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Sample records for hydrogen balmer emission

  1. HYDRO2GEN: Non-thermal hydrogen Balmer and Paschen emission in solar flares generated by electron beams

    Science.gov (United States)

    Druett, M. K.; Zharkova, V. V.

    2018-03-01

    Aim. Sharp rises of hard X-ray (HXR) emission accompanied by Hα line profiles with strong red-shifts up to 4 Å from the central wavelength, often observed at the onset of flares with the Specola Solare Ticinese Telescope (STT) and the Swedish Solar Telescope (SST), are not fully explained by existing radiative models. Moreover, observations of white light (WL) and Balmer continuum emission with the Interface Region Imaging Spectrograph (IRISH) reveal strong co-temporal enhancements and are often nearly co-spatial with HXR emission. These effects indicate a fast effective source of excitation and ionisation of hydrogen atoms in flaring atmospheres associated with HXR emission. In this paper, we investigate electron beams as the agents accounting for the observed hydrogen line and continuum emission. Methods: Flaring atmospheres are considered to be produced by a 1D hydrodynamic response to the injection of an electron beam defining their kinetic temperatures, densities, and macro velocities. We simulated a radiative response in these atmospheres using a fully non-local thermodynamic equilibrium (NLTE) approach for a 5-level plus continuum hydrogen atom model, considering its excitation and ionisation by spontaneous, external, and internal diffusive radiation and by inelastic collisions with thermal and beam electrons. Simultaneous steady-state and integral radiative transfer equations in all optically thick transitions (Lyman and Balmer series) were solved iteratively for all the transitions to define their source functions with the relative accuracy of 10-5. The solutions of the radiative transfer equations were found using the L2 approximation. Resulting intensities of hydrogen line and continuum emission were also calculated for Balmer and Paschen series. Results: We find that inelastic collisions with beam electrons strongly increase excitation and ionisation of hydrogen atoms from the chromosphere to photosphere. This leads to an increase in Lyman continuum

  2. Doppler shift measurement of Balmer-alpha line spectrum emission from a plasma in a negative hydrogen ion source

    International Nuclear Information System (INIS)

    Wada, M.; Doi, K.; Kisaki, M.; Nakano, H.; Tsumori, K.; Nishiura, M.

    2015-01-01

    Balmer-α light emission from the extraction region of the LHD one-third ion source has shown a characteristic Doppler broadening in the wavelength spectrum detected by a high resolution spectrometer. The spectrum resembles Gaussian distribution near the wavelength of the intensity peak, while it has an additional component of a broader foot. The measured broadening near the wavelength of the intensity peak corresponds to 0.6 eV hydrogen atom temperature. The spectrum exhibits a larger expansion in the blue wing which becomes smaller when the line of sight is tilted toward the driver region from the original observation axis parallel to the plasma grid. A surface collision simulation model predicts the possibility of hydrogen reflection at the plasma grid surface to form a broad Balmer-α light emission spectrum

  3. Doppler shift measurement of Balmer-alpha line spectrum emission from a plasma in a negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wada, M., E-mail: mwada@mail.doshisha.ac.jp; Doi, K. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 Japan (Japan); Kisaki, M.; Nakano, H.; Tsumori, K. [National Institute for Fusion Science, Toki, Gifu (Japan); Nishiura, M. [Graduate School of Frontier Sciences, The Universtiy of Tokyo, Chiba 277-8561 (Japan)

    2015-04-08

    Balmer-α light emission from the extraction region of the LHD one-third ion source has shown a characteristic Doppler broadening in the wavelength spectrum detected by a high resolution spectrometer. The spectrum resembles Gaussian distribution near the wavelength of the intensity peak, while it has an additional component of a broader foot. The measured broadening near the wavelength of the intensity peak corresponds to 0.6 eV hydrogen atom temperature. The spectrum exhibits a larger expansion in the blue wing which becomes smaller when the line of sight is tilted toward the driver region from the original observation axis parallel to the plasma grid. A surface collision simulation model predicts the possibility of hydrogen reflection at the plasma grid surface to form a broad Balmer-α light emission spectrum.

  4. Correlation between Balmer α emission and hydrogen flux through a superpermeable niobium membrane in a low-pressure multicusp plasma source

    International Nuclear Information System (INIS)

    Bruneteau, A.M.; Notkin, M.E.; Livshits, A.I.; Bacal, M.

    2002-01-01

    The purpose of this paper is to correlate hydrogen or deuterium flux through super permeable membranes with incident hydrogen or deuterium atom flux from the plasma. To this aim a hydrogen or deuterium plasma is created in a hybrid multicusp plasma source. We investigate Balmer α emission from the multicusp plasma and the output pressure behind a superpermeable niobium membrane immersed in the plasma.The output pressure is proportional to the flux of atoms and ions arriving on the membrane. We find that both output pressure and excited atoms emission satisfy plasma parameters relations. It is thus verified that plasma-driven superpermeation of hydrogen is due essentially to neutral atoms from the plasma incident to the membrane

  5. COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. II. BALMER EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Morlino, G.; Bandiera, R.; Blasi, P.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2012-12-01

    Strong shocks propagating into a partially ionized medium are often associated with optical Balmer lines. This emission is due to impact excitation of neutral hydrogen by hot protons and electrons in the shocked gas. The structure of such Balmer-dominated shocks has been computed in a previous paper, where the distribution function of neutral particles was derived from the appropriate Boltzmann equation including coupling with ions and electrons through charge exchange and ionization. This calculation showed how the presence of neutrals can significantly modify the shock structure through the formation of a neutral-induced precursor ahead of the shock. Here we follow up on our previous work and investigate the properties of the resulting Balmer emission, with the aim of using the observed radiation as a diagnostic tool for shock parameters. Our main focus is on supernova remnant shocks, and we find that, for typical parameters, the H{alpha} emission typically has a three-component spectral profile, where (1) a narrow component originates from upstream cold hydrogen atoms, (2) a broad component comes from hydrogen atoms that have undergone charge exchange with shocked protons downstream of the shock, and (3) an intermediate component is due to hydrogen atoms that have undergone charge exchange with warm protons in the neutral-induced precursor. The relative importance of these three components depends on the shock velocity, on the original degree of ionization, and on the electron-ion temperature equilibration level. The intermediate component, which is the main signature of the presence of a neutral-induced precursor, becomes negligible for shock velocities {approx}< 1500 km s{sup -1}. The width of the intermediate line reflects the temperature in the precursor, while the width of the narrow one is left unaltered by the precursor. In addition, we show that the profiles of both the intermediate and broad components generally depart from a thermal distribution, as a

  6. Structure of the Balmer jump. The isolated hydrogen atom

    Science.gov (United States)

    Calvo, F.; Belluzzi, L.; Steiner, O.

    2018-06-01

    Context. The spectrum of the hydrogen atom was explained by Bohr more than one century ago. We revisit here some of the aspects of the underlying quantum structure, with a modern formalism, focusing on the limit of the Balmer series. Aims: We investigate the behaviour of the absorption coefficient of the isolated hydrogen atom in the neighbourhood of the Balmer limit. Methods: We analytically computed the total cross-section arising from bound-bound and bound-free transitions in the isolated hydrogen atom at the Balmer limit, and established a simplified semi-analytical model for the surroundings of that limit. We worked within the framework of the formalism of Landi Degl'Innocenti & Landolfi (2004, Astrophys. Space Sci. Lib., 307), which permits an almost straight-forward generalization of our results to other atoms and molecules, and which is perfectly suitable for including polarization phenomena in the problem. Results: We analytically show that there is no discontinuity at the Balmer limit, even though the concept of a "Balmer jump" is still meaningful. Furthermore, we give a possible definition of the location of the Balmer jump, and we check that this location is dependent on the broadening mechanisms. At the Balmer limit, we compute the cross-section in a fully analytical way. Conclusions: The Balmer jump is produced by a rapid drop of the total Balmer cross-section, yet this variation is smooth and continuous when both bound-bound and bound-free processes are taken into account, and its shape and location is dependent on the broadening mechanisms.

  7. Hydrogenic fast-ion diagnostic using Balmer-alpha light

    International Nuclear Information System (INIS)

    Heidbrink, W W; Burrell, K H; Luo, Y; Pablant, N A; Ruskov, E

    2004-01-01

    Hydrogenic fast-ion populations are common in toroidal magnetic fusion devices, especially in devices with neutral beam injection. As the fast ions orbit around the device and pass through a neutral beam, some fast ions neutralize and emit Balmer-alpha light. The intensity of this emission is weak compared with the signals from the injected neutrals, the warm (halo) neutrals and the cold edge neutrals, but, for a favourable viewing geometry, the emission is Doppler shifted away from these bright interfering signals. Signals from fast ions are detected in the DIII-D tokamak. When the electron density exceeds ∼7 x 10 19 m -3 , visible bremsstrahlung obscures the fast-ion signal. The intrinsic spatial resolution of the diagnostic is ∼5 cm for 40 keV amu -1 fast ions. The technique is well suited for diagnosis of fast-ion populations in devices with fast-ion energies (∼30 keV amu -1 ), minor radii (∼0.6 m) and plasma densities (∼ 20 m -3 ) that are similar to those of DIII-D

  8. Hydrogen Balmer Line Broadening in Solar and Stellar Flares

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, Adam F. [Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, 2000 Colorado Avenue, Boulder, CO 80305 (United States); Allred, Joel C. [NASA/Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Uitenbroek, Han [National Solar Observatory, University of Colorado Boulder, 3665 Discovery Drive, Boulder, CO 80303 (United States); Tremblay, Pier-Emmanuel [Department of Physics, University of Warwick, Coventry CV47AL (United Kingdom); Brown, Stephen [School of Physics and Astronomy, Kelvin Building, University of Glasgow, G12 8QQ (United Kingdom); Carlsson, Mats [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Osten, Rachel A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Wisniewski, John P. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States); Hawley, Suzanne L., E-mail: Adam.Kowalski@lasp.colorado.edu [University of Washington Department of Astronomy, 3910 15th Avenue NE, Seattle, WA 98195 (United States)

    2017-03-10

    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from flare heating in the chromosphere. To resolve this issue, we have incorporated the unified theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative-transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt profiles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high nonthermal electron beam fluxes with the new broadening prescription and find that the Balmer lines are overbroadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a “multithread” model improves the agreement with the observations. We revisit the three-component phenomenological flare model of the YZ CMi Megaflare using recent and new RHD models. The evolution of the broadening, line flux ratios, and continuum flux ratios are well-reproduced by a multithread model with high-flux nonthermal electron beam heating, an extended decay phase model, and a “hot spot” atmosphere heated by an ultrarelativistic electron beam with reasonable filling factors: ∼0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modeling motivates future work to understand the origin of the extended gradual phase emission.

  9. Hydrogen Balmer Line Broadening in Solar and Stellar Flares

    International Nuclear Information System (INIS)

    Kowalski, Adam F.; Allred, Joel C.; Uitenbroek, Han; Tremblay, Pier-Emmanuel; Brown, Stephen; Carlsson, Mats; Osten, Rachel A.; Wisniewski, John P.; Hawley, Suzanne L.

    2017-01-01

    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from flare heating in the chromosphere. To resolve this issue, we have incorporated the unified theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative-transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt profiles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high nonthermal electron beam fluxes with the new broadening prescription and find that the Balmer lines are overbroadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a “multithread” model improves the agreement with the observations. We revisit the three-component phenomenological flare model of the YZ CMi Megaflare using recent and new RHD models. The evolution of the broadening, line flux ratios, and continuum flux ratios are well-reproduced by a multithread model with high-flux nonthermal electron beam heating, an extended decay phase model, and a “hot spot” atmosphere heated by an ultrarelativistic electron beam with reasonable filling factors: ∼0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modeling motivates future work to understand the origin of the extended gradual phase emission.

  10. Measurement of the deuterium Balmer series line emission on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C. R.; Xu, Z.; Jin, Z.; Zhang, P. F. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230031 (China); Huang, J., E-mail: juan.huang@ipp.ac.cn; Gao, W.; Gao, W.; Chang, J. F.; Xu, J. C.; Duan, Y. M.; Chen, Y. J.; Zhang, L.; Wu, Z. W.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Hou, Y. M. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-11-15

    Volume recombination plays an important role towards plasma detachment for magnetically confined fusion devices. High quantum number states of the Balmer series of deuterium are used to study recombination. On EAST (Experimental Advanced Superconducting Tokamak), two visible spectroscopic measurements are applied for the upper/lower divertor with 13 channels, respectively. Both systems are coupled with Princeton Instruments ProEM EMCCD 1024B camera: one is equipped on an Acton SP2750 spectrometer, which has a high spectral resolution ∼0.0049 nm with 2400 gr/mm grating to measure the D{sub α}(H{sub α}) spectral line and with 1200 gr/mm grating to measure deuterium molecular Fulcher band emissions and another is equipped on IsoPlane SCT320 using 600 gr/mm to measure high-n Balmer series emission lines, allowing us to study volume recombination on EAST and to obtain the related line averaged plasma parameters (T{sub e}, n{sub e}) during EAST detached phases. This paper will present the details of the measurements and the characteristics of deuterium Balmer series line emissions during density ramp-up L-mode USN plasma on EAST.

  11. Solar cycle variations of geocoronal balmer α emission

    International Nuclear Information System (INIS)

    Nossal, S.; Reynolds, R.J.; Roesler, F.L.; Scherb, F.

    1993-01-01

    Observations of the geocoronal Balmer in nightglow have been made from Wisconsin for more than a solar cycle with an internally consistent intensity reference to standard astronomical nebulae. These measurements were made with a double etalon, pressure-scanned, 15-cm aperture Fabry-Perot interferometer. The resulting long time data provides an opportunity to examine solar cycle influence on the mid-latitude exosphere and to address accompanying questions concerning the degree to which the exosphere is locally static or changing. The exospheric Balmer α absolute intensity measurements reported here show no statistically significant variations throughout the solar cycle when the variation with viewing geometry is removed by normalizing the data to reference exospheric model predictions by Anderson et al. However, the relative intensity dependence on solar depression angle does show a solar cycle variation. This variation suggests a possible related variation in the exospheric hydrogen density profile, although other interpretations are also possible. The results suggest that additional well-calibrated data taken over a longer time span could probe low-amplitude variations over the solar cycle and test predictions of a slow monotonic increase in exospheric hydrogen arising from greenhouse gases. 21 refs., 9 figs., 2 tabs

  12. Hydrogen Balmer alpha intensity distributions and line profiles from multiple scattering theory using realistic geocoronal models

    Science.gov (United States)

    Anderson, D. E., Jr.; Meier, R. R.; Hodges, R. R., Jr.; Tinsley, B. A.

    1987-01-01

    The H Balmer alpha nightglow is investigated by using Monte Carlo models of asymmetric geocoronal atomic hydrogen distributions as input to a radiative transfer model of solar Lyman-beta radiation in the thermosphere and atmosphere. It is shown that it is essential to include multiple scattering of Lyman-beta radiation in the interpretation of Balmer alpha airglow data. Observations of diurnal variation in the Balmer alpha airglow showing slightly greater intensities in the morning relative to evening are consistent with theory. No evidence is found for anything other than a single sinusoidal diurnal variation of exobase density. Dramatic changes in effective temperature derived from the observed Balmer alpha line profiles are expected on the basis of changing illumination conditions in the thermosphere and exosphere as different regions of the sky are scanned.

  13. CCD observations of the spatial structure of the hydrogen Balmer-alpha (Hα) diffuse galactic background

    International Nuclear Information System (INIS)

    Brinkmann, J.V.

    1987-01-01

    Images of hydrogen Balmer alpha emission were obtained in the galactic plane at the Orion arm rest velocity at longitudes of 66, 96, and 114 0 and at the Perseus arm velocity at 114 0 . These directions were chosen because of their lack of birth nebular emission and their high [Sll]6731/Hα ratio, a characteristic of the faint galactic emission-line background. The narrow band (0.26A) images were obtained during June and August 1985, and June 1986, with a newly-constructed RCA SID501DX CCD camera used with the existing 15-cm Fabry-Perot spectrometer at the Physical Sciences Laboratory of the University of Wisconsin, Madison. The field of view was 0. 0 75, with each binned pixel covering about two arc minutes. All images show a significant variation in detected Hα emission at the third-of-half-degree scale. The emission intensity varies by a factor of two over each field of view. Comparison of Orion arm and Perseus arm results indicates extinction is the most-likely cause of the observed spatial structure but star counts taken from the blue plate of Palomar Sky Survey show little spatial correlation with the α emission. This dilemma may be resolved by further investigations using IRAS images, which were not available in time for inclusion in this thesis

  14. Molecular enhancement of Balmer emissions following foil-induced dissociation of fast H2+ and H3+ ions

    International Nuclear Information System (INIS)

    Kobayashi, H.; Oda, N.

    1984-01-01

    Relative emission yields of Balmer lines as functions of the dwell time (t/sub D/ = 0.97--54.1 fs) in thin carbon foils (2--68 μg/cm 2 ) have been measured with (0.2--0.8)-MeV/amu H + , H 2 + , and H 3 + incident on thin carbon foils. Large molecular effects for emission yields of Balmer lines have been observed for H 2 + and H 3 + , where the molecular effect for H 3 + is larger than that for H 2 + . The molecular effects for H 2 + and H 3 + depend on the principal quantum number (n = 3--6), but this n dependence disappears at the largest t/sub D/ ( = 54.1 fs). The molecular effects rapidly decrease with increasing t/sub D/ in the small-t/sub D/ ( or approx. =2 fs) region. The magnitudes of the molecular effects at the largest t/sub D/ ( = 54.1 fs) are in good agreement with those by Andresen et al. [Phys. Scr. 19, 335 (1979)]. Relative populations of n-state hydrogens in the large-t/sub D/ (> or approx. =2 fs) region have been derived from the relative yields of Balmer lines as functions of n and t/sub D/. The molecular enhancement for relative populations of n-state hydrogens for H 2 + depends on n and t/sub D/, and decreases with increasing t/sub D/ and increases with increasing n

  15. Discovery of Variable Hydrogen Balmer Absorption Lines with Inverse Decrement in PG 1411+442

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xi-Heng; Pan, Xiang; Zhang, Shao-Hua; Sun, Lu-Ming; Ji, Tuo; Liu, Bo; Zhou, Hong-Yan [Polar Research Institute of China, Jinqiao Road 451, Shanghai 200136 (China); Wang, Jian-Guo [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Yang, Chen-Wei; Jiang, Ning, E-mail: zhouhongyan@pric.org.cn, E-mail: shixiheng@pric.org.cn [Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China)

    2017-07-01

    We present new optical spectra of the well-known broad absorption line (BAL) quasar PG 1411+442, using the DBSP spectrograph at the Palomar 200 inch telescope in 2014 and 2017 and the YFOSC spectrograph at the Lijiang 2.4 m telescope in 2015. A blueshifted narrow absorption line system is clearly revealed in 2014 and 2015 consisting of hydrogen Balmer series and metastable He i lines. The velocity of these lines is similar to the centroid velocity of the UV BALs, suggesting that both originate from the outflow. The Balmer lines vary significantly between the two observations and vanished in 2017. They were also absent in the archived spectra obtained before 2001. The variation is thought to be driven by photoionization change. Besides, the absorption lines show inversed Balmer decrement, i.e., the apparent optical depths of higher-order Balmer absorption lines are larger than those of lower-order lines, which is inconsistent with the oscillator strengths of the transitions. We suggest that such anomalous line ratios can be naturally explained by the thermal structure of a background accretion disk, which allows the obscured part of the disk to contribute differently to the continuum flux at different wavelengths. High-resolution spectroscopic and photometric monitoring would be very useful to probe the structure of the accretion disk as well as the geometry and physical conditions of the outflow.

  16. New value for the Rydberg constant by precision measurement of the hydrogen Balmer-β transition

    International Nuclear Information System (INIS)

    Zhao, P.

    1986-01-01

    The Rydberg constant R is determined to a very high accuracy of 3 parts in 10 10 by a direct comparison of the four hydrogen and deuterium Balmer-β transitions with a standard laser from the National Bureau of Standards. This experiment is now the most precise measurement for R and approaches the limits of accuracy for wavelength or frequency measurements in the visible region. The result is R = 109 737.315 73 (3) cm -1 with the definition of the meter: c = 299 792 458 m/sec. The experiment also yields the following results: the fine-structure splittings 4P/sub 1/2/ ↔ 4P/sub 3/2 in H: 1370.9 (3) MHz and in D: 1371.8(3) MHZ. The isotope shifts between H and D in the transitions 2S/sub 1/2/ ↔ 4P/sub 1/2/: 167 752.4(3) MHz and 2S/sub 1/2/ ↔ 4P/sub 3/2/ : 167 753.3 (3) MHz. The experiment utilizes atomic beam laser spectroscopy. A beam of atomic hydrogen (or deuterium) is excited by electron bombardment to the metastable 2S/sub 1/2/ state and is detected by a secondary electron emission detector. A chopped cw dye laser beam crosses the atomic beam at an angle of 90 0 to eliminate Doppler broadening. The metastables are quenched by laser excitation to 4P/sub 1/2/ or 4P/sub 3/2/ states. The signal is monitored by a lock-in amplifier with the chopper as reference

  17. The influence of static fields on the dynamic Stark spectra of hydrogen Balmer lines

    International Nuclear Information System (INIS)

    Janssen, G.C.A.M.; Jayakumar, R.; Granneman, E.H.A.

    1981-01-01

    In plasmas atomic-line radiation is influenced by static and high frequency fields. A simple method of calculating the Stark profiles of the Balmer α and β lines for the case of one-dimensional fields is discussed. Using a Holtsmark field for the static component, the resulting profile of Balmer α shows a splitting of the satellites. (author)

  18. Massive unseen companion of X Persei - emission contamination in the Balmer lines

    Energy Technology Data Exchange (ETDEWEB)

    Penrod, G.D.; Vogt, S.S.

    1985-12-01

    X Per is the optical counterpart of the pulsating X-ray source 4U 0352 + 30. Although nearly all observations of this system are consistent with a relatively simple model consisting of a normal O93-B0e star with a neutron star companion in a distant orbit, Hutchings et al. (1974) reported large-amplitude radial velocity variations with a 580-day period in the high-order Balmer absorption lines, which, if interpreted as orbital motion, imply the existence of a massive (more than 30 solar mass) unseen compansion, probably a black hole. High-quality Reticon spectra of the high-order Balmer lines have been obtained which show that the radial velocity variations reported by Hutchings et al. are spurious and are caused by asymmetric and variable emission components hiding in the absorption profiles. This result eliminates the necessity for postulating a massive, unseen secondary or tertiary star. All observed aspects of X Per now seem consistent with the Be + neutron star binary scenario. A previously reported 22.4-hr periodicity in the X-ray flux is explained in terms of nonradial g-mode pulsations of the Be star, which modulate the star's wind, and, hence, the accretion rate onto the neutron star. 21 references.

  19. Massive unseen companion of X Persei - emission contamination in the Balmer lines

    International Nuclear Information System (INIS)

    Penrod, G.D.; Vogt, S.S.

    1985-01-01

    X Per is the optical counterpart of the pulsating X-ray source 4U 0352 + 30. Although nearly all observations of this system are consistent with a relatively simple model consisting of a normal O93-B0e star with a neutron star companion in a distant orbit, Hutchings et al. (1974) reported large-amplitude radial velocity variations with a 580-day period in the high-order Balmer absorption lines, which, if interpreted as orbital motion, imply the existence of a massive (more than 30 solar mass) unseen compansion, probably a black hole. High-quality Reticon spectra of the high-order Balmer lines have been obtained which show that the radial velocity variations reported by Hutchings et al. are spurious and are caused by asymmetric and variable emission components hiding in the absorption profiles. This result eliminates the necessity for postulating a massive, unseen secondary or tertiary star. All observed aspects of X Per now seem consistent with the Be + neutron star binary scenario. A previously reported 22.4-hr periodicity in the X-ray flux is explained in terms of nonradial g-mode pulsations of the Be star, which modulate the star's wind, and, hence, the accretion rate onto the neutron star. 21 references

  20. Hydrogen Balmer series measurements and determination of Rydberg's constant using two different spectrometers

    International Nuclear Information System (INIS)

    Amrani, D

    2014-01-01

    This paper investigates the use of two different methods, the optical and the computer-aided diffraction-grating spectrometer, to measure the wavelength of visible lines of Balmer series from the hydrogen atomic spectrum and estimate the value of Rydberg's constant. Analysis and interpretation of data showed that both methods, despite their difference in terms of the type of equipment used, displayed good performance in terms of precision of measurements of wavelengths of spectral lines. A comparison was carried out between the experimental value of Rydberg's constant obtained with both methods and the accepted value. The results of Rydberg's constant obtained with both the optical and computer-aided spectrometers were 1.099 28 × 10 −7  m −1  and 1.095 13 × 10 −7  m −1  with an error difference of 0.17% and 0.20% compared to the accepted value 1.097 373 × 10 −7  m −1 , respectively. (paper)

  1. Measuring the electron density in plasmas from the difference of Lorentzian part of the widths of two Balmer series hydrogen lines

    Energy Technology Data Exchange (ETDEWEB)

    Yubero, C. [Grupo de Física de Plasmas: Diagnosis, Modelos y Aplicaciones (FQM-136), Edificio A. Einstein (C-2), Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba (Spain); García, M.C., E-mail: fa1gamam@uco.es [Grupo de Física de Plasmas: Diagnosis, Modelos y Aplicaciones (FQM-136), Edificio A. Einstein (C-2), Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba (Spain); Dimitrijevic, M.S. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia); Sola, A.; Gamero, A. [Grupo de Física de Plasmas: Diagnosis, Modelos y Aplicaciones (FQM-136), Edificio A. Einstein (C-2), Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba (Spain)

    2015-05-01

    We present an alternative optical emission spectroscopy method to measure the plasma electron density from the difference of widths of two Balmer series hydrogen lines (H{sub α} and H{sub β}), especially convenient for non-thermal plasmas since with this method, there is no need to know either the gas temperature or the van der Waals contribution to the Lorentzian part of the line. In this paper it has been assumed that the part of full width at half maximum due to Stark broadening can be determined with the approximation of Lorentzian line shape. The method has been applied to the determination of the electron density in an argon microwave-induced plasma maintained at atmospheric pressure, and comparison with the results obtained using other diagnostic methods has been done. - Highlights: • An alternative method to measure the electron density in plasmas from two Balmer series hydrogen lines (H{sub α} and H{sub β}) is presented. • The method is very convenient for plasmas with electron densities of the order of 10{sup 14} cm{sup −3} and above, at low gas temperatures. • It has been applied to the determination of the electron density of an argon microwave plasma at atmospheric pressure. • Results from it are in good agreement with previous ones obtained using other diagnostic methods.

  2. Study of neutral hydrogen transport in LHD core plasmas based on high dynamic-range Balmer-α spectroscopy

    International Nuclear Information System (INIS)

    Fujii, K.; Goto, M.; Morita, S.

    2014-10-01

    The radial distributions of the neutral hydrogen atom density and pressure in the Large Helical Device (LHD) were studied. The atom density distribution was determined from a detailed analysis of the intensity-calibrated Balmer-α line profile while the pressure distribution was obtained with a simple one-dimensional analytical model. We determined for the first time the atom density at the center of a fusion-oriented plasma, which is approximately three orders smaller than that at the edge. On the contrary, the atom pressure changes only a factor of 10 from the edge to core regions. (author)

  3. On the Origin of the Flare Emission in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral Lines?

    Energy Technology Data Exchange (ETDEWEB)

    Kleint, Lucia; Krucker, Säm [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland); Heinzel, Petr [Astronomical Institute, The Czech Academy of Sciences, Fričova 298, 25165 Ondřejov (Czech Republic)

    2017-03-10

    Continuum (“white-light,” WL) emission dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the emission arises from real continuum emission or enhanced spectral lines, possibly turning into emission. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral line emission to IRIS ’ SJI 2832 emission by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral line emission can contribute up to 100% to the observed slitjaw images (SJI) emission, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the lines on the emission can be significant.

  4. On the Origin of the Flare Emission in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral Lines?

    International Nuclear Information System (INIS)

    Kleint, Lucia; Krucker, Säm; Heinzel, Petr

    2017-01-01

    Continuum (“white-light,” WL) emission dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the emission arises from real continuum emission or enhanced spectral lines, possibly turning into emission. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral line emission to IRIS ’ SJI 2832 emission by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral line emission can contribute up to 100% to the observed slitjaw images (SJI) emission, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the lines on the emission can be significant.

  5. Doppler spectroscopy of hydrogen Balmer lines in a hollow cathode glow discharge in ammonia and argon-ammonia mixture

    International Nuclear Information System (INIS)

    Sisovic, N. M.; Konjevic, N.

    2008-01-01

    The results of Doppler spectroscopy of hydrogen Balmer lines from a stainless steel (SS) and copper (Cu) hollow cathode (HC) glow discharge in ammonia and argon-ammonia mixture are reported. The experimental profiles in ammonia discharge are fitted well by superposing three Gaussian profiles. The half widths, in energy units, of narrow and medium Gaussians are in the ranges 0.3-0.4 eV and 3-4 eV, respectively, for both hollow cathodes what is expected on the basis of earlier electron beam→NH 3 experiments. The half widths of the largest Gaussian in ammonia are 46 and 55 eV for SS and Cu HC, respectively. In argon-ammonia discharge, three Gaussians are also required to fit experimental profiles. While half widths of narrow and medium Gaussians are similar to those in ammonia, the half widths of the largest Gaussians are 35 and 42 eV for SS and Cu HC, respectively. The half widths of the largest Gaussians in ammonia and in argon-ammonia mixture indicate the presence of excessive Doppler broadening.

  6. Geocoronal Balmer α line profile observations and forward-model analysis

    Science.gov (United States)

    Mierkiewicz, E. J.; Bishop, J.; Roesler, F. L.; Nossal, S. M.

    2006-05-01

    High spectral resolution geocoronal Balmer α line profile observations from Pine Bluff Observatory (PBO) are presented in the context of forward-model analysis. Because Balmer series column emissions depend significantly on multiple scattering, retrieval of hydrogen parameters of general aeronomic interest from these observations (e.g., the hydrogen column abundance) currently requires a forward modeling approach. This capability is provided by the resonance radiative transfer code LYAO_RT. We have recently developed a parametric data-model comparison search procedure employing an extensive grid of radiative transport model input parameters (defining a 6-dimensional parameter space) to map-out bounds for feasible forward model retrieved atomic hydrogen density distributions. We applied this technique to same-night (March, 2000) ground-based Balmer α data from PBO and geocoronal Lyman β measurements from the Espectrógrafo Ultravioleta extremo para la Radiación Difusa (EURD) instrument on the Spanish satellite MINISAT-1 (provided by J.F. Gómez and C. Morales of the Laboratorio de Astrofisica Espacial y Física Fundamental, INTA, Madrid, Spain) in order to investigate the modeling constraints imposed by two sets of independent geocoronal intensity measurements, both of which rely on astronomical calibration methods. In this poster we explore extending this analysis to the line profile information also contained in the March 2000 PBO Balmer α data set. In general, a decrease in the Doppler width of the Balmer α emission with shadow altitude is a persistent feature in every night of PBO observations in which a wide range of shadow altitudes are observed. Preliminary applications of the LYAO_RT code, which includes the ability to output Doppler line profiles for both the singly and multiply scattered contributions to the Balmer α emission line, displays good qualitative agreement with regard to geocoronal Doppler width trends observed from PBO. Model-data Balmer

  7. Atomic hydrogen determination in medium-pressure microwave discharge hydrogen plasmas via emission actinometry

    International Nuclear Information System (INIS)

    Geng Zicai; Xu Yong; Yang Xuefeng; Wang Weiguo; Zhu Aimin

    2005-01-01

    Atomic hydrogen plays an important role in the chemical vapour deposition of functional materials, plasma etching and new approaches to the chemical synthesis of hydrogen-containing compounds. This work reports experimental determinations of atomic hydrogen in microwave discharge hydrogen plasmas formed from the TM 01 microwave mode in an ASTeX-type reactor, via optical emission spectroscopy using Ar as an actinometer. The relative intensities of the H atom Balmer lines and Ar-750.4 nm emissions as functions of input power and gas pressure have been investigated. At an input microwave power density of 13.5 W cm -3 , the approximate hydrogen dissociation fractions calculated from electron-impact excitation and quenching cross sections in the literature, decreased from ∼0.08 to ∼0.03 as the gas pressure was increased from 5 to 25 Torr. The influences of the above cross sections, and the electron and gas temperatures of the plasmas on the determination of the hydrogen dissociation fraction data have been discussed

  8. Precision Measurement of the Energies and Line Shapes of Antiprotonic Lyman and Balmer Transitions From Hydrogen and Helium Isotopes

    CERN Multimedia

    2002-01-01

    % PS207 \\\\ \\\\ For the study of the antiproton-proton and antiproton-nuclear spin-spin and spin-orbital interaction at threshold a high resolution measurement is proposed of the line shapes and energy shifts of antiprotonic K$\\alpha$ and L$\\alpha$ transitions of hydrogen and helium isotopes. The intense LEAR beam, stopped in the cyclotron trap at low gas pressure, provides a unique~X-ray~source with sufficient brightness. Charge coupled devices with their excellent background rejection and energy resolution allow a precise determination of the strong shifts and widths of the 1s hyperfine states of protonium, in addition the detection of the $\\bar{p}$D K$\\alpha$ transition should be possible. A focussing crystal spectrometer with a resolution $\\Delta$E/E of about l0$ ^- ^{4} $, which is superior in the accuracy of the energy determination by two orders of magnitude as compared to the present detection methods, will be used to measure the energies of the L$\\alpha$ transitions. This permits a first direct measure...

  9. The Redshifted Hydrogen Balmer and Metastable He 1 Absorption Line System in Mini-FeLoBAL Quasar SDSS J112526.12+002901.3: A Parsec-scale Accretion Inflow?

    Science.gov (United States)

    Shi, Xi-Heng; Jiang, Peng; Wang, Hui-Yuan; Zhang, Shao-Hua; Ji, Tuo; Liu, Wen-Juan; Zhou, Hong-Yan

    2016-10-01

    The accretion of the interstellar medium onto central super-massive black holes is widely accepted as the source of the gigantic energy released by the active galactic nuclei. However, few pieces of observational evidence have been confirmed directly demonstrating the existence of the inflows. The absorption line system in the spectra of quasar SDSS J112526.12+002901.3 presents an interesting example in which the rarely detected hydrogen Balmer and metastable He I absorption lines are found redshifted to the quasar's rest frame along with the low-ionization metal absorption lines Mg II, Fe II, etc. The repeated SDSS spectroscopic observations suggest a transverse velocity smaller than the radial velocity. The motion of the absorbing medium is thus dominated by infall. The He I* lines present a powerful probe to the strength of ionizing flux, while the Balmer lines imply a dense environment. With the help of photoionization simulations, we find that the absorbing medium is exposed to the radiation with ionization parameter U ≈ 10-1.8, and the density is n({{H}})≈ {10}9 {{cm}}-3. Thus the absorbing medium is located ˜4 pc away from the central engine. According to the similarity in the distance and physical conditions between the absorbing medium and the torus, we strongly propose the absorption line system as a candidate for the accretion inflow, which originates in the inner surface of the torus.

  10. Formation of broad Balmer wings in symbiotic stars

    International Nuclear Information System (INIS)

    Chang, Seok-Jun; Heo, Jeong-Eun; Hong, Chae-Lin; Lee, Hee-Won

    2016-01-01

    Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. In addition to many prominent emission lines symbiotic stars exhibit Raman scattered O VI features at 6825 and 7088 Å. Another notable feature present in the spectra of many symbiotics is the broad wings around Balmer lines. Astrophysical mechanisms that can produce broad wings include Thomson scattering by free electrons and Raman scattering of Ly,β and higher series by neutral hydrogen. In this poster presentation we produce broad wings around Hα and H,β adopting a Monte Carlo techinique in order to make a quantitative comparison of these two mechanisms. Thomson wings are characterized by the exponential cutoff given by the termal width whereas the Raman wings are dependent on the column density and continuum shape in the far UV region. A brief discussion is provided. (paper)

  11. Zero emission distributed hydrogen production

    International Nuclear Information System (INIS)

    Maddaloni, J.; Rowe, A.; Bailey, R.; McDonald, J.D.

    2004-01-01

    The need for distributed production facilities has become a critical issue in developing a hydrogen infrastructure. Hydrogen generation using processes that make effective use of what would normally be considered waste streams or process inefficiencies can have more favorable economics than stand-alone technologies. Currently, natural gas is distributed to industrial and residential customers through a network of pipelines. High pressure main lines move gas to the vicinity of consumers where the pressure is reduced for local, low pressure distribution. Often, the practice is to use an isenthalpic expansion which results in a cooling of the gas stream. Some of the natural gas is burned to preheat the fuel so that the temperature after the expansion is near ambient. This results in the destruction of exergy in the high pressure gas stream and produces CO 2 in the process. If, instead, a turbo-expander is used to reduce the stream pressure, work can be recovered using a generator and hydrogen can be produced via electrolysis. This method of hydrogen production is free of green-house gas emissions, makes use of existing gas distribution facilities, and uses exergy that would otherwise be destroyed. Pressure reduction using the work producing process (turbo-expander) is accompanied by a large drop in temperature, on the average of 70 K. The local gas distributor requires the gas temperature to be raised again to near 8 o C to prevent damage to valve assemblies. The required heating power after expansion can be on the order of megawatts (site dependent.) Supplying the heat can be seen as a cost if energy is taken from the system to reheat the fuel; however, the low temperature stream may also be considered an asset if the cooling power can be used for a local process. This analysis is the second stage of a study to examine the technical and economic feasibility of using pressure let-down sites as hydrogen production facilities. This paper describes a proposed

  12. High resolution measurements and modeling of auroral hydrogen emission line profiles

    Directory of Open Access Journals (Sweden)

    B. S. Lanchester

    Full Text Available Measurements in the visible wavelength range at high spectral resolution (1.3 Å have been made at Longyearbyen, Svalbard (15.8 E,78.2 N during an interval of intense proton precipitation. The shape and Doppler shift of hydrogen Balmer beta line profiles have been compared with model line profiles, using as input ion energy spectra from almost coincident passes of the FAST and DMSP spacecraft. The comparison shows that the simulation contains the important physical processes that produce the profiles, and confirms that measured changes in the shape and peak wave-length of the hydrogen profiles are the result of changing energy input. This combination of high resolution measurements with modeling provides a method of estimating the incoming energy and changes in flux of precipitating protons over Svalbard, for given energy and pitch-angle distributions. Whereas for electron precipitation, information on the incident particles is derived from brightness and brightness ratios which require at least two spectral windows, for proton precipitation the Doppler profile of resulting hydrogen emission is directly related to the energy and energy flux of the incident energetic protons and can be used to gather information about the source region. As well as the expected Doppler shift to shorter wavelengths, the measured profiles have a significant red-shifted component, the result of upward flowing emitting hydrogen atoms.

    Key words. Ionosphere (auroral ionosphere; particle precipitation – Magnetospheric physics (auroral phenomena

  13. High resolution measurements and modeling of auroral hydrogen emission line profiles

    Directory of Open Access Journals (Sweden)

    B. S. Lanchester

    2003-07-01

    Full Text Available Measurements in the visible wavelength range at high spectral resolution (1.3 Å have been made at Longyearbyen, Svalbard (15.8 E,78.2 N during an interval of intense proton precipitation. The shape and Doppler shift of hydrogen Balmer beta line profiles have been compared with model line profiles, using as input ion energy spectra from almost coincident passes of the FAST and DMSP spacecraft. The comparison shows that the simulation contains the important physical processes that produce the profiles, and confirms that measured changes in the shape and peak wave-length of the hydrogen profiles are the result of changing energy input. This combination of high resolution measurements with modeling provides a method of estimating the incoming energy and changes in flux of precipitating protons over Svalbard, for given energy and pitch-angle distributions. Whereas for electron precipitation, information on the incident particles is derived from brightness and brightness ratios which require at least two spectral windows, for proton precipitation the Doppler profile of resulting hydrogen emission is directly related to the energy and energy flux of the incident energetic protons and can be used to gather information about the source region. As well as the expected Doppler shift to shorter wavelengths, the measured profiles have a significant red-shifted component, the result of upward flowing emitting hydrogen atoms.Key words. Ionosphere (auroral ionosphere; particle precipitation – Magnetospheric physics (auroral phenomena

  14. Suppression of Hydrogen Emission in an X-class White-light Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Procházka, Ondrej; Milligan, Ryan O.; Mathioudakis, Mihalis [Astrophysics Research Centre, Queen’s University Belfast, Northern Ireland (United Kingdom); Allred, Joel C. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kowalski, Adam F. [Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, 2000 Colorado Avenue, Boulder, CO 80305 (United States); Kotrč, Pavel, E-mail: oprochazka01@qub.ac.uk [Astronomical Institute, The Czech Academy of Sciences, 25165 Ondřejov (Czech Republic)

    2017-03-01

    We present unique NUV observations of a well-observed X-class flare from NOAA 12087 obtained at the Ondřejov Observatory. The flare shows a strong white-light continuum but no detectable emission in the higher Balmer and Lyman lines. Reuven Ramaty High-Energy Solar Spectroscopic Imager and Fermi observations indicate an extremely hard X-ray spectrum and γ -ray emission. We use the RADYN radiative hydrodynamic code to perform two types of simulations: one where an energy of 3 × 10{sup 11} erg cm{sup −2} s{sup −1} is deposited by an electron beam with a spectral index of ≈3, and a second where the same energy is applied directly to the photosphere. The combination of observations and simulations allows us to conclude that the white-light emission and the suppression or complete lack of hydrogen emission lines is best explained by a model where the dominant energy deposition layer is located in the lower layers of the solar atmosphere, rather than the chromosphere.

  15. Acoustic emission during hydrogen absorption and desorption in palladium

    International Nuclear Information System (INIS)

    Ramesh, R.; Mukhopadhyay, C.K.; Jayakumar, T.; Baldev Raj

    1996-01-01

    Acoustic emission technique has been used to study charging and discharging of hydrogen in palladium. During charging, breaking of oxide film due to surface activation and saturation of hydrogen absorption have been identified by acoustic emission. In the discharging cycle, the desorption of hydrogen from the specimen leads to high AE activity immediately after initiation of discharging, followed by gradual decrease in the acoustic activity, which reaches a minimum upon completion of the desorption. The potential of the acoustic emission technique for studying the kinetics of hydrogen absorption and desorption in metals has been shown. (author)

  16. Searching for the Expelled Hydrogen Envelope in Type I Supernovae via Late-Time H α Emission

    Energy Technology Data Exchange (ETDEWEB)

    Vinko, J.; Silverman, J. M.; Wheeler, J. C.; MacQueen, P.; Marion, G. H. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Pooley, D. [Department of Physics and Astronomy, Trinity University, One Trinity Place, San Antonio, TX 78212 (United States); Szalai, T. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, Szeged, 6720 (Hungary); Kelly, P. [Department of Astronomy, University of California at Berkeley, 501 Campbell Hall, Berkeley, CA 94720-3411 (United States); Sárneczky, K. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege ut 15-17, Budapest, 1121 (Hungary)

    2017-03-01

    We report the first results from our long-term observational survey aimed at discovering late-time interaction between the ejecta of hydrogen-poor Type I supernovae (SNe I) and the hydrogen-rich envelope expelled from the progenitor star several decades/centuries before explosion. The expelled envelope, moving with a velocity of ∼10–100 km s{sup −1}, is expected to be caught up by the fast-moving SN ejecta several years/decades after explosion, depending on the history of the mass-loss process acting in the progenitor star prior to explosion. The collision between the SN ejecta and the circumstellar envelope results in net emission in the Balmer lines, especially H α . We look for signs of late-time H α emission in older SNe Ia/Ibc/IIb with hydrogen-poor ejecta via narrowband imaging. Continuum-subtracted H α emission has been detected for 13 point sources: 9 SN Ibc, 1 SN IIb, and 3 SN Ia events. Thirty-eight SN sites were observed on at least two epochs, from which three objects (SN 1985F, SN 2005kl, and SN 2012fh) showed significant temporal variation in the strength of their H α emission in our Direct Imaging Auxiliary Functions Instrument (DIAFI) data. This suggests that the variable emission is probably not due to nearby H ii regions unassociated with the SN and hence is an important additional hint that ejecta–circumstellar medium interaction may take place in these systems. Moreover, we successfully detected the late-time H α emission from the Type Ib SN 2014C, which was recently discovered as a strongly interacting SN in various (radio, infrared, optical, and X-ray) bands.

  17. 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)

  18. Enhanced field emission from carbon nanotubes by hydrogen plasma treatment

    International Nuclear Information System (INIS)

    Zhi, C.Y.; Bai, X.D.; Wang, E.G.

    2002-01-01

    The field emission capability of the carbon nanotubes (CNTs) has been improved by hydrogen plasma treatment, and the enhanced emission mechanism has been studied systematically using Fourier-transform infrared spectroscopy, Raman, and transmission electron microscopy. The hydrogen concentration in the samples increases with increasing plasma treatment duration. A C δ- -H δ+ dipole layer may form on CNTs' surface and a high density of defects results from the plasma treatment, which is likely to make the external surface of CNTs more active to emit electrons after treatment. In addition, the sharp edge of CNTs' top, after removal of the catalyst particles, may increase the local electronic field more effectively. The present study suggests that hydrogen plasma treatment is a useful method for improving the field electron emission property of CNTs

  19. Investigation of low emission combustors using hydrogen lean direct injection

    Directory of Open Access Journals (Sweden)

    Robert ISAC

    2011-09-01

    Full Text Available One of the key technology challenges for the use of hydrogen in gas turbine engines is the performance of the combustion system, in particular the fuel injectors. Tests were conducted to measure the nitrogen oxide (NOx emissions and combustion performance at inlet conditions of 588 to 811 K, 0.4 to 1.4 MPa, and equivalence ratios up to 0.48. All the injectors were based on Lean Direct Injection (LDI technology with multiple injection points and quick mixing. One challenge to hydrogen-based premixing combustion systems is flashback since hydrogen has a reaction rate over 7 times that of Jet-A.

  20. DETECTION OF BROAD Hα EMISSION LINES IN THE LATE-TIME SPECTRA OF A HYDROGEN-POOR SUPERLUMINOUS SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Lin; Masci, F. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Quimby, R. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Ofek, E.; Gal-Yam, A.; Vreeswijk, P. M.; Leloudas, G.; Cia, A. de; Yaron, O. [Department of Particle Physics and Astrophysics, Faculty of Physics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Cao, Y.; Kulkarni, S. R. [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, P. E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Rebbapragada, Umaa D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Woźniak, P. R., E-mail: lyan@ipac.caltech.edu [Space and Remote Sensing, ISR-2, MS-B244 Los Alamos National Laboratory Los Alamos, NM 87545 (United States)

    2015-12-01

    iPTF13ehe is a hydrogen-poor superluminous supernova (SLSN) at z = 0.3434, with a slow-evolving light curve and spectral features similar to SN2007bi. It rises in 83–148 days to reach a peak bolometric luminosity of ∼1.3 × 10{sup 44} erg s{sup −1}, then decays slowly at 0.015 mag day{sup −1}. The measured ejecta velocity is ∼ 13,000 km s{sup −1}. The inferred explosion characteristics, such as the ejecta mass (70–220 M{sub ⊙}), and the total radiative and kinetic energy (E{sub rad} ∼ 10{sup 51} erg, E{sub kin} ∼ 2 × 10{sup 53} erg), are typical of slow-evolving H-poor SLSN events. However, the late-time spectrum taken at +251 days (rest, post-peak) reveals a Balmeremission feature with broad and narrow components, which has never been detected before among other H-poor SLSNe. The broad component has a velocity width of ∼4500 km s{sup −1} and a ∼300 km s{sup −1} blueward shift relative to the narrow component. We interpret this broad Hα emission with a luminosity of ∼2 × 10{sup 41} erg s{sup −1} as resulting from the interaction between the supernova ejecta and a discrete H-rich shell, located at a distance of ∼4 × 10{sup 16} cm from the explosion site. This interaction causes the rest-frame r-band LC to brighten at late times. The fact that the late-time spectra are not completely absorbed by the shock-ionized H-shell implies that its Thomson scattering optical depth is likely ≤1, thus setting upper limits on the shell mass ≤30 M{sub ⊙}. Of the existing models, a Pulsational Pair Instability supernova model can naturally explain the observed 30 M{sub ⊙} H-shell, ejected from a progenitor star with an initial mass of (95–150) M{sub ⊙} about 40 years ago. We estimate that at least ∼15% of all SLSNe-I may have late-time Balmer emission lines.

  1. Acoustic emission from hydrogen saturated Type 304L stainless steel

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1978-01-01

    Acoustic emission is attributed to energy release within a material body by localized plastic deformation or failure processes. The elastic stress waves may come from slip band formation, mechanical twinning, martensite transformation, or crack propagation. Each of these processes has slightly different acoustic characteristics allowing for easy identification. Acoustic emission was monitored during tensile tests of Type 304L austenitic stainless steel to explore the applicability of the technique to hydrogen-assisted fracture

  2. 40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

    Science.gov (United States)

    2010-07-01

    ... Halogen HAP Emissions or HAP Metals Emissions From Process Vents 3 Table 3 to Subpart FFFF of Part 63... to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP... following table that applies to your process vents that contain hydrogen halide and halogen HAP emissions or...

  3. Emission scenarios for a global hydrogen economy and the consequences for global air pollution

    NARCIS (Netherlands)

    van Ruijven, B.J.; Lamarque, J.F.; van Vuuren, D.P.; Kram, T.; Eerens, H.

    2011-01-01

    Hydrogen is named as possible energy carrier for future energy systems. However, the impact of large-scale hydrogen use on the atmosphere is uncertain. Application of hydrogen in clean fuel cells reduces emissions of air pollutants, but emissions from hydrogen production and leakages of molecular

  4. 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

  5. Integral Field Spectroscopy of Balmer-dominated Shocks in the Magellanic Cloud Supernova Remnant N103B

    Energy Technology Data Exchange (ETDEWEB)

    Ghavamian, Parviz [Department of Physics, Astronomy and Geosciences, Towson University, Towson, MD 21252 (United States); Seitenzahl, Ivo R.; Dopita, M. A. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Vogt, Frédéric P. A. [European Southern Observatory, Av. Alonso de Córdova 3107, 763 0355 Vitacura, Santiago (Chile); Terry, Jason P. [Department of Physics and Astronomy, University of Georgia (United States); Williams, Brian J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Winkler, P. Frank, E-mail: pghavamian@towson.edu [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

    2017-10-01

    We present results of integral field spectroscopy of Balmer-dominated shocks in the LMC supernova remnant (SNR) N103B, carried out using the Wide Field Integral Spectrograph (WiFeS ) on the 2.3 m telescope at the Siding Spring Observatory in Australia. Existing X-ray studies of N103B have indicated an SN Ia origin. Radiative shock emission from clumpy material surrounding the SNR may result from interaction of the forward shock with relic stellar wind material, possibly implicating a thermonuclear explosion in a single-degenerate binary system. The recently discovered Balmer-dominated shocks mark the impact of the forward shock with low density, partially neutral CSM gas, and form a partial shell encircling clumps of material exhibiting radiative shocks. The WiFeS spectra of N103B reveal broad H α emission having a width as high as 2350 km s{sup −1} along the northern rim, and both H α and H β broad profiles having widths around 1300 km s{sup −1} along the southern rim. Fits to the H α line profiles indicate that in addition to the usual broad and narrow emission components, a third component of intermediate width exists in these Balmer-dominated shocks, ranging from around 125 km s{sup −1} up to 225 km s{sup −1} in width. This is consistent with predictions of recent Balmer-dominated shock models, which predict that an intermediate-width component will be generated in a fast neutral precursor. We derive a Sedov age of approximately 685 ± 20 years for N103B from the Balmer-dominated spectra, consistent with the young age of 380–860 years estimated from light echo studies.

  6. Cross sections for Balmer-α excitation in heavy particle collisions

    International Nuclear Information System (INIS)

    Bae, Y.K.

    1982-01-01

    Doppler shifted and unshifted Balmer-α radiation has been observed in the absolute sense for energetic H + , H 2 + and H 3 + ions incident on molecular hydrogen by the method of decay inside the target within the energy range of 20 keV to 150 keV. Most of the measurements were based on single-collision conditions, but a simple thick-target experiment has been tried for the case of dissociative excitation of the target molecules by H atoms. The Balmer-α radiation emitted by hydrogen and deuterium beams has been used as a diagnostic method of neutral beam parameters. One important neutral beam parameter is the species mix between H + , H 2 + and H 3 + ion currents produced by the ion source and accelerator. This species mix can be resolved by analysis of the Balmer-α radiation if the beam is observed along an off normal axis with sufficient spectral resolution to separate the Doppler shifted radiation components from each other. An impediment to this approach to measuring the ion species is that some of the required cross sections have not been measured. This is the motivation for the presented experimental work. A home made monochromator gave enough optical throughput and spectral resolution for separation of the Doppler shifted lines from the unshifted lines. By selectively varying the target pressure and the distance of travel into the target prior to the observation region, excitation cross sections for three different angular momentum states (3s, 3p and 3d) have been determined. Combinations of a linear polarizer and a half-wave plate were used for polarization measurement

  7. Black Hole Mass Estimation in Type 1 AGN: Hβ vs. Mg II Lines and the Role of Balmer Continuum

    Energy Technology Data Exchange (ETDEWEB)

    Kovačević-Dojčinović, Jelena [Astronomical Observatory, Belgrade (Serbia); Marčeta-Mandić, Sladjana; Popović, Luka Č., E-mail: sladjana@aob.rs [Astronomical Observatory, Belgrade (Serbia); Department of Astronomy, Faculty of Mathematics, University of Belgrade, Belgrade (Serbia)

    2017-07-24

    Here we investigate the Hβ and Mg II spectral line parameters used for the black hole mass (M{sub BH}) estimation for a sample of Type 1 Active Galactic Nuclei (AGN) spectra selected from the Sloan Digital Sky Survey (SDSS) database. We have analyzed and compared the virialization of the Hβ and Mg II emission lines, and found that the Hβ line is more confident virial estimator than Mg II. We have investigated the influence of the Balmer continuum emission to the M{sub BH} estimation from the UV parameters, and found that the Balmer continuum emission can contribute to the overestimation of the M{sub BH} on average for ~5% (up to 10%).

  8. The Influence of Gas Composition in Dielectric Barrier Discharges on the Broadening of the Hydrogen Hα Transition

    International Nuclear Information System (INIS)

    Janus, H. W.

    2006-01-01

    The distribution of hydrogen atoms responsible for emission of the Balmer Hα line in the region of the dielectric barrier discharges in the helium and hydrogen as well as in the argon and hydrogen mixtures, in the direction perpendicular to the electrode surfaces, has bee determined by the optical emission spectroscopy accounting for the polarization of the emitted light. The procedure of fitting the measured line profiles accounting for the Stark effect has been used for determination of the distribution of the electric field in the discharge region

  9. NO{sub x} emissions from combustion of hydrogen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Roertveit, Geir Johan

    2002-07-01

    This work includes five different parts each of which has resulted in a paper that is accepted and submitted for publication. Additionally, a short introductory background section precedes these papers. A significant amount of experimental data is presented for the combustion of hydrogen which focus on emission of NO{sub x}. Different dilutes were added to the hydrogen to reduce the flame temperature and subsequently the NO{sub x} emissions. These experiments were performed in a counterflow burner where a flat steady flame layer facilitated accurate measurements. The experiments were compared with numerical calculations to assist the interpretation and discussion of the results. It was found that the experimental results compared well with numerical calculations of NO{sub x} at temperatures of up to 1900 K, while for higher temperatures an increasing discrepancy was found due to the influence of the sampling equipment. Nitrogen diluted methane was enriched by hydrogen from 0to 100 % to study the effect of NO{sub x} with the use of different fuel mixtures in the same counterflow burner. For a similar temperature of the NO{sub x} emitted from a H{sub 2} flame is only 25 % of that of a methane flame. Experiments compared to the pure methane flame showed that there is only a reduction of NO{sub x} when there is very high hydrogen content in the fuel mixture and for most mixtures an actual increase in NO{sub x} is observed. This is found partly due to a triggering of the NO{sub x} from the prompt mechanism. Natural gas and methane have both been substituted by up to 30 % H{sub 2} at constant load in various burners to reveal the effect of H{sub 2} enrichment on emissions. The burners include a swirl burner, a fibre burner, a porous burner and a catalytically supported porous burner. The thermal loads were varied from 2.6 to 21 kW, while excess air ratios were varied form 1 to 1.8. In general little effect of H{sub 2} is found by enriching the fuel. At temperatures of up

  10. Mechanism of negative hydrogen ion emission from heated saline hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Hiroyuki; Serizawa, Naoshi; Takeda, Makiko; Hasegawa, Seiji [Ehime Univ., Matsuyama (Japan). Faculty of Science

    1997-02-01

    To find a clue to the mechanism of negative hydrogen ion emission from a heated sample ({approx}10 mg) of powdery saline hydride (LiH or CaH{sub 2}) deposited on a molybdenum ribbon ({approx}0.1 cm{sup 2}), both the ionic and electronic emission currents were measured as a function of sample temperature ({approx}700 - 800 K), thereby yielding {approx}10{sup -15} - 10{sup -12} A of H{sup -} after mass analysis and {approx}10{sup -7} - 10{sup -5} A of thermal electron. Thermophysical analysis of these data indicates that the desorption energy (E{sup -}) of H{sup -} and work function ({phi}) of the emitting sample surface are 5.1 {+-} 0.3 and 3.1 {+-} 0.2 eV for LiH, respectively, while E{sup -} is 7.7 {+-} 0.3 eV and {phi} is 5.0 {+-} 0.2 eV for CaH{sub 2}. Thermochemical analysis based on our simple model on the emissions indicates that the values of E{sup -} - {phi} are 2.35 and 2.31 eV for LiH and CaH{sub 2}, respectively, which are in fair agreement with the respective values (2.1 {+-} 0.3 and 2.6 {+-} 0.3 eV) determined experimentally. This agreement indicates that the emission of H{sup -} is reasonably explained by our model from the viewpoint of reaction energy. (author)

  11. Galactic neutral hydrogen emission-absorption observations from Arecibo

    International Nuclear Information System (INIS)

    Dickey, J.M.; Salpeter, E.E.; Terzian, Y.

