotypes in low Pi condition (0.1 mM) but not under normal Pi condition (1 mM). The phoBR complementation strain HAL1-▵phoB-C reversed the mutants' null phenotypes back to wild type status. Meanwhile, lacZ reporter fusions using pCM-lacZ showed that the expression of phoBR and aioBA were both induced by As(III) but were not induced in HAL1-phoR 931 and HAL1-▵phoB. Using 15 consensus Pho box sequences, a putative Pho box was found in the aioBA regulation region. PhoB was able to bind to the putative Pho box in vivo (bacterial one-hybrid detection) and in vitro (electrophoretic mobility gel shift assay), and an 18-bp binding sequence containing nine conserved bases were determined. This study provided the evidence that PhoBR regulates the expression of aioBA in Halomonas sp. HAL1 under low Pi condition. The new regulation model further implies the close metabolic connection between As and Pi. PMID:26441863

  11. Regulation of Arsenite Oxidation by the Phosphate Two-Component System PhoBR in Halomonas sp. HAL1

    Directory of Open Access Journals (Sweden)

    Fang eChen

    2015-09-01

    Full Text Available Previously, the expression of arsenite [As(III] oxidase genes aioBA was reported to be regulated by a three-component regulatory system, AioXSR, in a number of As(III-oxidizing bacterial strains. However, the regulation mechanism is still unknown when aioXSR genes are absent in some As(III-oxidizing bacterial genomes, such as in Halomonas sp. HAL1. In this study, transposon mutagenesis and gene knock-out mutation were performed, and two mutants, HAL1-phoR931 and HAL1-△phoB, were obtained in strain HAL1. The phoR and phoB constitute a two-component system which is responsible for phosphate (Pi acquisition and assimilation. Both of the mutants showed negative As(III-oxidation phenotypes in low Pi condition (0.1 mM but not under normal Pi condition (1 mM. The phoBR complementation strain HAL1-△phoB-C reversed the mutants’ null phenotypes back to wild type status. Meanwhile, lacZ reporter fusions using pCM-lacZ showed that the expression of phoBR and aioBA were both induced by As(III but were not induced in HAL1-phoR931 and HAL1-△phoB. Using 15 consensus Pho box sequences, a putative Pho box was found in the aioBA regulation region. PhoB was able to bind to the putative Pho box in vivo (bacterial one-hybrid detection and in vitro (electrophoretic mobility gel shift assay, and an 18-bp binding sequence containing nine conserved bases were determined. This study provided the evidence that PhoBR regulates the expression of aioBA in Halomonas sp. HAL1 under low Pi condition. The new regulation model further implies the close metabolic connection between As and Pi.

  12. Thermal, dielectric properties and vibrational spectra of [ n-C 4H 9NH 3] 2[BiBr 5] crystal

    Science.gov (United States)

    Tarasiewicz, J.; Jakubas, R.; Baran, J.; Pietraszko, A.

    2006-07-01

    [ n-C 4H 9NH 3] 2[BiBr 5] exhibits five solid-solid structural phase transitions; at 309 (1st order), 291 (1st), 240 (1st), 219 (close to 2nd) and at 166 K (1st). The phase transitions at 291 and 240 K are accompanied by distinct dielectric anomalies. The dielectric relaxation process was found to appear over the phases (III) and (I). The infrared spectra for [ n-C 4H 9NH 3] 2[BiBr 5] were measured in the region of the internal vibration of the n-butylammonium cation (4000-400 cm -1) between 12 and 320 K. The temperature changes of wavenumbers and of a width for many of the internal modes of the n-butylammonium clearly indicate the contribution of the organic sublattice to the phase transition mechanism.

  13. Lithium isotope fractionation in the Ganges-Brahmaputra floodplain and implications for groundwater impact on seawater isotopic composition

    Science.gov (United States)

    Bagard, Marie-Laure; West, A. Joshua; Newman, Karla; Basu, Asish R.

