• Title/Summary/Keyword: Moisture

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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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Finite Element Analysis of Heat and Moisture Transfer in Porous Materials (다공성 물질의 열 및 습도 전달에 관한 유한요소 해석)

  • Lee, Ho-Rim;Geum, Yeong-Tak;Song, Chang-Seop;O, Geun-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.7
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    • pp.158-167
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    • 1999
  • Heat and moisture transfer associated with porous materials are investigated. The heat and moisture transfer in porous materials caused by the interaction of moisture gradient, temperature gradient, conduction, and evaporation are considered. The variations of temperature and moisture not only change the volume but also induce the hygro-thermal stress. The finite element formulation for solving the temperature and moisture transfer as well as the associated hygro-thermal stresses is developed. In order to verify the finite element formulation, the heat and moisture moving boundary problem in a half space and the hygro-thermo-mechanical problem in an infinite plate with a circular hole are analyzed. Temperature profile, moisture profile, and hygro-thermal stresses are compared with those of analytic solution and other investigator. Good agreements are examined

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Observation of Moisture Content in Wood at Non-Steady State

  • Hwang, Sung-Wook;Lee, Won-Hee
    • Journal of the Korea Furniture Society
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    • v.20 no.6
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    • pp.599-604
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    • 2009
  • For the search of unified law of moisture movement in wood, moisture distribution of Korean red pine at non-steady state was investigated. We assume that the equilibrium moisture content (EMC) in wood depends on only temperature and relative humidity, it can be control in temperature and humidity chamber. If temperature is constant and humidity or vapor pressure is changed with sin curve shape at adequate cycles, EMC in chamber can be changed as well with sin-curve shape. The setup condition of a non-steady state in humidity control chambers is a constant temperature at $20^{\circ}C$ and 15+10 sin ${\omega}t$ percent EMC. It can be found that the distribution of moisture in the specimen with varying relative humidity are illustrated various types. Moisture in wood is complicated and vibrates with the moisture sorption process. Considering a unified law of moisture movement in wood, it is considered that the most important fact is to search the method of precise diffusion & transfer coefficients.

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Nonlinear calculation of moisture transport in underground concrete

  • Ba, M.F.;Qian, C.X.;Gao, G.B.
    • Computers and Concrete
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    • v.13 no.3
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    • pp.361-375
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    • 2014
  • The moisture transport in underground concrete was experimentally investigated and the nonlinear model of moisture transport considering the effects of water diffusion, hydration of cementicious materials and water permeability was proposed. The consumed moisture content by self-desiccation could be firstly calculated according to evolved hydration degree of cement and mineral admixtures. Furthermore, the finite differential method was adopted to solve the moisture transport model by linearizing the nonlinear moisture diffusion coefficient. The comparison between experimental and calculated results showed a good agreement, which indicated that the proposed moisture model could be used to predict moisture content evolution in underground concrete members with drying-wetting boundaries.

Numerical Analysis of Moisture Ventilation in the Dry Room (Dry room내 수분환기에 대한 수치적 연구)

  • 이관수;임광옥;정영식
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.10
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    • pp.908-916
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    • 2000
  • In this paper, the characteristics of moisture ventilation in the lithium ion battery manufacturing dry room are studied numerically using standard $k-\varepsilon$ turbulence model. Both the steady-state and the unsteady behaviors of moisture ventilation are analyzed by considering local and uniform moisture generation. In order to evaluate the characteristics of moisture ventilation, three scales of ventilation efficiency and characteristic ventilation time are presented from the numerical results. It was shown that moisture distribution was dependent strongly on the flow field. The characteristics of moisture ventilation were improved by 20% and 40% in terms of the 1st scale of ventilation efficiency (SVE1) and the 2nd scale of ventilation efficiency (SVE2), respectively, through the modifications of design variables such as the addition of inlets, outlets and partition. A significant improvement in the characteristic ventilation time and the moisture exhaust efficiency was also made by these modifications.

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Shelf Life Prediction for Packaged Produce Sensitive to Moisture Damage (수분손상에 민감한 포장된 제품의 저장수명 예측)

  • Lee, Chong-Hyun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.1
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    • pp.23-32
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    • 1997
  • The change in moisture content of moisture sensitive products in moisture-semipermeable packages was investigated for the purpose of predicting the shelf life of a product-package combination. A mathematical model, and a computer program based on the physiochemical properties of the product and the moisture permeability of the package was developed. The moisture content for products in moisture-semipermeable packages was determined under various environmental conditions and the results were compared with the predicted values by means of the simulation model. These experimental studies demonstrated that the prediction of the change in moisture content of packaged products over time by the simulation model is accurate, within a practical range of temperature and relative humidity values. The developed semi-empirical model is considered to have applications in industry, since it provides product shelf life information for a range of temperature and relative humidity conditions, with a limited number of experimentally obtained data points.

