• Journal of the Mineralogical Society of Korea
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• v.21 no.3
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• pp.247-259
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• 2008

$TiO_2$ coatings on kaolinite powders by sol-gel method were carried out using mixture of titanium isopropoxide, ethanol as solvent, HCl as a catalyst and $H_{2}O$ for hydrolysis. The mole ratio of reaction mixture, stirring time. aging time, crystallization time and crystallization temperature influenced to the crystallization of $TiO_2$ coated on kaolinite and metakaolinite Powders. Optimum condition for $TiO_2$ coatings on kaolinite was as follows; TIP 0.1 mol, $H_{2}O$ 0.15 mol, HCl 0.005 mol, ethanol 100 ml, raw kaolinite 50 g, stirring time 4 hrs, aging time 24 hrs, crystallization time 2 hrs and crystallization temperature $1050^{\circ}C$. The crystallinity of the anatase under optimum condition was about 17.61%. The anatase crystallinity of the $TiO_2$ coated on raw kaolinitc powders (17.61% at $1050^{\circ}C$) was higher at the lower calcination temperature compared with metakaolinite (17.39% at $1200^{\circ}C$).

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.639-646
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• 2007

This study performed several tests for the durability of the concrete coated with nano synthesis ceramics which do not contain volatile organic compounds harmful to environment. The tests were adhesion test on dry and humid concrete, SEM test, MIP analysis, carbonation, chloride diffusion by electronic facilitation, freezing-thawing resistance, alkaline resistance, and brine resistance test. In the adhesion test on dry and humid concrete, nano synthesis ceramics coating produced the highest results among all the coatings tested. Nano synthesis ceramics adhered solidly on the concrete surface. The adhesive strength seemed to result from the hydrogen bond between nano synthesis ceramics which are inorganic and generated by hydrolysis and re-condensation reaction and the concrete's hydrates such as calcium silicate aluminate or calcium silicate hydrate. SEM test and MIP analysis results show surface structure with finest crevices pore in the nano synthesis ceramics coating applied concretes. In the carbonation, chloride diffusion, and freezing-thawing resistance tests, the concretes with nano synthesis ceramics coating indicated the best results. Based on these test results, further progress in application of nano synthesis ceramics coatings to various concrete structures including costal structures and sewerage arrangements can be expected.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.497-502
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• 1997

For the purpose of enzymatic production of galactooligosaccharides from soybean arabinogalactan (SAG) hydrolysis, the $\beta$-1, 4-D-arabinogalactanase($\beta$-1, 4-galactanase) from Bacillus sp. HJ-12 was used. The soybean galactooligosaccharides(SOS) were optimally produced in SAG 1%(w/v), pH 8.0, 5$0^{\circ}C$, $\beta$-1, 4-galactanase 20unit/g SAG and 24-40 hour reaction conditions. The produced galactooligosaccharides had visocity of 11,000 cp at 75%(w/v), $25^{\circ}C$. The viscosity of galactooligosaccharides was 80 fold increasing value than that of sucrose solution. Temperature dependence of viscosity of SOS was 4.6 fold higher value than surose solution below than 5$0^{\circ}C$. Less than 50 Brix, the viscosity of SOS was similar with sucrose solution(20-40 cp), but increasing of concentration, the difference of viscosity between SOS and sucrose solution was increased. And, SOS was very stable at pH and temperature.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.121-127
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• 2016

BACKGROUND: Anaerobic digestion is the most feasible technology because not only the energy embedded in organic matters can be recovered, but also they are stabilized while being degraded. This study carried out to improve methane yield of slaughterhouse wastewater treatment sludge cake by the thermal pre-treatment prior to anaerobic digestion.METHODS AND RESULTS: Slaughterhouse wastewater treatment sludge cake was pre-treated by the closed hydrothermal reactor at reaction temperature of 190℃. BMPs (Biochemical methane potential) of the thermal hydrolysate was tested in the different S(Substrate)/I(Inoculum) ratio conditions. COD(Chemical oxygen demand) and SCOD(Soluble chemical oxygen demand) contents of thermal hydrolysate were 10.99% and 10.55%, respectively, then, the 96.00% of COD was remained as a soluble form. The theoretical methane potential of thermal hydrolysate was 0.51 Nm³ kg^-1-VS_added. And BMPs were decreased from 0.56 to 0.22 Nm³ kg^-1-VS_added when S/I ratio were increased from 0.1 to 2.0 in the VS content basis. Those were decreased from 0.32 to 0.13 Nm³ kg^-1-COD_added when S/I ratio were increased from 0.1 to 2.0 based on COD content. The anaerobic degradability of VS basis have showed 196.9%, 102.2%, 80.7%, 67.4%, and 39.4% in S/I ratios of 0.1, 0.3, 0.5, 1.0, and 2.0, respectively. Also the COD of 119.6%, 76.3%, 70.1%, 69.0%, and 43.1% were degraded anaerobically in S/I ratios of 0.1, 0.3, 0.5, 1.0, and 2.0, respectively.CONCLUSION: BMPs obtained in the S/I ratios of 0.1 and 0.3 was overestimated by the residual organic matters remaining at the inoculum. And inhibitory effect was observed in the highest S/I ratio of 2.0. The optimum S/I ratios giving reasonable BMPs might be in the range of 0.5 and 1.0 in S/I ratio. Therefore VS biodegradability of thermal hydrolysate was in 67.4-80.7% and COD biodegradability showed 69.0-70.1%.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.450-457
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• 1986

