• Archives of Pharmacal Research
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• 제28권4호
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• pp.502-508
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• 2005

Titrated extract of Centella asiatica (TECA) contains three principal ingredients, asiaticoside (AS), asiatic acid (AA), and madecassic acid (MA). These components are known to be clinically effective on systemic scleroderma, abnormal scar formation, and keloids. However, one problem associated with administration of TECA is its low solubility in aqueous as well as oil medium. In this study, various nonionic surfactants and bile salts as anionic surfactant were tested and screened for solubilizing TECA with a view to developing topical hydrogel type of ointment which is stable physicochemically, and has better pharmacological effects. When TECA was incorporated into various nonionic surfactant systems, labrasol had the most potent capacity for solubilizing TECA. In cases of bile salt systems, Na-deoxycholate (Na-DOC) had foremost solubilizing capacity, even more than labrasol. In differential scanning calorimetric study, the peaks of AA, MA, AS and Na-DOC disappeared at the coprecipitate of $1\%$ TECA and $1\%$ Na-DOC, suggesting the optimum condition of Na-DOC for solubilizing TECA. When the physicochemical stability of hydrogel containing this mixture was assessed, it was stable at room temperature for at least one month. Pharmacologically it significantly decreased the size of wound area at the $9^{th}$ day when applied to the wound area of rat dorsal skin. Taken together, solubility of TECA was dramatically improved by using non ionic and anionic surfactant systems, and Na-DOC was found to be the most effective solubilizer of TECA in formulating a TECA-containing hydrogel typed ointment. Moreover this gel was considered to be applicable to clinical use for wound healing effect.

• 자원리싸이클링
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• 제21권6호
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• pp.45-50
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• 2012

리튬 리싸이클링의 일환으로 상온 전해법으로 금속형태의 리튬을 회수하는 연구를 수행하였다. 리튬 전해액으로 이온성액체인 PP13TFSI에 리튬염으로 LiTFSI를 용해시켜 사용하였으며, 작동전극으로 금, 백금 및 구리를 각각 적용하였다. 작동전극 상에서 조사한 순환전위주사 실험 결과로부터 리튬의 상온 전해환원에 대한 가능성을 확인하였으며, 백금이나 구리의 경우 보다 금 전극에서 리튬 환원전류가 더 크게 나타났다. 정전위법(-2.4 V vs. Pt-QRE)으로 1시간동안 금 전극 상에 전착한 다음, 전극표면을 SEM-EDS 및 XRD 분석을 하였다. 전착된 리튬은 금속 리튬 혹은 금과의 합금 형태이었으며, 침상형으로 균일하게 전착되었음을 확인하였다. 또한 전착물에 미량의 산소가 검출되는 것은 분석과정에서 시편이 공기 중에 노출되었기 때문으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권6호
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• pp.32-37
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• 2013

The scope of this study was to develop, design, and build an ex-situ remediation system of using the heating and water sparging treatment for the highly volatile DNAPL (Dense Non-Aqueous Phase Liquid) contaminated groundwater, and to conduct pilot testing at the site contaminated with DNAPL. The TCE (Trichloroethylene) removal was at the highest rate of 94.6% with the water sparging at $70^{\circ}C$ in the lab-scale test. The pilot-scale remediation system was developed, designed, and fabricated based on the results of the lab-scale test conducted. During the pilot-scale testing, DNAPL-contaminated groundwater was detained at heat exchanger for the certain period of time for pre-heating through the heat exchanger using the thermal energy supplied from the heater. The heating system supplies thermal energy to the preheated DNAPL-contaminated groundwater directly and its highly volatile TCE, $CCl_4$ (Carbontetrachloride), Chloroform are vaporized, and its vaporized and treated water is return edback to the heat exchanger. In the pilot testing the optimum condition of the HWSRS was when the water temperature at the $40^{\circ}C$ and operated with water sparging concurrently, and its TCE removal rate was 90%. The efficiency of the optimized HWSRS has been confirmed through the long-term performance evaluation process.

