• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.59-71
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• 2018

Purpose: Cellulose nanocrystals (CNCs) are natural polymers that have been promoted as a next generation of new, sustainable materials. CNCs are invaluable as reinforcing materials for composites because they can impart improved mechanical, chemical, and thermal properties and they are biodegradable. The purpose of this review is to provide researchers with information that can assist in the application of CNCs extracted from waste agricultural byproducts (e.g. rice husks, corncobs, pineapple leaves). Methods & Results: This paper presents the unique characteristics of CNCs based on agricultural byproducts, and lists processing methods for manufacturing CNCs from agricultural byproducts. Various mechanical treatments (microfluidization and homogenization) and chemical treatments (alkali treatment, bleaching and hydrolysis) can be performed in order to generate nanocellulose. CNC-based composite properties and various applications are also discussed. Conclusions: CNC-based composites from agricultural byproducts can be combined to meet end-use applications such as sensors, batteries, films, food packaging, and 3D printing by utilizing their properties. The review discusses applications in food engineering, biological engineering, and cellulose-based hydrogels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.468-475
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• 2009

This study was conducted to examine the bleaching of an anti-inflammatory agent containing Undaria pinnatifida extract (AIAU). Brown-colored AIAU was irradiated with $^{60}CO$ gamma rays at doses ranging from 10-200 kGy. Discoloring of the anti-inflammatory agent was achieved by gamma irradiation, with significantly removal by 50 kGy irradiation. The main active compound of the agent consisted of 4% U. pinnatifida extract, which inhibited inflammatory symptoms in mouse ear edema by 93%. There was no change in effects against edema, erythema, blood flow and radical scavenging activity by irradiation.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.115-120
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• 1997

To investigate the cognition of labeling system and its problems, problems in laundry, and consumer's dissatisfaction and to decrease problems in management of clothing products, total 476 subjects were surveyed in Taejon. The major results were as follows ; 1. The cognition of labeling system was understood by 93.1% of respondents, and 72.9% of them prefer to recognized labeling by figures and letters than by either of them. Most of respondents got the knowledge of labeling system from school. The most frequently experienced mislabeling was the label for management. 2. In cleaning, 60.4% of respondents made their decisions of the laundry method after seeing labeling system. When the label recommanded either of hand washing or dry cleaning, they usually laundered with hand washing after a few times of dry cleaning. The first consideration factor for laundry was fiber composition of textiles. 3. About 70% of respondents understood ironing, laundry, and drying mark on labeling system, and 53.8% understood fiber composition and bleaching. 4. More than 90% of respondents experienced dissatisfaction in handling clothing products. The reason of dissatisfaction was deformation and decoloring after laundry. Most of respondents experienced change of tactile sensation, too.

• Journal of the Korean Applied Science and Technology
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• v.15 no.4
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• pp.63-69
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• 1998

The beeswax sample was collected from the beehives, isolated and then refined. The first step of producing beeswax was to separate honey from beehives. The beehives which were cut put in hot water. The upper layer was crude beeswax, which was treated with phosphoric acid. The crude beeswax was purified through the bleaching. The objectives of this study are to identify headspace volatile compounds and to know the contents of ${\alpha}$-carotenes and ${\beta}$-carotenes of korean beeswax. Headspace volatile compounds of Korean beeswax were measured by using the combination of dynamic headspace sampler (DS 5000, Donam System Inc.), gas chromatography and mass selective detector (HP5890 & 5971, Hewlett Packard). Seventy five compounds identified from about 100 peaks by analyzing the purified beeswax were 60 hydrocarbons, 8 carbonyls, 4 essential oils, 3 esters. Carotenes of Korean beeswax were analyzed by using High Performance Liquid Chromatography (Waters Inc.). As A result, the content of ${\alpha}$-carotenes and ${\beta}$-carotenes were 0.07ppm, 0.011ppm individually.

• Journal of the Korean Applied Science and Technology
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• v.15 no.4
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• pp.87-93
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• 1998

In spite of various applications of chitin derivatives from waste marine sources, commercial use of chitin has been limited due to resistance to chemicals and the absense of proper solvents. We prepared chitin through decalcification, bleaching and deproteination from protunus trituberculatus shells by the application of Hackman's method. Structural and chemical properties of chitin were investigated to have proper specific surface area and particle size by IR, BET and PSA. The amount of absorbed water of chitin reached equilibrium by stirring about 15 minutes. The amount of absored water of the prepared chitin were large than the commercial chitin. When prepared chitin tested on dyeing wastewater, they showed better treatment efficiency in COD, suspended solid, and color tests than the commercial chitin. The adsorption capacity increased with decreasing particle size for the prepared chitin. Treatment efficiency for color was increased as the sitirring rate increased. Results show the possibility of the prepared chitin from waste marine sources as a treatment system for dyeing wastewater.

