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Sample records for ce entrained fuel process

  1. Reaction kinetics of solid fuels during entrained flow gasification

    Energy Technology Data Exchange (ETDEWEB)

    Tremel, Alexander

    2012-10-24

    Despite the application of entrained flow gasification on larger scales, the reaction rates in the hot conversion zone are almost unknown. But the knowledge of the rates of the gasification reactions at high temperature and high pressure is crucial for the detailed design and optimisation of these gasifiers. This dissertation provides measurements of fuel conversion under operation conditions relevant to industrial gasifiers and aims at the transfer of the data to larger scale applications. A novel pilot-scale research reactor is developed that enables the study of gasification reactions at high temperature, high pressure and under entrained flow conditions. The Pressurised High Temperature Entrained Flow Reactor (PiTER) is operated at up to 1600 C and 4.0 MPa in pyrolysis and gasification experiments. The data set is extended by measurements in an atmospheric entrained flow reactor and a pressurised wire mesh reactor. Devolatilisation and gasification behaviour of a wide range of fuels is analysed including anthracite, bituminous coal, lignite, biocoal (from hydrothermal carbonisation), and biomass; however, Rhenish lignite is used in most of the experiments. The pyrolysis data enable the validation of a simple first order reaction model that describes the influence of pressure, temperature, and residence time on volatile yield. Char samples collected from the three reactors are analysed using laboratory procedures and bench-scale setups. Specific char surface area is measured by CO{sub 2} adsorption at 273 K, and is found to be significantly influenced by char conversion, reaction temperature, and devolatilisation pressure. The surface data are described by an extension of the Random Pore Model. Intrinsic char reactivity is measured in a pressurised thermogravimetric analyser and the influence of reactant partial pressure and temperature on the char-CO{sub 2} and char-H{sub 2}O reaction is studied. The intrinsic reaction rate is described by nth order and

  2. Fabrication of CeO2 by sol-gel process based on microfluidic technology as an analog preparation of ceramic nuclear fuel microspheres

    CERN Document Server

    Ye, Bin; Li, Jiaolong; Zhao, Zichen; Chang, Zhenqi; Serra, Christophe A

    2012-01-01

    Microfluidics integrated with sol-gel processes is introduced in preparing monodispersed MOX nuclear fuel microspheres using nonactive cerium as a surrogate for uranium or plutonium. The detailed information about microfluidic devices and sol-gel processes are provided. The effects of viscosity and flow rate of continuous and dispersed phase on size and size distribution of CeO2 microspheres have been investigated. A comprehensive characterization of the CeO2 microspheres has been conducted, including XRD pattern, SEM, density, size and size distribution. The size of prepared monodisperse particles can be controlled precisely in range of 10{\\mu}m to 1000{\\mu}m and the particle CV is below 3%.

  3. Entrainment process of carbon dioxide in the atmospheric boundary layer

    NARCIS (Netherlands)

    Vilà-Guerau de Arellano, J.; Gioli, B.; Miglietta, F.; Jonker, H.J.J.; Klein Baltink, H.; Hutjes, R.W.A.; Holtslag, A.A.M.

    2004-01-01

    Aircraft and surface measurements of turbulent thermodynamic variables and carbon dioxide (CO2) were taken above a grassland in a convective atmospheric boundary layer. The observations were analyzed to assess the importance of the entrainment process for the distribution and evolution of carbon dio

  4. Fluidized-Solid-Fuel Injection Process

    Science.gov (United States)

    Taylor, William

    1992-01-01

    Report proposes development of rocket engines burning small grains of solid fuel entrained in gas streams. Main technical discussion in report divided into three parts: established fluidization technology; variety of rockets and rocket engines used by nations around the world; and rocket-engine equation. Discusses significance of specific impulse and ratio between initial and final masses of rocket. Concludes by stating three important reasons to proceed with new development: proposed engines safer; fluidized-solid-fuel injection process increases variety of solid-fuel formulations used; and development of fluidized-solid-fuel injection process provides base of engineering knowledge.

  5. Entrainment and deposition modeling of liquid films with applications for BWR fuel rod dryout

    Science.gov (United States)

    Ratnayake, Ruwan Kumara

    While best estimate computer codes provide the licensing basis for nuclear power facilities, they also serve as analytical tools in overall plant and component design procedures. An ideal best estimate code would comprise of universally applicable mechanistic models for all its components. However, due to the limited understanding in these specific areas, many of the models and correlations used in these codes reflect high levels of empiricism. As a result, the use of such models is strictly limited to the range of parameters within which the experiments have been conducted. Disagreements between best estimate code predictions and experimental results are often explained by the mechanistic inadequacies of embedded models. Significant mismatches between calculated and experimental critical power values are common observations in the analyses of Boiling Water Reactors (BWR). Based on experimental observations and calculations, these mismatches are attributed to the additional entrainment and deposition caused by spacer grids in BWR fuel assemblies. In COBRA-TF (Coolant Boiling in Rod Arrays-Two Fluid); a state of the art industrial best estimate code, these disagreements are hypothesized to occur due the absence of an appropriate spacer grid model. In this thesis, development of a suitably detailed spacer grid model and integrating it to COBRA-TF is documented. The new spacer grid model is highly mechanistic so that the applicability of it is not seriously affected by geometric variations in different spacer grid designs. COBRA-TF (original version) simulations performed on single tube tests and BWR rod bundles with spacer grids showed that single tube predictions were more accurate than those of the rod bundles. This observation is understood to arise from the non-availability of a suitable spacer grid model in COBRA-TF. Air water entrainment experiments were conducted in a test section simulating two adjacent BWR sub channels to visualize the flow behavior at

  6. Research on the pyrolysis of hardwood in an entrained bed process development unit

    Energy Technology Data Exchange (ETDEWEB)

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O' Neil, D.J. (Georgia Inst. of Tech., Atlanta, GA (United States). Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  7. Fabrication and characterization of CeO{sub 2} pellets for simulation of nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    García-Ostos, C.; Rodríguez-Ortiz, J.A. [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain); Arévalo, C., E-mail: carevalo@us.es [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain); Cobos, J. [CIEMAT, Avenida Complutense, 40, Madrid (Spain); Gotor, F.J. [Materials Science Institute of Seville (CSIC-US), Av. Américo Vespucio, 49, 41092 Seville (Spain); Torres, Y. [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain)

    2016-03-15

    Highlights: • CeO{sub 2} is presented as a surrogate material for UO{sub 2} to study nuclear fuel. • Powder-metallurgy methods are applied to fabricate CeO{sub 2} pellets with controlled porosity. • An optimization of the fabrication parameters is established. • Microstructural and tribo-mechanical characterizations are performed. • Properties are compared to those of the nuclear fuel. - Abstract: Cerium Oxide, CeO{sub 2}, has been shown as a surrogate material to understand irradiated Mixed Oxide (MOX) based matrix fuel for nuclear power plants due to its similar structure, chemical and mechanical properties. In this work, CeO{sub 2} pellets with controlled porosity have been developed through conventional powder-metallurgy process. Influence of the main processing parameters (binder content, compaction pressure, sintering temperature and sintering time) on porosity and volumetric contraction values has been studied. Microstructure and physical properties of sintered compacts have also been characterized through several techniques. Mechanical properties such as dynamic Young's modulus, hardness and fracture toughness have been determined and connected to powder-metallurgy parameters. Simulation of nuclear fuel after reactor utilization with radial gradient porosity is proposed.

  8. Bubble size distribution in surface wave breaking entraining process

    Institute of Scientific and Technical Information of China (English)

    HAN; Lei; YUAN; YeLi

    2007-01-01

    From the similarity theorem,an expression of bubble population is derived as a function of the air entrainment rate,the turbulent kinetic energy (TKE) spectrum density and the surface tension.The bubble size spectrum that we obtain has a dependence of a-2.5+nd on the bubble radius,in which nd is positive and dependent on the form of TKE spectrum within the viscous dissipation range.To relate the bubble population with wave parameters,an expression about the air entrainment rate is deduced by introducing two statistical relations to wave breaking.The bubble population vertical distribution is also derived,based on two assumptions from two typical observation results.

  9. Fuels Processing Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Fuels Processing Laboratory in Morgantown, WV, provides researchers with the equipment they need to thoroughly explore the catalytic issues associated with...

  10. Diesel/biodiesel soot oxidation with CeO{sub 2} and CeO{sub 2}-ZrO{sub 2}- modified cordierites: a facile way of accounting for their catalytic ability in fuel combustion processes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo F.; Oliveira, Edimar de; Sousa Filho, Paulo C. de; Neri, Claudio R.; Serra, Osvaldo A., E-mail: crneri@usp.b [Universidade de Sao Paulo (DQ/FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica

    2011-07-01

    CeO{sub 2} and mixed CeO{sub 2}-ZrO{sub 2} nanopowders were synthesized and efficiently deposited onto cordierite substrates, with the evaluation of their morphologic and structural properties through XRD, SEM, and FTIR. The modified substrates were employed as outer heterogeneous catalysts for reducing the soot originated from the diesel and diesel/biodiesel blends incomplete combustion. Their activity was evaluated in a diesel stationary motor, and a comparative analysis of the soot emission was carried out through diffuse reflectance spectroscopy. The analyses have shown that the catalyst-impregnated cordierite samples are very efficient for soot oxidation, being capable of reducing the soot emission in more than 60%. (author)

  11. Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter; Frandsen, Flemming

    2011-01-01

    Co-combustion of a bituminous coal and a solid recovered fuel (SRF) was carried out in an entrained flow reactor, and the influence of additives such as NaCl, PVC, ammonium sulphate, and kaolinite on co-combustion was investigated. The co-combustion experiments were carried out with SRF shares of 7...... corrosion potential during co-combustion of coal and SRF, except for the experiments with NaCl or PVC addition....

  12. Estuarine circulation-driven entrainment of oceanic nutrients fuels coastal phytoplankton in an open coastal system in Japan

    Science.gov (United States)

    Watanabe, Kenta; Kasai, Akihide; Fukuzaki, Koji; Ueno, Masahiro; Yamashita, Yoh

    2017-01-01

    We investigated interactions among seasonal fluctuations in phytoplankton biomass, riverine nutrient flux, and the fluxes of nutrients entrained by estuarine circulation in Tango Bay, Japan, to determine the influence of freshwater inflows to an open bay on coastal phytoplankton productivity. The riverine nutrient flux was strongly regulated by river discharge. Estuarine circulation was driven by river discharge, with high fluxes of nutrients (mean nitrate + nitrite flux: 5.3 ± 3.5 Mg [mega grams]-N day-1) between winter and early spring, enhanced by nutrient supply to the surface water via vertical mixing. In contrast, low-nutrient seawater was delivered to the bay between late spring and summer (1.0 ± 0.8 Mg-N day-1). Seasonal fluctuations in phytoplankton biomass were affected by the entrained fluxes of oceanic nutrients and variation in the euphotic zone depth, and to a lesser degree by the riverine nutrient flux. Bioassays and stoichiometric analyses indicated that phytoplankton growth was limited by nitrogen and/or phosphorus. Both the entrainment of oceanic nutrients and the euphotic zone depth affected the duration and magnitude of blooms. Our findings show that, unlike semi-enclosed bays, seasonal variations in coastal phytoplankton in an open coastal system are primarily fueled by the entrainment of oceanic nutrients and are influenced by both freshwater inflow and coastal conditions (e.g. vertical mixing and wind events).

  13. A comparison of the turbulent entrainment process in line plumes and wall plumes

    Science.gov (United States)

    Parker, David; Burridge, Henry; Partridge, Jamie; Linden, Paul

    2016-11-01

    Flows driven by sources of buoyancy appear in a large number of geophysical and industrial applications. The process of turbulent entrainment in these flows is key to understanding how they evolve and how one might model them. It has been observed that the entrainment is reduced when a line source of buoyancy is positioned immediately adjacent to a wall. To gain insight into the effect of the wall on the entrainment process we perform simultaneous PIV and LIF on both line plumes, in the absence of any boundary, and when the source is adjacent to a vertical boundary forming a wall plume. The experiments are designed to isolate the effect of the wall by using the same experimental setup and parameters for both flows with the addition of the wall and half the buoyancy flux used in the wall plume case. Of particular interest is the effect the large scale eddies, forming at the edge of the plume and engulfing ambient fluid, have on the entrainment process. By using velocity statistics in a coordinate system based on the instantaneous scalar edge of the plume, a technique we have recently used to analyse similar effects in an axisymmetric plume, the significance of this large scale engulfment will be quantified.

  14. Studies on Y{sub 2}SiO{sub 5}:Ce phosphors prepared by gel combustion using new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muresan, L.E., E-mail: laura_muresan2003@yahoo.com [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Oprea, B.F.; Cadis, A.I.; Perhaita, I. [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Ponta, O. [Faculty of Physics, Babeş Bolyai University, 400084 Cluj-Napoca (Romania)

    2014-12-05

    Highlights: • Y{sub 2}SiO{sub 5}:Ce was prepared by combustion using aspartic or glutamic acid as fuels. • Combustion process occurs differently depending on the fuels amount. • Single phase X2-Y{sub 2}SiO{sub 5} phosphors were obtained in fuel rich conditions. • PL measurements indicate that aspartic acid is a better fuel than glutamic. • Optimal preparative conditions were established for synthesis of Y{sub 2}SiO{sub 5}:Ce. - Abstract: Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by combustion, using yttrium–cerium nitrate as oxidizer, aspartic or glutamic acid as fuel and TEOS as source of silicon. In this study, aspartic and glutamic acid are used for the first time for the synthesis of Y{sub 2}SiO{sub 5}:Ce phosphors. The fuels molar amount was varied from 0.5 mol to 1.5 mol in order to reveal the thermal behavior of intermediary products (gels and ashes) same as the structural and luminescent characteristics of final products (phosphors). According to thermal analysis correlated with FTIR and XPS investigations, the combustion process occurs differently depending on the fuel amount; unreacted nitrate compounds have been identified in fuel lean conditions and carbonate based compounds along with organic residue in rich fuel conditions. The conversion to well crystallized silicates was revealed by changes of FTIR vibration bands and confirmed by XRD measurements. Based on luminescent spectra, aspartic acid is a better fuel than glutamic acid. A positive effect on the luminescence have been observed for samples fired in air due to complete remove of organic residue. The best luminescence was obtained for combustions with 0.75 mol aspartic acid and 1.25 mol glutamic respectively, fired at 1400 °C for 4 h in air atmosphere.

  15. Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Preteatment and Immobilization Processes

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, Darsh T.; Nikolov, Alex

    2005-06-01

    The objectives of this research effort are to develop a fundamental understanding of the physico-chemical mechanisms that produce foaming and air entrainment in the DOE High Level (HLW) and Low Activity (LAW) radioactive waste separation and immobilization processes, and to develop and test advanced antifoam/defoaming/rheology modifier agents. Antifoams/rheology modifiers developed from this research will be tested using non-radioactive simulants of the radioactive wastes obtained from Hanford and the Savannah River Site (SRS).

  16. Simultaneous design of ionic liquid entrainers and energy efficient azeotropic separation processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; Christian, Brianna; White, John;

    2012-01-01

    A methodology and tool set for the simultaneous design of ionic liquid entrainers and azeotropic separation processes is presented. By adjusting the cation, anion, and alkyl chain length on the cation, the properties of the ionic liquid can be adjusted to design an entrainer for a given azeotropic...... mixture. Several group contribution property models available in literature have been used along with a newly developed group contribution solubility parameter model and UNIFAC model for ionic liquids (UNIFAC-IL). For a given azeotropic mixture, an ionic liquid is designed using a computer-aided molecular...... material and energy requirements when compared to an ionic liquid known to experimentally break a given azeotrope but not designed using CAMD methods. The acetone–methanol and ethanol–water azeotropes are provided as examples....

  17. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO{sub 2} catalysts for biogas oxidative steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Antonio, E-mail: antonio.vita@itae.cnr.it; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-08-01

    A series of nanosized Ni/CeO{sub 2} catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N{sub 2}-physisorption, CO-chemisorption, Temperature Programmed Reduction (H{sub 2}-TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO{sub 2} nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO{sub 2} (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process.

  18. Final Report - "Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Pretreatment and Immobilization Processes"

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, Darsh T.

    2007-10-09

    The Savannah River Site (SRS) and Hanford site are in the process of stabilizing millions of gallons of radioactive waste slurries remaining from production of nuclear materials for the Department of Energy (DOE). The Defense Waste Processing Facility (DWPF) at SRS is currently vitrifying the waste in borosilicate glass, while the facilities at the Hanford site are in the construction phase. Both processes utilize slurry-fed joule-heated melters to vitrify the waste slurries. The DWPF has experienced difficulty during operations. The cause of the operational problems has been attributed to foaming, gas entrainment and the rheological properties of the process slurries. The rheological properties of the waste slurries limit the total solids content that can be processed by the remote equipment during the pretreatment and meter feed processes. Highly viscous material can lead to air entrainment during agitation and difficulties with pump operations. Excessive foaming in waste evaporators can cause carryover of radionuclides and non-radioactive waste to the condensate system. Experimental and theoretical investigations of the surface phenomena, suspension rheology and bubble generation of interactions that lead to foaming and air entrainment problems in the DOE High Level and Low Activity Radioactive Waste separation and immobilization processes were pursued under this project. The first major task accomplished in the grant proposal involved development of a theoretical model of the phenomenon of foaming in a three-phase gas-liquid-solid slurry system. This work was presented in a recently completed Ph.D. thesis (9). The second major task involved the investigation of the inter-particle interaction and microstructure formation in a model slurry by the batch sedimentation method. Both experiments and modeling studies were carried out. The results were presented in a recently completed Ph.D. thesis. The third task involved the use of laser confocal microscopy to study

  19. Integrated coke, asphalt and jet fuel production process and apparatus

    Science.gov (United States)

    Shang, Jer Y.

    1991-01-01

    A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

  20. Separation of ethanol and water by extractive distillation with salt and solvent as entrainer: process simulation

    Directory of Open Access Journals (Sweden)

    I. D. Gil

    2008-03-01

    Full Text Available The aim of this work is to simulate and analyze an extractive distillation process for azeotropic ethanol dehydration with ethylene glycol and calcium chloride mixture as entrainer. The work was developed with Aspen Plus® simulator version 11.1. Calculation of the activity coefficients employed to describe vapor liquid equilibrium of ethanol - water - ethylene glycol - calcium chloride system was done with the NRTL-E equation and they were validated with experimental data. The dehydration process used two columns: the main extractive column and the recovery column. The solvent to feed molar ratio S/F=0.3, molar reflux ratio RR=0.35, number of theoretical stages Ns=18, feed stage Sf=12, feed solvent stage SS=3, and feed solvent temperature TS=80 ºC, were determined to obtain a distillate with at least 99.5 % mole of ethanol. A substantial reduction in the energy consumption, compared with the conventional processes, was predicted by using ethylene glycol and calcium chloride as entrainer.

  1. Preparation, characterisation and dissolution of a CeO2 analogue for UO2 nuclear fuel

    Science.gov (United States)

    Stennett, Martin C.; Corkhill, Claire L.; Marshall, Luke A.; Hyatt, Neil C.

    2013-01-01

    The behaviour of spent nuclear fuel under geological conditions is a major issue underpinning the safety case for final disposal. This work describes the preparation and characterisation of a non-radioactive UO2 fuel analogue, CeO2, to be used to investigate nuclear fuel dissolution under realistic repository conditions as part of a developing EU research programme. The densification behaviour of several cerium dioxide powders, derived from cerium oxalate, were investigated to aid the selection of a suitable powder for fabrication of fuel analogues for powder dissolution tests. CeO2 powders prepared by calcination of cerium oxalate at 800 °C and sintering at 1700 °C gave samples with similar microstructure to UO2 fuel and SIMFUEL. The suitability of the optimised synthesis route for dissolution was tested in a dissolution experiment conducted at 90 °C in 0.01 M HNO3.

  2. Health Effects Associated with Inhalation Exposure to Diesel Emission Generated with and without CeO2 Nano Fuel Additive

    Science.gov (United States)

    Diesel exhaust (DE) exposure induces adverse cardiopulmonary effects. Addition of nano cerium (Ce) oxide additive to diesel fuel (DECe) increases fuel burning efficiency resulting in altered emission characteristics and potentially altered health effects. We hypothesized that inh...

  3. Monolithic Fuel Fabrication Process Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  4. Measurements and modeling of pulverized fuel char in an entrained flow reactor

    Science.gov (United States)

    Kebria, Mazdak

    In recent years, the combustion zone of utility boilers were modified for NOx control and this made the task of maintaining low residual carbon levels in boiler fly ash much more difficult. To predict the relationships between boiler operating conditions and residual carbon-in-ash, there is a need for improvements in determining the appropriate char reactivity to use in simulating coal-fired combustors and in relating this reactivity to unburned coal characteristics. To aid in this effort, a tubular, downward-fired, refractory-lined, laminar entrained flow reactor (EFR) was built to provide a pilot scale environment with 2 seconds residence time for studying coal combustion. Using a commercial CFD code (FLUENT), a three dimensional numerical model of coal burning in the EFR was created to evaluate common char burnout kinetic modeling approaches. EFR experimental data was obtained for operating conditions adjusted to reproduce particle Lagrangian temperature and oxygen concentration time histories typically found in coal-fired utility boilers. The radial temperature profiles were measured at different axial locations in the EFR with a suction pyrometer and thermocouples. The temperature distribution in the reactor agreed well with the simulations. A gas analyzer with a quenching probe was used to measure the oxygen distribution to similarly confirm oxygen distribution in the EFR. A semi-isokinetic particulate sampling probe was used to extract ash samples at different heights in the reactor to measure the evolution of loss on ignition (LOI). Measured LOI values were used to validate the model against predicted values. Reaction kinetics rates in the model were adjusted to bring agreement between calculated LOI and the measured values from the experimental results. The LOI predictions by kinetic-diffusion and CBK model are very similar at the late stage of char burnout. The results indicate that we can achieve sufficient accuracy for the prediction of final carbon

  5. REGSOLexpert: Entrainer Selection Tool for waste solvent recovery by batch distillation processes

    OpenAIRE

    Rodriguez-Donis, Ivonne; Gerbaud, Vincent; Baudouin, Olivier; Joulia, Xavier

    2009-01-01

    A general procedure to systematize the search of several alternatives enabling the separation of non-ideal binary mixtures such as pressure-swing distillation, azeotropic and extractive distillation is presented. The use of heterogeneous entrainers is specially highlighted.

  6. Small scale processes and entrainment in a stratocumulus marine boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D.E.; Almgren, A.S.; Bell, J.B.; Beckner, V.E.; Rendleman, C.A.

    1998-05-01

    Lack of resolution is a common problem hampering the use of large eddy simulation models for investigating boundary layer dynamics. Entrainment into the tops of marine stratus is characteristic of this problem. The use of parallel computing as a technique for resolving both boundary layer motions and the entrainment region enables the investigation of the interaction between the moist thermodynamics and turbulence in the entrainment region at very small length scales (dx = 8 m, dz = 4 m). This interaction results in heterogeneity at small scales which is important for correctly diagnosing the details of entrainment. This study presents several numerical experiments at high resolution using a generalization of a 1995 GCSS (GEWEX Cloud System Studies) model intercomparison. Subtle details of the numerical algorithm are found to cause larger differences in entrainment than choice of subgrid model. A kinetic energy budget shows that even for very high resolution, numerical dissipation is usually larger than that produced by the subgrid model. However, the structure of eddies at the inversion is determined mainly by resolution with very little dependence on numerical representation. Inversion properties are converging as resolution approaches an undulation scale. Most of the mixing is confined within 100 meters of the inversion with entraining motions having an aspect ratio of 6 to 1.

  7. Physical Properties of Mixed Conductor Solid Oxide Fuel Cell Anodes of Doped CeO2

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Lindegaard, Thomas; Hansen, Uffe Rud

    1994-01-01

    Samples of CeO2 doped with oxides such as CaO and Gd2O3 were prepared. Their conductivities and expansions onreduction were measured at 1000°C, and the thermal expansion coefficients in the range 50 to 1000°C were determined. Theionic and electronic conductivity were derived from curves of total...... for solid oxide fuel cell anodes. Not all requirements are fulfilled. Measures to compensate for this arediscussed....

  8. Role of microstructure and surface defects on the dissolution kinetics of CeO2, a UO2 fuel analogue.

    OpenAIRE

    Corkhill, C.L; Bailey, D. J.; Tocino, F.Y.; Stennett, M.C.; Miller, J. A.; Provis, J.P.; Travis, K.P.; Hyatt, N.C.

    2016-01-01

    The release of radionuclides from spent fuel in a geological disposal facility is controlled by the surface mediated dissolution of UO2 in groundwater. In this study we investigate the influence of reactive surface sites on the dissolution of a synthesised CeO2 analogue for UO2 fuel. Dissolution was performed on: CeO2 annealed at high temperature, which eliminated intrinsic surface defects (point defects and dislocations); CeO2-x annealed in inert and reducing atmospheres to induce oxygen vac...

  9. Microbial fuel cell treatment of fuel process wastewater

    Science.gov (United States)

    Borole, Abhijeet P; Tsouris, Constantino

    2013-12-03

    The present invention is directed to a method for cleansing fuel processing effluent containing carbonaceous compounds and inorganic salts, the method comprising contacting the fuel processing effluent with an anode of a microbial fuel ell, the anode containing microbes thereon which oxidatively degrade one or more of the carbonaceous compounds while producing electrical energy from the oxidative degradation, and directing the produced electrical energy to drive an electrosorption mechanism that operates to reduce the concentration of one or more inorganic salts in the fuel processing effluent, wherein the anode is in electrical communication with a cathode of the microbial fuel cell. The invention is also directed to an apparatus for practicing the method.

  10. A secondary fuel removal process: plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Min, J. Y.; Kim, Y. S. [Hanyang Univ., Seoul (Korea, Republic of); Bae, K. K.; Yang, M. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-07-01

    Plasma etching process of UO{sub 2} by using fluorine containing gas plasma is studied as a secondary fuel removal process for DUPIC (Direct Use of PWR spent fuel Into Candu) process which is taken into consideration for potential future fuel cycle in Korea. CF{sub 4}/O{sub 2} gas mixture is chosen for reactant gas and the etching rates of UO{sub 2} by the gas plasma are investigated as functions of CF{sub 4}/O{sub 2} ratio, plasma power, substrate temperature, and plasma gas pressure. It is found that the optimum CF{sub 4}/O{sub 2} ratio is around 4:1 at all temperatures up to 400 deg C and the etching rate increases with increasing r.f. power and substrate temperature. Under 150W r.f. power the etching rate reaches 1100 monolayers/min at 400 deg C, which is equivalent to about 0.5mm/min. (author).

  11. Role of Microstructure and Surface Defects on the Dissolution Kinetics of CeO2, a UO2 Fuel Analogue.

    Science.gov (United States)

    Corkhill, Claire L; Bailey, Daniel J; Tocino, Florent Y; Stennett, Martin C; Miller, James A; Provis, John L; Travis, Karl P; Hyatt, Neil C

    2016-04-27

    The release of radionuclides from spent fuel in a geological disposal facility is controlled by the surface mediated dissolution of UO2 in groundwater. In this study we investigate the influence of reactive surface sites on the dissolution of a synthesized CeO2 analogue for UO2 fuel. Dissolution was performed on the following: CeO2 annealed at high temperature, which eliminated intrinsic surface defects (point defects and dislocations); CeO2-x annealed in inert and reducing atmospheres to induce oxygen vacancy defects and on crushed CeO2 particles of different size fractions. BET surface area measurements were used as an indicator of reactive surface site concentration. Cerium stoichiometry, determined using X-ray Photoelectron Spectroscopy (XPS) and supported by X-ray Diffraction (XRD) analysis, was used to determine oxygen vacancy concentration. Upon dissolution in nitric acid medium at 90 °C, a quantifiable relationship was established between the concentration of high energy surface sites and CeO2 dissolution rate; the greater the proportion of intrinsic defects and oxygen vacancies, the higher the dissolution rate. Dissolution of oxygen vacancy-containing CeO2-x gave rise to rates that were an order of magnitude greater than for CeO2 with fewer oxygen vacancies. While enhanced solubility of Ce(3+) influenced the dissolution, it was shown that replacement of vacancy sites by oxygen significantly affected the dissolution mechanism due to changes in the lattice volume and strain upon dissolution and concurrent grain boundary decohesion. These results highlight the significant influence of defect sites and grain boundaries on the dissolution kinetics of UO2 fuel analogues and reduce uncertainty in the long term performance of spent fuel in geological disposal.

  12. Comment on "138La-138Ce-136Ce nuclear cosmochronometer of the supernova neutrino process"

    CERN Document Server

    Von Neumann-Cosel, P; Byelikov, A

    2009-01-01

    The nuclear chosmochronometer suggested by Hayakawa et al. [Phys. Rev.C 77, 065802 (2008)] based on the 138La-138Ce-136Ce abundance ratio in presolar grains would be affected by the existence of a hitherto unknown low-energy 1+ state in 138La. Results of a recent high-resolution study of the 138Ba(3He,t) reaction under kinematics selectively populating 1+ states in 138La through Gamow-Teller transitions provides strong evidence against the existence of such a hypothetical state.

  13. Dry Process Fuel Performance Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Myung Seung; Song, K. C.; Moon, J. S. and others

    2005-04-15

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase II R and D. In order to fulfil this objectives, irradiation test of DUPIC fuel was carried out in HANARO using the non-instrumented and SPND-instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase II are summarized as follows : - Performance evaluation of DUPIC fuel via irradiation test in HANARO - Post irradiation examination of irradiated fuel and performance analysis - Development of DUPIC fuel performance code (modified ELESTRES) considering material properties of DUPIC fuel - Irradiation behavior and integrity assessment under the design power envelope of DUPIC fuel - Foundamental technology development of thermal/mechanical performance evaluation using ANSYS (FEM package)

  14. Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

    Institute of Scientific and Technical Information of China (English)

    ZHI Keduan; LIU Quansheng; ZHAO Ruigang; HE Runxia; ZHANG Lifeng

    2008-01-01

    Cu-Ce-La mixed oxides were prepared by three precipitation methods (coprecipitation, homogeneous precipitation, and deposition precipitation) with variable precipitators and characterized using X-ray diffraction, BET, temperature-programmed reduction, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by coprecipitation method with NaOH as precipitator presented the highest activity and thermal stability. Copper ion substituted quadrevalent ceria entered CeO2 (111) framework was in favor of activity and thermal stability of catalyst. The crystallinity of fresh catalysts increased with the reduction process. La3+ or Ce4+ substituted copper ion entered the CeO2 framework during reduction process. The coexistence of surface copper oxide (crystalline) and pure bulk crystalline copper oxide both contributed to the high activity and thermal stability of Cu-Ce-La mixes oxide catalyst.

  15. One-Dimensional Modeling of an Entrained Coal Gasification Process Using Kinetic Parameters

    Directory of Open Access Journals (Sweden)

    Moonkyeong Hwang

    2016-02-01

    Full Text Available A one-dimensional reactor model was developed to simulate the performance of an entrained flow gasifier under various operating conditions. The model combined the plug flow reactor (PFR model with the well-stirred reactor (WSR model. Reaction kinetics was considered together with gas diffusion for the solid-phase reactions in the PFR model, while equilibrium was considered for the gas-phase reactions in the WSR model. The differential and algebraic equations of mass balance and energy balance were solved by a robust ODE solver, i.e., an semi-implicit Runge–Kutta method, and by a nonlinear algebraic solver, respectively. The computed gasifier performance was validated against experimental data from the literature. The difference in product gas concentration from the equilibrium model, and the underlying mechanisms were discussed further. The optimal condition was found after parameter studies were made for various operating conditions.

  16. Dry process fuel performance technology development

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kweon Ho; Kim, K. W.; Kim, B. K. (and others)

    2006-06-15

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase III R and D. In order to fulfil this objectives, property model development of DUPIC fuel and irradiation test was carried out in Hanaro using the instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase III are summarized as follows: Fabrication process establishment of simulated DUPIC fuel for property measurement, Property model development for the DUPIC fuel, Performance evaluation of DUPIC fuel via irradiation test in Hanaro, Post irradiation examination of irradiated fuel and performance analysis, Development of DUPIC fuel performance code (KAOS)

  17. Nanostructured Gd-CeO2 electrolyte for solid oxide fuel cell by aqueous tape casting

    Science.gov (United States)

    Akbari-Fakhrabadi, A.; Mangalaraja, R. V.; Sanhueza, Felipe A.; Avila, Ricardo E.; Ananthakumar, S.; Chan, S. H.

    2012-11-01

    Gadolinia-doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte was fabricated by aqueous-based tape casting method for solid oxide fuel cells (SOFCs). The ceramic powder prepared by combustion synthesis was used with poly acrylic acid (PAA), poly vinyl alcohol (PVA), poly ethylene glycol (PEG), Octanol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate and double distilled water as dispersant, binder, plasticizer, defoamer, surfactant and solvent respectively, to prepare stable GDC slurry. The conditions for preparing stable GDC slurries were studied and optimized by sedimentation, zeta potential and viscosity measurements. Green tapes with smooth surface, flexibility, thickness in the range of 0.35-0.4 mm and 45% relative green density were prepared. Conventional and flash sintering techniques were used and compared for densification which demonstrated the possibility of surpassing sintering at high temperatures and retarding related grain growth.

  18. Entrained flow gasification of coal/bio-oil slurries

    DEFF Research Database (Denmark)

    Feng, Ping; Lin, Weigang; Jensen, Peter Arendt;

    2016-01-01

    Coal/bio-oil slurry (CBS) is a new partial green fuel for bio-oil utilization. CBS reacts with gasification agents at high temperatures and converts into hydrogen and carbon monoxide. This paper provides a feasibility study for the gasification of CBS in an atmospheric entrained flow reactor...... for syngas production. Experiments have shown that CBS can be successfully processed and gasified in the entrained flow reactor to produce syngas with almost no tar content and low residual carbon formation. High reactor temperature and steam/carbon ratio is favourable for H2 production. At 1400 °C...

  19. Fuel quality processing study, volume 1

    Science.gov (United States)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  20. Process and apparatus for burning solid fuel

    NARCIS (Netherlands)

    Lin, W.; Van den Bleek, C.M.

    1995-01-01

    Abstract of NL 9301828 (A) Described is a process for burning solid fuel, in which nitrogen in the form of NH3 is released from said fuel, for example by gasification, said NH3 being excluded from the combustion process but being admixed, together with CO likewise released, to the gases released

  1. Fuel Conditioning Facility Electrorefiner Process Model

    Energy Technology Data Exchange (ETDEWEB)

    DeeEarl Vaden

    2005-10-01

    The Fuel Conditioning Facility at the Idaho National Laboratory processes spent nuclear fuel from the Experimental Breeder Reactor II using electro-metallurgical treatment. To process fuel without waiting for periodic sample analyses to assess process conditions, an electrorefiner process model predicts the composition of the electrorefiner inventory and effluent streams. For the chemical equilibrium portion of the model, the two common methods for solving chemical equilibrium problems, stoichiometric and non stoichiometric, were investigated. In conclusion, the stoichiometric method produced equilibrium compositions close to the measured results whereas the non stoichiometric method did not.

  2. Mathematical modeling of biomass fuels formation process.

    Science.gov (United States)

    Gaska, Krzysztof; Wandrasz, Andrzej J

    2008-01-01

    The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task.

  3. Fuel corrosion processes under waste disposal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada)

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate.

  4. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    of different fuels on syngas products was investigated at 1400 °C with steam addition. The yields of residual particulates (char and/or soot) decreased with increasing straw fraction during straw/wood co-gasification and with increasing biomass fraction (straw or wood) during biomass/coal co......, char-gas and soot-gas reactions, detailed gas-phase reactions, and mass and heat transfer. The model could reasonable predict the yields of syngas products obtained in the biomass gasification experiments. Moreover, the simulation results suggest that the soot can be completely converted and thereby......The present Ph. D. thesis describes experimental and modeling investigations on entrained flow gasification of biomass and an experimental investigation on entrained flow cogasification of biomass and coal. A review of the current knowledge of biomass entrained flow gasification is presented...

  5. Results of High-Temperature Heating Test for Irradiated U-10Zr(-5Ce with T92 Cladding Fuel

    Directory of Open Access Journals (Sweden)

    June-Hyung Kim

    2016-11-01

    Full Text Available A microstructure observation using an optical microscope, SEM and EPMA was performed for the irradiated U-10Zr and U-10Zr-5Ce fuel slugs with a T92 cladding specimen after a high-temperature heating test. Also, the measured eutectic penetration rate was compared with the value predicted by the existing eutectic penetration correlation being used for design and modeling purposes. The heating temperature and duration time for the U-10Zr/T92 specimen were 750 °C and 1 h, and those for the U-10Zr-5Ce/T92 specimen were 800 °C and 1 h. In the case of the U-10Zr/T92 specimen, the migration phenomena of U, Zr, Fe, and Cr as well as the Nd lanthanide fission product were observed at the eutectic melting region. The measured penetration rate was similar to the value predicted by the existing eutectic penetration rate correlation. In addition, when comparing with measured eutectic penetration rates for the unirradiated U-10Zr fuel slug with FMS (ferritic martensitic steel, HT9 or Gr.91 cladding specimens which had been reported in the literature, the measured eutectic penetration rate for the irradiated fuel specimen was higher than that for the unirradiated U-10Zr specimen. In the case of the U-10Zr-5Ce/T92 specimen in which there had been a gap between the fuel slug and cladding after the irradiation test, the eutectic melting region was not found because contact between the fuel slug and cladding did not take place during the heating test.

  6. SOFC system with integrated catalytic fuel processing

    Science.gov (United States)

    Finnerty, Caine; Tompsett, Geoff. A.; Kendall, Kevin; Ormerod, R. Mark

    In recent years, there has been much interest in the development of solid oxide fuel cell technology operating directly on hydrocarbon fuels. The development of a catalytic fuel processing system, which is integrated with the solid oxide fuel cell (SOFC) power source is outlined here. The catalytic device utilises a novel three-way catalytic system consisting of an in situ pre-reformer catalyst, the fuel cell anode catalyst and a platinum-based combustion catalyst. The three individual catalytic stages have been tested in a model catalytic microreactor. Both temperature-programmed and isothermal reaction techniques have been applied. Results from these experiments were used to design the demonstration SOFC unit. The apparatus used for catalytic characterisation can also perform in situ electrochemical measurements as described in previous papers [C.M. Finnerty, R.H. Cunningham, K. Kendall, R.M. Ormerod, Chem. Commun. (1998) 915-916; C.M. Finnerty, N.J. Coe, R.H. Cunningham, R.M. Ormerod, Catal. Today 46 (1998) 137-145]. This enabled the performance of the SOFC to be determined at a range of temperatures and reaction conditions, with current output of 290 mA cm -2 at 0.5 V, being recorded. Methane and butane have been evaluated as fuels. Thus, optimisation of the in situ partial oxidation pre-reforming catalyst was essential, with catalysts producing high H 2/CO ratios at reaction temperatures between 873 K and 1173 K being chosen. These included Ru and Ni/Mo-based catalysts. Hydrocarbon fuels were directly injected into the catalytic SOFC system. Microreactor measurements revealed the reaction mechanisms as the fuel was transported through the three-catalyst device. The demonstration system showed that the fuel processing could be successfully integrated with the SOFC stack.

  7. SOFC system with integrated catalytic fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Finnerty, C.; Tompsett, G.A.; Kendall, K.; Ormerod, R.M. [Birchall Centre for Inorganic Chemistry and Materials Science, Keele Univ. (United Kingdom)

    2000-03-01

    In recent years, there has been much interest in the development of solid oxide fuel cell technology operating directly on hydrocarbon fuels. The development of a catalytic fuel processing system, which is integrated with the solid oxide fuel cell (SOFC) power source is outlined here. The catalytic device utilises a novel three-way catalytic system consisting of an in situ pre-reformer catalyst, the fuel cell anode catalyst and a platinum-based combustion catalyst. The three individual catalytic stages have been tested in a model catalytic microreactor. Both temperature-programmed and isothermal reaction techniques have been applied. Results from these experiments were used to design the demonstration SOFC unit. The apparatus used for catalytic characterisation can also perform in situ electrochemical measurements as described in previous papers [C.M. Finnerty, R.H. Cunningham, K. Kendall, R.M. Ormerod, Chem. Commun. (1998) 915-916; C.M. Finnerty, N.J. Coe, R.H. Cunningham, R.M. Ormerod, Catal. Today 46 (1998) 137-145]. This enabled the performance of the SOFC to be determined at a range of temperatures and reaction conditions, with current output of 290 mA cm{sup -2} at 0.5 V, being recorded. Methane and butane have been evaluated as fuels. Thus, optimisation of the in situ partial oxidation pre-reforming catalyst was essential, with catalysts producing high H{sub 2}/CO ratios at reaction temperatures between 873 K and 1173 K being chosen. These included Ru and Ni/Mo-based catalysts. Hydrocarbon fuels were directly injected into the catalytic SOFC system. Microreactor measurements revealed the reaction mechanisms as the fuel was transported through the three-catalyst device. The demonstration system showed that the fuel processing could be successfully integrated with the SOFC stack. (orig.)

  8. A new cathode using CeO2/MWNT for hydrogen peroxide synthesis through a fuel cell

    Institute of Scientific and Technical Information of China (English)

    XU Fuyuan; SONG Tianshun; XU Yuan; CHEN Yingwen; ZHU Shemin; SHEN Shubao

    2009-01-01

    Catalyst using CeO2/MWNT (multi-walled carbon nanotube) was prepared by chemical deposition method and was applied to prepare the cathode of fuel cell for hydrogen peroxide synthesis. Effect of catalyst loading, flow rate of aqueous solution, and KOH concentration on hydrogen peroxide synthesis were investigated. Experimental results indicated that hydrogen peroxide concentration approached 275 mmol/L given 25% of CeO2/MWNT, 18 ml/h of aqueous solution, and 5 mol/L of KOH concentration. Moreover, the reaction mechanism was further discussed. The results indicated that MWNT and cerium oxide were the synergism to produce hydrogen peroxide. Increase of KOH concentration not only reduced the apparent cell resistance but also increased the open-circuit voltage.

  9. Synthesis of CeO2/fly ash cenospheres composites as novel photocatalysts by modified pyrolysis process

    Institute of Scientific and Technical Information of China (English)

    张进; 王冰; 崔皓; 李闯; 翟建平; 李琴

    2014-01-01

    A novel fly ash cenospheres (FACs)-supported CeO2 composite (CeO2/FACs) was successfully synthesized by the modi-fied pyrolysis process. The prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflection spectra (DRS) techniques. XRD results indicated that the CeO2 film coated on cenospheres was a face-centered cubic structure. SEM images confirmed that the CeO2 film was relatively com-pact. XPS results showed that Ce was present as both Ce4+and Ce3+oxidation states in CeO2 film coated on FACs substrate. The bandgap of the composite was narrower compared with the pure CeO2. The as-prepared material exhibited good photocatalytic activ-ity for the decolorization of methylene blue (MB) under visible light irradiation, and the first-order reaction rate constant (k) of 0.0028 min–1 for CeO2/FACs composite was higher than 0.0015 min–1 of pure CeO2. The fact that they floated on water meant that CeO2/FACs composites were easily recovered from water by filtration after the reaction. The recycling test revealed that the compos-ites were quite stable during the MB photocatalytic decolorization. The CeO2/FACs catalyst was therefore promising for practical use in the degradation of pollutants or water cleanup.

  10. CeO2 nanocubes-graphene oxide as durable and highly active catalyst support for proton exchange membrane fuel cell.

    Science.gov (United States)

    Lei, M; Wang, Z B; Li, J S; Tang, H L; Liu, W J; Wang, Y G

    2014-12-10

    Rapid degradation of cell performance still remains a significant challenge for proton exchange membrane fuel cell (PEMFC). In this work, we develop novel CeO2 nanocubes-graphene oxide nanocomposites as durable and highly active catalyst support for proton exchange membrane fuel cell. We show that the use of CeO2 as the radical scavenger in the catalysts remarkably improves the durability of the catalyst. The catalytic activity retention of Pt-graphene oxide-8 wt.% CeO2 nanocomposites reaches as high as 69% after 5000 CV-cycles at a high voltage range of 0.8-1.23 V, in contrast to 19% for that of the Pt-graphene oxide composites. The excellent durability of the Pt-CeO2 nanocubes-graphene oxide catalyst is attributed to the free radical scavenging activity of CeO2, which significantly slows down the chemical degradation of Nafion binder in catalytic layers, and then alleviates the decay of Pt catalysts, resulting in the excellent cycle life of Pt-CeO2-graphene oxide nanocomposite catalysts. Additionally, the performance of single cell assembled with Nafion 211 membrane and Pt-CeO2-graphene oxide catalysts with different CeO2 contents in the cathode as well as the Pt-C catalysts in the anode are also recorded and discussed in this study.

  11. Contribution of Energetically Reactive Surface Features to the Dissolution of CeO2 and ThO2 Analogues for Spent Nuclear Fuel Microstructures

    OpenAIRE

    Corkhill, C.; Myllykyla, E.; Bailey, D. J.; Thornber, S.M.; Qi, J.; Maldonado, P.; Stennett, M.C.; Hamilton, A.; Hyatt, N.C.

    2014-01-01

    In the safety case for the geological disposal of nuclear waste, the release of radioactivity from the repository is controlled by the dissolution of the spent fuel in groundwater. There remain several uncertainties associated with understanding spent fuel dissolution, including the contribution of energetically reactive surface sites to the dissolution rate. In this study, we investigate how surface features influence the dissolution rate of synthetic CeO2 and ThO2, spent nuclear fuel analog...

  12. Contribution of energetically reactive surface features to the dissolution of CeO2 and ThO2 analogues for spent nuclear fuel microstructures.

    Science.gov (United States)

    Corkhill, Claire L; Myllykylä, Emmi; Bailey, Daniel J; Thornber, Stephanie M; Qi, Jiahui; Maldonado, Pablo; Stennett, Martin C; Hamilton, Andrea; Hyatt, Neil C

    2014-08-13

    In the safety case for the geological disposal of nuclear waste, the release of radioactivity from the repository is controlled by the dissolution of the spent fuel in groundwater. There remain several uncertainties associated with understanding spent fuel dissolution, including the contribution of energetically reactive surface sites to the dissolution rate. In this study, we investigate how surface features influence the dissolution rate of synthetic CeO2 and ThO2, spent nuclear fuel analogues that approximate as closely as possible the microstructure characteristics of fuel-grade UO2 but are not sensitive to changes in oxidation state of the cation. The morphology of grain boundaries (natural features) and surface facets (specimen preparation-induced features) was investigated during dissolution. The effects of surface polishing on dissolution rate were also investigated. We show that preferential dissolution occurs at grain boundaries, resulting in grain boundary decohesion and enhanced dissolution rates. A strong crystallographic control was exerted, with high misorientation angle grain boundaries retreating more rapidly than those with low misorientation angles, which may be due to the accommodation of defects in the grain boundary structure. The data from these simplified analogue systems support the hypothesis that grain boundaries play a role in the so-called "instant release fraction" of spent fuel, and should be carefully considered, in conjunction with other chemical effects, in safety performance assessements for the geological disposal of spent fuel. Surface facets formed during the sample annealing process also exhibited a strong crystallographic control and were found to dissolve rapidly on initial contact with dissolution medium. Defects and strain induced during sample polishing caused an overestimation of the dissolution rate, by up to 3 orders of magnitude.

  13. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  14. Ni-(Ce0.8-xTix)Sm0.2O2-δ anode for low temperature solid oxide fuel cells running on dry methane fuel

    Science.gov (United States)

    Han, Bing; Zhao, Kai; Hou, Xiaoxue; Kim, Dong-Jin; Kim, Bok-Hee; Ha, Su; Norton, M. Grant; Xu, Qing; Ahn, Byung-Guk

    2017-01-01

    A titanium-doped Ce0.8Sm0.2O1.9 composite is developed as an anode component of low temperature solid oxide fuel cells running on methane fuel. Crystallographic parameters of (Ce0.8-xTix)Sm0.2O2-δ (0.00 cell consisting of Ni-(Ce0.8-xTix)Sm0.2O2-δ anode/Ce0.8Sm0.2O1.9 electrolyte/La0.6Sr0.4Co0.2Fe0.8O3-δ cathode. Catalytic properties of Ni-(Ce0.8-xTix)Sm0.2O2-δ are inspected with the electrochemical performance and performance stability of the cells in dry methane fuel. The cell with Ni-(Ce0.73Ti0.07)Sm0.2O2-δ (x = 0.07) anode displays a low polarization resistance and an optimum maximum power density (679 mW cm-2 at 600 °C). A performance stability investigation indicates that the cell exhibits a fairly low degradation rate of 3 mV h-1 during a 31 h operation in dry methane. These findings suggest the application potential of the titanium doped Ce0.8Sm0.2O1.9 for the anode of solid oxide fuel cells.

  15. Nano-engineered ZnO/CeO2 dots@CNFs for fuel cell application

    Directory of Open Access Journals (Sweden)

    Zafar Khan Ghouri

    2016-03-01

    Full Text Available Well-dispersed ZnO(xCeO2(1−x nanodots@carbon nanofibers as anode catalysts for the electrooxidation of methanol were synthesized by an easy-controlled template-free method. Their structure and morphology were characterized by X-ray diffraction (XRD, high resolution transmission electron microscopy (HR-TEM, field-emission scanning electron microscopy (FESEM equipped with rapid EDX (energy dispersive analysis of X-ray. The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by ZnO and CeO2 nanodots. The electrochemical oxidation of methanol on ZnO(xCeO2(1−x nanodots@CNFs modified glassy carbon electrode in alkaline solutions was systematically evaluated by cyclic voltammetry (CV method. A detailed investigation is made for the electrocatalytic oxidation of methanol by varying methanol concentration. The corresponding current densities of ZnO(60%CeO2(40% nanodots@CNFs and ZnO(40%CeO2(60% nanodots@CNFs were 5.3 and 16.3 mA/cm2, respectively. Moreover, negative onset potential (−50 mV vs. Ag/AgCl was observed when ZnO(40%CeO2(60% nanodots@CNFs were utilized, which is a superior value among the reported non-precious electrocatalysts. These results suggested cheap and effective nanomaterials as non-precious catalyst for DMFCs application and pave the way to further improve the performance in energy and environmental applications.

  16. Thermodynamic assessment of the LiF-CeF3-ThF4 system: Prediction of PuF3 concentration in a molten salt reactor fuel

    Science.gov (United States)

    Beneš, O.; Konings, R. J. M.

    2013-04-01

    A thermodynamic description of the LiF-CeF3-ThF4 system is made in this study using a two-sublattice model for the description of the solid solution and a quasi-chemical model based on quadruplet approximation for the liquid phase. New calorimetric experimental data of the binary LiF-CeF3, CeF3-ThF4 and ternary LiF-CeF3-ThF4 systems have been obtained in this work justifying the calculated phase diagrams. Using the obtained thermodynamic assessment the concentration of PuF3 in the LiF-ThF4 melt was estimated based on the similarities with CeF3 and the melting behaviour of the initial molten salt fast reactor fuel was discussed.

  17. Target characterization for the 130Ba(alpha,gamma)134Ce gamma-process experiment

    CERN Document Server

    Gyürky, Gy; Farkas, J; Fülöp, Zs; Somorjai, E; Szücs, T

    2011-01-01

    In order to extend the available experimental database for the astrophysical gamma-process, the cross section measurement of the 130Ba(alpha,gamma)134Ce and 130Ba(alpha,n)133Ce reactions is in progress. The measurements are carried out using thin layers of evaporated BaCO3 as target. Since the target thickness enters directly into the calculation of the cross sections, the reliability of its determination is of crucial importance. Three different methods have been used to determine the target thickness. Details of these experiments and the obtained results are presented.

  18. The impact of the new quality management system standards on the CE-marking process.

    Science.gov (United States)

    Donawa, M

    2001-01-01

    In December 2000, the new ISO 9000 quality management system series of standards was published. This represents a significant development for manufacturers marketing medical devices in Europe, who use these standards to demonstrate conformity to the European medical device Directives. This article discusses some issues related to the introduction of these standards in Europe and their use in the CE-marking process.

  19. The art of entrainment

    OpenAIRE

    Roenneberg, T.; Daan, S; Merrow, M.

    2003-01-01

    The circadian system actively synchronizes the temporal sequence of biological functions with the environment. The oscillatory behavior of the system ensures that entrainment is not passive or driven and therefore allows for great plasticity and adaptive potential. With the tools at hand, we now can concentrate on the most important circadian question: How is the complex task of entrainment achieved by anatomical, cellular, and molecular components? Understanding entrainment is equal to under...

  20. Entrainment Rate in Shallow Cumuli: Dependence on Entrained Dry Air Sources and Probability Density Functions

    Science.gov (United States)

    Lu, C.; Liu, Y.; Niu, S.; Vogelmann, A. M.

    2012-12-01

    In situ aircraft cumulus observations from the RACORO field campaign are used to estimate entrainment rate for individual clouds using a recently developed mixing fraction approach. The entrainment rate is computed based on the observed state of the cloud core and the state of the air that is laterally mixed into the cloud at its edge. The computed entrainment rate decreases when the air is entrained from increasing distance from the cloud core edge; this is because the air farther away from cloud edge is drier than the neighboring air that is within the humid shells around cumulus clouds. Probability density functions of entrainment rate are well fitted by lognormal distributions at different heights above cloud base for different dry air sources (i.e., different source distances from the cloud core edge). Such lognormal distribution functions are appropriate for inclusion into future entrainment rate parameterization in large scale models. To the authors' knowledge, this is the first time that probability density functions of entrainment rate have been obtained in shallow cumulus clouds based on in situ observations. The reason for the wide spread of entrainment rate is that the observed clouds are affected by entrainment mixing processes to different extents, which is verified by the relationships between the entrainment rate and cloud microphysics/dynamics. The entrainment rate is negatively correlated with liquid water content and cloud droplet number concentration due to the dilution and evaporation in entrainment mixing processes. The entrainment rate is positively correlated with relative dispersion (i.e., ratio of standard deviation to mean value) of liquid water content and droplet size distributions, consistent with the theoretical expectation that entrainment mixing processes are responsible for microphysics fluctuations and spectral broadening. The entrainment rate is negatively correlated with vertical velocity and dissipation rate because entrainment

  1. Ultra-Deep Adsorptive Desulfurization of Light-Irradiated Diesel Fuel over Supported TiO2-CeO2 Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jing; Wang, Xiaoxing; Chen, Yongsheng; Fujii, Mamoru; Song, Chunshan [SCUT-China; (Penn)

    2014-02-13

    This study investigates ultra-deep adsorptive desulfurization (ADS) from light-irradiated diesel fuel over supported TiO2CeO2 adsorbents. A 30-fold higher desulfurization capacity of 95 mL of fuel per gram of adsorbent (mL-F/g-sorb) or 1.143 mg of sulfur per gram of adsorbent (mg-S/g-sorb) was achieved from light-irradiated fuel over the original low-sulfur fuel containing about 15 ppm by weight (ppmw) of sulfur. The sulfur species on spent TiO2CeO2/MCM-48 adsorbent was identified by sulfur K-edge XANES as sulfones and the adsorption selectivity to different compounds tested in a model fuel decreases in the order of indole > dibenzothiophenesulfone → dibenzothiophene > 4-methyldibenzothiophene > benzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > 2-methylnaphthalene ~ fluorene > naphthalene. The results suggest that during ADS of light-irradiated fuel, the original sulfur species were chemically transformed to sulfones, resulting in the significant increase in desulfurization capacity. For different supports for TiO2–CeO2 oxides, the ADS capacity increases with a decrease in the point of zero charge (PZC) value; for silica-supported TiO2CeO2 oxides (the lowest PZC value of 2–4) with different surface areas, the ADS capacity increases monotonically with increasing surface area. The supported TiO2CeO2/MCM-48 adsorbent can be regenerated using oxidative air treatment. The present study provides an attractive new path to achieve ultraclean fuel more effectively.

  2. A Process for Evaluating Adverse Environmental Impacts by Cooling-Water System Entrainment at a California Power Plant

    Directory of Open Access Journals (Sweden)

    C.P. Ehrler

    2002-01-01

    Full Text Available A study to determine the effects of entrainment by the Diablo Canyon Power Plant (DCPP was conducted between 1996 and 1999 as required under Section 316(b of the Clean Water Act. The goal of this study was to present the U.S. Environmental Protection Agency (EPA and Central Coast Regional Water Quality Control Board (CCRWQCB with results that could be used to determine if any adverse environmental impacts (AEIs were caused by the operation of the plant’s cooling-water intake structure (CWIS. To this end we chose, under guidance of the CCRWQCB and their entrainment technical working group, a unique approach combining three different models for estimating power plant effects: fecundity hindcasting (FH, adult equivalent loss (AEL, and the empirical transport model (ETM. Comparisons of the results from these three approaches provided us a relative measure of confidence in our estimates of effects. A total of 14 target larval fish taxa were assessed as part of the DCPP 316(b. Example results are presented here for the kelp, gopher, and black-and-yellow (KGB rockfish complex and clinid kelpfish. Estimates of larval entrainment losses for KGB rockfish were in close agreement (FH is approximately equals to 550 adult females per year, AEL is approximately equals to 1,000 adults [male and female] per year, and ETM = larval mortality as high as 5% which could be interpreted as ca. 2,600 1 kg adult fish. The similar results from the three models provided confidence in the estimated effects for this group. Due to lack of life history information needed to parameterize the FH and AEL models, effects on clinid kelpfish could only be assessed using the ETM model. Results from this model plus ancillary information about local populations of adult kelpfish suggest that the CWIS might be causing an AEI in the vicinity of DCPP.

  3. Prediction and measurement of entrained flow coal gasification processes. Interim report, September 8, 1981-September 7, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Hedman, P.O.; Smoot, L.D.; Fletcher, T.H.; Smith, P.J.; Blackham, A.U.

    1984-01-31

    This volume reports interim experimental and theoretical results of the first two years of a three year study of entrained coal gasification with steam and oxygen. The gasifier facility and testing methods were revised and improved. The gasifier was also modified for high pressure operation. Six successful check-out tests at elevated pressure were performed (55, 75, 100, 130, 170, and 215 psig), and 8 successful mapping tests were performed with the Utah bituminous coal at an elevated pressure of 137.5 psig. Also, mapping tests were performed at atmospheric pressure with a Utah bituminous coal (9 tests) and with a Wyoming subbituminous coal (14 tests). The LDV system was used on the cold-flow facility to make additional nonreactive jets mixing measurements (local mean and turbulent velocity) that could be used to help validate the two-dimensional code. The previously completed two-dimensional entrained coal gasification code, PCGC-2, was evaluated through rigorous comparison with cold-flow, pulverized coal combustion, and entrained coal gasification data. Data from this laboratory were primarily used but data from other laboratories were used when available. A complete set of the data used has been compiled into a Data Book which is included as a supplemental volume of this interim report. A revised user's manual for the two-dimensional code has been prepared and is also included as a part of this interim report. Three technical papers based on the results of this study were published or prepared. 107 references, 57 figures, 35 tables.

