• Title/Summary/Keyword: 수분영향

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Effect of Repeated Immersion on Material Properties of Asphalt Mixtures (반복적인 수침이 아스팔트 혼합물의 재료물성에 미치는 영향)

  • Hwang, Sung-Do;Rhee, Suk-Keun
    • International Journal of Highway Engineering
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    • v.10 no.1
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    • pp.75-85
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    • 2008
  • Moisture damage of asphalt mixtures can occur because of a loss of bond between the asphalt binder and the fine and coarse aggregates. Therefore, moisture damage on asphalt pavements is the main cause of potholes, which is one of the main distress type of asphalt pavement. The purpose of this study is to evaluation effect moisture damage on material properties of asphalt mixtures through the laboratory performance test. The existing Modified Lottman test procedure was improved and the number of times that thermal cyclic conditioning can be added until the asphalt mixtures is damaged, was tested in order to exhibit the changes of the material properties because of moisture damage by immersion. Through the above experiments, it was found that the material properties of asphalt mixtures on room-temperature were rapidly decreased with loss of about 50% at initial stage of moisture damage caused by the amount of repeated immersion. Also, it was found that the property damage ratio using material properties of failure energy and $DCSE_f$ by test temperature $25^{\circ}C$ were showed a high relationship to moisture damage of the asphalt mixtures caused by the amount of repeated immersion.

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Comparison of Particle-Size Distribution Models for Estimating Water Retention Characteristic (토양수분특성 추정을 위한 입자크기분포 모형들의 비교)

  • 황상일
    • Journal of Soil and Groundwater Environment
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    • v.7 no.3
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    • pp.103-114
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    • 2002
  • Knowledge of soil water retention characteristic is essential for many problems involving water flow and organic solute transport in unsaturated soils. A physico-empirical approach based on the translation of the particle-size distribution (PSD) into a corresponding water retention curve has been accomplished by others using the concept that the pore-size distribution is directly related to PSD. This approach implies that details of a PSD curve may affect the estimation of water retention characteristic (WRC). To determine whether the WRC estimation using the Arya-Paris model could be affected by the selection of a PSD model, four PSD models with one to four fitting parameters were used. The Jaky model with only one fitting parameter had greater WRC estimation ability than other models with greater number of fitting parameters. The better performance of the Jaky model may be explained by the effect of soil structure in field soils.

The effect of moisture on SCR reaction of NMO (Natural Manganese Ore) (천연망간광석 SCR 반응에서 수분의 영향)

  • Kim, Sungsu;Hong, Sungchang
    • Applied Chemistry for Engineering
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    • v.18 no.4
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    • pp.350-355
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    • 2007
  • The effect of moisture in flue gas on SCR reaction of NMO (Natural Manganese Ore) was studied. The experiments were performed over NMO with NO, $NH_3$ at independent condition or simultaneous condition. $NH_3$ can be oxidized at low temperature by the lattice oxygen in NMO catalyst. The concentration of NO and $NO_2$ by $NH_3$ oxidation with moisture is higher above $300^{\circ}C$ than that without moisture. Moisture would competitively adsorb with NO and $NH_3$ on NMO catalyst. It caused poor NOx conversion to compete against $H_2O$. Besides the NOx conversion efficiency was reduced at below $250^{\circ}C$ because of the dipped $H_2O$ competitively adsorbed $NH_3$. The reactivity of NMO varied with the calcination temperature and the optimum calcination temperature was $400^{\circ}C$ regardless $H_2O$.

The Comparison of Shampoos for Skin Hydration by Measurement of Epidermal Capacitance in Normal Canine Skin (Epidermal Capacitance를 이용한 시판되는 치료용 샴푸의 정상적인 개 피부에 대한 가수효과)

