Sökning: "vessel element"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden vessel element.

  1. 1. Thermo-mechanical Assessment of Reactor Pressure Vessels of Light Water Reactors During Severe Accidents

    Författare :Hongdi Wang; Walter Villanueva; Sevostian Bechta; Weimin Ma; Artem Kulachenko; Michael Fitzpatrick; KTH; []
    Nyckelord :Severe accident scenario; reactor pressure vessel; in-vessel melt retention; failure analysis; finite element analysis; validations; Scenario för svåra haverier; reaktortank; in-vessel retention; feleffektsanalys; Finite Element Analyser; validering; Physics; Fysik;

    Sammanfattning : The reactor pressure vessel (RPV) is one of the crucial safety barriers designed to isolate the reactor core, safeguarding against potential radioactive releases into the environment during a severe accident. The assessment of RPV behaviour and its failure is necessary to predict the characteristics of melt release into the reactor pit and succeeding ex-vessel accident progression. LÄS MER

  3. 2. The significance of ethylene and ethylene response factors in wood formation of hybrid aspen

    Författare :Bernard Wessels; Hannele Tuominen; Judith Felten; Totte Niittylä; Kurt Fagerstedt; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ethylene; wood formation; hybrid aspen; Populus; ETHYLENE RESPONSE FACTOR; ERF85; ERF139; cambium; lignin; xylem expansion; secondary cell wall; tension wood; cambial derivative cell fate; vessel element; time-lapse photography; molekylär bioteknik inst f nat vet biokemi ; molecular biotechnology dept of biochem ; Genetics; genetik; Physiological Botany; fysiologisk botanik;

    Sammanfattning : The woody tissues serve to stabilise plants, store nutrients and translocate water and minerals. The formation of wood, or ’secondary xylem’, follows a well-defined developmental gradient which is initiated by cell division activity in the vascular cambium. LÄS MER

  4. 3. Xylem cells cooperate in the control of lignification and cell death during plant vascular development

    Författare :Sacha Escamez; Hannele Tuominen; Andrew Groover; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Xylem; Arabidopsis; programmed cell death; tracheary element; xylem vessel; autophagy; metacaspase; lignin; secondary cell wall; chromatin; gene expression;

    Sammanfattning : The evolutionary success of land plants was fostered by the acquisition of the xylem vascular tissue which conducts water and minerals upwards from the roots. The xylem tissue of flowering plants is composed of three main types of cells: the sap-conducting tracheary elements (TE), the fibres which provide mechanical support and the parenchyma cells which provide metabolic support to the tissue. LÄS MER

  5. 4. Finite element modelling of hydroelasticity in hull-water impacts

    Författare :Ivan Stenius; Dan Zenkert; Pennny Temarel; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid-structure interaction; hydroelasticity; hull-water impact; high-speed craft; slamming; explicit finite element methods; Vehicle engineering; Farkostteknik;

    Sammanfattning : The work in this thesis focuses on the use of explicit finite element analysis (FEA) in the modelling of fluid-structure interaction of panel-water impacts. Paper A, considers modelling of a two-dimensional rigid wedge impacting a calm water surface. LÄS MER

  7. 5. Inverse and optimization problems in electromagnetics -- a finite-element method perspective

    Författare :JOHAN WINGES; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave measurements; computational electromagnetics; finite element method; optimization; inductive power transfer; compressed sensing; wireless power; brick-tetrahedron hybrid; parameter estimation; inverse problems;

    Sammanfattning : In this thesis, a selection of inverse and optimization problems are studied where the finite element method (FEM) serves as a comprehensive tool to solve electromagnetic field problems that lack an analytic solution. The inverse problems are typically formulated in terms of an optimization problem where the misfit between a measurement and the corresponding result of a computational model is minimized. LÄS MER