Sökning: "Adiabatic temperature change"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Adiabatic temperature change.

  1. 1. Direct and indirect magnetocaloric properties of first- and second-order phase transition materials

    Författare :Sagar Ghorai; Peter Svedlindh; Martin Sahlberg; Gabriella Andersson; Ekkes Brück; Uppsala universitet; []
    Nyckelord :Magnetocaloric effect; Adiabatic temperature change; Direct measurement of magnetocaloric effect; Griffiths phase; Magneto-elastic transition; Magneto-structural transition; Second-order magnetic phase transition; First-order magnetic phase transition; Isothermal magnetic entropy change; Fysik; Physics;

    Sammanfattning : The energy-efficient and environmentally friendly alternative cooling technology based on the magnetocaloric effect (MCE) is discussed in this thesis. The thesis has two major parts, one devoted to material characterization and the other to instrument development. LÄS MER

  3. 2. High strain rate deformation of Alloy 718, Influence of Microstructure on Mechanical Properties

    Författare :Joakim Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Alloy 718; Adiabatic shear localisation; Split-Hopkinson; Johnson-Cook;

    Sammanfattning : Alloy 718 is a high temperature alloy, used where high temperature strength or oxidation resistance is required. As the alloy is precipitate heat treatable, it is possible to have a large variety of deformation and mechanical properties depending on microstructure. LÄS MER

  4. 3. Combustion Bowl Heat Transfer Analysis in Diesel and PPC Engines

    Författare :Helgi Fridriksson; Värmeöverföring; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Heat Transfer; CFD; Internal Combustion Engine; Diesel; PPC;

    Sammanfattning : This thesis concerns a numerical investigation on heat transfer in internal combustion engines, with the aim of increasing engine efficiency. The efficiency gains are to be extracted from reduced heat transfer losses, by increasing the knowledge on how the heat transfer process is affected by various hardware and operational parameters in the engine. LÄS MER

  5. 4. Spin Vortices, Interlayer Exchange, and Magnetocalorics in Multilayers

    Författare :Milton Persson; Vladislav Korenivski; David B. Haviland; Coriolan Tiusan; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spin vortex pairs; bimerons; RKKY; finite size effects; nanostructure magnetocalorics; atomistic spin dynamics; nanocalorimetry; Spinvirvelpar; bimeron; RKKY; finita storlekseffekter; magnetkalorimetri i nanostrukturer; atomistisk spindynamik; nanokalorimetri; Material and Nano Physics; Material- och nanofysik;

    Sammanfattning : In this thesis we study strongly coupled pairs of spin vortices, in a configurationsuch that the cores attract while external fields act to pull them apart, with potential applications in magnetic random access memory (MRAM) and oscillators.Inertial decoupling of the cores has been studied and can be achieved with weak nanosecond pulses by the help of anharmonicity. LÄS MER

  7. 5. Magnetic materials with tunable thermal, electrical, and dynamic properties : An experimental study of magnetocaloric, multiferroic, and spin-glass materials

    Författare :Matthias Hudl; Per Nordblad; DD Sarma; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetocalorics; multiferroics; spin glasses; magnetization; polarization; spin-dimensionality; Fasta tillståndets fysik; Solid State Physics;

    Sammanfattning : This thesis concerns and combines the results of experimental studies of magnetocaloric, multiferroic and spin-glass materials, using SQUID magnetometry as the main characteriza-tion technique. The magnetocaloric effect offers an interesting new technology for cooling and heating applications. LÄS MER