• 한국농공학회지
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• 제26권1호
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• pp.52-72
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• 1984

This study was performed to obtain the basic data which can be applied to the use of epoxy resin mortars. The data was based on the properties of epoxy resin mortars depending upon various mixing ratios to compare those of cement mortar. The resin which was used at this experiment was Epi-Bis type epoxy resin which is extensively being used as concrete structures. In the case of epoxy resin mortar, mixing ratios of resin to fine aggregate were 1: 2, 1: 4, 1: 6, 1: 8, 1:10, 1 :12 and 1:14, but the ratio of cement to fine aggregate in cement mortar was 1 : 2.5. The results obtained are summarized as follows; 1.When the mixing ratio was 1: 6, the highest density was 2.01 g/cm$^3$, being lower than 2.13 g/cm$^3$ of that of cement mortar. 2.According to the water absorption and water permeability test, the watertightness was shown very high at the mixing ratios of 1: 2, 1: 4 and 1: 6. But then the mixing ratio was less than 1 : 6, the watertightness considerably decreased. By this result, it was regarded that optimum mixing ratio of epoxy resin mortar for watertight structures should be richer mixing ratio than 1: 6. 3.The hardening shrinkage was large as the mixing ratio became leaner, but the values were remarkably small as compared with cement mortar. And the influence of dryness and moisture was exerted little at richer mixing ratio than 1: 6, but its effect was obvious at the lean mixing ratio, 1: 8, 1:10,1:12 and 1:14. It was confirmed that the optimum mixing ratio for concrete structures which would be influenced by the repeated dryness and moisture should be rich mixing ratio higher than 1: 6. 4.The compressive, bending and splitting tensile strenghs were observed very high, even the value at the mixing ratio of 1:14 was higher than that of cement mortar. It showed that epoxy resin mortar especially was to have high strength in bending and splitting tensile strength. Also, the initial strength within 24 hours gave rise to high value. Thus it was clear that epoxy resin was rapid hardening material. The multiple regression equations of strength were computed depending on a function of mixing ratios and curing times. 5.The elastic moduli derived from the compressive stress-strain curve were slightly smaller than the value of cement mortar, and the toughness of epoxy resin mortar was larger than that of cement mortar. 6.The impact resistance was strong compared with cement mortar at all mixing ratios. Especially, bending impact strength by the square pillar specimens was higher than the impact resistance of flat specimens or cylinderic specimens. 7.The Brinell hardness was relatively larger than that of cement mortar, but it gradually decreased with the decline of mixing ratio, and Brinell hardness at mixing ratio of 1 :14 was much the same as cement mortar. 8.The abrasion rate of epoxy resin mortar at all mixing ratio, when Losangeles abation testing machine revolved 500 times, was very low. Even mixing ratio of 1 :14 was no more than 31.41%, which was less than critical abrasion rate 40% of coarse aggregate for cement concrete. Consequently, the abrasion rate of epoxy resin mortar was superior to cement mortar, and the relation between abrasion rate and Brinell hardness was highly significant as exponential curve. 9.The highest bond strength of epoxy resin mortar was 12.9 kg/cm$^2$ at the mixing ratio of 1:2. The failure of bonded flat steel specimens occurred on the part of epoxy resin mortar at the mixing ratio of 1: 2 and 1: 4, and that of bonded cement concrete specimens was fond on the part of combained concrete at the mixing ratio of 1 : 2 ,1: 4 and 1: 6. It was confirmed that the optimum mixing ratio for bonding of steel plate, and of cement concrete should be rich mixing ratio above 1 : 4 and 1 : 6 respectively. 10.The variations of color tone by heating began to take place at about 60˚C, and the ultimate change occurred at 120˚C. The compressive, bending and splitting tensile strengths increased with rising temperature up to 80˚ C, but these rapidly decreased when temperature was above 800 C. Accordingly, it was evident that the resistance temperature of epoxy resin mortar was about 80˚C which was generally considered lower than that of the other concrete materials. But it is likely that there is no problem in epoxy resin mortar when used for unnecessary materials of high temperature resistance. The multiple regression equations of strength were computed depending on a function of mixing ratios and heating temperatures. 11.The susceptibility to chemical attack of cement mortar was easily affected by inorganic and organic acid. and that of epoxy resin mortar with mixing ratio of 1: 4 was of great resistance. On the other hand, when mixing ratio was lower than 1 : 8 epoxy resin mortar had very poor resistance, especially being poor resistant to organicacid. Therefore, for the structures requiring chemical resistance optimum mixing of epoxy resin mortar should be rich mixing ratio higher than 1: 4.

