Search for dissertations about: "Oscillation"

Showing result 11 - 15 of 272 swedish dissertations containing the word Oscillation.

  2. 11. Towards Improved Diagnostics and Monitoring in Childhood Asthma : Methodological and Clinical Aspects of Exhaled NO and Forced Oscillation Technique

    Author : Charlotte Heijkenskjöld Rentzhog; Malinovschi Andrei; Lennart Nordvall; Kjell Alving; Lauri Lehtimäki; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; asthma; children; exhaled NO; forced oscillation technique; airway inflammation; small airways; asthma diagnostics; Pediatrik; Pediatrics; Lungmedicin; Lung Medicine;

    Abstract : Background: Asthma is a heterogeneous disease. Diagnosis relies on symptom evaluation and lung function tests using spirometry. Symptoms can be vague. Spirometry is effort-dependent and does not reliably evaluate small airways. READ MORE

  4. 12. Control of Energy Storage Equipped Shunt-connected Converter for Electric Power System Stability Enhancement

    Author : Mebtu Bihonegn Beza; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transient stability.; energy storage; recursive least square RLS ; electromechanical oscillation; Signal estimation technique; static synchronous compensator; power oscillation damping POD ;

    Abstract : Flexible AC Transmission System (FACTS) controllers, both in shunt and series configuration, are widely used in the power system for power flow control, to increase the loading capability of an existing line and to increase the security of the system by enhancing its transient stability. Among the FACTS controllers family, the Static Synchronous Compensator (STATCOM) is a key device for the reinforcement of the stability in an AC power system. READ MORE

  5. 13. Free oscillation rheometry in the assessment of platelet quality

    Author : Nahreen Tynngård; Gösta Berlin; Tomas Lindahl; James AuBuchon; Linköpings universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Coagulation; elasticity; platelets; rheology; transfusion; Transfusion medicine; Transfusionsmedicin;

    Abstract : Platelets play an important role in the haemostatic process in order to seal damaged blood vessels. The platelets form a platelet plug at the damaged area and prevent blood loss. Once the damage to the vessel wall has been covered, the platelets retract the coagulum, to allow the blood to flow freely in the vessel. READ MORE

  6. 14. Impact of Rossby waves on ozone distribution and dynamics of the stratosphere and troposphere

    Author : Grigory Nikulin; Sheila Kirkwood; Ulrike Langematz; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Meteorology; ozone; wave activity; trends; Brewer-Dobson circulation; Rossby waves; Arctic Oscillation; low ozone events; Meteorologi; Meteorology; Meteorologi; Meteorology; meteorologi;

    Abstract : Several physical mechanisms concerning the impact of Rossby waves on ozone distribution and circulation in the stratosphere and troposphere are studied in the thesis.Summertime total ozone variability over Middle Asia and Northern Scandinavia shows similar wave-like behaviour with typical periods of 10-20 days and amplitudes of 20-50 Dobson units. READ MORE

  7. 15. Wind Power - Added Value for Network Operation

    Author : Nayeem Ullah; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; torsional oscillation; reactive power ancillary service; voltage stability; power system simulator.; STATCOM; non-minimum phase system; Variable speed wind turbine; frequency control; sensitivity analysis; transient stability; small-signal stability;

    Abstract : This dissertation deals with the investigation on different value added properties of variable speed wind turbines (VSWT) that stem from the flexible controllability of converter interfaced wind turbines (WT). Improvements in voltage and transient stability of a nearby grid, small-signal stability improvement on the power system, frequency control support for the network operation, as well as thetechnical and the economic issues related to the reactive power ancillary service provision, are among the issues covered. READ MORE