• 한국농공학회지
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• 제15권4호
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• pp.3137-3146
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• 1973

This study was to investigate the effects of compaction, compressive strength and Atterberg limits in accordance with the temperatures changes. It was conducted on four soils-KJ, JJ, MH, SS-at temperatures of -1, 1, 3, 5, 7, 10, 15, 19, $22^{\circ}C$. These tests were obtained the maximum dry density and the optimum moisture content of four soils in accordance with temperature changes by using distilled water and $CaCl_2$ 10% solution, and were put to the compressive strength tests on remolded specimens of soils compacted at the optimum moisture content. The result of the study can be summarized as follows; The maximum dry density increased with an increase in temperature, and the use of $CaCl_2$ 10% solution had higher maximum dry density than distilled water. The optimum moisture content decreased with an increase in temperature, and the use of $CaCl_2$ 10% solution had lower optimum moisture content than distilled water. The maximum compressive strength was shown high peak from $7^{\circ}C\;to\;15^{\circ}C$, and the use of $CaCl_2$ 10% solution had higher maximum compressive strength than distilled water. The liquid limit and plasticity index decreased with an increased in temperature. It is estimated that the use of $CaCl_2$ 10% solution can lower the minimum compacted temperature from $2^{\circ}C\;to\;4^{\circ}C$ in low temperature.

• 한국농공학회지
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• 제22권3호
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• pp.60-74
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• 1980

Soil-cement mixtures involve problems in it's durability in grain size distribution and mineral composition of the used soils as well as in cement content, compaction energy, molding water content, and curing. As an attempt to solve the problems associated with durability of weathered granite soil with cement treated was investigated by conducting tests such as unconfined compression test, it's moisture, immers, wet-dry and freeze-thaw curing, mesurement of loss of weight with wet-dry and freeze-thaw by KS F criteria and CBR test with moisture curing on the five soil samples different in weathering and mineral composition. The experimental results are summarized as follows; The unconfined compressive strength was higher in moisture curing rather than in the immers and wet-dry, while it was lowest in freeze-thaw. Decreasing ratio of unconfined compressive strength in soil-cement mixtures were lowest in optimum moisture content or in the dry side rather than optimum moisture content with freeze-thaw. The highly significant ceofficient was obtained between the cement content and loss of weight with freeze-thaw and wet-dry. It was possible to obtain the durability of soil-cement mixtures, as the materials of base for roads, containing above 4 % of cement content, above 3Okg/cm$_2$ of unconfined compressive trength with seven days moisture curing or 12 cycle of freeze-thaw after it, above 100% of relative unconfined compressive strength, 80% of index of resistance, below 14% of loss of weight with 12 cycle of wet-dry and above 1. 80g/cm$_2$ of dry density.

• 한국연초학회지
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• 제15권1호
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• pp.90-97
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• 1993

1. Average moisture content of tobacco in BIB silo was about 19: 1% until 4hours conditioned time, and then moisture variation of tobacco after 2hr conditioned was very small. 2. Application of mathematical model for ordering system. 1) The constant K in the exponential equation varies inversely with both relative humidity and equilibrium moisture. 2) Time needed to order blending tobacco leaves with standard moisture from bulking and blending silo was 4 hours. 3) Reconstituted tobacco sheet had higher moisture absorption ratio than Oriental and Burley tobacco. 4) For minimize of conditioning time in BIB silo, the values of K and Mo given in this study can be used in equation(1) to calculate moisture absorption ratio and optimum conditioning time. 3. Average moisture content and water activity of conditioned tobacco for 4 hours in BIB silo was about 20% and 0.65. In this condition. microbial life will inhibite 4. Physical properties of conditioned tobacco in bulking and blending silo for 4hours was virtually no change.

