• 제목/요약/키워드: Moisture ratio

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Study on the Growth and the Drought Resistance of Amorpha fructicosa under the Control of Water Supply (수분공급조절에 의한 족제비싸리의 생장과 내건성에 관한 연구)

  • Hong, Kyung-Hae;Kim, Woen
    • The Korean Journal of Ecology
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    • v.5 no.2_3
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    • pp.123-131
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    • 1982
  • The growth and the resistance of Amorpha fructicosa L. under water control was experimented in frames out of doors. The plant grew in a wagner's pot under water control. The soil moisture content was controlled at 5%, 10%, 15% and 20%. The growth of leaf, stem and root in the groups of 5% and 10% soil moisture content were different from values in the groups of 15% and 20%. The T/R ratio in the groups of 5% and 10% soil moisture content were different from the ratio in the groups of 15% and 20% soil moisture content. The T/R ratio of former was lower than the latter, but the C/F ratio of the former was higher than the latter. RGR and NAR of Amorpha fructicosa decreased in 5% and 10% soil moisture content but increased in 15% and 20% soil moisture content during growing period. The maximum values of RGR and NAR were respectively 0.089 and 0.080 at 20% soil moisture content. The highest value of LAR was 1.560 at 5% soil moisture content. RGR and NAR were comparatively affected by soil moisture content.

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A Study on Conditioning of the Brown Rice (II) -Milling characteristic with eight hours′ripeness after conditioning moisture content- (현미 조절에 관한 연구(II) -함수율 조질 후 8시간 숙성에 따른 정백특성-)

  • 한충수;강태환;조성찬;고학균
    • Journal of Biosystems Engineering
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    • v.27 no.1
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    • pp.51-58
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    • 2002
  • The goal of this research was to an optimum conditions for the brown rice conditioning from data of milling characteristics after conditioning of the brown rice. The range of the initial moisture content of the sample was 13%, 14%, and 15%, the range of the increment of the moisture content was 0.4% and 0.8% with respect to the initial moisture content, and a ripe time after conditioning was eight hours. The results obtained from this research can be summarized as fellows. 1 The crack ratio after conditioning the brown rice with the initial moisture content was increased as the initial moisture content decreased and increment of the moisture content increased. The crack ratio of the milled rice was increased than that of the non-conditioned brown rice and decreased with the conditioned brown rice with the increment of the moisture content of 0.4% and 0.5%. 2. The broken rice ratio after conditioning the brown rice with the initial moisture content was a little higher than that of the non-conditioned brawn rice. The broken ratio of the conditioned brown rice with the increment of the moisture content of 0.4% was increased around 0.2∼0.4% with respect to the non-conditioned brown riced and the broken ratio of the brown rice was high with increased amount of water sprayed during conditioning process. 3. The moisture content of the milled rice after conditioning the brown rice with the initial moisture content increased around 0.3∼0.8% with respect to the non-conditioned milled rice. 4. The electric energy consumption on milling process with the conditioned brown rice by the initial moisture content was decreased 3.4∼39.1% with respect to the non-conditioned brown rice.

Studies on Absorption Ratio of Tobacco for Optimum Moisture Control (적정수분 관리를 위한 담배흡습속도에 관한 연구)

  • 정한주;김기환;민영근;김병구;양광규;오인혁
    • Journal of the Korean Society of Tobacco Science
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    • v.15 no.1
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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.

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Mechanecal Prolperties of Concerte as the Condition of Contained Water (함수상태에 따른 콘크리트의 역학적성상)

  • 김인수;오창희
    • Magazine of the Korea Concrete Institute
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    • v.4 no.1
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    • pp.127-134
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    • 1992
  • Generally speaking, the internal moisture of concrete is mainly distributed in inner part and concrete surface which is exposed are dned according to influence of temperature and humidity. So, the properties which are compressive strength, modular elasticity, and volume change are different at each part even in same concrete. This is because moisture distribution is changed according to the evaporation and move ment of moisture, exist in the inner porosity of concrete. Therefore, it is necessary that we investigate the properties of concrete according to moisture distribution. The purpose of this study is investigating correlation between the moisture content and mechanical properties in concrete. Compressive and tenslle strength decrease according to increasing moisture content, but modular elas ticity increase. Those increasing or decreasing ratio at drying ratio 100% (absolute dries) is as follows in comparative of drying ratio 0 % (saturated condition).tion).

Analysis of Fuel Moisture Contents Change after Precipitation in the Pine tree stand during Forest Fire Period in the East sea region (영동지역 소나무림에서 강우 후 임내 연료습도 변화분석)

  • Lee, Si-Young;Lee, Myung-Woog;Kwon, Chun-Geun;Yeom, Chan-Ho
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.149-152
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    • 2008
  • This study is the result between the variation of fuel moisture and the risk of forest fire through measuring the change of moisture containing ratio on-site and its average analysis for fallen leaves layer, humus layer, and soil layer in the forest. The measurement was performed on six days from the day after a rainfall. The fuel moisture on-site was measured on the day when the accumulated rainfall was above 5.0mm, and the measurements was 2 times in spring and 1 time in fall. From the pine forest which were distributed around Samcheok and Donghae in Kangwondo, three regions were selected by loose, medium, and dense forest density, and the fuel moisture was measured on fallen leaves layer, humus layer, and soil layer in the forest. for six days from the day after a rainfall. The study showed that the moisture containing ratio converged on 3 - 4 days in spring and fall for fallen leaves layer, and the convergence was made more than six days in spring and fall for the humus layer. In the other case of soil layer, the variation of moisture containing ratio after rainfall was not distinguishable regardless of season.

