Sökning: "pulsations"

Visar resultat 11 - 15 av 42 avhandlingar innehållade ordet pulsations.

1. 11. Self-diagnosis techniques and their applications to error reduction for ultrasonic flow measurement

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

   Sammanfattning : Flow metering plays a major role in modern life. In the process industry, flow metering is critical in industries ranging from food processing to cosmetics. It is also essential in custody transfer or billing, as flow meters are present in gas pumps and district heating substations. LÄS MER

3. 12. VLF and ULF Waves Associated with Magnetospheric Substorms

   Författare :Andrew Collier; Lars Blomberg; James McKenzie; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Subtorms; Magnetosphere; VLF waves; ULF waves; Space physics; Rymdfysik;

   Sammanfattning : A magnetospheric substorm is manifested in a variety of phenomena observed both in space and on the ground. Two electromagnetic signatures are the Substorm Chorus Event (SCE) and Pi2 pulsations. The SCE is a Very Low Frequency (VLF) radio phenomenon observed on the ground after the onset of the substorm expansion phase. LÄS MER

4. 13. Investigations of Transient Pressure Loading on a High Head Francis Turbine

   Författare :Chirag Trivedi; Gabriel Ciocan; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : This doctoral thesis includes six peer-reviewed publications. Beginning with an extensive literature review, this work discusses the study of turbine performance, investigations of the unsteady pressure loading during transient operations, and consequences at runaway speed. LÄS MER

5. 14. Magnetic and Chemical Structures in Stellar Atmospheres

   Författare :Oleg Kochukhov; Nikolai Piskunov; Georges Michaud; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; chemically peculiar stars; high-resolution spectroscopy; magnetic fields; Doppler imaging; rapidly oscillating Ap stars; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi;

   Sammanfattning : We present an investigation of the magnetic field geometries and inhomogeneous distribution of chemical elements in the atmospheres of peculiar A and B stars. Our study combines high-quality spectroscopic and spectropolarimetric stellar observations with the development and application of novel techniques for theoretical interpretation of the shapes and variability of stellar line profiles. LÄS MER

7. 15. Computation and Analysis of EGR Mixing in Internal Combustion Engine Manifolds

   Författare :Alexander Sakowitz; Laszlo Fuchs; Angelo Onorati; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent Mixing; Large Eddy Simulation; URANS; Internal Combustion Engines; Intake Manifolds; T-junction; Exhaust Gas Recirculation;

   Sammanfattning : This thesis deals with turbulent mixing processes occurring in internal combustion engines, when applying exhaust gas recirculation (EGR). EGR is a very efficient way to reduce emissions of nitrogen oxides (NOx) in internal combustion engines. LÄS MER