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Although many studies have discussed visual acuity (VA), the childhood myopia epidemic has not been alleviated and requires further investigation. This study, therefore, investigates the differences in children’s VA among various family structures and the effects of visual health attitudes (VHA) and visual health behaviors (VHB) on VA. The children in low socioeconomic status (SES) families in Changhua County, Taiwan are the main research subjects. Using purposive sampling, the study conducts a questionnaire survey and a VA examination on low SES children, undergoing counseling at two social welfare organizations in Taiwan. The VA examination was conducted at the two social welfare organizations by an ophthalmologist from Tzu Chi Hospital, Taichung, between October 2016 and December 2016. 265 questionnaires were returned. Significantly, over 60% of the samples of low SES children were not living with their parents. Of these children, the highest proportion (35.8%) lived with their mothers; the second-highest (31.3%), lived with their grandparents; and the third highest (29.4%), lived with their fathers. 86.4% of the low SES children had poor (below 1.0) VA. The study, therefore, concludes that schools should focus on low SES students, and should focus on improving the VHA of the youngest students.

In recent years rapid advances have been made in materials technology, and the trend is set to continue with substantial investments being made by countries world-wide in materials development, processing and applications. The use of modern materials pervades all of industry and has a strong influence on its competitiveness. However, to convert these materials into competitive engineering products, the designer requires access to appropriate design methodologies that specify material property requirements. The need for reliable design data generated using validated and widely recognized measurement methods then becomes crucial. Furthermore, quantitative assessment of materials behaviour and performance is essential to achieve quality and reliability of products. Materials measurements have an important and widespread impact. This is illustrated in Fig. 9.1, which shows that the demand for the development of new or improved measurement methods originates from materials producers to enable them to provide reliable data that the market needs. There is also demand for data from users of materials so that products can be made and supplied to the market with a reliable expectation of performance.

A method has been evolved for bonding aluminous porcelain to pure platinum foil used for making porcelain crowns by the conventional 'tinner's joint' technique. It was found that good bonding was achieved when the platinum was coated with 0.2-2.0 mum of tin before firing on the porcelain. This paper describes experimental work for determining the optimum composition and thickness of the coating and the applicability of the technique to substrates other than platinum.

A treatment in hydrogen is described whereby the impurity content of electrolytic flake chromium has been reduced to oxygen

Results are presented to demonstrate the effect of bonding thin platinum foils to aluminous dental porcelain. The increased strength is explained in terms of a reduction in surface and subsurface pores in the porcelain brought about by improved wetting.

Reinforcement of aluminous dental porcelain crowns using a platinum alloy preformed coping technique

The strength of metal-ceramic bonds with base metals containing chromium. A preliminary report