Hydrogen in disordered and amorphous solids

International Nuclear Information System (INIS)

Bambakidis, G; Bowman, R.C.

1986-01-01

This book presents information on the following topoics: elements of the theory of amorphous semiconductors; electronic structure of alpha-SiH; fluctuation induced gap states in amorphous hydrogenated silicon; hydrogen on semiconductor surfaces; the influence of hydrogen on the defects and instabilities in hydrogenated amorphous silicon; deuteron magnetic resonance in some amorphous semiconductors; formation of amorphous metals by solid state reactions of hydrogen with an intermetallic compound; NMR studies of the hydrides of disordered and amorphous alloys; neutron vibrational spectroscopy of disordered metal-hydrogen system; dynamical disorder of hydrogen in LaNi /SUB 5-y/ M /SUB y/ hydrides studied by quasi-elastic neutron scattering; recent studies of intermetallic hydrides; tritium in Pd and Pd /SUB 0.80/ Sg /SUB 0.20/ ; and determination of hydrogen concentration in thin films of absorbing materials

Solid Aluminum Borohydrides for Prospective Hydrogen Storage.

Science.gov (United States)

Dovgaliuk, Iurii; Safin, Damir A; Tumanov, Nikolay A; Morelle, Fabrice; Moulai, Adel; Černý, Radovan; Łodziana, Zbigniew; Devillers, Michel; Filinchuk, Yaroslav

2017-12-08

Metal borohydrides are intensively researched as high-capacity hydrogen storage materials. Aluminum is a cheap, light, and abundant element and Al 3+ can serve as a template for reversible dehydrogenation. However, Al(BH 4 ) 3 , containing 16.9 wt % of hydrogen, has a low boiling point, is explosive on air and has poor storage stability. A new family of mixed-cation borohydrides M[Al(BH 4 ) 4 ], which are all solid under ambient conditions, show diverse thermal decomposition behaviors: Al(BH 4 ) 3 is released for M=Li + or Na + , whereas heavier derivatives evolve hydrogen and diborane. NH 4 [Al(BH 4 ) 4 ], containing both protic and hydridic hydrogen, has the lowest decomposition temperature of 35 °C and yields Al(BH 4 ) 3 ⋅NHBH and hydrogen. The decomposition temperatures, correlated with the cations' ionic potential, show that M[Al(BH 4 ) 4 ] species are in the most practical stability window. This family of solids, with convenient and versatile properties, puts aluminum borohydride chemistry in the mainstream of hydrogen storage research, for example, for the development of reactive hydride composites with increased hydrogen content. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical and thermal energy discharge from tritiated solid hydrogen

International Nuclear Information System (INIS)

Magnotta, F.; Mapoles, E.R.; Collins, G.W.; Souers, P.C.

1991-01-01

The authors are investigating mechanisms of energy storage and release in tritiated solid hydrogens, by a variety of techniques including ESR, NMR and thermal and optical emission. The nuclear decay of a triton in solid hydrogen initiates the conversion of nuclear energy into stored chemical energy by producing unpaired hydrogen atoms which are trapped within the molecular lattice. The ability to store large quantities of atoms in this manner has been demonstrated and can serve as a basis for new forms of high energy density materials. This paper presents preliminary results of a study of the optical emission from solid hydrogen containing tritium over the visible and near infrared (NIR) spectral regions. Specifically, they have studied optical emission from DT and T 2 using CCD, silicon diode and germanium diode arrays. 8 refs., 6 figs

Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss

Science.gov (United States)

Malerød-Fjeld, Harald; Clark, Daniel; Yuste-Tirados, Irene; Zanón, Raquel; Catalán-Martinez, David; Beeaff, Dustin; Morejudo, Selene H.; Vestre, Per K.; Norby, Truls; Haugsrud, Reidar; Serra, José M.; Kjølseth, Christian

2017-11-01

Conventional production of hydrogen requires large industrial plants to minimize energy losses and capital costs associated with steam reforming, water-gas shift, product separation and compression. Here we present a protonic membrane reformer (PMR) that produces high-purity hydrogen from steam methane reforming in a single-stage process with near-zero energy loss. We use a BaZrO3-based proton-conducting electrolyte deposited as a dense film on a porous Ni composite electrode with dual function as a reforming catalyst. At 800 °C, we achieve full methane conversion by removing 99% of the formed hydrogen, which is simultaneously compressed electrochemically up to 50 bar. A thermally balanced operation regime is achieved by coupling several thermo-chemical processes. Modelling of a small-scale (10 kg H2 day-1) hydrogen plant reveals an overall energy efficiency of >87%. The results suggest that future declining electricity prices could make PMRs a competitive alternative for industrial-scale hydrogen plants integrating CO2 capture.

Ultrahigh-pressure transitions in solid hydrogen

International Nuclear Information System (INIS)

Mao, H.; Hemley, R.J.

1994-01-01

During the past five years, major progress has been made in the experimental study of solid hydrogen at ultrahigh pressures as a result of developments in diamond-cell technology. Pressures at which metallization has been predicted to occur have been reached (250--300 Gigapascals). Detailed studies of the dynamic, structural, and electronic properties of dense hydrogen reveal a system unexpectedly rich in physical phenomena, exhibiting a variety of transitions at ultrahigh pressures. This colloquium explores the study of dense hydrogen as an archetypal problem in condensed-matter physics

Theory of nuclear quadrupole interactions in solid hydrogen fluoride

International Nuclear Information System (INIS)

Mohamed, N.S.; Sahoo, N.; Das, T.P.; Kelires, P.C.

1990-01-01

The nuclear quadrupole interaction of 19 F * (I=5/2) nucleus in solid hydrogen fluoride has been studied using the Hartree Fock cluster technique to understand the influence of both intrachain hydrogen bonding effects and the weak interchain interaction. On the basis of our investigations, the 34.04 MHz coupling constant observed by TDPAD measurements has been ascribed to the bulk solid while the observed 40.13 MHz coupling constant is suggested as arising from a small two- or three-molecule cluster produced during the proton irradiation process. Two alternate explanations are offered for the origin of coupling constants close to 40 MHz in a number of solid hydrocarbons containing hydrogen and fluorine ligands. (orig.)

Indentation of elastically soft and plastically compressible solids

DEFF Research Database (Denmark)

Needleman, A.; Tvergaard, Viggo; Van der Giessen, E.

2015-01-01

rapidly for small deviations from plastic incompressibility and then decreases rather slowly for values of the plastic Poisson's ratio less than 0.25. For both soft elasticity and plastic compressibility, the main reason for the lower values of indentation hardness is related to the reduction......The effect of soft elasticity, i.e., a relatively small value of the ratio of Young's modulus to yield strength and plastic compressibility on the indentation of isotropically hardening elastic-viscoplastic solids is investigated. Calculations are carried out for indentation of a perfectly sticking...... rigid sharp indenter into a cylinder modeling indentation of a half space. The material is characterized by a finite strain elastic-viscoplastic constitutive relation that allows for plastic as well as elastic compressibility. Both soft elasticity and plastic compressibility significantly reduce...

Advanced materials for solid state hydrogen storage: “Thermal engineering issues”

International Nuclear Information System (INIS)

Srinivasa Murthy, S.; Anil Kumar, E.

2014-01-01

Hydrogen has been widely recognized as the “Energy Carrier” of the future. Efficient, reliable, economical and safe storage and delivery of hydrogen form important aspects in achieving success of the “Hydrogen Economy”. Gravimetric and volumetric storage capacities become important when one considers portable and mobile applications of hydrogen. In the case of solid state hydrogen storage, the gas is reversibly embedded (by physisorption and/or chemisorption) in a solid matrix. A wide variety of materials such as intermetallics, physisorbents, complex hydrides/alanates, metal organic frameworks, etc. have been investigated as possible storage media. This paper discusses the feasibility of lithium– and sodium–aluminum hydrides with emphasis on their thermodynamic and thermo-physical properties. Drawbacks such as poor heat transfer characteristics and poor kinetics demand special attention to the thermal design of solid state storage devices. - Highlights: • Advanced materials suitable for solid state hydrogen storage are discussed. • Issues related to thermodynamic and thermo-physical properties of hydriding materials are brought out. • Hydriding and dehydriding behavior including sorption kinetics of complex hydrides with emphasis on alanates are explained

Equation of state of solid hydrogen at 0 deg K. A bibliography

International Nuclear Information System (INIS)

Masse, J.-L.

1976-02-01

A bibliography on solid hydrogen at 0 deg K and its equation of state is presented. The isotopic derivatives of H 2 , such as D 2 , HD... have been also considered. Both phases of solid hydrogen have been studied: the molecular phase, stable at low pressure, and the hypothetical metallic phase which must be stable at high pressure. The study of the molecular phase is preceded by a study of the (H 2 ,H 2 ) system of two interacting H 2 , molecules, the knowledge of this interaction being necessary for the evaluation of the properties of the molecular solid phase. The three systems: (H 2 ,H 2 ) and molecular solid and metallic hydrogen have been considered from the experimental and theoretical points of view. The properties of these systems, the measurement or the calculation of which are described, have been chosen on account of their usefulness for the research of the equation of state of molecular or metallic solid hydrogen. Different interaction potentials of two hydrogen molecules and different equations of state of molecular solid hydrogen are given. Some theoretical studies are proposed [fr

Electrochemical hydrogen isotope sensor based on solid electrolytes

International Nuclear Information System (INIS)

Matsumoto, Hiroshige; Hayashi, Hiroyuki; Iwahara, Hiroyasu

2002-01-01

An electrochemical sensor of hydrogen isotopes based on solid electrolytes for determining the hydrogen isotope ratios and/or total hydrogen pressures in gases has been developed. This paper describes the methodology of the hydrogen isotope sensing together with experimental results. When hydrogen isotope gases are introduced to an electrochemical cell using a proton-conducting electrolyte (hydrogen isotope cell), the electromotive force (EMF) of the cell agrees with that theoretically estimated. The EMF signals can be used for the determination of the hydrogen isotope ratio in gases if the total hydrogen pressure is predetermined. By supplementary use of an oxide ion conductor cell, both the ratio and total pressure of the hydrogen isotopes can be simultaneously determined. (author)

A study on the fire response of compressed hydrogen gas vehicles

Energy Technology Data Exchange (ETDEWEB)

Tamura, Yohsuke; Tomioka, Junichi; Suzuki, Jinji [Japan Automobile Research Institute (Japan)

2010-07-01

To investigate the events that could arise when fighting fires in vehicles with compressed hydrogen CFRP (carbon fiber reinforced plastic) composite cylinders, we conducted experiments to examine whether a hydrogen jet flame caused by the activation of the pressure relief device (PRD) can extinguished and how spraying water influences the cylinder and PRD. The experiments clarified that the hydrogen jet flame cannot be extinguished easily with water or dry powder extinguishers and that spraying water during activation of the PRD may result in closure of the PRD, but is useful for maintaining the strength of CFRP composite cylinders for vehicles. (orig.)

Indentation of elastically soft and plastically compressible solids

NARCIS (Netherlands)

Needleman, A.; Tvergaard, V.; Van der Giessen, E.

The effect of soft elasticity, i.e., a relatively small value of the ratio of Young's modulus to yield strength and plastic compressibility on the indentation of isotropically hardening elastic-viscoplastic solids is investigated. Calculations are carried out for indentation of a perfectly sticking

Effects of hydrogen bonds on solid state TATB, RDX, and DATB under high pressures

International Nuclear Information System (INIS)

Guo Feng; Hu Hai-Quan; Zhang Hong; Cheng Xin-Lu

2014-01-01

To probe the behavior of hydrogen bonds in solid energetic materials, we conduct ReaxFF and SCC–DFTB molecular dynamics simulations of crystalline TATB, RDX, and DATB. By comparing the intra- and inter-molecular hydrogen bonding rates, we find that the crystal structures are stabilized by inter-molecular hydrogen bond networks. Under high-pressure, the inter- and intra-molecular hydrogen bonds in solid TATB and DATB are nearly equivalent. The hydrogen bonds in solid TATB and DATB are much shorter than in solid RDX, which suggests strong hydrogen bond interactions existing in these energetic materials. Stretching of the C–H bond is observed in solid RDX, which may lead to further decomposition and even detonation. (condensed matter: structural, mechanical, and thermal properties)

A comparative analysis of the cryo-compression and cryo-adsorption hydrogen storage methods

Energy Technology Data Exchange (ETDEWEB)

Petitpas, G [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Benard, P [Universite du Quebec a Trois-Rivieres (Canada); Klebanoff, L E [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Xiao, J [Universite du Quebec a Trois-Rivieres (Canada); Aceves, S M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-07-01

While conventional low-pressure LH₂ dewars have existed for decades, advanced methods of cryogenic hydrogen storage have recently been developed. These advanced methods are cryo-compression and cryo-adsorption hydrogen storage, which operate best in the temperature range 30–100 K. We present a comparative analysis of both approaches for cryogenic hydrogen storage, examining how pressure and/or sorbent materials are used to effectively increase onboard H₂ density and dormancy. We start by reviewing some basic aspects of LH₂ properties and conventional means of storing it. From there we describe the cryo-compression and cryo-adsorption hydrogen storage methods, and then explore the relationship between them, clarifying the materials science and physics of the two approaches in trying to solve the same hydrogen storage task (~5–8 kg H₂, typical of light duty vehicles). Assuming that the balance of plant and the available volume for the storage system in the vehicle are identical for both approaches, the comparison focuses on how the respective storage capacities, vessel weight and dormancy vary as a function of temperature, pressure and type of cryo-adsorption material (especially, powder MOF-5 and MIL-101). By performing a comparative analysis, we clarify the science of each approach individually, identify the regimes where the attributes of each can be maximized, elucidate the properties of these systems during refueling, and probe the possible benefits of a combined “hybrid” system with both cryo-adsorption and cryo-compression phenomena operating at the same time. In addition the relationships found between onboard H₂ capacity, pressure vessel and/or sorbent mass and dormancy as a function of rated pressure, type of sorbent material and fueling conditions are useful as general designing guidelines in future engineering efforts using these two hydrogen storage approaches.

Solid solutions of hydrogen in niobium, molybdenum and their alloys

International Nuclear Information System (INIS)

Ishikawa, T.T.

1981-01-01

The solubility of hydrogen in niobium, molybdenum and niobium-molybdenum alloys with varying atomic fraction of molybdenum from 0.15 to 0.75 was measured on the temperature range of 673 0 K to 1273 0 k for one atmosphere hydrogen pressure. The experimental technique involved the saturation of the solvent metal or alloy with hydrogen, followed by quenching and analysis of the solid solution. The results obtained of hydrogen solubility are consistent with the quasi-regular model for the dilute interstitial solid solutions. The partial molar enthalpy and partial molar entropy in excess of the dissolved hydrogen atoms were calculated from data of solubility versus reciprocal doping temperature. The variation of the relative partial molar enthalpy of hydrogen dissolved in niobium-molybdenum alloys, with the increase of molybdenum content of the alloy was analized. (Author) [pt

Dynamic Compression Experiments on Hydrogen and Deuterium in the Warm Dense Liquid.

Science.gov (United States)

Desjarlais, Michael; McCoy, Chad; Cochrane, Kyle; Mattsson, Thomas; Knudson, Marcus; Redmer, Ronald

2017-06-01

Recently a shock-ramp platform has been developed on the Z Accelerator to access off-Hugoniot states in liquids. The accelerator delivers a two-step current pulse; the first accelerates the electrode to a constant velocity, which upon impact with the sample cell creates a well-defined shock, the subsequent current rise produces ramp compression from the initially shocked state producing relatively cool (1-2 kK), high pressure (>300 GPa), high compression (10 to 15-fold compression) states. This technique allows experimental access to the region of phase space where hydrogen is predicted to undergo a first-order phase transition from an insulating molecular-like to a conducting atomic-like liquid. Here we discuss the experimental platform, survey various theoretical predictions for the liquid-liquid, insulator-to-metal transition in hydrogen, and present results of experiments on both deuterium and hydrogen that clearly show an abrupt transition to a metallic state. We also present results from recent experiments at higher temperatures (3-4 kK) and compare the observations to both first-principles theory and previous step-wise loading experiments that exhibited a minimum metallic conductivity. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Nano-porous inorganic-organic hybrid solids: some new materials for hydrogen storage?

International Nuclear Information System (INIS)

Serre, Ch.; Loiseau, Th.; Devic, T.; Ferey, G.; Latroche, M.; Llewellyn, Ph.; Chang, J.S.

2007-01-01

Recently have been studied chromium and aluminium carboxylates MIL-53(Cr, Al), formed from an assembly of octahedrons chains and for hybrid solids formed with octahedrons trimers (MIL-100 and MIL-101). The compounds MIL-53(Cr, Al) are microporous (φ ∼ 8 Angstroms, while the solids MIL-100 and MIL-101 have very large porous volumes (V ∼ 380-700000 (Angstroms) 3 ), meso-pores (φ ∼ 25-34 Angstroms) and a zeolitic architecture. The resulting specific surface areas are important (between 1000 m 2 .g -1 for the MIL-53 solids, until 4000 m 2 .g -1 for the MIL-101 compound. Here is presented their hydrogen adsorption properties, at 77 K and 298 K. The hydrogen adsorption kinetics has been tested on the MIL-53(Cr) solid at 77 K. Hydrogen adsorption micro-calorimetry experiments have been carried out on these solids between 0 and 1 bar in order to obtain data on the strongest interactions between hydrogen and the porous basic structure. (O.M.)

Composite high-pressure vessels for hydrogen storage in mobile application. Pt. 1 / Light weight composite cylinders for compressed hydrogen. Pt. 2 - custom made hydrogen storage tanks and vessels

Energy Technology Data Exchange (ETDEWEB)

Rasche, C. [MCS Cylinder Systems GmbH, Dinslaken (Germany)

2000-07-01

Recent developments on fuel cell technology demonstrated the feasibility of propelling vehicles by converting fuel directly into electricity. Fuel cells conveniently use either compressed (CGH{sub 2}) or liquid hydrogen (LH{sub 2}) or methanol as the fuel source from a tank. Mobile storage of these fuelling will become an urgent need as this technology will come into series production expected for 2010. Due to the requirements on mobile hydrogen storage and the energy losses in the hydrogen-to-application-chain, a light-weight and energetic qualities and minimise ist bulky nature. Mobile storage of hydrogen can be realised either at high pressure values (> 20 MPa) or at deep temperatures (<-253 C). CGH{sub 2}: In the last few years, the introduction of natural gas driven vehicles has seen the development of compact mobile pressurised gas tanks in principle, this storage technique is also applicable for the compressed storage of hydrogen at filling pressures of > 20 MPa. LH{sub 2} : Storing hydrogen or natural gases in general in the liquid phase is accomplished either by applying a overpressure or keeping it below the phase transition temperature at ambient pressure in super insulated devices. (orig.)

Highly compressible and all-solid-state supercapacitors based on nanostructured composite sponge.

Science.gov (United States)

Niu, Zhiqiang; Zhou, Weiya; Chen, Xiaodong; Chen, Jun; Xie, Sishen

2015-10-21

Based on polyaniline-single-walled carbon nanotubes -sponge electrodes, highly compressible all-solid-state supercapacitors are prepared with an integrated configuration using a poly(vinyl alcohol) (PVA)/H2 SO4 gel as the electrolyte. The unique configuration enables the resultant supercapacitors to be compressed as an integrated unit arbitrarily during 60% compressible strain. Furthermore, the performance of the resultant supercapacitors is nearly unchanged even under 60% compressible strain. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrogen Station Compression, Storage, and Dispensing Technical Status and Costs: Systems Integration

Energy Technology Data Exchange (ETDEWEB)

Parks, G.; Boyd, R.; Cornish, J.; Remick, R.

2014-05-01

At the request of the U.S. Department of Energy Fuel Cell Technologies Office (FCTO), the National Renewable Energy Laboratory commissioned an independent review of hydrogen compression, storage, and dispensing (CSD) for pipeline delivery of hydrogen and forecourt hydrogen production. The panel was asked to address the (1) cost calculation methodology, (2) current cost/technical status, (3) feasibility of achieving the FCTO's 2020 CSD levelized cost targets, and to (4) suggest research areas that will help the FCTO reach its targets. As the panel neared the completion of these tasks, it was also asked to evaluate CSD costs for the delivery of hydrogen by high-pressure tube trailer. This report details these findings.

Nano-porous inorganic-organic hybrid solids: some new materials for hydrogen storage?; Les solides hybrides inorganiques-organiques nanoporeux: de nouveaux materiaux pour le stockage de l'hydrogene?

Energy Technology Data Exchange (ETDEWEB)

Serre, Ch.; Loiseau, Th.; Devic, T.; Ferey, G. [Institut Lavoisier, UMR CNRS 8180, 78 - Versailles (France); Latroche, M. [Laboratoire de Chimie Metallurgique des Terres Rares (LCMTR), UPR 209, 94 - Thiais (France); Llewellyn, Ph. [Universite de Provence, Madirel, 13 - Marseille (France); Chang, J.S. [KRICT, Daejon (Korea, Republic of)

2007-07-01

Recently have been studied chromium and aluminium carboxylates MIL-53(Cr, Al), formed from an assembly of octahedrons chains and for hybrid solids formed with octahedrons trimers (MIL-100 and MIL-101). The compounds MIL-53(Cr, Al) are microporous ({phi} {approx} 8 Angstroms, while the solids MIL-100 and MIL-101 have very large porous volumes (V {approx} 380-700000 (Angstroms){sup 3}), meso-pores ({phi} {approx} 25-34 Angstroms) and a zeolitic architecture. The resulting specific surface areas are important (between 1000 m{sup 2}.g{sup -1} for the MIL-53 solids, until 4000 m{sup 2}.g{sup -1} for the MIL-101 compound. Here is presented their hydrogen adsorption properties, at 77 K and 298 K. The hydrogen adsorption kinetics has been tested on the MIL-53(Cr) solid at 77 K. Hydrogen adsorption micro-calorimetry experiments have been carried out on these solids between 0 and 1 bar in order to obtain data on the strongest interactions between hydrogen and the porous basic structure. (O.M.)

Investigation of solid-phase hydrogenation of amino acids and peptides

International Nuclear Information System (INIS)

Zolotarev, Yu.A.; Myasoedov, N.F.; Zajtsev, D.A.; Lubnin, M.Yu.; Tatur, V.Yu.; Kozik, V.S.; Dorokhova, E.M.; Rozenberg, S.N.

1990-01-01

The possibility of synthesizing amino acids and peptides multiply labelled with tritium or deuterium by the method of solid-phase isotopic exchange with gaseous hydrogen isotopes was verified. Establishment of the isotopic hydrogen equilibrium between the gaseous phase and the solid phase formed by the amino acid molecules was found experimentally. The activation energy of the isotopic exchange is 13 kcal/mol. A mathematical model was set up for the isotopic exchange with a probable substitution of hydrogen atoms. Uniformly labelled amino acids were obtained in a high optical purity and with 80 to 90% hydrogen substitution by deuterium and tritium. Tritiated peptides were prepared in high yields at molar activities of 1.5 to 3.7 TBq/mmol. (author). 4 tabs

Compressed hydrogen fuelled vehicle at ENEA: Status and development

International Nuclear Information System (INIS)

Pede, G.; Ciancia, A.

1993-01-01

The world's 500 million road vehicles using internal combustion engines account for roughly half of global oil consumption and, in Italy, for about 50% of all nitrogen oxide and 90% of carbon monoxide emissions. In efforts to conserve petroleum reserves and reduce air pollution, research programs are being conducted to develop hydrogen fueled automotive engines. Hydrogen combustion products are carbon dioxide free, and when burned with a large excess of air, this fuel produces water vapour and only small amounts of nitrogen oxides. Hydrogen fueled vehicles can be made to operate in a dual fuel mode so as to allow the use of petrol or diesel fuel in travel over long distances. Currently, because technical and economic difficulties relevant to hydrogen fuel storage limit driving range and payload (there are bulk and weight problems in compressed gas and metal hydride storage systems, and cost problems in cryogenic storage), only limited research programs are being performed, mainly in Germany (by Mercedes Benz) and Japan. Some recent advances, however, relevant to research in gas storage and gaseous mixtures have been made by ENEA (the Italian Agency for New Technology, Energy and the Environment). This paper outlines the progress being made in ENEA's research efforts which include the development of an electronically controlled hydrogen fuel injection system prototype

Integrated processing for the treatment of materials applied to thermal compression of hydrogen

International Nuclear Information System (INIS)

Rodriguez, M.G; Esquivel, M. R

2009-01-01

In this work, AB 5 intermetallics are synthesized by low energy mechanical alloying according to: AB 5 + AB 5 = AB 5 . The obtained intermetallics are annealed at 600 oC to optimize both the microstructural and hydrogen sorption properties. Then, the material is applied to the design of schemes for thermal compression of hydrogen (TCH). These results are obtained within the frame of a research project related to Energy and Environment and focused on the replacement on fossil supply systems by a hydrogen based one. [es

Isotopic and spin-nuclear effects in solid hydrogens (Review Article)

Science.gov (United States)

Freiman, Yuri A.; Crespo, Yanier

2017-12-01

The multiple isotopic family of hydrogens (H2, HD, D2, HT, DT, T2) due to large differences in the de Boer quantum parameter and inertia moments displays a diversity of pronounced quantum isotopic solid-state effects. The homonuclear members of this family (H2, D2, T2) due to the permutation symmetry are subjects of the constraints of quantum mechanics which link the possible rotational states of these molecules to their total nuclear spin giving rise to the existence of two spin-nuclear modifications, ortho- and parahydrogens, possessing substantially different properties. Consequently, hydrogen solids present an unique opportunity for studying both isotope and spin-nuclear effects. The rotational spectra of heteronuclear hydrogens (HD, HT, DT) are free from limitations imposed by the permutation symmetry. As a result, the ground state of these species in solid state is virtually degenerate. The most dramatic consequence of this fact is an effect similar to the Pomeranchuk effect in 3He which in the case of the solid heteronuclear hydrogens manifests itself as the reentrant broken symmetry phase transitions. In this review article we discuss thermodynamic and kinetic effects pertaining to different isotopic and spin-nuclear species, as well as problems that still remain to be solved.

CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

Energy Technology Data Exchange (ETDEWEB)

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

2008-03-01

Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. 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 cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to

Compression behavior of Fe-Si-H alloys

Science.gov (United States)

Tagawa, S.; Ohta, K.; Hirose, K.; Ohishi, Y.

2015-12-01

Although the light elements in the Earth's core are still enigmatic, hydrogen has recently been receiving much attention. Planetary formation theory suggested that a large amount of water, much more than is in the oceans, could have been brought to the Earth during its accretion. Hydrogen is a strong siderophile element and could be incorporated into the core as a consequence of a reaction between water and molten iron in a magma ocean [Okuchi, 1997 Science]. Nevertheless, the effect of hydrogen on the property of iron is not well known so far. Here, we have experimentally examined the compression behavior of hcp Fe0.88Si0.12Hx (6.5 wt.% Si) at two different hydrogen concentrations (x = 0.7 and 0.9). Fe0.88Si0.12 foil was loaded into a diamond-anvil cell, and then liquid hydrogen was introduced to a sample chamber below 20 K. Hydrogenation occurred upon thermal annealing below 1500 K at 25-62 GPa, and hcp Fe0.88Si0.12Hx was obtained as a single phase. Unlike the Fe-H alloy, hydrogen did not fully occupy the octahedral sites even under hydrogen-saturated conditions. Two compression curves, one from 25 to 136 GPa, and the other from 62 to 128 GPa, were obtained at room temperature. While the effect of hydrogen on the compressibility of iron has been controversial in earlier experimental studies [Hirao et al., 2004 GRL; Pépin et al., 2014 PRL], our data indicate that the compressibility of Fe0.88Si0.12Hx alloy does not change with changing hydrogen content from x = 0 to 0.9. Such compression behavior observed is consistent with the recent ab initio calculations for hcp Fe-H alloys by Caracas[2015 GRL]. The extrapolation of present data to the outer core pressure and temperature range, assuming thermal expansivity is the same as that for iron and there is no density difference between solid and liquid, shows that the density of Fe0.88Si0.12H0.3 matches the PREM in the whole outer core within 1%.

Energy and pressure requirements for compression of swine solid fraction compost

Directory of Open Access Journals (Sweden)

Niccolò Pampuro

2013-09-01

Full Text Available The excessive amount of pig slurry spread on soil has contributed to nitrate water pollution both in surface and in ground waters, especially in areas classified as vulnerable zones to nitrate in accordance with European Regulation (91/676/CEE. Several techniques have been developed to manage livestock slurries as cheaply and conveniently as possible and to reduce potential risks of environmental pollution. Among these techniques, solid-liquid separation of slurry is a common practice in Italy. The liquid fraction can be used for irrigation and the solid fraction, after aerobic stabilization, produces an organic compost rich in humic substances. However, compost derived from swine solid fraction is a low density material (bulk density less than 500 kgm–3. This makes it costly to transport composted swine solid fraction from production sites to areas where it could be effectively utilized for value-added applications such as in soil fertilization. Densification is one possible way to enhance the storage and transportation of the compost. This study therefore investigates the effect of pressure (20- 110 MPa and pressure application time (5-120 s on the compaction characteristics of compost derived from swine solid fraction. Two different types of material have been used: composted swine solid fraction derived from mechanical separation and compost obtained by mixing the first material with wood chips. Results obtained showed that both the pressure applied and the pressure application time significantly affect the density of the compacted samples; while the specific compression energy is significantly affected only by the pressure. Best predictor equations were developed to predict compact density and the specific compression energy required by the densification process. The specific compression energy values based on the results from this study (6-32 kJkg–1 were significantly lower than the specific energy required to manufacture pellets from

Evidence for vitreous type orientational ordering in solid hydrogen and deuterium

International Nuclear Information System (INIS)

Devoret, M.

1982-09-01

This shown a new region in the concentration-temperature phase diagram for solid mixtures of ortho and para-hydrogen. This region is characterized by a vitreous type orientational, ordering, with the quadrupoles of the ortho molecules frozen in a random fashion. This new vitreous state is called a quadrupolar glass, with the degrees of freedom of quadrupolar moments frozen in solid hydrogen [fr

Nonaffine deformation under compression and decompression of a flow-stabilized solid

Science.gov (United States)

Ortiz, Carlos P.; Riehn, Robert; Daniels, Karen E.

2016-08-01

Understanding the particle-scale transition from elastic deformation to plastic flow is central to making predictions about the bulk material properties and response of disordered materials. To address this issue, we perform experiments on flow-stabilized solids composed of micron-scale spheres within a microfluidic channel, in a regime where particle inertia is negligible. Each solid heap exists within a stress field imposed by the flow, and we track the positions of particles in response to single impulses of fluid-driven compression or decompression. We find that the resulting deformation field is well-decomposed into an affine field, with a constant strain profile throughout the solid, and a non-affine field. The magnitude of this non-affine response decays with the distance from the free surface in the long-time limit, suggesting that the distance from jamming plays a significant role in controlling the length scale of plastic flow. Finally, we observe that compressive pulses create more rearrangements than decompressive pulses, an effect that we quantify using the D\\text{min}2 statistic for non-affine motion. Unexpectedly, the time scale for the compression response is shorter than for decompression at the same strain (but unequal pressure), providing insight into the coupling between deformation and cage-breaking.

Observation of a New High-Pressure Solid Phase in Dynamically Compressed Aluminum

Science.gov (United States)

Polsin, D. N.

2017-10-01

Aluminum is ideal for testing theoretical first-principles calculations because of the relative simplicity of its atomic structure. Density functional theory (DFT) calculations predict that Al transforms from an ambient-pressure, face-centered-cubic (fcc) crystal to the hexagonal close-packed (hcp) and body-centered-cubic (bcc) structures as it is compressed. Laser-driven experiments performed at the University of Rochester's Laboratory for Laser Energetics and the National Ignition Facility (NIF) ramp compressed Al samples to pressures up to 540 GPa without melting. Nanosecond in-situ x-ray diffraction was used to directly measure the crystal structure at pressures where the solid-solid phase transformations of Al are predicted to occur. Laser velocimetry provided the pressure in the Al. Our results show clear evidence of the fcc-hcp and hpc-bcc transformations at 216 +/- 9 GPa and 321 +/- 12 GPa, respectively. This is the first experimental in-situ observation of the bcc phase in compressed Al and a confirmation of the fcc-hcp transition previously observed under static compression at 217 GPa. The observations indicate these solid-solid phase transitions occur on the order of tens of nanoseconds time scales. In the fcc-hcp transition we find the original texture of the sample is preserved; however, the hcp-bcc transition diminishes that texture producing a structure that is more polycrystalline. The importance of this dynamic is discussed. The NIF results are the first demonstration of x-ray diffraction measurements at two different pressures in a single laser shot. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Thermodynamic Analysis of Three Compressed Air Energy Storage Systems: Conventional, Adiabatic, and Hydrogen-Fueled

Directory of Open Access Journals (Sweden)

Hossein Safaei

2017-07-01

Full Text Available We present analyses of three families of compressed air energy storage (CAES systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latter two methods involve no fossil fuel combustion. We modeled both a low-temperature and a high-temperature electrolysis process for hydrogen production. Adiabatic CAES (A-CAES with physical storage of heat is the most efficient option with an exergy efficiency of 69.5% for energy storage. The exergy efficiency of the conventional CAES system is estimated to be 54.3%. Both high-temperature and low-temperature electrolysis CAES systems result in similar exergy efficiencies (35.6% and 34.2%, partly due to low efficiency of the electrolyzer cell. CAES with high-temperature electrolysis has the highest energy storage density (7.9 kWh per m3 of air storage volume, followed by A-CAES (5.2 kWh/m3. Conventional CAES and CAES with low-temperature electrolysis have similar energy densities of 3.1 kWh/m3.

NATO Advanced Study Institute on Hydrogen in Disordered and Amorphous Solids

CERN Document Server

Bowman, Robert

1986-01-01

This is the second volume in the NATO ASI series dealing with the topic of hydrogen in solids. The first (V. B76, Metal Hydrides) appeared five years ago and focussed primarily on crystalline phases of hydrided metallic systems. In the intervening period, the amorphous solid state has become an area of intense research activity, encompassing both metallic and non-metallic, e.g. semiconducting, systems. At the same time the problem of storage of hydrogen, which motivated the first ASI, continues to be important. In the case of metallic systems, there were early indications that metallic glasses and disordered alloys may be more corrosion resistant, less susceptible to embrittlement by hydrogen and have a higher hydrogen mobility than ordered metals or intermetallics. All of these properties are desirable for hydrogen storage. Subsequent research has shown that thermodynamic instability is a severe problem in many amorphous metal hydrides. The present ASI has provided an appropriate forum to focus on these issu...

Solid - solid and solid - liquid phase transitions of iron and iron alloys under laser shock compression

Science.gov (United States)

Harmand, M.; Krygier, A.; Appel, K.; Galtier, E.; Hartley, N.; Konopkova, Z.; Lee, H. J.; McBride, E. E.; Miyanishi, K.; Nagler, B.; Nemausat, R.; Vinci, T.; Zhu, D.; Ozaki, N.; Fiquet, G.

2017-12-01

An accurate knowledge of the properties of iron and iron alloys at high pressures and temperatures is crucial for understanding and modelling planetary interiors. While Earth-size and Super-Earth Exoplanets are being discovered in increasingly large numbers, access to detailed information on liquid properties, melting curves and even solid phases of iron and iron at the pressures and temperatures of their interiors is still strongly limited. In this context, XFEL sources coupled with high-energy lasers afford unique opportunities to measure microscopic structural properties at far extreme conditions. Also the achievable time resolution allows the shock history and phase transition mechanisms to be followed during laser compression, improving our understanding of the high pressure and high strain experiments. Here we present recent studies devoted to investigate the solid-solid and solid-liquid transition in laser-shocked iron and iron alloys (Fe-Si, Fe-C and Fe-O alloys) using X-ray diffraction and X-ray diffuse scattering. Experiment were performed at the MEC end-station of the LCLS facility at SLAC (USA). Detection of the diffuse scattering allowed the identification of the first liquid peak position along the Hugoniot, up to 4 Mbar. The time resolution shows ultrafast (between several tens and several hundreds of picoseconds) solid-solid and solid-liquid phase transitions. Future developments at XFEL facilities will enable detailed studies of the solid and liquid structures of iron and iron alloys as well as out-of-Hugoniot studies.

Development of Advanced Small Hydrogen Engines

Energy Technology Data Exchange (ETDEWEB)

Sapru, Krishna; Tan, Zhaosheng; Chao, Ben

2010-09-30

The main objective of the project is to develop advanced, low cost conversions of small (< 25 hp) gasoline internal combustion engines (ICEs) to run on hydrogen fuel while maintaining the same performance and durability. This final technical report summarizes the results of i) the details of the conversion of several small gasoline ICEs to run on hydrogen, ii) the durability test of a converted hydrogen engine and iii) the demonstration of a prototype bundled canister solid hydrogen storage system. Peak power of the hydrogen engine achieves 60% of the power output of the gasoline counterpart. The efforts to boost the engine power with various options including installing the over-sized turbocharger, retrofit of custom-made pistons with high compression ratio, an advanced ignition system, and various types of fuel injection systems are not realized. A converted Honda GC160 engine with ACS system to run with hydrogen fuel is successful. Total accumulative runtime is 785 hours. A prototype bundled canister solid hydrogen storage system having nominal capacity of 1.2 kg is designed, constructed and demonstrated. It is capable of supporting a wide range of output load of a hydrogen generator.

Review of Solid State Hydrogen Storage Methods Adopting Different Kinds of Novel Materials

Directory of Open Access Journals (Sweden)

Renju Zacharia

2015-01-01

Full Text Available Overview of advances in the technology of solid state hydrogen storage methods applying different kinds of novel materials is provided. Metallic and intermetallic hydrides, complex chemical hydride, nanostructured carbon materials, metal-doped carbon nanotubes, metal-organic frameworks (MOFs, metal-doped metal organic frameworks, covalent organic frameworks (COFs, and clathrates solid state hydrogen storage techniques are discussed. The studies on their hydrogen storage properties are in progress towards positive direction. Nevertheless, it is believed that these novel materials will offer far-reaching solutions to the onboard hydrogen storage problems in near future. The review begins with the deficiencies of current energy economy and discusses the various aspects of implementation of hydrogen energy based economy.

Measurement of scattering cross sections of liquid and solid hydrogen, deuterium and deuterium hydride for thermal neutrons

International Nuclear Information System (INIS)

Seiffert, W.D.

1984-01-01

The scattering cross sections for liquid and solid normal hydrogen, para-hydrogen, deuterium and deuterium hydride were measured for thermal neutrons at various temperatures. Solid samples of para-hydrogen exhibit distinct Bragg scattering. Liquid samples of deuterium and para-hydrogen also exhibit distinct coherence phenomena, which is indicative of strong local ordering of the molecules. In para-hydrogen and deuterium hydride, the threshold for scattering with excitation of rotations is distinctly visible. The positions of the thresholds show that the molecules in liquid hydrogen are not unhindered in their movement. After the beginning of the rotational excitation the scattering cross sections of liquid and solid para-hydrogen have different shapes which is to be explained by the differences in the dynamics of the liquid and the solid specimen. 22 references

Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

International Nuclear Information System (INIS)

Oda, Y.; Azuma, K.; Onozuka, M.; Kasai, S.; Hasegawa, K.

1995-01-01

Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.)

Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

Energy Technology Data Exchange (ETDEWEB)

Oda, Y. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Azuma, K. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Onozuka, M. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Kasai, S. [Japan Atomic Energy Research Inst., Ibaraki (Japan); Hasegawa, K. [Japan Atomic Energy Research Inst., Ibaraki (Japan)

1995-12-31

Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.).

FINAL REPORT: Room Temperature Hydrogen Storage in Nano-Confined Liquids

Energy Technology Data Exchange (ETDEWEB)

VAJO, JOHN

2014-06-12

DOE continues to seek solid-state hydrogen storage materials with hydrogen densities of ≥6 wt% and ≥50 g/L that can deliver hydrogen and be recharged at room temperature and moderate pressures enabling widespread use in transportation applications. Meanwhile, development including vehicle engineering and delivery infrastructure continues for compressed-gas hydrogen storage systems. Although compressed gas storage avoids the materials-based issues associated with solid-state storage, achieving acceptable volumetric densities has been a persistent challenge. This project examined the possibility of developing storage materials that would be compatible with compressed gas storage technology based on enhanced hydrogen solubility in nano-confined liquid solvents. These materials would store hydrogen in molecular form eliminating many limitations of current solid-state materials while increasing the volumetric capacity of compressed hydrogen storage vessels. Experimental methods were developed to study hydrogen solubility in nano-confined liquids. These methods included 1) fabrication of composites comprised of volatile liquid solvents for hydrogen confined within the nano-sized pore volume of nanoporous scaffolds and 2) measuring the hydrogen uptake capacity of these composites without altering the composite composition. The hydrogen storage capacities of these nano-confined solvent/scaffold composites were compared with bulk solvents and with empty scaffolds. The solvents and scaffolds were varied to optimize the enhancement in hydrogen solubility that accompanies confinement of the solvent. In addition, computational simulations were performed to study the molecular-scale structure of liquid solvent when confined within an atomically realistic nano-sized pore of a model scaffold. Confined solvent was compared with similar simulations of bulk solvent. The results from the simulations were used to formulate a mechanism for the enhanced solubility and to guide the

Solid hydrogen pellet injection into the ORMAK Tokamak

International Nuclear Information System (INIS)

Foster, C.A.; Colchin, R.J.; Milora, S.L.; Kim, K.; Turnbull, R.J.

1977-06-01

Solid hydrogen spheres were injected into the ORMAK tokamak as a test of pellet refueling for tokamak fusion reactors. Pellets 70 μm and 210 μm in diameter were injected with speeds of 91 m/sec and 100 m/sec, respectively. Each of the 210-μm pellets added about 1% to the number of particles contained in the plasma. Excited neutrals, ablated from these hydrogen spheres, emitted light which was monitored either by a photomultiplier or by a high speed framing camera. From these light signals it was possible to measure pellet lifetimes, ablation rates, and the spatial distribution of hydrogen atoms in the ablation clouds. The average measured lifetime of the 70-μm pellets was 422 μsec, and the 210-μm spheres lasted 880 μsec under bombardment by the plasma. These lifetimes and measured ablation rates are in good agreement with a theoretical model which takes into account shielding of plasma electrons by hydrogen atoms ablated from spherical hydrogen ice

Operation of the cryotron relaxation generator in solid argon and hydrogen

International Nuclear Information System (INIS)

Rakhubvsky, V.A.

2008-01-01

The research results of the cryotron relaxation generator (CRG) operation in solid argon, normal hydrogen and parahydrogen have been given. The frequency transition times for CRG at different values of cooling the solid gas have been measured

Characterization of the constitutive behavior of municipal solid waste considering particle compressibility.

Science.gov (United States)

Lü, Xilin; Zhai, Xinle; Huang, Maosong

2017-11-01

This paper presents a characterization of the mechanical behavior of municipal solid waste (MSW) under consolidated drained and undrained triaxial conditions. The constitutive model was established based on a deviatoric hardening plasticity model. A power form function and incremental hyperbolic form function were proposed to describe the shear strength and the hardening role of MSW. The stress ratio that corresponds to the zero dilatancy was not fixed but depended on mean stress, making the Rowe's rule be able to describe the stress-dilatancy of MSW. A pore water pressure reduction coefficient, which attributed to the compressibility of a particle and the solid matrix, was introduced to the effective stress formulation to modify the Terzaghi's principle. The effects of particle compressibility and solid matrix compressibility on the undrained behavior of MSW were analyzed by parametric analysis, and the changing characteristic of stress-path, stress-strain, and pore-water pressure were obtained. The applicability of the proposed model on MSW under drained and undrained conditions was verified by model predictions of three triaxial tests. The comparison between model simulations and experiments indicated that the proposed model can capture the observed different characteristics of MSW response from normal soil, such as nonlinear shear strength, pressure dependent stress dilatancy, and the reduced value of pore water pressure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solid solutions of hydrogen uranyl phosphate and hydrogen uranyl arsenate. A family of luminescent, lamellar hosts

International Nuclear Information System (INIS)

Dorhout, P.K.; Rosenthal, G.L.; Ellis, A.B.

1988-01-01

Hydrogen uranyl phosphate, HUO 2 PO 4 x 4H 2 O (HUP), and hydrogen uranyl arsenate, HUO 2 AsO 4 x 4H 2 O (HUAs), form solid solutions of composition HUO 2 (PO 4 ) 1-x (AsO 4 )x (HUPAs), representing a family of lamellar, luminescent solids that can serve as hosts for intercalation chemistry. The solids are prepared by aqueous precipitation reactions from uranyl nitrate and mixtures of phosphoric and arsenic acids; thermogravimetric analysis indicates that the phases are tetrahydrates, like HUP and HUAs. Powder x-ray diffraction data reveal the HUPAs solids to be single phases whose lattice constants increase with X, in rough accord with Vegard's law Spectral shifts observed for the HUPAs samples. Emission from the solids is efficient (quantum yields of ∼ 0.2) and long-lived (lifetimes of ∼ 150 μs), although the measured values are uniformly smaller than those of HUP and HUAs; unimolecular radiative and nonradiative rate constants for excited-state decay of ∼ 1500 and 5000 s -1 , respectively, have been calculated for the compounds. 18 refs., 5 figs., 2 tabs

Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

International Nuclear Information System (INIS)

Schou, J.; Soerensen, H.; Andersen, H.H.; Nielsen, M.; Rune, J.

1984-01-01

Ranges of 1.3-3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen. The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees with that previously found for solid nitrogen. (orig.)

Thin-thick hydrogen target for nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Gheller, J.-M.; Juster, F.-P.; Authelet, G. [CEA Saclay, Irfu/SACM, F-91191 Gif-Sur-Yvette cedex (France); Vinyar, I. [PELIN Limited Liability Company 27 A, Gzhatskaya Str, office 103 St. Petersbourg 195220 (Russian Federation); Relland, J. [CEA Saclay, Irfu/SIS, F-91191 Gif-Sur-Yvette cedex (France); Commeaux, C. [Institut de Physique Nucléaire, campus Universitaire-Bat 103, 91406 Orsay cedex (France)

2014-01-29

In spectroscopic studies of unstable nuclei, hydrogen targets are of key importance. The CHyMENE Project aims to provide to the nuclear physics community a thin and pure solid windowless hydrogen or deuterium target. CHyMENE project must respond to this request for the production of solid Hydrogen. The solid hydrogen target is produced in a continuous flow (1 cm/s) by an extrusion technique (developed with the PELIN laboratory) in a vacuum chamber. The shape of the target is determined by the design of the nozzle at the extrusion process. For the purpose, the choice is a rectangular shape with a width of 10 mm and a thickness in the range of 30-50 microns necessary for the physics objectives. The cryostat is equipped with a GM Cryocooler with sufficient power for the solidification of the hydrogen in the lower portion of the extruder. In the higher part of the cryostat, the hydrogen gas is first liquefied and partially solidified. It is then compressed at 100 bars in the cooled extruder before expulsion of the film through the nozzle at the center of the reaction vacuum chamber. After the previous step, the solid hydrogen ribbon falls by gravity into a dedicated chamber where it sublimes and the gas is pumped and evacuated in a exhaust line. This paper deals with the design of the cryostat with its equipment, with the sizing of the thermal bridge (Aluminum and copper), with the results regarding the contact resistance as well as with the vacuum computations of the reaction and recovery hydrogen gas chambers.

Emission of muonic hydrogen isotopes from solid hydrogen layers into vacuum

International Nuclear Information System (INIS)

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

1989-10-01

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

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

International Nuclear Information System (INIS)

Sawada, H.; Lee, S.; Nagatomo, H.; Arikawa, Y.; Nishimura, H.; Ueda, T.; Shigemori, K.; Fujioka, S.; Shiroto, T.; Ohnishi, N.; Sunahara, A.; Beg, F. N.; Theobald, W.; Pérez, F.; Patel, P. K.

2016-01-01

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm"2. The temporal evolution of the experimental and simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

Energy Technology Data Exchange (ETDEWEB)

Sawada, H. [Department of Physics, University of Nevada Reno, Reno, Nevada 89557 (United States); Lee, S.; Nagatomo, H.; Arikawa, Y.; Nishimura, H.; Ueda, T.; Shigemori, K.; Fujioka, S. [Institute of Laser Engineering, Osaka University, Suita, Osaka (Japan); Shiroto, T.; Ohnishi, N. [Department of Aerospace Engineering, Tohoku University, Sendai, Miyagi (Japan); Sunahara, A. [Institute of Laser Technology, Nishi-ku, Osaka (Japan); Beg, F. N. [University of California San Diego, La Jolla, California 92093 (United States); Theobald, W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Pérez, F. [LULI, Ecole Polytechnique, Palaiseau, Cedex (France); Patel, P. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm{sup 2}. The temporal evolution of the experimental and simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.

