Essays about: "acoustic reflector"

Found 5 essays containing the words acoustic reflector.

1. 1. Making nets more acoustically visible : Floats as passive mitigation measures to reduce bycatch of harbour porpoise (Phocoena phocoena) in gillnets

   University essay from SLU/Dept. Of Aquatic Resources

   Author : Frida Rosshagen; [2023]
   Keywords : toothed whales; harbour porpoise; Phocoena phocoena; incidental capture; bycatch; fisheries; fishing gear; ; gillnet; mitigation; reduction; low-cost; passive acoustic reflector; float;

   Abstract : Incidental capture in fishing gear is today affecting at least 112 marine mammal species worldwide and for many smaller toothed whale species (Odontocete), gillnets are considered to be the largest problem. Although some effective mitigation measures exists, these are often context specific and many might be hard to implement due to reasons such as high costs and maintenance. READ MORE

3. 2. Pearls as bycatch mitigation strategy for Harbour porpoise (Phoecena phoecena)

   University essay from SLU/Dept. Of Aquatic Resources

   Author : Sara Gustafsson; [2020]
   Keywords : harbour porpoise; bycatch mitigation; acoustic reflector; pearl; gillnet; F-POD; click rate; click behaviour; inter-click-interval; terminal buzz; diel phase; GAM;

   Abstract : One of the major threats to harbour porpoise population sustainability is thought to be the high incidence of bycatch specifically in gillnets. This study aims to examine the use of acrylic class pearls developed in an earlier study as acoustic reflectors on gillnets in an effort to increase their visibility to echolocating harbour porpoises in the lumpsucker fishery in Kattegatt. READ MORE

4. 3. Acoustic Characterization of the Cellulose-coated Perfluorocarbon Droplets based on Phase Velocity Measurements

   University essay from KTH/Skolan för kemi, bioteknologi och hälsa (CBH)

   Author : Emma Lindroth; [2020]
   Keywords : Ultrasound; Droplets; Contrast agent; Cellulose; Perfluorocarbon; Acoustic characterization; Non-destructive evaluation; Phase velocity; Bulk modulus; Compressibility;

   Abstract : Today, microbubbles are one of the most commonly used ultrasound contrast agents, since their high compressibility results in a strongly scattered signal. Despite this advantage, microbubbles experience limitations by the decreased stability and large diameter. READ MORE

5. 4. Petrophysical and GeophysicalAnalysis of Ordovician Limestone Mounds for the Purpose of Hydrocarbon Reservoir Exploration : Petrofysisk och geofysisk analys av Ordoviciska kalkstensstrukturer för hydrokarbonprospektering

   University essay from Uppsala universitet/Institutionen för geovetenskaper

   Author : Felix Söderberg; [2015]
   Keywords : Gotland; hydrocarbons; Ordovicium; mounds; reefal structures; Hydrokarbon; revstruktur; slamhög; ordovicium; Gotland;

   Abstract : Gripen Oil & Gas have extended their prospecting license on Gotland to the north end of the island to search for potential hydrocarbon reservoirs. Earlier prospecting has shown that limestone mound structures from Ordovicium have high potential as hydrocarbon reservoirs due to their antiformal shape and the petrophysical properties of the limestone. READ MORE

6. 5. Vibro-acoustic analysis of a satellite reflector antenna using FEM

   University essay from Institutionen för fysik

   Author : Johannes Sikström; [2011]
   Keywords : finite element method; FEM; acoustics; vibrations; vibro-acoustic; analysis; NASTRAN; PATRAN; satellite; fluid-structure; fsi; structure-acoustic; random analysis;

   Abstract : The acoustic environment generated during launch is the most demanding structural load case for large, lightweight satellite reflector antennas. The reflector is exposed to extremely high sound pressure levels originating from the structural excitation of the rocket engines and exterior air flow turbulence. READ MORE