    1978-01-01

    We have observed the interstellar medium in the directions of 27 extragalactic sources at high and intermediate galactic latitudes (vertical-barb/sup ii/vertical-bar>5 0 ) at 21 cm wavelength with the upgraded Arecibo telescope (HPBW=3'.2, gainapprox.6 K Jy -1 ). The small beam greatly reduces the uncertainty in the derived on-source emission profile and increases confidence that it corresponds to the same material as the absorption spectrum. Each region has been observed for approximately 2 hours to tetect optical depths as low as 10 -2 in most cases. The data allow the derivation of optical depths, harmonic mean spin temperatures, and column densities for the neutral hydrogen as a function of velocity in the range -200 -1 (LSR) with resolution as fine as 0.25 km s -1 . Spin temperatures as high as 1000 K are evident with a significant fraction of the neutral hydrogen still hotter. The cooler material is distributed over all temperatures from 30 K to at least 800 K. At latitudes below vertical-barb/sup ii/vertical-bar 0 values for the harmonic mean temperature T/sub spin/ in the range 100 K to 300 K are most common.We have detected 66 separate absorption features, tentatively associated with neutral hydrogen clouds, with central temperatures ranging from 30 to 500 K. These features conform well to the relationship T/sub spin/=45(1-e/sup -tau/)/sup -0.5/ (K), over a broad range of values of the optical depth. The velocity distribution of these clouds shows a significant negative-velocity ''tail'' at high and intermediate latitudes. The mean square velocity of the clouds seems to depend on optical depth: v/sub rms/ is greater (approx.11 km s -1 ) for the optically thin clouds (tau -1 ). High-negative-velocity emission (v -1 ) has been detected in six directions; in two of these corresponding absorption features are evident, indicating cool neutral material

  12. NOx reduction and NO2 emission characteristics in rich-lean combustion of hydrogen

    OpenAIRE

    Shudo, Toshio; Omori, Kento; Hiyama, Osamu

    2008-01-01

    Hydrogen is a clean alternative to conventional hydrocarbon fuels, but it is very important to reduce the nitrogen oxides (NOx) emissions generated by hydrogen combustion. The rich-lean combustion or staged combustion is known to reduce NOx emissions from continuous combustion burners such as gas turbines and boilers, and NOx reduction effects have been demonstrated for hydrocarbon fuels. The authors applied rich-lean combustion to a hydrogen gas turbine and showed its NOx reduction effect in...

  13. Neutral Hydrogen and Its Emission Lines in the Solar Corona

    Science.gov (United States)

    Vial, Jean-Claude; Chane-Yook, Martine

    2016-12-01

    Since the Lyman-α rocket observations of Gabriel ( Solar Phys. 21, 392, 1971), it has been realized that the hydrogen (H) lines could be observed in the corona and that they offer an interesting diagnostic for the temperature, density, and radial velocity of the coronal plasma. Moreover, various space missions have been proposed to measure the coronal magnetic and velocity fields through polarimetry in H lines. A necessary condition for such measurements is to benefit from a sufficient signal-to-noise ratio. The aim of this article is to evaluate the emission in three representative lines of H for three different coronal structures. The computations have been performed with a full non-local thermodynamic-equilibrium (non-LTE) code and its simplified version without radiative transfer. Since all collisional and radiative quantities (including incident ionizing and exciting radiation) are taken into account, the ionization is treated exactly. Profiles are presented at two heights (1.05 and 1.9 solar radii, from Sun center) in the corona, and the integrated intensities are computed at heights up to five solar radii. We compare our results with previous computations and observations ( e.g. Lα from Ultraviolet Coronal Spectrometer) and find a rough (model-dependent) agreement. Since the Hα line is a possible candidate for ground-based polarimetry, we show that in order to detect its emission in various coronal structures, it is necessary to use a very narrow (less than 2 Å wide) bandpass filter.

  14. Source of the violet depression in carbon stars (a study of the Balmer decrement in carbon L.P.V.s)

    International Nuclear Information System (INIS)

    Orlati, M.A.

    1985-01-01

    In an effort to determine the nature of the agent(s) of the violet depression in N-type stars through the behavior of their Balmer decrement, slit spectrograms of two C, one CS, two S (all reported to have the violet depression) and one M type LPVs were repeatedly taken between May 1983 and November 1984. The observed phase related changes in the Balmer decrement exclude the possibility that the absorbers are circumstellar because the emission region in the best-observed star is seen to rise through the opacity source. The exact nature and number of kinds of absorbers remains to be determined

  15. Impact of H{sub 2} emissions of a global hydrogen economy on the stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Grooss, Jens-Uwe; Feck, Thomas; Vogel, Baerbel; Riese, Martin [Forschungszentrum Juelich (Germany)

    2010-07-01

    ''Green'' hydrogen is seen as a major element of the future energy supply to reduce greenhouse gas emissions substantially. However, due to the possible interactions of hydrogen (H{sub 2}) with other atmospheric constituents there is a need to analyse the implications of additional atmospheric H{sub 2} that could result from hydrogen leakage of a global hydrogen infrastructure. Emissions of molecular H{sub 2} can occur along the whole hydrogen process chain which increase the tropospheric H{sub 2} burden. The impact of these emissions is investigated. Figure 1 is a sketch that clarifies the path way and impact of hydrogen in the stratosphere. The air follows the Brewer-Dobson circulation in which air enters the stratosphere through the tropical tropopause, ascends then to the upper stratosphere and finally descends in polar latitudes within a typical transport time frame of 4 to 8 years. (orig.)

  16. An experimental study on performance and emission characteristics of a hydrogen fuelled spark ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Kahraman, Erol [Program of Energy Engineering, Izmir Institute of Technology, Urla, Izmir 35430 (Turkey); Cihangir Ozcanli, S.; Ozerdem, Baris [Department of Mechanical Engineering, Izmir Institute of Technology, Urla, Izmir 35430 (Turkey)

    2007-08-15

    In the present paper, the performance and emission characteristics of a conventional four cylinder spark ignition (SI) engine operated on hydrogen and gasoline are investigated experimentally. The compressed hydrogen at 20 MPa has been introduced to the engine adopted to operate on gaseous hydrogen by external mixing. Two regulators have been used to drop the pressure first to 300 kPa, then to atmospheric pressure. The variations of torque, power, brake thermal efficiency, brake mean effective pressure, exhaust gas temperature, and emissions of NO{sub x}, CO, CO{sub 2}, HC, and O{sub 2} versus engine speed are compared for a carbureted SI engine operating on gasoline and hydrogen. Energy analysis also has studied for comparison purpose. The test results have been demonstrated that power loss occurs at low speed hydrogen operation whereas high speed characteristics compete well with gasoline operation. Fast burning characteristics of hydrogen have permitted high speed engine operation. Less heat loss has occurred for hydrogen than gasoline. NO{sub x} emission of hydrogen fuelled engine is about 10 times lower than gasoline fuelled engine. Finally, both first and second law efficiencies have improved with hydrogen fuelled engine compared to gasoline engine. It has been proved that hydrogen is a very good candidate as an engine fuel. The obtained data are also very useful for operational changes needed to optimize the hydrogen fueled SI engine design. (author)

  17. Climate policy, emissions trading and hydrogen : Results of a Mannesmann Pilotentwicklung study and options for the hydrogen community

    International Nuclear Information System (INIS)

    Geres, R.

    2002-01-01

    The use of emissions trading for the introduction of hydrogen technologies into the market was studied under the Mannesmann Pilotentwicklung. It was argued that the integration of environmental effects becomes part of the business planning on the revenue side, provided a scenario with environmental benefits like the reduction of greenhouse gas emissions in the atmosphere. New possibilities and opportunities are available for hydrogen technologies. It enables the definition of more detailed projects within the hydrogen community, considering factors such as economic, strategic, technological and political aims. The projects involve both mobile and stationary applications, and cover regional activities as well as international cooperation. Public institutions or the private sector can undertake them. As a result of the ratification of the Kyoto Protocol, an emissions trading scheme is scheduled to begin in 2005 inside the European Union. 2 refs., 2 tabs., 2 figs

  18. Cross Sections for Balmer-Alpha Excitation in Heavy Particle Collisions.

    Science.gov (United States)

    Bae, Young Kun

    Doppler shifted and unshifted Balmer-alpha radiation has been observed in the absolute sense for energetic H('+), H(,2)('+) and H(,3)('+) ions incident on molecular hydrogen by the method of decay inside the target within the energy range of 20 keV to 150 keV. Most of the measurements were based on single-collision conditions, but a simple thick -target experiment has been tried for the case of dissociative excitation of the target molecules by H atoms. The Balmer-alpha radiation emitted by hydrogen and deuterium beams has been used as a diagnostic method of neutral beam parameters. One important neutral beam parameter is the species mix between H('+), H(,2)('+) and H(,3)('+) ion currents produced by the ion source and accelerator. This species mix can be resolved by analysis of the Balmer-alpha radiation if the beam is observed along an off normal axis with sufficient spectral resolution to separate the Doppler shifted radiation components from each other. An impediment to this approach to measuring the ion species is that some of the required cross sections have not been measured. This is the motivation for the presented experimental work. A home made monochromator gave enough optical throughput and spectral resolution for separation of the Doppler shifted lines from the unshifted lines. By selectively varying the target pressure and the distance of travel into the target prior to the observation region, excitation cross sections for three different angular momentum states (3s, 3p and 3d) have been determined. Combinations of a linear polarizer and a half-wave plate were used for polarization measurement. Separation of the individual Zeeman levels have been tried for the 3p state from the information obtained from the polarization. Theoretical estimates of the cascading corrections have been applied in the case of both thin and thick targets. The intensity development equations for thick targets also have been derived. Cross sections for 3s production show

  19. Computational combustion and emission analysis of hydrogen-diesel blends with experimental verification

    International Nuclear Information System (INIS)

    Masood, M.; Ishrat, M.M.; Reddy, A.S.

    2007-01-01

    The paper discusses the effect of blending hydrogen with diesel in different proportions on combustion and emissions. A comparative study was carried out to analyze the effect of direct injection of hydrogen into the combustion chamber with that of induction through the inlet manifold for dual fueling. Percentage of hydrogen substitution varied from 20% to 80%, simultaneously reducing the diesel percentages. CFD analysis of dual fuel combustion and emissions were carried out for both the said methods using the CFD software FLUENT, meshing the combustion chamber was carried out using GAMBIT. The standard combustion and emission models were used in the analysis. In the second part of the paper, the effect of angle of injection in both the methods of hydrogen admission, on performance, combustion and emissions were analyzed. The experimental results were compared with that of simulated values and a good agreement between them was noticed. (author)

  20. Hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, E.; Kawahara, N. [Okayama Univ., Okayama (Japan); Roy, M.M. [Rajshahi Univ. of Engineering and Technology, Rajshahi (Bangladesh)

    2009-07-01

    A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N{sub 2} dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution to the diesel fuel with zero smoke emissions. figs.

  1. Hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel

    International Nuclear Information System (INIS)

    Tomita, E.; Kawahara, N.; Roy, M.M.

    2009-01-01

    A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N 2 dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution to the diesel fuel with zero smoke emissions. figs.

  2. An experimental study on performance and emission characteristics of a hydrogen fuelled spark ignition engine

    OpenAIRE

    Kahraman, Erol; Özcanlı, Şevket Cihangir; Özerdem, Barış

    2007-01-01

    In the present paper, the performance and emission characteristics of a conventional four cylinder spark ignition (SI) engine operated on hydrogen and gasoline are investigated experimentally. The compressed hydrogen at 20 MPa has been introduced to the engine adopted to operate on gaseous hydrogen by external mixing. Two regulators have been used to drop the pressure first to 300 kPa, then to atmospheric pressure. The variations of torque, power, brake thermal efficiency, brake mean effectiv...

  3. Variable composition hydrogen/natural gas mixtures for increased engine efficiency and decreased emissions

    Energy Technology Data Exchange (ETDEWEB)

    Sierens, R.; Rosseel, E.

    2000-01-01

    It is well known that adding hydrogen to natural gas extends the lean limit of combustion and that in this way extremely low emission levels can be obtained: even the equivalent zero emission vehicle (EZEV) requirements can be reached. The emissions reduction is especially important at light engine loads. In this paper results are presented for a GM V8 engine. Natural gas, pure hydrogen and different blends of these two fuels have been tested. The fuel supply system used provides natural gas/hydrogen mixtures in variable proportion, regulated independently of the engine operating condition. The influence of the fuel composition on the engine operating characteristics and exhaust emissions has been examined, mainly but not exclusively for 10 and 20% hydrogen addition. At least 10% hydrogen addition is necessary for a significant improvement in efficiency. Due to the conflicting requirements for low hydrocarbons and low NO{sub x} determining the optimum hythane composition is not straight-forward. For hythane mixtures with a high hydrogen fraction, it is found that a hydrogen content of 80% or less guarantees safe engine operation (no backfire nor knock), whatever the air excess factor. It is shown that to obtain maximum engine efficiency for the whole load range while taking low exhaust emissions into account, the mixture composition should be varied with respect to engine load.

  4. The Role of Hydrogen Bonds Of The Azeotropic Hydrous Ethanol Fuel Composition To The Exhaust Emissions

    Science.gov (United States)

    Made Suarta, I.; Nyoman Gede Baliarta, I.; Sopan Rahtika, I. P. G.; Wijaya Sunu, Putu

    2018-01-01

    In this study observed the role of hydrogen bonding to the composition of exhaust emissions which is produced hydrous ethanol fuel (95.5% v). Testing is done by using single cylinder four stroke motor engine. The composition of exhaust gas emissions is tested using exhaust gas analyzer on lean and stoichiometry mixer. The exhaust emissions produced by anhydrous ethanol were also tested. The composition of emissions produced by that two fuels is compared. The results showed CO emissions levels produced by hydrous ethanol are slightly higher than anhydrous ethanol in stoichiometric mixtures. But the composition of CO hydrous ethanol emissions is lower in the lean mix. If lean the mixer the different in the composition of emissions is increasing. On hydrous ethanol emission CO2 content little bit lower on the stoichiometric mixer and higher on the lean mixture. Exhaust emissions of ethanol fuel also produce O2. O2 hydrous ethanol emissions is higher than anhydrous ethanol fuel.

  5. Emission ratio and isotopic signatures of molecular hydrogen emissions from tropical biomass burning

    Science.gov (United States)

    Haumann, F. A.; Batenburg, A. M.; Pieterse, G.; Gerbig, C.; Krol, M. C.; Röckmann, T.

    2013-09-01

    In this study, we identify a biomass-burning signal in molecular hydrogen (H2) over the Amazonian tropical rainforest. To quantify this signal, we measure the mixing ratios of H2 and several other species as well as the H2 isotopic composition in air samples that were collected in the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) aircraft campaign during the dry season. We derive a relative H2 emission ratio with respect to carbon monoxide (CO) of 0.31 ± 0.04 ppb ppb-1 and an isotopic source signature of -280 ± 41‰ in the air masses influenced by tropical biomass burning. In order to retrieve a clear source signal that is not influenced by the soil uptake of H2, we exclude samples from the atmospheric boundary layer. This procedure is supported by data from a global chemistry transport model. The ΔH2 / ΔCO emission ratio is significantly lower than some earlier estimates for the tropical rainforest. In addition, our results confirm the lower values of the previously conflicting estimates of the H2 isotopic source signature from biomass burning. These values for the emission ratio and isotopic source signatures of H2 from tropical biomass burning can be used in future bottom-up and top-down approaches aiming to constrain the strength of the biomass-burning source for H2. Hitherto, these two quantities relied only on combustion experiments or on statistical relations, since no direct signal had been obtained from in-situ observations.

  6. Decentralized production of hydrogen from hydrocarbons with reduced CO2 emission

    International Nuclear Information System (INIS)

    Nazim Muradov; Franklyn Smith; Cunping Huang; Ali T-Raissi

    2006-01-01

    Currently, most of the industrial hydrogen production is based on steam methane reforming process that releases significant amount of CO 2 into the atmosphere. CO 2 sequestration is one approach to solving the CO 2 emission problem for large centralized hydrogen plants, but it would be impractical for decentralized H 2 production units. The objective of this paper is to explore new routes to hydrogen production from natural gas without (or drastically reduced) CO 2 emissions. One approach analyzed in this paper is based on thermo-catalytic decomposition (TCD) of hydrocarbons (e.g., methane) to hydrogen gas and elemental carbon. The paper discusses some technological aspects of the TCD process development: (1) thermodynamic analysis of TCD using AspenPlus chemical process simulator, (2) heat input options to the endothermic process, (3) catalyst activity issues, etc. Production of hydrogen and carbon via TCD of methane was experimentally verified using carbon-based catalysts. (authors)

  7. [Study on the Emission Spectrum of Hydrogen Production with Microwave Discharge Plasma in Ethanol Solution].

    Science.gov (United States)

    Sun, Bing; Wang, Bo; Zhu, Xiao-mei; Yan, Zhi-yu; Liu, Yong-jun; Liu, Hui

    2016-03-01

    Hydrogen is regarded as a kind of clean energy with high caloricity and non-pollution, which has been studied by many experts and scholars home and abroad. Microwave discharge plasma shows light future in the area of hydrogen production from ethanol solution, providing a new way to produce hydrogen. In order to further improve the technology and analyze the mechanism of hydrogen production with microwave discharge in liquid, emission spectrum of hydrogen production by microwave discharge plasma in ethanol solution was being studied. In this paper, plasma was generated on the top of electrode by 2.45 GHz microwave, and the spectral characteristics of hydrogen production from ethanol by microwave discharge in liquid were being studied using emission spectrometer. The results showed that a large number of H, O, OH, CH, C2 and other active particles could be produced in the process of hydrogen production from ethanol by microwave discharge in liquid. The emission spectrum intensity of OH, H, O radicals generated from ethanol is far more than that generated from pure water. Bond of O-H split by more high-energy particles from water molecule was more difficult than that from ethanol molecule, so in the process of hydrogen production by microwave discharge plasma in ethanol solution; the main source of hydrogen was the dehydrogenation and restructuring of ethanol molecules instead of water decomposition. Under the definite external pressure and temperature, the emission spectrum intensity of OH, H, O radicals increased with the increase of microwave power markedly, but the emission spectrum intensity of CH, C2 active particles had the tendency to decrease with the increase of microwave power. It indicated that the number of high energy electrons and active particles high energy electron energy increased as the increase of microwave power, so more CH, C2 active particles were split more thoroughly.

  8. A rationale for large inertial fusion plants producing hydrogen for powering low emission vehicles

    International Nuclear Information System (INIS)

    Logan, B.G.

    1993-01-01

    Inertial Fusion Energy (IFE) has been identified in the 1991 National Energy Strategy, along with Magnetic Fusion Energy (MFE), as one of only three inexhaustible energy sources for long term energy supply (past 2025), the other alternatives being fission and solar energy. Fusion plants, using electrolysis, could also produce hydrogen to power low emission vehicles in a potentially huge future US market: > 500 GWe would be needed for example, to replace all foreign oil imports with equal-energy hydrogen, assuming 70%-efficient electrolysis. Any inexhaustible source of electricity, including IFE and MFE reactors, can thus provide a long term renewable source of hydrogen as well as solar, wind and biomass sources. Hydrogen production by both high temperature thermochemical cycles and by electrolysis has been studied for MFE, but avoiding trace tritium contamination of the hydrogen product would best be assured using electrolysis cells well separated from any fusion coolant loops. The motivations to consider IFE or MFE producing renewable hydrogen are: (1) reducing US dependence on foreign oil imports and the associated trade deficient; (2) a hydrogen-based transportation system could greatly mitigate future air pollution and greenhouse gases; (3) investments in hydrogen pipelines, storage, and distribution systems could be used for a variety of hydrogen sources; (4) a hydrogen pipeline system could access and buffer sufficiently large markets that temporary outages of large (>> 1 GWe size) fusion hydrogen units could be tolerated

  9. Concept for lowest emissions of a hydrogen internal combustion engine; Niedrigstemissionskonzept fuer einen wasserstoffbetriebenen Verbrennungsmotor

    Energy Technology Data Exchange (ETDEWEB)

    Fouquet, Marcel Christian Thomas

    2012-03-15

    This paper describes a concept with lowest emissions for a hydrogen internal combustion engine for passenger cars. With optimisation of the combustion concept the level of nitrogen oxide is below 90%, hydrocarbon and carbon monoxide below 99% of the SULEV target (CARB). This concept enables a potential in power density that is comparable to current supercharged combustion engines at lowest emission level without catalytic aftertreatment. Additionally with a catalytic aftertreatment system, the emission level of a current hydrogen combustion engine (mono-fuel) is lowered to a level, that this car can be labeled as air cleaning vehicle for hydrocarbons and carbon monoxide.

  10. Atomic hydrogen and diatomic titanium-monoxide molecular spectroscopy in laser-induced plasma

    Science.gov (United States)

    Parigger, Christian G.; Woods, Alexander C.

    2017-03-01

    This article gives a brief review of experimental studies of hydrogen Balmer series emission spectra. Ongoing research aims to evaluate early plasma evolution following optical breakdown in laboratory air. Of interest is as well laser ablation of metallic titanium and characterization of plasma evolution. Emission of titanium monoxide is discussed together with modeling of diatomic spectra to infer temperature. The behavior of titanium particles in plasma draws research interests ranging from the modeling of stellar atmospheres to the enhancement of thin film production via pulsed laser deposition.

  11. Trapping and re-emission of energetic hydrogen and helium ions in materials

    International Nuclear Information System (INIS)

    Yamaguchi, Sadae

    1981-01-01

    The experimental results on the trapping and re-emission of energetic hydrogen and helium ions in materials are explained. The trapping of deuterium and helium in graphite saturates at the concentration of 10 18 ions/cm 2 . The trapping rate of hydrogen depends on the kinds of target materials. In the case of the implantation in Mo over 3 x 10 16 H/cm 2 , hydrogen is hardly trapped. On the other hand, the trapping of hydrogen in Ti, Zr and Ta which form solid solution is easily made. The hydrogen in these metals can diffuse toward the inside of metals. The deuterium retained in 316 SS decreased with time. The trapping rate reached saturation more rapidly at higher implantation temperature. The effective diffusion constant for the explanation of the re-emission process is 1/100 as small as the ordinary value. The radiation damage due to helium irradiation affects on the trapping of deuterium in Mo. The temperature dependence of the trapping rate can be explained by the diffusion model based on the Sievert's law. The re-emission of helium was measured at various temperature. At low temperature, the re-emission was low at first, then the rate increased. At high temperature, the re-emission rate was high from the beginning. (Kato, T.)

  12. Removal of hydrogen fluoride from uranium plant emissions

    International Nuclear Information System (INIS)

    Ramani, M.P.S.

    1997-01-01

    Uranium production technology involves the use of hydrogen fluoride at various stages. It is used in the production of uranium tetrafluoride as well as for the production of fluorine for the conversion of tetrafluoride to hexafluoride in isotopic enrichment plants. The sources of HF pollution in the industry, besides accidental spillages and leakages, are the final off-gases from the UF 4 production process or from the hydrogen reduction of hexafluoride (where such process is adopted), venting of tanks and reactors containing HF, safety pressure rupture discs as well as dust collection and ventilation systems

  13. Measurement of effective solvus temperature of hydrogen in Zr - 2. 5 wt % Nb using acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, C.E.; Ambler, J.F.R.

    1978-01-01

    The effect of applied tensile stress on the solvus temperature of hydrogen in cold-worked Zr - 2.5 wt % Nb has been measured using acoustic emission. Hydrides are necessary for delayed hydrogen cracking and the lowest temperature at which hydride cracking cannot be detected by acoustic emission was taken as the solvus temperature. The results show that any effect of tensile stress on terminal solubility, Cs, is undetectable. Between about 2 and 100 ppM hydrogen, the results can be described by: C/sub s/ = 1.40 x 10/sup 5/ exp - (36100/RT) ppM. They also suggest that the equilibrium phase, delta-hydride, is responsible for delayed hydrogen cracking.

  14. Ion-induced emission of charged particles from solid hydrogen and deuterium

    International Nuclear Information System (INIS)

    Borgesen, P.; Schou, J.; Sorensen, H.

    1980-01-01

    Measurements have been made of the emission of both positive and negative particles from solid hydrogen and deuterium for normal incidence of H + , H + 2 , H + 3 , D 2 H + , D + 3 and He + ions up to 10 keV. For positive particles the emission coefficient increased with increasing energy of incidence to reach a value of 0.08 per atom for 10 keV H + onto hydrogen. Apparently the positive particles are sputtered ones. The negative particles emitted are predominantly electrons. The emission coefficient per incident atom as a function of the velocity of the incident particle agress fairly well with results published earlier for incidence of hydrogen and deuterium ions. However, systematic differences of up to 10% are now observed between the coefficients for the different types of ions. (orig.)

  15. Emission Spectra of Hydrogen-Seeded Helium Arcjets

    National Research Council Canada - National Science Library

    Welle, R

    2000-01-01

    .... This work reports on a recent set of experiments in which emission spectra of the plume of a helium arcjet were acquired and analyzed to obtain information on the internal energy modes of the arcjet...

  16. Cold excitation and determination of hydrogen sulfide by dielectric barrier discharge molecular emission spectrometry.

    Science.gov (United States)

    Wu, Zhongchen; Jiang, Jie; Li, Na

    2015-11-01

    A low-temperature microplasma generated in a dielectric barrier discharge (DBD) was used as a radiation source for the excitation of hydrogen sulfide and its determination by molecular emission spectrometry (MES). The excitation/emission chamber was enclosed to eliminate spectral interference from ambient air. The spectral emission lines of hydrogen sulfide were clearly discriminated from the background spectrum, and the emission line at 365.06 nm was selected for parameter optimization and quantitative analysis. The S(2-) ions in aqueous samples were reacted with acid to generate hydrogen sulfide and then determined. The experimental parameters affecting the determination of hydrogen sulfide and S(2-) were optimized. The limits of detection were 1.4 mg m(-3) for H2S and 11.2 mg L(-1) for S(2-). The repeatability of the method was satisfactory, as the RSD values were 2.3% for H2S and 1.8% for S(2-). The enclosed DBD-MES system was demonstrated to be a useful tool for the determination of hydrogen sulfide in gas samples and S(2-) in aqueous samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. An investigation of engine performance parameters and artificial intelligent emission prediction of hydrogen powered car

    International Nuclear Information System (INIS)

    Ho, Tien; Karri, Vishy; Lim, Daniel; Barret, Danny

    2008-01-01

    With the depletion of fossil fuel resources and the potential consequences of climate change due to fossil fuel use, much effort has been put into the search for alternative fuels for transportation. Although there are several potential alternative fuels, which have low impact on the environment, none of these fuels have the ability to be used as the sole 'fuel of the future'. One fuel which is likely to become a part of the over all solution to the transportation fuel dilemma is hydrogen. In this paper, The Toyota Corolla four cylinder, 1.8 l engine running on petrol is systematically converted to run on hydrogen. Several ancillary instruments for measuring various engine operating parameters and emissions are fitted to appraise the performance of the hydrogen car. The effect of hydrogen as a fuel compares with gasoline on engine operating parameters and effect of engine operating parameters on emission characteristics is discussed. Based on the experimental setup, a suite of neural network models were tested to accurately predict the effect of major engine operating conditions on the hydrogen car emissions. Predictions were found to be ±4% to the experimental values. This work provided better understanding of the effect of engine process parameters on emissions. (author)

  18. Hydrogen content in Zircaloy-IV by neutron emissions

    International Nuclear Information System (INIS)

    Granada, J.R.

    1991-01-01

    The feasibility of using thermal neutron transmission techniques to determine the initial hydrogen content in Zry-IV is discussed in this work. The usual conditions of very low H concentration (∼ 10-20 ppm in weight) in the alloy, require a high degree of accuracy in the relevant cross sections in order to obtain reliable values of that concentration from the measured transmission spectra. Total cross sections corresponding to the metallic alloy and to hydrogen in that matrix were evaluated using interaction models developed in this Laboratory, for neutrons covering the range from subthermal up to epithermal energies. The sensitivity of this method as a function of neutron energy is discussed, and an optimized and self consistent procedure for data analysis after a transmission experiment is proposed. (Author) [es

  19. Acoustic emission monitoring of activation behavior of LaNi5 hydrogen storage alloy

    Directory of Open Access Journals (Sweden)

    Igor Maria De Rosa, Alessandro Dell'Era, Mauro Pasquali, Carlo Santulli and Fabrizio Sarasini

    2011-01-01

    Full Text Available The acoustic emission technique is proposed for assessing the irreversible phenomena occurring during hydrogen absorption/desorption cycling in LaNi5. In particular, we have studied, through a parametric analysis of in situ detected signals, the correlation between acoustic emission (AE parameters and the processes occurring during the activation of an intermetallic compound. Decreases in the number and amplitude of AE signals suggest that pulverization due to hydrogen loading involves progressively smaller volumes of material as the number of cycles increases. This conclusion is confirmed by electron microscopy observations and particle size distribution measurements.

  20. Emission spectroscopy of hydrogen molecules in technical and divertor plasmas

    International Nuclear Information System (INIS)

    Fantz, U.

    2002-01-01

    The paper gives an overview of the diagnostics of hydrogen molecules in technical plasmas (MW and RF discharges) and in divertor plasmas of fusion experiments (ASDEX Upgrade / Tokamak at the Max-Planck-Institut fuer Plasmaphysik in Garching near Munich, Germany). The Fulcher transition in the visible spectral range was chosen for analysis since this is the most prominent band in the spectrum of molecular hydrogen. Examples for diagnostics of molecular densities will be given, and the problems arising in the interpretation of spectra will be discussed. In divertor plasmas the diagnostics of molecular.uxes will be introduced and the contribution of molecules to the plasma recombination will be discussed. Results for vibrational populations in the ground state and the correlation to the upper Fulcher state will be given, providing an electron temperature diagnostic. Finally, the in.uence of surfaces (high-grade steel and graphite) on vibrational populations and on re.ection coe.cients of atoms will be shown. Special attention is given on a comparison of the isotopes hydrogen and deuterium. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  1. Estimating changes in urban ozone concentrations due to life cycle emissions from hydrogen transportation systems

    Science.gov (United States)

    Wang, Guihua; Ogden, Joan M.; Chang, Daniel P. Y.

    Hydrogen has been proposed as a low polluting alternative transportation fuel that could help improve urban air quality. This paper examines the potential impact of introducing a hydrogen-based transportation system on urban ambient ozone concentrations. This paper considers two scenarios, where significant numbers of new hydrogen vehicles are added to a constant number of gasoline vehicles. In our scenarios hydrogen fuel cell vehicles (HFCVs) are introduced in Sacramento, California at market penetrations of 9% and 20%. From a life cycle analysis (LCA) perspective, considering all the emissions involved in producing, transporting, and using hydrogen, this research compares three hypothetical natural gas to hydrogen pathways: (1) on-site hydrogen production; (2) central hydrogen production with pipeline delivery; and (3) central hydrogen production with liquid hydrogen truck delivery. Using a regression model, this research shows that the daily maximum temperature correlates well with atmospheric ozone formation. However, increases in initial VOC and NO x concentrations do not necessarily increase the peak ozone concentration, and may even cause it to decrease. It is found that ozone formation is generally limited by NO x in the summer and is mostly limited by VOC in the fall in Sacramento. Of the three hydrogen pathways, the truck delivery pathway contributes the most to ozone precursor emissions. Ozone precursor emissions from the truck pathway at 9% market penetration can cause additional 3-h average VOC (or NO x) concentrations up to approximately 0.05% (or 1%) of current pollution levels, and at 20% market penetration up to approximately 0.1% (or 2%) of current pollution levels. However, all of the hydrogen pathways would result in very small (either negative or positive) changes in ozone air quality. In some cases they will result in worse ozone air quality (mostly in July, August, and September), and in some cases they will result in better ozone air quality

  2. Estimating changes in urban ozone concentrations due to life cycle emissions from hydrogen transportation systems

    International Nuclear Information System (INIS)

    Guihua Wang; Ogden, Joan M.; Chang, Daniel P.Y.

    2007-01-01

    Hydrogen has been proposed as a low polluting alternative transportation fuel that could help improve urban air quality. This paper examines the potential impact of introducing a hydrogen-based transportation system on urban ambient ozone concentrations. This paper considers two scenarios, where significant numbers of new hydrogen vehicles are added to a constant number of gasoline vehicles. In our scenarios hydrogen fuel cell vehicles (HFCVs) are introduced in Sacramento, California at market penetrations of 9% and 20%. From a life cycle analysis (LCA) perspective, considering all the emissions involved in producing, transporting, and using hydrogen, this research compares three hypothetical natural gas to hydrogen pathways: (1) on-site hydrogen production; (2) central hydrogen production with pipeline delivery; and (3) central hydrogen production with liquid hydrogen truck delivery. Using a regression model, this research shows that the daily maximum temperature correlates well with atmospheric ozone formation. However, increases in initial VOC and NO x concentrations do not necessarily increase the peak ozone concentration, and may even cause it to decrease. It is found that ozone formation is generally limited by NO x in the summer and is mostly limited by VOC in the fall in Sacramento. Of the three hydrogen pathways, the truck delivery pathway contributes the most to ozone precursor emissions. Ozone precursor emissions from the truck pathway at 9% market penetration can cause additional 3-h average VOC (or NO x ) concentrations up to approximately 0.05% (or 1%) of current pollution levels, and at 20% market penetration up to approximately 0.1% (or 2%) of current pollution levels. However, all of the hydrogen pathways would result in very small (either negative or positive) changes in ozone air quality. In some cases they will result in worse ozone air quality (mostly in July, August, and September), and in some cases they will result in better ozone air

  3. An intensity map of hydrogen 21-cm emission at redshift z approximately 0.8.

    Science.gov (United States)

    Chang, Tzu-Ching; Pen, Ue-Li; Bandura, Kevin; Peterson, Jeffrey B

    2010-07-22

    Observations of 21-cm radio emission by neutral hydrogen at redshifts z approximately 0.5 to approximately 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z approximately 1, where traditional optical cosmology becomes very difficult because of the infrared opacity of the atmosphere. Hitherto, 21-cm emission has been detected only to z = 0.24. More distant galaxies generally are too faint for individual detections but it is possible to measure the aggregate emission from many unresolved galaxies in the 'cosmic web'. Here we report a three-dimensional 21-cm intensity field at z = 0.53 to 1.12. We then co-add neutral-hydrogen (H i) emission from the volumes surrounding about 10,000 galaxies (from the DEEP2 optical galaxy redshift survey). We detect the aggregate 21-cm glow at a significance of approximately 4sigma.

  4. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride III Appendix III to Part 266 Protection of Environment... to Part 266—Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride Terrain...

  5. Secondary Electron Emission from Solid Hydrogen and Deuterium Resulting from Incidence of keV Electrons and Hydrogen Ions

    DEFF Research Database (Denmark)

    Sørensen, H.

    1977-01-01

    are small, in contrast to what is expected for insulating materials. One explanation is that the secondary electrons lose energy inside the target material by exciting vibrational and rotational states of the molecules, so that the number of electrons that may escape as secondary electrons is rather small....... The losses to molecular states will be largest for hydrogen, so that the SEE coefficients are smallest for solid hydrogen, as was observed. For the incidence of ions, the values of δ for the different molecular ions agree when the number of secondary electrons per incident atom is plotted versus the velocity...... or the stopping power of the incident particles. Measurements were also made for oblique incidence of H+ ions on solid deuterium for angles of incidence up to 75°. A correction could be made for the emission of secondary ions by also measuring the current calorimetrically. At largest energies, the angular...

  6. Ammonia, nitrous oxide and hydrogen cyanide emissions from five passenger vehicles

    International Nuclear Information System (INIS)

    Karlsson, Hua Lu

    2004-01-01

    In this paper, three unregulated components, ammonia, nitrous oxide and hydrogen cyanide, emitted from five passenger vehicles are investigated. With focus upon emission factors from existing production technology, vehicles produced between 1989 and 1998 with considerable mileage (7000 to 280,000) are chosen. Among the five vehicles, four were sold in the European market, whereas one was sold in the US market. The vehicles are tested on a chassis dynamometer. An EU2000 Driving Cycle (NEDC) and a US Urban Driving Cycle (UDC) of the Federal Test Procedure 75 (FTP-75) are used in the study. The regulated emissions are measured using a Horiba Mexa series. Unregulated emissions, ammonia (NH 3 ), nitrous oxide (N 2 O) and hydrogen cyanide (HCN) are analysed by mass spectrometer, gas chromatography and CNT-NA, TIM315-74W method, respectively. Both the unregulated emissions and the regulated emissions show driving cycle dependency; and they are also improved with newer vehicle and emission control technology. However, a gasoline direct injection vehicle (relatively new technology in this study) has rather high regulated emissions, whereas the NH 3 , N 2 O and HCN emissions are low

  7. Ammonia, nitrous oxide and hydrogen cyanide emissions from five passenger vehicles.

    Science.gov (United States)

    Karlsson, Hua Lu

    2004-12-01

    In this paper, three unregulated components, ammonia, nitrous oxide and hydrogen cyanide, emitted from five passenger vehicles are investigated. With focus upon emission factors from existing production technology, vehicles produced between 1989 and 1998 with considerable mileage (7000 to 280,000) are chosen. Among the five vehicles, four were sold in the European market, whereas one was sold in the US market. The vehicles are tested on a chassis dynamometer. An EU2000 Driving Cycle (NEDC) and a US Urban Driving Cycle (UDC) of the Federal Test Procedure 75 (FTP-75) are used in the study. The regulated emissions are measured using a Horiba Mexa series. Unregulated emissions, ammonia (NH(3)), nitrous oxide (N(2)O) and hydrogen cyanide (HCN) are analysed by mass spectrometer, gas chromatography and CNT-NA, TIM315-74W method, respectively. Both the unregulated emissions and the regulated emissions show driving cycle dependency; and they are also improved with newer vehicle and emission control technology. However, a gasoline direct injection vehicle (relatively new technology in this study) has rather high regulated emissions, whereas the NH(3), N(2)O and HCN emissions are low.

  8. Balmer line diagnostic of electron heating at collisionless shocks in supernova remnants

    International Nuclear Information System (INIS)

    Rakowski, C.

    2008-01-01

    The mechanism and extent of electron heating at collisionless shocks has recently been under intense investigation. H α Balmer line emission is excited immediately behind the shock front and provides the best diagnostic for the electron to proton temperature ratio at supernova remnant shocks. Two components of emission are produced, a narrow component from electron and proton impact excitation of cold neutrals, and a broad component produced through charge exchange between the cold neutrals and the shock heated protons. Thus the broad and narrow component fluxes reflect the competition between electron and proton impact ionization, electron and proton impact excitation and charge exchange. This diagnostic has led to the discovery of an approximate inverse square relationship between the electron to proton temperature ratio and the shock velocity. In turn, this implies a constant level of electron heating, independent of shock speed above ∼ 450 km/s. In this talk I will present the observational evidence to date. Time permitting, I will introduce how lower-hybrid waves in an extended cosmic ray precursor could explain such a relationship, and how this and other parameters in the H α profile might relate to properties of cosmic rays and magnetic field amplification ahead of the shock. (author)

  9. Ammonia, hydrogen sulfide, carbon dioxide and particulate matter emissions from California high-rise layer houses

    Science.gov (United States)

    Lin, X.-J.; Cortus, E. L.; Zhang, R.; Jiang, S.; Heber, A. J.

    2012-01-01

    Ammonia and hydrogen sulfide are hazardous substances that are regulated by the U.S. Environmental Protection Agency through community right-to-know legislation (EPCRA, EPA, 2011). The emissions of ammonia and hydrogen sulfide from large commercial layer facilities are of concern to legislators and nearby neighbors. Particulate matter (PM 10 and PM 2.5) released from layer houses are two of seven criteria pollutants for which EPA has set National Ambient Air Quality Standards as required by the Clean Air Act. Therefore, it is important to quantify the baseline emissions of these pollutants. The emissions of ammonia, hydrogen sulfide, carbon dioxide and PM from two California high-rise layer houses were monitored for two years from October 2007 to October 2009. Each house had 32,500 caged laying hens. The monitoring site was setup in compliance with a U.S. EPA-approved quality assurance project plan. The results showed the average daily mean emission rates of ammonia, hydrogen sulfide and carbon dioxide were 0.95 ± 0.67 (standard deviation) g d -1 bird -1, 1.27 ± 0.78 mg d -1 bird -1 and 91.4 ± 16.5 g d -1 bird -1, respectively. The average daily mean emission rates of PM 2.5, PM 10 and total suspended particulate (TSP) were 5.9 ± 12.6, 33.4 ± 27.4, and 78.0 ± 42.7 mg d -1 bird -1, respectively. It was observed that ammonia emission rates in summer were lower than in winter because the high airflow stabilized the manure by drying it. The reductions due to lower moisture content were greater than the increases due to higher temperature. However, PM 10 emission rates in summer were higher than in winter because the drier conditions coupled with higher internal air velocities increased PM 10 release from feathers, feed and manure.

  10. Rate amplification of the two photon emission from para-hydrogen toward the neutrino mass measurement

    International Nuclear Information System (INIS)

    Masuda, Takahiko; Hara, Hideaki; Miyamoto, Yuki; Kuma, Susumu; Nakano, Itsuo; Ohae, Chiaki; Sasao, Noboru; Tanaka, Minoru; Uetake, Satoshi; Yoshimi, Akihiro; Yoshimura, Koji; Yoshimura, Motohiko

    2015-01-01

    We recently reported an experiment which focused on demonstrating the macro-coherent amplification mechanism. This mechanism, which was proposed for neutrino mass measurements, indicates that a multi-particle emission rate should be amplified by coherence in a suitable medium. Using a para-hydrogen molecule gas target and the adiabatic Raman excitation method, we observed that the two photon emission rate was amplified by a factor of more than 10 15 from the spontaneous emission rate. This paper briefly summarizes the previous experimental result and presents the current status and the future prospect

  11. Rate amplification of the two photon emission from para-hydrogen toward the neutrino mass measurement

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Takahiko, E-mail: masuda@okayama-u.ac.jp; Hara, Hideaki; Miyamoto, Yuki [Okayama University, Research Core for Extreme Quantum World (Japan); Kuma, Susumu [Atomic, Molecular and Optical Physics Laboratory, RIKEN (Japan); Nakano, Itsuo [Okayama University, Research Core for Extreme Quantum World (Japan); Ohae, Chiaki [University of Electro-Communications, Department of Engineering Science (Japan); Sasao, Noboru [Okayama University, Research Core for Extreme Quantum World (Japan); Tanaka, Minoru [Osaka University, Department of Physics (Japan); Uetake, Satoshi [Okayama University, Research Center of Quantum Universe (Japan); Yoshimi, Akihiro; Yoshimura, Koji [Okayama University, Research Core for Extreme Quantum World (Japan); Yoshimura, Motohiko [Okayama University, Research Center of Quantum Universe (Japan)

    2015-11-15

    We recently reported an experiment which focused on demonstrating the macro-coherent amplification mechanism. This mechanism, which was proposed for neutrino mass measurements, indicates that a multi-particle emission rate should be amplified by coherence in a suitable medium. Using a para-hydrogen molecule gas target and the adiabatic Raman excitation method, we observed that the two photon emission rate was amplified by a factor of more than 10{sup 15} from the spontaneous emission rate. This paper briefly summarizes the previous experimental result and presents the current status and the future prospect.

  12. Stratospheric cooling and polar ozone loss due to H2 emissions of a global hydrogen economy

    Science.gov (United States)

    Feck, T.; Grooß, J.-U.; Riese, M.; Vogel, B.

    2009-04-01

    "Green" hydrogen is seen as a major element of the future energy supply to reduce greenhouse gas emissions substantially. However, due to the possible interactions of hydrogen (H2) with other atmospheric constituents there is a need to analyse the implications of additional atmospheric H2 that could result from hydrogen leakage of a global hydrogen infrastructure. Emissions of molecular H2 can occur along the whole hydrogen process chain which increase the tropospheric H2 burden. Across the tropical tropopause H2 reaches the stratosphere where it is oxidised and forms water vapour (H2O). This causes increased IR-emissions into space and hence a cooling of the stratosphere. Both effects, the increase of stratospheric H2O and the cooling, enhances the potential of chlorine activation on liquid sulfate aerosol and polar stratospheric clouds (PSCs), which increase polar ozone destruction. Hence a global hydrogen economy could provoke polar ozone loss and could lead to a substantial delay of the current projected recovery of the stratospheric ozone layer. Our investigations show that even if 90% of the current global fossil primary energy input could be replaced by hydrogen and approximately 9.5% of the product gas would leak to the atmosphere, the ozone loss would be increased between 15 to 26 Dobson Units (DU) if the stratospheric CFC loading would retain unchanged. A consistency check of the used approximation methods with the Chemical Lagrangian Model of the Stratosphere (CLaMS) shows that this additional ozone loss can probably be treated as an upper limit. Towards more realistic future H2 leakage rate assumptions (< 3%) the additional ozone loss would be rather small (? 10 DU). However, in all cases the full damage would only occur if stratospheric CFC-levels would retain unchanged. Due to the CFC-prohibition as a result of the Montreal Protocol the forecasts suggest a decline of the stratospheric CFC loading about 50% until 2050. In this case our calculations

  13. Emissions of hydrogen cyanide from on-road gasoline and diesel vehicles

    Science.gov (United States)

    Moussa, Samar G.; Leithead, Amy; Li, Shao-Meng; Chan, Tak W.; Wentzell, Jeremy J. B.; Stroud, Craig; Zhang, Junhua; Lee, Patrick; Lu, Gang; Brook, Jeffery R.; Hayden, Katherine; Narayan, Julie; Liggio, John

    2016-04-01

    Hydrogen cyanide (HCN) is considered a marker for biomass burning emissions and is a component of vehicle exhaust. Despite its potential health impacts, vehicular HCN emissions estimates and their contribution to regional budgets are highly uncertain. In the current study, Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) was used to measure HCN emission factors from the exhaust of individual diesel, biodiesel and gasoline vehicles. Laboratory emissions data as a function of fuel type and driving mode were combined with ambient measurement data and model predictions. The results indicate that gasoline vehicles have the highest emissions of HCN (relative to diesel fuel) and that biodiesel fuel has the potential to significantly reduce HCN emissions even at realistic 5% blend levels. The data further demonstrate that gasoline direct injection (GDI) engines emit more HCN than their port fuel injection (PFI) counterparts, suggesting that the expected full transition of vehicle fleets to GDI will increase HCN emissions. Ambient measurements of HCN in a traffic dominated area of Toronto, Canada were strongly correlated to vehicle emission markers and consistent with regional air quality model predictions of ambient air HCN, indicating that vehicle emissions of HCN are the dominant source of exposure in urban areas. The results further indicate that additional work is required to quantify HCN emissions from the modern vehicle fleet, particularly in light of continuously changing engine, fuel and after-treatment technologies.

  14. Trace moisture emissions from heated metal surfaces in hydrogen service

    International Nuclear Information System (INIS)

    Funke, Hans H.; Yao Jianlong; Raynor, Mark W.

    2004-01-01

    The formation of trace moisture by exposure of dry heated surfaces of 316 L stainless-steel, Restek Silcosteel registered , and nickel 1/8 in. outer diameter line segments to purified Ar and H 2 was studied using atmospheric pressure ionization mass spectrometry at flow rates of 2 slpm. Prior to H 2 exposure, adsorbed moisture was removed by heating incrementally to 500 deg. C in an argon matrix, where the Restek Silcosteel registered material released a maximum of 50 ppb moisture at 300 deg. C and moisture spikes from the Ni and stainless-steel surfaces reached several 100 ppb. Upon exposure to H 2 , persistent low ppb moisture emissions due to the reduction of surface oxide species were observed at temperatures as low as 100 deg. C. Spikes at 300-500 deg. C ranged from ∼100 ppb for the stainless-steel lines to 400 ppb for the Restek Silcosteel registered material. The observed moisture emissions have to be considered as a potential contamination source for high-purity processes utilizing H 2 purge at elevated temperatures

  15. Relationship between the intensity of nonthermal radiation and widths of Balmer lines in the spectra of quasar-like nuclei

    International Nuclear Information System (INIS)

    Komberg, B.V.; Shefer, E.Yu.

    1983-01-01

    The data summarized by Steiner (1981) were used to derive the relationship between the intensity of nonthermal X-ray and radio emission and fullwidths of Balmer emission lines. It is shown that the existence of such dependences does not contradict the assumption on partition equidistribution of nonthermal radiation and motion of gas clouds energy in the region of formation of wide lines. Emphasis is given to similar dependence drived by Vayana (1981) for X-ray radiation from hot coronas of fast-rotating single stars, and a suggestion is made about radiation anisotropy from active nuclei (similar to that observed in the SS 433 system). The latter may imply the double nature of active nuclei

  16. Potentials of NO{sub X} emission reduction methods in SI hydrogen engines: Simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Safari, H.; Jazayeri, S.A. [Department of Mechanical Engineering, K.N. Toosi University of Technology, No.15, Pardis Street, Vanak Square, Tehran (Iran); Ebrahimi, R. [Department of Aerospace Engineering, K.N. Toosi University of Technology, 4th Tehranpars Square, East Vafadar Street, Tehran (Iran)

    2009-01-15

    The ever increasing cost of hydrocarbon fuels and more stringent emission standards may resolve challenges in producing hydrogen and using it as an alternative fuel in industries. Internal combustion engines are well-established technology and hydrogen fuel in such engines is considered as an attractive choice in exploiting clean, efficient and renewable hydrogen energy. This work presents an improved thermo-kinetics model for simulation of hydrogen combustion in SI engines. The turbulent propagating flame is modeled using turbulent burning velocity model. During combustion the charge is divided into three zones containing unburned charge, flame and burned gas. The adiabatic flame is assumed to be in thermodynamic equilibrium while the detailed chemical kinetics scheme is considered for burned and unburned zones. The results were first validated against published experiments. Good agreements were obtained between simulation and experiment for varying equivalence ratio, ignition timing and compression ratio. Detailed analysis of engine NO{sub X} emission was performed afterward. The lean-burn and EGR strategies' potentials were examined by the current model. The effects of different amounts of cooled dry EGR and hot wet EGR on the NO{sub X} emission, engine power output and indicated thermal efficiency were investigated and compared theoretically. (author)

  17. A measurement of deuterium neutral by the Balmer-series in the STP-2 high beta screw pinch tokamak

    International Nuclear Information System (INIS)

    Yamaguchi, S.; Hirano, K.

    1980-06-01

    The Balmer-alpha and beta are measured with a calibrated spectrograph in STP-2 screw pinch tokamak operated under the maximum toroidal field being 9.2 kG, peak plasma current 30 kA and filling pressure 5 mtorr. The electron temperature and density profiles are obtained by ruby laser Thomson scattering. It is shown that electron temperature is about 10 eV and density is of the order of 10 14 /cm 3 . A non-cylindrical symmetric Abel-inversion technique is used to deduce the emission coefficient profiles from that of the line intensity of the Balmer's. In the present parameter range the neutral deuterium density is almost equal to the population density of the ground state, so that it is obtainable from measured intensities of D sub(α) and D sub(β) which give the population densities of the upper levels i = 3 and 4. The Collisional Radiative (CR) model is applied to the rate equations to estimate the ground state population density. It is found that at 4 μsec from the start of the discharge the deuterium neutral density may be approximately 2 x 10 12 /cm 3 at the center of plasma and 2 x 10 14 /cm 3 at the periphery. These values may contain an error of about factor two. Time history of neutral deuterium density is consistent with the increase of plasma density. (author)

  18. Hydrogen Pathways: Updated Cost, Well-to-Wheels Energy Use, and Emissions for the Current Technology Status of Ten Hydrogen Production, Delivery, and Distribution Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Ramsden, T.; Ruth, M.; Diakov, V.; Laffen, M.; Timbario, T. A.

    2013-03-01

    This report describes a life-cycle assessment conducted by the National Renewable Energy Laboratory (NREL) of 10 hydrogen production, delivery, dispensing, and use pathways that were evaluated for cost, energy use, and greenhouse gas (GHG) emissions. This evaluation updates and expands on a previous assessment of seven pathways conducted in 2009. This study summarizes key results, parameters, and sensitivities to those parameters for the 10 hydrogen pathways, reporting on the levelized cost of hydrogen in 2007 U.S. dollars as well as life-cycle well-to-wheels energy use and GHG emissions associated with the pathways.

  19. Acoustic emission studies of cermet BK structural modifications under thermal and radiation action and hydrogenation

    International Nuclear Information System (INIS)

    Ul'yanov, V.L.; Chernov, I.P.; Botaki, A.A.; Chakhlov, B.V.

    1992-01-01

    Elastic wave attenuation and acoustic emission (AE) in tungsten monocarbide base cermets were investigated with the purpose of studying structural changes and microplastic strains under heating within the range of 100-1000 K, gamma-irradiation up to absorbed dose of 10 7 J·kg -1 and hydrogenation. Interrelations were revealed of AE signals and a decrement of elastic wave damping to temperature- and radiation-induced transformations in microstructure of 94 % WC -6 % Co and 92 % WC - 8 % Co hard alloys. AE peaks under thermal action were found to be associated with cobalt phase microstrain or with dislocation of hydrogen in preliminary hyudrogenated alloys

  20. Emission of blue light from hydrogenated amorphous silicon carbide

    Science.gov (United States)

    Nevin, W. A.; Yamagishi, H.; Yamaguchi, M.; Tawada, Y.

    1994-04-01

    THE development of new electroluminescent materials is of current technological interest for use in flat-screen full-colour displays1. For such applications, amorphous inorganic semiconductors appear particularly promising, in view of the ease with which uniform films with good mechanical and electronic properties can be deposited over large areas2. Luminescence has been reported1 in the red-green part of the spectrum from amorphous silicon carbide prepared from gas-phase mixtures of silane and a carbon-containing species (usually methane or ethylene). But it is not possible to achieve blue luminescence by this approach. Here we show that the use of an aromatic species-xylene-as the source of carbon during deposition results in a form of amorphous silicon carbide that exhibits strong blue luminescence. The underlying structure of this material seems to be an unusual combination of an inorganic silicon carbide lattice with a substantial 'organic' π-conjugated carbon system, the latter dominating the emission properties. Moreover, the material can be readily doped with an electron acceptor in a manner similar to organic semiconductors3, and might therefore find applications as a conductivity- or colour-based chemical sensor.

  1. The life cycle greenhouse gas emissions implications of power and hydrogen production for oil sands operations

    International Nuclear Information System (INIS)

    McKellar, J.M.; Bergerson, J.A.; MacLean, H.L.

    2009-01-01

    'Full text:' The Alberta Oil Sands represent a major economic opportunity for Canada, but the industry is also a significant source of greenhouse gas (GHG) emissions. One of the sources of these emissions is the use of natural gas for the production of electricity, steam and hydrogen. Due to concerns around resource availability and price volatility, there has been considerable discussion regarding the potential replacement of natural gas with an alternative fuel. While some of the options are non-fossil and could potentially reduce GHG emissions (e.g., nuclear, geothermal, biomass), others have the potential to increase emissions. A comparative life cycle assessment was completed to investigate the relative GHG emissions, energy consumption and financial implications of replacing natural gas with coal, coke, asphaltenes or bitumen for the supply of electricity, steam and hydrogen to oil sands operations. The potential use of carbon capture and storage (CCS) was also investigated as a means of reducing GHG emissions. Preliminary results indicate that, without CCS, the natural gas systems currently in use have lower life cycle GHG emissions than gasification systems using any of the alternative fuels analysed. However, when CCS is implemented in both the coke gasification and natural gas systems, the coke systems have lower GHG emissions and financial costs than the natural gas systems (assuming a 30-year project life and a natural gas price of 6.5 USD/gigajoule). The use of CCS does impose a financial penalty though, indicating that it is unlikely to be implemented without some financial incentive. While this study has limitations and uncertainties, the preliminary results indicate that although the GHG emissions of oil sands development pose a challenge to Canada, there are opportunities available for their abatement. (author)

  2. Nebular dust and extinction in ionized nebulae i.. the Balmer decrement

    International Nuclear Information System (INIS)

    Mathis, J.S.

    1983-01-01

    Many astronomical objects contain plasma with internal or surrounding dust. The extinction of H II regions can be determined from the H#betta#/Hα flux ratio, and also from the H#betta#/radio fluxes. The two determinations almost always disagree by large factors (typically, approx.3), with the (H#betta#/Hα) extinction being smaller. This is shown to be a consequence of the albedo of dust at Hα being smaller than that of H#betta#, so that the destruction of Hα by dust is larger than for constant albedo. If the difference in albedo is ignored, one interprets the lower Hα flux as being caused by a small optical depth in dust. Simple models for the geometry of the dust and emitting gas are discussed: spherical models with dust mixed with the ionized gas, and also a slab of absorbing dust overlying the nebula. The two geometries give similar results for the Balmer decrements, so geometry does not strongly enter the final results. The conclusion that albedo (Hα) 8000 A). Recommendations for dereddening emission-line objects are presented and should be applicable to planetary nebulae, active galactic nuclei, or quasi-stellar objects as well as to H II regions

  3. Emission ratio and isotopic signatures of molecular hydrogen emissions from tropical biomass burning

    NARCIS (Netherlands)

    Haumann, F.A.; Batenburg, A.M.; Pieterse, G.; Gerbig, C.; Krol, M.C.; Rockmann, T.

    2013-01-01

    In this study, we identify a biomass-burning signal in molecular hydrogen (H-2) over the Amazonian tropical rainforest. To quantify this signal, we measure the mixing ratios of H-2 and several other species as well as the H-2 isotopic composition in air samples that were collected in the BARCA

  4. Emission ratio and isotopic signatures of molecular hydrogen emissions from tropical biomass burning

    NARCIS (Netherlands)

    Haumann, F.A.; Batenburg, A.M.; Pieterse, G.; Gerbig, C; Krol, M.C.; Röckmann, T.

    2013-01-01

    In this study, we identify a biomass-burning signal in molecular hydrogen (H2) over the Amazonian tropical rainforest. To quantify this signal, we measure the mixing ratios of H2 and several other species as well as the H2 isotopic composition in air samples that were collected in the BARCA (Balanço

  5. Modeling of Spray System Operation under Hydrogen and Steam Emissions in NPP Containment during Severe Accident

    Directory of Open Access Journals (Sweden)

    Vadim E. Seleznev

    2011-01-01

    Full Text Available The paper describes one of the variants of mathematical models of a fluid dynamics process inside the containment, which occurs in the conditions of operation of spray systems in severe accidents at nuclear power plant. The source of emergency emissions in this case is the leak of the coolant or rupture at full cross-section of the main circulating pipeline in a reactor building. Leak or rupture characteristics define the localization and the temporal law of functioning of a source of emergency emission (or accrued operating of warmed up hydrogen and steam in the containment. Operation of this source at the course of analyzed accident models should be described by the assignment of the relevant Dirichlet boundary conditions. Functioning of the passive autocatalytic recombiners of hydrogen is described in the form of the complex Newton boundary conditions.

