• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.451-460
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• 2017

This study optimized the extraction of antioxidants from Gugija (Lycium chinensis Mill). To determine operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), response surface methodology was applied to monitor yield, anthocyanins, flavonoids and DPPH radical scavenging activity. Coefficients of determinations ($R^2$) of the models were range of 0.8645~0.9859 (p<0.01~0.1) in dependant parameters. Yield of Gugija extracts was maximized 23.12% in extraction conditions of 4.22 h at 8.25% ethanol. Anthocyanins was maximized 1.43 (OD in 530 nm) in extraction conditions of 3.06 h at 79.98% ethanol. Flavonoids was maximized $3,100{\mu}g/100g$ in extraction conditions of 3.37 h at 67.02% ethanol. DPPH radical scavenging activity was maximized 96.93% in extraction conditions of 1.67 h at 69.81% ethanol. Optimum extraction conditions (2.5 h extraction at 70% ethanol) were obtained by superimposing the contour maps with regard to anthocyanins, flavonoids and DPPH radical scavenging activity of Gugija. Maximum values of anthocyanins, flavonoids and DPPH radical scavenging activity in optimum extraction condition were 1.0080 (OD in 530 nm), $3,145{\mu}g/100g$, 96.96%, respectively. But values of anthocyanins, flavonoids and DPPH radical scavenging activity in water extraction condition (1 h at water) were 0.4652 (OD in 530 nm), $1,633{\mu}g/100g$, 86.98%, respectively.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.367-371
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• 2013

The half maximal inhibitory concentration ($IC_{50}$) values and trolox equivalent antioxidant capacity (TEAC) values were calculated by a 2,2'-diphenylpicrylhydrazyl (DPPH) assay and a 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^{+{\cdot}}$) assay, in order to determine the antioxidative activities of the compounds. On the basis of the DPPH assay, quercetin had the strongest antioxidative potential of the flavonoids, followed in order by fisetin, 7,8-dihydroxyflavone, morin and kaempferol. Quercetin, fisetin and 7,8-dihydroxyflavone had higher antioxidant potentials than butyl hydroxyl anisole. Quercetin had the highest TEAC value amongst the flavonoids and isoflavonoids, followed in order by 3-hydroxyflavone, fisetin, 7,8-dihydroxyflavone and morin. Comparatively, isoflavonoids were found to have significantly weaker antioxidative potential than the flavonoids.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.111-116
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• 2020

Total polyphenol contents, flavonoid contents, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities of ethanol extracts of 20 herbal plants (sage, turmeric, mace, bayleaf, fenugreek, oregano, blackpepper, whitepepper, clove, marjoram, cinnamon, coriander, basil, dillseed, mustard, cadamon, thyme, celery, rosemary, cumin) were analyzed for the screening of high flavonoid-containing plant resource. Thyme extract, showing the highest flavonoid content and a high degree of antioxidant activity, was selected as a bioactive cosmetic material. The total polyphenols and flavonoids contents of thyme extracts were measured as 6.90 mg chlorogenic acid equivalent (CAE)/100 g and 1.71 mg naringin equivalent (NE)/100 g, respectively, and DPPH radical scavenging activities was 90%. Among the tested organic solvents, hexane gave the highest extraction yield. Thus hexane was selected as the most suitable solvent for the extraction of thyme. Response surface method was used to obtain optimized extraction conditions for thyme: reaction temperature of 35.9 ℃, raw material to hexane ratio of 1.63:25 (w/v), and reaction time of 192 min. These predicted extraction conditions was validated by a total flavonoid extraction experiment showing a value equivalent to 96.3% of the predicted total flavonoid content. It is expected that the optimized solvent extraction conditions could be used for the production of flavonoid using thyme.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.337-342
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• 2012

The purpose of this study was to investigate total polyphenols, total flavonoid, and DPPH radical scavenging activity in 26 species of Korean natural plants and 14 species of medicinal plant extracts. The plant containing the highest total polyphenols and total flavonoids were Plantago asiatica, and Lespedeza cuneata G. Don, respectively. The content of polyphenols and flavonoids in natural plants was the highest in Lespedeza cuneata G. Don, which also demonstrated high DPPH radical scavenging activity. In medicinal plant extract, Saururus chinensis (Lour.) Baill and Artemisiae Asiaticae Herba had the highest level of total polyphenols (194.60 and 203.92 mg/g extract, respectively) and DPPH radical scavenging activity. Diospyros kaki Thunb and Dryopteris crassirhizoma did not contain high levels of total polyphenols (112.98, 121.46 mg/g extract, respectively) and flavonoids (46.10, 58.69 mg/g extract respectively), but DPPH radical scavenging activity was relatively high. Further study regarding plants that exhibit higher total polyphenols, total flavonoid, and DPPH radical scavenging activity is needed.

• Journal of Life Science
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• v.27 no.4
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• pp.476-481
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• 2017

Polyphenols are secondary metabolites produced by higher plants and have been used as antiallergic, anticancer, antihypertensive, antiinflammatory, antimicrobial and antioxidant agents. They are generally divided into flavonoids and non-flavonoids. The antimicrobial activity of flavonoids are stronger than that of non-flavonoids. The skeleton structures of flavonoids possessing antimicrobial activity are chalcone, flavan-3-ol (catechin), flavanone, flavone, flavonol and proanthocyanidin. The flavonols are shown antibacterial activity against several gram-positive bacteria (Actinomyces naeslundii, Lactobacillus acidophilus and Staphylococcus aureus) and gram-negative bacteria (Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella melaninogenica and Prevotella oralis). Among of non-flavonoids, caffeic acids, ferulic acids and gallic acids showed antimicrobial activity against gram-positive (Listeria monocytogenes and S. aureus) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). These are found to be more efficient against the E. coli, L. monocytogenes, P. aeruginosa and S. aureus than antibiotics such as gentamicin and streptomycin. The kaempferol and quercetin showed synergistic effect with ciprofloxacin and rifampicin against S. aureus and methicillin resistant S. aureus (MRSA). Epigallocatechin gallate (EGCG) acts synergistically with various ${\beta}-lactam$ antibiotics against MRSA. In particular, the epicatechin, epigallocatechin (EGC), EGCG and gallocatechin gallate from Korean green tea has antibacterial activity against MRSA clinical isolates and the combination of tea polyphenols and oxacillin was synergistic for all the clinical MRSA isolates.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1240-1246
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• 2006

