Sample records for topics catalysis homogeneous

  1. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    SciTech Connect (OSTI)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01T23:59:59.000Z

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  2. Topics in Catalysis ISSN 1022-5528

    E-Print Network [OSTI]

    Frenkel, Anatoly

    1 23 Topics in Catalysis ISSN 1022-5528 Top Catal DOI 10.1007/s11244-013-0053-y Characterization ubiquitous catalytic systems commonly used [1­6]. Despite significant progress made in developing catalysis, the challenge remains in the co-interpretation of their results since these methods are commonly applied

  3. Homogeneous Catalysis Selective Oxidation of Methane to Methanol

    E-Print Network [OSTI]

    Goddard III, William A.

    Homogeneous Catalysis Selective Oxidation of Methane to Methanol Catalyzed, with CÀH Activation (generated by dissolution[6] of Au2O3) react with methane at 1808C to selectively generate methanol (as a mixture of the ester and methanol) in high yield (Table 1, entries 1 and 2). As expected, the irreversible

  4. Converting Homogeneous to Heterogeneous in Electrophilic Catalysis using Monodisperse Metal Nanoparticles

    SciTech Connect (OSTI)

    Witham, Cole A.; Huang, Wenyu; Tsung, Chia-Kuang; Kuhn, John N.; Somorjai, Gabor A.; Toste, F. Dean

    2009-10-15T23:59:59.000Z

    A continuing goal in catalysis is the transformation of processes from homogeneous to heterogeneous. To this end, nanoparticles represent a new frontier in heterogeneous catalysis, where this conversion is supplemented by the ability to obtain new or divergent reactivity and selectivity. We report a novel method for applying heterogeneous catalysts to known homogeneous catalytic reactions through the design and synthesis of electrophilic platinum nanoparticles. These nanoparticles are selectively oxidized by the hypervalent iodine species PhICl{sub 2}, and catalyze a range of {pi}-bond activation reactions previously only homogeneously catalyzed. Multiple experimental methods are utilized to unambiguously verify the heterogeneity of the catalytic process. The discovery of treatments for nanoparticles that induce the desired homogeneous catalytic activity should lead to the further development of reactions previously inaccessible in heterogeneous catalysis. Furthermore, our size and capping agent study revealed that Pt PAMAM dendrimer-capped nanoparticles demonstrate superior activity and recyclability compared to larger, polymer-capped analogues.

  5. asymmetric catalysis stereoelectronic: Topics by E-print Network

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

    X Lewis Acid Catalysis Brnsted Acid Catalysis X Johnson, Jeff S. 2 Multidimensional free energy relationships in asymmetric catalysis. Open Access Theses and Dissertations...

  6. ISHHC XIII International Symposium on the Relations betweenHomogeneous and Heterogeneous Catalysis

    SciTech Connect (OSTI)

    Somorjai (Ed.), G.A.

    2007-06-11T23:59:59.000Z

    The International Symposium on Relations between Homogeneous and Heterogeneous Catalysis (ISHHC) has a long and distinguished history. Since 1974, in Brussels, this event has been held in Lyon, France (1977), Groeningen, The Netherlands (1981); Asilomar, California (1983); Novosibirsk, Russia (1986); Pisa, Italy (1989); Tokyo, Japan (1992); Balatonfuered, Hungary (1995); Southampton, United Kingdom (1999); Lyon, France (2001); Evanston, Illinois (2001) and Florence, Italy (2005). The aim of this international conference in Berkeley is to bring together practitioners in the three fields of catalysis, heterogeneous, homogeneous and enzyme, which utilize mostly nanosize particles. Recent advances in instrumentation, synthesis and reaction studies permit the nanoscale characterization of the catalyst systems, often for the same reaction, under similar experimental conditions. It is hoped that this circumstance will permit the development of correlations of these three different fields of catalysis on the molecular level. To further this goal we aim to uncover and focus on common concepts that emerge from nanoscale studies of structures and dynamics of the three types of catalysts. Another area of focus that will be addressed is the impact on and correlation of nanosciences with catalysis. There is information on the electronic and atomic structures of nanoparticles and their dynamics that should have importance in catalyst design and catalytic activity and selectivity.

  7. Catalysis of Protein Disulfide Bond Isomerization in a Homogeneous Substrate Elizabeth A. Kersteen,, Seth R. Barrows, and Ronald T. Raines*,,|

    E-Print Network [OSTI]

    Raines, Ronald T.

    Catalysis of Protein Disulfide Bond Isomerization in a Homogeneous Substrate Elizabeth A. Kersteen in these assays are, however, heterogeneous, which complicates mechanistic analyses. Here, we report the first use this continuous assay to analyze catalysis by wild-type human PDI and a variant in which the C

  8. HOMOGENEOUS CATALYSIS AND MASS TRANSFER IN BIPHASIC IONIC LIQUID SYSTEMS WITH COMPRESSED CO2 AND ORGANIC COMPOUNDS

    E-Print Network [OSTI]

    Ahosseini, Azita

    ABSTRACT Homogeneous catalysis in which the catalyst, solvents and reactants are all in the same phase can yield high activity and selectivity and efficiently produce chemical products. However, the main problem with these ...

  9. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    Catalytic Processes Applied Catalysis A: General 221 (2001)Kamp, J.J.F. Scholten Applied Catalysis A. : General 89 (77. S. Xie, M. Qiao Applied Catalysis A: General 176 (1999)

  10. aqueous phase catalysis: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 292 Magnetic catalysis in hot...

  11. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    K. Lee Semiconductor Photocatalysis in Advanced Oxidationthermal) catalysis or photocatalysis on nanoporous supportswith Heterogeneous Photocatalysis using Nanostructured

  12. asymmetric catalysis solvent-free: Topics by E-print Network

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

    X Lewis Acid Catalysis Brnsted Acid Catalysis X Johnson, Jeff S. 2 Multidimensional free energy relationships in asymmetric catalysis. Open Access Theses and Dissertations...

  13. Is It Homogeneous or Heterogeneous Catalysis Derived from [RhCp*Cl2]2? In Operando-XAFS, Kinetic and Crucial Kinetic Poisoning Evidence for Subnanometer Rh4 Cluster-Based Benzene Hydrogenation Catalysis

    SciTech Connect (OSTI)

    Bayram, Ercan; Linehan, John C.; Fulton, John L.; Roberts, John A.; Szymczak, Nathaniel; Smurthwaite, Tricia D.; Ozkar, Saim; Balasubramanian, Mahalingam; Finke, Richard G.

    2011-11-23T23:59:59.000Z

    Determining the true, kinetically dominant catalytically active species, in the classic benzene hydrogenation system pioneered by Maitlis and co-workers 34 years ago starting with [RhCp*Cl2]2 (Cp* = [{eta}5-C5(CH3)5]), has proven to be one of the most challenging case studies in the quest to distinguish single-metal-based 'homogeneous' from polymetallic, 'heterogeneous' catalysis. The reason, this study will show, is the previous failure to use the proper combination of (i) operando spectroscopy to determine the dominant form(s) of the precatalyst's mass under catalysis (i.e., operating) conditions, plus then and crucially also (ii) the previous lack of the necessary kinetic studies, catalysis being a 'wholly kinetic phenomenon' as J. Halpern long ago noted. An important contribution from this study will be to reveal the power of quantitiative kinetic poisoning experiments for distinguishing single-metal, or in this case subnanometer Rh4 cluster-based catalysis from larger, polymetallic Rh(0)n nanoparticle catalysis, at least under favorable conditions. The combined operando-XAFS (X-ray absorption fine structure) spectroscopy and kinetic evidences provide a compelling case for Rh4-based, with average stoichiometry 'Rh4Cp*2.4Cl4Hc', benzene hydrogenation catalysis in 2-propanol with added Et3N and at 100 C and 50 atm initial H2 pressure. The results also reveal, however, that if even ca. 1.4% of the total soluble Rh(0)n had formed nanoparticles, then those Rh(0)n nanoparticles would have been able to account for all the observed benzene hydrogenation catalytic rate (using commercial, ca. 2 nm, polyethyleneglycol-dodecylether hydrosol stabilized Rh(0)n nanoparticles as a model system). The results 'especially the poisoning methodology developed and employed' are of significant, broader interest since determining the nature of the true catalyst continues to be a central, often vexing issue in any and all catalytic reactions. The results are also of fundamental interest in that they add to a growing body of evidence indicating that certain, appropriately ligated, coordinatively unsaturated, subnanometer M4 transition-metal clusters can be relatively robust catalysts. Also demonstrated herein is that Rh4 clusters are poisoned by Hg(0), demonstrating for the first time that the classic Hg(0) poisoning test of 'homogeneous' vs 'heterogeneous'catalysts cannot distinguish Rh4-based subnanometer catalysts from Rh(0)n nanoparticle catalysts, at least for the present examples of these two specific, Rh-based catalysts.

  14. acid-base catalysis ii: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 232 Magnetic catalysis in hot...

  15. Metal complexes with bifunctional imidazolyl phosphines for catalytic organic transformations : applications in homogeneous and polymer supported alkene isomerization , and hydrogen deuterium exchange

    E-Print Network [OSTI]

    Erdogan, Gulin

    2012-01-01T23:59:59.000Z

    W. A. Applied homogeneous catalysis with organometallicW. A. Applied homogeneous catalysis with organometallicR. Applied organometallic chemistry and catalysis; Oxford

  16. catalysis | EMSL

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

    analysis radionuclides aerosols catalysis renewable energy subsurface geological field battery materials catalyst beds geochemistry ion microprobe high sensitivity high mass...

  17. DOE Laboratory Catalysis Research Symposium - Abstracts

    SciTech Connect (OSTI)

    Dunham, T.

    1999-02-01T23:59:59.000Z

    The conference consisted of two sessions with the following subtopics: (1) Heterogeneous Session: Novel Catalytic Materials; Photocatalysis; Novel Processing Conditions; Metals and Sulfides; Nuclear Magnetic Resonance; Metal Oxides and Partial Oxidation; Electrocatalysis; and Automotive Catalysis. (2) Homogeneous Catalysis: H-Transfer and Alkane Functionalization; Biocatalysis; Oxidation and Photocatalysis; and Novel Medical, Methods, and Catalyzed Reactions.

  18. INSTITUTE FOR INTEGRATED CATALYSIS Catalysis Research for

    E-Print Network [OSTI]

    . This work includes catalysis for upgrading biomass feedstocks; for chemical energy storage, retrieval

  19. 2012 Catalysis Lectures

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

    Bert Weckhuysen, who holds the chair of Inorganic Chemistry and Catalysis at Utrecht University, will give a series of catalysis lectures during his sabbatical period at...

  20. Heterogeneous Catalysis Environmental Catalysis and Processes

    E-Print Network [OSTI]

    Vardi, Amichay

    Department of Chemical Engineering Ben ­ Gurion University of the Negev Blechner Center for Applied CatalysisHeterogeneous Catalysis Environmental Catalysis and Processes Renewable Fuels M. Herskowitz Nanotechnology and advanced methods are applied in use inspired research #12;Fundamental research of catalytic

  1. Catalysis Workshop

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t z C o . C lKieling ,Catalysis Science

  2. Heterodimerization of Olefins. 1. Hydrovinylation Reactions of Olefins That Are Amenable to Asymmetric Catalysis

    E-Print Network [OSTI]

    RajanBabu, T. V. "Babu"

    , 151. (b) Chauvin, Y.; Olivier, H. Dimerization and Codimerization. In Applied Homogeneous Catalysis) Jolly, P. W.; Wilke, G. Hydrovinylation. In Applied Homoge- neous Catalysis with Organometallic to Asymmetric Catalysis T. V. RajanBabu,* Nobuyoshi Nomura, Jian Jin, Malay Nandi, Haengsoon Park, and Xiufeng

  3. Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference

    SciTech Connect (OSTI)

    Not Available

    1990-03-01T23:59:59.000Z

    Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases. (CBS)

  4. Journal of Catalysis 191, 4654 (2000) doi:10.1006/jcat.1999.2798, available online at http://www.idealibrary.com on

    E-Print Network [OSTI]

    Androulakis, Ioannis (Yannis)

    2000-01-01T23:59:59.000Z

    high-temperature processes based on heterogeneous catalysis may involve homogeneous gas-phase reactionsJournal of Catalysis 191, 46­54 (2000) doi:10.1006/jcat.1999.2798, available online at http

  5. Zeolite catalysis

    SciTech Connect (OSTI)

    Chu, P.; Garwood, W.E.; Schwartz, A.B.

    1988-11-29T23:59:59.000Z

    This patent describes a process for preparing hydrocarbons boiling in the gasoline and/or distillate range by contacting a feedstock comprising lower molecular weight olefins in a reaction zone under conditions of elevated temperature and pressure with a shape selective crystalline aluminosilicate catalyst, comprising: reducing the non-shape selective surface-cracking and/or surface isomerization activity of the aluminosilicate catalyst by a process comprising: preparing an aqueous solution comprising colloidal silica, optionally an organic directing agent, and a source of hydroxide ions; mixing the aqueous solution with an aqueous dispersion of shape-selective crystalline aluminosilicate to form a homogeneous mixture which is subsequently heated; adding an aqueous solution comprising a source of fluoride ions to the homogeneous mixture to form a reactive composition; heating the reactive composition at a temperature to effectively form a surface-deactivated catalyst comprising a crystalline fluoride-containing silica outer shell on an aluminosilicate; withdrawing the surface-deactivated catalyst from the reactive composition for washing, drying, and calcining of the catalyst; and removing the catalyst to the reaction zone for contact with the olefin feedstock.

  6. Topics for letter "c" | EMSL

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

    Wing RadEMSL Virtual Tour Topics for letter "c" carbon carbon cycling carbon dioxide carbon sequestration Cascade catalysis catalytic reaction cation migration chemical...

  7. SOUTHWEST CATALYSIS 2012 SPRING SYMPOSIUM

    E-Print Network [OSTI]

    ) "Catalysis to Meet the Energy Challenge" 11:00 AM Southwest Catalysis Society Excellence in Applied CatalysisSOUTHWEST CATALYSIS SOCIETY 2012 SPRING SYMPOSIUM April 20, 2012 Duncan Hall - McMurtry Auditorium registration fee is $50, which includes North American Catalysis Society and SWCS yearly membership dues, along

  8. EMSL - In situ catalysis

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

    situ-catalysis en New generation NMR bioreactor coupled with high-resolution NMR spectroscopy leads to novel discoveries in Moorella http:www.emsl.pnl.govemslwebpublications...

  9. Computational Catalysis and Electrocatalysis

    E-Print Network [OSTI]

    · Hydrogen storage · Photocatalysis #12;Fuel cell electrocatalysts Parallelism between bimetallics projects: photo-catalysis water decomposes over a catalyst producing oxygen and hydrogen From members

  10. SOUTHWEST CATALYSIS 2013 SPRING SYMPOSIUM

    E-Print Network [OSTI]

    Natelson, Douglas

    -free Substrates" 11:05 AM Southwest Catalysis Society Excellence in Applied Catalysis Award James "Jerry" SpiveySOUTHWEST CATALYSIS SOCIETY 2013 SPRING SYMPOSIUM Friday, April 26, 2013 Grand Hall of the Ley registration fee is $50, which includes North American Catalysis Society and SWCS yearly membership dues, along

  11. Dendrimer-encapsulated metal nanoparticles: synthesis, characterization, and applications to catalysis 

    E-Print Network [OSTI]

    Niu, Yanhui

    2004-09-30T23:59:59.000Z

    The research in this dissertation examines the chemistry and applications of dendrimers in homogeneous catalysis. We examined interactions between dendrimers and charged probe molecules, prepared dendrimer-encapsulated metal nanoparticles...

  12. A Hydrogen-Evolving Ni(P2N2)2 Electrocatalyst Covalently Attached to a Glassy Carbon Electrode: Preparation, Characterization, and Catalysis. Comparisons With the Homogeneous Analog

    SciTech Connect (OSTI)

    Das, Atanu K.; Engelhard, Mark H.; Bullock, R. Morris; Roberts, John A.

    2014-07-07T23:59:59.000Z

    A hydrogen-evolving homogeneous Ni(P2N2)2 electrocatalyst with peripheral ester groups has been covalently attached to a 1,2,3-triazolyllithium-terminated glassy carbon electrode. The surface-confined complex is an electroctalyst for hydrogen evolution, showing onset of catalytic current at the same potential as the soluble parent complex. X-ray photoemission spectra show excellent agreement between the coupled and homogeneous species. Coverage approaches a dense monolayer. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. The XPS measurements were performed at EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  13. Catalysis Research for Energy Independence

    E-Print Network [OSTI]

    yields insights into improving the industrial catalyst for oil refining, chemicals processing into chemical fuels. In addition, we conduct applied catalysis research with industrial, academic, and other collaborate with catalysis leaders in academia, industry, and national laboratories. Research in Science

  14. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    SciTech Connect (OSTI)

    Overbury, Steven {Steve} H [ORNL; Coates, Leighton [ORNL; Herwig, Kenneth W [ORNL; Kidder, Michelle [ORNL

    2011-10-01T23:59:59.000Z

    This report summarizes the Workshop on Neutron Scattering Techniques for Studies in Catalysis, held at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on September 16 and 17, 2010. The goal of the Workshop was to bring experts in heterogeneous catalysis and biocatalysis together with neutron scattering experimenters to identify ways to attack new problems, especially Grand Challenge problems in catalysis, using neutron scattering. The Workshop locale was motivated by the neutron capabilities at ORNL, including the High Flux Isotope Reactor (HFIR) and the new and developing instrumentation at the SNS. Approximately 90 researchers met for 1 1/2 days with oral presentations and breakout sessions. Oral presentations were divided into five topical sessions aimed at a discussion of Grand Challenge problems in catalysis, dynamics studies, structure characterization, biocatalysis, and computational methods. Eleven internationally known invited experts spoke in these sessions. The Workshop was intended both to educate catalyst experts about the methods and possibilities of neutron methods and to educate the neutron community about the methods and scientific challenges in catalysis. Above all, it was intended to inspire new research ideas among the attendees. All attendees were asked to participate in one or more of three breakout sessions to share ideas and propose new experiments that could be performed using the ORNL neutron facilities. The Workshop was expected to lead to proposals for beam time at either the HFIR or the SNS; therefore, it was expected that each breakout session would identify a few experiments or proof-of-principle experiments and a leader who would pursue a proposal after the Workshop. Also, a refereed review article will be submitted to a prominent journal to present research and ideas illustrating the benefits and possibilities of neutron methods for catalysis research.

  15. Heterogeneous Catalysis on Atomically Dispersed Supported Metals...

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

    Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction on Multifunctional Pd Catalysts. Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction...

  16. Polyisobutylene as a Polymer Support for Homogeneous Catalysis

    E-Print Network [OSTI]

    Hongfa, Chayanant

    2010-01-14T23:59:59.000Z

    and filtration. PEG is insoluble in hexane, diethyl ether, tert-butylmethyl ether (TBME), isopropyl alcohol, and cold ethanol. These are the solvents usually used for the precipitation process. 14 PEG is usefully soluble in a wide range of solvents... (>80% ee) and high yield (>80%). The PEG-bound Cinchona alkaloid 6 was recovered (8) 11 by solvent precipitation with diethyl ether and recycled through five cycles with p- chlorostyrene as a substrate. The average yield of all 5 cycles was 93...

  17. Phase selectively soluble polymer supports to facilitate homogeneous catalysis

    E-Print Network [OSTI]

    Ortiz-Acosta, Denisse

    2009-05-15T23:59:59.000Z

    Soluble polymers that have phase selective solubility are useful in synthesis because they simplify purification and separation. Such selectively soluble polymers simplify catalyst, reagent, and product recovery and enable the use of Green chemistry...

  18. Homogeneous and Interfacial Catalysis in 3D Controlled Environment | The

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School football Highdefault Sign In AboutAmes Laboratory

  19. Magnetic catalysis and inverse magnetic catalysis in QCD

    E-Print Network [OSTI]

    Niklas Mueller; Jan M. Pawlowski

    2015-02-27T23:59:59.000Z

    We investigate the effects of strong magnetic fields on the QCD phase structure at vanishing density by solving the gluon and quark gap equations, and by studying the dynamics of the quark scattering with the four-fermi coupling. The chiral crossover temperature as well as the chiral condensate are computed. For asymptotically large magnetic fields we find magnetic catalysis, while we find inverse magnetic catalysis for intermediate magnetic fields. Moreover, for large magnetic fields the chiral phase transition for massless quarks turns into a crossover. The underlying mechanisms are then investigated analytically within a few simplifications of the full numerical analysis. We find that a combination of gluon screening effects and the weakening of the strong coupling is responsible for the phenomenon of inverse catalysis. In turn, the magnetic catalysis at large magnetic field is already indicated by simple arguments based on dimensionality.

  20. Synthetic Catalysis of Amide Isomerization

    E-Print Network [OSTI]

    Lectka, Thomas

    , they may play other roles in vivo, including the catalysis of protein folding, functioning as auxiliary seem to be a possible way to catalyze protein folding in vitro, and experiments along these lines

  1. Selective catalysis utilizing bifunctionalized MCM-41 mesoporous materials

    SciTech Connect (OSTI)

    Strosahl, Kasey Jean

    2005-05-01T23:59:59.000Z

    Selective catalysis is a field that has been under intense investigation for the last 100 years. The most widely used method involves catalysts with stereochemical selectivity. In this type of catalysis, the catalyst controls which reactants will be transformed into the desired product. The secret to employing this type of catalysis, though, is to design the proper catalyst, which can be difficult. One may spend as much time developing the catalyst as spent separating the various products achieved. Another method of selective catalysis is now being explored. The method involves utilizing a multifunctional mesoporous silica catalyst with a gate-keeping capability. Properly functionalized mesoporous materials with well-defined pore morphology and surface properties can provide an ideal three-dimensional environment for anchoring various homogeneous catalysts. These materials can circumvent the multi-sited two-dimensional nature most heterogeneous systems have without adversely impacting the reactant diffusivity. These single-site nanostructured catalysts with ordered geometrical structure are advantageous in achieving high selectivity and reactivity. Mesoporous materials can be prepared to include pores lined homogeneously with tethered catalysts via co-condensation. Additionally, these materials can be reacted with another (RO){sub 3}Si{approx}Z group by using the traditional grafting method; this group is anchored predominantly at the entrances to the pores rather than inside the pores. Thus, if these {approx}Z groups are chosen properly, they can select certain molecules to enter the pores and be converted to products (Scheme 1). In such multifunctional catalysts, the selectivity depends on the discrimination of the gatekeeper. Gate-keeping MCM-41 materials are at the forefront of catalytic substances.

  2. Enhanced Micellar Catalysis LDRD.

    SciTech Connect (OSTI)

    Betty, Rita G.; Tucker, Mark David; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael

    2012-12-01T23:59:59.000Z

    The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesota's Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

  3. Fuel Synthesis Catalysis Laboratory (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-07-01T23:59:59.000Z

    This fact sheet provides information about Fuel Synthesis Catalysis Laboratory capabilities and applications at NREL's National Bioenergy Center.

  4. Fuel Synthesis Catalysis Laboratory (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-07-01T23:59:59.000Z

    This fact sheet provides information about Fuel Synthesis Catalysis Laboratory capabilities and applications at NREL's National Bioenergy Center.

  5. CATALYSIS SCIENCE AND TECHNOLOGY

    SciTech Connect (OSTI)

    M. ABRAMS; R. BAKER; ET AL

    2000-08-01T23:59:59.000Z

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Our objectives were to develop a multidisciplinary team and capabilities to develop a fundamental understanding of homogeneous, heterogeneous, and heterogenized catalysts. With the aid of theoretical chemistry approaches we explored and characterized the chemical reactivity and physical properties of a large number of catalytic systems.

  6. Charge Transfer and Support Effects in Heterogeneous Catalysis

    E-Print Network [OSTI]

    Hervier, Antoine

    2012-01-01T23:59:59.000Z

    T. ; Haruta, M.  Applied Catalysis A:  General 1998, 169, Albert Vannice, M.  Applied Catalysis A: General 1994, 113, Viswanath, R.  P.  Applied Catalysis A: General 2001, 208, 

  7. Charge Transfer and Catalysis at the Metal-Support Interface

    E-Print Network [OSTI]

    Baker, Lawrence Robert

    2012-01-01T23:59:59.000Z

    A. ; Miko?ajska, A. Applied Catalysis A: General 2002, 233,T. ; Haruta, M. Applied Catalysis A: General 1998, 169,Albert Vannice, M. Applied Catalysis A: General 1994, 113, (

  8. Basic Research Needs: Catalysis for Energy

    SciTech Connect (OSTI)

    Bell, Alexis T.; Gates, Bruce C.; Ray, Douglas; Thompson, Michael R.

    2008-03-11T23:59:59.000Z

    The report presents results of a workshop held August 6-8, 2007, by DOE SC Basic Energy Sciences to determine the basic research needs for catalysis research.

  9. Workshop: Synchrotron Applications in Chemical Catalysis | Stanford...

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

    Applications in Chemical Catalysis Tuesday, October 25, 2011 - 8:00am 2011 SSRLLCLS Annual Users Conference This workshop, part of the 2011 SSRLLCLS Annual Users...

  10. Plasma Assisted Catalysis System for NOx Reduction

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

    2 NOXTECH NOXTECH PLASMA ASSISTED CATALYSIS SYSTEM FOR NOx REDUCTION BY NOXTECH With the Support & Cooperation of DOE Noxtech, Inc. *Delaware Corporation registered to do business...

  11. Thermochemical Conversion: Using Heat and Catalysis to Make Biofuels...

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

    Conversion: Using Heat and Catalysis to Make Biofuels and Bioproducts Thermochemical Conversion: Using Heat and Catalysis to Make Biofuels and Bioproducts The Bioenergy...

  12. Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis...

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

    Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Abstract: The research described in...

  13. Column Asymmetric Catalysis for -Lactam Synthesis

    E-Print Network [OSTI]

    Lectka, Thomas

    Column Asymmetric Catalysis for -Lactam Synthesis Ahmed M. Hafez, Andrew E. Taggi, Harald Wack that constitute the packing of a series of "reaction columns". This process was applied to the catalytic- and diastereoselectivity. In the realm of chiral synthesis and drug discovery, asym- metric catalysis1 and solid

  14. Einstein homogeneous riemannian fibrations 

    E-Print Network [OSTI]

    Araujo, Fatima

    2008-01-01T23:59:59.000Z

    This thesis is dedicated to the study of the existence of homogeneous Einstein metrics on the total space of homogeneous fibrations such that the fibers are totally geodesic manifolds. We obtain the Ricci curvature of ...

  15. Center for Catalysis at Iowa State University

    SciTech Connect (OSTI)

    Kraus, George A.

    2006-10-17T23:59:59.000Z

    The overall objective of this proposal is to enable Iowa State University to establish a Center that enjoys world-class stature and eventually enhances the economy through the transfer of innovation from the laboratory to the marketplace. The funds have been used to support experimental proposals from interdisciplinary research teams in areas related to catalysis and green chemistry. Specific focus areas included: • Catalytic conversion of renewable natural resources to industrial materials • Development of new catalysts for the oxidation or reduction of commodity chemicals • Use of enzymes and microorganisms in biocatalysis • Development of new, environmentally friendly reactions of industrial importance These focus areas intersect with barriers from the MYTP draft document. Specifically, section 2.4.3.1 Processing and Conversion has a list of bulleted items under Improved Chemical Conversions that includes new hydrogenation catalysts, milder oxidation catalysts, new catalysts for dehydration and selective bond cleavage catalysts. Specifically, the four sections are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D) All funded projects are part of a soybean or corn biorefinery. Two funded projects that have made significant progress toward goals of the MYTP draft document are: Catalysts to convert feedstocks with high fatty acid content to biodiesel (Kraus, Lin, Verkade) and Conversion of Glycerol into 1,3-Propanediol (Lin, Kraus). Currently, biodiesel is prepared using homogeneous base catalysis. However, as producers look for feedstocks other than soybean oil, such as waste restaurant oils and rendered animal fats, they have observed a large amount of free fatty acids contained in the feedstocks. Free fatty acids cannot be converted into biodiesel using homogeneous base-mediated processes. The CCAT catalyst system offers an integrated and cooperative catalytic system that performs both esterification (of free fatty acids) and transesterification (of soybean oil) in a one-pot fashion. This will allow the biodiesel producers to use the aforementioned cheap feedstocks without any pretreatment. In addition, the catalyst system is heterogeneous and is highly recyclable and reusable. Although markets currently exist for glycerin, concern is mounting that the price of glycerin may plummet to $.05 - $.10 per pound if future production exceeds demand. Developing a system to make high value chemicals such as 1,3-propanediol from the glycerin stream will add value for biodiesel producers who implement the new technology. Given the fact that both DuPont and Shell chemicals have announced the commercialization of two new PDO-based polymers, a rapid increase of market demand for a cheaper PDO source is very likely. 4. Comparison of actual accomplishments with goals and objectives From our progress reports, the four areas are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D)

  16. "Nanocrystal bilayer for tandem catalysis"

    SciTech Connect (OSTI)

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24T23:59:59.000Z

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  17. Nanocrystal assembly for tandem catalysis

    DOE Patents [OSTI]

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

    2014-10-14T23:59:59.000Z

    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  18. Magnetic Catalysis vs Magnetic Inhibition

    E-Print Network [OSTI]

    Kenji Fukushima; Yoshimasa Hidaka

    2012-09-06T23:59:59.000Z

    We discuss the fate of chiral symmetry in an extremely strong magnetic field B. We investigate not only quark fluctuations but also neutral meson effects. The former would enhance the chiral-symmetry breaking at finite B according to the Magnetic Catalysis, while the latter would suppress the chiral condensate once B exceeds the scale of the hadron structure. Using a chiral model we demonstrate how neutral mesons are subject to the dimensional reduction and the low dimensionality favors the chiral-symmetric phase. We point out that this effect, the Magnetic Inhibition, can be a feasible explanation for recent lattice-QCD data indicating the decreasing behavior of the chiral-restoration temperature with increasing B.

  19. Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...

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

    rappe.pdf More Documents & Publications Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI Emission Control Low-Temperature HydrocarbonCO Oxidation Catalysis in...

  20. UNCORRECTEDPROOF Applied Catalysis B: Environmental 793 (2000) 19

    E-Print Network [OSTI]

    Jardim, Wilson de Figueiredo

    2000-01-01T23:59:59.000Z

    UNCORRECTEDPROOF Applied Catalysis B: Environmental 793 (2000) 1­9 Catalyst deactivation in the gas;UNCORRECTEDPROOF 2 R.M. Alberici et al. / Applied Catalysis B: Environmental 793 (2000) 1­9 when photo-oxidizing 1

  1. Shining Light on Catalysis | Stanford Synchrotron Radiation Lightsourc...

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

    Shining Light on Catalysis Tuesday, July 19, 2011 - 4:38pm SSRL Conference Room 137-322 Jeroen A. van Bokhoven, Professor for Heterogeneous Catalysis Institute for Chemical and...

