• Korean Journal of Weed Science
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• v.32 no.2
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• pp.98-106
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• 2012

This research has been carried out to find out the highest effect on insecticidal, fungicidal and herbicidal activities in leaves, stem and tuber extracts of yacon (Smallanthus sonchifolius) and extraction methods such as water, boiling water and methanol. Characteristics of potential herbicidal components among extraction methods were investigated by solvent fractions such as hexane, chloroform, ethyl acetate, butanol, and water. Generally, methanol extract was the best on inhibition of germination rate, plant height, and root length in cucumber and barley. On the other hand, the inhibition effect on growth in cucumber and barley was the best in tuber among plant parts of yacon. Inhibition of germination rate, plant height, and root length in cucumber and barley in solvent fractions was the best in water fraction, but there were no differences in other fractions. Digitaria sanguinalis L. and Solanum nigrum L. by 5 and 10% extractions of yacon tuber were controlled by more than 70~80% and 95~100%, respectively. However, there was no inhibition effect on foliar treatment in cucumber and barley as affected by 5 and 10% extractions of yacon tuber. Mortality of green peach aphid (Myzus persicae Sulzer) was 50% at 3 days after treatment of 5% extracts of yacon leaves. Mortality of brown plant hopper (Nilaparvata lugens Stal) was only 24% in 5% extracts of stems and leaves with midrib, but was 57% in 5% extracts of leaves without midrib. There was no fungicidal effect on anthracnose (Colletotrichum truncatum), wilt disease (Fusarium oxysporum), verticillium wilt (Verticillium dahliae), bacterial blight (Xanthomonus oryzae) in 5% extracts of yacon leaves.

• Journal of Life Science
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• v.24 no.1
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• pp.26-38
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• 2014

To examine the antioxidant activities of 11n selected miscellaneous cereal grains (proso millet, yellow glutinous proso millet, hwanggeumchal sorghum, glutinous sorghum, white glutinous sorghum, yellow glutinous foxtail millet, nonglutinous foxtail millet, green glutinous foxtail millet, golden foxtail millet, barnyard millet, and adlay), the free radical-scavenging activities of 80% ethanol extracts of the individual grains were investigated using 1,1-diphenyl-2-picryl-hydrazl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods. The ethanol extracts of hwanggeumchal sorghum, glutinous sorghum, and barnyard millet grains exhibited more potent free radical-scavenging activities as compared to the other grains. When these three ethanol extracts were sequentially fractionated with n-hexane, methylene chloride, ethyl acetate, and n-butanol, the majority of the antioxidant activities were detected in the ethyl acetate and butanol fractions in which phenolic ingredients were abundant. The ethyl acetate and butanol fractions of hwanggeumchal sorghum and the ethyl acetate fraction of glutinous sorghum showed higher antioxidant activity than that of ${\alpha}$-tocopherol. Both ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods demonstrated that these organic solvent fractions could inhibit lipid peroxidation. The ethyl acetate fractions from hwanggeumchal sorghum, glutinous sorghum, and barnyard millet grains could suppress tertiary-butyl hydroperoxide (TBHP)-induced apoptotic events, including sub-G1 peaks, ${\Delta}{\Psi}m$ loss, activation of caspase-9 and caspase-3, and cleavage of PARP and lamin B, in human HL-60 cells. These results show that the grains of hwanggeumchal sorghum (Sorghum bicolor L. Moench cv. Hwanggeumchalsusu), glutinous sorghum (Sorghum bicolor L. Moench cv. Chalsusu), and barnyard millet (Echinochloa esculenta) possess efficient antioxidant activity, which could protect cells from oxidative stress-mediated cytotoxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1194-1199
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• 2015

Vitamin $K_1$ (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin $K_1$ were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin $K_1$ in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to $1,467.3{\mu}g/100g$. The content of vitamin $K_1$ in fruits ranged from ND to $42.7{\mu}g/100g$. The content of vitamin $K_1$ in legumes, including soybeans, mung beans and peas ranged from 1.7 to $63.4{\mu}g/100g$. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.320-324
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• 2011

TOPO/TOP capped CdSe nanoparticles were synthesized via thermal-solvent method. The 540 nm green and 620 nm red emitting CdSe nanoparticles were obtained by controlling the reaction time and temperature. Phosphor conversion white LED was produced combining a 460 nm emitting InGaN LED chip as an excitation source with 540 and 620 nm CdSe nanoparticles as phosphors. The single or double phosphor layer was fabricated by mixing with epoxy, and investigated the effects on the luminous properties of the white LED. The single phosphor layer white LED showed 5.78 lm/W with CIE of (0.36, 0.45) in reddish white, and the double phosphor layer white LED showed 7.28 lm/W with that of (0.32, 0.34) in pure white at 20 mA. When the 400 nm near-UV LED was applied to optical pumping source, the luminous efficiency of white LED was enhanced to 8.76 lm/W.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.334-341
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• 2000