    2015-12-01

    Lithium isotopes are a promising proxy for reconstructing past weathering processes, but unraveling the seawater record requires a comprehensive understanding of the magnitude and isotopic composition of Li fluxes to the oceans, and of how these change over time. Little information is available on the role of floodplain sediments and groundwater systems in setting the Li isotope signature of the dissolved flux delivered from the continents to the oceans. Here we investigate the Li dissolved fluxes of river waters and groundwaters in the Ganges-Brahmaputra floodplain. The data suggest that a maximum of 3.1 ×108 and 1.5 ×108 moles Li/yr are carried to the Bay of Bengal by Ganges-Brahmaputra rivers and groundwaters, respectively. The riverine flux has a significantly heavier Li isotope composition (average δ7Li: 26‰) than the groundwater flux (average δ7Li: 16‰) and increases downstream across the floodplain. δ7Li in both river waters and shallow groundwater can be explained by Li scavenging by Quaternary floodplain sediments following a Rayleigh fractionation process, with preferential removal of 6Li. On the other hand, deep groundwaters (>40 m) contributing to submarine groundwater discharge to the Bay of Bengal are enriched in 6Li at depth, likely due to the dissolution of floodplain sediments releasing Li with a light isotope composition. Similarly low δ7Li has been reported in other large sedimentary aquifers. The deep groundwater values are close to the average isotope composition of the global Li inputs to the ocean (∼15‰), so groundwater submarine discharge has only a minor influence on the assessment of the modern Li isotope budget of the ocean. Our analysis further suggests that groundwater discharge of Li has probably played at most a small and secondary role in past changes in the isotope composition of the total continental flux of Li to the ocean.

  14. Ultraviolet Spectroscopy of the Massive LMC Multiple Systems Sk-6718 (Br+.1667em5 and HD+.1667em36402 (Br+.1667em31

    Directory of Open Access Journals (Sweden)

    G. Koenigsberger

    2003-01-01

    Full Text Available Reportamos los resultados de observaciones en el UV de dos sistemas binarios cercanos, ubicados en la Nube Mayor de Magallanes, Br 5 y Br 31. Detectamos variabilidad espectral en Br 31 producida por eclipses atmosféricos, así como variaciones en la velocidad radial de algunas de sus líneas, con el periodo de 3.033 días. El espectro UV de este sistema es consistente con la presencia de 3 estrellas calientes en el sistema. En contraste, no podemos confirmar la presencia de más de 2 estrellas calientes en el sistema Br 5, y la debilidad de Si IV 1400 contradice la presencia de una supergigante O-tardía o B-temprana. Detectamos variaciones de velocidad radial consistentes con el movimiento orbital de la componente O3 If*.

  15. Therapeutic use of radioactive isotopes

    CERN Document Server

    Caroline Duc

    2013-01-01

    In December, researchers from ISOLDE-CERN, the Paul Scherrer Institute (PSI) and the Institut Laue-Langevin (ILL) published the results of an in vivo study which successfully proved the effectiveness of four terbium isotopes for diagnosing and treating cancerous tumours.   Four terbium isotopes suitable for clinical purposes. “ISOLDE is the only installation capable of supplying terbium isotopes of such purity and intensity in the case of three out of the four types used in this study,” explains Karl Johnson, a physicist at ISOLDE.  “Producing over a thousand different isotopes, our equipment offers the widest choice of isotopes in the world!” Initially intended for fundamental physics research, ISOLDE has diversified its activities over time to invest in various projects in the materials science, biochemistry and nuclear medicine fields. The proof-of-concept study has confirmed that the four terbium isotopes 149Tb, 152Tb, 155Tb produ...

  16. Laser Ablation Molecular Isotopic Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Richard E., E-mail: rerusso@lbl.gov [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Applied Spectra, Inc., 46661 Fremont Boulevard, Fremont, CA 94538 (United States); Bol' shakov, Alexander A. [Applied Spectra, Inc., 46661 Fremont Boulevard, Fremont, CA 94538 (United States); Mao Xianglei [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); McKay, Christopher P. [NASA-Ames Research Center, Moffett Field, CA 94035 (United States); Perry, Dale L.; Sorkhabi, Osman [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)

    2011-02-15

    A new method of performing optical isotopic analysis of condensed samples in ambient air and at ambient pressure has been developed: Laser Ablation Molecular Isotopic Spectrometry (LAMIS). The technique uses radiative transitions from molecular species either directly vaporized from a sample or formed by associative mechanisms of atoms or ions in a laser ablation plume. This method is an advanced modification of a known atomic emission technique called laser-induced breakdown spectroscopy (LIBS). The new method - LAMIS - can determine not only chemical composition but also isotopic ratios of elements in the sample. Isotopic measurements are enabled by significantly larger isotopic shifts found in molecular spectra relative to atomic spectra. Analysis can be performed from a distance and in real time. No sample preparation or pre-treatment is required. Detection of the isotopes of hydrogen, boron, carbon, and oxygen are discussed to illustrate the technique.

