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Sample records for hot muonic hydrogen

  1. Muon transfer from hot muonic hydrogen atoms to neon

    International Nuclear Information System (INIS)

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

    1992-01-01

    A negative muon beam has been directed on adjacent solid layers of hydrogen and neon. Three targets differing by their deuterium concentration were investigated. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. The time structure of the muonic neon X-rays follows the exponential law with a disappearance rate corresponding to the one of μ -p atoms in each target. The rates λ ppμ and λ pd can be extracted

  2. Detection of hot muonic hydrogen atoms emitted in vacuum using x-rays

    International Nuclear Information System (INIS)

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

    1992-01-01

    Negative muons are stopped in solid layers of hydrogen and neon. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. It was found that the time structure of the muonic neon X-rays follows the exponential law where the rate is the same as the disappearance rate of μ - p atoms. The ppμ-formation rate and the muon transfer rate to deuterium are deduced

  3. Time of flight spectroscopy with muonic hydrogen

    International Nuclear Information System (INIS)

    Marshall, G.M.; Bailey, J.M.; Beer, G.A.

    1993-01-01

    Time of flight techniques coupled with muonic deuterium and tritium atoms in vacuum can be used to measure parameters important in the understanding of muon catalyzed fusion interactions. Muonic deuterium atomic beams with energy of order 1 eV have been produced via transfer and emission from solid hydrogen containing small deuterium concentrations. Measurements of energy loss in pure deuterium are presented which test calculations of σ μd+D . Muonic tritium beams should be produced in a similar way, with an energy distribution which overlaps the predicted muonic molecular (dμt) formation resonances. The existence of resonances is crucial for high cycling rates in muon catalyzed fusion, but direct experimental verification of strengths and energies is not yet possible by other means. Results of simulations demonstrate how the resonance structure might be confirmed

  4. Muonium/muonic hydrogen formation in atomic hydrogen

    Indian Academy of Sciences (India)

    The muonium/muonic hydrogen atom formation in ± –H collisions is investigated, using a two-state approximation in a time dependent formalism. It is found that muonium cross-section results are similar to the cross-section results obtained for positronium formation in + –H collision. Muonic hydrogen atom formation ...

  5. Hot muonic deuterium and tritium from cold targets

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  6. Hyperfine splitting in ordinary and muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Tomalak, Oleksandr [Johannes Gutenberg Universitaet, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

    2018-01-15

    We provide an accurate evaluation of the two-photon exchange correction to the hyperfine splitting of S energy levels in muonic hydrogen exploiting the corresponding measurements in electronic hydrogen. The proton structure uncertainty in the calculation of α{sup 5} contribution is sizably reduced. (orig.)

  7. Cascade Processes in Muonic Hydrogen Atoms

    International Nuclear Information System (INIS)

    Faifman, M. P.; Men'Shikov, L. I.

    2001-01-01

    The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

  8. Theory of Lamb Shift in Muonic Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Karshenboim, Savely G., E-mail: savely.karshenboim@mpq.mpg.de [Max-Planck-Institut für Quantenoptik, Garching 85748, Germany and Pulkovo Observatory, St. Petersburg 196140 (Russian Federation); Korzinin, Evgeny Yu.; Shelyuto, Valery A. [D. I. Mendeleev Institute for Metrology, St. Petersburg 190005 (Russian Federation); Ivanov, Vladimir G. [Pulkovo Observatory, St. Petersburg 196140 (Russian Federation)

    2015-09-15

    There has been for a while a large discrepancy between the values of the proton charge radius measured by the Lamb shift in muonic hydrogen and by other methods. It has already been clear that theory of muonic hydrogen is reliable at the level of this discrepancy and an error there cannot be a reason for the contradiction. Still the status of theory at the level of the uncertainty of the muonic-hydrogen experiment (which is two orders of magnitude below the discrepancy level) requires an additional clarification. Here, we revisit theory of the 2p − 2s Lamb shift in muonic hydrogen. We summarize all the theoretical contributions in order α{sup 5}m, including pure quantum electrodynamics (QED) ones as well as those which involve the proton-structure effects. Certain enhanced higher-order effects are also discussed. We basically confirm former QED calculations of other authors, present a review of recent calculations of the proton-structure effects, and treat self-consistently higher-order proton-finite-size corrections. We also overview theory of the 2p states. Eventually, we derive a value of the root-mean-square proton charge radius. It is found to be 0.840 29(55) fm, which is slightly different from that previously published in the literature (0.840 87(39) fm [Antognini et al., Science 339, 417 (2013)])

  9. Kinetics of the excited muonic hydrogen in the mixtures of hydrogen isotopes in helium

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Kravtsov, A.V.; Popov, N.P.

    1989-01-01

    De-excitation of the excited muonic hydrogen in the mixture of hydrogen isotopes and helium is considered. The method is proposed which allows one to determine the rates of the muon transfer from the excited muonic hydrogen to helium nuclei, as well as the probability of the direct muon atomic capture by nuclei of hydrogen isotopes. 20 refs.; 4 figs

  10. The Lamb shift in muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Nebel, Tobias

    2010-06-25

    The subject of this thesis is the first measurement of the 2S-2P Lamb shift in muonic hydrogen ({mu}p). In this project, which has been performed at the proton-accelerator facility of the Paul-Scherrer-Institute in Switzerland, the exotic analogon to the classical Lamb shift in hydrogen has been examined by laser spectroscopy. Negative muons are produced at a specially developed low-energy muon beam at a rate of 330 s{sup -1} and are stopped in 1 hPa of H{sub 2} gas. In the gas, highly excited {mu}p atoms are formed, most of which promptly cascade to the ground state within {proportional_to}100 ns. Only a fraction of 1.1% forms {mu}p atoms in the long-lived 2S state with a lifetime of 1.0 {mu}s. An elaborate laser system triggered on every incoming muon delivers 0.2 mJ laser pulses at {lambda}{approx_equal}6 {mu}m with 500 s{sup -1} repetition rate. The laser illuminates the {mu}p atoms 900 ns after the prompt muon cascade inducing the 2S-2P transition when on resonance. A 1.9 keV K{sub {alpha}} X-ray is emitted in the subsequent deexcitation to the 1S ground state and is recorded by large area avalanche photodiodes. The laser induced K{sub {alpha}} events are clearly distinguishable from the exponential background. For the 2S{sub 1/2}{sup F=1} - 2P{sub 3/2}{sup F=2} transition in {mu}p, it is given by {nu}{sub 2S-2P}=49 881 695 (711)MHz with a relative accuracy of 1.4 x 10{sup -5}. Assuming the correctness of the bound-state QED calculations of the Lamb shift in {mu}p, a new value for the rms proton charge radius r{sub p} can be derived: r{sub p}=0:84192(65) fm. Using the precisely measured 1S-2S transition frequency in hydrogen (relative accuracy of 1.4 parts in 10{sup 14}) and combining it with our new value of r{sub p}, a new value for the Rydberg constant R{sub {infinity}} can be derived with a relative accuracy of 1.5 parts in 10{sup 12}: R{sub {infinity}}=10 973 731.568 161(16)m{sup -1}. Beside the 2S{sub 1/2}{sup F=1}-2P{sub 3/2}{sup F=2} transition in {mu

  11. Laser spectroscopy of muonic hydrogen and the puzzling proton

    International Nuclear Information System (INIS)

    Pohl, Randolf

    2016-01-01

    Laser spectroscopy of muonic hydrogen atoms, μp, has revealed a proton root-mean-square (rms) charge radius r_E that is an order of magnitude more accurate than the CODATA world average from elastic electron–proton scattering and precision spectroscopy of regular (electronic) hydrogen. Interestingly, though, the value of r_E from μp is 4%, or 7 combined standard deviations smaller than the CODATA value of r_E. This discrepancy has been coined “proton radius puzzle”. We summarize the experiment and give a brief overview of the theory in muonic hydrogen. Finally we discuss some possible scenarios for the resolution of the “proton radius puzzle”. (author)

  12. Emission of muonic hydrogen isotopes from solid hydrogen layers into vacuum

    International Nuclear Information System (INIS)

    Marshall, G.M.; Bailey, J.M.; Beer, G.A.

    1989-10-01

    An attempt was made to create in vacuum free muonic hydrogen atoms, muonic protium and muonic deuterium. The method was based on slowing a beam of μ - in a layer of solid hydrogen in vacuum frozen to a cold gold foil substrate. Muonic hydrogen formed near the surface is emitted from it into the vacuum with an energy spectrum determined by the formation and subsequent scattering processes. For a typical total cross section of 10 -19 cm 2 the interaction probability is 0.43 μm -1 . For emission at an energy of order 1 eV, the muonic atom travels about 10 mm in vacuum prior to decay. No corresponding signal was observed with a deuterium layer of 6 mg/cm 2 . The natural abundance of deuterons in hydrogen leads to transfer of the muon in a mean time of about 500 ns, and because of the reduced mass difference, the m u - d obtains a kinetic energy of 45 eV, from which the atom will scatter and slow until the energy of the Ramsauer-Townsend minimum is reached and the hydrogen film becomes nearly transparent to μ - d. The Ramsauer-Townsend effect is also expected to show up for tritium in protium, which means a source of μ - t in vacuum should be possible

  13. Atlas cross section for scattering of muonic hydrogen atoms on hydrogen isotope molecules

    International Nuclear Information System (INIS)

    Adamczak, A.; Faifman, M.P.; Ponomarev, L.I.

    1996-01-01

    The total cross sections of the elastic, spin-flip, and charge-exchange processes for the scattering of muonic hydrogen isotope atoms (pμ, dμ, tμ) in the ground state on the hydrogen isotope molecules (H 2 , D 2 , T 2 , HD, HT, DT) are calculated. The scattering cross sections of muonic hydrogen isotope atoms on hydrogen isotope nuclei obtained earlier in the multichannel adiabatic approach are used in the calculations. Molecular effects (electron screening, rotational and vibrational excitations of target molecules, etc.) are taken into account. The spin effects of the target molecules and of the incident muonic atoms are included. the cross sections are averaged over the Boltzmann distribution of the molecule rotational states and the Maxwellian distribution of the target molecule kinetic energies for temperatures 30, 100, 300, and 1000 K. The cross sections are given for kinetic energies of the incident muonic atoms ranging from 0.001 to 100 eV in the laboratory frame. 45 refs., 6 tabs

  14. Two-photon exchange correction to the hyperfine splitting in muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Tomalak, Oleksandr [Johannes Gutenberg Universitaet, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

    2017-12-15

    We reevaluate the Zemach, recoil and polarizability corrections to the hyperfine splitting in muonic hydrogen expressing them through the low-energy proton structure constants and obtain the precise values of the Zemach radius and two-photon exchange (TPE) contribution. The uncertainty of TPE correction to S energy levels in muonic hydrogen of 105 ppm exceeds the ppm accuracy level of the forthcoming 1S hyperfine splitting measurements at PSI, J-PARC and RIKEN-RAL. (orig.)

  15. The contribution of axial-vector mesons to hyperfine structure of muonic hydrogen

    OpenAIRE

    Dorokhov, A. E.; Kochelev, N. I.; Martynenko, A. P.; Martynenko, F. A.; Radzhabov, A. E.

    2017-01-01

    The contribution from the axial-vector meson exchange to the potential of the muon–proton interaction in muonic hydrogen induced by anomalous axial-vector meson coupling to two photon state is calculated. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is large and important for a comparison with precise experimental data. In the light of our result, the proton radius “puzzle” is discussed.

  16. Time evolution of cascade processes of muonic atoms in hydrogen-helium mixtures

    International Nuclear Information System (INIS)

    Bystritskij, V.; Czaplinski, W.; Filipowicz, M.; Gula, E.; Popov, N.

    1999-01-01

    Time dependence of population of muonic hydrogen states in hydrogen-helium mixtures is calculated for principal quantum number n. Number of muons transferred to helium nuclei is also determined. Dependence of population of the ground state of muonic hydrogen q ls He on time and target density and helium concentration is also considered. The results are in agreement with recent experimental data. The comparison of the calculated yield of K lines of x-ray in pure hydrogen and deuterium with experimental data indicates on essential role of Coulomb de-excitation process. Possible Stark mixing is also analyzed

  17. Muon transfer from muonic hydrogen to heavier atoms; Transfert de charge muonique

    Energy Technology Data Exchange (ETDEWEB)

    Dupays, A

    2004-06-01

    This work concerns muon transfer from muonic hydrogen to heavier atoms. Recently, a method of measurement of the hyperfine structure of ground-state muonic hydrogen based on the collision energy dependence of the muon transfer rate to oxygen has been proposed. This proposal is based on measurements which where performed at the Paul Scherrer Institute in the early nineties which indicate that the muon transfer from muonic hydrogen to oxygen increases by a factor of 4 going from thermal to 0.12 eV energies. The motivation of our calculations was to confirm this behaviour. To study the collision energy dependence of the muon transfer rate, we have used a time-independent close-coupling method. We have set up an hyperspherical elliptic formalism valid for nonzero total angular momentum which allows accurate computations of state-to-state reactive and charge exchange processes. We have applied this formalism to muon-transfer process to oxygen and neon. The comparison with experimental results is in both cases excellent. Finally, the neon transfer rate dependence with energy suggests to use neon instead of oxygen to perform a measurement of the hyperfine structure of muonic hydrogen. The results of accurate calculations of the muon transfer rates from muonic protium and deuterium atoms to nitrogen, oxygen and neon are also reported. Very good agreement with measured rates is obtained and for the three systems, the isotopic effect is perfectly reproduced. (author)

  18. The hadronic corrections to muonic hydrogen Lamb shift from ChPT and the proton radius

    Energy Technology Data Exchange (ETDEWEB)

    Peset, Clara [Grup de Física Teòrica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2016-01-22

    We obtain a model independent expression for the muonic hydrogen Lamb shift. The leading hadronic effects are controlled by the chiral theory, which allows for their model independent determination. We give their complete expression including the pion and Delta particles. Out of this analysis and the experimental measurement of the muonic hydrogen Lamb shift we determine the electromagnetic proton radius: r{sub p} = 0.8412(15) fm. This number is at 6.8σ variance with respect to the CODATA value. The parametric control of the uncertainties allows us to obtain a model independent determination of the error, which is dominated by hadronic effects.

  19. Lamb shift in muonic hydrogen-II. Analysis of the discrepancy of theory and experiment

    International Nuclear Information System (INIS)

    Jentschura, U.D.

    2011-01-01

    Research highlights: → Various theoretical explanation for the recently observed experimental-theoretical discrepancy in the muonic hydrogen Lamb shift are explored. → These include a dip in the proton form factor slope, nonperturbative vacuum polarization and millicharged virtual particles, as well as process-dependent screening corrections. → Screening corrections may need to be explored further. → The need for an alternative determination of the Rydberg constant is highlighted. - Abstract: Currently, both the g factor measurement of the muon as well as the Lamb shift 2S-2P measurement in muonic hydrogen are in disagreement with theory. Here, we investigate possible theoretical explanations, including proton structure effects and small modifications of the vacuum polarization potential. In particular, we investigate a conceivable small modification of the spectral function of vacuum polarization in between the electron and muon energy scales due to a virtual millicharged particle and due to an unstable vector boson originating from a hidden sector of an extended standard model. We find that a virtual millicharged particle which could explain the muonic Lamb shift discrepancy alters theoretical predictions for the muon anomalous magnetic moment by many standard deviations and therefore is in conflict with experiment. Also, we find no parameterizations of an unstable virtual vector boson which could simultaneously explain both 'muonic' discrepancies without significantly altering theoretical predictions for electronic hydrogen, where theory and experiment currently are in excellent agreement. A process-dependent correction involving electron screening is evaluated to have the right sign and order-of-magnitude to explain the observed effect in muonic hydrogen. Additional experimental evidence from light muonic atoms and ions is needed in order to reach further clarification.

  20. The contribution of pseudoscalar mesons to hyperfine structure of muonic hydrogen

    International Nuclear Information System (INIS)

    Dorokhov, A.E.; Kochelev, N.I.; Martynenko, A.P.; Martynenko, F.A.; Faustov, R.N.

    2017-01-01

    In the framework of the quasipotential method in quantum electrodynamics we calculate the contribution of pseudoscalar mesons to the interaction operator of a muon and a proton in muonic hydrogen atom. The parametrization of the transition form factor of two photons into π, η mesons, based on the experimental data on the transition form factors and QCD asymptotics is used. Numerical estimates of the contributions to the hyperfine structure of the spectrum of the S and P levels are presented.

  1. The contribution of pseudoscalar and axial-vector mesons to hyperfine structure of muonic hydrogen

    OpenAIRE

    Dorokhov, A. E.; Kochelev, N. I.; Martynenko, A. P.; Martynenko, F. A.; Radzhabov, A. E.; Faustov, R. N.

    2017-01-01

    In the framework of the quasipotential method in quantum electrodynamics we calculate the contribution of light pseudoscalar (PS) and axial-vector (AV) mesons to the interaction operator of a muon and a proton in muonic hydrogen atom. The coupling of mesons with the muon is via two-photon intermediate state. The parametrization of the transition form factor of two photons into PS and AV mesons, based on the experimental data on the transition form factors and QCD asymptotics, is used. Numeric...

  2. The contribution of pseudoscalar mesons to hyperfine structure of muonic hydrogen

    OpenAIRE

    Dorokhov, A. E.; Kochelev, N. I.; Martynenko, A. P.; Martynenko, F. A.; Faustov, R. N.

    2017-01-01

    In the framework of the quasipotential method in quantum electrodynamics we calculate the contribution of pseudoscalar mesons to the interaction operator of a muon and a proton in muonic hydrogen atom. The parametrization of the transition form factor of two photons into $\\pi$, $\\eta$ mesons, based on the experimental data on the transition form factors and QCD asymptotics is used. Numerical estimates of the contributions to the hyperfine structure of the spectrum of the S and P levels are pr...

  3. Geneva University - Measurement of the Lamb shift in muonic hydrogen: the proton radius puzzle

    CERN Multimedia

    2010-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 12 May 2010 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium Measurement of the Lamb shift in muonic hydrogen: the proton radius puzzle Dr Aldo Antogninia , CREMA Collaboration, Max Planck Institute, Germany At the Paul Scherrer Institut, Switzerland, we have measured several 2S-2P transition frequencies in muonic hydrogen (µp) and deuterium (µd) by means of laser spectroscopy. This results in an order of magnitude improvement on the rms charge radius values of the proton and the deuteron. Additionally the Zemach radii and the deuteron polarizability are also inferred. The new proton radius value is deduced with a relative accuracy of 0.1% but strongly disagrees from CODATA. The origin of this discrepancy is not yet known. It may come from theo...

  4. Lamb shift in muonic hydrogen-I. Verification and update of theoretical predictions

    International Nuclear Information System (INIS)

    Jentschura, U.D.

    2011-01-01

    Research highlights: → The QED theory of muonic hydrogen energy levels is verified and updated. → Previously obtained results of Pachucki and Borie are confirmed. → The influence of the vacuum polarization potential onto the Bethe logarithm is calculated nonperturbatively. → A model-independent estimate of the Zemach moment correction is given. → Parametrically, the observed discrepancy of theory and experiment is shown to be substantial and large. - Abstract: In view of the recently observed discrepancy of theory and experiment for muonic hydrogen [R. Pohl et al., Nature 466 (2010) 213], we reexamine the theory on which the quantum electrodynamic (QED) predictions are based. In particular, we update the theory of the 2P-2S Lamb shift, by calculating the self-energy of the bound muon in the full Coulomb + vacuum polarization (Uehling) potential. We also investigate the relativistic two-body corrections to the vacuum polarization shift, and we analyze the influence of the shape of the nuclear charge distribution on the proton radius determination. The uncertainty associated with the third Zemach moment 3 > 2 in the determination of the proton radius from the measurement is estimated. An updated theoretical prediction for the 2S-2P transition is given.

  5. Toward the measurement of the hyperfine splitting in the ground state of muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Adamczak, Andrzej [Polish Academy of Sciences, Institute of Nuclear Physics (Poland); Stoilov, Mihail [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Vacchi, Andrea [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste (Italy)

    2015-08-15

    The recent Lamb shift experiment at PSI and the controversy about proton size revived the interest in measuring the hyperfine splitting in muonic hydrogen and extracting the proton Zemach radius. The efficiency of the experimental method depends on the energy dependence of the muon transfer rate to higher-Z gases in the near epithermal energy range. As long as the available experimental data only give the average transfer rate in the whole epithermal range, and the detailed theoretical calculations have not yet been verified, an experiment has been started for the measurement of the transfer rate in thermalized gas target at different temperatures and extracting from the data an estimate of the transfer rate for arbitrary energies. We outline the underlying mathematical method and estimate its accuracy.

  6. The Lamb shift in muonic hydrogen and the proton radius from effective field theories

    Energy Technology Data Exchange (ETDEWEB)

    Peset, Clara; Pineda, Antonio [Universitat Autonoma de Barcelona, Grup de Fisica Teorica, Dept. Fisica and IFAE, Bellaterra (Barcelona) (Spain)

    2015-12-15

    We comprehensively analyse the theoretical prediction for the Lamb shift in muonic hydrogen, and the associated determination of the proton radius. We use effective field theories. This allows us to relate the proton radius with well-defined objects in quantum field theory, eliminating unnecessary model dependence. The use of effective field theories also helps us to organize the computation so that we can clearly state the parametric accuracy of the result. In this paper we review all (and check several of) the contributions to the energy shift of order α{sup 5}, as well as those that scale like α{sup 6} x logarithms in the context of non-relativistic effective field theories of QED. (orig.)

  7. Hot Hydrogen Test Facility

    International Nuclear Information System (INIS)

    W. David Swank

    2007-01-01

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISp. This quantity is proportional to the square root of the propellant's absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500 C hydrogen flowing at 1500 liters per minute. The facility is intended to test non-uranium containing materials and therefore is particularly suited for testing potential cladding and coating materials. In this first installment the facility is described. Automated Data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed

  8. Model-independent determination of the two-photon exchange contribution to hyperfine splitting in muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Peset, Clara; Pineda, Antonio [Grup de Física Teòrica, Dept. Física and IFAE-BIST, Universitat Autònoma de Barcelona,E-08193 Bellaterra (Barcelona) (Spain)

    2017-04-11

    We obtain a model-independent prediction for the two-photon exchange contribution to the hyperfine splitting in muonic hydrogen. We use the relation of the Wilson coefficients of the spin-dependent dimension-six four-fermion operator of NRQED applied to the electron-proton and to the muon-proton sectors. Their difference can be reliably computed using chiral perturbation theory, whereas the Wilson coefficient of the electron-proton sector can be determined from the hyperfine splitting in hydrogen. This allows us to give a precise model-independent determination of the Wilson coefficient for the muon-proton sector, and consequently of the two-photon exchange contribution to the hyperfine splitting in muonic hydrogen, which reads δĒ{sub pμ,HF}{sup TPE}(nS)=−(1/(n{sup 3}))1.161(20) meV. Together with the associated QED analysis, we obtain a prediction for the hyperfine splitting in muonic hydrogen that reads E{sub pμ,HF}{sup th}(1S)=182.623(27) meV and E{sub pμ,HF}{sup th}(2S)=22.8123(33) meV. The error is dominated by the two-photon exchange contribution.

  9. Hot Hydrogen Heat Source Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a  hot hydrogen heat source that would produce  a high temperature hydrogen flow which would be comparable to that produced...

  10. Hydrogen isotope effect on muonic x-ray spectra of (CH2)/sub x/ and H2O

    International Nuclear Information System (INIS)

    Mausner, L.F.; Knight, J.D.; Orth, C.J.; Schillaci, M.E.; Naumann, R.A.

    1977-01-01

    We have measured the muonic x-ray intensity patterns of C in (CH 2 )/sub x/ and (CD 2 )/sub x/ and of O in H 2 O and D 2 O. In both cases the relative intensities of the higher Lyman series members are significantly lower in the deuterium compounds, indicating that the initial angular momentum distribution of the muons captured on C and O is weighted to higher l states compared to the normal hydrogen compounds. This isotope effect has not been predicted by any model of negative-meson capture

  11. Radiative nonrecoil nuclear finite size corrections of order α(Zα){sup 5} to the hyperfine splitting of S-states in muonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Faustov, R.N. [Dorodnicyn Computing Centre, Russian Academy of Science, Vavilov Str. 40, 119991 Moscow (Russian Federation); Martynenko, A.P. [Samara State University, Pavlov Str. 1, 443011 Samara (Russian Federation); Samara State Aerospace University named after S.P. Korolyov, Moskovskoye Shosse 34, 443086 Samara (Russian Federation); Martynenko, G.A.; Sorokin, V.V. [Samara State University, Pavlov Str. 1, 443011 Samara (Russian Federation)

    2014-06-02

    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα){sup 5} to the hyperfine structure of S-wave energy levels in muonic hydrogen and muonic deuterium. For the construction of the particle interaction operator we employ the projection operators on the particle bound states with definite spins. The calculation is performed in the infrared safe Fried–Yennie gauge. Modern experimental data on the electromagnetic form factors of the proton and deuteron are used.

  12. Radiative nonrecoil nuclear finite size corrections of order α(Zα)5 to the hyperfine splitting of S-states in muonic hydrogen

    International Nuclear Information System (INIS)

    Faustov, R.N.; Martynenko, A.P.; Martynenko, G.A.; Sorokin, V.V.

    2014-01-01

    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα) 5 to the hyperfine structure of S-wave energy levels in muonic hydrogen and muonic deuterium. For the construction of the particle interaction operator we employ the projection operators on the particle bound states with definite spins. The calculation is performed in the infrared safe Fried–Yennie gauge. Modern experimental data on the electromagnetic form factors of the proton and deuteron are used.

  13. Investigation of the hydrogen multilayered target H/T-D{sub 2} and muonic X-ray yields in ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Gheisari, R., E-mail: gheisari@pgu.ac.ir [Physics Department, Persian Gulf University, Bushehr 75169 (Iran, Islamic Republic of)

    2011-12-21

    This paper extends applications of the multilayered solid target H/T-D{sub 2}, which is kept at 3 K. The time evolutions of muonic tritium atoms ({mu}t) are obtained, by taking into account {mu}t production rate at different places of deuterium material. The apparatus H/T-D{sub 2} can be used for checking nuclear properties of implanted ions, which take part at muon transfer. Electromagnetic X-rays are generated by muon atomic transitions. The muonic X-ray transition energies are strongly affected by the size of nuclei. Here, a solid hydrogen-tritium (H/T) with a Almost-Equal-To 1 mm thick is used for {mu}t production. For ion implantation, the required amount of deuterium material is determined to be about 3.2 {mu}m. Moreover, the muonic X-ray yields are estimated and compared with those of the arrangement H/T-D{sub 2}. While the present target requires argon ion beam intensity nearly a factor of 2 times smaller; gives a relatively higher X-ray yield (15% enhancement per hour) at the energy 644 keV with the detection efficiency of Almost-Equal-To 1%.

  14. Muonic-hydrogen molecular bound states, quasibound states, and resonances in the Born-Oppenheimer approximation

    International Nuclear Information System (INIS)

    Jackson, J.D.

    1994-01-01

    The Born-Oppenheimer approximation is used as an exploratory tool to study bound states, quasibound states, and scattering resonances in muon (μ)--hydrogen (x)--hydrogen (y) molecular ions. Our purpose is to comment on the existence and nature of the narrow states reported in three-body calculations, for L=0 and 1, at approximately 55 eV above threshold and the family of states in the same partial waves reported about 1.9 keV above threshold. We first discuss the motivation for study of excited states beyond the well-known and well-studied bound states. Then we reproduce the energies and other properties of these well-known states to show that, despite the relatively large muon mass, the Born-Oppenheimer approximation gives a good, semiquantitative description containing all the essential physics. Born-Oppenheimer calculations of the s- and p-wave scattering of d-(dμ), d-(tμ), and t-(tμ) are compared with the accurate three-body results, again with general success. The places of disagreement are understood in terms of the differences in location of slightly bound (or unbound) states in the Born-Oppenheimer approximation compared to the accurate three-body calculations

  15. Cascade processes in kaonic and muonic atoms

    International Nuclear Information System (INIS)

    Faifman, M.P.; Men'shikov, L.I.

    2003-01-01

    Cascade processes in exotic (kaonic and muonic) hydrogen/deuterium have been studied with the quantum-classical Monte Carlo code (QCMC) developed for 'ab initio' - calculations. It has been shown that the majority of kaonic hydrogen atoms during cascade are accelerated to high energies E ∼ 100 eV, which leads to a much lower value for the calculated yields Y of x-rays than predicted by the 'standard cascade model'. The modified QCMC scheme has been applied to the study of the cascade in μp and μd muonic atoms. A comparison of the calculated yields for K-series x-rays with experimental data directly indicates that the molecular structure of the hydrogen target and new types of non-radiative transitions are essential for the light muonic atoms, while they are negligible for heavy (kaonic) atoms. These processes have been considered and estimates of their probabilities are presented. (author)

  16. Improved adiabatic calculation of muonic-hydrogen-atom cross sections. I. Isotopic exchange and elastic scattering in asymmetric collisions

    International Nuclear Information System (INIS)

    Cohen, J.S.; Struensee, M.C.

    1991-01-01

    The improved adiabatic representation is used in calculations of elastic and isotopic-exchange cross sections for asymmetric collisions of pμ, dμ, and tμ with bare p, d, and t nuclei and with H, D, and T atoms. This formulation dissociates properly, correcting a well-known deficiency of the standard adiabatic method for muonic-atom collisions, and includes some effects at zeroth order that are normally considered nonadiabatic. The electronic screening is calculated directly and precisely within the improved adiabatic description; it is found to be about 30% smaller in magnitude than the previously used value at large internuclear distances and to deviate considerably from the asymptotic form at small distances. The reactance matrices, needed for calculations of molecular-target effects, are given in tables

  17. Spectroscopy of muonic atoms and the proton radius puzzle

    Science.gov (United States)

    Antognini, Aldo

    2017-09-01

    We have measured several 2 S -2 P transitions in muonic hydrogen (μp), muonic deuterium (μd) and muonic helium ions (μ3He, μ4He). From muonic hydrogen we extracted a proton charge radius 20 times more precise than obtained from electron-proton scattering and hydrogen high-precision laser spectroscopy but at a variance of 7 σ from these values. This discrepancy is nowadays referred to as the proton radius puzzle. New insight has been recently provided by the first determination of the deuteron charge radius from laser spectroscopy of μd. The status of the proton charge radius puzzle including the new insights obtained by μd spectroscopy will be discussed. Work supported by the Swiss National Science Foundation SNF-200021-165854 and the ERC CoG. #725039.

  18. Deciphering the "chemical" nature of the exotic isotopes of hydrogen by the MC-QTAIM analysis: the positively charged muon and the muonic helium as new members of the periodic table.

    Science.gov (United States)

    Goli, Mohammad; Shahbazian, Shant

    2014-04-14

    This report is a primarily survey on the chemical nature of some exotic species containing the positively charged muon and the muonic helium, i.e., the negatively charged muon plus helium nucleus, as exotic isotopes of hydrogen, using the newly developed multi-component quantum theory of atoms in molecules (MC-QTAIM) analysis, employing ab initio non-Born-Oppenhiemer wavefunctions. Accordingly, the "atoms in molecules" analysis performed on various asymmetric exotic isotopomers of the hydrogen molecule, recently detected experimentally [Science, 2011, 331, 448], demonstrates that both the exotic isotopes are capable of forming atoms in molecules and retaining the identity of hydrogen atoms. Various derived properties of atomic basins containing the muonic helium cast no doubt that apart from its short life time, it is a heavier isotope of hydrogen while the properties of basins containing the positively charged muon are more remote from those of the orthodox hydrogen basins, capable of appreciable donation of electrons as well as large charge polarization. However, with some tolerance, they may also be categorized as hydrogen basins though with a smaller electronegativity. All in all, the present study also clearly demonstrates that the MC-QTAIM analysis is an efficient approach to decipher the chemical nature of species containing exotic constituents, which are difficult to elucidate by experimental and/or alternative theoretical schemes.

  19. Method of removing hydrogen sulphide from hot gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Yumura, M.

    1987-12-22

    Hydrogen sulphide can be removed from hot gas mixtures by contacting the hot gas mixture at temperatures in the range of 500-900/sup 0/C with an adsorbent consisting of managanese nodules. The nodules may contain additional calcium cations. In sulphided form, the nodules are catalytically active for hydrogen sulphide decomposition to produce hydrogen. Regeneration of the adsorbent can be accomplished by roasting in an oxidizing atmosphere. The nodules can be used to treat gaseous mixtures containing up to 20% hydrogen sulfide, for example, gases produced during pyrolysis, cracking, coking, and hydrotreating processes. Experiments using the processes described in this patent are also outlined. 6 tabs.

  20. Experimental search for muonic photons

    CERN Document Server

    Vilain, P; Beyer, R; Flegel, Wilfried; Mouthuy, T; Øverås, H; Panman, J; Rozanov, A N; Winter, Klaus; Zacek, G; Zacek, V; Büsser, F W; Foos, C; Gerland, L; Layda, T; Niebergall, F; Rädel, G; Stähelin, P; Voss, T; Favart, D; Grégoire, G; Knoops, E; Lemaître, V; Gorbunov, P; Grigoriev, E A; Ilyin, V A; Khovanskii, V D; Maslennikov, A M; Okun, Lev Borisovich; Lippich, W; Nathaniel, A; Staude, A; Vogt, J; Cocco, A G; Ereditato, A; Fiorillo, G; Marchetti-Stasi, F; Palladino, Vittorio; Strolin, P; Capone, A; De Pedis, D; Dore, U; Frenkel-Rambaldi, A; Loverre, P F; Macina, Daniela; Piredda, G; Santacesaria, R; Di Capua, E; Ricciardi, S; Saitta, B; Akkus, B; Arik, E; Serin-Zeyrek, M; Sever, R; Tolun, P; Hiller, K; Nahnhauer, R; Roloff, H

    1998-01-01

    We report new limits on the production of muonic photons in the CERN neutrino beam. The results are based on the analysis of neutrino production of dimuons in the CHARM II detector. A $90\\%$ CL limit on the coupling constant of muonic photons, $\\alpha_{\\mu} / \\alpha < (1.5 \\div 3.2) \\times10^{-6}$ is derived for a muon neutrino mass in the range $m_{\

  1. Energy levels of muonic atoms

    International Nuclear Information System (INIS)

    Borie, E.; Rinker, G.A.

    1982-01-01

    The theory of muonic atoms is a complex and highly developed combination of nuclear physics, atomic physics, and quantum electrodynamics. Perhaps nowhere else in microscopic physics are such diverse branches so intimately intertwined and yet readily available for precise experimental verification or rejection. In the present review we summarize and discuss all of the most important components of muonic atom theory, and show in selected cases how this theory meets experimental measurements

  2. Erosion of graphite surface exposed to hot supersonic hydrogen gas

    Science.gov (United States)

    Sharma, O. P.

    1972-01-01

    A theoretical model based on laminar boundary layer flow equations was developed to predict the erosion rate of a graphite (AGCarb-101) surface exposed to a hot supersonic stream of hydrogen gas. The supersonic flow in the nozzle outside the boundary layer formed over the surface of the specimen was determined by assuming one-dimensional isentropic conditions. An overall surface reaction rate expression based on experimental studies was used to describe the interaction of hydrogen with graphite. A satisfactory agreement was found between the results of the computation, and the available experimental data. Some shortcomings of the model and further possible improvements are discussed.

  3. Muonic atoms with vacant electron shells

    International Nuclear Information System (INIS)

    Bacher, R.; Gotta, D.; Simons, L.M.; Missimer, J.; Mukhopadhyay, N.C.

    1985-01-01

    We show that the cascade in muonic atoms with Z<20 ejects sufficient atomic electrons to ionize an isolated muonic atom completely. In gases, the rates with which electrons refill the atomic shell can be accurately deduced from measured and calculated electron transfer cross sections. Thus, we can conclude that completely ionized muonic atoms can be prepared in gases, and that they remain isolated for long enough times at attainable pressures to facilitate studies of fundamental interactions in muonic atoms

  4. Tests of Hercules/Ultramet CVD coatings in hot hydrogen

    International Nuclear Information System (INIS)

    Vanier, P.E.; Barletta, R.E.; Svandrlik, J.; Adams, J.

    1992-01-01

    The effort by Hercules and Ultramet to produce CVD NbC coatings, which protect carbon-carbon substrates from hot hydrogen, has had some success but with some limitations. The coatings increase the survival time at atmospheric pressure and low flow rate of hydrogen by about a factor of 40 over uncoated graphite at 3000 K. However, the grain structure is not stable at these temperatures, and after about 10--20 minutes, the coating is subject to rapid degradation by spalling in visible chunks. Further experiments would have to be performed to determine the effects of higher pressures and flow rates, for it is not clear how these factors would affect the survival time, considering that one of the main failure mechanisms is independent of the atmosphere

  5. Materials and fabrication processes for operation in hot hydrogen

    International Nuclear Information System (INIS)

    Tuffias, R.H.; Duffy, A.J.; Arrieta, V.M.; Abrams, W.M.; Benander, R.E.

    1997-01-01

    Operation in hot (2500 endash 3000 K) hydrogen severely limits the choice of structural materials. Rhenium is nonreactive with and has low permeability to hydrogen, and has sufficient strength up to 2800 K. Carbon, in the form of graphite or carbon composites, has excellent high temperature strength but reacts with hydrogen to form methane at a rapid rate above 2000 K. The carbides of zirconium, niobium, hafnium, and tantalum are nonreactive with and have low permeability to hydrogen, but they can be reliably fabricated only in the form of coatings. In order to demonstrate the Integrated Solar Upper Stage (ISUS) solar-thermal propulsion concept, rhenium and rhenium-coated graphite were chosen as the structural materials for the receiver-absorber-converter (RAC) component of the ISUS system. Several methods were investigated for fabricating the rhenium parts and coatings, with chemical vapor deposition (CVD) and Ultramet chosen as the most likely process and company for success. The CVD or rhenium and other refractory materials were thus applied to the ISUS program for fabrication of the RAC subsystem. copyright 1997 American Institute of Physics

  6. Muonium and neutral muonic helium

    International Nuclear Information System (INIS)

    Orth, H.

    1981-01-01

    In this brief article the current status on muonium spectroscopy with emphasis on recent developments will be summarized. The experimental and theoretical progress of the muonic helium atom will be reviewed. Future directions in this field of research will be discussed. (orig./HSI)

  7. Hot vacuum outgassing to ensure low hydrogen content in MOX fuel pellets for thermal reactors

    International Nuclear Information System (INIS)

    Majumdar, S.; Nair, M.R.; Kumar, Arun

    1983-01-01

    Hot vacuum outgassing treatment to ensure low hydrogen content in Mixed Oxide Fuel (MOX) pellets for thermal reactors has been described. Hypostoichiometric sintered MOX pellets retain more hydrogen than UO 2 pellets. The hydrogen content further increases with the addition of admixed lubricant and pore formers. However, low hydrogen content in the MOX pellets can be ensured by a hot vacuum outgassing treatment at a temperature between 773K to 823K for 2 hrs. (author)

  8. Nuclear excitation in muonic gold

    CERN Document Server

    Robert Tissot, B; Debrunner, P; Engfer, R; Link, R; Schellenberg, L; Schneuwly, H; Walter, H K

    1973-01-01

    Energies and intensities of muonic X-rays in gold were measured at the CERN muon channel with an experimental set-up as described by Backe et al. (1972). The 2p-1s and 3d-2p transitions could only be analysed taking into account beside the static quadrupole interaction a dynamical hyperfine interaction of the 2p states, which leads to an excitation of the first four nuclear levels. The dynamical hyperfine interaction was calculated using the core excitation model (de Shalit, (1961)). (0 refs).

  9. Exotic atoms: Hadronic and muonic atoms 1969--1997. Technical progress report, February 1, 1996--August 31, 1997

    International Nuclear Information System (INIS)

    Kunselman, R.

    1997-01-01

    Since this is a terminal progress-report it is a synopsis over the total time of the grant. The author has utilized exotic hadronic and muonic atoms as tools to access information concerning questions to do with particle, nuclear, and atomic physics. The information has answered fundamental questions about lepton conservations, quark models, tests of the CPT theorem, QED energies, and nuclear structure. The present experiments involve reactions with a variety of hydrogen isotopic mixtures to form solid targets to produce muonic hydrogen isotope atoms. The method relies on muon capture by a proton and transfer of the muon from the proton to a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections of the Ramsauer-Townsend effect, and are emitted from the surface of the layer and escape into a vacuum region. A second solid hydrogen isotopic target is produced downstream on which the muonic hydrogen atom can react and the time of flight measured

  10. Hydrogen in hot subdwarfs formed by double helium white dwarf mergers

    OpenAIRE

    Hall, Philip D.; Jeffery, C. Simon

    2016-01-01

    Isolated hot subdwarfs might be formed by the merging of two helium-core white dwarfs. Before merging, helium-core white dwarfs have hydrogen-rich envelopes and some of this hydrogen may survive the merger. We calculate the mass of hydrogen that is present at the start of such mergers and, with the assumption that hydrogen is mixed throughout the disrupted white dwarf in the merger process, estimate how much can survive. We find a hydrogen mass of up to about $2 \\times 10^{-3}\\,\\mathrm{M}_{\\o...

  11. Imaging the Extended Hot Hydrogen Exosphere at Mars to Determine the Water Escape Rate

    Science.gov (United States)

    Bhattacharyya, Dolon

    2017-08-01

    ACS SBC imaging of the extended hydrogen exosphere of Mars is proposed to identify the hot hydrogen population present in the exosphere of Mars. Determining the characteristics of this population and the underlying processes responsible for its production are critical towards constraining the escape flux of H from Mars, which in turn is directly related to the water escape history of Mars. Since the hot atoms appear mainly at high altitudes, these observations will be scheduled when Mars is far from Earth allowing us to image the hot hydrogen atoms at high altitudes where they dominate the population. The altitude coverage by HST will extend beyond 30,000 km or 8.8 Martian radii in this case, which makes it perfect for this study as orbiting spacecraft remain at low altitudes (MAVEN apoapse is 6000 km) and cannot separate hot atoms from the thermal population at those altitudes. The observations will also be carried out when Mars is near aphelion, the atmospheric temperature is low, and the thermal population has a small scale height, allowing the clear characterization of the hot hydrogen layer. Another advantage of conducting this study in this cycle is that the solar activity is near its minimum, allowing us to discriminate between changes in the hot hydrogen population from processes taking place within the atmosphere of Mars and changes due to external drivers like the solar wind, producing this non-thermal population. This proposal is part of the HST UV initiative.

  12. The effect of moderators on the reactions of hot hydrogen atoms with methane

    CERN Document Server

    Estrup, Peder J.

    1960-01-01

    The reaction of recoil tritium with methane has been examined in further detail. The previous hypothesis that this system involves a hot displacement reaction of high kinetic energy hydrogen to give CH$_{3}$T, CH$_{2}$T and HT is confirmed. The effect of moderator on this process is studied by the addition of noble gases. As predicted these gases inhibit the hot reaction action, their efficiency in this respect being He > Ne > A > Se. The data are quantitatively in accord with a theory of hot atom kinetics. The mechanism of the hot displacement process is briefly discussed.

  13. Lamb shift and fine structure at n =2 in a hydrogenlike muonic atom with the nuclear spin I =0

    Science.gov (United States)

    Korzinin, Evgeny Yu.; Shelyuto, Valery A.; Ivanov, Vladimir G.; Karshenboim, Savely G.

    2018-01-01

    The paper is devoted to the Lamb shift and fine structure in a hydrogenlike muonic atom with a spinless nucleus up to the order α5m with all the recoil corrections included. Enhanced contributions of a higher order are also considered. We present the results on the pure QED contribution and on the finite-nuclear-size contribution, proportional to RN2, with the higher-order corrections included. We also consider the consistency of the pure QED theory and the evaluation of the nuclear-structure effects. Most of the QED theory is the same as the theory for the case of the nuclear spin 1/2. Additional nuclear-spin-dependent terms are considered in detail. The issue of the difference for the theories with a spinor nucleus and a scalar one is discussed for the recoil contributions in the order (Zα ) 4m ,α (Zα ) 4m , and (Zα ) 5m . The numerical results are presented for the muonic atoms with two lightest scalar nuclei, helium-4 and beryllium-10. We compare the theory of those muonic atoms with theory for the muonic hydrogen. Some higher-order finite-nuclear-size corrections for the Lamb shift in muonic hydrogen are revisited.

  14. Muonic Chemistry in Condensed Matter

    CERN Multimedia

    2002-01-01

    When polarized muons (@m|+) stop in condensed matter, muonic atoms are formed in the final part of their range, and direct measurements of the @m|+-spin polarization are possible via the asymmetric decay into positrons. The hyperfine interaction determines the characteristic precession frequencies of the @m|+ spin in muonium, @w(Mu). Such frequencies can be altered by the interactions of the muonium's electron spin with the surrounding medium. The measurement of @w(Mu) in a condensed system is known often to provide unique information regarding the system. \\\\ \\\\ In particular, the use of muonium atoms as a light isotope of the simple reactive radical H|0 allows the investigation of fast reactions of radicals over a typical time scale 10|-|9~@$<$~t~@$<$~10|-|5~sec, which is determined by the instrumental resolution at one end and by the @m|+ lifetime at the other. \\\\ \\\\ In biological macromolecules transient radicals, such as the constituents of DNA itself, exist on a time scale of sub-microseconds, acco...

  15. Nuclear polarization shifts in light muonic atoms

    International Nuclear Information System (INIS)

    Rosenfelder, R.

    1983-01-01

    A consistent nonrelativistic expression for the energy shift in muonic atoms due to second-order processes is derived under the assumption that the muon is weakly bound. The transverse contribution is shown to be finite only if the two-photon ('seagull') amplitude is taken into account as required by gauge invariance. Numerical results are presented for muonic 12 C using a recently developed model for the nuclear response function. The total transverse contributions to the energy shift are found to be small although dependent to some extent on the detailed high-momentum behaviour of the seagull term. (orig.)

  16. Experimental determination of differential cross-sections of muonic neutrinos and muonic antineutrinos interactions

    International Nuclear Information System (INIS)

    Lutz, Anne-Marie.

    1975-05-01

    The experimental determination of muonic neutrinos and muonic antineutrinos differential cross-sections by the analysis of pictures taken in the CERN Gargamelle heavy liquid bubble chamber is presented. The methods used to solve experimental difficulties (muon identification, hadronic energy determination) and the errors on the experimental distributions are explained in detail. Then, the structure functions in charge changing interactions of neutrinos and antineutrinos are analyzed and interpreted in terms of parton distribution inside the nucleon [fr

  17. Solid adsorbents for removal of hydrogen sulphide from hot gas

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Yumura, Motoo

    1986-04-01

    A wide range of solids have been tested as potential adsorbents for H/sub 2/S removal from hot gas. These solids can be divided into two main groups, i.e., the adsorbents containing alkaline earth metals and those containing transition metals. Among the former, calcium oxide and naturally occurring materials such as limestone, dolomite and calcium silicate have attracted a great deal of attention. The adsorbents of the second group include iron oxide alone or in combination with some supports, zinc oxide, zinc ferrite and manganese oxide. The materials containing both the alkaline earth metals and transition metals, e.g., manganese nodules, fly ash and the reject from the aluminium industry (red mud) have been evaluated as well.

  18. Spectroscopy of vibrationally hot molecules: Hydrogen cyanide and acetylene

    International Nuclear Information System (INIS)

    Jonas, D.M.

    1992-01-01

    An efficient formula for calculating nuclear spin statistical weights is presented. New experimental methods to distinguish electric and magnetic multipole transitions are proposed and used to prove that the formaldehyde A - X 0-0 transition is a magnetic dipole transition. HIgh resolution vacuum ultraviolet studies of the A → X fluorescence excitation spectrum of hydrogen cyanide (HCN) have: (i) determined that only the (0,1,0) vibrational level of the HCN A-state has a sufficiently long fluorescence lifetime to be suitable for Stimulated Emission Pumping (SEP) studies; and (ii) measured the electric dipole moment of the A-state. Several transitions in the hydrogen cyanide A → X SEP spectrum are shown to be due to the axis-switching mechanism. From a Franck-Condon plot of the intensities and a comparison between sums of predicted rotational constants and sums of observed rotational constants, all of the remaining transitions in the SEP spectrum can be securly assigned. Two weak resonances; a 2:3 CH:CN stretch Fermi resonance and a 6:2 bend:CN stretch resonance appear in the SEP spectrum. Excitation of the CH stretching vibration is predicted and shown to be entirely absent, apart from resonances, in the HCN SEP spectrum. A → X SEP spectra of acetylene (HCCH) near E VIB = 7,000 cm -1 display a wealth of strong and fully assignable anharmonic resonances and forbidden rotational transitions. It is proved that Darling-Dennison resonance between the cis and trans bending vibrations is the crucial first step in a series of anharmonic resonances which can transfer nearly all the vibrational energy out of the initial CC stretch/trans-bend excitation at high vibrational energy. Secondary steps in the vibrational energy flow are vibrational-l-resonance and the '2345' Fermi resonance. For short times, the vibrational energy redistribution obeys very restrictive rules

  19. Hot wire deposited hydrogenated amorphous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

  20. Electronic isotope shifts, muonic atoms, and electron scattering

    International Nuclear Information System (INIS)

    Shera, E.B.

    1982-01-01

    The roles of electronic isotope shift, muonic atom, and electron scattering experiments in studying the nuclear charge distribution are discussed in terms of the potentials of each probe. Barium isotope shift data are presented as an example of a combined muonic-optical analysis and the results are compared with droplet and IBA model predictions. A survey of muonic and (e,e) results is presented with emphasis on shell-structure related features

  1. Toward a muon-specific electronic structure theory: effective electronic Hartree-Fock equations for muonic molecules.

    Science.gov (United States)

    Rayka, Milad; Goli, Mohammad; Shahbazian, Shant

    2018-02-07

    An effective set of Hartree-Fock (HF) equations are derived for electrons of muonic systems, i.e., molecules containing a positively charged muon, conceiving the muon as a quantum oscillator, which are completely equivalent to the usual two-component HF equations used to derive stationary states of the muonic molecules. In these effective equations, a non-Coulombic potential is added to the orthodox coulomb and exchange potential energy terms, which describes the interaction of the muon and the electrons effectively and is optimized during the self-consistent field cycles. While in the two-component HF equations a muon is treated as a quantum particle, in the effective HF equations it is absorbed into the effective potential and practically transformed into an effective potential field experienced by electrons. The explicit form of the effective potential depends on the nature of muon's vibrations and is derivable from the basis set used to expand the muonic spatial orbital. The resulting effective Hartree-Fock equations are implemented computationally and used successfully, as a proof of concept, in a series of muonic molecules containing all atoms from the second and third rows of the Periodic Table. To solve the algebraic version of the equations muon-specific Gaussian basis sets are designed for both muon and surrounding electrons and it is demonstrated that the optimized exponents are quite distinct from those derived for the hydrogen isotopes. The developed effective HF theory is quite general and in principle can be used for any muonic system while it is the starting point for a general effective electronic structure theory that incorporates various types of quantum correlations into the muonic systems beyond the HF equations.