For the removal of raffinose and stachyose related to flatulence in soybean, ${\alpha}-Galactosidase$ activity of six commercial enzyme preparations was compared and their enzymatic characteristics were investigated. Among the tested enzymes, one product from Aspergillus niger was shown to be the most potent in ${\alpha}-Galactosidase$ activity. The enzyme characteristics of the selected preparation were shown to be pH 4.0-4.5 for optimum activity, pH 4-5 for optimum stability and $45^{\circ}C$ for optimum activity. Upon reaction on a synthetic substrate, $p-nitrophenyl-{\alpha}-D-galactoside$, Michaelis constant was 2.08 mM and maximum velocity was 435 micromoles of substrate/minute/g enzyme preparation. The enzyme was proved to be essential for SH group for its activity and capable of hydrolyzing raffinose, sucrose and $p-nitrophenyl-{\alpha}-D-galactoside$ almost completely. Thin-layer chromatographic analysis exhibited that the enzyme treatments of raffinose and stachyose were resulted to produce only monosaccharides in 2 hours of hydrolysis. It was, therefore, assumed that the flatulence factor in soybean foods can be easily removed by the use of enzymes showing ${\alpha}-Galactosidase$ activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.417-425
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• 2009

The potential utility of fish scales to the functional food industry has been investigated due to its antioxidant and antihypertensive characteristics. In this study, we report on the reactive oxygen species (ROS) scavenging and angiotensin I converting enzyme (ACE) inhibitory activities of gelatin hydrolysates processed from Branchiostegus japonicus scales, which are also high in protein content (about 46.1%). We prepared the enzymatic gelatin hydrolysates with four proteases (${\alpha}$-chymotrypsin, Alcalase, Neutrase and trypsin) from B. japonicus scale gelatin, which was prepared according to different reaction times, substrate/enzyme ratios and substrate concentrations. The enzymatic hydrolytic degrees of the gelatin increased time-dependently up to 6 hrs, while the Alcalase gelatin hydrolysates showed the highest hydrolysis degrees compared to the others. Furthermore, gelatin hydrolysates of Neutrase and ${\alpha}$-chymotrypsin showed the highest DPPH radical and $H_2O_2$ scavenging activities ($IC_{50}$ value; 9.18 mg/mL and 9.74 mg/mL), respectively. However, the activities were not significant (P<0.05). We also observed that the four gelatin hydrolysates significantly increased ACE inhibitory activities from approximately 20% to 60% (P<0.05), Among them, the Alcalase gelatin hydrolysates showed the higher ACE inhibitory activity ($IC_{50}$ value; 0.73 mg/mL) compared to the others. These results suggest that the enzymatic gelatin hydrolysates prepared from B. japonicus scales may possess a potentially useful function as an ACE inhibitory agent. As such, the utility of B. japonicus scales should be given due consideration for application in the functional food industry.

• Applied Biological Chemistry
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• v.21 no.1
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• pp.35-39
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• 1978

1) Caramel and original soybean sauce was obtained from under grade wheat flour. 2) Mixture of under grade wheat flour and ammonium Chloride or HCl was parched. Parch substance were mixed with water, and then were filtrated. This filtrated liquid is liquid of dextrin. The residue of the filtrated substance was contained protein and others. Liquid of dextrin were treated with HCl until reaction of $I_2$ is colorless. Liquid of dextrin was caramelized. The original soybean sause was obtained by the hydrolysis of residue. 3) Parching 200g of under grade wheat flour with 7g of ammonium chloride under $140^{\circ}C$. for 90mins. and then add about 200ml of water to it. About 150ml. of dextrin soln's can be obtain after filtration. 4) Caramelizing 150ml. of dextrin soln's was treated with liq. ammonia at $120^{\circ}C$ for 270mins. under $pH\;5{\sim}6$. it was possible to obtain 95g of $24^{\circ}B\acute{e}$ caramel. 5) When 25g of residue was hydrolysised with 75ml. of 18% HCl for 8hrs. boiling. it was possible to obtain 55ml. of $25^{\circ}B\acute{e}$ original soybean sauce. It is contain 2.20% of nitrogen.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.287-294
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• 2008

