• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.257-267
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• 2004

Our study investigated the association between solvent exposure and acquired color vision loss using the Lanthony D-15 desaturated panel in petrochemical industry. Since neurotoxic effects associated with chronic solvent exposure, subjects with more than 6 months of exposure were included. Exposure assesment was estimated mean, maximum and cumulative 8hr TWA from individual 8-hour sampling. Exposure status were classified into two groups, occupationally exposed group to solvent and a non-exposed group. The results showed that CCI was positively related for age. According to the results of qualitative analysis, there was no significant difference in the prevalence of specific Type of dyschromatopsia the two examined group. However, the prevalence showed a higher proportion of dyschromatopsia to solvent exposure. It was affect with acquired dyschromatopsia(Type II, III and Complex) in exposed worker group(5.9%,7.86%,14.99%, respectively) than in the nonexposed group(6.16%,7.55%,13.71%, respectively). After each variable was adjusted for age, alcohol and tobacco consumption, a relationship between acquired dyschromatopsia and exposure showed an increase in the Odds ratio as compared to the nonexposed group at only left. The results showed that acquired dyschromatopsia was positively related to age (p<0.001). The results showed that solvent exposure, although not significant, could cause the acquired dyschromatopsia and visual system can serve important information on early neurotoxic effects in generally. Therefore, we need to concerns about eye health in workers.

• KSBB Journal
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• v.6 no.3
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• pp.281-288
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• 1991

This research was carried to investigate the effects of several organic solvents on the enzymatic transphosphatidylation in emulsion and two-phase solvent systems. The solvents having a similar dielectric constant with diethylether were effective for the enzyme activity. Diethylether and butylacetate were the most effective solvents, when added 12-15%(v/v) and 10-40%(v/v), respectively, for the synthesis of phosphatidylglycerol, phosphatidylethyleneglycol and phosphatidylpropyleneglycol. In the emulsion system, the size of ovolecithin liposome was increased and the clearness of the phospholipid bilayer was reduced as increasing the diethylether concentration. In the twophase solvent system, the rapidest reaction was obtained when water-organic solvent ratio was close to 1. The ratio of aqueous phase. however, should be lowered to 37% to gain the sole product of transphosphatidy1ation, without phosphatidohydrolysis.

• Journal of Microbiology and Biotechnology
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• v.5 no.3
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• pp.177-180
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• 1995

In horseradish peroxidase-catalyzing polymerization of phenol under the water/dioxane solvent system, the optimal concentration of hydrogen peroxide was found to be 10 mmol/I. Feeding of hydrogen peroxide at its optimal concentration improved the polymerization performance by reducing reaction time and increasing molecular weights. Monomer conversions and the molecular weights of the enzymatically produced polymer were in the ranges of 83.1~94.2$%$ and 58000~68000, respectively.

• Journal of Pharmaceutical Investigation
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• v.10 no.3
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• pp.14-19
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• 1980

The dissociation constant of erythrosine in the mixed solvent systems of water-alcohols and water-acetone at various pH and in concentration media were determined by spectrophotometric method. Methanol, ethanol, and acetone were employed as solvents and studied the changes of pK values of erythrosine according to the kind and change of concentration of organic solvent which is mixed into water solution. The effect of organic solvent on pK is negligible at 40% while in the case of above 40% mixing, it is not negligible.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.123-131
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• 2006

This paper reports the apparatus and method for the safe treatment of pentachlorophenol(PCP)-treated ammunition box by solvent extraction. Experimental variables were chosen as the composition of solvents, types of substance(chips and sawdust), temperatures and sonication to obtain maximum PCP removal from wood samples of the dismantled ammunition box. Up to 99% of PCP in the wood chip was extracted within 2 hours at room temperature when using methanol as the solvent. The extraction volume ratio of methanol per dried sample was about 10. Type of samples, extraction temperature and sonification showed little effects on PCP extraction. Based on this study, a resource recycling system for the treatment of ammunition boxes was recommended.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.625-631
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• 1999

