Showing papers in "Carbon in 1982"

TL;DR: In this article, the first-order Raman scattering intensity in terms of the vibrational density of states of a single graphite layer weighted by the electron-phonon couping of the modes to the electromagnetic radiation is derived.

TL;DR: In this article, the chemistry of carbonization has been investigated using advanced analytical techniques such as: chromatographic methods, thermal analysis, mass spectroscopy, and electron and nuclear magnetic resonance.

TL;DR: Several series of activated carbons have been prepared from almond shells by mean of carbonization in a flow of nitrogen followed by activation of carbon dioxide as mentioned in this paper, which leads to the appearance of micropores and a considerable increase in surface area.

TL;DR: In this paper, the catalytic effects of a series of alkali metal salts in promoting the gasification of a graphite powder by carbon dioxide and water vapor have been studied by thermogravimetry between 700 and 1100°C.

TL;DR: In this paper, it was shown that the chemical reactivity of carbons toward oxidation reagents depends primarily on their degree of crystalline organization, and several types of carbon surface groups can be evidenced on carbons.

TL;DR: In this article, a phase contrast high-resolution transmission electron microscopy (HEM) image of five carbons of high surface area, ~ 2000-3000 m2g−1, were studied by adsorption of carbon dioxide at 195 and 273 K. The size and shape of supermicroporosity can be deduced from micrographs.

TL;DR: In this paper, a 3,5-Dimethylphenol-formaldehyde resin was carbonized with NaOH and it was found that as the amount of NaOH increases, the temperature of the hydrogen gas evolution is significantly lowered and its amount increases enormously.

TL;DR: In this paper, a set of lignocellulosic precursors of widely varying composition was pyrolyzed under argon at 15°C/min to 500°C.

TL;DR: In this paper, a review of the behavior of graphite subjected to irradiation in nuclear reactors is presented, with particular emphasis on graphite crystallites and their relationship to the macroscopic dimensional changes of polycrystalline graphites.

TL;DR: In this paper, pyrolysis under argon at varying heating rates to final temperatures of 500-900°C was used to extract lignocellulosic precursors from plant tissues.

TL;DR: In this paper, carbon deposition from aliphatic and aromatic hydrocarbons over metal catalysts was carried out over the temperature range 700-1025 K using a microbalance coupled with a tubular reactor.

TL;DR: In this article, a Couette-flow instrument has been modified for measuring the apparent viscosity of mesophase pitch, circumventing most of the experimental difficulties, and the reliability of this apparatus has been tested by cross checking the observed apparent viscoities with the values measured from two other rheometers, Instron Capillary and Seiscor/Han, for a number of fluids.

TL;DR: In this article, various asphalts extracted from crude oils by light n-alcanes were studied by elemental analysis, conventional transmission microscopy, and X-ray diffraction, and the extent of the molecular orientation depends only on the opposing influence of the hydrogens and of heteroatoms such as oxygen, sulfur and nitrogen.

TL;DR: In this paper, four morphologically distinct forms of particulate carbon can be recognized in various types of soot: aciniform carbon (AC), composed of spheroidal carbon particles fused together in aggregates of colloidal dimensions; carbonaceous microgel (CM), in which spherolastic carbon particles are embedded in carbon or carbonaceous material; coke and char fragments; and carbon cenospheres 4.

TL;DR: A graphite-fibre reinforced structure capable of withstanding lighting strikes as mentioned in this paper comprises at least one ply of bonded graphite fibres with metal wire or metal coated filament woven therein in both the warp and fill directions to increase the capability of the laminate to withstanding lightning strike currents.

TL;DR: The mechanism of catalysis of the Boudouard (C-CO 2 ) reaction by the alkali-metal compounds appears to involve gaseous intermediates M( g ), CO( g ) and CO 2 ( g ) where M(g ) may be Li, K, Na, etc as mentioned in this paper.

TL;DR: The fracture toughness of three different glassy carbons heat treated at 1000, 2000 and 3000°C was measured at temperatures between 25 and 750°C as mentioned in this paper, showing that Young's elastic modulus varies inversely with measurement temperatures.

TL;DR: In this article, the porosity of carbonized wood was measured by scanning electron microscopy and measured by mercury porosimetry, and it was shown that porosity corresponds to the untreated wood modified by thinning down of cellular walls and by macroscopic contraction of the entire sample.

TL;DR: In this article, four kinds of coal, one weathered coal and one petroleum asphalt, were carbonized with 120 wt% NaOH, and the amount of hydrogen evolved increases enormously and the temperature of its evolution is lowered by 200-300°C.

TL;DR: In this paper, a general mechanism for the formation and deposition of coke is proposed, which helps collect tar droplets formed by gas-phase reactions, and such droplets decompose on the surface to produce coke that contains no metal.

TL;DR: A graphite intercalation compound of C x F(MgF 2 ) y was prepared under a fluorine atmosphere of 1 atm at temperatures of 20-350°C as mentioned in this paper.

TL;DR: In this article, an electrode substrate for a fuel cell having high porosity, a good mechanical strength and electroconductivity and a sharp distribution of pore radii is prepared by a process comprising mixing 30 to 50% by weight of carbon fiber.

TL;DR: In this paper, modified activated carbons were prepared by the partial oxidation of activated maghara coal with concentrated nitric acid and potassium permanganate, which fixes more oxygen on the carbon surface leading thus to the formation of carbon-oxygen complexes which act as primary centers for water adsorption.

TL;DR: In this paper, the rate of pyrolytic carbon reaction with oxygen has been measured over the temperature range 625-740°C and at pressures of oxygen from 6-100 torr.

TL;DR: In this article, three graphites, POCO AXF-5Q, Great Lakes H-440 and Stackpole 2020, were oxidized in air, CO2 and H2O, and the resulting samples examined for microstructural changes and loss of compressive strength.

TL;DR: In this paper, a graphitized carbon black and samples resulting from its oxidation in air at 798 K over different periods of time have been used as supports for platinum catalysts.

TL;DR: This paper found that the pore volume in the gasified char passed through a maximum at 40-50% burnoff, apparently due to mass loss from the exterior of the particles.

TL;DR: In this article, a structural model for carbon spherules is proposed based on the obtained dark-field images at various positions of the aperture on the 002 diffraction ring, which is supported by an electron microdiffraction study of various micro-areas of sections of the spherule.

TL;DR: In this article, the volume fraction of the graphitic particles distributed among microvoids was derived for coal under heat treatment in the range 500-800°C and the effective barrier height for tunneling between grains was obtained.

TL;DR: In this article, the authors used a Tian-Calvet microcalorimeter to measure the adsorption and heat of two microporous carbons, including charcoal cloth and graphitized carbon black.