  4. Advanced laser processing in fuel cells production

    Energy Technology Data Exchange (ETDEWEB)

    Stollhof, J.; Havrilla, D.; Schaupp, R. [TRUMPF Inc., Plymouth, MI (United States); Loeffler, K. [TRUMPF Laser und Systemtechnik TLD, Ditzingen (Germany)

    2009-07-01

    This paper discussed TRUMPF methods of joining bipolar plates to create fuel cell stacks and manufacture thin foils using diode pumped solid state lasers (DPSSLs). Beam delivery systems and processing optics were discussed. CW disk lasers were used to allow spot diameters smaller than 30 {mu}m and combined with a Galvo technology-based scanning optics systems to enable welding speeds greater than 1 m/s. A TruFiber 300 diffraction limited fiber laser was used for CW laser cutting. Short and ultra-short laser pulses were used to drill thousands of holes per second without a measurable heat-affected zone. The attributes and specifications of the 3 major TRUMPF lasers developed to manufacture fuel cells were also provided.

  5. Nanoporous silver cathode surface treated by atomic layer deposition of CeO(x) for low-temperature solid oxide fuel cells.

    Science.gov (United States)

    Neoh, Ke Chean; Han, Gwon Deok; Kim, Manjin; Kim, Jun Woo; Choi, Hyung Jong; Park, Suk Won; Shim, Joon Hyung

    2016-05-06

    We evaluated the performance of solid oxide fuel cells (SOFCs) with a 50 nm thin silver (Ag) cathode surface treated with cerium oxide (CeO(x)) by atomic layer deposition (ALD). The performances of bare and ALD-treated Ag cathodes were evaluated on gadolinia-doped ceria (GDC) electrolyte supporting cells with a platinum (Pt) anode over 300 °C-450 °C. Our work confirms that ALD CeO(x) treatment enhances cathodic performance and thermal stability of the Ag cathode. The performance difference between cells using a Ag cathode optimally treated with an ALD CeO(x) surface and a reference Pt cathode is about 50% at 450 °C in terms of fuel cell power output in our experiment. The bare Ag cathode completely agglomerated into islands during fuel cell operation at 450 °C, while the ALD CeO(x) treatment effectively protects the porosity of the cathode. We also discuss the long-term stability of ALD CeO(x)-treated Ag cathodes related to the microstructure of the layers.

  6. Co- and Ce/Co-coated ferritic stainless steel as interconnect material for Intermediate Temperature Solid Oxide Fuel Cells

    Science.gov (United States)

    Falk-Windisch, Hannes; Claquesin, Julien; Sattari, Mohammad; Svensson, Jan-Erik; Froitzheim, Jan

    2017-03-01

    Chromium species volatilization, oxide scale growth, and electrical scale resistance were studied at 650 and 750 °C for thin metallic Co- and Ce/Co-coated steels intended to be utilized as the interconnect material in Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC). Mass gain was recorded to follow oxidation kinetics, chromium evaporation was measured using the denuder technique and Area Specific Resistance (ASR) measurements were carried out on 500 h pre-exposed samples. The microstructure of thermally grown oxide scales was characterized using Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive X-Ray Analysis (EDX). The findings of this study show that a decrease in temperature not only leads to thinner oxide scales and less Cr vaporization but also to a significant change in the chemical composition of the oxide scale. Very low ASR values (below 10 mΩ cm2) were measured for both Co- and Ce/Co-coated steel at 650 and 750 °C, indicating that the observed change in the chemical composition of the Co spinel does not have any noticeable influence on the ASR. Instead it is suggested that the Cr2O3 scale is expected to be the main contributor to the ASR, even at temperatures as low as 650 °C.

  7. Nano-engineered ZnO/CeO2 dots@CNFs for fuel cell application

    OpenAIRE

    2016-01-01

    Well-dispersed ZnO(x)CeO2(1−x) nanodots@carbon nanofibers as anode catalysts for the electrooxidation of methanol were synthesized by an easy-controlled template-free method. Their structure and morphology were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FESEM) equipped with rapid EDX (energy dispersive analysis of X-ray). The appealed characterization techniques specified that the obtained m...

  8. Complex plasmochemical processing of solid fuel

    Directory of Open Access Journals (Sweden)

    Vladimir Messerle

    2012-12-01

    Full Text Available Technology of complex plasmaochemical processing of solid fuel by Ecibastuz bituminous and Turgay brown coals is presented. Thermodynamic and experimental study of the technology was fulfilled. Use of this technology allows producing of synthesis gas from organic mass of coal and valuable components (technical silicon, ferrosilicon, aluminum and silicon carbide and microelements of rare metals: uranium, molybdenum, vanadium etc. from mineral mass of coal. Produced a high-calorific synthesis gas can be used for methanol synthesis, as high-grade reducing gas instead of coke, as well as energy gas in thermal power plants.

  9. Audit of fuel processing restoration property

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    In April, 1992, due to a diminished need for reprocessed uranium, the Secretary of Energy terminated the Fuel Processing Restoration (FPR) project. The termination left management and operating (M&O) contractors at the Idaho National Engineering Laboratory (Laboratory) with over $54 million in tools, equipment and material to be retained, utilized or disposed of. The objectives of the audit were to determine whether FPR property was adequately accounted for and whether the property was properly redistributed or excessed when the FPR project was terminated.

  10. A robust NiO-Sm0.2Ce0.8O1.9 anode for direct-methane solid oxide fuel cell

    KAUST Repository

    Tian, Dong

    2015-07-02

    In order to directly use methane without a reforming process, NiO-Sm0.2Ce0.8O1.9 (NiO-SDC) nanocomposite anode are successfully synthesized via a one-pot, surfactant-assisted co-assembly approach for direct-methane solid oxide fuel cells. Both NiO with cubic phase and SDC with fluorite phase are obtained at 550 °C. Both NiO nanoparticles and SDC nanoparticles are highly monodispersed in size with nearly spherical shapes. Based on the as-synthesized NiO-SDC, two kinds of single cells with different micro/macro-porous structure are successfully fabricated. As a result, the cell performance was improved by 40%-45% with the new double-pore NiO-SDC anode relative to the cell performance with the conventional NiO-SDC anode due to a wider triple-phase-boundary (TPB) area. In addition, no significant degradation of the cell performance was observed after 60 hours, which means an increasing of long term stability. Therefore, the as-synthesized NiO-SDC nanocomposite is a promising anode for direct-methane solid oxide fuel cells.

  11. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  12. Constraints on Spontaneous Entrainment

    Directory of Open Access Journals (Sweden)

    Richardson Michael J.

    2011-12-01

    Full Text Available Past research has revealed that a person's rhythmic limb movements become spontaneously entrained to an environmental rhythm if a. visual information about the environmental rhythm is available and b. its frequency of the environmental rhythm is near that of the person's movements. Further, this research has demonstrated that if the eyes track the environmental stimulus, the spontaneous entrainment to the environmental rhythm is strengthened. Experiments were performed to investigate two hypotheses that could explain this eye-tracking enhancement of spontaneous entrainment. One hypothesis is that eye tracking allows for the pick up of important coordinative information at the turn-around points of a movement trajectory. Another hypothesis is that the limb movements entrain to the moving eyes through a neuromotor synergy linking the eyes and limb. Results of these experiments will help delineate the informational and dynamical constraints that can impact the acquisition of skilled actions.

  13. Mantle olivine xenocrysts entrained in Mesozoic basalts from the North China craton:Implication for replacement process of lithospheric mantle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hongfu; YING Jifeng; XU Ping; MA Yuguang

    2004-01-01

    Mesoxzoic(125 Ma) Fangcheng basalts from Shandong Province contain clearly zoned olivines that are rare in terrestrial samples and provide first evidence for the replacement of lithospheric mantle from high-Mg peridotites to low-Mg peridotites through peridotite-melt reaction. Zoned olivines have compostions in the core(Mg#=87.2-90.7)similar to those olivines from the mantle peridotitic xenoliths entrained in Cenozoic basalts from the North China craton and in the rim (Mg#=76.8-83.9)close to olivine phenocrysts of the host basalts (75.7-79.0).These compositional features as well as rounded crystal shapes and smaller grain sizes (300-800μm)demonstrate that these zoned olivines are mantle xenocrysts ,I.e.an important type of the replacement of lithospheric mantle.The reaction resulted in the transformation of the Paleozoic refractory (high-Mg)peridotites to the late Mesozoic fertile (low-Mg) and radiogenic isotope-enriched peridotites,leading to the loss of old lithospheric mantle.

  14. Chlorination and Dissolution Process of CeO2 in Molten Salt

    Institute of Scientific and Technical Information of China (English)

    MENG; Zhao-kai; LIN; Ru-shan; CHEN; Hui; ZHANG; Kai; JIA; Yan-hong; WANG; Chang-shui; SONG; Peng; HE; Hui

    2015-01-01

    Molten salt electrolysis is considered as a promising technology in pyrochemical process in recent years.In the pyrochemical process of oxides fuel,dissolution of the oxides is a significant issue for study.Oxides cannot be reduced,as the solubility is small in molten salt.The chlorination of oxides can improve the solubility

  15. Effect of adding urea on performance of Cu/CeO{sub 2}/yttria-stabilized zirconia anodes for solid oxide fuel cells prepared by impregnation method

    Energy Technology Data Exchange (ETDEWEB)

    Li Wenyuan [Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Lue Zhe, E-mail: lvzhe@hit.edu.c [Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Zhu Xingbao; Guan Bo; Wei Bo; Guan Chengzhi; Su Wenhui [Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150080 (China)

    2011-02-01

    Anode microstructure has a great influence on the cell performance. The addition of urea into impregnated solution has been proposed to tailor the distribution and/or morphology of Cu when fabricating the Cu-based anodes by impregnation method. While the previous reports demonstrated the single cell performance has not been improved in this route, in this paper, fuel cells with Cu/yttria-stabilized zirconia (YSZ) and Cu-CeO{sub 2}/YSZ anodes were fabricated and evaluated with improved outputs. The microstructure of Cu in anodes appeared significantly different after the addition of urea. The electronic conductivity obtained from the anodes impregnated with adding urea was twice as high as the ones without. Performance of fuel cells increases by 12% while operating on H{sub 2} at 700 {sup o}C upon adding urea. Furthermore, the performance improvement was more prominent when such method was adopted in the fabrication of Cu-CeO{sub 2}/YSZ composite anodes. Cells with Cu-CeO{sub 2}/YSZ composite anodes operating in H{sub 2} at 700 {sup o}C exhibited an increase of cell performance by 37%, from 337 to 462 mW cm{sup -2}, by simply adding urea to the impregnated solution. And the performance enhancement for such fuel cells is also as high as 28% when using CH{sub 4} as fuel.

  16. Selection of Fuel by Using Analytical Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Asilata M. Damle,

    2015-04-01

    Full Text Available Selection of fuel is a very important and critical decision one has to make. Various criteria are to be considered while selecting a fuel. Some of important criteria are Fuel Economy, Availability of fuel, Pollution from vehicle, Maintenance of the vehicle. Selection of best fuel is a complex situation. It needs a multi-criteria analysis. Earlier, the solution to the problem were found by applying classical numerical methods which took into account only technical and economic merits of the various alternatives. By applying multi-criteria tools, it is possible to obtain more realistic results. This paper gives a systematic analysis for selection of fuel by using Analytical Hierarchy Process (AHP. This is a multi-criteria decision making process. By using AHP we can select the fuel by comparing various factors in a mathematical model. This is a scientific method to find out the best fuel by making pairwise comparisons.

  17. Motion State of Fuel within Shell in Projection Acceleration Process

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2003-07-01

    Full Text Available The fuel-air explosive (FAE warheads are charged with the liquid-solid mixture fuel. The fuel is different 'om conventional solid explosives in physical and mechanical properties. The mass centre of the charged fuel changes during projecting the projectile. In this study, a method to calculate the mass centre change of the charged fuel is suggested and the  influence of this change on the projectile motion state in the projection process is discussed. The results show that in projection, the fuel mass centre varies with the projection acceleration and the deformation characteristics of the mixture fuel. The higher is the acceleration, the larger is the displacement of the mass centre. This displacement also increases with the compressibility of the fuel. It constitutes an influence on the state of motion for the whole projectile in the projection process, whose calculation approach is also proposed. The result provides a theoretical basis for the design of the FAE weapons.

  18. Development of Advanced Spent Fuel Management Process

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Chung Seok; Choi, I. K.; Kwon, S. G. (and others)

    2007-06-15

    As a part of research efforts to develop an advanced spent fuel management process, this project focused on the electrochemical reduction technology which can replace the original Li reduction technology of ANL, and we have successfully built a 20 kgHM/batch scale demonstration system. The performance tests of the system in the ACPF hot cell showed more than a 99% reduction yield of SIMFUEL, a current density of 100 mA/cm{sup 2} and a current efficiency of 80%. For an optimization of the process, the prevention of a voltage drop in an integrated cathode, a minimization of the anodic effect and an improvement of the hot cell operability by a modulation and simplization of the unit apparatuses were achieved. Basic research using a bench-scale system was also carried out by focusing on a measurement of the electrochemical reduction rate of the surrogates, an elucidation of the reaction mechanism, collecting data on the partition coefficients of the major nuclides, quantitative measurement of mass transfer rates and diffusion coefficients of oxygen and metal ions in molten salts. When compared to the PYROX process of INL, the electrochemical reduction system developed in this project has comparative advantages in its application of a flexible reaction mechanism, relatively short reaction times and increased process yields.

  19. MEDIUM PRESSURE HYDROUPGRADING PROCESS (MHUG) AND PRODUCTION OF CLEAN FUELS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The medium pressure hydroupgrading process (MHUG) unit with an 800 kt/a processing capacity of Jinzhou Petrochemical Company is used to hydroupgrade the mixture of FCC LCO fuel and straight-run diesel fuel in the presence of RN/RT series catalysts for improvement of the quality of the diesel fuel. Meanwhile, catalytic reforming feedstock is also obtained. The sulfur, nitrogen and aromatics contained in the hydroupgraded diesel fuel products can be minimized and the cetane number can be heightened. The produced clean fuels can meet the requirements of environmental protection.

  20. Insight into the structure and functional application of the Sr0.95Ce0.05CoO3-δ cathode for solid oxide fuel cells.

    Science.gov (United States)

    Yang, Wei; Zhang, Huairuo; Sun, Chunwen; Liu, Lilu; Alonso, J A; Fernández-Díaz, M T; Chen, Liquan

    2015-04-06

    A new perovskite cathode, Sr0.95Ce0.05CoO3-δ, performs well for oxygen-reduction reactions in solid oxide fuel cells (SOFCs). We gain insight into the crystal structure of Sr1-xCexCoO3-δ (x = 0.05, 0.1) and temperature-dependent structural evolution of Sr0.95Ce0.05CoO3-δ by X-ray diffraction, neutron powder diffraction, and scanning transmission electron microscopy experiments. Sr0.9Ce0.1CoO3-δ shows a perfectly cubic structure (a = a0), with a large oxygen deficiency in a single oxygen site; however, Sr0.95Ce0.05CoO3-δ exhibits a tetragonal perovskite superstructure with a double c axis, defined in the P4/mmm space group, that contains two crystallographically different cobalt positions, with distinct oxygen environments. The structural evolution of Sr0.95Ce0.05CoO3-δ at high temperatures was further studied by in situ temperature-dependent NPD experiments. At 1100 K, the oxygen atoms in Sr0.95Ce0.05CoO3-δ show large and highly anisotropic displacement factors, suggesting a significant ionic mobility. The test cell with a La0.8Sr0.2Ga0.83Mg0.17O3-δ-electrolyte-supported (∼300 μm thickness) configuration yields peak power densities of 0.25 and 0.48 W cm(-2) at temperatures of 1023 and 1073 K, respectively, with pure H2 as the fuel and ambient air as the oxidant. The electrochemical impedance spectra evolution with time of the symmetric cathode fuel cell measured at 1073 K shows that the Sr0.95Ce0.05CoO3-δ cathode possesses superior ORR catalytic activity and long-term stability. Mixed ionic-electronic conduction properties of Sr0.95Ce0.05CoO3-δ account for its good performance as an oxygen-reduction catalyst.

  1. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    Science.gov (United States)

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process.

  2. Cloud-Top Entrainment in Stratocumulus Clouds

    Science.gov (United States)

    Mellado, Juan Pedro

    2017-01-01

    Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

  3. Exploring Entrainment Patterns of Human Emotion in Social Media.

    Directory of Open Access Journals (Sweden)

    Saike He

    Full Text Available Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace.

  4. Exploring Entrainment Patterns of Human Emotion in Social Media.

    Science.gov (United States)

    He, Saike; Zheng, Xiaolong; Zeng, Daniel; Luo, Chuan; Zhang, Zhu

    2016-01-01

    Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace.

  5. Electrochemical formation process and phase control of Mg-Li-Ce alloys in molten chlorides

    Institute of Scientific and Technical Information of China (English)

    ZHANG Meng; HAN Wei; ZHANG Milin; ZHU Fengyan; XUE Yun; ZHANG Zhijian

    2013-01-01

    An electrochemical approach for the preparation of Mg-Li-Ce alloys by co-reduction of Mg,Li and Ce on a molybdenum electrode in KCl-LiCl-MgCl2-CeCl3 melts at 873 K was investigated.Cyclic voltammograms (CVs) and square wave voltammograms indicated that the underpotential deposition (UPD) of cerium on pre-deposited magnesium led to the formation of Mg-Ce alloys at electrode potentials around-1.87 V.The order of electrode reactions was as follows:discharge of Mg(Ⅱ) to Mg-metal,UPD of Ce on the surface of pre-deposited Mg with formation of Mg-Ce alloys,discharge of Ce(Ⅲ) to Ce-metal and after that the discharge of Li+ with the deposition of Mg-Li-Ce alloys,which was investigated by CVs,chronoamperometry,chronopotentiometry and open circuit chronopotentiometry.X-ray diffraction (XRD) illuminated that Mg-Li-Ce alloys with different phases were obtained via galvanostatic electrolysis by different current densities.The microstructures of Mg-Li-Ce alloys were characterized by optical microscopy (OM) and scanning electron microscopy (SEM),respectively.The analysis of energy dispersive spectrometry (EDS) showed that Ce existed at grain boundaries to restrain the grain growth.The compositions and the average grain sizes of Mg-Li-Ce alloys could be obtained controllably corresponding with the phase structures of the XRD patterns.

  6. Electrochemical and catalytic properties of Ni/BaCe0.75Y0.25O3-δ anode for direct ammonia-fueled solid oxide fuel cells.

    Science.gov (United States)

    Yang, Jun; Molouk, Ahmed Fathi Salem; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2015-04-01

    In this study, Ni/BaCe0.75Y0.25O3-δ (Ni/BCY25) was investigated as an anode for direct ammonia-fueled solid oxide fuel cells. The catalytic activity of Ni/BCY25 for ammonia decomposition was found to be remarkably higher than Ni/8 mol % Y2O3-ZrO2 and Ni/Ce0.90Gd0.10O1.95. The poisoning effect of water and hydrogen on ammonia decomposition reaction over Ni/BCY25 was evaluated. In addition, an electrolyte-supported SOFC employing BaCe0.90Y0.10O3-δ (BCY10) electrolyte and Ni/BCY25 anode was fabricated, and its electrochemical performance was investigated at 550-650 °C with supply of ammonia and hydrogen fuel gases. The effect of water content in anode gas on the cell performance was also studied. Based on these results, it was concluded that Ni/BCY25 was a promising anode for direct ammonia-fueled SOFCs. An anode-supported single cell denoted as Ni/BCY25|BCY10|Sm0.5Sr0.5CoO3-δ was also fabricated, and maximum powder density of 216 and 165 mW cm(-2) was achieved at 650 and 600 °C, for ammonia fuel, respectively.

  7. Fuel Cell Stations Automate Processes, Catalyst Testing

    Science.gov (United States)

    2010-01-01

    Glenn Research Center looks for ways to improve fuel cells, which are an important source of power for space missions, as well as the equipment used to test fuel cells. With Small Business Innovation Research (SBIR) awards from Glenn, Lynntech Inc., of College Station, Texas, addressed a major limitation of fuel cell testing equipment. Five years later, the company obtained a patent and provided the equipment to the commercial world. Now offered through TesSol Inc., of Battle Ground, Washington, the technology is used for fuel cell work, catalyst testing, sensor testing, gas blending, and other applications. It can be found at universities, national laboratories, and businesses around the world.

  8. Handbook on process and chemistry on nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsuyuki (ed.) [Tokyo Univ., Tokyo (Japan); Asakura, Toshihide; Adachi, Takeo (eds.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2001-12-01

    'Wet-type' nuclear fuel reprocessing technology, based on PUREX technology, has wide applicability as the principal reprocessing technology of the first generation, and relating technologies, waste management for example, are highly developed, too. It is quite important to establish a database summarizing fundamental information about the process and the chemistry of 'wet-type' reprocessing, because it contributes to establish and develop fuel reprocessing process and nuclear fuel cycle treating high burn-up UO{sub 2} fuel and spent MOX fuel, and to utilize 'wet-type' reprocessing technology much widely. This handbook summarizes the fundamental data on process and chemistry, which was collected and examined by 'Editing Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing', from FY 1993 until FY 2000. (author)

  9. Renewable hydrogen production for fossil fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.; Tevault, C.V. [and others

    1995-06-01

    In the fundamental biological process of photosynthesis, atmospheric carbon dioxide is reduced to carbohydrate using water as the source of electrons with simultaneous evolution of molecular oxygen: H{sub 2}O + CO{sub 2} + light {yields} O{sub 2} + (CH{sub 2}O). It is well established that two light reactions, Photosystems I and II (PSI and PSII) working in series, are required to perform oxygenic photosynthesis. Experimental data supporting the two-light reaction model are based on the quantum requirement for complete photosynthesis, spectroscopy, and direct biochemical analysis. Some algae also have the capability to evolve molecular hydrogen in a reaction energized by the light reactions of photosynthesis. This process, now known as biophotolysis, can use water as the electron donor and lead to simultaneous evolution of molecular hydrogen and oxygen. In green algae, hydrogen evolution requires prior incubation under anaerobic conditions. Atmospheric oxygen inhibits hydrogen evolution and also represses the synthesis of hydrogenase enzyme. CO{sub 2} fixation competes with proton reduction for electrons relased from the photosystems. Interest in biophotolysis arises from both the questions that it raises concerning photosynthesis and its potential practical application as a process for converting solar energy to a non-carbon-based fuel. Prior data supported the requirement for both Photosystem I and Photosystem II in spanning the energy gap necessary for biophotolysis of water to oxygen and hydrogen. In this paper we report the at PSII alone is capable of driving sustained simultaneous photoevolution of molecular hydrogen and oxygen in an anaerobically adapted PSI-deficient strain of Chlamydomonas reinhardtii, mutant B4, and that CO{sub 2} competes as an electron acceptor.

  10. Analysis of oxidation characteristics on combustion of diesel fuels with CeO2 nano-catalyst particulates%CeO2纳米颗粒催化柴油燃烧氧化特性分析

    Institute of Scientific and Technical Information of China (English)

    孟建; 刘军恒; 孙平; 冯浩杰

    2016-01-01

    Diesel particle emission is a major resource of particulate matter 2.5 (PM2.5) and is harmful to human health. Diesel particulate filter (DPF) is a principal method to reduce diesel PM emission. The DPF requires periodical regeneration by oxidizing the particulates deposited in filters to prevent plugging. The exhaust gas temperature of the diesel engine is considerably lower than the ignition temperature of diesel particulates. Adding a nano-catalyst directly to the fuel to lower the ignition temperature of the diesel particulates is a good method. CeO2 nano-catalyst is proved to oxide the soot with high catalytic activity and stability, and is considered as a promising catalyst for application in DPF. The influence of CeO2 nano-catalyst added in diesel oil on the oxidation and structure characteristics of diesel particulates was studied using thermogravimetric analysis (TGA) and scanning electron microscope (SEM) in this article. Three kinds of CeO2 nano-catalyst fuels were confected, in which CeO2mass fractions were 0, 50 and 100 mg/kg (F0, F50 and F100), respectively. The micro-orifice uniform deposition impactor (MOUDI) was used to collect the particulates generated by burning P0, P50 and P100. The SEM was used to study the influence of CeO2 mass fraction on the particle morphology characteristics. The effects of heating rates and CeO2 mass fraction on particle thermal oxidation characteristics were studied by thermogravimetric analysis method. The activation energy of particulates was calculated with Coast-Redfern integrate method. The results show that there were obvious clusters morphology of particulates from diesel engine fueled with the three CeO2 nano-catalyst fuels, and the particle distribution sizes were mainly concentrated between 20 nm and 70 nm, which were single peak curves. With the increase of CeO2 mass fraction, the particle sizes of P0, P50 and P100, the mean diameter of particulates decreased and the box dimension increased, accordingly. The

  11. DUPIC nuclear fuel manufacturing and process technology development

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Myung Seung; Park, J. J.; Lee, J. W. [and others

    2000-05-01

    In this study, DUPIC fuel fabrication technology and the active fuel laboratory were developed for the study of spent nuclear fuel. A new nuclear fuel using highly radioactive nuclear materials can be studied at the active fuel laboratory. Detailed DUPIC fuel fabrication process flow was developed considering the manufacturing flow, quality control process and material accountability. The equipment layout of about twenty DUPIC equipment at IMEF M6 hot cell was established for the minimization of the contamination during DUPIC processes. The characteristics of the SIMFUEL powder and pellets was studied in terms of milling conditions. The characteristics of DUPIC powder and pellet was studied by using 1 kg of spent PWR fuel at PIEF nr.9405 hot cell. The results were used as reference process conditions for following DUPIC fuel fabrication at IMEF M6. Based on the reference fabrication process conditions, the main DUPIC pellet fabrication campaign has been started at IMEF M6 using 2 kg of spent PWR fuel since 2000 January. As of March 2000, about thirty DUPIC pellets were successfully fabricated.

  12. MnO2/CeO2 for catalytic ultrasonic decolorization of methyl orange: Process parameters and mechanisms.

    Science.gov (United States)

    Zhao, He; Zhang, Guangming; Chong, Shan; Zhang, Nan; Liu, Yucai

    2015-11-01

    MnO2/CeO2 catalyst was prepared and characterized by means of Brunauer-Emmet-Teller (BET) method, X-ray diffraction (XRD) and scanning electron microscope (SEM). The characterization showed that MnO2/CeO2 had big specific surface area and MnO2 was dispersed homogeneously on the surface of CeO2. Excellent degradation efficiency of methyl orange was achieved by MnO2/CeO2 catalytic ultrasonic process. Operating parameters were studied and optimized. The optimal conditions were 10 min of ultrasonic irradiation, 1.0 g/L of catalyst dose, 2.6 of pH value and 1.3 W/ml of ultrasonic density. Under the optimal conditions, nearly 90% of methyl orange was removed. The mechanism of methyl orange degradation was further studied. The decolorization mechanism in the ultrasound-MnO2/CeO2 system was quite different with that in the ultrasound-MnO2 system. Effects of manganese and cerium in catalytic ultrasonic process were clarified. Manganese ions in solution contributed to generating hydroxyl free radical. MnO2/CeO2 catalyst strengthened the oxidation ability of ultrasound and realized complete decolorization of methyl orange.

  13. Modeling of large-scale oxy-fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    Quite some studies have been conducted in order to implement oxy-fuel combustion with flue gas recycle in conventional utility boilers as an effective effort of carbon capture and storage. However, combustion under oxy-fuel conditions is significantly different from conventional air-fuel firing......, among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a 609MW utility boiler is numerically studied, in which...... calculation of the oxy-fuel WSGGM remarkably over-predicts the radiative heat transfer to the furnace walls and under-predicts the gas temperature at the furnace exit plane, which also result in a higher incomplete combustion in the gray calculation. Moreover, the gray and non-gray calculations of the same...

  14. The art of entrainment

    NARCIS (Netherlands)

    Roenneberg, T; Daan, S; Merrow, M

    2003-01-01

    The circadian system actively synchronizes the temporal sequence of biological functions with the environment. The oscillatory behavior of the system ensures that entrainment is not passive or driven and therefore allows for great plasticity and adaptive potential. With the tools at hand, we now can

  15. DOE Coal Gasification Multi-Test Facility: fossil fuel processing technical/professional services

    Energy Technology Data Exchange (ETDEWEB)

    Hefferan, J.K.; Lee, G.Y.; Boesch, L.P.; James, R.B.; Rode, R.R.; Walters, A.B.

    1979-07-13

    A conceptual design, including process descriptions, heat and material balances, process flow diagrams, utility requirements, schedule, capital and operating cost estimate, and alternative design considerations, is presented for the DOE Coal Gasification Multi-Test Facility (GMTF). The GMTF, an engineering scale facility, is to provide a complete plant into which different types of gasifiers and conversion/synthesis equipment can be readily integrated for testing in an operational environment at relatively low cost. The design allows for operation of several gasifiers simultaneously at a total coal throughput of 2500 tons/day; individual gasifiers operate at up to 1200 tons/day and 600 psig using air or oxygen. Ten different test gasifiers can be in place at the facility, but only three can be operated at one time. The GMTF can produce a spectrum of saleable products, including low Btu, synthesis and pipeline gases, hydrogen (for fuel cells or hydrogasification), methanol, gasoline, diesel and fuel oils, organic chemicals, and electrical power (potentially). In 1979 dollars, the base facility requires a $288 million capital investment for common-use units, $193 million for four gasification units and four synthesis units, and $305 million for six years of operation. Critical reviews of detailed vendor designs are appended for a methanol synthesis unit, three entrained flow gasifiers, a fluidized bed gasifier, and a hydrogasifier/slag-bath gasifier.

  16. Modeling of a CeO2 thermochemistry reduction process for hydrogen production by solar concentrated energy

    Science.gov (United States)

    Valle-Hernández, Julio; Romero-Paredes, Hernando; Arancibia-Bulnes, Camilo A.; Villafan-Vidales, Heidi I.; Espinosa-Paredes, Gilberto

    2016-05-01

    In this paper the simulation of the thermal reduction for hydrogen production through the decomposition of cerium oxide is presented. The thermochemical cycle for hydrogen production consists of the endothermic reduction of CeO2 at high temperature, where concentrated solar energy is used as a source of heat; and of the subsequent steam hydrolysis of the resulting cerium oxide to produce hydrogen. For the thermochemical process, a solar reactor prototype is proposed; consisting of a cubic receptacle made of graphite fiber thermally insulated. Inside the reactor a pyramidal arrangement with nine tungsten pipes is housed. The pyramidal arrangement is made respect to the focal point where the reflected energy is concentrated. The solar energy is concentrated through the solar furnace of high radiative flux. The endothermic step is the reduction of the cerium oxide to lower-valence cerium oxide, at very high temperature. The exothermic step is the hydrolysis of the cerium oxide (III) to form H2 and the corresponding initial cerium oxide made at lower temperature inside the solar reactor. For the modeling, three sections of the pipe where the reaction occurs were considered; the carrier gas inlet, the porous medium and the reaction products outlet. The mathematical model describes the fluid mechanics; mass and energy transfer occurring therein inside the tungsten pipe. Thermochemical process model was simulated in CFD. The results show a temperature distribution in the solar reaction pipe and allow obtaining the fluid dynamics and the heat transfer within the pipe. This work is part of the project "Solar Fuels and Industrial Processes" from the Mexican Center for Innovation in Solar Energy (CEMIE-Sol).

  17. Water Entrainment in Concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben

    This report gives a survey of different techniques for incorporation of designed, water-filled cavities in concrete: Water entrainment. Also an estimate of the optimum size of the water inclusions is given. Water entrainment can be used to avoid self-desiccation and self-desiccation shrinkage...... during hydration [1,26]. What is needed is some sort of container which retains the shape of the water when mixed into the concrete. The container may function based on several different physical or chemical principles. Cells and gels are examples of containers found in nature. A cell membrane provides...... a boundary to water, whereas a polymer network incorporates water in its intersticious space with its affinity due to interaction energy and polymer entropy. Such containers allow water to be stored as an entity. In relation to concrete the water encapsulation may be accomplished either before or after start...

  18. 固体透氧膜法直接还原NiO-CeO_2制备CeNi_5合金%DIRECT ELECTROCHEMICAL REDUCTION OF Nio-CeO_2 POWDER FOR PREPARATION OF CeNi_5 ALLOY BY SOLID-OXYGEN-ION CONDUCTING MEMBRANE PROCESS

    Institute of Scientific and Technical Information of China (English)

    赵炳建; 鲁雄刚; 李重河; 钟庆东

    2009-01-01

    Ce-Ni base alloy CeNi_5 is often used as the hydrogen storage alloy in Ni-H batteries. Its application is more or less limited by the high cost in the traditional preparing process. Therefore, lots of researchers have paid more attention to develop a novel process with high production efficiency and low cost. The goal of the present research was to demonstrate the technical viability of a new process (solid-oxygen-ion conducting membrane process, I.e., SOM process) for the production of CeNi_5 alloy directly from its oxide precursors. This process was improved on the basis of FFC process (Fray-Farthing-Chen Cambridge process): (1) the preparation of cathode was the same as that in FFC process, (2) Cu (or Sn) liquid saturated with carbon was used as anode separated from the melt by a yttria-stabilized zirconia tube in which only oxygen-ion was permeated to prevent the side reactions and decomposition of molten salts taking place until a voltage as high as 3.5 V. This paper was focused on the preparation of hydrogen storage alloy CeNi_5 by SOM process, some parameters such as molten salt temperature, electrolytic time, configurations and phase compositions of products were investigated. The results show that NiO-CeO_2 pellets can be completely reduced to CeNi_5 alloy by SOM process. The analysis of phase compositions of intermediate products indicates that the reduction of NiO-CeO_2 starts from NiO, it reduces firstly into Ni, then reacts with newly-formed CeOCl and finally forms CeNi_5. The comparison of FFC and SOM processes shows that for SOM, NiO-CeO_2 pellet (2.5 g) can be completely reduced to CeNi_5 after electrolyzed for 3 h, and the current efficiency is 75.5%, the electrolysis energy consumption is only as low as 4.03 kW·h/kg; while for FFC, it takes 12 h for the same pellet to be reduced to pure CeNi_5, and the current efficiency is 26.1% but the electrolysis energy consumption is 10.27 kW·h/kg. It could be concluded that SOM process has a bright future

  19. The data processing and analysis for the CE-5T1 GNSS experiment

    Science.gov (United States)

    Liu, Huicui; Cao, Jianfeng; Cheng, Xiao; Peng, Jing; Tang, Geshi

    2017-02-01

    In this paper the performance of a high sensitivity GPS/GLONASS receiver mounted on CE-5T1 Service Module is studied and the data received on the first Earth-lunar transfer orbit is processed and analyzed. At least four GLONASS satellites are visible for 46% of the data span while for 98% of the data span at least four GPS satellites are visible. GLONASS serves as a necessary supplement to GPS in real time positioning whenever less than four GPS satellites are tracked, and helps to optimize the observation geometry by reducing the Position Dilution of Precision (PDOP) values by up to 77%. However, noisier GLONASS pseudorange data should be properly weighted in order not to deteriorate the positioning accuracy. Studies indicate that when the inverse square of the pseudorange measurement error of each satellite is applied as the weight value, single point positioning (SPP) accuracy improves from 57.7 m (RMS) with GPS data alone to 44.6 m (RMS) with the addition of GLONASS data. Transmitter antenna Equivalent Isotropic Radiated Power (EIRP)s of all the four blocks of GPS satellites as well as GLONASS satellites are derived from the received C/N0 data and show significant variance in sidelobe power patterns. In general, the EIRP patterns of GPS Block IIR-M and GLONASS satellite antennas have a comparatively flat power level of around 10 dB W within the off-boresight angle range of 30-80° and roll off at the off-boresight angle of about 80°, offering deep space applications greater benefits than the other three blocks of GPS satellites. In addition, an interesting close encounter happens between CE-5T1 spacecraft and GLONASS satellite R06. Investigations indicate that the PDOP value increases up to 1.4 times and the SPP accuracy deteriorates by more than 142% if satellite R06 is excluded in the positioning computation.

  20. Carbon to electricity in a solid oxide fuel cell combined with an internal catalytic gasification process

    Institute of Scientific and Technical Information of China (English)

    M. Konsolakis; G. E. Marnellos; A. Al-Musa; N. Kaklidis; I. Garagounis; V. Kyriakou

    2015-01-01

    This study explores strategies to develop highly efficient direct carbon fuel cells (DCFCs) by com‐bining a solid‐oxide fuel cell (SOFC) with a catalyst‐aided carbon‐gasification process. This system employs Cu/CeO2 composites as both anodic electrodes and carbon additives in a cell of the type:carbon|Cu‐CeO2/YSZ/Ag|air. The study investigates the impact on in situ carbon‐gasification and DCFC performance characteristics of catalyst addition and variation in the carrier gas used (inert He versus reactive CO2). The results indicate that cell performance is significantly improved by infusing the catalyst into the carbon feedstock and by employing CO2 as the carrier gas. At 800 °C, the maxi‐mum power output is enhanced by approximately 40% and 230% for carbon/CO2 and car‐bon/catalyst/CO2 systems, respectively, compared with that of the carbon/He configuration. The increase observed when employing the catalyst and CO2 as the carrier gas can be primarily at‐tributed to the pronounced effect of the catalyst on carbon‐gasification through the re‐verse‐Boudouard reaction, and the subsequent in situ electro‐oxidation of CO at the anode three‐phase boundary.

  1. Observational constraints on entrainment and the entrainment interface layer in stratocumulus

    Directory of Open Access Journals (Sweden)

    J. K. Carman

    2012-01-01

    Full Text Available Aircraft sampling of the stratocumulus-topped boundary layer (STBL during the Physics of Stratocumulus Top (POST experiment was primarily achieved using sawtooth flight patterns, during which the atmospheric layer 100 m above and below cloud top was sampled at a frequency of once every 2 min. The large data set that resulted from each of the 16 flights document the complex structure and variability of this interfacial region in a variety of conditions. In this study, we first describe some properties of the entrainment interface layer (EIL, where strong gradients in turbulent kinetic energy (TKE, potential temperature and moisture can be found. We find that defining the EIL by the first two properties tend to yield similar results, but that moisture can be a misleading tracer of the EIL. These results are consistent with studies using large-eddy simulations. We next utilize the POST data to shed light on and constrain processes relevant to entrainment, a key process in the evolution of the STBL that to-date is not well-represented even by high resolution models. We define "entrainment efficiency" as the ratio of the TKE consumed by entrainment to that generated within the STBL (primarily by cloud-top cooling. We find values for the entrainment efficiency that vary by 1.5 orders of magnitude, which is even greater than the one order magnitude that previous modeling results have suggested. Our analysis also demonstrate that the entrainment efficiency depends on the strength of the stratification of the EIL, but not on the TKE in the cloud top region. The relationships between entrainment efficiency and other STBL parameters serve as novel observational contraints for simulations of entrainment in such systems.

  2. Observational constraints on entrainment and the entrainment interface layer in stratocumulus

    Directory of Open Access Journals (Sweden)

    J. K. Carman

    2012-11-01

    Full Text Available Aircraft sampling of the stratocumulus-topped boundary layer (STBL during the Physics of Stratocumulus Top (POST experiment was primarily achieved using sawtooth flight patterns, during which the atmospheric layer 100 m above and below cloud top was sampled at a frequency of once every 2 min. The large data set that resulted from each of the 16 flights document the complex structure and variability of this interfacial region in a variety of conditions. In this study, we first describe some properties of the entrainment interface layer (EIL, where strong gradients in turbulent kinetic energy (TKE, potential temperature and moisture can be found. We find that defining the EIL by the first two properties tends to yield similar results, but that moisture can be a misleading tracer of the EIL. These results are consistent with studies using large-eddy simulations. We next utilize the POST data to shed light on and constrain processes relevant to entrainment, a key process in the evolution of the STBL that to-date is not well-represented even by high resolution models. We define "entrainment efficiency" as the ratio of the TKE consumed by entrainment to that generated within the STBL (primarily by cloud-top cooling. We find values for the entrainment efficiency that vary by 1.5 orders of magnitude, which is even greater than the one order magnitude that previous modeling results have suggested. Our analysis also demonstrates that the entrainment efficiency depends on the strength of the stratification of the EIL, but not on the TKE in the cloud top region. The relationships between entrainment efficiency and other STBL parameters serve as novel observational contraints for simulations of entrainment in such systems.

  3. Electrochemical fluorination for processing of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2016-07-05

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  4. Galvanic cell for processing of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2017-02-07

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  5. Growth of LaBr_3:Ce~(3+) Single Crystal by Vertical Bridgman Process in Nonvacuum Atmosphere

    Institute of Scientific and Technical Information of China (English)

    Hongbing Chen; Changyong Zhou; Peizhi Yang; Jinhao Wang

    2009-01-01

    The growth of LaBr_3:Ce~(3+) crystal by the vertical Bridgman process in a nonvacuum atmosphere was reported. According to the dehydration procedure of LaBr_3·7H_2O and CeBr_3·7H_2O investigated by differential thermal analysis/thermogravimetry (DTA/TG), anhydrous LaBr_3 and CeBr_3 were prepared by heating LaBr_3·7H_2O and CeBr_3·7H_2O at 240-260℃ for 5-6 h in dried HBr atmosphere. Using the feed materials prepared from the anhydrous lanthanon bromides, a 0.5 mole fraction Ce~(3+) doped LaBr_3 crystal with size ofφ25 mm×50 mm had been grown by vertical Bridgman process successfully. By sealing the feed material in a platinum crucible, the crystal could be grown in a nonvacuum atmosphere as the oxidization and volatilization of the melt could be avoided. The crystal was grown with the optimum conditions such as a growth rate of 0.5-1.0 mm/h and a temperature gradient of around 30℃/cm across solid-liquid interface under a furnace temperature of 850-880℃. The crystal was characterized by DTA/TG, X-ray diffraction (XRD), optical transmission, photoluminescence and X-ray stimulated luminescence measurement. The Bridgman process was confirmed to be promising for growing transparent LaBr_3:Ce~(3+) crystal with high optical quality.

  6. 纳米燃油添加剂CeO2提高柴油燃烧效率减少排放%Nano-fuel additive CeO2 on promoting efficient combustion and reducing emissions of diesel engine

    Institute of Scientific and Technical Information of China (English)

    邬齐敏; 孙平; 梅德清; 孙柱; 季燕平

    2013-01-01

    Developing new and highly efficient fuel additives have become an important topic of controlling engine combustion and emissions. For its unique physiochemical properties, nano-particles CeO2 makes it own a unique role in the field of catalytic combustion and exhaust gas purification. Through adding a trace amount of nano-particles CeO2 to diesel oil, two CeO2-diesel blends with the masse fraction of 50 and 100 mg/L of nano-particles CeO2 have been prepared, which makes D50C, D100C and Diesel these three test fuels, together with pure diesel as a reference. And the influences of these three test fuels on 186FA diesel engine combustion and emission have been investigated. The results show that: By using physical and chemical methods such as adding surfactant and ultrasonic processing, nano-particles CeO2 can be suspended stably in diesel. At full load at rated speed , the in-cylinder pressure peak, pressure rise rate peak and heat release rate peak have increased slightly when engine fuelled with D50C and D100C, while the corresponding crank angles are in advance accordingly, their ignition delay periods are also shorten by 1° or 2° crank angle accordingly. The engine’s brake specific fuel consumption has reduced slightly with the effective thermal efficiency slightly increased when fuelled with D50C and D100C. Four conventional pollutants have reduced with different degrees with the addition of nano-particles CeO2 into diesel, and their reduction margins are more evident with the increase of the amount of nano-particles CeO2 in diesel. As compared to diesel, at full load at rated speed, the brake specific fuel consumption of D50C and D100C have droped 1.6%and 2.3%with a increase of 1.7%and 2.3%in corresponding effective thermal efficiency. The CO、HC、NOx and smoke emissions of D50C and D100C have decreased in average by 3.4%and 6.5%、15.1%and 18.4%、2.4%and 5.4%、4.0%and 7.8%, respectively. The costs of D50C and D100C blends are 0.8%and 1.6%higher than

  7. Preparation of Well Dispersed and Ultra-Fine Ce(Zr)O2 Mixed Oxide by Mechanochemical Processing

    Institute of Scientific and Technical Information of China (English)

    程昌明; 李永绣; 周雪珍; 陈伟凡

    2004-01-01

    Ultra-fine CeO2-ZrO2 mixed oxide was successfully synthesized by wet-solid phase mechanochemical processing, Ce2(CO3)3·8H2O, ZrOCl2·xH2O and ammonia were used as reactants. It is found that the crystalline Ce2(CO3)3·8H2O and ZrOCl2·xH2O are changed to amorphous cerium and zirconium hydroxide precursor after milling with ammonia, and Ce0.15Zr0.85O2 mixed oxide with pure tetragonal phase structure and medium particle size(D50)less than 1μm is formed by calcining precursor over 673 K. The XRD patterns indicate that the crystal unite size increases with rising calcining temperature due to crystal growth. However, the particle size and BET surface area of the Ce(Zr)O2 mixed oxide decreases with rising calcining temperature, which may be attributed to the contract of particles and the vanish of holes inside grains.

  8. Catalytic oxidation with Al-Ce-Fe-PILC as a post-treatment system for coffee wet processing wastewater.

    Science.gov (United States)

    Sanabria, Nancy R; Peralta, Yury M; Montañez, Mardelly K; Rodríguez-Valencia, Nelson; Molina, Rafael; Moreno, Sonia

    2012-01-01

    The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al-Ce-Fe-PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al-Ce-Fe-PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO(2) (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce-Fe-PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al-Ce-Fe-PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater.

  9. In-situ transmission electron microscopy study of oxygen vacancy ordering and dislocation annihilation in undoped and Sm-doped CeO2 ceramics during redox processes

    Science.gov (United States)

    Ding, Yong; Chen, Yu; Pradel, Ken C.; Liu, Meilin; Lin Wang, Zhong

    2016-12-01

    Ceria (CeO2) based ceramics have been widely used for many applications due to their unique ionic, electronic, and catalytic properties. Here, we report our findings in investigating into the redox processes of undoped and Sm-doped CeO2 ceramics stimulated by high-energy electron beam irradiation within a transmission electron microscope (TEM). The reduced structure with oxygen vacancy ordering has been identified as the CeO1.68 (C-Ce2O3+δ) phase via high-resolution TEM. The reduction of Ce4+ to Ce3+ has been monitored by electron energy-loss spectroscopy. The decreased electronic conductivity of the Sm-doped CeO2 (Sm0.2Ce0.8O1.9, SDC) is revealed by electron holography, as positive electrostatic charges accumulated at the surfaces of SDC grains under electron beam irradiation, but not at CeO2 grains. The formation of the reduced CeO1.68 domains corresponds to lattice expansion compared to the CeO2 matrix. Therefore, the growth of CeO1.68 nuclei builds up strain inside the matrix, causing annihilation of dislocations inside the grains. By using in-situ high-resolution TEM and a fast OneView camera recording system, we investigated dislocation motion inside both CeO2 and SDC grains under electron beam irradiation. The dislocations prefer to dissociate into Shockley partials bounded by stacking faults. Then, the partials can easily glide in the {111} planes to reach the grain surfaces. Even the Lomer-Cottrell lock can be swept away by the phase change induced strain field. Our results revealed the high mobility of dislocations inside CeO2 and SDC grains during their respective redox processes.

  10. Distillate fuel-oil processing for phosphoric acid fuel-cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ushiba, K. K.

    1980-02-01

    The current efforts to develop distillate oil-steam reforming processes are reviewed, and the applicability of these processes for integration with the fuel cell are discussed. The development efforts can be grouped into the following processing approaches: high-temperature steam reforming (HTSR); autothermal reforming (ATR); autothermal gasification (AG); and ultra desulfurization followed by steam reforming. Sulfur in the feed is a key problem in the process development. A majority of the developers consider sulfur as an unavoidable contaminant of distillate fuel and are aiming to cope with it by making the process sulfur-tolerant. In the HTSR development, the calcium aluminate catalyst developed by Toyo Engineering represents the state of the art. United Technology (UTC), Engelhard, and Jet Propulsion Laboratory (JPL) are also involved in the HTSR research. The ATR of distillate fuel is investigated by UTC and JPL. The autothermal gasification (AG) of distillate fuel is being investigated by Engelhard and Siemens AG. As in the ATR, the fuel is catalytically gasified utilizing the heat generated by in situ partial combustion of feed, however, the goal of the AG is to accomplish the initial breakdown of the feed into light gases and not to achieve complete conversion to CO and H/sub 2/. For the fuel-cell integration, a secondary reforming of the light gases from the AG step is required. Engelhard is currently testing a system in which the effluent from the AG section enters the steam-reforming section, all housed in a single vessel. (WHK)

  11. Production of synthetic fuels using syngas from a steam hydrogasification and reforming process

    Science.gov (United States)

    Raju, Arun Satheesh Kumar

    from carbonaceous feedstocks. Experimental work on the Fischer-Tropsch synthesis has also been performed. A life cycle analysis has been performed with the objective of comparing the life cycle energy consumption and emissions of synthetic diesel fuel produced through the CE-CERT process with other fuel/vehicle combinations. The experimental and simulation results presented here demonstrate that the CE-CERT process is versatile and can potentially handle a number of different feedstocks. CE-CERT process appears to be suitable for commercialization in very large scales with a coal feedstock and also in a distributed network of smaller scale reactors utilizing localized renewable feedstocks.

  12. Large Eddy Simulation of the fuel transport and mixing process in a scramjet combustor with rearwall-expansion cavity

    Science.gov (United States)

    Cai, Zun; Liu, Xiao; Gong, Cheng; Sun, Mingbo; Wang, Zhenguo; Bai, Xue-Song

    2016-09-01

    Large Eddy Simulation (LES) was employed to investigate the fuel/oxidizer mixing process in an ethylene fueled scramjet combustor with a rearwall-expansion cavity. The numerical solver was first validated for an experimental flow, the DLR strut-based scramjet combustor case. Shock wave structures and wall-pressure distribution from the numerical simulations were compared with experimental data and the numerical results were shown in good agreement with the available experimental data. Effects of the injection location on the flow and mixing process were then studied. It was found that with a long injection distance upstream the cavity, the fuel is transported much further into the main flow and a smaller subsonic zone is formed inside the cavity. Conversely, with a short injection distance, the fuel is entrained more into the cavity and a larger subsonic zone is formed inside the cavity, which is favorable for ignition in the cavity. For the rearwall-expansion cavity, it is suggested that the optimized ignition location with a long upstream injection distance should be in the bottom wall in the middle part of the cavity, while the optimized ignition location with a short upstream injection distance should be in the bottom wall in the front side of the cavity. By employing a cavity direct injection on the rear wall, the fuel mass fraction inside the cavity and the local turbulent intensity will both be increased due to this fueling, and it will also enhance the mixing process which will also lead to increased mixing efficiency. For the rearwall-expansion cavity, the combined injection scheme is expected to be an optimized injection scheme.

  13. Development of entrained-flow gasification technologies in the Asia-Pacific region (review)

    Science.gov (United States)

    Ryzhkov, A. F.; Bogatova, T. F.; Lingyan, Zeng; Osipov, P. V.

    2016-11-01

    The gasifier that provides solid fuel conversion to produce syngas with relevant parameters is the key element of plants generating electric and thermal power, producing chemicals from coal. The purpose of this article is to analyze the modern trends in the development of gasification technologies and determine technical solutions providing the high efficiency of gasifiers and the characteristics of generated syngas that meet the requirements established by the process user. Based on the analysis of the world gasification technologies database, which includes all types of gasifiers in use and gasifiers at the construction or design stage, the data on the development of entrained-flow gasification technologies in the Asia-Pacific (AP) countries are discussed. The major constructional components of gasification plants, fuel-feed and syngas cooling methods and their influence on the efficiency and operational reliability are considered. The analysis of technological solutions confirmed the prospectivity of dry-feed entrained-flow technologies. The staged organization of the gasification process makes it possible to solve issues of increasing the economic and environmental indicators of gasification plant operation. The basic directions of modernization of entrained-flow gasifiers for improving their technical-and-economic perfomance was determined.

  14. Reduction of Pt2+ species in model Pt-CeO2 fuel cell catalysts upon reaction with methanol

    Science.gov (United States)

    Neitzel, Armin; Johánek, Viktor; Lykhach, Yaroslava; Skála, Tomáš; Tsud, Nataliya; Vorokhta, Mykhailo; Matolín, Vladimír; Libuda, Jörg

    2016-11-01

    The stability of atomically dispersed Pt2+ species on the surface of nanostructured CeO2 films during the reaction with methanol has been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The isolated Pt2+ species were prepared at low Pt concentration in Pt-CeO2 film. Additionally, Pt2+ species coexisting with metallic Pt particles were prepared at high Pt concentration. We found that adsorption of methanol yields similar decomposition products regardless of Pt concentration in Pt-CeO2 films. A small number of oxygen vacancies formed during the methanol decomposition can be replenished in the Pt-CeO2 film with low Pt concentration by diffusion of oxygen from the bulk. In the presence of supported Pt particles, a higher number of oxygen vacancies leads to a partial reduction of the Pt2+ species. The isolated Pt2+ species are reduced under rather strongly reducing conditions only, i.e. during annealing under continuous exposure to methanol. Reduction of isolated Pt2+ species results in the formation of ultra-small Pt particles containing around 25 atoms per particle or less. Such ultra-small Pt particles demonstrate excellent stability against sintering during annealing of Pt-CeO2 film with low Pt concentration under reducing conditions.

  15. Entrainment of neural oscillations as a modifiable substrate of attention.

    Science.gov (United States)

    Calderone, Daniel J; Lakatos, Peter; Butler, Pamela D; Castellanos, F Xavier

    2014-06-01

    Brain operation is profoundly rhythmic. Oscillations of neural excitability shape sensory, motor, and cognitive processes. Intrinsic oscillations also entrain to external rhythms, allowing the brain to optimize the processing of predictable events such as speech. Moreover, selective attention to a particular rhythm in a complex environment entails entrainment of neural oscillations to its temporal structure. Entrainment appears to form one of the core mechanisms of selective attention, which is likely to be relevant to certain psychiatric disorders. Deficient entrainment has been found in schizophrenia and dyslexia and mounting evidence also suggests that it may be abnormal in attention-deficit/hyperactivity disorder (ADHD). Accordingly, we suggest that studying entrainment in selective-attention paradigms is likely to reveal mechanisms underlying deficits across multiple disorders.

  16. Development of Voloxidation Process for Treatment of LWR Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. J.; Jung, I. H.; Shin, J. M. (and others)

    2007-08-15

    The objective of the project is to develop a process which provides a means to recover fuel from the cladding, and to simplify downstream processes by recovering volatile fission products. This work focuses on the process development in three areas ; the measurement and assessment of the release behavior for the volatile and semi-volatile fission products from the voloxidation process, the assessment of techniques to trap and recover gaseous fission products, and the development of process cycles to optimize fuel cladding separation and fuel particle size. High temperature adsorption method of KAERI was adopted in the co-design of OTS for hot experiment in INL. KAERI supplied 6 sets of filter for hot experiment. Three hot experiment in INL hot cell from the 25th of November for two weeks with attaching 4 KAERI staffs had been carried out. The results were promising. For example, trapping efficiency of Cs was 95% and that of I was 99%, etc.

  17. Analysis of the ATR fuel element swaging process

    Energy Technology Data Exchange (ETDEWEB)

    Richins, W.D.; Miller, G.K.

    1995-12-01

    This report documents a detailed evaluation of the swaging process used to connect fuel plates to side plates in Advanced Test Reactor (ATR) fuel elements. The swaging is a mechanical process that begins with fitting a fuel plate into grooves in the side plates. Once a fuel plate is positioned, a lip on each of two side plate grooves is pressed into the fuel plate using swaging wheels to form the joints. Each connection must have a specified strength (measured in terms, of a pullout force capacity) to assure that these joints do not fail during reactor operation. The purpose of this study is to analyze the swaging process and associated procedural controls, and to provide recommendations to assure that the manufacturing process produces swaged connections that meet the minimum strength requirement. The current fuel element manufacturer, Babcock and Wilcox (B&W) of Lynchburg, Virginia, follows established procedures that include quality inspections and process controls in swaging these connections. The procedures have been approved by Lockheed Martin Idaho Technologies and are designed to assure repeatability of the process and structural integrity of each joint. Prior to July 1994, ATR fuel elements were placed in the Hydraulic Test Facility (HTF) at the Idaho National Engineering Laboratory (AGNAIL), Test Reactor Area (TRA) for application of Boehmite (an aluminum oxide) film and for checking structural integrity before placement of the elements into the ATR. The results presented in this report demonstrate that the pullout strength of the swaged connections is assured by the current manufacturing process (with several recommended enhancements) without the need for- testing each element in the HTF.

  18. Removal of sulfamethazine antibiotics using CeFe-graphene nanocomposite as catalyst by Fenton-like process.

    Science.gov (United States)

    Wan, Zhong; Hu, Jun; Wang, Jianlong

    2016-11-01

    The presence of sulfonamide (SMT) antibiotics in aquatic environments has received increasing attention in recent years, and they are ubiquitous pollutants which cannot be effectively removed by conventional wastewater treatment processes. In this paper, the nanocomposites Ce(0)/Fe(0)-reduced graphene oxide (Ce(0)/Fe(0)-RGO) were synthesized through chemical reduction method, and characterized by Raman and FTIR before and after use. The addition of RGO can prevent the agglomeration of Ce(0) and Fe(0). The elimination of SMT can be divided into adsorption and degradation process. The adsorption of SMT onto the catalyst can enhance its degradation. The effect of pH value, concentration of H2O2, catalyst dosage, temperature and initial SMT concentration on the removal efficiency of SMT was determined. When pH = 7, T = 25 °C, H2O2 = 8 mM, Ce(0)/Fe(0)-RGO = 0.5 g/L, SMT = 20 mg/L, the removal efficiency of SMT and TOC was 99% and 73%, respectively. The stability of the catalysts was evaluated with repeated batch experiments using ethanol, water and acid as solvents to wash the used catalysts, respectively. The surface change of the catalysts after each use was characterized by Raman and FTIR analysis. The intermediates were detected by GC-MS and IC, the possible degradation pathway of SMT was tentatively proposed.

