Sökning: "air conductivity"

Visar resultat 1 - 5 av 44 uppsatser innehållade orden air conductivity.

  1. 1. Humidity dependent conductivity of air in HVDC applications and the role of surfaces

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Fasta tillståndets fysik

    Författare :Erik Svensson; [2023]
    Nyckelord :HVDC; humidity; air conductivity; thin films; HVDC; luftfuktighet; luftkonduktivitet; tunna filmer;

    Sammanfattning : High Voltage Direct Current (HVDC) bushings are insulated devices designed to facilitate the safe passage of electric current across an earthed barrier. Understanding air conductivity is of utmost importance in the design of HVDC components, which is determined by ion density and ion mobility. LÄS MER

  3. 2. Review and Design of DC Electrical Field Measurement Systems and Related Developments : For Measurements Around HVDC Cable Terminations

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Emil Bergvall; [2023]
    Nyckelord :DC Field Probe; Measurement Systems; Electric Fields; Cable Termination; Ion Drift; Conductivity; HVDC; Field Mill; Field Simulations; Positioning System; MEMS; Electro-Optics; DC Fält Prob; Mätsystem; Elektriska Fält; Kabelavslut; Jondrift; Ledningsförmåga; HVDC; Fältkvarn; Fält Simulationer; Positioneringsystem; MEMS; Elektro-Optik;

    Sammanfattning : With power generation and consumption placed further away from each other, with for example increased offshore power production, the need for HVDC transmission systems increases. As voltage levels in the HVDC transmission system are raised, the losses can be decreased, enabling efficient power transfer over longer distances. LÄS MER

  4. 3. Characterisation of Ionic Liquid doped Polybenzimidazole Membranes for Application in High-Temperature Proton Exchange Membrane Fuel Cells

    Master-uppsats, Lunds universitet/Kemiteknik (CI)

    Författare :Adam Jacobsson Trönndal; [2023]
    Nyckelord :Fuel cells; Phosphoric acid; Polybenzimidazole; PA-PBI; Ionic liquid; IL; High temperature proton exchange membrane fuel cell; HT-PEMFC; Electrochemical impedance spectroscopy; EIS; IL-PBI; Chemical engineering; Technology and Engineering;

    Sammanfattning : In this study four membranes were tested and evaluated against each other for use in high-temperature proton exchange membrane fuel cell (HT-PEMFC) applications. A phosphoric acid (PA) doped polybenzimidazole (PBI) membrane, was used as a reference as the current state-of-the-art. LÄS MER

  5. 4. Evaluating a new hydraulic implementation in LPJ-GUESS for three sites in north Europe

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Carl Holmquist; [2023]
    Nyckelord :Physical Geography and Ecosystem analysis; LPJ-GUESS; drought; sensitivity analysis; evapotranspiration; gross primary production; hydraulic parameters; boreal forest.; Earth and Environmental Sciences;

    Sammanfattning : Drought is projected to increase in frequency and intensity and impacts trees with increased water stress and increased mortality rate. Water stresses can cause hydraulic failure-related mortality or carbon starvation due to tree species having different strategies to deal with water stresses. LÄS MER

  7. 5. Numerical study of a jet impacting a heated object

    Kandidat-uppsats, Karlstads universitet/Institutionen för ingenjörs- och kemivetenskaper (from 2013)

    Författare :Moutaz Hammoud; [2023]
    Nyckelord :Numerical model; COMSOL Multiphysics; Heat transfer; Impinging jets.;

    Sammanfattning : Heat transfer brought about by impinging jets is common in several industrialapplications such as the cooling of heated objects. The purpose of this investigationis to create a numerical model of an impacting jet, then to use it in parametricresearch and in the cooling of an electronic device. LÄS MER