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SIMULATION OF SOIL MOISTURE VARIABILITY DUE TO CLIMATE ORANGE IN NORTHEAST POND RIVER WATERSHED, NEWFOUNDLAND, CANADA

  • A. Ghosh Bobba;Vijay P. Singh
    • Water Engineering Research
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    • v.4 no.1
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    • pp.31-43
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    • 2003
  • The impacts of climate change on soil moisture in sub - Arctic watershed simulated by using the hydrologic model. A range of arbitrary changes in temperature and precipitation are applied to the runoff model to study the sensitivity of soil moisture due to potential changes in precipitation and temperature. The sensitivity analysis indicates that changes in precipitation are always amplified in soil moisture with the amplification factor for flow. The change in precipitation has effect on the soil moisture in the catchment. The percentage change in soil moisture levels can be greater than the percentage change in precipitation. Compared to precipitation, temperature increases or decreases alone have impacts on the soil moisture. These results show the potential for climate change to bring about soil moisture that may require a significant planning response. They are also indicative of the fact that hydrological impacts affecting water supply may be important in consider-ing the cost and benefits of potential climate change.

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Monitoring and Analysis of Moisture Contents for Traditional and New-styled Hanoks (전통한옥과 신한옥의 함수율 모니터링 및 분석)

  • Kim, Yeong-Min
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.3
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    • pp.29-36
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    • 2018
  • In this study, the moisture contents of four Hanoks have been monitored and the results were analyzed. Murujeong and Ongojae were built by traditional construction method and material, and Jeeshinjae and Hwakyeongdang were built by modernized construction method and material. Hwakyeongdang was monitored about 2 years and 9 months and the other three Hanoks were monitored about 4 years and 2 months. The surface moisture contents were measured by the non-destructive electronic resistant type moisture content meter. The measured moisture contents were affected by the orientation to the sun, wood type, temperature and relative humidity. The columns on the northern side and lumber showed more moisture contents than those of the southern side and glue-laminated wood. The moisture contents and relative humidity showed proportional relationship. The moisture contents of all four monitored Hanoks existed proper range by and large.

Effects of Maturing Period and Moisture Content of Swine Manure on Composting Potentials (돈분의 수분조절 및 부숙기간이 퇴비화에 미치는 영향)

  • 김원호;정광화;서성;백광수;신동은;유성오;김원영
    • Journal of Animal Environmental Science
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    • v.4 no.1
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    • pp.47-53
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    • 1998
  • The purpose of this study was to investigate the change of temperature, moisture content, weight and chemical properties in swine manure during the maturing process and moisture content of swine manure. The manure production on the early time(1 days), middle(25 days: and late(50 days) were made by moisture 45%, 55%, 65%, 75% in swine manure, according to manure treatment of the early time, the highest temperature of swine manure treatment was 59$^{\circ}C$ as moisture 75% after mixed 24 hours, the lowest 45% in mixed 25 days(middle time), 32$^{\circ}C$ as moisture 45% in mixed 50 days(late time). 2. Weight change during maturing manure, the most treatment of weight decrease was 17.4% as moisture 45%, the least of those was 12.2% as moisture 75% during maturing process of swine manure. 3. Volume change during maturing manure, the most treatment of volume decrease was 37.1% as moisture 65%, the least of those was 32.1% as moisture 55% during maturing swine manure, but not big difference between treatment. 4. T-N, P2O5, K2O content of compost were increased during maturing process, On the contrary, T-C content and C/N ratio were reduced.

Environmentally Friendly Paper with Superior Moisture -Proof Properties(II) -Recyclable properties of moisture-proof paper- (방습 효과가 우수한 환경친화적인 방습지(2보) -방습 도공지의 재생 특성-)

  • 이명구;유재국
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.1
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    • pp.13-18
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    • 2003
  • This study was done in an effort to evaluate the possibility of recyclability of moisture-proof paper. Because it is difficult to recycle laminated moisture-proof paper, a mixture of styrene-butadiene latex(SB latex) and wax emulsion was used as moisture-proof paper chemicals. A bar coater was applied to make moisture-proof paper and the coated weight was 17 g/$m^2$. The mixing ratios of SB latex to wax emulsion were 85 : 15, 87 : 13, and 90 : 10, respectively. It was observed that the moisture-proof paper treated with SB latex and wax emulsion at the appropriate ratio could be recycled effectively. The moisture-proof paper was similar to base paper in degree of pulping, and there was no significant difference in dispersion between moisture-proof paper and base paper. Most of wax particle which caused the spots during drying process could be removed by flotation process. Tensile strength and tear strength of handsheets made of both moisture-proof paper and base paper after pulping was measured to examine the fiber bonding and no significant difference in mechanical properties was observed.