Sökning: "focused waves"
Visar resultat 1 - 5 av 57 avhandlingar innehållade orden focused waves.
Sammanfattning : The amount of energy enclosed in ocean waves has been classified as one of the most promising renewable energy sources. Nowadays, different wave energy conversion (WEC) systems are being investigated, but only a few concepts have been operated in a sea environment. LÄS MER
Sammanfattning : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). LÄS MER
Sammanfattning : Quality control and quality assurance of pavements is today primarily based on core samples. Air void content and pavement thickness are parameters that are evaluated. However, no parameter connected to the stiffness is evaluated. LÄS MER
Sammanfattning : Converging cylindrical shock waves have been studied experimentally. Numericalcalculations based on the Euler equations and analytical comparisons basedon the approximate theory of geometrical shock dynamics have been made tocomplement the study.Shock waves with circular or polygonal shock front shapes have been createdand focused in a shock tube. LÄS MER
Sammanfattning : This thesis is focused on the role of Alfvén waves in the energy transformation and transport in the magnetosphere. Different aspects of Alfvén wave generation, propagation and dissipation are considered. The study involves analysis of experimental data from the Freja, Polar and Cluster spacecraft, as well as theoretical development. LÄS MER