  2. Nuclear polarization in muonic 208Pb

    International Nuclear Information System (INIS)

    Haga, Akihiro; Tanaka, Yasutoshi; Horikawa, Yataro

    2002-01-01

    We calculate nuclear-polarization energy shifts in muonic 208 Pb. We employ a relativistic field-theoretical calculation and evaluate the ladder, cross, and seagull terms of the two-photon exchange diagrams in both the Feynman and Coulomb gauges. Gauge independence is very well satisfied with the calculated nuclear-polarization energies. Using these results, we analyze fine-structure splitting energies of muonic 208 Pb because of the presence of the persisting discrepancies between experiment and calculation. The present nuclear-polarization energies explain about half of the anomaly in the Δ2p fine-structure splitting energy, and only one-fourth of the anomaly in the Δ3p fine-structure splitting energy

  3. Hot vacuum extraction-isotopic dilution mass spectrometry for determination of hydrogen isotopes in zircaloys

    International Nuclear Information System (INIS)

    Shi, Y.; Leeson, P.K.; Wilkin, D.; Britton, A.; Macleod, R.

    2016-01-01

    A hot vacuum extraction-isotope dilution mass spectrometry (HVE-IDMS) was studied for determination of hydrogen isotopes in zirconium metal and alloys as nuclear reactor materials. A theoretical assessment of the completeness of the extraction of hydrogen isotopes under the chosen condition was carried out based on the hydrogen and deuterium solubility data for zirconium. The optimal isotopic spiking condition for conventional IDMS was further explored for the special case IDMS where the isotope abundance of the samples is varied and non-natural. Applying the optimal conditions, the accurate IDMS determination was realized. The agreement between the measured values and the certified or prepared values of standard reference materials and homemade standard materials validate the method developed. (author)

  4. Performance of carbon-based hot frit substrates: I, Low pressure helium and hydrogen testing

    International Nuclear Information System (INIS)

    Barletta, R.; Adams, J.; Svandrlik, J.; Powell, J.R.

    1993-07-01

    The performance of various carbon-based materials in flowing, high-temperature helium and hydrogen is described. These materials which are candidate hot frit substrates for possible application in a PBR include various grades of graphite, carbon-carbon and vitreous carbon. Vitreous carbon showed extremely good performance in helium, while that of the various graphite grades was quite variable and, in some cases, poor. Purified grades performed better than unpurified grades, but in all cases large sample-to-sample variations in weight loss were observed. For carbon-carbon samples, the performance was intermediate. Since the weight loss in these samples was in large measure due to the loss of the densification media, improvements in the performance of carbon-carbon may be possible. With respect to the performance in hydrogen, high weight losses were observed, re-enforcing the need for coating carbon-based materials for service in a flowing hydrogen environment

  5. Semi-analytic approach to higher-order corrections in simple muonic bound systems: vacuum polarization, self-energy and radiative-recoil

    Energy Technology Data Exchange (ETDEWEB)

    Jentschura, U.D. [Department of Physics, Missouri University of Science and Technology, Rolla MO65409 (United States); Institut fur Theoretische Physik, Universitat Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); Wundt, B.J. [Department of Physics, Missouri University of Science and Technology, Rolla MO65409 (United States)

    2011-12-15

    The current discrepancy of theory and experiment observed recently in muonic hydrogen necessitates a reinvestigation of all corrections to contribute to the Lamb shift in muonic hydrogen ({mu}H), muonic deuterium ({mu}D), the muonic {sup 3}He ion (denoted here as {mu}{sup 3}He{sup +}), as well as in the muonic {sup 4}He ion ({mu}{sup 4}He{sup +}). Here, we choose a semi-analytic approach and evaluate a number of higher-order corrections to vacuum polarization (VP) semi-analytically, while remaining integrals over the spectral density of VP are performed numerically. We obtain semi-analytic results for the second-order correction, and for the relativistic correction to VP. The self-energy correction to VP is calculated, including the perturbations of the Bethe logarithms by vacuum polarization. Sub-leading logarithmic terms in the radiative-recoil correction to the 2S-2P Lamb shift of order {alpha}(Z{alpha}){sup 5{mu}3}ln(Z{alpha})/(m{sub {mu}mN}) where {alpha} is the fine structure constant, are also obtained. All calculations are nonperturbative in the mass ratio of orbiting particle and nucleus. (authors)

  6. Semi-analytic approach to higher-order corrections in simple muonic bound systems: vacuum polarization, self-energy and radiative-recoil

    International Nuclear Information System (INIS)

    Jentschura, U.D.; Wundt, B.J.

    2011-01-01

    The current discrepancy of theory and experiment observed recently in muonic hydrogen necessitates a reinvestigation of all corrections to contribute to the Lamb shift in muonic hydrogen (μH), muonic deuterium (μD), the muonic 3 He ion (denoted here as μ 3 He + ), as well as in the muonic 4 He ion (μ 4 He + ). Here, we choose a semi-analytic approach and evaluate a number of higher-order corrections to vacuum polarization (VP) semi-analytically, while remaining integrals over the spectral density of VP are performed numerically. We obtain semi-analytic results for the second-order correction, and for the relativistic correction to VP. The self-energy correction to VP is calculated, including the perturbations of the Bethe logarithms by vacuum polarization. Sub-leading logarithmic terms in the radiative-recoil correction to the 2S-2P Lamb shift of order α(Zα) 5 μ 3 ln(Zα)/(m μ m N ) where α is the fine structure constant, are also obtained. All calculations are nonperturbative in the mass ratio of orbiting particle and nucleus. (authors)

  7. Three-Body Protonium Formation in a Collision Between a Slow Antiproton ({barp}) and Muonic Hydrogen: {H_{μ}}—Low Energy {barp + (p μ^-)_{1s} → (barp p)_{1s} + μ^-} Reaction

    Science.gov (United States)

    Sultanov, Renat A.; Guster, D.; Adhikari, S. K.

    2015-12-01

    A bound state of a proton, p, and its counterpart antiproton, {barp}, is a protonium atom {Pn = (barp p)}. The following three-charge-particle reaction: {barp +(p μ^-)_{1s} → (barp {p})_{1s} + μ^-} is considered in this work, where {μ^-} is a muon. At low-energies muonic reaction {Pn} can be formed in the short range state with α = 1 s or in the first excited state: α = 2 s/2 p, where {barp} and p are placed close enough to each other and the effect of the {barp}-p nuclear interaction becomes significantly stronger. The cross sections and rates of the Pn formation reaction are computed in the framework of a few-body approach based on the two-coupled Faddeev-Hahn-type (FH-type) equations. Unlike the original three-body Faddeev method the FH-type equation approach is formulated in terms of only two but relevant components: {{Ψ}_1} and {Ψ_2}, of the system's three-body wave function {Ψ}, where {{Ψ}={Ψ}_1+{Ψ}_2}. In order to solve the FH-type equations {Ψ_1} is expanded in terms of the input channel target eigenfunctions, i.e. in this work in terms of the {({p} μ^-)} eigenfunctions. At the same time {Ψ_2} is expanded in terms of the output channel two-body wave function, that is in terms of the protonium {(bar{{p}} {p})} eigenfunctions. A total angular momentum projection procedure is performed, which leads to an infinite set of one-dimensional coupled integral-differential equations for unknown expansion coefficients.

  8. Ignitability of hydrogen/oxygen/diluent mixtures in the presence of hot surfaces

    International Nuclear Information System (INIS)

    Kumar, R.K.; Koroll, G.W.

    1995-01-01

    In the licensing process for CANDU nuclear power stations it is necessary to demonstrate tolerance to a wide range of low-probability accidents. These include loss of moderator accidents that may lead to the formation of flammable mixtures of deuterium, oxygen, helium, and steam in the reactor calandria vessel. Uncovered adjuster or control rods are considered as possible sources of ignition when a flammable mixture is present. A knowledge of the minimum hot-surface temperature required for ignition is important in assessing the reactor safety. These hot surface temperatures were measured using electrically heated adjuster rod simulators in a large spherical vessel (2.3-m internal diameter). Whereas the effects of geometry on ignition temperature were studied in the large-scale apparatus, some of the effects, such as those produced by a strong radiation field, were studied using a small-scale apparatus. Investigations carried our over a range of hydrogen and diluent concentrations indicated that, although the ignition temperatures were fairly insensitive to the hydrogen concentration, they were strongly affected by the presence of steam The addition of 30% steam to a dry combustible mixture increased the minimum surface temperature required for ignition by approximates 100 degrees C of the diluents investigated, steam had the most effect on ignition. The effect of initial temperature of the mixture on the ignition temperature was small, whereas the effect of initial pressure was significant. The effect of substituting deuterium for hydrogen on ignition temperature was small. The effect of a high-intensity gamma-radiation field on the minimum hot-surface temperature required for ignition was investigated using a 2-dm 3 ignition vessel placed in a linear accelerator. Radiation had no measurable effect on ignition temperature

  9. Lamb shift in the muonic deuterium atom

    Energy Technology Data Exchange (ETDEWEB)

    Krutov, A. A.; Martynenko, A. P. [Samara State University, Pavlov street 1, 443011, Samara (Russian Federation); Samara State University, Pavlov Street 1, 443011, Samara, Russia and Samara State Aerospace University named after academician S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation)

    2011-11-15

    We present an investigation of the Lamb shift (2P{sub 1/2}-2S{sub 1/2}) in the muonic deuterium ({mu}D) atom using the three-dimensional quasipotential method in quantum electrodynamics. The vacuum polarization, nuclear-structure, and recoil effects are calculated with the account of contributions of orders {alpha}{sup 3}, {alpha}{sup 4}, {alpha}{sup 5}, and {alpha}{sup 6}. The results are compared with earlier performed calculations. The obtained numerical value of the Lamb shift at 202.4139 meV can be considered a reliable estimate for comparison with forthcoming experimental data.

  10. Study on a negative hydrogen ion source with hot cathode arc discharge.

    Science.gov (United States)

    Lin, S H; Fang, X; Zhang, H J; Qian, C; Ma, B H; Wang, H; Li, X X; Zhang, X Z; Sun, L T; Zhang, Z M; Yuan, P; Zhao, H W

    2014-02-01

    A negative hydrogen (H(-)) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H(-) beam with ɛ N, RMS = 0.08 π mm mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of I(e(-))/I(H(-)) were experimentally studied. The discussion on the result, and opinions to improve the source were given.

  11. Calculation of Photonic decay width for meta-stable muonic symmetric ion in adiabatic representation method

    International Nuclear Information System (INIS)

    Gheisari, R.; Eskandari, M. R.

    2006-01-01

    Meta-stable symmetric ions ppμ * and ddμ * are formed in the collisions of the excited muonic atoms with the hydrogen isotopes. By dissociation of them, the muon transfers from 2s to 1s via the new channels. Considering the quantum electrodynamics field and employing the new wave functions, the matrix elements are simply integrated. In this method using the adiabatic representations, the photo-decay widths for the some of ppμ * and ddμ * states are variationally calculated. The decay rates for X-ray productions of the similar states are approximately same.

  12. Update on nuclear structure effects in light muonic atoms

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Oscar Javier, E-mail: javierh@triumf.ca; Dinur, Nir Nevo; Ji, Chen; Bacca, Sonia [TRIUMF (Canada); Barnea, Nir [The Hebrew University, Racah Institute of Physics (Israel)

    2016-12-15

    We present calculations of the nuclear structure corrections to the Lamb shift in light muonic atoms, using state-of-the-art nuclear potentials. We outline updated results on finite nucleon size contributions.

  13. Preliminary design analysis of hot gas ducts and a intermediate heat exchanger for the nuclear hydrogen reactor

    International Nuclear Information System (INIS)

    Song, K. N.; Kim, Y. W.

    2008-01-01

    Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a nuclear hydrogen system by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. Primary and secondary hot gas ducts with coaxial double tubes and are key components connecting a reactor pressure vessel and a intermediate heat exchanger for the nuclear hydrogen system. In this study, preliminary design analyses on the hot gas ducts and the intermediate heat exchanger were carried out. These preliminary design activities include a preliminary design on the geometric dimensions, a preliminary strength evaluation, thermal sizing, and an appropriate material selection

  14. Hyperfine structure of muonic lithium ions

    Directory of Open Access Journals (Sweden)

    Alexey P. Martynenko

    2015-06-01

    Full Text Available On the basis of perturbation theory in fine structure constant $\\alpha$ and the ratio of electron to muon masses we calculate recoil corrections of order $\\alpha^4 (M_e/M_\\mu$, $\\alpha^4 (M_e/M_\\mu^2\\ln(M_e/M_\\mu$, $\\alpha^4 (M_e/M_\\mu^2$, $\\alpha^5(m_e/m_\\mu\\ln(m_e/m_\\mu$ to hyperfine splitting of the ground state in muonic lithium ions $(\\mu e ^6_3\\mathrm{Li}^+$ and $(\\mu e ^7_3\\mathrm{Li}^+$. We obtain total results for the ground state small hyperfine splittings in $(\\mu e ^6_3\\mathrm{Li}^+$ $\\Delta\

  15. The rise of hot gases resulting from hydrogen combustion at a tritium recovery plant

    International Nuclear Information System (INIS)

    Selander, W.N.

    1981-10-01

    An accidental release of hydrogen isotopes at a proposed tritium recovery plant may result in a fire or explosion. In this report estimates are given for the initial transient rise and final height of the cloud of hot gasses which results from various modes of combustion. The radiation dose equivalent caused by the downwind passage of the tritium-bearing cloud is estimated to be less than 100 mrem in any mode of combustion or weather condition. The model used for calculating the final height of the cloud depends on an entrainment assumption, and the low-density cloud loses energy by entrainment at a slower rate than in conventional atmospheric processes. Consequently, the estimated final cloud height is conservative, and, therefore, the actual radiation dose equivalent would be lower than predicted

  16. (F)UV Spectral Analysis of Hot, Hydrogen-Rich Central Stars of Planetary Nebulae

    Science.gov (United States)

    Ziegler, M.; Rauch, T.; Werner, K.; Kruk, J. W.

    2010-11-01

    Metal abundances of CSPNe are not well known although they provide important constraints on AGB nucleosynthesis. We aim to determine metal abundances of two hot, hydrogen-rich CSPNe (namely of A35 and NGC3587, the latter also known as M97 or the Owl Nebula) and to derive Teff and log g precisely from high-resolution, high-S/N (far-) ultraviolet observations obtained with FUSE and HST/STIS. For this purpose, we utilize NLTE model atmospheres calculated with TMAP, the Tübingen Model Atmosphere Package. Due to strong line absorption of the ISM, simultaneous modeling of interstellar features has become a standard tool in our analyses. We present preliminary results, demonstrating the importance of combining stellar and interstellar models, in order to clearly identify and measure the strengths of strategic photospheric lines.

  17. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Forcey, K S; Ross, D K [Birmingham Univ. (UK). Dept. of Physics; Iordanova, I A [Sofia Univ. (Bulgaria). Dept. of Solid State Physics

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.).

  18. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    International Nuclear Information System (INIS)

    Forcey, K.S.; Ross, D.K.; Iordanova, I.A.

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.)

  19. Detection of carbon dioxide in the gases evolved during the hot extraction determination of hydrogen in uranium ingots

    International Nuclear Information System (INIS)

    Jursik, M.L.; Pope, J.D.

    1977-08-01

    The hot extraction method was used at the National Lead Company of Ohio to determine hydrogen in uranium metal at the 2 ppM level. The volume of gas evolved from the heated sample was assumed to be hydrogen. When a liquid nitrogen trap was placed into the system the hydrogen values were reduced 5 to 10%. The gas retained by the nitrogen trap was identified by mass spectrometry as predominantly carbon dioxide. Low hydrogen values were observed only when the nitrogen trap was used in the analysis of high-carbon (300 to 600 ppM) uranium from NLO production ingots. However, hydrogen values for low-carbon (30 to 50 ppM) uranium were unaffected by the nitrogen trap. The formation of carbon dioxide appears to be associated with the carbon content of the uranium metal. Comparisons of hydrogen values obtained with the hot extraction method and with an inert fusion--thermal conductivity method are also presented. 3 tables, 4 figures

  20. Hot-wire substoichiometric tungsten oxide films deposited in hydrogen environment with n-type conductivity

    International Nuclear Information System (INIS)

    Kostis, I; Vasilopoulou, M; Giannakopoulos, K; Papadimitropoulos, G; Davazoglou, D; Michalas, L; Papaioannou, G; Konofaos, N; Iliadis, A A; Kennou, S

    2012-01-01

    Substoichiometric tungsten oxide nanostructured films were synthesized by a hot-wire deposition technique in hydrogen-rich environment and characterized for their structural and electrical properties. A semiconducting behaviour was identified, allowing n-type conductivity even at room temperature which is an important result since it is well known that fully stoichiometric tungsten trioxide is nearly an insulator. Current-voltage characteristics for various temperatures were measured for tungsten oxide/Si heterostructures and analysed using proper modelling. As a result, the conduction mechanism inside the films was identified and found to be of a dual nature, with variable range hopping being dominant at near room temperatures. The saturation current was found to be thermally activated and the activation energy was calculated at 0.40 eV and the grain boundaries barrier at 150 meV. From Hall measurements it was also revealed that the dominant carriers are electrons and a carrier concentration of about 10 14 cm -3 was estimated.

  1. Tissue chemical analysis with muonic X-rays

    International Nuclear Information System (INIS)

    Hutson, R.L.; Reidy, J.J.; Springer, K.; Daniel, H.; Knowles, H.B.

    1976-01-01

    The stopped muon channel at the Clinton P. Anderson Meson Physics Facility (LAMPF) was used as a source of muons for studying the elemental composition of tissue with muonic X rays. The X ray spectra from several types of tissue were used to determine the amounts of carbon, nitrogen, and oxygen present. These determinations agree with the results of more conventional chemical analysis. The results show that muonic X rays offer a non-invasive technique for determining the amounts of the more abundant elements present in selected regions of the body. (orig.) [de

  2. Nuclear fusion rate of the muonic T3 molecule

    International Nuclear Information System (INIS)

    Faghihi, F.; Eskandari, M. R.

    2004-01-01

    The ground state binding energy, size and effective nuclear charge of the muonic T 3 molecule are calculated using Born-Oppenheimer adiabatic approximation. The system possesses two minimum positions, one at typically muonic and the second at the atomic distances. A symmetric planar vibrational model between two minima is assumed and the approximated potential are calculated. Moreover, nuclear fusion rate calculations of the short-life molecule is carried out due to the overlap integral of the resonance nuclear compound nucleus and the molecular wave functions

  3. Production and Consumption of Hydrogen in Hot Spring Microbial Mats Dominated by a Filamentous Anoxygenic Photosynthetic Bacterium

    Science.gov (United States)

    Otaki, Hiroyo; Everroad, R. Craig; Matsuura, Katsumi; Haruta, Shin

    2012-01-01

    Microbial mats containing the filamentous anoxygenic photosynthetic bacterium Chloroflexus aggregans develop at Nakabusa hot spring in Japan. Under anaerobic conditions in these mats, interspecies interaction between sulfate-reducing bacteria as sulfide producers and C. aggregans as a sulfide consumer has been proposed to constitute a sulfur cycle; however, the electron donor utilized for microbial sulfide production at Nakabusa remains to be identified. In order to determine this electron donor and its source, ex situ experimental incubation of mats was explored. In the presence of molybdate, which inhibits biological sulfate reduction, hydrogen gas was released from mat samples, indicating that this hydrogen is normally consumed as an electron donor by sulfate-reducing bacteria. Hydrogen production decreased under illumination, indicating that C. aggregans also functions as a hydrogen consumer. Small amounts of hydrogen may have also been consumed for sulfur reduction. Clone library analysis of 16S rRNA genes amplified from the mats indicated the existence of several species of hydrogen-producing fermentative bacteria. Among them, the most dominant fermenter, Fervidobacterium sp., was successfully isolated. This isolate produced hydrogen through the fermentation of organic carbon. Dispersion of microbial cells in the mats resulted in hydrogen production without the addition of molybdate, suggesting that simultaneous production and consumption of hydrogen in the mats requires dense packing of cells. We propose a cyclic electron flow within the microbial mats, i.e., electron flow occurs through three elements: S (elemental sulfur, sulfide, sulfate), C (carbon dioxide, organic carbon) and H (di-hydrogen, protons). PMID:22446313

  4. Increase of hot initial plasma energy content in the end system of AMBAL-M during hydrogen puffing

    International Nuclear Information System (INIS)

    Akhmetov, Timour; Bekher, Sergei; Davydenko, Vladimir; Krivenko, Aleksander; Muraviev, Maksim; Reva, Vladimir; Sokolov, Vladimir

    2001-01-01

    At the end system of the completely axisymmetric mirror trap AMBAL-M the experiments on creation and study of a hot initial plasma have been performed. In the experiments a gas-box was used for hydrogen supply into the hot startup plasma in the mirror trap to increase the plasma density. The hot initial plasma in the trap was produced by the trapping of a plasma stream with developed electrostatic turbulence generated by a gas-discharge source located outside the entrance throat. It was found that in addition to the increase in the plasma density by a factor of 2-3, hydrogen puffing resulted in an unexpected nearly twofold diamagnetism increase. The gas puffing did not reduce the electron temperature in the trap. Essential for explanation of the observed effect is the fact that with the gas puffing the measured plasma potential in the trap increased. The increase in the plasma potential enhanced the trapping of the ion flow entering the trap and increased the average energy of the electron flow entering the trap. It was found that with the increasing hydrogen puffing rate plasma parameters in the trap were saturated. (author)

  5. Radiative nonrecoil nuclear finite size corrections of order $\\alpha(Z \\alpha)^5$ to the Lamb shift in light muonic atoms

    OpenAIRE

    Faustov, R. N.; Martynenko, A. P.; Martynenko, F. A.; Sorokin, V. V.

    2017-01-01

    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα)5 to the Lamb shift in muonic hydrogen and helium. To construct the interaction potential of particles, which gives the necessary contributions to the energy spectrum, we use the method of projection operators to states with a definite spin. Separate analytic expressions for the contributions of the muon self-energy, the muon vertex operator and the amplitude...

  6. New muonic-atom test of vacuum polarization

    International Nuclear Information System (INIS)

    Dixit, M.S.; Carter, A.L.; Hincks, E.P.; Kessler, D.; Wadden, J.S.; Hargrove, C.K.; McKee, R.J.; Mes, H.; Anderson, H.L.

    1975-01-01

    In order to check the discrepancy between calculation and experiment in muonic atoms, we have remeasured the 5g-4f transitions in Pb and the 5g-4f and the 4f-3d transitions in Ba. Our new results show no discrepancy and confirm recent theoretical calculations of vacuum polarization to within 0.5%

  7. Test of quantum-electrodynamical corrections in muonic atoms

    CERN Document Server

    Walter, H K; Böhm, F; Engfer, R; Link, R; Michaelsen, R; Petitjean, C; Schellenberg, L; Schneuwly, H; Schröder, W U; Von Gunten, A H; Vuilleumier, J H; Zehnder, A

    1972-01-01

    Energies of the 5f-4f muonic X-rays have been measured in /sup nat/Hg and /sup 203/Tl with an accuracy of about 25 eV. They are found to be smaller than theoretical energies including recently revised calculations of higher-order vacuum polarization, by about two standard deviations. (10 refs).

  8. Isomer shifts of the octupole doublet in muonic 207Pb

    International Nuclear Information System (INIS)

    Budick, B.; Anigstein, R.; Kast, J.W.

    1980-01-01

    Isomer shifts in the doublet 5/2 + , 7/2 + levels in muonic 207 Pb have been measured. The shifts are essentially the same as in the core 3 - collective state. They support the hypothesis that the octupole vibration does not conserve volume. (orig.)

  9. Charge distributions of barium isotopes from muonic X-rays

    International Nuclear Information System (INIS)

    Shera, E.B.; Wohlfahrt, H.D.; Hoehn, M.V.; Tanaka, Y.

    1982-01-01

    The results of a muonic X-ray study of the charge radii of stable barium isotopes are presented and compared with optical isotope shifts. The isotope shifts Δ 2 > of a wide range of barium isotopes are found to be in good agreement with the droplet model and with IBA calculations. (orig.)

  10. Radiative nonrecoil nuclear finite size corrections of order α(Zα)5 to the Lamb shift in light muonic atoms

    Science.gov (United States)

    Faustov, R. N.; Martynenko, A. P.; Martynenko, F. A.; Sorokin, V. V.

    2017-12-01

    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα) 5 to the Lamb shift in muonic hydrogen and helium. To construct the interaction potential of particles, which gives the necessary contributions to the energy spectrum, we use the method of projection operators to states with a definite spin. Separate analytic expressions for the contributions of the muon self-energy, the muon vertex operator and the amplitude with spanning photon are obtained. We present also numerical results for these contributions using modern experimental data on the electromagnetic form factors of light nuclei.

  11. Signatures of Hot Molecular Hydrogen Absorption from Protoplanetary Disks. I. Non-thermal Populations

    Energy Technology Data Exchange (ETDEWEB)

    Hoadley, Keri; France, Kevin; Arulanantham, Nicole; Loyd, R. O. Parke; Kruczek, Nicholas, E-mail: keri.hoadley@colorado.edu [Laboratory for Atmospheric and Space Physics (LASP), University of Colorado Space Science Building (SPSC), 3665 Discovery Drive, Boulder, CO 80303 (United States)

    2017-09-01

    The environment around protoplanetary disks (PPDs) regulates processes that drive the chemical and structural evolution of circumstellar material. We perform a detailed empirical survey of warm molecular hydrogen (H{sub 2}) absorption observed against H i-Ly α (Ly α : λ 1215.67) emission profiles for 22 PPDs, using archival Hubble Space Telescope ultraviolet (UV) spectra to identify H{sub 2} absorption signatures and quantify the column densities of H{sub 2} ground states in each sightline. We compare thermal equilibrium models of H{sub 2} to the observed H{sub 2} rovibrational level distributions. We find that, for the majority of targets, there is a clear deviation in high-energy states ( T {sub exc} ≳ 20,000 K) away from thermal equilibrium populations ( T (H{sub 2}) ≳ 3500 K). We create a metric to estimate the total column density of non-thermal H{sub 2} ( N (H{sub 2}){sub nLTE}) and find that the total column densities of thermal ( N (H{sub 2})) and N (H{sub 2}){sub nLTE} correlate for transition disks and targets with detectable C iv-pumped H{sub 2} fluorescence. We compare N (H{sub 2}) and N (H{sub 2}){sub nLTE} to circumstellar observables and find that N (H{sub 2}){sub nLTE} correlates with X-ray and far-UV luminosities, but no correlations are observed with the luminosities of discrete emission features (e.g., Ly α , C iv). Additionally, N (H{sub 2}) and N (H{sub 2}){sub nLTE} are too low to account for the H{sub 2} fluorescence observed in PPDs, so we speculate that this H{sub 2} may instead be associated with a diffuse, hot, atomic halo surrounding the planet-forming disk. We create a simple photon-pumping model for each target to test this hypothesis and find that Ly α efficiently pumps H{sub 2} levels with T {sub exc} ≥ 10,000 K out of thermal equilibrium.

  12. Radiative nonrecoil nuclear finite size corrections of order α(Zα5 to the Lamb shift in light muonic atoms

    Directory of Open Access Journals (Sweden)

    R.N. Faustov

    2017-12-01

    Full Text Available On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα5 to the Lamb shift in muonic hydrogen and helium. To construct the interaction potential of particles, which gives the necessary contributions to the energy spectrum, we use the method of projection operators to states with a definite spin. Separate analytic expressions for the contributions of the muon self-energy, the muon vertex operator and the amplitude with spanning photon are obtained. We present also numerical results for these contributions using modern experimental data on the electromagnetic form factors of light nuclei. Keywords: Lamb shift, Muonic atoms, Quantum electrodynamics

  13. Effect of addition of water-soluble salts on the hydrogen generation of aluminum in reaction with hot water

    International Nuclear Information System (INIS)

    Razavi-Tousi, S.S.; Szpunar, J.A.

    2016-01-01

    Aluminum powder was ball milled for different durations of time with different weight percentages of water-soluble salts (NaCl and KCl). The hydrogen generation of each mixture in reaction with hot water was measured. A scanning electron microscope (SEM) as well as energy-dispersive spectroscopy (EDS) were used to investigate the morphology, surfaces and cross sections of the produced particles. The results show that the presence of salts in the microstructure of the aluminum considerably increases the hydrogen generation rate. At shorter milling times, the salt covers the aluminum particles and becomes embedded in layers within the aluminum matrix. At higher milling durations, salt and aluminum phases form composite particles. A higher percentage of the second phase significantly decreases the milling time needed for activation of the aluminum particles. Based on the EDS results from cross sections of the milled particles, a mechanism for improvement of the hydrogen generation rate in the presence of salts is suggested. - Highlights: • Milling and water soluble salts have a synergic effect on hydrogen generation. • Salt and aluminum form composite particles by milling. • Salt is dissolved in water leaving aluminum with much fresh surfaces for the reaction. • The chemical effect of salt on the reaction is negligible compared to its structural effect.

  14. Hyperfine structure of S-states of muonic deuterium

    Directory of Open Access Journals (Sweden)

    Alexey P. Martynenko

    2015-09-01

    Full Text Available On the basis of quasipotential method in quantum electrodynamics we calculate corrections of order $\\alpha^5$ and $\\alpha^6$ to hyperfine structure of $S$-wave energy levels of muonic deuterium. Relativistic corrections, effects of vacuum polarization in first, second and third orders of perturbation theory, nuclear structure and recoil corrections are taken into account. The obtained numerical values of hyperfine splitting $\\Delta E^{hfs}(1S=50.2814$ meV ($1S$ state and $\\Delta E^{hfs}(2S=6.2804$ meV ($2S$ state represent reliable estimate for a comparison with forthcoming experimental data of CREMA collaboration. The hyperfine structure interval $\\Delta_{12}=8\\Delta E^{hfs}(2S- \\Delta E^{hfs}(1S=-0.0379$ meV can be used for precision check of quantum electrodynamics prediction for muonic deuterium.

  15. Effect of Nb on hydrogen-induced delayed fracture in high strength hot stamping steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shiqi [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); College of Mechanical Engineering, Yangtze University, Jingzhou 434023 (China); Huang, Yunhua, E-mail: huangyh@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Sun, Bintang, E-mail: bingtangsun@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Liao, Qingliang [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Hongzhou [CITIC Metal Co. Ltd., Room 1901, Capital Mansion 6, Xin Yuan Nanlu, Chaoyang District, Beijing 100004 (China); The School of Resources and Environmental Engineering, East China University of Science and Technology, Meilong road 130, Xujiahui District, Shanghai 200237 (China); Jian, Bian [Niobium Tech Asia, 068898 Singapore (Singapore); Mohrbacher, Hardy [NiobelCon bvba, 2970 Schilde (Belgium); Zhang, Wei; Guo, Aimin [CITIC Metal Co. Ltd., Room 1901, Capital Mansion 6, Xin Yuan Nanlu, Chaoyang District, Beijing 100004 (China); Zhang, Yue [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); The State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-02-25

    The effect of Nb addition (0.022, 0.053, 0.078 wt%) on the hydrogen-induced delayed fracture resistance of 22MnB5 was studied by constant load test and electrochemical hydrogen permeation method. It is shown that the appropriate addition of Nb is beneficial to the improvement of the delayed fracture resistance of tested steel, especially when the steel contains high concentration of hydrogen, and the maximum delayed fracture resistance is obtained at a Nb content of 0.053%.The result of hydrogen permeation test shows that the diffusion coefficient of hydrogen in the steel containing niobium is lower than that in steel without niobium, which indicates that it is harder for hydrogen in the steels containing niobium to diffuse and aggregate. In addition, the reason for Nb improving the delayed fracture resistance of steels is discussed from two aspects: hydrogen trap effect and grain refinement effect. The analysis shows that the main reason leading to the improvement of the delayed fracture resistance is the hydrogen trapping effect of NbC while the grain refinement effect of Nb(C,N) secondary.

  16. Effect of Nb on hydrogen-induced delayed fracture in high strength hot stamping steels

    International Nuclear Information System (INIS)

    Zhang, Shiqi; Huang, Yunhua; Sun, Bintang; Liao, Qingliang; Lu, Hongzhou; Jian, Bian; Mohrbacher, Hardy; Zhang, Wei; Guo, Aimin; Zhang, Yue

    2015-01-01

    The effect of Nb addition (0.022, 0.053, 0.078 wt%) on the hydrogen-induced delayed fracture resistance of 22MnB5 was studied by constant load test and electrochemical hydrogen permeation method. It is shown that the appropriate addition of Nb is beneficial to the improvement of the delayed fracture resistance of tested steel, especially when the steel contains high concentration of hydrogen, and the maximum delayed fracture resistance is obtained at a Nb content of 0.053%.The result of hydrogen permeation test shows that the diffusion coefficient of hydrogen in the steel containing niobium is lower than that in steel without niobium, which indicates that it is harder for hydrogen in the steels containing niobium to diffuse and aggregate. In addition, the reason for Nb improving the delayed fracture resistance of steels is discussed from two aspects: hydrogen trap effect and grain refinement effect. The analysis shows that the main reason leading to the improvement of the delayed fracture resistance is the hydrogen trapping effect of NbC while the grain refinement effect of Nb(C,N) secondary

  17. Delayed fission of the 238U muonic atom

    International Nuclear Information System (INIS)

    Ganzorig, Dz.; Krogulski, T.; Kuznetsov, V.D.; Polikanov, S.M.; Sabirov, B.M.

    1975-01-01

    The time distributions of fission and muon free decay events with respect to the moment of the muon-stop event have been measured for double and triple coincidences between these three events. The triple-coincidence time distributions give an indication of the o-curence of two new effects: the delayed fission of muonic 238 U atom and conversion of muons from the fission fragments

  18. Simultaneous and multielemental analysis by muonic x-rays for inside Japanese bronze and gold coins

    International Nuclear Information System (INIS)

    Ninomiya, K.; Yoshida, G.; Inagaki, M.; Shinohara, A.; Kubo, M.K.; Suzuki, T.; Nagatomo, T.; Kawamura, N.; Strasser, P.; Shimomura, K.; Miyake, Y.; Kobayashi, Y.; Higemoto, Wataru; Sakamoto, Shinichi; Saito, T.

    2013-01-01

    A nondestructive, quantitative and multielemental analysis method for bulk samples was develop, which was based on the measurement of high-energy muonic X-rays emitted from muonic atoms inside material after muon irradiation. We demonstrated quantitative determination of the elemental composition inside archaeological artifacts without sample destruction. (author)

  19. Some recent results on μ-transfer in systems with bound hydrogen

    International Nuclear Information System (INIS)

    Knight, J.D.; Mausner, L.F.; Orth, C.J.; Schillaci, M.E.; Naumann, R.A.; Schmidt, G.

    1977-01-01

    Preliminary results are given for two sets of experiments conducted in order to obtain information on the role of bound hydrogen in possible μ transfer processes by comparisons of muonic Lyman spectra. Muonic x-ray intensity patterns of Cl in CCl 4 , CH 2 Cl 2 and a CCl 4 + C 8 H 18 mixture. Secondly the same type of experiment was performed but with F as the test element. Muonic x-ray spectra of the normal and deutero forms of a compound were compared

  20. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell for a pre-humidified hydrogen stream

    DEFF Research Database (Denmark)

    Berning, Torsten; Shakhshir, Saher Al

    2016-01-01

    In a recent publication it has been shown how the water balance in a proton exchange membrane fuel cell can be determined employing hot wire anemometry. The hot wire sensor has to be placed into the anode outlet pipe of the operating fuel cell, and the voltage signal E that is read from the senso....... Finally, it will be shown how previously developed dew point diagrams for the anode side in a fuel cell can be corrected for a humidified hydrogen inlet stream....

  1. Correlation between hydrogen release and degradation of limestone concrete exposed to hot liquid sodium in inert atmosphere

    International Nuclear Information System (INIS)

    Parida, F.C.; Das, S.K.; Sharma, A.K.; Ramesh, S.S.; Somayajulu, P.A.; Kannan, S.E.

    2005-01-01

    Full text of publication follows: Concrete is used as a structural material in a Fast Breeder Reactor (FBR) plant for the construction of its foundation, containment, radiation shield and equipment support structures. An accidental leakage of hot sodium on these civil structures can bring about thermo-chemical reactions, with concrete producing hydrogen gas and causing structural degradation. The concrete damage and hydrogen generation take place concurrently due to conduction of heat from sodium into the concrete and migration of steam / moisture in counter current direction towards sodium. In a series of experiments conducted with limestone concrete for two different types of design corresponding to composition and geometry, were exposed to liquid sodium (∼2 kg) at initial temperatures varying from 180 deg. C to 500 deg. C in an inerted test vessel (Capacity = 203 L). Immersion heater was employed to heat the sodium pool on the concrete cavity during the test period in some test runs. On-line continuous measurement of pressure, temperature, hydrogen gas and oxygen gas was carried out. Pre- and post- test nondestructive testing such as colour photography, spatial profiling of ultrasonic pulse velocity and measurement of dimensions were also conducted. Solid samples were collected from sodium debris by manual core drilling machine and from concrete block by hand held electric drilling machine. These samples were subjected to chemical analysis for the determination of free and bound water along with unburnt and burnt sodium. The hydrogen generation parameters such as average and peak release rate as well as release efficiency are derived from measured test variables. These test variables include temperature, pressure and hydrogen concentration in the argon atmosphere contained in the test vessel. The concrete degradation parameters encompass percentage reduction in ultrasonic pulse velocity, depth of physical and chemical dehydration and sodium penetration. These

  2. Elemental analysis of bronze artifacts by muonic X-ray spectroscopy

    International Nuclear Information System (INIS)

    Ninomiya, Kazuhiko; Shinohara, Atsushi; Kubo, Michael K.; Strasser, Patrick; Nagatomo, Takashi; Kawamura, Naritoshi; Shimomura, Koichiro; Miyake, Yasuhiro; Kobayashi, Yoshio; Ishida, Katsuhiko; Higemoto, Wataru; Suzuki, Takao; Saito, Tsutomu

    2015-01-01

    A quantitative and multi-elemental analysis method for bulk samples based on muonic X-ray spectroscopy was applied to bronze artifacts (Tempo-Tsuho coins and a Seiun-kyo mirror). This method is based on the measurement of the characteristic high-energy muonic X-rays emitted in a sample after muon irradiation. The elemental compositions of these bronze artifacts were determined from muonic X-ray intensities in a non-destructive manner, using the relation between the muonic X-ray intensity and the elemental composition of the Cu–Sn–Pb alloy system. The analyzed values agreed well with those determined by X-ray fluorescence spectroscopy. We also estimated the detection limit of this method in the present experimental setup as 0.81 wt% of the background signal of the muonic X-ray spectra. (author)

  3. Experimental investigation on the thermal properties of hydrogen jet flame and hot currents in the downstream region

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Tomohiko; Mogi, Toshio; Wada, Yuji; Horiguchi, Sadashige [Research Core for Explosion Safety, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Hamada, Shota; Miyake, Atsumi; Ogawa, Terushige [Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2008-07-15

    A series of experiments were conducted to understand the thermal hazards of hydrogen jet flames. In particular, we focused on the temperature properties of hot currents in the downstream region, because it was expected that this involved the most serious thermal hazards. The flame length and width depended on the nozzle diameter and the spouting pressure, namely, the mass flow rate, with similar dependences that were reported by other researchers. The temperature rise from ambient air along the trajectory depended on the balance of the flame length and the traveling distance from the flame tip. The position of the trajectory depended not only on the balance of flame length and the traveling distance, but also on the horizontal momentum induced by the spouting pressure. Empirical formulae for predicting the position and temperature rise of the trajectory were developed by the flame length, traveling distance, spouting pressure, and nozzle diameter as variables. (author)

  4. A supramolecular structure insight for conversion property of cellulose in hot compressed water: Polymorphs and hydrogen bonds changes.

    Science.gov (United States)

    Wang, Yan; Lian, Jie; Wan, Jinquan; Ma, Yongwen; Zhang, Yingshi

    2015-11-20

    Waste paper samples with different cellulose supramolecular structure were treated in hot compressed water (HCW) at 375°C and 22.5MPa within 200s to evaluate the specific effect mechanism of cellulose supramolecular structure on the conversion of waste paper to reusable resource. Although the distribution of liquid products and the oligosaccharides were related to reaction time, depolymerization and decrystallization of the cellulose, the characteristics absorption peak of cellulose from FTIR analysis and crystal structure of the cellulose detected in the residues with hydrolysis rate up 96.5% indicated crystal structure was the dominant factor that affect conversion behavior of waste paper. The conversion of cellulose Iβ to cellulose Iα or cellulose I(α+β) in HCW demonstrated that the recrystallization occurred during the decrystallization of cellulose through the rearrangement of hydrogen bonds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Directly calculated electrical conductivity of hot dense hydrogen from molecular dynamics simulation beyond Kubo-Greenwood formula

    Science.gov (United States)

    Ma, Qian; Kang, Dongdong; Zhao, Zengxiu; Dai, Jiayu

    2018-01-01

    Electrical conductivity of hot dense hydrogen is directly calculated by molecular dynamics simulation with a reduced electron force field method, in which the electrons are represented as Gaussian wave packets with fixed sizes. Here, the temperature is higher than electron Fermi temperature ( T > 300 eV , ρ = 40 g / cc ). The present method can avoid the Coulomb catastrophe and give the limit of electrical conductivity based on the Coulomb interaction. We investigate the effect of ion-electron coupled movements, which is lost in the static method such as density functional theory based Kubo-Greenwood framework. It is found that the ionic dynamics, which contributes to the dynamical electrical microfield and electron-ion collisions, will reduce the conductivity significantly compared with the fixed ion configuration calculations.

  6. Nonrelativistic hyperfine splitting in muonic helium by adiabatic perturbation theory

    International Nuclear Information System (INIS)

    Drachman, R.J.

    1980-01-01

    Huang and Hughes have recently discussed the hyperfine splitting Δν of muonic helium (α ++ μ - e - ) using a variational approach. In this paper, the Born-Oppenheimer approximation is used to simplify the evaluation of Δν in the nonrelativistic limit. The first-order perturbed wave function of the electron is obtained in closed form by slightly modifying the method used by Dalgarno and Lynn. The result Δν=4450 MHz, is quite close to the published result of Huang and Hughes 4455.2 +- 1 MHz, which required a very large Hylleraas expansion as well as considerable extrapolation

  7. Muonic X-ray intensities in phosphorus- and selenium modifications

    International Nuclear Information System (INIS)

    Kaeser, K.; Robert-Tissot, B.; Schaller, L.A.; Schellenberg, L.; Schneuwly, H.

    1979-01-01

    Muonic X-ray intensity measurements have been performed at SIN on allotropic modifications of phosphorus (white, red and black) and of selenium (red and black). Structure effects have been found in the intensity ratios of the K-series between amorphous and crystalline modifications of the same element. The effect in the higher series (Se) is less pronounced. On the other hand, the two crystalline phosphorus modifications (red and black) show the same intensity behavior. The root-mean-square radii 2 >sup(1/2) of phosphorus and (natural) selenium were found to be 3.187(3) fm and 4.138(1) fm respectively. (Auth.)

  8. Precision test of vacuum polarization in heavy muonic atoms

    International Nuclear Information System (INIS)

    Dubler, T.; Kaeser, K.; Robert-Tissot, B.; Schaller, L.A.; Schellenberg, L.; Schneuwly, H.

    1978-01-01

    In order to test the QED corrections, and in particular the vacuum polarization, muonic 4f-3d transitions in Ba and Ce and 5g-4f transitions in Tl and Pb have been measured using Ge(Li) detectors. An absolute energy accuracy of +- 8 eV corresponding to a relative error of 17-19 ppm has been obtained. The experimental energies agree with theory within the total uncertainty of +- 10 eV. This corresponds to a test of the QED vacuum polarization calculations of between 0.35% and 0.50%. (Auth.)

  9. Hyperfine structure of S-states of muonic tritium

    Directory of Open Access Journals (Sweden)

    Martynenko F.A.

    2017-01-01

    Full Text Available On the basis of quasipotential method in quantum electrodynamics we carry out a precise calculation of hyperfine splitting of S-states in muonic tritium. The one-loop and two-loop vacuum polarization corrections, relativistic effects, nuclear structure corrections in first and second orders of perturbation theory are taken into account. The contributions to hyperfine structure are obtained in integral form and calculated analytically and numerically. Obtained results for hyperfine splitting can be used for a comparison with future experimental data of CREMA collaboration.

  10. Lamb shift in muonic ions of lithium, beryllium and boron

    OpenAIRE

    Krutov, A. A.; Martynenko, A. P.; Martynenko, F. A.; Sukhorukova, O. S.

    2016-01-01

    We present a precise calculation of the Lamb shift $(2P_{1/2}-2S_{1/2})$ in muonic ions $(\\mu ^6_3Li)^{2+},~(\\mu ^7_3Li)^{2+}$, $(\\mu ^9_4Be)^{3+},~(\\mu ^{10}_4Be)^{3+}$, $(\\mu ^{10}_5B)^{4+},~(\\mu ^{11}_5B)^{4+}$. The contributions of orders $\\alpha^3\\div\\alpha^6$ to the vacuum polarization, nuclear structure and recoil, relativistic effects are taken into account. Our numerical results are consistent with previous calculations and improve them due to account of new corrections. The obtained...

  11. Charge exchange of hydrogen atoms with multiply charged ions in a hot plasma

    International Nuclear Information System (INIS)

    Abramov, V.A.; Baryshnikov, F.F.; Lisitsa, V.S.

    1980-08-01

    The symmetry properties of the hydrogen atom are used to calculate the charge exchange cross-sections sigma of hydrogen with the nuclei of multiply charged ions, allowance being made for the degeneration of final states. If the transitions between these states produced by rotation of the internuclear axis are taken into account, there is a qualitative change in the dependence of sigma on v for low values of v (a gradual decrease in the cross-section instead of the exponential one in the Landau-Zener model) and also a considerable increase in the peak cross-section. The cross-sections are calculated for a wide range of velocities and charge values Z. It is shown that the cross-section may be approximated to within approximately 9 /v).10 -15 cm 2 for Z>=18 (v in cm/s). A detailed comparison with the calculations of various authors is performed. The distribution of final states over orbital angular momenta is found. A calculation is made of variation in the spectral line intensities of the ion O +7 with injection of a neutral hydrogen beam in conditions similar to the experimental conditions on the ORMAK facility. (author)

  12. Influence of silicon on hot-dip aluminizing process and subsequent oxidation for preparing hydrogen/tritium permeation barrier

    Energy Technology Data Exchange (ETDEWEB)

    Han, Shilei; Li, Hualing; Wang, Shumao; Jiang, Lijun; Liu, Xiaopeng [Energy Materials and Technology Research Institute, General Research Institute for Nonferrous Metals, Beijing 100088 (China)

    2010-04-15

    The development of the International Thermonuclear Experimental Reactor (ITER) requires the production of a material capable of acting as a hydrogen/tritium permeation barrier on low activation steel. It is well known that thin alumina layer can reduce the hydrogen permeation rate by several orders of magnitude. A technology is introduced here to form a ductile Fe/Al intermetallic layer on the steel with an alumina over-layer. This technology, consisting of two main steps, hot-dip aluminizing (HDA) and subsequent oxidation behavior, seems to be a promising coating method to fulfill the required goals. According to the experiments that have been done in pure Al, the coatings were inhomogeneous and too thick. Additionally, a large number of cracks and porous band could be observed. In order to solve these problems, the element silicon was added to the aluminum melt with a nominal composition. The influence of silicon on the aluminizing and following oxidation process was investigated. With the addition of silicon into the aluminum melt, the coating became thinner and more homogeneous. The effort of the silicon on the oxidation behavior was observed as well concerning the suppression of porous band and cracks. (author)

  13. Isotope exchange reactions in hydrogen mixtures

    International Nuclear Information System (INIS)

    Czaplinski, W.; Gula, A.; Kravtsov, A.; Mikhailov, A.; Popov, N.

    1990-12-01

    The rates of isotopic exchange for the excited states of muonic hydrogen are calculated as functions of collision energy. Ground state population q 1s for different collision energies, target densities and isotope concentrations is obtained. It is shown that for principal quantum numbers n > 5 the isotopic exchange still considerably influences the value of q 1s . (author)

  14. Nuclear Fusion Rate Study of a Muonic Molecule via Nuclear Threshold Resonances

    Science.gov (United States)

    Faghihi, F.; Eskandari, M. R.

    This work follows our previous calculations of the ground state binding energy, size, and the effective nuclear charge of the muonic T3 molecule, using the Born-Oppenheimer adiabatic approximation. In our past articles, we showed that the system possesses two minimum positions, the first one at the muonic distance and the second at the atomic distance. Also, the symmetric planner vibrational model assumed between the two minima and the approximated potential were calculated. Following from the previous studies, we now calculate the fusion rate of the T3 muonic molecule according to the overlap integral of the resonance nuclear compound nucleus and the molecular wave functions.

  15. The Minimum Binding Energy and Size of Doubly Muonic D3 Molecule

    Science.gov (United States)

    Eskandari, M. R.; Faghihi, F.; Mahdavi, M.

    The minimum energy and size of doubly muonic D3 molecule, which two of the electrons are replaced by the much heavier muons, are calculated by the well-known variational method. The calculations show that the system possesses two minimum positions, one at typically muonic distance and the second at the atomic distance. It is shown that at the muonic distance, the effective charge, zeff is 2.9. We assumed a symmetric planar vibrational model between two minima and an oscillation potential energy is approximated in this region.

  16. Higher order corrections to energy levels of muonic atoms

    International Nuclear Information System (INIS)

    Rinker, G.A. Jr.; Steffen, R.M.

    1975-08-01

    In order to facilitate the analysis of muonic x-ray spectra, the results of numerical computations of all higher order quantum electrodynamical corrections to the energy levels of muonic atoms are presented in tabular and graphical form. These corrections include the vacuum polarization corrections caused by emission and reabsorption of virtual electron pairs to all orders, including ''double-bubble'' and ''cracked-egg'' diagrams. An estimate of the Delbruecke scattering-type correction is presented. The Lamb-shift (second- and fourth-order vertex) corrections have been calculated including the correction for the anomalous magnetic moment of the muon. The relativistic nuclear motion (or recoil) correction as well as the correction caused by the screening of the atomic electrons is presented in graphs. For the sake of completeness a graph of the nuclear polarization as computed on the basis of Chen's approach has been included. All calculations were made with a two-parameter Fermi distribution of the nuclear charge density. 7 figures, 23 references

  17. Polarization transfer from polarized nuclear spin to μ- spin in muonic atom

    International Nuclear Information System (INIS)

    Kuno, Yoshitaka; Nagamine, Kanetada; Yamazaki, Toshimitsu.

    1987-02-01

    A theoretical study of polarization transfer from an initially-polarized nuclear spin to a μ - spin in a muonic atom is given. The switching of the hyperfine interaction at excited muonic states as well as at the ground 1s state is taken into account. The upper state of hyperfine doublet at the muonic 1s state is considered to proceed down to the lower state. It is found that as the hyperfine interaction becomes effective at higher excited muonic orbitals, a less extent of polarization is transferred from the nuclear spin to the μ - spin. The theoretical values obtained are compared with the recent experiment of μ - repolarization in a polarized 209 Bi target. (author)

  18. Generalized Bethe-Negele inequalities for excited states in muonic atoms

    International Nuclear Information System (INIS)

    Klarsfeld, S.

