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Showing result 1 - 5 of 54 swedish dissertations matching the above criteria.

2. 1. Propagation of some coherent and partially coherent laser beams

   Author : Yangjian Cai; Sailing He; Franco Gori; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : dark hollow beam; elliptical Gaussian beam; flat-topped beam; twisted anisotropic Gaussian Schell-model; partial coherent; propagation; paraxial optical system; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : In this thesis, we investigate the propagation of some coherent and partially coherent laser beams, including a dark hollow beam (DHB), an elliptical Gaussian beam (EGB), a flat-topped beam and a twisted anisotropic Gaussian Schell-model (TAGSM) beam, through a paraxial optical system or a turbulent atmosphere. Several theoretical models are proposed to describe a DHB of circular or non-circular symmetry. READ MORE

4. 2. Antennas, Wave Propagation, and Localization in Wireless Body Area Networks

   Author : Rohit Chandra; Institutionen för elektro- och informationsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless Body Area Network; WBAN; body sensor network; body-centric communication; wearable devices; ear-to-ear propagation; antennas; analytical propagation model; localization; wireless capsule endoscopy; in-mouth device; implants;

   Abstract : A network of communicating wireless devices that are implantable, wearable or within close proximity of a human body is called wireless body area network (WBAN). The propagation channels for the devices in the WBAN are either through the body or over the body. READ MORE

5. 3. Some numerical and analytical methods for equations of wave propagation and kinetic theory

   Author : Eva Mossberg; Alexander Bobylev; Giovanni Russo; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; wave propagation; finite difference metods high order methods; Landau-Fokker-Planck equation; Monte-Carlo simulations; Boltzmann equation; hard sphere model; eigenvalue problem; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

   Abstract : This thesis consists of two different parts, related to two different fields in mathematical physics: wave propagation and kinetic theory of gases. Various mathematical and computational problems for equations from these areas are treated. READ MORE

6. 4. Benefits of strengthening timber with fibre-reinforced polymers

   Author : Alann André; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimental results; Carbon; Timber; Tension perpendicular to the grain; Ductility; Flax; Reinforcement; Compression failure parallel to the grain; Kinkband; Composite materials; Numerical model; Analytical model; FRP;

   Abstract : As a material, timber offers a wide range of alternatives in terms of structural applications. The natural defects present in timber are, however, the source of large variations in mechanical properties. READ MORE

7. 5. Device Technology Based on High Temperature Superconductors and Microwave Breakdown in Gases

   Author : Martin Löfgren; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distortion; penetration depth; surface resistance; transmit-receive switch; coupled-grain model; high-power; microwave; pulse; surface impedance; breakdown; propagation; modulator; air; superconductor; transmission line; resonator; coplanar waveguide; plasma;

   Abstract : This thesis deals with two separate fields of microwave technology. The first section treats microwave characterization and applications of high temperature superconducting (HTS) thin films, while the second section treats microwave breakdown in transmit-receive (TR) switches and in air. Within the first section, four main topics are adressed. READ MORE