Sökning: "ultrasonic waves"

Visar resultat 21 - 25 av 35 avhandlingar innehållade orden ultrasonic waves.

1. 21. Ultrasonic measurement technology for characterization of pulp fibre suspensions

   Författare :Torbjörn Löfqvist; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industrial Electronics; Industriell elektronik;

   Sammanfattning : In the papermaking industry, there is a need for sensors to measure the properties of the fibre suspension that determine important parameters in the finished paper. This lack of on-line sensors hampers the development of advanced process control strategies. LÄS MER

3. 22. Acoustic Standing Wave Manipulation of Particles and Cells in Microfluidic Chips

   Författare :Andreas Lenshof; Avdelningen för Biomedicinsk teknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustic particle manipulation; separation; ultrasound; cell handling; particle handling; lab on a chip; Microsystem technology; microfluidics; standing waves;

   Sammanfattning : The rise of MEMS and µTAS techniques has created a whole new family of microfluidic devices for a wide range of chemical and biomedical analyses to be performed on small Lab-on-a-chip platforms. The operations often include small samples of particle or cell suspensions on which separation, mixing, trapping or sorting is performed. LÄS MER

4. 23. Elastic Wave Scattering by Closed Cracks and Thin Flaws - Multiple Scattering and Resonances

   Författare :Arne S. Eriksson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SH-wave; evaluation of materials; direct integral equation; singularity expansion; ultrasonic testing;

   Sammanfattning : In this thesis we study elastic wave scattering by thin flaws and closed cracks, which finds applications in ultrasonic testing and evaluation of materials. First we consider the scattering of an SH-wave by a thin finite elastic layer between two elastic half-spaces. LÄS MER

5. 24. Modeling of Scattering by Cracks in Anisotropic Solids - Application to Ultrasonic Detection

   Författare :Johan Mattsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; elastic wave; ultrasonics; crack; integral equations; transducer; anisotropy; scattering; nondestructive testing;

   Sammanfattning : Elastodynamic wave scattering in anisotropic solids with application to ultrasonic nondestructive testing (NDT) is treated and mathematically modeled in this thesis. The scatterers are infinite strip-like cracks and the solids are homogeneous and linearly elastic with negligible damping. LÄS MER

7. 25. Non-invasive assessment of dynamic properties in human arteries : with special reference to gestation and diabetes

   Författare :Jie Hu; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Acetylcholine; Adolescents; Aorta; Diameter waveforms; Diameter pulse waves; Echo tracking system; Fetal behavioural state; Fetal breathing movements; Gestational diabetes mellitus; Impending birth; Insulin-dependent diabetes mellitus; Laser Doppler; Microcirculation; Pregnancy; Pulse wave velocity; Vascular endothelium; Vascular stiffness; Ultrasound;

   Sammanfattning : Background: The important role played by the intrinsic properties of central arteries in cardiovascular physiology and pathology has been increasingly recognised. Several circulatory disorders are associated with increased arterial stiffness. LÄS MER