• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.236-237
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• 2014

Recently, it changes to the frame construction in the wall type structure for the life span improvement of the apartment house of our country. The execution of the light panel increased while the execution of the frame construction increased. Therefore, the density and absorption ratio of the magnesium oxide matrix according to the wood flour amount of addition ratio property try to be analyze for the lightweight of the surface material of the light panel. The test result, the density has been declined as the addition ratio increase of the wood flour. In the case of the water absorption ratio, water absorption ratio has been increased as addition ratio increase of wood flour. However, wood flour addition ratio 15% determined the most appropriate when considering the density and water absorption ratio.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.76-85
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• 2008

Biological nutrient removal (BNR) sludge was added to a sequencing batch reactor (SBR) in the addition ratios of 0%, 20%, 40%, 50% while observing the variation of nutrient removal characteristics and microorganism groups. When the BNR sludge was added in a ratio over 40%, the characteristics of EBPR (enhanced biological phosphorus removal) was shown at the 27 days. However, a distinct BNR was not shown when the addition ratio of BNR sludge was lower than 40%. The organic removal efficiency were shown as 90% in all SBRs irrespective of the addition ratio of BNR sludge. At the 27 days, the phosphorus removal efficiencies were shown as 40%, 55%, 77% and 69%, respectively, according to the addition ratio of BNR sludge. Overall, efficient nitrification and phosphorus removal was shown when the added BNR sludge ratio was over 40%.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.3
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• pp.106-113
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• 1988

This study was performed to obtain the basic data which can be applied to use of foamihg mortars. 1. At the mixing ratio 1:1, the highest strengths were showed by foaming mortam, respec - tively. But, it. gradually was decreased in poorer mixing ratio and more addition of foam- ing agent. The decreasing rates of strengths were incresed in poorer mixing ratio and more addition of foaming agent. 2. The strengths were decreased up to 77.0-92.8% by mix-foaming type and 36.7-74.4% by pre-foamed type than cement mortar. 3. At the mixing ratio of 1:1, the lowest air contents were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. The increasing rates of air contents were increased in richer mixing ratio and more addition of foaming agent. 4. Air contents were showed up to 26.0-63.8 times by mix-foaming type and 5.8-17.7 times by pre-foamed type than cement mortar, respectively. 5. The correlations between compressive strength and air content were highly significant, respectively. The multiple regression equations of strengths and air content were computed depending on a fuction of mixing ratio and addition of foarning agent. It was highly significant, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.1
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• pp.73-80
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• 1988

This study was performed to obtain the basic data which can be applied to use of foaming mortars. The results obtained were Summarized as follows; 1.At the mixing ratio of 1:1, the highest bulk densities were showed by foaming mortars, respectively. But, it gradually was decreased in poorer mixing ratio and more addition of foaming agent. The decreasing rates of bulk densities were increased in richer mixing ratio and more addition of foaming agent. 2.The bulk densities were decreased up to 38.8-55.9% by mix-foaming type and 9.7-23.6% by pre-foamed type than cement mortar. 3.At the mixing ratio of 1:1, the lowest absorption rates were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. The increasing rates of absorption rates were increased in richer mixing ratio and more addition of foaming agent. 4.Absorption rates when immersed in 72hours were showed up tp 3.41-5.85 times by mix-foaming type and 1.05- 1.S5times by pre -foamed type than cement mortar, it was significantly higher at the early stage of immersed time than cement mortar. 5.The correlations between bulk density and absorption rate were highly singnificant, respectively. The multiple regression equations of bulk density and absorption rate were computed depending on a fuction of mixing ratio and addition of foaming agent. it was highly significant respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.81-82
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• 2018

In this paper, we investigate the characteristics of wet soil concrete according to the addition ratio of liquefaction red mud addition rate by liquefying red mud. as a result, the compressive strength decreased and the water absorption ratio increased as the liquefaction red mud addition rate increased.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.873-882
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• 2018

