• 한국해양환경ㆍ에너지학회지
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• 제6권3호
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• pp.54-62
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• 2003

본 연구에서는 다양한 침몰선박 잔존유회수 방법 중에서 안전성과 경제성을 바탕으로 우리나라 해역특성에 적합한 무인 원격회수방법을 선정하였다. 이와 함께 우리나라 전 연안에서 회수작업을 실행할 수 있는 작업 수심 200m급 잔존유 무인회수시스템(Remotely Operated Recovery System)의 요구사양을 선정하고 회수장비에 대한 기본설계를 수행하였다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.337-337
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• 2004

As one of researches for the P ＆ T purposes, a basic experiment on the recovery of actinide elements from the mixture with rare earth elements by means of electrorefining using a liquid cadmium cathode in the LiCl-KC1 eutectic melt was carried out. In order to examine the behaviors of electrodeposition of metal ions on a liquid electrode, recovery experiments of rare earth metals resulting from forming electrodeposits were performed by a galvanostatic electrolysis method at various current densities. A cyclic voltammetric technique was applied to determine reduction-oxidation potential of each metal element in the melt and to detect the changes of the multi component melt composition for on-line monitoring. Also, a collaboration study with RIAR was completed to test the preliminary feasibility on a recovery of actinide elements from the mixture with rare earth elements using a liquid cadmium cathode and actinide metals. Experimental results showed that the ratio of actinides to rare earths, 9: 0.5∼1 led to the rare earth content of about 5∼10 wt% in the deposit.

• Progress in Superconductivity
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• 제9권1호
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• pp.119-125
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• 2007

We investigated recovery in $Au/YBa_2Cu_3O_7$ (YBCO) thin film meander lines on sapphire substrates. The meander lines were fabricated by patterning YBCO films coated with gold layers. The lines were subjected to simulated AC fault current and then small current was applied for recovery measurements. The samples were immersed in liquid nitrogen during the experiment. After the fault, the resistance decreased linearly, first slowly and then fast to zero. The initial slow decrease was due to the decrease of the meander line temperature, whereas the fast decrease was originated from the transition from the normal state to the superconducting state. The recovery speed depended on the size of samples, and was faster in the smaller samples during the whole period of recovery. The experimental results were analyzed quantitatively with the concept of heat transfer within the sample and to the surrounding liquid nitrogen. A heat balance equation was solved for the initial phase of recovery, and an expression for the time dependence of resistance was obtained. The result agreed with data well.

• Food Science and Biotechnology
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• 제18권2호
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• pp.565-569
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• 2009

This study was conducted to evaluate the effects of different preparation methods on the recovery and quantification of ginsenosides in raw Korean ginseng (Panax ginseng C.A. Meyer). Eight major ginsenosides ($Rb_1$, $Rb_2$, $Rb_3$, Rc, Rd, Re, Rf, and $Rg_1$) were analyzed by high performance liquid chromatography (HPLC), after which the recovery and repeatability of the extraction of those ginsenosides using 3 different preparation methods were compared [A. direct extraction (DE) method, hot MeOH extraction/evaporation/direct dissolution; B. solid phase extraction (SPE) method, hot MeOH extraction/evaporation/dissolution/$C_{18}$ cartridge adsorption/MeOH elution; C. liquid-liquid extraction (LLE) method, hot MeOH extraction/evaporation/dissolution/n-BuOH fractionation]. Use of the DE method resulted in a significantly higher recovery of total ginsenosides than other methods and a relatively clear peak resolution. Use of the SPE and LLE methods resulted in clearer peak resolution, but lower ginsenoside recovery than the DE method. The LLE method showed the lowest ginsenoside recovery and repeatability among the 3 methods. Given that the DE method employed only extraction, evaporation, and a dissolution step (avoiding complicate and time consuming purification), this technique may be an effective method for the preparation and quantification of ginsenosides from raw Korean ginseng.