  6. Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

    Directory of Open Access Journals (Sweden)

    Burmistrz Piotr

    2016-01-01

    Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

  7. Effect of Hydrogen Addition on Methane HCCI Engine Ignition Timing and Emissions Using a Multi-zone Model

    Science.gov (United States)

    Wang, Zi-han; Wang, Chun-mei; Tang, Hua-xin; Zuo, Cheng-ji; Xu, Hong-ming

    2009-06-01

    Ignition timing control is of great importance in homogeneous charge compression ignition engines. The effect of hydrogen addition on methane combustion was investigated using a CHEMKIN multi-zone model. Results show that hydrogen addition advances ignition timing and enhances peak pressure and temperature. A brief analysis of chemical kinetics of methane blending hydrogen is also performed in order to investigate the scope of its application, and the analysis suggests that OH radical plays an important role in the oxidation. Hydrogen addition increases NOx while decreasing HC and CO emissions. Exhaust gas recirculation (EGR) also advances ignition timing; however, its effects on emissions are generally the opposite. By adjusting the hydrogen addition and EGR rate, the ignition timing can be regulated with a low emission level. Investigation into zones suggests that NOx is mostly formed in core zones while HC and CO mostly originate in the crevice and the quench layer.

  8. Effect of dietary nitrate level on enteric methane production, hydrogen emission, rumen fermentation, and nutrient digestibility in dairy cows

    NARCIS (Netherlands)

    Olijhoek, D.W.; Hellwing, A.L.F.; Brask, M.; Weisbjerg, M.R.; Højberg, O.; Larsen, M.K.; Dijkstra, Jan; Erlandsen, E.J.; Lund, P.

    2016-01-01

    Nitrate may lower methane production in ruminants by competing with methanogenesis for available hydrogen in the rumen. This study evaluated the effect of 4 levels of dietary nitrate addition on enteric methane production, hydrogen emission, feed intake, rumen fermentation, nutrient

  9. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Standards to control hydrogen chloride... WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions...

  10. Performance and emission characteristics of a turbocharged CNG engine fueled by hydrogen-enriched compressed natural gas with high hydrogen ratio

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Fanhua; Wang, Mingyue; Jiang, Long; Chen, Renzhe; Deng, Jiao; Naeve, Nashay; Zhao, Shuli [State Key Laboratory of Automotive Safety and Energy Tsinghua University, Beijing 100084 (China)

    2010-06-15

    This paper investigates the effect of high hydrogen volumetric ratio of 55% on performance and emission characteristics in a turbocharged lean burn natural gas engine. The experimental data was conducted under various operating conditions including different spark timing, excess air ratio (lambda), and manifold pressure. It is found that the addition of hydrogen at a high volumetric ratio could significantly extend the lean burn limit, improve the engine lean burn ability, decrease burn duration, and yield higher thermal efficiency. The CO, CH{sub 4} emissions were reduced and NO{sub x} emission could be kept an acceptable low level with high hydrogen content under lean burn conditions when ignition timing were optimized. (author)

  11. Effect of hydrogen addition on combustion and emissions performance of a gasoline rotary engine at part load and stoichiometric conditions

    International Nuclear Information System (INIS)

    Ji, Changwei; Su, Teng; Wang, Shuofeng; Zhang, Bo; Yu, Menghui; Cong, Xiaoyu

    2016-01-01

    Highlights: • The performance of a H_2-blended gasoline rotary engine was studied. • The p, Bmep, T_m_a_x and η_b increased after H_2 blending. • Both the CA0-10 and CA10-90 were shortened by the H_2 addition. • H_2 addition resulted in the reduced HC, CO and CO_2 emissions. - Abstract: The rotary engines may encounter high fuel consumption and emissions due to its narrow and long combustion chamber design. The low ignition energy and high flame speed of hydrogen may help improve the combustion of rotary engines. In this paper, a gasoline rotary engine equipped with gasoline and hydrogen injectors was developed to investigate the combustion and emissions of hydrogen-blended gasoline rotary engines. The engine was run at 3000 rpm and a manifolds absolute pressure of 37.5 kPa with the stoichiometric excess air ratio. The spark timing was set to be 25°CA before the top dead center. The engine was first fueled with the pure gasoline and then blended with the hydrogen. The hydrogen volume fractions in the intake were gradually increased from 0% to 5.2%. The results showed that the combustion pressure, brake mean effective pressure, cylinder temperature and thermal efficiency were simultaneously increased after the hydrogen blending. The crank angle of peak pressure was advanced with the hydrogen addition. The hydrogen enrichment was effective on reducing flame development and propagation periods. HC emissions were reduced by 44.8% when the hydrogen volume fraction in the intake was raised from 0% to 5.2%, CO and CO_2 emissions were also reduced after the hydrogen blending.

  12. The Effect of Converting to a U.S. Hydrogen Fuel Cell Vehicle Fleet on Emissions and Energy Use

    Science.gov (United States)

    Colella, W. G.; Jacobson, M. Z.; Golden, D. M.

    2004-12-01

    This study analyzes the potential change in emissions and energy use from replacing fossil-fuel based vehicles with hydrogen fuel cell vehicles. This study examines three different hydrogen production scenarios to determine their resultant emissions and energy usage: hydrogen produced via 1) steam reforming of methane, 2) coal gasification, or 3) wind electrolysis. The atmospheric model simulations require two primary sets of data: the actual emissions associated with hydrogen fuel production and use, and the corresponding reduction in emissions associated with reducing fossil fuel use. The net change in emissions is derived using 1) the U.S. EPA's National Emission Inventory (NEI) that incorporates several hundred categories of on-road vehicles and 2) a Process Chain Analysis (PCA) for the different hydrogen production scenarios. NEI: The quantity of hydrogen-related emission is ultimately a function of the projected hydrogen consumption in on-road vehicles. Data for hydrogen consumption from on-road vehicles was derived from the number of miles driven in each U.S. county based on 1999 NEI data, the average fleet mileage of all on-road vehicles, the average gasoline vehicle efficiency, and the efficiency of advanced 2004 fuel cell vehicles. PCA: PCA involves energy and mass balance calculations around the fuel extraction, production, transport, storage, and delivery processes. PCA was used to examine three different hydrogen production scenarios: In the first scenario, hydrogen is derived from natural gas, which is extracted from gas fields, stored, chemically processed, and transmitted through pipelines to distributed fuel processing units. The fuel processing units, situated in similar locations as gasoline refueling stations, convert natural gas to hydrogen via a combination of steam reforming and fuel oxidation. Purified hydrogen is compressed for use onboard fuel cell vehicles. In the second scenario, hydrogen is derived from coal, which is extracted from

  13. Kinetic Monte-Carlo modeling of hydrogen retention and re-emission from Tore Supra deposits

    International Nuclear Information System (INIS)

    Rai, A.; Schneider, R.; Warrier, M.; Roubin, P.; Martin, C.; Richou, M.

    2009-01-01

    A multi-scale model has been developed to study the reactive-diffusive transport of hydrogen in porous graphite [A. Rai, R. Schneider, M. Warrier, J. Nucl. Mater. (submitted for publication). http://dx.doi.org/10.1016/j.jnucmat.2007.08.013.]. The deposits found on the leading edge of the neutralizer of Tore Supra are multi-scale in nature, consisting of micropores with typical size lower than 2 nm (∼11%), mesopores (∼5%) and macropores with a typical size more than 50 nm [C. Martin, M. Richou, W. Sakaily, B. Pegourie, C. Brosset, P. Roubin, J. Nucl. Mater. 363-365 (2007) 1251]. Kinetic Monte-Carlo (KMC) has been used to study the hydrogen transport at meso-scales. Recombination rate and the diffusion coefficient calculated at the meso-scale was used as an input to scale up and analyze the hydrogen transport at macro-scale. A combination of KMC and MCD (Monte-Carlo diffusion) method was used at macro-scales. Flux dependence of hydrogen recycling has been studied. The retention and re-emission analysis of the model has been extended to study the chemical erosion process based on the Kueppers-Hopf cycle [M. Wittmann, J. Kueppers, J. Nucl. Mater. 227 (1996) 186].

  14. A Far-ultraviolet Fluorescent Molecular Hydrogen Emission Map of the Milky Way Galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Young-Soo; Min, Kyoung-Wook [Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Seon, Kwang-Il; Han, Wonyong [Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Edelstein, Jerry, E-mail: stspeak@gmail.com [Space Sciences Laboratory, University of California, Berkeley, CA, 94720 (United States)

    2017-08-01

    We present the far-ultraviolet (FUV) fluorescent molecular hydrogen (H{sub 2}) emission map of the Milky Way Galaxy obtained with FIMS/SPEAR covering ∼76% of the sky. The extinction-corrected intensity of the fluorescent H{sub 2} emission has a strong linear correlation with the well-known tracers of the cold interstellar medium (ISM), including color excess E(B–V) , neutral hydrogen column density N (H i), and H α emission. The all-sky H{sub 2} column density map was also obtained using a simple photodissociation region model and interstellar radiation fields derived from UV star catalogs. We estimated the fraction of H{sub 2} ( f {sub H2}) and the gas-to-dust ratio (GDR) of the diffuse ISM. The f {sub H2} gradually increases from <1% at optically thin regions where E(B–V) < 0.1 to ∼50% for E(B–V)  = 3. The estimated GDR is ∼5.1 × 10{sup 21} atoms cm{sup −2} mag{sup −1}, in agreement with the standard value of 5.8 × 10{sup 21} atoms cm{sup −2} mag{sup −1}.

  15. Effects of thin films on inventory, permeation and re-emission of energetic hydrogen

    International Nuclear Information System (INIS)

    Ohyabu, N.; Nakamura, Y.; Nakahara, Y.; Livshits, A.; Alimov, V.; Busnyuk, A.; Notkin, M.; Samartsev, A.; Doroshin, A.

    2000-01-01

    A non-metallic coating thicker than the implantation depth may protect a metal against tritium retention and permeation. However, a thinner film has quite the opposite effect: a dramatic increase of permeation and retention, and a corresponding suppression of re-emission. In view of the benefits expected from particle control with a superpermeable membrane placed right inside the divertor, the behavior of a Nb sample was investigated in a plasma-membrane device having a graphite target. Even polyatomic carbide coating was found not to hinder hydrogen absorption and permeation. Polyatomic non-carbide C films effectively inhibits it, but the formation of such films depends on H and C fluxes, H energy and metal temperature. A durable isolation of suprathermal hydrogen with the superpermeable membrane was observed at a high enough ratio between H and C fluxes, and the effects of carbon were found to have a non-monotonic temperature dependence

  16. Combined borax and tannin treatment of stored dairy manure to reduce bacterial populations and hydrogen sulfide emissions

    Science.gov (United States)

    Background: Anaerobic digestion of organic residues in stored livestock manure is associated with the production of odors and emissions. Hydrogen sulfide (H2S) is one such emission that can reach hazardous levels during manure storage and handling, posing a risk to both farmers and livestock. New te...

  17. Renewable biocatalyst for swine manure treatment and mitigation of odorous VOCs, ammonia and hydrogen sulfide emissions: Review

    Science.gov (United States)

    Comprehensive control of odors, hydrogen sulfide (H2S), ammonia (NH3), and greenhouse gas (GHG) emissions associated with swine production is a critical need. The objective of this paper is to review the use of soybean peroxidase (SBP) and peroxides as a manure additive to mitigate emissions of odor...

  18. 40 CFR Table 4 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits 4 Table 4 to Subpart DDDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS...

  19. Estimating Anthropogenic Emissions of Hydrogen Chloride and Fine Particulate Chloride in China

    Science.gov (United States)

    Fu, X.; Wang, T.; Wang, S.; Zhang, L.

    2017-12-01

    Nitryl chloride (ClNO2) can significantly impact the atmospheric photochemistry via photolysis and subsequent reactions of chlorine radical with other gases. The formation of ClNO2 in the atmosphere is sensitive to the emissions of chlorine-containing particulates from oceanic and anthropogenic sources. For China, the only available anthropogenic chlorine emission inventory was compiled for the year 1990 with a coarse resolution of 1 degree. In this study, we developed an up-to-date anthropogenic inventory of hydrogen chloride (HCl) and fine particulate chloride (Cl-) emissions in China for the year 2014, including coal burning, industrial processes, biomass burning and waste burning. Bottom-up and top-down methodologies were combined. Detailed local data (e.g. Cl content in coal, control technologies, etc.) were collected and applied. In order to improve the spatial resolution of emissions, detailed point source information were collected for coal-fired power plants, cement factories, iron & steel factories and waste incineration factories. Uncertainties of this emission inventory and their major causes were analyzed using the Monte Carlo method. This work enables better quantification of the ClNO2 production and impact over China.

  20. Effect of hydrogen on ethanol-biodiesel blend on performance and emission characteristics of a direct injection diesel engine.

    Science.gov (United States)

    Parthasarathy, M; Isaac JoshuaRamesh Lalvani, J; Dhinesh, B; Annamalai, K

    2016-12-01

    Environment issue is a principle driving force which has led to a considerable effort to develop and introduce alternative fuels for transportation. India has large potential for production of biofuels like biodiesel from vegetable seeds. Use of biodiesel namely, tamanu methyl ester (TME) in unmodified diesel engines leads to low thermal Efficiency and high smoke emission. To encounter this problem hydrogen was inducted by a port fueled injection system. Hydrogen is considered to be low polluting fuel and is the most promising among alternative fuel. Its clean burning characteristic and better performance attract more interest compared to other fuels. It was more active in reducing smoke emission in biodiesel. A main drawback with hydrogen fuel is the increased NO x emission. To reduce NO x emission, TME-ethanol blends were used in various proportions. After a keen study, it was observed that ethanol can be blended with biodiesel up to 30% in unmodified diesel engine. The present work deals with the experimental study of performance and emission characteristic of the DI diesel engine using hydrogen and TME-ethanol blends. Hydrogen and TME-ethanol blend was used to improve the brake thermal efficiency and reduction in CO, NO x and smoke emissions. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Fast and reliable method for computing free-bound emission coefficients for hydrogenic ions

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento, A; Canto, J

    1985-12-01

    An approximate formula for the computation of the free-bound emission coefficient for hydrogenic ions is presented. The approximation is obtained through a manipulation of the (free-bound) Gaunt factor which intentionally distinguish the dependence on frequency from the dependence on temperature and ionic composition. Numerical tests indicate that the derived formula is very precise, fast and easy to use, making the calculation of the free-bound contribution from an ionized region of varying temperature and ionic composition a very simple and time-saving task.

  2. A fast and reliable method for computing free-bound emission coefficients for hydrogenic ions

    International Nuclear Information System (INIS)

    Sarmiento, A.; Canto, J.

    1985-01-01

    An approximate formula for the computation of the free-bound emission coefficient for hydrogenic ions is presented. The approximation is obtained through a manipulation of the (free-bound) Gaunt factor which intentionally distinguish the dependence on frequency from the dependence on temperature and ionic composition. Numerical tests indicate that the derived formula is very precise, fast and easy to use, making the calculation of the free-bound contribution from an ionized region of varying temperature and ionic composition a very simple and time-saving task. (author)

  3. 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.

  4. Particle-in-cell modeling of the nanosecond field emission driven discharge in pressurized hydrogen

    Science.gov (United States)

    Levko, Dmitry; Yatom, Shurik; Krasik, Yakov E.

    2018-02-01

    The high-voltage field-emission driven nanosecond discharge in pressurized hydrogen is studied using the one-dimensional Particle-in-Cell Monte Carlo collision model. It is obtained that the main part of the field-emitted electrons becomes runaway in the thin cathode sheath. These runaway electrons propagate the entire cathode-anode gap, creating rather dense (˜1012 cm-3) seeding plasma electrons. In addition, these electrons initiate a streamer propagating through this background plasma with a speed ˜30% of the speed of light. Such a high streamer speed allows the self-acceleration mechanism of runaway electrons present between the streamer head and the anode to be realized. As a consequence, the energy of runaway electrons exceeds the cathode-anode gap voltage. In addition, the influence of the field emission switching-off time is analyzed. It is obtained that this time significantly influences the discharge dynamics.

  5. Recombination dominated hydrogenic emission from the detached plasmas in W7-AS

    International Nuclear Information System (INIS)

    Ramasubramanian, N.; Koenig, R.; Wenzel, U.; Thomsen, H.; McCormick, K.; Grigull, P.; Feng, Y.; Klinger, T.; John, A.

    2003-01-01

    Beyond a certain threshold average density in the High-Density H-Mode the island divertor plasma in the stellarator W7-AS undergoes partial detachment. The tomographic reconstruction of the radiated power density from the detached pulses show that the radiation profile in the triangular plane is also asymmetric. In the detached phase, the spectrometer viewing tangentially to the target tiles in the top divertor region manifests that the impurity radiation layer is close to the X-points. The spectral analysis also demonstrates the presence of a hydrogen radiation zone dominated by recombination emission close to the target tiles. This papers presents the emission from the deeply detached locations including the volume recombination in a stable discharge. (orig.)

  6. Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

    International Nuclear Information System (INIS)

    Saravanan, N.; Nagarajan, G.

    2010-01-01

    Automobiles are one of the major sources of air pollution in the environment. In addition CO 2 emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 o crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 o CA before gas exchange top dead centre (BGTDC) with injection duration of 30 o CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO X emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO 2 ) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of hydrogen

  7. Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, N. [ERC Engines, Tata Motors, Pimpri, Pune (India); Nagarajan, G. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai (India)

    2010-07-15

    Automobiles are one of the major sources of air pollution in the environment. In addition CO{sub 2} emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 CA before gas exchange top dead centre (BGTDC) with injection duration of 30 CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO{sub X} emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO{sub 2}) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of

  8. The cathode-fall of low-pressure hydrogen discharges: Absolute spectral emission and model

    Energy Technology Data Exchange (ETDEWEB)

    Jelenkovic, B. M. [JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, Colorado 80309-0440 (United States); Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Zenum Belgrade (Serbia); Phelps, A. V. [JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, Colorado 80309-0440 (United States)

    2011-10-15

    Absolute excitation probabilities from very low to moderate-current hydrogen discharges in parallel-plane geometry are measured and used to test models. Relative emission data are obtained for the H{sub {alpha}} line, the H{sub 2} (a{sup 3}{Sigma}{yields}b{sup 3}{Pi}) near-UV continuum, and the H{sub 2} (G{sup 1}{Sigma}{yields}B{sup 1}{Pi}{sub u}{sup +}) band at pressures of 0.5 and 2 Torr, a 1.05 cm gap, and voltages from 300 to 900 V. Electron behavior is traced using the first negative (A{sup 2}{Sigma}{sub g}{yields} X{sup 2}{Pi}{sub u}, {nu}'' = 0 {yields}{nu}' = 0) band of N{sub 2}{sup +} by adding 2% N{sub 2}. Relative measurements of H{sub {alpha}}, H{sub 2} near-UV, and N{sub 2} 1st negative emission are placed on a absolute scale by normalization to published measurements and Boltzmann calculations of electron excitation. Emission probabilities calculated using a multi-beam kinetics model for the electrons, H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +}, H{sup -}, H, and H{sub 2} are compared with the calibrated experiments. Fast H atoms are calculated to produce H{sub {alpha}} excitation that is comparable with that of electrons. The calculated emission intensities for H{sub {alpha}} and H{sub 2} near-UV continuum are within a factor of three of the absolute measurements for a range of 5000:1 in current and 4:1 in hydrogen pressure. Calculations at 2 Torr show that most of the space charge electric field responsible for the cathode fall is produced by H{sub 3}{sup +} ions.

  9. Potential for greenhouse gas emission reductions using surplus electricity in hydrogen, methane and methanol production via electrolysis

    International Nuclear Information System (INIS)

    Uusitalo, Ville; Väisänen, Sanni; Inkeri, Eero; Soukka, Risto

    2017-01-01

    Highlights: • Greenhouse gas emission reductions using power-to-x processes are studied using life cycle assessment. • Surplus electricity use led to greenhouse gas emission reductions in all studied cases. • Highest reductions can be achieved by using hydrogen to replace fossil based hydrogen. • High reductions are also achieved when fossil transportation fuels are replaced. - Abstract: Using a life cycle perspective, potentials for greenhouse gas emission reductions using various power-to-x processes via electrolysis have been compared. Because of increasing renewable electricity production, occasionally surplus renewable electricity is produced, which leads to situations where the price of electricity approach zero. This surplus electricity can be used in hydrogen, methane and methanol production via electrolysis and other additional processes. Life cycle assessments have been utilized to compare these options in terms of greenhouse gas emission reductions. All of the power-to-x options studied lead to greenhouse gas emission reductions as compared to conventional production processes based on fossil fuels. The highest greenhouse gas emission reductions can be gained when hydrogen from steam reforming is replaced by hydrogen from the power-to-x process. High greenhouse gas emission reductions can also be achieved when power-to-x products are utilized as an energy source for transportation, replacing fossil transportation fuels. A third option with high greenhouse gas emission reduction potential is methane production, storing and electricity conversion in gas engines during peak consumption hours. It is concluded that the power-to-x processes provide a good potential solution for reducing greenhouse gas emissions in various sectors.

  10. BLACK HOLE MASS ESTIMATES BASED ON C IV ARE CONSISTENT WITH THOSE BASED ON THE BALMER LINES

    Energy Technology Data Exchange (ETDEWEB)

    Assef, R. J.; Denney, K. D.; Kochanek, C. S.; Peterson, B. M.; Kozlowski, S.; Dietrich, M.; Grier, C. J.; Khan, R. [Department of Astronomy, The Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Ageorges, N.; Buschkamp, P.; Gemperlein, H.; Hofmann, R. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstr., D-85748 Garching (Germany); Barrows, R. S. [Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Falco, E.; Kilic, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Feiz, C.; Germeroth, A. [Landessternwarte, ZAH, Koenigstuhl 12, D-69117 Heidelberg (Germany); Juette, M.; Knierim, V. [Astron. Institut der Ruhr Univ. Bochum, Universitaetsstr. 150, D-44780 Bochum (Germany); Laun, W., E-mail: rjassef@astronomy.ohio-state.edu [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); and others

    2011-12-01

    Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on the C IV, H{alpha}, and H{beta} broad emission lines. Our sample is based upon that of Greene, Peng, and Ludwig, expanded with new near-IR spectroscopic observations, consistently analyzed high signal-to-noise ratio (S/N) optical spectra, and consistent continuum luminosity estimates at 5100 A. We find that BH mass estimates based on the full width at half-maximum (FWHM) of C IV show a systematic offset with respect to those obtained from the line dispersion, {sigma}{sub l}, of the same emission line, but not with those obtained from the FWHM of H{alpha} and H{beta}. The magnitude of the offset depends on the treatment of the He II and Fe II emission blended with C IV, but there is little scatter for any fixed measurement prescription. While we otherwise find no systematic offsets between C IV and Balmer line mass estimates, we do find that the residuals between them are strongly correlated with the ratio of the UV and optical continuum luminosities. This means that much of the dispersion in previous comparisons of C IV and H{beta} BH mass estimates are due to the continuum luminosities rather than to any properties of the lines. Removing this dependency reduces the scatter between the UV- and optical-based BH mass estimates by a factor of approximately two, from roughly 0.35 to 0.18 dex. The dispersion is smallest when comparing the C IV {sigma}{sub l} mass estimate, after removing the offset from the FWHM estimates, and either Balmer line mass estimate. The correlation with the continuum slope is likely due to a combination of reddening, host contamination, and object-dependent SED shapes. When we add additional heterogeneous measurements from the literature, the results are unchanged. Moreover, in a trial observation of a

  11. Development of advanced claddings for suppressing the hydrogen emission in accident conditions. Development of advanced claddings for suppressing the hydrogen emission in the accident condition

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; KIM, Hyun-Gil; JUNG, Yang-Il; PARK, Dong-Jun; KOO, Yang-Hyun

    2013-01-01

    The development of accident-tolerant fuels can be a breakthrough to help solve the challenge facing nuclear fuels. One of the goals to be reached with accident-tolerant fuels is to reduce the hydrogen emission in the accident condition by improving the high-temperature oxidation resistance of claddings. KAERI launched a new project to develop the accident-tolerant fuel claddings with the primary objective to suppress the hydrogen emission even in severe accident conditions. Two concepts are now being considered as hydrogen-suppressed cladding. In concept 1, the surface modification technique was used to improve the oxidation resistance of Zr claddings. Like in concept 2, the metal-ceramic hybrid cladding which has a ceramic composite layer between the Zr inner layer and the outer surface coating is being developed. The high-temperature steam oxidation behaviour was investigated for several candidate materials for the surface modification of Zr claddings. From the oxidation tests carried out in 1 200 deg. C steam, it was found that the high-temperature steam oxidation resistance of Cr and Si was much higher than that of zircaloy-4. Al 3 Ti-based alloys also showed extremely low-oxidation rate compared to zircaloy-4. One important part in the surface modification is to develop the surface coating technology where the optimum process needs to be established depending on the surface layer materials. Several candidate materials were coated on the Zr alloy specimens by a laser beam scanning (LBS), a plasma spray (PS) and a PS followed by LBS and subject to the high-temperature steam oxidation test. It was found that Cr and Si coating layers were effective in protecting Zr-alloys from the oxidation. The corrosion behaviour of the candidate materials in normal reactor operation condition such as 360 deg. C water will be investigated after the screening test in the high-temperature steam. The metal-ceramic hybrid cladding consisted of three major parts; a Zr liner, a

  12. Effectiveness of oxygen enriched hydrogen-HHO gas addition on DI diesel engine performance, emission and combustion characteristics

    Directory of Open Access Journals (Sweden)

    Premkartikkumar S.R.

    2014-01-01

    Full Text Available Nowadays, more researches focus on protecting the environment. Present investigation concern with the effectiveness of Oxygen Enriched hydrogen- HHO gas addition on performance, emission and combustion characteristics of a DI diesel engine. Here the Oxygen Enriched hydrogen-HHO gas was produced by the process of water electrolysis. When potential difference is applied across the anode and cathode electrodes of the electrolyzer, water is transmuted into Oxygen Enriched hydrogen-HHO gas. The produced gas was aspirated into the cylinder along with intake air at the flow rates of 1 lpm and 3.3 lpm. The results show that when Oxygen Enriched hydrogen-HHO gas was inducted, the brake thermal efficiency of the engine increased by 11.06%, Carbon monoxide decreased by 15.38%, Unburned hydrocarbon decreased by 18.18%, Carbon dioxide increased by 6.06%, however, the NOX emission increased by 11.19%.

  13. Experimental investigation of solid hydrogen pellet ablation in high-temperature plasmas using holographic interferometry and other diagnostics

    International Nuclear Information System (INIS)

    Thomas, C.E. Jr.

    1981-03-01

    The technology currently most favored for the refueling of fusion reactors is the high-velocity injection of solid hydrogen pellets. Design details are presented for a holographic interferometer/shadowgraph used to study the microscopic characteristics of a solid hydrogen pellet ablating in an approx. 1-keV plasma. Experimental data are presented for two sets of experiments in which the interferometer/shadowgraph was used to study approx. 1-mm-diam solid hydrogen pellets injected into the Impurity Study Experiment (ISX-B) tokamak at Oak Ridge National Laboratory (ORNL) at velocities of 1000 m/s. In addition to the use of the holographic interferometer, the pellet ablation process is diagnosed by studying the emission of Balmer-alpha photons and by using the available tokamak diagnostics

  14. Study of interplanetary hydrogen from Lyman alpha emission and absorption determination

    International Nuclear Information System (INIS)

    Cazes, Serge.

    1979-09-01

    The purpose of the work submitted in this paper is to contribute to the study of interplanetary hydrogen from Lyman alpha emission and absorption measurements, carried out on board the D2A, OSO-8 and Copernicus satellites. This study, which was undertaken from the D2A satellite, moved us to study the interplanetary environment as from observations made from the following experiments placed on board the OSO-8 and Copernicus satellites. The experiment set up on board the OSO-8 satellite made it possible to obtain the profile of the solar alpha Lyman emission. An absorption profile was observed for the first time on these profiles and this made it possible to attribute them to interplanetary hydrogen and enabled us to make a direct and local determination of the solar ionization rate. - The spectrometer set up on board Copernicus made it possible to obtain the emission spectrum of the interplanetary environment at the same time as the geocorona. The overall velocity of the interplanetary environment was deduced from the Doppler shift between the two spectra. In the first part, the principle of the REA and POLAR experiments is recalled but only the REA experiment is described in detail, particularly the problems arising from the construction and calibration of the cell. In the second part, a study of the interplanetary environment made from the D2A determinations is presented in synthesized form. On the other hand, the study to which theses initial results led us is presented in detail. Finally, in the third part, the results obtained by means of the OSO-8 and Copernicus satellites are given [fr

  15. Strongly lensed neutral hydrogen emission: detection predictions with current and future radio interferometers

    Science.gov (United States)

    Deane, R. P.; Obreschkow, D.; Heywood, I.

    2015-09-01

    Strong gravitational lensing provides some of the deepest views of the Universe, enabling studies of high-redshift galaxies only possible with next-generation facilities without the lensing phenomenon. To date, 21-cm radio emission from neutral hydrogen has only been detected directly out to z ˜ 0.2, limited by the sensitivity and instantaneous bandwidth of current radio telescopes. We discuss how current and future radio interferometers such as the Square Kilometre Array (SKA) will detect lensed H I emission in individual galaxies at high redshift. Our calculations rely on a semi-analytic galaxy simulation with realistic H I discs (by size, density profile and rotation), in a cosmological context, combined with general relativistic ray tracing. Wide-field, blind H I surveys with the SKA are predicted to be efficient at discovering lensed H I systems, increasingly so at z ≳ 2. This will be enabled by the combination of the magnification boosts, the steepness of the H I luminosity function at the high-mass end, and the fact that the H I spectral line is relatively isolated in frequency. These surveys will simultaneously provide a new technique for foreground lens selection and yield the highest redshift H I emission detections. More near term (and existing) cm-wave facilities will push the high-redshift H I envelope through targeted surveys of known lenses.

  16. Reduction of greenhouse gas emission on a medium-pressure boiler using hydrogen-rich fuel control

    International Nuclear Information System (INIS)

    Hsieh, S.-C.; Jou, Chih-Ju G.

    2007-01-01

    The increasing emission of greenhouse gases from the combustion of fossil fuel is believed to be responsible for global warming. A study was carried out to probe the influence of replacing fuel gas with hydrogen-rich refinery gas (R.G.) on the reduction of gas emission (CO 2 and NO x ) and energy saving. Test results show that the emission of CO 2 can be reduced by 16.4% annually (or 21,500 tons per year). The NO x emission can be 8.2% lower, or 75 tons less per year. Furthermore, the use of refinery gas leads to a saving of NT$57 million (approximately US$1.73 million) on fuel costs each year. There are no CO 2 , CO, SO x , unburned hydrocarbon, or particles generated from the combustion of added hydrogen. The hydrogen content in R.G. employed in this study was between 50 and 80 mol%, so the C/H ratio of the feeding fuel was reduced. Therefore, the use of hydrogen-rich fuel has practical benefits for both energy saving and the reduction of greenhouse gas emission

  17. Effect of CO_2 dilution on combustion and emissions characteristics of the hydrogen-enriched gasoline engine

    International Nuclear Information System (INIS)

    Wang, Shuofeng; Ji, Changwei; Zhang, Bo; Cong, Xiaoyu; Liu, Xiaolong

    2016-01-01

    CO_2 (Carbon dioxide) dilution is a feasible way for controlling NOx (Nitrogen oxides) emissions and loads of the internal combustion engines. This paper investigated the effect of CO_2 dilution on the combustion and emissions characteristics of a hydrogen-enriched gasoline engine. The experiment was conducted on a 1.6 L spark-ignition engine with electronically controlled hydrogen and gasoline injection systems. At two hydrogen volume fractions of 0 and 3%, the CO_2 volume fraction in the intake was gradually increased from 0 to 4%. The fuel-air mixtures were kept at the stoichiometric. The experimental results demonstrated that brake mean effective pressure of the gasoline engine was quickly reduced after adopting CO_2 dilution. Comparatively, Bmep (Brake mean effective pressure) of the 3% hydrogen-enriched engine was gently decreased with the increase of CO_2 dilution level. Thermal efficiency of the 3% hydrogen-enriched gasoline engine was raised under properly increased CO_2 dilution levels. However, thermal efficiency of the pure gasoline engine was generally dropped after the CO_2 dilution. The addition of hydrogen could shorten flame development and propagation durations under CO_2 diluent conditions for the gasoline engine. Increasing CO_2 fraction in the intake caused the dropped NOx and raised HC (Hydrocarbon) emissions. Increasing hydrogen fraction in the intake could effectively reduce HC emissions under CO_2 diluent conditions. - Highlights: • CO_2 dilution reduces cooling loss and NOx of H_2-enriched gasoline engines. • H_2-blended gasoline engine gains better efficiency after CO_2 dilution. • CoVimep of H_2-blended gasoline engine is kept at low level after CO_2 addition. • CO_2 dilution has small effect on reducing Bmep of H_2-blended gasoline engine.

  18. NOx emission characteristics in turbulent hydrogen jet flames with coaxial air

    International Nuclear Information System (INIS)

    Moon, Hee Jang; Park, Yang Ho; Yoon, Young Bin

    2009-01-01

    The characteristics of NOx emissions in pure hydrogen nonpremixed jet flames with coaxial air are analyzed numerically for a wide range of coaxial air conditions. Among the models tested in simple nonpremixed jet flame, the one-half power scaling law could be reproduced only by the Model C using the HO 2 /H 2 O 2 reaction, implying the importance of chemical nonequilibrium effect. The flame length is reduced significantly by augmenting coaxial air, and could be represented as a function of the ratio of coaxial air to fuel velocity. Predicted EINOx scaling showed a good concordance with experimental data, and the overall one-half power scaling was observed in coaxial flames with Model C when flame residence time was defined with flame volume instead of a cubic of the flame length. Different level of oxygen mass fraction at the stoichiometric surface was observed as coaxial air was increased. These different levels imply that the coaxial air strengthens the nonequilibrium effect

  19. Estimation of effect of hydrogen on the parameters of magnetoacoustic emission signals

    Science.gov (United States)

    Skalskyi, Valentyn; Stankevych, Olena; Dubytskyi, Olexandr

    2018-05-01

    The features of the magnetoacoustic emission (MAE) signals during magnetization of structural steels with the different degree of hydrogenating were investigated by the wavelet transform. The dominant frequency ranges of MAE signals for the different magnetic field strength were determined using Discrete Wavelet Transform (DWT), and the energy and spectral parameters of MAE signals were determined using Continuous Wavelet Transform (CWT). The characteristic differences of the local maximums of signals according to energy, bandwidth, duration and frequency were found. The methodology of estimation of state of local degradation of materials by parameters of wavelet transform of MAE signals was proposed. This methodology was approbated for investigate of state of long-time exploitations structural steels of oil and gas pipelines.

  20. Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel

    Science.gov (United States)

    Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

    2012-11-20

    A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

  1. Dimeric Self-assembling via Hydrogen Bonding and Emissive Behavior of a New Copper (I Complex

    Directory of Open Access Journals (Sweden)

    Juciely M. dos Reis

    2017-04-01

    Full Text Available This work describes the synthesis, structural characterization and emissive behavior of a new copper (I complex based on 1-thiocarbamoyl-5-(4-methoxiphenyl-3-phenyl-4,5-dihydro-1H-pyrazole ligand. A dimeric self-assembling via hydrogen bonding was determined by analyzing the short contacts present in the solid-state structure by means of X-ray crystallography. The spectroscopic properties were determined using UV-Vis and fluorescence experiments and an interesting behavior as bluish luminescence was assigned mainly to the mixed (MLCT + IL electronic transitions of the Cu(Id10 ® (S=C–Nligand type. The complete characterization of the new copper (I complex also included elemental analyses and IR spectroscopy. DOI: http://dx.doi.org/10.17807/orbital.v9i1.952

  2. Noncondensable hydrogen sulfide incineration with brine scrubbing air emissions control system

    International Nuclear Information System (INIS)

    Goddard, W.B.; Goddard, C.B.; McClain, D.W.

    1990-01-01

    This paper reports on the technical and institutional feasibility of incinerating hydrogen sulfide (H2S) contained in geothermal noncondensable gases, and the use of geothermal brine for sulfur dioxide scrubbing and absorption as an Air Emissions Control System (AECS), for geothermal power plant, that have been documented through engineering analysis in the Phase I grant study funded through the California Department of Health Services (DOHS), Hazardous Materials Reduction Grant Program and hosted by California Energy Company (CECI). Grant funding for Phase II now has been approved to proceed with the project through the pilot plant design phase. This innovative AECS does not necessitate the use of hazardous materials or produce hazardous wastes. Cost savings were documented compared to injection pump operation or conventional AECS without the use of hazardous materials. The phase II project is to design, improve, research and develop a source reduction demonstration pilot plant geothermal noncondensable H2S incineration AECS

  3. Exergoeconomic estimates for a novel zero-emission process generating hydrogen and electric power

    International Nuclear Information System (INIS)

    Tsatsaronis, George; Kapanke, Kerstin; Maria Blanco Marigorta, Ana

    2008-01-01

    This paper presents the exergoeconomic analysis of a novel process generating electric energy and hydrogen. Coal and high-temperature heat are used as input energy to the process. The process is a true 'zero-emission process' because (a) no NO X is formed during coal combustion with sulfuric acid, and (b) the combustion products CO 2 and SO 2 are removed separately as compressed liquids from the overall process. The process cycle is based on two chemical reactions. The first reaction takes place in an electrolytic cell and delivers the hydrogen product. In the second step, coal reacts with sulfuric acid in a high-pressure combustion reactor. The combustion gas is expanded in a gas turbine to produce electric power. The combustion products are compressed and separated so that almost pure CO 2 can be removed from the cycle. The overall process is characterized by very high energetic and exergetic efficiencies. However, the overall process is very capital intensive. The electrolytic cell dominates the costs associated with the overall process. Detailed results of the thermodynamic simulation, the economic and the exergoeconomic analyses of the process including estimates of the product costs are presented

  4. 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.

  5. An Experimental Investigation on Performance and Emissions of a Single Cylinder D.I Diesel Engine with Manifold Hydrogen Induction

    Directory of Open Access Journals (Sweden)

    Haroun A.K. Shahad

    2017-05-01

    Full Text Available Hydrogen is a clean fuel for internal combustion engines as it produces only water vapor and nitrogen oxides when it burns. In this research, hydrogen is used as a blending fuel with diesel to reduce pollutants emission and to improve performance. It is inducted in the inlet manifold, (continuous manifold induction, which is of a single cylinder, four stroke, direct injection, variable compression ratio water cold diesel engine, type (Kirloskar. This technique of hydrogen blending is selected because of its simplicity and low cost. Hydrogen blending is built on the basis of energy replacement. A special electronic unit is designed and fabricated to control hydrogen blending ratio. The maximum achieved ratio is 30% of input energy and beyond that the engine operation becomes unsatisfactory. Tests are done with 17.5 compression ratio and 1500 rpm. The brake specific fuel consumption is reduced by 29% and the engine thermal efficiency increased by 16% at these operating conditions. The pollutant emissions of carbon oxides, UHC, and smoke opacity are dramatically decreased by 19.5%, 13%,and 45% respectively while NOx emission increased by 10%.

  6. A study of diesel-hydrogen fuel exhaust emissions in a compression ignition engine/generator assembly

    International Nuclear Information System (INIS)

    Karri, V.; Hafez, H.A.; Kirkegaard, J.F.

    2006-01-01

    A compression engine and duel-fuel supply system was studied in order to determine the influence of hydrogen gas on a diesel engine's exhaust system. Commercially available solenoid valves and pulse actuators were used in a customized mechatronic control unit (MICU) to inject the hydrogen gas into the cylinders during the experiments. The MICU was designed as a generic external attachment. Diesel fuel was used to ignite the hydrogen gas-air mixture after compression. Various different electrical loads were then applied using an alternator in order to stimulate the engine governor and control diesel flow. Results of the study showed that measured carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NO x ) loads of exhaust emissions increased, while emissions of carbon dioxide (CO 2 ) decreased. Results also showed that higher temperatures and levels of NO x occurred when hydrogen was mixed with the induced air. It was concluded that higher levels of hydrogen may be needed to reduce emissions. 17 refs., 5 tabs., 2 figs

  7. Road vehicle emissions of molecular hydrogen (H 2) from a tunnel study

    Science.gov (United States)

    Vollmer, Martin K.; Juergens, Niklas; Steinbacher, Martin; Reimann, Stefan; Weilenmann, Martin; Buchmann, Brigitte

    Motor vehicle combustion emissions of molecular hydrogen (H 2), carbon monoxide (CO), and carbon dioxide (CO 2) were measured during a 6-week period from November 2004 to January 2005 in Gubrist Tunnel, Switzerland, to determine vehicle emission factors for these trace gases and the ratios of the concentration growths ΔH2/ΔCO and ΔH2/ΔCO2 in the tunnel under real-world highway driving conditions. For H 2, molar mixing ratios at the tunnel exit were found to be 7-10 ppm (parts-per-million, 10-6) during rush hours. Mean emission factors of E=49.7(±16.5)mgkm-1, ECO=1.46(±0.54)gkm-1, and E=266(±69)gkm-1 were calculated. E was largest during weekday rush-hour traffic, a consequence of the more frequent accelerations in congested traffic when fuel combustion is not optimal. E was smaller for heavy-duty vehicles (HDV) compared to light-duty vehicles (LDV), a finding which was attributed to the diesel vs. gasoline engine technology. The mean ΔH2/ΔCO molecular ratio was 0.48±0.12. This ratio increased to ˜0.6 during rush hours, suggesting that H 2 yield is favored relative to CO under fuel-rich conditions, presumably a consequence of an increasing contribution of the water-gas-shift reaction. The mean ΔH2/ΔCO2 molecular ratio was 4.4×10-3 but reduced to 2.5×10-3 when the relative HDV abundance was at maximum. Using three different approaches, road traffic H 2 emissions were estimated for 2004 for Switzerland at 5.0-6.6 Gg and globally at 4.2-8.1 Tg. Despite projections of increasing traffic, Swiss H 2 emissions are not expected to change significantly in the near future, and global emissions are likely to decrease due to improved exhaust gas clean-up technologies.

  8. Performance and emission study in manifold hydrogen injection with diesel as an ignition source for different start of injection

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, N. [ERC-Engines, TATA Motors Ltd, Pimpri, Pune, Maharashtra 411018 (India); Nagarajan, G. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai, Tamil Nadu 600 025 (India)

    2009-01-15

    Over the past two decades there has been a considerable effort to develop and introduce alternative transportation fuels to replace conventional fuels, gasoline and diesel. Environmental issues are the principal driving forces behind this effort. To date the bulk of research has focused on the carbon-based fuels such as reformulated gasoline, methanol and natural gas. One alternative fuel to carbon-based fuels is hydrogen which is considered to be low polluting fuel. In the present experimental investigation hydrogen was injected into the intake manifold by using an injector. Using an electronic control unit (ECU) the injection timing and the duration were controlled. From the results it is observed that the optimum injection timing is at gas exchange top dead center (GTDC). The efficiency improved by about 15% with an increase in NO{sub X} emission by 3% compared to diesel. The smoke emission decreased by almost 100%. A net reduction in carbon emissions was also noticed due to the use of hydrogen. By adopting manifold injection technique the hydrogen-diesel dual fuel engine operates smoothly with a significant improvement in performance and reduction in emissions. (author)

  9. Borax and Octabor Treatment of Stored Swine Manure: Reduction in Hydrogen Sulfide Emissions and Phytotoxicity to Agronomic Crops

    Science.gov (United States)

    Gaseous emissions from stored manure have become environmental and health issues for humans and animals as the livestock industry becomes specialized and concentrated. Of particular concern is hydrogen sulfide, which is being targeted for regulatory control in concentrated animal farm operations. ...

  10. Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions

    Science.gov (United States)

    Odorous gas emissions from stored swine manure are becoming serious environmental and health issues as the livestock industry becomes more specialized, concentrated, and industrialized. These nuisance gasses include hydrogen sulfide (H2S), ammonia, and methane, which are produced as a result of ana...

  11. Ultralow field emission from thinned, open-ended, and defected carbon nanotubes by using microwave hydrogen plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jian-Hua, E-mail: jhdeng1983@163.com [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Lin; Wang, Fan-Jie; Yu, Bin; Li, Guo-Zheng; Li, De-Jun [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Guo-An [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China)

    2015-01-01

    Graphical abstract: Thinned, open-ended, and defected carbon nanotubes were prepared by using hydrogen plasma processing. The processed carbon nanotubes have far better field emission performance than that of the pristine ones. - Highlights: • CVD prepared CNT arrays were processed by microwave hydrogen plasma. • Thinned, open-ended, and defected CNTs were obtained. • Processed CNTs have far better field emission performance than the pristine ones. • Processed CNTs have applicable emission stability after being perfectly aged. - Abstract: Ultralow field emission is achieved from carbon nanotubes (CNTs) by using microwave hydrogen plasma processing. After the processing, typical capped CNT tips are removed, with thinned, open-ended, and defected CNTs left. Structural analyses indicate that the processed CNTs have more SP{sup 3}-hybridized defects as compared to the pristine ones. The morphology of CNTs can be readily controlled by adjusting microwave powers, which change the shape of CNTs by means of hydrogen plasma etching. Processed CNTs with optimal morphology are found to have an ultralow turn-on field of 0.566 V/μm and threshold field of 0.896 V/μm, much better than 0.948 and 1.559 V/μm of the as-grown CNTs, respectively. This improved FE performance is ascribed to the structural changes of CNTs after the processing. The thinned and open-ended shape of CNTs can facilitate electron tunneling through barriers and additionally, the increased defects at tube walls can serve as new active emission sites. Furthermore, our plasma processed CNTs exhibit excellent field emission stability at a large emission current density of 10.36 mA/cm{sup 2} after being perfectly aged, showing promising prospects in applications as high-performance vacuum electron sources.

  12. New Observations of Balmer Continuum Flux in Solar Flares Instrument Description and First Results

    Czech Academy of Sciences Publication Activity Database

    Kotrč, Pavel; Procházka, O.; Heinzel, Petr

    2016-01-01

    Roč. 291, č. 3 (2016), s. 779-789 ISSN 0038-0938 R&D Projects: GA ČR GAP209/12/1652 Grant - others:EC(XE) 295272; EC(XE) 606862 Program:FP7; FP7 Institutional support: RVO:67985815 Keywords : flares * spectrum * Balmer continuum Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.682, year: 2016

  13. 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.

  14. An experimental investigation of performance-emission trade off characteristics of a CI engine using hydrogen as dual fuel

    International Nuclear Information System (INIS)

    Deb, Madhujit; Paul, Abhishek; Debroy, Durbadal; Sastry, G.R.K.; Panua, Raj Sekhar; Bose, P.K.

    2015-01-01

    The investigation carried out in this research work concerns the effect of the addition of H 2 on performance and emission characteristics of a single cylinder, 4-stroke diesel engine. The tests were performed using diesel as a pilot fuel, with hydrogen addition at varying load condition using a Timed Manifold Injection (TMI) system has been developed using ECU (electronic control unit) with varying injection strategy to deliver hydrogen on to the intake manifold. The results showed a significant increase in BTE with appreciable decrease in BSEC of the engine when compared to conventional diesel-fueled operation. The emission of CO 2 and NOx was found to increase with enhancement of H 2 addition. The emission of UHC was found to be very high at low load conditions, but it enhanced as the load increased for all hydrogen injection while Soot emissions decreased. Thus, this paper provided a potential to investigate the effect of the addition of H 2 on the performance and emission characteristics of a diesel engine and how to get a best ratio of H 2 addition. The tradeoff study also consolidated the verity that Diesel–H 2 dual fuel operation was instrumental in resolving the high performance – low emission paradox. - Highlights: • Pure diesel and diesel–H 2 blends are tested. • Diesel–H 2 blends produced higher brake thermal efficiency than pure diesel in all part loads. • Diesel–H 2 blends reduced the energy consumption of the engine. • Diesel–H 2 blends simultaneously reduced Soot to some extent but increases N Ox and hydrocarbon emissions. • The performance-emission trade-off paradox has been studied using pure diesel and diesel–H 2 blends

  15. An Anomaly in the Inglis-Teller Limits of the C VI Lyman and Balmer Series in Laser-Produced Plasmas

    Science.gov (United States)

    Elton, R.; Iglesias, E.; Griem, H.; Weaver, J.; Pien, G.; Mancini, R.

    2002-11-01

    Soft x-ray spectra from thin carbon layers heated by the OMEGA and NIKE lasers have been obtained with both spherical and planar targets, respectively, using a flat-field grazing incidence spectrograph equipped with a gated microchannel plate for temporal resolution. In both experiments, late-time (recombining) hydrogenic C VI spectra show an n-to-1 Lyman spectral series blending with the continuum at n=4, contrary to n=9 in the n-to-2 Balmer series. It appears unlikely that plasma inhomogeneities are the sole cause of this anomaly, given the difference in the experimental configurations. Other explanations for the line-to-continuum merging (other than the usual Stark-broadened Inglis-Teller effect) under consideration include non-thermal Doppler broadening, deviations from statistical sublevel population distributions, and opacity effects. Collisional-radiative and hydrodynamic modeling, including cascades, is employed to further understand this phenomenon.

  16. Dissociative Excitation of Acetylene Induced by Electron Impact: Excitation-emission Cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Országh, Juraj; Danko, Marián; Čechvala, Peter; Matejčík, Štefan, E-mail: matejcik@fmph.uniba.sk [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F-2, 842 48 Bratislava (Slovakia)

    2017-05-20

    The optical emission spectrum of acetylene excited by monoenergetic electrons was studied in the range of 190–660 nm. The dissociative excitation and dissociative ionization associated with excitation of the ions initiated by electron impact were dominant processes contributing to the spectrum. The spectrum was dominated by the atomic lines (hydrogen Balmer series, carbon) and molecular bands (CH(A–X), CH(B–X), CH{sup +}(B–A), and C{sub 2}). Besides the discrete transitions, we have detected the continuum emission radiation of ethynyl radical C{sub 2}H(A–X). For most important lines and bands of the spectrum we have measured absolute excitation-emission cross sections and determined the energy thresholds of the particular dissociative channels.

  17. Autothermal catalytic pyrolysis of methane as a new route to hydrogen production with reduced CO{sub 2} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Smith, Franklyn; Huang, Cunping; T-Raissi, Ali [Florida Solar Energy Center, University of Central Florida, Cocoa, FL 32922 (United States)

    2006-08-15

    Hydrogen production plants are among major sources of CO{sub 2} emissions into the atmosphere. The objective of this paper is to explore new routes to hydrogen production from natural gas (or methane) with drastically reduced CO{sub 2} emissions. One approach analyzed in this paper is based on thermocatalytic decomposition (or pyrolysis) of methane into hydrogen gas and elemental carbon over carbon-based catalysts. Several heat input options to the endothermic process are discussed in the paper. The authors conduct thermodynamic analysis of methane decomposition in the presence of small amounts of oxygen in an autothermal (or thermo-neutral) regime using AspenPlus(TM) chemical process simulator. Methane conversion, products yield, effluent gas composition, process enthalpy flows as a function of temperature, pressure and O{sub 2}/CH{sub 4} ratio has been determined. CO{sub 2} emissions (per m{sup 3} of H{sub 2} produced) from the process could potentially be a factor of 3-5 less than from conventional hydrogen production processes. Oxygen-assisted decomposition of methane over activated carbon (AC) and AC-supported iron catalysts over wide range of temperatures and O{sub 2}/CH{sub 4} ratios was experimentally verified. Problems associated with the catalyst deactivation and the effect of iron doping on the catalyst stability are discussed. (author)

  18. Kinetic energy measurement of hydrogen in LHD peripheral plasma with a multi-wavelength-range fine-resolution spectrometer

    International Nuclear Information System (INIS)

    Fujii, Keisuke; Mizushiri, Keisuke; Nishioka, Tomomi; Shikama, Taiichi; Iwamae, Atsushi; Goto, Motoshi; Morita, Shigeru; Hasuo, Masahiro

    2010-01-01

    We have simultaneously measured high resolution emission spectra of the hydrogen atomic Balmer-α, -β, -γ lines and molecular Fulcher-α band for a LHD peripheral plasma generated under a central magnetic field strength of 0.4 T. It is found that the velocity distributions of excited atoms calculated from the Balmer-α, -β, and -γ line shapes show similar profiles to each other. The translational kinetic energy corresponding to the average velocity is about 13 eV, which is about 300 times larger than the rotational energy of hydrogen molecules estimated from the line intensities in the Fulcher-α band. The velocity distributions differ from Maxwellian and have a high velocity tail over 1x10 5 m/s. A correlation between the high velocity tail and the electron temperature and density is seen and suggesting the excited atoms having such high velocities to be generated by the charge exchange collisions from high velocity protons in the peripheral region.

  19. Enhancing Hydrogen Diffusion in Silica Matrix by Using Metal Ion Implantation to Improve the Emission Properties of Silicon Nanocrystals

    Directory of Open Access Journals (Sweden)

    J. Bornacelli

    2014-01-01

    Full Text Available Efficient silicon-based light emitters continue to be a challenge. A great effort has been made in photonics to modify silicon in order to enhance its light emission properties. In this aspect silicon nanocrystals (Si-NCs have become the main building block of silicon photonic (modulators, waveguide, source, and detectors. In this work, we present an approach based on implantation of Ag (or Au ions and a proper thermal annealing in order to improve the photoluminescence (PL emission of Si-NCs embedded in SiO2. The Si-NCs are obtained by ion implantation at MeV energy and nucleated at high depth into the silica matrix (1-2 μm under surface. Once Si-NCs are formed inside the SiO2 we implant metal ions at energies that do not damage the Si-NCs. We have observed by, PL and time-resolved PL, that ion metal implantation and a subsequent thermal annealing in a hydrogen-containing atmosphere could significantly increase the emission properties of Si-NCs. Elastic Recoil Detection measurements show that the samples with an enhanced luminescence emission present a higher hydrogen concentration. This suggests that ion metal implantation enhances the hydrogen diffusion into silica matrix allowing a better passivation of surface defects on Si NCs.

  20. ON THE EARLY-TIME EXCESS EMISSION IN HYDROGEN-POOR SUPERLUMINOUS SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Vreeswijk, Paul M.; Leloudas, Giorgos; Gal-Yam, Avishay; De Cia, Annalisa; Waldman, Roni; Ofek, Eran O.; Yaron, Ofer [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Perley, Daniel A. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 København Ø (Denmark); Quimby, Robert M. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Yan, Lin [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Fremling, Christoffer; Taddia, Francesco; Sollerman, Jesper [The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-10691 Stockholm (Sweden); Valenti, Stefano [Department of Physics, University of California, Davis, CA 95616 (United States); Arcavi, Iair; Howell, D. Andrew [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kasliwal, Mansi M., E-mail: paul.vreeswijk@weizmann.ac.il [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); and others

    2017-01-20

    We present the light curves of the hydrogen-poor superluminous supernovae (SLSNe I) PTF 12dam and iPTF 13dcc, discovered by the (intermediate) Palomar Transient Factory. Both show excess emission at early times and a slowly declining light curve at late times. The early bump in PTF 12dam is very similar in duration (∼10 days) and brightness relative to the main peak (2–3 mag fainter) compared to that observed in other SLSNe I. In contrast, the long-duration (>30 days) early excess emission in iPTF 13dcc, whose brightness competes with that of the main peak, appears to be of a different nature. We construct bolometric light curves for both targets, and fit a variety of light-curve models to both the early bump and main peak in an attempt to understand the nature of these explosions. Even though the slope of the late-time decline in the light curves of both SLSNe is suggestively close to that expected from the radioactive decay of {sup 56}Ni and {sup 56}Co, the amount of nickel required to power the full light curves is too large considering the estimated ejecta mass. The magnetar model including an increasing escape fraction provides a reasonable description of the PTF 12dam observations. However, neither the basic nor the double-peaked magnetar model is capable of reproducing the light curve of iPTF 13dcc. A model combining a shock breakout in an extended envelope with late-time magnetar energy injection provides a reasonable fit to the iPTF 13dcc observations. Finally, we find that the light curves of both PTF 12dam and iPTF 13dcc can be adequately fit with the model involving interaction with the circumstellar medium.

  1. Plasma parameter diagnosis using hydrogen emission spectra of a quartz-chamber 2.45 GHz ECRIS at Peking University

    Science.gov (United States)

    Wu, WenBin; Ren, HaiTao; Peng, ShiXiang; Xu, Yuan; Wen, JiaMei; Zhang, Tao; Zhang, JingFeng; Zhang, AiLin; Sun, Jiang; Guo, ZhiYu; Chen, JiaEr

    2018-04-01

    A quartz-chamber 2.45 GHz electron cyclotron resonance ion source (ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 mA hydrogen ion beam at 50 kV with a duty factor of 10%. The root-mean-square (RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work, the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10-4 to 1×10-3 Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results.

  2. NOx emission characteristics in turbulent hydrogen jet flames with coaxial air

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Hee Jang [Korea Aerospace University, Goyang (Korea, Republic of); Park, Yang Ho; Yoon, Young Bin [Seoul National University, Seoul (Korea, Republic of)

    2009-06-15

    The characteristics of NOx emissions in pure hydrogen nonpremixed jet flames with coaxial air are analyzed numerically for a wide range of coaxial air conditions. Among the models tested in simple nonpremixed jet flame, the one-half power scaling law could be reproduced only by the Model C using the HO{sub 2}/H{sub 2}O{sub 2} reaction, implying the importance of chemical nonequilibrium effect. The flame length is reduced significantly by augmenting coaxial air, and could be represented as a function of the ratio of coaxial air to fuel velocity. Predicted EINOx scaling showed a good concordance with experimental data, and the overall one-half power scaling was observed in coaxial flames with Model C when flame residence time was defined with flame volume instead of a cubic of the flame length. Different level of oxygen mass fraction at the stoichiometric surface was observed as coaxial air was increased. These different levels imply that the coaxial air strengthens the nonequilibrium effect

  3. Fine structure of the stimulated Raman spectrum in compressed hydrogen. The relaxation-oscillation mode of backscattered Stokes emission

    International Nuclear Information System (INIS)

    Bespalov, V.G.; Efimov, Yu.N.; Staselko, D.I.

