• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.10-16
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• 1997

To confirm the possibility of seaweed extracts for functional food, water or ethyl alcohol solubles were extracted from laver, Porphyra yezoensis and evaluated those food components such as proteins, carbohydrates, nucleic acids, taurine, pigments and browning extent. The amount of proteins, polysaccharides and nucleic acids extracted decreased with increasing ethyl alcohol concentration, which was maximal when water was used as extraction solvent. The extractability of proteins, polysaccharides and nucleic acids was different between the dried and the roasted laver. Taurine was extracted about 1% from the dried and the roasted laver in the range of o~7o% ethyl alcohol concentration. The amount of carotenoids extracted by 95% ethyl alcohol from the dried and the roasted laver were 146.6 and 138.4mg%, respectively, which was 66 ~ 80% of yield extracted by methanol/acetone(1/1) solvent. The browning value of 50 ~6o% ethyl alcohol extraction group from roasted laver was highest among water/ethyl alcohol extraction group. The extraction yield was maximum when laver was extracted with water, and the value was 26.3% for the dried laver and 27.5% for the roasted layer. Organoleptic characteristics from four kinds of extraction groups containing hot water extraction showed that extracts from the roasted laver were evaluated most eminent and thought to be applicable to various preparation of food.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.520-528
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• 2006

Free amino acids in epidermis function as a major component of Natural Moisturizing Factor (NMF), which maintains the optimal level of water in skin even at the low humidity. In fact, the depletion of free amino acids is reported in the epidermis of atopic dermatitis, the skin condition involving dryness. As an effort searching the dietary source for improving the level of water and free amino acid in epidermis, the dietary effects of silk protein, sericin (S) and fibroin (F) on trans epidermal water loss (TEWL), and plasma and epidermal levels of free amino acids were compared in this study. Thirty of male NC/Nga mice, an animal model of atopic dermatitis, were divided into three groups: group CA as an atopic control with control diet, group S: 1% sericin diet and group F: 1% fibroin diet. Ten of male BALB/c mice were served as group C (control group) with control diet. All mice were fed on diet and water ad libitum for 10weeks. Dry skin condition was established in group CA as TEWL was increased (148.7% of group C). In parallel, epidermal level of glutamate, one of major amino acids functioning as NMF, was dramatically decreased and epidermal levels of methionine and alanine were inversely elevated. Dietary supplementation of sericin (group S) reduced TEWL at the similar level with group C and increased epidermal levels of glutamate as well as serine and glycine, the other major amino acids as NMF. Despite a marked decrease of methionine and alanine, the reduction of TEWL and epidermal levels of glutamate, serine and glycine of group F were less than of group S. Furthermore, in contrast to similar levels of other free amino acids in plasma and epidermis of group S and group C, plasma and epidermal levels of other free amino acids, specifically phenylalanine, isoleucine, cysteine and tyrosine in epidermis of group F, were significantly higher than of group C. Together, our data demonstrate that dietary supplementation of sericin is more effective at improving dry skin condition that paralleled with the normalization of free amino acids in plasma and epidermis of NC/Nga mice.

• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.221-231
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• 2012

Uljin cassiterite deposit had been known to be a pegmatitic origin derived from the Wangpiri (Buncheon) granitic gneiss of Precambrian period. Lithium ore also shows the same origin and its lithium bearing mineral was ascertained to be a taeniolite. But the presence of leucocratic granites which played the role of host rocks haven't been clearly designated yet in these provinces. Even though Bonghwa and Youngweol sericite deposits situated in the vicinities of Hambaeg syncline had been known to have their host rocks as Hongjesa Granites of Precambrian period and Pegmatitic migmatite of unknown age respectively. But younger leucocratic granites are characterized by more amounts of albite and sericite (muscovite-3T type) than those of the older granitic rocks which contain plenty of biotite and chlorites. Although the younger granites show rather higher contents of alkalies such as $Na_2O$ (0.13~8.03 wt%) and $K_2O$ (1.71~6.38 wt%), but CaO (0.05~1.21 wt%) is very deficient due to the albitization and greisenization. Manisan granite, which is assumed to be Daebo granite which intruded the Gyunggi Gneiss Complex was again intruded by leucocratic granite whose microclinized part changed into kaolins. Taebaegsan region shows a wide distribution of carbonate rocks which are especially favorable to the ore depositions. And the presence of alkali granites which formed in the later magmatic evolution are well known to be worthwhile to the prospections of various rare metals and REEs resources.

