• Title/Summary/Keyword: Moisture Analysis

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Comparative Analysis of Dynamic Moisture Movement Testers

  • Lee, Duck-Weon;Shim, Woo-Sub;Lim, Ho-Sun
    • Journal of Fashion Business
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    • v.15 no.6
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    • pp.40-55
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    • 2011
  • The purpose of this research is to review testing principle, testing design and experimental results of the four dynamic moisture movement testers. The research analyzes Moisture Manager Tester (MMT), Alambeta Instrument, Dynamic Surface Moisture Movement Tester, and Gravimetric Absorbent Testing Method based on American Society for Testing and Material (ASTM) E 96 which is an international standard testing method. Although many of researches use ASTM E 96 to measure moisture movement on a fabric, it has several weaknesses, such as long experimental time and a physical change of sample by a holder of the frame. Hence, lots of researchers have studied and developed the new measurement systems measuring moisture management on a fabric or garment and ultimately mimic heat energy and perspiration created by the human body. These moisture management systems use a variety of parameters, such as electricity, color, and sensor to measure their movement in the fabric. Through comparison with the existing tester (ASTM E 96), the research recognizes the strength and weakness in the dynamic moisture movement testers.

Analysis on Adequacy of the Satellite Soil Moisture Data (AMSR2, ASCAT, and ESACCI) in Korean Peninsula: With Classification of Freezing and Melting Periods (인공위성 기반 토양 수분 자료들(AMSR2, ASCAT, and ESACCI)의 한반도 적절성 분석: 동결과 융해 기간을 구분하여)

  • Baik, Jongjin;Cho, Seongkeun;Lee, Seulchan;Choi, Minha
    • Korean Journal of Remote Sensing
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    • v.35 no.5_1
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    • pp.625-636
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    • 2019
  • Soil moisture is a representative factor that plays a key role in hydrological cycle. It is involved in the interaction between atmosphere and land surface, and is used in fields such as agriculture and water resources. Advanced Microwave Scanning Radiometer 2 (AMSR2), Advanced SCATterometer (ASCAT), and European Space Agency Climate Change Initiative (ESACCI) data were used to analyze the applicability and uncertainty of satellite soil moisture product in the Korean peninsula. Cumulative distribution function (CDF) matching and triple collocation (TC) analysis were carried out to investigate uncertainty and correction of satellite soil moisture data. Comparisons of pre-calibration satellite soil moisture data with the Automated Agriculture Observing System (AAOS) indicated that ESACCI and ASCAT data reflect the trend of AAOS well. On the other hand, AMSR2 satellite data showed overestimated values during the freezing period. Correction of satellite soil moisture data using CDF matching improved the error and correlation compared to those before correction. Finally, uncertainty analysis of soil moisture was carried out using TC method. Clearly, the uncertainty of the satellite soil moisture, corrected by CDF matching, was diminished in both freezing and thawing periods. Overall, it is expected that using ASCAT and ESACCI rather than AMSR2 soil moisture data will give more accurate soil moisture information when correction is performed on the Korean peninsula.

Soil Moisture Measurements and Correlation Analysis to Understand the Runoff Generation Process for a Bumrunsa Hillslope of Sulmachun Watershed (설마천 범륜사 사면 유출과정의 이해를 위한 실측토양수분 상관도 분석)

  • Kim, Sang-Hyun;Kang, Mi-Jeong;Kwak, Yong-Seok
    • Journal of Korea Water Resources Association
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    • v.44 no.5
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    • pp.351-362
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    • 2011
  • The soil moisture measurements and correlation analysis are presented to improve understanding the hydrological process at the hillslope scale. The rainfall events is a main driver of soil moisture variation, and its stochastic characteristic need to be properly treated prior to the correlation analysis between soil moisture measurements. Using field measurements for two designated periods during the late summer and autumn seasons in 2007 obtained from the Bumrunsa hillslope located at the Sulmachun watershed, prewhitened correlation analysis were performed for 8, 14, 7 and 7 relationships representing the vertical, lateral, recharge and return flows, for two designated periods, respectively. The analysis indicated both temporal and spatial variation patterns of hydrological processes, which can be explained by the relative contribution of matrix and macropore flows and the impact of transect topography, respectively.

Formaldehyde Emissions and Moisture Content Change of Wood Composites during Bake-out

  • Lee, Young-Kyu;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.2
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    • pp.101-109
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    • 2012
  • Wood composites are a hygroscopic material and have ability to exchange its moisture content with air. This study investigated the formaldehyde emission and moisture content change of four wood composites (particleboard (PB), medium density fiberboard (MDF), high density fiberboard (HDF), laminated HDF (L-HDF)) as a function of bake-out temperature and time. The composites were baked out for 1, 3, 5, 7, 10, 14, 21, and 28 days at temperatures of $20{\pm}2$, $35{\pm}2$, and $50{\pm}2^{\circ}C$ in a dry oven. The moisture content change was used to determine the emission bake-out of the composites. Best bake-out time results were obtained with after 7 days all composites. Formaldehyde emission values of composites decreased with decreasing moisture content for both temperatures. The formaldehyde emission results of bake-out temperature 35 and $50^{\circ}C$ showed a similar tendency.

