Sample records for helium hydrogen sulfide

  1. Guidance Document Safe Handling of Sulfides and Hydrogen Sulfide

    E-Print Network [OSTI]

    sulfide gas. At high levels, hydrogen sulfide may paralyze the lungs, prohibiting a victim from escaping

  2. Geothermal hydrogen sulfide removal

    SciTech Connect (OSTI)

    Urban, P.

    1981-04-01T23:59:59.000Z

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  3. REVISED HYDROGEN SULFIDE DRILLING CONTINGENCY PLAN

    E-Print Network [OSTI]

    REVISED HYDROGEN SULFIDE DRILLING CONTINGENCY PLAN OCEAN DRILLING PROGRAM TEXAS A&M UNIVERSITY;PREFACE Attached is the "REVISED HYDROGEN SULFIDE DRILLING CONTINGENCY PLAN" that will be used for ODP coring and drilling operations on legs where hydrogen sulfide is likely to be encountered. Prior

  4. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOE Patents [OSTI]

    Agarwal, Pradeep K.

    2007-01-16T23:59:59.000Z

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  5. CODE OF PRACTICE HYDROGEN SULFIDE

    E-Print Network [OSTI]

    Machel, Hans

    thus make it non-detectable. Hydrogen sulfide is very quickly absorbed into the lungs. Short term exposure may cause irritation of nose, throat, eyes and lungs. The Alberta Occupational Exposure Limit (O, possible nausea, tearing of the eyes or headaches with prolonged exposure. 20 ­ 50 Nose, throat and lung

  6. Hydrogen Sulfide in Drinking Water: Causes and Treatment Alternatives

    E-Print Network [OSTI]

    McFarland, Mark L.; Provin, Tony

    1999-06-15T23:59:59.000Z

    If drinking water has a nuisance "rotten egg odor, it contains hydrogen sulfide. This leaflet discusses how hydrogen sulfide is formed and how the problem can be corrected....

  7. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOE Patents [OSTI]

    Harkness, John B. L. (Naperville, IL); Gorski, Anthony J. (Woodridge, IL); Daniels, Edward J. (Oak Lawn, IL)

    1993-01-01T23:59:59.000Z

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  8. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOE Patents [OSTI]

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18T23:59:59.000Z

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  9. Hydrogen and Sulfur Production from Hydrogen Sulfide Wastes

    E-Print Network [OSTI]

    Harkness, J.; Doctor, R. D.

    A new hydrogen sulfide waste-treatment process that uses microwave plasma-chemical technology is currently under development in the Soviet Union and in the United States. Whereas the present waste treatment process only recovers sulfur at best...

  10. HYDROGEN SULFIDE -HIGH TEMPERATURE DRILLING CONTINGENCY PLAN

    E-Print Network [OSTI]

    HYDROGEN SULFIDE - HIGH TEMPERATURE DRILLING CONTINGENCY PLAN OCEAN DRILLING PROGRAM TEXAS A&M UNIVERSITY Technical Note 16 Steven P. Howard Ocean Drilling Program Texas A&M University 1000 Discovery Drive College Station, TX 77845-9547 Daniel H. Reudelhuber Ocean Drilling Program Texas A&M University

  11. Process for producing hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a heteropolyanionic metal complex catalyst

    SciTech Connect (OSTI)

    Kuch, Ph. L.

    1984-12-18T23:59:59.000Z

    Hydrogen and carbonyl sulfide are produced by a process comprising contracting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a heteropolymolybdate or tungstate complex. Use of these catalysts reduce the amount of by-product carbon dioxide and methane formation and thus enhance the make of hydrogen and carbonyl sulfide.

  12. High temperature regenerable hydrogen sulfide removal agents

    DOE Patents [OSTI]

    Copeland, Robert J. (Wheat Ridge, CO)

    1993-01-01T23:59:59.000Z

    A system for high temperature desulfurization of coal-derived gases using regenerable sorbents. One sorbent is stannic oxide (tin oxide, SnO.sub.2), the other sorbent is a metal oxide or mixed metal oxide such as zinc ferrite (ZnFe.sub.2 O.sub.4). Certain otherwise undesirable by-products, including hydrogen sulfide (H.sub.2 S) and sulfur dioxide (SO.sub.2) are reused by the system, and elemental sulfur is produced in the regeneration reaction. A system for refabricating the sorbent pellets is also described.

  13. Method of washing hydrogen sulfide from coke oven gas by the ammonium sulfide method

    SciTech Connect (OSTI)

    Ritter, H.

    1985-05-21T23:59:59.000Z

    An improved coke oven gas washing process for removing hydrogen sulfide is proposed wherein the coke oven gas is treated in a hydrogen sulfide scrubber by counterflow with an aqueous ammonia wash water. A stream of aqueous weak ammonia liquor is cooled and sprayed through nozzles in the mid-region of the hydrogen sulfide scrubber. A quantity of aqueous ammonia liquor, corresponding to the quantity which is sprayed through the said nozzles, is withdrawn from the hydrogen sulfide scrubber at a level below the nozzles and is introduced into the top of the said hydrogen sulfide scrubber. Ammonia vapor released at the nozzles has a higher partial pressure than the ammonia partial pressure of the coke oven gas in the region of the nozzle. The aqueous ammonia liquor from the deacidifier is the source of the cooled aqueous ammonia liquor which is introduced through the nozzles. A portion of the aqueous ammonia liquor from the deacidifier is introduced directly into the top of the hydrogen sulfide scrubber as a portion of the required aqueous ammonia wash water.

  14. Muon transfer from hydrogen to helium

    SciTech Connect (OSTI)

    Bystritskii, V.M.; Dzhelepov, V.P.; Petrukhin, V.I.; Rudenko, A.I.; Suvorov, V.M.; Filchenkov, V.V.; Khovanskii, N.N.; Khomenko, B.A.

    1983-04-01T23:59:59.000Z

    It is found that ..mu../sup -/ mesons stopped in a gas mixture of hydrogen, helium, and xenon (hydrogen pressure about 20 atmospheres, helium and xenon densities relative to hydrogen 0.05--2 and approx.10/sup -4/ respectively) are transferred from the p..mu.. atoms in the ground state to helium atoms at a rate lambda/sub He/ = (3.6 +- 1.0)x10/sup 8/ sec/sup -1/. The result is in good agreement with the calculations in which a novel mesic-molecular mechanism of p..mu..-atom charge exchange with helium nuclei is taken into account. The dependence of the probability for p..mu..-atom formation in the ground state on the helium density is measured. An analysis of this dependence and a comparison of it with the corresponding data for ..pi../sup -/ mesons indicate that muons can also be transferred from excited levels of p..mu.. atoms at a rate higher than in the case of p..pi.. atoms (transfer constant ..lambda../sub ..mu../ = 3.8 +- 0.3 compared with ..lambda../sub ..pi../ = 1.84 +- 0.09).

  15. Process for the production of hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a multi-metal oxide/sulfide catalyst

    SciTech Connect (OSTI)

    Jevnikar, M. G.; Kuch, Ph. L.

    1985-02-19T23:59:59.000Z

    Hydrogen and carbonyl sulfide are produced by a process comprising contacting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a catalytic composition containing an oxide and/or sulfide of at least one of molybdenum, tungsten, iron, chromium and vanadium in combination with at least one promoter metal, e.g. a catalyst of the formula Cs Cu /SUB 0.2/ Zn /SUB 0.5/ Mn /SUB 0.5/ Sn /SUB 2.4/ Mo O /SUB x/ S /SUB y/ .

  16. Method for removing hydrogen sulfide from coke oven gas

    SciTech Connect (OSTI)

    Ritter, H.

    1982-08-03T23:59:59.000Z

    An improved sulfur-ammonia process is disclosed for removing hydrogen sulfide from coke oven gases. In the improved process, a concentrator formerly used for standby operation is used at all normal times as an ammonia scrubber to improve the efficiency of gas separation during normal operation and is used as a concentrator for its intended standby functions during the alternative operations. In its normal function, the concentrator/scrubber functions as a scrubber to strip ammonia gas from recirculating liquid streams and to permit introduction of an ammonia-rich gas into a hydrogen sulfide scrubber to increase the separation efficiency of that unit. In the standby operation, the same concentrator/scrubber serves as a concentrator to concentrate hydrogen sulfide in a ''strong liquor'' stream for separate recovery as a strong liquor.

  17. Regenerable hydrogen chloride removal sorbent and regenerable multi-functional hydrogen sulfide and hydrogen chloride removal sorbent for high temperature gas streams

    DOE Patents [OSTI]

    Siriwardane, Ranjani (Morgantown, WV)

    2010-08-03T23:59:59.000Z

    Regenerable hydrogen chloride removal sorbent and regenerable multi-functional hydrogen sulfide and hydrogen chloride removal sorbent for high temperature gas streams

  18. The Modular Helium Reactor for Hydrogen Production

    SciTech Connect (OSTI)

    E. Harvego; M. Richards; A. Shenoy; K. Schultz; L. Brown; M. Fukuie

    2006-10-01T23:59:59.000Z

    For electricity and hydrogen production, an advanced reactor technology receiving considerable international interest is a modular, passively-safe version of the high-temperature, gas-cooled reactor (HTGR), known in the U.S. as the Modular Helium Reactor (MHR), which operates at a power level of 600 MW(t). For hydrogen production, the concept is referred to as the H2-MHR. Two concepts that make direct use of the MHR high-temperature process heat are being investigated in order to improve the efficiency and economics of hydrogen production. The first concept involves coupling the MHR to the Sulfur-Iodine (SI) thermochemical water splitting process and is referred to as the SI-Based H2-MHR. The second concept involves coupling the MHR to high-temperature electrolysis (HTE) and is referred to as the HTE-Based H2-MHR.

  19. Kinetic study of hydrogen sulfide absorption in aqueous chlorine solution

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    rate. To design, optimize and scale-up scrubbers, knowledge of the reaction kinetics and mechanism-1 s-1 ). Keywords Hydrogen sulfide, chlorine, kinetics, mass transfer, absorption, scrubber located at the bottom of the scrubber and is recirculated. pH and chlorine concentration are regulated

  20. L-Cysteine, Hydrogen Sulfide, and Insulin Signaling in Diabetes

    E-Print Network [OSTI]

    Shyamasundar, R.K.

    L-Cysteine, Hydrogen Sulfide, and Insulin Signaling in Diabetes Prasenjit Manna LSU Health Sciences Center Diabetes has become an epidemic and remains a major public health issue worldwide. of L in diabetic animal studies. However, the molecular mechanism by which LC increases glucose utilization

  1. Compact hydrogen/helium isotope mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

    1996-01-01T23:59:59.000Z

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  2. Process for removing hydrogen sulfide from gases particularly coal pyrolysis gases

    SciTech Connect (OSTI)

    Ritter, H.; Herpers, E.T.

    1985-02-12T23:59:59.000Z

    Hydrogen sulfide is first removed by ammoniacal liquor from coke oven gas in the bottom part of a gas scrubber. In the top part of the scrubber, two consecutively-arranged fine scrubbing stages remove hydrogen sulfide by treating the gases, in the upper stage, with a caustic soda solution or a caustic potash solution. Beneath the upper scrubbing stage is the second fine scrubbing stage fed with a subflow of an aqueous carbonate solution collecting at the outlet of the upper fine scrubbing stage and a subflow of cooled, regenerated carbonate solution discharged from the hydrogen-sulfide/hydrogen-cyanide stripper. From the hydrogen-sulfide/hydrogen-cyanide stripper, a second subflow is admixed with coal liquor for removing fixed ammonia therefrom in a separator. The separator produces water vapor with carbon dioxide vapors that are delivered to the hydrogen-sulfide/hydrogen-cyanide stripper for regenerating the aqueous carbonate washing solution.

  3. Effects of Hydrogen Sulfide on the Performance of a PEMFC R. Mohtadi,a,

    E-Print Network [OSTI]

    Van Zee, John W.

    October 7, 2003. In a ``hydrogen challenged'' economy, the fuel for proton ex- change membrane fuel cellsEffects of Hydrogen Sulfide on the Performance of a PEMFC R. Mohtadi,a, * W.-k. Lee,a, ** S. Cowan-products, such as carbon monoxide, ammonia, and hydrogen sulfide. While it is well known that H2S severely poisons Pt

  4. The selective adsorption of hydrogen sulfide from natural gas streams

    E-Print Network [OSTI]

    Fails, James Clayton

    1959-01-01T23:59:59.000Z

    of hydrogen sulfide. However, with its larger capillaries it also adsorbs more carbon dioxide. The Molecular S1eve f15-X is a new modificat1on of the sodium-substituted alumina-silicate. It approaches a cubic crystal. Details have not been released... act. alumina) + 90oF 80 +001 0 ' 0016 Atmospheric Pressure Tests on Activated Alumina (F-1) 26 42 +013 0. 094 0@0072 0 ' 14 e0097 ~ 0090 ~ 025 . 014 ~ 033 ~ 037 ~ 011 F 011 +Silica gel type adsorbent with modified act. alumina added. (See...

  5. Re-Condensation and Liquefaction of Helium and Hydrogen Using Coolers

    E-Print Network [OSTI]

    Green, Michael A.

    2010-01-01T23:59:59.000Z

    AND LIQUEFACTION OF HELIUM AND HYDROGEN USING COOLERS M. A.liquefaction for helium and hydrogen can occur. KEYWORDS:each contain a liquid hydrogen absorber [4] that is cooled

  6. Catalysts for the selective oxidation of hydrogen sulfide to sulfur

    DOE Patents [OSTI]

    Srinivas, Girish (Thornton, CO); Bai, Chuansheng (Baton Rouge, LA)

    2000-08-08T23:59:59.000Z

    This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

  7. A study of the reactions of arsinic and arsonic acids with hydrogen sulfide and hydrogen selenide

    E-Print Network [OSTI]

    Applegate, Cynthia Annette

    1986-01-01T23:59:59.000Z

    -diarsa-2, 3, 5-triselenacyclopentane 35 Bond angles in 1, 4&ipheny1-1, 4-diarsa-2, 3, 5-triselenacyclopentane 79 80 INTRODUCTION Many arsenic sulfides occur naturally in the form of minerals due to the natural affinity of arsenic and sulfur for one... another [I]. Arsemc trisulfide, As, S, an orange or yellow powder, is found in nature as the mineral orpiment. Arsenic trisulfide can be prepared by passing a stream of hydrogen sulfide through an acidic solution of arsenic trioxide. Arsenic disulfide...

  8. Methods for producing hydrogen (BI) sulfide and/or removing metals

    DOE Patents [OSTI]

    Truex, Michael J [Richland, WA; Peyton, Brent M [Pullman, WA; Toth, James J [Kennewick, WA

    2002-05-14T23:59:59.000Z

    The present invention is a process wherein sulfide production by bacteria is efficiently turned on and off, using pH adjustment. The adjustment of pH impacts sulfide production by bacteria by altering the relative amounts of H.sub.2 S and HS-- in solution and thereby control the inhibition of the bacterial metabolism that produces sulfide. This process can be used to make a bioreactor produce sulfide "on-demand" so that the production of sulfide can be matched to its use as a metal precipitation reagent. The present invention is of significance because it enables the use of a biological reactor, a cost effective sulfide production system, by making the biological reactor produce hydrogen sulfide "on demand", and therefore responsive to production schedules, waste stream generation rate, and health and safety requirements/goals.

  9. PULSATIONS IN HYDROGEN BURNING LOW-MASS HELIUM WHITE DWARFS

    SciTech Connect (OSTI)

    Steinfadt, Justin D. R. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States); Bildsten, Lars [Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States); Arras, Phil, E-mail: jdrs@physics.ucsb.ed, E-mail: bildsten@kitp.ucsb.ed, E-mail: arras@virginia.ed [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States)

    2010-07-20T23:59:59.000Z

    Helium core white dwarfs (WDs) with mass M {approx}< 0.20 M {sub sun} undergo several Gyr of stable hydrogen burning as they evolve. We show that in a certain range of WD and hydrogen envelope masses, these WDs may exhibit g-mode pulsations similar to their passively cooling, more massive carbon/oxygen core counterparts, the ZZ Cetis. Our models with stably burning hydrogen envelopes on helium cores yield g-mode periods and period spacings longer than the canonical ZZ Cetis by nearly a factor of 2. We show that core composition and structure can be probed using seismology since the g-mode eigenfunctions predominantly reside in the helium core. Though we have not carried out a fully nonadiabatic stability analysis, the scaling of the thermal time in the convective zone with surface gravity highlights several low-mass helium WDs that should be observed in search of pulsations: NLTT 11748, SDSS J0822+2753, and the companion to PSR J1012+5307. Seismological studies of these He core WDs may prove especially fruitful, as their luminosity is related (via stable hydrogen burning) to the hydrogen envelope mass, which eliminates one model parameter.

  10. Metal?organic frameworks for the storage and delivery of biologically active hydrogen sulfide

    SciTech Connect (OSTI)

    Allan, Phoebe K.; Wheatley, Paul S.; Aldous, David; Mohideen, M. Infas; Tang, Chiu; Hriljac, Joseph A.; Megson, Ian L.; Chapman, Karena W.; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E. (St Andrews)

    2012-04-02T23:59:59.000Z

    Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis.

  11. Mitigation of hydrogen sulfide emissions in The Geysers KGRA

    SciTech Connect (OSTI)

    Buell, R.

    1981-07-01T23:59:59.000Z

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H/sub 2/S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H/sub 2/S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H/sub 2/S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staff's efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H/sub 2/S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to be promising, cost-effective control options.

  12. The solubility of elemental sulfur in methane, carbon dioxide and hydrogen sulfide gas

    E-Print Network [OSTI]

    Wieland, Denton R.

    1958-01-01T23:59:59.000Z

    ABSTRACT The object of the work reported In this dissertation was to determine the solubility of sulfur in gaseous methane carbon dioxide, and hydrogen sulfide and in mixtures of these gases, at various pressures and temperatures* Sulfur solubility... of methane and propane (which has a critical pressure of approximately the same value of hydrogen sulfide) is 1500 psia. To have liquid in this system at 1500 psia, however, would require a maximum temperature of 20?F which is well below the minimum...

  13. Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect (OSTI)

    Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

    2007-09-30T23:59:59.000Z

    The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

  14. Updated cost estimates of meeting geothermal hydrogen sulfide emission regulations

    SciTech Connect (OSTI)

    Wells, K.D.; Currie, J.W.; Weakley, S.A.; Ballinger, M.Y.

    1981-08-01T23:59:59.000Z

    A means of estimating the cost of hydrogen sulfide (H/sub 2/S) emission control was investigated. This study was designed to derive H/sub 2/S emission abatement cost functions and illustrate the cost of H/sub 2/S emission abatement at a hydrothermal site. Four tasks were undertaken: document the release of H/sub 2/S associated with geothermal development; review H/sub 2/S environmental standards; develop functional relationships that may be used to estimate the most cose-effective available H/sub 2/S abatement process; and use the cost functions to generate abatement cost estimates for a specific site. The conclusions and recommendations derived from the research are presented. The definition of the term impacts as used in this research is discussed and current estimates of the highest expected H/sub 2/S concentrations of in geothermal reservoirs are provided. Regulations governing H/sub 2/S emissions are reviewed and a review of H/sub 2/S control technology and a summary of the control cost functions are included. A case study is presented to illustrate H/sub 2/S abatement costs at the Baca KGRA in New Mexico.

  15. Two phase coexistence for the hydrogen-helium mixture

    E-Print Network [OSTI]

    Fantoni, Riccardo

    2015-01-01T23:59:59.000Z

    We use our newly constructed quantum Gibbs ensemble Monte Carlo algorithm to perform computer experiments for the two phase coexistence of a hydrogen-helium mixture. Our results are in quantitative agreement with the experimental results of C. M. Sneed, W. B. Streett, R. E. Sonntag, and G. J. Van Wylen. The difference between our results and the experimental ones is in all cases less than 15% relative to the experiment, reducing to less than 5% in the low helium concentration phase. At the gravitational inversion between the vapor and the liquid phase, at low temperatures and high pressures, the quantum effects become relevant. At extremely low temperature and pressure the first component to show superfluidity is the helium in the vapor phase.

  16. Journal of Power Sources 135 (2004) 184191 A solid oxide fuel cell system fed with hydrogen sulfide

    E-Print Network [OSTI]

    2004-01-01T23:59:59.000Z

    Journal of Power Sources 135 (2004) 184­191 A solid oxide fuel cell system fed with hydrogen for a solid oxide fuel cell (SOFC). This paper presents an examination of a simple hydrogen sulfide and natural gas-fed solid oxide fuel cell system. The possibility of utilization of hydrogen sulfide

  17. Direct chlorination process for geothermal power plant off-gas - hydrogen sulfide abatement

    SciTech Connect (OSTI)

    Sims, A.V.

    1983-06-01T23:59:59.000Z

    The Direct Chlorination Process removes hydrogen sulfide from geothermal off-gases by reacting hydrogen sulfide with chlorine in the gas phase. Hydrogen chloride and elemental sulfur are formed by this reaction. The Direct Chlorination Process has been successfully demonstrated by an on-site operation of a pilot plant at the 3 M We HPG-A geothermal power plant in the Puna District on the island of Hawaii. Over 99.5 percent hydrogen sulfide removal was achieved in a single reaction state. Chlorine gas did not escape the pilot plant, even when 90 percent excess chlorine gas was used. A preliminary economic evaluation of the Direct Chlorination Process indicates that it is very competitive with the Stretford Process. Compared to the Stretford Process, the Direct Chlorination Process requires about one-third the initial capital investment and about one-fourth the net daily expenditure.

  18. Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous

    E-Print Network [OSTI]

    Deng, Baolin

    experiments with excess [Cr(VI)] over [H2S]T indicated that the molar amount of sulfide required for the reduction of 1 M Cr(VI) was 1.5, suggesting the following stoichi- ometry: 2CrO4 2- + 3H2S + 4H+ f 2Cr(OH)3 of fully protonated sulfide (H2S) in the pH range of 6.5-10. The nature of buffers did not influence

  19. Hydrogen and helium entrapment in flowing liquid metal plasma-facing surfaces

    E-Print Network [OSTI]

    Harilal, S. S.

    Hydrogen and helium entrapment in flowing liquid metal plasma-facing surfaces Ahmed Hassanein the PFC surface (helium and hydrogen isotopes) while accommodating high heat loads. To study this problem. Hydrogen isotope (DT) particles are likely be trapped in the liquid metal surface (e.g., lithium) due

  20. Modeling hydrogen and helium entrapment in flowing liquid metal surfaces as plasma-facing components in

    E-Print Network [OSTI]

    Harilal, S. S.

    Modeling hydrogen and helium entrapment in flowing liquid metal surfaces as plasma the PFC surface (helium and hydrogen isotopes) while accommodating high heat loads. To study this problem rather than requiring a standard vacuum system. Hydrogen isotope (DT) particles that strike the surface

  1. Production of carbon monoxide-free hydrogen and helium from a high-purity source

    DOE Patents [OSTI]

    Golden, Timothy Christopher (Allentown, PA); Farris, Thomas Stephen (Bethlehem, PA)

    2008-11-18T23:59:59.000Z

    The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

  2. Removal of hydrogen sulfide from waste treatment plant biogas using the apollo scrubber

    SciTech Connect (OSTI)

    Smith, J.W.; Burrowes, P.A.; Gupta, A.; Walton, P.S.; Meffe, S.

    1996-12-31T23:59:59.000Z

    The removal of hydrogen sulfide and other sulphur compounds from anaerobic digester gas streams prior to their use as fuel for boilers, stationary engines, and cogeneration units minimizes corrosion problems and reduces sulfur emission loadings. A research program at the Department of Chemical Engineering and Applied Chemistry, University of Toronto in the 1980`s demonstrated the use of a modified flotation cell for the absorption of hydrogen sulfide from a gas stream and its catalytic oxidation to sulfur. The essence of the technology was a proprietary gas liquid contactor which provided very high mass transfer rates at the interface. A bench scale contactor developed at the university achieved hydrogen sulfide removal efficiencies of over 99.9% at atmospheric pressure. A demonstration unit for digester gas scrubbing applications was designed, fabricated, and then installed and evaluated at the Metropolitan Toronto Works Department - Main Treatment Plant (MTP).

  3. Hydrogen and helium traces in type Ib-c supernovae

    E-Print Network [OSTI]

    A. Elmhamdi; I. J. Danziger; D. Branch; B. Leibundgut; E. Baron; R. P. Kirshner

    2006-04-04T23:59:59.000Z

    The spectroscopic properties of a selected optical photospheric spectra of core collapse supernovae (CCSNe) are investigated.Special attention is devoted to traces of hydrogen at early phases. The generated spectra are found to match the observed ones reasonably well, including a list of only 23 candidate ions. Guided by SN Ib 1990I, the observed trough near 6300\\AA is attributed to H$\\alpha$ in almost all Type Ib events, although in some objects it becomes too weak to be discernible, especially at later phases. Alternative line identifications are discussed. Differences in the way hydrogen manifests its presence within CCSNe are highlighted. In Type Ib SNe, the H$\\alpha$ contrast velocity (i.e. line velocity minus the photospheric velocity) seems to increase with time at early epochs, reaching values as high as 8000 km s$^{-1}$ around 15-20 days after maximum and then remains almost constant. The derived photospheric velocities, indicate a lower velocity for Type II SNe 1987A and 1999em as compared to SN Ic 1994I and SN IIb 1993J, while Type Ib events display a somewhat larger variation. The scatter, around day 20, is measured to be $\\sim$5000 km s$^{-1}$. Following two simple approaches, rough estimates of ejecta and hydrogen masses are given. A mass of hydrogen of approximately 0.02 $M_\\odot$ is obtained for SN 1990I, while SNe 1983N and 2000H ejected $\\sim$0.008 $M_\\odot$ and $\\sim$0.08 $M_\\odot$ of hydrogen, respectively. SN 1993J has a higher hydrogen mass, $\\sim 0.7$ $M_\\odot$ with a large uncertainty. A low mass and thin hydrogen layer with very high ejection velocities above the helium shell, is thus the most likely scenario for Type Ib SNe. Some interesting and curious issues relating to oxygen lines suggest future investigations.

  4. Gettering of hydrogen and methane from a helium gas mixture

    SciTech Connect (OSTI)

    Cárdenas, Rosa Elia, E-mail: recarde1@uiwtx.edu [Department of Physics, The University of the Incarnate Word, 4301 Broadway, San Antonio, Texas 78209 (United States); Stewart, Kenneth D.; Cowgill, Donald F., E-mail: dfcowgi@sandia.gov [Sandia National Laboratories, Hydrogen and Metallurgical Sciences, 7011 East Avenue, Livermore, California 94550 (United States)

    2014-11-01T23:59:59.000Z

    In this study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H{sub 2} and CH{sub 4} can be removed simultaneously from the mixture using two SAES St 172{sup ®} getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. The optimum combination involved operating one getter at 650?°C to decompose the methane, and the second at 110?°C to remove the hydrogen. This approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  5. HYDROGEN SULFIDE KINETICS ON PEM FUEL CELL ELECTRODES V. A. Sethuramana

    E-Print Network [OSTI]

    Sethuraman, Vijay A.

    for the poisoning kinetics of hydrogen sulfide (H2S) on composite solid polymer electrolyte Pt (SPE-Pt) electrode and theoretically by a model, which predicts the oxidation current as a function of the applied potential. H2S) fuel cells, there is much less in the literature on H2S poisoning. Uribe et al showed

  6. Dynamic viscosity estimation of hydrogen sulfide using a predictive scheme based on molecular dynamics.

    E-Print Network [OSTI]

    Boyer, Edmond

    natural gases containing hydrogen sulfide H2S and/or carbon dioxide CO2) are often encountered properties are very scarce because of the very high toxicity of H2S which leads to very complicated safety procedures for the experimentalists. This is especially true for the high pressures and temperatures

  7. cpp header will be provided by the publisher Properties of Dense Fluid Hydrogen and Helium in Giant Gas

    E-Print Network [OSTI]

    Militzer, Burkhard

    cpp header will be provided by the publisher Properties of Dense Fluid Hydrogen and Helium in Giant molecular dynamics, equation of state, giant gas planets, hydrogen-helium mix- tures PACS 61.20.Ja, 61.25.Em, 61.25.Mv, 61.20.-p Equilibrium properties of hydrogen-helium mixtures under thermodynamic conditions

  8. Method of removing hydrogen sulfide from gases utilizing a zinc oxide sorbent and regenerating the sorbent

    DOE Patents [OSTI]

    Jalan, Vinod M. (Concord, MA); Frost, David G. (Maynard, MA)

    1984-01-01T23:59:59.000Z

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500.degree. C. to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent.

  9. Involvement of ERK in NMDA receptor-independent cortical neurotoxicity of hydrogen sulfide

    SciTech Connect (OSTI)

    Kurokawa, Yuko; Sekiguchi, Fumiko; Kubo, Satoko; Yamasaki, Yoshiko; Matsuda, Sachi; Okamoto, Yukari; Sekimoto, Teruki; Fukatsu, Anna; Nishikawa, Hiroyuki [Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan)] [Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan); Kume, Toshiaki [Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501 (Japan)] [Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Sciences, Kinki University School of Science and Engineering, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan)] [Division of Molecular Neurobiology, Department of Life Sciences, Kinki University School of Science and Engineering, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan); Akaike, Akinori [Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501 (Japan)] [Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501 (Japan); Kawabata, Atsufumi, E-mail: kawabata@phar.kindai.ac.jp [Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan)] [Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502 (Japan)

    2011-11-04T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Hydrogen sulfide causes NMDA receptor-independent neurotoxicity in mouse fetal cortical neurons. Black-Right-Pointing-Pointer Activation of ERK mediates the toxicity of hydrogen sulfide. Black-Right-Pointing-Pointer Apoptotic mechanisms are involved in the hydrogen-induced cell death. -- Abstract: Hydrogen sulfide (H{sub 2}S), a gasotransmitter, exerts both neurotoxicity and neuroprotection, and targets multiple molecules including NMDA receptors, T-type calcium channels and NO synthase (NOS) that might affect neuronal viability. Here, we determined and characterized effects of NaHS, an H{sub 2}S donor, on cell viability in the primary cultures of mouse fetal cortical neurons. NaHS caused neuronal death, as assessed by LDH release and trypan blue staining, but did not significantly reduce the glutamate toxicity. The neurotoxicity of NaHS was resistant to inhibitors of NMDA receptors, T-type calcium channels and NOS, and was blocked by inhibitors of MEK, but not JNK, p38 MAP kinase, PKC and Src. NaHS caused prompt phosphorylation of ERK and upregulation of Bad, followed by translocation of Bax to mitochondria and release of mitochondrial cytochrome c, leading to the nuclear condensation/fragmentation. These effects of NaHS were suppressed by the MEK inhibitor. Our data suggest that the NMDA receptor-independent neurotoxicity of H{sub 2}S involves activation of the MEK/ERK pathway and some apoptotic mechanisms.

  10. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOE Patents [OSTI]

    Siriwardane, Ranjani V. (Morgantown, WV)

    1997-01-01T23:59:59.000Z

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  11. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOE Patents [OSTI]

    Siriwardane, R.V.

    1997-12-30T23:59:59.000Z

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  12. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOE Patents [OSTI]

    Siriwardane, R.V.

    1999-02-02T23:59:59.000Z

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  13. Durable regenerable sorbent pellets for removal of hydrogen sulfide coal gas

    DOE Patents [OSTI]

    Siriwardane, Ranjani V. (Morgantown, WV)

    1999-01-01T23:59:59.000Z

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  14. State-of-the-art hydrogen sulfide control for geothermal energy systems: 1979

    SciTech Connect (OSTI)

    Stephens, F.B.; Hill, J.H.; Phelps, P.L. Jr.

    1980-03-01T23:59:59.000Z

    Existing state-of-the-art technologies for removal of hydrogen sulfide are discussed along with a comparative assessment of their efficiencies, reliabilities and costs. Other related topics include the characteristics of vapor-dominated and liquid-dominated resources, energy conversion systems, and the sources of hydrogen sulfide emissions. It is indicated that upstream control technologies are preferred over downsteam technologies primarily because upstream removal of hydrogen sulfide inherently controls all downstream emissions including steam-stacking. Two upstream processes for vapor-dominated resources appear promising; the copper sulfate (EIC) process, and the steam converter (Coury) process combined with an off-gas abatement system such as a Stretford unit. For liquid-dominated systems that produce steam, the process where the non-condensible gases are scrubbed with spent geothermal fluid appears to be promising. An efficient downstream technology is the Stretford process for non-condensible gas removal. In this case, partitioning in the surface condenser will determine the overall abatement efficiency. Recommendations for future environmental control technology programs are included.

  15. Use of ethylenediamine to remove hydrogen sulfide from coke oven gas

    SciTech Connect (OSTI)

    Marakhovskii, L.F.; Popov, A.A.; Rezunenko, Yu.I.

    1983-01-01T23:59:59.000Z

    The investigations of the equilibrium absorption of H/sub 2/S by an EDA solution which show that the solubility of hydrogen sulfide in ethylenediamine solutions is almost twice that in monoethanolamine solutions. Ethylenediamine may be used as an absorber for thorough removal of H/sub 2/S from coke oven gas in the presence of CO/sub 2/ and HCN. The hydrogen cyanide of coke oven gas, having practically no effect on the equilibrium absorption of H/sub 2/S and CO/sub 2/, may in this case be recovered in the form of ethylenethiourea - a marketable byproduct.

  16. The use of ethylenediamine to remove hydrogen sulfide from coke oven gas

    SciTech Connect (OSTI)

    Marakhovskii, L.F.; Rezunenko, Y.I.; Popov, A.A.

    1983-01-01T23:59:59.000Z

    The investigations of the equilibrium absorption of H/sub 2/S by an EDA solution showed the solubility of hydrogen sulfide in ethylenediamine solutions is almost twice that in monoethanolamine solutions. Ethylenediamine may be used as an absorber for thorough removal of H/sub 2/S from coke oven gas in the presence of CO/sub 2/ and HCN. The hydrogen cyanide of coke oven gas, having practically no effect on the equilibrium absorption of H/sub 2/S and CO/sub 2/, may in this case be used in the form of ethylenethiourea - a marketable byproduct.

  17. Electrochemical separation and concentration of hydrogen sulfide from gas mixtures

    DOE Patents [OSTI]

    Winnick, Jack (Atlanta, GA); Sather, Norman F. (Naperville, IL); Huang, Hann S. (Darian, IL)

    1984-10-30T23:59:59.000Z

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  18. Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under Physiologically Relevant

    E-Print Network [OSTI]

    Gates, Kent. S.

    Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under found that micromolar concentrations of H2S generated single-strand DNA cleavage. Mechanistic studies indicate that this process involved autoxidation of H2S to generate superoxide, hydrogen peroxide, and

  19. Quantitative evaluation of hydrogen sulfide at 0.3 M and 1.0 M-hydrogen-ion concentration

    E-Print Network [OSTI]

    Machel, Albert R.

    1958-01-01T23:59:59.000Z

    Concentration................. 14 1. Precipitation of Arsenic (III) sulfide....................... 15 2. Precipitation of Nickel (II) sulfide....................... 16 3* Precipitation of Manganese (II) sulfide....................... 17 4. Arsenic... (III) - Manganese (II) Separation................... 18 5- Arsenic (III) - Nickel (II) Separation................... 19 6. Precipitation of Bismuth. (Ill) sulfide....................... 20 7. Precipitation of Cobalt (II) sulfide...

  20. Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes

    E-Print Network [OSTI]

    Stone, Porter Walwyn

    1960-01-01T23:59:59.000Z

    concentrations of hydrogen sulfide, using water as a basis of comparison. For identical tube sizes and the same fluid velocity, both pure and dilute sulfur were found to have a film conductance ~- I less than ten percent that of water over most... the v x d curves for each concentration of diluent. Sulfur is diluted with H2S, added as persulfide Sulfur is diluted with H S, added as liquid 34 35 10. A Ratio of film conductance of pure sulfur to that of water versus temperature. The flow...

  1. Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

    DOE Patents [OSTI]

    Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

    2014-10-14T23:59:59.000Z

    A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

  2. Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments

    SciTech Connect (OSTI)

    Hara, T.; Asahi, H.

    2000-05-01T23:59:59.000Z

    Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

  3. Scanning-helium-ion-beam lithography with hydrogen silsesquioxane resist

    E-Print Network [OSTI]

    Winston, Donald

    A scanning-helium-ion-beam microscope is now commercially available. This microscope can be used to perform lithography similar to, but of potentially higher resolution than, scanning electron-beam lithography. This article ...

  4. SPHERICALLY SYMMETRIC NLTE MODEL ATMOSPHERES OF HOT HYDROGEN-HELIUM FIRST STARS

    SciTech Connect (OSTI)

    Kubat, Jiri [Astronomicky ustav, Akademie ved Ceske Republiky, CZ-251 65 Ondrejov (Czech Republic)

    2012-12-15T23:59:59.000Z

    We present results of our calculations of NLTE model stellar atmospheres for hot Population III stars composed of hydrogen and helium. We use our own computer code for the calculation of spherically symmetric NLTE model atmospheres in hydrostatic and radiative equilibrium. The model atmospheres are then used for the calculation of emergent fluxes. These fluxes serve to evaluate the flow of high-energy photons for energies higher than ionization energies of hydrogen and helium, the so-called ionizing photon fluxes. We also present the time evolution of the ionizing photon fluxes.

  5. On the computation of the eigenproblems of hydrogen and helium in strong magnetic and electric

    E-Print Network [OSTI]

    Sminchisescu, Cristian

    On the computation of the eigenproblems of hydrogen and helium in strong magnetic and electric fields with the sparse grid combination technique Jochen Garcke and Michael Griebel Institut f on sparse grids. Here, O(d·(log N)d-1 ) different problems, each of size O(N), have to be solved

  6. On the computation of the eigenproblems of hydrogen and helium in strong magnetic and electric

    E-Print Network [OSTI]

    Sminchisescu, Cristian

    On the computation of the eigenproblems of hydrogen and helium in strong magnetic and electric fields with the sparse grid combination technique Jochen Garcke and Michael Griebel Institut f@iam.uni­bonn.de We introduce the combination technique for the numerical solution of eigenproblems on sparse grids

  7. Method of recovering sulfur from the hydrogen sulfide contained in coke oven gases

    SciTech Connect (OSTI)

    Laufhutte, D.

    1985-04-30T23:59:59.000Z

    Ammonia and hydrogen sulfide are washed out of the coke oven gas and stripped from the wash liquor in the form of gases and fumes or vapors. The ammonia is decomposed in a nickel catalyzer and a small part of the decomposition gases is supplied directly to a combustion furnace, while the larger part of the combustion gases is first cooled and freed from condensate, and only then supplied to the combustion furnace. In the combustion furnace, the proportion of H/sub 2/S/SO/sub 2/ needed for the Claus process is adjusted by a partial combustion of the decomposition gases. The gases from the combustion furnace are then processed in the Claus plant to sulfur.

  8. Collisional excitation of hydrogen and the determination of the primordial helium abundance from H II regions

    E-Print Network [OSTI]

    G. Stasinska; Y. I. Izotov

    2001-09-17T23:59:59.000Z

    This paper investigates the effect of collisional enhancement of the hydrogen lines on the derivation of the helium abundances in low metallicity H II regions. For this, we have constructed a grid of photoionization models relevant for the analysis of giant \\hii regions in blue compact galaxies. We show that the effect of collisional excitation on the Halpha/Hbeta ratio can be quite important (up to 8% or more). The impact of this effect on the determination of the helium mass fraction has been tracked on four low-metallicity blue compact galaxies for which Keck spectra are available and which are among the best objects for the quest of the pregalactic helium abundance. We find that taking into account the effects of collisional excitation of hydrogen results in an upward correction of the helium mass fraction Y by up to 5%. However, combining with other systematic effects usually not considered in the determination of the helium abundance in low-metallicity galaxies, the resulting uncertainty should be much less.

  9. Mitigation of Hydrogen Sulfide Emissions in the Geysers KGRA (Staff Draft)

    SciTech Connect (OSTI)

    Buell, Richard

    1981-07-01T23:59:59.000Z

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H2S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H2S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H2S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staffs efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H2S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to promising, cost-effective control option. The CEC staff is currently developing a validated air dispersion model for The Geysers KGRA. The CEC staff recommends investigation of retrofit control options for existing units, investigation of alternative control technologies, and dispersion analysis for optimum plant location in order to maximize the development potential of The Geysers KGRA. Energy cost studies suggest that the EIC process would be the most cost-effective for retrofits at The Geysers. (DJE-2005)

  10. The Ratio of Helium- to Hydrogen-Atmosphere White Dwarfs: Direct Evidence for Convective Mixing

    E-Print Network [OSTI]

    P. -E. Tremblay; P. Bergeron

    2007-10-04T23:59:59.000Z

    We determine the ratio of helium- to hydrogen-atmosphere white dwarf stars as a function of effective temperature from a model atmosphere analysis of the infrared photometric data from the Two Micron All Sky Survey combined with available visual magnitudes. Our study surpasses any previous analysis of this kind both in terms of the accuracy of the Teff determinations as well as the size of the sample. We observe that the ratio of helium- to hydrogen-atmosphere white dwarfs increases gradually from a constant value of ~0.25 between Teff = 15,000 K and 10,000 K to a value twice as large in the range 10,000 > Teff > 8000 K, suggesting that convective mixing, which occurs when the bottom of the hydrogen convection zone reaches the underlying convective helium envelope, is responsible for this gradual transition. The comparison of our results with an approximate model used to describe the outcome of this convective mixing process implies hydrogen mass layers in the range log M_H/M_tot = -10 to -8 for about 15% of the DA stars that survived the DA to DB transition near Teff ~ 30,000 K, the remainder having presumably more massive layers above log M_H/M_tot ~ -6.