  17. Laser Ablation Molecular Isotopic Spectrometry

    Science.gov (United States)

    Russo, Richard E.; Bol'shakov, Alexander A.; Mao, Xianglei; McKay, Christopher P.; Perry, Dale L.; Sorkhabi, Osman

    2011-02-01

    A new method of performing optical isotopic analysis of condensed samples in ambient air and at ambient pressure has been developed: Laser Ablation Molecular Isotopic Spectrometry (LAMIS). The technique uses radiative transitions from molecular species either directly vaporized from a sample or formed by associative mechanisms of atoms or ions in a laser ablation plume. This method is an advanced modification of a known atomic emission technique called laser-induced breakdown spectroscopy (LIBS). The new method — LAMIS — can determine not only chemical composition but also isotopic ratios of elements in the sample. Isotopic measurements are enabled by significantly larger isotopic shifts found in molecular spectra relative to atomic spectra. Analysis can be performed from a distance and in real time. No sample preparation or pre-treatment is required. Detection of the isotopes of hydrogen, boron, carbon, and oxygen are discussed to illustrate the technique.

  18. First fossil evidence of Connaraceae R. Br. from Indian Cenozoic and its phytogeographical significance

    Indian Academy of Sciences (India)

    Mahasin Ali Khan; Subir Bera

    2016-07-01

    Fossil leaflet impression described here as a new species Rourea miocaudata sp. nov., showing close resemblance with the modern leaflets of Rourea caudata Planch. (Connaraceae R. Br.), has been recorded from the lower part of the Siwalik sediments (Dafla Formation, middle–upper Miocene) exposed at the road-cutting section of Pinjoli area in West Kameng district, Arunachal Pradesh. The importantmorphological characters of the fossil are its narrow elliptic leaflet, cuneate base, long caudate apex, entire margin, eucamptodromous to brochidodromous secondary veins, presence of intersecondary veins, percurrent and reticulate tertiary veins and orthogonally reticulate quaternary veins. This is the first authentic record of the occurrence of leaflet comparable to R. caudata of Connaraceae from the Cenozoic sediments of India and abroad. At present R. caudata does not grow in India and is restricted only in southeast Asia especially in China and Myanmar. This taxon probably migrated to these southeast Asian regions after lower Siwalik sedimentation (middle–upper Miocene) due to climatic change causedby post-Miocene orogenic movement of the Himalaya. The recovery of this species and other earlierdescribed evergreen taxa from the same formation, suggests the existence of a tropical, warm and humid climatic conditions during the depositional period.

  19. First fossil evidence of Connaraceae R. Br. from Indian Cenozoic and its phytogeographical significance

    Science.gov (United States)

    Khan, Mahasin Ali; Bera, Subir

    2016-07-01

    Fossil leaflet impression described here as a new species Rourea miocaudata sp. nov., showing close resemblance with the modern leaflets of Rourea caudata Planch. (Connaraceae R. Br.), has been recorded from the lower part of the Siwalik sediments (Dafla Formation, middle-upper Miocene) exposed at the road-cutting section of Pinjoli area in West Kameng district, Arunachal Pradesh. The important morphological characters of the fossil are its narrow elliptic leaflet, cuneate base, long caudate apex, entire margin, eucamptodromous to brochidodromous secondary veins, presence of intersecondary veins, percurrent and reticulate tertiary veins and orthogonally reticulate quaternary veins. This is the first authentic record of the occurrence of leaflet comparable to R. caudata of Connaraceae from the Cenozoic sediments of India and abroad. At present R. caudata does not grow in India and is restricted only in southeast Asia especially in China and Myanmar. This taxon probably migrated to these southeast Asian regions after lower Siwalik sedimentation (middle-upper Miocene) due to climatic change caused by post-Miocene orogenic movement of the Himalaya. The recovery of this species and other earlier-described evergreen taxa from the same formation, suggests the existence of a tropical, warm and humid climatic conditions during the depositional period.

