• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.1
• /
• pp.46-51
• /
• 2004

The film coated snap bean (Phaseolus vulgaris) seeds with five different coating materials treated with 3% increase in seed weight were planted at sandy loam soil controlled moisture content of 18, 19, 20 and 21 %. The oxygen diffusion rate (ODR) was calculated from the different moisture content soil. The number of normal seedlings, seedling vigor, and seedling capability in field (seed vigor x dry matter weight) were observed at 9 days after planting and compared to the changes of ODR. The germination rate and ODR were sharply decreased simultaneously in the seeds planted at 21 % soil moisture content. Seedling emergence did not occur at all as the soil moisture content increased above 22 %. Hence this value should be considered as the threshold of soil moisture content for seedling emergence. An ODR value under 20% did not influence the percent emergence significantly. The certain difference observing in the emergence at the same ODR was not related clearly to the condition of soil. So it can be assumed that the limit of soil moisture content for the emergence of snap bean was approximately 20%. The value of 18% soil moisture content may be considered as the optimum for snap bean emergence. There was close relationship between the mean value of ODR in different soil moisture contents and the emergence. The germination rates of the seeds coated with the different materials were quite different when the seeds were planted at 21 % soil moisture. Dry weight of the seedlings from film coated seeds was decreased slightly, but the germination rates were not much different from the non-treated control under relatively higher soil moisture content (21 %). Major factor lowering emergence rate was oxygen stress while film coating act as a minor constraint for snap bean sown in excess soil moisture condition.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.2
• /
• pp.215-221
• /
• 1984

To investigate stability for the quality of selected ginseng products, their sorption properties were clarified in red ginseng extract(RGEP), and red ginseng extract powder(RGEP), and red ginseng extract tea(RGET). Simultaneously, the BET monolayer value of each product was determined in order to inquire out the possibility of establishment as a criterion for the optimum moisture content of the ginseng products. Based on the BET monolayer moisture level of spray dried RGEP which ranged from 4.08 to 4.65%, it would be desirable to establish the optimum moisture content of the products at 4.4${\pm}$0.3%. This is 1.3 to 1.9% lower than the criter on, "less than 6.0%". The optimum moisture level for RGET of which monolayer value ranged 0.93 to 1.37% would be 1.2${\pm}$0.17%. In this case, the maximum permissible limit of moisture content could presumably be raised up to 1.37% in place of current criterion, "less than l.2%". From the results of a study on the growth of molds, the optimum moisture content for RGE assumed to be extended up to 40.0${\pm}$1.07 despite 36.0${\pm}$1.0% of the present criterion. On the other hand, a storage study under the maltreated condition, $48{\pm}2^{\circ}C$ 75%RH, was also carried out in order to make it clear whether the BET monolayer values were able to be used as indices for optimum moisture level of the products. In all samples tested adsorption occurred at even higher levels of moisture than the monolayer values. However, since there are many other possible factors affecting the quality of products the optimum moisture content is preferable to be reduced to the monolayer value. As a result, it was proved that the optimum level of moisture for both RGEP and RGET could be established by the monolayer values.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.47 no.3
• /
• pp.49-56
• /
• 2005

This study was conducted by the tests of materials engineering and soil mechanics to see the strength characteristics of the ‘Cement-Mixed Soil'. To sum up my experiments, I would like to present the results which are the theoretical base and fundamental data to establish the standard design including the design of mixing proportions of the soil as a construction material. In conclusion, in this study the optimum cement mixing ratio is $9\%$ and in this ratio the optimum moisture content of compaction work is $19.3\%$ from the analysis of the strength characteristics, as well as in consideration of the economic profits and nature familiar facts.

• International Journal of Highway Engineering
• /
• v.20 no.1
• /
• pp.69-76
• /
• 2018

PURPOSES : This study determined the optimal usage rate of RAP (reclaimed asphalt pavement) using cold central-plant recycling (CCPR) on a road-surface layer. In addition, a mixture-aggregate gradation design and a curing method based on the proposed rate for the surface-layer mix design were proposed. METHODS : First, current research trends were investigated by analyzing the optimum moisture content, mix design, and quality standards for surface layers in Korea and abroad. To analyze the aggregate characteristics of the RAP, its aggregate-size characteristics were analyzed through the combustion asphalt content test and the aggregate sieve analysis test. Moreover, aggregate-segregation experiments were performed to examine the possibility of RAP aggregate segregation from field compaction and vehicle traffic. After confirming the RAP quality standards, coarse aggregate and fine aggregate, aggregate-gradation design and quality tests were conducted for mixtures with 40% and 50% RAP usage. The optimum moisture content of the surface-layer mixture containing RAP was tested, as was the evapotranspiration effect on the surface-layer mixture of the optimum moisture content. RESULTS : After analyzing the RAP recycled aggregate size and extraction aggregate size, 13-8mm aggregate was found to be mostly 8mm aggregate after combustion. After using surface-chipping and mixing methods to examine the possibility of RAP aggregate segregation, it was found that the mixing method contributed very little for 3.32%, and because the surface-chipping method applied compaction energy directly as the maximum assumption the separation ratio was 15.46%. However, the composite aggregate gradation did not change. Using a 40% RAP aggregate rate on the surface-layer mixture for cold central-plant recycling satisfied the Abroad quality standard. The optimum moisture content of the surface-layer mixture was found to be 7.9% using the modified Marshall compaction test. It was found that the mixture was over 90% cured after curing at $60^{\circ}C$ for two days. CONCLUSIONS : To use the cold central-plant recycling mixture on a road-surface layer, a mixture-aggregate gradation design was proposed as the RAP recycled aggregate size without considering aggregate segregation, and the RAP optimal usage rate was 40%. In addition, the modified Marshall compaction test was used to determine the optimum moisture content as a mix-design parameter, and the curing method was adapted using the method recommended by Asphalt Recycling & Reclaiming Association (ARRA).