  19. Treatment on Methyl Orange-Containing Simulation Wastewater by Ce3+ Ion Homogenous Electro-Catalytic Degradation Process%Ce3+电催化降解甲基橙模拟废水的研究

    Institute of Scientific and Technical Information of China (English)

    刘咏; 邹文慧; 廖洋; 操飞; 赵仕林

    2011-01-01

    Experiment of electro-catalytic degradation for treatment of wastewater containing methyl orange was carried out with Ce3 + as catalyst. The kinetics of electro-catalytic degradation wastewater in the Ce3+ system was investigated. In order to probe the decoloring mechanism of Ce3+ to the electro-catalytic degradation of methyl orange, a diaphragmless cell and a diaphragm cell were both filled with the wastewater respectively, and then electrolyzed in different conditions (concluding the dosing method, dosing position of Ce3+ and stirring mode). The changes of cerium concentration, methyl orange concentration, the chemical oxygen demand (COD), and UV-vis spectral in the electrolysis process were determined and analyzed. The results showed that the degradation of methyl orange in the Ce3 + system accorded with firstorder kinetics. The electro-catalytic degradation reaction of Ce3+ to the decolorization of methyl orange mainly happened in the cathode. The Ce3+ in wastewater mainly reduced H2O2 to ·OH, which had strong oxidizability, and could attack the azo bonds in the methyl orange and oxidize Ce3 + to Ce4+. Then the Ce4+ , complexed with the chromophore of methyl orange, was resulting in the blue shift of its absorption peaks to achieve the decolourization.%对添加Ce3+的甲基橙模拟废水进行了电催化处理实验,考察了Ce3+电催化降解甲基橙的反应动力学;为探讨Ce3+电催化降解甲基橙的脱色机理,将废水分别置入有隔膜和无隔膜电解槽中,在不同的条件(Ce3+的投加方式、位置和搅拌方式)下进行电解,测定分析了废水在电解过程中铈含量、甲基橙浓度、COD及体系紫外-可见吸收光谱图的变化.实验结果表明,Ce3+对甲基橙的电催化反应符合一级反应动力学;Ce3+对甲基橙脱色的电催化反应主要发生在阴极;加入废水中的Ce3+主要是通过将电解生成的H2O2还原为具有强氧化性的·OH进攻甲基橙分子中的偶氮键和Ce3+氧化生成的Ce

  20. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    Energy Technology Data Exchange (ETDEWEB)

    D.E. Clark; D.C. Folz

    2010-08-29

    Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.

  1. Design of demonstration facility for advanced spent fuel conditioning process

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, W. M.; Koo, J. H.; Jeo, I. J.; Kook, D. H.; Lee, E. P.; Baek, S. R.; Lee, K. I.; You, K. S.; Park, S. W. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    The Advanced spent fuel Conditioning Process(ACP) was proposed and developed for effective management of the PWR spent fuel. The detail plan was established for demonstration and verification of the ACP, and an existing hot cell will be modified as {alpha}-{gamma} type hot cell. In this study, the process mechanical flow was analysed for the optimum arrangement to ensure effective process operation in hot cell, and the detail design of hot cell including the auxiliary facility and safety analysis was performed to secure conservative safety of hot cell system. And then, this results will be utilized for hot cell refurbishment and license.

  2. Purification of hydrogen from carbon monoxide for fuel cell application over modified mesoporous CuO-CeO2 catalysts

    KAUST Repository

    Li, Jing

    2011-08-01

    Selective oxidation of CO in H2-rich streams was carried out over a series of CuO-CeO2 catalysts doped by different transition metals (Mn, Fe, Ni, Ti, Co and Cr). The effect of the dopants on the structure and catalytic properties of CuO-CeO2 catalysts was investigated by N2 adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectra and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. The results show that the addition of Mn and Fe plays a beneficial role in extending the low-temperature catalytic activity of CuO-CeO2 catalysts, whereas the introduction of Cr and Co leads to a negative effect on the catalytic activity and resistance against CO2 and H2O. The superior catalytic performance of CuO-CeO2 catalysts with Mn and Fe doping originates from the enhanced interaction between copper and ceria, owing to the formation of more Cu+ and oxygen vacancies in the solid solution framework. While the poor catalytic activity of the Co doped counterpart is mainly ascribed to the substitution of introduced cobalt ions for copper ions in ceria lattice, resulting in the segregation of copper ions from the ceria lattice and the consequent aggregation of copper species on the ceria surface. The doping of Cr into CuO-CeO2 structure remarkably weakens the interaction between copper and ceria, which decreases the reducibility of copper species and inhibits the formation of Cu+. It accounts for the lowest catalytic activity. © 2011 Elsevier B.V.

  3. Circadian entrainment of Neurospora crassa

    NARCIS (Netherlands)

    Merrow, M.; Roenneberg, T.

    2007-01-01

    The circadian clock evolved under entraining conditions, yet most circadian experiments and much circadian theory are built around free-running rhythms. The interpretation of entrainment experiments is certainly more complex than that of free-running rhythms due to the relationship between exogenous

  4. Timescales of Massive Human Entrainment

    CERN Document Server

    Fusaroli, Riccardo; Mislove, Alan; Paxton, Alexandra; Matlock, Teenie; Dale, Rick

    2014-01-01

    The past two decades have seen an upsurge of interest in the collective behaviors of complex systems composed of many agents. In this paper, we extend concepts of entrainment to the dynamics of human collective attention. We demonstrate that large scale human entrainment may hold across a number of distinct scales, in an exquisitely time locked fashion. Using a large scale database of human communication data, we analyze and describe three different time scales of human entrainment in electronic media. We sought a distinct shared experience that provided a test bed for quantifying large scale human entrainment. We conducted a detailed investigation of the real time unfolding of human entrainment, as expressed by the content and patterns of hundreds of thousands of messages on Twitter, during the 2012 US presidential debates. By time locking these data sources, we quantify the real time impact of the debate on human attention. We show that social behavior covaries second by second to the interactional dynamics...

  5. Novel Redox Processes for Carbonaceous Fuel Conversion

    Science.gov (United States)

    He, Feng

    The current study investigates oxygen carrier development, process intensification, and oxygen carrier attrition behaviors for a number of novel, redox-based energy conversion schemes. (Abstract shortened by ProQuest.).

  6. A Brief Review of Past INL Work Assessing Radionuclide Content in TMI-2 Melted Fuel Debris: The Use of 144Ce as a Surrogate for Pu Accountancy

    Energy Technology Data Exchange (ETDEWEB)

    D. L. Chichester; S. J. Thompson

    2013-09-01

    This report serves as a literature review of prior work performed at Idaho National Laboratory, and its predecessor organizations Idaho National Engineering Laboratory (INEL) and Idaho National Engineering and Environmental Laboratory (INEEL), studying radionuclide partitioning within the melted fuel debris of the reactor of the Three Mile Island 2 (TMI-2) nuclear power plant. The purpose of this review is to document prior published work that provides supporting evidence of the utility of using 144Ce as a surrogate for plutonium within melted fuel debris. When the TMI-2 accident occurred no quantitative nondestructive analysis (NDA) techniques existed that could assay plutonium in the unconventional wastes from the reactor. However, unpublished work performed at INL by D. W. Akers in the late 1980s through the 1990s demonstrated that passive gamma-ray spectrometry of 144Ce could potentially be used to develop a semi-quantitative correlation for estimating plutonium content in these materials. The fate and transport of radioisotopes in fuel from different regions of the core, including uranium, fission products, and actinides, appear to be well characterized based on the maximum temperature reached by fuel in different parts of the core and the melting point, boiling point, and volatility of those radioisotopes. Also, the chemical interactions between fuel, fuel cladding, control elements, and core structural components appears to have played a large role in determining when and how fuel relocation occurred in the core; perhaps the most important of these reaction appears to be related to the formation of mixed-material alloys, eutectics, in the fuel cladding. Because of its high melting point, low volatility, and similar chemical behavior to plutonium, the element cerium appears to have behaved similarly to plutonium during the evolution of the TMI-2 accident. Anecdotal evidence extrapolated from open-source literature strengthens this logical feasibility for

  7. Digital mock-up for the spent fuel disassembly processes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Kim, Y. H.; Hong, D. H.; Yoon, J. S

    2000-12-01

    In this study, the graphical design system is developed and the digital mock-up is implemented for designing the spent fuel handling and disassembly processes. The system consists of a 3D graphical modeling system, a devices assembling system, and a motion simulation system. This system is used throughout the design stages from the conceptual design to the motion analysis. By using this system, all the process involved in the spent fuel handling and disassembly processes are analyzed and optimized. Also, this system is used in developing the on-line graphic simulator which synchronously simulates the motion of the equipment in a real time basis by connecting the device controllers with the graphic server through the TCP/IP network. This simulator can be effectively used for detecting the malfunctions of the process equipment which is remotely operated. Thus, the simulator enhances the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process. The graphical design system and the digital mock-up system can be effectively used for designing the process equipment, as well as the optimized process and maintenance process. And the on-line graphic simulator can be an alternative of the conventional process monitoring system which is a hardware based system.

  8. Proceedings of the workshop on hydrocarbon processing mixing and scale-up problems. [Fuels processing for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, J. D. [ed.

    1978-01-01

    A workshop was convened by the Division of Fossil Fuel Utilization of the US Department of Energy in cooperation with the Particulate and Multiphase Process Program of the National Science Foundation to identify needs for fundamental engineering support for the design of chemical reactors for processing heavy hydrocarbon liquids. The problems associated with dispersing liquid hydrocarbons in a reacting gas and mixing within the gas phase are of primary concern. The transactions of the workshop begin with an introduction to the immediate goals of the Department of Energy. Fuel cell systems and current research and development are reviewed. Modeling of combustion and the problems of soot formation and deposits in hydrocarbon fuels are next considered. The fluid mechanics of turbulent mixing and its effect on chemical reactions are then presented. Current experimental work and process development provide an update on the present state-of-the-art.

  9. A Pd/C-CeO2 Anode Catalyst for High-Performance Platinum-Free Anion Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Miller, Hamish A; Lavacchi, Alessandro; Vizza, Francesco; Marelli, Marcello; Di Benedetto, Francesco; D'Acapito, Francesco; Paska, Yair; Page, Miles; Dekel, Dario R

    2016-05-10

    One of the biggest obstacles to the dissemination of fuel cells is their cost, a large part of which is due to platinum (Pt) electrocatalysts. Complete removal of Pt is a difficult if not impossible task for proton exchange membrane fuel cells (PEM-FCs). The anion exchange membrane fuel cell (AEM-FC) has long been proposed as a solution as non-Pt metals may be employed. Despite this, few examples of Pt-free AEM-FCs have been demonstrated with modest power output. The main obstacle preventing the realization of a high power density Pt-free AEM-FC is sluggish hydrogen oxidation (HOR) kinetics of the anode catalyst. Here we describe a Pt-free AEM-FC that employs a mixed carbon-CeO2 supported palladium (Pd) anode catalyst that exhibits enhanced kinetics for the HOR. AEM-FC tests run on dry H2 and pure air show peak power densities of more than 500 mW cm(-2) .

  10. Sustainable Production of Asphalt using Biomass as Primary Process Fuel

    DEFF Research Database (Denmark)

    Bühler, Fabian; Nguyen, Tuong-Van; Elmegaard, Brian

    2016-01-01

    The production of construction materials is very energy intensive and requires large quantities of fossil fuels.Asphalt is the major road paving material in Europe and is being produced primarily in stationary batch mixasphalt factories. The production process requiring the most energy...... is the heating and drying of aggregate,where natural gas, fuel oil or LPG is burned in a direct-fired rotary dryer. Replacing this energy source with amore sustainable one presents several technical and economic challenges, as high temperatures, short startuptimes and seasonal production variations are required....... This paper analyses different pathways for the useof biomass feedstock as a primary process fuel. The analysed cases consider the gasification of straw andwood chips and the direct combustion of wood pellets. The additional use of syngas from the gasifier for theproduction of heat or combined heat and power...

  11. Forecasting Inundation from Debris Flows That Grow By Entraining Sediment

    Science.gov (United States)

    Reid, M. E.; Coe, J. A.; Brien, D. L.

    2014-12-01

    Destructive debris flows often grow, and extend their runouts, by entraining sediment as they travel. However, incorporating varied entrainment processes into physics-based flow routing models is challenging. As an alternative, we developed a relatively simple, automated method for forecasting the inundation hazards posed by debris flows that entrain sediment and coalesce from multiple flows. Within a drainage network, we amalgamate the effects of many possible debris flows with each flow volume proportional to an entrainment rate scaled by the upslope contributing area, and then use these volumes in the USGS GIS-based inundation model LAHARZ. Our approach only requires estimates of two parameters: spatial entrainment rate & maximum entrainment area or maximum volume. Our procedure readily integrates various sediment sources and it can portray different inundation hazard levels on a GIS-based map by varying our two parameters. We applied this approach to part of the Coast Range, southern Oregon, USA. Using aerial photography, we mapped debris flows triggered by a large 1996 rain event on a LiDAR-derived topographic base, and identified initiation locations, travel paths, and areas of channel erosion and deposition. Many catchments experienced multiple debris flows that coalesced downstream and about 95% of the debris flows entrained sediment as they traveled. Flows typically stopped entraining sediment before the upslope contributing area reached ~500,000 m2. We used pre- and post-debris-flow stereo photos to estimate spatial entrainment rates in four clear-cut catchments having both channel erosion and coalescence of flows; these rates varied from 0.12 to 0.2 m3/m2. GIS-based inundation maps, using our automated methods, are quite similar to the mapped flow paths and deposits. Given appropriate parameters, our approach could be applied to a variety of steep, channelized environments where entrainment is important, such as alpine and post-wildfire slopes.

  12. Effect of fuel size and process temperature on fuel gas quality from CFB gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Van der Drift, A.; Van Doorn, J. [ECN Biomass, Petten (Netherlands)

    2000-07-01

    A bench-scale circulating fluidized bed (CFB) gasifier with a capacity of max. 500 kWh{sub th} has been used to study the effect of fuel size and process temperature. A higher process temperature (range tested: 750 to 910C) results in more air needed to maintain the desired temperature, a lower heating value of the product gas, a higher carbon conversion and a net increase of cold gas efficiency of the gasifier. A higher process temperature also results in less heavy tars. However, light tars (measured using the solid phase adsorbent (SPA) method) do show an odd behaviour. Some individual components within the group of light tars even increase in concentration when process temperature is raised. The main reason probably is that heavy tars decompose to these relatively stable light tar components. The particle size of the fuel does influence some product gas parameters considerably. The presence of small particles seems to increase the (heavy) tar concentration and decrease the conversion of fuel-nitrogen to ammonia. Small particles can also be responsible for large temperature gradients along the axis of the riser of a CFB-gasifier. This effect can be avoided by either mixing the fuel with larger particles or feed the small particles at the bottom of the reactor. 5 refs.

  13. Pyrolysis process for producing fuel gas

    Science.gov (United States)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  14. High temperature polymer fuel cells and their Interplay with fuel processing systems

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, R.

    2003-01-01

    This paper reports recent results from our group on polymer electrolyte membrane fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all....... The high working temperature allows for utilization of the excess heat for fuel processing. Moreover, it provides an excellent CO tolerance of several percent, and the system needs no purification of hydrogen from a reformer. Continuous service for over 6 months at 150°C has been demonstrated....

  15. A New Combustion Process for Nanosized BaCe0.95Y0.05O3-δ Powders

    Institute of Scientific and Technical Information of China (English)

    孟波; 谭小耀; 张宝砚; 杨乃涛

    2004-01-01

    Nanosized BaCe0.95Y0.05O3-δ powders with the homogeneous composition were synthesized by a new combustion process based on the Pechini method.A polymeric precursor sol was formed by use of citric acid and ethylene glycol as the chelating agents of metal ions.The perovskite-type BaCe0.95Y0.05O3-δ powders with uniform shape and smaller than 40 nm in sized were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide.It was found the particle size could be controlled by modulating the quantities of nitric acid and ammonium hydroxide,the quantities of the residue,carbonate ions were also affected by the quantities of the citric acid and ethylene glycol.

  16. Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany; Ganzheitliche Analyse thermochemischer Verfahren bei der Nutzung fester Biomasse zur Kraftstoffproduktion in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Henssler, Martin

    2015-04-28

    According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO{sub 2eq}-reduction compared to the fossil reference fuel (83.8 g CO{sub 2eq}/MJ{sub fuel} /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO{sub 2eq}-savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H{sub 2}) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V {sup registered} -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H{sub 2}). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H{sub 2}-production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO{sub 2eq}-saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO{sub 2eq}-saving is between 72 (H{sub 2}) and 95 % (Fischer

  17. Physical Properties of Mixed Conductor Solid Oxide Fuel Cell Anodes of Doped CeO2

    OpenAIRE

    Mogensen, Mogens Bjerg; Lindegaard, Thomas; Hansen, Uffe Rud; Mogensen, Gurli

    1994-01-01

    Samples of CeO2 doped with oxides such as CaO and Gd2O3 were prepared. Their conductivities and expansions onreduction were measured at 1000°C, and the thermal expansion coefficients in the range 50 to 1000°C were determined. Theionic and electronic conductivity were derived from curves of total conductivity vs. oxygen partial pressure. For both typesof conductivity a dependence on dopant valency was observed. The electronic conductivity was independent of dopantradius in contrast to the ioni...

  18. Process development and fabrication for sphere-pac fuel rods. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Welty, R.K.; Campbell, M.H.

    1981-06-01

    Uranium fuel rods containing sphere-pac fuel have been fabricated for in-reactor tests and demonstrations. A process for the development, qualification, and fabrication of acceptable sphere-pac fuel rods is described. Special equipment to control fuel contamination with moisture or air and the equipment layout needed for rod fabrication is described and tests for assuring the uniformity of the fuel column are discussed. Fuel retainers required for sphere-pac fuel column stability and instrumentation to measure fuel column smear density are described. Results of sphere-pac fuel rod fabrication campaigns are reviewed and recommended improvements for high throughput production are noted.

  19. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  20. Modular, High-Volume Fuel Cell Leak-Test Suite and Process

    Energy Technology Data Exchange (ETDEWEB)

    Ru Chen; Ian Kaye

    2012-03-12

    Fuel cell stacks are typically hand-assembled and tested. As a result the manufacturing process is labor-intensive and time-consuming. The fluid leakage in fuel cell stacks may reduce fuel cell performance, damage fuel cell stack, or even cause fire and become a safety hazard. Leak check is a critical step in the fuel cell stack manufacturing. The fuel cell industry is in need of fuel cell leak-test processes and equipment that is automatic, robust, and high throughput. The equipment should reduce fuel cell manufacturing cost.

  1. Effect of fuel-to-nitrate ratio on the powder characteristics of nanosized CeO{sub 2} synthesized by mixed fuel combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Palneedi, Haribabu; Mangam, Venu; Das, Siddhartha [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Das, Karabi, E-mail: karabi@metal.iitkgp.ernet.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2011-10-13

    Highlights: > Preparation of nanosized ceria powder by mixed fuel combustion synthesis. > Effect of variation of fuel-to-nitrate ratio on the powder characteristics. > Correlation between the results of XRD, Raman spectroscopy, and BET surface analysis. - Abstract: Synthesis of nanocrystalline ceria powders is carried out through the mixed fuel combustion approach by using different combinations of glycine and citric acid. The powders obtained with different fuel-to-nitrate (F/N) ratios are characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), BET surface area analysis, and Raman spectroscopy. TGA and FTIR spectroscopy studies have revealed the presence of carbonaceous species and residual volatiles in the combustion synthesized ceria powders. It is observed that the variation of fuel-to-nitrate ratio has a profound influence on the carbonaceous residues from combustion, crystallite size (11-44 nm), surface area (9-39 m{sup 2}/g) and morphology of the resultant powders. The Raman spectroscopy results on the variation of particle size with F/N ratio are consistent with the conclusions made from X-ray line broadening and BET surface area analysis.

  2. Used nuclear fuel separations process simulation and testing

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D. [Argonne National Laboratory: 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2013-07-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  3. Performance and sulfur poisoning of Ni/CeO2 impregnated La0.75Sr0.25Cr0.5Mn0.5O3-δ anode in solid oxide fuel cells

    Science.gov (United States)

    Li, Yiqian; Zhang, Yaohui; Zhu, Xingbao; Wang, Zhihong; Lü, Zhe; Huang, Xiqiang; Zhou, Yongjun; Zhu, Lin; Jiang, Wei

    2015-07-01

    In this study, comparison experiments are conducted based on yttria-stabilized zirconia (YSZ) electrolyte supported single solid oxide fuel cells (SOFCs) with pure La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCrM) or Ni/CeO2 impregnated LSCrM anodes. The single cells are tested in dry H2 and H2/H2S (50 ppm) mixture, respectively. Compared with the pure LSCrM anode, the cell with Ni/CeO2 impregnated LSCrM presents a significant performance improvement when the pure H2 is fueled to the anode, and shows a good stability during a constant-current discharge testing (398 mA cm-2). When the fuel is switched to H2/H2S mixture, the cell with Ni/CeO2 impregnated LSCrM anode still shows a remarkable constant-current discharge (120 mA cm-2) performance compared with pure LSCrM anode. The Ni/CeO2 impregnation can improve the electrochemical performance of the LSCrM anode without any sacrifice of sulfur tolerance ability. The Ni/CeO2 impregnated LSCrM might be a potential anode material for solid oxide fuel cell operating in sulfur-containing fuels. The XRD and XPS results demonstrate that the anode poisoning product is composed of adsorbed sulfur, metal sulfides and sulfate radical. The mass spectrum result confirms that the poisoning mechanism involves the reaction of sulfur with anode rather than the direct reaction between H2S gas and anode.

  4. Sediment particle entrainment in an obstructed annular

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Bruno Venturini; Siqueira, Renato do Nascimento [Faculdade do Centro Leste (UCL), Serra, ES (Brazil). Lab. de Fenomenos de Transporte], e-mail: brunovl@ucl.br, e-mail: renatons@ucl.br

    2006-07-01

    Flow in an annular region with internal cylinder rotation is a classic problem in fluid mechanics and has been widely studied. Besides its importance as a fundamental problem, flow in annular regions has several practical applications. This project was motivated by an application of this kind of flow to the drilling of oil and gas wells. In this work, an erosion apparatus was constructed in order to study the effect of the internal cylinder rotation on particle entrainment in an obstructed annular space and bed package as well. The study also analyzed the influence of height of the particles bed on the process performance. The experiment was designed so that the internal cylinder rotation could be measured by an encoder. The fluid temperature was measured by a thermocouple and the experiments were carried out at the temperature of 25 deg C. The study revealed that the particle entrainment for the height of the bed that is close to the center of the cylinders is negligible and the internal cylinder rotation provokes the movement and packing of the bed. For lower height of the bed, with same dimension of the annular gap, the particle entrainment process was satisfactory and the bed compaction was smaller than in the previous case, leading to a more efficient cleaning process in the annular space. (author)

  5. Cone-shaped cylindrical Ce0.9Gd0.1O1.95 electrolyte prepared by slip casting and its application to solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    SUI Jing; DONG Lifeng; LIU Jiang

    2012-01-01

    A cone-shaped gadolinium doped ceria (Ce0.9Gd0.1O1.95,GDC) electrolyte cylinder with a thin wall was fabricated using slip casting technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm,the length was 1.0 cm,and the thickness of the wall was 0.026 cm after sintering.Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process.A single solid oxide fuel cell (SOFC) was prepared with the cone-shaped electrolyte,NiO-GDC (70:30 wt.%) anode and Sm0.5Sr0.5CoO3 (SSC) cathode.Its electrochemical performance (Ⅰ- Ⅴcurve) and electrochemical impedance spectroscopy (EIS) were studied with humidified hydrogen as the fuel and air as the oxidant.The maximum output power density was about 300 mW/cm2 at 700 ℃.The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.

  6. Understanding the transport processes in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Cheah, May Jean

    Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices suitable for automotive, stationary and portable applications. An engineering challenge that is hindering the widespread use of PEM fuel cells is the water management issue, where either a lack of water (resulting in membrane dehydration) or an excess accumulation of liquid water (resulting in fuel cell flooding) critically reduces the PEM fuel cell performance. The water management issue is addressed by this dissertation through the study of three transport processes occurring in PEM fuel cells. Water transport within the membrane is a combination of water diffusion down the water activity gradient and the dragging of water molecules by protons when there is a proton current, in a phenomenon termed electro-osmotic drag, EOD. The impact of water diffusion and EOD on the water flux across the membrane is reduced due to water transport resistance at the vapor/membrane interface. The redistribution of water inside the membrane by EOD causes an overall increase in the membrane resistance that regulates the current and thus EOD, thereby preventing membrane dehydration. Liquid water transport in the PEM fuel cell flow channel was examined at different gas flow regimes. At low gas Reynolds numbers, drops transitioned into slugs that are subsequently pushed out of the flow channel by the gas flow. The slug volume is dependent on the geometric shape, the surface wettability and the orientation (with respect to gravity) of the flow channel. The differential pressure required for slug motion primarily depends on the interfacial forces acting along the contact lines at the front and the back of the slug. At high gas Reynolds number, water is removed as a film or as drops depending on the flow channel surface wettability. The shape of growing drops at low and high Reynolds number can be described by a simple interfacial energy minimization model. Under flooding conditions, the fuel cell local current

  7. Towards Extrusion of Ionomers to Process Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Jean-Yves Sanchez

    2011-07-01

    Full Text Available While Proton Exchange Membrane Fuel Cell (PEMFC membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.

  8. Use of Hansen Solubility Parameters in Fuel Treatment Processes

    Science.gov (United States)

    2014-03-17

    Charts 3. DATES COVERED (From - To) Jan 2014- Mar 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER In-House Use of Hansen Solubility Parameters in...distribution is unlimited. AFRL Public Affairs Clearance # USE OF HANSEN SOLUBILITY PARAMETERS IN FUEL TREATMENT PROCESSES 17 March 2014 Andrew J...Treatment Needs – Hansen Solubility Parameters • Dyes – Experimental HSP Determination – Extrapolation to Other Dyes • Predictions for Extraction Fluids

  9. Technical and regulatory review of the Rover nuclear fuel process for use on Fort St. Vrain fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T. [Science Applications International Corp., Idaho Falls, ID (United States)

    1993-02-01

    This report describes the results of an analysis for processing and final disposal of Fort St. Vrain (FSV) irradiated fuel in Rover-type equipment or technologies. This analysis includes an evaluation of the current Rover equipment status and the applicability of this technology in processing FSV fuel. The analyses are based on the physical characteristics of the FSV fuel and processing capabilities of the Rover equipment. Alternate FSV fuel disposal options are also considered including fuel-rod removal from the block, disposal of the empty block, or disposal of the entire fuel-containing block. The results of these analyses document that the current Rover hardware is not operable for any purpose, and any effort to restart this hardware will require extensive modifications and re-evaluation. However, various aspects of the Rover technology, such as the successful fluid-bed burner design, can be applied with modification to FSV fuel processing. The current regulatory climate and technical knowledge are not adequately defined to allow a complete analysis and conclusion with respect to the disposal of intact fuel blocks with or without the fuel rods removed. The primary unknowns include the various aspects of fuel-rod removal from the block, concentration of radionuclides remaining in the graphite block after rod removal, and acceptability of carbon in the form of graphite in a high level waste repository.

  10. A high performance BaZr0.1Ce0.7Y0.2O3-δ-based solid oxide fuel cell with a cobalt-free Ba0.5Sr0.5FeO3-δ–Ce0.8Sm0.2O2-δ composite cathode

    NARCIS (Netherlands)

    Sun, Wenping; Shi, Zhen; Fang, Shumin; Yan, Litao; Zhu, Zhiwen; Liu, Wei

    2010-01-01

    A cobalt-free Ba0.5Sr0.5FeO3-δ–Ce0.8Sm0.2O2-δ (BSF–SDC) composite is employed as a cathode for an anode-supported proton-conducting solid oxide fuel cells (H-SOFCs) using BaZr0.1Ce0.7Y0.2O3-δ (BZCY) as the electrolyte. The chemical compatibility between BSF and SDC is evaluated. The XRD results show

  11. Electrochemical characterization of Pr{sub 2}CuO{sub 4}–Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} composite cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kolchina, L.M. [Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation); Lyskov, N.V. [Institute of Problems of Chemical Physics RAS, Acad. Semenov Av. 1, Chernogolovka 142432 (Russian Federation); Petukhov, D.I. [Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation); Mazo, G.N., E-mail: mazo@inorg.chem.msu.ru [Department of Chemistry, Moscow State University, Moscow 119992 (Russian Federation)

    2014-08-25

    Highlights: • PCO–GDC composites are studied as a cathode for SOFCs. • The rate-determined step of the overall electrode process vs. temperature was defined. • PCO–GDC33 composite gave the lowest area surface resistance of 0.41 Ω cm{sup 2} at 700 °C. • PCO–GDC33 is preferred to use as a cathode material for IT-SOFCs. - Abstract: Pr{sub 2}CuO{sub 4}–Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} (PCO–GDC) composites screen printed on Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} (GDC) electrolyte were considered as a cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs). Phase composition, microstructure and electrochemical properties were investigated by X-ray powder diffraction (XRD), scanning electron microscopy and AC impedance spectroscopy, respectively. The oxygen reduction on porous PCO–GDC electrode applied on CGO electrolyte was studied in a symmetrical cell configuration by AC impedance spectroscopy at OCV conditions at 670–730 °C and p{sub O{sub 2}}=10{sup -2}-0.21atm. The charge transfer process and the dissociation of adsorbed molecular oxygen were found to be rate-determining steps of the oxygen reduction reaction. Results reveal that both GDC addition and electrode morphology have strong influence on area specific resistance (ASR) of the electrode/electrolyte interface. The lowest ASR value of 0.41 Ω cm{sup 2} was achieved for the composition containing 33 wt.% GDC at 700 °S in air. The data obtained allow to consider the PCO–GDC33 composite as a promising cathode material for IT-SOFCs.

  12. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    Science.gov (United States)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c) 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  13. Experimental study of entrainment phenomenon in a trapped vortex combustor

    Institute of Scientific and Technical Information of China (English)

    Zhang Rongchun; Fan Weijun

    2013-01-01

    Trapped vortex combustor (TVC) is an advanced low-pollution gas turbine combustor,with the adoption of staged combustion technique.To achieve low-pollutant emission and better combustion performance,the proportion of the air flow in each combustion zone should be precisely determined in the design of the combustor.Due to the presence of entrainment phenomenon,the total air flow in the cavity zone is difficult to estimate.To overcome the measurement difficulty,this study adopts the indirect measurement approach in the experimental research of entrainment phenomenon in the cavity.In accordance with the measurement principle,a TVC model fueled by methane is designed.Under two experimental conditions,i.e.with and without direct air intake in the cavity,the influence of the mainstream air flow velocity,the air intake velocity in the cavity,the height of inlet channel,the structure of holder and the structural proportion of the cavity on entrainment in the cavity is studied,respectively,through experiment at atmospheric temperature and pressure.The results suggest that the air flow velocity of mainstream,the air intake velocity of the cavity and the structure of the holder exert significant influence on the air entrainment,while the influence of structural proportion of the cavity is comparatively insignificant.The square root of momentum ratio of cavity air to mainstream air could be used to analyze the correlation of the entrainment data.

  14. Study of Air Entrainment by a Horizontal Plunging Liquid Jet

    Science.gov (United States)

    Trujillo, Mario; Deshpande, Suraj; Wu, Xiongjun; Chahine, Georges

    2009-11-01

    The process of air entrainment following the impact of an initially horizontal circular water jet on a pool of water has been studied computationally and experimentally. It has been found that the entrainment of air cavities in the near field region is periodic, not continuous as reported in earlier studies. The simulations are based on a Volume-of-Fluid methodology with interfacial compression using a modified version of the open source utilities, OpenFoam. Close agreement with experiments is reported on the creation of cavities in the near field, where air entrainment occurs. The period of entrainment is found to be proportional to g, and a simplified closed-form solution for this periodic event is presented. An overall physical picture of the mechanisms leading to bubble formation is given. The far field, which is characterized by the presence of small bubbles is only partially resolved computationally. Comparisons against velocity data are performed in this region leading to adequate qualitative agreement.

  15. Physical Simulation of Burning Process of Alternative Engine Fuels

    Directory of Open Access Journals (Sweden)

    M. S. Assad

    2008-01-01

    Full Text Available Visualization of burning process in the closed vessel has been fulfilled with the help of method high-speed photography through a transparent glass. This method as an efficient means for investigation of fast processes permits to obtain a visual, convenient visual perception insight about the development of the burning process and understand peculiarities of the development of flame in the closed vessels.The paper contains a description of an experimental stand and methodology for execution of an experiment on visualization of the flame development and measurement of main parameters of the burning process in a closed vessel that is in the simulating combustion chamber.According to the obtained photos an analysis of form, structure and dynamics of flame front development has been carried out; some peculiarities and differences of flames of various fuel-air mixtures have been established and the paper proves an occurrence of the secondary glow during burning in the closed vessel.Body of data obtained with the help of the visualization of burning process makes it possible to determine main parameters of the burning process. In particular, relation of the pressure developed in the chamber with the mass of burnt-out mixture has been investigated and dependence has been obtained that shows the law of fuel burning-out in the graphic form.

  16. Differential entrainment of neuroelectric delta oscillations in developmental dyslexia.

    Directory of Open Access Journals (Sweden)

    Fruzsina Soltész

    Full Text Available Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language, has been associated with behavioural entrainment deficits. It has been proposed that the phonological 'deficit' that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, 'temporal sampling theory'. Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz, relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, 'phase locking' and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time for control participants only.

  17. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  18. Comment on 'The characterization of doped CeO2 electrodes in solid oxide fuel cells' by B.G. Pound

    DEFF Research Database (Denmark)

    Ranløv, J.; Poulsen, F.W.; Mogensen, Mogens Bjerg

    1993-01-01

    Electrode tests and ac impedance measurements presented by Pound on Ni, Co and Mn doped CeO2 are reviewed. We find that the stability of solid solutions in the systems of NiO-CeO2 and CoO-CeO2 are improbable and that therefore the interpretation of ac impedance data and electrode tests should...

  19. Numerical study on onset of gas entrainment from free surface

    Energy Technology Data Exchange (ETDEWEB)

    Tomoaki Kunugi [Department of Nuclear engineering, Kyoto University, Yoshida Sakyou-ku Kyoto (Japan); Toshiki Ezure; Takaaki Sa ka; Kei Ito [Japan Nuclear Cycle Development Institute, 4002 Narita-cho, O-arai-cho Higashi-ibaraki-gun, 311- 1393 (Japan)

    2005-07-01

    Full text of publication follows: A fast breeder nuclear reactor (FBR) has an important role for closing a fuel cycle system in fission nuclear reactor systems. The liquid sodium cooling system of a latest compact FBR concept consists of two loops connected to a heat exchanger (HEX) and a pool-typed reactor vessel with the upper core structures (UCS). The high temperature sodium coolant comes from the reactor core to the vessel and flows through the hot legs towards the HEX. In order to design the compact FBR, it is necessary to clarify a criterion of a cover-gas entrainment from the coolant free surface of the vessel to the HEX through the hot leg. The surface velocity of the coolant in the vessel is considered as one of the key parameters of the gas entrainment phenomena: bubble entrained by free surface vortex, entraining bubbles caused by supercritical flows and gas entrainment by wave breaking. However, there is no clear quantitative explanation and criterion regarding the on-set condition of gas entrainment from the free surface until today. In the present study, numerical simulation of the gas entrainment and the bubble transport from free surface to the hot leg regarding the bubble entrainment due to the supercritical surface flows have been performed by means of the Multi-interface and Advection and Reconstruction Solver (MARS) and the numerical results are compared with that of the small scale fundamental experiments. The final goal of this study is to establish the evaluation procedure and criterion of these phenomena. Experiment performed by Moriya was chosen as the reference data for this comparison study. The test section consisted of an open-upped rectangular box with the inlet and outlet nozzles located at bottom of the box and almost a half height of the test section was filled with water. Resulting from these simulations, the gas entrainment phenomena were observed for both cases at certain flow conditions. In two-dimensional simulations, we found

  20. Flicker regularity is crucial for entrainment of alpha oscillations

    Directory of Open Access Journals (Sweden)

    Annika Notbohm

    2016-10-01

    are compared to those presented during the maximum.In the second experiment stimulation with higher light intensity during both rhythmic and arrhythmic stimulation lead to an increased behavioral modulation depth, supposedly as a consequence of stronger entrainment during rhythmic stimulation.Altogether, our results reveal evidence for rhythmic and arrhythmic visual stimulation to induce fundamentally different processes in the brain: we suggest that rhythmic but not arrhythmic stimulation interacts with ongoing alpha oscillations

  1. Plate-Based Fuel Processing System Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Faz; Helen Liu; Jacques Nicole; David Yee

    2005-12-22

    On-board reforming of liquid fuels into hydrogen is an enabling technology that could accelerate consumer usage of fuel cell powered vehicles. The technology would leverage the convenience of the existing gasoline fueling infrastructure while taking advantage of the fuel cell efficiency and low emissions. Commercial acceptance of on-board reforming faces several obstacles that include: (1) startup time, (2) transient response, and (3) system complexity (size, weight and cost). These obstacles are being addressed in a variety of projects through development, integration and optimization of existing fuel processing system designs. In this project, CESI investigated steam reforming (SR), water-gas-shift (WGS) and preferential oxidation (PrOx) catalysts while developing plate reactor designs and hardware where the catalytic function is integrated into a primary surface heat exchanger. The plate reactor approach has several advantages. The separation of the reforming and combustion streams permits the reforming reaction to be conducted at a higher pressure than the combustion reaction, thereby avoiding costly gas compression for combustion. The separation of the two streams also prevents the dilution of the reformate stream by the combustion air. The advantages of the plate reactor are not limited to steam reforming applications. In a WGS or PrOx reaction, the non-catalytic side of the plate would act as a heat exchanger to remove the heat generated by the exothermic WGS or PrOx reactions. This would maintain the catalyst under nearly isothermal conditions whereby the catalyst would operate at its optimal temperature. Furthermore, the plate design approach results in a low pressure drop, rapid transient capable and attrition-resistant reactor. These qualities are valued in any application, be it on-board or stationary fuel processing, since they reduce parasitic losses, increase over-all system efficiency and help perpetuate catalyst durability. In this program, CESI

  2. An ion-imprinted polymer supported by attapulgite with a chitosan incorporated sol-gel process for selective separation of Ce(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    Chun Xiang Li; Jian Ming Pan; Jie Gao; Yong Sheng Yan; Gan Qing Zhao

    2009-01-01

    The surface ion-imprinting concept and chitosan incorporated sol-gel process were applied to the synthesis of a new attapulgite-supported polymer for selective separation of Ce(Ⅲ) from aqueous solution. The imprinting mechanism of prepared ion-imprinted polymer were discussed with the Characteristics of FT-IR and SEM. Results from the experiments of adsorption capacity and selectivity suggested that ion-imprinted polymer offered a fast kinetics for the adsorption of Ce(Ⅲ) under the optimum conditions. Its maximum adsorption capacity was 38.02 mg/g, and the selective recognition towards Ce(Ⅲ) was much higher than that of the non-imprinted polymer and attapulgite. The prepared functional polymer was shown to be promising for selective separation and enrichment of trace Ce(Ⅲ) in environmental samples.

  3. Femtosecond laser processing of fuel injectors - a materials processing evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B C; Wynne, A

    2000-12-16

    Lawrence Livermore National Laboratory (LLNL) has developed a new laser-based machining technology that utilizes ultrashort-pulse (0.1-1.0 picosecond) lasers to cut materials with negligible generation of heat or shock. The ultrashort pulse laser, developed for the Department of Energy (Defense Programs) has numerous applications in operations requiring high precision machining. Due to the extremely short duration of the laser pulse, material removal occurs by a different physical mechanism than in conventional machining. As a result, any material (e.g., hardened steel, ceramics, diamond, silicon, etc.) can be machined with minimal heat-affected zone or damage to the remaining material. As a result of the threshold nature of the process, shaped holes, cuts, and textures can be achieved with simple beam shaping. Conventional laser tools used for cutting or high-precision machining (e.g., sculpting, drilling) use long laser pulses (10{sup -8} to over 1 sec) to remove material by heating it to the melting or boiling point (Figure 1.1a). This often results in significant damage to the remaining material and produces considerable slag (Figure 1.2a). With ultrashort laser pulses, material is removed by ionizing the material (Figure 1.1b). The ionized plasma expands away from the surface too quickly for significant energy transfer to the remaining material. This distinct mechanism produces extremely precise and clean-edged holes without melting or degrading the remaining material (Figures 1.2 and 1.3). Since only a very small amount of material ({approx} <0.5 microns) is removed per laser pulse, extremely precise machining can be achieved. High machining speed is achieved by operating the lasers at repetition rates up to 10,000 pulses per second. As a diagnostic, the character of the short-pulse laser produced plasma enables determination of the material being machined between pulses. This feature allows the machining of multilayer materials, metal on metal or metal on

  4. Conversion of microalgae to jet fuel: process design and simulation.

    Science.gov (United States)

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming.

  5. Selective CO Methanation Catalysts for Fuel Processing Applications

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Wang, Yong; Xia, Guanguang G.; Strohm, James J.; Holladay, Jamie D.; Palo, Daniel R.

    2007-07-15

    Abstract Selective CO methanation as a strategy for CO removal in micro fuel processing applications was investigated over Ru-based catalysts. Ru loading, pretreatment and reduction conditions, and choice of support were shown to affect catalyst activity, selectivity, and stability. Even operating at a gas-hourly-space-velocity as high as 13,500 hr-1, a 3%Ru/Al2O3 catalyst was able to lower CO in a reformate to less than 100 ppm over a wide temperature range from 240oC to 285 oC, while keeping hydrogen consumption below 10%.

  6. Phase equilibria of continuous fossil fuel process oils

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M.J.; Weil, S.A. (Institute of Gas Technology, Chicago, IL (US))

    1988-04-01

    Fossil fuel process oils consist of such a large number of components that their only proper description is in terms of continuous distribution functions of a suitable characteristic variable. A methodology is presented to describe the oils in terms of a generalized distribution function. The characteristic variable is determined from measurements of the equilibrium ratios of two test oils, at ambient pressure. Application of the proposed methodology to a sequence of operations shows that, unlike the pseudocomponents technique, the level of accuracy can be maintained.

  7. Phase equilibria of continuous fossil fuel process oils

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M.J.; Weil, S.A.

    1987-01-01

    Fossil fuel process oils consist of such a large number of components that their only proper description is in terms of continuous distribution functions of a suitable characteristic variable. A methodology is presented here to describe the oils in terms of a generalized distribution function. The characteristic variable is determined from measurements of the equilibrium ratios of two test oils, at ambient pressure. Application of the proposed methodology to a sequence of operations shows that, unlike the pseudocomponents technique, the level of accuracy can be maintained. 22 refs., 10 figs., 4 tabs.

  8. Phase equilibria of continuous fossil fuel process oils

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M.J.

    1987-01-01

    Fossil fuel processes oils consist of such a large number of components that their only proper description is in terms of continuous distribution functions of a suitable characteristic variable. A methodology is presented here to describe the oils in terms of a generalized distribution function. The characteristic variable is determined from measurements of the equilibrium ratios of two test oils, at ambient pressure. Application of the proposed methodology to a sequence of operations shows that, unlike the psuedocomponents technique, the level of accuracy can be maintained.

  9. Timescales of Massive Human Entrainment

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Perlman, Marcus; Mislove, Alan

    2014-01-01

    of distinct scales, in an exquisitely time locked fashion. Using a large scale database of human communication data, we analyze and describe three different time scales of human entrainment in electronic media. We sought a distinct shared experience that provided a test bed for quantifying large scale human...

  10. Thermochemical Process Development Unit: Researching Fuels from Biomass, Bioenergy Technologies (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2009-01-01

    The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a unique facility dedicated to researching thermochemical processes to produce fuels from biomass.

  11. Microbial fuel cell treatment of ethanol fermentation process water

    Science.gov (United States)

    Borole, Abhijeet P [Knoxville, TN

    2012-06-05

    The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

  12. Process fuel equivalent (PFE)-a new parameter for process and energy audit

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyyu, S.

    1983-04-01

    Process fuel equivalent (PFE) is an energy audit parameter which takes care of all the factors involved in the manufacturing process. In this parameter, all energy items--direct or indirect including those of purchased reagents, fluxes and other raw materials--are converted into a single variable fuel equivalent, and indicated the same in appropriate energy units. PFE value is an inverse order of efficiency--a low value corresponds to high efficiency. In this article, the PFE method has been used for production of copper from mine to wire bar.

  13. Doing Duo – a Case Study of Entrainment in William Forsythe’s Choreography Duo

    OpenAIRE

    Elizabeth eWaterhouse; Riley eWatts; Bläsing, Bettina E.

    2014-01-01

    Entrainment theory focuses on processes in which interacting (i.e. coupled) rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress...

  14. Maximizing the liquid fuel yield in a biorefining process.

    Science.gov (United States)

    Zhang, Bo; von Keitz, Marc; Valentas, Kenneth

    2008-12-01

    Biorefining strives to recover the maximum value from each fraction, at minimum energy cost. In order to seek an unbiased and thorough assessment of the alleged opportunity offered by biomass fuels, the direct conversion of various lignocellulosic biomass was studied: aspen pulp wood (Populus tremuloides), aspen wood pretreated with dilute acid, aspen lignin, aspen logging residues, corn stalk, corn spathe, corn cob, corn stover, corn stover pellet, corn stover pretreated with dilute acid, and lignin extracted from corn stover. Besides the heating rate, the yield of liquid products was found to be dependent on the final liquefaction temperature and the length of liquefaction time. The major compounds of the liquid products from various origins were identified by GC-MS. The lignin was found to be a good candidate for the liquefaction process, and biomass fractionation was necessary to maximize the yield of the liquid bio-fuel. The results suggest a biorefinery process accompanying pretreatment, fermentation to ethanol, liquefaction to bio-crude oil, and other thermo-conversion technologies, such as gasification. Other biorefinery options, including supercritical water gasification and the effectual utilization of the bio-crude oil, are also addressed.

  15. Doing Duo - a case study of entrainment in William Forsythe's choreography "Duo".

    Science.gov (United States)

    Waterhouse, Elizabeth; Watts, Riley; Bläsing, Bettina E

    2014-01-01

    Entrainment theory focuses on processes in which interacting (i.e., coupled) rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress case study of entrainment in William Forsythe's choreography Duo, a duet in which coordinated rhythmic activity is achieved without an external musical beat and without touch-based interaction. Using concepts of entrainment from different disciplines as well as insight from Duo performer Riley Watts, we question definitions of entrainment in the context of dance. The functions of chorusing, turn-taking, complementary action, cues, and alignments are discussed and linked to supporting annotated video material. While Duo challenges the definition of entrainment in dance as coordinated response to an external musical or rhythmic signal, it supports the definition of entrainment as coordinated interplay of motion and sound production by active agents (i.e., dancers) in the field. Agreeing that human entrainment should be studied on multiple levels, we suggest that entrainment between the dancers in Duo is elastic in time and propose how to test this hypothesis empirically. We do not claim that our proposed model of elasticity is applicable to all forms of human entrainment nor to all examples of entrainment in dance. Rather, we suggest studying higher order phase correction (the stabilizing tendency of entrainment) as a potential aspect to be incorporated into other models.

  16. Doing Duo – a Case Study of Entrainment in William Forsythe’s Choreography Duo

    Directory of Open Access Journals (Sweden)

    Elizabeth eWaterhouse

    2014-10-01

    Full Text Available Entrainment theory focuses on processes in which interacting (i.e. coupled rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress case study of entrainment in William Forsythe's choreography Duo, a duet in which coordinated rhythmic activity is achieved without an external musical beat and without touch-based interaction. Using concepts of entrainment from different disciplines as well as insight from Duo performer Riley Watts, we question definitions of entrainment in the context of dance. The functions of chorusing, turn-taking, complementary action, cues and alignments are discussed and linked to supporting annotated video material. While Duo challenges the definition of entrainment in dance as coordinated response to an external musical or rhythmic signal, it supports the definition of entrainment as coordinated interplay of motion and sound production by active agents (i.e., dancers in the field. Agreeing that human entrainment should be studied on multiple levels, we suggest that entrainment between the dancers in Duo is elastic in time and a propose how to test this hypothesis empirically. We do not claim that our proposed model of elasticity is applicable to all forms of human entrainment nor to all to examples of entrainment in dance. Rather, we suggest studying higher order phase correction (the stabilizing tendency of entrainment as a potential aspect to be incorporated into other models.

  17. Turbulence and entrainment length scales in large wind farms.

    Science.gov (United States)

    Andersen, Søren J; Sørensen, Jens N; Mikkelsen, Robert F

    2017-04-13

    A number of large wind farms are modelled using large eddy simulations to elucidate the entrainment process. A reference simulation without turbines and three farm simulations with different degrees of imposed atmospheric turbulence are presented. The entrainment process is assessed using proper orthogonal decomposition, which is employed to detect the largest and most energetic coherent turbulent structures. The dominant length scales responsible for the entrainment process are shown to grow further into the wind farm, but to be limited in extent by the streamwise turbine spacing, which could be taken into account when developing farm layouts. The self-organized motion or large coherent structures also yield high correlations between the power productions of consecutive turbines, which can be exploited through dynamic farm control.This article is part of the themed issue 'Wind energy in complex terrains'.

  18. Fuel Pellets from Biomass. Processing, Bonding, Raw Materials

    DEFF Research Database (Denmark)

    Stelte, Wolfgang

    The depletion of fossil fuels and the need to reduce green house gas emissions has resulted in a strong growth of biomass utilization for heat and power production. Attempts to overcome the poor handling properties of biomass, i.e. its low bulk density and inhomogeneous structure, have resulted...... influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet...... surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding...

  19. Process engineering of ceramic composite coatings for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Kim, H.; Chen, M.; Yang, Q.; Troczynski, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Metals and Materials Engineering

    2003-07-01

    Researchers at UBCeram at the Department of Metals and Materials Engineering at the University of British Columbia have developed a technology to chemically bond composite sol-gel (CB-CSG) coating onto metallic surfaces of complex or concave shapes. The process has been optimized for electrically resistive coatings and corrosion-resistant coatings. The CSG is sprayed onto metallic surfaces and is heat-treated at 300 degrees C to partially dehydrate the hydroxides. The CSG film is then chemically bonded through reaction of active alumina with metal phosphates, such as aluminium phosphate. A new chromate-free process is being developed to address the issue of coatings porosity. The electrodeposition technique involves polymer particles mixed with suspended fine alumina particles which are co-deposited by electrophoretic means or by electrocoagulation. The composite e-coatings have excellent mechanical properties and are being considered as a protective coating for various components of fuel cell systems. 9 refs., 7 figs.

  20. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn [General Electric Global Research, Niskayuna, NY (United States); Subramanian, Ramanathan [General Electric Global Research, Niskayuna, NY (United States); Rizeq, George [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); McDermott, John [General Electric Global Research, Niskayuna, NY (United States); Eiteneer, Boris [General Electric Global Research, Niskayuna, NY (United States); Ladd, David [General Electric Global Research, Niskayuna, NY (United States); Vazquez, Arturo [General Electric Global Research, Niskayuna, NY (United States); Anderson, Denise [General Electric Global Research, Niskayuna, NY (United States); Bates, Noel [General Electric Global Research, Niskayuna, NY (United States)

    2011-12-11

    The U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE's bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation

  1. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

    2011-09-30

    The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE‘s bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and

  2. Preparation and characteristics of nano-crystalline Cu-Ce-Zr-O composite oxides via a green route: supercritical anti-solvent process

    Institute of Scientific and Technical Information of China (English)

    KUANG Li; HUANG Pan; SUN Huanhua; JIANG Haoxi; ZHANG Minhua

    2013-01-01

    The nano-crystalline Cu-Ce-Zr-O composite oxides were successfully prepared by the supercritical anti-solvent (SAS) process.The physicochemical properties and catalytic performances were investigated by X-ray diffraction (XRD),Raman spectroscopy,H2 temperature-programmed reduction (H2-TPR),oxygen storage capacity (OSC) measurement and catalytic activity evaluation.It was found that Cu2+ ions incorporated into CeO2-ZrO2 lattice to forn Cu-Ce-Zr-O solid solution associated with the formation of oxygen vacancies.The Cu-Ce-Zr-O catalysts prepared via the SAS process with the Cu content 2.63 mol.% showed the highest OSC index of 636.9 μmol/g.Compared with the samples prepared by impregnation method,Cu doping using SAS process could improve the dispersion of Cu2+ in the composite oxide,enhance the interaction between Cu2+ and CeO2-ZrO2,improve the reducibility of catalyst,and thus improve the OSC performance and increase the catalytic activity for CO oxidation at low temperature.

  3. Electrochemical processing of spent nuclear fuels: An overview of oxide reduction in pyroprocessing technology

    Directory of Open Access Journals (Sweden)

    Eun-Young Choi

    2015-12-01

    Full Text Available The electrochemical reduction process has been used to reduce spent oxide fuel to a metallic form using pyroprocessing technology for a closed fuel cycle in combination with a metal-fuel fast reactor. In the electrochemical reduction process, oxides fuels are loaded at the cathode basket in molten Li2O–LiCl salt and electrochemically reduced to the metal form. Various approaches based on thermodynamic calculations and experimental studies have been used to understand the electrode reaction and efficiently treat spent fuels. The factors that affect the speed of the electrochemical reduction have been determined to optimize the process and scale-up the electrolysis cell. In addition, demonstrations of the integrated series of processes (electrorefining and salt distillation with the electrochemical reduction have been conducted to realize the oxide fuel cycle. This overview provides insight into the current status of and issues related to the electrochemical processing of spent nuclear fuels.

  4. Integrated microchemical systems for fuel processing in micro fuel cell applications

    Science.gov (United States)

    Pattekar, Ashish V.

    Rapid advances in microelectronics technology over the last decade have led to the search for novel applications of miniaturization to all aspects of engineering. Microreaction engineering, which involves the development of miniature reactors on microchips for novel applications, has been a key area of interest in this quest for miniaturization. The idea of a fully integrated microplant with embedded control electronics, sensors and actuators on a single silicon chip has been gaining increasing acceptance as significant progress is being made in this area. The aim of this project has been to demonstrate a working microreaction system for hydrogen delivery to miniature proton exchange membrane (PEM) fuel cells through the catalytic steam reforming of methanol. The complete reformer - fuel cell unit is proposed as an alternative to conventional portable sources of electricity such as batteries due to its ability to provide an uninterrupted supply of electricity as long as a supply of methanol and water can be provided. This technology also offers significantly higher energy storage densities, which translates into less frequent 'recharging' through the refilling of methanol fuel. Various aspects of the design of a miniature methanol reformer on a silicon substrate are discussed with a focus on the theoretical understanding of microreactor operation and optimum utilization of the semiconductor-processing techniques used for fabricating the devices. Three prototype microreactor designs have been successfully fabricated and tested. Issues related to microchannel capping, on-chip heating and temperature sensing, introduction and trapping of catalyst particles in microchannels, microfluidic interfacing, pressure drop reduction, and thermal insulation have been addressed. Details regarding modeling and simulation of the designs to provide an insight into the working of the microreactor are presented along with a description of the microfabrication steps followed to

  5. A droplet entrainment model for horizontal segregated flows

    Energy Technology Data Exchange (ETDEWEB)

    Höhne, Thomas, E-mail: T.Hoehne@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR) – Institute of Fluid Dynamics, P.O. Box 510119, D-01314 Dresden (Germany); Hänsch, Susann [Imperial College, Department of Mechanical Engineering, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2015-05-15

    Highlights: • We further developed the flow morphology detection model AIAD. • An advanced droplet entrainment model was introduced. • The new approach is applied against HAWAC experiments. - Abstract: One limitation in simulating horizontal segregated flows is that there is no treatment of droplet formation mechanisms at wavy surfaces. For self-generating waves and slugs, the interfacial momentum exchange and the turbulence parameters have to be modeled correctly. Furthermore, understanding the mechanism of droplet entrainment for heat and mass transfer processes is of great importance in the chemical and nuclear industry. The development of general computational fluid dynamics models is an essential precondition for the application of CFD codes to the modeling of flow related phenomena. The new formulation for the interfacial drag at the free surface and turbulence parameters within the algebraic interfacial area density model (AIAD) represents one step toward a more physical description of free surface flows including less empiricism. The AIAD approach allows the use of different physical models depending on the local fluid morphology inside a macro-scale multi-fluid framework. A further step of improving the modeling of free interfaces lies within the consideration of droplet entrainment mechanisms. In this paper a new sub-grid entrainment model is proposed, which assumes that due to liquid turbulence the interface gets rough and wavy leading to the formation of droplets. Therefore, the droplet entrainment model requires the consideration of an additional droplet phase, which is described with an own set of balance equations in the spirit of the particle model. Two local key factors determine the rate of droplet entrainment: the liquid turbulent kinetic energy as well as the outward velocity gradient of the liquid relative to the interface motion. The new droplet entrainment approach is included into CFD simulations for attempting to reproduce existing

  6. Interaction behavior between binary xCe-yNd alloy and HT9

    Science.gov (United States)

    Kim, Jun Hwan; Cheon, Jin Sik; Lee, Byoung Oon; Kim, June Hyung

    2016-10-01

    Studies were carried out to investigate the role of Ce and Nd, contained inside metal fuel during reactor operation, and their effect on the Fuel-Cladding Chemical Interaction (FCCI) phenomenon, which limits fuel performance in the Sodium-cooled Fast Reactor (SFR). Binary model alloys of xCe-yNd were manufactured, and then diffusion couple tests with HT9 (12Cr-1MoWV) ferritic-martensitic cladding material were carried out at a temperature of 660 °C for up to 25 h. The results showed that both Ce and Nd reacted with Fe in the cladding material to form an interaction layer. Analysis of the microstructure and reaction kinetics revealed that Fe in the cladding material rapidly migrates into Ce to form eutectic reaction, leaving a Fe depleted zone, in which Ce substitutes. In the case of Nd element, a typical solid-solid diffusion process governed to form a Fe17Nd2 type intermetallic compound. Synergism between Ce and Nd occurred so that the reaction thickness was increased, reaching the maximum reaction thickness in the case of the xCe-yNd alloy, whose composition was nearly 1:1.

  7. Laser-based analytical monitoring in nuclear-fuel processing plants

    Energy Technology Data Exchange (ETDEWEB)

    Hohimer, J.P.

    1978-09-01

    The use of laser-based analytical methods in nuclear-fuel processing plants is considered. The species and locations for accountability, process control, and effluent control measurements in the Coprocessing, Thorex, and reference Purex fuel processing operations are identified and the conventional analytical methods used for these measurements are summarized. The laser analytical methods based upon Raman, absorption, fluorescence, and nonlinear spectroscopy are reviewed and evaluated for their use in fuel processing plants. After a comparison of the capabilities of the laser-based and conventional analytical methods, the promising areas of application of the laser-based methods in fuel processing plants are identified.