    1976-11-01

    Rigorous upper and lower bounds are derived for the Bethe logarithms in excited states of muonic atoms. Comparison with previous empirical estimates shows that the latter are inadequate in certain cases

  19. Correlated wave functions for three-particle systems with Coulomb interaction - The muonic helium atom

    Science.gov (United States)

    Huang, K.-N.

    1977-01-01

    A computational procedure for calculating correlated wave functions is proposed for three-particle systems interacting through Coulomb forces. Calculations are carried out for the muonic helium atom. Variational wave functions which explicitly contain interparticle coordinates are presented for the ground and excited states. General Hylleraas-type trial functions are used as the basis for the correlated wave functions. Excited-state energies of the muonic helium atom computed from 1- and 35-term wave functions are listed for four states.

  20. Spectral analysis of four surprisingly similar hot hydrogen-rich subdwarf O stars

    Science.gov (United States)

    Latour, M.; Chayer, P.; Green, E. M.; Irrgang, A.; Fontaine, G.

    2018-01-01

    suggests that the system is a physical binary. However, the lack of radial velocity variations points towards a low inclination and/or long orbital period. Spectroscopic and Hipparcos distances are in good agreement for our three brightest stars. Conclusions: We performed a spectroscopic analysis of four hot sdO stars that are very similar in terms of atmospheric parameters and chemical compositions. The rotation velocities of our stars are significantly higher than what is observed in their immediate progenitors on the EHB, suggesting that angular momentum may be conserved as the stars evolve away from the EHB.

  1. P-d capture reactions in muonic molecules

    International Nuclear Information System (INIS)

    Friar, J.L.

    1991-01-01

    Capture reactions for very low-energy n-d and p-d systems are calculated and compared with experiment, as are low-energy n-d and p-d scattering. We find excellent agreement for the n-d scattering lengths, but poor agreement for the p-d case, which we believe is a problem with the experimental extrapolation. The n-d radiative capture is sensitive to details of the meson-exchange currents, but reasonable models agree with the data. The latter models are in good agreement with experiment when extended to the p-d case. Our large quartet capture rate resolves a long-standing anomaly. The EO capture matrix element recently obtained from a reanalysis of internal conversion in muonic molecules is in excellent agreement with our predictions. This matrix element is very clean theoretically and provides the best test of the calculations. 33 refs., 3 figs., 1 tab

  2. Test of quantum electrodynamics by muonic atoms: An experimental contribution

    International Nuclear Information System (INIS)

    Tauscher, L.; Backenstoss, G.; Fransson, K.; Koch, H.; Nilsson, A.; De Raedt, J.

    1975-01-01

    The large unexplained deviations of the experimental muonic 4-3 transitions in Ba and 5-4 transitions in Pb from calculations were found not to be existent. The absolute energies of these transitions agree, on the average, with theory to within 10 eV: The differences between experimental and calculated energies E)-E) are +2plus-or-minus13 and -2plus-or-minus12 eV for the μ - -Ba 4f 5 / 2 -3d 3 / 2 and 4f 7 / 2 -3d 5 / 2 transitions, respectively, and 10plus-or-minus16 and -13plus-or-minus14 eV for the μ - -Pb 5g 7 / 2 -4f 5 / 2 and 5g 9 / 2 -4f 7 / 2 transitions, respectively

  3. Vacuum polarization effects in low-energy muonic atom collisions

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1995-01-01

    We estimate the vacuum polarization (VP) correction to the Coulomb interaction in collisions of muonic atoms. It is shown that the VP effect, amplified by the low-lying virtual state var-epsilon var-theta ∼10 eV, is of the order of ∼1--2 % in the S-wave cross sections for pμ+p collisions as var-epsilon ≤ var-epsilon var-theta . The VP amplitude becomes comparable to the anomalously small pure Coulomb amplitude for the singlet tμ+t scattering as var-epsilon →0 and near the Ramsauer-Townsend minima in the dμ+p and tμ+p scattering

  4. Quadrupole interactions in pionic and muonic tantalum and rhenium

    International Nuclear Information System (INIS)

    Konijn, J.; Doesburg, W. van; Ewan, G.T; Johansson, T.; Tibell, G.

    1981-01-01

    The hyperfine splitting of pionic and muonic X-rays in natural Re has been studied using the known ratio (accurate to 1.6 parts in 10 5 ) of the quadrupole moments of the two naturally occurring 185 Re and 187 Re isotopes. From the hyperfine splitting of the 5g → 4f and 4f → 3d pionic X-rays the effective quadrupole hyperfine constants were determined to be 187 A 2 sup(e)sup(f)sup(f) (4f) = 1.163 +- 0.010 keV and 187 A 2 sup(e)sup(f)sup(f) (3d) = 5.39 +- 0.63 keV, giving strong interaction quadrupole shifts epsilon 2 (4f) = 46 +- 10 eV and epsilon 2 (3d) = 1.3 +- 0.6 keV. The strong interaction monopole shifts epsilon 0 and widths GAMMA 0 of the 5g, 4f and 3d levels have also been measured. For the two higher orbits, standard optical-potential calculations fit the measured shifts and widths quite well. The observed deeper-lying 3d state, however, has shifts and widths that differ by a factor of 2 or more from the predictions. From the measured quadrupole hyperfine constants of the 4f level we calculate the spectroscopic quadrupole moments to be 187 Qsup(μ) = 2.09 +- 0.04 b, 187 Qsup(π) = 2.07 +- 0.02 b, 185 Qsup(μ) = 2.21 +- 0.04 b, and 185 Qsup(π) = 2.18 +- 0.02 b. In addition, muonic X-rays from 181 Ta were observed; using the same methods for determining the quadrupole moments as above, a value of 181 Qsup(μ) = 3.28 +- 0.06 b was obtained, in good agreement with earlier published data. (orig.)

  5. Study of porogen removal by atomic hydrogen generated by hot wire chemical vapor deposition for the fabrication of advanced low-k thin films

    Energy Technology Data Exchange (ETDEWEB)

    Godavarthi, S., E-mail: srinivas@cinvestav.mx [Program of Nanoscience and Nanotechnology, Cinvestav-IPN (Mexico); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Fisicas, Av. Universidad, Cuernavaca, Morelos (Mexico); Wang, C.; Verdonck, P. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Matsumoto, Y.; Koudriavtsev, I. [Program of Nanoscience and Nanotechnology, Cinvestav-IPN (Mexico); SEES, Electrical Engineering Department, Cinvestav-IPN (Mexico); Dutt, A. [SEES, Electrical Engineering Department, Cinvestav-IPN (Mexico); Tielens, H.; Baklanov, M.R. [imec, Kapeldreef 75, 3001 Leuven (Belgium)

    2015-01-30

    In order to obtain low-k dielectric films, a subtractive technique, which removes sacrificial porogens from a hydrogenated silicon oxycarbide (SiOC:H) film, has been used successfully by different groups in the past. In this paper, we report on the porogen removal from porogenated SiOC:H films, using a hot wire chemical vapor deposition (HWCVD) equipment. Molecular hydrogen is dissociated into atomic hydrogen by the hot wires and these atoms may successfully remove the hydrocarbon groups from the porogenated SiOC:H films. The temperature of the HWCVD filaments proved to be a determining factor. By Fourier transform infrared spectroscopy, X-ray reflectivity (XRR), secondary ion mass spectrometry (SIMS), ellipsometric porosimetry and capacitance-voltage analyses, it was possible to determine that for temperatures higher than 1700 °C, efficient porogen removal occurred. For temperatures higher than 1800 °C, the presence of OH groups was detected. The dielectric constant was the lowest, 2.28, for the samples processed at a filament temperature of 1800 °C, although porosity measurements showed higher porosity for the films deposited at the higher temperatures. XRR and SIMS analyses indicated densification and Tungsten (W) incorporation at the top few nanometers of the films.

  6. Muonic atoms in super-intense laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Shahbaz, Atif

    2009-01-28

    Nuclear effects in hydrogenlike muonic atoms exposed to intense high-frequency laser fields have been studied. Systems of low nuclear charge number are considered where a nonrelativistic description applies. By comparing the radiative response for different isotopes we demonstrate characteristic signatures of the finite nuclear mass, size and shape in the high-harmonic spectra. Cutoff energies in the MeV domain can be achieved, offering prospects for the generation of ultrashort coherent {gamma}-ray pulses. Also, the nucleus can be excited while the laser-driven muon moves periodically across it. The nuclear transition is caused by the time-dependent Coulomb field of the oscillating charge density of the bound muon. A closed-form analytical expression for electric multipole transitions is derived within a fully quantum mechanical approach and applied to various isotopes. The excitation probabilities are in general very small. We compare the process with other nuclear excitation mechanisms through coupling with atomic shells and discuss the prospects to observe it in experiment. (orig.)

  7. Muonic atoms in super-intense laser fields

    International Nuclear Information System (INIS)

    Shahbaz, Atif

    2009-01-01

    Nuclear effects in hydrogenlike muonic atoms exposed to intense high-frequency laser fields have been studied. Systems of low nuclear charge number are considered where a nonrelativistic description applies. By comparing the radiative response for different isotopes we demonstrate characteristic signatures of the finite nuclear mass, size and shape in the high-harmonic spectra. Cutoff energies in the MeV domain can be achieved, offering prospects for the generation of ultrashort coherent γ-ray pulses. Also, the nucleus can be excited while the laser-driven muon moves periodically across it. The nuclear transition is caused by the time-dependent Coulomb field of the oscillating charge density of the bound muon. A closed-form analytical expression for electric multipole transitions is derived within a fully quantum mechanical approach and applied to various isotopes. The excitation probabilities are in general very small. We compare the process with other nuclear excitation mechanisms through coupling with atomic shells and discuss the prospects to observe it in experiment. (orig.)

  8. Nonradiative excitation of the muonic atom 238U as an inverse conversion process

    International Nuclear Information System (INIS)

    Karpeshin, F.F.; Nesterenko, V.U.

    1982-01-01

    The probabilities of nonradiation nuclear excitation are calculated for different muon transitions in the muonic atom 238 U. Microscopic nuclear wave functions, obtained within the quasiparticle-phonon nuclear model and the muonic conversion coefficients have been used. The probability of nonradiation nuclear excitation for the muonic transitions 2p → 1s and 3p → 1s has been found to be equal to 0.3. It is predicted that nonradiative E3 transitions 3d → 2p can take place with the probability 0.08-0.10. The dynamic effect of nuclear structure on the probability of nonradiative nuclear excitation is taken into account. The estimates of 238 U fissility fission branching at nonradiation transitions are also obtained

  9. Application of GAMESS/NEO to quantum calculations of muonic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Sheely, Eugene V; Burggraf, Larry W [Air Force Institute of Technology, AFIT/ENP, 2950 Hobson Way, Wright-Patterson Air Force Base, OH 45433 (United States); Adamson, Paul E [High Power Microwave (HPM) Technologies Branch, HPM Division, Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM 87117 (United States); Duan, Xiaofeng F [DoD Supercomputing Resource Center (DSRC), Air Force Research Laboratory, 2435 Fifth Street, Bldg 676, Wright-Patterson Air Force Base, OH 45433 (United States); Schmidt, Mike W, E-mail: Eugene.Sheely@afit.ed [Department of Chemistry, Iowa State University, 201 Spedding Hall, Ames, IA 50011 (United States)

    2010-04-01

    The General Atomic and Molecular Electronic Structure System (GAMESS) has been modified to perform studies involving negative muons. This system, coupled with the Nuclear-Electronic Orbital (NEO) method enables the ab-initio study of muonic atoms where both the negative muon and the positive nuclei are modeled as quantum particles. This is of particular usefulness in the study light nuclei, muonic atoms, such as is encountered in muon-catalyzed fusion. NEO was also modified to allow the inclusion of positive exotic-particles to be studied using open and closed shell Hartree-Fock and Configuration Interaction. Capitalizing on these modified methods, the muon density and vibrational dynamics of some light muonic molecules have been analyzed.

  10. Use of muonic x rays for nondestructive analysis of bulk samples for low Z constituents

    International Nuclear Information System (INIS)

    Reidy, J.J.; Hutson, R.L.; Daniel, H.; Springer, K.

    1978-01-01

    Muonic x rays have been used in quantitative analysis on bulk samples of ''tissue equivalent'' material whose primary constituents are low Z elements (Z less than or equal to 20). The muonic x-ray spectrum resulting from negative muons stopping in ''tissue equivalent'' materials has been obtained. Relative muonic x-ray intensities were determined and correlated with atomic abundances in these materials. A comparison of the results for the various samples is presented. This work establishes the usefulness of this technique for analyses of gross specimens (greater than or equal to few grams) for elements with 6 less than or equal to Z less than or equal to 20 and atomic abundances greater than 0.15 percent

  11. Muon cycling rate in D/T mixture including doubly muonic molecule formation

    Directory of Open Access Journals (Sweden)

    M. R. Eskandari

    2002-06-01

    Full Text Available   In the present work, the fundamental behavior of four body molecule formations of pt μμ , pd μμ , dt μμ , tt μμ , and pp μμ in a D/T fusion are considered. Their higher fusion rate, specially the available data for dt μμ , encouraged us to study the muon cycling rate in D/T fusion in the temperature range of (100-1400 K, density and deuterium-tritium concentration ratio. For this purpose, various values for the doubly muonic molecule formation are chosen and with the comparison to the experimental results, the doubly muonic formation rate of 109 s-1 is predicted theoretically. Our calculated cycling rate has shown that having not considered the doubly muonic formation in previous calculations had made no serious changes in the previously calculated values.

  12. Reanalysis of electron scattering and muonic x-ray data for 208Pb

    International Nuclear Information System (INIS)

    Frair, J.L.; Heisenberg, J.; Negele, J.W.

    1977-01-01

    A simultaneous analysis was performed for the world's supply of data on lead 208. A total of 14 sets of electron scattering data were analyzed along with six independent muonic transition energies. A previously used Fourier Bessel expansion program was expanded to include the full set of available data. The fit was done starting with the density distribution and using 13 expansion coeffients with a cutoff radius of 11 fm. The results are tabulated for muonic energy levels. Interior charge densities of lead 208, differential cross sections, per cent of experimental deviation from the fit, and charge density are plotted. 8 references

  13. Theoretical and computational study of the energy dependence of the muon transfer rate from hydrogen to higher-Z gases

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Tsarigradsko chaussée 72, Sofia 1784 (Bulgaria); Adamczak, Andrzej [Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Krakow (Poland); Stoilov, Mihail [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Tsarigradsko chaussée 72, Sofia 1784 (Bulgaria); Vacchi, Andrea [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Via A. Valerio 2, 34127 Trieste (Italy)

    2015-01-23

    The recent PSI Lamb shift experiment and the controversy about proton size revived the interest in measuring the hyperfine splitting in muonic hydrogen as an alternative possibility for comparing ordinary and muonic hydrogen spectroscopy data on proton electromagnetic structure. This measurement critically depends on the energy dependence of the muon transfer rate to heavier gases in the epithermal range. The available data provide only qualitative information, and the theoretical predictions have not been verified. We propose a new method by measurements of the transfer rate in thermalized target at different temperatures, estimate its accuracy and investigate the optimal experimental conditions. - Highlights: • Method for measuring the energy dependence of muon transfer rate to higher-Z gases. • Thermalization and depolarization of muonic hydrogen studied by Monte Carlo method. • Optimal experimental conditions determined by Monte Carlo simulations. • Mathematical model and for estimating the uncertainty of the experimental results.

  14. Determination of diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Komal Chandra, E-mail: komal@barc.gov.in [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kulkarni, A.S.; Ramanjaneyulu, P.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sunil, Saurav [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Saxena, M.K. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.N. [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S.; Ramakumar, K.L. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2015-06-15

    The diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr–2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H{sub 2}/D{sub 2} content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick’s second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as D{sub H} = 1.41 × 10{sup −7} exp(−36,000/RT) and D{sub D} = 6.16 × 10{sup −8} exp(−35,262/RT) for hydrogen and deuterium, respectively.

  15. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  16. The Lamb-shift experiment in Muonic helium

    Energy Technology Data Exchange (ETDEWEB)

    Nebel, T., E-mail: tbn@mpq.mpg.de [Max-Planck-Institut fuer Quantenoptik (Germany); Amaro, F. D. [Universidade de Coimbra, Departamento de Fisica (Portugal); Antognini, A. [Eidgenoessische Technische Hochschule Zuerich, Institut fuer Teilchenphysik (Switzerland); Biraben, F. [CNRS and Universite P. et M. Curie, Laboratoire Kastler Brossel, Ecole Normale Superieure (France); Cardoso, J. M. R. [Universidade de Coimbra, Departamento de Fisica (Portugal); Covita, D. S. [Universidade de Aveiro, I3N, Departamento de Fisica (Portugal); Dax, A. [University of Tokyo, Department of Physics (Japan); Fernandes, L. M. P.; Gouvea, A. L. [Universidade de Coimbra, Departamento de Fisica (Portugal); Graf, T. [Universitaet Stuttgart, Institut fuer Strahlwerkzeuge (Germany); Haensch, T. W. [Max-Planck-Institut fuer Quantenoptik (Germany); Hildebrandt, M. [Paul Scherrer Institut (Switzerland); Indelicato, P.; Julien, L. [CNRS and Universite P. et M. Curie, Laboratoire Kastler Brossel, Ecole Normale Superieure (France); Kirch, K.; Kottmann, F. [Eidgenoessische Technische Hochschule Zuerich, Institut fuer Teilchenphysik (Switzerland); Liu, Y.-W. [National Tsing Hua University, Physics Department (China); Monteiro, C. M. B. [Universidade de Coimbra, Departamento de Fisica (Portugal); and others

    2012-12-15

    We propose to measure several transition frequencies between the 2S and the 2P states (Lamb shift) in muonic helium ions ({mu}{sup 4}He{sup + } and {mu}{sup 3}He{sup + }) by means of laser spectroscopy, in order to determine the alpha-particle and helion root-mean-square (rms) charge radius. In addition, the fine and hyperfine structure components will be revealed, and the magnetic moment distribution radius will be determined. The contribution of the finite size effect to the Lamb shift (2S - 2P energy difference) in {mu}He{sup + } is as high as 20 %. Therefore a measurement of the transition frequencies with a moderate (for laser spectroscopy) precision of 50 ppm (corresponding to 1/20 of the linewidth) will lead to a determination of the nuclear rms charge radii with a relative accuracy of 3 Multiplication-Sign 10{sup - 4} (equivalent to 0.0005 fm). The limiting factor for the extraction of the radii from the Lamb shift measurements is given by the uncertainty of the nuclear polarizability contribution. Combined with an ongoing experiment at MPQ aiming to measure the 1S - 2S transition frequency in the helium ion, the Lamb shift measurement in {mu}He{sup + } will lead to a sensitive test of problematic and challenging bound-state QED terms. This measurement will also help to clarify the discrepancy found in our previous {mu}{sub p} experiment. Additionally, a precise knowledge of the absolute nuclear radii of the He isotopes and the hyperfine splitting of {mu}{sup 3}He{sup + } provide a relevant test of few-nucleon theories.

  17. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  18. Hot-Fire Test of Liquid Oxygen/Hydrogen Space Launch Mission Injector Applicable to Exploration Upper Stage

    Science.gov (United States)

    Barnett, Greg; Turpin, Jason; Nettles, Mindy

    2015-01-01

    This task is to hot-fire test an existing Space Launch Mission (SLM) injector that is applicable for all expander cycle engines being considered for the exploration upper stage. The work leverages investment made in FY 2013 that was used to additively manufacture three injectors (fig. 1) all by different vendors..

  19. The initial stages of the reaction between ZrCo and hydrogen studied by hot-stage microscopy

    International Nuclear Information System (INIS)

    Bloch, J.; Brill, M.; Ben-Eliahu, Y.; Gavra, Z.

    1998-01-01

    The development of hydride phase on the surface of ZrCo under 1 bar of hydrogen was investigated at temperatures between 75 and 300 C. Both surface modifications of the parent alloy and the nucleation and growth of hydride phase were observed. Surface modifications included: grain boundary outgrowth, intra-granular precipitation in the form of fine lamellar hydride phase and micro cracks. It is suggested that the surface modifications result from a combination of hydrogen solubility and the parent metal ductility. These modifications were enhanced near areas which had been previously transformed. The nucleation was self catalyzed, with new nuclei preferentially formed at the vicinity of growing former nuclei. All this suggested that the transport of hydrogen through the hydride phase is faster than its transfer through the surface passivation layer. The growth rate of the nuclei was similar to that of uranium. The activation energy for the growth was E a =24±3 kJ/mol. The results were compared with several other metal-hydrogen systems. It is suggested that the important physical factors controlling the mechanism of the initial hydriding reaction are hydrogen solubility and the brittleness of the parent metal/alloy. These parameters are responsible to the different changes observed during the initial hydriding stages which include: surface modifications, cracking, nucleation and growth. (orig.)

  20. Pionic hydrogen and friends

    Energy Technology Data Exchange (ETDEWEB)

    Gotta, D., E-mail: d.gotta@fz-juelich.de [Forschungszentrum Jülich GmbH and JHCP (Germany); Amaro, F. D. [Coimbra University, Department of Physics (Portugal); Anagnostopoulos, D. F. [University of Ioannina, Department of Materials Science and Engineering (Greece); Bühler, P. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Gorke, H. [Forschungszentrum Jülich GmbH and JHCP (Germany); Covita, D. S. [Coimbra University, Department of Physics (Portugal); Fuhrmann, H.; Gruber, A. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Hennebach, M. [Forschungszentrum Jülich GmbH and JHCP (Germany); Hirtl, A.; Ishiwatari, T. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Indelicato, P. [LKB, UPMC-Paris 6, ENS, CNRS (France); Jensen, T. S. [Ringkjøbing Gymnasium (Denmark); Bigot, E.-O. Le [LKB, UPMC-Paris 6, ENS, CNRS (France); Markushin, V. E. [Paul Scherrer Institut (PSI) (Switzerland); Marton, J. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Nekipelov, M. [Forschungszentrum Jülich GmbH and JHCP (Germany); Pomerantsev, V. N.; Popov, V. P. [Skobeltsyn Institut of Nuclear Physics, Lomonossov Moscow State University (Russian Federation); Santos, J. M. F. dos [Coimbra University, Department of Physics (Portugal); and others

    2015-08-15

    Pion-nucleon scattering lengths are directly related to the ground-state level shift and broadening in pionic hydrogen as well as to the pionic deuterium level shift. The level broadening in deuterium measures the strength of pion threshold-production in proton-proton reactions. However, collisional processes during the atomic de-excitation cascade considerably complicate the analysis of X-ray line shapes in order to extract the hadronic broadening. Therefore, additionally the purely electromagnetic twin system muonic hydrogen was studied. Results of these experiments performed at PSI by using a high-resolution crystal spectrometer are discussed in the context with a new analysis approach for the hadronic broadening.

  1. Energy, The Storage Challenge. Better Batteries Included. Running Hot and Cold. A Tank-full of Hydrogen

    International Nuclear Information System (INIS)

    Bourdet, Julien; Hait, Jean-Francois; Demarthon, Fabrice; Brault, Pascal; Dollet, Alain; Py, Olivier; Tarascon, Jean-Marie; Gonbeau, Danielle; Simon, Patrice; Pourcelly, Gerald; Latroche, Michel; Rango, Patricia de; Miraglia, Salvatore

    2013-01-01

    To secure its future and that of the planet, humanity must find alternatives to oil. But this vital transition toward renewable energy (currently the subject of a national debate in France), is highly dependent on the development of efficient storage solutions. Today's technologies make it relatively easy to produce electricity, heat, and even hydrogen, but their long-term storage remains a daunting scientific and technical challenge-a high priority for CNRS researchers

  2. Method of investigation of nuclear reactions in charge-nonsymmetrical muonic complexes

    CERN Document Server

    Bystritsky, V M; Penkov, F M

    1999-01-01

    A method for experimental determination of the nuclear fusion rates in the d mu He molecules in the states with J=0 and J=1 (J is the orbital moment of the system) and of the effective rate of transition between these states (rotational transition 1-0) is proposed. It is shown that information on the desired characteristics can be found from joint analysis of the time distribution and yield of products of nuclear fusion reactions in deuterium-helium muonic molecules and muonic X-ray obtained in experiments with the D sub 2 +He mixture at three (and more) appreciably different densities. The planned experiments with the D sub 2 +He mixture at the meson facility PSI (Switzerland) are optimized to gain more accurate information about the desired parameters on the assumption that different mechanisms for the 1-0 transition of the d mu He complex are realized. (author)

  3. Nuclear charge radii of the 1fsub(7/2) shell nuclei from muonic atoms

    International Nuclear Information System (INIS)

    Wohlfahrt, H.D.

    1979-01-01

    Muonic X-ray of medium-weight nuclei have been performed in recent years by the Los Alamos muonic X-ray group, using the high intensity muon beam available at the LAMPF 800 MeV proton accelerator. These studies, which together include all stable 1fsub(7/2) neutron shell nuclei, provide information about the proton core polarization due to the successive addition of neutrons for the proton cores Z = 20 (Ca), 22 (Ti), 24(Cr), 26(Fe) and 28(Ni). In addition, these studies, which represent the first systematic investigations of isotone shifts, provide the opportunity to compare the core polarization caused by protons with core polarization caused by neutrons in the same (1fsub(7/2)) shell. (KBE)

  4. An experimental study of muonic X-ray transitions in mercury isotopes

    International Nuclear Information System (INIS)

    Hahn, A.A.; Miller, J.P.; Powers, R.J.; Zehnder, A.; Rushton, A.M.; Welsh, R.E.; Kunselman, A.R.; Roberson, P.; Walter, H.K.

    1979-01-01

    Muonic X-ray spectra have been measured for 198-202 204 Hg. These data have been interpreted in terms of a two parameter Fermi distribution for the charge density. The authors have inferred the spectroscopic quadrupole moments of some of the 2 + nuclear states. For 199 Hg they have determined the spectroscopic quadrupole moments of the first two excited states and the B(E2) connecting these states to the ground state. For 201 Hg the ground state quadrupole moment has been obtained as well as several other E2 moments but the interpretation of the data has been hampered by a possible incomplete knowledge of the nuclear scheme of this nucleus. The muonic isotope shifts have been measured and interpreted in terms of deltaRsub(k) and are compared to electronic X-ray and optical isotope shift measurements. (Auth.)

  5. Quadrupole corrections to matrix elements of transitions in resonant reactions of muonic molecule formation

    International Nuclear Information System (INIS)

    Faifman, M.P.; Strizh, T.A.; Armour, E.A.G.; Harston, M.R.

    1996-01-01

    The calculated resonant formation rates of the muonic molecules DDμ and DTμ are presented. The approach developed earlier for calculating the transition matrix elements in the dipole approximation has been extended to include the quadrupole terms in the multipole expansion of the interaction operator. The calculated dependence of the DTμ formation rates on the energies of the incident Tμ muonic atoms shows that the effect of including the quadrupole correction is to reduce the magnitude of the peak rates by about 20-30% at the different temperatures, compared to those calculated in the dipole approximation. The dependence on temperature for the DDμ formation rates is obtained with the differences between the presented and previous calculations being less than 5%. (orig.)

  6. Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Joonoh, E-mail: mjo99@kims.re.kr [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju [Sheet Products Design Team, Technical Research Center, Hyundai Steel Company, 1480 Bukbusaneop-ro, Dangjin, Chungnam 343-823 (Korea, Republic of); Lee, Chang-Hoon; Lee, Tae-Ho [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of)

    2016-01-15

    Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M{sub 3}C→MX→MX+M{sub 7}C{sub 3}+M{sub 23}C{sub 6}. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M{sub 3}C particle, and increased after 10 min by the precipitation of M{sub 7}C{sub 3} and M{sub 23}C{sub 6} particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M{sub 7}C{sub 3} particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M{sub 23}C{sub 6} and M{sub 7}C{sub 3} particles deteriorated the HIC resistance.

  7. Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

    International Nuclear Information System (INIS)

    Moon, Joonoh; Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju; Lee, Chang-Hoon; Lee, Tae-Ho

    2016-01-01

    Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M_3C→MX→MX+M_7C_3+M_2_3C_6. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M_3C particle, and increased after 10 min by the precipitation of M_7C_3 and M_2_3C_6 particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M_7C_3 particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M_2_3C_6 and M_7C_3 particles deteriorated the HIC resistance.

  8. Search for two-photon emission from 2S states of low-Z muonic atoms

    International Nuclear Information System (INIS)

    Carter, A.L.; Hincks, E.P.; Cox, C.R.; Dodson, G.W.; Eckhause, M.; Kane, J.R.; Rushton, A.M.; Siegel, R.T.; Welsh, R.E.; Hargrove, C.K.; Mes, H.; Dixit, M.S.; National Research Council of Canada, Ottawa, Ontario)

    1983-01-01

    A search for two-photon emission from 2S states of low-Z muonic atoms has been made. Intrinsic Ge detectors were positioned around target of Li, Be, B, or their hydrides, or a vessel containing B 2 H 6 , H 2 , or O 2 . Upper limits on the fraction of stopping muons which formed metastable 2S states range from approx.= 10 - 3 to 10 - 5 . (orig.)

  9. Search for two-photon emission from 2S states of low-Z muonic atoms

    Energy Technology Data Exchange (ETDEWEB)

    Carter, A.L.; Hincks, E.P. (Carleton Univ., Ottawa, Ontario (Canada). Dept. of Physics); Cox, C.R.; Dodson, G.W.; Eckhause, M.; Kane, J.R.; Rushton, A.M.; Siegel, R.T.; Welsh, R.E. (College of William and Mary, Williamsburg, VA (USA). Dept. of Physics); Hargrove, C.K.

    1983-05-12

    A search for two-photon emission from 2S states of low-Z muonic atoms has been made. Intrinsic Ge detectors were positioned around target of Li, Be, B, or their hydrides, or a vessel containing B/sub 2/H/sub 6/, H/sub 2/, or O/sub 2/. Upper limits on the fraction of stopping muons which formed metastable 2S states range from approximately = 10/sup -3/ to 10/sup -5/.

  10. Hyperfine structure of the S- and P-wave states of muonic deuterium

    International Nuclear Information System (INIS)

    Martynenko, A. P.; Martynenko, G. A.; Sorokin, V. V.; Faustov, R. N.

    2016-01-01

    Corrections of order α"5 and α"6 to the hyperfine structure of the S- and P-wave states of muonic deuteriumwere calculated on the basis of the quasipotential approach in quantum electrodynamics. Relativistic corrections, vacuum-polarization and deuteron-structure effects, and recoil corrections were taken into account in this calculation. The resulting hyperfine-splitting values can be used in a comparison with experimental data obtained by the CREMA Collaboration.

  11. Elastic electron scattering at low momentum transfer and muonic X-rays

    International Nuclear Information System (INIS)

    Barrett, R.C.

    Mean square charge radius obtained at low momentum transfer is discussed in model-independent way. Muonic X-ray energies and form factors being expressed in terms of generalized moments of the charge density, the linear constraint functions from Friar and Negele are used to obtain an idea of the model-dependent error, r 2 . 208 Pb, 4 Ca and 4 He are considered as examples

  12. Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

    Directory of Open Access Journals (Sweden)

    Ji Chen

    2016-01-01

    Full Text Available We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

  13. Study of X-rays and nuclear gamma -rays in muonic thallium

    CERN Document Server

    Backe, H; Jahnke, U; Kankeleit, E; Pearce, R M; Petitjean, C; Schellenberg, L; Schneuwly, H; Schröder, W U; Walter, H K; Zehnder, A

    1972-01-01

    Energies and intensities of muonic X-rays, nuclear gamma -rays and mu -capture gamma -rays were measured in natural muonic thallium with Ge (Li) detectors. The absolute intensities of higher mu X-rays were reproduced by a cascade calculation starting with a statistical population at n=20 including K-, L- and M-conversion. The electron screening effect was deduced from energies of higher mu X-rays. Eight prompt nuclear gamma -rays were found. This excitation explains the anomalous intensity ratios of the 2p-1s and 3d-2p fine structure components. From the nuclear gamma -rays of the first excited states were deduced: the magnetic h.f. splittings, muonic isomer shifts E2/M1 mixing ratios and the half-life in the presence of the muon in /sup 205/Tl. Evidence for a magnetic nuclear polarization was found. An isotope shift of Delta E=10.35+or-0.25 keV was measured for the 1s/sub 1/2/ state which is compared with data from optical spectroscopy. From an analysis of the time distribution of delayed gamma -rays from mu...

  14. Effective electronic-only Kohn–Sham equations for the muonic molecules

    Science.gov (United States)

    Rayka, Milad; Goli, Mohammad; Shahbazian, Shant

    A set of effective electronic-only Kohn-Sham (EKS) equations are derived for the muonic molecules (containing a positively charged muon), which are completely equivalent to the coupled electronic-muonic Kohn-Sham equations derived previously within the framework of the Nuclear-Electronic Orbital density functional theory (NEO-DFT). The EKS equations contain effective non-coulombic external potentials depending on parameters describing muon vibration, which are optimized during the solution of the EKS equations making muon KS orbital reproducible. It is demonstrated that the EKS equations are derivable from a certain class of effective electronic Hamiltonians through applying the usual Hohenberg-Kohn theorems revealing a duality between the NEO-DFT and the effective electronic-only DFT methodologies. The EKS equations are computationally applied to a small set of muoniated organic radicals and it is demonstrated that a mean effective potential maybe derived for this class of muonic species while an electronic basis set is also designed for the muon. These computational ingredients are then applied to muoniated ferrocenyl radicals, which had been previously detected experimentally through adding muonium atom to ferrocene. In line with previous computational studies, from the six possible species the staggered conformer, where the muon is attached to the exo position of the cyclopentadienyl ring, is deduced to be the most stable ferrocenyl radical.

  15. Effective electronic-only Kohn-Sham equations for the muonic molecules.

    Science.gov (United States)

    Rayka, Milad; Goli, Mohammad; Shahbazian, Shant

    2018-03-28

    A set of effective electronic-only Kohn-Sham (EKS) equations are derived for the muonic molecules (containing a positively charged muon), which are completely equivalent to the coupled electronic-muonic Kohn-Sham equations derived previously within the framework of the nuclear-electronic orbital density functional theory (NEO-DFT). The EKS equations contain effective non-coulombic external potentials depending on parameters describing the muon's vibration, which are optimized during the solution of the EKS equations making the muon's KS orbital reproducible. It is demonstrated that the EKS equations are derivable from a certain class of effective electronic Hamiltonians through applying the usual Hohenberg-Kohn theorems revealing a "duality" between the NEO-DFT and the effective electronic-only DFT methodologies. The EKS equations are computationally applied to a small set of muoniated organic radicals and it is demonstrated that a mean effective potential may be derived for this class of muonic species while an electronic basis set is also designed for the muon. These computational ingredients are then applied to muoniated ferrocenyl radicals, which had been previously detected experimentally through adding a muonium atom to ferrocene. In line with previous computational studies, from the six possible species, the staggered conformer, where the muon is attached to the exo position of the cyclopentadienyl ring, is deduced to be the most stable ferrocenyl radical.

  16. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn2O3 sorbents

    International Nuclear Information System (INIS)

    Zhang, Z.F.; Liu, B.S.; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-01-01

    Graphical abstract: - Highlights: • Mn 2 O 3 /KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn 2 O 3 /KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn 2 O 3 sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn 2 O 3 sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H 2 S. The fresh and used sorbents were characterized by means of N 2 -adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H 2 temperature- programmed reduction (H 2 -TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn 2 O 3 /diatomite, all mesoporous silica supported Mn 2 O 3 sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn 2 O 3 /MCM-41 and Mn 2 O 3 /HMS sorbent, the Mn 2 O 3 /KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn 2 O 3 /KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn 2 O 3 /KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  17. Exchange and polarization effects in the elementary excitation spectrum of a hydrogen atom immersed in a hot plasma

    International Nuclear Information System (INIS)

    Dharma-wardana, M.W.C.; Grimaldi, F.; Lecourt, A.; Pellissier, J.

    1980-01-01

    The one-particle hydrogenic Green's function has been calculated for a partially ionized plasma consisting of hydrogen atoms, electrons, and protons at high temperatures. The theoretical method extends a previous publication and involves an evaluation of the mass operator in the Dyson equation to include proper self-energy parts to ''all orders'' in the screened interaction. This mass operator characterizes the effective micropotential felt by the atom in the plasma and determines all of the one-particle properties and some two-particle properties associated with the atomic subsystem. The first-order mass operator is nonzero only for exchange scattering, which leads to a frequency-independent exchange shift. This temperature- and density-dependent theory of the exchange shift replaces the usual semiphenomenological schemes based on the Slater-Kohn-Sham type of theory. The exchange-shifted Green's functions are used in evaluating the higher-order contributions. Computer calculations and the resolution of the poles of the Green's function lead to level shifts, widths, and spectral functions. These are calculated within both the second-order and the all-order theory. The second-order theory, which may be valid at sufficiently high densities and in turbulent plasmas, overemphasises the atom-plasmon coupling and shows new structures. The inclusion of contributions beyond second order removes these structures and produces a more ''conventional'' spectral-intensity function. The effects of center-of-mass motion on the level shifts and level profiles are investigated and the onset of plasma instabilities touched upon. These calculations make contact with the work on ''plasma-polarization shifts'' and provide an approach to q,ω-dependent plasma microfields

  18. Hydrogen-producing microflora and Fe-Fe hydrogenase diversities in seaweed bed associated with marine hot springs of Kalianda, Indonesia.

    Science.gov (United States)

    Xu, Shou-Ying; He, Pei-Qing; Dewi, Seswita-Zilda; Zhang, Xue-Lei; Ekowati, Chasanah; Liu, Tong-Jun; Huang, Xiao-Hang

    2013-05-01

    Microbial fermentation is a promising technology for hydrogen (H(2)) production. H(2) producers in marine geothermal environments are thermophilic and halotolerant. However, no one has surveyed an environment specifically for thermophilic bacteria that produce H(2) through Fe-Fe hydrogenases (H(2)ase). Using heterotrophic medium, several microflora from a seaweed bed associated with marine hot springs were enriched and analyzed for H(2) production. A H(2)-producing microflora was obtained from Sargassum sp., 16S rRNA genes and Fe-Fe H(2)ase diversities of this enrichment were also analyzed. Based on 16S rRNA genes analysis, 10 phylotypes were found in the H(2)-producing microflora showing 90.0-99.5 % identities to known species, and belonged to Clostridia, Gammaproteobacteria, and Bacillales. Clostridia were the most abundant group, and three Clostridia phylotypes were most related to known H(2) producers such as Anaerovorax odorimutans (94.0 % identity), Clostridium papyrosolvens (98.4 % identity), and Clostridium tepidiprofundi (93.1 % identity). For Fe-Fe H(2)ases, seven phylotypes were obtained, showing 63-97 % identities to known Fe-Fe H(2)ases, and fell into four distinct clusters. Phylotypes HW55-3 and HM55-1 belonged to thermophilic and salt-tolerant H(2)-producing Clostridia, Halothermothrix orenii-like Fe-Fe H(2)ases (80 % identity), and cellulolytic H(2)-producing Clostridia, C. papyrosolvens-like Fe-Fe H(2)ases (97 % identity), respectively. The results of both 16S rRNA genes and Fe-Fe H(2)ases surveys suggested that the thermophilic and halotolerant H(2)-producing microflora in seaweed bed of hot spring area represented previously unknown H(2) producers, and have potential application for H(2) production.

  19. Steam regenerative removal of hydrogen sulfide from hot syngas by a novel tin oxide and yttrium oxide sorbent

    International Nuclear Information System (INIS)

    Yang, Yi; Shi, Yixiang; Cai, Ningsheng

    2017-01-01

    A novel H 2 S sorbent based on SnO 2 and Y 2 O 3 is developed by a co-precipitation method for steam regenerative removal of H 2 S from hot syngas at moderate temperatures (400–500 °C). SnO 2 -Y 2 O 3 sorbent is stable in a reducing atmosphere (i.e. 500 °C, 50% H 2 ) and achieves a 99.9% H 2 S removal during successive desulfurization and regeneration cycles. The addition of yttrium to SnO 2 decreases the reduction property of SnO 2 and no metallic Sn exists in the reducing atmosphere due to the formation of a pyrochlore-type compound, Y 2 Sn 2 O 7 . The SnO 2 -Y 2 O 3 sorbent has a desulfurization performance deterioration with the increasing calcination temperature. The newly developed SnO 2 -Y 2 O 3 sorbent can be regenerated by steam at 500 °C. In the eight successive desulfurization and regeneration cycles, SnO 2 -Y 2 O 3 sorbent has a cyclic breakthrough sulfur capacity of 9 mg/g without significant sulfur capacity loss. - Highlights: • Reversible warm gas H 2 S clean up. • Suppressing SnO 2 reduction by formation of Sn 2 Y 2 O 7 . • Sn2Y-700 steam regeneration and cycling characterization.

  20. The influence of charge effect on the growth of hydrogenated amorphous silicon by the hot-wire chemical vapor deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.; Nelson, B.P.; Iwaniczko, E.; Mahan, A.H.; Crandall, R.S.; Benner, J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    The authors observe at lower substrate temperatures that the scatter in the dark conductivity on hydrogenated amorphous silicon (a-Si:H) films grown on insulating substrates (e.g., Corning 7059 glass) by the hot-wire chemical vapor deposition technique (HWCVD) can be five orders of magnitude or more. This is especially true at deposition temperatures below 350 C. However, when the authors grow the same materials on substrates with a conductive grid, virtually all of their films have acceptable dark conductivity (< 5 {times} 10{sup {minus}10} S/cm) at all deposition temperatures below 425 C. This is in contrast to only about 20% of the materials grown in this same temperature range on insulating substrates having an acceptable dark conductivity. The authors estimated an average energy of 5 eV electrons reaching the growing surface in vacuum, and did additional experiments to see the influence of both the electron flux and the energy of the electrons on the film growth. Although these effects do not seem to be important for growing a-Si:H by HWCVD on conductive substrates, they help better understand the important parameters for a-Si:H growth, and thus, to optimize these parameters in other applications of HWCVD technology.

  1. Growth of boron doped hydrogenated nanocrystalline cubic silicon carbide (3C-SiC) films by Hot Wire-CVD

    Energy Technology Data Exchange (ETDEWEB)

    Pawbake, Amit [School of Energy Studies, Savitribai Phule Pune University, Pune 411 007 (India); Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Mayabadi, Azam; Waykar, Ravindra; Kulkarni, Rupali; Jadhavar, Ashok [School of Energy Studies, Savitribai Phule Pune University, Pune 411 007 (India); Waman, Vaishali [Modern College of Arts, Science and Commerce, Shivajinagar, Pune 411 005 (India); Parmar, Jayesh [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Bhattacharyya, Somnath [Department of Metallurgical and Materials Engineering, IIT Madras, Chennai 600 036 (India); Ma, Yuan‐Ron [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China); Devan, Rupesh; Pathan, Habib [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Jadkar, Sandesh, E-mail: sandesh@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

    2016-04-15

    Highlights: • Boron doped nc-3C-SiC films prepared by HW-CVD using SiH{sub 4}/CH{sub 4}/B{sub 2}H{sub 6}. • 3C-Si-C films have preferred orientation in (1 1 1) direction. • Introduction of boron into SiC matrix retard the crystallanity in the film structure. • Film large number of SiC nanocrystallites embedded in the a-Si matrix. • Band gap values, E{sub Tauc} and E{sub 04} (E{sub 04} > E{sub Tauc}) decreases with increase in B{sub 2}H{sub 6} flow rate. - Abstract: Boron doped nanocrystalline cubic silicon carbide (3C-SiC) films have been prepared by HW-CVD using silane (SiH{sub 4})/methane (CH{sub 4})/diborane (B{sub 2}H{sub 6}) gas mixture. The influence of boron doping on structural, optical, morphological and electrical properties have been investigated. The formation of 3C-SiC films have been confirmed by low angle XRD, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy and high resolution-transmission electron microscopy (HR-TEM) analysis whereas effective boron doping in nc-3C-SiC have been confirmed by conductivity, charge carrier activation energy, and Hall measurements. Raman spectroscopy and HR-TEM analysis revealed that introduction of boron into the SiC matrix retards the crystallanity in the film structure. The field emission scanning electron microscopy (FE-SEM) and non contact atomic force microscopy (NC-AFM) results signify that 3C-SiC film contain well resolved, large number of silicon carbide (SiC) nanocrystallites embedded in the a-Si matrix having rms surface roughness ∼1.64 nm. Hydrogen content in doped films are found smaller than that of un-doped films. Optical band gap values, E{sub Tauc} and E{sub 04} decreases with increase in B{sub 2}H{sub 6} flow rate.

  2. Muonic molecular ions p p μ and p d μ driven by superintense VUV laser pulses: Postexcitation muonic and nuclear oscillations and high-order harmonic generation

    Science.gov (United States)

    Paramonov, Guennaddi K.; Saalfrank, Peter

    2018-05-01

    The non-Born-Oppenheimer quantum dynamics of p p μ and p d μ molecular ions excited by ultrashort, superintense VUV laser pulses polarized along the molecular axis (z ) is studied by the numerical solution of the time-dependent Schrödinger equation within a three-dimensional (3D) model, including the internuclear distance R and muon coordinates z and ρ , a transversal degree of freedom. It is shown that in both p p μ and p d μ , muons approximately follow the applied laser field out of phase. After the end of the laser pulse, expectation values , , and demonstrate "post-laser-pulse" oscillations in both p p μ and p d μ . In the case of p d μ , the post-laser-pulse oscillations of and appear as shaped "echo pulses." Power spectra, which are related to high-order harmonic generation (HHG), generated due to muonic and nuclear motion are calculated in the acceleration form. For p d μ it is found that there exists a unique characteristic frequency ωoscp d μ representing both frequencies of post-laser-pulse muonic oscillations and the frequency of nuclear vibrations, which manifest themselves by very sharp maxima in the corresponding power spectra of p d μ . The homonuclear p p μ ion does not possess such a unique characteristic frequency. The "exact" dynamics and power, and HHG spectra of the 3D model are compared with a Born-Oppenheimer, fixed-nuclei model featuring interesting differences: postpulse oscillations are absent and HHG spectra are affected indirectly or directly by nuclear motion.

  3. Negative muon spin precession measurement of the hyperfine states of muonic sodium

    International Nuclear Information System (INIS)

    Brewer, J.H.; Ghandi, K.; Froese, A.M.; Fryer, B.A.

    2005-01-01

    Both hyperfine states of muonic 23 Na and the rate R of conversion between them have been observed directly in a high field negative muon spin precession experiment using a backward muon beam with transverse spin polarization. The result in metallic sodium, R=13.7±2.2 μs -1 , is consistent with Winston's prediction in 1963 based on Auger emission of core electrons, and with the measurements of Gorringe et al. in Na metal, but not with their smaller result in NaF. In NaOH we find R=23.5±8 μs -1 , leaving medium-dependent effects ambiguous

  4. Estimation of error in using born scaling for collision cross sections involving muonic ions

    International Nuclear Information System (INIS)

    Stodden, C.D.; Monkhorst, H.J.; Szalewicz, K.

    1988-01-01

    A quantitative estimate is obtained for the error involved in using Born scaling to calcuated excitation and ionization cross sections for collisions between muonic ions. The impact parameter version of the Born Approximation is used to calculate cross sections and Coulomb corrections for the 1s→2s excitation of αμ in collisions with d. An error of about 50% is found around the peak of the cross section curve. The error falls to less than 5% for velocities above 2 a.u

  5. The use of muonic atoms in biomedical researches (review)

    International Nuclear Information System (INIS)

    Sabirov, E.M.

    1984-01-01

    The review based on the experimental works of USA, West Germany scientists, the scientists of LNP JINR, shows the possibilities of muon atom application for comparative element analysis in biology and medicine. The unique and wide possibilities of muon diagnosis method are shown. Experiments both in vitro and in vivo were conducted. Investigation resulted in demonstration of variation of C, N, O amount in investigated tissue samples; the relative oxygen content grows in progression: adipose tissue, muscular tissue, liuer, blood. It is shown that the method enables to determine the content of any element no matter in what chemical compound this element enters. The method of muon atoms has some advantages as compared with other nuclear physics methods. Method restriction lies in the absence of high-intensive meson beams, which is related to method sensitivity. Another disadvantage consists in impossibility to register hydrogen therefore the method must be expanded by other methods of analysis for the purpose of investigation of different functional changes in organism

  6. Magnetization distribution of single-particle states and 2/sup +/ rotational states from muonic atoms

    CERN Document Server

    Backe, H; Engfer, R; Kankeleit, E; Link, R; Michaelsen, R; Petitjean, C; Schellenberg, L; Schneuwly, H; Schröder, W U; Vuilleumier, J L; Walter, H K; Zehnder, A

    1973-01-01

    The lowest states in muonic atoms are rather sensitive to the spatial distribution of the nuclear magnetization density, and several results were deduced from the broadening of the muonic 2p/sub 1/2/-1s/sub 1/2/ and 3d/sub 3/2/-2p/sub 1/2/ transitions. By measuring low energetic transitions such as the 2s/sub 1/2/-2p/sub 1/2/ transition or nuclear gamma -transitions, it is possible to resolve the magnetic hyperfine splittings. The magnetic hf splitting of the 2s/sub 1/2/-2p/sub 1/2/ transition in mu /sup 115/In and of the 3/2/sup +/-1/2/sup +/ nuclear gamma -transitions in mu /sup 203/Tl at 279 keV, and in mu /sup 205/Tl at 204 keV, have been resolved. For the 2/sup +/-0/sup +/ nuclear gamma -transition in mu /sup 190,192/Os at 187 keV and 206 keV, respectively, the magnetic hf splitting of the 2/sup +/ rotational levels and the intensities of the hf components were determined from a nearly resolved doublet splitting. (7 refs).

  7. Hot Flashes

    Science.gov (United States)

    Hot flashes Overview Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. Hot flashes can also cause sweating, and if you ...

  8. HOT 2015

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    2016-01-01

    HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud.......HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud....

  9. Observation of the muonic decay of the charged intermediate vector boson

    International Nuclear Information System (INIS)

    Arnison, G.; Astbury, A.; Grayer, G.; Haynes, W.J.; Nandi, A.K.; Roberts, C.; Scott, W.; Shah, T.P.; Bezaguet, A.; Bock, R.K.; Calvetti, M.; Cennini, P.; Cittolin, S.; Dallman, D.; Demoulin, M.; DiBitonto, D.; Ellis, N.; Hoffmann, H.; Jank, W.; Jorat, G.; Leveque, A.; Maurin, G.; Muller, F.; Naumann, L.; Norton, A.; Pauss, F.; Placci, A.; Porte, J.P.; Revol, J.P.; Rijssenbeek, M.; Rossi, P.; Rubbia, C.; Sadoulet, B.; Schinzel, D.; Sumorok, K.; Timmer, J.; Vuillemin, V.; Xie, Y.G.; Zurfluh, E.; Kryn, D.; Cochet, C.; DeBeer, M.; Denegri, D.; Givernaud, A.; Laugier, J.P.; Locci, E.; Malosse, J.J.; Rich, J.; Sass, J.; Saudraix, J.; Savoy-Navarro, A.; Spiro, M.; Dobrzynski, L.; Fontaine, G.; Ghesquiere, C.; Giraud-Heraud, Y.; Mendiburu, J.P.; Orkin-Lecourtois, A.; Sajot, G.; Tao, C.; Vrana, J.; Hertzberger, L.O.; Holthuizen, D.J.; Eijk, B. van; Bacci, C.; Ceradini, F.; Di Ciaccio, A.; Lacava, F.; Moricca, M.; Paoluzi, L.; Piano Mortari, G.; Salvini, G.; Bauer, G.; Cline, D.; Markiewicz, T.; Mohammadi, M.; Centro, S.; Corden, M.; Dowell, J.D.; Garvey, J.; Homer, R.J.; Kenyon, I.; McMahon, T.; Streets, J.; Watkins, P.; Wilson, J.; Eggert, K.; Erhard, P.; Faissner, H.; Giboni, K.L.; Hansl-Kozanecka, T.; Hoffmann, D.; Lehmann, H.; Leuchs, R.; Radermacher, E.; Reithler, H.; Tscheslog, E.; Fincke, M.; Muirhead, H.; Frey, R.; Kernan, A.; Kozanecki, W.; Morgan, K.; Ransdell, J.; Smith, D.; Fruehwirth, R.; Dallman, D.; Strauss, J.; Szoncso, F.; Wahl, H.D.; Wulz, C.E.; Geer, S.; Rohlf, J.; Karimaeki, V.; Kinnunen, R.; Pietarinen, E.; Pimiae, M.; Tuominiemi, J.

