Sökning: "frequency selectivity"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden frequency selectivity.

  1. 1. Pitch, loudness and frequency selectivity in low-frequency hearing loss

    Författare :Jonas Brännström; Lund näs- och halssjukdomar Öron-; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; frequency coding; Cochlea; frequency selectivity; hearing fluctuation; inner ear pressure; long-term measurement; Ménière s disease; low-frequency hearing loss; loudness; pitch.;

    Sammanfattning : Patients with Ménière's disease and cochlear hydrops show fluctuating low-frequency hearing loss (FLFHL). At present these changes are followed as patients' subjective reports and occasional measurements. LÄS MER

  3. 2. Optical Frequency Comb Fourier Transform Spectroscopy

    Författare :Alexandra C. Johansson; Aleksandra Foltynowicz; Ove Axner; Jürgen Röpcke; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical frequency comb spectroscopy; Fourier transform; molecular absorption dispersion; fysik; Physics;

    Sammanfattning : Fourier transform spectroscopy (FTS) based on optical frequency combs is an excellent spectroscopic tool as it provides broadband molecular spectra with high spectral resolution and an absolutely calibrated frequency scale. Moreover, the equidistant comb mode structure enables efficient coupling of the comb to enhancement cavities, yielding high detection sensitivity. LÄS MER

  4. 3. Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics

    Författare :Carin H Nilsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; population dynamics; selectivity; Phenotypic plasticity; fitness; Plant ecology; Växtekologi;

    Sammanfattning : Parasitic plants are found in nearly every major terrestrial ecosystem and can be divided into two groups, holoparasites (lacking chlorophyll) and hemiparasites (chlorophyllous). The host-parasite connection is either situated above (stem parasites) or below ground (root parasites). LÄS MER

  5. 4. Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry

    Författare :Aleksandra Foltynowicz; Ove Axner; Weidong Chen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; frequency modulation; cavity enhancement; NICE-OHMS; Laser frequency stabilization; fiber laser; Fabry-Perot cavities; sub-Doppler spectroscopy; trace gas detection; Physics; Fysik; Molecular physics; Molekylfysik; fysik; Physics;

    Sammanfattning : Noise-immune cavity-enhanced optical heterodyne molecular spectro-metry (NICE-OHMS) is one of the most sensitive laser-based absorption techniques. The high sensitivity of NICE-OHMS is obtained by a unique combination of cavity enhancement (for increased interaction length with a sample) with frequency modulation spectrometry (for reduction of noise). LÄS MER

  7. 5. Design of Functional Structures and Measurement Techniques for Electromagnetic Waves

    Författare :Johan Lundgren; Teoretisk elektroteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; functional structures; frequency selective structures; polarization selectivity; metasurface; near-field measurements; antenna measurements; scattering measurement; power density; random media;

    Sammanfattning : Electromagnetic fields exist all around us. Through evolution, nature has developed tools to interact and use these fields, where our eyes are a spectacular example. Humans have a long history of developing structures and objects of their own to alter and interact with these fields. LÄS MER