Sökning: "metallic contacts"

Visar resultat 11 - 15 av 19 avhandlingar innehållade orden metallic contacts.

  1. 11. On the Design of Ultra-fast Electro-Mechanical Actuators

    Författare :Ara Bissal; Göran Engdahl; Torbjörn Lembke; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electro-mechanical drive; Circuit breakers; HVDC transmission; Eddy currents; Finite element; Electromagnetic; Thermal; Mechanical; Coils; Armature; Image motion analysis.;

    Sammanfattning : The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. LÄS MER

  3. 12. Thin metal films on weakly-interacting substrates : Nanoscale growth dynamics, stress generation, and morphology manipulation

    Författare :Andreas Jamnig; Kostas Sarakinos; Gregory Abadias; Gregory Thompson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Thin films; magnetron sputter-deposition; in situ and real-time characterization; early film growth stages; residual stress; manipulation of morphology; Couches minces; pulvérisation magnétron; caractérisation in situ en temps réel; premiers stades de croissance; contraintes résiduelles; manipulation de morphologie;

    Sammanfattning : Vapor-based growth of thin metal films with controlled morphology on weakly-interacting substrates (WIS), including oxides and van der Waals materials, is essential for the fabrication of multifunctional metal contacts in a wide array of optoelectronic devices. Achieving this entails a great challenge, since weak film/substrate interactions yield a pronounced and uncontrolled 3D morphology. LÄS MER

  4. 13. Influence of intermolecular order at the interfaces

    Författare :Parisa Sehati; Michel P. de Jong; Mats Fahlman; Giovanna Iucci; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : The work presented in this thesis covers a range of different surfaces and interfaces of organic molecules/polymers and metallic materials. It is of vita importance to understand how charge transfer processes and other electrical interactions existing at physisorped contacts can influence the electronic structure at an interface. LÄS MER

  5. 14. Studies on Current Commutation in Hybrid DC-breakers

    Författare :Jesper Magnusson; Göran Engdahl; Magne Runde; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commutation; Hybrid DC-breakers; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Compared to conventional AC-circuit breakers, a DC-breaker has to act fast and force the current down to zero. Many different DC-breaker topologies are available, and this thesis is focused on the hybrid DC-breaker comprising a mechanical switch and high power semiconductors. LÄS MER

  7. 15. Carbide and MAX-Phase Engineering by Thin Film Synthesis

    Författare :Jens-Petter Palmquist; Ulf Jansson; M. Jochen Schneider; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; Thin films; microstructure; epitaxy; carbide; WC; MAX-phase; Ti3SiC2; DC magnetron sputtering; PVD; Reciprocal Space Mapping; RSM; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

    Sammanfattning : This thesis reports on the development of low-temperature processes for transition metal carbide and MAX-phase thin film growth. Magnetron sputtering and evaporation, far from thermodynamical equilibrium, have been utilised to engineer the properties of the films by physical and chemical control. LÄS MER