Avancerad sökning

Hittade 5 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. On the Optics and Surface Physics of Liquid Crystals

    Författare :Pontus Jägemalm; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; deformed helix; anchoring; short-pitch; SiO; homogeneous models; two-fold degenerate alignment; Berreman; bistable alignment; optical activity;

    Sammanfattning : Good knowledge about optics and surface physics of liquid crystals is indispensable when utilising them for applications, such as liquid crystal displays (LCDs). However, they are also two central subjects in fundamental research on liquid crystals. LÄS MER

  3. 2. On the linear electro-optic effect in short-pitch cholesterics

    Författare :Per Rudquist; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  4. 3. Rail Corrugation Growth on Curves

    Författare :Peter Torstensson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; simulation; track and wheelset structural flexibility; small radius curves; short-pitch rail corrugation; dynamic vehicle–track interaction; test rig and field measurements; wear;

    Sammanfattning : Short-pitch rail corrugation that may develop on the low (inner) rail on small radius curves causes increased noise and vibration levels on railway networks worldwide. In lack of a generally applicable treatment, track authorities are forced to run expensive rail grinding programs on a regular basis to manage these problems. LÄS MER

  5. 4. Rail Corrugation Growth on Curves

    Författare :Peter Torstensson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; short-pitch rail corrugation; rotating flexible wheelset model; small radius curves; prediction of long-term roughness growth; plastic deformation; non-Hertzian and non-steady wheel‒rail contact; wear; rutting corrugation;

    Sammanfattning : The development of periodic irregularities with distinct wavelengths (corrugation) on the low rail of small radius curves is studied through mathematical modelling, numerical simulations, field measurements and laboratory investigations. One year of monitoring of roughness on the low rail of a 120 m radius curve on the metro of Stockholm Public Transport (SL) showed severe growth of rail corrugation with wavelengths of about 5 cm and 8 cm. LÄS MER

  7. 5. Studies on Domain Dynamics in Nonlinear Optical Ferroelectric Oxide Crystals

    Författare :Hoda Kianirad; Fredrik Laurell; Carlota Canalias; Sakellaris Mailis; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics;

    Sammanfattning : Nonlinear optical frequency conversion is the key technology for modifying laser output radiation, in order to target specific applications. The most powerful technique to obtain tailored second-order nonlinear interactions is the quasi-phasematching (QPM) approach. LÄS MER