• Title/Summary/Keyword: moisture balance

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Assessing Climate Change Impact on Hydrological Components of Yongdam Dam Watershed Using RCP Emission Scenarios and SWAT Model (RCP 배출 시나리오와 SWAT 모형을 이용한 기후변화가 용담댐 유역의 수문요소에 미치는 영향 평가)

  • Park, Jong-Yoom;Jung, Hyuk;Jang, Cheol-Hee;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.3
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    • pp.19-29
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    • 2014
  • This study was to evaluate the potential climate change impact on watershed hydrological components of evapotranspiration, surface runoff, lateral flow, return flow, and streamflow using Soil and Water Assessment Tool (SWAT). For Yongdam dam watershed (930 $km^2$), the SWAT model was calibrated for five years (2002-2006) and validated for three years (2004-2006) using daily streamflow data at three locations and daily soil moisture data at five locations. The Nash-Sutcliffe model efficiency (NSE) and coefficient of determination ($R^2$) were 0.43-0.67 and 0.48-0.70 for streamflow, and 0.16-0.65 and 0.27-0.76 for soil moisture, respectively. For future evaluation, the HadGEM3-RA climate data by Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios were adopted. The biased future data were corrected using 30 years (1982-2011, baseline period) of ground weather data. The HadGEM3-RA 2080s (2060-2099) temperature and precipitation showed increase of $+4.7^{\circ}C$ and +22.5 %, respectively based on the baseline data. The impacts of future climate change on the evapotranspiration, surface runoff, baseflow, and streamflow showed changes of +11.8 %, +36.8 %, +20.5 %, and +29.2 %, respectively. Overall, the future hydrologic results by RCP emission scenarios showed increase patterns due to the overall increase of future temperature and precipitation.

Basic Study on the Heat Transfer During Rapid Freezing of Syobean Seed by Liquid Nitrogen

  • Kawano, Toshio;Nakano, Kohei;Murata, Satoshi
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.443-452
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    • 1993
  • Direct freezing tests of soybean seed by liquid nitrogen were carried out at various moisture contents and the following important conclusions were drawn from the results of temperature measurements of soybean seed and photographs of bubbles generated on its surface : 1) Assuming that the temperature gradient in a soybean seed is negligible because of its small seed size and the freezing ratio is followed the Heiss's formula, and a differential equation based on the heat energy balance was introduced . The equation was easily solved by the Runge-Kutta-Gill method and the predicted values of the temperature were in good agreement with the observed data. 2) The photographs of bubble generation during freezing showed the boiling mode was nucleate, and then the most suitable formula on the nucleate boiling heat transfer was introduced from many formulate proposed up to now by fitting the calculated values based on the formula to the observed data. The formula used for the predict on of the seed temperature was as follows: $\frac{{\partial}T_s}{\partial\theta}\;=\;-\frac{{\alpha}(T_s\;-\;T_L)^{3.3}}{W(C_s\;-\;\frac{{\delta}m(CT_s\;+\;{\sigma})}{T_s^2})}$ where C = difference of the specific heat between pure ice and water m=moisture content of soybean seed $T_s$ = seed temperature $T_L$ = Temperature of liquid nitrogen W = mass of soybean seed $\alpha$ = proportional constant $\delta$ = constant depends on variety or the type of seed $\theta$ = time $\sigma$ = latent heat of melting of pure ice This study will give important information in the hydro-freezing technique by liquid nitrogen, available as a new technique of processing agricultural products in the near future.

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Rooibos Extract Effect on the Seborrheic Scalp Improvement of Middle-Aged Men (루이보스 추출물이 중년 남성의 지루성 두피 개선에 미치는 효과)

  • Lee, Jong-Youl;Lee, Song-Jeong;You, Seon-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.311-318
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    • 2016
  • This study conducted a 4-week clinical trial on 30 males suffering from seborrheic dermatitis and hair loss symptoms to examine the effects of rooibos extract on the seborrheic dermatitis improvement of 30-50 year old middle aged males. The comparison group used shampoo with no rooibos extract while experiment group 1 used shampoo including rooibos extracts, and experiment group 2 used shampoo and scalp enhancer including the rooibos extracts. The results showed that there were no meaningful changes on the scalps of the comparison group while experiment group 2, which used both shampoo and scalp enhancer including rooibos, showed better improvement on seborrheic dermatitis than experiment group 1 which only used shampoo including rooibos. These results imply that shampoo and scalp enhancer including rooibos extracts effectively improve the oil-moisture balance on seborrheic dermatitis and effectively deals with scalp itchiness redness and the color tone of the scalp, suggesting its use in scalp cosmetics that include antioxidation activation elements, which are effective in improving seborrheic dermatitis.