  • Oh, Tae-Ho;Jae-Hoon heong;Jang, Kwang-Ho
    • Journal of Veterinary Clinics
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    • v.18 no.3
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    • pp.206-210
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    • 2001
  • Various commercial shampoos were frequently prescribed for dermatologic therapy in small animal practice. Skim hydration affected by the shampoos, however, was not evaluated routinely. In order to evaluate the skin hydration for the exact prescription of shampoos method to measure skin hydration of shampoos are needed. This study was undertaken to evaluate the skin hydration effect of shampoo on canine skin using Corneometer. Five healthy dogs were applied with 7 commercial shampoos: Humilac, Sebocalm, Sebolytics, Etiderm, Benzoyl peroxide, HyLyt and Zn-7 Derm. Skin hydrations were evaluated by measurement of electrical capacitance by Corneometer. A statistically significant increase in skim hydration was found 17(p<0.05) and 77 minutes(p<0.01) after application of Humilac indicating a humidifying effect of this product. A statistically significant decrease in skin hydration was found for the Benzoyl peroxide after 77 minutes(p<0.05). No statistically significant differences between the other shampoos were found. None of the products tested had any negative effect on the skin barrier function. The Corneometer was found useful for detecting skin hydration to shampoos and considered as a simple and useful tool for prescription of various shampoos routine practice.

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Prediction of Differential Drying Shrinkage in Concrete (콘크리트의 부등건조수축에 관한 연구)

  • 김진근;이칠성
    • Magazine of the Korea Concrete Institute
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    • v.9 no.2
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    • pp.153-161
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    • 1997
  • In the concrete st~uctures exposed to the environmental condition, the water movement is occurred by thc moisture difilsion, and the rnoisturrt distribution in concwt.c is nonunifhrm. Such a non-unif'orm moisture distribution causes tht. diflbrent.ia1 drying shrinkage in concrete structures. From this typc. of' dif'fercntial drying shrinkagr' tensiit-1 stress is occurred in exposure surface of concrete structures. and may result in crack formation. This residual stress is significantly affected by the creep of concrete, and the differential creep is also occurred at the cross section of concrete structures due to moisture difference at each locations. In this study, based on the moisture diffusion theory, a finite element program which is capable of simulating the moisture distribution in concrete was developed. And the analysis method for the differential drying shrinkage was suggested, in which the differential creep was considered. The differential drying shrinkage strain was also measured at various positions of concrete. Finally the validity of analysis method was proved by comparing test results with analytical results.

Interaction Effect of Temperature and Moisture Content on the Oil Expression of Perilla Seed (들깨종자의 압착착유에 미치는 온도와 수분함량의 상호작용 효과)

  • Min, Young-Kyoo;Jeong, Heon-Sang
    • Applied Biological Chemistry
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    • v.37 no.1
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    • pp.14-18
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    • 1994
  • In order to elucidate the interaction effect between temperature and moisture content on the oil expression of perilla seed, recovery of expressed oil (REO) and volumetric strain of pressed cake (VSPC) of both roasted and unroasted perilla seeds were observed at different temperatures of 30, 40, 50 and $60^{\circ}C$, and different moisture contents of 2.5, 4.5, 6.5 and 8.5% (w.b). And duration of press was 11 min and applied pressure was 50 MPa. At the low temperature REO and VSPC of roasted and unroasted perilla seed increased in high moisture content and at the high temperature those increased in low moisture content. But REO and VSPC at 8.5% moisture content were decreased without relation to temperature. From the analysis of variance between expression factors and REO and VSPC, temperature and moisture contents showed high significance. Also the interaction effect between temperature and moisture content was higher than temperature. In our experimental conditions, the highest interaction effect between expression factors was observed in the range of $2.5{\sim}4.5%$ of moisture content in all temperatures. The maximum REO of unroasted perilla seeds was observed as 84.4% at 2.5% of moisture content and $60^{\circ}C$, and that of roasted one was as 84.3% at 6.5% of moisture content and $30^{\circ}C$.

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Effect of Water Stress on Yield and Quality of Ligusticum chuanxiong Hort. (토양수분(土壤水分)이 토천궁(土川芎)의 수량(收量) 및 품질(品質)에 미치는 영향(影響))

  • Kim, Chung-Guk;Kang, Byeung-Hoa;Kim, Sok-Dong;Lee, Sang-Bok
    • Korean Journal of Medicinal Crop Science
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    • v.5 no.1
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    • pp.1-6
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    • 1997
  • The experiment was conducted to investigate the effect of water stress on yield and quality of Ligusticum chuanxiong Hort. The water stress treatment was imposed artificially on seedling, flowering and rhizome enlargement stage of the plant. The root yield rate decreased to 19.1%, 18.2% and by the water stress treatment at rhizome enlargement, seedling and flowering stage, respectively. Portion of the products having commercial quality grade (above 20g of rhizome weight) was 93.4% at control plot, while it was 85%, 81.7% and 78.3% when stressed for water at seedling, flowering and root enlargement stage, respectively. Content of extract was the higher in the order of control, water stressed at rhizome enlargement, flowering and the seedling stage. Postive correlationship was found between yield of rhizome and rootlet yield or economic production ratio, and between dry weight of stem and rootlet yield.

