Fiber dimension

Fiber Dimensions. Except for the seed-hair fibers, the vegetable fibers of bast or leaf origins are multiceUed (Fig. 1) and are used as strands ... 

Mechanical Considerations and Fiber Dimensions. The hoUow fiber is self-supporting, and is actuaUy a thick waU cylinder. The ratio... 

This value is taken into account when planning hoUow-fiber dimensions. A partial account of these considerations can be found in References 6 and 7. In practical appUcations, ie, reverse osmosis, membrane compaction with time is experimentally derived as a function of the polymeric material at given temperatures and pressures (8). 

Fiber dimensions have been studied for hemodialysis. When blood is circulated through the fiber lumen (m vivo), a significant reduction in apparent blood viscosity may occur if the flow-path diameter is below 100 p.m (11). Therefore, current dialy2ers use fibers with internal diameters of 180—250 p.m to obtain the maximum surface area within a safe range (see Dialysis). The relationship between the fiber cross section and the blood cells is shown in Figure 5. In many industrial appUcations, where the bore fluid is dialy2ed under elevated pressure (>200 kPa or 2 atm), fibers may burst at points of imperfection. Failure of this nature is especially likely for asymmetric fibers that display a large number of macro voids within the walls. 

The blends were prepared with two take-up speeds to achieve morphologies with different LCP fiber dimensions. The lower speed (L), leading to a draw ratio of 1 1, represents the normal blending procedure, which was what we used in our previous work [44]. The higher speed (H) resulting in a draw ratio of 6 1 was applied to form long highly oriented LCP fibers. The draw ratio for each strand was determined as the ratio between the die and strand cross-sections (Sq/Ss). 

Blends of polypropylene (PP) and liquid crystalline polymer (LCP) processed without melting the LCP were compared with conventional melt processed blends. In a first stage, PP was blended with 20 wt% of LCP in a twin-screw extruder with the take-up speed varied to achieve blends with different LCP fiber dimensions. In the second stage, these blends were processed both below and above the Tm of the LCP by extrusion and injection molding. 

Pooley, F. D., and N. Clark (1979). Fiber dimensions and aspect ratio of crocidolite, chrysotile and amosite particles detected in lung tissue. Ann. N.Y. Acad. 330 711-716. 

Stanton, M. F., M. Layard, A. Tegeris, E. Miller, M. May, and E. Kent (1977). Carcinogenicity of fibrous glass pleural response in the rat in relation to fiber dimension. J. Natl. Cancer Inst. 58 587—603. 

Hesterberg TW, Barrett JC. 1984. Dependence of asbestos- and mineral dust-induced transformation of mammalian cells in culture on fiber dimension. Cancer Res 44 2170-2180. 

Important determinants of toxicity include exposure concentration, exposure duration and frequency, and fiber dimensions and durability. 

What are the molecular events involved in the development of asbestos-induced respiratory and pleural effects and how are they influenced by fiber dimensions and mineral type Identification of the molecular and cellular events of asbestos-induced disease has been the subject of extensive research within the past two decades (see Mechanisms of Asbestos Toxicity Overview section). However, much remains unknown, and the precise steps in pathogenic pathways are not frilly established. 

Important determinations of asbestos toxicity include exposure concentration, duration, fiber dimensions, and fiber durability. There is animal and human evidence that long fibers are retained in the lungs for longer periods than short fibers and that amphibole fibers, such as tremolite asbestos, are retained longer than chrysotile fibers. Short and long fibers may contribute to the pathogenesis of inflammation, fibrosis, and cancer in humans, but their relative importance is uncertain. 

He LM et al (2010) Synergistic effects of electrospun PLLA fiber dimension and pattern on neonatal mouse cerebellum C17.2 stem cells. Acta Biomater 6(8) 2960-2969... 

Fiber Dimensions. As is apparent from Eq. (20.6-41). friction loss in the fiber bore can be significant if the bore themeter is smell and the permeant flow cme (m,) is high. The significance of permeant pressure beildup is shown in Fig. 20,6-9. Permeability data for polysulfone are used in the calculation. Except for fiber ID, all the other operating variables are the same for ihe four cases. In Fig. 20.6-9n. the "driving"... 

Hollow-fiber separator comp os it ion-dependent permeab ility feed composition feed pressure fiber dimensions multistage pressure drop Horizontal decanters HTU... 

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