Sökning: "Hans Ekström"

Hittade 5 avhandlingar innehållade orden Hans Ekström.

  1. 1. Antenna Integrated Superconducting Mixers

    Författare :Hans Ekström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tapered slotline antenna; mixer; double dipole antenna; superconducting; hot electron; receiver; Niobium; bolometer; trilayer junction; edge junction; Niobium Nitride; SIS;

    Sammanfattning : This thesis investigates the prospects of some different superconducting mixers integrated with planar antennas for the millimeter and submillimeter regime. Two kinds of Superconductor/Insulator/Superconductor (SIS) tunnel junctions for use in mixers have been fabricated; Nb/PbBi edge junctions and Nb trilayer junctions. LÄS MER

  3. 2. Transition Metal Hydrides : Biomimetic Studies and Catalytic Applications

    Författare :Jesper Ekström; Hans Adolfsson; Jonathan Williams; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; transition metals; catalysis; bioinorganic chemistry; hydrides; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

    Sammanfattning : In this thesis, studies of the nature of different transition metal-hydride complexes are described. The first part deals with the enantioswitchable behaviour of rhodium complexes derived from amino acids, applied in asymmetric transfer hydrogenation of ketones. LÄS MER

  4. 3. The influence of biogenic organic compounds on cloud formation

    Författare :Sanna Ekström; Barbara Nozière; Tomas Alsberg; Hans-Christen Hansson; Ernest Weingartner; Stockholms universitet; []
    Nyckelord :biogenic; aerosol; CCN; water-soluble; microorganisms; surfactant; organosulfate; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Aerosols and clouds provide the largest uncertainty in the atmospheric radiation budget. The main focus of this thesis was to investigate the ability of organic compounds in aerosol particles to form clouds, and more specifically those emitted by living organisms. LÄS MER

  5. 4. Divided Exhaust Period on Heavy-Duty Diesel Engines

    Författare :Stefan Gundmalm; Hans-Erik Ångström; Fredrik Ekström; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Due to growing concerns regarding global energy security and environmental sustainability it is becoming increasingly important to increase the energy efficiency of the transport sector. The internal combustion engine will probably continue to be the main propulsion system for road transportation for many years to come. LÄS MER

  7. 5. Medaljens baksida : Instrumentmakaren Daniel Ekström och hans efterföljare i 1700-talets Sverige

    Författare :Olov Amelin; Uppsala universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; History of science and ideas; Scientific instruments; astronomy; land surveying; technology transfer; 18th century science; Academy of sciences; Idé- och lärdomshistoria; History of science and ideas; Idé- o lärdomshistoria; idé- och lärdomshistoria; History Of Sciences and Ideas;

    Sammanfattning : This thesis deals with scientific instrument-making in Sweden in the 18th century with an overview of the craft in the second half of the 17th century. The main character in this book, Daniel Ekström is introduced in chapter two. LÄS MER