Sökning: "differential thermal analysis"

Visar resultat 1 - 5 av 60 avhandlingar innehållade orden differential thermal analysis.

  1. 1. Characterization and Compensation of Thermal Effects in GaN HEMT Technologies

    Författare :Johan Bremer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal coupling; thermal effects; thermal resistance; AlGaN GaN; temperature compensation.; electrothermal; characterization;

    Sammanfattning : Further advancements with GaN based technologies relies on the ability to handle the heat flux, which consequently arises from the high power density. Advanced cooling techniques and thermal optimization of the technology are therefore prioritized research areas. LÄS MER

  3. 2. Structure of Hardened Cement-Fly Ash Systems and Their Related Properties

    Författare :Aimin Xu; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; water vapour sorption isotherms; thermogravity analysis; mortar; scanning electron microscopy; differential thermal analysis; X-ray diffraction analysis; fly ash; pore structure; microstructure; cement paste;

    Sammanfattning : The influence of fly ash on the pore structure and microstructure of cement paste and mortar has been investigated. The methods applied include water vapour sorption isotherms, scanning electron microscopy, X-ray diffraction analysis and thermogravity/differential thermal analysis. LÄS MER

  4. 3. Efficiency factors for space heating system in buildings

    Författare :Christian Brembilla; Thomas Olofsson; Ronny Östin; Mohsen Soleimani-Mohseni; Bjørn Reidar Sørensen; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Efficiency factors of space heating; hydronic panel radiator; hydronic floor heating; multilayer wall; numerical modelling; room control volume; decrement factor; time delay; heat conduction; heat convection; heat radiation; heat storage; thermal inertia; Euler solver; Newton-Raphson method; synthetic weather file; feedback and feed-forward control strategies; adaptive control; validation methodology; uncertainty bands; robustness of model predictions; thermostatic booth simulator; differential sensitivity analysis; transient model of panel radiator with multiple storage elements; active thermal mass; benchmark performance indicator; linear regression model; calibration through uncertainty bands; hybrid model of low-energy building: law driven data driven; outdoor temperature compensation heating curve; solar radiation model; finite difference method; heat equation;

    Sammanfattning : The thesis focuses on the efficiency of the space heating system. In particular, the efficiency factors measure the efficiency of thermal zone. The efficiency factors measures how the energy is used in a space heating. LÄS MER

  5. 4. Investigations of the Kinetics of Reduction and Reduction/Carburization of NiO-WO3 Precursors

    Författare :Hesham M. Ahmed; Seshadri Seetharaman; Ricardo Morales Estrella; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduction; Reduction-Carburization; Gas-solid Reactions; Kinetics; Hydrogen; Methane; Thermogravimetric analysis; Fluidized bed; Simulation; Thermal diffusivity; Thermal conductivity; Laser flash; Metallurgical process engineering; Metallurgisk processteknik; Process Metallurgy;

    Sammanfattning : Kinetic studies of reduction of the mixtures of NiO and WO3 having different Ni/(Ni+W) molar ratios in flowing hydrogen gas were investigated by means of Thermo Gravimetric Analysis (TGA), Fluidized Bed (FB) technique as well as Thermal diffusivity measurements under isothermal conditions. In the case of TGA, the reaction progress was monitored by mass loss, while evolved gas analysis by a gas chromatograph was the indicator of the reaction progress in the case of FB. LÄS MER

  7. 5. Differential migration in raptors

    Författare :Nils Kjellén; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Osprey; Skua; Population monitoring; Bird migration; Satellite telemetry; Animal ecology; Djurekologi;

    Sammanfattning : Differences between ages, sexes and populations in the timing of migration at Falsterbo, Sweden and in the choice of wintering site among raptors in Scania were investigated. Competition and dominance is the best primary explanation to the results. LÄS MER