  8. Process for dehydration of oregano using propane gas as fuel

    Directory of Open Access Journals (Sweden)

    Carlos O. Velásquez-Santos

    2014-08-01

    Full Text Available The article describes two important issues, the first is the process to design, implement and validate a mechanical dryer of oregano, using propane gas as fuel, and the second is the cost of the process of dehydrated, taking into account the cost of electric energy consumption by the fan and the cost of propane gas consumption by the heat exchanger. To achieve this, it was necessary review the state of the art and the study of the raw material (oregano, were established as premises of design the necessary technical specifications and the variables involved in the process, using conceptual methods and simulation to ensure that it complies with the ISO standard 7925:1999, which defines the requirements for the marketing of dried oregano and processed. Emphasis was made on the percentage of moisture that is 10%, the moisture of the product was found by the azeotropic distillation method, subsequently was validated the functionality and efficiency, comparing the results from an experimental design, then it was obtained the drying curve of oregano with the prototype of drying and it was checked if it meets ISO 7925:1999 standard and the NTC 4423 standard in order to obtain a final product dehydrated with the percentage of humidity appropriate.

  9. Selective CO methanation catalysts for fuel processing applications

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Wang, Yong; Xia, Guan-Guang; Strohm, James J.; Holladay, Jamelyn [Pacific Northwest National Laboratory, 902 Battle Boulevard, P.O. Box 999, Richland, WA 99352 (United States); Palo, Daniel R. [Pacific Northwest National Laboratory, 902 Battle Boulevard, P.O. Box 999, Richland, WA 99352 (United States); Microproducts Breakthrough Institute, P.O. Box 2330, Corvallis, OR 97339 (United States)

    2007-07-15

    Selective CO methanation as a strategy for CO removal in fuel processing applications was investigated over Ru-based catalysts. Ru metal loading and crystallite size were shown to affect catalyst activity and selectivity. Even operating at a gas-hourly-space-velocity as high as 13,500 h{sup -1}, a 3% Ru/Al{sub 2}O{sub 3} catalyst with a 34.2 nm crystallite was shown to be capable of reducing CO in a reformate to less than 100 ppm over a wide temperature range from 240 to 280 C, while keeping hydrogen consumption below 10%. We present the effects of metal loading, preparation method, and crystallite size on performance for Ru-based catalysts in the selective methanation of CO in the presence of H{sub 2} and CO{sub 2}. (author)

  10. Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    E.T. (Skip) Robinson; James P. Meagher; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Siv Aasland; Charles Besecker; Jack Chen Bart A. van Hassel; Olga Polevaya; Rafey Khan; Piyush Pilaniwalla

    2002-12-31

    This topical report summarizes work accomplished for the Program from November 1, 2001 to December 31, 2002 in the following task areas: Task 1: Materials Development; Task 2: Composite Development; Task 4: Reactor Design and Process Optimization; Task 8: Fuels and Engine Testing; 8.1 International Diesel Engine Program; 8.2 Nuvera Fuel Cell Program; and Task 10: Program Management. Major progress has been made towards developing high temperature, high performance, robust, oxygen transport elements. In addition, a novel reactor design has been proposed that co-produces hydrogen, lowers cost and improves system operability. Fuel and engine testing is progressing well, but was delayed somewhat due to the hiatus in program funding in 2002. The Nuvera fuel cell portion of the program was completed on schedule and delivered promising results regarding low emission fuels for transportation fuel cells. The evaluation of ultra-clean diesel fuels continues in single cylinder (SCTE) and multiple cylinder (MCTE) test rigs at International Truck and Engine. FT diesel and a BP oxygenate showed significant emissions reductions in comparison to baseline petroleum diesel fuels. Overall through the end of 2002 the program remains under budget, but behind schedule in some areas.

  11. Thermal measurements and computational simulations of three-phase (CeO2-MgAl2O4-CeMgAl11O19) and four-phase (3Y-TZP-Al2O3-MgAl2O4-LaPO4) composites as surrogate inert matrix nuclear fuel

    Science.gov (United States)

    Angle, Jesse P.; Nelson, Andrew T.; Men, Danju; Mecartney, Martha L.

    2014-11-01

    This study investigates the temperature dependent thermal conductivity of multiphase ceramic composites for simulated inert matrix nuclear fuel. Fine grained composites were made of CeO2-MgAl2O4-CeMgAl11O19 or 3Y-TZP-Al2O3-MgAl2O4-LaPO4. CeO2 and 3Y-TZP are used as UO2 surrogates due to their similar structures and low thermal conductivities. Laser flash analysis from room temperature to 1273 K (1000 °C) was used to determine the temperature dependent thermal conductivity. A computational approach using Object Oriented Finite Element Analysis Version 2 (OOF2) was employed to simulate the composite thermal conductivity based on the microstructure. Observed discrepancies between experimental and simulated thermal conductivities at low temperature may be due to Kapitza resistance; however, there is less than 3% deviation between models and experiments above 673 K (400 °C) for both compositions. When the surrogate phase was replaced with UO2 in the computational model for the four-phase composite, a 12-16% increase in thermal conductivity resulted compared to single phase UO2, in the range of 673-1273 K (400-1000 °C). This computational approach may be potentially viable for the high-throughput evaluation of composite systems and the strategic selection of inert phases without extensive sample fabrication during the initial development stages of composite nuclear fuel design.

  12. Refuse-derived fuels: Provision and processing; Schnittstelle und Aufbereitungstiefe von Ersatzbrennstoffen fuer die energetische Verwertung

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, M.; Horeni, M. [Bauhaus Univ. Weimar (Germany). Professur Verfahren und Umwelt; Scholz, R. [Technische Univ. Clausthal (Germany). Inst. fuer Energieverfahrenstechnik und Brennstofftechnik

    2005-07-01

    Refuse-derived fuels are produced by mechanical or mechanical and biological treatment of waste materials with the intention of providing substitute fuels for the chemical and power plant industry. To do this, the properties of refues-derived fuels must be known as well as the process modifications that may be required. Further, energy and pollutant balances (including CO2) must be established in order to find out about the economic efficiency of the substitute fuels. There is still need for research concerning the methodology of characterisation and the classification of substitute fuels. The contribution starts by presenting a classification of substitute fuels, their applications and potentials. This is followed by a description of the characteristics of substitute fuels and the process optimisations required. Using simplified model assumptions, the results are then discussed with regard to the influence of the depth of processing. Finally, development tasks still required are summarized. (orig.)

  13. Auditory cortical delta-entrainment interacts with oscillatory power in multiple fronto-parietal networks.

    Science.gov (United States)

    Keitel, Anne; Ince, Robin A A; Gross, Joachim; Kayser, Christoph

    2017-02-15

    The timing of slow auditory cortical activity aligns to the rhythmic fluctuations in speech. This entrainment is considered to be a marker of the prosodic and syllabic encoding of speech, and has been shown to correlate with intelligibility. Yet, whether and how auditory cortical entrainment is influenced by the activity in other speech-relevant areas remains unknown. Using source-localized MEG data, we quantified the dependency of auditory entrainment on the state of oscillatory activity in fronto-parietal regions. We found that delta band entrainment interacted with the oscillatory activity in three distinct networks. First, entrainment in the left anterior superior temporal gyrus (STG) was modulated by beta power in orbitofrontal areas, possibly reflecting predictive top-down modulations of auditory encoding. Second, entrainment in the left Heschl's Gyrus and anterior STG was dependent on alpha power in central areas, in line with the importance of motor structures for phonological analysis. And third, entrainment in the right posterior STG modulated theta power in parietal areas, consistent with the engagement of semantic memory. These results illustrate the topographical network interactions of auditory delta entrainment and reveal distinct cross-frequency mechanisms by which entrainment can interact with different cognitive processes underlying speech perception.

  14. On robustness of phase resetting to cell division under entrainment.

    Science.gov (United States)

    Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis

    2015-12-21

    The problem of phase synchronization for a population of genetic oscillators (circadian clocks, synthetic oscillators, etc.) is considered in this paper, taking into account a cell division process and a common entrainment input in the population. The proposed analysis approach is based on the Phase Response Curve (PRC) model of an oscillator (the first order reduced model obtained for the linearized system and inputs with infinitesimal amplitude). The occurrence of cell division introduces state resetting in the model, placing it in the class of hybrid systems. It is shown that without common entraining input in all oscillators, the cell division acts as a disturbance causing phase drift, while the presence of entrainment guarantees boundedness of synchronization phase errors in the population. The performance of the obtained solutions is demonstrated via computer experiments for two different models of circadian/genetic oscillators (Neurospora׳s circadian oscillation model and the repressilator).

  15. Process modeling of fuel cell vehicle power system

    Institute of Scientific and Technical Information of China (English)

    CHEN LiMing; LIN ZhaoJia; MA ZiFeng

    2009-01-01

    Constructed here is a mathematic model of PEM Fuel Cell Vehicle Power System which is composed of fuel supply model, fuel cell stack model and water-heat management model. The model was developed by Matiab/Simulink to evaluate how the major operating variables affect the output performances. Itshows that the constructed model can represent characteristics of the power system closely by comparing modeling results with experimental data, and it can be used in the study and design of fuel cell vehicle power system.

  16. Fuel Quality/Processing Study. Volume II. Appendix, Task I, literature survey

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, J B; Bela, A; Jentz, N E; Klumpe, H W; Kessler, R E; Kotzot, H T; Loran, B I

    1981-04-01

    This activity was begun with the assembly of information from Parsons' files and from contacts in the development and commercial fields. A further more extensive literature search was carried out using the Energy Data Base and the American Petroleum Institute Data Base. These are part of the DOE/RECON system. Approximately 6000 references and abstracts were obtained from the EDB search. These were reviewed and the especially pertinent documents, approximately 300, were acquired in the form of paper copy or microfiche. A Fuel Properties form was developed for listing information pertinent to gas turbine liquid fuel properties specifications. Fuel properties data for liquid fuels from selected synfuel processes, deemed to be successful candidates for near future commercial plants were tabulated on the forms. The processes selected consisted of H-Coal, SRC-II and Exxon Donor Solvent (EDS) coal liquefaction processes plus Paraho and Tosco shale oil processes. Fuel properties analyses for crude and distillate syncrude process products are contained in Section 2. Analyses representing synthetic fuels given refinery treatments, mostly bench scale hydrotreating, are contained in Section 3. Section 4 discusses gas turbine fuel specifications based on petroleum source fuels as developed by the major gas turbine manufacturers. Section 5 presents the on-site gas turbine fuel treatments applicable to petroleum base fuels impurities content in order to prevent adverse contaminant effects. Section 7 relates the environmental aspects of gas turbine fuel usage and combustion performance. It appears that the near future stationary industrial gas turbine fuel market will require that some of the synthetic fuels be refined to the point that they resemble petroleum based fuels.

  17. Fossil-fuel process oils as continuous fluids

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian-Amin, M.J.

    1986-01-01

    The oils produced by fossil fuel conversion processes consist of such a large number of components that their only proper description is as continuous fluids (i.e., continuum of components). A methodology is presented here to describe the vapor liquid equilibrium processes involving continuous oils. It describes the oil in terms of one or more continuous distribution functions (fractional continuous oils) of some measurable quantity (i.e., characteristic variable) that, in the view of the equilibrium ratio relationship, maintain their functional form in equilibrium processes. Parameters of the distributions of the product streams in any equilibrium process (i.e., vapor and liquid) are determined in terms of the parameters of the feed stream and the operating condition (e.g., T,P). In general, the procedure can be applied to both ideal and non-ideal systems, but in view of the experimental results indicating ideality, only those systems were analyzed. An ambient pressure batch distillation system was constructed to collect vapor-liquid equilibrium data of continuous test oils. Two test oils, a shale oil and a coal oil were studied in this work. From measurement of the equilibrium ratios of the test oils it was determined that both oils behave ideally and the equilibrium ratio was independent of the liquid composition. A simple and definable function of the boiling point provided to be a suitable characteristic variable for the proposed methodology to the sequential operation has shown that if the functions are chosen properly, then the error incurred will not propagate at a significant rate and at the same level of accuracy can be maintained.

  18. Fate of virginiamycin through the fuel ethanol production process.

    Science.gov (United States)

    Bischoff, Kenneth M; Zhang, Yanhong; Rich, Joseph O

    2016-05-01

    Antibiotics are frequently used to prevent and treat bacterial contamination of commercial fuel ethanol fermentations, but there is concern that antibiotic residues may persist in the distillers grains coproducts. A study to evaluate the fate of virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research Center, Edwardsville, IL. Three 15,000-liter fermentor runs were performed: one with no antibiotic (F1), one dosed with 2 parts per million (ppm) of a commercial virginiamycin product (F2), and one dosed at 20 ppm of virginiamycin product (F3). Fermentor samples, distillers dried grains with solubles (DDGS), and process intermediates (whole stillage, thin stillage, syrup, and wet cake) were collected from each run and analyzed for virginiamycin M and virginiamycin S using a liquid chromatography-mass spectrometry method. Virginiamycin M was detected in all process intermediates of the F3 run. On a dry-weight basis, virginiamycin M concentrations decreased approximately 97 %, from 41 μg/g in the fermentor to 1.4 μg/g in the DDGS. Using a disc plate bioassay, antibiotic activity was detected in DDGS from both the F2 and F3 runs, with values of 0.69 μg virginiamycin equivalent/g sample and 8.9 μg/g, respectively. No antibiotic activity (<0.6 μg/g) was detected in any of the F1 samples or in the fermentor and process intermediate samples from the F2 run. These results demonstrate that low concentrations of biologically active antibiotic may persist in distillers grains coproducts produced from fermentations treated with virginiamycin.

  19. Batch Extractive Distillation with Light Entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol/water (minimum boiling azeotrope) with methanol, water/ethylene diamine (maximum boiling azeotro...

  20. Batch extractive distillation with light entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Lelkes, Zoltan; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol / water (minimum boiling azeotrope) with methanol, water / ethylene diamine (maximum boiling azeotrope...

  1. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    Energy Technology Data Exchange (ETDEWEB)

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in

  2. Advanced Diagnostics in Oxy-Fuel Combustion Processes

    DEFF Research Database (Denmark)

    Brix, Jacob; Toftegaard, Maja Bøg; Clausen, Sønnik

    , formed the basis of a publication and it is part of two PhD dissertations. The name of the conference the journal and the dissertations are listed below. - Joint Meeting of the Scandinavian-Nordic and French Sections of the Combustion Institute, Combustion of Char Particles under Oxy-Fuel Conditions......: Formation of NO and Particle Temperature, Copenhagen, 9-10 November 2009. - Brix J, Navascués LG, Joachim, Nielsen JB, Bonnek PL, Larsen HE, Clausen S, Glarborg P, Jensen AD, Oxy-Fuel Combustion of Coal Char: Particle Temperature and NO Formation, Submitted to Fuel on the 19th of November 2010. - Brix J......, Oxy-Fuel Combustion of Coal, Ph.D. Thesis, CHEC Research Centre – Technical University of Denmark, 2011. - Toftegaard, MB, OxyFuel Combustion of Coal and Biomass, Ph.D. Thesis, CHEC Research Centre – Technical University of Denmark, 2011. In addition two students projects have been carried out...

  3. Historic American Engineering Record, Idaho National Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex

    Energy Technology Data Exchange (ETDEWEB)

    Susan Stacy; Julie Braun

    2006-12-01

    Just as automobiles need fuel to operate, so do nuclear reactors. When fossil fuels such as gasoline are burned to power an automobile, they are consumed immediately and nearly completely in the process. When the fuel is gone, energy production stops. Nuclear reactors are incapable of achieving this near complete burn-up because as the fuel (uranium) that powers them is burned through the process of nuclear fission, a variety of other elements are also created and become intimately associated with the uranium. Because they absorb neutrons, which energize the fission process, these accumulating fission products eventually poison the fuel by stopping the production of energy from it. The fission products may also damage the structural integrity of the fuel elements. Even though the uranium fuel is still present, sometimes in significant quantities, it is unburnable and will not power a reactor unless it is separated from the neutron-absorbing fission products by a method called fuel reprocessing. Construction of the Fuel Reprocessing Complex at the Chem Plant started in 1950 with the Bechtel Corporation serving as construction contractor and American Cyanamid Company as operating contractor. Although the Foster Wheeler Corporation assumed responsibility for the detailed working design of the overall plant, scientists at Oak Ridge designed all of the equipment that would be employed in the uranium separations process. After three years of construction activity and extensive testing, the plant was ready to handle its first load of irradiated fuel.

  4. CeO2-Y2O3-ZrO2 Membrane with Enhanced Molten Salt Corrosion Resistance for Solid Oxide Membrane (SOM) Electrolysis Process

    Science.gov (United States)

    Zou, Xingli; Li, Xin; Shen, Bin; Lu, Xionggang; Xu, Qian; Zhou, Zhongfu; Ding, Weizhong

    2017-02-01

    Innovative CeO2-Y2O3-ZrO2 membrane has been successfully developed and used in the solid oxide membrane (SOM) electrolysis process for green metallic materials production. The x mol pct ceria/(8- x) mol pct yttria-costabilized zirconia ( xCe(8- x)YSZ, x = 0, 1, 4, or 7) membranes have been fabricated and investigated as the membrane-based inert anodes to control the SOM electroreduction process in molten salt. The characteristics of these fabricated xCe(8- x)YSZ membranes including their corrosion resistances in molten salt and their degradation mechanisms have been systematically investigated and compared. The results show that the addition of ceria in the YSZ-based membrane can inhibit the depletion of yttrium during the SOM electrolysis, which thus makes the ceria-reinforced YSZ-based membranes possess enhanced corrosion resistances to molten salt. The ceria/yttria-costabilized zirconia membranes can also provide reasonable oxygen ion conductivity during electrolysis. Further investigation shows that the newly modified 4Ce4YSZ ceramic membrane has the potential to be used as novel inert SOM anode for the facile and sustainable production of metals/alloys/composites materials such as Si, Ti5Si3, TiC, and Ti5Si3/TiC from their metal oxides precursors in molten CaCl2.

  5. CeO2-Y2O3-ZrO2 Membrane with Enhanced Molten Salt Corrosion Resistance for Solid Oxide Membrane (SOM) Electrolysis Process

    Science.gov (United States)

    Zou, Xingli; Li, Xin; Shen, Bin; Lu, Xionggang; Xu, Qian; Zhou, Zhongfu; Ding, Weizhong

    2016-10-01

    Innovative CeO2-Y2O3-ZrO2 membrane has been successfully developed and used in the solid oxide membrane (SOM) electrolysis process for green metallic materials production. The x mol pct ceria/(8-x) mol pct yttria-costabilized zirconia (xCe(8-x)YSZ, x = 0, 1, 4, or 7) membranes have been fabricated and investigated as the membrane-based inert anodes to control the SOM electroreduction process in molten salt. The characteristics of these fabricated xCe(8-x)YSZ membranes including their corrosion resistances in molten salt and their degradation mechanisms have been systematically investigated and compared. The results show that the addition of ceria in the YSZ-based membrane can inhibit the depletion of yttrium during the SOM electrolysis, which thus makes the ceria-reinforced YSZ-based membranes possess enhanced corrosion resistances to molten salt. The ceria/yttria-costabilized zirconia membranes can also provide reasonable oxygen ion conductivity during electrolysis. Further investigation shows that the newly modified 4Ce4YSZ ceramic membrane has the potential to be used as novel inert SOM anode for the facile and sustainable production of metals/alloys/composites materials such as Si, Ti5Si3, TiC, and Ti5Si3/TiC from their metal oxides precursors in molten CaCl2.

  6. Dissolution of Ce from Cd Solution Containing U/Ce Elements by Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Hyung; Kim, Gha-Young; Lee, Seung-jai; Kim, Taek-Jin; Paek, Seungwoo; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The U-TRU metal alloy can be supplied by the Pyroprocessing, specifically UTRU recovery process using liquid cadmium cathode (LCC). In a certain case, a lot of rare earth (RE) element could be recovered on the LCC with the TRU element during the Pyroprocessing when the concentration of RE ions is higher than that of the TRU ions in the salt. In this case, most of the RE element needs to be removed from the Cd solution containing U/TRU/RE elements. RAR(Residual Actinides Recovery) technique used the mixed electrolytic-chemical process. In this study, only electrolysis technique was utilized to remove Ce element from Cd solution containing U/Ce elements. U-TRU alloy having less impurity is necessary for the fabrication of SFR fuel and these U-TRU elements can be prepared by Pyroprocessing. Electrolytic method was used to reduce the amount of Ce elements from the Cd solution containing U/Ce elements. It is judged from this study that electrolytic dissolution can be one of the methods to reduce RE elements from the Cd solution containing U-TRU-RE elements.

  7. Carbon stripping - a critical process step in chemical looping combustion of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kramp, M.; Thon, A.; Hartge, E.U.; Heinrich, S.; Werther, J. [Hamburg University of Technology, Institute of Solids Process Engineering and Particle Technology, Hamburg (Germany)

    2012-03-15

    In chemical looping combustion of solid fuels the well-mixed solids flow from the fuel reactor consisting of char, ash, and oxygen carrier particles cannot be completely separated into its constituents before it enters the air reactor. The slip of carbon will thus lead to char oxidation in the wrong reactor. Process simulation was applied to investigate the carbon stripping process in chemical looping combustion of solid fuels. Depending on the fuel choice, without carbon stripping CO{sub 2} capture rates below 50 % are calculated for 4 min of solids residence time in the fuel reactor. In a process with carbon stripper, however, CO{sub 2} capture rates exceeding 90 % can be achieved for both fuels investigated in this work. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Heterogeneous catalytic process for alcohol fuels from syngas

    Energy Technology Data Exchange (ETDEWEB)

    Minahan, D.M.; Nagaki, D.A.

    1995-12-31

    This project is focused on the discovery and evaluation of novel heterogeneous catalyst for the production of oxygenated fuel enhancers from synthesis gas. Catalysts have been studied and optimized for the production of methanol and isobutanol mixtures which may be used for the downstream synthesis of MTBE or related oxygenates. Higher alcohols synthesis (HAS) from syngas was studied; the alcohols that are produced in this process may be used for the downstream synthesis of MTBE or related oxygenates. This work has resulted in the discovery of a catalyst system that is highly selective for isobutanol compared with the prior art. The catalysts operate at high temperature (400{degrees}C), and consist of a spinel oxide support (general formula AB{sub 2}O{sub 4}, where A=M{sup 2+} and B = M{sup 3+}), promoted with various other elements. These catalysts operate by what is believed to be an aldol condensation mechanism, giving a product mix of mainly methanol and isobutanol. In this study, the effect of product feed/recycle (methanol, ethanol. n-propanol, isopropanol, carbon dioxide and water) on the performance of 10-DAN-55 (spinel oxide based catalyst) at 400{degrees}C, 1000 psi, GHSV = 12,000 and syngas (H{sub 2}/CO) ratio = 1:2 (alcohol addition) and 1:1 (carbon dioxide and water addition) was studied. The effect of operation at high temperatures and pressures on the performance of an improved catalyst formulation was also examined.

  9. Transcriptome Changes in Douglas-fir (Pseudotsuga menziesii) Induced by Exposure to Diesel Emissions Generated with CeO2 Nanoparticle Fuel Additive

    Science.gov (United States)

    When cerium oxide nanoparticles are added to diesel fuel, fuel burning efficiency increases, producing emissions (DECe) with characteristics that differ from conventional diesel exhaust (DE). It has previously been shown that DECe induces more adverse pulmonary effects in rats on...

  10. Nongray-gas Effects in Modeling of Large-scale Oxy-fuel Combustion Processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    , among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a large-scale utility boiler is numerically investigated......, the gray calculation of the oxy-fuel WSGGM remarkably over-predicts the radiative heat transfer to the furnace walls and under-predicts the gas temperature at the furnace exit plane, which also result in a higher incomplete combustion in the gray calculation. Moreover, the gray and non-gray calculations......Quite some studies have been conducted in order to implement oxy-fuel combustion with flue gas recycle in conventional utility boilers as an effective effort of carbon capture and storage. However, combustion under oxy-fuel conditions is significantly different from conventional air-fuel firing...

  11. Properties of Aluminum Deposited by a High-Velocity Oxygen-Fueled Process

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R; Decker, T A; Gansert, R V; Gansert, D; Lee, D

    2001-06-12

    Aluminum coatings deposited by a HVOF process have been demonstrated and relevant coating properties evaluated according to two deposition parameters, the spray distance and the oxygen-to-fuel flow ratio. The coating porosity, surface roughness, and microhardness are measured. The coating properties are fairly insensitive to spray distance, the distance between the nozzle and the workpiece, and fuel ratios, the oxygen-to-fuel flow. Increasing the fuel content does appear to improve the process productivity in terms of surface roughness. Minimization of nozzle loading is discussed.

  12. Rocket Fuel Synthesis by Fisher-Tropsch Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — While In-Situ Resource Utilization (ISRU) studies for Mars return have emphasized methane fuel, only modest work has been done to develop the methane-powered rocket...

  13. Synchronization and entrainment of coupled circadian oscillators

    CERN Document Server

    Komin, Niko; Hernandez-Garcia, Emilio; Toral, Raul

    2010-01-01

    Circadian rhythms in mammals are controlled by the neurons located in the suprachiasmatic nucleus of the hypothalamus. In physiological conditions, the system of neurons is very efficiently entrained by the 24-hour light-dark cycle. Most of the studies carried out so far emphasize the crucial role of the periodicity imposed by the light dark cycle in neuronal synchronization. Nevertheless, heterogeneity as a natural and permanent ingredient of these cellular interactions is seemingly to play a major role in these biochemical processes. In this paper we use a model that considers the neurons of the suprachiasmatic nucleus as chemically-coupled modified Goodwin oscillators, and introduce non-negligible heterogeneity in the periods of all neurons in the form of quenched noise. The system response to the light-dark cycle periodicity is studied as a function of the interneuronal coupling strength, external forcing amplitude and neuronal heterogeneity. Our results indicate that the right amount of heterogeneity hel...

  14. Effects of Ce and Sb on the microstructure and properties of AZ91D magnesium alloy prepared by the EPC process

    Institute of Scientific and Technical Information of China (English)

    LI Jiqiang; DONG Xuanpu; FAN Zitian; WANG Yuanqing

    2008-01-01

    The effects of small amounts of cerium and antimony additions on the microstructure and the mechanical properties of AZ91D (Mg-9A1-Zn)based alloy were researched via the expendable pattern casting (EPC) process.The results show that the microstructure is obviously refined and the tensile strength of the AZ91D based alloy at ambient temperature is significantly improved.When compared to AZ91D,the AZ91D-1.0%Ce-0.4%Sb alloy has higher ultimate tensile strength and elongation.Its ultimate tensile strength and elongation are enhanced by 39% and 47%,respectively.The morphology of the tensile fracture of the AZ91D-1.0%Ce-0.4%Sb alloy has more characteristics of quasi-cleavage,This indicates that it has had a larger plastic deformation before failure.The tensile strength and elongation decrease with the increase of Ce and Sb contents because of the coarsening and volume increase of Cesb and Al11Ce3 phases.

  15. Improved activity and stability of Ni-Ce0.8Sm0.2O1.9 anode for solid oxide fuel cells fed with methanol through addition of molybdenum

    Science.gov (United States)

    Li, Ping; Yu, Baolong; Li, Jiang; Yao, Xueli; Zhao, Yicheng; Li, Yongdan

    2016-07-01

    Ni-Mo-Ce0.8Sm0.2O1.9 (SDC) composites are prepared and investigated as anodes of solid oxide fuel cells with methanol as fuel. The addition of Mo improves the catalytic activity for methanol pyrolysis and the resistance to carbon deposition of Ni-SDC anode. The anode with a mole ratio of Mo to Ni of 0.03:1 exhibits the lowest polarization resistance. The cell with that anode and SDC-carbonate composite electrolyte shows a maximum power density of 680 mW cm-2 at 700 °C. The stability of the cell is enhanced with the increase of the content of Mo in the anode, which is mainly attributed to the decreased amount of carbon deposits with a high graphitization degree.

  16. Technical and economic feasibility of alternative fuel use in process heaters and small boilers

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    The technical and economic feasibility of using alternate fuels - fuels other than oil and natural gas - in combustors not regulated by the Powerplant and Industrial Fuel Use Act of 1978 (FUA) was evaluated. FUA requires coal or alternate fuel use in most large new boilers and in some existing boilers. Section 747 of FUA authorizes a study of the potential for reduced oil and gas use in combustors not subject to the act: small industrial boilers with capacities less than 100 MMBtu/hr, and process heat applications. Alternative fuel use in combustors not regulated by FUA was examined and the impact of several measures to encourage the substitution of alternative fuels in these combustors was analyzed. The primary processes in which significant fuel savings can be achieved are identified. Since feedstock uses of oil and natural gas are considered raw materials, not fuels, feedstock applications are not examined in this analysis. The combustors evaluated in this study comprise approximately 45% of the fuel demand projected in 1990. These uses would account for more than 3.5 million barrels per day equivalent fuel demand in 1990.

  17. An entrainment model for fluid mud

    NARCIS (Netherlands)

    Kranenburg, C.

    1993-01-01

    An entrainment model for fluid mud is derived by integrating the equation for turbulent kinetic energy across the mixed layer and introducing some modelling assumptions. The resulting entrainment model is similar to models of mixed-layer deepening in lakes and reservoirs, but in addition accounts fo

  18. Using circadian entrainment to find cryptic clocks

    NARCIS (Netherlands)

    Eelderink-Chen, Zheng; Olmedo, Maria; Bosman, Jasper; Merrow, Martha

    2015-01-01

    Three properties are most often attributed to the circadian clock: a ca. 24-h free-running rhythm, temperature compensation of the circadian rhythm, and its entrainment to zeitgeber cycles. Relatively few experiments, however, are performed under entrainment conditions. Rather, most chronobiology pr

  19. Fundamental Investigation of Jet Fuel Spray and Ignition Process in an Optically Accessible Piston Engine

    Science.gov (United States)

    2015-01-16

    design of Almy engines . Tests were perf01med using #2 diesel fuel, jet fuel (JP8), and a hydroprocessed renewable jet fuel (HRJ). Ambient the1modynamic...1+~ .,:-•. ~-~ ~~~~·~~· · -~ ~- --~~ 1S. SUBJECT TERMS Transient, diesel , injection, optical engine 16. SECURITY...injection process in small bore diesel engines . (a) Papers published in peer-reviewed journals (N/A for none) Enter List of papers submitted or

  20. Optimizing photo-Fenton like process for the removal of diesel fuel from the aqueous phase

    OpenAIRE

    Dehghani, Mansooreh; Shahsavani, Esmaeel; Farzadkia, Mahdi; Samaei, Mohammad Reza

    2014-01-01

    Background In recent years, pollution of soil and groundwater caused by fuel leakage from old underground storage tanks, oil extraction process, refineries, fuel distribution terminals, improper disposal and also spills during transferring has been reported. Diesel fuel has created many problems for water resources. The main objectives of this research were focused on assessing the feasibility of using photo-Fenton like method using nano zero-valent iron (nZVI/UV/H2O2) in removing total petro...

  1. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    concentration, larger feeder gas flow, and longer residence time. Wood, straw, and lignin had similar gasification behavior except with regard to soot formation. The soot yield was lowest during straw gasification possibly because of its high potassium content. The equilibrium product compositions under...... from straw gasification had quite low content of soot while high contents of volatilizable KCl and K2SO4, and thereby appeared as irregular crystals (> 100 nm). During lignin gasification, the filter sample mainly consisted of soot and nonvolatilizable inorganic matter. The parent wood particles...... the wood soot with respect to both oxidation and CO2 gasification. Besides, the wood soot produced at higher temperature was more reactive than the soot produced at lower temperature. Biomass and coal co-gasification experiments were performed in the same entrained flow reactor. The effect of mixing ratio...

  2. Integration and testing of hot desulfurization and entrained-flow gasification for power generation systems. Phase 2, Process optimization: Volume 1, Program summary and PDU operations

    Energy Technology Data Exchange (ETDEWEB)

    Robin, A.M.; Kassman, J.S.; Leininger, T.F.; Wolfenbarger, J.K.; Wu, C.M.; Yang, P.P.

    1991-09-01

    This second Topical Report describes the work that was completed between January 1, 1989 and December 31, 1990 in a Cooperative Agreement between Texaco and the US Department of Energy that began on September 30, 1987. During the period that is covered in this report, the development and optimization of in-situ and external desulfurization processes were pursued. The research effort included bench scale testing, PDU scoping tests, process economic studies and advanced instrument testing. Two bench scale studies were performed at the Research Triangle Institute with zinc titanate sorbent to obtain data on its cycle life, sulfur capacity, durability and the effect of chlorides. These studies quantify sulfur capture during simulated air and oxygen-blown gasification for two zinc titanate formulations. Eight PDU runs for a total of 20 days of operation were conducted to evaluate the performance of candidate sorbents for both in-situ and external desulfurization. A total of 47 tests were completed with oxygen and air-blown gasification. Candidate sorbents included iron oxide for in-situ desulfurization and calcium based and mixed metal oxides for external desulfurization. Gasifier performance and sorbent sulfur capture are compared for both air-blown and oxygen-blown operation.

  3. (La, Pr)0.8Sr0.2FeO3-δ-Sm 0.2Ce0.8O2-δ composite cathode for proton-conducting solid oxide fuel cells

    KAUST Repository

    Chen, Yonghong

    2014-08-01

    Mixed rare-earth (La, Pr)0.8Sr0.2FeO 3-δ-Sm0.2Ce0.8O2-δ (LPSF-SDC) composite cathode was investigated for proton-conducting solid oxide fuel cells based on protonic BaZr0.1Ce0.7Y 0.2O3-δ (BZCY) electrolyte. The powders of La 0.8-xPrxSr0.2FeO3-δ (x = 0, 0.2, 0.4, 0.6), Sm0.2Ce0.8O2-δ (SDC) and BaZr0.1Ce0.7Y0.2O3-δ (BZCY) were synthesized by a citric acid-nitrates self-propagating combustion method. The XRD results indicate that La0.8-xPrxSr 0.2FeO3-δ samples calcined at 950 °C exhibit perovskite structure and there are no interactions between LPSF0.2 and SDC at 1100 °C. The average thermal expansion coefficient (TEC) of LPSF0.2-SDC, BZCY and NiO-BZCY is 12.50 × 10-6 K-1, 13.51 × 10-6 K-1 and 13.47 × 10-6 K -1, respectively, which can provide good thermal compatibility between electrodes and electrolyte. An anode-supported single cell of NiO-BZCY|BZCY|LPSF0.2-SDC was successfully fabricated and operated from 700 °C to 550 °C with humidified hydrogen (∼3% H2O) as fuel and the static air as oxidant. A high maximum power density of 488 mW cm -2, an open-circuit potential of 0.95 V, and a low electrode polarization resistance of 0.071 Ω cm2 were achieved at 700 °C. Preliminary results demonstrate that LPSF0.2-SDC composite is a promising cathode material for proton-conducting solid oxide fuel cells. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  4. Modeling of the filling and cooling processes of hot fuel mains in Liquid Fuel Rocket Power Plant (LFRPP)

    Science.gov (United States)

    Prisnyakov, V. F.; Pokrishkin, V. V.; Serebryansky, V. N.

    A mathematical model of heat and mass exchange processes during filling and cooling of hot fuel mains of the Liquid Fuel Rocket Power Plant (LFRPP), which allows to define a mass consumption and distribution of two-phase flow parameters by the length of pipeline. Results of calculations are compared with experimental data, taken during filling of the main with a supply of liquid oxygen from the tank into the combustion chamber. Also, the results of modeling of hydrogen main dynamic characteristics of LFRPP in the same conditions are given.

  5. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    Energy Technology Data Exchange (ETDEWEB)

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  6. SYSTEM AND PROCESS FOR PRODUCTION OF METHANOL FROM COMBINED WIND TURBINE AND FUEL CELL POWER

    Science.gov (United States)

    The paper examines an integrated use of ultra-clean wind turbines and high temperature fuel cells to produce methanol, especially for transportation purposes. The principal utility and application of the process is the production of transportation fuel from domestic resources to ...

  7. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    Science.gov (United States)

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2016-07-05

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  8. Literature on fabrication of tungsten for application in pyrochemical processing of spent nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom, C.M.; Phillips, A.G.; Johnson, L.D.; Corle, R.R.

    1980-10-11

    The pyrochemical processing of nuclear fuels requires crucibles, stirrers, and transfer tubing that will withstand the temperature and the chemical attack from molten salts and metals used in the process. This report summarizes the literature that pertains to fabrication (joining, chemical vapor deposition, plasma spraying, forming, and spinning) is the main theme. This report also summarizes a sampling of literature on molbdenum and the work previously performed at Argonne National Laboratory on other container materials used for pyrochemical processing of spent nuclear fuels.

  9. Parameterization for the Depth of the Entrainment Zone above the Convectively Mixed Layer

    Institute of Scientific and Technical Information of China (English)

    SUN Jianning; JIANG Weimei; CHEN Ziyun; YUAN Renmin

    2005-01-01

    It has been noted that when the convective Richardson number Ri* is used to characterize the depth of the entrainment zone, various parameterization schemes can be obtained. This situation is often attributed to the invalidity of parcel theory. However, evidence shows that the convective Richardson number Ri*might be an improper characteristic scaling parameter for the entrainment process. An attempt to use an innovative parameter to parameterize the entrainment-zone thickness has been made in this paper.Based on the examination of the data of water-tank experiments and atmospheric measurements, it is found that the total lapse rate of potential temperature across the entrainment zone is proportional to that of the capping inversion layer. Inserting this relationship into the so-called parcel theory, it thus gives a new parameterization scheme for the depth of the entrainment zone. This scheme includes the lapse rate of the capping inversion layer that plays an important role in the entrainment process. Its physical representation is reasonable. The new scheme gives a better ordering of the data measured in both watertank and atmosphere as compared with the traditional method using Ri*. These indicate that the parcel theory can describe the entrainment process suitably and that the new parameter is better than Ri*.

  10. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    Science.gov (United States)

    Collette, R.; King, J.; Buesch, C.; Keiser, D. D.; Williams, W.; Miller, B. D.; Schulthess, J.

    2016-07-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends when comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. The results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.

  11. Preparation and characterization of Ce0.8La0.2-xYxO1.9 as electrolyte for solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    田长安; 季必发; 谢劲松; 鲍巍涛; 刘可; 程继海; 尹奇异

    2014-01-01

    In this study, ultrafine Ce0.8La0.2–xYxO1.9 (for x=0, 0.05, 0.10, 0.15, 0.20) powders were successfully prepared by the sol-gel method. The samples were characterized by fourier transform infrared (FTIR), thermogravimetric and differential scanning calo-rimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), AC impedance and thermal expansion measure-ments. Experimental results indicated that highly phase-pure cubic fluorite electrolyte Ce0.8La0.2–xYxO1.9 powders were obtained after calcining at 600 °C. The as-synthesized powders exhibited high sintering activity, the Ce0.8La0.2–xYxO1.9 series electrolytes which have higher relative densities over 96%could be obtained after sintered at 1400 °C for 4 h. Ce0.8La0.15Y0.05O1.9 electrolyte sintered at 1400 °C for 4 h exhibited higher oxide ionic conductivity (σ800 ºC=0.057 S/cm), lower electrical activation energy (Ea=0.87 eV) and moder-ate thermal expansion coefficient (TEC=15.5×10−6 K−1, temperature range 25–800 °C).

  12. The performative pleasure of imprecision: a diachronic study of entrainment in music performance.

    Science.gov (United States)

    Geeves, Andrew; McIlwain, Doris J; Sutton, John

    2014-01-01

    This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Non-verbal communicative exchanges, via eye contact, gesture, and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance.

  13. The performative pleasure of imprecision: a diachronic study of entrainment in music performance

    Directory of Open Access Journals (Sweden)

    Andrew eGeeves

    2014-10-01

    Full Text Available This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Nonverbal communicative exchanges, via eye contact, gesture and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance.

  14. Investigating the Integration of a Solid Oxide Fuel Cell and a Gas Turbine System with Coal Gasification Technologies

    Science.gov (United States)

    2001-09-01

    conceptually integrate the hybrid power system with existing and imminent coal gasification technologies. The gasification technologies include the Kellogg...Brown Root (KBR) Transport Reactor and entrained coal gasification . Parametric studies will be performed wherein pertinent fuel cell stack process...dependent variables of interest. Coal gasification data and a proven SOFC model will be used to test the theoretical integration. Feasibility and

  15. Temperature compensation and entrainment in circadian rhythms

    Science.gov (United States)

    Bodenstein, C.; Heiland, I.; Schuster, S.

    2012-06-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles.

  16. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  17. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-11-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  18. Aqueous processing of U-10Mo scrap for high performance research reactor fuel

    Science.gov (United States)

    Youker, Amanda J.; Stepinski, Dominique C.; Maggos, Laura E.; Bakel, Allen J.; Vandegrift, George F.

    2012-08-01

    The Global Threat Reduction Initiative (GTRI) Conversion program, which is part of the US government's National Nuclear Security Administration (NNSA), supports the conversion of civilian use of highly enriched uranium (HEU) to low enriched uranium (LEU) for reactor fuel and targets. The reason for conversion is to eliminate the use of any material that may pose a threat to the United States or other foreign countries. High performance research reactors (HPRRs) cannot make the conversion to a standard LEU fuel because they require a more dense fuel to meet their performance requirements. As a result, a more dense fuel consisting of a monolithic uranium-molybdenum alloy containing 10% (w/w) Mo with Al cladding and a Zr bonding-layer is being considered. Significant losses are expected in the fabrication of this fuel, so a means to recycle the scrap pieces is needed. Argonne National Laboratory has developed an aqueous-processing flowsheet for scrap recovery in the fuel fabrication process for high-density LEU-monolithic fuel based on data found in the literature. Experiments have been performed to investigate dissolution conditions for solutions containing approximately 20 g-U/L and 50 g-U/L with and without Fe(NO3)3. HNO3 and HF concentrations have been optimized for timely dissolution of the fuel scrap and prevention of the formation of the U-Zr2 intermetallic, explosive complex, while meeting the requirements needed for further processing.

  19. Hydrogen production from methane steam reforming over Ni on high surface area CeO2 and CeO2-ZrO supports synthesized by surfactant-assisted method

    Directory of Open Access Journals (Sweden)

    Sumittra Charojrochkul

    2006-11-01

    Full Text Available Methane steam reforming performances of Ni on high surface area (HSA CeO2 and CeO2-ZrO2 supports have been studied under solid oxide fuel cell (SOFC operating conditions. Their performances were compared to general Ni/CeO2, Ni/CeO2-ZrO2, and Ni/Al2O3. It was firstly observed that Ni/CeO2-ZrO2 (HSA with the Ce/Zr ratio of 3/1 showed the best performance in terms of activity and stability toward the methane steam reforming among those with the Ce/Zr ratios of 1/1, 1/3, and 3/1. Both Ni/CeO2-ZrO2 (HSA and Ni/CeO2 (HSA presented better resistance toward carbon formation than the general Ni/CeO2, Ni/CeO2- ZrO2, and Ni/Al2O3 at the same operating conditions. These benefits are related to the high oxygen storage capacity (OSC of CeO2-ZrO2. During the steam reforming process, in addition to the reactions on Ni surface (*, the redox reactions between the gaseous components presented in the system and the lattice oxygen (Ox on CeO2-ZrO2 surface also take place. Among these reactions, the redox reactions between the high carbon formation potential compounds (CH4, CHx-*n and CO and the lattice oxygen (Ox can prevent the formation of carbon species from the methane decomposition and Boudard reactions at the inlet H2O/CH4 ratio of 3.0/1.0.

  20. The conceptual analysis of MBA and KMP for advanced spent fuel management process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Yoon; Ko, Won Il; Ha, Jang Ho; Kim, Ho Dong; Koo, Dae Seo [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    This report describes the concept of dry reprocessing of molten salt which is proposed as nuclear fuel cycle with nuclear proliferation resistance. These basic researches in Japan, U. S., Russia are in progress, and Republic of Korea is performing basic research of metallic conversion fabrication of molten salt of uranium dioxide fuels through nuclear research project. In this report, we have performed conceptual analysis and establishment of MBA and KMP for nuclear material safeguards in order to accomplish metallic conversion research of molten salt of uranium dioxide fuels. This report will contribute to the implementation of nuclear material safeguards of advanced spent fuel management process, and also the usage of basic data of nuclear material safeguards for spent fuel recycling process of native country. 11 refs., 17 figs., 8 tabs. (Author)

  1. Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system

    Science.gov (United States)

    Thaut, Michael H.; McIntosh, Gerald C.; Hoemberg, Volker

    2015-01-01

    Entrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy. PMID:25774137

  2. Neurobiological Foundations of Neurologic Music Therapy: Rhythmic Entrainment and the Motor System

    Directory of Open Access Journals (Sweden)

    Michael eThaut

    2015-02-01

    Full Text Available AbstractEntrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks and biological systems (e.g. fire flies. However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al, 1999. Physiological, kinematic and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of Neurologic Music Therapy.

  3. Numerical Studies on Controlling Gaseous Fuel Combustion by Managing the Combustion Process of Diesel Pilot Dose in a Dual-Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2015-06-01

    Full Text Available Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.

  4. An Update on NiCE Support for BISON

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deyton, Jordan H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wojtowicz, Anna [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  5. Economical process for growing seaweed as biomass fuel source

    Energy Technology Data Exchange (ETDEWEB)

    Lagovskiy, V.

    1985-10-10

    Calculations made by researchers of Moscow State University have shown that the Aral Sea is capable of providing energy for almost the entire country. An experimental unit called Biosolar, for growing such energy already exists. Up to 40 liters of fuel gas a day can be gathered from a single square meter of plant beds. Seaweed yields biomass, which is placed in special vats. There it is eaten by bacteria, which release methane.

  6. Optimization of fuel supply map during starting process of electronic controlled diesel engine

    Institute of Scientific and Technical Information of China (English)

    Jinguang LIANG; Xiumin YU; Yue GAO; Yunkai WANG; Hongyang YU; Baoli GONG

    2008-01-01

    Tests were conducted to study influence of fuel supply map during the starting process of an electronic con-trolled diesel engine using an electronic controlled diesel engine which was made up of a CA498Z diesel engine, a VP37 elec-tronic controlled distributor injection pump management system and a VS100 calibration system. The calibration pro-cess of starting fuel supply map was educed under the principle of low HC emission and rapid starting velocity. The cal-ibration methods of starting fuel supply map were obtained.

  7. A model study of mixing and entrainment in the horizontally evolving atmospheric convective boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Fedorovich, E.; Kaiser, R. [Univ. Karlsruhe, Inst. fuer Hydrologie und Wasserwirtschaft (Germany)

    1997-10-01

    We present results from a parallel wind-tunnel/large-eddy simulation (LES) model study of mixing and entrainment in the atmospheric convective boundary layer (CBL) longitudinally developing over a heated surface. The advection-type entrainment of warmer air from upper turbulence-free layers into the growing CBL has been investigated. Most of numerical and laboratory model studies of the CBL carried out so far dealt with another type of entrainment, namely the non-steady one, regarding the CBL growth as a non-stationary process. In the atmosphere, both types of the CBL development can take place, often being superimposed. (au)

  8. Composite Fe - BaCe0.2Zr0.6Y0.2O2.9 Anodes for Proton Conductor Fuel Cells

    DEFF Research Database (Denmark)

    Lapina, Alberto; Chatzichristodoulou, Christodoulos; Holtappels, Peter;

    2014-01-01

    Symmetrical cells with Fe - BaCe0.2Zr0.6Y0.2O2.9 composite electrodes are produced by screen printing and infiltration, using BaCe0.2Zr0.6Y0.2O2.9 as electrolyte. The electrochemical performance of the composite electrode is studied by impedance spectroscopy at 250–500◦C in dry and wet hydrogen....../nitrogen mixtures. The polarization resistance is 1.6 _ cm2 at 500◦C in wet H2 (pH2O = 0.01 atm), and has an activation energy of 0.72 eV. The cells degrade upon exposure to temperatures up to 500◦C, likely due to coarsening of the iron nanoparticles and loss of electronic percolation in the composite anode. Iron...

  9. Development and control of the process for the manufacture of zircaloy-4 tubing for LWBR fuel rods

    Energy Technology Data Exchange (ETDEWEB)

    Eyler, J.H.

    1981-01-01

    The technical requirements for the Light Water Breeder Reactor (LWBR) fuel elements (fuel rods) imposed certain unique requirements for the low hafnium Zircaloy-4 tubing used as fuel rod cladding. This report describes, in detail, the tube manufacturing process, the product and process controls used, the inspections and tests performed, and the efforts involved in refining a commercial tube reducing process to produce tubes that would satisfy the requirements for LWBR fuel rod cladding.

  10. Flow Dynamics and Sediment Entrainment in Natural Turbidity Currents Inferred from Numerical Modeling

    Science.gov (United States)

    Traer, M. M.; Hilley, G. E.; Fildani, A.

    2009-12-01

    Submarine turbidity currents derive their momentum from gravity acting upon the density contrast between sediment-laden and clear water, and so unlike fluvial systems, the dynamics of such flows are inextricably linked to the rates at which they deposit and entrain sediment. We have analyzed the sensitivity of the growth and maintenance of turbidity currents to sediment entrainment and deposition using the layer-averaged equations of conservation of fluid and sediment mass, and conservation of momentum and turbulent kinetic energy. Our model results show that the dynamics of turbidity currents are extremely sensitive to the functional form and empirical constants of the relationship between sediment entrainment and friction velocity. Data on the relationship between sediment entrainment and friction velocity for submarine density flows are few and as a result, entrainment formulations are populated with data from sub-aerial flows not driven by the density contrast between clear and turbid water. If we entertain the possibility that sediment entrainment in sub-aerial rivers is different than in dense underflows, flow parameters such as velocity, height, and concentration were found nearly impossible to predict beyond a few hundred meters based on the limited laboratory data available that constrain the sediment entrainment process in turbidity currents. The sensitivity of flow dynamics to the functional relationship between friction velocity and sediment entrainment indicates that independent calibration of a sediment entrainment law in the submarine environment is necessary to realistically predict the dynamics of these flows and the resulting patterns of erosion and deposition. To calibrate such a relationship, we have developed an inverse methodology that utilizes existing submarine channel morphology as a means of constraining the sediment entrainment function parameters. We use a Bayesian Metropolis-Hastings sampler to determine the sediment entrainment

  11. TRISO-Coated Fuel Processing to Support High Temperature Gas-Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Del Cul, G.D.

    2002-10-01

    The initial objective of the work described herein was to identify potential methods and technologies needed to disassemble and dissolve graphite-encapsulated, ceramic-coated gas-cooled-reactor spent fuels so that the oxide fuel components can be separated by means of chemical processing. The purpose of this processing is to recover (1) unburned fuel for recycle, (2) long-lived actinides and fission products for transmutation, and (3) other fission products for disposal in acceptable waste forms. Follow-on objectives were to identify and select the most promising candidate flow sheets for experimental evaluation and demonstration and to address the needs to reduce technical risks of the selected technologies. High-temperature gas-cooled reactors (HTGRs) may be deployed in the next -20 years to (1) enable the use of highly efficient gas turbines for producing electricity and (2) provide high-temperature process heat for use in chemical processes, such as the production of hydrogen for use as clean-burning transportation fuel. Also, HTGR fuels are capable of significantly higher burn-up than light-water-reactor (LWR) fuels or fast-reactor (FR) fuels; thus, the HTGR fuels can be used efficiently for transmutation of fissile materials and long-lived actinides and fission products, thereby reducing the inventory of such hazardous and proliferation-prone materials. The ''deep-burn'' concept, described in this report, is an example of this capability. Processing of spent graphite-encapsulated, ceramic-coated fuels presents challenges different from those of processing spent LWR fuels. LWR fuels are processed commercially in Europe and Japan; however, similar infrastructure is not available for processing of the HTGR fuels. Laboratory studies on the processing of HTGR fuels were performed in the United States in the 1960s and 1970s, but no engineering-scale processes were demonstrated. Currently, new regulations concerning emissions will impact the

  12. Advanced diagnostics in oxy-fuel combustion processes

    Energy Technology Data Exchange (ETDEWEB)

    Brix, J.; Clausen, Soennik; Degn Jensen, A. (Technical Univ. of Denmark. CHEC Research Centre, Kgs. Lyngby (Denmark)); Boeg Toftegaard, M. (DONG Energy Power, Hvidovre (Denmark))

    2012-07-01

    This report sums up the findings in PSO-project 010069, ''Advanced Diagnostics in Oxy-Fuel Combustion Processes''. Three areas of optic diagnostics are covered in this work: - FTIR measurements in a 30 kW swirl burner. - IR measurements in a 30 kW swirl burner. - IR measurements in a laboratory scale fixed bed reactor. The results obtained in the swirl burner have proved the FTIR method as a valuable technique for gas phase temperature measurements. When its efficacy is evaluated against traditional thermocouple measurements, two cases, with and without probe beam stop, must however be treated separately. When the FTIR probe is operated with the purpose of gas phase concentration measurements the probe needs to operate with a beam stop mounted in front of it. With this beam stop in place it was shown that the measured gas phase temperature was affected by cooling, induced by the cooled beam stop. Hence, for a more accurate determination of gas phase temperatures the probe needed to operate without the beam stop. When this was the case, the FTIR probe showed superior to traditional temperature measurements using a thermocouple as it could measure the fast temperature fluctuations. With the beam stop in place the efficacy of the FTIR probe for gas temperature determination was comparable to the use of a traditional thermocouple. The evaluation of the FTIR technique regarding estimation of gas phase concentrations of H{sub 2}O, CO{sub 2} and CO showed that the method is reliable though it cannot be stated as particularly accurate. The accuracy of the method is dependent on the similarity of the reference emission spectra of the gases with those obtained in the experiments, as the transmittance intensity is not a linear function of concentration. The length of the optical path also affects the steadiness of the measurements. The length of the optical path is difficult to adjust on the small scales that are the focus of this work. However

  13. Observations and modelling of snow avalanche entrainment

    Directory of Open Access Journals (Sweden)

    B. Sovilla

    2002-01-01

    Full Text Available In this paper full scale avalanche dynamics measurements from the Italian Pizzac and Swiss Vallée de la Sionne test sites are used to develop a snowcover entrainment model. A detailed analysis of three avalanche events shows that snowcover entrainment at the avalanche front appears to dominate over bed erosion at the basal sliding surface. Furthermore, the distribution of mass within the avalanche body is primarily a function of basal friction. We show that the mass distribution in the avalanche changes the flow dynamics significantly. Two different dynamical models, the Swiss Voellmy-fluid model and the Norwegian NIS model, are used to back calculate the events. Various entrainment methods are investigated and compared to measurements. We demon-strate that the Norwegian NIS model is clearly better able to simulate the events once snow entrainment has been included in the simulations.

  14. Hydrogen purification for fuel cell using CuO/CeO{sub 2}-Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Cristhiane Guimaraes; Assaf, Jose Mansur [Universidade Federal de Sao Carlos, Departamento de Engenharia Quimica, Via Washington Luiz, Km 235, CEP: 13565-905, Sao Carlos, SP (Brazil); Profeti, Luciene Paula Roberto; Assaf, Elisabete Moreira [Universidade de Sao Paulo, Departamento de Fisico-Quimica, Avenida Trabalhador Sao Carlense 400, CEP: 13560-970, Sao Carlos, SP (Brazil)

    2011-01-15

    CuO/CeO{sub 2}, CuO/Al{sub 2}O{sub 3} and CuO/CeO{sub 2}-Al{sub 2}O{sub 3} catalysts, with CuO loading varying from 1 to 5 wt.%, were prepared by the citrate method and applied to the preferential oxidation of carbon monoxide in a reaction medium containing large amounts of hydrogen (PROX-CO). The compounds were characterized ex situ by X-ray diffraction, specific surface area measurements, temperature-programmed reduction and temperature-programmed reduction of oxidized surfaces; XANES-PROX in situ experiments were also carried out to study the copper oxidation state under PROX-CO conditions. These analyses showed that in the reaction medium the Cu{sup 0} is present as dispersed particles. On the ceria, these metallic particles are smaller and more finely dispersed, resulting in a stronger metal-support interaction than in CuO/Al{sub 2}O{sub 3} or CuO/CeO{sub 2}-Al{sub 2}O{sub 3} catalysts, providing higher PROX-CO activity and better selectivity in the conversion of CO to CO{sub 2} despite the greater BET area presented by samples supported on alumina. It is also shown that the lower CuO content, the higher metal dispersion and consequently the catalytic activity. The redox properties of the ceria support also contributed to catalytic performance. (author)

  15. Review of the literature for dry reprocessing oxide, metal, and carbide fuel: The AIROX, RAHYD, and CARBOX pyrochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, R.C.; Rhee, B.W. [Rockwell International Corp., Canoga Park, CA (United States). Energy Systems Group

    1979-09-30

    The state of the art of dry processing oxide, carbide, and metal fuel has been determined through an extensive literature review. Dry processing in one of the most proliferation resistant fuel reprocessing technologies available to date, and is one of the few which can be exported to other countries. Feasibility has been established for oxide, carbide, and metal fuel on a laboratory scale, and large-scale experiments on oxide and carbide fuel have shown viability of the dry processing concept. A complete dry processing cycle has been demonstrated by multicycle processing-refabrication-reirradiation experiments on oxide fuel. Additional experimental work is necessary to: (1) demonstrate the complete fuel cycle for carbide and metal fuel, (2) optimize dry processing conditions, and (3) establish fission product behavior. Dry process waste management is easier than for an aqueous processing facility since wastes are primarily solids and gases. Waste treatment can be accomplished by techniques which have been, or are being, developed for aqueous plants.

  16. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    Energy Technology Data Exchange (ETDEWEB)

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  17. Washing of the AN-107 entrained solids

    Energy Technology Data Exchange (ETDEWEB)

    GJ Lumetta; FV Hoopes

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing on the composition of the entrained solids in the diluted AN-107 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AN-107 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching.

  18. Observations and modelling of snow avalanche entrainment

    OpenAIRE

    2002-01-01

    In this paper full scale avalanche dynamics measurements from the Italian Pizzac and Swiss Vallée de la Sionne test sites are used to develop a snowcover entrainment model. A detailed analysis of three avalanche events shows that snowcover entrainment at the avalanche front appears to dominate over bed erosion at the basal sliding surface. Furthermore, the distribution of mass within the avalanche body is primarily a function of basal fric...

  19. Controllability of plutonium concentration for FBR fuel at a solvent extraction process in the PUREX process

    Energy Technology Data Exchange (ETDEWEB)

    Enokida, Youichi; Kitano, Motoki; Sawada, Kayo [Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya-shi, Aichi-ken, 4630052 (Japan)

    2013-07-01

    Typical Purex solvent extraction systems for the reprocessing of spent nuclear fuel have a feed material containing dilute, 1% in weight, plutonium, along with uranium and fission products. Current reprocessing proposals call for no separation of the pure plutonium. The work described in this paper studied, by computer simulation, the fundamental feasibility of preparing a 20% concentrated plutonium product solution from the 1% feed by adjusting only the feed rates and acid concentrations of the incoming streams and without the addition of redox reagents for the plutonium. A set of process design flowsheets has been developed to realize a concentrated plutonium solution of a 20% stream from the dilute plutonium feed without using redox reagents. (authors)

  20. Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

    Energy Technology Data Exchange (ETDEWEB)

    SEXTON, R.A.

