Fibers roughness

Fabric Construction for Water RepeUency. Fabric constmction, including twist, ply, and coarseness of yams, affects the performance of water repeUents. Waterproof films can more easUy be formed on close weaves than on open-weave fabrics. Hydrophobic finishes, which make individual fibers repeUent without altering fabric porosity, are generaUy appUed to fabrics whose pores are smaU (37). The relation of rainwear fabric constmction to the performance of repeUents has been reviewed (38). Some reports indicate that fabric roughness reduces repeUency (28,37). Mechanical action on fabrics, even after treatment, can reduce repeUency if the action increases fiber roughness or exposes fibers that have Utfle repeUent treatment. 

Mackin, T.J., Warren, P.D. and Evans, A.G. (1992a). Effects of fiber roughness on interface sliding in composites. Acta Metall. Mater. 40, 1251-1257. 

Mackin, T.J., Yang, J. and Warren. P.D. (1992b). Influence of fiber roughness on the sliding behavior of sapphire fibers in TiAl and glass matrices. J. Am. Ceram. Soc. 75, 3358-3362. 

The distribution of ChAT-positive mossy fibers roughly corresponds to that of unipolar brush cells (see Section 3.6.3.), which raises the question whether these mossy fibers innervate these cells. Electron microscopic analysis of ChAT-immunoreactivity in the nodulus showed that a minority (10-20%) of ChAT-immunoreactive mossy fiber terminals synapse on brush cell profiles, and that a minority (10-30%) of the mossy fiber terminals contact unipolar brush cells that are immunoreactive for ChAT (Jaarsma, 1995c). 

Pure cellulose fiber (stripped of the lignin and hemicellulose contained in wood and other plant fibers) has been studied as an enhanced, high-aspect-ratio fiber alternative that costs less than glass fiber (roughly < 2/kg). This fiber has chemical resistance, heat resistance (up to 260°C), and it can be produced at nanometer-scale fiber widths to provide improved properties as a reinforcement in various modified forms. 

Steel, copper, and brass fiber may have a variety of aspect ratios, shape, ie, straight versus curved fibers and cross-sectional geometry, surface roughness, and chemical compositions. Fibers having tight specifications in terms of cleanliness, chemical composition, and aspect ratio ate necessary. The fibers are usually machined from larger metallic forms. 

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