Search for dissertations about: "electromagnetic thesis pdf"

Showing result 21 - 25 of 479 swedish dissertations containing the words electromagnetic thesis pdf.

2. 21. Modelling of Terahertz Planar Schottky Diodes

   Author : Aik-Yean Tang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; S-parameter extraction; Electro-thermal; Schottky diodes; Skin effect; Electromagnetic; Frequency multipliers; High-power frequency multiplier; Current crowding; Proximity effect; Submillimetre wave generation and detection; Geometric modelling; Gallium Arsenide;

   Abstract : This thesis deals with the modelling of THz planar Schottky diodes, focusing on analyses of the geometry- dependent parasitics and the diode chip thermal management. Moving towards higher operating frequencies, the electromagnetic couplings pose significant limitations on the diode performance. READ MORE

4. 22. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes

   Author : Mohd Muzafar Ismail; Vernon Cooray; Farhad Rachidi; Uppsala universitet; []
   Keywords : negative cloud-to-ground lightning flashes; HF and VHF radiation; chaotic pulse trains; lightning initiation; zero-crossing time; electromagnetic fields; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

   Abstract : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. READ MORE

5. 23. Inversion and Joint Inversion of Electromagnetic and Potential Field Data

   Author : Jochen Kamm; Ari Tryggvason; Laust B Pedersen; Mehrdad Bastani; Douglas Oldenburg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Inversion; Electromagnetic methods; Joint inversion; Potential Field methods; Inversion; Elektromagnetische Verfahren; Joint-Inversion; Potentialverfahren; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Abstract : In this thesis, four inversion problems of different scale and difficulty are solved. Two of them are electromagnetic inverse problems. Two more are joint inversion problems of potential field data and other types of data. READ MORE

6. 24. On the Design of Ultra-fast Electro-Mechanical Actuators

   Author : Ara Bissal; Göran Engdahl; Torbjörn Lembke; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electro-mechanical drive; Circuit breakers; HVDC transmission; Eddy currents; Finite element; Electromagnetic; Thermal; Mechanical; Coils; Armature; Image motion analysis.;

   Abstract : The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. READ MORE

7. 25. The PANDA electromagnetic calorimeter at photon energies below 100 MeV

   Author : Dirk Wölbing; Per-Erik Tegnér; Thomas Nilsson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; PANDA; vacuum photo tetrodes; electromagnetic calorimeter; fysik; Physics;

   Abstract : The PANDA  experiment (antiproton annihilation at Darmstadt) is designed for studies of the strong force in the transition region between perturbative and non-perturbative quantum chromo dynamics (QCD). It will be built and placed at the high-energy storage ring, HESR, at FAIR (Facility for antiproton and ion research) in Darmstadt and start its first experiments in 2025. READ MORE