No abstract available.
Solvents*

No abstract available.
Solvents*

No abstract available.
Solvents*

This study was conducted in order to clarify the factors affecting the number of utilization to health center for the shipyard workers who have been work in exposed environment to solvent. At first the tendencies of the number of utilization to health center in accordance with cumulative exposure(CE), lifetime weighted average exposure(LWAE), one's place of duty, work contents, states of using safety apparatus, the degree of the knowledge on handling solvents, exposure year. 1) The increase in the cumulative exposure(CE) was significantly higher in the number of utilization to health center. The group with longer exposure year showed significantly higher number of utilization to health center(p<0.01). Considering the work contents such as power blasting, spray, mixing and touch-up, the group of touch-up showed higher number of utilization to health center and this difference was statistically significant(p<0.001). Those who were not using the safety apparatus, showed higher number of utilization to health center, which was statistically significant(p<0.05). The degree of the knowledge on handling the solvent had no relation with using health center. 2) The results conducted from this study by multiple regression analysis in clarifying the factors affecting the number of utilization to health center, CE, exposure year and using safety apparatus was significant factor in utilization of health center.
Solvents

1. This investigation has removed definitely our apprehension that gasoline and naphtha, which are potential hazards in the three convas-rubber shoe factories, might be a real danger. The highest concentration of gasoline vapor found was only 460 p.p.m, which is lower than the maximum allowable concentration-500 p.p.m2. The statistical analysis of the blood pressure by age group did not show any significant difference between the exposed and unexposed groups of workers, indicating no appreciable effects of the gasoline and naphtha vapors3. The symptoms found among the workers were also analyzed and were found to be not due to the solvent. There were, however, some individuals who showed more susceptibility or sensitiveness to gasoline vapor; and these individuals should be transferred to other departments of the factories free from such vapor4. The psychrometric findings showed that there is need of rearrangement of electric fans in one factory to promote air circulation, and opening of more windows in the two others to correct deficient temperature. Regarding Kata value (cooling power of air) and wind velocity in the different sections of the factories, the following standards are recommended: wind velocity of 50-100 feet per minute where there is no gasoline vapor; not less than 200 feet per minute where gasoline vapor is present; and Kata cooling power of not less than five where the temperature is more than 85 degrees F5. For preventive measures, it is recommended that exhaoust ventilation systems be provided in the vicinity of the canvas-rubber shoe making tables and in the rubber cement mixers. The factories should also be inspected at least twice a year to determine the concentration of solvent vapor in the different working areas. (Conclusions and recommendations)
Solvents

No abstract available.
Central Nervous System* ; Solvents*

For the study of the applicability of predictive equation of subjective symptoms of workers using organic solvents, 67 male workers using organic solvents were selected. The predictive equation was quotated from previous Cheon's study. All the datas of necessary variables were gained. The predictive values and observed values were compared. The results were summarized as below; 1. The difference between predictive values and observed values were characteristically large. The coefficient of determination between the two values was 0.0024. 2. The R2 value of multiple stepwise regression equation derived from present study was 0.2827.
Humans ; Male ; Solvents*

No abstract available.
Neurotoxicity Syndromes* ; Solvents*

The study examined some factors (solvent, catalysis, temperature) affecting to fluoroalkyl ether subsynthesis effects of dihydroartemisinin. TF-DHA and PF-DHA, two fluoroalkylether derivatives of dihydroartermisinin was prepared by treatment of dihydroartermisin with appropriate fluoroalcohol in the presence of boron trifluoride etherate. The dicloromethan solvent is most efficient option for TF-DHA's preparation
Artemisinins ; Therapeutics ; Solvents

Metal brackets were recycled by variable methods for economic reason. Such recycling methods had a great effect on bracket slot width and bonding strength. Therefore, the recycling methods that don't change the properties of original bracket were suggested. In this study, debonded brackets were recycled with 30 kinds of solvents and bracket surfaces were examined by S.E.M. (Super IlIA, lSI International Scientific Instruments, Japan) and Stero Microscope (Sz-Tr, Olympus Tokyo, Japan) methods. The following results were obtained. 1. Thermosetting resin adhesives (eq. Monolok(R), Concise(R)) were swelled most in sulfuric acid (assays 95%) and slightly in alcohol groups. 2. The solvent was exchanged every 24 hours during the brackets were recycled with sulfuric acid (assays 95%). As the passage of time, the adhesives were removed more clearly, and after 72 hours adhesives were nearly detached from bracket base. 3. Chemical recycled metal bracket surface showed no irregular structure by S.E.M. method.
Adhesives ; Recycling* ; Solvents ; Sulfur