• Environmental Engineering Research
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• 제23권3호
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• pp.242-249
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• 2018

The use of palm oil and diesel blended with ethanol, known as a microemulsion biofuel, is gaining attention as an attractive renewable fuel for engines that may serve as a replacement for fossil-based fuels. The microemulsion biofuels can be formulated from the mixture of palm oil and diesel as the oil phase; ethanol as the polar phase; methyl oleate as the surfactant; alkanols as the cosurfactants. This study investigates the influence of the three cosurfactants on fuel consumption and exhaust gas emissions in a direct-injection (DI) diesel engine. The microemulsion biofuels along with neat diesel fuel, palm oil-diesel blends, and biodiesel-diesel blends were tested in a DI diesel engine at two engine loads without engine modification. The formulated microemulsion biofuels increased fuel consumption and gradually reduced the nitrogen oxides ($NO_x$) emissions and exhaust gas temperature; however, there was no significant difference in their carbon monoxide (CO) emissions when compared to those of diesel. Varying the carbon chain length of the cosurfactant demonstrated that the octanol-microemulsion fuel emitted lower CO and $NO_x$ emissions than the butanol- and decanol-microemulsion fuels. Thus, the microemulsion biofuels demonstrated competitive advantages as potential fuels for diesel engines because they reduced exhaust emissions.

• ALGAE
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• 제21권2호
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• pp.245-251
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• 2006

Diurnal and age-related changes in air pressure were measured in air bladders of Ascophyllum nodosum from the Atlantic coast of Nova Scotia. Exterior and interior bladder volumes vary significantly with 4 and 6 y bladders being about 40% larger than 2 y bladders (p < 0.01). Freshly collected bladders yielded a mean pressure of 40.8 ± 6.5 cm H2O. Overnight (20 h) dark treatment at 15°C generated pressure reductions by 80% in 2 y bladders but only by about 30% in 4 and 6 y bladders. Furthermore, in 2 y bladders 8 out of 11 bladders were reduced to atmospheric pressure. Pressure losses were inversely related to pressure recovery after 2.5 h in natural daylight, but after 5 h in daylight there was no significant difference in pressure within the age groups. Even under 25% of full illumination, bladders inflated to full pressure after 5 h. The results show that differences in bladder age and bladder wall thickness have roles in diurnal patterns of bladder inflation and deflation. These results confirm that bladder inflation is based on photosynthetic O2 production and not on partial pressures of O2 in the surrounding medium as was suggested for Sargassum. Chemical analyses of fluid recovered after the interior of bladders were washed with saline showed no evidence for the occurrence of surfactant that might be responsible for maintaining the air-liquid interface.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.532-539
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• 2004

For efficient lincomycin production from Streptomyces lincolnensis L1245, various vegetable oils, natural nitrogen sources, and surfactants were investigated at the pilot-scale level in the flask. Olive oil as the sole carbon source was the most suitable one for producing lincomycin. When 20 g/lof olive oil was used, the lincomycin concentration and lipase activity reached 1.01 g/land 182 U/ml, respectively, after 5 days of culture. Among the various unsaturated fatty acids, when linolenic acid was used, the cell growth and lincomycin production were markedly decreased. On the other hand, when 0.2 g/l of oleic acid was added to the culture broth, the maximum lincomycin concentration was 1.0 g/l, which was about 1.7-fold higher than that obtained without the addition of oleic acid. Among the various natural nitrogen sources, pharmamedia or soybean meal was the most suitable nitrogen source. In particular, in the case of a mixture of 10 g/l of pharmamedia and soybean meal, 1.5 g/l of lincomycin concentration and 220 U/ml of lipase activity were obtained. When Span 180 was used as the surfactant, lincomycin production, lipase activity, and oil consumption increased. The correlation between the consumption rates of oil and lincomycin production in a culture using olive oil as the sole carbon source was also investigated. The lincomycin production depended on the consumption rate of olive oil. Using these results, fed-batch cultures for comparing the use of olive oil and starch as a conventional carbon source were carried out in a 5-1 fermentor. When olive oil was used as the sole carbon source, 34 g/l of olive oil was consumed after 7 days of culture. The maximum lincomycin concentration was 3.0 g/l, which was about 2.0-fold higher than that of starch medium after 7 days of culture. The product yield was 0.09 gig of consumed carbon source, which was about 3.0-fold higher than that of starch medium after 7 days of culture.

