Sökning: "linear free energy relationship"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden linear free energy relationship.

  1. 1. Concerted or Stepwise? : β-Elimination, Nucleophilic Substitution, Copper Catalysed Aziridination and Ruthenium Catalysed Transfer Hydrogenation Studied by Kinetic Isotope Effects and Linear Free-Energy Relationships

    Författare :Per Ryberg; Heinz F. Koch; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Kinetic isotope effect; linear free energy relationship; elimination; substitution; aziridination; transfer hydrogenation; Organisk kemi; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis describes the use of kinetic isotope effects, linear free energy relationships and stereochamical studies to distinguish between different mechanistic alternatives and to obtain information about transition state structure.In the first part fluorine and deuterium kinetic isotope effects were determined for the base promoted HF elimination from 4-fluoro-4-(4’-nitrophenyl)butane-2-on. LÄS MER

  3. 2. A Low-Leakage Linear Transverse-Flux Machine for a Free-Piston Generator

    Författare :Waqas Arshad; KTH; []
    Nyckelord :Free-piston generators; linear machines; transverse-flux machines; hybrid vehicles; electrical machines design;

    Sammanfattning : The presented work is about a new low-leakage lineartransverse-flux electrical machine.The machine is dimensionedfor a free-piston generator. The intended application is inseries-hybrid vehicles. The free-piston generator is anintegration of a free-piston combustion engine with a linearelectrical machine. LÄS MER

  4. 3. Efficient Execution Paradigms for Parallel Heterogeneous Architectures

    Författare :Konstantinos Koukos; Stefanos Kaxiras; Margaret Martonosi; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Decoupled Execution; Performance; Energy; DVFS; Compiler Optimizations; Heterogeneous Coherence; Computer Science; Datavetenskap;

    Sammanfattning : This thesis proposes novel, efficient execution-paradigms for parallel heterogeneous architectures. The end of Dennard scaling is threatening the effectiveness of DVFS in future nodes; therefore, new execution paradigms are required to exploit the non-linear relationship between performance and energy efficiency of memory-bound application-regions. LÄS MER

  5. 4. Structure-Reactivity Correlations for Reactions of Palladium(II) and Platinum(IV) Complexes

    Författare :Tiesheng Shi; Kemiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; thiol; l-methionine; maleic acid; carboxylic acid; thioether; platinum IV ; palladium II ; linear free energy relationship; volumes of activation; structure-reactivity correlation; reduction; substitution; equilibria; kinetics; mechanism; glutathione; Animal physiology; Djurfysiologi;

    Sammanfattning : The kinetics and mechanism for substitution reactions on tetraaquapalladium(II) by an extended series of thioethers, a great number of carboxylic acids, and olefins have been studied by use of UV-VIS, stopped-flow, and high-pressure stopped-flow spectrophotometry and NMR spectroscopy. Second-order rate constants k and activation parameters (activation enthalpies, entropies, and volumes) for formation of monodentate 1:1 complexes have been determined. LÄS MER

  7. 5. Fundamental investigation to improve the quality of cold mix asphalt

    Författare :Abdullah Khan; Nicole Kringos; Per Redelius; Amit Bhasin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bitumen; Cold Asphalt Mixtures; Minerals Aggregates; Surface Free Energy; Sorption; Contact Angle; Bitumen Emulsions; Breaking and Coalescence.; Bitumen; kallblandad asfaltmassa; mineraler aggregat; fri ytenergi; sorption; kontaktvinkel; bitumenemulsion; brytning och blandning.; Transportvetenskap; Transport Science;

    Sammanfattning : Cold mix asphalt (CMA) emulsion technology could become an attractive option for the road industry as it offers lower startup and equipment installation costs, energy consumption and environmental impact than traditional alternatives. The adhesion between bitumen and aggregates is influenced by diverse parameters, such as changes in surface free energies of the binder and aggregates or the presence of moisture or dust on the surface of aggregates, mixing temperatures, surface textures (including open porosity), nature of the minerals present and their surface chemical composition, as well as additives in the binder phase. LÄS MER