Permeability and compression characteristics of municipal solid waste samples

Science.gov (United States)

Durmusoglu, Ertan; Sanchez, Itza M.; Corapcioglu, M. Yavuz

2006-08-01

Four series of laboratory tests were conducted to evaluate the permeability and compression characteristics of municipal solid waste (MSW) samples. While the two series of tests were conducted using a conventional small-scale consolidometer, the two others were conducted in a large-scale consolidometer specially constructed for this study. In each consolidometer, the MSW samples were tested at two different moisture contents, i.e., original moisture content and field capacity. A scale effect between the two consolidometers with different sizes was investigated. The tests were carried out on samples reconsolidated to pressures of 123, 246, and 369 kPa. Time settlement data gathered from each load increment were employed to plot strain versus log-time graphs. The data acquired from the compression tests were used to back calculate primary and secondary compression indices. The consolidometers were later adapted for permeability experiments. The values of indices and the coefficient of compressibility for the MSW samples tested were within a relatively narrow range despite the size of the consolidometer and the different moisture contents of the specimens tested. The values of the coefficient of permeability were within a band of two orders of magnitude (10-6-10-4 m/s). The data presented in this paper agreed very well with the data reported by previous researchers. It was concluded that the scale effect in the compression behavior was significant. However, there was usually no linear relationship between the results obtained in the tests.

Numerically stable fluid–structure interactions between compressible flow and solid structures

KAUST Repository

Grétarsson, Jón Tómas

2011-04-01

We propose a novel method to implicitly two-way couple Eulerian compressible flow to volumetric Lagrangian solids. The method works for both deformable and rigid solids and for arbitrary equations of state. The method exploits the formulation of [11] which solves compressible fluid in a semi-implicit manner, solving for the advection part explicitly and then correcting the intermediate state to time tn+1 using an implicit pressure, obtained by solving a modified Poisson system. Similar to previous fluid-structure interaction methods, we apply pressure forces to the solid and enforce a velocity boundary condition on the fluid in order to satisfy a no-slip constraint. Unlike previous methods, however, we apply these coupled interactions implicitly by adding the constraint to the pressure system and combining it with any implicit solid forces in order to obtain a strongly coupled, symmetric indefinite system (similar to [17], which only handles incompressible flow). We also show that, under a few reasonable assumptions, this system can be made symmetric positive-definite by following the methodology of [16]. Because our method handles the fluid-structure interactions implicitly, we avoid introducing any new time step restrictions and obtain stable results even for high density-to-mass ratios, where explicit methods struggle or fail. We exactly conserve momentum and kinetic energy (thermal fluid-structure interactions are not considered) at the fluid-structure interface, and hence naturally handle highly non-linear phenomenon such as shocks, contacts and rarefactions. © 2011 Elsevier Inc.

Hydrogen storage in TiCr1.2(FeV)x BCC solid solutions

International Nuclear Information System (INIS)

Santos, Sydney F.; Huot, Jacques

2009-01-01

The Ti-V-based BCC solid solutions have been considered attractive candidates for hydrogen storage due to their relatively large hydrogen absorbing capacities near room temperature. In spite of this, improvements of some issues should be achieved to allow the technological applications of these alloys. Higher reversible hydrogen storage capacity, decreasing the hysteresis of PCI curves, and decrease in the cost of the raw materials are needed. In the case of vanadium-rich BCC solid solutions, which usually have large hydrogen storage capacities, the search for raw materials with lower cost is mandatory since pure vanadium is quite expensive. Recently, the substitutions of vanadium in these alloys have been tried and some interesting results were achieved by replacing vanadium by commercial ferrovanadium (FeV) alloy. In the present work, this approach was also adopted and TiCr 1.2 (FeV) x alloy series was investigated. The XRD patterns showed the co-existence of a BCC solid solution and a C14 Laves phase in these alloys. SEM analysis showed the alloys consisted of dendritic microstructure and C14 colonies. The amount of C14 phase increases when the amount of (FeV) decreases in these alloys. Concerning the hydrogen storage, the best results were obtained for the TiCr 1.2 (FeV) 0.4 alloy, which achieved 2.79 mass% of hydrogen storage capacity and 1.36 mass% of reversible hydrogen storage capacity

Metallic hydrogen research

International Nuclear Information System (INIS)

Burgess, T.J.; Hawke, R.S.

1978-01-01

Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm 3 and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures

Hydrogen and methane production from household solid waste in the two-stage fermentation process

DEFF Research Database (Denmark)

Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

2006-01-01

A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved....

Matrix effect on hydrogen-atom tunneling of organic molecules in cryogenic solids

International Nuclear Information System (INIS)

Ichikawa, Tsuneki

2000-01-01

Although the tunneling of atoms through potential energy barriers separating the reactant and reaction systems is not paid much attention in organic reactions, this plays an important role in reactions including the transfer of light atoms. Atomic tunneling is especially important for chemical reactions at low temperatures, since the thermal activation of reactant systems is very slow process in comparison with the tunneling. One of the typical reactions of atomic tunneling is hydrogen-atom abstraction from alkanes in cryogenic solids exposed to high-energy radiation. Irradiation of alkane molecules causes the homolytic cleavage of C-H bonds, which results in the pairwise formation of free hydrogen atoms and organic free radicals. Since the activation energies for the abstraction of hydrogen atoms from alkane molecules by free hydrogen atoms are higher than 5 kcal/mol, the lifetime of free hydrogen atoms at 77 K is estimated from the Arrhenius equation of k=vexp(-E a /RT) to be longer than 10 hrs. However, except for solid methane, free hydrogen atoms immediately convert to alkyl radicals even at 4.2 K by hydrogen-atom tunneling from alkane molecules to the free hydrogen atoms. The rate of hydrogen atom tunneling does not necessary increase with decreasing activation energy or the peak height of the potential energy barrier preventing the tunneling. Although the activation energy is the lowest at the tertiary carbon of alkanes, hydrogen atom tunneling from branched alkanes with tertiary carbon at the antepenultimate position of the carbon skeleton is the fastest at the secondary penultimate carbon. Based on our experimental results, we have proposed that the peculiarity of the hydrogen-atom abstraction in cryogenic solids comes from the steric hindrance by matrix molecules to the deformation of alkane molecules from the initial sp 3 to the final sp 2 configurations. The steric hindrance causes the increase of the height of the potential energy barrier for the

Calculation of hydrogen diffusion toward a crack in a stressed solid

International Nuclear Information System (INIS)

1976-10-01

A set of eigensolutions is derived for use in expanding the steady-state concentration of hydrogen diffusing through a region bounded by two cylinders centred on an infinite crack in a stressed solid. Comparison is made with some experimental values of the hydrogen-induced crack-propagation velocity within the framework of the theory of Dutton and Puls. (author)

Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage

Energy Technology Data Exchange (ETDEWEB)

Pfeifer, Peter [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Gillespie, Andrew [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Stalla, David [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Dohnke, Elmar [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics

2017-02-20

The purpose of the project “Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage” is the development of materials that store hydrogen (H₂) by adsorption in quantities and at conditions that outperform current compressed-gas H₂ storage systems for electric power generation from hydrogen fuel cells (HFCs). Prominent areas of interest for HFCs are light-duty vehicles (“hydrogen cars”) and replacement of batteries with HFC systems in a wide spectrum of applications, ranging from forklifts to unmanned areal vehicles to portable power sources. State-of-the-art compressed H₂ tanks operate at pressures between 350 and 700 bar at ambient temperature and store 3-4 percent of H₂ by weight (wt%) and less than 25 grams of H₂ per liter (g/L) of tank volume. Thus, the purpose of the project is to engineer adsorbents that achieve storage capacities better than compressed H₂ at pressures less than 350 bar. Adsorption holds H₂ molecules as a high-density film on the surface of a solid at low pressure, by virtue of attractive surface-gas interactions. At a given pressure, the density of the adsorbed film is the higher the stronger the binding of the molecules to the surface is (high binding energies). Thus, critical for high storage capacities are high surface areas, high binding energies, and low void fractions (high void fractions, such as in interstitial space between adsorbent particles, “waste” storage volume by holding hydrogen as non-adsorbed gas). Coexistence of high surface area and low void fraction makes the ideal adsorbent a nanoporous monolith, with pores wide enough to hold high-density hydrogen films, narrow enough to minimize storage as non-adsorbed gas, and thin walls between pores to minimize the volume occupied by solid instead of hydrogen. A monolith can be machined to fit into a rectangular tank (low pressure, conformable tank), cylindrical tank

Synthesis and stability of hydrogen selenide compounds at high pressure

Energy Technology Data Exchange (ETDEWEB)

Pace, Edward J.; Binns, Jack; Alvarez, Miriam Pena; Dalladay-Simpson, Philip; Gregoryanz, Eugene; Howie, Ross T. (Edinburgh); (CHPSTAR- China)

2017-11-14

The observation of high-temperature superconductivity in hydride sulfide (H2S) at high pressures has generated considerable interest in compressed hydrogen-rich compounds. High-pressure hydrogen selenide (H2Se) has also been predicted to be superconducting at high temperatures; however, its behaviour and stability upon compression remains unknown. In this study, we synthesize H2Se in situ from elemental Se and molecular H2 at pressures of 0.4 GPa and temperatures of 473 K. On compression at 300 K, we observe the high-pressure solid phase sequence (I-I'-IV) of H2Se through Raman spectroscopy and x-ray diffraction measurements, before dissociation into its constituent elements. Through the compression of H2Se in H2 media, we also observe the formation of a host-guest structure, (H2Se)2H2, which is stable at the same conditions as H2Se, with respect to decomposition. These measurements show that the behaviour of H2Se is remarkably similar to that of H2S and provides further understanding of the hydrogen chalcogenides under pressure.

Prediction of the compression ratio for municipal solid waste using decision tree.

Science.gov (United States)

Heshmati R, Ali Akbar; Mokhtari, Maryam; Shakiba Rad, Saeed

2014-01-01

The compression ratio of municipal solid waste (MSW) is an essential parameter for evaluation of waste settlement and landfill design. However, no appropriate model has been proposed to estimate the waste compression ratio so far. In this study, a decision tree method was utilized to predict the waste compression ratio (C'c). The tree was constructed using Quinlan's M5 algorithm. A reliable database retrieved from the literature was used to develop a practical model that relates C'c to waste composition and properties, including dry density, dry weight water content, and percentage of biodegradable organic waste using the decision tree method. The performance of the developed model was examined in terms of different statistical criteria, including correlation coefficient, root mean squared error, mean absolute error and mean bias error, recommended by researchers. The obtained results demonstrate that the suggested model is able to evaluate the compression ratio of MSW effectively.

Compact hydrogen production systems for solid polymer fuel cells

Science.gov (United States)

Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

Experimental investigation of hydrogen energy share improvement in a compression ignition engine using water injection and compression ratio reduction

International Nuclear Information System (INIS)

Chintala, V.; Subramanian, K.A.

2016-01-01

Highlights: • Energy efficiency (EE) increased with increase in hydrogen (H_2) energy share. • H_2 energy share increased from 19% to 79% with combined CR reduction and water. • In-cylinder temperature decreased significantly with water addition and CR reduction. • HC, CO, smoke and NO_x emissions with water and CR are lower than base diesel. - Abstract: This study deals with the effect of water addition on enhancement of maximum hydrogen energy share in a compression ignition engine (7.4 kW rated power at 1500 rpm) under dual fuel mode. The specific water consumption (SWC) was varied from 130 to 480 g/kW h in step of 70 g/kW h using manifold and port injection methods. Subsequently, the combined effect of reduction of compression ratio (CR) of the engine (from 19.5:1 (base) to 16.5:1 and 15.4:1) along with water addition on further enhancement of hydrogen energy share is investigated. The hydrogen energy share was limited to 18.8% with conventional dual fuel mode due to knocking. However, the energy share increased to 66.5% with water addition (maximum SWC: 480 g/kW h), and 79% with combined control strategies (SWC of 340 g/kW h and CR reduction to 16.5:1). Thermal efficiency of the engine under water added dual fuel mode is higher than base diesel mode (single fuel mode), but it is lower than the conventional dual fuel mode without water. The efficiency of the engine with reduced CR and water addition is lower than the conventional dual fuel mode, however at the CR of 16.5:1 and SWC of 340 g/kW h, the efficiency is comparable with base diesel mode efficiency. Hydrocarbon, carbon monoxide, smoke, and oxides of nitrogen emissions of the engine with water addition (340 g/kW h) and CR reduction (to 16.5:1) decreased significantly as compared to base diesel mode, but slightly higher than conventional dual fuel mode.

Pressure hydrogenation of solid carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Pier, M; Kroenig, W

1942-09-28

A process is described for the continuous pressure hydrogenation of solid, nonfusible carbonaceous material, such as coal, oil shale, or peat, in a pasted condition, characterized in that the charge is heated in a known way under pressure, together with water, nearly to the reaction temperature, then it is led into a pressure vessel, whose volume amounts to 20 to 40% of the usual reaction space without any change at the same temperature, and the charge then goes through the reaction vessel, after which its temperature is raised to the reaction height.

Determination of the mechanical properties of solid and cellular polymeric dosage forms by diametral compression.

Science.gov (United States)

Blaesi, Aron H; Saka, Nannaji

2016-07-25

At present, the immediate-release solid dosage forms, such as the oral tablets and capsules, are granular solids. They release drug rapidly and have adequate mechanical properties, but their manufacture is fraught with difficulties inherent in processing particulate matter. Such difficulties, however, could be overcome by liquid-based processing. Therefore, we have recently introduced polymeric cellular (i.e., highly porous) dosage forms prepared from a melt process. Experiments have shown that upon immersion in a dissolution medium, the cellular dosage forms with polyethylene glycol (PEG) as excipient and with predominantly open-cell topology disintegrate by exfoliation, thus enabling rapid drug release. If the volume fraction of voids of the open-cell structures is too large, however, their mechanical strength is adversely affected. At present, the common method for determining the tensile strength of brittle, solid dosage forms (such as select granular forms) is the diametral compression test. In this study, the theory of diametral compression is first refined to demonstrate that the relevant mechanical properties of ductile and cellular solids (i.e., the elastic modulus and the yield strength) can also be extracted from this test. Diametral compression experiments are then conducted on PEG-based solid and cellular dosage forms. It is found that the elastic modulus and yield strength of the open-cell structures are about an order of magnitude smaller than those of the non-porous solids, but still are substantially greater than the stiffness and strength requirements for handling the dosage forms manually. This work thus demonstrates that melt-processed polymeric cellular dosage forms that release drug rapidly can be designed and manufactured to have adequate mechanical properties. Copyright © 2016. Published by Elsevier B.V.

Sputtering of solid nitrogen and oxygen by keV hydrogen ions

DEFF Research Database (Denmark)

Ellegaard, O.; Schou, Jørgen; Stenum, B.

1994-01-01

Electronic sputtering of solid nitrogen and oxygen by keV hydrogen ions has been studied at two low-temperature setups. The yield of the sputtered particles has been determined in the energy regime 4-10 keV for H+, H-2+ and H-3+ ions. The yield for oxygen is more than a factor of two larger than...... that for nitrogen. The energy distributions of the sputtered N2 and O2 molecules were measured for hydrogen ions in this energy regime as well. The yields from both solids turn out to depend on the sum of the stopping power of all atoms in the ion. The yield increases as a quadratic function of the stopping power...

Performance Improvement of V-Fe-Cr-Ti Solid State Hydrogen Storage Materials in Impure Hydrogen Gas.

Science.gov (United States)

Ulmer, Ulrich; Oertel, Daria; Diemant, Thomas; Bonatto Minella, Christian; Bergfeldt, Thomas; Dittmeyer, Roland; Behm, R Jürgen; Fichtner, Maximilian

2018-01-17

Two approaches of engineering surface structures of V-Ti-based solid solution hydrogen storage alloys are presented, which enable improved tolerance toward gaseous oxygen (O 2 ) impurities in hydrogen (H 2 ) gas. Surface modification is achieved through engineering lanthanum (La)- or nickel (Ni)-rich surface layers with enhanced cyclic stability in an H 2 /O 2 mixture. The formation of a Ni-rich surface layer does not improve the cycling stability in H 2 /O 2 mixtures. Mischmetal (Mm, a mixture of La and Ce) agglomerates are observed within the bulk and surface of the alloy when small amounts of this material are added during arc melting synthesis. These agglomerates provide hydrogen-transparent diffusion pathways into the bulk of the V-Ti-Cr-Fe hydrogen storage alloy when the remaining oxidized surface is already nontransparent for hydrogen. Thus, the cycling stability of the alloy is improved in an O 2 -containing hydrogen environment as compared to the same alloy without addition of Mm. The obtained surface-engineered storage material still absorbs hydrogen after 20 cycles in a hydrogen-oxygen mixture, while the original material is already deactivated after 4 cycles.

Active Edge Sites Engineering in Nickel Cobalt Selenide Solid Solutions for Highly Efficient Hydrogen Evolution

KAUST Repository

Xia, Chuan

2017-01-06

An effective multifaceted strategy is demonstrated to increase active edge site concentration in NiCoSe solid solutions prepared by in situ selenization process of nickel cobalt precursor. The simultaneous control of surface, phase, and morphology result in as-prepared ternary solid solution with extremely high electrochemically active surface area (C = 197 mF cm), suggesting significant exposure of active sites in this ternary compound. Coupled with metallic-like electrical conductivity and lower free energy for atomic hydrogen adsorption in NiCoSe, identified by temperature-dependent conductivities and density functional theory calculations, the authors have achieved unprecedented fast hydrogen evolution kinetics, approaching that of Pt. Specifically, the NiCoSe solid solutions show a low overpotential of 65 mV at -10 mV cm, with onset potential of mere 18 mV, an impressive small Tafel slope of 35 mV dec, and a large exchange current density of 184 μA cm in acidic electrolyte. Further, it is shown that the as-prepared NiCoSe solid solution not only works very well in acidic electrolyte but also delivers exceptional hydrogen evolution reaction (HER) performance in alkaline media. The outstanding HER performance makes this solid solution a promising candidate for mass hydrogen production.

Thermal diffusion of hydrogen in zircaloy-2 containing hydrogen beyond terminal solid solubility

International Nuclear Information System (INIS)

Maki, Hideo; Sato, Masao.

1975-01-01

The thermal diffusion of hydrogen is one of causes of uneven hydride precipitation in zircaloy fuel cladding tubes that are used in water reactors. In the diffusion model of hydrogen in zircaloy, the effects of the hydride on the diffusibility of hydrogen has been regarded as negligibly small in comparison with that of hydrogen dissolved in the matrix. Contrary to the indications given by this model, phenomena are often encountered that cannot be explained unless hydride platelets have considerable ostensible diffusibility in zircaloy. In order to determine quantitatively the diffusion characteristics of hydrogen in zircaloy, a thermal diffusion experiment was performed with zircaloy-2 fuel cladding tubes containing hydrogen beyond the terminal solid solubility. In this experiment, a temperature difference of 20 0 --30 0 C was applied between the inside and outside surfaces of the specimen in a thermal simulator. To explain the experimental results, a modified diffusion model is presented, in which the effects of stress are introduced into Markowitz's model with the diffusion of hydrogen in the hydride taken into account. The diffusion equation derived from this model can be written in a form that ostensibly represents direct diffusion of hydride in zircaloy. The apparent diffusion characteristics of the hydride at around 300 0 C are Dsub(p)=2.3x10 5 exp(-32,000/RT), (where R:gas constant, T:temperature) and the apparent heat of transport Qsub(p) =-60,000 cal/mol. The modified diffusion model well explains the experimental results in such respects as reaches a steady state after several hours. (auth.)

Ultrapure hydrogen thermal compressor based on metal hydrides for fuel cells and hybrid vehicles

International Nuclear Information System (INIS)

Almasan, V.; Biris, A.; Coldea, I.; Lupu, D.; Misan, I.; Popeneciu, G.; Ardelean, O.

2007-01-01

Full text: In hydrogen economy, efficient compressors are indispensable elements in the storage, transport and distribution of the produced hydrogen. Energetic efficient technologies can contribute to H 2 pipelines transport to the point of use and to distribute H 2 by refuelling stations. Characteristic for metal hydrides systems is the wide area of possibilities to absorb hydrogen at low pressure from any source of hydrogen, to store and deliver it hydrogen at high pressure (compression ratio more than 30). On the basis of innovative concepts and advanced materials for H 2 storage/compression (and fast thermal transfer), a fast mass (H 2 ) and heat transfer unit will be developed suitable to be integrated in a 3 stage thermal compressor. Metal hydrides used for a three stage hydrogen compression system must have different equilibrium pressures, namely: for stage 1, low pressure H 2 absorption and resistant to poisoning with impurities of hydrogen, for stage 2, medium pressure H 2 absorption and for stage 3, high pressure hydrogen delivery (120 bar). In the case of compression device based on metallic hydrides the most important properties are the hydrogen absorption/desorption rate, a smaller process enthalpy and a great structural stability on long term hydrogen absorption/desorption cycling. These properties require metal hydrides with large differences between the hydrogen absorption and desorption pressures at equilibrium, within a rather small temperature range. The main goal of this work is to search and develop metal hydride integrated systems for hydrogen purification, storage and compression. After a careful screening three hydrogen absorbing alloys will be selected. After selection, the work up of the alloys composition on the bases of detailed solid state studies, new multi-component alloys will be developed, with suitable thermodynamic and kinetic properties for a hydrogen compressor. The results of the study are the following: new types of hydrogen

Anomalous ortho-para conversion of solid hydrogen in constrained geometries

International Nuclear Information System (INIS)

Rall, M.; Brison, J.P.; Sullivan, N.S.

1991-01-01

Using cw NMR techniques, we have measured the ortho-para conversion of solid hydrogen constrained to the interior of the molecular cages of zeolite. The conversion observed in the constrained geometry is very different from that of bulk solid hydrogen. Two distinct conversion rates were observed for short and long times. An apparently bimolecular conversion rate of 0.43% h -1 (one-fourth of the bulk value) dominates during the first 500 h, and the rate then increases to 2.2% h -1 . The initial slow rate is explained in terms of a reduced number of nearest neighbors and possible wall effects, and the fast rate is attributed to the formation of small ortho-H 2 Rclusters at later times. Surface effects due to magnetic impurities do not appear to determine the conversion rate in the samples studied

Reassigning hydrogen-bond centering in dense ice

International Nuclear Information System (INIS)

Benoit, Magali; Romero, Aldo H.; Marx, Dominik

2002-01-01

Hydrogen bonds in H 2 O ice change dramatically upon compression. Thereby a hydrogen-bonded molecular crystal, ice VII, is transformed to an atomic crystal, ice X. Car-Parrinello simulations reproduce the features of the x-ray diffraction spectra up to about 170 GPa but allow for analysis in real space. Starting from molecular ice VII with static orientational disorder, dynamical translational disordering occurs first via creation of ionic defects, which results in a systematic violation of the ice rules. As a second step, the transformation to an atomic solid and thus hydrogen-bond centering occurs around 110 GPa at 300 K and no novel phase is found up to at least 170 GPa

The long range migration of hydrogen through Zircaloy in response to tensile and compressive stress gradients

International Nuclear Information System (INIS)

Kammenzind, B.F.; Berquist, B.M.; Bajaj, R.; Kreyns, P.H.; Franklin, D.G.

1998-01-01

Zircaloy-4, which is used widely as a core structural material in pressurized water reactors (PWRs), picks up hydrogen during service. Hydrogen solubility in Zircaloy-4 is low and zirconium hydride phases precipitate after the Zircaloy-4 lattice becomes supersaturated with hydrogen. These hydrides embrittle the Zircaloy-4, degrading its mechanical performance as a structural material. Because hydrogen can move rapidly through the Zircaloy-4 lattice, the potential exists for large concentrations of hydride to accumulate in local regions of a Zircaloy component remote from its point of entry into the component. Much has been reported in the literature regarding the long range migration of hydrogen through Zircaloy under concentration gradients and temperature gradients. Relatively little has been reported, however, regarding the long range migration of hydrogen under stress gradients. This paper presents experimental results regarding the long range migration of hydrogen through Zircaloy in response to both tensile and compressive stress gradients. The importance of this driving force for hydrogen migration relative to concentration and thermal gradients is discussed

Four-body interaction energy for compressed solid krypton from quantum theory.

Science.gov (United States)

Tian, Chunling; Wu, Na; Liu, Fusheng; Saxena, Surendra K; Zheng, Xingrong

2012-07-28

The importance of the four-body contribution in compressed solid krypton was first evaluated using the many-body expansion method and the coupled cluster theory with full single and double excitations plus perturbative treatment of triples. All different four-atom clusters existing in the first- and second-nearest neighbor shells of face-centered cubic krypton were considered, and both self-consistent-field Hartree-Fock and correlation parts of the four-body interaction were accurately determined from the ambient conditions up to eightfold volume compression. We find that the four-body interaction energy is negative at compression ratio lower than 2, where the dispersive forces play a dominant role. With increasing the compression, the four-body contribution becomes repulsive and significantly cancels the over-softening effects of the three-body potential. The obtained equation of state (EOS) was compared with the experiments and the density-functional theory calculations. It shows that combination of the four-body effects with two- and three-body interactions leads to an excellent agreement with EOS measurements throughout the whole experimental range 0-130 GPa, and extends the prediction to 300 GPa.

Hydrogen and deuterium NMR of solids by magic-angle spinning

International Nuclear Information System (INIS)

Eckman, R.R.

1982-10-01

The nuclear magnetic resonance of solids has long been characterized by very large specral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, β/sub m/ = Arccos (3/sup -1/2/), with respect to the direction of the external magnetic field. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of β. A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H/sub D/ was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal motion. In the general case of large H/sub D/, isotropic spectra were obtained by dilution of 1 H with 2 H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids

Phonons in Solid Hydrogen and Deuterium Studied by Inelastic Coherent Neutron Scattering

DEFF Research Database (Denmark)

Nielsen, Mourits

1973-01-01

Phonon dispersion relations have been measured by coherent neutron scattering in solid para-hydrogen and ortho-deuterium. The phonon energies are found to be nearly equal in the two solids, the highest energy in each case lying close to 10 meV. The pressure and temperature dependence of the phonon...... energies have been measured in ortho-deuterium and the lattice change determined by neutron diffraction. When a pressure of 275 bar is applied, the phonon energies are increased by about 10%, and heating the crystal to near the melting point decreases them by about 7%. The densities of states, the specific...... heats, and the Debye temperatures have been deduced and found to be in agreement with the published experimental results. The Debye temperatures are 118 K for hydrogen and 114 K for deuterium. For hydrogen the Debye-Waller factor has been measured by incoherent neutron scattering and it corresponds...

Hydrogen isotope effect through Pd in hydrogen transport pipe

International Nuclear Information System (INIS)

Tamaki, Masayoshi

1992-01-01

This investigation concerns hydrogen system with hydrogen transport pipes for transportation, purification, isotope separation and storage of hydrogen and its isotopes. A principle of the hydrogen transport pipe (heat pipe having hydrogen transport function) was proposed. It is comprised of the heat pipe and palladium alloy tubes as inlet, outlet, and the separation membrane of hydrogen. The operation was as follows: (1) gas was introduced into the heat pipe through the membrane in the evaporator; (2) the introduced gas was transported toward the condenser by the vapor flow; (3) the transported gas was swept and compressed to the end of the condenser by the vapor pressure; and (4) the compressed gas was exhausted from the heat pipe through the membrane in the condenser. The characteristics of the hydrogen transport pipe were examined for various working conditions. Basic performance concerning transportation, evacuation and compression was experimentally verified. Isotopic dihydrogen gases (H 2 and D 2 ) were used as feed gas for examining the intrinsic performance of the isotope separation by the hydrogen transport pipe. A simulated experiment for hydrogen isotope separation was carried out using a hydrogen-helium gas mixture. The hydrogen transport pipe has a potential for isotope separation and purification of hydrogen, deuterium and tritium in fusion reactor technology. (author)

A pyrolysis/gas chromatographic method for the determination of hydrogen in solid samples

Science.gov (United States)

Carr, R. H.; Bustin, R.; Gibson, E. K.

1987-01-01

A method is described for the determination of hydrogen in solid samples. The sample is heated under vacuum after which the evolved gases are separated by gas chromatography with a helium ionization detector. The system is calibrated by injecting known amounts of hydrogen, as determined manometrically. The method, which is rapid and reliable, was checked for a variety of lunar soils; the limit of detection is about 10 ng of hydrogen.

Interactions of solid and liquid lithium with steady state hydrogen and helium plasmas

International Nuclear Information System (INIS)

Hirooka, Y.; Nishikawa, M.; Ohgaki, H.; Ohtsuka, Y.

2005-01-01

A variety of innovative Plasma-Facing Component (PFC) concepts, employing moving solid or liquid surfaces, have recently been proposed in order to resolve technical issues, associated with the applications of currently used PFCs in future steady state fusion devices. As the first step to evaluate the concept using flowing-liquids for PFCs, steady state hydrogen and helium plasma interactions with solid and standing liquid lithium have been investigated in the present work, using the H α and He-I spectroscopy at the ion bombarding energies up to 150eV and at the lithium temperatures between room temperature and 480 deg C. Data indicate that hydrogen recycling over liquid lithium is clearly reduced, relative to that over solid lithium, whereas helium recycling does not show the same trend. From the kinetic analysis of these recycling time constant data, the activation energies for the overall recycling processes have been evaluated to be 0.02±0.01eV, both for hydrogen and helium plasmas. Also, it has been found that the activation energy is nearly independent of ion bombarding energy. (author)

Current Development in Treatment and Hydrogen Energy Conversion of Organic Solid Waste

Science.gov (United States)

Shin, Hang-Sik

2008-02-01

This manuscript summarized current developments on continuous hydrogen production technologies researched in Korea advanced institute of science and technology (KAIST). Long-term continuous pilot-scale operation of hydrogen producing processes fed with non-sterile food waste exhibited successful results. Experimental findings obtained by the optimization processes of growth environments for hydrogen producing bacteria, the development of high-rate hydrogen producing strategies, and the feasibility tests for real field application could contribute to the progress of fermentative hydrogen production technologies. Three major technologies such as controlling dilution rate depending on the progress of acidogenesis, maintaining solid retention time independently from hydraulic retention time, and decreasing hydrogen partial pressure by carbon dioxide sparging could enhance hydrogen production using anaerobic leaching beds reactors and anaerobic sequencing batch reactors. These findings could contribute to stable, reliable and effective performances of pilot-scale reactors treating organic wastes.

Complex Metal Hydrides for hydrogen storage and solid-state ion conductors

DEFF Research Database (Denmark)

Payandeh GharibDoust, SeyedHosein

and electricity in batteries. However, both hydrogen and electricity must be stored in a very dense way to be useful, e.g. for mobile applications. Complex metal hydrides have high hydrogen density and have been studied during the past twenty years in hydrogen storage systems. Moreover, they have shown high ionic...... conductivities which promote their application as solid electrolytes in batteries. This dissertation presents the synthesis and characterization of a variety of complex metal hydrides and explores their hydrogen storage properties and ionic conductivity. Five halide free rare earth borohydrides RE(BH4)3, (RE...... = La, Ce, Pr, Nd, Er) have been synthesized, which pave the way for studying the polymorphic transition in these compounds, obtaining new bimetallic borohydrides and designing new reactive hydride composites with improved hydrogen storage capacities. Two novel polymorphs of Pr(BH4)3 are identified...

ESR study on hydrogen-atom abstraction in cryogenic organic solids

International Nuclear Information System (INIS)

Ichikawa, Tsuneki

1995-01-01

The present paper summarizes our recent results on the hydrogen-atom abstraction from protiated alkane molecule by deuterium atoms in cryogenic deuterated organic solids, obtained by the X-band ESR and electron spin-echo measurements of the product alkyl radicals at cryogenic temperatures. (J.P.N.)

Hydrogen production by gasification of municipal solid waste

Energy Technology Data Exchange (ETDEWEB)

Rogers, R. III

1994-05-20

As fossil fuel reserves run lower and lower, and as their continued widespread use leads toward numerous environmental problems, the need for clean and sustainable energy alternatives becomes ever clearer. Hydrogen fuel holds promise as such as energy source, as it burns cleanly and can be extracted from a number of renewable materials such as municipal solid waste (MSW), which can be considered largely renewable because of its high content of paper and biomass-derived products. A computer model is being developed using ASPEN Plus flow sheeting software to simulate a process which produces hydrogen gas from MSW; the model will later be used in studying the economics of this process and is based on an actual Texaco coal gasification plant design. This paper gives an overview of the complete MSW gasification process, and describes in detail the way in which MSW is modeled by the computer as a process material. In addition, details of the gasifier unit model are described; in this unit modified MSW reacts under pressure with oxygen and steam to form a mixture of gases which include hydrogen.

Feasibility of solid oxide fuel cell dynamic hydrogen coproduction to meet building demand

Science.gov (United States)

Shaffer, Brendan; Brouwer, Jacob

2014-02-01

A dynamic internal reforming-solid oxide fuel cell system model is developed and used to simulate the coproduction of electricity and hydrogen while meeting the measured dynamic load of a typical southern California commercial building. The simulated direct internal reforming-solid oxide fuel cell (DIR-SOFC) system is controlled to become an electrical load following device that well follows the measured building load data (3-s resolution). The feasibility of the DIR-SOFC system to meet the dynamic building demand while co-producing hydrogen is demonstrated. The resulting thermal responses of the system to the electrical load dynamics as well as those dynamics associated with the filling of a hydrogen collection tank are investigated. The DIR-SOFC system model also allows for resolution of the fuel cell species and temperature distributions during these dynamics since thermal gradients are a concern for DIR-SOFC.

Investigation on molecular interaction of amino acids in aqueous disodium hydrogen phosphate solutions with reference to volumetric and compressibility measurements

International Nuclear Information System (INIS)

Kumar, Harsh; Singla, Meenu; Jindal, Rajeev

2014-01-01

Highlights: • Densities and speeds of sound of amino acids in aqueous disodium hydrogen phosphate. • Partial molar volumes and compressibility of transfer. • Positive values of transfer volume indicates interactions between ions of amino acids and TSC. • Ion–hydrophilic and hydrophilic–hydrophilic interactions are present. • Pair-wise interactions are dominant in the mixtures. -- Abstract: The interactions of amino acids glycine (Gly), L-alanine (Ala), and L-valine (Val) with disodium hydrogen phosphate (DSHP) as a function of temperature have been investigated by combination of volumetric and acoustic measurements. Densities (ρ) and speeds of sound (u) of amino acids in aqueous solutions of disodium hydrogen phosphate have been measured at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K and atmospheric pressure. The apparent molar volume (V ϕ ), the partial molar volume (V ϕ 0 ) and standard partial molar volumes of transfer (ΔV ϕ 0 ) for amino acids from water to aqueous disodium hydrogen phosphate solutions have been calculated from density data. Partial molar adiabatic compressibility (κ ϕ,s ) and partial molar adiabatic compressibility of transfer (Δκ ϕ,S 0 ) have been calculated from speed of sound data. The pair (V AB , κ AB ) and triplet (V ABB , κ ABB ) interaction coefficient have been calculated from both the properties. The results have been explained based on competing patterns of interactions of co-solvents and the solute

Solid State NMR Characterization of Complex Metal Hydrides systems for Hydrogen Storage Applications

Directory of Open Access Journals (Sweden)

Son-Jong Hwang

2011-12-01

Full Text Available Solid state NMR is widely applied in studies of solid state chemistries for hydrogen storage reactions. Use of 11B MAS NMR in studies of metal borohydrides (BH4 is mainly focused, revisiting the issue of dodecaborane formation and observation of 11B{1H} Nuclear Overhauser Effect.

Hydrogen evolution from water using solid carbon and light energy

Energy Technology Data Exchange (ETDEWEB)

Kawai, T; Sakata, T

1979-11-15

Hydrogen is produced from water vapour and solid carbon when mixed powders of TiO2, RuO2 and active carbon exposed to water vapor at room temperature, or up to 80 C, are illuminated. At 80 C, the rate of CO and COat2 formation increased. Therefore solar energy would be useful here as a combination of light energy and heat energy. Oxygen produced on the surface of the photocatalyst has a strong oxidising effect on the carbon. It is suggested that this process could be used for coal gasification and hydrogen production from water, accompanied by storage of solar energy.

Prospects for hydrogen storage in graphene.

Science.gov (United States)

Tozzini, Valentina; Pellegrini, Vittorio

2013-01-07

Hydrogen-based fuel cells are promising solutions for the efficient and clean delivery of electricity. Since hydrogen is an energy carrier, a key step for the development of a reliable hydrogen-based technology requires solving the issue of storage and transport of hydrogen. Several proposals based on the design of advanced materials such as metal hydrides and carbon structures have been made to overcome the limitations of the conventional solution of compressing or liquefying hydrogen in tanks. Nevertheless none of these systems are currently offering the required performances in terms of hydrogen storage capacity and control of adsorption/desorption processes. Therefore the problem of hydrogen storage remains so far unsolved and it continues to represent a significant bottleneck to the advancement and proliferation of fuel cell and hydrogen technologies. Recently, however, several studies on graphene, the one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have highlighted the potentialities of this material for hydrogen storage and raise new hopes for the development of an efficient solid-state hydrogen storage device. Here we review on-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage and suggest possible developments for efficient storage/release of hydrogen under ambient conditions.

Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion.

Science.gov (United States)

Tanabe, Katsuaki

2016-01-01

We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

Ab initio study of structural and mechanical property of solid molecular hydrogens

Science.gov (United States)

Ye, Yingting; Yang, Li; Yang, Tianle; Nie, Jinlan; Peng, Shuming; Long, Xinggui; Zu, Xiaotao; Du, Jincheng

2015-06-01

Ab initio calculations based on density functional theory (DFT) were performed to investigate the structural and the elastic properties of solid molecular hydrogens (H2). The influence of molecular axes of H2 on structural relative stabilities of hexagonal close-packed (hcp) and face-centered cubic (fcc) structured hydrogen molecular crystals were systematically investigated. Our results indicate that for hcp structures, disordered hydrogen molecule structure is more stable, while for fcc structures, Pa3 hydrogen molecular crystal is most stable. The cohesive energy of fcc H2 crystal was found to be lower than hcp. The mechanical properties of fcc and hcp hydrogen molecular crystals were obtained, with results consistent with previous theoretical calculations. In addition, the effects of zero point energy (ZPE) and van der Waals (vdW) correction on the cohesive energy and the stability of hydrogen molecular crystals were systematically studied and discussed.

Solid oxide fuel cells and hydrogen production

International Nuclear Information System (INIS)

Dogan, F.

2009-01-01

'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

Insulator-metal transition of fluid molecular hydrogen

International Nuclear Information System (INIS)

Ross, M.

1996-01-01

Dynamically compressed fluid hydrogen shows evidence for metallization at the relatively low pressure of 140 GPa (1.4 Mbar) while experiments on solid hydrogen made in a diamond-anvil cell have failed to detect any evidence for gap closure up to a pressure of 230 GPa (2.3 Mbar). Two possible mechanisms for metal- liclike resistivity are put forward. The first is that as a consequence of the large thermal disorder in the fluid (kT∼0.2 endash 0.3 eV) short-range molecular interactions lead to band tailing that extends the band edge into the gap, resulting in closure at a lower pressure than in the solid. The second mechanism argues that molecular dissociation creates H atoms that behave similar to n-type donors in a heavily doped semiconductor and undergo a nonmetal-metal Mott-type transition. copyright 1996 The American Physical Society

Hydrogen production through high-temperature electrolysis in a solid oxide cell

International Nuclear Information System (INIS)

Herring, J.St.; Lessing, P.; O'Brien, J.E.; Stoots, C.; Hartvigsen, J.; Elangovan, S.

2004-01-01

An experimental research programme is being conducted by the INEEL and Ceramatec, Inc., to test the high-temperature, electrolytic production of hydrogen from steam using a solid oxide cell. The research team is designing and testing solid oxide cells for operation in the electrolysis mode, producing hydrogen rising a high-temperature heat and electrical energy. The high-temperature heat and the electrical power would be supplied simultaneously by a high-temperature nuclear reactor. Operation at high temperature reduces the electrical energy requirement for electrolysis and also increases the thermal efficiency of the power-generating cycle. The high-temperature electrolysis process will utilize heat from a specialized secondary loop carrying a steam/hydrogen mixture. It is expected that, through the combination of a high-temperature reactor and high-temperature electrolysis, the process will achieve an overall thermal conversion efficiency of 40 to 50%o while avoiding the challenging chemistry and corrosion issues associated with the thermochemical processes. Planar solid oxide cell technology is being utilised because it has the best potential for high efficiency due to minimized voltage and current losses. These losses also decrease with increasing temperature. Initial testing has determined the performance of single 'button' cells. Subsequent testing will investigate the performance of multiple-cell stacks operating in the electrolysis mode. Testing is being performed both at Ceramatec and at INEEL. The first cells to be tested were single cells based on existing materials and fabrication technology developed at Ceramatec for production of solid oxide fuel cells. These cells use a relatively thick (∼ 175 μm) electrolyte of yttria- or scandia-stabilised zirconia, with nickel-zirconia cermet anodes and strontium-doped lanthanum manganite cathodes. Additional custom cells with lanthanum gallate electrolyte have been developed and tested. Results to date have

Anisotropic intermolecular interaction and rotational ordering in hydrogen-containing solids. Progress report No. 12

Energy Technology Data Exchange (ETDEWEB)

1976-01-01

Progress is reviewed in these areas: nuclear spin-lattice relaxation in ortho-para mixtures of solid deuterium below T/sub lambda/; pulsed NMR experiments of matrix isolated HCl; stimulated Raman scattering in solid hydrogen and nitrogen; and infrared line broadening of matrix isolated molecules. (GHT)

Anisotropic intermolecular interaction and rotational ordering in hydrogen-containing solids. Progress report No. 12

International Nuclear Information System (INIS)

1976-01-01

Progress is reviewed in these areas: nuclear spin-lattice relaxation in ortho-para mixtures of solid deuterium below T/sub lambda/; pulsed NMR experiments of matrix isolated HCl; stimulated Raman scattering in solid hydrogen and nitrogen; and infrared line broadening of matrix isolated molecules

High density hydrogen research

International Nuclear Information System (INIS)

Hawke, R.S.

1977-01-01

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

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

International Nuclear Information System (INIS)

Thomas, C.E. Jr.

1981-03-01

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

Non-equilibrium hydrogen exchange for determination of H-bond strength and water accessibility in solid proteins.

Science.gov (United States)

Grohe, Kristof; Movellan, Kumar Tekwani; Vasa, Suresh Kumar; Giller, Karin; Becker, Stefan; Linser, Rasmus

2017-05-01

We demonstrate measurement of non-equilibrium backbone amide hydrogen-deuterium exchange rates (HDX) for solid proteins. The target of this study are the slowly exchanging residues in solid samples, which are associated with stable secondary-structural elements of proteins. These hydrogen exchange processes escape methods measuring equilibrium exchange rates of faster processes. The method was applied to a micro-crystalline preparation of the SH3 domain of chicken α-spectrin. Therefore, from a 100% back-exchanged micro-crystalline protein preparation, the supernatant buffer was exchanged by a partially deuterated buffer to reach a final protonation level of approximately 20% before packing the sample in a 1.3 mm rotor. Tracking of the HN peak intensities for 2 weeks reports on site-specific hydrogen bond strength and also likely reflects water accessibility in a qualitative manner. H/D exchange can be directly determined for hydrogen-bonded amides using 1 H detection under fast magic angle spinning. This approach complements existing methods and provides the means to elucidate interesting site-specific characteristics for protein functionality in the solid state.

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

DEFF Research Database (Denmark)

Sørensen, H.

1977-01-01

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

Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion

Directory of Open Access Journals (Sweden)

Katsuaki Tanabe

2016-01-01

Full Text Available We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

Vibration-rotational overtones absorption of solid hydrogens using optoacoustic spectroscopy technique

International Nuclear Information System (INIS)

Vieira, M.M.F.

1985-01-01

Vibrational-rotational overtones absorption solid hydrogens (H 2 , D 2 , HD) is studied using pulsed laser piezoeletric transducer (PULPIT) optoacoustic spectroscopy is studied. A general downward shift in energy from isolated molecular energies is observed. Studying normal-hydrogen it was observed that the phonon excitations associated with double-molecular transitions are predominantly transverse-optical phonons, whereas the excitations associated with single-molecular transitions are predominantly longitudinal - optical phonons. Multiplet structures were observed for certain double transitions in parahydrogen and orthodeuterium. The HD spectrum, besides presenting the sharp zero-phonon lines and the associated phonon side bands, like H 2 and D 2 , showed also two different features. This observation was common to all the transitions involving pure rotational excitation in H 2 and D 2 , which showed broad linewidths. This, together with some other facts (fluorescence lifetime *approx*10 5 sec; weak internal vibration and lattice coupling), led to the proposition of a mechanism for the fast nonradiative relaxation in solid hydrogens, implied from some observed experimental evidences. This relaxation, due to strong coupling, would happen in two steps: the internal vibration modes would relax to the rotational modes of the molecules, and then this rotational modes would relax to the lattice vibration modes. (Author) [pt

Time-resolved shock compression of porous rutile: Wave dispersion in porous solids

Energy Technology Data Exchange (ETDEWEB)

Anderson, M.U.; Graham, R.A.; Holman, G.T.

1993-08-01

Rutile (TiO{sub 2}) samples at 60% of solid density have been shock-loaded from 0.21 to 6.1 GPa with sample thickness of 4 mm and studied with the PVDF piezoelectric polymer stress-rate gauge. The technique uses a copper capsule to contain the sample which has PVDF gauge packages in direct contact with front and rear surfaces. A precise measure is made of the compressive stress wave velocity through the sample, as well as the input and propagated shock stress. Initial density is known from sample preparation, and the amount of shock-compression is calculated from the measurement of shock velocity and input stress. Shock states and re-shock states are measured. Observed data are consistent with previously published high pressure data. It is observed that rutile has a ``crush strength`` near 6 GPa. Propagated stress-pulse rise times vary from 234 to 916 nsec. Propagated stress-pulse rise times of shock-compressed HMX, 2Al + Fe{sub 2}O{sub 3}, 3Ni + Al, and 5Ti + 3Si are presented.

Metal Hydride Compression

Energy Technology Data Exchange (ETDEWEB)

Johnson, Terry A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bowman, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Barton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anovitz, Lawrence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jensen, Craig [Hawaii Hydrogen Carriers LLC, Honolulu, HI (United States)

2017-07-01

Conventional hydrogen compressors often contribute over half of the cost of hydrogen stations, have poor reliability, and have insufficient flow rates for a mature FCEV market. Fatigue associated with their moving parts including cracking of diaphragms and failure of seal leads to failure in conventional compressors, which is exacerbated by the repeated starts and stops expected at fueling stations. Furthermore, the conventional lubrication of these compressors with oil is generally unacceptable at fueling stations due to potential fuel contamination. Metal hydride (MH) technology offers a very good alternative to both conventional (mechanical) and newly developed (electrochemical, ionic liquid pistons) methods of hydrogen compression. Advantages of MH compression include simplicity in design and operation, absence of moving parts, compactness, safety and reliability, and the possibility to utilize waste industrial heat to power the compressor. Beyond conventional H2 supplies of pipelines or tanker trucks, another attractive scenario is the on-site generating, pressuring and delivering pure H₂ at pressure (≥ 875 bar) for refueling vehicles at electrolysis, wind, or solar generating production facilities in distributed locations that are too remote or widely distributed for cost effective bulk transport. MH hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas to form the MH phase and is a promising process for hydrogen energy applications [1,2]. To deliver hydrogen continuously, each stage of the compressor must consist of multiple MH beds with synchronized hydrogenation & dehydrogenation cycles. Multistage pressurization allows achievement of greater compression ratios using reduced temperature swings compared to single stage compressors. The objectives of this project are to investigate and demonstrate on a laboratory scale a two-stage MH hydrogen (H₂) gas compressor with a

The high pressure equation of state of the isotopes of solid hydrogen and helium

International Nuclear Information System (INIS)

Driessen, A.

1982-01-01

The initial aim of this thesis was to provide the high pressure equipment and the knowledge about the equation of state (EOS) necessary for a research program in a laboratory dealing with spectroscopy of solid hydrogen under high pressure. Once this first goal was reached, a logical step was to extend the work on the EOS to all three hydrogen isotopes and later also to the helium isotpes. During the experiments on the EOS of hydrogen, the effects of the concentration C 1 of the rotationally excited molecules provoked interest, resulting in an extensive experimental and theoretical study. Chapter I describes the results and experience with high pressure equipment for hydrogen up to 7 kbar and chapter II gives a short general introduction to the calculation of the EOS by introducing the Mie-Grueneisen picture and the Silvera-Goldman (SG) potential for hydrogen. Chapter III gives the results of the first EOS of H 2 and D 2 and chapter IV gives a prediction of the EOS of solid T 2 with aid of the SG potential and the experimental results of H 2 and D 2 . Chapter V presents calculations on the thermal expansion of the hydrogen isotopes, which are compared with direct experiments and chapter VI deals in detail with the influence of C 1 on the EOS of H 2 . Ortho-para conversion in hydrogen is considered in chapter VII, and chapter VIII describes experiments on 4 He. (Auth.)

Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

DEFF Research Database (Denmark)

Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

2015-01-01

Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society...

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Indium-hydrogen complexes in silicon and germanium under compression and tension

International Nuclear Information System (INIS)

Marx, G.; Vianden, R.

1996-01-01

The response of hydrogen-acceptor complexes in silicon and germanium to the application of uniaxial mechanical stress was studied by means of the perturbed angular correlation technique. This hyperfine interaction technique is sensitive to the microscopic structure of the immediate lattice environment of the probe atom. For the measurements, the probe 111 In was introduced into Si and Ge crystals by ion implantation at room temperature. After annealing, the radioactive probe atom 111 In acts as an acceptor in the elemental semiconductors Si and Ge and as such can easily be passivated by hydrogen indiffusion. The resulting In-H complex was subsequently exposed to uniaxial compressive and tensile stress, which was produced by bending the crystals along the three major lattice directions left angle 100 right angle, left angle 110 right angle and left angle 111 right angle. It was found that the application of uniaxial mechanical stress causes no change in the population of the four equivalent bond centred H sites surrounding the In acceptor. Evidence was found for a large mismatch of the lattice parameters between the passivated In implanted layer and the surrounding pure Si. (orig.)

NO ICE HYDROGENATION: A SOLID PATHWAY TO NH2OH FORMATION IN SPACE

International Nuclear Information System (INIS)

Congiu, Emanuele; Dulieu, François; Chaabouni, Henda; Baouche, Saoud; Lemaire, Jean Louis; Fedoseev, Gleb; Ioppolo, Sergio; Lamberts, Thanja; Linnartz, Harold; Laffon, Carine; Parent, Philippe; Cuppen, Herma M.

2012-01-01

Icy dust grains in space act as catalytic surfaces onto which complex molecules form. These molecules are synthesized through exothermic reactions from precursor radicals and, mostly, hydrogen atom additions. Among the resulting products are species of biological relevance, such as hydroxylamine—NH 2 OH—a precursor molecule in the formation of amino acids. In this Letter, laboratory experiments are described that demonstrate NH 2 OH formation in interstellar ice analogs for astronomically relevant temperatures via successive hydrogenation reactions of solid nitric oxide (NO). Inclusion of the experimental results in an astrochemical gas-grain model proves the importance of a solid-state NO+H reaction channel as a starting point for prebiotic species in dark interstellar clouds and adds a new perspective to the way molecules of biological importance may form in space.

Near-infrared analysis of hydrogen-bonding in glass- and rubber-state amorphous saccharide solids.

Science.gov (United States)

Izutsu, Ken-ichi; Hiyama, Yukio; Yomota, Chikako; Kawanishi, Toru

2009-01-01

Near-infrared (NIR) spectroscopic analysis of noncrystalline polyols and saccharides (e.g., glycerol, sorbitol, maltitol, glucose, sucrose, maltose) was performed at different temperatures (30-80 degrees C) to elucidate the effect of glass transition on molecular interaction. Transmission NIR spectra (4,000-12,000 cm(-1)) of the liquids and cooled-melt amorphous solids showed broad absorption bands that indicate random configuration of molecules. Heating of the samples decreased an intermolecular hydrogen-bonding OH vibration band intensity (6,200-6,500 cm(-1)) with a concomitant increase in a free and intramolecular hydrogen-bonding OH group band (6,600-7,100 cm(-1)). Large reduction of the intermolecular hydrogen-bonding band intensity at temperatures above the glass transition (T(g)) of the individual solids should explain the higher molecular mobility and lower viscosity in the rubber state. Mixing of the polyols with a high T(g) saccharide (maltose) or an inorganic salt (sodium tetraborate) shifted both the glass transition and the inflection point of the hydrogen-bonding band intensity to higher temperatures. The implications of these results for pharmaceutical formulation design and process monitoring (PAT) are discussed.

A method of estimating hydrogen in solid and liquid samples by means of neutron thermalisation

International Nuclear Information System (INIS)

Carter, D.H.; Sanders, J.E.

1967-06-01

The count-rate of a cadmium-covered Pu239 fission chamber placed in a reactor neutron flux increases when a hydrogen-containing material is inserted due to the thermalisation of epicadmium neutrons. This effect forms the basis of a non-destructive method of estimating hydrogen in solid or liquid samples, and trial experiments to demonstrate the principles have been made. The sensitivity is such that hydrogen down to 10 p.p.m. in a typical metal should be detected. A useful feature of the method is its very low response to elements other than hydrogen. (author)

Ionic liquid and solid HF equivalent amine-poly(hydrogen fluoride) complexes effecting efficient environmentally friendly isobutane-isobutylene alkylation.

Science.gov (United States)

Olah, George A; Mathew, Thomas; Goeppert, Alain; Török, Béla; Bucsi, Imre; Li, Xing-Ya; Wang, Qi; Marinez, Eric R; Batamack, Patrice; Aniszfeld, Robert; Prakash, G K Surya

2005-04-27

Isoparaffin-olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin-olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane-isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, "green" class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.

Communication: Dynamical and structural analyses of solid hydrogen under vapor pressure

Energy Technology Data Exchange (ETDEWEB)

Hyeon-Deuk, Kim, E-mail: kim@kuchem.kyoto-u.ac.jp [Department of Chemistry, Kyoto University, Kyoto 606-8502 (Japan); Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ando, Koji [Department of Chemistry, Kyoto University, Kyoto 606-8502 (Japan)

2015-11-07

Nuclear quantum effects play a dominant role in determining the phase diagram of H{sub 2}. With a recently developed quantum molecular dynamics simulation method, we examine dynamical and structural characters of solid H{sub 2} under vapor pressure, demonstrating the difference from liquid and high-pressure solid H{sub 2}. While stable hexagonal close-packed lattice structures are reproduced with reasonable lattice phonon frequencies, the most stable adjacent configuration exhibits a zigzag structure, in contrast with the T-shape liquid configuration. The periodic angular distributions of H{sub 2} molecules indicate that molecules are not a completely free rotor in the vapor-pressure solid reflecting asymmetric potentials from surrounding molecules on adjacent lattice sites. Discrete jumps of librational and H–H vibrational frequencies as well as H–H bond length caused by structural rearrangements under vapor pressure effectively discriminate the liquid and solid phases. The obtained dynamical and structural information of the vapor-pressure H{sub 2} solid will be useful in monitoring thermodynamic states of condensed hydrogens.

Feasibility of an energy conversion system in Canada involving large-scale integrated hydrogen production using solid fuels

International Nuclear Information System (INIS)

Gnanapragasam, Nirmal V.; Reddy, Bale V.; Rosen, Marc A.

2010-01-01

A large-scale hydrogen production system is proposed using solid fuels and designed to increase the sustainability of alternative energy forms in Canada, and the technical and economic aspects of the system within the Canadian energy market are examined. The work investigates the feasibility and constraints in implementing such a system within the energy infrastructure of Canada. The proposed multi-conversion and single-function system produces hydrogen in large quantities using energy from solid fuels such as coal, tar sands, biomass, municipal solid waste (MSW) and agricultural/forest/industrial residue. The proposed system involves significant technology integration, with various energy conversion processes (such as gasification, chemical looping combustion, anaerobic digestion, combustion power cycles-electrolysis and solar-thermal converters) interconnected to increase the utilization of solid fuels as much as feasible within cost, environmental and other constraints. The analysis involves quantitative and qualitative assessments based on (i) energy resources availability and demand for hydrogen, (ii) commercial viability of primary energy conversion technologies, (iii) academia, industry and government participation, (iv) sustainability and (v) economics. An illustrative example provides an initial road map for implementing such a system. (author)

Peculiarities of hydrogen permeation through Zr–1%Nb alloy and evaluation of terminal solid solubility

Energy Technology Data Exchange (ETDEWEB)

Denisov, E.A.; Kompaniets, M.V.; Kompaniets, T.N., E-mail: tkompaniets@spbu.ru; Bobkova, I.S.

2016-04-15

Hydrogen permeation through Zr–1%Nb alloy was studied at the temperature below the temperature of α-β transition. Analysis of the transient permeation curves from a closed volume in a surface limited regime allowed to determine total and mobile hydrogen concentrations. At the mobile hydrogen concentration of 4.3 at% a part of the absorbed hydrogen is cut out of permeation process. Increase of the mobile hydrogen concentration in α-phase of Zr–1%Nb alloy is ceasing at the concentration of (5.5 ± 0.3) at%, which is the maximum possible concentration of the mobile hydrogen in α-phase of the studied alloy. From this moment on all absorbed hydrogen is spent on hydride formation. The obtained results are compared with those obtained by means of traditional techniques for terminal solid solubility determination.

Compression Characteristics of Solid Wastes as Backfill Materials

OpenAIRE

Meng Li; Jixiong Zhang; Rui Gao

2016-01-01

A self-made large-diameter compression steel chamber and a SANS material testing machine were chosen to perform a series of compression tests in order to fully understand the compression characteristics of differently graded filling gangue samples. The relationship between the stress-deformation modulus and stress-compression degree was analyzed comparatively. The results showed that, during compression, the deformation modulus of gangue grew linearly with stress, the overall relationship bet...

Translational vibrations between chains of hydrogen-bonded molecules in solid-state aspirin form I

Science.gov (United States)

Takahashi, Masae; Ishikawa, Yoichi

2013-06-01

We perform dispersion-corrected first-principles calculations, and far-infrared (terahertz) spectroscopic experiments at 4 K, to examine translational vibrations between chains of hydrogen-bonded molecules in solid-state aspirin form I. The calculated frequencies and relative intensities reproduce the observed spectrum to accuracy of 11 cm-1 or less. The stronger one of the two peaks assigned to the translational mode includes the stretching vibration of the weak hydrogen bond between the acetyl groups of a neighboring one-dimensional chain. The calculation of aspirin form II performed for comparison gives the stretching vibration of the weak hydrogen bond in one-dimensional chain.

Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiulu [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China); Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, 621010 Mianyang, Sichuan (China); Liu, Zhongli [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China); College of Physics and Electric Information, Luoyang Normal University, 471022 Luoyang, Henan (China); Jin, Ke; Xi, Feng; Yu, Yuying; Tan, Ye; Dai, Chengda; Cai, Lingcang [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China)

2015-02-07

The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of the longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions.

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

International Nuclear Information System (INIS)

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

1992-01-01

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

Kinetics of solid-phase in ion exchange on tin hydrogen phosphate

International Nuclear Information System (INIS)

Kislitsyn, M.N.; Ketsko, V.A.; Yaroslavtsev, A.B.

2004-01-01

Solid state reactions in mixture of tin hydrogen phosphate and alkali metal (M=Na, K, Cs) chlorides have been studied both in the mode of polythermal heating and at a fixed temperature, using data of X-ray phase and thermogravimetric analyses. In the range 400-750 Deg C solid state ion exchange reactions occur in the systems studied and yield mono-- and dialkali phosphates MHSn(PO 4 ) 2 and M 2 Sn(PO 4 ) 2 . Counter diffusion coefficients for alkali metal cations and protons in the matrices of compositions MHSn(PO 4 ) 2 and M 2 Sn(PO 4 ) 2 have been determined [ru

Kinetic energy of solid and liquid para-hydrogen: a path integral Monte Carlo simulation

International Nuclear Information System (INIS)

Zoppi, M.; Neumann, M.

1992-01-01

The translational (center of mass) kinetic energy of solid and liquid para-hydrogen have been recently measured by means of Deep Inelastic Neutron Scattering. We have evaluated the same quantity, in similar thermodynamic conditions, by means of Path Integral Monte Carlo computer simulation, modelling the system as composed of a set of spherical molecules interacting through a pairwise additive Lennard-Jones potential. In spite of the crude approximations on the interaction potential, the agreement is excellent. The pressure was also computed by means of the same simulations. This quantity, compared with the equation of state for solid para-hydrogen given by Driessen and Silvera, gives an agreement of a lesser quality and a negative value for the liquid state. We attribute this discrepancy to the limitations of the Lennard-Jones potential. (orig.)

NO ICE HYDROGENATION: A SOLID PATHWAY TO NH{sub 2}OH FORMATION IN SPACE

Energy Technology Data Exchange (ETDEWEB)

Congiu, Emanuele; Dulieu, Francois; Chaabouni, Henda; Baouche, Saoud; Lemaire, Jean Louis [LERMA-LAMAp, Universite de Cergy-Pontoise, Observatoire de Paris, ENS, UPMC, UMR 8112 du CNRS, 5 Mail Gay Lussac, 95000 Cergy Pontoise Cedex (France); Fedoseev, Gleb; Ioppolo, Sergio; Lamberts, Thanja; Linnartz, Harold [Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden Observatory, University of Leiden, P.O. Box 9513, 2300 RA Leiden (Netherlands); Laffon, Carine; Parent, Philippe [Laboratoire de Chimie-Physique, Matiere et Rayonnement, Universite Pierre-et-Marie Curie (Paris 06) and CNRS (UMR 7614), 11 rue Pierre-et-Marie-Curie, 75231 Paris (France); Cuppen, Herma M., E-mail: emanuele.congiu@u-cergy.fr [Faculty of Science, Radboud University Nijmegen, IMM, P.O. Box 9010, NL 6500 GL Nijmegen (Netherlands)

2012-05-01

Icy dust grains in space act as catalytic surfaces onto which complex molecules form. These molecules are synthesized through exothermic reactions from precursor radicals and, mostly, hydrogen atom additions. Among the resulting products are species of biological relevance, such as hydroxylamine-NH{sub 2}OH-a precursor molecule in the formation of amino acids. In this Letter, laboratory experiments are described that demonstrate NH{sub 2}OH formation in interstellar ice analogs for astronomically relevant temperatures via successive hydrogenation reactions of solid nitric oxide (NO). Inclusion of the experimental results in an astrochemical gas-grain model proves the importance of a solid-state NO+H reaction channel as a starting point for prebiotic species in dark interstellar clouds and adds a new perspective to the way molecules of biological importance may form in space.

Recent Advances in the Use of Sodium Borohydride as a Solid State Hydrogen Store

Directory of Open Access Journals (Sweden)

Jianfeng Mao

2015-01-01

Full Text Available The development of new practical hydrogen storage materials with high volumetric and gravimetric hydrogen densities is necessary to implement fuel cell technology for both mobile and stationary applications. NaBH4, owing to its low cost and high hydrogen density (10.6 wt%, has received extensive attention as a promising hydrogen storage medium. However, its practical use is hampered by its high thermodynamic stability and slow hydrogen exchange kinetics. Recent developments have been made in promoting H2 release and tuning the thermodynamics of the thermal decomposition of solid NaBH4. These conceptual advances offer a positive outlook for using NaBH4-based materials as viable hydrogen storage carriers for mobile applications. This review summarizes contemporary progress in this field with a focus on the fundamental dehydrogenation and rehydrogenation pathways and properties and on material design strategies towards improved kinetics and thermodynamics such as catalytic doping, nano-engineering, additive destabilization and chemical modification.

Investigating the effect of compression on solute transport through degrading municipal solid waste

Energy Technology Data Exchange (ETDEWEB)

Woodman, N.D., E-mail: n.d.woodman@soton.ac.uk; Rees-White, T.C.; Stringfellow, A.M.; Beaven, R.P.; Hudson, A.P.

2014-11-15

Highlights: • The influence of compression on MSW flushing was evaluated using 13 tracer tests. • Compression has little effect on solute diffusion times in MSW. • Lithium tracer was conservative in non-degrading waste but not in degrading waste. • Bromide tracer was conservative, but deuterium was not. - Abstract: The effect of applied compression on the nature of liquid flow and hence the movement of contaminants within municipal solid waste was examined by means of thirteen tracer tests conducted on five separate waste samples. The conservative nature of bromide, lithium and deuterium tracers was evaluated and linked to the presence of degradation in the sample. Lithium and deuterium tracers were non-conservative in the presence of degradation, whereas the bromide remained effectively conservative under all conditions. Solute diffusion times into and out of less mobile blocks of waste were compared for each test under the assumption of dominantly dual-porosity flow. Despite the fact that hydraulic conductivity changed strongly with applied stress, the block diffusion times were found to be much less sensitive to compression. A simple conceptual model, whereby flow is dominated by sub-parallel low permeability obstructions which define predominantly horizontally aligned less mobile zones, is able to explain this result. Compression tends to narrow the gap between the obstructions, but not significantly alter the horizontal length scale. Irrespective of knowledge of the true flow pattern, these results show that simple models of solute flushing from landfill which do not include depth dependent changes in solute transport parameters are justified.

Solution and solid-phase halogen and C-H hydrogen bonding to perrhenate.

Science.gov (United States)

Massena, Casey J; Riel, Asia Marie S; Neuhaus, George F; Decato, Daniel A; Berryman, Orion B

2015-01-28

(1)H NMR spectroscopic and X-ray crystallographic investigations of a 1,3-bis(4-ethynyl-3-iodopyridinium)benzene scaffold with perrhenate reveal strong halogen bonding in solution, and bidentate association in the solid state. A nearly isostructural host molecule demonstrates significant C-H hydrogen bonding to perrhenate in the same phases.

Durability of solid oxide electrolysis cells for hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

2007-05-15

In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

Equation of state and shock compression of carbon-hydrogen and other ablator materials

Science.gov (United States)

Zhang, S.; Militzer, B.; Whitley, H.

2017-12-01

Dynamic compression experiments in planetary interior studies and fusion sciences often implement carbon-hydrogen or other low-Z elements or compounds as ablators. Accurate quantum simulations of these materials enables theoretical investigation of the equation of state (EOS) over temperatures and pressures that are difficult to access experimentally, and can help guide the design of targets for future experiments. In this work, we use path integral Monte Carlo and density functional molecular dynamics to calculate the equation of state of a series of hydrocarbons and other low-Z materials (B, B4C, and BN). For the hydrocarbon with C:H=1:1, we predict the pressure-compression profile to agree remarkably with experiments at low pressures. At high pressures, we find the Hugoniot curve displays a single compression maximum of 4.7 that corresponds to K-shell ionization. This is slightly higher than that of glow-discharge polymers but both occur at the same pressure (0.47 Gbar). We study the linear mixing approximation for the EOS of hydrocarbons and demonstrate its validity at stellar core conditions. We examine the sensitivity of the fusion yield to the EOS of these candidate ablator materials in radiation-hydrodynamic simulations of a direct-drive implosion. We also make detailed comparisons of the EOS and atomic and electronic structure of C and BN, which is useful for systematic improvement of existing EOS models. Prepared by LLNL under Contract DE-AC52-07NA27344.

Heat Analysis of Liquid piston Compressor for Hydrogen Applications

DEFF Research Database (Denmark)

Kermani, Nasrin Arjomand; Rokni, Masoud

2014-01-01

A new hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model is develo......A new hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model...

Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

KAUST Repository

Li, Erqiang

2015-09-07

When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large enough to compress the air. Herein we use high-speed interferometry, with 200 ns time-resolution, to directly observe the thickness evolution of the air layer during the entire bubble entrapment process. The initial disc radius and thickness shows excellent agreement with available theoretical models, based on adiabatic compression. For the largest impact velocities the air is compressed by as much as a factor of 14. Immediately following the contact, the air disc shows rapid vertical expansion. The radial speed of the surface minima just before contact, can reach 50 times the impact velocity of the drop.

Study of suprathermal electron transport in solid or compressed matter for the fast-ignitor scheme

International Nuclear Information System (INIS)

Perez, F.

2010-01-01

The inertial confinement fusion (ICF) concept is widely studied nowadays. It consists in quickly compressing and heating a small spherical capsule filled with fuel, using extremely energetic lasers. Since approximately 15 years, the fast-ignition (FI) technique has been proposed to facilitate the fuel heating by adding a particle beam - electrons generated by an ultra-intense laser - at the exact moment when the capsule compression is at its maximum. This thesis constitutes an experimental study of these electron beams generated by picosecond-scale lasers. We present new results on the characteristics of these electrons after they are accelerated by the laser (energy, divergence, etc.) as well as their interaction with the matter they pass through. The experimental results are explained and reveal different aspects of these laser-accelerated fast electrons. Their analysis allowed for significant progress in understanding several mechanisms: how they are injected into solid matter, how to measure their divergence, and how they can be automatically collimated inside compressed matter. (author) [fr

Hydrogen production from municipal solid waste

Energy Technology Data Exchange (ETDEWEB)

Wallman, P.H.; Richardson, J.H.; Thorsness, C.B. [and others

1996-06-28

We have modified a Municipal Solid Waste (MSW) hydrothermal pretreatment pilot plant for batch operation and blowdown of the treated batch to low pressure. We have also assembled a slurry shearing pilot plant for particle size reduction. Waste paper and a mixture of waste paper/polyethylene plastic have been run in the pilot plant with a treatment temperature of 275{degrees}C. The pilot-plant products have been used for laboratory studies at LLNL. The hydrothermal/shearing pilot plants have produced acceptable slurries for gasification tests from a waste paper feedstock. Work is currently underway with combined paper/plastic feedstocks. When the assembly of the Research Gasification Unit at Texaco (feed capacity approximately 3/4-ton/day) is complete (4th quarter of FY96), gasification test runs will commence. Laboratory work on slurry samples during FY96 has provided correlations between slurry viscosity and hydrothermal treatment temperature, degree of shearing, and the presence of surfactants and admixed plastics. To date, pumpable slurries obtained from an MSW surrogate mixture of treated paper and plastic have shown heating values in the range 13-15 MJ/kg. Our process modeling has quantified the relationship between slurry heating value and hydrogen yield. LLNL has also performed a preliminary cost analysis of the process with the slurry heating value and the MSW tipping fee as parameters. This analysis has shown that the overall process with a 15 MJ/kg slurry gasifier feed can compete with coal-derived hydrogen with the assumption that the tipping fee is of the order $50/ton.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-11-15

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

Terminal solid solubility of hydrogen in titanium

International Nuclear Information System (INIS)

Giroldi, J.P.; Vizcaino, Pablo; Banchik, Abraham David

2003-01-01

A Research and Development program to build a data base is currently under progress to support the local titanium fabrication. In the present work the temperature of the Terminal Solid Solubility on dissolution (TSSd) and precipitation (TSSp) of titanium hydrides in the Ti α-phase were both measured in the same thermal cycle with a Differential Scanning Calorimeter (DSC). The local titanium producer (FAESA) provided ASTM grade 1 pure Ti bars of about 2,5 cm in diameter. Samples weighting between 50 to 200 mg were cut with a diamond disc and the parallelepiped faces were all carefully ground with SiC papers, then picked in a HNO 3 plus HF aqueous solution and finally dried out with ethanol and hot air. Pairs of (TSSd, TSSp) values for α + δ → α and α → α + δ transformation temperatures in titanium were determined with the same calorimetric procedure already used to calculate the TSS values in zirconium. Data were taken from the same sample during the heating up and cooling down cycle of the second calorimeter run made with the same rate of 20 C degrees / minute. The Cathodic Charging technique was used to charge the samples at different hydrogen concentrations between the 'as fabricated' value and the concentration corresponding to the eutectoid temperature. A mixture of glycerin and phosphoric acid in a 2:1 ratio and a current density of 0,05 to 0,1 Amp/cm 2 were applied to different samples during 24 to 96 hours to get a wide range of hydrogen concentrations. A homogenization heat treatment at 400 C degrees for 45 minutes -made at open air in an electric furnace- was applied to each sample to dissolve the massive hydrides at the sample surfaces and diffuse them into the bulk of the sample. The hydrogen concentration of each sample was measured after the final calorimetric run using the Extraction Method in Liquid State under an inert atmosphere using a Leco RH-404 model Hydrogen Determinator. The experimental data follows a linear relationship -with a

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

Energy Technology Data Exchange (ETDEWEB)

Pratapas, John; Mather, Daniel; Kozlovsky, Anton

2013-03-31

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

Solid hydrogen target for laser driven proton acceleration

Science.gov (United States)

Perin, J. P.; Garcia, S.; Chatain, D.; Margarone, D.

2015-05-01

The development of very high power lasers opens up new horizons in various fields, such as laser plasma acceleration in Physics and innovative approaches for proton therapy in Medicine. Laser driven proton acceleration is commonly based on the so-called Target Normal Sheath Acceleration (TNSA) mechanisms: a high power laser is focused onto a solid target (thin metallic or plastic foil) and interact with matter at very high intensity, thus generating a plasma; as a consequence "hot" electrons are produced and move into the forward direction through the target. Protons are generated at the target rear side, electrons try to escape from the target and an ultra-strong quasi-electrostatic field (~1TV/m) is generated. Such a field can accelerate protons with a wide energy spectrum (1-200 MeV) in a few tens of micrometers. The proton beam characteristics depend on the laser parameters and on the target geometry and nature. This technique has been validated experimentally in several high power laser facilities by accelerating protons coming from hydrogenated contaminant (mainly water) at the rear of metallic target, however, several research groups are investigating the possibility to perform experiments by using "pure" hydrogen targets. In this context, the low temperature laboratory at CEA-Grenoble has developed a cryostat able to continuously produce a thin hydrogen ribbon (from 40 to 100 microns thick). A new extrusion concept, without any moving part has been carried out, using only the thermodynamic properties of the fluid. First results and perspectives are presented in this paper.

Semi-solid state fermentation of bagasse for hydrogen production; the cost-effective approach in Indian context

International Nuclear Information System (INIS)

Singh, S.P.; Asthana, R.K.; Singh, A.P.

2006-01-01

Semi-solid state fermentation route of hydrogen production from agro-waste sugar cane bagasse was tried using the photosynthetic bacterium Rhodopseudomonas (BHU strain-1) and the non-photosynthetic Enterobacter aerogenes MTCC2822. The process seems an alternative to submerged fermentation that requires high volumes of nutrient broth. Bagasse (10 g) pre-hydrolyzed with NaOH (2%, w/v) was coated with Ca-alginate (1.5%, v/v) containing Rhodopseudomonas and E. aerogenes in the co-immobilized state (300 μg bacterial biomass ml -1 ). The fermenting medium was just 150 ml to sustain the moistened bagasse in a 0.5 L fermenter kept in light. A parallel set of free bacterial cells served as control. Hydrogen production by the immobilized sets reached 30 L within 60 h with the average rate of 0.177 L H 2 h -1 . For free cells, the values for hydrogen output (20 L) or the rate 0.1125 L H 2 h -1 were approximately 1.5-fold low. It is proposed that semi-solid fermentation route of hydrogen production from bagasse will be a cost-effective technology in countries generating this agro-waste. (authors)

Semi-solid state fermentation of bagasse for hydrogen production; the cost-effective approach in Indian context

Energy Technology Data Exchange (ETDEWEB)

Singh, S.P.; Asthana, R.K.; Singh, A.P. [Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi-221005, (India)

2006-07-01

Semi-solid state fermentation route of hydrogen production from agro-waste sugar cane bagasse was tried using the photosynthetic bacterium Rhodopseudomonas (BHU strain-1) and the non-photosynthetic Enterobacter aerogenes MTCC2822. The process seems an alternative to submerged fermentation that requires high volumes of nutrient broth. Bagasse (10 g) pre-hydrolyzed with NaOH (2%, w/v) was coated with Ca-alginate (1.5%, v/v) containing Rhodopseudomonas and E. aerogenes in the co-immobilized state (300 {mu}g bacterial biomass ml{sup -1}). The fermenting medium was just 150 ml to sustain the moistened bagasse in a 0.5 L fermenter kept in light. A parallel set of free bacterial cells served as control. Hydrogen production by the immobilized sets reached 30 L within 60 h with the average rate of 0.177 L H{sub 2} h{sup -1}. For free cells, the values for hydrogen output (20 L) or the rate 0.1125 L H{sub 2} h{sup -1} were approximately 1.5-fold low. It is proposed that semi-solid fermentation route of hydrogen production from bagasse will be a cost-effective technology in countries generating this agro-waste. (authors)

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

Energy Technology Data Exchange (ETDEWEB)

John Pratapas; Daniel Mather; Anton Kozlovsky

2007-03-31

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen's significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

A two-stage bio hydrogen process for energy generation from municipal solid wastes

International Nuclear Information System (INIS)

Acevedo-Benitez, J. a.; Poggi-Varaldo, H. M.

2009-01-01

Energy supply and disposal of solid wastes are two big challenges that great cities face at the present time. Several experts have shown that hydrogen is the fuel of the future, due to their high energy content (three times more than that of the gasoline) and its clean combustion. (Author)

Achievement report for fiscal 2000 on the phase II research and development for hydrogen utilizing international clean energy system technology (WE-NET). Task 9. Development of liquid hydrogen transportation and storage technologies - 1; 2000 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) dai 2 ki kenkyu kaihatsu. Task 9. Ekitai suiso yuso chozo gijutsu no kaihatsu - 1

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

This paper describes the achievements in fiscal 2000 from the development of liquid hydrogen transportation and storage technologies. Discussions were given on the following three types of specimens as the heat insulation performance test structures: the vacuum panel type (polyurethane foam coated with SUS sheet, while the inside is kept in the vacuum state); the solid vacuum type (combination of polyurethane foam with vacuum heat insulation); and the powder under normal pressure type (a structure in which the ambient of powder pearlite heat insulating material becomes the atmospheric pressure, whereas a SUS case is set up to separate vacuum layer of the test apparatus from atmosphere layer of the specimen, with the SUS case filled with pearlite). Adding the two types of specimens used in the previous fiscal year, five test specimens in total were discussed on the result of the performance tests to advance the database management. As a low temperature strength test for the insulating materials, the compression test was performed on a microsphere being a kind of solid vacuum (normal pressure) heat insulating materials at room temperature, the liquid nitrogen temperature and in liquid hydrogen atmosphere. The compression strength under liquid hydrogen is 1,044 MPa, which is two times greater than the normal temperature strength of 496 MPa, representing the compression strength rising in proportion with temperature drop. Problems were extracted in developing a small capacity liquid hydrogen transportation and storage system. (NEDO)

Microstructure of Semi-Solid 6063 Alloy Fabricated by Radial Forging Combined with Unidirectional Compression Recrystallization and Partial Melting Process

Directory of Open Access Journals (Sweden)

Wang Yongfei

2017-01-01

Full Text Available Radial forging combined with unidirectional compression (RFCUM is introduced in recrystallization and partial melting (RAP to fabricate semi-solid 6063 aluminum alloy, which can be defined as a process of RFCUM-RAP. In this study, the microstructures of semi-solid 6063 alloy prepared by semi-solid isothermal treatment (SSIT and RFCUM-RAP processes are investigated. The results show that, the solid grains of semi-solid alloy prepared by SSIT are large and irregular. However, solid grains of semi-solid billet prepared by RFCUC-RAP are fine and spherical. Additionally, during RFCUC-RAP process, with the increase of isothermal holding time, the shape of solid grain is more and more spherical, but the size of solid grain is gradually increased. To obtain ideal semi-solid microstructure, the optimal isothermal holding temperature and time are 630 °C and 5~10 min, respectively.

Hydrogen outbreak of Zirconium Molybdate Hihydrate

International Nuclear Information System (INIS)

Miura, Yasuhiko; Fukuda, Kazuhiro; Ochi, Eiji

2008-01-01

JNFL is planning to construct a facility for enclosing the hull and end pieces produced due to reprocessing of spent fuel into stainless canisters after compressing, while those hull and end pieces enclosed into the stainless canisters are called 'compressed hulls'. Since the compressed hulls contain moisture absorbent Zirconium Molybdate Hihydrate accompanying hull and end pieces, there is a risk of outbreak of radiolysisradiolysis gas such as hydrogen, etc. by radiolysisradiolysis. This report intends to state the result of radiation irradiation experiment with the purpose of examining the volume of hydrogen outbreak from Zirconium Molybdate Hihydrate of the compressed hulls. (author)

Hydrogen production characteristics of the organic fraction of municipal solid wastes by anaerobic mixed culture fermentation

Energy Technology Data Exchange (ETDEWEB)

Dong, Li; Yu, Zhang [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)]|[Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhenhong, Yuan; Yongming, Sun; Xiaoying, Kong [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

2009-01-15

The hydrogen production from the organic fraction of municipal solid waste (OFMSW) by anaerobic mixed culture fermentation was investigated using batch experiments at 37 C. Seven varieties of typical individual components of OFMSW including rice, potato, lettuce, lean meat, oil, fat and banyan leaves were selected to estimate the hydrogen production potential. Experimental results showed that the boiling treated anaerobic sludge was effective mixed inoculum for fermentative hydrogen production from OFMSW. Mechanism of fermentative hydrogen production indicates that, among the OFMSW, carbohydrates is the most optimal substrate for fermentative hydrogen production compared with proteins, lipids and lignocelluloses. This conclusion was also substantiated by experimental results of this study. The hydrogen production potentials of rice, potato and lettuce were 134 mL/g-VS, 106 mL/g-VS, and 50 mL/g-VS respectively. The hydrogen percentages of the total gas produced from rice, potato and lettuce were 57-70%, 41-55% and 37-67%. (author)

Solid Catalyst with Ionic Liquid Layer (SCILL). A concept to improve the selectivity of selective hydrogenations

Energy Technology Data Exchange (ETDEWEB)

Jess, A.; Korth, W. [Bayreuth Univ. (Germany). Chair of Chemical Engineering

2011-07-01

Catalytic hydrogenations are important for refinery processes, petrochemical applications as well as for numerous processes of the fine chemicals industry. In some cases, hydrogenations consist of a sequence of consecutive reactions, and the desired product is the intermediate. An important goal is then a high yield and selectivity to the intermediate, if possible at a high conversion degree. The selectivity to an intermediate primarily depends on the chemical nature of the catalyst, but may also be influenced by diffusion processes. Ionic liquids (ILs) are low melting salts (< 100 C) and represent a promising solvent class. This paper focuses on the concept of a Solid Catalyst with Ionic Liquid Layer (SCILL), where the solid catalyst is coated with a thin IL layer to improve the selectivity. (orig.)

Hydrogen transport in solids with traps in the case of continuum distribution of detrapping energies

International Nuclear Information System (INIS)

Krasheninnikov, S I; Smirnov, R D; Marenkov, E D; Pisarev, A A

2014-01-01

Tritium retention in the first wall material is one of the key issues in the performance of future fusion reactors. Transport of hydrogenic species in these materials is most commonly treated as diffusion affected by trapping/detrapping processes. Usually only several trap types differing in their activation energies of hydrogen release are considered (up to three types in the TMAP7 code). We suggest that in some cases (e.g. highly damaged or disordered media) the hydrogen trapping/detrapping process is better characterized by a continuum distribution of traps over their detrapping energies. Within a random walk model we show that this assumption leads to qualitative changes in hydrogen transport in solids. Using this model we explain experimental findings on temporal dependence of deuterium outgassing from tokamaks, first wall. (paper)

Foam behavior of solid glass spheres – Zn22Al2Cu composites under compression stresses

International Nuclear Information System (INIS)

Aragon-Lezama, J.A.; Garcia-Borquez, A.; Torres-Villaseñor, G.

2015-01-01

Solid glass spheres – Zn22Al2Cu composites, having different densities and microstructures, were elaborated and studied under compression. Their elaboration process involves alloy melting, spheres submersion into the liquid alloy and finally air cooling. The achieved composites with densities 2.6884, 2.7936 and 3.1219 g/cm 3 were studied in casting and thermally induced, fine-grain matrix microstructures. Test samples of the composites were compressed at a 10 −3 s −1 strain rate, and their microstructure characterized before and after compression by using optical and scanning electron microscopes. Although they exhibit different compression behavior depending on their density and microstructure, all of them show an elastic region at low strains, reach their maximum stress (σ max ) at hundreds of MPa before the stress fall or collapse up to a lowest yield point (LYP), followed by an important plastic deformation at nearly constant stress (σ p ): beyond this plateau, an extra deformation can be limitedly reached only by a significant stress increase. This behavior under compression stresses is similar to that reported for metal foams, being the composites with fine microstructure which nearest behave to metal foams under this pattern. Nevertheless, the relative values of the elastic modulus, and maximum and plateau stresses do not follow the Ashby equations by changing the relative density. Generally, the studied composites behave as foams under compression, except for their peculiar parameters values (σ max , LYP, and σ p )

Safety considerations for compressed hydrogen storage systems

International Nuclear Information System (INIS)

Gleason, D.

2006-01-01

An overview of the safety considerations for various hydrogen storage options, including stationary, vehicle storage, and mobile refueling technologies. Indications of some of the challenges facing the industry as the demand for hydrogen fuel storage systems increases. (author)

Hydrogen production from coal gasification for effective downstream CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Gnanapragasam, Nirmal V.; Reddy, Bale V.; Rosen, Marc A. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada)

2010-05-15

The coal gasification process is used in commercial production of synthetic gas as a means toward clean use of coal. The conversion of solid coal into a gaseous phase creates opportunities to produce more energy forms than electricity (which is the case in coal combustion systems) and to separate CO{sub 2} in an effective manner for sequestration. The current work compares the energy and exergy efficiencies of an integrated coal-gasification combined-cycle power generation system with that of coal gasification-based hydrogen production system which uses water-gas shift and membrane reactors. Results suggest that the syngas-to-hydrogen (H{sub 2}) system offers 35% higher energy and 17% higher exergy efficiencies than the syngas-to-electricity (IGCC) system. The specific CO{sub 2} emission from the hydrogen system was 5% lower than IGCC system. The Brayton cycle in the IGCC system draws much nitrogen after combustion along with CO{sub 2}. Thus CO{sub 2} capture and compression become difficult due to the large volume of gases involved, unlike the hydrogen system which has 80% less nitrogen in its exhaust stream. The extra electrical power consumption for compressing the exhaust gases to store CO{sub 2} is above 70% for the IGCC system but is only 4.5% for the H{sub 2} system. Overall the syngas-to-hydrogen system appears advantageous to the IGCC system based on the current analysis. (author)

Thermophilic anaerobic co-digestion of organic fraction of municipal solid waste (OFMSW) with food waste (FW): Enhancement of bio-hydrogen production.

Science.gov (United States)

Angeriz-Campoy, Rubén; Álvarez-Gallego, Carlos J; Romero-García, Luis I

2015-10-01

Bio-hydrogen production from dry thermophilic anaerobic co-digestion (55°C and 20% total solids) of organic fraction of municipal solid waste (OFMSW) and food waste (FW) was studied. OFMSW coming from mechanical-biological treatment plants (MBT plants) presents a low organic matter concentration. However, FW has a high organic matter content but several problems by accumulation of volatile fatty acids (VFAs) and system acidification. Tests were conducted using a mixture ratio of 80:20 (OFSMW:FW), to avoid the aforementioned problems. Different solid retention times (SRTs) - 6.6, 4.4, 2.4 and 1.9 days - were tested. It was noted that addition of food waste enhances the hydrogen production in all the SRTs tested. Best results were obtained at 1.9-day SRT. It was observed an increase from 0.64 to 2.51 L H2/L(reactor) day in hydrogen productivity when SRTs decrease from 6.6 to 1.9 days. However, the hydrogen yield increases slightly from 33.7 to 38 mL H2/gVS(added). Copyright © 2015 Elsevier Ltd. All rights reserved.

The solid molecular hydrogens in the ordered state as function of density and ortho-para concentration: a far infrared study

International Nuclear Information System (INIS)

Jochemsen, R.

1978-01-01

In this thesis, the results of far infrared absorption experiments on solid molecular hydrogen and deuterium are presented. In Chapter I an introduction to the properties of solid molecular hydrogens in given. The experimental system used for the high pressure infrared measurements and the data handling procedures are discussed in Chapter II. The theory of infrared absorption and the averaging of the dipole moment over the motion of the molecules is contained in Chapter III. In this chapter a general sum rule for the integrated absorption is derived. The remaining chapters present the results of the measurements and the discussion. In Chapter IV the author concentrates on the phonon frequencies as a function of ortho-para concentration and density, while in Chapter V measuremtns of phonon lineshape and integrated absorption intensities are presented. Finally, in Chapter VI, a study is given of the phase transition in solid hydrogen and deuterium. This study provides accurate values for the transition temperature as a function of density (in deuterium) and as a function of ortho-para concentration (in hydrogen) as well as the dependence of the order parameter on the temperature and the ortho-para concentration. (Auth.)

Valorization of Calcium Carbonate-Based Solid Wastes for the Treatment of Hydrogen Sulfide from the Gas Phase

OpenAIRE

Pham Xuan , Huynh; Pham Minh , Doan; Galera Martinez , Marta; Nzihou , Ange; Sharrock , Patrick

2015-01-01

International audience; This paper focuses on the valorization of calcium carbonate-based solid wastes for theremoval of hydrogen sulfide from gas phase. Two solid wastes taken from industrial sites for theproduction of sodium carbonate and sodium bicarbonate by the Solvay process® were analyzedby different physico-chemical methods. Calcium carbonate was found as the main component ofboth the solid wastes. Trace amounts of other elements such as Mg, Al, Fe, Si, Cl, Na etc. werealso present in...

Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen

International Nuclear Information System (INIS)

Raston, P.L.; Kettwich, S.C.; Anderson, D.T.

2010-01-01

We report infrared spectroscopic studies of H 2 ortho-para (o/p) conversion in solid hydrogen doped with Cl-atoms at 2 K while the Cl + H 2 (υ = 1) → HCl + H infrared-induced chemical reaction is occurring. The Cl-atom doped hydrogen crystals are synthesized using 355 nm in situ photodissociation of Cl 2 precursor molecules. For hydrogen solids with high ortho-H 2 fractional concentrations (X o = 0.55), the o/p conversion kinetics is dominated by Cl-atom catalyzed conversion with a catalyzed conversion rate constant K cc = 1.16(11) min -1 and the process is rate-limited by ortho-H 2 quantum diffusion. For hydrogen crystals with low ortho-H2 concentrations (X o = 0.03), single-exponential decay of the ortho-H 2 concentration with time is observed which is attributed to H-atom catalyzed o/p conversion by the H-atoms produced during the infrared-induced Cl + H 2 reaction. The measured H-atom catalyzed o/p conversion kinetics indicates the H-atoms are mobile under these conditions in agreement with previous ESR measurements.

Phase transition of DNA-linked gold nanoparticles: Creation of a high concentration of atomic hydrogen in impurity-helium solids

International Nuclear Information System (INIS)

Kiselev, S.I.; Khmelenko, V.V.; Bernard, E.P.; Lee, C.Y.; Lee, D.M.

2003-01-01

The exchange tunneling reactions D+H 2 →HD+H and D+HD→D 2 +H were used to generate high concentrations of atomic hydrogen in impurity-helium solids. The dependence of atom concentration on the content of hydrogen in the injected gas mixture gave a maximum concentration of 7.5x10 17 cm -3 hydrogen atoms for an initial gas ratio H 2 :D 2 :He=1:4:100

Hydrogen and Hydrogen/Natural Gas Station and Vehicle Operations - 2006 Summary Report

Energy Technology Data Exchange (ETDEWEB)

Francfort; Donald Karner; Roberta Brayer

2006-09-01

This report is a summary of the operations and testing of internal combustion engine vehicles that were fueled with 100% hydrogen and various blends of hydrogen and compressed natural gas (HCNG). It summarizes the operations of the Arizona Public Service Alternative Fuel Pilot Plant, which produces, compresses, and dispenses hydrogen fuel. Other testing activities, such as the destructive testing of a CNG storage cylinder that was used for HCNG storage, are also discussed. This report highlights some of the latest technology developments in the use of 100% hydrogen fuels in internal combustion engine vehicles. Reports are referenced and WWW locations noted as a guide for the reader that desires more detailed information. These activities are conducted by Arizona Public Service, Electric Transportation Applications, the Idaho National Laboratory, and the U.S. Department of Energy’s Advanced Vehicle Testing Activity.

Life cycle assessment integrated with thermodynamic analysis of bio-fuel options for solid oxide fuel cells.

Science.gov (United States)

Lin, Jiefeng; Babbitt, Callie W; Trabold, Thomas A

2013-01-01

A methodology that integrates life cycle assessment (LCA) with thermodynamic analysis is developed and applied to evaluate the environmental impacts of producing biofuels from waste biomass, including biodiesel from waste cooking oil, ethanol from corn stover, and compressed natural gas from municipal solid wastes. Solid oxide fuel cell-based auxiliary power units using bio-fuel as the hydrogen precursor enable generation of auxiliary electricity for idling heavy-duty trucks. Thermodynamic analysis is applied to evaluate the fuel conversion efficiency and determine the amount of fuel feedstock needed to generate a unit of electrical power. These inputs feed into an LCA that compares energy consumption and greenhouse gas emissions of different fuel pathways. Results show that compressed natural gas from municipal solid wastes is an optimal bio-fuel option for SOFC-APU applications in New York State. However, this methodology can be regionalized within the U.S. or internationally to account for different fuel feedstock options. Copyright © 2012 Elsevier Ltd. All rights reserved.

Plasma density measurements on refuelling by solid hydrogen pellets in a rotating plasma

International Nuclear Information System (INIS)

Joergensen, L.W.; Sillesen, A.H.

1978-01-01

The refuelling of a plasma by solid hydrogen pellets situated in the plasma is investigated. Nearly half of the pellet material is evaporated and seems to be completely ionized, resulting in an increase of the amount of plasma equivalent to one third of the total amount of plasma without refuelling. The gross behaviour of the plasma is not changed. (author)

The calculation of specific heats for some important solid components in hydrogen production process based on CuCl cycle

Directory of Open Access Journals (Sweden)

Avsec Jurij

2014-01-01

Full Text Available Hydrogen is one of the most promising energy sources of the future enabling direct production of power and heat in fuel cells, hydrogen engines or furnaces with hydrogen burners. One of the last remainder problems in hydrogen technology is how to produce a sufficient amount of cheap hydrogen. One of the best options is large scale thermochemical production of hydrogen in combination with nuclear power plant. copper-chlorine (CuCl cycle is the most promissible thermochemical cycle to produce cheap hydrogen.This paper focuses on a CuCl cycle, and the describes the models how to calculate thermodynamic properties. Unfortunately, for many components in CuCl cycle the thermochemical functions of state have never been measured. This is the reason that we have tried to calculate some very important thermophysical properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure substances and their mixtures such as CuCl, HCl, Cu2OCl2 important in CuCl hydrogen production in their fluid and solid phase with an aid of statistical thermodynamics. For the solid phase, we have developed the mathematical model for the calculation of thermodynamic properties for polyatomic crystals. In this way, we have used Debye functions and Einstein function for acoustical modes and optical modes of vibrations to take into account vibration of atoms. The influence of intermolecular energy we have solved on the basis of Murnaghan equation of state and statistical thermodynamics.

Foam behavior of solid glass spheres – Zn22Al2Cu composites under compression stresses

Energy Technology Data Exchange (ETDEWEB)

Aragon-Lezama, J.A., E-mail: alja@correo.azc.uam.mx [Departamento de Materiales, Universidad Autónoma Metropolitana-A, Avenida San Pablo 180, Colonia Reynosa Tamaulipas, 02200 México, D.F., México (Mexico); Garcia-Borquez, A., E-mail: a.garciaborquez@yahoo.com.mx [Ciencia de Materiales, ESFM – Instituto Politécnico Nacional, Edif. 9, Unid. Prof. A. Lopez Mateos, Colonia Lindavista, 07738 México, D.F., México (Mexico); Torres-Villaseñor, G., E-mail: gtorres@unam.mx [Departamento de Metálicos y Cerámicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apdo., P 70-360, México, D.F., México (Mexico)

2015-06-25

Solid glass spheres – Zn22Al2Cu composites, having different densities and microstructures, were elaborated and studied under compression. Their elaboration process involves alloy melting, spheres submersion into the liquid alloy and finally air cooling. The achieved composites with densities 2.6884, 2.7936 and 3.1219 g/cm{sup 3} were studied in casting and thermally induced, fine-grain matrix microstructures. Test samples of the composites were compressed at a 10{sup −3} s{sup −1} strain rate, and their microstructure characterized before and after compression by using optical and scanning electron microscopes. Although they exhibit different compression behavior depending on their density and microstructure, all of them show an elastic region at low strains, reach their maximum stress (σ{sub max}) at hundreds of MPa before the stress fall or collapse up to a lowest yield point (LYP), followed by an important plastic deformation at nearly constant stress (σ{sub p}): beyond this plateau, an extra deformation can be limitedly reached only by a significant stress increase. This behavior under compression stresses is similar to that reported for metal foams, being the composites with fine microstructure which nearest behave to metal foams under this pattern. Nevertheless, the relative values of the elastic modulus, and maximum and plateau stresses do not follow the Ashby equations by changing the relative density. Generally, the studied composites behave as foams under compression, except for their peculiar parameters values (σ{sub max}, LYP, and σ{sub p})

An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul; Ganjehkaviri, A.

