• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.88-89
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• 2020

Research is underway to incorporate water-repellent agents inside mortars to improve the durability of concrete. Therefore, in this study, the mechanical properties and absorption rate were evaluated by adding a hybrid water repellent in which a liquid and a solid were mixed at a constant ratio.As a result of the experiment, the compressive strength of the mortar added with the hybrid water repellent showed a strength reduction of about 5% than the compressive strength of the OPC, and the overall water absorption was lower than that of the water repellent used alone.

• 한국토양비료학회지
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• 제28권2호
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• pp.123-129
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• 1995

Zeolite 광석(鑛石)을 일정(一定) 크기의 입제(粒劑)로 제품화(製品化)하는 과정(過程)에서 생성(生成)되는 다량(多量)의 Zeolite 미분(微粉)의 부가가치(附加價値)를 높이기 위(爲)한 방법(方法)으로 Polyvinyl Alcohol(PVA)을 접착제(接着劑)로 이용(利用)하여 입단화(粒團化)시켰다. 이때에 입단화(粒團化)에 필요(必要)한 PVA의 적정농도(適定濃度)와 조제(調製)한 입상(粒狀)의 물리성(物理性)을 조사(調査)한 결과(結果)는 다음과 같다. 습식사별법(濕式篩別法)에 의(依)한 내수성(耐水性) 입단(粒團)의 함량(含量)은 PVA 0.3% 처리(處理)로 2.0mm 이상(以上)의 Zeolite 입단(粒團)이 98.0%였으며 0.6% 이상(以上) 처리시(處理時)는 거의 100%였다. PVA농도(濃度)가 증가(增加)할수록 수분침투속도(水分浸透速度)와 최대용수량(最大容水量)은 감소(減少)하였고 경도(硬度)는 증가(增加)하였으나 건조온도(乾燥溫度)에 따른 입단(粒團)의 물리성(物理性)에는 거의 변화(變化)가 없었다. Kaolinite와 Bentonite의 혼합비율(混合比率)이 증가(增加)함에 따라 경도(硬度)는 증가(增加)하였으며 이들은 수분함량(水分含量)이 증가(增加)할수록 경도(硬度)는 급격(急激)히 줄어들었다. Smectite와 Perlite의 혼합비율(混合比率)이 증가(增加)함에 따라 경도(硬度)는 낮아졌으나 수분침투속도(水分浸透速度)와 최대용수량(最大容水量)은 증가(增加)하였다.

• Applied Biological Chemistry
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• 제51권1호
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• pp.6-10
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• 2008

Hydrocolloid 로 arabic gum, carboxyl methyl cellulose, pectin을 각각 강력분에 0.2%와 0.5% 첨가하여 반죽의 레올로지 특성 변화를 farinograph, 반죽의 pH, extensograph, fermometer, amylograph 등으로 분석하였다. Hydrocolloid 첨가 시 farinograph에서 흡수율은 증가되었고 CMC 0.5% 첨가시 70.8%로 흡수율이 가장 높았다. 반죽발전시간은 길어졌으나 안정도는 낮아졌다. Hydrocolloid 첨가로 반죽의 pH는 저하되었고 pectin 0.5% 첨가시 가장 낮았다. Extensograph에서 반죽의 저항성은 감소하였고 신장성은 증가하였으며 R/E 값은 낮아졌다. 반죽의 가스발생량은 증가하여 CMC를 0.2% 첨가시 가장 많은 가스를 발생하였다. Amylograph에서 초기호화온도는 $0.5-1.5^{\circ}C$ 싱승하였으나 최고점도온도는 $1-1.5^{\circ}C$ 낮아졌고 최고점도는 높아졌다.

• Geosystem Engineering
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• 제21권6호
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• pp.335-343
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• 2018

Alkali-surfactant polymer flooding has become an important technique to improve oil recovery following the development of oil fields while the function of emulsification in enhanced oil recovery is rarely considered in the existing mathematical model for numerical simulation. In this paper, the mechanism of improving the recovery of the emulsification was analyzed in ASP flooding, and a relatively perfect mathematical model with deep filtration-theory was established, in which oil-water volume equation, saturation equation, viscosity equation, and permeability reduction equation are included. The new model is used to simulate the actual block of an oil field; the simulated results of the new model and an old model without considering the emulsification are compared with the actual well history. It is found that new model which is easy to be realized in numerical simulation has a high precision fitting, and the effect of adding oil and decreasing water is obvious. The sensitivity of emulsification was analyzed, and the results show that the water reducing funnel becomes wider and the rate of water cut decreases rapidly with the increase of emulsifying capacity, and then the rate of recovery slows down. The effect of increasing oil and decreasing water is better, and the degree of recovery increases. The emulsification of the ASP flooding is maintained at a moderate level, which corresponds to ${\Phi}=0.2$ in the new model, and the emulsification is applied to realize the general mathematical quantitative description, so as to better guide the oilfield development.

• 한국건축시공학회지
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• 제7권1호
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• pp.115-121
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• 2007

Ordinary concrete uses aggregate sufficiently soaked with water, and is weighed, mixed with other materials and placed in accord with performances required in the construction field. Recently special concrete with high fluidity and durability is required but it is difficult to use top-quality concrete due to lack of high-quality aggregate, delayed transportation because of traffic jam, etc. In addition, sometimes the use of a remicon is inevitable just for small-sized concrete constructions or it is difficult for a remicon to reach remote construction places such as mountainous areas. To solve these problems, this study attempted to pack concrete materials. In other words, it is to instantize concrete. This study dried aggregate, a material of concrete, and compared the change of absorption phase of the aggregate in water and in paste in order to examine the effect of the dryness of aggregate on its absorption rate and, based on the absorption rate, decided water addition ratio necessary for the reduction of unit quantity caused by the use of dry aggregate in designing concrete mixture, and analyzed the properties of unhardened concrete according to water addition ratio in manufacturing concrete using aggregate in the state of absolute dryness and in the state of surface dryness.

