Sökning: "attenuation"

Visar resultat 21 - 25 av 408 avhandlingar innehållade ordet attenuation.

1. 21. Online fibre property measurements : foundations for a method based on ultrasound attenuation

   Författare :Yvonne Aitomäki; Richard Challis; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

   Sammanfattning : This thesis presents the foundations of a method for estimating fibre properties of pulp suitable for online application in the pulp and paper industry. In the pulp and paper industry, increased efficiency and greater paper quality control are two of the industry's main objectives. LÄS MER

3. 22. Attenuation of acute inlammatory responses by surface nanotopography

   Författare :Mats Hulander; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gold nanoparticles; nanotopography; gradient nanotopography; immune complement; platelets;

   Sammanfattning : The interaction between biology and non-viable surfaces is crucial for many organisms and cells. For example, bacterial cells need to adhere to mineral surfaces in the soil, plants climb and adhere to walls and marine organisms produce adhesives to cling to underwater rocks etc. LÄS MER

4. 23. Error reduction strategies for quantitative PET with focus on hybrid PET/MRI

   Författare :Elin Wallstén; Anne Larsson; Jan Axelsson; Katrine Riklund; Ronald Boellaard; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron emission tomography; PET; PET MR; PET MRI; medical imaging; partial-volume effect; attenuation correction; radiofysik; radiation physics;

   Sammanfattning : Positron Emission Tomography (PET) is an important tool for detection, staging and follow-up in a wide range of diseases, including cancer and neurological disorders. As a functional imaging tool, PET can visualize biological processes, where positron emitting radioactive isotopes are connected to molecules with different functions in the body. LÄS MER

5. 24. Corrections for improved quantitative accuracy in SPECT and planar scintigraphic imaging

   Författare :Anne Larsson; Lennart Johansson; Katrine Åhlström Riklund; Bertil Axelsson; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Quantitative SPECT; scintigraphic imaging; attenuation correction; scatter correction; collimator-detector response; septal penetration; background correction; Monte Carlo simulation; Radiological physics; Radiofysik;

   Sammanfattning : A quantitative evaluation of single photon emission computed tomography (SPECT) and planar scintigraphic imaging may be valuable for both diagnostic and therapeutic purposes. For an accurate quantification it is usually necessary to correct for attenuation and scatter and in some cases also for septal penetration. LÄS MER

7. 25. Multi-Dimensional Quantitative Laser-based Diagnostics - Development and Practial Applications

   Författare :Rikard Wellander; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Post injection; Structured illumination; Mie scattering; Dense sprays; Extinction coefficient; Signal attenuation; Laser extinction; Multiple scattering; Scattering measurements; Planar laser induced fluorescence; Time resolved; Imaging through turbulent media; Three-dimensional image acquisition; Diesel particulate filter regeneration; Wall impingent; Biodiesel; LII; Large-bore gas Engine; Pre-chamber ignition; Fysicumarkivet A:2014:Wellander;

   Sammanfattning : Laser based optical diagnostic methods are routinely used in combustion research. Many of the more common approaches are based on illuminating a cross-section of the sample with a thin laser sheet. For example, by targeting an electronic transition in a molecule, its concentration within the plane illuminated by the laser sheet can be deduced. LÄS MER