    2000-03-13

    The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation.

  1. Modeling of Diffusive Convective and Electromechanical Processes in PEM fuel cells

    DEFF Research Database (Denmark)

    Bang, Mads

    of their impact on the operational performance of the fuel cell. In the modelling work presented, the commercial CFD package CFX4.4 is used as the foundation to generate a model of a PEM fuel cell. The CFX4.4 platform provides the framework of solving the three-dimensional transport equations for mass, momentum...... of the gaseous phase in the fuel cell and allows prediction of the concentration of the species present. A special feature of the approach developed is a method that allows detailed modelling and prediction of electrode kinetics. The transport of electrons in the gas diffusion layer and catalyst layer, as well......In the report, the transport phenomena in a proton exchange membrane fuel cell fueled by hydrogen and air, is analyzed, and a comprehensive three dimensional computerized model of the cell is presented. The model accounts for most of the major transport processes and allow the prediction...

  2. High liquid fuel yielding biofuel processes and a roadmap for the future transportation

    Science.gov (United States)

    Singh, Navneet R.

    In a fossil-fuel deprived world when crude oil will be scarce and transportation need cannot be met with electricity and transportation liquid fuel must be produced, biomass derived liquid fuels can be a natural replacement. However, the carbon efficiency of the currently known biomass to liquid fuel conversion processes ranges from 35-40%, yielding 90 ethanol gallon equivalents (ege) per ton of biomass. This coupled with the fact that the efficiency at which solar energy is captured by biomass (syngas derived from coal gasification (H2Bioil-C) or a natural gas reformer (H 2Bioil-NG) is used to supply the hydrogen and process heat for the biomass fast-hydropyrolysis/hydrodeoxygenation. Another off-shoot of the H2Bioil process is the H2Bioil-B process, where hydrogen required for the hydropyrolysis is obtained from gasification of a fraction of the biomass. H2Bioil-B achieves the highest liquid fuel yield (126-146 ege/ton of biomass) reported in the literature for any self-contained conversion of biomass to biofuel. Finally, an integration of the H2Bioil process with the H2CAR process is suggested which can achieve 100% carbon efficiency (330 ege/ton of biomass) at the expense of 0.24 kg hydrogen/liter of oil. A sun-to-fuel efficiency analysis shows that extracting CO2 from air and converting it to liquid fuel is at least two times more efficient than growing dedicated fuel crops and converting them to liquid fuel even for the highest biomass growth rates feasible by algae. This implies that liquid fuel should preferably be produced from sustainably available waste (SAW) biomass first and if the SAW biomass is unable to meet the demand for liquid fuel, then, CO2 should be extracted from air and converted to liquid fuel, rather than growing biomass. Furthermore, based on the Sun-to-Wheels recovery for different transportation pathways, synergistic and complementary use of electricity, hydrogen and biomass, all derived from solar energy, is presented in an energy

  3. Scrap tire process turns waste into fuel. [USA - New York

    Energy Technology Data Exchange (ETDEWEB)

    Tesla, M.R. (New York State Electric and Gas Corporation, Binghamton, NY (United States). Alternate Fuels Development)

    1994-05-01

    New York State Electric Gas Corp. (NYSEG) has in the last three years burned more than 1.3 million tyres to generate power, saving more than 16,000 tons of coal. The article describes how at the 73 MW Jennison power station scrap tires are chopped into 2x2 in. chips prior to mixing with coal near the coal pile (in a 20.80 tire chip to coal ratio) and combustion in stoker boilers with travelling chain grates. NYSEG has also test burned other alternative fuels such as creosote-treated wood and coal tar soils. 6 photos.

  4. Stratocumulus Precipitation and Entrainment Experiment (SPEE) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Bruce [Univ. of Miami, Miami, FL (United States); Ghate, Virendra [Argonne National Lab. (ANL), Argonne, IL (United States); CADeddu, Maria [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-06-01

    The scientific focus of this project was to examine precipitation and entrainment processes in marine stratocumulus clouds. The entrainment studies focused on characterizing cloud turbulence at cloud top using Doppler cloud radar observations. The precipitation studies focused on characterizing the precipitation and the macroscopic properties (cloud thickness, and liquid water path) of the clouds. This project will contribute to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s overall objective of providing the remote-sensing observations needed to improve the representation of key cloud processes in climate models. It will be of direct relevance to the components of ARM dealing with entrainment and precipitation processes in stratiform clouds. Further, the radar observing techniques that will be used in this study were developed using ARM Southern Great Plains (SGP) facility observations under Atmospheric System Research (ASR) support. The observing systems operating automatously from a site located just north of the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) aircraft hangar in Marina, California during the period of 1 May to 4 November 2015 included: 1. Microwave radiometer: ARM Microwave Radiometer, 3-Channel (MWR3C) with channels centered at 23.834, 30, and 89 GHz; supported by Dr. Maria Cadeddu. 2. Cloud Radar: CIRPAS 95 GHz Frequency Modulated Continuous Wave (FMCW) Cloud Radar (Centroid Frequency Chirp Rate [CFCR]); operations overseen by Drs. Ghate and Albrecht. 3. Ceilometer: Vaisala CK-14; operations overseen by Drs. Ghate and Albrecht.

  5. Music and emotions: from enchantment to entrainment.

    Science.gov (United States)

    Vuilleumier, Patrik; Trost, Wiebke

    2015-03-01

    Producing and perceiving music engage a wide range of sensorimotor, cognitive, and emotional processes. Emotions are a central feature of the enjoyment of music, with a large variety of affective states consistently reported by people while listening to music. However, besides joy or sadness, music often elicits feelings of wonder, nostalgia, or tenderness, which do not correspond to emotion categories typically studied in neuroscience and whose neural substrates remain largely unknown. Here we review the similarities and differences in the neural substrates underlying these "complex" music-evoked emotions relative to other more "basic" emotional experiences. We suggest that these emotions emerge through a combination of activation in emotional and motivational brain systems (e.g., including reward pathways) that confer its valence to music, with activation in several other areas outside emotional systems, including motor, attention, or memory-related regions. We then discuss the neural substrates underlying the entrainment of cognitive and motor processes by music and their relation to affective experience. These effects have important implications for the potential therapeutic use of music in neurological or psychiatric diseases, particularly those associated with motor, attention, or affective disturbances.

  6. Material control in nuclear fuel fabrication facilities. Part I. Fuel descriptions and fabrication processes, P. O. 1236909 Final report

    Energy Technology Data Exchange (ETDEWEB)

    Borgonovi, G.M.; McCartin, T.J.; Miller, C.L.

    1978-12-01

    The report presents information on foreign nuclear fuel fabrication facilities. Fuel descriptions and fuel fabrication information for three basic reactor types are presented: The information presented for LWRs assumes that Pu--U Mixed Oxide Fuel (MOX) will be used as fuel.

  7. An integrated MEMS infrastructure for fuel processing: hydrogen generation and separation for portable power generation

    Science.gov (United States)

    Varady, M. J.; McLeod, L.; Meacham, J. M.; Degertekin, F. L.; Fedorov, A. G.

    2007-09-01

    Portable fuel cells are an enabling technology for high efficiency and ultra-high density distributed power generation, which is essential for many terrestrial and aerospace applications. A key element of fuel cell power sources is the fuel processor, which should have the capability to efficiently reform liquid fuels and produce high purity hydrogen that is consumed by the fuel cells. To this end, we are reporting on the development of two novel MEMS hydrogen generators with improved functionality achieved through an innovative process organization and system integration approach that exploits the advantages of transport and catalysis on the micro/nano scale. One fuel processor design utilizes transient, reverse-flow operation of an autothermal MEMS microreactor with an intimately integrated, micromachined ultrasonic fuel atomizer and a Pd/Ag membrane for in situ hydrogen separation from the product stream. The other design features a simpler, more compact planar structure with the atomized fuel ejected directly onto the catalyst layer, which is coupled to an integrated hydrogen selective membrane.

  8. Managing probe applications effectively? The process of pre-commercial fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, H.L. [Delft Univ. of Technology, Delft (Netherlands)

    2007-07-01

    There has been a high degree of uncertainty regarding market adoption of proton exchange membrane (PEM) fuel cell technologies, making it challenging for fuel cell firms to determine which markets to pursue at which point in time. Probes, such as prototypes, demonstrations and field trials, are market experiments conducted by fuel cell firms and industry that are central to the commercialization of fuel cell technology. However, demonstration projects are extremely resource and time intensive, and outcomes are uncertain. This paper reviewed innovation management literature on the characteristics of the technology application process. Case study research of four fuel cell firms were discussed in terms of probe objectives and outcomes. An analysis of probe application patterns over time was also presented. Several fuel cell projects were also analyzed in terms of motivations and lessons learned. The paper focused on young independent fuel cell developers that had limited resources to allocate and waste resources on ineffective probe applications. The findings complement prior research that have found probe applications a valuable tool for learning, stimulating market demand and network formation. The paper made several recommendations regarding the main objectives of the fuel cell project, to set realistic goals and align expectations between consortia members. In addition, it was found that a short term demonstration project may appear to be an attractive application, but a project with a longer term vision and a commercial value proposition was more likely to attract stakeholders. 16 refs., 3 figs.

  9. Gasification process of refuse derived fuel in circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, S.; Kinoshita, Y.; Lee, C.W.; Itaya, Y.; Mori, S. [Nagoya Univ., Nagoya (Japan). Dept. of Chemical Engineering

    2002-07-01

    This paper presents a fuel gas production system involving gasification of refuse-derived fuel (RDF) in a circulating fluidized bed (CFB). Although RDF is considered to be a viable source of energy, combustion of RDF has not spread widely because of a lack of conventional incinerators, erosion due to hydrogen chloride, and emissions of dioxin. This paper presents the results of an experimental study of the pyrolysis behaviour of 3 kinds of RDF and the particle motion in a cold model CFB. The objective was to clarify operating parameters for optimum control. It was shown that an increase in combustion temperature improves the yield of the combustible gas components and the energy recycling efficiency from the RDF. The highest heating value of pyrolysis gas was obtained at 873 to 973 degrees K. The gas flow rate in the pneumatic valve of the CFB was an important control factor for the circulation flux and solids holdup in the riser. High holdups were observed when minute silica sand particles were used in the CFB. 15 refs., 1 tab., 8 figs.

  10. Synthesis, characterization and mechanical properties of NiO - GDC20 (Ce0.8Gd0.2O1.9) nano composite anode for solid oxide fuel cells

    Science.gov (United States)

    Reddy, M. Narsimha; Rao, P. Vijaya Bhaskar; Sharma, R. K.

    2016-05-01

    In the present research work, X (NiO) +1-X(Ce0.8Gd0.2O1.9) where X = 30,40 and 45 wt% Nano Composite Anodes are synthesized for low temperature operating solid oxide fuel cells (SOFC). NiO and Ce0.8Gd0.2O1.9 (GDC20) are synthesized by sol-gel citrate method and the nanopowders of NiO, GDC20 were calcined from 650 °c to 750 °c. For anode materials, pelletized the nanocomposites of X(NiO)+ (1-X) GDC20 (X = 30,40,45 wt.%) and sintered at 1200 °c. systematic study of atomic structure, purity, phase and structural parameters such as Lattice parameters, crystallite size of as-synthesized nanopowders and anode materials were carried out by XRD and SEM. For mechanical strength, Vickers micro-hardness of anode composites were estimated and observed that micro-hardness of composites were increasing with NiO wt.% and the density of sintered samples, which is varying from 4.35 to 5.54 Gpa at 500g load.

  11. Fuel and canister process report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Werme, Lars (ed.)

    2006-10-15

    This report documents fuel and canister processes identified as relevant to the long-term safety of a KBS-3 repository. It forms an important part of the reporting of the safety assessment SR-Can. The detailed assessment methodology, including the role of the process report in the assessment, is described in the SR-Can Main report. The report is written by, and for, experts in the relevant scientific fields. It should though be possible for a generalist in the area of long-term safety assessments of geologic nuclear waste repositories to comprehend the contents of the report. The report is an important part of the documentation of the SR-Can project and an essential reference within the project, providing a scientifically motivated plan for the handling of geosphere processes. It is, furthermore, foreseen that the report will be essential for reviewers scrutinising the handling of geosphere issues in the SR-Can assessment. Several types of fuel will be emplaced in the repository. For the reference case with 40 years of reactor operation, the fuel quantity from boiling water reactors, BWR fuel, is estimated at 7,000 tonnes, while the quantity from pressurized water reactors, PWR fuel, is estimated at about 2,300 tonnes. In addition, 23 tonnes of mixed-oxide fuel (MOX) fuel of German origin from BWR and PWR reactors and 20 tonnes of fuel from the decommissioned heavy water reactor in Aagesta will be disposed of. To allow for future changes in the Swedish nuclear programme, the safety assessment assumes a total of 6,000 canister corresponding to 12,000 tonnes of fuel.

  12. Additive effect of Ce, Mo and K to nickel-cobalt aluminate supported solid oxide fuel cell for direct internal reforming of methane

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Bu Ho; Park, Jungdeok; Yoon, Heechul; Kim, Hyeon Hui; Kim, Lim; Chung, Jong Shik [POSTECH, Pohang (Korea, Republic of)

    2014-01-15

    Direct internal reforming of methane (steam/carbon=0.031, 850 .deg. C) is tested using button cells of Ni-YSZ/YSZ/LSM in which the anode layer is supported either on Ni-YSZ or on Ni-CoAl{sub 2}O{sub 4}. The Ni-CoAl{sub 2}O{sub 4} supported cell shows little degradation with operating time, as a result of higher resistance against carbon deposition, whereas the Ni-YSZ supported cell deactivates quickly and suffers fracture in 50 h. Upon incorporation of additives such as K, Ce, or Mo into the Ni-CoAl{sub 2}O{sub 4} support, cells with 0.5 wt% CeO{sub 2} exhibit the best stable performance as a result of reduced coke formation. Cells with 0.5 wt% Mo exhibit the lowest performance. Although no carbon deposit is detected in the cells with K{sub 2}CO{sub 3} additives, their performance is worse than that in the CeO{sub 2} case, and, in constant-current mode, there is a sudden voltage drop to zero after a certain period of time; this time becomes shorter with increasing K content. The injection of potassium into the anode side facilitates the generation of OH{sup -} and CO{sub 3}{sup 2-} in the anode and promotes the diffusion of these ions to the cathode. Increased polarization resistance at the cathode and increased electrolyte resistance result in such a sudden failure.

  13. Fluid dynamics simulations of a fuel processing system; Stroemungsmechanische Modellierung eines Brenngaserzeugungssystems

    Energy Technology Data Exchange (ETDEWEB)

    Scharf, Florian

    2012-07-01

    The present thesis deals with the topic of the complete fluid dynamic modelling of the key components of a fuel processing system and based on it the development of the next generation reactors. Fuel cell auxilliary power units enable an energy efficient power generation for mobile applications with higher on-board power consumption. Enabling the operation of the fuel cell with the available middle-destillate on-board, the fuel is transformed to an hydrogen-rich gas in a fuel processing system consisting of the key components autothermal reformer, water-shift reactor and catalytic burner. The modules of the fuel processing system are thereby integrated within the reactors to obtain a lightweighted and compact overall system. The complete numerical description of theses systems are based on chemical-reaction models, vaporization models of fuel and water in the integrated reactant treatment and as well on models for the integrated heat-exchanger. The strong interaction between the single reactor zones require therefore modelling of the key components as an overall reactor system. The methodology of the present thesis is based on a tight integration of CFD simulations with experimental analysis and the construction of the reactors. The results of carried out prototype testings, post-mortem-analysis and laboratory experiments are taken as basis for the CFD modelling and the reactor construction. As numerical tool for fluid dynamic modelling the CFD software FLUENT was used. In the context of this thesis the CFD modelling library was extended with the purpose of the complete description of key components in the CFD overall model. In these CFD overall models the thermal interactions between the reactor zones as well as the influence of the pulsating fuel injection and the chemical reactions are taken into account. For this purpose a similarity theoretical CFD modell of the pulsating fuel injection was generated based on results from prototype testings and high

  14. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    Science.gov (United States)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E.; Bridges, Andrea N. A.; Rudisill, Tracy S.; Hobbs, David T.; Phillip, William A.; Burns, Peter C.

    2016-05-01

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid-liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing.

  15. Influence of high injection pressure on fuel injection perfomances and diesel engine worcking process

    Directory of Open Access Journals (Sweden)

    Shatrov Mikhail G.

    2015-01-01

    Full Text Available In MADI, investigations are carried out in the field of diesel engine working process perfection for complying with prospective ecological standards such as Euro-6 and Tier-4. The article describes the results of the first stage of experimental research of the influence of injection pressure up to 3000 bar on working processes of diesel engine and its fuel system. Justification of the design of a Common Rail injector for fuel injection under 3000 bar pressure is presented. The influence of raising injection pressure (up to 3000 bar on the fuel spray propagation dynamics is demonstrated. The combined influence of injection pressure (up to 3000 bar and air boost pressure on fuel spray propagation dynamics is shown, including on engine emission and noise.

  16. Synthesis and characterization of Ce_(0.8)Sm_(0.2)O_(1.9) nanopowders using an acrylamide polymerization process

    Institute of Scientific and Technical Information of China (English)

    郑颖平; 王绍荣; 王振荣; 邬理伟; 孙岳明

    2010-01-01

    Ce0.8Sm0.2O1.9(SDC) nanopowders were synthesized by an acrylamide polymerization process.The XRD results showed that SDC powders prepared at 700 °C possessed a cubic fluorite structure.Transmission electron microscopy(TEM) indicated that the particle sizes of powders were in the range of 10-15 nm.A 98.3% of theoretical density was obtained when the SDC pellets were sintered at 1350 °C for 5 h,indicating that the powders had good sinterability.The conductivity of the sintered SDC ceramics was 0.019 S/cm at 6...

  17. Factors controlling the microstructure of Ce0.9Gd0.1O2-δ films in pulsed laser deposition process

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, S.; Döbeli, M.;

    2010-01-01

    Films of Ce0.9Gd0.1O2-delta (CGO10) are prepared at a range of conditions by pulsed laser deposition (PLD) on a single crystal Si (100) and MgO (100), and on a polycrystalline Pt/MgO (100) substrate. The relationship between the film microstructure, crystallography, chemical composition and PLD...... processing parameters is studied. It is found that the laser fluence has no significant impact on the film density, whereas the substrate temperature and the oxygen pressure are of essential importance for the film microstructure development. The reduction of deposition temperature, down to 250 oC, together...

  18. Bubble entrainment, spray and splashing at hydraulic jumps

    Institute of Scientific and Technical Information of China (English)

    CHANSON Hubert

    2006-01-01

    The sudden transition from a high-velocity, supercritical open channel flow into a slow-moving sub-critical flow is a hydraulic jump. Such a flow is characterised by a sudden rise of the free-surface, with some strong energy dissipation and air entrainment, waves and spray. New two-phase flow measurements were performed in the developing flow region using a large-size facility operating at large Reynolds numbers. The experimental results demonstrated the complexity of the flow with a developing mixing layer in which entrained bubbles are advected in a high shear stress flow. The relationship between bubble count rates and void fractions was non-unique in the shear zone, supporting earlier observations of some form of double diffusion process between momentum and air bubbles. In the upper region, the flow consisted primarily of water drops and packets surrounded by air. Visually significant pray and splashing were significant above the jump roller. The present study is the first comprehensive study detailing the two-phase flow properties of both the bubbly and spray regions of hydraulic jumps, a first step towards understanding the interactions between bubble entrainment and droplet ejection processes.

  19. Simulation of primary fuel atomization processes at subcritical pressures.

    Energy Technology Data Exchange (ETDEWEB)

    Arienti, Marco

    2013-06-01

    This report documents results from an LDRD project for the first-principles simulation of the early stages of spray formation (primary atomization). The first part describes a Cartesian embedded-wall method for the calculation of flow internal to a real injector in a fully coupled primary calculation. The second part describes the extension to an all-velocity formulation by introducing a momentum-conservative semi-Lagrangian advection and by adding a compressible term in the Poissons equation. Accompanying the description of the new algorithms are verification tests for simple two-phase problems in the presence of a solid interface; a validation study for a scaled-up multi-hole Diesel injector; and demonstration calculations for the closing and opening transients of a single-hole injector and for the high-pressure injection of liquid fuel at supersonic velocity.

  20. Granular motions near the threshold of entrainment

    Science.gov (United States)

    Valyrakis, Manousos; Alexakis, athanasios-Theodosios

    2016-04-01

    Our society is continuously impacted by significant weather events many times resulting in catastrophes that interrupt our normal way of life. In the context of climate change and increasing urbanisation these "extreme" hydrologic events are intensified both in magnitude and frequency, inducing costs of the order of billions of pounds. The vast majority of such costs and impacts (even more to developed societies) are due to water related catastrophes such as the geomorphic action of flowing water (including scouring of critical infrastructure, bed and bank destabilisation) and flooding. New tools and radically novel concepts are in need, to enable our society becoming more resilient. This presentation, emphasises the utility of inertial sensors in gaining new insights on the interaction of flow hydrodynamics with the granular surface at the particle scale and for near threshold flow conditions. In particular, new designs of the "smart-sphere" device are discussed with focus on the purpose specific sets of flume experiments, designed to identify the exact response of the particle resting at the bed surface for various below, near and above threshold flow conditions. New sets of measurements are presented for particle entrainment from a Lagrangian viewpoint. Further to finding direct application in addressing real world challenges in the water sector, it is shown that such novel sensor systems can also help the research community (both experimentalists and computational modellers) gain a better insight on the underlying processes governing granular dynamics.

  1. Entrainment Zone Characteristics and Entrainment Rates in Cloud-Topped Boundary Layers from DYCOMS-II

    Science.gov (United States)

    2012-03-01

    Malinowski , J. L. Brenguier, and F. Burnet, 2005: Holes and entrainment in stratocumulus. J. Atmos. Sci., 62, 443–459. Glickman, T. S...of the Entrainment Zone in Cloud-topped Boundary Layers. Department of Meteorology, NPS, 93 pp. Krzysztof, Haman E., S. P. Malinowski , M. J

  2. Evaluation of Co-precipitation Processes for the Synthesis of Mixed-Oxide Fuel Feedstock Materials

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Emory D [ORNL; Voit, Stewart L [ORNL; Vedder, Raymond James [ORNL

    2011-06-01

    The focus of this report is the evaluation of various co-precipitation processes for use in the synthesis of mixed oxide feedstock powders for the Ceramic Fuels Technology Area within the Fuels Cycle R&D (FCR&D) Program's Advanced Fuels Campaign. The evaluation will include a comparison with standard mechanical mixing of dry powders and as well as other co-conversion methods. The end result will be the down selection of a preferred sequence of co-precipitation process for the preparation of nuclear fuel feedstock materials to be used for comparison with other feedstock preparation methods. A review of the literature was done to identify potential nitrate-to-oxide co-conversion processes which have been applied to mixtures of uranium and plutonium to achieve recycle fuel homogeneity. Recent studies have begun to study the options for co-converting all of the plutonium and neptunium recovered from used nuclear fuels, together with appropriate portions of recovered uranium to produce the desired mixed oxide recycle fuel. The addition of recycled uranium will help reduce the safeguard attractiveness level and improve proliferation resistance of the recycled fuel. The inclusion of neptunium is primarily driven by its chemical similarity to plutonium, thus enabling a simple quick path to recycle. For recycle fuel to thermal-spectrum light water reactors (LWRs), the uranium concentration can be {approx}90% (wt.), and for fast spectrum reactors, the uranium concentration can typically exceed 70% (wt.). However, some of the co-conversion/recycle fuel fabrication processes being developed utilize a two-step process to reach the desired uranium concentration. In these processes, a 50-50 'master-mix' MOX powder is produced by the co-conversion process, and the uranium concentration is adjusted to the desired level for MOX fuel recycle by powder blending (milling) the 'master-mix' with depleted uranium oxide. In general, parameters that must be

  3. Bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.

    2013-01-01

    to describe the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. In this work both models consider the incoming solid fuel as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is treated as a 0D system, but the thermo......Because of the complexity to describe and solve thermo-chemical processes occurring in a fuel bed in grate-fired boiler, it is often necessary to simplify the process and use modeling techniques based on overall mass, energy and species conservation. A comparison between two numerical models......-chemical processes are divided in two successive sections: drying and conversion (which includes pyrolysis, gasification and combustion). The second model is an empirical 1D approach. The two models need input data such as composition, temperature and feeding rate of biomass and primary air. Temperature, species...

  4. Development of a model of entrained flow coal gasification and study of aerodynamic mechanisms of action on gasifier operation

    Science.gov (United States)

    Abaimov, N. A.; Ryzhkov, A. F.

    2015-11-01

    Problems requiring solution in development of modern highly efficient gasification reactor of a promising high power integrated gasification combined-cycle plant are formulated. The task of creating and testing a numerical model of an entrained-flow reactor for thermochemical conversion of pulverized coal is solved. The basic method of investigation is computational fluid dynamics. The submodel of thermochemical processes, including a single-stage scheme of volatile substances outlet and three heterogeneous reactions of carbon residue conversion (complete carbon oxidation, Boudouard reaction and hydrogasification), is given. The mass loss rate is determined according to the basic assumptions of the diffusion-kinetic theory. The equations applied for calculation of the process of outlet of volatile substances and three stages of fuel gasifi-cation (diffusion of reagent gas toward the surface of the coal particle, heterogeneous reactions of gas with carbon on its surface, and homogeneous reactions beyond the particle surface) are presented. The universal combined submodel Eddy Dissipation/Finite Rate Chemistry with standard (built-in) constants is used for numerical estimates. Aerodynamic mechanisms of action on thermochemical processes of solid fuel gasification are studied, as exemplified by the design upgrade of a cyclone reactor of preliminary thermal fuel preparation. Volume concentrations of combustible gases and products of complete combustion in the syngas before and after primary air and pulverized coal flows' redistribution are given. Volume concentrations of CO in syngas at different positions of tangential secondary air inlet nozzle are compared.

  5. Integrated process for the catalytic conversion of biomass-derived syngas into transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Vanessa Lebarbier; Smith, Colin; Flake, Matthew; Albrecht, Karl O.; Gray, Michel J.; Ramasamy, Karthikeyan K.; Dagle, Robert A.

    2016-01-01

    Efficient synthesis of renewable fuels that will enable cost competitiveness with petroleum-derived fuels remains a grand challenge for U.S. scientists. In this paper, we report on an integrated catalytic approach for producing transportation fuels from biomass-derived syngas. The composition of the resulting hydrocarbon fuel can be modulated to meet specified requirements. Biomass-derived syngas is first converted over an Rh-based catalyst into a complex aqueous mixture of condensable C2+ oxygenated compounds (predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate). This multi-component aqueous mixture then is fed to a second reactor loaded with a ZnxZryOz mixed oxide catalyst, which has tailored acid-base sites, to produce an olefin mixture rich in isobutene. The olefins then are oligomerized using a solid acid catalyst (e.g., Amberlyst-36) to form condensable olefins with molecular weights that can be targeted for gasoline, jet, and/or diesel fuel applications. The product rich in long-chain olefins (C7+) is finally sent to a fourth reactor that is needed for hydrogenation of the olefins into paraffin fuels. Simulated distillation of the hydrotreated oligomerized liquid product indicates that ~75% of the hydrocarbons present are in the jet-fuel range. Process optimization for the oligomerization step could further improve yield to the jet-fuel range. All of these catalytic steps have been demonstrated in sequence, thus providing proof-of-concept for a new integrated process for the production of drop-in biofuels. This unique and flexible process does not require external hydrogen and also could be applied to non-syngas derived feedstock, such as fermentation products (e.g., ethanol, acetic acid, etc.), other oxygenates, and mixtures thereof containing alcohols, acids, aldehydes and/or esters.

  6. Nonphotic entrainment of the human circadian pacemaker

    Science.gov (United States)

    Klerman, E. B.; Rimmer, D. W.; Dijk, D. J.; Kronauer, R. E.; Rizzo, J. F. 3rd; Czeisler, C. A.

    1998-01-01

    In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals "free run" even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

  7. On dust entrainment in photoevaporative winds

    Science.gov (United States)

    Hutchison, Mark A.; Price, Daniel J.; Laibe, Guillaume; Maddison, Sarah T.

    2016-09-01

    We investigate dust entrainment by photoevaporative winds in protoplanetary discs using dusty smoothed particle hydrodynamics. We use unequal-mass particles to resolve more than five orders of magnitude in disc/outflow density and a one-fluid formulation to efficiently simulate an equivalent magnitude range in drag stopping time. We find that only micron-sized dust grains and smaller can be entrained in extreme-UV radiation-driven winds. The maximum grain size is set by dust settling in the disc rather than aerodynamic drag in the wind. More generally, there is a linear relationship between the base flow density and the maximum entrainable grain size in the wind. A pileup of micron-sized dust grains can occur in the upper atmosphere at critical radii in the disc as grains decouple from the low-density wind. Entrainment is a strong function of location in the disc, resulting in a size sorting of grains in the outflow - the largest grain being carried out between 10 and 20 au. The peak dust density for each grain size occurs at the inner edge of its own entrainment region.

  8. Entrainment and the cranial rhythmic impulse.

    Science.gov (United States)

    McPartland, J M; Mein, E A

    1997-01-01

    Entrainment is the integration or harmonization of oscillators. All organisms pulsate with myriad electrical and mechanical rhythms. Many of these rhythms emanate from synchronized pulsating cells (eg, pacemaker cells, cortical neurons). The cranial rhythmic impulse is an oscillation recognized by many bodywork practitioners, but the functional origin of this impulse remains uncertain. We propose that the cranial rhythmic impulse is the palpable perception of entrainment, a harmonic frequency that incorporates the rhythms of multiple biological oscillators. It is derived primarily from signals between the sympathetic and parasympathetic nervous systems. Entrainment also arises between organisms. The harmonizing of coupled oscillators into a single, dominant frequency is called frequency-selective entrainment. We propose that this phenomenon is the modus operandi of practitioners who use the cranial rhythmic impulse in craniosacral treatment. Dominant entrainment is enhanced by "centering," a technique practiced by many healers, for example, practitioners of Chinese, Tibetan, and Ayurvedic medicine. We explore the connections between centering, the cranial rhythmic impulse, and craniosacral treatment.

  9. Fuel-Flexible Combustion System for Refinery and Chemical Plant Process Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Charles; Wilson, Robert

    2014-04-30

    This project culminated in the demonstration of a full-scale industrial burner which allows a broad range of “opportunity” gaseous fuels to be cost-effectively and efficiently utilized while generating minimal emissions of criteria air pollutants. The burner is capable of maintaining a stable flame when the fuel composition changes rapidly. This enhanced stability will contribute significantly to improving the safety and reliability of burner operation in manufacturing sites. Process heating in the refining and chemicals sectors is the primary application for this burner. The refining and chemical sectors account for more than 40% of total industrial natural gas use. Prior to the completion of this project, an enabling technology did not exist that would allow these energy-intensive industries to take full advantage of opportunity fuels and thereby reduce their natural gas consumption. Opportunity gaseous fuels include biogas (from animal and agricultural wastes, wastewater plants, and landfills) as well as syngas (from the gasification of biomass, municipal solid wastes, construction wastes, and refinery residuals). The primary challenge to using gaseous opportunity fuels is that their composition and combustion performance differ significantly from those of conventional fuels such as natural gas and refinery fuel gas. An effective fuel-flexible burner must accept fuels that range widely in quality and change in composition over time, often rapidly. In Phase 1 of this project, the team applied computational fluid dynamics analysis to optimize the prototype burner’s aerodynamic, combustion, heat transfer, and emissions performance. In Phase 2, full-scale testing and refinement of two prototype burners were conducted in test furnaces at Zeeco’s offices in Broken Arrow, OK. These tests demonstrated that the full range of conventional and opportunity fuels could be utilized by the project’s burner while achieving robust flame stability and very low levels of

  10. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process.

    Science.gov (United States)

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5-8.0, 27(±2°C and 10.6-18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery.

  11. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process.

    Directory of Open Access Journals (Sweden)

    Mohammad Danish Khan

    Full Text Available Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC which utilizes acid navy blue r (ANB dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE and power density (PD attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5-8.0, 27(±2°C and 10.6-18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity recovery.

  12. Fast signal processing of a yttrium-aluminum-perovskite:Ce detector for synchrotron x-ray experiments

    Science.gov (United States)

    Harada, Masaaki; Sakurai, Kenji; Saitoh, Kazuhiro; Kishimoto, Shunji

    2001-11-01

    An amplifier has been developed to form narrow pulses of less than 100 ns for a YAP:Ce scintillator, which appears promising as a detector for high-counting rate x-ray measurements. The performance of the detector system has been evaluated with monochromatic 8, 16.5, and 25 keV synchrotron x-ray photons at the Photon Factory. The whole deadtime obtained was 84 ns, which is around 3.5 times the decay time of the scintillation (25 ns), indicating that the present system is almost optimum. It has been found that the counting loss for 1 M counts/s is only 8%-9%, and that the detector can count extremely strong photons up to 5 M counts/s.

  13. /sup 238/Pu fuel form processes quarterly report, April-June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Folger, R. L.

    1980-06-01

    Savannah River Laboratory (SRL) completed the development of a production process to fabricate /sup 238/PuO/sub 2/ fuel forms for the GPHS. The fabrication flowsheet was based on a flowsheet originally developed at Los Alamos National Scientific Laboratory (LANSL). A summary report of the SRL process development effort is presented.

  14. Fuel and canister process report for the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Werme, Lars; Lilja, Christina (eds.)

    2010-12-15

    This report documents fuel and canister processes identified as relevant to the long-term safety of a KBS-3 repository. It forms an important part of the reporting of the safety assessment SR-Site. The detailed assessment methodology, including the role of the process reports in the assessment, is described in the SR-Site Main report /SKB 2011/

  15. Solar photochemical process engineering for production of fuels and chemicals

    Science.gov (United States)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1985-01-01

    The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6 percent are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6 percent. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.

  16. Novel materials process for alcohol based fuel cells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, K.; Smith, R.

    2005-07-01

    At present, the unit cost of producing alcohol fuel cells, in particular the cost of the ion-exchange membrane and the platinum catalyst, is limiting the sales. Since the cost of platinum cannot be reduced, an effective means of making the cells more attractive would be to increase the power output per unit area of membrane other than by operating at elevated temperatures. To replace the expensive Nafion, ITM and Cranfield University have developed a new membrane based on ionic hydrophilic polymers. Both acidic and alkaline-based membranes have been produced, the latter may well avoid the use of platinum thus gaining a further cost bonus. Conductivity of the new styrene-sulphonic acid graft membranes is more than double that of Nafion. Similarly, in cross-over tests, the new cells outperformed the Nafion cells. Palladium was investigated as a cheaper alternative to platinum. Based on this study, ITM have applied for five new patents. The study was conducted by ITM Power Plc under contract to the DTI.

  17. Effect of Mg2+ ions co-doping on luminescence and defects formation processes in Gd3(Ga,Al)5O12:Ce single crystals

    Science.gov (United States)

    Babin, V.; Bohacek, P.; Grigorjeva, L.; Kučera, M.; Nikl, M.; Zazubovich, S.; Zolotarjovs, A.

    2017-04-01

    Photo- and radioluminescence and thermally stimulated luminescence characteristics of Ce3+ - doped and Ce3+, Mg2+ co-doped Gd3(Ga,Al)5O12 (GAGG) single crystals of similar composition are investigated in the 9-500 K temperature range. The Ce3+ - related luminescence spectra and the photoluminescence decay kinetics in these crystals are found to be similar. Under photoexcitation in the Ce3+ - and Gd3+ - related absorption bands, no prominent rise of the photoluminescence intensity in time is observed neither in GAGG:Ce,Mg nor in GAGG:Ce crystals. The afterglow is strongly reduced in GAGG:Ce,Mg as compared to GAGG:Ce, and the afterglow decay kinetics is much faster. Co-doping with Mg2+ results in a drastic decrease of the thermally stimulated luminescence (TSL) intensity in the whole investigated temperature range and in the appearance of a new complex Mg2+ - related TSL glow curve peak around 285 K. After irradiation in the Ce3+ - related 3.6 eV absorption band, the TSL intensity in GAGG:Ce,Mg is found to be comparable with that in the GAGG:Ce epitaxial film of similar composition. The Mg2+ - induced changes in the concentration, origin and structure of the crystal lattice defects and their influence on the scintillation characteristics of GAGG:Ce,Mg are discussed.

  18. The importance of biotic entrainment for base flow fluvial sediment transport

    Science.gov (United States)

    Rice, Stephen P.; Johnson, Matthew F.; Mathers, Kate; Reeds, Jake; Extence, Chris

    2016-05-01

    Sediment transport is regarded as an abiotic process driven by geophysical energy, but zoogeomorphological activity indicates that biological energy can also fuel sediment movements. It is therefore prudent to measure the contribution that biota make to sediment transport, but comparisons of abiotic and biotic sediment fluxes are rare. For a stream in the UK, the contribution of crayfish bioturbation to suspended sediment flux was compared with the amount of sediment moved by hydraulic forcing. During base flow periods, biotic fluxes can be isolated because nocturnal crayfish activity drives diel turbidity cycles, such that nighttime increases above daytime lows are attributable to sediment suspension by crayfish. On average, crayfish bioturbation contributed at least 32% (474 kg) to monthly base flow suspended sediment loads; this biotic surcharge added between 5.1 and 16.1 t (0.21 to 0.66 t km-2 yr-1) to the annual sediment yield. As anticipated, most sediment was moved by hydraulic forcing during floods and the biotic contribution from baseflow periods represented between 0.46 and 1.46% of the annual load. Crayfish activity is nonetheless an important impact during baseflow periods and the measured annual contribution may be a conservative estimate because of unusually prolonged flooding during the measurement period. In addition to direct sediment entrainment by bioturbation, crayfish burrowing supplies sediment to the channel for mobilization during floods so that the total biotic effect of crayfish is potentially greater than documented in this study. These results suggest that in rivers, during base flow periods, bioturbation can entrain significant quantities of fine sediment into suspension with implications for the aquatic ecosystem and base flow sediment fluxes. Energy from life rather than from elevation can make significant contributions to sediment fluxes.

  19. CONCEPTUAL PROCESS DESCRIPTION FOR THE MANUFACTURE OF LOW-ENRICHED URANIUM-MOLYBDENUM FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Daniel M. Wachs; Curtis R. Clark; Randall J. Dunavant

    2008-02-01

    The National Nuclear Security Agency Global Threat Reduction Initiative (GTRI) is tasked with minimizing the use of high-enriched uranium (HEU) worldwide. A key component of that effort is the conversion of research reactors from HEU to low-enriched uranium (LEU) fuels. The GTRI Convert Fuel Development program, previously known as the Reduced Enrichment for Research and Test Reactors program was initiated in 1978 by the United States Department of Energy to develop the nuclear fuels necessary to enable these conversions. The program cooperates with the research reactors’ operators to achieve this goal of HEU to LEU conversion without reduction in reactor performance. The programmatic mandate is to complete the conversion of all civilian domestic research reactors by 2014. These reactors include the five domestic high-performance research reactors (HPRR), namely: the High Flux Isotope Reactor at the Oak Ridge National Laboratory, the Advanced Test Reactor at the Idaho National Laboratory, the National Bureau of Standards Reactor at the National Institute of Standards and Technology, the Missouri University Research Reactor at the University of Missouri–Columbia, and the MIT Reactor-II at the Massachusetts Institute of Technology. Characteristics for each of the HPRRs are given in Appendix A. The GTRI Convert Fuel Development program is currently engaged in the development of a novel nuclear fuel that will enable these conversions. The fuel design is based on a monolithic fuel meat (made from a uranium-molybdenum alloy) clad in Al-6061 that has shown excellent performance in irradiation testing. The unique aspects of the fuel design, however, necessitate the development and implementation of new fabrication techniques and, thus, establishment of the infrastructure to ensure adequate fuel fabrication capability. A conceptual fabrication process description and rough estimates of the total facility throughput are described in this document as a basis for

  20. Improved Laboratory Transition Probabilities for Ce II, Application to the Cerium Abundances of the Sun and Five r-process Rich, Metal-Poor Stars, and Rare Earth Lab Data

    CERN Document Server

    Lawler, J E; Cowan, J J; Ivans, I I; Hartog, E A Den

    2009-01-01

    Recent radiative lifetime measurements accurate to +/- 5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce II have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of Ce II. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log epsilon = 1.61 +/- 0.01 (sigma = 0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log epsilon = 1.61 +/- 0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17 3248, CS 22892-052, CS 31082-001, HD 115444 and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of 0.01 dex similar to the Solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process ...

  1. Effects of Catalysts on Emissions of Pollutants from Combustion Processes of Liquid Fuels

    Science.gov (United States)

    Bok, Agnieszka; Guziałowska-Tic, Joanna; Tic, Wilhelm Jan

    2014-12-01

    The dynamic growth of the use of non-renewable fuels for energy purposes results in demand for catalysts to improve their combustion process. The paper describes catalysts used mainly in the processes of combustion of motor fuels and fuel oils. These catalysts make it possible to raise the efficiency of oxidation processes simultanously reducing the emission of pollutants. The key to success is the selection of catalyst compounds that will reduce harmful emissions of combustion products into the atmosphere. Catalysts are introduced into the combustion zone in form of solutions miscible with fuel or with air supplied to the combustion process. The following compounds soluble in fuel are inclused in the composition of the described catalysts: organometallic complexes, manganese compounds, salts originated from organic acids, ferrocen and its derivatives and sodium chloride and magnesium chloride responsible for burning the soot (chlorides). The priority is to minimize emissions of volatile organic compounds, nitrogen oxides, sulphur oxides, and carbon monoxide, as well as particulate matter.

  2. Structure study of BaCe0.85Y0.15O3-Δ as solid state fuel cell material

    Science.gov (United States)

    Krezhov, K.; Vladikova, D.; Raikova, G.; Genov, I.; Malakova, T.; Dimitrov, D.; Svab, E.; Fabian, M.

    2016-03-01

    The structural details of powder, dense and porous samples of BaCe0.85Y0.15O3-δ (BCY15) used recently in an innovative monolithic design of SOFC were studied from multiple Rietveld analysis of neutron and x-ray diffraction patterns. The 3-layered monolithic assembly built from BCY15 material works as oxide ion conductor in the oxygen space, as proton conductor in the hydrogen area and as mixed conductor in the central membrane. We find that in all the samples of studied BCY15 based materials there are no indications of difference in crystallographic symmetry and the structure refinements did produce best agreement factors in orthorhombic Pnma space group.

  3. Numerical Modeling of Deep Mantle Flow: Thermochemical Convection and Entrainment

    Science.gov (United States)

    Mulyukova, Elvira; Steinberger, Bernhard; Dabrowski, Marcin; Sobolev, Stephan

    2013-04-01

    ) upwelling of the ambient material in the vicinity of the dense material (mechanism of selective withdrawal (Lister, 1989)), and (iii) cold downwellings sliding along the bottom boundary, and forcing the dense material upwards. The objective of this study is to compare the efficiency of entrainment by each of these mechanisms, and its dependence on the density and viscosity anomaly of the dense material with respect to the ambient mantle. To perform this study, we have developed a two-dimensional FEM code to model thermal convection in a hollow cylinder domain with presence of chemical heterogeneities, and using a realistic viscosity profile. We present the results of the simulations that demonstrate the entrainment mechanisms described above. In addition, we perfom numerical experiments in a Cartesian box domain, where the bottom right boundary of the box is deformed to resemble the geometry of an LLSVP edge. In some of the experiments, the bottom left part of the boundary is moving towards the right boundary, simulating a slab sliding along the core-mantle boundary towards an LLSVP. These experiments allow a detailed study of the process of entrainment, and its role in the thermochemical evolution of the Earth.

  4. Food entrainment: major and recent findings.

    Science.gov (United States)

    Carneiro, Breno T S; Araujo, John F

    2012-01-01

    Mammals exhibit daily anticipatory activity to cycles of food availability. Studies on such food anticipatory activity (FAA) have been conducted mainly in nocturnal rodents. They have identified FAA as the behavioral output of a food entrained oscillator (FEO), separate of the known light entrained oscillator (LEO) located in the suprachiasmatic nucleus (SCN) of hypothalamus. Here we briefly review the main characteristics of FAA. Also, we present results on four topics of food anticipation: (1) possible input signals to FEO, (2) FEO substrate, (3) the importance of canonical clock genes for FAA, and (4) potential practical applications of scheduled feeding. This mini review is intended to introduce the subject of food entrainment to those unfamiliar with it but also present them with relevant new findings on the issue.

  5. Food entrainment: major and recent findings

    Directory of Open Access Journals (Sweden)

    Breno Tercio Santos Carneiro

    2012-11-01

    Full Text Available Mammals exhibit daily anticipatory activity to cycles of food availability. Studies on such food anticipatory activity (FAA have been conducted mainly in nocturnal rodents. They have identified FAA as the behavioral output of a food entrained oscillator (FEO, separate of the known light entrained oscillator (LEO located in the suprachiasmatic nucleus of hypothalamus (SCN. Here we briefly review the main characteristics of FAA. Also, we present results on four topics of food anticipation: (1 possible input signals to FEO, (2 FEO substrate, (3 the importance of canonical clock genes for FAA and (4 potential practical applications of scheduled feeding. This mini review is intended to introduce the subject of food entrainment to those unfamiliar with it but also present them with relevant new findings on the issue.

  6. High temperature air-blown woody biomass gasification model for the estimation of an entrained down-flow gasifier.

    Science.gov (United States)

    Kobayashi, Nobusuke; Tanaka, Miku; Piao, Guilin; Kobayashi, Jun; Hatano, Shigenobu; Itaya, Yoshinori; Mori, Shigekatsu

    2009-01-01

    A high temperature air-blown gasification model for woody biomass is developed based on an air-blown gasification experiment. A high temperature air-blown gasification experiment on woody biomass in an entrained down-flow gasifier is carried out, and then the simple gasification model is developed based on the experimental results. In the experiment, air-blown gasification is conducted to demonstrate the behavior of this process. Pulverized wood is used as the gasification fuel, which is injected directly into the entrained down-flow gasifier by the pulverized wood banner. The pulverized wood is sieved through 60 mesh and supplied at rates of 19 and 27kg/h. The oxygen-carbon molar ratio (O/C) is employed as the operational condition instead of the air ratio. The maximum temperature achievable is over 1400K when the O/C is from 1.26 to 1.84. The results show that the gas composition is followed by the CO-shift reaction equilibrium. Therefore, the air-blown gasification model is developed based on the CO-shift reaction equilibrium. The simple gasification model agrees well with the experimental results. From calculations in large-scale units, the cold gas is able to achieve 80% efficiency in the air-blown gasification, when the woody biomass feedrate is over 1000kg/h and input air temperature is 700K.

  7. NSRR experiment with un-irradiated uranium-zirconium hydride fuel. Design, fabrication process and inspection data of test fuel rod

    Energy Technology Data Exchange (ETDEWEB)

    Sasajima, Hideo; Fuketa, Toyoshi; Ishijima, Kiyomi; Kuroha, Hiroshi; Ikeda, Yoshikazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Aizawa, Keiichi

    1998-08-01

    An experiment plan is progressing in the Nuclear Safety Research Reactor (NSRR) to perform pulse-irradiation with uranium-zirconium hydride (U-ZrH{sub x}) fuel. This fuel is widely used in the training research and isotope production reactor of GA (TRIGA). The objectives of the experiment are to determine the fuel rod failure threshold and to investigate fuel behavior under simulated reactivity initiated accident (RIA) conditions. This report summarizes design, fabrication process and inspection data of the test fuel rods before pulse-irradiation. The experiment with U-ZrH{sub x} fuel will realize precise safety evaluation, and improve the TRIGA reactor performance. The data to be obtained in this program will also contribute development of next-generation TRIGA reactor and its safety evaluation. (author)

  8. Pyro-chemistry within Europart assessment of the studies on spent fuel treatment processes collective work

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, S. [CEA Valrho, 30 - Marcoule (France); Madic, C. [CEA Saclay, 91 - Gif sur Yvette (France); Caravaca, C. [CIEMAT (Spain); Finne, J. [Electricite de France (EDF), 75 - Paris (France); Angelis, G. de [ENEA, Bologna (Italy); Malmbeck, R. [ITU, JRC (Germany); Lewin, B.G. [NEXIA Solutions (United Kingdom); Uhlir, J. [Nuclear Research Institute (NRI) (Czech Republic); Inoue, T. [CRIEPI (Japan); Luca, V. [ANSTO (Australia)

    2007-07-01

    In the continuation of PYROREP (FP5), the pyrochemical domain of EUROPART (FP6) involves today 7 European participants and 2 international partners in order to assess treatment processes which could be used in a broad variety of fuel cycles: molten salt reactor spent fuel, metallic, oxide, carbide or nitride fuels from any reactors. Indeed, a pyrochemical process is not sensitive to radiolysis, and obviously to temperature effects, and could afford to treat fuels after a short cooling period, even at high concentrations. Within EUROPART, the chemistry of actinides and of some fission products was studied in depth in either chloride or fluoride molten salts. Laboratory-scale demonstration experiments were used in order to assess electrolytic processes in molten chlorides and liquid-liquid reductive extraction in molten fluoride/liquid aluminum. An electrolysis process is also under development in molten fluoride. To complete the studies, the development of devices and the modeling of processes are taken into consideration. In order to be fitted for acceptance, a process has to produce minimal quantities of wastes, compatible with storage constraints. Therefore, decontamination techniques, as well as materials suitable for disposal, have to be developed. Fission products precipitation by carbonate and phosphate, and filtration on zeolites were studied. Some original confinement matrices such as sodalite or pollucite were also studied. Integration studies have been carried out in order to evaluate and to compare some selected process flowsheets and possibly to redirect development programs. (authors)

  9. Biorefineries to integrate fuel, energy and chemical production processes

    Directory of Open Access Journals (Sweden)

    Enrica Bargiacchi

    2007-12-01

    Full Text Available The world of renewable energies is in fast evolution and arouses political and public interests, especially as an opportunity to boost environmental sustainability by mitigation of greenhouse gas emissions. This work aims at examining the possibilities related to the development of biorefineries, where biomass conversion processes to produce biofuels, electricity and biochemicals are integrated. Particular interest is given to the production processes of biodiesel, bioethanol and biogas, for which present world situation, problems, and perspectives are drawn. Potential areas for agronomic and biotech researches are also discussed. Producing biomass for biorefinery processing will eventually lead to maximize yields, in the non food agriculture.

  10. Aqueous processing of U-10Mo scrap for high performance research reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J., E-mail: youker@anl.gov [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Stepinski, Dominique C.; Maggos, Laura E.; Bakel, Allen J.; Vandegrift, George F. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer GTRI program supports conversion from HEU to LEU. Black-Right-Pointing-Pointer High performance research reactors require a dense LEU fuel such as U-10Mo foils. Black-Right-Pointing-Pointer Dissolution conditions for U-10Mo foils in acidic media have been optimized. Black-Right-Pointing-Pointer Solvent-extraction processing can be used to recover U lost in fuel fabrication. Black-Right-Pointing-Pointer Flowsheets were developed using Argonne-design contactors but other contactors can be used as well. - Abstract: The Global Threat Reduction Initiative (GTRI) Conversion program, which is part of the US government's National Nuclear Security Administration (NNSA), supports the conversion of civilian use of highly enriched uranium (HEU) to low enriched uranium (LEU) for reactor fuel and targets. The reason for conversion is to eliminate the use of any material that may pose a threat to the United States or other foreign countries. High performance research reactors (HPRRs) cannot make the conversion to a standard LEU fuel because they require a more dense fuel to meet their performance requirements. As a result, a more dense fuel consisting of a monolithic uranium-molybdenum alloy containing 10% (w/w) Mo with Al cladding and a Zr bonding-layer is being considered. Significant losses are expected in the fabrication of this fuel, so a means to recycle the scrap pieces is needed. Argonne National Laboratory has developed an aqueous-processing flowsheet for scrap recovery in the fuel fabrication process for high-density LEU-monolithic fuel based on data found in the literature. Experiments have been performed to investigate dissolution conditions for solutions containing approximately 20 g-U/L and 50 g-U/L with and without Fe(NO{sub 3}){sub 3}. HNO{sub 3} and HF concentrations have been optimized for timely dissolution of the fuel scrap and prevention of the formation of the U-Zr{sub 2} intermetallic, explosive complex, while

  11. Low Emissions Burner Technology for Metal Processing Industry using Byproducts and Biomass Derived Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

    path forward to utilize both fossil and alternative liquid fuels in the same combustion system. In particular, experiments show that straight VO can be cleanly combusted without the need for chemical processing or preheating steps, which can result in significant economic and environmental benefits. Next, low-emission combustion of glycerol/methane was achieved by utilizing FB injector to yield fine droplets of highly viscous glycerol. Heat released from methane combustion further improves glycerol pre-vaporization and thus its clean combustion. Methane addition results in an intensified reaction zone with locally high temperatures near the injector exit. Reduction in methane flow rate elongates the reaction zone, which leads to higher CO emissions and lower NOx emissions. Similarly, higher air to liquid (ALR) mass ratio improves atomization and fuel pre-vaporization and shifts the flame closer to the injector exit. In spite of these internal variations, all fuel mixes of glycerol with methane produced similar CO and NOx emissions at the combustor exit. Results show that FB concept provides low emissions with the flexibility to utilize gaseous and highly viscous liquid fuels, straight VO and glycerol, without preheating or preprocessing the fuels. Following these initial experiments in quartz combustor, we demonstrated that glycerol combustion can be stably sustained in a metal combustor. Phase Doppler Particle Analyzer (PDPA) measurements in glycerol/methane flames resulted in flow-weighted Sauter Mean Diameter (SMD) of 35 to 40 μm, depending upon the methane percentage. This study verified that lab-scale dual-fuel burner using FB injector can successfully atomize and combust glycerol and presumably other highly viscous liquid fuels at relatively low HRR (<10 kW). For industrial applications, a scaled-up glycerol burner design thus seemed feasible.

  12. Catalysts and process for liquid hydrocarbon fuel production

    Energy Technology Data Exchange (ETDEWEB)

    White, Mark G.; Ranaweera, Samantha A.; Henry, William P.

    2016-08-02

    The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality distillates, gasoline components, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel supported bimetallic ion complex catalyst for conversion, and provides methods of preparing such novel catalysts and use of the novel catalysts in the process and system of the invention.

  13. Fabrication and characterization of a tubular ceramic fuel cell based on BaZr0.1Ce0.7Y0.1Yb0.1O3-δ proton conducting electrolyte

    Science.gov (United States)

    Hanifi, Amir Reza; Sandhu, Navjot Kaur; Etsell, Thomas H.; Luo, Jing-Li; Sarkar, Partha

    2017-02-01

    A proton conducting anode supported tubular fuel cell is fabricated in this research using the highly proton conductive BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte. The cell is in a Ni-BZCYYb/BZCYYb/LSCF-BZCYYb configuration consisting of a support, electrolyte and cathode with thicknesses of 680 μm, 25 μm and 90 μm, respectively. The cell delivers maximum power densities of 331, 362 and 416 mW/cm2 at 600, 650 and 700 °C, respectively. AC impedance spectroscopy results show values of 0.94 Ω.cm2, 0.73 Ω.cm2, and 0.60 Ω.cm2 for total resistance at the corresponding temperatures while the major resistance contributor is the ohmic resistance. The Ni-BZCYYb anode microstructure shows detachment of Ni and the BZCYYb in most regions as well as pores inside the Ni grains. Despite the low anode porosity (25%), the cell gives a very low concentration polarization value (0.05 Ω.cm2) indicating that the fuel gas could readily diffuse into the microstructure. This might be attributed to water forming on the cathode side, which masks the necessity of having a high porosity anode. The cell fails when tested under CO:H2 of 1:1 at 700 °C due to significant carbon (graphite) formation indicating that proton conductors based on barium cerates are not appropriate choices for application under hydrocarbon fuels.

  14. Neural entrainment to rhythmically-presented auditory, visual and audio-visual speech in children

    Directory of Open Access Journals (Sweden)

    Alan James Power

    2012-07-01

    Full Text Available Auditory cortical oscillations have been proposed to play an important role in speech perception. It is suggested that the brain may take temporal ‘samples’ of information from the speech stream at different rates, phase-resetting ongoing oscillations so that they are aligned with similar frequency bands in the input (‘phase locking’. Information from these frequency bands is then bound together for speech perception. To date, there are no explorations of neural phase-locking and entrainment to speech input in children. However, it is clear from studies of language acquisition that infants use both visual speech information and auditory speech information in learning. In order to study neural entrainment to speech in typically-developing children, we use a rhythmic entrainment paradigm (underlying 2 Hz or delta rate based on repetition of the syllable ba, presented in either the auditory modality alone, the visual modality alone, or as auditory-visual speech (via a talking head. To ensure attention to the task, children aged 13 years were asked to press a button as fast as possible when the ba stimulus violated the rhythm for each stream type. Rhythmic violation depended on delaying the occurrence of a ba in the isochronous stream. Neural entrainment was demonstrated for all stream types, and individual differences in standardized measures of language processing were related to auditory entrainment at the theta rate. Further, there was significant modulation of the preferred phase of auditory entrainment in the theta band when visual speech cues were present, indicating cross-modal phase resetting. The rhythmic entrainment paradigm developed here offers a method for exploring individual differences in oscillatory phase locking during development. In particular, a method for assessing neural entrainment and cross-modal phase resetting would be useful for exploring developmental learning difficulties thought to involve temporal sampling

  15. Catalysts and process for liquid hydrocarbon fuel production

    Science.gov (United States)

    White, Mark G; Liu, Shetian

    2014-12-09

    The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality gasoline components, aromatic compounds, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel molybdenum-zeolite catalyst in high pressure hydrogen for conversion, as well as a novel rhenium-zeolite catalyst in place of the molybdenum-zeolite catalyst, and provides for use of the novel catalysts in the process and system of the invention.

  16. EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL

    Science.gov (United States)

    The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

  17. Microchemical Systems for Fuel Processing and Conversion to Electrical Power

    Science.gov (United States)

    2007-03-15

    6.8 Vacuum Packaging ........................................................................................................................................43...production may take place. Vacuum packaging and reflective shields, required to maximize the thermal isolation of the reaction zone, have been tested...microfabrication strategies. Substantial effort has been expended on the chip level vacuum packaging process, which is critical to the performance of the

  18. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2004-09-01

    An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

  19. Fuel decomposition and boundary-layer combustion processes of hybrid rocket motors

    Science.gov (United States)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated Polybutadiene) fuel cross-linked with diisocyanate was burned with GOX under various operating conditions. Large-amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed-line system and combustion chamber, the pressure oscillations were drastically reduced from +/-20% of the localized mean pressure to an acceptable range of +/-1.5% Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations are thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real-time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thickness burned and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented.