  2. Catalysis by Supported Gold Nanoclusters D. Wayne Goodman

    E-Print Network [OSTI]

    Goodman, Wayne

    by the selective oxidation of propylene to propylene oxide by gold,[4] alkene and arene hydrogenation catalysis,[5

  3. SouthWest Catalysis Society 2011 Spring Symposium

    E-Print Network [OSTI]

    Natelson, Douglas

    Award for Excellence in Applied Catalysis later in the day. On-site registration will begin at 7:30 AMSouthWest Catalysis Society 2011 Spring Symposium April 15, 2011 BioScience Research Collaborative in teaching and in the field of catalysis. Additionally, the Society is proud to present the inaugural SWCS

  4. Geometrically induced magnetic catalysis and critical dimensions

    E-Print Network [OSTI]

    Antonino Flachi; Kenji Fukushima; Vincenzo Vitagliano

    2015-02-21T23:59:59.000Z

    We discuss the combined effect of magnetic fields and geometry in interacting fermionic systems. At leading order in the heat-kernel expansion, the infrared singularity (that in flat space leads to the magnetic catalysis) is regulated by the chiral gap effect and the catalysis is deactivated by effect of the curvature. We discover that an infrared singularity may reappear from higher-order terms in the heat kernel expansion leading to a novel form of geometrically induced magnetic catalysis (absent in flat space). The dynamical mass squared is then modified not only due to the chiral gap effect by an amount proportional to the curvature, but also by a magnetic shift $\\propto (4-D)eB$ where $D$ represents the number of space-time dimensions. We argue that $D=4$ is a critical dimension across which the behaviour of the magnetic shift changes qualitatively.

  5. Geometrically induced magnetic catalysis and critical dimensions

    E-Print Network [OSTI]

    Flachi, Antonino; Vitagliano, Vincenzo

    2015-01-01T23:59:59.000Z

    We discuss the combined effect of magnetic fields and geometry in interacting fermionic systems. At leading order in the heat-kernel expansion, the infrared singularity (that in flat space leads to the magnetic catalysis) is regulated by the chiral gap effect and the catalysis is deactivated by effect of the curvature. We discover that an infrared singularity may reappear from higher-order terms in the heat kernel expansion leading to a novel form of geometrically induced magnetic catalysis (absent in flat space). The dynamical mass squared is then modified not only due to the chiral gap effect by an amount proportional to the curvature, but also by a magnetic shift $\\propto (4-D)eB$ where $D$ represents the number of space-time dimensions. We argue that $D=4$ is a critical dimension across which the behaviour of the magnetic shift changes qualitatively.

  6. Geometrically induced magnetic catalysis and critical dimensions

    E-Print Network [OSTI]

    Antonino Flachi; Kenji Fukushima; Vincenzo Vitagliano

    2015-04-27T23:59:59.000Z

    We discuss the combined effect of magnetic fields and geometry in interacting fermionic systems. At leading order in the heat-kernel expansion, the infrared singularity (that in flat space leads to the magnetic catalysis) is regulated by the chiral gap effect, and the catalysis is deactivated by the effect of the scalar curvature. We discover that an infrared singularity is found in higher-order terms that mix the magnetic field with curvature, and these lead to a novel form of geometrically induced magnetic catalysis. The dynamical mass squared is then modified not only due to the chiral gap effect by an amount proportional to the curvature, but also by a magnetic shift $\\propto (4-D)eB$, where $D$ represents the number of space-time dimensions. We argue that $D=4$ is a critical dimension across which the behavior of the magnetic shift changes qualitatively.

  7. Nanoscale Advances in Catalysis and Energy Applications

    SciTech Connect (OSTI)

    Li, Yimin; Somorjai, Gabor A.

    2010-05-12T23:59:59.000Z

    In this perspective, we present an overview of nanoscience applications in catalysis, energy conversion, and energy conservation technologies. We discuss how novel physical and chemical properties of nanomaterials can be applied and engineered to meet the advanced material requirements in the new generation of chemical and energy conversion devices. We highlight some of the latest advances in these nanotechnologies and provide an outlook at the major challenges for further developments.

  8. USD Catalysis Group for Alternative Energy

    SciTech Connect (OSTI)

    James D. Hoefelmeyer, Ranjit Koodali, Grigoriy Sereda, Dan Engebretson, Hao Fong, Jan Puszynski, Rajesh Shende, Phil Ahrenkiel

    2012-03-13T23:59:59.000Z

    The South Dakota Catalysis Group (SDCG) is a collaborative project with mission to develop advanced catalysts for energy conversion with two primary goals: (1) develop photocatalytic systems in which polyfunctionalized TiO2 are the basis for hydrogen/oxygen synthesis from water and sunlight (solar fuels group), (2) develop new materials for hydrogen utilization in fuel cells (fuel cell group). In tandem, these technologies complete a closed chemical cycle with zero emissions.

  9. Blue Ruthenium Dimer Catalysis for Hydrogen Generation | Advanced...

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

    | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Blue Ruthenium Dimer Catalysis for Hydrogen Generation APRIL 15, 2013 Bookmark and Share Key...

  10. "Seeing" hydrogen atoms to unveil enzyme catalysis | ornl.gov

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

    "Seeing" hydrogen atoms to unveil enzyme catalysis Image shows nuclear density maps in the active site of DHFR where the catalytic group Asp27 and substrate folate have...

  11. Catalysis by Design - Theoretical and Experimental Studies of...

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

    Lean NOx Traps - Microstructural Studies of Real World and Model Catalysts Catalysts via First Principles Catalysis by Design: Bridging the Gap between Theory and Experiments...

  12. Catalysis by Design: Bridging the Gap between Theory and Experiments...

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

    between Theory and Experiments Catalysis by Design: Bridging the Gap between Theory and Experiments Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research...

  13. Catalysis by Design: Bridging the Gap Between Theory and Experiments...

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

    Between Theory and Experiments at Nanoscale Level Catalysis by Design: Bridging the Gap Between Theory and Experiments at Nanoscale Level Studies on a simple platinum-alumina...

  14. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    Pelzer, K. Philippot, M. G´ mez, o G. Muller, P. Lecante, B.F. Malbosc, Y. Kihn, M. G´ mez Green Chemistry submitted. oPicurelli, A. Oliva, M. G´ mez, V. Branchadell, R.M. Ortu˜ o

  15. End Functinalization of Polyisobutylenes and their Applications in Dyeing Polyolefins and in Homogeneous Catalysis

    E-Print Network [OSTI]

    Boralugodage, Nilusha P

    2013-06-05T23:59:59.000Z

    by electrophilic aromatic substitution reactions of PIB-diazonium salt 47a and 51a. ..................... 39 FIGUIRE 8. UV_vis Spectra of solutions of PIB bound azo dyes 52, 54, 55 and 56 in heptane..., conventional radical, anionic 2 or cationic polymerization methods offer very limited possibilities of using directly functional monomers due to their secondary interactions with initiator/catalyst systems which consist of metal salts. Therefore, post...

  16. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    for Nanostructured Materials, University of Trieste, via A.Valerio 2, 34127, Trieste, Italy Laboratorio Nazionale TASC34012, Basovizza (Trieste), Italy Chemistry Department,

  17. Converting Homogeneous to Heterogeneous in Electrophilic Catalysis using Monodisperse Metal Nanoparticles

    E-Print Network [OSTI]

    Witham, Cole A.

    2011-01-01T23:59:59.000Z

    Synthesis of One Nanometer Rh and Pt Particles Supported on Mesoporous Silica: Catalytic Activity for Ethylene and Pyrrole

  18. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA Department of Energy, National Energy Technology Laboratory, Pittsburgh, PA The design

  19. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    measurements. With an infrared laser, heating and coolingbeam for detection. Infrared laser heating is a successful

  20. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    size e?ect in the Fischer-Tropsch synthesis. ” Stud. Surf.E. Rytter, A. Holmen ”Fischer-Tropsch synthesis over ?-Al 2Rytter, A. Holmen ”Fischer-Tropsch synthesis on Co supported

  1. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    or sulfated zirconia (MOx) a?ords propene and supportedium(III) catalysts, (allyl) 2 Ir-O-MOx. These catalysts were

  2. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    due to low solubility of syngas remain a problem for e?cientof methane to form syngas. 2 However, the structure andin the production of syngas and hydrogen from fossil and

  3. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    Department of Chemical and Petroleum Engineering, UniversityDepartment of Chemical and Petroleum Engineering, University

  4. ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis

    E-Print Network [OSTI]

    Somorjai Ed., G.A.

    2007-01-01T23:59:59.000Z

    led to outstanding catalysts, showing an excellent activity without leaching of metal up to ten recycling

  5. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    E-Print Network [OSTI]

    Pennycook, Steve

    -EM Fischer Tropsch Catalysis on Fe- or Co-catalysts, ,,CTL" Coal to Liquids ­ ,a rough (?) analogy #12;Peter Albers, AQ-EM Carbonaceous Deposits on Catalysts #12;Peter Albers, AQ-EM IINS on Coked Catalysts from Industrial Plants High-temperature and low-temperature cokes deposited on catalysts during

  6. Frontiers in Catalysis Science and Engineering Seminar Series

    E-Print Network [OSTI]

    Frontiers in Catalysis Science and Engineering Seminar Series "Frustrated Lewis Pairs": Metal and applied to develop metal-free hydrogenations for C=N bonds in a variety of organic substrates. In addition, alkynes, cyclopropanes, CO2 and N2O. The implications of the discovery of such systems to catalysis

  7. Periodic Solutions of a Nonlinear Evolution Problem from Heterogeneous Catalysis

    E-Print Network [OSTI]

    Bothe, Dieter

    Periodic Solutions of a Nonlinear Evolution Problem from Heterogeneous Catalysis Dieter Bothe for heterogeneous catalysis in a stirred multi-phase chemical reactor. Since the appearance of T-periodic feeds for this evolution problem are provided and applied to the class of reaction-diffusion systems mentioned above. AMS

  8. Frontiers in Catalysis Science and Engineering Seminar Series

    E-Print Network [OSTI]

    Frontiers in Catalysis Science and Engineering Seminar Series Heterogenized M-Salen Catalysts complexes are widely applied as catalysts for numerous important enantioselective reactions. The reactions catalysis (e.g. Co-salen for epoxide ring-opening or Al-salen conjugate additions of cyanide). The design

  9. Materials and interfaces for catalysis, separation, storage, and environmental applications

    E-Print Network [OSTI]

    Li, Mo

    Materials and interfaces for catalysis, separation, storage, and environmental applications collaborative effort in cutting-edge fundamental and applied research to discover and develop polymeric' problems such as inexpensive CO2 capture, energy-efficient and high-performance catalysis and separations

  10. Heterogeneous Catalysis DOI: 10.1002/anie.201209476

    E-Print Network [OSTI]

    Kik, Pieter

    Heterogeneous Catalysis DOI: 10.1002/anie.201209476 Trends in the Binding Strength of Surface? These questions are at the heart of many fundamental and practical problems, ranging from heterogeneous catalysis to important applied processes con- nected to materials science. In particular the interaction of oxygen

  11. Lithium Diisopropylamide-Mediated Enolization: Catalysis by Hemilabile Ligands

    E-Print Network [OSTI]

    Collum, David B.

    Lithium Diisopropylamide-Mediated Enolization: Catalysis by Hemilabile Ligands Antonio Ramirez of a lithium diisopropylamide (LDA)-mediated ester enolization. Hemilabile amino ether MeOCH2CH2NMe2, binding-based catalysis are thwarted by the occlusion of the catalyst on the lithium salt products and byproducts (eq 1

  12. Dynamic control of catalysis within biological cells

    E-Print Network [OSTI]

    Biman Jana; Biman Bagchi

    2011-05-26T23:59:59.000Z

    We develop a theory of enzyme catalysis within biological cells where the substrate concentration [S](t) is time dependent, in contrast to the Michaelis-Menten theory that assumes a steady state. We find that the time varying concentration can combine, in a non-linear way, with the ruggedness of the free energy landscape of enzymes (discovered both in single molecule studies and in simulations) to provide a highly efficient switch (or, bifurcation) between two catalytically active states, at a critical substrate concentration. This allows a dynamic control of product synthesis in cell.

  13. Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...

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

    National Laboratory U.S. Department of Energy Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI Emission Control Ken Rapp, Liyu Li, Jonathan Male, Dave King...

  14. Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...

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

    D.C. acep03rappe.pdf More Documents & Publications Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI Emission Control Low-Temperature HydrocarbonCO...

  15. Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...

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

    (OFCVT). deer07rappe.pdf More Documents & Publications Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI Emission Control Low-Temperature HydrocarbonCO...

  16. Redox, haem and CO in enzymatic catalysis and regulation

    E-Print Network [OSTI]

    Ragsdale, Stephen W.

    The present paper describes general principles of redox catalysis and redox regulation in two diverse systems. The first is microbial metabolism of CO by the Wood–Ljungdahl pathway, which involves the conversion of CO or ...

  17. Theoretical investigation of solar energy conversion and water oxidation catalysis

    E-Print Network [OSTI]

    Wang, Lee-Ping

    2011-01-01T23:59:59.000Z

    Solar energy conversion and water oxidation catalysis are two great scientific and engineering challenges that will play pivotal roles in a future sustainable energy economy. In this work, I apply electronic structure ...

  18. Frontiers in Catalysis Science and Engineering Materials Science

    E-Print Network [OSTI]

    Frontiers in Catalysis Science and Engineering Materials Science Chemical Imaging Date: May 13 the quality of human life but also critical to our survival. To power the planet for a better future

  19. Catalysis Working Group Kick-Off Meeting Agenda

    Broader source: Energy.gov [DOE]

    Agenda for the kick-off meeting of the U.S. Department of Energy Fuel Cell Technologies Program's Catalysis Working Group, held May 14, 2012, in Arlington, Virginia.

  20. Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications

    SciTech Connect (OSTI)

    Parks, II, James E [ORNL; Storey, John Morse [ORNL; Theiss, Timothy J [ORNL; Ponnusamy, Senthil [ORNL; Ferguson, Harley Douglas [ORNL; Williams, Aaron M [ORNL; Tassitano, James B [ORNL

    2007-09-01T23:59:59.000Z

    Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance is straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation

  1. Applied Catalysis B: Environmental 140141 (2013) 468477 Contents lists available at SciVerse ScienceDirect

    E-Print Network [OSTI]

    Alvarez, Pedro J.

    2013-01-01T23:59:59.000Z

    Applied Catalysis B: Environmental 140­141 (2013) 468­477 Contents lists available at SciVerse ScienceDirect Applied Catalysis B: Environmental journal homepage: www

  2. Value iteration for (switched) homogeneous systems

    E-Print Network [OSTI]

    Dahleh, Munther A.

    In this note, we prove that dynamic programming value iteration converges uniformly for discrete-time homogeneous systems and continuous-time switched homogeneous systems. For discrete-time homogeneous systems, rather than ...

  3. Some General Themes in Catalysis at LANL

    SciTech Connect (OSTI)

    Gordon, John C. [Los Alamos National Laboratory

    2012-07-19T23:59:59.000Z

    Some general themes in catalysis at LANL are: (1) Storage and release of energy within chemical bonds (e.g. H{sub 2} storage in and release from covalent bonds, N{sub 2} functionalization, CO{sub 2} functionalization, H{sub 2} oxidation/evolution, O{sub 2} reduction/evolution); (2) Can we control the chemistry of reactive substrates to effect energy relevant transformations in non-traditional media (e.g. can we promote C-C couplings, dehydrations, or hydrogenations in water under relatively mild conditions)? (3) Can we supplant precious metal or rare earth catalysts to effect these transformations, by using earth abundant metals/elements instead? Can we use organocatalysis and circumvent the use of metals completely? (4) Can we improve upon existing rare earth catalyst systems (e.g. in rare earth oxides pertinent to fluid cracking or polymerization) and reduce amounts required for catalytic efficacy? Carbohydrates can be accessed from non-food based biomass sources such as woody residues and switchgrass. After extracted from the plant source, our goal is to upgrade these classes of molecules into useful fuels.

  4. E-Print Network 3.0 - alkane oxidation catalysis Sample Search...

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

    hydrogen... Reforming of Methane 10 Gas Phase Incorporation of Pd onto Iron-Ceria Aerogels for Water Gas Shift Catalysis... at the 20 North American Meeting of the Catalysis...

  5. Applied Catalysis A: General 243 (2003) 1524 On the potential role of hydroxyl groups in

    E-Print Network [OSTI]

    Marks, Laurence D.

    2003-01-01T23:59:59.000Z

    Applied Catalysis A: General 243 (2003) 15­24 On the potential role of hydroxyl groups in CO.K. Costello et al. / Applied Catalysis A: General 243 (2003) 15­24 sensitivity may also account, in part

  6. Applied Catalysis A: General 392 (2011) 5768 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Auerbach, Scott M.

    2011-01-01T23:59:59.000Z

    Applied Catalysis A: General 392 (2011) 57­68 Contents lists available at ScienceDirect Applied Catalysis A: General journal homepage: www.elsevier.com/locate/apcata Liquid phase aldol condensation

  7. GTPase Catalysis by Ras and Other G-proteins: Insights from Substrate Directed SuperImposition

    E-Print Network [OSTI]

    Kosloff, Mickey

    GTPase Catalysis by Ras and Other G-proteins: Insights from Substrate Directed Super usage of similar approaches to comparison of enzyme catalytic machineries. We applied SDSI to various G catalysis; GTPase; guanine nucleotides; conformational rearrangement; structure comparison

  8. Applied Catalysis B: Environmental 105 (2011) 5060 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Frenkel, Anatoly

    2011-01-01T23:59:59.000Z

    Applied Catalysis B: Environmental 105 (2011) 50­60 Contents lists available at ScienceDirect Applied Catalysis B: Environmental journal homepage: www.elsevier.com/locate/apcatb Cobalt

  9. This issue of Topics in Catalysis is devoted to ``Nanotechnology in Catalysis'' and covers some of the

    E-Print Network [OSTI]

    Resasco, Daniel

    silica, catalyst supports and catalytic membranes. Nanosized hollow spheres (silica or carbon) have been crystal structures, electronic configurations, or surface compositions that can only be obtained with nano of Nanotechnology. A well-known advan- tage of reducing particle size is the increase in surface area per unit

  10. active homogeneous catalyst: Topics by E-print Network

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

    of our appraoch is that it also applies to reactions among particles of finite size (so-called inertial particles). Tamas Tel; Takashi Nishikawa; Adilson E. Motter; Celso...

  11. Gold(I)-Mediated Nucleophilic Additions to Allenes: from Enantioselective Catalysis to Supramolecular Chemistry

    E-Print Network [OSTI]

    Wang, Zhan

    2012-01-01T23:59:59.000Z

    supramolecular catalysis where the capsule itself serves as a molecular reaction vessel, product can bind competitively with the starting material.

  12. Reliable computation of homogeneous azeotropes

    SciTech Connect (OSTI)

    Maier, R.W.; Brennecke, J.F.; Stadtherr, M.A. [Univ. of Notre Dame, IN (United States). Dept. of Chemical Engineering] [Univ. of Notre Dame, IN (United States). Dept. of Chemical Engineering

    1998-08-01T23:59:59.000Z

    It is important to determine the existence and composition of homogeneous azeotropes in the analysis of phase behavior and in the synthesis and design of separation systems, from both theoretical and practical standpoints. A new method for reliably locating any and all homogeneous azeotropes for multicomponent mixtures is presented. The method also verifies the nonexistence of homogeneous azeotropes if none are present. The method is based on interval analysis, in particular an interval-Newton/generalized-bisection-algorithm providing a mathematical and computational guarantee that all azeotropes are located. This general-purpose technique can be applied in connection with any thermodynamic models. The technique is illustrated in several example problems using the Wilson, NRTL, and UNIQUAC activity-coefficient models.

  13. Applied Catalysis A: General 391 (2011) 342349 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Goodman, Wayne

    2011-01-01T23:59:59.000Z

    Applied Catalysis A: General 391 (2011) 342­349 Contents lists available at ScienceDirect Applied Catalysis A: General journal homepage: www.elsevier.com/locate/apcata Preparation and characterization of Co in the last several decades due to their practical applications in many industrial areas such as catalysis

  14. Applied Catalysis B: Environmental 29 (2001) 327336 Gas-phase photo-oxidation of toluene using

    E-Print Network [OSTI]

    2001-01-01T23:59:59.000Z

    Applied Catalysis B: Environmental 29 (2001) 327­336 Gas-phase photo-oxidation of toluene using reserved. PII: S0926-3373(00)00211-3 #12;328 A.J. Maira et al. / Applied Catalysis B: Environmental 29.V. All rights reserved. Keywords: Photo-catalysis; Titanium dioxide; Nanoparticles; Volatile organic

  15. Applied Catalysis A: General 477 (2014) 102108 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Cao, Guozhong

    2014-01-01T23:59:59.000Z

    Applied Catalysis A: General 477 (2014) 102­108 Contents lists available at ScienceDirect Applied Catalysis A: General journal homepage: www.elsevier.com/locate/apcata Ordered mesoporous tungsten carbide, in particular, catalysis [21­24]. A key issue for improving this class of meso- porous structure

  16. Final technical report, Symposium on New Theoretical Concepts and Directions in Catalysis

    SciTech Connect (OSTI)

    Metiu, Horia [University of California, Santa Barbara

    2014-08-22T23:59:59.000Z

    We organized in August 2013 a “Symposium on New Theoretical Concepts and Directions in Catalysis” with the participation of 20 invited distinguished quantum chemists and other researchers who use computations to study catalysis. Symposium website; http://catalysis.cnsi.ucsb.edu/

  17. DOI: 10.1002/ijch.201100102 Single-Molecule Studies of HIV-1 Protease Catalysis

    E-Print Network [OSTI]

    Myong, Sua

    DOI: 10.1002/ijch.201100102 Single-Molecule Studies of HIV-1 Protease Catalysis Enabled by Chemical. Introduction Understanding the chemistry of enzyme catalysis has been an important objective of chemical of the chemistry occurring in the enzyme­substrate complex. The physical organic chemistry of enzyme catalysis

  18. Exhaust aftertreatment using plasma-assisted catalysis

    SciTech Connect (OSTI)

    Penetrante, B

    2000-01-20T23:59:59.000Z

    In the field of catalysis, one application that has been classified as a breakthrough technology is the catalytic reduction of NO{sub x} in oxygen-rich environments using hydrocarbons. This breakthrough will require dramatic improvements in both catalyst and engine technology, but the benefits will be substantial for energy efficiency and a cleaner environment. Engine and automobile companies are placing greater emphasis on the diesel engine because of its potential for saving fuel resources and reducing CO{sub 2} emissions. The modern direct-injection diesel engine offers demonstrated fuel economy advantages unmatched by any other commercially-viable engine. The main drawback of diesel engines is exhaust emissions. A modification of existing oxidation catalyst/engine technology is being used to address the CO, hydrocarbon and particulates. However, no satisfactory solution currently exists for NO{sub x}. Diesel engines operate under net oxidizing conditions, thus rendering conventional three-way catalytic converters ineffective for the controlling the NO{sub x} emission. NO{sub x} reduction catalysts, using ammonia as a reductant, do exist for oxygen-rich exhausts; however, for transportation applications, the use of on-board hydrocarbon fuels is a more feasible, cost-effective, and environmentally-sound approach. Selective catalytic reduction (SCR) by hydrocarbons is one of the leading catalytic aftertreatment technologies for the reduction of NO{sub x} in lean-burn engine exhaust (often referred to as lean-NO{sub x}). The objective is to chemically reduce the pollutant molecules of NO{sub x} to benign molecules such as N{sub 2}. Aftertreatment schemes have focused a great deal on the reduction of NO because the NO{sub x} in engine exhaust is composed primarily of NO. Recent studies, however, have shown that the oxidation of NO to NO{sub 2} serves an important role in enhancing the efficiency for reduction of NO{sub x} to N{sub 2}. It has become apparent that preconverting NO to NO{sub 2} could improve both the efficiency and durability of lean-NO{sub x} catalysts. A non-thermal plasma is an efficient means for selective partial oxidation of NO to NO{sub 2}. The use of a non-thermal plasma in combination with a lean-NO{sub x} catalyst opens the opportunity for catalysts that are more efficient and more durable compared to conventional catalysts. In the absence of hydrocarbons, the O radicals will oxidize NO to NO{sub 2}, and the OH radicals will further oxidize NO{sub 2} to nitric acid. In plasma-assisted catalysis it is important that the plasma oxidize NO to NO{sub 2} without further producing acids.

  19. High-Spin Cobalt Hydrides for Catalysis

    SciTech Connect (OSTI)

    Holland, Patrick L. [Yale University] [Yale University

    2013-08-29T23:59:59.000Z

    Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

  20. Catalysis-by-design impacts assessment

    SciTech Connect (OSTI)

    Fassbender, L L; Young, J K [Pacific Northwest Lab., Richland, WA (USA); Sen, R K [Sen (R.K.) and Associates, Washington, DC (USA)

    1991-05-01T23:59:59.000Z

    Catalyst researchers have always recognized the need to develop a detailed understanding of the mechanisms of catalytic processes, and have hoped that it would lead to developing a theoretical predictive base to guide the search for new catalysts. This understanding allows one to develop a set of hierarchical models, from fundamental atomic-level ab-initio models to detailed engineering simulations of reactor systems, to direct the search for optimized, efficient catalyst systems. During the last two decades, the explosions of advanced surface analysis techniques have helped considerably to develop the building blocks for understanding various catalytic reactions. An effort to couple these theoretical and experimental advances to develop a set of hierarchical models to predict the nature of catalytic materials is a program entitled Catalysis-by-Design (CRD).'' In assessing the potential impacts of CBD on US industry, the key point to remember is that the value of the program lies in developing a novel methodology to search for new catalyst systems. Industrial researchers can then use this methodology to develop proprietary catalysts. Most companies involved in catalyst R D have two types of ongoing projects. The first type, what we call market-driven R D,'' are projects that support and improve upon a company's existing product lines. Project of the second type, technology-driven R D,'' are longer term, involve the development of totally new catalysts, and are initiated through scientists' research ideas. The CBD approach will impact both types of projects. However, this analysis indicates that the near-term impacts will be on market-driven'' projects. The conclusions and recommendations presented in this report were obtained by the authors through personal interviews with individuals involved in a variety of industrial catalyst development programs and through the three CBD workshops held in the summer of 1989. 34 refs., 7 figs., 7 tabs.

  1. Homogeneous Random Measures and Strongly Supermedian Kernels

    E-Print Network [OSTI]

    Fitzsimmons, Patrick J.

    . Keywords and phrases: Homogeneous random measure, additive functional, Kuznets* *ov measure, potential

  2. Enantioselective Alkenylation of Aldehydes with Boronic Acids via the Synergistic Combination of Copper(II) and Amine Catalysis

    E-Print Network [OSTI]

    MacMillan, David W. C.

    recently applied the synergistic catalysis paradigm to the development of several new asymmetric bond of Copper(II) and Amine Catalysis Jason M. Stevens and David W. C. MacMillan* Merck Center for Catalysis combination of copper and chiral amine catalysis. The merger of two highly utilized and robust catalytic

  3. Allylation of acetanilides with allyl acetate under conditions of metal-complex catalysis combined with phase-transfer catalysis

    SciTech Connect (OSTI)

    Lebedev, S.A.; Leonova, Yu.P.; Berestova, S.S.; Petrov, E.S.

    1988-10-20T23:59:59.000Z

    Acetanilides are alkylated at the nitrogen atom under the conditions of phase-transfer catalysis. For the case of the reaction of acetanilides with allyl acetate the authors showed that 2-alkenyl esters can be used for the alkylation of acetanilides under the conditions of phase-transfer catalysis in the presence of the complexes of zero valent palladium. N-Acetylskatole was obtained with a yield of 50% from N-allyl-2-bromoacetanilide by intramolecular cyclization in the presence of Od(OAc)/sub 2/ as catalyst.

  4. Frontiers in Catalysis Science and Engineering Seminar Series

    E-Print Network [OSTI]

    in internal combustion engines and power plants. Copper-exchanged promising as selective catalytic reduction ) are a major atmospheric pollutant produced through the combustion of fossil fuels in internal combustionFrontiers in Catalysis Science and Engineering Seminar Series Small Pore Zeolites: Effective

  5. Frontiers in Catalysis Science and Engineering Seminar Series

    E-Print Network [OSTI]

    Frontiers in Catalysis Science and Engineering Seminar Series On the role of hydrogen of Chemical & Biological Engineering ·University of Wisconsin - Madison Abstract Hydrogen is a frequent principles governing the role of hydrogen in a wide range of catalytic transformations begin to emerge

  6. Overview of surface science and catalysis by Qifei Wu

    E-Print Network [OSTI]

    of hydrodesulfurization catalysis Crude oil contains S-impurity (R-S; environmental hazard) H2 + R-S RH + H2S catalyst P. Hydrodesulfurization (HDS) on metcar nanoparticles C4H4S(g) +3H2(g) C4H8(g) +H2S(g) According to our DFT calculations

  7. Lithium Diisopropylamide-Mediated Ortholithiations: Lithium Chloride Catalysis

    E-Print Network [OSTI]

    Collum, David B.

    Lithium Diisopropylamide-Mediated Ortholithiations: Lithium Chloride Catalysis Lekha Gupta, 2008 Ortholithiations of a range of arenes mediated by lithium diisopropylamide (LDA) in THF at -78 °C protocols with unpurified commercial samples of n-butyl- lithium to prepare LDA or commercially available

  8. JOURNAL OF CATALYSIS 177, 343351 (1998) ARTICLE NO. CA982143

    E-Print Network [OSTI]

    Iglesia, Enrique

    1998-01-01T23:59:59.000Z

    - modynamically favorable at high temperatures, but often leads to high yields of coke and smaller hydrocarbons, but it requires a selective catalyst in order to avoid complete oxidation to CO and CO2. A number of recentJOURNAL OF CATALYSIS 177, 343­351 (1998) ARTICLE NO. CA982143 Structure and Properties of Vanadium

  9. Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis

    SciTech Connect (OSTI)

    Behrens, Malte

    2012-03-28T23:59:59.000Z

    Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.

  10. paper topics

    E-Print Network [OSTI]

    2013-03-10T23:59:59.000Z

    The final paper must be about 10 pages long, written in Latex, and on a topic ... The topic must be chosen by March 21st, a first draft (which must be complete) is.

  11. Superization of Homogeneous Spin Manifolds and Geometry of Homogeneous Supermanifolds

    E-Print Network [OSTI]

    Andrea Santi

    2009-05-24T23:59:59.000Z

    Let M_0=G_0/H be a (pseudo)-Riemannian homogeneous spin manifold, with reductive decomposition g_0=h+m and let S(M_0) be the spin bundle defined by the spin representation Ad:H->\\GL_R(S) of the stabilizer H. This article studies the superizations of M_0, i.e. its extensions to a homogeneous supermanifold M=G/H whose sheaf of superfunctions is isomorphic to Lambda(S^*(M_0)). Here G is the Lie supergroup associated with a certain extension of the Lie algebra of symmetry g_0 to an algebra of supersymmetry g=g_0+g_1=g_0+S via the Kostant-Koszul construction. Each algebra of supersymmetry naturally determines a flat connection nabla^{S} in the spin bundle S(M_0). Killing vectors together with generalized Killing spinors (i.e. nabla^{S}-parallel spinors) are interpreted as the values of appropriate geometric symmetries of M, namely even and odd Killing fields. An explicit formula for the Killing representation of the algebra of supersymmetry is obtained, generalizing some results of Koszul. The generalized spin connection nabla^{S} defines a superconnection on M, via the super-version of a theorem of Wang.

  12. NOTE: OPTIMAL NON-HOMOGENEOUS COMPOSITES FOR ...

    E-Print Network [OSTI]

    R. Tavakoli

    2012-10-02T23:59:59.000Z

    NOTE: OPTIMAL NON-HOMOGENEOUS COMPOSITES FOR. DYNAMIC LOADING REVISITED. R. TAVAKOLI. 1. Problem formulation. Consider ? ? Rd (

  13. Molecular-Level Design of Heterogeneous Chiral Catalysis

    SciTech Connect (OSTI)

    Francisco Zaera

    2012-03-21T23:59:59.000Z

    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration, and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

  14. One- and two-dimensional infrared spectroscopic studies of solution-phase homogeneous catalysis and spin-forbidden reactions

    SciTech Connect (OSTI)

    Sawyer, Karma Rae

    2008-12-12T23:59:59.000Z

    Understanding chemical reactions requires the knowledge of the elementary steps of breaking and making bonds, and often a variety of experimental techniques are needed to achieve this goal. The initial steps occur on the femto- through picosecond time-scales, requiring the use of ultrafast spectroscopic methods, while the rate-limiting steps often occur more slowly, requiring alternative techniques. Ultrafast one and two-dimensional infrared and step-scan FTIR spectroscopies are used to investigate the photochemical reactions of four organometallic complexes. The analysis leads to a detailed understanding of mechanisms that are general in nature and may be applicable to a variety of reactions.