    1992-01-01

    This paper studies the emission spectra of backscattered stimulated Raman scattering (SRS) in compressed hydrogen in the relaxation-oscillation mode and the compression SRS mode for the minimum width of the spontaneous scattering spectrum (in the region of the Dicke dip). It is shown that the generation of a train of Stokes-emission subpulses results in the appearance of fine structure in the backscattered SRS spectrum. The influence of the temporal structure of reflected Stokes pulses on this spectrum and on the appearance of fine structure in it is analyzed. The conditions for generating spectrally limited (without phase modulation), extremely coherent Stokes pulses are explained. 18 refs., 3 figs

  4. Narrowband Hα Imaging of Old Hydrogen-deficient Supernovae

    Science.gov (United States)

    Pooley, David A.; Vinko, Jozsef; Silverman, Jeffrey M.; Wheeler, J. Craig Craig; Szalai, Tamas; MacQueen, Phillip; Marion, Howie H.; Sárneczky, Krisztián

    2017-06-01

    We report results from our long-term observational survey aimed at discovering late-time interaction between the ejecta of hydrogen-deficient Type I supernovae and the hydrogen-rich envelope expelled from the progenitor star several decades to centuries before explosion. The expelled envelope, moving with a velocity of ˜10-100 km/s, is expected to be caught up by the fast-moving SN ejecta several years to decades after explosion depending on the history of the mass-loss process acting in the progenitor star prior to explosion. The collision between the SN ejecta and the circumstellar envelope results in net emission in the Balmer-lines, especially in Hα. For the past three years, we have been using the Direct Imaging Auxiliary Functions Instrument (DIAFI) on the 2.7m Harlan J. Smith Telescope at McDonald Observatory to look for signs of late-time Hα emission in older Type Ia/Ibc/IIb SNe having hydrogen-poor ejecta, via narrow-band imaging. Continuum-subtracted Hα emission has been detected for 13 point sources: 9 SN Ibc, 1 SN IIb and 3 SN Ia events. Thirty-eight SN sites were observed on at least two epochs, from which three objects (SN 1985F, SN 2005kl, SN 2012fh) showed significant temporal variation in the strength of their Hα emission in our DIAFI data. This suggests that the variable emission is probably not due to nearby HII regions, and hence is an important additional hint that ejecta-CSM interaction may take place in these systems. Moreover, we successfully detected the late-time Hα emission from the Type Ib SN 2014C, which was recently discovered as a strongly interacting SN in other wavebands.

  5. Life Cycle Greenhouse Gas Emissions of By-product Hydrogen from Chlor-Alkali Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Yeon [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division; Elgowainy, Amgad A. [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division; Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division

    2017-12-01

    Current hydrogen production capacity in the U.S. is about 15.8 million tonne (or metric ton) per year (Brown 2016). Some of the hydrogen (2 million tonne) is combusted for its heating energy value, which makes total annual net production 13.8 million tonne (Table 1). If captive by-product hydrogen (3.3 million tonne) from catalytic reforming at oil refineries is excluded (Brown 2016; EIA 2008), approximately 11 million tonne is available from the conventional captive and merchant hydrogen market (DOE 2013). Captive hydrogen (owned by the refiner) is produced and consumed on site (e.g., process input at refineries), whereas merchant hydrogen is produced and sold as a commodity to external consumers. Whether it is merchant or captive, most hydrogen produced in the U.S. is on-purpose (not by-product)— around 10 million tonne/year.

  6. Data on trapping and re-emission of energetic hydrogen isotopes and helium in materials, supplement 1

    International Nuclear Information System (INIS)

    Yamaguchi, Sadae; Sugizaki, Yasuaki; Ozawa, Kunio; Nakai, Yohta.

    1984-05-01

    This is the supplement to the data on trapping and re-emission of energetic hydrogen isotopes and helium in materials (JAERI-M 82-118). It contains 32 data up to end of 1982, dividing it into following 6 sections: 1) Dose Dependence, 2) Target Material Dependence, 3) Target Temperature Dependence, 4) Incident Energy Dependence, 5) Damage Effects and 6) Ion-Induced Release. (author)

  7. Experimental investigation of the effects of simultaneous hydrogen and nitrogen addition on the emissions and combustion of a diesel engine

    OpenAIRE

    Megaritis, A

    2014-01-01

    This article is made available through the Brunel Open Access Publishing Fund. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright @ 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Overcoming diesel engine emissions t...

  8. Near ultraviolet spectra of a group of early-type stars with Balmer emission

    International Nuclear Information System (INIS)

    Ringuelet, A.E.

    1980-01-01

    In the near ultraviolet region some absorption features in B stars are easily recognizable as criteria for assigning luminosity class. In the same region the characteristics displayed by Be stars suggest higher luminosities than in the photographic region. It appears that Fe II 2538-2548 A should be useful for studying the outer layers of stellar atmospheres. (author)

  9. Near ultraviolet spectra of a group of early-type stars with Balmer emission

    Energy Technology Data Exchange (ETDEWEB)

    Ringuelet, A E [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)

    1980-08-01

    In the near ultraviolet region some absorption features in B stars are easily recognizable as criteria for assigning luminosity class. In the same region the characteristics displayed by Be stars suggest higher luminosities than in the photographic region. It appears that Fe II 2538-2548 A should be useful for studying the outer layers of stellar atmospheres.

  10. Investigation of low-latitude hydrogen emission in terms of a two-component interstellar gas model

    International Nuclear Information System (INIS)

    Baker, P.L.; Burton, W.B.

    1975-01-01

    The high-resolution 21-cm hydrogen line observations at low galactic latitude of Burton and Verschuur have been analyzed to determine the large-scale distribution of galactic hydrogen. The distribution parameters are found by model fitting. Optical depth affects have been computed using a two-component gas model. Analysis shows that a multiphase description of the medium is essential to the interpretation of low-latitude emission observations. Where possible, the number of free parameters in the gas model has been reduced. Calculations were performed for a one-component, uniform spin temperature, gas model in order to show the systematic departures between this model and the data caused by the incorrect treatment of the optical depth effect. In the two-component gas, radiative transfer is treated by a Monte Carlo calculation since the opacity of the gas arises in a randomly distributed, cold, optically thick, low velocity-dispersion, cloud medium. The emission arises in both the cloud medium and a smoothly distributed, optically thin, high velocity-dispersion, intercloud medium. The synthetic profiles computed from the two-component model reproduce both the large-scale trends of the observed emission profiles and the magnitude of the small-scale emission irregularities. The analysis permits the determination of values for []he thickness of the galactic disk between half density points, the total observed neutral hydrogen mass of the Galaxy, and the central number density of the intercloud atoms. In addition, the analysis is sensitive to the size of clouds contributing to the observations. Computations also show that synthetic emission profiles based on the two-component model display both the zero-velocity and high-velocity ridges, indicative of optical thinness on a large scale, in spite of the presence of optically thick gas

  11. PTF11kx: A Type Ia Supernova with Hydrogen Emission Persisting after 3.5 Years

    Energy Technology Data Exchange (ETDEWEB)

    Graham, M. L. [Department of Astronomy, University of Washington, Box 351580, U.W., Seattle, WA 98195-1580 (United States); Harris, C. E.; Nugent, P. E.; Kasen, D.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Fox, O. D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States)

    2017-07-10

    The optical transient PTF11kx exhibited both the characteristic spectral features of Type Ia supernovae (SNe Ia) and the signature of ejecta interacting with circumstellar material (CSM) containing hydrogen, indicating the presence of a nondegenerate companion. We present an optical spectrum at 1342 days after peak from Keck Observatory, in which the broad component of H α emission persists with a similar profile as in early-time observations. We also present Spitzer IRAC detections obtained 1237 and 1818 days after peak, and an upper limit from Hubble Space Telescope ultraviolet imaging at 2133 days. We interpret our late-time observations in the context of published results—and reinterpret the early-time observations—in order to constrain the CSM’s physical parameters and to compare to theoretical predictions for recurrent-nova systems. We find that the CSM’s radial extent may be several times the distance between the star and the CSM’s inner edge, and that the CSM column density may be two orders of magnitude lower than previous estimates. We show that the H α luminosity decline is similar to other SNe with CSM interaction and demonstrate how our infrared photometry is evidence for newly formed, collisionally heated dust. We create a model for PTF11kx’s late-time CSM interaction and find that X-ray reprocessing by photoionization and recombination cannot reproduce the observed H α luminosity, suggesting that the X-rays are thermalized and that H α radiates from collisional excitation. Finally, we discuss the implications of our results regarding the progenitor scenario and the geometric properties of the CSM for the PTF11kx system.

  12. INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

    OpenAIRE

    Alfredas Rimkus; Mindaugas Melaika; Jonas Matijošius; Šarūnas Mikaliūnas; Saugirdas Pukalskas

    2016-01-01

    In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume) gasoline mixtures and additionally supplied oxygen and hydrogen (HHO) gas mixture (3.6 l/min) in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during comb...

  13. Hydrogen energy share improvement along with NOx (oxides of nitrogen) emission reduction in a hydrogen dual-fuel compression ignition engine using water injection

    International Nuclear Information System (INIS)

    Chintala, V.; Subramanian, K.A.

    2014-01-01

    Highlights: • H 2 energy share increased from 20% without water to 39% with SWC 270 g/kWh. • Specific water consumption (SWC) 200 g/kWh was selected as the optimum quantity. • NO x decreased about 24% with the optimum water quantity at 20% H 2 energy share. • At 20% H 2 share, energy efficiency decreased about 5.5% with the optimum water. • HC, CO and smoke emissions increased 38%, 100% and 69% with optimum water at 20% H 2 share. - Abstract: The study aims at enhancement of Hydrogen (H 2 ) energy share and reduction of Oxides of Nitrogen (NO x ) emission in a 7.4 kW-CI engine at 1500 rpm using water injection. The test engine was modified to run under dual-fuel operation with diesel–biodiesel blend (B20) and H 2 fuels for different Specific Water Consumption (SWC) of 130, 200, and 270 g/kWh. Under conventional H 2 dual-fuel mode, energy efficiency and NO x emission increased significantly while Hydrocarbon (HC), Carbon Monoxide (CO) and smoke emissions decreased. The maximum H 2 energy share increased from 20% without water to 32%, 36%, and 39% with SWC of 130, 200, and 270 g/kWh respectively. However, SWC of 200 g/kWh was selected as an optimum water quantity for knock free operation, better performance and lower emissions. At the optimum SWC with 20% H 2 energy share, the NO x emission and energy efficiency decreased about 24% and 5.7%, while HC and smoke emissions increased about 38% and 69%. At 20% H 2 energy share, the CO emission increased from 0.0 g/kWh without water to 1.2 g/kWh with the optimum SWC. However, reduction of these HC and CO emissions using oxidation catalysts needs to be studied further. A new methodology for determining heat release rate with consideration of crevice gas was proposed in the study

  14. Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

    Science.gov (United States)

    Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

    2004-01-01

    This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

  15. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experimental Spherical Torus

    Energy Technology Data Exchange (ETDEWEB)

    Kim, YooSung; Shi, Yue-Jiang, E-mail: yjshi@snu.ac.kr; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Chung, Kyoung-Jae [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Oh, Soo-Ghee [Division of Energy Systems Research, Ajou University, Suwon 442-749 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advanced Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2016-11-15

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of H{sub α} and H{sub β} radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  16. Performance and emission comparison of a supercharged dual-fuel engine fueled by producer gases with varying hydrogen content

    Energy Technology Data Exchange (ETDEWEB)

    Mohon Roy, Murari [Rajshahi University of Engineering and Technology (JSPS Research Fellow, Okayama University), Tsushima-Naka 3, Okayama 700-8530 (Japan); Department of Mechanical Engineering, Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Tomita, Eiji; Kawahara, Nobuyuki; Harada, Yuji [Department of Mechanical Engineering, Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Sakane, Atsushi (Mitsui Engineering and Shipbuilding Co. Ltd., 6-4 Tsukiji 5-chome, Chuo-ku, Tokyo)

    2009-09-15

    This study investigated the effect of hydrogen content in producer gas on the performance and exhaust emissions of a supercharged producer gas-diesel dual-fuel engine. Two types of producer gases were used in this study, one with low hydrogen content (H{sub 2} = 13.7%) and the other with high hydrogen content (H{sub 2} = 20%). The engine was tested for use as a co-generation engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant injection pressure and injection quantity for different fuel-air equivalence ratios and at various injection timings. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion. Better combustion, engine performance, and exhaust emissions (except NO{sub x}) were obtained with the high H{sub 2}-content producer gas than with the low H{sub 2}-content producer gas, especially under leaner conditions. Moreover, a broader window of fuel-air equivalence ratio was found with highest thermal efficiencies for the high H{sub 2}-content producer gas. (author)

  17. The spatial distribution and velocity field of the molecular hydrogen line emission from the centre of the Galaxy

    International Nuclear Information System (INIS)

    Gatley, I.; Krisciunas, K.; Jones, T.J.; Hyland, A.R.; Geballe, T.R.; Rijksuniversiteit Groningen

    1986-01-01

    In an earlier paper the existence of a ring of molecular hydrogen-line emission surrounding the nucleus of the Galaxy was demonstrated. Here are presented the first detailed maps of the surface brightness and the velocity field, made in the upsilon=1-0 S(1) line of molecular hydrogen with a spatial resolution of 18 arcsec and a velocity resolution of 130 km s -1 . It is found that the molecular ring is tilted approximately 20 0 out of the plane of the Galaxy, has a broken and clumpy appearance, rotates at 100 km s -1 in the sense of galactic rotation, and exhibits radial motion at a velocity of 50 km s -1 . (author)

  18. Simulation and Empirical Studies of the Commercial SI Engine Performance and Its Emission Levels When Running on a CNG and Hydrogen Blend

    Directory of Open Access Journals (Sweden)

    Rafaa Saaidia

    2017-12-01

    Full Text Available This article is a report on a simulation based on Computational Fluid Dynamics (CFD and an empirical investigation of in-cylinder flow characteristics, In addition, it assesses the performance and emission levels of a commercial-spark ignited engine running on a CNG and Hydrogen blend in different ratios. The main objective was to determine the optimum hydrogen ratio that would yield the best brake torque and release the least polluting gases. The in-cylinder flow velocity and turbulence aspects were investigated during the intake stroke in order to analyze the intake flow behavior. To reach this goal, a 3D CFD code was adopted. For various engine speeds were investigated for gasoline, CNG and hydrogen and CNG blend (HCNG fueled engines via external mixtures. The variation of brake torque (BT, NOX and CO emissions. A series of tests were conducted on the engine within the speed range of 1000 to 5000 rpm. For this purpose, a commercial Hyundai Sonata S.I engine was modified to operate with a blend of CNG and Hydrogen in different ratios. The experiments attempted to determine the optimum allowable hydrogen ratio with CNG for normal engine operation. The engine performance and the emission levels were also analyzed. At the engine speed of 4200 rpm, the results revealed that beyond a ratio of 50% of the volume of hydrogen added to CNG a backfire phenomenon appeared. Below this ratio (0~40% of the hydrogen volume, the CNG and Hydrogen blend seemed to be beneficial for the engine performance and for curtailing the emission level. However, at low engine speeds, the NOX concentration increased simultaneously with hydrogen content. In contrast, at high engine speeds, the NOX concentration decreased to its lowest level compared to that reached with gasoline as a running fuel. The concentration levels of HC, CO2, and CO decreased with the increase of hydrogen percentage.

  19. Emission of hydrogen sulfide (H2S) at a waterfall in a sewer: study of main factors affecting H2S emission and modeling approaches.

    Science.gov (United States)

    Jung, Daniel; Hatrait, Laetitia; Gouello, Julien; Ponthieux, Arnaud; Parez, Vincent; Renner, Christophe

    2017-11-01

    Hydrogen sulfide (H 2 S) represents one of the main odorant gases emitted from sewer networks. A mathematical model can be a fast and low-cost tool for estimating its emission. This study investigates two approaches to modeling H 2 S gas transfer at a waterfall in a discharge manhole. The first approach is based on an adaptation of oxygen models for H 2 S emission at a waterfall and the second consists of a new model. An experimental set-up and a statistical data analysis allowed the main factors affecting H 2 S emission to be studied. A new model of the emission kinetics was developed using linear regression and taking into account H 2 S liquid concentration, waterfall height and fluid velocity at the outlet pipe of a rising main. Its prediction interval was estimated by the residual standard deviation (15.6%) up to a rate of 2.3 g H 2 S·h -1 . Finally, data coming from four sampling campaigns on sewer networks were used to perform simulations and compare predictions of all developed models.

  20. Estimation of the molecular hydrogen soil uptake and traffic emissions at a suburban site near Paris through hydrogen, carbon monoxide, and radon-222 semicontinuous measurements

    International Nuclear Information System (INIS)

    Yver, C.; Schmidt, M.; Bousquet, P.; Ramonet, M.; Bousquet, P.; Zahorowski, W.

    2009-01-01

    Since June 2006, simultaneous semicontinuous measurements of tropospheric molecular hydrogen (H 2 ), carbon monoxide (CO), and radon-222 ( 222 Rn) have been performed at Gif-sur-Yvette (Paris region), a suburban atmospheric measurement site in France. Molecular hydrogen mixing ratios range from 500 to 1000 ppb, CO mixing ratios vary from 100 to 1400 ppb, and 222 Rn concentrations fluctuate from 0 to 20 Bq m -3 . The H 2 seasonal cycle shows the expected pattern for the Northern Hemisphere with a maximum in spring and a minimum in autumn. We inferred a mean baseline value of 533 ppb with a peak-to-peak amplitude of 30 ppb. Carbon monoxide exhibits a seasonal cycle with a maximum in winter and a minimum in summer. The mean baseline value reaches 132 ppb with a peak-to-peak amplitude of 40 ppb. Radon-222 presents weak seasonal variations with a maximum in autumn/winter and a minimum in spring/summer. The diurnal cycles of H 2 and CO are dominated by emissions from nearby traffic with two peaks during morning and evening rush hours. The typical H 2 /CO emission ratio from traffic is found to be 0.47 ± 0.08 on a molar basis (ppb/ppb). The radon tracer method is applied to nighttime H 2 observations to estimate the H 2 soil uptake of the nocturnal catchment area of our sampling site. The influences from nocturnal local anthropogenic combustion sources are estimated by parallel measurements of CO at 0.14 * 10 -5 g(H 2 ) m -2 h -1 . The mean inferred dry deposition velocity is 0.024 ± 0.013 cm s -1 with a seasonal amplitude of 40% at Gif-sur-Yvette.

  1. Surface and electron emission properties of hydrogen-free diamond-like carbon films investigated by atomic force microscopy

    International Nuclear Information System (INIS)

    Liu Dongping; Zhang, Sam; Ong, S.-E.; Benstetter, Guenther; Du Hejun

    2006-01-01

    In this study, we have deposited hydrogen-free diamond-like carbon (DLC) films by using DC magnetron sputtering of graphite target at various r.f. bias voltages. Surface and nanoscale emission properties of these DLC films have been investigated using a combination of atomic force microscopy (AFM)-based nanowear tests and conducting-AFM, by simultaneously measuring the topography and the conductivity of the samples. Nanowear tests show that these DLC films are covered with the thin (1.5-2.0 nm) graphite-like layers at surfaces. Compared to the film bulk structure, the graphite-like surface layers are more conductive. The graphite-like surface layers significantly influence the electron emission properties of these films. Low-energy carbon species can be responsible for the formation of graphite-like surface layers. Nanoscale electron emission measurements have revealed the inhomogeneous emission nature of these films. The low-field emission from these films can be attributed to the existence of sp 2 -configured nanoclusters inside the films

  2. Ranges, Reflection and Secondary Electron Emission for keV Hydrogen Ions Incident on Solid N2

    DEFF Research Database (Denmark)

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

    1983-01-01

    Ranges were measured for 0.67–3.3 keV/amu hydrogen and deuterium ions in solid N2. Comparisons with similar results for N2-gas confirm the previously observed large phase effect in the stopping cross section. Measurements of the secondary electron emission coefficient for bulk solid N2 bombarded...... by 0.67–9 keV/amu ions also seem to support such a phase effect. It is argued that we may also extract information about the charge state of reflected projectiles....

  3. Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

    Science.gov (United States)

    Cernusca, S.; Winter, HP.; Aumayr, F.; Díez Muiño, R.; Juaristi, J. I.

    2003-04-01

    Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to "projectile molecular effects" (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials.

  4. Switching to a U.S. hydrogen fuel cell vehicle fleet: The resultant change in emissions, energy use, and greenhouse gases

    Science.gov (United States)

    Colella, W. G.; Jacobson, M. Z.; Golden, D. M.

    This study examines the potential change in primary emissions and energy use from replacing the current U.S. fleet of fossil-fuel on-road vehicles (FFOV) with hybrid electric fossil fuel vehicles or hydrogen fuel cell vehicles (HFCV). Emissions and energy usage are analyzed for three different HFCV scenarios, with hydrogen produced from: (1) steam reforming of natural gas, (2) electrolysis powered by wind energy, and (3) coal gasification. With the U.S. EPA's National Emission Inventory as the baseline, other emission inventories are created using a life cycle assessment (LCA) of alternative fuel supply chains. For a range of reasonable HFCV efficiencies and methods of producing hydrogen, we find that the replacement of FFOV with HFCV significantly reduces emission associated with air pollution, compared even with a switch to hybrids. All HFCV scenarios decrease net air pollution emission, including nitrogen oxides, volatile organic compounds, particulate matter, ammonia, and carbon monoxide. These reductions are achieved with hydrogen production from either a fossil fuel source such as natural gas or a renewable source such as wind. Furthermore, replacing FFOV with hybrids or HFCV with hydrogen derived from natural gas, wind or coal may reduce the global warming impact of greenhouse gases and particles (measured in carbon dioxide equivalent emission) by 6, 14, 23, and 1%, respectively. Finally, even if HFCV are fueled by a fossil fuel such as natural gas, if no carbon is sequestered during hydrogen production, and 1% of methane in the feedstock gas is leaked to the environment, natural gas HFCV still may achieve a significant reduction in greenhouse gas and air pollution emission over FFOV.

  5. Process flow sheet evaluation of a nuclear hydrogen steelmaking plant applying very high temperature reactors for efficient steel production with less CO{sub 2} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Seiji, E-mail: kasahara.seiji@jaea.go.jp; Inagaki, Yoshiyuki; Ogawa, Masuro

    2014-05-01

    Highlights: • CO{sub 2} emissions from a nuclear hydrogen steelmaking system was 13–21% of that from a blast furnace steelmaking system. • Heat input to shaft furnace in hydrogen steelmaking was large with much H{sub 2} consumption in the part. • Though hydrogen production thermal efficiency had influence on total heat input to hydrogen steelmaking, the effect on the CO{sub 2} emissions was small. • Steelmaking scale of a nuclear hydrogen steelamking plant with 2 VHTRs was a little smaller than that of the largest Midrex{sup ®} steelmaking plants. - Abstract: Recently, CO{sub 2} reduction is an important problem for steelmaking. Substitution of coal, presently used as a reducing agent of iron ore in blast furnaces, to hydrogen produced by non-fossil energy is a way to reduce CO{sub 2} emissions. In this study, the idea of nuclear hydrogen steelmaking (NHS) system was investigated using very high temperature reactor (VHTR) and thermochemical hydrogen production iodine–sulfur (IS) process. Heat input and CO{sub 2} emissions including material production, material transportation, and electricity generation were evaluation criteria. Results of the NHS system were compared with those of a conventional blast furnace steelmaking (BFS) system. Influence of heat input options to the steelmaking process and hydrogen production thermal efficiency of IS process were investigated for the NHS system. Though heat input to the NHS system was 130–142% of that to the BFS system, CO{sub 2} emissions of the system were 13–21%. Pre-heating of hydrogen by coal combustion before blowing to a shaft furnace was effective to decrease heat input, although CO{sub 2} emissions increased. Direct pre-heating by nuclear heat was also effective without increase of CO{sub 2} emissions if close location of the nuclear reactor to the steelmaking plant was publicly accepted. Hydrogen production thermal efficiency had a significant influence on the heat input. Conceptual design of a

  6. PRESSURE SHIFT AND GRAVITATIONAL REDSHIFT OF BALMER LINES IN WHITE DWARFS: REDISCUSSION

    Energy Technology Data Exchange (ETDEWEB)

    Halenka, Jacek; Olchawa, Wieslaw [Institute of Physics, University of Opole, ul. Oleska 48, 45-052, Opole (Poland); Madej, Jerzy [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Grabowski, Boleslaw, E-mail: halenka@uni.opole.pl, E-mail: wolch@uni.opole.pl, E-mail: jm@astrouw.edu.pl, E-mail: bgrab@uni.opole.pl [Wroclaw School of Information Technology WWSIS “Horyzont,” ul. Wejherowska 28, 54-239 Wroclaw (Poland)

    2015-08-01

    The Stark-induced shift and asymmetry, the so-called pressure shift (PS) of H{sub α} and H{sub β} Balmer lines in spectra of DA white dwarfs (WDs), have been examined in detail as masking effects in measurements of the gravitational redshift in WDs. The results are compared with our earlier ones from a quarter of a century ago. In these earlier papers, the standard, symmetrical Stark line profiles, as a dominant constituent of the Balmer line profiles but shifted as a whole by the PS effect, were applied to all spectrally active layers of the WD atmosphere. At present, in each of the WD layers, the Stark line profiles (especially of H{sub β}) are inherently asymmetrical and shifted due to the effects of strong inhomogeneity of the perturbing fields in plasma. To calculate the Stark line profiles in successive layers of the WD atmosphere we used the modified Full Computer Simulation Method, able to take adequately into account the complexity of local elementary quantum processes in plasma. In the case of the H{sub α} line, the present value of Stark-induced shift of the synthetic H{sub α} line profile is about half the previous one and it is negligible in comparison with the gravitational redshift. In the case of the H{sub β} line, the present value of Stark-induced shift of the synthetic H{sub β} line profile is about twice the previous one. The source of this extra shift is the asymmetry of H{sub β} peaks.

  7. Calculation of emission from hydrogenic ions in super liquid density plasmas

    International Nuclear Information System (INIS)

    Bailey, D.S.; Valeo, E.J.

    1976-01-01

    Previous calculations of line emission were extended to higher density, lower temperature plasmas, typical of those expected in early ablative compression experiments. Emission from Ne-seeded fuel was analyzed in order to diagnose the density and temperature of the compressed core. The Stark/Doppler broadened emission profile is calculated for the H-like Ne resonance line. The observable lineshape is then obtained by time-averaging over expected density and temperature profiles and by including the effects of radiative transfer

  8. Performance and emission characteristics of a turbocharged spark-ignition hydrogen-enriched compressed natural gas engine under wide open throttle operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Fanhua; Wang, Mingyue; Jiang, Long; Deng, Jiao; Chen, Renzhe; Naeve, Nashay; Zhao, Shuli [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2010-11-15

    This paper investigates the effect of various hydrogen ratios in HCNG (hydrogen-enriched compressed natural gas) fuels on performance and emission characteristics at wide open throttle operating conditions using a turbocharged spark-ignition natural gas engine. The experimental data was taken at hydrogen fractions of 0%, 30% and 55% by volume and was conducted under different excess air ratio ({lambda}) at MBT operating conditions. It is found that under various {lambda}, the addition of hydrogen can significantly reduce CO, CH{sub 4} emissions and the NO{sub x} emission remain at an acceptable level when ignition timing is optimized. Using the same excess air ratio, as more hydrogen is added the power, exhaust temperatures and max cylinder pressure decrease slowly until the mixture's lower heating value remains unchanged with the hydrogen enrichment, then they rise gradually. In addition, the early flame development period and the flame propagation duration are both shorter, and the indicated thermal efficiency and maximum heat release rate both increase with more hydrogen addition. (author)

  9. Photoelectron emission yield experiments on evolution of sub-gap states in amorphous In-Ga-Zn-O thin films with post deposition hydrogen treatment

    International Nuclear Information System (INIS)

    Hayashi, Kazushi; Hino, Aya; Tao, Hiroaki; Ochi, Mototaka; Goto, Hiroshi; Kugimiya, Toshihiro

    2015-01-01

    Total photoyield emission spectroscopy (TPYS) was applied to study the evolution of sub-gap states in hydrogen-treated amorphous In-Ga-Zn-O (a-IGZO) thin films. The a-IGZO thin films were subjected to hydrogen radicals and subsequently annealed in ultra-high vacuum (UHV) conditions. A clear onset of the electron emission was observed at around 4.3 eV from the hydrogen-treated a-IGZO thin films. After successive UHV annealing at 300 °C, the onset in the TPYS spectra was shifted to 4.15 eV, and the photoelectron emission from the sub-gap states was decreased as the annealing temperature was increased. In conjunction with the results of thermal desorption spectrometer, it was deduced that the hydrogen atoms incorporated in the a-IGZO thin films induced metastable sub-gap states at around 4.3 eV from vacuum level just after the hydrogenation. It was also suggested that the defect configuration was changed due to the higher temperature UHV annealing, and that the hydrogen atoms desorbed with the involvement of Zn atoms. These experiments produced direct evidence to show the formation of sub-gap states as a result of hydrogen incorporation into the a-IGZO thin films

  10. Photoelectron emission yield experiments on evolution of sub-gap states in amorphous In-Ga-Zn-O thin films with post deposition hydrogen treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Kazushi, E-mail: hayashi.kazushi@kobelco.com; Hino, Aya; Tao, Hiroaki; Ochi, Mototaka; Goto, Hiroshi; Kugimiya, Toshihiro [Electronics Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsuka-dai, Nishi-ku, Kobe 651-2271 (Japan)

    2015-09-14

    Total photoyield emission spectroscopy (TPYS) was applied to study the evolution of sub-gap states in hydrogen-treated amorphous In-Ga-Zn-O (a-IGZO) thin films. The a-IGZO thin films were subjected to hydrogen radicals and subsequently annealed in ultra-high vacuum (UHV) conditions. A clear onset of the electron emission was observed at around 4.3 eV from the hydrogen-treated a-IGZO thin films. After successive UHV annealing at 300 °C, the onset in the TPYS spectra was shifted to 4.15 eV, and the photoelectron emission from the sub-gap states was decreased as the annealing temperature was increased. In conjunction with the results of thermal desorption spectrometer, it was deduced that the hydrogen atoms incorporated in the a-IGZO thin films induced metastable sub-gap states at around 4.3 eV from vacuum level just after the hydrogenation. It was also suggested that the defect configuration was changed due to the higher temperature UHV annealing, and that the hydrogen atoms desorbed with the involvement of Zn atoms. These experiments produced direct evidence to show the formation of sub-gap states as a result of hydrogen incorporation into the a-IGZO thin films.

  11. The broad component of hydrogen emission lines in nuclei of Seyfert galaxies: Comments on a charge exchange model

    International Nuclear Information System (INIS)

    Katz, A.

    1975-01-01

    A model to account for the broad hydrogen line emission from the nuclei of Seyfert galaxies based on charge exchange and collisional processes, as proposed by Ptak and Stoner, is investigated. The model consists of a source of fast (E approx. 10 5 eV) protons streaming through a medium of quiescent gas. One of the major problems that results from such a model concerns the strong narrow hydrogen line core that would be produced, in direct conflict with the observations. The lines cannot arise from gas arranged throughout a spherical volume surrounding the source of the fast particles because the fast protons would produce far more ionizations than the possible number of recombinations. A very dense shell source of less than 1 AU in thickness and at least several tens of parsecs in radius must be invoked to reproduce the asymmetric broad profiles observed. There must be absorption throughout the center of the shell to account for the line profiles. The gas cannot be arranged in dense clumps throughout a large volume because momentum exchange of the gas with the primary particles would quickly accelerate any clumps. The energy balance and energy requirements of such a model are investigated, and it is found that an energy equal to or greater than the total luminosity of most Seyfert galaxies is required to produce the hydrogen line alone. The gas must be mostly neutral and den []e (N approx. 10 7 ) if a reasonable temperature is to be maintained

  12. Variations of the high-level Balmer line spectrum of the helium-strong star σ Orionis E

    Science.gov (United States)

    Smith, M. A.; Bohlender, D. A.

    2007-12-01

    Using the high-level Balmer lines and continuum, we trace the density structure of two magnetospheric disk segments of the prototypical Bp star σ Orionis E (B2p) as these segments occult portions of the star during the rotational cycle. High-resolution spectra of the Balmer lines ≥H9 and Balmer edge were obtained on seven nights in January-February 2007 at an average sampling of 0.01 cycles. We measured equivalent width variations due to the star occultations by two disk segments 0.4 cycles apart and constructed differential spectra of the migrations of the corresponding absorptions across the Balmer line profiles. We first estimated the rotational and magnetic obliquity angles. We then simulated the observed Balmer jump variation using the model atmosphere codes synspec/circus and evaluated the disk geometry and gas thermodynamics. We find that the two occultations are caused by two disk segments. The first of these transits quickly, indicating that the segment resides in a range of distances, perhaps 2.5-6 R*, from the star. The second consists of a more slowly moving segment situated closer to the surface and causing two semi-resolved absorbing maxima. During its transit this segment brushes across the star's “lower” limb. Judging from the line visibility up to H23-H24 during the occultations, both disk segments have mean densities near 1012 cm-3 and are opaque in the lines and continuum. They have semiheights less than 1/2 R*, and their temperatures are near 10 500 K and 12 000 K, respectively. In all, the disks of Bp stars have a much more complicated geometry than has been anticipated, as evidenced by their (sometimes) non-coplanarity, de-centerness, and from star to star, differences in disk height. Based on observations obtained at the the Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada.

  13. Robust, Reliable Low Emission Gas Turbine Combustion of High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, Margaret Stacy [Univ. of Michigan, Ann Arbor, MI (United States); Im, Hong Geum [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-12-16

    The effects of high hydrogen content fuels were studied using experimental, computational and theoretical approaches to understand the effects of mixture and state conditions on the ignition behavior of the fuels. A rapid compression facility (RCF) was used to measure the ignition delay time of hydrogen and carbon monoxide mixtures. The data were combined with results of previous studies to develop ignition regime criteria. Analytical theory and direct numerical simulation were used to validate and interpret the RCF ignition data. Based on the integrated information the ignition regime criteria were extended to non-dimensional metrics which enable application of the results to practical gas turbine combustion systems.

  14. Effect of dietary nitrate level on enteric methane production, hydrogen emission, rumen fermentation, and nutrient digestibility in dairy cows.

    Science.gov (United States)

    Olijhoek, D W; Hellwing, A L F; Brask, M; Weisbjerg, M R; Højberg, O; Larsen, M K; Dijkstra, J; Erlandsen, E J; Lund, P

    2016-08-01

    Nitrate may lower methane production in ruminants by competing with methanogenesis for available hydrogen in the rumen. This study evaluated the effect of 4 levels of dietary nitrate addition on enteric methane production, hydrogen emission, feed intake, rumen fermentation, nutrient digestibility, microbial protein synthesis, and blood methemoglobin. In a 4×4 Latin square design 4 lactating Danish Holstein dairy cows fitted with rumen, duodenal, and ileal cannulas were assigned to 4 calcium ammonium nitrate addition levels: control, low, medium, and high [0, 5.3, 13.6, and 21.1g of nitrate/kg of dry matter (DM), respectively]. Diets were made isonitrogenous by replacing urea. Cows were fed ad libitum and, after a 6-d period of gradual introduction of nitrate, adapted to the corn-silage-based total mixed ration (forage:concentrate ratio 50:50 on DM basis) for 16d before sampling. Digesta content from duodenum, ileum, and feces, and rumen liquid were collected, after which methane production and hydrogen emissions were measured in respiration chambers. Methane production [L/kg of dry matter intake (DMI)] linearly decreased with increasing nitrate concentrations compared with the control, corresponding to a reduction of 6, 13, and 23% for the low, medium, and high diets, respectively. Methane production was lowered with apparent efficiencies (measured methane reduction relative to potential methane reduction) of 82.3, 71.9, and 79.4% for the low, medium, and high diets, respectively. Addition of nitrate increased hydrogen emissions (L/kg of DMI) quadratically by a factor of 2.5, 3.4, and 3.0 (as L/kg of DMI) for the low, medium, and high diets, respectively, compared with the control. Blood methemoglobin levels and nitrate concentrations in milk and urine increased with increasing nitrate intake, but did not constitute a threat for animal health and human food safety. Microbial crude protein synthesis and efficiency were unaffected. Total volatile fatty acid

  15. Effects of curcumin and ursolic acid on the mitochondrial coupling efficiency and hydrogen peroxide emission of intact skeletal myoblasts.

    Science.gov (United States)

    Tueller, Daniel J; Harley, Jackson S; Hancock, Chad R

    2017-10-21

    Curcumin may improve blood glucose management, but the mechanism is not fully established. We demonstrated that curcumin (40 μM) reduced the mitochondrial coupling efficiency (percentage of oxygen consumption coupled to ATP synthesis) of intact skeletal muscle cells. A 30-minute pretreatment with curcumin reduced mitochondrial coupling efficiency by 17.0 ± 0.4% relative to vehicle (p Curcumin pretreatment also decreased the rate of hydrogen peroxide emission by 43 ± 13% compared to vehicle (p curcumin revealed a 40 ± 4% increase in the rate of oxygen consumption upon curcumin administration (p curcumin-pretreated cells after permeabilization of cell membranes (p > 0.7). The interaction between curcumin and ursolic acid, another natural compound that may improve blood glucose management, was also examined. Pretreatment with ursolic acid (0.12 μM) increased the mitochondrial coupling efficiency of intact cells by 4.1 ± 1.1% relative to vehicle (p curcumin when the two compounds were used in combination. The observed changes to mitochondrial coupling efficiency and hydrogen peroxide emission were consistent with the established effects of curcumin on blood glucose control. Our findings also show that changes to mitochondrial coupling efficiency after curcumin pretreatment may go undetected unless cells are assessed in the intact condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Study of the light emission from hydrogen atoms excited by the beam-foil technique

    International Nuclear Information System (INIS)

    Broll, Norbert.

    1976-01-01

    Zero-field and Stark-induced quantum beat measurements have been performed for beam foil excited hydrogen (H + and H 2 + beam). Experimental evidence of coherent excitation of S and P states of Lyman α line has been demonstrated [fr

  17. Two photon emission by hydrogen-like atoms in high temperature plasmas

    International Nuclear Information System (INIS)

    Costescu, A.; Manzatu, I.; Dinu, C.; Mihailescu, I.N.

    1981-08-01

    New exact solutions and a rather simple polynomial expression of the power emitted in the two photon transition from a metastable 2s state to the ground state of a hydrogen-like atom were infered with the aid of the Coulomb Green's function method. It was shown that the two photon decay represents under certain circumstances a significant power loss mechanism. (authors)

  18. Ultra slow muon generation and thermionic emission of hydrogen isotopes from tungsten surface

    International Nuclear Information System (INIS)

    Miyake, Yasuhiro

    2000-01-01

    To generate ultra slow muon, we developed Lyman α light (Lα light) resonance ionization method using 1s-2p-unbound transition. By this method, the desorption process of hydrogen isotope and hydrogen atom generation were studied. In order to generate T atom, the laser resonance ionization of hydrogen nucleus was investigated. When wavelength of VUV light was fixed to 121.52 nm, 1s-2p resonance frequency of T, and VUV light agreed with 355 nm ionization laser in space and time, promising event was observed. The fact showed the resonance ionization method could isolate and detect T atom. By the same method, the experiment of H and D atom were carried out under the condition of the same wavelength of VUV light of 121.57 and 121.53 nm of Lα light, respectively, and the same results were obtained. On the Mu resonance ionization experiment, the light wavelength of VUV was 122.09 nm of Lα of muonium. The results showed the promising event was observed on the expected position of TOF and Mass. The resonance ionization method using Lα light of hydrogen isotope on tungsten film is a very useful method to separate Mu, H, D and T under the same experiment conditions without wavelength of VUV light. (S.Y.)

  19. AN INTEGRATED ASSESSMENT OF THE IMPACTS OF HYDROGEN ECONOMY ON TRANSPORTATION, ENERGY USE, AND AIR EMISSIONS

    Science.gov (United States)

    This paper presents an analysis of the potential energy, economic and environmental implications of hydrogen fuel cell vehicle (H2-FCV) penetration into the U.S. light duty vehicle fleet. The approach, which uses the U.S. EPA MARKet ALlocation technology database and model, allow...

  20. Interaction of 14 MeV neutrons with hydrogenated target proton emission calculation

    International Nuclear Information System (INIS)

    Martin, G.; Perez, N.; Desdin.

    1996-01-01

    Using neutron emission data of a 14 MeV neutron generator, a paraffin target, and based on the n + H 1 → n '+ p reaction, have been obtained the characteristics of the proton emission in a proton-neutron mixed field. It was used Monte Carlo simulation and it was obtained the proton output as function of the converter width and the energy spectrum of protons corresponding to different converter thickness. Among 0.07 and 0.2 cm there is a maximum zone for the proton emission. The energy spectrum agrees with obtained on previous papers. Figures showing these results are provided

  1. Emission of hydrogen sulfide by leaf tissue in response to L-cysteine

    International Nuclear Information System (INIS)

    Sekiya, J.; Schmidt, A.; Wilson, L.G.; Filner, P.

    1982-01-01

    Leaf discs and detached leaves exposed to L-cysteine emitted a volatile sulfur compound which was proven by gas chromatography to be H 2 S. This phenomenon was demonstrated in all nine species tested (Cucumis sativus, Cucurbita pepo, Nicotiana tabacum, Coleus blumei, Beta vulgaris, Phaseolus vulgaris, Medicago sativa, Hordeum vulgare, and Gossypium hirsutum). The emission of volatile sulfur by cucumber leaves occurred in the dark at a similar rate to that in the light. The emission of leaf discs reached the maximal rate, more than 40 picomoles per minute per square centimeter, 2 to 4 hours after starting exposure to L-cysteine; then it decreased. In the case of detached leaves, the maximum occurred 5 to 10 h after starting exposure. The average emission rate of H 2 S during the first 4 hours from leaf discs of cucurbits in response to 10 millimolar L-cysteine, was usually more than 40 picomoles per minute per square centimeter, i.e. 0.24 micromoles per hour per square decimeter. Leaf discs exposed to 1 millimolar L-cysteine emitted only 2% as much as did the discs exposed to 10 millimolar L-cysteine. The emission from leaf discs and from detached leaves lasted for at least 5 and 15 hours, respectively. However, several hours after the maximal emission, injury of the leaves, manifested as chlorosis, was evident. H 2 S emission was a specific consequence of exposure to L-cysteine; neither D-cysteine nor L-cysteine elicited H 2 S emission. Aminooxyacetic acid, an inhibitor of pyridoxal phosphate dependent enzymes, inhibited the emission. In a cell free system from cucumber leaves, H 2 S formation and its release occurred in response to L-cysteine. Feeding experiments with [ 35 S]t-cysteine showed that most of the sulfur in H 2 S was derived from sulfur in the L-cysteine supplied

  2. Performance and specific emissions contours throughout the operating range of hydrogen-fueled compression ignition engine with diesel and RME pilot fuels

    Directory of Open Access Journals (Sweden)

    Shahid Imran

    2015-09-01

    Full Text Available This paper presents the performance and emissions contours of a hydrogen dual fueled compression ignition (CI engine with two pilot fuels (diesel and rapeseed methyl ester, and compares the performance and emissions iso-contours of diesel and rapeseed methyl ester (RME single fueling with diesel and RME piloted hydrogen dual fueling throughout the engines operating speed and power range. The collected data have been used to produce iso-contours of thermal efficiency, volumetric efficiency, specific oxides of nitrogen (NOX, specific hydrocarbons (HC and specific carbon dioxide (CO2 on a power-speed plane. The performance and emission maps are experimentally investigated, compared, and critically discussed. Apart from medium loads at lower and medium speeds with diesel piloted hydrogen combustion, dual fueling produced lower thermal efficiency everywhere across the map. For diesel and RME single fueling the maximum specific NOX emissions are centered at the mid speed, mid power region. Hydrogen dual fueling produced higher specific NOX with both pilot fuels as compared to their respective single fueling operations. The range, location and trends of specific NOX varied significantly when compared to single fueling cases. The volumetric efficiency is discussed in detail with the implications of manifold injection of hydrogen analyzed with the conclusions drawn.

  3. Dynamis - a step towards the first HYPOGEN plant, producing hydrogen and electricity with near zero emissions

    Energy Technology Data Exchange (ETDEWEB)

    Petter E. Roekke; Nils A. Roekke; Jens Hetland; Peter Radgen; Clemens Cremer; Tore A. Torp [SINTEF Energy Research, Trondheim (Norway)

    2006-07-01

    This paper refers to the Dynamis project, which represents the second phase of the route towards the HYPOGEN initiative of the European Commission, building on results and experience from the HYPOGEN pre-feasibility study. The paper will describe the European policy of enabling hydrogen as a more significant energy carrier in Europe, through processing of fossil fuels to hydrogen and electricity with CO{sub 2} capture and storage. The paper will address the two first phases of the endeavor; the HYPOGEN pre-feasibility study was completed in 2005, and Dynamis was started early 2006. Both relate to the technical, economic and societal pre-requisites of each dimension to early decisions in order for a HYPOGEN plant to go on stream by 2012. 9 refs., 2 figs.

  4. Performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas

    Energy Technology Data Exchange (ETDEWEB)

    Roy, M.M.; Tomita, E.; Kawahara, N.; Harada, Y.; Sakane, A. [Okayama University, Okayama (Japan). Dept. of Mechanical Engineering

    2009-12-15

    This study investigated the engine performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas and ignited by a pilot amount of diesel fuel. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with exhaust gas recirculation (EGR). The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first without EGR condition up to the maximum possible fuel-air equivalence ratio of 0.65. A maximum indicated mean effective pressure (IMEP) of 1425 kPa and a thermal efficiency of 39% were obtained. However, the nitrogen oxides (NOx) emissions were high. A simulated EGR up to 50% was then performed to obtain lower NOx emissions. The maximum reduction of NOx was 60% or more maintaining the similar levels of IMEP and thermal efficiency. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion.

  5. THE INFRARED SPECTRUM OF PROTONATED OVALENE IN SOLID PARA-HYDROGEN AND ITS POSSIBLE CONTRIBUTION TO INTERSTELLAR UNIDENTIFIED INFRARED EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Tsuge, Masashi; Bahou, Mohammed; Lee, Yuan-Pern [Department of Applied Chemistry and Institute of Molecular Sciences, National Chiao Tung University, 1001, Ta-Hsueh Road, Hsinchu 30010, Taiwan (China); Wu, Yu-Jong [National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 30076, Taiwan (China); Allamandola, Louis, E-mail: tsuge@nctu.edu.tw, E-mail: yplee@mail.nctu.edu.tw [The Astrophysics and Astrochemistry Laboratory, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2016-07-10

    The mid-infrared emission from galactic objects, including reflection nebulae, planetary nebulae, proto-planetary nebulae, molecular clouds, etc, as well as external galaxies, is dominated by the unidentified infrared (UIR) emission bands. Large protonated polycyclic aromatic hydrocarbons (H{sup +}PAHs) were proposed as possible carriers, but no spectrum of an H{sup +}PAH has been shown to exactly match the UIR bands. Here, we report the IR spectrum of protonated ovalene (7-C{sub 32}H{sub 15} {sup +}) measured in a para -hydrogen ( p -H{sub 2}) matrix at 3.2 K, generated by bombarding a mixture of ovalene and p -H{sub 2} with electrons during matrix deposition. Spectral assignments were made based on the expected chemistry and on the spectra simulated with the wavenumbers and infrared intensities predicted with the B3PW91/6-311++G(2d,2p) method. The close resemblance of the observed spectral pattern to that of the UIR bands suggests that protonated ovalene may contribute to the UIR emission, particularly from objects that emit Class A spectra, such as the IRIS reflection nebula, NGC 7023.

  6. Shape of the Hα emission line in non resonant charge exchange in hydrogen plasmas

    International Nuclear Information System (INIS)

    Susino Bueno, A.; Zurro Hernandez, B.

    1977-01-01

    The Hα line shape emitted from a maxwellian hydrogen plasma and produced by non resonant change exchange has been calculated. Its explicit shape depends on the ion temperature, on background neutral energy and on the relative shape of the collision cross section. A comparison between theoretical and experimental shapes of the Hα line is carried out to check the model and to deduce the ion plasma temperature. (author) [es

  7. Frequency dependence of coherently amplified two-photon emission from hydrogen molecules

    Science.gov (United States)

    Hara, Hideaki; Miyamoto, Yuki; Hiraki, Takahiro; Masuda, Takahiko; Sasao, Noboru; Uetake, Satoshi; Yoshimi, Akihiro; Yoshimura, Koji; Yoshimura, Motohiko

    2017-12-01

    We investigate how the efficiency of coherently amplified two-photon emission depends on the frequency of one of the two emitted photons, namely the signal photon. This is done over the wavelength range of 5.048-10.21 μ m by using the vibrational transition of parahydrogen. The efficiency increases with the frequency of the signal photon. Considering experimental errors, our results are consistent with the theoretical prediction for the present experimental conditions. This study is an experimental demonstration of the frequency dependence of coherently amplified two-photon emission, and also presents its potential as a light source.

  8. Emission lines in the hydrogen-deficient variable MV Sagittarii near maximum light

    International Nuclear Information System (INIS)

    Herbig, G.H.

    1975-01-01

    The H-deficient R CrB type variable MV Sgr near maximum light shows a rich emission spectrum in the 5800--8600 A region. Most of these lines are due to Fe ii, but Si ii, N i, O i, and Hα also are present. Such a spectrum has not been observed in any other R CrB star, but there is some resemblance to v Sgr. The emission lines in MV Sgr probably originate in an extended region of low temperature, which may also be responsible for the infrared excess observed by Feast and Glass

  9. Line-emission cross sections for the charge-exchange reaction between fully stripped carbon and atomic hydrogen in tokamak plasma

    International Nuclear Information System (INIS)

    Ida, K.; Kato, T.

    1992-01-01

    Line-emission cross sections of the charge-exchange reaction between fully stripped carbon and atomic hydrogen are measured in the energy range of 18 - 38 keV/amu in tokamak plasmas. The energy dependence of the emission cross sections for the transition of Δn = 8 - 7 and Δn = 7 - 6 and their ratios are compared with theoretical calculations. (author)

  10. Cosmology on ultralarge scales with intensity mapping of the neutral hydrogen 21 cm emission: limits on primordial non-Gaussianity.

    Science.gov (United States)

    Camera, Stefano; Santos, Mário G; Ferreira, Pedro G; Ferramacho, Luís

    2013-10-25

    The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z=/~1-5 are the best hope of accessing the ultralarge-scale information, directly related to the early Universe. A purpose-built HI intensity experiment may be used to detect the large scale effects of primordial non-Gaussianity, placing stringent bounds on different models of inflation. We argue that it may be possible to place tight constraints on the non-Gaussianity parameter f(NL), with an error close to σ(f(NL))~1.

  11. Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

    International Nuclear Information System (INIS)

    Cernusca, S.; Winter, H.P.; Aumayr, F.; Diez Muino, R.; Juaristi, J.I.

    2003-01-01

    Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy <10 keV) on atomically clean surfaces of carbon-fiber inforced graphite used as first-wall armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to 'projectile molecular effects' (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials

  12. Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

    CERN Document Server

    Cernusca, S; Aumayr, F; Diez-Muino, R; Juaristi, J I

    2003-01-01

    Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy <10 keV) on atomically clean surfaces of carbon-fiber inforced graphite used as first-wall armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to 'projectile molecular effects' (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials.

  13. Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 2

    Science.gov (United States)

    Kelly, R. L.

    1979-01-01

    A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

  14. Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 1

    Science.gov (United States)

    Kelly, R. L.

    1979-01-01

    A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

  15. Hydrogen atom temperature measured with wavelength-modulated laser absorption spectroscopy in large scale filament arc negative hydrogen ion source

    International Nuclear Information System (INIS)

    Nakano, H.; Goto, M.; Tsumori, K.; Kisaki, M.; Ikeda, K.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Nishiyama, S.; Sasaki, K.

    2015-01-01

    The velocity distribution function of hydrogen atoms is one of the useful parameters to understand particle dynamics from negative hydrogen production to extraction in a negative hydrogen ion source. Hydrogen atom temperature is one of the indicators of the velocity distribution function. To find a feasibility of hydrogen atom temperature measurement in large scale filament arc negative hydrogen ion source for fusion, a model calculation of wavelength-modulated laser absorption spectroscopy of the hydrogen Balmer alpha line was performed. By utilizing a wide range tunable diode laser, we successfully obtained the hydrogen atom temperature of ∼3000 K in the vicinity of the plasma grid electrode. The hydrogen atom temperature increases as well as the arc power, and becomes constant after decreasing with the filling of hydrogen gas pressure

  16. Improvement of performance and reduction of pollutant emission of a four stroke spark ignition engine fueled with hydrogen-gasoline fuel mixture

    Energy Technology Data Exchange (ETDEWEB)

    Al-Baghdadi, Maher Abdul-Resul Sadiq; Al-Janabi, Haroun Abdul-Kadim Shahad [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Iraq)

    2000-07-01

    The effect of the amount of hydrogen/ethyl alcohol addition on the performance and pollutant emissions of a four stroke spark ignition engine has been studied. A detailed model to simulate a four stroke cycle of a spark ignition engine fueled with hydrogen-ethyl alcohol-gasoline has been used to study the effect of hydrogen and ethyl alcohol blending on the thermodynamic cycle of the engine. The results of the study show that all engine performance parameters have been improved when operating the gasoline S.I.E. with dual addition of hydrogen and ethyl alcohol. It has been found that 4% of hydrogen and 30% of ethyl alcohol blending causes a 49% reduction in CO emission, a 39% reduction in NO{sub x} emission, a 49% reduction in specific fuel consumption and increases in the thermal efficiency and output power by 5 and 4%, respectively. When ethyl alcohol is increased over 30%, it causes unstable engine operation which can be related to the fact that the fuel is not vaporised, and this causes a reduction in both the brake power and efficiency. (Author)

  17. Unmodified versus caustics-impregnated carbons for control of hydrogen sulfide emissions from sewage treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Bandosz, T.J.; Bagreev, A.; Adib, F.; Turk, A.

    2000-03-15

    Unmodified and caustic-impregnated carbons were compared as adsorbents for hydrogen sulfide in the North River Water Pollution Control Plant in New York City over a period of 2 years. The carbons were characterized using accelerated H{sub 2}S breakthrough capacity tests, sorption of nitrogen, potentiometric titration, and thermal analysis. The accelerated laboratory tests indicate that the initial capacity of caustic-impregnated carbons exceeds that of unmodified carbon, but the nature of real-life challenge streams, particularly their lower H{sub 2}S concentrations, nullifies this advantage. As the caustic content of the impregnated carbon is consumed, the situation reverses, and the unmodified carbon becomes more effective. When the concentration of H{sub 2}S is low, the developed surface area and pore volume along with the affinity to retain water create a favorable environment for dissociative adsorption of hydrogen sulfide and its oxidation to elemental sulfur, S{sup 4+}, and S{sup 6+}. In the case of the caustic carbon, the catalytic impact of the carbon surface is limited, and its good performance lasts only while active base is present. The results also show the significant differences in performance of unmodified carbons due to combined effects of their porosity and surface chemistry.

  18. Economic feasibility of hydrogen enrichment for reducing NOx emissions from landfill gas power generation alternatives: A comparison of the levelized cost of electricity with present strategies

    International Nuclear Information System (INIS)

    Kornbluth, Kurt; Greenwood, Jason; Jordan, Eddie; McCaffrey, Zach; Erickson, Paul A.

    2012-01-01

    Based on recent research showing that hydrogen enrichment can lower NO x emissions from landfill gas combustion below future NO x emission control standards imposed by both federal and California state regulations, an investigation was performed to compare the levelized cost of electricity of this technology with other options. In this cost study, a lean-burn reciprocating engine with no after-treatment was the baseline case to compare six other landfill gas-to-energy projects. These cases include a lean burn engine with selective catalytic reduction after treatment, a lean-burn microturbine, and four variations on an ultra-lean-burn engine utilizing hydrogen enrichment with each case using a different method of hydrogen production. Only hydrogen enrichment with an in-stream autothermal fuel reformer was shown to be potentially cost-competitive with current strategies for reaching the NO x reduction target in IC engines. - Highlights: ► Levelized cost of electricity for hydrogen enriched combustion was compared. ► Various ultra-lean-burn engines and microturbines with hydrogen were analyzed. ► Combustion with an autothermal fuel reformer was potentially cost-competitive.

  19. Hydrogen Fuel Cell Vehicle Fuel Economy Testing at the U.S. EPA National Vehicle and Fuel Emissions Laboratory (SAE Paper 2004-01-2900)

    Science.gov (United States)

    The introduction of hydrogen fuel cell vehicles and their new technology has created the need for development of new fuel economy test procedures and safety procedures during testing. The United States Environmental Protection Agency-National Vehicle Fuels and Emissions Laborato...

  20. Combination of borax and quebracho condensed tannins treatment to reduce hydrogen sulfide, ammonia and greenhouse gas emissions from stored swine manure

    Science.gov (United States)

    Livestock producers are acutely aware for the need to reduce gaseous emissions from stored livestock waste and have been trying to identify new technologies to address the chronic problem. Besides the malodor issue, toxic gases emitted from stored livestock manure, especially hydrogen sulfide (H2S)...

