• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.237-245
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• 2011

Purpose: The present study was conducted to investigate whether certain repeated physical and/or chemical stimuli added on ophthalmic lenses might induce any changes of the functions of lens coatings. Methods: The changes in lens surface, light transmittance, foggy duration, durability of ophthalmic lenses were determined after the application of tearing-off with tape, rubbing with acetone, soaking in acetone or distilled water of ophthalmic lens (CR-39 material) as physical and/or chemical stimuli. Results: The change of ophthalmic lens surface was detected after soaking in acetone for longer than 30 minutes by observing the lens surface to figure out the functional change of hard coating. The ophthalmic lens soaked in distilled water for 180 minutes showed little functional change of anti-reflection coating as 1% by measuring light transmittance of lens. However, the function of anti-reflection coating was almost disappeared after the ophthalmic lens was soaked in acetone for 60 minutes. The foggy duration of ophthalmic lens soaked in acetone was increased by estimating foggy duration of lens. The lens coating was shown to be defected when the pre-damaged ophthalmic lenses were torn off with tape, rubbed with acetone and soaked in distilled water or acetone by observing pre-damaged lens surface to evaluate its durability. Conclusions: The careful management during ophthalmic lens dispensing or usual eyeglass wearing is needed since the change in ophthalmic lens coatings was shown by repeated physical and/or chemical stimuli.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1087-1092
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• 2000

Traditional food soybean curd was prepared using the fresh fruit juice of Schizandra chinensis RUPRECHT(Omija) and Prunus mume(maesil), and investigated the optimal preparative conditions(water addition ratio, heating time of mashed soybean and fresh fruit juice concentration), physical properties, sensory evaluation and shelf-life. Soybean curd coagulated with 0.9% Omija juice showed the highest yield at $85^{\circ}C$, 12.5 times water addition and 5 min heating. For soybean curd coagulated with 1.5% Maesil juice showed the highest yield at $85^{\circ}C$, 10 times water addition and 5 min heating. The physical properties (hardness, adhesiveness, chewiness and gumminess) of soybean curd coagulated with juices of Omija and Maesil showed lower values for hardness, adhesiveness, chewiness and gumminess. However sensory scores of both were evaluated higher than those of coagulated with $CaSO_4$. The shelf-life of soybean curd prepared from Omija and Masil juices and then soaked in 0.1% acetic acid was better than that of coagulated with $CaSO_4$ or soaked in distilled water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.156-156
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• 2003

유럽의 여러나라들의 경우 토양내 중금속의 허용치는 그 사용 목적에 따라 다르게 책정되고 있으며 1999년에 제정된 독일의 새로운 토양보전법에서도 토양의 사용목적별로 중금속 허용치를 달리 정하고 있다. 여기서 중금속 농도를 측정하기 위한 방법으로는 DIN(독일 공업규격)에서 정하고 있는 증류수추출법과 왕수추출법이 채택되고 있다. 그러나 이 2가지 방법들은 토양의 중금속분석에서 가장 큰 factor로 작용하는 것이 pH인데 반하여 pH가 7인 증류수와 pH가 0인 왕수를 사용함으로써 실제환경에 적용하기에는 많은 무리수를 내포하고 있으며 차츰 적당치 못한 것으로 판명되고 있다. 실질적인 중금속의 유해성 여부는 토양에서의 그 중금속의 용해도와 유동성으로 결정되는데 강한 산성비가 내린다고 가정하였을 때 비의 pH가 약 4 정도이고 이 경우 식물 뿌리 부분의 pH는 5 정도가 되므로 pH를 기준으로 할 때 잠재적으로 유동가능한 중금속을 분석하는 데에는 pH 4.5 에서 EDTA 추출이 가장 적당하고 또한 이를 토대로 토양내 중금속 허용치를 정하는 것이 합리적이라고 하겠다. 그러나 EDTA는 pH 4에서 부분적으로 Proton과 결합되어 Metal Chelate로의 능력을 잃게 되고 또한 식물 뿌리의 중금속 흡착을 Simulation할 수 없어 불리한 점이 있다. 또한 EDTA는 분해기간이 길고 인체에 해롭다는 것이 알려지고 있어 점점 사용이 어려워지고 있다. 본 연구에서는 토양에 함유된 유동가능한 중금속농도분석을 보다 적절히 하기 위한 방법으로 EDTA와 같이 Carboxyl기가 결합된 고분자 자성체를 이용해 토양의 중금속을 분석하는 것을 제안하였고 분석을 위한 중금속 추출 시 토양시료와 증류수 그리고 고분자 자성체만을 사용하여 근본적으로 토양에서 유동 가능성이 있는 중금속만을 추출하였다. 분석실험은 토양의 Cd2+ 와 Pb2+를 대상으로 행하여졌으며, 여러 토양에서 추출 분석한 결과를 EDTA분석결과와 비교하였다. 실험결과, 중금속은 매우 신속하게 고분자 자성체와 결합하였고, 그 후 자성체를 외부 자장으로 모은 후 산으로 용해시키고, 결합된 중금속은 Graphite furnace AAS로 분석함으로써 빠르고 효율적으로 분석실험을 수행할 수 있음을 알 수 있었다. 한편, 실험에서 나타난 수치들을 비교 검토한 결과 토양 분석시 sandy soil에서는 자성체를 이용한 분석이 EDTA에 의한 방법보다 더 높은 추출도를 보인 반면, silt 함량이 많은 토양의 경우에서 EDTA분석에서 더 높은 중금속 추출도를 보였다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.302-302
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• 2011