  20. Structural and electronic properties of silicene on MgX2 (X = Cl, Br, and I)

    KAUST Repository

    Zhu, Jiajie

    2014-07-23

    Silicene is a monolayer of Si atoms in a two-dimensional honeycomb lattice, being expected to be compatible with current Si-based nanoelectronics. The behavior of silicene is strongly influenced by the substrate. In this context, its structural and electronic properties on MgX2 (X = Cl, Br, and I) have been investigated using first-principles calculations. Different locations of the Si atoms are found to be energetically degenerate because of the weak van der Waals interaction with the substrates. The Si buckling height is below 0.55 Å, which is close to the value of free-standing silicene (0.49 Å). Importantly, the Dirac cone of silicene is well preserved on MgX2 (located slightly above the Fermi level), and the band gaps induced by the substrate are less than 0.1 eV. Application of an external electric field and stacking can be used to increase the band gap. © 2014 American Chemical Society.

  1. Chemical and isotopic constrains on the origin of brine and saline groundwater in Hetao plain, Inner Mongolia.

    Science.gov (United States)

    Liu, Jun; Chen, Zongyu; Wang, Lijuan; Zhang, Yilong; Li, Zhenghong; Xu, Jiaming; Peng, Yurong

    2016-08-01

    The origin and evolution of brine and saline groundwater have always been a challenged work for geochemists and hydrogeologists. Chemical and isotopic data of brine and saline waters were used to trace the sources of salinity and therefore to understand the transport mechanisms of groundwater in Xishanzui, Inner Mongolia. Both Cl/Br (molar) versus Na/Br (molar) and Cl (meq/L) versus Na (meq/L) indicated that salinity was from halite dissolution or at least a significant impact by halite dissolution. The logarithmic plot of the concentration trends of Cl (mg/L) versus Br (mg/L) for the evaporation of seawater and the Qinghai Salt Lake showed that the terrestrial halite dissolution was the dominated contribution for the salinity of this brine. The stable isotope ratios of hydrogen and oxygen suggested that the origin of brine was from paleorecharge water which experienced mixing of modern water in shallow aquifer. δ(37)Cl values ranged from -0.02 to 3.43 ‰ (SMOC), and reflecting mixing of different sources. The Cl isotopic compositions suggest that the dissolution of halite by paleometeoric water had a great contribution to the salinity of brine, and the contributions of the residual seawater and the dissolution of halite by the Yellow River water could be excluded. PMID:27080408

  2. PSP Program close out documentation

    Energy Technology Data Exchange (ETDEWEB)

    Andringa, K.; Hootman, H.E.; Ferrara, A.S.; Smith, P.K.; Congdon, J.W.; Randolph, H.W.; Young, R.H.; Driggers, F.E.; Topp, S.V.

    1985-12-31

    In December 1982 DOE-SR directed SRL to study the feasibility and impact of a program to lower the U-236 content of the Highly Enriched Uranium (HEU) stockpile used as fuel for the SRP reactors. In response to this request SRL assessed four technologies, Atomic Vapor Laser Isotope Separation (AVLIS), Molecular Laser Isotope Separation (MLIS), Gas Centrifuge, and the Plasma Separation Process (PSP) for this purpose with the assistance of the Engineering Department. In April 1983 cost/benefit analyses for these processes, high spot cost estimates for production facilities, and process uncertainties were submitted to DOE-SR with a recommendation to proceed with the conceptual design and supporting development programs for a facility based on the use of the PSP process. The current program status for the PSP development program at SRL and the design and documentation of a production facility at SRP, referred to as the Fuel Improvement Demonstration Facility (FIDF), is described in this report.

  3. Studies on closed-cycle processes for hydrogen production, 2

    International Nuclear Information System (INIS)

    Studies on the closed-cycle processes for hydrogen production by nuclear energy are reported, which have been carried out in the F.Y. 1975 and 1976. Reactions of FeX2 with CO2 were studied. The highest CO concentrations observed experimentally in the CO2 stream were 2% by FeCl2, 6% by FeBr2 and 22% by FeI2. Salt additions to iron halides did not increase significantly the CO concentration. By x-ray diffractometry, Fe3O4 was the only iron oxide from the high temperature reaction. Halogenation of Fe3O4 was studied in aqueous or gaseous phase with X2 and HX (X=Cl, Br, I). O2 was formed only by the reaction of Cl2. Employment in the hydrogen production processes of CO shift reaction was discussed. CO2 admixed with C3H8 was irradiated. The following products were identified and their yields measured; CO, H2O, (CH3)2, i-PrOH, H2, CH4, C2H6, C4H10, C5H12 and C6H14. Efficiencies of the conversion of the absorbed radiation energy to potential energies of the products were calculated to be 1.5% for γ-rays and 2.0% for fission fragments. (auth.)

