Sökning: "carbonaceous"

Visar resultat 16 - 20 av 60 avhandlingar innehållade ordet carbonaceous.

  1. 16. Computational studies of graphene and single walled carbon nanotube growth and carbonaceous polymeric nanocomposites

    Författare :Shayesteh Haghighatpanah; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Graphene; functionalization; carbon nanotube; Monte Carlo; tight binding; polyacrylonitrile; polyethylene; molecular mechanics; molecular dynamics.;

    Sammanfattning : Graphene and single walled carbon nanotube (SWNT) has attracted a lot of attention in different fields of science due to its unique electrical, mechanical, and optical properties. Controlling the growth of graphene and SWNT is a very topical subject and critical for producing material with desired properties since their properties are highly dependent on their atomic structure and it is often desirable that the material contains very few or (if possible) no defects. LÄS MER

  2. 17. Unlocking the hidden diversity of organic-walled microfossils from the early Cambrian of North Greenland

    Författare :Elise Wallet; Sebastian Willman; Ben Slater; Graham Budd; Charles H. Wellman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cambrian; acritarchs; organic-walled microfossils; small carbonaceous fossils; Greenland; diversity; disparity; taxonomy; taphonomy; Crustacea; plankton; Historical Geology and Paleontology; Historisk geologi och paleontologi;

    Sammanfattning : The early Cambrian Buen Formation of North Greenland is celebrated for hosting one of the oldest Cambrian Burgess Shale-type deposits known to date – the Sirius Passet Lagerstätte. Further south in a shallower shelf facies belt, the Buen Formation yielded organic-walled microfossils (OWMs) that were originally described with a focus on acritarchs. LÄS MER

  3. 18. Catalyst Deactivation by Coke Formation. A Study of the Carbonaceous Layer on a Used Hydrogenation Catalyst

    Författare :Åsa Wrammerfors; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The carbonaceous layer, formed on a Ni/SiO2 catalyst, and its influence on the selectivity in a hydrogenation reaction have been studied. The model reaction system studied was the consecutive hydrogenation of 2-ethyl-hexenal: Exposure of the catalyst to 2-ethyl-hexenal or cyclopentadiene at elevated temperatures before the hydrogenation, yielded an increased selectivity toward the formation of 2-ethyl-hexanal. LÄS MER

  4. 19. Characteristics of Particulate Emissions from Low Temperature Combustion and Renewable Fuels : Aerosol Mass Spectrometry of Refractory Carbonaceous Particles

    Författare :Vilhelm Malmborg; NanoLund: Centre for Nanoscience; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Emissions; Soot; BC; BrC; ROS; SP-AMS; MiniCAST; Diesel Engine; HVO; RME; Cook Stove; Emissions; Soot; BC; BrC; SP-AMS; ROS; MiniCAST; Diesel Engine; HVO; RME; Cook Stove;

    Sammanfattning : Particulate air pollution is one of the major causes of premature death in the world, and combustion-derived soot emissions contribute strongly to the particulate pollution to which humans are exposed. Black carbon (BC) is one such emission and denotes soot with strong light absorption in the ultraviolet to infrared spectrum. LÄS MER

  5. 20. The impact of airway-irritating exposure and wet work on subjects with allergy or other sensitivity : epidemiology and mechanisms

    Författare :Pernilla Wiebert; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Air pollution; allergic rhinitis; allergy; asthma; blood; carbonaceous; circulation; clearance; cohort; dermatitis; epidemiology; exposure assessment; Indium-111; inhalation; job-exposure matrix; lung; occupation; retention; Technegas generator; Technetium-99m; translocation; ultrafine particles;

    Sammanfattning : The prevalence of asthma and allergies is increasing, which means that the proportion of workers on the labour market with allergy or other sensitivity also increases. It is as of yet not known to what extent these persons with an elevated sensitivity in the airways or the skin are affected by exposure to irritating substances at work. LÄS MER