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BACKGROUND Car drivers are generally exposed to direct sunlight during commuting hours, which may lead to irreversible skin damage; however, topographical analysis for different facial areas has not been reported. METHODS Facial areas were divided topographically into 11 areas based on esthetic units. We performed a preliminary study to identify the delivery pattern of solar energy on the face in the car during commuting time; subsequently, 15 drivers aged above 50 years were enrolled. Statistical evaluation was performed to investigate topographical differences between the left and right sides of the face and between sexes. RESULTS The left side of the face was different from the right side for L*, a*, and b* on the infraorbital area and L* and b* on the temporal area. Differences were found for L*, a*, or b* between sexes on the central and right face, but not on the left. The left side had more severe hyperpigmentation and wrinkles than the right on average. CONCLUSION The left facial area, especially the infraorbital and temporal areas, of Korean automobile commuters was vulnerable to sun damage. Therefore, automobile drivers should care about these areas while driving to prevent long-term effect from chronic solar damage.

Slow strain rate tensile tests were conducted on Grade-2 and Grade-12 titanium in simulated rock salt brines at about 83 C. The Grade-12 titanium studied showed superior mechanical properties compared to Grade-2 titanium, which were presumably due to smaller grain size and the presence of alloying elements and beta phase. Although neither metal showed obvious indications of stress corrosion cracking (SCC), the total elongation and reduction in area values showed some decrease. At the edge of the fracture surfaces in Grade-12 titanium specimens, a shear lip region was observed, but it was not related to the observed loss in ductility. Optical and scanning electron microscopy (SEM) results are discussed to elucidate the fracture mechanism.

The growth of platinum particles supported on flat alumina substrates, at 900–1100°C. has been studied for particles ranging in size from 35–120 nm. While the observed kinetics of growth were found to be inconsistant with classical (LSW) coarsening models, a reasonable interpretation of the results was obtained from an analysis based on nucleation-inhibited coarsening models. Comparison of the present results with those of earlier studies on smaller particles at lower temperatures has pointed out certain discrepancies which suggest possible directions for improvement of the kinetic models.

The friction and wear characteristics of types 304, 316 and Nitronic 60 stainless steel sliding against 440C have been compared. The studies involved a wide range of experimental techniques to characterize the wear specimens and the debris particles including optical metallography, microhardness tests, X-ray diffraction, scanning electron microscopy, microprobe analysis and transmission electron diffraction. These complementary techniques reveal that strain-induced ϵ and α' martensite phases are formed during sliding. The friction, wear and galling characteristics of these alloys depend on the stability of the austenite phase, the hardness of the α' phase and the hardness gradient.

The corrosion behavior of TiCode-12 (Ti-0.3 Mo-0.8 Ni) high level nuclear waste container alloy has been studied for a simulated WIPP brine at a temperature of 150°C or below. Crevice corrosion was identified as a potentially important failure mode for this material. Within a mechanical crevice, a thick oxide film was found and shown to be the rutile form of TiO2, with a trace of lower oxide also present. Acidic conditions were found to cause a breakdown of the passive oxide layer. Solution aeration and increased acidity accelerate the corrosion rate. In hydrogen embrittlement studies, it was found that hydrogen causes a significant decrease in the apparent stress intensity level in fracture mechanics samples. Hydride formation is thought to be responsible for crack initiation. Stress corrosion cracking under static loads was not observed. Attention has also been given to methods for extrapolating short term uniform corrosion rate data to extended times.