• Title/Summary/Keyword: surface moisture

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Moisture Migration of Concrete Members under High Temperature (고온조건에서 콘크리트 부재의 수분이동)

  • Lee, Tae-Gyu;Kim, Hye-Uk
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1530-1535
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    • 2009
  • Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the high strength concrete members under the high temperature is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

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Development of the non contact tongue moisture measuring device (비접촉식 설면 습윤도 측정 기구의 개발)

  • Kim, Dae-Bok;Park, Yu-Gyung;Kim, Ki-Wang
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.14 no.2
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    • pp.67-74
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    • 2010
  • Objectives: Tongue moisture is one of major features in tongue diagnosis of Oriental Medicine. But with regard to the methods to qualify the tongue moisture level, there have been no adequate modalities to satisfy clinicians' needs. So we developed an novel device and method to quantify the tongue moisture level without contact. Methods and Materials: Ratio of saturated area to total tongue area in the image captured with a spot light at various angles was calculated. We regarded that ratio represented the moisture of tongue surface. To evaluate the performance of suggested method, we observed the correlation between conventional contact method and our method with 19 healthy subjects. Results: With comparison to conventional contact method (Schirmer test), the suggested method showed good correlation (R = 0.8602, R2 = 0.7399). Conclusion: This Method could be a convenient and robust method to evaluate tongue moisture.

Enzymatic Treatment of Polyamide Fiber by Alcalase (알칼라제를 이용한 폴리아미드 섬유의 효소가공)

  • Song, Yu-Sun;Song, Wha-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.8
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    • pp.1006-1013
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    • 2011
  • An enzymatic treatment method using alcalase was introduced to improve the moisture characteristic of the polyamide fiber. The alcalase treatment conditions such as the pH, treatment temperature, enzyme concentration, and treatment time were optimized by measuring the amino groups. The changes in the weight loss, tensile strength, moisture regain, water contact angle (WCA), and water absorption rate of the polyamide fiber with the changes in the alcalase treatment conditions were evaluated. The optimum alcalase treatment conditions for polyamide fiber were found to be a treatment temperature of 50oC, a treatment time of 50 minutes, an alcalase concentration of 10% (owf), and a pH of 7.0. The ethylenediaminetetraacetic acid (EDTA) and L-cysteine accelerated the activity of the enzyme; however, they did not have an effect on the amino group production of the fiber surface. The alcalase treatment of the polyamide fiber improved the fiber's moisture regain, WCA, and absorption rate due to the amino group on the fiber surface. The results showed that the alcalase treatment of polyamide fiber is an effective method to improve the moisture characteristic of the polyamide fiber.

Changes in the Moisture Stability of $CaS:Eu^{2+}$ Phosphors with Surface Coating Methods

  • Yoo, Sun-Hwa;Kim, Chang-Keun
    • Macromolecular Research
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    • v.17 no.11
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    • pp.907-911
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    • 2009
  • To improve the moisture stability of the $CaS:Eu^{2+}$ red phosphor, surface coatings with silica nanoparticles were performed using five different methods, i.e., $P_1$, $P_2$, $P_3$, $P_4$, and $P_5$. The phosphors were coated with silica nanoparticles using a dip coating method ($P_1$) and sol-gel method ($P_2$). The phosphors were coated using a solution containing silica nanoparticles and poly(1-vinyl-2-pyrrolidone), PVP, $(P_3$). The phosphors were also coated with silica nanoparticles by reacting with the 1-vinyl-2-pyrrolidone (VP) monomer ($P_4$) or by reacting with mixtures containing VP and tetraethylorthosilicate ($P_5$). A decrease in the photoluminescence (PL) intensity was observed regardless of the coating methods. However, the moisture stability of the phosphors was enhanced by the coating when aged in a temperature-controlled humidity chamber. Among these methods, the $P_4$ (or $P_5$) method exhibited the greatest increase in moisture stability of the phosphors. The coated phosphors showed a relatively constant intensity with aging time, whereas the uncoated phosphor showed a decrease.

Changes of Specific Surface Area of the Steam Exploded Wood (폭쇄처리 목재의 비표면적변화)

  • Yang, Jae-Kyung;Kim, Hyun-Jung;Lee, Weon-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.1
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    • pp.54-60
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    • 1995
  • This paper reports on the changes of equilibrium moisture contents and specific surface areas of Poplar wood(Populus euramericana) for various steam explosion treatments. Equilibrium moisture contents(EMC) and specific surfaces of steam exploded woods were measured under the moisture adsorption course at 25$^{\circ}C$, and compared with those of other materials and wood meals. The EMCs of steam exploded wood meal were 1~5% less in comparison with that of wood meal. In the case of delignified steam exploded wood meal and delignified wood meal, the same tendency was appeared too. But absolute values of EMCs for delignified wood meals were larger than those of the wood meal. For the changes of EMC by the steam exploded conditions, the EMC decreased with the increase of the steam explosion pressure. On the other hand, specific surface areas were calculated from BET plots based on amounts of monomolecular vapor adsorption of various wood meals. Specific surface areas of the wood meal and delignified wood meal were 90~145, 34~90($m^2/g$) respectively, and which were greater in comparison with those of steam exploded wood meals and delignified steam exploded wood meals. From these results, it is considered that the amount of water vapor adsorption was decreased by the increase of the crystallinity, effect of heat treatment, and coating by melted lignin in during the steam explosion.