  11. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect (OSTI)

    K. C. Kwon

    2007-09-30T23:59:59.000Z

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 130-156 seconds at 120-140 C to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases, evaluate removal capabilities of hydrogen sulfide and COS from coal gases with formulated catalysts, and develop an economic regeneration method of deactivated catalysts. Simulated coal gas mixtures consist of 3,300-3,800-ppmv hydrogen sulfide, 1,600-1,900 ppmv sulfur dioxide, 18-21 v% hydrogen, 29-34 v% CO, 8-10 v% CO{sub 2}, 5-18 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 114-132 SCCM. The temperature of the reactor is controlled in an oven at 120-140 C. The pressure of the reactor is maintained at 116-129 psia. The molar ratio of H{sub 2}S to SO{sub 2} in the monolithic catalyst reactor is

  12. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect (OSTI)

    K.C. Kwon

    2009-09-30T23:59:59.000Z

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash coat, and catalytic metals, to develop a regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor. The task of developing kinetic rate equations and modeling the direct oxidation process to assist in the design of large-scale plants will be abandoned since formulation of catalysts suitable for the removal of H{sub 2}S and COS is being in progress. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 46-570 seconds under reaction conditions to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases and evaluate their capabilities in reducing hydrogen sulfide and COS in coal gases. Simulated coal gas mixtures consist of 3,200-4,000-ppmv hydrogen sulfide, 1,600-20,000-ppmv sulfur dioxide, 18-27 v% hydrogen, 29-41 v% CO, 8-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of simulated coal gas mixtures to the reactor are 30 - 180 cm{sup 3}/min at 1 atm and 25 C (SCCM). The temperature of the reactor is controlled in an oven at 120-155 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio

  13. Influence of technological factors on statics of hydrogen sulfide absorption from coke-oven gas by the ammonia process

    SciTech Connect (OSTI)

    Nazarov, V.G.; Kamennykh, B.M.; Rus'yanov, N.D.

    1983-01-01T23:59:59.000Z

    The basic technological factors that determine the effectiveness of hydrogen sulfide absorption from coke-oven gas by the cyclic ammonia process are the initial H/sub 2/S content of the gas, the degree of purification, the absorption temperature and the NH/sub 3/ and CO/sub 2/ contents of the absorbent solution. The effects of these factors on the statics of hydrogen sulfide absorption are studied. The investigation is based on the phase-equilibrium distributions of components in the absorption-desorption gas-cleaning cycle. The mathematical model is presented which includes the solution of a system of chemical equilibrium equations for reactions in the solution, material balances, and electrical neutrality. 4 references, 5 figures, 1 table.

  14. Accelerated Helium and Hydrogen Production in Fe-54 Doped Alloys - Measurements and Calculations for the FIST Experiment

    SciTech Connect (OSTI)

    Greenwood, Lawrence R.; Oliver, Brian M.; Ohnuki, Somei; Shiba, K.; Kohno, Yutaka; Kohyama, Akira; Robertson, J. P.; Meadows, J. W.; Gelles, David S.

    2000-12-01T23:59:59.000Z

    F-82H alloys isotopically enriched in 54Fe up to 86% were irradiated in the High Flux Isotope Reactor (HFIR) to determine the accelerated production of helium and hydrogen due to isotopic effects. Results are compared to calculations using isotopic helium production cross sections from ENDF/B-VI or GNASH and measured neutron spectra. Helium measurements demonstrated an accelerated helium (appm)/dpa ratio of 2.3 after a 1.25-year irradiation, an increase of a factor of 4.3 over natural iron. The accelerated helium production is due to higher helium production cross sections for 54Fe and 55Fe. Alloys doped with 55Fe could achieve helium/dpa ratios up to about 20, well above the fusion reactor ratio of 10. Hydrogen measurements were performed using a newly developed quadrupole mass spectrometer system at PNNL capable of detecting 5-appm hydrogen in milligram-sized irradiated specimens. Calculations predict that hydrogen production will be accelerated by about a factor of 13 over natural iron. However, measurements show that most of this hydrogen is not retained in the samples.

  15. Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect (OSTI)

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Guibing Zhao; Sanil John

    2006-09-30T23:59:59.000Z

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Several pulsed corona discharge (PCD) reactors have been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. Visual observation shows that the corona is not uniform throughout the reactor. The corona is stronger near the top of the reactor in argon, while nitrogen and mixtures of argon or nitrogen with H{sub 2}S produce stronger coronas near the bottom of the reactor. Both of these effects appear to be explainable base on the different electron collision interactions with monatomic versus polyatomic gases. A series of experiments varying reactor operating parameters, including discharge capacitance, pulse frequency, and discharge voltage were performed while maintaining constant power input to the reactor. At constant reactor power input, low capacitance, high pulse frequency, and high voltage operation appear to provide the highest conversion and the highest energy efficiency for H{sub 2}S decomposition. Reaction rates and energy efficiency per H{sub 2}S molecule increase with increasing flow rate, although overall H{sub 2}S conversion decreases at constant power input. Voltage and current waveform analysis is ongoing to determine the fundamental operating characteristics of the reactors. A metal infiltrated porous ceramic membrane was prepared using vanadium as the metal and an alumina tube. Experiments with this type of membrane are continuing, but the results thus far have been consistent with those obtained in previous project years: plasma driven permeation or superpermeability has not been observed. A new test cell specially designed to test the membranes has been constructed to provide basic science data on superpermeability.

  16. Doubly excited states of the hydrogen negative ion and helium atom in astrophysical plasmas

    SciTech Connect (OSTI)

    Jiang Pinghui [Center for Theoretical Atomic and Molecular Physics, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China); College of Electrical and Information Engineering, Heilongjiang Institute of Technology, Harbin 150050 (China); Kar, Sabyasachi; Zhou, Y. [Center for Theoretical Atomic and Molecular Physics, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China)

    2013-01-15T23:59:59.000Z

    The nonthermal effects on the doubly excited resonance states of the hydrogen negative ion and helium atom are investigated in Lorentzian astrophysical plasma environments using highly correlated Hylleraas-type wave functions in the framework of the stabilization method. Resonance parameters (resonance position and width) are reported for the first time as functions of the spectral index and plasma parameter. The screening effects are more pronounced in the stronger screening region.

  17. SUPERBURST MODELS FOR NEUTRON STARS WITH HYDROGEN- AND HELIUM-RICH ATMOSPHERES

    SciTech Connect (OSTI)

    Keek, L. [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Heger, A. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); In 't Zand, J. J. M., E-mail: keek@nscl.msu.edu [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

    2012-06-20T23:59:59.000Z

    Superbursts are rare day-long type I X-ray bursts due to carbon flashes on accreting neutron stars in low-mass X-ray binaries. They heat the neutron star envelope such that the burning of accreted hydrogen and helium becomes stable, and the common shorter X-ray bursts are quenched. Short bursts reappear only after the envelope cools down. We study multi-zone one-dimensional models of the neutron star envelope, in which we follow carbon burning during the superburst, and we include hydrogen and helium burning in the atmosphere above. We investigate the cases of both a solar-composition and a helium-rich atmosphere. This allows us to study for the first time a wide variety of thermonuclear burning behavior as well as the transitions between the different regimes in a self-consistent manner. For solar composition, burst quenching ends much sooner than previously expected. This is because of the complex interplay between the 3{alpha}, hot CNO, and CNO breakout reactions. Stable burning of hydrogen and helium transitions via marginally stable burning (mHz quasi-periodic oscillations) to less energetic bursts with short recurrence times. We find a short-lived bursting mode where weaker and stronger bursts alternate. Eventually the bursting behavior changes back to that of the pre-superburst bursts. Because of the scarcity of observations, this transition has not been directly detected after a superburst. Using the MINBAR burst catalog we identify the shortest upper limit on the quenching time for 4U 1636-536, and derive further constraints on the timescale on which bursts return.

  18. Low energy electron-enhanced etching of Si(100) in hydrogen/helium direct-current plasma

    E-Print Network [OSTI]

    Dove, Patricia M.

    Low energy electron-enhanced etching of Si(100) in hydrogen/helium direct-current plasma H. P of a dc plasma reactor, and thus receives a large flux of low-energy electrons and hydrogen molecules-0269 Received 7 September 1994; accepted for publication 6 March 1995 Low energy electron-enhanced etching of Si

  19. Production of hydrogen in non oxygen-evolving systems: co-produced hydrogen as a bonus in the photodegradation of organic pollutants and hydrogen sulfide

    SciTech Connect (OSTI)

    Sartoretti, C. Jorand; Ulmann, M.; Augustynski, J. (Electrochemistry Laboratory, Department of Chemistry, University of Geneva (CH)); Linkous, C.A. (Florida Solar Energy Center, University of Central Florida (US))

    2000-01-01T23:59:59.000Z

    This report was prepared as part of the documentation of Annex 10 (Photoproduction of Hydrogen) of the IEA Hydrogen Agreement. Subtask A of this Annex concerned photo-electrochemical hydrogen production, with an emphasis on direct water splitting. However, studies of non oxygen-evolving systems were also included in view of their interesting potential for combined hydrogen production and waste degradation. Annex 10 was operative from 1 March 1995 until 1 October 1998. One of the collaborative projects involved scientists from the Universities of Geneva and Bern, and the Federal Institute of Technology in Laussane, Switzerland. A device consisting of a photoelectrochemical cell (PEC) with a WO{sub 3} photoanode connected in series with a so-called Grazel cell (a dye sensitized liquid junction photovoltaic cell) was developed and studied in this project. Part of these studies concerned the combination of hydrogen production with degradation of organic pollutants, as described in Chapter 3 of this report. For completeness, a review of the state of the art of organic waste treatment is included in Chapter 2. Most of the work at the University of Geneva, under the supervision of Prof. J. Augustynski, was focused on the development and testing of efficient WO{sub 3} photoanodes for the photoelectrochemical degradation of organic waste solutions. Two types of WO{sub 3} anodes were developed: non transparent bulk photoanodes and non-particle-based transparent film photoanodes. Both types were tested for degradation and proved to be very efficient in dilute solutions. For instance, a solar-to-chemical energy conversion efficiency of 9% was obtained by operating the device in a 0.01M solution of methanol (as compared to about 4% obtained for direct water splitting with the same device). These organic compounds are oxidized to CO{sub 2} by the photocurrent produced by the photoanode. The advantages of this procedure over conventional electrolytic degradation are that much (an order of magnitude) less energy is required and that sunlight can be used directly. In the case of photoproduction of hydrogen, as compared to water splitting, feeding the anodic compartment of the PEC with an organic pollutant, instead of the usual supporting electrolyte, will bring about a substantial increase of the photocurrent at a given illumination. Thus, the replacement of the photo-oxidation of water by the photodegradation of organic waste will be accompanied by a gain in solar-to-chemical conversion efficiency and hence by a decrease in the cost of the photoproduced hydrogen. Taking into account the benefits and possible revenues obtainable by the waste degradation, this would seem to be a promising approach to the photoproduction of hydrogen. Hydrogen sulfide (H{sub 2}S) is another waste effluent requiring extensive treatment, especially in petroleum refineries. The so-called Claus process is normally used to convert the H{sub 2}S to elemental sulfur. A sulfur recovery process developed at the Florida Solar Energy Center is described briefly in Chapter 4 by Dr. C. Linkous as a typical example of the photoproduction of hydrogen in a non oxygen-evolving system. The encouraging results obtained in these investigations of photoelectrochemical hydrogen production combined with organic waste degradation, have prompted a decision to continue the work under the new IEA Hydrogen Agreement Annex 14, Photoelectrolytic Hydrogen Production.

  20. Selective Catalytic Oxidation of Hydrogen Sulfide to Elemental Sulfur from Coal-Derived Fuel Gases

    SciTech Connect (OSTI)

    Gardner, Todd H.; Berry, David A.; Lyons, K. David; Beer, Stephen K.; Monahan, Michael J.

    2001-11-06T23:59:59.000Z

    The development of low cost, highly efficient, desulfurization technology with integrated sulfur recovery remains a principle barrier issue for Vision 21 integrated gasification combined cycle (IGCC) power generation plants. In this plan, the U. S. Department of Energy will construct ultra-clean, modular, co-production IGCC power plants each with chemical products tailored to meet the demands of specific regional markets. The catalysts employed in these co-production modules, for example water-gas-shift and Fischer-Tropsch catalysts, are readily poisoned by hydrogen sulfide (H{sub 2}S), a sulfur contaminant, present in the coal-derived fuel gases. To prevent poisoning of these catalysts, the removal of H{sub 2}S down to the parts-per-billion level is necessary. Historically, research into the purification of coal-derived fuel gases has focused on dry technologies that offer the prospect of higher combined cycle efficiencies as well as improved thermal integration with co-production modules. Primarily, these concepts rely on a highly selective process separation step to remove low concentrations of H{sub 2}S present in the fuel gases and produce a concentrated stream of sulfur bearing effluent. This effluent must then undergo further processing to be converted to its final form, usually elemental sulfur. Ultimately, desulfurization of coal-derived fuel gases may cost as much as 15% of the total fixed capital investment (Chen et al., 1992). It is, therefore, desirable to develop new technology that can accomplish H{sub 2}S separation and direct conversion to elemental sulfur more efficiently and with a lower initial fixed capital investment.

  1. Practical-scale tests of cryogenic molecular sieve for separating low-concentration hydrogen isotopes from helium

    SciTech Connect (OSTI)

    Willms, R.S.; Taylor, D.J. [Los Alamos National Lab., NM (United States); Enoeda, M. [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)] [and others

    1994-12-31T23:59:59.000Z

    There are a number of cases in fusion fuel processing where low-concentration hydrogen isotopes need to be separated from helium. Usually the helium is a purge gas used to move hydrogen isotopes from one location to another. One of the most notable applications is associated with removing tritium from a solid ceramic breeder. For some designs which have been considered, helium with about 1 % protium is purged through the ceramic. The protium exchanges with tritium which has been bred in the solid. The resulting gas composed of helium ({approximately}99%), protium ({approximately}1%) and tritium ({approximately}0.01%) flows out of the blanket and, for further processing, requires separation of the hydrogen isotopes and the helium. Earlier bench-scale (about 50 cc of sieve) work at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory examined a number of adsorbents for their suitability for separating low-concentration hydrogen (no tritium) from helium. One of the effective adsorbents was Linde 5A molecular sieve. The purpose of this paper is to report practical-scale experiments including tritium. These tests used existing cryogenic molecular sieve beds (MSB`S) which each contain about 1.6 kg of Linde 5A molecular sieve.

  2. Oxidative stress suppresses the cellular bioenergetic effect of the 3-mercaptopyruvate sulfurtransferase/hydrogen sulfide pathway

    SciTech Connect (OSTI)

    Módis, Katalin [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Asimakopoulou, Antonia [Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece)] [Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece); Coletta, Ciro [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Papapetropoulos, Andreas [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States) [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece); Szabo, Csaba, E-mail: szabocsaba@aol.com [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)

    2013-04-19T23:59:59.000Z

    Highlights: •Oxidative stress impairs 3-MST-derived H{sub 2}S production in isolated enzyme and in isolated mitochondria. •This impairs the stimulatory bioenergetic effects of H{sub 2}S in hepatocytes. •This has implications for the pathophysiology of diseases with oxidative stress. -- Abstract: Recent data show that lower concentrations of hydrogen sulfide (H{sub 2}S), as well as endogenous, intramitochondrial production of H{sub 2}S by the 3-mercaptopyruvate (3-MP)/3-mercaptopyruvate sulfurtransferase (3-MST) pathway serves as an electron donor and inorganic source of energy to support mitochondrial electron transport and ATP generation in mammalian cells by donating electrons to Complex II. The aim of our study was to investigate the role of oxidative stress on the activity of the 3-MP/3-MST/H{sub 2}S pathway in vitro. Hydrogen peroxide (H{sub 2}O{sub 2}, 100–500 ?M) caused a concentration-dependent decrease in the activity of recombinant mouse 3-MST enzyme. In mitochondria isolated from murine hepatoma cells, H{sub 2}O{sub 2} (50–500 ?M) caused a concentration-dependent decrease in production of H{sub 2}S from 3-MP. In cultured murine hepatoma cells H{sub 2}O{sub 2}, (3–100 ?M), did not result in overall cytotoxicity, but caused a partial decrease in basal oxygen consumption and respiratory reserve rapacity. The positive bioenergetic effect of 3-MP (100–300 nM) was completely abolished by pre-treatment of the cells with H{sub 2}O{sub 2} (50 ?M). The current findings demonstrate that oxidative stress inhibits 3-MST activity and interferes with the positive bioenergetic role of the 3-MP/3-MST/H{sub 2}S pathway. These findings may have implications for the pathophysiology of various conditions associated with increased oxidative stress, such as various forms of critical illness, cardiovascular diseases, diabetes or physiological aging.

  3. Ab initio Equation of State data for hydrogen, helium, and water and the internal structure of Jupiter

    E-Print Network [OSTI]

    N. Nettelmann; B. Holst; A. Kietzmann; M. French; R. Redmer; D. Blaschke

    2008-06-06T23:59:59.000Z

    The equation of state of hydrogen, helium, and water effects interior structure models of giant planets significantly. We present a new equation of state data table, LM-REOS, generated by large scale quantum molecular dynamics simulations for hydrogen, helium, and water in the warm dense matter regime, i.e.for megabar pressures and temperatures of several thousand Kelvin, and by advanced chemical methods in the complementary regions. The influence of LM-REOS on the structure of Jupiter is investigated and compared with state-of-the-art results within a standard three-layer model consistent with astrophysical observations of Jupiter. Our new Jupiter models predict an important impact of mixing effects of helium in hydrogen with respect to an altered compressibility and immiscibility.

  4. Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions

    E-Print Network [OSTI]

    Randall K. Smith; Nancy S. Brickhouse; Duane A. Liedahl; John C. Raymond

    2001-06-26T23:59:59.000Z

    New X-ray observatories (Chandra and XMM-Newton) are providing a wealth of high-resolution X-ray spectra in which hydrogen- and helium-like ions are usually strong features. We present results from a new collisional-radiative plasma code, the Astrophysical Plasma Emission Code (APEC), which uses atomic data in the companion Astrophysical Plasma Emission Database (APED) to calculate spectral models for hot plasmas. APED contains the requisite atomic data such as collisional and radiative rates, recombination cross sections, dielectronic recombination rates, and satellite line wavelengths. We compare the APEC results to other plasma codes for hydrogen- and helium-like diagnostics, and test the sensitivity of our results to the number of levels included in the models. We find that dielectronic recombination with hydrogen-like ions into high (n=6-10) principal quantum numbers affects some helium-like line ratios from low-lying (n=2) transitions.

  5. Extreme helium stars: non-LTE matters Helium and hydrogen spectra of the unique objects V652 Her and HD144941

    E-Print Network [OSTI]

    N. Przybilla; K. Butler; U. Heber; C. S. Jeffery

    2005-10-03T23:59:59.000Z

    Quantitative analyses of low-mass hydrogen-deficient (super-)giant stars - so-called extreme helium stars - to date face two major difficulties. First, theory fails to reproduce the observed helium lines in their entirety, wings and line cores. Second, a general mismatch exists for effective temperatures derived from ionization equilibria and from spectral energy distributions. Here, we demonstrate how the issue can be resolved using state-of-the-art non-LTE line-formation for these chemically peculiar objects. Two unique high-gravity B-type objects are discussed in detail, the pulsating variable V652 Her and the metal-poor star HD144941. In the first case atmospheric parameters from published LTE analyses are largely recovered, in the other a systematic offset is found. Hydrogen abundances are systematically smaller than previously reported, by up to a factor ~2. Extreme helium stars turn out to be important testbeds for non-LTE model atoms for helium. Improved non-LTE computations show that analyses assuming LTE or based on older non-LTE model atoms can predict equivalent widths, for the HeI 10830A transition in particular, in error by up to a factor ~3.

  6. Isotopes of helium, hydrogen, and carbon as groundwater tracers in aquifers along the Colorado River

    E-Print Network [OSTI]

    Haber, Samuel Ainsworth

    2009-01-01T23:59:59.000Z

    composition of radiogenic helium and its use to studyH. , Lupton, J.E. (1981) Helium-3 and mantle volatiles inand Izbicki, J.A. (2003). Helium isotope studies in the

  7. MASS/RADIUS CONSTRAINTS ON THE QUIESCENT NEUTRON STAR IN M13 USING HYDROGEN AND HELIUM ATMOSPHERES

    SciTech Connect (OSTI)

    Catuneanu, A.; Heinke, C. O.; Sivakoff, G. R. [Department of Physics, University of Alberta, Room 238 CEB, Edmonton, AB T6G 2G7 (Canada)] [Department of Physics, University of Alberta, Room 238 CEB, Edmonton, AB T6G 2G7 (Canada); Ho, W. C. G. [School of Mathematics, University of Southampton, Southampton SO17 1BJ (United Kingdom)] [School of Mathematics, University of Southampton, Southampton SO17 1BJ (United Kingdom); Servillat, M., E-mail: heinke@ualberta.ca [Laboratoire AIM, CEA Saclay, Bat. 709, F-91191 Gif-sur-Yvette (France)

    2013-02-20T23:59:59.000Z

    The mass and radius of the neutron star (NS) in low-mass X-ray binaries can be obtained by fitting the X-ray spectrum of the NS in quiescence, and the mass and radius constrains the properties of dense matter in NS cores. A critical ingredient for spectral fits is the composition of the NS atmosphere: hydrogen atmospheres are assumed in most prior work, but helium atmospheres are possible if the donor star is a helium white dwarf. Here we perform spectral fits to XMM-Newton, Chandra, and ROSAT data of a quiescent NS in the globular cluster M13. This NS has the smallest inferred radius from previous spectral fitting. Assuming an atmosphere composed of hydrogen, we find a significantly larger radius, more consistent with those from other quiescent NSs. With a helium atmosphere (an equally acceptable fit), we find even larger values for the radius.

  8. The relationship between hydrogen permeation and sulfide stress cracking susceptibility of OCTG materials at different temperatures and pH values

    SciTech Connect (OSTI)

    Vera, J.R.; Case, R. [INTEVEP S.A., Caracas (Venezuela); Castro, A. [LAGOVEN, S.A., La Salina (Venezuela)

    1997-08-01T23:59:59.000Z

    The sulfide stress cracking susceptibility of high strength steels used for oil grade tubulars (OCTG) was found to correlate with the hydrogen concentration inside the metal, in equilibrium with the H{sub 2}S saturated solution at different temperatures and pH values. This correlation can be applied to extrapolate laboratory tests results, obtained using standardized solutions, to actual field conditions.

  9. Cathodic hydrogen embrittlement of a 22% chromium 5% nickel duplex stainless steel in sulfide containing 3.5 wt% NaCl solution

    SciTech Connect (OSTI)

    Tsai, S.Y. [Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Materials Research Labs.; Shih, H.C. [National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Materials Science and Engineering; Yen, K.P. [National Chung Hsing Univ., Taichung (Taiwan, Province of China). Inst. of Materials Engineering

    1996-08-01T23:59:59.000Z

    Hydrogen embrittlement (HE) of a 2,205 duplex stainless steel has been studied by slow straining of tensile specimens in sulfide containing 3.5 wt% NaCl solution. A more complex sulfide-concentration-dependent loss in ductility was discovered at controlled potentials in {minus}1,100 mV (SCE). It is believed that HE was controlled by the critical concentration of S as a promoter at lower sulfide levels and recovery of ductility at higher sulfide concentrations was attributed to the role of the sulfide as a cathodic inhibitor. No stress corrosion cracking (SCC) was observed at anodic polarization in this system. The electrochemical results indicate that the corrosion potentials of 2,205 duplex stainless steel in 3.5 wt% NaCl solution move to the less noble direction with increasing the sulfide concentration or with decreasing the solution acidity. This trend was not influenced by the presence of dissolved oxygen. Under severe HE environments transgranular cleavage is the favored path for cracking.

  10. A dependence of carbon impurity transport coefficients on fuel ions in hydrogen and helium plasmas of Large Helical Device

    SciTech Connect (OSTI)

    Nozato, H.; Morita, S.; Goto, M.; Takase, Y.; Ejiri, A.; Amano, T.; Tanaka, K.; Inagaki, S. [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8563 (Japan); National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Goshikien 1-1706, Nisshin, Aichi 470-0105 (Japan); National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

    2006-09-15T23:59:59.000Z

    Impurity transport of carbon has been studied using a new method combined carbon pellet injection with high-spatial resolution bremsstrahlung measurement on the Large Helical Device [A. Iiyoshi et al., Fusion Technol. 17, 169 (1990)]. The carbon pellets are injected into a steady phase in neutral beam heated discharges with a standard configuration of R{sub ax}=3.6 m. The particle transport coefficients (diffusion coefficient D and convective velocity V) are inferred using a diffusive/convective model. The results are compared between hydrogen and helium plasmas. As a result, it is found that the analyzed D has a constant radial profile with almost closed values of 0.2 m{sup 2}/s in both plasmas. On the other hand, the inward V is required only at the plasma outer region ({rho}>0.6) where the electron density gradient exits, and the inward V in helium plasmas (-0.4 m/s at {rho}=0.8 and n{sub e}{approx}4.0x10{sup 19} m{sup -3}) is nearly half as much as that in hydrogen plasmas (-0.7 m/s). This difference of the inward V between hydrogen and helium plasmas suggests a dependence on the charge state of fuel ions predicted from neoclassical theory.

  11. Production of Hydrogen by Superadiabatic Decomposition of Hydrogen Sulfide - Final Technical Report for the Period June 1, 1999 - September 30, 2000

    SciTech Connect (OSTI)

    Rachid B. Slimane; Francis S. Lau; Javad Abbasian

    2000-10-01T23:59:59.000Z

    The objective of this program is to develop an economical process for hydrogen production, with no additional carbon dioxide emission, through the thermal decomposition of hydrogen sulfide (H{sub 2}S) in H{sub 2}S-rich waste streams to high-purity hydrogen and elemental sulfur. The novel feature of the process being developed is the superadiabatic combustion (SAC) of part of the H{sub 2}S in the waste stream to provide the thermal energy required for the decomposition reaction such that no additional energy is required. The program is divided into two phases. In Phase 1, detailed thermochemical and kinetic modeling of the SAC reactor with H{sub 2}S-rich fuel gas and air/enriched air feeds is undertaken to evaluate the effects of operating conditions on exit gas products and conversion efficiency, and to identify key process parameters. Preliminary modeling results are used as a basis to conduct a thorough evaluation of SAC process design options, including reactor configuration, operating conditions, and productivity-product separation schemes, with respect to potential product yields, thermal efficiency, capital and operating costs, and reliability, ultimately leading to the preparation of a design package and cost estimate for a bench-scale reactor testing system to be assembled and tested in Phase 2 of the program. A detailed parametric testing plan was also developed for process design optimization and model verification in Phase 2. During Phase 2 of this program, IGT, UIC, and industry advisors UOP and BP Amoco will validate the SAC concept through construction of the bench-scale unit and parametric testing. The computer model developed in Phase 1 will be updated with the experimental data and used in future scale-up efforts. The process design will be refined and the cost estimate updated. Market survey and assessment will continue so that a commercial demonstration project can be identified.

  12. Practical-scale tests of cryogenic molecular sieve for separating low-concentration hydrogen isotopes from helium

    SciTech Connect (OSTI)

    Willms, R.S.; Taylor, D.J. [Los Alamos National Lab., NM (United States); Enoeda, Mikio; Okuno, Kenji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1994-06-01T23:59:59.000Z

    Earlier bench-scale work at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory examined a number of adsorbents for their suitability for separating low-concentration hydrogen (no tritium) from helium. One of the effective adsorbents was Linde 5A molecular sieve. Recently, experiments including tritium were conducted using practical-scale adsorbers. These tests used existing cryogenic molecular sieve beds (CMSB`s) which each contain about 1.6 kg of Linde 5A molecular sieve. They are part of the TSTA integrated tritium processing system. Gas was fed to each CMSB at about 13 SLPM with a nominal composition of 99% He, 0.98% H{sub 2} and 0.02% HT. In all cases, for an extended period of time, the beds allowed no detectable (via Raman spectroscopy) hydrogen isotopes to escape in the bed effluent. Thereafter, the hydrogen isotopes appeared in the bed exit with a relatively sharp breakthrough curve. This work concludes that cryogenic molecular sieve adsorption is an practical and effective means of separating low-concentration hydrogen isotopes from a helium carrier.

  13. Development and introduction of methods for extracting hydrogen sulfide and hydrogen cyanide from coke-oven gas

    SciTech Connect (OSTI)

    Litvinenko, M.S.; Zaichenko, V.M.

    1980-01-01T23:59:59.000Z

    The progress between 1933 and the present in desulfurizing coal gas from coke ovens and making use of the by-products to produce sulfuric acid, thioyanates, etc. is described. The vacuum carbonate process and the monoethanolamine method are apparently now preferred, but some plants are still using modified arsenic-soda processes. More recently additional by-products have been thiocyanates (for producing acrylonitrile fiber) and hydrogen xanthanates. The production of other organic sulfur and cyanide compounds has been investigated for use as herbicides, corrosion inhibitors, etc. (LTN)

  14. MEASUREMENT OF THE ISOTOPIC COMPOSITION OF HYDROGEN AND HELIUM NUCLEI IN COSMIC RAYS WITH THE PAMELA EXPERIMENT

    SciTech Connect (OSTI)

    Adriani, O.; Bongi, M. [Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples ''Federico II'', I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991, Moscow (Russian Federation); Bellotti, R.; Bruno, A. [Department of Physics, University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Borisov, S.; Casolino, M.; De Pascale, M. P. [INFN, Sezione di Rome ''Tor Vergata'', I-00133 Rome (Italy); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); Danilchenko, I. A. [National Research Nuclear University MEPhI, RU-115409 Moscow (Russian Federation); De Santis, C. [Department of Physics, University of Rome ''Tor Vergata'', I-00133 Rome (Italy); and others

    2013-06-10T23:59:59.000Z

    The satellite-borne experiment PAMELA has been used to make new measurements of cosmic ray H and He isotopes. The isotopic composition was measured between 100 and 600 MeV/n for hydrogen and between 100 and 900 MeV/n for helium isotopes over the 23rd solar minimum from 2006 July to 2007 December. The energy spectrum of these components carries fundamental information regarding the propagation of cosmic rays in the galaxy which are competitive with those obtained from other secondary to primary measurements such as B/C.

  15. Tunneling effects in the kinetics of helium and hydrogen isotopes desorption from single-walled carbon nanotube bundles

    SciTech Connect (OSTI)

    Danilchenko, B. A., E-mail: danil@iop.kiev.ua; Yaskovets, I. I.; Uvarova, I. Y. [Institute of Physics NASU, Pr. Nauki 46, 03680 Kiev (Ukraine); Dolbin, A. V.; Esel'son, V. B.; Basnukaeva, R. M.; Vinnikov, N. A. [B. Verkin Institute for Low Temperature Physics and Engineering NASU, 47 Lenin Ave., Kharkov 61103 (Ukraine)

    2014-04-28T23:59:59.000Z

    The kinetics of desorption both helium isotopes and molecules of hydrogen and deuterium from open-ended or ?-irradiated single-walled carbon nanotube bundles was investigated in temperature range of 10–300?K. The gases desorption rates obey the Arrhenius law at high temperatures, deviate from it with temperature reduction and become constant at low temperatures. These results indicate the quantum nature of gas outflow from carbon nanotube bundles. We had deduced the crossover temperature below which the quantum corrections to the effective activation energy of desorption become significant. This temperature follows linear dependence against the inverse mass of gas molecule and is consistent with theoretical prediction.

  16. Hydrogenation of the nanopowders that form in a carbon-helium plasma stream during the introduction of Ni and Mg

    SciTech Connect (OSTI)

    Churilov, G. N., E-mail: churilov@iph.krasn.ru; Osipova, I. V. [Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation); Tomashevich, Ye. V. [Russian Academy of Sciences, Institute of Chemistry and Chemical Technology, Siberian Branch (Russian Federation); Glushchenko, G. A.; Fedorov, A. S.; Popov, Z. I. [Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation); Bulina, N. V. [Russian Academy of Sciences, Institute of Solid State Chemistry and Mechanochemistry (Russian Federation); Vereshchagin, S. N.; Zhizhaev, A. M. [Russian Academy of Sciences, Institute of Chemistry and Chemical Technology, Siberian Branch (Russian Federation); Cherepakhin, A. V. [Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation)

    2011-12-15T23:59:59.000Z

    Composite nanoparticles consisting of magnesium, nickel, and carbon atoms are studied both theoretically and experimentally. The calculations performed in terms of the density functional theory show that the jump frequency of hydrogen atoms in nickel-containing magnesium hydride increases substantially near impurity nickel atoms; as a result, the rate of hydrogen absorption by magnesium also increases. Nickel on the magnesium surface is shown to be absorbed via an island growth mechanism. Composite Mg-C, Ni-C, and Mg-Ni-C powders are produced by plasmachemical synthesis in a carbon-helium plasma stream. Hydrogen is introduced into a chamber during synthesis. It is found by X-ray photoelectron spectroscopy and thermogravimetric analysis that, among these three composites, only Mg-Ni-C contains magnesium fixed in the MgH{sub 2} compound. The process of such 'ultrarapid' hydrogenation of magnesium, which occurs in the time of formation of composite nanoparticles, can be explained by the catalytic action of nickel, which is enhanced by a high temperature. Scanning electron microscopy micrographs demonstrate the dynamics of the dehydrogenation of Mg-Ni-C composite nanoparticles in heating by an electron beam.

  17. Cryogenic system with GM cryocooler for krypton, xenon separation from hydrogen-helium purge gas

    SciTech Connect (OSTI)

    Chu, X. X.; Zhang, D. X.; Qian, Y.; Liu, W. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800 (China); Zhang, M. M.; Xu, D. [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190 (China)

    2014-01-29T23:59:59.000Z

    In the thorium molten salt reactor (TMSR), fission products such as krypton, xenon and tritium will be produced continuously in the process of nuclear fission reaction. A cryogenic system with a two stage GM cryocooler was designed to separate Kr, Xe, and H{sub 2} from helium purge gas. The temperatures of two stage heat exchanger condensation tanks were maintained at about 38 K and 4.5 K, respectively. The main fluid parameters of heat transfer were confirmed, and the structural heat exchanger equipment and cold box were designed. Designed concentrations after cryogenic separation of Kr, Xe and H{sub 2} in helium recycle gas are less than 1 ppb.

  18. Zinc sulfide liquefaction catalyst

    DOE Patents [OSTI]

    Garg, Diwakar (Macungie, PA)

    1984-01-01T23:59:59.000Z

    A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

  19. Hydrogen-assisted laser-induced resonant transitions between metastable states of antiprotonic helium atoms

    E-Print Network [OSTI]

    Ketzer, B; Von Egidy, T; Maierl, C; Pohl, R; Eades, John; Widmann, E; Yamazaki, T; Kumakura, M; Morita, N; Hayano, R S; Hori, Masaki; Ishikawa, T; Torii, H A; Sugai, I; Horváth, D

    1997-01-01T23:59:59.000Z

    Laser resonance transitions between normally metastable states of antiprotonic helium atoms were observed making use of state dependent quenching effects caused by small admixtures of \\htwo\\ molecules. By selectively shortening the lifetimes of states with higher principal quantum number $n$ as compared to those of lower $n$, this method for the first time provides access to all initially populated metastable states of \\pbar\\hep\\ atoms. This was demonstrated by observing the transitions $(n,l)=(38,l)\\rightarrow (39,l+1),\\ l=35,36,37$ and $(n,l)=(37,l)\\rightarrow (38,l+1),\\ l=34,35,36$.

  20. Hydrogen | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    with a catalyst of molybdenum sulfide and exposed to sunlight, these pillars generate hydrogen gas from the hydrogen ions liberated by splitting water. Each pillar is approximately...

  1. Hydrodynamic simulations of a combined hydrogen, helium thermonuclear runaway on a 10-km neutron star

    SciTech Connect (OSTI)

    Starrfield, S.; Kenyon, S.; Truran, J.W.; Sparks, W.M.

    1983-01-01T23:59:59.000Z

    We have used a Lagrangian, hydrodynamic stellar-evolution computer code to evolve a thermonuclear runaway in the accreted hydrogen rich envelope of a 1.0M, 10-km neutron star. Our simulation produced an outburst which lasted about 2000 sec and peak effective temperature was 3 keV. The peak luminosity exceeded 2 x 10/sup 5/ L. A shock wave caused a precursor in the light curve which lasted 10/sup -5/ sec.

  2. Process for producing cadmium sulfide on a cadmium telluride surface

    DOE Patents [OSTI]

    Levi, Dean H. (Lakewood, CO); Nelson, Art J. (Longmont, CO); Ahrenkiel, Richard K. (Lakewood, CO)

    1996-01-01T23:59:59.000Z

    A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.

  3. Heat capacity of quantum adsorbates: Hydrogen and helium on evaporated gold films

    SciTech Connect (OSTI)

    Birmingham, J.T. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

    1996-06-01T23:59:59.000Z

    The author has constructed an apparatus to make specific heat measurements of quantum gases adsorbed on metallic films at temperatures between 0.3 and 4 K. He has used this apparatus to study quench-condensed hydrogen films between 4 and 923 layers thick with J = 1 concentrations between 0.28 and 0.75 deposited on an evaporated gold surface. He has observed that the orientational ordering of the J = 1 molecules depends on the substrate temperature during deposition of the hydrogen film. He has inferred that the density of the films condensed at the lowest temperatures is 25% higher than in bulk H{sub 2} crystals and have observed that the structure of those films is affected by annealing at 3.4 K. The author has measured the J = 1 to J = 0 conversion rate to be comparable to that of the bulk for thick films; however, he found evidence that the gold surface catalyzes conversion in the first two to four layers. He has also used this apparatus to study films of {sup 4}He less than one layer thick adsorbed on an evaporated gold surface. He shows that the phase diagram of the system is similar to that for {sup 4}He/graphite although not as rich in structure, and the phase boundaries occur at different coverages and temperatures. At coverages below about half a layer and at sufficiently high temperatures, the {sup 4}He behaves like a two-dimensional noninteracting Bose gas. At lower temperatures and higher coverages, liquidlike and solidlike behavior is observed. The Appendix shows measurements of the far-infrared absorptivity of the high-{Tc} superconductor La{sub 1.87}Sr{sub 0.13}CuO{sub 4}.

  4. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    SciTech Connect (OSTI)

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24T23:59:59.000Z

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  5. The Cost of Helium Refrigerators and Coolers for Superconducting Devices as a Function of Cooling at 4 K

    E-Print Network [OSTI]

    Green, Michael A.

    2008-01-01T23:59:59.000Z

    pulse tube coolers as liquefiers of helium and hydrogen. 7.Byrns, R. A. , "Large Helium Refrigerators and Liquefiers,"P. , et al, “Economics of Large Helium Cryogenics Systems:

  6. Microstructural Evolution of Alloy 718 at High Helium and Hydrogen Generation Rates during Irradiation with 600-800 MeV protons

    SciTech Connect (OSTI)

    Sencer, Bulent H. (PNNL); Bond, G M. (PNNL); Garner, F.A. (Pacific Northwest National Laboratory); Hamilton, M L. (PNNL); Oliver, Brian M. (BATTELLE (PACIFIC NW LAB)); Thomas, L E. (PNNL); Maloy, S A. (Los Alamos National Laboratory); Sommer, Walter F. (LOS ALAMOS NATL LAB); James, M R. (Los Alamos National Laboratory); Ferguson, P D. (Los Alamos National Laboratory)

    2000-12-01T23:59:59.000Z

    When precipitation hardened Alloy 718 is irradiated with high-energy protons (600?800 MeV) and spallation neutrons at temperatures below > 60 C, it quickly hardens and loses almost all uniform elongation. It later softens somewhat at higher exposures but does not regain any elongation. This behavior is explained in terms of the evolution of Frank loop formation, disordering and eventual dissolution of the?? and?? strengthening phases, and the steady accumulation of very large levels of helium and hydrogen. These gases must be dispersed on a very fine scale in the matrix since no cavities could be found.

