Untreated fibers

For untreated carbon fibers, plotting of [—AG P/T against [T ] gives a straight line with slope [—A// p] and intercept [—AS P], as illustrated in Fig. 9, in the experimental temperature ranges of 35-75°C. As an example, Table 10 shows [—A// p] and [—AS P] determined by the plotting for between highly polar probes (in Table 7) and carbon fibers untreated and treated (by current density 1.4A/m2). 

Novel PVC foams are produced with wood fibers. Untreated and silane treated wood fibers were used. It was determined that by the selection of plasticizer level, foaming time, foaming temperature, and silane treatment of wood fiber, the foam of expected properties can be obtained. 

Figure 6.2 FTIR spectra of the treated and untreated coconut fibers untreated fibers (A), fibers treated with hot water at 80°C (B) fibers treated with aqueous NaOH 2% (w/v) (C) and fibers treated with the...

Figure 14.33 a) ATR spectra of single nylon carpet fiber untreated (top), treated (middle), and the result of spectral subtraction (bottom), b) Bicomponent fiber transmission spectrum (top), ATR spectrum of Nylon 6 sheath (middle), and difference spectrum of PET core (bottom).Reproduced with permission from Cho, L, et a ., "Single Fiber Analysis by Internal Reflection Infrared Microspectroscopy," iourna of Forensic Sciences 46 (2001), 1309-1314. Copyright 2001, ASTM International. 

Polycarbonate PC Various cellulose fibers, untreated or treated... 

Figure 1 Adhesion Strength v. Embedded length of an aramid Twaron 2200 fiber (untreated and Argon Plasma Treated) in a Pebax 7033 matrix...

Acetate and triacetate are essentially unaffected by dilute solutions of weak acids, but strong mineral acids cause serious degradation. The results of exposure of heat-treated and untreated triacetate taffeta fabrics to various chemical reagents have been reported (9). Acetate and triacetate fibers are not affected by the perchloroethylene dry-cleaning solutions normally used in the United States and Canada. Trichloroethylene, employed to a limited extent in the UK and Europe, softens triacetate. 

Fig. 7. Electron micrographs showiag (a) an untreated wool fiber and (b) a wool fiber treated with cblorine-Hercosett.

Fig. 2. Results of interfacial shear strength measurements of the same fiber/matrix systems using four different micro-mechanical tests during a round-robin program involving 12 different laboratories, (a) Results for untreated, unsized carbon fibers, (b) Results for carbon fibers with the standard level of surface treatment. Redrawn from ref. [13].

Using a method suggested by Saint-Flour and Papirer [100], Schultz and Lavielle obtained A// -values for the interaction of several vapors of differing donor numbers and acceptor numbers with various treated and untreated carbon fibers used in the preparation of carbon fiber-epoxy matrix composites. was expressed as ... 

Most of the above can be made into plastic films - primarily used for wrapping. Film properties vary widely from permeable for food to impermeable to preserve dryness. Paper, treated or untreated, has been used for many years as a covering film, but has low strength when wet and is difficult to make transparent. In the 1920s, the transparency of cellophane revolutionized wrap. It is regenerated cellulose, like viscose rayon, except it is extruded in sheet instead of fiber, unfortunately it is sensitive to water and humidity. 

Figure 12 Dependence of tensile strength and shear strength of PP-flax composites on fiber content and on surface treatment. (-) untreated flax (-) flax pretreated with hostaprime HC5.

Figure 7 SEM of (a) untreated and (b) alkali-treated coir fiber. (From Ref. 43.)...

SEM can also be used for the interface analysis of composites. Figures 16a and 16b show the SEM of PMPPIC-treated and untreated pineapple fiber-rein-forced LDPE composites. Strong adhesion between fiber and matrix is evident from Fig. 16a, whereas Fig. 16b indicates fiber pullout [78]. 

Figure 17 Raman spectra of a glass fiber/matrix interfaces. (A) styrene monomer (B) untreated E-glass fiber coated with polystyrene, (C) E-glass fiber treated with y-methacryloxy propyl trimethoxy silane.

Insulin is a powerful anabolic hormone but it is unlikely that insulin deficiency causes skeletal muscle atrophy by direct action on muscle fibers (as opposed to neurogenic atrophy) except in chronic untreated cases. There is however a close parallel between the catabolic states induced by glucocorticoid excess and by insulin deficiency. Moreover, impaired insulin action is implicated in other endocrine myopathies as a contributory cause of muscle wasting. Both acromegaly and thyrotoxicosis are associated with insulin resistance due to a postreceptor defect, and secondary hyperparathyroidism due to hypophosphatemia also gives rise to insulin insensitivity. 

William Henry Perkin, an 18-year-old working in the back room and outdoor shed of his London home, had discovered in black coal tar a beautiful purple dye that would change the world. For the first time in history, color could be democratized. William Henry Perkin and his purple, later known as mauve, rescued the poor and middle classes from their age-old austerity of hues. Natural dyes were expensive and, before Perkin s synthetic mauve, millions of poor people lived their lives in untreated drab and dingy fibers. Even for the middle class, pieces of brilliantly dyed cloth were treasures to be reused from garment to garment and from year to year. It was the schoolboy William Henry Perkin and his successors who would give the world the ample abundance of tints that only the rich had previously enjoyed. 

Our studies do not resolve the question of phytate vs fiber for the effect of wheat bran on dietary calcium bioavailability. Phytate level clearly affected apparent absorption of calcium in HS-II in the presence of an amount of the water insoluble fraction of dephytinized bran equivalent to 12 g of untreated bran and the phytate supplied as sodium phytate. An additional trial using untreated bran and the same amount of fiber as the water insoluble fraction with sodium phytate could resolve the question of fiber vs phytate. In HS-I, the balances were positive when a relatively large amount of bran, 36 g/day, was consumed. Calcium intakes were possibly higher than most men consume, but under the dietary conditions imposed for 15 days, the phytate and fiber of 36 g of bran did not express an adverse effect on calcium balance. 

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