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Showing result 1 - 5 of 62 swedish dissertations matching the above criteria.

2. 1. Split Trees, Cuttings and Explosions

   Author : Cecilia Holmgren; Svante Janson; Luc Devroye; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Random Graphs; Random Trees; Split Trees; Renewal Theory; Binary Search Trees; Cuttings; Records; Tree Algorithms; Markov Chains; Galton-Watson Processes; MATHEMATICS; MATEMATIK; Mathematics; Matematik;

   Abstract : This thesis is based on four papers investigating properties of split trees and also introducing new methods for studying such trees. Split trees comprise a large class of random trees of logarithmic height and include e.g., binary search trees, m-ary search trees, quadtrees, median of (2k+1)-trees, simplex trees, tries and digital search trees. READ MORE

4. 2. Explosions in urban environments: Modelling of gas explosions and risk of premature shear failure in reinforced concrete structures

   Author : Fabio José Lozano Mendoza; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; blast strength; urban road environments; computational fluid dynamics; blast loading; Vapour cloud explosions; factorial design; premature shear failure; Monte Carlo method; model uncertainty;

   Abstract : The risk for accidental gas explosions in urban environments has increased in Sweden in recent years. This is due to densification of existing urban centres and the rise of vehicles powered by alternative fuels. READ MORE

5. 3. Experimental Study on Steam Explosions in Chemical Solutions and Seawater

   Author : Yucheng Deng; Weimin Ma; Sevostian Bechta; Andrei Komlev; Renaud Meignen; KTH; []
   Keywords : Severe accident; fuel coolant interactions; steam explosion; chemical additives; seawater; Svåra haverier; bränsle-kylmedelsinteraktioner; ångexplosion; kemiska tillsatser; havsvatten; Kärnenergiteknik; Nuclear Engineering;

   Abstract : Steam explosions may be encountered in severe accidents of light water reactors (LWRs), which are thermal detonations caused by rapid and intense vaporization of the coolant upon its direct contact with the core melt (corium). Motivated by the interest in understanding and mitigation of severe accident progression, many studies have been conducted to investigate the steam explosion phenomena during severe accidents. READ MORE

6. 4. An Experimental Study on the Dynamics of a Single Droplet Vapor Explosion

   Author : Roberta Concilio Hansson; Weimin Ma; Geroges Berthoud; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; steam explosions; radiography; melt preconditioning; noncondensable gas; Low energy physics; Lågenergifysik;

   Abstract : The present study aims to develop a mechanistic understanding of the thermal-hydraulic processes in a vapor explosion, which may occur in nuclear power plants during a hypothetical severe accident involving interactions of high-temperature corium melt and volatile coolant. Over the past several decades, a large body of literature has been accumulated on vapor explosion phenomenology and methods for assessment of the related risk. READ MORE

7. 5. Surface Coatings as Xenon Diffusion Barriers for Improved Detection of Clandestine Nuclear Explosions

   Author : Lisa Bläckberg; Mattias Klintenberg; Henrik Sjöstrand; Anders Ringbom; Kai Vetter; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Radioxenon; Gas Diffusion Barrier; Plastic Scintillator; Comprehensive Nuclear-Test-Ban Treaty; Atomic Layer Deposition; Al2O3; Molecular Dynamics; Light Transport;

   Abstract : This thesis investigates surface coatings as xenon diffusion barriers on plastic scintillators. The motivation for the work is improved radioxenon detection systems, used within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT).One type of radioxenon detection systems used in this context is the Swedish SAUNA system. READ MORE