The DMPT produced by marine algae is the main biogenic precursor of oceanic DMS. Also, DMPT is an efficient stimulant for growth, feeding, and body movement of fish and striped prawn, and appears to play a physiologic role as an osmoprotectant in algae. This study was focused on the extraction of dimethyl-$\beta$-propiothetin as bioactive substance from green seaweed. Identification and quantification of dimethyl-$\beta$-propiothetin were measured by headspace gas chromatography after conversion to dimethyl sulfide by treatment with saturated NaOH solution. Dimethyl-$\beta$-propiothetin was extracted through various processes(solvent extraction, ultrasonication, boiling and autoclaving) from Enteromorpha intesinalis. The content of dimethyl-$\beta$-propiothetin extracted by autoclaving treatment showed higher than those of various extraction methods. Dimethyl-$\beta$-propiothetin content in extract of Enteromorpha Enteromorpha was 311,200ng/g after autoclaving at 121$^{\circ}C$ for 60min. Dimethyl-$\beta$-propiothetin in extract of Enteromorpha intestinalis was comparatively stable under low temperature. The retentions of dimethyl-$\beta$-propiothetin content in extract of Enteromorpha intestinalis were 75.8 ~99.8% by incubation at 10~6$0^{\circ}C$ for 2 hours. Chemical decomposition of dimethyl-$\beta$-propiothetin was observed under laboratory conditions at pH values higher than 9.5.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.737-742
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• 2015

An environmentally favorable solid oxidizer, guanidine dinitramide ($H_2C(NH_2)NH_2N(NO_2)_2$), with high purity and synthesis yield was prepared using guanidine carbonate ($NH_2C(=NH)NH_2{\cdot}1/2H_2CO_3$). Two different crystalline forms (${\alpha}$-form and ${\beta}$-form) were obtained depending on the solvent used and synthesis process. Despite of the same chemical composition, Raman-IR and TGA-DSC revealed that different structures existed between them. In particular, the thermal analysis showed the exothermic temperature of ${\alpha}$-form at $155.7^{\circ}C$ while $191.6^{\circ}C$ for ${\beta}$-form. The caloric value of ${\alpha}$-form was 536.4 J/g which was 2.5 times larger than that of ${\beta}$-form, 1310 J/g. In addition, ${\alpha}$-form was steeply decomposed with one-step variation, but ${\beta}$-form followed a two-step thermal decomposition pattern.

• Journal of Powder Materials
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• v.17 no.4
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• pp.312-318
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• 2010

High speed steels (HSS) were used as cutting tools and wear parts, because of high strength, wear resistance, and hardness together with an appreciable toughness and fatigue resistance. Conventional manufacturing process for production of components with HSS was used by casting. The powder metallurgy techniques were currently developed due to second phase segregation of conventional process. The powder injection molding method (PIM) was received attention owing to shape without additional processes. The experimental specimens were manufactured with T42 HSS powders (59 vol%) and polymer (41 vol%). The metal powders were prealloyed water-atomised T42 HSS. The green parts were solvent debinded in normal n-Hexane at $60^{\circ}C$ for 24 hours and thermal debinded at $N_2-H_2$ mixed gas atmosphere for 14 hours. Specimens were sintered in $N_2$, $H_2$ gas atmosphere and vacuum condition between 1200 and $1320^{\circ}C$. In result, polymer degradation temperatures about optimum conditions were found at $250^{\circ}C$ and $480^{\circ}C$. After sintering at $N_2$ gas atmosphere, maximum hardness of 310Hv was observed at $1280^{\circ}C$. Fine and well dispersed carbide were observed at this condition. But relative density was under 90%. When sintering at $H_2$ gas atmosphere, relative density was observed to 94.5% at $1200^{\circ}C$. However, the low hardness was obtained due to decarbonization by hydrogen. In case of sintering at the vacuum of $10^{-5}$ torr at temperature of $1240^{\circ}C$, full density and 550Hv hardness were obtained without precipitation of MC and $M_6C$ in grain boundary.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.339-347
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• 2014

