Sökning: "contact ratio"

Visar resultat 6 - 10 av 165 avhandlingar innehållade orden contact ratio.

1. 6. Thermally stable electrical contacts to 6H silicon carbide

   Författare :Nils Lundberg; Mikael Östling; Claude Jaussaud; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; I-V current -voltage ; C-V capacitance-voltage ; rectifying; ohmic; interface; silicide; carbide; epilayer; Schottky barrier height; current rectification ratio CRR ; specific contact resistivity; transmission line model TLM ; contact resistance; transfer length; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Silicon Carbide (SiC) are at present being developed for use in high temperature (≥ 500◦C) and high-power environments under which conventional semiconductors can hardly perform.  Thermally stable electrical contacts are essential to the ability of SiC to function under such extreme conditions. LÄS MER

3. 7. Non-contact surface wave measurements on pavements

   Författare :Henrik Bjurström; Nils Rydén; Björn Birgisson; Jinying Zhu; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; seismic testing; asphalt concrete; dynamic modulus; non-contact measurements; rolling measurements; surface waves; Lamb waves; MEMS microphones; Byggvetenskap; Civil and Architectural Engineering;

   Sammanfattning : In this thesis, nondestructive surface wave measurements are presented for characterization of dynamic modulus and layer thickness on different pavements and cement concrete slabs. Air-coupled microphones enable rapid data acquisition without physical contact with the pavement surface. LÄS MER

4. 8. Quadruped robot control and variable leg transmissions

   Författare :Johan Ingvast; Jan Wikander; Harry Dankowicz; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; walking robot; quadruped; walking; crawl; trot; passively variable transmission; PVT; variable transmission; continuously variable transmission; velocity ratio; torque ratio; Other engineering mechanics; Övrig teknisk mekanik;

   Sammanfattning : The research presented in this thesis regards walking of quadruped robots, and particularly the walking of the Warp1 robot. The motivation for the robot is to provide a platform for autonomous walking in rough terrain. The thesis contains six papers ranging from development tools to actuation of robot legs. LÄS MER

5. 9. On Contact Mechanisms and Mechanical Transmission Performance

   Författare :Lars Maclennan; Maskinelement; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; hydraulics; Mechanical engineering; artificial neural network; experimental study; disc brake; dynamic analysis; shaft; Spur gear;

   Sammanfattning : This thesis consists of four papers, which treat the modelling of a spur gear set and a disc brake, and the interaction between the machine elements. Features of the performance are studied in relation to the initial stated assumptions. LÄS MER

7. 10. Application of Automated Non-contact Resonance Testing for Low Temperature Behavior of Asphalt Concrete

   Författare :Abiy Bekele; Nils Ryden; Safwat Said; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Resonance testing; stiffness modulus; asphalt concrete; Non-contact excitation; Resonance frequency; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning : Impact resonance testing is a well-documented non-destructive testing method and its applications on asphalt concrete have also been implemented successfully. The test is carried out manually by inducing an impact in order to excite the test specimen and taking measurements of the vibrational response. LÄS MER