• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.103-109
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• 2009

In order to isolate antibiotic producing microorganisms, several actinomycetes were isolated from soil samples. The aerial hyphae of Y-88 strain were gray in color with tree types. Under the microscopic examination, the Y-88 isolate formed a spiral aerial spore mass with a smooth surface and a rectiflexibilis type of spore chain. Y-88 utilized glucose, fructose, arabinose, and sucrose, but not rhamnose, raffinose, mannitol, or inositol. In addition, Y-88 produced melanin on the tyrosine agar and the strain could utilize L-valine, L-phenylalanine, and L-hydroxyproline. Based on these results and the cultural and physiological characteristics described in the Bergey's Manual, the Actinomycetes, Y-88, was identificated as a Streptomyces species. The optimum medium conditions for this antibiotic producing Streptomyces sp. Y-88 was 1.6% soluble starch, 0.6% glucose, 0.6% beef extract, 0.01% $K_2HPO_4$, 0.01% $MgSO_4$ $7H_2O$, and 0.01% $ZnSO_4$ $7H_2O$ at an initial pH of 4.0, and 25$^{\circ}C$.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.390-396
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• 1992

Streptomyces minoensis DMCJ-144 isolated from soil produces the ${\alpha}-amylase$ inhibitor. Optimum culture conditions for ${\alpha}-amylase$ inhibitor production of the strain were determined in this experiment. The optimum composition of the culture medium was studied by supplementing various carbon sources, nitrogen sources, vitamins, and metal salts to the basal medium containing 1% glucose, 0.1% asparagine, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $K_2HPO_4$, 0.005% NaCl. Other culture conditions such as the culture temperature, initial pH of the medium, aeration, and culture time were also investigated. When the strain was cultured in a 100 ml flask containing 20 ml of 2% glucose, 0.5% beef extract, 0.0002% riboflavin, 0.0002% thiamine HCI, 0.01% $ZnCl_2$, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $CuSO_4{\cdot}5H_2O$, 0.005% NaCl, pH 7.2, 180 rpm at $30^{\circ}C$, the maximum production of the ${\alpha}-amylase$ inhibitor was observed after 5 days of the cultivation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.141-147
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• 2005

This study investigated air pollutant levels and physiological variation of Ginkgo biloba in Chuncheon. The results were as follows: The annual average concentrations of $SO_2,\;NO_2\;and\;PM10$ were 0.004ppm, 0.013 ppm and $66{\mu}g/m^3$, respectively. The volume weighted average concentrations of ionic components were $SO_4\;^{2-}\;3.584 mg/m^3,\;NO_3^-\; 2.803 mg/m^3,\;Cl^-\;1.485 mg/m^3\;and\;NH_4\;^+\;0.998 mgg/m^3$ in precipitation. The annual wet deposition amount of the major ions was shown to be $SO_4^{2-}\;3.865g/m^2/yr,\;NO_3^-\;2.924g/m^2/yr,\;Cl^-\;2.773g/m^2/yr\;and\; NH_4\;^+\;1.485 g/m^2/yr$ during this study period. The seasonal averaged pH in leaves were spring pH 5.9 0.5, summer pH 5.5 0.4 and fall pH 5.1 0.3. The seasonal average water soluble sulfur content in leaves were spring 0.012 0.004%, summer $0.012\;0.002\%\;and\;fall\;0.020\;0.007\%$. The seasonal average water soluble sulfur content in bark were spring $0.0071\;0.0003\%,\;summer\; 0.0066\;0.0004\%,\;fall\;0.0063\;0.0004\%\;and\;winter\;0.0071\;0.0003\%$.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.20-25
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• 2000

The wastewater treatment for the purpose of water-recycling was performed using Fenton's & ozone's methods. These methods were used to increase the treatment efficiency of textile wastewater and to search for the optimal operating conditions. The optimal conditions by Fenton process were determined so that input amounts of $FeSO_4{\cdot}7H_2O$ and $H_2O_2$ were $7.2mM/{\;}{\ell}$ and $49.0m/{\;}{\ell}$ respectively, treatment by ozone process had 92% removal efficiency at ozone concentration of 9.73g/min and $130mM/{\;}{\ell}$ of $H_2O_2$.

• KSBB Journal
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• v.14 no.2
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• pp.167-173
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• 1999

A new synthetic medium was developed for the submerged mycelial cultures of Phellinus linteus. The medium for maximum mycelial growth of Phellinus linteus (3 days incubation, 28$^{\circ}C$, pH 5) consisted of (per 1 L): glucose, 90 g peptone, 10 g soluble starch, 10 g yeast extract, 3 g KH2PO4, 1 g MgSO4.7H2O, 1 g and CaCl2, 0.1 g. The concentrations of glucose, peptone, yeast extract, KH2PO4, MgSO4.7H2O, and CaCl2 were examined in the ranges of 10~90 g/L, 0~10 g/L, 0~15 g/L, 0~2 g/L, 0~1 g/L, and 0~0.5 g/L, respectively. The dry weight of mycelium in 3 days increased to 16.79 mg/mL using the new synthetic medium. The optimum temperature for mycelial growth of Phellinus linteus was 28$^{\circ}C$. The concentrations of KH2OP4, CaCl2, and yeast extract, which gave the maximum mycelial growth of Phellinus linteus, existed in the concentration ranges examined in this study. But, in the cases of other compositions (MgSO4.7H2O, peptone, and glucose), the mycelial growth of Phellinus linteus increased with the concentration in the ranges.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.622-628
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• 1998