This research is about the quality characteristics of white bread mixed with varying ratios of Seomcho powder, such as 1%, 3%, 5%, and 7% (Spinacia oleracea L.). The pH level of dough decreased as more Seomcho powder (Spinacia oleracea L.) was added, and 7% addition recorded the lowest pH. The fermentation power of dough expansion decreased as the additional ratio increased in both the first and second proofing, and it was negatively correlated to the fermentation time factor. The moisture content of bread decreased as the addition ratio increased. The bread volume became smaller as the addition ratio increased, but it correlated negatively with its specific volume. The color of the crumb, the lightness and redness decreased in comparison to the control, but the yellowness increased. The total amino acid contents increased as the addition ratio increased, and glutamic acid was positively correlated to the additional ratio. The total free amino acids increased as the additional ratio increased, but cysteine levels were high at 5% and 7% additional ratio. The textural characteristics of the bread, springiness and cohesiveness were lower than the control, but gumminess, brittleness, and hardness were higher than the control. The adhesiveness was realized at 7% additional ratio.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.221-228
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• 2019

This study reports the performance of urea-formaldehyde (UF) resins prepared at two different low formaldehyde/urea (F/U) mole ratios with different numbers of urea addition during synthesis. The second or third urea was added during the synthesis of UF resins to obtain two different low molar ratios of 0.7 and 1.0, respectively. The molecular weights, cure kinetics, and adhesion performance of these resins were characterized by the gel permeation chromatography, differential scanning calorimetry, and tensile shear strength of plywood, respectively. When the number of urea additions and F/U molar ratio increased, the gelation time decreased, whereas the viscosity and molecular weight increased. Further, the UF resins prepared with the second urea and 1.0 molar ratio resulted in greater activation energy than those with third urea and 0.7 molar ratio. Tensile shear strength and formaldehyde emission (FE) of the plywood that bonded with these resins increased when the number of urea additions and molar ratio increased. These results suggest that the UF resins prepared with 0.7 molar ratio and third urea addition provide lower adhesion performance and FE than those resins with 1.0 mole ratio and the second urea addition.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.295-304
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• 2001

This study was conducted to investigate the cooking properties of noodles made from composite flour blended with green tea powder. As the ratio of green tea powder increased, development time was longer than that of the control. The stability of dough showed higher value than the control except 2% addition group. The highest viscosity was at the 4% addition group. but 2% addition group showed the lowest viscosity. As the additional ratio of green tea powder was increased. the volume expansion ratio was increased, but water soluble solid matters contents in all addition groups had a lower level than that of the control. Also, the yellowness level of noodle was increased, but the brightness, redness and color and flavor acceptability was decreased, as the additional ratio was increased. However. 2~4% addition group of green tea powder had a similar acceptability profile to that of the control group.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.583-587
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• 2011

This study evaluated the quality characteristics of yukwa pellets and yukwa bases on the ratio of soju addition (0, 25, 50, 75, and 100% v/v). Yukwa base with 50% ratio of soju addition displayed the highest diameter, volume and specific volume. The yukwa base with 75% ratio of soju addition displayed the longest in length. The weight of yukwa base increased as the ratio of soju increased. Lightness increased in yukwa pellet and yukwa base as the ratio of soju increased. Lightness of yukwa base was higher than yukwa pellet, but yellowness and redness of yukwa base were lower than yukwa pellet. Air cell size of yukwa base decreased as the ratio of soju increased. The compression and cutting force of yukwa base with 50% ratio of soju addition were lowest, while yukwa base with 0% soju was highest. In the sensory evaluation, preference of color increased as the ratio of soju addition increased. Yukwa base with 50% ratio of soju addition was the highest in internal compactness, mouth-feel, and overall preference. The results show that a soju ratio of 50-75% addition for total liquid is useful in the production of high quality yukwa base.

• Journal of Hydrogen and New Energy
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• v.16 no.2
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• pp.191-198
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• 2005

Adding hydrogen gas in natural gas leads to stable combustion in internal combustion engine and its performances rely on compression ratio. To analyze the effects of compression ratio and rate of hydrogen addition on the engine performance, the characteristics of overall engine performance including emission were investigated by using the medium duty natural gas fueled engine. As results, it was found that compression ratio occurred knock was nearby compression ratio, $\varepsilon$=14 for the case that hydrogen was enriched in the natural gas fueled engine. But slight knock was occurred at $\varepsilon$=14.7 in the case of neat natural gas. Also HC and $CO_2$ were reduced around 80% and 20% respectively when the rate of hydrogen addition was increased to 50% and compression ratio from $\varepsilon$=13 to $\varepsilon$=14.7.