  4. Isotopes as natural tracers in the water cycle: examples from the Carpathian Basin

    International Nuclear Information System (INIS)

    Environmental isotopes are the best tracers in the water cycle. These isotopes can be grouped by different point of views, e.g. 1) stable or radioactive; 2) incorporated in the water molecule or not incorporated in the water molecule. Those incorporated in the water molecule gives information about the water itself, while the others give information about the solutes or physical conditions during the infiltration of water. The stable environmental isotopes: 1 H, 2 H (D), 3 He, 4 He, 6 Li, 7 Li, 10 B, 11 B, 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 20 Ne, 22 Ne, 32 S, 34 S, 35 Cl, 37 Cl, 79 Br, 81 Br, 86 Sr, 87 Sr. The radioactive environmental isotopes: 3 H (T), 14 C, 37 Cl, 39 Ar, 85 Kr, 129 I, 222 Rn, 226 Ra, 230 Th, 234 U, 238 U. Among the above isotopes the most commonly used are T, 2 H/1 H, 18 O/16 O, 13 C/12 C, 14 C. The stable isotope composition (δD, δ18 O) of precipitation depends on the distance from the seas, altitude, latitude and the mean temperature of surface air. As a result of the relation between the temperature and the stable isotope composition of precipitation, deeper groundwater resources infiltrated during the Ice Age in the Carpathian Basin possess an isotopic composition definitely different from those infiltrated during the Holocene (latest 10 000 years). Regarding the oxygen isotope composition: the δ18 O value of the Ice Age water is between -11 0/00 and -14 0/00 vs. VSMOW, while that of the Holocene water is between -9 0/00 and -9.7 0/00. This phenomenon allows us to trace the flow of water under the surface, to determine the origin of water and to identify mixing processes. Usual problem is the over-exploitation of groundwater, when the amount of extracted (exploited) water is higher than what the aquifer can provide, and, as a result, the potentially or actually polluted near surface water flows down to the aquifer and mixes with the deep water. In the Carpathian Basin, in many cases, this deep groundwater was infiltrated in the

  5. Seasonal variability of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in a temperate lake system

    Science.gov (United States)

    Loomis, Shannon E.; Russell, James M.; Heureux, Ana M.; D'Andrea, William J.; Sinninghe Damsté, Jaap S.

    2014-11-01

    Quantitative climate reconstructions are crucial for understanding the magnitude of and mechanisms behind natural and anthropogenic climate change, yet there are few proxies that can reliably reconstruct terrestrial temperature. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that are increasingly used to reconstruct paleotemperature from lake sediments, but despite their potential, we have a poor understanding of (1) autochthonous vs. allochthonous sources of brGDGTs in lakes and (2) the seasonality of and environmental controls on brGDGT production within lakes. To investigate these factors, we examined water column suspended particulate matter (SPM) and settling particles from a sediment trap collected on a biweekly to monthly basis over a period of three years at Lower King Pond, a small kettle lake in northern Vermont, USA. We also compared the concentration and fractional abundances of brGDGTs in SPM and settling particles with those of catchment soils, river sediments, and lake surface sediments to constrain the relative importance of brGDGTs derived from the landscape versus brGDGTs produced within the lake itself. We find significant differences in concentrations and fractional abundances of brGDGTs between soil and river sediment samples from the catchment and lake sediments, indicating a mostly autochthonous source for lacustrine brGDGTs. BrGDGT concentrations, fluxes, and fractional abundances in SPM vary over the annual cycle, indicating that brGDGTs are produced throughout the year and respond to changes within the water column. The total annual flux of brGDGTs settling through the water column is comparable to the brGDGT accumulation rates in surface sediments, indicating that in this lake brGDGTs are mostly produced within the water column, not in the sediment itself. While brGDGTs are produced in all seasons within the water column, the flux to the sediments is highest during periods of spring and fall

  6. Isotope thermometery in nuclear multifragmentation

    OpenAIRE

    Agrawal, B. K.; Samaddar, S. K.; Sil, Tapas; J. N.

