• Title/Summary/Keyword: surface moisture

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THE PHYSICALLY-BASED SOIL MOISTURE BALANCE MODEL DEVELOPMENT AND APPLICATIONS ON PADDY FIELDS

  • Park, Jae-Young;Lee, Jae-Hyoung
    • Water Engineering Research
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    • v.1 no.3
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    • pp.243-256
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    • 2000
  • This physically-based hydrologic model is developed to calculate the soil-moisture balance on paddy fields. This model consists of three modules; the first is the unsaturated module, the second is the rice evapotranspiration module with SPAC(soil-plant-atmospheric-continuum), and the third is the groundwater and open channel flows based upon the interrehtionship module. The model simulates the hydrlogical processes of infiltration, soil water storage, deep perocolation or echarge to the shallow water table, transpiration and evaporation from the soil surface and also the interrelationship of the groundwater and river flow exchange. To verify the applicability of the developed model, it was applied to the Kimjae Plains, located in the center of the Dongjin river basin in Korea, during the most serious drought season of 1994. The result shows that the estimated water net requirement was 757mm and the water deficit was about 5.9% in this area in 1994. This model can easily evaluate the irrigated water quantity and visualize the common crop demands and soil moisture conditions.

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Permeabilities of Korean Earthenware Containers and Their Potential for Packaging Fresh Produce

  • Seo, Gyeong-Hee;Chung, Sun-Kyung;An, Duck-Soon;Lee, Dong-Sun
    • Food Science and Biotechnology
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    • v.14 no.1
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    • pp.82-88
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    • 2005
  • Ethnic Korean onggi earthenwares were fabricated using different clay formulations and glazing treatments. Their permeability properties against oxygen, carbon dioxide, and moisture were measured at $20^{\circ}C$ and examined from the aspect of food preservation. Onggi walls consisted of micropores that offered higher gas and moisture permeation rates when compared with other food packaging materials. Earthenware walls were unique in having $CO_2/O_2$ permeability ratios of 0.60-1.00. Gas and moisture permeabilities were lower, with wall structure having lower porosity and surface glazing. Results revealed onggi jar packages of grape fruits could attain wide range of $O_2$ and $CO_2$ concentrations. Onggi containers present good opportunity to obtain optimum packaging conditions for respiring or ripening products, depending on commodity type.

Seasonal Soil Temperature and Moisture Regimes in a Ginseng Garden

  • Bailey, W.G.;Stathers, R.J.;Dobud, A.G.
    • Journal of Ginseng Research
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    • v.12 no.1
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    • pp.53-62
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    • 1988
  • A field experiment was conducted in the arid interior of British Columbia, Canada to assess the seasonal soil temperature and moisture regimes in an American ginseng garden. As a consequence of the man-modified microclimate (elevated shade canopy and surface covering of mulch), the growing environment of the crop was fundamentally altered when compared to adjacent agricultural growing environments. In the ginseng garden, soil temperatures were found to remain low throughout the growing season whereas soil moisture remained high when compared with the outside garden environment. These results indicate that even in the hot, arid environment of the interior of British Columbia, the growing of ginseng is undertaken in sub-optimal conditions for the major part of the growing season. This poses challenges for the producers of the crop to modify the architecture of the gardens to enhance the soil regime without creating a deleterious aerial environment.

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Impacts of Initial Soil Moisture on Hydrologic Outflow in a Distributed FLO-2D Model (분포형 FLO-2D 수문모형에서 초기토양함수가 유출결과에 미치는 영향)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.30 no.8
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    • pp.613-619
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    • 2021
  • Soil water enters the atmosphere via evapotranspiration, where it transforms into atmospheric water vapor and plays important role in the surface-atmosphere energy exchange. Soil conditions have a direct influence on the effective rainfall, and initial soil moisture conditions are important for quantitatively evaluating the effective rainfall in a watershed. To examine the sensitivity of the initial saturation to hydrologic outflow, a two-dimensional distributed FLO-2D hydrologic model was applied to a small watershed. The initial saturation was set to 0.3, 0.5, and 0.7 and the obtained results were compared. The Green-ampt model was chosen to calculate the penetration loss. Depending on the initial soil moisture, the peak flow rate varied by up to 60%, and the total water volume in the watershed by approximately 40%.