  7. The Knee of the Cosmic Hydrogen and Helium Spectrum below 1 PeV Measured by ARGO-YBJ and a Cherenkov Telescope of LHAASO

    E-Print Network [OSTI]

    B. Bartoli; P. Bernardini; X. J. Bi; P. Branchini; A. Budano; P. Camarri; Z. Cao; R. Cardarelli; S. Catalanotti; S. Z. Chen; T. L. Chen; P. Creti; S. W. Cui; B. Z. Dai; A. D'Amone; Danzengluobu; I. De Mitri; B. D'Ettorre Piazzoli; T. Di Girolamo; G. Di Sciascio; C. F. Feng; Zhaoyang Feng; Zhenyong Feng; Q. B. Gou; Y. Q. Guo; H. H. He; Haibing Hu; Hongbo Hu; M. Iacovacci; R. Iuppa; H. Y. Jia; Labaciren; H. J. Li; G. Liguori; C. Liu; J. Liu; M. Y. Liu; H. Lu; L. L. Ma; X. H. Ma; G. Mancarella; S. M. Mari; G. Marsella; D. Martello; S. Mastroianni; P. Montini; C. C. Ning; M. Panareo; L. Perrone; P. Pistilli; F. Ruggieri; P. Salvini; R. Santonico; P. R. Shen; X. D. Sheng; F. Shi; A. Surdo; Y. H. Tan; P. Vallania; S. Vernetto; C. Vigorito; H. Wang; C. Y. Wu; H. R. Wu; L. Xue; Q. Y. Yang; X. C. Yang; Z. G. Yao; A. F. Yuan; M. Zha; H. M. Zhang; L. Zhang; X. Y. Zhang; Y. Zhang; J. Zhao; Zhaxiciren; Zhaxisangzhu; X. X. Zhou; F. R. Zhu; Q. Q. Zhu; G. Zizzi; Y. X. Bai; M. J. Chen; Y. Chen; S. H. Feng; B. Gao; M. H. Gu; C. Hou; X. X. Li; J. Liu; J. L. Liu; X. Wang; G. Xiao; B. K. Zhang; S. S. Zhang; B. Zhou; X. Zuo

    2015-02-11T23:59:59.000Z

    The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach in finding their origin. Locating the "knees" of the spectra is an important part of the approach and has yet to be achieved. Here we report a measurement of the mixed Hydrogen and Helium spectrum using the combination of the ARGO-YBJ experiment and of a prototype Cherenkov telescope for the LHAASO experiment. A knee feature at 640+/-87 TeV, with a clear steepening of the spectrum, is observed. This gives fundamental inputs to galactic cosmic ray acceleration models.

  8. The Knee of the Cosmic Hydrogen and Helium Spectrum below 1 PeV Measured by ARGO-YBJ and a Cherenkov Telescope of LHAASO

    E-Print Network [OSTI]

    Bartoli, B; Bi, X J; Branchini, P; Budano, A; Camarri, P; Cao, Z; Cardarelli, R; Catalanotti, S; Chen, S Z; Chen, T L; Creti, P; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liguori, G; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Panareo, M; Perrone, L; Pistilli, P; Ruggieri, F; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G; Bai, Y X; Chen, M J; Chen, Y; Feng, S H; Gao, B; Gu, M H; Hou, C; Li, X X; Liu, J L; Wang, X; Xiao, G; Zhang, B K; Zhang, S S; Zhou, B; Zuo, X

    2015-01-01T23:59:59.000Z

    The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach in finding their origin. Locating the "knees" of the spectra is an important part of the approach and has yet to be achieved. Here we report a measurement of the mixed Hydrogen and Helium spectrum using the combination of the ARGO-YBJ experiment and of a prototype Cherenkov telescope for the LHAASO experiment. A knee feature at 640+/-87 TeV, with a clear steepening of the spectrum, is observed. This gives fundamental inputs to galactic cosmic ray acceleration models.

  9. Design modification for the modular helium reactor for higher temperature operation and reliability studies for nuclear hydrogen production processes

    E-Print Network [OSTI]

    Reza, S.M. Mohsin

    2009-05-15T23:59:59.000Z

    Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet...

  10. A New Wide Range Equation of State for Helium-4 

    E-Print Network [OSTI]

    Ortiz Vega, Diego O

    2013-08-01T23:59:59.000Z

    chemical inertness makes it a safer option. Helium replaced hydrogen for blimps in the 1930s after a number of tragic accidents involving hydrogen- filled airships. Helium is used in blimps for advertising, to detect low-flying cruise missiles...

  11. HELIUM, SOLID 1 Helium, Solid

    E-Print Network [OSTI]

    Glyde, Henry R.

    HELIUM, SOLID 1 Helium, Solid Henry R. Glyde Introduction Helium was first solidified at the famous focused on the melting curve, the specific heat, and the thermal conductivity of solid helium as a test criterion of melting does not hold in solid helium. This pioneering work up to 1957 is elegantly

  12. Ab Initio Equation of State for Hydrogen-Helium Mixtures with Recalibration of the Giant-Planet Mass-Radius Relation

    E-Print Network [OSTI]

    Militzer, B

    2013-01-01T23:59:59.000Z

    Using density functional molecular dynamics simulations, we determine the equation of state for hydrogen-helium mixtures spanning density-temperature conditions typical of giant planet interiors, ~0.2-9 g/cc and 1000-80000 K for a typical helium mass fraction of 0.245. In addition to computing internal energy and pressure, we determine the entropy using an ab initio thermodynamic integration technique. A comprehensive equation of state (EOS) table with 391 density-temperature points is constructed and the results are presented in form of two-dimensional free energy fit for interpolation. Deviations between our ab initio EOS and the semi-analytical EOS model by Saumon and Chabrier are analyzed in detail, and we use the results for initial revision of the inferred thermal state of giant planets with known values for mass and radius. Changes are most pronounced for planets in the Jupiter mass range and below. We present a revision to the mass-radius relationship which makes the hottest exoplanets increase in rad...

  13. AB INITIO EQUATION OF STATE FOR HYDROGEN-HELIUM MIXTURES WITH RECALIBRATION OF THE GIANT-PLANET MASS-RADIUS RELATION

    SciTech Connect (OSTI)

    Militzer, B. [Departments of Earth and Planetary Science and of Astronomy, University of California, Berkeley, CA 94720 (United States); Hubbard, W. B. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2013-09-10T23:59:59.000Z

    Using density functional molecular dynamics simulations, we determine the equation of state (EOS) for hydrogen-helium mixtures spanning density-temperature conditions typical of giant-planet interiors, {approx}0.2-9 g cm{sup -3} and 1000-80,000 K for a typical helium mass fraction of 0.245. In addition to computing internal energy and pressure, we determine the entropy using an ab initio thermodynamic integration technique. A comprehensive EOS table with 391 density-temperature points is constructed and the results are presented in the form of a two-dimensional free energy fit for interpolation. Deviations between our ab initio EOS and the semi-analytical EOS model by Saumon and Chabrier are analyzed in detail, and we use the results for initial revision of the inferred thermal state of giant planets with known values for mass and radius. Changes are most pronounced for planets in the Jupiter mass range and below. We present a revision to the mass-radius relationship that makes the hottest exoplanets increase in radius by {approx}0.2 Jupiter radii at fixed entropy and for masses greater than {approx}0.5 Jupiter mass. This change is large enough to have possible implications for some discrepant ''inflated giant exoplanets''.

  14. A potential-splitting approach applied to the Temkin-Poet model for electron scattering off the hydrogen atom and the helium ion

    E-Print Network [OSTI]

    Yarevsky, E; Larson, Ĺ; Elander, N

    2014-01-01T23:59:59.000Z

    The study of scattering processes in few body systems is a difficult problem especially if long range interactions are involved. In order to solve such problems, we develop here a potential-splitting approach for three body systems. This approach is based on splitting the reaction potential into a finite range core part and a long range tail part. The solution to the Schr\\"odinger equation for the long range tail Hamiltonian is found analytically, and used as an incoming wave in the three body scattering problem. This reformulation of the scattering problem makes it suitable for treatment by the exterior complex scaling technique in the sense that the problem after the complex dilation is reduced to a boundary value problem with zero boundary conditions. We illustrate the method with calculations on the electron scattering off the hydrogen atom and the positive helium ion in the frame of the Temkin-Poet model.

  15. Time evolution of the exponential wavenumber spectra of turbulence upon helium injection into a hydrogen discharge at the FT-2 tokamak

    SciTech Connect (OSTI)

    Gurchenko, A. D.; Gusakov, E. Z.; Lashkul, S. I.; Altukhov, A. B.; Selyunin, E. P.; Esipov, L. A.; Kantor, M. Yu.; Kouprienko, D. V.; Stepanov, A. Yu. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

    2013-05-15T23:59:59.000Z

    The effect of variations in the key parameter of short-wavelength turbulence-the ion-acoustic Larmor radius {rho}{sub s}, which determines the position of the maximum of the drift instability growth rate over poloidal wavenumbers-was studied experimentally at the FT-2 tokamak. For this purpose, helium was injected to hydrogen plasma, which resulted in a change in the electron temperature at the plasma edge. The universality of the exponential shape of the turbulence spectra over radial wavenumbers q and a substantial excess of the characteristic turbulence scale L over the ion-acoustic Larmor radius was confirmed with the help of correlative diagnostics of enhanced scattering. This excess at the discharge periphery reaches a value of 3-5 at a low electron temperature, apparently, due to an increase in the dissipation of drift waves upon their cascade transfer toward short scale-lengths.

  16. CODE OF PRACTICE HYDROGEN SULFIDE

    E-Print Network [OSTI]

    Machel, Hans

    into the lungs. Short term exposure may cause irritation of nose, throat, eyes and lungs. The Alberta, throat and lung irritation; digestive upset and loss of appetite; sense of smell starts to become, throat and lung irritation; ability to smell odour completely disappears. 250 ­ 500 Pulmonary edema

  17. Method for producing hydrogen

    SciTech Connect (OSTI)

    Preston, J.L.

    1980-02-26T23:59:59.000Z

    In a method for producing high quality hydrogen, the carbon monoxide level of a hydrogen stream which also contains hydrogen sulfide is shifted in a bed of iron oxide shift catalyst to a desired low level of carbon monoxide using less catalyst than the minimum amount of catalyst which would otherwise be required if there were no hydrogen sulfide in the gas stream. Under normal operating conditions the presence of even relatively small amounts of hydrogen sulfide can double the activity of the catalyst such that much less catalyst may be used to do the same job.

  18. Process for producing cadmium sulfide on a cadmium telluride surface

    DOE Patents [OSTI]

    Levi, D.H.; Nelson, A.J.; Ahrenkiel, R.K.

    1996-07-30T23:59:59.000Z

    A process is described for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness. 12 figs.

  19. Shock compression of liquid helium and helium-hydrogen mixtures : development of a cryogenic capability for shock compression of liquid helium on Z, final report for LDRD Project 141536.

    SciTech Connect (OSTI)

    Lopez, Andrew J.; Knudson, Marcus D.; Shelton, Keegan P.; Hanson, David Lester

    2010-10-01T23:59:59.000Z

    This final report on SNL/NM LDRD Project 141536 summarizes progress made toward the development of a cryogenic capability to generate liquid helium (LHe) samples for high accuracy equation-of-state (EOS) measurements on the Z current drive. Accurate data on He properties at Mbar pressures are critical to understanding giant planetary interiors and for validating first principles density functional simulations, but it is difficult to condense LHe samples at very low temperatures (<3.5 K) for experimental studies on gas guns, magnetic and explosive compression devices, and lasers. We have developed a conceptual design for a cryogenic LHe sample system to generate quiescent superfluid LHe samples at 1.5-1.8 K. This cryogenic system adapts the basic elements of a continuously operating, self-regulating {sup 4}He evaporation refrigerator to the constraints of shock compression experiments on Z. To minimize heat load, the sample holder is surrounded by a double layer of thermal radiation shields cooled with LHe to 5 K. Delivery of LHe to the pumped-He evaporator bath is controlled by a flow impedance. The LHe sample holder assembly features modular components and simplified fabrication techniques to reduce cost and complexity to levels required of an expendable device. Prototypes have been fabricated, assembled, and instrumented for initial testing.

  20. Separating hydrogen from coal gasification gases with alumina membranes

    SciTech Connect (OSTI)

    Egan, B.Z. (Oak Ridge National Lab., TN (USA)); Fain, D.E.; Roettger, G.E.; White, D.E. (Oak Ridge K-25 Site, TN (USA))

    1991-01-01T23:59:59.000Z

    Synthesis gas produced in coal gasification processes contains hydrogen, along with carbon monoxide, carbon dioxide, hydrogen sulfide, water, nitrogen, and other gases, depending on the particular gasification process. Development of membrane technology to separate the hydrogen from the raw gas at the high operating temperatures and pressures near exit gas conditions would improve the efficiency of the process. Tubular porous alumina membranes with mean pore radii ranging from about 9 to 22 {Angstrom} have been fabricated and characterized. Based on hydrostatic tests, the burst strength of the membranes ranged from 800 to 1600 psig, with a mean value of about 1300 psig. These membranes were evaluated for separating hydrogen and other gases. Tests of membrane permeabilities were made with helium, nitrogen, and carbon dioxide. Measurements were made at room temperature in the pressure range of 15 to 589 psi. Selected membranes were tested further with mixed gases simulating a coal gasification product gas. 5 refs., 7 figs.

  1. Modification of the EIC hydrogen sulfide abatement process to produce valuable by-products. Final report, May 4, 1981-May 4, 1982

    SciTech Connect (OSTI)

    Offenhartz, P. O'D.

    1982-06-01T23:59:59.000Z

    A program of analytical and experimental studies has been carried out to develop modifications of the CUPROSUL process for the desulfurization of geothermal steam. The objective of the program was to devise practical means to manipulate the chemistry of the process so that the consumption of raw materials could be controlled and a variety of valuable by-products could be produced. The process had been demonstrated, at one-tenth commercial scale, for steam of the Geysers' average composition in a configuration which resulted in essentially complete oxidation of sulfide to sulfate. The ability to control the extent of oxidation would increase process flexibility and extend its range of applicability to steams of widely varying composition. Preliminary market surveys of raw materials required for the process and by-products which could be produced indicated that controlling the oxidation of sulfides to produce elemental sulfur would probably be the preferred process option. Use of lime to treat sulfate-containing purge streams to produce by-product gypsum and ammonia for recycle or sale could also be justified for certain steam compositions. Recovery of ammonium sulfate alone from the purge stream would not normally be justified unless corecovery of other valuable by-products, such as boric acid, was possible at incremental cost. It was found that ferric sulfate was a highly effective, selective oxidant for the controlled oxidation of copper sulfide solids to produce elemental sulfur for sale and copper sulfate for recycle.

  2. Measurements of the volt-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps

    SciTech Connect (OSTI)

    Klas, M.; Matej?ik, Š. [Department of Experimental Physics, Comenius University, Mlynskadolina F2, 84248 Bratislava (Slovakia); Radjenovi?, B.; Radmilovi?-Radjenovi?, M. [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

    2014-10-15T23:59:59.000Z

    The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1??m and 100??m. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100??m interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.

  3. Gas Diffusion in Metals: Fundamental Study of Helium-Point Defect Interactions in Iron and Kinetics of Hydrogen Desorption from Zirconium Hydride

    E-Print Network [OSTI]

    Hu, Xunxiang

    2013-01-01T23:59:59.000Z

    Kohyama, A. Hishinuma, D.S. Gelles, R.L. Klueh, W. Dietz, K.J. Nucl. Mater. D.S. Gelles. On quantification of helium

  4. Molybdenum sulfide/carbide catalysts

    SciTech Connect (OSTI)

    Alonso, Gabriel (Chihuahua, MX); Chianelli, Russell R. (El Paso, TX); Fuentes, Sergio (Ensenada, MX); Torres, Brenda (El Paso, TX)

    2007-05-29T23:59:59.000Z

    The present invention provides methods of synthesizing molybdenum disulfide (MoS.sub.2) and carbon-containing molybdenum disulfide (MoS.sub.2-xC.sub.x) catalysts that exhibit improved catalytic activity for hydrotreating reactions involving hydrodesulfurization, hydrodenitrogenation, and hydrogenation. The present invention also concerns the resulting catalysts. Furthermore, the invention concerns the promotion of these catalysts with Co, Ni, Fe, and/or Ru sulfides to create catalysts with greater activity, for hydrotreating reactions, than conventional catalysts such as cobalt molybdate on alumina support.

  5. Helium Ion Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Helium Ion Microscope Helium Ion Microscope The Helium Ion Microscope promises to advance biological, geochemical, biogeochemical, and surfaceinterface studies using its combined...

  6. Helium Ion Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Helium Ion Microscope Helium Ion Microscope Bruce Arey discusses the capabilities of EMSL's new helium ion microscope housed in EMSL's Quiet Wing....

  7. Synthesis of Low-Melting Metal Oxide and Sulfide Nanowires and Nanobelts

    E-Print Network [OSTI]

    Daraio, Chiara

    such as oxygen/hydrogen mixture for oxides and H2S for sulfides. In the case of b-Ga2O3 and SnO2, a change with the sulfide nanowires suggest that H2S reacts directly at the molten metal surface to form gallium sulfide to either oxygen or H2S at an elevated temperature. EXPERIMENTAL The synthesis of the nanowires

  8. C. Plennevaux et al., Electrochemistry Communications 26 (2013) 1720 Contribution of CO2 on hydrogen evolution and hydrogen permeation in low

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2013-01-01T23:59:59.000Z

    on hydrogen evolution and hydrogen permeation in low alloy steels exposed to H2S environment C. Plennevauxa Cedex 69621, FRANCE Summary Hydrogen charging in low alloy steels is a major problem in oil and gas environments containing hydrogen sulfide (H2S). The risk of sulfide stress cracking (SSC) is usually determined

  9. Evidence for molecular activated recombination of He single ions from particle balance measurements in helium and hydrogen mixture plasmas in PISCES A

    E-Print Network [OSTI]

    Cai, Laizhong

    2008-01-01T23:59:59.000Z

    order to observe the Doppler effect, two mirrors are mountedof Zeeman effect and Doppler effect for hydrogen-like spec-including Zeeman, Doppler, and Stark effects. Due to the

  10. Onboard Hydrogen/Helium Sensors in Support of the Global Technical Regulation: An Assessment of Performance in Fuel Cell Electric Vehicle Crash Tests

    SciTech Connect (OSTI)

    Post, M. B.; Burgess, R.; Rivkin, C.; Buttner, W.; O'Malley, K.; Ruiz, A.

    2012-09-01T23:59:59.000Z

    Automobile manufacturers in North America, Europe, and Asia project a 2015 release of commercial hydrogen fuel cell powered light-duty road vehicles. These vehicles will be for general consumer applications, albeit initially in select markets but with much broader market penetration expected by 2025. To assure international harmony, North American, European, and Asian regulatory representatives are striving to base respective national regulations on an international safety standard, the Global Technical Regulation (GTR), Hydrogen Fueled Vehicle, which is part of an international agreement pertaining to wheeled vehicles and equipment for wheeled vehicles.

  11. Hydrogen-Triggered Type I X-ray Bursts in a Two-Zone Model

    E-Print Network [OSTI]

    Randall L. Cooper; Ramesh Narayan

    2007-02-01T23:59:59.000Z

    We use the two-zone model of Cooper & Narayan to study the onset and time evolution of hydrogen-triggered type I X-ray bursts on accreting neutron stars. At the lowest accretion rates, thermally unstable hydrogen burning ignites helium as well and produces a mixed hydrogen and helium burst. For somewhat higher accretion rates, thermally unstable hydrogen burning does not ignite helium and thus triggers only a weak hydrogen flash. The peak luminosities of weak hydrogen flashes are typically much lower than the accretion luminosity. These results are in accord with previous theoretical work. We find that a series of weak hydrogen flashes generates a massive layer of helium that eventually ignites in an energetic pure helium flash. Although previously conjectured, this is the first time such bursting behavior has been actually demonstrated in a theoretical model. For yet higher accretion rates, hydrogen burning is thermally stable and thus steadily generates a layer of helium that ultimately ignites in a pure helium flash. We find that, for a narrow range of accretion rates between the mixed hydrogen and helium burst and weak hydrogen flash regimes, unstable hydrogen burning ignites helium only after a short series of weak hydrogen flashes has generated a sufficiently deep layer of helium. These bursts have fluences that are intermediate between those of normal mixed hydrogen and helium bursts and energetic pure helium flashes.

  12. Purification of sulfide oxidase from rat liver

    E-Print Network [OSTI]

    Pu, Lixia

    1994-01-01T23:59:59.000Z

    The present study represents an initial investigative effort to purify sulfide oxidase from rat liver. Two methods to determine sulfide oxidase activity have been established and both are based on measuring substrate disappearance of sulfide. Both...

  13. Oxidative Remobilization of Technetium Sequestered by Sulfide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent Iron. Oxidative Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent...

  14. UNCORRECTEDPROOF The effect of temperature on the adsorption rate of hydrogen

    E-Print Network [OSTI]

    Van Zee, John W.

    size, and low operating temperatures. In a ``hydrogen challenged'' economy, the fuel for the PEMFCsUNCORRECTEDPROOF DTD 5 The effect of temperature on the adsorption rate of hydrogen sulfide on Pt adsorbed at lower temperatures. A value of the activation energy of hydrogen sulfide adsorption on Pt

  15. PRODUCTION OF HYDROGEN BY SUPERADIABATIC DECOMPOSITION OF HYDROGEN SULFIDE

    E-Print Network [OSTI]

    NREL/CP-610-32405 #12;As a logical extension of our ongoing process development efforts, GTI plans concentrated mainly on the superadiabatic reactor, and has comprised computational modeling and experimental concept, using H2S-N2-O2 gas mixtures. Theoretical (numerical modeling) studies at UIC and collaborative

  16. Hydrogen-permeable composite metal membrane and uses thereof

    DOE Patents [OSTI]

    Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR)

    1993-06-08T23:59:59.000Z

    Various hydrogen production and hydrogen sulfide decomposition processes are disclosed that utilize composite metal membranes that contain an intermetallic diffusion barrier separating a hydrogen-permeable base metal and a hydrogen-permeable coating metal. The barrier is a thermally stable inorganic proton conductor.

  17. SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE

    E-Print Network [OSTI]

    Richardson, John

    SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind theoretical work in which enhancements of coronal helium lead to stagnation of the escaping proton flux

  18. Cooling with Superfluid Helium

    E-Print Network [OSTI]

    Lebrun, P

    2014-01-01T23:59:59.000Z

    The technical properties of helium II (‘superfluid’ helium) are presented in view of its applications to the cooling of superconducting devices, particularly in particle accelerators. Cooling schemes are discussed in terms of heat transfer performance and limitations. Large-capacity refrigeration techniques below 2 K are reviewed, with regard to thermodynamic cycles as well as process machinery. Examples drawn from existing or planned projects illustrate the presentation. Keywords: superfluid helium, cryogenics

  19. Hydrogen cryomagnetics: the way forward for superconductivity Glowacki B. A.

    E-Print Network [OSTI]

    Glowacki, Bartek A.

    their helium dependence. Because helium is a by-product of natural gas production, and its value is very small compared with the value of natural gas (although it costs more per MCF, the raw helium concentration superconductivity interlocked with hydrogen economy can be the solution to most of our energy and transport problems

  20. A Crossed Beam and ab Initio Investigation of the Reaction of Hydrogen Sulfide, H2S(X1A1), with Dicarbon Molecules, C2(X1g

    E-Print Network [OSTI]

    Kaiser, Ralf I.

    alternative pathways, the elimination of atomic and molecular hydrogen from a thioketene (H2CCS) intermediate, to synthesize HCCS and CCS are also discussed. 1. Introduction Investigating the formation of sulfur bearing molecules.11 However. despite the potential key role of HCnS isomers to understand the organosulfur

  1. The Primordial Helium Abundance

    E-Print Network [OSTI]

    Manuel Peimbert

    2008-11-18T23:59:59.000Z

    I present a brief review on the determination of the primordial helium abundance by unit mass, Yp. I discuss the importance of the primordial helium abundance in: (a) cosmology, (b) testing the standard big bang nucleosynthesis, (c) studying the physical conditions in H II regions, (d) providing the initial conditions for stellar evolution models, and (e) testing the galactic chemical evolution models.

  2. Wet oxidation of oil-bearing sulfide wastes

    SciTech Connect (OSTI)

    Miller, R.L.; Hotz, N.J.

    1991-01-01T23:59:59.000Z

    Oil-bearing metal sulfide sludges produced in treatment of an industrial wastewater, which includes plating wastes, have yielded to treatment by electrooxidation and hydrogen peroxide processes. The oxidation can be controlled to be mild enough to avoid decomposition of the organic phase while oxidizing the sulfides to sulfates. The pH is controlled to near neutral conditions where iron, aluminum and chromium(III) precipitate as hydrous oxides. Other metals, such as lead and barium, may be present as sulfate precipitates with limited solubility, while metals such as nickel and cadmium would be present as complexed ions in a sulfate solution. The oxidations were found to proceed smoothly, without vigorous reaction; heat liberation was minimal. 2 refs., 12 figs.

  3. DIRECT EVALUATION OF THE HELIUM ABUNDANCES IN OMEGA CENTAURI

    SciTech Connect (OSTI)

    Dupree, A. K.; Avrett, E. H., E-mail: dupree@cfa.harvard.edu, E-mail: eavrett@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2013-08-20T23:59:59.000Z

    A direct measure of the helium abundances from the near-infrared transition of He I at 1.08 {mu}m is obtained for two nearly identical red giant stars in the globular cluster Omega Centauri. One star exhibits the He I line; the line is weak or absent in the other star. Detailed non-local thermal equilibrium semi-empirical models including expansion in spherical geometry are developed to match the chromospheric H{alpha}, H{beta}, and Ca II K lines, in order to predict the helium profile and derive a helium abundance. The red giant spectra suggest a helium abundance of Y {<=} 0.22 (LEID 54064) and Y = 0.39-0.44 (LEID 54084) corresponding to a difference in the abundance {Delta}Y {>=} 0.17. Helium is enhanced in the giant star (LEID 54084) that also contains enhanced aluminum and magnesium. This direct evaluation of the helium abundances gives observational support to the theoretical conjecture that multiple populations harbor enhanced helium in addition to light elements that are products of high-temperature hydrogen burning. We demonstrate that the 1.08 {mu}m He I line can yield a helium abundance in cool stars when constraints on the semi-empirical chromospheric model are provided by other spectroscopic features.

  4. SPECIAL TOPIC: HELIUM NANODROPLETS Experimental studies of helium droplets

    E-Print Network [OSTI]

    Northby, Jan A.

    SPECIAL TOPIC: HELIUM NANODROPLETS Experimental studies of helium droplets J. A. Northbya) Physics September 2001 In this report I will review experimental studies of free helium droplets, with the exception of spectroscopic studies of helium droplets that contain impurities. This particular topic, as well as theoretical

  5. Transition metal sulfide loaded catalyst

    DOE Patents [OSTI]

    Maroni, V.A.; Iton, L.E.; Pasterczyk, J.W.; Winterer, M.; Krause, T.R.

    1994-04-26T23:59:59.000Z

    A zeolite-based catalyst is described for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C[sub 2]+ hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

  6. Stable catalyst layers for hydrogen permeable composite membranes

    DOE Patents [OSTI]

    Way, J. Douglas; Wolden, Colin A

    2014-01-07T23:59:59.000Z

    The present invention provides a hydrogen separation membrane based on nanoporous, composite metal carbide or metal sulfide coated membranes capable of high flux and permselectivity for hydrogen without platinum group metals. The present invention is capable of being operated over a broad temperature range, including at elevated temperatures, while maintaining hydrogen selectivity.

  7. Helium Ash Simulation Studies with Divertor Helium Pumping in JET Internal Transport Barrier Discharges

    E-Print Network [OSTI]

    Helium Ash Simulation Studies with Divertor Helium Pumping in JET Internal Transport Barrier Discharges

  8. The effects of He I 10830 on helium abundance determinations

    E-Print Network [OSTI]

    Aver, Erik; Skillman, Evan D

    2015-01-01T23:59:59.000Z

    Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions provide an independent method for determining the primordial helium abundance, Y_p. Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, & Guseva (2014) have pioneered adding the He 10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He 10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, & Stasinska (2007) and incorporate the newly available observations of He 10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are b...

  9. Alternatives for Helium-3 in Multiplicity Counters

    SciTech Connect (OSTI)

    Ely, James H.; Siciliano, Edward R.; Lintereur, Azaree T.; Swinhoe, Martyn T.

    2013-04-01T23:59:59.000Z

    Alternatives to helium-3 are being actively pursued due to the shortage and rising costs of helium-3. For safeguards applications, there are a number of ongoing investigations to find alternatives that provide the same capability in a cost-effective manner. One of the greatest challenges is to find a comparable alternative for multiplicity counters, since they require high efficiency and short collection or die-away times. Work has been progressing on investigating three commercially available alternatives for high efficiency multiplicity counters: boron trifluoride (BF3) filled proportional tubes, boron-lined proportional tubes, and lithium fluoride with zinc sulfide coated light guides. The baseline multiplicity counter used for the investigation is the Epithermal Neutron Multiplicity Counter with 121 helium-3 filled tubes at 10 atmosphere pressure, which is a significant capability to match. The primary tool for the investigation has been modeling and simulation using the Monte Carlo N-Particle eXtended (MCNPX) radiation transport program, with experiments to validate the models. To directly calculate the coincidence rates in boron-lined (and possibly other) detectors, the MCNPX code has been enhanced to allow the existing coincidence tally to be used with energy deposition rather than neutron capture reactions. This allows boron-lined detectors to be modeled more accurately. Variations of tube number and diameter along with variations in the amount of inter-tube moderator have been conducted for the BF3 and boron-lined cases. Tube pressure was investigated for BF3, up to two atmospheres, as well as optimal boron thickness in the boron-lined tubes. The lithium fluoride was modeled as sheets of material with light guides in between, and the number and thickness of the sheets investigated. The amount of light guide, which in this case doubles as a moderator, was also optimized. The results of these modeling and simulation optimization investigations are described and results presented.

  10. Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description

    SciTech Connect (OSTI)

    SHAPLEY, B.J.

    2000-04-20T23:59:59.000Z

    The purpose of this System Design Description (SDD) is to describe the characteristics of the Cold Vacuum Drying (CVD) Facility general service helium system. The general service helium system is a general service facility process support system, but does include safety-class structures, systems and components (SSCs) providing protection to the offsite public. The general service helium system also performs safety-significant functions that provide protection to onsite workers. The general helium system essential function is to provide helium (He) to support process functions during all phases of facility operations. General service helium is used to purge the cask and the MCO in order to maintain their internal atmospheres below hydrogen flammability concentrations. The general service helium system also supplies helium to purge the process water conditioning (PWC) lines and components and the vacuum purge system (VPS) vacuum pump. The general service helium system, if available following an Safety Class Instrument and Control System (SCIC) Isolation and Purge (IS0 and PURGE) Trip, can provide an alternate general service helium system source to supply the Safety-Class Helium (SCHe) System.

  11. Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description

    SciTech Connect (OSTI)

    FARWICK, C.C.

    1999-07-06T23:59:59.000Z

    This document describes the Cold Vacuum Drying Facility general service helium system (GSHe). The GSHe is a general service facility process support system, but does include safety-class systems, structures and components providing protection to the offsite public. The GSHe also performs safety-significant functions that provide protection to onsite workers. The GSHe essential function is to provide helium to support process functions during all phases of facility operations. GSHe helium is used to purge the cask and the MCO in order to maintain their internal atmospheres below hydrogen flammability concentrations. The GSHe also supplies helium to purge the PWC lines and components and the VPS vacuum pump.

  12. Nanostructures from hydrogen implantation of metals.

    SciTech Connect (OSTI)

    McWatters, Bruce Ray (Sandia National Laboratories, Albuquerque, NM); Causey, Rion A.; DePuit, Ryan J.; Yang, Nancy Y. C.; Ong, Markus D.

    2009-09-01T23:59:59.000Z

    This study investigates a pathway to nanoporous structures created by hydrogen implantation in aluminum. Previous experiments for fusion applications have indicated that hydrogen and helium ion implantations are capable of producing bicontinuous nanoporous structures in a variety of metals. This study focuses specifically on hydrogen and helium implantations of aluminum, including complementary experimental results and computational modeling of this system. Experimental results show the evolution of the surface morphology as the hydrogen ion fluence increases from 10{sup 17} cm{sup -2} to 10{sup 18} cm{sup -2}. Implantations of helium at a fluence of 10{sup 18} cm{sup -2} produce porosity on the order of 10 nm. Computational modeling demonstrates the formation of alanes, their desorption, and the resulting etching of aluminum surfaces that likely drives the nanostructures that form in the presence of hydrogen.

  13. Pellet charge exchange helium measurement using neutral particle analyzer in large helical device

    SciTech Connect (OSTI)

    Ozaki, T.; Goncharov, P.; Veshchev, E.; Tamura, N.; Sudo, S.; Seki, T.; Kasahara, H. [High Energy Particle Group, Wave Heating Group and LHD Experimental Group, National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Takase, Y.; Ohsako, T. [Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561 (Japan)

    2008-10-15T23:59:59.000Z

    It is very important to investigate the confinement of {alpha} particles, which will be produced by nuclear reactions in ITER and fusion reactors. The pellet charge exchange (PCX) measurement is one of the most powerful methods because it can directly provide the profile of the {alpha} particle energy spectra in a plasma. In the large helical device, PCX using tracer encapsulated solid pellet (TESPEL) has been tried in many hydrogen and helium plasmas, including helium accelerated by using the cyclotron resonance heating. In the PCX, we use the compact neutral particle analyzer without simultaneous mass separation ability. The helium particle measurement can be achieved by the application of voltage in the condenser plate. The scattering of hydrogen particle is carefully considered during the estimation of the helium amount. The radial helium profiles can also be obtained by comparing four TESPEL injection shots with/without higher harmonic fast wave heating and at applied plate voltages for He or H, respectively.

  14. Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...

  15. Mining for Helium Jurriaan Hage

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Mining for Helium Jurriaan Hage Peter van Keeken Department of Information and Computing Sciences-year functional programming course using the Helium compiler. The mining of such a collection is not trivial a type error. 1 #12;1 Introduction and motivation When the Helium compiler for learning Haskell

  16. Entanglement in helium

    E-Print Network [OSTI]

    Giuliano Benenti; Stefano Siccardi; Giuliano Strini

    2013-05-01T23:59:59.000Z

    Using a configuration-interaction variational method, we accurately compute the reduced, single-electron von Neumann entropy for several low-energy, singlet and triplet eigenstates of helium atom. We estimate the amount of electron-electron orbital entanglement for such eigenstates and show that it decays with energy.

  17. Material Mixing of Tungsten with Carbon and Helium

    SciTech Connect (OSTI)

    Ueda, Y.; Lee, H. T. [Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan)

    2010-05-20T23:59:59.000Z

    In ITER, graphite and tungsten are used for divertor materials and are mixed through erosion, transport, and redeposition. Helium, a fusion reactant, is an intrinsic element in fusion plasmas that impinges on the metallic wall materials to form He bubbles. W-C mixed layers and He bubble layers greatly affect tritium retention. In this paper, impacts of W-C material mixing on erosion and hydrogen isotope retention are reviewed. Then, recent results on carbon deposition on tungsten in TEXTOR tokamak and helium effects on blistering and retention are discussed.

  18. Helium in Chemically Peculiar Stars

    E-Print Network [OSTI]

    F. Leone

    1998-05-05T23:59:59.000Z

    For the purpose of deriving the helium abundances in chemically peculiar stars, the importance of assuming a correct helium abundance has been investigated for determining the effective temperature and gravity of main sequence B-type stars, making full use of the present capability of reproducing their helium lines. Even if the flux distribution of main sequence B-type stars appears to depend only on the effective temperature for any helium abundance, the effective temperature, gravity and helium abundance have to be determined simultaneously by matching the Balmer line profiles. New MULTI NLTE calculations, performed adopting ATLAS9 model atmospheres and updated helium atomic parameters, reproduce most of the observed equivalent widths of neutral helium lines for main sequence B-type stars and they make us confident of the possibility to correctly derive the helium abundance in chemically peculiar stars. An application of previous methods to the helium rich star HD 37017 shows that helium could be stratified in the magnetic pole regions, as expected in the framework of the diffusion theory in the presence of mass loss.

  19. Acid treatment removes zinc sulfide scale restriction

    SciTech Connect (OSTI)

    Biggs, K. (Kerr McGee Corp., Lafayette, LA (US)); Allison, D. (Otis Engineering Corp., Lafayette, LA (US)); Ford, W.G.F. (Halliburton Co., Duncan, OK (United States))

    1992-08-31T23:59:59.000Z

    This paper reports that removal of zinc sulfide (ZnS) scale with acid restored an offshore Louisiana well's production to original rates. The zinc sulfide scale was determined to be in the near well bore area. The selected acid had been proven to control iron sulfide (FeS) scales in sour wells without causing harm to surface production equipment, tubing, and other downhole hardware. The successful removal of the blockage re-established previous production rates with a 105% increase in flowing tubing pressure. On production for a number of months, a high rate, high-pressure offshore well was experiencing unusually rapid pressure and rate declines. A small sample of the restrictive material was obtained during the wire line operations. The well was subsequently shut in while a laboratory analysis determined that zinc sulfide was the major component of the obstruction.

  20. Adsorption of Hydrogen Sulfide onto Activated Carbon Fibers: Effect of

    E-Print Network [OSTI]

    Borguet, Eric

    . These processes include natural gas processing, petroleum refining, petrochemical plants, Kraft mills, coke ovens, and coal gasifiers. H2S concentrations in these processes vary from 0 to 60 vol % (6). The Claus process

  1. Evaluation of hydrogen sulfide concentrations in Norwegian reservoir fluids

    E-Print Network [OSTI]

    Haland, Kjersti

    1998-01-01T23:59:59.000Z

    exponential relationship between [HZS] and reservoir temperature, the others include additional fluid parameters. This contribution is considered of particular importance for planning [HZS] control strategies and for production management....

  2. PERFORMANCE OF DIPOLE MAGNETS IN HELIUM II

    E-Print Network [OSTI]

    Althaus, R.

    2010-01-01T23:59:59.000Z

    in Pressurized Superfluid Helium", EX5 40 11th InternationalOF DIPOLE MAGNETS IN HELIUM II R. Althaus, S. Cacpi, W.S.OF DIMLE NMMETS IN HELIUM II* R. Althaus, S. Caspl, W.S.

  3. ELECTRONS ON THE SURFACE OF LIQUID HELIUM

    E-Print Network [OSTI]

    Lambert, David Kay

    2011-01-01T23:59:59.000Z

    ON THE SURFACE OF LIQUID HELIUM David Kay Lambert (Ph. D.ON THE SURFACE OF LIQUID HELIUM David Kay Lambert Materialsthe potential well near a helium surface, The charge density

  4. Regimes Of Helium Burning

    E-Print Network [OSTI]

    F. X. Timmes; J. C. Niemeyer

    2000-05-16T23:59:59.000Z

    The burning regimes encountered by laminar deflagrations and ZND detonations propagating through helium-rich compositions in the presence of buoyancy-driven turbulence are analyzed. Particular attention is given to models of X-ray bursts which start with a thermonuclear runaway on the surface of a neutron star, and the thin shell helium instability of intermediate-mass stars. In the X-ray burst case, turbulent deflagrations propagating in the lateral or radial directions encounter a transition from the distributed regime to the flamlet regime at a density of 10^8 g cm^{-3}. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than 10^6 g cm^{-3}. Self-sustained laminar deflagrations travelling in the radial direction cannot exist below this density. Similarily, the planar ZND detonation width becomes larger than the pressure scale height at 10^7 g cm^{-3}, suggesting that a steady-state, self-sustained detonations cannot come into existance in the radial direction. In the thin helium shell case, turbulent deflagrations travelling in the lateral or radial directions encounter the distributed regime at densities below 10^7 g cm^{-3}, and the flamelet regime at larger densities. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than 10^4 g cm^{-3}, indicating that steady-state laminar deflagrations cannot form below this density. The planar ZND detonation width becomes larger than the pressure scale height at 5 10^4 g cm^{-3}, suggesting that steady-state, self-sustained detonations cannot come into existance in the radial direction.

  5. Helium dilution refrigeration system

    DOE Patents [OSTI]

    Roach, P.R.; Gray, K.E.

    1988-09-13T23:59:59.000Z

    A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

  6. Helium dilution refrigeration system

    DOE Patents [OSTI]

    Roach, Patrick R. (Darien, IL); Gray, Kenneth E. (Naperville, IL)

    1988-01-01T23:59:59.000Z

    A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

  7. THE HELIUM ABUNDANCE IN POLAR CORONAL HOLES AND THE FAST SOLAR WIND

    SciTech Connect (OSTI)

    Byhring, H. S., E-mail: hanne-sigrun.byhring@uit.no [Department of Physics and Technology, University of Tromsoe, No-9037 Tromsoe (Norway)

    2011-09-10T23:59:59.000Z

    I have studied the helium abundance in polar coronal holes and the fast solar wind using a time-dependent numerical model for the hydrogen-helium solar wind that spans the mid-to-upper chromosphere, transition region, corona, and solar wind. The model calculates the particle density, flow velocity, parallel and perpendicular temperature, and heat flux for all particle species simultaneously. The focus is on (1) the coronal/solar wind helium abundance as a function of the total magnetic field expansion and (2) the coronal abundance enhancements resulting from low helium heating rates. It is shown that the magnetic field expansion factor may be important in the determination of the solar wind helium abundance and that this can be understood in terms of gravitational settling in the chromosphere. I find that a total magnetic field expansion factor of about 20 is consistent with the observed helium abundance in the solar wind. Furthermore, it is demonstrated that existing observations, both spectroscopic observations of the corona and in situ observations in the solar wind, are compatible with helium abundance enhancements in the corona. For proton-electron plasma properties in accordance with observations, the coronal helium abundance enhancements occur in the region 1.2-2 R{sub sun}.