The Drying Characteristics of Apples at Various Drying Conditions (사과의 건조조건(乾燥條件)에 따른 건조특성(乾燥特性))

  • Jung, Shin-Kyo;Choi, Yong-Hee;Shon, Tae-Hwa;Choi, Jong-Uck
    • Korean Journal of Food Science and Technology
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    • v.18 no.1
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    • pp.61-65
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    • 1986
  • This study was performed to examine the drying characteristics of apples at various drying conditions. Air velocity has no effect on the drying rate except the constant rate period. In this experiment the diffusion coefficients of moisture in the apple tissue were in the range of $1.1470-2.2148{\times}10cm^2/sec$. As a result of balance of heat and mass transfer during the falling rate period. an empirical equation based on Fick's law was obtained as follows; $log{\Delta}t\;=\;log\;t_o\;-\;D{\frac{{\pi}^2{\theta}}{4d.}}$ This equation can be used to calculate the temperature of apples during the falling rate period, provided the diffusion coefficients of apple are known. The experimental values of the internal moisture distribution during apple dehydration were nearly in accord with the theoretical values.

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A Study on the Diverse Roles of Sugar in Confectionery and Bread-making. (제빵 제과에 다양한 설탕 이용에 관한 연구)

  • 이명호
    • Culinary science and hospitality research
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    • v.4
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    • pp.249-269
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    • 1998
  • What satisfies the desire of human beings about taste most easily is sweet taste, and it has seemed that the pronoun of sweet taste is sugar. Sugar is used in confectionery and bread-making essentially, and it has influence on the structure and touch of baked confectionery. In addition, if we soften the and apply heat, coloring is made. Thus, it colors good. It doesn't have a sweet taste, but it has the effect to emit fragrance variously, balance and soften the product. The kinds of sugar are very diverse, and it is sugar to be referred to as white sugar is used most frequently. In this study, this researcher examined the classification of physicochemical property and melting point etc. of sugar in confectionery and bread-making through theoretical study, about the simple classification of sugar. In addition, this researcher approached about the role of sugar in confectionery and bread-making and about the influence to have when it is more or less than proper quantity, centering around function. As the result, this researcher extracted the importance of sugar in confectionery and bread-making. It means that the increase of 5% of sugar quantity decreases the absorption quantity of moisture by 1% in bread-making and that the excess of 8% of sugar slow the action of yeast in straight method. Besides, there are the properties such as absorptive property, permeability, storage nature, aging prevention of starch, oxidation restraint of oils and fats, the gelation action of pectin, the fermentation acceleration of yeast, and the emulsification-maintaining-nautre and antiseptics effect of fat-soluble material. And in confectionery, sugar makes fragrance and peel color, increases the storage nature with moisture maintenance and has the softening effect. So, it is considered that the attitude to study and make efforts continuously on the basis of the role of sugar will have to be unfolded in confectionery and bread-making.

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Evaluation of Water Retentive Pavement as Mitigation Strategy for Urban Heat Island Using Computational Fluid Dynamics

  • Cortes, Aiza;Shimadera, Hikari;Matsuo, Tomohito;Kondo, Akira
    • Asian Journal of Atmospheric Environment
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    • v.10 no.4
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    • pp.179-189
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    • 2016
  • Here we evaluated the effect of using water retentive pavement or WRP made from fly ash as material for main street in a real city block. We coupled computational fluid dynamics and pavement transport (CFD-PT) model to examine energy balance in the building canopies and ground surface. Two cases of 24 h unsteady analysis were simulated: case 1 where asphalt was used as the pavement material of all ground surfaces and case 2 where WRP was used as main street material. We aim to (1) predict diurnal variation in air temperature, wind speed, ground surface temperature and water content; and (2) compare ground surface energy fluxes. Using the coupled CFD-PT model it was proven that WRP as pavement material for main street can cause a decrease in ground surface temperature. The most significant decrease occurred at 1200 JST when solar radiation was most intense, surface temperature decreased by $13.8^{\circ}C$. This surface temperature decrease also led to cooling of air temperature at 1.5 m above street surface. During this time, air temperature in case 2 decreased by $0.28^{\circ}C$. As the radiation weakens from 1600 JST to 2000 JST, evaporative cooling had also been minimal. Shadow effect, higher albedo and lower thermal conductivity of WRP also contributed to surface temperature decrease. The cooling of ground surface eventually led to air temperature decrease. The degree of air temperature decrease was proportional to the surface temperature decrease. In terms of energy balance, WRP caused a maximum increase in latent heat flux by up to $255W/m^2$ and a decrease in sensible heat flux by up to $465W/m^2$.

