Sökning: "CAVITIES"

Visar resultat 1 - 5 av 213 avhandlingar innehållade ordet CAVITIES.

1. 1. Influence of Segregants on Creep Fracture in Powder Metallurgical Martensitic Stainless Steel

   Författare :Mats Norell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AES; creep; segregants; powder metallurgy; prior particle boundaries; atomisation; SIMS; martensitic stainless steel; ESCA; cavities; powder surfaces;

   Sammanfattning : This thesis deals with the behaviour of segregants in Powder Metallurgical (PM) 10%Cr steel and their impact on creep fracture. Particular interest is taken in determining the reaction products involved in creep cavitation and how these are connected to the powder surface reactions during the gas atomisation and consolidation (hot isostatic pressing). LÄS MER

3. 2. Initial Oxidation of β-NiAl(Pt) Coatings and Model Alloys

   Författare :Henrik Svensson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FIB-SEM; SEM; #946; TEM; Diffusion Coatings; Metal-Oxide Interface; High Temperature Oxidation; Cavities; Platinum; -NiAl;

   Sammanfattning : The aim of this work was to investigate the oxidation properties of NiAl coatings and model materials during high temperature oxidation. One of the important issues was to elucidate the beneficial role of Pt additions. A better understanding of the involved processes provides a key for the further improvement of the coatings performance. LÄS MER

4. 3. Detection of Partial Discharges at Fast Rising Voltages

   Författare :Thomas Hammarström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Partial discharges; cavities; repetitive voltages; high dV dt.; square like voltages; short rise time; measurements;

   Sammanfattning : The present demand for higher efficiency and flexibility in the energy sector has ledto an increased use of power electronic generated waveforms as these allow energyconversion between different frequencies including DC. The generated waveformsare usually synthesized by so called Pulse Width Modulation (PWM) techniques,where the desired waveform is approximated by a number of square shaped pulseswith a short rise time. LÄS MER

5. 4. Partial Discharges at Fast Rising Voltages

   Författare :Thomas Hammarström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; short rise time; cavities; high dV dt.; measurements; Partial discharges; square like voltages; repetitive voltages;

   Sammanfattning : The present demand for higher efficiency and flexibility in the energy sector has led to an increased use of power electronic generated waveforms as these allow energy conversion between different frequencies including DC. The generated waveforms are usually synthesized by so called Pulse Width Modulation (PWM) techniques, where the desired waveform is approximated by a number of square shaped pulses with a short rise time. LÄS MER

7. 5. InP-based photonic crystals : Processing, Material properties and Dispersion effects

   Författare :Audrey Berrier; Srinivasan Anand; Alfred Forchel; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photonic crystals; indium phosphide; photonic bandgap; Bloch modes; slow light; dispersion; coupled cavity waveguides; chemically assisted ion beam etching; lag effect; cavities; optical losses; carrier transport; carrier lifetimes; negative refraction; photonic bandstructure; Physics; Fysik;

   Sammanfattning : Photonic crystals (PhCs) are periodic dielectric structures that exhibit a photonic bandgap, i.e., a range of wavelength for which light propagation is forbidden. The special band structure related dispersion properties offer a realm of novel functionalities and interesting physical phenomena. LÄS MER