  8. Hydrogen in Type Ic Supernovae?

    E-Print Network [OSTI]

    David Branch; David J. Jeffery; Timothy R. Young; E. Baron

    2006-05-09T23:59:59.000Z

    By definition, a Type Ic supernova (SN Ic) does not have conspicuous lines of hydrogen or helium in its optical spectrum. SNe Ic usually are modelled in terms of the gravitational collapse of bare carbon-oxygen cores. We consider the possibility that the spectra of ordinary (SN 1994I-like) SNe Ic have been misinterpreted, and that SNe Ic eject hydrogen. An absorption feature usually attributed to a blend of Si II 6355 and C II 6580 may be produced by H-alpha. If SN 1994I-like SNe Ic eject hydrogen, the possibility that hypernova (SN 1998bw-like) SNe Ic, some of which are associated with gamma-ray bursts, also eject hydrogen should be considered. The implications of hydrogen for SN Ic progenitors and explosion models are briefly discussed.

  9. Hydrogen Burning on Magnetar Surfaces

    E-Print Network [OSTI]

    P. Chang; P. Arras; L. Bildsten

    2004-10-18T23:59:59.000Z

    We compute the rate of diffusive nuclear burning for hydrogen on the surface of a "magnetar" (Soft Gamma-Ray Repeater or Anomalous X-Ray Pulsar). We find that hydrogen at the photosphere will be burned on an extremely rapid timescale of hours to years, depending on composition of the underlying material. Improving on our previous studies, we explore the effect of a maximally thick "inert" helium layer, previously thought to slow down the burning rate. Since hydrogen diffuses faster in helium than through heavier elements, we find this helium buffer actually increases the burning rate for magnetars. We compute simple analytic scalings of the burning rate with temperature and magnetic field for a range of core temperature. We conclude that magnetar photospheres are very unlikely to contain hydrogen. This motivates theoretical work on heavy element atmospheres that are needed to measure effective temperature from the observed thermal emission and constrains models of AXPs that rely on magnetar cooling through thick light element envelopes.

  10. Quantum Cavitation: a comparison between superfluid helium-4 and normal liquid helium-3

    E-Print Network [OSTI]

    Caupin, Frédéric

    Quantum Cavitation: a comparison between superfluid helium-4 and normal liquid helium-3 S. Balibar in superfluid helium-4 and in normal liquid helium-3, both theoretically and experimentally. We compare the two by tunneling, to classical cavitation where their nu- cleation is thermally activated. In helium-3, where

  11. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOE Patents [OSTI]

    Eser, Erten; Fields, Shannon

    2012-05-01T23:59:59.000Z

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  12. Hydrogen Cryomagnetics

    E-Print Network [OSTI]

    Glowacki, B. A.; Hanely, E.; Nuttall, W. J.

    2014-01-01T23:59:59.000Z

    in our current approach. The liquefaction of hydrogen allows also for its use in transport applications for example BMW developed a car that utilises liquid hydrogen instead of compressed gas hydrogen making the use of cryogenic hydrogen even more... efficient. 11     Figure 13. Decentralised production of hydrogen pathways for Energy and Hydrogen Cryomagnetic solutions for a hospital environment. The shaded region in the figure represents the decentralised production of hydrogen using renewable...

  13. Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report II.C Fossil-Based

    E-Print Network [OSTI]

    , noncatalytic decomposition of hydrogen sulfide (H2S) in H2S-rich waste streams into hydrogen and elemental at an industrial site. Approach · Develop a numerical model for the superadiabatic H2S decomposition reactor viability of the concept. · Designed and constructed a state-of-the-art superadiabatic H2S decomposition

  14. Iron-sulfide redox flow batteries

    DOE Patents [OSTI]

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17T23:59:59.000Z

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  15. Cadmium zinc sulfide by solution growth

    DOE Patents [OSTI]

    Chen, Wen S. (Seattle, WA)

    1992-05-12T23:59:59.000Z

    A process for depositing thin layers of a II-VI compound cadmium zinc sulfide (CdZnS) by an aqueous solution growth technique with quality suitable for high efficiency photovoltaic or other devices which can benefit from the band edge shift resulting from the inclusion of Zn in the sulfide. A first solution comprising CdCl.sub.2 2.5H.sub.2 O, NH.sub.4 Cl, NH.sub.4 OH and ZnCl.sub.2, and a second solution comprising thiourea ((NH.sub.2).sub.2 CS) are combined and placed in a deposition cell, along with a substrate to form a thin i.e. 10 nm film of CdZnS on the substrate. This process can be sequentially repeated with to achieve deposition of independent multiple layers having different Zn concentrations.

  16. Hydrogen sensor

    DOE Patents [OSTI]

    Duan, Yixiang (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Cao, Wenqing (Katy, TX)

    2010-11-23T23:59:59.000Z

    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.

  17. A Torsional Oscillator Study Solid Helium

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    A Torsional Oscillator Study of Solid Helium George Edgar Marcus Nichols Royal Holloway College and Andy Nichols and Alexandra Zuckermann for theirs out of it. #12;Contents 1 Motivation 10 1.1 Helium

  18. Single-layer transition metal sulfide catalysts

    DOE Patents [OSTI]

    Thoma, Steven G. (Albuquerque, NM)

    2011-05-31T23:59:59.000Z

    Transition Metal Sulfides (TMS), such as molybdenum disulfide (MoS.sub.2), are the petroleum industry's "workhorse" catalysts for upgrading heavy petroleum feedstocks and removing sulfur, nitrogen and other pollutants from fuels. We have developed an improved synthesis technique to produce SLTMS catalysts, such as molybdenum disulfide, with potentially greater activity and specificity than those currently available. Applications for this technology include heavy feed upgrading, in-situ catalysis, bio-fuel conversion and coal liquefaction.

  19. Subsurface heaters with low sulfidation rates

    DOE Patents [OSTI]

    John, Randy Carl; Vinegar, Harold J

    2013-12-10T23:59:59.000Z

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  20. Fine structure of helium and light helium-like ions Krzysztof Pachucki and Vladimir A. Yerokhin

    E-Print Network [OSTI]

    Pachucki, Krzysztof

    1 Fine structure of helium and light helium-like ions Krzysztof Pachucki and Vladimir A. Yerokhin Abstract: Calculational results are presented for the fine-structure splitting of the 23 P state of helium and helium-like ions with the nuclear charge Z up to 10. Theoretical predictions are in agreement

  1. 8 2. Helium und Tritium in der Geosphre 2. Helium und Tritium in der Geosphre

    E-Print Network [OSTI]

    Aeschbach-Hertig, Werner

    8 2. Helium und Tritium in der Geosphäre 2. Helium und Tritium in der Geosphäre 2.1. Spezielle Einheiten und Konstanten An dieser Stelle sollen die speziellen für Helium und Tritium verwendeten Einheiten definiert und dazugehörige Umrechnungen angegeben werden. Die Wahl der Werte einiger für Helium und Tritium

  2. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, R.S.; Todd, R.A.

    1985-04-09T23:59:59.000Z

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  3. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

    1987-01-01T23:59:59.000Z

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  4. Cooling curves and initial models for low-mass white dwarfs (<0.25 Msun) with helium core

    E-Print Network [OSTI]

    Marek J. Sarna; Ene Ergma; Jelena Antipova

    2000-02-11T23:59:59.000Z

    We present a detailed calculation of the evolution of low-mass ($< 0.25~M_\\odot $) helium white dwarfs. These white dwarfs (the optical companions to binary millisecond pulsars) are formed via long-term, low-mass binary evolution. After detachment from the Roche lobe, the hot helium cores have a rather thick hydrogen layer with mass between 0.01 to 0.06$~M_\\odot $. Due to mixing between the core and outer envelope, the surface hydrogen content is 0.5 to 0.35, depending on the initial value of the heavy element (Z) and the initial secondary mass. We found that the majority of our computed models experience one or two hydrogen shell flashes. We found that the mass of the helium dwarf in which the hydrogen shell flash occurs depends on the chemical composition. The minimum helium white dwarf mass in which a hydrogen flash takes place is 0.213$~M_\\odot $ (Z=0.003), 0.198$~M_\\odot $ (Z=0.01), 0.192$~M_\\odot $ (Z=0.02) or 0.183$~M_\\odot $ (Z=0.03). The duration of the flashes (independent of chemical composition) is between few $\\times 10^6 $ years to few $\\times 10^7 $ years. In several flashes the white dwarf radius will increase so much that it forces the model to fill its Roche lobe again. Our calculations show that cooling history of the helium white dwarf depends dramatically on the thickness of the hydrogen layer. We show that the transition from a cooling white dwarf with a temporary stable hydrogen-burning shell to a cooling white dwarf in which almost all residual hydrogen is lost in a few thermal flashes (via Roche-lobe overflow) occurs between 0.183-0.213$~M_\\odot $ (depending on the heavy element value).

  5. Phase and density dependence of the delayed annihilation of metastable antiprotonic helium atoms in gas, liquid and solid helium

    E-Print Network [OSTI]

    Widmann, E; Yamazaki, T; Hayano, R S; Iwasaki, M; Nakamura, S N; Tamura, H; Ito, T M; Kawachi, A; Nishida, N; Higemoto, W; Ito, Y; Morita, N; Hartmann, F J; Daniel, H; Von Egidy, T; Schmid, W; Hoffmann, J; Eades, John

    1995-01-01T23:59:59.000Z

    Phase and density dependence of the delayed annihilation of metastable antiprotonic helium atoms in gas, liquid and solid helium

  6. Metal sulfide initiators for metal oxide sorbent regeneration

    DOE Patents [OSTI]

    Turk, B.S.; Gupta, R.P.

    1999-06-22T23:59:59.000Z

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream. 1 fig.

  7. Sulfide scaling in low enthalpy geothermal environments; A survey

    SciTech Connect (OSTI)

    Criaud, A.; Fouillac, C. (Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France))

    1989-01-01T23:59:59.000Z

    A review of the sulfide scaling phenomena in low-temperature environments is presented. While high-temperature fluids tend to deposit metal sulfides because of their high concentrations of dissolved metals and variations of temperature, pressure and fluid chemistry, low temperature media are characterized by very low metal content but much higher dissolved sulfide. In the case of the goethermal wells of the Paris Basin, detailed studies demonstrate that the relatively large concentrations of chloride and dissolved sulfide are responsible for corrosion and consequent formation of iron sulfide scale composed of mackinawite, pyrite and pyrrhotite. The effects of the exploitation schemes are far less important than the corrosion of the casings. The low-enthalpy fluids that do not originate from sedimentary aquifers (such as in Iceland and Bulgaria), have a limited corrosion potential, and the thin sulfide film that appears may prevent the progress of corrosion.

  8. Synthesis Of [2h, 13c] And [2h3, 13c]Methyl Aryl Sulfides

    DOE Patents [OSTI]

    Martinez, Rodolfo A. (Santa Fe, NM); Alvarez, Marc A. (Santa Fe, NM); Silks, III, Louis A. (Los Alamos, NM); Unkefer, Clifford J. (Los Alamos, NM)

    2004-03-30T23:59:59.000Z

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2,.sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms. The present invention is also directed to the labeled compounds of [.sup.2 H.sub.1, .sup.13 C]methyl iodide and [.sup.2 H.sub.2, .sup.13 C]methyl iodide.

  9. QUANTUM STATISTICS OF METASTABLE LIQUID HELIUM

    E-Print Network [OSTI]

    Caupin, Frédéric

    QUANTUM STATISTICS OF METASTABLE LIQUID HELIUM FR´ED´ERIC CAUPIN AND S´EBASTIEN BALIBAR Laboratoire in the spinodal line of liquid helium 3, for which experimental evidence has been reported. The calculations in the case of superfluid helium 4; we also consider the overpressurized region, and the location

  10. Mining Helium programs with Neon Jurriaan Hage

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Mining Helium programs with Neon Jurriaan Hage Peter van Keeken Department of Information in a first-year functional programming course using the Helium compiler. The mining of such a collection to resolve a type error. 1 #12;1 Introduction and motivation When the Helium compiler for learning Haskell

  11. Characterization of reconnecting vortices in superfluid helium

    E-Print Network [OSTI]

    Texas at Austin. University of

    Characterization of reconnecting vortices in superfluid helium Gregory P. Bewley*, Matthew S experimental observations of reconnection between quantized vortices in superfluid helium. We do so by imaging. reconnection Vorticity in superfluid helium is confined to filaments that are only angstroms in diameter

  12. Circuit Quantum Electrodynamics with Electrons on Helium

    E-Print Network [OSTI]

    Circuit Quantum Electrodynamics with Electrons on Helium A Dissertation Presented to the Faculty Fragner All rights reserved. ii #12;Abstract Circuit Quantum Electrodynamics with Electrons on Helium helium. Such a system represents a solid-state, electrical circuit analog of atomic cavity QED in which

  13. Helium Migration in Iron Christ's College

    E-Print Network [OSTI]

    Cambridge, University of

    Helium Migration in Iron Y. Zhang Christ's College Department of Materials Science and Metallurgy the achievement at all. ii #12;Abstract A theoretical model of helium migration in body centred cubic (BCC)structure irons has been developed using the concept of the effective helium diffusion coeffi- cient

  14. Design progress of cryogenic hydrogen system for China Spallation Neutron Source

    SciTech Connect (OSTI)

    Wang, G. P.; Zhang, Y.; Xiao, J.; He, C. C.; Ding, M. Y.; Wang, Y. Q.; Li, N.; He, K. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P.R. (China)

    2014-01-29T23:59:59.000Z

    China Spallation Neutron Source (CSNS) is a large proton accelerator research facility with 100 kW beam power. Construction started in October 2011 and is expected to last 6.5 years. The cryogenic hydrogen circulation is cooled by a helium refrigerator with cooling capacity of 2200 W at 20 K and provides supercritical hydrogen to neutron moderating system. Important progresses of CSNS cryogenic system were concluded as follows. Firstly, process design of cryogenic system has been completed including helium refrigerator, hydrogen loop, gas distribution, and safety interlock. Secondly, an accumulator prototype was designed to mitigate pressure fluctuation caused by dynamic heat load from neutron moderation. Performance test of the accumulator has been carried out at room and liquid nitrogen temperature. Results show the accumulator with welding bellows regulates hydrogen pressure well. Parameters of key equipment have been identified. The contract for the helium refrigerator has been signed. Mechanical design of the hydrogen cold box has been completed, and the hydrogen pump, ortho-para hydrogen convertor, helium-hydrogen heat exchanger, hydrogen heater, and cryogenic valves are in procurement. Finally, Hydrogen safety interlock has been finished as well, including the logic of gas distribution, vacuum, hydrogen leakage and ventilation. Generally, design and construction of CSNS cryogenic system is conducted as expected.

  15. Synthesis of actinide nitrides, phosphides, sulfides and oxides

    DOE Patents [OSTI]

    Van Der Sluys, William G. (Missoula, MT); Burns, Carol J. (Los Alamos, NM); Smith, David C. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

    A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g., uranium mononitride, by subliming an actinide organometallic precursor, e.g., a uranium amide precursor, in the presence of an effectgive amount of a protic Lewis base, e.g., ammonia, within a reactor at temperatures and for time sufficient to form a thin film of the actinide compound, are disclosed.

  16. Ocean color and atmospheric dimethyl sulfide: On their mesoscale variability

    E-Print Network [OSTI]

    Matrai, Patricia A; Balch, William M; Cooper, David J; Saltzman, Eric S

    1993-01-01T23:59:59.000Z

    periods of' time, covering mesoscale Campbell, J. W. and W.Dimethyl Sulfide' On Their Mesoscale Variability PATRICIA A.Miami, Miami, Florida The mesoscale variability of dimethyl

  17. THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. IV. HELIUM AND CARBON RECOMBINATION LINES

    SciTech Connect (OSTI)

    Wenger, Trey V.; Bania, T. M. [Astronomy Department, 725 Commonwealth Avenue, Boston University, Boston, MA 02215 (United States)] [Astronomy Department, 725 Commonwealth Avenue, Boston University, Boston, MA 02215 (United States); Balser, Dana S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA, 22903-2475 (United States)] [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA, 22903-2475 (United States); Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)

    2013-02-10T23:59:59.000Z

    The Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region targets. Since the HRDS nebulae lie at large distances from the Sun, they are located in previously unprobed zones of the Galactic disk. Here, we derive the properties of helium and carbon RRL emission from HRDS nebulae. Our target sample is the subset of the HRDS that has visible helium or carbon RRLs. This criterion gives a total of 84 velocity components (14% of the HRDS) with helium emission and 52 (9%) with carbon emission. For our highest quality sources, the average {sup 4}He{sup +}/H{sup +} abundance ratio by number, (y {sup +}), is 0.068 {+-} 0.023(1{sigma}). This is the same ratio as that measured for the sample of previously known Galactic H II regions. Nebulae without detected helium emission give robust y {sup +} upper limits. There are 5 RRL emission components with y {sup +} less than 0.04 and another 12 with upper limits below this value. These H II regions must have either a very low {sup 4}He abundance or contain a significant amount of neutral helium. The HRDS has 20 nebulae with carbon RRL emission but no helium emission at its sensitivity level. There is no correlation between the carbon RRL parameters and the 8 {mu}m mid-infrared morphology of these nebulae.

  18. Code for Hydrogen Hydrogen Pipeline

    E-Print Network [OSTI]

    #12;2 Code for Hydrogen Pipelines Hydrogen Pipeline Working Group Workshop Augusta, Georgia August development · Charge from BPTCS to B31 Standards Committee for Hydrogen Piping/Pipeline code development · B31.12 Status & Structure · Hydrogen Pipeline issues · Research Needs · Where Do We Go From Here? #12;4 Code

  19. MATHEMATICAL MODELING OF THE LITHIUM-ALUMINUM, IRON SULFIDE BATTERY. I. GALVONOSTATIC DISCHARGE BEHAVIOR

    E-Print Network [OSTI]

    Pollard, Richard

    2012-01-01T23:59:59.000Z

    composition profiles in lithium/sulfur battery analogues hasTHE LITHIUM-ALUMINUM, IRON SULFIDE BATTERY. I. GALVONOSTATICthe Lithium-Aluminum, Iron Sulfide Battery I. Galvanostatic

  20. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, S.J.; McCarley, R.E.; Schrader, G.L.; Xie, X.B.

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M{sup n+}{sub 2x/n}(L{sub 6}S{sub 8})S{sub x}, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M{sub 6}S{sub 8}){sup 0} cluster units are present. Vacuum thermolysis of the amorphous Na{sub 2x}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH first produces poorly crystalline NaMo{sub 6}S{sub 8} by disproportionation at 800 C and well-crystallized NaMo{sub 6}S{sub 8} at {>=} 900 C. Ion-exchange of the sodium material in methanol with soluble M{sup 2+} and M{sup 3+} salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M{sup n+}{sub 2x/n}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M{sup n+}{sub 2x/n}Mo{sub 6}S{sub 8+x}(MeOH){sub y}[MMOS] (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as ``Chevrel phase-like`` in that both contain Mo{sub 6}S{sub 8} cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst is shown to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS{sub 2} catalysts. 9 figs.

  1. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, Shane J. (Ames, IA); McCarley, Robert E. (Ames, IA); Schrader, Glenn L. (Ames, IA); Xie, Xiaobing (College Station, TX)

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M.sup.n+.sub.2x/n (L.sub.6 S.sub.8)S.sub.x, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M.sub.6 S.sub.8).sup.0 cluster units are present. Vacuum thermolysis of the amorphous Na.sub.2x (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH first produces poorly crystalline NaMo.sub.6 S.sub.8 by disproportionation at 800.degree. C. and well-crystallized NaMo.sub.6 S.sub.8 at .gtoreq. 900.degree. C. Ion-exchange of the sodium material in methanol with soluble M.sup.2+ and M.sup.3+ salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M.sup.n+.sub.2x/n (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M.sup.n+.sub.2x/n Mo.sub.6 S.sub.8+x (MeOH).sub.y ›MMOS! (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as "Chevrel phase-like" in that both contain Mo.sub.6 S.sub.8 cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst showed to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS.sub.2 catalysts.

  2. The Liquefaction of Hydrogen and Helium Using Small Coolers

    E-Print Network [OSTI]

    Green, Michael A.

    2006-01-01T23:59:59.000Z

    with the extra compressor and the problem of clogging a J-Ttheir compressors, but one also has the reliability problems

  3. Microwave-excited microplasma thruster with helium and hydrogen propellants

    SciTech Connect (OSTI)

    Takahashi, Takeshi; Takao, Yoshinori; Ichida, Yugo; Eriguchi, Koji; Ono, Kouichi [Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

    2011-06-15T23:59:59.000Z

    Microplasma thruster of electrothermal type has been investigated with feed or propellant gases of He and H{sub 2}. The thruster consisted of an azimuthally symmetric microwave-excited microplasma source 1.5 mm in diameter and 10 mm long with a rod antenna on axis, and a converging-diverging micronozzle 1 mm long with a throat 0.2 mm in diameter. Surface wave-excited plasmas were established by 4.0-GHz microwaves at powers of {<=} 6 W, with the source pressure in the range 0.5-12 kPa at flow rates of 2-70 sccm. The microplasma generation, micronozzle flow, and thrust performance with He were numerically analyzed by using a two-dimensional fluid model, coupled with an electromagnetic model for microwaves interacting with plasmas in the source region. In experiments, the plasma electron density and gas temperature in the microplasma source were measured at around the top of the microwave antenna, or just upstream of the micronozzle inlet, by optical emission spectroscopy with a small amount of additive gases of H{sub 2} and N{sub 2}. In the case of He propellant, the Stark broadening of H Balmer-{beta} line and the vibronic spectrum of N{sub 2} 2nd positive (0, 2) band indicated that the electron density was in the range (2-5)x10{sup 19}m{sup -3} and the gas or rotational temperature was in the range 600-700 K. The thrust performance was also measured by using a target-type microthrust stand, giving a thrust in the range 0.04-0.51 mN, a specific impulse in the range 150-270 s, and a thrust efficiency in the range 2%-12%. These experimental results were consistent with those of numerical analysis, depending on microwave power and gas flow rate. Similar plasma characteristics and thrust performance were obtained with H{sub 2} propellant, where the specific impulse of {<=} 450 s was more than 1.5 times higher than that with He, owing to a difference in mass between He and H{sub 2}. A comparison with previous studies with Ar propellant [T. Takahashi et al., Phys. Plasmas 16, 083505 (2009)] indicated that in the presence as well as absence of plasma discharge, the specific impulse was enhanced by more than 3-5 times with light-mass propellants He and H{sub 2} as has been known for large-scale propulsion systems. Thus, it follows that in the microplasma thruster of electrothermal type, the high diffusivity and thermal conductivity of He and H{sub 2} in the microplasma source of high surface-to-volume ratios do not lead to a deterioration of the thrust performance, primarily owing to a more significant thermal energy gain due to elastic collisions between electrons and heavy particles in He and H{sub 2}.

  4. The Liquefaction of Hydrogen and Helium Using Small Coolers

    E-Print Network [OSTI]

    Green, Michael A.

    2006-01-01T23:59:59.000Z

    the cooler across the press fit joint will also be measuredon the shield near the press fit interface and the diode on

  5. Liquid Hydrogen Delivery - Strategic Directions for Hydrogen...

    Broader source: Energy.gov (indexed) [DOE]

    Liquid Hydrogen Delivery - Strategic Directions for Hydrogen Delivery Workshop Liquid Hydrogen Delivery - Strategic Directions for Hydrogen Delivery Workshop Targets, barriers and...

  6. Preventing oxidation of iron sulfide minerals by polyethylene polyamines

    E-Print Network [OSTI]

    Belzile, Nelson

    processes of sulfide minerals still remains an important issue for both mineral extraction and environmentalPreventing oxidation of iron sulfide minerals by polyethylene polyamines Yu-Wei Chen a,*, Yuerong on the passivation of pyrite and pyrrhotite minerals. Polyethylene polyamines, such as triethylenetetramine (TETA

  7. Confined helium on Lagrange meshes

    E-Print Network [OSTI]

    Baye, Daniel

    2015-01-01T23:59:59.000Z

    The Lagrange-mesh method has the simplicity of a calculation on a mesh and can have the accuracy of a variational method. It is applied to the study of a confined helium atom. Two types of confinement are considered. Soft confinements by potentials are studied in perimetric coordinates. Hard confinement in impenetrable spherical cavities is studied in a system of rescaled perimetric coordinates varying in [0,1] intervals. Energies and mean values of the distances between electrons and between an electron and the helium nucleus are calculated. A high accuracy of 11 to 15 significant figures is obtained with small computing times. Pressures acting on the confined atom are also computed. For sphere radii smaller than 1, their relative accuracies are better than $10^{-10}$. For larger radii up to 10, they progressively decrease to $10^{-3}$, still improving the best literature results.

  8. Hydrogen cooling options for MgB{sub 2}-based superconducting systems

    SciTech Connect (OSTI)

    Stautner, W.; Xu, M.; Mine, S.; Amm, K. [Electromagnetics and Superconductivity Lab, GE Global Research, Niskayuna, NY 12309 (United States)

    2014-01-29T23:59:59.000Z

    With the arrival of MgB{sub 2} for low-cost superconducting magnets, hydrogen cooling has become an interesting alternative to costly liquid helium. Hydrogen is generally regarded as the most efficient coolant in cryogenics and, in particular, is well suited for cooling superconducting magnets. Cooling methods need to take into account the specific quench propagation in the MgB{sub 2} magnet winding and facilitate a cryogenically reliable and safe cooling environment. The authors propose three different multi-coolant options for MRI scanners using helium or hydrogen within the same design framework. Furthermore, a design option for whole-body scanners which employs technology, components, fueling techniques and safety devices from the hydrogen automotive industry is presented, continuing the trend towards replacing helium with hydrogen as a safe and cost efficient coolant.

  9. The Epoch of Helium Reionization

    E-Print Network [OSTI]

    Aaron Sokasian; Tom Abel; Lars. E. Hernquist

    2001-12-14T23:59:59.000Z

    We study the reionization of Helium II by quasars using a numerical approach that combines 3D radiative transfer calculations with cosmological hydrodynamical simulations. Sources producing the ionizing radiation are selected according to an empirical quasar luminosity function and are assigned luminosities according to their intrinsic masses. We present models in which these parameters are varied and examine characteristics of the resultant reionization process that distinguish the various cases. In addition, we extract artificial spectra from the simulations and quantify statistical properties of the spectral features in each model. We find that the most important factor affecting the evolution of He II reionization is the cumulative number of ionizing photons that are produced by the sources. Comparisons between He II opacities measured observationally and those obtained by our analysis reveal that the available ranges in plausible values for the parameters provide enough leeway to provide a satisfactory match. However, one property common to all our calculations is that the epoch of Helium II reionization must have occurred at a redshift between 3 < z < 4. If so, future observational programs will be able to directly trace the details of the ionization history of helium and probe the low density phase of the intergalactic medium during this phase of the evolution of the Universe.

  10. Hydrogen Storage

    Fuel Cell Technologies Publication and Product Library (EERE)

    This 2-page fact sheet provides a brief introduction to hydrogen storage technologies. Intended for a non-technical audience, it explains the different ways in which hydrogen can be stored, as well a

  11. Hydrogen Safety

    Fuel Cell Technologies Publication and Product Library (EERE)

    This 2-page fact sheet, intended for a non-technical audience, explains the basic properties of hydrogen and provides an overview of issues related to the safe use of hydrogen as an energy carrier.

  12. Hydrogen Analysis

    Broader source: Energy.gov (indexed) [DOE]

    A H2A: Hydrogen Analysis Margaret K. Mann DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. H2A Charter...

  13. Effective hydrogen generation and resource circulation based on sulfur cycle system

    SciTech Connect (OSTI)

    Takahashi, Hideyuki; Mabuchi, Takashi; Hayashi, Tsugumi; Yokoyama, Shun; Tohji, Kazuyuki [Graduate School of Environmental Studies, Tohoku University 6-6-20, Aramaki, Aoba-ku, Sendai, 980-8579 (Japan)

    2013-12-10T23:59:59.000Z

    For the effective hydrogen generation from H{sub 2}S, it should be compatible that the increscent of the photocatalytic (or electrochemical) activities and the development of effective utilization method of by-products (poly sulfide ion). In this study, “system integration” to construct the sulfur cycle system, which is compatible with the increscent of the hydrogen and or electron energy generation ratio and resource circulation, is investigated. Photocatalytic hydrogen generation rate can be enhanced by using stratified photocatalysts. Photo excited electron can be transpired to electrode to convert the electron energy to hydrogen energy. Poly sulfide ion as the by-products can be transferred into elemental sulfur and/or industrial materials such as rubber. Moreover, elemental sulfur can be transferred into H{sub 2}S which is the original materials for hydrogen generation. By using this “system integration”, the sulfur cycle system for the new energy generation can be constructed.

  14. Helium in Near Earth Orbit The AMS Collaboration

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Helium in Near Earth Orbit The AMS Collaboration Abstract The helium spectrum from 0.1 to 100 Ge the geomagnetic cutoff a second helium spectrum was observed. In the second he- lium spectra over the energy range ninety percent of the helium was deter- mined to be 3 He (at the 90 % CL). Tracing helium from the second

  15. Hydrogen Storage Technologies Hydrogen Delivery

    E-Print Network [OSTI]

    Hydrogen Storage Technologies Roadmap Hydrogen Delivery Technical Team Roadmap June 2013 #12;This). The Hydrogen Delivery Technical Team is one of 12 U.S. DRIVE technical teams ("tech teams") whose mission and clean advanced lightduty vehicles, as well as related energy infrastructure. For more information about

  16. Use of sulfide-containing liquors for removing mercury from flue gases

    DOE Patents [OSTI]

    Nolan, Paul S. (North Canton, OH); Downs, William (Alliance, OH); Bailey, Ralph T. (Uniontown, OH); Vecci, Stanley J. (Alliance, OH)

    2003-01-01T23:59:59.000Z

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  17. Use of sulfide-containing liquors for removing mercury from flue gases

    DOE Patents [OSTI]

    Nolan, Paul S.; Downs, William; Bailey, Ralph T.; Vecci, Stanley J.

    2006-05-02T23:59:59.000Z

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  18. TESTING OF ACCELERATOR DIPOLES IN PRESSURIZED SUPERFLUID HELIUM

    E-Print Network [OSTI]

    Gilbert, W.S.

    2010-01-01T23:59:59.000Z

    ESD-10: facility. I i_ -i i_ Training in helium II Fig. 6 D-5: facility. Training in helium II .f liIN PRESSURIZED SUPERFLUID HELIUM W.S. G i l b e r t , S. C a

  19. Helium measurements of pore-fluids obtained from SAFOD drillcore

    E-Print Network [OSTI]

    Ali, S.

    2010-01-01T23:59:59.000Z

    the ductile lower crust: Helium isotope trends." ScienceHilton, Izbicki, J.A. (2003). "Helium isotope studies in the2005). "Source and movement of helium in the eastern Morongo

  20. Effects of Helium Phase Separation on the Evolution of Giant Planets

    E-Print Network [OSTI]

    Jonathan J. Fortney; W. B. Hubbard

    2003-12-15T23:59:59.000Z

    We present the first models of Saturn and Jupiter to couple their evolution to both a radiative-atmosphere grid and to high-pressure phase diagrams of hydrogen with helium. The purpose of these models is to quantify the evolutionary effects of helium phase separation in Saturn's deep interior. We find that prior calculated phase diagrams in which Saturn's interior reaches a region of predicted helium immiscibility do not allow enough energy release to prolong Saturn's cooling to its known age and effective temperature. We explore modifications to published phase diagrams that would lead to greater energy release, and find a modified H-He phase diagram that is physically reasonable, leads to the correct extension of Saturn's cooling, and predicts an atmospheric helium mass fraction Y_atmos in agreement with recent estimates. We then expand our inhomogeneous evolutionary models to show that hypothetical extrasolar giant planets in the 0.15 to 3.0 Jupiter mass range may have T_effs 10-15 K greater than one would predict with models that do not incorporate helium phase separation.

  1. Helium stratification in HD 145792: a new Helium strong star

    E-Print Network [OSTI]

    G. Catanzaro

    2007-11-28T23:59:59.000Z

    In this paper we report on the real nature of the star HD 145792, classified as He weak in {\\it ``The General Catalogue of Ap and Am stars''}. By means of FEROS@ESO1.52m high resolution spectroscopic data, we refined the atmospheric parameters of the star, obtaining: T$_{\\rm eff}$ = 14400 $\\pm$ 400 K, $\\log g$ = 4.06 $\\pm$ 0.08 and $\\xi$ = 0 $^{+0.6}$ km s$^{-1}$. These values resulted always lower than those derived by different authors with pure photometric approaches. Using our values we undertook an abundance analysis with the aim to derive, for the first time, the chemical pattern of the star's atmosphere. For metals a pure LTE synthesis (ATLAS9 and SYNTHE) has been used, while for helium a hybrid approach has been preferred (ATLAS9 and SYNSPEC). The principal result of our study is that HD 145792 belongs to He strong class contrary to the previous classification. Moreover, helium seems to be vertically stratified in the atmosphere, decreasing toward deepest layers. For what that concerns metals abundances, we found the following: overabundance of oxygen, neon, silicon, phosphorus, sulfur and calcium; carbon, nitrogen, magnesium, aluminum, titanium, chromium and nickel are normal, being the discrepancies from the solar values within the experimental errors; iron resulted to be slightly underabundant.

  2. Helium bubble bursting in tungsten

    SciTech Connect (OSTI)

    Sefta, Faiza [University of California, Berkeley, California 94720 (United States); Juslin, Niklas [University of Tennessee, Knoxville, Tennessee 37996 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [University of Tennessee, Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)

    2013-12-28T23:59:59.000Z

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz.

  3. Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets

    E-Print Network [OSTI]

    Bellina, Bruno; Kresin, Vitaly V

    2015-01-01T23:59:59.000Z

    We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N-H...N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.

  4. DESIGN OF EPOXY-FREE SUPERCONDUCTING DIPOLE MAGNETS AND PERFORMANCE IN BOTH HELIUM I AND PRESSURIZED HELIUM II

    E-Print Network [OSTI]

    Taylor, C.

    2010-01-01T23:59:59.000Z

    Exchange I " L ^ v v / / / / > > y^ffHn Helium II cryostatWarren et. al. , "A Pressurized Helium H-Cooled Magnet Testin Pressurized Superfluid Helium", CXS 40 11th International

  5. High-Resolution Differential Ion Mobility Separations Using Helium...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Helium-Rich Gases. High-Resolution Differential Ion Mobility Separations Using Helium-Rich Gases. Abstract: Analyses of complex mixtures and characterization of ions increasingly...

  6. Boron-10 Neutron Detectors for Helium-3 Replacement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Homeland Security & Defense Boron-10 Neutron Detectors for Helium-3 Replacement Boron-10 Neutron Detectors for Helium-3 Replacement As part of the Laboratory's national security...

  7. A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal...

    Open Energy Info (EERE)

    Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Helium Isotope...

  8. Differential Ion Mobility Separations in up to 100% Helium Using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in up to 100% Helium Using Microchips. Differential Ion Mobility Separations in up to 100% Helium Using Microchips. Abstract: The performance of differential IMS (FAIMS) analyzers...

  9. Hydrogen issue in Core Collapse Supernovae

    E-Print Network [OSTI]

    A. Elmhamdi; I. J. Danziger; D. Branch; B. Leibundgut

    2006-11-06T23:59:59.000Z

    We discuss results of analyzing a time series of selected photospheric-optical spectra of core collapse supernovae (CCSNe). This is accomplished by means of the parameterized supernovae synthetic spectrum (SSp) code ``SYNOW''. Special attention is addressed to traces of hydrogen at early phases, especially for the stripped-envelope SNe (i.e. SNe Ib-c). A thin low mass hydrogen layer extending to very high ejection velocities above the helium shell, is found to be the most likely scenario for Type Ib SNe.

  10. Sandia National Laboratories: Hydrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Materials & Components Compatibility Hydrogen Behavior Quantitative Risk Assessment Hydrogen Infrastructure Solar Thermochemical Hydrogen Production Market Transformation...

  11. Micro-PIXE Analysis of Trace Elements in Sulfides

    SciTech Connect (OSTI)

    Hickmott, D.D.; Wetteland, C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stimac, J. [Philippine Geothermal, Makati City, (Philippines); Larocque, A.C.L. [Dept. of Geol. Sci., Univ. Manitoba, Winnipeg, MB, R3T 2N2 (Canada); Brearley, A. [Dept. Earth and Planet. Sci., Univ. New Mexico, Albuquerque, NM 87131 (United States)

    2003-08-26T23:59:59.000Z

    Micro-scale Proton-induced X-ray Emission (PIXE) of trace elements (TE) in sulfides provides insights into geologic processes including magmatic system evolution, ore forming events, and fluid-flow processes. The Los Alamos nuclear microprobe was used to determine TE concentrations and ratios in sulfides from diverse geologic environments including hydrothermal ore deposits, coal seams, and metamorphic rocks. Pyrrhotite (Po) from silicic volcanics contains high Cu and Ni; Po from the Clear Lake volcanic field has higher Mo than does Po from other volcanic fields. Coal pyrites contain high Cu, As, Se, Mo and Pb, and show high As/Se and Mo/Se in marine influenced sulfides from the Lower Kittanning coal, but not in other marine-influenced coals. Sulfides are amenable to micro-PIXE studies because of the difficulties in obtaining the homogeneous standards required for many other TE microanalytical techniques.

  12. Design and fabrication of a tin-sulfide annealing furnace

    E-Print Network [OSTI]

    Lewis, Raymond (Raymond A.)

    2011-01-01T23:59:59.000Z

    A furnace was designed and its heat transfer properties were analyzed for use in annealing thin-film tins-ulfide solar cells. Tin sulfide has been explored as an earth abundant solar cell material, and the furnace was ...

  13. Helium Migration Mechanisms in Polycrystalline Uranium Dioxide

    SciTech Connect (OSTI)

    Martin, Guillaume; Desgardin, Pierre; Sauvage, Thierry; Barthe, Marie-France [CERI, CNRS, 3 A rue de la Ferollerie, ORLEANS, 45071 (France); Garcia, Philippe; Carlot, Gaelle [DEN/DEC/SESC/LLCC, CEA Cadarache, Saint Paul Lez Durance, 13108 (France)

    2007-07-01T23:59:59.000Z

    This study aims at identifying the release mechanisms of helium in uranium dioxide. Two sets of polycrystalline UO{sub 2} sintered samples presenting different microstructures were implanted with {sup 3}He ions at concentrations in the region of 0.1 at.%. Changes in helium concentrations were monitored using two Nuclear Reaction Analysis (NRA) techniques based on the {sup 3}He(d,{alpha}){sup 1}H reaction. {sup 3}He release is measured in-situ during sample annealing at temperatures ranging between 700 deg. C and 1000 deg. C. Accurate helium depth profiles are generated after each annealing stage. Results that provide data for further understanding helium release mechanisms are discussed. It is found that helium diffusion appears to be enhanced above 900 deg. C in the vicinity of grain boundaries possibly as a result of the presence of defects. (authors)

  14. DOE Hydrogen Program Overview

    Broader source: Energy.gov (indexed) [DOE]

    Hydrogen Program A Prospectus for Biological H 2 Production The Hydrogen Economy The hydrogen economy pertains to a world fundamentally different from the one we now know. Hydrogen...

  15. Partition coefficients of chalcophile elements between sulfide and silicate melts and the early crystallization history of sulfide liquid: LA-ICP-MS

    E-Print Network [OSTI]

    the crystallization history of the sulfide liquid is ignored in most studies. Here we present laser ablation

  16. Process for thin film deposition of cadmium sulfide

    DOE Patents [OSTI]

    Muruska, H. Paul (East Windsor, NJ); Sansregret, Joseph L. (Scotch Plains, NJ); Young, Archie R. (Montclair, NJ)

    1982-01-01T23:59:59.000Z

    The present invention teaches a process for depositing layers of cadmium sulfide. The process includes depositing a layer of cadmium oxide by spray pyrolysis of a cadmium salt in an aqueous or organic solvent. The oxide film is then converted into cadmium sulfide by thermal ion exchange of the O.sup.-2 for S.sup.-2 by annealing the oxide layer in gaseous sulfur at elevated temperatures.

  17. Nuclear fusion in muonic deuterium-helium complex

    E-Print Network [OSTI]

    V. M. Bystritsky; M. Filipowicz; V. V. Gerasimov; P. E. Knowles; F. Mulhauser; N. P. Popov; V. A. Stolupin; V. P. Volnykh; J. Wozniak

    2005-06-22T23:59:59.000Z

    Experimental study of the nuclear fusion reaction in charge-asymmetrical d-mu-3He complex is presented. The 14.6 MeV protons were detected by three pairs of Si(dE-E) telescopes placed around the cryogenic target filled with the deuterium + helium-3 gas at 34 K. The 6.85 keV gamma rays emitted during the de-excitation of d-mu-3He complex were detected by a germanium detector. The measurements were performed at two target densities, 0.0585 and 0.169 (relative to liquid hydrogen density) with an atomic concentration of 3He c=0.0469. The values of the effective rate of nuclear fusion in d-mu-3He was obtained for the first time, and the J=0 nuclear fusion rate in d-mu-3He was derived.

  18. Performance of Sulfur Tolerant Reforming Catalysts for Production of Hydrogen from Jet Fuel Simulants

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    (SOFCs) running on jet fuel reformates for its uninhabited aerial vehicle (UAV) and low emission, military missions can be enhanced and made more effective. Reports indicate that an SOFC operating with jet of hydrogen sulfide (H2S), which poisons the anode in the fuel cell stack, leading to low SOFC efficiency

  19. Quasi-free electron energy in near critical point helium

    E-Print Network [OSTI]

    Findley, Gary L.