  15. One- and two-dimensional infrared spectroscopic studies of solution-phase homogeneous catalysis and spin-forbidden reactions

    E-Print Network [OSTI]

    Sawyer, Karma Rae

    2010-01-01T23:59:59.000Z

    Tsunami 80 MHz, 650 mW, 80 fs, 800 nm (FWHM = 13nm) Nd:YLF nanosecond pump laser SpectraPhysics Evolution-

  16. Journal of Molecular Catalysis A: Chemical 251 (2006) 823 Design and study of homogeneous catalysts for the selective,

    E-Print Network [OSTI]

    Goddard III, William A.

    2006-01-01T23:59:59.000Z

    as groups have focused on the catalytic conversion of its major component, methane, to functionalized products. The key requirements is to design new catalysts for the oxidative functionalization of methane oxidation chemistry could lead to a new paradigm in petrochemical technology that is environmentally cleaner

  17. Plasma-Activated Lean NOx Catalysis for Heavy-Duty Diesel Emissions...

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

    2002deeraardahl.pdf More Documents & Publications Heavy-Duty NOx Emissions Control: Reformer-Assisted vs. Plasma-Facilitated Lean NOx Catalysis Selective reduction of NOx in...

  18. Support for U.S. Participants at the 15th International Congress on Catalysis

    SciTech Connect (OSTI)

    Wachs, Israel E.

    2013-08-05T23:59:59.000Z

    The grant was used to partially assist the travel expenses of U.S. academic scientists to attend the 15th International Congress on Catalysis. The conference was held in Munich, Germany from July 1-6, 2012. The importance of the International Congress was to bring together the international community of faculty members who participate in catalysis research, and to share information that would lead to further developments and directions in the field of study. Graduate students and Post Docs were invited to apply for travel assistance based on criteria established by the North American Catalysis Society (NACS) and the local Catalysis Clubs.

  19. Plasma-Activated Lean NOx Catalysis for Heavy-Duty Diesel Emissions...

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

    Lean NOx Catalysis l Chemistry l Reducing Agent Effects l Collaboration with LEP CRADA l Aging Studies Plasma Initiation - + Electron Avalanche e - e - e - e - e - e - e -...

  20. A novel bifunctional catalyst for alkene isomerization : development, scope and limitations, and applications in organic transformations

    E-Print Network [OSTI]

    Larsen, Casey Renee

    2012-01-01T23:59:59.000Z

    W. A. Applied Homogenous Catalysis with OrganometallicW. A. Applied Homogenous Catalysis with OrganometallicIndustry” Applied Homogenous Catalysis with Organometallic

  1. Applied Catalysis A: General 232 (2002) 219235 An EXAFS study of the co-ordination chemistry of hydrogen

    E-Print Network [OSTI]

    Regalbuto, John R.

    2002-01-01T23:59:59.000Z

    Applied Catalysis A: General 232 (2002) 219­235 An EXAFS study of the co-ordination chemistry)00116-3 #12;220 W.A. Spieker et al. / Applied Catalysis A: General 232 (2002) 219­235 dissociation

  2. Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...

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

    Development of catalyst materials to facilitate the low-temperature oxidation of hydrocarbons and CO in homogeneous charge compression ignition (HCCI) emissions. deer08...

  3. The research at the department of Biochemistry is focused on enzyme catalysis, applied enzymology and ecological plant biochemistry. There are two main activities within enzyme catalysis, one towards synthesis

    E-Print Network [OSTI]

    Lagergren, Jens

    The research at the department of Biochemistry is focused on enzyme catalysis, applied enzymology and ecological plant biochemistry. There are two main activities within enzyme catalysis, one towards synthesis of enzyme catalysis based on a broad interdisciplinary competence in enzymology, molecular biology, organic

  4. Optimization Online - On Implementing a Homogeneous Interior ...

    E-Print Network [OSTI]

    Anders Skajaa

    2011-01-25T23:59:59.000Z

    Jan 25, 2011 ... imm.dtu.dk) Per Christian Hansen (pch ***at*** imm.dtu.dk). Abstract: Based on earlier work by Nesterov, an implementation of a homogeneous ...

  5. Removal of Toluene in Air by Non Thermal Plasma-Catalysis Hybrid , H. T. Pham

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Removal of Toluene in Air by Non Thermal Plasma-Catalysis Hybrid System A. Khacef , H. T. Pham , A Orléans Cedex 02, France * Institute of Applied Material Science, VAST, 1 Mac Dinh Chi, HCMC, Vietnam with heterogeneous catalysts. This combination can be either single-stage (in-plasma catalysis, IPC) or two

  6. Probing the chemistry of thioredoxin catalysis Arun P. Wiita1,2

    E-Print Network [OSTI]

    Fernandez, Julio M.

    LETTERS Probing the chemistry of thioredoxin catalysis with force Arun P. Wiita1,2 , Raul Perez organisms1 . Although catalysis is thought to proceed through a substitution nucleophilic bimolecular (SN2 (Trx). We applied mechanical force in the range of 25­600 pN to a disulphide bond substrate

  7. Advanced Synthesis & Catalysis Terminal alkyne metathesis: a further step towards selectivity.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Advanced Synthesis & Catalysis Terminal alkyne metathesis: a further step towards selectivity 320436585 E-mail: andre.mortreux@ensc-lille.fr , Received alkyne / metathesis / catalysis / carbyne,[2] the latter giving rise to much more active catalysts, allowing the reaction to be applied

  8. Amine a-heteroarylation via photoredox catalysis: a homolytic aromatic substitution pathway

    E-Print Network [OSTI]

    MacMillan, David W. C.

    Amine a-heteroarylation via photoredox catalysis: a homolytic aromatic substitution pathway accomplished via photoredox catalysis to generate valuable benzylic amine pharmacophores. A variety of five substitution (SNAr)3 or transi- tion metal-catalyzed approaches,4 have been extensively studied and applied

  9. Applied Catalysis A: General 226 (2002) 183192 NO reduction by urea under lean conditions

    E-Print Network [OSTI]

    Gulari, Erdogan

    2002-01-01T23:59:59.000Z

    Applied Catalysis A: General 226 (2002) 183­192 NO reduction by urea under lean conditions over.V. All rights reserved. PII: S0926-860X(01)00901-2 #12;184 E. Seker et al. / Applied Catalysis A: General

  10. Journal of Catalysis 260 (2008) 342350 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Regalbuto, John R.

    2008-01-01T23:59:59.000Z

    Journal of Catalysis 260 (2008) 342­350 Contents lists available at ScienceDirect Journal of Catalysis www.elsevier.com/locate/jcat The synthesis of highly dispersed noble and base metals on silica via The catalyst synthesis method of strong electrostatic adsorption (SEA) was applied to mesoporous silica SBA-15

  11. Journal of Catalysis 260 (2008) 329341 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Regalbuto, John R.

    2008-01-01T23:59:59.000Z

    Journal of Catalysis 260 (2008) 329­341 Contents lists available at ScienceDirect Journal of Catalysis www.elsevier.com/locate/jcat The synthesis of highly dispersed noble and base metals on silica via and after reduction. The results showed that the SEA method can be applied for many ammine complexes

  12. Z .Journal of Molecular Catalysis A: Chemical 153 2000 155163 www.elsevier.comrlocatermolcata

    E-Print Network [OSTI]

    Truong, Thanh N.

    Z .Journal of Molecular Catalysis A: Chemical 153 2000 155­163 www and Applied Chemistry, Chemistry Department, Faculty of Science, Kasetsart UniÕersity, Bangkok 10900, Thailand. q 2000 Elsevier Science B.V. All rights reserved. 1. Introduction Zeolite catalysis is of prime

  13. Bifunctional Lewis Acid-Nucleophile-Based Asymmetric Catalysis: Mechanistic Evidence for Imine Activation Working

    E-Print Network [OSTI]

    Lectka, Thomas

    Bifunctional Lewis Acid-Nucleophile-Based Asymmetric Catalysis: Mechanistic Evidence for Imine that substantial progress has been made in the use of well- defined bifunctional systems as applied to asymmetric catalysis.4 Several of these systems combine a metal ion (usually as part of a chiral Lewis acid complex

  14. Tandem Catalysis A Highly Efficient and Rapid Approach to Synthetic Elaboration

    E-Print Network [OSTI]

    Stoltz, Brian M.

    diiodide catalyzed Mukaiyama Michael-aldol reactions C.) Zirconium catalyzed synthesis of !-cyanohydrins D and rhodium catalyzed annulation. B.) Cobalt catalyzed annulation and cycloaddition C.) Rapid synthesis of pyrroles and furans D.) Organocatalytic / Lewis acid tandem catalysis 5.) Conclusions Tandem catalysis

  15. Single-molecule enzymology of RNA: Essential functional groups impact catalysis from a distance

    E-Print Network [OSTI]

    Walter, Nils G.

    Single-molecule enzymology of RNA: Essential functional groups impact catalysis from a distance the site of catalysis have on the individual rate constants. We find that all ribozyme variants show rate constants. This leads to heterogeneous cleavage activity as com- monly observed for RNA enzymes

  16. Physica A 249 (1998) 558564 Mutual catalysis in sets of prebiotic

    E-Print Network [OSTI]

    Pilpel, Yitzhak

    1998-01-01T23:59:59.000Z

    Physica A 249 (1998) 558­564 Mutual catalysis in sets of prebiotic organic molecules : Evolution on the origin of life needs to delineate a chemically rigorous, self-consistent path from highly heterogeneous Replication Domain (GARD) model for explicit kinetic analysis of mutual catalysis in sets of random oligomers

  17. AQUEOUS HOMOGENEOUS REACTORTECHNICAL PANEL REPORT

    SciTech Connect (OSTI)

    Diamond, D.J.; Bajorek, S.; Bakel, A.; Flanagan, G.; Mubayi, V.; Skarda, R.; Staudenmeier, J.; Taiwo, T.; Tonoike, K.; Tripp, C.; Wei, T.; Yarsky, P.

    2010-12-03T23:59:59.000Z

    Considerable interest has been expressed for developing a stable U.S. production capacity for medical isotopes and particularly for molybdenum- 99 (99Mo). This is motivated by recent re-ductions in production and supply worldwide. Consistent with U.S. nonproliferation objectives, any new production capability should not use highly enriched uranium fuel or targets. Conse-quently, Aqueous Homogeneous Reactors (AHRs) are under consideration for potential 99Mo production using low-enriched uranium. Although the Nuclear Regulatory Commission (NRC) has guidance to facilitate the licensing process for non-power reactors, that guidance is focused on reactors with fixed, solid fuel and hence, not applicable to an AHR. A panel was convened to study the technical issues associated with normal operation and potential transients and accidents of an AHR that might be designed for isotope production. The panel has produced the requisite AHR licensing guidance for three chapters that exist now for non-power reactor licensing: Reac-tor Description, Reactor Coolant Systems, and Accident Analysis. The guidance is in two parts for each chapter: 1) standard format and content a licensee would use and 2) the standard review plan the NRC staff would use. This guidance takes into account the unique features of an AHR such as the fuel being in solution; the fission product barriers being the vessel and attached systems; the production and release of radiolytic and fission product gases and their impact on operations and their control by a gas management system; and the movement of fuel into and out of the reactor vessel.

  18. THE KINEMATIC FORMULA IN RIEMANNIAN HOMOGENEOUS SPACES

    E-Print Network [OSTI]

    Howard, Ralph

    THE KINEMATIC FORMULA IN RIEMANNIAN HOMOGENEOUS SPACES Ralph Howard Department of Mathematics)IR (N). This generalizes the Chern-Federer kinematic formula to arbitrary homogeneous spaces with an invariant Riemannian metric and leads to new formulas even in the case of submanifolds of Euclidean space

  19. ADSORPTION OF SEMIFLEXIBLE POLYMERS ON HOMOGENEOUS SURFACES

    E-Print Network [OSTI]

    Oro, Daniel

    ADSORPTION OF SEMIFLEXIBLE POLYMERS ON HOMOGENEOUS SURFACES K. Sumithra F G Theoretische Physik the problem of adsorption of a single semiflexible polymer chain on to a planar, homogeneous surface using off-lattice Monte Carlosimulations. Adsorption characteristics were studied at different temperatures for chains

  20. Inorganic Chemistry in Hydrogen Storage and Biomass Catalysis

    SciTech Connect (OSTI)

    Thorn, David [Los Alamos National Laboratory

    2012-06-13T23:59:59.000Z

    Making or breaking C-H, B-H, C-C bonds has been at the core of catalysis for many years. Making or breaking these bonds to store or recover energy presents us with fresh challenges, including how to catalyze these transformations in molecular systems that are 'tuned' to minimize energy loss and in molecular and material systems present in biomass. This talk will discuss some challenging transformations in chemical hydrogen storage, and some aspects of the inorganic chemistry we are studying in the development of catalysts for biomass utilization.

  1. Catalysis Science | U.S. DOE Office of Science (SC)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t z C o . C lKieling ,Catalysis Science Chemical

  2. Theoretical Study on Catalysis by Protein Enzymes and Ribozyme

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in theTheoretical Study on Catalysis by Protein Enzymes

  3. Catalysis Working Group Meeting: June 2014 | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Change RequestFirstchampions, checklists,CaseyCatalysis Working

  4. Catalysis Working Group Meeting: May 2013 | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Change RequestFirstchampions, checklists,CaseyCatalysis

  5. Catalysis by Design - Theoretical and Experimental Studies of Model

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Change RequestFirstchampions, checklists,CaseyCatalysisCatalysts

  6. Catalysis | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurTheBrookhaven National Laboratory Laboratory Policy (LP) LPCMSNFScienceCatalysis

  7. A microreactor system for high-pressure, multiphase homogeneous and heterogeneous catalyst measurements under continuous flow

    E-Print Network [OSTI]

    Keybl, Jaroslav

    2011-01-01T23:59:59.000Z

    The shift towards biomass and lower quality fossil fuel feedstocks will require new conversion approaches. Catalysis will be critical in the processing of these new feedstocks. By studying catalysis at industrially relevant ...

  8. acid-assisted phosphine catalysis: Topics by E-print Network

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

    Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110 Marshall, Garland R. 37 Catalytic Hydrogenolysis of Biphenylene with Platinum, Palladium,...

  9. Producing tritium in a homogenous reactor

    DOE Patents [OSTI]

    Cawley, William E. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A method and apparatus are described for the joint production and separation of tritium. Tritium is produced in an aqueous homogenous reactor and heat from the nuclear reaction is used to distill tritium from the lower isotopes of hydrogen.

  10. a-007 topical gel: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  11. Spontaneous generation of local CP violation and inverse magnetic catalysis

    E-Print Network [OSTI]

    Lang Yu; Hao Liu; Mei Huang

    2014-09-14T23:59:59.000Z

    In the chiral symmetric phase, the polarized instanton--anti-instanton molecule pairing induces a nontrivial repulsive interaction in the iso-scalar axial-vector channel. As a consequence, one unusual property is observed that in the chiral restoration phase, there is a first order phase transition for the spontaneous generation of local CP violation and chiral imbalance. Furthermore, it is found that external magnetic fields will lower the critical temperature for the local CP-odd phase transition and catalyze the chiral imbalance, which destroys the chiral condensate with pairing quarks between different chiralities. A reasonable strength of the repulsive interaction in the iso-scalar axial-vector channel can naturally explain the inverse magnetic catalysis around the critical temperature under external magnetic fields.

  12. Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

    SciTech Connect (OSTI)

    Cutler, A. R.

    2001-04-14T23:59:59.000Z

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.

  13. Studies toward biomimetic claisen condensation using nucleic acid templates and ribozyme catalysis

    E-Print Network [OSTI]

    Ryu, Youngha

    2005-08-29T23:59:59.000Z

    Many different experimental approaches were attempted to achieve carbon-carbon bond formation by nucleic acid template-directed reactions and ribozyme catalysis as potential lipid synthesizing machineries in the RNA world. A novel biomimetic...

  14. Two-Stage Plasma-Catalysis for Diesel NOx Emission Control. ...

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

    producing nitrogen. Citation: Hoard J, and RG Tonkyn.2003."Two-Stage Plasma-Catalysis for Diesel NOx Emission Control."Journal of Advanced Oxidation Technologies 6(2):158-165....

  15. Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial

    E-Print Network [OSTI]

    Boyer, Edmond

    Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial ainsi que des exemples d'applications industrielles. Abstract -- Transformation of Sorbitol to Biofuels and biodiesel production led to first generation biofuels. Nowadays, research is focused on lignocellulosic

  16. Molecular computations for reactions and phase transitions: applications to protein stabilization, hydrates and catalysis

    E-Print Network [OSTI]

    Anderson, Brian J.

    In this work we have made significant contributions in three different areas of interest: therapeutic protein stabilization, thermodynamics of natural gas clathrate-hydrates, and zeolite catalysis. In all three fields, ...

  17. A Note on KKT Points of Homogeneous Programs 1'

    E-Print Network [OSTI]

    2005-07-11T23:59:59.000Z

    A Note on KKT Points of Homogeneous Programs 1'. Y. B. Zhao 2 and D. Li 3. Abstract. Homogeneous programming is an important class of optimization ...

  18. Analytical modeling of the interaction of enzyme catalysis and diffusion processes at the intracellular level

    E-Print Network [OSTI]

    Faith, Duane Willbern

    1977-01-01T23:59:59.000Z

    ANALYTICAL MODELING OF THE INTERACTION OF ENZYME CATALYSIS AND DIFFUSION PROCESSES AT THE INTRACELLULAR LEVEL A Thesis by Duane Nillbern Faith Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1977 Major Subject: Bioengineering ANALYTICAL MODELING OF THE INTERACTION OF ENZYME CATALYSIS AND DIFFUSION PROCESSES AT THE INTRACELLULAR LEVEL A Thesis by Duane Willbern Faith Approved as to style and content by...

  19. Studies of the relationship of protein structure to regulation and catalysis in tyrosine hydroxylase

    E-Print Network [OSTI]

    Sura, Giri Raju

    2007-09-17T23:59:59.000Z

    STUDIES OF THE RELATIONSHIP OF PROTEIN STRUCTURE TO REGULATION AND CATALYSIS IN TYROSINE HYDROXYLASE A Dissertation by GIRI RAJU SURA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2006 Major Subject: Biochemistry STUDIES OF THE RELATIONSHIP OF PROTEIN STRUCTURE TO REGULATION AND CATALYSIS IN TYROSINE HYDROXYLASE A Dissertation by GIRI RAJU...

  20. Final Report on Kokes Awards for the 20th North American Catalysis Society Meeting

    SciTech Connect (OSTI)

    Wong, Michael S

    2008-12-31T23:59:59.000Z

    This Final Report describes how the Kokes Awards program was carried out for the 2007 meeting with regard to selection of students and disbursement of funds received from DOE and other sources. The objective of the Richard J. Kokes Travel Award program of the American Catalysis Society is to encourage graduate students to attend and participate meaningfully in the biennial North American Catalysis Society Meeting.

  1. Sensitivity Analysis of Combustion Timing of Homogeneous

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    to predict the start of combustion in a homogeneous charge compression ignition (HCCI) engine. Qualitative and quantitative information on the individual effects of fuel and exhaust gas recirculation on the HCCI combustion-injection gasoline HCCI engine, we find that temperature is the dominant factor in determining the start

  2. acoustic materials: Topics by E-print Network

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

    acoustic materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 A prototype homogenization model for...

  3. Applied Catalysis A: General 192 (2000) 227234 Hydrogen production via the direct cracking of methane over Ni/SiO2

    E-Print Network [OSTI]

    zur Loye, Hans-Conrad

    2000-01-01T23:59:59.000Z

    Applied Catalysis A: General 192 (2000) 227­234 Hydrogen production via the direct cracking al. / Applied Catalysis A: General 192 (2000) 227­234 to be the diffusion of carbon through the metal

  4. Interactive Topic Modeling

    E-Print Network [OSTI]

    Pleple, Quentin

    26 Interactive LDA . . . . . . . . . . . . . . . .and B. Satinoff (2011). Interactive topic modeling. InOF CALIFORNIA, SAN DIEGO Interactive Topic Modeling A thesis

  5. On the energy of homogeneous cosmologies

    E-Print Network [OSTI]

    James M. Nester; Lau Loi So; T. Vargas

    2008-03-23T23:59:59.000Z

    An energy for the homogeneous cosmological models is presented. More specifically, using an appropriate natural prescription, we find the energy within any region with any gravitational source for a large class of gravity theories--namely those with a tetrad description--for all 9 Bianchi types. Our energy is given by the value of the Hamiltonian with homogeneous boundary conditions; this value vanishes for all regions in all Bianchi class A models, and it does not vanish for any class B model. This is so not only for Einstein's general relativity but, moreover, for the whole 3-parameter class of tetrad-teleparallel theories. For the physically favored one parameter subclass, which includes the teleparallel equivalent of Einstein's theory as an important special case, the energy for all class B models is, contrary to expectation, negative.

  6. Homogeneous Einstein metrics on SU(n)

    E-Print Network [OSTI]

    Abid H. Mujtaba

    2011-10-10T23:59:59.000Z

    It is known that every compact simple Lie group admits a bi-invariant homogeneous Einstein metric. In this paper we use two ansatz to probe the existence of additional inequivalent Einstein metrics on the Lie group SU (n) for arbitrary n. We provide an explicit construction of (2k+1) inequivalent Einstein metrics on SU (2k) and 2k inequivalent Einstein metrics on SU (2k + 1).

  7. Simulations on the effects of confinement and Ni-catalysis on the formation of tubular fullerene structures from peapod precursors

    E-Print Network [OSTI]

    Goddard III, William A.

    Simulations on the effects of confinement and Ni-catalysis on the formation of tubular fullerene April 2007 We applied the recently developed reactive force field ReaxFF to study the dynamics buckyballs. This barrier is lowered by 40% with the aid of Ni-catalysis. This research can help the community

  8. Asymmetric Catalysis on Sequentially-Linked Columns Ahmed M. Hafez, Andrew E. Taggi, Travis Dudding, and Thomas Lectka*

    E-Print Network [OSTI]

    Lectka, Thomas

    Asymmetric Catalysis on Sequentially-Linked Columns Ahmed M. Hafez, Andrew E. Taggi, Travis Dudding of a series of "reaction columns". This process was applied to the catalytic asymmetric synthesis of -lactams that they conduct chemical reactions. In regard to chiral synthesis and drug discovery, asymmetric catalysis1

  9. 2010 CATALYSIS GORDON RESEARCH CONFERENCE, JUNE 27 - JULY 2, 2010, NEW LONDON, NEW HAMPSHIRE

    SciTech Connect (OSTI)

    Abhaya Datye

    2010-07-02T23:59:59.000Z

    Catalysis is a key technology for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. The discovery of new catalytic processes and the improvement of existing ones are also critically important for securing the nation's energy supply. The GRC on Catalysis is considered one the most prestigious conference for catalysis research, bringing together leading researchers from both academia, industry and national labs to discuss the latest, most exciting research in catalysis and the future directions for the field. The 2010 GRC on Catalysis will follow time-honored traditions and feature invited talks from the world's leading experts in the fundamentals and applications of catalytic science and technology. We plan to have increased participation from industry. The extended discussions in the company of outstanding thinkers will stimulate and foster new science. The conference will include talks in the following areas: Alternative feedstocks for chemicals and fuels, Imaging and spectroscopy, Design of novel catalysts, Catalyst preparation fundamentals, Molecular insights through theory, Surface Science, Catalyst stability and dynamics. In 2010, the Catalysis conference will move to a larger conference room with a new poster session area that will allow 40 posters per session. The dorm rooms provide single and double accommodations, free WiFi and the registration fee includes all meals and the famous lobster dinner on Thursday night. Afternoons are open to enjoy the New England ambiance with opportunities for hiking, sailing, golf and tennis to create an outstanding conference that will help you network with colleagues, and make long lasting connections.

  10. Highly Dispersed Pseudo-Homogeneous and Heterogeneous Catalysts Synthesized via Inverse Micelle Solutions for the Liquefaction of Coal

    SciTech Connect (OSTI)

    Hampden-Smith, M.; Kawola, J.S.; Martino, A.; Sault, A.G.; Yamanaka, S.A.

    1999-01-05T23:59:59.000Z

    The mission of this project was to use inverse micelle solutions to synthesize nanometer sized metal particles and test the particles as catalysts in the liquefaction of coal and other related reactions. The initial focus of the project was the synthesis of iron based materials in pseudo-homogeneous form. The frost three chapters discuss the synthesis, characterization, and catalyst testing in coal liquefaction and model coal liquefaction reactions of iron based pseudo-homogeneous materials. Later, we became interested in highly dispersed catalysts for coprocessing of coal and plastic waste. Bifunctional catalysts . to hydrogenate the coal and depolymerize the plastic waste are ideal. We began studying, based on our previously devised synthesis strategies, the synthesis of heterogeneous catalysts with a bifunctional nature. In chapter 4, we discuss the fundamental principles in heterogeneous catalysis synthesis with inverse micelle solutions. In chapter 5, we extend the synthesis of chapter 4 to practical systems and use the materials in catalyst testing. Finally in chapter 6, we return to iron and coal liquefaction now studied with the heterogeneous catalysts.

  11. Growth mechanism of graphene on platinum: Surface catalysis and carbon segregation

    SciTech Connect (OSTI)

    Sun, Jie, E-mail: jie.sun@chalmers.se; Lindvall, Niclas; Yurgens, August [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Nam, Youngwoo [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Cole, Matthew T. [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, CB3 0FA Cambridge (United Kingdom); Teo, Kenneth B. K. [AIXTRON Nanoinstruments Ltd., Swavesey, CB24 4FQ Cambridge (United Kingdom); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-04-14T23:59:59.000Z

    A model of the graphene growth mechanism of chemical vapor deposition on platinum is proposed and verified by experiments. Surface catalysis and carbon segregation occur, respectively, at high and low temperatures in the process, representing the so-called balance and segregation regimes. Catalysis leads to self-limiting formation of large area monolayer graphene, whereas segregation results in multilayers, which evidently “grow from below.” By controlling kinetic factors, dominantly monolayer graphene whose high quality has been confirmed by quantum Hall measurement can be deposited on platinum with hydrogen-rich environment, quench cooling, tiny but continuous methane flow and about 1000?°C growth temperature.

  12. Gauge Theories in Noncommutative Homogeneous Kähler Manifolds

    E-Print Network [OSTI]

    Yoshiaki Maeda; Akifumi Sako; Toshiya Suzuki; Hiroshi Umetsu

    2014-09-07T23:59:59.000Z

    We construct a gauge theory on a noncommutative homogeneous K\\"ahler manifold, where we employ the deformation quantization with separation of variables for K\\"ahler manifolds formulated by Karabegov. A key point in this construction is to obtaining vector fields which act as inner derivations for the deformation quantization. We show that these vector fields are the only Killing vector fields. We give an explicit construction of this gauge theory on noncommutative ${\\mathbb C}P^N$ and noncommutative ${\\mathbb C}H^N$.

  13. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    SciTech Connect (OSTI)

    Yonghua Zhang

    2002-05-27T23:59:59.000Z

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an attractive alternative to current methods for genetic analysis and disease diagnosis.

  14. Mesoscale harmonic analysis of homogenous dislocation nucleation

    E-Print Network [OSTI]

    Asad Hasan; Craig E. Maloney

    2012-05-08T23:59:59.000Z

    We perform atomistic computer simulations to study the mechanism of homogeneous dislocation nucleation in two dimensional (2D) hexagonal crystalline films during indentation with a circular nanoindenter. The nucleation process is governed by the vanishing of the energy associated with a single normal mode. This critical mode is largely confined to a single plane of adjacent atoms. For fixed film thickness, L, the spatial extent, \\xi, of the critical mode grows with indenter radius, R. For fixed R/L, the spatial extent \\xi, grows roughly as \\xi ~ L^0.4. We, furthermore, perform a mesoscale analysis to determine the lowest energy normal mode for mesoscale regions of varying radius, r_{meso}, centered on the critical mode's core. The energy, \\lambda_{meso}, of the lowest normal mode in the meso-region decays very rapidly with r_{meso} and \\lambda_{meso} ~= 0 for r_{meso} >~ \\xi. The lowest normal mode shows a spatial extent, \\xi_{meso}, which has a sublinear power-law increase with r_{meso} for r_{meso} mesoscale analysis gives good estimates for the energy and spatial extent of the critical mode \\emph{only} for r_{meso} >~ 1.5 \\xi. In this sense homogeneous dislocation nucleation should be understood as a quasi-local phenomenon.

  15. 337th Catalysis Research Center (CRC) Colloquium Fluorine Industry in China

    E-Print Network [OSTI]

    Ishii, Hitoshi

    337th Catalysis Research Center (CRC) Colloquium Fluorine Industry in China Lu Long (Shanghai industries in China, the second largest economy in the world. In this presentation, fluorine industry in China and the potential business opportunity will be discussed briefly, including inorganic fluorides

  16. Enzyme-Like Catalysis of the Nazarov Cyclization by Supramolecular Encapsulation

    SciTech Connect (OSTI)

    Hastings, Courtney; Pluth, Michael; Bergman, Robert; Raymond, Kenneth

    2010-03-29T23:59:59.000Z

    A primary goal in the design and synthesis of molecular hosts has been the selective recognition and binding of a variety of guests using non-covalent interactions. Supramolecular catalysis, which is the application of such hosts towards catalysis, has much in common with many enzymatic reactions, chiefly the use of both spatially appropriate binding pockets and precisely oriented functional groups to recognize and activate specific substrate molecules. Although there are now many examples which demonstrate how selective encapsulation in a host cavity can enhance the reactivity of a bound guest, all have failed to reach the degree of increased reactivity typical of enzymes. We now report the catalysis of the Nazarov cyclization by a self-assembled coordination cage, a carbon-carbon bond-forming reaction which proceeds under mild, aqueous conditions. The acceleration in this system is over a million-fold, and represents the first example of supramolecular catalysis that achieves the level of rate enhancement comparable to that observed in several enzymes. We explain the unprecedented degree of rate increase as due to the combination of (a) preorganization of the encapsulated substrate molecule, (b) stabilization of the transition state of the cyclization by constrictive binding, and (c) increase in the basicity of the complexed alcohol functionality.

  17. Challenges for the application of quantum chemical calculations to problems in catalysis

    E-Print Network [OSTI]

    Bell, Alexis T.

    2004) A long-standing goal of researchers in the field of catalysis is to develop first-principles of a catalysed reaction occurring in a reactor given knowledge only of reactor configuration, catalyst accurate determinations of reactor performance given a set of rate parameters describing catalyst

  18. Enantioselective Organocatalytic Indole Alkylations. Design of a New and Highly Effective Chiral Amine for Iminium Catalysis

    E-Print Network [OSTI]

    MacMillan, David W. C.

    structural motifs of established value in medicinal chemistry or complex target synthesis. In this regard the capacity of iminium catalysis to mediate the enantioselective coupling of pyrroles and R, -unsaturated alde nucleophiles. Despite struc- tural similarities, it has long been established7 that the pyrrole -system

  19. Applied Catalysis A: General 254 (2003) 97106 Photoionization detection (PID) as a high throughput

    E-Print Network [OSTI]

    Senkan, Selim M.

