Sökning: "velocity"

Visar resultat 16 - 20 av 1691 avhandlingar innehållade ordet velocity.

  1. 16. Assessment of active commuting behaviour : walking and bicycling in Greater Stockholm

    Författare :Erik Stigell; Peter Schantz; Andreas Nilsson; Maria Hagströmer; Gymnastik- och idrottshögskolan; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; walking; cycling; commuting; validity; reproducibility; distance; duration; velocity; frequency; seasonality; Sports; Idrott; Samhällsvetenskap Humaniora; Social Sciences Humanities; Sports Science;

    Sammanfattning : Walking and bicycling to work, active commuting, can contribute to sustainable mobility and provide regular health-enhancing physical activity for individuals. Our knowledge of active commuting behaviours in general and in different mode and gender groups in particular is limited. LÄS MER

  3. 17. Novel Technique to Improve High-Velocity Cold Compaction : Processing of Polymer Powders and Polymer-Based Nanocomposite High Performance Components

    Författare :Bruska Azhdar; Bengt Stenberg; Leif Kari; Mikael Rigdahl; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer powders; nanocomposites; high-velocity compaction; high-energy ball milling; Manufacturing engineering; Produktionsteknik;

    Sammanfattning : Compaction of polymer powders and polymer-based nanocomposites by uniaxial high-velocity cold compaction (HVC), by high-energy ball milling (HEBM) and using a novel technique, relaxation assists, was investigated with a focus on the process parameters, the compactibility characteristics, surface morphology and friction. The basic phenomena associated with HVC are explained and the general energy principle is introduced to explain the pull-out phenomenon, springback gradient, delay time, relative time of the pressure wave, and stick-slip phenomenon during the compaction process. LÄS MER

  4. 18. Volumetric MRI measurements of velocity and flow - Accuracy, visualisation and technical improvements

    Författare :Anders Nilsson; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MRI; 4D flow; phase contrast MRI; velocity mapping;

    Sammanfattning : In the last two decades, phase-contrast magnetic resonance imaging (PC-MRI) has evolved from two-dimensional velocity and flow measurements to volumetric, time-resolved depictions of velocity fields (4D PC). The acquisition of time-resolved velocity fields allows flow visualisations that might provide better understanding of the dynamics of the cardiac system. LÄS MER

  5. 19. Hyperemic Brachial Artery Blood Flow Velocity

    Författare :Susann J Järhult; Lars Lind; Johan Sundström; Peter Friberg; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICINE; MEDICIN; Cardiovascular medicine; Kardiovaskulär medicin; Medicinsk vetenskap; Medical Science;

    Sammanfattning : This thesis aims to evaluate the blood flow velocity in the Brachial artery during reactive hyperemia. Primarily to appraise the information it might contain regarding cardiovascular function and cardiovascular risk. LÄS MER

  7. 20. The flow of pulp suspensions

    Författare :Helena Fock; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pulp suspensions; Velocity profile; Concentration profile; Wall layer; Particle image velocimetry; Flow behaviour; Computational fluid dynamics; Ultrasound velocity profiling;

    Sammanfattning : Large quantities of pulp suspensions are handled in the pulp and paper industry and knowledge of their flow behaviour is very important in the design and operation of process equipment. Despite this, there is still a lack of a fundamental understanding of the mechanisms of the pulp suspension flow. LÄS MER