Blar i Faculty of Mathematics and Natural Sciences på emneord "Acoustics"
Viser treff 1-6 av 6
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Collective behaviour of herring during spawning
(Doctoral thesis, 2007-02-02)The thesis focuses on the collective behaviour of Norwegian spring spawning herring (NSS-herring; Clupea harengus L.) in the specific ecological context of reproduction. The major part of the work is based on field research ... -
Improved density measurements of mesopelagic fish and the presence of physonect siphonophores in sound scattering layers, measured with multifrequency acoustics and a stereo camera mounted on a lowered probe
(Master thesis, 2018-12-11)The mesopelagic layer is a massive layer of biomass which stretches from 200-1000 meters depth in almost all locations of the world oceans. These layers are inhabited by many groups of animals, from small zooplankton to ... -
Measurement of non-linear acoustoelastic effect in steel using acoustic resonance
(Doctoral thesis, 2014-09-25)Non-destructive stress measurements of structures are increasingly valued by the industry. Ultrasonic methods have the advantage that acoustic waves propagate with ease through materials, making it possible to probe the ... -
Spatial distribution of Nile perch using acoustic methods
(Master thesis, 2010-08-03)Lake Victoria supports Africa's largest fishery, being Nile perch the main contributor for the fishery revenues. Alerts for decreases in the commercial catches of Nile perch were reported during the mid 1990s. According ... -
The application of CW and FM sonar technology to detect a decrease in air in the swim bladder of Atlantic salmon, measurements and modeling
(Master thesis, 2022-06-01)Salmon lice and poor surface conditions are challenging for salmon aquaculture. A new innovative preventative solution is to submerge the cages below the sea surface to avoid the surface-dwelling infestation of lice larvae. ... -
Underwater Ultrasonic Transducer Technology. Construction, Characterization and Finite-Element Modelling.
(Master thesis, 2022-03-30)The main objective of this thesis is to construct and characterize ultrasonic transducers. The transducers are constructed to get the information needed for finite element simulations with the wanted accuracy since commercial ...