  20. Innovative Fresh Water Production Process for Fossil Fuel Plants

    Energy Technology Data Exchange (ETDEWEB)

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight; Venugopal Jogi

    2005-09-01

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A dynamic analysis of heat and mass transfer demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3 Hg. The optimum operating condition for the DDD process with a high temperature of 50 C and sink temperature of 25 C has an air mass flux of 1.5 kg/m{sup 2}-s, air to feed water mass flow ratio of 1 in the diffusion tower, and a fresh water to air mass flow ratio of 2 in the condenser. Operating at these conditions yields a fresh water production efficiency (m{sub fW}/m{sub L}) of 0.031 and electric energy consumption rate of 0.0023 kW-hr/kg{sub fW}. Throughout the past year, the main focus of the desalination process has been on the direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. The analyses agree quite well with the current data. Recently, it has been recognized that the fresh water production efficiency can be significantly enhanced with air heating. This type of configuration is well suited for power plants utilizing air-cooled condensers. The experimental DDD facility has been modified with an air heating section, and temperature and humidity data have been collected over a range of flow and thermal conditions. It has been experimentally observed that the fresh water production rate is enhanced when air

  1. Innovative Fresh Water Production Process for Fossil Fuel Plants

    Energy Technology Data Exchange (ETDEWEB)

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2006-09-29

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report summarizes the progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. Detailed heat and mass transfer analyses required to size and analyze the diffusion tower using a heated water input are described. The analyses agree quite well with the current data and the information available in the literature. The direct contact condenser has also been thoroughly analyzed and the system performance at optimal operating conditions has been considered using a heated water/ambient air input to the diffusion tower. The diffusion tower has also been analyzed using a heated air input. The DDD laboratory facility has successfully been modified to include an air heating section. Experiments have been conducted over a range of parameters for two different cases: heated air/heated water and heated air/ambient water. A theoretical heat and mass transfer model has been examined for both of these cases and agreement between the experimental and theoretical data is good. A parametric study reveals that for every liquid mass flux there is an air mass flux value where the diffusion tower energy consumption is minimal and an air mass flux where the fresh water production flux is maximized. A study was also performed to compare the DDD process with different inlet operating conditions as well as different packing. It is shown that the heated air/heated water case is more capable of greater fresh water production with the same energy consumption than the ambient air/heated water process at high liquid mass flux. It is also shown that there can be

  2. Solvent degradation products in nuclear fuel processing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shook, H.E. Jr.

    1988-06-01

    The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

  3. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    James F. Klausner; Renwei Mei; Yi Li; Mohamed Darwish; Diego Acevedo; Jessica Knight

    2003-09-01

    This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system, which is powered by the waste heat from low pressure condensing steam in power plants. The desalination is driven by water vapor saturating dry air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. A thermodynamic analysis demonstrates that the DDD process can yield a fresh water production efficiency of 4.5% based on a feed water inlet temperature of only 50 C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day. The main focus of the initial development of the desalination process has been on the diffusion tower. A detailed mathematical model for the diffusion tower has been described, and its numerical implementation has been used to characterize its performance and provide guidance for design. The analysis has been used to design a laboratory scale diffusion tower, which has been thoroughly instrumented to allow detailed measurements of heat and mass transfer coefficient, as well as fresh water production efficiency. The experimental facility has been described in detail.

  4. Laminar Entrained Flow Reactor (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-02-01

    The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

  5. Air entrainment by plunging water jets

    NARCIS (Netherlands)

    Van de Sande, E.

    1974-01-01

    Gas entrainment caused by the impact of liquid jets upon liquid pool surfaces is a subject which has received too little attention. This well-known phenomenon,which occurs In nature and in numerous industrial operations, has only recently received interest from scientific workers. The influence on p

  6. Washing of the AW-101 entrained solids

    Energy Technology Data Exchange (ETDEWEB)

    GJ Lumetta

    2000-03-31

    BNFL Inc. (BNFL) is under contract with the US Department of Energy, River Protection Project (DOE-RPP) to design, construct, and operate facilities for treating wastes stored in the single-shell and double-shell tanks at the Hanford Site, Richland, Washington. The DOE-BNFL RPP contract identifies two feeds to the waste treatment plant: (1) primarily liquid low-activity waste (LAW) consisting of less than 2 wt% entrained solids and (2) high-level waste (HLW) consisting of 10 to 200 g/L solids slurry. This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing on the composition of the entrained solids in the diluted AW-101 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AW-101 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching. The work was conducted according to test plan BNFL-TP-29953-9, Rev. 0, LAW Entrained Solids Water Wash and Caustic Leach Testing. The test went according to plan, with no deviations from the test plan. Based on the results of the 0.01 M NaOH washing, a decision was made by BNFL to not proceed with the caustic leaching test. The composition of the washed solids was such that caustic leaching would not result in significant reduction in the immobilized HLW volume.

  7. Drugs of Abuse Can Entrain Circadian Rhythms

    Directory of Open Access Journals (Sweden)

    Ann E. K. Kosobud

    2007-01-01

    Full Text Available Circadian rhythms prepare organisms for predictable events during the Earth's 24-h day. These rhythms are entrained by a variety of stimuli. Light is the most ubiquitous and best known zeitgeber, but a number of others have been identified, including food, social cues, locomotor activity, and, most recently drugs of abuse. Given the diversity of zeitgebers, it is probably not surprising that genes capable of clock functions are located throughout almost all organs and tissues. Recent evidence suggests that drugs of abuse can directly entrain some circadian rhythms. We have report here that entrainment by drugs of abuse is independent of the suprachiasmatic nucleus and the light/dark cycle, is not dependent on direct locomotor stimulation, and is shared by a variety of classes of drugs of abuse. We suggest that drug-entrained rhythms reflect variations in underlying neurophysiological states. This could be the basis for known daily variations in drug metabolism, tolerance, and sensitivity to drug reward. These rhythms could also take the form of daily periods of increased motivation to seek and take drugs, and thus contribute to abuse, addiction and relapse.

  8. Study on new BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} composite electrolytes for intermediate-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fengguang; Dang, Junjie; Hou, Jie; Qian, Jing; Zhu, Zhiwen; Wang, Zhongtao [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Liu, Wei, E-mail: wliu@ustc.edu.cn [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-08-05

    Highlights: • New BCI–GDC composite electrolytes were synthesized using a one-step method for SOFCs. • The sintering temperature decreases as the BCI content increases. • The conductivity and OCV values enhanced as the GDC content increases. • The possible interface effects between BCI and GDC were analyzed. - Abstract: New mixed ionic conductors, BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} (BCI–GDC, weight ratio, 3:7, 5:5 and 7:3), were synthesized via a one-step citric acid–nitrate gel combustion method as electrolyte materials for solid oxide fuel cells (SOFCs). X-ray diffraction patterns of BCI–GDC indicated that there was no impurity phase formed after sintering at high temperature up to 1400 °C. Scanning electron microscopic study of BCI–GDC depicted dense grain morphology. Single fuel cells were prepared and the corresponding electrochemical performances were tested. The sintering temperature of the dense composite electrolyte membranes decrease as the BCI content increases because of the sintering aids of In element. All samples with the composite electrolyte showed higher open circuit voltage (OCV) values than the single phase GDC. In addition, Electrical conductivity of the composite electrolyte under different atmospheres at different temperatures confirmed that the BCI–GDC exhibited high mixed oxygen ionic and protonic conduction. The test results indicated that the conductivity and OCV values of the composite electrolyte enhanced as the GDC content increases, and the optimum performance was found to be BCI3–GDC7 compared with the pure BCI and GDC electrolyte. The possible interface effects were suggested to explain this phenomenon. Our results not only provide one new promising composite electrolyte material for intermediate-temperature SOFCs but the composition dependence can actually provide a guide for the material design, optimization.

  9. /sup 238/Pu fuel form processes. Quarterly report, July-September 1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-04-01

    This report is one of a series to summarize progress in the Savannah River Laboratory /sup 238/Pu Fuel Form Program. Goals of the Savannah River Laboratory (SRL) program include providing technical support for the production of /sup 238/PuO/sub 2/ fuel forms in the Savannah River Plant's (SRP) Plutonium Fuel Form (PuFF) Facility. This part of the program includes: demonstration of processes and techniques developed by the Los Alamos National Laboratory (LANL) for production at SRP. Information from the demonstration will provide the technical data for technical standards and operating procedures; technical support to assist plant startup and to ensure continuation of safe and efficient production of high-quality heat-source fuel; and technical assistance after startup to accommodate changes in product and product specifications, to assist user agencies in improving product performance, to assist SRP in making process improvements that increase efficiency and product reliability, and to adapt plant facilities for new products. This report summarizes progress in improving the quality of welds in /sup 238/PuO/sub 2/ fuel capsules.

  10. Fuel pellets from biomass - Processing, bonding, raw materials

    Energy Technology Data Exchange (ETDEWEB)

    Stelte, W.

    2011-12-15

    The present study investigates several important aspects of biomass pelletization. Seven individual studies have been conducted and linked together, in order to push forward the research frontier of biomass pelletization processes. The first study was to investigate influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding mechanisms within a biomass pellet, which indicate that different mechanisms are involved depending on biomass type and pelletizing conditions. Interpenetration of polymer chains and close intermolecular distance resulting in better secondary bonding were assumed to be the key factors for high mechanical properties of the formed pellets. The outcome of this study resulted in study four and five investigating the role of lignin glass transition for biomass pelletization. It was demonstrated that the softening temperature of lignin was dependent on species and moisture content. In typical processing conditions and at 8% (wt) moisture content, transitions were identified to be at approximately 53-63 deg. C for wheat straw and about 91 deg. C for spruce lignin. Furthermore, the effects of wheat straw extractives on the pelletizing properties and pellet stability were investigated. The sixth and seventh study applied the developed methodology to test the pelletizing properties of thermally pre-treated (torrefied) biomass from spruce and wheat straw. The results indicated that high torrefaction temperatures above 275 deg

  11. Process Improvements to Biomass Pretreatment of Fuels and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Teymouri, Farzaneh [Michigan Biotechnology Inst., Lansing, MI (United States)

    2015-05-30

    MBI, a 501c(3) company focusing on de-risking and scaling up bio-based technologies, has teamed with Michigan State University and the Idaho National Laboratory to develop and demonstrate process improvements to the ammonia fiber expansion (AFEX) pretreatment process. The logistical hurdles of biomass handling are well known, and the regional depot concept - in which small, distributed bioprocessing operations collect, preprocess, and densify biomass before shipping to a centralized refinery - is a promising alternative to centralized collection. AFEXTM (AFEX is a trademark of MBI) has unique features among pretreatments that would make it desirable as a pretreatment prior to densification at the depot scale. MBI has developed a novel design, using a packed bed reactor for the AFEX process that can be scaled down economically to the depot scale at a lower capital cost as compared to the traditional design (Pandia type reactor). Thus, the purpose of this project was to develop, scale-up, demonstrate, and improve this novel design The key challenges are the recovery of ammonia, consistent and complete pretreatment performance, and the overall throughput of the reactor. In this project an engineering scale packed bed AFEX system with 1-ton per day capacity was installed at MBI’s building. The system has been operational since mid-2013. During that time, MBI has demonstrated the robustness, reliability, and consistency of the process. To date, nearly 500 runs have been performed in the reactors. There have been no incidences of plugging (i.e., inability to remove ammonia from biomass after the treatment), nor has there been any instance of a major ammonia release into the atmosphere. Likewise, the sugar released via enzyme hydrolysis has remained consistent throughout these runs. Our economic model shows a 46% reduction in AFEX capital cost at the 100 ton/day scale compared to the traditional design of AFEX (Pandia type reactor). The key performance factors were

  12. Kiln process impact of alternative solid fuel combustion in the cement kiln main burner - Mathematical modelling and full-scale experiment

    OpenAIRE

    Ariyaratne, Hiromi Wijesinghe; Melaaen, Morten Christian; Tokheim, Lars André; Manjula, Edirisinghe V. P. J.

    2014-01-01

    Increased use of alternative fuels in cement kilns is a trend in the world. However, replacing fossil fuels like coal with different alternative fuels will give various impacts on the overall kiln process due to the fuel characteristics. Hence, it is important to know to what extent the fossil fuels can be replaced by different alternative fuels without severely changing process conditions, product quality or emissions. In the present study, a mass and energy balance for the combustion of dif...

  13. Processing of waste to solid fuel (SFS-standard); Jaetteen jalostaminen kiinteaeksi polttoaineeksi (SFS-Standardi)

    Energy Technology Data Exchange (ETDEWEB)

    Juvonen, J. [VTT Energia, Espoo (Finland)

    1999-07-01

    The objective of this project is to prepare, based on the Quality Assurance Manual for Recovered Fuels, a SFS-standard 'Processing of waste to solid fuel'. The fundamentals for safe energy use in co-combustion will be stated in the standard. The standard unifies the terminology and contributes to equation of recovered fuels with other solid fuels. The work is prepared by an expert group of about twenty persons. Juhani Juvonen, Research Scientist, VTT Energy, acts as the author of the proposal and the technical secretary of the expert group. Other group members help in preparing the work as experts of their domain. The expert group introduces the proposal for the standardization committee, which processes and comments the proposal at its own meetings. The standard proposal is processed, until it is ready for circulation among different interest groups. The statements will be processed both in the expert group and the standardization committee, after which the standard will be revised to be send to SFS to be approved as SFS standard. The work on standardization was started in 1998 and the first practical actions were taken on 24 September 1998 at a meeting held in the General Industry Federation (YTL). The preliminary objective is to have the standard approved during the year 1999. (orig.)

  14. Membrane-integrated oxy-fuel combustion of coal: Process design and simulation

    NARCIS (Netherlands)

    Chen, Wei; Ham, van der A.G.J.; Nijmeijer, A.; Winnubst, A.J.A.

    2015-01-01

    A membrane-integrated oxy-fuel combustion process is designed and simulated in UniSim Design®. The results of the simulation indicate that a net efficiency of 31.8% is obtained for a coal-fired power plant of 182 MWth (assuming only carbon in the coal), including the compression of CO2 to 100 bar. T

  15. Advanced aqueous reprocessing in P and T strategies: process demonstrations on genuine fuels and targets

    Energy Technology Data Exchange (ETDEWEB)

    Satmark, B.; Apostolidis, C.; Courson, O.; Malmbeck, R.; Carlos, R.; Pagliosa, G.; Romer, K.; Glatz, J.P. [European Commission, DG-JRC, Institute for Transuranium Elements, Hot Cell Technology, Karlsruhe (Germany)

    2000-07-01

    In the present work the performance of several processes used for advanced reprocessing of commercial LWR fuels as well as transmutation targets is compared. As a first step uranium and plutonium were recovered by PUREX type reprocessing. The raffinate, containing fission products, lanthanides and the minor actinides (MA) were used as feed for the second step in which minor actinides and lanthanides were separated from the bulk of the fission products. The five different processes tested use CMPO, DIDPA, TRPO, Diamide and CYANEX 923 as extractant. In the third step MA are separated from lanthanides. Here three processes were tested, i.e. using CYANEX 301, the synergistic mixture of di-chloro substituted CYANEX 301 and TOPO, and BTP solvents. Column-, batch- and continuous counter-current extraction techniques were used for the tests. The different processes will be described and discussed in terms of performances and efficiencies for Am and Cm. Efficient separation of MA from different genuine fuel solutions could be demonstrated and thereby also the possibility of closing a future transmutation fuel cycle. The combination, Diamide and BTP was found to be the best among extractants tested to achieve an efficient MA recovery from spent fuel. (authors)

  16. Determining the fate of virginiamycin in the fuel ethanol production process

    Science.gov (United States)

    Antibiotics are frequently used to prevent and treat bacterial contamination at commercial fuel ethanol facilities. A study to evaluate the fate of the antibiotic virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research...

  17. Advanced aqueous reprocessing in P and T strategies: process demonstrations on genuine fuels and targets

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, B.; Apostolidis, C.; Carlos, R.; Courson, O.; Glatz, J.P.; Malmbeck, R.; Pagliosa, G.; Roemer, K.; Serrano-Purroy, D. [European Commission, JRC, Inst. for Transuranium Elements, Karlsruhe (Germany)

    2004-07-01

    In the present work the performance of several processes used for advanced reprocessing of commercial LWR fuels as well as transmutation targets is compared. As a first step uranium and plutonium were recovered by PUREX type reprocessing. The raffinate, containing fission products including lanthanides and the minor actinides (MA) was used as feed for the second step in which minor actinides and lanthanides were separated from the bulk of the fission products. The five different processes tested use CMPO, DIDPA, TRPO, diamide and CYANEX 923 as extractants. In the third step MA are separated from lanthanides. Here three processes were tested, i.e. using CYANEX 301, the synergistic mixture of di-chloro substituted CYANEX 301 and TOPO, and BTP solvents. Column-, batch- and continuous counter-current extraction techniques were used for the tests. The different processes will be described and discussed in terms of performances and efficiencies for Am and Cm separation. Efficient separation of MA from different genuine fuel solutions could be demonstrated and thereby also the possibility of closing a future transmutation fuel cycle. The combination of diamide and BTP seems to be the best, among extractants tested, to achieve an efficient MA recovery from spent fuel. (orig.)

  18. TAPE CALENDERING MANUFACTURING PROCESS FOR MULTILAYER THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Kurt Montgomery

    2004-10-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the Phases I and II under Contract DE-AC26-00NT40705 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Tape Calendering Manufacturing Process For Multilayer Thin-Film Solid Oxide Fuel Cells''. The main objective of this project was to develop the manufacturing process based on tape calendering for multilayer solid oxide fuel cells (SOFC's) using the unitized cell design concept and to demonstrate cell performance under specified operating conditions. Summarized in this report is the development and improvements to multilayer SOFC cells and the unitized cell design. Improvements to the multilayer SOFC cell were made in electrochemical performance, in both the anode and cathode, with cells demonstrating power densities of nearly 0.9 W/cm{sup 2} for 650 C operation and other cell configurations showing greater than 1.0 W/cm{sup 2} at 75% fuel utilization and 800 C. The unitized cell design was matured through design, analysis and development testing to a point that cell operation at greater than 70% fuel utilization was demonstrated at 800 C. The manufacturing process for both the multilayer cell and unitized cell design were assessed and refined, process maps were developed, forming approaches explored, and nondestructive evaluation (NDE) techniques examined.

  19. High G Physiological Protection Training (Acceleratio;s Elevees: Protection par l’Entrainement)

    Science.gov (United States)

    1990-12-01

    1’origine d’un certain nombre de pertes, de connaissance (PC-G en- anglais G-Loc ou G induced Loss of Consciousness). Lorsque l’avion n’a Pu &re...25 et 26 avril 1985 (Compte-rendu de la conference de I’AGARD no 396). La question de l’entrainement h la protection anti-G y a 6t6 examinie. Au cours ...accept6 la creation de ce groupe de travail au cours de la 62ýme rdunion qui a eu lieu a Paris, France, les 26 et 27 mars 1987. Le groupe de travail no 14

  20. On the Parameterization of Convective Entrainment:Inherent Relationships among Entrainment Parameters in Bulk Models

    Institute of Scientific and Technical Information of China (English)

    SUN Jianning

    2009-01-01

    In this paper,the equilibrium entrainment into a shear-free,linearly stratified atmosphere is discussed under the framework of bulk models,namely,the zero-order jump model (ZOM) and the first-order jump model (FOM).The parameterizations for the dimensionless entrainment rate versus the convective Richardson number in the two models are compared.Based on the assumption that the parameterized entrainment rates in ZOM and FOM should be the same,the inherent relationships among the entrainment parameters in the bulk models are revealed.These relationships are supported by tank experiments and large-eddy simulations.The validity of these inherent relationships indicates that,for a convective boundary layer growing into a linearly stratified free atmosphere,the only dominant factors of the growth rate are the turbulent buoyancy in the mixed layer and the stratification in the free atmosphere.In the point of the similarity view,the former is characterized by turbulent temperature and mixing length scales (mixed layer depth),and the latter is characterized by the lapse rate of potential temperature in the free atmosphere.Thus,the commonly-used Richardson number scheme for the parameterization of the entrainment rate is just as an equivalent description.The variability of the total entrainment flux ratio in FOM,which is connected with the entrainment zone thickness,can implicitly describe the effect of the stratification in the free atmosphere,but the entrainment zone thickness is not an independent parameter.These results demonstrate the validity of the hypothesis that there exists a similarity limit in which the mixed layer depth is the only lengthscale.

  1. Effect of Colombian coal rank and its feeding technology on substitute natural gas production by entrained gasification

    Directory of Open Access Journals (Sweden)

    Juan Fernando Pérez-Bayer

    2016-01-01

    Full Text Available The effect of coal rank (from sub-bituminous to semi-anthracite and type of fuel feeding technology (slurry and dry on the production of substitute natural gas (SNG in entrained flow gasifiers is studied. Ten coals from important Colombian mines were selected. The process is modeled under thermochemical equilibrium using Aspen Plus, and its performance is evaluated in function of output parameters that include SNG heating value, Wobbe index, coal conversion efficiency, cold gas efficiency, process efficiency, global efficiency, and SNG production rate, among others. In descending order, the coal-to-SNG process improves energetically with the use of coals with: higher volatile-matter to fixed-carbon ratio, lower ash content, higher C+H/O ratio, and higher coal heating value. The overall energy efficiency of the slurry-feed technology (S-FT to produce SNG by gasification is 17% higher than the dry-feed technology (D-FT, possibly as a consequence of the higher CH4 concentration in the syngas (around 7 vol. % when the coal is fed as aqueous slurry. As the simulated SNG meets the natural gas (NG quality standards in Colombia, the substitute gaseous fuel could be directly transported through pipelines. Therefore, the coal-to-SNG process is a technically feasible and unconventional alternative for NG production.

  2. Non-catalytic alcoholysis process for production of biodiesel fuel by using bubble column reactor

    Science.gov (United States)

    Hagiwara, S.; Nabetani, H.; Nakajima, M.

    2015-04-01

    Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is usually defined as a fatty acid methyl ester (FAME) derived from vegetable oil or animal fat. In European countries, such as Germany and France, biodiesel fuel is commercially produced mainly from rapeseed oil, whereas in the United States and Argentina, soybean oil is more frequently used. In many other countries such as Japan and countries in Southeast Asia, lipids that cannot be used as a food source could be more suitable materials for the production of biodiesel fuel because its production from edible oils could result in an increase in the price of edible oils, thereby increasing the cost of some foodstuffs. Therefore, used edible oil, lipids contained in waste effluent from the oil milling process, byproducts from oil refining process and crude oils from industrial crops such as jatropha could be more promising materials in these countries. The materials available in Japan and Southeast Asia for the production of biodiesel fuel have common characteristics; they contain considerable amount of impurities and are high in free fatty acids (FFA). Superheated methanol vapor (SMV) reactor might be a promising method for biodiesel fuel production utilizing oil feedstock containing FFA such as waste vegetable oil and crude vegetable oil. In the conventional method using alkaline catalyst, FFA contained in waste vegetable oil is known to react with alkaline catalyst such as NaOH and KOH generating saponification products and to inactivate it. Therefore, the FFA needs to be removed from the feedstock prior to the reaction. Removal of the alkaline catalyst after the reaction is also required. In the case of the SMV reactor, the processes for removing FFA prior to the reaction and catalyst after the reaction can be omitted because it requires no catalyst. Nevertheless, detailed study on the productivity of biodiesel fuel produced from waste vegetable oils and other non

  3. Bond layer for a solid oxide fuel cell, and related processes and devices

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian; Striker, Todd-Michael; Renou, Stephane; Gaunt, Simon William

    2017-03-21

    An electrically-conductive layer of material having a composition comprising lanthanum and strontium is described. The material is characterized by a microstructure having bimodal porosity. Another concept in this disclosure relates to a solid oxide fuel cell attached to at least one cathode interconnect by a cathode bond layer. The bond layer includes a microstructure having bimodal porosity. A fuel cell stack which incorporates at least one of the cathode bond layers is also described herein, along with related processes for forming the cathode bond layer.

  4. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    Directory of Open Access Journals (Sweden)

    Slyusarskiy Konstantin V.

    2017-01-01

    Full Text Available Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The optimal fuel residence time and gasifyer specific productivity were defined. The prevail reactions in oxidizing and reduction zones together with its height were defined.

  5. Enhancement of photocatalytic activity of combustion-synthesized CeO2/C3N4 nanoparticles

    Science.gov (United States)

    Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing

    2015-09-01

    Nanocrystalline CeO2/C3N4 was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO2/C3N4 shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO2/C3N4 possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C3N4 and CeO2 in the photocatalytic process.

  6. EFFECTS OF ENTRAINED AIR MANNER ON CAVITATION DAMAGE*

    Institute of Scientific and Technical Information of China (English)

    WU Jian-hua; LUO Chao

    2011-01-01

    Early in 1953 the experiments by Peterka proved that air entrainment has effects on decreasing cavitation damage. This technology has been widely used in the release works of high dams since the inception of air entrainment in the Grand Goulee Dam in 1960. Behavior, mechanism and application of air entrainment for cavitation damage control have been investigated for over half century. However, severe cavitation damage happened due to complex mechanism of air entrainment. The effects of air entrainment are related to many factors, including geometric parameters, hydraulic parameters and entrained air manners. In the present work an experimental set-up for air entrainment was specially designed, the behavior of reducing cavitation damage was experimentally investigated in the three aspects of entrained air pressure, air tube aera and air tube number. The results show that magnitude of reduction of cavitation damage is closely related to the entrained air tube number as well as entrained air pressure, air tube aera, and that the effect through three air tubes is larger than that through single air tube although the entrained air tubes have the same sum of tube aera, that is, 1 + 1 + 1 > 3. Therefore, it is important to design an effective manner of air entrainment.

  7. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells; Estudo da reacao de reducao do oxigenio utilizando eletrocatalisadores a base de Pt-terras raras (La, Ce, Er) para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Thiago Bueno

    2013-07-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  8. Binder Jetting: A Novel Solid Oxide Fuel-Cell Fabrication Process and Evaluation

    Science.gov (United States)

    Manogharan, Guha; Kioko, Meshack; Linkous, Clovis

    2015-03-01

    With an ever-growing concern to find a more efficient and less polluting means of producing electricity, fuel cells have constantly been of great interest. Fuel cells electrochemically convert chemical energy directly into electricity and heat without resorting to combustion/mechanical cycling. This article studies the solid oxide fuel cell (SOFC), which is a high-temperature (100°C to 1000°C) ceramic cell made from all solid-state components and can operate under a wide range of fuel sources such as hydrogen, methanol, gasoline, diesel, and gasified coal. Traditionally, SOFCs are fabricated using processes such as tape casting, calendaring, extrusion, and warm pressing for substrate support, followed by screen printing, slurry coating, spray techniques, vapor deposition, and sputter techniques, which have limited control in substrate microstructure. In this article, the feasibility of engineering the porosity and configuration of an SOFC via an additive manufacturing (AM) method known as binder jet printing was explored. The anode, cathode and oxygen ion-conducting electrolyte layers were fabricated through AM sequentially as a complete fuel cell unit. The cell performance was measured in two modes: (I) as an electrolytic oxygen pump and (II) as a galvanic electricity generator using hydrogen gas as the fuel. An analysis on influence of porosity was performed through SEM studies and permeability testing. An additional study on fuel cell material composition was conducted to verify the effects of binder jetting through SEM-EDS. Electrical discharge of the AM fabricated SOFC and nonlinearity of permeability tests show that, with additional work, the porosity of the cell can be modified for optimal performance at operating flow and temperature conditions.

  9. Car plastic fuel tanks: closed loop recycling process, design and lifecycle assessment (RECAFUTA)

    Energy Technology Data Exchange (ETDEWEB)

    Yernaux, J-M. [SOLVAY SA, Research and Technology, Brussels (Belgium)

    2001-07-01

    A cooperative European Union-sponsored project to recycle high density plastic material from used automobile fuel tanks back into the original application is discussed. The goal of the project was to introduce 40 per cent of regenerate into new plastic fuel tanks. The project involved the development of design-for-recycling guidelines, development of a process for efficient recovery of the material by using super-critical carbon dioxide directly in the extruder, development of a process for upgrading the recycled material, and life cycle assessment to determine the reliability of the recycling process by comparing it to other alternatives such as landfilling or energy recovery. The project was recently completed and international validation tests are currently underway. The feasibility of upgrading the laboratory extrusion facility to industrial scale is in the process of being evaluated, concurrently with the development of an appropriate business plan. 7 figs.

  10. The effect of low-NOx combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    DEFF Research Database (Denmark)

    Pedersen, Kim Hougaard; Jensen, Anker Degn; Dam-Johansen, Kim

    2010-01-01

    been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NOx formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash...

  11. Processing Of Neem And Jatropha Methyl Esters –Alternative Fuels From Vegetable Oil

    Science.gov (United States)

    Ramasubramanian, S.; Manavalan, S.; Gnanavel, C.; Balakrishnan, G.

    2017-03-01

    Biodiesel is an alternative fuel for diesel engine. The methyl esters of vegetable oils, known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engine. This paper deals with the manufacturing process of Biodiesel from jatropha and neem oil. Biodiesel was prepared from neem oil and jatropha oil, the transestrified having kinematic viscosity of 3 & 2.6 centistokes, methanol ratio is 6:1 & 5.1respectively. The secondary solution is preheated at 65 C & 60 C and reaction temperature is maintained at 60C & 55 C and reaction time is 60 minutes approximately with NaOH catalyst and low viscosity oil is allowed to settle 24 hours. The average yield of neem and jatropha methyl esters was about 85%. These methyl esters shows excellent alternative under optimum condition for fossil fuels.

  12. Preliminary Study on the Fabrication of Particulate Fuel through Pressureless Sintering Process

    Directory of Open Access Journals (Sweden)

    Jong-Hwan Kim

    2016-01-01

    Full Text Available U-10wt%Zr spherical particles for use as particulate fuel were prepared by centrifugal atomization and subjected to pressureless sintering, which is one of the simplest powder processing techniques. At sintering temperature of 1100°C for 30 or 60 min, all samples ranging from +50 to −325 mesh showed no apparent bonding between the particles. However, at 1150°C (80 min, all samples formed a bulk body and the microstructures showed apparent sintering stages. Particularly, sample B (50–70 mesh and sample C (70–100 mesh showed pore characteristics suitable for a particulate fuel. The results suggest that pressureless sinterability for U-10Zr particulate fuel can be improved by adding small-size (–325 mesh particles.

  13. ACSEPT, a European project for a new step in the future demonstration of advanced fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, S. [CEA Marcoule 30 (France); Hill, C. [CEA Saclay, 91 - Gif sur Yvette (France); Caravaca, C.; Espartero, A. [Ciemat, Madrid (Spain); Rhodes, C.; Taylor, R.; Harrison, M. [National Nuclear Laboratory (United Kingdom); Geist, A. [Fachinformationszentrum Karlsruhe - INE (Germany); Modolo, G. [Forschungszentrum Juelich - FZJ (Germany); Cassayre, L. [Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (France); Malmbeck, R. [Joint Research Centre (JRC) - Institute for Transuranium Elements (ITU) (Germany); De Angelis, G. [ENEA, Bologna (Italy); Bouvet, S. [Alcan, 92 - Courbevoie (France); Klaassen, F. [Nuclear Research and consultancy Group (NRG) (Netherlands); Ekber, C.

    2010-11-15

    Partitioning and transmutation, associated to a multi-recycling of all transuranics should play a key role in the development of sustainable nuclear energy. By joining together 34 partners coming from European universities, nuclear research laboratories and major industrial players, in a multi-disciplinary consortium, the FP7-Euratom-Fission collaborative project ACSEPT (Actinide recycling by separation and transmutation), provides the sound basis and future improvements for future demonstrations of fuel treatment in strong connection with fuel fabrication techniques. ACSEPT is organized into 3 technical domains: 1) selecting and optimizing mature aqueous separation processes (Diamex-Sanex, Ganex); 2) high temperature pyrochemical separation processes, and 3) carrying out engineering and systems studies on hydro- and pyro-chemical processes to prepare for future demonstration at a pilot level. After 2 years of work, 2 successful hot-tests were performed in hydrometallurgy, validating the Sanex and i-Sanex routes. Efforts are now devoted to the Ganex concept. Progress was also made in fuel dissolution and fuel re-fabrication. In pyrometallurgy, promising routes are almost demonstrated for the actinide recovery from aluminium. (A.C.)

  14. Process Model of A Fusion Fuel Recovery System for a Direct Drive IFE Power Reactor

    Science.gov (United States)

    Natta, Saswathi; Aristova, Maria; Gentile, Charles

    2008-11-01

    A task has been initiated to develop a detailed representative model for the fuel recovery system (FRS) in the prospective direct drive inertial fusion energy (IFE) reactor. As part of the conceptual design phase of the project, a chemical process model is developed in order to observe the interaction of system components. This process model is developed using FEMLAB Multiphysics software with the corresponding chemical engineering module (CEM). Initially, the reactants, system structure, and processes are defined using known chemical species of the target chamber exhaust. Each step within the Fuel recovery system is modeled compartmentally and then merged to form the closed loop fuel recovery system. The output, which includes physical properties and chemical content of the products, is analyzed after each step of the system to determine the most efficient and productive system parameters. This will serve to attenuate possible bottlenecks in the system. This modeling evaluation is instrumental in optimizing and closing the fusion fuel cycle in a direct drive IFE power reactor. The results of the modeling are presented in this paper.

  15. Study on the high-precision laser welding technology of nuclear fuel elements processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Sung; Yang, M. S.; Kim, W. K.; Lee, D. Y

    2001-01-01

    The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry.

  16. Spent nuclear fuel. A review of properties of possible relevance to corrosion processes

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R. [Caledon Consult AB, Nykoeping (Sweden)

    1995-04-01

    The report reviews the properties of spent fuel which are considered to be of most importance in determining the corrosion behaviour in groundwaters. Pellet cracking and fragment size distribution are discussed, together with the available results of specific surface area measurements on spent fuel. With respect to the importance of fuel microstructure, emphasis is placed on recent work on the so called structural rim effect, which consists of the formation of a zone of high porosity, and the polygonization of fuel grains to form many sub-grains, at the pellet rim, and appears to be initiated when the average pellet burnup exceeds a threshold of about 40 MWd/kgU. Due to neutron spectrum effects, the pellet rim is also associated with the buildup of plutonium and other actinides, which results in an enhanced local burnup and specific activity of both beta-gamma and alpha radiation, thus representing a greater potential for radiolysis effects in ingressed groundwater. The report presents and discusses the results of quantitative determination of the radial profiles of burnup and alpha activity on spent fuel with average burnups from 21.2 to 49 MWd/kgU. In addition to the radial variation of fission product and actinide inventories due to the effects mentioned above, migration, redistribution and release of some fission products can occur during reactor irradiation and the report concludes with a short review of these processes.

  17. Electrical and physical properties of composite BaZr0.85Y0.15O3-d-Nd0.1Ce0.9O2-δ electrolytes for intermediate temperature-solid oxide fuel cells

    Science.gov (United States)

    Park, Ka-Young; Lee, Tae-Hee; Jo, Suyeon; Yang, Jayoon; Song, Sun-Ju; Lim, Hyung-Tae; Kim, Jung Hyun; Park, Jun-Young

    2016-12-01

    Co-ionic (H+/O2-) electrolytes are fabricated by compositing both proton conductor (BaZr0.85Y0.15O3-δ, BZY) and oxygen-ion conductor (Nd0.1Ce0.9O2-δ, NDC) for intermediate temperature-solid oxide fuel cells (IT-SOFCs). This hybrid electrolyte decreases the electronic loss of NDC under reducing atmospheres and improves the poor sinterability of BZY. The electronic conduction caused by the NDC reduction is effectively blocked by the BZY in the composite electrolyte, thus offering both advantages of BZY with its high OCV and more rigid electro-chemo-mechanical property. In addition, the composite BZY-NDC electrolyte also exhibits great chemical stability against exposure to steam and CO2. Furthermore, the compositing of BZY and NDC improves the proton conductivity of the electrolytes, and the conductivity of composite electrolyte is higher than that of single BZY at temperatures >600 °C.

  18. Pyrolysis and Combustion of Pulverized Wheat Straw in a Pressurized Entrained Flow Reactor

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Gjernes, Erik; Hansen, Lars Kresten

    1996-01-01

    Within the past decade, there has been an interest for pressurized combustion and gasification of solid fuels in power plants due to the potential for high efficiency. The utilization of new types of solid fuels for pressurized combustion and gasification depends on char yield and char reactivity...... at relevant conditions. The pressurized entrained now reactor designed at Rise is introduced. Pyrolysis and combustion at 10 and 20 bar pressure have been studied using pulverized wheat straw. Samples of partly reacted particles are collected, and the conversion is calculated using the ash tracer technique...

  19. System and process for producing fuel with a methane thermochemical cycle

    Energy Technology Data Exchange (ETDEWEB)

    Diver, Richard B.

    2015-12-15

    A thermochemical process and system for producing fuel are provided. The thermochemical process includes reducing an oxygenated-hydrocarbon to form an alkane and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. Another thermochemical process includes reducing a metal oxide to form a reduced metal oxide, reducing an oxygenated-hydrocarbon with the reduced metal oxide to form an alkane, and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. The system includes a reformer configured to perform a thermochemical process.

  20. Fuel ethanol production from lignocellulose: a challenge for metabolic engineering and process integration

    DEFF Research Database (Denmark)

    Zaldivar, Jesus; Nielsen, Jens; Olsson, Lisbeth

    2001-01-01

    and with the implementation of environmental protection laws in many countries, demand for this fuel is increasing. Efficient ethanol production processes and cheap substrates are needed. Current ethanol production processes using crops such as sugar cane and corn are well-established; however, utilization of a cheaper...... substrate such as lignocellulose could make bioethanol more competitive with fossil fuel. The processing and utilization of this substrate is complex, differing, in many aspects from crop-based ethanol production. One important requirement is an efficient microorganism able to ferment a variety of sugars...... (pentoses, and hexoses) as well as to tolerate stress conditions. Through metabolic engineering, bacterial and yeast strains have been constructed which feature traits that are advantageous for ethanol production using lignocellulose sugars. After several rounds of modification...

  1. Numerical simulations of transient air entrainment by rough and smooth plunging jets

    Science.gov (United States)

    Kiger, Ken; Kharoua, Nabil; Khezzar, Lyes

    2012-11-01

    Plunging jets are intimately linked to the process of air or gas entrainment into liquid pools, and can play either a beneficial or detrimental role in many environmental and industrial flows. The purpose of the present work is to assess the capability of combined LES/VOF algorithms to simulate water/air plunging jet flows, starting with the transient impact of the free jet, initial cavity formation, pinch off, and evolution towards a continuous entrainment phase. We focus on what happens in the transient impact phase for weakly and highly disturbed jets, operating with impact conditions of Re = UD / ν = 10 , 500 , We = ρU2 D / σ = 300 and Fr =U2 / gD = 83 . In particular, the study investigates the ability of the simulations to capture liquid surface instabilities and the influence of the exiting jet turbulence content on the entrainment behavior. The results indicate that the qualitative behavior of the entrainment process follows very closely what is observed in experiments, with the rough jet exhibiting surface instabilities at impact that are not present in the smooth jet. These have an effect on the development of the initial air cavity and interfacial area, leading to a doubling of the interfacial area for a nominally similar entrained volume of air.

  2. Management of Salt Waste from Electrochemical Processing of Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Michael F. Simpson; Michael N. Patterson; Joon Lee; Yifeng Wang; Joshua Versey; Ammon Williams; Supathorn Phongikaroon; James Allensworth; Man-Sung Yim

    2013-10-01

    Electrochemical processing of used nuclear fuel involves operation of one or more cells containing molten salt electrolyte. Processing of the fuel results in contamination of the salt via accumulation of fission products and transuranic (TRU) actinides. Upon reaching contamination limits, the salt must be removed and either disposed or treated to remove the contaminants and recycled back to the process. During development of the Experimental Breeder Reactor-II spent fuel treatment process, waste salt from the electrorefiner was to be stabilized in a ceramic waste form and disposed of in a high-level waste repository. With the cancellation of the Yucca Mountain high-level waste repository, other options are now being considered. One approach that involves direct disposal of the salt in a geologic salt formation has been evaluated. While waste forms such as the ceramic provide near-term resistance to corrosion, they may not be necessary to ensure adequate performance of the repository. To improve the feasibility of direct disposal, recycling a substantial fraction of the useful salt back to the process equipment could minimize the volume of the waste. Experiments have been run in which a cold finger is used for this purpose to crystallize LiCl from LiCl/CsCl. If it is found to be unsuitable for transportation, the salt waste could also be immobilized in zeolite without conversion to the ceramic waste form.

  3. AW-101 entrained solids - Solubility versus temperature

    Energy Technology Data Exchange (ETDEWEB)

    GJ Lumetta; RC Lettau; GF Piepel

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AW-101 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AW-1-1 sample using de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AW-101 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions. The work was conducted according to test plan BNFL-TP-29953-7, Rev. 0, Determination of the Solubility of LAW Entrained Solids. The test went according to plan, with no deviations from the test plan.

  4. Novel Catalysts and Processing Technologies for Production of Aerospace Fuels from Non-Petroleum Raw Materials

    Science.gov (United States)

    Hepp, Aloysius F.; Kulis, Michael J.; Psarras, Peter C.; Ball, David W.; Timko, Michael T.; Wong, Hsi-Wu; Peck, Jay; Chianelli, Russell R.

    2014-01-01

    Transportation fuels production (including aerospace propellants) from non-traditional sources (gases, waste materials, and biomass) has been an active area of research and development for decades. Reducing terrestrial waste streams simultaneous with energy conversion, plentiful biomass, new low-cost methane sources, and/or extra-terrestrial resource harvesting and utilization present significant technological and business opportunities being realized by a new generation of visionary entrepreneurs. We examine several new approaches to catalyst fabrication and new processing technologies to enable utilization of these nontraditional raw materials. Two basic processing architectures are considered: a single-stage pyrolysis approach that seeks to basically re-cycle hydrocarbons with minimal net chemistry or a two-step paradigm that involves production of supply or synthesis gas (mainly carbon oxides and H2) followed by production of fuel(s) via Sabatier or methanation reactions and/or Fischer-Tröpsch synthesis. Optimizing the fraction of product stream relevant to targeted aerospace (and other transportation) fuels via modeling, catalyst fabrication and novel reactor design are described. Energy utilization is a concern for production of fuels for either terrestrial or space operations; renewable sources based on solar energy and/or energy efficient processes may be mission enabling. Another important issue is minimizing impurities in the product stream(s), especially those potentially posing risks to personnel or operations through (catalyst) poisoning or (equipment) damage. Technologies being developed to remove (and/or recycle) heteroatom impurities are briefly discussed as well as the development of chemically robust catalysts whose activities are not diminished during operation. The potential impacts on future missions by such new approaches as well as balance of system issues are addressed.

  5. MINING PROCESS AND PRODUCT INFORMATION FROM PRESSURE FLUCTUATIONS WITHIN A FUEL PARTICLE COATER

    Energy Technology Data Exchange (ETDEWEB)

    Douglas W. Marshall; Charles M. Barnes

    2008-09-01

    The Next Generation Nuclear Power (NGNP) Fuel Development and Qualification Program included the design, installation, and testing of a 6-inch diameter nuclear fuel particle coater to demonstrate quality TRISO fuel production on a small industrial scale. Scale-up from the laboratory-scale coater faced challenges associated with an increase in the kernel charge mass, kernel diameter, and a redesign of the gas distributor to achieve adequate fluidization throughout the deposition of the four TRISO coating layers. TRISO coatings are applied at very high temperatures in atmospheres of dense particulate clouds, corrosive gases, and hydrogen concentrations over 45% by volume. The severe environment, stringent product and process requirements, and the fragility of partially-formed coatings limit the insertion of probes or instruments into the coater vessel during operation. Pressure instrumentation were installed on the gas inlet line and exhaust line of the 6-inch coater to monitor the bed differential pressure and internal pressure fluctuations emanating from the fuel bed as a result of bed and gas “bubble” movement. These instruments are external to the particle bed and provide a glimpse into the dynamics of fuel particle bed during the coating process and data that could be used to help ascertain the adequacy of fluidization and, potentially, the dominant fluidization regimes. Pressure fluctuation and differential pressure data are not presently useful as process control instruments, but data suggest a link between the pressure signal structure and some measurable product attributes that could be exploited to get an early estimate of the attribute values.

  6. Novel Catalysts and Processing Technologies for Production of Aerospace Fuels from Non-Petroleum Raw Materials

    Science.gov (United States)

    Hepp, A. F.; Kulis, M. J.; Psarras, P. C.; Ball, D. W.; Timko, M. T.; Wong, H.-W.; Peck, J.; Chianelli, R. R.

    2014-01-01

    Transportation fuels production (including aerospace propellants) from non-traditional sources (gases, waste materials, and biomass) has been an active area of research and development for decades. Reducing terrestrial waste streams simultaneous with energy conversion, plentiful biomass, new low-cost methane sources, and/or extra-terrestrial resource harvesting and utilization present significant technological and business opportunities being realized by a new generation of visionary entrepreneurs. We examine several new approaches to catalyst fabrication and new processing technologies to enable utilization of these non-traditional raw materials. Two basic processing architectures are considered: a single-stage pyrolysis approach that seeks to basically re-cycle hydrocarbons with minimal net chemistry or a two-step paradigm that involves production of supply or synthesis gas (mainly carbon oxides and hydrogen) followed by production of fuel(s) via Sabatier or methanation reactions and/or Fischer-Tropsch synthesis. Optimizing the fraction of product stream relevant to targeted aerospace (and other transportation) fuels via modeling, catalyst fabrication and novel reactor design are described. Energy utilization is a concern for production of fuels for either terrestrial or space operations; renewable sources based on solar energy and/or energy efficient processes may be mission enabling. Another important issue is minimizing impurities in the product stream(s), especially those potentially posing risks to personnel or operations through (catalyst) poisoning or (equipment) damage. Technologies being developed to remove (and/or recycle) heteroatom impurities are briefly discussed as well as the development of chemically robust catalysts whose activity are not diminished during operation. The potential impacts on future missions by such new approaches as well as balance of system issues are addressed.

  7. Alignment strategies for the entrainment of music and movement rhythms.

    Science.gov (United States)

    Moens, Bart; Leman, Marc

    2015-03-01

    Theories of entrainment assume that spontaneous entrainment emerges from dynamic laws that operate via mediators on interactions, whereby entrainment is facilitated if certain conditions are fulfilled. In this study, we show that mediators can be built that affect the entrainment of human locomotion to music. More specifically, we built D-Jogger, a music player that functions as a mediator between music and locomotion rhythms. The D-Jogger makes it possible to manipulate the timing differences between salient moments of the rhythms (beats and footfalls) through the manipulation of the musical period and phase, which affect the condition in which entrainment functions. We conducted several experiments to explore different strategies for manipulating the entrainment of locomotion and music. The results of these experiments showed that spontaneous entrainment can be manipulated, thereby suggesting different strategies on how to embark. The findings furthermore suggest a distinction among different modalities of entrainment: finding the beat (the most difficult part of entrainment), keeping the beat (easier, as a temporal scheme has been established), and being in phase (no entrainment is needed because the music is always adapted to the human rhythm). This study points to a new avenue of research on entrainment and opens new perspectives for the neuroscience of music.

  8. Rod Driven Frequency Entrainment and Resonance Phenomena

    Directory of Open Access Journals (Sweden)

    Christina Salchow

    2016-08-01

    Full Text Available A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α of each volunteer in the range from 0.40–2.30*α. 306-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10*α and half of the alpha frequency (0.40–0.55*α. No signs of resonance and frequency entrainment phenomena were revealed around 2.00*α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30*α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex.

  9. Rod Driven Frequency Entrainment and Resonance Phenomena

    Science.gov (United States)

    Salchow, Christina; Strohmeier, Daniel; Klee, Sascha; Jannek, Dunja; Schiecke, Karin; Witte, Herbert; Nehorai, Arye; Haueisen, Jens

    2016-01-01

    A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30∗α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10∗α) and half of the alpha frequency (0.40–0.55∗α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00∗α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30∗α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex. PMID:27588002

  10. Proceedings of a workshop on the utilization of coal fuels in process heaters

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Almost 5% of the nation's energy consumption takes place in tubular process heaters. Currently, these units are gas- and, to a lesser extent, oil-fired. Process heaters provide energy for refining petroleum and the manufacture of numerous chemicals and petrochemicals. Since the current state-of-the-art, using waste heat recovery and forced draft burners, can achieve thermal efficiencies of about 90%, it is unlikely that current process heat and fuel requirements will be dramatically reduced by process modifications and/or conservation measures. Hence, if this sizeable, inexorable drain on our fluid petroleum reserves is to be halted, it seems reasonable to consider the utilization of coal and/or coal-based fuels to fire process heaters. In order to assess the feasibility and potential for a coal-based process heater industry, Brookhaven National Laboratory (BNL) organized a workshop to define and explore the various problems that must be solved in order to burn coal in process heaters. A primary aim of the workshop was to consider the design methodology for process heaters when firing coal and compare it to those for gas and oil firing. The overall conclusions were: that retrofitting present process heaters to coal fuel was impractical; that it would be difficult to fit larger heaters designed to burn coal into present refineries; that there would be difficulties with process heaters burning coal; and that a better approach would be one large utility coal heater with a circulating heat transfer medium. Seven papers have been entered individually into EDB and ERA. (LTN)

  11. Cyclic voltammetry study of Ce(IV/Ce(III redox couple and Ce(IV-F complex in sulfuric acid medium

    Directory of Open Access Journals (Sweden)

    J. G. He

    2016-10-01

    Full Text Available In this paper the electrochemical behaviors of Ce(IV/Ce(III redox couple and Ce(IV - F complex in sulfuric acid medium were studied by cyclic voltammetry using a platinum electrode. Both of the Ce(IV/Ce(III couple in Ce(IV solution and Ce(IV - F complex is a quasi-reversible process, and gives a linear correlation between the peak potentials and square root of scan rates, showing that the kinetics of the overall process is diffusion controlled. The complexation of cerium(IV and fluoride is favorable for the oxidation of Ce(III. The kinetic parameters such as diffusion coefficients, anodic transfer coefficients and rate constants were studied.

  12. Diurnally entrained anticipatory behavior in archaea.

    Directory of Open Access Journals (Sweden)

    Kenia Whitehead

    Full Text Available By sensing changes in one or few environmental factors biological systems can anticipate future changes in multiple factors over a wide range of time scales (daily to seasonal. This anticipatory behavior is important to the fitness of diverse species, and in context of the diurnal cycle it is overall typical of eukaryotes and some photoautotrophic bacteria but is yet to be observed in archaea. Here, we report the first observation of light-dark (LD-entrained diurnal oscillatory transcription in up to 12% of all genes of a halophilic archaeon Halobacterium salinarum NRC-1. Significantly, the diurnally entrained transcription was observed under constant darkness after removal of the LD stimulus (free-running rhythms. The memory of diurnal entrainment was also associated with the synchronization of oxic and anoxic physiologies to the LD cycle. Our results suggest that under nutrient limited conditions halophilic archaea take advantage of the causal influence of sunlight (via temperature on O(2 diffusivity in a closed hypersaline environment to streamline their physiology and operate oxically during nighttime and anoxically during daytime.

  13. First determination of s-process element abundances in pre-main sequence clusters. Y, Zr, La, and Ce in IC 2391, the Argus association, and IC 2602

    Science.gov (United States)

    D'Orazi, V.; De Silva, G. M.; Melo, C. F. H.

    2017-02-01

    Context. Several high-resolution spectroscopic studies have provided compelling observational evidence that open clusters display a decreasing trend of their barium abundances as a function of the cluster's age. Young clusters (ages ≲ 200 Myr) exhibit significant enhancement in the [Ba/Fe] ratios, at variance with solar-age clusters where the Ba content has been found to be [Ba/Fe] 0 dex. Different viable solutions have been suggested in the literature; nevertheless, a conclusive interpretation of such a peculiar trend has not been found. Interestingly, it is debated whether the other species produced with Ba via s-process reactions follow the same trend with age. Aims: Pre-main sequence clusters (≈10-50 Myr) show the most extreme behaviour in this respect: their [Ba/Fe] ratios can reach 0.65 dex, which is higher than the solar value by a factor of four. Crucially, there are no investigations of the other s-process species for these young stellar populations. In this paper we present the first determination of Y, Zr, La, and Ce in clusters IC 2391, IC 2602, and the Argus association. The main objective of our work is to ascertain whether these elements reveal the same enhancement as Ba. Methods: We have exploited high-resolution, high signal-to-noise spectra in order to derive abundances for Y, Zr, La, and Ce via spectral synthesis calculations. Our sample includes only stars with very similar atmospheric parameters so that internal errors due to star-to-star inhomogeneity are negligible. The chemical analysis was carried out in a strictly differential way, as done in all our previous investigations, to minimise the impact of systematic uncertainties. Results: Our results indicate that, at variance with Ba, all the other s-process species exhibit a solar scaled pattern; these clusters confirm a similar trend discovered in the slightly older local associations (e.g. AB Doradus, Carina-Near), where only Ba exhibit enhanced value with all other s-process species

  14. New insights into the wind-dust relationship in sandblasting and direct aerodynamic entrainment from wind tunnel experiments

    KAUST Repository

    Parajuli, Sagar Prasad

    2016-01-22

    Numerous parameterizations have been developed for predicting wind erosion, yet the physical mechanism of dust emission is not fully understood. Sandblasting is thought to be the primary mechanism, but recent studies suggest that dust emission by direct aerodynamic entrainment can be significant under certain conditions. In this work, using wind tunnel experiments, we investigated some of the lesser understood aspects of dust emission in sandblasting and aerodynamic entrainment for three soil types, namely clay, silty clay loam, and clay loam. First, we explored the role of erodible surface roughness on dust emitted by aerodynamic entrainment. Second, we compared the emitted dust concentration in sandblasting and aerodynamic entrainment under a range of wind friction velocities. Finally, we explored the sensitivity of emitted dust particle size distribution (PSD) to soil type and wind friction velocity in these two processes. The dust concentration in aerodynamic entrainment showed strong positive correlation, no significant correlation, and weak negative correlation, for the clay, silty clay loam, and clay loam, respectively, with the erodible soil surface roughness. The dust in aerodynamic entrainment was significant constituting up to 28.3, 41.4, and 146.4% compared to sandblasting for the clay, silty clay loam, and clay loam, respectively. PSD of emitted dust was sensitive to soil type in both sandblasting and aerodynamic entrainment. PSD was sensitive to the friction velocity in aerodynamic entrainment but not in sandblasting. Our results highlight the need to consider the details of sandblasting and direct aerodynamic entrainment processes in parameterizing dust emission in global/regional climate models.

  15. On Chinglish in C-E Interpretation

    Institute of Scientific and Technical Information of China (English)

    XIAO Gui-fang; LIU Jian-zhu; GUI Ren-na

    2005-01-01

    Based on the author's survey into the different interpretations of some terms from Chinese into English, the paper points out Chinglish exists universally in C-E interpretation.The author also puts forward some proposals on how to avoid and reduce Chinglish in the process of C-E interpretation after exploring its features and causes of Chinglish.

  16. Uncertainty associated with convective wet removal of entrained aerosols in a global climate model

    Science.gov (United States)

    Croft, B.; Pierce, J. R.; Martin, R. V.; Hoose, C.; Lohmann, U.

    2012-11-01

    The uncertainties associated with the wet removal of aerosols entrained above convective cloud bases are investigated in a global aerosol-climate model (ECHAM5-HAM) under a set of limiting assumptions for the wet removal of the entrained aerosols. The limiting assumptions for the wet removal of entrained aerosols are negligible scavenging and vigorous scavenging (either through activation, with size-dependent impaction scavenging, or with the prescribed fractions of the standard model). To facilitate this process-based study, an explicit representation of cloud-droplet-borne and ice-crystal-borne aerosol mass and number, for the purpose of wet removal, is introduced into the ECHAM5-HAM model. This replaces and is compared with the prescribed cloud-droplet-borne and ice-crystal-borne aerosol fraction scavenging scheme of the standard model. A 20% to 35% uncertainty in simulated global, annual mean aerosol mass burdens and optical depth (AOD) is attributed to different assumptions for the wet removal of aerosols entrained above convective cloud bases. Assumptions about the removal of aerosols entrained above convective cloud bases control modeled upper tropospheric aerosol concentrations by as much as one order of magnitude. Simulated aerosols entrained above convective cloud bases contribute 20% to 50% of modeled global, annual mean aerosol mass convective wet deposition (about 5% to 10% of the total dry and wet deposition), depending on the aerosol species, when including wet scavenging of those entrained aerosols (either by activation, size-dependent impaction, or with the prescribed fraction scheme). Among the simulations, the prescribed fraction and size-dependent impaction schemes yield the largest global, annual mean aerosol mass convective wet deposition (by about two-fold). However, the prescribed fraction scheme has more vigorous convective mixed-phase wet removal (by two to five-fold relative to the size-dependent impaction scheme) since nearly all

  17. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream.

  18. Designing and optimization of a micro CHP system based on Solid Oxide Fuel Cell with different fuel processing technologies

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    (SMR) and partial oxidation (CPO) will be investigated for each configuration. The internal reforming will be also considered for its ability to reduce the stack temperature and decrease the need of cooling air. Finally, optimization criteria for SOFC systems applied to single-family detached dwellings...... are the possibility to partially reform hydrocarbon in the fuel cell anode compartment and the possibility to use high quality heat for cogeneration. In this work, different configurations of solid oxide fuel cell system for decentralized electricity production are examined. The Balance of Plant (BoP) components...... of the Micro Combined Heat and Power plant (mCHP) will be identified including fuel and air supply, fuel management anode re-circulation, exhaust gas heat management, power conditioning and control system. Using mass and energy balance, different types of fuel reforming including steam reforming...

  19. Getting the beat: entrainment of brain activity by musical rhythm and pleasantness.

    Science.gov (United States)

    Trost, Wiebke; Frühholz, Sascha; Schön, Daniele; Labbé, Carolina; Pichon, Swann; Grandjean, Didier; Vuilleumier, Patrik

    2014-12-01

    Rhythmic entrainment is an important component of emotion induction by music, but brain circuits recruited during spontaneous entrainment of attention by music and the influence of the subjective emotional feelings evoked by music remain still largely unresolved. In this study we used fMRI to test whether the metric structure of music entrains brain activity and how music pleasantness influences such entrainment. Participants listened to piano music while performing a speeded visuomotor detection task in which targets appeared time-locked to either strong or weak beats. Each musical piece was presented in both a consonant/pleasant and dissonant/unpleasant version. Consonant music facilitated target detection and targets presented synchronously with strong beats were detected faster. FMRI showed increased activation of bilateral caudate nucleus when responding on strong beats, whereas consonance enhanced activity in attentional networks. Meter and consonance selectively interacted in the caudate nucleus, with greater meter effects during dissonant than consonant music. These results reveal that the basal ganglia, involved both in emotion and rhythm processing, critically contribute to rhythmic entrainment of subcortical brain circuits by music.

