Shape fiber

The open hoUow fiber shape shown ia Figure 13 is made by a unique process requiring bicomponent yam technology (145). A yam is spun with a water-soluble copolyester core and nylon sheath where the core is dissolved out with an alkaH treatment ia fabric dyeiag. 

In contrast to chrysotile fibers, the atomic crystal stmcture of amphiboles does not inherentiy lead to fiber formation. The formation of asbestiform amphiboles must result from multiple nucleation and specific growth conditions. Also, whereas the difference between asbestiform and massive amphibole minerals is obvious on the macroscopic scale, the crystalline stmctures of the two varieties do not exhibit substantial differences. Nonfibrous amphiboles also exhibit preferential cleavage directions, yielding fiber-shaped fragments. 

The principle of a three-phase membrane extraction is illustrated in Figure 1.28. An organic solvent is immobilized in the pores of a porous polymeric support consisting of a flat filter disc or a hollow fiber-shaped material. This supported liquid membrane (SLM) is formed by treating the support material with an organic solvent that diffuses into its pores. The SLM separates an aqueous... 

Harris, R. L., Jr., and V. Timbrell (1977). The influence of fiber shape in lung deposition mathematical estimates, pp. 75-89. In Walter, W. H., ed. Inhaled Particles, Vol. IV, Part 1. Pergamon Press, Oxford. 

The second factor that affects performance in discontinuously reinforced FMCs is fiber length. This has an effect primarily on the ease with which the composite can be manufactured. Very long fibers can create difficulties with methods used to create discontinuously reinforced FMCs and can result in nonuniform mechanical properties. The third factor is also related to fiber geometry, namely, the fiber shape. Recall that the... 

PMS required UV curing for 1.5 h prior to pyrolysis in order to retain the fiber shape. Additionally, the use of metallocene catalysts renders PMS highly oxygen-sensitive and pyrophoric. 

It has been shown that small changes in the pre-expansion pressure at constant pre-expansion temperature and solute concentration do not affect the precipitate characteristics (Mohamed et al., 1989a). On the other hand, for changes in the pre-expansion pressure of 69 bar, the observed precipitate morphology varied from micron-size spherical to fiber shape (Lele and Shine, 1994). However, Domingo et al. (1997) reported that changes in the pre-expansion pressure of their system proved to be inconclusive. Interestingly, Ksibi (1995) noticed a decrease in particle size with an increase in the pre-expansion pressure of about 41 bar. This was accompanied by a narrower particle size distribution. 

Uniform mixing of powdered materials occurs if they have similar particle size distributions and particle shapes. Spherical particles mix least well while plate and fiber shapes also do not mix well because they tend to clump. The more cohesive the material, the more difficult it is to mix that material with other materials. Similarly, cohesiveness between drug and excipient or among excipients may hinder the... 

On the observe side of the breastplate are fiber shapes that are smooth and separate and exhibit some crimp (Figure 8). Some evidence of longitudinal striations on the formations is present inconsistency in size is found. They twist around each other while maintaining structural integrity. If the fiber shapes are bast, they have been subjected to some processing to separate them from their bundles. On the other hand, if the fibers occurred in the environment in somewhat the same structure as the pseudomorphs, that is, separate and individual, they would therefore be from a fiber class other than bast. 

The central shaft of the Mound C earspool is wrapped with fiber pseudomorphs. The fiber shape has a flat, twisting, ribbonlike ap-... 

Membranes that arc catalytically active or impregnated with catalyst do not suffer from any potential catalyst loss or attrition as much as other membrane reactor configurations. This and the above advantage have the implication that the former requires a lower catalyst concentration per unit volume than the latter. It should be mentioned that the catalyst concentration per unit volume can be further increased by selecting a high "packing density" (surface area per unit volume) membrane element such as a honeycomb monolith or hollow fiber shape. 

The discussion concerning polycondensation polymers so far has been restricted to systems using only bifunctional monomers. By doing this we have seen that high purity, very close to equimolar (stoichiometric) proportions of functional groups, and nearly complete reactions are needed to obtain useful high molecular weight material. The linear products from these types of polymerizations may be more or less readily melted, or dissolved in a solvent for production of useful fibers, shapes, etc., from the crude polymer resins. 

Owing to different types of connections of the colloidal particles via =Si—O Si= bonds, the shape of the aggregated big Si02 particles could have a chain, rod, or fiber shape. These big Si02 colloidal particles could further cross-link to form a network structure in three-dimensional space containing a large amount of solution. 

Number of Fibers Fiber Shape Fiber Length Fiber Width... 

Activated carbon fibers (ACFs) are porous carbons with a fiber shape and a well-defined porous structure that can be prepared with a high adsorption capacity. Although the ACFs are very promising materials, they have not still a market as important as the activated carbons (ACs) due to their difference in production costs. The main characteristics and advantages of the ACFs are as follows [1-3]. 

Once the precursor (i.e., pitch, polymer) is transformed into a fiber shape by a suitable spinning process and is carbonized after a proper stabilization stage, the activation of the resulting CF is needed to increase its adsorption capacity. 

In summary, as it happens with granular and powder carbons, a proper selection of the CF and the activation method and experimental conditions permits the preparation of ACFs with a tailored pore size distribution, with the additional advantage of their fiber shape and small diameters that allow faster mass transfer rates when compared with conventional ACs. 

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