    1984-01-01

    Muons of high transverse momentum psub(T)sup(μ) have been observed in the large drift chambers surrounding the UA1 detector at the CERN 540 GeV panti p collider. For an integrated luminosity of 108 nb -1 , 14 isolated muons have been found with psub(T) > 15 GeV/c. They are correlated with a large imbalance in total transverse energy, and show a kinematic behaviour consistent with the muonic decay of the Intermediate Vector Boson Wsup(+-) of weak interactions. The partial cross section is in agreement with previous measurements for electronic decays and with muon-electron universality. The W mass is determined to be msub(W) = 81sub(-7) +6 GeV/c 2 . (orig.)

  10. Hyperfine structure of the S levels of the muonic helium ion

    International Nuclear Information System (INIS)

    Martynenko, A. P.

    2008-01-01

    Corrections of the α 5 and α 6 orders to the energy spectrum of the hyperfine splitting of the 1S and 2S levels of the muonic helium ion are calculated with the inclusion of the electron vacuum polarization effects, nuclear-structure corrections, and recoil effects. The values ΔE hfs (1S) = -1334.56 meV and ΔE hfs (2S) = -166.62 meV obtained for hyperfine splitting values can be considered as reliable estimates for comparison with experimental data. The hyperfine structure interval Δ 12 = 8ΔE hfs (2S) - ΔE hfs (1S) = 1.64 meV can be used to verify QED predictions

  11. Nuclear charge radii from X-ray transitions in muonic C, O and N

    CERN Document Server

    Dubler, T; Schellenberg, L; Schneuwly, H; Vuilleumier, J L; Walter, H K

    1973-01-01

    Energies of muonic X-rays permit an almost model independent determination of nuclear root mean square (rms) radii for light and medium nuclei, which can be compared to those obtained from elastic electron scattering experiments at low momentum transfer. In the present experiment the X-ray energies of the K series of C, N and O up to the 6p-1s transition are determined with an accuracy of +or-15 eV from which rms radii are deduced comparable in precision to the electron scattering data. Muons from the CERN muon channel were stopped in a target, which contained 70 gr dimethylglyoxim (C/sub 4/H /sub 8/N/sub 2/O/sub 2/) and 18 gr rhodium powder. (0 refs).

  12. Theory of muonic molecule formation: survey of progress and open questions

    International Nuclear Information System (INIS)

    Leon, M.

    1993-01-01

    The Auger mechanism of muonic molecule formation is operative for all the isotopic reactions channels, and the agreement between theory and experiment is quite good for all the observable reactions. For ddμ and dtμ formation, however, the resonance mechanism of Vesman is dominant and produces some dramatic effects. For ddμ, the temperature dependences for the different hyperfine states provide a striking confirmation of the theory. For dtμ, the comparison with experimental is much more difficult, and furthermore the appearance of an evident three-body contribution to the formation cross section presents a formidable challenge to theory. A completely convincing and practical method of calculating this term has yet to be achieved, but a classical trajectory model which provides some insight into the underlying physics is presented. (orig.)

  13. Obtaining muonic density estimates via application of matrix formalism to proposed surface detector upgrade at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, David; Engel, Ralph; Roth, Markus [Karlsruhe Institute of Technology, Karlsruhe (Germany); Collaboration: Pierre Auger-Collaboration

    2015-07-01

    Event-by-event identification of cosmic ray primary composition lends itself to enhanced event selection in the search for anisotropic arrival directions. Principally, the number of muons reaching Earth's surface in an extensive air shower is indicative of composition. The Pierre Auger Observatory seeks to capitalize on this axiom by improving reconstructed muonic density estimates via an upgrade to its surface detector array. This upgrade, consisting of placing a scintillator on top of each existing water Cherenkov detector, exploits the differing response of two detectors to muonic and electromagnetic particles. Exploitation of this difference may be expressed in a matrix formalism whose application to simulated proton and iron showers is presented here.

  14. Experimental study of muonic x-ray transitions in mercury isotopes. [Fermi distribution, B(E2)

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, A.A.; Miller, J.P.; Powers, R.J.; Zehnder, A.; Rushton, A.M.; Welsh, R.E.; Kunselman, A.R.; Roberson, P.; Walter, H.K.

    1978-01-01

    Muonic x-ray spectra were measured for /sup 198/ /sup 199/ /sup 200/ /sup 201/ /sup 202/ and /sup 204/Hg. These data were interpreted in terms of a two parameter Fermi distribution for the charge density. The spectroscopic quadrupole moments (Q/sub s/) of some of the 2/sup +/ nuclear states were inferred. For /sup 199/Hg the spectroscopic quadrupole moments of the first two excited states and the B(E2)'s connecting these states to the ground state were determined. For /sup 201/Hg the ground state quadrupole moment was obtained as well as several other E2 moments but the interpretation of the data was hampered by a possible incomplete knowledge of the nuclear scheme of this nucleus. The muonic isotope shifts were measured and interpreted in terms of deltaR/sub k/ and are compared to electronic x-ray and optical isotope shift measurements. 41 references

  15. The quadrupole moment and strong interaction parameters from muonic and pionic X-ray studies of 237Np

    International Nuclear Information System (INIS)

    Laat, C.T.A.M. de; Taal, A.; Duinker, W.; Konijn, J.; Petitjean, C.; Reist, H.W.; Mueller, W.; Commission of the European Communities, Geel

    1987-01-01

    The X-ray spectrum of muonic and pionic 237 Np has been investigated with muons and pions stopped in a NpO 2 target. The nuclear spectroscopic quadrupole moment was determined to be Q=3.886±0.006 b from the splittings of the muonic 5g→4f hyperfine complexes. The B(E2)↓-values for the first and second excited states were evaluated as 3.17±0.08 and 2.77±0.10 e 2 b 2 , respectively. A comparison between the muonic and pionic 5g→4f hyperfine complexes yields the strong interaction parameter for the pionic 4f state. For the first time a change of sign as function of Z for the strong interaction quadrupole shift ε 2 (4f) has been observed. The standard optical model predictions agree reasonably well with the measured strong interaction monopole shift, ε 0 (4f), and width, Γ 0 (4f), while they disagree with the experimental value for ε 2 . A stronger s-wave repulsion in the optical potential could explain this effect. (orig.)

  16. Vii. New Kr IV - VII Oscillator Strengths and an Improved Spectral Analysis of the Hot, Hydrogen-deficient Do-type White Dwarf RE 0503-289

    Science.gov (United States)

    Rauch, T.; Quinet, P.; Hoyer, D.; Werner, K.; Richter, P.; Kruk, J. W.; Demleitner, M.

    2016-01-01

    For the spectral analysis of high-resolution and high signal-to-noise (SN) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Krivvii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTEmodel-atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Krivvii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high SN ultraviolet (UV)observations of the hot white dwarf RE 0503.

  17. Dark hydrogen fermentations

    NARCIS (Netherlands)

    Vrije, de G.J.; Claassen, P.A.M.

    2003-01-01

    The production of hydrogen is a ubiquitous, natural phenomenon under anoxic or anaerobic conditions. A wide variety of bacteria, in swamps, sewage, hot springs, the rumen of cattle etc. is able to convert organic matter to hydrogen, CO2 and metabolites like acetic acid, lactate, ethanol and alanine.

  18. Observation of electric quadrupole X-ray transitions in muonic thallium, lead and bismuth

    CERN Document Server

    Schneuwly, H; Engfer, R; Jahnke, U; Kankeleit, E; Lindenberger, K H; Pearce, R M; Petitjean, C; Schellenberg, L; Schröder, W U; Walter, H K; Zehnder, A

    1972-01-01

    Electric quadrupole X-ray transitions (5g to 3d, 4f to 2p, and 3d to 1s) have been observed in muonic Tl, Pb and Bi. From the 3 to 1 transitions, energy splittings of the n=3 levels were deduced. From a comparison of the relative intensities of E1 and E2 transitions the population ratios 5g/5f, 4f/4d, and 3d/3p were deduced. These ratios are well reproduced by a cascade calculation assuming a statistical initial population at n=20, including K, L and M shell conversion. In the case of /sup 205/Tl discrepancies between the experimental and the calculated 3d-1s/3p-is intensity ratio can be explained by nuclear excitation. From the 3p/sub 3/2/ to 1s/sub 1/2/ intensity in /sup 209 /Bi one can deduce the ratio of the radiationless to the X-ray transition width and give limits for prompt neutron emission from the 3d level. (23 refs).

  19. On measurement of cross sections for scattering of pμ - and d μ -atoms in hydrogen and deuterium

    International Nuclear Information System (INIS)

    Bystritskij, V.M.

    1993-01-01

    The paper is a brief review of all experiments on measurement of cross sections for scattering of pμ - atoms in hydrogen and dμ - atoms in hydrogen and deuterium. The experimental results are analysed and compared both with one another and with calculated results. A program for further investigation of scattering of muonic atoms of hydrogen isotopes is proposed in order to clarify the nature of discrepancies between some experimental results and to get more precise information about the above processes. (author.). 24 refs.; 4 figs.; 3 tabs

  20. HOT 2012

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen......Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...

  1. HOT 2014

    DEFF Research Database (Denmark)

    Lund, Henriette

    Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...

  2. HOT 2011

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet....

  3. Search for the radiative capture reaction d + d -> sup 4 He + gamma from the dd mu muonic molecule state

    CERN Document Server

    Bogdanova, L N; Eijk, C W E

    2002-01-01

    A search for the muon catalyzed fusion (MCF) reaction d + d -> sup 4 He + gamma in the dd mu muonic molecule was performed using the experimental MCF installation TRITON and NaI(Tl) detectors for gamma quanta. The high-pressure target filled with deuterium was exposed to the negative muon beam of the JINR phasotron to detect gamma quanta with energy 23.8 MeV. The first experimental estimation for the yield of the radiative deuteron capture from the dd mu state J = 1 was obtained at the level eta subgamma <= 2 x 10 sup - sup 5 per one fusion

  4. Calculation of the ground-state energy and average distance between particles for the nonsymmetric muonic 3He atom

    International Nuclear Information System (INIS)

    Eskandari, M.R.; Rezaie, B.

    2005-01-01

    A calculation of the ground-state energy and average distance between particles in the nonsymmetric muonic 3 He atom is given. We have used a wave function with one free parameter, which satisfies boundary conditions such as the behavior of the wave function when two particles are close to each other or far away. In the proposed wave function, the electron-muon correlation function is also considered. It has a correct behavior for r 12 tending to zero and infinity. The calculated values for the energy and expectation values of r 2n are compared with the multibox variational approach and the correlation function hyperspherical harmonic method. In addition, to show the importance and accuracy of approach used, the method is applied to evaluate the ground-state energy and average distance between the particles of nonsymmetric muonic 4 He atom. Our obtained results are very close to the values calculated by the mentioned methods and giving strong indications that the proposed wave functions, in addition to being very simple, provide relatively accurate values for the energy and expectation values of r 2n , emphasizing the importance of the local properties of the wave function

  5. TWO REGIMES OF INTERACTION OF A HOT JUPITER’S ESCAPING ATMOSPHERE WITH THE STELLAR WIND AND GENERATION OF ENERGIZED ATOMIC HYDROGEN CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Shaikhislamov, I. F.; Prokopov, P. A.; Berezutsky, A. G.; Zakharov, Yu. P.; Posukh, V. G. [Institute of Laser Physics SB RAS, Novosibirsk (Russian Federation); Khodachenko, M. L.; Lammer, H.; Kislyakova, K. G.; Fossati, L. [Space Research Institute, Austrian Acad. Sci., Graz (Austria); Johnstone, C. P., E-mail: maxim.khodachenko@oeaw.ac.at [Department of Astrophysics, University of Vienna, Vienna (Austria)

    2016-12-01

    The interaction of escaping the upper atmosphere of a hydrogen-rich non-magnetized analog of HD 209458b with a stellar wind (SW) of its host G-type star at different orbital distances is simulated with a 2D axisymmetric multi-fluid hydrodynamic (HD) model. A realistic Sun-like spectrum of X-ray and ultraviolet radiation, which ionizes and heats the planetary atmosphere, together with hydrogen photochemistry, as well as stellar-planetary tidal interaction are taken into account to generate self-consistently an atmospheric HD outflow. Two different regimes of the planetary and SW interaction have been modeled. These are: (1) the “ captured by the star ” regime, when the tidal force and pressure gradient drive the planetary material beyond the Roche lobe toward the star, and (2) the “ blown by the wind ” regime, when sufficiently strong SW confines the escaping planetary atmosphere and channels it into the tail. The model simulates in detail the HD interaction between the planetary atoms, protons and the SW, as well as the production of energetic neutral atoms (ENAs) around the planet due to charge exchange between planetary atoms and stellar protons. The revealed location and shape of the ENA cloud, either as a paraboloid shell between the ionopause and bowshock (for the “ blown by the wind ” regime), or a turbulent layer at the contact boundary between the planetary stream and SW (for the “ captured by the star ” regime) are of importance for the interpretation of Ly α absorption features in exoplanetary transit spectra and characterization of the plasma environments.

  6. TWO REGIMES OF INTERACTION OF A HOT JUPITER’S ESCAPING ATMOSPHERE WITH THE STELLAR WIND AND GENERATION OF ENERGIZED ATOMIC HYDROGEN CORONA

    International Nuclear Information System (INIS)

    Shaikhislamov, I. F.; Prokopov, P. A.; Berezutsky, A. G.; Zakharov, Yu. P.; Posukh, V. G.; Khodachenko, M. L.; Lammer, H.; Kislyakova, K. G.; Fossati, L.; Johnstone, C. P.

    2016-01-01

    The interaction of escaping the upper atmosphere of a hydrogen-rich non-magnetized analog of HD 209458b with a stellar wind (SW) of its host G-type star at different orbital distances is simulated with a 2D axisymmetric multi-fluid hydrodynamic (HD) model. A realistic Sun-like spectrum of X-ray and ultraviolet radiation, which ionizes and heats the planetary atmosphere, together with hydrogen photochemistry, as well as stellar-planetary tidal interaction are taken into account to generate self-consistently an atmospheric HD outflow. Two different regimes of the planetary and SW interaction have been modeled. These are: (1) the “ captured by the star ” regime, when the tidal force and pressure gradient drive the planetary material beyond the Roche lobe toward the star, and (2) the “ blown by the wind ” regime, when sufficiently strong SW confines the escaping planetary atmosphere and channels it into the tail. The model simulates in detail the HD interaction between the planetary atoms, protons and the SW, as well as the production of energetic neutral atoms (ENAs) around the planet due to charge exchange between planetary atoms and stellar protons. The revealed location and shape of the ENA cloud, either as a paraboloid shell between the ionopause and bowshock (for the “ blown by the wind ” regime), or a turbulent layer at the contact boundary between the planetary stream and SW (for the “ captured by the star ” regime) are of importance for the interpretation of Ly α absorption features in exoplanetary transit spectra and characterization of the plasma environments.

  7. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn{sub 2}O{sub 3} sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.F.; Liu, B.S., E-mail: bingsiliu@tju.edu.cn; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-09-15

    Graphical abstract: - Highlights: • Mn{sub 2}O{sub 3}/KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn{sub 2}O{sub 3}/KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn{sub 2}O{sub 3} sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn{sub 2}O{sub 3} sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H{sub 2}S. The fresh and used sorbents were characterized by means of N{sub 2}-adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H{sub 2} temperature- programmed reduction (H{sub 2}-TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn{sub 2}O{sub 3}/diatomite, all mesoporous silica supported Mn{sub 2}O{sub 3} sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn{sub 2}O{sub 3}/MCM-41 and Mn{sub 2}O{sub 3}/HMS sorbent, the Mn{sub 2}O{sub 3}/KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn{sub 2}O{sub 3}/KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn{sub 2}O{sub 3}/KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  8. HOT 2010

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....

  9. HOT 2013

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....

  10. Production and muonic decay of the intermediate vector boson Z0 in the UA1-experiment

    International Nuclear Information System (INIS)

    Leuchs, R.

    1988-01-01

    In this thesis the production of the z 0 in proton-antiproton collisions and the subsequent decay of the Z - 0 into two muons is experimentally studied. I was first responsible for the faultless readout of the muon detector. In the analysis I have first selected the Z 0 data of the runs of 1984 and 1985, as well as determined the efficiency of this selection. Furthermore I have collaborated in the establishment of the p t μ > 15 GeV/c selection. In the following the Z 0 sample was examined on completeness and the background calculated again. At c.m. energies of √S = 546 GeV and √S = 630 GeV in the whole 21 Z 0 events were identified by their muonic decay. The analysis of the data yielded the following essential results: M Z = 90.7 -4.8 +5.2 (stat.)±3.2(syst.) GeV/c 2 . From the asymmetry of the muon angular distribution we calculate the electroweak mixing angle to sin 2θ W = 0.24 -0.04 +0.05 . The mixing can be better determined from the ratio of the W ± and Z 0 masses. In the muon channel we obtain sin 2 θ W = 0.187±0.148(stat.)±0.033(syst.). If the weak mixing angle is given from the mass ratio the ρ parameter can be calculated. In the muon channel we obtain ρ = 1.05±0.16(stat.)±0.05(syst.). The measured cross sections of (σ.B) μ 546 GeV = 98.4±49.8(stat.)±19.9(syst) and (σ.B) μ 630 Gev = 65.9±17.2(stat.)±10.9(syst) are compatible with the prediction of the Drell-Yan production mechanism. From the ratio of the cross sections the number of the light neutrino generations N ν can be limited to above. With 90% confidence N ν 0 further heavy vector bosons below a mass of 173 GeV/c 2 are excluded. (orig./HSI) [de

  11. Sub-bandgap optical absorption spectroscopy of hydrogenated microcrystalline silicon thin films prepared using hot-wire CVD (Cat-CVD) process

    International Nuclear Information System (INIS)

    Goktas, O.; Isik, N.; Okur, S.; Gunes, M.; Carius, R.; Klomfass, J.; Finger, F.

    2006-01-01

    Hydrogenated microcrystalline silicon (μc-Si:H) thin films with different silane concentration (SC) have been prepared using the HW-CVD technique. Dual beam photoconductivity (DBP), photothermal deflection spectroscopy (PDS), and transmission measurements have been used to investigate the optical properties of the μc-Si:H films. Two different sub-bandgap absorption, α(hν), methods have been applied and analyzed to obtain a better insight into the electronic states involved. A good agreement has been obtained in the absorption spectrum obtained from the PDS and DBP measurements at energies above the bandgap. Differences between PDS and DBP spectra exist below the bandgap energy where DBP spectra always give lower α(hν) values and show a dependence on the SC. For some films, differences exist in the α(hν) spectra when the DBP measurements are carried out through the film and substrate side. In addition, for some films, there remains fringe pattern left on the spectrum after the calculation of the fringe-free absorption spectrum, which indicates structural inhomogeneities present throughout the film

  12. New Measurement of the 1 S -3 S Transition Frequency of Hydrogen: Contribution to the Proton Charge Radius Puzzle

    Science.gov (United States)

    Fleurbaey, Hélène; Galtier, Sandrine; Thomas, Simon; Bonnaud, Marie; Julien, Lucile; Biraben, François; Nez, François; Abgrall, Michel; Guéna, Jocelyne

    2018-05-01

    We present a new measurement of the 1 S -3 S two-photon transition frequency of hydrogen, realized with a continuous-wave excitation laser at 205 nm on a room-temperature atomic beam, with a relative uncertainty of 9 ×10-13. The proton charge radius deduced from this measurement, rp=0.877 (13 ) fm , is in very good agreement with the current CODATA-recommended value. This result contributes to the ongoing search to solve the proton charge radius puzzle, which arose from a discrepancy between the CODATA value and a more precise determination of rp from muonic hydrogen spectroscopy.

  13. The Rydberg constant and proton size from atomic hydrogen

    Science.gov (United States)

    Beyer, Axel; Maisenbacher, Lothar; Matveev, Arthur; Pohl, Randolf; Khabarova, Ksenia; Grinin, Alexey; Lamour, Tobias; Yost, Dylan C.; Hänsch, Theodor W.; Kolachevsky, Nikolai; Udem, Thomas

    2017-10-01

    At the core of the “proton radius puzzle” is a four-standard deviation discrepancy between the proton root-mean-square charge radii (rp) determined from the regular hydrogen (H) and the muonic hydrogen (µp) atoms. Using a cryogenic beam of H atoms, we measured the 2S-4P transition frequency in H, yielding the values of the Rydberg constant R∞ = 10973731.568076(96) per meterand rp = 0.8335(95) femtometer. Our rp value is 3.3 combined standard deviations smaller than the previous H world data, but in good agreement with the µp value. We motivate an asymmetric fit function, which eliminates line shifts from quantum interference of neighboring atomic resonances.

  14. HOT 2017

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    HOT er en kvalitativ undersøgelse, der hvert år diskuterer og undersøger en lille udvalgt skare af danskkyndige fagpersoners bud på, hvad de er optagede af på literacyområdet her og nu – altså hvilke emner, de vil vurdere som aktuelle at forholde sig til i deres nuværende praksis.......HOT er en kvalitativ undersøgelse, der hvert år diskuterer og undersøger en lille udvalgt skare af danskkyndige fagpersoners bud på, hvad de er optagede af på literacyområdet her og nu – altså hvilke emner, de vil vurdere som aktuelle at forholde sig til i deres nuværende praksis....

  15. Hot particles

    International Nuclear Information System (INIS)

    Merwin, S.E.; Moeller, M.P.

    1989-01-01

    Nuclear Regulatory Commission (NRC) licensees are required to assess the dose to skin from a hot particle contamination event at a depth of skin of7mg/cm 2 over an area of 1 cm 2 and compare the value to the current dose limit for the skin. Although the resulting number is interesting from a comparative standpoint and can be used to predict local skin reactions, comparison of the number to existing limits based on uniform exposures is inappropriate. Most incidents that can be classified as overexposures based on this interpretation of dose actually have no effect on the health of the worker. As a result, resources are expended to reduce the likelihood that an overexposure event will occur when they could be directed toward eliminating the cause of the problem or enhancing existing programs such as contamination control. Furthermore, from a risk standpoint, this practice is not ALARA because some workers receive whole body doses in order to minimize the occurrence of hot particle skin contaminations. In this paper the authors suggest an alternative approach to controlling hot particle exposures

  16. Hydrogen converters

    International Nuclear Information System (INIS)

    Mondino, Angel V.

    2003-01-01

    The National Atomic Energy Commission of Argentina developed a process of 99 Mo production from fission, based on irradiation of uranium aluminide targets with thermal neutrons in the RA-3 reactor of the Ezeiza Atomic Centre. These targets are afterwards dissolved in an alkaline solution, with the consequent liberation of hydrogen as the main gaseous residue. This work deals with the use of a first model of metallic converter and a later prototype of glass converter at laboratory scale, adjusted to the requirements and conditions of the specific redox process. Oxidized copper wires were used, which were reduced to elementary copper at 400 C degrees and then regenerated by oxidation with hot air. Details of the bed structure and the operation conditions are also provided. The equipment required for the assembling in cells is minimal and, taking into account the operation final temperature and the purge with nitrogen, the procedure is totally safe. Finally, the results are extrapolated for the design of a converter to be used in a hot cell. (author)

  17. Hydrogen energy

    International Nuclear Information System (INIS)

    2005-03-01

    This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

  18. Search of neutrino oscillations by ντ appearance with τ decay in the muonic channel in OPERA experiment

    International Nuclear Information System (INIS)

    Tran, N.T.

    2010-10-01

    Neutrino oscillations, based on a change of flavor state of a neutrino during its propagation, can explain the deficits observed on solar and atmospheric neutrinos and provide some interesting indications for physics beyond the Standard Model by studying the mixing angles and the hierarchy of neutrino mass. The OPERA experiment is the first experiment designed to observe the appearance of a ν τ by the oscillation of the ν μ to ν τ in the CNGS beam from CERN to Gran Sasso. OPERA is a hybrid detector combining both the technique of an on time electronic detection and the technique of emulsion cloud chamber (ECC). The ECC detector is a passive detector (target) of 150.000 bricks, each one consisting of sheets of lead, used as target, alternating with nuclear photographic emulsions whose accuracy of track reconstruction is about one micron. The detector also includes two spectrometers with magnetized iron plates 5 cm thick alternating with RPC (resistive plate chamber) associated with six sets of drift tubes for the measurement of the charge and momentum of the muon. It includes also a Veto plane used for rejection of particles coming outside the target. This detector simultaneously allows a high spatial resolution and a large target mass which are two very conditions necessary for collecting charged current neutrino interactions from oscillated ν τ and observing the decay topology of τ. This thesis presents a study on tau decay in the muonic channel. It has contributed to 1) the development of an algorithm for the selection of the neutrino interactions in the target, 2) the studies on the muon identification in electronic detectors and the connection of its trace with those reconstructed in the emulsions, which represent a fundamental point both for the tau signal identification as the rejection of charmed background, 3) the development of a neural network to discriminate the signal from the charmed background regardless of the muon identification in

  19. Inclusive Production of the $\\omega$ and $\\eta$ Mesons in Z Decays, and the Muonic Branching Ratio of the $\\omega$

    CERN Document Server

    Heister, A.; Barate, R.; De Bonis, I.; Decamp, D.; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Boix, G.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Azzurri, P.; Buchmuller, O.; Cattaneo, M.; Cerutti, F.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Greening, T.C.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schneider, O.; Sguazzoni, G.; Tejessy, W.; Teubert, F.; Valassi, A.; Videau, I.; Ward, J.; Badaud, F.; Falvard, A.; Gay, P.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J-C.; Pallin, D.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Waananen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J.-C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Spagnolo, P.; Halley, A.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Marinelli, N.; Sedgbeer, J.K.; Thompson, J.C.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Sander, H.G.; Wachsmuth, H.; Zeitnitz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Settles, R.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Jacholkowska, A.; Lefrancois, J.; Veillet, J.J.; Yuan, C.; Bagliesi, Giuseppe; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; von Wimmersperg-Toeller, J.H.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Konstantinidis, N.; Litke, A.M.; Taylor, G.; Beddall, A.; Booth, C.N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Ngac, A.; Prange, G.; Sieler, U.; Giannini, G.; Rothberg, J.; Armstrong, S.R.; Berkelman, Karl; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

    2002-01-01

    The inclusive production of the omega(782) vector meson in hadronic Z decays is measured and compared to model predictions. The analysis is based on 4 million hadronic Z decays recorded by the ALEPH detector between 1991 and 1995. The production rate for x_p = p_meson/p_beam > 0.05 is measured in the omega -> pi^+ pi^- pi^0 decay mode and found to be 0.585 +- 0.019_stat +- 0.033_sys per event. Inclusive eta meson production is also measured in the same decay channel for x_p > 0.10, obtaining 0.355 +- 0.011_stat +- 0.024_sys per event. The branching ratio for omega -> mu^+ mu^- is investigated. A total of 18.1 +- 5.9 events are observed, from which the muonic branching ratio is measured for the first time to be BR(omega -> mu^+ mu^-) = (9.0 +- 2.9_stat +- 1.1_sys)*10^-5.

  20. Calculations of the Auger deexcitation rate of dtμ within the muonic quasimolecule (dtμ)dee

    Science.gov (United States)

    Armour, E. A. G.; Lewis, D. M.; Hara, S.

    1992-12-01

    A key process in muon-catalyzed fusion is the deexcitation of dtμ within the resonant muonic quasimolecule (dtμ)dee, by emission of an Auger electron. The dtμ in the quasimolecule is initially in a weakly bound excited state with J=1 and v=1. Calculations are carried out of the rate of the dominant transition to the state with J=0 and v=1. Use is made of the dipole matrix element obtained for this transition by Scrinzi and Szalewicz [Phys. Rev. A 39, 2855 (1989)]. Full account is taken of the molecular nature of the quasimolecule. The continuum electronic wave functions for the Auger electron for all four contributing symmetries, i.e., Σ+g, Σ+u, Πu, and Πg, are first obtained by a two-center Coulomb calculation and a static-exchange calculation, extended to include dipole polarization. Comparison is then made with the results of a calculation in which the Σ+μ and Πu wave functions are obtained as in a previous paper by Armour and Lewis [J. Phys. B 23, L25 (1990)] and the Σ+g and Πg wave functions are obtained by the Kohn method. There are significant differences between the contributions from the individual symmetries, but the overall values for the deexcitation rate are all of the same order of magnitude as the results of earlier calculations.

  1. Calculations of the Auger deexcitation rate of the dtμ within the muonic quasi-molecule, [(dtμ)dee

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Lewis, D.M.; Hara, S.

    1993-01-01

    A key process in muon catalysed fusion is the deexcitation of the dtμ within the resonant muonic quasi-molecule [(dtμ)dee], by emission of an Auger electron. The dtμ in the quasi-molecule is initially in a weakly bound excited state with J = 1 and v = 1. In this paper, calculations taking full account of the molecular nature of the quasi-molecule are carried out of the rate of the dominant deexcitation to the state with J = 0 and v = 1. (orig.)

  2. Experimental study of nuclear models. I. Decay schemes and nuclear reactions. II. Muonic x-ray studies. Progress report, October 1, 1974--September 30, 1975

    International Nuclear Information System (INIS)

    Sheline, R.K.

    1975-01-01

    Progress on the research on our AT-(40-1)-2434 Contract is summarized for the twelve month contract year beginning October 1, 1974, and ending September 30, 1975. The main emphasis of our research continues to be an experimental study of nuclear models. Some change of emphasis is occurring. In the past, the emphasis has been overwhelmingly nuclear reaction spectroscopy and comparison with theoretical models. This year an increasing percentage of the emphasis (perhaps 25 percent) is on the study of nuclear structure from the view point of muonic x-ray spectroscopy. A list of publications is included. (U.S.)

  3. The charge-distribution differences of 209Bi, 208207206204Pb and 205203Tl investigated by elastic electron scattering and muonic X-ray data

    International Nuclear Information System (INIS)

    Euteneuer, H.; Friedrich, J.; Voegler, N.

    1978-01-01

    Elastic electron scattering cross sections and cross-section ratios have been measured for the stable Bi, Pb and Ti isotopes. The data are analysed with the Fourier-Bessel method and the charge-distribution differences of the isotonic and isotopic pairs are presented as well as the Fourier-Bessel coefficients of the seven single nuclei. To improve the accuracy of the results, muonic X-ray data are incorporated into the analysis. The measured Δrho(r) are compared with the simple shell model, where the stretching due to the additional nucleons is taken into account, and with more sophisticated HF calculations. (Auth.)

  4. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  5. Hydrogen system (hydrogen fuels feasibility)

    International Nuclear Information System (INIS)

    Guarna, S.

    1991-07-01

    This feasibility study on the production and use of hydrogen fuels for industry and domestic purposes includes the following aspects: physical and chemical properties of hydrogen; production methods steam reforming of natural gas, hydrolysis of water; liquid and gaseous hydrogen transportation and storage (hydrogen-hydride technology); environmental impacts, safety and economics of hydrogen fuel cells for power generation and hydrogen automotive fuels; relevant international research programs

  6. Solar 'hot spots' are still hot

    Science.gov (United States)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  7. Solar hot spots are still hot

    International Nuclear Information System (INIS)

    Bai, T.

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

  8. Hail hydrogen

    International Nuclear Information System (INIS)

    Hairston, D.

    1996-01-01

    After years of being scorned and maligned, hydrogen is finding favor in environmental and process applications. There is enormous demand for the industrial gas from petroleum refiners, who need in creasing amounts of hydrogen to remove sulfur and other contaminants from crude oil. In pulp and paper mills, hydrogen is turning up as hydrogen peroxide, displacing bleaching agents based on chlorine. Now, new technologies for making hydrogen have the industry abuzz. With better capabilities of being generated onsite at higher purity levels, recycled and reused, hydrogen is being prepped for a range of applications, from waste reduction to purification of Nylon 6 and hydrogenation of specialty chemicals. The paper discusses the strong market demand for hydrogen, easier routes being developed for hydrogen production, and the use of hydrogen in the future

  9. Models of hot stellar systems

    International Nuclear Information System (INIS)

    Van Albada, T.S.

    1986-01-01

    Elliptical galaxies consist almost entirely of stars. Sites of recent star formation are rare, and most stars are believed to be several billion years old, perhaps as old as the Universe itself (--10/sup 10/ yrs). Stellar motions in ellipticals show a modest amount of circulation about the center of the system, but most support against the force of gravity is provided by random motions; for this reason ellipticals are called 'hot' stellar systems. Spiral galaxies usually also contain an appreciable amount of gas (--10%, mainly atomic hydrogen) and new stars are continually being formed out of this gas, especially in the spiral arms. In contrast to ellipticals, support against gravity in spiral galaxies comes almost entirely from rotation; random motions of the stars with respect to rotation are small. Consequently, spiral galaxies are called 'cold' stellar systems. Other than in hot systems, in cold systems the collective response of stars to variations in the force field is an essential part of the dynamics. The present overview is limited to mathematical models of hot systems. Computational methods are also discussed

  10. Hot tub folliculitis

    Science.gov (United States)

    ... survives in hot tubs, especially tubs made of wood. Symptoms The first symptom of hot tub folliculitis ... may help prevent the problem. Images Hair follicle anatomy References D'Agata E. Pseudomonas aeruginosa and other ...

  11. Hydrogen detector

    International Nuclear Information System (INIS)

    Kumagaya, Hiromichi; Yoshida, Kazuo; Sanada, Kazuo; Chigira, Sadao.

    1994-01-01

    The present invention concerns a hydrogen detector for detecting water-sodium reaction. The hydrogen detector comprises a sensor portion having coiled optical fibers and detects hydrogen on the basis of the increase of light transmission loss upon hydrogen absorption. In the hydrogen detector, optical fibers are wound around and welded to the outer circumference of a quartz rod, as well as the thickness of the clad layer of the optical fiber is reduced by etching. With such procedures, size of the hydrogen detecting sensor portion can be decreased easily. Further, since it can be used at high temperature, diffusion rate is improved to shorten the detection time. (N.H.)

  12. Modelling Hot Air Balloons.

    Science.gov (United States)

    Brimicombe, M. W.

    1991-01-01

    A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

  13. Precision spectroscopy of the 2S-4P transition in atomic hydrogen

    Science.gov (United States)

    Maisenbacher, Lothar; Beyer, Axel; Matveev, Arthur; Grinin, Alexey; Pohl, Randolf; Khabarova, Ksenia; Kolachevsky, Nikolai; Hänsch, Theodor W.; Udem, Thomas

    2017-04-01

    Precision measurements of atomic hydrogen have long been successfully used to extract fundamental constants and to test bound-state QED. However, both these applications are limited by measurements of hydrogen lines other than the very precisely known 1S-2S transition. Moreover, the proton r.m.s.charge radius rp extracted from electronic hydrogen measurements currently disagrees by 4 σ with the much more precise value extracted from muonic hydrogen spectroscopy. We have measured the 2S-4P transition in atomic hydrogen using a cryogenic beam of hydrogen atoms optically excited to the initial 2S state. The first order Doppler shift of the one-photon 2S-4P transition is suppressed by actively stabilized counter-propagating laser beams and time-of-flight resolved detection. Quantum interference between excitation paths can lead to significant line distortions in our system. We use an experimentally verified, simple line shape model to take these distortions into account. With this, we can extract a new value for rp and the Rydberg constant R∞ with comparable accuracy as the combined previous H world data.

  14. Hydrogen highway

    International Nuclear Information System (INIS)

    Anon

    2008-01-01

    The USA Administration would like to consider the US power generating industry as a basis ensuring both the full-scale production of hydrogen and the widespread use of the hydrogen related technological processes into the economy [ru

  15. A new method to induce transitions in muonic atoms using a high-power tunable dye laser coupled to a stopping muon beam

    CERN Document Server

    Bertin, A; Duclos, J; Gastaldi, Ugo; Gorini, G; Neri, G; Picard, J; Pitzurra, O; Placci, A; Polacco, E; Stefanini, G; Torelli, G; Vitale, A; Zavattini, E

    1974-01-01

    An apparatus is described in which a ruby-pumped dye laser is used to induce transitions from the 2S to the 2P levels of the muonic ion ( mu He)/sup +/. The dye laser supplies infra-red radiation pulses in the wavelengths (8040-8180) AA, at typical repetition rates of 1 pulse every 4 s, with an energy release per pulse of 300 mJ for 1.2 J pumping energy. A special synchronization procedure is followed to trigger the laser in close coupling with the incoming muon beam which is stopped in a helium target at pressures between 40 and 50 atm. The other performances of the device are fully discussed with reference both to the laser facility and to the special high-pressure helium target. (23 refs).

  16. Lamb shifts and fine-structure splittings for the muonic ions μ--Li, μ--Be, and μ--B: A proposed experiment

    International Nuclear Information System (INIS)

    Drake, G.W.F.; Byer, L.L.

    1985-01-01

    Detailed calculations are presented for the energy splittings of the states 2s/sub 1/2/-2p/sub 1/2/ and 2s/sub 1/2/-2p/sub 3/2/ for the muonic ions μ - -Li, μ - -Be, and μ - -B obtained by numerical integration of the Dirac equation. It is shown that there is severe cancellation between the vacuum polarization and finite nuclear size contributions to the energy differences, leading to transition frequencies which lie in the visible region of the spectrum. As a consequence of the cancellation, a measurement of the transition frequency would provide a sensitive probe of nuclear size and structure. The system μ - - 7 Li appears to offer particularly good possibilities for performing such an experiment

  17. Hydrogen-water isotopic exchange process

    International Nuclear Information System (INIS)

    Cheung, H.

    1983-01-01

    Deuterium is concentrated in a hydrogen-water isotopic exchange process enhanced by the use of catalyst materials in cold and hot tower contacting zones. Water is employed in a closed liquid recirculation loop that includes the cold tower, in which deuterium is concentrated in the water, and the upper portion of the hot tower in which said deuterium is concentrated in the hydrogen stream. Feed water is fed to the lower portion of said hot tower for contact with the circulating hydrogen stream. The feed water does not contact the water in the closed loop. Catalyst employed in the cold tower and the upper portion of the hot tower, preferably higher quality material, is isolated from impurities in the feed water that contacts only the catalyst, preferably of lower quality, in the lower portion of the hot zone. The closed loop water passes from the cold zone to the dehumidification zone, and a portion of said water leaving the upper portion of the hot tower can be passed to the humidification zone and thereafter recycled to said closed loop. Deuterium concentration is enhanced in said catalytic hydrogen-water system while undue retarding of catalyst activity is avoided

  18. 2S-4S spectroscopy in hydrogen atom: The new value for the Rydberg constant and the proton charge radius

    Science.gov (United States)

    Kolachevsky, N.; Beyer, A.; Maisenbacher, L.; Matveev, A.; Pohl, R.; Khabarova, K.; Grinin, A.; Lamour, T.; Yost, D. C.; Haensch, T. W.; Udem, Th.

    2018-02-01

    The core of the "proton radius puzzle" is the discrepancy of four standard deviations between the proton root mean square charge radii (rp) determined from regular hydrogen (H), and the muonic hydrogen atom (μp). We have measured the 2S-4P transition frequency in H, utilizing a cryogenic beam of H and directly demonstrate that quantum interference of neighboring atomic resonances can lead to line shifts much larger than the proton radius discrepancy. Using an asymmetric fit function we obtain rp = 0.8335(95) fm and the Rydberg constant R∞ = 10 973 731.568 076 (96) m-1. The new value for rp is 3.3 combined standard deviations smaller than the latest CODATA value, but in good agreement with the value from μp.

  19. Hydrogen economy

    Energy Technology Data Exchange (ETDEWEB)

    Pahwa, P.K.; Pahwa, Gulshan Kumar

    2013-10-01

    In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Hydrogen has been proposed as the perfect fuel for this future energy system. The availability of a reliable and cost-effective supply, safe and efficient storage, and convenient end use of hydrogen will be essential for a transition to a hydrogen economy. Research is being conducted throughout the world for the development of safe, cost-effective hydrogen production, storage, and end-use technologies that support and foster this transition. This book discusses hydrogen economy vis-a-vis sustainable development. It examines the link between development and energy, prospects of sustainable development, significance of hydrogen energy economy, and provides an authoritative and up-to-date scientific account of hydrogen generation, storage, transportation, and safety.

  20. Mecanical Properties Degradation by Hydrogen Embrittlement

    International Nuclear Information System (INIS)

    Bertolino, G; Meyer, G; Perez Ipina J

    2001-01-01

    The presence of hydrogen-rich media during nuclear plant operation motivates the study of the zirconium alloys degradation of their mechanical properties influenced by hydrogen content and temperature.In this work we study samples with a microstructure of equiaxial grains resulted from hot-rolled, and with different homogeneous hydrogen content obtained by electrochemical charge and a thermal treatment.The influence of hydrogen content and temperature was analyzed from the results of fracture-mechanical tests on CT (compact test) probes using the J-criteria

  1. Muonium and muonic radicals

    International Nuclear Information System (INIS)

    Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Geeson, D.; Symons, M.C.R.

    1985-01-01

    An energetic positive muon which is injected in a liquid sample of substrate molecules (S) creates an ionization track consisting of substrate cations (S + ) and electrons. Near the end of this track the muon may combine with an electron to form muonium (Mu) which is observable in inert liquids, but which reacts by addition to form a radical. Alternatively, the electron can add to S to form S - , which then combines with the muon to form the radical. Furthermore, instead of ending up in Mu or in a radical the muon may stay in a diamagnetic environment as a solvated muon, or as a muon substituting a proton in a molecule. Of interest in these schemes are the mechanisms and rates of formation of muonated radicals and in particular the rate constants for their reactions to products. Investigations are based on the observation of Mu and the radical by means of the μSR technique in transverse magnetic fields. (Auth.)

  2. Hydrogen safety

    International Nuclear Information System (INIS)

    Frazier, W.R.

    1991-01-01

    The NASA experience with hydrogen began in the 1950s when the National Advisory Committee on Aeronautics (NACA) research on rocket fuels was inherited by the newly formed National Aeronautics and Space Administration (NASA). Initial emphasis on the use of hydrogen as a fuel for high-altitude probes, satellites, and aircraft limited the available data on hydrogen hazards to small quantities of hydrogen. NASA began to use hydrogen as the principal liquid propellant for launch vehicles and quickly determined the need for hydrogen safety documentation to support design and operational requirements. The resulting NASA approach to hydrogen safety requires a joint effort by design and safety engineering to address hydrogen hazards and develop procedures for safe operation of equipment and facilities. NASA also determined the need for rigorous training and certification programs for personnel involved with hydrogen use. NASA's current use of hydrogen is mainly for large heavy-lift vehicle propulsion, which necessitates storage of large quantities for fueling space shots and for testing. Future use will involve new applications such as thermal imaging

  3. Measurements of μ capture rates in liquid hydrogen by the lifetime method

    International Nuclear Information System (INIS)

    Martino, Jacques.

    1982-04-01

    The μ capture reaction is a weak interaction. It can be observed as a result of the formation of muonic atoms for which the overlopping of the wave functions of the muon and nucleus is a maximum in the 1s state. The production of this (μp) bound state leads to a capture rate in relatively favorable competition with the disintegration rate. The capture rate for a pulsed muon beam (from the Saclay linear accelerator) was measured in liquid hydrogen by the lifetime method. The method and experimental equipment used for the lifetime measurements are described together with the different sources of systematic error and the results obtained. The interpretation of these results is discussed [fr

  4. Hot Surface Ignition

    OpenAIRE

    Tursyn, Yerbatyr; Goyal, Vikrant; Benhidjeb-Carayon, Alicia; Simmons, Richard; Meyer, Scott; Gore, Jay P.

    2015-01-01

    Undesirable hot surface ignition of flammable liquids is one of the hazards in ground and air transportation vehicles, which primarily occurs in the engine compartment. In order to evaluate the safety and sustainability of candidate replacement fuels with respect to hot surface ignition, a baseline low lead fuel (Avgas 100 LL) and four experimental unleaded aviation fuels recommended for reciprocating aviation engines were considered. In addition, hot surface ignition properties of the gas tu...

  5. Hydrogen Embrittlement

    Science.gov (United States)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  6. Systematic study of muonic atoms in the A = 100 to A = 140 nuclear-mass regions (isotope and isotone shifts) and model-independent precision measurements of ground-state quadrupole moments of odd-A nuclei. Progress report No. 7, October 16, 1981-October 15, 1982

    International Nuclear Information System (INIS)

    Steffen, R.M.

    1982-10-01

    Until June 1982 all muonic x-ray experiments were performed at the Stopped Muon Channel (SMC) in experimental area A of LAMPF. The SMC channel, consisting of 3 bending magnets and 21 quadrupole magnets, is specifically designed for a clean muon beam and incorporates a long path for the decay of the pions. Recently a number of long-time experiments (rare decay modes of the muon, etc.) have been assigned to the SMC and running time for the muonic x-ray experiments has become very precious. For these reasons considerable time was spent in the summer of 1982 to study the feasibility of doing muonic experiments at the abandoned Biomed channel which has been designed for pion-irradiation therapy of cancer patients. Since the length of the Biomed channel is short, the available experimental area is close to the production target, and hence the neutron background in the experimental area is intolerably large (about 50 times larger than in the SMC experimental area). To reduce this background, the muonic x-ray detector and counter telescope arrangement was modified and surrounded by a concrete and steel shielding house of 1.5 feet minimum wall thickness. The dimensions of the house were 10' x 14' x 6' (H). The background was thus reduced to an acceptable level, even though the signal-to-noise ratio is still twice as large as in the SMC. Nevertheless, the Biomed channel is now usable for Muonic x-ray experiments that do not involve the observation of muonic x-rays of less than 0.5 MeV energy. The muonic x-ray experiments on 233 U described in this Progress Report have been performed at the Biomed channel

  7. Hydrogen millennium

    International Nuclear Information System (INIS)

    Bose, T.K.; Benard, P.

    2000-05-01

    The 10th Canadian Hydrogen Conference was held at the Hilton Hotel in Quebec City from May 28 to May 31, 2000. The topics discussed included current drivers for the hydrogen economy, the international response to these drivers, new initiatives, sustainable as well as biological and hydrocarbon-derived production of hydrogen, defense applications of fuel cells, hydrogen storage on metal hydrides and carbon nanostructures, stationary power and remote application, micro-fuel cells and portable applications, marketing aspects, fuel cell modeling, materials, safety, fuel cell vehicles and residential applications. (author)

  8. Stellar laboratories. VII. New Kr iv - vii oscillator strengths and an improved spectral analysis of the hot, hydrogen-deficient DO-type white dwarf RE 0503-289

    Science.gov (United States)

    Rauch, T.; Quinet, P.; Hoyer, D.; Werner, K.; Richter, P.; Kruk, J. W.; Demleitner, M.

    2016-05-01

    Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims: New Kr iv-vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods: We calculated Kr iv-vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. Results: We reanalyzed the effective temperature and surface gravity and determined Teff = 70000 ± 2000 K and log (g/ cm s-2) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3 ± 0.3 (logarithmic mass fraction). We discovered that the interstellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km s-1Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26666. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 165.H-0588 and 167.D-0407. Based on observations obtained at the German-Spanish Astronomical Center, Calar Alto, operated by the Max-Planck-Institut für Astronomie Heidelberg jointly with the Spanish National Commission for Astronomy.Tables A.9-A.12 are only available via the German

  9. Hydrogen exchange

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    Hydrogen exchange (HX) monitored by mass spectrometry (MS) is a powerful analytical method for investigation of protein conformation and dynamics. HX-MS monitors isotopic exchange of hydrogen in protein backbone amides and thus serves as a sensitive method for probing protein conformation...... and dynamics along the entire protein backbone. This chapter describes the exchange of backbone amide hydrogen which is highly quenchable as it is strongly dependent on the pH and temperature. The HX rates of backbone amide hydrogen are sensitive and very useful probes of protein conformation......, as they are distributed along the polypeptide backbone and form the fundamental hydrogen-bonding networks of basic secondary structure. The effect of pressure on HX in unstructured polypeptides (poly-dl-lysine and oxidatively unfolded ribonuclease A) and native folded proteins (lysozyme and ribonuclease A) was evaluated...

  10. Microbiology of Kamchatka Peninsula Hot Springs

    Science.gov (United States)

    Bonch-Osmolovsk, E.

    2005-12-01

    Hot springs of Uzon Caldera, Geyser Valley, Moutnovsky Volcano (Kamchatka Peninsula) served as the sources of isolation of numerous thermophilic prokaryotes, many of them representing new taxa. Among new isolates there were hyperthermophilic archaea - neutrophilic or acidophilic anaerobic organotrophs, able to use a wide range of polymeric organic substrates. Bacterial isolates were in majority represented by moderate thermophiles - organotrophs and lithoautotrophs. Latter group consisted of anaerobes oxidizing molecular hydrogen in the course of sulfate, sulfur or iron reduction, and of anaerobic CO-oxidizing, hydrogen-producing bacteria. Some of new isolates represented deep phylogenetic lineages in Bacteria domain. Microbial activity in Kamchatka hot springs was studied by means of radioisotopic tracing. The rates of methanogenesis, acetogenesis, inorganic carbon assimilation, acetate oxidation were determined in three different hot springs with pH ranging from 3.0 to 8.5 and water temeperature being in the range from 55 to 85oC. The results indicated the presence and activity of novel metabolic groups of thermophilic prokaryotes that so far have not been known in laboratory cultures.

  11. Geothermal hydrogen - a vision? Paper

    Energy Technology Data Exchange (ETDEWEB)

    Zittel, W.; Weindorf, W.; Wurster, R.; Bussmann, W.

    2001-07-01

    With the progresses in geothermal electricity production by means of the hot-dry-rock (HDR) method electricity might be produced at cost of between 0.07 - 0.09 ECU/kWh, depending on systems sizes of between 5 - 20 MW{sub e}. The electricity can be used to produce hydrogen from electrolysis and water. This method of electricity production offers high availability with operating hour of between 7,600 - 8,000 hours per year. The 40 GWh electricity production per year from one 5 MW{sub e} geothermal plant are sufficient to produce enough hydrogen for the operation of an average fueling station with about 400 refuelings per day at cost of about 20 - 30 percent higher than today's gasoline (including taxes). In this contribution some details of the analysis are presented as well as a general discussion of geothermal hydrogen production as a future energy vector. (orig.)

