Sökning: "Carbon dioxide CO2"

Visar resultat 6 - 10 av 321 avhandlingar innehållade orden Carbon dioxide CO2.

1. 6. Impacts of global change on primary production in northern lakes

   Författare :Isolde Callisto Puts; Ann-Kristin Bergström; Jenny Ask; Tom H. Andersen; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Primary production; global change; warming; browning; lake; carbon dioxide; organic carbon; inorganic carbon; boreal; arctic; DOC; DIC; CO2; allochthonous organic carbon; benthic; periphyton; environmental change; miljöförändringar; environmental science; miljövetenskap; biology; biologi; climate change; klimatförändringar;

   Sammanfattning : Algae are primary producers, a major component of the aquatic foodweb, and changes in primary production affect aquatic ecology in general. Global changes such as warming, recovery of acidification and changes in land-use have caused warming and browning of northern lakes. LÄS MER

3. 7. Biophysical controls on CO2 evasion from Arctic inland waters

   Författare :Gerard Rocher-Ros; Reiner Giesler; Ryan A. Sponseller; Ann-Kristin Bergström; Paul del Giorgio; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Inland waters; carbon dioxide; organic carbon; inorganic carbon; arctic; CO2 evasion; DOC; DIC; streams; metabolism; oxygen; Limnology; limnologi;

   Sammanfattning : CO2 evasion to the atmosphere from inland waters is a major component of the global carbon (C) cycle. Yet spatial patterns of CO2 evasion and the sources of C that fuel evasion remain poorly understood. LÄS MER

4. 8. Factors regulating the origin and magnitude of carbon dioxide emissions from high-latitude lakes

   Författare :Hendricus Verheijen; Jan Karlsson; Cristian Gudasz; David A. Seekell; Marcus Klaus; Anne Ojala; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; lake; carbon dioxide; organic carbon; inorganic carbon; arctic; emission; environmental science; miljövetenskap; climate change; klimatförändringar; Physical Geography; naturgeografi;

   Sammanfattning : Lake ecosystems receive, transmit and process terrestrial carbon and thereby link terrestrial, aquatic and global carbon cycles. Most lakes evade CO2 to the atmosphere, but the annual magnitude of CO2 evasion, as well as sources and mechanisms underpinning CO2 evasion from lakes are still largely unresolved. LÄS MER

5. 9. Freshwater methane and carbon dioxide fluxes : Spatio-temporal variability and an integrated assessment of lake and stream emissions in a catchment

   Författare :Sivakiruthika Natchimuthu; David Bastviken; Åsa Danielsson; Peter A. Raymond; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Lakes; streams; spatio-temporal variability; CH4 flux; CO2 flux; gas transfer velocity; Sjöar; vattendrag; rumsliga och tidsmässiga variationer; CH4-flöden; CO2-flöden; gasutbyteshastighet;

   Sammanfattning : Freshwater bodies such as lakes and streams release the greenhouse gases methane (CH4) and carbon dioxide (CO2) into the atmosphere. Global freshwater CH4 and CO2 emissions have been estimated to be of a similar magnitude to the global land or ocean carbon sink, and are thus significant components of global carbon budgets. LÄS MER

7. 10. 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