    Applied Catalysis A: General 254 (2003) 97­106 Photoionization detection (PID) as a high throughput 2002 Abstract A versatile photoionization detection (PID) system has been developed to rapidly screen libraries of catalytic materials. The PID approach involves the use of an appropriately selected dc

  20. High surface area crystalline titanium dioxide: potential and limits in electrochemical energy storage and catalysis

    E-Print Network [OSTI]

    Pfeifer, Holger

    High surface area crystalline titanium dioxide: potential and limits in electrochemical energy-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany Abstract Titanium dioxide is one, as support in catalysis etc. Common synthesis methods of titanium dioxide typically require a high

  1. Argonne National Laboratory Chemical Engineering Division Water-gas shift catalysis

    E-Print Network [OSTI]

    Argonne National Laboratory Chemical Engineering Division Water-gas shift catalysis Sara Yu Choung Engineering Division Argonne National Laboratory Hydrogen, Fuel Cells, and Infrastructure Technologies 2003 Merit Review Berkeley, CA May 19-22, 2003 #12;Argonne National Laboratory Chemical Engineering Division

  2. Catalysis Today 77 (2002) 6578 CO-free fuel processing for fuel cell applications

    E-Print Network [OSTI]

    Goodman, Wayne

    2002-01-01T23:59:59.000Z

    Catalysis Today 77 (2002) 65­78 CO-free fuel processing for fuel cell applications T.V. Choudhary In view of the stringent CO intolerance of the state-of-the-art proton exchange membrane (PEM) fuel cells of hydrocarbons has been proposed for production of CO-free hydrogen for fuel cell applications. The decomposition

  3. Author's personal copy Catalysis of imido group hydrolysis in a maleimide conjugate

    E-Print Network [OSTI]

    Raines, Ronald T.

    Author's personal copy Catalysis of imido group hydrolysis in a maleimide conjugate Jeet Kaliaa, resulting in undesirable heterogeneity. Here, a chromophoric maleimide is used to demonstrate that both for molybdate and chromate, and provides a strategy for decreasing the heterogeneity of bioconjugates derived

  4. Asymmetric Catalysis at the Mesoscale: Gold Nanoclusters Embedded in Chiral Self-Assembled Monolayer as Heterogeneous

    E-Print Network [OSTI]

    Asymmetric Catalysis at the Mesoscale: Gold Nanoclusters Embedded in Chiral Self of the catalytically active metallic sites and the surrounding chiral SAM for the formation of a mesoscale the catalytically active site from the nanoscale to the mesoscale, which implies a principle of operating systems

  5. Enhancing quantum entanglement and quantum teleportation for two-mode squeezed vacuum state by local quantum-optical catalysis

    E-Print Network [OSTI]

    Xue-xiang Xu

    2015-03-17T23:59:59.000Z

    I investigate how the entanglement properties of a two-mode squeezed vacuum state (TMSVS) can be enhanced by operating quantum-optical catalysis, proposed by Lovvky and Mlynek [Phys. Rev. Lett. 88, 250404 (2002)], on each mode. I show that the degree of entanglement, the Eistein-Podolsky-Rosen-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the appropriate quantum-optical catalysis is applied to a TMSVS. It is found that all the enhancements are happened in the small-squeezing and small-catalysis parameter regime.

  6. Homogeneous catalyst formulations for methanol production

    DOE Patents [OSTI]

    Mahajan, Devinder (Port Jefferson, NY); Sapienza, Richard S. (Shoreham, NY); Slegeir, William A. (Hampton Bays, NY); O'Hare, Thomas E. (Huntington Station, NY)

    1991-02-12T23:59:59.000Z

    There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.-), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

  7. Homogeneous catalyst formulations for methanol production

    DOE Patents [OSTI]

    Mahajan, Devinder (Port Jefferson, NY); Sapienza, Richard S. (Shoreham, NY); Slegeir, William A. (Hampton Bays, NY); O'Hare, Thomas E. (Huntington Station, NY)

    1990-01-01T23:59:59.000Z

    There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.13 ), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

  8. Solvation and Acid Strength Effects on Catalysis by Faujasite Zeolites

    SciTech Connect (OSTI)

    Gounder, Rajamani P.; Jones, Andrew J.; Carr, Robert T.; Iglesia, Enrique

    2012-02-01T23:59:59.000Z

    Kinetic, spectroscopic, and chemical titration data indicate that differences in monomolecular isobutane cracking and dehydrogenation and methanol dehydration turnover rates (per H+) among FAU zeolites treated thermally with steam (H-USY) and then chemically with ammonium hexafluorosilicate (CDHUSY) predominantly reflect differences in the size and solvating properties of their supercage voids rather than differences in acid strength. The number of protons on a given sample was measured consistently by titrations with Na+, with CH3 groups via reactions of dimethyl ether, and with 2,6-di-tert-butylpyridine during methanol dehydration catalysis; these titration values were also supported by commensurate changes in acidic OH infrared band areas upon exposure to titrant molecules. The number of protons, taken as the average of the three titration methods, was significantly smaller than the number of framework Al atoms (Alf) obtained from X-ray diffraction and 27Al magic angle spinning nuclear magnetic resonance spectroscopy on H-USY (0.35 H+/Alf) and CD-HUSY (0.69 H+/Alf). These data demonstrate that the ubiquitous use of Alf sites as structural proxies for active H+ sites in zeolites can be imprecise, apparently because distorted Al structures that are not associated with acidic protons are sometimes detected as Alf sites. Monomolecular isobutane cracking and dehydrogenation rate constants, normalized non-rigorously by the number of Alf species, decreased with increasing Na+ content on both H-USY and CD-HUSY samples and became undetectable at sub-stoichiometric exchange levels (0.32 and 0.72 Na+/Alf ratios, respectively), an unexpected finding attributed incorrectly in previous studies to the presence of minority ‘‘super-acidic’’ sites. These rate constants, when normalized rigorously by the number of residual H+ sites were independent of Na+ content on both H-USY and CD-HUSY samples, reflecting the stoichiometric replacement of protons that are uniform in reactivity by Na+ cations. Monomolecular isobutane cracking and dehydrogenation rate constants (per H+; 763 K), however, were higher on H-USY than CD-HUSY (by a factor of 1.4). Equilibrium constants for the formation of protonated methanol dimers via adsorption of gaseous methanol onto adsorbed methanol monomers, determined from kinetic studies of methanol dehydration to dimethyl ether (433 K), were also higher on H-USY than CD-HUSY (by a factor of 2.1). These larger constants predominantly reflect stronger dispersive interactions in H-USY, consistent with its smaller supercage voids that result from the occlusion of void space by extraframework Al (Alex) residues. These findings appear to clarify enduring controversies about the mechanistic interpretation of the effects of Na+ and Alex species on the catalytic reactivity of FAU zeolites. They also illustrate the need to normalize rates by the number of active sites instead of more convenient but less accurate structural proxies for such sites.

  9. The roles of redox active cofactors in catalysis : structural studies of iron sulfur cluster and flavin dependent enzymes

    E-Print Network [OSTI]

    Goldman, Peter John

    2013-01-01T23:59:59.000Z

    Cofactors are highly prevalent in biological systems and have evolved to take on many functions in enzyme catalysis. Two cofactors, flavin adenine dinucleotide (FAD) and [4Fe-4S] clusters, were originally determined to aid ...

  10. Optimization Online - Note: Optimal non-homogeneous composites ...

    E-Print Network [OSTI]

    Tavakoli Rouhollah

    2012-08-29T23:59:59.000Z

    Aug 29, 2012 ... Note: Optimal non-homogeneous composites for dynamic loading revisited. Tavakoli Rouhollah (rtavakoli ***at*** sharif.ir). Abstract: The ...

  11. A Homogeneous Model for P0 and P? Nonlinear Complementarity ...

    E-Print Network [OSTI]

    2005-05-01T23:59:59.000Z

    to P0 CPs starting at a positive point near the central trajectory and does not .... the trajectory induced by the homogeneous model is discussed as an essential.

  12. Towards Realization of Computational Homogenization in Practice1

    E-Print Network [OSTI]

    Fish, Jacob

    demonstrate how to utilize ABAQUS existing facilities to develop analysis attributes required for solving homogenization technologies have been successfully verified and validated; and while industry have abandoned in

  13. Homogeneous cosmology with aggressively expanding civilizations

    E-Print Network [OSTI]

    S. Jay Olson

    2014-11-17T23:59:59.000Z

    In the context of a homogeneous universe, we note that the appearance of aggressively expanding advanced life is geometrically similar to the process of nucleation and bubble growth in a first-order cosmological phase transition. We exploit this similarity to describe the dynamics of life saturating the universe on a cosmic scale, adapting the phase transition model to incorporate probability distributions of expansion and resource consumption strategies. Through a series of numerical solutions covering several orders of magnitude in the input assumption parameters, the resulting cosmological model is used to address basic questions related to the intergalactic spreading of life, dealing with issues such as timescales, observability, competition between strategies, and first-mover advantage. Finally, we examine physical effects on the universe itself, such as reheating and the backreaction on the evolution of the scale factor, if such life is able to control and convert a significant fraction of the available pressureless matter into radiation. We conclude that the existence of life, if certain advanced technologies are practical, could have a significant influence on the future large-scale evolution of the universe.

  14. Davydov's Solitons in a Homogeneous Nucleotide Chain

    E-Print Network [OSTI]

    Lakhno, Victor D

    2013-01-01T23:59:59.000Z

    Charge transfer in homogeneous nucleotide chains is modeled on the basis of Holstein Hamiltonian. The path length of Davydov solitons in these chains is being studied. It is shown that in a dispersionless case, when the soliton velocity V is small, the path length grows exponentially as V decreases. In this case the state of a moving soliton is quasisteady. In the presence of dispersion determined by the dependence $\\Omega^2 = \\Omega_0^2 + V_0^2\\kappa^2$ \\, the path length in the region 0 V_0 the soliton motion is accompanied by emission of phonons which leads to a finite path length of a soliton. The latter tends to infinity as $V \\rightarrow V_0 + 0$ and $V \\rightarrow \\infty$. The presence of dissipation leads to a finite soliton path length. An equilibrium velocity of soliton in an external electric field is calculated. It is shown that there is a maximum intensity of an electric field at which a steady motion of a soliton is possible. The soliton mobility is calculated for the stable or ohmic brunch.

  15. Charge Transfer and Support Effects in Heterogeneous Catalysis

    SciTech Connect (OSTI)

    Hervier, Antoine

    2011-12-21T23:59:59.000Z

    The kinetic, electronic and spectroscopic properties of two?dimensional oxide?supported catalysts were investigated in order to understand the role of charge transfer in catalysis. Pt/TiO{sub 2} nanodiodes were fabricated and used as catalysts for hydrogen oxidation. During the reaction, the current through the diode, as well as its I?V curve, were monitored, while gas chromatography was used to measure the reaction rate. The current and the turnover rate were found to have the same temperature dependence, indicating that hydrogen oxidation leads to the non?adiabatic excitation of electrons in Pt. A fraction of these electrons have enough energy to ballistically transport through Pt and overcome the Schottky barrier at the interface with TiO{sub 2}. The yield for this phenomenon is on the order of 10{sup ?4} electrons per product molecule formed, similar to what has been observed for CO oxidation and for the adsorption of many different molecules. The same Pt/TiO{sub 2} system was used to compare currents in hydrogen oxidation and deuterium oxidation. The current through the diode under deuterium oxidation was found to be greater than under hydrogen oxidation by a factor of three. Weighted by the difference in turnover frequencies for the two isotopes, this would imply a chemicurrent yield 5 times greater for D{sub 2} compared to H{sub 2}, contrary to what is expected given the higher mass of D{sub 2}. Reversible changes in the rectification factor of the diode are observed when switching between D{sub 2} and H{sub 2}. These changes are a likely cause for the differences in current between the two isotopes. In the nanodiode experiments, surface chemistry leads to charge flow, suggesting the possibility of creating charge flow to tune surface chemistry. This was done first by exposing a Pt/Si diode to visible light while using it as a catalyst for H{sub 2} oxidation. Absorption of the light in the Si, combined with the band bending at the interface, gives rise to a steady?state flow of hot holes to the surface. This leads to a decrease in turnover on the surface, an effect which is enhanced when a reverse bias is applied to the diode. Similar experiments were carried out for CO oxidation. On Pt/Si diodes, the reaction rate was found to increase when a forward bias was applied. When the diode was exposed to visible light and a reverse bias was applied, the rate was instead decreased. This implies that a flow of negative charges to the surface increases turnover, while positive charges decrease it. Charge flow in an oxide supported metal catalyst can be modified even without designing the catalyst as a solid state electronic device. This was done by doping stoichiometric and nonstoichiometric TiO{sub 2} films with F, and using the resulting oxides as supports for Pt films. In the case of stoichiometric TiO{sub 2}, F was found to act as an n?type dopant, creating a population of filled electronic states just below the conduction band, and dramatically increasing the conductivity of the oxide film. The electrons in those states can transfer to surface O, activating it for reaction with CO, and leading to increased turnover for CO oxidation. This reinforces the hypothesis that CO oxidation is activated by a flow of negative charges to the surface. The same set of catalysts was used for methanol oxidation. The electronic properties of the TiO{sub 2} films again correlated with the turnover rates, but also with selectivity. With stoichiometric TiO{sub 2} as the support, F?doping caused an increase in selectivity toward the formation of partial oxidation products, formaldehyde and methyl formate, versus the total oxidation product, CO{sub 2}. With non?stoichiometric TiO{sub 2}, F?doping had the reverse effect. Ambient Pressure X?Ray Photoelectron Spectroscopy was used to investigate this F?doping effect in reaction conditions. In O2 alone, and in CO oxidation conditions, the O1s spectrum showed a high binding energy peak that correlated in intensity with the activity of the different films: for stoichiomet

  16. On the role of interfacial hydrogen bonds in "on-water" catalysis

    E-Print Network [OSTI]

    Kristof Karhan; Rustam Z. Khaliullin; Thomas D. Kühne

    2014-08-21T23:59:59.000Z

    Numerous experiments have demonstrated that many classes of organic reactions exhibit increased reaction rates when performed in heterogeneous water emulsions. Despite enormous practical importance of the observed "on-water" catalytic effect and several mechanistic studies, its microscopic origins remains unclear. In this work, the second generation Car-Parrinello molecular dynamics method is extended to self-consistent charge density-functional based tight-binding in order to study "on-water" catalysis of the Diels-Alder reaction between dimethyl azodicarboxylate and quadricyclane. We find that the stabilization of the transition state by dangling hydrogen bonds exposed at the aqueous interfaces plays a significantly smaller role in "on-water" catalysis than has been suggested previously.

  17. Kokes Awards for the 22nd North American Catalysis Society Meeting, June 5-10, 2011

    SciTech Connect (OSTI)

    Fabio H. Ribeiro

    2011-06-05T23:59:59.000Z

    The biennial North American Catalysis Society (NACS) Meetings are the premiere conferences in the area of catalysis, surface science, and reaction engineering. The 22nd meeting will be held the week of June 5-10, 2011 in Detroit, Michigan. The objective of the Meetings is to bring together leading researchers for intensive scientific exchange and interactions. Financial support that offsets some of the associated costs (specifically, registration fee, airline tickets, and hotel accommodations) would encourage graduate students, and for the first time undergraduate students, to attend and participate meaningfully in this conference. The funds sought in this proposal will help support the Richard J. Kokes Travel Award program. Graduate students eligible for these merit-based Awards are those who study at a North American university and who will present at the Meeting. We have currently 209 applications and we expect to be able to fund about half of them. The NACS has traditionally sought to encourage graduate student, and this year for the first time undergraduate studies, participation at the National Meetings and providing financial support is the most effective means to do so. Their attendance would contribute significantly to their scientific training and communication and presentation skills. They would be exposed to the leading researchers from the US and abroad; they would meet their peers from other universities; they would learn about cutting-edge results that could benefit their research projects; and they may become interested in becoming active participants in the catalysis community. These young investigators represent the next generation of scientists and engineers, and their proper training will lead to future scientific breakthroughs and technological innovations that benefit the US economy. Advances in catalysis can come in the form of more energy-efficient and environmentally-friendly chemical processes, improved fuel cell performance, efficient hydrogen production, and a cleaner environment.

  18. Joint Center for Artificial Photosynthesis

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

    Catalysis molecular catalysis The Molecular Catalysis Project involves directed discovery of homogeneous catalysts for the key reactions involved in solar-fuel generation:...

  19. MODELING OF NATURALLY FRACTURED RESERVOIRS BY FORMAL HOMOGENIZATION TECHNIQUES*

    E-Print Network [OSTI]

    Douglas Jr., Jim

    MODELING OF NATURALLY FRACTURED RESERVOIRS BY FORMAL HOMOGENIZATION TECHNIQUES* Todd Arbogast,y Jim in naturally fractured reservoirs. A single component in a single phase and two-component mis- cible. porous medium, double porosity, fractured reservoir, homogenization. yDepartment of Mathematics, Purdue

  20. At tank Low Activity Feed Homogeneity Analysis Verification

    SciTech Connect (OSTI)

    DOUGLAS, J.G.

    2000-09-28T23:59:59.000Z

    This report evaluates the merit of selecting sodium, aluminum, and cesium-137 as analytes to indicate homogeneity of soluble species in low-activity waste (LAW) feed and recommends possible analytes and physical properties that could serve as rapid screening indicators for LAW feed homogeneity. The three analytes are adequate as screening indicators of soluble species homogeneity for tank waste when a mixing pump is used to thoroughly mix the waste in the waste feed staging tank and when all dissolved species are present at concentrations well below their solubility limits. If either of these conditions is violated, then the three indicators may not be sufficiently chemically representative of other waste constituents to reliably indicate homogeneity in the feed supernatant. Additional homogeneity indicators that should be considered are anions such as fluoride, sulfate, and phosphate, total organic carbon/total inorganic carbon, and total alpha to estimate the transuranic species. Physical property measurements such as gamma profiling, conductivity, specific gravity, and total suspended solids are recommended as possible at-tank methods for indicating homogeneity. Indicators of LAW feed homogeneity are needed to reduce the U.S. Department of Energy, Office of River Protection (ORP) Program's contractual risk by assuring that the waste feed is within the contractual composition and can be supplied to the waste treatment plant within the schedule requirements.

  1. Hydrogen storage materials and method of making by dry homogenation

    DOE Patents [OSTI]

    Jensen, Craig M. (Kailua, HI); Zidan, Ragaiy A. (Honolulu, HI)

    2002-01-01T23:59:59.000Z

    Dry homogenized metal hydrides, in particular aluminum hydride compounds, as a material for reversible hydrogen storage is provided. The reversible hydrogen storage material comprises a dry homogenized material having transition metal catalytic sites on a metal aluminum hydride compound, or mixtures of metal aluminum hydride compounds. A method of making such reversible hydrogen storage materials by dry doping is also provided and comprises the steps of dry homogenizing metal hydrides by mechanical mixing, such as be crushing or ball milling a powder, of a metal aluminum hydride with a transition metal catalyst. In another aspect of the invention, a method of powering a vehicle apparatus with the reversible hydrogen storage material is provided.

  2. Selected Topics in Column Generation

    E-Print Network [OSTI]

    2002-12-02T23:59:59.000Z

    Dec 2, 2002 ... Page 1. Selected Topics in Column Generation. Marco E. Lübbecke ... is an ever recurring concept in our “selected topics.” OR/MS Subject ...

  3. Fuel effects in homogeneous charge compression ignition (HCCI) engines

    E-Print Network [OSTI]

    Angelos, John P. (John Phillip)

    2009-01-01T23:59:59.000Z

    Homogenous-charge, compression-ignition (HCCI) combustion is a new method of burning fuel in internal combustion (IC) engines. In an HCCI engine, the fuel and air are premixed prior to combustion, like in a spark-ignition ...

  4. Tritium Technology Program TTP-1-3089 TPBAR Homogenized Composition

    SciTech Connect (OSTI)

    Love, Edward F.

    2014-10-12T23:59:59.000Z

    Homogenized TPBAR number densities contained herein have been derived for unclassified core physics calculations. The use of this information may not provide accurate, conservative or representative results and must be evaluated for applicability to the specific problem.

  5. Continuum Electrodynamics of a Piecewise-Homogeneous Linear Medium

    E-Print Network [OSTI]

    Crenshaw, Michael E

    2015-01-01T23:59:59.000Z

    The energy--momentum tensor and the tensor continuity equation serve as the conservation laws of energy, linear momentum, and angular momentum for a continuous flow. Previously, we derived equations of motion for macroscopic electromagnetic fields in a homogeneous linear dielectric medium that is draped with a gradient-index antireflection coating (J. Math Phys. 55, 042901 (2014) ). These results are consistent with the electromagnetic tensor continuity equation in the limit that reflections and the accompanying surface forces are negligible thereby satisfying the condition of an unimpeded flow in a thermodynamically closed system. Here, we take the next step and derive equations of motion for the macroscopic fields in the limiting case of a piecewise-homogeneous simple linear dielectric medium. The presence of radiation surface forces on the interface between two different homogeneous linear materials means that the energy--momentum formalism must be modified to treat separate homogeneous media in which the ...

  6. Synthesis of Proteins with Homogenous Chemical and Posttranslational Modifications

    E-Print Network [OSTI]

    Wu, Bo

    2014-06-19T23:59:59.000Z

    Genetic encoding non-canonical amino acids (NCAAs) is a facile approach to synthesize proteins with homogenous modifications. In my graduate study, I demonstrated the application of this approach in the synthesis of a variety of proteins with site...

  7. Dynamics of empty homogeneous isotropic three-dimensional spaces

    E-Print Network [OSTI]

    A. V. Klimenko; V. A. Klimenko

    2012-02-28T23:59:59.000Z

    It is shown that there are seven types of solutions described in the framework of general relativity theory (GRT), the dynamics of empty homogeneous isotropic three-dimensional spaces. Solution of the equations of GRT, which describes the dynamics of a homogeneous isotropic universe, in the limiting case of vanishingly small effect of matter on the metric properties of space must go to one of them.

  8. A study of non-homogeneous absorbing Markov chains

    E-Print Network [OSTI]

    Bean, John Kevin

    1975-01-01T23:59:59.000Z

    A STUDY OF NON-HOMOGENEOUS ABSORBING MARKOV CHAINS A Thesis by JOHN KEVIN BEAN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement. ior the degree of MASTER OF SCIFNCE December 1975 Major... Subject: Mathematics A STUDY OF NON-HOMOGENEOUS ABSORBING MARKOV CHAINS A Thesis by JOHN KEVIN BEAN Approved as to style and content by: (C airman of Committee) (Head of Department) , '-. ! ember) em er December 1975 ABSTRACT A Study of Non...

  9. Theoretical/Computational Tools for Energy-Relevant Catalysis | The Ames

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in theTheoretical Study on Catalysis by

  10. Homogeneous blue pattern: A rare presentation in an acral congenital melanocytic nevus

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    Malvehy J. Homogeneous blue pattern in an acral congenitalof a plantar combined blue nevus: a simulator of melanoma.Homogeneous blue pattern: A rare presentation in an acral

  11. Proton Mediated Chemistry and Catalysis in a Self-Assembled Supramolecular Host

    SciTech Connect (OSTI)

    Pluth, Michael; Bergman, Robert; Raymond, Kenneth

    2009-04-10T23:59:59.000Z

    Synthetic supramolecular host assemblies can impart unique reactivity to encapsulated guest molecules. Synthetic host molecules have been developed to carry out complex reactions within their cavities, despite the fact that they lack the type of specifically tailored functional groups normally located in the analogous active sites of enzymes. Over the past decade, the Raymond group has developed a series of self-assembled supramolecules and the Bergman group has developed and studied a number of catalytic transformations. In this Account, we detail recent collaborative work between these two groups, focusing on chemical catalysis stemming from the encapsulation of protonated guests and expanding to acid catalysis in basic solution. We initially investigated the ability of a water-soluble, self-assembled supramolecular host molecule to encapsulate protonated guests in its hydrophobic core. Our study of encapsulated protonated amines revealed rich host-guest chemistry. We established that self-exchange (that is, in-out guest movement) rates of protonated amines were dependent on the steric bulk of the amine rather than its basicity. The host molecule has purely rotational tetrahedral (T) symmetry, so guests with geminal N-methyl groups (and their attendant mirror plane) were effectively desymmetrized; this allowed for the observation and quantification of the barriers for nitrogen inversion followed by bond rotation. Furthermore, small nitrogen heterocycles, such as N-alkylaziridines, N-alkylazetidines, and N-alkylpyrrolidines, were found to be encapsulated as proton-bound homodimers or homotrimers. We further investigated the thermodynamic stabilization of protonated amines, showing that encapsulation makes the amines more basic in the cavity. Encapsulation raises the effective basicity of protonated amines by up to 4.5 pK{sub a} units, a difference almost as large as that between the moderate and strong bases carbonate and hydroxide. The thermodynamic stabilization of protonated guests was translated into chemical catalysis by taking advantage of the potential for accelerating reactions that take place via positively charged transition states, which could be potentially stabilized by encapsulation. Orthoformates, generally stable in neutral or basic solution, were found to be suitable substrates for catalytic hydrolysis by the assembly. Orthoformates small enough to undergo encapsulation were readily hydrolyzed by the assembly in basic solution, with rate acceleration factors up to 3900 compared with those of the corresponding uncatalyzed reactions. Furthering the analogy to enzymes that obey Michaelis-Menten kinetics, we observed competitive inhibition with the inhibitor NPr{sub 4}{sup +}, thereby confirming that the interior cavity of the assembly was the active site for catalysis. Mechanistic studies revealed that the assembly is required for catalysis and that the rate-limiting step of the reaction involves proton transfer from hydronium to the encapsulated substrate. Encapsulation in the assembly changes the orthoformate hydrolysis from an A-1 mechanism (in which decomposition of the protonated substrate is the rate-limiting step) to an A-S{sub E}2 mechanism (in which proton transfer is the rate-limiting step). The study of hydrolysis in the assembly was next extended to acetals, which were also catalytically hydrolyzed by the assembly in basic solution. Acetal hydrolysis changed from the A-1 mechanism in solution to an A-2 mechanism inside the assembly, where attack of water on the protonated substrate is rate limiting. This work provides rare examples of assembly-catalyzed reactions that proceed with substantial rate accelerations despite the absence of functional groups in the cavity and with mechanisms fully elucidated by quantitative kinetic studies.

  12. Exam # 2 Topics 9.

    E-Print Network [OSTI]

    1910-61-10T23:59:59.000Z

    Page 1. MA 341 - Fall 2006. Exam # 2 Topics. 1. Convergence of a sequence; Squeeze Theorem (Exercise 2.3.3.); Zipper Theorem (Exercise. 2.3.5.); Algebraic

  13. General basic and coordination catalysis in reactions of haloaromatic compounds with ammonia in the presence of copper(I) compounds

    SciTech Connect (OSTI)

    Chumak, V.T.; Shein, S.M.

    1985-11-01T23:59:59.000Z

    This paper presents a study made to detect general basic catalysis by ammonia (reagent) in reactions of ammonolysis of haloaromatic compounds in the presence of Cu/sup +/ ions, as well as to determine the generality of the mechanisms of the catalytic replacement of a halogen atom by an amino group in the anthraquinone and benzene series.

  14. Effects of catalysis on particle motion in plane-parallel and cylindrical channels in a catalytic reactor

    SciTech Connect (OSTI)

    Kabanov, A.N.; Murashkevich, F.I.; Shulimanova, Z.L.; Shukin, E.R.

    1987-09-01T23:59:59.000Z

    A theoretical study is made on aerosol behavior in a catalysis zone for a plane-parallel or cylindrical channel in a catalytic reactor. It is found that the thermophoretic trapping coefficient may attain 10-15% in a laminar flow having longitudinal Pe and Re >> 1 even for small relative temperature differences.

  15. Decarboxylative Arylation of Amino Acids via Photoredox Catalysis: A One-Step Conversion of Biomass to Drug

    E-Print Network [OSTI]

    MacMillan, David W. C.

    Decarboxylative Arylation of Amino Acids via Photoredox Catalysis: A One-Step Conversion of Biomass. This method offers rapid entry to prevalent benzylic amine architectures from an abundant biomass the worldwide abundance of biomass6 that incorporates carboxylate functionality (e.g., amino acids, -hydroxy

  16. Approved Module Information for CH3010, 2014/5 Module Title/Name: Catalysis Module Code: CH3010

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for CH3010, 2014/5 Module Title/Name: Catalysis Module Code: CH3010 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 in which available: BSc/MChem Applied Chemistry. BSc/MChem Chemistry. BEng/MEng Chemical Engineering. MEng

  17. Structure of Human Epoxide Hydrolase Reveals Mechanistic Inferences on Bifunctional Catalysis in Epoxide and Phosphate Ester Hydrolysis,

    E-Print Network [OSTI]

    Hammock, Bruce D.

    is unclear. Recent experiments demonstrate that the N-terminal domain of human sEH catalyzes the metalStructure of Human Epoxide Hydrolase Reveals Mechanistic Inferences on Bifunctional Catalysis ReceiVed February 4, 2004 ABSTRACT: The X-ray crystal structure of human soluble epoxide hydrolase (s

  18. Applied Catalysis A: General 219 (2001) 215222 Structural analysis of unpromoted Fe-based FischerTropsch

    E-Print Network [OSTI]

    Iglesia, Enrique

    2001-01-01T23:59:59.000Z

    Applied Catalysis A: General 219 (2001) 215­222 Structural analysis of unpromoted Fe-based Fischer­Tropsch by Mössbauer emission and X-ray absorption spectroscopies after use in the Fischer­Tropsch synthesis (FTS reactant mixture. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Fischer­Tropsch synthesis; X

  19. Variable valve timing in a homogenous charge compression ignition engine

    DOE Patents [OSTI]

    Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

    2004-08-03T23:59:59.000Z

    The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

  20. Defining Least Community as a Homogeneous Group in Complex Networks

    E-Print Network [OSTI]

    Jiang, Bin

    2015-01-01T23:59:59.000Z

    This paper introduces a new concept of least community that is as homogeneous as a random graph, and develops a new community detection algorithm from the perspective of homogeneity or heterogeneity. Based on this concept, we adopt head/tail breaks - a newly developed classification scheme for data with a heavy-tailed distribution - and rely on edge betweenness given its heavy-tailed distribution to iteratively partition a network into many heterogeneous and homogeneous communities. Surprisingly, the derived communities for any self-organized and/or self-evolved large networks demonstrate very striking power laws, implying that there are far more small communities than large ones. This notion of far more small things than large ones constitutes a new fundamental way of thinking for community detection. Keywords: head/tail breaks, ht-index, scaling, k-means, natural breaks, and classification

  1. Cryogenic homogenization and sampling of heterogeneous multi-phase feedstock

    DOE Patents [OSTI]

    Doyle, Glenn Michael (Lakewood, CO); Ideker, Virgene Linda (Arvada, CO); Siegwarth, James David (Boulder, CO)

    2002-01-01T23:59:59.000Z

    An apparatus and process for producing a homogeneous analytical sample from a heterogenous feedstock by: providing the mixed feedstock, reducing the temperature of the feedstock to a temperature below a critical temperature, reducing the size of the feedstock components, blending the reduced size feedstock to form a homogeneous mixture; and obtaining a representative sample of the homogeneous mixture. The size reduction and blending steps are performed at temperatures below the critical temperature in order to retain organic compounds in the form of solvents, oils, or liquids that may be adsorbed onto or absorbed into the solid components of the mixture, while also improving the efficiency of the size reduction. Preferably, the critical temperature is less than 77 K (-196.degree. C.). Further, with the process of this invention the representative sample may be maintained below the critical temperature until being analyzed.

