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Visar resultat 1 - 5 av 229 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Exploring Novel Catalytic Chalcogenide Antioxidants

    Författare :Henrik Johansson; Lars Engman; Helena Grennberg; Troels Skrydstrup; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; antioxidant; tellurium; selenium; catalytic; toxicity; ROS; neutrophil; glutathione peroxidase mimic; macrophage.; Organic chemistry; Organisk kemi; Kemi med inriktning mot organisk kemi; Chemistry with specialization in Organic Chemistry;

    Sammanfattning : This thesis is concerned with the synthesis and evaluation of regenerable chalcogen containing antioxidants. Variously substituted 2,3-dihydrobenzo[b]selenophene-5-ol antioxidants were evaluated in order to gain information about structure/reactivity-relationships. LÄS MER

  3. 2. Catalytic Converters for Automotive Exhaust Applications. Flow Dynamics, Mass Transfer and Optimization

    Författare :Fredrik Ekström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TWC; optimization; exhaust; laboratory reactors; catalytic converter; catalysis; pressure drop; entrance effects; CFD; mass transfer; pulsations; flow distribution;

    Sammanfattning : In order to reduce emissions from vehicles powered by an internal combustion engine, an exhaust aftertreatment system is normally mounted on the engine. This aftertreatment system normally consists of one or several catalytic converters. LÄS MER

  4. 3. Numerical Studies of Wall Effects of Laminar Flames

    Författare :Johan Andrae; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wall effects; laminar premixed flames; Chemkin; boundary layer flow; Chemical engineering; Kemiteknik;

    Sammanfattning : Numerical simulations have been done with the CHEMKINsoftware to study different aspects of wall effects in thecombustion of lean, laminar and premixed flames in anaxisymmetric boundary-layer flow. The importance of the chemical wall effects compared to thethermal wall effects caused by the development of the thermaland velocity boundary layer has been investigated in thereaction zone by using different wall boundary conditions, walltemperatures and fuel/air ratios. LÄS MER

  5. 4. A Study of Catalytic Ignition and Kinetic Phase Transitions

    Författare :Mats Rinnemo; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; catalytic ignition; catalysis; kinetic phase transitions; platinum;

    Sammanfattning : Catalytic ignition and kinetic phase transitions are two critical phenomena which can occur in heterogeneously catalyzed reaction systems. They have in common that the system behavior changes qualitatively when a control parame-ter passes through a critical value. LÄS MER

  7. 5. Atom and Group Transfer Reactions Involving High-valent Iron Complexes

    Författare :Yong Li; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Iron enzymes; high-valent iron intermediates; bio-inspired iron complexes; FeIV=O; FeIV=NR; catalytic reactions; electronic effects; steric restriction.;

    Sammanfattning : Iron enzymes play critical roles in biological oxidation reactions by utilizing highly reactive high-valent iron intermediates, such as FeIV=O, FeV(O)(OH), and FeIV=NR species, for catalytic reactions. These intermediates exhibit remarkable catalytic behavior with high reactivities and high regio- and stereospecificity in various biochemical reactions. LÄS MER