    Quasi-free electron energy in near critical point helium Yevgeniy Lushtak a,b , Samantha B, Monroe, LA 71209 Abstract We present for the first time the quasi-free electron energy V0() in helium from low density to the density of the triple point liquid (gaseous helium/liquid helium I

  20. Long range forces between atomic impurities in liquid helium

    E-Print Network [OSTI]

    Long range forces between atomic impurities in liquid helium J. Dupont-Roc Laboratoire Kastler in a polarizable medium. We show that atomic impurities in liquid helium may indeed realize repulsive forces embedded in liquid helium, super uid or not. Solid helium have also been used. Successful theoretical

  1. Helium refrigeration considerations for cryomodule design

    SciTech Connect (OSTI)

    Ganni, V.; Knudsen, P. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States)

    2014-01-29T23:59:59.000Z

    Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads.

  2. Methods and systems for the production of hydrogen

    DOE Patents [OSTI]

    Oh, Chang H. (Idaho Falls, ID); Kim, Eung S. (Ammon, ID); Sherman, Steven R. (Augusta, GA)

    2012-03-13T23:59:59.000Z

    Methods and systems are disclosed for the production of hydrogen and the use of high-temperature heat sources in energy conversion. In one embodiment, a primary loop may include a nuclear reactor utilizing a molten salt or helium as a coolant. The nuclear reactor may provide heat energy to a power generation loop for production of electrical energy. For example, a supercritical carbon dioxide fluid may be heated by the nuclear reactor via the molten salt and then expanded in a turbine to drive a generator. An intermediate heat exchange loop may also be thermally coupled with the primary loop and provide heat energy to one or more hydrogen production facilities. A portion of the hydrogen produced by the hydrogen production facility may be diverted to a combustor to elevate the temperature of water being split into hydrogen and oxygen by the hydrogen production facility.

  3. Hydrogen Fueling Systems and Infrastructure

    E-Print Network [OSTI]

    ;Projects Hydrogen Infrastructure Development · Turnkey Commercial Hydrogen Fueling Station · Autothermal

  4. Dimethyl sulfide in the Amazon rain forest

    SciTech Connect (OSTI)

    Jardine, Kolby; Yanez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, Paulo; Guenther, Alex B.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J.; Martin, Scot T.; Andreae, M. O.

    2015-01-01T23:59:59.000Z

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate 44 through the formation of gaseous sulfuric acid, which can yield secondary sulfate 45 aerosols and contribute to new particle formation. While oceans are generally 46 considered the dominant source of DMS, a shortage of ecosystem observations prevents 47 an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified 48 ambient DMS mixing ratios within and above a primary rainforest ecosystem in the 49 central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-50 2014). Elevated but highly variable DMS mixing ratios were observed within the 51 canopy, showing clear evidence of a net ecosystem source to the atmosphere during 52 both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios 53 lasting up to 8 hours (up to 160 ppt) often occurred within the canopy and near the 54 surface during many evenings and nights. Daytime gradients showed mixing ratios (up 55 to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain 56 event. The spatial and temporal distribution of DMS suggests that ambient levels and 57 their potential climatic impacts are dominated by local soil and plant emissions. A soil 58 source was confirmed by measurements of DMS emission fluxes from Amazon soils as 59 a function of temperature and soil moisture. Furthermore, light and temperature 60 dependent DMS emissions were measured from seven tropical tree species. Our study 61 has important implications for understanding terrestrial DMS sources and their role in 62 coupled land-atmosphere climate feedbacks. 63

  5. Hydrogen Production

    Fuel Cell Technologies Publication and Product Library (EERE)

    This 2-page fact sheet provides a brief introduction to hydrogen production technologies. Intended for a non-technical audience, it explains how different resources and processes can be used to produ

  6. DEVELOPMENT AND DEMONSTRATION OF A SUPERCRITICAL HELIUM-COOLED CRYOGENIC VISCOUS COMPRESSOR PROTOTYPE FOR THE ITER VACUUM SYSTEM

    SciTech Connect (OSTI)

    Duckworth, Robert C [ORNL; Baylor, Larry R [ORNL; Meitner, Steven J [ORNL; Combs, Stephen Kirk [ORNL; Rasmussen, David A [ORNL; Edgemon, Timothy D [ORNL; Hechler, Michael P [ORNL; Barbier, Charlotte N [ORNL; Pearce, R.J.H. [ITER Organization, Cadarache, France; Kersevan, R. [ITER Organization, Cadarache, France; Dremel, M. [ITER Organization, Cadarache, France; Boissin, Jean Claude [Consultant

    2012-01-01T23:59:59.000Z

    As part of the vacuum system for the ITER fusion project, a cryogenic viscouscompressor (CVC) is being developed to collect hydrogenic exhaust gases from the toruscryopumps and compress them to a high enough pressure by regeneration for pumping tothe tritium reprocessing facility. Helium impurities that are a byproduct of the fusionreactions pass through the CVC and are pumped by conventional vacuum pumps andexhausted to the atmosphere. Before the development of a full-scale CVC, a representative,small-scale test prototype was designed, fabricated, and tested. With cooling provided bycold helium gas, hydrogen gas was introduced into the central column of the test prototypepump at flow rates between 0.001 g/s and 0.008 g/s. Based on the temperatures and flowrates of the cold helium gas, different percentages of hydrogen gas were frozen to the column surface wall as the hydrogen gas flow rate increased. Results from the measured temperatures and pressures will form a benchmark that will be used to judge future heattransfer enhancements to the prototype CVC and to develop a computational fluid dynamicmodel that will help develop design parameters for the full-scale CVC.

  7. Equation of state of metallic helium

    SciTech Connect (OSTI)

    Shvets, V. T., E-mail: tarval@breezein.net [Odessa State Academy of Refrigeration (Ukraine)

    2013-01-15T23:59:59.000Z

    The effective ion-ion interaction, free energy, pressure, and electric resistance of metallic liquid helium have been calculated in wide density and temperature ranges using perturbation theory in the electron-ion interaction potential. In the case of conduction electrons, the exchange interaction has been taken into account in the random-phase approximation and correlations have been taken into account in the local-field approximation. The solid-sphere model has been used for the nuclear subsystem. The diameter of these spheres is the only parameter of this theory. The diameter and density of the system at which the transition of helium from the singly ionized to doubly ionized state occurs have been estimated by analyzing the pair effective interaction between helium atoms. The case of doubly ionized helium atoms has been considered. Terms up to the third order of perturbation theory have been taken into account in the numerical calculations. The contribution of the third-order term is significant in all cases. The electric resistance and its temperature dependence for metallic helium are characteristic of simple divalent metals in the liquid state. The thermodynamic parameters-temperature and pressure densities-are within the ranges characteristic of the central regions of giant planets. This makes it possible to assume the existence of helium in the metallic state within the solar system.

  8. Measurement of Helium-3/Helium-4 Ratios in Soil Gas at the 618-11 Burial Ground

    SciTech Connect (OSTI)

    Olsen, Khris B.; Dresel, P Evan; Evans, John C.

    2001-10-31T23:59:59.000Z

    Seventy soil gas-sampling points were installed around the perimeter of the 618-11 Burial Ground, approximately 400 feet downgradient of well 699-13-3A, and in four transects downgradient of the burial ground to a maximum distance of 3,100 feet. Soil gas samples were collected and analyzed for helium-3/helium-4 ratios from these 70 points. Helium-3/helium-4 ratios determined from the soil gas sampling points showed significant enrichments, relative to ambient air helium-3 concentrations. The highest concentrations were located along the northern perimeter of the burial ground. Helium-3/helium-4 ratios (normalized to the abundances in ambient air) ranged from 1.0 to 62 around the burial ground. The helium-3/helium-4 ratios from the 4 transect downgradient of the burial ground ranged from 0.988 to 1.68. The helium-3/helium-4 ratios from around the burial ground suggest there is a vadose zone source of tritium along the north side of the burial ground. This vadose zone source is likely the source of tritium in the groundwater. The helium-3/helium-4 ratios also suggest the groundwater plume is traveling east-northeast from the burial ground and the highest groundwater tritium value may be to the north of well 699-13-3A. Finally, there appears to be no immediately upgradient sources of tritium impacting the burial ground since all the upgradient helium-3/helium-4 ratios are approximately 1.0.

  9. The components for a quantum computer based on surface state electrons on liquid helium

    E-Print Network [OSTI]

    Naberhuis, Brian Patrick

    2007-01-01T23:59:59.000Z

    Electrons on Helium . . . . . . . . . . . . . . . . . 1.5.1calculating the stability of electrons on the helium poolNanoscale Posts . . 3.4.2 Helium Pool . . . . Wire Chapter 4

  10. Helium and Carbon Isotope Systematics in Groundwaters along the Southern San Andreas Fault System /

    E-Print Network [OSTI]

    Evans, Tyler John

    2013-01-01T23:59:59.000Z

    P. , & Newton, R. (2010). Low helium flux from the mantlefrom simulations of oceanic helium isotope data. Earth andJ. , & Baur, H. (1995). Helium, neon, and argon systematics

  11. Hydrogen program overview

    SciTech Connect (OSTI)

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

    1997-12-31T23:59:59.000Z

    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.

  12. Measurement of helium-3 and deuterium stopping power ratio for negative muons

    E-Print Network [OSTI]

    V. M. Bystritsky; V. V. Gerasimov; J. Wozniak

    2006-07-07T23:59:59.000Z

    The measurement method and results measuring of the stopping power ratio of helium-3 and deuterium atoms for muons slowed down in the D/$^3$He mixture are presented. Measurements were performed at four values of pure $^3$He gas target densities, $\\phi_{He} = 0.0337, 0.0355, 0.0359, 0.0363$ (normalized to the liquid hydrogen density) and at a density 0.0585 of the D/$^3$He mixture. The experiment was carried out at PSI muon beam $\\mu$E4 with the momentum P$\\mu =34.0$ MeV/c. The measured value of the mean stopping ratio $S_{^3He/D}$ is $1.66\\pm 0.04$. This value can also be interpreted as the value of mean reduced ratio of probabilities for muon capture by helium-3 and deuterium atoms.

  13. The Hype About Hydrogen

    E-Print Network [OSTI]

    Mirza, Umar Karim

    2006-01-01T23:59:59.000Z

    economy based on the hydrogen fuel cell, but this cannot beus to look toward hydrogen. Fuel cell basics, simplifiedthe path to fuel cell commercialization. Hydrogen production

  14. Hydrogen Technologies Group

    SciTech Connect (OSTI)

    Not Available

    2008-03-01T23:59:59.000Z

    The Hydrogen Technologies Group at the National Renewable Energy Laboratory advances the Hydrogen Technologies and Systems Center's mission by researching a variety of hydrogen technologies.

  15. Hydrogen Transition Infrastructure Analysis

    SciTech Connect (OSTI)

    Melendez, M.; Milbrandt, A.

    2005-05-01T23:59:59.000Z

    Presentation for the 2005 U.S. Department of Energy Hydrogen Program review analyzes the hydrogen infrastructure needed to accommodate a transitional hydrogen fuel cell vehicle demand.

  16. Hydrogen Delivery Analysis Models

    Broader source: Energy.gov (indexed) [DOE]

    insert our Research Targets to see the impact List of Delivery Components Compressed Hydrogen Gas Truck (Tube trailer) Compressed Hydrogen Gas Truck Terminal Liquid Hydrogen Truck...

  17. ALTERNATIVE FLOWSHEETS FOR THE SULFUR-IODINE THERMOCHEMICAL HYDROGEN CYCLE

    SciTech Connect (OSTI)

    BROWN,LC; LENTSCH,RD; BESENBRUCH,GE; SCHULTZ,KR; FUNK,JE

    2003-02-01T23:59:59.000Z

    OAK-B135 A hydrogen economy will need significant new sources of hydrogen. Unless large-scale carbon sequestration can be economically implemented, use of hydrogen reduces greenhouse gases only if the hydrogen is produced with non-fossil energy sources. Nuclear energy is one of the limited options available. One of the promising approaches to produce large quantities of hydrogen from nuclear energy efficiently is the Sulfur-Iodine (S-I) thermochemical water-splitting cycle, driven by high temperature heat from a helium Gas-Cooled Reactor. They have completed a study of nuclear-driven thermochemical water-splitting processes. The final task of this study was the development of a flowsheet for a prototype S-I production plant. An important element of this effort was the evaluation of alternative flowsheets and selection of the reference design.

  18. INTRODUCTION The massive sulfide deposits of southern Spain

    E-Print Network [OSTI]

    van Geen, Alexander

    INTRODUCTION The massive sulfide deposits of southern Spain and Portugal were formed about 300 Ma). Spain became a Roman province, and mining of the rich deposits of the Iberian pyrite belt for copper, California 94025 A. Palanques Instituto de Ciencias del Mar, 08039 Barcelona, Spain ABSTRACT A metal

  19. Adsorption of carbonyl sulfide on nickel and tungsten films

    SciTech Connect (OSTI)

    Saleh, J.M.; Nasser, F.A.K.

    1985-07-18T23:59:59.000Z

    The interaction of carbonyl sulfide with evaporated nickel and tungsten films has been investigated in the temperature range 195-450 K using gas pressures ranging from 1 to 13 N m/sup -2/. Rapid but mainly associative chemisorption of COS occurred on both metals at 195 K. Further adsorption of COS on W at temperatures 293-450 K was extremely slow and accompanied by more CO desorption than COS adsorbed. Sulfidation of Ni film by COS occurred at temperatures greater than or equal to 293 K with the liberation of carbon monoxide. The rate of adsorption increased with temperature but was independent of COS pressure. The activation energy (E/sub x/) increased with extent (X) of sulfidation to a limiting value of 97 kJ mol/sup -1/. A linear relationship was obtained from the plot of E/sub x/ against 1/X, suggesting the applicability of Cabrera-Mott theory to the sulfidation of Ni film by COS. 20 references, 2 figures, 1 table.

  20. Helium corona-assisted air discharge

    SciTech Connect (OSTI)

    Jiang Nan; Gao Lei; Ji Ailing; Cao Zexian [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-10-15T23:59:59.000Z

    Operation of atmospheric discharge of electronegative gases including air at low voltages yet without consuming any inert gas will enormously promote the application of non-thermal plasmas. By taking advantage of the low onset voltage for helium corona, air discharge was successfully launched at much reduced voltages with a needle-plate system partly contained in a helium-filled glass bulb--for a needle-plate distance of 12 mm, 1.0 kV suffices. Ultraviolet emission from helium corona facilitates the discharging of air, and the discharge current manifests distinct features such as relatively broad Trichel pulses in both half periods. This design allows safe and economic implementation of atmospheric discharge of electronegative gases, which will find a broad palette of applications in surface modification, plasma medicine and gas treatment, etc.

  1. Surface Segregation in a PdCu Alloy Hydrogen Separation Membrane

    SciTech Connect (OSTI)

    Miller, J.B.; Matranga, C.S.; Gellman, A.J.

    2007-06-01T23:59:59.000Z

    Separation of hydrogen from mixed gas streams is an important step for hydrogen generation technologies, including hydrocarbon reforming and coal/biomass gasification. Dense palladium-based membranes have received significant attention for this application because of palladium’s ability to dissociatively adsorb molecular hydrogen at its surface for subsequent transport of hydrogen atoms through its bulk. Alloying palladium with minor components, like copper, has been shown to improve both the membrane’s structural characteristics and resistance to poisoning of its catalytic surface [1]. Surface segregation—a composition difference between the bulk material and its surface—is common in alloys and can affect important surface processes. Rational design of alloy membranes requires that surface segregation be understood, and possibly controlled. In this work, we examine surface segregation in a polycrystalline Pd70Cu30 hydrogen separation membrane as a function of thermal treatment and adsorption of hydrogen sulfide.

  2. HYDROGEN REGIONAL INFRASTRUCTURE PROGRAM

    E-Print Network [OSTI]

    HYDROGEN REGIONAL INFRASTRUCTURE PROGRAM IN PENNSYLVANIA HYDROGEN REGIONAL INFRASTRUCTURE PROGRAM date ­ November 23, 2004 · Contract end date ­ March 31, 2006 #12;Hydrogen Regional Infrastructure Program in Pennsylvania Hydrogen Regional Infrastructure Program in Pennsylvania · Objectives ­ Capture

  3. Hydrogen Technology Validation

    Fuel Cell Technologies Publication and Product Library (EERE)

    This fact sheet provides a basic introduction to the DOE Hydrogen National Hydrogen Learning Demonstration for non-technical audiences.

  4. Hydrogen Analysis Group

    SciTech Connect (OSTI)

    Not Available

    2008-03-01T23:59:59.000Z

    NREL factsheet that describes the general activites of the Hydrogen Analysis Group within NREL's Hydrogen Technologies and Systems Center.

  5. Shell middle distillate hydrogenation process

    SciTech Connect (OSTI)

    Lucien, J.P. [Companie Rhenane de Raffinage Reichstett, Reichstett Vendenheim (France); Berg, J.P. van den; Hooijdonk, H.M.J.H. van; Thielemans, G.L.B. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Germaine, G. [Shell Recherche SA, Grand-Couronne (France); Gjers, M. [Shell Raffinaderi AB, Gothenburg (Sweden)

    1994-12-31T23:59:59.000Z

    The strive towards cleaner environment has lead to low sulfur specifications for middle distillate fuels. In addition compositional specifications are presently debated. Thus, to meet future emissions standards regarding, specifically, particulates emissions, the motor industry calls for improved automotive gasoil quality. Although automotive gasoil quality affects emissions from diesel engines it is considered less influential than engine design and maintenance. Sulfur, density and cetane number are the fuel properties having the greatest influence on diesel engine emissions although also aromatics and endpoint specifications have been defined in environmentally adopted government initiatives. This paper reviews the options which are available to tackle these new requirements. The high severity single stage concept (using conventional mixed sulfides catalysts) will be discussed in its potential to meet more severe product requirements as well as in terms of its limitations, especially at the point of aromatics saturation and cetaine upgrading. Furthermore, it is shown that the option of severe hydrotreating followed by hydrogenation with conventional noble metal catalysts is preferred if deep aromatics saturation is aimed at. However, this conventional two stage concept has limitations with respect to heaviness and sulfur and nitrogen content of feedstocks. The new Shell Middle Distillate Hydrogenation (SMDH) technology, applying a (semi) two stage approach based on the Shell developed hydrogenation catalyst is presented. The SMDH process will be discussed in its potential to break the limitations of the conventional options. The new catalyst is crucial in this process and allows a highly integrated mode of operation. A number of applications of this novel process will be discussed.

  6. Quantum mechanicallycomplete measurements in electron impact excitation of helium

    E-Print Network [OSTI]

    Quantum mechanicallycomplete measurements in electron impact excitation of helium Andrew G. Mikosza, Nedlands, Perth. 6907, Australia. Abstract. A complete quantum description of the 3! D state of helium, with the Convergent Close Coupling (CCC) calculations. Previous data for helium at 40eV incident electrons

  7. Helium fine structure theory for determination of Krzysztof Pachucki

    E-Print Network [OSTI]

    Pachucki, Krzysztof

    Helium fine structure theory for determination of Krzysztof Pachucki Institute of Theoretical in the calculation of helium fine-structure splitting of the 23 PJ states, based on the quantum electrodynamic theory by comparison with all experimental results for light helium-like ions and with the known large nuclear charge

  8. Helium in confinement: the filling A Neutron Scattering investigation.

    E-Print Network [OSTI]

    Glyde, Henry R.

    Helium in confinement: the filling parameter. A Neutron Scattering investigation. Francesco Albergamo Institut Laue-Langevin, France Helium in confinement: the filling parameter. ­ p.1/13 #12;outline introduction and motivation Helium in confinement: the filling parameter. ­ p.2/13 #12;outline introduction

  9. RESEARCH ARTICLE Particles for tracing turbulent liquid helium

    E-Print Network [OSTI]

    Lathrop, Daniel P.

    RESEARCH ARTICLE Particles for tracing turbulent liquid helium Gregory P. Bewley Ć K. R of local flow velocities in turbulent liquid helium, using tracer particles. We survey and evaluate, we note that cryogenic helium is attractive for experimental studies because its kinematic viscosity

  10. Fluid helium at conditions of giant planetary interiors Lars Stixrude*

    E-Print Network [OSTI]

    Stixrude, Lars

    Fluid helium at conditions of giant planetary interiors Lars Stixrude* and Raymond Jeanloz-abundant chemical element in the universe, helium makes up a large fraction of giant gaseous planets, includ- ing simulations, we find that fluid helium undergoes temperature-induced metallization at high pressures

  11. Classical Helium Atom with Radiation Reaction G. Camelio,1

    E-Print Network [OSTI]

    Carati, Andrea

    Classical Helium Atom with Radiation Reaction G. Camelio,1 A. Carati,2 and L. Galgani2 1) Universit November 2011) We study a classical model of Helium atom in which, in addition to the Coulomb forces be singular with respect to that of Lebesgue. PACS numbers: 05.45.-a, 41.60.-m Keywords: classical Helium atom

  12. RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches Appliquées, L'hélium hypercritique. Abstract. - Conditions of thermal exchange in helium 1 are reviewed. Pool boiling thermosi- phon are given. Use of hypercritical helium. REVUE DE PHYSIQUE APPLIQU�E TOME 6, D�CEMBRE 1971, PAGE Introduction

  13. DETERMINATION DE LA FONCTION DE DISTRIBUTION DE L'ENERGIE ELECTRONIQUE DANS DES COLONNES POSITIVES D'HELIUM ET D'HELIUM-ARGON

    E-Print Network [OSTI]

    Boyer, Edmond

    D'HELIUM ET D'HELIUM-ARGON P. Davy P. Rabache Laboratoire de Physique Electronique, Universite de) have been determined in helium, and helium-argon positiv columns. Between q 06 and q 3 torr, for currents varying between 25 and 400mA, the EDF in helium i s a Maxwell one with a lack of fast electrons

  14. HELIUM COMPRESSOR MONITORING SYSTEM Donna Kubik

    E-Print Network [OSTI]

    HELIUM COMPRESSOR MONITORING SYSTEM Donna Kubik Arecibo Observatory #12;1 CONTENTS 1. Design goals 3 1.1 Features of the compressor monitoring system 4 2. EDAS: The basis of data acquisition 5 2 Compressor #1 Connectors Compressor #2 Connectors Compressor #3 Connectors Compressor #4 Connectors

  15. The Neon DSEL for mining Helium programs

    E-Print Network [OSTI]

    Utrecht, Universiteit

    studies We consider three case studies to illustrate how Neon can be used to data mine the collectionThe Neon DSEL for mining Helium programs Jurriaan Hage Peter van Keeken Department of Information and Computing Sciences, Utrecht University Technical Report UU-CS-2007-023 www.cs.uu.nl ISSN: 0924-3275 #12

  16. Hydrogen sulfide decomposition into hydrogen and sulfur by quinone cycles. First annual report, June 1989-May 1990

    SciTech Connect (OSTI)

    Plummer, M.A.

    1990-06-01T23:59:59.000Z

    The research is evaluating the fundamental mechanisms for recovery of sulfur and H{sub 2} from H{sub 2}S, using mild condition cycles based on oxidation of H{sub 2}S by quinones. During this first year, the research focused on the reaction of H{sub 2}S with tertiary butyl anthraquinone to form tertiary butyl anthrahydroquinone. The progress achieved included extending the quinone conversion from 60-80% to complete conversion, significantly increasing the rate of conversion by varying the solvent, and developing a proposed mechanism for this part of the process.

  17. Safety and Regulatory Structure for CNG, CNG-Hydrogen, Hydrogen...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrogen, Hydrogen Vehicles and Fuels in China Safety and Regulatory Structure for CNG, CNG-Hydrogen, Hydrogen Vehicles and Fuels in China Presentation given by Jinyang Zheng of...

  18. Hydrogen Bonded Arrays: The Power of Multiple Hydrogen Bonds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bonded Arrays: The Power of Multiple Hydrogen Bonds. Hydrogen Bonded Arrays: The Power of Multiple Hydrogen Bonds. Abstract: Hydrogen bond interactions in small covalent model...

  19. Hydrogen permeability and Integrity of hydrogen transfer pipelines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    permeability and Integrity of hydrogen transfer pipelines Hydrogen permeability and Integrity of hydrogen transfer pipelines Presentation by 03-Babu for the DOE Hydrogen Pipeline...

  20. CNG, Hydrogen, CNG-Hydrogen Blends - Critical Fuel Properties...

    Office of Environmental Management (EM)

    CNG, Hydrogen, CNG-Hydrogen Blends - Critical Fuel Properties and Behavior CNG, Hydrogen, CNG-Hydrogen Blends - Critical Fuel Properties and Behavior Presentation given by Jay...

  1. NREL Wind to Hydrogen Project: Renewable Hydrogen Production...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Wind to Hydrogen Project: Renewable Hydrogen Production for Energy Storage & Transportation NREL Wind to Hydrogen Project: Renewable Hydrogen Production for Energy Storage &...

  2. Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery...

    Broader source: Energy.gov (indexed) [DOE]

    Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Targets, barriers and...

  3. Effects of Helium Phase Separation on the Evolution of Extrasolar Giant Planets

    E-Print Network [OSTI]

    Jonathan J. Fortney; W. B. Hubbard

    2004-02-26T23:59:59.000Z

    We build on recent new evolutionary models of Jupiter and Saturn and here extend our calculations to investigate the evolution of extrasolar giant planets of mass 0.15 to 3.0 M_J. Our inhomogeneous thermal history models show that the possible phase separation of helium from liquid metallic hydrogen in the deep interiors of these planets can lead to luminosities ~2 times greater than have been predicted by homogeneous models. For our chosen phase diagram this phase separation will begin to affect the planets' evolution at ~700 Myr for a 0.15 M_J object and ~10 Gyr for a 3.0 M_J object. We show how phase separation affects the luminosity, effective temperature, radii, and atmospheric helium mass fraction as a function of age for planets of various masses, with and without heavy element cores, and with and without the effect of modest stellar irradiation. This phase separation process will likely not affect giant planets within a few AU of their parent star, as these planets will cool to their equilibrium temperatures, determined by stellar heating, before the onset of phase separation. We discuss the detectability of these objects and the likelihood that the energy provided by helium phase separation can change the timescales for formation and settling of ammonia clouds by several Gyr. We discuss how correctly incorporating stellar irradiation into giant planet atmosphere and albedo modeling may lead to a consistent evolutionary history for Jupiter and Saturn.

  4. The effect of hydrogen sulfide on straight-run gasoline during storage

    E-Print Network [OSTI]

    Miller, Alvin Junius

    1934-01-01T23:59:59.000Z

    'Ibtae Of libereeere & SS baca WXNtea sg i moireh in %t;ie fi xe aad miss~ Lo f@oas htrrs ';sea ls'rasgi NA bs~e of tbs ooeploxity' of this yrvblssb coach r?sokxw ~? . . i%i %s grcwgh of thbo yeeroletsn is@ssary? tii is sa4$sb4 l~ secor. ~ iaer:assg is isei~? olfor...O'M eoyabla of grcacbccr aocnmoag ia cba?arfbad by aeoocta". ac aad Oafd? obo aahe O. , f? de4eeCaabfos by Otvavcvtoa oteh ?ttvae sfoaaoa? '. ~ oy toa?roaoar oonafotvtoy? bbto faooax saoho4 aaa 5. . ~ ceo o ta ?cudy? Tha "deoost" oooo yvuvtCa4 a vore...

  5. Polyaniline nanowires-gold nanoparticles hybrid network based chemiresistive hydrogen sulfide sensor

    E-Print Network [OSTI]

    enough concentrations higher than 250 ppm may lead to death.1 Therefore, H2S sensor that is sensitive and rapid in its response is needed. Thick or thin film sensors based on gold and semicon- ductor oxides such as tin oxide, tungsten oxide, etc., have been reported.2,3 Doping with gold enhanced the sensitivity

  6. Electrochemical Membrane Separation (EMS) of Hydrogen Sulfide from Coal Gasification Streams

    SciTech Connect (OSTI)

    Burke, A.A.; Winnick, J.; Liu, M.; Li, S.

    2002-09-20T23:59:59.000Z

    The goal of this work is to prepare an electrolytic cell for scale-up that is capable of removing H2S continuously. The major hurdles that remain are cathode selection and optimizing cell design and operating conditions. Studies have focused upon determining critical cell parameters for process scale-up as well as finding more stable and catalytically active cathode materials.

  7. PERGAMON Carbon 38 (2000) 17571765 High temperature hydrogen sulfide adsorption on activated

    E-Print Network [OSTI]

    Cal, Mark P.

    2000-01-01T23:59:59.000Z

    a New Mexico Tech, Dept. Env. Engr., 801 Leroy Place, Socorro, NM 87801, USA b Malcolm Pirnie, Inc., 104 types of activated carbon sorbents were evaluated for their ability to remove H S from a simulated coal coal gas containing 0.5% H S, 49.5% N , 13% H , 8.5% H O, 21% CO, and 7.5% CO , had a breakthrough time

  8. Simulating Geologic Co-sequestration of Carbon Dioxide and Hydrogen Sulfide in a Basalt Formation

    SciTech Connect (OSTI)

    Bacon, Diana H.; Ramanathan, Ramya; Schaef, Herbert T.; McGrail, B. Peter

    2014-01-15T23:59:59.000Z

    Co-sequestered CO2 with H2S impurities could affect geologic storage, causing changes in pH and oxidation state that affect mineral dissolution and precipitation reactions and the mobility of metals present in the reservoir rocks. We have developed a variable component, non-isothermal simulator, STOMP-COMP (Water, Multiple Components, Salt and Energy), which simulates multiphase flow gas mixtures in deep saline reservoirs, and the resulting reactions with reservoir minerals. We use this simulator to model the co-injection of CO2 and H2S into brecciated basalt flow top. A 1000 metric ton injection of these supercritical fluids, with 99% CO2 and 1% H2S, is sequestered rapidly by solubility and mineral trapping. CO2 is trapped mainly as calcite within a few decades and H2S is trapped as pyrite within several years.

  9. Electrodeposited Cobalt-Sulfide Catalyst for Electrochemical and Photoelectrochemical Hydrogen Generation from Water

    E-Print Network [OSTI]

    the use of strong acids and bases, thus reducing their environmental impact and increasing Generation from Water Yujie Sun,,,, Chong Liu,, David C. Grauer,, Junko Yano, Jeffrey R. Long,*,, Peidong, and long-term aqueous stability, offer promising features for potential use in solar energy applications

  10. The effect of hydrogen sulfide on straight-run gasoline during storage 

    E-Print Network [OSTI]

    Miller, Alvin Junius

    1934-01-01T23:59:59.000Z

    'Ibtae Of libereeere & SS baca WXNtea sg i moireh in %t;ie fi xe aad miss~ Lo f@oas htrrs ';sea ls'rasgi NA bs~e of tbs ooeploxity' of this yrvblssb coach r?sokxw ~? . . i%i %s grcwgh of thbo yeeroletsn is@ssary? tii is sa4$sb4 l~ secor. ~ iaer:assg is isei~? olfor...O'M eoyabla of grcacbccr aocnmoag ia cba?arfbad by aeoocta". ac aad Oafd? obo aahe O. , f? de4eeCaabfos by Otvavcvtoa oteh ?ttvae sfoaaoa? '. ~ oy toa?roaoar oonafotvtoy? bbto faooax saoho4 aaa 5. . ~ ceo o ta ?cudy? Tha "deoost" oooo yvuvtCa4 a vore...

  11. PERGAMON Carbon 38 (2000) 17671774 High temperature hydrogen sulfide adsorption on activated

    E-Print Network [OSTI]

    Cal, Mark P.

    integrated gasification combined cycle (IGCC) power generation process. Part I of this series of papers treatment, Gasification; C. Adsorption 1. Introduction gasification combined cycle (IGCC) power generation

  12. Measurement of Helium-3/Helium-4 Ratios in Soil Gas at the 618-11 Burial Ground

    SciTech Connect (OSTI)

    Olsen, Khris B; Dresel, P Evan; Evans, John C

    2001-10-31T23:59:59.000Z

    Seventy soil gas-sampling points were installed around the perimeter of the 618-11 Burial Ground, approximately 400 feet downgradient of well 699-13-3A, and in four transects downgradient of the burial ground to a maximum distance of 3,100 feet. Soil gas samples were collected and analyzed for helium-3/helium-4 ratios from these 70 points. Helium-3/helium-4 ratios determined from the soil gas sampling points showed significant enrichments, relative to ambient air helium-3 concentrations. The highest concentrations were located along the northern perimeter of the burial ground. Helium-3/helium-4 ratios (normalized to the abundances in ambient air) ranged from 1.0 to 62 around the burial ground. The helium-3/helium-4 ratios from the 4 transect downgradient of the burial ground ranged from 0.988 to 1.68. The helium-3/helium-4 ratios from around the burial ground suggest there is a vadose zone source of tritium along the north side of the burial ground.

  13. The primordial Helium-4 abundance determination: systematic effects

    E-Print Network [OSTI]

    T. X. Thuan; Y. I. Izotov

    2001-12-14T23:59:59.000Z

    By extrapolating to O/H = N/H = 0 the empirical correlations Y-O/H and Y-N/H defined by a relatively large sample of ~ 45 Blue Compact Dwarfs (BCDs), we have obtained a primordial 4Helium mass fraction Yp= 0.2443+/-0.0015 with dY/dZ = 2.4+/-1.0. This result is in excellent agreement with the average Yp= 0.2452+/-0.0015 determined in the two most metal-deficient BCDs known, I Zw 18 (Zsun/50) and SBS 0335-052 (Zsun/41), where the correction for He production is smallest. The quoted error (1sigma) of < 1% is statistical and does not include systematic effects. We examine various systematic effects including collisional excitation of Hydrogen lines, ionization structure and temperature fluctuation effects, and underlying stellar HeI absorption, and conclude that combining all systematic effects, our Yp may be underestimated by ~ 2-4%. Taken at face value, our Yp implies a baryon-to-photon number ratio eta = 4.7x10^-10 and a baryon mass fraction Omega_b h^2_{100} = 0.017+/-0.005 (2sigma), consistent with the values obtained from deuterium and Cosmic Microwave Background measurements. Correcting Yp upward by 2-4% would make the agreement even better.

  14. Hydrogen Delivery Mark Paster

    E-Print Network [OSTI]

    Liquids (e.g. ethanol etc.) ­ Truck: HP Gas & Liquid Hydrogen ­ Regional Pipelines ­ Breakthrough Hydrogen;Delivery Key Challenges · Pipelines ­ Retro-fitting existing NG pipeline for hydrogen ­ Utilizing existing NG pipeline for Hythane with cost effective hydrogen separation technology ­ New hydrogen pipeline

  15. Helium white dwarf in PSR J0751+1807; too cool, in PSR J1012+5307; too hot?

    E-Print Network [OSTI]

    Ene Ergma; Marek J. Sarna; Jelena Gerskevits-Antipova

    2000-10-11T23:59:59.000Z

    We discuss the cooling history of the low-mass, helium core white dwarfs in short orbital period millisecond pulsars PSR J0751+1807 and PSR J1012+5307. The revised cooling age estimated by Alberts et al. agrees with the age estimation for PSR J1012+5307, removing the discrepancy between the spin-down age and the cooling age. However, if we accept this model then the helium white dwarf in the binary pulsar system PSR J0751+1807 must be much hotter than is observed. We propose that this discrepancy may be resolved if, after detachment of the secondary star from its Roche lobe in PSR J0751+1807, the star loses its hydrogen envelope due to pulsar irradiation. When hydrogen burning stops, the white dwarf will cool down much more quickly than in the case of a thick hydrogen envelope with a hydrogen burning shell. We discuss several possibilities to explain different cooling histories of white dwarfs in both systems.

  16. Effect of motions in prominences on the helium resonance lines in the extreme ultraviolet

    E-Print Network [OSTI]

    Nicolas Labrosse; Pierre Gouttebroze; Jean-Claude Vial

    2006-12-08T23:59:59.000Z

    We aim at studying the effect of radial motions on the spectrum emitted by moving prominences in the helium resonance lines and at facilitating the interpretation of observations, in order to improve our understanding of these dynamic structures. We develop our non-local thermodynamic equilibrium radiative transfer code formerly used for the study of quiescent prominences. The new numerical code is now able to solve the statistical equilibrium and radiative transfer equations in the non-static case by using velocity-dependent boundary conditions for the solution of the radiative transfer problem. This first study investigates the effects of different physical conditions (temperature, pressure, geometrical thickness) on the emergent helium radiation. The motion of the prominence plasma induces a Doppler dimming effect on the resonance lines of He I and He II. The velocity effects are particularly important for the He II 304 A line as it is mostly formed by resonant diffusion of incident radiation under prominence conditions. The He I resonance lines at 584 and 537 A also show some sensitivity to the motion of the plasma, all the more when thermal emission is not too important in these lines. We also show that it is necessary to consider partial redistribution in frequency for the scattering of the incident radiation. This set of helium lines offers strong diagnostic possibilities that can be exploited with the SOHO spectrometers and with the EIS spectrometer on board the Hinode satellite. The addition of other helium lines and of lines from other elements (in particular hydrogen) in the diagnostics will further enhance the strength of the method.

  17. The Past and Future of Detached Double White Dwarfs with Helium Donors

    E-Print Network [OSTI]

    Macias, Phillip J; Ramirez-Ruiz, Enrico

    2015-01-01T23:59:59.000Z

    We present a method for modeling the evolution of detached double white dwarf (DWD) binaries hosting helium donors from the end of the common envelope (CE) phase to the onset of Roche Lobe overflow (RLOF). This is achieved by combining detailed stellar evolution calculations of extremely low mass (ELM) helium WDs possessing hydrogen envelopes with the the orbital shrinking of the binary driven by gravitational radiation. We show that the consideration of hydrogen fusion in these systems is crucial, as a significant fraction ($\\approx$50%) of future donors are expected to still be burning when mass transfer commences. We apply our method to two detached eclipsing DWD systems, SDSS J0651+2844 and NLTT-11748, in order to demonstrate the effect that carbon-nitrogen-oxygen (CNO) flashes have on constraining the evolutionary history of such systems. We find that when CNO flashes are absent on the low mass WD ($M_{2}$ < $0.18 M_{\\odot}$), such as in NLTT-11748, we are able to self consistently solve for the donor...

  18. Spectral induced polarization and electrodic potential monitoring of microbially mediated iron sulfide transformations

    SciTech Connect (OSTI)

    Hubbard, Susan; Personna, Y.R.; Ntarlagiannis, D.; Slater, L.; Yee, N.; O'Brien, M.; Hubbard, S.

    2008-02-15T23:59:59.000Z

    Stimulated sulfate-reduction is a bioremediation technique utilized for the sequestration of heavy metals in the subsurface.We performed laboratory column experiments to investigate the geoelectrical response of iron sulfide transformations by Desulfo vibriovulgaris. Two geoelectrical methods, (1) spectral induced polarization (SIP), and (2) electrodic potential measurements, were investigated. Aqueous geochemistry (sulfate, lactate, sulfide, and acetate), observations of precipitates (identified from electron microscopy as iron sulfide), and electrodic potentials on bisulfide ion (HS) sensitive silver-silver chloride (Ag-AgCl) electrodes (630 mV) were diagnostic of induced transitions between an aerobic iron sulfide forming conditions and aerobic conditions promoting iron sulfide dissolution. The SIP data showed 10m rad anomalies during iron sulfide mineralization accompanying microbial activity under an anaerobic transition. These anomalies disappeared during iron sulfide dissolution under the subsequent aerobic transition. SIP model parameters based on a Cole-Cole relaxation model of the polarization at the mineral-fluid interface were converted to (1) estimated biomineral surface area to pore volume (Sp), and (2) an equivalent polarizable sphere diameter (d) controlling the relaxation time. The temporal variation in these model parameters is consistent with filling and emptying of pores by iron sulfide biofilms, as the system transitions between anaerobic (pore filling) and aerobic (pore emptying) conditions. The results suggest that combined SIP and electrodic potential measurements might be used to monitor spatiotemporal variability in microbial iron sulfide transformations in the field.

  19. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, D.P.

    1984-06-05T23:59:59.000Z

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  20. Closed-loop pulsed helium ionization detector

    DOE Patents [OSTI]

    Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

    1987-01-01T23:59:59.000Z

    A helium ionization detector for gas chromatography is operated in a constant current, pulse-modulated mode by configuring the detector, electrometer and a high voltage pulser in a closed-loop control system. The detector current is maintained at a fixed level by varying the frequency of fixed-width, high-voltage bias pulses applied to the detector. An output signal proportional to the pulse frequency is produced which is indicative of the charge collected for a detected species.

  1. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, Donald P. (Southold, NY)

    1985-01-01T23:59:59.000Z

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  2. The helium fine-structure controversy

    E-Print Network [OSTI]

    Ingvar Lindgren

    2008-10-05T23:59:59.000Z

    There is presently disagreement between theory and experiment as well as between different theoretical calculations concerning the fine-structure splitting of the lowest P state of the neutral helium atom. We believe that we have found a minor error in the formulas used by Drake et al. (Can. J. Phys. 80, 1195 (2002)) in their calculations, and we may have an explanation how the error has occurred. To what extent this might resolve (part of) the discrepancy is not known at present.