  12. Hot Weather Tips

    Science.gov (United States)

    ... the person plenty of water and fruit or vegetable juice even if they say they’re not thirsty. No alcohol, coffee or tea. Seek medical help if you suspect dehydration. Light meals: Avoid hot, heavy meals and don’ ...

  13. China's 'Hot Money' Problems

    National Research Council Canada - National Science Library

    Martin, Michael F; Morrison, Wayne M

    2008-01-01

    .... The recent large inflow of financial capital into China, commonly referred to as "hot money," has led some economists to warn that such flows may have a destabilizing effect on China's economy...

  14. Studies on muon cycling rates in muon catalyzed D-T fusion system with possible four-body muonic molecules formation

    International Nuclear Information System (INIS)

    Eskandri, M.R.; Hosini Motlagh, N.; Hataf, A.

    2000-01-01

    In recent studies, it is shown that the fusion rate for four-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ, is considerably larger than that of similar three-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ. It is shown that for dtμμ, fusion rate is R f (dt) ≅ 3 * 10 13 - 6 * * 10 13 S -1 which is 40 times higher than fusion rate of dtμμ molecule. In this paper we have looked for the effect of these molecules formation in muon catalyzed D-T fusion. The required data for all possible branches do not exist, so the main dtμμ branch are considered here. By choosing a variable value for dtμμ molecule formation rate and comparing obtained cycling rates with existing experimental values, the order of this parameter is evaluated to be ≅ 10 9 S -1 . Using obtained data in different conditions of D-T muon cycling rate calculations have shown that considering of four-body molecule formations in existing muon injection intensities do not make considerable change in three-body muonic molecule cycling rate

  15. Reaction of hydrogen atoms with acrylaldehyde

    International Nuclear Information System (INIS)

    Koda, Seiichiro; Nakamura, Kazumoto; Hoshino, Takashi; Hikita, Tsutomu

    1978-01-01

    The reaction of hydrogen atoms with acrylaldehyde was investigated in a fast flow reactor equipped with a time-of-flight type mass spectrometer under reduced pressure. Main reaction products were carbon monoxide, ethylene, ethane, methane, and propanal. Consideration of the distributions of the reaction products under various reaction conditions showed that hydrogen atoms attacked the C=C double bond, especially its inner carbon side under reduced pressure. Resulting hot radicals caused subsequent reactions. The relative value of the apparent bimolecular rate constant of the reaction against that of trans-2-butene with hydrogen atoms was 1.6+-0.2, which supported the above-mentioned initial reaction. (auth.)

  16. Questioning hydrogen

    International Nuclear Information System (INIS)

    Hammerschlag, Roel; Mazza, Patrick

    2005-01-01

    As an energy carrier, hydrogen is to be compared to electricity, the only widespread and viable alternative. When hydrogen is used to transmit renewable electricity, only 51% can reach the end user due to losses in electrolysis, hydrogen compression, and the fuel cell. In contrast, conventional electric storage technologies allow between 75% and 85% of the original electricity to be delivered. Even when hydrogen is extracted from gasified coal (with carbon sequestration) or from water cracked in high-temperature nuclear reactors, more of the primary energy reaches the end user if a conventional electric process is used instead. Hydrogen performs no better in mobile applications, where electric vehicles that are far closer to commercialization exceed fuel cell vehicles in efficiency, cost and performance. New, carbon-neutral energy can prevent twice the quantity of GHG's by displacing fossil electricity than it can by powering fuel cell vehicles. The same is true for new, natural gas energy. New energy resources should be used to displace high-GHG electric generation, not to manufacture hydrogen

  17. Analysis of hydrogen in zirconium metallic

    International Nuclear Information System (INIS)

    Rodrigues, A.N.; Vega Bustillos, J.O.W.

    1991-02-01

    Determination of hydrogen in zirconium metallic have been performed using the hot vacuum extraction system and the gas chromatographic technique. The zirconium metallic samples were hydrieded by electrolitic technique at difference temperatures and times, then the samples were annealing at vacuum and eatching by fluoridric acid solution. The details of the hydrieded process, analytical technique and the data obtained are discussed. (author)

  18. Hydrogen-water isotopic exchange process

    International Nuclear Information System (INIS)

    Cheung, H.

    1984-01-01

    The objects of this invention are achieved by a dual temperature isotopic exchange process employing hydrogen-water exchange with water passing in a closed recirculation loop between a catalyst-containing cold tower and the upper portion of a catalyst-containing hot tower, with feed water being introduced to the lower portion of the hot tower and being maintained out of contact with the water recirculating in the closed loop. Undue retarding of catalyst activity during deuterium concentration can thus be avoided. The cold tower and the upper portion of the hot tower can be operated with relatively expensive catalyst material of higher catalyst activity, while the lower portion of the hot tower can be operated with a relatively less expensive, more rugged catalyst material of lesser catalyst activity. The feed water stream, being restricted solely to the lower portion of the hot tower, requires minimal pretreatment for the removal of potential catalyst contaminants. The catalyst materials are desirably coated with a hydrophobic treating material so as to be substantially inaccessible to liquid water, thereby retarding catalyst fouling while being accessible to the gas for enhancing isotopic exchange between hydrogen gas and water vapor. A portion of the water of the closed loop can be passed to a humidification zone to heat and humidify the circulating hydrogen gas and then returned to the closed loop

  19. Dinamics of hydrogen in terrestrial atmosphere

    International Nuclear Information System (INIS)

    Roamntan, A.; Mercea, V.; Ristoiu, D.; Ursu, D.

    1981-01-01

    Thishs monographic study presents the dynamics of hydrogen in t e Earth's atmosphere. Atomic hydrogen is produced in the homosphere through a complex system of chemical reaction in wich molecules of 2 , H 2 O, C 4 s ''parent '' molecules are involved. The maximum production of H appears at 8O km resulting a concentration of the order of 10 8 cm -3 . There is a correlation between the total mixing ratio of hydrogen in the homosphere and the global escape flux from the Earth's atmosphere. Two new physical mechanisms which may have a substantial contribution to the total escape flux are presented: ''polar wind'' and charge exchange of H with ''hot'' protons. The possibilities of accretion of hydrogen, as atomic hydrogen or as water from the Earth's atmosphere, are analysed in brief. (authors)

  20. Hydrogenating gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nicolardot, P L.F.

    1930-08-06

    Gaseous hydrocarbons obtained by the destructive distillation of carbonaceous materials are simultaneously desulfurized and hydrogenated by passing them at 350 to 500/sup 0/C, mixed with carbon monoxide and water vapor over lime mixed with metallic oxides present in sufficient amount to absorb the carbon dioxide as it is formed. Oxides of iron, copper, silver, cobalt, and metals of the rare earths may be used and are mixed with the lime to form a filling material of small pieces filling the reaction vessel which may have walls metallized with copper and zinc dust. The products are condensed and fixed with absorbents, e.g. oils, activated carbon, silica gels. The metallic masses may be regenerated by a hot air stream and by heating in inert gases.

  1. Energy flux of hot atoms

    International Nuclear Information System (INIS)

    Wotzak, G.P.; Kostin, M.D.

    1976-01-01

    The process in which hot atoms collide with thermal atoms of a gas, transfer kinetic energy to them, and produce additional hot atoms is investigated. A stochastic method is used to obtain numerical results for the spatial and time dependent energy flux of hot atoms in a gas. The results indicate that in hot atom systems a front followed by an intense energy flux of hot atoms may develop

  2. Hydrogen program overview

    Energy Technology Data Exchange (ETDEWEB)

    Gronich, S. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  3. HotRegion: a database of predicted hot spot clusters.

    Science.gov (United States)

    Cukuroglu, Engin; Gursoy, Attila; Keskin, Ozlem

    2012-01-01

    Hot spots are energetically important residues at protein interfaces and they are not randomly distributed across the interface but rather clustered. These clustered hot spots form hot regions. Hot regions are important for the stability of protein complexes, as well as providing specificity to binding sites. We propose a database called HotRegion, which provides the hot region information of the interfaces by using predicted hot spot residues, and structural properties of these interface residues such as pair potentials of interface residues, accessible surface area (ASA) and relative ASA values of interface residues of both monomer and complex forms of proteins. Also, the 3D visualization of the interface and interactions among hot spot residues are provided. HotRegion is accessible at http://prism.ccbb.ku.edu.tr/hotregion.

  4. Metastable hydrogen

    International Nuclear Information System (INIS)

    Dose, V.

    1982-01-01

    This paper deals with the basic physical properties of the metastable 2 2 sub(1/2) state of atomic hydrogen. Applications relying on its special properties, including measurement of the Lamb shift, production of spin-polarized protons and the measurement of molecular electric moments, are discussed. (author)

  5. Studies of b-associated production and muonic decays of neutral Higgs bosons at the ATLAS experiment within the Minimal Supersymmetric Standard Model

    International Nuclear Information System (INIS)

    Warsinsky, Markus

    2008-01-01

    This thesis presents a Monte Carlo study of neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) decaying into muons at the ATLAS experiment at the CERN Large Hadron Collider. Signal and background processes are simulated using novel Monte Carlo generators that incorporate parts of higher order corrections and are expected to give a more accurate prediction than previous programs. The SHERPA Monte Carlo generator is validated for its use in the analysis and compared to results obtained with other programs. Where possible, the Monte Carlo event samples are normalized to higher order calculations. To increase the available Monte Carlo statistics, this study is based on the ATLAS fast detector simulation ATLFAST. Differences between ATLFAST and the detailed detector simulation of ATLAS are examined, and, where possible, correction procedures are devised. A cut based analysis is performed assuming an integrated luminosity of 30 fb -1 , and optimized with respect to the discovery potential for MSSM Higgs bosons. The systematic uncertainties of the event selection and the Monte Carlo predictions are estimated. A method that can be used to estimate the background from data is presented and evaluated. Last, the discovery potential of the ATLAS experiment in the CP conserving benchmark scenarios of the MSSM is evaluated. One or more of the neutral Higgs bosons of the MSSM can be discovered in the muonic decay mode using 30 fb -1 of data for low masses of the pseudoscalar boson A 0 , if the model parameter tan β is at least 20. For higher masses of the A 0 , tan β would need to be significantly higher to ensure a discovery in the studied decay channel. The sensitivity of ATLAS to MSSM Higgs bosons is multiple times larger than the one of previous and currently running experiments. (orig.)

  6. Studies of b-associated production and muonic decays of neutral Higgs bosons at the ATLAS experiment within the Minimal Supersymmetric Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Warsinsky, Markus

    2008-09-15

    This thesis presents a Monte Carlo study of neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) decaying into muons at the ATLAS experiment at the CERN Large Hadron Collider. Signal and background processes are simulated using novel Monte Carlo generators that incorporate parts of higher order corrections and are expected to give a more accurate prediction than previous programs. The SHERPA Monte Carlo generator is validated for its use in the analysis and compared to results obtained with other programs. Where possible, the Monte Carlo event samples are normalized to higher order calculations. To increase the available Monte Carlo statistics, this study is based on the ATLAS fast detector simulation ATLFAST. Differences between ATLFAST and the detailed detector simulation of ATLAS are examined, and, where possible, correction procedures are devised. A cut based analysis is performed assuming an integrated luminosity of 30 fb{sup -1}, and optimized with respect to the discovery potential for MSSM Higgs bosons. The systematic uncertainties of the event selection and the Monte Carlo predictions are estimated. A method that can be used to estimate the background from data is presented and evaluated. Last, the discovery potential of the ATLAS experiment in the CP conserving benchmark scenarios of the MSSM is evaluated. One or more of the neutral Higgs bosons of the MSSM can be discovered in the muonic decay mode using 30 fb{sup -1} of data for low masses of the pseudoscalar boson A{sup 0}, if the model parameter tan {beta} is at least 20. For higher masses of the A{sup 0}, tan {beta} would need to be significantly higher to ensure a discovery in the studied decay channel. The sensitivity of ATLAS to MSSM Higgs bosons is multiple times larger than the one of previous and currently running experiments. (orig.)

  7. Multifragmentation of hot nuclei

    International Nuclear Information System (INIS)

    Tamain, B.

    1990-10-01

    It is difficult to deposit a large amount (∼ 1 Gev) of excitation energy into a nucleus. And if one wants to deposit large excitation energy values, the best way consists of shooting a given target nucleus with several nucleons, which can be achieved by using intermediate energy (10-100 MeV/nucleon) heavy ions. Such very excited objects were named hot nuclei. The study of hot nuclei has been undertaken only for 7 years because intermediate energy heavy ion facilities were not available before. The game is then to determine the decay properties of such nuclei, their limits of existence. Their study is connected with general properties of nuclear matter: namely its equation of state. Of special interest, is the onset of a new decay mechanism: multifragmentation, which is the non-sequential disassembly of a hot nucleus into several light nuclei (often called intermediate-mass fragments or IMF) or particles. This paper, shows how this mechanism can reflect fundamental properties of nuclear matter, but also how its experimental signature is difficult to establish. Multifragmentation has also been studied by using very energetic projectiles (protons and heavy ions) in the relativistic or ultra-relativistic region. The multifragmentation question of hot nuclei is far from being solved. One knows that IMF production increases when the excitation energy brought into a system is strongly increased, but very little is known about the mechanisms involved and a clear onset for multifragmentation is not established

  8. Utilizing hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Nozik, Arthur J.

    2018-03-01

    In current solar cells, any photon energy exceeding the semiconductor bandgap is lost before being collected, limiting the cell performance. Hot carrier solar cells could avoid these losses. Now, a detailed experimental study and analysis shows that this strategy could lead to an improvement of the photoconversion efficiency in practice.

  9. Mechanical shielded hot cell

    International Nuclear Information System (INIS)

    Higgy, H.R.; Abdel-Rassoul, A.A.

    1983-01-01

    A plan to erect a mechanical shielded hot cell in the process hall of the Radiochemical Laboratory at Inchas is described. The hot cell is designed for safe handling of spent fuel bundles, from the Inchas reactor, and for dismantling and cutting the fuel rods in preparation for subsequent treatment. The biological shielding allows for the safe handling of a total radioactivity level up to 10,000 MeV-Ci. The hot cell consists of an α-tight stainless-steel box, connected to a γ-shielded SAS, through an air-lock containing a movable carriage. The α-box is tightly connected with six dry-storage cavities for adequate storage of the spent fuel bundles. Both the α-box, with the dry-storage cavities, and the SAS are surrounded by 200-mm thick biological lead shielding. The α-box is equipped with two master-slave manipulators, a lead-glass window, a monorail crane and Padirac and Minirag systems. The SAS is equipped with a lead-glass window, tong manipulator, a shielded pit and a mechanism for the entry of the spent fuel bundle. The hot cell is served by adequate ventilation and monitoring systems. (author)

  10. Industrial implications of hydrogen

    International Nuclear Information System (INIS)

    Pressouyre, G.M.

    1982-01-01

    Two major industrial implications of hydrogen are examined: problems related to the effect of hydrogen on materials properties (hydrogen embrittlement), and problems related to the use and production of hydrogen as a future energy vector [fr

  11. A Measurement of the Rate of Muon Capture in Hydrogen Gas and Determination of the Proton's Induced Pseudoscalar Coupling gp

    International Nuclear Information System (INIS)

    Banks, Thomas Ira

    2007-01-01

    This dissertation describes a measurement of the rate of nuclear muon capture by the proton, performed by the MuCap Collaboration using a new technique based on a time projection chamber operating in ultraclean, deuterium-depleted hydrogen gas at room temperature and 1 MPa pressure. The hydrogen target's low gas density of 1 percent compared to liquid hydrogen is key to avoiding uncertainties that arise from the formation of muonic molecules. The capture rate was obtained from the difference between the mu- disappearance rate in hydrogen--as determined from data collected in the experiment's first physics run in fall2004--and the world average for the mu+ decay rate. After combining the results of my analysis with the results from another independent analysis of the 2004 data, the muon capture rate from the hyperfine singlet ground state of the mu-p atom is found to be Λ S = 725.0 ± 17.4 1/s, from which the induced pseudoscalar coupling of the nucleon, gP(q2 = -0.88m2mu)= 7.3 ± 1.1, is extracted. This result for gP is consistent with theoretical predictions that are based on the approximate chiral symmetry of QCD

  12. Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

    Science.gov (United States)

    Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

    2018-03-01

    The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

  13. Software Simulation of Hot Tearing

    DEFF Research Database (Denmark)

    Andersen, S.; Hansen, P.N.; Hattel, Jesper Henri

    1999-01-01

    The brittleness of a solidifying alloy in a temperature range near the solidus temperature has been recognised since the fifties as the mechanism responsible for hot tearing. Due to this brittlenes, the metal will crack under even small amounts of strain in that temperature range. We see these hot...... tears in castings close to hot centres, where the level of strain is often too high.Although the hot tearing mechanism is well understood, until now it has been difficult to do much to reduce the hot tearing tendency in a casting. In the seventies, good hot tearing criteria were developed by considering...... the solidification rate and the strain rate of the hot tear prone areas. But, until recently it was only possible to simulate the solidification rate, so that the criteria could not be used effectively.Today, with new software developments, it is possible to also simulate the strain rate in the hot tear prone areas...

  14. Hot Fuel Examination Facility (HFEF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hot Fuel Examination Facility (HFEF) is one of the largest hot cells dedicated to radioactive materials research at Idaho National Laboratory (INL). The nation's...

  15. Preliminary analysis of hydrogen risk caused by dust in ITER

    International Nuclear Information System (INIS)

    Cheng Kun; Tong Lili; Cao Xuewu

    2012-01-01

    A lot of dust will be generated during ITER operation,and hydrogen will be produced by the interaction of hot dust with water in the case of coolant ingress accident. The accumulated hydrogen will bring risk of combustion and explosion,which will damage the device. CFD method has been used to analyze the produced hydrogen in 'wet bypass' scenario, and come to the results that hydrogen will burn and explode at the beginning of the accident, different hydrogen risk will be brought by different coolant leakage, and hydrogen risk will be inert if the leakage is massive.Injecting CO 2 to inert the vacuum vessel has also been discussed, the risk of hydrogen will be suppressed by injecting CO 2 with a large rate at the beginning of accident. (authors)

  16. THE HOT INTERSTELLAR MEDIUM OF THE INTERACTING GALAXY NGC 4490

    International Nuclear Information System (INIS)

    Richings, A. J.; Fabbiano, G.; Wang Junfeng; Roberts, T. P.

    2010-01-01

    We present an analysis of the hot interstellar medium (ISM) in the spiral galaxy NGC 4490, which is interacting with the irregular galaxy NGC 4485, using ∼100 ks of Chandra ACIS-S observations. The high angular resolution of Chandra enables us to remove discrete sources and perform spatially resolved spectroscopy for the star-forming regions and associated outflows, allowing us to look at how the physical properties of the hot ISM such as temperature, hydrogen column density, and metal abundances vary throughout these galaxies. We find temperatures of >0.41 keV and 0.85 +0.59 -0.12 keV, electron densities of >1.87η -1/2 x 10 -3 cm -3 and 0.21 +0.03 -0.04 η -1/2 x 10 -3 cm -3 , and hot gas masses of >1.1η 1/2 x 10 7 M sun and ∼3.7η 1/2 x 10 7 M sun in the plane and halo of NGC 4490, respectively, where η is the filling factor of the hot gas. The abundance ratios of Ne, Mg, and Si with respect to Fe are found to be consistent with those predicted by theoretical models of type II supernovae (SNe). The thermal energy in the hot ISM is ∼5% of the total mechanical energy input from SNe, so it is likely that the hot ISM has been enriched and heated by type II SNe. The X-ray emission is anticorrelated with the Hα and mid-infrared emission, suggesting that the hot gas is bounded by filaments of cooler ionized hydrogen mixed with warm dust.

  17. Hot subluminous star: HDE 283048

    International Nuclear Information System (INIS)

    Laget, M.; Vuillemin, A.; Parsons, S.B.; Henize, K.G.; Wray, J.D.

    1978-01-01

    The star HDE 283048, located at α = 3/sup h/50/sup m/.3, delta = +25 0 36', shows a strong ultraviolet continuum. Ground-based observations indicate a hot-dominated composite spectrum. Several lines of evidence suggest that the hot component is a hot subdwarf. 2 figures

  18. Hot chocolate effect

    International Nuclear Information System (INIS)

    Crawford, F.S.

    1982-01-01

    The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments

  19. Hot water reticulation

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, S. K.

    1977-10-15

    Hot water reticulation (district heating) is an established method of energy supply within cities in many countries. It is based on the fact that heat can often be obtained cheaply in bulk, and that the resultant savings can, in suitable circumstances, justify the investment in a reticulation network of insulated pipes to distribute the heat to many consumers in the form of hot water or occasionally steam. The heat can be used by domestic, commercial, and industrial consumers for space heating and water heating, and by industries for process heat. The costs of supplying domestic consumers can be determined by considering an average residential area, but industrial and commercial consumers are so varied in their requirements that every proposal must be treated independently. Fixed costs, variable costs, total costs, and demand and resource constraints are discussed.

  20. The hot chocolate effect

    Science.gov (United States)

    Crawford, Frank S.

    1982-05-01

    The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

  1. Hot air balloon engine

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, Ian [Solartran Pty Ltd, 12 Lentara Street, Kenmore, Brisbane 4069 (Australia)

    2009-04-15

    This paper describes a solar powered reciprocating engine based on the use of a tethered hot air balloon fuelled by hot air from a glazed collector. The basic theory of the balloon engine is derived and used to predict the performance of engines in the 10 kW to 1 MW range. The engine can operate over several thousand metres altitude with thermal efficiencies higher than 5%. The engine thermal efficiency compares favorably with the efficiency of other engines, such as solar updraft towers, that also utilize the atmospheric temperature gradient but are limited by technical constraints to operate over a much lower altitude range. The increased efficiency allows the use of smaller area glazed collectors. Preliminary cost estimates suggest a lower $/W installation cost than equivalent power output tower engines. (author)

  2. The ''hot'' patella

    International Nuclear Information System (INIS)

    Kipper, M.S.; Alazraki, N.P.; Feiglin, D.H.

    1982-01-01

    Increased patellar uptake on bone scans is seen quite commonly but the possible or probable etiologies of this finding have not been previously well described. A review of 100 consecutive bone scans showed that the incidence of bilateral ''hot'' patellae is 15%. Identified etiologies include osteoarthritic degenerative disease (35%), fracture, possible metastatic disease, bursitis, Paget's disease, and osteomyelitis. The value of careful history, physical examination, and radiographs is stressed

  3. Hot nuclei and fragmentation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1993-01-01

    A review is made of the present status concerning the production of nuclei above 5 MeV temperature. Considerable progress has been made recently on the understanding of the formation and the fate of such hot nuclei. It appears that the nucleus seems more stable against temperature than predicted by static calculations. However, the occurrence of multifragment production at high excitation energies is now well established. The various experimental features of the fragmentation process are discussed. (author) 59 refs., 12 figs

  4. 'Hot particle' intercomparison dosimetry

    International Nuclear Information System (INIS)

    Kaurin, D.G.L.; Baum, J.W.; Charles, M.W.; Darley, D.P.J.; Durham, J.S.; Scannell, M.J.; Soares, C.G.

    1996-01-01

    Dosimetry measurements of four 'hot particles' were made at different density thickness values using five different methods. The hot particles had maximum dimensions of 650 μm and maximum beta energies of 0.97, 046, 0.36, and 0.32 MeV. Absorbers were used to obtain the dose at different depths for each dosimeter. Measurements were made using exoelectron dosimeters, an extrapolation chamber, NE Extremity Tape Dosimeters (tm), Eberline RO-2 and RO-2A survey meters, and two sets of GafChromic (tm) dye film with each set read out at a different institution. From these results the dose was calculated averaged over 1 cm 2 of tissue at 18, 70, 125, and 400 μm depth. Comparisons of tissue-dose averaged over 1 cm 2 for 18, 70, and 125 μm depth based on interpolated measured values, were within 30% for the GafChromic (tm) dye film, extrapolation chamber, NE Extremity Tape Dosimeters (tm), and Eberline RO-2 and 2A (tm) survey meters except for the hot particle with 0.46 MeV maximum beta energy. The results for this source showed differences of up to 60%. The extrapolation chamber and NE Extremity Tape dosimeters under-responded for measurements at 400 μm by about a factor of 2 compared with the GafChromic dye films for two hot particles with maximum beta energy of 0.32 and 0.36 MeV which each emitted two 100% 1 MeV photons per disintegration. Tissue doses determined using exoelectron dosimeters were a factor of 2 to 5 less than those determined using other dosimeters, possibly due to failures of the equipment. (author)

  5. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  6. Precision spectroscopy of the 2S-4P{sub 1/2} transition in atomic hydrogen on a cold thermal beam of optically excited 2S atoms

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Axel; Kolachevsky, Nikolai; Alnis, Janis; Yost, Dylan C.; Matveev, Arthur; Parthey, Christian G.; Pohl, Randolf; Udem, Thomas [Max-Planck-Institut fuer Quantenoptik, 85748 Garching (Germany); Khabarova, Ksenia [FSUE ' VNIIFTRI' , 141570 Moscow (Russian Federation); Haensch, Theodor W. [Max-Planck-Institut fuer Quantenoptik, 85748 Garching (Germany); Ludwig-Maximilians-Universitaet, 80799 Muenchen (Germany)

    2013-07-01

    The 'proton size puzzle', i.e. the discrepancy between the values for the proton r.m.s. charge radius deduced from precision spectroscopy of atomic hydrogen and electron-proton-scattering on one side and the value deduced from muonic hydrogen spectroscopy on the other side, has been persisting for more than two years now. Although huge efforts have been put into trying to resolve this discrepancy from experimental and theoretical side, no convincing argument could be found so far. In this talk, we report on a unique precision spectroscopy experiment on atomic hydrogen, which is aiming to bring some light to the hydrogen part of the puzzle: In contrast to any previous high resolution experiment probing a transition frequency between the meta-stable 2S state and a higher lying nL state (n=3,4,6,8,12, L=S,P,D), our measurement of the 2S-4P{sub 1/2} transition frequency is the first experiment being performed on a cold thermal beam of hydrogen atoms optically excited to the 2S state. We will discuss how this helps to efficiently suppresses leading systematic effects of previous measurements and present the preliminary results we obtained so far.

  7. The hydrogen; L'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The hydrogen as an energy system represents nowadays a main challenge (in a scientific, economical and environmental point of view). The physical and chemical characteristics of hydrogen are at first given. Then, the challenges of an hydrogen economy are explained. The different possibilities of hydrogen production are described as well as the distribution systems and the different possibilities of hydrogen storage. Several fuel cells are at last presented: PEMFC, DMFC and SOFC. (O.M.)

  8. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    Science.gov (United States)

    Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

    1988-01-01

    Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

  9. VARIABILITY IN HOT CARBON-DOMINATED ATMOSPHERE (HOT DQ) WHITE DWARFS: RAPID ROTATION?

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kurtis A.; Bierwagen, Michael [Department of Physics and Astrophysics, Texas A and M University-Commerce, P.O. Box 3011, Commerce, TX, 75429 (United States); Montgomery, M. H.; Winget, D. E.; Falcon, Ross E., E-mail: Kurtis.Williams@tamuc.edu [Department of Astronomy, University of Texas, 1 University Station C1400, Austin, TX, 78712 (United States)

    2016-01-20

    Hot white dwarfs (WDs) with carbon-dominated atmospheres (hot DQs) are a cryptic class of WDs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This variability has been ascribed to nonradial pulsations, but increasing data call this explanation into question. We present studies of short-term variability in seven hot DQ WDs. Three (SDSS J1426+5752, SDSS J2200−0741, and SDSS J2348−0942) were known to be variable. Their photometric modulations are coherent over at least two years, and we find no evidence for variability at frequencies that are not harmonics. We present the first time-series photometry for three additional hot DQs (SDSS J0236−0734, SDSS J1402+3818, and SDSS J1615+4543); none are observed to vary, but the signal-to-noise is low. Finally, we present high speed photometry for SDSS J0005−1002, known to exhibit a 2.1-day photometric variation; we do not observe any short-term variability. Monoperiodicity is rare among pulsating WDs, so we contemplate whether the photometric variability is due to rotation rather than pulsations; similar hypotheses have been raised by other researchers. If the variability is due to rotation, then hot DQ WDs as a class contain many rapid rotators. Given the lack of companions to these stars, the origin of any fast rotation is unclear—both massive progenitor stars and double degenerate merger remnants are possibilities. We end with suggestions of future work that would best clarify the nature of these rare, intriguing objects.

  10. Determination of hydrogen in metals and alloys

    International Nuclear Information System (INIS)

    Sayi, Y.S.; Ramanjaneyulu, P.S.; Ramakumar, K.L.

    2008-01-01

    Hydrogen will be invariably present in all materials. Its presence in excess is harmful and sometimes calamitous. Hydrogen embrittlement can occur quite readily in most high strength materials, irrespective of their composition or structure. It is therefore essential to maintain low levels of hydrogen. To know the amount of hydrogen present in the materials, it is essential to determine it with high degree of precision and accuracy. It is required to give the uncertainty associated with the measurement to increase the confidence on measurements. Several methodologies are available for the determination of hydrogen. It its isotope, deuterium, also co-exists it becomes all the more difficult to determine these individually. Hot vacuum extraction cum quadrupole mass spectrometry (HVE-QMS) developed in our laboratory to determine hydrogen and deuterium is routinely employed for the determination of hydrogen and deuterium in metals and alloys. The present paper deals in detail about our experiences with HVE-QMS and estimation of uncertainty associated in this methodology. (author)

  11. Emerging hot spot analysis

    DEFF Research Database (Denmark)

    Reinau, Kristian Hegner

    Traditionally, focus in the transport field, both politically and scientifically, has been on private cars and public transport. Freight transport has been a neglected topic. Recent years has seen an increased focus upon congestion as a core issue across Europe, resulting in a great need for know...... speed data for freight. Secondly, the analytical methods used, space-time cubes and emerging hot spot analysis, are also new in the freight transport field. The analysis thus estimates precisely how fast freight moves on the roads in Northern Jutland and how this has evolved over time....

  12. Progress in hot pressing

    International Nuclear Information System (INIS)

    Brodhag, C.; Thevenot, F.

    1988-01-01

    An experimental technique is described to study hot pressing of ceramics under conditions of controlled temperature and pressure during both the heating and final sintering stages. This method gives a better control of the final microstructure of the material. Transformation mechanisms can be studied during initial heating stage (impurity degasing, reaction, phase transformation, mechanical behavior of intergranular phase...) using computer control and graphical data representations. Some examples will be given for different systems studied in our laboratory: B (α, β, amorphous), B 12 O 2 (reaction of B + B 2 O 3 ), Si 3 N 4 ( + additives), TiN, Al 2 O 3 + AlON,ZrC

  13. Multipurpose reprocessing hot cell

    International Nuclear Information System (INIS)

    Fletcher, R.D.

    1975-01-01

    A multipurpose hot cell is being designed for use at the Idaho Chemical Processing Plant for handling future scheduled fuels that cannot be adequately handled by the existing facilities and equipment. In addition to providing considerable flexibility to handle a wide variety of fuel sizes up to 2,500 lb in weight the design will provide for remote maintenance or replacement of the in-cell equipment with a minimum of exposure to personnel and also provide process piping connections for custom processing of small quantities of fuel. (auth)

  14. Nanocrystalline electrodeposited Ni-Mo-C cathodes for hydrogen production

    International Nuclear Information System (INIS)

    Hashimoto, K.; Sasaki, T.; Meguro, S.; Asami, K.

    2004-01-01

    Tailoring active nickel alloy cathodes for hydrogen evolution in a hot concentrated hydroxide solution was attempted by electrodeposition. The carbon addition to Ni-Mo alloys decreased the nanocrystalline grain size and remarkably enhanced the activity for hydrogen evolution, changing the mechanism of hydrogen evolution. The Tafel slope of hydrogen evolution was about 35 mV per decade. This suggested that the rate-determining step is desorption of adsorbed hydrogen atoms by recombination. As was distinct from the binary Ni-Mo alloys, after open circuit immersion, the overpotential, that is, the activity of nanocrystalline Ni-Mo-C alloys for hydrogen evolution was not changed, indicating the sufficient durability in the practical electrolysis

  15. Detection of hydrogen buildup in initially pure nonhydrogenous liquids

    International Nuclear Information System (INIS)

    McNeany, S.R.; Jenkins, J.D.

    1978-12-01

    A technique for monitoring hydrogen buildup in initially pure nonhydrogenous liquids is described in this report. The detection method is based upon the neutron-moderating properties of hydrogen. The analysis leading to the selection and design of a hydrogen-monitoring device is described. An experimental mockup of the device was then constructed and tested for hydrogen sensitivity. A hot cell was used for these tests. A device proved capable of measuring hydrogen concentrations in the range of 0 to 13.0 x 10 27 atoms/m 3 , with an accuracy of about 1.0 x 10 27 atoms/m 3 . A typical measurement can be made in 3 to 5 min. The experimental results confirmed the sensitivities predicted by the analysis and demonstrated that such a device would be practical for hydrogen concentration measurements for criticality control in an HTGR fuel refabrication plant

  16. Reactions of Hot Hydrogen Atoms with Ethylene. The Role of Excited Ethyl Radicals as Intermediate Products; Reactions des Atomes Chauds d'Hydrogene avec l'Ethylene. Le Role des Radicaux Ethyle Excites Comme Produits Intermediaires; Reaktsiya goryachikh atomov vodoroda s ehtilenom. Rol' vozbuzhdennykh ehtil'nykh radikalov kak promezhutochnykh produktov; Reacciones de Atomos Calientes de Hidrogeno con Etileno Papel de los Radicales Etilicos Excitados como Productos Intermedios

    Energy Technology Data Exchange (ETDEWEB)

    Dzantiev, B. G.; Shvedchikov, A. P. [Institut Himicheskoj Fiziki AN SSSR, SSSR (Russian Federation)

    1965-04-15

    It is well known that the nuclear reactions Li{sup 6}(n, {alpha})T and He{sup 3}(n, p) T result in the formation of hot atoms of radioactive hydrogen. The characteristics of the chemical consequences of nuclear transformations are largely determined by the high chemical activity of such atoms. However, hydrogen atoms can play an essential role not only in nuclear chemistry but also in other branches of high-energy chemistry, such as radiolysis and photolysis. In the present research we attempted to make a comparative study of the behaviour of hot hydrogen atoms obtained in various ways: by the Li{sup 6} (n, {alpha})T reaction (recoil energy = 2.7 MeV); by radiolysis (E{approx} a few eV); by photolysis (E{approx} 1 - 1,5 eV; hot hydrogen is obtained from HI by photolysis at {lambda} = 2537A). In order to obtain tritium atoms, we used crystals and films of Li{sub 2}Co{sub 3}, Li{sup 6}F, Li{sup 6}OH, Li{sup 6}BO{sub 2} * 8H{sub 2} as targets. Gaseous ethylene (P = 5-10 atm) and its mixtures with ammonia, helium and inhibitors, were subjected to radiation. Radiation was carried out on an IRT-1000 reactor with a thermal neutron flux of 10{sup 11} - 10{sup 12} a/cm{sup 2} * s. Tritium-labelled compounds and products of radiation chemistry reactions were identified by gas chromatography involving the use of two monitoring units connected in series (a katharometer and a G-M flow counter). It is shown that the spectrum of labelled and unlabelled products in irradiated ethylene is very distinct. The main labelled products are C{sub 2}H{sub 2}, C{sub 2}H{sub 6}, C{sub 4}H{sub 10} and hydrocarbons > C{sub 4}; the H{sub 2} yield is small. The main unlabelled products are HT, C{sub 2}H{sub 3}T and C{sub 4}H{sub 9}T; the yield of C{sub 2}H{sub 5}T and especially of C{sub 2}HT is insignificant. The labelled-compound yields are dependent on the introduction of additives (ammonia, helium, iodine) into the ethylene, on the type of lithium-containing compound and on the structure of

  17. Residential solar hot water

    Energy Technology Data Exchange (ETDEWEB)

    1982-06-01

    This report examines the feasibility of using solar energy to preheat domestic water coming from the city supply at a temperature of approximately 4{degree}C. Four solar collectors totalling 7 m{sup 2} were installed on a support structure facing south at an angle of 60{degree} from the horizontal. The system worked most efficiently in the spring and early summer when the combination of long hours of sunshine, clean air and clear skies allowed for maximum availability of solar radiation. Performance dropped in late summer and fall mainly due to cloudier weather conditions. The average temperature in the storage tank over the 10 months of operation was 42{degree}C, ranging from a high of 83{degree}C in July to a low of 6{degree}C in November. The system provided a total of 7.1 GJ, which is approximately one-third the annual requirement for domestic hot water heating. At the present time domestic use of solar energy to heat water does not appear to be economically viable. High capital costs are the main problem. As a solar system with present day technology can only be expected to meet half to two-thirds of the hot water energy demand the savings are not sufficient for the system to pay for itself within a few years. 5 figs.

  18. Destructive hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Terrisse, H; Dufour, L

    1929-01-21

    Oils of high boiling point, e.g. gas oil, lamp oil, schist oil, brown coal tar etc., are converted into motor benzine by heating them at 200 to 500/sup 0/C under pressure of 5 to 40 kilograms/cm/sup 2/ in the presence of ferrous chloride and gases such as hydrogen, or water gas, the desulfurization of the oils proceeding simultaneously. One kilogram of lamp oil and 100 g. ferrous chloride are heated in an autoclave in the presence of water gas under a pressure of 18 kg/cm/sup 2/ to 380 to 400/sup 0/C. The gaseous products are allowed to escape intermittently and are replaced by fresh water gas. A product distilling between 35 and 270/sup 0/C is obtained.

  19. 16. Hot dense plasma atomic processes

    International Nuclear Information System (INIS)

    Werner, Dappen; Totsuji, H.; Nishii, Y.

    2002-01-01

    This document gathers 13 articles whose common feature is to deal with atomic processes in hot plasmas. Density functional molecular dynamics method is applied to the hydrogen plasma in the domain of liquid metallic hydrogen. The effects of the density gradient are taken into account in both the electronic kinetic energy and the exchange energy and it is shown that they almost cancel with each other, extending the applicability of the Thomas-Fermi-Dirac approximation to the cases where the density gradient is not negligible. Another article reports about space and time resolved M-shell X-ray measurements of a laser-produced gas jet xenon plasma. Plasma parameters have been measured by ion acoustic and electron plasma waves Thomson scattering. Photo-ionization becomes a dominant atomic process when the density and the temperature of plasmas are relatively low and when the plasma is submitted to intense external radiation. It is shown that 2 plasmas which have a very different density but have the same ionization parameters, are found in a similar ionization state. Most radiation hydrodynamics codes use radiative opacity data from available libraries of atomic data. Several articles are focused on the determination of one group Rosseland and Planck mean analytical formulas for several single elements used in inertial fusion targets. In another paper the plasma density effect on population densities, effective ionization, recombination rate coefficients and on emission lines from carbon and Al ions in hot dense plasma, is studied. The last article is devoted to a new atomic model in plasmas that considers the occupation probability of the bound state and free state density in the presence of the plasma micro-field. (A.C.)

  20. Hot springs in Hokuriku District

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K. (Hot Springs Research Center, Japan)

    1971-01-01

    In the Hokuriku district including Toyama, Ishikawa, and Fukui Prefectures, hot springs of more than 25/sup 0/C were investigated. In the Toyama Prefecture, there are 14 hot springs which are located in an area from the Kurobe River to the Tateyama volcano and in the mountainous area in the southwest. In Ishikawa Prefecture there are 16 hot springs scattered in Hakusan and its vicinity, the Kaga mountains, and in the Noto peninsula. In northern Fukui Prefecture there are seven hot springs. The hot springs in Shirakawa in Gifu Prefecture are characterized as acid springs producing exhalations and H/sub 2/S. These are attributed to the Quaternary volcanoes. The hot springs of Wakura, Katayamazu, and Awara in Ishikawa Prefecture are characterized by a high Cl content which is related to Tertiary andesite. The hot springs of Daishoji, Yamanaka, Yamashiro, Kuritsu, Tatsunokuchi, Yuwaku, and Yunotani are characterized by a low HCO/sub 3/ content. The Ca and SO/sub 4/ content decreases from east to west, and the Na and Cl content increases from west to east. These fluctuations are related to the Tertiary tuff and rhyolite. The hot springs of Kuronagi, Kinshu, and Babadani, located along the Kurobe River are characterized by low levels of dissolved components and high CO/sub 2/ and HCO/sub 3/ content. These trends are related to late Paleozoic granite. Hot springs resources are considered to be connected to geothermal resources. Ten tables, graphs, and maps are provided.

  1. Multifunctional Hot Structure Heat Shield

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is performing preliminary development of a Multifunctional Hot Structure (HOST) heat shield for planetary entry. Results of this development will...

  2. A Measurement of the Rate of Muon Capture in Hydrogen Gas andDetermination of the Proton's Induced Pseudoscalar Coupling gP

    Energy Technology Data Exchange (ETDEWEB)

    Banks, Thomas Ira [Univ. of California, Berkeley, CA (United States)

    2007-07-01

    This dissertation describes a measurement of the rate ofnuclear muon capture by the proton, performed by the MuCap Collaborationusing a new technique based on a time projection chamber operating inultraclean, deuterium-depleted hydrogen gas at room temperature and 1 MPapressure. The hydrogen target's low gas density of 1 percent compared toliquid hydrogen is key to avoiding uncertainties that arise from theformation of muonic molecules. The capture rate was obtained from thedifference between the μ- disappearance rate in hydrogen--as determinedfrom data collected in the experiment's first physics run in fall2004--and the world averagefor the μ+ decay rate. After combining theresults of my analysis with the results from another independent analysisof the 2004 data, the muon capture rate from the hyperfine singlet groundstate of the mu-p atom is found to be ΛS = 725.0 ± 17.4 1/s, fromwhich the induced pseudoscalar coupling of the nucleon, gP(q2 = -0.88m$2\\atop{μ}$)= 7.3 ± 1.1, is extracted. This result for gP is consistent withtheoretical predictions that are based on the approximate chiral symmetryof QCD.

  3. Multiscale modelling and experimentation of hydrogen embrittlement in aerospace materials

    Science.gov (United States)

    Jothi, Sathiskumar

    Pulse plated nickel and nickel based superalloys have been used extensively in the Ariane 5 space launcher engines. Large structural Ariane 5 space launcher engine components such as combustion chambers with complex microstructures have usually been manufactured using electrodeposited nickel with advanced pulse plating techniques with smaller parts made of nickel based superalloys joined or welded to the structure to fabricate Ariane 5 space launcher engines. One of the major challenges in manufacturing these space launcher components using newly developed materials is a fundamental understanding of how different materials and microstructures react with hydrogen during welding which can lead to hydrogen induced cracking. The main objective of this research has been to examine and interpret the effects of microstructure on hydrogen diffusion and hydrogen embrittlement in (i) nickel based superalloy 718, (ii) established and (iii) newly developed grades of pulse plated nickel used in the Ariane 5 space launcher engine combustion chamber. Also, the effect of microstructures on hydrogen induced hot and cold cracking and weldability of three different grades of pulse plated nickel were investigated. Multiscale modelling and experimental methods have been used throughout. The effect of microstructure on hydrogen embrittlement was explored using an original multiscale numerical model (exploiting synthetic and real microstructures) and a wide range of material characterization techniques including scanning electron microscopy, 2D and 3D electron back scattering diffraction, in-situ and ex-situ hydrogen charged slow strain rate tests, thermal spectroscopy analysis and the Varestraint weldability test. This research shows that combined multiscale modelling and experimentation is required for a fundamental understanding of microstructural effects in hydrogen embrittlement in these materials. Methods to control the susceptibility to hydrogen induced hot and cold cracking and

  4. Hot Gas Halos in Galaxies

    Science.gov (United States)

    Mulchaey, John

    Most galaxy formation models predict that massive low-redshift disk galaxies are embedded in extended hot halos of externally accreted gas. Such gas appears necessary to maintain ongoing star formation in isolated spirals like the Milky Way. To explain the large population of red galaxies in rich groups and clusters, most galaxy evolution models assume that these hot gas halos are stripped completely when a galaxy enters a denser environment. This simple model has been remarkably successful at reproducing many observed properties of galaxies. Although theoretical arguments suggest hot gas halos are an important component in galaxies, we know very little about this gas from an observational standpoint. In fact, previous observations have failed to detect soft X-ray emission from such halos in disk galaxies. Furthermore, the assumption that hot gas halos are stripped completely when a galaxy enters a group or cluster has not been verified. We propose to combine proprietary and archival XMM-Newton observations of galaxies in the field, groups and clusters to study how hot gas halos are impacted by environment. Our proposed program has three components: 1) The deepest search to date for a hot gas halo in a quiescent spiral galaxy. A detection will confirm a basic tenet of disk galaxy formation models, whereas a non-detection will seriously challenge these models and impose new constraints on the growth mode and feedback history of disk galaxies. 2) A detailed study of the hot gas halos properties of field early-type galaxies. As environmental processes such as stripping are not expected to be important in the field, a study of hot gas halos in this environment will allow us to better understand how feedback and other internal processes impact hot gas halos. 3) A study of hot gas halos in the outskirts of groups and clusters. By comparing observations with our suite of simulations we can begin to understand what role the stripping of hot gas halos plays in galaxy

  5. Hydrogen Annealing Of Single-Crystal Superalloys

    Science.gov (United States)

    Smialek, James L.; Schaeffer, John C.; Murphy, Wendy

    1995-01-01

    Annealing at temperature equal to or greater than 2,200 degrees F in atmosphere of hydrogen found to increase ability of single-crystal superalloys to resist oxidation when subsequently exposed to oxidizing atmospheres at temperatures almost as high. Supperalloys in question are principal constituents of hot-stage airfoils (blades) in aircraft and ground-based turbine engines; also used in other high-temperature applications like chemical-processing plants, coal-gasification plants, petrochemical refineries, and boilers. Hydrogen anneal provides resistance to oxidation without decreasing fatigue strength and without need for coating or reactive sulfur-gettering constituents. In comparison with coating, hydrogen annealing costs less. Benefits extend to stainless steels, nickel/chromium, and nickel-base alloys, subject to same scale-adhesion and oxidation-resistance considerations, except that scale is chromia instead of alumina.

  6. Hot cell verification facility update

    International Nuclear Information System (INIS)

    Titzler, P.A.; Moffett, S.D.; Lerch, R.E.

    1985-01-01

    The Hot Cell Verification Facility (HCVF) provides a prototypic hot cell mockup to check equipment for functional and remote operation, and provides actual hands-on training for operators. The facility arrangement is flexible and assists in solving potential problems in a nonradioactive environment. HCVF has been in operation for six years, and the facility is a part of the Hanford Engineering Development Laboratory

  7. The Wolf-Rayet hydrogen puzzle -- an observational point of view

    OpenAIRE

    Foellmi, C.; Marchenko, S. V.; Moffat, A. F. J.

    2005-01-01

    Significant amounts of hydrogen were found in very hot early-type single WN stars in the SMC and the LMC. Recently, we found similar evidence in the Wolf-Rayet star of a short-period LMC binary. We discuss here the relevance of hydrogen for WR star classification, models, the relation to metallicity, and the GRB progenitors.

  8. Imaging hydrogen flames by two-photon, laser-induced fluorescence

    Science.gov (United States)

    Miles, R.; Lempert, W.; Kumar, V.; Diskin, G.

    1991-01-01

    A nonintrusive multicomponent imaging system is developed which can image hydrogen, hot oxygen, and air simultaneously. An Ar-F excimer laser is injection-locked to cover the Q1 two-photon transition in molecular hydrogen which allows the observation of both hot oxygen and cold hydrogen. Rayleigh scattering from the water molecules occurs at the same frequency as the illuminating laser allowing analysis of the air density. Images of ignited and nonignited hydrogen jets are recorded with a high-sensitivity gated video camera. The images permit the analysis of turbulent hydrogen-core jet, the combustion zone, and the surrounding air, and two-dimensional spatial correlations can be made to study the turbulent structure and couplings between different regions of the flow field. The method is of interest to the study of practical combustion systems which employ hydrogen-air diffusion flames.

  9. Solar photocatalytic generation of hydrogen under ultraviolet-visible ...

    Indian Academy of Sciences (India)

    Administrator

    solar energy has been regarded as an attractive solution to resolve the global energy ... simultaneous hydrogen production and H2S decomposi- tion is a highly ... of CdCO3 and ZnCO3 in dilute acetic acid at 60–70°C. Mixing slowly the hot ...

  10. Electric arc hydrogen heaters

    International Nuclear Information System (INIS)

    Zasypin, I.M.

    2000-01-01

    The experimental data on the electric arc burning in hydrogen are presented. Empirical and semiempirical dependences for calculating the arc characteristics are derived. An engineering method of calculating plasma torches for hydrogen heating is proposed. A model of interaction of a hydrogen arc with a gas flow is outlined. The characteristics of plasma torches for heating hydrogen and hydrogen-bearing gases are described. (author)

  11. Hot testing of coke

    Energy Technology Data Exchange (ETDEWEB)

    Balon, I D

    1976-07-01

    Earlier investigations failed to take full account of the factors affecting coke behavior within the blast furnace. An apparatus was accordingly developed for testing coke, based on a cyclone furnace where the sample could be held in a flow of hot oxidizing gases, simulating conditions in the blast furnace hearth. The results are said to be suitable for comprehensive assessment of the coke, including abrasive strength and its rate of gasification in a flow of carbon dioxide. Coke of size 6-10 mm tested at 1,100/sup 0/C in an atmosphere of oxidizing gases close to those obtaining in the blast furnace hearth, indicated that destruction and total gasification of the coke occurs after 5 minutes for a weak coke and 8 minutes for strong coke, depending on the physico-chemical and physico-mechanical properties of the particular coke. When samples were treated for a fixed period (3 minutes), the amount of coke remaining, and the percentage over 6 mm varied between 22 and 40 and between 4 and 7 percent respectively.

  12. Hot accreting white dwarfs in the quasi-static approximation

    International Nuclear Information System (INIS)

    Iben, I. Jr.

    1982-01-01

    Properties of white dwarfs which are accreting hydrogen-rich matter at rates in the range 1.5 x 10 -9 to 2.5 x 10 -7 M/sub sun/ yr -1 are investigated in several approximations. Steady-burning models, in which matter is processed through nuclear-burning shells as rapidly as it is accreted, provide a framework for understanding the properties of models in which thermal pulses induced by hydrogen burning and helium burning are allowed to occur. In these latter models, the underlying carbon-oxygen core is chosen to be in a cycle-averaged steady state with regard to compressional heating and neutrino losses. Several of these models are evolved in the quasi-static approximation. Combining results obtained in the steady-burning approximation with those obtained in the quasi-static approximation, expressions are obtained for estimating, as functions of accretion rate and white dwarf mass, the thermal pulse recurrence period and the duration of hydrogen-burning phases. The time spent by an accreting model burning hydrogen as a large star of giant dimensions versus time spent burning hydrogen as a hot dwarf is also estimated as a function of model mass and accretion rate. Finally, suggestions for detecting observational counterparts of the theoretical models and suggestions for further theoretical investigations are offered. Subject headings: stars: accretion: stars: interiors: stars: novae: stars: symbiotic: stars: white dwarfs

  13. HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher

    2010-01-01

    We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

  14. Theory of hot particle stability

    International Nuclear Information System (INIS)

    Berk, H.L.; Wong, H.V.; Tsang, K.T.