An Experiment for Surface Soil Moisture Mapping Using Sentinel-1 and Sentinel-2 Image on Google Earth Engine (Google Earth Engine 제공 Sentinel-1과 Sentinel-2 영상을 이용한 지표 토양수분도 제작 실험)

  • Jihyun Lee ;Kwangseob Kim;Kiwon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.599-608
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    • 2023
  • The increasing interest in soil moisture data using satellite data for applications of hydrology, meteorology, and agriculture has led to the development of methods for generating soil moisture maps of variable resolution. This study demonstrated the capability of generating soil moisture maps using Sentinel-1 and Sentinel-2 data provided by Google Earth Engine (GEE). The soil moisture map was derived using synthetic aperture radar (SAR) image and optical image. SAR data provided by the Sentinel-1 analysis ready data in GEE was applied with normalized difference vegetation index (NDVI) based on Sentinel-2 and Environmental Systems Research Institute (ESRI)-based Land Cover map. This study produced a soil moisture map in the research area of Victoria, Australia and compared it with field measurements obtained from a previous study. As for the validation of the applied method's result accuracy, the comparative experimental results showed a meaningful range of consistency as 4-10%p between the values obtained using the algorithm applied in this study and the field-based ones, and they also showed very high consistency with satellite-based soil moisture data as 0.5-2%p. Therefore, public open data provided by GEE and the algorithm applied in this study can be used for high-resolution soil moisture mapping to represent regional land surface characteristics.

The Effect of Water Immersion on the Surface Strength and the Flexural Strength of the Acrylic Resin for Occlusal Appliances (교합장치용 아크릴레진의 표면경도와 굴곡강도에 대한 침수의 영향)

  • Lee, Hoy-Youn;Im, Yeong-Gwan;Kim, Byung-Gook;Lim, Hoi-Soon;Kim, Jae-Hyung
    • Journal of Oral Medicine and Pain
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    • v.35 no.1
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    • pp.75-81
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    • 2010
  • By repeating nocturnal bruxism occlusal appliance's wearing condition that is used to cure temporomandibular disorders into the vitro experiment, research aims to find out how moisture infiltrated and drying cycle process affects on the surface microhardness of the resin for occlusal appliance and flexural strength. By utilizing resin for occlusal appliance which is the main component of poly methyl methacrylate, bar shaped sample was produced. For the resin sample utilized as the controlled group 1, the sample was infiltrated in the moisture for 7 days in the temperature of 37C. Then, the resin sample of the controlled group 2 was maintained in a dry condition for 7 days in the normal temperature. After that, each sample's surface microhardness and flexural strength were measured. For the resin sample that is utilized as the experimental sample, the sample was infiltrated in the moisture for 7 days in the temperature of 37C. Then, it was inundated for 8 hours a day and dried in the normal temperature for 16 hours with the continuous process of moisture infiltration and dry cycle process for 30 days. During this cycle process, sample's surface and flexural strength were measured in the 1st day, 7th day, and 30th day. Then, it was statistically analyzed to find out the difference of controlled and experiment group's surface microhardness and flexural strength. Results are 1. For the experimental and controlled group's surface microhardness of the resin for the occlusal appliance, it did not show any significant differences after moisture infiltration and dry cycle process repetition. 2. In case of the flexural strength for resin for the occlusal appliance, experimental group with moisture infiltration and dry cycle for 30 day process had greater effect than the experimental group at the 1st day and controlled group These results can be considered to be utilized from the patients of the temporomandibular disorders towards occlusal appliance used and maintained method.

Comparison of Soil Evaporation Using Equilibrium Evaporation, Eddy-Covariance and Surface Soil Moisture on the Forest Hillslope (산림 사면에서 토양수분 실측 자료, 평형증발 및 에디-공분산방법을 이용한 토양증발비교)

  • Gwak, Yong-Seok;Kim, Sang-Hyun;Kim, Su-Jin
    • Journal of Environmental Science International
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    • v.22 no.1
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    • pp.119-129
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    • 2013
  • We compared equilibrium evaporation($E_{equili}$) eddy-covariance($E_{eddy}$) with soil moisture data($E_{SMseries}$) which were measured with a 2 hours sampling interval at three points for a humid forest hillslope from May 5th to May 31th in 2009. Accumulations of $E_{eddy}$, $E_{equili}$ for the study period were estimated as 2.52, 3.28 mm and those of $E_{SMseries}$ were ranged from 1.91 to 2.88 mm. It suggested that the eddy-covariance method considering the spatial heterogeneity of soil evaporation is useful to evaluate the soil evaporation. Method A, B and C were proposed using mean meterological data and daily moisture variation and the computations were compared to eddy-covariance method and equilibrium evaporation. The methods using soil moisture data can describe the variations of soil evaporation from eddy-covariance through simple moving average analysis. Method B showed a good matched with eddy-covariance method. This indicated that Dry Surface Layer (DSL) at 14:00 which was used for method B is important variable for the evaluation of soil evaporation. The total equilibrium evaporation was not significantly different to those of the others. However, equilibrium evaporation showed a problem in estimating soil evaporation because the temporal tendency of $E_{equili}$ was not related with the those of the other methods. The improved understanding of the soil evaporation presented in this study will contribute to the understandings of water cycles in a forest hillslope.