  3. Hydrogen Fuel Cell Vehicles

    E-Print Network [OSTI]

    Delucchi, Mark

    1992-01-01T23:59:59.000Z

    Hydrogen Fuel Cell Vehicles UCD-ITS-RR-92-14 September bycost than both. Solar-hydrogen fuel- cell vehicles would becost than both. Solar-hydrogen fuel- cell vehicles would be

  4. HYDROGEN IN GERMANIUM

    E-Print Network [OSTI]

    Haller, E.E.

    2011-01-01T23:59:59.000Z

    •^f-1? c^4--^ LBL-7996 HYDROGEN IN GERMANIUM E. E. HallerW-7405-ENG-48 LBL-7996 HYDROGEN IN GERMANIUM* E. E. Haller48. LBL-7996 Abstract Hydrogen is shown to form molecular

  5. President's Hydrogen Fuel Initiative

    Broader source: Energy.gov (indexed) [DOE]

    Hydrogen Fuel Initiative Workshop on Manufacturing R&D for the Hydrogen Economy Washington, DC July 13, 2005 JoAnn Milliken DOE Hydrogen Program Planning U.S. Energy Dependence is...

  6. Influences of Water Vapor on Cr(VI) Reduction by Gaseous Hydrogen

    E-Print Network [OSTI]

    Deng, Baolin

    Columbia, Columbia, Missouri 65211 In Situ Gaseous Reduction (ISGR) using hydrogen sulfide (H2S) is a technology the contaminants, H2S, and various soil components. In this study, Cr(VI) reduction by gaseous H2S was examined under various relative humidities (0-96.7%), concentrations of Cr(VI) (127-475 µg/g of solid), and H2S

  7. Development of charcoal sorbents for helium cryopumping

    SciTech Connect (OSTI)

    Sedgley, D.W.; Tobin, A.G.

    1985-09-30T23:59:59.000Z

    Improved methods for cryopumping helium were developed for application to fusion reactors where high helium generation rates are expected. This study period evaluated charcoal particle size, bonding agent type and thickness, and substrate thickness. The optimum combination of charcoal, bond, and substrate was used to form a scaled-up panel for evaluation in the Tritium Systems Test Assembly (TSTA) at Los Alamos. The optimum combination is a 12 x 30 mesh coconut charcoal attached to a 0.48 cm thick copper substrate by a 0.015 cm thick silver phosphorus copper braze. A copper cement bond for attaching charcoal to a substrate was identified and tested. Helium pumping performance of this combination was comparable to that of the charcoal braze system. Environmental tests showed the charcoal's susceptibility to vacuum chamber contamination. Performance degradation followed exposure of ambient temperature charcoal to a vacuum for prolonged periods. Maintaining a liquid nitrogen-cooled shield between the charcoal and the source of contamination prevented this degradation. A combination of bake-out and LN shielding effected recovery of degraded performance.

  8. Measurement of Hydrogen Balmer Line Broadening and Thermal Power Balances of Noble Gas-Hydrogen Discharge Plasmas

    E-Print Network [OSTI]

    talyst atoms or ions which ionize at integer multiples of the potential energy of atomic hydrogen (St, He + , or Ar + ) caused an increase in power; whereas, no excess power was observed in the case of krypton which does not provide a reaction with a net enthalpy of a multiple of the potential energy of atomic hydrogen under these conditions. For a power input to the glow discharge of 110 W, the excess output power of mixtures of strontium with argon- hydrogen (95/5%), strontium with hydrogen, strontium with helium-hydrogen (95/5%), and argon-hydrogen (95/5%) was 75, 58, 50, and 28 W, respectively, based a comparison of the temperature rise of the cell with krypton-hydrogen mixture (95/5%) and krypton alone. The input power was varied to find conditions that resulted in the optimal output for the strontium- hydrogen plasma. At 136 W input, the excess power significantly increased to 184 W. These studies provide a useful comparison of catalysts for the optimization of the catal

  9. In situ controlled modification of the helium density in single helium-filled nanobubbles

    SciTech Connect (OSTI)

    David, M.-L., E-mail: marie-laure.david@univ-poitiers.fr; Pailloux, F. [Institut Pprime, UPR 3346 CNRS-Université de Poitiers, SP2MI, 86962 Futuroscope-Chasseneuil cedex (France); Canadian Centre for Electron Microscopy, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Alix, K.; Mauchamp, V.; Pizzagalli, L. [Institut Pprime, UPR 3346 CNRS-Université de Poitiers, SP2MI, 86962 Futuroscope-Chasseneuil cedex (France); Couillard, M.; Botton, G. A. [Canadian Centre for Electron Microscopy, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Department of Materials Science and Engineering, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

    2014-03-28T23:59:59.000Z

    We demonstrate that the helium density and corresponding pressure can be modified in single nano-scale bubbles embedded in semiconductors by using the electron beam of a scanning transmission electron microscope as a multifunctional probe: the measurement probe for imaging and chemical analysis and the irradiation source to modify concomitantly the pressure in a controllable way by fine tuning of the electron beam parameters. The control of the detrapping rate is achieved by varying the experimental conditions. The underlying physical mechanisms are discussed; our experimental observations suggest that the helium detrapping from bubbles could be interpreted in terms of direct ballistic collisions, leading to the ejection of the helium atoms from the bubble.

  10. Sandia Hydrogen Combustion Research

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrogen Combustion Research Sandia Hydrogen Combustion Research Sebastian A. Kaiser (PI) Sandia National Laboratories Christopher M. White University of New Hampshire Sponsor: DoE...

  11. Sandia National Laboratories: Hydrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogen Solar Thermochemical Hydrogen Production On June 13, 2014, in SNL maintains the equipment, experts, and partnerships required to develop technology for solar...

  12. Hydrogen Permeation Barrier Coatings

    SciTech Connect (OSTI)

    Henager, Charles H.

    2008-01-01T23:59:59.000Z

    Gaseous hydrogen, H2, has many physical properties that allow it to move rapidly into and through materials, which causes problems in keeping hydrogen from materials that are sensitive to hydrogen-induced degradation. Hydrogen molecules are the smallest diatomic molecules, with a molecular radius of about 37 x 10-12 m and the hydrogen atom is smaller still. Since it is small and light it is easily transported within materials by diffusion processes. The process of hydrogen entering and transporting through a materials is generally known as permeation and this section reviews the development of hydrogen permeation barriers and barrier coatings for the upcoming hydrogen economy.

  13. Hydrogen Program Overview

    Fuel Cell Technologies Publication and Product Library (EERE)

    This 2-page fact sheet provides a brief introduction to the DOE Hydrogen Program. It describes the program mission and answers the question: “Why Hydrogen?”

  14. Hydrogen | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Sources Hydrogen Hydrogen September 30, 2014 Developed by Sandia National Laboratories and several industry partners, the fuel cell mobile light (H2LT) offers a cleaner, quieter...

  15. Hydrogen | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    for clean energy technology manufacturers. March 28, 2014 Sales Tax Exemption for Hydrogen Generation Facilities In North Dakota, the sale of hydrogen used to power an internal...

  16. MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS Qiyang dependent Helium transport in finite geometries, including the simultaneous transient production of defects of Helium bubbles. I. INTRODUCTION Helium production and helium bubble evolution in neutron

  17. Why Hydrogen? Hydrogen from Diverse Domestic Resources

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Gas Pipelines * Nuclear Energy * Office of Science Extending Collaborations * Other Federal Agencies - DOT, EPA, Others * International Collaborations Hydrogen from Diverse...

  18. Summary of research on hydrogen production from fossil fuels conducted at NETL

    SciTech Connect (OSTI)

    Shamsi, Abolghasem

    2008-03-30T23:59:59.000Z

    In this presentation we will summarize the work performed at NETL on the production of hydrogen via partial oxidation/dry reforming of methane and catalytic decomposition of hydrogen sulfide. We have determined that high pressure resulted in greater carbon formation on the reforming catalysts, lower methane and CO2 conversions, as well as a H2/CO ratio. The results also showed that Rh/alumina catalyst is the most resistant toward carbon deposition both at lower and at higher pressures. We studied the catalytic partial oxidation of methane over Ni-MgO solid solutions supported on metal foams and the results showed that the foam-supported catalysts reach near-equilibrium conversions of methane and H2/CO selectivities. The rates of carbon deposition differ greatly among the catalysts, varying from 0.24 mg C/g cat h for the dipped foams to 7.0 mg C/g cat h for the powder-coated foams, suggesting that the exposed Cr on all of the foam samples may interact with the Ni-MgO catalyst to kinetically limit carbon formation. Effects of sulfur poisoning on reforming catalysts were studies and pulse sulfidation of catalyst appeared to be reversible for some of the catalysts but not for all. Under pulse sulfidation conditions, the 0.5%Rh/alumina and NiMg2Ox-1100şC (solid solution) catalysts were fully regenerated after reduction with hydrogen. Rh catalyst showed the best overall activity, less carbon deposition, both fresh and when it was exposed to pulses of H2S. Sulfidation under steady state conditions significantly reduced catalyst activity. Decomposition of hydrogen sulfide into hydrogen and sulfur was studied over several supported metal oxides and metal oxide catalysts at a temperature range of 650-850°C. H2S conversions and effective activation energies were estimated using Arrhenius plots. The results of these studies will further our understanding of catalytic reactions and may help in developing better and robust catalysts for the production of hydrogen from fossil fuels

  19. An Experimental Study of Cold Helium Dispersion in Air

    E-Print Network [OSTI]

    Chorowski, M; Riddone, G

    2002-01-01T23:59:59.000Z

    The Large Hadron Collider (LHC) presently under construction at CERN, will contain about 100 tons of helium mostly located in the underground tunnel and in caverns. Potential failure modes of the accelerator, which may be followed by helium discharge to the tunnel, have been identified and the corresponding helium flows calculated. To verify the analytical calculations of helium dispersion in the tunnel, a dedicated test set-up has been built. It represents a section of the LHC tunnel at a scale 1:13 and is equipped with a controllable helium relief system enabling the simulation of different scenarios of the LHC cryogenic system failures. Corresponding patterns of cold helium dispersion in air have been observed and analysed with respect to oxygen deficiency hazard. We report on the test set-up and the measurement results, which have been scaled to real LHC conditions.

  20. The helium trimer with soft-core potentials

    E-Print Network [OSTI]

    A. Kievsky; E. Garrido; C. Romero-Redondo; P. Barletta

    2011-01-10T23:59:59.000Z

    The helium trimer is studied using two- and three-body soft-core potentials. Realistic helium-helium potentials present an extremely strong short-range repulsion and support a single, very shallow, bound state. The description of systems with more than two helium atoms is difficult due to the very large cancellation between kinetic and potential energy. We analyze the possibility of describing the three helium system in the ultracold regime using a gaussian representation of a widely used realistic potential, the LM2M2 interaction. However, in order to describe correctly the trimer ground state a three-body force has to be added to the gaussian interaction. With this potential model the two bound states of the trimer and the low energy scattering helium-dimer phase shifts obtained with the LM2M2 potential are well reproduced.

  1. CONDITIONS FOR SUCCESSFUL HELIUM DETONATIONS IN ASTROPHYSICAL ENVIRONMENTS

    SciTech Connect (OSTI)

    Holcomb, Cole; Guillochon, James; De Colle, Fabio; Ramirez-Ruiz, Enrico [TASC, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2013-07-01T23:59:59.000Z

    Several models for Type Ia-like supernova events rely on the production of a self-sustained detonation powered by nuclear reactions. In the absence of hydrogen, the fuel that powers these detonations typically consists of either pure helium (He) or a mixture of carbon and oxygen (C/O). Studies that systematically determine the conditions required to initiate detonations in C/O material exist, but until now no analogous investigation of He matter has been conducted. We perform one-dimensional reactive hydrodynamical simulations at a variety of initial density and temperature combinations and find critical length scales for the initiation of He detonations that range between 1 and 10{sup 10} cm. A simple estimate of the length scales over which the total consumption of fuel will occur for steady-state detonations is provided by the Chapman-Jouguet (CJ) formalism. Our initiation lengths are consistently smaller than the corresponding CJ length scales by a factor of {approx}100, providing opportunities for thermonuclear explosions in a wider range of low-mass white dwarfs (WDs) than previously thought possible. We find that virialized WDs with as little mass as 0.24 M{sub Sun} can be detonated, and that even less massive WDs can be detonated if a sizable fraction of their mass is raised to a higher adiabat. That the initiation length is exceeded by the CJ length implies that certain systems may not reach nuclear statistical equilibrium within the time it takes a detonation to traverse the object. In support of this hypothesis, we demonstrate that incomplete burning will occur in the majority of He WD detonations and that {sup 40}Ca, {sup 44}Ti, or {sup 48}Cr, rather than {sup 56}Ni, is the predominant burning product for many of these events. We anticipate that a measure of the quantity of the intermediate-mass elements and {sup 56}Ni produced in a helium-rich thermonuclear explosion can potentially be used to constrain the nature of the progenitor system.

  2. Sulfide-Driven Arsenic Mobilization from Arsenopyrite and Black Shale Pyrite

    SciTech Connect (OSTI)

    Zhu, W.; Young, L; Yee, N; Serfes, M; Rhine, E; Reinfelder, J

    2008-01-01T23:59:59.000Z

    We examined the hypothesis that sulfide drives arsenic mobilization from pyritic black shale by a sulfide-arsenide exchange and oxidation reaction in which sulfide replaces arsenic in arsenopyrite forming pyrite, and arsenide (As-1) is concurrently oxidized to soluble arsenite (As+3). This hypothesis was tested in a series of sulfide-arsenide exchange experiments with arsenopyrite (FeAsS), homogenized black shale from the Newark Basin (Lockatong formation), and pyrite isolated from Newark Basin black shale incubated under oxic (21% O2), hypoxic (2% O2, 98% N2), and anoxic (5% H2, 95% N2) conditions. The oxidation state of arsenic in Newark Basin black shale pyrite was determined using X-ray absorption-near edge structure spectroscopy (XANES). Incubation results show that sulfide (1 mM initial concentration) increases arsenic mobilization to the dissolved phase from all three solids under oxic and hypoxic, but not anoxic conditions. Indeed under oxic and hypoxic conditions, the presence of sulfide resulted in the mobilization in 48 h of 13-16 times more arsenic from arsenopyrite and 6-11 times more arsenic from isolated black shale pyrite than in sulfide-free controls. XANES results show that arsenic in Newark Basin black shale pyrite has the same oxidation state as that in FeAsS (-1) and thus extend the sulfide-arsenide exchange mechanism of arsenic mobilization to sedimentary rock, black shale pyrite. Biologically active incubations of whole black shale and its resident microorganisms under sulfate reducing conditions resulted in sevenfold higher mobilization of soluble arsenic than sterile controls. Taken together, our results indicate that sulfide-driven arsenic mobilization would be most important under conditions of redox disequilibrium, such as when sulfate-reducing bacteria release sulfide into oxic groundwater, and that microbial sulfide production is expected to enhance arsenic mobilization in sedimentary rock aquifers with major pyrite-bearing, black shale formations.

  3. Design of the Helium Purifier for IHEP-ADS Helium Purification System

    E-Print Network [OSTI]

    Jianqin, Zhang; Zhuo, Zhang; Rui, Ge

    2015-01-01T23:59:59.000Z

    Helium Purification System is an important sub-system in the Accelerator Driven Subcritical System of the Institute of High Energy Physics(IHEP ADS). The purifier is designed to work at the temperature of 77K. The purifier will work in a flow rate of 5g/s at 20MPa in continuous operation of 12 hours. The oil and moisture are removed by coalescing filters and a dryer, while nitrogen and oxygen are condensed by a phase separator and then adsorbed in several activated carbon adsorption cylinders. After purification, the purified helium has an impurity content of less than 5ppm.

  4. Electrochemical hydrogen permeation studies of several mono- and diamines

    SciTech Connect (OSTI)

    Al-Janabi, Y.T.; Lewis, A.L. [Saudi Aramco, Dhahran (Saudi Arabia). Lab. Research and Development Center; Oweimreen, G.A. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Chemistry

    1995-09-01T23:59:59.000Z

    The combined presence of moisture and hydrogen sulfide, known in the oil industry as a sour environment, enhances corrosion reactions at a metal surface as well as promotes the entry of hydrogen atoms, resulting from these reactions, into the metal. Increased entry of hydrogen atoms increases the probability of occurrence of hydrogen-induced cracking. The objective of this study is to evaluate the ability of several organic amines to inhibit the overall process of hydrogen entry and to relate their inhibition abilities to their molecular structures. The diffusion coefficients for the permeation of hydrogen atoms through steel estimated in this study using the time-lag and Laplace methods are of the same order of magnitude as those in the published literature. In several hydrogen permeation curves, a characteristic hump was observed. The authors propose that this hump is due to the trapping of hydrogen at sites other than voids and microvoids. The electrochemical system was also sued to study the effectiveness of diethanolamine (DEA), morpholine (MOR), triethanolamine (TEA), ethylenediamine (EDA), and hexamethylene diamine (HMDA) in inhibiting the entry of hydrogen atoms into steel. The diamines were found to be more effective than the monoamines. A nonlinear relationship was observed between the inhibition effectiveness and the concentration of the amines studied. The inhibiting abilities of the monoamines were similar at the high concentration limit (0.01 M) but followed the trend TEA > MOR > DEA at the low concentration limit (5 {times} 10{sup {minus}5} M). For the diamines the inhibiting abilities were also similar at the high concentration limit (5 {times} 10{sup {minus}3} M) and followed the trend HMDA > EDA at the low concentration limit (5 {times} 10{sup {minus}5} M).

  5. Helium preenrichment in the star-forming regions

    E-Print Network [OSTI]

    Leonid Chuzhoy

    2006-05-15T23:59:59.000Z

    We show that element diffusion can produce large fluctuations in the initial helium abundance of the star-forming clouds. Diffusion time-scale, which in stars is much larger than the Hubble time, can fall below 10^8 years in the neutral gas clouds dominated by collisionless dark matter or with dynamically important radiation or magnetic pressure. Helium diffusion may therefore explain the recent observations of globular clusters, which are inconsistent with initially homogeneous helium distribution.

  6. Mixing, Enhanced Helium and Blue Tails in Globular Clusters

    E-Print Network [OSTI]

    V. Caloi

    2000-12-15T23:59:59.000Z

    We investigate the consequences of an increase in the envelope helium abundance of pre-helium flash red giants in globular clusters. Comparing predictions with the CM diagrams of a few crucial GC, one finds no evidence for a substantial increase in the surface helium content of HB members of these clusters, at least for objects in the RR Lyrae region or close to it. The possibility that the most peculiar giants belong to the asymptotic giant branch is discussed. The consequences of a delay in the helium flash are briefly examined.

  7. Helium isotopes in geothermal systems- Iceland, The Geysers,...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and Steamboat Springs...

  8. ON QUANTIFICATION OF HELIUM EMBRITTLEMENT IN FERRITIC/MARTENSITIC STEELS

    SciTech Connect (OSTI)

    Gelles, David S.

    2000-12-01T23:59:59.000Z

    Helium accumulation due to transmutation has long been considered a potential cause for embrittlement in ferritic/martensitic steels. Three Charpy impact databases involving nickel- and boron-doped alloys are quantified with respect to helium accumulation, and it is shown that all predict a very large effect of helium production on embrittlement. If these predictions are valid, use of Ferritic/Martensitic steels for Fusion first wall applications is highly unlikely. It is therefore necessary to reorient efforts regarding development of these steels for fusion applications to concentrate on the issue of helium embrittlement.

  9. Carbon Dioxide and Helium Emissions from a Reservoir of Magmatic...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Carbon Dioxide and Helium Emissions from a Reservoir of Magmatic Gas Beneath Mammoth...

  10. Mantle Helium And Carbon Isotopes In Separation Creek Geothermal...

    Open Energy Info (EERE)

    Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State...

  11. Chemical Vapor Deposited Zinc Sulfide. SPIE Press Monograph

    SciTech Connect (OSTI)

    McCloy, John S.; Tustison, Randal W.

    2013-04-22T23:59:59.000Z

    Zinc sulfide has shown unequaled utility for infrared windows that require a combination of long-wavelength infrared transparency, mechanical durability, and elevated-temperature performance. This book reviews the physical properties of chemical vapor deposited ZnS and their relationship to the CVD process that produced them. An in-depth look at the material microstructure is included, along with a discussion of the material's optical properties. Finally, because the CVD process itself is central to the development of this material, a brief history is presented.

  12. Improved oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, K.; Baxter, D.J.

    1983-07-26T23:59:59.000Z

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1 to 8 wt % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500 to 1000/sup 0/C.

  13. Oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, Ken (Naperville, IL); Baxter, David J. (Woodridge, IL)

    1984-01-01T23:59:59.000Z

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1-8 wt. % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500.degree.-1000.degree. C.

  14. Synthesis of metal sulfide nanomaterials via thermal decomposition of single-source precursors

    E-Print Network [OSTI]

    Yang, Peidong

    generation lower-cost alternative to traditional silicon based solar cells.1 Towards this end, the formation sulfide materials. Introduction Nanocrystal based solar cells have been demonstrated as a possible next in large-scale solar cell applications.2 One such material candidate is cuprous sulfide (Cu2S), a naturally

  15. Nontoxic and Abundant Copper Zinc Tin Sulfide Nanocrystals for Potential High-Temperature Thermoelectric Energy Harvesting

    E-Print Network [OSTI]

    Chen, Yong P.

    and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS sulfide (CZTS) as a nontoxic and abundant thermoelectric material and characterized its thermoelectric materials, the elements in the composition of CZTS are in extremely high abundancethe natural reserves

  16. Europium and samarium doped calcium sulfide thin films grown by PLD S. Christoulakis a,c

    E-Print Network [OSTI]

    Europium and samarium doped calcium sulfide thin films grown by PLD S. Christoulakis a,c , M Suchea Abstract Europium and samarium doped calcium sulfide thin films (CaS:Eu,Sm) with different thickness were and crystallinity. In this work we present preliminary results related to the deposition of europium and samarium

  17. Adenylate pool and radiological tracer studies of the metabolism of micro-metazoans of the sulfide system

    E-Print Network [OSTI]

    Fox, Catherine Alice

    1985-01-01T23:59:59.000Z

    The sulfide biome is the oxygen poor, sulfide rich ecosystem underlying the oxidized layers of most shallow water sea bottoms (Fenchel g Riedl, 1970). The organisms inhabiting this area of low redox potential are termed the "thiobios" (Boaden g Platt, 1971... habitats of the sulfide system (Fenchel g Riedl, 1970), viz. (1) the low energy surface layer? characterized by the continuous presence of oxygen and the absence of sulfide; (2) the redox potential discontinuity layer or chemocline where the upper...

  18. Gaseous Hydrogen Delivery Breakout - Strategic Directions for...

    Broader source: Energy.gov (indexed) [DOE]

    Gaseous Hydrogen Delivery Breakout - Strategic Directions for Hydrogen Delivery Workshop Gaseous Hydrogen Delivery Breakout - Strategic Directions for Hydrogen Delivery Workshop...

  19. Triple Differential Cross sections and Nuclear Recoil in Two-Photon Double Ionization of Helium

    E-Print Network [OSTI]

    Horner, Daniel A.

    2008-01-01T23:59:59.000Z

    Two-Photon Double Ionization of Helium D. A. Horner, 1 C. W.photon double ionization of helium are calculated using theDouble ionization of the helium atom by two XUV photons in

  20. The Helium Cooling System and Cold Mass Support System for the MICE Coupling Solenoid

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    18, No. 2, LBNL-63592 The Helium Cooling System and Coldmass support system and helium cooling system are discussedc and ? = 420 mm III. THE HELIUM COOLING SYSTEM The coupling

  1. Cross sections for short pulse single and double ionization of helium

    E-Print Network [OSTI]

    Palacios, Alicia; Rescigno, Thomas N.; McCurdy, C. William

    2008-01-01T23:59:59.000Z

    ton double ionization of helium at 20 eV above threshold. 1single and double ionization of helium A. Palacios, 1 T. N.double ionization of helium. In particular it is shown how

  2. The Helium Cooling System and Cold Mass Support System for the MICE Coupling Solenoid

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    LBNL-63592 The Helium Cooling System and Cold Mass Supportsystem and helium cooling system are discussed in detail.420 mm III. THE HELIUM COOLING SYSTEM The coupling magnet is

  3. NATIONAL HYDROGEN ENERGY ROADMAP

    E-Print Network [OSTI]

    NATIONAL HYDROGEN ENERGY ROADMAP NATIONAL HYDROGEN ENERGY ROADMAP . . Toward a More Secure and Cleaner Energy Future for America Based on the results of the National Hydrogen Energy Roadmap Workshop to make it a reality. This Roadmap provides a framework that can make a hydrogen economy a reality

  4. Safetygram #9- Liquid Hydrogen

    Broader source: Energy.gov [DOE]

    Hydrogen is colorless as a liquid. Its vapors are colorless, odorless, tasteless, and highly flammable.

  5. Polarized Helium to Image the Lung

    E-Print Network [OSTI]

    Leduc, M; Leduc, Mich\\`{e}le; Nacher, Pierre-Jean

    2006-01-01T23:59:59.000Z

    The main findings of the european PHIL project (Polarised Helium to Image the Lung) are reported. State of the art optical pumping techniques for polarising ^3He gas are described. MRI methodological improvements allow dynamical ventilation images with a good resolution, ultimately limited by gas diffusion. Diffusion imaging appears as a robust method of lung diagnosis. A discussion of the potential advantage of low field MRI is presented. Selected PHIL results for emphysema are given, with the perspectives that this joint work opens up for the future of respiratory medicine.

  6. Production of thorium-229 using helium nuclei

    DOE Patents [OSTI]

    Mirzadeh, Saed (Knoxville, TN) [Knoxville, TN; Garland, Marc Alan (Knoxville, TN) [Knoxville, TN

    2010-12-14T23:59:59.000Z

    A method for producing .sup.229Th includes the steps of providing .sup.226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form .sup.229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1.times.10.sup.13 n s.sup.-1cm.sup.-2. .sup.228Ra can also be bombarded with thermal and/or energetic neutrons to result in a neutron capture reaction to form .sup.229Th. Using .sup.230Th as a target material, .sup.229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

  7. Classical Transitions in Superfluid Helium 3

    E-Print Network [OSTI]

    I-Sheng Yang; S. -H. Henry Tye; Benjamin Shlaer

    2011-10-10T23:59:59.000Z

    We argue that classical transitions can be the key to explaining the long standing puzzle of the fast A-B phase transition observed in superfluid Helium 3 while standard theory expects it to be unobservably slow. Collisions between domain walls are shown to be capable of reaching phases inaccessible through homogenous nucleation on the measured timescales. We demonstrate qualitative agreements with prior observations and provide a definite, distinctive prediction that could be verified through future experiments or, perhaps, a specific analysis of existing data.

  8. Lamb shift in muonic helium ion

    E-Print Network [OSTI]

    A. P. Martynenko

    2014-07-09T23:59:59.000Z

    The Lamb shift (2P_{1/2}-2S_{1/2}) in the muonic helium ion (mu ^4_2He)^+ is calculated with the account of contributions of orders alpha^3, alpha^4, alpha^5 and alpha^6. Special attention is given to corrections of the electron vacuum polarization, the nuclear structure and recoil effects. The obtained numerical value of the Lamb shift 1379.028 meV can be considered as a reliable estimate for the comparison with experimental data.

  9. Kosterlitz-Thouless Transition in Helium Films

    E-Print Network [OSTI]

    Agnolet, Glenn; MCQUEENEY, DF; REPPY, JD.

    1989-01-01T23:59:59.000Z

    and the Materials Science Center, Cornell University, Ithaca, Xetv York 14853 (Received 4 November 1988) The superAuid response of helium Alms with transition temperatures ranging from 70 mK to 0.5 K has been studied using a torsional oscillator technique. A...-Thouless theory. Comparisons with the dynamic theory reveal nonuniversal behavior as a function of coverage. INTRODUCTION The superAuid phase transition in thin He films on planar surfaces is generally acknowledged to be a realiza- tion of a Kosterlitz...

  10. Study of Impurity-Helium Condensates Formed by Multishell Nanoclusters

    E-Print Network [OSTI]

    Mao, Shun

    2014-12-17T23:59:59.000Z

    Impurity-helium condensates (IHCs) are porous gel-like materials created by injecting a mixed beam of helium gas and an impurity gas into super fluid 4He. Van der Waals forces lead to the formation of clusters of impurities each surrounded by a thin...

  11. Helium nanobubble release from Pd surface: An atomic simulation

    SciTech Connect (OSTI)

    Wang, Liang; Hu, Wangyu; Deng, Huiqiu; Xiao, Shifang; Yang, Jianyu; Gao, Fei; Heinisch, Howard L.; Hu, Shilin

    2011-02-14T23:59:59.000Z

    Molecular dynamic simulations of helium atoms escaping from a helium-filled nano-bubble near the surface of crystalline palladium reveal unexpected behavior. Significant deformation and cracking near the helium bubble occur initially, and then a channel forms between the bubble and the surface, providing a pathway for helium atoms to propagate towards the surface. The helium atoms erupt from the bubble in an instantaneous and volcano-like process, which leads to surface deformation consisting of cavity formation on the surface, along with modification and atomic rearrangement at the periphery of the cavity. The present simulation results show that, near the palladium surface, there is a helium-bubble-free zone, or denuded zone, with a typical thickness of about 3.0 nm. Combined with experimental measurements and continuum-scale evolutionary model predictions, the present atomic simulations demonstrate that the thickness of the denuded zone, which contains a low concentration of helium atoms, is somewhat larger than the diameter of the helium bubbles in the metal tritide. Furthermore, a relationship between the tensile strength and thickness of metal film is also determined.

  12. Diss. ETH Nr. 10714 Helium und Tritium als Tracer fr

    E-Print Network [OSTI]

    Aeschbach-Hertig, Werner

    Diss. ETH Nr. 10714 Helium und Tritium als Tracer für physikalische Prozesse in Seen ABHANDLUNG zur Zürich 1994 #12;Kurzfassung ix Kurzfassung Der radioaktive Zerfall von 3H (Tritium) zu 3He mit einer Fluide aus dem Erdinnern. Helium und Tritium werden massenspektrometrisch analysiert. Im Rahmen dieser Ar

  13. Heterogeneous cavitation in liquid helium 4 near a glass plate

    E-Print Network [OSTI]

    Caupin, Frédéric

    Heterogeneous cavitation in liquid helium 4 near a glass plate X. Chavanne, S. Balibar and F wave to study cavitation, i.e. the nucleation of bubbles, in liquid helium 4 near a clean glass plate and threshold pressures in the range 0 to -3 bar, significantly less negative than for homogeneous cavitation

  14. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, Vladimir (Skokie, IL)

    1986-01-01T23:59:59.000Z

    This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

  15. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, V.

    1984-06-13T23:59:59.000Z

    This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

  16. Hydrogen Permeability and Integrity of Hydrogen Delivery Pipelines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Permeability and Integrity of Hydrogen Delivery Pipelines Hydrogen Permeability and Integrity of Hydrogen Delivery Pipelines Project Objectives: To gain basic understanding of...

  17. Hydrogen Delivery Technologies and Systems- Pipeline Transmission of Hydrogen

    Broader source: Energy.gov [DOE]

    Hydrogen Delivery Technologies and Systems - Pipeline Transmission of Hydrogen. Design and operations standards and materials for hydrogen and natural gas pipelines.

  18. Hydrogen Fuel Cell Bus Evaluation: Report for the 2001 Hydrogen...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Bus Evaluation: Report for the 2001 Hydrogen Program Review Hydrogen Fuel Cell Bus Evaluation: Report for the 2001 Hydrogen Program Review This paper, presented at the 2001 DOE...

  19. DOE Hydrogen and Fuel Cells Program Record 5037: Hydrogen Storage...

    Broader source: Energy.gov (indexed) [DOE]

    5037: Hydrogen Storage Materials - 2004 vs. 2006 DOE Hydrogen and Fuel Cells Program Record 5037: Hydrogen Storage Materials - 2004 vs. 2006 This program record from the Department...

  20. Hydrogen Supply: Cost Estimate for Hydrogen Pathways-Scoping...

    Broader source: Energy.gov (indexed) [DOE]

    Supply: Cost Estimate for Hydrogen Pathways-Scoping Analysis. January 22, 2002-July 22, 2002 Hydrogen Supply: Cost Estimate for Hydrogen Pathways-Scoping Analysis. January 22,...

  1. Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect (OSTI)

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-08-01T23:59:59.000Z

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540°C and 900°C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating-current, AC, to direct-current, DC, conversion efficiency is 96%. The overall system thermal-to-hydrogen production efficiency (based on the lower heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%.

  2. Hydrogen energy systems studies

    SciTech Connect (OSTI)

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

    1996-10-01T23:59:59.000Z

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

  3. The Bumpy Road to Hydrogen

    E-Print Network [OSTI]

    Sperling, Dan; Ogden, Joan M

    2006-01-01T23:59:59.000Z

    will trump hydrogen and fuel cell vehicles. Advocates ofbenefits sooner than hydrogen and fuel cells ever could.emissions from a hydrogen fuel cell vehicle will be about

  4. Liquid Hydrogen Absorber for MICE

    E-Print Network [OSTI]

    Ishimoto, S.

    2010-01-01T23:59:59.000Z

    REFERENCES Figure 5: Liquid hydrogen absorber and test6: Cooling time of liquid hydrogen absorber. Eight CernoxLIQUID HYDROGEN ABSORBER FOR MICE S. Ishimoto, S. Suzuki, M.

  5. Hydrogen Bus Technology Validation Program

    E-Print Network [OSTI]

    Burke, Andy; McCaffrey, Zach; Miller, Marshall; Collier, Kirk; Mulligan, Neal

    2005-01-01T23:59:59.000Z

    and evaluate hydrogen enriched natural gas (HCNG) enginewas to demonstrate that hydrogen enriched natural gas (HCNG)characteristics of hydrogen enriched natural gas combustion,

  6. Hydrogen in semiconductors and insulators

    E-Print Network [OSTI]

    Van de Walle, Chris G.

    2007-01-01T23:59:59.000Z

    the electronic level of hydrogen (thick red bar) was notdescribing the behavior of hydrogen atoms as impuritiesenergy of interstitial hydrogen as a function of Fermi level

  7. Photoelectrochemical Hydrogen Production

    SciTech Connect (OSTI)

    Hu, Jian

    2013-12-23T23:59:59.000Z

    The objectives of this project, covering two phases and an additional extension phase, were the development of thin film-based hybrid photovoltaic (PV)/photoelectrochemical (PEC) devices for solar-powered water splitting. The hybrid device, comprising a low-cost photoactive material integrated with amorphous silicon (a-Si:H or a-Si in short)-based solar cells as a driver, should be able to produce hydrogen with a 5% solar-to-hydrogen conversion efficiency (STH) and be durable for at least 500 hours. Three thin film material classes were studied and developed under this program: silicon-based compounds, copper chalcopyrite-based compounds, and metal oxides. With the silicon-based compounds, more specifically the amorphous silicon carbide (a-SiC), we achieved a STH efficiency of 3.7% when the photoelectrode was coupled to an a-Si tandem solar cell, and a STH efficiency of 6.1% when using a crystalline Si PV driver. The hybrid PV/a-SiC device tested under a current bias of -3~4 mA/cm{sup 2}, exhibited a durability of up to ~800 hours in 0.25 M H{sub 2}SO{sub 4} electrolyte. Other than the PV driver, the most critical element affecting the photocurrent (and hence the STH efficiency) of the hybrid PV/a-SiC device was the surface energetics at the a-SiC/electrolyte interface. Without surface modification, the photocurrent of the hybrid PEC device was ~1 mA/cm{sup 2} or lower due to a surface barrier that limits the extraction of photogenerated carriers. We conducted an extensive search for suitable surface modification techniques/materials, of which the deposition of low work function metal nanoparticles was the most successful. Metal nanoparticles of ruthenium (Ru), tungsten (W) or titanium (Ti) led to an anodic shift in the onset potential. We have also been able to develop hybrid devices of various configurations in a monolithic fashion and optimized the current matching via altering the energy bandgap and thickness of each constituent cell. As a result, the short-circuit photocurrent density of the hybrid device (measured in a 2-electrode configuration) increased significantly without assistance of any external bias, i.e. from ?1 mA/cm{sup 2} to ~5 mA/cm{sup 2}. With the copper chalcopyrite compounds, we have achieved a STH efficiency of 3.7% in a coplanar configuration with 3 a-Si solar cells and one CuGaSe{sub 2} photocathode. This material class exhibited good durability at a photocurrent density level of -4 mA/cm{sup 2} (“5% STH” equivalent) at a fixed potential (-0.45 VRHE). A poor band-edge alignment with the hydrogen evolution reaction (HER) potential was identified as the main limitation for high STH efficiency. Three new pathways have been identified to solve this issue. First, PV driver with bandgap lower than that of amorphous silicon were investigated. Crystalline silicon was identified as possible bottom cell. Mechanical stacks made with one Si solar cell and one CuGaSe{sub 2} photocathode were built. A 400 mV anodic shift was observed with the Si cell, leading to photocurrent density of -5 mA/cm{sup 2} at 0VRHE (compared to 0 mA/cm{sup 2} at the same potential without PV driver). We also investigated the use of p-n junctions to shift CuGaSe{sub 2} flatband potential anodically. Reactively sputtered zinc oxy-sulfide thin films was evaluated as n-type buffer and deposited on CuGaSe{sub 2}. Ruthenium nanoparticles were then added as HER catalyst. A 250 mV anodic shift was observed with the p-n junction, leading to photocurrent density at 0VRHE of -1.5 mA/cm{sup 2}. Combining this device with a Si solar cell in a mechanical stack configuration shifted the onset potential further (+400 mV anodically), leading to photocurrent density of -7 mA/cm{sup 2} at 0VRHE. Finally, we developed wide bandgap copper chalcopyrite thin film materials. We demonstrated that Se can be substituted with S using a simple annealing step. Photocurrent densities in the 5-6 mA/cm{sub 2} range were obtained with red 2.0eV CuInGaS{sub 2} photocathodes. With the metal oxide compounds, we have demonstrated that a WO{sub 3}-based hybrid p

  8. Comparative studies of hydrodenitrogenation by mixed metal sulfide catalysts

    E-Print Network [OSTI]

    Luchsinger, Mary Margaret

    1990-01-01T23:59:59.000Z

    . Hydrodenitrogenation of aromatic nitrogen compounds, on the other hand, involve a complex reaction of hydrogenation of the aromatic rings followed by hydrogenolysis. Because quinoline is representative of the nitrogen compounds found in oil shale, coal liquids, tar...

  9. On the helium flash in low-mass Population III Red Giant stars

    E-Print Network [OSTI]

    H. Schlattl; S. Cassisi; M. Salaris; A. Weiss

    2001-05-23T23:59:59.000Z

    We investigate the evolution of initially metal-free, low-mass Red Giant stars through the He core flash at the tip of the Red Giant Branch. The low entropy barrier between the helium- and hydrogen-rich layers enables a penetration of the helium flash driven convective zone into the inner tail of the extinguishing H-burning shell. As a consequence, protons are mixed into high-temperature regions triggering a H-burning runaway. The subsequent dredge-up of matter processed by He and H burning enriches the stellar surface with large amounts of helium, carbon and nitrogen. Extending previous results by Hollowell et al. (1990) and Fujimoto et al. (2000), who claimed that the H-burning runaway is an intrinsic property of extremely metal-poor low-mass stars, we found that its occurrence depends on additional parameters like the initial composition and the treatment of various physical processes. We perform some comparisons between predicted surface chemical abundances and observational measurements for extremely metal-deficient stars. As in previous investigations, our results disclose that although the described scenario provides a good qualitative agreement with observations, considerable discrepancies still remain. They may be due to a more complex evolutionary path of `real' stars, and/or some shortcomings in current evolutionary models. In addition, we analyze the evolutionary properties after the He core flash, during both the central and shell He-burning phases, allowing us to deduce some interesting differences between models whose Red Giant Branch progenitor has experienced the H-flash and canonical models. In particular, the Asymptotic Giant Branch evolution of extremely metal-deficient stars and the occurrence of thermal pulses are strongly affected by the previous RGB evolution.

  10. Effect of Sodium Sulfide on Ni-Containing Carbon Monoxide Dehydrogenases

    SciTech Connect (OSTI)

    Jian Feng; Paul A. Lindahl

    2004-07-28T23:59:59.000Z

    OAK-B135 The structure of the active-site C-cluster in CO dehydrogenase from Carboxythermus hydrogenoformans includes a {mu}{sup 2}-sulfide ion bridged to the Ni and unique Fe, while the same cluster in enzymes from Rhodospirillum rubrum (CODH{sub Rr}) and Moorella thermoacetica (CODH{sub Mt}) lack this ion. This difference was investigated by exploring the effects of sodium sulfide on activity and spectral properties. Sulfide partially inhibited the CO oxidation activity of CODH{sub Rr} and generated a lag prior to steady-state. CODH{sub Mt} was inhibited similarly but without a lag. Adding sulfide to CODH{sub Mt} in the C{sub red1} state caused the g{sub av} = 1.82 EPR signal to decline and new features to appear, including one with g = 1.95, 1.85 and (1.70 or 1.62). Removing sulfide caused the g{sub av} = 1.82 signal to reappear and activity to recover. Sulfide did not affect the g{sub av} = 1.86 signal from the C{sub red2} state. A model was developed in which sulfide binds reversibly to C{sub red1}, inhibiting catalysis. Reducing this adduct causes sulfide to dissociate, C{sub red2} to develop, and activity to recover. Using this model, apparent K{sub I} values are 40 {+-} 10 nM for CODH{sub Rr} and 60 {+-} 30 {micro}M for CODH{sub Mt}. Effects of sulfide are analogous to those of other anions, including the substrate hydroxyl group, suggesting that these ions also bridge the Ni and unique Fe. This proposed arrangement raises the possibility that CO binding labilizes the bridging hydroxyl and increases its nucleophilic tendency towards attacking Ni-bound carbonyl.

