• Journal of Welding and Joining
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• v.27 no.3
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• pp.38-43
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• 2009

The optimization of the welding parameters was studied to maximize the weldability and minimize the amount of spatter in the MAG welding of automotive steel sheets under different shielding gas composition ratio. JS-EFSC, JS-SPHC steel plates and Ar mixture gases were used as a substrate and shielding gas for welding respectively. The five welding parameters were selected through preliminary experiments and their effects on the weldability were analyzed. Experiments were performed using the Taguchi experimental method. As results, appropriate range for welding could be achieved. Amount of spatter in 80%Ar+20%$CO_2$ shielding gas was 20% of that of $CO_2$welding. Therefore, in terms of high productivity and welding cost, Ar mixture gas(80%Ar+20%$CO_2$) was recommended as a shielding gas for application of MAG process, indicating the low spatter and good weld quality.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.1-8
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• 2023

In this study, to reduce CO₂ emission in the cement manufacturing process, we evaluated the limestone that is used as a raw material for cement, substituted with steel slag by the various substituted levels. Based on the chemical composition of each raw materials including limestone, and blast furnace slow cooling slag, converter slag, and KR slag as an alternative raw material, we simulated the optimal cement raw mixture by the substitution levels of limestone. Test results indicated that the steel slags contain a certain level of CaO that can be used as alternative decarbonated raw materials, and it has enough to partially reduce the amount of limestonem. And we estimated the maximum usable levels of each raw material. In particular, it was confirmed that by using a mixture of these raw materials rather than using them one by one, the effect of reducing limestone was increased and CO₂ emission from the cement manufacturing process could be reduced.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.325-328
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• 2001

Teicoplanin is a glycopeptide antibiotic produced by Actinoplanes teichomyceticus novo sp. A TCC 31121. It is active against Gram-positive bacteria and it is under evaluation for use in man. Teicoplanin mixture in fermentation broth contains major amounts of teicoplanin $A_1$ and $A_2$ and a minor amount tcicoplanin of $A_3$. Commercial teicoplanin product is composed of five major components of very similar polarity, designated T-$A_2$-l, 2, 3, 4 and 5, and the more polor component, designated T -$A_3$. The culture conditions were studied in order that hydrophilic teicoplanin $A_2$ components are more produced but hydrophobic teicoplanin $A_1$ with lower bioactivity are less produced in submerged culture. Effects of culture pH and nutrients on the biosynthes ratio of teicoplanin $A_1$ and $A_2$ were confirmed in flask culture using MOPS buffer system through TLC, bioautography and bioassay. It was elucidated that optimal pH is 7.4 for teicoplanin $A_2$ biosynthesis but is 5.2 for teicoplanin $A_1$ biosynthesis, and that trace elements stimulate $A_2$ production but malt extract stimulate $A_1$production.

• Culinary science and hospitality research
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• v.7 no.3
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• pp.145-161
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• 2001

In odor to develop fillet-type seasoner and mixed powder-type seasoner using smoked mackerel as primary material, processing conditions of the mackerel meat and flavoring extract from various materials were examined. The approximate composition of mackerel meat and mixed powde-type seasoner using mackerel as primary material were 10.9 and 11.7%, for moisture 79.1 and 57.2% for crude protein, 5.3 and 2.9% for crude lipid, and 4.3 and 24.6% for crude ash, respectively. It was suitable to simmer raw mackerel in 3% chitooligosaccaride solution at 8$0^{\circ}C$ for 10 min., for the enhancement of reaction their meat and chitooligosaccharide. Considering effect of type of woodsmoke on organoletic properties of mackerel after smoking, oak and mixture(oak wood ＋ citrus wood = 1 : 1) were superior to another woodsmoke, the smoking conditions favoring the most overall preference were 8$0^{\circ}C$, 25min. for smoking time, 20$0^{\circ}C$, 20min. for baking, and 10$0^{\circ}C$. 4hrs. for drying. The optimal material mixing ratio for mixed powder-type seasoner was powder of smoked mackerel 60%, dried anchovy 15%, dried sea tangle 10%. The most appropriate extraction condition of mixed powder seasoner with packing tea bag(10g/bag) was 98$^{\circ}C$ for 5min. in the boiling water.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.322-327
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• 2023