Multi-physics Modelling of Moisture Related Shrinkage in Concrete (콘크리트 수분관련 수축에 관한 다중물리모델)

  • Lee, Chang-Soo;Park, Jong-Hyok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.2
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    • pp.1-9
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    • 2009
  • Water binder ratio combine high-performance concrete shrinkage of less than 0.4 to determine the transformation to a total shrinkage of water to move outside and internal consumption of moisture due to drying shrinkage and autogenous shrinkage, and then, the relative humidity changes and strain to be approached by surface physics describe the relationship between self-desiccation and autogenous shrinkage was set. To verify the self-desiccation in the humidity shrinkage and humidity measurements performed, and the research model, Tazawa, CEB-FIP model than to let the measure and the most similar results in this study based on self-desiccation model, autogenous shrinkage didn't represent the linear shrinkage by the drying shrinkage of the external moving but exponential relationships, unlike with the nature and rapid in the early age properly describes the attributes in shrinkage could see. After this research to move moisture and to reflect the shrinkage model, temperature, moisture transfer, strain analysis by multi-physics model is very similar to the results of mock-up specimen measurements performed for this research, the value measured by the internal consumption of moisture, therefore self-desiccation and a multi-physics model considering autogenous shrinkage might be relevant.

Assessment of Agricultural Drought Using Satellite-based TRMM/GPM Precipitation Images: At the Province of Chungcheongbuk-do (인공위성 기반 TRMM/GPM 강우 이미지를 이용한 농업 가뭄 평가: 충청북도 지역을 중심으로)

  • Lee, Taehwa;Kim, Sangwoo;Jung, Younghun;Shin, Yongchul
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.4
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    • pp.73-82
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    • 2018
  • In this study, we assessed meteorological and agricultural drought based on the SPI(Standardized Precipitation Index), SMP(Soil Moisture Percentile), and SMDI(Soil Moisture Deficit Index) indices using satellite-based TRMM(Tropical Rainfall Measuring Mission)/GPM(Global Precipitation Measurement) images at the province of Chungcheongbuk-do. The long-term(2000-2015) TRMM/GPM precipitation data were used to estimate the SPI values. Then, we estimated the spatially-/temporally-distributed soil moisture values based on the near-surface soil moisture data assimilation scheme using the TRMM/GPM and MODIS(MODerate resolution Imaging Spectroradiometer) images. Overall, the SPI value was significantly affected by the precipitation at the study region, while both the precipitation and land surface condition have influences on the SMP and SMDI values. But the SMP index showed the relatively extreme wet/dry conditions compared to SPI and SMDI, because SMP only calculates the percentage of current wetness condition without considering the impacts of past wetness condition. Considering that different drought indices have their own advantages and disadvantages, the SMDI index could be useful for evaluating agricultural drought and establishing efficient water management plans.

Moisture Gettering by Porous Alumina Films on Textured Silicon Wafer (실리콘 표면에 증착된 다공성 알루미나의 수분 흡착 거동)

  • Lim, Hyo Ryoung;Eom, Nu Si A;Cho, Jeong-Ho;Choa, Yong-Ho
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.401-406
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    • 2015
  • Getter is a class of materials used in absorbing gases such as hydrogen and moisture in microelectronics or semiconductor devices to operate properly. In this study, we developed a new device structure consisting of porous anodized alumina films on textured silicon wafer, which have cost efficiency in materials and processing aspects. Anodic aluminum oxide (AAO) with controlled pore sizes can be applied to a high-efficiency moisture absorber due to the high surface area and OH- saturated surface property. The moisture sorption capacity was 2.02% (RH=35%), obtained by analyzing isothermal adsorption/desorption curve.