  11. Method for determining hydrogen mobility as a function of temperature in superconducting niobium cavities

    DOE Patents [OSTI]

    May, Robert (Virginia Beach, VA)

    2008-03-11T23:59:59.000Z

    A method for determining the mobility of hydrogen as a function of temperature in superconducting niobium cavities comprising: 1) heating a cavity under test to remove free hydrogen; 2) introducing hydrogen-3 gas into the cavity; 3) cooling the cavity to allow absorption of hydrogen-3; and 4) measuring the amount of hydrogen-3 by: a) cooling the cavity to about 4.degree. K while flowing a known and regulated amount of inert carrier gas such as argon or helium into the cavity; b) allowing the cavity to warm at a stable rate from 4.degree. K to room temperature as it leaves the chamber; and c) directing the exit gas to an ion chamber radiation detector.

  12. Hydrogen Delivery Technologies and Pipeline Transmission of Hydrogen

    E-Print Network [OSTI]

    Hydrogen Delivery Technologies and Systems Pipeline Transmission of Hydrogen Strategic Initiatives, and Infrastructure Technologies Program #12;Pipeline Transmission of Hydrogen --- 2 Copyright: Design & Operation development) #12;Pipeline Transmission of Hydrogen --- 3 Copyright: Future H2 Infrastructure Wind Powered

  13. Specified pipe fittings susceptible to sulfide stress cracking

    SciTech Connect (OSTI)

    McIntyre, D.R.; Moore, E.M. Jr. [Saudi Aramco, Dhahran (Saudi Arabia)

    1996-01-01T23:59:59.000Z

    The NACE Standard MR0175 limit of HRC 22 is too high for cold-forged and stress-relieved ASTM A234 WPB pipe fittings. Hardness surveys and sulfide stress cracking test results per ASTM G 39 and NACE TM0177 Method B are presented to support this contention. More stringent inspection and a hardness limit of HB 197 (for cold-forged and stress-relieved fittings only) are recommended. The paper describes a case in which fittings were welded in place in wet sour service flow lines and gas-oil separating plants which were ready to start. The failure of a welded fitting shortly after start-up led to extensive field hardness testing on all fittings from this manufacturer.

  14. Lithium sulfide compositions for battery electrolyte and battery electrode coatings

    DOE Patents [OSTI]

    Liang, Chengdu; Liu, Zengcai; Fu, Wujun; Lin, Zhan; Dudney, Nancy J; Howe, Jane Y; Rondinone, Adam J

    2014-10-28T23:59:59.000Z

    Method of forming lithium-containing electrolytes are provided using wet chemical synthesis. In some examples, the lithium containing electrolytes are composed of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7. The solid electrolyte may be a core shell material. In one embodiment, the core shell material includes a core of lithium sulfide (Li.sub.2S), a first shell of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7, and a second shell including one of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7 and carbon. The lithium containing electrolytes may be incorporated into wet cell batteries or solid state batteries.

  15. Lithium sulfide compositions for battery electrolyte and battery electrode coatings

    SciTech Connect (OSTI)

    Liang, Chengdu; Liu, Zengcai; Fu, Wunjun; Lin, Zhan; Dudney, Nancy J; Howe, Jane Y; Rondinone, Adam J

    2013-12-03T23:59:59.000Z

    Methods of forming lithium-containing electrolytes are provided using wet chemical synthesis. In some examples, the lithium containing electroytes are composed of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7. The solid electrolyte may be a core shell material. In one embodiment, the core shell material includes a core of lithium sulfide (Li.sub.2S), a first shell of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7, and a second shell including one or .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7 and carbon. The lithium containing electrolytes may be incorporated into wet cell batteries or solid state batteries.

  16. Changes in Dimethyl Sulfide Oceanic Distribution due to Climate Change

    SciTech Connect (OSTI)

    Cameron-Smith, P; Elliott, S; Maltrud, M; Erickson, D; Wingenter, O

    2011-02-16T23:59:59.000Z

    Dimethyl sulfide (DMS) is one of the major precursors for aerosols and cloud condensation nuclei in the marine boundary layer over much of the remote ocean. Here they report on coupled climate simulations with a state-of-the-art global ocean biogeochemical model for DMS distribution and fluxes using present-day and future atmospheric CO{sub 2} concentrations. They find changes in zonal averaged DMS flux to the atmosphere of over 150% in the Southern Ocean. This is due to concurrent sea ice changes and ocean ecosystem composition shifts caused by changes in temperature, mixing, nutrient, and light regimes. The largest changes occur in a region already sensitive to climate change, so any resultant local CLAW/Gaia feedback of DMS on clouds, and thus radiative forcing, will be particularly important. A comparison of these results to prior studies shows that increasing model complexity is associted with reduced DMS emissions at the equator and increased emissions at high latitudes.

  17. Gaseous Hydrogen Delivery Breakout- Strategic Directions for Hydrogen Delivery Workshop

    Broader source: Energy.gov [DOE]

    Targets, barriers and research and development priorities for gaseous delivery of hydrogen through hydrogen and natural gas pipelines.

  18. HELIUM EFFECTS ON DISPLACEMENT CASCADE IN TUNGSTEN

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

    2013-09-30T23:59:59.000Z

    Molecular dynamics (MD) simulations were performed to investigate He effects on displacement cascades in W. Helium content, proportion of interstitial and substitutional He and temperature were varied to reveal the various effects. The effect of interstitial He on the number of self-interstitial atoms (SIAs) produced during cascade damage appears to be insignificant. However, interstitial He tends to fill a vacancy (V). Nevertheless, this process is less favorable than SIA-V recombination particularly when excess SIAs are present before a cascade. The efficiency of He filling and SIA-V recombination increases as temperature increases due to increased point defect mobility. Likewise, substitutional He is more susceptible to displacement during a collision cascade than W. This susceptibility increases towards higher temperatures. Consequently, the number of surviving V is governed by the interplay between displaced substitutional He and SIA-V recombination. The temperature dependence of these processes results in a minimum number of V reached at an intermediate temperature.

  19. Searching for dark matter with helium atom

    E-Print Network [OSTI]

    Imre Ferenc Barna

    2006-08-10T23:59:59.000Z

    With the help of the boost operator we can model the interaction between a weakly interacting particle(WIMP) of dark matter(DAMA) and an atomic nuclei. Via this "kick" we calculate the total electronic excitation cross section of the helium atom. The bound spectrum of He is calculated through a diagonalization process with a configuration interaction (CI) wavefunction built up from Slater orbitals. All together 19 singly- and doubly-excited atomic sates were taken with total angular momenta of L=0,1 and 2. Our calculation may give a rude estimation about the magnitude of the total excitation cross section which could be measured in later scintillator experiments. The upper limit of the excitation cross section is $9.7\\cdot 10^{-8}$ barn.

  20. Helium solubility in SON68 nuclear waste glass

    SciTech Connect (OSTI)

    Fares, Toby; Peuget, Sylvain; Bouty, Olivier; Broudic, Veronique; Maugeri, Emilio; Bes, Rene; Jegou, Christophe [CEA, DEN, DTCD SECM LMPA, F-30207 Marcoule, Bagnols Sur Cez, (France); Chamssedine, Fadel; Sauvage, Thierry [CNRS, CEMHTI, F-245071 Orleans, (France); Deschanels, Xavier [LNAR, Marcoule Inst Separat Chem, F-30207 Bagnols Sur Ceze, (France)

    2012-12-15T23:59:59.000Z

    Helium behavior in a sodium borosilicate glass (SON68) dedicated to the immobilization of high-level nuclear waste is examined. Two experimental approaches on nonradioactive glass specimens are implemented: pressurized helium infusion experiments and {sup 3}He ion implantation experiments. The temperature variation of helium solubility in SON68 glass was determined and analyzed with the harmonic oscillator model to determine values of the energy of interaction E(0) at the host sites (about -4000 J/mol), the vibration frequency (about 1.7 x 10{sup 11} s{sup -1}), and the density of solubility sites (2.2 x 10{sup 21} sites cm{sup -3}). The implantation experiments show that a non diffusive transport phenomenon (i.e., athermal diffusion) is involved in the material when the helium concentration exceeds 2.3 x 10{sup 21} He cm{sup -3}, and thus probably as soon as it exceeds the density of solubility sites accessible to helium in the glass. We propose that this transport mechanism could be associated with the relaxation of the stress gradient induced by the implanted helium profile, which is favored by the glass damage. Microstructural characterization by TEM and ESEM of glass specimens implanted with high helium concentrations showed a homogeneous microstructure free of bubbles, pores, or cracking at a scale of 10 nm. (authors)

  1. Gaseous Hydrogen Delivery Breakout

    E-Print Network [OSTI]

    Gaseous Hydrogen Delivery Breakout Strategic Directions for Hydrogen Delivery Workshop May 7 detection Pipeline Safety: odorants, flame visibility Compression: cost, reliability #12;Breakout Session goal of a realistic, multi-energy distribution network model Pipeline Technology Improved field

  2. Hydrogen transport membranes

    DOE Patents [OSTI]

    Mundschau, Michael V.

    2005-05-31T23:59:59.000Z

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  3. Hydrogen Fuel Quality (Presentation)

    SciTech Connect (OSTI)

    Ohi, J.

    2007-05-17T23:59:59.000Z

    Jim Ohi of NREL's presentation on Hydrogen Fuel Quality at the 2007 DOE Hydrogen Program Annual Merit Review and Peer Evaluation on May 15-18, 2007 in Arlington, Virginia.

  4. Primordial Helium And the Cosmic Background Radiation

    E-Print Network [OSTI]

    Gary Steigman

    2010-04-29T23:59:59.000Z

    The products of primordial nucleosynthesis and the cosmic microwave background (CMB) photons are relics from the early evolution of the Universe whose observations probe the standard model of cosmology and provide windows on new physics beyond the standard models of cosmology and of particle physics. In the standard, hot big bang cosmology, long before any stars have formed a significant fraction (~25%) of the baryonic mass in the Universe should be in the form of helium-4 nuclei. Since current 4He observations are restricted to low redshift regions where stellar nucleosynthesis has occurred, observations of high redshift, prestellar 4He would constitute a fundamental test of the hot, big bang cosmology. At recombination, long after big bang nucleosynthesis (BBN) has ended, the temperature anisotropy spectrum imprinted on the CMB depends on the 4He abundance through its connection to the electron density and the effect of the electron density on Silk damping. Since the relic abundance of 4He is relatively insensitive to the universal density of baryons, but is sensitive to a non-standard, early Universe expansion rate, the primordial mass fraction of 4He, Yp, offers a test of the consistency of the standard models of BBN and the CMB and, provides constraints on non-standard physics. Here, the WMAP seven year data (supplemented by other CMB experiments), which lead to an indirect determination of Yp at high redshift, are compared to the BBN predictions and to the independent, direct observations of 4He in low redshift, extragalactic HII regions. At present, given the very large uncertainties in the CMB-determined primordial 4He abundance (as well as for the helium abundances inferred from H II region observations), any differences between the BBN predictions and the CMB observations are small, at a level < 1.5 sigma.

  5. Questions and Issues on Hydrogen Pipeline Transmission of Hydrogen

    E-Print Network [OSTI]

    Questions and Issues on Hydrogen Pipelines Pipeline Transmission of Hydrogen Doe Hydrogen Pipeline Working Group Meeting August 31, 2005 #12;Pipeline Transmission of Hydrogen --- 2 Copyright: Air Liquide Transmission of Hydrogen --- 3 Copyright: #12;Pipeline Transmission of Hydrogen --- 4 Copyright: 3. Special

  6. Webinar: Hydrogen Refueling Protocols

    Broader source: Energy.gov [DOE]

    Video recording and text version of the webinar titled, Hydrogen Refueling Protocols, originally presented on February 22, 2013.

  7. Hydrogen Technologies Safety Guide

    SciTech Connect (OSTI)

    Rivkin, C.; Burgess, R.; Buttner, W.

    2015-01-01T23:59:59.000Z

    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.

  8. Flexible corrugated cryotransferlines, long term experience at JET and the experience with supercritical helium flow conditions

    E-Print Network [OSTI]

    Obert, W

    1996-01-01T23:59:59.000Z

    Flexible corrugated cryotransferlines, long term experience at JET and the experience with supercritical helium flow conditions

  9. Physics 216 Spring 2012 The Variational Computation of the Ground State Energy of Helium

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Physics 216 Spring 2012 The Variational Computation of the Ground State Energy of Helium I. Introduction to the variational computation The Hamiltonian for the two-electron system of the helium atom is state energy of the helium atom. The ground state wave function of the helium atom is of the form: 1 2

  10. Physics 139B Fall 2009 The Variational Computation of the Ground State Energy of Helium

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Physics 139B Fall 2009 The Variational Computation of the Ground State Energy of Helium I. Introduction to the variational computation The Hamiltonian for the two-electron system of the helium atom is state energy of the helium atom. The ground state wave function of the helium atom is of the form: 1 2

  11. Flexible Corrugated Cryotransferlines, Long Term Experience at JET and the Experience with Supercritical Helium Flow Conditions

    E-Print Network [OSTI]

    Flexible Corrugated Cryotransferlines, Long Term Experience at JET and the Experience with Supercritical Helium Flow Conditions

  12. Recombination of He+ in a pulsed helium plasma

    E-Print Network [OSTI]

    Chang, Cheng-shu

    1967-01-01T23:59:59.000Z

    -body Recombinatior Rate Coefficient A for Helium Plasma at Pressure 5 and 6 mm Hg Calculs. ted Values of Electron Temperature Te and. 'Density Ne and the T1"ree-body Recombination Rate Coefficient A for Helium Plasma at Pressure 7 and 8 mm Hg 38 1 ?-. 1 i o.... . ! o. ' T. inc foe Hc '. ior. . 7 i, "1 2 0 i m'" Hg 7. j':lectron Vcm'ocr. . tur= T and Electron Dc!is i. ty a 'h, '" c L:i on o'* Time for Helium Plasma I! . J. r 4! i:lm ii)& ~ ~ ~ ~ ~ ~ 8. Electron Tempo. ature Te and Electron Density N as a...

  13. Sensitive hydrogen leak detector

    DOE Patents [OSTI]

    Myneni, Ganapati Rao (Yorktown, VA)

    1999-01-01T23:59:59.000Z

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  14. Hydrogen Delivery Liquefaction and Compression

    Broader source: Energy.gov [DOE]

    Hydrogen Delivery Liquefaction and Compression - Overview of commercial hydrogen liquefaction and compression and opportunities to improve efficiencies and reduce cost.

  15. Three-dimensional defect characterization : focused ion beam tomography applied to tin sulfide thin films

    E-Print Network [OSTI]

    Youssef, Amanda

    2014-01-01T23:59:59.000Z

    Porosity is postulated to be one of the reasons for the low efficiency of tin sulfide-based devices. This work is a preliminary investigation of the effects of two film growth parameters deposition rate and substrate ...

  16. Doctoral Defense "Investigating the Role of Iron Sulfide on the Long-

    E-Print Network [OSTI]

    Kamat, Vineet R.

    and improper disposal of radioactive waste from extensive extraction and processing activities have caused oxidants re-enter the reducing zone. Previous studies reported that iron sulfide minerals formed during

  17. Arsenate and Arsenite Retention and Release in Oxide and Sulfide Dominated Systems 

    E-Print Network [OSTI]

    Loeppert, Richard H.; Jain, Amita; Raven, Klaus; Wang, Jianlin

    1997-01-01T23:59:59.000Z

    oxidation states (depending on redox potential), and its reactions in soils and sediments are influenced by pH, redox potential, dissolved organic or inorganic components, and sediment colloids (especially Fe sulfides and Fe, Mn, and Al oxides and hydroxides...

  18. Anti-Hydrogen Jonny Martinez

    E-Print Network [OSTI]

    Budker, Dmitry

    Anti-Hydrogen Jonny Martinez University of California, Berkeley #12;OUTLINE WHAT IS ANTI-HYDROGEN? HISTORY IMPORTANCE THEORY HOW TO MAKE ANTI-HYDROGEN OTHER ANTI-MATTER EXPERIMENTS CONCLUSION #12;WHAT IS ANTI-HYDROGEN? Anti-hydrogen is composed of a Positron(anti-electron) and anti-Proton. Anti-Hydrogen

  19. Hydrogen separation process

    DOE Patents [OSTI]

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

    2011-05-24T23:59:59.000Z

    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.

  20. Metal sulfide and rare-earth phosphate nanostructures and methods of making same

    DOE Patents [OSTI]

    Wong, Stanislaus; Zhang, Fen

    2014-05-13T23:59:59.000Z

    The present invention provides a method of producing a crystalline metal sulfide nanostructure. The metal is a transitional metal or a Group IV metal. In the method, a porous membrane is placed between a metal precursor solution and a sulfur precursor solution. The metal cations of the metal precursor solution and sulfur ions of the sulfur precursor solution react, thereby producing a crystalline metal sulfide nanostructure.

  1. The confined hydrogen atom with a moving nucleus

    E-Print Network [OSTI]

    Francisco M. Fernandez

    2010-01-21T23:59:59.000Z

    We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first--order perturbation theory and by a more accurate variational approach. We show that it is greater than the one for the case in which the nucleus is clamped at the center of the box. Present approach resembles the well-known treatment of the helium atom with clamped nucleus.

  2. Effect of sulfidity on the corrosivity of white, green, and black liquors

    SciTech Connect (OSTI)

    Wensley, A.; Champagne, P.

    1999-07-01T23:59:59.000Z

    Corrosion testing was performed in white, green, and black liquors from a kraft mill. The liquors were modified in composition to simulate conditions of high (40%) sulfidity and low (30%) sulfidity, and then heated in laboratory autoclaves to the temperatures of the respective tanks from which the samples were taken. Specimens of carbon and stainless steels were exposed under free corrosion potential conditions, and their corrosion rates determined from weight loss measurements. In white, green, 45% solids black, and flash tank liquors, active corrosion rates for the carbon steels were typically 20 to 75% higher in the higher sulfidity liquors. In 15% solids weak black liquor there was no appreciable difference in corrosion rates, with carbon steels remaining passive in both low and high sulfidity. In 26% solids intermediate black liquor there were large increases in the corrosion rates of carbon steel between low and high sulfidity liquors, resulting from a change from passive to active conditions. Stainless steels UNS S30403, S32304, and S31803 had very low corrosion rates in all the liquors tested, regardless of sulfidity.

  3. NEWS & VIEWS synchrotron or helium-lamp studies. But

    E-Print Network [OSTI]

    Loss, Daniel

    NEWS & VIEWS synchrotron or helium-lamp studies. But the low energy of the laser photons raises that of a conventional metal. The effects of projection have led to detailed quantitative insights into the properties

  4. Ab initio study of helium behavior in titanium tritides

    SciTech Connect (OSTI)

    Liang, J. H.; Dai, Yunya; Yang, Li; Peng, SM; Fan, K. M.; Long, XG; Zhou, X. S.; Zu, Xiaotao; Gao, Fei

    2013-03-01T23:59:59.000Z

    Ab initio calculations based on density functional theory have been performed to investigate the relative stability of titanium tritides and the helium behavior in stable titanium tritides. The results show that the ?-phase TiT1.5 without two tritium along the [100] direction (TiT1.5[100]) is more stable than other possible structures. The stability of titanium tritides decrease with the increased generation of helium in TiT1.5[100]. In addition, helium generated by tritium decay prefers locating at a tetrahedral site, and favorably migrates between two neighbor vacant tetrahedral sites through an intermediate octahedral site in titanium tritides, with a migration energy of 0.23 eV. Furthermore, helium is easily accumulated on a (100) plane in ?-phase TiT1.5[100].

  5. Helium Isotopes in Geothermal and Volcanic Gases of the Western...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Helium Isotopes in Geothermal and Volcanic Gases of the Western United States, II. Long...

  6. The Hall D solenoid helium refrigeration system at JLab

    SciTech Connect (OSTI)

    Laverdure, Nathaniel A. [JLAB; Creel, Jonathan D. [JLAB; Dixon, Kelly d. [JLAB; Ganni, Venkatarao [JLAB; Martin, Floyd D. [JLAB; Norton, Robert O. [JLAB; Radovic, Sasa [JLAB

    2014-01-01T23:59:59.000Z

    Hall D, the new Jefferson Lab experimental facility built for the 12GeV upgrade, features a LASS 1.85 m bore solenoid magnet supported by a 4.5 K helium refrigerator system. This system consists of a CTI 2800 4.5 K refrigerator cold box, three 150 hp screw compressors, helium gas management and storage, and liquid helium and nitrogen storage for stand-alone operation. The magnet interfaces with the cryo refrigeration system through an LN2-shielded distribution box and transfer line system, both designed and fabricated by JLab. The distribution box uses a thermo siphon design to respectively cool four magnet coils and shields with liquid helium and nitrogen. We describe the salient design features of the cryo system and discuss our recent commissioning experience.

  7. Helium Isotopes In Geothermal And Volcanic Gases Of The Western...

    Open Energy Info (EERE)

    Helium Isotopes In Geothermal And Volcanic Gases Of The Western United States, I, Regional Variability And Magmatic Origin Jump to: navigation, search OpenEI Reference LibraryAdd...

  8. Regional And Local Trends In Helium Isotopes, Basin And Range...

    Open Energy Info (EERE)

    And Local Trends In Helium Isotopes, Basin And Range Province, Western North America- Evidence For Deep Permeable Pathways Jump to: navigation, search OpenEI Reference LibraryAdd...

  9. THE POPULATION OF HELIUM-MERGER PROGENITORS: OBSERVATIONAL PREDICTIONS

    SciTech Connect (OSTI)

    Fryer, Chris L. [CCS Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)] [CCS Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Belczynski, Krzysztof; Bulik, Tomasz [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland)] [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Berger, Edo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Thoene, Christina [IAA-CSIC, Glorieta de la Astronomia s/n, E-18008 Granada (Spain)] [IAA-CSIC, Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Ellinger, Carola [Department of Physics, University of Texas at Arlington, 502 Yates Street, Box 19059, Arlington, TX 76019 (United States)] [Department of Physics, University of Texas at Arlington, 502 Yates Street, Box 19059, Arlington, TX 76019 (United States)

    2013-02-20T23:59:59.000Z

    The helium-merger gamma-ray burst (GRB) progenitor is produced by the rapid accretion onto a compact remnant (neutron star or black hole) when it undergoes a common envelope inspiral with its companion's helium core. This merger phase produces a very distinct environment around these outbursts and recent observations suggest that, in some cases, we are detecting the signatures of the past merger in the GRB afterglow. These observations allow us, for the first time, to study the specific features of the helium-merger progenitor. In this paper, we couple population synthesis calculations to our current understanding of GRB engines and common envelope evolution to make observational predictions for the helium-merger GRB population. Many mergers do not produce GRB outbursts and we discuss the implications of these mergers with the broader population of astrophysical transients.

  10. Underground helium travels to the Earth's surface via aquifers...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of South America; it supplies water to more than 15 million people. Scientists found helium pools in this aquifer and is released to the atmosphere when the water reaches the...

  11. Etching of Graphene Devices with a Helium Ion Beam

    E-Print Network [OSTI]

    Baugher, Britton William Herb

    We report on the etching of graphene devices with a helium ion beam, including in situ electrical measurement during lithography. The etching process can be used to nanostructure and electrically isolate different regions ...

  12. Technique to eliminate helium induced weld cracking in stainless steels

    SciTech Connect (OSTI)

    Chin-An Wang; Chin, B.A. [Auburn Univ., AL (United States). Dept. of Materials Engineering; Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)

    1992-12-31T23:59:59.000Z

    Experiments have shown that Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 Mpa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  13. Helium bubble distributions in reactor tank repair specimens

    SciTech Connect (OSTI)

    Tosten, M.H.; Kestin, P.A.

    1992-03-01T23:59:59.000Z

    This report discusses the Reactor Tank Repair (RTR) program was initiated to develop an in-tank repair process capable of repairing stress corrosion cracks within the SRS reactor tank walls, in the event that such a repair is needed. Previous attempts to repair C-reactor tank with a gas tungsten arc (GTA) welding process were unsuccessful due to significant cracking that occurred in the heat-affected-zones adjacent to the repair welds. It was determined that this additional cracking was a result of helium embrittlement caused by the combined effects of helium (existing within the tank walls), the high heat input associated with the GTA process, and weld shrinkage stresses. Based on the results of earlier studies it was suggested that the effects of helium embrittlement could be minimized by using a low heat input GMA process. Metallographic analysis played an important role throughout the investigation of alternative welding methods for the repair of helium-containing materials.

  14. HYDROGEN USAGE AND STORAGE

    E-Print Network [OSTI]

    It is thought that it will be useful to inform society and people who are interested in hydrogen energy. The study below has been prepared due to this aim can be accepted as an article to exchange of information between people working on this subject. This study has been presented to reader to be utilized as a “technical note”. Main Energy sources coal, petroleum and natural gas are the fossil fuels we use today. They are going to be exhausted since careless usage in last decades through out the world, and human being is going to face the lack of energy sources in the near future. On the other hand as the fossil fuels pollute the environment makes the hydrogen important for an alternative energy source against to the fossil fuels. Due to the slow progress in hydrogen’s production, storage and converting into electrical energy experience, extensive usage of Hydrogen can not find chance for applications in wide technological practices. Hydrogen storage stands on an important point in the development of Hydrogen energy Technologies. Hydrogen is volumetrically low energy concentration fuel. Hydrogen energy, to meet the energy quantity necessary for the nowadays technologies and to be accepted economically and physically against fossil fuels, Hydrogen storage technologies have to be developed in this manner. Today the most common method in hydrogen storage may be accepted as the high pressurized composite tanks. Hydrogen is stored as liquid or gaseous phases. Liquid hydrogen phase can be stored by using composite tanks under very high pressure conditions. High technology composite material products which are durable to high pressures, which should not be affected by hydrogen embrittlement and chemical conditions.[1

  15. Helium-3/Helium-4 Ratios in Soil Gas as an Indicator of Tritium Contamination Near the 618-11 Burial Ground, Hanford Site, Washington

    SciTech Connect (OSTI)

    Olsen, Khris B.; Dresel, P. Evan; Evans, J. C.; Poreda, Robert; Shin, Jang Soo

    2003-10-01T23:59:59.000Z

    This paper discusses how Pacific Northwest National Laboratory sampled and analyzed soil gas for helium-3 and helium-4 concentrations from the vicinity of the 618-11 burial ground.

  16. Trace determination of lead by helium-4 activation analysis 

    E-Print Network [OSTI]

    Vargas Bernal, Maria E.

    1984-01-01T23:59:59.000Z

    TRACE DETERMINATION OF LEAD BY HELIUM-4 ACTIVATION ANALYSIS A Thesis by MARIA E. VARGAS BERNAL Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1984 Major Subject: Chemistry TRACE DETERMINATION OF LEAD BY HELIUM-4 ACTIVATION ANALYSIS A Thesis by MARIA E. VARGAS BERNAL Approved as to style and format by: Emile A. Schweikert (Chairman of Committee) Marvin W. Rowe (Member) Gerald A. Sc...

  17. Trace determination of lead by helium-4 activation analysis

    E-Print Network [OSTI]

    Vargas Bernal, Maria E.

    1984-01-01T23:59:59.000Z

    TRACE DETERMINATION OF LEAD BY HELIUM-4 ACTIVATION ANALYSIS A Thesis by MARIA E. VARGAS BERNAL Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1984 Major Subject: Chemistry TRACE DETERMINATION OF LEAD BY HELIUM-4 ACTIVATION ANALYSIS A Thesis by MARIA E. VARGAS BERNAL Approved as to style and format by: Emile A. Schweikert (Chairman of Committee) Marvin W. Rowe (Member) Gerald A. Sc...

  18. Possible stimulation of nuclear alpha-decay by superfluid helium

    E-Print Network [OSTI]

    A. L. Barabanov

    2009-09-03T23:59:59.000Z

    It is suggested that superfluid helium (condensate of 4-He atoms) may stimulate nuclear alpha-decay in a situation when an alpha-emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha-particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha-decay in this case may be sizable enough to be detected.

  19. Process Options for Nominal 2-K Helium Refrigeration System Designs

    SciTech Connect (OSTI)

    Peter Knudsen, Venkatarao Ganni

    2012-07-01T23:59:59.000Z

    Nominal 2-K helium refrigeration systems are frequently used for superconducting radio frequency and magnet string technologies used in accelerators. This paper examines the trade-offs and approximate performance of four basic types of processes used for the refrigeration of these technologies; direct vacuum pumping on a helium bath, direct vacuum pumping using full or partial refrigeration recovery, cold compression, and hybrid compression (i.e., a blend of cold and warm sub-atmospheric compression).

  20. Superfluid helium cryogenic systems for superconducting RF cavities at KEK

    SciTech Connect (OSTI)

    Nakai, H.; Hara, K.; Honma, T.; Hosoyama, K.; Kojima, Y.; Nakanishi, K. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0033 (Japan); Kanekiyo, T. [Hitachi Plant Technologies, Ltd., Toshima-ku, Tokyo 170-8466 (Japan); Morita, S. [Hitachi Plant Mechanics Co., Ltd., Kudamatsu, Yamaguchi 744-0061 (Japan)

    2014-01-29T23:59:59.000Z

    Recent accelerator projects at KEK, such as the Superconducting RF Test Facility (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium, which can generate high gradient acceleration field. Since the operation temperature of these cavities is selected to be 2 K, we have developed two 2 K superfluid helium cryogenic systems for stable operation of superconducting RF cavities for each of STF and cERL. These two 2 K superfluid helium cryogenic systems are identical in principle. Since the operation mode of the cavities is different for STF and cERL, i.e. the pulse mode for STF and the continuous wave mode for cERL, the heat loads from the cavities are quite different. The 2 K superfluid helium cryogenic systems mainly consists of ordinary helium liquefiers/refrigerators, 2 K refrigerator cold boxes, helium gas pumping systems and high-performance transfer lines. The 2 K refrigerators and the high-performance transfer lines are designed by KEK. Some superconducting RF cavity cryomodules have been already connected to the 2 K superfluid helium cryogenic systems for STF and cERL respectively, and cooled down to 2 K successfully.

  1. A RhxSy/C Catalyst for the Hydrogen Oxidation and Hydrogen Evolution Reactions in HBr

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Masud, Jahangir [Univ. of Kansas, Lawrence, KS (United States); Nguyena, Trung V. [Univ. of Kansas, Lawrence, KS (United States); Singh, Nirala [Univ. of California, Santa Barbara, CA (United States); McFarland, Eric [Univ. of California, Santa Barbara, CA (United States); Ikenberry, Myles [Kansas State Univ., Manhattan, KS (United States); Hohn, Keith [Kansas State Univ., Manhattan, KS (United States); Pan, Chun-Jern [National Taiwan University of Science & Technology, Tapei (Taiwan); Hwang, Bing-Joe [National Taiwan University of Science & Technology, Tapei (Taiwan)

    2015-01-01T23:59:59.000Z

    Rhodium sulfide (Rh2S3) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh2S3 at high temperatures (600°C to 850°C) in presence of argon resulted in the transformation of Rh2S3 into Rh3S4, Rh17S15 and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H2SO4 and HBr solutions. The thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (io) of the synthesized RhxSy catalysts in H2-saturated 1M H2SO4 and 1M HBr for HER and HOR were 0.9 mA/cm2 to 1.0 mA/cm2 and 0.8 to 0.9 mA/cm2, respectively. The lower io values obtained in 1M HBr solution compared to in H2SO4 might be due to the adsorption of Br- on the active surface. Stable electrochemical active surface area (ECSA) of RhxSy catalyst was obtained for CV scan limits between 0 V and 0.65 V vs. RHE. Scans with upper voltage limit beyond 0.65 V led to decreased and unreproducible ECSA measurements.

  2. Hydrogen Separation Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect (OSTI)

    Roark, Shane E.; Mackay, Richard; Sammells, Anthony F.

    2001-11-06T23:59:59.000Z

    Eltron Research and team members CoorsTek, McDermott Technology, Sued Chemie, Argonne National Laboratory, and Oak Ridge National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. This project was motivated by the Department of Energy (DOE) National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. The proposed technology addresses the DOE Vision 21 initiative in two ways. First, this process offers a relatively inexpensive solution for pure hydrogen separation that can be easily incorporated into Vision 21 fossil fuel plants. Second, this process could reduce the cost of hydrogen, which is a clean burning fuel under increasing demand as supporting technologies are developed for hydrogen utilization and storage. Additional motivation for this project arises from the potential of this technology for other applications. By appropriately changing the catalysts coupled with the membrane, essentially the same system can be used to facilitate alkane dehydrogenation and coupling, aromatics processing, and hydrogen sulfide decomposition.

  3. Hydrogen Energy Stations: Poly-Production of Electricity, Hydrogen, and Thermal Energy

    E-Print Network [OSTI]

    Lipman, Timothy; Brooks, Cameron

    2006-01-01T23:59:59.000Z

    psi) High-pressure hydrogen compressor Compressed hydrogen2005 High-pressure hydrogen compressor Compressed hydrogenthe hydrogen, a hydrogen compressor, high-pressure tank

  4. Hydrogen Filling Station

    SciTech Connect (OSTI)

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

    2010-02-24T23:59:59.000Z

    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 future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for hydrogen development; accelerate the development of photovoltaic components Project Objective 4:

  5. Ultrafine hydrogen storage powders

    DOE Patents [OSTI]

    Anderson, Iver E. (Ames, IA); Ellis, Timothy W. (Doylestown, PA); Pecharsky, Vitalij K. (Ames, IA); Ting, Jason (Ames, IA); Terpstra, Robert (Ames, IA); Bowman, Robert C. (La Mesa, CA); Witham, Charles K. (Pasadena, CA); Fultz, Brent T. (Pasadena, CA); Bugga, Ratnakumar V. (Arcadia, CA)

    2000-06-13T23:59:59.000Z

    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.

  6. Helium-3/Helium-4 Ratios in Soil Gas as an Indicator of Tritium Contamination Near the 618-11 Burial Ground, Hanford Site, Washington

    SciTech Connect (OSTI)

    Olsen, Khris B.; Dresel, P Evan; Evans, J. C.; Poreda, Robert

    2004-10-09T23:59:59.000Z

    Pacific Northwest National Laboratory sampled and analyzed soil gas for helium-3 and helium-4 concentrations from the vicinity of the 618-11 burial ground. The results of the measurement of helium isotopes in soil gas provided a rapid and cost-effective technique to define the shape and extent of tritium contamination from the 618-11 burial ground.

  7. Classical Helium Atom with Radiation Reaction

    E-Print Network [OSTI]

    G. Camelio; A. Carati; L. Galgani

    2011-11-24T23:59:59.000Z

    We study a classical model of Helium atom in which, in addition to the Coulomb forces, the radiation reaction forces are taken into account. This modification brings in the model a new qualitative feature of a global character. Indeed, as pointed out by Dirac, in any model of classical electrodynamics of point particles involving radiation reaction one has to eliminate, from the a priori conceivable solutions of the problem, those corresponding to the emission of an infinite amount of energy. We show that the Dirac prescription solves a problem of inconsistency plaguing all available models which neglect radiation reaction, namely, the fact that in all such models most initial data lead to a spontaneous breakdown of the atom. A further modification is that the system thus acquires a peculiar form of dissipation. In particular, this makes attractive an invariant manifold of special physical interest, the zero--dipole manifold, that corresponds to motions in which no energy is radiated away (in the dipole approximation). We finally study numerically the invariant measure naturally induced by the time--evolution on such a manifold, and this corresponds to studying the formation process of the atom. Indications are given that such a measure may be singular with respect to that of Lebesgue.

  8. Anti-helium from Dark Matter annihilations

    E-Print Network [OSTI]

    Marco Cirelli; Nicolao Fornengo; Marco Taoso; Andrea Vittino

    2014-10-21T23:59:59.000Z

    Galactic Dark Matter (DM) annihilations can produce cosmic-ray anti-nuclei via the nuclear coalescence of the anti-protons and anti-neutrons originated directly from the annihilation process. Since anti-deuterons have been shown to offer a distinctive DM signal, with potentially good prospects of detection in large portions of the DM-particle parameter space, we explore here the production of heavier anti-nuclei, specifically anti-helium. Even more than for anti-deuterons, the DM-produced anti-He flux can be mostly prominent over the astrophysical anti-He background at low kinetic energies, typically below 3-5 GeV/n. However, the larger number of anti-nucleons involved in the formation process makes the anti-He flux extremely small. We therefore explore, for a few DM benchmark cases, whether the yield is sufficient to allow for anti-He detection in current-generation experiments, such as AMS-02. We account for the uncertainties due to the propagation in the Galaxy and to the uncertain details of the coalescence process, and we consider the constraints already imposed by anti-proton searches. We find that only for very optimistic configurations it might be possible to achieve detection with current generation detectors. We estimate that, in more realistic configurations, an increase in experimental sensitivity at low-kinetic energies of about a factor of 500-1000 would allow to start probing DM through the rare cosmic anti-He production.

  9. Analysis of hydrogen isotope mixtures

    DOE Patents [OSTI]

    Villa-Aleman, Eliel (Aiken, SC)

    1994-01-01T23:59:59.000Z

    An apparatus and method for determining the concentrations of hydrogen isotopes in a sample. Hydrogen in the sample is separated from other elements using a filter selectively permeable to hydrogen. Then the hydrogen is condensed onto a cold finger or cryopump. The cold finger is rotated as pulsed laser energy vaporizes a portion of the condensed hydrogen, forming a packet of molecular hydrogen. The desorbed hydrogen is ionized and admitted into a mass spectrometer for analysis.

  10. Improved cell design for lithium alloy/metal sulfide battery

    DOE Patents [OSTI]

    Kaun, T.D.

    1984-03-30T23:59:59.000Z

    The disclosed lithium alloy/iron sulfide cell design provides loop-like positive and negative sheet metal current collectors electrically insulated from one another by separator means, the positive collector being located outwardly of the negative collector. The collectors are initially secured within an open-ended cell housing, which allows for collector pretesting for electrical shorts prior to adding any electrode materials and/or electrolyte to the cell. Separate chambers are defined outwardly of the positive collector and inwardly of the negative collector open respectively in opposite directions toward the open ends of the cell housing; and positive and negative electrode materials can be extruded into these respective chambers via the opposite open housing ends. The chambers and cell housing ends can then be sealed closed. A cross wall structurally reinforces the cell housing and also thereby defines two cavities, and paired positive and negative collectors are disposed in each cavity and electrically connected in parallel. The cell design provides for a high specific energy output and improved operating life in that any charge-discharge cycle swelling of the positive electrode material will be inwardly against only the positive collector to minimize shorts caused by the collectors shifting relative to one another.

  11. Cell design for lithium alloy/metal sulfide battery

    DOE Patents [OSTI]

    Kaun, Thomas D. (New Lennox, IL)

    1985-01-01T23:59:59.000Z

    The disclosed lithium alloy/iron sulfide cell design provides loop-like positive and negative sheet metal current collectors electrically insulated from one another by separator means, the positive collector being located outwardly of the negative collector. The collectors are initially secured within an open-ended cell housing, which allows for collector pretesting for electrical shorts prior to adding any electrode materials and/or electrolyte to the cell. Separate chambers are defined outwardly of the positive collector and inwardly of the negative collector open respectively in opposite directions toward the open ends of the cell housing; and positive and negative electrode materials can be extruded into these respective chambers via the opposite open housing ends. The chambers and cell housing ends can then be sealed closed. A cross wall structurally reinforces the cell housing and also thereby defines two cavities, and paired positive and negative collectors are disposed in each cavity and electrically connected in parallel. The cell design provides for a high specific energy output and improved operating life in that any charge-discharge cycle swelling of the positive electrode material will be inwardly against only the positive collector to minimize shorts caused by the collectors shifting relative to one another.

  12. High Pressure Hydrogen Materials Compatibility of Piezoelectric...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pressure Hydrogen Materials Compatibility of Piezoelectric Films. High Pressure Hydrogen Materials Compatibility of Piezoelectric Films. Abstract: Abstract: Hydrogen is being...

  13. Sandia National Laboratories: Solar Thermochemical Hydrogen Production

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Materials & Components Compatibility Hydrogen Behavior Quantitative Risk Assessment Hydrogen Infrastructure Solar Thermochemical Hydrogen Production Market Transformation...

  14. Hydrogen Permeation Resistant Coatings

    SciTech Connect (OSTI)

    KORINKO, PAUL; ADAMS, THAD; CREECH, GREGGORY

    2005-06-15T23:59:59.000Z

    As the National Hydrogen Economy continues to develop and evolve the need for structural materials that can resist hydrogen assisted degradation will become critical. To date austenitic stainless steel materials have been shown to be mildly susceptible to hydrogen attack which results in lower mechanical and fracture strengths. As a result, hydrogen permeation barrier coatings may be applied to these ferrous alloys to retard hydrogen ingress. Hydrogen is known to be very mobile in materials of construction. In this study, the permeation resistance of bare stainless steel samples and coated stainless steel samples was tested. The permeation resistance was measured using a modular permeation rig using a pressure rise technique. The coating microstructure and permeation results will be discussed in this document as will some additional testing.

