Sökning: "Formation mechanism"

Visar resultat 16 - 20 av 1254 avhandlingar innehållade orden Formation mechanism.

  1. 16. The Many Facets of bicoid Gradient Formation in Drosophila

    Författare :Xiaoli Cai; Stefan Baumgartners grupp Utvecklingsbiologi i invertebrater; []
    Nyckelord :Drosophila; bicoid; gradient formation; ARTS model; cortical microtubule; drug;

    Sammanfattning : In Drosophila, the Bicoid protein servers as paradigm as the first identified morphogen, whose concentration gradient provides the initial positional information in the anterior half of the embryo. There, it differentially activates segmentation genes, in particular the gap genes. LÄS MER

  3. 17. Colloidal suspensions of mesostructured silica

    Författare :Andreas Berggren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; formation mechanism; non-ionic surfactants; silica; inorganic silica; colloidal suspension; control of particle size;

    Sammanfattning : Mesoporous silica is a porous material with walls made of silica and pores in the size range of 2-50 nm. Since the silica most often is amorphous, the material lacks short range order but the pores may be arranged in different structures generating a long-range order. LÄS MER

  4. 18. On the origin and evolution of blue compact galaxies

    Författare :Göran A. Östlin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galaxies - compact; formation; evolution; starburst; interactions; dwarf; photometry; kinematics and dynamics; low surface brightness galaxies; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

    Sammanfattning : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. LÄS MER

  5. 19. 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. 20. Mechanisms of Metal Dusting

    Författare :Peter Szakálos; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; metal dusting; mechanism; driving force; kinetics; high temperature corrosion; carburization; stainlesssteel; Ni-base alloys; iron; alumina formers; FeCrAl; oxidation; carbon nanotubes; discontinuous precipitation; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The primary intention with this Doctoral thesis is to fillin the knowledge gaps and raise the level of understandingregarding the different metal dusting mechanisms in general andexplain the process in detail for high alloyed materials.Considerable effort is put into identifying the driving forcesand elucidating the diffusional processes in metal dusting. LÄS MER