• Journal of the Optical Society of Korea
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• 제15권1호
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• pp.96-102
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• 2011

Simultaneous measurements using a scanning spectrograph system and transmissometer were performed for the first time over an urban site in Gwangju, Korea, to derive the ambient $NO_2$ volume mixing ratio. The differential slant column densities retrieved from the scanning spectrograph system were converted to volume mixing ratios using the light traveling distance along the scanning line of sight derived from the transmissometer light extinction coefficients. To assess the performance of this system, we compared the derived $NO_2$ volume mixing ratios with those measured by an in situ chemiluminescence monitor under various atmospheric conditions. For a cloudless atmosphere, the linear correlation coefficient (R) between the two data sets (i.e., data derived from the scanning spectrograph and from the in situ monitor) was 0.81; the value for a cloudy atmosphere was 0.69. The two sets of $NO_2$ volume mixing ratios were also compared for various wind speeds. We also consider the measurement errors, as estimated from an error propagation analysis.

• 농업과학연구
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• 제14권2호
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• pp.373-383
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• 1987

이 연구(硏究)는 no-fines concrete의 배합비(配合比)와 물-시멘트비(比)에 따른 강도특성(强度特性)을 구명(究明)함으로써, 이의 효과적(效果的)인 사용(使用)을 위한 기초적(基礎的)인 자료(資料)를 마련하는데 있으며, 이 연구(硏究)에서 얻어진 결과(結果)를 요약(要約)하면 다음과 같다. 1. Consistency의 적정(滴定)한 물-시멘트비(比)는 시멘트와 조골재(粗骨材)의 배합비(配合比)가 클수록 증가(增加)하는 경향(傾向)을 보였다. 2. 압축(壓縮)과 인장강도(引張强度)는 각(各) 배합비별(配合比別) consistency의 적합(適合)한 물-시멘트비(比)에서 최대강도(最大强度)가 나타났고, 보통(普通)시멘트 콘크리트에 비(比)하여 1:4 배합(配合)에서는 비슷한 강도(强度)를 나타내었으나 배합비(配合比)가 증가(增加) 할수록 강도(强度)가 현저히 저하(低下)하는 경향(傾向)을 보였다. 3. 압축(壓縮)과 인장강도(引張强度)와의 상관관계(相關關係)는 직선형(直線形)으로서 고도(高度)의 유의성(有意性)이 있었으며 이들의 강도비(强度比)는 재령(材齡)이 증가(增加) 할수록 증가(增加)하였고, 배합비(配合比)가 클수록 감소(減少)하였으며, 보통(普通)시멘트 콘크리트보다는 작게 나타났다. 4. 밀도(密度)는 배합비(配合比)가 증가(增加) 할수록 감소(減少)하는 경향(傾向)을 보였으며, 보통(普通)시멘트 콘크리트에 비(比)하여 배합비(配合比) 1:4에서는 근사(近似)한 값을 나타내었으나 배합비(配合比)가 증가(增加) 할수록 감소(減少)하는 경향(傾向)을 보였다. 5. 강도(强度)와 밀도(密度)와의 상관관계(相關關係)는 직선형(直線形)으로서 고도(高度)의 유의성(有意性)이 인정(認定)되었고, 밀도(密度)의 감소율(減少率)보다는 강도(强度)의 감소율(減少率)이 더 크게 나타나는 경향(傾向)을 보였다.

• 한국식품조리과학회지
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• 제25권2호
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• pp.260-265
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• 2009

The influence of mixing ratio of 25 commercial rice varieties was evaluated by DNA analysis and Toyo value palatability. No relationship was evident between rice palatability and various grain quality properties, or between palatability and mixing ratio. A positive relationship was evident between palatability and texture and between palatability and chalky rice ratio. A negative relationship was evident between mixing ratio and amylose content.

• 한국식품영양학회지
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• 제29권4호
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• pp.513-520
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• 2016

Recently, the incidence of cardiovascular diseases including high blood pressure and heart disease has increased with increased meat consumption in Korea. This study was performed to determine the optimal mixing ratio among ratios of 0, 1:0, 0:1, 1:1, 2:1, and 1:2 of mulberry leaf powder to mulberry fruit powder based on the anti-inflammatory effects. Then, the quality characteristics of the sauce for meat prepared with different mixing ratios (0, 1:1, 1:2, 1:3, 1:4, and 1:5) of mulberry leaf powder to mulberry fruit powder were assessed. The inhibitory effects of ML2MF1 (2:1 ratio of mulberry leaf powder to mulberry fruit powder) on NO and TNF-${\alpha}$ production were superior to those of other mixing ratios. With respect to color values of the sauce for meat prepared with different mixing ratio of mulberry leaf powder to mulberry fruit powder, as the mulberry fruit powder mixing ratios was increased, redness was increased but lightness and yellowness were decreased. The sensory evaluation of ML1MF5S (1:5 ratio of mulberry leaf powder to mulberry fruit powder) sauce for meat showed the highest score with respect to color, smell, taste, harmony with meat and the overall preference. In conclusion, as the mulberry leaf powder mixing ratio was increased, the anti-inflammatory activities were increased. But sensory evaluation scores were increased as the mulberry fruit powder mixing ratio was increased. Therefore, by performing further study, the method to increase mulberry leaf powder in the mixing ratio for improving the sensory evaluation should be provided.

