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PAN is first thermally oxidized in air at 230 °C to form an oxidized PAN fiber and then carbonized above 1000 °C in inert atmosphere to make carbon fibers found in a variety of both high-tech and common daily applications such as civil and military aircraft primary and secondary structures, missiles, solid propellant rocket motors, pressure ...
Carbon fibers or carbon fibres (alternatively CF, graphite fiber or graphite fibre) are fibers about 5 to 10 micrometers (0.00020–0.00039 in) in diameter and composed mostly of carbon atoms. [1] Carbon fibers have several advantages: high stiffness, high tensile strength, high strength to weight ratio, high chemical resistance, high ...
Atmospheric chemistry is a branch of atmospheric science that studies the chemistry of the Earth's atmosphere and that of other planets. This multidisciplinary approach of research draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology, climatology and other disciplines to understand both natural and human-induced changes in atmospheric ...
45–55% carbon; 35–45% oxygen; 3–5% hydrogen; 1–4% nitrogen; The molecular weights of these compounds can vary drastically, depending on if they repolymerize or not, from 200 to 20,000 amu. Up to one-third of the carbon present is in aromatic compounds in which the carbon atoms form usually six
Yet it is the twelfth most common element there. In the rock of the lithosphere, carbon commonly occurs as carbonate minerals containing calcium or magnesium. It is also found as fossil fuels in coal and petroleum and gas. Native forms of carbon are much rarer, requiring pressure to form. Pure carbon exists as graphite or diamond. [1]
As a result of CFCs contributing to ozone depletion in the upper atmosphere, the manufacture of such compounds has been phased out under the Montreal Protocol, and they are being replaced with other products such as hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) [1] including R-410A, R-134a and R-1234yf. [2] [3] [4]
Carbon-based compounds form the basis of all known life on Earth, and the carbon-nitrogen-oxygen cycle provides a small portion of the energy produced by the Sun, and most of the energy in larger stars (e.g. Sirius). Although it forms an extraordinary variety of compounds, most forms of carbon are comparatively unreactive under normal conditions.
Mordor Macula, a dark region on Charon's north pole. The region is stained a dark brown by deposits of tholins. Tholins (after the Greek θολός (tholós) "hazy" or "muddy"; [1] from the ancient Greek word meaning "sepia ink") are a wide variety of organic compounds formed by solar ultraviolet or cosmic ray irradiation of simple carbon-containing compounds such as carbon dioxide (CO