  2. Design, Synthesis and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    SciTech Connect (OSTI)

    Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

    2007-03-31T23:59:59.000Z

    This project extends previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have shown unprecedented Fischer-Tropsch synthesis rates and selectivities for synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic results previously reported. During the second reporting period, we prepared several Fe-based compositions for Fischer-Tropsch Synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. During the third and fourth reporting periods, we improved the catalysts preparation method, which led to Fe-based materials with the highest FTS reaction rates and selectivities so far reported, a finding that allowed their operation at lower temperatures and pressures with high selectivity to desired products (C{sub 5+}, olefins). During the fifth and sixth reporting period, we studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influenced the performance of these materials in the Fischer-Tropsch synthesis. We also continued our studies of the kinetic behavior of these materials during the sixth reporting period. Specifically, the effects of H{sub 2}, CO, and CO{sub 2} on the rates and selectivities of Fischer-Tropsch Synthesis reactions led us to propose a new sequence of elementary steps on Fe and Co Fischer-Tropsch catalysts. Finally, we also started a study of the use of colloidal precipitation methods for the synthesis small Co clusters using recently developed methods to explore possible further improvements in FTS rates and selectivities. We found that colloidal synthesis makes possible the preparation of small cobalt particles, although large amount of cobalt silicate species, which are difficult to reduce, were formed. During this seventh reporting period, we have explored several methods to modify the silanol groups on SiO{sub 2} by using either a homogeneous deposition-precipitation method or surface titration of Si-OH on SiO{sub 2} with zirconium (IV) ethoxide to prevent the formation of unreducible and unreactive CoO{sub x} species during synthesis and FTS catalysis. We have synthesized monometallic Co/ZrO{sub 2}/SiO{sub 2} catalysts with different Co loadings (11-20 wt%) by incipient wetness impregnation methods and characterized the prepared Co supported catalysts by H{sub 2} temperature-programmed reduction (H{sub 2}-TPR) and H{sub 2}-chemisorption. We have measured the catalytic performance in FTS reactions and shown that although the hydroxyl groups on the SiO{sub 2} surface are difficult to be fully titrated by ZrO{sub 2}, modification of ZrO{sub 2} on SiO{sub 2} surface can improve the Co clusters dispersion and lead to a larger number of exposed Co surface atoms after reduction and during FTS reactions. During this seventh reporting period, we have also advanced our development of the reaction mechanism proposed in the previous reporting period. Specifically, we have shown that our novel proposal for the pathways involved in CO activation on Fe and Co catalysts is consistent with state-of-the-art theoretical calculations carried out in collaboration with Prof. Manos Mavrikakis (University of Wisconsin-Madison). Finally, we have also worked on the preparation of several manuscripts describing our findings about the preparation, activation and mechanism of the FTS with Fe-based catalysts and we have started redacting the final report for this project.

  3. MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN

    E-Print Network [OSTI]

    Pielke, Roger A.

    MESOSCALE MODELLING OF WIND ENERGY OVER NON-HOMOGENEOUS TERRAIN (ReviewArticle) Y. MAHRER.1. OBSERVATIONALAPPROACHES Evaluations of wind energy based on wind observations (usually surface winds) at well, the resolution of the wind energy pattern throughout an extended area by this methodology requires a large number

  4. Homogenized Maxwell's Equations; a Model for Varistor Ceramics

    E-Print Network [OSTI]

    Birnir, Björn

    from [3] of the electric field as a function of the current density for Zinc Oxide, ZnHomogenized Maxwell's Equations; a Model for Varistor Ceramics Bj¨orn Birnir Niklas Wellander and lower bounds are obtained for the effective conductivity in the varistor. These two bounds

  5. Homogenized Maxwell's Equations; a Model for Varistor Ceramics

    E-Print Network [OSTI]

    Birnir, Björn

    from [3] of the electric field as a function of the current density for Zinc Oxide, ZnHomogenized Maxwell's Equations; a Model for Varistor Ceramics BjË? orn Birnir Niklas Wellander and lower bounds are obtained for the effective conductivity in the varistor. These two bounds

  6. Anisotropic Homogeneous Cosmologies in the Post-Newtonian Approximation

    E-Print Network [OSTI]

    Tamath Rainsford

    2000-07-23T23:59:59.000Z

    In this paper we explore how far the post-Newtonian theory goes in overcoming the difficulties associated with anisotropic homogeneous cosmologies in the Newtonian approximation. It will be shown that, unlike in the Newtonian case, the cosmological equations of the post-Newtonian approximation are much more in the spirit of general relativity with regard to the nine Bianchi types and issues of singularities. The situations of vanishing rotation and vanishing shear are treated separately. The homogeneous Bianchi I model is considered as an example of a rotation-free cosmology with anisotropy. It is found in the Newtonian approximation that there are arbitrary functions that need to be given for all time if the initial value problem is to be well-posed, while in the post-Newtonian case there is no such need. For the general case of a perfect fluid only the post-Newtonian theory can satisfactorily describe the effects of pressure. This is in accordance with findings in an earlier paper where the post-Newtonian approximation was applied to homogeneous cosmologies. For a shear-free anisotropic homogeneous cosmology the Newtonian theory of Heckmann and Sch\\"ucking is explored. Comparisons with its relativistic and post-Newtonian counterparts are made. In the Newtonian theory solutions exist to which there are no analogues in general relativity. The post-Newtonian approximation may provide a way out.

  7. CODIMENSION 2 CYCLES ON PRODUCTS OF PROJECTIVE HOMOGENEOUS SURFACES

    E-Print Network [OSTI]

    * *ary field F reduces to computing its torsion subgroup. For codimension d 1, the Chow group CH d provide general bounds for the torsion* * in the codi- mension 2 Chow groups of the products of projective homogeneous surfaces* *. In particular, we determine the torsion for the product of four

  8. Preparation of Lead Zirconate by Homogeneous Precipitation and Calcination

    E-Print Network [OSTI]

    Tas, A. Cuneyt

    Preparation of Lead Zirconate by Homogeneous Precipitation and Calcination Ersin Emre Oren, Ercan. Introduction LEAD ZIRCONATE (PbZrO3) is an antiferroelectric ceramic with a Curie temperature of 230°C electric field to the ceramic in the antifer- roelectric state) leads to significant energy storage

  9. Correlation between homogeneous propane pyrolysis and pyrocarbon deposition

    E-Print Network [OSTI]

    Boyer, Edmond

    Correlation between homogeneous propane pyrolysis and pyrocarbon deposition C´edric Descamps, G propane pyrolysis is studied in a 1-D hot-wall CVD furnace. The gas-phase pyrolysis is modelled in previous reports [6]: total pressure equal to 2 kPa, temperature between 900 K and 1400 K, and pure propane

  10. Homogenization of the criticality spectral equation in neutron transport

    E-Print Network [OSTI]

    Bal, Guillaume

    for the neutron transport equation in a periodic heterogeneous domain, modeling the criticality study of nuclearHomogenization of the criticality spectral equation in neutron transport Gr'egoire Allaire \\Lambda problem. This result justifies and improves the engineering procedure used in practice for nuclear reactor

  11. Lifetime Benefits through Load Balancing in Homogeneous Sensor Networks

    E-Print Network [OSTI]

    Haenggi, Martin

    , battery depletion is emulated so that it becomes possible to actually measure the load balancingLifetime Benefits through Load Balancing in Homogeneous Sensor Networks Daniele Puccinelli network. The use of load balancing schemes can be expected to provide significant lifetime benefits

  12. Homogeneous Charge Compression Ignition: Formulation Effect of a Diesel Fuel

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Homogeneous Charge Compression Ignition: Formulation Effect of a Diesel Fuel on the Initiation and the Combustion Potential of Olefin Impact in a Diesel Base Fuel D. Alseda1,2, X. Montagne1 and P. Dagaut2 1 Compression Ignition: Formulation Effect of a Diesel Fuel on the Initiation and the Combustion - Potential

  13. Asymmetry of rotational catalysis of single membrane-bound F0F1-ATP synthase

    E-Print Network [OSTI]

    Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael

    2007-01-01T23:59:59.000Z

    Synthesis of the cellular 'energy currency' ATP is catalyzed by membrane-bound F0F1-ATP synthases. The chemical reaction at three binding sites in the F1 part is coupled to proton translocation through the membrane-integrated F0 part by an internal rotation of subunits. We examined the rotary movements of the epsilon-subunit of the 'rotor' with respect to the b-subunits of the 'stator' by single-molecule fluorescence resonance energy transfer (FRET). Rotation of epsilon during ATP hydrolysis is divided into three major steps with constant FRET level corresponding to three binding sites. Different catalytic activities of the individual binding sites were observed depending on the relative orientation of the 'rotor'. Computer simulations of the FRET signals and non-equally distributed orientations of epsilon strongly corroborate asymmetry of catalysis in F0F1-ATP synthase.

  14. Methane Oxidation to Methanol without CO2 Emission: Catalysis by Atomic Negative Ions

    E-Print Network [OSTI]

    Tesfamichael, Aron; Felfli, Zineb; Msezane, Alfred Z

    2014-01-01T23:59:59.000Z

    The catalytic activities of the atomic Y-, Ru-, At-, In-, Pd-, Ag-, Pt-, and Os- ions have been investigated theoretically using the atomic Au- ion as the benchmark for the selective partial oxidation of methane to methanol without CO2 emission. Dispersion-corrected density-functional theory has been used for the investigation. From the energy barrier calculations and the thermodynamics of the reactions, we conclude that the catalytic effect of the atomic Ag-, At-, Ru-, and Os- ions is higher than that of the atomic Au- ion catalysis of CH4 conversion to methanol. By controlling the temperature around 290K (Os-), 300K (Ag-), 310K (At-), 320K (Ru-) and 325K (Au-) methane can be completely oxidized to methanol without the emission of CO2. We conclude by recommending the investigation of the catalytic activities of combinations of the above negative ions for significant enhancement of the selective partial oxidation of methane to methanol.

  15. Superacid catalysis of light hydrocarbon conversion. Sixth quarterly report, January 1, 1995--March 31, 1995

    SciTech Connect (OSTI)

    Gates, B.C. [California Univ., Davis, CA (United States). Dept. of Chemical Engineering and Materials Science

    1995-08-01T23:59:59.000Z

    Iron- and Manganese-promoted sulfated zirconia is a catalyst for the conversion of propane, but the rate of conversion of propane is much less than the rate of conversion of butane. Whereas this catalyst appears to be a good candidate for practical, industrial conversion of butane, it appears to lack sufficient activity for practical conversion of propane. Perhaps more active catalysts will be useful for propane conversion. The propane conversion data reported here provide excellent insights into the chemistry of the catalytic conversions; they are consistent with the inference that the catalyst is a superacid and that the chemistry is analogous to. that determined in superacid solutions by G.A. Olah, who was awarded the most recent Nobel Prize in chemistry for his work. The catalyst was tested for conversion of propane at 1 bar, 200--300{degrees}C and propane partial pressures in the range of 0.01--0.05 bar. At 250{degrees}C, catalysis was demonstrated, as the number of propane molecules converted was at least 1 per sulfate group after 16 days of operation in a continues flow reactor. Propane was converted in high yield to butanes, but the conversions were low, for example being only a fraction of a percent at a space velocity of 9.1 {times} 10{sup {minus}7} mol(g of catalysis {center_dot} s) and 250{degrees}C. Coke formation was rapid. The observation of butanes, pentanes, and methane as products is consistent with Olah superacid chemistry, whereby propane is first protonated by a very strong acid to form a carbonium ion. The carbonium ion then decomposes into methane and an ethyl cation which undergoes oligocondensation reactions with propane to form higher molecular weight alkanes. The results are consistent with the identification of iron- and manganese-promoted sulfated zirconia as a superacid.

  16. architecture as topic: Topics by E-print Network

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

    architecture as topic First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Topic 1: Internet Architecture &...

  17. Collaboration Topics - Visualization | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Simulation and Computing and Institutional R&D Programs NNSACEA Cooperation in Computer Science Collaboration Topics - Visualization Collaboration Topics - Visualization...

  18. active stabilizer tyloxapol: Topics by E-print Network

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

    screened for compounds containing the pharmacophore. Forty-seven compounds resulted from Marshall, Garland R. 48 Nano-Catalysis: Fibrous morphology makes the difference in...

  19. activation monitoring solution: Topics by E-print Network

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

    of catalysis (Vmax). The protocol used to measure viscosity by means of a falling ball type viscometer is described, together with the determination of enzyme kinetics and the...

  20. allopurinol gel mitigates: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  1. aloe vera gel: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  2. active du sol: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  3. aluminum hydroxide gel: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  4. alginate gel beads: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  5. active polar gels: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  6. aux sols pollues: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  7. agarose gel electrophoresis: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  8. agarose gel electrophoretic: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  9. agar gel immunodiffusion: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  10. al sol sobre: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  11. acetate isobutyrate gels: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  12. acc synthase expression: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 202 expression? Environments...

  13. acetolactate synthase activity: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 33 Pharmacological inhibitors...

  14. atp dependent chromatin: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 64 Regulation of...

  15. acid anew insights: Topics by E-print Network

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

    is the sequence of amino acids produced, and because amino acids average about Texas at San Antonio, University of 290 Combined Acid Catalysis for Asymmetric Synthesis Chemistry...

  16. airfoil characteristics synthesization: Topics by E-print Network

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

    an amino acid representation ... de la Maza, Michael 1993-05-01 166 Mechanochemistry for Solid-State Syntheses and Catalysis. Open Access Theses and Dissertations Summary:...

  17. TECHNICAL STANDARDS PROGRAM TOPICAL COMMITTEES

    Broader source: Energy.gov [DOE]

    PurposeThis procedure describes how topical committees are organized and recognized under the Technical Standards Program. 

  18. innovative research fa l l 2 0 0 6

    E-Print Network [OSTI]

    New Mexico, University of

    on the editorial boards of Applied Catalysis A, Catalysis Letters, Topics in Catalysis and Catalysis Communications of reactants. Catalysis playsakeyroleintheglobaleconomy,account- ing for 90% of manufacturing processes in the catalysis community. His seminal work in catalyst imaging has helped moved catalysis from an empirically

  19. Multiscale asymptotic homogenization analysis of thermo-diffusive composite materials

    E-Print Network [OSTI]

    A. Bacigalupo; L. Morini; A. Piccolroaz

    2015-03-31T23:59:59.000Z

    In this paper an asymptotic homogenization method for the analysis of composite materials with periodic microstructure in presence of thermodiffusion is described. Appropriate down-scaling relations correlating the microscopic fields to the macroscopic displacements, temperature and mass concentration are introduced. The effects of the material inhomogeneities are described by perturbation functions derived from the solution of recursive cell problems. Exact expressions for the overall elastic and thermodiffusive constants of the equivalent first order thermodiffusive continuum are derived. The proposed approach is applied to the case of a two-dimensional bi-phase orthotropic layered material, where the effective elastic and thermodiffusive properties can be determined analytically. Considering this illustrative example and assuming periodic body forces, heat and mass sources acting on the medium, the solution performed by the first order homogenization approach is compared with the numerical results obtained by the heterogeneous model.

  20. Centrifugal cosmological repulsive force in a homogeneous universe

    E-Print Network [OSTI]

    A. V. Klimenko; V. A. Klimenko

    2011-03-21T23:59:59.000Z

    We study the dynamics of homogeneous isotropic three-dimensional worlds filled with radiation (3R-worlds). It is shown that the dynamics of these worlds with the additional fourth large-scale spatial dimension leads to an important effect. At 3R-worlds the forces of repulsion appear. The source of these forces is the thermal energy of the radiation that fills these worlds. In the four-dimensional space, these forces are centrifugal. They operate in an external for 3R-world spatial dimension and stretch it. In the three-dimensional comoving coordinate system the centrifugal forces shows themselves as forces of repulsion. Standard Einstein's equations do not describe these forces. Written generalized Einstein's equation describing the dynamics of a homogeneous isotropic universe, taking into consideration the centrifugal forces of repulsion. We propose a cosmological model of the universe, based on these equations. This model apply to explain the observation data.

  1. Apparatus for unilateral generation of a homogeneous magnetic field

    DOE Patents [OSTI]

    Fukushima, E.; Rath, A.R.; Roeder, S.B.W.

    1984-05-01T23:59:59.000Z

    An apparatus for unilaterally producing a substantially homogeneous magnetic field. The apparatus includes two circular electromagnet coils, a small coil and a large coil, which are coaxial with one another and which are separated by a distance equal to one-half the difference in the radius of the two coils. By appropriate selection of electrical currents, which are passed through the coils in opposite directions, a region of homogeneous magnetic field is formed. This region is centered on the common axis of the two coils, at a point on the axis which is at a distance from the small coil equal to one-half the radius of the small coil, and which is on the opposite side of the small coil from the large coil. The apparatus has particular application in the field of diagnostic medical NMR and other NMR applications.

  2. Apparatus for unilateral generation of a homogeneous magnetic field

    DOE Patents [OSTI]

    Fukushima, Eiichi (Los Alamos, NM); Rath, Alan R. (San Diego, CA); Roeder, Stephen B. W. (La Mesa, CA)

    1988-01-01T23:59:59.000Z

    An apparatus for unilaterally producing a substantially homogeneous magnetic field. The apparatus includes two circular electromagnet coils, a small coil and a large coil, which are coaxial with one another and which are separated by a distance equal to one-half the difference in the radius of the two coils. By appropriate selection of electrical currents, which are passed through the coil in opposite directions, a region of homogeneous magnetic field is formed. This region is centered on the common axis of the two coils, at a point on the axis which is at a distance from the small coil equal to one-half the radius of the small coil, and which is on the opposite side of the small coil from the large coil. The apparatus has particular application in the field of diagnostic medical NMR and other NMR applications.

  3. High load operation in a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Liechty, Michael P. (Chillicothe, IL); Hardy, William L. (Peoria, IL); Rodman, Anthony (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL)

    2008-12-23T23:59:59.000Z

    A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

  4. Dosimetry in Mammography: Average Glandular Dose Based on Homogeneous Phantom

    SciTech Connect (OSTI)

    Benevides, Luis A. [Naval Sea Systems Command,1333 Isaac Hull Avenue, Washington Navy Yard, DC 20376 (United States); Hintenlang, David E. [University of Florida, 202 Nuclear Sciences Center, P.O. Box 1183, Gainesville Florida 32611 (United States)

    2011-05-05T23:59:59.000Z

    The objective of this study was to demonstrate that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 and 46 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. The clinical dosimetry protocol developed in this study can reliably predict the AGD imparted to an individual patient during a routine screening mammogram.

  5. Mesoporous Silica Nanomaterials for Applications in Catalysis, Sensing, Drug Delivery and Gene Transfection

    SciTech Connect (OSTI)

    Daniela Rodica Radu

    2005-12-19T23:59:59.000Z

    The central theme of this dissertation is represented by the versatility of mesoporous silica nanomaterials in various applications such as catalysis and bio-applications, with main focus on biological applications of Mesoporous Silica Nanospheres (MSN). The metamorphosis that we impose to these materials from catalysis to sensing and to drug and gene delivery is detailed in this dissertation. First, we developed a synthetic method that can fine tune the amount of chemically accessible organic functional groups on the pores surface of MSN by exploiting electrostatic and size matching between the cationic alkylammonium head group of the cetyltrimethylammonium bromide (CTAB) surfactant and various anionic organoalkoxysilane precursors at the micelle-water interface in a base-catalyzed condensation reaction of silicate. Aiming nature imitation, we demonstrated the catalytic abilities of the MSNs, We utilized an ethylenediamine functional group for chelating Cu{sup 2+} as a catalytic functional group anchored inside the mesopores. Thus, a polyalkynylene-based conducting polymer (molecular wire) was synthesized within the Cu-functionalized MSNs silica catalyst. For sensing applications, we have synthesized a poly(lactic acid) coated mesoporous silica nanosphere (PLA-MSN) material that serves as a fluorescence sensor system for detection of amino-containing neurotransmitters in neutral aqueous buffer. We exploited the mesoporosity of MSNs for encapsulating pharmaceutical drugs. We examined bio-friendly capping molecules such as polyamidoamine dendrimers of generations G2 to G4, to prevent the drug leaching. Next, the drug delivery system employed MSNs loaded with Doxorubicin, an anticancer drug. The results demonstrated that these nano-Trojan horses have ability to deliver Doxorubicin to cancer cells and induce their death. Finally, to demonstrate the potential of MSN as an universal cellular transmembrane nanovehicle, we anchored positively charged dendrimers on the surface of MSN and utilize them to complex cationic DNA. The p-EGFP-CI gene-coated MSN nanocomposite was able to transfect cancer cell lines, such as human HeLa and CHO cancer cell lines. The gene carrier ability of MSNs was further proved by transfecting primary cells and cotransfecting of two different genes in cancer cell lines. In sum, MSN are versatile partners in several types of applications.

  6. Probing the Impact of the EchinT C-Terminal Domain on Structure and Catalysis

    SciTech Connect (OSTI)

    S Bardaweel; J Pace; T Chou; V Cody; C Wagner

    2011-12-31T23:59:59.000Z

    Histidine triad nucleotide binding protein (Hint) is considered as the ancestor of the histidine triad protein superfamily and is highly conserved from bacteria to humans. Prokaryote genomes, including a wide array of both Gram-negative bacteria and Gram-positive bacteria, typically encode one Hint gene. The cellular function of Hint and the rationale for its evolutionary conservation in bacteria have remained a mystery. Despite its ubiquity and high sequence similarity to eukaryote Hint1 [Escherichia coli Hint (echinT) is 48% identical with human Hint1], prokaryote Hint has been reported in only a few studies. Here we report the first conformational information on the full-length N-terminal and C-terminal residues of Hint from the E. coli complex with GMP. Structural analysis of the echinT-GMP complex reveals that it crystallizes in the monoclinic space group P2{sub 1} with four homodimers in the asymmetric unit. Analysis of electron density for both the N-terminal residues and the C-terminal residues of the echinT-GMP complex indicates that the loops in some monomers can adopt more than one conformation. The observation of conformational flexibility in terminal loop regions could explain the presence of multiple homodimers in the asymmetric unit of this structure. To explore the impact of the echinT C-terminus on protein structure and catalysis, we conducted a series of catalytic radiolabeling and kinetic experiments on the C-terminal deletion mutants of echinT. In this study, we show that sequential deletion of the C-terminus likely has no effect on homodimerization and a modest effect on the secondary structure of echinT. However, we observed a significant impact on the folding structure, as reflected by a significant lowering of the T{sub m} value. Kinetic analysis reveals that the C-terminal deletion mutants are within an order of magnitude less efficient in catalysis compared to wild type, while the overall kinetic mechanism that proceeds through a fast step, followed by a rate-limiting hydrolysis step, was conserved. Nevertheless, the ability of the C-terminal deletion mutants to hydrolyze lysyl-AMP generated by LysU was greatly impaired. Taken together, our results highlight the emerging role of the C-terminus in governing the catalytic function of Hints.

  7. Homogenized dynamic constitutive relation for Bloch-wave propagation in periodic composites: structure and symmetries

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Homogenized dynamic constitutive relation for Bloch-wave propagation in periodic composites composites has been made only very recently. Here we discuss the explicit form of the effective dynamic properties of composites with tailored microstructure necessitates a systematic homogenization procedure

  8. assessment topics thermal: Topics by E-print Network

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

    they are meaningful. We Pratt, Vaughan 2 ENVE 569 ENVIRONMENTAL RISK ASSESSMENT TOPIC SYLLABUS Environmental Sciences and Ecology Websites Summary: ENVE 569 - ENVIRONMENTAL RISK...

  9. adaptation research topics: Topics by E-print Network

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

    RoomMEMORANDUM Current Topics in Accounting Research Students January 19, 2011 The syllabus. This is a course offering primarily designed for Accounting and Accounting...

  10. ans topical meeting: Topics by E-print Network

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

    automated (comput... Sandip Sen 1996-01-01 12 International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) N13P1395 Kanazawa City, Ishikawa Prefecture, Japan,...

  11. administration topical: Topics by E-print Network

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

    presented on topics as diverse as materials degredation in low Earth orbit, the Martian environment and several aspects of the still commercially dominant geostationary orbit. A...

  12. automatic topic indexing: Topics by E-print Network

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

    subject headings in libraries, as keywords in academic publications and as tags on the web. Knowing a documents topics helps people judge its relevance quickly. However,...

  13. Weak law of large numbers for some Markov chains along non homogeneous genealogies

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Weak law of large numbers for some Markov chains along non homogeneous genealogies Vincent Bansaye goes to infinity. It is described by a discrete genealogy which may be time non-homogeneous and we pay of the trait of each individual along this genealogy and may also be time non- homogeneous. Such models

  14. Homogenization in non linear dynamics due to frictional contact Peillex G. a

    E-Print Network [OSTI]

    Boyer, Edmond

    homogenization process and its influence on the behavior of a composite under non linear dynamic loading due homogenization process, coupled with an homogenization of the frictional contact, enables replacing the entire in the heterogeneous models are identified by using the relocalization process and a frictional contact dynamic

  15. Introduction and Case Studies The Ratio Plot Under Homogeneity and the Decontaminated Turing

    E-Print Network [OSTI]

    Boehning, Dankmar

    Outline Introduction and Case Studies The Ratio Plot Under Homogeneity and the Decontaminated Introduction and Case Studies The Ratio Plot Under Homogeneity and the Decontaminated Turing The Ratio Plot The Ratio Plot Under Homogeneity and the Decontaminated Turing The Ratio Plot and Structured Heterogeneity

  16. Self-sustained oscillations in homogeneous shear flow

    E-Print Network [OSTI]

    Victor Yakhot

    2002-06-27T23:59:59.000Z

    Generation of the large-scale coherent vortical structurs in homogeneous shear flow couples dynamical processes of energy and enstrophy production. In the large rate of strain limit, the simple estimates of the contributions to the energy and enstrophy equations result in a dynamical system, describing experimentally and numerically observed self-sustained non-linear oscillations of energy and enstrophy. It is shown that the period of these oscilaltions is independent upon the box size and the energy and enstrophy fluctuations are strongly correlated.

  17. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL)

    2008-05-27T23:59:59.000Z

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  18. Controlling And Operating Homogeneous Charge Compression Ignition (Hcci) Engines

    DOE Patents [OSTI]

    Flowers, Daniel L. (San Leandro, CA)

    2005-08-02T23:59:59.000Z

    A Homogeneous Charge Compression Ignition (HCCI) engine system includes an engine that produces exhaust gas. A vaporization means vaporizes fuel for the engine an air induction means provides air for the engine. An exhaust gas recirculation means recirculates the exhaust gas. A blending means blends the vaporized fuel, the exhaust gas, and the air. An induction means inducts the blended vaporized fuel, exhaust gas, and air into the engine. A control means controls the blending of the vaporized fuel, the exhaust gas, and the air and for controls the inducting the blended vaporized fuel, exhaust gas, and air into the engine.

  19. Synergistic Catalysis between Pd and Fe in Gas Phase Hydrodeoxygenation of m-Cresol

    SciTech Connect (OSTI)

    Hong, Yongchun; Zhang, He; Sun, Junming; Karim, Ayman M.; Hensley, Alyssa; Gu, Meng; Engelhard, Mark H.; McEwen, Jean-Sabin; Wang, Yong

    2014-10-31T23:59:59.000Z

    In this work, a series of Pd/Fe2O3 catalysts were synthesized, characterized, and evaluated for the hydrodeoxygenation (HDO) of m-cresol. It was found that the addition of Pd remarkably promotes the catalytic activity of Fe while the product distributions resemble that of monometallic Fe catalyst, showing high selectivity towards the production of toluene (C-O cleavage without saturation of aromatic ring and C-C cleavage). Reduced catalysts featured with Pd patches on the top of reduced Fe nanoparticle surface, and the interaction between Pd and Fe was further confirmed using X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM) and X-ray absorption near edge fine structure (XANES). A possible mechanism, including Pd assisted H2 dissociation and Pd facilitated stabilization of metallic Fe surface as well as Pd enhanced product desorption, is proposed to be responsible for the high activity and HDO selectivity in Pd-Fe catalysts. The synergic catalysis derived from Pd-Fe interaction found in this work was proved to be applicable to other precious metal promoted Fe catalysts, providing a promising strategy for future design of highly active and selective HDO catalysts.

  20. Catalysis Center for Energy Innovation for Biomass Processing: Research Strategies and Goals

    SciTech Connect (OSTI)

    Vlachos, Dion G.; Chen, Jingguang; Gorte, R. J.; Huber, George W.; Tsapatsis, Michael

    2010-01-01T23:59:59.000Z

    Production of energy and chemicals from biomass is of critical importance in meeting some of the challenges associated with decreasing availability of fossil fuels and addressing global climate change. In the current article, we outline a perspective on key challenges of biomass processing. We also introduce the Catalysis Center for Energy Innovation (CCEI), one of the 46 Energy Frontier Research Centers established by the Department of Energy in the spring of 2009, and CCEI’s overall research strategies and goals along with its cross-cutting research thrusts that can enable potential technological breakthroughs in the utilization of biomass and its derivatives. The center focuses on developing innovative heterogeneous catalysts and processing schemes that can lead to viable biorefineries for the conversion of biomass to chemicals, fuels, and electricity. In order to achieve this goal, a group of over twenty faculty members from nine institutions has been assembled to bring together complementary expertise covering novel materials synthesis, advanced characterization, multiscale modeling, surface science, catalytic kinetics, and microreactors.

  1. Steam catalysis in CaO carbonation under low steam partial pressure

    SciTech Connect (OSTI)

    Yang, S.J.; Xiao, Y.H. [Chinese Academy of Science, Beijing (China)

    2008-06-15T23:59:59.000Z

    CaO was widely used to capture CO{sub 2} in direct hydrogen production process, where steam always existed simultaneously. The effect of steam on CaO carbonation performance under low steam partial pressure was investigated using a pressurized thermogravimetric apparatus. The experimental results revealed that steam improved CaO carbonation performance significantly no matter whether Ca(OH){sub 2} was produced or not. At 823 K and 0.5 MPa of steam partial pressure, effect of steam on CaO carbonation performance could not be attributed mainly to production of Ca(OH){sub 2} because the hydration rate of CaO was very slow. The main reason was steam catalysis in CaO carbonation. Enhancement of steam on CaO carbonation performance without Ca(OH){sub 2} production could not be attributed to improvement of steam on the physical property, but to catalytic effect of steam. Effects of CaO precursors, CO{sub 2} partial pressure, steam partial pressure, and temperature with steam addition on CaO carbonation performance were also investigated.

  2. Molecular Insights into Substrate Recognition and Catalysis by Tryptophan 2,3-dioxygenase

    SciTech Connect (OSTI)

    Forouhar,F.; Ross Anderson, J.; Mowat, C.; Vorobiev, S.; Hussain, A.; Abashidze, M.; Bruckmann, C.; Thackray, S.; Seetharaman, J.; et al.

    2007-01-01T23:59:59.000Z

    Tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO) constitute an important, yet relatively poorly understood, family of heme-containing enzymes. Here, we report extensive structural and biochemical studies of the Xanthomonas campestris TDO and a related protein SO4414 from Shewanella oneidensis, including the structure at 1.6-{angstrom} resolution of the catalytically active, ferrous form of TDO in a binary complex with the substrate l-Trp. The carboxylate and ammonium moieties of tryptophan are recognized by electrostatic and hydrogen-bonding interactions with the enzyme and a propionate group of the heme, thus defining the l-stereospecificity. A second, possibly allosteric, l-Trp-binding site is present at the tetramer interface. The sixth coordination site of the heme-iron is vacant, providing a dioxygen-binding site that would also involve interactions with the ammonium moiety of l-Trp and the amide nitrogen of a glycine residue. The indole ring is positioned correctly for oxygenation at the C2 and C3 atoms. The active site is fully formed only in the binary complex, and biochemical experiments confirm this induced-fit behavior of the enzyme. The active site is completely devoid of water during catalysis, which is supported by our electrochemical studies showing significant stabilization of the enzyme upon substrate binding.

