Sökning: "Johan Jönsson"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Johan Jönsson.

  1. 1. Slag/Metal Metallurgy in Iron and Steel Melts

    Författare :Johan Ekengård; Pär Jönsson; Attila Dioszegi; Johan Björkvall; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; austenit; syreaktivitet; slagg; fördelning; primär dendrit; metalldroppar; lamellär grafit; svavel; kompaktgrafit; skänk; nodulär grafit; raffinering; Metallurgical process science; Metallurgisk processvetenskap;

    Sammanfattning : In this work, the metal and slag phase mixing in three steps of a ladle refining operation of steel melts and for an oxygen balance during cooling of cast iron melts have been studied at two Swedish steel plants and at two Swedish cast iron foundries, respectively. In order to predict the oxygen activity in the steel bulk in equilibrium with the top slag as well as in metal droplets in the top slag in equilibrium with the top slag, three slag models were used. LÄS MER

  2. 2. New concepts and techniques for quantification and trace analysis by gas chromatography

    Författare :Johan Pettersson; Johan Roerrade; Jan Åke Jönsson; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Chemistry; quantitative accuracy; calibration; extenal standards; valume contraction; molar excess volume; Kemi; Chemistry; Kemi;

    Sammanfattning : In the first part of this thesis, strategies for avoiding systematic errors when quantifying the main components in mixtures of solvents has been developed (paper I). It is shown that variations in density caused by variations in sample composition and/or volume contraction need to be taken into account. In this way, quantification can be improved. LÄS MER

  3. 3. A Probabilistic Approach to Non-Markovian Impulse Control

    Författare :Johan Jönsson; Magnus Perninge; Säid Hamadène; Linnéuniversitetet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Stochastic optimal control; optimal stopping; optimal switching; impulse control; Snell envelope; obstacle problems; partial differential equation; Matematik; Mathematics;

    Sammanfattning : This thesis treats mathematical considerations that arise in relation to certain stochastic optimal control problems, in particular of switching and impulse type. Both of these problems are extensions of the well-known optimal stopping problem. LÄS MER

  4. 4. High precision Ac susceptibility : a probe to exchange bias, and flux creep in high-Tcmaterials

    Författare :Johan Jönsson; KTH; []
    Nyckelord :;

    Sammanfattning : .... LÄS MER

  5. 5. Moisture Induced Stresses in Timber Structures

    Författare :Johan Jönsson; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknik; load carrying capacity; Technological sciences; reinforcement; short-term strength perpendicular to grain; internal stresses; glulam; contact free measuring technique moisture gradients;

    Sammanfattning : Wood is a hygroscopic material; always striving to reach equilibrium with the surrounding air, and consequently the moisture content is different in different climate conditions. The strength of wood is directly dependent on the moisture content, lower moisture content leads to increasing strength. LÄS MER