    1986-10-01

    The investigation of stabilization of hot particle drift reversed systems to low frequency modes has been extended to arbitrary hot beta, β/sub H/ for systems that have unfavorable field line curvature. We consider steep profile equilibria where the thickness of the pressure drop, Δ, is less than plasma radius, r/sub p/. The analysis describes layer modes which have mΔ/r/sub p/ 2/3. When robust stability conditions are fulfilled, the hot particles will have their axial bounce frequency less than their grad-B drift frequency. This allows for a low bounce frequency expansion to describe the axial dependence of the magnetic compressional response

  15. Hot workability of aluminium alloys

    International Nuclear Information System (INIS)

    Yoo, Yeon Chul; Oh, Kyung Jin

    1986-01-01

    Hot Workability of aluminium alloys, 2024, 6061 and 7075, has been studied by hot torsion tests at temperatures from 320 to 515 deg C and at strain rates from 1.26 x 10 -3 to 5.71 x 10 -3 sec -1 . Hot working condition of these aluminium alloys was determined quantitatively from the constitutive equations obtained from flow stress curves in torsion. Experimental data of the logarith of the Zener-Hollomonn parameter showed good linear relationships to the logarith of sinh(ασ-bar)

  16. An investigation of a household size trigeneration running with hydrogen

    International Nuclear Information System (INIS)

    Wang, Yaodong; Huang, Ye; Chiremba, Elijah; Roskilly, Anthony P.; Hewitt, Neil; Ding, Yulong; Wu, Dawei; Yu, Hongdong; Chen, Xiangping; Li, Yapeng; Huang, Jincheng; Wang, Ruzhu; Wu, Jingyi; Xia, Zaizhong; Tan, Chunqing

    2011-01-01

    This study examined the performance and emission characteristics of a household size trigeneration based on a diesel engine generator fuelled with hydrogen comparing to that of single generation, cogeneration using ECLIPSE simulation software. In single generation simulation, the engine genset is used to produce electricity only and the heat from the engine is rejected to the atmosphere. In cogeneration and trigeneration, in addition to the electricity generated from the genset, the waste heat rejected from the hot exhaust gases and engine cooling system, is captured for domestic hot water supply using heat exchangers and hot water tank; and a part of the waste heat is used to drive absorption cooling in trigeneration. Comparisons have been made for the simulated results of these three modes of operation for hydrogen and diesel. The results prove that hydrogen is a potential energy vector in the future which is a key to meeting upcoming stringent greenhouse gases emissions. The study show that hydrogen has very good prospects to achieve a better or equal performance to conventional diesel fuel in terms of energetic performance, and a near zero carbon emission, depending on the life cycle analysis of the way the hydrogen is produced. The results also show enormous potential fuel savings and massive reductions in greenhouse gas emissions per unit of useful energy outputs with cogeneration and trigeneration compared with that of single generation.

  17. Why hydrogen; Pourquoi l'hydrogene?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-02-01

    The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

  18. A comparison of two atomic models for the radiative properties of dense hot low Z plasmas

    International Nuclear Information System (INIS)

    Minguez, E.; Sauvan, P.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Florido, R.; Martel, P.; Angelo, P.; Schott, R.; Philippe, F.; Leboucher-Dalimier, E.; Mancini, R.

    2003-01-01

    In this work, two different atomic models (ANALOP based on parametric potentials and IDEFIX based on the dicenter model) are used to calculate the opacities for bound-bound transitions in hot dense, low Z plasmas, and the results are compared to each other. In addition, the ANALOP code has been used to compute free-bound cross sections for hydrogen-like ions

  19. Effects of Dissociation/Recombination on the Day–Night Temperature Contrasts of Ultra-hot Jupiters

    Science.gov (United States)

    Komacek, Thaddeus D.; Tan, Xianyu

    2018-05-01

    Secondary eclipse observations of ultra-hot Jupiters have found evidence that hydrogen is dissociated on their daysides. Additionally, full-phase light curve observations of ultra-hot Jupiters show a smaller day-night emitted flux contrast than that expected from previous theory. Recently, it was proposed by Bell & Cowan (2018) that the heat intake to dissociate hydrogen and heat release due to recombination of dissociated hydrogen can affect the atmospheric circulation of ultra-hot Jupiters. In this work, we add cooling/heating due to dissociation/recombination into the analytic theory of Komacek & Showman (2016) and Zhang & Showman (2017) for the dayside-nightside temperature contrasts of hot Jupiters. We find that at high values of incident stellar flux, the day-night temperature contrast of ultra-hot Jupiters may decrease with increasing incident stellar flux due to dissociation/recombination, the opposite of that expected without including the effects of dissociation/recombination. We propose that a combination of a greater number of full-phase light curve observations of ultra-hot Jupiters and future General Circulation Models that include the effects of dissociation/recombination could determine in detail how the atmospheric circulation of ultra-hot Jupiters differs from that of cooler planets.

  20. Hydrogen fuel. Uses

    International Nuclear Information System (INIS)

    Darkrim-Lamari, F.; Malbrunot, P.

    2006-01-01

    Hydrogen is a very energetic fuel which can be used in combustion to generate heat and mechanical energy or which can be used to generate electricity and heat through an electrochemical reaction with oxygen. This article deals with the energy conversion, the availability and safety problems linked with the use of hydrogen, and with the socio-economical consequences of a generalized use of hydrogen: 1 - hydrogen energy conversion: hydrogen engines, aerospace applications, fuel cells (principle, different types, domains of application); 2 - hydrogen energy availability: transport and storage (gas pipelines, liquid hydrogen, adsorbed and absorbed hydrogen in solid materials), service stations; 3 - hazards and safety: flammability, explosibility, storage and transport safety, standards and regulations; 4 - hydrogen economy; 5 - conclusion. (J.S.)

  1. Hot Carrier Generation and Extraction of Plasmonic Alloy Nanoparticles.

    Science.gov (United States)

    Valenti, Marco; Venugopal, Anirudh; Tordera, Daniel; Jonsson, Magnus P; Biskos, George; Schmidt-Ott, Andreas; Smith, Wilson A

    2017-05-17

    The conversion of light to electrical and chemical energy has the potential to provide meaningful advances to many aspects of daily life, including the production of energy, water purification, and optical sensing. Recently, plasmonic nanoparticles (PNPs) have been increasingly used in artificial photosynthesis (e.g., water splitting) devices in order to extend the visible light utilization of semiconductors to light energies below their band gap. These nanoparticles absorb light and produce hot electrons and holes that can drive artificial photosynthesis reactions. For n-type semiconductor photoanodes decorated with PNPs, hot charge carriers are separated by a process called hot electron injection (HEI), where hot electrons with sufficient energy are transferred to the conduction band of the semiconductor. An important parameter that affects the HEI efficiency is the nanoparticle composition, since the hot electron energy is sensitive to the electronic band structure of the metal. Alloy PNPs are of particular importance for semiconductor/PNPs composites, because by changing the alloy composition their absorption spectra can be tuned to accurately extend the light absorption of the semiconductor. This work experimentally compares the HEI efficiency from Ag, Au, and Ag/Au alloy nanoparticles to TiO 2 photoanodes for the photoproduction of hydrogen. Alloy PNPs not only exhibit tunable absorption but can also improve the stability and electronic and catalytic properties of the pure metal PNPs. In this work, we find that the Ag/Au alloy PNPs extend the stability of Ag in water to larger applied potentials while, at the same time, increasing the interband threshold energy of Au. This increasing of the interband energy of Au suppresses the visible-light-induced interband excitations, favoring intraband excitations that result in higher hot electron energies and HEI efficiencies.

  2. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Kreutz, T.G.; Steinbugler, M. [Princeton Univ., NJ (United States)] [and others

    1996-10-01

    In this report the authors describe results from technical and economic assessments carried out during the past year with support from the USDOE Hydrogen R&D Program. (1) Assessment of technologies for small scale production of hydrogen from natural gas. Because of the cost and logistics of transporting and storing hydrogen, it may be preferable to produce hydrogen at the point of use from more readily available energy carriers such as natural gas or electricity. In this task the authors assess near term technologies for producing hydrogen from natural gas at small scale including steam reforming, partial oxidation and autothermal reforming. (2) Case study of developing a hydrogen vehicle refueling infrastructure in Southern California. Many analysts suggest that the first widespread use of hydrogen energy is likely to be in zero emission vehicles in Southern California. Several hundred thousand zero emission automobiles are projected for the Los Angeles Basin alone by 2010, if mandated levels are implemented. Assuming that hydrogen vehicles capture a significant fraction of this market, a large demand for hydrogen fuel could evolve over the next few decades. Refueling a large number of hydrogen vehicles poses significant challenges. In this task the authors assess near term options for producing and delivering gaseous hydrogen transportation fuel to users in Southern California including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and delivered to refueling stations via liquid hydrogen truck or small scale hydrogen gas pipeline, (2) hydrogen produced at the refueling station via small scale steam reforming of natural gas, (3) hydrogen produced via small scale electrolysis at the refueling station, and (4) hydrogen from low cost chemical industry sources (e.g. excess capacity in refineries which have recently upgraded their hydrogen production capacity, etc.).

  3. The decay of hot nuclei

    International Nuclear Information System (INIS)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs

  4. Mercury content in Hot Springs

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, R

    1974-01-01

    A method of determination of mercury in hot spring waters by flameless atomic absorption spectrophotometry is described. Further, the mercury content and the chemical behavior of the elementary mercury in hot springs are described. Sulfide and iodide ions interfered with the determination of mercury by the reduction-vapor phase technique. These interferences could, however, be minimized by the addition of potassium permanganate. Waters collected from 55 hot springs were found to contain up to 26.0 ppb mercury. High concentrations of mercury have been found in waters from Shimoburo Springs, Aomori (10.0 ppb), Osorezan Springs, Aomori (1.3 approximately 18.8 ppb), Gosyogake Springs, Akita (26.0 ppb), Manza Springs, Gunma (0.30 approximately 19.5 ppb) and Kusatu Springs, Gunma (1.70 approximately 4.50 ppb). These hot springs were acid waters containing a relatively high quantity of chloride or sulfate.

  5. Do scientists trace hot topics?

    Science.gov (United States)

    Wei, Tian; Li, Menghui; Wu, Chensheng; Yan, Xiao-Yong; Fan, Ying; Di, Zengru; Wu, Jinshan

    2013-01-01

    Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects.

  6. Hydrogen in metals

    CSIR Research Space (South Africa)

    Carter, TJ

    2001-04-01

    Full Text Available .J. Cartera,*, L.A. Cornishb aAdvanced Engineering & Testing Services, MATTEK, CSIR, Private Bag X28, Auckland Park 2006, South Africa bSchool of Process and Materials Engineering, University of the Witwatersrand, Private Bag 3, P.O. WITS 2050, South Africa... are contrasted, and an unusual case study of hydrogen embrittlement of an alloy steel is presented. 7 2001 Published by Elsevier Science Ltd. Keywords: Hydrogen; Hydrogen-assisted cracking; Hydrogen damage; Hydrogen embrittlement 1. Introduction Hydrogen suC128...

  7. Fuel Cell and Hydrogen Technologies Program | Hydrogen and Fuel Cells |

    Science.gov (United States)

    NREL Fuel Cell and Hydrogen Technologies Program Fuel Cell and Hydrogen Technologies Program Through its Fuel Cell and Hydrogen Technologies Program, NREL researches, develops, analyzes, and validates fuel cell and hydrogen production, delivery, and storage technologies for transportation

  8. Dynamics of hydrogen in hydrogenated amorphous silicon

    Indian Academy of Sciences (India)

    is mobile and can easily move through the material). Hydrogen diffuses ... The determination of the relationship of light-enhanced hydrogen motion to ... term is negligible, and using the thermodynamic relation given below f(c) = kBT .... device-applications problematic but the normal state can be recovered by a thermal an-.

  9. Handbook of hydrogen energy

    CERN Document Server

    Sherif, SA; Stefanakos, EK; Steinfeld, Aldo

    2014-01-01

    ""This book provides an excellent overview of the hydrogen economy and a thorough and comprehensive presentation of hydrogen production and storage methods.""-Scott E. Grasman, Rochester Institute of Technology, New York, USA

  10. Hydrogen production by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Chaudhuri Surabhi

    2005-12-01

    Full Text Available Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical, Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  11. Center for Hydrogen Storage.

    Science.gov (United States)

    2013-06-01

    The main goals of this project were to (1) Establish a Center for Hydrogen Storage Research at Delaware State University for the preparation and characterization of selected complex metal hydrides and the determination their suitability for hydrogen ...

  12. Stellar by Day, Planetary by Night: Atmospheres of Ultra-Hot Jupiters

    Science.gov (United States)

    Hensley, Kerry

    2018-06-01

    Move over, hot Jupiters theres an even stranger kind of giant planet in the universe! Ultra-hot Jupiters are so strongly irradiated that the molecules in their atmospheres split apart. What does this mean for heat transport on these planets?Atmospheres of Exotic PlanetsA diagram showing the orbit of an ultra-hot Jupiter and the longitudes at which dissociation and recombination occur. [Bell Cowan 2018]Similar to hot Jupiters, ultra-hot Jupiters are gas giants with atmospheres dominated by molecular hydrogen. What makes them interesting is that their dayside atmospheres are so hot that the molecules dissociate into individual hydrogen atoms more like the atmospheres of stars than planets.Because of the intense stellar irradiation, there is also an extreme temperature difference between the day and night sides of these planets potentially more than 1,000 K! As the stellar irradiation increases, the dayside atmosphere becomes hotter and hotter and the temperature difference between the day and night sides increases.When hot atomic hydrogen is transported into cooler regions (by winds, for instance), it recombines to form H2 molecules and heats the gas, effectively transporting heat from one location to another. This is similar to how the condensation of water redistributes heat in Earths atmosphere but what effect does this phenomenon have on the atmospheres of ultra-hot Jupiters?Maps of atmospheric temperature of molecular hydrogen dissociation fraction for three wind speeds. Click to enlarge. [Bell Cowan 2018]Modeling Heat RedistributionTaylor Bell and Nicolas Cowan (McGill University) used an energy-balance model to estimate the effects of H2 dissociation and recombination on heat transport in ultra-hot Jupiter atmospheres. In particular, they explored the redistribution of heat and how it affects the resultant phase curve the curve that describes the combination of reflected and thermally emitted light from the planet, observed as a function of its phase angle

  13. Nuclear electrolytic hydrogen

    International Nuclear Information System (INIS)

    Barnstaple, A.G.; Petrella, A.J.

    1982-05-01

    An extensive study of hydrogen supply has recently been carried out by Ontario Hydro which indicates that electrolytic hydrogen produced from nuclear electricity could offer the lowest cost option for any future large scale hydrogen supply in the Province of Ontario, Canada. This paper provides a synopsis of the Ontario Hydro study, a brief overview of the economic factors supporting the study conclusion and discussion of a number of issues concerning the supply of electrolytic hydrogen by electric power utilities

  14. Hydrogen Technologies Safety Guide

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burgess, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Buttner, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    The purpose of this guide is to provide basic background information on hydrogen technologies. It is intended to provide project developers, code officials, and other interested parties the background information to be able to put hydrogen safety in context. For example, code officials reviewing permit applications for hydrogen projects will get an understanding of the industrial history of hydrogen, basic safety concerns, and safety requirements.

  15. Hydrogen-metal systems

    International Nuclear Information System (INIS)

    Wenzl, H.; Springer, T.

    1976-01-01

    A survey is given on the alloys of metal crystals with hydrogen. The system niobium-hydrogen and its properties are especially dealt with: diffusion and heat of solution of hydrogen in the host crystal, phase diagram, coherent and incoherent phase separation, application of metal-hydrogen systems in technology. Furthermore, examples from research work in IFF (Institut fuer Festkoerperforschung) of the Nuclear Research Plant, Juelich, in the field of metal-H systems are given in summary form. (GSC) [de

  16. Uncertainty analysis for hot channel

    International Nuclear Information System (INIS)

    Panka, I.; Kereszturi, A.

    2006-01-01

    The fulfillment of the safety analysis acceptance criteria is usually evaluated by separate hot channel calculations using the results of neutronic or/and thermo hydraulic system calculations. In case of an ATWS event (inadvertent withdrawal of control assembly), according to the analysis, a number of fuel rods are experiencing DNB for a longer time and must be regarded as failed. Their number must be determined for a further evaluation of the radiological consequences. In the deterministic approach, the global power history must be multiplied by different hot channel factors (kx) taking into account the radial power peaking factors for each fuel pin. If DNB occurs it is necessary to perform a few number of hot channel calculations to determine the limiting kx leading just to DNB and fuel failure (the conservative DNBR limit is 1.33). Knowing the pin power distribution from the core design calculation, the number of failed fuel pins can be calculated. The above procedure can be performed by conservative assumptions (e.g. conservative input parameters in the hot channel calculations), as well. In case of hot channel uncertainty analysis, the relevant input parameters (k x, mass flow, inlet temperature of the coolant, pin average burnup, initial gap size, selection of power history influencing the gap conductance value) of hot channel calculations and the DNBR limit are varied considering the respective uncertainties. An uncertainty analysis methodology was elaborated combining the response surface method with the one sided tolerance limit method of Wilks. The results of deterministic and uncertainty hot channel calculations are compared regarding to the number of failed fuel rods, max. temperature of the clad surface and max. temperature of the fuel (Authors)

  17. Statistical hot spot analysis of reactor cores

    International Nuclear Information System (INIS)

    Schaefer, H.

    1974-05-01

    This report is an introduction into statistical hot spot analysis. After the definition of the term 'hot spot' a statistical analysis is outlined. The mathematical method is presented, especially the formula concerning the probability of no hot spots in a reactor core is evaluated. A discussion with the boundary conditions of a statistical hot spot analysis is given (technological limits, nominal situation, uncertainties). The application of the hot spot analysis to the linear power of pellets and the temperature rise in cooling channels is demonstrated with respect to the test zone of KNK II. Basic values, such as probability of no hot spots, hot spot potential, expected hot spot diagram and cumulative distribution function of hot spots, are discussed. It is shown, that the risk of hot channels can be dispersed equally over all subassemblies by an adequate choice of the nominal temperature distribution in the core

  18. Demonstration of Hydrogen Energy Network and Fuel Cells in Residential Homes

    International Nuclear Information System (INIS)

    Hirohisa Aki; Tetsuhiko Maeda; Itaru Tamura; Akeshi Kegasa; Yoshiro Ishikawa; Ichiro Sugimoto; Itaru Ishii

    2006-01-01

    The authors proposed the setting up of an energy interchange system by establishing energy networks of electricity, hot water, and hydrogen in residential homes. In such networks, some homes are equipped with fuel cell stacks, fuel processors, hydrogen storage devices, and large storage tanks for hot water. The energy network enables the flexible operation of the fuel cell stacks and fuel processors. A demonstration project has been planned in existing residential homes to evaluate the proposal. The demonstration will be presented in a small apartment building. The building will be renovated and will be equipped with a hydrogen production facility, a hydrogen interchange pipe, and fuel cell stacks with a heat recovery device. The energy flow process from hydrogen production to consumption in the homes will be demonstrated. This paper presents the proposed energy interchange system and demonstration project. (authors)

  19. Hydrogenation of passivated contacts

    Energy Technology Data Exchange (ETDEWEB)

    Nemeth, William; Yuan, Hao-Chih; LaSalvia, Vincenzo; Stradins, Pauls; Page, Matthew R.

    2018-03-06

    Methods of hydrogenation of passivated contacts using materials having hydrogen impurities are provided. An example method includes applying, to a passivated contact, a layer of a material, the material containing hydrogen impurities. The method further includes subsequently annealing the material and subsequently removing the material from the passivated contact.

  20. Single-collision studies of hot atom energy transfer and chemical reaction

    International Nuclear Information System (INIS)

    Valentini, J.J.

    1991-01-01

    This report discusses research in the collision dynamics of translationally hot atoms, with funding with DOE for the project ''Single-Collision Studies of Hot Atom Energy Transfer and Chemical Reaction,'' Grant Number DE-FG03-85ER13453. The work reported here was done during the period September 9, 1988 through October 31, 1991. During this period this DOE-funded work has been focused on several different efforts: (1) experimental studies of the state-to-state dynamics of the H + RH → H 2 R reactions where RH is CH 4 , C 2 H 6 , or C 3 H 8 , (2) theoretical (quasiclassical trajectory) studies of hot hydrogen atom collision dynamics, (3) the development of photochemical sources of translationally hot molecular free radicals and characterization of the high resolution CARS spectroscopy of molecular free radicals, (4) the implementation of stimulated Raman excitation (SRE) techniques for the preparation of vibrationally state-selected molecular reactants

  1. Hot dry rock heat mining

    International Nuclear Information System (INIS)

    Duchane, D.V.

    1992-01-01

    Geothermal energy utilizing fluids from natural sources is currently exploited on a commercial scale at sites around the world. A much greater geothermal resource exists, however, in the form of hot rock at depth which is essentially dry. This hot dry rock (HDR) resource is found almost everywhere, but the depth at which usefully high temperatures are reached varies from place to place. The technology to mine the thermal energy from HDR has been under development for a number of years. Using techniques adapted from the petroleum industry, water is pumped at high pressure down an injection well to a region of usefully hot rock. The pressure forces open natural joints to form a reservoir consisting of a small amount of water dispensed in a large volume of hot rock. This reservoir is tapped by second well located at some distance from the first, and the heated water is brought to the surface where its thermal energy is extracted. The same water is then recirculated to mine more heat. Economic studies have indicated that it may be possible to produce electricity at competitive prices today in regions where hot rock is found relatively close to the surface

  2. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  3. Solar Hydrogen Reaching Maturity

    Directory of Open Access Journals (Sweden)

    Rongé Jan

    2015-09-01

    Full Text Available Increasingly vast research efforts are devoted to the development of materials and processes for solar hydrogen production by light-driven dissociation of water into oxygen and hydrogen. Storage of solar energy in chemical bonds resolves the issues associated with the intermittent nature of sunlight, by decoupling energy generation and consumption. This paper investigates recent advances and prospects in solar hydrogen processes that are reaching market readiness. Future energy scenarios involving solar hydrogen are proposed and a case is made for systems producing hydrogen from water vapor present in air, supported by advanced modeling.

  4. Canada's hydrogen energy sector

    International Nuclear Information System (INIS)

    Kimmel, T.B.

    2009-01-01

    Canada produces the most hydrogen per capita of any Organization of Economic Cooperation and Development (OECD) country. The majority of this hydrogen is produced by steam methane reforming for industrial use (predominantly oil upgrading and fertilizer production). Canada also has a world leading hydrogen and fuel cell sector. This sector is seeking new methods for making hydrogen for its future energy needs. The paper will discuss Canada's hydrogen and fuel cell sector in the context of its capabilities, its demonstration and commercialization activities and its stature on the world stage. (author)

  5. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste......-hoc and real time electrical signal of the fuel cell water balance by employing hot wire anemometry. The hot wire sensor is placed into a binary mixture of hydrogen and water vapour, and the voltage signal received gives valuable insight into heat and mass transfer phenomena in a PEMFC. A central question...

  6. Rigorous assessment and integration of the sequence and structure based features to predict hot spots

    Directory of Open Access Journals (Sweden)

    Wang Yong

    2011-07-01

    Full Text Available Abstract Background Systematic mutagenesis studies have shown that only a few interface residues termed hot spots contribute significantly to the binding free energy of protein-protein interactions. Therefore, hot spots prediction becomes increasingly important for well understanding the essence of proteins interactions and helping narrow down the search space for drug design. Currently many computational methods have been developed by proposing different features. However comparative assessment of these features and furthermore effective and accurate methods are still in pressing need. Results In this study, we first comprehensively collect the features to discriminate hot spots and non-hot spots and analyze their distributions. We find that hot spots have lower relASA and larger relative change in ASA, suggesting hot spots tend to be protected from bulk solvent. In addition, hot spots have more contacts including hydrogen bonds, salt bridges, and atomic contacts, which favor complexes formation. Interestingly, we find that conservation score and sequence entropy are not significantly different between hot spots and non-hot spots in Ab+ dataset (all complexes. While in Ab- dataset (antigen-antibody complexes are excluded, there are significant differences in two features between hot pots and non-hot spots. Secondly, we explore the predictive ability for each feature and the combinations of features by support vector machines (SVMs. The results indicate that sequence-based feature outperforms other combinations of features with reasonable accuracy, with a precision of 0.69, a recall of 0.68, an F1 score of 0.68, and an AUC of 0.68 on independent test set. Compared with other machine learning methods and two energy-based approaches, our approach achieves the best performance. Moreover, we demonstrate the applicability of our method to predict hot spots of two protein complexes. Conclusion Experimental results show that support vector machine

  7. Rigorous assessment and integration of the sequence and structure based features to predict hot spots

    Science.gov (United States)

    2011-01-01

    Background Systematic mutagenesis studies have shown that only a few interface residues termed hot spots contribute significantly to the binding free energy of protein-protein interactions. Therefore, hot spots prediction becomes increasingly important for well understanding the essence of proteins interactions and helping narrow down the search space for drug design. Currently many computational methods have been developed by proposing different features. However comparative assessment of these features and furthermore effective and accurate methods are still in pressing need. Results In this study, we first comprehensively collect the features to discriminate hot spots and non-hot spots and analyze their distributions. We find that hot spots have lower relASA and larger relative change in ASA, suggesting hot spots tend to be protected from bulk solvent. In addition, hot spots have more contacts including hydrogen bonds, salt bridges, and atomic contacts, which favor complexes formation. Interestingly, we find that conservation score and sequence entropy are not significantly different between hot spots and non-hot spots in Ab+ dataset (all complexes). While in Ab- dataset (antigen-antibody complexes are excluded), there are significant differences in two features between hot pots and non-hot spots. Secondly, we explore the predictive ability for each feature and the combinations of features by support vector machines (SVMs). The results indicate that sequence-based feature outperforms other combinations of features with reasonable accuracy, with a precision of 0.69, a recall of 0.68, an F1 score of 0.68, and an AUC of 0.68 on independent test set. Compared with other machine learning methods and two energy-based approaches, our approach achieves the best performance. Moreover, we demonstrate the applicability of our method to predict hot spots of two protein complexes. Conclusion Experimental results show that support vector machine classifiers are quite

  8. Hot Jupiters around M dwarfs

    Directory of Open Access Journals (Sweden)

    Murgas F.

    2013-04-01

    Full Text Available The WFCAM Transit Survey (WTS is a near-infrared transit survey running on the United Kingdom Infrared Telescope (UKIRT. We conduct Monte Carlo transit injection and detection simulations for short period (<10 day Jupiter-sized planets to characterize the sensitivity of the survey. We investigate the recovery rate as a function of period and magnitude in 2 hypothetical star-planet cases: M0–2 + hot Jupiter, M2–4 + hot Jupiter. We find that the WTS lightcurves are very sensitive to the presence of Jupiter-sized short-period transiting planets around M dwarfs. The non-detection of a hot-Jupiter around an M dwarf by the WFCAM Transit Survey allows us to place a firm upper limit of 1.9 per cent (at 95 per cent confidence on the planet occurrence rate.

  9. Promethus Hot Leg Piping Concept

    International Nuclear Information System (INIS)

    AM Girbik; PA Dilorenzo

    2006-01-01

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept

  10. Hot-pressing steatite bodies

    International Nuclear Information System (INIS)

    Aparicio Arroyo, E.

    1967-01-01

    Requirements for some special nuclear engineering ceramic shapes are: big size, impervious, dimensional accuracy and good mechanical and dielectric properties. Limitations of te conventional methods and advantages of te hot pressing techniques for the manufacturing of these shapes are discussed. Hot pressing characteristics of a certain steatite powder are studied. Occurrence of an optimum densification temperature just above the tale decomposition range is found. Experimental data show that the height/diameter ratio of the specimen has no effect on the sintering conditions. Increasing darkness from the graphite mould is detected above the optimum temperature. The hot-pressed steatite is compared with a fired dry-pressed sample of the same composition. (Author) 13 refs

  11. Hydrogen energy assessment

    Energy Technology Data Exchange (ETDEWEB)

    Salzano, F J; Braun, C [eds.

    1977-09-01

    The purpose of this assessment is to define the near term and long term prospects for the use of hydrogen as an energy delivery medium. Possible applications of hydrogen are defined along with the associated technologies required for implementation. A major focus in the near term is on industrial uses of hydrogen for special applications. The major source of hydrogen in the near term is expected to be from coal, with hydrogen from electric sources supplying a smaller fraction. A number of potential applications for hydrogen in the long term are identified and the level of demand estimated. The results of a cost benefit study for R and D work on coal gasification to hydrogen and electrolytic production of hydrogen are presented in order to aid in defining approximate levels of R and D funding. A considerable amount of data is presented on the cost of producing hydrogen from various energy resources. A key conclusion of the study is that in time hydrogen is likely to play a role in the energy system; however, hydrogen is not yet competitive for most applications when compared to the cost of energy from petroleum and natural gas.

  12. Hydrogen energy for beginners

    CERN Document Server

    2013-01-01

    This book highlights the outstanding role of hydrogen in energy processes, where it is the most functional element due to its unique peculiarities that are highlighted and emphasized in the book. The first half of the book covers the great natural hydrogen processes in biology, chemistry, and physics, showing that hydrogen is a trend that can unite all natural sciences. The second half of the book is devoted to the technological hydrogen processes that are under research and development with the aim to create the infrastructure for hydrogen energetics. The book describes the main features of hydrogen that make it inalienable player in processes such as fusion, photosynthesis, and metabolism. It also covers the methods of hydrogen production and storage, highlighting at the same time the exclusive importance of nanotechnologies in those processes.

  13. Hydrogen peroxide safety issues

    International Nuclear Information System (INIS)

    Conner, W.V.

    1993-01-01

    A literature survey was conducted to review the safety issues involved in handling hydrogen peroxide solutions. Most of the information found in the literature is not directly applicable to conditions at the Rocky Flats Plant, but one report describes experimental work conducted previously at Rocky Flats to determine decomposition reaction-rate constants for hydrogen peroxide solutions. Data from this report were used to calculate decomposition half-life times for hydrogen peroxide in solutions containing several decomposition catalysts. The information developed from this survey indicates that hydrogen peroxide will undergo both homogeneous and heterogeneous decomposition. The rate of decomposition is affected by temperature and the presence of catalytic agents. Decomposition of hydrogen peroxide is catalyzed by alkalies, strong acids, platinum group and transition metals, and dissolved salts of transition metals. Depending upon conditions, the consequence of a hydrogen peroxide decomposition can range from slow evolution of oxygen gas to a vapor, phase detonation of hydrogen peroxide vapors

  14. Hydrogen and its challenges

    International Nuclear Information System (INIS)

    Schal, M.

    2008-01-01

    The future of hydrogen as a universal fuel is in jeopardy unless we are able to produce it through an environment-friendly way and at a competitive cost. Today almost all the hydrogen used in the world is produced by steam reforming of natural gas. This process releases 8 tonnes of CO 2 per tonne of hydrogen produced. Other means of producing hydrogen are the hydrolysis, the very high temperature hydrolysis, and the direct chemical dissociation of water, these processes are greener than steam reforming but less efficient. About one hundred buses in the world operate on fuel cells fed by hydrogen, but it appears that the first industrial use of hydrogen at great scale will be for the local generation of electricity. Globally the annual budget for research concerning hydrogen is 4.4 milliard (10 9 ) euros worldwide. (A.C.)

  15. Archaeal Nitrification in Hot Springs

    Science.gov (United States)

    Richter, A.; Daims, H.; Reigstad, L.; Wanek, W.; Wagner, M.; Schleper, C.

    2006-12-01

    Biological nitrification, i.e. the aerobic conversion of ammonia to nitrate via nitrite, is a major component of the global nitrogen cycle. Until recently, it was thought that the ability to aerobically oxidize ammonia was confined to bacteria of the phylum Proteobacteria. However, it has recently been shown that Archaea of the phylum Crenarchaeota are also capable of ammonia oxidation. As many Crenarchaeota are thermophilic or hyperthermophilic, and at least some of them are capable of ammonia oxidation we speculated on the existence of (hyper)thermophilic ammonia-oxidizing archaea (AOA). Using PCR primers specifically targeting the archaeal ammonia monooxygenase (amoA) gene, we were indeed able to confirm the presence of such organisms in several hot springs in Reykjadalur, Iceland. These hot springs exhibited temperatures well above 80 °C and pH values ranging from 2.0 to 4.5. To proof that nitrification actually took place under these extreme conditions, we measured gross nitrification rates by the isotope pool dilution method; we added 15N-labelled nitrate to the mud and followed the dilution of the label by nitrate production from ammonium either in situ (incubation in the hot spring) or under controlled conditions in the laboratory (at 80 °C). The nitrification rates in the hot springs ranged from 0.79 to 2.22 mg nitrate-N per L of mud and day. Controls, in which microorganisms were killed before the incubations, demonstrated that the nitrification was of biological origin. Addition of ammonium increased the gross nitrification rate approximately 3-fold, indicating that the nitrification was ammonium limited under the conditions used. Collectively, our study provides evidence that (1) AOA are present in hot springs and (2) that they are actively nitrifying. These findings have major implications for our understanding of nitrogen cycling of hot environments.

  16. Monopole transitions in hot nuclei

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1994-01-01

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs

  17. Monopole transitions in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

  18. Hot atom chemistry of sulphur

    International Nuclear Information System (INIS)

    Todorovski, D. S.; Koleva, D. P.

    1982-01-01

    An attempt to cover all papers dealing with the hot atom chemistry of sulpphur is made. Publications which: a) only touch the problem, b) contain some data, indirectly connected with sulphur hot atom chemistry, c) deal with 35 S-production from a chloride matrix, are included as well. The author's name and literature source are given in the original language, transcribed, when it is necessary, in latine. A number of primery and secondary documents have been used including Chemical Abstracts, INIS Atomindex, the bibliographies of A. Siuda and J.-P. Adloff for 1973 - 77, etc. (authors)

  19. Construction of concrete hot cells

    International Nuclear Information System (INIS)

    1981-12-01

    The standard is to be applied to rooms (hot cells) which are enclosed by a concrete shield and in which radioactive material is handled by remote control. The rooms may be in facilities for experimental purposes (e.g. development of fuel elements and materials or of chemical processes) or in facilities for production purposes (e.g. reprocessing of nuclear fuel or treatment of radioactive wastes). The standard is to give a design hasis for concrete hot cells and their installations which is to be applied by designers, constructors, future users and competent authorities as well as independent experts. (orig.) [de

  20. Construction of concrete hot cells

    International Nuclear Information System (INIS)

    1980-09-01

    The standard is to be applied to rooms (hot cells) which are enclosed by a concrete shield and in which radioactive material is handled by remote control. The rooms may be in facilities for experimental purposes (e.g. development of fuel elements and materials or of chemical processes) or in facilities for production purposes (e.g. reprocessing of nuclear fuel or treatment of radioactive wastes). The standard is to give a design basis for concrete hot cells and their installations which is to be applied by designers, constructors, future users and competent authorities as well as independent experts. (orig.) [de

  1. Hot-cell verification facility

    International Nuclear Information System (INIS)

    Eschenbaum, R.A.

    1981-01-01

    The Hot Cell Verification Facility (HCVF) was established as the test facility for the Fuels and Materials Examination Facility (FMEF) examination equipment. HCVF provides a prototypic hot cell environment to check the equipment for functional and remote operation. It also provides actual hands-on training for future FMEF Operators. In its two years of operation, HCVF has already provided data to make significant changes in items prior to final fabrication. It will also shorten the startup time in FMEF since the examination equipment will have been debugged and operated in HCVF

  2. Determination of activation energy of hydrogen diffusion in Zr-2.5%Nb alloy

    International Nuclear Information System (INIS)

    Chandra, Komal; Kulkarni, A.S.; Ramanjaneyulu, P.S.; Yadav, C.S.; Saxena, M.K.; Tomar, B.S.; Ramakumar, K.L.; Sunil, Sourav; Singh, R.N.

    2013-01-01

    The present paper describes the study on the determination of diffusion coefficient of hydrogen in Zr-2.5%Nb alloy. Hydrogen was charged on Zr-2.5% Nb alloy electrolytically. After annealing at required temperature, hydrogen concentration at various depths from the charged end was determined employing hot vacuum extraction-quadrupole mass spectrometer (HVE-QMS). The depth profile was used to obtain the diffusion coefficient employing Fick's second law of diffusion. From the Arrhenius relation between diffusion coefficient and temperature, activation energy of hydrogen diffusion was calculated. (author)

  3. Sustainable Energy - Without the hot air

    Science.gov (United States)

    MacIsaac, Dan

    2009-11-01

    Reader John Roeder writes about a website associated with David MacKay's book Sustainable Energy-Without the hot air. The book is a freely downloadable PDF (or purchasable) book describing an analysis detailing a low-carbon renewable energy transformation route for a large, modern first world industrial country (the United Kingdom). Written for the layman, the work uses vernacular language, e.g., energy consumption and production in a series of bar charts detailing the impacts of necessary strategies such as population reduction, lifestyle changes, and technology changes. MacKay notes that most reasonable plans have large nuclear and ``clean coal'' or other carbon capture components, lots of pumped heat, wind, and much efficiency improvement. He debunks some sacred cows (roof-mounted micro-turbines; hydrogen-powered cars) while pointing out simple effective technologies such as roof-mounted solar water heaters. Similar modest changes in the U.S. (painting roofs white in the southern half of the country) have strong impacts. MacKay claims that he ``doesn't advocate any particular plan or technology,'' but ``tells you how many bricks are in the lego box, and how big each brick is'' so readers can start making planning decisions.

  4. Hot conditioning equipment conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  5. Hot conditioning equipment conceptual design report

    International Nuclear Information System (INIS)

    Bradshaw, F.W.

    1996-01-01

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage

  6. Formation of Neutral Disk-Like Zone Around the Active Hot Stars in Symbiotic Binaries

    Directory of Open Access Journals (Sweden)

    Cariková Z.

    2012-06-01

    Full Text Available In this contribution we present the ionization structure in the enhanced wind from the hot star in symbiotic binaries during active phases. Rotation of the hot star leads to the compression of the outflowing material towards its equatorial plane. As a result, a neutral disk-like zone around the active hot star near the orbital plane is created. We modeled the compression of the wind and calculated the neutral disk-like zone in the enhanced wind from the hot star using the equation of the photoionization equilibrium. the presence of such neutral disk-like zones was also suggested on the basis of the modeling the spectral energy distribution of symbiotic binaries. We confront the calculated ionization structures in the enhanced wind from the hot star with the observations. the calculated column density of the neutral hydrogen atoms in the neutral disk-like zone and the emission measure of the ionized part of the wind from the hot star are in a good agreement with the quantities derived from observations during active phases. the presence of such neutral disk-like zones is transient, being connected with the active phases of symbiotic binaries. During quiescent phases, such neutral disk-like zones cannot be created because of insufficient mass-loss rate from the hot star.

  7. Understanding the reaction between muonium atoms and hydrogen molecules: zero point energy, tunnelling, and vibrational adiabaticity

    Science.gov (United States)

    Aldegunde, J.; Jambrina, P. G.; García, E.; Herrero, V. J.; Sáez-Rábanos, V.; Aoiz, F. J.

    2013-11-01

    The advent of very precise measurements of rate coefficients in reactions of muonium (Mu), the lightest hydrogen isotope, with H2 in its ground and first vibrational state and of kinetic isotope effects with respect to heavier isotopes has triggered a renewed interests in the field of muonic chemistry. The aim of the present article is to review the most recent results about the dynamics and mechanism of the reaction Mu+H2 to shed light on the importance of quantum effects such as tunnelling, the preservation of the zero point energy, and the vibrational adiabaticity. In addition to accurate quantum mechanical (QM) calculations, quasiclassical trajectories (QCT) have been run in order to check the reliability of this method for this isotopic variant. It has been found that the reaction with H2(v=0) is dominated by the high zero point energy (ZPE) of the products and that tunnelling is largely irrelevant. Accordingly, both QCT calculations that preserve the products' ZPE as well as those based on the Ring Polymer Molecular Dynamics methodology can reproduce the QM rate coefficients. However, when the hydrogen molecule is vibrationally excited, QCT calculations fail completely in the prediction of the huge vibrational enhancement of the reactivity. This failure is attributed to tunnelling, which plays a decisive role breaking the vibrational adiabaticity when v=1. By means of the analysis of the results, it can be concluded that the tunnelling takes place through the ν1=1 collinear barrier. Somehow, the tunnelling that is missing in the Mu+H2(v=0) reaction is found in Mu+H2(v=1).

  8. A radial velocity survey of extremely hydrogen-deficient stars

    International Nuclear Information System (INIS)

    Jeffery, C.S.; Kiel Univ.; Drilling, J.S.; Heber, U.

    1987-01-01

    A radial velocity survey of hot extremely hydrogen-deficient stars has been carried out in order to search for possible binaries. The survey found three stars to have large velocity variations. Of these, two are known hydrogen-deficient binaries and one, HDE 320156 (= LSS 4300), is a suspected binary. HDE 320156 (= LSS 4300) is therefore confirmed to be a single-lined spectroscopic hydrogen-deficient binary. The hydrogen-deficient binary stars all show weak C-lines. The remaining stars in the sample are C-strong extreme-helium (EHe) stars and did not show large-amplitude velocity variations. Small-amplitude radial velocity variations known to be present amongst the EHe stars are largely undetected. Evidence for variability is, however, present in the known variable V2076 Oph (HD 160641) and in LS IV - 1 0 2 with amplitudes between 10 and 20 km s -1 . (author)

  9. Hydrogen - From hydrogen to energy production

    International Nuclear Information System (INIS)

    Klotz, Gregory

    2005-01-01

    More than a century ago, Jules Verne wrote in 'The Mysterious Island' that water would one day be employed as fuel: 'Hydrogen and oxygen, which constitute it, used singly or together, will furnish an inexhaustible source of heat and light'. Today, the 'water motor' is not entirely the dream of a writer. Fiction is about to become fact thanks to hydrogen, which can be produced from water and when burned in air itself produces water. Hydrogen is now at the heart of international research. So why do we have such great expectations of hydrogen? 'Hydrogen as an energy system is now a major challenge, both scientifically and from an environmental and economic point of view'. Dominated as it is by fossil fuels (oil, gas and coal), our current energy system has left a dual threat hovering over our environment, exposing the planet to the exhaustion of its natural reserves and contributing to the greenhouse effect. If we want sustainable development for future generations, it is becoming necessary to diversify our methods of producing energy. Hydrogen is not, of course, a source of energy, because first it has to be produced. But it has the twofold advantage of being both inexhaustible and non-polluting. So in the future, it should have a very important role to play. (author)

  10. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  11. Ultrafine hydrogen storage powders

    Science.gov (United States)

    Anderson, Iver E.; Ellis, Timothy W.; Pecharsky, Vitalij K.; Ting, Jason; Terpstra, Robert; Bowman, Robert C.; Witham, Charles K.; Fultz, Brent T.; Bugga, Ratnakumar V.

    2000-06-13

    A method of making hydrogen storage powder resistant to fracture in service involves forming a melt having the appropriate composition for the hydrogen storage material, such, for example, LaNi.sub.5 and other AB.sub.5 type materials and AB.sub.5+x materials, where x is from about -2.5 to about +2.5, including x=0, and the melt is gas atomized under conditions of melt temperature and atomizing gas pressure to form generally spherical powder particles. The hydrogen storage powder exhibits improved chemcial homogeneity as a result of rapid solidfication from the melt and small particle size that is more resistant to microcracking during hydrogen absorption/desorption cycling. A hydrogen storage component, such as an electrode for a battery or electrochemical fuel cell, made from the gas atomized hydrogen storage material is resistant to hydrogen degradation upon hydrogen absorption/desorption that occurs for example, during charging/discharging of a battery. Such hydrogen storage components can be made by consolidating and optionally sintering the gas atomized hydrogen storage powder or alternately by shaping the gas atomized powder and a suitable binder to a desired configuration in a mold or die.

  12. Canadian hydrogen safety program

    International Nuclear Information System (INIS)

    MacIntyre, I.; Tchouvelev, A.V.; Hay, D.R.; Wong, J.; Grant, J.; Benard, P.

    2007-01-01

    The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes and Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety. (author)

  13. High density hydrogen research

    International Nuclear Information System (INIS)

    Hawke, R.S.

    1977-01-01

    The interest in the properties of very dense hydrogen is prompted by its abundance in Saturn and Jupiter and its importance in laser fusion studies. Furthermore, it has been proposed that the metallic form of hydrogen may be a superconductor at relatively high temperatures and/or exist in a metastable phase at ambient pressure. For ten years or more, laboratories have been developing the techniques to study hydrogen in the megabar region (1 megabar = 100 GPa). Three major approaches to study dense hydrogen experimentally have been used, static presses, shockwave compression, and magnetic compression. Static tchniques have crossed the megabar threshold in stiff materials but have not yet been convincingly successful in very compressible hydrogen. Single and double shockwave techniques have improved the precision of the pressure, volume, temperature Equation of State (EOS) of molecular hydrogen (deuterium) up to near 1 Mbar. Multiple shockwave and magnetic techniques have compressed hydrogen to several megabars and densities in the range of the metallic phase. The net result is that hydrogen becomes conducting at a pressure between 2 and 4 megabars. Hence, the possibility of making a significant amount of hydrogen into a metal in a static press remains a formidable challenge. The success of such experiments will hopefully answer the questions about hydrogen's metallic vs. conducting molecular phase, superconductivity, and metastability. 4 figures, 15 references

  14. The energy carrier hydrogen

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The potential of hydrogen to be used as a clean fuel for the production of heat and power, as well as for the propulsion of aeroplanes and vehicles, is described, in particular for Germany. First, attention is paid to the application of hydrogen as a basic material for the (petro)chemical industry, as an indirect energy source for (petro)chemical processes, and as a direct energy source for several purposes. Than the importance of hydrogen as an energy carrier in a large-scale application of renewable energy sources is discussed. Next an overview is given of new and old hydrogen production techniques from fossil fuels, biomass, or the electrolysis of water. Energetic applications of hydrogen in the transportation sector and the production of electric power and heat are mentioned. Brief descriptions are given of techniques to store hydrogen safely. Finally attention is paid to hydrogen research in Germany. Two hydrogen projects, in which Germany participates, are briefly dealt with: the Euro-Quebec project (production of hydrogen by means of hydropower), and the HYSOLAR project (hydrogen production by means of solar energy). 18 figs., 1 tab., 7 refs

  15. Hydrogen energy applications

    International Nuclear Information System (INIS)

    Okken, P.A.

    1992-10-01

    For the Energy and Material consumption Scenarios (EMS), by which emission reduction of CO 2 and other greenhouse gases can be calculated, calculations are executed by means of the MARKAL model (MARket ALlocation, a process-oriented dynamic linear programming model to minimize the costs of the energy system) for the Netherlands energy economy in the period 2000-2040, using a variable CO 2 emission limit. The results of these calculations are published in a separate report (ECN-C--92-066). The use of hydrogen can play an important part in the above-mentioned period. An overview of several options to produce or use hydrogen is given and added to the MARKAL model. In this report techno-economical data and estimates were compiled for several H 2 -application options, which subsequently also are added to the MARKAL model. After a brief chapter on hydrogen and the impact on the reduction of CO 2 emission attention is paid to stationary and mobile applications. The stationary options concern the mixing of natural gas with 10% hydrogen, a 100% substitution of natural gas by hydrogen, the use of a direct steam generator (combustion of hydrogen by means of pure oxygen, followed by steam injection to produce steam), and the use of fuel cells. The mobile options concern the use of hydrogen in the transportation sector. In brief, attention is paid to a hydrogen passenger car with an Otto engine, and a hydrogen passenger car with a fuel cell, a hybrid (metal)-hydride car, a hydrogen truck, a truck with a methanol fuel cell, a hydrogen bus, an inland canal boat with a hydrogen fuel cell, and finally a hydrogen airplane. 2 figs., 15 tabs., 1 app., 26 refs

  16. Mechanism of Corrosion of Activated Aluminum Particles by Hot Water

    International Nuclear Information System (INIS)

    Razavi-Tousi, S.S.; Szpunar, J.A.

    2014-01-01

    Mechanism of corrosion in aluminum particles by hot water treatment for hydrogen generation is evaluated. The aluminum powder was activated by ball milling for different durations, which modified size and microstructure of the particles. Open circuit potential test was carried out to elucidate different stages of the reaction. Tafel test was used to explain the effect of ball milling and growth of hydroxide layer on corrosion of the particles. Surface, cross section and thickness of the grown hydroxide on the aluminum particles were studied in a scanning electron microscope. The corrosion potential of the aluminum powders depends on microstructure of the aluminum particles, growth of the hydroxide layer and a change in pH because of cathodic reactions. The hydrogen production test showed that a deformed microstructure and smaller particle size accelerates the corrosion rate of aluminum by hot water, the effect of the deformed microstructure being more significant at the beginning of the reaction. Effect of growth of the hydroxide layer on corrosion mechanism is discussed

  17. Atomic hydrogen cleaning of EUV multilayer optics

    Science.gov (United States)

    Graham, Samuel, Jr.; Steinhaus, Charles A.; Clift, W. Miles; Klebanoff, Leonard E.; Bajt, Sasa

    2003-06-01

    Recent studies have been conducted to investigate the use of atomic hydrogen as an in-situ contamination removal method for EUV optics. In these experiments, a commercial source was used to produce atomic hydrogen by thermal dissociation of molecular hydrogen using a hot filament. Samples for these experiments consisted of silicon wafers coated with sputtered carbon, Mo/Si optics with EUV-induced carbon, and bare Si-capped and Ru-B4C-capped Mo/Si optics. Samples were exposed to an atomic hydrogen source at a distance of 200 - 500 mm downstream and angles between 0-90° with respect to the source. Carbon removal rates and optic oxidation rates were measured using Auger electron spectroscopy depth profiling. In addition, at-wavelength peak reflectance (13.4 nm) was measured using the EUV reflectometer at the Advanced Light Source. Data from these experiments show carbon removal rates up to 20 Å/hr for sputtered carbon and 40 Å/hr for EUV deposited carbon at a distance of 200 mm downstream. The cleaning rate was also observed to be a strong function of distance and angular position. Experiments have also shown that the carbon etch rate can be increased by a factor of 4 by channeling atomic hydrogen through quartz tubes in order to direct the atomic hydrogen to the optic surface. Atomic hydrogen exposures of bare optic samples show a small risk in reflectivity degradation after extended periods. Extended exposures (up to 20 hours) of bare Si-capped Mo/Si optics show a 1.2% loss (absolute) in reflectivity while the Ru-B4C-capped Mo/Si optics show a loss on the order of 0.5%. In order to investigate the source of this reflectivity degradation, optic samples were exposed to atomic deuterium and analyzed using low energy ion scattering direct recoil spectroscopy to determine any reactions of the hydrogen with the multilayer stack. Overall, the results show that the risk of over-etching with atomic hydrogen is much less than previous studies using RF discharge cleaning

  18. Solar Technician Program Blows Hot

    Science.gov (United States)

    Ziegler, Peg Moran

    1977-01-01

    A training program for solar heating technicians was initiated at Sonoma State College's School of Environmental Studies for CETA applicants. Among the projects designed and built were a solar alternative energy center, a solar hot water system, and a solar greenhouse. (MF)

  19. The design of hot laboratories

    International Nuclear Information System (INIS)

    1976-01-01

    The need for specialized laboratories to handle radioactive substances of high activity has increased greatly due to the expansion of the nuclear power industry and the widespread use of radioisotopes in scientific research and technology. Such laboratories, which are called hot laboratories, are specially designed and equipped to handle radioactive materials of high activity, including plutonium and transplutonium elements. The handling of plutonium and transplutonium elements presents special radiation-protection and safety problems because of their high specific activity and high radiotoxicity. Therefore, the planning, design, construction and operation of hot laboratories must meet the stringent safety, containment, ventilation, shielding, criticality control and fire-protection requirements. The IAEA has published two manuals in its Safety Series, one on the safety aspects of design and equipment of hot laboratories (SS No.30) and the other on the safe handling of plutonium (SS No.39). The purpose of the symposium in Otaniemi was to collect information on recent developments in the safety features of hot laboratories and to review the present state of knowledge. A number of new developments have taken place as the result of growing sophistication in the philosophy of radiation protection as given in the ICRP recommendations (Report No.22) and in the Agency's basic safety standards (No.9). The topics discussed were safety features of planning and design, air cleaning, transfer and transport systems, criticality control, fire protection, radiological protection, waste management, administrative arrangements and operating experience

  20. Interfaces in hot gauge theory

    CERN Document Server

    Bronoff, S.

