Sökning: "infrasound"

Visar resultat 1 - 5 av 9 uppsatser innehållade ordet infrasound.

  1. 1. Studies of the PMWE : Polar Mesosphere Winter Echoes

    Master-uppsats, Luleå tekniska universitet/Institutionen för system- och rymdteknik

    Författare :Simon Persson; [2022]
    Nyckelord :Polar; Mesosphere; Winter; Echoes; ESRAD; Infrasound; PMWE; PMSE; Summer; Radar; VHF; MST; MLT; SPE; HSS; Solar; Wind; evanescent; viscosity; FCA; 42;

    Sammanfattning : This Master thesis examines a phenomenon that occurs in the upper polar atmosphere, namely, Polar Mesospheric Winter Echoes, or PMWEs. PMWEs are radar echoes observed by Very High Frequency Mesosphere Stratosphere Troposphere (VHF MST) radar, from altitudes of 60 to 76 km at 7 to 15 UT, in the winter months from the middle of September to the beginning of May. LÄS MER

  3. 2. Experimental optimization and analysis of drying in ifrasound dryer

    Master-uppsats, KTH/Maskinkonstruktion (Inst.)

    Författare :Shreeja-Sivaranjani Natarajan; [2022]
    Nyckelord :Infasound technology; Wheat drying and storage; Drying method; Simulation of drying; Infasound-teknik; Torkning och lagring av vete; Torkningsmetod; Simulering av torkning;

    Sammanfattning : In the agricultural industries drying plays a major role as its very important for grain storage. The selection of the dryer and the method used for drying should be chosen wisely considering the product to be dried with its other factors. LÄS MER

  4. 3. Sound Propagation Through Walls

    Kandidat-uppsats, Uppsala universitet/Avdelningen för beräkningsvetenskap

    Författare :Alexander Berglund; Fredrik Herbai; Jonas Wedén; [2021]
    Nyckelord :acoustics; wave propagation; infrasound; finite difference methods; SBP-SAT; one dimension; analytical calculation; numerical simulation;

    Sammanfattning : Infrasound is undetectable by the human ear and excessive exposure may be a substantial health risk. Low frequency sound propagates through walls with minimal attenuation, making it difficult to avoid. This study interprets the results from both analytical calculations and simulations of pressure waves propagating through a wall in one dimension. LÄS MER

  5. 4. Detecting Signal Corruptions in Voice Recordings for Speech Therapy

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Helmer Nylén; [2021]
    Nyckelord :Noise; Classification algorithms; Audio recording; Machine learning; Acoustic signal processing; Störning; Klassificeringsalgoritmer; Ljudinspelning; Maskininlärning; Akustisk signalbehandling;

    Sammanfattning : When recording voice samples from a patient in speech therapy the quality of the recording may be affected by different signal corruptions, for example background noise or clipping. The equipment and expertise required to identify small disturbances are not always present at smaller clinics. LÄS MER

  7. 5. Possibility of enhancing algae drying by integrating infrasound.

    Master-uppsats, KTH/Industriell ekologi

    Författare :YINGZI SANG; [2017]
    Nyckelord :Algae storage and preservation; Infrasound; Drying method; Sustainable;

    Sammanfattning : With the aim of designing an infrasound-integrated technology which can enhance the algae drying performance, this thesis provided the theoretical possibility of using infrasound as an algae dehydration technology. To test the relation between algae drying speed and other three parameters namely sound frequency, sound pressure and sample mass, four major experimental groups including initial experiments and core experiments with fifteen sub-experimental groups are designed. LÄS MER