• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.567-572
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• 1994

Diglyceride was prepared by reaction of hydrogenated beef tallow and glycerol (GL) in the presence of a Pseudomonas lipase. Both substrates were mixed at the ratio of GL/Triglyceride of 0.5 which is the stoichiometric molar ratio for the complete conversion of triglyceride (TG) to diglyceride (DG). DG can be obtained by solid phase-glycerolysis of hydrogenated beef tallow without use of organic solvents or emulsifiers by careful control of reaction temperature. Optimized reaction temperature condition was as follows: An initial incubation at$60^{\circ}C$ for 2h followed by the first temperature shift down to $55^{\circ}C$ for 4h, and then the second shift down to $50^{\circ}C$ for up to 3 days. There was a large decrease in the content of TG during the first $60^{\circ}C$ incubation for 2h. Even a prolonged incubation at $60^{\circ}C$ could not make a change of the composition of the reaction mixture at liquid state. By controlling the temperature lower than $60^{\circ}C$, reaction mixtures were solidified. The reaction temperature at $50^{\circ}C$ below the melting temperature of hydrogenaed beef tallow gave an 71% optimum yield of DG after 72h enzymatic glycerolysis and about 73% of total DG was 1,3-DG.

• Food Science and Preservation
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• v.14 no.5
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• pp.504-510
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• 2007

An extrusion process was to make an onion kimchi snack from rice grit and onion kimchi powder, in an effort to enhance the nutritional value, flavor, and physicochemical properties of the extrudate. This study investigated optimum conditions (moisture content, barrel temperature, and the content of onion kimchi powder) for the production of high-quality rice extrudate products, and measured quality properties (water absorption index, texture, expansion ratio, and color) of rice extrudate to which onion kimchi powder had been added. Onion kimchi powder at 3%, 5%, 7%, and 10% (all w/w) was mixed with rice grit and the mixture then extruded in a twin-screw extruder. The texture of onion kimchi mack became softer as onion kimchi powder level rose, and water absorption ability increased. The expansion ratio and the lightness of extrudates decreased with increases in onion kimchi powder levels. The maximum water absorption index am the minimum hardness were obtained with 10% onion kimchi powder. Rice extrudate with 10% onion kimchi powder was suitable for extrusion cooking md obtained the highest score for overall acceptability by sensory evaluation.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.139-149
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• 2012

Black garlic and Gaeddongssuk (Artemisia annua L.) were extracted using central composite design by response surface methodology (RSM) in 11 conditions (A~K) with $110{\sim}130^{\circ}C$ and 2~4 hr, and then each extracts were monitored for the total phenol, flavonoid contents and antioxidant activities. The optimum extraction conditions for black garlic and Gaeddongssuk are selected 3 conditions ($130^{\circ}C$, 4 hr; $120^{\circ}C$, 3 hr; $130^{\circ}C$, 3 hr) and 1 condition ($120^{\circ}C$, 3 hr), respectively. They were mixed according to the following ratio; 1:0.5, 1:1, 1:1.5 and 1:2 (black garlic: Gaeddongssuk extract, w/w), and then these composites were tested to the total phenol, flavonoid contents and antioxidant activities. Antioxidant activities of black garlic and Gaeddongssuk extracts by $120^{\circ}C$, 3 hr condition were higher. And the optimal mixture ratio of black garlic and Gaeddongssuk was 1:1.5 (w/w).

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.439-450
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• 2020

Global warming caused by the emission of greenhouse gases into the atmosphere is being treated as a major problem for the human life, and mineral carbonation is drawing attention as one of many countermeasures against this situation. In this study, mineral carbonation experiments using autoclaved lightweight concrete (ALC) were performed under various conditions to determine its potential as a carbonation material. ALC can be regarded as a promising material for carbonation because it contains about 27 wt.% of CaO, a major component of mineral carbonation. The CaCO3 content produced as a result of the carbonation of ALC calculated on the assumption that all of the CaO content participates in mineral carbonation is about 40 wt.%. The optimum conditions for the mineral carbonation reaction from ALC are the solid-liquid ratio of 0.01 and the reaction time of 180 minutes when calcite is considered as a single product, or 0.06 and 180 minutes when mixture of calcite and vaterite can be considered. The coexistence of vaterite with calcite at solid-liquid ratio of 0.06 or higher was interpreted to be the case where vaterite formed in the later stage and did not change to calcite until the reaction was completed.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.213-219
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• 2012

