Sökning: "frequency stability"

Visar resultat 16 - 20 av 352 avhandlingar innehållade orden frequency stability.

  1. 16. Low noise frequency combs and injection locking for broadly tunable laser sources and tomography

    Författare :Connor Skehan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relative intensity noise; frequency comb; frequency noise; phase noise; optical injection locking;

    Sammanfattning : Lasers have revolutionized the world of physics by providing a highly coherent source of photons which may be used for a large variety of purposes. Here, we study the noise properties of frequency combs - a special class of frequency stabilized and mutually coherent multi-mode lasers, as well as the optical injection locking of comb tones as a means for low noise amplification and tone selection. LÄS MER

  3. 17. Development and Stability of Antibiotic Resistance

    Författare :Maria Sjölund; Lars Engstrand; Dan Andersson; Pentti Huovinen; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Microbiology; antibiotic resistance; selection; mutation frequency; biological cost of resistance; compensatory evolution; Helicobacter pylori; normal microbiota; Mikrobiologi; Microbiology; immunology; infectious diseases; Mikrobiologi; immunologi; infektionssjukdomar;

    Sammanfattning : Antibiotic resistance is of current concern. Bacteria have become increasingly resistant to commonly used antibiotics and we are facing a growing resistance problem. The present thesis was aimed at studying the impact of antibiotic treatment on pathogenic bacteria as well as on the normal human microbiota, with focus on resistance development. LÄS MER

  4. 18. Extremum Seeking Control : Stability, Accuracy, and Applications

    Författare :Khalid Atta; Ying Tan; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reglerteknik; Control Engineering;

    Sammanfattning : In many applications, there is a variable that indicates the overall performance and that must be maximized, such as the output of a hydro power turbine or a mineral processing plant, or that must be minimized, such as CO2 emissions or the consumption of resources. Extremization of this variable (maximization or minimization) through adjusting the influencing manipulated variables is occasionally required without prior knowledge of the optimal values of the manipulated variables or of the optimized variable. LÄS MER

  5. 19. Frequency response by wind farms in power systems with high wind power penetration

    Författare :Mattias Persson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inertia estimation; frequency control; power system stability; wind power integration; Power system; synthetic inertia;

    Sammanfattning : The integration of variable speed wind turbines (VSWT) in power systems is increasing in order to reduce the emission of green house gases. This increase of power electronic converter interfaced generation causes a decrease of power system inertia, increasing the risk of load shedding and system frequency instability. LÄS MER

  7. 20. Sensitivity and Uncertainty Analysis of BWR Stability

    Författare :Ivan Gajev; Tomas Lefvert; Paolo Vinai; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BWR Stability; Sensitivity; Uncertainty; Engineering physics; Teknisk fysik; SRA - Energy; SRA - Energi;

    Sammanfattning : Best Estimate codes are used for licensing, but with conservative assumptions. It is claimed that the uncertainties are covered by the conservatism of the calculation. LÄS MER