• New & Renewable Energy
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• v.5 no.2
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• pp.9-14
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• 2009

Automobile Shredder Residue (ASR) is very appropriate in a gasification melting system. Gasification melting system, because of high reaction temperature over than $1,350^{\circ}C$, can reduce harmful materials. To use the gasification processes for hydrogen production, the high concentration of CO in syngas must be converted into hydrogen gas by using water gas shift reaction. In this study, the characteristics of shift reaction of the high temperature catalyst (KATALCO 71-5M) and the low temperature catalyst (KATALCO 83-3X) in the fixed - bed reactor has been determined by using simulation gas which is equal with the syngas composition of gasification melting process. The carbon monoxide composition has been decreased as the WGS reaction temperature has increased. And the occurrence quantity of the hydrogen and the carbon dioxide increased. When using the high temperature catalyst, the carbon monoxide conversion ratio ($1-CO_{out}/CO_{in}$) rose up to 95.8 from 55.6. Compared with average conversion ratio from the identical synthesis gas composition, the low temperature catalyst was better than the high temperature catalyst.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1265-1274
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• 2012

This study was conducted to investigate the extraction characteristics including total polyphenol compound content (TPC) and the antioxidative effect of Rumex crispus root extract on commercial corn oil. Extraction yield was increased with extraction temperature but decreased with extraction ratio. No significant differences in aromatics content were found among the extracts prepared with various extraction conditions; extraction ratio, extraction temperature, extraction pH and composition of extractant. Total flavonoid content of the extract was increased with extraction temperature and extraction pH, and highest value of it was found when extractant composition of ethanol in water was 75%. Total polyphenol compound content (TPC) of the extract with 10 fold extraction ratio showed the highest value, but no significant difference in TPC was found with extraction temperature. Reducing power and DPPH (${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging ability (RSA) of the extract in spectrophotometric absorbance were decreased with extraction ratio but increased with extraction temperature and showed 63.1%~98.4% and 67.6%~86.7% of those of ascorbic acid in reducing power and DPPH RSA, respectively. The antioxidative effects of the extract on corn oil were 84.8~93.0% of that of commercial butylated hydroxytoluene, the antioxidant index value was highest when the ethanol composition to water in extractant was equal ratio.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.606-611
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• 2006

The chemical composition of Smilax china leaves and the quality characteristics of seolgitteok (rice cake) prepared with a water extract of these leaves were evaluated. Sucrose, glucose, maltose, and fructose were found as free sugars in the leaves, while the main fatty acids were stearic and palmitic acids. Glutamic acid and potassium were found at the highest levels among the analyzed amino acids and minerals in the leaves, respectively. On a fresh weight basis, the content of total phenolics and condensed tannin was 1.26 and 0.74%, respectively. As the amount of S. china leaf extract increased, the lightness of seolgitteok significantly decreased (p<0.001) in the rice cake, while redness and yellowness of the cake increased. Texture evaluation showed that springiness, strength, and cohesiveness were higher in rice cakes prepared with 2% S. china leaf extract compared to rice cakes made with 1% extract. At the beginning of the storage period ($20^{\circ}C$), there were no significant differences in viable aerobic cell and mold counts among rice cakes, but after four days in storage, a significant reduction in microorganisms was observed in rice cakes prepared with increasing amounts of leaf extract. On sensory evaluation, rice cakes made with 1% water extract from S. china leaves scored the highest on flavor, taste, texture, and overall acceptability.

• The Korean Journal of Food And Nutrition
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• v.35 no.4
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• pp.268-275
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• 2022

The purpose of this study was to confirm the possibility of using Korean purple yam (Dioscorea alata) as proximate composition, material, and antioxidant activity. In the proximate composition of the freeze-dried purple yam powder, the carbohydrate content was the highest at 86.67%, and in minerals, potassium showed the highest content at 1,765.69 mg/100 g. To study the antioxidant activity of purple yam, distilled water and 70% ethanol were used as extraction solvents. The total polyphenol, total flavonoid, and total anthocyanin contents were 1.3~1.6 times higher in 70% ethanol extract, than in the distilled water extract. As a result of ORAC, DPPH and ABTS radical scavenging activity, SOD activity, and reducing power, the 70% ethanol extract showed higher antioxidant activity than the distilled water extract in all results. As a result of freeze-drying purple yam and measuring antioxidant activity by extraction solvents, it is concluded that purple yam can contribute to the food industry as a natural antioxidant and health functional material.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.17-26
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• 1996