• Nuclear Engineering and Technology
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• 제43권6호
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• pp.557-566
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• 2011

A cold spray coating (CSC) of copper was studied for its application to a high-level radioactive waste (HLW) disposal canister. Several copper coatings of 10 mm thick were fabricated using two kinds of copper powders with different oxygen contents, and SS 304 and nodular cast iron were used as their base metal substrates. The fabricated CSC coppers showed a high tensile strength but were brittle in comparison with conventional non-coating copper, hereinafter defined to as "commercial copper". The corrosion behavior of CSC coppers was evaluated by comparison with commercial coppers, such as extruded and forged coppers. The polarization test results showed that the corrosion potential of the CSC coppers was closely related to its purity; low-purity (i.e., high oxygen content) copper exhibited a lower corrosion potential, and high-purity copper exhibited a relatively high corrosion potential. The corrosion rate converted from the measured corrosion current was not, however, dependent on its purity: CSC copper showed a little higher rate than that of commercial copper. Immersion tests in aqueous HCl solution showed that CSC coppers were more susceptible to corrosion, i.e., they had a higher corrosion rate. However, the difference was not significant between commercial copper and high-purity CSC copper. The decrease of corrosion was observed in a humid air test presumably due to the formation of a protective passive film. In conclusion, the results of this study indicate that CSC application of copper could be a useful option for fabricating a copper HLW disposal canister.

• 한국식품영양과학회지
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• 제26권4호
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• pp.606-613
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• 1997

멸치에 일정량의 식염, 아질산염, 질산염 및 아스코르브산을 첨가하여 숙성시키면서, NA생성에 미치는 영향에 대해 조사한 결과는 다음과 같다. pH는 담금직 후 7.1에서 숙성 110일 후 5.5로 산성화되었다. TMAO 질소는 숙성 중 감소한 반면, TMA 및 DMA질소는 증가하였다. 아질산염 첨가구는 숙성 중 NDMA 함랑이 증가하였고, 아스코르브산 첨가구는 NDMA 생성이 억제되었다. 모델계 실험 결과, 멸치젓의 니트로소화 최적 pH는 3.8이었고, 아스코르브산은 NDMA생성을 크게 억제시킨 반면 thiocyanate는 촉진시켰다. 본 실험 결 과, 멸치젓 자체에는 NDMA가 거의 검출되지 않았으나, 질산염이나 아질산염의 함량이 많은 물질과 함께 섭취된다면 위내에서 NDMA가 생성될 가능성이 충분한 것으로 판단되었다.

• 방사선산업학회지
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• 제7권1호
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• pp.87-91
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• 2013

Taraxacum platycarpum (TP) has been used for years without restriction on usual dose for its non-toxic nature and nonexistence of the side effects. To develop antimicrobial hydrogel, poly (vinylalcohol) (PVA) hydrogels containing the aqueous extracted TP as an antimicrobial agent were prepared by using gamma-rays irradiation. The antimicrobial activities of the TP hydrogels were tested against Staphylococcus aureus and Staphylococcus epidermidis by disc diffusion method. The inhibition zones (IZ) of the TP extracts and TP hydrogels against S. aureus were 16 mm and 20 mm and against S. epidermidis was 10 mm and 13 mm, respectively. In conclusion, the TP hydrogel that has an excellent antimicrobial activity was proved to be a valuable material for functional skin care.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권6호
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• pp.80-90
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• 2014

The laboratory and field studies were conducted to identify an optimal injection concentration of nanoscale zero-valent iron particles (NZVI) and to evaluate the applicability of NZVI-based reactive zone technology to the site contaminated with trichloroethylene (TCE) DNAPL (Dense Non-Aqueous Phase Liquid). The laboratory test found an optimal injection concentration of NZVI of 5 g/L that could remove more than 95% of 0.15 mM TCE within 20 days. Eleven test wells were installed at the aquifer that was mainly composed of alluvial and weathered soils at a strong oxic condition with dissolved oxygen concentration of 3.50 mg/L and oxidation-reduction potential of 301 mV. NZVI of total 30 kg were successfully injected using a centrifugal pump. After 60 days from the NZVI injection, 86.2% of the TCE initially present in the groundwater was removed and the mass of TCE removed was 405 g. Nonchlorinated products such as ethane and ethene were detected in the groundwater samples. Based on the increased chloride ion concentration at the site, the mass of TCE removed was estimated to be 1.52 kg. This implied the presence of DNAPL TCE which contributed to a higher estimate of TCE removal than that based on the TCE concentration change.