• 한국세라믹학회지
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• 제33권5호
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• pp.479-484
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• 1996

The tribological properties of ceramics are very important in the application to engineering ceramic parts such as mechanical seal slurry valve disc and so on. In this study the effect of graphite addition on the mechanical and tribological properties of RBSC/graphite composites were investigated. The composites were prepared by adding graphite powder to the mixture of SiC powder metallic siliconcarbon black and alumina. Bending strength water absorption friction coefficient the amount of worn out material at a certain time and maximum surface roughness(Rmax) of the prepared composites were measured and crystalline phases were examined with XRD. The composite containing 5 vol% graphite powder showed improved bending strength due to high green density and decreased friction coefficient and wear resistance. The friction coefficient and the wear resistance of the composite were increased by adding graphite powder up to 10 vol% They decreased however as increasing the amount of graphite powder more that 10vol% There was no linear relationship between the tribological properties and bending strength of the composites.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.203-209
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• 2014

Candelilla wax-in-water nanoemulsions stabilized by Span 80/Tween 80 were prepared by the phase inversion composition (PIC) method. Stable nanoemulsions with droplet diameters below 50 nm could be formed when the hydrophilic-lipophilic balance (HLB) values were between 13.5 and 14.5, surfactant concentration was 5.0 wt%, and the surfactant-wax ratio was 1:1. Increased emulsification temperature and cooling rate were found to improve the emulsion properties. Process of PIC (adding aqueous phase to the wax phase) produced smaller droplet size nanoemulsion compared to the process of adding wax phase to the aqueous phase. The stability of these nanoemulsions was assessed by following the change in droplet diameters with time of storage at room temperature (${\sim}25^{\circ}C$). The size remained constant during 2 months storage time.

• 한국식품조리과학회지
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• 제31권1호
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• pp.83-90
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• 2015

This study was performed to evaluate the effects of adding aronia powder on the antioxidant activities and physicochemical properties of pork patties. The patties were prepared by adding 0%, 1%, 2%, and 3% of aronia powder. Water and ethanol were used to extract the antioxidant compounds from aronia. Total phenolic compounds of the water and ethanol extract of aronia were 164.55 mg/g and 221.08 mg/g, respectively. The total phenol contents and DPPH free radical scavenging activity of patties were significantly increased with the increasing amount of aronia powder. Moisture content in control group was 60.61%, and it was significantly different from the aronia powder groups. The cooking loss rate and reduction ratio significantly decreased with the increasing amount of aronia powder. The hardness, chewiness, and gumminess of the control group were lower than those of the treatment group. In the sensory evaluation, the addition of 1% aronia received the best score in appearance, color, and overall preference. We suggest that aronia powder may be a useful ingredient in pork patties to improve the quality characteristics and antioxidant potential.

• 기술사
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• 제33권3호
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• pp.71-79
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• 2000

The effects of alkali salts adding on the cooking quality improving in dried noodles were investigated in the good texture maintaining for preventing solid soluble losses ,through chemical analysis and actual manufacturing practice ,the following results were obtained. Experiments were took a special flour of ASW:DNS=70:30, thickening agent(TA) composed of K2CO3 58%, Na2CO3 36% and Na4P2076%, and emulsified oil(EO) mixing of corn oil 44%, polysorbate 23%, emulsifier(ester of glycerin and fatty acids) 21%, soy lecithin 12%. When the mixing ratio of TA and EO to flour, is 0.03 and 1.5%(w/w) or morel than, satisfied the good quality. The water soluble solid matters content of the lowest 3.2% in the treating group that TA and EO is 0.03 and 1.5%(w/w) respectively, comparing to the 7.3% in the control group provides a excellent cooking quality. The research achieves the similar effects at specific gravity, water absorption ratio, weight increasing rate and volume expansion ratio. According to appearance test the more treating of TA turn the noodle into deeper yellow-green color. Turning to the deeper yellow color according to the increasing of EO provides better

• 한국지역사회생활과학회지
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• 제26권1호
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• pp.127-133
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• 2015

This study identifies the factors improving bread quality by using fermented liquid dough. Fermented liquid dough, the main part of bread dough, contains yeasts that are prepared in order to enhance the fermentation rate. This study investigates the fermentation rate after mixing dough, the pH of dough, loaf volume, water activity, hardness, and sensory properties of loaf bread samples with different amounts of fermented liquid dough. The fermentation rate was slightly higher in the bread samples, the control dough and 10% fermented liquid dough, than in samples with more than 20% dough. The pH values of dough decreased with an increase in the content of fermented liquid dough. The loaf volume of bread with 10% fermented liquid dough was the highest. The water activity of loaf bread increased with an increase in amount of fermented liquid dough. For the sensory evaluation of loaf bread, adding 10% fermented liquid dough improved the loaf volume and evenness of baking. These results suggest that 10% fermented liquid dough increased the fermentation rate and bread quality. Further research is required to enhance internal quality characteristics of loaf bread, including taste and flavor.