    1996-01-01

    The string tension at low T and the free energy of domain walls at high T can be computed from one and the same observable. We show by explicit calculation that domain walls in hot Z(2) gauge theory have good thermodynamical behaviour. This is due to roughening of the wall, which expresses the restoration of translational symmetry.

  1. Was the big bang hot

    International Nuclear Information System (INIS)

    Wright, E.L.

    1983-01-01

    The author considers experiments to confirm the substantial deviations from a Planck curve in the Woody and Richards spectrum of the microwave background, and search for conducting needles in our galaxy. Spectral deviations and needle-shaped grains are expected for a cold Big Bang, but are not required by a hot Big Bang. (Auth.)

  2. A new hot pressing technique

    International Nuclear Information System (INIS)

    Carcey, J.

    1975-01-01

    An original hot pressing method which may be applied to ceramics, metals, and refractory powders is described. The products obtained are fine grained polycristalline materials, with homogeneous structure, very high density, unstrained and of very large dimensions (several square meters). This process equally applies to composite materials including powders, fibers, etc.. [fr

  3. Hot atom chemistry of carbon

    International Nuclear Information System (INIS)

    Wolf, A.P.

    1975-01-01

    The chemistry of energetic carbon atoms is discussed. The experimental approach to studies that have been carried out is described and the mechanistic framework of hot carbon atom reactions is considered in some detail. Finally, the direction that future work might take is examined, including the relationship of experimental to theoretical work. (author)

  4. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  5. A model for hydrogen pickup for BWR cladding materials

    International Nuclear Information System (INIS)

    Hede, G.; Kaiser, U.

    2001-01-01

    It has been observed that rod elongation is driven by the hydrogen pickup but not by corrosion as such. Based on this a non-destructive method to determine clad hydrogen concentration has been developed. The method is based on the observation that there are three different mechanisms behind the rod growth: the effect of neutron irradiation on the Zircaloy microstructure, the volume increase of the cladding as an effect of hydride precipitation and axial pellet-cladding-mechanical-interaction (PCMI). The derived correlation is based on the experience of older cladding materials, inspected at hot-cell laboratories, that obtained high hydrogen levels (above 500 ppm) at lower burnup (assembly burnup below 50 MWd/kgU). Now this experience can be applied, by interpolation, on more modern cladding materials with a burnup beyond 50 MWd/kgU by analysis of the rod growth database of the respective cladding materials. Hence, the method enables an interpolation rather than an extrapolation of present day hydrogen pickup database, which improves the reliability and accuracy. Further, one can get a good estimate of the hydrogen pickup during an ongoing outage based on a non-destructive method. Finally, rod growth measurements are normally performed for a large population of rods, hence giving a good statistics compared to examination of a few rods at a hot cell. (author)

  6. Exotic atoms

    International Nuclear Information System (INIS)

    Kunselman, R.

    1993-01-01

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

  7. Hydrogen gains further momentum

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

  8. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    . A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling......This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up...

  9. Non-LTE line-blanketed model atmospheres of hot stars. 2: Hot, metal-rich white dwarfs

    Science.gov (United States)

    Lanz, T.; Hubeny, I.

    1995-01-01

    We present several model atmospheres for a typical hot metal-rich DA white dwarf, T(sub eff) = 60,000 K, log g = 7.5. We consider pure hydrogen models, as well as models with various abundances of two typical 'trace' elements-carbon and iron. We calculte a number of Local Thermodynamic Equilibrium (LTE) and non-LTE models, taking into account the effect of numerous lines of these elements on the atmospheric structure. We demostrate that while the non-LTE effects are notvery significant for pure hydrogen models, except for describing correctly the central emission in H-alpha they are essential for predicting correctly the ionization balance of metals, such as carbon and iron. Previously reported discrepancies in LTE abundances determinations using C III and C IV lines are easily explained by non-LTE effects. We show that if the iron abundance is larger than 10(exp -5), the iron line opacity has to be considered not only for the spectrum synthesis, but also in the model construction itself. For such metal abundances, non-LTE metal line-blanketed models are needed for detailed abundance studies of hot, metal-rich white dwarfs. We also discuss the predicted Extreme Ultraviolet (EUV) spectrum and show that it is very sensitive to metal abundances, as well as to non-LTE effects.

  10. Fuel Cell and Hydrogen Technology Validation | Hydrogen and Fuel Cells |

    Science.gov (United States)

    NREL Fuel Cell and Hydrogen Technology Validation Fuel Cell and Hydrogen Technology Validation The NREL technology validation team works on validating hydrogen fuel cell electric vehicles; hydrogen fueling infrastructure; hydrogen system components; and fuel cell use in early market applications such as

  11. Corrosion of a hot potassium carbonate CO/sub 2/ removal plant

    International Nuclear Information System (INIS)

    Johnson, J.J.

    1987-01-01

    After ten years of successful operation, a hot potassium carbonate CO/sub 2/ removal plant experienced severe corrosion to the 2'' (50 mm) thick carbon steel absorber process vessel over a fourteen month period. This corrosive attack resulted in complete penetration on three separate occasions. Although the cause of this corrosion is still uncertain, it appears to be the result of decreasing strength of the vanadium pentoxide inhibitor, due to increasing concentrations of hydrogen sulfide in the feed gas. After extensive research, Chevron believes that stainless steel metallurgy or replacement of the hot potassium carbonate process are the only reliable long-term solutions

  12. Isotopic and chemical features of hot springs in Akita Prefecture

    International Nuclear Information System (INIS)

    Matsubaya, Osamu

    1997-01-01

    All over the Akita Prefecture, many hot springs are located. Most of them are of meteoric water, fossil sea water and volcanic gas origins. In the Ohdate-Kazuno area, moderate temperature hot springs of meteoric water origin are found, which may exist as rather shallow formation water in the Green Tuff formations. On the contrary, high temperature geothermal waters of meteoric origin, which are used for power generation, are obtained in two volcanic area of Hachimantai and Oyasu. Those geothermal waters are expected to come up through vertical fissures from depth deeper than 2 km. The difference of these two manners of meteoric water circulation should be necessarily explained to understand the relationship of shallow and deep geothermal systems. About some hot springs of fossil sea water origin, the relationships of δ D and Cl - don't agree to the mixing relation of sea water and meteoric water. This may be explained by two different processes, one of which is mixing of sea water with saline meteoric water (Cl - ca. 12 g/kg). The other is modification of δD by hydrogen isotopic exchange with hydrous minerals underground, or by exchange with atmospheric vapor during a relic lake before burying. (author)

  13. Pulsational instabilities in hot pre-horizontal branch stars

    Directory of Open Access Journals (Sweden)

    Battich Tiara

    2017-01-01

    Full Text Available The ϵ mechanism is a self-excitation mechanism of pulsations which acts on the regions where nuclear burning takes place. It has been shown that the ϵ mechanism can excite pulsations in models of hot helium-core flash, and that the pulsations of LS IV-14· 116, a He-enriched hot subdwarf star, could be explained that way. We aim to study the ϵmechanism effects on models of hot pre-horizontal branch stars and determine, if possible, a domain of instability in the log g — log Teff plane. We compute non-adiabatic non-radial pulsations on such stellar models, adopting different values of initial chemical abundances and mass of the hydrogen envelope at the time of the main helium flash. We find an instability domain of long-period (400 s ≲ P ≲ 2500 s g-modes for models with 22000K ≲ Teff ≲ 50000K and 4.67 ≲ log g ≲ 6.15.

  14. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Steinbugler, M.; Dennis, E. [Princeton Univ., NJ (United States)] [and others

    1995-09-01

    For several years, researchers at Princeton University`s Center for Energy and Environmental Studies have carried out technical and economic assessments of hydrogen energy systems. Initially, we focussed on the long term potential of renewable hydrogen. More recently we have explored how a transition to renewable hydrogen might begin. The goal of our current work is to identify promising strategies leading from near term hydrogen markets and technologies toward eventual large scale use of renewable hydrogen as an energy carrier. Our approach has been to assess the entire hydrogen energy system from production through end-use considering technical performance, economics, infrastructure and environmental issues. This work is part of the systems analysis activity of the DOE Hydrogen Program. In this paper we first summarize the results of three tasks which were completed during the past year under NREL Contract No. XR-11265-2: in Task 1, we carried out assessments of near term options for supplying hydrogen transportation fuel from natural gas; in Task 2, we assessed the feasibility of using the existing natural gas system with hydrogen and hydrogen blends; and in Task 3, we carried out a study of PEM fuel cells for residential cogeneration applications, a market which might have less stringent cost requirements than transportation. We then give preliminary results for two other tasks which are ongoing under DOE Contract No. DE-FG04-94AL85803: In Task 1 we are assessing the technical options for low cost small scale production of hydrogen from natural gas, considering (a) steam reforming, (b) partial oxidation and (c) autothermal reforming, and in Task 2 we are assessing potential markets for hydrogen in Southern California.

  15. Hydrogen storage container

    Science.gov (United States)

    Wang, Jy-An John; Feng, Zhili; Zhang, Wei

    2017-02-07

    An apparatus and system is described for storing high-pressure fluids such as hydrogen. An inner tank and pre-stressed concrete pressure vessel share the structural and/or pressure load on the inner tank. The system and apparatus provide a high performance and low cost container while mitigating hydrogen embrittlement of the metal tank. System is useful for distributing hydrogen to a power grid or to a vehicle refueling station.

  16. Hydrogen meter prooftesting

    International Nuclear Information System (INIS)

    McCown, J.J.; Mettler, G.W.

    1976-04-01

    Two diffusion type hydrogen meters have been tested on the Prototype Applications Loop (PAL). The ANL designed unit was used to monitor hydrogen in sodium during FFTF startup and over a wide range of hydrogen concentrations resulting from chemical additions to the sodium and cover gas. A commercially available meter was added and its performance compared with the ANL unit. Details of the test work are described

  17. Photochemical hydrogen production system

    International Nuclear Information System (INIS)

    Copeland, R.J.

    1990-01-01

    Both technical and economic factors affect the cost of producing hydrogen by photochemical processes. Technical factors include the efficiency and the capital and operating costs of the renewable hydrogen conversion system; economic factors include discount rates, economic life, credit for co-product oxygen, and the value of the energy produced. This paper presents technical and economic data for a system that generates on-peak electric power form photochemically produced hydrogen

  18. Hydrogen Fuel Cell Vehicles

    OpenAIRE

    Anton Francesch, Judit

    1992-01-01

    Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional, or global pollution. Hydrogen FCEVs would combine the best features of bat...

  19. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  20. Hydrogen gas detector

    International Nuclear Information System (INIS)

    Bohl, T.L.

    1982-01-01

    A differential thermocouple hydrogen gas detector has one thermocouple junction coated with an activated palladium or palladium-silver alloy catalytic material to allow heated hydrogen gas to react with the catalyst and raise the temperature of that junction. The other juction is covered with inert glass or epoxy resin, and does not experience a rise in temperature in the presence of hydrogen gas. A coil heater may be mounted around the thermocouple junctions to heat the hydrogen, or the gas may be passed through a heated block prior to exposing it to the thermocouples

  1. Sustainable hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Block, D.L.; Linkous, C.; Muradov, N.

    1996-01-01

    This report describes the Sustainable Hydrogen Production research conducted at the Florida Solar Energy Center (FSEC) for the past year. The report presents the work done on the following four tasks: Task 1--production of hydrogen by photovoltaic-powered electrolysis; Task 2--solar photocatalytic hydrogen production from water using a dual-bed photosystem; Task 3--development of solid electrolytes for water electrolysis at intermediate temperatures; and Task 4--production of hydrogen by thermocatalytic cracking of natural gas. For each task, this report presents a summary, introduction/description of project, and results.

  2. Purification of hydrogen sulfide

    International Nuclear Information System (INIS)

    Tsao, U.

    1978-01-01

    A process is described for purifying a hydrogen sulfide gas stream containing carbon dioxide, comprising (a) passing the gas stream through a bed of solid hydrated lime to form calcium hydrosulfide and calcium carbonate and (b) regenerating hydrogen sulfide from said calcium hydrosulfide by reacting the calcium hydrosulfide with additional carbon dioxide. The process is especially applicable for use in a heavy water recovery process wherein deuterium is concentrated from a feed water containing carbon dioxide by absorption and stripping using hydrogen sulfide as a circulating medium, and the hydrogen sulfide absorbs a small quantity of carbon dioxide along with deuterium in each circulation

  3. New hydrogen technologies

    International Nuclear Information System (INIS)

    1992-01-01

    This report presents an overview of the overall hydrogen system. There are separate sections for production, distribution, transport, storage; and applications of hydrogen. The most important methods for hydrogen production are steam reformation of natural gas and electrolysis of water. Of the renewable energy options, production of hydrogen by electrolysis using electricity from wind turbines or by gasification of biomass were found to be the most economic for Finland. Direct use of this electricity or the production of liquid fuels from biomass will be competing alternatives. When hydrogen is produced in the solar belt or where there is cheap hydropower it must be transported over long distances. The overall energy consumed for the transport is from 25 to 40 % of the initial available energy. Hydrogen storage can be divided into stationary and mobile types. The most economic, stationary, large scale hydrogen storage for both long and short periods is underground storage. When suitable sites are not available, then pressure vessels are the best for short period and liquid H 2 for long period. Vehicle storage of hydrogen is by either metal hydrides or liquid H 2 . Hydrogen is a very versatile energy carrier. It can be used to produce heat directly in catalytic burners without flame, to produce electricity in fuel cells with high efficiency for use in vehicles or for peak power shaving, as a fuel component with conventional fuels to reduce emissions, as a way to store energy and as a chemical reagent in reactions

  4. Hydrogen as automotive fuel

    International Nuclear Information System (INIS)

    Ambrosini, G.; Ciancia, A.; Pede, G.; Brighigna, M.

    1993-01-01

    Hydrogen fueled vehicles may just be the answer to the air pollution problem in highly polluted urban environments where the innovative vehicle's air pollution abatement characteristics would justify its high operating costs as compared with those of conventional automotive alternatives. This paper examines the feasibility of hydrogen as an automotive fuel by analyzing the following aspects: the chemical-physical properties of hydrogen in relation to its use in internal combustion engines; the modifications necessary to adapt internal combustion engines to hydrogen use; hydrogen fuel injection systems; current production technologies and commercialization status of hydrogen automotive fuels; energy efficiency ratings; environmental impacts; in-vehicle storage systems - involving the use of hydrides, high pressure systems and liquid hydrogen storage systems; performance in terms of pay-load ratio; autonomous operation; and operating costs. With reference to recent trial results being obtained in the USA, an assessment is also made of the feasibility of the use of methane-hydrogen mixtures as automotive fuels. The paper concludes with a review of progress being made by ENEA (the Italian Agency for New Technology, Energy and the Environment) in the development of fuel storage and electronic fuel injection systems for hydrogen powered vehicles

  5. Hydrogen as automotive fuel

    International Nuclear Information System (INIS)

    Dini, D.; Ciancia, A.; Pede, G.; Sglavo, V.; ENEA, Rome

    1992-01-01

    An assessment of the technical/economic feasibility of the use of hydrogen as an automotive fuel is made based on analyses of the following: the chemical- physical properties of hydrogen in relation to its use in internal combustion engines; the modifications necessary to adapt internal combustion engines to hydrogen use; hydrogen fuel injection systems - with water vapour injection, cryogenic injection, and the low or high pressure injection of hydrogen directly into the combustion chamber; the current commercialization status of hydrogen automotive fuels; energy efficiency ratings; environmental impacts; in-vehicle storage systems - involving the use of hydrides, high pressure systems and liquid hydrogen storage systems; performance in terms of pay-load ratio; autonomous operation; and operating costs. The paper concludes that, considering current costs for hydrogen fuel production, distribution and use, at present, the employment of hydrogen fuelled vehicles is feasible only in highly polluted urban environments where the innovative vehicle's air pollution abatement characteristics would justify its high operating costs as compared with those of conventional automotive alternatives

  6. Palladium Nanoparticle Hydrogen Sensor

    Directory of Open Access Journals (Sweden)

    I. Pavlovsky

    2006-12-01

    Full Text Available An innovative hydrogen sensor based on palladium (Pd nanoparticle networks is described in the article. Made by Applied Nanotech Inc. sensor has a fast response time, in the range of seconds, which is increased at 80 °C due to higher hydrogen diffusion rates into the palladium lattice. The low detection limit of the sensor is 10 ppm of H2, and the high limit is 40,000 ppm. This is 100% of a lowest flammability level of hydrogen. This range of sensitivities complies with the requirements that one would expect for a reliable hydrogen sensor.

  7. Atomic hydrogen reactor

    International Nuclear Information System (INIS)

    Massip de Turville, C.M.D.

    1982-01-01

    Methods are discussed of generating heat in an atomic hydrogen reactor which involve; the production of atomic hydrogen by an electrical discharge, the capture of nascent neutrons from atomic hydrogen in a number of surrounding steel alloy tubes having a high manganese content to produce 56 Mn, the irradiation of atomic hydrogen by the high energy antineutrinos from the beta decay of 56 Mn to yield nascent neutrons, and the removal of the heat generated by the capture of nascent neutrons by 55 Mn and the beta decay of 56 Mn. (U.K.)

  8. Hot Flashes amd Night Sweats (PDQ)

    Science.gov (United States)

    ... Professionals Questions to Ask about Your Treatment Research Hot Flashes and Night Sweats (PDQ®)–Patient Version Overview ... quality of life in many patients with cancer. Hot flashes and night sweats may be side effects ...

  9. Hot Laboratories and Remote Handling

    International Nuclear Information System (INIS)

    Bart, G.; Blanc, J.Y.; Duwe, R.

    2003-01-01

    The European Working Group on ' Hot Laboratories and Remote Handling' is firmly established as the major contact forum for the nuclear R and D facilities at the European scale. The yearly plenary meetings intend to: - Exchange experience on analytical methods, their implementation in hot cells, the methodologies used and their application in nuclear research; - Share experience on common infrastructure exploitation matters such as remote handling techniques, safety features, QA-certification, waste handling; - Promote normalization and co-operation, e.g., by looking at mutual complementarities; - Prospect present and future demands from the nuclear industry and to draw strategic conclusions regarding further needs. The 41. plenary meeting was held in CEA Saclay from September 22 to 24, 2003 in the premises and with the technical support of the INSTN (National Institute for Nuclear Science and Technology). The Nuclear Energy Division of CEA sponsored it. The Saclay meeting was divided in three topical oral sessions covering: - Post irradiation examination: new analysis methods and methodologies, small specimen technology, programmes and results; - Hot laboratory infrastructure: decommissioning, refurbishment, waste, safety, nuclear transports; - Prospective research on materials for future applications: innovative fuels (Generation IV, HTR, transmutation, ADS), spallation source materials, and candidate materials for fusion reactor. A poster session was opened to transport companies and laboratory suppliers. The meeting addressed in three sessions the following items: Session 1 - Post Irradiation Examinations. Out of 12 papers (including 1 poster) 7 dealt with surface and solid state micro analysis, another one with an equally complex wet chemical instrumental analytical technique, while the other four papers (including the poster) presented new concepts for digital x-ray image analysis; Session 2 - Hot laboratory infrastructure (including waste theme) which was

  10. The 2s1/2 → 2p1/2 + one photon transition in hydrogen and hydrogenlike ions

    International Nuclear Information System (INIS)

    Kelsey, E.J.

    1977-01-01

    The 2s 1 / 2 → 2p 1 / 2 + one photon transition rate is calculated and discussed for hydrogen and hydrogenlike ions. It is noted that the induced transition rather than the spontaneous transition is of primary importance since it is the basis of many of the precision Lamb-shift measurements. The lack of a calculation of the transition rate other than a heuristic nonrelativistic derivation which requires a nontrivial assumption motivates the calculation presented here based on the external field approximation to quantum electrodynamics. It is found that the heuristic answer is correct in lowest order. In this derivation we see that the 2s 1 / 2 → 2p 1 / 2 + one photon transition gives an apparent contradiction to the often-stated remark that for the electric dipole matrix element there exist three equivalent representations, the ''length,'' ''velocity,'' and ''acceleration'' forms. The difficulties of an experimental determination of this transition rate using induced transitions in hydrogenlike ions are briefly noted as well as the somewhat different case of heavy muonic atoms where the spontaneous 2s 1 / 2 → 2p 1 / 2 + one photon transition has been observed

  11. OUT Success Stories: Solar Hot Water Technology

    International Nuclear Information System (INIS)

    Clyne, R.

    2000-01-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building

  12. OUT Success Stories: Solar Hot Water Technology

    Science.gov (United States)

    Clyne, R.

    2000-08-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  13. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T [Ann Arbor, MI; Li, Yingwel [Ann Arbor, MI; Lachawiec, Jr., Anthony J.

    2011-05-31

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonification as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  14. Recent trend of administration on hot springs

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, Shigeru [Environment Agency, Tokyo (Japan)

    1989-01-01

    The Environmental Agency exercises jurisdiction over Hot Spring Act, and plans to protect the source of the hot spring and to utilize it appropriately. From the aspect of utilization, hot springs are widely used as a means to remedy chronic diseases and tourist spots besides places for recuperation and repose. Statistics on Japanese hot springs showed that the number of hot spring spots and utilized-fountainhead increased in 1987, compared with the number in 1986. Considering the utilized-headspring, the number of naturally well-out springs has stabilized for 10 years while power-operated springs have increased. This is because the demand of hot springs has grown as the number of users has increased. Another reason is to keep the amount of hot water by setting up the power facility as the welled-out amount has decreased. Major point of recent administration on the hot spring is to permit excavation and utilization of hot springs. Designation of National hot spring health resorts started in 1954 in order to ensure the effective and original use of hot springs and to promote the public use of them, for the purpose of arranging the sound circumstances of hot springs. By 1988, 76 places were designated. 4 figs., 3 tabs.

  15. Process for exchanging hydrogen isotopes between gaseous hydrogen and water

    International Nuclear Information System (INIS)

    Hindin, S. G.; Roberts, G. W.

    1980-01-01

    A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst

  16. Hydrogen assisted diesel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lilik, Gregory K.; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Zhang, Hedan; Haworth, Daniel C. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Herreros, Jose Martin [Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Castilla La-Mancha, Avda. Camilo Jose Cela s/n, 13071 Ciudad Real (Spain)

    2010-05-15

    Hydrogen assisted diesel combustion was investigated on a DDC/VM Motori 2.5L, 4-cylinder, turbocharged, common rail, direct injection light-duty diesel engine, with a focus on exhaust emissions. Hydrogen was substituted for diesel fuel on an energy basis of 0%, 2.5%, 5%, 7.5%, 10% and 15% by aspiration of hydrogen into the engine's intake air. Four speed and load conditions were investigated (1800 rpm at 25% and 75% of maximum output and 3600 rpm at 25% and 75% of maximum output). A significant retarding of injection timing by the engine's electronic control unit (ECU) was observed during the increased aspiration of hydrogen. The retarding of injection timing resulted in significant NO{sub X} emission reductions, however, the same emission reductions were achieved without aspirated hydrogen by manually retarding the injection timing. Subsequently, hydrogen assisted diesel combustion was examined, with the pilot and main injection timings locked, to study the effects caused directly by hydrogen addition. Hydrogen assisted diesel combustion resulted in a modest increase of NO{sub X} emissions and a shift in NO/NO{sub 2} ratio in which NO emissions decreased and NO{sub 2} emissions increased, with NO{sub 2} becoming the dominant NO{sub X} component in some combustion modes. Computational fluid dynamics analysis (CFD) of the hydrogen assisted diesel combustion process captured this trend and reproduced the experimentally observed trends of hydrogen's effect on the composition of NO{sub X} for some operating conditions. A model that explicitly accounts for turbulence-chemistry interactions using a transported probability density function (PDF) method was better able to reproduce the experimental trends, compared to a model that ignores the influence of turbulent fluctuations on mean chemical production rates, although the importance of the fluctuations is not as strong as has been reported in some other recent modeling studies. The CFD results confirm

  17. Hot sample archiving. Revision 3

    International Nuclear Information System (INIS)

    McVey, C.B.

    1995-01-01

    This Engineering Study revision evaluated the alternatives to provide tank waste characterization analytical samples for a time period as recommended by the Tank Waste Remediation Systems Program. The recommendation of storing 40 ml segment samples for a period of approximately 18 months (6 months past the approval date of the Tank Characterization Report) and then composite the core segment material in 125 ml containers for a period of five years. The study considers storage at 222-S facility. It was determined that the critical storage problem was in the hot cell area. The 40 ml sample container has enough material for approximately 3 times the required amount for a complete laboratory re-analysis. The final result is that 222-S can meet the sample archive storage requirements. During the 100% capture rate the capacity is exceeded in the hot cell area, but quick, inexpensive options are available to meet the requirements

  18. Possibility of hydrogen supply by shared residential fuel cell systems for fuel cell vehicles

    Directory of Open Access Journals (Sweden)

    Ono Yusuke

    2017-01-01

    Full Text Available Residential polymer electrolyte fuel cells cogeneration systems (residential PEFC systems produce hydrogen from city gas by internal gas-reformer, and generate electricity, the hot water at the same time. From the viewpoint of the operation, it is known that residential PEFC systems do not continuously work but stop for long time, because the systems generate enough hot water for short operation time. In other words, currently residential PEFC systems are dominated by the amount of hot water demand. This study focuses on the idle time of residential PEFC systems. Since their gas-reformers are free, the systems have potential to produce hydrogen during the partial load operations. The authors expect that residential PEFC systems can take a role to supply hydrogen for fuel cell vehicles (FCVs before hydrogen fueling stations are distributed enough. From this perspective, the objective of this study is to evaluate the hydrogen production potential of residential PEFC systems. A residential PEFC system was modeled by the mixed integer linear programming to optimize the operation including hydrogen supply for FCV. The objective function represents annual system cost to be minimized with the constraints of energy balance. It should be noted that the partial load characteristics of the gas-reformer and the fuel cell stack are taken into account to derive the optimal operation. The model was employed to estimate the possible amount of hydrogen supply by a residential PEFC system. The results indicated that the system could satisfy at least hydrogen demand for transportation of 8000 km which is as far as the average annual mileage of a passenger car in Japan. Furthermore, hydrogen production by sharing a residential PEFC system with two households is more effective to reduce primary energy consumption with hydrogen supply for FCV than the case of introducing PEFC in each household.

  19. Hydrogen and fuel cells

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the hydrogen and fuel cells. It presents the hydrogen technology from the production to the distribution and storage, the issues as motor fuel and fuel cells, the challenge for vehicles applications and the Total commitments in the domain. (A.L.B.)

  20. Hydrogen in amorphous silicon

    International Nuclear Information System (INIS)

    Peercy, P.S.

    1980-01-01

    The structural aspects of amorphous silicon and the role of hydrogen in this structure are reviewed with emphasis on ion implantation studies. In amorphous silicon produced by Si ion implantation of crystalline silicon, the material reconstructs into a metastable amorphous structure which has optical and electrical properties qualitatively similar to the corresponding properties in high-purity evaporated amorphous silicon. Hydrogen studies further indicate that these structures will accomodate less than or equal to 5 at.% hydrogen and this hydrogen is bonded predominantly in a monohydride (SiH 1 ) site. Larger hydrogen concentrations than this can be achieved under certain conditions, but the excess hydrogen may be attributed to defects and voids in the material. Similarly, glow discharge or sputter deposited amorphous silicon has more desirable electrical and optical properties when the material is prepared with low hydrogen concentration and monohydride bonding. Results of structural studies and hydrogen incorporation in amorphous silicon were discussed relative to the different models proposed for amorphous silicon

  1. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  2. Hydrogen Storage Tank

    CERN Multimedia

    1983-01-01

    This huge stainless steel reservoir,placed near an end of the East Hall, was part of the safety equipment connected to the 2 Metre liquid hydrogen Bubble Chamber. It could store all the hydrogen in case of an emergency. The picture shows the start of its demolition.

  3. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  4. Hydrogen pellet injection device

    International Nuclear Information System (INIS)

    Kanno, Masahiro.

    1992-01-01

    In a hydrogen pellet injection device, a nozzle block having a hydrogen gas supply channel is disposed at the inner side of a main cryogenic housing, and an electric resistor is attached to the block. Further, a nozzle block and a hydrogen gas introduction pipe are attached by way of a thermal insulating spacer. Electric current is supplied to the resistor to positively heat the nozzle block and melt remaining solid hydrogen in the hydrogen gas supply channel. Further, the effect of temperature elevation due to the resistor is prevented from reaching the side of the hydrogen gas introduction pipe by the thermal insulation spacer. That is, the temperature of the nozzle block is directly and positively elevated, to melt the solid hydrogen rapidly. Preparation operation from the injection of the hydrogen pellet to the next injection can be completed in a shorter period of time compared with a conventional case thereby enabling to make the test more efficient. Further, only the temperature of the nozzle block is elevated with no effect of temperature elevation due to the resistor to other components by the thermal insulation flange. (N.H.)

  5. Hydrogen from biomass

    NARCIS (Netherlands)

    Claassen, P.A.M.; Vrije, de G.J.

    2006-01-01

    Hydrogen is generally regarded as the energy carrier of the future. The development of a process for hydrogen production from biomass complies with the policy of the Dutch government to obtain more renewable energy from biomass. This report describes the progress of the BWP II project, phase 2 of

  6. Hydrogen evolution by a thermophilic blue-green alga. Mastigocladus laminosus

    Energy Technology Data Exchange (ETDEWEB)

    Mirua, Y; Yokoyama, H; Kanaoka, K; Saito, S; Iwasa, K; Okazaki, M; Komemushi, S

    1980-01-01

    The thermophillic blue-green alga (cyanobacterium), Mastigocladus laminosus isolated from a hot spring, evolved hydrogen gas under nitrogen-starved conditions in light when algal cells were grown in a nitrate-free medium. Cells grown in a nitrate-medium evolved no detectable hydrogen gas in light. The optimal temperature and pH for hydrogen evolution were 44-49 degrees C and 7.0-7.5. High activity of hydrogen evolution, 1.6 ml H/sub 2//mg chl.hr, was induced when algal cells grown in the nitrate medium were actively forming heterocysts in the nitrate-free medium in air. Hydrogen evolution in light was depressed by nitrogen gas and inhibited by salicylaldoxime or DNP. This hydrogen evolution by M. laminosus is attributed to the action of nitrogenase.

  7. Fiscal 1996 achievement report. International Clean Energy Network Using Hydrogen Conversion (WE-NET) technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Research and development was performed for the WE-NET (World Energy Network) project which aims to carry out hydrogen production, transportation, and supply to consumers, by the use of renewable energy. Under subtask 1, the whole WE-NET project was subjected to evaluation, which included coordination between the respective tasks. Under subtask 2, information exchange and research cooperation were carried out with research institutes overseas. Under subtask 3, a conceptual design was prepared of a total system using ammonia as the medium for hydrogen transportation, accident data were collected and screened, and safety measures and evaluation techniques were developed and improved. Under subtask 4, the hot press method and the electroless plating method were selected as better electrode bonding methods. Under subtask 5, hydrogen liquefaction cycle processes, liquid hydrogen tankers, storage facilities, etc., were studied. Under subtasks 6-9, furthermore, investigations were conducted about low-temperature substance technology, hydrogen energy, hydrogen combustion turbine, etc. (NEDO)

  8. Magnetohydrodynamic simulations of hot jupiter upper atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Trammell, George B.; Li, Zhi-Yun; Arras, Phil, E-mail: gbt8f@virginia.edu, E-mail: zl4h@virginia.edu, E-mail: arras@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2014-06-20

    Two-dimensional simulations of hot Jupiter upper atmospheres including the planet's magnetic field are presented. The goal is to explore magnetic effects on the layer of the atmosphere that is ionized and heated by stellar EUV radiation, and the imprint of these effects on the Lyα transmission spectrum. The simulations are axisymmetric, isothermal, and include both rotation and azimuth-averaged stellar tides. Mass density is converted to atomic hydrogen density through the assumption of ionization equilibrium. The three-zone structure—polar dead zone (DZ), mid-latitude wind zone (WZ), and equatorial DZ—found in previous analytic calculations is confirmed. For a magnetic field comparable to that of Jupiter, the equatorial DZ, which is confined by the magnetic field and corotates with the planet, contributes at least half of the transit signal. For even stronger fields, the gas escaping in the mid-latitude WZ is found to have a smaller contribution to the transit depth than the equatorial DZ. Transmission spectra computed from the simulations are compared to Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys data for HD 209458b and HD 189733b, and the range of model parameters consistent with the data is found. The central result of this paper is that the transit depth increases strongly with magnetic field strength when the hydrogen ionization layer is magnetically dominated, for dipole magnetic field B {sub 0} ≳ 10 G. Hence transit depth is sensitive to magnetic field strength, in addition to standard quantities such as the ratio of thermal to gravitational binding energies. Another effect of the magnetic field is that the planet loses angular momentum orders of magnitude faster than in the non-magnetic case, because the magnetic field greatly increases the lever arm for wind braking of the planet's rotation. Spin-down timescales for magnetized models of HD 209458b that agree with the observed transit depth

  9. Next-generation TCAP hydrogen isotope separation process

    International Nuclear Information System (INIS)

    Heung, L. K.; Sessions, H. T.; Poore, A. S.; Jacobs, W. D.; Williams, C. S.

    2008-01-01

    A thermal cycling absorption process (TCAP) for hydrogen isotope separation has been in operation at Savannah River Site since 1994. The process uses a hot/cold nitrogen system to cycle the temperature of the separation column. The hot/cold nitrogen system requires the use of large compressors, heat exchanges, valves and piping that is bulky and maintenance intensive. A new compact thermal cycling (CTC) design has recently been developed. This new design uses liquid nitrogen tubes and electric heaters to heat and cool the column directly so that the bulky hot/cold nitrogen system can be eliminated. This CTC design is simple and is easy to implement, and will be the next generation TCAP system at SRS. A twelve-meter column has been fabricated and installed in the laboratory to demonstrate its performance. The design of the system and its test results to date is discussed. (authors)

  10. Measures for removing hydrogen

    International Nuclear Information System (INIS)

    Baukal, W.; Koehling, A.; Langer, G.; Poeschel, E.

    1984-01-01

    Basis for the investigation is a 1300-MW-PWR. The evolution of hydrogen was studied in design-basis and three hypothetical accident scenarios, the loss-of-coolant accident, the failure of emergency cooling system and core meltdown. It was shown that in the case of release rates of 4m 3 H 2 /h, the known post-accident hydrogen removal systems can be used and at medium rates up to 80 m 3 H 2 /h recombines of nuclear and non-nuclear industries are suitable under certain conditions. In the case of larger release rates it appears useful to apply a small recombiner of the type of the post-accident hydrogen removal system combined with an other hydrogen countermeasures. Recommendations are being made for the installation of an accident-proof hydrogen measuring system. (DG) [de

  11. Liquid hydrogen properties

    International Nuclear Information System (INIS)

    Choi, Jung Woon; Kim, Y. J.; Lee, K. H.; Kim, H. I.; Han, K. Y.; Park, J.H.

    2004-03-01

    The purpose of this report is to provide the input data, whose characteristic is thermodynamic and transport, in the form of equation for the thermo-hydraulic calculations using hydrogen as a working substance. The considered data in this report are particularly focused on the properties of para-hydrogen and of equilibrium-hydrogen around the working temperature range of the HANARO-CNS. The discussed properties of hydrogen are, in turn, the pressure of saturated vapors, the density, the heat of vaporization, thermal conductivity, viscosity, and heat capacity. Several equations to fit the above-mentioned experimental data allow calculating the various properties of liquid hydrogen with high accuracy at all considered temperatures

  12. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)

    2016-01-21

    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  13. Hydrogen production methods

    International Nuclear Information System (INIS)

    Hammerli, M.

    1982-07-01

    Old, present and new proceses for producing hydrogen are assessed critically. The emphasis throughout is placed on those processes which could be commercially viable before the turn of the century for large-scale hydrogen manufacture. Electrolysis of water is the only industrial process not dependent on fossil resources for large-scale hydrogen production and is likely to remain so for the next two or three decades. While many new processes, including those utilizing sunlight directly or indirectly, are presently not considered to be commercially viable for large-scale hydrogen production, research and development effort is needed to enhance our understanding of the nature of these processes. Water vapour electrolysis is compared with thermochemical processes: the former has the potential for displacing all other processes for producing hydrogen and oxygen from water

  14. Hydrogen storage using borohydrides

    International Nuclear Information System (INIS)

    Bernard BONNETOT; Laetitia LAVERSENNE

    2006-01-01

    The possibilities of hydrogen storage using borohydrides are presented and discussed specially in regard of the recoverable hydrogen amount and related to the recovering conditions. A rapid analysis of storage possibilities is proposed taking in account the two main ways for hydrogen evolution: the dehydrogenation obtained through thermal decomposition or the hydrolysis of solids or solutions. The recoverable hydrogen is related to the dehydrogenation conditions and the real hydrogen useful percentage is determined for each case of use. The high temperature required for dehydrogenation even when using catalyzed compounds lead to poor outlooks for this storage way. The hydrolysis conditions direct the chemical yield of the water consuming, and this must be related to the experimental conditions which rule the storage capacity of the 'fuel' derived from the borohydride. (authors)

  15. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  16. Computational prediction of protein hot spot residues.

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2012-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues.

  17. Computational Prediction of Hot Spot Residues

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2013-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues. PMID:22316154

  18. Hydrogen molecules and hydrogen-related defects in crystalline silicon

    Science.gov (United States)

    Fukata, N.; Sasaki, S.; Murakami, K.; Ishioka, K.; Nakamura, K. G.; Kitajima, M.; Fujimura, S.; Kikuchi, J.; Haneda, H.

    1997-09-01

    We have found that hydrogen exists in molecular form in crystalline silicon treated with hydrogen atoms in the downstream of a hydrogen plasma. The vibrational Raman line of hydrogen molecules is observed at 4158 cm-1 for silicon samples hydrogenated between 180 and 500 °C. The assignment of the Raman line is confirmed by its isotope shift to 2990 cm-1 for silicon treated with deuterium atoms. The Raman intensity has a maximum for hydrogenation at 400 °C. The vibrational Raman line of the hydrogen molecules is broad and asymmetric. It consists of at least two components, possibly arising from hydrogen molecules in different occupation sites in crystalline silicon. The rotational Raman line of hydrogen molecules is observed at 590 cm-1. The Raman band of Si-H stretching is observed for hydrogenation temperatures between 100 and 500 °C and the intensity has a maximum for hydrogenation at 250 °C.

  19. Co-Occurring Atomic Contacts for the Characterization of Protein Binding Hot Spots

    Science.gov (United States)

    Liu, Qian; Ren, Jing; Song, Jiangning; Li, Jinyan

    2015-01-01

    A binding hot spot is a small area at a protein-protein interface that can make significant contribution to binding free energy. This work investigates the substantial contribution made by some special co-occurring atomic contacts at a binding hot spot. A co-occurring atomic contact is a pair of atomic contacts that are close to each other with no more than three covalent-bond steps. We found that two kinds of co-occurring atomic contacts can play an important part in the accurate prediction of binding hot spot residues. One is the co-occurrence of two nearby hydrogen bonds. For example, mutations of any residue in a hydrogen bond network consisting of multiple co-occurring hydrogen bonds could disrupt the interaction considerably. The other kind of co-occurring atomic contact is the co-occurrence of a hydrophobic carbon contact and a contact between a hydrophobic carbon atom and a π ring. In fact, this co-occurrence signifies the collective effect of hydrophobic contacts. We also found that the B-factor measurements of several specific groups of amino acids are useful for the prediction of hot spots. Taking the B-factor, individual atomic contacts and the co-occurring contacts as features, we developed a new prediction method and thoroughly assessed its performance via cross-validation and independent dataset test. The results show that our method achieves higher prediction performance than well-known methods such as Robetta, FoldX and Hotpoint. We conclude that these contact descriptors, in particular the novel co-occurring atomic contacts, can be used to facilitate accurate and interpretable characterization of protein binding hot spots. PMID:26675422

  20. The hydrogen highway

    International Nuclear Information System (INIS)

    Grigg, A.

    2004-01-01

    'Full text:' The Hydrogen Highway in British Columbia, Canada, is a coordinated, large-scale demonstration and deployment program aimed at accelerating the commercialization of hydrogen and fuel cell technologies and products. It will be a showcase for fuel cell vehicles, refuelling stations and stationary power systems leading up to the 2010 Olympic and Paralympic Winter Games in Whistler, BC. The Hydrogen Highway is designed to help address many of the challenges to commercialization identified in the Canadian Fuel Cell Commercialization Roadmap. The project will create an early adopter network of hydrogen and fuel cell microenvironments where technology developers and users can learn about the technical, economic, environmental and social impacts of products. The Hydrogen Highway will give the public and potential purchasers an opportunity to feel, touch and see the new technology, as well as provide the industry with a venue in which to develop industry standards and supply chains of materials and components. While demonstration and deployment programs are a recognized and necessary component in the process to commercialize hydrogen and fuel cell technologies, there is no handbook describing how it should be done. This paper will describe the history, objectives, project details and some of the challenges associated with establishing Canada's Hydrogen Highway. (author)

  1. The hydrogen highway

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, A. [Fuel Cells Canada, Vancouver, British Columbia (Canada)

    2004-07-01

    'Full text:' The Hydrogen Highway in British Columbia, Canada, is a coordinated, large-scale demonstration and deployment program aimed at accelerating the commercialization of hydrogen and fuel cell technologies and products. It will be a showcase for fuel cell vehicles, refuelling stations and stationary power systems leading up to the 2010 Olympic and Paralympic Winter Games in Whistler, BC. The Hydrogen Highway is designed to help address many of the challenges to commercialization identified in the Canadian Fuel Cell Commercialization Roadmap. The project will create an early adopter network of hydrogen and fuel cell microenvironments where technology developers and users can learn about the technical, economic, environmental and social impacts of products. The Hydrogen Highway will give the public and potential purchasers an opportunity to feel, touch and see the new technology, as well as provide the industry with a venue in which to develop industry standards and supply chains of materials and components. While demonstration and deployment programs are a recognized and necessary component in the process to commercialize hydrogen and fuel cell technologies, there is no handbook describing how it should be done. This paper will describe the history, objectives, project details and some of the challenges associated with establishing Canada's Hydrogen Highway. (author)

  2. A green hydrogen economy

    Energy Technology Data Exchange (ETDEWEB)

    Clark, W.W. II [Clark Communications, Beverly Hills, CA (United States). Green Hydrogen Scientific Advisory Committee; Rifkin, J. [The Foundation on Economic Trends (United States)

    2006-11-15

    This paper is the result of over a dozen scholars and practitioners who strongly felt that a hydrogen economy and hence the future is closer than some American politicians and bureaucrats state. Moreover, when seen internationally, there is strong evidence, the most recent and obvious ones are the proliferation of hybrid vehicles, that for any nation-state to be energy independent it must seek a renewable or green hydrogen future in the near term. The State of California has once again taken the lead in this effort for both an energy-independent future and one linked strongly to the hydrogen economy. Then why a hydrogen economy in the first instance? The fact is that hydrogen most likely will not be used for refueling of vehicles in the near term. The number of vehicles to make hydrogen commercially viable will not be in the mass market by almost all estimates until 2010. However, it is less than a decade away. The time frame is NOT 30-40 years as some argue. The hydrogen economy needs trained people, new ventures and public-private partnerships now. The paper points out how the concerns of today, including higher costs and technologies under development, can be turned into opportunities for both the public and private sectors. It was not too long ago that the size of a mobile phone was that of a briefcase, and then almost 10 years ago, the size of a shoe box. Today, they are not only the size of a man's wallet but also often given away free to consumers who subscribe or contract for wireless services. While hydrogen may not follow this technological commercialization exactly, it certainly will be on a parallel path. International events and local or regional security dictate that the time for a hydrogen must be close at hand. (author)

  3. A green hydrogen economy

    International Nuclear Information System (INIS)

    Clark, Woodrow W.; Rifkin, Jeremy

    2006-01-01

    This paper is the result of over a dozen scholars and practitioners who strongly felt that a hydrogen economy and hence the future is closer than some American politicians and bureaucrats state. Moreover, when seen internationally, there is strong evidence, the most recent and obvious ones are the proliferation of hybrid vehicles, that for any nation-state to be energy independent it must seek a renewable or green hydrogen future in the near term. The State of California has once again taken the lead in this effort for both an energy-independent future and one linked strongly to the hydrogen economy. Then why a hydrogen economy in the first instance? The fact is that hydrogen most likely will not be used for refueling of vehicles in the near term. The number of vehicles to make hydrogen commercially viable will not be in the mass market by almost all estimates until 2010. However, it is less than a decade away. The time frame is NOT 30-40 years as some argue. The hydrogen economy needs trained people, new ventures and public-private partnerships now. The paper points out how the concerns of today, including higher costs and technologies under development, can be turned into opportunities for both the public and private sectors. It was not too long ago that the size of a mobile phone was that of a briefcase, and then almost 10 years ago, the size of a shoe box. Today, they are not only the size of a man's wallet but also often given away free to consumers who subscribe or contract for wireless services. While hydrogen may not follow this technological commercialization exactly, it certainly will be on a parallel path. International events and local or regional security dictate that the time for a hydrogen must be close at hand

  4. The Italian hydrogen programme

    International Nuclear Information System (INIS)

    Raffaele Vellone

    2001-01-01

    Hydrogen could become an important option in the new millennium. It provides the potential for a sustainable energy system as it can be used to meet most energy needs without harming the environment. In fact, hydrogen has the potential for contributing to the reduction of climate-changing emissions and other air pollutants as it exhibits clean combustion with no carbon or sulphur oxide emissions and very low nitrogen oxide emissions. Furthermore, it is capable of direct conversion to electricity in systems such as fuel cells without generating pollution. However, widespread use of hydrogen is not feasible today because of economic and technological barriers. In Italy, there is an ongoing national programme to facilitate the introduction of hydrogen as an energy carrier. This programme aims to promote, in an organic frame, a series of actions regarding the whole hydrogen cycle. It foresees the development of technologies in the areas of production, storage, transport and utilisation. Research addresses the development of technologies for separation and sequestration of CO 2 , The programme is shared by public organisations (research institutions and universities) and national industry (oil companies, electric and gas utilities and research institutions). Hydrogen can be used as a fuel, with significant advantages, both for electric energy generation/ co-generation (thermo-dynamic cycles and fuel cells) and transportation (internal combustion engine and fuel cells). One focus of research will be the development of fuel cell technologies. Fuel cells possess all necessary characteristics to be a key technology in a future economy based on hydrogen. During the initial phase of the project, hydrogen will be derived from fossil sources (natural gas), and in the second phase it will be generated from renewable electricity or nuclear energy. The presentation will provide a review of the hydrogen programme and highlight future goals. (author)

  5. Transient shielded liquid hydrogen containers

    International Nuclear Information System (INIS)

    Varghese, A.P.; Herring, R.H.

    1990-01-01

    The storage of hydrogen in the liquid phase has been limited in duration due to the thermal performance constraints of conventional Liquid Hydrogen containers available. Conventional Liquid Hydrogen containers lose hydrogen because of their relatively high heat leak and variations in usage pattern of hydrogen due to shutdowns. Local regulations also discourage venting of hydrogen. Long term storage of Liquid Hydrogen without product loss was usually accomplished using Liquid Nitrogen sacrificial shields. This paper reports on a new low heat leak container developed and patented that will extend the storage time of liquid hydrogen by five hundred percent. The principle of operation of the Transient Shields which makes the extraordinary performance of this container feasible is described in this paper. Also covered are the impact of this new container on present applications of hydrogen and the new opportunities afforded to Liquid hydrogen in the world hydrogen market

  6. Hot Laboratories and Remote Handling

    International Nuclear Information System (INIS)

    2007-01-01

    The Opening talk of the workshop 'Hot Laboratories and Remote Handling' was given by Marin Ciocanescu with the communication 'Overview of R and D Program in Romanian Institute for Nuclear Research'. The works of the meeting were structured into three sections addressing the following items: Session 1. Hot cell facilities: Infrastructure, Refurbishment, Decommissioning; Session 2. Waste, transport, safety and remote handling issues; Session 3. Post-Irradiation examination techniques. In the frame of Section 1 the communication 'Overview of hot cell facilities in South Africa' by Wouter Klopper, Willie van Greunen et al, was presented. In the framework of the second session there were given the following four communications: 'The irradiated elements cell at PHENIX' by Laurent Breton et al., 'Development of remote equipment for DUPIC fuel fabrication at KAERI', by Jung Won Lee et al., 'Aspects of working with manipulators and small samples in an αβγ-box, by Robert Zubler et al., and 'The GIOCONDA experience of the Joint Research Centre Ispra: analysis of the experimental assemblies finalized to their safe recovery and dismantling', by Roberto Covini. Finally, in the framework of the third section the following five communications were presented: 'PIE of a CANDU fuel element irradiated for a load following test in the INR TRIGA reactor' by Marcel Parvan et al., 'Adaptation of the pole figure measurement to the irradiated items from zirconium alloys' by Yury Goncharenko et al., 'Fuel rod profilometry with a laser scan micrometer' by Daniel Kuster et al., 'Raman spectroscopy, a new facility at LECI laboratory to investigate neutron damage in irradiated materials' by Lionel Gosmain et al., and 'Analysis of complex nuclear materials with the PSI shielded analytical instruments' by Didier Gavillet. In addition, eleven more presentations were given as posters. Their titles were: 'Presentation of CETAMA activities (CEA analytic group)' by Alain Hanssens et al. 'Analysis of

  7. THE DETECTION OF A HOT MOLECULAR CORE IN THE LARGE MAGELLANIC CLOUD WITH ALMA

    International Nuclear Information System (INIS)

    Shimonishi, Takashi; Onaka, Takashi; Kawamura, Akiko; Aikawa, Yuri

    2016-01-01

    We report the first detection of a hot molecular core outside our Galaxy based on radio observations with ALMA toward a high-mass young stellar object (YSO) in a nearby low metallicity galaxy, the Large Magellanic Cloud (LMC). Molecular emission lines of CO, C 17 O, HCO + , H 13 CO + , H 2 CO, NO, SiO, H 2 CS, 33 SO, 32 SO 2 , 34 SO 2 , and 33 SO 2 are detected from a compact region (∼0.1 pc) associated with a high-mass YSO, ST11. The temperature of molecular gas is estimated to be higher than 100 K based on rotation diagram analysis of SO 2 and 34 SO 2 lines. The compact source size, warm gas temperature, high density, and rich molecular lines around a high-mass protostar suggest that ST11 is associated with a hot molecular core. We find that the molecular abundances of the LMC hot core are significantly different from those of Galactic hot cores. The abundances of CH 3 OH, H 2 CO, and HNCO are remarkably lower compared to Galactic hot cores by at least 1–3 orders of magnitude. We suggest that these abundances are characterized by the deficiency of molecules whose formation requires the hydrogenation of CO on grain surfaces. In contrast, NO shows a high abundance in ST11 despite the notably low abundance of nitrogen in the LMC. A multitude of SO 2 and its isotopologue line detections in ST11 imply that SO 2 can be a key molecular tracer of hot core chemistry in metal-poor environments. Furthermore, we find molecular outflows around the hot core, which is the second detection of an extragalactic protostellar outflow. In this paper, we discuss the physical and chemical characteristics of a hot molecular core in the low metallicity environment.