  15. Do Magnetic Fields Prevent Hydrogen from Accreting onto Cool Metal-line White Dwarf Stars?

    E-Print Network [OSTI]

    S. Friedrich; S. Jordan; D. Koester

    2004-10-21T23:59:59.000Z

    It is generally assumed that metals detected in the spectra of a few cool white dwarfs cannot be of primordial origin and must be accreted from the interstellar medium. However, the observed abundances of hydrogen, which should also be accreted from the interstellar medium, are lower than expected from metal accretion. Magnetic fields are thought to be the reason for this discrepancy. We have therefore obtained circular polarization spectra of the helium-rich white dwarfs GD40 and L745-46A, which both show strong metal lines as well as hydrogen. Whereas L745-46A might have a magnetic field of about -6900 G, which is about two times the field strength of 3000G necessary to repell hydrogen at the Alfen radius, only an upper limit for the field strength of GD40 of 4000G (with 99% confidence) can be set which is far off the minimum field strength of 144000G to repell hydrogen.

  16. Helium gas bubble trapped in liquid helium in high magnetic field

    SciTech Connect (OSTI)

    Bai, H., E-mail: bai@magnet.fsu.edu; Hannahs, S. T.; Markiewicz, W. D.; Weijers, H. W. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

    2014-03-31T23:59:59.000Z

    High magnetic field magnets are used widely in the area of the condensed matter physics, material science, chemistry, geochemistry, and biology at the National High Magnetic Field Laboratory. New high field magnets of state-of-the-art are being pursued and developed at the lab, such as the current developing 32?T, 32?mm bore fully superconducting magnet. Liquid Helium (LHe) is used as the coolant for superconducting magnets or samples tested in a high magnetic field. When the magnetic field reaches a relatively high value the boil-off helium gas bubble generated by heat losses in the cryostat can be trapped in the LHe bath in the region where BzdBz/dz is less than negative 2100 T{sup 2}/m, instead of floating up to the top of LHe. Then the magnet or sample in the trapped bubble region may lose efficient cooling. In the development of the 32?T magnet, a prototype Yttrium Barium Copper Oxide coil of 6 double pancakes with an inner diameter of 40?mm and an outer diameter of 140?mm was fabricated and tested in a resistive magnet providing a background field of 15?T. The trapped gas bubble was observed in the tests when the prototype coil was ramped up to 7.5?T at a current of 200?A. This letter reports the test results on the trapped gas bubble and the comparison with the analytical results which shows they are in a good agreement.

  17. Detection of significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas

    SciTech Connect (OSTI)

    Bartnik, A.; Wachulak, P.; Fiedorowicz, H.; Fok, T.; Jarocki, R.; Szczurek, M. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)] [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)

    2013-11-15T23:59:59.000Z

    In this work, spectral investigations of photoionized He plasmas were performed. The photoionized plasmas were created by irradiation of helium stream, with intense pulses from laser-plasma extreme ultraviolet (EUV) source. The EUV source was based on a double-stream Xe/Ne gas-puff target irradiated with 10 ns/10 J Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region below 20 nm, however, spectrally integrated intensity at longer wavelengths was also significant. The EUV radiation was focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulse. The long-wavelength part of the EUV radiation was used for backlighting of the photoionized plasmas to obtain absorption spectra. Both emission and absorption spectra in the EUV range were investigated. Significant differences between absorption spectra acquired for neutral helium and low temperature photoionized plasmas were demonstrated for the first time. Strong increase of intensities and spectral widths of absorption lines, together with a red shift of the K-edge, was shown.

  18. Hydrogen powered bus

    ScienceCinema (OSTI)

    None

    2013-11-22T23:59:59.000Z

    Take a ride on a new type of bus, fueled by hydrogen. These hydrogen taxis are part of a Department of Energy-funded deployment of hydrogen powered vehicles and fueling infrastructure at nine federal facilities across the country to demonstrate this market-ready advanced technology. Produced and leased by Ford Motor Company , they consist of one 12- passenger bus and one nine-passenger bus. More information at: http://go.usa.gov/Tgr

  19. Hydrogen energy systems studies

    SciTech Connect (OSTI)

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

    1995-09-01T23:59:59.000Z

    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.

  20. Energy Balance in the Solar Transition Region. IV. Hydrogen and Helium Mass Flows With Diffusion

    E-Print Network [OSTI]

    J. M. Fontenla; E. H. Avrett; R. Loeser

    2001-09-24T23:59:59.000Z

    In this paper we have extended our previous modeling of energy balance in the chromosphere-corona transition region to cases with particle and mass flows. The cases considered here are quasi-steady, and satisfy the momentum and energy balance equations in the transition region. We include in all equations the flow velocity terms and neglect the partial derivatives with respect to time. We present a complete and physically consistent formulation and method for solving the non-LTE and energy balance equations in these situations, including both particle diffusion and flows of H and He. Our results show quantitatively how mass flows affect the ionization and radiative losses of H and He, thereby affecting the structure and extent of the transition region. Also, our computations show that the H and He line profiles are greatly affected by flows. We find that line shifts are much less important than the changes in line intensity and central reversal due to the effects of flows. In this paper we use fixed conditions at the base of the transition region and in the chromosphere because our intent is to show the physical effects of flows and not to match any particular observations. However, we note that the profiles we compute can explain the range of observed high spectral and spatial resolution Lyman alpha profiles from the quiet Sun. We suggest that dedicated modeling of specific sequences of observations based on physically consistent methods like those presented here will substantially improve our understanding of the energy balance in the chromosphere and corona.

  1. Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals |

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613PortsmouthBartlesvilleAbout » Contact Us Contact Us

  2. Hydrogen Delivery - Basics | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Delivery Hydrogen Delivery - Basics Hydrogen Delivery - Basics Photo of light-duty vehicle at hydrogen refueling station. Infrastructure is required to move hydrogen from the...

  3. Department of Energy - Hydrogen

    Broader source: Energy.gov (indexed) [DOE]

    Goes to.... Lighting Up Operations with Hydrogen and Fuel Cell Technology http:energy.goveerearticlesand-oscar-sustainable-mobile-lighting-goes-lighting-operations-hydro...

  4. Hydrogen Industrial Trucks

    Broader source: Energy.gov [DOE]

    Slides from the U.S. Department of Energy Hydrogen Component and System Qualification Workshop held November 4, 2010 in Livermore, CA.

  5. Hydrogen purification system

    DOE Patents [OSTI]

    Golben, Peter Mark

    2010-06-15T23:59:59.000Z

    The present invention provides a system to purify hydrogen involving the use of a hydride compressor and catalytic converters combined with a process controller.

  6. Renewable Hydrogen (Presentation)

    SciTech Connect (OSTI)

    Remick, R. J.

    2009-11-16T23:59:59.000Z

    Presentation about the United State's dependence on oil, how energy solutions are challenging, and why hydrogen should be considered as a long-term alternative for transportation fuel.

  7. Hydrogen Storage Related Links

    Broader source: Energy.gov [DOE]

    The following resources provide details about DOE-funded hydrogen storage activities, research plans and roadmaps, models and tools, and additional related links.

  8. Sustainable hydrogen production

    SciTech Connect (OSTI)

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

    1996-01-01T23:59:59.000Z

    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.

  9. DOE Hydrogen Program Overview

    Broader source: Energy.gov (indexed) [DOE]

    CO 2 emissions & energy consumption International Partnership for the Hydrogen Economy Norway An IPHE Vision: "... consumers will have the practical option of purchasing a...

  10. Hydrogen Fuel Cells

    Fuel Cell Technologies Publication and Product Library (EERE)

    The fuel cell — an energy conversion device that can efficiently capture and use the power of hydrogen — is the key to making it happen.

  11. Hydrogen permeation resistant barrier

    DOE Patents [OSTI]

    McGuire, J.C.; Brehm, W.F.

    1980-02-08T23:59:59.000Z

    A hydrogen permeation resistant barrier is formed by diffusing aluminum into an iron or nickel alloy and forming an intermetallic aluminide layer.

  12. Use of ferric sulfate: acid media for the desulfurization of model compounds of coal. [Dibenzothiophene, diphenyl sulfide, di-n-butyl sulfide

    SciTech Connect (OSTI)

    Clary, L.R.; Vermeulen, T.; Lynn, S.

    1980-12-01T23:59:59.000Z

    The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150/sup 0/C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200/sup 0/C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.

  13. Enhancing hydrogen spillover and storage

    DOE Patents [OSTI]

    Yang, Ralph T; Li, Yingwei; Lachawiec, Jr., Anthony J

    2013-02-12T23:59:59.000Z

    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 ultrasonication as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  14. Enhancing hydrogen spillover and storage

    DOE Patents [OSTI]

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

    2011-05-31T23:59:59.000Z

    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.

  15. Hydrogen Energy Technology Geoff Dutton

    E-Print Network [OSTI]

    Watson, Andrew

    Hydrogen-fuelled internal combustion engines Hydrogen-fuelled turbines Fuel cells Hydrogen systems OverallHydrogen Energy Technology Geoff Dutton April 2002 Tyndall Centre for Climate Change Research Tyndall°Centre for Climate Change Research Working Paper 17 #12;Hydrogen Energy Technology Dr Geoff Dutton

  16. Combination moisture and hydrogen getter

    DOE Patents [OSTI]

    Not Available

    1982-04-29T23:59:59.000Z

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (i) a solid acetylenic compound and (ii) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the reusltant hydrogen.

  17. Adv.SpaceRes.Vol. 21, No. 11, pp. 1455-1461, 1998 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved

    E-Print Network [OSTI]

    Atreya, Sushil

    capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon

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

    DOE Patents [OSTI]

    Hindin, Saul G. (Mendham, NJ); Roberts, George W. (Westfield, NJ)

    1980-08-12T23:59:59.000Z

    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. Electrochemical hydrogen Storage Systems

    SciTech Connect (OSTI)

    Dr. Digby Macdonald

    2010-08-09T23:59:59.000Z

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not described in the previous literature for electrochemical reduction of spent fuels, have been attempted. A quantitative analytical method for measuring the concentration of sodium borohydride in alkaline aqueous solution has been developed as part of this work and is described herein. Finally, findings from stability tests for sodium borohydride in aqueous solutions of several different compositions are reported. For aminoborane, other research institutes have developed regeneration schemes involving tributyltin hydride. In this report, electrochemical reduction experiments attempting to regenerate tributyltin hydride from tributyltin chloride (a representative by-product of the regeneration scheme) are described. These experiments were performed in the non-aqueous solvents acetonitrile and 1,2-dimethoxyethane. A non-aqueous reference electrode for electrolysis experiments in acetonitrile was developed and is described. One class of boron hydrides, called polyhedral boranes, became of interest to the DOE due to their ability to contain a sufficient amount of hydrogen to meet program goals and because of their physical and chemical safety attributes. Unfortunately, the research performed here has shown that polyhedral boranes do not react in such a way as to allow enough hydrogen to be released, nor do they appear to undergo hydrogenation from the spent fuel form back to the original hydride. After the polyhedral boranes were investigated, the project goals remained the same but the hydrogen storage material was switched by the DOE to ammonia borane. Ammonia borane was found to undergo an irreversible hydrogen release process, so a direct hydrogenation was not able to occur. To achieve the hydrogenation of the spent ammonia borane fuel, an indirect hydrogenation reaction is possible by using compounds called organotin hydrides. In this process, the organotin hydrides will hydrogenate the spent ammonia borane fuel at the cost of their own oxidation, which forms organotin halides. To enable a closed-loop cycle, our task was then to be able to hydrogenate the organotin halides back to th

  20. Florida Hydrogen Initiative

    SciTech Connect (OSTI)

    Block, David L

    2013-06-30T23:59:59.000Z

    The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety 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. Politano, Florida Institute of Technology, Melbourne, FL This project developed a hydrogen and fuel cel

  1. Sulfide controls on mercury speciation and bioavailability to methylating bacteria in sediment pore waters

    SciTech Connect (OSTI)

    Benoit, J.M. [Academy of Natural Sciences, St. Leonard, MD (United States). Estuarine Research Center] [Academy of Natural Sciences, St. Leonard, MD (United States). Estuarine Research Center; [Univ. of Maryland, Solomons, MD (United States); Gilmour, C.C.; Heyes, A. [Academy of Natural Sciences, St. Leonard, MD (United States). Estuarine Research Center] [Academy of Natural Sciences, St. Leonard, MD (United States). Estuarine Research Center; Mason, R.P. [Univ. of Maryland, Solomons, MD (United States)] [Univ. of Maryland, Solomons, MD (United States)

    1999-03-15T23:59:59.000Z

    A chemical equilibrium model for Hg complexation in sediments with sulfidic pore waters is presented. The purpose of the model was to explain observed relationships between pore water sulfide, dissolved inorganic Hg (Hg{sub D}), and bulk methylmercury (MeHg) in surficial sediments of two biogeochemically different ecosystems, the Florida Everglades and Patuxent River, MD. The model was constructed to test the hypothesis that the availability of Hg for methylation in sediments is a function of the concentration of neutral dissolved Hg complexes rather than Hg{sup 2+} or total Hg{sub D}. The model included interaction of mercury with solids containing one or two sulfide groups, and it was able to reproduce observed Hg{sub D} and bulk MeHg trends in the two ecosystems. The model is consistent with HgS{sup 0} as the dominant neutral Hg complex and the form of Hg accumulated by methylating bacteria in sulfidic pore waters. The model-estimated decline in HgS{sup 0} with increasing sulfide was consistent with the observed decline in bulk sediments MeHg. Since bacterial Hg uptake rate is one of the factors affecting methylation rate, Hg complexation models such as the one presented are helpful in understanding the factors that control MeHg production and accumulation in aquatic ecosystems.

  2. Successful removal of zinc sulfide scale restriction from a hot, deep, sour gas well

    SciTech Connect (OSTI)

    Kenrick, A.J.; Ali, S.A. [Chevron USA Production Co., New Orleans, LA (United States)

    1997-07-01T23:59:59.000Z

    Removal of zinc sulfide scale with hydrochloric acid from a hot, deep, Norphlet Sandstone gas well in the Gulf of Mexico resulted in a 29% increase in the production rates. The zinc sulfide scale was determined to be in the near-wellbore area. The presence of zinc sulfide is explained by the production of 25 ppm H{sub 2}S gas, and the loss of 50--100 bbl of zinc bromide fluid to the formation. Although zinc sulfide scale has been successfully removed with hydrochloric acid in low-to-moderate temperature wells, no analogous treatment data were available for high temperature, high pressure (HTHP) Norphlet wells. Therefore laboratory testing was initiated to identify suitable acid systems for scale removal, and select a high quality corrosion inhibitor that would mitigate detrimental effects of the selected acid on downhole tubulars and surface equipment. This case history presents the first successful use of hydrochloric acid in removing zinc sulfide scale from a HTHP Norphlet sour gas well.

  3. Asteroseismic determination of helium abundance in stellar envelopes

    E-Print Network [OSTI]

    Sarbani Basu; Anwesh Mazumdar; H. M Antia; Pierre Demarque

    2004-02-15T23:59:59.000Z

    Intermediate degree modes of the solar oscillations have previously been used to determine the solar helium abundance to a high degree of precision. However, we cannot expect to observe such modes in other stars. In this work we investigate whether low degree modes that should be available from space-based asteroseismology missions can be used to determine the helium abundance, Y, in stellar envelopes with sufficient precision. We find that the oscillatory signal in the frequencies caused by the depression in \\Gamma_1 in the second helium ionisation zone can be used to determine the envelope helium abundance of low mass main sequence stars. For frequency errors of 1 part in 10^4, we expect errors \\sigma_Y in the estimated helium abundance to range from 0.03 for 0.8M_sun stars to 0.01 for 1.2M_sun stars. The task is more complicated in evolved stars, such as subgiants, but is still feasible if the relative errors in the frequencies are less than 10^{-4}.

  4. Arsenic Sulfide Nanowire Formation on Fused Quartz Surfaces

    SciTech Connect (OSTI)

    Olmstead, J.; Riley, B.J.; Johnson, B.R.; Sundaram, S.K.

    2005-01-01T23:59:59.000Z

    Arsenic sulfide (AsxSy) nanowires were synthesized by an evaporation-condensation process in evacuated fused quartz ampoules. During the deposition process, a thin, colored film of AsxSy was deposited along the upper, cooler portion of the ampoule. The ampoule was sectioned and the deposited film analyzed using scanning electron microscopy (SEM) to characterize and semi-quantitatively evaluate the microstructural features of the deposited film. A variety of microstructures were observed that ranged from a continuous thin film (warmer portion of the ampoule), to isolated micron- and nano-scale droplets (in the intermediate portion), as well as nanowires (colder portion of the ampoule). Experiments were conducted to evaluate the effects of ampoule cleaning methods (e.g. modify surface chemistry) and quantity of source material on nanowire formation. The evolution of these microstructures in the thin film was determined to be a function of initial pressure, substrate temperature, substrate surface treatment, and initial volume of As2S3 glass. In a set of two experiments where the initial pressure, substrate thermal gradient, and surface treatment were the same, the initial quantity of As2S3 glass per internal ampoule volume was doubled from one test to the other. The results showed that AsxSy nanowires were only formed in the test with the greater initial quantity of As2S3 per internal ampoule volume. The growth data for variation in diameter (e.g. nanowire or droplet) as a function of substrate temperature was fit to an exponential trendline with the form y = Aekx, where y is the structure diameter, A = 1.25×10-3, k = 3.96×10-2, and x is the temperature with correlation coefficient, R2 = 0.979, indicating a thermally-activated process.

  5. Materials Solutions for Hydrogen Delivery in Pipelines

    SciTech Connect (OSTI)

    Ningileri, Shridas T.; Boggess, Todd A; Stalheim, Douglas

    2013-01-02T23:59:59.000Z

    The main objective of the study is as follows: Identify steel compositions/microstructures suitable for construction of new pipeline infrastructure and evaluate the potential use of the existing steel pipeline infrastructure in high pressure gaseous hydrogen applications. The microstructures of four pipeline steels were characterized and tensile testing was conducted in gaseous hydrogen and helium at pressures of 5.5 MPa (800 psi), 11 MPa (1600 psi) and 20.7 MPa (3000 psi). Based on reduction of area, two of the four steels that performed the best across the pressure range were selected for evaluation of fracture and fatigue performance in gaseous hydrogen at 5.5 MPa (800 psi) and 20.7 MPa (3000 psi). The basic format for this phase of the study is as follows: Microstructural characterization of volume fraction of phases in each alloy; Tensile testing of all four alloys in He and H{sub 2} at 5.5 MPa (800 psi), 11 MPa (1600 psi), and 20.7 MPa (3000 psi). RA performance was used to choose the two best performers for further mechanical property evaluation; Fracture testing (ASTM E1820) of two best tensile test performers in H{sub 2} at 5.5 MPa (800 psi) and 20.7 MPa (3000 psi); Fatigue testing (ASTM E647) of two best tensile test performers in H2 at 5.5 MPa (800 psi) and 20.7 MPa (3000 psi) with frequency =1.0 Hz and R-ratio=0.5 and 0.1.

  6. Materials for high-temperature hydrogen fluorine environments. Final report, June 1976-December 1978

    SciTech Connect (OSTI)

    Holcombe, C.E. Jr.; Kovach, L.

    1981-03-01T23:59:59.000Z

    A determination has been made of the stability of 35 materials under high-temperature, fluorine rich, hydrogen fluoride torch testing. Refractory materials tested included 4 borides, 3 carbides, 3 nitrides, 12 oxides, 1 oxynitride, 1 sulfide, 10 metals, and carbon (10 types). Three materials distinctly performed better than nickel: lanthanum hexaboride, calcium hexaboride, and lanthanum silicon oxynitride. Of these, lanthanum hexaboride is the best candidate tested since it has an estimated upper use temperature > 1726 K, which is above the melting point and more than 300 K above the upper use temperature of nickel.

  7. Gaseous and Liquid Hydrogen Storage

    Broader source: Energy.gov [DOE]

    Today's state of the art for hydrogen storage includes 5,000- and 10,000-psi compressed gas tanks and cryogenic liquid hydrogen tanks for on-board hydrogen storage.

  8. Renewable Resources for Hydrogen (Presentation)

    SciTech Connect (OSTI)

    Jalalzadeh-Azar, A. A.

    2010-05-03T23:59:59.000Z

    This presentation provides an overview of renewable resources for hydrogen. It was presented at the National Hydrogen Association Hydrogen Conference & Expo in Long Beach, CA, May 3-6, 2010.

  9. Hydrogen from Coal Edward Schmetz

    E-Print Network [OSTI]

    Turbines Carbon Capture & Sequestration Carbon Capture & Sequestration The Hydrogen from Coal Program Cells, Turbines, and Carbon Capture & Sequestration #12;Production Goal for Hydrogen from Coal Central Separation System PSA Membrane Membrane Carbon Sequestration Yes (87%) Yes (100%) Yes (100%) Hydrogen

  10. Hydrogen Analysis | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Hydrogen Analysis Hydrogen Analysis Presentation on Hydrogen Analysis to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004 to discuss and define role of...

  11. The Bumpy Road to Hydrogen

    E-Print Network [OSTI]

    Sperling, Dan; Ogden, Joan M

    2006-01-01T23:59:59.000Z

    It appears to us that hydrogen is a highly promising option06—16 The Bumpy Road to Hydrogen Daniel Sperling Joan OgdenThe Bumpy Road to Hydrogen 1 Daniel Sperling and Joan Ogden

  12. Hydrogen Delivery- Current Technology

    Broader source: Energy.gov [DOE]

    Hydrogen is transported from the point of production to the point of use via pipeline, over the road in cryogenic liquid trucks or gaseous tube trailers, or by rail or barge. Read on to learn more about current hydrogen delivery and storage technologies.

  13. Thick film hydrogen sensor

    DOE Patents [OSTI]

    Hoffheins, Barbara S. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1995-01-01T23:59:59.000Z

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

  14. August 2006 Hydrogen Program

    E-Print Network [OSTI]

    after the date of enactment of this Act, the Secretary shall submit to Congress a report evaluating's primary transportation fuel from petroleum, which is increasingly imported, to hydrogen, which can the energy, environmental and economic benefits of a hydrogen economy. The goals and milestones

  15. Hydrogen Storage CODES & STANDARDS

    E-Print Network [OSTI]

    automotive start-up. · Air/Thermal/Water Management ­ improved air systems, high temperature membranes, heat to pump Hydrogen Fuel/ Storage/ Infrastructure $45/kW (2010) $30kW (2015) 325 W/kg 220 W/L 60% (hydrogen system Component Air management, sensors, MEA's, membranes, Bipolar Plates, fuel processor reactor zones

  16. Hydrogen Fuel Quality

    SciTech Connect (OSTI)

    Rockward, Tommy [Los Alamos National Laboratory

    2012-07-16T23:59:59.000Z

    For the past 6 years, open discussions and/or meetings have been held and are still on-going with OEM, Hydrogen Suppliers, other test facilities from the North America Team and International collaborators regarding experimental results, fuel clean-up cost, modeling, and analytical techniques to help determine levels of constituents for the development of an international standard for hydrogen fuel quality (ISO TC197 WG-12). Significant progress has been made. The process for the fuel standard is entering final stages as a result of the technical accomplishments. The objectives are to: (1) Determine the allowable levels of hydrogen fuel contaminants in support of the development of science-based international standards for hydrogen fuel quality (ISO TC197 WG-12); and (2) Validate the ASTM test method for determining low levels of non-hydrogen constituents.

  17. Focal depth measurement of scanning helium ion microscope

    SciTech Connect (OSTI)

    Guo, Hongxuan, E-mail: Guo.hongxuan@nims.go.jp [Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Itoh, Hiroshi; Wang, Chunmei [Active State Technology Research Group, Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST), 1-1 Umezono 1-Chome, Tsukuba, Ibaraki 305-8568 (Japan); Zhang, Han; Fujita, Daisuke [Nano Characterization Unit, Advanced Key Technologies Division, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-07-14T23:59:59.000Z

    When facing the challenges of critical dimension measurement of complicated nanostructures, such as of the three dimension integrated circuit, characterization of the focal depth of microscopes is important. In this Letter, we developed a method for characterizing the focal depth of a scanning helium ion microscope (HIM) by using an atomic force microscope tip characterizer (ATC). The ATC was tilted in a sample chamber at an angle to the scanning plan. Secondary electron images (SEIs) were obtained at different positions of the ATC. The edge resolution of the SEIs shows the nominal diameters of the helium ion beam at different focal levels. With this method, the nominal shapes of the helium ion beams were obtained with different apertures. Our results show that a small aperture is necessary to get a high spatial resolution and high depth of field images with HIM. This work provides a method for characterizing and improving the performance of HIM.

  18. Fast production of Bose-Einstein condensates of metastable Helium

    E-Print Network [OSTI]

    Bouton, Q; Hoendervanger, A L; Nogrette, F; Aspect, A; Westbrook, C I; Clément, D

    2015-01-01T23:59:59.000Z

    We report on the Bose-Einstein condensation of metastable Helium-4 atoms using a hybrid approach, consisting of a magnetic quadrupole and a crossed optical dipole trap. In our setup we cross the phase transition with 2x10^6 atoms, and we obtain pure condensates of 5x10^5 atoms in the optical trap. This novel approach to cooling Helium-4 provides enhanced cycle stability, large optical access to the atoms and results in production of a condensate every 6 seconds - a factor 3 faster than the state-of-the-art. This speed-up will dramatically reduce the data acquisition time needed for the measurement of many particle correlations, made possible by the ability of metastable Helium to be detected individually.

  19. Spin-based quantum computing using electrons on liquid helium

    E-Print Network [OSTI]

    S. A. Lyon

    2006-11-17T23:59:59.000Z

    Numerous physical systems have been proposed for constructing quantum computers, but formidable obstacles stand in the way of making even modest systems with a few hundred quantum bits (qubits). Several approaches utilize the spin of an electron as the qubit. Here it is suggested that the spin of electrons floating on the surface of liquid helium will make excellent qubits. These electrons can be electrostatically held and manipulated much like electrons in semiconductor heterostructures, but being in a vacuum the spins on helium suffer much less decoherence. In particular, the spin orbit interaction is reduced so that moving the qubits with voltages applied to gates has little effect on their coherence. Remaining sources of decoherence are considered and it is found that coherence times for electron spins on helium can be expected to exceed 100 s. It is shown how to obtain a controlled-NOT operation between two qubits using the magnetic dipole-dipole interaction.

  20. Helium and mercury in the central Seward Peninsula

    SciTech Connect (OSTI)

    Wescott, E.; Ruscetta, C.A.; Foley, D. (eds.)

    1981-05-01T23:59:59.000Z

    The central Seward Peninsula, Alaska, has one Known Geothermal Resource Area (KGRA) at Pilgrim Springs, and has recent volcanic flows, fault systems, topographic and tectonic features which can be explained by a rift model. As part of a geothermal reconnaissance of the area we used helium and mercury concentrations in soil as indicators of geothermal resources. The largest helium concentrations were found in the vicinity of the Pilgrims Springs KGRA, and indicate prime drilling sites. Five profile lines were run across the suspected rift system. Significant helium anomalies were found on several of the traverses, where future exploration might be concentrated. Mercury values showed a great range of variability on the traverses, and seem unreliable as geothermal indicators except in the vicinity of the Pilgrim Springs. Permafrost at the surface resulting in variations in sampling depth may contribute to the mercury variations.

  1. Solvation of molecules in superfluid helium enhances the “interaction induced localization” effect

    SciTech Connect (OSTI)

    Walewski, ?ukasz, E-mail: Lukasz.Walewski@theochem.rub.de; Forbert, Harald; Marx, Dominik [Lehrstuhl für Theoretische Chemie, Ruhr–Universität Bochum, 44780 Bochum (Germany)] [Lehrstuhl für Theoretische Chemie, Ruhr–Universität Bochum, 44780 Bochum (Germany)

    2014-04-14T23:59:59.000Z

    Atomic nuclei become delocalized at low temperatures as a result of quantum effects, whereas they are point-like in the high temperature (classical) limit. For non-interacting nuclei, the delocalization upon lowering the temperature is quantitatively described in terms of the thermal de Broglie wavelength of free particles. Clearly, light non-interacting nuclei – the proton being a prominent one – are much more delocalized at low temperatures compared to heavy nuclei, such as non-interacting oxygen having water in mind. However, strong interactions due to chemical bonding in conjunction with ultra-low temperatures characteristic to superfluid helium nanodroplets change this common picture substantially for nuclei in molecules or clusters. It turns out that protons shared in hydrogen bonds undergo an extreme “interaction induced localization” at temperatures on the order of 1 K, which compresses the protonic spatial distributions to the size of the much heavier donor or acceptor atoms, such as O or Cl nuclei, corresponding to about 0.1% of the volume occupied by a non-interacting proton at the same temperature. Moreover, applying our recently developed hybrid ab initio path integral molecular dynamics/bosonic path integral Monte Carlo quantum simulation technique to a HCl/water cluster, HCl(H{sub 2}O){sub 4}, we find that helium solvation has a significant additional localizing effect of up to about 30% in volume. In particular, the solvent-induced excess localization is the stronger the lesser the given nucleus is already localized in the gas phase reference situation.

  2. Hydrogen Data Book from the Hydrogen Analysis Resource Center

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Hydrogen Data Book contains a wide range of factual information on hydrogen and fuel cells (e.g., hydrogen properties, hydrogen production and delivery data, and information on fuel cells and fuel cell vehicles), and it also provides other data that might be useful in analyses of hydrogen infrastructure in the United States (e.g., demographic data and data on energy supply and/or infrastructure). ItĆs made available from the Hydrogen Analysis Resource Center along with a wealth of related information. The related information includes guidelines for DOE Hydrogen Program Analysis, various calculator tools, a hydrogen glossary, related websites, and analysis tools relevant to hydrogen and fuel cells. [From http://hydrogen.pnl.gov/cocoon/morf/hydrogen

  3. Sandia National Laboratories: Hydrogen Infrastructure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogen Infrastructure Widespread Hydrogen Fueling Infrastructure Is the Goal of H2FIRST Project On June 4, 2014, in Capabilities, Center for Infrastructure Research and...

  4. Sandia National Laboratories: Hydrogen Safety

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogen Safety Solar Thermochemical Hydrogen Production On June 13, 2014, in SNL maintains the equipment, experts, and partnerships required to develop technology for solar...

  5. Hydrogen Storage Technical Team Roadmap

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and technology pathways are impacted by their analyses. These technical teams include Fuel Cells, Fuel Pathway Integration, Hydrogen Delivery, Hydrogen Production, Materials,...

  6. Turing Water into Hydrogen Fuel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Turning Water into Hydrogen Fuel Turning Water into Hydrogen Fuel New method creates highly reactive catalytic surface, packed with hydroxyl species May 15, 2012 | Tags: Franklin,...

  7. Hydrogen Delivery Infrastructure Option Analysis

    Broader source: Energy.gov (indexed) [DOE]

    Infrastructure Hydrogen Delivery Infrastructure Option Analysis Option Analysis DOE and FreedomCAR & Fuel Partnership Hydrogen Delivery and On-Board Storage Analysis Workshop...

  8. Experimental partitioning of uranium between liquid iron sulfide and liquid silicate: Implications for radioactivity in the Earth's core

    E-Print Network [OSTI]

    Minarik, William

    Experimental partitioning of uranium between liquid iron sulfide and liquid silicate: Implications Measurable uranium (U) is found in metal sulfide liquids in equilibrium with molten silicate at conditions shows that K is depleted in the Earth by $50%, while U and Th are slightly enriched (Palme and O

  9. The latest developments and outlook for hydrogen liquefaction technology

    SciTech Connect (OSTI)

    Ohlig, K.; Decker, L. [Linde Kryotechnik AG, Pfungen, CH-8422 (Switzerland)

    2014-01-29T23:59:59.000Z

    Liquefied hydrogen is presently mainly used for space applications and the semiconductor industry. While clean energy applications, for e.g. the automotive sector, currently contribute to this demand with a small share only, their demand may see a significant boost in the next years with the need for large scale liquefaction plants exceeding the current plant sizes by far. Hydrogen liquefaction for small scale plants with a maximum capacity of 3 tons per day (tpd) is accomplished with a Brayton refrigeration cycle using helium as refrigerant. This technology is characterized by low investment costs but lower process efficiency and hence higher operating costs. For larger plants, a hydrogen Claude cycle is used, characterized by higher investment but lower operating costs. However, liquefaction plants meeting the potentially high demand in the clean energy sector will need further optimization with regard to energy efficiency and hence operating costs. The present paper gives an overview of the currently applied technologies, including their thermodynamic and technical background. Areas of improvement are identified to derive process concepts for future large scale hydrogen liquefaction plants meeting the needs of clean energy applications with optimized energy efficiency and hence minimized operating costs. Compared to studies in this field, this paper focuses on application of new technology and innovative concepts which are either readily available or will require short qualification procedures. They will hence allow implementation in plants in the close future.

  10. CAN HYDROGEN WIN?: EXPLORING SCENARIOS FOR HYDROGEN

    E-Print Network [OSTI]

    -constrained world. Long-run simulations were created using CIMS, a hybrid energy-economy model supply submodel was built to simulate economies of scale in infrastructure. Capital costs, technology such as biofuel plug-in hybrids, but did well when biofuels were removed or priced excessively. Hydrogen fuel

  11. Analytical modeling of localized surface plasmon resonance in heterostructure copper sulfide nanocrystals

    SciTech Connect (OSTI)

    Caldwell, Andrew H.; Ha, Don-Hyung; Robinson, Richard D., E-mail: rdr82@cornell.edu [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Ding, Xiaoyue [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)

    2014-10-28T23:59:59.000Z

    Localized surface plasmon resonance (LSPR) in semiconductor nanocrystals is a relatively new field of investigation that promises greater tunability of plasmonic properties compared to metal nanoparticles. A novel process by which the LSPR in semiconductor nanocrystals can be altered is through heterostructure formation arising from solution-based cation exchange. Herein, we describe the development of an analytical model of LSPR in heterostructure copper sulfide-zinc sulfide nanocrystals synthesized via a cation exchange reaction between copper sulfide (Cu{sub 1.81}S) nanocrystals and Zn ions. The cation exchange reaction produces dual-interface, heterostructure nanocrystals in which the geometry of the copper sulfide phase can be tuned from a sphere to a thin disk separating symmetrically-grown sulfide (ZnS) grains. Drude model electronic conduction and Mie-Gans theory are applied to describe how the LSPR wavelength changes during cation exchange, taking into account the morphology evolution and changes to the local permittivity. The results of the modeling indicate that the presence of the ZnS grains has a significant effect on the out-of-plane LSPR mode. By comparing the results of the model to previous studies on solid-solid phase transformations of copper sulfide in these nanocrystals during cation exchange, we show that the carrier concentration is independent of the copper vacancy concentration dictated by its atomic phase. The evolution of the effective carrier concentration calculated from the model suggests that the out-of-plane resonance mode is dominant. The classical model was compared to a simplified quantum mechanical model which suggested that quantum mechanical effects become significant when the characteristic size is less than ?8 nm. Overall, we find that the analytical models are not accurate for these heterostructured semiconductor nanocrystals, indicating the need for new model development for this emerging field.

  12. Non-Sticking of Helium Buffer Gas to Hydrocarbons

    E-Print Network [OSTI]

    Croft, James F E

    2014-01-01T23:59:59.000Z

    Lifetimes of complexes formed during helium-hydrocarbon collisions at low temperature are estimated for symmetric top hydrocarbons. The lifetimes are obtained using a density-of-states approach. In general the lifetimes are less than 10-100 ns, and are found to decrease with increasing hydrocarbon size. This suggests that clustering will not limit precision spectroscopy in helium buffer gas experiments. Lifetimes are computed for noble-gas benzene collisions and are found to be in reasonable agreement with lifetimes obtained from classical trajectories as reported by Cui {\\it et al}.

  13. $?^4$ Ry corrections to singlet states of helium

    E-Print Network [OSTI]

    Krzysztof Pachucki

    2006-07-07T23:59:59.000Z

    Corrections of order $\\alpha^4$Ry are calculated for the singlet states $1^1S_0$ and $2^1S_0$ of the helium atom. The result for $1^1S_0$ state is in slight disagreement with that of Korobov and Yelkhovsky in [Phys. Rev. Lett. {\\bf 87}, 193003 (2001)]. The results obtained lead to a significant improvement of transition frequencies between low lying levels of the helium atom. In particular theoretical predictions for the $2^1S_0 - 1^1S_0$ transition are found to be in disagreement with experimental values.

  14. Electron scattering in helium for Monte Carlo simulations

    SciTech Connect (OSTI)

    Khrabrov, Alexander V.; Kaganovich, Igor D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2012-09-15T23:59:59.000Z

    An analytical approximation for differential cross-section of electron scattering on helium atoms is introduced. It is intended for Monte Carlo simulations, which, instead of angular distributions based on experimental data (or on first-principle calculations), usually rely on approximations that are accurate yet numerically efficient. The approximation is based on the screened-Coulomb differential cross-section with energy-dependent screening. For helium, a two-pole approximation of the screening parameter is found to be highly accurate over a wide range of energies.

  15. Cavitation Density of Superfluid Helium-4 around 1 K

    E-Print Network [OSTI]

    An Qu; Azer Trimeche; Jacques Dupont-roc; Jules Grucker; Philippe Jacquier

    2015-04-14T23:59:59.000Z

    Using an optical interferomertric method, the homogeneous cavitation density of superfluid helium at $T=0.96\\,$K is measured and found to be $\\rho_{cav}=0.1338\\pm0.0002\\rm\\,g.cm^{-3}$. A well established equation of state for liquid helium at negative pressures converts this to the cavitation pressure $P_{cav}=-5.1\\pm0.1\\,$bar. This cavitation pressure is consistent with a model taking into account the presence of quantized vortices, but disagrees with previously published experimental values of $P_{cav}$.

  16. Detection and Imaging of He_2 Molecules in Superfluid Helium

    E-Print Network [OSTI]

    W. G. Rellergert; S. B. Cahn; A. Garvan; J. C. Hanson; W. H. Lippincott; J. A. Nikkel; D. N. McKinsey

    2007-12-18T23:59:59.000Z

    We present data that show a cycling transition can be used to detect and image metastable He$_2$ triplet molecules in superfluid helium. We demonstrate that limitations on the cycling efficiency due to the vibrational structure of the molecule can be mitigated by the use of repumping lasers. Images of the molecules obtained using the method are also shown. This technique gives rise to a new kind of ionizing radiation detector. The use of He$_2$ triplet molecules as tracer particles in the superfluid promises to be a powerful tool for visualization of both quantum and classical turbulence in liquid helium.

  17. Spectroscopy of barium atoms in liquid and solid helium matrices

    SciTech Connect (OSTI)

    Lebedev, V.; Moroshkin, P.; Weis, A. [Departement de Physique, Universite de Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)

    2011-08-15T23:59:59.000Z

    We present an exhaustive overview of optical absorption and laser-induced fluorescence lines of Ba atoms in liquid and solid helium matrices in visible and near-infrared spectral ranges. Due to the increased density of isolated atoms, we have found a large number of spectral lines that were not observed in condensed helium matrices before. We have also measured the lifetimes of metastable states. The lowest {sup 3}D{sub 1} metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.

  18. New technology for sulfide reduction and increased oil recovery. Second quarter progress report

    SciTech Connect (OSTI)

    NONE

    1998-12-20T23:59:59.000Z

    The purpose of this project is to demonstrate reduction of sulfide contamination, as well as possible improvement of production in oil and gas production systems. This will be accomplished by application of the BioCompetitive Exclusion (BCX) process developed by GMT. A broad spectrum of well types and geographical locations is anticipated. The BCX process is designed to manipulate indigenous reservoir bacteria with the addition of synergistic inorganic chemical formulae. These treatments will stimulate growth of beneficial microbes, while suppressing metabolic activity of sulfate reducing bacteria (SRB), the primary source of harmful sulfide production. Progress in 7 oil and gas fields is summarized.

  19. Advancing the Hydrogen Safety Knowledge Base

    SciTech Connect (OSTI)

    Weiner, Steven C.

    2014-12-01T23:59:59.000Z

    A White Paper of the International Energy Agency Hydrogen Implementing Agreement Task 31 - Hydrogen Safety

  20. System Evaluation and Economic Analysis of a HTGR Powered High-Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect (OSTI)

    Michael G. McKellar; Edwin A. Harvego; Anastasia A. Gandrik

    2010-10-01T23:59:59.000Z

    A design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The power conversion unit will be a Rankine steam cycle with a power conversion efficiency of 40%. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 40.4% at a hydrogen production rate of 1.75 kg/s and an oxygen production rate of 13.8 kg/s. An economic analysis of this plant was performed with realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.67/kg of hydrogen assuming an internal rate of return, IRR, of 12% and a debt to equity ratio of 80%/20%. A second analysis shows that if the power cycle efficiency increases to 44.4%, the hydrogen production efficiency increases to 42.8% and the hydrogen and oxygen production rates are 1.85 kg/s and 14.6 kg/s respectively. At the higher power cycle efficiency and an IRR of 12% the cost of hydrogen production is $3.50/kg.