Sökning: "kluster"

Visar resultat 21 - 25 av 87 avhandlingar innehållade ordet kluster.

1. 21. Utveckling av arbetsmiljö och upplevd hälsa : en longitudinell undersökning av anställda i kraftindustrin

   Författare :Rose-Marie Herlin; Jan Johansson Hanse; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Arbetsmiljö; kraftindustrin; utveckling; subjektiv hälsa; muskuloskeletala besvär; psykiska besvär; buller; klusteranalys; regressionsanalys; strukturekvationsmodellering;

   Sammanfattning : I avhandlingen undersöks hur arbetsmiljön påverkar den upplevda hälsoutvecklingen över en nioårsperiod hos 440 elarbetare inom kraftindustrin. Problemet beskrivs utifrån en teoretisk modell över orsakssamband mellan arbetsmiljö och upplevd ohälsa. En ytterligare målsättning är att jämföra data av olika subjektivitetsgrad. LÄS MER

3. 22. Cluster-Based Catalysts for Asymmetric Synthesis

   Författare :Viktor Moberg; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Metallorganisk kemi; Organometallic chemistry; Oorganisk kemi; Inorganic chemistry; Kemi; Chemistry; hydride; cobalt; osmium; ruthenium; cyclocarbonylation; Pauson-Khand; carbonyl cluster; asymmetric hydrogenation;

   Sammanfattning : In this work, the synthesis and characterisation of new low-valence transition metal carbonyl clusters, and an investigation into their viability to act as catalysts/catalyst precursors in asymmetric synthesis, are described. Carbonyl clusters based on ruthenium and osmium have been tested as (pre)catalysts for asymmetric hydrogenation of alpha-unsaturated carboxylic acids, and cobalt carbonyl clusters have been used as (pre)catalysts in (asymmetric) Pauson-Khand synthesis. LÄS MER

4. 23. A study of micro-particles in the dust and melt at different stages of iron and steelmaking

   Författare :Muhammad Nabeel; Andrey Karasev; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Particle size distribution; ironmaking; iron ore pellets; dust generation; mechanical wear; friction; reduction; REM clusters; Electrolytic extraction; cluster size distribution; growth mechanism; collisions; statistical analysis.; Teknisk materialvetenskap; Materials Science and Engineering; Metallurgical process science; Metallurgisk processvetenskap;

   Sammanfattning : The dust particles generated due to mechanical wear of iron ore pellets and clusters formed in molten stainless steel alloyed with rare earth metals (REM) are considered in this study. Firstly, the influence of the characteristics of iron ore pellets, applied load on a pellet bed and partial reduction of the pellets on the size distribution of the generated dust was investigated. LÄS MER

5. 24. High-Resolution Measurement of the 4He(g,n) Reaction in the Giant Resonance Region

   Författare :Björn Nilsson; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tagged photons; photonuclear reactions; liquid helium; neutron detectors; liquid scintillators; giant resonances; angular distributions; differential cross sections; total cross sections; Nuclear physics; Kärnfysik; Fysicumarkivet A:2003:Nilsson;

   Sammanfattning : A comprehensive near-threshold 4He(g,n) absolute cross section measurement has been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 20 < Eg < 45 MeV tagged photons (covering the Giant Dipole Resonance energy region) were directed towards a liquid 4He target, and knocked-out neutrons were detected in a pair of 60 cm x 60 cm vetoed NE213A liquid scintillator arrays. LÄS MER

7. 25. Bank branches and Entrepreneurship : A spatial analysis of new firm formation in Swedish regions and industries in a changing financial landscape

   Författare :Cynthia Sin Tian Ho; Björn Berggren; Mikaela Backman; KTH; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; New firm formation; entrepreneurship; financing; bank branches; proximity; spatial analysis; GWR; Sweden; Business Studies; Företagsekonomi;

   Sammanfattning : The purpose of this thesis is to analyse how bank branch closure has affected the formation of new firms and to explore the varying local relationships between the accessibility of bank branches and new firm formation in 290 Swedish municipalities. In the first paper, the effect of bank branch closure is examined through spatial econometric analysis, in particular, the fixed effects and the random effects spatial panel models. LÄS MER