  3. Topics for letter "s" | EMSL

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

    Development Lab Quiet Wing RadEMSL Virtual Tour Topics for letter "s" samples scale scanning scanning electron microscope scanning probe scanning tunneling microscopy...

  4. Topics for letter "W" | EMSL

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

    Virtual Tour Topics for letter "W" W-band pulsed EPR spectrometer Washington State Academy of Sciences Washington State University waste storage water water cycling Wiley Wiley...

  5. Topics for letter "p" | EMSL

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

    Wing RadEMSL Virtual Tour Topics for letter "p" particles patents physics plants pollution polymers pore scale postdoc postdocs postdoctoral Postdoctoral Opportunities...

  6. absorption system topical: Topics by E-print Network

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

    absorption system topical First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 INFORMATION SYSTEMS UNIT...

  7. UNIRIB: Physics Topics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening aTurbulence may bedieselsummer gasoline price0 -Physics Topics

  8. Collaboration Topics - Acceleration Hardware and APIs | National...

    National Nuclear Security Administration (NNSA)

    Simulation and Computing and Institutional R&D Programs NNSACEA Cooperation in Computer Science Collaboration Topics - Acceleration Hardware and APIs Collaboration Topics...

  9. Collaboration Topics - Meshing | National Nuclear Security Administrat...

    National Nuclear Security Administration (NNSA)

    Simulation and Computing and Institutional R&D Programs NNSACEA Cooperation in Computer Science Collaboration Topics - Meshing Collaboration Topics - Meshing This work...

  10. ONE-DIMENSIONAL PSEUDO-HOMOGENEOUS PACKED BED REACTOR MODELING INCLUDING NO-CO KINETICS

    E-Print Network [OSTI]

    Srinivasan, Anand

    2011-08-31T23:59:59.000Z

    major way to meet these low standards is to employ exhaust aftertreatment devices using heterogeneous catalysis for chemical species conversion. This is because the temperature is too low and the residence time is too short for chemical reactions... the chemical reactions happening on the surface of the washcoat. Moreover, collaborative efforts investigating chemical kinetics for exhaust aftertreatment between the Mechanical (ME) and Chemical and Petroleum Engineering (CPE) Departments...

  11. Markov Topic Models Chong Wang

    E-Print Network [OSTI]

    Blei, David M.

    . For example, papers from different scien- tific conferences and journals can be viewed as a collection the correlations of different cor- pora. MTMs capture both the internal topic structure within each corpus collection. Probabilistic topic models Part of this work was done when Chong Wang was an intern at Microsoft

  12. Competing contact processes on homogeneous networks with tunable clusterization

    E-Print Network [OSTI]

    Rybak, Marcin

    2012-01-01T23:59:59.000Z

    We investigate two homogeneous networks: the Watts-Strogatz network and the random Erdos-Renyi network, the latter with tunable clustering coefficient $C$. The network is an area of two competing contact processes, where nodes can be in two states, S or D. A node S becomes D with probability 1 if at least two its mutually linked neighbours are D. A node D becomes S with a given probability $p$ if at least one of its neighbours is S. The competition between the processes is described by a phase diagram, where the critical probability $p_c$ depends on the clustering coefficient $C$. For $p>p_c$ the rate of state S increases in time, seemingly to dominate in the whole system. Below $p_c$, the contribution of D-nodes remains finite. The numerical results, supported by mean field approach, indicate that the transition is discontinuous.

  13. Applications of Fourier analysis in homogenization and boundary layer

    E-Print Network [OSTI]

    Aleksanyan, Hayk; Sjölin, Per

    2012-01-01T23:59:59.000Z

    In this paper we prove convergence results for the boundary layer homogenization problem for solutions of partial differential system with rapidly oscillating Dirichlet data. Our method is based on analysis of oscillatory integrals. In the uniformly convex regime and smooth boundaries we prove pointwise as well as $L^p$ convergence results. Namely, we prove $|u_{\\e}(x)-u_0 (x)| \\leq C_{\\kappa} \\e^{(d-1)/2}\\frac{1}{d(x)^{\\kappa}}$, $\\forall x\\in D$, $ \\forall \\ \\kappa>d-1$, and for $1\\leq pboundary of $D$. In particular for $p=2$ our result relates to the recent result of D. G\\'{e}rarad-Varet and N. Masmoudi \\cite{GM}.

  14. The manufacture and performance of homogeneous microstructure SBR MOX fuel

    SciTech Connect (OSTI)

    Barker, Matthew A. [Nexia Solutions Ltd., British Technology Centre, Sellafield, CA20 1PG (United Kingdom); Stephenson, Keith; Weston, Rebecca [Sellafield Ltd., B582, Sellafield, CA20 1PG (United Kingdom)

    2007-07-01T23:59:59.000Z

    In the early 1980's, British experience in the manufacture of mixed-oxide fast reactor fuel was used to develop a new thermal MOX manufacturing route called the Short Binder-less Route (SBR). Laboratory- scale development led to the manufacture of commercial PWR fuel in a small pilot plant, and the construction of the full-scale dual-line Sellafield MOX Plant (SMP). SMP's first MOX assemblies are now under irradiation. SBR MOX is manufactured with 100% co-milled feedstock, leading to a microstructure dominated by a solid solution of (U,Pu)O{sub 2} at the nominal enrichment. A comprehensive fuel performance research programme has demonstrated the benign performance of SBR MOX up to 54 MWd/kgHM. In particular, the homogeneous microstructure is believed to be instrumental in the favourable fission gas retention and PCI resistance properties. (authors)

  15. Rotation Rate of Particle Pairs in Homogeneous Isotropic Turbulence

    E-Print Network [OSTI]

    Daddi-Moussa-Ider, Abdallah

    2015-01-01T23:59:59.000Z

    Understanding the dynamics of particles in turbulent flow is important in many environmental and industrial applications. In this paper, the statistics of particle pair orientation is numerically studied in homogeneous isotropic turbulent flow, with Taylor microscale Rynolds number of 300. It is shown that the Kolmogorov scaling fails to predict the observed probability density functions (PDFs) of the pair rotation rate and the higher order moments accurately. Therefore, a multifractal formalism is derived in order to include the intermittent behavior that is neglected in the Kolmogorov picture. The PDFs of finding the pairs at a given angular velocity for small relative separations, reveals extreme events with stretched tails and high kurtosis values. Additionally, The PDFs are found to be less intermittent and follow a complementary error function distribution for larger separations.

  16. Generalized quantum gravity condensates for homogeneous geometries and cosmology

    E-Print Network [OSTI]

    Daniele Oriti; Daniele Pranzetti; James P. Ryan; Lorenzo Sindoni

    2015-01-05T23:59:59.000Z

    We construct a generalized class of quantum gravity condensate states, that allows the description of continuum homogeneous quantum geometries within the full theory. They are based on similar ideas already applied to extract effective cosmological dynamics from the group field theory formalism, and thus also from loop quantum gravity. However, they represent an improvement over the simplest condensates used in the literature, in that they are defined by an infinite superposition of graph-based states encoding in a precise way the topology of the spatial manifold. The construction is based on the definition of refinement operators on spin network states, written in a second quantized language. The construction lends itself easily to be applied also to the case of spherically symmetric quantum geometries.

  17. Structural, Spectroscopic, And Theoretical Elucidation of a Redox-Active Pincer-Type Ancillary Applied in Catalysis

    SciTech Connect (OSTI)

    Adhikari, D.; Mossin, S.; Basuli, F.; Huffman, J.C.; Szilagyi, R.K.; Meyer, K.; Mindiola, D.J.

    2009-05-11T23:59:59.000Z

    Pincer-type ligands are believed to be very robust scaffolds that can support multifarious functionalities as well as highly reactive metal motifs applied in organometallic chemistry, especially in the realm of catalysis. In this paper, we describe the redox and, therefore, noninnocent behavior of a PNP (PNP{sup -} = N[2-P(CHMe{sub 2}){sub 2}-4-methylphenyl]{sub 2}) pincer ancillary bound to nickel. A combination of structural, spectroscopic, and theoretical techniques suggests that this type of framework can house an electron hole when coordinated to Ni(II).

  18. Correlated Topic Models David M. Blei

    E-Print Network [OSTI]

    (CTM), where the topic proportions exhibit correlation via the logistic normal distribution [1]. We extracting the topical structure of large document collections. In technical terms, a topic model in the collection; the topic proportions are document-specific and randomly drawn from a Dirichlet distribution. LDA

  19. applications topical meeting: Topics by E-print Network

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

    the ... Fox, Harold, 1979- 2004-01-01 17 International Topical Meeting on Nuclear Reactor Thermal -Hydraulics, NURETH-15 NURETH15-491 Pisa, Italy, May 12-17, 2013 Fission and...

  20. Hydrovinylation of Norbornene. Ligand-Dependent Selectivity and

    E-Print Network [OSTI]

    RajanBabu, T. V. "Babu"

    . W.; Wilke, G. Hydrovinylation. In Applied Homogeneous Catalysis with Organometallic Compounds, J.; Kuhn, H. Preparation of Optically ActiVe Azaphospholenes and Their Use in Catalysis

  1. Numerical homogenization of concrete microstructures without explicit meshes

    SciTech Connect (OSTI)

    Sanahuja, Julien, E-mail: julien.sanahuja@edf.fr; Toulemonde, Charles, E-mail: charles.toulemonde@edf.fr

    2011-12-15T23:59:59.000Z

    Life management of electric hydro or nuclear power plants requires to estimate long-term concrete properties on facilities, for obvious safety and serviceability reasons. Decades-old structures are foreseen to be operational for several more decades. As a large number of different concrete formulations are found in EDF facilities, empirical models based on many experiments cannot be an option for a large fleet of power plant buildings. To build predictive models, homogenization techniques offer an appealing alternative. To properly upscale creep, especially at long term, a rather precise description of the microstructure is required. However, the complexity of the morphology of concrete poses several challenges. In particular, concrete is formulated to maximize the packing density of the granular skeleton, leading to aggregates spanning several length scales with small inter particle spacings. Thus, explicit meshing of realistic concrete microstructures is either out of reach of current meshing algorithms or would produce a number of degrees of freedom far higher than the current generic FEM codes capabilities. This paper proposes a method to deal with complex matrix-inclusions microstructures such as the ones encountered at the mortar or concrete scales, without explicitly meshing them. The microstructure is superimposed to an independent mesh, which is a regular Cartesian grid. This inevitably yields so called 'gray elements', spanning across multiple phases. As the reliability of the estimate of the effective properties highly depends on the behavior affected to these gray elements, special attention is paid to them. As far as the question of the solvers is concerned, generic FEM codes are found to lack efficiency: they cannot reach high enough levels of discretization with classical free meshes, and they do not take advantage of the regular structure of the mesh. Thus, a specific finite differences/finite volumes solver has been developed. At first, generic off-the-shelf linear system solvers were used. To further improve the efficiency in terms of memory requirements, specific variants of the preconditioned conjugate gradient were implemented. This allowed to homogenize the conductivity of a concrete-like microstructure using more than 10{sup 9} degrees of freedom on a rather common hardware for 2010 (a PC embedding 48 GB of RAM). Taking benefit of the properties of the regular Cartesian grid we have also investigated a multi-level method to improve the CPU efficiency of the code.

  2. Method of fabricating a homogeneous wire of inter-metallic alloy

    DOE Patents [OSTI]

    Ohriner, Evan Keith (Knoxville, TN); Blue, Craig Alan (Knoxville, TN)

    2001-01-01T23:59:59.000Z

    A method for fabricating a homogeneous wire of inter-metallic alloy comprising the steps of providing a base-metal wire bundle comprising a metal, an alloy or a combination thereof; working the wire bundle through at least one die to obtain a desired dimension and to form a precursor wire; and, controllably heating the precursor wire such that a portion of the wire will become liquid while simultaneously maintaining its desired shape, whereby substantial homogenization of the wire occurs in the liquid state and additional homogenization occurs in the solid state resulting in a homogenous alloy product.

  3. Solar energy storage through the homogeneous electrocatalytic reduction of carbon dioxide : photoelectrochemical and photovoltaic approaches

    E-Print Network [OSTI]

    Sathrum, Aaron John

    2011-01-01T23:59:59.000Z

    electricity from photovoltaic cells to convert CO 2 intoSolar Energy Anode Photovoltaic Cell Cathode PP Mesh SpacerCoupling a Photovoltaic Solar Cell with a Homogeneous

  4. Bifurcation behavior in homogeneous-heterogeneous combustion. Part 2; Computations for stagnation-point flow

    SciTech Connect (OSTI)

    Song, X.; Williams, W.R.; Schmidt, L.D.; Aris, R. (Dept. of Chemical Engineering and Materials Science, Univ. of Minnesota, Minneapolis, MN (US))

    1991-04-01T23:59:59.000Z

    Bifurcation analysis of ignition and extinction of combustion in stagnation-point flow was carried out for conditions when both homogeneous and heterogeneous reactions can occur. A technique based on the bifurcation theory and the shooting algorithm is developed, which permits fast and efficient tracking of bifurcation in these systems. The influences of the different parameters on the ignition and extinction behavior were investigated by assuming (1) only catalytic surface (heterogeneous) reaction, (2) only homogeneous reaction on a hot inert surface, and (3) both surface and homogeneous reactions. The coupling effects of the homogeneous and heterogeneous reactions are clearly demonstrated. It is shown that the heterogeneous reaction dominates the system behavior at the lower temperature while both homogeneous and heterogeneous reactions play important role at higher temperature. It is predicted that the homogeneous ignition temperature is higher with surface reaction than without surface reaction. However, homogeneous-heterogeneous or homogeneous reaction alone. The numerical results for propane and for methane oxidation on platinum foil also show good qualitative agreements with the experimental results of Part I of this article, which include the two types of ignition, extinction and autothermal behavior of homogeneous-heterogeneous reactions.

  5. Improved Modeling of Transition Metals, Applications to Catalysis and Technetium Chemistry

    SciTech Connect (OSTI)

    Cundari, T. R.

    2004-03-05T23:59:59.000Z

    There is considerable impetus for identification of aqueous OM catalysts as water is the ultimate ''green'' solvent. In collaboration with researchers at Ames Lab, we investigated effective fragment and Monte Carlo techniques for aqueous-phase hydroformylation (HyF). The Rh of the HyF catalyst is weakly aquated, in contrast to the hydride of the Rh-H bond. As the insertion of the olefin C=C into Rh-H determines the linear-to-branched aldehyde ratio, it is reasonable to infer that solvent plays an important role in regiochemistry. Studies on aqueous-phase organometallic catalysis were complemented in studies of the gas-phase reaction. A Rh-carbonyl-phosphine catalyst was investigated. Two of the most important implications of this research include (a) pseudorotation among five-coordinate intermediates is significant in HyF, and (b) CO insertion is the rate-determining step. The latter is in contrast to experimental deductions, highlighting the need for more accurate modeling. To this end, we undertook studies of (a) experimentally relevant PR{sub 3} co-ligands (PMe{sub 3}, PPh{sub 3}, P(p-PhSO{sub 3{sup -}}){sub 3}, etc.), and (b) HyF of propene. For the propylene research, simulations indicated that the linear: branched aldehyde ratio (linear is more desirable) is determined by thermodynamic discrimination of two distinct pathways. Other projects include a theory-experiment study of C-H activation by early transition metal systems, which establishes that weakly-bound adducts play a key role in activity selectivity. By extension, more selective catalysts for functionalization of methane (major component of natural gas) will require better understanding of these adducts, which are greatly affected by steric interactions with the ligands. In the de novo design of Tc complexes, we constructed (and are now testing) a coupled quantum mechanics-molecular mechanics protocol. Initial research shows it to be capable of accurately predicting structure ''from scratch.'' Challenges include conformational, geometric, coordination, spin, and particularly linkage (e.g., Tc-SCN versus Tc-NCS) isomerism. In general, our protocol can rapidly (<1 day with desktop software/hardware) predict the structure of diverse Tc complexes with an accuracy commensurate to organics. Our de novo strategy is also being used to investigate tris-pyrazolyl borate (Tp) complexes. Data suggests a fundamental difference in methane activation between TpRe and related CpRe complexes. Furthermore, Tp is a more electronically ''flexible'' platform for catalysts modification than Cp.

  6. Resonant Interactions in Rotating Homogeneous Three-dimensional Turbulence

    E-Print Network [OSTI]

    Q. Chen; S. Chen; G. L. Eyink; D. D. Holm

    2004-04-29T23:59:59.000Z

    Direct numerical simulations of three-dimensional (3D) homogeneous turbulence under rapid rigid rotation are conducted to examine the predictions of resonant wave theory for both small Rossby number and large Reynolds number. The simulation results reveal that there is a clear inverse energy cascade to the large scales, as predicted by 2D Navier-Stokes equations for resonant interactions of slow modes. As the rotation rate increases, the vertically-averaged horizontal velocity field from 3D Navier-Stokes converges to the velocity field from 2D Navier-Stokes, as measured by the energy in their difference field. Likewise, the vertically-averaged vertical velocity from 3D Navier-Stokes converges to a solution of the 2D passive scalar equation. The energy flux directly into small wave numbers in the $k_z=0$ plane from non-resonant interactions decreases, while fast-mode energy concentrates closer to that plane. The simulations are consistent with an increasingly dominant role of resonant triads for more rapid rotation.

  7. Homogeneous isotropic turbulence in dilute polymers: scale by scale budget

    E-Print Network [OSTI]

    E. De Angelis; C. M. Casciola; R. Benzi; R. Piva

    2002-08-09T23:59:59.000Z

    The turbulent energy cascade in dilute polymers solution is addressed here by considering a direct numerical simulation of homogeneous isotropic turbulence of a FENE-P fluid in a triply periodic box. On the basis of the DNS data, a scale by scale analysis is provided by using the proper extension to visco-elastic fluids of the Karman-Howarth equation for the velocity. For the microstructure, an equation, analogous to the Yaglom equation for scalars, is proposed for the free-energy density associated to the elastic behavior of the material. Two mechanisms of energy removal from the scale of the forcing are identified, namely the classical non-linear transfer term of the standard Navier-Stokes equations and the coupling between macroscopic velocity and microstructure. The latter, on average, drains kinetic energy to feed the dynamics of the microstructure. The cross-over scale between the two corresponding energy fluxes is identified, with the flux associated with the microstructure dominating at small separations to become sub-leading above the cross-over scale, which is the equivalent of the elastic limit scale defined by De Gennes-Tabor on the basis of phenomenological assumptions.

  8. Homogeneous ice nucleation evaluated for several water models

    E-Print Network [OSTI]

    J. R. Espinosa; E. Sanz; C. Valeriani; C. Vega

    2014-11-25T23:59:59.000Z

    In this work, we evaluate by means of computer simulations the rate for ice homogeneous nucleation for several water models such as TIP4P, TIP4P/2005,TIP4P/ICE, and mW (following the same procedure as in Sanz et al. [J. Am. Chem. Soc.135, 15008 (2013)]) in a broad temperature range. We estimate the ice-liquid interfacial free-energy, and conclude that for all water models {\\gamma} decreases as the temperature decreases. Extrapolating our results to the melting temperature, we obtain a value of the interfacial free-energy between 25 and 32 mN/m in reasonable agreement with the reported experimental values. Moreover, we observe that the values of {\\gamma} depend on the chosen water model and this is a key factor when numerically evaluating nucleation rates, given that the kinetic prefactor is quite similar for all water models with the exception of the mW (due to the absence of hydrogens). Somewhat surprisingly the estimates of the nucleation rates found in this work for TIP4P/2005 are slightly higher than those of the mW model, even though the former has explicit hydrogens. Our results suggest that it may be possible to observe in computer simulations spontaneous crystallization of TIP4P/2005 at about 60 K below the melting point.

  9. Dynamic control of a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Mehresh, Parag (Peoria, IL); Schuh, David (Peoria, IL); Kieser, Andrew J. (Morton, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL)

    2008-06-03T23:59:59.000Z

    A homogenous charge compression ignition engine is operated by compressing a charge mixture of air, exhaust and fuel in a combustion chamber to an autoignition condition of the fuel. The engine may facilitate a transition from a first combination of speed and load to a second combination of speed and load by changing the charge mixture and compression ratio. This may be accomplished in a consecutive engine cycle by adjusting both a fuel injector control signal and a variable valve control signal away from a nominal variable valve control signal. Thereafter in one or more subsequent engine cycles, more sluggish adjustments are made to at least one of a geometric compression ratio control signal and an exhaust gas recirculation control signal to allow the variable valve control signal to be readjusted back toward its nominal variable valve control signal setting. By readjusting the variable valve control signal back toward its nominal setting, the engine will be ready for another transition to a new combination of engine speed and load.

  10. Soliton ratchets in homogeneous nonlinear Klein-Gordon systems

    E-Print Network [OSTI]

    Luis Morales-Molina; Niurka R. Quintero; Franz G. Mertens; Angel Sanchez

    2005-11-30T23:59:59.000Z

    We study in detail the ratchet-like dynamics of topological solitons in homogeneous nonlinear Klein-Gordon systems driven by a bi-harmonic force. By using a collective coordinate approach with two degrees of freedom, namely the center of the soliton, $X(t)$, and its width, $l(t)$, we show, first, that energy is inhomogeneously pumped into the system, generating as result a directed motion; and, second, that the breaking of the time shift symmetry gives rise to a resonance mechanism that takes place whenever the width $l(t)$ oscillates with at least one frequency of the external ac force. In addition, we show that for the appearance of soliton ratchets, it is also necesary to break the time-reversal symmetry. We analyze in detail the effects of dissipation in the system, calculating the average velocity of the soliton as a function of the ac force and the damping. We find current reversal phenomena depending on the parameter choice and discuss the important role played by the phases of the ac force. Our analytical calculations are confirmed by numerical simulations of the full partial differential equations of the sine-Gordon and $\\phi^4$ systems, which are seen to exhibit the same qualitative behavior. Our results are in agreement with recent experimental work on dissipation induced symmetry breaking.

  11. Type Ia Supernova Explosion Models: Homogeneity versus Diversity

    E-Print Network [OSTI]

    W. Hillebrandt; J. C. Niemeyer; M. Reinecke

    2000-05-30T23:59:59.000Z

    Type Ia supernovae (SN Ia) are generally believed to be the result of the thermonuclear disruption of Chandrasekhar-mass carbon-oxygen white dwarfs, mainly because such thermonuclear explosions can account for the right amount of Ni-56, which is needed to explain the light curves and the late-time spectra, and the abundances of intermediate-mass nuclei which dominate the spectra near maximum light. Because of their enormous brightness and apparent homogeneity SN Ia have become an important tool to measure cosmological parameters. In this article the present understanding of the physics of thermonuclear explosions is reviewed. In particular, we focus our attention on subsonic (``deflagration'') fronts, i.e. we investigate fronts propagating by heat diffusion and convection rather than by compression. Models based upon this mode of nuclear burning have been applied very successfully to the SN Ia problem, and are able to reproduce many of their observed features remarkably well. However, the models also indicate that SN Ia may differ considerably from each other, which is of importance if they are to be used as standard candles.

  12. Panaches horizontaux non-Boussinesq en milieu homog\\`ene

    E-Print Network [OSTI]

    Daddi-Moussa-Ider, Abdallah; Mehaddi, Rabah; Vauquelin, Olivier; Candelier, Fabien

    2014-01-01T23:59:59.000Z

    The environmental impact of pollutants and effluents discharged into the atmosphere or the oceans has led researchers to conduct studies related to this issue. Several works have been carried out in this context in order to reduce the effect on the local environment. These types of ejections in nature are modeled as jets in the presence of a density gradient. In this study we treated the problem of inclined round turbulent buoyant jets and plumes ejected in a homogeneous or stratified fluid, at rest or in motion. The prediction of the flow behavior, i.e. the evolution of its variables, is first treated theoretically from a model whose formalism is valid in both the Boussinesq case as well as in the non-Boussinesq general case. Solving the equations governing the plumes is performed numerically using a Runge-Kutta 4th order. To validate the model, laboratory experiments are performed with round jets of air and helium for a wide range of densities. The confrontation theory-experience aims here to fix the limits...

  13. acc synthase gene: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 211 Reverse engineering a...

  14. arabidopsis spermidine synthase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 217 Reverse engineering a...

  15. acid synthase fasii: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 87 Reverse engineering a...

  16. adenosine triphosphate atp: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 199 Structure of the Bis(Mg2+...

  17. atp binding protein: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 408 Interplay of pH and Binding...

  18. atp synthase subunit: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 12 ATP Synthase: Two rotary...

  19. arabidopsis atp a2: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 159 Structure of the Bis(Mg2+...

  20. atp biosynthesis induces: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 142 Structure of the Bis(Mg2+...

  1. atp synthase complex: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 12 Quantification of the...

  2. atp stimulates chemokine: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 164 Structure of the Bis(Mg2+...

  3. acid synthase ii: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 131 Reverse engineering a...

  4. acid synthase gene: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 169 Reverse engineering a...

  5. acetolactase synthase inhibitor: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 94 Reverse engineering a...

  6. atp synthase inhibition: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 10 Quantification of the...

  7. acetolactate synthase inhibitor: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 98 Reverse engineering a...

  8. acetolactate synthase inhibitors: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 98 Reverse engineering a...

  9. atp diphosphohydrolases potential: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 117 Structure of the Bis(Mg2+...

  10. atp synthetic flux: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 204 Structure of the Bis(Mg2+...

  11. atp receptor modulates: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 219 Structure of the Bis(Mg2+...

  12. atp p2 receptors: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 First Page Previous Page 1 2 3...

  13. arabidopsis callose synthase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 219 Reverse engineering a...

  14. atp hydrolysis mediated: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 58 January 2007 Economic Impact...

  15. atp channels reduces: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 172 Structure of the Bis(Mg2+...

  16. acid 8-phosphate synthase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 87 Reverse engineering a...

  17. atp level variations: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 74 The Design of the CADE13 ATP...

  18. autoinducer synthase lqsa: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 70 Reverse engineering a...

  19. atps part iii: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 64 The CADE-18 ATP System...

  20. atp activates map: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 85 Allosteric Effects of RuvA...

  1. atp citrate lyase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 155 Structure of the Bis(Mg2+...

  2. acetolactate synthase genes: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 102 Reverse engineering a...

  3. automatic f0 stylisation: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 88 ROBUST SPEECH END-POINT...

  4. acetohydroxy acid synthase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 87 Reverse engineering a...

  5. atp synthase ohmic: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 10 Quantification of the...

  6. atp hydrolysis activity: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 55 Toxicology 212 (2005) 107115...

  7. atp increase extracellular: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 167 Structure of the Bis(Mg2+...

  8. atp binding residues: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 57 January 2007 Economic Impact...

  9. atp reduction affects: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 117 Structure of the Bis(Mg2+...

  10. atp binding cassette: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 43 CFTR chloride channels and...

  11. atp sensitive potassium: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 173 Structure of the Bis(Mg2+...

  12. atp a2 peroxidase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 135 Structure of the Bis(Mg2+...

  13. angiostatin binds atp: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 35 January 2007 Economic Impact...

  14. atp binding domain: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 157 Molecular composition of...

  15. atp hydrolysis potential: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 58 January 2007 Economic Impact...

  16. acetyl coa synthase: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 140 Reverse engineering a...

  17. atp inhibits root: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 First Page Previous Page 1 2 3...

  18. atp turnover rate: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 202 Structure of the Bis(Mg2+...

  19. atp turnover inhibition: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 190 Structure of the Bis(Mg2+...

  20. atp generation capacity: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 188 Structure of the Bis(Mg2+...

  1. atp hydrolysis mechanism: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 82 Rapid Hydrolysis of 2,3-cAMP...

  2. acid synthase depends: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 56 Phosphorylation of Yeast...

  3. atp induced vasodilatation: Topics by E-print Network

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

    corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 115 Structure of the Bis(Mg2+...

  4. advanced computation languages: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 Advanced Topics in Types and Programming Languages Computer Technologies and Information Sciences Websites Summary: Advanced Topics in Types and...

  5. Degradation of resolution in a homogeneous dual readout hadronic calorimeter

    E-Print Network [OSTI]

    Donald E. Groom

    2012-12-26T23:59:59.000Z

    If the response to a hadronic shower in a semi-infinite uniform calorimeter structure is $S$ relative to the electronic response, then $S/E = [\\fem + (1-\\fem)(h/e)]$, where $E$ is the incident hadron energy, $\\fem$ is the electronic shower fraction, and $h/e$ is the hadron/electron response ratio. In conventional calorimeters the energy resolution is dominated by the stochastic variable $\\fem$, whose broad, skewed pdf has an energy-dependent mean. The slow increase of the mean with $E$ is responsible for response nonlinearity and the skewness results in a non-Gaussian response. If the cascade is observed in two channels with different values of $h/e$ (typically scintillator($S$) and Cherenkov ($C$)), $\\fem$ can be eliminated. An energy estimator, linear in $C$ and $S$, is obtained which is proportional to the incident hadron's energy. The resolution depends upon the contrast in $h/e$ between the two channels. The Cherenkov $h/e$ will be 0.20--0.25. In sampling calorimeters, $h/e$ can be increased to about 0.7 by arranging for preferential absorption of the electromagnetic (EM) shower energy in the absorber (decreasing $e$) and using a hydrogenous detector (organic scintillator) to enhance $h$ through the contribution of recoil protons in $n$--$p$ scattering. Neither mechanism is available in a homogeneous crystal or glass scintillator,\\rm where $h/e$is expected to be in the vicinity of 0.4 because of invisible hadronic energy loss and other effects. The $h/e$ contrast is very likely too small to provide the needed energy resolution. We support this conclusion with simple Monte Carlo simulations.

  6. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    SciTech Connect (OSTI)

    Keith James Stanger

    2003-05-31T23:59:59.000Z

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-{alpha}-acetamidocinnamate (MAC), has the illustrated structure as established by {sup 31}P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]{sub 4}, [Rh(COD){sub 2}]{sup +}BF{sub 4}{sup -}, [Rh(COD)Cl]{sub 2}, and RhCl{sub 3} {center_dot} 3H{sub 2}O, adsorbed on SiO{sub 2} are optimally activated for toluene hydrogenation by pretreatment with H{sub 2} at 200 C. The same complexes on Pd-SiO{sub 2} are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH{sub 2}){sub 3}s-]Re(O)(Me)(PPh{sub 3}) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  7. SELECTIVE REDUCTION OF NOX IN OXYGEN RICH ENVIRONMENTS WITH PLASMA-ASSISTED CATALYSIS: CATALYST DEVELOPMENT AND MECHANISTIC STUDIES

    SciTech Connect (OSTI)

    Peden, C; Barlow, S; Hoard, J; Kwak, J; *Balmer-Millar, M; *Panov, A; Schmieg, S; Szanyi, J; Tonkyn, R

    2003-08-24T23:59:59.000Z

    The control of NOx (NO and NO2) emissions from so-called ''lean-burn'' vehicle engines remains a challenge. In recent years, there have been a number of reports that show that a plasma device combined with a catalyst can reduce as high as 90% or more of NOx in simulated diesel and other ''lean-burn'' exhaust. In the case of propylene containing simulated diesel exhaust, the beneficial role of a plasma treatment is now thought to be due to oxidation of NO to NO2, and the formation of partially oxidized hydrocarbons that are more active for the catalytic reduction of NO2 than propylene. Thus, the overall system can be most usefully described as hydrocarbon selective catalytic reduction (SCR) enhanced by 'reforming' the exhaust with a non-thermal plasma (NTP) device. For plasma-enhanced catalysis, both zeolite- and alumina-based materials have shown high activity, albeit in somewhat different temperature ranges, when preceded by an NTP reactor. This paper will briefly describe our research efforts aimed at optimizing the catalyst materials for NTP-catalysis devices based, in part, on our continuing studies of the NTP- and catalytic-reaction mechanisms. Various alkali- and alkaline earth-cation-exchanged Y zeolites have been prepared, their material properties characterized, and they have been tested as catalytic materials for NOx reduction in laboratory NTP-catalysis reactors. Interestingly, NO2 formed in the plasma and not subsequently removed over these catalysts, will back-convert to NO, albeit to varying extents depending upon the nature of the cation. Besides this comparative reactivity, we will also discuss selected synthesis strategies for enhancing the performance of these zeolite-based catalyst materials. A particularly important result from our mechanistic studies is the observation that aldehydes, formed during the plasma treatment of simulated diesel exhaust, are the important species for the reduction of NOx to N2. Indeed, acetaldehyde has been found to be especially effective in the thermal reduction of both NO and NO2 over Ba- and Na-Y zeolite catalysts.