  1. Effect of compression ratio, equivalence ratio and engine speed on the performance and emission characteristics of a spark ignition engine using hydrogen as a fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq Al-Baghdadi, M.A.R. [University of Babylon (Iraq). Dept. of Mechanical Engineering

    2004-12-01

    The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. Researchers have found that hydrogen presents the best and an unprecedented solution to the energy crises and pollution problems, due to its superior combustion qualities and availability. This paper discusses analytically and provides data on the effect of compression ratio, equivalence ratio and engine speed on the engine performance, emissions and pre-ignition limits of a spark ignition engine operating on hydrogen fuel. These data are important in order to understand the interaction between engine performance and emission parameters, which will help engine designers when designing for hydrogen. (author)

  2. Structure reactivity relationships during N2O hydrogenation over Au-Ag alloys: A study by field emission techniques

    Science.gov (United States)

    Jacobs, Luc; Barroo, Cédric; Gilis, Natalia; Lambeets, Sten V.; Genty, Eric; Visart de Bocarmé, Thierry

    2018-03-01

    To make available atomic oxygen at the surface of a catalyst is the key step for oxidation reactions on Au-based catalysts. In this context, Au-Ag alloys catalysts exhibit promising properties for selective oxidation reactions of alcohols: low temperature activity and high selectivity. The presence of O(ads) and its effects on the catalytic reactivity is studied via the N2O dissociative adsorption and subsequent hydrogenation. Field emission techniques are particularly suited to study this reaction: Field Ion Microscopy (FIM) and Field Emission Microscopy (FEM) enable to image the extremity of sharp metallic tips, the size and morphology of which are close to those of one single catalytic particle. The reaction dynamics is studied in the 300-320 K temperature range and at a pressure of 3.5 × 10-3 Pa. The main results are a strong structure/reactivity relationship during N2O + H2 reaction over Au-8.8 at.%Ag model catalysts. Comparison of high-resolution FIM images of the clean sample and FEM images during reaction shows a sensitivity of the reaction to the local structure of the facets, independently of the used partial pressures of both N2O and H2. This suggests a localised dissociative adsorption step for N2O and H2 with the formation of a reactive interface around the {210} facets.

  3. Spontaneous light emission by atomic hydrogen: Fermi's golden rule without cheating

    Science.gov (United States)

    Debierre, V.; Durt, T.; Nicolet, A.; Zolla, F.

    2015-10-01

    Focusing on the 2 p- 1 s transition in atomic hydrogen, we investigate through first order perturbation theory the time evolution of the survival probability of an electron initially taken to be in the excited (2 p) state. We examine both the results yielded by the standard dipole approximation for the coupling between the atom and the electromagnetic field - for which we propose a cutoff-independent regularisation - and those yielded by the exact coupling function. In both cases, Fermi's golden rule is shown to be an excellent approximation for the system at hand: we found its maximal deviation from the exact behaviour of the system to be of order 10-8 /10-7. Our treatment also yields a rigorous prescription for the choice of the optimal cutoff frequency in the dipole approximation. With our cutoff, the predictions of the dipole approximation are almost indistinguishable at all times from the exact dynamics of the system.

  4. Analysis of energy consumption and CO{sub 2} emissions of the life cycle of bio-hydrogen applied to the Portuguese road transportation sector

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ana Filipa; Baptista, Patricia; Silva, Carla [IDMEC (Portugal). Dept. of Mechanical Engineering

    2010-07-01

    In this work the main objective is to analyze energy consumption and CO{sub 2} emissions of biohydrogen for use in the transportation sector in Portugal. A life cycle assessment will be performed in order to evaluate bio-hydrogen pathways, having biodiesel and conventional fossil diesel as reference. The pathways were production of feedstock, pre-treatment, treatment, compression, distribution and applications. For the well-to-tank analysis the SimaPro 7.1 software and excel tools are used. This study includes not only a well-to-tank analysis but also a tank-to-wheel analysis (using ADVISOR software) estimating hydrogen consumption and electricity consumption of a fuel cell hybrid and a plug-in hybrid. Several bio-hydrogen feedstocks to produce hydrogen through fermentation processes will be considered: potato peels. (orig.)

  5. MHOs toward HMOs: A Search for Molecular Hydrogen Emission-Line Objects toward High-mass Outflows

    Energy Technology Data Exchange (ETDEWEB)

    Wolf-Chase, Grace [Astronomy Department Adler Planetarium 1300 S. Lake Shore Drive Chicago, IL 60605 (United States); Arvidsson, Kim [Trull School of Sciences and Mathematics Schreiner University 2100 Memorial Blvd. Kerrville, TX 78028 (United States); Smutko, Michael, E-mail: gwolfchase@adlerplanetarium.org [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), and Dept. of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States)

    2017-07-20

    We present the results of a narrow-band near-infrared imaging survey for Molecular Hydrogen emission-line Objects (MHOs) toward 26 regions containing high-mass protostellar candidates and massive molecular outflows. We have detected a total of 236 MHOs, 156 of which are new detections, in 22 out of the 26 regions. We use H{sub 2} 2.12 μ m/H{sub 2} 2.25 μ m flux ratios, together with morphology, to separate the signatures of fluorescence associated with photo-dissociation regions (PDRs) from shocks associated with outflows in order to identify the MHOs. PDRs have typical low flux ratios of ∼1.5–3, while the vast majority of MHOs display flux ratios typical of C-type shocks (∼6–20). A few MHOs exhibit flux ratios consistent with expected values for J-type shocks (∼3–4), but these are located in regions that may be contaminated with fluorescent emission. Some previously reported MHOs have low flux ratios, and are likely parts of PDRs rather than shocks indicative of outflows. We identify a total of 36 outflows across the 22 target regions where MHOs were detected. In over half these regions, MHO arrangements and fluorescent structures trace features present in CO outflow maps, suggesting that the CO emission traces a combination of dynamical effects, which may include gas entrained in expanding PDRs as well as bipolar outflows. Where possible, we link MHO complexes to distinct outflows and identify candidate driving sources.

  6. Ionization of cloud and intercloud hydrogen by O and B stars

    International Nuclear Information System (INIS)

    Elmergreen, B.G.

    1975-01-01

    Lyman continuum radiation from OB stars may be the primary source of ionization of interstellar hydrogen. Eighty percent of Lyman continuum photons produced by these stars comes from a very small number of 05 and 06 stars, however, and if this radiation is ionized to interstellar hydrogen with the high degree of uniformity indicated by pulsar dispersion measures or by the diffuse background of Hα emission, then each 05 or 06 star must be able to maintain an H II region over a distance of several hundred parsecs. The cloudy structure of interstellar space prevents such long range ionization, however, and a large fraction of the stellar Lyman continuum photons will be converted to Balmer photons in the high-density ionized surfaces of the exposed clouds. Two questions concerning this cloudy obscuration naturally arise: what will be the consequences of a cloud's exposure to Lyman continuum radiation, and to what extent can low-density, intercloud hydrogen be ionized in the obscured regions. These questions are considered

  7. Laboratory Measurements Of Charge-exchange Produced X-ray Emission From K-shell Transitions In Hydrogenic And Helium-like Fe

    Science.gov (United States)

    Brown, Gregory V.; Beiersdorfer, P.; Boyce, K. R.; Chen, H.; Gu, M. F.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Thorn, D.; Wargelin, B.

    2006-09-01

    We have used a microcalorimeter and solid state detectors to measure x-ray emission produced by charge exchange reactions between bare and hydrogenic Fe colliding with neutral helium, hydrogen, and nitrogen gas. We show the measured spectral signature produced by different neutral donors and compare our results to theory where available. We also compare our results to measurements of the Fe K line emission from the Galactic Center measured by the XIS on the Suzaku x-ray observatory. This comparison shows that charge exchange recombination between highly charged ions (either cosmic rays or thermal ions) and neutral gas is probably not the dominant source of diffuse line emission in the Galactic Center. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48, and is also supported by NASA APRA grants to LLNL, GSFC, Harvard-Smithsonian CfA, and Stanford University.

  8. Photoionization-driven Absorption-line Variability in Balmer Absorption Line Quasar LBQS 1206+1052

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Luming; Zhou, Hongyan; Ji, Tuo; Jiang, Peng; Liu, Bo; Pan, Xiang; Shi, Xiheng; Zhang, Shaohua [Polar Research Institute of China, 451 Jinqiao Road, Shanghai (China); Liu, Wenjuan; Wang, Jianguo [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan (China); Wang, Tinggui; Yang, Chenwei [Department of Astronomy, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui (China); Miller, Lauren P., E-mail: lmsun@mail.ustc.edu.cn [Lehigh University, 27 Memorial Drive West, Bethlehem, PA 18015 (United States)

    2017-04-01

    In this paper we present an analysis of absorption-line variability in mini-BAL quasar LBQS 1206+1052. The Sloan Digital Sky Survey spectrum demonstrates that the absorption troughs can be divided into two components of blueshift velocities of ∼700 and ∼1400 km s{sup −1} relative to the quasar rest frame. The former component shows rare Balmer absorption, which is an indicator of high-density absorbing gas; thus, the quasar is worth follow-up spectroscopic observations. Our follow-up optical and near-infrared spectra using MMT, YFOSC, TSpec, and DBSP reveal that the strengths of the absorption lines vary for both components, while the velocities do not change. We reproduce all of the spectral data by assuming that only the ionization state of the absorbing gas is variable and that all other physical properties are invariable. The variation of ionization is consistent with the variation of optical continuum from the V -band light curve. Additionally, we cannot interpret the data by assuming that the variability is due to a movement of the absorbing gas. Therefore, our analysis strongly indicates that the absorption-line variability in LBQS 1206+1052 is photoionization driven. As shown from photoionization simulations, the absorbing gas with blueshift velocity of ∼700 km s{sup −1} has a density in the range of 10{sup 9} to 10{sup 10} cm{sup −3} and a distance of ∼1 pc, and the gas with blueshift velocity of ∼1400 km s{sup −1} has a density of 10{sup 3} cm{sup −3} and a distance of ∼1 kpc.

  9. Study of a high power hydrogen beam diagnostic based on secondary electron emission

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Department of Management and Engineering, University di Padova strad. S. Nicola 3, 36100 Vicenza (Italy); Panasenkov, A. [NRC, Kurchatov Institute, 1, Kurchatov Sq, Moscow 123182 (Russian Federation); Veltri, P. [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); INFN-LNL, viale dell’Università n. 2, 35020 Legnaro (Italy); Serianni, G.; Pasqualotto, R. [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy)

    2016-11-15

    In high power neutral beams for fusion, beam uniformity is an important figure of merit. Knowing the transverse power profile is essential during the initial phases of beam source operation, such as those expected for the ITER heating neutral beam (HNB) test facility. To measure it a diagnostic technique is proposed, based on the collection of secondary electrons generated by beam-surface and beam-gas interactions, by an array of positively biased collectors placed behind the calorimeter tubes. This measurement showed in the IREK test stand good proportionality to the primary beam current. To investigate the diagnostic performances in different conditions, we developed a numerical model of secondary electron emission, induced by beam particle impact on the copper tubes, and reproducing the cascade of secondary emission caused by successive electron impacts. The model is first validated against IREK measurements. It is then applied to the HNB case, to assess the locality of the measurement, the proportionality to the beam current density, and the influence of beam plasma.

  10. Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, M. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); BME NTI, Budapest (Hungary); Anda, G.; Réfy, D.; Zoletnik, S. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); Czopf, A.; Erdei, G. [Department of Atomic Physics, BME IOP, Budapest (Hungary); Guszejnov, D.; Kovácsik, Á.; Pokol, G. I. [BME NTI, Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-07-15

    A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera’s measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties.

  11. VUV emission spectroscopy diagnostics of a 14 GHz ECR negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, R., E-mail: duo0364@mail4.doshisha.ac.jp; Ichikawa, T.; Kasuya, T.; Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan); Nishiura, M. [Graduate School of Frontier Sciences The University of Tokyo, Kashiwara, Chiba 277-8561 (Japan); Shimozuma, T. [National lnstitute for Fusion Science, Toki, Gifu 509-5292 (Japan)

    2015-04-08

    Vacuum Ultra Violet(VUV) emission from a 4 cm diameter 2 cm long compact ion source excited by 14 GHz microwave has been investigated. Intensity ratio of band spectrum emission near Ly-α to Ly-α line spectrum is determined from the measured spectrum. which shows preferential excitation of molecules near the entrance of microwave input power. The ratio does not depend strongly upon pressure nor the input microwave power when the intensity is integrated over the volume of the plasma. The spatial distribution of the spectrum intensity ratio exhibits concentrations near microwave inlet and the opposite side where the microwave matching structure is located. The ratio at these peripheral regions is about two times as high as that of the central region. The ratio increased in proportion to the ion source pressure up to about 3.0 Pa, indicating efficient production of high energy electrons by ECR up to this pressure.

  12. Origins of visible-light emissions in hydrogen-coated silicon nanocrystals: Role of passivating coating

    International Nuclear Information System (INIS)

    Tit, Nacir; Yamani, Z.H.; Graham, J.; Ayesh, A.

    2010-01-01

    We present a theoretical investigation of the electronic and optical properties of hydrogen-coated silicon nanocrystals (Si:H NCs). On one hand, the density-functional theory (DFT) is used to both calculate the total energy and relax the NCs. On a second hand, the tight-binding method, which includes the minimal sp 3 -basis set within the second-nearest-neighbor interaction scheme, is applied to calculate the electronic structures, oscillator strength (OS) and recombination rate (RR) versus the NC size, coating and atomic relaxation. Three main findings are reported: (i) The quantum confinement in these NCs do follow similar rule to the case of a single-particle in a box, where the confinement energy decays in power-law with the increasing NC's size. (ii) The coating is shown to play the essential role in creation of large band-gap energy lying within the visible-light energy spectrum. (iii) The surface atomic relaxation is found to reduce the band-gap energy by about 150 meV and enhance both OS and RR. Our claims are corroborated by the available experimental data.

  13. Anomaly in the P- and R- branches in the spectra of hydrogen Fulcher band emission

    International Nuclear Information System (INIS)

    Kado, Shinichiro; Yamasaki, Daisuke; Iida, Yohei; Xiao Bingjia

    2004-01-01

    Anomalies in the Fulcher-band (d 3 Π u -a 3 Σ g + ) spectra, which are widely used for the purpose of measuring ro-vibronic structure of the hydrogen molecule, are investigated using the hollow cathode glow discharge of 230 V-70 mA at 30 Pa. By making use of the recently developed analyzing scheme and experimentally determined life-time of the state involved, the historical data in the Ginsburg and Dieke's publication are reanalyzed and compared with our present data. Populations of the vibronic state v' ≥ 4 in the Q branch can be corrected to a considerable extend by taking into account the lifetime of the states, while those of any v' in the P and R branches cannot. However, the average values of the upper-Fulcher populations deduced from the P and R branches coincide with those from Q branch by taking into consideration the difference in the excitation from the ground electronic state. (author)

  14. Cross-correlation cosmography with intensity mapping of the neutral hydrogen 21 cm emission

    Science.gov (United States)

    Pourtsidou, A.; Bacon, D.; Crittenden, R.

    2015-11-01

    The cross-correlation of a foreground density field with two different background convergence fields can be used to measure cosmographic distance ratios and constrain dark energy parameters. We investigate the possibility of performing such measurements using a combination of optical galaxy surveys and neutral hydrogen (HI) intensity mapping surveys, with emphasis on the performance of the planned Square Kilometre Array (SKA). Using HI intensity mapping to probe the foreground density tracer field and/or the background source fields has the advantage of excellent redshift resolution and a longer lever arm achieved by using the lensing signal from high redshift background sources. Our results show that, for our best SKA-optical configuration of surveys, a constant equation of state for dark energy can be constrained to ≃8 % for a sky coverage fsky=0.5 and assuming a σ (ΩDE)=0.03 prior for the dark energy density parameter. We also show that using the cosmic microwave background as the second source plane is not competitive, even when considering a COrE-like satellite.

  15. Hydrogen emissions and their effects on the arctic ozone losses. Risk analysis of a global hydrogen economy; Wasserstoff-Emissionen und ihre Auswirkungen auf den arktischen Ozonverlust. Risikoanalyse einer globalen Wasserstoffwirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Feck, Thomas

    2009-07-01

    Hydrogen (H{sub 2}) could be used as one of the major components in our future energy supply in an effort to avoid greenhouse gas emissions. ''Green'' hydrogen in particular, which is produced from renewable energy sources, should significantly reduce emissions that damage the climate. Despite this basically environmentally-friendly property, however, the complex chain of interactions of hydrogen with other compounds means that the implications for the atmosphere must be analysed in detail. For example, H{sub 2} emissions, which could increase the tropospheric H{sub 2} inventory, can be released throughout the complete hydrogen process chain. H{sub 2} enters the stratosphere via the tropical tropopause and is oxidised there to form water vapour (H{sub 2}O). This extra water vapour causes increased radiation in the infrared region of the electromagnetic spectrum and thus causes the stratosphere to cool down. Both the increase in H{sub 2}O and the resulting cooling down of the stratosphere encourage the formation of polar stratospheric clouds (PSC) and liquid sulphate aerosols, which facilitate the production of reactive chlorine, which in turn currently leads to dramatic ozone depletion in the polar stratosphere. In the future, H{sub 2} emissions from a global hydrogen economy could therefore encourage stratospheric ozone depletion in the polar regions and thus inhibit the ozone layer in recovering from the damage caused by chlorofluorocarbons (CFCs). In addition to estimating possible influences on the trace gas composition of the stratosphere, one of the main aims of this thesis is to evaluate the risk associated with increased polar ozone depletion caused by additional H{sub 2} emissions. Studies reported on here have shown that even if around 90% of today's fossil primary energy input was to be replaced by hydrogen and if around 9.5% of the gas was to escape in a ''worst-case'' scenario, the additional ozone loss for unchanged CFC loading in the stratosphere

  16. Hydrogen emissions and their effects on the arctic ozone losses. Risk analysis of a global hydrogen economy; Wasserstoff-Emissionen und ihre Auswirkungen auf den arktischen Ozonverlust. Risikoanalyse einer globalen Wasserstoffwirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Feck, Thomas

    2009-07-01

    Hydrogen (H{sub 2}) could be used as one of the major components in our future energy supply in an effort to avoid greenhouse gas emissions. ''Green'' hydrogen in particular, which is produced from renewable energy sources, should significantly reduce emissions that damage the climate. Despite this basically environmentally-friendly property, however, the complex chain of interactions of hydrogen with other compounds means that the implications for the atmosphere must be analysed in detail. For example, H{sub 2} emissions, which could increase the tropospheric H{sub 2} inventory, can be released throughout the complete hydrogen process chain. H{sub 2} enters the stratosphere via the tropical tropopause and is oxidised there to form water vapour (H{sub 2}O). This extra water vapour causes increased radiation in the infrared region of the electromagnetic spectrum and thus causes the stratosphere to cool down. Both the increase in H{sub 2}O and the resulting cooling down of the stratosphere encourage the formation of polar stratospheric clouds (PSC) and liquid sulphate aerosols, which facilitate the production of reactive chlorine, which in turn currently leads to dramatic ozone depletion in the polar stratosphere. In the future, H{sub 2} emissions from a global hydrogen economy could therefore encourage stratospheric ozone depletion in the polar regions and thus inhibit the ozone layer in recovering from the damage caused by chlorofluorocarbons (CFCs). In addition to estimating possible influences on the trace gas composition of the stratosphere, one of the main aims of this thesis is to evaluate the risk associated with increased polar ozone depletion caused by additional H{sub 2} emissions. Studies reported on here have shown that even if around 90% of today's fossil primary energy input was to be replaced by hydrogen and if around 9.5% of the gas was to escape in a ''worst-case'' scenario, the additional ozone loss for

  17. The hydrogen-poor superluminous supernova iPTF 13ajg and its host galaxy in absorption and emission

    Energy Technology Data Exchange (ETDEWEB)

    Vreeswijk, Paul M.; Gal-Yam, Avishay; De Cia, Annalisa; Rubin, Adam; Yaron, Ofer; Tal, David; Ofek, Eran O. [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Savaglio, Sandra [Max Planck Institute for Extraterrestrial Physics, D-85748 Garching bei München (Germany); Quimby, Robert M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Cenko, S. Bradley; Filippenko, Alexei V.; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Perley, Daniel A.; Cao, Yi [Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos [Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova 10691 Stockholm (Sweden); Arcavi, Iair [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Kasliwal, Mansi M., E-mail: paul.vreeswijk@weizmann.ac.il [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2014-12-10

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M {sub u,} {sub AB} = –22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 10{sup 44} erg s{sup –1}, while the estimated total radiated energy is 1.3 × 10{sup 51} erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s{sup –1}, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR{sub [O} {sub II]}<0.07M{sub ⊙}yr{sup −1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g {sub AB} ≈ 27.0 and R {sub AB} ≥ 26.0 mag, corresponding to M {sub B,} {sub Vega} ≳ –17.7 mag.

  18. Measurements of neutral hydrogen profiles on the EXTRAP-T2 reversed-field pinch from time-resolved ? line emission

    Science.gov (United States)

    Sallander, J.; Hedqvist, A.; Rachlew-Källne, E.

    1998-09-01

    The investigations of the radial distributions of 0953-4075/31/17/015/img2 emission from the EXTRAP-T2 reversed-field pinch (RFP) plasma show that the emission profile varies a lot, even during one plasma discharge. At central electron temperatures of about 150 eV it was expected that the 0953-4075/31/17/015/img2 emission should emerge from the plasma centre. In comparison, 0953-4075/31/17/015/img4 is always observed to radiate from the centre. Our measurements of 0953-4075/31/17/015/img2 emission have, however, shown that this is not always the case, the emission often comes from the plasma edge. The analysis of the measurements has led us to conclude that the edge emission comes from charge-exchange recombination with neutral hydrogen near the carbon first wall. These observations provide a way to estimate the change in neutral hydrogen density during local plasma-wall interaction.

  19. The first detection of neutral hydrogen in emission in a strong spiral lens

    Science.gov (United States)

    Lipnicky, Andrew; Chakrabarti, Sukanya; Wright, Melvyn C. H.; Blitz, Leo; Heiles, Carl; Cotton, William; Frayer, David; Blandford, Roger; Shu, Yiping; Bolton, Adam S.

    2018-05-01

    We report H I observations of eight spiral galaxies that are strongly lensing background sources. Our targets were selected from the Sloan WFC (Wide Field Camera) Edge-on Late-type Lens Survey (SWELLS) using the Arecibo, Karl G. Jansky Very Large Array, and Green Bank telescopes. We securely detect J1703+2451 at z = 0.063 with a signal-to-noise ratio of 6.7 and W50 = 79 ± 13 km s-1, obtaining the first detection of H I emission in a strong spiral lens. We measure a mass of M_{H I} = (1.77± 0.06^{+0.35}_{-0.75})× 10^9 M_{⊙} for this source. We find that this lens is a normal spiral, with observable properties that are fairly typical of spiral galaxies. For three other sources, we did not secure a detection; however, we are able to place strong constraints on the H I masses of those galaxies. The observations for four of our sources were rendered unusable due to strong radio frequency interference.

  20. Anomalous hydrogen emissions from the San Andreas fault observed at the Cienega Winery, central California

    Science.gov (United States)

    Sato, Motoaki; Sutton, A. J.; McGee, K. A.

    1984-03-01

    We began continuous monitoring of H2 concentration in soil along the San Andreas and Calaveras faults in central California in December 1980, using small H2/O2 fuel-cell sensors. Ten monitoring stations deployed to date have shown that anomalous H2 emissions take place occasionally in addition to diurnal changes. Among the ten sites, the Cienega Winery site has produced data that are characterized by very small diurnal changes, a stable baseline, and remarkably distinct spike-like H2 anomalies since its installation in July 1982. A major peak appeared on 1 10 November 1982, and another on 3 April 1983, and a medium peak on 1 November 1983. The occurrences of these peaks coincided with periods of very low seismicity within a radius of 50 km from the site. In order to methodically assess how these peaks are related to earthquakes, three H2 degassing models were examined. A plausible correlational pattern was obtained by using a model that (1) adopts a hemicircular spreading pattern of H2 along an incipient fracture plane from the hypocenter of an earthquake, (2) relies on the FeO-H2O reaction for H2 generation, and (3) relates the accumulated amount of H2 to the mass of serpentinization of underlying ophiolitic rocks; the mass was tentatively assumed to be proportional to the seismic energy of the earthquake.

  1. Effect of dietary nitrate level on enteric methane production, hydrogen emission, rumen fermentation, and nutrient digestibility in dairy cows

    DEFF Research Database (Denmark)

    Olijhoek, Dana; Hellwing, Anne Louise Frydendahl; Brask, Maike

    2016-01-01

    , microbial protein synthesis, and blood methemoglobin. In a 4 × 4 Latin square design 4 lactating Danish Holstein dairy cows fitted with rumen, duodenal, and ileal cannulas were assigned to 4 calcium ammonium nitrate addition levels: control, low, medium, and high [0, 5.3, 13.6, and 21.1 g of nitrate....../kg of dry matter (DM), respectively]. Diets were made isonitrogenous by replacing urea. Cows were fed ad libitum and, after a 6-d period of gradual introduction of nitrate, adapted to the corn-silage-based total mixed ration (forage:concentrate ratio 50:50 on DM basis) for 16 d before sampling. Digesta...... of nitrate increased hydrogen emissions (L/kg of DMI) quadratically by a factor of 2.5, 3.4, and 3.0 (as L/kg of DMI) for the low, medium, and high diets, respectively, compared with the control. Blood methemoglobin levels and nitrate concentrations in milk and urine increased with increasing nitrate intake...

  2. High-Resolution Electron-Impact Study of the Far-Ultraviolet Emission Spectrum of Molecular Hydrogen

    Science.gov (United States)

    Liu, Xian-Ming; Ahmed, Syed M.; Multari, Rosalie A.; James, Geoffrey K.; Ajello, Joseph M.

    1995-01-01

    The emission spectrum of molecular hydrogen produced by electron-impact excitation at 100 eV has been measured in the wavelength range 1140-1690 A. High-resolution, optically thin spectra (delta(lambda) = 0.136 A) of the far-ultraviolet (FUV) Lyman and Werner band systems have been obtained with a newly constructed 3 m spectrometer. Synthetic spectral intensities based on the transition probabilities calculated by Abgrall et al. are in very good agreement with experimentally observed intensities. Previous modeling that utilized Allison & Daigarno band transition probabilities with Hoenl-London factors breaks down when the transition moment has significant J dependence or when ro-vibrational coupling is significant. Ro-vibrational perturbation between upsilon = 14 of the B(sup 1)Sigma(sup +, sub u) state and upsilon = 3 of the C(sup 1)Pi(sub u) state and the rotational dependence of the transition moment in the bands of the Lyman system are examined. Complete high-resolution experimental reference FUV spectra, together with the model synthetic spectra based on the Abgrall transition probabilities, are presented. An improved calibration standard is obtained, and an accurate calibration of the 3 m spectrometer has been achieved.

  3. Secondary ion emission from metal surfaces bombarded by 0.5-10 keV protons and hydrogens

    International Nuclear Information System (INIS)

    Kitamura, Akira; Yano, Syukuro

    1978-01-01

    Secondary ion emission coefficients by bombardment of 0.5 - 10 keV protons K 11 and atomic hydrogens K 01 on copper, stainless steel, molybdenum and evaporated gold surfaces have been measured in a moderate vacuum. Results are summarized as follows; 1) There is no significant difference between K 11 and K 01 . 2) Differences in K 11 and K 11 between different samples of the same material and between the sample before baking-out and the same sample after baking-out are of the order of several tens of percent. 3) The incident particle energy E sub(max) at which K 11 and K 01 have the maximum value lies in the keV region, and increases with the target mass. According to the fact that E sub(max) differs substantially from the energy at which the elastic stopping power has the maximum value, a characteristic length l is introduced and calculated to be of the order of hundreds of A; the factor exp (-x/l) represents the degree of contribution of collision at depth x to K 11 or K 01 . (author)

  4. Implant test and acoustic emission technique used to investigate hydrogen assisted cracking in the melted zone of a welded HSLA-80 steel

    International Nuclear Information System (INIS)

    Fals, H. C.; Trevisan, R. E.

    1999-01-01

    Weld metal hydrogen assisted cracking was studied using two flux cored wire (AWS E 70T-5 and AWS E 120 T5-K4) and a mixture gas of CO 2 +5% H 2 to induce values of diffusible hydrogen in high strength low alloy steel (HSLA-80) weldments. An acoustical Emission Measurement System (AEMS) RMS voltmeter was coupled to the implant test (NF 89-100) apparatus to determine energy, amplitude and event numbers of signal. All cracks were initiated in the partially melted zone and propagated into the coarse-grained region of the heat affected zone when E 70 T5 consumable was used, and the quasi-cleavage fracture mode was predominant. When E 120 T5 K4 consumable was used the cracks propagated vertically across the fusion zone, and a mixed fracture mode was the most important. A significant relationship between acoustic emission parameters and fracture modes was found. (Author) 12 refs

  5. Vacuum ultraviolet emission spectrum measurement of a microwave-discharge hydrogen-flow lamp in several configurations: Application to photodesorption of CO ice

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.-J.; Wu, C.-Y. R. [Space Sciences Center and Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-1341 (United States); Chuang, K.-J.; Chu, C.-C.; Yih, T.-S. [Department of Physics, National Central University, Jhongli City, Taoyuan County 32054, Taiwan (China); Muñoz Caro, G. M. [Centro de Astrobiología, INTA-CSIC, Torrejón de Ardoz, E-28850 Madrid (Spain); Nuevo, M. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ip, W.-H., E-mail: yujung@usc.edu [Graduate Institute of Astronomy, National Central University, Jhongli City, Taoyuan County 32049, Taiwan (China)

    2014-01-20

    We report measurements of the vacuum ultraviolet (VUV) emission spectra of a microwave-discharge hydrogen-flow lamp (MDHL), a common tool in astrochemistry laboratories working on ice VUV photoprocessing. The MDHL provides hydrogen Ly-α (121.6 nm) and H{sub 2} molecular emission in the 110-180 nm range. We show that the spectral characteristics of the VUV light emitted in this range, in particular the relative proportion of Ly-α to molecular emission bands, strongly depend on the pressure of H{sub 2} inside the lamp, the lamp geometry (F type versus T type), the gas used (pure H{sub 2} versus H{sub 2} seeded in He), and the optical properties of the window used (MgF{sub 2} versus CaF{sub 2}). These different configurations are used to study the VUV irradiation of CO ice at 14 K. In contrast to the majority of studies dedicated to the VUV irradiation of astrophysical ice analogs, which have not taken into consideration the emission spectrum of the MDHL, our results show that the processes induced by photons in CO ice from a broad energy range are different and more complex than the sum of individual processes induced by monochromatic sources spanning the same energy range, as a result of the existence of multistate electronic transitions and discrepancy in absorption cross sections between parent molecules and products in the Ly-α and H{sub 2} molecular emission ranges.

  6. Vacuum ultraviolet emission spectrum measurement of a microwave-discharge hydrogen-flow lamp in several configurations: Application to photodesorption of CO ice

    International Nuclear Information System (INIS)

    Chen, Y.-J.; Wu, C.-Y. R.; Chuang, K.-J.; Chu, C.-C.; Yih, T.-S.; Muñoz Caro, G. M.; Nuevo, M.; Ip, W.-H.

    2014-01-01

    We report measurements of the vacuum ultraviolet (VUV) emission spectra of a microwave-discharge hydrogen-flow lamp (MDHL), a common tool in astrochemistry laboratories working on ice VUV photoprocessing. The MDHL provides hydrogen Ly-α (121.6 nm) and H 2 molecular emission in the 110-180 nm range. We show that the spectral characteristics of the VUV light emitted in this range, in particular the relative proportion of Ly-α to molecular emission bands, strongly depend on the pressure of H 2 inside the lamp, the lamp geometry (F type versus T type), the gas used (pure H 2 versus H 2 seeded in He), and the optical properties of the window used (MgF 2 versus CaF 2 ). These different configurations are used to study the VUV irradiation of CO ice at 14 K. In contrast to the majority of studies dedicated to the VUV irradiation of astrophysical ice analogs, which have not taken into consideration the emission spectrum of the MDHL, our results show that the processes induced by photons in CO ice from a broad energy range are different and more complex than the sum of individual processes induced by monochromatic sources spanning the same energy range, as a result of the existence of multistate electronic transitions and discrepancy in absorption cross sections between parent molecules and products in the Ly-α and H 2 molecular emission ranges.

  7. INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

    Directory of Open Access Journals (Sweden)

    Alfredas Rimkus

    2016-09-01

    Full Text Available In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume gasoline mixtures and additionally supplied oxygen and hydrogen (HHO gas mixture (3.6 l/min in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during combustion phase and decreases effective specific fuel consumption. Buthanol addition decreases the rate of heat release, the combustion temperature and pressure are lower which have an influence on lower nitrous oxide (NOx emission in exhaust gases. Buthanol lowers hydrocarbon (HC formation, but it increases carbon monoxide (CO concentration and fuel consumption. Combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced buthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved when engine is working with optimal spark timing, as it would work on gasoline fuel.

  8. New results on strong-interaction effects in antiprotonic hydrogen

    CERN Document Server

    Gotta, D; Augsburger, M A; Borchert, G L; Castelli, C M; Chatellard, D; El-Khoury, P; Egger, J P; Gorke, H; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the low-energy antiproton ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using charge-coupled devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (33 refs).

  9. New results on strong-interaction effects in antiprotonic hydrogen

    International Nuclear Information System (INIS)

    Anagnostopoulos, D. F.; Augsburger, M.; Borchert, G.; Castelli, C.; Chatellard, D.; El-Khoury, P.; Egger, J.-P.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O. W. B.; Siems, Th.; Simons, L. M.

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the Low-Energy Antiproton Ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using Charge-Coupled Devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction

  10. A national inventory of greenhouse gas (GHG), criteria air contaminants (CAC) and hydrogen sulphide (H2S) emissions by the upstream oil and gas industry : volume 1, overview of the GHG emissions inventory : technical report

    International Nuclear Information System (INIS)

    2004-09-01

    A detailed inventory of greenhouse gas (GHG) emissions from the upstream oil and gas sector in Canada was presented along with explanations of the methodologies and data sources used. This report is based on previous work done on methane and volatile organic compound emissions from the upstream oil and gas sector for the period of 1990 to 1995, but it includes key improvements in identifying primary types of emissions sources such as emissions from fuel combustion, flaring, venting, fugitive equipment leaks and accidental releases. It also includes criteria air contaminants and hydrogen sulfide emissions, an analysis of GHG emission intensities and a change in the definition of volatile organic compounds from comprising all non-methane hydrocarbons to comprising all non-methane and non-ethane hydrocarbons. The report covers portions of the upstream oil and gas industry in Canada plus the natural gas transmission and natural gas distribution industries with reference to well drilling, oil production, and natural gas production, processing, transmission and distribution. Accidents and equipment failures are also included. The report reveals the total GHG emissions by source type, sub-sector, facility type and sub-type for the year 2000 at the national level. In 2000, the total carbon dioxide equivalent GHG emissions from the entire oil and gas sector were 101,211 kilo tonnes. For the upstream oil and gas sector alone, total GHG emissions were 84,355 kilo tonnes, representing 12 per cent of Canada's total national emissions of GHGs in 2000. This is an increase of about 25 per cent from 1995 levels. The biggest primary source of these emissions is fuel combustion, which accounts for 40.8 per cent of the total. This report also includes a provincial breakdown of GHG emissions for the natural gas transmission, storage and distribution sub-sectors in Canada for the year 2000. refs., tabs., figs

  11. A NEW SUB-PERIOD-MINIMUM CATACLYSMIC VARIABLE WITH PARTIAL HYDROGEN DEPLETION AND EVIDENCE OF SPIRAL DISK STRUCTURE

    International Nuclear Information System (INIS)

    Littlefield, C.; Garnavich, P.; Magno, K.; Applegate, A.; Pogge, R.; Irwin, J.; Marion, G. H.; Kirshner, R.; Vinkó, J.

    2013-01-01

    We present time-resolved spectroscopy and photometry of CSS 120422:111127+571239 (=SBS 1108+574), a recently discovered SU UMa-type dwarf nova whose 55 minute orbital period is well below the cataclysmic variable (CV) period minimum of ∼78 minutes. In contrast with most other known CVs, its spectrum features He I emission of comparable strength to the Balmer lines, implying a hydrogen abundance less than 0.1 of long-period CVs—but still at least 10 times higher than that in AM CVn stars. Together, the short orbital period and remarkable helium-to-hydrogen ratio suggest that mass transfer in CSS 120422 began near the end of the donor star's main-sequence lifetime, meaning that this CV is a strong candidate progenitor of an AM CVn system as described by Podsiadlowski et al. Moreover, a Doppler tomogram of the Hα line reveals two distinct regions of enhanced emission. While one is the result of the stream-disk impact, the other is probably attributable to spiral disk structure generated when material in the outer disk achieves a 2:1 orbital resonance with respect to the donor.

  12. On the Origin of the Flare Emission in IRIS' SJI 2832 Filter: Balmer Continuum or Spectral Lines?

    Czech Academy of Sciences Publication Activity Database

    Kleint, L.; Heinzel, Petr; Krucker, S.

    2017-01-01

    Roč. 837, č. 2 (2017), 160/1-160/7 ISSN 0004-637X R&D Projects: GA ČR(CZ) GA16-18495S Institutional support: RVO:67985815 Keywords : Sun * chromosphere * flares Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

  13. Study of the cathodic region of a hydrogen luminescent discharge: spectroscopic diagnoses

    International Nuclear Information System (INIS)

    Barbeau, Claude

    1991-01-01

    This research thesis addresses the study of the cathodic region of a hydrogen luminescent discharge in direct current, and belongs to the field of studies on plasma-surface interactions, notably in order to understand and optimise electric discharges in H_2CH_4 mixtures used for steel cementation and hard carbon deposition. The author first presents the main characteristics of the abnormal discharge, and details operation conditions as well as the characteristics of the different experimental assemblies. The experimental study of the cathodic region has been mainly performed by high resolution emission spectroscopy, and multi-photon laser spectroscopy (laser-induced fluorescence, optogalvanic effect). In the second part, the author reports an analysis of the Doppler broadening of emission profiles of atomic lines (notably the Balmer series). Experimental results are compared with those of Monte Carlo simulation which addresses mechanisms of creation of excited atoms as well as their energetic distribution. The next parts report the development of methods and techniques for the measurement of the electric field of the cathodic drop and of gas temperature, experimental results and their interpretation [fr

  14. Characteristics of 1.9 μm laser emission from hydrogen-filled hollow-core fiber by stimulated Raman scattering

    Science.gov (United States)

    Gu, Bo; Chen, Yubin; Wang, Zefeng

    2016-11-01

    We report here the detailed characteristics of 1.9 μm laser emission from hydrogen-filled hollow-core fiber by stimulated Raman scattering. A 6.5 m hydrogen-filled Ice-cream negative curvature hollow-core fiber is pumped with a high peak power, narrow linewidth, liner polarized subnanosecond pulsed 1064 nm microchip laser, generating pulsed 1908.5 nm vibrational Stokes wave. The linewidth of the pump laser and the vibrational Stokes wave is about 1 GHz and 2 GHz respectively. And the maximum Raman conversion quantum efficiency is about 48%. We also studied the pulse shapes of the pump laser and the vibrational Stokes wave. The polarization dependence of the vibrational and the rotational stimulated Raman scattering is also investigated. In addition, the beam profile of vibrational Stokes wave shows good quality, which may be taken advantage of in many applications.

  15. The absorption effect of the Lα-line Supplement to the paper 'On the Correlation Between the Hα-line emission rate and the ablation rate of a hydrogen pellet in tokamak discharges' – Nuclear Fusion 24 (1984) 697

    DEFF Research Database (Denmark)

    Chang, C. T.; Thomsen, Kenneth

    1985-01-01

    Several assumptions made in a previous study of the correlation between the Hα-line emission rate and the ablation rate of a hydrogen pellet injected into a tokamak discharge showed that the emission layer of the ablatant as optically thin with respect to all levels of the principal quantum numbe...

  16. Kinetics of hydrogen in chromospheres of red dwarfs

    International Nuclear Information System (INIS)

    Bruevich, E.A.; Katsova, M.M.; Livshits, M.A.; AN SSSR, Moscow

    1990-01-01

    A method is suggested and solution is conducted of the stationary equations for an 8-level hydrogen atom with an approximate account for lines radiative transfer in an optically thick layer. Ionization and excitation of hydrogen atoms are caused by electron collisions; the influence of photospheric radiation was neglected. The medium stays motionless, and the photon escape from the layer is connected with gradual diffusion in frequency during multiple scatterings. Mean over the layer probabilities of photon escape are introduced into the stationary equations. They are determined for a finite-thickness layer with an uniform distribution of primary photon sources and with an absorption coefficient accounting for Stark and Doppler effects. As an example of application of the calculations, an interpretation is presented of the data on the Balmer decrement in the maximum of the stellar flare of YZ CMi on March 4, 1985. It is shown that the transition from a steep Balmer decrement to a mildly sloping one is due to a decrease of the photon escape probability in the higher members of Balmer series, i.e. the lines later than H γ

  17. Measurement of Anomalously Strong Emission from the 1s-9p Transition in the Spectrum of H-like Phosphorus Following Charge Exchange with Molecular Hydrogen

    Science.gov (United States)

    Leutenegger, M. A.; Beiersdorfer, P.; Brown, G. V.; Kelley, R. L.; Porter, F. S.

    2010-01-01

    We have measured K-shell x-ray spectra of highly ionized argon and phosphorus following charge exchange with molecular hydrogen at low collision energy in an electron beam ion trap using an x-ray calorimeter array with approx.6 eV resolution. We find that the emission at the high-end of the Lyman series is greater by a factor of two for phosphorus than for argon, even though the measurement was performed concurrently and the atomic numbers are similar. This does not agree with current theoretical models and deviates from the trend observed in previous measurements.

  18. Proton emission from thin hydrogenated targets irradiated by laser pulses at 10.sup.16./sup. W/cm.sup.2./sup

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Giuffrida, L.; Cutroneo, M.; Cirrone, P.; Picciotto, A.; Krása, Josef; Margarone, Daniele; Velyhan, Andriy; Láska, Leoš; Ullschmied, Jiří; Wolowski, J.; Badziak, J.; Rosinski, M.

    2012-01-01

    Roč. 83, č. 2 (2012), "02B315-1"-"02B315-4" ISSN 0034-6748 R&D Projects: GA MŠk(CZ) 7E09092; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : harmonics * hydrogenation * iodine * ion emission * laser beam effects * plasma materials processing * proton production * semiconductor counters Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.602, year: 2012

  19. FFM Applications to Dense and Warm Hydrogen Plasma Study

    International Nuclear Information System (INIS)

    Calisti, A.; Talin, B.; Bureyeva, L. A.; Lisitsa, V. S.; Shuvaev, D.

    2006-01-01

    A study of hydrogen lines emitted in dense and low temperature plasmas is presented. A transition from impact to quasi-static broadening for electrons is analyzed with the help of the Frequency Fluctuation Model (FFM). Electron broadening of Balmer series lines is studied for different densities and temperatures spanning a wide domain from impact to quasi-static limit. It is shown that electronic broadening makes a transition from impact to quasi-static limit depending on plasma conditions and principal quantum number. Even for the Balmer alpha line, at a density equals 1018 cm-3 and a temperature equals 1 eV, this transition occurs both in the wings and the core of the line

  20. Study by optical spectroscopy of the interaction between a hydrogen multi-polar plasma and a gallium arsenide surface

    International Nuclear Information System (INIS)

    Ferdinand, Robin

    1990-01-01

    The objective of this research thesis has been to understand which are the involved species during the deoxidation-passivation stage of the processing of gallium arsenide platelets used in semiconductor industry. The author describes problems related to the presence of oxides, and highlights the benefit of using a hydrogen multi-polar plasma to softly remove surface oxides. The experimental set-up is notably characterised by the role of magnetic confinement and its influence on plasma. A theoretical model is then developed for a better understanding of chemical and physical-chemical reactions occurring in the hydrogen plasma. Based on the use of the Boltzmann equation, the model calculates the electron energy distribution function, and allows the follow-up of species present in the plasma with respect to available and accessible parameters (pressure, discharge current, discharge voltage). A spectroscopic study of the hydrogen plasma is then reported, and the numerical model is validated by interpreting line shapes of the hydrogen Balmer series. A second experimental approach, based on electrostatic probes, is implemented, and the Laframboise theory is applied to this technique and allows electronic and ionic densities, and electron temperature to be determined. Experimental and numerical results are compared. All this leads to the study of the interaction of plasma with a sample, with a first step of study of a mixture plasma containing 85 per cent of hydrogen and 15 per cent of arsine, in order to get a general knowledge of emissions related to the presence of AsH 3 . Finally, interaction studies are performed by using laser-induced fluorescence and conventional space-resolved optical spectroscopy

  1. Laser-induced carbon plasma emission spectroscopic measurements on solid targets and in gas-phase optical breakdown

    International Nuclear Information System (INIS)

    Nemes, Laszlo; Keszler, Anna M.; Hornkohl, James O.; Parigger, Christian

    2005-01-01

    We report measurements of time- and spatially averaged spontaneous-emission spectra following laser-induced breakdown on a solid graphite/ambient gas interface and on solid graphite in vacuum, and also emission spectra from gas-phase optical breakdown in allene C3H4 and helium, and in CO2 and helium mixtures. These emission spectra were dominated by CII (singly ionized carbon), CIII (doubly ionized carbon), hydrogen Balmer beta (H b eta), and Swan C2 band features. Using the local thermodynamic equilibrium and thin plasma assumptions, we derived electron number density and electron temperature estimates. The former was in the 1016 cm -3 range, while the latter was found to be near 20000 K. In addition, the vibration-rotation temperature of the Swan bands of the C2 radical was determined to be between 4500 and 7000 K, using an exact theoretical model for simulating diatomic emission spectra. This temperature range is probably caused by the spatial inhomogeneity of the laser-induced plasma plume. Differences are pointed out in the role of ambient CO2 in a solid graphite target and in gas-phase breakdown plasma

  2. EXPERIMENTAL INVESTIGATIONS ON THE EFFECT OF HYDROGEN INDUCTION ON PERFORMANCE AND EMISSION BEHAVIOUR OF A SINGLE CYLINDER DIESEL ENGINE FUELLED WITH PALM OIL METHYL ESTER AND ITS BLEND WITH DIESEL

    Directory of Open Access Journals (Sweden)

    BOOPATHI D.

    2017-07-01

    Full Text Available Internal combustion engines are an integral part of our daily lives, especially in the agricultural and transportation sector. With depleting fossil fuel and increasing environmental pollution, the researchers are foraying into alternate sources for fuelling the internal combustion engine. Vegetable oils derived from plant seeds is one such solution, but using them in unmodified diesel engine leads to reduced thermal efficiency and increased smoke emissions. Hydrogen if induced in small quantities in the air intake manifold can enhance the engine performance running on biodiesel. In this work, experiments were performed to evaluate the engine performance when hydrogen was inducted in small quantities and blends of esterified palm oil and diesel was injected as pilot fuel in the conventional manner. Tests were performed on a single cylinder, 4 - stroke, water cooled, direct injection diesel engine running at constant speed of 1500 rpm under variable load conditions and varying hydrogen flow. At full load for 75D25POME (a blend of 75% diesel and 25% palm oil methyl ester by volume, the results indicated an increase in brake thermal efficiency from 29.75% with zero hydrogen flow to a maximum of 30.17% at 5lpm hydrogen flow rate. HC emission reduced from 34 to 31.5 ppm, by volume at maximum load. Whereas, CO emission reduced from 0.09 to 0.045 % by volume at maximum load. Due to higher combustion rates with hydrogen induction, NOx emission increased from 756 to 926 ppm, at maximum load.

  3. Energetic charged particle emission from hydrogen-loaded Pd and Ti cathodes and its enhancement by He-4 implantation

    Energy Technology Data Exchange (ETDEWEB)

    Lipson, A.G.; Miley, G.H. [University of Illinois at Urbana - Champaign, lL (United States); Lipson, A.G.; Lyakhov, B.F. [lnstitute of Physical Chemistry, The Russian Academy of Sciences, Moscow (Russian Federation); Roussetski, A.S. [P. N. Lebedev Physics Institute, The Russian Academy of Sciences Moscow (Russian Federation)

    2006-07-01

    In this paper, we demonstrate reproducible emissions of energetic alphas and protons appearing in an energy range where both cosmic ray interference and possible alpha emissions from contamination (e.g., radon) is assumed to be negligible. We also show that, {sup 4}He doping of Pd and Ti cathodes leads to a significant enhancement of the energetic charged particles emission (ECPE). This measurement of the emissions of energetic (MeV) particles, in a region of low background interference plus their enhancement by {sup 4}He doping provides very strong support for the existence of LENR processes in the crystalline lattice of deuterated metals. (authors)

  4. Energetic Charged Particle Emission from Hydrogen-Loaded pd and ti Cathodes and its Enhancement by He-4 Implantation

    Science.gov (United States)

    Lipson, A. G.; Miley, G. H.; Lipson, A. G.; Lyakhov, B. F.; Roussetski, A. S.

    2006-02-01

    In this paper, we demonstrate reproducible emissions of energetic alphas and protons appearing in an energy range where both cosmic ray interference and possible alpha emissions from contamination (e.g., radon) is assumed to be negligible. We also show that He4 doping of Pd and Ti cathodes leads to a significant enhancement of the energetic charged particles emission (ECPE). This measurement of the emissions of energetic (MeV) particles, in a region of low background interference plus their enhancement by He4 doping provides very strong support for the existence of LENR processes in the crystalline lattice of deuterated metals.

  5. Energetic charged particle emission from hydrogen-loaded Pd and Ti cathodes and its enhancement by He-4 implantation

    International Nuclear Information System (INIS)

    Lipson, A.G.; Miley, G.H.; Lipson, A.G.; Lyakhov, B.F.; Roussetski, A.S.

    2006-01-01

    In this paper, we demonstrate reproducible emissions of energetic alphas and protons appearing in an energy range where both cosmic ray interference and possible alpha emissions from contamination (e.g., radon) is assumed to be negligible. We also show that, 4 He doping of Pd and Ti cathodes leads to a significant enhancement of the energetic charged particles emission (ECPE). This measurement of the emissions of energetic (MeV) particles, in a region of low background interference plus their enhancement by 4 He doping provides very strong support for the existence of LENR processes in the crystalline lattice of deuterated metals. (authors)

  6. Infrared emission from galactic H II regions

    International Nuclear Information System (INIS)

    Zeilik, M. II.

    1975-01-01

    Near-infrared observations are presented of selected galactic HII regions (especially G45.5 + 0.1, G45.1 + 0.1, S88, and W3A) to infer the physical conditions of the dust responsible for the 2 to 25 micron emission. Two-component dust models are developed to match the observed characteristics of the infrared emission from HII regions. The dust, assumed to be bare and well-mixed with the gas in the ionized volume, consists of large (0.1 micron) ''silicate'' grains and small (0.2 micron) graphite grains. The ''silicates'' have their cosmic maximum abundance with respect to hydrogen, but the graphite grains are depleted by factors of 25 to 100 in mass. The Lyman-alpha radiation field predominately heats the ''silicate'' grains, which produce almost all the emission at 20 microns and most of it from 8 to 13 microns. The stellar radiation field predominately heats the graphite grains, which generate most of the emission at 3.5 and 5 microns. Roughly half of the observed 2 to 25 micron luminosity (when corrected for extinction) arises from Lyman-alpha photons and the other half from the Lyman and Balmer continua. The grains are too hot to provide significant emission in the far-infrared; this probably arises from a dust shell around the HII region. This two-component model predicts that HII regions should have smaller sizes at 3.5 and 5 microns than at 10 and 20 microns. The emissivities of fine-structure infrared lines for the regions are calculated. In the one instance where observations of such lines have been published (G29.9 - 0.0), predicted emissivities fall below those observed, especially for the 12.86-micron line of NeII. The discrepancy probably arises from an incorrect modeling of the region's ionization structure, but it might also reflect variations in elemental abundances or deficiencies in model stellar atmospheres for hot stars

  7. Material and energy balances of an integrated biological hydrogen production and purification system and their implications for its potential to reduce greenhouse gas emissions.

    Science.gov (United States)

    Fukushima, Yasuhiro; Huang, Yu-Jung; Chen, Jhen-Wei; Lin, Hung-Chun; Whang, Liang-Ming; Chu, Hsin; Lo, Young-Chong; Chang, Jo-Shu

    2011-09-01

    The materials and energy in an integrated biological hydrogen production and purification system involving hydrolysis, dark fermentation, photo fermentation, CO2 fixation and anaerobic digestion are balanced by integrating the results from multiple experiments, simulations and the literature. The findings are two fold. First, using 1000 kg rice straw as a substrate, 19.8 kg H2 and 138.0 kg CH4 are obtained. The net energy balance (NEB) and net energy ratio (NER) are -738.4 kWh and 77.8%, respectively, both of which imply an unfavorable energy production system. Opportunities to improve the performance particularly lie in the photo fermentation process. Second, greenhouse gas emissions are evaluated for various options. The results were comparable with the emission inventory of electricity generated from fossil fuels. NEB and NER under a zero-carbon-emission constraint were discussed in detail to clarify completely the implications of the energy and material balances on greenhouse gas emissions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Hydrogen and fuel cells. Energy technology without emissions and with high efficiency; Wasserstoff und Brennstoffzellen. Energietechnologie ohne Emissionen und mit hoher Effizienz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-11-15

    In what manner are the fuel cell technology, hydrogen production from renewable energy sources, and reduced CO2 emissions connected, and what are the consequences for the German state of Hessen? This document informs on the available types fo fuel cells, the role of hydrogen as a secondary energy source in the context of the future ''power-from-renewables'' scenario, electromobility and fuel cells, and the activities of the German state of Hessen in this sector (''H2BZ-Initiative Hessen''). The publication also contains important facts on power and emissions as well as exemplary projects of communities, the power industry, and private partners in Hessen. [German] Wie haengen Brennstoffzellentechnologie, Wasserstoffgewinnung durch erneuerbare Energien und die Reduzierung des CO2-Ausstosses zusammen, und welche Konsequenzen ergeben sich daraus fuer Hessen? Welche Arten von Brennstoffzellen es gibt, welche Rolle Wasserstoff als Sekundaerenergietraeger bei der Nutzung von erneuerbaren Energien in Zukunft spielen kann, was das Thema Elektromobilitaet mit der Brennstoffzelle zu tun hat, wie und warum sich das Land Hessen und die Wasserstoff- und Brennstoffzellen-Initiative Hessen - kurz H2BZ-Initiative Hessen - fuer die Akteure in diesen Branchen stark machen, erfaehrt man in diesem Dokument. Dazu findet man wichtige Fakten zum Thema Energie und Emissionen sowie beispielhafte Projekte hessischer Akteure.

  9. Pilot-scale testing of renewable biocatalyst for swine manure treatment and mitigation of odorous VOCs, ammonia and hydrogen sulfide emissions

    Science.gov (United States)

    Maurer, Devin L.; Koziel, Jacek A.; Bruning, Kelsey; Parker, David B.

    2017-02-01

    Comprehensive control of odors, hydrogen sulfide (H2S), ammonia (NH3), and greenhouse gas (GHG) emissions associated with swine production is a critical need. A pilot-scale experiment was conducted to evaluate surface-applied soybean peroxidase (SBP) and calcium peroxide (CaO2) as a manure additive to mitigate emissions of odorous volatile organic compounds (VOC) including dimethyl disulfide/methanethiol (DMDS/MT), dimethyl trisulfide, n-butyric acid, valeric acid, isovaleric acid, p-cresol, indole, and skatole. The secondary impact on emissions of NH3, H2S, and GHG was also measured. The SBP was tested at four treatments (2.28-45.7 kg/m2 manure) with CaO2 (4.2% by weight of SBP) over 137 days. Significant reductions in VOC emissions were observed: DMDS/MT (36.2%-84.7%), p-cresol (53.1%-89.5%), and skatole (63.2%-92.5%). There was a corresponding significant reduction in NH3 (14.6%-67.6%), and significant increases in the greenhouse gases CH4 (32.7%-232%) and CO2 (20.8%-124%). The remaining emissions (including N2O) were not statistically different. At a cost relative to 0.8% of a marketed hog it appears that SBP/CaO2 treatment could be a promising option at the lowest (2.28 kg/m2) treatment rate for reducing odorous gas and NH3 emissions at swine operations, and field-scale testing is warranted.

  10. Farm-scale testing of soybean peroxidase and calcium peroxide for surficial swine manure treatment and mitigation of odorous VOCs, ammonia and hydrogen sulfide emissions

    Science.gov (United States)

    Maurer, Devin L.; Koziel, Jacek A.; Bruning, Kelsey; Parker, David B.

    2017-10-01

    The swine industry, regulatory agencies, and the public are interested in farm-tested methods for controlling gaseous emissions from swine barns. In earlier lab- and pilot-scale studies, a renewable catalyst consisting of soybean peroxidase (SBP) mixed with calcium peroxide (CaO2) was found to be effective in mitigating gaseous emissions from swine manure. Thus, a farm-scale experiment was conducted at the university's 178-pig, shallow-pit, mechanically-ventilated swine barn to evaluate SBP/CaO2 as a surficial manure pit additive under field conditions. The SBP was applied once at the beginning of the 42-day experiment at an application rate of 2.28 kg m-2 with 4.2% CaO2 added by weight. Gas samples were collected from the primary barn exhaust fans. As compared to the control, significant reductions in gaseous emissions were observed for ammonia (NH3, 21.7%), hydrogen sulfide (H2S, 79.7%), n-butyric acid (37.2%), valeric acid (47.7%), isovaleric acid (39.3%), indole (31.2%), and skatole (43.5%). Emissions of dimethyl disulfide/methanethiol (DMDS/MT) increased by 30.6%. Emissions of p-cresol were reduced by 14.4% but were not statistically significant. There were no significant changes to the greenhouse gas (GHG) emissions of methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O). The total (material + labor) treatment cost was 2.62 per marketed pig, equivalent to 1.5% of the pig market price. The cost of CaO2 catalyst was ∼60% of materials cost. The cost of soybean hulls (SBP source) was 0.60 per marketed pig, i.e., only 40% of materials cost.

  11. Study of secondary electron emission from thin carbon targets with swift charged particles: heavy ions, hydrogen ions; Etude experimentale de l`emission electronique secondaire de cibles minces de carbone sous l`impact de projectiles rapides: ions lourds, ions hydrogene (atomiques, moleculaires ou sous forme d`agregats)

    Energy Technology Data Exchange (ETDEWEB)

    Billebaud, A

    1995-07-12

    The main subject of this work is the study of electron emission from the two surfaces of thin solid targets bombarded with swift charged particles. The slowing down of swift ions in matter is mainly due to inelastic interaction with target electrons (ionization, excitation): the energy transfer to target electrons is responsible for the secondary electron emission process. The phenomenological and theoretical descriptions of this phenomena are the subject of the first chapter. We focused on secondary electron emission induced by different kind of projectiles on thin carbon foils. In chapter two we describe hydrogen cluster induced electron emission measurement between 40 and 120 keV/proton. These projectiles, composed of several atoms, allowed us to study and highlight collective effects of the electron emission process. We extended our study of electron emission to molecular (H{sub 2}{sup +}, H{sub 3}{sup +}) and composite (H{sup -}, H{sup 0}) projectiles at higher energies (<= 2 MeV): we have designed an experimental set-up devoted to electron emission statistics measurements which allowed us to study, among others things, the role of projectile electrons in secondary electron emission. This experiment is described in the third chapter. Finally, the fourth chapter describes new measurements of electron emission induced by energetic (13 MeV/u) and highly charged argon ion provided by the medium energy beam line (SME) of GANIL (Caen), which have been analyzed in the framework of a semi-empirical model of secondary electron emission. This set of experiments brings new results on composite projectile interaction with matter, and on the consequences of high energy deposition in solids. (author).