• Journal of the Mineralogical Society of Korea
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• v.29 no.4
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• pp.179-190
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• 2016

X-ray diffraction analysis, chromaticity measurement, execution and evaluation by Dancheong artisan, accelerated weathering test, and fire resistance test were conducted to test the applicability as a Dancheong pigment raw materials of Korean low grade kaolin in cultural properties. The ores that feldspar rich and composed of fine particles (< $38.1{\mu}m$) showing advantageous for the inherent purpose of the white pigment than that of high grade kaolin. And the test of whiteness, concealment force, outdoor exposure durability and fire resistance shows similar or better result than existing products (Hobun and Sanhwa jidang). In conclusion, it is expected that the use of fine feldspar rich white soil and low-grade kaolin can be used as a white pigment raw materials which have similar to better material properties and economic efficiency than existing products.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.193-199
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• 2009

A bacterium producing the halotolerant extracellular protease was isolated from squid jeotgal, and was identified as Bacillus sp. SJ-10 based on morphological, physiological and biochemical characteristics, as well as phylogenetic analysis using 16S rRNA gene sequence. The strain grew at $20^{\circ}C\sim55^{\circ}C$, pH 5~8, and 0%~14% NaCl and optimal growth conditions were $35{\pm}5^{\circ}C$, pH 7, and 5% NaCl. The major cellular fatty acids were anteiso-$C_{15:0}$, anteiso-$C_{17:0}$, and $C_{16:0}$ DNA G+C content was 50.58 mol% and menaquinone consisted of MK-7 Phylogenic analysis based on the 16S rRNA gene sequence indicated that SJ-10T belongs to the genus Bacillus. About 40 kDa of the salt-tolerant protease was purified by 40% ammonium sulfate saturation and Mono Q column chromatography. The optimal activity of the protease was pH 8 and stable at pH 5~10. The optimum temperature and NaCl concentration were $35{\pm}5^{\circ}C$ and $5{\pm}1%$, respectively.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.433-441
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• 2007

This work investigated the stability of a Sn-modified Pt electrode, which was used for reduction of nitrate, fabricated by an adsorption or electro-deposition of Sn on Pt. In order to find the causes for instability of the electrode, the effects of the solutions in which the electrode was used and the potential applied to the electrode on the electrochemical and metallurgical behaviors of Sn on Pt were studied. The Sn of freshly- prepared modified-Sn Pt electrode existed as Sn hydroxide form, which brought about an easy loss of the electro-activity of the electrode even staying in water, especially in acid solution. When the Sn-modified Pt electrode was used for the reduction of nitrate, the electro-activity of the electrode was affected depending on the potential applied to the electrode. When a more negative potential than the redox equilibrium potential between $Sn(OH)_2$ and Sn was applied to the electrode, the Sn hydroxide was converted to Sn that could diffused into Pt, which leaded to the loss of electro-activity of the electrode as well. The solid diffusion of Sn increased linearly with the applied potential. The Sn-electrodeposited Pt electrode which had more Sn on the electrode was more favorable to maintaining the integrity of the electrode during the reduction of nitrate than the Sn-adsorbed Pt electrode prepared in the under-potential deposition way.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.705-711
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• 2017