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Effects of Die Temperature and Moisture Content on the Quality Characteristics of Extruded Rice with Mealworm (사출구 온도와 수분함량이 갈색거저리(Mealworm) 첨가 압출성형 백미의 품질 특성에 미치는 영향)

  • Cho, Sung Young;Chatpaisarn, Apapan;Ryu, Gi Hyung
    • Food Engineering Progress
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    • v.21 no.2
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    • pp.116-125
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    • 2017
  • This study aims to make extruded rice snack with high quality in texture and nutrition by adding mealworm. Addition of the mealworm has the merit to fill in high-quality protein and unsaturated fatty acids which are insufficient in rice. Thus, the physicochemical properties were investigated through the process of extrusion cooking. As the extrusion process varied, the die temperatures were set to $120^{\circ}C$ and $130^{\circ}C$. Also, the moisture contents were adjusted to 30% and 35%. The specific length, the expansion ratio, and the water absorption index increased as the added content of mealworm became higher. On the contrary, the density, the breaking strength, the apparent elastic modulus, and the water solubility index decreased. As mealworm and moisture content increased, DPPH radical scavenging activity significantly increased but the rancidity decreased. As a result, the addition of mealworm to the extruded rice snack was effective in improving texture, nutrition, and antioxidation.

The impact of climate change and human activities on the surface water balance with global water resource models (기후변화 및 인간활동 영향으로 인한 글로벌 지면 물수지 변화)

  • Lee, Sang Hyeon;Ho, Hyunjoo;Kim, Yeonjoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.308-308
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    • 2018
  • 전 지구적으로 댐 건설과 가정, 공업 및 농업 용수의 사용 등 인간의 영향으로 유출량, 지하수, 토양수분 등의 다양한 수문요소가 변화를 보이고 있다. 이러한 인간의 영향은 기후변화의 영향과 함께 수문요소에 주요한 동인으로 이의 영향을 이해하고 전망할 필요가 있다. 본 연구는 Inter-Sectoral Impact Model Intercomparison Project를 통해 이용 가능한 여러 글로벌 수자원 모형의 결과를 분석하여 기후변화 및 인간활동의 영향의 상대적 중요성 등을 분석하고자 한다. GFDL, HadGEM, IPSL, MIROC5에서 도출된 기후 시나리오를 기반으로 구동된 글로벌 수자원 모형결과를 살펴보고자 하며, 글로벌 수자원 모형은 CLM, H08, JULES 등을 포함한다. 본 연구에서는 증발산량, 토양수분, 유출 등의 시간 및 공간적 변화, 기후변화 및 인간 활동의 영향이 주요한 역할을 하는 지역 혹은 유역을 확인하는데 초점을 맞추고자 한다.

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집청액이 화전의 관능적 및 물리적 특성에 미치는 영향

  • 장명숙;박정은
    • Proceedings of the Korean Society of Food and Cookery Science Conference
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    • 2003.10a
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    • pp.99-99
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    • 2003
  • 본 연구는 화전의 집청액 종류를 달리하여 사용하였을 때 화전의 관능적 및 물리적 특성에 미치는 효과를 알아보고 맛과 저장성이 가장 좋은 집청액을 찾고자 한다. 집청액으로는 꿀(Sl),조청 (S2),물엿(S3),시럽(S4),설탕(S5)을 사용하였고, 각각의 집청액에 집청하여 플라스틱 통에 담아 뚜껑을 덮어 20$\pm$1$^{\circ}C$에서 24시간 보관하면서 여러 가지 특성을 알아보았다. 수분함량은 저장 시간이 길어질수록 감소하였고, 저장 12시간까지는 S1이 높은 수분함량을 보였고, S3는 저장 6시간 이후부터 가장 높은 수분 함량을 보였다. (중략)

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