  8. Analysis of combustion in a small homogeneous charge compression assisted ignition engine

    E-Print Network [OSTI]

    237 Analysis of combustion in a small homogeneous charge compression assisted ignition engine H Ma1 characteristics to homogeneous charge compression ignition (HCCI) engines. Difficulties such as unknown ignition timing and the polytropic index have been addressed by combining both heat release and mass fraction burn

  9. Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces Philippe of geometric control theory arguments. Keywords: Lie groups; Homogeneous spaces; Linear systems; Com- plete JOUAN 28th November 2008 Abstract The aim of this paper is to prove that a control affine system

  10. Effect of high pressure homogenization on the physical properties of milk

    E-Print Network [OSTI]

    Gonzalez De Cossio, Carlos

    1994-01-01T23:59:59.000Z

    Milk was homogenized at pressures ranging from 17.2 MPa to 100 MPa to determine the effect of homogenization pressure on the fat globule size distribution, viscosity, color, and temperature changes in milk. Milk containing 0, 1.5 and 3.0% milk fat...

  11. Application of the Hanbury BrownTwiss effect to scattering from quasi-homogeneous media

    E-Print Network [OSTI]

    Visser, Taco D.

    Application of the Hanbury Brown­Twiss effect to scattering from quasi-homogeneous media David: Hanbury Brown-Twiss effect Scattering Born approximation Quasi-homogeneous media Inverse scattering a b scattering media, is studied by the use of the Hanbury Brown­Twiss effect. In particular the two

  12. Space-time BIE methods for non homogeneous exterior wave equation problems. The Dirichlet case.

    E-Print Network [OSTI]

    Ceragioli, Francesca

    Space-time BIE methods for non homogeneous exterior wave equation problems. The Dirichlet case. S. Falletta , G. Monegato , L. Scuderi§ Abstract In this paper we consider the (2D and 3D) exterior problem; non homogeneous conditions; space-time boundary integral equations; numerical methods This work

  13. Data-driven Techniques to Estimate Parameters in the Homogenized Energy Model for Shape Memory Alloys

    E-Print Network [OSTI]

    Data-driven Techniques to Estimate Parameters in the Homogenized Energy Model for Shape Memory. In this paper, we focus on the homogenized energy model for shape memory alloys (SMA). Specifically, we develop parameters are compared to the initial estimates. 1 Introduction Shape memory alloys (SMA) are novel

  14. Near Optimal Broadcast with Network Coding in Large Homogeneous Wireless Sensor Networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Near Optimal Broadcast with Network Coding in Large Homogeneous Wireless Sensor Networks C of wireless "homogeneous" sensor networks contained of the plane: wireless lattice networks, and dense unit of application is wireless sensor net- works, and indeed network coding has been used in wireless networks

  15. Mechanisms of Homogeneous Nucleation of Polymers of Sickle Cell Anemia Hemoglobin in Deoxy State

    E-Print Network [OSTI]

    Vekilov, Peter

    Mechanisms of Homogeneous Nucleation of Polymers of Sickle Cell Anemia Hemoglobin in Deoxy State, TX 77204-4004, USA The primary pathogenic event of sickle cell anemia is the polymerization reserved. Keywords: sickle cell anemia; hemoglobin S polymerization; fiber nucleation; homogeneous

  16. Unsteady Flow Evolution and Combustion Dynamics of Homogeneous Solid Propellant in a Rocket Motor

    E-Print Network [OSTI]

    Apte, Sourabh V.

    Unsteady Flow Evolution and Combustion Dynamics of Homogeneous Solid Propellant in a Rocket Motor University, University Park, PA 16802, USA A time-resolved numerical analysis of combustion dynamics of double-base homogenous solid propellant in a rocket motor is performed by means of a Large

  17. Homogeneous, dual layer, solid state, thin film deposition for structural and/or electrochemical characteristics

    DOE Patents [OSTI]

    Pitts, J. Roland; Lee, Se-Hee; Tracy, C. Edwin; Li, Wenming

    2014-04-08T23:59:59.000Z

    Solid state, thin film, electrochemical devices (10) and methods of making the same are disclosed. An exemplary device 10 includes at least one electrode (14) and an electrolyte (16) deposited on the electrode (14). The electrolyte (16) includes at least two homogenous layers of discrete physical properties. The two homogenous layers comprise a first dense layer (15) and a second porous layer (16).

  18. Scheduling Parallel Task Graphs on (Almost) Homogeneous Multi-cluster Platforms

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Scheduling Parallel Task Graphs on (Almost) Homogeneous Multi-cluster Platforms Pierre these applications efficiently on parallel platforms has been a long-standing challenge. In the case of a single homogeneous platform, such as a cluster, results have been obtained both in theory, i.e., guaranteed

  19. II-Local Solution of a Spherical Homogeneous and Isotropic Universe Radially Decelerated towards the Expansion Center: Tests on Historic Data Sets

    E-Print Network [OSTI]

    Luciano Lorenzi

    1999-06-17T23:59:59.000Z

    The topic of the paper is the mathematical analysis of a radially decelerated Hubble expansion from the Bahcall & Soneira void center. Such analysis, in the hypothesis of local homogeneity and isotropy, gives a particular Hubble ratio dipole structure to the expansion equation, whose solution has been studied at different precision orders and successfully tested on a few historic data sets, by de Vaucouleurs (1965), by Sandage & Tammann (1975), and by Aaronson et al. (1982-86). The fittings of both the separate AA1 and AA2 samples show a good solution convergence as the analysis order increases, giving even coinciding solutions when applied to 308 nearby individual galaxies (308AA1) and to 10 clusters (148AA2), respectively.

  20. Crystal Structure of 12-Lipoxygenase Catalytic-Domain-Inhibitor Complex Identifies a Substrate-Binding Channel for Catalysis

    SciTech Connect (OSTI)

    Xu, Shu; Mueser, Timothy C.; Marnett, Lawrence J.; Funk, Jr., Max O. (Toledo); (Vanderbilt)

    2014-10-02T23:59:59.000Z

    Lipoxygenases are critical enzymes in the biosynthesis of families of bioactive lipids including compounds with important roles in the initiation and resolution of inflammation and in associated diseases such as diabetes, cardiovascular disease, and cancer. Crystals diffracting to high resolution (1.9 {angstrom}) were obtained for a complex between the catalytic domain of leukocyte 12-lipoxygenase and the isoform-specific inhibitor, 4-(2-oxapentadeca-4-yne)phenylpropanoic acid (OPP). In the three-dimensional structure of the complex, the inhibitor occupied a new U-shaped channel open at one end to the surface of the protein and extending past the redox-active iron site that is essential for catalysis. In models, the channel accommodated arachidonic acid, defining the binding site for the substrate of the catalyzed reaction. There was a void adjacent to the OPP binding site connecting to the surface of the enzyme and providing a plausible access channel for the other substrate, oxygen.

  1. Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999

    SciTech Connect (OSTI)

    Cutler, Alan R.

    2001-04-14T23:59:59.000Z

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a doxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(CO){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(l) precatalysts. The reaction chemistry of the above and other Mn alkyl complexes with hydrosilanes was studied in order to probe catalysis mechanism(s). Thus, Mn(CO){sub 5} methyl, benzyl, acetyl, and benzoyl (4 p-substituents) complexes reacted with hydrosilines by four different mechanisms, which were established. A noteworthy development was that the methyl and benzoyl complexes gave moderate yields of a new ({eta}{sup 2}-Si-H) silane adduct (CO){sub 4}Mn(SiMe{sub 2}Ph)(H-SiMe{sub 2}Ph), which is stable in the presence of excess silane. This silane adduct promotes all three catalytic reactions; its extraordinary activity and potential selectivity are under study.

  2. High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines

    SciTech Connect (OSTI)

    None

    2011-01-31T23:59:59.000Z

    This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustion and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well-to-wheels analysis of the energy flows in a mobile vehicle system and a 2nd Law thermodynamic analysis of the engine system were also completed under this program.

  3. au-ag alloy shunt: Topics by E-print Network

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

    through complex angular momentum analysis as the fundamental atomic mechanism underlying nano-scale catalysis. Here we investigate the optimization of the catalytic behavior of...

  4. active-site structure binding: Topics by E-print Network

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

    Threshold Occupancy and Specific Cation Binding Modes in the Hammerhead Ribozyme Active Site components to facilitate catalysis through electrostatic engineering. In the case of...

  5. alkali-silica reaction gel: Topics by E-print Network

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

    Description Engineering Websites Summary: , separations science, chemical catalysis and coatings science. By definition the sol-gel process starts materials. The resulting films,...

  6. argonne heavy water modified reactor: Topics by E-print Network

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

    7 Argonne National Laboratory Chemical Engineering Division Water-gas shift catalysis Energy Storage, Conversion and Utilization Websites Summary: Argonne National Laboratory...

  7. Research of a boundary condition quantifiable correction method in the assembly homogenization

    SciTech Connect (OSTI)

    Peng, L. H.; Liu, Z. H.; Zhao, J. [Inst. of Nuclear and New Energy Technology, Tsinghua Univ., Beijing, 100084 (China); Li, W. H. [China Nuclear Power Technology Research Inst., Shenzhen, 518026 (China)

    2012-07-01T23:59:59.000Z

    The methods and codes currently used in assembly homogenization calculation mostly adopt the reflection boundary conditions. The influences of real boundary conditions on the assembly homogenized parameters were analyzed. They were summarized into four quantifiable effects, and then the mathematical expressions could be got by linearization hypothesis. Through the calculation of a test model, it had been found that the result was close to transport calculation result when considering four boundary quantifiable effects. This method would greatly improve the precision of a core design code which using the assembly homogenization methods, but without much increase of the computing time. (authors)

  8. Effect of homogenization pressure and milk composition on some physical properties of yogurt

    E-Print Network [OSTI]

    Lin, Chun-An

    1995-01-01T23:59:59.000Z

    (Fig. 7). The increase in firmness due to increased MF concentration was not linear. The increase in firmness that was observed when the MF concentration of the yogurt was increased &om 2 to 4% was much greater than the increase in firmness when MF...) Figure 6. Effect of homogenization pressure (HP) and solids-not-fat (SNF) on the firmness of yogurt. 25 120 4% MF 110 100 90 2% MF 80 70 0% MF 60 3000 6000 9000 12000 15000 Homogenization pressure (psi) Figure 7. Effect of homogenization...

  9. alfvenic mhd activity: Topics by E-print Network

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

    energy decay in homogeneous MHD turbulence? Physics Websites Summary: Is the Alfven-wave propagation effect important for energy decay in homogeneous MHD turbulence-...

  10. attenuates methamphetamine-induced overexpression: Topics by...

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

    and borehole acoustic models. The validity of the scheme is established using a 3D homogenous isotropic ... Krasovec, Mary L. 2003-01-01 25 1997 Cancer Research...

  11. TOPIC MODELS DAVID M. BLEI

    E-Print Network [OSTI]

    Blei, David M.

    TOPIC MODELS DAVID M. BLEI PRINCETON UNIVERSITY JOHN D. LAFFERTY CARNEGIE MELLON UNIVERSITY 1 of the original texts Blei et al. (2003); Grif- fiths and Steyvers (2004); Buntine and Jakulin (2004); Hofmann email ?, scientific abstracts Griffiths and Steyvers (2004); Blei et al. (2003), and newspaper archives

  12. Characterizing Scattering by 3-D Arbitrarily Shaped Homogeneous Dielectric Objects Using Fast Multipole Method

    E-Print Network [OSTI]

    Li, Jian-Ying

    Electromagnetic scattering by 3-D arbitrarily shaped homogeneous dielectric objects is characterized. In the analysis, the method of moments is first employed to solve the combined field integral equation for scattering ...

  13. Dark energy homogeneity in general relativity: are we applying it correctly?

    E-Print Network [OSTI]

    Duniya, Didam

    2015-01-01T23:59:59.000Z

    Thusfar, there does not appear to be an agreed definition of homogeneous dark energy (DE). In this work, we argue that a correct definition of homogeneous DE is one whose density perturbation in comoving gauge vanishes. Using different DE models, we then investigate the consequence of this approach in the power spectrum -- with all the power spectra being normalized to match each other on small scales, at z = 0. We find that on super-Hubble scales, relativistic corrections in the observed galaxy power spectrum are able to distinguish a homogeneous DE from the concordance model and from a clustering DE, at low z and for high magnification bias. However, the matter power spectrum: is incapable of distinguishing a homogeneous DE from the concordance model (on all scales), at z = 0; but is able to differentiate it from a clustering DE, particularly at low z. Moreover, we found that relativistic effects become enhanced with decreasing magnification bias, and with increasing z.

  14. Thermodynamics In Einstein equation, the energy momentum tensor of homogeneous, isotropic

    E-Print Network [OSTI]

    Murayama, Hitoshi

    Thermodynamics In Einstein equation, the energy momentum tensor of homogeneous, isotropic fluid using the 1st law of thermodynamics, T = (U/S)V . Since U = V is expressed in terms of the temperature

  15. Homogeneous Factorisations of Graphs and Michael Giudici a, Cai Heng Li a

    E-Print Network [OSTI]

    Giudici, Michael

    Homogeneous Factorisations of Graphs and Digraphs Michael Giudici a, Cai Heng Li a Primoz Potocnik@maths.uwa.edu.au (Michael Giudici), li@maths.uwa.edu.au (Cai Heng Li), primoz.potocnik@fmf.uni-lj.si (Primoz Preprint

  16. Extension of the high load limit in the Homogeneous Charge Compression Ignition engine

    E-Print Network [OSTI]

    Scaringe, Robert J. (Robert Joseph)

    2009-01-01T23:59:59.000Z

    The Homogeneous Charge Compression Ignition (HCCI) engine offers diesel-like efficiency with very low soot and NOx emissions. In a HCCI engine, a premixed charge of air, fuel and burned gas is compressed to achieve ...

  17. Molecular simulation study of homogeneous crystal nucleation in n-alkane melts

    E-Print Network [OSTI]

    Yi, Peng, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    This work used molecular dynamics (MD) and Monte Carlo (MC) method to study the homogeneous crystal nucleation in the melts of n-alkanes, the simplest class of chain molecules. Three n-alkanes with progressive chain length ...

  18. RATE OF STRAIN TENSOR STATISTICS IN COMPRESSIBLE HOMOGENEOUS G. Erlebacher 1 , S. Sarkar 1

    E-Print Network [OSTI]

    Erlebacher, Gordon

    RATE OF STRAIN TENSOR STATISTICS IN COMPRESSIBLE HOMOGENEOUS TURBULENCE G. Erlebacher 1 , S. Sarkar was determined in Sarkar, Erlebacher and Hus­ saini (ref. 2) to be due to enhanced compressible dis­ sipation

  19. An investigation into the properties and characteristics of homogeneous tapered cables

    E-Print Network [OSTI]

    deCastongrene, Russell Othomar

    1975-01-01T23:59:59.000Z

    AN INVESTIGATION INTO THE PROPERTIES AND CHABACTEBISTICS OF HOMOGENEOUS TAPL'BED CABLES A Thesis by RUSSELL OTHOMAR deCASTONGBENE Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement sor... the degree of MASTER OF SCIENCF. May 1975 Major Subject: Civil Engineering AN INVESTIGATION INTO THE PROPERTIES AND CHARACTERISTICS OF HOMOGENEOUS TAPERED CABLES A Thesis RUSSELL OTHOMAR deCASTONGRENE Approved as to style and content by: ( irman...

  20. Integration of geodesic flows on homogeneous spaces: the case of a wild lie group

    E-Print Network [OSTI]

    A. A. Magazev; I. V. Shirokov

    2007-03-21T23:59:59.000Z

    We obtain necessary and sufficient conditions for the integrability in quadratures of geodesic flows on homogeneous spaces $M$ with invariant and central metrics. The proposed integration algorithm consists in using a special canonical transformation in the space $T^*M$ based on constructing the canonical coordinates on the orbits of the coadjoint representation and on the simplectic sheets of the Poisson algebra of invariant functions. This algorithm is applicable to integrating geodesic flows on homogeneous spaces of a wild Lie group.

  1. The effect of temperature and homogenization pressure on enzymatic activity in cheese whey 

    E-Print Network [OSTI]

    Del Carmen, Maria Yanina

    1995-01-01T23:59:59.000Z

    THE EFFECT OF TEMPERATURE AND HOMOGENIZATION PRESSURE ON ENZYMATIC ACTIVITY IN CHEESE WHEY A Thesis by MARIA YANINA DEL CAWvKN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1995 Major Subject; Food Science and Technology THE EFFECT OF TEMPERATURE AND HOMOGENIZATION PRESSURE ON ENZYMATIC ACTIVITY IN CHEESE WHEY A Thesis by MARIA YANINA DEL CARMEN Submitted to the Office of Graduate...

  2. The effect of temperature and homogenization pressure on enzymatic activity in cheese whey

    E-Print Network [OSTI]

    Del Carmen, Maria Yanina

    1995-01-01T23:59:59.000Z

    THE EFFECT OF TEMPERATURE AND HOMOGENIZATION PRESSURE ON ENZYMATIC ACTIVITY IN CHEESE WHEY A Thesis by MARIA YANINA DEL CAWvKN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1995 Major Subject; Food Science and Technology THE EFFECT OF TEMPERATURE AND HOMOGENIZATION PRESSURE ON ENZYMATIC ACTIVITY IN CHEESE WHEY A Thesis by MARIA YANINA DEL CARMEN Submitted to the Office of Graduate...

  3. Two dimensional finite element analysis of homogenization and failure in plain weave textile composites

    E-Print Network [OSTI]

    Kondagunta, Veeraraghava Gopal

    1993-01-01T23:59:59.000Z

    TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA Submitted to the Office of Graduate Studies of Texas ARM University In partial fulffllment... of the requirements for the degree of MASTER OF SCIENCE August 1993 Major Subject: Aerospace Engineering TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA...

  4. Fractal Dimensions of a Weakly Clustered Distribution and the Scale of Homogeneity

    E-Print Network [OSTI]

    J. S. Bagla; Jaswant Yadav; T. R. Seshadri

    2008-08-04T23:59:59.000Z

    Homogeneity and isotropy of the universe at sufficiently large scales is a fundamental premise on which modern cosmology is based. Fractal dimensions of matter distribution is a parameter that can be used to test the hypothesis of homogeneity. In this method, galaxies are used as tracers of the distribution of matter and samples derived from various galaxy redshift surveys have been used to determine the scale of homogeneity in the Universe. Ideally, for homogeneity, the distribution should be a mono-fractal with the fractal dimension equal to the ambient dimension. While this ideal definition is true for infinitely large point sets, this may not be realised as in practice, we have only a finite point set. The correct benchmark for realistic data sets is a homogeneous distribution of a finite number of points and this should be used in place of the mathematically defined fractal dimension for infinite number of points (D) as a requirement for approach towards homogeneity. We derive the expected fractal dimension for a homogeneous distribution of a finite number of points. We show that for sufficiently large data sets the expected fractal dimension approaches D in absence of clustering. It is also important to take the weak, but non-zero amplitude of clustering at very large scales into account. In this paper we also compute the expected fractal dimension for a finite point set that is weakly clustered. Clustering introduces departures in the Fractal dimensions from D and in most situations the departures are small if the amplitude of clustering is small. Features in the two point correlation function, like those introduced by Baryon Acoustic Oscillations (BAO) can lead to non-trivial variations in the Fractal dimensions where the amplitude of clustering and deviations from D are no longer related in a monotonic manner.

  5. X-ray Crystallographic Studies of Substrate Binding to Aristolochene Synthase Suggest a Metal Ion Binding Sequence for Catalysis

    SciTech Connect (OSTI)

    Shishova,E.; Yu, F.; Miller, D.; Faraldos, J.; Zhao, Y.; Coates, R.; Allemann, R.; Cane, D.; Christianson, D.

    2008-01-01T23:59:59.000Z

    The universal sesquiterpene precursor, farnesyl diphosphate (FPP), is cyclized in an Mg2+-dependent reaction catalyzed by the tetrameric aristolochene synthase from Aspergillus terreus to form the bicyclic hydrocarbon aristolochene and a pyrophosphate anion (PPi) coproduct. The 2.1- Angstroms resolution crystal structure determined from crystals soaked with FPP reveals the binding of intact FPP to monomers A-C, and the binding of PPi and Mg2+B to monomer D. The 1.89- Angstroms resolution structure of the complex with 2-fluorofarnesyl diphosphate (2F-FPP) reveals 2F-FPP binding to all subunits of the tetramer, with Mg2+Baccompanying the binding of this analogue only in monomer D. All monomers adopt open activesite conformations in these complexes, but slight structural changes in monomers C and D of each complex reflect the very initial stages of a conformational transition to the closed state. Finally, the 2.4- Angstroms resolution structure of the complex with 12,13-difluorofarnesyl diphosphate (DF-FPP) reveals the binding of intact DF-FPP to monomers A-C in the open conformation and the binding of PPi, Mg2+B, and Mg2+C to monomer D in a predominantly closed conformation. Taken together, these structures provide 12 independent 'snapshots' of substrate or product complexes that suggest a possible sequence for metal ion binding and conformational changes required for catalysis.

  6. A stochastic analysis of steady and transient heat conduction in random media using a homogenization approach

    SciTech Connect (OSTI)

    Zhijie Xu

    2014-07-01T23:59:59.000Z

    We present a new stochastic analysis for steady and transient one-dimensional heat conduction problem based on the homogenization approach. Thermal conductivity is assumed to be a random field K consisting of random variables of a total number N. Both steady and transient solutions T are expressed in terms of the homogenized solution (symbol) and its spatial derivatives (equation), where homogenized solution (symbol) is obtained by solving the homogenized equation with effective thermal conductivity. Both mean and variance of stochastic solutions can be obtained analytically for K field consisting of independent identically distributed (i.i.d) random variables. The mean and variance of T are shown to be dependent only on the mean and variance of these i.i.d variables, not the particular form of probability distribution function of i.i.d variables. Variance of temperature field T can be separated into two contributions: the ensemble contribution (through the homogenized temperature (symbol)); and the configurational contribution (through the random variable Ln(x)Ln(x)). The configurational contribution is shown to be proportional to the local gradient of (symbol). Large uncertainty of T field was found at locations with large gradient of (symbol) due to the significant configurational contributions at these locations. Numerical simulations were implemented based on a direct Monte Carlo method and good agreement is obtained between numerical Monte Carlo results and the proposed stochastic analysis.

  7. Tracking topic birth and death in LDA.

    SciTech Connect (OSTI)

    Wilson, Andrew T.; Robinson, David Gerald

    2011-09-01T23:59:59.000Z

    Most topic modeling algorithms that address the evolution of documents over time use the same number of topics at all times. This obscures the common occurrence in the data where new subjects arise and old ones diminish or disappear entirely. We propose an algorithm to model the birth and death of topics within an LDA-like framework. The user selects an initial number of topics, after which new topics are created and retired without further supervision. Our approach also accommodates many of the acceleration and parallelization schemes developed in recent years for standard LDA. In recent years, topic modeling algorithms such as latent semantic analysis (LSA)[17], latent Dirichlet allocation (LDA)[10] and their descendants have offered a powerful way to explore and interrogate corpora far too large for any human to grasp without assistance. Using such algorithms we are able to search for similar documents, model and track the volume of topics over time, search for correlated topics or model them with a hierarchy. Most of these algorithms are intended for use with static corpora where the number of documents and the size of the vocabulary are known in advance. Moreover, almost all current topic modeling algorithms fix the number of topics as one of the input parameters and keep it fixed across the entire corpus. While this is appropriate for static corpora, it becomes a serious handicap when analyzing time-varying data sets where topics come and go as a matter of course. This is doubly true for online algorithms that may not have the option of revising earlier results in light of new data. To be sure, these algorithms will account for changing data one way or another, but without the ability to adapt to structural changes such as entirely new topics they may do so in counterintuitive ways.

  8. A cell model for homogenization of fiber-reinforced composites: General theory and nonlinear elasticity effects

    SciTech Connect (OSTI)

    Aidun, J.B.; Addessio, F.L.

    1995-11-01T23:59:59.000Z

    The theoretical basis of the homogenization technique developed by Aboudi is presented and assessed. Given the constitutive relations of the constituents, this technique provides an equivalent, homogeneous, constitutive model of unidirectional, continuous-fiber-reinforced composites. The expressions that comprise the first-order version of the technique are given special attention as this treatment has considerable practical value. Nonlinear elasticity effects are added to it. This extension increases the accuracy of numerical simulations of high strain-rate loadings. It is particularly important for any dynamic loading in which shock waves might be produced, including crash safety, armor, and munitions applications. Examples illustrate that elastic nonlinearity can make substantial contributions at strains of only a few per cent. These contributions are greatest during post-yield inelastic deformation. The micromechanics-based homogenization technique is shown to facilitate use of an efficient approximate treatment of elastic nonlinearity in composites with isotropic matrix materials.

  9. Homogenous charge compression ignition engine having a cylinder including a high compression space

    DOE Patents [OSTI]

    Agama, Jorge R.; Fiveland, Scott B.; Maloney, Ronald P.; Faletti, James J.; Clarke, John M.

    2003-12-30T23:59:59.000Z

    The present invention relates generally to the field of homogeneous charge compression engines. In these engines, fuel is injected upstream or directly into the cylinder when the power piston is relatively close to its bottom dead center position. The fuel mixes with air in the cylinder as the power piston advances to create a relatively lean homogeneous mixture that preferably ignites when the power piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. Thus, the present invention divides the homogeneous charge between a controlled volume higher compression space and a lower compression space to better control the start of ignition.

  10. adenocarcinoma: Topics by E-print Network

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

    Page Previous Page 1 2 3 4 5 6 7 8 9 Next Page Last Page Topic Index 41 ??? ??? Helicobacter pylori ?? MALT ??? ??? ??? ??? ???...

  11. adenocarcinomas: Topics by E-print Network

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

    Page Previous Page 1 2 3 4 5 6 7 8 9 Next Page Last Page Topic Index 41 ??? ??? Helicobacter pylori ?? MALT ??? ??? ??? ??? ???...

  12. acrolein: Topics by E-print Network

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

    acrolein First Page Previous Page 1 2 Next Page Last Page Topic Index 1 Original article Mechanisms of resistance to acrolein Physics Websites Summary: Original article Mechanisms...

  13. Renewable Energy Project Development: Advanced Concept Topics

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

    Concept Topics An Introduction to Risk, Tribal Roles, and Support Policies in the Renewable Energy Project Development Process Course Outline What we will cover... About the...

  14. A plasma needle for generating homogeneous discharge in atmospheric pressure air

    SciTech Connect (OSTI)

    Li Xuechen; Yuan Ning; Jia Pengying; Chen Junying [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

    2010-09-15T23:59:59.000Z

    Homogeneous discharge in air is often considered to be the ultimate low-temperature atmospheric pressure plasmas for industrial applications. In this paper, we present a method whereby stable homogeneous discharge in open air can be generated by a simple plasma needle. The discharge mechanism is discussed based on the spatially resolved light emission waveforms from the plasma. Optical emission spectroscopy is used to determine electron energy and rotational temperature, and results indicate that both electron energy and rotational temperature increase with increasing the applied voltage. The results are analyzed qualitatively based on the discharge mechanism.

  15. On the Cosmological Origin of the Homogeneous Scalar Field in Unified Theories

    E-Print Network [OSTI]

    V. N. Pervushin; V. I Smirichinski

    1997-04-28T23:59:59.000Z

    We consider the possibility of describing the Higgs effect in unified theories without the Higgs potential in the presence of the Einstein gravity with the conformal gravity-scalar coupling under the assumption of homogeneous matter distribution. The scalar field values can be found from the Friedmann equations for the homogeneous Universe. The considered cosmological mechanism solves the vacuum density problem (we got $\\rho_\\phi^{Cosmic}=10^{-34}\\rho_{cr}$ instead of $\\rho_\\phi^{Higgs}=10^{54}\\rho_{cr}$),and exludes the monopole creation and the domain walls.

  16. Two stroke homogenous charge compression ignition engine with pulsed air supplier

    DOE Patents [OSTI]

    Clarke, John M. (Chillicothe, IL)

    2003-08-05T23:59:59.000Z

    A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

  17. Enhancement of crystal homogeneity of protein crystals under application of an external alternating current electric field

    SciTech Connect (OSTI)

    Koizumi, H.; Uda, S.; Fujiwara, K.; Nozawa, J. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Tachibana, M. [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0027 (Japan); Kojima, K. [Department of Education, Yokohama Soei University, 1 Miho-tyou, Midori-ku, Yokohama, 226-0015 (Japan)

    2014-10-06T23:59:59.000Z

    X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. The crystal quality was assessed by the full width at half maximum (FWHM) value for each rocking curve. For two-dimensional maps of the FWHMs measured on the 440 and the 12 12 0 reflection, the crystal homogeneity was improved under application of an external electric field at 1 MHz, compared with that without. In particular, the significant improvement of the crystal homogeneity was observed for the 12 12 0 reflection.

  18. WTP Communications Strategy Discussion Topics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1DOE Awards ContractRebuttalCaseDiscussion Topics

  19. (Editor), Modern Aspects of Electrochemistry : 22 1950,

    E-Print Network [OSTI]

    , 2006-2007 Journal of Applied Electrochemistry, Guest Editor, 2008 Catalysis Today, Guest Editor, 2009, Associate Editor, 1999-2004 Solid State Ionics, Guest Editor, 1999-2000 Topics in Catalysis, Guest Editor Topics in Catalysis Catalysis Letters Ionics Journal of New Materials for Electrochemical Systems

  20. Approved Module Information for CH3115, 2014/5 Module Title/Name: Inorganic Chemistry III Module Code: CH3115

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Code: CH3115 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module is provided. The fields of Homogeneous Catalysis and Heterogeneous Catalysis are introduced and basic aspects homogeneous and heterogenous catalytic process), hydroformylation (homogeneous catalysis), ammonia synthesis

  1. Structural Basis for Catalysis of a Tetrameric Class IIa Fructose 1,6-Bisphosphate Aldolase from Mycobacterium tuberculosis

    SciTech Connect (OSTI)

    Pegan, Scott D.; Ruskseree, Kamolchanok; Franzblau, Scott G.; Mesecar, Andrew D. ((NSTDC)); ((UIC))

    2009-03-04T23:59:59.000Z

    Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), currently infects one-third of the world's population in its latent form. The emergence of multidrug-resistant and extensive drug-resistant strains has highlighted the need for new pharmacological targets within M. tuberculosis. The class IIa fructose 1,6-bisphosphate aldolase (FBA) enzyme from M. tuberculosis (MtFBA) has been proposed as one such target since it is upregulated in latent TB. Since the structure of MtFBA has not been determined and there is little information available on its reaction mechanism, we sought to determine the X-ray structure of MtFBA in complex with its substrates. By lowering the pH of the enzyme in the crystalline state, we were able to determine a series of high-resolution X-ray structures of MtFBA bound to dihydroxyacetone phosphate, glyceraldehyde 3-phosphate, and fructose 1,6-bisphosphate at 1.5, 2.1, and 1.3 {angstrom}, respectively. Through these structures, it was discovered that MtFBA belongs to a novel tetrameric class of type IIa FBAs. The molecular details at the interface of the tetramer revealed important information for better predictability of the quaternary structures among the FBAs based on their primary sequences. These X-ray structures also provide interesting and new details on the reaction mechanism of class II FBAs. Substrates and products were observed in geometries poised for catalysis; in addition, unexpectedly, the hydroxyl-enolate intermediate of dihydroxyacetone phosphate was also captured and resolved structurally. These concise new details offer a better understanding of the reaction mechanisms for FBAs in general and provide a structural basis for inhibitor design efforts aimed at this class of enzymes.