  12. An archetype hydrogen atmosphere problem

    Science.gov (United States)

    Athay, R. G.; Mihalas, D.; Shine, R. A.

    1975-01-01

    Populations for the first three bound states and the continuum of hydrogen are determined for an isothermal hydrostatic atmosphere at 20,000 K. The atmosphere is treated as optically thin in the Balmer and Paschen continua and illuminated by continuum radiation at these wavelengths with prescribed radiation temperatures. The atmosphere is optically thick in the 2-1, 3-1, 3-2 and c-1 transitions. Three stages of approximation are treated: (1) radiative detailed balance in the 2-1, 3-1 and 3-2 transitions, (2) radiative detailed balance in the 3-1 and 3-2 transitions, and (3) all transitions out of detailed balance. The solution of this problem is nontrivial and presents sufficient difficulty to have caused the failure of at least one rather standard technique. The problem is thus a good archetype against which new methods or new implementations of old methods may be tested.

  13. An archetype hydrogen atmosphere problem

    International Nuclear Information System (INIS)

    Athay, R.G.; Mihalas, D.; Shine, R.A.

    1975-01-01

    Populations for the first three bound states and the continuum of hydrogen are determined for an isothermal, hydrostatic atmosphere at 20000K. The atmosphere is treated as being optically thin in the Balmer and Paschen continua and illuminated by continuum radiation at these wavelengths with prescribed radiation temperatures. The atmosphere is optically thick in the 2-1,3-1,3-2 and c-1 transitions. Three stages of approximation are treated: (1) radiative detailed balance in the 2-1, 3-1 and 3-2 transitions, (2) radiative detailed balance in the 3-1 and 3-2 transitions, and (3) all transitions out of detailed balance. The solution of this problem is non-trivial, and presents sufficient difficulty to have caused failure of at least one rather standard technique. The problem is thus a good archetype against which new methods, or new implementations of old methods may be tested. (Auth.)

  14. 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.).

  15. Calculation of total cross sections and effective emission coefficients for B5+ collisions with ground-state and excited hydrogen

    International Nuclear Information System (INIS)

    Guzman, F; Errea, L F; Illescas, Clara; Mendez, L; Pons, B

    2010-01-01

    Classical and semiclassical calculations of nl-resolved charge exchange cross sections in B 5 + collisions with H(n i ) are performed to compute effective emission coefficients for the n = 7 → n = 6 transition in B 4 + for plasma conditions typical of the ASDEX-U tokamak. For n i = 1, the value of the emission coefficient is larger than that obtained from ADAS database by a factor of 2 at energies of 10 keV amu -1 , but no differences are found at energies above 50 keV amu -1 . For n i = 2, our calculation yields emission coefficients close to those derived from ADAS data from low to high impact energies. The emission coefficients corresponding to B 5 + + H(n i = 3) collisions are of the same order of magnitude as those for n i = 2.

  16. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter.

  17. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy.

    Science.gov (United States)

    Colon, M; Todolí, J L; Hidalgo, M; Iglesias, M

    2008-02-25

    Two new, simple and accurate methods for the determination of sulfide (S(2-)) at low levels (microgL(-1)) in aqueous samples were developed. The generation of hydrogen sulfide (H(2)S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H(2)S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H(2)S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H(2)S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5microgL(-1) to 25mgL(-1) of sulfide. Detection limits of 5microgL(-1) and 6microgL(-1) were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters.

  18. Investigation on the performance and emission parameters of dual fuel diesel engine with mixture combination of hydrogen and producer gas as secondary fuel

    Directory of Open Access Journals (Sweden)

    A. E. Dhole

    2016-06-01

    Full Text Available This study presents experimental investigation in to the effects of using mixture of producer gas and hydrogen in five different proportions as a secondary fuel with diesel as pilot fuel at wide range of load conditions in dual fuel operation of a 4 cylinder turbocharged and intercooled 62.5 kW gen-set diesel engine at constant speed of 1500 RPM. Secondary fuel Substitution is in different percentage of diesel at each load. To generate producer gas, the rice husk was used as source in the downdraft gasifier. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. It was found that of all the combinations tested, mixture combination of PG:H2=(60:40% is the most suited one at which the brake thermal efficiency is in good comparison to that of diesel operation. Decreased NOx emissions and increased CO emissions were observed for dual fuel mode for all the fuel combinations compared to diesel fuel operation.

  19. Matrix elements and transition probabilities of interaction of electromagnetic field with a hydrogen-like atom

    International Nuclear Information System (INIS)

    Rajput, B.S.

    1977-01-01

    Using the reduced expansions of second quantized electromagnetic vector potential operator in terms of irreducible representations of Pioncare group in the interaction Hamiltonian, the exact matrix elements of interaction of electromagnetic field with a hydrogenic atom have been derived and the contributions of transitions for different combinations of angular momentum quantum numbers to the transition probabilities of various lines in Lyman-, Balmer-, and Paschen-series have been computed. (author)

  20. HST-COS Observations on Hydrogen, Helium, Carbon, and Nitrogen Emission from the SN 1987A Reverse Shock

    Science.gov (United States)

    France, Kevin; McCray, Richard; Penton, Steven V.; Kirshner, Robert P.; Challis, Peter; Laming, J. Martin; Bouchet, Patrice; Chevalier, Roger; Garnavich, Peter M.; Fransson, Claes; hide

    2011-01-01

    We present the most sensitive ultraviolet observations of Supernova 1987 A to date. Imaging spectroscopy from the Hubble Space Telescope-Cosmic Origins Spectrograph shows many narrow (Delta v approximates 300 km/s) emission lines from the circumstellar ring, broad Delta v approximates 10-20 x 10(exp 3) km/s) emission lines from the reverse shock, and ultraviolet continuum emission. The high signal-to-noise ratio (>40 per resolution element) broad Ly-alpha emission is excited by soft X-ray and EUV heating of mostly neutral gas in the circumstellar ring and outer supernova debris. The ultraviolet continuum at lambda > 1350 A can be explained by H-I two-photon (2s(exp 2)S(sub 1/2)-l(exp 2)S(sub 1/2)) emission from the same region. We confirm our earlier, tentative detection of N V lambda 1240 emission from the reverse shock and present the first detections of broad He II lambda1640, C IV lambda 1550, and N IV ] lambda1486 emission lines from the reverse shock. The helium abundance in the high-velocity material is He/H = 0.14 +/- 0.06. The N V /H alpha line ratio requires partial ion-electron equilibration (T(sub e)/T(sub p) approximately equal to 0.14-0.35). We find that the N/C abundance ratio in the gas crossing the reverse shock is significantly higher than that in the circumstellar ring, a result that may be attributed to chemical stratification in the outer envelope of the supernova progenitor. The N/C abundance may have been stratified prior to the ring expUlsion, or this result may indicate continued CNO processing in the progenitor subsequent to the expUlsion of the circumstellar ring.

  1. Origin and Quenching of Novel ultraviolet and blue emission in NdGaO3: Concept of Super-Hydrogenic Dopants.

    Science.gov (United States)

    Ghosh, Siddhartha; Saha, Surajit; Liu, Zhiqi; Motapothula, M; Patra, Abhijeet; Yakovlev, Nikolai; Cai, Yao; Prakash, Saurav; Huang, Xiao Hu; Tay, Chuan Beng; Cong, Chun Xiao; Bhatt, Thirumaleshwara; Dolmanan, Surani B; Chen, Jianqiang; Lü, Weiming; Huang, Zhen; Tripathy, Sudhiranjan; Chua, Soo Jin; Yu, Ting; Asta, Mark; Ariando, A; Venkatesan, T

    2016-11-03

    In this study we report the existence of novel ultraviolet (UV) and blue emission in rare-earth based perovskite NdGaO 3 (NGO) and the systematic quench of the NGO photoluminescence (PL) by Ce doping. Study of room temperature PL was performed in both single-crystal and polycrystalline NGO (substrates and pellets) respectively. Several NGO pellets were prepared with varying Ce concentration and their room temperature PL was studied using 325 nm laser. It was found that the PL intensity shows a systematic quench with increasing Ce concentration. XPS measurements indicated that nearly 50% of Ce atoms are in the 4+ state. The PL quench was attributed to the novel concept of super hydrogenic dopant (SHD)", where each Ce 4+ ion contributes an electron which forms a super hydrogenic atom with an enhanced Bohr radius, due to the large dielectric constant of the host. Based on the critical Ce concentration for complete quenching this SHD radius was estimated to be within a range of 0.85 nm and 1.15 nm whereas the predicted theoretical value of SHD radius for NdGaO3 is ~1.01 nm.

  2. Materials towards carbon-free, emission-free and oil-free mobility: hydrogen fuel-cell vehicles--now and in the future.

    Science.gov (United States)

    Hirose, Katsuhiko

    2010-07-28

    In the past, material innovation has changed society through new material-induced technologies, adding a new value to society. In the present world, engineers and scientists are expected to invent new materials to solve the global problem of climate change. For the transport sector, the challenge for material engineers is to change the oil-based world into a sustainable world. After witnessing the recent high oil price and its adverse impact on the global economy, it is time to accelerate our efforts towards this change. Industries are tackling global energy issues such as oil and CO2, as well as local environmental problems, such as NO(x) and particulate matter. Hydrogen is the most promising candidate to provide carbon-free, emission-free and oil-free mobility. As such, engineers are working very hard to bring this technology into the real society. This paper describes recent progress of vehicle technologies, as well as hydrogen-storage technologies to extend the cruise range and ensure the easiness of refuelling and requesting material scientists to collaborate with industry to fight against global warming.

  3. Evidence for a hydrogen-sink mechanism of (+)catechin-mediated emission reduction of the ruminant greenhouse gas methane

    NARCIS (Netherlands)

    Becker, P.M.; Wikselaar, van P.G.; Franssen, M.C.R.; Vos, de C.H.; Hall, R.D.; Beekwilder, M.J.

    2014-01-01

    Methane formation in the rumen is a major cause of greenhouse gas emission. Plant secondary compounds in ruminant diets, such as essential oils, saponins and tannins, are known to affect methane production. However, their methane-lowering properties have generally been associated with undesired side

  4. 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

  5. Measurement of mesoscopic Si:P delta-doped devices fabricated by rapid STM hydrogen depassivation lithography via field-emission

    Science.gov (United States)

    Rudolph, M.; Carr, S. M.; Subramania, G.; Ten Eyck, G.; Dominguez, J.; Lilly, M. P.; Carroll, M. S.; Bussmann, E.

    2014-03-01

    Recently, a method to fabricate nanoelectronic and quantum devices has been developed that utilizes scanning tunneling microscopy (STM) to place dopants (P) into Si with deterministic atomic-precision. Dopant placement is achieved via STM hydrogen depassivation lithography (HDL). Typically HDL is performed in a low-voltage tunneling mode where electrons desorb one H at a time, which requires extremely slow scan rates. Here, we introduce a high-voltage field-emission HDL, increasing patterning scan rate by an order of magnitude. Using the field-emission mode, we fabricated several HDL-patterned Si:P delta-doped devices, including a microscale multi-terminal Hall Effect device and a nanoscale quantum point contact. Low temperature transport measurements of the Hall device reveal a dopant density of 1014 cm-2, resistance of 2 k Ω/square, and mobility of 30 cm2/Vs. The quantum point contact showed a blockaded voltage range of 80 mV, comparable to other similar devices patterned using conventional HDL. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  6. The Role of Post Flame Oxidation on the UHC Emission for Combustion of Natural Gas and Hydrogen Containing fuels

    DEFF Research Database (Denmark)

    Jensen, Torben Kvist; Schramm, Jesper

    2003-01-01

    In-cylinder post flame oxidation of unburned hydro-carbons from crevices in a lean burn spark ignition engine has been examined for natural gas and mixtures of natural gas and a hydrogen containing producer gas. For this purpose a model was developed to describe the mixing of cold unburned...... during in-cylinder post oxidation. The Arrhenius parameters were determined using the reaction mechanism, which gave the prediction of the results from the combustion reactor experiments. The investigation showed that addition of producer gas to natural gas promotes the in-cylinder post oxidation...... significantly. Furthermore it was found that the cyclic variation in the post oxidation is reduced by addition of producer gas to natural gas....

  7. Zinc-coordinated MOFs complexes regulated by hydrogen bonds: Synthesis, structure and luminescence study toward broadband white-light emission

    Science.gov (United States)

    Duan, Hui; Dan, Wenyan; Fang, Xiangdong

    2018-04-01

    Two new compounds, namely {[Zn(apc)2]·H2O}n (1) and [Zn(apc)2(H2O)2] (2), have been designed and synthesized with a multi-functional ligand 2-aminopyrimidine-5-carboxylic acid (Hapc). Both compounds were characterized by single crystal X-ray diffraction analysis (SC-XRD), elemental analysis (EA), infrared spectroscopy (IR), and thermogravimetric analysis (TG). In solid-state structures, 1 features a two-fold interpenetrating pillared-layer 3D framework with point symbol {83}2{86}, referring to tfa topology; while 2 exhibits a 3D framework based on super unit of Zn(apc)2(H2O)2 interconnected via hydrogen bonds. Furthermore, the luminescent properties of 1 and 2 were discussed.

  8. The Role of Post Flame Oxidation on the UHC Emission for Combustion of Natural Gas and Hydrogen Containing fuels

    DEFF Research Database (Denmark)

    Jensen, Torben Kvist; Schramm, Jesper

    2003-01-01

    In-cylinder post flame oxidation of unburned hydro-carbons from crevices in a lean burn spark ignition engine has been examined for natural gas and mixtures of natural gas and a hydrogen containing producer gas. For this purpose a model was developed to describe the mixing of cold unburned...... reactants from crevices and hot burned bulk gas and to describe the oxidation of the unburned fuel. The post oxidation was described by a single step chemical reaction mechanism instead of detailed chemical kinetics in order to reduce the calculation time. However, the exploited Arrhenius expressions used...... to describe the chemical reactions were deduced from a detailed reaction mechanism. Different detailed reaction mechanisms were compared with results from combustion reactor experiments. Experiments and simulations were compared at different pressures and excesses of air similar to the conditions present...

  9. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Colon, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, J.L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Hidalgo, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Iglesias, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain)], E-mail: monica.iglesias@udg.es

    2008-02-25

    Two new, simple and accurate methods for the determination of sulfide (S{sup 2-}) at low levels ({mu}g L{sup -1}) in aqueous samples were developed. The generation of hydrogen sulfide (H{sub 2}S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H{sub 2}S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669 nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H{sub 2}S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H{sub 2}S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5 {mu}g L{sup -1} to 25 mg L{sup -1} of sulfide. Detection limits of 5 {mu}g L{sup -1} and 6 {mu}g L{sup -1} were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters.

  10. 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

  11. An interpretation of hydrogen and helium line spectra of the loop prominence observed on November 3, 1973

    International Nuclear Information System (INIS)

    Kureizumi, Takeshi; Kubota, Jun; Kawaguchi, Ichiro; Tamenaga, Tatsuo; Maeda, Koichiro.

    1977-01-01

    The H sub(I), He sub(I), and He sub(II) emission lines of the loop prominence observed on November 3, 1973 in the rapidly developing phase are analyzed. The difference in widths of these lines suggests they do not originate in the same volume. The estimated T sub(e) (8000-9000 K) and n sub(e) (-- 2 x 10 12 cm -3 ) in the loop from the Balmer lines do not change appreciably with time everywhere in the loop during our observation (00 sup(h)40 sup(m)-01 sup(h)10 sup(m)UT). The degree of ionization of hydrogen is estimated to be in the range of 0.8 to 1.0. The ionizing mechanisms may be attributed to the UV radiation (lambda<=912A) from the underlying flare region. Local thermodynamic equilibrium (LTE) is approximately established in the excited levels of He sub(I), but the singlet levels are somewhat overpopulated. The UV radiation field (lambda<=504A) from the surrounding coronal condensation is estimated from microwave and X-ray flux measurements of S sub(OLRAD)9. The ionization of He sub(I) (ionization degree 0.1-0.2) is mainly controlled by UV radiation from the coronal condensation. An adequate thread structure model of the loop prominence is suggested. (auth.)

  12. Application of laser fluorescence spectroscopy by two-photon excitation into atomic hydrogen density measurement in reactive plasmas

    International Nuclear Information System (INIS)

    Kajiwara, Toshinori; Takeda, Kazuyuki; Kim, Hee Je; Park, Won Zoo; Muraoka, Katsunori; Akazaki, Masanori; Okada, Tatsuo; Maeda, Mitsuo.

    1990-01-01

    Density profiles of hydrogen atoms in reactive plasmas of hydrogen and methane gases were measured, for the first time, using the laser fluorescence spectroscopy by two-photon excitation of Lyman beta transition and observation at the Balmer alpha radiation. Absolute density determinations showed atomic densities of around 3 x 10 17 m -3 , or the degree of dissociation to be 10 -4 . Densities along the axis perpendicular to the RF electrode showed peaked profiles, which were due to the balance of atomic hydrogen production by electron impact on molecules against diffusion loss to the walls. (author)

  13. 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.

  14. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    International Nuclear Information System (INIS)

    Filippi, F.; Mostacci, A.; Palumbo, L.; Anania, M.P.; Biagioni, A.; Chiadroni, E.; Ferrario, M.; Cianchi, A.; Zigler, A.

    2016-01-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC-LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 10 16 –10 17  cm −3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  15. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    Science.gov (United States)

    Filippi, F.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Zigler, A.

    2016-09-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC_LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 1016-1017 cm-3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  16. Characterization of a direct dc-excited discharge in water by optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, Peter; Leys, Christophe [Department of Applied Physics, Ghent University, Jozef Plateaustraat 22, B-9000 Ghent (Belgium); Schram, Daan [Department of Applied Physics, Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands); Gonzalez, Manuel A [Departamento de Fisica Aplicada, Universidad de Valladolid, 47011 Valladolid (Spain); Rego, Robby [Flemish Institute of Technological Research, VITO Materials, Boeretang 200, B-2400 Mol (Belgium); Kong, Michael G [Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)], E-mail: peter.bruggeman@ugent.be

    2009-05-01

    Dc-excited discharges generated in water at the tip of a tungsten wire which is located at the orifice of a quartz capillary are investigated by time-averaged optical emission spectroscopy. Two distinctive discharge modes are observed. For small conductivities of the liquid the discharge is a streamer-like discharge in the liquid itself (liquid mode). For conductivities above typically 45 {mu}S cm{sup -1} a large vapour bubble is formed and a streamer discharge in this vapour bubble is observed (bubble mode). Plasma temperatures and electron densities are investigated for both modes. The gas temperature is estimated from the rotational temperature of N{sub 2}(C-B) and is 1600 {+-} 200 K for the bubble mode and 1900 {+-} 200 K for the liquid mode. The rotational temperature of OH(A-X) is up to 2 times larger and cannot be used as an estimate for the gas temperature. The rotational population distribution of OH(A), {nu} = 0 is also non-Boltzmann with a large overpopulation of high rotational states. This discrepancy in rotational temperatures is discussed in detail. Electron densities are obtained from the Stark broadening of the hydrogen Balmer beta line. The electron densities in the liquid mode are of the order of 10{sup 21} m{sup -3}. In the bubble mode electron densities are significantly smaller: (3-4) x 10{sup 20} m{sup -3}. These values are compared with the Stark broadening of the hydrogen alpha and gamma lines and with electron densities obtained from current density measurements. The chemical reactivities of the bubble and liquid modes are compared by means of the hydrogen peroxide production rate.

  17. Characterization of a direct dc-excited discharge in water by optical emission spectroscopy

    International Nuclear Information System (INIS)

    Bruggeman, Peter; Leys, Christophe; Schram, Daan; Gonzalez, Manuel A; Rego, Robby; Kong, Michael G

    2009-01-01

    Dc-excited discharges generated in water at the tip of a tungsten wire which is located at the orifice of a quartz capillary are investigated by time-averaged optical emission spectroscopy. Two distinctive discharge modes are observed. For small conductivities of the liquid the discharge is a streamer-like discharge in the liquid itself (liquid mode). For conductivities above typically 45 μS cm -1 a large vapour bubble is formed and a streamer discharge in this vapour bubble is observed (bubble mode). Plasma temperatures and electron densities are investigated for both modes. The gas temperature is estimated from the rotational temperature of N 2 (C-B) and is 1600 ± 200 K for the bubble mode and 1900 ± 200 K for the liquid mode. The rotational temperature of OH(A-X) is up to 2 times larger and cannot be used as an estimate for the gas temperature. The rotational population distribution of OH(A), ν = 0 is also non-Boltzmann with a large overpopulation of high rotational states. This discrepancy in rotational temperatures is discussed in detail. Electron densities are obtained from the Stark broadening of the hydrogen Balmer beta line. The electron densities in the liquid mode are of the order of 10 21 m -3 . In the bubble mode electron densities are significantly smaller: (3-4) x 10 20 m -3 . These values are compared with the Stark broadening of the hydrogen alpha and gamma lines and with electron densities obtained from current density measurements. The chemical reactivities of the bubble and liquid modes are compared by means of the hydrogen peroxide production rate.

  18. Hydrogen Fire Spectroscopy Issues Project

    Science.gov (United States)

    Youngquist, Robert C. (Compiler)

    2014-01-01

    The detection of hydrogen fires is important to the aerospace community. The National Aeronautics and Space Administration (NASA) has devoted significant effort to the development, testing, and installation of hydrogen fire detectors based on ultraviolet, near-infrared, mid-infrared, andor far-infrared flame emission bands. Yet, there is no intensity calibrated hydrogen-air flame spectrum over this range in the literature and consequently, it can be difficult to compare the merits of different radiation-based hydrogen fire detectors.

  19. Characteristics of 1.9-μm laser emission from hydrogen-filled hollow-core fiber by vibrational stimulated Raman scattering

    Science.gov (United States)

    Gu, Bo; Chen, Yubin; Wang, Zefeng

    2016-12-01

    We report here the characteristics of 1.9-μm laser emission from a gas-filled hollow-core fiber by stimulated Raman scattering (SRS). A 6.5-m hydrogen-filled ice-cream negative curvature hollow-core fiber is pumped with a high peak-power, narrow linewidth, linearly polarized subnanosecond pulsed 1064-nm microchip laser, generating a pulsed vibrational Stokes wave at 1908.5 nm. The maximum quantum efficiency of about 48% is obtained, which is mainly limited by the mode mismatch between the pump laser beam and the Stokes wave in the hollow-core fiber. The linewidths of the pump laser and the first-order vibrational Stokes wave are measured to be about 1 and 2 GHz, respectively, by a scanning Fabry-Perot interferometer. The pressure selection phenomenon of the vibrational anti-Stokes waves is also investigated. The pulse duration of the vibrational Stokes wave is recorded to be narrower than that of the pump laser. The polarization properties of the hollow-core fiber and the polarization dependence of the vibrational and the rotational SRS are also studied. The beam profile of the vibrational Stokes wave shows good quality.

  20. A study on temperature effects on hydrogen recycling and molybdenum impurity emission from a movable limiter in TRIAM-1M Tokamak

    International Nuclear Information System (INIS)

    Bhattacharyay, R.; Zushi, H.; Nakashima, K.; Shikama, T.; Sakamoto, M.; Yoshida, N.; Kado, S.; Sawada, K.; Hirooka, Y.; Nakamura, K.; Hanada, K.; Idei, H.; Hasegawa, M.; Sato, K.N.; Ogawa, M.; Takaki, O.; Sasaki, K.; Xu, H.; Kawasaki, S.; Nakashima, H.; Higashijima, A.

    2007-01-01

    In order to investigate the surface temperature effects on plasma fuel recycling and impurity release from the plasma facing components, plasma discharges have been performed under selected plasma-wall interaction (PWI) conditions in the high-field superconducting tokamak, TRIAM-1M. By moving a water-cooled molybdenum movable limiter (ML) beyond the last closed flux surface, as defined by poloidal limiters, the surface temperature profile on it is varied. Hot spots have been observed on the ML surface in such conditions. The release behaviour of fuel as well as impurity particles from the ML surface has been studied as a function of hot spot temperature (T hot ) by means of wide range spectroscopy (200-1600 nm). A critical T hot is found to be ∼2100 K above which the emission of both hydrogen and impurity particles enhances significantly. This is indicative of some thermally activated process playing an important role in PWIs between the limiter and the edge plasma. With the rise in hot spot temperature localized PWI at the ML is found to dominate the global recycling even when external fuelling is stopped

  1. Experimental and modeling study of hydrogen/syngas production and particulate emissions from a natural gas-fueled partial oxidation engine

    International Nuclear Information System (INIS)

    McMillian, Michael H.; Lawson, Seth A.

    2006-01-01

    In this study, a combustion model was first applied to conditions representing varying compression ratios and equivalence ratios to investigate engine exhaust composition from partial oxidation (POX) of natural gas in reciprocating engines. The model was experimentally validated over a range of equivalence ratios from 1.3 to 1.6 with a spark-ignited single cylinder engine fueled by natural gas. The modeling results matched well with engine gaseous emission data over the experimental range. The model was also extended to higher equivalence ratios to predict H 2 and CO production at engine conditions and stoichiometries representative of homogeneous charge compression ignition (HCCI) engine operation. Secondly, over the same experimental range of equivalence ratios, particulate samples were taken to determine both total particulate mass production (g/hph) via gravimetric measurement as well as particle size distribution and loading via a scanning mobility particle sizer (SMPS). While experiments indicate hydrogen yields up to 11% using spark ignition (SI), modeling results indicate that greater than 20% H 2 yield may be possible in HCCI operation. Over the experimental range, rich-burn particulate matter (PM) production is no greater than that from typical lean-burn operation. Finally, an energy balance was performed over the range of engine experimental operation. (author)

  2. 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

  3. 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)

  4. DUST EXTINCTION FROM BALMER DECREMENTS OF STAR-FORMING GALAXIES AT 0.75 {<=} z {<=} 1.5 WITH HUBBLE SPACE TELESCOPE/WIDE-FIELD-CAMERA 3 SPECTROSCOPY FROM THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, A.; Siana, B.; Masters, D. [Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States); Henry, A. L.; Martin, C. L. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Scarlata, C.; Bedregal, A. G. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Malkan, M.; Ross, N. R. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States); Atek, H.; Colbert, J. W. [Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States); Teplitz, H. I.; Rafelski, M. [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); McCarthy, P.; Hathi, N. P.; Dressler, A. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Bunker, A., E-mail: albertod@ucr.edu [Department of Physics, Oxford University, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom)

    2013-02-15

    Spectroscopic observations of H{alpha} and H{beta} emission lines of 128 star-forming galaxies in the redshift range 0.75 {<=} z {<=} 1.5 are presented. These data were taken with slitless spectroscopy using the G102 and G141 grisms of the Wide-Field-Camera 3 (WFC3) on board the Hubble Space Telescope as part of the WFC3 Infrared Spectroscopic Parallel survey. Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (H{alpha}/H{beta}). We present dust extinction as a function of H{alpha} luminosity (down to 3 Multiplication-Sign 10{sup 41} erg s{sup -1}), galaxy stellar mass (reaching 4 Multiplication-Sign 10{sup 8} M {sub Sun }), and rest-frame H{alpha} equivalent width. The faintest galaxies are two times fainter in H{alpha} luminosity than galaxies previously studied at z {approx} 1.5. An evolution is observed where galaxies of the same H{alpha} luminosity have lower extinction at higher redshifts, whereas no evolution is found within our error bars with stellar mass. The lower H{alpha} luminosity galaxies in our sample are found to be consistent with no dust extinction. We find an anti-correlation of the [O III] {lambda}5007/H{alpha} flux ratio as a function of luminosity where galaxies with L {sub H{alpha}} < 5 Multiplication-Sign 10{sup 41} erg s{sup -1} are brighter in [O III] {lambda}5007 than H{alpha}. This trend is evident even after extinction correction, suggesting that the increased [O III] {lambda}5007/H{alpha} ratio in low-luminosity galaxies is likely due to lower metallicity and/or higher ionization parameters.

  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. 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)

  7. 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

  8. TheoSSA - Model WD Spectra on Demand: The Impact of Ne, Na, Mg, and Iron-group Elements on the Balmer Lines

    Science.gov (United States)

    Reindl, N.; Rauch, T.

    2015-06-01

    The registered German Astrophysical Virtual Observatory (GAVO) service TheoSSA provides easy access to synthetic stellar spectra. This GAVO database contains already ten thousands of these, which were calculated with different chemical compositions of the elements H to Ni. In addition to the database, it is possible to calculate individual spectra for hot, compact stars based on the Tübingen NLTE Model-Atmosphere Package (TMAP) via the TMAW service. The TMAW models were, in the pilot phase, restricted to the elements H, He, C, N, and O. Now, TMAW is extended to additionally consider opacities from Ne, Na, and Mg. Soon, TMAW will also be able to include the opacities from the so-called iron-group elements (Ca - Ni). We describe the improvements and show the impact of Ne, Na, Mg, and iron-group elements on the Balmer lines.

  9. Non-LTE hydrogen-line formation in moving prominences

    Science.gov (United States)

    Heinzel, P.; Rompolt, B.

    1986-01-01

    The behavior of hydrogen-line brightness variations, depending on the prominence-velocity changes were investigated. By solving the NON-Local thermodynamic equilibrium (LTE) problem for hydrogen researchers determine quantitatively the effect of Doppler brightening and/or Doppler dimming (DBE, DDE) in the lines of Lyman and Balmer series. It is demonstrated that in low-density prominence plasmas, DBE in H alpha and H beta lines can reach a factor of three for velocities around 160 km/sec, while the L alpha line exhibits typical DDE. L beta brightness variations follow from a combined DBE in the H alpha and DDE in L alpha and L beta itself, providing that all relevant multilevel interlocking processes are taken into account.

  10. Study of a pulsed discharge in hydrogen using the far ultraviolet emission of an additional element: electron temperature measurement; Etude d'une decharge pulsee dans l'hydrogene a partir de l'emission dans l'ultraviolet lointain d'un element additionnel: mesure de la temperature electronique

    Energy Technology Data Exchange (ETDEWEB)

    Schwob, J L [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-06-15

    Ionization and excitation of an additional element in a pulsed annular discharge in hydrogen at low pressure (T.A.2000) are described by means of a simple coronal type analytical model. This model allows us to interpret the time variation of the intensity of spectral lines observed in the vacuum ultraviolet region. From this analysis two methods of electron temperature determination are deduced. The first method is based on the apparition time measurement of the intensity maximum for the spectral lines emitted from successive ions of the additional element (nitrogen). In the second method the electron temperature is determined from the intensity ratio of two spectral lines of an alkali-like ion. The transition couples (2s-2p, 2s-3p) and (2s-2p, 3s-3p) of C IV, N V and O VI have been used. The results obtained with these two independent methods are in good agreement. The electron temperature varies from a few electron-volts at the beginning of the discharge, to 70 eV at the time of N V emission (at 55 {mu}s), before the current maximum in the discharge (at 170 {mu}s). (author) [French] On etudie l'ionisation et l'excitation d'un element additionnel dans une decharge annulaire pulsee dans l'hydrogene sous faible pression (T.A.2000) a ralde d'un modele analytique simple du type coronal. Ce modele permet d'interpreter l'evolution de l'intensite des raies spectrales observees dans l'ultraviolet lointain. On deduit de cette etude deux methodes de determination de la temperature electronique. La premiere est basee sur la meaure des temps d'apparition des maximums d'intensite des raies emises par les ions successifs de l'element additionnel (azote). Dans la deuxieme methode la temperature est determinee a partir du rapport d'intensite des deux raies d'un ion alcalinoide. On a utilise les couples de transitions (2s-2p, 2s-3p) et (2e-2p, 3s-3p) des ions C IV, N V et 0 VI. Les resultats obtenus par ces deux voies independantes montrent un assez bon accord. La temperature

  11. 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

  12. Development of hydrogen storage technologies

    CSIR Research Space (South Africa)

    Langmi, Henrietta W

    2015-10-01

    Full Text Available The use of hydrogen to deliver energy for cars, portable devices and buildings is seen as one of the key steps to reduce greenhouse gas emissions. South Africa’s national hydrogen strategy, HySA, aims to develop and guide innovation along the value...

  13. A prediction study of the effect of hydrogen blending on the performance and pollutants emission of a four stroke spark ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Abdul-Kadim Shahad Al-Janabi, H.; Abdul-Resul Sadiq Al-Baghdadi, M. [Babylon Univ. (Iraq). Dept. of Mechanical Engineering

    1999-04-01

    Considering energy crises and pollution problems today, investigations have been concentrated on decreasing fuel consumption by using alternative fuels and on lowering the concentration of toxic components in combustion products. In the present work a quasi-dimensional model was developed to study the effect of hydrogen blending on fuel consumption and pollutant concentrations. The results of the study show that the maximum improvement in engine thermal efficiency occurs at 8% hydrogen blending. The results also show that 10% hydrogen blending reduces CO concentration by 73.8% but the NO concentration increases by 100%. However the problem of increasing NO concentration was solved by operating the engine with lean mixture. Hydrogen blending also reduces the specific fuel consumption until about 6% blending, then the effect becomes marginal. (Author)

  14. 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

  15. The spectroscopic evolution of the symbiotic star AG Draconis I. The O VI Raman, Balmer, and helium emission line variations during the outburst of 2006-2008

    Czech Academy of Sciences Publication Activity Database

    Shore, S. N.; Wahlgren, G.M.; Genovali, K.; Bernabei, S.; Koubský, Pavel; Šlechta, Miroslav; Škoda, Petr; Skopal, A.; Wolf, M.

    2010-01-01

    Roč. 510, February (2010), A70/1-A70/10 ISSN 0004-6361 Grant - others:ESA(XE) ESA- PECS Project No. 98058; Vega(SK) 2/7010/27 Institutional research plan: CEZ:AV0Z10030501 Keywords : AG Draconis * radiation mechanisms * atomic processes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.410, year: 2010

  16. Improvement of performance and reduction of pollutant emissions of a four-stroke spark ignition engine fuelled with a mixture of hydrogen and methane as a supplementary fuel to alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Al-Bagdhadi, M.A.-R.S. [University of Babylon (Iraq). College of Engineering

    2004-05-01

    Owing to the energy crisis and pollution problems of today, investigations have concentrated on decreasing fuel consumption and on lowering the concentration of toxic components in combustion products by using non-petroleum, renewable, sustainable and non-polluting fuels. While conventional energy sources such as natural gas, oil and coal are non-renewable, hydrogen and alcohol can be coupled to renewable and sustainable energy sources. The usage of a mixture of hydrogen and methane as a supplementary fuel to an alcohol-air mixture for spark ignition engines results in a considerable improvement in engine performance and in the reduction of the toxic components in exhaust gases in comparison with the conventional spark ignition gasoline engine. In tests, the gas comprising 40 per cent H, and 60 per cent CH{sub 4} by volume was added to alcohol as 0, 2, 4, 6, 8, 10 and 12 per cent by mass. Operating test results for a range of compression ratio (CR) and equivalent ratio are presented. Gasoline fuel was used as a basis for comparison. The important improvement in methane addition reduced the specific fuel consumption (s.f.c.) and CO emission of alcohol engines. The performance of the engine is enhanced when relatively small amounts of hydrogen are present with methane. This improvement in performance, which is especially pronounced at operational equivalence ratios that are much leaner than the stoichiometric value, can be attributed largely to the faster and cleaner burning characteristics of hydrogen in comparison with methane or alcohol. Moreover, the addition of hydrogen decreases the s.f.c. of the engine. The possibility of an engine power quality adjustment has also been studied. (author)

  17. Breakdown transient study of plasma distributions in a 2.45 GHz hydrogen discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cortázar, O.D., E-mail: daniel.cortazar@uclm.es [Universidad de Castilla-La Mancha, ETSII-INEI, Applied Mechanics and Projects Department, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A. [ESS Bilbao Consortium, Polígono Ugaldeguren-III Pol. A 7B, 48170-Zamudio, Vizcaya (Spain); Tarvainen, O.; Koivisto, H. [University of Jyväskylä, Department of Physics, PO Box 35 (YFL), 40500 Jyväskylä (Finland)

    2015-05-01

    Plasma distribution transients associated with the breakdown of a 2.45 GHz hydrogen discharge similar to high current microwave ion sources are studied by means of an ultra-fast frame image acquisition system in visible light range. Eight different plasma distributions have been studied by photographing the 2D projections of the discharge through a transparent plasma electrode. The temporal evolution of images in Balmer-alpha and Fulcher band wavelengths have been recorded associated to atomic and molecular excitation and ionization processes. Some unexpected plasma distributions transient behaviors during breakdown are reported.

  18. 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.)

  19. Evaluation of aluminum sulfate (alum) as a feedlot surface amendment to reduce ammonia, hydrogen sulfide, and greenhouse gas emissions from beef feedlots

    Science.gov (United States)

    Ammonia (NH3) and greenhouse gas (GHG) emissions from concentrated feeding operations are a concern. The poultry industry has successfully used aluminum sulfate (Alum) as a litter amendment to reduce NH3 emissions from poultry barns. Alum has not been eval­uated for similar uses on cattle feedlot su...

  20. 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

  1. On determination of the degree of dissociation of hydrogen in non-equilibrium plasmas by means of emission spectroscopy: II. Experimental verification

    International Nuclear Information System (INIS)

    Lavrov, B P; Lang, N; Pipa, A V; Roepcke, J

    2006-01-01

    The method of spectroscopic determination of the degree of dissociation of hydrogen in non-equilibrium plasma, proposed in our previous paper, was verified under various plasma conditions. Three different gas discharges have been used, namely: (i) a DC-arc discharge (ii) an RF discharge, f = 200 kHz and (iii) an MW discharge, f = 2.45 GHz, under pressure p = 0.3-8 mbar. Relative intensities of atomic and molecular spectroscopic lines, the H α and H β line and the (2-2)Q1 line of the Fulcher-α system, and the gas temperature were measured in a wide range of discharge conditions and used for the determination of the degree of dissociation of hydrogen. It is shown that the method leads to plausible results in the whole range of discharge conditions studied in this paper. In particular, for the first time an influence of the redistribution of the population density of excited hydrogen atoms among fine structure sublevels on values of the degree of dissociation of hydrogen obtained by the method was investigated experimentally. It is also shown, that the influence is rather significant. The assumption of Boltzmann populations of the sublevels is more appropriate than neglecting the redistribution after electron impact excitation for p > 1 mbar

  2. Molecular hydrogen (H2) combustion emissions and their isotope (D/H) signatures from domestic heaters, diesel vehicle engines, waste incinerator plants, and biomass burning

    NARCIS (Netherlands)

    Vollmer, M.K.; Walter, S.; Mohn, J.; Steinbacher, M.; Bond, S.W.; Röckmann, T.; Reimann, S.

    2012-01-01

    Molecular hydrogen (H2), its stable isotope signature ( D), and the key combustion parameters carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) were measured from various combustion processes. H2 in the exhaust of gas and oil-fired heaters and of waste incinerator plants was generally

  3. Adaptation of a radiofrequency glow discharge optical emission spectrometer (RF-GD-OES) to the analysis of light elements (carbon, nitrogen, oxygen and hydrogen) in solids: glove box integration for the analysis of nuclear samples

    International Nuclear Information System (INIS)

    Hubinois, J.-C.

    2001-01-01

    The purpose of this work is to use the radiofrequency glow discharge optical emission spectrometry in order to quantitatively determine carbon, nitrogen, oxygen and hydrogen at low concentration (in the ppm range) in nuclear materials. In this study, and before the definitive contamination of the system, works are carried out on non radioactive materials (steel, pure iron, copper and titanium). As the initial apparatus could not deliver a RF power inducing a reproducible discharge and was not adapted to the analysis of light elements: 1- The radiofrequency system had to be changed, 2- The systems controlling gaseous atmospheres had to be improved in order to obtain analytical signals stemming strictly from the sample, 3- Three discharge lamps had to be tested and compared in terms of performances, 4- The system of collection of light had to be optimized. The modifications that were brought to the initial system improved intensities and stabilities of signals which allowed lower detection limits (1000 times lower for carbon). These latter are in the ppm range for carbon and about a few tens of ppm for nitrogen and oxygen in pure irons. Calibration curves were plotted in materials presenting very different sputtering rates in order to check the existence of a 'function of analytical transfer' with the purpose of palliating the lack of reference materials certified in light elements at low concentration. Transposition of this type of function to other matrices remains to be checked. Concerning hydrogen, since no usable reference material with our technique is available, certified materials in deuterium (chosen as a surrogate for hydrogen) were studied in order to exhibit the feasibility the analysis of hydrogen. Parallel to these works, results obtained by modeling a RF discharge show that the performances of the lamp can be improved and that the optical system must be strictly adapted to the glow discharge. (author) [fr

  4. Measurement of the Antiprotonic Lyman- and Balmer X-rays of $\\overline{p}H$ and $\\overline{p}D$ Atoms at Very Low Target Pressures

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to measure the energies and intensities of the n @A 1 (Lyman) and n @A 2 (Balmer) tansitions with high accuracy in both @*H and @*D, from which the strong interaction effects of the 1s- and 2p-level can be extracted. These observables may be related to the antiproton-proton and antiproton-neutron scattering length. \\\\ \\\\ Since in these targets collisional Stark effect occurs, we will stop the antiprotons in extreme thin gaseous targets (pressure as low as 10 Torr), where no Stark effect occurs and the 2-1 transition is favoured. In order to use antiprotons with high efficiency despite of the low target density, we will trap antiprotons of a momentum of 100 MeV/c in a magnetic field of cyclotron characteristics. The antiprotons are decelerated by their energy loss in the target gas. The focusing properties of the magnetic field serve to compensate the multiple scattering and we will end up with a concentrated stopping distribution at the centre. Due to the long orbiting time, back...

  5. Carbon strategy and management in the hydrogen economy

    International Nuclear Information System (INIS)

    Snyder, C.

    2006-01-01

    Greenhouse gas (carbon) emission reduction related to the beneficial use of hydrogen is an important aspect in the development and public acceptance of a greater role for hydrogen in the economy. This presentation is an overview of potential effects of the evolving regulatory framework for carbon emissions management in Canada on hydrogen infrastructure development and compare it with activities in other jurisdictions

  6. 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.

  7. Control of hydrogen sulfide emission from geothermal power plants. Volume III. Final report: demonstration plant equipment descriptions, test plan, and operating instructions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, F.C.; Harvey, W.W.; Warren, R.B.

    1977-01-01

    The elements of the final, detailed design of the demonstration plant for the copper sulfate process for the removal of hydrogen sulfide from geothermal steam are summarized. Descriptions are given of all items of equipment in sufficient detail that they can serve as purchase specifications. The process and mechanical design criteria which were used to develop the specifications, and the process descriptions and material and energy balance bases to which the design criteria were applied are included. (MHR)

  8. Production of Hydrogen from Bio-ethanol

    International Nuclear Information System (INIS)

    Fabrice Giroudiere; Christophe Boyer; Stephane His; Robert Sanger; Kishore Doshi; Jijun Xu

    2006-01-01

    IFP and HyRadix are collaborating in the development of a new hydrogen production system from liquid feedstock such as bio-ethanol. Reducing greenhouse gas (GHG) emissions along with high hydrogen yield are the key objectives. Market application of the system will be hydrogen refueling stations as well as medium scale hydrogen consumers including the electronics, metals processing, and oils hydrogenation industries. The conversion of bio-ethanol to hydrogen will be performed within a co-developed process including an auto-thermal reformer working under pressure. The technology will produce high-purity hydrogen with ultralow CO content. The catalytic auto-thermal reforming technology combines the exothermic and endothermic reaction and leads to a highly efficient heat integration. The development strategy to reach a high hydrogen yield target with the bio-ethanol hydrogen generator is presented. (authors)

  9. 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

  10. The Norwegian hydrogen guide 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    Hydrogen technologies are maturing at rapid speed, something we experience in Norway and around the globe every day as demonstration projects for vehicles and infrastructure expand at a rate unthinkable of only a few years ago. An example of this evolution happened in Norway in 2009 when two hydrogen filling stations were opened on May the 11th, making it possible to arrange the highly successful Viking Rally from Oslo to Stavanger with more than 40 competing teams. The Viking Rally demonstrated for the public that battery and hydrogen-electric vehicles are technologies that exist today and provide a real alternative for zero emission mobility in the future. The driving range of the generation of vehicles put into demonstration today is more than 450 km on a full hydrogen tank, comparable to conventional vehicles. As the car industry develops the next generation of vehicles for serial production within the next 4-5 years, we will see vehicles that are more robust, more reliable and cost effective. Also on the hydrogen production and distribution side progress is being made, and since renewable hydrogen from biomass and electrolysis is capable of making mobility basically emission free, hydrogen can be a key component in combating climate change and reducing local emissions. The research Council of Norway has for many years supported the development of hydrogen and fuel cell technologies, and The Research Council firmly believes that hydrogen and fuel cell technologies play a crucial role in the energy system of the future. Hydrogen is a flexible transportation fuel, and offers possibilities for storing and balancing intermittent electricity in the energy system. Norwegian companies, research organisations and universities have during the last decade developed strong capabilities in hydrogen and fuel cell technologies, capabilities it is important to further develop so that Norwegian actors can supply high class hydrogen and fuel cell technologies to global markets

  11. Emissions of ammonia, carbon dioxide, and hydrogen sulfide from swine wastewater during and after acidification treatment: effect of pH, mixing and aeration

    DEFF Research Database (Denmark)

    Dai, Xiao-Rong; Blanes-Vidal, Victoria

    2013-01-01

    setup consisting of nine dynamic flux chambers. Three pH levels (pH = 6.0, pH = 5.8 and pH = 5.5), combined with short-term aeration and venting (with an inert gas) treatments were studied. Acidification reduced average NH(3) emissions from swine slurry stored after acidification treatment compared...... to emissions during storage of non-acidified slurry. The reduction were 50%, 62% and 77% when pH was reduce to 6.0, 5.8 and 5.5, respectively. However, it had no significant effect on average CO(2) and H(2)S emissions during storage of slurry after acidification. Aeration of the slurry for 30 min had no effect...

  12. 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

  13. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    Vidovic, Z.

    1997-06-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  14. Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tzu-Ting, E-mail: d89844001@ntu.edu.tw [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China); Lin, Shaw-Tao [Department of Applied Chemistry, Providence University, No. 200 Chung-Chi Rd., Salu Dist., Taichung City 43301, Taiwan (China); Lin, Tser-Sheng [Department of Safety, Health, and Environmental Engineering, National United University, 2 Lien Da, Maioli 360, Taiwan (China); Chung, Hua-Yi [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China)

    2015-02-15

    The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0 L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17–78.72 mg/g, 26,139.80–35,932.98 and 5735.22–13,431.51 ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26–83.70% and 16.30–29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82–797.76 ng/g) was approximately 6.92–25.08 times higher than that of the gaseous phase (26.27–36.07 ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO{sub 3}) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency. - Highlights: • PAHs emissions are influenced by mosquito coils containing various atomic H/C ratios. • The PAHs generated by burning mosquito coils mainly occur in the gaseous phase. • Total TEQ emission factors of PAHs mainly consisted of the particulate phase (> 87%). • The BaP and BaA accounted for 71.13–77.28% of the total TEQ emission factors. • Special PAH ratios were regarded as characteristic ratios for burning mosquito coil.

  15. Hydrogen: Fueling the Future

    International Nuclear Information System (INIS)

    Leisch, Jennifer

    2007-01-01

    As our dependence on foreign oil increases and concerns about global climate change rise, the need to develop sustainable energy technologies is becoming increasingly significant. Worldwide energy consumption is expected to double by the year 2050, as will carbon emissions along with it. This increase in emissions is a product of an ever-increasing demand for energy, and a corresponding rise in the combustion of carbon containing fossil fuels such as coal, petroleum, and natural gas. Undisputable scientific evidence indicates significant changes in the global climate have occurred in recent years. Impacts of climate change and the resulting atmospheric warming are extensive, and know no political or geographic boundaries. These far-reaching effects will be manifested as environmental, economic, socioeconomic, and geopolitical issues. Offsetting the projected increase in fossil energy use with renewable energy production will require large increases in renewable energy systems, as well as the ability to store and transport clean domestic fuels. Storage and transport of electricity generated from intermittent resources such as wind and solar is central to the widespread use of renewable energy technologies. Hydrogen created from water electrolysis is an option for energy storage and transport, and represents a pollution-free source of fuel when generated using renewable electricity. The conversion of chemical to electrical energy using fuel cells provides a high efficiency, carbon-free power source. Hydrogen serves to blur the line between stationary and mobile power applications, as it can be used as both a transportation fuel and for stationary electricity generation, with the possibility of a distributed generation energy infrastructure. Hydrogen and fuel cell technologies will be presented as possible pollution-free solutions to present and future energy concerns. Recent hydrogen-related research at SLAC in hydrogen production, fuel cell catalysis, and hydrogen

  16. 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)

  17. Hydrogen Production Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The Hydrogen Production Technical Team Roadmap identifies research pathways leading to hydrogen production technologies that produce near-zero net greenhouse gas (GHG) emissions from highly efficient and diverse renewable energy sources. This roadmap focuses on initial development of the technologies, identifies their gaps and barriers, and describes activities by various U.S. Department of Energy (DOE) offices to address the key issues and challenges.

  18. The Distribution of Hydrogen, Nitrogen, and Chlorine Radicals in the Lower Stratosphere: Implications for Changes in O3 due to Emission of NO(y) from Supersonic Aircraft

    Science.gov (United States)

    Salawitch, R. J.; Wofsy, S. C.; Wennberg, P. O.; Cohen, R. C.; Anderson, J. G.; Fahey, D. W.; Gao, R. S.; Keim, E. R.; Woodbridge, E. L.; Stimpfle, R. M.; hide

    1994-01-01

    In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained in the lower stratosphere during the Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE) are compared to results from a photochemical model that assimilates measurements of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N2O5 agree well with measured concentrations of NO and ClO, but concentrations of HO2 and OH are underestimated by 10 to 25%, concentrations of NO2 are overestimated by 10 to 30%, and concentrations of HCl are overestimated by a factor of 2. Discrepancies for [OH] and [HO2] are reduced if we allow for higher yields of O(sup 1)D) from 03 photolysis and for heterogeneous production of HNO2. The data suggest more efficient catalytic removal of O3 by hydrogen and halogen radicals relative to nitrogen oxide radicals than predicted by models using recommended rates and cross sections. Increases in [O3] in the lower stratosphere may be larger in response to inputs of NO(sub y) from supersonic aircraft than estimated by current assessment models.

  19. Solar hydrogen for urban trucks

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, J.: Scott, P.B.; Zweig, R. [Clean Air Now, Northridge, CA (United States)

    1997-12-31

    The Clean Air Now (CAN) Solar Hydrogen Project, located at Xerox Corp., El Segundo, California, includes solar photovoltaic powered hydrogen generation, compression, storage and end use. Three modified Ford Ranger trucks use the hydrogen fuel. The stand-alone electrolyzer and hydrogen dispensing system are solely powered by a photovoltaic array. A variable frequency DC-AC converter steps up the voltage to drive the 15 horsepower compressor motor. On site storage is available for up to 14,000 standard cubic feet (SCF) of solar hydrogen, and up to 80,000 SCF of commercial hydrogen. The project is 3 miles from Los Angeles International airport. The engine conversions are bored to 2.9 liter displacement and are supercharged. Performance is similar to that of the Ranger gasoline powered truck. Fuel is stored in carbon composite tanks (just behind the driver`s cab) at pressures up to 3600 psi. Truck range is 144 miles, given 3600 psi of hydrogen. The engine operates in lean burn mode, with nil CO and HC emissions. NO{sub x} emissions vary with load and rpm in the range from 10 to 100 ppm, yielding total emissions at a small fraction of the ULEV standard. Two trucks have been converted for the Xerox fleet, and one for the City of West Hollywood. A public outreach program, done in conjunction with the local public schools and the Department of Energy, introduces the local public to the advantages of hydrogen fuel technologies. The Clean Air Now program demonstrates that hydrogen powered fleet development is an appropriate, safe, and effective strategy for improvement of urban air quality, energy security and avoidance of global warming impact. Continued technology development and cost reduction promises to make such implementation market competitive.

  20. Hydrogen Production from Nuclear Energy

    Science.gov (United States)

    Walters, Leon; Wade, Dave

    2003-07-01

    During the past decade the interest in hydrogen as transportation fuel has greatly escalated. This heighten interest is partly related to concerns surrounding local and regional air pollution from the combustion of fossil fuels along with carbon dioxide emissions adding to the enhanced greenhouse effect. More recently there has been a great sensitivity to the vulnerability of our oil supply. Thus, energy security and environmental concerns have driven the interest in hydrogen as the clean and secure alternative to fossil fuels. Remarkable advances in fuel-cell technology have made hydrogen fueled transportation a near-term possibility. However, copious quantities of hydrogen must be generated in a manner independent of fossil fuels if environmental benefits and energy security are to be achieved. The renewable technologies, wind, solar, and geothermal, although important contributors, simply do not comprise the energy density required to deliver enough hydrogen to displace much of the fossil transportation fuels. Nuclear energy is the only primary energy source that can generate enough hydrogen in an energy secure and environmentally benign fashion. Methods of production of hydrogen from nuclear energy, the relative cost of hydrogen, and possible transition schemes to a nuclear-hydrogen economy will be presented.

  1. Hydrogen-enriched fuels

    Energy Technology Data Exchange (ETDEWEB)

    Roser, R. [NRG Technologies, Inc., Reno, NV (United States)

    1998-08-01

    NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventional fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.

  2. The hydrogen mine introduction initiative

    Energy Technology Data Exchange (ETDEWEB)

    Betournay, M.C.; Howell, B. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2009-07-01

    In an effort to address air quality concerns in underground mines, the mining industry is considering the use fuel cells instead of diesel to power mine production vehicles. The immediate issues and opportunities associated with fuel cells use include a reduction in harmful greenhouse gas emissions; reduction in ventilation operating costs; reduction in energy consumption; improved health benefits; automation; and high productivity. The objective of the hydrogen mine introduction initiative (HMII) is to develop and test the range of fundamental and needed operational technology, specifications and best practices for underground hydrogen power applications. Although proof of concept studies have shown high potential for fuel cell use, safety considerations must be addressed, including hydrogen behaviour in confined conditions. This presentation highlighted the issues to meet operational requirements, notably hydrogen production; delivery and storage; mine regulations; and hydrogen behaviour underground. tabs., figs.

  3. 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...

  4. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere I. Continuous Emission and Condensed Matter Within the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The continuous spectrum of the solar photosphere stands as the paramount observation with regard to the condensed nature of the solar body. Studies relative to Kirchhoff’s law of thermal emission (e.g. Robitaille P.-M. Kirchhoff’s law of thermal emission: 150 years. Progr. Phys., 2009, v. 4, 3–13. and a detailed analysis of the stellar opacity problem (Robitaille P.M. Stellar opacity: The Achilles’ heel of the gaseous Sun. Progr. Phys., 2011, v. 3, 93–99 have revealed that gaseous models remain unable to properly account for the generation of this spectrum. Therefore, it can be stated with certainty that the photosphere is comprised of condensed matter. Beyond the solar surface, the chromospheric layer of the Sun also generates a weak continuous spectrum in the visible region. This emission exposes the presence of material in the condensed state. As a result, above the level of the photosphere, matter exists in both gaseous and condensed forms, much like within the atmosphere of the Earth. The continuous visible spectrum associated with the chromosphere provides the twenty-sixth line of evidence that the Sun is condensed matter.

  5. Hydrogen production by nuclear heat

    International Nuclear Information System (INIS)

    Crosbie, Leanne M.; Chapin, Douglas

    2003-01-01

    A major shift in the way the world obtains energy is on the horizon. For a new energy carrier to enter the market, several objectives must be met. New energy carriers must meet increasing production needs, reduce global pollution emissions, be distributed for availability worldwide, be produced and used safely, and be economically sustainable during all phases of the carrier lifecycle. Many believe that hydrogen will overtake electricity as the preferred energy carrier. Hydrogen can be burned cleanly and may be used to produce electricity via fuel cells. Its use could drastically reduce global CO 2 emissions. However, as an energy carrier, hydrogen is produced with input energy from other sources. Conventional hydrogen production methods are costly and most produce carbon dioxide, therefore, negating many of the benefits of using hydrogen. With growing concerns about global pollution, alternatives to fossil-based hydrogen production are being developed around the world. Nuclear energy offers unique benefits for near-term and economically viable production of hydrogen. Three candidate technologies, all nuclear-based, are examined. These include: advanced electrolysis of water, steam reforming of methane, and the sulfur-iodine thermochemical water-splitting cycle. The underlying technology of each process, advantages and disadvantages, current status, and production cost estimates are given. (author)

  6. Integrated waste hydrogen utilization project

    International Nuclear Information System (INIS)

    Armstrong, C.