  20. Word-by-word entrainment of speech rhythm during joint story building

    Directory of Open Access Journals (Sweden)

    Tommi eHimberg

    2015-06-01

    Full Text Available Movements and behaviour synchronise during social interaction at many levels, often unintentionally. During smooth conversation, for example, participants adapt to each others' speech rates. Here we aimed to find out to which extent speakers adapt their turn-taking rhythms during a story-building game.Nine sex-matched dyads of adults (12 males, 6 females created two 5-min stories by contributing to them alternatingly one word at a time. The participants were located in different rooms, with audio connection during one story and audiovisual during the other. They were free to select the topic of the story.Although the participants received no instructions regarding the timing of the story building, their word rhythms were highly entrained (R ̅ = 0.70, p < 0.001 even though the rhythms as such were unstable (R ̅ = 0.14 for pooled data. Such high entrainment in the absence of steady word rhythm occurred in every individual story, independently of whether the subjects were connected via audio-only or audiovisual link.The observed entrainment was of similar strength as typical entrainment in finger-tapping tasks where participants are specifically instructed to synchronize their behaviour. Thus speech seems to spontaneously induce strong entrainment between the conversation partners, likely reflecting automatic alignment of their semantic and syntactic processes.

  1. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    OpenAIRE

    Slyusarskiy Konstantin V.; Korotkikh Alexander G.; Sorokin Ivan V.

    2017-01-01

    Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The o...

  2. Design and verification of shielding for the advanced spent fuel conditioning process facility.

    Science.gov (United States)

    Cho, I J; Kook, D H; Kwon, K C; Lee, E P; Choung, W M; You, G S

    2008-05-01

    An Advanced spent fuel Conditioning Process Facility (ACPF) has recently been constructed by a modification of previously unused cells. ACPF is a hot cell with two rooms located in the basement of the Irradiated Materials Experiment Facility (IMEF) at the Korea Atomic Energy Research Institute. This is for demonstrating the advanced spent fuel conditioning process being proposed in Korea, which is an electrolytic reduction process of spent oxide fuels into a metallic form. The ACPF was designed with a more than 90 cm thick high density concrete shield wall to handle 1.38 PBq (37,430 Ci) of radioactive materials with dose rates lower than 10 muSv h in the operational areas (7,000 zone) and 150 muSv h in the service areas (8,000 zone). In Monte Carlo calculations with a design basis source inventory, the results for the bounding wall showed a maximum of 3 muSv h dose rate at an exterior surface of the ACPF for gamma radiation and 0.76 muSv h for neutrons. All the bounding structures of the ACPF were investigated to check on the shielding performance of the facility to ensure the radiation safety of the facility. A test was performed with a 2.96 TBq (80 Ci) 60Co source unit and the test results were compared with the calculation results. A few failure points were discovered and carefully fixed to meet the design criteria. After fixing the problems, the failure points were rechecked and the safety of the shielding structures was confirmed. In conclusion, it was confirmed that all the investigated parts of the ACPF passed the shielding safety limits by using this program and the ACPF is ready to fulfill its tasks for the advanced spent fuel conditioning process.

  3. Effects of Fuel Temperature on Injection Process and Combustion of Dimethyl Ether Engine.

    Science.gov (United States)

    Guangxin, Gao; Zhulin, Yuan; Apeng, Zhou; Shenghua, Liu; Yanju, Wei

    2013-12-01

    To investigate the effects of fuel temperature on the injection process in the fuel-injection pipe and the combustion characteristics of compression ignition (CI) engine, tests on a four stroke, direct injection dimethyl ether (DME) engine were conducted. Experimental results show that as the fuel temperature increases from 20 to 40 °C, the sound speed is decreased by 12.2%, the peak line pressure at pump and nozzle sides are decreased by 7.2% and 5.6%, respectively. Meanwhile, the injection timing is retarded by 2.2 °CA and the injection duration is extended by 0.8 °CA. Accordingly, the ignition delay and the combustion duration are extended by 0.7 °CA and 4.0 °CA, respectively. The cylinder peak pressure is decreased by 5.4%. As a result, the effective thermal efficiency is decreased, especially for temperature above 40 °C. Before beginning an experiment, the fuel properties of DME, including the density, the bulk modulus, and the sound speed were calculated by "ThermoData." The calculated result of sound speed is consistent with the experimental results.

  4. Surface energy equation for heat transfer process in a pebble fuel

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa-Paredes, G., E-mail: gepe@xanum.uam.mx [Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186 Col. Vicentina, México, DF 09340 (Mexico); Castillo-Jiménez, V. [Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186 Col. Vicentina, México, DF 09340 (Mexico); Herranz-Puebla, L.E. [División de Fisión Nuclear, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Avda. Complutense, 22, 28040 Madrid (Spain); Vázquez-Rodríguez, R. [Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186 Col. Vicentina, México, DF 09340 (Mexico)

    2014-12-15

    Highlights: • Steady and transient behaviors of the interfacial heat transfer in a fuel element. • Non-local averaging volume method for deriving the surface energy equation. • The method captures significant physical phenomena of the interfacial heat transfer. • Closure relationships are proposed in order to obtain the temperatures distribution. • The derived average equation represents an upscaling regarding the local description. - Abstract: In this paper the surface energy equation for the heat transfer process (HT) between the mixture of fuel (TRISO particles and graphite matrix) and coating in a fuel pebble is derived. The fuel pebble can be treated as a heterogeneous region (mixture of microspheres and graphite) interacting thermally with the homogeneous region (the coating or cladding). These two regions are separated by a boundary region where the properties and behavior differ from those of the adjoining regions. The methodology applied for deriving the surface energy equation is based on the classical theory on interfacial transport phenomena. The surface energy equation derived in this work is an average equation that represents an upscaling respect to the local description. The regions around the surface where changes in the physical phenomena are important are of the order of microns, in contrast with interfacial mass transfer between phases that may be several molecular diameters. The numerical analysis regarding the application of surface energy equation is presented in this work.

  5. BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3-{delta}} electrolyte-based solid oxide fuel cells with cobalt-free PrBaFe{sub 2}O{sub 5+{delta}} layered perovskite cathode

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Hanping; Xue, Xingjian [Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2010-10-15

    A new anode-supported SOFC material system Ni-BZCYYb vertical stroke BZCYYb vertical stroke PBFO is investigated, in which a cobalt-free layered perovskite oxide, PrBaFe{sub 2}O{sub 5+{delta}} (PBFO), is synthesized and employed as a novel cathode while the synthesized BZCYYb is used as an electrolyte. The cell is fabricated by a simple dry-pressing/co-sintering process. The cell is tested and characterized under intermediate temperature range from 600 to 700 C with humified H{sub 2} ({proportional_to}3% H{sub 2}O) as fuel, ambient air as oxidant. The results show that the open-circuit potential of 1.006 V and maximal power density of 452 mW cm{sup -2} are achieved at 700 C. The polarization resistance of the electrodes is 0.18 {omega} cm{sup 2} at 700 C. Compared to BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}O{sub 3-{delta}}, the conductivity of co-doped barium zirconate-cerate BZCYYb is significantly improved. The ohmic resistance of single cell is 0.37 {omega} cm{sup 2} at 700 C. The results indicate that the developed Ni-BZCYYb vertical stroke BZCYYb vertical stroke PBFO cell is a promising functional material system for SOFCs. (author)

  6. Liquid plasma sprayed nano-network La0.4Sr0.6Co0.2Fe0.8O3/Ce0.8Gd0.2O2 composite as a high-performance cathode for intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Zhang, Shan-Lin; Li, Chang-Jiu; Li, Cheng-Xin; Yang, Guan-Jun; Huang, Kevin; Liu, Meilin

    2016-09-01

    Here, we investigate the feasibility of using a liquid plasma spray process as a novel method for the cost-effective fabrication of a nanonetwork of La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF) and Ce0.8Gd0.2O2-δ (GDC) composite as a high-performance cathode for intermediate-temperature solid oxide fuel cells. A suspension containing well-dispersed nanosized GDC particles in an LSCF precursor solution is designed as the feedstock. The effects of GDC concentration in the suspension on the phase composition, microstructure, and electrochemical performance of the resulting cathode are studied. When the GDC concentration increases to 15 g L-1, the nanosized GDC particles distribute uniformly and continuously on the LSCF backbone to form a porous network structure. The electrochemical studies further indicate that the cathode polarization decreased with the increase in GDC concentration from 0 g L-1 to 15 g L-1, whereas a further increase in the GDC concentration increases the cathode polarization instead. At 600 and 750 °C, the cathode prepared using 15 g L-1 GDC concentration exhibits an impressive area-specific polarization resistance (Rp) of 0.1 Ω cm2 and 0.009 Ω cm2, respectively. Finally, the Rp of the optimal cathode almost does not change after the isothermal dwelling at 650 °C for 350 h.

  7. Gas and liquid phase fuels desulphurization for hydrogen production via reforming processes

    Energy Technology Data Exchange (ETDEWEB)

    Hoguet, Jean-Christophe; Karagiannakis, George P.; Valla, Julia A.; Agrafiotis, Christos C. [Aerosol and Particle Technology Laboratory, CERTH/CPERI, P.O. Box 361, 57001 Thermi, Thessaloniki (Greece); Konstandopoulos, Athanasios G. [Aerosol and Particle Technology Laboratory, CERTH/CPERI, P.O. Box 361, 57001 Thermi, Thessaloniki (Greece); Department of Chemical Engineering, Aristotle University, P.O. Box 1517, 54006 Thessaloniki (Greece)

    2009-06-15

    The present work focuses on the development of efficient desulphurization processes for multi-fuel reformers for hydrogen production. Two processes were studied: liquid hydrocarbon desulphurization and H{sub 2}S removal from reformate gases. For each process, materials with various chemical compositions and microporous structures were synthesized and characterized with respect to their physicochemical properties and desulphurization ability. In the case of liquid phase desulphurization, the adsorption of sulphur compounds contained in diesel fuel under ambient conditions was studied employing as sorbents, zeolite-based materials, i.e. NaY, HY and metal ion-exchanged NaY and HY, as well as a high-surface area activated carbon (AC), for three different diesel fuels with sulphur content varying between 5 and 180 ppmw. Among all sorbents studied, AC showed the best desulphurization performance followed by cerium ion-exchanged HY. The gas phase desulphurization experiments involved the evaluation of zinc-based mixed oxides, synthesized by non-conventional (combustion synthesis) techniques on high steam content reformate gas mixtures. (author)

  8. Scientific bases of biomass processing into basic component of aviation fuel

    Science.gov (United States)

    Kachalov, V. V.; Lavrenov, V. A.; Lishchiner, I. I.; Malova, O. V.; Tarasov, A. L.; Zaichenko, V. M.

    2016-11-01

    A combination of feedstock pyrolysis and the cracking of the volatile pyrolysis products on the charcoal at 1000 °C allows to obtain a tarless synthesis gas which contains 90 vol% or more of carbon monoxide and hydrogen in approximately equal proportions. Basic component of aviation fuel was synthesized in a two-stage process from gas obtained by pyrolytic processing of biomass. Methanol and dimethyl ether can be efficiently produced in a two-layer loading of methanolic catalyst and γ-Al2O3. The total conversion of CO per pass was 38.2% using for the synthesis of oxygenates a synthesis gas with adverse ratio of H2/CO = 0.96. Conversion of CO to CH3OH was 15.3% and the conversion of CO to dimethyl ether was 20.9%. A high yield of basic component per oxygenates mass (44.6%) was obtained during conversion. The high selectivity of the synthesis process for liquid hydrocarbons was observed. An optimal recipe of aviation fuel B-92 based on a synthesized basic component was developed. The prototype of aviation fuel meets the requirements for B-92 when straight fractions of 50-100 °C (up to 35 wt%), isooctane (up to 10 wt%) and ethyl fluid (2.0 g/kg calculated as tetraethyl lead) is added to the basic component.

  9. New processing methods to produce silicon carbide and beryllium oxide inert matrix and enhanced thermal conductivity oxide fuels

    Science.gov (United States)

    Sarma, K. H.; Fourcade, J.; Lee, S.-G.; Solomon, A. A.

    2006-06-01

    For inert matrix fuels, SiC and BeO represent two possible matrix phase compounds that exhibit very high thermal conductivity, high melting points, low neutron absorption, and reasonably high radiation stability. BeO is chemically compatible with UO2, PuO2 and Zircaloy to very high temperatures, but SiC reacts with all three at somewhat lower temperatures. We have developed the Polymer Impregnation and Pyrolysis or PIP method, making use of a commercial SiC polymeric precursor, to consolidate both particulate fuels like 'TRISO' microsphere fuels, and to impregnate UO2 fuels with pure stoichiometric SiC to improve their thermal conductivity. This method was employed to fabricate Enhanced Conductivity Oxide fuels, or ECO fuels with 5-10 vol.% of the high conductivity phase, and with 50 vol.% for TRISO dispersion fuels. For ECO fuels, a new 'slug/bisque' method of fabricating the UO2 fuel granules was necessary to produce sintered fuel with open pore structures, allowing almost complete impregnation of the continuous SiC phase. The advantages of the PIP process are that it is a non-damaging consolidation process for particulates (TRU, UC or TRISO microspheres), forms a continuous, pure β-SiC phase at temperatures as low as 1573 K, and allows the maximum in fissile atom density. However, several PIP impregnation cycles and high crystallization temperatures are necessary to obtain high thermal conductivity SiC. For producing IMF fuels using the PIP process, the fissile PuC and/or TRU actinides can be added in small concentrations along with SiC 'filler particles' and consolidated with the SiC precursor for either open or closed fuel cycles. For BeO, a second approach was developed for ECO fuels that involves a 'co-sintering' route to produce high density fuels with a continuous BeO phase of 5-10 vol.%. Special granulation and mixing techniques were developed, but only one normal sintering cycle is required. For BeO matrix IMF fuels, PuO2 granules and TRU actinides or

  10. The controls and consequences of substrate entrainment by pyroclastic density currents at Mount St Helens, Washington (USA)

    Science.gov (United States)

    Pollock, N. M.; Brand, B. D.; Roche, O.

    2016-10-01

    Evidence in the deposits from the May 18, 1980 eruption at Mount St Helens demonstrates that pyroclastic density currents (PDCs) produced during the afternoon of the eruption became intermittently erosive. Using detailed componentry and granulometry we constrain the sources for lithic blocks in the deposits and identify deposits from PDCs that became locally erosive. The componentry of the lithics in the fall deposits is used as a proxy for vent erosion and assumed to represent the starting componentry for PDCs prior to entrainment from any other source. We find little evidence in the PDC deposits nearest to the base of the volcano for entrainment from the steep flanks; however, significant evidence indicates that PDCs eroded into the debris avalanche hummocks, suggesting that entrainment is favored as PDCs interact with highly irregular topography. Evidence for locally entrained material downstream from debris avalanche hummocks decreases with height in the outcrop, suggesting that less entrainment occurs as local relief decreases and upstream topography is buried. The prevalence of lithofacies containing locally entrained material at the base of unit contacts and only 10s of meters downstream from debris avalanche hummocks suggests that the majority of entrainment occurs at or near the head of the current. Occasionally, entrained material is located high above unit contacts and deposited well after the initial head of the current is inferred to have passed, indicating that entrainment can occur during periods of non-deposition either from the semi-sustained body of the current or from a pulsating current. Additionally, self-channelization of PDCs, either by levee deposition or scouring into earlier PDC deposits, occurs independently of interaction with topographic obstacles and can affect carrying capacity and runout distance. While we begin to explore the mechanisms and effects of erosion on current dynamics, additional laboratory and numerical studies are

  11. Design strategies for P-containing fuels adaptable CeO2-MoO3 catalysts for DeNO(x): significance of phosphorus resistance and N2 selectivity.

    Science.gov (United States)

    Chang, Huazhen; Jong, Min Tze; Wang, Chizhong; Qu, Ruiyang; Du, Yu; Li, Junhua; Hao, Jiming

    2013-10-15

    Phosphorus compounds from flue gas have a significant deactivation effect on selective catalytic reduction (SCR) DeNOx catalysts. In this work, the effects of phosphorus over three catalysts (CeO2, CeO2-MoO3, and V2O5-MoO3/TiO2) for NH3-SCR were studied, and characterizations were performed aiming at a better understanding of the behavior and poisoning mechanism of phosphorus over SCR catalysts. The CeO2-MoO3 catalyst showed much better catalytic behavior with respect to resistance to phosphorus and N2 selectivity compared with V2O5-MoO3/TiO2 catalyst. With addition of 1.3 wt % P, the SCR activity of V2O5-MoO3/TiO2 decreased dramatically at low temperature due to the impairment of redox property for NO oxidation; meanwhile, the activity over CeO2 and CeO2-MoO3 catalysts was improved. The superior NO oxidation activity contributes to the activity over P-poisoned CeO2 catalyst. The increased surface area and abundant acidity sites contribute to excellent activity over CeO2-MoO3 catalyst. As the content of P increased to 3.9 wt %, the redox cycle over CeO2 catalyst (2CeO2 ↔ Ce2O3 + O*) was destroyed as phosphate accumulated, leading to the decline of SCR activity; whereas, more than 80% NOx conversion and superior N2 selectivity were obtained over CeO2-MoO3 at T > 300 °C. The effect of phosphorus was correlated with the redox properties of SCR catalyst for NH3 and NO oxidation. A spillover effect that phosphate transfers from Ce to Mo in calcination was proposed.

  12. The program cyberdiesel for mathematical modeling of fuel supply and local intracylinder processes in a diesel engine with volumetric carburetion

    OpenAIRE

    Maschenko, V. Yu.

    2007-01-01

    The program CyberDiesel is developed on the basis of complex mathematical model of fuel supply and local intracylinder processes in a diesel engine with volumetric carburetion. The program is intended for solving practical problems of coordinating constructive and adjusting parameters of fuel equipment and combustion chamber of a diesel engine by mathematical modeling methods.

  13. Effects of aqueous effluents from in situ fossil-fuel processing technologies on aquatic systems

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, H.L.

    1978-12-01

    Progress is reported for the second year of this project to evaluate the effects of aqueous effluents from in-situ fossil fuel processing technologies on aquatic biota. The project objectives for Year 2 were pursued through five tasks: literature reviews on process water constituents, possible environmental impacts and potential control technologies; toxicity bioassays on the effects of coal gasification and oil shale retorting process waters and six process water constituents on aquatic biota; biodegradation studies on process water constituents; bioaccumulation factor estimation for the compounds tested in the toxicity bioassays; and recommendations on maximum exposure concentrations for process water constituents based on data from the project and from the literature. Results in each of the five areas of research are reported.

  14. The Importance of Stochastic Effects for Explaining Entrainment in the Zebrafish Circadian Clock

    Directory of Open Access Journals (Sweden)

    Raphaela Heussen

    2015-01-01

    Full Text Available The circadian clock plays a pivotal role in modulating physiological processes and has been implicated, either directly or indirectly, in a range of pathological states including cancer. Here we investigate how the circadian clock is entrained by external cues such as light. Working with zebrafish cell lines and combining light pulse experiments with simulation efforts focused on the role of synchronization effects, we find that even very modest doses of light exposure are sufficient to trigger some entrainment, whereby a higher light intensity or duration correlates with strength of the circadian signal. Moreover, we observe in the simulations that stochastic effects may be considered an essential feature of the circadian clock in order to explain the circadian signal decay in prolonged darkness, as well as light initiated resynchronization as a strong component of entrainment.

  15. Removal of PCDDs/Fs from municipal solid waste incineration by entrained-flow adsorption technology

    Institute of Scientific and Technical Information of China (English)

    YAN Jian-hua; PENG Zheng; LU Sheng-yong; LI Xiao-dong; CEN Ke-fa

    2006-01-01

    Entrained flow adsorption using activated carbon as the adsorbent is widely adopted for PCDDs/Fs-abatement in municipal solidwaste incineration (MSWI) process. The effects of operating parameters including flue gas temperature, feeding rate of activated carbon, polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs) concentration at the inlet of the air pollution control device (APCD), filter materials, pressure drop on PCDDs/Fs removal efficiency are reviewed and commented upon in this paper. Evaluation on the various mechanistic models for entrained flow adsorption is carried out based on the computational simulation in terms of the actual operating condition and theoretical analysis. Finally, an advancement of entrained flow adsorption in combination of dual bag filter is introduced.

  16. Debris entrainment and landform genesis during tidewater glacier surges

    Science.gov (United States)

    Lovell, Harold; Fleming, Edward J.; Benn, Douglas I.; Hubbard, Bryn; Lukas, Sven; Rea, Brice R.; Noormets, Riko; Flink, Anne E.

    2015-08-01

    The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge-type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris-poor dispersed facies ice is the result of strain-induced metamorphism of meteoric ice near the bed. Debris-rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt-out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris-rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges.

  17. Computational fluid dynamics (CFD) analysis of the combustion process of a leather residuals gasification fuel gas: influence of fuel moisture content

    Energy Technology Data Exchange (ETDEWEB)

    Antonietti, Anderson Jose; Beskow, Arthur Bortolin; Silva, Cristiano Vitorino da [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: arthur@uricer.edu.br, mlsperb@unisinos.br; Indrusiak, Maria Luiza Sperb [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)], E-mail: cristiano@uricer.edu.br

    2010-07-01

    This work presents a numerical study of the combustion process of leather residuals gasification gas, aiming the improvement of the process efficiency, considering different concentrations of water on the gas. The heating produced in this combustion process can be used to generation of thermal and/or electrical energy, for use at the leather industrial plant. However, the direct burning of this leather-residual-gas into the chambers is not straightforward. The alternative in development consists in processing this leather residuals by gasification or pyrolysis, separating the volatiles and products of incomplete combustion, for after use as fuel in a boiler. At these processes, different quantities of water can be used, resulting at different levels of moisture content in this fuel gas. This humidity can affect significantly the burning of this fuel, producing unburnt gases, as the carbon monoxide, or toxic gases as NOx, which must have their production minimized on the process, with the purpose of reducing the emission of pollutants to the atmosphere. Other environment-harmful-gases, remaining of the chemical treatment employed at leather manufacture, as cyanide, and hydrocarbons as toluene, must burn too, and the moisture content has influence on it. At this way, to increase understanding of the influence of moisture in the combustion process, it was made a numerical investigation study of reacting flow in the furnace, evaluating the temperature field, the chemical species concentration fields, flow mechanics and heat transfer at the process. The commercial CFD code CFX Ansys Inc. was used. Considering different moisture contents in the fuel used on the combustion process, with this study was possible to achieve the most efficient burning operation parameters, with improvement of combustion efficiency, and reduction of environmental harmful gases emissions. It was verified that the different moisture contents in the fuel gas demand different operation conditions

  18. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics.

    Science.gov (United States)

    Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J

    2015-01-01

    Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette

  19. Continuous-Flow Processes in Heterogeneously Catalyzed Transformations of Biomass Derivatives into Fuels and Chemicals

    Directory of Open Access Journals (Sweden)

    Antonio A. Romero

    2012-07-01

    Full Text Available Continuous flow chemical processes offer several advantages as compared to batch chemistries. These are particularly relevant in the case of heterogeneously catalyzed transformations of biomass-derived platform molecules into valuable chemicals and fuels. This work is aimed to provide an overview of key continuous flow processes developed to date dealing with a series of transformations of platform chemicals including alcohols, furanics, organic acids and polyols using a wide range of heterogeneous catalysts based on supported metals, solid acids and bifunctional (metal + acidic materials.

  20. Application of a space-time CE/SE (Conversation Element/Solution Element) method to the numerical solution of chromatographic separation processes

    DEFF Research Database (Denmark)

    including convection-difmsion-reaction PDEs are numerically solved using the two methods on the same spatial grid. Even though the CE/SE method uses a simple stencil structure and is developed on a simple mathematical basis (i.e., Gauss' divergence theorem), accurate and computationally-efficient solutions......For solving partial differential equations (or distributed dynamic systems), the method of lines (MOL) and the space-time conservation element and solution element (CE/SE) method are compared in terms of computational efficiency, solution accuracy and stability. Several representative examples....... It is concluded that the CE/SE method is adequate to capturing shocks in PDEs but for diffusion-dominated stiff PDEs, the MOL with an ODE time integrator is complementary to the CE/SE method....

  1. Production of Biodiesel Fuel from Waste Soya bean Cooking Oil by Alkali Trans-esterification Process

    Directory of Open Access Journals (Sweden)

    Ajinkya Dipak Deshpande*,

    2016-04-01

    Full Text Available Biodiesel is biodegradable, clean-burning, non-toxic, renewable, high-quality, and cheap diesel fuel made primarily from waste vegetable oil which can be used without any alterations in engine design. The paper is concerned with the extraction and quality evaluation of the biodiesel fuels synthesized from waste soya bean cooking oil. Waste soya bean cooking oil had high amount of free fatty acid. Thus, single step transesterification process with the aid of homogeneous catalyst as 1% potassium hydroxide were implemented in this experiment. Methanol was chosen as alcohol solvent. In the transesterification process, the triglycerides in waste cooking oil was reacted with a methanol to form esters and glycerol as by product.The biodiesel were extracted for different oil to methanol ratio as 1:2, 1:3 and 1:4. The highest biodiesel yield of 76% was obtained at 1:3 volumetric ratio for 60 ºC reaction temperature and 1250 rpm stirring speed. Results show that the optimal methyl ester yield of 90% occurred at methanol: oil volume ratio of 3:1. The product met the ASTM fuel standards for relative density, acid value, relative density, calorific value, flash point and kinematic viscosity.

  2. Pyrometallurgical separation processes of radionuclides contained in the irradiated nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    De Cordoba, Guadalupe; Caravaca, Concha; Quinones, Javier; Gonzalez de la Huebra, Angel

    2005-01-01

    Faced with the new options for the high level waste management, the ''Partitioning and Transmutation (P and T)'' of the radio nuclides contained in the irradiated nuclear fuel appear as a promising option from different points of view, such as environmental risk, radiotoxic inventory reduction, economic, etc.. The present work is part of a research project called ''PYROREP'' of the 5th FWP of the EU that studied the feasibility of the actinide separation from the rest of fission products contained in the irradiated nuclear fuel by pyrometallurgical processes with the aim of their transmutation. In order to design these processes it is necessary to determine basic thermodynamic and kinetic data of the radionuclides contained in the nuclear fuel in molten salt media. The electrochemical study of uranium, samarium and molybdenum in the eutectic melt LiCl - KCl has been performed at a tungsten electrode in the temperature range of 450 - 600 deg C in order to obtain these basic properties. (Author)

  3. Oxygen Enrichment Effect of CeO2 to the Cathode Performance of Proton Exchange Membrane Fuel Cell%CeO2的富氧性能对质子交换膜燃料电池阴极的影响

    Institute of Scientific and Technical Information of China (English)

    侯向理; 徐洪峰; 董建华; 孙昕

    2006-01-01

    应用溶胶法和浸渍法向质子交换膜燃料电池阴极Pt/C催化剂添加CeO2,透射电子显微镜(TEM)分析和循环伏安测试表明:对由上述两种方法制备的各含5%CeO2的Pt/C催化剂,其粒径、形态分布以及CeO2在催化剂表面的覆盖度都不相同.单电池测试结果发现,二氧化铈的富氧作用表现明显,在以溶胶法制得的CeO2-Pt/C催化剂中,3% CeO2含量的催化剂呈现最佳的性能,而由浸渍法制得的CeO2-Pt/C,则以1%CeO2含量的性能最好,但对比之下,不如溶胶法制备的含3% CeO2的催化剂.

  4. Fuels for homogenous, self-igniting combustion processes; Brennstoffe fuer homogene selbstgezuendete Verbrennungsprozesse - Jahresbericht 2007

    Energy Technology Data Exchange (ETDEWEB)

    Escher, A.; Boulouchos, K.

    2007-07-01

    This annual report for the Swiss Federal Office of Energy (SFOE), reports on work done in 2007 at the Swiss Federal Institute of Technology ETH in Zurich, Switzerland, on fuels for homogenous, self-igniting combustion processes. A single-stroke engine was used to test the combustion of n-heptane, n-butane and their combinations. The flexibility of the test-bed is discussed and the combustion characteristics observed are described. Also, the results obtained are presented and discussed. Multi-zone simulation and factors influencing the combustion are examined. Ignition and combustion of synthetic, diesel-like fuels are discussed. Co-operation with the project started in 2007 by the Society for Research on Combustion Engines which involves other universities and several industrial companies is noted.

  5. Numerical solution of moving boundary problem for deposition process in solid fuel gas generator

    Science.gov (United States)

    Volokhov, V. M.; Dorofeenko, S. O.; Sharov, M. S.; Toktaliev, P. D.

    2016-11-01

    Moving boundary problem in application to process of depositions formation in gas generator are considered. Gas generator, as a part of fuel preparation system of high-speed vehicle, convert solid fuel into multicomponent multiphase mixture, which further burned down in combustion chamber. Mathematical model of two-phase “gas-solid particles” flow, including Navier-Stokes equations for turbulent flow in gas generator and mass, impulse conservations laws for elementary depositions layer are proposed. Verification of proposed mathematical model for depositions mass in gas generator conditions is done. Further possible improvements of proposed model, based on more detail accounting of particle-wall interaction and wall's surface adhesion properties are analyzed.

  6. Characterization of U Nb Zr dispersion fuel prepared by centrifugal atomization process

    Science.gov (United States)

    Park, Jong-Man; Kim, Ki-Hwan; Sohn, Dong-Seong; Kim, Chang-Kyu; Hofman, Gerard L.

    1999-02-01

    The dispersions of U-Nb-Zr alloy particles in aluminum were characterized in order to assess the applicability of this dispersion as research reactor fuel. Heat treatment revealed that the 9 wt% Nb alloy powder had, as expected, higher γ-phase stability that the 5 wt% Nb alloy powder. A lamellar structure consisting of an α-U phase and γ-phase was observed to start at the grain boundaries during heat treatment. The U-Nb-Zr alloy dispersion exhibited large volume increases during annealing when compared with similar experimental results for U 3Si, U 3Si 2 and U-Mo dispersion fuel systems. The reaction product (U,Nb,Zr)Al 3 forms preferentially by diffusion of aluminum in the α-U phase which, in turn, forms during the diffusion process as the metastable γ-phase decomposes.

  7. The development of technical database of advanced spent fuel management process

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Seung Gy; Byeon, Kee Hoh; Song, Dae Yong; Park, Seong Won; Shin, Young Jun

    1999-03-01

    The purpose of this study is to develop the technical database system to provide useful information to researchers who study on the back end nuclear fuel cycle. Technical database of advanced spent fuel management process was developed for a prototype system in 1997. In 1998, this database system is improved into multi-user systems and appended special database which is composed of thermochemical formation data and reaction data. In this report, the detailed specification of our system design is described and the operating methods are illustrated as a user's manual. Also, expanding current system, or interfacing between this system and other system, this report is very useful as a reference. (Author). 10 refs., 18 tabs., 46 fig.

  8. New Approach to Study the Ignition Processes of Organic Coal-Water Fuels in an Oxidizer Flow

    Directory of Open Access Journals (Sweden)

    Valiullin T.R.

    2016-01-01

    Full Text Available To converge the conditions of organic water-coal fuel composition combustion in the typical power equipment we developed a new approach and installed an experimental setup, eliminating the traditional fixing the fuel droplets on the thermocouples or rods. Specialized cone-shaped chamber was used to implement the process of lingering of organic water-coal fuel droplets. Necessary and sufficient conditions for the lingering of organic water-coal fuel droplets were established. We determined the parameters of the system (droplet size of 0.4-0.6 mm, temperatures 823-903 K and the velocity of the oxidizer flow 1.5-6 m/s at which the droplets were consistently ignited in the process of lingering. Minimum temperatures and ignition delay times of organic water-coal fuel droplets based on brown coal, used motor, turbine, transformer oils, kerosene, gasoline and water were defined.

  9. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-01-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  10. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates.

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-07-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  11. ACSEPT a European project for a new step in the future demonstration of advanced fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, S.; Hill, C. [CEA, DRCP - Bat 181, CEA Marcoule, BP17171, 30207 Bagnols/Ceze (France); Caravaca, C.; Espartero, A. [CIEMAT, Avda. Complutense, 22 - 28040 Madrid (Spain); Rhodes, C.; Taylor, R.; Harrison, M. [National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom); EKBERG, C. [Chalmers tekniska hoegskola, Institutionen foer kemi- och bioteknik, Aemnesomraadets namn, 412 96 Goeteborg (Sweden); GEIST, A. [Forschungszentrum Karlsruhe, Institut fuer Nukleare Entsorgungstechnik, P.O.B. 3640, D-76021 Karlsruhe (Germany); Modolo, G. [Forschungszentrum Juelich - FZJ, D-52425 Juelich (Germany); Cassayre, L. [CNRS, Laboratoire de Genie Chimique, Toulouse (France); Malmbeck, R. [JRC-ITU, Karlsruhe (Germany); De Angelis, G. [ENEA, Casaccia, Rome (Italy); Bouvet, S. [Rio Tinto Alcan, Centre de Recherche de Voreppe, Voreppe (France); Klaassen, F. [NRG, PO Box 25, NL-1755 ZG Petten (Netherlands)

    2010-07-01

    For more than fifteen years, a European scientific community has joined its effort to develop and optimise processes for the partitioning of actinides from fission products. In an international context of 'nuclear renaissance', the upcoming of a new generation of nuclear reactor (Gen IV) will require the development of associated advanced closed fuel cycles which answer the needs of a sustainable nuclear energy: the minimization of the production of long lived radioactive waste but also the optimization of the use of natural resources with an increased resistance to proliferation. Actually, Partitioning and Transmutation (P and T), associated to a multi-recycling of all transuranics (TRUs), should play a key role in the development of this sustainable nuclear energy. By joining together 34 Partners coming from European universities, nuclear research bodies and major industrial players in a multidisciplinary consortium, the FP7 EURATOM-Fission Collaborative Project ACSEPT (Actinide recycling by Separation and Transmutation), started in 2008 for four year duration, provides the sound basis and fundamental improvements for future demonstrations of fuel treatment in strong connection with fuel fabrication techniques. Consistently with potentially viable recycling strategies, ACSEPT therefore provides a structured R and D framework to develop chemical separation processes compatible with fuel fabrication techniques, with a view to their future demonstration at the pilot level. ACSEPT is organized into three technical domains: (i) Considering technically mature aqueous separation processes, ACSEPT works to optimize and select the most promising ones dedicated either to actinide partitioning or to group actinide separation. (ii) Concerning high temperature pyrochemical separation processes, ACSEPT focuses on the enhancement of the two reference cores of process selected within previous projects. R and D efforts are now devoted to key scientific and technical

  12. Fuel and power coproduction: The Liquid Phase Methanol (LPMEOH{trademark}) process demonstration at Kingsport

    Energy Technology Data Exchange (ETDEWEB)

    Drown, D.P.; Brown, W.R.; Heydorn, E.C.; Moore, R.B.; Schaub, E.S.; Brown, D.M.; Jones, W.C.; Kornosky, R.M.

    1997-12-31

    The Liquid Phase Methanol (LPMEOH{trademark}) process uses a slurry bubble column reactor to convert syngas (primarily a mixture of carbon monoxide and hydrogen) to methanol. Because of its superior heat management, the process is able to be designed to directly handle the carbon monoxide (CO)-rich syngas characteristic of the gasification of coal, petroleum coke, residual oil, wastes, or of other hydrocarbon feedstocks. When added to an integrated gasification combined cycle (IGCC) power plant, the LPMEOH{trademark} process converts a portion of the CO-rich syngas produced by the gasifier to methanol, and the remainder of the unconverted gas is used to fuel the gas turbine combined-cycle power plant. The LPMEOH{trademark} process has the flexibility to operate in a daily electricity demand load-following manner. Coproduction of power and methanol via IGCC and the LPMEOH{trademark} process provides opportunities for energy storage for electrical demand peak shaving, clean fuel for export, and/or chemical methanol sales.

  13. Processing of mixed uranium/refractory metal carbide fuels for high temperature space nuclear reactors

    Science.gov (United States)

    Knight, Travis; Anghaie, Samim

    2000-01-01

    Single phase, solid-solution mixed uranium/refractory metal carbides have been proposed as an advanced nuclear fuel for high performance, next generation space power and propulsion systems. These mixed carbides such as the pseudo-ternary, (U, Zr, Nb)C, hold significant promise because of their high melting points (typically greater than 3200 K), thermochemical stability in a hot hydrogen environment, and high thermal conductivity. However, insufficient test data exist under nuclear thermal propulsion conditions of temperature and hot hydrogen environment to fully evaluate their performance. Various compositions of (U, Zr, Nb)C were processed with 5% and 10% metal mole fraction of uranium. Stoichiometric samples were processed from the constituent carbide powders while hypostoichiometric samples with carbon-to-metal (C/M) ratios of 0.95 were processed from uranium hydride, graphite, and constituent refractory carbide powders. Processing techniques of cold pressing, sintering, and hot pressing were investigated to optimize the processing parameters necessary to produce dense (low porosity), homogeneous, single phase, solid-solution mixed carbide nuclear fuels for testing. This investigation was undertaken to evaluate and characterize the performance of these mixed uranium/refractory metal carbides for space power and propulsion applications. .

  14. Study on Spray Characteristics and Spray Droplets Dynamic Behavior of Diesel Engine Fueled by Rapeseed Oil

    Directory of Open Access Journals (Sweden)

    Sapit Azwan

    2014-07-01

    Full Text Available Fuel-air mixing is important process in diesel combustion. It directly affects the combustion and emission of diesel engine. Biomass fuel needs great help to atomize because the fuel has high viscosity and high distillation temperature. This study investigates the atomization characteristics and droplet dynamic behaviors of diesel engine spray fueled by rapeseed oil (RO. Optical observation of RO spray was carried out using shadowgraph photography technique. Single nano-spark photography technique was used to study the characteristics of the rapeseed oil spray while dual nano-spark shadowgraph technique was used to study the spray droplet behavior. The results show that RO has very poor atomization due to the high viscosity nature of the fuel. This is in agreement with the results from spray droplet dynamic behavior studies that shows due to the high viscosity, the droplets are large in size and travel downward, with very little influence of entrainment effect due to its large kinematic energy.

  15. On the mechanism of air entrainment by liquid jets at a free surface

    NARCIS (Netherlands)

    Zhu, Yonggang; Oguz, Hasan N.; Prosperetti, Andrea

    2000-01-01

    The process by which a liquid jet falling into a liquid pool entrains air is studied experimentally and theoretically. It is shown that, provided the nozzle from which the jet issues is properly contoured, an undisturbed jet does not entrap air even at relatively high Reynolds numbers. When surface

  16. Exergy analysis of rice husk gasification process in entrained-flow reactor%携带流反应器中稻壳气化过程的炯分析

    Institute of Scientific and Technical Information of China (English)

    张亚宁; 赵义军; 孙绍增; 李炳熙

    2012-01-01

    Effect of air equivalence ratio ER on rice husk gasification in an entrained-flow reactor at different temperatures is analyzed using exergy concept. The results show that the contribution of gas component to exergy value is as follows: CO>H2>CH4> (N2, C2H4, CO2). With ER goes up the exergy value and its efficiency increase first and then decrease for product gas, however, the residual ratio and exergy efficiency decline first and then augment for unreacted carbon. At ER 0. 25 and reactor temperature 1000℃, total exergy value and exergy efficiency of product gas are 7983. 95 kJ · kg-1 and 54. 35%, respectively, and at ER 0. 28 and temperature 1000℃ , the residual ratio and exergy efficiency of unreacted carbon are 24. 82% and 21. 49%, respectively. Raising temperature can lift exergy value and exergy efficiency of product gas, but reduce residual ratio and exergy efficiency of unreacted carbon.%引 言生物质能作为一种可再生的清洁能源,可以减少CO2、NOx、SOx及颗粒物的排放[1],其开发利用受到世界各国的极大关注[2].生物质气化被认为是生物质利用的最有前途的能源转化方式之一[3],已经成为能源研发与利用的一大研究热点.研究结果表明,气化器或者锅炉是能源转化和利用过程中效率最低的一个操作单元[4],因此,气化器效率的提高能在很大程度上改善整个能源转化过程[5].

  17. An Observational Study of Entrainment Rate in Deep Convection

    OpenAIRE

    Xiaohao Guo; Chunsong Lu; Tianliang Zhao; Guang J. Zhang; Yangang Liu

    2015-01-01

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects...

  18. Atenção Pré-Natal no Município de Quixadá-CE segundo indicadores de processo do SISPRENATAL Atención prenatal en el municipio de Quixadá-CE según indicadores de proceso del SISPRENATAL Prenatal care in Quixadá-CE according to SISPRENATAL's process indicators

    Directory of Open Access Journals (Sweden)

    Gisele Ribeiro Grangeiro

    2008-03-01

    Full Text Available Pesquisa descritiva, documental, que objetivou analisar os indicadores de processo do Sistema de Informação do Pré-natal (SISPRENATAL, em Quixadá-CE. Estudaram-se 1.544 cadastros de gestantes no período de 2001 a 2004. Os dados foram coletados de fevereiro a abril de 2005 no SISPRENATAL, implantado no setor de Epidemiologia da Secretaria Municipal de Saúde. Os resultados foram apresentados em tabela única e analisados à luz da literatura atual e experiência acumulada das autoras. Verificou-se percentual crescente de gestantes com indicador de, no mínimo, seis consultas, todos os exames básicos, teste anti-HIV, imunização antitetânica e consulta puerperal de 2001 a 2004, ou seja, zero, 2,6, 5,68 e 21,11%, respectivamente. É necessário, pois, uma melhora na utilização do Sistema, assim como a leitura sistemática dos indicadores de processo, no sentido de obter subsídios para a melhoria da qualidade da assistência pré-natal.En esta Investigación descriptiva, documental se tuvo como objetivo analizar los indicadores de proceso del Sistema de Información del Prenatal (SISPRENATAL, el el municipio de Quixadá-CE. Fueron estudiados 1.544 registros de mujeres embarazadas en el período de 2001 a 2004. Los datos fueron recolectados de febrero a abril del 2005 en el SISPRENATAL, en el sector de Epidemiología de la Secretaría Municipal de Salud. Los resultados fueron presentados sólo en una tabla y analizados a la luz de la literatura actual y también a partir de las experiencias de las autoras. Se verificó el porcentaje creciente de mujeres embarazadas con indicador mínimo de seis consultas, todos los exámenes básicos, test anti-VIH, inmunización antitetánica y consulta puerperal de 2001 a 2004, es decir, cero, 2,6, 5,68 e 21,11%, respectivamente. Es necesario, pues, una mejor utilización del Sistema, y también una lectura sistemática de los indicadores de proceso para obtener soporte para la mejoría de la calidad de

  19. An Observational Study of Entrainment Rate in Deep Convection

    Directory of Open Access Journals (Sweden)

    Xiaohao Guo

    2015-09-01

    Full Text Available This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. In addition, entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  20. Establishment and assessment of a novel cleaner production process of corn grain fuel ethanol.

    Science.gov (United States)

    Wang, Ke; Zhang, Jianhua; Tang, Lei; Zhang, Hongjian; Zhang, Guiying; Yang, Xizhao; Liu, Pei; Mao, Zhonggui

    2013-11-01

    An integrated corn ethanol-methane fermentation system was proposed to solve the problem of stillage handling, where thin stillage was treated by anaerobic digestion and then reused to make mash for the following ethanol fermentation. This system was evaluated at laboratory and pilot scale. Anaerobic digestion of thin stillage ran steadily with total chemical oxygen demand removal efficiency of 98% at laboratory scale and 97% at pilot scale. Ethanol production was not influenced by recycling anaerobic digestion effluent at laboratory and pilot scale. Compared with dried distillers' grains with solubles produced in conventional process, dried distillers' grains in the proposed system exhibited higher quality because of increased protein concentration and decreased salts concentration. Energetic assessment indicated that application of this novel process enhanced the net energy balance ratio from 1.26 (conventional process) to 1.76. In conclusion, the proposed system possessed technical advantage over the conventional process for corn fuel ethanol production.

  1. China's fuel economy standards for passenger vehicles: Rationale, policy process, and impacts

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Hongyan H., E-mail: hongyan.oliver@gmail.co [John F. Kennedy School of Government, Harvard University, 79 JFK Street, Cambridge, MA 02138 (United States); Gallagher, Kelly Sims [John F. Kennedy School of Government, Harvard University, 79 JFK Street, Cambridge, MA 02138 (United States); Tian Donglian; Zhang Jinhua [China Automotive Technology and Research Center, No. 188 Western Road, 4th South Ring Road, Fengtai District, Beijing 100070 (China)

    2009-11-15

    China issued its first Fuel Economy Standards (FES) for light-duty passenger vehicles (LDPV) in September 2004, and the first and second phases of the FES took effective in July 2005 and January 2008, respectively. The stringency of the Chinese FES ranks third globally, following the Japanese and European standards. In this paper, we first review the policy-making background, including the motivations, key players, and the process; and then explain the content and the features of the FES and why there was no compliance flexibility built into it. Next, we assess the various aspects of the standard's impact, including fuel economy improvement, technology changes, shift of market composition, and overall fuel savings. Lastly, we comment on the prospect of tightening the existing FES and summarize the complementary policies that have been adopted or may be considered by the Chinese government for further promoting efficient vehicles and reducing transport energy consumption. The Chinese experience is highly relevant for countries that are also experiencing or anticipating rapid growth in personal vehicles, those wishing to moderate an increase in oil demand, or those desirous of vehicle technology upgrades.

  2. China's fuel economy standards for passenger vehicles. Rationale, policy process, and impacts

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Hongyan H.; Gallagher, Kelly Sims [John F. Kennedy School of Government, Harvard University, 79 JFK Street, Cambridge, MA 02138 (United States); Tian, Donglian; Zhang, Jinhua [China Automotive Technology and Research Center, No. 188 Western Road, 4th South Ring Road, Fengtai District, Beijing 100070 (China)

    2009-11-15

    China issued its first Fuel Economy Standards (FES) for light-duty passenger vehicles (LDPV) in September 2004, and the first and second phases of the FES took effective in July 2005 and January 2008, respectively. The stringency of the Chinese FES ranks third globally, following the Japanese and European standards. In this paper, we first review the policy-making background, including the motivations, key players, and the process; and then explain the content and the features of the FES and why there was no compliance flexibility built into it. Next, we assess the various aspects of the standard's impact, including fuel economy improvement, technology changes, shift of market composition, and overall fuel savings. Lastly, we comment on the prospect of tightening the existing FES and summarize the complementary policies that have been adopted or may be considered by the Chinese government for further promoting efficient vehicles and reducing transport energy consumption. The Chinese experience is highly relevant for countries that are also experiencing or anticipating rapid growth in personal vehicles, those wishing to moderate an increase in oil demand, or those desirous of vehicle technology upgrades. (author)

  3. Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    E.T. Robinson; John Sirman; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Dan Corgard; John Hemmings

    2005-05-01

    This final report summarizes work accomplished in the Program from January 1, 2001 through December 31, 2004. Most of the key technical objectives for this program were achieved. A breakthrough material system has lead to the development of an OTM (oxygen transport membrane) compact planar reactor design capable of producing either syngas or hydrogen. The planar reactor shows significant advantages in thermal efficiency and a step change reduction in costs compared to either autothermal reforming or steam methane reforming with CO{sub 2} recovery. Syngas derived ultra-clean transportation fuels were tested in the Nuvera fuel cell modular pressurized reactor and in International Truck and Engine single cylinder test engines. The studies compared emission and engine performance of conventional base fuels to various formulations of ultra-clean gasoline or diesel fuels. A proprietary BP oxygenate showed significant advantage in both applications for reducing emissions with minimal impact on performance. In addition, a study to evaluate new fuel formulations for an HCCI engine was completed.

  4. DEVELOPMENT OF LOW-COST MANUFACTURING PROCESSES FOR PLANAR, MULTILAYER SOLID OXIDE FUEL CELL ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Matthew Seabaugh; William Dawson; Harlan Anderson; Tim Armstrong; Michael Cobb; Kirby Meacham; James Stephan; Russell Bennett; Bob Remick; Chuck Sishtla; Scott Barnett; John Lannutti

    2004-06-12

    This report summarizes the results of a four-year project, entitled, ''Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells'', jointly funded by the U.S. Department of Energy, the State of Ohio, and by project participants. The project was led by NexTech Materials, Ltd., with subcontracting support provided by University of Missouri-Rolla, Michael A. Cobb & Co., Advanced Materials Technologies, Inc., Edison Materials Technology Center, Gas Technology Institute, Northwestern University, and The Ohio State University. Oak Ridge National Laboratory, though not formally a subcontractor on the program, supported the effort with separate DOE funding. The objective of the program was to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. The program was carried out in three phases. In the Phase I effort, several manufacturing approaches were considered and subjected to detailed assessments of manufacturability and development risk. Estimated manufacturing costs for 5-kW stacks were in the range of $139/kW to $179/kW. The risk assessment identified a number of technical issues that would need to be considered during development. Phase II development work focused on development of planar solid oxide fuel cell elements, using a number of ceramic manufacturing methods, including tape casting, colloidal-spray deposition, screen printing, spin-coating, and sintering. Several processes were successfully established for fabrication of anode-supported, thin-film electrolyte cells, with performance levels at or near the state-of-the-art. The work in Phase III involved scale-up of cell manufacturing methods, development of non-destructive evaluation methods, and comprehensive electrical and electrochemical testing of solid oxide fuel cell materials and components.

  5. Preparation,Characterization of CuO/CeO2 and Cu/CeO2 Catalysts and Their Applications in Low-Temperature CO Oxidation

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiucheng; Han Dongzhan; Wang Shuping; Zhang Shoumin; Wang Shurong; Huang Weiping; Wu Shihua

    2005-01-01

    CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were examined by means of a microreactor-GC system, HRTEM, XRD, TPR and XPS techniques. The results show that CuO has not catalytic activity and the activity of CeO2 is quite low for CO oxidation. However, the catalytic activity of CuO/CeO2 and Cu/CeO2 catalysts increases significantly. Furthermore, the activity of CuO/CeO2 is higher than that of Cu/CeO2 catalysts.

  6. Geological Disposal Options for the Radioactive Wastes from a Recycling Process of Spent Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. Y.; Choi, H. J.; Lee, M. S.; Jeong, J. T.; Choi, J. W.; Kim, S. K.; Cho, D. K.; Kuk, D. H.; Cha, J. H

    2008-10-15

    The electricity from the nuclear power plants is around 40 % of total required electricity in Korea and according to the energy development plan, the proportion will be raised about 60 % in near future. To implement this plan, the most important factor is the back-end fuel cycle, namely the safe management of the spent fuel or high level radioactive wastes from the nuclear power plants. Various researches are being carried out to manage the spent fuel effectively in the world. In our country, as one of the management alternatives which is more effective and non-proliferation, pyro-processing method is being developed actively to retrieve reusable uranium and TRU, and to reduce the volume of high level waste from a Nuclear power plant. This is a new dry recycling process. In this report, the amount of various wastes and their characteristics are estimated in a Pyro-process. Based on these information, the geological disposal alternatives are developed. According to the amount and the characteristics of each waste, the concepts of waste packages and the disposal container are developed. And also from the characteristics of the radioactivity and the heat generation, multi-layer of the depth is considered to dispose these wastes. The proposed various alternatives in this report can be used as input data for design of the deep geological disposal system. And they will be improved through the application of the real site data and safety assessment in the future. After then, the final disposal concept will be selected with various assessment and the optimization will be carried out.

  7. Enhancement of photocatalytic activity of combustion-synthesized CeO{sub 2}/C{sub 3}N{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing [Hunan University, Department of Applied Physics, School of Physics and Electronics, Changsha (China)

    2015-09-15

    Nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C{sub 3}N{sub 4} and CeO{sub 2} in the photocatalytic process. (orig.)

  8. Methane reforming With CO2 to syngas over CeO2-promoted Ni/Al2O3-ZrO2 catalysts Prepared Via a direct sol-gel process

    Institute of Scientific and Technical Information of China (English)

    Hansheng Li; Hang Xu; Jinfu Wang

    2011-01-01

    CeO2-promoted Ni/Al2O3-ZrO2 (Ni/Al2O3-ZrO2-CeO2) catalysts were prepared by a direct sol-gel process with citric acid as gelling agent.The catalysts used for the methane reforming with CO2 was studied by infrared spectroscopy (IR), thermal gravimetric analysis (TGA), microscopic analysis, X-ray diffraction (XRD) and temperature-programmed reduction (TPR).The catalytic performance for CO2 reforming of methane to synthesis gas was investigated in a continuous-flow micro-reactor under atmospheric pressure.TGA, IR, XRD and microscopic analysis show that the catalysts prepared by the direct sol-gel process consist of Ni particles with a nanostructure of around 5 nm and an amorphous-phase composite oxide support.There exists a chemical interaction between metallic Ni particles and supports, which makes metallic Ni well dispersed, highly active and stable.The addition of CeO2 effectively improves the dispersion and the stability of Ni particles of the prepared catalysts, and enhances the adsorption of CO2 on the surface of catalysts.The catalytic tests for methane reforming with CO2 to synthesis gas show that the Ni/Al2O3-ZrO2-CeO2 catalysts show excellent activity and stability compared with the Ni/Al2O3 catalyst.The excellent catalytic activity and stability of the Ni/Al2O3-ZrO2-CeO2 are attributed to the highly, uniformly and stably dispersed small metallic Ni particles, the high reducibility of the Ni oxides and the interaction between metallic Ni particles and the composite oxide supports.

  9. Fundamental phenomena on fuel decomposition and boundary-layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Yeu-Cherng; Chiaverini, Martin J.; Harting, George C.; Johnson, David K.; Serin, Nadir

    1995-01-01

    The experimental study on the fundamental processes involved in fuel decomposition and boundary-layer combustion in hybrid rocket motors is continuously being conducted at the High Pressure Combustion Laboratory of The Pennsylvania State University. This research will provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high-pressure, 2-D slab motor has been designed, manufactured, and utilized for conducting seven test firings using HTPB fuel processed at PSU. A total of 20 fuel slabs have been received from the Mcdonnell Douglas Aerospace Corporation. Ten of these fuel slabs contain an array of fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. Diagnostic instrumentation used in the test include high-frequency pressure transducers for measuring static and dynamic motor pressures and fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. The ultrasonic pulse-echo technique as well as a real-time x-ray radiography system have been used to obtain independent measurements of instantaneous solid fuel regression rates.

  10. Engineering bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.

    2014-01-01

    A comparison between two numerical models describing the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. Both models consider the incoming biomass as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed...... of the syngas predicted by the two models is equal to about 7%. The application to different types of biomass shows that the difference in the predictions increases as the carbon content grows. The phenomenological model, in fact, generally considers higher conversion rates of this element to volatiles...

  11. Significance of chamber pressure to complex multi-phase physics in jet engine fuel injection processes

    Science.gov (United States)

    Dahms, Rainer; Oefelein, Joseph

    2014-11-01

    Injection processes in jet engines at chamber pressures in excess of the thermodynamic critical pressure of the liquid fuel are not well understood. Under some conditions, a distinct two-phase interface may not exist anymore which eliminates the presence of classical spray atomization phenomena. A comprehensive model for jet engine fuel injections is derived to quantify the conditions under which the interfacial dynamics transition to diffusion-dominated mixing processes without surface tension. At certain conditions, the model shows two-phase interfaces with substantially increased thicknesses and distinctively reduced mean free paths in comparison to ambient pressure conditions. Then, the underlying assumptions of a distinct two-phase interface do not apply anymore and the interface along with its surface tension is shown to deteriorate as it broadens substantially. As a consequence of this physical complexity, the conceptual view of spray atomization and evaporation as an appropriate model for jet engine injection processes is, contrary to conventional wisdom, questionable at certain operating conditions. Instead, a Large Eddy Simulation using a dense-fluid approximation is applied which takes the complex thermo-physics of real-fluid behavior into account.

  12. Down Select Report of Chemical Hydrogen Storage Materials, Catalysts, and Spent Fuel Regeneration Processes

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Kevin; Linehan, Sue; Lipiecki, Frank; Aardahl, Christopher L.

    2008-08-24

    The DOE Hydrogen Storage Program is focused on identifying and developing viable hydrogen storage systems for onboard vehicular applications. The program funds exploratory research directed at identifying new materials and concepts for storage of hydrogen having high gravimetric and volumetric capacities that have the potential to meet long term technical targets for onboard storage. Approaches currently being examined are reversible metal hydride storage materials, reversible hydrogen sorption systems, and chemical hydrogen storage systems. The latter approach concerns materials that release hydrogen in endothermic or exothermic chemical bond-breaking processes. To regenerate the spent fuels arising from hydrogen release from such materials, chemical processes must be employed. These chemical regeneration processes are envisioned to occur offboard the vehicle.

  13. Limitation of the EIA Process for the assessment of nuclear fuel waste disposal in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, B.L.; Kuhn, R.G. [Guelph Univ., ON (Canada). Dept. of Geography

    1999-12-01

    The Canadian environmental impact assessment process for the Nuclear Fuel Waste Management and Disposal Concept was completed in 1994. Almost four years later, in February 1998, the Review Panel released its report. The viewpoints of those who participated in the assessment process is archived in the thousands of pages of hearing testimony, meeting transcripts and written briefs. One of the most contentious issues raised, and one that continues to plague management in Canada, is the debate surrounding how the problem of NFW waste management should be defined. The purpose of this paper is to critically assess the problem frame of the Canadian NFW management disposal concept EIS. This will be accomplished through an analysis of stakeholder participation and views, and through an evaluation of the range and nature of the information considered legitimate or constrained in the Canadian process.

  14. Cracking and hydrocracking of triglycerides for renewable liquid fuels: alternative processes to transesterification

    Energy Technology Data Exchange (ETDEWEB)

    Frety, Roger; Rocha, Maria da Graca C. da; Brandao, Soraia T., E-mail: frety@unifacs.b [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Pontes, Luiz A.M; Padilha, Jose F. [Universidade de Salvador (UNIFACS), BA (Brazil); Borges, Luiz E.P.; Gonzalez, Wilma A. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Quimica

    2011-07-01

    The most used industrial processes for the production of liquid fuels like diesel type are based on the methanolysis and ethanolysis of various oil reactants, such as palm, soybean and rapeseed oils, in the presence of homogeneous base catalysts. However, thermal and catalytic transformations of vegetable oils using available reactors and industrial processes are possible alternatives and deserve attention. In fact, three industrial processes are operating and new projects are announced. The present work analyses the experimental studies performed up to now by Brazilian researchers in the field of cracking, catalytic cracking and hydrocracking of pure or modified vegetable oils. From the published results, some research areas for the near future are suggested. (author)

  15. Phase-selective entrainment of nonlinear oscillator ensembles

    Science.gov (United States)

    Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z.; Li-Shin, Jr.