  8. Color Changing Hydrogen Sensors

    Science.gov (United States)

    Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

    2015-01-01

    During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous

  9. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Vigeholm, B.; Kjøller, John; Larsen, Bent

    1980-01-01

    The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...... that the particles do not disintegrate is explained by a sintering process at the working temperatures. Exposure to air does not impair the sorption ability; on the contrary, it appears that surface oxidation plays an important role in the reaction. Some handling problems, e.g. the reaction of the hydride with water...

  10. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M; Lien, S; Weaver, P F

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  11. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M.; Lien, S.; Weaver, P.F.

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  12. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1983-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure, particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  13. National hydrogen energy roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-11-01

    This report was unveiled by Energy Secretary Spencer Abraham in November 2002 and provides a blueprint for the coordinated, long-term, public and private efforts required for hydrogen energy development. Based on the results of the government-industry National Hydrogen Energy Roadmap Workshop, held in Washington, DC on April 2-3, 2002, it displays the development of a roadmap for America's clean energy future and outlines the key barriers and needs to achieve the hydrogen vision goals defined in

  14. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1981-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure , particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  15. Uncertainties in hydrogen combustion

    International Nuclear Information System (INIS)

    Stamps, D.W.; Wong, C.C.; Nelson, L.S.

    1988-01-01

    Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

  16. Chemochromic Hydrogen Leak Detectors

    Science.gov (United States)

    Roberson, Luke; Captain, Janine; Williams, Martha; Smith, Trent; Tate, LaNetra; Raissi, Ali; Mohajeri, Nahid; Muradov, Nazim; Bokerman, Gary

    2009-01-01

    At NASA, hydrogen safety is a key concern for space shuttle processing. Leaks of any level must be quickly recognized and addressed due to hydrogen s lower explosion limit. Chemo - chromic devices have been developed to detect hydrogen gas in several embodiments. Because hydrogen is odorless and colorless and poses an explosion hazard, there is an emerging need for sensors to quickly and accurately detect low levels of leaking hydrogen in fuel cells and other advanced energy- generating systems in which hydrogen is used as fuel. The device incorporates a chemo - chromic pigment into a base polymer. The article can reversibly or irreversibly change color upon exposure to hydrogen. The irreversible pigment changes color from a light beige to a dark gray. The sensitivity of the pigment can be tailored to its application by altering its exposure to gas through the incorporation of one or more additives or polymer matrix. Furthermore, through the incorporation of insulating additives, the chemochromic sensor can operate at cryogenic temperatures as low as 78 K. A chemochromic detector of this type can be manufactured into any feasible polymer part including injection molded plastic parts, fiber-spun textiles, or extruded tapes. The detectors are simple, inexpensive, portable, and do not require an external power source. The chemochromic detectors were installed and removed easily at the KSC launch pad without need for special expertise. These detectors may require an external monitor such as the human eye, camera, or electronic detector; however, they could be left in place, unmonitored, and examined later for color change to determine whether there had been exposure to hydrogen. In one type of envisioned application, chemochromic detectors would be fabricated as outer layers (e.g., casings or coatings) on high-pressure hydrogen storage tanks and other components of hydrogen-handling systems to provide visible indications of hydrogen leaks caused by fatigue failures or

  17. Biological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Biological hydrogen production can be accomplished by either thermochemical (gasification) conversion of woody biomass and agricultural residues or by microbiological processes that yield hydrogen gas from organic wastes or water. Biomass gasification is a well established technology; however, the synthesis gas produced, a mixture of CO and H{sub 2}, requires a shift reaction to convert the CO to H{sub 2}. Microbiological processes can carry out this reaction more efficiently than conventional catalysts, and may be more appropriate for the relatively small-scale of biomass gasification processes. Development of a microbial shift reaction may be a near-term practical application of microbial hydrogen production.

  18. Biomimetic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Krassen, Henning

    2009-05-15

    Hydrogenases catalyze the reduction of protons to molecular hydrogen with outstanding efficiency. An electrode surface which is covered with active hydrogenase molecules becomes a promising alternative to platinum for electrochemical hydrogen production. To immobilize the hydrogenase on the electrode, the gold surface was modified by heterobifunctional molecules. A thiol headgroup on one side allowed the binding to the gold surface and the formation of a self-assembled monolayer. The other side of the molecules provided a surface with a high affinity for the hydrogenase CrHydA1 from Chlamydomonas reinhardtii. With methylviologen as a soluble energy carrier, electrons were transferred from carboxy-terminated electrodes to CrHydA1 and conducted to the active site (H-cluster), where they reduce protons to molecular hydrogen. A combined approach of surface-enhanced infrared absorption spectroscopy, gas chromatography, and surface plasmon resonance allowed quantifying the hydrogen production on a molecular level. Hydrogen was produced with a rate of 85 mol H{sub 2} min{sup -1} mol{sup -1}. On a 1'- benzyl-4,4'-bipyridinum (BBP)-terminated surface, the electrons were mediated by the monolayer and no soluble electron carrier was necessary to achieve a comparable hydrogen production rate (approximately 50% of the former system). The hydrogen evolution potential was determined to be -335 mV for the BBP-bound hydrogenase and -290 mV for the hydrogenase which was immobilized on a carboxy-terminated mercaptopropionic acid SAM. Therefore, both systems significantly reduce the hydrogen production overpotential and allow electrochemical hydrogen production at an energy level which is close to the commercially applied platinum electrodes (hydrogen evolution potential of -270 mV). In order to couple hydrogen production and photosynthesis, photosystem I (PS1) from Synechocystis PCC 6803 and membrane-bound hydrogenase (MBH) from Ralstonia eutropha were bound to each other

  19. Production of hydrogen from organic waste via hydrogen sulfide

    International Nuclear Information System (INIS)

    McMahon, M.; Davis, B.R.; Roy, A.; Daugulis, A.

    2007-01-01

    In this paper an integrated process is proposed that converts organic waste to hydrogen via hydrogen sulphide. The designed bioreactor has achieved high volumetric productivities comparable to methanogenic bioreactors. Proposed process has advantages of bio-methane production and is more resilient to process upset. Thermochemical conversion of hydrogen sulphide to hydrogen is exothermic and also requires smaller plant infrastructure

  20. Hot flashes and sleep in women.

    Science.gov (United States)

    Moe, Karen E

    2004-12-01

    Sleep disturbances during menopause are often attributed to nocturnal hot flashes and 'sweats' associated with changing hormone patterns. This paper is a comprehensive critical review of the research on the relationship between sleep disturbance and hot flashes in women. Numerous studies have found a relationship between self-reported hot flashes and sleep complaints. However, hot flash studies using objective sleep assessment techniques such as polysomnography, actigraphy, or quantitative analysis of the sleep EEG are surprisingly scarce and have yielded somewhat mixed results. Much of this limited evidence suggests that hot flashes are associated with objectively identified sleep disruption in at least some women. At least some of the negative data may be due to methodological issues such as reliance upon problematic self-reports of nocturnal hot flashes and a lack of concurrent measures of hot flashes and sleep. The recent development of a reliable and non-intrusive method for objectively identifying hot flashes during the night should help address the need for substantial additional research in this area. Several areas of clinical relevance are described, including the effects of discontinuing combined hormone therapy (estrogen plus progesterone) or estrogen-only therapy, the possibility of hot flashes continuing for many years after menopause, and the link between hot flashes and depression.

  1. Hot wire radicals and reactions

    International Nuclear Information System (INIS)

    Zheng Wengang; Gallagher, Alan

    2006-01-01

    Threshold ionization mass spectroscopy is used to measure radical (and stable gas) densities at the substrate of a tungsten hot wire (HW) reactor. We report measurements of the silane reaction probability on the HW and the probability of Si and H release from the HW. We describe a model for the atomic H release, based on the H 2 dissociation model. We note major variations in silicon-release, with dependence on prior silane exposure. Measured radical densities versus silane pressure yield silicon-silane and H-silane reaction rate coefficients, and the dominant radical fluxes to the substrate

  2. Hot moons and cool stars

    Directory of Open Access Journals (Sweden)

    Heller René

    2013-04-01

    Full Text Available The exquisite photometric precision of the Kepler space telescope now puts the detection of extrasolar moons at the horizon. Here, we firstly review observational and analytical techniques that have recently been proposed to find exomoons. Secondly, we discuss the prospects of characterizing potentially habitable extrasolar satellites. With moons being much more numerous than planets in the solar system and with most exoplanets found in the stellar habitable zone being gas giants, habitable moons could be as abundant as habitable planets. However, satellites orbiting planets in the habitable zones of cool stars will encounter strong tidal heating and likely appear as hot moons.

  3. Molecular hydrogen emission from cold condensations in NGC 2440

    International Nuclear Information System (INIS)

    Reay, N.K.; Walton, N.A.

    1988-01-01

    Observations are reported of the ν = 1-0 S(1) line of molecular hydrogen in the high-excitation planetary nebula NGC 2440. The emission is particularly strong at the positions of the two bright condensations which lie well within the H II region and close to the position of the very hot T ≅ 350 000 K central star. The emission is consistent with an excited molecular hydrogen mass of ≅ 2-4 x 10 -5 solar mass in the condensations, and the total mass of excited molecular hydrogen associated with the H II region is estimated to be ≅ 6.1 x 10 -3 solar mass. We show that radiation pressure from the central star is insufficient to excite the S(1) line emission. (author)

  4. Hydrogen by water electrolysis

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Hydrogen production by water electrolysis (aqueous solution of potassium hydroxide) is shortly presented with theoretical aspects (thermodynamics and kinetics), and components of the electrolytic cell (structural materials, cathodes, anodes, diaphragms), and examples of industrial processes. (A.B.). 4 figs

  5. Nanomaterials for Hydrogen Storage

    Indian Academy of Sciences (India)

    concepts transferred from the gaseous state. Separation of a ... molecular mass to that calculated by colligative methods. It is important in ... namics is vital in the design and optimization of the materials for hydrogen ... vehicular applications.

  6. Hydrogen storage compositions

    Science.gov (United States)

    Li, Wen; Vajo, John J.; Cumberland, Robert W.; Liu, Ping

    2011-04-19

    Compositions for hydrogen storage and methods of making such compositions employ an alloy that exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The composition includes a ternary alloy including magnesium, boron and a metal and a metal hydride. The ternary alloy and the metal hydride are present in an amount sufficient to render the composition capable of hydrogen storage. The molar ratio of the metal to magnesium and boron in the alloy is such that the alloy exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The hydrogen storage composition is prepared by combining magnesium, boron and a metal to prepare a ternary alloy and combining the ternary alloy with a metal hydride to form the hydrogen storage composition.

  7. Hydrogen Fire Spectroscopy Issues

    Data.gov (United States)

    National Aeronautics and Space Administration — The detection of hydrogen fires is important to the aerospace community. The National Aeronautics and Space Administration (NASA) has devoted significant effort to...

  8. Canadian hydrogen strategies

    International Nuclear Information System (INIS)

    Fairlie, M.; Scepanovic, V.; Dube, J.; Hammerli, M.; Taylor, J.

    2004-01-01

    'Full text:' In May of 2004, industry and government embarked on a process to create a strategic plan for development of the 'hydrogen economy' in Canada. The process was undertaken to determine how the development and commercialization of hydrogen technologies could be accelerated to yield a 'visible' reduction in greenhouse gases within the timeframe of Kyoto, while establishing a direction that addresses the necessity of far greater reductions in the future. Starting with a meeting of twenty seven experts drawn from the hydrogen technology, energy and transportation industries and government, a vision and mission for the planning process was developed. Two months later a second meeting was held with a broader group of stakeholders to develop hydrogen transition strategies that could achieve the mission, and from identifying the barriers and enablers for these strategies, an action plan was created. This paper reviews the results from this consultation process and discusses next steps. (author)

  9. Hydrogen in titanium alloys

    International Nuclear Information System (INIS)

    Wille, G.W.; Davis, J.W.

    1981-04-01

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 500 0 C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 150 0 C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement

  10. Florida Hydrogen Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Block, David L

    2013-06-30

    The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety

  11. Hydrogen environment embrittlement

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1975-01-01

    Exposure of many metals to gaseous hydrogen causes losses in elongation, reduction of area, and fracture toughness, and causes increases in slow crack growth rate or fatigue life compared with values obtained in air or vacuum. Hydrogen pressure, temperature, and purity significantly influence deleterious effects. The strength and structural characteristics of the metal influence the degradation of its properties by hydrogen. Several theories have been proposed to explain the loss of properties in hydrogen, but none has gained wide acceptance. The embrittlement mechanism and the role of diffusion are, therefore, open questions and need more quantitative experimental data both to test the proposed theories and to allow the development of realistic preventive measures. (U.S.)

  12. Hydrogen perspectives in Japan

    International Nuclear Information System (INIS)

    Furutani, H.

    2000-01-01

    Hydrogen energy is considered to present a potential effective options for achieving the greenhouse gas minimization. The MITI (Ministry of International Trade and Industry) of Japanese Government is promoting the WE-NET (World Energy Network System) Project which envisions (1) construction of a global energy network for effective supply, transportation, storage and utilization of renewable energy using hydrogen as an energy carrier as a long-term options of sustainable energy economy, and (2) promotion of market entry of hydrogen energy in near and/or mid future even before construction of a WE-NET system. In this paper, I would like to report how far the hydrogen energy technology development addressed under Phase I has progressed, and describe the outline of the Phase II Plan. (author)

  13. Hydrogen permeability through metals

    International Nuclear Information System (INIS)

    Pisarev, A.A.; Tsvetkov, I.V.; Marenkov, E.D.; Yarko, S.S.

    2011-01-01

    The mechanisms of hydrogen permeability through one-layer and multi-layer membranes are considered. The effect of surface roughness, crystal defects, cracks and pores is described. Mathematical description of the processes is given [ru

  14. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.E.; Miller, E.; Misra, A. [Univ. of Hawaii, Honolulu, HI (United States)

    1996-10-01

    The large-scale production of hydrogen utilizing energy provided by a renewable source to split water is one of the most ambitious long-term goals of the U.S. Department of Energy`s Hydrogen Program. One promising option to meet this goal is direct photoelectrolysis in which light absorbed by semiconductor-based photoelectrodes produces electrical power internally to split water into hydrogen and oxygen. Under this program, direct solar-to-chemical conversion efficiencies as high as 7.8 % have been demonstrated using low-cost, amorphous-silicon-based photoelectrodes. Detailed loss analysis models indicate that solar-to-chemical conversion greater than 10% can be achieved with amorphous-silicon-based structures optimized for hydrogen production. In this report, the authors describe the continuing progress in the development of thin-film catalytic/protective coatings, results of outdoor testing, and efforts to develop high efficiency, stable prototype systems.

  15. Hydrogenizing oils, asphalts, etc

    Energy Technology Data Exchange (ETDEWEB)

    1925-03-14

    The hydrogenation of carbonaceous solids in presence of combined sulfur, e.g., sulfides as described in the parent specification is applied to the treatment of rock oils, shale oils, resins, ozokerite, asphalt, and the like, or fractions, residues, or acid sludge or other conversion products thereof, alone or mixed. Preferably the hydrogen or other reducing gas is in excess and under pressure, and is either circuited or led through a series of treatment vessels, hydrogen being added for that used. In an example, residues from American crude oil are passed continuously with hydrogen at 200 atmospheres and 450 to 500/sup 0/C over pressed precipitated cobalt sulfide, the issuing gases being cooled to condense the light oil produced.

  16. Selective hydrogen atom abstraction by hydrogen atoms in photolysis and radiolysis of alkane mixtures at 770 K

    International Nuclear Information System (INIS)

    Miyazaki, T.; Kinugawa, K.; Eguchi, M.; Guedes, S.M.L.

    1977-01-01

    Selective hydrogen atom abstraction reaction by H atoms, has been found in Isobutane, 2,2,3,3-tetramethylbutane(TMB), cyclopropane matrices besides neopentane matrix. The selective hydrogen atom abstraction reaction in neopentane-isobutane mixture is affected by the difference of kinetic energies of H atoms. The reaction occurs more favorably with decreasing the kinetic energy of H atoms. Competitive reaction between c-C 6 H 12 and Hi for H atoms has been studied in the radiolysis and photolysis of neo-C 5 H 12 HI mixture at 77 K. The rate constants of these reactions in neopentane matrix are quite different from these of thermal H atom reaction, but similar to those of hot H atom reaction. Importance of the selective hydrogen atom abstraction reaction by H atoms is pointed out in the radical formation in the radiolysis of pure TMB at 77 K [pt

  17. The hydrogen issue.

    Science.gov (United States)

    Armaroli, Nicola; Balzani, Vincenzo

    2011-01-17

    Hydrogen is often proposed as the fuel of the future, but the transformation from the present fossil fuel economy to a hydrogen economy will need the solution of numerous complex scientific and technological issues, which will require several decades to be accomplished. Hydrogen is not an alternative fuel, but an energy carrier that has to be produced by using energy, starting from hydrogen-rich compounds. Production from gasoline or natural gas does not offer any advantage over the direct use of such fuels. Production from coal by gasification techniques with capture and sequestration of CO₂ could be an interim solution. Water splitting by artificial photosynthesis, photobiological methods based on algae, and high temperatures obtained by nuclear or concentrated solar power plants are promising approaches, but still far from practical applications. In the next decades, the development of the hydrogen economy will most likely rely on water electrolysis by using enormous amounts of electric power, which in its turn has to be generated. Producing electricity by burning fossil fuels, of course, cannot be a rational solution. Hydroelectric power can give but a very modest contribution. Therefore, it will be necessary to generate large amounts of electric power by nuclear energy of by renewable energies. A hydrogen economy based on nuclear electricity would imply the construction of thousands of fission reactors, thereby magnifying all the problems related to the use of nuclear energy (e.g., safe disposal of radioactive waste, nuclear proliferation, plant decommissioning, uranium shortage). In principle, wind, photovoltaic, and concentrated solar power have the potential to produce enormous amounts of electric power, but, except for wind, such technologies are too underdeveloped and expensive to tackle such a big task in a short period of time. A full development of a hydrogen economy needs also improvement in hydrogen storage, transportation and distribution

  18. Nuclear power and hydrogen

    International Nuclear Information System (INIS)

    Welch, Robert.

    1982-06-01

    Ontario has been using CANDU reactors to produce electricity since 1962. The province does not have an electricity shortage, but it does have a shortage of liquid fuels. The government of Ontario is encouraging research into the production of hydrogen using electricity generated by a dedicated nuclear plant, and the safe and economical use of hydrogen both in the production of synthetic petroleum fuels and as a fuel in its own right

  19. Purdue Hydrogen Systems Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Jay P Gore; Robert Kramer; Timothee L Pourpoint; P. V. Ramachandran; Arvind Varma; Yuan Zheng

    2011-12-28

    The Hydrogen Systems Laboratory in a unique partnership between Purdue University's main campus in West Lafayette and the Calumet campus was established and its capabilities were enhanced towards technology demonstrators. The laboratory engaged in basic research in hydrogen production and storage and initiated engineering systems research with performance goals established as per the USDOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program. In the chemical storage and recycling part of the project, we worked towards maximum recycling yield via novel chemical selection and novel recycling pathways. With the basic potential of a large hydrogen yield from AB, we used it as an example chemical but have also discovered its limitations. Further, we discovered alternate storage chemicals that appear to have advantages over AB. We improved the slurry hydrolysis approach by using advanced slurry/solution mixing techniques. We demonstrated vehicle scale aqueous and non-aqueous slurry reactors to address various engineering issues in on-board chemical hydrogen storage systems. We measured the thermal properties of raw and spent AB. Further, we conducted experiments to determine reaction mechanisms and kinetics of hydrothermolysis in hydride-rich solutions and slurries. We also developed a continuous flow reactor and a laboratory scale fuel cell power generation system. The biological hydrogen production work summarized as Task 4.0 below, included investigating optimal hydrogen production cultures for different substrates, reducing the water content in the substrate, and integrating results from vacuum tube solar collector based pre and post processing tests into an enhanced energy system model. An automated testing device was used to finalize optimal hydrogen production conditions using statistical procedures. A 3 L commercial fermentor (New Brunswick, BioFlo 115) was used to finalize testing of larger samples and to consider issues related to scale up

  20. A Rechargeable Hydrogen Battery.

    Science.gov (United States)

    Christudas Dargily, Neethu; Thimmappa, Ravikumar; Manzoor Bhat, Zahid; Devendrachari, Mruthunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Gautam, Manu; Shafi, Shahid Pottachola; Thotiyl, Musthafa Ottakam

    2018-04-27

    We utilize proton-coupled electron transfer in hydrogen storage molecules to unlock a rechargeable battery chemistry based on the cleanest chemical energy carrier molecule, hydrogen. Electrochemical, spectroscopic, and spectroelectrochemical analyses evidence the participation of protons during charge-discharge chemistry and extended cycling. In an era of anthropogenic global climate change and paramount pollution, a battery concept based on a virtually nonpolluting energy carrier molecule demonstrates distinct progress in the sustainable energy landscape.

  1. Hydrogen recovery process

    Science.gov (United States)

    Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

    2000-01-01

    A treatment process for a hydrogen-containing off-gas stream from a refinery, petrochemical plant or the like. The process includes three separation steps: condensation, membrane separation and hydrocarbon fraction separation. The membrane separation step is characterized in that it is carried out under conditions at which the membrane exhibits a selectivity in favor of methane over hydrogen of at least about 2.5.

  2. Purdue Hydrogen Systems Laboratory

    International Nuclear Information System (INIS)

    Gore, Jay P.; Kramer, Robert; Pourpoint, Timothee L.; Ramachandran, P.V.; Varma, Arvind; Zheng, Yuan

    2011-01-01

    The Hydrogen Systems Laboratory in a unique partnership between Purdue University's main campus in West Lafayette and the Calumet campus was established and its capabilities were enhanced towards technology demonstrators. The laboratory engaged in basic research in hydrogen production and storage and initiated engineering systems research with performance goals established as per the USDOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program. In the chemical storage and recycling part of the project, we worked towards maximum recycling yield via novel chemical selection and novel recycling pathways. With the basic potential of a large hydrogen yield from AB, we used it as an example chemical but have also discovered its limitations. Further, we discovered alternate storage chemicals that appear to have advantages over AB. We improved the slurry hydrolysis approach by using advanced slurry/solution mixing techniques. We demonstrated vehicle scale aqueous and non-aqueous slurry reactors to address various engineering issues in on-board chemical hydrogen storage systems. We measured the thermal properties of raw and spent AB. Further, we conducted experiments to determine reaction mechanisms and kinetics of hydrothermolysis in hydride-rich solutions and slurries. We also developed a continuous flow reactor and a laboratory scale fuel cell power generation system. The biological hydrogen production work summarized as Task 4.0 below, included investigating optimal hydrogen production cultures for different substrates, reducing the water content in the substrate, and integrating results from vacuum tube solar collector based pre and post processing tests into an enhanced energy system model. An automated testing device was used to finalize optimal hydrogen production conditions using statistical procedures. A 3 L commercial fermentor (New Brunswick, BioFlo 115) was used to finalize testing of larger samples and to consider issues related to scale up. Efforts

  3. Nanostructured materials for hydrogen storage

    Science.gov (United States)

    Williamson, Andrew J.; Reboredo, Fernando A.

    2007-12-04

    A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

  4. Hydrogen Delivery Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The mission of the Hydrogen Delivery Technical Team (HDTT) is to enable the development of hydrogen delivery technologies, which will allow for fuel cell competitiveness with gasoline and hybrid technologies by achieving an as-produced, delivered, and dispensed hydrogen cost of $2-$4 per gallon of gasoline equivalent of hydrogen.

  5. Diffusion of hydrogen in yttrium

    International Nuclear Information System (INIS)

    Vorobyov, V.V.; Ryabchikov, L.N.

    1966-01-01

    In this work the diffusion coefficients of hydrogen in yttrium were determined from the rate at which the hydrogen was released from yttrium samples under a vacuum at temperatures of 450 to 850 0 C and from the quantity of hydrogen retained by yttrium at hydrogen pressures below 5 x 10 - 4 mm Hg in the same temperature range

  6. Hot tearing studies in AA5182

    Science.gov (United States)

    van Haaften, W. M.; Kool, W. H.; Katgerman, L.

    2002-10-01

    One of the major problems during direct chill (DC) casting is hot tearing. These tears initiate during solidification of the alloy and may run through the entire ingot. To study the hot tearing mechanism, tensile tests were carried out in semisolid state and at low strain rates, and crack propagation was studied in situ by scanning electron microscopy (SEM). These experimentally induced cracks were compared with hot tears developed in an AA5182 ingot during a casting trial in an industrial research facility. Similarities in the microstructure of the tensile test specimens and the hot tears indicate that hot tearing can be simulated by performing tensile tests at semisolid temperatures. The experimental data were compared with existing hot tearing models and it was concluded that the latter are restricted to relatively high liquid fractions because they do not take into account the existence of solid bridges in the crack.

  7. Examining hydrogen transitions.

    Energy Technology Data Exchange (ETDEWEB)

    Plotkin, S. E.; Energy Systems

    2007-03-01

    This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals of these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.

  8. Hydrogen and nuclear power

    International Nuclear Information System (INIS)

    Holt, D.J.

    1976-12-01

    This study examines the influence that the market demand for hydrogen might have on the development of world nuclear capacity over the next few decades. In a nuclear economy, hydrogen appears to be the preferred energy carrier over electricity for most purposes, due to its ready substitution and usage for all energy needs, as well as its low transmission costs. The economic factors upon which any transition to hydrogen fuelling will be largely based are seen to be strongly dependent on the form of future energy demand, the energy resource base, and on the status of technology. Accordingly, the world energy economy is examined to identify the factors which might affect the future demand price structure for energy, and a survey of current estimates of world energy resources, particularly oil, gas, nuclear, and solar, is presented. Current and projected technologies for production and utilization of hydrogen are reviewed, together with rudimentary cost estimates. The relative economics are seen to favour production of hydrogen from fossil fuels far into the foreseeable future, and a clear case emerges for high temperature nuclear reactors in such process heat applications. An expanding industrial market for hydrogen, and near term uses in steelmaking and aircraft fuelling are foreseen, which would justify an important development effort towards nuclear penetration of that market. (author)

  9. Electrochemical hydrogen Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Digby Macdonald

    2010-08-09

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not

  10. Metallic hydrogen research

    International Nuclear Information System (INIS)

    Burgess, T.J.; Hawke, R.S.

    1978-01-01

    Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm 3 and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures

  11. Hydrogen isotope technology

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Hydrogen pumping speeds on panels of molecular sieve types 5A and Na-Y were compared for a variety of sieve (and chevron) temperatures between 10 and 30 K. Although pumping speeds declined with time, probably because of the slow diffusion of hydrogen from the surface of the sieve crystals into the internal regions, the different sieve materials and operating conditions could be compared using time-averaged pump speeds. The (average) pumping speeds declined with increasing temperature. Under some conditions, the Na-Y sieve performed much better than the 5A sieve. Studies of the effect of small concentrations (approx. 4%) of hydrogen on helium pumping indicate that compound cryopumps in fusion reactors will not have to provide complete screening of hydrogen from helium panels. The concentrations of hydrogen did not lower effective helium pumping speeds or shorten the helium operating period between instabilities. Studies of tritium recovery from blankets of liquid lithium focused on design and construction of a flowing-lithium test system and on ultimate removal of tritium from yttrium sorbents. At 505 0 C, tritium release from yttrium behaves as a diffusion-controlled process, but the release rates are very low. Apparently, higher temperatures will be required for effective sorbent regeneration. An innovative technique for separating hydrogen isotopes by using bipolar electrolysis with permeable electrodes was analyzed to determine its potential usefulness in multistage separation

  12. Electrochemical hydrogen Storage Systems

    International Nuclear Information System (INIS)

    Macdonald, Digby

    2010-01-01

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not described in the

  13. Active control of magneto-hydrodynamic instabilities in hot plasmas

    CERN Document Server

    2015-01-01

    During the past century, world-wide energy consumption has risen dramatically, which leads to a quest for new energy sources. Fusion of hydrogen atoms in hot plasmas is an attractive approach to solve the energy problem, with abundant fuel, inherent safety and no long-lived radioactivity.  However, one of the limits on plasma performance is due to the various classes of magneto-hydrodynamic instabilities that may occur. The physics and control of these instabilities in modern magnetic confinement fusion devices is the subject of this book. Written by foremost experts, the contributions will provide valuable reference and up-to-date research reviews for "old hands" and newcomers alike.

  14. Menopausal Hot Flashes and White Matter Hyperintensities

    Science.gov (United States)

    Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

    2015-01-01

    Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

  15. Effect of energetic electrons on dust charging in hot cathode filament discharge

    Science.gov (United States)

    Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.

    2011-03-01

    The effect of energetic electrons on dust charging for different types of dust is studied in hydrogen plasma. The hydrogen plasma is produced by hot cathode filament discharge method in a dusty plasma device. A full line cusped magnetic field cage is used to confine the plasma elements. To study the plasma parameters for various discharge conditions, a cylindrical Langmuir probe having 0.15 mm diameter and 10.0 mm length is used. An electronically controlled dust dropper is used to drop the dust particles into the plasma. For different discharge conditions, the dust current is measured using a Faraday cup connected to an electrometer. The effect of secondary emission as well as discharge voltage on charging of dust grains in hydrogen plasma is studied with different dust.

  16. Effect of energetic electrons on dust charging in hot cathode filament discharge

    International Nuclear Information System (INIS)

    Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.

    2011-01-01

    The effect of energetic electrons on dust charging for different types of dust is studied in hydrogen plasma. The hydrogen plasma is produced by hot cathode filament discharge method in a dusty plasma device. A full line cusped magnetic field cage is used to confine the plasma elements. To study the plasma parameters for various discharge conditions, a cylindrical Langmuir probe having 0.15 mm diameter and 10.0 mm length is used. An electronically controlled dust dropper is used to drop the dust particles into the plasma. For different discharge conditions, the dust current is measured using a Faraday cup connected to an electrometer. The effect of secondary emission as well as discharge voltage on charging of dust grains in hydrogen plasma is studied with different dust.

  17. JUSTIFICATION FOR A LIMIT OF 15 PERCENT HYDROGEN IN A 55-GALLON DRUM

    International Nuclear Information System (INIS)

    MARUSICH, R.M.

    2007-01-01

    The concentration of 15% hydrogen in air in a waste drum is used as the concentration at which the drum remains intact in the case of a deflagration. The following describes what could happen to the drum if 15% hydrogen or more in air were ignited. Table 2 of the Savannah River report WSRC-TR-90-165 ''TRU Drum Hydrogen Explosion Tests'' provides the results of tests performed in 55-gallon drums filled with hydrogen and air mixtures. The hydrogen-air mixtures were ignited by a hot-wire igniter. The results of the tests are shown in Table 1. They concluded that drums can withstand deflagration involving hydrogen concentration up to 15% hydrogen. Testing was performed at Idaho Falls and documented in a letter from RH Beers, Waste Technology Programs Division, EG and G Idaho, to CP Gertz, Radioactive Waste Technology Branch, DOE dated Sept. 29, 1983. In these tests, 55-gallon drums were filled with hydrogen-air mixtures which were ignited. The results in Table 2.2 showed that ignition for drums containing 11% and 14% hydrogen, the drum lid remained on the drum. Ignition in drum with 30% hydrogen resulted in lid loss. It is concluded from the results of these two tests that, for uncorroded drums, a 15% hydrogen in air mixture will not result in loss of drum integrity (i.e., lid remains on, walls remain intact). The drum walls however, may be thinned due to corrosion. The effect of the deflagration on thinner walls is assessed next. Assume a 15% hydrogen in air mixture exists in a drum. The pressure assuming adiabatic isochoric complete combustion (AICC) conditions is 69 psig (using the same deflagration pressure calculation method as in HNF-19492, ''Revised Hydrogen Deflagration Analysis which got 82 psig for 20% hydrogen in air)

  18. An infrared diagnostic for magnetism in hot stars

    Science.gov (United States)

    Oksala, M. E.; Grunhut, J. H.; Kraus, M.; Borges Fernandes, M.; Neiner, C.; Condori, C. A. H.; Campagnolo, J. C. N.; Souza, T. B.

    2015-06-01

    Magnetospheric observational proxies are used for indirect detection of magnetic fields in hot stars in the X-ray, UV, optical, and radio wavelength ranges. To determine the viability of infrared (IR) hydrogen recombination lines as a magnetic diagnostic for these stars, we have obtained low-resolution (R~ 1200), near-IR spectra of the known magnetic B2V stars HR 5907 and HR 7355, taken with the Ohio State Infrared Imager/Spectrometer (OSIRIS) attached to the 4.1 m Southern Astrophysical Research (SOAR) Telescope. Both stars show definite variable emission features in IR hydrogen lines of the Brackett series, with similar properties as those found in optical spectra, including the derived location of the detected magnetospheric plasma. These features also have the added advantage of a lowered contribution of stellar flux at these wavelengths, making circumstellar material more easily detectable. IR diagnostics will be useful for the future study of magnetic hot stars, to detect and analyze lower-density environments, and to detect magnetic candidates in areas obscured from UV and optical observations, increasing the number of known magnetic stars to determine basic formation properties and investigate the origin of their magnetic fields. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the US National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  19. Microplasticity in hot-pressed beryllium

    International Nuclear Information System (INIS)

    Plane, D.C.; Bonfield, W.

    1977-01-01

    Closed hysteresis loops measured in the microstrain region of hot pressed, commercially pure, polycrystalline beryllium are correlated with a dislocation - impurity atom, energy dissipating mechanism. (author)

  20. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  1. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  2. Hydrogen Storage In Nanostructured Materials

    OpenAIRE

    Assfour, Bassem

    2011-01-01

    Hydrogen is an appealing energy carrier for clean energy use. However, storage of hydrogen is still the main bottleneck for the realization of an energy economy based on hydrogen. Many materials with outstanding properties have been synthesized with the aim to store enough amount of hydrogen under ambient conditions. Such efforts need guidance from material science, which includes predictive theoretical tools. Carbon nanotubes were considered as promising candidates for hydrogen storag...

  3. Hydrogen storage and generation system

    Science.gov (United States)

    Dentinger, Paul M.; Crowell, Jeffrey A. W.

    2010-08-24

    A system for storing and generating hydrogen generally and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses the beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

  4. California Hydrogen Infrastructure Project

    Energy Technology Data Exchange (ETDEWEB)

    Heydorn, Edward C

    2013-03-12

    Air Products and Chemicals, Inc. has completed a comprehensive, multiyear project to demonstrate a hydrogen infrastructure in California. The specific primary objective of the project was to demonstrate a model of a real-world retail hydrogen infrastructure and acquire sufficient data within the project to assess the feasibility of achieving the nation's hydrogen infrastructure goals. The project helped to advance hydrogen station technology, including the vehicle-to-station fueling interface, through consumer experiences and feedback. By encompassing a variety of fuel cell vehicles, customer profiles and fueling experiences, this project was able to obtain a complete portrait of real market needs. The project also opened its stations to other qualified vehicle providers at the appropriate time to promote widespread use and gain even broader public understanding of a hydrogen infrastructure. The project engaged major energy companies to provide a fueling experience similar to traditional gasoline station sites to foster public acceptance of hydrogen. Work over the course of the project was focused in multiple areas. With respect to the equipment needed, technical design specifications (including both safety and operational considerations) were written, reviewed, and finalized. After finalizing individual equipment designs, complete station designs were started including process flow diagrams and systems safety reviews. Material quotes were obtained, and in some cases, depending on the project status and the lead time, equipment was placed on order and fabrication began. Consideration was given for expected vehicle usage and station capacity, standard features needed, and the ability to upgrade the station at a later date. In parallel with work on the equipment, discussions were started with various vehicle manufacturers to identify vehicle demand (short- and long-term needs). Discussions included identifying potential areas most suited for hydrogen fueling

  5. Hydrogen, energy of the future?

    International Nuclear Information System (INIS)

    Alleau, Th.

    2007-01-01

    A cheap, non-polluting energy with no greenhouse gas emissions and unlimited resources? This is towards this fantastic future that this book brings us, analyzing the complex but promising question of hydrogen. The scientific and technical aspects of production, transport, storage and distribution raised by hydrogen are thoroughly reviewed. Content: I) Energy, which solutions?: 1 - hydrogen, a future; 2 - hydrogen, a foreseeable solution?; II) Hydrogen, an energy vector: 3 - characteristics of hydrogen (physical data, quality and drawbacks); 4 - hydrogen production (from fossil fuels, from water, from biomass, bio-hydrogen generation); 5 - transport, storage and distribution of hydrogen; 6 - hydrogen cost (production, storage, transport and distribution costs); III) Fuel cells and ITER, utopias?: 7 - molecular hydrogen uses (thermal engines and fuel cells); 8 - hydrogen and fusion (hydrogen isotopes, thermonuclear reaction, ITER project, fusion and wastes); IV) Hydrogen acceptability: 9 - risk acceptability; 10 - standards and regulations; 11 - national, European and international policies about hydrogen; 12 - big demonstration projects in France and in the rest of the world; conclusion. (J.S.)

  6. Future hydrogen markets for large-scale hydrogen production systems

    International Nuclear Information System (INIS)

    Forsberg, Charles W.

    2007-01-01

    The cost of delivered hydrogen includes production, storage, and distribution. For equal production costs, large users (>10 6 m 3 /day) will favor high-volume centralized hydrogen production technologies to avoid collection costs for hydrogen from widely distributed sources. Potential hydrogen markets were examined to identify and characterize those markets that will favor large-scale hydrogen production technologies. The two high-volume centralized hydrogen production technologies are nuclear energy and fossil energy with carbon dioxide sequestration. The potential markets for these technologies are: (1) production of liquid fuels (gasoline, diesel and jet) including liquid fuels with no net greenhouse gas emissions and (2) peak electricity production. The development of high-volume centralized hydrogen production technologies requires an understanding of the markets to (1) define hydrogen production requirements (purity, pressure, volumes, need for co-product oxygen, etc.); (2) define and develop technologies to use the hydrogen, and (3) create the industrial partnerships to commercialize such technologies. (author)

  7. Ionization of Interstellar Hydrogen

    Science.gov (United States)

    Whang, Y. C.

    1996-09-01

    Interstellar hydrogen can penetrate through the heliopause, enter the heliosphere, and may become ionized by photoionization and by charge exchange with solar wind protons. A fluid model is introduced to study the flow of interstellar hydrogen in the heliosphere. The flow is governed by moment equations obtained from integration of the Boltzmann equation over the velocity space. Under the assumption that the flow is steady axisymmetric and the pressure is isotropic, we develop a method of solution for this fluid model. This model and the method of solution can be used to study the flow of neutral hydrogen with various forms of ionization rate β and boundary conditions for the flow on the upwind side. We study the solution of a special case in which the ionization rate β is inversely proportional to R2 and the interstellar hydrogen flow is uniform at infinity on the upwind side. We solve the moment equations directly for the normalized density NH/NN∞, bulk velocity VH/VN∞, and temperature TH/TN∞ of interstellar hydrogen as functions of r/λ and z/λ, where λ is the ionization scale length. The solution is compared with the kinetic theory solution of Lallement et al. The fluid solution is much less time-consuming than the kinetic theory solutions. Since the ionization rate for production of pickup protons is directly proportional to the local density of neutral hydrogen, the high-resolution solution of interstellar neutral hydrogen obtained here will be used to study the global distribution of pickup protons.

  8. Terminal solid solubility of hydrogen in titanium

    International Nuclear Information System (INIS)

    Giroldi, J.P.; Vizcaino, Pablo; Banchik, Abraham David

    2003-01-01

    A Research and Development program to build a data base is currently under progress to support the local titanium fabrication. In the present work the temperature of the Terminal Solid Solubility on dissolution (TSSd) and precipitation (TSSp) of titanium hydrides in the Ti α-phase were both measured in the same thermal cycle with a Differential Scanning Calorimeter (DSC). The local titanium producer (FAESA) provided ASTM grade 1 pure Ti bars of about 2,5 cm in diameter. Samples weighting between 50 to 200 mg were cut with a diamond disc and the parallelepiped faces were all carefully ground with SiC papers, then picked in a HNO 3 plus HF aqueous solution and finally dried out with ethanol and hot air. Pairs of (TSSd, TSSp) values for α + δ → α and α → α + δ transformation temperatures in titanium were determined with the same calorimetric procedure already used to calculate the TSS values in zirconium. Data were taken from the same sample during the heating up and cooling down cycle of the second calorimeter run made with the same rate of 20 C degrees / minute. The Cathodic Charging technique was used to charge the samples at different hydrogen concentrations between the 'as fabricated' value and the concentration corresponding to the eutectoid temperature. A mixture of glycerin and phosphoric acid in a 2:1 ratio and a current density of 0,05 to 0,1 Amp/cm 2 were applied to different samples during 24 to 96 hours to get a wide range of hydrogen concentrations. A homogenization heat treatment at 400 C degrees for 45 minutes -made at open air in an electric furnace- was applied to each sample to dissolve the massive hydrides at the sample surfaces and diffuse them into the bulk of the sample. The hydrogen concentration of each sample was measured after the final calorimetric run using the Extraction Method in Liquid State under an inert atmosphere using a Leco RH-404 model Hydrogen Determinator. The experimental data follows a linear relationship -with a

  9. Summary of the FY 1988 Sunshine Project results. Hydrogen energy; 1988 nendo sunshine keikaku seika hokokusho gaiyoshu. Suiso energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-04-01

    Outlined herein are the results of researches on hydrogen energy as part of the FY 1988 Sunshine Project results. Researches on the techniques for producing hydrogen by electrolysis of water using a polymer electrolyte include development of power-supplying materials for electrolysis at high current density, and basic studies on the electrolysis using an OH ion conducting type polymer electrolyte. Researches on the techniques for producing hydrogen by electrolysis with hot steam include development of the materials, techniques for processing these materials, and electrolysis performance tests. Researches on the techniques for transporting hydrogen by metal hydrides include development of hydrogen-occluding alloys of high bulk density, and techniques for evaluating characteristics of metal hydrides. Researches on the techniques for storing hydrogen include those on alloy molding/processing techniques, hydrogen-storing metallic materials, and new hydrogen-storing materials. Researches on the techniques for utilizing hydrogen include those on energy conversion techniques using hydrogen-occluding alloys, and hydrogen-fueled motors. Researches on the techniques for safety-related measures include those on prevention of embrittlement of the system materials by hydrogen. (NEDO)

  10. Summary of the FY 1989 Sunshine Project results. Hydrogen energy; 1989 nendo sunshine keikaku seika hokokusho gaiyoshu. Suiso energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-04-01

    Outlined herein are the results of researches on hydrogen energy as part of the FY 1989 Sunshine Project results. Researches on the techniques for producing hydrogen by electrolysis of water using a polymer electrolyte include those on the SPE electrolysis at high temperature and current density, and basic studies on the electrolysis using an OH ion conducting type polymer electrolyte. Researches on the techniques for producing hydrogen by electrolysis with hot steam include development of the materials, techniques for processing these materials, and electrolysis performance tests. Researches on the techniques for transporting hydrogen by metal hydrides include development of hydrogen-occluding alloys of high bulk density, and techniques for evaluating characteristics of metal hydrides. Researches on the techniques for storing hydrogen include those on hydrogen-storing metallic materials, alloy molding/processing techniques, and new hydrogen-storing materials. Researches on the techniques for utilizing hydrogen include those on energy conversion techniques using hydrogen-occluding alloys, and hydrogen-fueled motors. Researches on the techniques for safety-related measures include those on prevention of embrittlement of the system materials by hydrogen. (NEDO)

  11. The effect of fan-induced turbulence on the combustion of hydrogen-air mixtures

    International Nuclear Information System (INIS)

    Kumar, R.K.; Tamm, H.

    1984-01-01

    The effect of fan-induced turbulence on the combustion of hydrogen-air mixtures has been studied in a 2.3-m diameter sphere over a hydrogen concentration range of 4 to 42% (by volume). Two fans were used to produce the turbulence, which was measured at various lacations by hot-wire anemometry. For low hydrogen concentrations (< 7%), turbulence increases the rate and extent of combustion; for large turbulence intensities the extent of combustion approaches 100%, and combustion times are reduced by factors of 8 to 10 from those observed under quiescent conditions. At high hydrogen concentrations, the effect of turbulence on combustion time is less pronounced than at low hydrogen concentrations. Flame-generated turbulence has a significant effect on the combustion rate. (orig.)

  12. Handbook of hot atom chemistry

    International Nuclear Information System (INIS)

    Adloff, J.P.; Matsuura, Tatsuo; Yoshihara, Kenji

    1992-01-01

    Hot atom chemistry is an increasingly important field, which has contributed significantly to our understanding of many fundamental processes and reactions. Its techniques have become firmly entrenched in numerous disciplines, such as applied physics, biomedical research, and all fields of chemistry. Written by leading experts, this comprehensive handbook encompasses a broad range of topics. Each chapter comprises a collection of stimulating essays, given an in-depth account of the state-of-the-art of the field, and stressing opportunities for future work. An extensive introduction to the whole area, this book provides unique insight into a vast subject, and a clear delineation of its goals, techniques, and recent findings. It also contains detailed discussions of applications in fields as diverse as nuclear medicine, geochemistry, reactor technology, and the chemistry of comets and interstellar grains. (orig.)

  13. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

    1999-05-11

    A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

  14. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  15. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  16. Hydrogen concentration control utilizing a hydrogen permeable membrane

    International Nuclear Information System (INIS)

    Keating, S.J. Jr.

    1976-01-01

    The concentration of hydrogen in a fluid mixture is controlled to a desired concentration by flowing the fluid through one chamber of a diffusion cell separated into two chambers by a hydrogen permeable membrane. A gradient of hydrogen partial pressure is maintained across the membrane to cause diffusion of hydrogen through the membrane to maintain the concentration of hydrogen in the fluid mixture at the predetermined level. The invention has particular utility for the purpose of injecting into and/or separating hydrogen from the reactor coolant of a nuclear reactor system

  17. Hydrogen molecules and hydrogen-related defects in crystalline silicon

    OpenAIRE

    Fukata, N.; Sasak, S.; Murakami, K.; Ishioka, K.; Nakamura, K. G.; Kitajima, M.; Fujimura, S.; Kikuchi, J.; Haneda, H.

    1997-01-01

    We have found that hydrogen exists in molecular form in crystalline silicon treated with hydrogen atoms in the downstream of a hydrogen plasma. The vibrational Raman line of hydrogen molecules is observed at 4158cm-1 for silicon samples hydrogenated between 180 and 500 °C. The assignment of the Raman line is confirmed by its isotope shift to 2990cm-1 for silicon treated with deuterium atoms. The Raman intensity has a maximum for hydrogenation at 400 °C. The vibrational Raman line of the hydro...

  18. Magnetic liquefier for hydrogen

    International Nuclear Information System (INIS)

    1992-01-01

    This document summarizes work done at the Astronautics Technology Center of the Astronautics Corporation of America (ACA) in Phase 1 of a four phase program leading to the development of a magnetic liquefier for hydrogen. The project involves the design, fabrication, installation, and operation of a hydrogen liquefier providing significantly reduced capital and operating costs, compared to present liquefiers. To achieve this goal, magnetic refrigeration, a recently developed, highly efficient refrigeration technology, will be used for the liquefaction process. Phase 1 project tasks included liquefier conceptual design and analysis, preliminary design of promising configurations, design selection, and detailed design of the selected design. Fabrication drawings and vendor specifications for the selected design were completed during detailed design. The design of a subscale, demonstration magnetic hydrogen liquefier represents a significant advance in liquefaction technology. The cost reductions that can be realized in hydrogen liquefaction in both the subscale and, more importantly, in the full-scale device are expected to have considerable impact on the use of liquid hydrogen in transportation, chemical, and electronic industries. The benefits to the nation from this technological advance will continue to have importance well into the 21st century

  19. The hydrogen laminar jet

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sanz, M. [Departamento de Motopropulsion y Termofluidomecanica, ETSI Aeronauticos, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Rosales, M. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain); Instituto de Innovacion en Mineria y Metalurgia, Avenida del Valle 738, Santiago (Chile); Sanchez, A.L. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain)

    2010-04-15

    Numerical and asymptotic methods are used to investigate the structure of the hydrogen jet discharging into a quiescent air atmosphere. The analysis accounts in particular for the variation of the density and transport properties with composition. The Reynolds number of the flow R{sub j}, based on the initial jet radius a, the density {rho}{sub j} and viscosity {mu}{sub j} of the jet and the characteristic jet velocity u{sub j}, is assumed to take moderately large values, so that the jet remains slender and stable, and can be correspondingly described by numerical integration of the continuity, momentum and species conservation equations written in the boundary-layer approximation. The solution for the velocity and composition in the jet development region of planar and round jets, corresponding to streamwise distances of order R{sub j}a, is computed numerically, along with the solutions that emerge both in the near field and in the far field. The small value of the hydrogen-to-air molecular weight ratio is used to simplify the solution by considering the asymptotic limit of vanishing jet density. The development provides at leading-order explicit analytical expressions for the far-field velocity and hydrogen mass fraction that describe accurately the hydrogen jet near the axis. The information provided can be useful in particular to characterize hydrogen discharge processes from holes and cracks. (author)

  20. Hydrogen Contractors Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Fitzsimmons, Tim [Dept. of Energy (DOE), Washington DC (United States). Office of Basic Energy Sciences. Division of Materials Sciences and Engineering

    2006-05-16

    This volume highlights the scientific content of the 2006 Hydrogen Contractors Meeting sponsored by the Division of Materials Sciences and Engineering (DMS&E) on behalf of the Office of Basic Energy Sciences (BES) of the U. S. Department of Energy (DOE). Hydrogen Contractors Meeting held from May 16-19, 2006 at the Crystal Gateway Marriott Hotel Arlington, Virginia. This meeting is the second in a series of research theme-based Contractors Meetings sponsored by DMS&E held in conjunction with our counterparts in the Office of Energy Efficiency and Renewable Energy (EERE) and the first with the Hydrogen, Fuel Cells and Infrastructure Technologies Program. The focus of this year’s meeting is BES funded fundamental research underpinning advancement of hydrogen storage. The major goals of these research efforts are the development of a fundamental scientific base in terms of new concepts, theories and computational tools; new characterization capabilities; and new materials that could be used or mimicked in advancing capabilities for hydrogen storage.