Study on the Continuous Composting Process to Reduce the Use of Bulking Agent in Pig Slurry (톱밥 절감형 돈분 슬러리 연속 퇴비화 공정 연구)

  • Ryoo, J,.W.
    • Journal of Animal Environmental Science
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    • v.13 no.2
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    • pp.121-128
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    • 2007
  • To develop the composting system to reduce the use of bulking agent, continuous composting was performed with farmer scale facility, The plant comprises a horizontal pit reactor closed inside a greenhouse and equipped with a turning machine moving on rails. The pit was 9m wide and 50m long and the maximum height of loaded materials was $1.8m^2$. The materials remained in the reactor for 5 months. During the composting process, temperature and water content measured and water balance was evaluated. The reaction temperature of composting was changed $30{\sim}50^{\circ}C$ and high in the middle and low in under composting piles. The moisture contents of the compost were approximately 70% during the experiment. The amount of effluent was 10.6% and $3.16m^3$ of pig slurry per $1m^3$ of bulking agent was treated during continuous composting process. BOD and SS reduction of the effluent in continuous composting was 86.5% and 92.2%, respectively. Indoor relative humidity in night time was changed between 80 and 100%.

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Sensitivity Analysis of Design Parameters of Air Tightness in Underground Lined Rock Cavern (LRC) for Compressed Air Energy Storage (CAES) (복공식 지하 압축공기에너지 저장공동 기밀시스템 설계변수의 민감도 해석)

  • Kim, Hyung-Mok;Rutqvist, Jonny;Ryu, Dong-Woo;Sun-Woo, Choon;Song, Won-Kyong
    • Tunnel and Underground Space
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    • v.21 no.4
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    • pp.287-296
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    • 2011
  • We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than $1.0{\times}10^{-18}\;m^2$ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 MPa. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

Prediction of Sorption Characteristics by Mass Balance Concept (함량비례 개념에 의한 수분흡습 특성의 예측)

  • Yoon, Heeny H.N.;Kim, H.;Shin, Y.D.;Yoo, M.Y.
    • Korean Journal of Food Science and Technology
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    • v.18 no.2
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    • pp.77-81
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    • 1986
  • The water sorption isotherms of individual insoluble components of corn starch, isolated soybean protein (ISP) and casein and their binary mixtures of corn starch-lSP and corn starch-casein were measured and analyzed. BET monolayer values and Smith plot parameters from the results of sorption isotherms were calculated by mass balance concept . The comparisons between experimental and predicted values resulted in an error of 2.29% for equilibrium moisture content and an error of 2.95% in monolayer value for the mixture 50% corn starch-50% ISP. On the other hand , for the mixture 50% corn starch-50% casein the errors were 2.66% and-5.34%, respectively.

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Analysis of Drought Detection and Propagation Using Satellite Data (인공위성 영상 정보를 이용한 가뭄상황 및 징후분석)

  • Shin, Sha-Chul;Eoh, Min-Sun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.2 s.13
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    • pp.61-69
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    • 2004
  • Drought is one of the mai or environmental disasters. Weather data, particularity rainfall, are currently the primary source of information widely used for drought monitoring. However, weather data are often from a very sparse meteorological network. Therefore, data obtained from the Advanced Very High Resolution Radiometer(AVHRR) sensor boarded on the NOAA polar-orbiting satellites have been studied as a tool for drought monitoring. The normalized difference vegetation index(NDVI) and vegetation condition index(VCI) were used in this study. Also, a simple method to detect drought Is Proposed based on climatic water balance using NOAA/AVHRR data. The results clearly show that temporal and spatial characteristics of drought in Korea can be detected and mapped by the moisture index.