    1998-01-01

    A systematic study of the effect of fragment$-$fragment interaction, quantum statistics, $\\gamma$-feeding and collective flow is made in the extraction of the nuclear temperature from the double ratio of the isotopic yields in the statistical model of one-step (Prompt) multifragmentation. Temperature is also extracted from the isotope yield ratios generated in the sequential binary-decay model. Comparison of the thermodynamic temperature with the extracted temperatures for different isotope r...

  7. Iodine isotopes in radiation hygiene

    International Nuclear Information System (INIS)

    Radioactive iodine isotopes belong among the factors of anthropogenic contamination of the biosphere. A radiation hygiene survey is presented of literary data and the author's own results of studies of the metabolism and biological effect of radioactive isotopes of iodine. The risk of their intake by the human organism is evaluated. Particular attention is paid to 132-135I and 129I. Data on the biological danger of these isotopes are scarce in the literature. (author)

  8. Systematic hardness measurements on CsClBr(1–x) and NH4ClBr(1–x) mixed crystals

    Indian Academy of Sciences (India)

    K G Subhadra; E Balaiah; D B Sirdeshmukh

    2002-02-01

    Vickers hardness measurements have been made on polycrystalline blanks of CsClBr(1–x) and single crystals of NH4ClBr(1–x). The composition dependence of hardness is highly nonlinear in both systems and follows an empirical model that includes a lattice contribution and a disorder contribution. The Gilman–Chin parameter (/44) has been calculated and its significance discussed.

  9. Localization of fluctuation measurement by wave scattering close to a cut off layer

    International Nuclear Information System (INIS)

    In tokamaks several fluctuation diagnostics are based on the scattering of an electromagnetic wave close to a cut off layer. For example measurement of density fluctuations (n) by reflectometry and magnetic fluctuations (B) by cross polarization scattering. For such a configuration the eikonal approximation does not remain valid to describe the pump wave although it is valid to describe n(r) and B(r). In this paper we shall consider a linear density profile. An unidimensional exact analysis has been performed. Spatial and spectral localization of scattering process close to the cut off layer is investigated and a modified Bragg rule is derived. (author) 6 refs., 2 figs

  10. MRI of closed spinal dysraphisms

    Energy Technology Data Exchange (ETDEWEB)

    Badve, Chaitra A.; Khanna, Paritosh C.; Phillips, Grace S.; Thapa, Mahesh M.; Ishak, Gisele E. [Seattle Children' s Hospital and University of Washington Medical Center, Department of Radiology, Seattle, WA (United States)

    2011-10-15

    We present a pictorial review of MRI features of various closed spinal dysraphisms based on previously described clinicoradiological classification of spinal dysraphisms proposed. The defining imaging features of each dysraphism type are highlighted and a diagnostic algorithm for closed spinal dysraphisms is suggested. (orig.)

  11. Postdivorce Father-Adolescent Closeness

    Science.gov (United States)

    Scott, Mindy E.; Booth, Alan; King, Valarie; Johnson, David R.

    2007-01-01

    Research indicates that closeness of the father-child bond following parental divorce is associated with better outcomes for children and adolescents. Unlike other investigations, this study takes a long-term developmental approach to understanding stability and change in postdivorce father-adolescent relationship closeness. Drawing on Add Health…

  12. Metal Stable Isotopes in Paleoceanography

    Science.gov (United States)

    Anbar, Ariel D.; Rouxel, Olivier

    2007-05-01

    Considered esoteric only a few years ago, research into the stable isotope geochemistry of transition metals is moving into the geoscience mainstream. Although initial attention focused on the potential use of some of these nontraditional isotope systems as biosignatures, they are now emerging as powerful paleoceanographic proxies. In particular, the Fe and Mo isotope systems are providing information about changes in oxygenation and metal cycling in ancient oceans. Zn, Cu, Tl, and a number of other metals and metalloids also show promise. Here we review the basis of stable isotope fractionation as it applies to these elements, analytical considerations, and the current status and future prospects of this rapidly developing research area.

