Carbon dust

Dust Inhalation. During processing, fine carbon filaments (5—10 p.m in diameter) may break and be circulated in the air as a carbon dust that can be inhaled by operators. Studies (71) show the fibers are too large to represent a respiratory health risk however they often create discomfort, and a protective mask is recommended when working in areas where carbon fiber dust is present. 

EH21 Carbon dust health and safety precautions. 

ABSTRACT The locations, magnitudes, variations and mechanisms responsible for the atmospheric C02 sink are uncertain and under debate. Previous studies concentrated mainly on oceans, and soil and terrestrial vegetation as sinks. Here, we show that there is an important C02 sink in carbonate dissolution, the global water cycle and photosynthetic uptake of DIC by aquatic ecosystems. The sink constitutes up to 0.82 Pg C/a 0.24 Pg C/a is delivered to oceans via rivers and 0.22 Pg C/a by meteoric precipitation, 0.12 Pg C/a is returned to the atmosphere, and 0.23 Pg C/a is stored in the continental aquatic ecosystem. The net sink could be as much as 0.70 Pg C/a, may increase with intensification of the global water cycle, increase in C02 and carbonate dust in atmosphere, reforestation/afforestation, and with fertilization of aquatic ecosystems. Under the projection of global warming for the year 2100, it is estimated that this C02 sink may increase by 22%, or about 0.18 Pg c/a. 

The GWC sink for C02 may increase with intensification of the hydrologic cycle (Huntington 2006), including increase in MP DIC (increase in atmosphere pC02 and carbonate dust) and in RO DIC (due to reforestation Liu Zhao 2000). 

This sink, a negative climate feedback mechanism, may increase with the global-warming-intensified GWC, the increase in C02 and carbonate dust in atmosphere, reforestation/afforestation, and fertilization of the aquatic ecosystems. Using the global warming projection for the year 2100 by IPCC, it is estimated that the C02 sink by the GWC will increase by 22%, or 0.18 Pg c/a. 

Important, poorly-constrained variables in this carbon balance include temporal and spatial variations in precipitation and RO DIC, carbonate dust, and pedogenic carbonate and soil C02. In addition, ocean and lake response to river carbon input is not well known. Although marine and freshwater aquatic organisms can be fertilized by increases in N, P, Si, Fe, Zn and C02 (Cassar et al. 2004 Zondervan 2007), it is not clear how much of the... 

A comprehensive book series which encompasses the complete coverage of carbon materials and carbon-rich molecules from elemental carbon dust in the interstellar medium to the most specialized industrial applications of elemental carbon and its derivatives. A great emphasis is placed on the most advanced and promising applications ranging from electronics to medicinal chemistry. The aim is to offer the reader a book series which not only consists of self-sufficient reference works, but one which stimulates further research and enthusiasm. 

Improved design for control of dust, especially carbon dust generated by the carbon carrier. 

While some particulates, such as silica, produce well-recognized pathological effects, others, such as carbon dust, are more or less inert. However, there is no dust that does not produce some effect on the lungs when inhaled continually for perhaps years. Excessive concentrations of nuisance dusts in the air may cause reduction in visibility as well as uncomfortable deposits in the eyes, ears, and nasal passages, or even can cause... 

A study of 260 workers with 15 or more years of exposure to commercial talc dust (containing not only talc, but also tremolite, antho-phyllite, carbonate dusts, and a small amount of free silica) revealed a 40-fold greater than expected proportional mortality from cancer of the lungs and pleura. In addition, a major cause of death was cor pulmonale, a result of the pneumoconiosis the effects were likely due to the asbestos-form contaminants. The role of nonfibrous talc in these disease states could not be assessed. 

Kratschmer W, Fostiropoulos K, Huffman DR (1990) The infrared and ultraviolet absorption spectra of laboratory-produced carbon dust evidence for the presence of the Cgo molecule. Chem Phys Lett 170 167-170... 

As Maillard searched among the ash and molten material which had fallen through the grate, the academicians were confident that he would never see his diamonds again. When the airtight, glassy covering was broken away and the crucible opened, the tobacco pipe, the carbon dust, and the three diamonds were recovered intact. Hence it was evident that both heat and air were required for the destruction of the diamond (258, 260). 

Boln. containing Bodium chloride or nitrate in addition to the Bodium carbonate. H. Lowel also emphasized the importance of preventing access of air to the soln. from which the heptahvdrated carbonate is to be obtained—possibly because atm. dust contains some sodium decahydrated carbonate dust, which inoculates the solution with the wrong nuclei. H. Lowel also noted that there are dimorphic forms of the crystals—rhombohedral and rhombic—with different solubilities in water. 

The C stars are another case their average mass loss is slightly more than 10 times the value for solar-type stars with the same atmospheric parameters. This must indicate that C-star mass loss is dust-driven, for the driving efficiency of Carbon dust particles is about ten times the value for silicates (sedlmayr, private comm. 1987). 

The studies of carbon dust formation in C-rich stars have been recently done by Gail et al. (1984) and Gail and Sedlmayr (1985-, 1987). They found that the... 

The discovery of C60 by Kroto and coworkers (1985) was motivated in part by the interstellar dust problem. C60 would seem to be an ideal candidate, as it is spherical and graphite-like, it forms spontaneously in harsh environments with carbon dust, and is stable in intense radiation fields, a condition analogous to that found in the diffuse ISM (Kroto and Jura 1992). In fact, the observation of two DIBs at 957.7 and 963.2 nm are tentatively considered the first evidence of C60+ in interstellar dust (Foing and Ehrenfreund 1997). Moreover, a mixture of hydrides of C60 is shown to exhibit spectral features remarkably similar to those seen in the unidentified infrared emission (Stoldt et al. 2001). The UV absorption spectrum of synthetic C60H36 was also observed to possess abroad bump at 217.5 nm (Cataldo 2003). 

The Potential Role Played by the Fullerene-Like Structures of Interstellar Carbon Dust in the Formation of Molecular Hydrogen in Space... 

Fullerene-Like Structures on Carbon Dust of the Interstellar Medium Their Role in Molecular Hydrogen Formation... 

In other papers (Cataldo and Keheyan 2002 Cataldo and Pontier-Johnson 2002) we have tried to extend the results and the conclusions we have drawn in the field of the interaction between carbon black surfaces, activity and morphology, with radical and macroradicals also in the field of interstellar carbon dust. 

It has been proposed that fullerane C60I I 6 can be taken as a model of the interstellar hydrogenated carbon dust (Cataldo 2003a, b), but it is also possible that this molecule is a contributor to the interstellar light extinction curve together with other dust. 

In Fig. 8.2 we have shown that the UV photolysis of C60H36 causes a gradual shift of the absorption maximum from 217.5 nm to longer wavelengths going beyond 220 nm, exactly the same phenomenon observed previously (Colangeli et al. 1999) in the UV irradiation of hydrogenated carbon dust. 

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