• Journal of Biosystems Engineering
• /
• v.26 no.5
• /
• pp.469-474
• /
• 2001

Milling the rice with low moisture requires more energy, produces more cracked rice, and results in reducing taste of cooked rice. Accordingly, it is necessary to add moisture to the rice with low moisture to obtain optimum moisture level for milling and taste of rice. This study was performed to evaluate the influence of initial moisture content and absorption rate on rice crack, milling energy and whiteness of milled rice and to obtain the information for design of rewetting system mounted on stirring device in grain bin. The tests were conducted for the four levels of initial moisture content in the range of 11.4 to 14.5%(w.b.) and six levels of absorption rate in the range of 0.04 to 1.0%, w.b./hr. In the case of lower moisture content below 12%(w.b.), crack ratios of brown rice were remarkably high regardless of initial moisture contents. Therefore, it was found that rough rice below 12%(w.b.) in initial moisture content could not rewetted by spraying water without crack generation of low level. Absorption rate must be below 0.3%, w.b./hr to maintain crack ratio increase of less than 1% regardless of initial moisture contents. In the case of allowable crack ratio increase of 2% and 5%, it was found that the maximum absorprion rate was respectively 0.6%, w.b./hr and 1.0%, w.b./hr in the initial moisture content of above 13.5%(w.b.). Rewetting the rough rice in moisture content of 11.4 to 14.5%(w.b.) to 14.3 to 16.9%(w.b.) decreased milling energy consumption by 15.9 to 22.3%. The effect of energy saving was higher in the samples of higher initial moisture content. Whiteness of milled rice was decreased by 0.5 to 1.5.

• Applied Chemistry for Engineering
• /
• v.25 no.4
• /
• pp.409-413
• /
• 2014

This study was carried out to design the optimum mixing ratio of aggregate, cyclic aggregate, and binder (moisture, emulsified asphalt, and emulsion type additives) and produce recycling cold asphalt paving mixture satisfying site work standard. The cyclic aggregate satisfying KS F 2572 was collected from waste asphalt by adequate processing. As the moisture content increased, the shearing strength was decreased. The maximum marshall stability was shown at the 3.0 wt% moisture content. So the optimum moisture content was 3.0 wt%. The marshall stability and flow value with the amount of emulsified asphalt was satisfied in the range of 0.5~2.5 wt%, and the porosity was satisfied in the range of 0.7~2.5 wt%. So the optimum amount of emulsified asphalt was 1.6 wt%. The optimum amount of emulsion type additive was 0.1 wt% in the light of marshall stability and degree of saturation of recycling cold asphalt mixture.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.370-374
• /
• 2001

This study was performed to find the basic data, as needed on the reinforced clayey soil construction work, by estimating job difficulty and optimum moisture content of the reinforced clayey soil, according to its slump test and workability test. As a result, it has been found that the more increasing reinforced clayey soil's moisture content, the higher its slump value. Its 25% moisture content: the reinforced clayey soil except the fiber reinforced soil was able to work with hand; the fiber reinforced soil with the 0.5% or 1.0% of fiber ratio was poor cohesion because of surplus quantity of fiber. Its moisture content between 30% and 35%: shoveling is somewhat difficult but troweling is possible. This study will be needed to modify and add by another.

• Food Science and Preservation
• /
• v.6 no.1
• /
• pp.55-60
• /
• 1999

A three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of banana. The moisture loss, solid gain, weight loss and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Color difference and titratable acidity were decreased by higher concentration. Sweetness was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. The regression models showed a significant lack of fit (p>0.5) and were highly significant with satisfying values of R2. To optimize osmotic dehydration, based on surface response and contour plots, superimposing the individual contour plots for the response variables. the optimum conditions for this process wire 26$^{\circ}C$, 44 $^{\circ}$brix and 2 hrs for moisture content, sweetness and color difference are less than 72%, 24 obrix and 10 degree.

• Food Science and Biotechnology
• /
• v.18 no.4
• /
• pp.985-990
• /
• 2009

Response surface methodology (RSM) was applied to determine the optimum drying conditions for pork jerky. The physicochemical properties of pork jerky, such as final moisture content, water activity (Aw), pH, and shear force were investigated. In addition, sensory characteristics of pork jerky were evaluated and were used as a parameter for determining the optimum condition. Pork jerky samples were dried at different temperatures between 40 to $80^{\circ}C$ for the time ranged from 0 to 10 hr. The predicted values for moisture content, Aw, and shear force of dried pork samples were in good agreement with the experimental values with correlation coefficients ($R^2$) of 0.95, 0.96, and 0.97, respectively. Both drying temperature and time significantly (p<0.01) affected moisture content, Aw, pH, and shear force and their interactions were also significant at p<0.01 except for Aw. RSM showed the optimum drying conditions for pork jerky, based on moisture content, shear force, and sensory evaluation to be oC$65-70^{\circ}C$ for 7-8 hr.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.315-316
• /
• 2001

In this study various nutritional and environmental parameters such as, initial moisture content, pH. inoculum size, air rate, sample size and nutrient supplement that influence pigment production were evaluated in solid-state cultures. optimum initial moisture content and pH were determined to be 50% and 6.0, respectively. The supplement of the substrate with different carbon, nitrogen, and mineral source reveals a more inhibitive effect as the substrate concentration increase. optimum aeration rate was determined to be 2vvm in flask culture. The maximum amount of red pigment, 3500 OD/g dried fermented rice, was obtained in optimum conditions which is obtained in solid flask culture.