2015-01-01

Highlights: • 40% of energy demand of Malaysia could be supplied by thermochemical process of PSR. • SCWG of PSR is preferable thermochemical process due to char and tar elimination. • Potential of H 2 production from SCWG of PSR is 1.05 × 10 10 kgH 2 per year in Malaysia. • Highly moisturized PSR could be used in hydrogen production by SCWG process. - Abstract: Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO 2 ) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 10 10 kgH 2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from

76 FR 4338 - Research and Development Strategies for Compressed & Cryo-Compressed Hydrogen Storage Workshops

Science.gov (United States)

2011-01-25

... Hydrogen Storage Workshops AGENCY: Fuel Cell Technologies Program, Office of Energy Efficiency and... the National Renewable Energy Laboratory, in conjunction with the Hydrogen Storage team of the EERE... hydrogen storage in the Washington, DC metro area. DATES: The workshops will be held on Monday, February 14...

Kinetic Studies on State of the Art Solid Oxide Cells – A Comparison between Hydrogen/Steam and Reformate Fuels

DEFF Research Database (Denmark)

Njodzefon, Jean-Claude; Graves, Christopher R.; Mogensen, Mogens Bjerg

2015-01-01

Electrochemical reaction kinetics at the electrodes of Solid Oxide Cells (SOCs) were investigated at 700 °C for two cells with different fuel electrode microstructures as well as on a third cell with a reduced active electrode area. Three fuel mixtures were investigated – hydrogen/steam and refor......Electrochemical reaction kinetics at the electrodes of Solid Oxide Cells (SOCs) were investigated at 700 °C for two cells with different fuel electrode microstructures as well as on a third cell with a reduced active electrode area. Three fuel mixtures were investigated – hydrogen....../steam fuel split into two processes with opposing temperature behavior in the reformate fuels. An 87.5% reduction in active electrode area diminishes the gas conversion impedance in the hydrogen/steam fuel at high fuel flow rates. In both reformates, the second and third lowest frequency processes merged...

Process for the liquefaction of solid carbonaceous materials wherein nitrogen is separated from hydrogen via ammonia synthesis

Science.gov (United States)

Stetka, Steven S.; Nazario, Francisco N.

1982-01-01

In a process for the liquefaction of solid carbonaceous materials wherein bottoms residues are upgraded with a process wherein air is employed, the improvement wherein nitrogen buildup in the system is avoided by ammonia synthesis. In a preferred embodiment hydrogen from other portions of the liquefaction process will be combined with hydrogen produced as a result of the bottoms upgrading to increase the H.sub.2 :N.sub.2 ratio in the ammonia reactor.

Tank designs for combined high pressure gas and solid state hydrogen storage

DEFF Research Database (Denmark)

Mazzucco, Andrea

Many challenges have still to be overcome in order to establish a solid ground for significant market penetration of fuel cell hydrogen vehicles. The development of an effective solution for on-board hydrogen storage is one of the main technical tasks that need to be tackled. The present thesis...... deals with the development of a simulation tool to design and compare different vehicular storage options with respect to targets based upon storage and fueling efficiencies. The set targets represent performance improvements with regard to the state-of-the-art technology and are separately defined...... volume. Heat transfer augmentation techniques (e.g. encapsulation) are found to be the reward strategy to achieve the same stored mass and fueling time of the standard technology, while enabling ambient temperature fueling and save the energy cooling demand (4.2 MJ per fueling) at the refueling station....

Solid NMR characterization of hydrogen solid storage matrices

International Nuclear Information System (INIS)

Pilette, M.A.; Charpentier, T.; Berthault, P.

2007-01-01

The aim of this work is to develop and validate characterization tools by NMR imagery and spectroscopy of the structure of materials for hydrogen storage, and of their evolution during load/unload cycles. The two main topics of this work are in one hand the analysis of the local structure of the materials and the understanding of their eventual modifications, and in another hand, the in-situ analysis of the distribution and diffusion of hydrogen inside the storage material. (O.M.)

An Overview of Natural Gas Conversion Technologies for Co-Production of Hydrogen and Value-Added Solid Carbon Products

Energy Technology Data Exchange (ETDEWEB)

Dagle, Robert A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dagle, Vanessa [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Holladay, Jamelyn D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Krause, Theodore R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ahmed, Shabbir [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-11-16

This report was prepared in response to the U.S. Department of Energy Fuel Cell Technologies Office Congressional Appropriation language to support research on carbon-free production of hydrogen using new chemical processes that utilize natural gas to produce solid carbon and hydrogen. The U.S. produces 9-10 million tons of hydrogen annually with more than 95% of the hydrogen produced by steam-methane reforming (SMR) of natural gas. SMR is attractive because of its high hydrogen yield; but it also converts the carbon to carbon dioxide. Non-oxidative thermal decomposition of methane to carbon and hydrogen is an alternative to SMR and produces CO₂-free hydrogen. The produced carbon can be sold as a co-product, thus providing economic credit that reduces the delivered net cost of hydrogen. The combination of producing hydrogen with potentially valuable carbon byproducts has market value in that this allows greater flexibility to match the market prices of hydrogen and carbon. That is, the higher value product can subsidize the other in pricing decisions. In this report we highlight the relevant technologies reported in the literature—primarily thermochemical and plasma conversion processes—and recent research progress and commercial activities. Longstanding technical challenges include the high energetic requirements (e.g., high temperatures and/or electricity requirements) necessary for methane activation and, for some catalytic processes, the separation of solid carbon product from the spent catalyst. We assess current and new carbon product markets that could be served given technological advances, and we discuss technical barriers and potential areas of research to address these needs. We provide preliminary economic analysis for these processes and compare to other emerging (e.g., electrolysis) and conventional (e.g., SMR) processes for hydrogen production. The overarching conclusion of this study is that the cost of hydrogen can be potentially

Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

International Nuclear Information System (INIS)

James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

2005-01-01

An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

On dewetting dynamics of solid films of hydrogen isotopes and its influence on tritium β spectroscopy

International Nuclear Information System (INIS)

Fleischmann, L.; Bonn, J.; Bornschein, B.; Otten, E.W.; Przyrembel, M.; Weinheimer, Ch.

2000-01-01

The dewetting dynamics of solid films of hydrogen isotopes, quench-condensed on a graphite substrate, was measured at various temperatures below desorption by observing the stray light from the film. A schematic model describing the dewetting process by surface diffusion is presented, which agrees qualitatively with our data. The activation energies of different hydrogen isotopes for surface diffusion were determined. The time constant for dewetting of a quench-condensed T 2 film at the working temperature of 1.86 K of the mainz neutrino mass experiment was extrapolated. (orig.)

Heat transfer analysis of liquid piston compressor for hydrogen applications

DEFF Research Database (Denmark)

Kermani, Nasrin Arjomand; Rokni, Masoud

2015-01-01

A hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model is developed...... and through the walls, is investigated and compared with the adiabatic case. The results show that depending on heat transfer correlation, the hydrogen temperature reduces slightly between 0.2% and 0.4% compared to the adiabatic case, at 500bar, due to the large wall resistance and small contact area...... at the interface. Moreover, the results of the sensitivity analysis illustrates that increasing the total heat transfer coefficients at the interface and the wall, together with compression time, play key roles in reducing the hydrogen temperature. Increasing the total heat transfer coefficient at the interface...

The effect of compositional changes on the structural and hydrogen storage properties of (La–Ce)Ni5 type intermetallics towards compounds suitable for metal hydride hydrogen compression

International Nuclear Information System (INIS)

Odysseos, M.; De Rango, P.; Christodoulou, C.N.; Hlil, E.K.; Steriotis, T.; Karagiorgis, G.; Charalambopoulou, G.; Papapanagiotou, T.; Ampoumogli, A.; Psycharis, V.; Koultoukis, E.; Fruchart, D.; Stubos, A.

2013-01-01

Graphical abstract: The effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Highlights: ► Absorption-based systems exploit the properties of reversible metal hydrides. ► AB5 intermetallics are mostly popular for thermal desorption compressors. ► Investigation of H2 absorption/desorption properties of LaNi5 and its derivatives. ► LaNi5 thermodynamic properties adjustment by partially replacing La with rare earths. -- Abstract: The present work has been aiming at the synthesis and study of a series of La 1−x Ce x Ni 5 (x = 0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) alloys in an attempt to investigate possible alterations of the hydrogen absorption/desorption properties The alloys were prepared by induction melting of the constituent elements. The systematic characterization of all new compounds by means of XRD and hydrogen sorption measurements revealed the effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Extensive absorption/desorption experiments (Van’t Hoff diagrams) have shown that such alloys can be used to build a metal hydride compressor (MHC), compressing H 2 gas from 0.2 MPa to 4.2 MPa using cold (20 °C) and hot (80 °C) water

Impact of hydrogen insertion on vehicular natural gas

Energy Technology Data Exchange (ETDEWEB)

Strangueto, Karina Maretti; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. of Mechanical Engineering. Energy Dept.], Email: karinakms@fem.unicamp.br

2010-07-01

This article aims to analyze the possibility of insertion of hydrogen in the vehicular natural gas or even the insertion of the hydrogen in the compressed natural gas used in Brazil. For the production of this hydrogen, the spilled turbinable energy from Itaipu would be harnessed. The calculation of production can be extended to other power plants which are close to the natural gas pipelines, where the hydrogen would be introduced. Then, it was analyzed the consumption of natural gas in vehicles in Brazil, the regulation of transportation, the sales of compressed natural gas to fuelling station, the specifications that the piped gas should follow to be sold, and how much hydrogen could be accepted in the mix. (author)

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

DEFF Research Database (Denmark)

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

1983-01-01

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

Key study on the potential of hydrazine bisborane for solid- and liquid-state chemical hydrogen storage.

Science.gov (United States)

Pylypko, Sergii; Petit, Eddy; Yot, Pascal G; Salles, Fabrice; Cretin, Marc; Miele, Philippe; Demirci, Umit B

2015-05-04

Hydrazine bisborane N2H4(BH3)2 (HBB; 16.8 wt %) recently re-emerged as a potential hydrogen storage material. However, such potential is controversial: HBB was seen as a hazardous compound up to 2010, but now it would be suitable for hydrogen storage. In this context, we focused on fundamentals of HBB because they are missing in the literature and should help to shed light on its effective potential while taking into consideration any risk. Experimental/computational methods were used to get a complete characterization data sheet, including, e.g., XRD, NMR, FTIR, Raman, TGA, and DSC. From the reported results and discussion, it is concluded that HBB has potential in the field of chemical hydrogen storage given that both thermolytic and hydrolytic dehydrogenations were analyzed. In solid-state chemical hydrogen storage, it cannot be used in the pristine state (risk of explosion during dehydrogenation) but can be used for the synthesis of derivatives with improved dehydrogenation properties. In liquid-state chemical hydrogen storage, it can be studied for room-temperature dehydrogenation, but this requires the development of an active and selective metal-based catalyst. HBB is a thus a candidate for chemical hydrogen storage.

Moessbauer study of Mg-Ni(Fe) alloys processed as materials for solid state hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Palade, P.; Principi, G., E-mail: giovanni.principi@unipd.it; Sartori, S.; Maddalena, A. [Universita di Padova, Settore Materiali, DIM (Italy); Lo Russo, S. [Universita di Padova, Dipartimento di Fisica (Italy); Schinteie, G.; Kuncser, V.; Filoti, G. [National Institute for Materials Physics, Solid State Magnetism Department (Romania)

2006-02-15

Mg-Ni-Fe magnesium-rich intermetallic compounds were prepared following two distinct routes. A Mg{sub 88}Ni{sub 11}Fe{sub 1} sample (A) was prepared by melt spinning Mg-Ni-Fe pellets and then by high-energy ball milling for 6 h the obtained ribbons. A (MgH{sub 2}){sub 88}Ni{sub 11}Fe{sub 1} sample (B) was obtained by high-energy ball milling for 20 h a mixture of Ni, Fe and MgH{sub 2} powders in the due proportions. A SPEX8000 shaker mill with a 10:1 ball to powder ratio was used for milling in argon atmosphere. The samples were submitted to repeated hydrogen absorption/desorption cycles in a Sievert type gas-solid reaction controller at temperatures in the range 520 - 590 K and a maximum pressure of 2.5 MPa during absorption. The samples were analysed before and after the hydrogen absorption/desorption cycles by X-ray diffraction and Moessbauer spectroscopy. The results concerning the hydrogen storage properties of the studied compounds are discussed in connection with the micro-structural characteristics found by means of the used analytical techniques. The improved kinetics of hydrogen desorption for sample A, in comparison to sample B, has been ascribed to the different behaviour of iron atoms in the two cases, as proved by Moessbauer spectroscopy. In fact, iron results homogeneously distributed in sample A, partly at the Mg{sub 2}Ni grain boundaries, with catalytic effect on the gas-solid reaction; in sample B, instead, iron is dispersed inside the hydride powder as metallic iron or superparamagnetic iron.

Achievement report for fiscal 1998 on World Energy Network (WE-NET). Subtask 5. Development of hydrogen transportation and storage technologies (development of liquid hydrogen storage facilities); 1998 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 5. Suiso yuso chozo gijutsu no kaiahtsu (ekitai suiso chozo setsubi no kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

An insulation structure suitable for large tanks was tested for insulation capability and strength at the liquid hydrogen temperature for the development of liquid hydrogen storage facilities. For the insulation test, a specimen was built of a porous solid material, and the specimen was given an additional duty of serving a test of a high temperature plate that was to impose loads on the specimen. The test conditions were not met, however, with too much variation in presence in temperature distribution. For the structural material compressive strength test, a method was worked out involving a hard urethane foam material specimen in liquid hydrogen, and was implemented. It was found that the specimen fracture that occurred was in the form of the collapse of the loaded surface. Tests were conducted at three temperatures, which were the normal temperature, the liquid nitrogen temperature, and the liquid hydrogen temperature, and compressive strength was determined for each of the three cases. No great difference in strength resulted from the difference between the two low temperatures. As for compressive strength at low temperatures, it was found that the strength was approximately two times greater than at the normal temperature. The above findings indicate that hard polyurethane foam is on the safe side when it is designed for the normal temperature. (NEDO)

Compression of Fe-Si-H alloys

Science.gov (United States)

Tagawa, S.; Ohta, K.; Hirose, K.

2014-12-01

The light elements in the Earth's core have not been fully identified yet, but hydrogen is now collecting more attention in part because recent planet formation theory suggests that large amount of water should have been brought to the Earth during its formation (giant-impact stage). Nevertheless, the effect of hydrogen on the property of iron alloys is little known so far. The earlier experimental study by Hirao et al. [2004 GRL] examined the compression behavior of dhcp FeHx (x ≈ 1) and found that it becomes much stiffer than pure iron above 50 GPa, where magnetization disappears. Here we examined the solubility of hydrogen into iron-rich Fe-Si alloys and the compression behavior of dhcp Fe-Si-H alloy at room temperature. Fe+6.5wt.%Si or Fe+9wt.%Si foil was loaded into a diamond-anvil cell (DAC), and then liquid hydrogen was introduced at temperatures below 20 K. X-ray diffraction measurements at SPring-8 revealed the formation of a dhcp phase with or without thermal annealing by laser above 8.4 GPa. The concentration of hydrogen in such dhcp lattice was calculated following the formula reported by Fukai [1992]; y = 0.5 and 0.2 for Fe-6.5wt.%Si-H or Fe-9wt.%Si-H alloys, respectively when y is defined as Fe(1-x)SixHy. Unlike Fe-H alloy, hydrogen didn't fully occupy the octahedral sites even under hydrogen-saturated conditions in the case of Fe-Si-H system. Anomaly was observed in obtained pressure-volume curve around 44 Å3 of unit-cell volume for both Fe-6.5wt.%Si-H and Fe-9wt.%Si-H alloys, which may be related to the spin transition in the dhcp phase. They became slightly stiffer at higher pressures, but their compressibility was still similar to that of pure iron.

Re-fermentation os spent solids from dark fermentation allows for a substantial increase of hydrogen production from the organic fraction of municipal solid wastes

International Nuclear Information System (INIS)

Munoz-Paez, K. M.; Pareja-Camacho, J.; Rios-Leal, E.; Valdez-Vazquez, I.; Poggi Varaldo, H. M.

2009-01-01

In the last 10 years, interest on bio hydrogen has resurrected, particularly the research on dark fermentation of solid wastes. In effect, in a context of scarce and expensive fossil fuels, hydrogen can be considered the best energy alternative because it can be produced by biological means, it has the highest energy density, it is versatile since can be used both as a primary or secondary energy source, it is compatible with electrochemical and combustion-based energy conversion processes, and it is environmentally-friendly since water is its main combustion product and no aggressive pollutants are generated. (Author)

Re-fermentation os spent solids from dark fermentation allows for a substantial increase of hydrogen production from the organic fraction of municipal solid wastes

Energy Technology Data Exchange (ETDEWEB)

Munoz-Paez, K. M.; Pareja-Camacho, J.; Rios-Leal, E.; Valdez-Vazquez, I.; Poggi Varaldo, H. M.

2009-07-01

In the last 10 years, interest on bio hydrogen has resurrected, particularly the research on dark fermentation of solid wastes. In effect, in a context of scarce and expensive fossil fuels, hydrogen can be considered the best energy alternative because it can be produced by biological means, it has the highest energy density, it is versatile since can be used both as a primary or secondary energy source, it is compatible with electrochemical and combustion-based energy conversion processes, and it is environmentally-friendly since water is its main combustion product and no aggressive pollutants are generated. (Author)

Study of Mg-based materials to be used in a functional solid state hydrogen reservoir for vehicular applications

Energy Technology Data Exchange (ETDEWEB)

Maddalena, Amedeo; Petris, Milo; Palade, Petru; Sartori, Sabrina; Principi, Giovanni [Settore Materiali and CNISM, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy); Settimo, Eliseo [Celco-Profil, via dell' Artigianato 4, 30030 Vigonovo (Venezia) (Italy); Molinas, Bernardo [Venezia Tecnologie, via delle Industrie 39, 30175 Marghera (Venezia) (Italy); Lo Russo, Sergio [Dipartimento di Fisica and CNISM, Universita di Padova, via Marzolo 8, 35131 Padova (Italy)

2006-11-15

Powders mixtures of nanosized MgH{sub 2} and suitable additives, obtained by high energy milling, have been studied as materials to be used in a functional solid state hydrogen reservoir. A prototype of a two stages reservoir is under development (patent pending). The hydrogen release from the main stage, with high capacity Mg-based hydrides, is primed by a primer stage containing commercial hydrides able to operate at room temperature. (author)

Shape-dependent hydrogen-storage properties in Pd nanocrystals: which does hydrogen prefer, octahedron (111) or cube (100)?

Science.gov (United States)

Li, Guangqin; Kobayashi, Hirokazu; Dekura, Shun; Ikeda, Ryuichi; Kubota, Yoshiki; Kato, Kenichi; Takata, Masaki; Yamamoto, Tomokazu; Matsumura, Syo; Kitagawa, Hiroshi

2014-07-23

Pd octahedrons and cubes enclosed by {111} and {100} facets, respectively, have been synthesized for investigation of the shape effect on hydrogen-absorption properties. Hydrogen-storage properties were investigated using in situ powder X-ray diffraction, in situ solid-state (2)H NMR and hydrogen pressure-composition isotherm measurements. With these measurements, it was found that the exposed facets do not affect hydrogen-storage capacity; however, they significantly affect the absorption speed, with octahedral nanocrystals showing the faster response. The heat of adsorption of hydrogen and the hydrogen diffusion pathway were suggested to be dominant factors for hydrogen-absorption speed. Furthermore, in situ solid-state (2)H NMR detected for the first time the state of (2)H in a solid-solution (Pd + H) phase of Pd nanocrystals at rt.

Solid-State Hydrogen Storage

Data.gov (United States)

National Aeronautics and Space Administration — This project will develop a method for converting metals to metal hydrides at low pressures for hydrogen storage systems with high efficiency with respect to volume...

Repeating pneumatic hydrogen pellet injector for plasma fueling

International Nuclear Information System (INIS)

Combs, S.K.; Milora, S.L.; Foust, C.R.; Foster, C.A.; Schuresko, D.D.

1985-01-01

A repeating pneumatic pellet injector has been developed for plasma fueling applications. The repetitive device extends pneumatic injector operation to steady state. The active mechanism consists of an extruder and a gun assembly that are cooled by flowing liquid-helium refrigerant. The extruder provides a continuous supply of solid hydrogen to the gun assembly, where a reciprocating gun barrel forms and chambers cylindrical pellet from the extrusion; pellets are then accelerated with compressed hydrogen gas (pressures up to 125 bar) to velocities -1 have been obtained with 2.1- , 3.4- , and 4.0-mm-diameter pellets. The present apparatus operates at higher firing rates in short bursts; for example, a rate of 6 s -1 for 2 s with the larger pellets. These pellet parameters are in the range applicable for fueling large present-day fusion devices such as the Tokamak Fusion Test Reactor (TFTR). Experimental results are presented, including effects of propellant pressure and barrel length on gun performance

Quantitative analysis of hydrogen and hydrogen isotopes at the solid surface

International Nuclear Information System (INIS)

Trocellier, P.

2007-01-01

Because of the importance of the effects bound to the hydrogen presence in materials it is particularly important to determine with accuracy the surface and volume distribution of hydrogen. Meanwhile the electronic structure of the hydrogen (one electron) do not allow to use many characterization techniques as the electrons spectroscopies or the X micro analysis. The author presents other possible techniques. (A.L.B.)

Analysis of the compressive behaviour of the three-dimensional printed porous titanium for dental implants using a modified cellular solid model.

Science.gov (United States)

Gagg, Graham; Ghassemieh, Elaheh; Wiria, Florencia E

2013-09-01

A set of cylindrical porous titanium test samples were produced using the three-dimensional printing and sintering method with samples sintered at 900 °C, 1000 °C, 1100 °C, 1200 °C or 1300 °C. Following compression testing, it was apparent that the stress-strain curves were similar in shape to the curves that represent cellular solids. This is despite a relative density twice as high as what is considered the threshold for defining a cellular solid. As final sintering temperature increased, the compressive behaviour developed from being elastic-brittle to elastic-plastic and while Young's modulus remained fairly constant in the region of 1.5 GPa, there was a corresponding increase in 0.2% proof stress of approximately 40-80 MPa. The cellular solid model consists of two equations that predict Young's modulus and yield or proof stress. By fitting to experimental data and consideration of porous morphology, appropriate changes to the geometry constants allow modification of the current models to predict with better accuracy the behaviour of porous materials with higher relative densities (lower porosity).

Solid NMR characterization of hydrogen solid storage matrices; Caracterisation par RMN du solide des matrices de stockage solide de l'hydrogene

Energy Technology Data Exchange (ETDEWEB)

Pilette, M.A.; Charpentier, T.; Berthault, P. [CEA Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, Lab. de Structure et Dynamique par Resonance Magnetique Lab. Claude Frejacques - CEA/CNRS URA 331, DSM/DRECAM/SCM, 91 - Gif sur Yvette (France)

2007-07-01

The aim of this work is to develop and validate characterization tools by NMR imagery and spectroscopy of the structure of materials for hydrogen storage, and of their evolution during load/unload cycles. The two main topics of this work are in one hand the analysis of the local structure of the materials and the understanding of their eventual modifications, and in another hand, the in-situ analysis of the distribution and diffusion of hydrogen inside the storage material. (O.M.)

Flow design and simulation of a gas compression system for hydrogen fusion energy production

Energy Technology Data Exchange (ETDEWEB)

Avital, E J; Salvatore, E [School of Engineering and Materials Science, Queen Mary University of London, Mile End Rd London E1 4NS (United Kingdom); Munjiza, A [Civil Engineering, University of Split, Livanjska 2100 Split (Croatia); Suponitsky, V; Plant, D; Laberge, M, E-mail: e.avital@qmul.ac.uk [General Fusion Inc.,108-3680 Bonneville Place, Burnaby, BC V3N 4T5 (Canada)

2017-08-15

An innovative gas compression system is proposed and computationally researched to achieve a short time response as needed in engineering applications such as hydrogen fusion energy reactors and high speed hammers. The system consists of a reservoir containing high pressure gas connected to a straight tube which in turn is connected to a spherical duct, where at the sphere’s centre plasma resides in the case of a fusion reactor. Diaphragm located inside the straight tube separates the reservoir’s high pressure gas from the rest of the plenum. Once the diaphragm is breached the high pressure gas enters the plenum to drive pistons located on the inner wall of the spherical duct that will eventually end compressing the plasma. Quasi-1D and axisymmetric flow formulations are used to design and analyse the flow dynamics. A spike is designed for the interface between the straight tube and the spherical duct to provide a smooth geometry transition for the flow. Flow simulations show high supersonic flow hitting the end of the spherical duct, generating a return shock wave propagating upstream and raising the pressure above the reservoir pressure as in the hammer wave problem, potentially giving temporary pressure boost to the pistons. Good agreement is revealed between the two flow formulations pointing to the usefulness of the quasi-1D formulation as a rapid solver. Nevertheless, a mild time delay in the axisymmetric flow simulation occurred due to moderate two-dimensionality effects. The compression system is settled down in a few milliseconds for a spherical duct of 0.8 m diameter using Helium gas and a uniform duct cross-section area. Various system geometries are analysed using instantaneous and time history flow plots. (paper)

Flow design and simulation of a gas compression system for hydrogen fusion energy production

Science.gov (United States)

Avital, E. J.; Salvatore, E.; Munjiza, A.; Suponitsky, V.; Plant, D.; Laberge, M.

2017-08-01

An innovative gas compression system is proposed and computationally researched to achieve a short time response as needed in engineering applications such as hydrogen fusion energy reactors and high speed hammers. The system consists of a reservoir containing high pressure gas connected to a straight tube which in turn is connected to a spherical duct, where at the sphere’s centre plasma resides in the case of a fusion reactor. Diaphragm located inside the straight tube separates the reservoir’s high pressure gas from the rest of the plenum. Once the diaphragm is breached the high pressure gas enters the plenum to drive pistons located on the inner wall of the spherical duct that will eventually end compressing the plasma. Quasi-1D and axisymmetric flow formulations are used to design and analyse the flow dynamics. A spike is designed for the interface between the straight tube and the spherical duct to provide a smooth geometry transition for the flow. Flow simulations show high supersonic flow hitting the end of the spherical duct, generating a return shock wave propagating upstream and raising the pressure above the reservoir pressure as in the hammer wave problem, potentially giving temporary pressure boost to the pistons. Good agreement is revealed between the two flow formulations pointing to the usefulness of the quasi-1D formulation as a rapid solver. Nevertheless, a mild time delay in the axisymmetric flow simulation occurred due to moderate two-dimensionality effects. The compression system is settled down in a few milliseconds for a spherical duct of 0.8 m diameter using Helium gas and a uniform duct cross-section area. Various system geometries are analysed using instantaneous and time history flow plots.

Experimental heat capacity of solid hydrogen as a function of molar volume

International Nuclear Information System (INIS)

Krause, J.K.

1978-01-01

Constant volume heat capacity measurements have been made on six solid hydrogen samples with low orthohydrogen concentrations. The measurements extend from approximately 1.5 K to the melting line, with molar volumes ranging from 22.787 cm 3 /mole to 16.193 cm 3 /mole. Although clustering of the ortho molecules was observed, the low temperature heat capacity anomaly due to the orthohydrogen pairs could be described quite well by the assumption of a fixed distribution. The data were corrected to obtain a lattice heat capacity which on extrapolation to T = 0 yielded Debye temperatures and a volume dependent Grueneisen parameter. A modified Mie-Grueneisen approximation was used to define a volume and temperature dependent Grueneisen parameter which was used to calculate the equation of state, P(V,T), and isothermal bulk modulus, B/sub T/(V,T), for the six isochores. An extrapolation of the equation of state to T = 0 and P = 0 by two different methods yields a molar volume which, when compared with other determinations, gives a recommended value of 23.20 +- 0.05 cm 3 /mole. A rapid increase in the conversion rate of orthohydrogen to parahydrogen was observed at approximately theta/sub o/12. The molar volumes along the melting curve also have been determined directly for the first time in this volume range. These results have been used to show that a low temperature Lindemann melting relation is only approximately valid for solid hydrogen to 50 K

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-12-01

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

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

Directory of Open Access Journals (Sweden)

Shahid Imran

2015-09-01

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

Boron-Based Hydrogen Storage: Ternary Borides and Beyond

Energy Technology Data Exchange (ETDEWEB)

Vajo, John J. [HRL Laboratories, LLC, Malibu, CA (United States)

2016-04-28

DOE continues to seek reversible solid-state hydrogen materials with hydrogen densities of ≥11 wt% and ≥80 g/L that can deliver hydrogen and be recharged at moderate temperatures (≤100 °C) and pressures (≤100 bar) enabling incorporation into hydrogen storage systems suitable for transportation applications. Boron-based hydrogen storage materials have the potential to meet the density requirements given boron’s low atomic weight, high chemical valance, and versatile chemistry. However, the rates of hydrogen exchange in boron-based compounds are thus far much too slow for practical applications. Although contributing to the high hydrogen densities, the high valance of boron also leads to slow rates of hydrogen exchange due to extensive boron-boron atom rearrangements during hydrogen cycling. This rearrangement often leads to multiple solid phases occurring over hydrogen release and recharge cycles. These phases must nucleate and react with each other across solid-solid phase boundaries leading to energy barriers that slow the rates of hydrogen exchange. This project sought to overcome the slow rates of hydrogen exchange in boron-based hydrogen storage materials by minimizing the number of solid phases and the boron atom rearrangement over a hydrogen release and recharge cycle. Two novel approaches were explored: 1) developing matched pairs of ternary borides and mixed-metal borohydrides that could exchange hydrogen with only one hydrogenated phase (the mixed-metal borohydride) and only one dehydrogenated phase (the ternary boride); and 2) developing boranes that could release hydrogen by being lithiated using lithium hydride with no boron-boron atom rearrangement.

Hydrogen-induced room-temperature plasticity in TC4 and TC21 alloys

DEFF Research Database (Denmark)

Yuan, Baoguo; Jin, Yongyue; Hong, Chuanshi

2017-01-01

In order to reveal the effect of hydrogen on the room-temperature plasticity of the titanium alloys TC4 and TC21, compression tests have been carried out at room temperature. Results show that an appropriate amount of hydrogen can improve the room-temperature plasticity of both the TC4 and TC21...... alloys. The ultimate compression strain of the TC4 alloy containing a hydrogen concentration of 0.5 wt.% increases by 39% compared to the untreated material. For the TC21 alloy the ultimate compression strain is increased by 33% at a hydrogen concentration of 0.6 wt.%. The main reason for the improvement...... of hydrogen-induced room-temperature plasticity of the TC4 and TC21 alloys is discussed....

Comparative study about hydrogen sorption in sponge and powder titanium

International Nuclear Information System (INIS)

Vasut, Felicia; Preda, Anisoara; Zamfirache, Marius; Ducu, Catalin; Malinovschi, Viorel

2005-01-01

Currently, hydrogen may be stored as a compressed gas or a cryogenic liquid. Neither method appears to be practical for many applications in which hydrogen use would otherwise be attractive. For example, gaseous storage of stationary fuel is not feasible because of the large volume or weight of the storage vessels. Liquid hydrogen could be use extensively but the liquefaction process is relatively expensive. The hydrogen can be stored for a long term with a high separation factor, as a solid metal hydride. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system, can solve many problems arising in the nuclear-fuel cycle. The paper presents a comparative study about hydrogen sorption on two titanium structures: powder and sponge. Also, it is presented the characterization, by X-Ray diffraction, of two structures, before and after sorption process. From our results, one can conclude that sorption method is efficient for both samples. Kinetic curves indicates that sorption rate for titanium powder is lower than for sponge titanium. This is the effect of reaction surface, which is larger for powder titanium. Sorption capacity for hydrogen is lower in powder titanium for identical experimental conditions. The difference between storage capacities could be explained by activation temperature, which was lower for titanium powder than for sponge. (authors)

Hydrogen-Assisted IC Engine Combustion as a Route to Hydrogen Implementation

Energy Technology Data Exchange (ETDEWEB)

Andre Boehman; Daniel Haworth

2008-09-30

The 'Freedom Car' Initiative announced by the Bush Administration has placed a significant emphasis on development of a hydrogen economy in the United States. While the hydrogen-fueled fuel-cell vehicle that is the focus of the 'Freedom Car' program would rely on electrochemical energy conversion, and despite the large amount of resources being devoted to its objectives, near-term implementation of hydrogen in the transportation sector is not likely to arise from fuel cell cars. Instead, fuel blending and ''hydrogen-assisted'' combustion are more realizable pathways for wide-scale hydrogen utilization within the next ten years. Thus, a large potential avenue for utilization of hydrogen in transportation applications is through blending with natural gas, since there is an existing market for natural-gas vehicles of various classes, and since hydrogen can provide a means of achieving even stricter emissions standards. Another potential avenue is through use of hydrogen to 'assist' diesel combustion to permit alternate combustion strategies that can achieve lower emissions and higher efficiency. This project focused on developing the underlying fundamental information to support technologies that will facilitate the introduction of coal-derived hydrogen into the market. Two paths were envisioned for hydrogen utilization in transportation applications. One is for hydrogen to be mixed with other fuels, specifically natural gas, to enhance performance in existing natural gas-fueled vehicles (e.g., transit buses) and provide a practical and marketable avenue to begin using hydrogen in the field. A second is to use hydrogen to enable alternative combustion modes in existing diesel engines, such as homogeneous charge compression ignition, to permit enhanced efficiency and reduced emissions. Thus, this project on hydrogen-assisted combustion encompassed two major objectives: (1) Optimization of hydrogen-natural gas mixture

41 CFR 50-204.68 - Hydrogen.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Hydrogen. 50-204.68..., Vapors, Fumes, Dusts, and Mists § 50-204.68 Hydrogen. The in-plant transfer, handling, storage, and utilization of hydrogen shall be in accordance with Compressed Gas Association Pamphlets G-5.1-1961 and G-5.2...

The terminal solid solubility of hydrogen and deuterium in Zr-2.5Nb alloys

Energy Technology Data Exchange (ETDEWEB)

Ritchie, I G; Pan, Z L; Puls, M P [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1997-02-01

The presence of hydrides in zirconium based alloys is an important factor in assessing the potential for delayed hydride cracking in pressure tubes and the embrittlement of other in-core components fabricated from these alloys. Consequently, the terminal solid solubility (TSS) of hydrogen in the zirconium alloys used in the Nuclear Industry is an important parameter. However, at the low hydrogen concentrations found in practice, the TSS is difficult to measure accurately and even the measurements of hydrogen concentrations by standard techniques are notoriously difficult to make reproducibly at the nominal levels found in pressure tube materials. The presence of hydrides, their dissolution and nucleation gives rise to a number of internal friction phenomena and changes in Young`s modulus that can be useful from the practical point of view. These phenomena can be used to establish expressions for the TSS as a function of temperature, the hysteresis between dissolution and nucleation and hydrogen supercharging from the gas phase. In particular, such studies show that the hysteresis between the TSS measured during heating and cooling is particularly sensitive to the thermal history of the sample. This paper reviews the phenomena involved and presents some recent results on Zr-2.5Nb pressure tube material. (author). 28 refs, 17 figs, 6 tabs.

Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103

NARCIS (Netherlands)

Callini, Elsa; Aguey-Zinsou, Kondo Francois; Ahuja, Rajeev; Ares, Jos Ramon; Bals, Sara; Biliskov, Nikola; Chakraborty, Sudip; Charalambopoulou, Georgia; Chaudhary, Anna Lisa; Cuevas, Fermin; Dam, Bernard; de Jongh, Petra; Dornheim, Martin; Filinchuk, Yaroslav; Novakovic, Jasmina G.; Hirscher, Michael; Hirscher, M.; Jensen, Torben R.; Jensen, Peter Bjerre; Novakovic, Nikola; Lai, Qiwen; Leardini, Fabrice; Gattia, Daniele Mirabile; Pasquini, Luca; Steriotis, Theodore; Turner, Stuart; Vegge, Tejs; Zuttel, Andreas; Montone, Amelia

2016-01-01

In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated

Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP1103

DEFF Research Database (Denmark)

Callini, Elsa; Aguey-Zinsou, Kondo-Francois; Ahuja, Rajeev

2016-01-01

In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated...

Analysis of hydrogen content and distribution in hydrogen storage alloys using neutron radiography

International Nuclear Information System (INIS)

Sakaguchi, Hiroki; Hatakeyama, Keisuke; Satake, Yuichi; Esaka, Takao; Fujine, Shigenori; Yoneda, Kenji; Kanda, Keiji

2000-01-01

Small amounts of hydrogen in hydrogen storage alloys, such as Mg 2 Ni, were detected using neutron radiography (NRG). Hydrogen concentrations in a hydrogenated solid solution were determined by this technique. Furthermore, we were able to obtain NRG images for an initial stage of hydrogen absorption in the hydrogen storage alloys. NRG would be a new measurement method to clarify the behavior of hydrogen in hydrogen storage alloys. (author)

Arsenolite: a quasi-hydrostatic solid pressure-transmitting medium

International Nuclear Information System (INIS)

Sans, J A; Manjón, F J; Popescu, C; Muñoz, A; Rodríguez-Hernández, P; Jordá, J L; Rey, F

2016-01-01

This study reports the experimental characterization of the hydrostatic properties of arsenolite (As 4 O 6 ), a molecular solid which is one of the softest minerals in the absence of hydrogen bonding. The high compressibility of arsenolite and its stability up to 15 GPa have been proved by x-ray diffraction measurements, and the progressive loss of hydrostaticity with increasing pressure up to 20 GPa has been monitored by ruby photoluminescence. Arsenolite has been found to exhibit hydrostatic behavior up to 2.5 GPa and a quasi-hydrostatic behavior up to 10 GPa at room temperature. This result opens the way to explore other molecular solids as possible quasi-hydrostatic pressure-transmitting media. The validity of arsenolite as an insulating, stable, non-penetrating and quasi-hydrostatic medium is explored by the study of the x-ray diffraction of zeolite ITQ-29 at high pressure. (paper)

Anisotropic intermolecular interactions and rotational ordering in hydrogen containing solids. Final report, January 1, 1972--June 30, 1978

International Nuclear Information System (INIS)

White, D.

1978-01-01

Thermodynamic properties, order-disorder phenomena, optical, electric and magnetic properties of hydrogen-containing molecular solids have been investigated. A summary of the findings of this 6 year research program is presented here. The approach in these studies was (a) thermodynamic and transport studies extending to very low temperatures, (b) pulsed NMR studies for determination of structural parameters important to spin-lattice relaxation, and (c) pulsed laser studies for the investigation of excitations and energy transfer mechanisms in solids

NMR studies of hydrogen diffusion in hydrogen uranyl phosphate tetrahydrate (HUP)

International Nuclear Information System (INIS)

Metcalfe, K.

1988-01-01

1 H NMR spin-lattice relaxation times, T 1 (Zeeman) and T 1p (rotating frame) and spin-spin relaxation times, T 2 , and 31 P NMR solid-echoes are reported for phase I and II of hydrogen uranyl phosphate tetrahydrate (HUP) at temperatures in the range 200-323 K. The spectral density functions extracted from the measured relaxation times for phases I and II are consistent with a 2D diffusion mechanism for hydrogen motion. 31 P second moments determined from the solid-echoes show that all the hydrogens diffuse rapidly in phase I, and that the hydrogen-bond site nearest to the phosphate oxygen is not occupied in phase II. The mechanism for diffusion in phase II is discussed. 30 refs.; 6 figs.; 2 tabs

The development of a computational platform to design and simulate on-board hydrogen storage systems

DEFF Research Database (Denmark)

Mazzucco, Andrea; Rokni, Masoud

2017-01-01

A computational platform is developed in the Modelica® language within the Dymola™ environment to provide a tool for the design and performance comparison of on-board hydrogen storage systems. The platform has been coupled with an open source library for hydrogen fueling stations to investigate...... the vehicular tank within the frame of a complete refueling system. The two technologies that are integrated in the platform are solid-state hydrogen storage in the form of metal hydrides and compressed gas systems. In this work the computational platform is used to compare the storage performance of two tank...... to a storage capacity four times larger than a tube-in-tube solution of the same size. The volumetric and gravimetric densities of the shell and tube are 2.46% and 1.25% respectively. The dehydriding ability of this solution is proven to withstand intense discharging conditions....

Energetic and economic evaluations on hydrogen storage technologies

Energy Technology Data Exchange (ETDEWEB)

Arca, S.; Di Profio, P.; Germani, R. [Perugia Univ., Perugia (Italy). Centro di Eccellenza Materiali Innovativi Nanostrutturati, Dip. Chimica; Savelli, G.; Cotana, F.; Rossi, F.; Amantini, M. [Universita degli Studi di Perugia, Perugia (Italy). Dipartimento di Ingegneria Industriale, Sezione di Fisica Tecnica

2008-07-01

With the development of the hydrogen economy and fuel cell vehicles, a major technological issue has emerged regarding the storage and delivery of large amounts of hydrogen. Several hydrogen storage methodologies are available while other technologies are being developed aside from the classical compression and liquefaction of hydrogen. A novel technology is also in rapid process, which is based on clathrate hydrates of hydrogen. The features and performances of available storage systems were evaluated in an effort to determine the best technology throughout the hydrogen chain. For each of the storage solutions presented, the key parameters were compared. These key parameters included interaction energy between hydrogen and support; real and practical storage capacity; and specific energy consumption. The paper presented the study methods and discussed hydrogen storage technologies using compressed hydrogen; metal hydrides; liquefied hydrogen; carbon nanotubes; ammonia; and gas hydrates. Carbon dioxide emissions were also evaluated for each storage system analyzed. The paper also presented the worst scenario. It was concluded that a technology based on clathrate hydrates of hydrogen, while being far from optimized, was highly competitive with the classical approaches. 21 refs., 9 figs.

Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

Science.gov (United States)

Savinell, R. F.; Fritts, S. D.

1988-01-01

A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

Hydrogen storage: state-of-the-art and future perspective

International Nuclear Information System (INIS)

Tzimas, E.; Filiou, C.; Peteves, S.D.; Veyret, J.B.

2003-01-01

The EU aims at establishing a sustainable energy supply, able to provide affordable and clean energy without increasing green house gas emissions. Hydrogen and fuel cells are seen by many as key energy system solutions for the 21. century, enabling clean and efficient production of power and heat from a broad range of primary energy sources. To be effective, there is a crucial need for well-coordinated research, development and deployment at European Level. The particular segment of hydrogen storage is one key element of the full hydrogen chain and it must meet a number of challenges before it is introduced into the global energy system. Regarding its energy characteristics, the gravimetric energy density of hydrogen is about three times higher than gasoline, but its energy content per volume is about a quarter. Therefore, the most significant problem for hydrogen (in particular for on-board vehicles) is to store sufficient -amounts of hydrogen. The volumetric energy density of hydrogen can be increased by compression or liquefaction which are both the most mature technologies. Still the energy required for both compression and liquefaction is one element to be properly assessed in considering the different pathways in particular for distribution. As far as on-board vehicle storage is concerned all possible options (compressed, liquid, metal hydrides and porous structures) have their own advantages and disadvantages with respect to weight, volume, energy efficiency, refuelling times, cost and safety aspects. To address these problems, long-term commitments to scientific excellence in research, coupled with co-ordination between the many different stakeholders, is required. In the current state-of-the-art in hydrogen storage, no single technology satisfies all of the criteria required by manufacturers and end-users, and a large number of obstacles have to be overcome. The current hydrogen storage technologies and their associated limitations/needs for improvement

SISGR - Hydrogen Caged in Carbon-Exploration of Novel Carbon-Hydrogen Interactions

Energy Technology Data Exchange (ETDEWEB)

Lueking, Angela [Pennsylvania State Univ., State College, PA (United States); Badding, John [Pennsylvania State Univ., State College, PA (United States); Crespi, Vinent [Pennsylvania State Univ., State College, PA (United States)

2015-12-01

Hydrogen trapped in a carbon cage, captured through repulsive interactions, is a novel concept in hydrogen storage. Trapping hydrogen via repulsive interactions borrows an idea from macroscale hydrogen storage (i.e. compressed gas storage tanks) and reapplies these concepts on the nanoscale in specially designed molecular containers. Under extreme conditions of pressure, hydrogen solubility in carbon materials is expected to increase and carbon is expected to restructure to minimize volume via a mixed sp2/sp3 hydrogenated state. Thermodynamics dictate that pre-formed C-H structures will rearrange with increased pressure, yet the final carbon-hydrogen interactions may be dependent upon the mechanism by which hydrogen is introduced. Gas “trapping” is meant to denote gas present in a solid in a high density, adsorbed-like state, when the external pressure is much less than that necessary to provide a comparable fluid density. Trapping thus denotes a kinetically metastable state rather than thermodynamic equilibrium. This project probed mechanochemical means to polymerize select hydrocarbons in the presence of gases, in an attempt to form localized carbon cages that trap gases via repulsive interactions. Aromatic, polyaromatic, and hydroaromatic molecules expected to undergo cyclo-addition reactions were polymerized at high (~GPa) pressures to form extended hydrogenated amorphous carbon networks. Notably, aromatics with a pre-existing internal free volume (such as Triptycene) appeared to retain an internal porosity upon application of pressure. However, a high photoluminescence background after polymerization precluded in situ identification of trapped gases. No spectroscopic evidence was found after depressurization that would be indicative of pockets of trapped gases in a localized high-pressure environment. Control studies suggested this measurement may be insensitive to gases at low pressure. Similarly, no spectral fingerprint was found for gas-imbued spherical

Indications of the formation of an oversaturated solid solution during hydrogenation of Mg-Ni based nanocomposite produced by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Guzman, D. [Departamento de Ingenieria en Metalurgia, Facultad de Ingenieria, Universidad de Atacama y Centro Regional de Investigacion y Desarrollo Sustentable de Atacama, CRIDESAT, Av. Copayapu 485, Copiapo (Chile); Ordonez, S. [Departamento de Ingenieria Metalurgica, Facultad de Ingenieria, Universidad de Santiago de Chile, Av. Lib. Bernardo O' Higgins 3363, Santiago (Chile); Fernandez, J.F.; Sanchez, C. [Departamento de Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Serafini, D. [Departamento de Fisica, Facultad de Ciencias, Universidad de Santiago de Chile and Center for Interdisciplinary Research in Materials, CIMAT, Av. Lib. Bernardo O' Higgins 3363, Santiago (Chile); Rojas, P.A. [Escuela de Ingenieria Mecanica, Facultad de Ingenieria, Av. Los Carrera 01567, Quilpue, Pontificia Universidad Catolica de Valparaiso, PUCV (Chile); Aguilar, C. [Instituto de Materiales y Procesos Termomecanicos, Facultad de Ciencias de la Ingenieria, Universidad Austral de Chile, Av. General Lagos 2086, Valdivia (Chile)

2009-07-15

An oversaturated solid solution of H in a nanocomposite material formed mainly by nanocrystalline Mg{sub 2}Ni, some residual nanocrystalline Ni and an Mg rich amorphous phase has been found for the first time. The nanocomposite was produced by mechanical alloying starting from Mg and Ni elemental powders, using a SPEX 8000D mill. The hydriding characterization of the nanocomposite was carried out by solid-gas reaction method in a Sievert's type apparatus. The maximum hydrogen content reached in a period of 21 Ks without prior activation was 2.00 wt.% H under hydrogen pressure of 2 MPa at 363 K. The X-ray diffraction analysis showed the presence of an oversaturated solid solution between nanocrystalline Mg{sub 2}Ni and H without any sign of Mg{sub 2}NiH{sub 4} hydride formation. The dehydriding behaviour was studied by differential scanning calorimetry and thermogravimetry. The results showed the existence of two desorption peaks, the first one associated with the transformation of the oversaturated solid solution into Mg{sub 2}NiH{sub 4}, and the second one with the Mg{sub 2}NiH{sub 4} desorption. (author)

In situ x-ray diffraction study of crystal structure of Pd during hydrogen isotope loading by solid-state electrolysis at moderate temperatures 250−300 °C

Energy Technology Data Exchange (ETDEWEB)

Fukada, Yoshiki, E-mail: yoshiki_fukada@mail.toyota.co.jp [Toyota Motor Corporation, 1200 Mishuku, Susono-shi, Shizuoka-ken, 410-1193 (Japan); Hioki, Tatsumi; Motohiro, Tomoyoshi [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan); Green Mobility Collaborative Research Center & Graduate School of Engineering Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan); Ohshima, Shigeki [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan)

2015-10-25

Hydrogen isotopes and metal interaction with respect to Pd under high hydrogen isotope potential at moderate temperature region around 300 °C was studied. A dry electrolysis technique using BaZr{sub 1−x} Y{sub x}O{sub 3} solid state electrolyte was developed to generate high hydrogen isotope potential. Hydrogen or deuterium was loaded into a 200 nm thick Pd cathode. The cathode is deposited on SiO{sub 2} substrate and covered with the solid state electrolyte and a Pd anode layer. Time resolved in situ monochromatic x-ray diffraction measurement was performed during the electrolysis. Two phase states of the Pd cathodes with large and small lattice parameters were observed during the electrolysis. Numerous sub-micron scale voids in the Pd cathode and dendrite-like Pd precipitates in the solid state electrolyte were found from the recovered samples. Hydrogen induced super-abundant-vacancy may take role in those phenomena. The observed two phase states may be attributed to phase separation into vacancy-rich and vacancy-poor states. The voids formed in the Pd cathodes seem to be products of vacancy coalescence. Isotope effects were also observed. The deuterium loaded samples showed more rapid phase changes and more formation of voids than the hydrogen doped samples. - Highlights: • High amount hydrogen loading into Pd by all solid-state electrolysis was performed. • Two phase states with large and small lattice parameters were observed. • Lattice contractions were observed suggesting formations of super-abundant-vacancy. • The absence of mechanical pressure might stimulate the formation of the vacancy. • Sub-micron void formations were found in the Pd from recovered samples.