Generally, there are two types of main factors to affect output power quality of a auxiliary power supply an EMU(electric multiple unit). One is a voltage flicker by amplitude modulation of short time and air compressors. The other is repetitive motion of large capacity motor such as air compressors, HVAC unit etc. in main factors. This paper compared two kinds of fluorescent lamp, 32W (after remodeling interior) and 40W(before remodeling interior) and measured the light output varying input power(AC220V) for a flicker phenomenon related power supply of lamps in EMU. Also, we analyzed a flicker considering EMU operating time and density in order to grasp main factors of a load change to cause a voltage change. As a results of test, a 40W fluorescent lamp was more insensitive with 20.26% degree an eye recognition degree sides about changes of the input power and lower with 19.9% voltage side generating flicker compare with fluorescent lamp 32W. Also, we confirmed the fact which the fluorescent lamp flicker was generated by varying fluorescent lamp output voltage when the commercial EMU was in high driving density and at the busy time. Additionally, we confirmed the frequency band which an EMU passenger could feel sensitively blinking of a fluorescent lamp was visually $8Hz{\sim}15Hz$.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.434-440
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• 2012

A placebo-controlled double-blind ingestion study of a beauty supplement containing rice-derived ceramide was performed. Thirty three subjects who always tended to have rough skin due to dryness participated in the study. Dermatological diagnosis by physicians showed that the supplement significantly improved dryness and itching of the skin. On measurement of water content in the skin, the supplement was shown to significantly increase water content in the skin. On microscopic three-dimensional analysis of the epidermis, the supplement was shown to improve smoothness, exfoliation, and short-term ingestion of the supplement containing rice derived ceramide, which is very effective as skin beautifying food.

• Resources Recycling
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• v.26 no.1
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• pp.69-77
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• 2017

Used small household appliances(small e-waste) consists of a variety of complex materials and components. The small e-waste is mainly composed of plastics and an important potential source of waste plastic. The black plastics, particularly are very difficult to separate by resin type and therefore these are mainly recycled in the form of a mixtures. In the present study, the sorting technologies such as gravity and electro static separation, near-infrared ray(NIR) and IR/Raman optical sorting separation on mixture of black plastics were analyzed and their limitations on sorting process were also investigated. The Laser Induced Breakdown Spectroscopy(LIBS) spectrum of each black plastics was used for identification of black plastics by resin type, and after analyzing the normalization operation, Principal Component Analysis(PCA) was carried out. The spectrum data was optimized through PCA process. In order to improve the identification accuracy and sorting efficiency of black plastics, it is necessary to design a classifier with high efficiency and to improve the performance and reliability of the classifier by applying the field of intelligent algorithms.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1094-1103
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• 2017

The purpose of this study was to measure the bioactivity and antioxidant activity of seed from Gardenia jasminoides Ellis fructus (GJE). We determined tannin content ($1.517{\pm}0.003mg\;CE/g$, mg of catechin equivalents). The extraction yields of the GJE seed solvent were distilled water (DW) 36.61%, 70% methanol 30.10% and ethyl acetate (EA) 20.40%. The antioxidant activities of the extracts were significantly increased (0.2, 0.4, 0.6 mg/mL). Flavonoid contents (mg QE/g, mg of quercetin equivalents) were observed in the order of 70% methanol (0.799), DW (0.565) and EA (0.117). Antioxidant activities (DPPH, OH, ferrous ion-chelating capacity) were similar to the flavonoid content of each solvent. But ABTS scavenging activity and SOD like ability of DW extract were higher than 70% methanol extract. Comparing the yield and the antioxidant activity of each solvent of GJE seed, it seems to be preferable to use DW and 70% methanol solvent for extraction. As a result of this experiment, it has high antioxidant activity and physiological activity, which is expected to be highly valuable as a functional food and a natural antioxidant.

• 프린팅코리아
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• v.9 no.3
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• pp.66-68
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• 2010

에스코아트워크(대표 이도상)는 상업인쇄와 패키징 분야에서 다양한 솔루션을 제공하는 글로벌 기업인 에스코아트워크의 한국지사이다. 지난해 새 대표 취임과 함께 사무실도 충무로에 새롭게 마련, 지금까지의 조용한 활동에서 벗어나 적극적인 동반자로 새로운 변신을 도모하고 있다. 에스코아트워크가 추구하는 핵심적인 가치인 '비즈니스플로'는 기존 기업들이 말하는 워크플로 솔루션보다 보다 확장되고 포괄적인 의미를 갖는 것으로 알려져 있다. 즉, 첨단 IT기술과 MIS 및 ERP시스템을 도입해 디자인기획에서 납품에 이르기까지 인쇄에 관련된 모든 작업과정에 관련된 솔루션을 지원한다는 것이다. 단순한 하드웨어 판매 또는 소프트웨어 공급이 아니라 이 두 가지를 연계하는 것은 물론이며 하드웨어 및 소프트웨어 관리 서비스까지 포괄하는 것을 포함하고 있다.