Sökning: "low temperatures"

Visar resultat 1 - 5 av 1214 avhandlingar innehållade orden low temperatures.

  1. 1. Ultra-Low Power InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low noise; InAs AlSb; metamorphic; low power; high frequency; high electron mobility transistor HEMT ; cryogenic; ion implantation;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology for ultra-low power and low noise applications. Due to the low bandgap (0. LÄS MER

  3. 2. Anaerobic digestion of crop residues at low temperatures

    Författare :Irene Bohn; Bioteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bioteknik; Biotechnology; kontroll av utsläpp; Miljöteknik; Environmental technology; pollution control; methanogens; low temperature; crop residues; Anaerobic digestion; farm-scale digestion; fluorescence in situ hybridization;

    Sammanfattning : Biogas is a renewable source of energy. Residues from agriculture contain considerable energy potential and are suitable substrates for biogas production, but in Sweden the utilization of these residues is low. The economic feasibility of biogas production in general is low, and only limited subsidies are provided by the state. LÄS MER

  4. 3. Low-temperature District Heating : Various Aspects of Fourth-generation Systems

    Författare :Helge Averfalk; Sven Werner; Brian Elmegaard; Högskolan i Halmstad; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District heating; low temperature; three-pipe systems; 4GDH-3P; District heating; low temperature; three-pipe systems; 4GDH-3P;

    Sammanfattning : With decreasing heat demand and less availability of high-temperature heat supply in future energy systems, the current district heating systems may experience increased competition on the heat market. A viable option to mitigate increasing competition is to operate systems with lower temperature levels, and the most conceivable way to achieve lower temperature levels is to decrease return temperatures. LÄS MER

  5. 4. InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; metamorphic; high frequency; high electron mobility transistor HEMT ; low power; low noise.; InAs AlSb;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology. The high electron mobility and high peak electron velocity of the InAs channel makes this device technology a potential candidate for low-noise applications operating at very low power dissipation. LÄS MER

  7. 5. Design and Construction of Low-Temperature Scanning Tunnelling Microscope for Spectroscopy

    Författare :Joakim Lindahl; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mechanical properties; thermophysical properties; stepper motor; ultra-high vacuum; inertial-mass; low temperatures; scanning tunneling microscopy; optical propertie; Fysik; Semiconductory physics; Physics; scanning tunneling luminescence; local probe; photon emission; local carrier injection; Halvledarfysik; Fysicumarkivet A:1998:Lindahl;

    Sammanfattning : This thesis discusses some of the fundamental requirements needed to be fulfilled when constructing a low temperature scanning tunnelling microscope (STM). Three different designs, two non-vacuum and one ultra-high vacuum (UHV), based on either inertial-mass or novel stepper motor principles are presented. LÄS MER