Improving the physico-chemical properties of used media by mixing ratio of new plug media (NPM), used plug media (UPM) and perlite is necessary to improve seedling quality. In this study, five treatments were designed to investigate mixing ratio of UPM and NPM by ratio of volume 0 : 100, 25 : 75, 50 : 50, 75 : 25, 100 : 0, respectively. On the other hand, nine treatments were designed to investigate of perlite volumes were added to UPM and mixed media (UPM : NPM (50 : 50)) with 0, 5, 10, and 20% of ratio volume. The physicochemical properties of all mediums and their effect on growth response of tomato and cucumber seedlings were determined. The result indicates that physical properties was improved when NPM was mixed with UPM and at mixed ratio of volume 50 : 50 (v : v) has similar pore spare, bulk density and water retention to NPM. Seedling quality of tomato and cucumber in mixed media (50 : 50) are better than other mixed ratio and similar to NPM. Addition perlite to UPM and mixed media 50 : 50 (v : v) increased the pore space and water retention. Physical properties such as particle density, pore space and bulk density were increased when perlite volume increased. However, the best of seedling quality was observed by the addition at 10% volume of perlite. These results suggested that optimum of mixed ratio for recycled used media is new media and used media 1 : 1 mixed.

• Korean Journal of Agricultural Science
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• v.16 no.2
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• pp.212-224
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• 1989

This paper reports results of an investigation to determine properties of superplasticizered fly ash concrete. The mixture proportions of fly ash were 0, 10, 20 and 30%, by weight of cement, and superplasticizer was added as a percentage of fly ash, 0, 0.6, 12 and 1.8%. To investigate the effective use of the superplasticized fly ash concrete, the basic data were analyzed. The results obtained were summarized as follows : 1. The unit water content was decreased by 1%, 6% and increased by 2% to the ratio of addition of fly ash 10%, 20%, 30%, respectively, but in case of the superplasticized fly ash concrete, it was decreased by 3~16%, 4~14% and 10~17%, at 0.6, 12, and 1.8% dosage of superplasticizer, respectively. 2. In the properties of the fresh fly ash concrete, the slump loss was reduced with the ratio of replacement of fly ash increased, and with times went by. When using superplasticizer in fly ash substituting concrete, the fludity in the concrete was not decreased. 3. The compressive strength of fly ash concrete at early ages was lower than that of ordinary concrete. At the later age of 28 days, the compressive strength with 20% addition of fly ash was increased than that of ordinary concrete. In cased of 10%, 30% addition of fly ash, the compressive strength were reduced. From this, it was proved that the optimum amount of fly ash appears to be about 20%. The compressive strength at all ages of superplasticized fly ash concrete was significantly higher than that of fly ash concrete, with increasing fly ash content. 4. In case of the tensile strength, the effects of the increasing strength with the ages were similar to those of the compressive strtength, and at the later ages was seen a decreasing tendency of strengths. 5. The correlation between compressive and tensile strength of superplasticized fly ash concrete was highly significant. The multiple regression equations of compressive and tensile strength were obtained on a function of the mixture proportion of fly ash and the addition of superplasticizer. The relation between compressive and tensile strength is higher than for ordinary concrete. The strength ratio is 7~11, and it is higher than that of ordinary concrete, 8~10. 6. Bulk density was decreased by 1~3% compared with ordinary concrete with the mixture proportion of fly ash increased, 10~30%, and decreased by 1~2% with the superplasticizer added 0.6~1.8%.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.73-79
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• 2011

Based on the results of Part 1 of our two-parts paper, the possibility on field applicability of CMDS(Coal Mine Drainage Sludge) mixed with bentonite and cement as a liner in landfill sites was investigated. The optimum moisture content that met the landfill liner condition was obtained when the ratio of CMDS: bentonite: cement was 1: 0.5: 0.3 in a lab-scale. The relative compaction was measured in 90.1%, which results for construction field have been generally acceptable. In this study, a large-scale Lysimeter($1.0m{\times}1.5m{\times}2.0m$) was used to simulate the effects of the layer on the freeze/thaw by -20 average temperature. The mixture after freezing/thawing showed compressive strength more than $5kg/cm^2$, which was satisfied with EPA standards. Initial permeability of CMDS was $7.10{\times}10^{-7}cm/s$ and permeability its mixture after freezing/thawing was increased to $9.80{\times}10^{-7}cm/s$. The change of temperature in the layers rises and falls with linear and temperature gradient keep maintain the present state. Moisture contents in the layers have not been radically changed. Through the leaching test determined by KSLT method, it was found that heavy metals excluding Zn and Ni were not leached out or leached out less than the standards during 7 cycles of freezing/thawing process. Since it shows the increased permeability about 1.5 times and slight change in moisture content, but it was satisfied with EPA standar through 7 cycles of freezing/thawing process, this mixture can be applied as a liner in landfill final cover system.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.533-542
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• 2016