  2. J. Phys. I FYance 7 (1997) 1487-1498 NOVEMBER1997, PAGE 1487 A Simple Method to Compute the Response of Non-Homogeneous

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1997-01-01T23:59:59.000Z

    the Response of Non-Homogeneous and Irregular Interfaces: Electrodes and Membranes M. Filoche (*) and B

  3. Small Business Innovation Research (SBIR) FY 2014 Phase I topics...

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

    (SBIR) FY 2014 Phase I topics for the Funding Opportunity Announcement (FOA). Small Business Innovation Research (SBIR) FY 2014 Phase I topics for the Funding Opportunity...

  4. List of Topics for Interagency Performance & Risk Assessment...

    Energy Savers [EERE]

    List of Topics for Interagency Performance & Risk Assessment Community of Practice (P&RA CoP) Discussion List of Topics for Interagency Performance & Risk Assessment Community of...

  5. TEC Working Group Topic Groups Archives Communications Meeting...

    Office of Environmental Management (EM)

    TEC Working Group Topic Groups Archives Communications Conference Call Summaries TEC Meeting Summaries - January 1997 TEC Working Group Topic Groups Tribal Conference Call...

  6. attenuates hyperhomocysteinemia-induced cardiomyocytic: Topics...

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

    and borehole acoustic models. The validity of the scheme is established using a 3D homogenous isotropic ... Krasovec, Mary L. 2003-01-01 29 THE ATTENUATED RAY TRANSFORM...

  7. attenuates lipopolysaccharide-induced inflammatory: Topics by...

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

    and borehole acoustic models. The validity of the scheme is established using a 3D homogenous isotropic ... Krasovec, Mary L. 2003-01-01 37 THE ATTENUATED RAY TRANSFORM...

  8. Recent Topics in Formal Epistemology [ Home ] [ Syllabus

    E-Print Network [OSTI]

    Fitelson, Branden

    Recent Topics in Formal Epistemology [ Home ] [ Syllabus ] Professor Time & Place Branden Fitelson as the semester unfolds... 09/07/11: No readings for this week. I'm just going over the syllabus (and a few other Epistemology: Syllabus http://fitelson.org/topics/syllabus.html 1 of 2 9/6/11 1:40 AM #12;09/14/11: No meeting

  9. Supervised topic models David M. Blei

    E-Print Network [OSTI]

    Blei, David M.

    Supervised topic models David M. Blei Department of Computer Science Princeton University Princeton, NJ blei@cs.princeton.edu Jon D. McAuliffe Department of Statistics University of Pennsylvania analysis, McCallum et al. developed a joint topic model for words and categories [8], and Blei and Jordan

  10. Gaussian Process Topic Models Amrudin Agovic

    E-Print Network [OSTI]

    Banerjee, Arindam

    ) [Blei et al.(2003)] and its variants have proven useful and effective. Such topic models allow mixed) [Blei and Lafferty(2006)] were proposed to address this issue. Instead of a Dirichlet prior, CTMs use link struc- ture among documents [Chang and Blei(2009)], exist- ing topic models, including CTM

  11. Topics in Representation Theory: The Heisenberg Algebra

    E-Print Network [OSTI]

    Woit, Peter

    Topics in Representation Theory: The Heisenberg Algebra We'll now turn to a topic which is a precise analog of the previous discussion of the Clifford algebra and spinor representations. By replacing a new algebra, the Heisenberg algebra. The group of automor- phism of this algebra is now a symplectic

  12. Plasmon excitations in homogeneous neutron star matter. M. Baldo and C. Ducoin

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Plasmon excitations in homogeneous neutron star matter. M. Baldo and C. Ducoin Dipartimento di a rich structure at different energy. The genuine plasmon mode is pushed at high energy and it contains. The plasmon is undamped for not too large momentum and is expected to be hardly affected by the nuclear

  13. Modelling by homogenization of the long term rock dissolution and geomechanical effects

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Modelling by homogenization of the long term rock dissolution and geomechanical effects Jolanta modifications of the hydrodynamical as well as geomechanical properties of the reservoir. The long-term safety the modelling of long term geomechanical effects related to CO2 storage are proposed. Of special interest

  14. Coal Segregation Control for Meeting Homogeneity Z. Huang, R. Kumar J. Yingling, J. Sottile

    E-Print Network [OSTI]

    Kumar, Ratnesh

    Coal Segregation Control for Meeting Homogeneity Standards Z. Huang, R. Kumar J. Yingling, J were developed to control coal segre- gation to meet ash targets over large coal batches (e. g., a unit train of coal) while realizing high yields and economic savings. We have extended this work to address

  15. Water vapor transport in the vicinity of imbibing saline plumes: Homogeneous and layered unsaturated porous media

    E-Print Network [OSTI]

    Weisbrod, Noam

    solutions (brines) were applied as point sources to the surface of homogenous packs of prewetted silica sand vapor transport from the residually saturated sand into the imbibing brine was observed in all sand grades and geometries. Pure water applied to sand prewetted with brine migrated into the surrounding

  16. Rate constants for the homogeneous gas-phase Al/HCl combustion chemistry

    E-Print Network [OSTI]

    Swihart, Mark T.

    Rate constants for the homogeneous gas-phase Al/HCl combustion chemistry Mark T. Swiharta Engineering, University at Buffalo (SUNY), Buffalo, NY 14260-4200, USA b Laboratoire de Combustion et Syste Orleans cedex 2, France c Laboratoire de Combustion et Syste`mes Re´actifs (LCSR), CNRS, 1C, av. de la

  17. Spatial homogenization of thermal feedback regions in Monte Carlo reactor calculations

    SciTech Connect (OSTI)

    Hanna, B. R.; Gill, D. F.; Griesheimer, D. P. [Bertis Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P.O. Box 79, West Mifflin, PA 15122 (United States)

    2012-07-01T23:59:59.000Z

    An integrated thermal-hydraulic feedback module has previously been developed for the Monte Carlo transport solver, MC21. The module incorporates a flexible input format that allows the user to describe heat transfer and coolant flow paths within the geometric model at any level of spatial detail desired. The effect that the varying levels of spatial homogenization of thermal regions has on the accuracy of the Monte Carlo simulations is examined in this study. Six thermal feedback mappings are constructed from the same geometric model of the Calvert Cliffs core. The spatial homogenization of the thermal regions is varied, giving each scheme a different level of detail, and the adequacy of the spatial homogenization is determined based on the eigenvalue produced by each Monte Carlo calculation. The purpose of these numerical experiments is to determine the level of detail necessarily to accurately capture the thermal feedback effect on reactivity. Several different core models are considered: axial-flow only, axial and lateral flow, asymmetry due to control rod insertion, and fuel heating (temperature -dependent cross sections). The thermal results generated by the MC21 thermal feedback module are consistent with expectations. Based upon the numerical experiments conducted it is concluded that the amount of spatial detail necessary to accurately capture the feedback effect on reactivity is relatively small. Homogenization at the assembly level for the Calvert Cliffs PWR model results in a similar power defect to that calculated with individual pin-cells modeled as explicit thermal regions. (authors)

  18. Microfluidic Assembly of Homogeneous and Janus Colloid-Filled Hydrogel Granules

    E-Print Network [OSTI]

    Lewis, Jennifer

    Microfluidic Assembly of Homogeneous and Janus Colloid-Filled Hydrogel Granules Robert F. Shepherd 23234 ReceiVed March 21, 2006. In Final Form: August 15, 2006 The microfluidic assembly of colloid.11 A new route to granulation is suggested by the emergence of microfluidic techniques that allow

  19. Security-Aware Resource Allocation for Real-Time Parallel Jobs on Homogeneous

    E-Print Network [OSTI]

    Qin, Xiao

    processing systems [2], med- ical electronics [9], aircraft control [1], and scientific parallel computing [6 a system framework, security overhead, and parallel applications with deadline and security constraintsSecurity-Aware Resource Allocation for Real-Time Parallel Jobs on Homogeneous and Heterogeneous

  20. Wavelet Analysis of the Conditional Vorticity Budget in Fully Developed Homogeneous Isotropic

    E-Print Network [OSTI]

    École Normale Supérieure

    Wavelet Analysis of the Conditional Vorticity Budget in Fully Developed Homogeneous Isotropic. This decomposition is achieved by the Coherent Vorticity Extraction based on orthogonal wavelets. The analysis allows wavelet decomposition. Farge et al. [4] proposed a method to extract the coherent structures out

  1. Wavelet-Based Extraction of Coherent Vortices from High Reynolds Number Homogeneous

    E-Print Network [OSTI]

    École Normale Supérieure

    Wavelet-Based Extraction of Coherent Vortices from High Reynolds Number Homogeneous Isotropic rue Lhomond, 75231 Paris Cedex 05, France farge@lmd.ens.fr Abstract. A wavelet-based method to extract preserve statistics of nonlinear interactions of the total flow over the inertial range. Key words: wavelet

  2. DOI: 10.1002/cssc.201000142 Homogeneous Oxidation Reactions of Propanediols at Low

    E-Print Network [OSTI]

    Iglesia, Enrique

    are consistent with chain propagation processes mediated by oxygen-containing radicals. The high acrolein selectivity in homogeneous 1,3-propane- diol oxidation led us to introduce the acrolein and H2O formed acrolein into acrylic acid with 90% yields (based on propanediol reactants). This com- bined process

  3. ASSESSING THE LIQUEFACTION RISK REDUCTION OF REINFORCED SOILS: A HOMOGENIZATION APPROACH

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    liquefaction risk reduction factor. Then section 4 develops the same evaluation for a cross trench reinforcedASSESSING THE LIQUEFACTION RISK REDUCTION OF REINFORCED SOILS: A HOMOGENIZATION APPROACH Maxime for the reduction of the liquefaction risk, which can be expected from reinforcing the soil by a periodic array

  4. Homogenization of a Conductive, Convective and Radiative Heat Transfer Problem in a Heterogeneous Domain

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -cooled reactor. It is typically made of many prismatic blocks of graphite in which are inserted the nuclear fuel in the homogenization of heat transfer in periodic porous media where the fluid part is made of long thin parallel in the solid part of the domain and by conduction, convection and radiative transfer in the fluid part (the

  5. A Homogenized Free Energy Model for Hysteresis in Thin-film Shape Memory Alloys

    E-Print Network [OSTI]

    A Homogenized Free Energy Model for Hysteresis in Thin-film Shape Memory Alloys Jordan E. Massad1-8205 Abstract Thin-film shape memory alloys (SMAs) have become excellent candidates for mi- croactuator- lustrate aspects of the model through comparison with thin-film SMA superelastic and shape memory effect

  6. FIRSTORDER CORRECTOR FOR THE HOMOGENIZATION OF THE CRITICALITY EIGENVALUE PROBLEM IN THE EVEN PARITY

    E-Print Network [OSTI]

    Bal, Guillaume

    FIRST­ORDER CORRECTOR FOR THE HOMOGENIZATION OF THE CRITICALITY EIGENVALUE PROBLEM IN THE EVEN of the criticality eigenvalue problem for the even parity flux of neutron transport in a domain with isotropic to determine the power distribution of neutrons in nuclear reactors. In the case of a stable reactor, only

  7. Homogenization of regional river dynamics by dams and global biodiversity implications

    E-Print Network [OSTI]

    Poff, N. LeRoy

    Homogenization of regional river dynamics by dams and global biodiversity implications N. Le differ- ences in climate and geology. Extensive construction of dams by humans has greatly dampened to regional-scale environmental templates caused by dams is largely unexplored but of critical conservation

  8. Detailed Analysis and Control Issues of Homogeneous Charge Compression Ignition (HCCI)

    SciTech Connect (OSTI)

    Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Espinosa-Loza, Francisco; Dibble, Robert

    2002-08-25T23:59:59.000Z

    Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work.

  9. Dynamics of Homogeneous Charge Compression Ignition (HCCI) Engines with High Dilution

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Dynamics of Homogeneous Charge Compression Ignition (HCCI) Engines with High Dilution C. J. Chiang (HCCI) engines in light of the cycle-to-cycle thermal feedback due to the high percentage of exhaust temperature is the primary mechanism for con- trolling ignition timing in an HCCI engine, especially when

  10. Sensitivity Analysis of Combustion Timing and Duration of Homogeneous Charge Compression Ignition (HCCI) Engines

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    (HCCI) Engines C. J. Chiang and A. G. Stefanopoulou University of Michigan, Ann Arbor Email: cjchiang of a Homogeneous Charge Com- pression Ignition (HCCI) engine. Qualitative and quantitative information on the individual effects of fuel and exhaust gas recirculation (EGR) on the HCCI combustion is provided. Using

  11. On the critical salt concentrations for particle detachment in homogeneous sand and heterogeneous Hanford sediments

    E-Print Network [OSTI]

    Selker, John

    On the critical salt concentrations for particle detachment in homogeneous sand and heterogeneous June 2004 Abstract One of the mechanisms for sudden particle release is a decrease in groundwater salt concentration to below the critical salt concentration (CSC), where repulsion forces between fine particles

  12. Stability and Performance of Non-Homogeneous Multi-Agent Systems on

    E-Print Network [OSTI]

    Murray, Richard M.

    of interconnected multi-agent systems. The dynamics of the individual agents are not required to be homogeneous the interconnection topology as a graph, in which the single agents are represented by a vertex, while the interaction and with different tools: dissipative theory and linear matrix inequalities in Langbort et al. [2004], edge agreement

  13. Analysis of the finite element heterogeneous multiscale method for nonlinear elliptic homogenization problems.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Analysis of the finite element heterogeneous multiscale method for nonlinear elliptic homogenization problems. Assyr Abdulle and Gilles Vilmart September 28, 2012 Abstract An analysis of the finite finite elements. Op- timal a-priori error estimates are obtained for the H1 and L2 norms, error bounds

  14. FAST AND ROBUST NUMERICAL SOLUTION OF THE RICHARDS EQUATION IN HOMOGENEOUS SOIL

    E-Print Network [OSTI]

    Kornhuber, Ralf

    kr(#(p))(#p - z) in case of a homogeneous soil. Here, p is the unknown water or capillary pressure on# Ã? (0, T ) for a time T > 0 and a domain# # R 3 inhibited by the porous medium. The porosity.e., these parameter functions are fixed on# and describe the relationships in a single soil only. Concrete forms

  15. FAST AND ROBUST NUMERICAL SOLUTION OF THE RICHARDS EQUATION IN HOMOGENEOUS SOIL

    E-Print Network [OSTI]

    Kornhuber, Ralf

    ) in case of a homogeneous soil. Here, p is the unknown water or capillary pressure on Ã? (0, T ) for a time T > 0 and a domain R3 inhibited by the porous medium. The porosity and the hydraulic conductivity the relationships in a single soil only. Concrete forms of these functions have been given by Brooks and Corey [13

  16. COMPUTER PROGRAM FOR ANALYSIS OF THE HOMOGENEITY AND GOODNESS OF FIT OF

    E-Print Network [OSTI]

    from the author. Literature Cited LI, J. C. R. 1959. Introduction to statistical inference. Edward Bros of statistics in biological research. W. H. Freeman and Co., San Franc., 776 p. YaNG. M. Y. Y., AND R. ACOMPUTER PROGRAM FOR ANALYSIS OF THE HOMOGENEITY AND GOODNESS OF FIT OF FREQUENCY DISTRIBUTIONS

  17. Projective re-normalization for improving the behavior of a homogeneous conic linear system

    E-Print Network [OSTI]

    Belloni, Alexandre

    In this paper we study the homogeneous conic system F : Ax = 0, x ? C \\ {0}. We choose a point ¯s ? intC? that serves as a normalizer and consider computational properties of the normalized system F¯s : Ax = 0, ¯sT x = 1, ...

  18. Optimization of the structural Gabor functions in a homogeneous velocity model

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Optimization of the structural Gabor functions in a homogeneous velocity model for a zero-o#11;set functions should be optimized, and the Gabor functions should form a frame. We present a simple attempt functions and the space{wavenumber lattice of their central points are optimized analytically

  19. A Harmonic Approach for Calculating Daily Temperature Normals Constrained by2 Homogenized Monthly Temperature Normals3

    E-Print Network [OSTI]

    1 1 A Harmonic Approach for Calculating Daily Temperature Normals Constrained by2 Homogenized a constrained harmonic technique that forces the daily30 temperature normals to be consistent with the monthly, or harmonic even though the annual march of temperatures for some locations can be highly asymmetric. Here, we

  20. Preprint version -March 7, 2006 REITERATED HOMOGENIZATION OF A CAVITATION PROBLEM

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Preprint version - March 7, 2006 REITERATED HOMOGENIZATION OF A CAVITATION PROBLEM IN THIN FILMS theory: cavitation phenomena and roughness of the surfaces in relative motion: cavitation is defined to describe the behavior of a viscous cavitated flow in the lubrication framework. However, in practical

  1. CKEF: A Cluster-based Key Establishment Framework for homogenous mobile and static

    E-Print Network [OSTI]

    schemes. We develop analytical models and conduct extensive simulations to evaluate the security to clusters. Cluster-based pre-distribution schemes improve network security, scalability, and flexibility on homogenous mo- bile wireless sensor networks (HMWSNs) mandate new sets of security appliances to be friendly

  2. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 15, NO. 2, MARCH 2007 209 Stability Analysis in Homogeneous Charge

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    in Homogeneous Charge Compression Ignition (HCCI) Engines With High Dilution Chia-Jui Chiang and Anna G of homogeneous charge compression ignition (HCCI) en- gines with exhaust dilution. We find conditions under which excursions and, hence, keeping the temperature trajectories within stable regions. Index Terms

  3. Effect of high pressure homogenization on the milk fat globule membrane and its relation with the emulsion stability of milk

    E-Print Network [OSTI]

    Cano Ruiz, Maria Elena

    1996-01-01T23:59:59.000Z

    Milk with 1.5 or 3.0% milk fat was heated at 65'C for 30 min or 85'C for 20 min and homogenized at 0, 30, 60, and 90 MPa. Cream was separated form the homogenized milk using centrifugation at 10,500 x g for 30 min and 20'C with addition of 2 8.6 g...

  4. Tunable Solvents for Homogeneous Catalyst Recycle Jie Lu, Michael J. Lazzaroni, Jason P. Hallett, Andreas S. Bommarius,

    E-Print Network [OSTI]

    Tunable Solvents for Homogeneous Catalyst Recycle Jie Lu, Michael J. Lazzaroni, Jason P. Hallett-0100 A novel class of tunable solvents facilitates recycle of homogeneous catalysts for both economic phase and recycling enzyme-cofactor. Other OATS systems are discussed where the preferential dissolution

  5. Reading Tea Leaves: How Humans Interpret Topic Models

    E-Print Network [OSTI]

    Boyd-Graber, Jordan

    Gerrish Chong Wang David M. Blei NIPS 2009 Dec 9th, 2009 Princeton University Identity Guidelines, Blei Reading Tea Leaves #12;Topic Models in a Nutshell From an input corpus words to topics Forget, Blei Reading Tea Leaves #12;Topic Models in a Nutshell From an input corpus words to topics computer

  6. anakan lagoon java: Topics by E-print Network

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

    Last Page Topic Index 1 Java Java Java Computer Technologies and Information Sciences Websites Summary: Java ...

  7. Superacid catalysis of light hydrocarbon conversion. DOE PETC seventh quarterly progress report, April 1, 1995--July 31, 1995

    SciTech Connect (OSTI)

    Gates, B.C. [Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering and Materials Science

    1996-02-01T23:59:59.000Z

    Iron- and manganese-promoted sulfated zirconia is a catalyst for the conversion of propane, but the rate of conversion of propane is much less than the rate of conversion of butane. Whereas this catalyst appears to be a good candidate for practical, industrial conversion of butane, it appears to lack sufficient activity for practical conversion of propane. The propane conversion data reported here provide excellent insights into the chemistry of the catalytic conversion. Solid and catalysts, namely, sulfated zirconia, iron- and manganese-promoted sulfated zirconia, and USY zeolite, were tested for conversion of propane at 1 atm, 200-450{degrees}C, and propane partial pressures in the range of 0.01-0.05 atm. Both promoted and unpromoted sulfated zirconia were found to be active for conversion of propane into butanes, pentanes, methane, ethane, ethylene, and propylene in the temperature range of 200-350{degrees}C, but catalyst deactivation was rapid. At the higher temperatures, only cracking and dehydrogenation products were observed. In contrast to the zirconia-supported catalysts, USY zeolite was observed to convert propane (into propylene, methane, and ethylene) only at temperatures {ge}400{degrees}C. The initial (5 min on stream) rates of propane conversion in the presence of iron- and manganese-promoted sulfated zirconia, sulfated zirconia, and USY zeolite at 450{degrees}C and 0.01 atm propane partial pressure were 3.3 x 10{sup -8}, 0.3 x 10{sup -8}, and 0.06 x 10{sup -8} mol/(s{center_dot}g), respectively. The product distributions in the temperature range 200-450{degrees}C are those of acid-base catalysis, being similar to what has been observed in superacid solution chemistry at temperatures <0{degrees}C. If propane conversion at 450{degrees}C can be considered as a probe of acid strength of the catalyst, the activity comparison suggests that the promoted sulfated zirconia is a stronger acid than sulfated zirconia, which is a stronger acid than USY zeolite.

  8. Homogeneous spectroscopic parameters for bright planet host stars from the northern hemisphere

    E-Print Network [OSTI]

    Sousa, S G; Mortier, A; Tsantaki, M; Adibekyan, V; Mena, E Delgado; Israelian, G; Rojas-Ayala, B; Neves, V

    2015-01-01T23:59:59.000Z

    Aims. In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods. To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius. Results. We show that the spectroscopic parameters, masses, and radii are generally in good agreement with the values available in online databases of exoplanets. There are some exceptions, especially for the evolved stars. These are analyzed in detail focusing on the effect of the stellar mass on the derived planetary mass. ...

  9. High-frequency homogenization of zero frequency stop band photonic and phononic crystals

    E-Print Network [OSTI]

    Antonakakis, Tryfon; Guenneau, Sebastien

    2013-01-01T23:59:59.000Z

    We present an accurate methodology for representing the physics of waves, for periodic structures, through effective properties for a replacement bulk medium: This is valid even for media with zero frequency stop-bands and where high frequency phenomena dominate. Since the work of Lord Rayleigh in 1892, low frequency (or quasi-static) behaviour has been neatly encapsulated in effective anisotropic media. However such classical homogenization theories break down in the high-frequency or stop band regime. Higher frequency phenomena are of significant importance in photonics (transverse magnetic waves propagating in infinite conducting parallel fibers), phononics (anti-plane shear waves propagating in isotropic elastic materials with inclusions), and platonics (flexural waves propagating in thin-elastic plates with holes). Fortunately, the recently proposed high-frequency homogenization (HFH) theory is only constrained by the knowledge of standing waves in order to asymptotically reconstruct dispersion curves an...

  10. Area of homogeneity of Laves phase in the Ti-V-Fe ternary system

    SciTech Connect (OSTI)

    Prima, S.B.; Tret'yachenko, L.A.

    1987-10-01T23:59:59.000Z

    Alloys the compositions of which correspond to the 33.3% and 50% Ti isoconcentrates were prepared for the experimental investigation from iodide titanium, type VNM-1 vanadium, and carbonyl iron. The alloys were melted in an arc furnace with a nonconsumable tungsten electrode in a protective atmosphere of argon being gettered. The homogenizing annealing was done at 1200 and 1000/sup 0/C (annealing time 50-110 h) depending upon the solidus temperature of the specimens. The data obtained from the results of microstructural, x-ray diffraction, and local x-ray spectral investigations of cast and annealed alloys are shown. The data indicates that vanadium replaces not only iron atoms in TiF/sub 2/ but also titanium atoms so that in the Ti-V-Fe ternary system the area of homogeneity of the TiFe/sub 2/-base phase must have some extent along the isoconcentrates of iron or vanadium.

  11. The performance of 3500 MWth homogeneous and heterogeneous metal fueled core designs

    SciTech Connect (OSTI)

    Turski, R.; Yang, Shi-tien

    1987-11-01T23:59:59.000Z

    Performance parameters are calculated for a representative 3500 MWth homogeneous and a heterogeneous metal fueled reactor design. The equilibrium cycle neutronic characteristics, safety coefficients, control system requirements, and control rod worths are evaluated. The thermal-hydraulic characteristics for both configurations are also compared. The heavy metal fuel loading requirements and neutronic performance characteristics are also evaluated for the uranium startup option. 14 refs., 14 figs., 20 tabs.

  12. Beam Homogeneity Dependence on the Magnetic Filter Field at the IPP Test Facility MANITU

    SciTech Connect (OSTI)

    Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, PO Box 1533, 85740 Garching (Germany)

    2011-09-26T23:59:59.000Z

    The homogeneity of the extracted current density from the large RF driven negative hydrogen ion sources of the ITER neutral beam system is a critical issue for the transmission of the negative ion beam through the accelerator and the beamline components. As a first test, the beam homogeneity at the IPP long pulse test facility MANITU is measured by means of the divergence and the stripping profiles obtained with a spatially resolved Doppler-shift spectroscopy system. Since MANITU is typically operating below the optimum perveance, an increase in the divergence corresponds to a lower local extracted negative ion current density if the extraction voltage is constant. The beam H{sub {alpha}} Doppler-shift spectroscopy is a rather simple tool, as no absolute calibration - both for the wavelength and the emission - is necessary. Even no relative calibration of the different used lines of sight is necessary for divergence and stripping profiles as these quantities can be obtained by the line broadening of the Doppler-shifted peak and the ratio of the integral of the stripping peak to the integral of the Doppler-shifted peak, respectively. The paper describes the H{sub {alpha}} MANITU Doppler-shift spectroscopy system which is now operating routinely and the evaluation methods of the divergence and the stripping profiles. Beam homogeneity measurements are presented for different extraction areas and magnetic filter field configurations both for Hydrogen and Deuterium operation; the results are compared with homogeneity measurements of the source plasma. The stripping loss measurements are compared with model calculations.

  13. Homogeneous piecewise polynomial Lyapunov function for robust stability of uncertain piecewise linear system

    SciTech Connect (OSTI)

    BenAbdallah, Abdallah [Institut superieur d'informatique et multimedia de Sfax BP 242-3021 (Tunisia); Hammami, Mohamed Ali [Faculty of Sciences of Sfax, BP 802-3018 Sfax (Tunisia); Kallel, Jalel [Institut preparatoire aux etudes d'ingenieurs de Sfax BP 1172-3018 (Tunisia)

    2009-03-05T23:59:59.000Z

    In this paper we present some sufficient conditions for the robust stability and stabilization of time invariant uncertain piecewise linear system using homogenous piecewise polynomial Lyapunov function. The proposed conditions are given in terms of linear matrix inequalities which can be numerically solved. An application of the obtained result is given. It consists in resolving the stabilization of piecewise uncertain linear control systems by using a state piecewise linear feedback.

  14. Effect of high pressure homogenization on aqueous phase solvent extraction of lipids from Nannochloris Oculata microalgae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Samarasinghe, Nalin; Fernando, Sandun; Faulkner, William B.

    2012-01-01T23:59:59.000Z

    The ability to extract lipids from high-moisture Nannochloris Oculata algal biomass disrupted with high pressure homogenization was investigated. During the first phase, the effect of high pressure homogenization (system pressure and number of passes) on disrupting aqueous algae (of different concentrations and degree of stress) was investigated. Secondly, the effect of degree of cell wall disruption on the amount of lipids extracted with three solvents, namely: hexane, dichloromethane and chloroform, were compared. Studies reveled that high pressure homogenization is effective on cell disruption while the amount of system pressure being the most significant factor affecting the degree of cell breakage.more »Although the number of passes had some impact, the level of disruption seemed to level-off after a certain number of passes. The study revealed that slightly polar solvents (such as chloroform and dichloromethane) performed better in aqueous-phase lipid extractions as compared to hexane. Also, it was revealed that it was not necessary to disrupt the algal cells completely to achieve appreciable levels of lipid yields. In fact, conditions that exerted only 20% of the cells to completely disrupt, allowed sufficient damage to liberate most of the lipids contained in the remainder of the cells.« less

  15. Effect of high pressure homogenization on aqueous phase solvent extraction of lipids from Nannochloris Oculata microalgae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Samarasinghe, Nalin [Texas A & M Univ., College Station, TX (United States). Dept. of Biological and Agricultural Engineering; Fernando, Sandun [Texas A & M Univ., College Station, TX (United States). Dept. of Biological and Agricultural Engineering; Faulkner, William B. [Texas A & M Univ., College Station, TX (United States). Dept. of Biological and Agricultural Engineering

    2012-01-01T23:59:59.000Z

    The ability to extract lipids from high-moisture Nannochloris Oculata algal biomass disrupted with high pressure homogenization was investigated. During the first phase, the effect of high pressure homogenization (system pressure and number of passes) on disrupting aqueous algae (of different concentrations and degree of stress) was investigated. Secondly, the effect of degree of cell wall disruption on the amount of lipids extracted with three solvents, namely: hexane, dichloromethane and chloroform, were compared. Studies reveled that high pressure homogenization is effective on cell disruption while the amount of system pressure being the most significant factor affecting the degree of cell breakage. Although the number of passes had some impact, the level of disruption seemed to level-off after a certain number of passes. The study revealed that slightly polar solvents (such as chloroform and dichloromethane) performed better in aqueous-phase lipid extractions as compared to hexane. Also, it was revealed that it was not necessary to disrupt the algal cells completely to achieve appreciable levels of lipid yields. In fact, conditions that exerted only 20% of the cells to completely disrupt, allowed sufficient damage to liberate most of the lipids contained in the remainder of the cells.

  16. asphaltenes: Topics by E-print Network

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

    asphaltenes First Page Previous Page 1 2 3 Next Page Last Page Topic Index 1 Asphaltene damage in matrix acidizing Texas A&M University - TxSpace Summary: This work addresses the...

  17. anoxia: Topics by E-print Network

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

    First Page Previous Page 1 2 3 4 5 Next Page Last Page Topic Index 21 Cultural eutrophication, anoxia, and ecosystem recovery in Meretta Lake, High Arctic Canada Geosciences...

  18. a: Topics by E-print Network

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

    13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 141 A cluster theory for a Janus fluid Condensed Matter (arXiv) Summary: Recent Monte Carlo simulations on...

  19. auditing: Topics by E-print Network

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

    Society (ER100PP184ER200PP284) Topics: Personal energy audit, the grid, nuclear, fracking Renewable Energy Websites Summary: Energy and Society (ER100PP184ER200PP284)...

  20. audits: Topics by E-print Network

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

    Society (ER100PP184ER200PP284) Topics: Personal energy audit, the grid, nuclear, fracking Renewable Energy Websites Summary: Energy and Society (ER100PP184ER200PP284)...