Search for dissertations about: "Sven Norgren"

Showing result 1 - 5 of 6 swedish dissertations containing the words Sven Norgren.

2. 1. Effects of Reject Refining at High Temperature on TMP Fibre Properties

   Author : Sven Norgren; Hans Höglund; Lars Johansson; Mittuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre collapse; fibre decollapse; high temperature; refining; reject; roughening; bonding; acoustic emission; mechanical pulping; softening temperature; bond strength; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Abstract : .... READ MORE

4. 2. Online power transformer diagnostics using multiple modes of microwave radiation

   Author : Mariana Dalarsson; Martin Norgren; Sven Nordebo; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problem; multiple modes; power transformers;

   Abstract : In the present thesis, we propose and investigate a new approach to diagnose the effects of the various degradation mechanisms, including thermal degradation at hot spots, winding deformations due to the mechanical forces from short circuit currents, partial discharges due to local electric field surges, and increased moisture levels in the cellulose insulation due to decomposition, that affect electric power transformers during their normal operation in an electric power grid.Although the proposed diagnostics method can in principle be used to detect various degradation mechanisms mentioned above, we focus in the present thesis on mechanical deformations of transformer winding structures. READ MORE

5. 3. Electromagnetic dispersion modeling and analysis for HVDC power cables

   Author : Stefan Gustafsson; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; HVDC power cables; electromagnetic model; TDR measurement; sensitivity analysis; dispersion relation; propagation constant; low-frequency asymptotics;

   Abstract : Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications. READ MORE

6. 4. Estimation of electromagnetic material properties with application to high-voltage power cables

   Author : Yevhen Ivanenko; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material losses; power cables; cylindrical multipole expansion; Herglotz functions; convex optimization; sum rules; Waves and Signals; Vågor och signaler;

   Abstract : Efficient design of high-voltage power cables is important to achieve an economical delivery of electric power from wind farms and power plants over the very long distances as well as the overseas electric power. The main focus of this thesis is the investigation of electromagnetic losses in components of high-voltage power cables. READ MORE

7. 5. Mechanical Pulp Based Nano-ligno-cellulose : Production, Characterisation and their Effect on Paper Properties

   Author : Sinke Henshaw Osong; Per Engstrand; Sven Norgren; Kristin Syverud; Mittuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mechanical pulp; thermo-mechanical pulp; chemi-thermomechanical pulp; fractionation; fines; homogenisation; nanocellulose; nano-ligno-cellulose NLC ; handsheets; strength properties; crill;

   Abstract : Almost all research on biorefinery concepts are based on chemical pulping processes and ways of utilising lignin, hemicelluloses and extractives as well as a part of the remaining cellulose for production of nano materials in order to create more valuable products than today. Within the Forest as a Resource (FORE) research program at FSCN we are utilising the whole chain of unit processes from forestry to final products as paper and board, where the pulping process research focus on high yield process as TMP and CTMP. READ MORE