• Polymer(Korea)
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• v.32 no.4
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• pp.322-327
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• 2008

In this study, a multi-layered pellet was composed of a seed layer including a water-swellable agent and a drug layer containing doxazosin as a model drug, a porous membrane and a castor oil layer to control drug release. The pellet is prepared by a fluidized bed coating method. To confirm drug release from polymer blending in multi-layered pellet system, it is prepared by containing different ratio such as hydroxypropylmethylcellulose (HPMC) : ethyl cellulose (EC) in drug layer and cellulose acetate(CA) : Eudragit RS in membrane. Also, to confirm the effect of oil in drug release, castor oil is coated. As a result, we observed regularly spherical pellet with diameter of $1500{\mu}m$. Release pattern of drug is confirmed by dissolution tester in aqueous media. The more the ratio of EC in drug layer, CA in membrane, and castor oil layer in pellet, the less the drug release is observed. Formation and the amount of pores in membrane is observed by SEM.

• Journal of the Korean GEO-environmental Society
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• v.13 no.1
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• pp.45-51
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• 2012

This article aims to find method to mix a harmless hardening agent and soil generated during construction to make paving materials. The main purpose of this research is to get rid of the harmfulness(Chromium (VI), etc.) of cement which has been generally and frequently used as a hardening agent and strengthen it so that it can be used for the general foundation solidification and stabilization of civil engineering/construction structures such as dredging soil treatment, marine structure foundation treatment, surface soil stabilization, and river bank erosion prevention. NSS(Natural Stabilizer Soil) used for this study takes as its chief ingredient the mixture of lime and staple fibers extracted from natural fibers. It increases the shearing strength of soil that it improves the support and durability of the foundation and prevents flooding and frost as well. The pH measured to know its eco-friendliness was 6.67~7.15, and according to the migration testing, only Pb and CN were lower than the standards, so it can be said that NSS has almost no harmful components in it. According to the result of uniaxial strength testing, when the mixture ratio of weathered soil to NSS was 6%, about 1,850kpa strength was expressed. And according to the result of CBR. testing to figure out its appropriateness as a paving material, the CBR of the foundation was 4%~6%. But when the mixture ratio of NSS is over 6%, the water immersion CBR. is over 100%; thus, it is expected that it will show great utility as a paving material.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.613-620
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• 2012

This study was carried out to investigate changes in nutrient composition and fermentation properties in abalone mul-kimchi using dried pollack stock (AMKP) and licorice stock (AMKL) during storage at $4^{\circ}C$ for 35 days. The levels of moisture (88.37-90.94%) and crude ash (2%) did not differ much between AMKP and AMKL during the 35 days of storage. But crude protein and crude lipid levels decreased gradually until 21 days of storage. AMKP and AMKL fermentation during 21 days led to a decrease in pH, increased acidity, and the highest Leuconostoc sp. count. AMKP and AMKL showed acidity of 0.50% at pH 4.30, when the kimchi samples were ripened properly. Glutamic acid showed the highest content in AMKP and AMKL, and hydroxypoline was the most abundant of all free amino acids. We have provided basic data for commodification research on abalone mul-kimchi.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.211-216
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• 2008

The artificial lightweight aggregate (ALA) was manufactured in a rotary kiln at $1125^{\circ}C$ using green body formed by pelletizing the batch powder composing of coal bottom ash (CBA) produced from power plant, clay and dredged soil (DS). The TCLP (Toxicity characteristic leaching procedure) results showed that the dissolution concentration of heavy metal ions of ALA fabricated in this study was below the limitation defined by the enforcement regulations of wastes management law in Korea. The ALA containing 60$\sim$70 wt% CBA had a bulk density of 1.45$\sim$1.49 and a water absorption of 17.2$\sim$18.5 %. The impact values for oven-dry state and saturated-surface dry state of ALA were 27.4$\pm$1.3 and 23.4$\pm$2.6 % respectively. The 28-days compressive strength of concrete made with various ALA was $22.7\sim27.8 N/mm^2$. The slump of concrete with ALA containing CBA 60 and 70 wt% were 7.9 and 14.3 cm respectively. The unit weight of concrete made with any ALA fabricated in this study was satisfied with the standard specifications of lightweight concrete for the civil engineering and construction presented by Korea as below $1.84 ton/m^3$.

• Journal of Life Science
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• v.28 no.3
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• pp.300-306
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• 2018

Lysozymes are innate immune factors that play a critical role in the defense against pathogens in various invertebrate animals including spoon worms. In this study, an invertebrate-type lysozyme was isolated from the body wall of spoon worm, Urechis unicinctus. The acidified body wall extract was partially separated using a Sep-Pak C18 cartridge. Among the fractions, the materials that were eluted with 60% methanol/0.1% trifluoroacetic acid showed the most potent antimicrobial activity against Bacillus subtilis KCTC 1021. A series of high performance liquid chromatography (HPLC) steps were then utilized to isolate a single antimicrobial absorbance peak. The molecular weight of the antimicrobial peak was approximated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), which was approximately 13 to 14 kDa. The partial primary structure of this antimicrobial protein that was analyzed, using LC-MS/MS, was CTGGRPPTCEDYAK (1611.69 Da). Homology search of these fourteen residues, using the National Center for Biotechnology Information Basic Local Alignment Search Tool (NCBI BLAST), revealed that the isolated protein was similar to the invertebrate-type lysozymes described in other animals. Then, the antimicrobial and lysozyme enzymatic (muramidase) activities of this protein were assessed. The isolated protein possessed antimicrobial activity and potent muramidase activity, which were comparable to those of hen egg white lysozyme. Therefore, the isolated protein was designated as Urechis unicinctus invertebrate-type lysozyme from the body wall, Uu-iLysb.