Ceramic tapes were fabricated by ultrasonically spraying slurries of monodispersed spherical and alumina powders. Effects of slurry compositions on tape forming were investigated. A relatively fast rate of solvent evaporation caused pores and cracks to be formed. A good chemical affinity between solvent and binder gave rise to binder separation resulting in inhomogeneous distribution of binder. Defect-free silica tapes with uniform distribution of particle packing and the binder were obtained from the solvent having a low chemical affinity and a slow evaporation rate and containing appropriate amounts of the binder and the plasticizer. Tape thickness could be controlled by adjusting solids loadings and slurry feed rates. It was possible to fabricate a tape in 15 $\mu\textrm{m}$ thickness from 7 vol% alumina slurry.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1493-1498
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• 2007

In this work, alkyl methacrylate-based microgels were synthesized by an experimental design method, and their sebum absorption characteristics were investigated. The results of fractional factorial experimentation indicated that the cross-linking agent content, solvent content, and stirring speed were the main parameters in the synthesis of the microgels. The suitable synthesis conditions were determined by the response surface design method. Through a study of the monomer and solvent effects, it was confirmed that the microgel shows the highest sebum absorption ratio when t-butyl methacrylate is used as a monomer or when acetone is used as a solvent. The optimal microgel synthesis conditions for cosmetic application were determined, and the resulting microgel had a mean particle size of 4.7 μm and a sebum absorption ratio of 435%.

• Journal of the Korean Chemical Society
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• v.63 no.4
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• pp.233-236
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• 2019

In this study, the solvolysis of cyclohexanesulfonyl chloride (1) was studied by kinetics in ethanol-water, methanol-water, acetone-water, and 2,2,2-trifluoroethanol (TFE)-water binary solvent systems. The rate constants were applied to the extended Grunwald-Winstein equation, to obtain the values of m = 0.41 and l = 0.81. These values suggested $S_N2$ mechanism in which bond formation is more important than bond breaking in the transition state (TS). Relatively small activation enthalpy values (11.6 to $14.8kcal{\cdot}mol^{-1}$), the large negative activation entropy values (-29.7 to $-38.7cal{\cdot}mol^{-1}{\cdot}K^{-1}$) and the solvent kinetic isotope effects (SKIE, 2.29, 2.30), the solvolyses of the cyclohexanesulfonyl chloride (1) proceeds via the $S_N2$ mechanism.

• Journal of Sensor Science and Technology
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• v.26 no.2
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• pp.96-100
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• 2017

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively studied as the active material in ammonia gas sensor because of its fast response time, high conductivity and environmental stability. It is well known that a post annealing process for organic devices based on PEDOT:PSS significantly increases the device performance. In this study, we propose the solvent annealing of PEDOT:PSS and investigated its effects. As a results, post solvent annealing on PEDOT:PSS lead to the surface chemical and physical properties change. These changes result in improved conductivity of the PEDOT:PSS. In additional, ammonia sensitivity of solvent annealed PEDOT:PSS become higher than pristine polymer film. The enhancement is mainly caused by the depletion of gas barrier PSS and structural re-forming PEDOT networks. We believe that the post solvent annealing is a promising method to achieve highly sensitivity PEDOT:PSS films for applications in efficient, low-cost and flexible ammonia gas sensor.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.3-8
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• 1986

The investigation of the effect of solvent structure on the first-order solvolysis of cis-$[Co(en)_2ClNO_2]^+$ion has been extended to water + co-solvent mixtures where the co-solvents are glycerol, ethylene glycol, isopropyl alcohol and t-butyl alcohol. Rates of solvolysis have been evaluated by spectrophotometric method at temperature 25∼30$^{\circ}$C. The polarity of solvent has influence on the variation of rate constant. The non-linear plot of the rate constant in log scale versus $\frac{D-1}{2D+1}$ implies that change in solvent structure with composition plays an important role in determining the variation of rate constant. The linearity of the plot of the rate constant in log scale versus the Grundwald-Winstein Y factor confirms that the solvolysis is an Id-type process with considerable extension of the metal chloride bond in the transition state. In the Kivinen equation the slope of the plot of log k versus $log(H_2O)$ suggests that the solvolysis is also an Id-type process. The application of free energy cycle shows that the effect of solvent structure is greater in the transition state than in the initial state.