Search for dissertations about: "Carbon"

Showing result 21 - 25 of 3408 swedish dissertations containing the word Carbon.

2. 21. Impacts of global change on primary production in northern lakes

   Author : Isolde Callisto Puts; Ann-Kristin Bergström; Jenny Ask; Tom H. Andersen; Umeå universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 22. Northern Permafrost Region Soil Carbon Dynamics since the Last Glacial Maximum : a terrestrial component in the glacial to interglacial carbon cycle

   Author : Amelie Lindgren; Gustaf Hugelius; Peter Kuhry; Fortunat Joos; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Soil organic carbon; Permafrost; Peat; Loess; Vegetation; Biome reconstruction; Last Glacial Maximum; Deglaciation; Glacial-interglacial cycle; Carbon cycle; Physical Geography; naturgeografi;

   Abstract : At the Last Glacial Maximum (LGM), after ~100,000 years of relatively cold temperatures and progressively lower atmospheric carbon dioxide (CO2) concentrations, CO2 levels reached ~180 ppm, which is less than half of what we see today in a much warmer world (~400 ppm). Although much of this increase since the LGM is due to human-induced emissions, about 100 ppm of this increase can be attributed to natural variations seen over glacial to interglacial cycles. READ MORE

5. 23. Toward Carbon based NEMS

   Author : Farzan Alavian Ghavanini; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbon nanotubes CNT ; Nanoelectromechanical systems; and CMOS compatibility ; CNT-based switch; vertically aligned carbon nanofibers VACNF ; NEMS;

   Abstract : A systematic analysis and assessment of carbon nanotube (CNT) based NEMS switches is presented and their features are compared to typical complementary metal-oxide-semiconductor (CMOS) performance parameters. It is shown that CNT-based switches with considerably smaller leakage current compared to CMOS switches can be realized. READ MORE

6. 24. Cellulose derived carbon dots : From synthesis to evaluation as multifunctional building blocks in biomedical scaffolds

   Author : Nejla Benyahia Erdal; Minna Hakkarainen; Jukka Seppälä; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; microwave; carbon dots; polycaprolactone; scaffold; mineralization; drug loading; cellulosa; mikrovågor; kolnanopartiklar; polykaprolakton; stödmatris för vävnadsregenerering; mineralisering; läkemedelsbärare; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : The implementation of biobased and biodegradable polymeric materials in biomedical applications is often coupled with issues related to their insufficient mechanical properties or limited bioactivity. In this thesis, a perspective on valorization of biomass is presented, demonstrating the transformation of cellulose into biobased carbon nanomaterials with the potential to serve as multifunctional property enhancers in polycaprolactone (PCL) scaffold materials for tissue engineering. READ MORE

7. 25. Carbon-nanotube-based nanoelectromechanics

   Author : Magnus Jonsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; electromechanical instabilities; multi-mode excitations; NEMS; suspended carbonnanotubes; Nanoelectromechanicalsystems; non-linearresonances; nanorelay; carbon nanotubes; surface forces;

   Abstract : Carbon nanotubes, a novel material with extraordinary mechanical and electrical properties, are good candidates for designing nanoelectromechanical systems. The typical length scale of these systems is nanometers and an important characteristic is a coupling between electrical and mechanical degrees of freedom. READ MORE