Sökning: "Initiation position"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden Initiation position.

  1. 1. Characterizations of ground flashes from tropic to northern region

    Författare :Zikri Abadi Baharudin; Vernon Cooray; Mahbubur Rahman; Farhad Rachidi; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Positive negative cloud-to-ground lightning flashes; Initiation position; slow field changes; close ground flashes; preliminary breakdown process; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Sammanfattning : This thesis portrays new information concerning the cloud-to-ground (CG) lightning flashes or ground flashes produced by thunderclouds. It emphasizes the importance of characterizing lightning studies as the relationship between lightning mechanisms, and of incorporating the influence of geographical location, latitude and storm type. LÄS MER

  3. 2. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

    Författare :Jonas Ringsberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

    Sammanfattning : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. LÄS MER

  4. 3. Gas Metal Arc Melt Pool Modelling : Effect of welding position and electromagnetic force mode

    Författare :Pradip Aryal; Isabelle Choquet; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gas metal arc welding; Gravitational force; Substrate orientation; Electromagnetic force modelling; Free surface deformation; Computational Fluid Dynamics; OpenFOAM; Gasmetallbågsvetsning; Gravitation; Svetsläge; Elektromagnetisk kraftmodellering; Smältytans rörelser; Computational Fluid Dynamics; OpenFOAM; Production Technology; Produktionsteknik;

    Sammanfattning : Gas metal arc is a high-efficiency and widely used heat source for metal processing applied predominantly in welding and additive manufacturing. In this study, it was applied to welding. LÄS MER

  5. 4. Socially structured health behaviors : Studies of social inequality in adolescent and young adult physical activity, alcohol consumption, and smoking in Sweden

    Författare :Laura Wells; Viveca Östberg; Magnus Nermo; Olof Östergren; Curt Hagquist; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; health behaviors; physical activity; alcohol consumption; smoking; health lifestyle; social inequalities; socioeconomic position; education; school performance; adolescents; young adults; life course perspective; folkhälsovetenskap; Public Health Sciences;

    Sammanfattning : Health behaviors contribute to the Swedish national disease burden and to social inequalities in health. This thesis aims to increase our knowledge of whether, when, and how health behaviors become socially structured during early life in Sweden. LÄS MER

  7. 5. Rational and combinatorial genetic engineering approaches for improved recombinant protein production and purification

    Författare :Nina Bandmann; Per-Åke Nygren; Helena Berglund; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aqueous two-phase system; combinatorial library; expression vector; flow cytometry; fusion tag; partitioning; peptide library; phage display; recombinant proteins; ribosomal binding site; translation initiation; Bioengineering; Bioteknik;

    Sammanfattning : The bacterium Escherichia coli (E. coli) is in many situations an ideal host for production of recombinant proteins, since it generally provides a rapid and economical means to achieve sufficiently high product quantities. LÄS MER