Sökning: "Polyethylenes"

Hittade 5 avhandlingar innehållade ordet Polyethylenes.

  1. 1. Electrical properties of thermally aged polyethylenes and of polyethylenes containing voltage stabilisers

    Författare :Patrik A. Roseen; KTH; []
    Nyckelord :;

    Sammanfattning : The use of polyethylene (PE) in electrical applications athigh voltages requires a certain resistance of the material topartial discharges (PDs). The space charge behaviour of PE isof great importance when PE is used as insulator inhigh-voltage DC cables. LÄS MER

  3. 2. Wear and Fixation of the acetabular component : in vivo evaluation of different polyethylenes and modes of fixation in total hip arthroplasty

    Författare :Stephan Maximilian Röhrl; Kjell Gunnar Nilsson; Bo Nivbrant; Lars Nordsletten; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Surgery; total hip arthroplasty; acetabular component; wear; fixation; osteolysis; Radiostereometry; RSA; Kirurgi; Surgery; Kirurgi; ortopedi; Orthopaedics;

    Sammanfattning : Polyethylene wear and micromotion of the implant play an important role in multifactorial etiology of osteolysis leading to aseptic loosening of the acetabular components. Despite excellent results in primary total hip arthoplasty in a 10-15 year perspective there are still unsolved problems. LÄS MER

  4. 3. ALTERNATIVE POLYETHYLENE CROSSLINKING CONCEPTS FOR POWER CABLE INSULATION

    Författare :Massimiliano Mauri; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; epoxy; crosslinking; HVDC; polymer blends; click-chemistry; polyethylene; Renewable Energy; High-voltage insulation;

    Sammanfattning : We currently witness an accelerating shift from fossil energy sources to renewables driven by the urgent need to reduce carbon emissions. Wind, solar and hydro power is most abundant in places far away from the end user, which necessitates the efficient transport of electricity over long distances. LÄS MER

  5. 4. Simulations of Semi-Crystalline Polymers and Polymer Composites in order to predict Electrical, Thermal, Mechanical and Diffusion Properties

    Författare :Fritjof Nilsson; Mikael Hedenqvist; Gerhard Goldbeck; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Several novel computer simulation models were developed for predicting electrical, mechanical, thermal and diffusion properties of materials with complex microstructures, such as composites, semi-crystalline polymers and foams. A Monte Carlo model for simulating solvent diffusion through spherulitic semicrystalline polyethylene was developed. LÄS MER

  7. 5. On the Dielectric Losses of Polyethylene at Medium and High Frequencies

    Författare :Martin Strååt; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dielectric properties; foaming; crystallinity; polyethylene; frequency; porosity;

    Sammanfattning : AbstractAs mobile communication moves from 3G to 4G, the bandwidth used will be extended from 2 GHz to 5 GHz. The propagation loss is related to the 2.6:th power of frequency, thus a large increase in power consumption may be expected. LÄS MER