• 한국농공학회지
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• 제40권4호
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• pp.109-119
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• 1998

Recently pipe-framed greenhouses are widely constructed on domestic farm area. These greenhouses are extremely light-weighted structures and so are easily damaged under strong wind due to the lack of uplift resistance of foundation piles. This experiment was carried out by laboratory soil tank to investigate the displacement be haviors of cylindrical pile foundations according to the uplift loads. Tested soils were sampled from two different greenhouse areas. The treatment for each soil type are consisted of 3 different soil moisture conditions, 2 different soil depths, and 3 different soil compaction ratios. Each test was designed to be repeated 2 times and additional tests were carried out when needed. The results are summarized as follows : 1. When the soil moisture content are low and/or pile foundations are buried relatively shallow, ultimate uplift capacity of foundation soil was generated just after begining of uplift displacement. But under the high moisture conditions and/or deeply buried depth, ultimate up-lift capacity of foundation soil was generated before the begining of uplift displacement. 2. For the case of soil S$_1$, the ultimate uplift capacity of piles depending on moisture contents was found to be highest in optimum moisture condition and in the order of air dryed and saturated moisture contents. But for the case of soil S$_2$, the ultimate uplift capacity was found to be highest in optimum moisture condition and in the order of saturated and air dryed moisture contents. 3. Ultimate uplift capacities are varied depending on the pile foundation soil moisture conditions. Under the conditions of optimum soil moisture contents with 60cm soil depth, the ultimate uplift capacity of pile foundation in compaction ratio of 80%, 85%, and 90% for soil 51 are 76kg, 115kg, and 155kg, respectively, and for soil S$_2$are 36kg, 60kg, and 92kg, respectively. But considering that typical greenhouse uplift failure be occurred under saturnted soil moisture content which prevails during high wind storm accompanying heavy rain, pile foundation is required to be designed under the soil condition of saturated moisture content. 4. Approximated safe wind velosities estimated for soil sample S$_1$and S$_2$are 32.92m/s and 26.58m/s respectively under the optimum soil condition of 90% compaction ratio and optimum moisture content. But considering the uplift failure pattern under saturated moisture contents which are typical situations of high wind accompanying heavy rain, the safe wind velosities for soil sample S$_1$and S$_2$are not any higher than 20.33m/s and 22.69m/s respectively.

• 한국식품조리과학회지
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• 제19권5호
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• pp.571-580
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• 2003

The purpose of this study was to assess the optimum coating ratio for rice, using various ratios of mulberry leaves extract, 1.0, 1.5, and 2.0%, and to determine the optimum ratio of added water, in proportion to the total weight of mulberry rice. The moisture content of the soaked rice, and the optimum water uptake rate, moisture content of the cooked rice, as well as its blue and color values, mechanical characteristics, internal structure and sensory evaluation, were analyzed. The statistical data analyses were completed using the SAS program. The results are summarized as follows: The moisture content of mulberry rice was less than that of raw rice. The average optimum water uptake of the soaked mulberry rice at the different water temperatures, 10, 20 and 30, was 20% of the total weight of the raw mulberry rice. As for the results of the sensory evaluation,; 140% water, in proportion to the total weight of raw mulberry rice, was judged to be the optimum. The average moisture content of the cooked mulberry rice was 45∼50%, but there was no significant difference in the various coating ratios. The blue value of the cooked mulberry rice awas highest on the first day of cooking. The L- and a-values decreased with increasing coating ratio, but the b-value increased under the same conditions. As for the mechanical characteristics,; the adhesiveness, hardness and springiness decreased during 2 days of storage. The internal structure of the mulberry rice, observed by SEM, showed a close structure on increasing the coating ratios of mulberry leaves extracts. It was concluded that the optimum coating ratio of mulberry rice and ratio of added water for cooking wereas 1.5 and 140%, respectively, in proportion to the total weight of raw mulberry rice.

• 한국식품저장유통학회지
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• 제2권2호
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• pp.285-291
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• 1995

This study was performed to investigate the optimum moisture content and the best packaging method of dried persimmons for long term storage at room temperature. The package material to be used were 0.05mm polyethylene film, Wrap film, 0.08mm LDPE film exchanged nitrogen gas, and non package for untreated control. Before the storage, the initial moisture contents of dried persimmons were treated with 40%, 35% and 30%, respectively; 40% as traditional dryness, 35% as extending dry period one more week, and 30% as for two more weeks. The best package method was 0.08mm LDPE film exchanged nitrogen gas, and the optimum moisture control was 35%

• 농업과학연구
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• 제3권2호
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• pp.207-213
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• 1976

