Sökning: "Cylinders"

Visar resultat 11 - 15 av 118 avhandlingar innehållade ordet Cylinders.

1. 11. In-Cylinder Fluid Flow, Fuel Preparation and Combustion in SI Engines - Application of Optical Diagnostics

   Författare :Martin Ekenberg; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laserteknik; vakuumteknik; vibrationer; akustik; Motors and propulsion systems; Motorer; hydraulik; Maskinteknik; PIV; vibration and acoustic engineering; hydraulics; vacuum technology; Mechanical engineering; framdrivningssystem; Laser technology;

   Sammanfattning : In this thesis laser-based measurements of in-cylinder flow and fuel concentrations in two stroke and direct injected four-stroke engines are presented. The major problem with the carburetted two-stroke engine is the short-circuiting of fuel that occurs during the scavenging phase. This leads to large emissions of unburned hydrocarbons. LÄS MER

3. 12. Fragmentation and waste rock compaction in small-scale confined blasting

   Författare :Daniel Johansson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

   Sammanfattning : Sub-level caving (SLC) is an important mass mining method, used at LKAB e.g. The caved rock or debris at the SLC interface reduces the fragmentation and the swelling of the blasted ring and it dissipates the explosive energy. These phenomena may immobilize the blasted ring, causing ore losses. LÄS MER

4. 13. Effects of confinement and initiation delay on fragmentation and waste rock compaction : Results from small scale tests

   Författare :Daniel Johansson; Gideon Chitombo; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

   Sammanfattning : Sub-level caving (SLC) is classified as a mass mining method and there is an increasing interest in its application worldwide and in a very wide range of geotechnical environments. Design of sub-level blasting rounds and optimization has become more important now when the sizes of the blasting rings have become larger. LÄS MER

5. 14. Study and Development of Techniques to Improve Engine Stability and Reduce Emissions from Natural Gas Engines

   Författare :Patrik Einewall; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Motorer; Motors and propulsion systems; Low Emissions ; Natural Gas Engines ; EGR ;

   Sammanfattning : The objective of this thesis was to find ways to improve combustion and reduce emissions from supercharged natural gas engines. In-cylinder flow measurements were made with laser doppler velocimetry, LDV, heat release was calculated from cylinder pressures and emissions were measured at various locations. LÄS MER

7. 15. Studies on boundary values of eigenfunctions on spaces of constant negative curvature

   Författare :Pierre Bäcklund; Andreas Juhl; Andreas Strömbergsson; Genkai Zhang; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hyperbolic space; anti de Sitter space; spectral geometry; scattering theory; analysis on real and complex Lie groups; intertwining operators; Verma modules; analysis on homogeneous spaces; conformal differential geometry; Selberg zeta functions; Algebra; geometry and mathematical analysis; Algebra; geometri och analys;

   Sammanfattning : This thesis consists of two papers on the spectral geometry of locally symmetric spaces of Riemannian and Lorentzian signature. Both works are concerned with the idea of relating analysis on such spaces to structures on their boundaries.The first paper is motivated by a conjecture of Patterson on the Selberg zeta function of Kleinian groups. LÄS MER