• 한국약용작물학회지
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• 제27권4호
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• pp.259-270
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• 2019

Background: Eucommia ulmoides has long been used as an herbal medicine for the treatment of diabetes, hypertension and other diseases in many Asian countries. Methods and Results: This study aimed at evaluating the antioxidant and anti-inflammatory properties of its water (EU-DW, and REU-DW) and ethanol (EU-EtOH, and REU-EtOH) extracts, as well as those of non-roasted E. ulmoides (EU) and roasted EU (REU) cortex. The following were assessed in each extract: total phenolic and flavonoid contents, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitrite radical scavenging activities, reducing power, DNA damage prevention activity, and nitric oxide (NO) inhibition activity. Both EU and REU extracts showed high phenolic and flavonoid content, dose-dependent DPPH radical scavenging capacity, high reducing activity, and considerable DNA damage prevention activity. EU extracts showed remarkable ABTS free radicals scavenging capacity. REU extracts showed a higher radical scavenging capacity and played an important role in inhibiting NO production. Conclusions: The results of this study suggested that aqueous and ethanol extracts of EU and REU possess antioxidant capacities, and prevent oxidative damage to DNA, probably owing to their phenolic and flavonoid content. Therefore, EU and REU could be candidates antioxidant supplements.

• 공업화학
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• 제30권3호
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• pp.352-357
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• 2019

본 연구에서는 3-butenoic acid와 폴리옥시에틸렌(20) 스테아릴 에테르를 사용하여 비닐기를 가진 반응성 유화제를 합성하였다. 합성 반응성 유화제는 FT-IR 및 $^1H-NMR$에 의해 확인되었다. 또한, 아크릴계 점착제의 제조에서 합성된 반응성 유화제와 통상적으로 사용되는 비이온성 유화제를 사용하여 각각의 점착제의 특성을 비교하였다. 고형분 함량은 56.8~57.4%의 범위에서 측정되었다. 초기 접착의 경우, 반응성 유화제로 제조된 S20BA는 $^{\sharp}13$으로 측정되었다. 제조된 접착제의 박리강도는 $0.66{\sim}1.05kg_f$의 범위에서 측정되었고 S20BA를 사용한 경우 가장 높은 박리 강도가 측정되었다. 내열성 시험 결과, S20BA의 내열성이 $840^{\circ}C$로 가장 높았다. 피부용 접착제에 대한 응용성을 평가하기 위하여 pH는 중성 7로 측정되었으며, 일차 피부 자극 시험의 결과로 비자극성으로 측정되었다.

• 멤브레인
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• 제29권5호
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• pp.292-298
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• 2019

본 연구에서는 축전식 탈염 공정에 분할 전극을 이용하여 탈염 성능을 향상하고자 하였다. 운전조건으로 NaCl 수용액에 대하여 20 mL/min의 유속과 1.2 V, 3분의 흡착 조건과 -1 V, 1분의 탈착 조건으로 전극의 분할 여부에 따른 탈염 효율을 측정함으로써 실험을 진행하였다. 분할되지 않은 전극에서는 유효면적이 $146cm^2$일 때 40%의 탈염 효율이 나타났고 분할 전극의 유효면적이 $133cm^2$일 때 57%의 탈염 효율을 보였다. 같은 분할된 전극에서 탈염 효율은 2 cm 간격을 두었을 때 49%, 1 cm의 간격을 두었을 때 57%로 확인되었다. 탈염 효율이 일반 CDI보다 분할 전극 CDI가 높았고 분할 전극 사이의 간격이 좁을수록 증가하였다.