In situ x-ray diffraction study of crystal structure of Pd during hydrogen isotope loading by solid-state electrolysis at moderate temperatures 250−300 °C

International Nuclear Information System (INIS)

Fukada, Yoshiki; Hioki, Tatsumi; Motohiro, Tomoyoshi; Ohshima, Shigeki

2015-01-01

Hydrogen isotopes and metal interaction with respect to Pd under high hydrogen isotope potential at moderate temperature region around 300 °C was studied. A dry electrolysis technique using BaZr 1−x Y x O 3 solid state electrolyte was developed to generate high hydrogen isotope potential. Hydrogen or deuterium was loaded into a 200 nm thick Pd cathode. The cathode is deposited on SiO 2 substrate and covered with the solid state electrolyte and a Pd anode layer. Time resolved in situ monochromatic x-ray diffraction measurement was performed during the electrolysis. Two phase states of the Pd cathodes with large and small lattice parameters were observed during the electrolysis. Numerous sub-micron scale voids in the Pd cathode and dendrite-like Pd precipitates in the solid state electrolyte were found from the recovered samples. Hydrogen induced super-abundant-vacancy may take role in those phenomena. The observed two phase states may be attributed to phase separation into vacancy-rich and vacancy-poor states. The voids formed in the Pd cathodes seem to be products of vacancy coalescence. Isotope effects were also observed. The deuterium loaded samples showed more rapid phase changes and more formation of voids than the hydrogen doped samples. - Highlights: • High amount hydrogen loading into Pd by all solid-state electrolysis was performed. • Two phase states with large and small lattice parameters were observed. • Lattice contractions were observed suggesting formations of super-abundant-vacancy. • The absence of mechanical pressure might stimulate the formation of the vacancy. • Sub-micron void formations were found in the Pd from recovered samples

Thermally-induced ortho-para conversion anomaly in solid hydrogen under pressure

Energy Technology Data Exchange (ETDEWEB)

Krause, J K; Swenson, C A

1979-01-01

The spontaneous ortho-para conversion rate in solid hydrogen under pressure has been observed to increase by approximately an order of magnitude at temperatures greater than 0.08 theta/sub 0/ and for molar volumes less than 19.7 cm/sup 3/. This effect, which disappears upon cooling below these temperatures, cannot be understood in terms of present theoretical models. The heat capacity experiment (C/sub V/(V,T)) in which these effects were observed gives an equation of state for parahydrogen for pressures less than 2 kbar which agrees with previous high pressure work at 4.2/sup 0/K, and a T=O equilibrium molar volume of 23.20 +- 0.05 cm/sup 3/. 2 figures.

Molecular rotations and diffusion in solids, in particular hydrogen in metals

International Nuclear Information System (INIS)

Springer, T.

1977-01-01

The chapter deals mainly with problems related to physical chemistry. The author treats diffusion in solids, in particular of hydrogen in metals, and studies of molecular rotations, in particular studies of tunneling transitions which is a relatively new and rapidly developing field of high resolution neutron spectroscopy. Typical neutron spectra to be discussed appear in energy ranges of a few 10 -6 to a few 10 -3 eV, or 10 -5 to 10 -2 cm -1 . The discussion is restricted to scattering from the protons which is predominantly incoherent. This means that only the motions, or excitations, of individual protons or protonic groups are discussed, ignoring collective excitations and interference. (HPOE) [de

Recent Progress and New Perspectives on Metal Amide and Imide Systems for Solid-State Hydrogen Storage

Directory of Open Access Journals (Sweden)

Sebastiano Garroni

2018-04-01

Full Text Available Hydrogen storage in the solid state represents one of the most attractive and challenging ways to supply hydrogen to a proton exchange membrane (PEM fuel cell. Although in the last 15 years a large variety of material systems have been identified as possible candidates for storing hydrogen, further efforts have to be made in the development of systems which meet the strict targets of the Fuel Cells and Hydrogen Joint Undertaking (FCH JU and U.S. Department of Energy (DOE. Recent projections indicate that a system possessing: (i an ideal enthalpy in the range of 20–50 kJ/mol H2, to use the heat produced by PEM fuel cell for providing the energy necessary for desorption; (ii a gravimetric hydrogen density of 5 wt. % H2 and (iii fast sorption kinetics below 110 °C is strongly recommended. Among the known hydrogen storage materials, amide and imide-based mixtures represent the most promising class of compounds for on-board applications; however, some barriers still have to be overcome before considering this class of material mature for real applications. In this review, the most relevant progresses made in the recent years as well as the kinetic and thermodynamic properties, experimentally measured for the most promising systems, are reported and properly discussed.

US-guided percutaneous radiofrequency thermal ablation for the treatment of solid benign hyperfunctioning or compressive thyroid nodules.

Science.gov (United States)

Deandrea, Maurilio; Limone, Paolo; Basso, Edoardo; Mormile, Alberto; Ragazzoni, Federico; Gamarra, Elena; Spiezia, Stefano; Faggiano, Antongiulio; Colao, Annamaria; Molinari, Filippo; Garberoglio, Roberto

2008-05-01

The aim of the study was to define the effectiveness and safety of ultrasound-guided percutaneous radiofrequency (RF) thermal ablation in the treatment of compressive solid benign thyroid nodules. Thirty-one patients not eligible for surgery or radioiodine (131I) treatment underwent RF ablation for benign nodules; a total of 33 nodules were treated (2 patients had 2 nodules treated in the same session): 10 cold nodules and 23 hyperfunctioning. Fourteen patients complained of compressive symptoms. Nodule volume, thyroid function and compressive symptoms were evaluated before treatment and at 1, 3 and 6 mo. Ultrasound-guided RF ablation was performed using a Starbust RITA needle, with nine expandable prongs; total exposure time was 6 to 10 min at 95 degrees C in one area or more of the nodule. Baseline volume (measured at the time of RF ablation) was 27.7 +/- 21.5 mL (mean +/- SD), but significantly decreased during follow-up: 19.2 +/- 16.2 at 1 mo (-32.7%; p nodules remained euthyroid: five patients with hot nodules normalized thyroid function, and the remaining sixteen showed a partial remission of hyperthyroidism. Besides a sensation of heat and mild swelling of the neck, no major complications were observed. Improvement in compressive symptoms was reported by 13 patients, with a reduction on severity scale from 6.1 +/- 1.4 to 2.2 +/- 1.9 (p nodules. Hyperfunction was fully controlled in 24% of patients and partially reduced in the others.

Hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte

Energy Technology Data Exchange (ETDEWEB)

Kilic, Ebru Oender [KOSGEB Bursa Business Development Center, Besevler Kucuk Sanayi Sitesi 16149 Nilufer/Bursa (Turkey); Koparal, Ali Savas; Oeguetveren, Uelker Bakir [Anadolu University, Iki Eylul Campus, Applied Research Center for Environmental Problems 26555 Eskisehir (Turkey); Anadolu University, Iki Eylul Campus, Department of Environmental Engineering, 26555 Eskisehir (Turkey)

2009-01-15

The aim of this work is to investigate the feasibility of simultaneous hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte (SPE) in an electrochemical reactor. Titanium oxide coated with iridium oxide as anode and carbon fibre with Pt catalyst as cathode were used in the experiments. Effects of applied current density, flow rates and temperature of formic acid solution, concentration of supporting electrolyte and pH of the solution on performance of the process have been investigated. The effect of membrane thickness has also been examined. The results suggest that electrolysis using SPE is a promising method for the treatment of organic pollutants. Hydrogen with purity of 99.999% at ambient temperature by using carbon fibre cathode with Pt catalyst can be produced simultaneously and COD removal efficiency of 95% has been achieved not requiring any chemical addition and temperature increase. Also complete electrochemical oxidation of formic acid at the original pH to CO{sub 2} and H{sub 2}O without production of intermediate has been proved by HPLC analysis. (author)

Modelling dewatering behaviour through an understanding of solids formation processes. Part II--solids separation considerations.

Science.gov (United States)

Dustan, A C; Cohen, B; Petrie, J G

2005-05-30

An understanding of the mechanisms which control solids formation can provide information on the characteristics of the solids which are formed. The nature of the solids formed in turn impacts on dewatering behaviour. The 'upstream' solids formation determines a set of suspension characteristics: solids concentration, particle size distribution, solution ionic strength and electrostatic surface potential. These characteristics together define the suspension's rheological properties. However, the complicated interdependence of these has precluded the prediction of suspension rheology from such a fundamental description of suspension characteristics. Recent shear yield stress models, applied in this study to compressive yield, significantly reduce the empiricism required for the description of compressive rheology. Suspension compressibility and permeability uniquely define the dewatering behaviour, described in terms of settling, filtration and mechanical expression. These modes of dewatering may be described in terms of the same fundamental suspension mechanics model. In this way, it is possible to link dynamically the processes of solids formation and dewatering of the resultant suspension. This, ultimately, opens the door to improved operability of these processes. In part I of this paper we introduced an integrated system model for solids formation and dewatering. This model was demonstrated for the upstream processes using experimental data. In this current paper models of colloidal interactions and dewatering are presented and compared to experimental results from batch filtration tests. A novel approach to predicting suspension compressibility and permeability using a single test configuration is presented and tested.

Development of a new reduced hydrogen combustion mechanism with NO_x and parametric study of hydrogen HCCI combustion using stochastic reactor model

International Nuclear Information System (INIS)

Maurya, Rakesh Kumar; Akhil, Nekkanti

2017-01-01

Highlights: • PDF based stochastic reactor model used for study of hydrogen HCCI engine. • New reduced hydrogen combustion mechanism with NOx developed (30 species and 253 reactions). • Mechanism predicts cylinder pressure and captures NO_x emission trend with sufficient accuracy. • Parametric study of hydrogen HCCI engine over wide range of speed and load conditions. • Hydrogen HCCI operating range increases with compression ratio & decreases with engine speed. - Abstract: Hydrogen is a potential alternative and renewable fuel for homogenous charge compression ignition (HCCI) engine to achieve higher efficiency and zero emissions of CO, unburned hydrocarbons as well as other greenhouse gases such as CO_2 and CH_4. In this study, a detailed hydrogen oxidation mechanism with NO_x was developed by incorporating additional species and NO_x reactions to the existing hydrogen combustion mechanism (10 species and 40 reactions). The detailed hydrogen combustion mechanism used in this study consists of 39 species and 311 reactions. A reduced mechanism consisting 30 species and 253 reactions was also developed by using directed relation graph (DRG) method from detailed mechanism. Developed mechanisms were validated with experimental data by HCCI engine simulation using stochastic reactor model. Sensitivity analysis was performed to identify the most important reactions in hydrogen combustion and NO_x formation in HCCI engine. Pathway analysis was also performed to analyze the important reaction pathways at different temperatures. Results revealed that H2 + HO2 [=] H + H2O2 and O2 + NNH [=] N2 + HO2 are the most significant reactions in the hydrogen HCCI combustion and NO_x formation respectively. Detailed parametric study of HCCI combustion was conducted using developed chemical kinetic model. Numerical simulations are performed at different engine operating condition by varying engine speed (1000–3000 rpm), intake air temperature (380–460 K), and compression

Hydrogen plant module (HPM) and vehicle fueled by same.

Science.gov (United States)

2011-09-29

The goal / objective of the project was to design and fabricate hydrogen plant module (HPM) that is capable of producing : hydrogen fuel onboard a vehicle and that obviates one or more of the present issues related to compressed hydrogen fuel : stora...

Hydrogen charging/discharging system with liquid organic compounds: a lacunar oxide catalyst to hydrogenate the unsaturated organic compound

International Nuclear Information System (INIS)

Jalowiecki-Duhamel, L.; Carpentier, J.; Payen, E.; Heurtaux, F.

2006-01-01

Lacunar mixed oxides based on cerium nickel and aluminium or zirconium CeM 0.5 Ni x O y s (M = Zr or Al), able to store high quantities of hydrogen, have been analysed in the hydrogenation of toluene into methyl-cyclohexane (MCH). When these solids present very good toluene hydrogenation activity and selectivity towards MCH in presence of H 2 , in absence of gaseous hydrogen, the reactive hydrogen species stored in the solid can hydrogenate toluene into MCH. The hydrogenation activity under helium + toluene flow decreases as a function of time and becomes nil. The integration of the curve obtained allows to determine the extractable hydrogen content of the solid used, and a value of 1.2 wt % is obtained at 80 C on a CeAl 0.5 Ni 3 O y compound pre-treated in H 2 at 300 C. To optimise the system, different parameters have been analysed, such as the catalyst formulation, the metal content, the pre-reducing conditions as well as the reaction conditions under helium + toluene. (authors)

Optimising hydrogen bonding in solid wood

DEFF Research Database (Denmark)

Engelund, Emil Tang

2009-01-01

The chemical bonds of wood are both covalent bonds within the wood polymers and hydrogen bonds within and between the polymers. Both types of bonds are responsible for the coherence, strength and stiffness of the material. The hydrogen bonds are more easily modified by changes in load, moisture...... and temperature distorting the internal bonding state. A problem arises when studying hydrogen bonding in wood since matched wood specimens of the same species will have very different internal bonding states. Thus, possible changes in the bonding state due to some applied treatment such as conditioning...... maintaining 100 % moisture content of the wood. The hypothesis was that this would enable a fast stress relaxation as a result of reorganization of bonds, since moisture plasticizes the material and temperature promotes faster kinetics. Hereby, all past bond distortions caused by various moisture, temperature...

Development of tantalum–zirconium alloy for hydrogen purification

Energy Technology Data Exchange (ETDEWEB)

Kumar, Sanjay, E-mail: sanjay.barc@gmail.com [Fusion Reactor Materials Section, MG, BARC, Mumbai 85 (India); IAMR, Hiroshima University, Higashihiroshima 739-8530 (Japan); Singh, Anamika [GSASM Hiroshima University, Higashihiroshima 739-8530 (Japan); Jain, Uttam; Dey, Gautam Kumar [Fusion Reactor Materials Section, MG, BARC, Mumbai 85 (India)

2016-11-01

Highlights: • Terminal solid solubility of Ta increases with Zr addition. • Increase in lattice parameters of Ta due to Zr addition may be the possible reason. • Enhance H solubility could also be explained on the change in e-DOS of Ta–Zr alloys. • Ta–Zr alloys could be possible combination for hydrogen purification membrane. - Abstract: Terminal solid solubility of hydrogen in Ta–Zr alloys has been studied in connection with the development of tantalum based metallic membrane for hydrogen/tritium purification. The alloys were prepared by vacuum arc melting technique and subsequently cold rolled to 0.2 mm thickness. The terminal solid solubility of hydrogen in these cold rolled samples was investigated in a modified Sieverts apparatus. The terminal solid solubility of hydrogen was marginally increased with zirconium content. The change in the lattices parameter of tantalum upon zirconium addition and the higher affinity of zirconium for hydrogen as compared to tantalum could be the possible reasons.

Photocatalytic hydrogen production over solid solutions between BiFeO{sub 3} and SrTiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Lu, Lingwei; Lv, Meilin [Shanghai Key Lab of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, 1239 Siping Road, Shanghai, 200092 (China); Liu, Gang [Shenyang National laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 72 Wenhua Road, Shenyang 110016 (China); Xu, Xiaoxiang, E-mail: xxxu@tongji.edu.cn [Shanghai Key Lab of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, 1239 Siping Road, Shanghai, 200092 (China)

2017-01-01

Graphical abstract: We have successfully prepared a series of SrTiO{sub 3}-BiFeO{sub 3} solid solutions. These materials own strong visible light absorption and demonstrate appealing photocatalytic activity under both full range and visible light irradiation. - Highlights: • Band gap values can be tuned by adjusting molar ratios between SrTiO{sub 3} and BiFeO{sub 3}. • Photocatalytic activity is greatly improved after constituting solid solutions. • Photocatalytic activity is influenced by surface area and light absorption. • Fe plays an important role for band gap reduction and catalytic activity. - Abstract: Constituting solid solutions has been an appealing means to gain control over various physicochemical properties. In this work, we synthesized a series of SrTiO{sub 3}-BiFeO{sub 3} solid solutions and systematically explored their structural, optical and photocatalytic properties. Our results show that all solid solutions crystallize in a primitive cubic structure and their band gap values can be easily tuned by adjusting molar ratios between SrTiO{sub 3} and BiFeO{sub 3}. Photocatalytic hydrogen production under both full range and visible light irradiation is greatly improved after forming solid solutions. The highest hydrogen production rate obtained is ∼180 μmol/h under full range irradiation (λ ≥ 250 nm) and ∼4.2 μmol/h under visible light irradiation (λ ≥ 400 nm), corresponding to apparent quantum efficiency ∼2.28% and ∼0.10%, respectively. The activity is found to be strongly influenced by surface area and light absorption. Theoretical calculation suggests that Fe contributes to the formation of spin-polarized bands in the middle of original band gap and is responsible for the band gap reduction and visible light photocatalytic activity.

Hydrogen energy and sustainability: overview and the role for nuclear energy

International Nuclear Information System (INIS)

Rosen, M.A.

2008-01-01

This paper discusses the role of nuclear power in hydrogen energy and sustainability. Hydrogen economy is based on hydrogen production, packaging (compression, liquefaction, hydrides), distribution (pipelines, road, rail, ship), storage (pressure and cryogenic containers), transfer and finally hydrogen use

Machine for compacting solid residues

International Nuclear Information System (INIS)

Herzog, J.

1981-11-01

Machine for compacting solid residues, particularly bulky radioactive residues, constituted of a horizontally actuated punch and a fixed compression anvil, in which the residues are first compacted horizontally and then vertically. Its salient characteristic is that the punch and the compression anvil have embossments on the compression side and interpenetrating plates in the compression position [fr

Reaction of hydrogen atoms produced by radiolysis and photolysis in solid phase at 4 and 77 K

International Nuclear Information System (INIS)

Miyazaki, Tetsuo

1991-01-01

The behavior of H atoms in the solid phase has been reviewed with special attention to comparison of H atoms produced by radiolysis with those produced by photolysis. The paper consists of three parts. I -Production of H atoms: (1) the experimental results which indicate H-atom formation in the radiolysis of solid alkane are summarized; (2) ESR saturation behavior of trapped H atoms depends upon the method of H-atom-production, i.e. photolysis or radiolysis, and upon the initial energy of H atoms in the photolysis. II - Diffusion of H atoms: (1) activation energies for thermally-activated diffusion of H atoms are shown; (2) quantum diffusion of H atoms in solid H 2 is explained in terms of repetition of tunneling reaction H 2 + H → H + H 2 . III -Reaction of H atoms: (1) reactions and trapping processes of hot H atoms have been shown in solid methane and argon by use of hot H atoms with specified initial energy; (2) when H atoms are produced by the radiolysis of solvent alkane or by the photolysis of HI in the alkane mixtures at 77 K, the H atoms react very selectively with solute alkane at low concentration. The selective reaction of the H atom has been found in eight matrices; (3) activation energy for a hydrogen-atom-abstraction reaction by thermal H atoms at low temperatures is less than than several kJ mol -1 because of quantum tunneling. The absolute rate constants for H 2 (D 2 , HD) + H(D) tunneling reactions have been determined experimentally in solid hydrogen at 4.2K; (4) theoretical studies for tunneling reactions H 2 (D 2 ,HD) + H(D) at ultralow temperatures were reviewed. The calculated rate constants were compared with the rate constants obtained experimentally. (author)

Compression Behavior of High Performance Polymeric Fibers

National Research Council Canada - National Science Library

Kumar, Satish

2003-01-01

Hydrogen bonding has proven to be effective in improving the compressive strength of rigid-rod polymeric fibers without resulting in a decrease in tensile strength while covalent crosslinking results in brittle fibers...

A Low-Stress, Elastic, and Improved Hardness Hydrogenated Amorphous Carbon Film

Directory of Open Access Journals (Sweden)

Qi Wang

2015-01-01

Full Text Available The evolution of hydrogenated amorphous carbon films with fullerene-like microstructure was investigated with a different proportion of hydrogen supply in deposition. The results showed at hydrogen flow rate of 50 sccm, the deposited films showed a lower compressive stress (lower 48.6%, higher elastic recovery (higher 19.6%, near elastic recovery rate 90%, and higher hardness (higher 7.4% compared with the films deposited without hydrogen introduction. Structural analysis showed that the films with relatively high sp2 content and low bonded hydrogen content possessed high hardness, elastic recovery rate, and low compressive stress. It was attributed to the curved graphite microstructure, which can form three-dimensional covalently bonded network.

Evaluation of pretreatment methods on harvesting hydrogen producing seeds from anaerobic digested organic fraction of municipal solid waste (OFMSW)

Energy Technology Data Exchange (ETDEWEB)

Dong, Li [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhenhong, Yuan; Yongming, Sun; Longlong, Ma [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

2010-08-15

In order to harvest high-efficient hydrogen producing seeds, five pretreatment methods (including acid, heat, sonication, aeration and freeze/thawing) were performed on anaerobic digested sludge (AS) which was collected from a batch anaerobic reactor for treating organic fraction of municipal solid waste. The hydrogen production tests were conducted in serum bottles containing 20 gVS/L (24.8 g COD/L) mixture of rice and lettuce powder at 37 C. The experimental results showed that the heat and acid pretreatment completely repressed the methanogenic activity of AS, but acid pretreatment also partially repressed hydrogen production. Sonication, freeze/thawing and aeration did not completely suppress the methanogen activity. The highest hydrogen yields were 119.7, 42.2, 26.0, 23.0, 22.7 and 22.1 mL/gVS for heated, acidified, freeze/thawed, aerated, sonicated and control AS respectively. A pH of about 4.9 was detected at the end of hydrogen producing fermentation for all tests. The selection of an initial pH can markedly affect the hydrogen producing ability for heated and acidified AS. The higher initial pH generated higher hydrogen yield and the highest hydrogen yield was obtained with initial pH 8.9 for heated AS. (author)

Effect of Hydrogen and Hydrogen Enriched Compressed Natural Gas Induction on the Performance of Rubber Seed Oil Methy Ester Fuelled Common Rail Direct Injection (CRDi Dual Fuel Engines

Directory of Open Access Journals (Sweden)

Mallikarjun Bhovi

2017-06-01

Full Text Available Renewable fuels are in biodegradable nature and they tender good energy security and foreign exchange savings. In addition they address environmental concerns and socio-economic issues. The present work presents the experimental investigations carried out on the utilization of such renewable fuel combinations for diesel engine applications. For this a single-cylinder four-stroke water cooled direct injection (DI compression ignition (CI engine provided with CMFIS (Conventional Mechanical Fuel Injection System was rightfully converted to operate with CRDi injection systems enabling high pressure injection of Rubber seed oil methyl ester (RuOME in the dual fuel mode with induction of varied gas flow rates of hydrogen and hydrogen enriched CNG (HCNG gas combinations. Experimental investigations showed a considerable improvement in dual fuel engine performance with acceptable brake thermal efficiency and reduced emissions of smoke, hydrocarbon (HC, carbon monoxide (CO and slightly increased nitric oxide (NOx emission levels for increased hydrogen and HCNG flow rates. Further CRDi facilitated dual fuel engine showed improved engine performance compared to CMFIS as the former enabled high pressure (900 bar injection of the RuOME and closer to TDC (Top Dead Centre as well. Combustion parameters such as ignition delay, combustion duration, pressure-crank angle and heat release rates were analyzed and compared with baseline data generated. Combustion analysis showed that the rapid rate of burning of hydrogen and HCNG along with air mixtures increased due to presence of hydrogen in total and in partial combination with CNG which further resulted into higher cylinder pressures and energy release rates. However, sustained research that can provide feasible engine technology operating on such fuels in dual fuel operation can pave the way for continued fossil fuel usage.

Questioning hydrogen

International Nuclear Information System (INIS)

Hammerschlag, Roel; Mazza, Patrick

2005-01-01

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

Comparison of two anaerobic systems for hydrogen production from the organic fraction of municipal solid waste and synthetic wastewater

Energy Technology Data Exchange (ETDEWEB)

Alzate-Gaviria, Liliana M. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico); Perez-Hernandez, Antonino [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31109 (Mexico); Eapen, D. [Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico)

2007-10-15

Two laboratory scale anaerobic digestion systems for hydrogen production from organic fraction of municipal solid waste (OFMSW) and synthetic wastewater were compared in this study. One of them was formed by a coupled packed bed reactor (PBR) containing 19.4 L of OFMSW and the other an upflow anaerobic sludge bed (UASB) of 3.85 L. The reactors were inoculated with a mixture of non-anaerobic inocula. In the UASB the percentage of hydrogen yield reached 51% v/v and 127NmLH{sub 2}/gvs removed with a hydraulic retention time (HRT) of 24 h. The concentration of synthetic wastewater in the affluent was 7 g COD/L. For the PBR the percentage yield was 47% v/v and 99NmLH{sub 2}/gvs removed with a mass retention time (MRT) of 50 days and the organic load rate of 16 gvs (Grams Volatile Solids)/(kg-day). The UASB and PBR systems presented maximum hydrogen yields of 30% and 23%, respectively, which correspond to 4molH{sub 2}/mol glucose. These values are similar to those reported in the literature for the hydrogen yield (37%) in mesophilic range. The acetic and butyric acids were present in the effluent as by-products in watery phase. In this work we used non-anaerobic inocula made up of microorganism consortium unlike other works where pure inocula or that from anaerobic sludge was used. (author)

The hydrogen 700 project - 700 Bar Co

International Nuclear Information System (INIS)

Gambone, L.; Webster, C.

2004-01-01

'Full text:' Major automotive companies, including DaimlerChrysler, Ford, Hyundai, Nissan, PSA Peugeot-Citroen, and Toyota, are co-operating in the Hydrogen 700 project at Powertech to establish a global basis for high pressure hydrogen fuel systems for vehicles. The fuel systems will store compressed hydrogen on-board at pressures up to 700 bar (10,000psi). It is anticipated that the 700 bar storage pressure will provide hydrogen powered vehicles with a range comparable to the range of petroleum-fueled vehicles. The Hydrogen 700 project has contracted world leaders in high pressure technologies to provide 700 bar fuel system components for evaluation. The data from these tests will be used as the basis for the development of relevant standards and regulations. In a development that complements the Hydrogen 700 project, Powertech Labs has established the world's first 700 bar hydrogen station for fast filling operations. This prototype station will be used to evaluate the performance of the 700 bar vehicle fuel system components. The presentation will provide an overview of the Hydrogen 700 project. Safety issues surrounding the use of compressed hydrogen gas as a vehicle fuel, as well as the use of higher storage pressures, will be reviewed. Test data involving the fire testing of vehicles containing hydrogen fuel systems will be presented. The project is intended to result in the introduction of 700 bar fuel systems in the next generation of hydrogen powered vehicles. (author)

Hydrogen pellet injection device

International Nuclear Information System (INIS)

Kanno, Masahiro.

1992-01-01

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

A clean measurement of the hydrogen retardation of the rate of solid phase epitaxy in silicon

International Nuclear Information System (INIS)

Liu, A.C.Y.; McCallum, J.C.

1999-01-01

The rate retarding effects of the impurity hydrogen on solid phase epitaxy (SPE) in silicon have yet to be completely understood. Existing measurements of this behaviour do not coincide exactly, however, several features have attained prominence. Firstly, a linear decrease in the SPE rate is detected up until a certain concentration of hydrogen. Subsequent to this point the rate remains almost constant at around half the intrinsic rate. It is conjectured that the hydrogen bonds to and passivates the defects whose agency enables the incorporation of atoms from the amorphous phase to the crystalline. This rate reduction increases until the defect population is saturated. At this point the reduction in rate ceases. Secondly, a dependence on temperature has not been consolidated, in contrast with the trends observed with the doping species. Here a method is proposed for producing a controlled concentration of hydrogen for the advancing amorphous/crystalline interface to encounter during epitaxy. A bubble layer is formed in crystalline silicon approximately 0.6μm beneath the surface through the implantation of hydrogen at 65 keV with fluences of 4 x 10 16 /cm 2 and 3 x 10 16 /cm 2 and annealing for 1 hour at 850 deg C in dry argon. The anneal doesn't out gas all the introduced hydrogen, leaving a remnant gas pressure in the bubbles. The hydrogen implants at the two fluences should yield two samples with different amounts of hydrogen trapped in the bubbles. A buried amorphous layer is created to encompass the bubble layer containing this residual contaminant through silicon self implantation at appropriate energies and fluences. The progress of the front interface of the buried amorphous layer is monitored by time resolved reflectivity (TRR) as SPE is effected at various temperatures

Quantitative analysis of hydrogen and hydrogen isotopes at the solid surface; Analyse quantitative de l'hydrogene et de ses isotopes a la surface des solides

Energy Technology Data Exchange (ETDEWEB)

Trocellier, P. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), Service de Recherches de Metallurgie Physique, 91 - Gif-sur-Yvette (France)

2007-07-01

Because of the importance of the effects bound to the hydrogen presence in materials it is particularly important to determine with accuracy the surface and volume distribution of hydrogen. Meanwhile the electronic structure of the hydrogen (one electron) do not allow to use many characterization techniques as the electrons spectroscopies or the X micro analysis. The author presents other possible techniques. (A.L.B.)

Solar hydrogen hybrid system with carbon storage

International Nuclear Information System (INIS)

Zini, G.; Marazzi, R.; Pedrazzi, S.; Tartarini, P.

2009-01-01

A complete solar hydrogen hybrid system has been developed to convert, store and use energy from renewable energy sources. The theoretical model has been implemented in a dynamic model-based software environment and applied to real data to simulate its functioning over a one-year period. Results are used to study system design and performance. A photovoltaic sub-system directly drives a residential load and, if a surplus of energy is available, an electrolyzer to produce hydrogen which is stored in a cluster of nitrogen-cooled tanks filled with AX-21 activated carbons. When the power converted from the sun is not sufficient to cover load needs, hydrogen is desorbed from activated carbon tanks and sent to the fuel-cell sub-system so to obtain electrical energy. A set of sub-systems (bus-bar, buck- and boost-converters, inverter, control circuits), handle the electrical power according to a Programmable Logic Control unit so that the load can be driven with adequate Quality of Service. Hydrogen storage is achieved through physisorption (weak van der Waals interactions) between carbon atoms and hydrogen molecules occurring at low temperature (77 K) in carbon porous solids at relatively low pressures. Storage modeling has been developed using a Langmuir-Freundlich 1st type isotherm and experimental data available in literature. Physisorption storage provides safer operations along with good gravimetric (10.8% at 6 MPa) and volumetric (32.5 g/l at 6 MPa) storage capacities at costs that can be comparable to, or smaller than, ordinary storage techniques (compression or liquefaction). Several test runs have been performed on residential user data-sets: the system is capable of providing grid independence and can be designed to yield a surplus production of hydrogen which can be used to recharge electric car batteries or fill tanks for non-stationary uses. (author)

Hydrogen fuel. Uses

International Nuclear Information System (INIS)

Darkrim-Lamari, F.; Malbrunot, P.

2006-01-01

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

Hydrogen Oxidation Reaction at the Ni/YSZ Anode of Solid Oxide Fuel Cells from First Principles

Science.gov (United States)

Cucinotta, Clotilde S.; Bernasconi, Marco; Parrinello, Michele

2011-11-01

By means of ab initio simulations we here provide a comprehensive scenario for hydrogen oxidation reactions at the Ni/zirconia anode of solid oxide fuel cells. The simulations have also revealed that in the presence of water chemisorbed at the oxide surface, the active region for H oxidation actually extends beyond the metal/zirconia interface unraveling the role of water partial pressure in the decrease of the polarization resistance observed experimentally.

McPhy-Energy’s proposal for solid state hydrogen storage materials and systems

Energy Technology Data Exchange (ETDEWEB)

Jehan, Michel, E-mail: michel.jehan@mcphy.com [McPhy Energy SA, ZA Retière, 26190 La Motte-Fanjas (France); Fruchart, Daniel, E-mail: daniel.fruchart@grenoble.cnrs.fr [McPhy Energy SA, ZA Retière, 26190 La Motte-Fanjas (France); Institut Néel and CRETA, CNRS, 25 Avenue des Martyrs, BP 166, 38042 Grenoble Cedex 9 (France)

2013-12-15

Highlights: •Mechanical alloying with nano-structurizing highly reactive magnesium metal hydrides particles. •Solid reversible hydrogen storage at scale of kg to tons of hydrogen using MgH{sub 2} composite discs. •Natural Expanded Graphite draining heat of reaction during sorption. •Change Phase Material storing reversibly heat of reaction within tank storage as adiabatic system. •Technology fully adapted for renewable energy storage and network energy peak shavings through H{sub 2}. -- Abstract: The renewable resources related, for instance, to solar energies exhibit two main characteristics. They have no practical limits in regards to the efficiency and their various capture methods. However, their intermittence prevents any direct and immediate use of the resulting power. McPhy-Energy proposes solutions based on water electrolysis for hydrogen generation and storage on reversible metal hydrides to efficiently cover various energy generation ranges from MW h to GW h. Large stationary storage units, based on MgH{sub 2}, are presently developed, including both the advanced materials and systems for a total energy storage from ∼70 to more than 90% efficient. Various designs of MgH{sub 2}-based tanks are proposed, allowing the optional storage of the heat of the Mg–MgH{sub 2} reaction in an adjacent phase changing material. The combination of these operations leads to the storage of huge amounts of hydrogen and heat in our so-called adiabatic-tanks. Adapted to intermittent energy production and consumption from renewable sources (wind, sun, tide, etc.), nuclear over-production at night, or others, tanks distribute energy on demand for local applications (on-site domestic needs, refueling stations, etc.) via turbine or fuel cell electricity production.

Use of nuclear method analysis in ultrahigh vacuum. Application to the hydrogen dosage in solids

International Nuclear Information System (INIS)

Chartoire, M.

1982-01-01

It is possible to determine hydrogen by the 1 H( 15 N,αγ) 12 C nuclear reaction, in an ultra-high vacuum and with sample temperature monitoring, without reducing the detection efficiency of the γ rays emitted. This method is sensitive on the surface of the samples as well as in the core. Further, its resolution in depth on the surface is less than 50 x 10 -4 μm for elements with an atomic number above that of silicon. This surface analysis technique competes with and supplements the performance of the Auger and ESCA spectrometries. The cooling or heating of the samples in-situ from -150 0 C to +450 0 C enables an initial approach to be made to the phenomena of adsorption of the hydrogenated species on the surface of the samples. The possibility of plotting concentration profiles to depths of around a micrometer, also provides a means for studying the sorption of hydrogen in solids. The importance is brought to light of the quality of the residual vacuum and mainly of the partial steam pressure in the curves showing the change in the concentration of surface contamination hydrogen according to the quantity of incident ions. At temperatures above 300 0 C, the radiolysis and desorption phenomena of the species thus created become very significant. These were obtained only by making a study in greater depth of the validity conditions of the model used for describing the effusion of hydrogen under the analytical beam [fr

Hydrogenation and high temperature oxidation of Zirconium claddings

International Nuclear Information System (INIS)

Novotny, T.; Perez-Feró, E.; Horváth, M.

2015-01-01

In the last few years a new series of experiments started for supporting the new LOCA criteria, considering the proposals of US NRC. The effects which can cause the embrittlement of VVER fuel claddings were reviewed and evaluated in the framework of the project. The purpose of the work was to determine how the fuel cladding’s hydrogen uptake under normal operating conditions, effect the behavior of the cladding under LOCA conditions. As a first step a gas system equipment with gas valves and pressure gauge was built, in which the zirconium alloy can absorb hydrogen under controlled conditions. In this apparatus E110 (produced by electrolytic method, currently used at Paks NPP) and E110G (produced by a new technology) alloys were hydrogenated to predetermined hydrogen contents. According the results of ring compression tests the E110G alloys lose their ductility above 3200 ppm hydrogen content. This limit can be applied to determine the ductile-brittle transition of the nuclear fuel claddings. After the hydrogenation, high temperature oxidation experiments were carried out on the E110G and E110 samples at 1000 °C and 1200 °C. 16 pieces of E110G and 8 samples of E110 with 300 ppm and 600 ppm hydrogen content were tested. The oxidation of the specimens was performed in steam, under isothermal conditions. Based on the ring compression tests load-displacement curves were recorded. The main objective of the compression tests was to determine the ductile-brittle transition. These results were compared to the results of our previous experiments where the samples did not contain hydrogen. The original claddings showed more ductile behavior than the samples with hydrogen content. The higher hydrogen content resulted in a more brittle mechanical behavior. However no significant difference was observed in the oxidation kinetics of the same cladding types with different hydrogen content. The experiments showed that the normal operating hydrogen uptake of the fuel claddings

Hot Deformation Behavior and a Two-Stage Constitutive Model of 20Mn5 Solid Steel Ingot during Hot Compression

Directory of Open Access Journals (Sweden)

Min Liu

2018-03-01

Full Text Available 20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft forging due to its strength, toughness, and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under a high temperature were not studied. For this article, hot compression experiments under temperatures of 850–1200 °C and strain rates of 0.01 s−1–1 s−1 were conducted using a Gleeble-1500D thermo-mechanical simulator. Flow stress-strain curves and microstructure after hot compression were obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relationship and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 solid steel ingot.

Integrated waste hydrogen utilization project

International Nuclear Information System (INIS)

Armstrong, C.

2004-01-01

'Full text:' The BC Hydrogen Highway's, Integrated Waste Hydrogen Utilization Project (IWHUP) is a multi-faceted, synergistic collaboration that will capture waste hydrogen and promote its use through the demonstration of 'Hydrogen Economy' enabling technologies developed by Canadian companies. IWHUP involves capturing and purifying a small portion of the 600 kg/hr of by-product hydrogen vented to the atmosphere at the ERCO's electrochemical sodium chlorate plant in North Vancouver, BC. The captured hydrogen will then be compressed so it is suitable for transportation on roadways and can be used as a fuel in transportation and stationary fuel cell demonstrations. In summary, IWHUP invests in the following; Facilities to produce up to 20kg/hr of 99.999% pure 6250psig hydrogen using QuestAir's leading edge Pressure Swing Absorption technology; Ultra high-pressure transportable hydrogen storage systems developed by Dynetek Industries, Powertech Labs and Sacre-Davey Engineering; A Mobile Hydrogen Fuelling Station to create Instant Hydrogen Infrastructure for light-duty vehicles; Natural gas and hydrogen (H-CNG) blending and compression facilities by Clean Energy for fueling heavy-duty vehicles; Ten hydrogen, internal combustion engine (H-ICE), powered light duty pick-up vehicles and a specialized vehicle training, maintenance, and emissions monitoring program with BC Hydro, GVRD and the District of North Vancouver; The demonstration of Westport's H-CNG technology for heavy-duty vehicles in conjunction with local transit properties and a specialized vehicle training, maintenance, and emissions monitoring program; The demonstration of stationary fuel cell systems that will provide clean power for reducing peak-load power demands (peak shaving), grid independence and water heating; A comprehensive communications and outreach program designed to educate stakeholders, the public, regulatory bodies and emergency response teams in the local community, Supported by industry

Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Application

Energy Technology Data Exchange (ETDEWEB)

Tao, Greg, G.; Virkar, Anil, V.; Bandopadhyay, Sukumar; Thangamani, Nithyanantham; Anderson, Harlan, U.; Brow, Richard, K.

2009-06-30

Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode, respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and then separated by condensation of the steam to produce pure hydrogen. The rationale was that in such an approach fuel provides a chemical potential replacing the external power conventionally used to drive electrolysis cells (i.e. solid oxide electrolysis cells). A SOFC is similar to the SOFEC by replacing cathode steam with air for power generation. To fulfill the cogeneration objective, a hybrid module comprising reversible SOFEC stacks and SOFC stacks was designed that planar SOFECs and SOFCs were manifolded in such a way that the anodes of both the SOFCs and the SOFECs were fed the same fuel, (i.e. natural gas or coal-derived fuel). Hydrogen was produced by SOFECs and electricity was generated by SOFCs within the same hybrid system. A stand-alone 5 kW system comprising three SOFEC-SOFC hybrid modules and three dedicated SOFC stacks, balance-of-plant components (including a tailgas-fired steam generator and tailgas-fired process heaters), and electronic controls was designed, though an overall

Stress distributions due to hydrogen concentrations in electrochemically charged and aged austenitic stainless steel

International Nuclear Information System (INIS)

Rozenak, P.; Loew, A.

2008-01-01

As a result of hydrogen concentration gradients in type austenitic stainless steels, formed during electrochemical charging and followed by hydrogen loss during aging, at room temperature, surface stresses were developed. These stresses were measured by X-ray technique and the crack formation thus induced could be studied using equilibrium stress equations. After various electrochemical charging and aging times, X-ray diffraction patterns obtained from samples indicated that the reflected and broadened diffraction peaks are the result of the formation of a non-uniform but continuous solid solution in the austenitic matrix. Since both hydrogen penetrations during charging and hydrogen release during aging are diffusion controlled processes and huge hydrogen concentration gradients in the thin surface layer, at depths comparable with the depth of X-ray penetration, are observed. The non-uniform hydrogen concentration in the austenitic matrix, results to the non-uniform expansion of the atomic microstructure and latter inevitably leads to the development of internal stresses. The internal stresses development formulae's are very similar to those relating to non-uniform heating of the materials, where thermal stresses appear due to non-uniform expansion or contraction. The relevant well developed theory is applicable in our case of non-uniform hydrogen concentrations in a solid solution of electrochemically charged and aged austenitic matrix. A few cracks were present on the surface after some minutes of electrochemical charging and the severity of cracking increased as hydrogen was lost during subsequent aging. This is consistent with the expectation of high compressive stresses in the bulk of the specimen during charging and high tensile surface stresses (at the level of 1 x 10 11 Pa) during the aging process. These stresses can induce the formation of surface cracks during the aging process after electrochemical charging in the AISI 316 stainless steel

Enhanced catalytic hydrogenation activity of Ni/reduced graphene oxide nanocomposite prepared by a solid-state method

Science.gov (United States)

Li, Yizhao; Cao, Yali; Jia, Dianzeng

2018-01-01

A simple solid-state method has been applied to synthesize Ni/reduced graphene oxide (Ni/rGO) nanocomposite under ambient condition. Ni nanoparticles with size of 10-30 nm supported on reduced graphene oxide (rGO) nanosheets are obtained through one-pot solid-state co-reduction among nickel chloride, graphene oxide, and sodium borohydride. The Ni/rGO nanohybrid shows enhanced catalytic activity toward the reduction of p-nitrophenol (PNP) into p-aminophenol compared with Ni nanoparticles. The results of kinetic research display that the pseudo-first-order rate constant for hydrogenation reaction of PNP with Ni/rGO nanocomposite is 7.66 × 10-3 s-1, which is higher than that of Ni nanoparticles (4.48 × 10-3 s-1). It also presents superior turnover frequency (TOF, 5.36 h-1) and lower activation energy ( E a, 29.65 kJ mol-1) in the hydrogenation of PNP with Ni/rGO nanocomposite. Furthermore, composite catalyst can be magnetically separated and reused for five cycles. The large surface area and high electron transfer property of rGO support are beneficial for good catalytic performance of Ni/rGO nanocomposite. Our study demonstrates a simple approach to fabricate metal-rGO heterogeneous nanostructures with advanced functions.

Dominance of hole-boring radiation pressure acceleration regime with thin ribbon of ionized solid hydrogen

Science.gov (United States)

Psikal, J.; Matys, M.

2018-04-01

Laser-driven proton acceleration from novel cryogenic hydrogen target of the thickness of tens of microns irradiated by multiPW laser pulse is investigated here for relevant laser parameters accessible in near future. It is demonstrated that the efficiency of proton acceleration from relatively thick hydrogen solid ribbon largely exceeds the acceleration efficiency for a thinner ionized plastic foil, which can be explained by enhanced hole boring (HB) driven by laser ponderomotive force in the case of light ions and lower target density. Three-dimensional particle-in-cell (PIC) simulations of laser pulse interaction with relatively thick hydrogen target show larger energies of protons accelerated in the target interior during the HB phase and reduced energies of protons accelerated from the rear side of the target by quasistatic electric field compared with the results obtained from two-dimensional PIC calculations. Linearly and circularly polarized multiPW laser pulses of duration exceeding 100 fs show similar performance in terms of proton acceleration from both the target interior as well as from the rear side of the target. When ultrashort pulse (∼30 fs) is assumed, the number of accelerated protons from the target interior is substantially reduced.

Operating Point Optimization of a Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Steam Turbine (SOFC-ST Plant

Directory of Open Access Journals (Sweden)

Juanjo Ugartemendia

2013-09-01

Full Text Available This paper presents a hydrogen powered hybrid solid oxide fuel cell-steam turbine (SOFC-ST system and studies its optimal operating conditions. This type of installation can be very appropriate to complement the intermittent generation of renewable energies, such as wind generation. A dynamic model of an alternative hybrid SOFC-ST configuration that is especially suited to work with hydrogen is developed. The proposed system recuperates the waste heat of the high temperature fuel cell, to feed a bottoming cycle (BC based on a steam turbine (ST. In order to optimize the behavior and performance of the system, a two-level control structure is proposed. Two controllers have been implemented for the stack temperature and fuel utilization factor. An upper supervisor generates optimal set-points in order to reach a maximal hydrogen efficiency. The simulation results obtained show that the proposed system allows one to reach high efficiencies at rated power levels.

Thermal effect on gravity waves in a compressible liquid layer over a ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Abstract. This paper deals with the effect of temperature on gravity waves in a compressible liquid layer over a solid half-space. It has been assumed that the liquid layer is under the action of gravity, while the solid half-space is under the influence of initial compressive hydrostatic stress. When the temperature of the.

Thermofluidic compression effects to achieve combustion in a low-compression scramjet engine

Science.gov (United States)

Moura, A. F.; Wheatley, V.; Jahn, I.

2017-12-01

The compression provided by a scramjet inlet is an important parameter in its design. It must be low enough to limit thermal and structural loads and stagnation pressure losses, but high enough to provide the conditions favourable for combustion. Inlets are typically designed to achieve sufficient compression without accounting for the fluidic, and subsequently thermal, compression provided by the fuel injection, which can enable robust combustion in a low-compression engine. This is investigated using Reynolds-averaged Navier-Stokes numerical simulations of a simplified scramjet engine designed to have insufficient compression to auto-ignite fuel in the absence of thermofluidic compression. The engine was designed with a wide rectangular combustor and a single centrally located injector, in order to reduce three-dimensional effects of the walls on the fuel plume. By varying the injected mass flow rate of hydrogen fuel (equivalence ratios of 0.22, 0.17, and 0.13), it is demonstrated that higher equivalence ratios lead to earlier ignition and more rapid combustion, even though mean conditions in the combustor change by no more than 5% for pressure and 3% for temperature with higher equivalence ratio. By supplementing the lower equivalence ratio with helium to achieve a higher mass flow rate, it is confirmed that these benefits are primarily due to the local compression provided by the extra injected mass. Investigation of the conditions around the fuel plume indicated two connected mechanisms. The higher mass flow rate for higher equivalence ratios generated a stronger injector bow shock that compresses the free-stream gas, increasing OH radical production and promoting ignition. This was observed both in the higher equivalence ratio case and in the case with helium. This earlier ignition led to increased temperature and pressure downstream and, consequently, stronger combustion. The heat release from combustion provided thermal compression in the combustor, further

Special structures and properties of hydrogen nanowire confined in a single walled carbon nanotube at extreme high pressure

Directory of Open Access Journals (Sweden)

Yueyuan Xia

2012-06-01

Full Text Available Extensive ab initio molecular dynamics simulations indicate that hydrogen can be confined in single walled carbon nanotubes to form high density and high pressure H2 molecular lattice, which has peculiar shell and axial structures depending on the density or pressure. The band gap of the confined H2 lattice is sensitive to the pressure. Heating the system at 2000K, the H2 lattice is firstly melted to form H2 molecular liquid, and then some of the H2 molecules dissociate accompanied by drastic molecular and atomic reactions, which have essential effect on the electronic structure of the hydrogen system. The liquid hydrogen system at 2000K is found to be a particular mixed liquid, which consists of H2 molecules, H atoms, and H-H-H trimers. The dissociated H atoms and the trimers in the liquid contribute resonance electron states at the Fermi energy to change the material properties substantially. Rapidly cooling the system from 2000K to 0.01 K, the mixed liquid is frozen to form a mixed solid melt with a clear trend of band gap closure. It indicates that this solid melt may become a superconducting nanowire when it is further compressed.

