Sökning: "Optical sensing"

Visar resultat 1 - 5 av 226 avhandlingar innehållade orden Optical sensing.

  1. 1. Mid-infrared photonic devices for on-chip optical gas sensing

    Författare :Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mid-infrared; mid-IR; photonics; silicon photonics; gas sensing; optical sensing; optical gas sensing; spectroscopy; absorption; dispersion; carbon dioxide; CO2; CO2 sensing; trace gas; ethanol sensing; alcohol sensing; waveguide; photonic waveguide; ring resonator; nanowire; nanoheater; emitter; thermal source; bolometer; microbolometer; thermal detector; high frequency; 3 omega method; plasmonic; platinum; Kanthal; silicon-on-insulator; micro-electro-mechanical systems MEMS ; microfabrication; microsystems; microtechnology; nanotechnology; Optik och fotonik; Optics and Photonics; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. LÄS MER

  3. 2. Cavity enhanced optical sensing

    Författare :Isak Silander; Ove Axner; Aleksandra Foltynowicz; Jong Chow; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical resonators; Fiber Laser; Parametric oscillators; Optical frequency comb; Infrared; Spectroscopy heterodyne; Spectroscopy molecular; Absorption; Dispersion; Lineshapes; Optical standards and testing; Refractivety measurements;

    Sammanfattning : An optical cavity comprises a set of mirrors between which light can be reflected a number of times. The selectivity and stability of optical cavities make them extremely useful as frequency references or discri­mi­nators. LÄS MER

  4. 3. Optical remote sensing of industrial gas emission fluxes

    Författare :John Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical remote sensing; DOAS; gas emission; absorption spectroscopy; VOC; flux measurement; solar occultation; FTIR; formaldehyde;

    Sammanfattning : Mobile optical remote sensing techniques offer promising possibilities to quantify and geographically attribute local industrial gaseous emissions to the atmosphere. Studies have repeatedly shown that such emissions are often poorly understood, underestimated, and thereby not properly accounted for in emission inventories and regional atmospheric chemistry models, especially for emissions of VOCs. LÄS MER

  5. 4. Remote Sensing of Urbanization and Environmental Impacts

    Författare :Jan Haas; Yifang Ban; Costas Cartalis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Remote Sensing; Urbanization; Land Use Land Cover LULC ; Environmental Impact; Landscape Metrics; Ecosystem Services; Geodesy and Geoinformatics; Geodesi och geoinformatik;

    Sammanfattning : This thesis aims to establish analytical frameworks to map urban growth patterns with spaceborne remote sensing data and to evaluate environmental impacts through Landscape Metrics and Ecosystem Services. Urbanization patterns at regional scale were evaluated in China's largest urban agglomerations and at metropolitan scale in Shanghai, Stockholm and Beijing using medium resolution optical satellite data. LÄS MER

  7. 5. Remote Sensing of Urbanization and Environmental Impacts

    Författare :Jan Haas; Yifang Ban; Lars Eklund; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Remote Sensing; Classification; Land Use Land Cover; Support Vector Machine; Random Forest; Urbaniztion; Environmental Impact; Landscape Metrics; Ecosystem Services; Geomatik; Geomatics;

    Sammanfattning : The unprecedented growth of urban areas all over the globe is nowadays maybe most apparent in China having undergone rapid urbanization since the late 1970s. The need for new residential, commercial and industrial areas leads to new urban regions challenging sustainable development and the maintenance and creation of a high living standard as well as the preservation of ecological functionality. LÄS MER