A design of experiments was evaluated in optimizing MOF-5 synthesis for acetylene adsorption. At first, mixture design was used to optimize precursor concentration, terephthalic acid, zinc acetate dihydrate and N,N-dimethylformamide. More specifically, 13 conditions with various molar ratios were designed by extreme vertices design method. After preparing the samples, XRD, N₂ physisorption and SEM analysis were performed for their characterization. Moreover, acetylene adsorption experiments were carried out over the samples under identical conditions. The optimal precursor composition for MOF-5 synthesis was predicted on a molar basis as follows: terephthalic acid : acetate dihydrate : dimethylformamide = 0.1 : 0.4 : 0.5. Thereafter, multi-level factorial design was designated to investigate the effect of synthesis reaction conditions such as temperature, time and stirring speed. By the statistical analysis of 18 samples designed, 4 reaction parameters were determined for additional adsorption experiments. Therefore, MOF-5 prepared under the synthesis time and temperature of 100 ℃ and 12 h, respectively, showed the maximum adsorption capacity of 15.1 mmol/g.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.321-330
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• 2009

This study was conducted to develop a recipe for a nutritional cookie containing chungkukjang powder that had a composition of ingredients and a texture that resulted in a high preference by all age groups. Wheat flour was partially substituted with chungkukjang powder to reduce its content. Response surface methodology was then used to analyze the measured results, which showed 16 experimental points including 2 replicates for chungkukjang powder, butter and sugar. The compositional and functional properties were then measured, after which these values were applied to a mathematical model. A canonical form and perturbation plot revealed the influence of each ingredient on the final mixture. The results of the sensory evaluation showed significant values with respect to color (p<0.01), texture (p<0.05) and overall quality (p<0.05). Taken together, the results of this study indicated that the optimal ratio was 26.57 g of chungkukjang powder, and 82.08 g of butter for every 52.36 g of sugar. The physical and chemical sensory measurements were then evaluated by a t-test, and the results revealed significant differences in the flavor of the optimized cookie when compared to the control cookie.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.21-21
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• 2014

A edible mushroom, Hypsizygus marmoreus is commercially cultivated in Northeast Asia. Japan's annual production is 110,000ton or more. Since 2002, cultivation is expanded in Korea. To investigate the morphological, cultural and microscopic characteristics of Hypsizygus marmoreus, 109 isolates were collected from Korea and other countries. Clamp connection, chlamydospore and arthrospore were present in all tested isolates of H. marmoreus except HYM-002 and HYM-004. Also pilealtrama, gilltrama, basidia, basidiospore and cystidia of fruiting body were no difference among the isolates in the present investigation. Morphological characteristics of fruiting body was that color of pileus was brown and white, irregular as marble, the average size 12~22mm and stipes was $46{\sim}91{\times}6{\sim}10mm$. Isolates HYM-031, HYM-047 and HYM-109 formed grayish-brown pileus with a faint pattern. Molecular analysis with RAPD and ITS rDNA sequence analysis were also performed to check the genetic relationships among H. marmoreus isolates. Based on the RAPD analysis using the URP-PCR, all isolates of H. marmoreus were clustered into large 3 groups but more than 90% showed high similarity. In addition, morphological and geographical differences have been classified as an independent cluster. The brown and white strains enclosed in same cluster. So genetically no significance difference was observed between these two strains. ITS gene sequences of 16 selected isolates which were 640 bp long, were aligned and compared. The similarity in ITS sequence was 94.8 to 99.1% among tested isolates and the H. marmoreus isolates in GeneBank. In conclusion the tested isolates were H. marmoreus. Morphological and molecular observations proved that all tested isolates were belonging to H. marmoreus. For the stable artificial cultivation, composition of optimum media, mature period and light condition were established. Optimal formula of artificial cultivation medium was Douglas sawdust: corn cob: soybean meal: wheat bran = 40:30:15:15. In addition, 7% rice bran and 3% yellow sucrose was the most effective composition for spawn's liquid medium. For the maturation of the isolates was favorable for growing for 20 to 30 days at $25^{\circ}C$ and the LED lights in mixture of white and blue was good for growth period. For effective growth, the temperature, humidity and aeration control in every step was important.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.402-407
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• 2022