Microorganisms isolated from soil were tested for their flocculating activity in kaolin suspension, Identification of the best producing CH-23 strain showed that the strain belonged to the Bacillus megaterium. The maximum production of the flocculating from Bacillus megaterium CH-23 was observed in the culture medium containing 2% sucrose, 3% NaNo3, 0.1% K2HPO4, 0.5% NaCl, 0.5% MgSO4.7H2O and 0.01% tryptone at initial pH 7.0 and 25~3$0^{\circ}C$. Flocculating activity was improved to 57% when the culture medium contained Mn2+(0.01% MnSo4). In the culture medium containing Mg2+(0.01% MgSO4.7H2O) and Ca2+(0.01% CaCO3), flocculating activity were reached to 48% and 33%, respectively.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.584-588
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• 2011

In this work, effects of limestone powder on hydration of $C_3A-CaSO_4{\cdot}2H_2O$ system was discussed based on the XRD Quantitative analysis, and the possibility of Delayed Ettringite Formation was also discussed. The early hydration of $C_3A$ was delayed by addition of $CaCO_3$ powder. The delay effect was enhanced by increasing of $CaCO_3$ content and finer powder of $CaCO_3$ addition. After consumption of $CaSO_4{\cdot}2H_2O$, the reaction of $CaCO_3$ is started. Delayed Ettringite Formation would take place because monosulfoaluminate is not stable in presence of $CaCO_3$. In order to prevent the delayed ettringite formation in $C_3A-CaSO_4{\cdot}2H_2O-CaCO_3$ system, the reduction of monosulfoaluminate formation is important. Therefore, by increasing the amount of $CaCO_3$ addition and finer $CaCO_3$ powder addition, the delayed ettringite formation can be prevented.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1084-1091
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• 2013

In this paper, two statistical methods were applied to optimize medium components to improve the production of the milk-clotting enzyme by Bacillus amyloliquefaciens D4. First, wheat bran juice, skim milk powder, and $Na_2HPO_4$ were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, an optimal medium was obtained using the Box-Behnken method, which consisted of 3.31 g/l of skim milk powder, 5.0 g/l of sucrose, 0.1 g/l of $FeSO_4{\cdot}7H_2O$, 0.1 g/l of $MgSO_4{\cdot}7H_2O$, 0.1 g/l of $MnSO_4{\cdot}2H_2O$, 0.1 g/l of $ZnSO_4{\cdot}7H_2O$, 1.52 g/l of $Na_2HPO_4$, and 172.45 g/l of wheat bran juice. With this optimal medium, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 3,326.7 SU/ml after incubation of 48 h, which was 1.76-fold higher than that of the basic medium, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize medium components, and B. amyloliquefaciens D4 possessed a high rennet-producing capacity in the optimal medium.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.2
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• pp.99-104
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• 2017

Refractories used in low-rank coal gasification reactors are usually exposed in a highly corrosive $H_2S$ gas at less than $1000^{\circ}C$, and their mechanical properties such as erosion resistance and fracture strength decline with the exposure time. However, the cause of the degradation of the mechanical properties has little reported yet. In this paper, two kinds of castable refractories with different refractoriness had been exposed in a $H_2O/N_2/H_2S$ mixed gas with high $H_2S$ content for 100 hours at $900^{\circ}C$, and the changes of microstructure, crystalline phases and erosion resistance were compared before and after the corrosion test. The weight of the refractories decreases due to the elution of silica in the specimens after the corrosion test. The capillary porosities of the samples are reduced, but the erosion resistance of the samples is fatally weakened after the corrosion test. There also are changes in constituent phases; dmitryivanovite ($CaAl_2O_4$) and amorphous silica ($SiO_2$) disappear, and gypsum ($CaSO_4{\cdot}2H_2OS$) and kaolinite ($Al_2Si_2O_5(OH)_4$) newly appear after the corrosion test. It is obvious that the phase change from dmitryivanovite that works as a binding agent in the castable refractory to gypsum is the main reason of the degradation of the erosion resistance, because the mechanical properties of gypsum are much poorer than those of dmitryivanovite.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.107-113
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• 1986

Laboratory experiments were carried out to investigate the effects of pH, gibbsite, and organic matter on sulfate adsorption by soils. Samples of five soil series (Songjeong, Gopyung, Yeasan, Gyorae, and Namwon), different in physical and chemical properties, were used in this study. The results obtained from sulfate adsorption experiment with sulfate solutions of the concentrations ranging from 50 to 400 ppm were as follows: 1. The adsorption phenomena for five soils were well described by the Freundlich adsorption isotherm over a given range of sulfate concentration. 2. The amounts of sulfate adsorbed and K value of Freundlich adsorption isotherm increased as the initial pH of the suspension decreased. 3. Although the changes in pH of the suspension on the adsorption equilibrium were hardly observed in the soil treated with gibbsite, the sulfate adsorption rates were increased with amount of gibbsite treated. 4. The effects of pH of the suspension on the adsorption rates in the soils treated with gibbsite were remarkable at the level of 0.1% but were little at the level of 1.5%. 5. The adsorption rates of soils, treated with organic matter and incubated for three weeks, were in the order: starch > straw > compost. At the relatively high levels (5 and 10%) of treatments, compost treatment resulted in the sulfate desorption phenomena.