Sökning: "accelerated aging"

Visar resultat 1 - 5 av 47 avhandlingar innehållade orden accelerated aging.

  1. 1. Aging effects on commercial lean NOx trap catalysts

    Författare :Jesus De Abreu Goes; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; aging; thermal degradation; sulfur poisoning; characterization; commercial lean NOx traps; NOx storage and reduction;

    Sammanfattning : As a countermeasure to global warming, vehicles with low carbon emissions are being investigated by promoting lean-burn engines and high combustion efficiencies. However, one limitation to the increasing use of these engines is the need to develop corresponding catalytic systems for controlling the nitrogen oxide (NOx) emissions in their lean exhaust. LÄS MER

  2. 2. Silicone Rubber Insulators: Impacts of Material Formulation in Coastal Environment

    Författare :Tomas G Gustavsson; Chalmers University of Technology; []
    Nyckelord :surface characterization; aging; filler level; outdoor insulation; leakage current measurements; material formulation; silicone rubber; polymeric insulators; coastal environment; polydimethylsiloxane PDMS ;

    Sammanfattning : This thesis deals with influences of material formulation on the performance of silicone rubber high voltage insulators in a coastal environment. Samples and insulators with known differences in material compositions have been used in this task. In the first step, a screening test with cylindrical samples was initiated. LÄS MER

  3. 3. Hydrothermal Liquefaction of Lignin into Bio-Oil

    Författare :Huyen Nguyen Lyckeskog; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrothermal conversion; aging; bio-oil; stability; subcritical water; lignin;

    Sammanfattning : Lignin, one of the three main components of lignocellulosic biomass, is the second most abundant organic polymer found on Earth. Nowadays, most of the lignin (almost 99%) produced in the Kraft pulping process is used as internal fuel. LÄS MER

  4. 4. Telomeres and the brain : an investigation into the relationships of leukocyte telomere length with functional and structural attributes of the brain

    Författare :Mikael Wikgren; Karl-Fredrik Norrback; Rolf Adolfsson; Göran Roos; Thomas Karlsson; Brenda Penninx; Umeå universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; APOE; aging; atrophy; brain; cognition; cortisol; depression; hippocampus; HPA axis; MRI; stress; telomere length; white matter hyper-intensities.;

    Sammanfattning : Telomeres are the outermost parts of linear chromosomes. They consist of tandemly repeated non-coding short nucleotide sequences (TTAGGG in all vertebrates), in humans spanning over the last 2 to 15 kilobase pairs of the chromosome. Due to the end-replication problem, telomeres shorten with each cellular division. LÄS MER

  5. 5. Mechanisms of lipofuscin/ceroid accumulation and its impact on the function of the lysosomal system

    Författare :Alexei Terman; Thomas von Zglinicki; Linköpings universitet; []
    Nyckelord :Aging; Autophagocytosis; Centrophenoxine; Ceroid; Lipofuscin; Lysosomes; Oxidative stress; MEDICINE; MEDICIN;

    Sammanfattning : The accumulation of lipofuscin - an electron-dense, autofluorescent, polymeric, intralysosomal substance - is a recognized hallmark of aging postmitotic cells. Ceroid- a substance very close, or perhaps even identical, to lipofuscin - is a characteristic of various pathological processes, such as lysosomal storage diseases, malnutrition, atherosclerosis, oxidative stress, ionizing radiation, etc. LÄS MER