Effects of pH and hydraulic retention time on hydrogen production versus methanogenesis during anaerobic fermentation of organic household solid waste under extreme-thermophilic temperature (70ºC)

DEFF Research Database (Denmark)

Liu, Dawei; Zeng, Raymond Jianxiong; Angelidaki, Irini

2008-01-01

Two continuously stirred tank reactors were operated with household solid waste at 70°C, for hydrogen and methane production. The individual effect of hydraulic retention time (HRT as 1, 2, 3, 4, and 6 days) at pH 7 or pH (5, 5.5, 6, 6.5, 7) at 3-day HRT was investigated on the hydrogen production...... versus methanogenesis. It was found that at pH 7, the maximum hydrogen yield was 107 mL-H2/g VSadded (volatile solid added) but no stable hydrogen production was obtained as after some time methanogenesis was initiated at all tested HRTs. This demonstrated that sludge retention time alone was not enough...... for washing out the methanogens at pH 7 under extreme-thermophilic conditions. Oppositely, we showed that keeping the pH level at 5.5 was enough to inhibit methane and produce hydrogen stably at 3-day HRT. However, the maximum stable hydrogen yield was low at 21 mL-H2/g VSadded. Biotechnol. Bioeng. 2008...

Destructive hydrogenation. [British patent

Energy Technology Data Exchange (ETDEWEB)

1929-07-15

Liquid or readily liquefiable products are obtained from solid distillable carbonaceous materials such as coals, oil shales or other bituminous substances by subjecting the said initial materials to destructive hydrogenation under mild conditions so that the formation of benzine is substantially avoided, and then subjecting the treated material to extraction by solvents. By hydrogenating under mild conditions the heavy oils which prevent the asphaltic substances from being precipitated are preserved, and the separation of the liquid products from the solid residue is facilitated. Solid paraffins and high boiling point constituents suitable for the production of lubricating oils may be removed before or after the extraction process. The extraction is preferably carried out under pressure with solvents which do not precipitate asphaltic substances. Brown coal containing 11 per cent ash is passed at 450/sup 0/C, and 200 atmospheres pressure in counter current to hydrogen; 40 per cent of the coal is converted into liquid products which are condensed out of the hydrogen stream; the pasty residue, on extraction with benzene, yields 45 per cent of high molecular weight products suitable for the production of lubricating oil.

Volumetric, acoustic and viscometric behaviour of dipotassium hydrogen phosphate and disodium hydrogen phosphate in aqueous solution of N-acetyl glycine at different temperatures

International Nuclear Information System (INIS)

Kumar, Harsh; Singla, Meenu; Mittal, Heena

2016-01-01

Highlights: • Densities, speeds of sound, viscosities of phosphate salts in aqueous N-acetyl glycine. • Large values of partial molar volume for dipotassium hydrogen phosphate. • Partial molar volume of transfer are positive for phosphate salts. • Positive B-coefficient values indicate ion–solvent interactions. - Abstract: Densities, speeds of sound and viscosities of dipotassium hydrogen phosphate (DPHP) and disodium hydrogen phosphate (DSHP) in aqueous solutions of N-acetyl glycine (AcGly) are reported at different temperatures. Densities and speeds of sound have been used to calculate apparent molar volume, apparent molar isentropic compression, partial molar volume, partial molar isentropic compression, partial molar volume of transfer, partial molar isentropic compression of transfer and partial molar expansivity. Pair and triplet interaction coefficients have also been calculated. Experimental viscosities have been used to determine B-coefficients. Further pair and triplet interaction coefficients have also been calculated. The results are discussed in terms of solute–solvent interactions.

Properties of solid polymer electrolyte fluorocarbon film. [used in hydrogen/oxygen fuel cells

Science.gov (United States)

Alston, W. B.

1973-01-01

The ionic fluorocarbon film used as the solid polymer electrolyte in hydrogen/oxygen fuel cells was found to exhibit delamination failures. Polarized light microscopy of as-received film showed a lined region at the center of the film thickness. It is shown that these lines were not caused by incomplete saponification but probably resulted from the film extrusion process. The film lines could be removed by an annealing process. Chemical, physical, and tensile tests showed that annealing improved or sustained the water contents, spectral properties, thermo-oxidative stability, and tensile properties of the film. The resistivity of the film was significantly decreased by the annealing process.

Hydrogen as a New Alloying Element in Metals

International Nuclear Information System (INIS)

Shapovalov, Vladimir

1999-01-01

Hydrogen was regarded as a harmful impurity in many alloys and particularly in steels where it gives rise to a specific type of embrittlement and forms various discontinuities like flakes and blowholes. For this reason, the researcher efforts were mainly focused on eliminating hydrogen's negative impacts and explaining its uncommonly high diffusivity in condensed phases. Meanwhile, positive characteristics of hydrogen as an alloying element remained unknown for quite a long time. Initial reports in this field did not appear before the early 1970s. Data on new phase diagrams are given for metal-hydrogen systems where the metal may or may not form hydrides. Various kinds of hydrogen impact on structure formation in solidification, melting and solid-solid transformations are covered. Special attention is given to the most popular alloys based on iron, aluminum, copper, nickel, magnesium and titanium. Detailed is what is called gas-eutectic reaction resulting in a special type of gas-solid structure named gasarite. Properties and applications of gasars - gasaritic porous materials - are dealt with. Various versions of solid-state alloying with hydrogen are discussed that change physical properties and fabrication characteristics of metals. Details are given on a unique phenomenon of anomalous spontaneous deformation due to combination of hydrogen environment and polymorphic transformation. All currently known versions of alloying with hydrogen are categorized for both hydride-forming and non-hydrid forming metals

Hydrogen at extreme pressures (Review Article)

International Nuclear Information System (INIS)

Goncharov, Alexander F.; Howie, Ross T.; Gregoryanz Eugene

2013-01-01

Here we review recent experimental and theoretical studies of hydrogen approaching metallization regime. Experimental techniques have made great advances over the last several years making it possible to reach previously unachievable conditions of pressure and temperature and to probe hydrogen at these conditions. Theoretical methods have also greatly improved; exemplified through the prediction of new structural and ordered quantum states. Recently, a new solid phase of hydrogen, phase IV, has been discovered in a high-pressure high-temperature domain. This phase is quite unusual structurally and chemically as it represents an intermediate state between common molecular and monatomic configurations. Moreover, it shows remarkable fluxional characteristics related to its quantum nature, which makes it unique among the solid phases, even of light elements. However, phase IV shows the presence of a band gap and exhibits distinct phonon and libron characteristic of classical solids. The quantum behavior of hydrogen in the limit of very high pressure remains an open question. Prospects of studying hydrogen at more extreme conditions by static and combined static-dynamic methods are also presented.

Probing the Conformation of an IgG1 Monoclonal Antibody in Lyophilized Solids Using Solid-State Hydrogen-Deuterium Exchange with Mass Spectrometric Analysis (ssHDX-MS).

Science.gov (United States)

Moussa, Ehab M; Singh, Satish K; Kimmel, Michael; Nema, Sandeep; Topp, Elizabeth M

2018-02-05

Therapeutic proteins are often formulated as lyophilized products to improve their stability and prolong shelf life. The stability of proteins in the solid-state has been correlated with preservation of native higher order structure and/or molecular mobility in the solid matrix, with varying success. In the studies reported here, we used solid-state hydrogen-deuterium exchange with mass spectrometric analysis (ssHDX-MS) to study the conformation of an IgG1 monoclonal antibody (mAb) in lyophilized solids and related the extent of ssHDX to aggregation during storage in the solid phase. The results demonstrate that the extent of ssHDX correlated better with aggregation rate during storage than did solid-state Fourier-transform infrared (ssFTIR) spectroscopic measurements. Interestingly, adding histidine to sucrose at different formulation pH conditions decreased aggregation of the mAb, an effect that did not correlate with structural or conformational changes as measured by ssFTIR or ssHDX-MS. Moreover, peptide-level ssHDX-MS analysis in four selected formulations demonstrated global changes across the structure of the mAb when lyophilized with sucrose, trehalose, or mannitol, whereas site-specific changes were observed when lyophilized with histidine as the sole excipient.

Thermal effect on gravity waves in a compressible liquid layer over a ...

Indian Academy of Sciences (India)

This paper deals with the effect of temperature on gravity waves in a compressible liquid layer over a solid half-space. It has been assumed that the liquid layer is under the action of gravity, while the solid half-space is under the influence of initial compressive hydrostatic stress. When the temperature of the half-space is ...

Combined Solid State and High Pressure Hydrogen Storage

DEFF Research Database (Denmark)

Grube, Elisabeth; Jensen, Torben René

Presented at The First European Early Stage Researcher's Conference on Hydrogen Storage in Belgrade, Serbia.......Presented at The First European Early Stage Researcher's Conference on Hydrogen Storage in Belgrade, Serbia....

Structure and Properties of Silica Glass Densified in Cold Compression and Hot Compression

Science.gov (United States)

Guerette, Michael; Ackerson, Michael R.; Thomas, Jay; Yuan, Fenglin; Bruce Watson, E.; Walker, David; Huang, Liping

2015-10-01

Silica glass has been shown in numerous studies to possess significant capacity for permanent densification under pressure at different temperatures to form high density amorphous (HDA) silica. However, it is unknown to what extent the processes leading to irreversible densification of silica glass in cold-compression at room temperature and in hot-compression (e.g., near glass transition temperature) are common in nature. In this work, a hot-compression technique was used to quench silica glass from high temperature (1100 °C) and high pressure (up to 8 GPa) conditions, which leads to density increase of ~25% and Young’s modulus increase of ~71% relative to that of pristine silica glass at ambient conditions. Our experiments and molecular dynamics (MD) simulations provide solid evidences that the intermediate-range order of the hot-compressed HDA silica is distinct from that of the counterpart cold-compressed at room temperature. This explains the much higher thermal and mechanical stability of the former than the latter upon heating and compression as revealed in our in-situ Brillouin light scattering (BLS) experiments. Our studies demonstrate the limitation of the resulting density as a structural indicator of polyamorphism, and point out the importance of temperature during compression in order to fundamentally understand HDA silica.

Design of a hydrogen fueling station for Vancouver, BC

International Nuclear Information System (INIS)

Dikeos, J.; Haas, J.; Maddaloni, J.; Owen, T.; Smolak, T.; Songprakorp, R.; Sodouri, P.; St Germain, L.; Tura, A.; Rowe, A.

2004-01-01

A public hydrogen refueling station has been designed to service a minimum daily capacity of 50 light-duty hydrogen fuel cell vehicles, each requiring 3 kg of compressed gaseous hydrogen at 5000 psi. A peak hourly fueling rate of 20 kg, or slightly less than 7 cars, can be accommodated. The station is designed around bulk liquid hydrogen storage, and energy efficient liquid compression. On-site storage with centralized production allows for great flexibility in the design and the simple fueling process results in fewer potential failure modes. High customer demand can easily be accommodated due to a four minute filling time, made possible by a low temperature hydrogen filling system. The overall well to wheel pathway of this fueling process generates up to 95% less CO 2 and requires up to 42% less energy than gasoline. The proposed design requires a low capital investment, and uses components easily available from a proven supplier base. An economic analysis shows that the delivered hydrogen cost is between $0.11/mile and $0.18/mile, based on a ten year discounted cash flow analysis. (author)

Sustainable hydrogen production

Energy Technology Data Exchange (ETDEWEB)

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

1996-01-01

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

Effective hydrogen diffusion coefficient for solidifying aluminium alloys

International Nuclear Information System (INIS)

Felberbaum, M.; Landry-Desy, E.; Weber, L.; Rappaz, M.

2011-01-01

An effective hydrogen diffusion coefficient has been calculated for two solidifying Al - 4.5 wt.% Cu and Al - 10 wt.% Cu alloys as a function of the volume fraction of solid. For this purpose, in situ X-ray tomography was performed on these alloys. For each volume fraction of solid between 0.6 and 0.9, a representative volume element of the microstructure was extracted. Solid and liquid voxels were assimilated to solid and liquid nodes in order to solve the hydrogen diffusion equation based on the chemical potential and using a finite volume formulation. An effective hydrogen diffusion coefficient based on the volume fraction of solid only could be deduced from the results of the numerical model at steady state. The results are compared with various effective medium theories.

Hydrogen Production from Water by Photolysis, Sonolysis and Sonophotolysis with Solid Solutions of Rare Earth, Gallium and Indium Oxides as Heterogeneous Catalysts

Directory of Open Access Journals (Sweden)

Marta Penconi

2015-07-01

Full Text Available In this work, we present the hydrogen production by photolysis, sonolysis and sonophotolysis of water in the presence of newly synthesized solid solutions of rare earth, gallium and indium oxides playing as catalysts. From the experiments of photolysis, we found that the best photocatalyst is the solid solution Y0.8Ga0.2InO3 doped by sulphur atoms. In experiments of sonolysis, we optimized the rate of hydrogen production by changing the amount of water, adding ethanol and tuning the power of our piezoelectric transducer. Finally, we performed sonolysis and sonophotolysis experiments in the presence of S:Y0.8Ga0.2InO3 finding a promising synergistic effect of UV-visible electromagnetic waves and 38 kHz ultrasound waves in producing H2.

[Solid state isotope hydrogen exchange for deuterium and tritium in human gene-engineered insulin].

Science.gov (United States)

Zolotarev, Yu A; Dadayan, A K; Kozik, V S; Gasanov, E V; Nazimov, I V; Ziganshin, R Kh; Vaskovsky, B V; Murashov, A N; Ksenofontov, A L; Haribin, O N; Nikolaev, E N; Myasoedov, N F

2014-01-01

The reaction of high temperature solid state catalytic isotope exchange in peptides and proteins under the action of catalyst-activated spillover hydrogen was studied. The reaction of human gene-engineered insulin with deuterium and tritium was conducted at 120-140° C to produce insulin samples containing 2-6 hydrogen isotope atoms. To determine the distribution of the isotope label over tritium-labeled insulin's amino acid residues, oxidation of the S-S bonds of insulin by performic acid was performed and polypeptide chains isolated; then their acid hydrolysis, amino acid analysis and liquid scintillation counts of tritium in the amino acids were conducted. The isotope label was shown to be incorporated in all amino acids of the protein, with the peptide fragment FVNQHLCGSHLVE of the insulin β-chain showing the largest incorporation. About 45% of the total protein isotope label was incorporated in His5 and His10 of this fragment. For the analysis of isotope label distribution in labeled insulin's peptide fragments, the recovery of the S-S bonds by mercaptoethanol, the enzymatic hydrolysis by glutamyl endopeptidase from Bacillus intermedius and HPLC division of the resulting peptides were carried out. Attribution of the peptide fragments formed due to hydrolysis at the Glu-X bond in the β-chain was accomplished by mass spectrometry. Mass spectrometry analysis data of the deuterium-labeled insulin samples' isotopomeric composition showed that the studied solid state isotope exchange reaction equally involved all the protein molecules. Biological studying of tritium-labeled insulin showed its physiological activity to be completely retained.

Compression ratio of municipal solid waste simulation using artificial neural network and adaptive neurofuzzy system

Directory of Open Access Journals (Sweden)

Maryam Mokhtari

2014-07-01

Full Text Available The compression ratio of Municipal Solid Waste (MSW is an essential parameter for evaluation of waste settlement. Since it is relatively time-consuming to determine compression ratio from oedometer tests and there exist difficulties associated with working on waste materials, it will be useful to develop models based on waste physical properties. Therefore, present research attempts to develop proper prediction models using ANFIS and ANN models. The compression ratio was modeled as a function of the physical properties of waste including dry unit weight, water content, and biodegradable organic content. A reliable experimental database of oedometer tests, taken from the literature, was employed to train and test the ANN and ANFIS models. The performance of the developed models was investigated according to different statistical criteria (i.e. correlation coefficient, root mean squared error, and mean absolute error recommended by researchers. The final models have demonstrated the correlation coefficients higher than 90% and low error values; so, they have capability for acceptable prediction of municipal solid waste compression ratio. Furthermore, the values of performance measures obtained for ANN and ANFIS models indicate that the ANFIS model performs better than ANN model.   Resumen El índice de compresión de residuos sólidos es un parámetro esencial para la evaluación del asentamiento de un basurero municipal. Debido al desgaste de tiempo para determinar el índice de compresión a partir de pruebas edométricas y debido a las dificultades asociadas al trabajo con materiales desechados es necesario desarrollar modelos basados en las propiedades físicas de los desechos solidos. Además, la presente investigación pretende  desarrollar modelos de predicción apropiados a partir de los esquemas ANFIS y ANN. El índice de comprensión se modeló como una función de propiedades físicas de desechos que incluyen el peso seco de una

Treatment and storage of hydrogen isotopes

International Nuclear Information System (INIS)

Jung, H. S.; Lee, H. S.; An, D. H.; Kim, K. R.; Lee, S. H.; Choi, H. J.; Back, S. W.; Kang, H. S.; Eom, K. Y.; Lee, M. S.

2000-01-01

Storage of gaseous hydrogen isotopes in a cylinder is a well-established technology. However, Immobilization in the solid form is preferred for long-term storage of radioactive isotope gas because of the concern for leakage of the gas. The experimental thermodynamic p-c-T data show that Ti and U soak up hydrogen isotope gas at a temperature of a few hundred .deg. C and modest pressures. It was found that more hydrogen is dissolved in the metal than deuterium at constant pressure. Thus, the lighter isotope tends to be enriched in the solid phase

The thermodynamics and kinetics of interstitial solid solutions

International Nuclear Information System (INIS)

Silva, J.R.G. da.

1976-04-01

Studies of hydrogen metal systems where the hidrogen is disolved in a solid solution are presented. Particular items of interest are: the thermodynamics of the hydrogen-iron system; the solubility of hidrogen in super pure iron single crytals; the thermodinamic functions of hydrogen in solid solutions of Nb, Ta and V; and the solubility of hydrogen in α-manganese. The diffusion of carbon and nitrogen in BCC iron is also studied

A study of solid wall models for weakly compressible SPH

Energy Technology Data Exchange (ETDEWEB)

Valizadeh, Alireza, E-mail: alireza.valizadeh@monash.edu [Department of Mechanical and Aerospace Engineering, Monash University, Clayton VIC 3800 (Australia); Monaghan, Joseph J., E-mail: joe.monaghan@monash.edu [School of Mathematical Sciences, Monash University, Clayton VIC 3800 (Australia)

2015-11-01

This paper is concerned with a comparison of two methods of treating solid wall boundaries in the weakly compressible (SPH) method. They have been chosen because of their wide use in simulations. These methods are the boundary force particles of Monaghan and Kajtar [24] and the use of layers of fixed boundary particles. The latter was first introduced by Morris et al. [26] but has since been improved by Adami et al. [1] whose algorithm involves interpolating the pressure and velocity from the actual fluid to the boundary particles. For each method, we study the effect of the density diffusive terms proposed by Molteni and Colagrossi [19] and modified by Antuono et al. [3]. We test the methods by a series of simulations commencing with the time-dependent spin-down of fluid within a cylinder and the behaviour of fluid in a box subjected to constant acceleration at an angle to the walls of the box, and concluding with a dam break over a triangular obstacle. In the first two cases the results from the two methods can be compared to analytical solutions while, in the latter case, they can be compared with experiments and other methods. These results show that the method of Adami et al. together with density diffusion is in very satisfactory agreement with the experimental results and is, overall, the best of the methods discussed here.

Loss of shear strength in polycrystalline tungsten under shock compression

International Nuclear Information System (INIS)

Dandekar, D.P.

1976-01-01

A reexamination of existing data on shock compression of polycrystalline tungsten at room temperature indicates that tungsten may be an exception to the common belief that metals do not behave like elastic-isotropic solids under shock compression

Canadian hydrogen safety program

International Nuclear Information System (INIS)

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

2007-01-01

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

Microstructure and kinetics evolution in MgH2–TiO2 pellets after hydrogen cycling

International Nuclear Information System (INIS)

Mirabile Gattia, D.; Di Girolamo, G.; Montone, A.

2014-01-01

Highlights: • MgH 2 was ball milled with TiO 2 anatase phase and expanded graphite to prepare pellets. • Different pellets have been prepared at different compression load. • Pellets were repeatedly cycled under hydrogen pressure to simulate tank exercise and verify their stability. • The compression load highly affects the stability of the pellets to cycling. • Microstructural evolution of the particles due to cycling have been observed. - Abstract: The interest in Mg-based hydrides for solid state hydrogen storage is associated to their capability to reversibly absorb and desorb large amounts of hydrogen. In this work MgH 2 powder with 5 wt.% TiO 2 was ball milled for 10 h. The as-milled nanostructured powder was enriched with 5 wt.% of Expanded Natural Graphite (ENG) and then compacted in cylindrical pellets by cold pressing using different loads. Both the powder and the pellets were subjected to kinetic and thermodynamic tests using a Sievert’s type gas reaction controller, in order to study the microstructural and kinetic changes which took place during repeated H 2 absorption and desorption cycles. The pellets exhibited good kinetic performance and durability, even if the pressure of compaction revealed to be an important parameter for their mechanical stability. Scanning Electron Microscopy observations of as-prepared and cycled pellets were carried out to investigate the evolution of their microstructure. In turn the phase composition before and after cycling was analyzed by X-ray diffraction

Mathematical analysis of compressive/tensile molecular and nuclear structures

Science.gov (United States)

Wang, Dayu

Mathematical analysis in chemistry is a fascinating and critical tool to explain experimental observations. In this dissertation, mathematical methods to present chemical bonding and other structures for many-particle systems are discussed at different levels (molecular, atomic, and nuclear). First, the tetrahedral geometry of single, double, or triple carbon-carbon bonds gives an unsatisfying demonstration of bond lengths, compared to experimental trends. To correct this, Platonic solids and Archimedean solids were evaluated as atoms in covalent carbon or nitrogen bond systems in order to find the best solids for geometric fitting. Pentagonal solids, e.g. the dodecahedron and icosidodecahedron, give the best fit with experimental bond lengths; an ideal pyramidal solid which models covalent bonds was also generated. Second, the macroscopic compression/tension architectural approach was applied to forces at the molecular level, considering atomic interactions as compressive (repulsive) and tensile (attractive) forces. Two particle interactions were considered, followed by a model of the dihydrogen molecule (H2; two protons and two electrons). Dihydrogen was evaluated as two different types of compression/tension structures: a coaxial spring model and a ring model. Using similar methods, covalent diatomic molecules (made up of C, N, O, or F) were evaluated. Finally, the compression/tension model was extended to the nuclear level, based on the observation that nuclei with certain numbers of protons/neutrons (magic numbers) have extra stability compared to other nucleon ratios. A hollow spherical model was developed that combines elements of the classic nuclear shell model and liquid drop model. Nuclear structure and the trend of the "island of stability" for the current and extended periodic table were studied.

Scaling of compression strength in disordered solids: metallic foams

Directory of Open Access Journals (Sweden)

J. Kováčik

2016-03-01

Full Text Available The scaling of compression strength with porosity for aluminium foams was investigated. The Al 99.96, AlMg1Si0.6 and AlSi11Mg0.6 foams of various porosity, sample size with and without surface skin were tested in compression. It was observed that the compression strength of aluminium foams scales near the percolation threshold with Tf ≈ 1.9 - 2.0 almost independently on the matrix alloy, sample size and presence of surface skin. The difference of the obtained values of Tf to the theoretical estimate of Tf = 2.64 ± 0.3 by Arbabi and Sahimi and to Ashby estimate of 1.5 was explained using an analogy with the Daoud and Coniglio approach to the scaling of the free energy of sol-gel transition. It leads to the finding that, there are two different universality classes for the critical exponent Tf: when the stretching forces dominate Tf = f = 2.1, respectively when bending forces prevail Tf = .d = 2.64 seems to be valid. Another possibility is the validity of relation Tf ≤ f which varies only according to the universality class of modulus of elasticity in foam.

Hydrogen-based industry from remote excess hydroelectricity

International Nuclear Information System (INIS)

Ouellette, N.; Rogner, H.-H.; Scott, D.S.

1997-01-01

This paper examines synergies, opportunities and barriers associated with hydrogen and excess hydro-electricity in remote areas. The work is based on a case study that examined the techno-economic feasibility of a new hydrogen-based industry using surplus/off-peak generating capacity of the Taltson Dam and Generating Station in the Northwest Territories, Canada. After evaluating the amount and cost of hydrogen that could be produced from the excess capacity, the study investigates three hydrogen utilization scenarios: (1) merchant liquid or compressed hydrogen, (2) hydrogen as a chemical feedstock for the production of hydrogen peroxide, (3) methanol production from biomass, oxygen and hydrogen. Hydrogen peroxide production is the most promising and attractive strategy in the Fort Smith context. The study also illustrates patterns that recur in isolated sites throughout the world. (Author)

Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage.

Science.gov (United States)

Dürr, Stefan; Müller, Michael; Jorschick, Holger; Helmin, Marta; Bösmann, Andreas; Palkovits, Regina; Wasserscheid, Peter

2017-01-10

An integration of CO 2 -free hydrogen generation through methane decomposition coupled with hydrogen/methane separation and chemical hydrogen storage through liquid organic hydrogen carrier (LOHC) systems is demonstrated. A potential, very interesting application is the upgrading of stranded gas, for example, gas from a remote gas field or associated gas from off-shore oil drilling. Stranded gas can be effectively converted in a catalytic process by methane decomposition into solid carbon and a hydrogen/methane mixture that can be directly fed to a hydrogenation unit to load a LOHC with hydrogen. This allows for a straight-forward separation of hydrogen from CH 4 and conversion of hydrogen to a hydrogen-rich LOHC material. Both, the hydrogen-rich LOHC material and the generated carbon on metal can easily be transported to destinations of further industrial use by established transport systems, like ships or trucks. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-protecting nonlinear compression in a solid fiber for long-term stable ultrafast lasers at 2 μm wavelength

Science.gov (United States)

Stutzki, Fabian; Gaida, Christian; Gebhardt, Martin; Jauregui, Cesar; Limpert, Jens; Tünnermann, Andreas; Pupeza, Ioachim

2017-02-01

Ultrashort-pulse laser systems are an enabling technology for numerous applications. The stability of such systems is especially crucial for frequency metrology and high precision spectroscopy. Thulium-based fiber lasers are an ideal starting point as a reliable and yet powerful source for the nonlinear conversion towards the mid-IR region. Recently, we have demonstrated that nonlinear self-compression in a fused silica solid-core fiber allows for few-cycle pulse duration with up to 24 MW peak power using a high-repetition rate thulium-based fiber laser system operating at around 2 μm wavelength [1]. This experiment operates near the self-focusing limit of about 24 MW for circular polarization, which increases the requirements for the system stability due to the risk of a fiber damage. Here, we present a self-protecting nonlinear compression regime allowing for long-term operation and high output-pulse stability with very similar output performance.

Probing hydrogen bonds in the antibody-bound HIV-1 gp120 V3 loop by solid state NMR REDOR measurements

Energy Technology Data Exchange (ETDEWEB)

Balbach, John J. [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Yang Jun; Weliky, David P. [Michigan State University, Department of Chemistry (United States); Steinbach, Peter J. [National Institutes of Health, Center for Molecular Modeling, Center for Information Technology (United States); Tugarinov, Vitali; Anglister, Jacob [Weizmann Institute of Science, Department of Structural Biology (Israel); Tycko, Robert [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

2000-04-15

We describe solid state NMR measurements on frozen solutions of the complex of the 24-residue HIV-1 gp120 V3 loop peptide RP135 with the Fab fragment of the anti-gp120 antibody 0.5{beta}, using rotational echo double resonance (REDOR). In order to probe possible hydrogen bonding between arginine side chains and glycine backbone carbonyls in the region of the conserved Gly-Pro-Gly-Arg (GPGR) motif of the V3 loop, RP135 samples were prepared with {sup 15}N labels at the {eta} nitrogen positions of arginine side chains and {sup 13}C labels at glycine carbonyl positions and {sup 13}C-detected {sup 13}C-{sup 15}N REDOR measurements were performed on peptide/antibody complexes of these labeled samples. Such hydrogen bonding was previously observed in a crystal structure of the V3 loop peptide/antibody complex RP142/59.1 [Ghiara et al. (1994) Science, 264, 82-85], but is shown by the REDOR measurements to be absent in the RP135/0.5{beta} complex. These results confirm the antibody-dependent conformational differences in the GPGR motif suggested by previously reported solid state NMR measurements of {phi} and {psi} backbone dihedral angles in the RP135/0.5{beta} complex. In addition, we describe REDOR measurements on the helical synthetic peptide MB(i+4)EK in frozen solution that establish our ability to detect {sup 13}C-{sup 15}N dipole-dipole couplings in the distance range appropriate to these hydrogen bonding studies. We also report the results of molecular modeling calculations on the central portion RP135, using a combination of the solid state NMR restraints of Weliky et al. [Nat. Struct. Biol., 6, 141-145, 1999] and the liquid state NMR restraints of Tugarinov et al. (Nat. Struct. Biol., 6, 331-335, 1999]. The dynamics calculations demonstrate the mutual compatibility of the two sets of experimental structural restraints and reduce ambiguities in the solid state NMR restraints that result from symmetry and signal-to-noise considerations.

Probing hydrogen bonds in the antibody-bound HIV-1 gp120 V3 loop by solid state NMR REDOR measurements

International Nuclear Information System (INIS)

Balbach, John J.; Yang Jun; Weliky, David P.; Steinbach, Peter J.; Tugarinov, Vitali; Anglister, Jacob; Tycko, Robert

2000-01-01

We describe solid state NMR measurements on frozen solutions of the complex of the 24-residue HIV-1 gp120 V3 loop peptide RP135 with the Fab fragment of the anti-gp120 antibody 0.5β, using rotational echo double resonance (REDOR). In order to probe possible hydrogen bonding between arginine side chains and glycine backbone carbonyls in the region of the conserved Gly-Pro-Gly-Arg (GPGR) motif of the V3 loop, RP135 samples were prepared with 15 N labels at the η nitrogen positions of arginine side chains and 13 C labels at glycine carbonyl positions and 13 C-detected 13 C- 15 N REDOR measurements were performed on peptide/antibody complexes of these labeled samples. Such hydrogen bonding was previously observed in a crystal structure of the V3 loop peptide/antibody complex RP142/59.1 [Ghiara et al. (1994) Science, 264, 82-85], but is shown by the REDOR measurements to be absent in the RP135/0.5β complex. These results confirm the antibody-dependent conformational differences in the GPGR motif suggested by previously reported solid state NMR measurements of φ and Ψ backbone dihedral angles in the RP135/0.5β complex. In addition, we describe REDOR measurements on the helical synthetic peptide MB(i+4)EK in frozen solution that establish our ability to detect 13 C- 15 N dipole-dipole couplings in the distance range appropriate to these hydrogen bonding studies. We also report the results of molecular modeling calculations on the central portion RP135, using a combination of the solid state NMR restraints of Weliky et al. [Nat. Struct. Biol., 6, 141-145, 1999] and the liquid state NMR restraints of Tugarinov et al. (Nat. Struct. Biol., 6, 331-335, 1999]. The dynamics calculations demonstrate the mutual compatibility of the two sets of experimental structural restraints and reduce ambiguities in the solid state NMR restraints that result from symmetry and signal-to-noise considerations

Measurement of backbone hydrogen-deuterium exchange in the type III secretion system needle protein PrgI by solid-state NMR

Science.gov (United States)

Chevelkov, Veniamin; Giller, Karin; Becker, Stefan; Lange, Adam

2017-10-01

In this report we present site-specific measurements of amide hydrogen-deuterium exchange rates in a protein in the solid state phase by MAS NMR. Employing perdeuteration, proton detection and a high external magnetic field we could adopt the highly efficient Relax-EXSY protocol previously developed for liquid state NMR. According to this method, we measured the contribution of hydrogen exchange on apparent 15N longitudinal relaxation rates in samples with differing D2O buffer content. Differences in the apparent T1 times allowed us to derive exchange rates for multiple residues in the type III secretion system needle protein.

Hydrogen Village : creating hydrogen and fuel cell communities

International Nuclear Information System (INIS)

Smith, G.R.

2009-01-01

The Hydrogen Village (H2V) is a collaborative public-private partnership administered through Hydrogen and Fuel Cells Canada and funded by the Governments of Canada and Ontario. This end user-driven, market development program accelerates the commercialization of hydrogen and fuel cell (FC) technologies throughout the Greater Toronto Area (GTA). The program targets 3 specific aspects of market development, notably deployment of near market technologies in community based stationary and mobile applications; development of a coordinated hydrogen delivery and equipment service infrastructure; and societal factors involving corporate policy and public education. This presentation focused on lessons learned through outreach programs and the deployment of solid oxide fuel cell (SOFC) heat and power generation; indoor and outdoor fuel cell back up power systems; fuel cell-powered forklifts, delivery vehicles, and utility vehicles; hydrogen internal combustion engine powered shuttle buses, sedans, parade float; hydrogen production/refueling stations in the downtown core; and temporary fuel cell power systems

Compression-cuticle relationship of seed ferns: Insights from liquid-solid states FTIR (Late Palaeozoic-Early Mesozoic, Canada-Spain-Argentina)

Science.gov (United States)

Zodrow, E.L.; D'Angelo, J. A.; Mastalerz, Maria; Keefe, D.

2009-01-01

Cuticles have been macerated from suitably preserved compressed fossil foliage by Schulze's process for the past 150 years, whereas the physical-biochemical relationship between the "coalified layer" with preserved cuticle as a unit has hardly been investigated, although they provide complementary information. This relationship is conceptualized by an analogue model of the anatomy of an extant leaf: "vitrinite (mesophyll) + cuticle (biomacropolymer) = compression". Alkaline solutions from Schulze's process as a proxy for the vitrinite, are studied by means of liquid-solid states Fourier transform infrared spectroscopy (FTIR). In addition, cuticle-free coalified layers and fossilized cuticles of seed ferns mainly from Canada, Spain and Argentina of Late Pennsylvanian-Late Triassic age are included in the study sample. Infrared data of cuticle and alkaline solutions differ which is primarily contingent on the mesophyll +biomacropolymer characteristics. The compression records two pathways of organic matter transformation. One is the vitrinized component that reflects the diagenetic-post-diagenetic coalification history parallel with the evolution of the associated coal seam. The other is the cuticle that reflects the sum-total of evolutionary pathway of the biomacropolymer, its monomeric, or polymeric fragmentation, though factors promoting preservation include entombing clay minerals and lower pH conditions. Caution is advised when interpreting liquid-state-based FTIR data, as some IR signals may have resulted from the interaction of Schulze's process with the cuticular biochemistry. A biochemical-study course for taphonomy is suggested, as fossilized cuticles, cuticle-free coalified layers, and compressions are responses to shared physicogeochemical factors. ?? 2009 Elsevier B.V. All rights reserved.

Compression-cuticle relationship of seed ferns: Insights from liquid-solid states FTIR (Late Palaeozoic-Early Mesozoic, Canada-Spain-Argentina)

Energy Technology Data Exchange (ETDEWEB)

Zodrow, Erwin L. [Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia (Canada); D' Angelo, Jose A. [Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales (IANIGLA), CCT-CONICET-Mendoza, Avda. Ruiz Leal s/n Parque Gral. San Martin (5500) Mendoza (Argentina); Area de Quimica, Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Centro Universitario - M5502JMA - Mendoza (Argentina); Mastalerz, Maria [Indiana Geological Survey, Indiana University, 611 North Walnut Grove, Bloomington, IN 47405-2208 (United States); Keefe, Dale [Molecular Spectroscopy Research Laboratory, Department of Chemistry, Cape Breton University, Sydney, Nova Scotia (Canada)

2009-08-01

Cuticles have been macerated from suitably preserved compressed fossil foliage by Schulze's process for the past 150 years, whereas the physical-biochemical relationship between the ''coalified layer'' with preserved cuticle as a unit has hardly been investigated, although they provide complementary information. This relationship is conceptualized by an analogue model of the anatomy of an extant leaf: ''vitrinite (mesophyll) + cuticle (biomacropolymer) = compression''. Alkaline solutions from Schulze's process as a proxy for the vitrinite, are studied by means of liquid-solid states Fourier transform infrared spectroscopy (FTIR). In addition, cuticle-free coalified layers and fossilized cuticles of seed ferns mainly from Canada, Spain and Argentina of Late Pennsylvanian-Late Triassic age are included in the study sample. Infrared data of cuticle and alkaline solutions differ which is primarily contingent on the mesophyll +biomacropolymer characteristics. The compression records two pathways of organic matter transformation. One is the vitrinized component that reflects the diagenetic-post-diagenetic coalification history parallel with the evolution of the associated coal seam. The other is the cuticle that reflects the sum-total of evolutionary pathway of the biomacropolymer, its monomeric, or polymeric fragmentation, though factors promoting preservation include entombing clay minerals and lower pH conditions. Caution is advised when interpreting liquid-state-based FTIR data, as some IR signals may have resulted from the interaction of Schulze's process with the cuticular biochemistry. A biochemical-study course for taphonomy is suggested, as fossilized cuticles, cuticle-free coalified layers, and compressions are responses to shared physicogeochemical factors. (author)

Tailoring the properties of ammine metal borohydrides for solid-state hydrogen storage.

Science.gov (United States)

Jepsen, Lars H; Ley, Morten B; Filinchuk, Yaroslav; Besenbacher, Flemming; Jensen, Torben R

2015-04-24

A series of halide-free ammine manganese borohydrides, Mn(BH4 )2 ⋅nNH3 , n=1, 2, 3, and 6, a new bimetallic compound Li2 Mn(BH4 )4 ⋅6NH3 , and the first ammine metal borohydride solid solution Mg1-x Mnx (BH4 )2 ⋅6NH3 are presented. Four new crystal structures have been determined by synchrotron radiation powder X-ray diffraction and the thermal decomposition is systematically investigated for all the new compounds. The solid-gas reaction between Mn(BH4 )2 and NH3 provides Mn(BH4 )2 ⋅6NH3 . The number of NH3 per Mn has been varied by mechanochemical treatment of Mn(BH4 )2 ⋅6NH3 -Mn(BH4 )2 mixtures giving rise to increased hydrogen purity for n/m≤1 for M(BH4 )m ⋅nNH3 . The structures of Mg(BH4 )2 ⋅3NH3 and Li2 Mg(BH4 )4 ⋅6NH3 have been revisited and new structural models are presented. Finally, we demonstrate that ammonia destabilizes metal borohydrides with low electronegativity of the metal (χp ∼1.6) are generally stabilized. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biosurfactant-enhanced hydrogen production from organic fraction of municipal solid waste using co-culture of E. coli and Enterobacter aerogenes.

Science.gov (United States)

Sharma, Preeti; Melkania, Uma

2017-11-01

The effect of biosurfactants (surfactin and saponin) on the hydrogen production from organic fraction of municipal solid waste (OFMSW) was investigated using co-culture of facultative anaerobes Enterobacter aerogenes and E. coli. The biosurfactants were applied in the concentration ranges of 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 5.0% each. Cumulative hydrogen production (P), maximum hydrogen production rate (Rmax) and lag phases (λ) were analyzed using modified Gompertz model. Results revealed that both the biosurfactants were effective in hydrogen production enhancement. The maximum cumulative hydrogen production of 743.5±14.4ml and 675.6±12.1ml and volumetric hydrogen production of 2.12L H2 /L substrate and 1.93L H2 /L substrate was recorded at 3.5% surfactin and 3.0% saponin respectively. Corresponding highest hydrogen yields were 79.2mlH 2 /gCarbo initial and 72.0mlH 2 /gCarbo initial respectively. Lag phase decreased from 12.5±2.0h at control to a minimum of 9.0±2.8h and 9.5±2.1h at 3.5% surfactin and 3.0% saponin respectively. Volatile fatty acid generation was increased with biosurfactants addition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design of hydrogen fueling station for Vancouver BC

International Nuclear Information System (INIS)

Tura, A.; Dikeos, J.; St Germain, L.; Smolak, T.; Owen, T.; Hass, J.; Songprakorp, R.; Sodouri, P.; Maddaloni, J.

2004-01-01

'Full text:' A public hydrogen refueling station has been designed to service a minimum daily capacity of 50 light-duty hydrogen fuel cell vehicles, each requiring 3 kg of compressed gaseous hydrogen at 5000 psi. The station can accommodate a peak hourly fueling rate of 20 kg, or slightly less than 7 cars. The station is designed around liquid hydrogen, and energy efficient liquid compression. On-site storage with centralized production allows for great flexibility in the design and the simple fueling process results in fewer potential failure modes. High customer demand can easily be accommodated due to a four minute filling time, made possible by a low temperature hydrogen filling system. The overall well to wheel pathway of this fueling process generates up to 95% less CO2 and requires up to 42% less energy than gasoline. The proposed design requires a low capital investment, and uses components easily available from a proven supplier base. An economic analysis shows that the delivered hydrogen cost is between $0.11/mile and $0.18/mile, based on a ten year discounted cash flow analysis. This design was the grand prize winner in the NHA/DOE sponsored 2004 University Design Contest. (author)

Solar powered hydrogen generating facility and hydrogen powered vehicle fleet. Final technical report, August 11, 1994--January 6, 1997

Energy Technology Data Exchange (ETDEWEB)

Provenzano, J.J.

1997-04-01

This final report describes activities carried out in support of a demonstration of a hydrogen powered vehicle fleet and construction of a solar powered hydrogen generation system. The hydrogen generation system was permitted for construction, constructed, and permitted for operation. It is not connected to the utility grid, either for electrolytic generation of hydrogen or for compression of the gas. Operation results from ideal and cloudy days are presented. The report also describes the achievement of licensing permits for their hydrogen powered trucks in California, safety assessments of the trucks, performance data, and information on emissions measurements which demonstrate performance better than the Ultra-Low Emission Vehicle levels.

On Secondary Electron Emission from Solid H2 and D2

DEFF Research Database (Denmark)

Schou, Jørgen; Sørensen, H.

1978-01-01

The emission of secondary electrons from solid hydrogen (H2 , D2, T2) is often considered to be of importance for the interaction between a fusion plasma and pellets of solid hydrogens. A set-up was therefore built for studies of interactions between energetic particles and solid hydrogens. Studies...... of secondary electron emission (SEE) from solid H2 and D2 were made for incidence of electrons up to 3 keV and for incidence of ions of hydrogen, deuterium, and helium up to 10 keV. The measurements were made for normal incidence, and in some cases also for oblique incidence. The SEE coefficients for solid H2...... is always 0.65-0.70 times that for solid D2. This difference is attributed to different losses to vibrational states in H2 and D2 for the low energy electrons. Measurements were also made on solid para-H2 with both electrons and hydrogen ions. There was no difference from the results for normal H2, which...

Ablation of Solid Hydrogen in a Plasma

DEFF Research Database (Denmark)

Jørgensen, L. W.; Sillesen, Alfred Hegaard

1979-01-01

Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment.......Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment....

Dual mechanical behaviour of hydrogen in stressed silicon nitride thin films

International Nuclear Information System (INIS)

Volpi, F.; Braccini, M.; Pasturel, A.; Devos, A.; Raymond, G.; Morin, P.

2014-01-01

In the present article, we report a study on the mechanical behaviour displayed by hydrogen atoms and pores in silicon nitride (SiN) films. A simple three-phase model is proposed to relate the physical properties (stiffness, film stress, mass density, etc.) of hydrogenated nanoporous SiN thin films to the volume fractions of hydrogen and pores. This model is then applied to experimental data extracted from films deposited by plasma enhanced chemical vapour deposition, where hydrogen content, stress, and mass densities range widely from 11% to 30%, −2.8 to 1.5 GPa, and 2.0 to 2.8 g/cm 3 , respectively. Starting from the conventional plotting of film's Young's modulus against film porosity, we first propose to correct the conventional calculation of porosity volume fraction with the hydrogen content, thus taking into account both hydrogen mass and concentration. The weight of this hydrogen-correction is found to evolve linearly with hydrogen concentration in tensile films (in accordance with a simple “mass correction” of the film density calculation), but a clear discontinuity is observed toward compressive stresses. Then, the effective volume occupied by hydrogen atoms is calculated taking account of the bond type (N-H or Si-H bonds), thus allowing a precise extraction of the hydrogen volume fraction. These calculations applied to tensile films show that both volume fractions of hydrogen and porosity are similar in magnitude and randomly distributed against Young's modulus. However, the expected linear dependence of the Young's modulus is clearly observed when both volume fractions are added. Finally, we show that the stiffer behaviour of compressive films cannot be only explained on the basis of this (hydrogen + porosity) volume fraction. Indeed this stiffness difference relies on a dual mechanical behaviour displayed by hydrogen atoms against the film stress state: while they participate to the stiffness in compressive films, hydrogen atoms mainly

Composition variability of the organic fraction of municipal solid waste and effects on hydrogen and methane production potentials.

Science.gov (United States)

Alibardi, Luca; Cossu, Raffaello

2015-02-01

The composition of the Organic Fraction of Municipal Solid Waste (OFMSW) strongly depends on the place and time of collection for a specific municipality or area. Moreover synthetic food waste or organic waste from cafeterias and restaurants may not be representative of the overall OFMSW received at treatment facilities for source-separated waste. This work is aimed at evaluating the composition variability of OFMSW, the potential productions of hydrogen and methane from specific organic waste fractions typically present in MSW and the effects of waste composition on overall hydrogen and methane yields. The organic waste fractions considered in the study were: bread-pasta, vegetables, fruits, meat-fish-cheese and undersieve 20mm. Composition analyses were conducted on samples of OFMSW that were source segregated at household level. Batch tests for hydrogen and methane productions were carried out under mesophilic conditions on selected fractions and OFMSW samples. Results indicated that the highest production of hydrogen was achieved by the bread-pasta fraction while the lowest productions were measured for the meat-fish-cheese fraction. The results indicated that the content of these two fractions in organic waste had a direct influence on the hydrogen production potentials of OFMSW. The higher the content of bread-pasta fraction, the higher the hydrogen yields were while the contrary was observed for the meat-fish-cheese fraction. The definition of waste composition therefore represents fundamental information to be reported in scientific literature to allow data comparison. The variability of OFMSW and its effects on hydrogen potentials might also represents a problematic issue in the management of pilot or full-scale plants for the production of hydrogen by dark fermentation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of solid solution of hydrogen in α-manganese by neutron diffraction and inelastic neutron scattering

International Nuclear Information System (INIS)

Fedotov, V.K.; Antonov, V.E.; Kolesnikov, A.I.; Kornell, K.; Vipf, G.; Grosse, G.; Vagner, F.Eh.; Sikolenko, V.V.; Sumin, V.V.; )

1997-01-01

The FCC-lattice of the solid solution α-MnH 0.073 with the mass of 8.45 g is investigated by the neutron diffraction method and the inelastic neutron scattering technique. The neutron diffraction measurements are made by the diffractometer D1B with pyrographite monochromator and the high-resolution Fourier diffractometer HRFD at 300 K. The study of the inelastic incoherent neutron scattering is carried out by means of the inverse geometry spectrometer KDSOG-M at 90 K. The comparative analysis of α-MnH 0.073 and α-Mn spectra is fulfilled for the more correct separation of effects of hydrogen introduction. It is found out that the structure of the solid solution α-MnH 0.073 belongs to the same spatial group I-43m as the structure of α-Mn [ru

Solvent fractionation of rambutan (Nephelium lappaceum L. kernel fat for production of non-hydrogenated solid fat: Influence of time and solvent type

Directory of Open Access Journals (Sweden)

Busakorn Mahisanunt

2017-01-01

Full Text Available The present study performed isothermal (25 °C solvent fractionation of rambutan (Nephelium lappaceum L. kernel fat (RKF to obtain the fat fraction that had melting properties comparable to a commercial hydrogenated solid fat. The effect of two fractionation parameters, holding time (12, 18 and 24 h and solvent types (acetone and ethanol, on the properties of fractionated fat were investigated. The results showed that a fractionation time increase caused an increased yield and decreased iodine value for the high melting or stearin fractions. The thermal behaviors and solid fat index (SFI of these stearin fractions were different from the original fat, especially for stearin from acetone fractionation. The major fatty acid in this stearin fraction was arachidic acid (C20:0 consisting of more than 90%. Overall, we demonstrated that acetone fractionation of RKF at 25 °C for 24 h is effective for producing a solid fat fraction, which has comparable crystallizing and melting properties to commercial hydrogenated fat. The fractionated rambutan fat obtained by this process may lead to its potential use in specific food products.

