Sökning: "Excitation Mechanism"

Visar resultat 1 - 5 av 89 avhandlingar innehållade orden Excitation Mechanism.

  1. 1. Numerical Investigation of the Aerodynamic Vibration Excitation of High-Pressure Turbine Rotors

    Författare :Markus Jöcker; KTH; []
    Nyckelord :Aeroelasticity; Aerodynamics; Stator-Rotor Interaction; Excitation Mechanism; Unsteady Flow Computation; Forced Response; High Cycle Fatigue; Turbomachinery; Gas-Turbine; High-Pressure Turbine; Turbopump; CFD; Design;

    Sammanfattning : The design parameters axial gap and stator count of highpressure turbine stages are evaluated numerically towards theirinfluence on the unsteady aerodynamic excitation of rotorblades. Of particular interest is if and how unsteadyaerodynamic considerations in the design could reduce the riskofhigh cycle fatigue (HCF) failures of the turbine rotor. LÄS MER

  3. 2. Physiological aspects of cochlear excitation and neurotransmitter release

    Författare :Wanje Jäger; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Cochlea; cochlear microphonics; summating potential; vibratory response; tetracaine; aspartate; glutarnate; neurotransmitter; noise; hearing loss;

    Sammanfattning : Using an in vitro model of the guinea pig, the temporal bone preparation, cochlear physiology was studied. By perfusion of the scala tympani with oxygenated culture medium, the responses of the hearing organ to sound stimuli were maintained over several hours and the functional state was followed by monitoring the electrophysiological parameters cochlear microphonics (CM) and summating potential (SP). LÄS MER

  4. 3. Conformational and Dynamical Aspects of Conjugated Polymers and Oligomers of Interest for Photoluminescence

    Författare :Mette Grage; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; femtosecond spectroscopy; conformations; anisotropy; excitation transfer; oligothiophene radical cations; MEH-PPV; Conjugated polymers; polythiophene; resonance Raman spectroscopy.; Chemistry; Kemi; Physics; Fysik;

    Sammanfattning : Transient absorption laser spectroscopy and resonance Raman spectrscopy have been used to study conjugated polymers and oligomers. To extract more information the measurements have been compared to computer simulations and calculations. LÄS MER

  5. 4. Epitaxial growth of semiconductor nanowires

    Författare :Ann Persson; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; materialteknik; nanowires; nanostructures; growth mechanism; Materiallära; Material technology; Halvledarfysik; Semiconductory physics; nanoelectronics; Au; VSS; VLS; surface diffusion; band gap engineering; InP; ternary system; GaAs; heterostructures; InAs; CBE; epitaxy;

    Sammanfattning : This thesis describes the results obtained from investigations carried out on epitaxially grown III-V semiconductor nanowires aimed at improving our understanding of and knowledge on the growth mechanism of nanowires. This is important to be able to control their growth, in order to make future applications possible. LÄS MER

  7. 5. Statistical and Dynamical Aspects of Intermediate Energy Nuclear Collisions

    Författare :Roberta Ghetti; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; excitation function.; subthreshold pions; pion production; neutron cross-talk; correlation function; interferometry; intermittency; phase transition; thermal scaling; reducibility; multifragmentation; Heavy ion collisions; intermediate energy; Atomic and molecular physics; Atom- och molekylärfysik; Fysicumarkivet A:1997:Ghetti;

    Sammanfattning : Studies of intermediate energy heavy ion reactions have revealed the existence of a number of reducibility and thermal scaling properties in nuclear multifragmentation. In particular, the probability of emitting n-fragments is reducible to the probability of emitting a single fragment through the binomial distribution. LÄS MER