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

No abstract available.
Solvents*

No abstract available.
Solvents*

No abstract available.
Solvents*

No abstract available.
Central Nervous System* ; Solvents*

No abstract available.
Neurotoxicity Syndromes* ; 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*

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

Conventional extraction of oil and azadirachtin, a botanical insecticide, from Azadirachta indica involves defatting the seeds and leaves using hexane followed by azadirachtin extraction with a polar solvent. In order to simplify the process while maintaining the yield we explored a binary extraction approach using Soxhlet extraction device and hexane and ethanol as non-polar and polar solvents at various ratios and extraction times. The highest oil and azadirachtin yields were obtained at 6 h extraction time using a 50:50 solvent mixture for both neem leaves (44.7 wt%, 720 mg(Aza)/kg(leaves)) and seeds (53.5 wt%, 1045 mg(Aza)/kg(seeds)), respectively.
Azadirachta ; Ethanol ; Limonins ; Solvents