• 한국응용과학기술학회지
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• 제32권1호
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• pp.157-164
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• 2015

올레아놀릭산은 항암, 신행혈관 생성방지, 항염증, 항산화 및 주름 개선효과가 알려져 있다. 본 연구자들은 천연에서 분리한 올레아놀릭산의 항산화효과에 주목하여 연구하였고 미백효과가 있음을 확인하였다. 본 연구에서는 천연유래의 폴리글리세릴계 계면활성제를 사용하여 간단한 교반만으로 올레아놀릭산을 안정화하였고 고가의 장비인 마이크로풀루다이저를이용하여 제조한 레시틴리포좀과 경피흡수투과율을 비교하였다. 0.4% 올레아놀릭산을 안정화한 폴리글리세릴 나노에멀젼의 12시간 후 경피흡수투과율은 95%였다. 레시틴 리포좀은 92%로 유사하였으나 폴리글리세릴 나노에멀젼은 3시간 경피 흡수투과율이 65%로 레시틴리포좀의 45%에 비해 속방성의 특징을 보였다. 인체대상 임상시험결과 올레아놀릭산을 무배합한 대조군에 비해 올레아놀릭산을 배합한 폴리글리세릴 나노에멀젼은 MEXAMETER의한 멜라닌 색소감소효과가 2주차 25%, 4주차 58%, 8주차 58%이상 높았다.

• Applied Biological Chemistry
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• 제50권1호
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• pp.12-17
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• 2007

태백산 토양에서 유화활성과 안정도가 높은 biosurfactant 생산균주 TBM 3101을 분리하여 동정한 결과 B. subtilis로 판명되었다. B. subtilis TBM 3101의 배양액에서 표면장력은 최저 29mN/m까지 감소되었고, 이후 장시간 계속 유지되었다. 또한, tributyrin을 기질로 사용하였을 때 2.68로 가장 큰 유화력을 보였고, 그 외에 soybean oil, crude oil, tetradecane 에서도 비슷한 활성을 보였다. 각종 다른 합성계면활성제의 유화활성 및 안정성을 고려하여 비교 분석한 결과 B. subtilis TBM 3101 생산하는 biosurfactant는 tween류와 span 85와 유사한 유화활성을 나타내었고, tween 80과 triton X-100과 비슷한 유화 안정도를 보여주었다.

• 공업화학
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• 제22권2호
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• pp.173-177
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• 2011

본 연구에서는 정수장의 alum 슬러지로부터 $AlPO_4$-계 다공성 물질의 합성과정을 규명하고자 가정용 세제, 휴믹산, 아미노산 등과 같은 유기물질을 틀로 사용하여 $Al(OH)_3$과 인산으로부터 $AlPO_4$-계 다공성 물질을 합성하였으며, $600^{\circ}C$의 공기 중에서 소성을 통하여 틀로 사용한 유기물질을 제거하였다. X-선 회절 분석 결과 합성된 물질은 $AlPO_4$-계 다공성 물질의 특징적인 패턴을 나타내었으며, 물질의 형태적인 특성은 주사전자현미경을 이용하여 관찰하였다. $^{27}Al$ MAS NMR 분석을 통하여 $Al^{3+}$ 이온 주변의 화학적 배위환경의 변화를 관찰하였다. 소성 전 물질에는 4배위와 6배위된 $Al^{3+}$ 이온이 함께 존재하지만, 소성 후 물질에서 $Al^{3+}$ 이온은 모두 4배위 환경에 존재하였다. 합성된 고체 내부에 형성된 기공은 BET 비표면적 측정으로 확인하였다. 최종적으로 합성된 물질의 응용으로 공기 중 유해 포름알데히드 제거 실험을 실시하였으며, 포름알데히드 분자가 물질에 존재하는 기공 표면에 흡착됨을 확인하였다. 결론적으로, alum 슬러지로부터 얻어진 $AlPO_4$-계 다공성 재료를 유해 기체의 흡착 및 제거에 활용할 수 있는 가능성을 제시하였다.

• Journal of Pharmaceutical Investigation
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• 제38권4호
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• pp.241-247
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• 2008

Paclitaxel is a taxane diterpene amide, which was first extracted from the stem bark of the western yew, Taxus brevifolia. This natural product has proven to be useful in the treatment of a variety of human neoplastic disorders, including ovarian cancer, breast and lung cancer. Paclitaxel is a highly hydrophobic drug that is poorly soluble in water. It is mainly given by intravenous administration. Therefore, The pharmaceutical formulation of paclitaxel ($Taxol^{(R)}$; Bristol-Myers Squibb) contains 50% $Cremophor^{(R)}$ EL and 50% dehydrated ethanol. However the ethanol/Cremophor EL vehicle required to solubilize paclitaxel in $Taxol^{(R)}$ has a pharmacological and pharmaceutical problems. To overcome these problems, new formulations for paclitaxel that do not require solubilization by $Cremophor^{(R)}$ EL are currently being developed. Therefore this study utilized a supercritical fluid antisolvent (SAS) process for cremophor-free formulation. To select hydrophilic polymers that require solubilization for paclitaxel, we evaluated polymers and the ratio of paclitaxel/polymers. HP-${\beta}$-CD was used as a hydrophilic polymer in the preparation of the paclitaxel solid dispersion. Although solubility of paclitaxel by polymers was increased, physical stability of solution after paclitaxel/polymer powder soluble in saline was unstable. To overcome this problem, we investigated the use of surfactants. At 1/20/40 of paclitaxel/hydrophilic polymer/ surfactant weight ratio, about 10 mg/mL of paclitaxel can be solubilized in this system. Compared with the solubility of paclitaxel in water ($1\;{\mu}g/mL$), the paclitaxel solid dispersion prepared by SAS process increased the solubility of paclitaxel by near 10,000 folds. The physicochemical properties was also evaluated. The particle size distribution, melting point and amophorization and shape of the powder particles were fully characterized by particle size distribution analyzer, DSC, SEM and XRD. In summary, through the SAS process, uniform nano-scale paclitaxel solid dispersion powders were obtained with excellent results compared with $Taxol^{(R)}$ for the physicochemical properties, solubility and pharmacokinetic behavior.

