1,721,018 research outputs found
Piezoresistive cement nanocomposites
No full textMethods may include pumping a cement composition containing one or more conductive fillers into an annular region of a wellbore created between a casing and a surface of the wellbore, allowing the cement composition to cure, emplacing a tool for measuring at least one electromagnetic property into the wellbore, and measuring at least one of the cemented casing and the formation. In another aspect, methods may include preparing a cement composition containing one or more conductive fillers, allowing the cement composition to set, and measuring at least one electromagnetic property of the set cement. In yet another aspect, cement compositions may contain a cement, one or more conductive fillers, and a surfactant, wherein the resistivity of the cement composition is less than 10 Ω*
Contact angle measurements to determine the rate of surface oxidation of artists' alkyd paints during accelerated photo-ageing
No full textGrowth of vertically aligned carbon nanotubes by CVD by evaporation of carbon precursors
No full textWe report about the growth of carbon nanotubes, carbon microfibers and other forms of carbon on uncoated silicon and glass substrates, obtained by evaporating either a solid carbon precursor such as camphor or a liquid one such as cyclohexanol. The latter is a cyclic alcohol never used before in this field. The process of synthesis involves the coevaporation of the carbon precursor and ferrocene, used as the catalyst source, in nitrogen atmosphere. The morphology and structure of the samples grown at various substrate temperatures were characterized by Raman and FT-IR spectroscopy, HR-TEM and SEM analysis.At a substrate temperature of about 650 degrees C a 'carpet' of vertically oriented nanotubes, with spare signs of other form of carbons, is obtained on silicon substrate, whereas a disordered carbon nanotubes structure and other carbon form are grown on glass substrates. The results demonstrate the ability of this method to grow carbon nanotubes on uncoated glass substrates
Improving macroscopical physical and mechanical properties of thick layers of aligned multiwall carbon nanotubes by annealing
No full textPhysical and mechanical properties of thick self standing layers of multiwall carbon nanotubes
No full text
- …
