Sökning: "microwave"

Visar resultat 31 - 35 av 638 avhandlingar innehållade ordet microwave.

  1. 31. Enhancing Tropospheric Humidity Data Records from Satellite Microwave and Radiosonde Sensors

    Författare :Isaac Moradi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CDR; climate; microwave; radiosonde; water vapor; remote sensing; antenna; homogenization; humidity; meteorology; troposphere; radio-frequency;

    Sammanfattning : Water vapor is the most dominant greenhouse gas and plays a critical role in the climate by regulating the Earth's radiation budget and hydrological cycle. A comprehensive dataset is required to describe the temporal and spatial distribution of water vapor, evaluate the performance of climate and weather prediction models in terms of simulating tropospheric humidity, and understand the role of water vapor and its feedback in the climate system. LÄS MER

  3. 32. Fast Chemistry by Microwave Heating : First Descriptions of Highly Enantioselective Microwave Protocols for Metal Catalysis; First Descriptions of in-situ Gas Generation for Fast Combinatorial Microwave Chemistry

    Författare :Nils-Fredrik K. Kaiser; C. O.; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; Farmaceutisk kemi; Pharmaceutical chemistry; Farmaceutisk kemi; Organic Pharmaceutical Chemistry; organisk farmaceutisk kemi;

    Sammanfattning : Microwave heating was applied to different palladium-catalyzed allylic substitution reactions. The use of various nucleophiles demonstrated C-, N-, O- and S- nucleophilicity. High yields and stereopurities of the corresponding alkyls, amides, ethers and sulfones were afforded after only 30 – 120 s of heating. LÄS MER

  4. 33. Microwave characterisation of electrodes and field effect transistors based on graphene

    Författare :MICHAEL ANDERSSON; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Graphene; graphene electrodes; microwave amplifiers; noise measurements; microwave FETs; CVD graphene; noise modelling; FBARs.; nanofabrication; subharmonic resistive mixers; small-signal FET modelling;

    Sammanfattning : The isolation of the two-dimensional material graphene, a single hexagonal sheet of carbon atoms, is believed to trigger a revolution in electronics. Theory predicts unprecedented carrier velocities in ideal graphene, from which ultrahigh speed graphene field effect transistors (GFETs) are envisioned. LÄS MER

  5. 34. Modelling Microwave Backscattering from Sea Ice for Synthetic-Aperture Radar Applications

    Författare :Anders Carlström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synthetic-aperture radar; microwave; surface roughness; sea ice; backscattering models;

    Sammanfattning : The spaceborne synthetic-aperture radar (SAR) is considered one of the key instruments for monitoring the ice cover in polar oceans and regional seas. This thesis is concerned with applications of electromagnetic scattering theory and SAR system theory for modelling the response of different types of sea ice in SAR imagery. LÄS MER

  7. 35. Device Technology Based on High Temperature Superconductors and Microwave Breakdown in Gases

    Författare :Martin Löfgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distortion; penetration depth; surface resistance; transmit-receive switch; coupled-grain model; high-power; microwave; pulse; surface impedance; breakdown; propagation; modulator; air; superconductor; transmission line; resonator; coplanar waveguide; plasma;

    Sammanfattning : This thesis deals with two separate fields of microwave technology. The first section treats microwave characterization and applications of high temperature superconducting (HTS) thin films, while the second section treats microwave breakdown in transmit-receive (TR) switches and in air. Within the first section, four main topics are adressed. LÄS MER