Search for dissertations about: "Shell structures"

Showing result 11 - 15 of 146 swedish dissertations containing the words Shell structures.

2. 11. Synthesis and Characterization of Carbon Based One-Dimensional Structures : Tuning Physical and Chemical Properties

   Author : HamidReza Barzegar; Thomas Wågberg; Hans Kuzmany; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Carbon Nanotube; single-walled carbon nanotube; nitrogen doped; chemical vapor deposition; fullerene; hybrid structures; nanomaterials; nanomaterial;

   Abstract : Carbon nanostructures have been extensively used in different applications; ranging from electronic and optoelectronic devices to energy conversion. The interest stems from the fact that covalently bonded carbon atoms can form a wide variety of structures with zero-, one- and two-dimensional configuration with different physical properties. READ MORE

4. 12. Deployment Control of Spinning Space Webs and Membranes

   Author : Mattias Gärdsback; Anders Eriksson; Gunnar Tibert; Thomas W. Murphey; KTH; []
   Keywords : Flexible structures; space webs; membranes; solar sails; solar power systems; deployment control; optimal control; centrifugal force deployment; spin deployment; rotation-free; shell elements; TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : Future solar sail and solar power satellite missions require deployment of large and lightweight flexible structures in space. One option is to spin the assembly and use the centrifugal force for deployment, stiffening and stabilization. READ MORE

5. 13. Between square and circle : A study on the behaviour of polygonal steel profiles under compression

   Author : Panagiotis Manoleas; Ove Lagerqvist; Efthymios Koltsakis; Leroy Gardner; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polygonal; RCPS; plate buckling; shell buckling; towers; transmission lines; wind turbines; high strength steel; Stålbyggnad; Steel Structures;

   Abstract : The present study explores the structural properties of regular convex polygonal cross section (RCPS). Such profiles are commonly used to construct masts and towers, e.g.  transmission towers, light poles etc. READ MORE

6. 14. Frustrated magnetism in icosahedral structures : The influence of order-disorder in quasicrystals and approximant crystals

   Author : Fernand Denoel; Roland Mathieu; Marc de Boissieu; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasicrystals; approximant crystals; spin glasses; SQUID magnetometry; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Abstract : This work will begin with an introduction to quasicrystals (QCs) and their structure, defining the unit cell-equivalent for icosahedral quasiperiodicity: a 3D tiling based on the golden ratio and aperiodic in all three dimensions. We briefly present the cut-and-project method used to generate QCs from a higher dimension hypercrystal, and how to build the 3D Penrose tilings, composed of the two golden rhombohedra. READ MORE

7. 15. Prestress and its application to shell, fabric, and cable net structures

   Author : Alexander Sehlström; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HUMANIORA; HUMANITIES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Geometric stiffness; Form finding; Conceptual design; Stress pattern; Engineering; Prestress; Architecture; Structuraldesign;

   Abstract : Prestressing and shells provide means to create material-efficient and well-functioning structures, as do their combination, offering opportunities for increased material efficiency within the built environment. Prestressing introduces stresses in an object to enhance its performance, and shells include concrete shells, masonry vaults, fabric structures, cable nets, and timber or steel gridshells. READ MORE