Lespedeza cuneata (LC) is a herbaceous plant that grows throughout Korea. To investigate the physicochemical properties and the antioxidant activities of LC extracts and LC-soaked liquor (s. liquor), extraction with distilled water (DW) and ethanol was conducted and the extracts were compared with s. liquor. A total of 22 free amino acids from LC extract were detected, with the main ones being phosphoethanolamine 20.36>L-proline 18.02>ammonia 14.48>L-aspartic acid 12.96>${\gamma}$-amino-n-butyric acid 10.67%. The total flavonoid contents (TFC) and total phenolics contents (TPC) were in the order of s. liquor>DW>ethanol extract. The electron donating ability based on DPPH radical scavenging ability was highest for s.liquor, which equivalents 81.4% ascorbic acid in the order of s. liquor>ethanol>DW extract. The orders of ferric reducing antioxidant power and ABTS radical scavenging ability were proportional to the TFC and TPC of extracts, and in the order of s. liquor>ethanol>DW extract. The nitrite scavenging ability of s. liquor was highest among the three extracts (96.6% at pH 1.2), which was 2.6 times greater than that of DW extract.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.118-125
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• 2017

In this study, we examined the bond performance of FRP Hybrid Bars. FRP Hybrid Bars are developed by wrapping glass fibers on the outside of deformed steel rebars to solve the corrosion problem. The surface of the FRP Hybrid Bars was coated with resin and silica sand to enhance its adhesion bonding performance with concrete. Various parameters, such as the resin type, viscosity, and size of the silica sand, were selected in order to find the optimal surface condition of the FRP Hybrid Bars. For the bonding test, FRP Hybrid Bars were embedded in a concrete block with a size of 200 mm3 and the maximum load and slip were measured at the interface between the FRP Hybrid Bar and concrete through the pull-out test. From the experimental results, the maximum load and bond strength were calculated as a function of each experimental variable and the resin type, viscosity and size of the silica sand giving rise to the optimal bond performance were evaluated. The maximum bond strength of the specimen using epoxy resin and No. 5 silica sand was about 35% higher than that of the deformed rebar.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.729-733
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• 2006

Small yellowish brown crystals were found in some concentrated oyster extracts which prepared by heating with the drip and washed water of boiled oyster in oyster processing factories. We collected those crystals by filtering the oyster extracts and analysed X ray diffraction (XRD), scanning electron microscopy (SEM) and minerals by ICP. Those were composed of moisture (8.1%), organic materials (21.6%) and inorganic materials (70.2%). Those major inorganic materials were determined as Ca (53.8%) and P (43.8%), from the ICP and elucidated those crystal as brushite $(CaHPO_4{\cdot}2H_2O)$ by XRD and SEM. Organic materials contained crude protein (33.7%) consisting of 7 amino acids. It is presumed that brushite may be formed by the reaction of excess Ca with P in the oyster extracts during concentrating process under higher temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1002-1010
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• 2003

This study was carried out to develope yeast leavened pan bread using the commercial Doenjangs (Korean soybean pastes). Physicochemical properties of the Doenjang products were measured such as aminonitrogen, pH, titratable acidity and salinity, reducing sugar, total free sugar, total organic acid, PDI (protein dispersibility index) and color. Seven products of Doenjang were freeze-dried and powdered to be used in bread formula at the levels of 2.5, 5.0, 7.5 and 10.0%. When the Doenjang powder was added up to 5.0%, the ovenspring during baking remarkably increased resulting in increased loaf volume. However, with Doenjang powder more than 7.5%, the loaf volume became smaller than the control as the dough expansion and ovenspring decreased. Thus when Doenjang was added to bread dough, the loaf volume was highly correlated with ovenspring (r=0.92) but it was not with dough expansion during 1st fermentation (r=0.56). The browning color of bread crust and crumb became deeper with decrease in L value as the addition of Doenjang powder increased. From the mechanical texture measurements of bread crumb, hardness, gumminess and chewiness decreased with addition of Doenjang powders. Regardless of the kinds of Doenjang, the Doenjang powders could be added into the bread dough up to 5.0%, improving the loaf volume and texture of yeast leavened pan bread and demonstrating the possibility of producing a functional bread using the Doenjang powders.