• Resources Recycling
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• v.25 no.4
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• pp.60-67
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• 2016

This study was conducted to establish the adsorption-desorption mechanism and the optimum condition of chromatographic operation for separations of heavy rare earth elements (Gd, Tb, Dy) using a p507-containing resin. By employing Langmuir and Freundlich isotherm together with pseudo first and second order kinetics, absorption-desorption reaction mechanism was investigated. Langmuir and Freundlich isotherm was applied under assumption that adsorption reaction occurs in form of monolayer, and because the result was identical to the assumption, now we know adsorption of heavy rare earth elements occurs in form of monolayer. Concerning the pseudo first and second order kinetic, the pseudo second order seemed to be more suitable to represent heavy rare earth element adsorption mechanism. By using the extraction chromatography to separate heavy rare earth elements, ${\alpha}^{Tb}_{Gd}=1.24$, and ${\alpha}^{Dy}_{Tb}=1.03$ were confirmed in eluent HCl 0.25 M which indicates almost perfect separations of three elements. Furthermore, as concentrations of eluent became higher, the resolution value decreased and the elution area got shortened.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.229-239
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• 2018

Currently, in Korea, a dry food simulant has not been designated for the migration testing of paper and board, food contact materials (FCMs) being used in dry foods, and foods heated at ultra-high temperature. Considering the diverse usage of FCMs, in order to secure reliable and confident safety evaluation and to overcome the non-trade barrier tariff in worldwide trade, migration testing methods of what should be more clearly defined for securing and overcoming. This article delves into the available literature on the use of $Tenax^{(R)}$ as a simulant for dry foods as well as its suitability and limitations, and examines the feasibility of its introduction into Korean FCMs regulation. Most experimental studies using $Tenax^{(R)}$ showed overestimated migration values when used in real foods, which reflects the potential of $Tenax^{(R)}$ as a dry food simulant in a worst-case scenario. However, more studies are required to optimize migration testing using $Tenax^{(R)}$ by standardizing the solvent type and the extraction method for surrogates of various FCMs and foods, and to resolve the potential drawbacks in the use of $Tenax^{(R)}$.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.48-55
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• 2007

A low-priced catalyst for pyrolysis of LDPE has been synthesized. Fly ash, which is waste material generated from coal-fired power plants was used as silica and alumna sources for solid acid catalyst. Amorphous silica-alumina catalysts (FSAs) were pre-pared by dissolution of silica and alumina from fly ash, followed by co-precipitation of the dissoluted ions. A series of LDPE pyrolysis were carried out in a thermogravimetric analyzer to investigate the effects of synthesis conditions such as NaOH/fly ash weight ratio and activation time one catalytic performance of FSAs. The physical properties of FSAs were examined and related to their catalytic performances. FSA(1.2-8) synthesized with NaOH/fly ash weight ratio of 1.2 and the activation time of 8 hours showed the best catalytic performance. The catalytic performance of FSA(1.2-8) was comparable with that of commercial catalysts and it was concluded that the FSA could be a good candidate for catalytic use in the recycling of waste polyolefins.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.166-172
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• 2005

In order to prepare liqueur of Acanthopanax koreanum, changes in major constituents by soaking below 0.5 cm size dried sample 700 g in 10 l of $15{\sim}95%$ spirit solution for 70 days were investigated. Color b was increased according to lower ethanol concentration and longer soaking periods. Extract was increased gradually with soaking periods, and the content was $0.6{\sim}0.7%$ (w/v) with stem, $1.0{\sim}1.5%$ (w/v) with root. Eleutheroside B and E were extracted rapidly within 20 days of soaking, moreover were increased according to ethanol concentration within 15% to 70%. Acantoic acid was extracted rapidly $2.8{\sim}22.6\;{\mu}g/ml$ with stem, and $560{\sim}1,700\;{\mu}g/ml$ with root within 5 to 10 days. For preparation of liqueur of Acanthopanax koreanum, it is necessary to soak more portion of dried root with $60{\sim}80%$ ethanol concentration for $30{\sim}50$ days, and then to blend after aging for 13 weeks.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.154-159
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• 2007

In order to prepare liqueur of Citrus platymamma, 500 g dried peel was soaked in 10 l (5%, w/v) of $30{\sim}95%$ ethanol concentration for 70 days. Changes in pH was $5.19{\sim}4.80$ with 30% ethanol concentration, and the pH was decreased as ethanol concentration decreases for 10 days after soaking. Color a-value was decreased and color b-value was increased according to higher ethanol concentration. Extract was $2.00{\sim}2.19%$ (w/v) with $30{\sim}70%$ ethanol concentration. Acid content was $0.18{\sim}0.21%$ (v/v) with $30{\sim}70%$ ethanol concentration, while $0.13{\sim}0.15%$ (v/v) with 95% ethanol concentration. The contents of fructose and glucose was increased with lower ethanol concentration, and sucrose content was decreased with longer soaking time. Main flavonoids were narirutin, hesperidin, nobiletin, 3,5,6,7,8,3'4'-methoxylated flavone, and tangeretin. Most flavonoids were extracted more than 80% of ethanol for $3{\sim}5$ days soaking. Total polyphenol was $628.8{\sim}711.2$ ${\mu}g/ml$ with $30{\sim}70%$ ethanol concentration for 20 days soaking. Therefore, to prepare Citrus platymamma peel liqueur, it is necessary to soak the material in $50{\sim}70%$ ethanol concentration for 20 days.