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Effects of Pellet Moisture Content on the Physical Properties of Vacuum-puffed Yukwa

  • Shen, Xiao-Jun;Norajit, Krittika;Ryu, Gi-Hyung
    • Food Engineering Progress
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    • v.15 no.3
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    • pp.262-268
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    • 2011
  • The effects of pellet moisture content on physical properties (expansion ratio, density and breaking strength) of vacuum-puffed Yukwa (non-oil puffed Yukwa) were investigated in this study. The Yukwa was made from the waxy rice steeped at 25 and $30^{\circ}C$ for 3, 5 and 10 days with pellet drying times (6, 8 and 10.5 hr). As the drying time increased from 6 to 10.5 hr at $50^{\circ}C$, the highest value of pellet moisture content (29.4%) was found in the samples made from the steeped waxy rice at $25^{\circ}C$ for 5 days after 6 hr drying, while the lowest value (16.3%) was found at $25^{\circ}C$ for 3 days after 10.5 hr drying. Both redness and yellowness values of vacuum-puffed Yukwa increased as the drying time increased. The expansion ratio of Yukwa was greatly affected by drying time, ranging from 2.07 (26.8% pellet moisture content) to 7.01 (24.0% pellet moisture content). From the data, it can be concluded that the pellet moisture content had a significant influence on the physical characteristics of vacuum-puffed Yukwa. With vacuum puffing condition of 3 min heating and 2 min puffing, the pellets with about 25% moisture content showed higher expansion ratio, and lower density and breaking strength.

Using Lamb Waves to Monitor Moisture Absorption in Thermally Fatigued Composite Laminates

  • Lee, Jaesun;Cho, Younho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.36 no.3
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    • pp.175-180
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    • 2016
  • Nondestructive evaluation for material health monitoring is important in aerospace industries. Composite laminates are exposed to heat cyclic loading and humid environment depending on flight conditions. Cyclic heat loading and moisture absorption may lead to material degradation such as matrix breaking, debonding, and delamination. In this paper, the moisture absorption ratio was investigated by measuring the Lamb wave velocity. The composite laminates were manufactured and subjected to different thermal aging cycles and moisture absorption. For various conditions of these cycles, not only changes in weight and also ultrasonic wave velocity were measured, and the Lamb wave velocity at various levels of moisture on a carbon-epoxy plate was investigated. Results from the experiment show a linear correlation between moisture absorption ratio and Lamb wave velocity at different thermal fatigue stages. The presented method can be applied as an alternative solution in the online monitoring of composite laminate moisture levels in commercial flights.

A Study on Moisture Transport of Artificial Lightweight Concrete (인공경량골재 콘크리트의 수분이동 특성에 관한 연구)

  • Lee, Chang Soo;Choi, Sang Hyun;Park, Jong Hyok;Kim, Young Ook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4A
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    • pp.373-384
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    • 2009
  • For the first step on the quantitative evaluation of shrinkage reduction and differential shrinkage analysis of lightweight aggregate concrete, this study sets the moisture transport model of concrete by pre-absorbed water of porous lightweight aggregates and measured effective moisture diffusion coefficient, moisture capacity, degree of humidity supply and degree of humidity consumption by water binder ratio and aggregate type. The effective moisture diffusion coefficient in steady state caused by humidity difference between inside and outside of concrete had low value as low water-binder ratio. And in case of same water-binder ratio, effective moisture diffusion of mixtures used normal aggregates were lower than those used lightweight aggregates. To determine moisture store capability of concrete - moisture capacity, moisture contents were measured in 9 humidity conditions. As a result moisture contents of mixtures used lightweight aggregates was higher than mixtures used normal aggregates in all humidity conditions. This study measured lightweight aggregates' degree of humidity supply that applicable to normal atmospheric environment (above RH 50%) and made it quantitatively. Also amount of moisture release was set as a exponential function that represents a clear trend proportion to time and inverse proportion to humidity of the surroundings. As the result of measurement about degree of moisture consumption inside concrete following the internal consumption caused by cement hydration self-drying, it was showed that rapid decrease of humidity, around 10%, at early ages (7~10 days) when water-binder ratio is 0.3 and slow decrease around 5% and 1% when water-binder ratio is 0.4 and 0.5.

Development of Automatic Rewetting System for Rough Rice Stored in Round Steel Bin with Stirring Device -Adsorption characteristics of rough rice- (원형철제빈용 벼 자동흡습장치 개발에 관한 연구(I) -벼의 흡습특성-)

  • Kim, J. Y.;Keum, D. H.;Kim, H.;Park, S. H.
    • Journal of Biosystems Engineering
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    • v.26 no.5
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    • pp.469-474
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    • 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.

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An Experimental Study on Engineering Properties of High-Strength Concrete by Revision Error of the Ratio of Surface Moisture in Fine Aggregate (잔골재의 표면수율 보정오차에 따른 고강도콘크리트의 공학적 특성에 관한 실험적 연구)

  • Kang, Suk-Pyo;Jang, Jong-Ho;Park, Yong-Mock;Lee, Seung-Hoon;Yu, Jae-Chul;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.53-56
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    • 2000
  • The performance of high-strength concrete is controlled by the fact, affecting the quality management, especially by revision error in water content of the ratio of surface moisture in fine aggregate. The difference in water content results from the revision error of the ratio of surface moisture and errors in sampled aggregate in the processing ready-mixed concrete plant. This study is to investigate the properties of flowing and hardening by investionally varying the revision error of the ratio of surface moisture in fine aggregate to compare and analyze the variance in quality.

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