Search for dissertations about: "CO2 sensing"

Showing result 1 - 5 of 25 swedish dissertations containing the words CO2 sensing.

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

    Author : Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; 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; Optics and Photonics; Optik och fotonik; Electrical Engineering; Elektro- och systemteknik;

    Abstract : 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. READ MORE

  2. 2. Integration of graphene into MEMS and NEMS for sensing applications

    Author : Xuge Fan; Frank Niklaus; Peter Steeneken; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Micro-electromechanical systems MEMS ; Nano-electromechanical systems NEMS ; heterogeneous 3D integration; Graphene; single-layer graphene; double-layer graphene; bilayer graphene; chemical vapor deposition CVD ; suspended graphene beams; suspended graphene membranes; doubly clamped; fully clamped; silicon on insulator SOI ; vapor hydrofluoric acid VHF ; Young’s modulus; built-in stress; built-in tension; piezoresistivity; gauge factor; accelerometer; resonators; electromechanical sensing; advanced transducers; humidity; gas sensing; sensitivity; CO2 sensing; graphene grain boundary; line defects; optical microscopy; wire bonding; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis presents a novel approach to integrate chemical vapor deposition (CVD) graphene into silicon micro- and nanoelectromechanical systems (MEMS/NEMS) to fabricate different graphene based MEMS/NEMS structures and explore mechanical properties of graphene as well as their applications such as acceleration sensing, humidity sensing and CO2 sensing. The thesis also presents a novel method of characterization of CVD graphene grain boundary based defects. READ MORE

  3. 3. Microfluidics at High Pressures : Understanding, Sensing, and Control

    Author : Martin Andersson; Lena Klintberg; Cyril Aymonier; Uppsala universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; High-pressure microfluidics; supercritical CO2; compressible flow; relative permittivity; integrated electrodes; Teknisk fysik med inriktning mot mikrosystemteknik; Engineering Science with specialization in Microsystems Technology;

    Abstract : This thesis explores understanding, sensing, and control in high-pressure microfluidics. The high-pressure regime allows fluids to be forced through narrow channels at substantial speed and creates conditions for fluids of high density and low viscosity—features desired in flow-based chemical analyses. READ MORE

  4. 4. Air-Sea Fluxes of CO2 : Analysis Methods and Impact on Carbon Budget

    Author : Maria Norman; Anna Rutgersson; Erik Sahlée; William Drennan; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; air-sea exchange; carbon dioxide; Baltic Sea; eddy-covariance method; inertial dissipation method; cospectral-peak method; Baltic Sea measurements; CO2 fluxes; Galathea 3 expedition; Baltic Sea modeling; water-side convection; coastal upwelling; carbon budget; Meteorology; Meteorologi;

    Abstract : Carbon dioxide (CO2) is an important greenhouse gas, and the atmospheric concentration of CO2 has increased by more than 100 ppm since prior to the industrial revolution.  The global oceans are considered an important sink of atmospheric CO2, since approximately one third of the anthropogenic emissions are absorbed by the oceans. READ MORE

  5. 5. Carbon exchange in boreal ecosystems: upscaling and the impacts of natural disturbances

    Author : Julia Kelly; BECC - Biodiversity and Ecosystem services in a Changing Climate; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Carbon fluxes; CH4; Climate change; CO2; Drought; Ecosystem respiration; Forest; Peatland; Remote sensing; Temperature; Thermal camera; UAV; Wildfire;

    Abstract : Boreal forests and peatlands are globally significant carbon stores but they are threatened by rising air temperatures and changes in precipitation regimes and the frequency of natural disturbances. Predicting how the boreal biome will respond to climate change depends on being able to accurately model and upscale the greenhouse gas fluxes between these ecosystems and the atmosphere. READ MORE