Sökning: "losses"

Visar resultat 11 - 15 av 1393 avhandlingar innehållade ordet losses.

  1. 11. Characterization of (Ba,Sr)TiO3 thin films for multiplier applications

    Författare :Pär Rundqvist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; BSTO; THz; triplers; powerhandling capability; multilayer structures; frequency multipliers; Ferroelectric; BST; losses; Varactor; STO;

    Sammanfattning : (Ba,Sr)TiO3 (BSTO) and SrTiO3 (STO) parallel plate ferroelectric varactors are investigated for microwave multiplier applications.STO and BSTO exhibit low losses, high permittivity and largetunability of both permittivity and losses. All films are deposited using Pulsed Laser Deposition, magnetron sputtering and E-beam evaporation. LÄS MER

  3. 12. Experimental Investigation of Performance, Flow Interactions and Rotor Forcing in Axial Partial Admission Turbines

    Författare :Jens Fridh; Torsten Fransson; Björn Laumert; Jürgen Seume; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; axial turbine; partial admission; part loads; experimental investigation; turbine performance; losses; dynamic rotor forces; forced response; unsteady flow; axialturbin; partialpådrag; dellaster; reglersteg; experimentell undersökning; turbinprestanda; förluster; dynamiska krafter; rotorvibration; instationär strömning;

    Sammanfattning : The thesis comprises a collection of four papers with preceding summary and supplementary appendices. The core investigation solely is of experimental nature although reference and comparisons with numerical models will be addressed. LÄS MER

  4. 13. Synchronous generator and frequency converter in wind turbine applications : system design and efficiency

    Författare :Anders Grauers; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronous generator; frequency converter; wind turbine; avrage efficiency; losses; system design; variable speed;

    Sammanfattning : This report deals with an electrical system for variable-speed wind powerplants. It consists of a synchronous generator, a diode rectifier and athyristor inverter. LÄS MER

  5. 14. Aerodynamic Investigations of a High Pressure Turbine Vane with Leading Edge Contouring at Endwall in a Transonic Annular Sector Cascade

    Författare :Ranjan Saha; Torsten Fransson; Markus Jöcker; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high pressure turbine; secondary flow; leading edge contouring; endwall; experimental investigations; losses; flow field; hub cooling flow; högtrycksturbinen sekundärströmning; framkantsmodifiering; ändvägg; experimentell undersökning; förluster; strömningsfält; filmkylning av inre platform;

    Sammanfattning : Efficiency improvement is an important aspect to reduce the use of fossil-based fuel in order to achieve a sustainable future. Gas turbines are mainly fossil-fuel based turbomachines, and, therefore, efficiency improvement is still the subject of many on-going research activities in the gas turbine community. LÄS MER

  7. 15. Design and Characterization of RF-LDMOS Transistors and Si-on-SiC Hybrid Substrates

    Författare :Sara Lotfi; Jörgen Olsson; Örjan Vallin; Jean-Pierre Raskin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LDMOS; RF; losses; crosstalk; silicon carbide; Si-on-SiC hybrid substrate; wafer bonding; CMOS; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

    Sammanfattning : With increasing amount of user data and applications in wireless communication technology, demands are growing on performance and fabrication costs. One way to decrease cost is to integrate the building blocks in an RF system where digital blocks and high power amplifiers then are combined on one chip. LÄS MER