• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.313-313
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• 2010

The performance of polymer photovoltaic cells based on blends of poly(3-hexylyhiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) is strongly influenced by blend composition and thickness. Polymer photovoltaic cells based on bulk-heterojunction have been fabricated with a structure of ITO/poly(3, 4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)-pentacene/poly (3-hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM)/Al. We have prepared PEDOT:PSS by dissolving pentacene in N-methylpyrrolidine (NMP) and mixing with PEDOT:PSS. Pentacene was added a maximum concentration of approximately 5.5mg to the PEDOT:PSS solution and sonicated for 10 min. Active layer (P3HT:PCBM) (1:1) was strongly influenced by PEDOT:PSS-pentacene. We have investigated the performance of photovoltaic device with different concentration of P3HT:PCBM (1:1) 2.0wt%, 2.2wt%, 2.4wt% and 2.6wt%, respectively. The photocurrent and power conversion efficiency (PCE) showed a maximum between 2.0wt% and 2.2wt% concentration of P3HT:PCBM. This implied that both morphology and electron transport properties of the layer influenced the performance of the present photovoltaic cells. As the concentration of P3HT:PCBM blends as an active layer was increased, the power conversion efficiency was decreased. P3HT:PCBM layer and PEDOT:PSS-pentacene layer were characterized by work function, UV-visible absorption, atomic force microscopy (AFM), X-ray diffraction (XRD) and scanning electron microscope (SEM).

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.979-984
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• 1997

Test specimens of polymer-cement concrete composites were prepared using styrene-butadiene rubber(SBR) latex, ethylenevinyl acetate(EVA) and polyacrylic ester(PAE) emulsions as polymer dispersions in cement modified system at constant slump($10{\pm}0.5cm$), then compressive and flexural strengths water absorption, pore size distribution, and microstructures were investigated. Compressive and flexural strengths of these composites were remarkably improved with an increase of polymer-cement ratio. These composites had a desirable pore size distribution against frost damage due to a small capillary pore volume. Continuous polymer film was able to form in higher than 15% of polymer cement ratio.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.501-507
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• 2010

In this study, we evaluate the anti-microbiological activity of paraben in eye shadows that are composed of pigments and oil binders using various analytical methods and microbiological tests. Paraben does not show the microbiological activity properly when it was used with Nylon SP$^{(R)}$ 10, Talc RF SSA$^{(R)}$, OMC Talc AS$^{(R)}$ and $BaSO_4$. In the test of fungi, Nylon SP$^{(R)}$ 10 causes the decrease of microbiological activity regardless of the type of oil binders. The pigment of Mango violet also causes the decrease of microbiological activity when ester oil binder was used. Regardless of the type of oil binder, samples containing nylon SP 10, 0.15% of methyl paraben and 0.05% of propyl paraben had not been able to maintain microbiological activity only if the concentration of parabens were increased. Trace amounts of metal ions present in pigments reduced the activity of preservatives by inactivation of hydroxyl group of paraben. It is thought that swollen nylon SP 10 in ester oil increase the absorption or interaction of parabens and swollen nylon powder causes the inactivation of paraben.

• Natural Product Sciences
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• v.15 no.2
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• pp.106-109
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• 2009

Phytochemical investigations of the EtOAc-soluble fraction of the whole plants of Salvia plebeia using repeated column chromatography with preparative HPLC led to the isolation of a new phenylbutanone glucoside, 4-{4-0-[6-(4-hydroxybenzoyl)-0-${\beta}$-D-glucopyranosyl]-3-hydroxyphenyl}-butan-2-one (salviaplebeiaside, 1) along with two known phenolic compounds, rosmarinic acid methyl ester (2) and luteolin-7-0-${\beta}$-D-glucoside (3). The structures of these compounds were determined on the basis of spectroscopic methods including 1D-, 2D-NMR and MS spectrometry and comparison of spectroscopic data with those of values reported in the literatures.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.3-7
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• 1976

This is to reveal the chemical properties of resin of Pinus koraiensis Sieb. et Zvcc, and to give the basic data to resin chemistry and resin processing field. Its results are given; 1) Acid value was shown as 134.12 2) Saponification value was shown as 172.72 3) Iodine value was shown as 109.93 and therefore, it is considered as semi-boiled oil. 4) Ester value was shown as 41.60 5) Moisture content was shown as 11.28% 6) The impurities of resin was shown as 0.09% 7) The amount of turpentine oil was shown as 23.29% 8) Rosin content was shown as 76.74% 9) The amount of resin acid was shown as 72.33% 10) Unsaponification matter was shown as 4.41% 11) The refractive index of resin was shown as 1.5045 at $N^{20}_D$.

