Comparison of surface layer properties of composite resins by ESCA, SEM and X-ray cliffractometry
Abstract Hyperfine surface layer properties of three types of dental composite resins, highly-filled, conventional, and micro-filled resins, were studied using X-ray photoelectron spectroscopy (ESCA) by a combination of X-ray diffractometry and scanning electron microscopy (SEM). X-ray diffraction and SEM analysis showed clearly that each resin has different characteristics of SiO 2 particle size and distribution. ESCA depth resolution with argon ion etching indicated that in contrast to conventional and microfilled resins, carbon due to polymers of highly-filled resin decreases dramatically with increasing depth in the nanometer range of the resin-rich surface layer.
This paper analyzes the use of CBERS (China-Brazil Earth Resources Satellite) high resolution images to map urban limits of a small city in the Amazon Region of Brazil. The use of Sino-Brazilian satellite images to study small cities of the Brazilian Amazon Region is also discussed. A HCR image was used to classify the image of the study area into four classes: urban, forest, clouds, and shadows, by visual interpretation. This map was compared with another map produced with unsupervised classification. A confusion matrix was produced to evaluate the accuracy of unsupervised classification. Comparison between the reference map (visual interpretation) and the unsupervised classification map verified that 82.8% of the areas were classified correctly. This ability to recognize and delimitate small cities in Amazonia demonstrates the quality of the CBERS – HCR image.