A simple practical method for determination of moisture transfer coefficient of mature concrete using a combined experimental-numerical approach

  • Chari, Mehdi Nemati;Shekarchi, Mohammad;Ghods, Pouria;Moradian, Masoud
    • Computers and Concrete
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    • v.18 no.3
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    • pp.367-388
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    • 2016
  • In this paper, a simple practical method is introduced in which a simple weight measurement of concrete and finite element numerical analysis are used to determine the moisture transfer coefficient of concrete with a satisfactory accuracy. Six concrete mixtures with different water-to-cementitious material (w/cm) ratios and two pozzolanic materials including silica fume and zeolite were examined to validate the proposed method. The comparison between the distribution of the moisture content obtained from the model and the one from the experimental data during both the wetting and drying process properly validated the performance of the method.With the proposed method, it was also shown that the concrete moisture transfer coefficient considerably depends on the pore water saturation degree. The use of pozzolanic materials and also lowering w/cm ratio increased the moisture transfer coefficient during the initial sorption, and then, it significantly decreased with an increase in the water saturation degree.

Finite Element Analysis for Drying Process of Ceramic Electric Insulator Considering Heat and Moisture Transfer (열 및 습도전달을 고려한 세라믹 애자 건조공정의 유한요소 해석)

  • Geum, Yeong-Tak;Jeong, Jun-Ho;Kim, Jun-Han
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.1
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    • pp.36-46
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    • 2001
  • Finite element analyses of the ceramic drying process are performed. The heat and moisture movements in green ceramics caused by temperature gradient, moisture gradient, conduction, convection and evaporation are considered. The finite element formulation for solving the temperature and moisture distributions which not only change the volume but also induce the hygro-thermal stress is carried out. In order to verify the formulation, the drying process of a ceramic electric insulator is simulated. Temperature distribution, moisture distribution, and hygro-thermal stress are compared with those of other researcher. Good agreements are achieved.

Effects of Moisture Content on Non-Fracture Dynamic Properties and Fracture Quality of Pacific Whiting Surimi

  • Esturk, Okan;Park, Jae-Won;Raik, Moo-Yeol;Kim, Byung-Yong
    • Food Science and Biotechnology
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    • v.15 no.6
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    • pp.856-859
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    • 2006
  • The effects of moisture content on non-fracture dynamic properties and fracture gel quality of Pacific whiting surimi were investigated to determine their relationships. Surimi samples were tested at various moisture contents (75, 78, and 81 %). Torsion test showed that shear stress decreased rapidly and strain values decreased gradually as moisture concentration increased. Dynamic storage modulus (G') also decreased as moisture content increased. A strong positive correlation ($R^2=0.90$ to 0.99) was found between the G' measured at temperatures between 10 and $45^{\circ}C$ and fracture stress values. The results indicate that dynamic rheological measurements could be used as a tool for early gel quality assessment.

Modeling of Moisture Diffusion Coefficient with Porosity in Concrete (공극률 변화를 고려한 콘크리트의 수분확산계수 모델)

  • 강수태;전상은;김진근;김성욱
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.321-326
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    • 2003
  • The nonlinear humidity distribution occurs due to the moisture diffusion when a concrete is exposed to an ambient air. These nonlinear humidity distribution induces shrinkage cracks on surfaces of the concrete. Because shrinkage cracks largely affect the durability and serviceability of concrete structures, the moisture diffusion in concrete must be investigated. The purpose of this paper is to propose a model of the moisture diffusion coefficient that governs moisture diffusion within concrete structures. To propose the model, numerical analysis were performed based on several experiments. Because the moisture diffusion coefficient is changed with aging, especially at early ages, the proposed model includes aging effect by terms of the porosity as well as the humidity of concrete.

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Patterns between wall pressures and stresses with grain moisture on cylindrical silo

  • Kibar, Hakan
    • Structural Engineering and Mechanics
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    • v.62 no.4
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    • pp.487-496
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    • 2017
  • The focus of this study were to investigate patterns between wall pressures and stresses with grain moisture of soybean and rice varieties widespread cultivated in Turkey in order to determine needed designing parameters for structure analysis in silos at filling and discharge. In this study, the wall pressures and stresses were evaluated as a function of moisture contents in the range of 8-14% and 10-14% d.b. The pressures and von Mises stresses affected as significant by the change of grain moisture content. The main cause of pressure and stress drops is changed in bulk density. Therefore is extremely important bulk density and moisture content of the product at the structural design of the silos. 4 mm wall thickness, were determined to be safe for von Mises stresses in both soybean and rice silos is smaller than 188000 kPa.

Application of Dielectric Spectroscopy Measurements for Estimating Moisture Content in Power Transformers

  • Ekanayake, Chandima;Gubanski, Stanislaw M.;Fernando, M.A.R.M.
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.3
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    • pp.81-89
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    • 2004
  • Frequency Domain Spectroscopy (FDS) measurements were performed on pressboard samples containing different moisture contents and on insulation system of power transformers. The results were used for evaluating sensitivity of the so-called X - Y model, which is applied for estimating moisture content in transformer insulation using the results of FDS measurements. Based on the observations of this analysis a simplified model, called X model, was introduced in which the presence of spacers in transformer insulation has been neglected. Finally, reliability of the X model was assessed by comparing estimates of moisture contents based on FDS measurements on field installed power transformers with moisture contents obtained from chemical analyses of their oil samples.