This study investigated dental students' smoking behavior and their attitudes, in order to provide programs to patients for giving up smoking. A questionnaire survey was conducted on dental students from November 2003 to February 2004. The subjects were 69 third-grade and 80 fifth-grade students of Tokyo Medical and Dental University. The following results were obtained. (1) The smoking rate of dental students was 19.4% (Male: 31.3%, Female: 5.8%). (2) About forty-three percent of the students had started smoking before entering the university. However, most of the students who smoked had started after entering the university. The smoking rate and number of cigarettes smoked of fifth-grade students were significantly higher than those of third-grade students. (3) Dental students recognized the health risks of smoking more than the general public, especially concerning periodontal disease. (4) Only 5.4% of students answered that they would actively provide advice and instructions about the health hazards of tobacco to patients who smoked. (5) The rate of students who answered that they had enough knowledge to conduct smoking cessation programs for patients was 21.5%. (6) Students who smoked showed positive attitudes towards dentists' smoking behaviors and had passive attitudes towards smoking cessation programs conducted by dentists. These results show it is necessary to conduct smoking cessation programs soon after entering university and to provide more lectures on tobacco and health issues as well as practical training programs about giving up smoking in the dental education curriculum.
The present study aimed to investigate the effects of SiO2 polymorphism on the mechanical properties of feldspathic porcelains. Seven kinds of experimental feldspathic porcelains were prepared using chemical reagents; three types of low-fusing feldspathic glasses and four types of two-phase porcelains by adding 10 or 20 mass% of fused silica (T-F) or cristobalite (T-C). Flexural strength and fracture toughness of these porcelains were evaluated. Flexural strengths of two-phase porcelains did not show any significant increase when compared with those of single-phase glasses. On the other hand, fracture toughnesses of porcelains with cristobalite showed a significant increase when compared with those of single-phase glasses. Circumferential cracks were observed in the porcelains with cristobalite. These results suggested that cristobalite could strengthen fracture toughness of feldspathic porcelains, but not flexural strength.
On the flaming combustion of highly densified cypress cylindrical briquette of which diameter/length ratio is 1/2 in the high temperature air, it was reported that the flaming combustion duration is proportional to the product of the inverse square of the specific surface area and the briquette density. However, the influence of biomass raw material on the combustion behavior is not clarified yet. To utilize various biomass as raw material of briquette fuel, the knowledge on this should be obtained. The objective of the present study is to confirm the influence of biomass raw material on the flaming combustion behavior, especially, the flaming combustion duration. Cypress, bamboo, rice husk and paper are used as raw material of the briquette. From the results of the thermogravimetric analysis and the estimation of lignin content in the biomass samples, it was observed that the activation energy decreases with increasing the lignin content. From the results of combustion experiments, it was found that the flaming combustion durations for each biomass raw material are proportional to the product of the inverse square of the specific surface area and the briquette density. It is suggested that these proportional constants have the correlation with the mass percentage of the cellulose in the biomass.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.