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Showing result 1 - 5 of 173 swedish dissertations matching the above criteria.

  2. 1. Analysis of Conformal Antennas and Periodic Structures

    Author : Silvia Raffaelli; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; method of moments; microstrip; corrugated surface; horn; Floquet; array; periodic; multilayer structure; finite difference time domain; dual-frequency; infinite; spectral domain analysis; conformal antenna;

    Abstract : In the last decades much attention has been paid to the design of high-performance antennas. Accurate control of the radiation properties is very important in electromagnetic engineering applications. READ MORE

  4. 2. Analysis of Planar and Circular Cylindrical Multilayer Structures with Application to Soft and Hard Surfaces

    Author : Zvonimir Sipus; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antennas; periodic surfaces; integral equations; approximate boundary conditions; soft and hard surfaces; Green s functions; corrugated surfaces; moment method; periodic metal strips; multilayer structures; EFIE; microstrip antennas; spectral domain analysis; group representation theory; strip scatterers;

    Abstract : This thesis deals with the analysis of planar and circular cylindrical multilayer structures, such as strip-loaded dielectric layers, corrugated surfaces and microstrip antennas. In particular, we study corrugations and strip-loaded grounded dielectric slabs when they are used to realize soft and hard surfaces. READ MORE

  5. 3. On the use of periodic operation for improvning chemical processes

    Author : Lennart Vamling; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic operation; di-; ammonia; and triethanolamine production; ethylene oxide; zeolites; Mono-; yield; adiabatic packed-bed reactor; selectivity;

    Abstract : In this thesis, some methods of improving the product distribution from chemical processes are compared. The first two parts contain an experimental investigation of how the product distribution of a process is influenced by the choice of catalyst. READ MORE

  6. 4. CFD Simulations for Film Cooling : Reduced Models at Engine Like Conditions

    Author : Andreas Bradley; Matts Karlsson; Karl Storck; Linköpings universitet; []
    Keywords : ;

    Abstract : In gas turbines some parts are exposed to combustion gases with temperatures well above the melting temperature of the material. Therefore, various cooling techniques are utilized in order to protect the parts exposed to these hot gases. One such technique, film cooling, is a common and well established way to protect the exposed parts. READ MORE

  7. 5. On the Structure and Dynamics of Polyelectrolyte Gel Systems and Gel-surfactant Complexes

    Author : Per Johan Råsmark; Christer Elvingson; Johan Bergenholtz; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; polyelectrolyte gel; microgel; dynamic light scattering; Raman spectroscopy; periodic boundary conditions; percolation; hypersphere; Monte Carlo; Brownian dynamics; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Abstract : This thesis describes the results of experimental work on polyelectrolyte gels and their interaction with oppositely charged surfactants, and presents two new algorithms applicable to the simulation of colloid and polymer systems.The model systems investigated were crosslinked poly(acrylate) (PA) and poly(styrene sulphonate) (PSS), and the surfactant was dodecyl trimethylammonium bromide (DoTAB). READ MORE