Electromagnetic interference shielding effectiveness of carbon materials

Electromagnetic interference shielding effectiveness of carbon materials

04 By-products 02lOO889 Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by native microflora and combinations of white-rot fungi in a coal-t...

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04 By-products 02lOO889 Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by native microflora and combinations of white-rot fungi in a coal-tar contaminated soil Canet, R. e/ al. Bioresource Technology, 2001, 76, (2), 113-l 17. Four white-rot fungi (P/rrmerochae(e chrJ~o.sporium IMI 232175, Pleurorus m~reutus from the University of Alberta Microfungus Collection IMI 341687, Coriolus versicolor IMI 210866 and Wye isolate #7) and all possible combinations of two or more of these fungi, were incubated in microcosms containing wheat straw and non-sterile coaltar contaminated soil to determine their potential to degrade polycyclic aromatic hydrocarbons (PAHs). Biotic and abiotic controls were prepared similarly and PAH concentrations remaining in each microcosm were determined after 8, 16 and 32 weeks by X-MS following extraction with dichloromethane. The greatest PAH losses were in the biotic control, compared to small or negligible differences in microcosms inoculated with one or more fungi. These results suggest that in the biotic control native microorganisms colonized the straw added as organic substrate and degraded PAH as an indirect consequence of their metabolism. By contrast, in other microcosms, colonization of straw by the natural microflora was inhibited because the straw was previously inoculated with fungi. Soil cultures prepared at the end of the experiment showed that though introduced fungi were still alive, they were unable to thrive and degrade PAH in such a highly contaminated soil and remained in a metabolically inactive form. 02lOO890 Curious aligned growth of carbon nanotubes under applied electric field Srivastava, A. er crl. Co&n, 2001, 39, (2), 201-206. In the present investigation the effect of external voltage (field) on the alignment of graphitic nanotubes as a result of applied electric field was investigated. The details of alignment effect embodying variation of applied electric field corresponding to applied voltage between 2 and 10 volts, the variation of length and diameter of the tubes have been studied. It has been found that both the degree of alignment and optimum length (~12 /Im), diameter (-60 nm) of the tubes are obtained for the applied electrical field corresponding to 6 volts. The applied electrical field for 6 volts has been estimated to be -1889 volts cm ‘. A feasible model for the effect of tube alignment due to the external electric field has been described and discussed. 02/00891 Development of binder pitches from coal extract and coal-tar pitch blends Stansberry, P.G. et crl. Lighr Me/. (Wurrentlrrle. PA, U. S.), 2001, 581585.

There is concern among US industrial pitch producers about domestic sourcing of quality binder pitches. Binder pitches are essential ingredients in the manufacture of carbon anodes. Although considerable work has focused on combining petroleum-derived materials with conventional coal-tar pitches, relatively little effort has been directed toward using solvent extracts from coal as feedstocks for blending. Researchers from West Virginia University and Koppers Industries, Inc. studied the effects of pitches developed by solvent extn. of coal. These coal-derived pitches were mixed with conventional coal-tar pitches in quantities sufficient to form laboratory-scale anodes. Formulations with a coal-tar pitch were used as controls. The binder pitches, green and baked anodes were then subjected to a battery of standard tests. The results of using solvent-extracted coal pitch on anode characteristics including thermal conditions, electrical resistivity, compressive strength, air permeability, bulk density, etc., are presented here. 02/00892 Development of petroleum enhanced coal tar pitch in Europe Turner, N.R. er crl. Light Met. ( Warrendde. PA, U. S.), 2001, 565-572. Petroleum enhanced coal tar pitches are proven products in the USA. In Europe, they are a preferred response to market analysis predictions for future pitch demand. This paper discusses laboratory-scale product development based on similar technology to Koppers in the USA, but based predominantly around more local materials for economic and strategic reasons. Successful developments have called for the identification of suitable petroleum raw materials and the methodology to combine petroleum and coal tar components to make homogeneous, performance products. Pitch properties and particularly bench scale anode information is the backbone of the paper. Traditional, standard pitch test results fail to do full justice to the enhanced binder materials. Bench-scale anode results indicate unanticipated, positive synergies between coal tar and petroleum derived molecules in an anode or other electrode environment where filler carbon is the largest constituent. 02/00893 Effect of carbon fiber grade on the electrical behavior of carbon fiber reinforced cement Wen, S. and Chung, D.D.L. Cm-bon. 2001, 39, (3) 369-373. Electrical conduction in cement reinforced by short carbon fibres below the percolation threshold is governed by carrier hopping across the fibre-matrix interface. The activation energy is decreased by

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increasing the fibre crystallinity, but is increased by using intercalated fibres. The carbon fibres contribute to hole conduction, which is further enhanced by intercalation, thereby decreasing the absolute thermoelectric power and the resistivity.