• Membrane and Water Treatment
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• 제4권4호
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• pp.277-291
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• 2013

The transport and recovery of Levafix brilliant red E-4BA and Levafix brilliant red E-6BA were investigated using polytetrafluoroethylene (PTFE) fiber based supported liquid membrane containing tetra butyl ammonium bromide (TBAB) in coconut oil as a carrier. The influencing parameters studied are: pH of the feed solution, concentration of dye in the feed solution, extractant concentration, and various kind of stripping agent, rate of stirring, time of transport, reusability of membrane and stability of membrane. Increase in TBAB concentration inside the membrane enhances the flux with its maximum value at $1.553{\times}10^{-4}$ M TBAB. Further increase in the concentration of TBAB leads to decreased rate of transport due to increase in viscosity of membrane liquid. The optimum conditions for dye transport are: pH of feed ($7{\pm}0.1$), $1.553{\times}10^{-4}$ M extractant concentration, 350 rpm for stirring, $4.9{\times}10^{-1}$ M potassium hydrogen phthalate as a stripping solution, the time of transport 6 h. It was noticed that flux values were increased with increasing dye concentration in the feed phase. Applying this study to textile wastewater, dyes were transported up to 98% in 6 h. This recovery technique is rewarding to environment and economic.

• 분석과학
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• 제13권3호
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• pp.399-402
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• 2000

To determine the concentrations of microcystins present in lake water or in tap water using high performance liquid chromatography, it is necessary to concentrate a large volume of water samples (about 20 L) into very small volume (0.1-0.3 mL). Concentration can be conveniently done when disc type solid phase extraction (SPE) apparatus is used. Using this apparatus we have investigated the recovery rates of three kinds of microcystins, RR, YR, LR. The recovery rates were relatively low and the reproducibilities were not good either. It is expected, however, that the appropriate selection of the disc conditioning and eluting solvents and reproducible reconcentration process after SPE will improve both the recovery rates and the reproducibilities.

• Environmental Analysis Health and Toxicology
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• 제16권3호
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• Preventive Nutrition and Food Science
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• 제4권3호
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• pp.167-170
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• 1999

Various concentrations of malonaldehyde (MA) produced upon hydrolysis of 1, 1, 3,3-tetraethoxypropane (TEP) were reacted with 2-thiobarbituric acid (TBA)and th e contents of MA-TBA complex were measured both with spectrophotometer and high performance liquid chromatography (HPLC). As the concentrations of MA-TBA increased, their absorbances and the corresponding HPLC peak areas increased. The correlation coefficient between absorbances and HPLC peak areas of MA-TBA peaks from the other compounds and butanol extraction of the complex increased its recovery its recovery by 29.4% . Measurement of the content of MA-TBA complex for monitoring the development of lipid oxidation was proven to be successful with the use of high performance liquid chromatography.

• 한국수산과학회지
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• 제41권1호
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• pp.13-19
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• 2008

Malachite green (MG), a triphenylmethane dye, is carcinogenic, mutagenic, teratogenic, a respiratory toxin, and causes chromosomal fractures. It is not permitted for use as an aquaculture veterinary drug in a number of countries. Sensitive extraction methods for MG and leucomalachite green (LMG), which have long residence times in fish tissues, were developed. For LMG, the average recovery of liquid extraction (LE) ranged from 41.71 (yellowtail) to 71.60% (snakehead); the recovery of liquid-liquid extraction (LLE) was between 67.68 (yellowtail) and 83.68% (snakehead); and the average recovery of solid-phase extraction (SPE) ranged from 84.16 (yellowtail) to 92.92% (shrimp). The recovery of MG was less than 30% with SPE. However, the dye is found primarily as the colorless reduced leuco form in fish tissues.

• Korea Journal of Cosmetic Science
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• 제1권1호
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• pp.19-29
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• 2019

In this work, we fabricated liquid crystal (LC) emulsions with fatty alcohol in order to stabilize high content ceramide in cosmetic formulation. We investigated the role of fatty alcohol and surfactant in the formation of higher order structure. As a result, we found that they play a crucial role to form higher order structure. SAXS study shows that ceramide can be incorporated up to 3% in cosmetic formulation with higher order structure and its stability was maintained up to 12 weeks at room temperature. According to WAXS study, the higher order structure can suppress the re-crystallization of ceramide in cosmetic formulation. Finally, we performed in vivo skin barrier recovery test for the damaged skin. LC emulsions with ceramide and O/W emulsions show significant effect in skin barrier recovery at D 1, D 2 and D 6 compared to the untreated condition. While only LC emulsions show significant skin recovery effect at D 14. We expect that LC emulsions are the promising skin carrier to stabilize ceramide and LC emulsions with ceramide can improve the skin barrier function.