Statistical design of experiments was used to optimize the MOF-5 synthesis process. A mixture design was employed to optimize precursor concentration. The optimal composition of three chemical materials, terephthalic acid, zinc acetate dihydrate, and N,N-dimethylformamide for MOF-5 synthesis was determined by extreme vertices design methods as follows; 1 mol : 2.7 mol : 40 mol. A multilevel factorial design was selected to screen the significance of synthesis reaction conditions such as temperature, time, and stirring speed. Statistical analysis results suggested excluding stirring speed from further investigation. Using a central composition design, the synthesis time and temperature were optimized. The quadratic model equation was derived from 13 synthesis experiments. The model predicted that MOF-5 synthesized at 119 ℃ for 10.4 h had the highest crystallinity.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.76-83
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• 2008

The aim of this study was to use arrowroot powder to develop a recipe for a nutritional cookie having the optimal composition of ingredients and texture to elict a strong preference response in all age groups. Wheat flour was partially substituted with arrowroot powder to reduce the wheat flour content of the cookie. Measurements were made and analyzed according to the Response Surface Methodology technique, which showed 16 experimental points including 2 replicates for arrowroot powder, yellow sugar and butter. The compositional and functional properties of the test were measured, and the values obtained were applied to a mathematical model. A canonical form and perturbation plot showed the influence of each ingredient on the final mixture product. The result of sensory evaluation showed very significant values for color (p<0.01), appearance (p<0.001), texture (p<0.05), overall quality (p<0.05), and flavor (p<0.05). Instrumental analysis showed significant values for lightness (p<0.001), redness (p<0.01), yellowness (p<0.01) and spread ratio (p<0.001). The optimal sensory ratios were determined to be 15g for the arrowroot powder, 70 g for sugar and 80 g for butter.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.63-68
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• 2014

In this study, it was found that determined the photocatalytic degradation of antibiotics (lincomycin, LM) with various catalyst composite of titanium dioxide ($TiO_2$), hydroxyapatite (HAP) and germanium (Ge) under UV-A irradiation. At first, various type of complex catalysts were investigated to compare the enhanced photocatalytic potential. It was observed that in order to obtain the removal efficiencies were $TiO_2/HAP/Ge$ > $TiO_2/Ge$ > $TiO_2/HAP$. The composition of $TiO_2/HAP/Ge$ using a statistical approach based on mixture analysis design, one of response surface method was investigated. The independent variables of $TiO_2$ ($X_1$), HAP ($X_2$) and Ge ($X_3$) which consisted of 6 condition in each variables was set up to determine the effects on LM ($Y_1$) and TOC ($Y_2$) degradation. Regression analysis on analysis of variance (ANOVA) showed significant p-value (p < 0.05) and high coefficients for determination value ($R^2$ of $Y_1=99.28%$ and $R^2$ of $Y_2=98.91%$). Contour plot and response curve showed that the effects of $TiO_2/HAP/Ge$ composition for LM degradation under UV-A irradiation. And the estimated optimal composition for TOC removal ($Y_2$) were $X_1=0.6913$, $X_2=0.2313$ and $X_3=0.0756$ by coded value. By comparison with actual applications, the experimental results were found to be in good agreement with the model's predictions, with mean results for LM and TOC removal of 99.2% and 49.3%, respectively.