Low Cost, High Efficiency, High Pressure Hydrogen Storage

Energy Technology Data Exchange (ETDEWEB)

Mark Leavitt

2010-03-31

A technical and design evaluation was carried out to meet DOE hydrogen fuel targets for 2010. These targets consisted of a system gravimetric capacity of 2.0 kWh/kg, a system volumetric capacity of 1.5 kWh/L and a system cost of $4/kWh. In compressed hydrogen storage systems, the vast majority of the weight and volume is associated with the hydrogen storage tank. In order to meet gravimetric targets for compressed hydrogen tanks, 10,000 psi carbon resin composites were used to provide the high strength required as well as low weight. For the 10,000 psi tanks, carbon fiber is the largest portion of their cost. Quantum Technologies is a tier one hydrogen system supplier for automotive companies around the world. Over the course of the program Quantum focused on development of technology to allow the compressed hydrogen storage tank to meet DOE goals. At the start of the program in 2004 Quantum was supplying systems with a specific energy of 1.1-1.6 kWh/kg, a volumetric capacity of 1.3 kWh/L and a cost of $73/kWh. Based on the inequities between DOE targets and Quantum’s then current capabilities, focus was placed first on cost reduction and second on weight reduction. Both of these were to be accomplished without reduction of the fuel system’s performance or reliability. Three distinct areas were investigated; optimization of composite structures, development of “smart tanks” that could monitor health of tank thus allowing for lower design safety factor, and the development of “Cool Fuel” technology to allow higher density gas to be stored, thus allowing smaller/lower pressure tanks that would hold the required fuel supply. The second phase of the project deals with three additional distinct tasks focusing on composite structure optimization, liner optimization, and metal.

Pressure-induced amorphization and reactivity of solid dimethyl acetylene probed by in situ FTIR and Raman spectroscopy

Science.gov (United States)

Guan, Jiwen; Daljeet, Roshan; Kieran, Arielle; Song, Yang

2018-06-01

Conjugated polymers are prominent semiconductors that have unique electric conductivity and photoluminescence. Synthesis of conjugated polymers under high pressure is extremely appealing because it does not require a catalyst or solvent used in conventional chemical methods. Transformation of acetylene and many of its derivatives to conjugated polymers using high pressure has been successfully achieved, but not with dimethyl acetylene (DMA). In this work, we present a high-pressure study on solid DMA using a diamond anvil cell up to 24.4 GPa at room temperature characterized by in situ Fourier transform infrared and Raman spectroscopy. Our results show that solid DMA exists in a phase II crystal structure and is stable up to 12 GPa. Above this pressure, amorphization was initiated and the process was completed at 24.4 GPa. The expected polymeric transformation was not evident upon compression, but only observed upon decompression from a threshold compression pressure (e.g. 14.4 GPa). In situ florescence measurements suggest excimer formation via crystal defects, which induces the chemical reactions. The vibrational spectral analysis suggests the products contain the amorphous poly(DMA) and possibly additional amorphous hydrogenated carbon material.

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

Science.gov (United States)

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

2015-11-20

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

Researches concerning the use of mixed Hydrogen in the combustion of dense biomass

International Nuclear Information System (INIS)

Negreanu, Gabriel-Paul; Mihaescu, Lucian; Pisa, Ionel; Berbece, Viorel; Lazaroiu, Gheorghe

2014-01-01

The paper deals with theoretical basis and experimental tests of mixed hydrogen diffusion in the dense system of biomass. Research regarding hydrogen diffusion in the porous system of biomass is part of wider research focusing on using hydrogen as an active medium for solid biomass combustion. In parallel with hydrogen diffusion in solid biomass, tests regarding biomass combustion previously subjected to a hydrogen flux will be carried out. Keywords: biomass, hydrogen diffusion, combustion, experimental tests

Hydrogen storage in insulated pressure vessels

Energy Technology Data Exchange (ETDEWEB)

Aceves, S.M.; Garcia-Villazana, O. [Lawrence Livermore National Lab., CA (United States)

1998-08-01

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

Free compression tube. Applications

Science.gov (United States)

Rusu, Ioan

2012-11-01

During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

Isotope exchange between gaseous hydrogen and uranium hydride powder

International Nuclear Information System (INIS)

Shugard, Andrew D.; Buffleben, George M.; Johnson, Terry A.; Robinson, David B.

2014-01-01

Highlights: • Isotope exchange between hydrogen gas and uranium hydride powder can be rapid and reversible. • Gas–solid exchange rate is controlled by transport within ∼0.7 μm hydride particles. • Gas chromatographic separation of hydrogen isotopes using uranium hydride is feasible. - Abstract: Isotope exchange between gaseous hydrogen and solid uranium hydride has been studied by flowing hydrogen (deuterium) gas through packed powder beds of uranium deuteride (hydride). We used a residual gas analyzer system to perform real-time analysis of the effluent gas composition. We also developed an exchange and transport model and, by fitting it to the experimental data, extracted kinetic parameters for the isotope exchange reaction. Our results suggest that, from approximately 70 to 700 kPa and 25 to 400 °C, the gas-to-solid exchange rate is controlled by hydrogen and deuterium transport within the ∼0.7 μm diameter uranium hydride particles. We use our kinetic parameters to show that gas chromatographic separation of hydrogen and deuterium using uranium hydride could be feasible

Contribution of collagen fibers to the compressive stiffness of cartilaginous tissues.

Science.gov (United States)

Römgens, Anne M; van Donkelaar, Corrinus C; Ito, Keita

2013-11-01

Cartilaginous tissues such as the intervertebral disk are predominantly loaded under compression. Yet, they contain abundant collagen fibers, which are generally assumed to contribute to tensile loading only. Fiber tension is thought to originate from swelling of the proteoglycan-rich nucleus. However, in aged or degenerate disk, proteoglycans are depleted, whereas collagen content changes little. The question then rises to which extend the collagen may contribute to the compressive stiffness of the tissue. We hypothesized that this contribution is significant at high strain magnitudes and that the effect depends on fiber orientation. In addition, we aimed to determine the compression of the matrix. Bovine inner and outer annulus fibrosus specimens were subjected to incremental confined compression tests up to 60 % strain in radial and circumferential direction. The compressive aggregate modulus was determined per 10 % strain increment. The biochemical composition of the compressed specimens and uncompressed adjacent tissue was determined to compute solid matrix compression. The stiffness of all specimens increased nonlinearly with strain. The collagen-rich outer annulus was significantly stiffer than the inner annulus above 20 % compressive strain. Orientation influenced the modulus in the collagen-rich outer annulus. Finally, it was shown that the solid matrix was significantly compressed above 30 % strain. Therefore, we concluded that collagen fibers significantly contribute to the compressive stiffness of the intervertebral disk at high strains. This is valuable for understanding the compressive behavior of collagen-reinforced tissues in general, and may be particularly relevant for aging or degenerate disks, which become more fibrous and less hydrated.

Design and prototyping of an ionic liquid piston compressor as a new generation of compressors for hydrogen refueling stations

DEFF Research Database (Denmark)

Arjomand Kermani, Nasrin

to investigate the heat transfer phenomena inside the compression chamber; the system performance is evaluated, followed by the design process. The model is developed based on the mass and energy balance of the hydrogen, and liquid bounded by the wall of the compression chamber. Therefore, at each time step...... and positional node, the model estimates the pressure and temperature of the hydrogen and liquid, the temperature of the compression chamber wall, and the amount of heat extracted from the hydrogen directly at the interface between the hydrogen and liquid, and through the wall. The results indicate......, fabrication, and control of the prototype is described in the presented work. The new compressor design has high potential to be used as an alternative to the conventional reciprocating compressors in hydrogen refueling stations, as it provides a simpler design with lower manufacturing costs, higher...

Hydrogen enriched compressed natural gas (HCNG: A futuristic fuel for internal combustion engines

Directory of Open Access Journals (Sweden)

Nanthagopal Kasianantham

2011-01-01

Full Text Available Air pollution is fast becoming a serious global problem with increasing population and its subsequent demands. This has resulted in increased usage of hydrogen as fuel for internal combustion engines. Hydrogen resources are vast and it is considered as one of the most promising fuel for automotive sector. As the required hydrogen infrastructure and refueling stations are not meeting the demand, widespread introduction of hydrogen vehicles is not possible in the near future. One of the solutions for this hurdle is to blend hydrogen with methane. Such types of blends take benefit of the unique combustion properties of hydrogen and at the same time reduce the demand for pure hydrogen. Enriching natural gas with hydrogen could be a potential alternative to common hydrocarbon fuels for internal combustion engine applications. Many researchers are working on this for the last few years and work is now focused on how to use this kind of fuel to its maximum extent. This technical note is an assessment of HCNG usage in case of internal combustion engines. Several examples and their salient features have been discussed. Finally, overall effects of hydrogen addition on an engine fueled with HCNG under various conditions are illustrated. In addition, the scope and challenges being faced in this area of research are clearly described.

On the Representation of Aquifer Compressibility in General Subsurface Flow Codes: How an Alternate Definition of Aquifer Compressibility Matches Results from the Groundwater Flow Equation

Science.gov (United States)

Birdsell, D.; Karra, S.; Rajaram, H.

2017-12-01

The governing equations for subsurface flow codes in deformable porous media are derived from the fluid mass balance equation. One class of these codes, which we call general subsurface flow (GSF) codes, does not explicitly track the motion of the solid porous media but does accept general constitutive relations for porosity, density, and fluid flux. Examples of GSF codes include PFLOTRAN, FEHM, STOMP, and TOUGH2. Meanwhile, analytical and numerical solutions based on the groundwater flow equation have assumed forms for porosity, density, and fluid flux. We review the derivation of the groundwater flow equation, which uses the form of Darcy's equation that accounts for the velocity of fluids with respect to solids and defines the soil matrix compressibility accordingly. We then show how GSF codes have a different governing equation if they use the form of Darcy's equation that is written only in terms of fluid velocity. The difference is seen in the porosity change, which is part of the specific storage term in the groundwater flow equation. We propose an alternative definition of soil matrix compressibility to correct for the untracked solid velocity. Simulation results show significantly less error for our new compressibility definition than the traditional compressibility when compared to analytical solutions from the groundwater literature. For example, the error in one calculation for a pumped sandstone aquifer goes from 940 to <70 Pa when the new compressibility is used. Code users and developers need to be aware of assumptions in the governing equations and constitutive relations in subsurface flow codes, and our newly-proposed compressibility function should be incorporated into GSF codes.

Stuart Energy's experiences in developing 'Hydrogen Energy Station' infrastructure

International Nuclear Information System (INIS)

Crilly, B.

2004-01-01

'Full text:' With over 50 years experience, Stuart Energy is the global leader in the development, manufacture and integration of multi-use hydrogen infrastructure products that use the Company's proprietary IMET hydrogen generation water electrolysis technology. Stuart Energy offers its customers the power of hydrogen through its integrated Hydrogen Energy Station (HES) that provides clean, secure and distributed hydrogen. The HES can be comprised of five modules: hydrogen generation, compression, storage, fuel dispensing and / or power generation. This paper discusses Stuart Energy's involvement with over 10 stations installed in recent years throughout North America, Asia and Europe while examining the economic and environmental benefits of these systems. (author)

Downstream processing of a ternary amorphous solid dispersion: The impacts of spray drying and hot melt extrusion on powder flow, compression and dissolution.

Science.gov (United States)

Davis, Mark T; Potter, Catherine B; Walker, Gavin M

2018-06-10

Downstream processing aspects of a stable form of amorphous itraconazole exhibiting enhanced dissolution properties were studied. Preparation of this ternary amorphous solid dispersion by either spray drying or hot melt extrusion led to significantly different powder processing properties. Particle size and morphology was analysed using scanning electron microscopy. Flow, compression, blending and dissolution were studied using rheometry, compaction simulation and a dissolution kit. The spray dried material exhibited poorer flow and reduced sensitivity to aeration relative to the milled extrudate. Good agreement was observed between differing forms of flow measurement, such as Flow Function, Relative flow function, Flow rate index, Aeration rate, the Hausner ratio and the Carr index. The stability index indicated that both powders were stable with respect to agglomeration, de-agglomeration and attrition. Tablet ability and compressibility studies showed that spray dried material could be compressed into stronger compacts than extruded material. Blending of the powders with low moisture, freely-flowing excipients was shown to influence both flow and compression. Porosity studies revealed that blending could influence the mechanism of densification in extrudate and blended extrudate formulations. Following blending, the powders were compressed into four 500 mg tablets, each containing a 100 mg dose of amorphous itraconazole. Dissolution studies revealed that the spray dried material released drug faster and more completely and that blending excipients could further influence the dissolution rate. Copyright © 2018 Elsevier B.V. All rights reserved.

A prediction study of a spark ignition supercharged hydrogen engine

International Nuclear Information System (INIS)

Al-Baghdadi, Maher A.R. Sadiq.; Al-Janabi, Haroun A.K. Shahad

2003-01-01

Hydrogen is found to be a suitable alternative fuel for spark ignition engines with certain drawbacks, such as high NO x emission and small power output. However, supercharging may solve such problems. In this study, the effects of equivalence ratio, compression ratio and inlet pressure on the performance and NO x emission of a four stroke supercharged hydrogen engine have been analyzed using a specially developed computer program. The results are verified and compared with experimental data obtained from tests on a Ricardo E6/US engine. A chart specifying the safe operation zone of the hydrogen engine has been produced. The safe operation zone means no pre-ignition, acceptable NO x emission, high engine efficiency and lower specific fuel consumption in comparison with the gasoline engine. The study also shows that supercharging is a more effective method to increase the output of a hydrogen engine rather than increasing the compression ratio of the engine at the knock limited equivalence ratio

A prediction study of a spark ignition supercharged hydrogen engine

Energy Technology Data Exchange (ETDEWEB)

Al-Baghdadi, M.A.R.S.; Al-Janabi, H.A.K.S. [University of Babylon (Iraq). Dept. of Mechanical Engineering

2003-12-01

Hydrogen is found to be a suitable alternative fuel for spark ignition engines with certain drawbacks, such as high NO{sub x} emission and small power output. However, supercharging may solve such problems. In this study, the effects of equivalence ratio, compression ratio and inlet pressure on the performance and NO{sub x} emission of a four stroke supercharged hydrogen engine have been analyzed using a specially developed computer program. The results are verified and compared with experimental data obtained from tests on a Ricardo E6/US engine. A chart specifying the safe operation zone of the hydrogen engine has been produced. The safe operation zone means no pre-ignition, acceptable NO{sub x} emission, high engine efficiency and lower specific fuel consumption in comparison with the gasoline engine. The study also shows that supercharging is a more effective method to increase the output of a hydrogen engine rather than increasing the compression ratio of the engine at the knock limited equivalence ratio. (author)

Effect of raw material ratios on the compressive strength of magnesium potassium phosphate chemically bonded ceramics

International Nuclear Information System (INIS)

Wang, Ai-juan; Yuan, Zhi-long; Zhang, Jiao; Liu, Lin-tao; Li, Jun-ming; Liu, Zheng

2013-01-01

The compressive strength of magnesium potassium phosphate chemically bonded ceramics is important in biomedical field. In this work, the compressive strength of magnesium potassium phosphate chemically bonded ceramics was investigated with different liquid-to-solid and MgO-to-KH 2 PO 4 ratios. X-ray diffractometer was applied to characterize its phase composition. The microstructure was imaged using a scanning electron microscope. The results showed that the compressive strength of the chemically bonded ceramics increased with the decrease of liquid-to-solid ratio due to the change of the packing density and the crystallinity of hydrated product. However, with the increase of MgO-to-KH 2 PO 4 weight ratio, its compressive strength increased firstly and then decreased. The low compressive strength in lower MgO-to-KH 2 PO 4 ratio might be explained by the existence of the weak phase KH 2 PO 4 . However, the low value of compressive strength with the higher MgO-to-KH 2 PO 4 ratio might be caused by lack of the joined phase in the hydrated product. Besides, it has been found that the microstructures were different in these two cases by the scanning electron microscope. Colloidal structure appeared for the samples with lower liquid-to-solid and higher MgO-to-KH 2 PO 4 ratios possibly because of the existence of amorphous hydrated products. The optimization of both liquid-to-solid and MgO-to-KH 2 PO 4 ratios was important to improve the compressive strength of magnesium potassium phosphate chemically bonded ceramics. - Highlights: • High packing density and amorphous hydrated phase improved the compressive strength. • Residual KH 2 PO 4 and poor bonding phase lower the compressive strength. • MPCBC fabricated with optimized parameters had the highest compressive strength

Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

Energy Technology Data Exchange (ETDEWEB)

Bernard, St

1998-12-31

The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

Energy Technology Data Exchange (ETDEWEB)

Bernard, St

1999-12-31

The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

Latent hazard related to a hydrogen liquefaction installation

International Nuclear Information System (INIS)

Spoendlin, R.

1961-01-01

In this note, the author reports an attempt of analysis of hazards which could be related to a hydrogen liquefaction installation in order to identify the most appropriate safety measures. In order to do so, experiments have been performed on electrostatic charges born by solid crystals in liquid hydrogen, and explosion tests have been performed on a mixture of solid oxygen and liquid hydrogen. Moreover, the author tried to analyse accidents which occurred in this field by performing a survey among scientists working in laboratories in different countries

Solid hydrogen structure

International Nuclear Information System (INIS)

Collins, G.W.; Unites, W.G.; Mapoles, E.R.; Magnotta, F.; Bernat, T.P.

1994-11-01

The J=0->2 Raman signal from solid J=0 D 2 or H 2 reveals HCP structure when deposited at a rate 0.1 ≤ R(μ/min) ≤ 40 onto MgF 2 at T d /T tp > 0.3, a mixture of HCP and FCC crystals at 0.2 d /T tp d /T tp tp is the triple point temperature. Non-HCP crystals transform to HCP continuously and irreversibly with increasing T. Finally, the crystal size decreases with decreasing T d and increasing R, from ∼ 1 mm at T d ∼ 0.8 T tp and R ∼ 2 μ/min to ∼ 1 μm at 0.25 T tp and R ∼ 40 μ/min

Hydrogen generation using silicon nanoparticles and their mixtures with alkali metal hydrides

Science.gov (United States)

Patki, Gauri Dilip

Hydrogen is a promising energy carrier, for use in fuel cells, engines, and turbines for transportation or mobile applications. Hydrogen is desirable as an energy carrier, because its oxidation by air releases substantial energy (thermally or electrochemically) and produces only water as a product. In contrast, hydrocarbon energy carriers inevitably produce CO2, contributing to global warming. While CO2 capture may prove feasible in large stationary applications, implementing it in transportation and mobile applications is a daunting challenge. Thus a zero-emission energy carrier like hydrogen is especially needed in these cases. Use of H2 as an energy carrier also brings new challenges such as safe handling of compressed hydrogen and implementation of new transport, storage, and delivery processes and infrastructure. With current storage technologies, hydrogen's energy per volume is very low compared to other automobile fuels. High density storage of compressed hydrogen requires combinations of high pressure and/or low temperature that are not very practical. An alternative for storage is use of solid light weight hydrogenous material systems which have long durability, good adsorption properties and high activity. Substantial research has been conducted on carbon materials like activated carbon, carbon nanofibers, and carbon nanotubes due to their high theoretical hydrogen capacities. However, the theoretical values have not been achieved, and hydrogen uptake capacities in these materials are below 10 wt. %. In this thesis we investigated the use of silicon for hydrogen generation. Hydrogen generation via water oxidation of silicon had been ignored due to slow reaction kinetics. We hypothesized that the hydrogen generation rate could be improved by using high surface area silicon nanoparticles. Our laser-pyrolysis-produced nanoparticles showed surprisingly rapid hydrogen generation and high hydrogen yield, exceeding the theoretical maximum of two moles of H2 per

Neutronographic measurements of the motion of hydrogen and hydrogeneous substances in liquids and solids

International Nuclear Information System (INIS)

Zeilinger, A.; Pochman, W.A.; Rauch, H.; Suleiman, M.

1976-01-01

Earlier measurements of hydrogen motion in liquids by neutron radiography have been extended to obtain additional parameters of governing the mixing behavior of light and heavy water. Furthermore motion of water in concrete was measured leading to a determination of (1) the vapor diffusion coefficient of water in concrete, (2) the porosity of the concrete, and (3) the mass transfer coefficient of vapor from the concrete to the environment. Recently the ability of neutron radiography to measure the hydrogen motion in metals was demonstrated and the diffusion coefficients of hydrogen in V, Ta, Nb and beta-Ti was determined. In addition, some work on resolution measurements of neutron radiography will be reported. (author)

Hydrogen diffusion, dissolution and permeation of nonmetallic solids

International Nuclear Information System (INIS)

Elleman, T.S.; Rao, D.; Verghese, K.; Zumwalt, L.

1979-01-01

A review of hydrogen diffusion, dissolution and permeation in metal oxides, carbides, nitrides, halides and hydrides is presented. Results are organized by compound and an effort has been made to resolve differences between measured results where wide disparities exist. The document has been prepared to provide needed data for the development of fusion reactor blankets but the results should be generally useful in technologies that involve interactions between hydrogen and non-metals

Sputtering of solid deuterium by He-ions

DEFF Research Database (Denmark)

Schou, Jørgen; Stenum, B.; Pedrys, R.

2001-01-01

Sputtering of solid deuterium by bombardment of 3He+ and 4He+ ions was studied. Some features are similar to hydrogen ion bombardment of solid deuterium, but for the He-ions a significant contribution of elastic processes to the total yield can be identified. The thin-film enhancement is more pro...... pronounced than that for hydrogen projectiles in the same energy range....

Limits for hydrogen production of a solar - hydrogen system in Cuernavaca, Mexico

International Nuclear Information System (INIS)

Arriaga, H.L.G.; Gutierrez, S.L.; Cano, U.

2006-01-01

In this work experimental data are used in order to estimate the production of hydrogen as a function of irradiance of a direct-interconnection of solar panel system with a SPE (Solid Polymer Electrolyte) electrolyzer (also Solar-Hydrogen system). The solar - hydrogen system, consists of a photovoltaic solar array of 36 panels (75 Watts each) of monocrystalline silicon interconnected with an electrolyzer stack of 25 cells (around 100 cm 2 of geometrical area) with a maximum hydrogen production of 1 Nm 3 /h. By the use of voltage, current density, energy consumption values of the whole solar-hydrogen system, an average efficiency up to 5% was estimated and an average of 3,800 NL of hydrogen per day can be expected. Also the maximum hydrogen production for the months of July and December (sunniest and least sunny months in the location) is predicted. (authors)

Limits for hydrogen production of a solar - hydrogen system in Cuernavaca, Mexico

Energy Technology Data Exchange (ETDEWEB)

Arriaga, H.L.G.; Gutierrez, S.L.; Cano, U. [Instituto de Investigaciones Electricas Av. Reforma 113, col. Palmira c.p.62490 Cuernavaca Morelos (Mexico)

2006-07-01

In this work experimental data are used in order to estimate the production of hydrogen as a function of irradiance of a direct-interconnection of solar panel system with a SPE (Solid Polymer Electrolyte) electrolyzer (also Solar-Hydrogen system). The solar - hydrogen system, consists of a photovoltaic solar array of 36 panels (75 Watts each) of monocrystalline silicon interconnected with an electrolyzer stack of 25 cells (around 100 cm{sup 2} of geometrical area) with a maximum hydrogen production of 1 Nm{sup 3}/h. By the use of voltage, current density, energy consumption values of the whole solar-hydrogen system, an average efficiency up to 5% was estimated and an average of 3,800 NL of hydrogen per day can be expected. Also the maximum hydrogen production for the months of July and December (sunniest and least sunny months in the location) is predicted. (authors)

The study of microplasticity mechanism in Ti-50 wt.%Nb alloy with high hydrogen content

International Nuclear Information System (INIS)

Golovin, I.S.; Kollerov, M.U.; Schinaeva, E.V.

1996-01-01

The upper yield point (∼ 700 MPa) appears at the compression test curves (ε=0.024 sec -1 ) of b.c.c. Nb-50 wt.%Ti due to the increase of hydrogen content from 0 to 0.2 wt.% and more and leads to the non monotonous increase in compressive lower yield stress from 400 to 550 MPa. Taking into account close connection between macro- and microplasticity of metallic materials the low frequency (∼ 2 Hz) amplitude dependent internal friction (ADIF) spectrum (γ = 1. 60.10 -5 ) in hydrogenized Nb-50 wt.% Ti and Nb samples are studied. The ADIF investigation of the closed hysteresis loop ''loading-unloading'' shows the dependence of its width from the hydrogen content which evidences the fact of dislocation unpinning from hydrogen atmospheres in the 1/2 cycle of loading. The study of ADIF spectrum for samples with different hydrogen content before and after torsion deformation (γ ∼ 2%) shows the sharp increase of IF level at γ = 1. 10.10 -5 after ∼1 hour of natural ageing. At that time the ADIF curves change its shape from Γ-shape to U-shape. The amplitude range of the IF increase depends on the hydrogen content. It is the interaction of hydrogen atoms with dislocations that caused the above mentioned effect which has not been observed in hydrogen free samples. The time estimation for the formation of thermodynamically stable hydrogen atmospheres on dislocations shows that hydrogen atmospheres could not follow the dislocation during compressive tests and that leads to the upper yield point appearance. (orig.)

Highly compressible three-dimensional graphene hydrogel for foldable all-solid-state supercapacitor

Science.gov (United States)

Liu, Xianbin; Zou, Shuai; Liu, Kaixi; Lv, Chao; Wu, Ziping; Yin, Yanhong; Liang, Tongxiang; Xie, Zailai

2018-04-01

The fabrication of three-dimensional (3D) graphene-based macroscopic materials with superior mechanical and electrical properties for flexible energy storage devices is still extremely challenging. Here, we report a novel 3D graphene hydrogel decorated by the biomass phytic acid (PAGH) with developed porosity and strengthen mechanical property via hydrothermal and freeze-drying methods. The phytic acid molecules are intercalated into the graphene sheets, enabling robust network structure. This induces the formation of materials with larger specific surface area, lower density and enhanced compressive strength compared with pure GH. When directly employed as an electrode, the PAGH exhibits a high specific capacitance of 248.8 F g-1 at 1 A g-1 and excellent rate performance of 67.9% as current density increasing to 20 A g-1. Furthermore, the all-solid-state supercapacitor based PAGH can deliver outstanding cycle life (86.2% after cycling 10,000 times), glorious energy density (26.5 Wh kg-1) and power density (5135.1 W kg-1). The prepared device shows stable electrochemical behaviors at random bending angles. Therefore, the present work will open a new avenue to design and fabricate new flexible and portable graphene-based electrodes for future applications in energy storage devices.

Incineration of alpha-active solid waste by microwaves

Energy Technology Data Exchange (ETDEWEB)

Mallik, G K; Bhargava, V K; Kamath, H S; Purushotham, D S.C. [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

1996-12-31

The conventional techniques for treatment of alpha-active compressible solid waste involve incineration using electrically heated incinerators and subsequent recovery of special nuclear materials (SNM) from the ash by acid leaching. A microwave incineration followed by microwave digestion and SNM recovery from ash has specific advantages from maintenance and productivity consideration. The paper describes a preliminary work carried out with simulated uranium containing compressible solid waste using microwave heating technique. (author). 3 refs., 1 tab.

Use of compressed-air storage systems; Einsatz von Druckluftspeichersystemen

Energy Technology Data Exchange (ETDEWEB)

Cyphely, I.; Rufer, A.; Brueckmann, Ph.; Menhardt, W.; Reller, A.

2004-07-01

This final report issued by the Swiss Federal Office of Energy (SFOE) looks at the use of compressed air as a means of storing energy. Historical aspects are listed and compressed-air storage as an alternative to current ideas that use electrolysis and hydrogen storage is discussed. The storage efficiency advantages of compressed-air storage is stressed and the possibilities it offers for compensating the stochastic nature of electricity production from renewable energy sources are discussed. The so-called BOP (Battery with Oil-hydraulics and Pneumatics) principle for the storage of electricity is discussed and its function is described. The advantages offered by such a system are listed and the development focus necessary is discussed.

Hydrogen storage using microporous carbon materials

International Nuclear Information System (INIS)

B Buczek; E Wolak

2005-01-01

In the present century hydrogen will be the most important source of energy and will replace petroleum and petroleum-derived products in the next future. Hydrogen is an almost ideal fuel, both because of its unlimited accessibility and for ecological reasons; the product of its combustion - water vapour - is neither any gaseous contamination nor a component of greenhouse gases. Nowadays hydrogen is applied in industrial processes, but may be also used as a source of house lighting and heating energy, for production of electricity, and as fuel for car engines. Fuel cells, applying reaction between hydrogen and oxygen for production of electricity have been for a long time used in the space technology. Application of hydrogen as fuel should give a possibility of storage and transfer of the high quality energy, i.e. the energy of a high exo-energetic ratio. Due to its low density, one of the main obstacles to the widespread use of hydrogen in energy sector is an efficient storage technology. At present, the methods of hydrogen storage are to liquefy and store in refrigerated containers, which is very expensive, or to store it in high - pressure gas cylinders at room temperature. Unfortunately, low storage density of hydrogen for the latter technique is a significant drawback. Between alternatives have been considered (chemical storage in irreversible hydrogen carriers like methanol or ammonia, reversible metal and chemical hydrides and adsorption in porous media), the latter one seems to lie the most promising. Physical adsorption is a method by which more gas can be stored at a lower pressure by means of Van der Waals interactions at the gas solid interface. Adsorptive storage is particularly promising for permanent gases, which need to be stored, transported, or used in ambient temperature. Thanks to the high density of adsorbed phase, adsorptive storage system could allow the storage of a high density of hydrogen at much lower pressures than compression and higher

CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

International Nuclear Information System (INIS)

Grant L. Hawkes; James E. O'Brien; Carl M. Stoots; J. Stephen Herring

2005-01-01

A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL

Metal ammine complexes for hydrogen storage

DEFF Research Database (Denmark)

Christensen, Claus H.; Sørensen, Rasmus Zink; Johannessen, Tue

2005-01-01

The hopes of using hydrogen as an energy carrier are severely dampened by the fact that there is still no safe, high-density method available for storing hydrogen. We investigate the possibility of using metal ammine complexes as a solid form of hydrogen storage. Using Mg(NH3)(6)Cl-2 as the example......, we show that it can store 9.1% hydrogen by weight in the form of ammonia. The storage is completely reversible, and by combining it with an ammonia decomposition catalyst, hydrogen can be delivered at temperatures below 620 K....

Purification of hydrogen sulfide

International Nuclear Information System (INIS)

Tsao, U.

1978-01-01

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

Process, including PSA and membrane separation, for separating hydrogen from hydrocarbons

Science.gov (United States)

Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

2001-01-01

An improved process for separating hydrogen from hydrocarbons. The process includes a pressure swing adsorption step, a compression/cooling step and a membrane separation step. The membrane step relies on achieving a methane/hydrogen selectivity of at least about 2.5 under the conditions of the process.

Hydrogen-bond Specific Materials Modification in Group IV Semiconductors

Energy Technology Data Exchange (ETDEWEB)

Tolk, Norman H. [Vanderbilt Univ., Nashville, TN (United States); Feldman, L. C. [Vanderbilt Univ., Nashville, TN (United States); Luepke, G. [College of William and Mary, Williamsburg, VA (United States)

2015-09-14

impurity states under transient compression. This research focused on the characterization of photon and ion stimulated hydrogen related defect and impurity reactions and migration in solid state matter, which requires a detailed understanding of the rates and pathways of vibrational energy flow, of the transfer channels and of the coupling mechanisms between local vibrational modes (LVMs) and phonon bath as well as the electronic system of the host material. It should be stressed that researchers at Vanderbilt and William and Mary represented a unique group with a research focus and capabilities for low temperature creation and investigation of such material systems. Later in the program, we carried out a vigorous research effort addressing the roles of defects, interfaces, and dopants on the optical and electronic characteristics of semiconductor crystals, using phonon generation by means of ultrafast coherent acoustic phonon (CAP) spectroscopy, nonlinear characterization using second harmonic generation (SHG), and ultrafast pump-and-probe reflectivity and absorption measurements. This program featured research efforts from hydrogen defects in silicon alone to other forms of defects such as interfaces and dopant layers, as well as other important semiconducting systems. Even so, the emphasis remains on phenomena and processes far from equilibrium, such as hot electron effects and travelling localized phonon waves. This program relates directly to the mission of the Department of Energy. Knowledge of the rates and pathways of vibrational energy flow in condensed matter is critical for understanding dynamical processes in solids including electronically, optically and thermally stimulated defect and impurity reactions and migration. The ability to directly probe these pathways and rates allows tests of theory and scaling laws at new levels of precision. Hydrogen embedded in model crystalline semiconductors and metal oxides is of particular interest, since the associated

Impact of heavy metals on hydrogen production from organic fraction of municipal solid waste using co-culture of Enterobacter aerogenes and E. Coli.

Science.gov (United States)

Sharma, Preeti; Melkania, Uma

2018-05-01

In the present study, the effect of heavy metals (lead, mercury, copper, and chromium) on the hydrogen production from the organic fraction of municipal solid waste (OFMSW) was investigated using co-culture of facultative anaerobes Enterobacter aerogenes and E. coli. Heavy metals were applied at concentration range of 0.5, 1, 2, 5, 10, 20, 50 and 100 mg/L. The results revealed that lead, mercury, and chromium negatively affected hydrogen production for the range of concentrations applied. Application of copper slightly enhanced hydrogen production at low concentration and resulted in the hydrogen yield of 36.0 mLH 2 /gCarbo initial with 10 mg/L copper supplementation as compared to 24.2 mLH 2 /gCarbo initial in control. However, the higher concentration of copper (>10 mg/L) declined hydrogen production. Hydrogen production inhibition potential of heavy metals can be arranged in the following increasing order: Cu 2+  metal addition. Thus, the present study reveals that the presence of heavy metals in the feedstock is detrimental for the hydrogen production. Therefore, it is essential to remove the toxic heavy metals prior to anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ovonic Renewable Hydrogen (ORH) - low temperature hydrogen production from renewable fuels

International Nuclear Information System (INIS)

Reichman, B.; Mays, W.; Strebe, J.; Fetcenko, M.

2009-01-01

'Full text': ECD has developed a new technology to produce hydrogen from various organic matters. In this technology termed Ovonic Renewable Hydrogen (ORH), base material such as NaOH is used as a reactant to facilitate the reforming of the organic matters to hydrogen gas. This Base-Facilitated Reforming (BFR) process is a one-step process and has number of advantages over the conventional steam reforming and gasification processes including lower operation temperature and lower heat consumption. This paper will describe the ORH process and discuss its technological and economics advantages over the conventional hydrogen production processes. ORH process has been studied and demonstrated on variety of renewable fuels including liquid biofuels and solid biomass materials. Results of these studies will be presented. (author)

Bio-hydrogen Production Potential from Market Waste

Directory of Open Access Journals (Sweden)

Lanna Jaitalee

2010-07-01

Full Text Available This research studied bio-hydrogen production from vegetable waste from a fresh market in order to recover energy. A series of batch experiments were conducted to investigate the effects of initial volatile solids concentration on the bio-hydrogen production process. Lab bench scale anaerobic continuous stirred-tank reactors (CSTR were used to study the effect of substrate and sludge inoculation on hydrogen production. Three different concentrations of initial total volatile solids (TVS of organic waste were varied from 2%, 3% and 5% respectively. The pH was controlled at 5.5 for all batches in the experiment. The results showed that bio-hydrogen production depended on feed-substrate concentration. At initial TVS content of 3%, the highest hydrogen production was achieved at a level of 0.59 L-H2/L at pH 5.5. The maximum hydrogen yield was 15.3 ml H2/g TVS or 8.5 ml H2/g COD. The composition of H2 in the biogas ranged from 28.1-30.9% and no CH4 was detected in all batch tests.

Revisiting the Fundamentals and Capabilities of the Stack Compression Test

DEFF Research Database (Denmark)

Alves, L.M.; Nielsen, Chris Valentin; Martin, P.A.F.

2011-01-01

performance by comparing the flow curves obtained from its utilisation with those determined by means of compressive testing carried out on solid cylinder specimens of the same material. Results show that mechanical testing of materials by means of the stack compression test is capable of meeting...... the increasing demand of accurate and reliable flow curves for sheet metals....

Microstructure and kinetics evolution in MgH{sub 2}–TiO{sub 2} pellets after hydrogen cycling

Energy Technology Data Exchange (ETDEWEB)

Mirabile Gattia, D., E-mail: daniele.mirabile@enea.it; Di Girolamo, G.; Montone, A.

2014-12-05

Highlights: • MgH{sub 2} was ball milled with TiO{sub 2} anatase phase and expanded graphite to prepare pellets. • Different pellets have been prepared at different compression load. • Pellets were repeatedly cycled under hydrogen pressure to simulate tank exercise and verify their stability. • The compression load highly affects the stability of the pellets to cycling. • Microstructural evolution of the particles due to cycling have been observed. - Abstract: The interest in Mg-based hydrides for solid state hydrogen storage is associated to their capability to reversibly absorb and desorb large amounts of hydrogen. In this work MgH{sub 2} powder with 5 wt.% TiO{sub 2} was ball milled for 10 h. The as-milled nanostructured powder was enriched with 5 wt.% of Expanded Natural Graphite (ENG) and then compacted in cylindrical pellets by cold pressing using different loads. Both the powder and the pellets were subjected to kinetic and thermodynamic tests using a Sievert’s type gas reaction controller, in order to study the microstructural and kinetic changes which took place during repeated H{sub 2} absorption and desorption cycles. The pellets exhibited good kinetic performance and durability, even if the pressure of compaction revealed to be an important parameter for their mechanical stability. Scanning Electron Microscopy observations of as-prepared and cycled pellets were carried out to investigate the evolution of their microstructure. In turn the phase composition before and after cycling was analyzed by X-ray diffraction.

A novel accelerated oxidative stability screening method for pharmaceutical solids.

Science.gov (United States)

Zhu, Donghua Alan; Zhang, Geoff G Z; George, Karen L S T; Zhou, Deliang

2011-08-01

Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30°C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spectrophotometric method. The feasibility and utility of the proposed method in solid form selection have been demonstrated using various solid forms of ephedrine. No degradation was detected for ephedrine hydrochloride after exposure to the hydrogen peroxide vapor for 2 weeks, whereas both anhydrate and hemihydrate free base forms degraded rapidly under the test conditions. In addition, both the anhydrate and the hemihydrate free base degraded faster when exposed to hydrogen peroxide vapor at 30°C under dry condition than at 30°C/75% relative humidity (RH). A new degradation product was also observed under the drier condition. The proposed method provides more relevant screening conditions for solid dosage forms, and is useful in selecting optimal solid form(s), determining potential degradation products, and formulation screening during development. Copyright © 2011 Wiley-Liss, Inc.

New nitrogen-containing materials for hydrogen storage and their characterization by high-pressure microbalance

DEFF Research Database (Denmark)

Vestbø, Andreas Peter

Hydrogen storage for practical applications is under intense scrutiny worldwide since hopes are prevalent of being able to use hydrogen as energy vector in a continually difficult time in terms of having access to clean and affordable energy in the world. Hydrogen can be stored in compressed or l...

Towards hydrogen metallization: an Ab initio approach

International Nuclear Information System (INIS)

Bernard, St.

1998-01-01

The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H 2 ) 2 which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author)

Ablation of Hydrogen Pellets in Hydrogen and Helium Plasmas

DEFF Research Database (Denmark)

Jørgensen, L W; Sillesen, Alfred Hegaard; Øster, Flemming

1975-01-01

Measurements on the interaction between solid hydrogen pellets and rotating plasmas are reported. The investigations were carried out because of the possibility of refuelling fusion reactors by the injection of pellets. The ablation rate found is higher than expected on the basis of a theory...

Design and exergetic analysis of a novel carbon free tri-generation system for hydrogen, power and heat production from natural gas, based on combined solid oxide fuel and electrolyser cells

Energy Technology Data Exchange (ETDEWEB)

Perdikaris, N.; Hofmann, Ph.; Spyrakis, S. [Laboratory of Steam Boilers and Thermal Plants, School of Mechanical Engineering, Thermal Engineering Section, National Technical University of Athens, 9 Heroon Polytechniou Ave., Zografou, 15780 Athens (Greece); Panopoulos, K.D. [Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 4th km N.R. Ptolemais-Kozani, P.O. Box 95, 50200 Ptolemais (Greece); Kakaras, E. [Laboratory of Steam Boilers and Thermal Plants, School of Mechanical Engineering, Thermal Engineering Section, National Technical University of Athens, 9 Heroon Polytechniou Ave., Zografou, 15780 Athens (Greece); Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 4th km N.R. Ptolemais-Kozani, P.O. Box 95, 50200 Ptolemais (Greece)

2010-03-15

The Solid Oxide Cells (SOCs) are able to operate in two modes: (a) the Solid Oxide Fuel Cells (SOFCs) that produce electricity and heat and (b) the Solid Oxide Electrolyser Cells (SOEC) that consume electricity and heat to electrolyse water and produce hydrogen and oxygen. The present paper presents a carbon free SOEC/SOFC combined system for the production of hydrogen, electricity and heat (tri-generation) from natural gas fuel. Hydrogen can be locally used as automobile fuel whereas the oxygen produced in the SOEC is used to combust the depleted fuel from the SOFC, which is producing electricity and heat from natural gas. In order to achieve efficient carbon capture in such a system, water steam should be used as the SOEC anode sweep gas, to allow the production of nitrogen free flue gases. The SOEC and SOFC operations were matched through modeling of all components in Aspenplus trademark. The exergetic efficiency of the proposed decentralised system is 28.25% for power generation and 18.55% for production of hydrogen. The system is (a) carbon free because it offers an almost pure pressurised CO{sub 2} stream to be driven for fixation via parallel pipelines to the natural gas feed, (b) does not require any additional water for its operation and (c) offers 26.53% of its energetic input as hot water for applications. (author)

Hydrogen adsorption on partially oxidised microporous carbons

International Nuclear Information System (INIS)

J B Parra; C O Ania; C J Duran Valle; M L Sanchez; C Otero Arean

2005-01-01

The search for cost effective adsorbents for large scale gas separation, storage and transport constitutes a present day strategic issue in the energy sector, propelled mainly by the potential use of hydrogen as an energy vector in a sustainable (and cleaner) energy scenario. Both, activated carbons and carbon based nano-structured materials have been proposed as potential candidates for reversible hydrogen storage in cryogenically cooled vessels. For that purpose, surface modification so as to enhance the gas solid interaction energy is desirable. We report on hydrogen adsorption on microporous (active) carbons which have been partially oxidised with nitric acid and ammonium persulfate. From the corresponding hydrogen adsorption isotherms (Fig. 1) an isosteric heat of about 3 kJ mol -1 was derived. This value is in agreement with that of about 3 to 4 kJ mol -1 obtained by quantum chemical calculations on the interaction between the hydrogen molecule and simple model systems (Fig. 2) of both, hydroxyl and carboxyl groups. Further research is in progress with a view to further increases the gas solid interaction energy. However, the values so far obtained are significantly larger than the liquefaction enthalpy of hydrogen: 0.90 kJ mol -1 ; and this is relevant to both, hydrogen separation from gas mixtures and cryogenic hydrogen storage. (authors)

Improving the photovoltaic performance of the all-solid-state TiO2 NR/CuInS2 solar cell by hydrogen plasma treatment

Science.gov (United States)

Chen, Bingfeng; Niu, Wenzhe; Lou, Zirui; Ye, Zhizhen; Zhu, Liping

2018-07-01

The interfacial properties of the heterojunction between p-type and n-type materials play an important role in the performance of the solar cell. In this paper, a p-type CuInS2 film was deposited on TiO2 nanorod arrays by spin coating to fabricate an all-solid-state solar cell and the TiO2 nanorod arrays were treated with hydrogen plasma(H:TiO2) to ameliorate the interfacial properties. The influence of the hydrogen plasma treatment on the performance of the solar cell was investigated. The short-circuit current density was obviously raised and the power conversion efficiency of the solar cell improved to 0.30%, which is three times that of solar cells without hydrogen plasma treatment. The enhancement of the performance is attributed to not only the enhancement of carrier separation and transport, but the reduction of the recombination of electrons and holes, which is caused by hydrogen plasma treatment.

Improving the photovoltaic performance of the all-solid-state TiO2 NR/CuInS2 solar cell by hydrogen plasma treatment.

Science.gov (United States)

Chen, Bingfeng; Niu, Wenzhe; Lou, Zirui; Ye, Zhizhen; Zhu, Liping

2018-07-06

The interfacial properties of the heterojunction between p-type and n-type materials play an important role in the performance of the solar cell. In this paper, a p-type CuInS 2 film was deposited on TiO 2 nanorod arrays by spin coating to fabricate an all-solid-state solar cell and the TiO 2 nanorod arrays were treated with hydrogen plasma(H:TiO 2 ) to ameliorate the interfacial properties. The influence of the hydrogen plasma treatment on the performance of the solar cell was investigated. The short-circuit current density was obviously raised and the power conversion efficiency of the solar cell improved to 0.30%, which is three times that of solar cells without hydrogen plasma treatment. The enhancement of the performance is attributed to not only the enhancement of carrier separation and transport, but the reduction of the recombination of electrons and holes, which is caused by hydrogen plasma treatment.

Secondary electron emission from solid HD and a solid H2-D2 mixture

DEFF Research Database (Denmark)

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

1983-01-01

Secondary electron emission from solid HD and a solid 0.6 H2 + 0.4 D2 mixture has been studied for electron and hydrogen ion bombardment at primary energies from 0.5 to 3 keV and 2 to 10 keV/amu, respectively. The yield for solid HD is well explained by a simple stoichiometric model of the low...

Hydrogen fuel : well-to-pump pathways for 2050

Energy Technology Data Exchange (ETDEWEB)

Molburg, J. [Argonne National Lab., IL (United States); Mintz, M.; Folga, S.; Gillette, J.

2002-07-01

The authors discussed the topic of hydrogen fuels, and began the presentation by stating that the carbon intensity of world primary energy has been falling and hydrogen intensity has been rising. The declines in carbon can be explained by efficiency gains and fuel switches. There are several alternatives to gasoline fuel for vehicles, such as hydrogen, compressed natural gas, compressed natural gas/hydrogen. Emissions of greenhouse gases in the atmosphere represent a growing concern. The authors discussed four hydrogen pathways that have been modeled. They indicated that both natural gas pathways required additional natural gas transmission and storage. To better illustrate the hydrogen pathway, a conceptual representation of hydrogen pipeline loop supporting local hydrogen delivery was displayed. Some hydrogen distribution assumptions for centralized hydrogen production were examined. A cost modeling procedure was described, with the following topics: defining paths, determining tank-in fuel requirement, size pathway components, estimating component costs, and calculating pathway costs. The results indicated that the natural gas-based pathways were sensitive to feedstock cost, while coal and nuclear were not. Some of the conclusions that were arrived at were: (1) on a well-to-pump basis, with current technologies, the unit cost of hydrogen is expected to be 2 to 3 time that of gasoline, (2) the mpge of hydrogen-fueled vehicles must be more than double gasoline, and (3) hydrogen transport and production are the largest components of all pathways. For the future, the focus has to be on transition, including total and unit costs through study time frame, penetration of hydrogen blends, and niche markets. One must compare apples to apples, i e cost of infrastructure components over time, and learning curves. Pathways and scenarios must be re-examined, to include issues such as truck, rail marine market penetration; and hydrogen carrier pathways. Disruptive

A Discrete Approach to Meshless Lagrangian Solid Modeling

Directory of Open Access Journals (Sweden)

Matthew Marko

2017-07-01

Full Text Available The author demonstrates a stable Lagrangian solid modeling method, tracking the interactions of solid mass particles rather than using a meshed grid. This numerical method avoids the problem of tensile instability often seen with smooth particle applied mechanics by having the solid particles apply stresses expected with Hooke’s law, as opposed to using a smoothing function for neighboring solid particles. This method has been tested successfully with a bar in tension, compression, and shear, as well as a disk compressed into a flat plate, and the numerical model consistently matched the analytical Hooke’s law as well as Hertz contact theory for all examples. The solid modeling numerical method was then built into a 2-D model of a pressure vessel, which was tested with liquid water particles under pressure and simulated with smoothed particle hydrodynamics. This simulation was stable, and demonstrated the feasibility of Lagrangian specification modeling for fluid–solid interactions.

Hydrogenizing oils, asphalts, etc

Energy Technology Data Exchange (ETDEWEB)

1925-03-14

The hydrogenation of carbonaceous solids in presence of combined sulfur, e.g., sulfides as described in the parent specification is applied to the treatment of rock oils, shale oils, resins, ozokerite, asphalt, and the like, or fractions, residues, or acid sludge or other conversion products thereof, alone or mixed. Preferably the hydrogen or other reducing gas is in excess and under pressure, and is either circuited or led through a series of treatment vessels, hydrogen being added for that used. In an example, residues from American crude oil are passed continuously with hydrogen at 200 atmospheres and 450 to 500/sup 0/C over pressed precipitated cobalt sulfide, the issuing gases being cooled to condense the light oil produced.