We investigate fluidization characteristics of the mixture of rice husk, silica sand and rice husk ash as a preliminary study for valuable utilization of rice husk ash obtained from gasification of rice husk in a fluidized bed reactor. As experiment valuables, the blending ratio of rice husk and sand (rice husk: sand) is selected as 5:95, 10:90, 20:80 and 30:70 on a volume base. Rice husk ash was added with 6 vol% of rice husk for each experiment and air velocity to the reactor was 0~0.63 m/s. In both rice husk/sand and rice husk/sand/ash mixture, the minimum fluidization velocity (Umf) is observed as 0.19~0.21 m/s at feeding of 0~10 vol.% of rice husk and 0.30 m/s at feeding of 20 vol.% of rice husk. With increasing the amount of rice husk up to 30 vol.%, $U_{mf}$ can not measure due to segregation behavior. The mixing index for each experiment is determined using mixing index equation proposed by Brereton and Grace. The mixing index of the mixture of rice husk/sand and rice husk/sand/ash was 0.8~1 and 0.88~1, respectively. The optimum fluidization condition was found for the good mixing and separation of rice husk ash.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.98-109
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• 2016

The study was aimed to investigate the mixing ratio of kiwi and persimmon juices for the production of good quality wine by Saccharomyces cerevisiae Y28. Firstly, the optimum condition of rapidase treatment for the kiwi and persimmon juices was established, thereafter various mixing ratio (10:0, 9:1, 8:2, 7:3, 6:4, 5:5) of kiwi and persimmon was investigated regarding physiochemical properties and flavor compounds of wine. As the result, the optimum conditions were obtained as 0.3% rapidase for 1 h in kiwi and 0.3% rapidase for 3 h in persimmon. According to higher ration of persimmon, the pH of wines increased from 3.69 to 3.77, while the acidity of wines decreased from 2.07% to 1.51% at 14 days fermentation. The ranges of brix and reducing sugar in wines were decreased which ranges around 9.6 to 8.8 and 6.07 to 6.90 g/L, respectively, after fermentation. Major organic acid in wines were identified as tartaric acid, malic acid, and citric acid. A small amount of free sugar such as sucrose and glucose were detected in wines, but fructose was completely absent. The soluble phenolic contents were decreased that ranges around 1.00 to 1.25 g/L, in contrast, browning degree were increased ranges around 0.212 to 0.412 after fermentation. The major flavor components were identified as ethyl acetate and hydrazine, and 1,1-dimethyl. Importantly, phenylethyl alcohol was detected from the all wines that have a typical rose like flavor. But sensory test results and preference of kiwi-persimmon (7:3) mixing wine was better than the other wines.

• Journal of the Korean Ceramic Society
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• v.42 no.4
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• pp.260-268
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• 2005

A heat-resisting diatomite protection tube, using diatomite as a main component, was manufactured through an extrusion molding of ceramic slurry in different component ratios. And its mechanical strength, carbon analysis and microstructural non-homogeneity were investigated. After fixing $60wt\%$ of porous diatomite whose particle size was $50\~100\;{\mu}m$, the optimum mixture ratio with composition variables by changing $1\;wt\%$ of each component that was silica sol$(4.3\~7.3\;wt\%)$ as an inorganic binder, CMC (Sodium CarboxyMethyl Cellulose $(6\~9\;wt\%)$) as an organic binder and paper powder$(4.7\~7.7\;wt\%)$ was obtained. As a result of the investigation on a composition containing $60\;wt\%$ diatomite, $5.3\;wt\%$ silica sol, and $7\;wt\%$ CMC, a heat-resisting protection tube that could be used as a molten steel probe for measuring the temperature and components of molten steel was developed. The bending strength, compressive strength, and elastic modulus of the protection tube developed, that contained $\le2.3\;wt\%$ carbon, were 7.1 MPa, 7.5 MPa, and 1090 MPa, respectively.