    2004-01-01

    'Full text:' The BC Hydrogen Highway's, Integrated Waste Hydrogen Utilization Project (IWHUP) is a multi-faceted, synergistic collaboration that will capture waste hydrogen and promote its use through the demonstration of 'Hydrogen Economy' enabling technologies developed by Canadian companies. IWHUP involves capturing and purifying a small portion of the 600 kg/hr of by-product hydrogen vented to the atmosphere at the ERCO's electrochemical sodium chlorate plant in North Vancouver, BC. The captured hydrogen will then be compressed so it is suitable for transportation on roadways and can be used as a fuel in transportation and stationary fuel cell demonstrations. In summary, IWHUP invests in the following; Facilities to produce up to 20kg/hr of 99.999% pure 6250psig hydrogen using QuestAir's leading edge Pressure Swing Absorption technology; Ultra high-pressure transportable hydrogen storage systems developed by Dynetek Industries, Powertech Labs and Sacre-Davey Engineering; A Mobile Hydrogen Fuelling Station to create Instant Hydrogen Infrastructure for light-duty vehicles; Natural gas and hydrogen (H-CNG) blending and compression facilities by Clean Energy for fueling heavy-duty vehicles; Ten hydrogen, internal combustion engine (H-ICE), powered light duty pick-up vehicles and a specialized vehicle training, maintenance, and emissions monitoring program with BC Hydro, GVRD and the District of North Vancouver; The demonstration of Westport's H-CNG technology for heavy-duty vehicles in conjunction with local transit properties and a specialized vehicle training, maintenance, and emissions monitoring program; The demonstration of stationary fuel cell systems that will provide clean power for reducing peak-load power demands (peak shaving), grid independence and water heating; A comprehensive communications and outreach program designed to educate stakeholders, the public, regulatory bodies and emergency response teams in the local community, Supported by industry

  7. Florida Hydrogen Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Block, David L

    2013-06-30

    monitoring at any facility engaged in transport, handling and use of hydrogen. Development of High Efficiency Low Cost Electrocatalysts for Hydrogen Production and PEM Fuel Cell Applications ? M. Rodgers, Florida Solar Energy Center The objective of this project was to decrease platinum usage in fuel cells by conducting experiments to improve catalyst activity while lowering platinum loading through pulse electrodeposition. Optimum values of several variables during electrodeposition were selected to achieve the highest electrode performance, which was related to catalyst morphology. Understanding Mechanical and Chemical Durability of Fuel Cell Membrane Electrode Assemblies ? D. Slattery, Florida Solar Energy Center The objective of this project was to increase the knowledge base of the degradation mechanisms for membranes used in proton exchange membrane fuel cells. The results show the addition of ceria (cerium oxide) has given durability improvements by reducing fluoride emissions by an order of magnitude during an accelerated durability test. Production of Low-Cost Hydrogen from Biowaste (HyBrTec?) ? R. Parker, SRT Group, Inc., Miami, FL This project developed a hydrogen bromide (HyBrTec?) process which produces hydrogen bromide from wet-cellulosic waste and co-produces carbon dioxide. Eelectrolysis dissociates hydrogen bromide producing recyclable bromine and hydrogen. A demonstration reactor and electrolysis vessel was designed, built and operated. Development of a Low-Cost and High-Efficiency 500 W Portable PEMFC System ? J. Zheng, Florida State University, H. Chen, Bing Energy, Inc. The objectives of this project were to develop a new catalyst structures comprised of highly conductive buckypaper and Pt catalyst nanoparticles coated on its surface and to demonstrate fuel cell efficiency improvement and durability and cell cost reductions in the buckypaper based electrodes. Development of an Interdisciplinary Hydrogen and Fuel Cell Technology Academic Program ? J

  8. Reconstruction of negative hydrogen ion beam properties from beamline diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Benjamin

    2014-09-25

    (BES). BES measures the beam divergence and beam power losses from heavy-particle collisions by evaluating the spectrum of the Balmer H{sub α} light of the beam. The light is emitted since beam particles are excited by collisions with the hydrogen background gas. For ITER, BES will be the main beam diagnostic tool for beam quality measurements. The main results are, that first of all, the evaluation of the beam divergence from a BES spectrum was improved with the parametrisation method. Furthermore it turned out that the evaluation of stripping losses and beam inhomogeneity in large negative hydrogen ion sources cannot be performed by backward calculations from a BES spectra, i.e. by the analysis of the spectra. This means forward modeling has to be done, which does also include the simulation of other beam diagnostic tools, like the power density profile measured by the calorimeter. Combining all beam diagnostic tools and reconstructing their outcome with a BBC-NI Advanced simulation, gives the possibility to determine the beam parameters by extracting them from the BBC-NI code protocols. This requires a lot of effort and is not well suited for a routine analysis. For ITER this means that solely a BES system for the determination of the beam parameters (i.e. stripping losses and beam inhomogeneity), as it is presently foreseen, is not sufficient. Several beam diagnostic tools, e.g. the calorimeter which can determine the power density profile of the beam, and a code like BBC-NI are necessary. Additionally for the application of BBC-NI Advanced, a beam optic code is needed, which is able to generate a realistic electric field map in the extraction system. Such an optic code is not available so far.

  9. Transition to hydrogen: pathways toward clean transportation

    National Research Council Canada - National Science Library

    Wokaun, Alexander; Wilhelm, Erik

    2011-01-01

    ..., industrial stakeholders and researchers alike. Using hydrogen as a fuel offers a possible solution to satisfying global mobility needs, including sustainability of supply and the potential reduction of greenhouse gas emissions...

  10. Determination of Hydrogen Density by Swift Heavy Ions.

    Science.gov (United States)

    Xu, Ge; Barriga-Carrasco, M D; Blazevic, A; Borovkov, B; Casas, D; Cistakov, K; Gavrilin, R; Iberler, M; Jacoby, J; Loisch, G; Morales, R; Mäder, R; Qin, S-X; Rienecker, T; Rosmej, O; Savin, S; Schönlein, A; Weyrich, K; Wiechula, J; Wieser, J; Xiao, G Q; Zhao, Y T

    2017-11-17

    A novel method to determine the total hydrogen density and, accordingly, a precise plasma temperature in a lowly ionized hydrogen plasma is described. The key to the method is to analyze the energy loss of swift heavy ions interacting with the respective bound and free electrons of the plasma. A slowly developing and lowly ionized hydrogen theta-pinch plasma is prepared. A Boltzmann plot of the hydrogen Balmer series and the Stark broadening of the H_{β} line preliminarily defines the plasma with a free electron density of (1.9±0.1)×10^{16}  cm^{-3} and a free electron temperature of 0.8-1.3 eV. The temperature uncertainty results in a wide hydrogen density, ranging from 2.3×10^{16} to 7.8×10^{18}  cm^{-3}. A 108 MHz pulsed beam of ^{48}Ca^{10+} with a velocity of 3.652  MeV/u is used as a probe to measure the total energy loss of the beam ions. Subtracting the calculated energy loss due to free electrons, the energy loss due to bound electrons is obtained, which linearly depends on the bound electron density. The total hydrogen density is thus determined as (1.9±0.7)×10^{17}  cm^{-3}, and the free electron temperature can be precisely derived as 1.01±0.04  eV. This method should prove useful in many studies, e.g., inertial confinement fusion or warm dense matter.

  11. Mixed quantum-classical molecular dynamics study of the hydroxyl stretch in methanol/carbon-tetrachloride mixtures II: excited state hydrogen bonding structure and dynamics, infrared emission spectrum, and excited state lifetime.

    Science.gov (United States)

    Kwac, Kijeong; Geva, Eitan

    2012-03-08

    We present a mixed quantum-classical molecular dynamics study of the hydrogen-bonding structure and dynamics of a vibrationally excited hydroxyl stretch in methanol/carbon-tetrachloride mixtures. The adiabatic Hamiltonian of the quantum-mechanical hydroxyl is diagonalized on-the-fly to obtain the ground and first-excited adiabatic energy levels and wave functions which depend parametrically on the instantaneous configuration of the classical degrees of freedom. The dynamics of the classical degrees of freedom are determined by Hellmann-Feynman forces obtained by taking the expectation value of the force with respect to the ground or excited vibrational wave functions. Polarizable force fields are used which were previously shown to reproduce the experimental infrared absorption spectrum rather well, for different isotopomers and over a wide composition range [Kwac, K.; Geva, E. J. Phys. Chem. B 2011, 115, 9184]. We show that the agreement of the absorption spectra with experiment can be further improved by accounting for the dependence of the dipole moment derivatives on the configuration of the classical degrees of freedom. We find that the propensity of a methanol molecule to form hydrogen bonds increases upon photoexcitation of its hydroxyl stretch, thereby leading to a sizable red-shift of the corresponding emission spectrum relative to the absorption spectrum. Treating the relaxation from the first excited to the ground state as a nonadiabatic process, and calculating its rate within the framework of Fermi's golden rule and the harmonic-Schofield quantum correction factor, we were able to predict a lifetime which is of the same order of magnitude as the experimental value. The experimental dependence of the lifetime on the transition frequency is also reproduced. Nonlinear mapping relations between the hydroxyl transition frequency and bond length in the excited state and the electric field along the hydroxyl bond axis are established. These mapping relations

  12. 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

  13. Antiprotonic-hydrogen atoms

    International Nuclear Information System (INIS)

    Batty, C.J.

    1989-07-01

    Experimental studies of antiprotonic-hydrogen atoms have recently made great progress following the commissioning of the low energy antiproton facility (LEAR) at CERN in 1983. At the same time our understanding of the atomic cascade has increased considerably through measurements of the X-ray spectra. The life history of the p-bar-p atom is considered in some detail, from the initial capture of the antiproton when stopping in hydrogen, through the atomic cascade with the emission of X-rays, to the final antiproton annihilation and production of mesons. The experiments carried out at LEAR are described and the results compared with atomic cascade calculations and predictions of strong interaction effects. (author)

  14. Comparative costs and benefits of hydrogen vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Berry, G.D. [Lawrence Livermore National Lab., CA (United States)

    1996-10-01

    The costs and benefits of hydrogen as a vehicle fuel are compared to gasoline, natural gas, and battery-powered vehicles. Costs, energy, efficiency, and tail-pipe and full fuel cycle emissions of air pollutants and greenhouse gases were estimated for hydrogen from a broad range of delivery pathways and scales: from individual vehicle refueling systems to large stations refueling 300 cars/day. Hydrogen production from natural gas, methanol, and ammonia, as well as water electrolysis based on alkaline or polymer electrolytes and steam electrolysis using solid oxide electrolytes are considered. These estimates were compared to estimates for competing fuels and vehicles, and used to construct oil use, air pollutant, and greenhouse gas emission scenarios for the U.S. passenger car fleet from 2005-2050. Fuel costs need not be an overriding concern in evaluating the suitability of hydrogen as a fuel for passenger vehicles. The combined emissions and oil import reduction benefits of hydrogen cars are estimated to be significant, valued at up to {approximately}$400/yr for each hydrogen car when primarily clean energy sources are used for hydrogen production. These benefits alone, however, become tenuous as the basis supporting a compelling rationale for hydrogen fueled vehicles, if efficient, advanced fossil-fuel hybrid electric vehicles (HEV`s) can achieve actual on-road emissions at or below ULEV standards in the 2005-2015 timeframe. It appears a robust rationale for hydrogen fuel and vehicles will need to also consider unique, strategic, and long-range benefits of hydrogen vehicles which can be achieved through the use of production, storage, delivery, and utilization methods for hydrogen which are unique among fuels: efficient use of intermittent renewable energy sources, (e,g, wind, solar), small-scale feasibility, fuel production at or near the point of use, electrolytic production, diverse storage technologies, and electrochemical conversion to electricity.

  15. A nuclear based hydrogen economy

    International Nuclear Information System (INIS)

    Sandquist, G.M.; Tamm, G.; Kunze, J.

    2005-01-01

    Exhausting demands are being imposed upon the world's ability to extract and deliver oil to the nations demanding fluid fossil fuels. This paper analyzes these issues and concludes that there must be no delay in beginning the development of the 'hydrogen economy' using nuclear energy as the primary energy source to provide both the fluid fuel and electrical power required in the 21st century. Nuclear energy is the only proven technology that is abundant and available worldwide to provide the primary energy needed to produce adequate hydrogen fluid fuel supplies to replace oil. Most importantly, this energy transition can be accomplished in an economical and technically proven manner while lowering greenhouse gas emissions. Furthermore, a similar application of using wind and solar to produce hydrogen instead of electricity for the grid can pave the way for the much larger production scales of nuclear plants producing both electricity and hydrogen. (authors)

  16. 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.

  17. Hydrogen, fuel of the future?

    International Nuclear Information System (INIS)

    Bello, B.

    2008-01-01

    The European project HyWays has drawn out the road map of hydrogen energy development in Europe. The impact of this new energy vector on the security of energy supplies, on the abatement of greenhouse gases and on the economy should be important in the future. This article summarizes the main conclusions of the HyWays study: CO 2 emissions, hydrogen production mix, oil saving abatement, economic analysis, contribution of hydrogen to the development of renewable energies, hydrogen uses, development of regional demand and of users' centers, transport and distribution. The proposals of the HyWays consortium are as follows: implementing a strong public/private European partnership to reach the goals, favoring market penetration, developing training, tax exemption on hydrogen in the initial phase for a partial compensation of the cost difference, inciting public fleets to purchase hydrogen-fueled vehicles, using synergies with other technologies (vehicles with internal combustion engines, hybrid vehicles, biofuels of second generation..), harmonizing hydrogen national regulations at the European scale. (J.S.)

  18. Characterization of rapidly-prototyped, battery-operated, argon-hydrogen microplasma on a hybrid chip for elemental analysis of microsamples by portable optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Weagant, Scott; Dulai, Gurjit; Li, Lu; Karanassios, Vassili, E-mail: vkaranassios@uwaterloo.ca

    2015-04-01

    A rapidly-prototyped, battery-operated, atmospheric-pressure, self-igniting Ar-H{sub 2} microplasma was interfaced to a portable fiber-optic spectrometer. The microplasma-spectrometer combination was used to document the spectral lines emitted when μL of dilute solutions of single element standards of Ag, Ba, Ca, Eu, Pd, Rb and Sr were first dried and then vaporized into the microplasma. A small-size, electrothermal vaporization system was used for microsample introduction. Identification of the prominent spectral lines for these elements is reported. It was found that the most prominent spectral line for Ba, Ca and Sr was different than that emitted from an inductively coupled plasma (ICP). In general, prominent spectral lines with low excitation energy were dominating, thus resulting in spectra simpler than those emitted from an ICP. Detection limits were between 45 and 180 pg (expressed in absolute amounts). When expressed in relative concentration units, they ranged between 15 and 60 μg/L (obtained using 3 μL diluted standards). Calibration curves were linear (on the average) for 1.5 orders-of-magnitude. Average precision was 15%. Analytical capability and utility was demonstrated using the determination of Ca and Mg in (medicinal) thermal spring water. - Highlights: • Microplasma emission spectra for Ag, Ba, Ca, Eu, Pd, Rb and Sr are reported. • Absolute amount detection limits ranged between 45 pg and 180 pg. • Relative unit detection limits ranged between 15 and 60 μg/L (using 3 μL). • The effect of vaporization temperature on analyte signals is reported. • Ca and Mg concentrations in (medicinal) thermal spring water were determined.

  19. Characterization of rapidly-prototyped, battery-operated, argon-hydrogen microplasma on a hybrid chip for elemental analysis of microsamples by portable optical emission spectrometry

    International Nuclear Information System (INIS)

    Weagant, Scott; Dulai, Gurjit; Li, Lu; Karanassios, Vassili

    2015-01-01

    A rapidly-prototyped, battery-operated, atmospheric-pressure, self-igniting Ar-H 2 microplasma was interfaced to a portable fiber-optic spectrometer. The microplasma-spectrometer combination was used to document the spectral lines emitted when μL of dilute solutions of single element standards of Ag, Ba, Ca, Eu, Pd, Rb and Sr were first dried and then vaporized into the microplasma. A small-size, electrothermal vaporization system was used for microsample introduction. Identification of the prominent spectral lines for these elements is reported. It was found that the most prominent spectral line for Ba, Ca and Sr was different than that emitted from an inductively coupled plasma (ICP). In general, prominent spectral lines with low excitation energy were dominating, thus resulting in spectra simpler than those emitted from an ICP. Detection limits were between 45 and 180 pg (expressed in absolute amounts). When expressed in relative concentration units, they ranged between 15 and 60 μg/L (obtained using 3 μL diluted standards). Calibration curves were linear (on the average) for 1.5 orders-of-magnitude. Average precision was 15%. Analytical capability and utility was demonstrated using the determination of Ca and Mg in (medicinal) thermal spring water. - Highlights: • Microplasma emission spectra for Ag, Ba, Ca, Eu, Pd, Rb and Sr are reported. • Absolute amount detection limits ranged between 45 pg and 180 pg. • Relative unit detection limits ranged between 15 and 60 μg/L (using 3 μL). • The effect of vaporization temperature on analyte signals is reported. • Ca and Mg concentrations in (medicinal) thermal spring water were determined

  20. Solar powered hydrogen generating facility and hydrogen powered vehicle fleet. Final technical report, August 11, 1994--January 6, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, J.J.

    1997-04-01

    This final report describes activities carried out in support of a demonstration of a hydrogen powered vehicle fleet and construction of a solar powered hydrogen generation system. The hydrogen generation system was permitted for construction, constructed, and permitted for operation. It is not connected to the utility grid, either for electrolytic generation of hydrogen or for compression of the gas. Operation results from ideal and cloudy days are presented. The report also describes the achievement of licensing permits for their hydrogen powered trucks in California, safety assessments of the trucks, performance data, and information on emissions measurements which demonstrate performance better than the Ultra-Low Emission Vehicle levels.

  1. Hydrogen, energy vector of the future?

    International Nuclear Information System (INIS)

    Perrin, J.; Deschamps, J.F.

    2004-01-01

    In the framework of a sustainable development with a reduction of the greenhouse gases emissions, the hydrogen seems a good solution because its combustion produces only water. From the today hydrogen industrial market, the authors examine the technological challenges and stakes of the hydrogen-energy. They detail the hydrogen production, distribution and storage and compare with the petrol and the natural gas. Then they explain the fuel cells specificity and realize a classification of the energy efficiency of many associations production-storage-distribution-use. a scenario of transition is proposed. (A.L.B.)

  2. Hydrogen - the energy source of the future

    International Nuclear Information System (INIS)

    Aakervik, Anne-Lise

    2001-01-01

    The use of hydrogen is an excellent way of reducing the emission of greenhouse gases. It causes no emission when used in fuel cells. Iceland has set itself the goal of becoming the world's first hydrogen society without emission of carbon dioxide and other greenhouse gases. In the USA, California has decided to concentrate on cars that do not pollute. Hydrogen power is then an interesting alternative. Germany, Japan and the USA are all concentrating on hydrogen. The world production of hydrogen is 50 million tons, 90 per cent of which is made from fossil material, 4 per cent by electrolysis of water. The largest consumers of hydrogen are the petroleum industry and the fertilizer industry. The sale of hydrogen in the refining industry has increased recently and is expected to rise substantially when the fuel cell technology is commercialized. At present, storage of hydrogen is the major problem. Gas storage at atmospheric pressure is inconvenient because of the large volumes required. Alternatives are storage as compressed gas under high pressure, liquid gas at low temperature, storage in metal hydrides or carbon materials, or chemically bound in methanol or ammonia

  3. Benchmarking the internal combustion engine and hydrogen

    International Nuclear Information System (INIS)

    Wallace, J.S.

    2006-01-01

    The internal combustion engine is a cost-effective and highly reliable energy conversion technology. Exhaust emission regulations introduced in the 1970's triggered extensive research and development that has significantly improved in-use fuel efficiency and dramatically reduced exhaust emissions. The current level of gasoline vehicle engine development is highlighted and representative emissions and efficiency data are presented as benchmarks. The use of hydrogen fueling for IC engines has been investigated over many decades and the benefits and challenges arising are well-known. The current state of hydrogen-fueled engine development will be reviewed and evaluated against gasoline-fueled benchmarks. The prospects for further improvements to hydrogen-fueled IC engines will be examined. While fuel cells are projected to offer greater energy efficiency than IC engines and zero emissions, the availability of fuel cells in quantity at reasonable cost is a barrier to their widespread adaptation for the near future. In their current state of development, hydrogen fueled IC engines are an effective technology to create demand for hydrogen fueling infrastructure until fuel cells become available in commercial quantities. During this transition period, hydrogen fueled IC engines can achieve PZEV/ULSLEV emissions. (author)

  4. The hydrogen economy - an opportunity for gas

    International Nuclear Information System (INIS)

    Soederbaum, J.; Martin, G.; O'Neill, C.

    2003-01-01

    Natural gas could play a pivotal role in any transition to a hydrogen economy-that is one of the findings of the recently-released National Hydrogen Study, commissioned by the Commonwealth Department of Industry, Tourism and Resources, and undertaken by the consulting firms ACIL Tasman and Parsons Brinckerhoff. The key benefits of hydrogen include zero emissions at the point of combustion (water is the main by-product) and its abundance Hydrogen can be produced from a range of primary energy sources including gas and coal, or through the electrolysis of water. Depending on the process used to manufacture hydrogen (especially the extent to which any associated carbon can be captured and sequestered), life-cycle emissions associated with its production and use can be reduced or entirely eliminated

  5. Canadian Hydrogen Association workshop on building Canadian strength with hydrogen systems. Proceedings

    International Nuclear Information System (INIS)

    2006-01-01

    The Canadian Hydrogen Association workshop on 'Building Canadian Strength with Hydrogen Systems' was held in Montreal, Quebec, Canada on October 19-20, 2006. Over 100 delegates attended the workshop and there were over 50 presentations made. The Canadian Hydrogen Association (CHA) promotes the development of a hydrogen infrastructure and the commercialization of new, efficient and economic methods that accelerate the adoption of hydrogen technologies that will eventually replace fossil-based energy systems to reduce greenhouse gas emissions. This workshop focused on defining the strategic direction of research and development that will define the future of hydrogen related energy developments across Canada. It provided a forum to strengthen the research, development and innovation linkages among government, industry and academia to build Canadian strength with hydrogen systems. The presentations described new technologies and the companies that are making small scale hydrogen and hydrogen powered vehicles. Other topics of discussion included storage issues, hydrogen safety, competition in the hydrogen market, hydrogen fuel cell opportunities, nuclear-based hydrogen production, and environmental impacts

  6. 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)

  7. Features of the spectroscopic determination of the isotope composition of trace amounts of hydrogen in helium

    International Nuclear Information System (INIS)

    Nemets, V.M.; Petrov, A.A.; Solov'ev, A.A.

    1986-01-01

    The investigation of the magnitude of the isotope effect in the intensiti of the beta lines of the Balmer series was carried out with the excitation of a high-frequency discharge in a quartz tube having a diameter of ca.6.5 at pressures of the gaseous mixture ranging from 1 to 70 kPa. From the experimental results here it follows that as the isotopes of hydrogen are diluted with helium, the value of K decreases from 1.2-1.1 to 0.84-0.86, and the maximum of the plots of K= f(P) broaden and move toward higher pressures. In order to account for the laws obtained, the authors examined a set of elementary processes and reactions for which the isotope-related differences in the rate constants (alpha) can influence the relative concentrations of the excited atoms of the isotopes of hydrogen in a discharge. The physical model presented in this paper of the shaping of the isotope effects in the atomic spectrum of hydrogen makes it possible to account for the observed laws governing the excitation of a discharge in a mixture of the isotopes of hydrogen with helium and thus greatly facilitates the selection of the optimal conditions for the excitation of the analytical spectrum in devising procedures for the spectroscopic isotope determination of trace impurities of hydrogen in helium

  8. Towards a hydrogen-driven society? Calculations and neutron scattering on potential hydrogen storage materials

    OpenAIRE

    Schimmel, H.G.

    2005-01-01

    For sustainable development, the resources of the earth need to be maintained and carbon dioxide emission should be avoided. In particular, we need to find an alternative for the use of fossil fuels in vehicles. Since long, hydrogen has been recognised as the fuel of the future because it exhausts only water when used in fuel cells and hardly any pollutants when used in conventional internal combustion engines. However, the storage of hydrogen onboard vehicles is a major concern. Hydrogen is ...

  9. 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

  10. Hydrogen: Adding Value and Flexibility to the Nuclear Power Industry

    International Nuclear Information System (INIS)

    Lee, J.; Bhatt, V.; Friley, P.; Horak, W.; Reisman, A.

    2004-01-01

    The objective of this study was to assess potential synergies between the hydrogen economy and nuclear energy options. Specifically: to provide a market analysis of advanced nuclear energy options for hydrogen production in growing hydrogen demand; to conduct an impact evaluation of nuclear-based hydrogen production on the economics of the energy system, environmental emissions, and energy supply security; and to identify competing technologies and challenges to nuclear options

  11. Life cycle assessment of hydrogen production and fuel cell systems

    International Nuclear Information System (INIS)

    Dincer, I.

    2007-01-01

    This paper details life cycle assessment (LCA) of hydrogen production and fuel cell system. LCA is a key tool in hydrogen and fuel cell technologies for design, analysis, development; manufacture, applications etc. Energy efficiencies and greenhouse gases and air pollution emissions have been evaluated in all process steps including crude oil and natural gas pipeline transportation, crude oil distillation, natural gas reprocessing, wind and solar electricity generation , hydrogen production through water electrolysis and gasoline and hydrogen distribution and utilization

  12. MAHRES: Spanish hydrogen geography

    International Nuclear Information System (INIS)

    Bordallo, C.R.; Moreno, E.; Brey, R.; Guerrero, F.M.; Carazo, A.F.

    2004-01-01

    Nowadays, it is common to hear about the hydrogen potential as an energetic vector or the renewable character of fuel cells; thus, the conjunction between both of them as a way to produce electricity, decreasing pollutant emission, is often discussed. However, that renewable character is only guaranteed in the case that the hydrogen used comes from some renewable energy source. Because of that, and due to the Spanish great potential related to natural usable resources like water, sun, wind or biomass, for instance, it seems attractive to make a meticulous study (supported by the statistical Multicriteria Decision Making Method) in order to quantify that potential and place it in defined geographical areas. Moreover, the growth of the electricity demand is always significant, and in this way the energy consumption in Spain is estimated to grow up to 3'4 % above the average during the next ten years. On the other hand, it must be taken into account that the contribution of the oil production will not be enough in the future. The study being carried out will try to elaborate 'The Spanish Renewable Hydrogen Map', that would contemplate, not only the current situation but also predictable scenarios and their implementation. (author)

  13. Hydrogen and nuclear energy

    International Nuclear Information System (INIS)

    Duffey, R.B.; Miller, A.I.; Hancox, W.T.; Pendergast, D.R.

    1999-01-01

    The current world-wide emphasis on reducing greenhouse gas (GHG) emissions provides an opportunity to revisit how energy is produced and used, consistent with the need for human and economic growth. Both the scale of the problem and the efforts needed for its resolution are extremely large. We argue that GHG reduction strategies must include a greater penetration of electricity into areas, such as transportation, that have been the almost exclusive domain of fossil fuels. An opportunity for electricity to displace fossil fuel use is through electrolytic production of hydrogen. Nuclear power is the only large-scale commercially proven non-carbon electricity generation source, and it must play a key role. As a non-carbon power source, it can also provide the high-capacity base needed to stabilize electricity grids so that they can accommodate other non-carbon sources, namely low-capacity factor renewables such as wind and solar. Electricity can be used directly to power standalone hydrogen production facilities. In the special case of CANDU reactors, the hydrogen streams can be preprocessed to recover the trace concentrations of deuterium that can be re-oxidized to heavy water. World-wide experience shows that nuclear power can achieve high standards of public safety, environmental protection and commercially competitive economics, and must . be an integral part of future energy systems. (author)

  14. Ammonia for hydrogen storage: challenges and opportunities

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Christensen, Claus H.; Nørskov, Jens Kehlet

    2008-01-01

    The possibility of using ammonia as a hydrogen carrier is discussed. Compared to other hydrogen storage materials, ammonia has the advantages of a high hydrogen density, a well-developed technology for synthesis and distribution, and easy catalytic decomposition. Compared to hydrocarbons...... and alcohols, it has the advantage that there is no CO2 emission at the end user. The drawbacks are mainly the toxicity of liquid ammonia and the problems related to trace amounts of ammonia in the hydrogen after decomposition. Storage of ammonia in metal ammine salts is discussed, and it is shown...... that this maintains the high volumetric hydrogen density while alleviating the problems of handling the ammonia. Some of the remaining challenges for research in ammonia as a hydrogen carrier are outlined....

  15. Energetic neutral atom precipitation during magnetic storms: optical emission, ionization, and energy deposition at low and middle latitudes

    International Nuclear Information System (INIS)

    Tinsley, B.A.

    1979-01-01

    Observations of hydrogen Balmer β and He + 4686-A emission made at Huancayo, Peru, during two magnetic storms are consistent with the expectations of energetic neutral atom precipitation resulting from charge exchange loss of ring current ions and support the view that charge exchange is the major loss process for larger geomagnetic storms. The intensities are consistent with previous satellite observations of the emission (called the equatorial aurora) and when translated into ionization rates for the upper E region give production rates in order of magnitude larger than normal nighttime levels. Such ionization enhancements have previously been measured by ionosondes and incoherent scatter at low latitudes and attributed to electron precipitation. New calculations of the latitude variation correct earlier work and show that for a ring current with pitch angle distribution isotropic to the loss cone, located on shells of L value 2 to 6, the maximum influx rate of precipitating neutrals is found at magnetic latitudes 25 0 to 50 0 . Most of the energetic neutrals are lost to interplanetary space, and the fraction impacting the thermosphere has been recalculated to range from 11 to 2.2% for L values 2 to 6. For a typical magnetic storm with energy loss rate due to charge exchange, the equivalent to a Dst rate of change of 20 n T/h, the energy input into the thermosphere at the latitude of maximum is calculated to be 0.15 to 0.05 mW/m 2 from L shells 2 to 6. The ionization production can be of the order of 10 ions cm 3 s 1 at 140 km, and optical emission, of the order of 1 rayleigh (R), both varying according to the species and energy of the impacting neutrals (i.e., the former ring current ions). The latitude distribution shrinks toward the equator after injection has ceased, as the magnetospheric pitch angle distribution evolves toward 90 0 , on a time scale (for protons <30 keV at L=3) of the order of 2 hours

  16. Hydrogen from nuclear energy and the impact on climate change

    International Nuclear Information System (INIS)

    Duffey, R.B.; Miller, A.I.; Poehnell, T.G.

    2001-01-01

    The two major candidates for hydrogen production include nuclear power and other renewable energy sources. However, hydrogen produced by steam reforming of natural gas offers little advantage in total cycle greenhouse gas (GHG) emissions over hybrid internal combustion engine (ICE) technology. Only nuclear power offers the possibility of cutting GHG emissions significantly and to economically provide electricity for traditional applications and by producing hydrogen for its widespread use in the transportation sector. Using nuclear energy to produce hydrogen for transportation fuel, doubles or triples nuclear's capacity to reduce GHG emissions. An analysis at the Atomic Energy of Canada shows that a combination of hydrogen fuel and nuclear energy can stabilize GHG emissions and climate change for a wide range of the latest scenarios presented by the Intergovernmental Panel on Climate Change. The technology for replacing hydrocarbon fuels with non-polluting hydrogen exists with nuclear power, electrolysis and fuel cells, using electric power grids for distribution. It was emphasized that a move toward total emissions-free transportation will be a move towards solving the negative effects of climate change. This paper illustrated the trends between global economic and atmospheric carbon dioxide concentrations. Low carbon dioxide emission energy alternatives were discussed along with the sources of hydrogen and the full cycle assessment results in reduced emissions. It was shown that deploying 20 CANDU NPPs (of 690 MW (e) net each) would fuel 13 million vehicles with the effect of levelling of carbon dioxide emissions from transportation between 2020 to 2030. 13 refs., 2 tabs., 3 figs

  17. Hydrogen engine performance analysis. First annual report

    Energy Technology Data Exchange (ETDEWEB)

    Adt, Jr., R. R.; Swain, M. R.; Pappas, J. M.

    1978-08-01

    Many problems associated with the design and development of hydrogen-air breathing internal combustion engines for automotive applications have been identified by various domestic and foreign researchers. This project addresses the problems identified in the literature, seeks to evaluate potential solutions to these problems, and will obtain and document a design data-base convering the performance, operational and emissions characteristics essential for making rational decisions regarding the selection and design of prototype hydrogen-fueled, airbreathing engines suitable for manufacture for general automotive use. Information is included on the operation, safety, emission, and cost characteristics of hydrogen engines, the selection of a test engine and testing facilities, and experimental results. Baseline data for throttled and unthrottled, carburetted, hydrogen engine configurations with and without exhaust gas recirculation and water injection are presented. In addition to basic data gathering concerning performance and emissions, the test program conducted was formulated to address in detail the two major problems that must be overcome if hydrogen-fueled engines are to become viable: flashback and comparatively high NO/sub x/ emissions at high loads. In addition, the results of other hydrogen engine investigators were adjusted, using accepted methods, in order to make comparisons with the results of the present study. The comparisons revealed no major conflicts. In fact, with a few exceptions, there was found to be very good agreement between the results of the various studies.

  18. Global environmental impacts of the hydrogen economy

    International Nuclear Information System (INIS)

    Derwent, R.; Simmonds, P.; O'Doherty, S.; Manning, A.; Collins, W.; Stevenson, D.

    2006-01-01

    Hydrogen-based energy systems appear to be an attractive proposition in providing a future replacement for the current fossil-fuel based energy systems. Hydrogen is an important, though little studied, trace component of the atmosphere. It is present at the mixing ratio of about 510 ppb currently and has important man-made and natural sources. Because hydrogen reacts with tropospheric hydroxyl radicals, emissions of hydrogen to the atmosphere perturb the distributions of methane and ozone, the second and third most important greenhouse gases after carbon dioxide. Hydrogen is therefore an indirect greenhouse gas with a global warming potential GWP of 5.8 over a 100-year time horizon. A future hydrogen economy would therefore have greenhouse consequences and would not be free from climate perturbations. If a global hydrogen economy replaced the current fossil fuel-based energy system and exhibited a leakage rate of 1%, then it would produce a climate impact of 0.6% of the current fossil fuel based system. Careful attention must be given to reduce to a minimum the leakage of hydrogen from the synthesis, storage and use of hydrogen in a future global hydrogen economy if the full climate benefits are to be realised. (author)

  19. Hydrogen-Assisted IC Engine Combustion as a Route to Hydrogen Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Andre Boehman; Daniel Haworth

    2008-09-30

    The 'Freedom Car' Initiative announced by the Bush Administration has placed a significant emphasis on development of a hydrogen economy in the United States. While the hydrogen-fueled fuel-cell vehicle that is the focus of the 'Freedom Car' program would rely on electrochemical energy conversion, and despite the large amount of resources being devoted to its objectives, near-term implementation of hydrogen in the transportation sector is not likely to arise from fuel cell cars. Instead, fuel blending and ''hydrogen-assisted'' combustion are more realizable pathways for wide-scale hydrogen utilization within the next ten years. Thus, a large potential avenue for utilization of hydrogen in transportation applications is through blending with natural gas, since there is an existing market for natural-gas vehicles of various classes, and since hydrogen can provide a means of achieving even stricter emissions standards. Another potential avenue is through use of hydrogen to 'assist' diesel combustion to permit alternate combustion strategies that can achieve lower emissions and higher efficiency. This project focused on developing the underlying fundamental information to support technologies that will facilitate the introduction of coal-derived hydrogen into the market. Two paths were envisioned for hydrogen utilization in transportation applications. One is for hydrogen to be mixed with other fuels, specifically natural gas, to enhance performance in existing natural gas-fueled vehicles (e.g., transit buses) and provide a practical and marketable avenue to begin using hydrogen in the field. A second is to use hydrogen to enable alternative combustion modes in existing diesel engines, such as homogeneous charge compression ignition, to permit enhanced efficiency and reduced emissions. Thus, this project on hydrogen-assisted combustion encompassed two major objectives: (1) Optimization of hydrogen-natural gas mixture

  20. 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.)

  1. A new beam emission polarimetry diagnostic for measuring the magnetic field line angle at the plasma edge of ASDEX Upgrade.

    Science.gov (United States)

    Viezzer, E; Dux, R; Dunne, M G

    2016-11-01

    A new edge beam emission polarimetry diagnostic dedicated to the measurement of the magnetic field line angle has been installed on the ASDEX Upgrade tokamak. The new diagnostic relies on the motional Stark effect and is based on the simultaneous measurement of the polarization direction of the linearly polarized π (parallel to the electric field) and σ (perpendicular to the electric field) lines of the Balmer line D α . The technical properties of the system are described. The calibration procedures are discussed and first measurements are presented.

  2. HYDROGEN USE IN INTERNAL COMBUSTION ENGINE:

    OpenAIRE

    Ciniviz, Murat

    2012-01-01

    Fast depletion of fossil fuels is urgently demanding a carry out work for research to find out the viable alternative fuels for meeting sustainable energy demand with minimum environmental impact. In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms. The use of the hydrogen as fuel in the internal combusti...

  3. Hydrogen delivery technology rRoadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2005-11-01

    Hydrogen holds the long-term potential to solve two critical problems related to the energy infrastructure: U.S. dependence on foreign oil and U.S. emissions of greenhouse gases and pollutants. The U.S. transportation sector is almost completely reliant on petroleum, over half of which is currently imported, and tailpipe emissions remain one of the country’s key air quality concerns. Fuel cell vehicles operating on hydrogen produced from domestically available resources – including renewable resources, coal with carbon sequestration, or nuclear energy – would dramatically decrease greenhouse gases and other emissions, and would reduce dependence on oil from politically volatile regions of the world. Clean, domestically-produced hydrogen could also be used to generate electricity in stationary fuel cells at power plants, further extending national energy and environmental benefits.

  4. Potential of the HTGR hydrogen cogeneration system in Japan

    International Nuclear Information System (INIS)

    Nishihara, Tetsuo; Mouri, Tomoaki; Kunitomi, Kazuhiko

    2007-01-01

    A high temperature gas cooled reactor (HTGR) is one of the next generation nuclear systems. The HTGR hydrogen cogeneration system can produce not only electricity but also hydrogen. Then it has a potential to supply massive low-cost hydrogen without greenhouse gas emission for the future hydrogen society. Japan Atomic Energy Agency (JAEA) has been carried out the design study of the HTGR hydrogen cogeneration system (GTHTR300C). The thermal power of the reactor is 600 MW. The hydrogen production plant utilizes 370 MW and can supply 52,000 m 3 /h (0.4 Bm 3 /y) of hydrogen. Present industrial hydrogen production capacity in Japan is about 18 Bm 3 /y and it will decrease by 15 Bm 3 /y in 2030 due to the aging facilities. On the other hand, the hydrogen demand for fuel cell vehicle (FCV) in 2030 is estimated at 15 Bm 3 /y at a maximum. Since the hydrogen supply may be short after 2030, the additional hydrogen should be produced by clean hydrogen process to reduce greenhouse gas emission. This hydrogen shortage is a potential market for the GTHTR300C. The hydrogen production cost of GTHTR300C is estimated at 20.5 JPY/Nm 3 which has an economic competitiveness against other industrial hydrogen production processes. 38 units of the GTHTR300C can supply a half of this shortage which accounts for the 33% of hydrogen demand for FCV in 2100. According to the increase of hydrogen demand, the GTHTR300C should be constructed after 2030. (author)

  5. Advanced Hydrogen Turbine Development

    Energy Technology Data Exchange (ETDEWEB)

    Marra, John [Siemens Energy, Inc., Orlando, FL (United States)

    2015-09-30

    Under the sponsorship of the U.S. Department of Energy (DOE) National Energy Technology Laboratories, Siemens has completed the Advanced Hydrogen Turbine Development Program to develop an advanced gas turbine for incorporation into future coal-based Integrated Gasification Combined Cycle (IGCC) plants. All the scheduled DOE Milestones were completed and significant technical progress was made in the development of new technologies and concepts. Advanced computer simulations and modeling, as well as subscale, full scale laboratory, rig and engine testing were utilized to evaluate and select concepts for further development. Program Requirements of: A 3 to 5 percentage point improvement in overall plant combined cycle efficiency when compared to the reference baseline plant; 20 to 30 percent reduction in overall plant capital cost when compared to the reference baseline plant; and NOx emissions of 2 PPM out of the stack. were all met. The program was completed on schedule and within the allotted budget

  6. Circumnebular neutral hydrogen in planetary nebulae

    International Nuclear Information System (INIS)

    Taylor, A.R.; Gussie, G.T.; Pottasch, S.R.

    1990-01-01

    Centimeter line observations of six compact planetary nebulae are reported. Circumnebular atomic hydrogen absorption has been observed in NGC 6790, NGC 6886, IC 418, IC 5117, and BD +30 deg 3639, while H I was not observed to a high upper limit in NGC 6741. Hydrogen was also detected in emission from BD +30 deg 3639. The expansion velocities of the circumnebular envelopes are similar to the expansion velocities observed for the ionized nebula. The optical depth of circumnebular H I appears to decrease with increasing linear radius of the ionized nebulae, indicating that these nebulae are ionization bounded and that the amount of atomic hydrogen decreases as young nebulas evolve. 28 refs

  7. Continuum emission in the 1980 July 1 solar flare

    International Nuclear Information System (INIS)

    Zirin, H.; Neidig, D.F.

    1981-01-01

    Comparison of continuum measurements of the 1980 July 1 flare at Big Bear Solar Observatory and Sacramento Peak Observatory show strong blue emission kernels with the ratio of Balmer continuum (Bac):lambda3862 continuum:continuum above 4275 A to be about 10:5:1. The blue continuum at 3862 A is too strong to be explained by unresolved lines. The Bac intensity was 2.5 times the photosphere and the strongest lambda3862 continuum was 2 times the photosphere. The brightest continuum kernel occurred late in the flare, after the hard X-ray peak and related in time to an isolated peak in the 2.2 MeV line, suggesting that the continuum was excited by protons above 20 MeV

  8. 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.

  9. BROAD BALMER WINGS IN BA HYPER/SUPERGIANTS DISTORTED BY DIFFUSE INTERSTELLAR BANDS: FIVE EXAMPLES IN THE 30 DORADUS REGION FROM THE VLT-FLAMES TARANTULA SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Walborn, Nolan R.; Sana, Hugues; Sabbi, Elena, E-mail: walborn@stsci.edu, E-mail: hsana@stsci.edu, E-mail: sabbi@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2015-08-10

    Extremely broad emission wings at Hβ and Hα have been found in VLT-FLAMES Tarantula Survey data for five very luminous BA supergiants in or near 30 Doradus in the Large Magellanic Cloud. The profiles of both lines are extremely asymmetrical, which we have found to be caused by very broad diffuse interstellar bands (DIBs) in the longward wing of Hβ and the shortward wing of Hα. These DIBs are well known to interstellar but not to many stellar specialists, so that the asymmetries may be mistaken for intrinsic features. The broad emission wings are generally ascribed to electron scattering, although we note difficulties for that interpretation in some objects. Such profiles are known in some Galactic hyper/supergiants and are also seen in both active and quiescent Luminous Blue Variables (LBVs). No prior or current LBV activity is known in these 30 Dor stars, although a generic relationship to LBVs is not excluded; subject to further observational and theoretical investigation, it is possible that these very luminous supergiants are approaching the LBV stage for the first time. Their locations in the HRD and presumed evolutionary tracks are consistent with that possibility. The available evidence for spectroscopic variations of these objects is reviewed, while recent photometric monitoring does not reveal variability. A search for circumstellar nebulae has been conducted, with an indeterminate result for one of them.

  10. Hydrogen engine performance analysis project. Second annual report

    Energy Technology Data Exchange (ETDEWEB)

    Adt, Jr., R. R.; Swain, M. R.; Pappas, J. M.

    1980-01-01

    Progress in a 3 year research program to evaluate the performance and emission characteristics of hydrogen-fueled internal combustion engines is reported. Fifteen hydrogen engine configurations will be subjected to performance and emissions characterization tests. During the first two years, baseline data for throttled and unthrottled, carburetted and timed hydrogen induction, Pre IVC hydrogen-fueled engine configurations, with and without exhaust gas recirculation (EGR) and water injection, were obtained. These data, along with descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained, are given. Analyses of other hydrogen-engine project data are also presented and compared with the results of the present effort. The unthrottled engine vis-a-vis the throttled engine is found, in general, to exhibit higher brake thermal efficiency. The unthrottled engine also yields lower NO/sub x/ emissions, which were found to be a strong function of fuel-air equivalence ratio. (LCL)

  11. The potential impact of hydrogen energy use on the atmosphere

    Science.gov (United States)

    van Ruijven, B. J.; Lamarque, J. F.; van Vuuren, D. P.; Kram, T.; Eerens, H.

    2009-04-01

    Energy models show very different trajectories for future energy systems (partly as function of future climate policy). One possible option is a transition towards a hydrogen-based energy system. The potential impact of such hydrogen economy on atmospheric emissions is highly uncertain. On the one hand, application of hydrogen in clean fuel cells reduces emissions of local air pollutants, like SOx and NOx. On the other hand, emissions of hydrogen from system leakages are expected to change the atmospheric concentrations and behaviour (see also Price et al., 2007; Sanderson et al., 2003; Schultz et al., 2003; Tromp et al., 2003). The uncertainty arises from several sources: the expected use of hydrogen, the intensity of leakages and emissions, and the atmospheric chemical behaviour of hydrogen. Existing studies to the potential impacts of a hydrogen economy on the atmosphere mostly use hydrogen emission scenarios that are based on simple assumptions. This research combines two different modelling efforts to explore the range of impacts of hydrogen on atmospheric chemistry. First, the potential role of hydrogen in the global energy system and the related emissions of hydrogen and other air pollutants are derived from the global energy system simulation model TIMER (van Vuuren, 2007). A set of dedicated scenarios on hydrogen technology development explores the most pessimistic and optimistic cases for hydrogen deployment (van Ruijven et al., 2008; van Ruijven et al., 2007). These scenarios are combined with different assumptions on hydrogen emission factors. Second, the emissions from the TIMER model are linked to the NCAR atmospheric model (Lamarque et al., 2005; Lamarque et al., 2008), in order to determine the impacts on atmospheric chemistry. By combining an energy system model and an atmospheric model, we are able to consistently explore the boundaries of both hydrogen use, emissions and impacts on atmospheric chemistry. References: Lamarque, J.-F., Kiehl, J. T

  12. Optical emission line spectra of Seyfert galaxies and radio galaxies

    International Nuclear Information System (INIS)

    Osterbrock, D.E.

    1978-01-01

    Many radio galaxies have strong emission lines in their optical spectra, similar to the emission lines in the spectra of Seyfert galaxies. The range of ionization extends from [O I] and [N I] through [Ne V] and [Fe VII] to [Fe X]. The emission-line spectra of radio galaxies divide into two types, narrow-line radio galaxies whose spectra are indistinguishable from Seyfert 2 galaxies, and broad-line radio galaxies whose spectra are similar to Seyfert 1 galaxies. However on the average the broad-line radio galaxies have steeper Balmer decrements, stronger [O III] and weaker Fe II emission than the Seyfert 1 galaxies, though at least one Seyfert 1 galaxy not known to be a radio source has a spectrum very similar to typical broad-line radio galaxies. Intermediate-type Seyfert galaxies exist that show various mixtures of the Seyfert 1 and Seyfert 2 properties, and the narrow-line or Seyfert 2 property seems to be strongly correlated with radio emission. (Auth.)

  13. 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)

  14. Exergetic life cycle assessment of hydrogen production from renewables

    Science.gov (United States)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

    Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38

  15. Hydrogen economy and nuclear energy

    International Nuclear Information System (INIS)

    Knapp, V.

    2004-01-01

    Global energy outlooks based on present trends, such as WETO study, give little optimism about fulfilling Kyoto commitments in controlling CO2 emissions and avoiding unwanted climate consequences. Whilst the problem of radioactive waste has a prominence in public, in spite of already adequate technical solutions of safe storage for future hundreds and thousands of years, there s generally much less concern with influence of fossil fuels on global climate. In addition to electricity production, process heat and transportation are approximately equal contributors to CO2 emission. Fossil fuels in transportation present also a local pollution problem in congested regions. Backed by extensive R and D, hydrogen economy is seen as the solution, however, often without much thought where from the hydrogen in required very large quantities may come. With welcome contributions from alternative sources, nuclear energy is the only source of energy capable of producing hydrogen in very large amounts, without parallel production of CO2. Future high temperature reactors could do this most efficiently. In view of the fact that nuclear weapon proliferation is not under control, extrapolation from the present level of nuclear power to the future level required by serious attempts to reduce global CO2 emission is a matter of justified concern. Finding the sites for many hundreds of new reactors would, alone, be a formidable problem in developed regions with high population density. What is generally less well understood and not validated is that the production of nuclear hydrogen allows the required large increases of nuclear power without the accompanied increase of proliferation risks. Unlike electricity, hydrogen can be economically shipped or transported by pipelines to places very far from the place of production. Thus, nuclear production of hydrogen can be located and concentrated at few remote, controllable sites, far from the population centers and consumption regions. At such

  16. Universal FFM Hydrogen Spectral Line Shapes Applied to Ions and Electrons

    Science.gov (United States)

    Mossé, C.; Calisti, A.; Ferri, S.; Talin, B.; Bureyeva, L. A.; Lisitsa, V. S.

    2008-10-01

    We present a method for the calculation of hydrogen spectral line shapes based on two combined approaches: Universal Model and FFM procedure. We start with the analytical functions for the intensities of the Stark components of radiative transitions between highly excited atomic states with large values of principal quantum numbers n,n'γ1, with Δn = n-n'≪n for the specific cases of Hn-α line (Δn = 1) and Hn-β line (Δn = 2). The FFM line shape is obtained by averaging on the electric field of the Hooper's field distribution for ion and electron perturber dynamics and by mixing the Stark components with a jumping frequency rate ve (vi) where v = N1/3u (N is electron density and u is the ion or electron thermal velocity). Finally, the total line shape is given by convolution of ion and electron line shapes. Hydrogen line shape calculations for Balmer Hα and Hβ lines are compared to experimental results in low density plasma (Ne˜1016-1017cm-3) and low electron temperature in order of 10 000K. This method relying on analytic expressions permits fast calculation of Hn-α and Hn-β lines of hydrogen and could be used in the study of the Stark broadening of radio recombination lines for high principal quantum number.

  17. A new type of hydrogen generator-HHEG (high-compressed hydrogen energy generator)

    International Nuclear Information System (INIS)

    Harada, H.; Tojima, K.; Takeda, M.; Nakazawa, T.

    2004-01-01

    'Full text:' We have developed a new type of hydrogen generator named HHEG (High-compressed Hydrogen Energy Generator). HHEG can produce 35 MPa high-compressed hydrogen for fuel cell vehicle without any mechanical compressor. HHEG is a kind of PEM(proton exchange membrane)electrolysis. It was well known that compressed hydrogen could be generated by water electrolysis. However, the conventional electrolysis could not generate 35 MPa or higher pressure that is required for fuel cell vehicle, because electrolysis cell stack is destroyed in such high pressure. In HHEG, the cell stack is put in high-pressure vessel and the pressure difference of oxygen and hydrogen that is generated by the cell stack is always kept at nearly zero by an automatic compensator invented by Mitsubishi Corporation. The cell stack of HHEG is not so special one, but it is not broken under such high pressure, because the automatic compensator always offsets the force acting on the cell stack. Hydrogen for fuel cell vehicle must be produce by no emission energy such as solar and atomic power. These energies are available as electricity. So, water electrolysis is the only way of producing hydrogen fuel. Hydrogen fuel is also 35 MPa high-compressed hydrogen and will become 70 MPa in near future. But conventional mechanical compressor is not useful for such high pressure hydrogen fuel, because of the short lifetime and high power consumption. Construction of hydrogen station network is indispensable in order to come into wide use of fuel cell vehicles. For such network contraction, an on-site type hydrogen generator is required. HHEG can satisfy above these requirements. So we can conclude that HHEG is the only way of realizing the hydrogen economy. (author)

  18. Atomistic Modelling of Materials for Clean Energy Applications : hydrogen generation, hydrogen storage, and Li-ion battery

    OpenAIRE

    Qian, Zhao

    2013-01-01

    In this thesis, a number of clean-energy materials for hydrogen generation, hydrogen storage, and Li-ion battery energy storage applications have been investigated through state-of-the-art density functional theory. As an alternative fuel, hydrogen has been regarded as one of the promising clean energies with the advantage of abundance (generated through water splitting) and pollution-free emission if used in fuel cell systems. However, some key problems such as finding efficient ways to prod...

  19. Production of hydrogen from hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lohmueller, R

    1984-03-01

    Hydrocarbons are the preferred starting materials for the industrial production of hydrogen. Most hydrogen is produced by steam reforming of light hydrocarbons. Partial oxidation of heavy oil and residue is used for the production of H/sub 2/ and synthesis gas in large plants. In both cases gas purification was improved. Hydrogen-rich gases like coke oven gas, refinery-offgas, and offgases from the chemical and petrochemical industry have high potential for becoming a major source of hydrogen. Processes for recovering H/sub 2/ (and by-products) are condensation and rectification at low temperatures and, most attractive and versatile for the production of very pure H/sub 2/, adsorption (PSA). The environmental impact of H/sub 2/ production lies mainly in the emission of CO/sub 2/ and heat. Other forms of pollution can be considerably reduced by conventional methods. The economy of H/sub 2/ production depends essentially on price and availability of the raw materials.

  20. H/CNG pathway to hydrogen

    International Nuclear Information System (INIS)

    Bugyra, W.J.; Martin, D.R.

    2004-01-01

    'Full text:' The addition of hydrogen to natural gas to produce a 'premium' fuel offers an ideal bridge to the hydrogen and fuel cell era. This pathway provides many of the expected benefits of hydrogen and fuel cells, reduces cost and risk, and facilitates the transition to hydrogen incrementally through existing infrastructure, technologies and channels. The H/CNG pathway is evaluated qualitatively and quantitatively in the context of: barriers to introducing hydrogen infrastructure and how they can be addressed; potential benefits (emissions, energy security) and drawbacks (range, technical compatibility) of H/CNG blended fuels; economics; and, comparative analysis to the use of ethanol in gasoline. Leveraging the NGV industry eases the transition to fuel cells by taking advantage of existing infrastructure, technologies, skills, codes and standards, and provides for incremental change that may be more acceptable to consumers, regulators and incumbent technology providers. The greatest benefits can be achieved through a two-track pathway. One would utilize small amounts of hydrogen in existing NGVs and installed power systems - much as ethanol is added to gasoline. The second introduce products designed specifically to operate on higher levels of H/CNG, like buses, in concentrations where the greatest emission benefits can be achieved. (author)

  1. 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)

  2. LARGE-SCALE PRODUCTION OF HYDROGEN BY NUCLEAR ENERGY FOR THE HYDROGEN ECONOMY

    International Nuclear Information System (INIS)

    SCHULTZ, K.R.; BROWN, L.C.; BESENBRUCH, G.E.; HAMILTON, C.J.

    2003-01-01

    OAK B202 LARGE-SCALE PRODUCTION OF HYDROGEN BY NUCLEAR ENERGY FOR THE HYDROGEN ECONOMY. The ''Hydrogen Economy'' will reduce petroleum imports and greenhouse gas emissions. However, current commercial hydrogen production processes use fossil fuels and releases carbon dioxide. Hydrogen produced from nuclear energy could avoid these concerns. The authors have recently completed a three-year project for the US Department of Energy whose objective was to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the energy source''. Thermochemical water-splitting, a chemical process that accomplishes the decomposition of water into hydrogen and oxygen, met this objective. The goal of the first phase of this study was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen and to select one for further detailed consideration. The authors selected the Sulfur-Iodine cycle, In the second phase, they reviewed all the basic reactor types for suitability to provide the high temperature heat needed by the selected thermochemical water splitting cycle and chose the helium gas-cooled reactor. In the third phase they designed the chemical flowsheet for the thermochemical process and estimated the efficiency and cost of the process and the projected cost of producing hydrogen. These results are summarized in this paper

  3. Hydrogen transport behavior of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Hankins, M.R.; Longhurst, G.R.; Pawelko, R.J. (Idaho National Engineering Lab., EG and G Idaho, Inc., Idaho Falls, ID (United States)); Macaulay-Newcombe, R.G. (Dept. of Engineering Physics, Univ. Hamilton, ON (Canada))

    1992-12-01

    Beryllium is being evaluated for use as a plasma-facing material in the International Thermonuclear Experimental Reactor (ITER). One concern in the evaluation is the retention and permeation of tritium implanted into the plasma-facing surface. We performed laboratory-scale studies to investigate mechanisms that influence hydrogen transport and retention in beryllium foil specimens of rolled powder metallurgy product and rolled ingot cast beryllium. Specimen characterization was accomplished using scanning electron microscopy. Auger electron spectroscopy, and Rutherford backscattering spectrometry (RBS) techniques. Hydrogen transport was investigated using ion-beam permeation experiments and nuclear reaction analysis (NRA). Results indicate that trapping plays a significant role in permeation, re-emission, and retention, and that surface processes at both upstream and downstream surfaces are also important. (orig.).

  4. Membrane pumping technology, helium and hydrogen isotopes separation in the fusion hydrogen

    International Nuclear Information System (INIS)

    Pigarov, A.Yu.; Pistunovich, V.I.; Busnyuk, A.O.

    1994-01-01

    A gas pumping system for the ITER, improved by implementation of superpermeable membranes for selective hydrogen isotope exhaust, is considered. The study of the pumping capability of a niobium membrane for a hydrogen-helium mixture has been fulfilled. The membrane superpermeability can be only realized for atomic hydrogen. Helium does not pass through the membrane, and its presence does not affect the hydrogen pumping. A detailed Monte Carlo simulation of gas behavior for the experimental facility has been done. The probability of permeation for a hydrogen atom for one collision with the membrane is ∼0.1; the same probability of molecule permeation is ∼10 -5 . The probability for atomization, i.e. re-emission of an atomizer is ∼0.2; the probability of recombination of an atom is ∼0.2

  5. Investigation of hydrogen usage in aviation industry

    International Nuclear Information System (INIS)

    Yılmaz, İlker; İlbaş, Mustafa; Taştan, Murat; Tarhan, Cevahir

    2012-01-01

    Highlights: ► We examine usage of liquid hydrogen as a fuel in aircrafts. ► Engine performance is a little better for liquid hydrogen fuel than kerosene. ► Liquid hydrogen can be a potential alternative to kerosene as aviation fuel. ► Usage of liquid hydrogen will provide national independence for fuel supply. ► Increased production of liquid hydrogen will decrease its cost disadvantage. - Abstract: Fossil-based fuels are commonly used in aircraft engines but they have a polluting effect and they cause a greenhouse effect for our world. This study reports a research about aircraft gas turbine engines which are fired by liquid hydrogen (LH 2 ) in terms of performance and environmental aspects. Also, the performance and emissions of LH 2 fueled engines are compared with those of kerosene fired aircraft engines. Same flights from Istanbul to London, and Paris to Kabul are examined to estimate the emission from a conventional aircraft as an application in aviation sector. It is shown that the amount of NO x , HC and CO emissions for traveling by a conventional aircraft for London is 78.36, 1.202 and 22.4 kg, while Paris is 71.55, 1.171 and 21.63 kg, and Kabul is 111.44, 1.36 and 26.11 kg, respectively. For the use of liquid hydrogen as a fuel, amount of gas emissions decreases for any destination like London, Paris and Kabul. Total HC and CO emissions are going to be nearly 0 kg because of lack of carbon in the fuel. Also NO x emission is lower because of wider flammability limit of LH 2 . Results show that the aircraft engines with LH 2 have great potential for emissions reduction and engine performance parameters are a little better for LH 2 fuel. It is strongly emphasized that one of the most important advantages for the use of LH 2 is national independence for fuel supply. Oil cannot be extracted in every countries territory but LH 2 is producible for every country and this is so important for a countries freedom.

