Sökning: "critical temperature"

Visar resultat 1 - 5 av 464 avhandlingar innehållade orden critical temperature.

  1. 1. Temperature and heat losses simulation in core and winding of a power transformer

    Författare :Kourosh Mousavi Takami; Mahmoudi Jafar; Lennart Harnefors; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Transformer; Losses; Simulation; Temperature; Calculation; TECHNOLOGY Electrical engineering; electronics and photonics Electric power engineering; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Elkraftteknik; elektronik; Electronics;

    Sammanfattning : Simulering av temperatur och värmeförluster i kärna och lindning för en högspänningstransformator“... Ett ljus som lyser dubbelt så starkt, varar hälften så länge …”, i analogi med ljuset så kan transformatorer köras med överlast inom vissa gränser, men med följden att livslängden blir kortare. LÄS MER

  2. 2. Structural and Electrical Transport Properties of Doped Nd-123 Superconductors

    Detta är en avhandling från Stockholm : Fysik

    Författare :Shaban Reza Ghorbani; [2003]
    Nyckelord :high temperature superconductors; critical temperature; resistivity; thermoelectric power; Hall coefficient; X-ray diffraction; Neutron diffraction; NdBa2Cu3O7-delta; hole concentration; substitution;

    Sammanfattning : It is generally believed that one of the key parameterscontrolling the normal state and superconducting properties ofhigh temperature superconductors is the charge carrierconcentrationpin the CuO2planes.By changing the non-isovalent dopingconcentration on the RE site as well as the oxygen content in(RE)Ba2Cu3O7−δ, an excellent tool is obtained tovary the hole concentration over a wide range from theunderdoped up to the overdoped regime. LÄS MER

  3. 3. Resistivity and the solid-to-liquid transition in high-temperature superconductors

    Detta är en avhandling från Stockholm : KTH

    Författare :Beatriz Espinosa Arronte; Magnus Andersson; Charles Simon; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductors; vortex dynamics; vortex solid-to-liquid transition; critical scaling; glass transition; Bose glass; heavy-ion irradiation; YBCO; Tl2Ba2CaCu2O8 d; oxygen deficiency.; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik Kondenserade materiens fysik;

    Sammanfattning : In high-temperature superconductors a large region of the magnetic phase diagram is occupied by a vortex phase that displays a number of exciting phenomena. At low temperatures, vortices form a truly superconducting solid phase which at high temperatures turns into a dissipative vortex liquid. LÄS MER

  4. 4. Development of loss models for a high-temperature superconducting tape

    Detta är en avhandling från Stockholm : Elektrotekniska system

    Författare :Niclas Schönborg; [2001]
    Nyckelord :high-temperature superconductor; hysteresis losses; flux flow losses; critical state model; calorimetric measurements;

    Sammanfattning : In the recent years significant progresses in thedevelopment of high-temperature superconductors have been made.It is realistic to believe that power applications, based onthese conductors, in a few years will become available. LÄS MER

  5. 5. Phase transitions in high-temperature superconductors

    Detta är en avhandling från Stockholm : KTH

    Författare :Jack Lidmar; [1998]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Superconductivity; Vortices; Phase transitions; Strongly correlated fermions; High-temperature superconductivity; Monte Carlo simulations.; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : Thermal fluctuations and disorder strongly influence the behaviour of hightemperature superconductors. In particular the vortices play a key role in determining their properties. In this thesis the main focus lies on phase transitions, both in ultra-thin films and in three-dimensional systems, which are driven by vortex fluctuations. LÄS MER