Carbon Pad

The spectra depicted in Figure 15.3 have all been obtained by placing small quantities of the pertinent substances on a black carbon pad. The question immediately arises whether or not the same results can be obtained by utilizing different substrates. Figure 15.4 displays differential reflection spectra of TNT on leather, fabric, latex glove, aluminum alloy, and cardboard. As can be seen, the spectra are essentially alike, demonstrating that the kind of substrate is immaterial for TNT detection by DR. 

FIGURE 11.26 Novel carbon pad with fabricated electrocells for ECMP (from Ref 33). 

Figure 23.53 A selection of AP carbon-carbon clutches, (a) A ring type carbon-carbon clutch showing carbon stack, adaptor ring and cover that houses the diaphragm spring drive hub and main pressure plate, (b) Cushion flywheel, 140 mm diameter twin plate carbon-carbon clutch predominantly used in Touring Car formulas, (c) Formula 1 brakes and clutch, 4 and 6 piston brake calipers 280 mm diameter carbon disk with carbon-carbon pads 115 mm diameter triple plate push type carbon-carbon clutch, (d) 97 mm FI clutch, depicts the latest carbon-carbon clutch being used in FI racing. It has a push type design and is a triple plate clutch. Source Courtesy of AP Racing.

The transfer of special waste is regulated by a system of consignment notes to ensure that waste can be tracked at every stage of its movement, from the time it is originally transferred to the point where it is finally disposed of at a suitably licensed site. The system requires the use of a preprinted five-copy self-carboning pad of consignment notes with each of the five sheets coloured differently. The use of the sheets is as follows ... 

A model permit system is shown in Table 7.1, containing a suite of permits comprising a general all-purpose format and special applications. The table shows the sequence of actions involved in a permit-to-work system. Where there is expected to be significant use of any or all the permits, it is recommended that a self-carbon pad of each is printed, in order to allow easy sequential numbering and filing of record copies. 

Add 1 ml. of the alcohol-free ether to 0-1-0-15 g. of finely-powdered anhydrous zinc chloride and 0 5 g. of pure 3 5-dinitrobenzoyl chloride (Section 111,27,1) contained in a test-tube attach a small water condenser and reflux gently for 1 hour. Treat the reaction product with 10 ml. of 1-5N sodium carbonate solution, heat and stir the mixture for 1 minute upon a boiling water bath, allow to cool, and filter at the pump. Wash the precipitate with 5 ml. of 1 5N sodium carbonate solution and twice with 6 ml. of ether. Dry on a porous tile or upon a pad of filter paper. Transfer the crude ester to a test-tube and boil it with 10 ml. of chloroform or carbon tetrachloride filter the hot solution, if necessary. If the ester does not separate on cooling, evaporate to dryness on a water bath, and recrystallise the residue from 2-3 ml. of either of the above solvents. Determine the melting point of the resulting 3 5 dinitro benzoate (Section 111,27). 

Developments in the carbonizing of fabric (77) have been aimed at reducing the volume of acid used (78,79), in order to reduce energy in drying and save neutralization costs, and at the use of generally available textile processing equipment, eg, the padmangle, for appHcation of the acid in a pad-dry-bake process (80). 

Storage. Purified and dry aHyl chloride can be safely stored in carbon steel vessels. Use of lined vessels is recommended if slight discoloration or trace presence of metals is undesirable for its intended use. In any event, the presence of air should be avoided for safety (flammabHity) reasons through the use of an inert gas pad. Tank vents should be treated, eg, by incineration, prior to venting to the atmosphere. Some commercial producers intentionaHy add about 0.1% propylene oxide as a stabilizer to prevent discoloration however, this is usuaHy unnecessary if product purity is sufficiently high. 

These problems can be dealt with by usiag artificial test cloths impregnated with various approximations of natural soils such as vacuum cleaner dust, dirt from air conditioner filters, clays, carbon black, fatty acids, dirty motor oil, and artificial sebum, either alone or ia combination (37,94—98). The soils are appHed by sprayiag, immersion, or padding. If the soils are carefully appHed, reproducible results can be obtained. Soil test cloths can be of great help ia detergency studies, when used with an understanding of their limitations. 

Composites fabricated with the smaller floating catalyst fiber are most likely to be used for applications where near-isotropic orientation is favored. Such isotropic properties would be acceptable in carbon/carbon composites for pistons, brake pads, and heat sink applications, and the low cost of fiber synthesis could permit these price-sensitive apphcations to be developed economically. A random orientation of fibers will give a balance of thermal properties in all axes, which can be important in brake and electronic heat sink applications. 

There are several types of mesh available, and these are identified by mesh thickness, density, wire diameter and weave pattern. Table 4-9 identifies most of the commercial material now available. The knitted pads are available in any material that can be formed into the necessary weaves, this includes stainless steels, monel, nickel, copper, aluminum, carbon steel, tantalum, Hastelloy, Saran, polyethylene, fluoropolymer, and glass multi-filament. 

The partially hydrolysed material was fractionated by size exclusion chromatography on a Bio Gel PIO (Bio Rad) column (2,6 x 90 cm) and eluted with 50 mM ammonium hydrogen carbonate at 20 ml/h and fractions of 3.2 ml each were collected. Fractions 45-70 were pooled and subjected to HPAEC-PAD for further separation. 

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