Impact Of Thermal Processing Research Articles

Thermoplastic elastomer gels. I. Effects of composition and processing on morphology and gel behavior

Thermoplastic elastomer gels (TPEGs) composed of a poly[styrene-b-(ethylene-co-butylene)-b-styrene] triblock copolymer and a low-volatility, midblock-compatible mineral oil have been investigated at different oil concentrations to ascertain the effect of composition on TPEG morphology and mechanical properties. The impact of thermal processing is also examined by comparing gels thermally quenched to 0°C or slowly cooled to ambient temperature. Transmission electron micrographs reveal that gels with 70 to 90 wt % oil exhibit styrenic micelles measuring ca. 24 nm in diameter. Variation in composition or cooling rate does not have any perceivable effect on micelle size or shape, whereas the rate at which the gels are cooled influences the extent of microstructural order and the time to rupture (tR) at constant strain. Dynamic rheological testing confirms the presence of a physically crosslinked network at TPEG compositions ranging from 70 to 90 wt % oil, independent of cooling rate. Results presented here suggest that the dynamic elastic shear modulus (G′) scales as tαR where α varies from 0.41 to 0.59, depending on cooling rate. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2379–2391, 1998

Folate in goat milk products with reference to other vitamins and minerals: A review

As with cow milk, if goat milk is to be used as the sole source of nutrition during early infancy it needs to be modified. These modifications must include dilution in order to reduce renal solute load and the addition of sugar, vitamins and minerals to make the formulation more like human milk and more nutritionally complete. Infants fed exclusively goat milk are at risk of developing megaloblastic anemia unless the goat milk is fortified with folic acid or the infant is provided with an oral folic acid supplement. In addition to the absolute difference in folate concentration between goat and human milk, the impact of thermal processing and species differences in milk folate bioavailability should be considered in fortification of milk products. More research is needed to elucidate the impact of different feeding regimes (e.g., iron and folate content of diets) on milk folate content. Postweaning, there is little doubt that goat milk is an excellent source of nutrition for the human when used as part of a nutritionally well-balanced diet.

Diffusion Behavior of B-, As- and Sb-Dopants in Thin Epitaxial Layers

ABSTRACTAdvanced CVD- and MBE-epitaxy allows processing of very thin epitaxial layers with extremely steep dopant gradients. As steep dopant profiles are very sensitive to temperature treatments, the impact of thermal processing from 800°C to 1000°C on the dopant redistribution in epitaxial layers was investigated.