  13. Synthesis and structure of [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 . 3H2O

    International Nuclear Information System (INIS)

    The complex [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 . 3H2O is synthesized by the reaction of K2OsBr6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) A, b = 14.052(3) A, c = 16.994(3) A, space group Cmcm, and Z = 4. The [OsBr6]2- anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483-2.490 A. The α,α'-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 A, respectively. The H2O molecules, Br-ions, and NH2 groups of the cation are linked by hydrogen bonds.

  14. SCK-CEN increases production of medical isotopes by half

    International Nuclear Information System (INIS)

    It is impossible to imagine the medical world today without radioisotopes, and due to rapid technological progress in nuclear medicine their use is still on the rise. An important role of research reactors is the production of molybdenum-99. Around the world this is done primarily by five nuclear research reactors, one of which is the BR2 reactor of SCK-CEN. As a result of checks and maintenance work on three other reactors, for a few years there has been a serious crisis in the availability of this medical isotope. In order to guarantee the worldwide supply of radioisotopes, SCK-CEN expanded its production of molybdenum-99 by 50 percent in 2010.

  15. Advanced isotope separation

    International Nuclear Information System (INIS)

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  16. Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC.

    Science.gov (United States)

    Li, Xiaorong; Zhang, Shaofeng; Bai, Jinjuan; He, Yuke

    2016-03-01

    Several oilseed and vegetable crops of Brassica are biennials that require a prolonged winter cold for flowering, a process called vernalization. FLOWERING LOCUS C (FLC) is a central repressor of flowering. Here, we report that the overexpression of natural antisense transcripts (NATs) of Brassica rapa FLC (BrFLC) greatly shortens plant growth cycles. In rapid-, medium- and slow-cycling crop types, there are four copies of the BrFLC genes, which show extensive variation in sequences and expression levels. In Bre, a biennial crop type that requires vernalization, five NATs derived from the BrFLC2 locus are rapidly induced under cold conditions, while all four BrFLC genes are gradually down-regulated. The transgenic Bre lines overexpressing a long NAT of BrFLC2 do not require vernalization, resulting in a gradient of shortened growth cycles. Among them, a subset of lines both flower and set seeds as early as Yellow sarson, an annual crop type in which all four BrFLC genes have non-sense mutations and are nonfunctional in flowering repression. Our results demonstrate that the growth cycles of biennial crops of Brassica can be altered by changing the expression levels of BrFLC2 NATs. Thus, BrFLC2 NATs and their transgenic lines are useful for the genetic manipulation of crop growth cycles. PMID:26250982

  17. Measurement and simulation of proton induced activation of LaBr3 : Ce

    NARCIS (Netherlands)

    Buis, E. J.; Beijers, H.; Brandenburg, S.; Bos, A. J. J.; Dathy, C.; Dorenbos, P.; Drozdowski, W.; Kraft, S.; Maddox, E.; Ostendorf, R. W.; Owens, A.; Quarati, F.

    2007-01-01

    To assess the suitability of LaBr3:Ce scintillators for space mission applications, proton induced activation of LaBr3 has been investigated. The crystals were irradiated using proton beams at several different energies to mimic the spectrum of a solar flare. We have measured the activation both int

  18. Insects, isotopes and radiation

    International Nuclear Information System (INIS)

    The sterile insect technique (SIT), which uses radiation to sexually sterilize insects and prevent reproduction, is particularly effective in eradicating harmful insects. The Joint Division of the IAEA/FAO has been involved in the use of isotopes and radiation in insect control since 1964. Efforts by the IAEA and FAO to transfer the SIT technology to developing countries are continuing by providing valuable research and development support for field projects. The cooperative SIT project against the tse tse fly was very successful in eradicating this harmful pest from the north-central Nigeria. A similar SIT project is actually underway to eradicate the Mediteranean fruit fly in Mexico

  19. Cold regions isotope applications

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids

  20. Tank waste isotope contributions

    International Nuclear Information System (INIS)

    This document presents the results of a calculation to determine the relative contribution of selected isotopes to the inhalation and ingestion doses for a postulated release of Hanford tank waste. The fraction of the dose due to 90Sr, 90Y, 137Cs and the alpha emitters for single shell solids and liquids, double shell solids and liquids, aging waste solids and liquids and all solids and liquids. An effective dose conversion factor was also calculated for the alpha emitters for each composite of the tank waste