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Assessment of Noah land surface model-based soil moisture using GRACE-observed TWSA and TWSC (GRACE 관측 TWSA와 TWSC를 활용한 Noah 지면모형기반 토양수분 평가)

  • Chun, Jong Ahn;Kim, Seon Tae;Lee, Woo-Seop;Kim, Daeha
    • Journal of Korea Water Resources Association
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    • v.53 no.4
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    • pp.285-291
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    • 2020
  • The Noah 3.3 Land Surface Model (LSM) was used to estimate the global soil moisture in this study and these soil moisture datasets were assessed against satellite-based and reanalysis soil moisture products. The Noah 3.3 LSM simulated soil moistures in four soil layers and root-zone soil moistures defined as a depth-weighted average in the first three soil layers (i.e., up to 1.0 m deep). The Noah LSM soil moisture products were then compared with a satellite-based soil moisture dataset (European Space Agency Climate Change Initiatives (ESA CCI) SM v04.4) and reanalysis soil moisture datasets (ERA-interim). In addition, the five major basins (Yangtze, Mekong, Mississippi, Murray-Darling, Amazon) were selected for the assesment with the Gravity Recovery and Climate Experiment (GRACE)-based Total Water Storage Anomaly (TWSA) and TWS Change (TWSC). The results revealed that high anomaly correlations were found in most of the Asia-Pacific regions including East Asia, South Asia, Australia, and Noth and South America. While the anomaly correlations in the Murray-Darling basin were somewhat low, relatively higher anomaly correlations in the other basins were found. It is concluded that this study can be useful for the development of soil moisture based drought indices and subsequently can be helpful to reduce damages from drought by timely providing an efficacious strategy.

Evaluation of High-Resolution Hydrologic Components Based on TOPLATS Land Surface Model (TOPLATS 지표해석모형 기반의 고해상도 수문성분 평가)

  • Lee, Byong-Ju;Choi, Young-Jean
    • Atmosphere
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    • v.22 no.3
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    • pp.357-365
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    • 2012
  • High spatio-temporal resolution hydrologic components can give important information to monitor natural disaster. The objective of this study is to create high spatial-temporal resolution gridded hydrologic components using TOPLATS distributed land surface model and evaluate their accuracy. For this, Andong dam basin is selected as study area and TOPLATS model is constructed to create hourly simulated values in every $1{\times}1km^2$ cell size. The observed inflow at Andong dam and soil moisture at Andong AWS site are collected to directly evaluate the simulated one. RMSEs of monthly simulated flow for calibration (2003~2006) and verification (2007~2009) periods show 36.87 mm and 32.41 mm, respectively. The hourly simulated soil moisture in the cell located Andong observation site for 2009 is well fitted with observed one at -50 cm. From this results, the cell based hydrologic components using TOPLATS distributed land surface model show to reasonably represent the real hydrologic condition in the field. Therefore the model driven hydrologic information can be used to analyze local water balance and monitor natural disaster caused by the severe weather.

The Physical Properties and Dyeability of KOH Treated Cotton Fabrics (KOH 처리 면직물의 물성 및 염색성)

  • Song, Hyun-Joo;Kim, Su-Mi;Song, Wha-Soon
    • Fashion & Textile Research Journal
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    • v.7 no.1
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    • pp.91-95
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    • 2005
  • The purpose of this study is to investigate the improvement of fiber surface, physical properties and research the physical properties and dyeability of cotton fabrics treated with KOH solution at low and high temperature. The treatment conditions for mercerization with KOH were changed various temperatures(25, $90^{\circ}C$), concentrations(15, 20, 25, 30%. w/v) and times(30, 60, 180, 300sec). The effects of mercerization after KOH treatment estimated with tensile strength, tearing strength, shrinkage, drape stiffness, moisture regain, fiber surface, and dyeability. The optimal conditions were concentration of KOH 20%, time 180sec in low temperature and concentration of KOH 20%, time 60sec in high temperature. The results are as follows; Tensile strength, tearing strength and moisture regain were much improved than those of untreated cotton fabric. Shrinkage and drape stiffness of KOH treated cotton were more increased at $25^{\circ}C$ than $90^{\circ}C$. Fiber surface showed more rounded shape at $25^{\circ}C$ than $90^{\circ}C$. Dyeability of cotton fabrics improved by KOH treatment.

Bond Strength of Latex Modified Concretes with Surface Preparation (부착면 특성에 따른 라텍스 개질 콘크리트 부착강도)

  • Kim Sung-Hwan;Kim Kyoun-Jin;Won Chi Moon;Yun Kyong-Ku
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.445-448
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    • 2004
  • Recently, bridge deck overlay with latex modified concrete is widely applied in domestic. the capacity of bridge deck overlay depends on bond state on the surface. factors that have an effect on bond state are clean condition on the surface, absence of surface microcracking, absence of laitance, overlay curing. In this study, it is researched that characteristic of bond strength according to moisture condition on the surface and the removal method of concrete. As a result, it shows high bond strength in dry condition when w/c is $31\%$ and in moisture condition when w/c is $38\%$ respectively. characteristic of bond strength according to the removal method of concrete shows high bond strength when using water-jets rather than jackhammers.

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Moistureproof Characteristics of Woodboard Types with Surface Thermal Changes (목질 보드류의 표면 열변화에 따른 접촉각(방습) 특성)

  • Shin, Sang-Ho;Liim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.161-162
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    • 2020
  • In this study, as part of securing related data, water droplets were dropped on the upper part of the wooden board for flooring in an environment such as floor heating, and the degree of absorption according to the surface temperature change was tested. The test results showed that the contact angle of the surface was low (25℃→40℃) or the droplet was absorbed into the small plate and disappeared. The contact angle of the OSB and MDF was decreased within 30 minutes, but the surface water droplet was maintained longer than the plywood. This is because the surface is coated with hydrophobicity unlike the plywood, but moisture absorption in the cross section after the second processing will not be prevented and it will lead to defect occurrence problem.

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