02lOO894 Effect of initiating additives on processing of coal tar and its fractions Kovalev, E.T. Koks Khim., 2001, 1, 19-23. (In Russian) Precise separation of coal tar by distillation is attained by eliminating a number of azeotropes by changing feedstock composition and using additives.

02/00895 Effects of pore structure and temperature on VOC adsorption on activated carbon Chiang, Y-C. ef nl. Corhon, 2001, 39, (4). 5233534. This research was undertaken to investigate the pore structure of three activated carbons and determine the temperature dependence of the adsorption of VOCs onto activated carbon. Three kinds of activated carbon made of different raw materials and four VOC species were chosen. The microporosity of activated carbon was assessed by the pore size distribution. The adsorption of VOCs showed that only C,,H,, exhibited the activated entry effect. The VOC adsorption capacity of peat-derived carbon was less dependent on temperature. A characteristic curve was observed for the peat-derived carbon. Benzene adsorption was the most preferable compared to other three VOCs because of higher heats of adsorption and lower entropy change, Results indicate physical adsorption played a critical role during adsorption processes in this study system.

02/00898 Effects of pre-carbonization on porosity development of activated carbons from rice straw Yun, C.H. e/ crl. Curhon, 2001, 39, (4), 5599567. To investigate the pre-carbonization effect on the porosity development in activated carbons, two types of activated carbons were manufactured from rice straws by the one-stage and two-stage processes, respectively. Despite of the differences in thermal history of the two processes, pore-drilling and pore-widening occurred simultaneously to increase the micro and mesopore volumes up to the activation temperature of SOO”C, above which pore-widening effect was however dominant, leading to the increase of mesopore volume. The micropore volume of the one-stage activated carbons (denoted SIAC) was considerably decreased, whereas that of the two-stage activated carbons (denoted SZAC) rarely changed with the increase of activation time. SZAC exhibited higher values of the BET surface area, micro and mesopore volumes than those of SIAC. This was attributed to the effect of the pre-carbonization that ensures the formation of relatively less defective carbonaceous structures.

02/00897 Electromagnetic interference shielding effectiveness of carbon materials Chung, D.D.L. Carbon. 2001, 39, (2), 2799285. Carbon materials for electromagnetic interference (EMI) shielding are reviewed. They include composite materials, colloidal graphite and flexible graphite. Carbon filaments of submicron diameter are effective for use in composite materials, especially after electroplating with nickel. Flexible graphite is attractive for EMI gaskets.

02/00898 Emerging technologies for third millennium on wood substitute and paint for coal ash Saxena, M. and Prabakar, J. F/y Ash Di.~po.wI Ufil.. In/ Conf.. Proc.. Znd. 2000, I, 2/26-2/31. Edited by Varma C.V.J. Considerable research and development activities carried out at Regional Research Laboratory, Bhopal, India, has led to the development of technologies for using coal fly ash in products such as bricks, roofing sheets, wood substitute products, etc., on laboratory and pilot scales. Polymer composites with blocks, up to 50% fly ash can be used as wood substitute products. The developed components/materials are stronger, more durable, resistant to corrosion, and above all cost effective as compared to the conventional material, i.e. wood. Coal ashbased paints offer improved resistance to corrosion and abrasion as compared to the conventional ones. By using the developed alternative building materials, prototype houses have been constructed for public awareness and adaptability and their wide scale utilization. Focus is made on the aspects related to the development of wood substitutes and paints using coal ash.

02lOO899 Fly ash management: vision for the new millennium Kumar, V. e/ ul. Fly Ash Di.~po.wl Uril.. Inr. Cmf PAM hl. l/l-li9. Edited by Varma C.V.J: Fuel and Energy Abstracts

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