• Journal of radiological science and technology
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• v.21 no.2
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• pp.53-56
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• 1998

Highly sensitive $CaSO_4:Tm$ TLD is fabricated and their trap parameters are determined. The glow curve of $CaSO_4:Tm$ consists of three glow peaks and these peaks are isolated by the thermal bleaching method. The isolated glow peaks are fitted by a least squares method. The activation energies are 0.68, 0.82 and 1.03 eV. The frequency factors are $8.09{\times}10^8,\;9.14{\times}10^8$ and $1.03{\times}10^9/s$, and the kinetic orders are 1.37, 1.54 and 1.68, respectively. The optimum temperature range of the main peak for radiation dosimetry is between 220 and $290^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.47 no.2
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• pp.189-194
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• 2010

Compared with organic fluorophores, semiconductor quantum dots (QDs) have the better properties such as photostability, narrow emission spectra coupled to tunable photoluminescent emissions and exceptional resistance to both photo bleaching and chemical degradation. In this work, CdSe/ZnS QDs nanobeads were prepared by the incorporation of CdSe/ZnS QDs with mesoporous silica to use as the optical probe for detecting toxic and bio- materials with high sensitivity, CdSe/ZnS core/shell QDs were synthesized from the precursors such as CdO and zinc stearate with the lower toxicity than pyrotic precursors. The QD-nanobeads were characterized by transmission electron microscopy, FL microscopy, UV-Vis and PL spectroscopy, respectively.

• Journal of Environmental Science International
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• v.23 no.7
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• pp.1233-1239
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• 2014

Watermelon (Citrullus vulgaris L.) is a summer fruit typical to help fatigue systemic absorption is getting better. The goal of this study is to screen antioxidant activity to ensure the possibility as a functional material for exocarp of watermelon. Watermelon was extracted with 70% methanol, 70% ethanol, chloroform:methanol (CM, 2:1, v/v). Total phenol contents were 12.01 mg/g, 8.89 mg/g, 3.53 mg/g in the 70% methanol, 70% ethanol, CM, in that order, respectively. Total flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power (FRAP), ${\beta}$-carotene bleaching assay were 70% methanol extract remarkably higher than the other extracts. And these results showed the same trend of total phenol content. From the above results shows that watermelon was effective on the antioxidative activity.

• Natural Product Sciences
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• v.24 no.2
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• pp.125-131
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• 2018

Berries and branches essential oil of Juniperus phoenicea were obtained by electromagnetic induction heating assisted extraction and by hydrodistillation with a yield varied from ($1.2{\pm}0.3$ to $2.4{\pm}0.7%$) and from ($0.6{\pm}0.1%$ to $1.1{\pm}0.1%$), respectively. forty eight compounds were identified representing (97.2 - 99.7%) of the oil. ${\alpha}$-Pinene (40.3 - 67.8%) and ${\delta}$-3-carene (13.5 - 26.8%) were the main compounds in berries and branches essential oils. Antioxidant activity was evaluated by three means: inhibition of 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical, reducing power and ${\beta}$-Carotene/linoleic acid bleaching. The antioxidant activity of essential oils showed $IC_{50}$ ranging from $67.6{\pm}1.02{\mu}g/mL$ to $131.5{\pm}0.8{\mu}g/mL$ for berries and from $98{\pm}1.25{\mu}g/mL$ to $166.8{\pm}0.29{\mu}g/mL$ for the branches. Berries oil show more potent antioxidant activity compared to branches. This result is supported by the three methods investigated in this work.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.720-725
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• 2012

Sodium hypochlorite is used worldwide as a water disinfectant and in bleaching agent. Sodium hypochlorite applied to water initially undergoes hydrolysis to form free chlorine consisting of hypochlorous acid(HOCl) and hypochlorite ion($OCl^-$). For free chlorine determination, an electrochemical method is simple due to the electroactivity of free chlorine; it measures current and is free of most reagents. Amperometric free chlorine sensor has been developed with gold (Au)-based electrode. The 3-electrode free chlorine sensor whose working and counter electrodes were Pt exhibited excellent response to HClO at +400mV vs. Ag/AgCl/sat. KCl. In addition, the use of a pH error correction algorithm provided a reliable measurement of residual free chlorine in water sample without any pretreatment in the normal pH range(pH 6~8) of municipal water supply. The free chlorine sensor installed in on-line monitoring system could be used to continually monitor the level of residual free chlorine in real samples.