Volatile Components of the Fruit of Pistacia Lentiscus

The volatile components from the fruit of the Pistacia lentiscus tree were analyzed by capillary gas chromatography (CGC) and CGC-mass spectrometry. The major components were the monoterpenes α-pinene, β-pinene, myrcene and limonene. Several sesquiterpenes, aliphatic esters, ketones, and phenolic compounds such as thymol and carvacrol were also identified.     

DEVELOPMENT OF FT-IR ATTENUATED TOTAL INTERNAL REFLECTION DICHROISM TECHNIQUES FOR STRUCTURAL CHARACTERIZATION OF POLYMER SURFACES

We describe our continuing effort to develop FT-IR attenuated total reflection (ATR) dichroism techniques for the characterization of polymer surface structure and molecular orientation. Following theoretical background, we review the two-dimensional and three-dimensional analyses work based on a specially designed internal reflection crystal and a specially built ATR-sample attachment. In the current development section, we describe briefly the intensity correction procedures used in variable angle studies and an attempt to design a hemispheric crystal attachment to eliminate problems encountered with face-cut reflection crystals.     

A unified theory for sharp dissolution front propagation inchemical dissolution of fluid-saturated porous rocks

This paper presents a unified theory to deal with when, why and how a sharp acidization dissolution front(ADF), which is represented by the porosity distribution curve, can take place in an acidization dissolution system composed of fluid-saturated porous rocks. The theory contains the following main points:(1) A reaction rate of infinity alone can lead to a sharp ADF of the Stefan-type in the acidization dissolution system. This sharp front is unstable when permeability in the downstream region is smaller than that in the upstream region.(2) For a finite reaction rate, when the acid dissolution capacity number approaches zero,the ADF can have a sharp profile of the Stefan-type either on a much smaller time scale or on a much larger time scale than the dissolution time scale. In the former case, the ADF may become unstable on a much larger time scale than the transport time scale, while in the latter case, it may become unstable if the growth rate of a small perturbation is greater than zero.(3) On the dissolution time scale, even if both the reaction rate is finite and the acid dissolution capacity number approaches zero, the profile of an ADF may not be sharp because it is in a transient state. In this case, not only can an ADF change its profile with time, but also its morphology can grow if the growth rate of a small perturbation is greater than zero. Due to the involvement of both the change rate and the growth rate of the ADF profile, it is necessary to conduct a transient linear stability analysis for determining whether or not a time-dependent ADF is stable in the acidization dissolution system.     

Application of Transmission Electron Microscopy to Radiation Damage in Ceramics

Ceramics are becoming increasingly important in many radiation environments. In addition to refractory fissionable fuels, electrical insulators will be needed for instrumentation in breeder reactor systems and will be widely applied in all fusion reactor concepts, including first-wall coatings, blanket gaps, injectors, divertors, magnet insulation, and windows. These applications require mechanically stable (and in some cases transparent) dielectric solids which must maintain electrical as well as mechanical integrity under severe radiation fields. Refractory ceramic materials of low atomic number will be increasingly useful in structural applications as well because they resist activation and contribute less objectionable sputter contaminants. Ceramic solids are also likely to be increasingly utilized as repository media for active nuclear wastes. The irradiation behavior of these nonmetallic materials is critical and at present poorly understood, but transmission electron microscopy is beginning to reveal significant similarities, as well as substantial differences, in their behavior as compared to that of better-characterized metallic solids.