Sökning: "dielectric materials"

Visar resultat 1 - 5 av 154 avhandlingar innehållade orden dielectric materials.

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

    Författare :Martin Strååt; [2008]
    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

  2. 2. Enhancements in Dielectric Response Characterization of Insulation Materials

    Författare :Xiangdong Xu; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; harmonic limited waveform; air reference method; contact-free electrode; geometric corrections.; frequency domain spectroscopy; Dielectric characterization;

    Sammanfattning : The increasing demand of integrating various renewable energy recourses in power system requires extensive use of power electronic solutions, such as HVDC and FACTS, as these techniques allow energy conversion between different frequencies and serves to stabilize the network. Consequently, electric stresses other than traditional 50/60 Hz sinusoidal voltage stress are acting on high voltage insulation materials. LÄS MER

  3. 3. Cellulose-based electrical insulation materials : Dielectric and mechanical properties

    Detta är en avhandling från KTH Royal Institute of Technology

    Författare :Rebecca Hollertz; KTH.; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; dielectric materials; electrical insulation; nanocellulose; nanoparticles; streamer; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : The reliability of the generation and distribution of electricity is highly dependent on electrical insulation and is essential for the prosperity of our society and a ubiquitous part of our everyday life. The present study shows how some important material properties affect the electrical properties of cellulose-based electrical insulation systems which are used together with mineral oil in high-voltage transformers. LÄS MER

  4. 4. Electro-Optical Na0.5K0.5NbO3 Films

    Detta är en avhandling från Stockholm : KTH

    Författare :Mats Blomqvist; KTH.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Functional materials; ferroelectrics; sodium potassium niobates; thin films; rf-magnetron sputtering; waveguiding; refractive index; prism-coupling; electro-optic effects; dielectric tunability; Funktionella material; TECHNOLOGY Materials science Functional materials; TEKNIKVETENSKAP Teknisk materialvetenskap Funktionella material;

    Sammanfattning : Ferroelectric oxides are a group of advanced electronic materials with a wide variety of properties useful in applications such as memory devices, resonators and filters, infrared sensors, microelectromechanical systems, and optical waveguides and modulators.Among the oxide perovskite-structured ferroelectric thin film materials, sodium potassium niobate or Na0. LÄS MER

  5. 5. Multi-functional composite materials CFRP thin film capacitors

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Tony Carlson; Luleå tekniska universitet.; [2011]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science - Functional materials; Materials science - Other material science; Teknisk materialvetenskap - Funktionella material; Teknisk materialvetenskap - Övrig teknisk materialvetenskap; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Sammanfattning : The use of lightweight materials in structural applications is ever increasing. Today, lightweight engineering materials are needed to realise greener, safer and more competitive products. LÄS MER