This study investigated the classification of olive oils that are mainly distributed in Korea via imports. The fatty acid contents, degree of color, pigments, anti-oxidants, and sterol contents are analyzed on the different types of olive oil as follows: 10 kinds of extra virgin olive oil, 5 kinds of pure olive oil, and 5 kinds of refined olive-pomace oil. As a result of fatty acid analysis, the majority of oleic acid ($C_{18:1}$) and palmitic acid ($C_{16:0}$), and minority of linoleic acid ($C_{18:2}$) and stearic acid ($C_{18:0}$) were detected without any significant differences between the grades of olive oils. The UV spectrum is related to the ${\Delta}K$, and it is a part of the analysis factor for the purity and degree of degradation of the oil. Extra virgin olive oil had ${\Delta}K$ of almost 0, pure olive oil had 0.07~0.12, and refined olive-pomace oil had 0.1~0.13. These differed from extra virgin oil, and the pure or pomace oil ${\Delta}K$ had a confirmed distinct difference. The color degrees of chlorophyll with a low $L^*$ value and $(-)a^*$ (green) and carotenoid with $(+)b^*$ (yellow) were confirmed to have correlation between extra virgin and other olive oils. To compare chlorophyll and carotenoid as natural pigment in olive oils, 417 nm and the ratio of the absorbance at 480 nm (417/480) was calculated at 1.62 of extra virgin, 1.85 of pure olive oil, and 3.32 of refined olive-pomace oil. Therefore, it will be possible to distinguish when the extra virgin or pure olive oil are mixed with olive-pomace oil. The total amount of tocopherol, an anti-oxidant, were 19.06 in extra virgin, 10.91 in pure olive oil, and 27.88 in refined olive-pomace oil. The high content of tocopherol in pomace oil caused recovery of solvent extraction from olive pulp. Thus, extra virgin oil and pure olive oil were distinguished by olive-pomace oil. Polyphenol compounds in extra virgin olive oil measured high only in ferulic acid with 0.543 mg/kg, caffeic acid with 0.393 mg/kg, and other vanillic acid, vanillin, and p-coumaric acid had similar amount of 0.3 mg/kg. All grade of olive oils had the highest ${\beta}$-sitosterol content. Af (Authenticity factor) value were estimated with campesterol and stigmasterol content ratio (%). Af value was 19.2 in extra virgin olive oil, 17.1 in pure olive oil, 16.9 in refined olive-pomace oil, which were distinctive from sunflower oil with 3.7, corn oil with 2.4, and soybean oil with 2.0. It can provide important indicator of olive oil adulteration with other cheap vegetable oils. The results of this study can be used as a database for the classification of olive oil grade and distinguishing between the different types of oils.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.51-57
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• 2016

In this study, we synthesized reactive surfactant which have functional radical group for effective chemical reaction. Reactive surfactant have been synthesized using synthesis of polyoxyethylene lauryl ether(POE 23) which is nonionic surfactant and methacrylic acid, acrylic acid. benzene was used as the solvent, p-TsOH was used as the catalyst. synthesized surfactant was confirmed by FT-IR, $^1H$-NMR spectra, and elemental analysis. Evaluation of physical properties was measured HLB, cloud point, surface tension, the critical micelle concentration, emulsifying power. HLB number was evaluated 11.62 to 12.09 range. The Critical Micelle Concentration(cmc) values evaluated was $1{\times}10^{-4}{\sim}5{\times}10^{-4}mol/L$ by surface tension method. The cloud point was $35^{\circ}C$, $39^{\circ}C$ each. The emulsifymvcqa ing properties of the synthesized surfactants was lower than polyoxyethylene lauryl ether. In addition, soybean oil was better than benzene. The experimental results confirmed the ester bond, the yield of 93.27%, 94.49% was found.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.983-992
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• 2015

This study investigated the quality characteristics and biological activities, such as antioxidant, whitening, anti-diabetes, and anti-inflammatory activities, of yellow garlic, by simplify processing time and manufacturing process compared with black garlic. Extracts were prepared various ratios of water and ethanol solvent [water : ethanol (v/v)=100:0, 70:30, 50:50, 30:70, 0:100] from yellow garlic. Alliin content of yellow garlic showed no difference compared with fresh garlic, whereas S-allyl cysteine content of yellow garlic was higher than that of fresh garlic. Alliin content of yellow garlic extracts increased in an ethanol concentration-dependent manner. Total phenol and flavonoid contents were highest in 100% ethanol extract. DPPH and ABTS radical scavenging abilities did not show significant differences among 0~70% ethanol extracts, whereas 100% ethanol extract showed the highest contents of 93.45% and 91.46%, respectively. Tyrosinase and ${\alpha}$-glucosidase inhibitory activities were also highest in 100% ethanol extract, but did not show significant differences among the extract solvents. Water and ethanol extracts from yellow garlic showed anti-inflammatory effects by modulating production of NO and cytokines at a concentration of $100{\mu}g/mL$. We suggest that yellow garlic has antioxidant, whitening, anti-diabetes, and anti-inflammatory activities and can be used as a functional material similar to black garlic.