최대습윤밀도(最大濕潤密度)로서 함수비시험(含水比試驗)을 하지 않고 직접최적합수비(直接最適合水比)와 최대건록밀도(最大乾綠密度)를 추정(推定)하는 관계식(關係式)을 구(求)하기 위(爲)하여 전국(全國)에서 최근(最近)에 공사(工事)를 실시(實施)하였거나 또는 공사중(工事中)에 있는 157개(個) 지구(地區)의 다짐시험(試驗) 결과(結果)를 분석(分析)하여 다음과 같은 결론(結論)을 얻었다. 최대건조밀도(最大乾燥密度)와 최적합수비(最適合水比)의 사이에는 ${\gamma}=0.9636$의 높은 상관성(相關性)을 나타냈고 ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$의 관계식(關係式)을 얻었다. 최적합수비(最適合水比)에 대응(對應)하는 습윤밀도(濕潤密度)와 최적합수비(最適合水比)는 $W_{opt.}={\frac{1-0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$의 관계식(關係式)을 얻었고 최대습윤밀도(最大濕潤密度)(${\gamma}_{tmax}$)로 추정(推定)한 최적합수비(最適合水比)는 실측치(實測値)와 큰 차이(差異)가 없었다. 최대습윤밀도(最大濕潤密度)로 추정(推定)한 함수비(含水比)에 의하여 최대건조밀도(最大乾燥密度)를 추정(推定)한 결과실측치(結果實測値)와의 오차(誤差)는 ${\pm}5%$내(內)에 속했다. 최대건조밀도(最大乾燥密度)와 공극비(空隙比)는 ${\gamma}=0.9706$의 높은 상관성(相關性)이 인정(認定)되고 ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$의 관계식(關係式)을 얻었다.

• 동아시아식생활학회지
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• 제1권3호
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• pp.305-311
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• 1991

The study was designed to investigate overall acceptability of rice extrudate with added ginseng flour extruded by single screw extruder. Graphic three dimension analysis on response surface regression was conducted for overall acceptability evaluated by balanced incomplete block design. Overall acceptability, which formed a saddle point, increased as moisture content increased at lower die temperature, and as moisture content decreased at higher die temperature. Critical values of each variable which indicated optimum response are 5.0% ginseng content, 17.8% moisture content and 104.6$^{\circ}C$ die temperature, and optimum inferred score of overall acceptability is 59.6 and 90. Key words: extrdate, overall acceptability, response surface regression analysis, balanced incomplete block method.

• 한국건설순환자원학회논문집
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• 제4권3호
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• pp.276-283
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• 2016

레드머드는 보오크사이트 원광석에서 생산되는 알루미나의 선광과정에서 발생되는 무기질 부산물이다. 인 레드머드를 활용하고자 하는 연구가 국내에서 이루어지고 있다. 강알카리성의 레드머드를 건설산업용 촉진제로서 활용하고자 하는 연구로서 알칼리활성화 슬래그-레드머드 시멘트가 국내외적으로 발표되고 있다. 본 논문은 순환골재 대체율에 따른 알칼리활성화 슬래그-레드머드 건식 흙포장재의 최적함수율, 압축강도, 흡수율, 백화발생 특성에 대하여 비교 검토하였다. 그 결과 순환골재 대체율이 증가할수록 알칼리활성화 슬래그-레드머드 흙포장재의 최적 함수비, 물흡수계수, 백화면적은 증가하고 압축강도는 감소하였다.

• Journal of Ginseng Research
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• 제34권1호
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• pp.59-67
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• 2010

Response surface methodology was used to predict the optimum conditions of explosive puffing process for ginseng. A central composite design was used to monitor the effect of moisture content and puffing pressure on dependent variables such as functional compounds (extract yield, crude saponin, acidic polysaccharide, and total phenolic content) and sensory properties. Correlation coefficients $(R^2)$ of models for crude saponin, acidic polysaccharide, and total phenolic content were 0.9176 (p<0.05), 0.9494 (p<0.05), and 0.9878 (p<0.001), respectively. Functional compounds increased with decreasing moisture content and increasing puffing pressure. Overall palatability was high at 15-20% moisture content and 98-294 kPa of puffing pressure. On the basis of superimposed contour maps for functional compounds and overall palatability of puffed ginseng, the optimum ranges of puffing conditions were 10-17% moisture content and 294-392 kPa puffing pressure.