Three amino acid residues (His119, Glu164, and Glu338) in the active site of Thermus caldophilus GK24 ${\beta}$-glycosidase (Tca ${\beta}$-glycosidase), a family 1 glycosyl hydrolase, were mutated by site-directed mutagenesis. To verify the key catalytic residues, Glu164 and Glu338 were changed to Gly and Gln, respectively. The E164G mutation resulted in drastic reductions of both ${\beta}$-galactosidase and ${\beta}$-glucosidase activities, and the E338Q mutation caused complete loss of activity, confirming that the two residues are essential for the reaction process of glycosidic linkage hydrolysis. To investigate the role of His119 in substrate binding and enzyme activity, the residue was substituted with Gly. The H119G mutant showed 53-fold reduced activity on 5mM p-nitrophenyl ${\beta}$-D-galactopyranoside, when compared with the wild type; however, both the wild-type and mutant enzymes showed similar activity on 5mM p-nitrophenyl ${\beta}$-D-glucopyranoside at $75^{\circ}C$. Kinetic analysis with p-nitrophenyl ${\beta}$-D-galactopyranoside revealed that the $k_{cat}$ value of the H119G mutant was 76.3-fold lower than that of the wild type, but the $K_m$ of the mutant was 15.3-fold higher than that of the wild type owing to the much lower affinity of the mutant. Thus, the catalytic efficiency $(k_{cat}/K_m)$ of the mutant decreased to 0.08% to that of the wild type. The $k_{cat}$ value of the H119G mutant for p-nitrophenyl ${\beta}$-D-glucopyranoside was 5.l-fold higher than that of the wild type, but the catalytic efficiency of the mutant was 2.5% of that of the wild type. The H119G mutation gave rise to changes in optima pH (from 5.5-6.5 to 5.5) and temperature (from $90^{\circ}C\;to\;80-85^{\circ}C$). This difference of temperature optima originated in the decrease of H119G's thermostability. These results indicate that His119 is a crucial residue in ${\beta}$-galactosidase and ${\beta}$-glucosidase activities and also influences the enzyme's substrate binding affinity and thermostability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.149-159
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• 1998

To utilize the oyster shell containing a lot of calcium, we investigated the bioavailability of calcium compounds from oyster shell. First, calcium oxide was prepared by burning of oyster shell at $1200^{\circ}C$. Its purity was approximately $98.5\%$. Calcium compounds, $CaCl_2$, and $CaHPO_4$, from the calcium oxide were prepared by chemical reaction. Effect on calcium absorption by the calcium compounds from oyster shell was improved using fish skin gelatin peptides.(FSGP), which was prepared by enzymatic hydrolysis of fish skin gelatin for 4hr with tuna pyloric caeca crude enzyme (TPCCE). in vitro experiment, calcium absorption by addition of FSGP in a mixture solution of calcium and phosphate was higher approximately $70\%$ than that by control. in vivo using calcium deficient rats, a group taken the diets with $3\%$ FSGP and $CaHPO_4$ was significantly improved amount of calcium and ash in femur and strength of femur. These results suggest that calcium compounds from oyster shell and FSGP could be used as an effective dietary calcium source.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.491-497
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• 2004

Holographic quantitative structure activity relationships (HQSAR) between the melanogenesis inhibitory activities of alkyl-3,4-dihydroxybenzoate (A) and N-Alkyl-3,4-dihydroxybenzamide (B) derivatives were analyzed and discussed. The statistical results of HQSAR model for the activities showed the best predictability of the activities based on the cross-validated $r^2_{cv}\;(q^2=0.674),$ non-cross-validated, conventional coefficient $(r^2_{ncv}=0.936).$ The melanogenesis inhibitory activities and hydrolytic reactivity of (A) were slightly higher than that of (B) (A>B) and the activities depends upon the $R_1-substituents\;(R_1>R_2).$ It has been found using frontier molecular orbital (FMO) theory that the hydrolysis reactions of (A) and (B) proceeded to an orbital-controlled reactions, while the nucleophillc addition-elimination reactions $(Ad_{N-E})$ between LUMO energy of (A) and (B) and HOMO energy of water molecule are occurred.