• 대한화장품학회지
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• 제23권3호
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• pp.92-96
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• 1997

Nowadays, ceramides have been found to be an important component in the outermost layer of the skin - the stratum corneum. It is undersrood that ceramides play an important role in structure and maintenance of the interellular lipid lamella structure in the SC layer. Thus, many efforts have been made by the cosmetics and pharmaceutical industries to get human skin-identical ceramides or pseudoceramides which show similar performance with natural ceramides. The purpose of our study was to systhesize new pseudoceramides via an effective and economical systhetic pathway and to show their performance of skin restoratio. Four kinds of the new pseudoceramides were synthesized by the reaction of alcoholic amine and alkyl ketene dimer. First of all, PC-4 and PC-5 were synthesized by the reaction of 3-amino-1,2-propanidiol and serinol with alkyl ketene dimer respectively. After that, PC-4R and PC-5R were produced by changign kitone group at $\beta$-position to amide bond of above synthesized PC-4 and PC-5 into hydroxyl group using NaBH4 respectively. Their expected structures were conformed by the NMR, IR spectra, and elemental analysis. A study to show the restoration effectiveness was performed in which human skin was pretreated with high concentration of SDS surfactant solution. Using 0.5% solution of above synthesized pseudoceramides, there was the significantly faster restoration of the damaged than that of placebe itself treatment.

• KSBB Journal
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• 제30권6호
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• pp.291-295
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• 2015

The limited productivity of natural shell matrix proteins has hampered the investigation of their biochemical properties and practical applications, although biominerals in nature obtained by organic-inorganic assemblies have attractive mechanical and biological properties. Here, we prepared a vector for the expression of a fusion protein of a shell matrix protein from Pinctada fucata (named as GRP_BA) with the GRGDSP residue. The fusion protein of BA-RGD was simply produced in E. coli and purified through sequential steps including the treatment with $CaCl_2$ and EDTA solution for cell membrane washing, mechanical cell disruption and the application of non-ionic surfactant of Triton X-100 for BA-RGD inclusion body washing. The production yield was approximately 60 mg/L, any other protein band was not observed in SDS-PAGE and it was estimated that above 97% endotoxin was removed compared to the endotoxin level of whole cell. This study showed this simple and easy purification approach could be applied to the purification of BA-RGD fusion protein. It is expected that the protein could be utilized for the preparation of biominerals in practical aspects.

• Journal of Electrochemical Science and Technology
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• 제11권1호
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• pp.50-59
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• 2020

Birnessite-type manganese dioxide (δ-MnO₂) with hierarchical micro-/mesoporosity was synthesized via sacrificial graphene template approach under mild hydrothermal conditions for the first time. Graphene template was obtained by a surfactant (cetyltrimethylammonium bromide, CTAB) assisted liquid phase exfoliation (LPE) in water. A thin PEDOT:PSS (poly (3,4-ethylene dioxythiophene): poly (styrene sulfonate)) layer was applied to improve electrical conductivity and rate capability of MnO₂. The MnO₂ (535 F g^-1 at 1 A g^-1 and 45 F g^-1 at 10 A g^-1) and MnO₂/PEDOT:PSS nanocomposite (550 F g^-1 at 1 A g^-1 and 141 F g^-1 at 10 A g^-1) delivered electrochemical performances superior to their previously reported counterparts. An asymmetric supercapacitor, composed of MnO₂/PEDOT:PSS (positive) and Fe₃O₄/Carbon (negative) electrodes, provided a maximum specific energy of 18 Wh kg^-1 and a maximum specific power of 4.5 kW kg^-1 (ΔV= 2 V, 1M Na₂SO₄) with 85% capacitance retention after 1000 cycles. The graphene-templated MnO₂/PEDOT:PSS nanocomposite obtained by a simple and green approach promises for future energy storage applications with its remarkable capacitance, rate performance and cycling stability