  6. French hydrogen markets in 2008-Overview and future prospects

    International Nuclear Information System (INIS)

    Le Duigou, A.; Amalric, Y.; Miguet, M.

    2011-01-01

    This study analyses the current industrial hydrogen markets in France on both a European and international scale, while endeavouring to assess future prospects by 2030. Hydrogen is produced either on purpose or unintentionally as a co-product. Intentional production of hydrogen, generally from natural gas, is classified as captive or merchant hydrogen. France produces about 920,000 metric tons of hydrogen annually. The producer and consumer industries are, in decreasing order of importance are: oil for refinery and petrochemicals, ammonia, iron and steel (co-production), chemicals, and chlorine (co-production). The intentional production of hydrogen from natural gas amounts to less than that co-produced: 40% compared with 60%. The amount of burned hydrogen is about 25% of the total. Production-related carbon dioxide emissions range between 1% and 2% of the total emissions in France. There is an increasing trend in the industrial hydrogen production, essentially due to the oil industry whereas a decline in production is expected in the ammonia industry. The annual production around 2030 should therefore be greater than 1 million metric tons (MMT) per year. If the iron and steel industry were to use hydrogen in every possible situation, it would double the total quantity of hydrogen produced and consumed in France. (authors)

  7. Acoustic emission

    International Nuclear Information System (INIS)

    Nichols, R.W.

    1976-01-01

    The volume contains six papers which together provide an overall review of the inspection technique known as acoustic emission or stress wave emission. The titles are: a welder's introduction to acoustic emission technology; use of acoustic emission for detection of defects as they arise during fabrication; examples of laboratory application and assessment of acoustic emission in the United Kingdom; (Part I: acoustic emission behaviour of low alloy steels; Part II: fatigue crack assessment from proof testing and continuous monitoring); inspection of selected areas of engineering structures by acoustic emission; Japanese experience in laboratory and practical applications of acoustic emission to welded structures; and ASME acoustic emission code status. (U.K.)

  8. 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.)

  9. Simulation of hydrogen and hydrogen-assisted propane ignition in Pt catalyzed microchannel

    Energy Technology Data Exchange (ETDEWEB)

    Seshadri, Vikram; Kaisare, Niket S. [Department of Chemical Engineering, Indian Institute of Technology - Madras, Chennai 600 036 (India)

    2010-11-15

    This paper deals with self-ignition of catalytic microburners from ambient cold-start conditions. First, reaction kinetics for hydrogen combustion is validated with experimental results from the literature, followed by validation of a simplified pseudo-2D microburner model. The model is then used to study the self-ignition behavior of lean hydrogen/air mixtures in a Platinum-catalyzed microburner. Hydrogen combustion on Pt is a very fast reaction. During cold start ignition, hydrogen conversion reaches 100% within the first few seconds and the reactor dynamics are governed by the ''thermal inertia'' of the microburner wall structure. The self-ignition property of hydrogen can be used to provide the energy required for propane ignition. Two different modes of hydrogen-assisted propane ignition are considered: co-feed mode, where the microburner inlet consists of premixed hydrogen/propane/air mixtures; and sequential feed mode, where the inlet feed is switched from hydrogen/air to propane/air mixtures after the microburner reaches propane ignition temperature. We show that hydrogen-assisted ignition is equivalent to selectively preheating the inlet section of the microburner. The time to reach steady state is lower at higher equivalence ratio, lower wall thermal conductivity, and higher inlet velocity for both the ignition modes. The ignition times and propane emissions are compared. Although the sequential feed mode requires slightly higher amount of hydrogen, the propane emissions are at least an order of magnitude lower than the other ignition modes. (author)

  10. Bodipy–C60 triple hydrogen bonding assemblies as heavy atom-free triplet photosensitizers: preparation and study of the singlet/triplet energy transfer† †Electronic supplementary information (ESI) available: Syntheses, structure characterization data, and UV/vis absorption and emission spectra. See DOI: 10.1039/c4sc03865g

    Science.gov (United States)

    Guo, Song; Xu, Liang; Xu, Kejing; Küçüköz, Betül; Karatay, Ahmet; Yaglioglu, Halime Gul; Hayvali, Mustafa; Elmali, Ayhan

    2015-01-01

    Supramolecular triplet photosensitizers based on hydrogen bonding-mediated molecular assemblies were prepared. Three thymine-containing visible light-harvesting Bodipy derivatives (B-1, B-2 and B-3, which show absorption at 505 nm, 630 nm and 593 nm, respectively) were used as H-bonding modules, and 1,6-diaminopyridine-appended C60 was used as the complementary hydrogen bonding module (C-1), in which the C60 part acts as a spin converter for triplet formation. Visible light-harvesting antennae with methylated thymine were prepared as references (B-1-Me, B-2-Me and B-3-Me), which are unable to form strong H-bonds with C-1. Triple H-bonds are formed between each Bodipy antenna (B-1, B-2 and B-3) and the C60 module (C-1). The photophysical properties of the H-bonding assemblies and the reference non-hydrogen bond-forming mixtures were studied using steady state UV/vis absorption spectroscopy, fluorescence emission spectroscopy, electrochemical characterization, and nanosecond transient absorption spectroscopy. Singlet energy transfer from the Bodipy antenna to the C60 module was confirmed by fluorescence quenching studies. The intersystem crossing of the latter produced the triplet excited state. The nanosecond transient absorption spectroscopy showed that the triplet state is either localized on the C60 module (for assembly B-1·C-1), or on the styryl-Bodipy antenna (for assemblies B-2·C-1 and B-3·C-1). Intra-assembly forward–backward (ping-pong) singlet/triplet energy transfer was proposed. In contrast to the H-bonding assemblies, slow triplet energy transfer was observed for the non-hydrogen bonding mixtures. As a proof of concept, these supramolecular assemblies were used as triplet photosensitizers for triplet–triplet annihilation upconversion. PMID:29218142

  11. 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.)

  12. Hydrogen enrichment of an internal combustion engine via closed loop thermochemical recuperation

    NARCIS (Netherlands)

    Zwitserlood, J.G.; Hofman, T.; Erickson, P.A.

    2013-01-01

    Hydrogen enrichment in an internal combustion engine can greatly improve efficiency and at the same time reduce emissions without the need for extensive engine modifications. One option for a hydrogen source for the enrichment is actively producing hydrogen on-board the vehicle through steam

  13. Hydrogen Macro System Model User Guide, Version 1.2.1

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, M.; Diakov, V.; Sa, T.; Goldsby, M.; Genung, K.; Hoseley, R.; Smith, A.; Yuzugullu, E.

    2009-07-01

    The Hydrogen Macro System Model (MSM) is a simulation tool that links existing and emerging hydrogen-related models to perform rapid, cross-cutting analysis. It allows analysis of the economics, primary energy-source requirements, and emissions of hydrogen production and delivery pathways.

  14. Advanced Hydrogen Turbine Development

    Energy Technology Data Exchange (ETDEWEB)

    Joesph Fadok

    2008-01-01

    Siemens has developed a roadmap to achieve the DOE goals for efficiency, cost reduction, and emissions through innovative approaches and novel technologies which build upon worldwide IGCC operational experience, platform technology, and extensive experience in G-class operating conditions. In Phase 1, the technologies and concepts necessary to achieve the program goals were identified for the gas turbine components and supporting technology areas and testing plans were developed to mitigate identified risks. Multiple studies were conducted to evaluate the impact in plant performance of different gas turbine and plant technologies. 2015 gas turbine technologies showed a significant improvement in IGCC plant efficiency, however, a severe performance penalty was calculated for high carbon capture cases. Thermodynamic calculations showed that the DOE 2010 and 2015 efficiency targets can be met with a two step approach. A risk management process was instituted in Phase 1 to identify risk and develop mitigation plans. For the risks identified, testing and development programs are in place and the risks will be revisited periodically to determine if changes to the plan are necessary. A compressor performance prediction has shown that the design of the compressor for the engine can be achieved with additional stages added to the rear of the compressor. Tip clearance effects were studied as well as a range of flow and pressure ratios to evaluate the impacts to both performance and stability. Considerable data was obtained on the four candidate combustion systems: diffusion, catalytic, premix, and distributed combustion. Based on the results of Phase 1, the premixed combustion system and the distributed combustion system were chosen as having the most potential and will be the focus of Phase 2 of the program. Significant progress was also made in obtaining combustion kinetics data for high hydrogen fuels. The Phase 1 turbine studies indicate initial feasibility of the

  15. Solar and Hydrogen

    International Nuclear Information System (INIS)

    Kadirgan, F.; Beyhan, S.; Oezenler, S.

    2006-01-01

    It has been widely accepted that the only sustainable and environmentally friendly energy is the solar energy and hydrogen energy, which can meet the increasing energy demand in the future. Solar Energy may be used either for solar thermal or for solar electricity conversion. Solar thermal collectors represent a wide-spread type of system for the conversion of solar energy. Radiation, convection and conduction are strongly coupled energy transport mechanisms in solar collector systems. The economic viability of lower temperature applications of solar energy may be improved by increasing the quantity of usable energy delivered per unit area of collector. This can be achieved by the use of selective black coatings which have a high degree of solar absorption, maintaining high energy input to the solar system while simultaneously suppressing the emission of thermal infrared radiation. Photovoltaic solar cells and modules are produced for: (1) large scale power generation, most commonly when modules are incorporated as part of a building (building integrated photovoltaic s) but also in centralised power stations, (2) supplying power to villages and towns in developing countries that are not connected to the supply grid, e.g. for lighting and water pumping systems, (3) supplying power in remote locations, e.g. for communications or weather monitoring equipment, (4) supplying power for satellites and space vehicles, (5) supplying power for consumer products, e.g. calculators, clocks, toys and night lights. In hydrogen energy systems, Proton exchange membrane (PEMFC) fuel cells are promising candidates for applications ranging from portable power sources (battery replacement applications) to power sources for future electric vehicles because of their safety, elimination of fuel processor system, thus, simple device fabrication and low cost. Although major steps forward have been achieved in terms of PEMFC design since the onset of research in this area, further

  16. 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...

  17. Emission line galaxies and active galactic nuclei in WINGS clusters

    Science.gov (United States)

    Marziani, P.; D'Onofrio, M.; Bettoni, D.; Poggianti, B. M.; Moretti, A.; Fasano, G.; Fritz, J.; Cava, A.; Varela, J.; Omizzolo, A.

    2017-03-01

    We present the analysis of the emission line galaxies members of 46 low-redshift (0.04 employing diagnostic diagrams. We examined the emission line properties and frequencies of star-forming galaxies, transition objects, and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified galaxies with emission lines, and quiescent galaxies with no detectable line emission. A deficit of emission line galaxies in the cluster environment is indicated by both a lower frequency, and a systematically lower Balmer emission line equivalent width and luminosity with respect to control samples; this implies a lower amount of ionized gas per unit mass and a lower star formation rate if the source is classified as Hii region. A sizable population of transition objects and of low-luminosity LINERs (≈ 10-20% of all emission line galaxies) are detected among WINGS cluster galaxies. These sources are a factor of ≈1.5 more frequent, or at least as frequent, as in control samples with respect to Hii sources. Transition objects and LINERs in clusters are most affected in terms ofline equivalent width by the environment and appear predominantly consistent with so-called retired galaxies. Shock heating can be a possible gas excitation mechanism that is able to account for observed line ratios. Specific to the cluster environment, we suggest interaction between atomic and molecular gas and the intracluster medium as a possible physical cause of line-emitting shocks. The data whose description is provided in Table B.1, and emission line catalog of the WINGS database are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A83

  18. Early forest fire detection using low-energy hydrogen sensors

    Directory of Open Access Journals (Sweden)

    K. Nörthemann

    2013-11-01

    Full Text Available Most huge forest fires start in partial combustion. In the beginning of a smouldering fire, emission of hydrogen in low concentration occurs. Therefore, hydrogen can be used to detect forest fires before open flames are visible and high temperatures are generated. We have developed a hydrogen sensor comprising of a metal/solid electrolyte/insulator/semiconductor (MEIS structure which allows an economical production. Due to the low energy consumption, an autarkic working unit in the forest was established. In this contribution, first experiments are shown demonstrating the possibility to detect forest fires at a very early stage using the hydrogen sensor.

  19. Optical and thermal energy discharge from tritiated solid hydrogen

    International Nuclear Information System (INIS)

    Magnotta, F.; Mapoles, E.R.; Collins, G.W.; Souers, P.C.

    1991-01-01

    The authors are investigating mechanisms of energy storage and release in tritiated solid hydrogens, by a variety of techniques including ESR, NMR and thermal and optical emission. The nuclear decay of a triton in solid hydrogen initiates the conversion of nuclear energy into stored chemical energy by producing unpaired hydrogen atoms which are trapped within the molecular lattice. The ability to store large quantities of atoms in this manner has been demonstrated and can serve as a basis for new forms of high energy density materials. This paper presents preliminary results of a study of the optical emission from solid hydrogen containing tritium over the visible and near infrared (NIR) spectral regions. Specifically, they have studied optical emission from DT and T 2 using CCD, silicon diode and germanium diode arrays. 8 refs., 6 figs

  20. A prediction study of a spark ignition supercharged hydrogen engine

    International Nuclear Information System (INIS)

    Al-Baghdadi, Maher A.R. Sadiq.; Al-Janabi, Haroun A.K. Shahad

    2003-01-01

    Hydrogen is found to be a suitable alternative fuel for spark ignition engines with certain drawbacks, such as high NO x emission and small power output. However, supercharging may solve such problems. In this study, the effects of equivalence ratio, compression ratio and inlet pressure on the performance and NO x emission of a four stroke supercharged hydrogen engine have been analyzed using a specially developed computer program. The results are verified and compared with experimental data obtained from tests on a Ricardo E6/US engine. A chart specifying the safe operation zone of the hydrogen engine has been produced. The safe operation zone means no pre-ignition, acceptable NO x emission, high engine efficiency and lower specific fuel consumption in comparison with the gasoline engine. The study also shows that supercharging is a more effective method to increase the output of a hydrogen engine rather than increasing the compression ratio of the engine at the knock limited equivalence ratio

  1. 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

  2. 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-.

  3. 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

  4. 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.

  5. 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 ...

  6. Energetic and economic evaluations on hydrogen storage technologies

    Energy Technology Data Exchange (ETDEWEB)

    Arca, S.; Di Profio, P.; Germani, R. [Perugia Univ., Perugia (Italy). Centro di Eccellenza Materiali Innovativi Nanostrutturati, Dip. Chimica; Savelli, G.; Cotana, F.; Rossi, F.; Amantini, M. [Universita degli Studi di Perugia, Perugia (Italy). Dipartimento di Ingegneria Industriale, Sezione di Fisica Tecnica

    2008-07-01

    With the development of the hydrogen economy and fuel cell vehicles, a major technological issue has emerged regarding the storage and delivery of large amounts of hydrogen. Several hydrogen storage methodologies are available while other technologies are being developed aside from the classical compression and liquefaction of hydrogen. A novel technology is also in rapid process, which is based on clathrate hydrates of hydrogen. The features and performances of available storage systems were evaluated in an effort to determine the best technology throughout the hydrogen chain. For each of the storage solutions presented, the key parameters were compared. These key parameters included interaction energy between hydrogen and support; real and practical storage capacity; and specific energy consumption. The paper presented the study methods and discussed hydrogen storage technologies using compressed hydrogen; metal hydrides; liquefied hydrogen; carbon nanotubes; ammonia; and gas hydrates. Carbon dioxide emissions were also evaluated for each storage system analyzed. The paper also presented the worst scenario. It was concluded that a technology based on clathrate hydrates of hydrogen, while being far from optimized, was highly competitive with the classical approaches. 21 refs., 9 figs.

  7. Nuclear hydrogen: An assessment of product flexibility and market viability

    International Nuclear Information System (INIS)

    Botterud, Audun; Yildiz, Bilge; Conzelmann, Guenter; Petri, Mark C.

    2008-01-01

    Nuclear energy has the potential to play an important role in the future energy system as a large-scale source of hydrogen without greenhouse gas emissions. Thus far, economic studies of nuclear hydrogen tend to focus on the levelized cost of hydrogen without accounting for the risks and uncertainties that potential investors would face. We present a financial model based on real options theory to assess the profitability of different nuclear hydrogen production technologies in evolving electricity and hydrogen markets. The model uses Monte Carlo simulations to represent uncertainty in future hydrogen and electricity prices. It computes the expected value and the distribution of discounted profits from nuclear hydrogen production plants. Moreover, the model quantifies the value of the option to switch between hydrogen and electricity production, depending on what is more profitable to sell. We use the model to analyze the market viability of four potential nuclear hydrogen technologies and conclude that flexibility in output product is likely to add significant economic value for an investor in nuclear hydrogen. This should be taken into account in the development phase of nuclear hydrogen technologies

  8. Proceedings of the 14. world hydrogen energy conference 2002 : The hydrogen planet. CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    Venter, R.D.; Bose, T.K. [Quebec Univ., Trois-Rivieres, PQ (Canada). Institut de recherche sur l' hydrogene; Veziroglu, N. [International Association for Hydrogen Energy, Coral Gables, FL (United States)] (eds.)

    2002-07-01

    Hydrogen has often been named as the ultimate fuel because it can be generated from a variety of renewable and non-renewable fuels and its direct conversion to electricity in fuel cells is efficient and results in no emissions other than water vapour. The opportunities and issues associated with the use of hydrogen as the energy carrier of the future were presented at this conference which addressed all aspects of hydrogen and fuel cell development including hydrogen production, storage, hydrogen-fuelled internal combustion engines, hydrogen infrastructure, economics, and the environment. Hydrogen is currently used as a chemical feedstock and a space fuel, but it is receiving considerable attention for bring renewable energy into the transportation and power generation sectors with little or no environmental impact at the point of end use. Canada leads the way in innovative ideas for a hydrogen infrastructure, one of the most challenging tasks for the transportation sector along with hydrogen storage. Major vehicle manufacturers have announced that they will have hydrogen-fueled cars and buses on the market beginning in 2003 and 2004. Solid oxide fuel cells will be used for generating electricity with efficiencies of 70 per cent, and proton exchange membrane (PEM) and other fuel cells are being tested for residential power supply with efficiencies of 85 per cent. The conference included an industrial exposition which demonstrated the latest developments in hydrogen and fuel cell research. More than 300 papers were presented at various oral and poster sessions, of which 172 papers have been indexed separately for inclusion in the database.

  9. 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

  10. 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.

  11. 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

  12. The potential role of hydrogen energy in India and Western Europe

    International Nuclear Information System (INIS)

    Ruijven, Bas van; Hari, Lakshmikanth; Vuuren, Detlef P. van; Vries, Bert de

    2008-01-01

    We used the TIMER energy model to explore the potential role of hydrogen in the energy systems of India and Western Europe, looking at the impacts on its main incentives: climate policy, energy security and urban air pollution. We found that hydrogen will not play a major role in both regions without considerable cost reductions, mainly in fuel cell technology. Also, energy taxation policy is essential for hydrogen penetration and India's lower energy taxes limit India's capacity to favour hydrogen. Once available to the (European) energy system, hydrogen can decrease the cost of CO 2 emission reduction by increasing the potential for carbon capture technology. However, climate policy alone is insufficient to speed up the transition. Hydrogen diversifies energy imports; especially for Europe it decreases oil imports, while increasing imports of coal and natural gas. For India, it provides an opportunity to decrease oil imports and use indigenous coal resources in the transport sector. Hydrogen improves urban air quality by shifting emissions from urban transport to hydrogen production facilities. However, for total net emissions we found a sensitive trade-off between lower emissions at end-use (in transport) and higher emissions from hydrogen production, depending on local policy for hydrogen production facilities

  13. Hydrogen energy - the end of the beginning

    International Nuclear Information System (INIS)

    Stuart, A. K.

    1997-01-01

    Financial barriers to the widespread use of hydrogen energy were the principal messages contained in this banquet address. These barriers include the cost for the hydrogen, cost for the supply infrastructure and the cost of developing and building the special vehicles and appliances to use hydrogen. Some hopeful signs that hydrogen energy is emerging include Ballard's buses, early fuel cell private vehicle refueling station and remote energy systems which will be commercialized within the next ten years. The optimism is based on the effects of deregulation of the electric utility industry in the US now spreading to Canada and other countries, the appearance of effective direct hydrogen fuel cell vehicles under strong industrial sponsorship, and the near-term availability of electrolysis for hydrogen production at a fraction of present capital cost. Each of these reasons for optimism were elaborated in some detail. However, the main force behind the hydrogen solution for transportation is the environmental benefit, i.e. the potential of some one billion automobiles around the world running on an environmentally benign fuel, and the potential effect of that fact on global warming. The likely effects of continuing as before is no longer considered a viable option even by the greatest of skeptics of greenhouse gas emissions, a fact that will make the demand for 'clean' vehicles progressively more pressing with the passage of time. By increasing the hydrogen-to-carbon ratio in upgrading heavy hydrocarbons, the petroleum industry itself is showing the way to factor global warming issues into process choices. By going one step further and obtaining the hydrogen from non-fossil sources, the environmental benefits will be multiplied several fold

  14. Hydrogen Storage Technologies for Future Energy Systems.

    Science.gov (United States)

    Preuster, Patrick; Alekseev, Alexander; Wasserscheid, Peter

    2017-06-07

    Future energy systems will be determined by the increasing relevance of solar and wind energy. Crude oil and gas prices are expected to increase in the long run, and penalties for CO 2 emissions will become a relevant economic factor. Solar- and wind-powered electricity will become significantly cheaper, such that hydrogen produced from electrolysis will be competitively priced against hydrogen manufactured from natural gas. However, to handle the unsteadiness of system input from fluctuating energy sources, energy storage technologies that cover the full scale of power (in megawatts) and energy storage amounts (in megawatt hours) are required. Hydrogen, in particular, is a promising secondary energy vector for storing, transporting, and distributing large and very large amounts of energy at the gigawatt-hour and terawatt-hour scales. However, we also discuss energy storage at the 120-200-kWh scale, for example, for onboard hydrogen storage in fuel cell vehicles using compressed hydrogen storage. This article focuses on the characteristics and development potential of hydrogen storage technologies in light of such a changing energy system and its related challenges. Technological factors that influence the dynamics, flexibility, and operating costs of unsteady operation are therefore highlighted in particular. Moreover, the potential for using renewable hydrogen in the mobility sector, industrial production, and the heat market is discussed, as this potential may determine to a significant extent the future economic value of hydrogen storage technology as it applies to other industries. This evaluation elucidates known and well-established options for hydrogen storage and may guide the development and direction of newer, less developed technologies.

  15. Configuration and technology implications of potential nuclear hydrogen system applications.

    Energy Technology Data Exchange (ETDEWEB)

    Conzelmann, G.; Petri, M.; Forsberg, C.; Yildiz, B.; ORNL

    2005-11-05

    Nuclear technologies have important distinctions and potential advantages for large-scale generation of hydrogen for U.S. energy services. Nuclear hydrogen requires no imported fossil fuels, results in lower greenhouse-gas emissions and other pollutants, lends itself to large-scale production, and is sustainable. The technical uncertainties in nuclear hydrogen processes and the reactor technologies needed to enable these processes, as well waste, proliferation, and economic issues must be successfully addressed before nuclear energy can be a major contributor to the nation's energy future. In order to address technical issues in the time frame needed to provide optimized hydrogen production choices, the Nuclear Hydrogen Initiative (NHI) must examine a wide range of new technologies, make the best use of research funding, and make early decisions on which technology options to pursue. For these reasons, it is important that system integration studies be performed to help guide the decisions made in the NHI. In framing the scope of system integration analyses, there is a hierarchy of questions that should be addressed: What hydrogen markets will exist and what are their characteristics? Which markets are most consistent with nuclear hydrogen? What nuclear power and production process configurations are optimal? What requirements are placed on the nuclear hydrogen system? The intent of the NHI system studies is to gain a better understanding of nuclear power's potential role in a hydrogen economy and what hydrogen production technologies show the most promise. This work couples with system studies sponsored by DOE-EE and other agencies that provide a basis for evaluating and selecting future hydrogen production technologies. This assessment includes identifying commercial hydrogen applications and their requirements, comparing the characteristics of nuclear hydrogen systems to those market requirements, evaluating nuclear hydrogen configuration options

  16. THE LICK AGN MONITORING PROJECT: REVERBERATION MAPPING OF OPTICAL HYDROGEN AND HELIUM RECOMBINATION LINES

    International Nuclear Information System (INIS)

    Bentz, Misty C.; Walsh, Jonelle L.; Barth, Aaron J.; Thornton, Carol E.; Yoshii, Yuzuru; Sakata, Yu; Minezaki, Takeo; Woo, Jong-Hak; Malkan, Matthew A.; Wang, Xiaofeng; Steele, Thea N.; Silverman, Jeffrey M.; Serduke, Frank J. D.; Li, Weidong; Lee, Nicholas; Treu, Tommaso; Street, Rachel A.; Hidas, Marton G.; Hiner, Kyle D.; Greene, Jenny E.

    2010-01-01

    We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3 m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z 6 -10 7 M sun and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hβ emission, which we have previously reported. We present here the light curves for the Hα, Hγ, He II λ4686, and He I λ5876 emission lines and the time lags for the emission-line responses relative to changes in the continuum flux. Combining each emission-line time lag with the measured width of the line in the variable part of the spectrum, we determine a virial mass of the central supermassive black hole from several independent emission lines. We find that the masses are generally consistent within the uncertainties. The time-lag response as a function of velocity across the Balmer line profiles is examined for six of the AGNs. We find similar responses across all three Balmer lines for Arp 151, which shows a strongly asymmetric profile, and for SBS 1116+583A and NGC 6814, which show a symmetric response about zero velocity. For the other three AGNs, the data quality is somewhat lower and the velocity-resolved time-lag response is less clear. Finally, we compare several trends seen in the data set against the predictions from photoionization calculations as presented by Korista and Goad. We confirm several of their predictions, including an increase in responsivity and a decrease in the mean time lag as the excitation and ionization level for the species increases. Specifically, we find the time lags of the optical recombination lines to have weighted mean ratios of τ(Hα):τ(Hβ):τ(Hγ):τ(He I):τ(He II) = 1

  17. 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.

  18. Comparison of the performance of a spark-ignited gasoline engine blended with hydrogen and hydrogen-oxygen mixtures

    International Nuclear Information System (INIS)

    Wang, Shuofeng; Ji, Changwei; Zhang, Jian; Zhang, Bo

    2011-01-01

    This paper compared the effects of hydrogen and hydrogen-oxygen blends (hydroxygen) additions on the performance of a gasoline engine at 1400 rpm and a manifolds absolute pressure of 61.5 kPa. The tests were carried out on a 1.6 L gasoline engine equipped with a hydrogen and oxygen injection system. A hybrid electronic control unit was applied to adjust the hydrogen and hydroxygen volume fractions in the intake increasing from 0% to about 3% and keep the hydrogen-to-oxygen mole ratio at 2:1 in hydroxygen tests. For each testing condition, the gasoline flow rate was adjusted to maintain the mixture global excess air ratio at 1.00. The test results confirmed that engine fuel energy flow rate was decreased after hydrogen addition but increased with hydroxygen blending. When hydrogen or hydroxygen volume fraction in the intake was lower than 2%, the hydroxygen-blended gasoline engine produced a higher thermal efficiency than the hydrogen-blended gasoline engine. Both the additions of hydrogen and hydroxygen help reduce flame development and propagation periods of the gasoline engine. HC emissions were reduced whereas NOx emissions were raised with the increase of hydrogen and hydroxygen addition levels. CO was slightly increased after hydrogen blending, but reduced with hydroxygen addition. -- Highlights: → We compared the effects of hydrogen and hydroxygen additions on the gasoline engine performance. → The hydroxygen should be added into the engine only at low blending levels. → CO is decreased with hydroxygen addition whereas increased with hydrogen blending.

  19. Precision measurement of the 1S Lamb shift in atomic hydrogen

    International Nuclear Information System (INIS)

    Beausoleil, R.G.; McIntyre, D.H.; Foot, C.J.; Couillaud, B.; Hildum, E.A.; Hansch, T.W.

    1987-01-01

    The authors used cw Doppler-free two-photon spectroscopy to measure the 1S-2S transition frequency in atomic hydrogen gas with a precision of 6 parts in 10 10 . Their result for the energy level separation is f(1S-2S) = 2 466 061 413.3(1.5) MHz and can be used to extract a value of the 1S Lamb shift. Choosing a value of the Rydberg constant measured independently by high-resolution spectroscopy of the hydrogen Balmer-β transition, the authors obtain a value of Δf/sub Lamb/(1S) = 8 173.3(1.7) MHz, in good agreement with the theoretical prediction of 8 173.06(20) MHz. On the other hand, if they trust the theoretical determination of the 1S Lamb shift, they can interpret our experimental result as a measurement of the Rydberg constant. The authors obtain R∞ = 109 737.315(7) cm -1 , in agreement with recent precise measurements

  20. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    Energy Technology Data Exchange (ETDEWEB)

    H.Y. Sohn

    2008-03-31

    The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

  1. 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.

  2. Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    Directory of Open Access Journals (Sweden)

    Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    2016-07-01

    Full Text Available Hydrogen fuel is a good alternative to fossil fuels. It can be produced using a clean energy without contaminated emissions. This work is concerned with experimental study on hydrogen production via solar energy. Photovoltaic module is used to convert solar radiation to electrical energy. The electrical energy is used for electrolysis of water into hydrogen and oxygen by using alkaline water electrolyzer with stainless steel electrodes. A MATLAB computer program is developed to solve a four-parameter-model and predict the characteristics of PV module under Baghdad climate conditions. The hydrogen production system is tested at different NaOH mass concentration of (50,100, 200, 300 gram. The maximum hydrogen production rate is 153.3 ml/min, the efficiency of the system is 20.88% and the total amount of hydrogen produced in one day is 220.752 liter.

  3. Donor level of interstitial hydrogen in GaAs

    International Nuclear Information System (INIS)

    Dobaczewski, L.; Bonde Nielsen, K.; Nylandsted Larsen, A.; Peaker, A.R.

    2006-01-01

    The first data evidencing the existence of the donor level of the interstitial hydrogen in GaAs are presented. The abundant formation of the (0/+) donor level after in situ low-temperature implantation of hydrogen into the depletion layer of GaAs Schottky diodes has been observed and the activation energy and annealing properties have been determined by Laplace DLTS. The activation energy for electron emission of this donor state is 0.14eV. Above 100K the hydrogen deep donor state is unstable, converting to a more stable form when there are electrons available for the capture process. A slightly perturbed form of the hydrogen donor in its neutral charge state can be recovered by illuminating the sample. This process releases twice as many electrons as the ionisation process of the hydrogen donor state itself. This fact, by analogy with the silicon case, evidences the negative-U behaviour of hydrogen in GaAs

  4. Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

    Science.gov (United States)

    Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

    2015-01-01

    Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

  5. Towards a hydrogen-driven society? Calculations and neutron scattering on potential hydrogen storage materials

    NARCIS (Netherlands)

    Schimmel, H.G.

    2005-01-01

    For sustainable development, the resources of the earth need to be maintained and carbon dioxide emission should be avoided. In particular, we need to find an alternative for the use of fossil fuels in vehicles. Since long, hydrogen has been recognised as the fuel of the future because it exhausts

  6. 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.

  7. 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)

  8. 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.

  9. Electrolytic production and dispensing of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

    1995-09-01

    The fuel cell electric vehicle (FCEV) is undoubtedly the only option that can meet both the California zero emission vehicle (ZEV) standard and the President`s goal of tripling automobile efficiency without sacrificing performance in a standard 5-passenger vehicle. The three major automobile companies are designing and developing FCEVs powered directly by hydrogen under cost-shared contracts with the Department of Energy. Once developed, these vehicles will need a reliable and inexpensive source of hydrogen. Steam reforming of natural gas would produce the least expensive hydrogen, but funding may not be sufficient initially to build both large steam reforming plants and the transportation infrastructure necessary to deliver that hydrogen to geographically scattered FCEV fleets or individual drivers. This analysis evaluates the economic feasibility of using small scale water electrolysis to provide widely dispersed but cost-effective hydrogen for early FCEV demonstrations. We estimate the cost of manufacturing a complete electrolysis system in large quantities, including compression and storage, and show that electrolytic hydrogen could be cost competitive with fully taxed gasoline, using existing residential off-peak electricity rates.

  10. Development of hydrogen production technology using FBR

    International Nuclear Information System (INIS)

    Ono, Kiyoshi; Otaki, Akira; Chikazawa, Yoshitaka; Nakagiri, Toshio; Sato, Hiroyuki; Sekine, Takashi; Ooka, Makoto

    2004-06-01

    This report describes the features of technology, the schedule and the organization for the research and development regarding the hydrogen production technology using FBR thermal energy. Now, the hydrogen production system is proposed as one of new business models for FBR deployment. This system is the production of hydrogen either thermal energy at approximately from 500degC to 550degC or electricity produced by a sodium cooled FBR. Hydrogen is expected to be one of the future clean secondary energies without carbon-dioxide emission. Meanwhile the global energy demand will increase, especially in Asian countries, and the energy supply by fossil fuels is not the best choice considering the green house effect and the stability of energy supply. The development of the hydrogen technology using FBR that satisfies 'sustainable energy development' and 'utilization of energies free from environmental pollution' will be one of the promising options. Based on the above mentioned recognition, we propose the direction of the development, the issues to be solved, the time schedule, the budget, and the organization for R and D of three hydrogen production technologies, the thermochemical hybrid process, the low temperature steam reforming process, and the high temperature steam electrolysis process in JNC. (author)

  11. A strategy for introducing hydrogen into transportation

    International Nuclear Information System (INIS)

    Farrell, A.E.; Keith, D.W.; Corbett, J.J.

    2003-01-01

    Considerable effort is being expended on research and demonstration projects aimed at introducing hydrogen into the transportation sector as a fuel, generally motivated by concerns about carbon dioxide emissions and petroleum imports (or scarcity). In this paper we focus on one aspect of strategy for introducing hydrogen--the choice of transportation mode. Our analysis suggests that cost of introducing hydrogen can be reduced by selecting a mode that uses a small number of relatively large vehicles that are operated by professional crews along a limited number of point-to-point routes or within a small geographic area. In addition, technological innovation in vehicle design will take place most quickly in modes where individual vehicles are produced to order and each receives significant engineering attention (not those manufactured in vast quantities on assembly lines). The immediate environmental benefits of introducing hydrogen fuel will occur in modes that have relatively less stringent pollution regulations applied to them. These insights, suggest that heavy-duty freight modes would be a less costly way to introduce hydrogen as a transportation fuel and a more effective way to advance hydrogen-related technologies so that they could subsequently be used more widely in light-duty vehicles

  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. Hydrogen Sensors Boost Hybrids; Today's Models Losing Gas?

    Science.gov (United States)

    2005-01-01

    Advanced chemical sensors are used in aeronautic and space applications to provide safety monitoring, emission monitoring, and fire detection. In order to fully do their jobs, these sensors must be able to operate in a range of environments. NASA has developed sensor technologies addressing these needs with the intent of improving safety, optimizing combustion efficiencies, and controlling emissions. On the ground, the chemical sensors were developed by NASA engineers to detect potential hydrogen leaks during Space Shuttle launch operations. The Space Shuttle uses a combination of hydrogen and oxygen as fuel for its main engines. Liquid hydrogen is pumped to the external tank from a storage tank located several hundred feet away. Any hydrogen leak could potentially result in a hydrogen fire, which is invisible to the naked eye. It is important to detect the presence of a hydrogen fire in order to prevent a major accident. In the air, the same hydrogen-leak dangers are present. Stress and temperature changes can cause tiny cracks or holes to form in the tubes that line the Space Shuttle s main engine nozzle. Such defects could allow the hydrogen that is pumped through the nozzle during firing to escape. Responding to the challenges associated with pinpointing hydrogen leaks, NASA endeavored to improve propellant leak-detection capabilities during assembly, pre-launch operations, and flight. The objective was to reduce the operational cost of assembling and maintaining hydrogen delivery systems with automated detection systems. In particular, efforts have been focused on developing an automated hydrogen leak-detection system using multiple, networked hydrogen sensors that are operable in harsh conditions.

  16. Hydrogen Programs of Asian Countries

    International Nuclear Information System (INIS)

    Ken-ichiro OTA

    2006-01-01

    The global sustainability is a key word of the future energy system for human beings. It should be friendly to the earth and also to human beings. Considering the limit of resources, the materials recycling would be very important. Considering the second law of thermodynamics, the entropy production through any processes would be the final problems for the sustainable growth. We have to think how to dispose the increasing entropy outside earth in the clean energy system. At present, the global carbon cycle is changing by the emission of CO 2 with the large consumption of fossil fuels. The global environment including human society should stand on harmonizing with the earth, where the global recycles of materials are important. Thinking about the global recycles of carbon and water quantitatively, the existence of water is 27,000 times larger than that of carbon. The transportation of water is 3,160 times faster than that of carbon. These figures show that the hydrogen from water is a superior energy carrier, compared to the carbon. The environmental impact factor was defined as the ratio of annual quantity of materials produced by energy consumption of mankind to a natural movement on earth. The influence of human activities on the global environment can be evaluated quantitatively by this environmental impact factor. The environmental impact factor of water on the earth, 0.0001, is more than two orders of magnitude less than that of carbon, 0.036. This means the hydrogen/water cycle is superior to the carbon cycle as material circulation for energy system of mankind. The energy consumption will increase tremendously in Asian countries due to their population increase and economic growth. We need a clean energy system for the sustainable growth. The hydrogen energy system is the most suitable energy system. In this paper the recent hydrogen energy programs of Japan, China and Korea will be introduced. (authors)

  17. Hydrogen Programs of Asian Countries

    International Nuclear Information System (INIS)

    Ken-ichiro Ota

    2006-01-01

    The global sustainability is a key word of the future energy system for human beings. It should be friendly to the earth and also to human beings. Considering the limit of resources, the materials recycling would be very important. Considering the second law of thermodynamics, the entropy production through any processes would be the final problems for the sustainable growth. We have to think how to dispose the increasing entropy outside earth in the clean energy system. At present, the global carbon cycle is changing by the emission of CO 2 with the large consumption of fossil fuels. The global environment including human society should stand on harmonizing with the earth, where the global recycles of materials are important. Thinking about the global recycles of carbon and water quantitatively, the existence of water is 27,000 times larger than that of carbon. The transportation of water is 3,160 times faster than that of carbon. These figures show that the hydrogen from water is a superior energy carrier, compared to the carbon. The environmental impact factor was defined as the ratio of annual quantity of materials produced by energy consumption of mankind to a natural movement on earth. The influence of human activities on the global environment can be evaluated quantitatively by this environmental impact factor. The environmental impact factor of water on the earth, 0.0001, is more than two orders of magnitude less than that of carbon, 0.036. This means the hydrogen/water cycle is superior to the carbon cycle as material circulation for energy system of mankind. The energy consumption will increase tremendously in Asian countries due to their population increase and economic growth. We need a clean energy system for the sustainable growth. The hydrogen energy system is the most suitable energy system. In this paper the recent hydrogen energy programs of Japan, China and Korea will be introduced. (author)

  18. Low-CO(2) electricity and hydrogen: a help or hindrance for electric and hydrogen vehicles?

    Science.gov (United States)

    Wallington, T J; Grahn, M; Anderson, J E; Mueller, S A; Williander, M I; Lindgren, K

    2010-04-01

    The title question was addressed using an energy model that accounts for projected global energy use in all sectors (transportation, heat, and power) of the global economy. Global CO(2) emissions were constrained to achieve stabilization at 400-550 ppm by 2100 at the lowest total system cost (equivalent to perfect CO(2) cap-and-trade regime). For future scenarios where vehicle technology costs were sufficiently competitive to advantage either hydrogen or electric vehicles, increased availability of low-cost, low-CO(2) electricity/hydrogen delayed (but did not prevent) the use of electric/hydrogen-powered vehicles in the model. This occurs when low-CO(2) electricity/hydrogen provides more cost-effective CO(2) mitigation opportunities in the heat and power energy sectors than in transportation. Connections between the sectors leading to this counterintuitive result need consideration in policy and technology planning.

  19. An evolutionary perspective on the immunomodulatory role of hydrogen sulphide.

    Science.gov (United States)

    Rivers-Auty, J

    2015-11-01

    Most preclinical studies on endogenous hydrogen sulphide signalling have given little consideration to the fact that the human body contains more bacterial cells than human cells, and that evolution provides the context for all biology. Whether hydrogen sulphide is pro or anti-inflammatory is heavily debated within the literature, yet researchers have not fully considered that invasive bacteria produce hydrogen sulphide, often at levels far above the endogenous levels of the host. Here I argue that if hydrogen sulphide is an endogenous signalling molecule with immunomodulatory functions, then it must have evolved in the presence of virulent bacteria which produce hydrogen sulphide. This context leads to two competing theories about the evolution of endogenous hydrogen sulphide signalling. The detectable emission theory proposes that bacteria produce hydrogen sulphide as part of normal metabolism and hosts which evolved to detect and respond to this hydrogen sulphide would gain a selective survival advantage. This predicts that the endogenous production of hydrogen sulphide is a mechanism which amplifies the bacterial hydrogen sulphide signal. The opposing protective agent theory predicts that bacterial hydrogen sulphide is an effective defence against the bactericidal mechanisms of the host's immune response. In this case, endogenous hydrogen sulphide production is either at inconsequential levels to alter the immune response, or is involved in the inflammation resolution process. Evidence suggests that the direct interactions of hydrogen sulphide with the bactericidal mechanisms of the innate immune system are most congruent with the protective agent theory. Therefore, I argue that if hydrogen sulphide is an immunomodulatory endogenous signalling molecule its effects are most likely anti-inflammatory. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Hydrogen demonstration projects options in the Netherlands. Final report

    International Nuclear Information System (INIS)

    Bergsma, G.C.; Van der Werff, T.T.; Rooijers, F.J.

    1996-01-01

    Based on a survey of hydrogen demonstration projects, contacts with different actors and discussions in a sounding board for the study on the title subject, it is concluded that a conference can be organized where the possibilities of setting up hydrogen demonstration projects in the Netherlands can be discussed. The following projects offer good chances to be realized in the next few years: large-scale CO 2 storage in the underground, applying enhanced gas recovery. It appears to be a relatively cheap CO 2 emission reduction measure with a large potential. It can be combined with a hydrogen mixing project with the sale of hydrogen as a so-called eco-gas to consumers. There is little interest in the other options for CO 2 storage at coal gasification and the prompt supply of 100% H 2 to small-scale consumers. Hydrogen for cogeneration, fuel cells in the industry, hydrogen in road transport and hydrogen as a storage medium are projects in which some actors are interested. Hydrogen for air transport has a large potential to which only few parties in the Netherlands can anticipate. Hydrogen demonstration projects will show important surplus value when it is supported by a hydrogen research program. Such a program can be carried out in cooperation with several other programmes of the International Energy Agency, in Japan, Germany and a number of research programs of the Netherlands Agency for Energy and the Environment (Novem). 10 figs., 4 tabs., 33 refs

  1. 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)

  2. 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

  3. 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.

  4. 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)

  5. 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

  6. 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

  7. IUE observations of circumstellar emission from the late-type variable R AQR (M6 + pec)

    Science.gov (United States)

    Hobbs, R. W.; Michalitsianos, A. G.; Kafatos, M.

    1981-01-01

    The IUE observations of R Aqr (M7 + pec) obtained in low dispersion are discussed with particular reference to circumstellar emission. Strong permitted, semiforbidden, and forbidden emission lines are seen, superimposed on a bright ultraviolet continuum. It is deduced that the strong emission line spectrum that involves C III, C IV, Si III, (0 II) and (0 III) probably arises from a dense compact nebula the size of which is comparable to the orbital radius of the binary system of which R Aqr is the primary star. The low excitation emission lines of Fe II, Mg II, 0 I, and Si II probably a white dwarf, comparable to or somewhat brighter than the Sun, since such a star can produce enough ionizing photons to excite the continuum and emission line spectrum and yet be sufficiently faint as to escape detection by direct observation. The UV continuum is attributed to Balmer recombination from the dense nebula and not to blackbody emission from the hot companion.

  8. A RADIAL VELOCITY TEST FOR SUPERMASSIVE BLACK HOLE BINARIES AS AN EXPLANATION FOR BROAD, DOUBLE-PEAKED EMISSION LINES IN ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jia; Halpern, Jules P. [Astronomy Department, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Eracleous, Michael [Department of Astronomy and Institute for Gravitation and The Cosmos, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2016-01-20

    One of the proposed explanations for the broad, double-peaked Balmer emission lines observed in the spectra of some active galactic nuclei (AGNs) is that they are associated with sub-parsec supermassive black hole (SMBH) binaries. Here, we test the binary broad-line region hypothesis through several decades of monitoring of the velocity structure of double-peaked Hα emission lines in 13 low-redshift, mostly radio-loud AGNs. This is a much larger set of objects compared to an earlier test by Eracleous et al. and we use much longer time series for the three objects studied in that paper. Although systematic changes in radial velocity can be traced in many of their lines, they are demonstrably not like those of a spectroscopic binary in a circular orbit. Any spectroscopic binary period must therefore be much longer than the span of the monitoring (assuming a circular orbit), which in turn would require black hole masses that exceed by 1–2 orders of magnitude the values obtained for these objects using techniques such as reverberation mapping and stellar velocity dispersion. Moreover, the response of the double-peaked Balmer line profiles to fluctuations of the ionizing continuum and the shape of the Lyα profiles are incompatible with an SMBH binary. The binary broad-line region hypothesis is therefore disfavored. Other processes evidently shape these line profiles and cause the long-term velocity variations of the double peaks.

  9. Lifecycle impacts of natural gas to hydrogen pathways on urban air quality

    International Nuclear Information System (INIS)

    Wang, Guihua; Ogden, Joan M.; Nicholas, Michael A.

    2007-01-01

    In this paper we examine the potential air quality impacts of hydrogen transportation fuel from a lifecycle analysis perspective, including impacts from fuel production, delivery, and vehicle use. We assume that hydrogen fuel cell vehicles are introduced in a specific region, Sacramento County, California. We consider two levels of market penetration where 9% or 20% of the light duty fleet are hydrogen fuel cell vehicles. The following three natural gas to hydrogen supply pathways are assessed in detail and compared in terms of emissions and the resulting changes in ambient air quality: (1) onsite hydrogen production; (2) centralized hydrogen production with gaseous hydrogen pipeline delivery systems; and (3) centralized hydrogen production with liquid hydrogen truck delivery systems. All the pathways examined use steam methane reforming (SMR) of natural gas to produce hydrogen. The source contributions to incremental air pollution are estimated and compared among hydrogen pathways. All of the hydrogen pathways result in extremely low contributions to ambient air concentrations of NO x , CO, particulates, and SO x , typically less than 0.1% of the current ambient pollution for both levels of market penetration. Among the hydrogen supply options, it is found that the central SMR with pipeline delivery systems is the lowest pollution option available provided the plant is located to avoid transport of pollutants into the city via prevailing winds. The onsite hydrogen pathway is comparable to the central hydrogen pathway with pipeline systems in terms of the resulting air pollution. The pathway with liquid hydrogen trucks has a greater impact on air quality relative to the other pathways due to emissions associated with diesel trucks and electricity consumption to liquefy hydrogen. However, all three hydrogen pathways result in negligible air pollution in the region. (author)

  10. The use of hydrogen for vehicles

    International Nuclear Information System (INIS)

    Peschka, W.

    1992-01-01

    While the currently utilized or other feasible hydrocarbon fuels release about the same amount of CO 2 during combustion per amount of heat produced, hydrogen represents the only practical, technically feasible, carbon free fuel. The state of the art technology of liquid hydrogen represents a suitable base for large scale demonstration projects now. Additional aims of more intense R and D work relate to internal mixture formation and improved engine roadability as well as utility vehicle application including trucks and buses. With respect to fuel costs there will be an increased demand in developing hydrogen production processes free from CO 2 emissions even from fossil energy sources such as crude oil or natural gas. (orig.) [de

  11. Hydrogen storage properties of metallic hydrides

    International Nuclear Information System (INIS)

    Latroche, M.; Percheron-Guegan, A.

    2005-01-01

    Nowadays, energy needs are mainly covered by fossil energies leading to pollutant emissions mostly responsible for global warming. Among the different possible solutions for greenhouse effect reduction, hydrogen has been proposed for energy transportation. Indeed, H 2 can be seen as a clean and efficient energy carrier. However, beside the difficulties related to hydrogen production, efficient high capacity storage means are still to be developed. Many metals and alloys are able to store large amounts of hydrogen. This latter solution is of interest in terms of safety, global yield and long term storage. However, to be suitable for applications, such compounds must present high capacity, good reversibility, fast reactivity and sustainability. In this paper, we will review the structural and thermodynamic properties of metallic hydrides. (authors)

  12. Seasonal storage and alternative carriers: A flexible hydrogen supply chain model

    International Nuclear Information System (INIS)

    Reuß, M.; Grube, T.; Robinius, M.; Preuster, P.; Wasserscheid, P.; Stolten, D.

    2017-01-01

    Highlights: •Techno-economic model of future hydrogen supply chains. •Implementation of liquid organic hydrogen carriers into a hydrogen mobility analysis. •Consideration of large-scale seasonal storage for fluctuating renewable hydrogen production. •Implementation of different technologies for hydrogen storage and transportation. -- Abstract: A viable hydrogen infrastructure is one of the main challenges for fuel cells in mobile applications. Several studies have investigated the most cost-efficient hydrogen supply chain structure, with a focus on hydrogen transportation. However, supply chain models based on hydrogen produced by electrolysis require additional seasonal hydrogen storage capacity to close the gap between fluctuation in renewable generation from surplus electricity and fuelling station demand. To address this issue, we developed a model that draws on and extends approaches in the literature with respect to long-term storage. Thus, we analyse Liquid Organic Hydrogen Carriers (LOHC) and show their potential impact on future hydrogen mobility. We demonstrate that LOHC-based pathways are highly promising especially for smaller-scale hydrogen demand and if storage in salt caverns remains uncompetitive, but emit more greenhouse gases (GHG) than other gaseous or hydrogen ones. Liquid hydrogen as a seasonal storage medium offers no advantage compared to LOHC or cavern storage since lower electricity prices for flexible operation cannot balance the investment costs of liquefaction plants. A well-to-wheel analysis indicates that all investigated pathways have less than 30% GHG-emissions compared to conventional fossil fuel pathways within a European framework.

  13. 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...

  14. Internal combustion engines fueled by natural gas-hydrogen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Akansu, S.O.; Kahraman, N. [Erciyes University, Kayseri (Turkey). Engineering Faculty; Dulger, Z. [Kocaeli University (Turkey). Engineering Faculty; Veziroglu, T.N. [University of Miami, Coral Gables, FL (United States). College of Engineering

    2004-11-01

    In this study, a survey of research papers on utilization of natural gas-hydrogen mixtures in internal combustion engines is carried out. In general, HC, CO{sub 2}, and CO emissions decrease with increasing H{sub 2}, but NO{sub x} emissions generally increase. If a catalytic converter is used, NO{sub x} emission values can be decreased to extremely low levels. Consequently, equivalence zero emission vehicles (EZEV) standards may be reached. Efficiency values vary with H{sub 2} amount, spark timing, compression ratio, equivalence ratio, etc. Under certain conditions, efficiency values can be increased. In terms of BSFC, emissions and BTE, a mixture of low hydrogen percentage is suitable for using. (author)

  15. 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

  16. Biological hydrogen production from biomass by thermophilic bacteria

    International Nuclear Information System (INIS)

    Claassen, P.A.M.; Mars, A.E.; Budde, M.A.W.; Lai, M.; de Vrije, T.; van Niel, E.W.J.

    2006-01-01

    To meet the reduction of the emission of CO 2 imposed by the Kyoto protocol, hydrogen should be produced from renewable primary energy. Besides the indirect production of hydrogen by electrolysis using electricity from renewable resources, such as sunlight, wind and hydropower, hydrogen can be directly produced from biomass. At present, there are two strategies for the production of hydrogen from biomass: the thermochemical technology, such as gasification, and the biotechnological approach using micro-organisms. Biological hydrogen production delivers clean hydrogen with an environmental-friendly technology and is very suitable for the conversion of wet biomass in small-scale applications, thus having a high chance of becoming an economically feasible technology. Many micro-organisms are able to produce hydrogen from mono- and disaccharides, starch and (hemi)cellulose under anaerobic conditions. The anaerobic production of hydrogen is a common phenomenon, occurring during the process of anaerobic digestion. Here, hydrogen producing micro-organisms are in syn-trophy with methanogenic bacteria which consume the hydrogen as soon as it is produced. In this way, hydrogen production remains obscure and methane is the end-product. By uncoupling hydrogen production from methane production, hydrogen becomes available for recovery and exploitation. This study describes the use of extreme thermophilic bacteria, selected because of a higher hydrogen production efficiency as compared to mesophilic bacteria, for the production of hydrogen from renewable resources. As feedstock energy crops like Miscanthus and Sorghum bicolor and waste streams like domestic organic waste, paper sludge and potato steam peels were used. The feedstock was pretreated and/or enzymatically hydrolyzed prior to fermentation to make a fermentable substrate. Hydrogen production by Caldicellulosiruptor saccharolyticus, Thermotoga elfii and T. neapolitana on all substrates was observed. Nutrient

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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...

  2. Optical characteristics of a RF DBD plasma jet in various A r / O 2 ...

    Indian Academy of Sciences (India)

    Using the optical emission spectrum analysis of the RF plasma jet, the excitation temperature is determined based on the Boltzmann plot method. The electron density in the plasma medium of the RF plasma jet is obtained by the Stark broadening of the hydrogen Balmer H β . It is mostly seen that, the radiation intensity of Ar ...

  3. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this

  4. Hydrogen hybrid vehicle engine development: Experimental program

    Energy Technology Data Exchange (ETDEWEB)

    Van Blarigan, P. [Sandia National Lab., Livermore, CA (United States)

    1995-09-01

    A hydrogen fueled engine is being developed specifically for the auxiliary power unit (APU) in a series type hybrid vehicle. Hydrogen is different from other internal combustion (IC) engine fuels, and hybrid vehicle IC engine requirements are different from those of other IC vehicle engines. Together these differences will allow a new engine design based on first principles that will maximize thermal efficiency while minimizing principal emissions. The experimental program is proceeding in four steps: (1) Demonstration of the emissions and the indicated thermal efficiency capability of a standard CLR research engine modified for higher compression ratios and hydrogen fueled operation. (2) Design and test a new combustion chamber geometry for an existing single cylinder research engine, in an attempt to improve on the baseline indicated thermal efficiency of the CLR engine. (3) Design and build, in conjunction with an industrial collaborator, a new full scale research engine designed to maximize brake thermal efficiency. Include a full complement of combustion diagnostics. (4) Incorporate all of the knowledge thus obtained in the design and fabrication, by an industrial collaborator, of the hydrogen fueled engine for the hybrid vehicle power train illustrator. Results of the CLR baseline engine testing are presented, as well as preliminary data from the new combustion chamber engine. The CLR data confirm the low NOx produced by lean operation. The preliminary indicated thermal efficiency data from the new combustion chamber design engine show an improvement relative to the CLR engine. Comparison with previous high compression engine results shows reasonable agreement.

  5. Molecular hydrogen jets from the Orion nebula

    International Nuclear Information System (INIS)

    Taylor, K.N.R.; Storey, J.W.V.; Zealey, W.J.

    1984-01-01

    In an attempt to understand the relationship of the recently discovered complex of Herbig Haro objects in Orion to the IR sources in this region, the authors have carried out a survey of the molecular hydrogen S(1) line distribution. The observations have led to the discovery of a previously unsuspected structure of finger-like filaments of H 2 emission extending radially outwards from a common centre at IRC9. (author)

  6. Dust clouds in Orion and the interstellar neutral hydrogen distribution

    International Nuclear Information System (INIS)

    Bystrova, N.V.

    1989-01-01

    According to published examples of the far IR observations in the Orion and its surroundings, several well defined dust clouds of different sizes and structure are present. For comparison of these clouds with the neutral hydrogen distribution on the area of approx. 1000 sq degs, the data from Pulkovo Sky Survey in the interstellar neutral Hydrogen Radio Line as well as special observations with the RATAN-600 telescope in 21 cm line were used. From the materials of Pulkovo HI Survey, the data were taken near the line emission at ten velocities between -21.8 and +25.6 km/s LSR for the structural component of the interstellar hydrogen emission. The results given concern mainly the Orion's Great Dust Cloud and the Lambda Orionis region where the information about the situation with the dust and interstellar hydrogen is very essential for interpretation

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.)

  15. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  16. 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.

  17. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

    Fontelle, J.P. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1997-12-31

    Statistics on air pollutant (sulfur dioxide, nitrogen oxides and ammonium) emissions, acid equivalent emissions and their evolution since 1990 in the various countries of Europe and the USA, are presented. Emission data from the industrial, agricultural, transportation and power sectors are given, and comparisons are carried out between countries based on Gnp and population, pollution import/export fluxes and compliance to the previous emission reduction objectives

  18. 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

  19. Systems analysis on the condition of market penetration for hydrogen technologies using linear programming model

    International Nuclear Information System (INIS)

    Kato, K.; Ihara, S.

    1993-01-01

    Hydrogen is expected to be an important energy carrier, especially in the frame of global warming problem solution. The purpose of this study is to examine the condition of market penetration of hydrogen technologies in reducing CO 2 emissions. A multi-time-period linear programming model (MARKAL, Market Allocation)) is used to explore technology options and cost for meeting the energy demands while reducing CO 2 emissions from energy systems. The results show that hydrogen technologies become economical when CO 2 emissions are stringently constrained. 9 figs., 2 refs