Hydrogen storage in graphitic nanofibres

OpenAIRE

McCaldin, Simon Roger

2007-01-01

There is huge need to develop an alternative to hydrocarbons fuel, which does not produce CO2 or contribute to global warming - 'the hydrogen economy' is such an alternative, however the storage of hydrogen is the key technical barrier that must be overcome. The potential of graphitic nanofibres (GNFs) to be used as materials to allow the solid-state storage of hydrogen has thus been investigated. This has been conducted with a view to further developing the understanding of the mechanism(s) ...

Hydrogen with intrinsic CO{sub 2} sequestration: the ENI 'One Step Hydrogen' process

Energy Technology Data Exchange (ETDEWEB)

Rossini, S.; Cornaro, U.; Mizia, F.; Malandrino, A.; Piccoli, V. [Enitecnologie SpA, S. Donata Milanese (Italy); Sanfilippo, D.; Miracca, I. [Snamprogetti SpA, S. Donato Milanese (Italy)

2003-07-01

The new process, under development in our companies, is aimed to hydrogen production with intrinsic carbon dioxide sequestration. This is made possible combining in a cycle the water oxidative potential with a reverse action by a reducing agent like hydrocarbons, the preferred being natural gas. In the first step a suitable oxide takes up the oxygen from water splitting producing hydrogen. The solid act as an oxygen storage medium. Such 'lattice' oxygen is in turn released through one or more elemental steps. The process fits very well with a circulating fluid bed reactor which allows the movement of the solid from one reactive environment to the other. (orig.)

Hydrogen storage using borohydrides

International Nuclear Information System (INIS)

Bernard BONNETOT; Laetitia LAVERSENNE

2006-01-01

The possibilities of hydrogen storage using borohydrides are presented and discussed specially in regard of the recoverable hydrogen amount and related to the recovering conditions. A rapid analysis of storage possibilities is proposed taking in account the two main ways for hydrogen evolution: the dehydrogenation obtained through thermal decomposition or the hydrolysis of solids or solutions. The recoverable hydrogen is related to the dehydrogenation conditions and the real hydrogen useful percentage is determined for each case of use. The high temperature required for dehydrogenation even when using catalyzed compounds lead to poor outlooks for this storage way. The hydrolysis conditions direct the chemical yield of the water consuming, and this must be related to the experimental conditions which rule the storage capacity of the 'fuel' derived from the borohydride. (authors)

Development of ultra-short high voltage pulse technology using magnetic pulse compression

Energy Technology Data Exchange (ETDEWEB)

Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L

1998-01-01

The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs.

Development of ultra-short high voltage pulse technology using magnetic pulse compression

International Nuclear Information System (INIS)

Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L.

1998-01-01

The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs

Studies on keV and eV electrons in solids

International Nuclear Information System (INIS)

Schou, J.

1979-10-01

The interaction between keV or eV electrons and solids was studied. The results presented mostly concern problems in connection with electron irradiation of solids, but to some extent they also include ion-induced secondary electron emission. The experiments were mainly performed on solidified gases using 1 - 3 keV electrons. The projected range of electrons was determined in solid hydrogen, deuterium and nitrogen. The true secondary electron emission coefficient and the electron reflection coefficient of solid hydrogen, deuterium and nitrogen were measured. The escape depth of the true secondary electrons in nitrogen was determined. The angular dependence of both the reflection coefficient and the true secondary electron emission coefficient of solid hydrogen and deuterium was investigated. Both ion- and electron-induced secondary electron emission were treated theoretically on the basis of ionization cascade theory. (Auth.)

HYDROGEN IN THE EARTH’S OUTER CORE, AND ITS ROLE IN THE DEEP EARTH GEODYNAMICS

Directory of Open Access Journals (Sweden)

V. N. Rumyantsev

2016-01-01

Full Text Available The content of hydrogen in the outer core of the Earth is roughly quantified from the dependence of the density of iron (viewed as the main component of the core on the amount of hydrogen dissolved in the core, with account of the most likely presence of iron hydrogen in the outer core, and the matter’s density jumps at the boundaries between the outer liquid core and the internal solid core (that is devoid of hydrogen and the mantle. Estimations for the outer liquid core show that the hydrogen content varies from 0.67 wt. % at the boundary with the solid inner core to 3.04 wt. % at the boundary with the mantle.Iron occlusion is viewed as the most likely mechanism for the iron–nickel core to capture such a significant amount of hydrogen. Iron occlusion took place at the stage of the young sun when the metallic core emerged in the cooling protoplanetary cloud containing hydrogen in high amounts, and non-volatile hydrogen was accumulated. Absorption (occlusion of molecular hydrogen was preceded by dissociation of molecules into atoms and ionization of the atoms, as proved by results of studies focused on Fe–H2 system, and hydrogen dissipation was thus prevented. The core matter was subject to gravitational compression at high pressures that contributed to the forced rapprochement of protons and electrons which interaction resulted by the formation of hydrogen atoms. Highly active hydrogen atoms reacted with metals and produced hydrides of iron and nickel, FeH and NiH. While the metallic core and then the silicate mantle were growing and consolidating, the stability of FeH and NiH was maintained due to pressures that were steadily increasing. Later on, due to the impacts of external forces on the Earth, marginal layers at the mantle–core boundary were detached and displaced, pressures decreased in the system, and iron and nickel hydrides were decomposed to produce molecular hydrogen. Consequences of the hydrides transformation into

Analysis of a discrete element method and coupling with a compressible fluid flow method

International Nuclear Information System (INIS)

Monasse, L.

2011-01-01

This work aims at the numerical simulation of compressible fluid/deformable structure interactions. In particular, we have developed a partitioned coupling algorithm between a Finite Volume method for the compressible fluid and a Discrete Element method capable of taking into account fractures in the solid. A survey of existing fictitious domain methods and partitioned algorithms has led to choose an Embedded Boundary method and an explicit coupling scheme. We first showed that the Discrete Element method used for the solid yielded the correct macroscopic behaviour and that the symplectic time-integration scheme ensured the preservation of energy. We then developed an explicit coupling algorithm between a compressible inviscid fluid and an un-deformable solid. Mass, momentum and energy conservation and consistency properties were proved for the coupling scheme. The algorithm was then extended to the coupling with a deformable solid, in the form of a semi implicit scheme. Finally, we applied this method to unsteady inviscid flows around moving structures: comparisons with existing numerical and experimental results demonstrate the excellent accuracy of our method. (author) [fr

700 bar hydrogen cylinder design, testing and certification

International Nuclear Information System (INIS)

Duncan, M.

2004-01-01

'Full text:' Light weight and high pressure cylinders for compressed hydrogen storage are essential components for fuel cell vehicles. Storage volume and mass are two key considerations. Current on-board hydrogen storage systems are based on a maximum pressure of 350 bar. While 350 bar systems are excellent solutions for many applications, some situations required higher storage densities due to space restrictions. As a result significant research and development work has been expended by cylinder manufacturers, systems providers, testing agencies and automotive manufacturers to develop 700 bar systems to reduce storage volume. Dynetek Industries Ltd has proactively developed a range of 700 bar storage cylinders based on a seamless aluminum liner over wrapped with a carbon fiber composite. This paper presents the challenges and processes involved in the design, testing and certification of the Dynetek Industries Ltd 700 bar cylinder. The paper also provides reasoning for further volume and mass optimization of compressed hydrogen cylinders by incorporating realistic cylinder usage parameters into standards. In particular the overly conservative fill life requirement for cylinders will be examined. (author)

Solid-state amorphization of SmFe3 by hydrogenation

International Nuclear Information System (INIS)

Mueller, K.H.; Kubis, M.; Handstein, A.; Gutfleisch, O.

2000-01-01

Hydrogen-induced amorphization (HIA) has received much attention as a method for the preparation of amorphous compounds since its discovery by Yeh et al. Meanwhile it has been observed for a large number of intermetallic compounds with C15, C23, B8 2 , DO 19 and L1 2 structures. E.G. the C15 Laves-type compounds (MgCu 2 -type structure) of rare earth (R) - transition metal (T) compounds RT 2 show HIA for R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er. Aoki et al. postulated that new amorphizing compounds can be expected at high hydrogen pressures. In this work, the structural changes of SmFe 3 (PuNi 3 -type structure) during heating in high hydrogen pressures are reported

Hydrogen in metals

International Nuclear Information System (INIS)

1986-01-01

The report briefly describes the results of the single projects promoted by the German Council of Research (DFG). The subjects deal with diffusion, effusion, permeation and solubility of hydrogen in metals. They are interesting for many disciplines: metallurgy, physical metallurgy, metal physics, materials testing, welding engineering, chemistry, nuclear physics and solid-state physics. The research projects deal with the following interrelated subjects: solubility of H 2 in steel and effects on embrittlement, influence of H 2 on the fatigue strength of steel as well as the effect of H 2 on welded joints. The studies in solid-state research can be divided into methodological and physico-chemical studies. The methodological studies mainly comprise investigations on the analytical determination of H 2 by means of nuclear-physical reactions (e.g. the 15 N method) and the application of the Moessbauer spectroscopy. Physico-chemical problems are mainly dealt with in studies on interfacial reactions in connection with the absorption of hydrogen and on the diffusion of H 2 in different alloy systems. The properties of materials used for hydrogen storage were the subject of several research projects. 20 contributions were separately recorded for the data bank 'Energy'. (MM) [de

Photon compression in cylinders

International Nuclear Information System (INIS)

Ensley, D.L.

1977-01-01

It has been shown theoretically that intense microwave radiation is absorbed non-classically by a newly enunciated mechanism when interacting with hydrogen plasma. Fields > 1 Mg, lambda > 1 mm are within this regime. The predicted absorption, approximately P/sub rf/v/sub theta/sup e/, has not yet been experimentally confirmed. The applications of such a coupling are many. If microwave bursts approximately > 5 x 10 14 watts, 5 ns can be generated, the net generation of power from pellet fusion as well as various military applications becomes feasible. The purpose, then, for considering gas-gun photon compression is to obtain the above experimental capability by converting the gas kinetic energy directly into microwave form. Energies of >10 5 joules cm -2 and powers of >10 13 watts cm -2 are potentially available for photon interaction experiments using presently available technology. The following topics are discussed: microwave modes in a finite cylinder, injection, compression, switchout operation, and system performance parameter scaling

Thermodynamic and kinetics models of hydrogen absorption bound to phase transformations

International Nuclear Information System (INIS)

Gondor, G.; Lexcellent, Ch.

2007-01-01

In order to design hydrogen gaseous pressure tanks, the absorption (desorption) of hydrogen has to be described and modelled. The equilibrium state can be described by the 'H 2 gas pressure - H 2 composition in the intermetallic compounds - isotherms' (PCI) curves. Several models of PCI curves already exist. At the beginning of the absorption, the hydrogen atoms and the intermetallic compounds form a solid solution (α phase). When the hydrogen concentration increases, a phase transformation appears changing the α solid solution into an hydride (β phase) (solid solution + H 2 ↔ hydride). When all the solid solution has been transformed into hydride, the absorbed hydrogen atoms are in β phase. A new thermodynamic model has been developed in order to take into account this transition phase. The equilibrium state is then given by a relation between the H 2 gas pressure and the H 2 concentration in the intermetallic compound for a fixed external temperature. Two kinetics models have been developed too; at first has been considered that the kinetics depend only of the entire concentration in the intermetallic compound and of the difference between the applied pressure and the equilibrium pressure. Then, has been considered that the hydrogen concentration changes in the metallic matrix. In this last case, for each hydrogenation process, the absorption velocity is calculated to determine the slowest local process which regulates the local evolution of the hydrogen concentration. These two models are based on the preceding thermodynamic model of the PCI curves. (O.M.)

Beam dynamics of the Neutralized Drift Compression Experiment-II (NDCX-II),a novel pulse-compressing ion accelerator

International Nuclear Information System (INIS)

Friedman, A.; Barnard, J.J.; Cohen, R.H.; Grote, D.P.; Lund, S.M.; Sharp, W.M.; Faltens, A.; Henestroza, E.; Jung, J.-Y.; Kwan, J.W.; Lee, E.P.; Leitner, M.A.; Logan, B.G.; Vay, J.-L.; Waldron, W.L.; Davidson, R.C.; Dorf, M.; Gilson, E.P.; Kaganovich, I.D.

2009-01-01

Intense beams of heavy ions are well suited for heating matter to regimes of emerging interest. A new facility, NDCX-II, will enable studies of warm dense matter at ∼1 eV and near-solid density, and of heavy-ion inertial fusion target physics relevant to electric power production. For these applications the beam must deposit its energy rapidly, before the target can expand significantly. To form such pulses, ion beams are temporally compressed in neutralizing plasma; current amplification factors of ∼50-100 are routinely obtained on the Neutralized Drift Compression Experiment (NDCX) at LBNL. In the NDCX-II physics design, an initial non-neutralized compression renders the pulse short enough that existing high-voltage pulsed power can be employed. This compression is first halted and then reversed by the beam's longitudinal space-charge field. Downstream induction cells provide acceleration and impose the head-to-tail velocity gradient that leads to the final neutralized compression onto the target. This paper describes the discrete-particle simulation models (1-D, 2-D, and 3-D) employed and the space-charge-dominated beam dynamics being realized.

The reductive decomposition of calcium sulphate I. Kinetics of the apparent solid-solid reaction

NARCIS (Netherlands)

Kamphuis, B.; Potma, A.W.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

1992-01-01

The reductive decomposition of calcium sulphate by hydrogen is used for the regeneration of calcium-based atmospheric fluidized bed combustion (AFBC) SO2 sorbents. The apparent solid¿solid reaction between CaS and CaSO4, one of the steps involved in the reaction mechanism of the reductive

Negative compressibility observed in graphene containing resonant impurities

International Nuclear Information System (INIS)

Chen, X. L.; Wang, L.; Li, W.; Wang, Y.; He, Y. H.; Wu, Z. F.; Han, Y.; Zhang, M. W.; Xiong, W.; Wang, N.

2013-01-01

We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of ±0.04 eV around the charge neutrality point were probed in e-beam-irradiated graphene capacitors. Theoretical results based on tight-binding and Lifshitz models agreed well with experimental observations of graphene containing a low concentration of resonant impurities. The interaction between resonant states and Landau levels was detected by varying the applied magnetic field. The interaction mechanisms and enhancement of the negative compressibility in disordered graphene are discussed.

Experimental studies of equation of gases state for hydrogen and deuterium

International Nuclear Information System (INIS)

Jiang Guoqiang; Lu Guangda

1992-11-01

The low order Virial coefficient and compression factors of hydrogen, deuterium and the mixtures of both materials were experimentally determined by using Burnett method at the normal temperature and the pressure of 0.5 to 40 MPa. Comparing the results obtained with the data in references, the relative error of compression factor is less than 0.2%

Anomalously deep penetration of hydrogen into niobium under action of pulse high temperature hydrogen plasma

International Nuclear Information System (INIS)

Didyk, A.Yu.

2011-01-01

The method of elastic recoil detection (ERD) has been used for the study of storage and redistribution processes of hydrogen atoms under the influence of pulse high temperature hydrogen plasma obtained using the 'Plasma Focus' PF-4 set-up in three high purity niobium foils. It was established that with an increase of number of PF-4 set-up pulses there occur spreading and transfer of implanted hydrogen atoms to large depths in three Nb-foils which are significantly larger than the projected range of hydrogen ions (with the velocity ∼ 10 8 cm/s). The maximum hydrogen concentration up to 60 at. % is reached in the nearest to Ph-4 surface of the third Nb-foil at 20 impulses of the Ph-4 set-up. The observed phenomenon can be described by transfer of implanted hydrogen atoms under the action of powerful shock waves, created by pulse hydrogen plasma and (or) by accelerating hydrogen atom diffusion under the influence of compression straining wave at the front of the shock wave at redistribution of hydrogen atoms at large depths. Similar behavior was discovered and described also in series of nickel, vanadium, niobium and tantalum foils (two or three foils and more in a series) including series of foils from heterogeneous (different) materials, which were studied, too

Nippon oil's activities toward realization of hydrogen society

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Kojiro; Okazaki, Junji; Kobori, Yoshihiro; Iki, Hideshi [Nippon Oil Corporation (Japan)

2010-07-01

Nippon Oil Corporation, a major Japanese energy distributor, has been devoting extensive efforts toward the establishment of hydrogen supply systems. The Council on Competitiveness-Nippon (COCN), an advisory organization which has influence on Japanese government policy, has announced that the establishment of hydrogen infrastructure should be started in 2015. By that time, we plan to have completed the development of necessary technologies for the infrastructure. It is well recognized that the storage and transportation of hydrogen is the sticking point on the path to realization of a hydrogen economy. The scope of our research covers key technologies for hydrogen storage and transportation, including carbon fiber reinforced plastic (CFRP) tanks for compressed hydrogen gas, hydrogen storage materials, and hydrogen transportation systems which utilize organic chemical hydride (OCH). This article describes Nippon Oil's strategy for realization of the hydrogen economy. (orig.)

NRC/UBC fuelling station with intelligent compression

International Nuclear Information System (INIS)

Dada, A.; Boyd, B.; Law, L.; Semczyszyn, D.

2004-01-01

BOC Canada Ltd. will design, integrate and construct the second fueling station on the Hydrogen Highway. This station will be located at the National Research Council's Institute for Fuel Cell Innovation on the campus of the University of British Columbia. BOC's design will bring together an existing alkaline electrolyser, new compression, storage and dispensing. The station will be designed to serve fuel cell passenger vehicles using 350-bar storage. However, the flexible design concept will allow for many other user needs including the potential for servicing larger vehicles, as well as filling portable storage systems for use at satellite stations. The novel station design also offers the potential to fuel from multiple hydrogen sources. Together with NRC, this fueling station will be used to increase public, consumer and investor awareness of hydrogen technologies. Design and construction of this facility will assist in the development of industry codes and standards and familiarize authorities having jurisdiction with hydrogen fueling. The system concept offers the utmost attention to safety, novelty and flexibility. (author)

Alkali free hydrolysis of sodium borohydride for hydrogen generation under pressure

Energy Technology Data Exchange (ETDEWEB)

Ferreira, M.J.F.; Pinto, A.M.F.R. [Centro de Estudos de Fenomenos de Transporte, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto (Portugal); Gales, L. [Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto and Instituto de Ciencias Biomedicas Abel Salazar, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Fernandes, V.R.; Rangel, C.M. [Laboratorio Nacional de Energia e Geologia - LNEG, Fuel Cells and Hydrogen Unit Estrada do Paco do Lumiar 22, 1649-038 Lisboa (Portugal)

2010-09-15

The present study is related with the production of hydrogen gas (H{sub 2}), at elevated pressures and with high gravimetric storage density, to supply a PEM fuel cell on-demand. To achieve this goal, solid sodium borohydride (NaBH{sub 4}) was mixed with a proper amount of a powder reused nickel-ruthenium based catalyst (Ni-Ru based/NaBH{sub 4}: 0.2 and 0.4 g/g; {approx}150 times reused) inside the bottom of a batch reactor. Then, a stoichiometric amount of pure liquid water (H{sub 2}O/NaBH{sub 4}: 2-8 mol/mol) was added and the catalyzed NaBH{sub 4} hydrolysis evolved, in the absence of an alkali inhibitor. In this way, this research work is designated alkali free hydrolysis of NaBH{sub 4} for H{sub 2} generation. This type of hydrolysis is excellent from an environmental point of view because it does not involve strongly caustic solutions. Experiments were performed in three batch reactors with internal volumes 646, 369 and 229 cm{sup 3}, and having different bottom geometries (flat and conical shapes). The H{sub 2} generated was a function of the added water and completion was achieved with H{sub 2}O/NaBH{sub 4} = 8 mol/mol. The results show that hydrogen yields and rates increase remarkably increasing both system temperature and pressure. Reactor bottom shape influences deeply H{sub 2} generation: the conical bottom shape greatly enhances the rate and practically eliminates the reaction induction time. Our system of compressed hydrogen generation up to 1.26 MPa shows 6.3 wt% and 70 kg m{sup -3}, respectively, for gravimetric and volumetric hydrogen storage capacities (materials-only basis) and therefore is a viable hydrogen storage candidate for portable applications. (author)

Hydrogen solubility in polycrystalline - and nonocrystalline niobium

International Nuclear Information System (INIS)

Ishikawa, T.T.; Silva, J.R.G. da

1981-01-01

Hydrogen solubility in polycrystalline and monocrystalline niobium was measured in the range 400 0 C to 1000 0 C at one atmosphere hydrogen partial pressure. The experimental technique consists of saturation of the solvent metal with hydrogen, followed by quenching and analysis of the solid solution. It is presented solubility curves versus reciprocal of the absolute doping temperature, associated with their thermodynamical equation. (Author) [pt

A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

International Nuclear Information System (INIS)

Sun, Mei; Sun, Wenjie; Barlaz, Morton A.

2016-01-01

Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H 2 S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H 2 S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H 2 S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H 2 S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H 2 S by base adsorption was effective for mitigating inhibition. H 2 S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H 2 S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H 2 S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H 2 S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H 2 S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the

Solid hydrogen and deuterium. I. Ground-state energy calculated by a lowest order constrained-variation method

International Nuclear Information System (INIS)

Pettersen, G.; Oestgaard, E.

1988-01-01

The ground-state energy of solid hydrogen and deuterium is calculated by means of a modified variational lowest order constrained-variation (LOCV) method. Both fcc and hcp H 2 and D 2 are considered, and the calculations are done for five different two-body potentials. For solid H 2 we obtain theoretical results for the ground-state binding energy per particle from -74.9 K at an equilibrium particle density of 0.700 σ -3 or a molar volume of 22.3 cm 3 /mole to -91.3 K at a particle density of 0.725 σ -3 or a molar volume of 21.5 cm 3 /mole, where σ = 2.958 A. The corresponding experimental result is -92.3 K at a particle density of 0.688 σ -3 or a molar volume of 22.7 cm 3 /mole. For solid D 2 we obtain theoretical results for the ground-state binding energy per particle from -125.7 K at an equilibrium particle density of 0.830 σ -3 or a molar volume of 18.8 cm 3 /mole to -140.1 K at a particle density of 0.843 σ -3 or a molar volume of 18.5 cm 3 /mole. The corresponding experimental result is -137.9 K at a particle density of 0.797 σ -3 or a molar volume of 19.6 cm 3 /mole

Electrolytic production and dispensing of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Thomas, C.E.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

1995-09-01

The fuel cell electric vehicle (FCEV) is undoubtedly the only option that can meet both the California zero emission vehicle (ZEV) standard and the President`s goal of tripling automobile efficiency without sacrificing performance in a standard 5-passenger vehicle. The three major automobile companies are designing and developing FCEVs powered directly by hydrogen under cost-shared contracts with the Department of Energy. Once developed, these vehicles will need a reliable and inexpensive source of hydrogen. Steam reforming of natural gas would produce the least expensive hydrogen, but funding may not be sufficient initially to build both large steam reforming plants and the transportation infrastructure necessary to deliver that hydrogen to geographically scattered FCEV fleets or individual drivers. This analysis evaluates the economic feasibility of using small scale water electrolysis to provide widely dispersed but cost-effective hydrogen for early FCEV demonstrations. We estimate the cost of manufacturing a complete electrolysis system in large quantities, including compression and storage, and show that electrolytic hydrogen could be cost competitive with fully taxed gasoline, using existing residential off-peak electricity rates.

Integration of Flex Nozzle System and Electro Hydraulic Actuators to Solid Rocket Motors

Science.gov (United States)

Nayani, Kishore Nath; Bajaj, Dinesh Kumar

2017-10-01

A rocket motor assembly comprised of solid rocket motor and flex nozzle system. Integration of flex nozzle system and hydraulic actuators to the solid rocket motors are done after transportation to the required place where integration occurred. The flex nozzle system is integrated to the rocket motor in horizontal condition and the electro hydraulic actuators are assembled to the flex nozzle systems. The electro hydraulic actuators are connected to the hydraulic power pack to operate the actuators. The nozzle-motor critical interface are insulation diametrical compression, inhibition resin-28, insulation facial compression, shaft seal `O' ring compression and face seal `O' ring compression.

Preparing interesting hydrocarbons by hydrogenation, etc

Energy Technology Data Exchange (ETDEWEB)

1938-02-15

Now, it has been found that gasoline and a combustible oil are produced by destructive hydrogenation of pastes prepared from solid carbonaceous materials and mixtures of middle oils and the mud in question, by regulating the composition of the products removed as vapors in a way that they contain at least the total new heavy oil formed in the course of the destructive hydrogenation and in using as mixing agent for the new raw material the mud proceeding from the operation and middle oil, having withdrawn from this mud all or part of the solid constituents. This destructive hydrogenation is carried out in a converter where a constant level of liquid is maintained, the vapors escaping at the top of the converter and the mud being drawn off at one or more places from the column of liquid undergoing reaction.

Hydrogen alternatives for a regional upgrader

International Nuclear Information System (INIS)

Bailey, R.T.; Padamsey, R.

1991-01-01

For a proposed regional upgrader in Alberta, hydrogen will be needed to upgrade the bitumen and heavy oil to be processed by that facility. The upgrader will rely on high conversion hydrocracking which consumes 3.4 wt % hydrogen to produce a 106% volume yield of high quality synthetic crude. The costs of producing hydrogen via steam reforming of methane, partial oxidation of coal or upgrading residues, and electrolysis are compared, showing that steam reforming is the cheapest. However, an even cheaper source of hydrogen is available in the Edmonton and Fort Saskatchewan area as byproducts from petrochemical plants. An economic analysis is presented of a proposed scheme to capture, purify, compress, and transfer hydrogen from one or two such plants to a nearby regional upgrader. The two plants could supply a total of 126.6 million ft 3 /d of hydrogen at a total installed capital cost of about half of that of a steam reforming plant of equivalent size. When operating costs are added (including the cost of replacing the hydrogen, currently used as fuel at the two plants, with natural gas), the total cost of hydrogen is substantially less than the costs for a hydrogen plant within the upgrader. 3 refs., 5 figs., 4 tabs

Passive notch circuit for pulsed-off compression fields

International Nuclear Information System (INIS)

Nunnally, W.C.

1976-06-01

The operation and simulated results of a passive notch circuit used to pulse off the field in a multiturn, fusion-power system, compression coil are presented. The notch circuit permits initial plasma preparation at field zero, adiabatic compression as the field returns to its initial value, and long field decay time for plasma confinement. The major advantages and disadvantages of the notch circuit are compared with those of a standard capacitor power supply system. The major advantages are that: (1) slow-rising fields can be used for adiabatic compression, (2) solid-state switches can be used because of the inherent current and voltage waveforms, and (3) long field decay times are easier to attain than with single-turn coils

Applied hydrogen storage research and development: A perspective from the U.S. Department of Energy

International Nuclear Information System (INIS)

O’Malley, Kathleen; Ordaz, Grace; Adams, Jesse; Randolph, Katie; Ahn, Channing C.; Stetson, Ned T.

2015-01-01

Highlights: • Overview of U.S. DOE-supported hydrogen storage technology development efforts. • Physical and materials-based strategy for developing hydrogen storage systems. • Materials requirements for automotive storage systems. • Key R&D developments. - Abstract: To enable the wide-spread commercialization of hydrogen fuel cell technologies, the U.S. Department of Energy, through the Office of Energy Efficiency and Renewable Energy’s Fuel Cell Technology Office, maintains a comprehensive portfolio of R&D activities to develop advanced hydrogen storage technologies. The primary focus of the Hydrogen Storage Program is development of technologies to meet the challenging onboard storage requirements for hydrogen fuel cell electric vehicles (FCEVs) to meet vehicle performance that consumers have come to expect. Performance targets have also been established for materials handling equipment (e.g., forklifts) and low-power, portable fuel cell applications. With the imminent release of commercial FCEVs by automobile manufacturers in regional markets, a dual strategy is being pursued to (a) lower the cost and improve performance of high-pressure compressed hydrogen storage systems while (b) continuing efforts on advanced storage technologies that have potential to surpass the performance of ambient compressed hydrogen storage

Applied hydrogen storage research and development: A perspective from the U.S. Department of Energy

Energy Technology Data Exchange (ETDEWEB)

O’Malley, Kathleen [SRA International, Inc., Fairfax, VA 22033 (United States); Ordaz, Grace; Adams, Jesse; Randolph, Katie [U.S. Department of Energy, 1000 Independence Ave., SW, EE-3F, Washington, DC 20585 (United States); Ahn, Channing C. [U.S. Department of Energy, 1000 Independence Ave., SW, EE-3F, Washington, DC 20585 (United States); California Institute of Technology, Pasadena, CA 91125 (United States); Stetson, Ned T., E-mail: Ned.Stetson@ee.doe.gov [U.S. Department of Energy, 1000 Independence Ave., SW, EE-3F, Washington, DC 20585 (United States)

2015-10-05

Highlights: • Overview of U.S. DOE-supported hydrogen storage technology development efforts. • Physical and materials-based strategy for developing hydrogen storage systems. • Materials requirements for automotive storage systems. • Key R&D developments. - Abstract: To enable the wide-spread commercialization of hydrogen fuel cell technologies, the U.S. Department of Energy, through the Office of Energy Efficiency and Renewable Energy’s Fuel Cell Technology Office, maintains a comprehensive portfolio of R&D activities to develop advanced hydrogen storage technologies. The primary focus of the Hydrogen Storage Program is development of technologies to meet the challenging onboard storage requirements for hydrogen fuel cell electric vehicles (FCEVs) to meet vehicle performance that consumers have come to expect. Performance targets have also been established for materials handling equipment (e.g., forklifts) and low-power, portable fuel cell applications. With the imminent release of commercial FCEVs by automobile manufacturers in regional markets, a dual strategy is being pursued to (a) lower the cost and improve performance of high-pressure compressed hydrogen storage systems while (b) continuing efforts on advanced storage technologies that have potential to surpass the performance of ambient compressed hydrogen storage.

Liquid hydrogen production via hydrogen sulfide methane reformation

Science.gov (United States)

Huang, Cunping; T-Raissi, Ali

Hydrogen sulfide (H 2S) methane (CH 4) reformation (H 2SMR) (2H 2S + CH 4 = CS 2 + 4H 2) is a potentially viable process for the removal of H 2S from sour natural gas resources or other methane containing gases. Unlike steam methane reformation that generates carbon dioxide as a by-product, H 2SMR produces carbon disulfide (CS 2), a liquid under ambient temperature and pressure-a commodity chemical that is also a feedstock for the synthesis of sulfuric acid. Pinch point analyses for H 2SMR were conducted to determine the reaction conditions necessary for no carbon lay down to occur. Calculations showed that to prevent solid carbon formation, low inlet CH 4 to H 2S ratios are needed. In this paper, we analyze H 2SMR with either a cryogenic process or a membrane separation operation for production of either liquid or gaseous hydrogen. Of the three H 2SMR hydrogen production flowsheets analyzed, direct liquid hydrogen generation has higher first and second law efficiencies of exceeding 80% and 50%, respectively.

Fullerene hydride - A potential hydrogen storage material

International Nuclear Information System (INIS)

Nai Xing Wang; Jun Ping Zhang; An Guang Yu; Yun Xu Yang; Wu Wei Wang; Rui long Sheng; Jia Zhao

2005-01-01

Hydrogen, as a clean, convenient, versatile fuel source, is considered to be an ideal energy carrier in the foreseeable future. Hydrogen storage must be solved in using of hydrogen energy. To date, much effort has been put into storage of hydrogen including physical storage via compression or liquefaction, chemical storage in hydrogen carriers, metal hydrides and gas-on-solid adsorption. But no one satisfies all of the efficiency, size, weight, cost and safety requirements for transportation or utility use. C 60 H 36 , firstly synthesized by the method of the Birch reduction, was loaded with 4.8 wt% hydrogen indicating [60]fullerene might be as a potential hydrogen storage material. If a 100% conversion of C 60 H 36 is achieved, 18 moles of H 2 gas would be liberated from each mole of fullerene hydride. Pure C 60 H 36 is very stable below 500 C under nitrogen atmosphere and it releases hydrogen accompanying by other hydrocarbons under high temperature. But C 60 H 36 can be decomposed to generate H 2 under effective catalyst. We have reported that hydrogen can be produced catalytically from C 60 H 36 by Vasks's compound (IrCl(CO)(PPh 3 ) 2 ) under mild conditions. (RhCl(CO)(PPh 3 ) 2 ) having similar structure to (IrCl(CO)(PPh 3 ) 2 ), was also examined for thermal dehydrogenation of C 60 H 36 ; but it showed low catalytic activity. To search better catalyst, palladium carbon (Pd/C) and platinum carbon (Pt/C) catalysts, which were known for catalytic hydrogenation of aromatic compounds, were tried and good results were obtained. A very big peak of hydrogen appeared at δ=5.2 ppm in 1 H NMR spectrum based on Evans'work (fig 1) at 100 C over a Pd/C catalyst for 16 hours. It is shown that hydrogen can be produced from C 60 H 36 using a catalytic amount of Pd/C. Comparing with Pd/C, Pt/C catalyst showed lower activity. The high cost and limited availability of Vaska's compounds, Pd and Pt make it advantageous to develop less expensive catalysts for our process based on

A high compression crystal growth system

International Nuclear Information System (INIS)

Nieman, H.F.; Walton, A.A.; Powell, B.M.; Dolling, G.

1980-01-01

This report describes the construction and operating procedure for a high compression crystal growth system, capable of growing single crystals from the fluid phase over the temperature range of 4.2 K to 300 K, at pressures up to 900 MPa. Some experimental results obtained with the system are given for solid β-nitrogen. (auth)

Adsorption and diffusion of hydrogen in Zircaloy-4

International Nuclear Information System (INIS)

Torres, E.; Desquines, J.; Baietto, M.C.; Coret, M.; Wehling, F.; Blat-Yrieix, M.; Ambard, A.

2015-01-01

Hydrogen in zirconium alloys is considered in many nuclear safety issues. Below 500 Celsius degrees, rather limited knowledge is available on the combined hydrogen adsorption at the sample surface and diffusion in the metal. A modeling of hydrogen gaseous charging has been established starting with a set of relevant laws and parameters derived from open literature. Simulating the hydrogen charging process requires simultaneous analysis of gaseous surface adsorption, hydrogen solid-solution diffusion and precipitation, when exceeding the material solubility limit. The modeling has been extended to reproduce the solid-gas exchange. Gaseous charging experiments have been performed at 420 C. degrees on Stress Relieved Annealed (SRA) Zircaloy-4 cladding samples to validate the model. The sample hydrogen content has been systematically measured after charging and compared to the calculated value thus providing a validation of the adsorption modeling. Complementary tests have been carried out on Recrystallized Annealed (RXA) Zircaloy-4 rods to characterize the combined diffusion and adsorption process. The hydrogen concentration distribution has been characterized using an inverse technique based on destructive analyses of the samples. This additional set of data was relevant for the validation of the hydrogen combined adsorption/diffusion modeling up to 420 C. degrees. (authors)

Safe production and application of hydrogen at Munich airport

Energy Technology Data Exchange (ETDEWEB)

Szamer, R.

2005-07-01

At Munich International Airport the world's first public filling station for liquid and gaseous hydrogen with on-site hydrogen gas production has been installed. In order to prove the safety, liability and economic feasibility of hydrogen this pilot project examined the complete sequence of hydrogen production and application: on-site production with pressurized electrolyser and steam reformer, storage and filling of gaseous and liquid hydrogen, application of hydrogen for propelling several vehicles, e.g. airport busses in day to day operation, cars, fork lifter. TUV SUD Group, one of the largest service provider for technical safety and quality, was involved in the safety evaluation of the hydrogen project from the very beginning with the following services: safety consultancy throughout all project phases, e.g. for licensing procedures, plant design and operation safety analysis of the overall plant and of subsystems (electrolyser, filling stations, storage tanks, control systems etc.) safety assessment and acceptance testing of CH2 busses, CH2 fork lifter and LH2 passenger cars inspections and tests The challenges of this complex project relating to safety will be presented in the lecture, e.g. identification of potential hazards, safety requirements for the design and operation of the hydrogen plant as wells as for the various applications. Project description The hydrogen plant (cf. Figure 1) comprises two supply paths, one for compressed gaseous hydrogen (CH2) and one for cryogenic liquid hydrogen. Gaseous hydrogen is produced via high-pressure electrolysis at an operating pressure of 3 MPa (30 bar) and/or steam reforming process. The hydrogen will be led into a compressor, compressed to 35 MPa (350 bar) and stored in high pressure cylinders with a total geometrical storage volume of 10 m. The cylinders supply the high-pressure filling stations which refuels the 3 hydrogen buses and the fork lifter. Liquid hydrogen (LH2) is delivered in tank trucks and

Physicochemical properties of direct compression tablets with spray dried and ball milled solid dispersions of tadalafil in PVP-VA.

Science.gov (United States)

Wlodarski, K; Tajber, L; Sawicki, W

2016-12-01

The aim of this research was to develop immediate release tablets comprising solid dispersion (IRSDTs) of tadalafil (Td) in a vinylpyrrolidone and vinyl acetate block copolymer (PVP-VA), characterized by improved dissolution profiles. The solid dispersion of Td in PVP-VA (Td/PVP-VA) in a weight ratio of 1:1 (w/w) was prepared using two different processes i.e. spray drying and ball milling. While the former process has been well established in the formulation of IRSDTs the latter has not been exploited in these systems yet. Regardless of the preparation method, both Td/PVP-VA solid dispersions were amorphous as confirmed by PXRD, DSC and FTIR. However, different morphology of particles (SEM) resulted in differences in water apparent solubility and disk intrinsic dissolution rate (DIDR). Both solid dispersions and crystalline Td were successfully made into directly compressible tablets at three doses of Td, i.e. 2.5mg, 10mgand20mg, yielding nine different formulations (D 1 -D 9 ). Each of the lots met the requirements set by Ph.Eur. and was evaluated with respect to appearance, diameter, thickness, mass, hardness, friability, disintegration time and content of Td. IRSDTs performed as supersaturable formulations and had significantly improved water dissolution profiles in comparison with equivalent tablets containing crystalline Td and the marketed formulations. Tablets with both spray dried and ball milled Td/PVP-VA revealed the greatest improvement in dissolution depending on the investigated doses, i.e. 2.5mgand20mg, respectively. Also, dissolution of Td from Td/PVP-VA delivered in different forms occurred in the following order: powders>tablets>capsules. Copyright © 2016 Elsevier B.V. All rights reserved.

Development Of A Centrifugal Hydrogen Pipeline Gas Compressor

Energy Technology Data Exchange (ETDEWEB)

Di Bella, Francis A. [Concepts NREC, White River Junction, VY (United States)

2015-04-16

Concepts NREC (CN) has completed a Department of Energy (DOE) sponsored project to analyze, design, and fabricate a pipeline capacity hydrogen compressor. The pipeline compressor is a critical component in the DOE strategy to provide sufficient quantities of hydrogen to support the expected shift in transportation fuels from liquid and natural gas to hydrogen. The hydrogen would be generated by renewable energy (solar, wind, and perhaps even tidal or ocean), and would be electrolyzed from water. The hydrogen would then be transported to the population centers in the U.S., where fuel-cell vehicles are expected to become popular and necessary to relieve dependency on fossil fuels. The specifications for the required pipeline hydrogen compressor indicates a need for a small package that is efficient, less costly, and more reliable than what is available in the form of a multi-cylinder, reciprocating (positive displacement) compressor for compressing hydrogen in the gas industry.

Comparison of ring compression testing to three point bend testing for unirradiated ZIRLO cladding

Energy Technology Data Exchange (ETDEWEB)

None, None

2015-04-01

Safe shipment and storage of nuclear reactor discharged fuel requires an understanding of how the fuel may perform under the various conditions that can be encountered. One specific focus of concern is performance during a shipment drop accident. Tests at Savannah River National Laboratory (SRNL) are being performed to characterize the properties of fuel clad relative to a mechanical accident condition such as a container drop. Unirradiated ZIRLO tubing samples have been charged with a range of hydride levels to simulate actual fuel rod levels. Samples of the hydrogen charged tubes were exposed to a radial hydride growth treatment (RHGT) consisting of heating to 400°C, applying initial hoop stresses of 90 to 170 MPa with controlled cooling and producing hydride precipitates. Initial samples have been tested using both a) ring compression test (RCT) which is shown to be sensitive to radial hydride and b) three-point bend tests which are less sensitive to radial hydride effects. Hydrides are generated in Zirconium based fuel cladding as a result of coolant (water) oxidation of the clad, hydrogen release, and a portion of the released (nascent) hydrogen absorbed into the clad and eventually exceeding the hydrogen solubility limit. The orientation of the hydrides relative to the subsequent normal and accident strains has a significant impact on the failure susceptability. In this study the impacts of stress, temperature and hydrogen levels are evaluated in reference to the propensity for hydride reorientation from the circumferential to the radial orientation. In addition the effects of radial hydrides on the Quasi Ductile Brittle Transition Temperature (DBTT) were measured. The results suggest that a) the severity of the radial hydride impact is related to the hydrogen level-peak temperature combination (for example at a peak drying temperature of 400°C; 800 PPM hydrogen has less of an impact/ less radial hydride fraction than 200 PPM hydrogen for the same thermal

Oils; destructive hydrogenation

Energy Technology Data Exchange (ETDEWEB)

1928-03-01

Coals, oil-shales, or other carbonaceous solids are dissolved in or extracted by solvents at temperatures over 200/sup 0/C, and under pressure, preferably over 30 atmospheres, in presence of halogens, hydrogen halides, or compounds setting free the halogen or halide under the conditions.

Extraction products of solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

1937-11-04

A method is described for the manufacture of liquid products from pressure extracts of solid carbon-containing material by destructive hydrogenation, characterized in that the pressure extracts are hydrogenated in admixture with products of high-molecular weight formed during a previous destructive hydrogenation of another part of the same or other pressure extract and which has been collected as liquid without extensive cooling of the hot products of the reaction, which came from the reaction chamber where the previous destructive hydrogenation took place.

Quantification of protein backbone hydrogen-deuterium exchange rates by solid state NMR spectroscopy

International Nuclear Information System (INIS)

Lopez del Amo, Juan-Miguel; Fink, Uwe; Reif, Bernd

2010-01-01

We present the quantification of backbone amide hydrogen-deuterium exchange rates (HDX) for immobilized proteins. The experiments make use of the deuterium isotope effect on the amide nitrogen chemical shift, as well as on proton dilution by deuteration. We find that backbone amides in the microcrystalline α-spectrin SH3 domain exchange rather slowly with the solvent (with exchange rates negligible within the individual 15 N-T 1 timescales). We observed chemical exchange for 6 residues with HDX exchange rates in the range from 0.2 to 5 s -1 . Backbone amide 15 N longitudinal relaxation times that we determined previously are not significantly affected for most residues, yielding no systematic artifacts upon quantification of backbone dynamics (Chevelkov et al. 2008b). Significant exchange was observed for the backbone amides of R21, S36 and K60, as well as for the sidechain amides of N38, N35 and for W41ε. These residues could not be fit in our previous motional analysis, demonstrating that amide proton chemical exchange needs to be considered in the analysis of protein dynamics in the solid-state, in case D 2 O is employed as a solvent for sample preparation. Due to the intrinsically long 15 N relaxation times in the solid-state, the approach proposed here can expand the range of accessible HDX rates in the intermediate regime that is not accessible so far with exchange quench and MEXICO type experiments.

DNABIT Compress - Genome compression algorithm.

Science.gov (United States)

Rajarajeswari, Pothuraju; Apparao, Allam

2011-01-22

Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, "DNABIT Compress" for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that "DNABIT Compress" algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases.

Containment hydrogen removal system for a nuclear power plant

International Nuclear Information System (INIS)

Callaghan, V.M.; Flynn, E.P.; Pokora, B.M.

1984-01-01

A hydrogen removal system (10) separates hydrogen from the containment atmosphere of a nuclear power plant using a hydrogen permeable membrane separator (30). Water vapor is removed by condenser (14) from a gas stream withdrawn from the containment atmosphere. The gas stream is then compressed by compressor (24) and cooled (28,34) to the operating temperature of the hydrogen permeable membrane separator (30). The separator (30) separates the gas stream into a first stream, rich in hydrogen permeate, and a second stream that is hydrogen depleted. The separated hydrogen is passed through a charcoal adsorber (48) to adsorb radioactive particles that have passed through the hydrogen permeable membrane (44). The hydrogen is then flared in gas burner (52) with atmospheric air and the combustion products vented to the plant vent. The hydrogen depleted stream is returned to containment through a regenerative heat exchanger (28) and expander (60). Energy is extracted from the expander (60) to drive the compressor (24) thereby reducing the energy input necessary to drive the compressor (24) and thus reducing the hydrogen removal system (10) power requirements

Large deformation behavior of fat crystal networks

NARCIS (Netherlands)

Kloek, W.; Vliet, van T.; Walstra, P.

2005-01-01

Compression and wire-cutting experiments on dispersions of fully hydrogenated palm oil in sunflower oil with varying fraction solid fat were carried out to establish which parameters are important for the large deformation behavior of fat crystal networks. Compression experiments showed that the

Compressive characteristics of closed-cell aluminum foams with different percentages of Er element

Directory of Open Access Journals (Sweden)

Wei-min Zhao

2016-01-01

Full Text Available In the present study, closed-cell aluminum foams with different percentages of erbium (Er element were successfully prepared. The distribution and existence form of erbium (Er element and its effect on the compressive properties of the foams were investigated. Results show that Er uniformly distributes in the cell walls in the forms of Al3Er intermetallic compound and Al-Er solid solutions. Compared with commercially pure aluminum foam, Er-containing foams possess higher micro-hardness, compressive strength and energy absorption capacity due to solid solution strengthening and second phase strengthening effects. Additionally, the amount of Er element should be controlled in the range of 0.10wt.%-0.50wt.% in order to obtain a good combination of compressive strength and energy absorption properties.

Microstructure of Semi-Solid Billets Produced by Electromagnetic Stirring and Behavior of Primary Particles during the Indirect Forming Process

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Chul Kyu Jin

2018-04-01

Full Text Available An A356 alloy semi-solid billet was fabricated using electromagnetic stirring. After inserting the semi-solid billet into an indirect die, a thin plate of 1.2 mm thickness was fabricated by applying compression. The microstructure of the semi-solid billets fabricated in various stirring conditions (solid fraction and stirring force were analyzed. The deformation and behavior of the primary α-Al particles were analyzed for various parameters (solid fraction, die friction, compression rate, and compression pressure. In the stirred billets, a globular structure was dominant, while a dendrite structure was dominant in the unstirred billets. As the solid fraction decreased and the stirring current increased, the equivalent diameter and roundness of the primary α-Al particles decreased. The primary α-Al particle sizes were reduced as the compressing velocity increased, while a greater number of particles could move as the compressing pressure increased. As the path over which the motion occurred became smoother, the fluidity of the particles improved. Under compression, bonded primary α-Al particles became separated into individual particles again, as the bonds were broken. As wearing caused by friction and collisions between the particles during this motion occurred, the particle sizes were reduced, and the particle shapes become increasingly spheroid.

Making the case for direct hydrogen storage in fuel cell vehicles

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James, B.D.; Thomas, C.E.; Baum, G.N.; Lomas, F.D. Jr.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

1997-12-31

Three obstacles to the introduction of direct hydrogen fuel cell vehicles are often states: (1) inadequate onboard hydrogen storage leading to limited vehicle range; (2) lack of an hydrogen infrastructure, and (3) cost of the entire fuel cell system. This paper will address the first point with analysis of the problem/proposed solutions for the remaining two obstacles addressed in other papers. Results of a recent study conducted by Directed Technologies Inc. will be briefly presented. The study, as part of Ford Motor Company/DOE PEM Fuel Cell Program, examines multiple pure hydrogen onboard storage systems on the basis of weight, volume, cost, and complexity. Compressed gas, liquid, carbon adsorption, and metal hydride storage are all examined with compressed hydrogen storage at 5,000 psia being judged the lowest-risk, highest benefit, near-term option. These results are combined with recent fuel cell vehicle drive cycle simulations to estimate the onboard hydrogen storage requirement for full vehicle range (380 miles on the combined Federal driving schedule). The results indicate that a PNGV-like vehicle using powertrain weights and performance realistically available by the 2004 PNGV target data can achieve approximate fuel economy equivalent to 100 mpg on gasoline (100 mpg{sub eq}) and requires storage of approximately 3.6 kg hydrogen for full vehicle storage quantity allows 5,000 psia onboard storage without altering the vehicle exterior lines or appreciably encroaching on the passenger or trunk compartments.