• Food Science and Preservation
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• v.12 no.1
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• pp.68-74
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• 2005

This study was carried out to analyze to the flavor components of Lindera obtusiloba BL leaf teas by different processing methods. 81 kinds of flavor components in the masted tea, 78 in the roasted tea after steaming, 88 in the withered tea, 86 in the fermented tea, 72 in the steamed tea, and 89 in the air dried tea ware by GC/MS. Hydrocarbones in Lindera obtusiloba BL leaf teas were 45 kinds of $\beta-piepne$, and 16 kinds of alcohols such as Linalool, n-octanoal, phenyl acetaldehyde, $(-)-\alpha-terpineol$, elemol, and cholest-5-en-3-ol. 11 kinds of ketones sachas 2-ethyl-2- propyl-cyclohexanone, and 8 kinds of aldehydes sach as phenyl acetaldehyde, tetradecanal, 10-undecanal, 4-Bromo-2-methylbutanal were found. Esters were methyl 9,12,15-octadecatrienate, didodecyl phthalace, 1,2-benzenediccarbaboxy acid-bis (2-ethylhexyl)ester and phenols was 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.763-767
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• 2005

Effect of ${\alpha}-amylase$ and various emulsifiers on characteristics of bread dough were examined. Fungal or bacterial ${\alpha}-amylase$ and various emulsifiers including monoglyceride (MG), sodium stearoyl-2-lactylate (SSL), and diacetyltartaric acid ester of mono- and diglycerides (DATEM) were added to bread dough both individually and as mixtures. Rheological characteristics of various bread doughs were examined through falling number, farinograph, alveograph, and rapid visco analysis. Results obtained showed falling number decreased via degradation of starch by ${\alpha}-amylase$. In farinogram, addition of ${\alpha}-amylase$ and emulsifiers in dough decreased consistency, water absorption, mechanical tolerance index, and dough development time. Farinogram characteristic was improved by adding SSL+MG to dough formula. Similar to farinogram addition of ${\alpha}-amylase$ and emulsifiers in alveogram of dough decreased overpressure, extensibility, swelling index, and deformation energy. Whereas addition of ${\alpha}-amylase$ did not affect pasting temperature, viscosity of dough tended to decrease.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.135-149
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• 2002

To date, research on the regulation of melanogenesis has focused on factors which affect tyrosinase, the rate-limiting enzyme in the melanogenic pathway, by searching for chemicals which competitively inhibit tyrosinase function. Many types of tyrosinase inhibitors have been developed, but no satisfactory results have been made clinically until now, To find a new whitening agent, which effectively inhibits melanogenesis, we synthesized several compounds and selected compounds by cell-based assay system. Finally, 3, 4, 5-trimethoxy cinnamaie thymol ester(TCTE, Melasolv) was selected and the effects of TCTE on melanogenesis were investigated. Treatment of mouse-derived melanocyte melan-a cells with TCTE results in a marked down-regulation of tyrosinase activity. 80% decrease of tyrosinase activity occurs with 30uM TCTE treatment for 72 hours without affecting cell growth. The inhibition of tyrosinase activity is dose-dependent and melanin content was also decreased to 40%. From the in vitro tyrosinase assay using cell extract, TCTE does not act as a direct inhibitor of the enzyme. Treatment of melan-a cultures with TCTE blocks the increase in tyrosinase activity by either forskolin, 3-isobutyl-1-methtyl-xanthine. TCTE decreased the expression of tyrosinase, TRP-1 without effects on TRP-2 protein expression through the down regulation of tyrosinase and TRP-1 mRNA. From the results of cAMP immunoassays, intracellular levels of the cyclin nucleotide are unaffected in cells treated with TCTE. The inhibitory effects of melanin synthesis were also shown in reconstitute human epidermis model by topical application. These findings suggest that TCTE can be used for studying the regulation of melanogenesis and depigmenting agent.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1013-1030
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• 2018

Biodiesel is a fuel produced in the form of a fatty acid methyl ester by using raw materials such as animal fat, vegetable oil and its by-products, and is being seen as a biofuel that can replace petroleum energy. However unsaturated fatty acid methyl esters in biodiesel causes to oxidize during storage and distribution, resulting in poor fuel quality and corrosion of vehicle engine components. In this study, the influence of quality and oxidation characteristics of biodiesel on the oxidation stability is investigated and the evaluation method related it is described. We also propose a method to improve the drawback of oxidation stability in biodiesel.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.1
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• pp.47-53
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• 2013

Four new cyclic peroxide compounds (1~4) were isolated from the marine sponge Plakortis simplex. Their structures including relative stereochemistry were determined by MS and NMR analysis. All compounds, a side carbon chain with 10 carbons, were very unstable. After transformation into methyl ester analogues, the structure determination was conducted. Compounds 1a and 2a are stereoisomers, assigned as $3S^*$, $4S^*$, $6R^*$ and $3R^*$, $4S^*$, $6R^*$, respectively. Similarly, compounds 3a and 4a, replaced the methoxy group with an aliphatic methyl, are also stereoisomers. Compounds 1a and 2a exhibited the strong antifungal effect against the fungus Candida albicans.