    2016-03-01

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.

  16. The Welding Process of the Small In-pile Testing Fuel Assembly

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The small in-pile testing fuel assembly is designed for high performance fuel assembly study. It has two parts of which are four fuel element with double layer cladding and a detect system for measurement of testing pressure and temperature. The fuel element is composed of UO2 pellets, the stainless steel cladding and end caps. The detect system is direct contact with the fuel element by electron beam welding. In the fabrication of the assembly, some special welding technologies are

  17. The formation of intermetallic compounds during interdiffusion of Mg–Al/Mg–Ce diffusion couples

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jiahong [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Jiang, Bin, E-mail: jiangbinrong@cqu.edu.cn [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Li, Xin [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Yang, Qingshan [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Dong, Hanwu [Chongqing Academy of Science and Technology, Chongqing 401123 (China); Xia, Xiangsheng [No. 59 Institute of China Ordnance Industry, Chongqing 400039 (China); Pan, Fusheng [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China)

    2015-01-15

    Graphical abstract: Al–Ce intermetallic compounds (IMCs) formed in Mg–Al/Mg–Ce diffusion couples. During the whole diffusion process, Al was the dominant diffusing species, and it substituted for Mg atoms of the Mg–Ce substrate. Five Al–Ce IMCs of Al{sub 4}Ce, Al{sub 11}Ce{sub 3}, Al{sub 3}Ce, Al{sub 2}Ce, and AlCe were formed via the reaction of Al and Ce. - Highlights: • Al–Ce IMCs formation in the Mg–Al/Mg–Ce diffusion couples was studied. • Formation of Al{sub 4}Ce as the first phase was rationalized using the Gibbs free energy. • The activation energy for the growth of the diffusion reaction zones was 36.6 kJ/mol. - Abstract: The formation of Al–Ce intermetallic compounds (IMCs) during interdiffusion of Mg–Al/Mg–Ce diffusion couples prepared by solid–liquid contact method was investigated at 623 K, 648 K and 673 K for 24 h, 48 h and 72 h, respectively. During the whole diffusion process, Al was the dominant diffusing species, and it substituted for Mg of the Mg–Ce substrate. Five Al–Ce IMCs of Al{sub 4}Ce, Al{sub 11}Ce{sub 3}, Al{sub 3}Ce, Al{sub 2}Ce and AlCe were formed via the reaction of Al and Ce. The formation of Al{sub 4}Ce as the first kind of IMC was rationalized on the basis of an effective Gibbs free energy model. The activation energy for the growth of the total diffusion reaction layer was 36.6 kJ/mol.

  18. Out-of-synchrony speech entrainment in developmental dyslexia.

    Science.gov (United States)

    Molinaro, Nicola; Lizarazu, Mikel; Lallier, Marie; Bourguignon, Mathieu; Carreiras, Manuel

    2016-08-01

    Developmental dyslexia is a reading disorder often characterized by reduced awareness of speech units. Whether the neural source of this phonological disorder in dyslexic readers results from the malfunctioning of the primary auditory system or damaged feedback communication between higher-order phonological regions (i.e., left inferior frontal regions) and the auditory cortex is still under dispute. Here we recorded magnetoencephalographic (MEG) signals from 20 dyslexic readers and 20 age-matched controls while they were listening to ∼10-s-long spoken sentences. Compared to controls, dyslexic readers had (1) an impaired neural entrainment to speech in the delta band (0.5-1 Hz); (2) a reduced delta synchronization in both the right auditory cortex and the left inferior frontal gyrus; and (3) an impaired feedforward functional coupling between neural oscillations in the right auditory cortex and the left inferior frontal regions. This shows that during speech listening, individuals with developmental dyslexia present reduced neural synchrony to low-frequency speech oscillations in primary auditory regions that hinders higher-order speech processing steps. The present findings, thus, strengthen proposals assuming that improper low-frequency acoustic entrainment affects speech sampling. This low speech-brain synchronization has the strong potential to cause severe consequences for both phonological and reading skills. Interestingly, the reduced speech-brain synchronization in dyslexic readers compared to normal readers (and its higher-order consequences across the speech processing network) appears preserved through the development from childhood to adulthood. Thus, the evaluation of speech-brain synchronization could possibly serve as a diagnostic tool for early detection of children at risk of dyslexia. Hum Brain Mapp 37:2767-2783, 2016. © 2016 Wiley Periodicals, Inc.

  19. Entrainment of circadian rhythm by ambient temperature cycles in mice.

    Science.gov (United States)

    Refinetti, Roberto

    2010-08-01

    Much is known about how environmental light-dark cycles synchronize circadian rhythms in animals. The ability of environmental cycles of ambient temperature to synchronize circadian rhythms has also been investigated extensively but mostly in ectotherms. In the present study, the synchronization of the circadian rhythm of running-wheel activity by environmental cycles of ambient temperature was studied in laboratory mice. Although all mice were successfully entrained by a light-dark cycle, only 60% to 80% of the mice were entrained by temperature cycles (24-32 degrees C or 24-12 degrees C), and attainment of stable entrainment seemed to take longer under temperature cycles than under a light-dark cycle. This suggests that ambient temperature cycles are weaker zeitgebers than light-dark cycles, which is consistent with the results of the few previous studies using mammalian species. Whereas 80% of the mice were entrained by 24-h temperature cycles, only 60% were entrained by 23-h cycles, and none was entrained by 25-h cycles. The results did not clarify whether entrainment by temperature cycles is caused directly by temperature or indirectly through a temperature effect on locomotor activity, but it is clear that the rhythm of running-wheel activity in mice can be entrained by ambient temperature cycles in the nonnoxious range.

  20. Effect of Air Entrainment on Breakup of Plunging Liquid Jet into Water Pool

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoungtak; Bang, Kwanghyun [Korea Maritime Univ., Busan (Korea, Republic of)

    2013-05-15

    The steam explosion intensity is largely dependent upon the degree of volumetric fractions of melt droplets and steam in the fuel-coolant mixture. The rate of melt jet breakup and droplet sizes are, therefore, the key physical parameters in the analysis of FCIs. In a recent OECD/NEA international program SERENA, the areas where research may be needed to reduce the level of uncertainties in the code predictions have been identified. The predicted void fractions in the mixture were generally much higher than experimental data and a deficiency in melt jet breakup modeling would be one of the primary causes. In this paper, an extended study of non-boiling liquid jet breakup from the previous jet breakup experiment is reported with an emphasis on the role of air entrainment by plunging liquid jet into water pool. An improved jet breakup model is also presented with comparison to the experimental data. Non-boiling liquid jet breakup experiment was conducted and the debris size was analyzed with a new jet breakup model with an emphasis on the role of air entrainment. The predicted debris size with consideration of entrained air showed good agreement with the experimental data.

  1. Macroscopic entrainment of periodically forced oscillatory ensembles.

    Science.gov (United States)

    Popovych, Oleksandr V; Tass, Peter A

    2011-03-01

    Large-amplitude oscillations of macroscopic neuronal signals, such as local field potentials and electroencephalography or magnetoencephalography signals, are commonly considered as being generated by a population of mutually synchronized neurons. In a computational study in generic networks of phase oscillators and bursting neurons, however, we show that this common belief may be wrong if the neuronal population receives an external rhythmic input. The latter may stem from another neuronal population or an external, e.g., sensory or electrical, source. In that case the population field potential may be entrained by the rhythmic input, whereas the individual neurons are phase desynchronized both mutually and with their field potential. Intriguingly, the corresponding large-amplitude oscillations of the population mean field are generated by pairwise desynchronized neurons oscillating at frequencies shifted far away from the frequency of the macroscopic field potential.

  2. Monitoring biodegradation of diesel fuel in bioventing processes using in situ respiration rate.

    Science.gov (United States)

    Lee, T H; Byun, I G; Kim, Y O; Hwang, I S; Park, T J

    2006-01-01

    An in situ measuring system of respiration rate was applied for monitoring biodegradation of diesel fuel in a bioventing process for bioremediation of diesel contaminated soil. Two laboratory-scale soil columns were packed with 5 kg of soil that was artificially contaminated by diesel fuel as final TPH (total petroleum hydrocarbon) concentration of 8,000 mg/kg soil. Nutrient was added to make a relative concentration of C:N:P = 100:10:1. One soil column was operated with continuous venting mode, and the other one with intermittent (6 h venting/6 h rest) venting mode. On-line O2 and CO2 gas measuring system was applied to measure O2 utilisation and CO2 production during biodegradation of diesel for 5 months. Biodegradation rate of TPH was calculated from respiration rate measured by the on-line gas measuring system. There were no apparent differences between calculated biodegradation rates from two columns with different venting modes. The variation of biodegradation rates corresponded well with trend of the remaining TPH concentrations comparing other biodegradation indicators, such as C17/pristane and C18/phytane ratio, dehydrogenase activity, and the ratio of hydrocarbon utilising bacteria to total heterotrophic bacteria. These results suggested that the on-line measuring system of respiration rate would be applied to monitoring biodegradation rate and to determine the potential applicability of bioventing process for bioremediation of oil contaminated soil.

  3. Extraordinary behavioral entrainment following circadian rhythm bifurcation in mice.

    Science.gov (United States)

    Harrison, Elizabeth M; Walbeek, Thijs J; Sun, Jonathan; Johnson, Jeremy; Poonawala, Qays; Gorman, Michael R

    2016-12-08

    The mammalian circadian timing system uses light to synchronize endogenously generated rhythms with the environmental day. Entrainment to schedules that deviate significantly from 24 h (T24) has been viewed as unlikely because the circadian pacemaker appears capable only of small, incremental responses to brief light exposures. Challenging this view, we demonstrate that simple manipulations of light alone induce extreme plasticity in the circadian system of mice. Firstly, exposure to dim nocturnal illumination (entrainment. Continuation of dim light is unnecessary for T15/30 behavioral entrainment following bifurcation. Finally, neither dim light alone nor a shortened night is sufficient for the extraordinary entrainment observed under bifurcation. Thus, we demonstrate in a non-pharmacological, non-genetic manipulation that the circadian system is far more flexible than previously thought. These findings challenge the current conception of entrainment and its underlying principles, and reveal new potential targets for circadian interventions.

  4. Freeze-casting as a Novel Manufacturing Process for Fast Reactor Fuels. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wegst, Ulrike G.K. [Dartmouth College, Hanover, NH (United States). Thayer School of Engineering; Allen, Todd [Idaho National Lab. (INL), Idaho Falls, ID (United States); Univ. of Wisconsin, Madison, WI (United States); Sridharan, Kumar [Idaho National Lab. (INL), Idaho Falls, ID (United States); Univ. of Wisconsin, Madison, WI (United States)

    2014-04-07

    Advanced burner reactors are designed to reduce the amount of long-lived radioactive isotopes that need to be disposed of as waste. The input feedstock for creating advanced fuel forms comes from either recycle of used light water reactor fuel or recycle of fuel from a fast burner reactor. Fuel for burner reactors requires novel fuel types based on new materials and designs that can achieve higher performance requirements (higher burn up, higher power, and greater margins to fuel melting) then yet achieved. One promising strategy to improved fuel performance is the manufacture of metal or ceramic scaffolds which are designed to allow for a well-defined placement of the fuel into the host, and this in a manner that permits greater control than that possible in the production of typical CERMET fuels.

  5. Stationary Liquid Fuel Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Won Sik [Purdue Univ., West Lafayette, IN (United States); Grandy, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Boroski, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Krajtl, Lubomir [Argonne National Lab. (ANL), Argonne, IL (United States); Johnson, Terry [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    For effective burning of hazardous transuranic (TRU) elements of used nuclear fuel, a transformational advanced reactor concept named SLFFR (Stationary Liquid Fuel Fast Reactor) was proposed based on stationary molten metallic fuel. The fuel enters the reactor vessel in a solid form, and then it is heated to molten temperature in a small melting heater. The fuel is contained within a closed, thick container with penetrating coolant channels, and thus it is not mixed with coolant nor flow through the primary heat transfer circuit. The makeup fuel is semi- continuously added to the system, and thus a very small excess reactivity is required. Gaseous fission products are also removed continuously, and a fraction of the fuel is periodically drawn off from the fuel container to a processing facility where non-gaseous mixed fission products and other impurities are removed and then the cleaned fuel is recycled into the fuel container. A reference core design and a preliminary plant system design of a 1000 MWt TRU- burning SLFFR concept were developed using TRU-Ce-Co fuel, Ta-10W fuel container, and sodium coolant. Conservative design approaches were adopted to stay within the current material performance database. Detailed neutronics and thermal-fluidic analyses were performed to develop a reference core design. Region-dependent 33-group cross sections were generated based on the ENDF/B-VII.0 data using the MC2-3 code. Core and fuel cycle analyses were performed in theta-r-z geometries using the DIF3D and REBUS-3 codes. Reactivity coefficients and kinetics parameters were calculated using the VARI3D perturbation theory code. Thermo-fluidic analyses were performed using the ANSYS FLUENT computational fluid dynamics (CFD) code. Figure 0.1 shows a schematic radial layout of the reference 1000 MWt SLFFR core, and Table 0.1 summarizes the main design parameters of SLFFR-1000 loop plant. The fuel container is a 2.5 cm thick cylinder with an inner radius of 87.5 cm. The fuel

  6. The site selection process for a spent fuel repository in Finland. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. [EnvirosQuantiSci (United Kingdom); Aeikaes, T. [Posiva Oy, Helsinki (Finland)

    2000-12-01

    This Summary Report describes the Finnish programme for the selection and characterisation of potential sites for the deep disposal of spent nuclear fuel and explains the process by which Olkiluoto has been selected as the single site proposed for the development of a spent fuel disposal facility. Its aim is to provide an overview of this process, initiated almost twenty years ago, which has entered its final phase. It provides information in three areas: a review of the early site selection criteria, a description of the site selection process, including all the associated site characterisation work, up to the point at which a single site was selected and an outline of the proposed work, in particular that proposed underground, to characterise further the Olkiluoto site. In 1983 the Finnish Government made a policy decision on the management of nuclear waste in which the main goals and milestones for the site selection programme for the deep disposal of spent fuel were presented. According to this decision several site candidates, whose selection was to be based on careful studies of the whole country, should be characterised and the site for the repository selected by the end of the year 2000. This report describes the process by which this policy decision has been achieved. The report begins with a discussion of the definition of the geological and environmental site selection criteria and how they were applied in order to select a small number of sites, five in all, that were to be the subject of the preliminary investigations. The methods used to investigate these sites and the results of these investigations are described, as is the evaluation of the results of these investigations and the process used to discard two of the sites and continue more detailed investigations at the remaining three. The detailed site investigations that commenced in 1993 are described with respect to the overall strategy followed and the investigation techniques applied. The

  7. Electrocatalytic processing of renewable biomass-derived compounds for production of chemicals, fuels and electricity

    Science.gov (United States)

    Xin, Le

    The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with renewable carbon from biomass as possible, innovative R&D activities must strive to enhance the current biorefinery process and secure our energy future. Much of my Ph.D. research effort is centered on the study of electrocatalytic conversion of biomass-derived compounds to produce value-added chemicals, biofuels and electrical energy on model electrocatalysts in AEM/PEM-based continuous flow electrolysis cell and fuel cell reactors. High electricity generation performance was obtained when glycerol or crude glycerol was employed as fuels in AEMFCs. The study on selective electrocatalytic oxidation of glycerol shows an electrode potential-regulated product distribution where tartronate and mesoxalate can be selectively produced with electrode potential switch. This finding then led to the development of AEMFCs with selective production of valuable tartronate or mesoxalate with high selectivity and yield and cogeneration of electricity. Reaction mechanisms of electrocatalytic oxidation of ethylene glycol and 1,2-propanediol were further elucidated by means of an on-line sample collection technique and DFT modeling. Besides electro-oxidation of biorenewable alcohols to chemicals and electricity, electrocatalytic reduction of keto acids (e.g. levulinic acid) was also studied for upgrading biomass-based feedstock to biofuels while

  8. An experimental and numerical analysis of the HCCI auto-ignition process of primary reference fuels, toluene reference fuels and diesel fuel in an engine, varying the engine parameters

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim; Cavadias, Simeon [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr-I' Ecole (France); Gilbert, Philippe [UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr-I' Ecole (France)

    2008-11-15

    For a future HCCI engine to operate under conditions that adhere to environmental restrictions, reducing fuel consumption and maintaining or increasing at the same time the engine efficiency, the choice of the fuel is crucial. For this purpose, this paper presents an auto-ignition investigation concerning the primary reference fuels, toluene reference fuels and diesel fuel, in order to study the effect of linear alkanes, branched alkanes and aromatics on the auto-ignition. The auto-ignition of these fuels has been studied at inlet temperatures from 25 to 120 C, at equivalence ratios from 0.18 to 0.53 and at compression ratios from 6 to 13.5, in order to extend the range of investigation and to assess the usability of these parameters to control the auto-ignition. It appeared that both iso-octane and toluene delayed the ignition with respect to n-heptane, while toluene has the strongest effect. This means that aromatics have higher inhibiting effects than branched alkanes. In an increasing order, the inlet temperature, equivalence ratio and compression ratio had a promoting effect on the ignition delays. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. (author)

  9. Integrated non-food concept of rape seed, reed canary grass and flax processing for fiber, fuel oil and solid fuel; Energiarypsi - peltojen non-food vaihtoehtoja

    Energy Technology Data Exchange (ETDEWEB)

    Sipilae, K. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1995-12-31

    The target of this project is to investigate if rape seed based fuel oil and diesel fuel component, agrofiber and solid fuel from other annual crops could be produced effectively as an alternative to existing non economical biodiesel-RME and ethanol production. Without heavy tax incentives the biodiesel and grain ethanol can not compete with conventional liquid fuels, the present EU fuel tax legislation will not permit any permanent tax incentives for commercial scale operations. Based on several studies by VTT the rape seed oil will be 30 % cheaper than RME and the utilization as a component 10-30 % blended to heating oil or diesel fuel might the most flexible solution. Neste Oy has carried out the combustion tests with 20 kW boiler and VTT the diesel engine tests with 20 % unprocessed rape seed oil mixtures, the oil was delivered by Mildola Oy. For the co-utilization of annual crops and straw, several laboratory scale combustion and flash pyrolysis tests have been carried out by VTT with straw, reed canary grass etc. In a flash pyrolysis process, the alkalies will remain in the char and a low alkali level bio oils can be produced. As a final step in order to reach the zero subsidy target, an extensive laboratory work is carried out to produce agrofibre from flax, reed canary grass and wheat straw. During the next months an overall economic calculations will be carried out in Finnish, Danish and Italian conditions as an EU-Apas project in order to see the competitiveness of such integrated concepts to conventional RME and reed canary grass combustion

  10. Comparative study of thermochemical processes for hydrogen production from biomass fuels.

    Science.gov (United States)

    Biagini, Enrico; Masoni, Lorenzo; Tognotti, Leonardo

    2010-08-01

    Different thermochemical configurations (gasification, combustion, electrolysis and syngas separation) are studied for producing hydrogen from biomass fuels. The aim is to provide data for the production unit and the following optimization of the "hydrogen chain" (from energy source selection to hydrogen utilization) in the frame of the Italian project "Filiera Idrogeno". The project focuses on a regional scale (Tuscany, Italy), renewable energies and automotive hydrogen. Decentred and small production plants are required to solve the logistic problems of biomass supply and meet the limited hydrogen infrastructures. Different options (gasification with air, oxygen or steam/oxygen mixtures, combustion, electrolysis) and conditions (varying the ratios of biomass and gas input) are studied by developing process models with uniform hypothesis to compare the results. Results obtained in this work concern the operating parameters, process efficiencies, material and energetic needs and are fundamental to optimize the entire hydrogen chain.

  11. Cu-Ni-YSZ anodes for solid oxide fuel cell by mechanical alloying processing

    Energy Technology Data Exchange (ETDEWEB)

    Guisard Restivo, Thomaz A.; Mello-Castanho, Sonia R.H. [IPEN, Inst. of Energetic and Nuclear Research, Sao Paulo, SP (Brazil)

    2010-01-15

    The work shows some results concerning a new cermet material 40 vol.% [(Cu)-Ni]-YSZ processed by mechanical alloying followed by Sintering by Activated Surface method. The projected cermet microstructure for this application is expected to possess microstructural characteristics that lead to better electric and ionic percolating, higher electrocatalytic activity and fuel reforming. The powder samples prepared by mechanical alloying optimized conditions show a homogeneous mixture. Transmission and scanning electron microscope analysis have demonstrated the powder particles are nanosized after 2 h of milling, showing lamellar internal structure aggregates. Suitable sintered pellets are obtained from these powders, within the required porosity and microstructure. Sintering kinetics studies for pellets of Ni-YSZ and Ni-Cu-YSZ indicate 2-step sintering processes. Copper additive promotes sintering and refines the microstructure. (orig.)

  12. Conceptual Process for the Manufacture of Low-Enriched Uranium/Molybdenum Fuel for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sease, J.D.; Primm, R.T. III; Miller, J.H.

    2007-09-30

    The U.S. nonproliferation policy 'to minimize, and to the extent possible, eliminate the use of HEU in civil nuclear programs throughout the world' has resulted in the conversion (or scheduled conversion) of many of the U.S. research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU). A foil fuel appears to offer the best option for using a LEU fuel in the High Flux Isotope Reactor (HFIR) without degrading the performance of the reactor. The purpose of this document is to outline a proposed conceptual fabrication process flow sheet for a new, foil-type, 19.75%-enriched fuel for HFIR. The preparation of the flow sheet allows a better understanding of the costs of infrastructure modifications, operating costs, and implementation schedule issues associated with the fabrication of LEU fuel for HFIR. Preparation of a reference flow sheet is one of the first planning steps needed in the development of a new manufacturing capacity for low enriched fuels for U.S. research and test reactors. The flow sheet can be used to develop a work breakdown structure (WBS), a critical path schedule, and identify development needs. The reference flow sheet presented in this report is specifically for production of LEU foil fuel for the HFIR. The need for an overall reference flow sheet for production of fuel for all High Performance Research Reactors (HPRR) has been identified by the national program office. This report could provide a starting point for the development of such a reference flow sheet for a foil-based fuel for all HPRRs. The reference flow sheet presented is based on processes currently being developed by the national program for the LEU foil fuel when available, processes used historically in the manufacture of other nuclear fuels and materials, and processes used in other manufacturing industries producing a product configuration similar to the form required in manufacturing a foil fuel. The processes in the reference flow sheet are

  13. Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO 2

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Duane D.; Siriwardane, Ranjani

    2013-08-15

    Chemical looping combustion (CLC) is a promising technology for fossil fuel combustion that produces sequestration-ready CO{sub 2} stream, reducing the energy penalty of CO{sub 2} separation from flue gases. An effective oxygen carrier for CLC will readily react with the fuel gas and will be reoxidized upon contact with oxygen. This study investigated the development of a CeO{sub 2}-promoted Fe{sub 2}O{sub 3}-hematite oxygen carrier suitable for the methane CLC process. Composition of CeO{sub 2} is between 5 and 25 wt % and is lower than what is generally used for supports in Fe{sub 2}O{sub 3} carrier preparations. The incorporation of CeO{sub 2} to the natural ore hematite strongly modifies the reduction behavior in comparison to that of CeO{sub 2} and hematite alone. Temperature-programmed reaction studies revealed that the addition of even 5 wt % CeO{sub 2} enhances the reaction capacity of the Fe{sub 2}O{sub 3} oxygen carrier by promoting the decomposition and partial oxidation of methane. Fixed-bed reactor data showed that the 5 wt % cerium oxides with 95 wt % iron oxide produce 2 times as much carbon dioxide in comparison to the sum of carbon dioxide produced when the oxides were tested separately. This effect is likely due to the reaction of CeO{sub 2} with methane forming intermediates, which are reactive for extracting oxygen from Fe{sub 2}O{sub 3} at a considerably faster rate than the rate of the direct reaction of Fe{sub 2}O{sub 3} with methane. These studies reveal that 5 wt % CeO{sub 2}/Fe{sub 2}O{sub 3} gives stable conversions over 15 reduction/oxidation cycles. Lab-scale reactor studies (pulsed mode) suggest the methane reacts initially with CeO{sub 2} lattice oxygen to form partial oxidation products (CO + H{sub 2}), which continue to react with oxygen from neighboring Fe{sub 2}O{sub 3}, leading to its complete oxidation to form CO{sub 2}. The reduced cerium oxide promotes the methane decomposition reaction to form C + H{sub 2}, which continue to

  14. Factors controlling the microstructure of Ce0.9Gd0.1O2-δ films in pulsed laser deposition process

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, S.; Döbeli, M.;

    Films of Ce0.9Gd0.1O2-δ(CGO10) are prepared at a range of conditions by pulsed laser deposition (PLD) on a single crystal Si (100) and MgO (100), and on a polycrystalline Pt/MgO (100) substrate. The relationship between the film microstructure, crystallography, chemical composition and PLD...

  15. Impacts and implementation of fuel moisture release and radiation properties in modelling of pulverized fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2015-01-01

    Pulverized fuels (PF) prepared and fired in utility boilers usually contain a certain amount of moisture, either free moisture or chemically bound moisture. In PF furnaces, radiation which is the principal mode of heat transfer consists of contribution from both gas and particle phase. This paper...... presents different methods for fuel moisture release and new models for gas and particle radiative properties, and demonstrates their implementation, importance and impacts in PF combustion modelling via a comprehensive CFD study of a pulverized coal-fired utility boiler. To conclude, it is recommended...... to add the free moisture into the primary air stream while lump the moisture retained in the feed after the mills with volatiles in PF combustion modelling. For gas and particle radiation in PF boilers, it is found that particle radiation largely overwhelms gas radiation due to high particle loading...

  16. Computational Study of Air Entrainment by Plunging Jets-Influence of Jet Inclination

    Science.gov (United States)

    Deshpande, Suraj; Trujillo, Mario

    2012-11-01

    The process of air entrainment by a continuous liquid jet plunging into a quiescent liquid pool is studied computationally. Our earlier study [APS2011] focused on shallow impacts and the discernible periodicity of air cavity formation. Here, we consider the effect of jet angle. For steep impacts, we see a chaotic formation of small cavities, in agreement with the literature. To explain the difference, we track evolution of the flow from initial impact to quasi-stationary state, for different jet inclinations. The initial impact always yields a large air cavity, regardless of jet angle. Difference emerges in the quasi-stationary state where shallow jets demonstrate the periodicity but the steep jets do not. We show that this is a manifestation of the air entrainment being a function of flow disturbance. For shallow jets, the disturbance originates from strong wavelike motion of the cavity which results in a total disruption of the jet. Thus, the resulting cavities are large and occur periodically. For the steep jets, entrainment happens by collapse of a thin gas film uniformly enshrouding the submerged jet. Such a thin film is very sensitive to the local flow disturbances. Thus, its collapse occurs stochastically all around the jet causing chaotic entrainment of small air pocket.

  17. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging.

    Science.gov (United States)

    Nozaradan, Sylvie

    2014-12-19

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain.

  18. Anodic Fenton process assisted by a microbial fuel cell for enhanced degradation of organic pollutants.

    Science.gov (United States)

    Liu, Xian-Wei; Sun, Xue-Fei; Li, Dao-Bo; Li, Wen-Wei; Huang, Yu-Xi; Sheng, Guo-Ping; Yu, Han-Qing

    2012-09-15

    The electro-Fenton process is efficient for degradation of organic pollutants, but it suffers from the high operating costs due to the need of power investment. Here, a new anodic Fenton system is developed for energy-saving and efficient treatment of organic pollutants by incorporating microbial fuel cell (MFC) into an anodic Fenton process. This system is composed of an anodic Fenton reactor and a two-chamber air-cathode MFC. The power generated from a two-chamber MFC is used to drive the anodic Fenton process for Acid Orange 7 (AO7) degradation through accelerating in situ generation of Fe(2+) from sacrificial iron. The kinetic results show that the MFC-assisted anodic Fenton process system had a significantly higher pseudo-first-order rate constant than those for the chemical Fenton methods. The electrochemical analysis reveals that AO7 did not hinder the corrosion of iron. The anodic Fenton process was influenced by the MFC performance. It was also found that increasing dissolved oxygen in the cathode improved the MFC power density, which in turn enhanced the AO7 degradation rate. These clearly demonstrate that the anodic Fenton process could be integrated with MFC to develop a self-sustained system for cost-effective and energy-saving electrochemical wastewater treatment.

  19. Combustion Characteristics of Chlorine-Free Solid Fuel Produced from Municipal Solid Waste by Hydrothermal Processing

    Directory of Open Access Journals (Sweden)

    Kunio Yoshikawa

    2012-11-01

    Full Text Available An experimental study on converting municipal solid waste (MSW into chlorine-free solid fuel using a combination of hydrothermal processing and water-washing has been performed. After the product was extracted from the reactor, water-washing experiments were then conducted to obtain chlorine-free products with less than 3000 ppm total chlorine content. A series of combustion experiments were then performed for the products before and after the washing process to determine the chlorine content in the exhaust gas and those left in the ash after the combustion process at a certain temperature. A series of thermogravimetric analyses were also conducted to compare the combustion characteristics of the products before and after the washing process. Due to the loss of ash and some volatile matter after washing process, there were increases in the fixed carbon content and the heating value of the product. Considering the possible chlorine emission, the washing process after the hydrothermal treatment should be necessary only if the furnace temperature is more than 800 °C.

  20. The in vitro real-time oscillation monitoring system identifies potential entrainment factors for circadian clocks

    Directory of Open Access Journals (Sweden)

    Yasuda Akio

    2006-02-01

    Full Text Available Abstract Background Circadian rhythms are endogenous, self-sustained oscillations with approximately 24-hr rhythmicity that are manifested in various physiological and metabolic processes. The circadian organization of these processes in mammals is governed by the master oscillator within the suprachiasmatic nuclei (SCN of the hypothalamus. Recent findings revealed that circadian oscillators exist in most organs, tissues, and even in immortalized cells, and that the oscillators in peripheral tissues are likely to be coordinated by SCN, the master oscillator. Some candidates for endogenous entrainment factors have sporadically been reported, however, their details remain mainly obscure. Results We developed the in vitro real-time oscillation monitoring system (IV-ROMS by measuring the activity of luciferase coupled to the oscillatory gene promoter using photomultiplier tubes and applied this system to screen and identify factors able to influence circadian rhythmicity. Using this IV-ROMS as the primary screening of entrainment factors for circadian clocks, we identified 12 candidates as the potential entrainment factor in a total of 299 peptides and bioactive lipids. Among them, four candidates (endothelin-1, all-trans retinoic acid, 9-cis retinoic acid, and 13-cis retinoic acid have already been reported as the entrainment factors in vivo and in vitro. We demonstrated that one of the novel candidates, 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2, a natural ligand of the peroxisome proliferator-activated receptor-γ (PPAR-γ, triggers the rhythmic expression of endogenous clock genes in NIH3T3 cells. Furthermore, we showed that 15d-PGJ2 transiently induces Cry1, Cry2, and Rorα mRNA expressions and that 15d-PGJ2-induced entrainment signaling pathway is PPAR-γ – and MAPKs (ERK, JNK, p38MAPK-independent. Conclusion Here, we identified 15d-PGJ2 as an entrainment factor in vitro. Using our developed IV-ROMS to screen 299 compounds, we found eight

  1. Gasification of biomass wastes in an entrained flow gasifier: Effect of the particle size and the residence time

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Juan J.; Aranda-Almansa, Guadalupe [Universidad de Castilla-La Mancha, Departamento de Mecanica Aplicada e Ingenieria de Proyectos, Escuela Tecnica Superior de Ingenieros Industriales (Edificio Politecnico), Avenida Camilo Jose Cela s/n, 13071 Ciudad Real (Spain); Bula, Antonio [Universidad del Norte, Departamento de Ingenieria Mecanica, Km.5 Antigua Via Puerto Colombia, Barranquilla (Colombia)

    2010-06-15

    Experimental tests in an entrained flow gasifier have been carried out in order to evaluate the effect of the biomass particle size and the space residence time on the gasifier performance and the producer gas quality. Three types of biomass fuels (grapevine pruning and sawdust wastes, and marc of grape) and a fossil fuel (a coal-coke blend) have been tested. The results obtained show that a reduction in the fuel particle size leads to a significant improvement in the gasification parameters. The thermochemical characterisation of the resulting char-ash residue shows a sharp increase in the fuel conversion for particles below 1 mm diameter, which could be adequate to be used in conventional entrained flow gasifiers. Significant differences in the thermochemical behaviour of the biomass fuels and the coal-coke blend have been found, especially in the evolution of the H{sub 2}/CO ratio with the space time, mainly due to the catalytic effect of the coal-coke ash. The reaction temperature and the space time have a significant effect on the H{sub 2}/CO ratio (the relative importance of each of these parameters depending on the temperature), this value being independent of the fuel particle size. (author)

  2. Comparative Study of Laboratory-Scale and Prototypic Production-Scale Fuel Fabrication Processes and Product Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Douglas W. Marshall

    2014-10-01

    An objective of the High Temperature Gas Reactor fuel development and qualification program for the United States Department of Energy has been to qualify fuel fabricated in prototypic production-scale equipment. The quality and characteristics of the tristructural isotropic coatings on fuel kernels are influenced by the equipment scale and processing parameters. Some characteristics affecting product quality were suppressed while others have become more significant in the larger equipment. Changes to the composition and method of producing resinated graphite matrix material has eliminated the use of hazardous, flammable liquids and enabled it to be procured as a vendor-supplied feed stock. A new method of overcoating TRISO particles with the resinated graphite matrix eliminates the use of hazardous, flammable liquids, produces highly spherical particles with a narrow size distribution, and attains product yields in excess of 99%. Compact fabrication processes have been scaled-up and automated with relatively minor changes to compact quality to manual laboratory-scale processes. The impact on statistical variability of the processes and the products as equipment was scaled are discussed. The prototypic production-scale processes produce test fuels that meet fuel quality specifications.

  3. Initial evaluation of dry storage issues for spent nuclear fuels in wet storage at the Idaho Chemical Processing Plant

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, R J; Johnson, Jr, A B; Lund, A L; Gilbert, E R [and others

    1996-07-01

    The Pacific Northwest Laboratory has evaluated the basis for moving selected spent nuclear fuels in the CPP-603 and CPP-666 storage pools at the Idaho Chemical Processing Plant from wet to dry interim storage. This work is being conducted for the Lockheed Idaho Technologies Company as part of the effort to determine appropriate conditioning and dry storage requirements for these fuels. These spent fuels are from 22 test reactors and include elements clad with aluminum or stainless steel and a wide variety of fuel materials: UAl{sub x}, UAl{sub x}-Al and U{sub 3}O{sub 8}-Al cermets, U-5% fissium, UMo, UZrH{sub x}, UErZrH, UO{sub 2}-stainless steel cermet, and U{sub 3}O{sub 8}-stainless steel cermet. The study also included declad uranium-zirconium hydride spent fuel stored in the CPP-603 storage pools. The current condition and potential failure mechanisms for these spent fuels were evaluated to determine the impact on conditioning and dry storage requirements. Initial recommendations for conditioning and dry storage requirements are made based on the potential degradation mechanisms and their impacts on moving the spent fuel from wet to dry storage. Areas needing further evaluation are identified.

  4. 327 SNF fuel return to K-Basin quality process plan

    Energy Technology Data Exchange (ETDEWEB)

    Ham, J.E.

    1998-09-22

    The B and W Hanford Company`s (BWHC) 327 Facility, in the 300 Area of the Hanford Site, contains Spent Nuclear Fuel (SNF) single fuel element canisters (SFEC) and fuel remnant canisters (FRC) which are to be returned to K-Basin. Seven shipments of up to six fuel canisters will be loaded into the CNS 1-13G Cask and transported to 105-KE.

  5. Waste plastics as supplemental fuel in the blast furnace process: improving combustion efficiencies.

    Science.gov (United States)

    Kim, Dongsu; Shin, Sunghye; Sohn, Seungman; Choi, Jinshik; Ban, Bongchan

    2002-10-14

    The possibility of using waste plastics as a source of secondary fuel in a blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. For instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in a blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with a decrease in particle size, the combustibility of waste polyethylene could be improved at a given distance from the tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at a longer distance from the tuyere.

  6. Bioelectricity generation using two chamber microbial fuel cell treating wastewater from food processing.

    Science.gov (United States)

    Mansoorian, Hossein Jafari; Mahvi, Amir Hossein; Jafari, Ahmad Jonidi; Amin, Mohammad Mehdi; Rajabizadeh, Ahmad; Khanjani, Narges

    2013-05-10

    Electricity generation from microbial fuel cells which treat food processing wastewater was investigated in this study. Anaerobic anode and aerobic cathode chambers were separated by a proton exchange membrane in a two-compartment MFC reactor. Buffer solutions and food industry wastewater were used as electrolytes in the anode and cathode chambers, respectively. The produced voltage and current intensity were measured using a digital multimeter. Effluents from the anode compartment were tested for COD, BOD5, NH3, P, TSS, VSS, SO4 and alkalinity. The maximum current density and power production were measured 527mA/m(2) and 230mW/m(2) in the anode area, respectively, at operation organic loading (OLR) of 0.364g COD/l.d. At OLR of 0.182g COD/l.d, maximum voltage and columbic efficiency production were recorded 0.475V and 21%, respectively. Maximum removal efficiency of COD, BOD5, NH3, P, TSS, VSS, SO4 and alkalinity were 86, 79, 73, 18, 68, 62, 30 and 58%, respectively. The results indicated that catalysts and mediator-less microbial fuel cells (CAML-MFC) can be considered as a better choice for simple and complete energy conversion from the wastewater of such industries and also this could be considered as a new method to offset wastewater treatment plant operating costs.

  7. Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (Phb) from a Process Relevant Lignocellulosic Derived Sugar

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Mohagheghi, Ali; Mittal, Ashutosh; Pilath, Heidi; Johnson, David K.

    2015-03-22

    PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. In recent years a great effort has been made in bacterial production of PHB, yet the production cost of the polymer is still much higher than conventional petrochemical plastics. The high cost of PHB is because the cost of the substrates can account for as much as half of the total product cost in large scale fermentation. Thus searching for cheaper and better substrates is very necessary for PHB production. In this study, we demonstrate production of PHB by Cupriavidus necator from a process relevant lignocellulosic derived sugar stream, i.e., saccharified hydrolysate slurry from pretreated corn stover. Good cell growth was observed on slurry saccharified with advanced enzymes and 40~60% of PHB was accumulated in the cells. The mechanism of inhibition in the toxic hydrolysate generated by pretreatment and saccharification of biomass, will be discussed.

  8. Development of OTM Syngas Process and Testing of Syngas Derived Ulta-clean Fuels in Diesel Engines and Fuel Cells Budget Period 3

    Energy Technology Data Exchange (ETDEWEB)

    E.T. Robinson; John Sirman; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Dan Corgard; Siv Aasland; Kjersti Kleveland; Ann Hooper; Leo Bonnell; John Hemmings; Jack Chen; Bart A. Van Hassel

    2004-12-31

    This topical report summarizes work accomplished for the Program from January 1, 2003 through December 31,2004 in the following task areas: Task 1--Materials Development; Task 2--Composite Development; Task 4--Reactor Design and Process Optimization; Task 8--Fuels and Engine Testing; 8.1 International Diesel Engine Program; and Task IO: Program Management. Most of the key technical objectives for this budget period were achieved. Only partial success was achieved relative to cycle testing under pressure Major improvements in material performance and element reliability have been achieved. A breakthrough material system has driven the development of a compact planar reactor design capable of producing either hydrogen or syngas. The planar reactor shows significant advantages in thermal efficiency and costs compared to either steam methane reforming with CO{sub 2} recovery or autothermal reforming. The fuel and engine testing program is complete The single cylinder test engine evaluation of UCTF fuels begun in Budget Period 2 was finished this budget period. In addition, a study to evaluate new fuel formulations for an HCCl engine was completed.

  9. Basic research on separation control of long life nuclides in fuel reprocessing processes

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsuyuki; Usami, Go [Tokyo Univ. (Japan). Faculty of Engineering; Maeda, Mitsuru; Fujine, Sachio; Uchiyama, Gunzo; Kihara, Takehiro; Asakura, Toshihide; Hotoku, Shinobu

    1996-01-01

    The behavior of technetium (Tc) in nuclear fuel reprocessing processes has become the subject to be elucidated in the transition to distribution process by coextraction and the catalytic action in distribution process. In order to forecast or control the behavior of Tc in reprocessing processes, it is necessary to understand that at which valence Tc exists stably in respective processes. Tc is stable at 7 valence in nitric acid solution expected in reprocessing. In this research, the reaction speed of the oxidation and reduction reactions of rhenium (Re) which simulates Tc was measured by laser Raman spectroscopy which can do high speed analysis of valence. The experimental method is explained. The Raman spectra of Re in the experimental system of this research were measured in perchloric acid solution and nitric acid solution, and compared with the values in literatures. As the result, the validity of this research was assured. It was confirmed that Re(7) was not reduced by sulfamic acid and ascorbic acid. Re(7) was reduced by thiocyanic acid once, but was oxidized again by the reaction of thiocyanic acid and nitric acid. (K.I.)

  10. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Features, events and processes 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Features, Events and Processes sits within Posiva Oy's Safety Case 'TURVA-2012' portfolio and has the objective of presenting the main features, events and processes (FEPs) that are considered to be potentially significant for the long-term safety of the planned KBS-3V repository for spent nuclear fuel at Olkiluoto. The primary purpose of this report is to support Performance Assessment, Formulation of Radionuclide Release Scenarios, Assessment of the Radionuclide Release Scenarios for the Repository System and Biosphere Assessment by ensuring that the scenarios are comprehensive and take account of all significant FEPs. The main FEPs potentially affecting the disposal system are described for each relevant subsystem component or barrier (i.e. the spent nuclear fuel, the canister, the buffer and tunnel backfill, the auxiliary components, the geosphere and the surface environment). In addition, a small number of external FEPs that may potentially influence the evolution of the disposal system are described. The conceptual understanding and operation of each FEP is described, together with the main features (variables) of the disposal system that may affect its occurrence or significance. Olkiluoto-specific issues are considered when relevant. The main uncertainties (conceptual and parameter/data) associated with each FEP that may affect understanding are also documented. Indicative parameter values are provided, in some cases, to illustrate the magnitude or rate of a process, but it is not the intention of this report to provide the complete set of numerical values that are used in the quantitative safety assessment calculations. Many of the FEPs are interdependent and, therefore, the descriptions also identify the most important direct couplings between the FEPs. This information is used in the formulation of scenarios to ensure the conceptual models and calculational cases are both comprehensive and representative. (orig.)

  11. Estimation of the Waste Mass from a Pyro-Process of Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Soo; Choi, Jong Won; Choi, Heui Joo (and others)

    2008-04-15

    Pyro-Process is now developing to retrieve reusable uranium and TRU, and to reduce the volume of high level waste from a nuclear power plant. In this situation, it is strongly required for the estimation of expected masses and their physical properties of the wastes. In this report, the amount of wastes and their physical properties are presupposed through some assumptions in regard to 10MTHM of Oxide Fuel with 4.5wt% U-235, 45,000 MWD/MTU, and 5yrs cooling. The produced wastes can be divided into three categories such as metal, CWF(Ceramic Waste Form), and VWF(Vitrified Waste Form). The 42 nuclrides in a spent nuclear fuel are distributed into the waste categories on the their physical and thermodynamic properties when they exist in metal, oxide, or chloride forms. The treated atomic groups are Uranium, TRU, Noble metal, Rare earth, Alkali metal, Halogens, and others. The mass of each waste is estimated by the distribution results. The off-gas waste is included into a CWF. The heat generations by the wastes in this Pyro-Process are calculated using a ORIGEN-ARP program. It is possible to estimate the amounts of wastes and their heat generation rates in this Pyro-Process analysis. These information are very helpful to design a waste container and its quantity also can be determined. The number of container and its heat generation rate will be key factor for the construction of interim storage facilities including a underground disposal site.

  12. Overall Energy Considerations for Algae Species Comparison and Selection in Algae-to-Fuels Processes

    Energy Technology Data Exchange (ETDEWEB)

    Link, D.; Kail, B.; Curtis, W.; Tuerk,A.

    2011-01-01

    species in the same photobioreactor system should be similar at light limited growth conditions based on photon flux. It is how the algae 'allocate' this energy captured that will vary: Data will be presented that shows that Botryococcus invests greater energy in oil production than Chlorella under these growth conditions. In essence, the Chlorella can grow 'fast and lean' or can be slowed to grow 'slow and fat'. The overall energy potential between the Chlorella and Botryococcus, then, becomes much more equivalent on a per-photon basis. This work will indicate an interesting relationship between two very different algae species, in terms of growth rate, lipid content and composition, and energy efficiency of the overall process. The presentation will indicate that in light-limited growth, it cannot be assumed that either rapid growth rate or lipid production rate can be used as stand-alone indicators of which species-lipid relationships will truly be more effective in algae-to-fuels scenarios.

  13. 固体电解质BaCe1-xREXO3-δ的电导率及燃料电池性能%Structure and properties of the fuel cell of BaCe1-xRExO3-δ

    Institute of Scientific and Technical Information of China (English)

    陶宁; 蒋凯

    2001-01-01

    利用溶胶-凝胶法合成了BaCe1-xRExO3 (RE:稀土)系列固体电解质,结果证明纯BaCeO3导电性较差,RE3+的引入,取代了晶格中的Ce4+,增加了氧空位,大大提高了体系的导电性.文章还研究了掺杂的BaCeO3体系的导电机理,讨论了不同稀土离子掺杂对电导率的影响,以BaCe1-xRExOa-δ为固体电解质组装了H2/O2燃料电池,电池的开路电压接近1 V,短路电流密度超过100 mA/cm2,以BaCeo.8Cdo.2O2.9为SOFC电解质,800℃时最大输出功率密度达30 mW/cm2.

  14. CO{sub 2} separation by calcium looping from full and partial fuel oxidation processes

    Energy Technology Data Exchange (ETDEWEB)

    Sivalingam, Senthoorselvan

    2013-06-05

    This thesis work deals with the research and development of calcium looping process for CO{sub 2} separation from full and partial fuel oxidation based power generation systems. CO{sub 2} is the main greenhouse gas and undoubtedly a major contributor to the global warming. It is estimated that more than one third of the total anthropogenic CO{sub 2} emissions come from fossil fuel based heat and power generation. Moreover, fossil fuels are unlikely to be phased out rapidly, since developing alternative energy sources not only take time but also require huge investments and infrastructure. An alternative way to reduce emissions in a medium term is to capture the CO{sub 2} from fossil fueled power plants and store it away from the atmosphere. This process system combining a bunch of technologies is called carbon capture and storage (CCS). CO{sub 2} capture is an important and costly part of CCS and an array of technologies is considered for this. Calcium looping (CaL) is one of such and seems to offer effective and efficient CO{sub 2} separation from fuel oxidation processes. CaL process involves separation of CO{sub 2} at high temperatures (600-700 C) by calcium sorbents (CaO). CO{sub 2} reacts with CaO in a carbonation process and produces CaCO{sub 3}. In a subsequent thermal regeneration (>850 C) called calcination, the CO{sub 2} is released from CaCO{sub 3}. By alternating carbonations and calcinations over multiple cycles, CO{sub 2} is separated from a gas stream. Moreover, the CaL is realised in industrial scale with dual fluidised bed reactors for CO{sub 2} capture (the carbonator) and sorbent regeneration (the calciner). As a process in the development, research is still required in many aspects from thermodynamic modeling to experimental studies. Research works have been carried out in process simulations, sorbent reactivity and optimisation studies in a controlled reactor environment and process parametric studies in a semi-pilot scale CaL test facility

  15. Entrainment of the mammalian cell cycle by the circadian clock: modeling two coupled cellular rhythms.

    Science.gov (United States)

    Gérard, Claude; Goldbeter, Albert

    2012-05-01

    The cell division cycle and the circadian clock represent two major cellular rhythms. These two periodic processes are coupled in multiple ways, given that several molecular components of the cell cycle network are controlled in a circadian manner. For example, in the network of cyclin-dependent kinases (Cdks) that governs progression along the successive phases of the cell cycle, the synthesis of the kinase Wee1, which inhibits the G2/M transition, is enhanced by the complex CLOCK-BMAL1 that plays a central role in the circadian clock network. Another component of the latter network, REV-ERBα, inhibits the synthesis of the Cdk inhibitor p21. Moreover, the synthesis of the oncogene c-Myc, which promotes G1 cyclin synthesis, is repressed by CLOCK-BMAL1. Using detailed computational models for the two networks we investigate the conditions in which the mammalian cell cycle can be entrained by the circadian clock. We show that the cell cycle can be brought to oscillate at a period of 24 h or 48 h when its autonomous period prior to coupling is in an appropriate range. The model indicates that the combination of multiple modes of coupling does not necessarily facilitate entrainment of the cell cycle by the circadian clock. Entrainment can also occur as a result of circadian variations in the level of a growth factor controlling entry into G1. Outside the range of entrainment, the coupling to the circadian clock may lead to disconnected oscillations in the cell cycle and the circadian system, or to complex oscillatory dynamics of the cell cycle in the form of endoreplication, complex periodic oscillations or chaos. The model predicts that the transition from entrainment to 24 h or 48 h might occur when the strength of coupling to the circadian clock or the level of growth factor decrease below critical values.

  16. Converting oil shale to liquid fuels: energy inputs and greenhouse gas emissions of the Shell in situ conversion process.

    Science.gov (United States)

    Brandt, Adam R

    2008-10-01

    Oil shale is a sedimentary rock that contains kerogen, a fossil organic material. Kerogen can be heated to produce oil and gas (retorted). This has traditionally been a CO2-intensive process. In this paper, the Shell in situ conversion process (ICP), which is a novel method of retorting oil shale in place, is analyzed. The ICP utilizes electricity to heat the underground shale over a period of 2 years. Hydrocarbons are produced using conventional oil production techniques, leaving shale oil coke within the formation. The energy inputs and outputs from the ICP, as applied to oil shales of the Green River formation, are modeled. Using these energy inputs, the greenhouse gas (GHG) emissions from the ICP are calculated and are compared to emissions from conventional petroleum. Energy outputs (as refined liquid fuel) are 1.2-1.6 times greater than the total primary energy inputs to the process. In the absence of capturing CO2 generated from electricity produced to fuel the process, well-to-pump GHG emissions are in the range of 30.6-37.1 grams of carbon equivalent per megajoule of liquid fuel produced. These full-fuel-cycle emissions are 21%-47% larger than those from conventionally produced petroleum-based fuels.

  17. Process for producing biodiesel, lubricants, and fuel and lubricant additives in a critical fluid medium

    Science.gov (United States)

    Ginosar, Daniel M.; Fox, Robert V.

    2005-05-03

    A process for producing alkyl esters useful in biofuels and lubricants by transesterifying glyceride- or esterifying free fatty acid-containing substances in a single critical phase medium is disclosed. The critical phase medium provides increased reaction rates, decreases the loss of catalyst or catalyst activity and improves the overall yield of desired product. The process involves the steps of dissolving an input glyceride- or free fatty acid-containing substance with an alcohol or water into a critical fluid medium; reacting the glyceride- or free fatty acid-containing substance with the alcohol or water input over either a solid or liquid acidic or basic catalyst and sequentially separating the products from each other and from the critical fluid medium, which critical fluid medium can then be recycled back in the process. The process significantly reduces the cost of producing additives or alternatives to automotive fuels and lubricants utilizing inexpensive glyceride- or free fatty acid-containing substances, such as animal fats, vegetable oils, rendered fats, and restaurant grease.

  18. Producing fuel alcohol by extractive distillation: Simulating the process with glycerol

    Directory of Open Access Journals (Sweden)

    Ana María Uyazán

    2010-07-01

    Full Text Available Downstream separation processes in biotechnology form part of the stages having most impact on a product’s final cost. The tendency throughout the world today is to replace fossil fuels with those having a renewable origin such as ethanol; this, in turn, produces a demand for the same and the need for optimising fermentation, treating vinazas and dehydration processes. The present work approaches the problem of dehydration through simulating azeotropic ethanol extractive distillation using glycerol as separation agent. Simulations were done on an Aspen Plus process simulator (Aspen Tech version 11.1. The simulated process involves two distillation columns, a dehydrator and a glycerol recuperation column. Simulation restrictions were ethanol’s molar composition in dehydrator column distillate and the process’s energy consumption. The effect of molar reflux ratio, solvent-feed ratio, solvent entry and feed stage and solvent entry temperature were evaluated on the chosen restrictions. The results showed that the ethanol-water mixture dehydration with glycerol as separation agent is efficient from the energy point of view.

  19. Heterogeneous catalytic process for alcohol fuels from syngas. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Dombek, B.D.

    1996-03-01

    The primary objective of this project has been the pursuit of a catalyst system which would allow the selective production from syngas of methanol and isobutanol. It is desirable to develop a process in which the methanol to isobutanol weight ratio could be varied from 70/30 to 30/70. The 70/30 mixture could be used directly as a fuel additive, while, with the appropriate downstream processing, the 30/70 mixture could be utilized for methyl tertiary-butyl ether (MTBE) synthesis. The indirect manufacture of MTBE from a coal derived syngas to methanol and isobutanol process would appear to be a viable solution to MTBE feedstock limitations. To become economically attractive, a process fro producing oxygenates from coal-derived syngas must form these products with high selectivity and good rates, and must be capable of operating with a low-hydrogen-content syngas. This was to be accomplished through extensions of known catalyst systems and by the rational design of novel catalyst systems.

  20. Biocatalytic production of biodiesel from cottonseed oil: Standardization of process parameters and comparison of fuel characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, Soham; Karemore, Ankush; Das, Sancharini; Sen, Ramkrishna [Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Deysarkar, Asoke [PfP Technology LLC., 14227 Fern, Houston, TX 77079 (United States)

    2011-04-15

    The enzymatic production of biodiesel by transesterification of cottonseed oil was studied using low cost crude pancreatic lipase as catalyst in a batch system. The effects of the critical process parameters including water percentage, methanol:oil ratio, enzyme concentration, buffer pH and reaction temperature were determined. Maximum conversion of 75-80% was achieved after 4 h at 37 C, pH 7.0 and with 1:15 M ratio of oil to methanol, 0.5% (wt of oil) enzyme and water concentration of 5% (wt of oil). Various organic solvents were tested among which a partially polar solvent (t-butanol) was found to be suitable for the reaction. The major fuel characteristics like specific gravity, kinematic viscosity, flash point and calorific value of the 20:80 blends (B20) of the fatty acid methyl esters with petroleum diesel conformed very closely to those of American Society for Testing Materials (ASTM) standards. (author)

  1. Development of Head-end Pyrochemical Reduction Process for Advanced Oxide Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Park, B. H.; Seo, C. S.; Hur, J. M.; Jeong, S. M.; Hong, S. S.; Choi, I. K.; Choung, W. M.; Kwon, K. C.; Lee, I. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-12-15

    The development of an electrolytic reduction technology for spent fuels in the form of oxide is of essence to introduce LWR SFs to a pyroprocessing. In this research, the technology was investigated to scale a reactor up, the electrochemical behaviors of FPs were studied to understand the process and a reaction rate data by using U{sub 3}O{sub 8} was obtained with a bench scale reactor. In a scale of 20 kgHM/batch reactor, U{sub 3}O{sub 8} and Simfuel were successfully reduced into metals. Electrochemical characteristics of LiBr, LiI and Li{sub 2}Se were measured in a bench scale reactor and an electrolytic reduction cell was modeled by a computational tool.

  2. Investigation of Micro- and Macro-Scale Transport Processes for Improved Fuel Cell Performance

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Wenbin [General Motors LLC, Pontiac, MI (United States)

    2014-08-29

    This report documents the work performed by General Motors (GM) under the Cooperative agreement No. DE-EE0000470, “Investigation of Micro- and Macro-Scale Transport Processes for Improved Fuel Cell Performance,” in collaboration with the Penn State University (PSU), University of Tennessee Knoxville (UTK), Rochester Institute of Technology (RIT), and University of Rochester (UR) via subcontracts. The overall objectives of the project are to investigate and synthesize fundamental understanding of transport phenomena at both the macro- and micro-scales for the development of a down-the-channel model that accounts for all transport domains in a broad operating space. GM as a prime contractor focused on cell level experiments and modeling, and the Universities as subcontractors worked toward fundamental understanding of each component and associated interface.

  3. Production of small uranium dioxide microspheres for cermet nuclear fuel using the internal gelation process

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Robert T [ORNL; Collins, Jack Lee [ORNL; Hunt, Rodney Dale [ORNL; Ladd-Lively, Jennifer L [ORNL; Patton, Kaara K [ORNL; Hickman, Robert [NASA Marshall Space Flight Center, Huntsville, AL

    2014-01-01

    The U.S. National Aeronautics and Space Administration (NASA) is developing a uranium dioxide (UO2)/tungsten cermet fuel for potential use as the nuclear cryogenic propulsion stage (NCPS). The first generation NCPS is expected to be made from dense UO2 microspheres with diameters between 75 and 150 m. Previously, the internal gelation process and a hood-scale apparatus with a vibrating nozzle were used to form gel spheres, which became UO2 kernels with diameters between 350 and 850 m. For the NASA spheres, the vibrating nozzle was replaced with a custom designed, two-fluid nozzle to produce gel spheres in the desired smaller size range. This paper describes the operational methodology used to make 3 kg of uranium oxide microspheres.

  4. Aerodynamic Study on Supersonic Flows in High-Velocity Oxy-Fuel Thermal Spray Process

    Institute of Scientific and Technical Information of China (English)

    Hiroshi KATANODA; Takeshi MATSUOKA; Seiji KURODA; Jin KAWAKITA; Hirotaka FUKANUMA; Kazuyasu MATSUO

    2005-01-01

    @@ To clarify the characteristics of gas flow in high velocity oxy-fuel (HVOF) thermal spray gun, aerodynamic research is performed using a special gun. The gun has rectangular cross-sectional area and sidewalls of optical glass to visualize the internal flow. The gun consists of a supersonic nozzle with the design Mach number of 2.0 followed by a straight passage called barrel. Compressed dry air up to 0.78 MPa is used as a process gas instead of combustion gas which is used in a commercial HVOF gun. The high-speed gas flows with shock waves in the gun and jets are visualized by schlieren technique. Complicated internal and external flow-fields containing various types of shock wave as well as expansion wave are visualized.

  5. Quantitative spray analysis of diesel fuel and its emulsions using digital image processing

    Directory of Open Access Journals (Sweden)

    Faik Ahmad Muneer El-Deen

    2015-01-01

    Full Text Available In the present work, an experimental investigation of spray atomization of different liquids has been carried out. An air-assist atomizer operating at low injection pressures value