Sökning: "vibration"

Visar resultat 41 - 45 av 524 avhandlingar innehållade ordet vibration.

  1. 41. The impact of railway vibration and noise on sleep

    Författare :Michael Smith; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; railway vibration; noise; sleep disturbance; polysomnography; cardiovascular disease;

    Sammanfattning : Sleep is a vital component of good health, and sleep loss is associated with impaired cognition, decreased psychomotor performance, cardiovascular disease, adverse effects on endocrine and metabolic function, negative mood, impaired memory, and more. A growing burden of freight transportation on global railway networks will likely lead to an increase in nocturnal vibration and noise at nearby dwellings. LÄS MER

  3. 42. High dynamic stiffness nano-structured composites for vibration control : A Study of applications in joint interfaces and machining systems

    Författare :Qilin Fu; Cornel-Mihai Nicolescu; Per Nylén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vibration control; High dynamic stiffness; Metal matrix composite; Nano structures; Plasma enhanced chemical vapour deposition PECVD ; High power impulse magnetron sputtering HiPIMS ; Adiabatic; Machining; Regenerative tool chatter; Production Engineering; Industriell produktion;

    Sammanfattning : Vibration control requires high dynamic stiffness in mechanical structures for a reliable performance under extreme conditions. Dynamic stiffness composes the parameters of stiffness (K) and damping (η) that are usually in a trade-off relationship. This thesis study aims to break the trade-off relationship. LÄS MER

  4. 43. Soil identification by vibration measurements during soil-rock sounding

    Författare :Editha Ehrmanntraut; Stefan Larsson; Jörgen Johansson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ground vibrations; dynamic penetration testing; frequency; seismic test; vibration velocity; in-situ tests; markvibrationer; dynamiska sonderingsmetoder; frekvens; seismiska försök; vibrationshastighet; in-situ-försök; Jord- och bergmekanik; Soil and Rock Mechanics;

    Sammanfattning : Dynamic penetration tests are frequently used as geotechnical site investigation methods. In Sweden, the main reason to choose a dynamic penetration method is to investigatedepth to bedrock, strength and deformation properties of soil, compaction, or pilingdepth. LÄS MER

  5. 44. Towards semi-automation of forestry cranes : automated trajectory planning and active vibration damping

    Författare :Szabolcs Fodor; Leonid Freidovich; Carlos Vázquez; Anton Shiriaev; Torben Ole Andersen; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Forestry; forwarder cranes; semi-automation; slewing actuator; automated trajectory planning; oscillations; inner boom actuator; active vibration damping; frequency estimation; input shaping control technique; H2-optimal control;

    Sammanfattning : Forests represent one of the biggest terrestrial ecosystems of Earth, that can produce important raw renewable materials such as wood with the help of sun, air and water. To efficiently extract these raw materials, the tree harvesting process is highly mechanized in developed countries, meaning that advanced forestry machines are continuously used to fell, to process and to transport the logs and biomass obtained from the forests. LÄS MER

  7. 45. Myocardial infarction and cardiac regulation in relation to vibration exposure

    Författare :Bodil Björ; Per Gustavsson; Umeå universitet; []
    Nyckelord :vibration exposure; myocardial infarction; cardiac regulation; exposure assessment; occupational exposure; epidemiology; cohort study; case-control study; Occupational and Environmental Medicine; arbets- och miljömedicin;

    Sammanfattning : The purpose of this thesis was to assess the possible risk of myocardial infarction in work entailing exposure to vibration, and to study whether there is any relation between short-term exposure to vibration and cardiac regulation. Epidemiological methods were applied to investigate a possible association between occupational exposure to vibration and myocardial infarction. LÄS MER