This research was accomplished to evaluate possibility of using paper sludge for the raw materials of wood based panel products. The experimental panels were manufactured by four mixed ratios, the proportion of paper sludge to wood particle: 20:80, 30:70, 40:60, 50:50% (oven dry weight basis) and by three composition types, sludge-particle mixed board, three layered sludge-particle board and three layered particle board. They were tested mechanical (bending strength and internal bond) and physical properties (water absorption, thickness swelling and linear expansion). From the results they were shown that bending strength of mixed and three layered sludge-particle board were decreased with increasing of composition ratios of sludge. And the mechanical and physical properties of the boards of three layered composition types have superior to those of mixed composition type. Although composition ratios of sludge increased, the internal bond strength and dimensional stability of sludge-particle board not decreased quantitatively. We concluded that the mechanical and physical properties of three layered sludge-particle board were similar w those of three layered particle-board (control) made by our laboratory design. Therefore, it was recognized that paper sludge can be used as potential raw material in particle-board manufacturing industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.39-54
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• 2005

Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

• Computers and Concrete
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• v.32 no.1
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• pp.45-60
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• 2023

Concrete in water environment is easily subjected to the attack of leaching, which causes its mechanical reduction and durability deterioration, and the key to improving the leaching resistance of concrete is to increase the compaction of its microstructure formed by the curing. This paper performs a numerical investigation on the intrinsic relationship between microstructures formed by the hydration of cement and slag and leaching resistance of concrete in water environment. Firstly, a shrinking-core hydration model of blended cement and slag is presented, in which the interaction of hydration process of cement and slag is considered and the microstructure composition is characterized by the hydration products, solution composition and pore structure. Secondly, based on Fick's law and mass conservation law, a leaching model of hardened paste is proposed, in which the multi-species ionic diffusion equation and modified Gérard model are established, and the model is numerically solved by applying the finite difference method. Finally, two models are combined by microstructure composition to form an integrated curing-leaching model, and it is used to investigate the relationship between microstructure composition and leaching resistance of slag-blended cement pastes.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.100-102
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• 1991

The features of waste water from by-product silk treatment of silk reeling process were investigated and the lipid extracted from waste water was analysed. The COD of waste water from by-product silk treatment was at the level of 605 mgO/$\ell$ Total Dissolved Solid Particles 2,335mg/$\ell$and Total Suspended Solid Particles 2,123mg/$\ell$. The lipid extracted from the waste water from by-product silk treatment was composed of triglyceride 76.8%, free fatty acids 12.5%, diglyceride 5.7% and free sterol 5.0%. In fatty acid composition of lipid, the content of loeic acid, linoleic and linolenic acid was 64.93%, whereas that of palmitic acid was 29.39% and stearic acid 4.93%.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.41-46
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• 2001

Trihalomethane(THMs) levels in drinking tap water, indoor swimming pool water and industrial effluent in Kunsan area were surveyed in this study. During experimental period, the monthly averages of THMs in drinking tap water from Keumkang wide-area supply ranged from 15$\mu\textrm{g}$/ι/to 50 $\mu\textrm{g}$ showing the highest level in summer. 3 indoor swimming pools showed the monthly average levels of THMs formation ranging from 8$\mu\textrm{g}$/ι/to 20$\mu\textrm{g}$/ι and the pool under public management seemed to maintain its water quality more stable than those under private management THMs concentrations in the effluents. discharged from 10 manufacturing companies, ranged from N.D. to 95$\mu\textrm{g}$/ι and it was estimated that the overall THMs level discharged front those manufacturing companies is not high, reflecting the traces recorded for most effluents. The composition ratios of individual THMs for industrial effluents showed a difference from those for drinking water and swimming pool water, along with their wide variations according to the company and relatively high composition ratios of Br substituents.

• Journal of Environmental Science International
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• v.24 no.6
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• pp.785-792
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• 2015

This study investigates weekday/weekend characteristics of $PM_{10}$ concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO_4{^{2-}}$ to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. $[NO_3{^-}/SO_4{^{2-}}]$ ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and $Cl^-/Na^+$ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.