• Journal of Life Science
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• v.31 no.7
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• pp.617-625
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• 2021

To enhance the applications of apple pomace, which is a by-product of apple, this study analyzed the nutritional components, ursolic acid content, and antioxidant activity of different solvent (distilled water, fermented alcohol, and methanol) extracts. The samples included hot air-dried and freeze-dried apple pomace. The moisture, protein, fat, ash, and total dietary fiber contents of hot air-dried apple pomace were 3.2%, 3.9%, 2.4%, 2.0%, and 28.5%, respectively, and those of freeze-dried apple pomace were 8.2%, 3.4%, 2.4%, 1.8%, and 33.0%, respectively. Ursolic acid was not detected in the distilled water extract of either sample. However, in hot air-dried apple pomace, the methanol extract was 1,753.32 ㎍/ml, and the fermented alcohol extract was 1,532.94 ㎍/ml. In freeze-dried apple pomace, the methanol extract was 1,407.04 ㎍/ml, and the fermented alcohol extract was 1,221.81 ㎍/ml. The total polyphenol and flavonoid contents were 306.7 ㎍/ml and 950.1 ㎍/ml, respectively in methanol extracts of hot air-dried apple pomace and 277.6 ㎍/ml and 925.0 ㎍/ml, respectively in methanol extracts of freeze-dried apple pomace. 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of hot air-dried apple pomace were 73.3% in methanol extract and 59.4% in fermented alcohol extract, and those of freeze-dried apple pomace were 76.1% in methanol extract and 66.0% in fermented alcohol extract. Both samples had the lowest antioxidant activity in distilled water extracts. Similar to DPPH radical scavenging activity, both samples showed increasing 2,2'-azino-bis(3-ethylbenzothiazoline-6- sulfonic acid) (ABTS) radical scavenging activity in the order of methanol, fermented alcohol, and distilled water. All samples had stronger reducing power than ascorbic acid (311.5 ㎍/ ml) as a positive control.

• Proceedings of the Korean Society of Radiological Science
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• 2001.09a
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• pp.80.2-81
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• 2001

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.55-60
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• 2012

The energy conservation and exergy loss of a fully thermally coupled distillation commercialized as the divided wall column are compared with those of a conventional two-column system for ternary separation. The used example for the comparison is the benzene-toluene-m-xylene separation process widely used in a petrochemical plant. The design procedure of the fully thermally coupled distillation column is explained, and the energy requirement is compared using the HYSYS. When the same numbers of trays are utilized, the fully thermally coupled distillation column uses 28.2% less energy and 10.4% more exergy loss. The increase of the exergy loss is due to the additional mixing from the bidirectional inter-linking and the temperature elevation in the reboiler from the increased pressure at the bottom of the main column.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.3-15
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• 2001

The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.53-63
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• 2005

This study attempted to obtain the basic data of utilizable possibility of preservative treated wood as a material used in a marine ranch. To evaluate the leaching stability of CCA-, CCFZ-, and ACQ-treated woods in seawater, the specimens treated with 2% and 3% (w/v) of CCA, CCFZ, and ACQ were exposed to deionized water, synthetic seawater and natural seawater for 41 days and then each component released was periodically determined. There was little amount of copper and chromium released from CCA-treated wood exposed in both deionized and seawater. Although relatively large amount of arsenic was released from CCA-treated wood, the release rate in seawater was lower than that in deionized water. The release rate of chromium and zinc from CCFZ-treated wood were somewhat greater in deionized water, but lower in seawater than in deionized water. Retention level and salinity of synthetic seawater had little effect on the release rate of components. The ACQ-treated wood had greater copper release than CCA- and CCFZ-treated wood, and the amount of copper released did not affected by leaching media used.

• Membrane Journal
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• v.21 no.3
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• pp.236-246
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• 2011

In this study, we used prepared a cylindrical module consisting 100 hollow fibers of commercialized (hydrophobic) polyethylene membrane of $0.4{\mu}m$ pore size and systematically studied performance of direct contact membrane distillation (DCMD) and sweep gas membrane distillation (SGMD) in terms of variation of permeate flux and salt rejection with respect to temperature drop across the membrane, salt concentrations in feed, and flow rates of cooling water and sweep gas. SGMD was regarded as DCMD with a sweep gas layer between permeate-side membrane surface and cooling water. Sweep gas flow decreases the permeate flux from that of DCMD by providing an additional gas-layer resistance. We compared DCMD and SGMD performance by using mass balance with a fitting parameter (${\omega}$), indicating fraction of permeate flow rate.