• 한국분무공학회지
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• 제15권4호
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• pp.177-181
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• 2010

This paper has designed a mixing enhancement apparatus called Lobed-plate and Step-plate and comparatively calculated desulfurization efficiency of when its shape was changed. The parameters used at this time were the shape, SR ratio and the number of nozzles of the mixing enhancement apparatus and comparatively analyzed desulfurization efficiency according to these parameters. As a result, the Step-plate appeared as more highly by around 4% than Lobed-plate in desulfurization efficiency according to the shape of the mixing promotion apparatus, and when the desulfurization efficiency as a SR ratio is considered, it appeared highly by an average of 5% when the SR ratio is 3 rather than 2. As a result of comparing desulfurization efficiency by fixing the SR ratio and setting the number of nozzles as 4 pieces and 6 pieces, there was no big change in desulfurization efficiency when the SR ratio is 2, but it could be confirmed to improve by around 5% when the SR ratio is 3 when time passed 8 seconds.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.382-387
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• 1998

Triaxial compression tests were run to study on the undrained strength characteristics of fiber mixed kaolin clay(Hadong). The influence of various test parameters such as amount and aspect ratio(ratio of length to diameter) of fiber, confining stress was also investigated. Test results showed that the increase in aspect ratio was increased in deviator stress at failure, but no effect on pore water pressure at failure. Deviator stress at failure was also increased at 0.5％ mixing ratio(weight fraction of fiber to that of soil solid) of fiber but it was, thereafter, decreased and wits reached to constant after 2％ mixing ratio. On the contrary, Pore water pressure at failure was increased as mixing ratio of fiber was greater than 1%. Deviator stress and pore water pressure of both clay and fiber mixed clay(FMC) at failure were increased as confining stress was increased. Deviator stress of FMC at failure was about 10％ larger than that of clay, but pore water pressure of FMC at failure was almost similar to that of clay.

• KSTLE International Journal
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• 제1권2호
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• pp.76-82
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• 2000

Turbulence in journal bearing operation is examined and the thermal variability is studied for isothermal, convective and adiabatic conditions on the walls under aligned and misaligned conditions. Also, the effects of a contraction ratio at the cavitation region and the mixing between re-circulating oil and inlet oil on the fluid field of oil film are included. An algorithm for the solution of the coupled turbulent Reynolds and energy equations is used to examine the effects of the various factors. Heat convection is found to play only a small role in determining friction and load under no mixing condition. However, under realistic mixing condition, the heat convection cannot be ignored. The wall temperature and heat transfer have been found to be of secondary important factors to the mixing effectiveness at the groove and the final mixture temperature.

• 한국지반신소재학회논문집
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• 제16권2호
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• pp.47-54
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• 2017

본 연구에서는 바이오주입재를 시멘트와 같은 분말 형태로 주입재를 개발하였다. 바이오그라우팅의 배합비를 선정하기 위해 규산소다 3호 : 물의 비율(50 : 50, 35 : 65, 20 : 80), 시멘트 : 바이오주입재의 비율(100 : 0, 90 : 10, 70 : 30)로 각각 샌드겔 공시체를 제작하여 시간 경과에 따른 geltime을 분석하였다. 그리고 geltime에 따른 일축압축강도를 평가하여 시공조건에 맞는 배합비를 선정할 수 있도록 제시하였다. 실내실험 결과, 규산소다 3호 : 물의 비율이 35 : 65, 시멘트 : 바이오주입재의 비율이 90 : 10일 때 겔타임과 일축압축강도가 잘 나타나 적정한 최적배합비로 확인하였다.

• Transactions on Electrical and Electronic Materials
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• 제18권2호
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• pp.74-77
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• 2017

In this work, we investigated the etching characteristics of TaNO thin films and the selectivity of TaNO to $SiO_2$ in an $O_2$/CF4/Ar inductively coupled plasma (ICP) system. The maximum etch rate of TaNO thin film was 297.1 nm/min at a gas mixing ratio of O2/CF4/Ar (6:16:4 sccm). At the same time, the etch rate was measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment, as well as the accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CF_4$-containing plasmas.