• Title/Summary/Keyword: Moisture Permeability

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Enhancement of Oxygen and Moisture Permeability with Illite-Containing Polyethylene Film

  • Seong, Dong Min;Lee, Hyesun;Chang, Jeong Ho
    • Journal of the Korean Ceramic Society
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    • v.56 no.6
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    • pp.601-605
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    • 2019
  • This work reports the preparation of ceramic hybrid films with illite-polyethylene composites analyzed as a function of concentration of added illite in polyethylene. The enhancement of oxygen and water-vapor transmission rate of illite-polyethylene film was evaluated to determine its influence on the freshness in fruit packaging. Particle size of illite materials was controlled in the range of 1~10 ㎛ and then mixed with LDPE to form the masterbatch. Ceramic hybrid films were prepared through a blown film making process. To determine the dispersity and abundancy of illite materials in the polyethylene matrix, various characterizations of illite-PE hybrid masterbatch and films were performed using SEM, TGA, and FT-IR. The oxygen and water-vapor transmission rate of illite-polyethylene film was found to be two times higher than that of LDPE film.

Failure Predict of Standard Sand Model Slope using Compact Rainfall Simulation (소형 인공강우 장치에 의한 표준사 모형사면의 붕괴 예측)

  • Moon, Hyo Jong;Kim, Dae Hong;Jeong, Ji Su;Lee, Seung Ho
    • Journal of Korean Society of Disaster and Security
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    • v.8 no.2
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    • pp.21-26
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    • 2015
  • This study analyzes the failure predict of model slope due to changes in ground condition followed by heavy rainfall with a simulated rainfall system. the movement of a slope from the rainfall penetrating the unsaturated soil is investigated with respect to various conditions of pore-water pressure, earth pressure and moisture content, considering rainfall duration and permeability.

The Physical Properties of Cotton Fabric Pretreated with Skim Milk Powder (탈지분유 전처리에 의한 면직물의 물성)

  • Lee Su Min;Song Wha Soon
    • Textile Coloration and Finishing
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    • v.17 no.1
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    • pp.52-59
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    • 2005
  • The purpose of this study is to establish the scientific data of cotton fabric pretreated with skim milk powder and to improve the dyeability. The surface monophology, add on, whiteness, stiffness, air permeability, moisture regain and absorption of cotton fabrics were evaluated by varying concentration of SMP to get the optimal conditions in pretreatment. FT-IR of cotton fabrics pretreated with SMP were measured. Amino acid compositions, viscosity of SMP were evaluated. The K/S values by varying concentration of cinnamon cassia and subtract of dyed SMP-C were measured. I attempted to evalute the color fastness of untreated and AI. The results are as follow; The optimal concentration of SMP was 9%(w/v) to be pretreated with cotton fabrics. From FT-IR spectrum, formation of -NH$_2$ and -COOH was verified by SMP-C. Denaturalization of protein and condensation of carbohydrate, fat, etc. were found in a measurement of amino acid and viscocity. The K/S value of cotton fabrics pretreated with SMP was higher than that of untreated. Most of the color fastnesses were great.

Influence of Methylcellulose on Properties of Wheat Gliadin Film Cast from Aqueous Ethanol

  • Song, Yihu;Li, Lingfang;Zheng, Qiang
    • Food Science and Biotechnology
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    • v.18 no.4
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    • pp.910-916
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    • 2009
  • Present work was focused on the influence of methylcellulose (MC) on steady rheology of wheat gliadin solution and the properties of glycerol plasticized gliadin films. The presence of MC below 0.99 wt% improved viscosity and flow activation energy of the 10 wt% gliadin solution significantly. In the casting films containing 0.2 g glycerol/g dry protein, the MC component aggregated in the gliadin matrix. The blend films containing less than 7.7 wt% MC exhibited higher Young's modulus (E) and tensile strength (${\sigma}_b$) and lower elongation at break (${\epsilon}_b$) in comparison with the pure gliadin film, which was related to the intermolecular interaction between MC and gliadins, the brittle fracture of the aggregated MC component, and the increase in glass transition temperature ($T_g$) of the gliadin phase. Increasing MC content led to a slight increase in water vapor permeability (WVP) without significant influence on the moisture absorption (MA).

Experimental studys about Compaction in Soil (흙의 다짐에 관한 실험적 연구)

  • 이석찬
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.14 no.2
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    • pp.2661-2667
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    • 1972
  • In the construction of earth dam, embankment, highway by filling, a compaction is to increase the density of applying pressure. By compaction interspaces between the soil graivos decrease so that density and adhesion increase but void and permeability decrease. Good compaction results in higher stablilty. The effect of the compaetion depends on a number of factors, of which the most important are soil charactesistics. Water content, and external force. In this study discussed is about sandy loam that since, with indentical force exerted and indentical compaction method, the effect of the compaction will be different due to the soil characteristics, the change of optimum moisture content and of maximum dry density by compaction yields difference in Compaction for a same sample.

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Study on permeability improved multi-layer encapsulation on Ethylene Terephthalate(PET) (PET 기판위의 투습율 향상을 위한 다층 보호막에 관한 연구)

  • Han, Jin-Woo;Kang, Hee-Jin;Kim, Jong-Yeon;Kang, Dong-Hun;Han, Jung-Min;Oh, Yong-Cheul;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.313-314
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    • 2006
  • In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated Results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLED) application.

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Novel Recycling Technology of Ultra-fine Fibrous Materials

  • Kim, Seong-Hun;Oh, Kyung-Wha;Lee, Shin-Kyung
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.209-209
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    • 2006
  • Ultra-fine fibers are spun by expensive fiber spinning technology using special spinnerets. Ultra-fine fibrous materials have attracted considerable attentions because of their potential applications as high performance wiping cloths, water absorbent sound proofing materials and moisture transfer sporting good. However, production expense of ultra-fine fibers is 5 to 7 times higher than general textile materials. The objective of this research is to develop cost-effective recycling process to produce multi-functional ultra-fine fibrous material in terms of the development of garnetting and carding machines for ultra-fine fibrous material waste and scrap. The efficiency of sound absorption for the recycled polyester nonwoven increased with decreasing length and thickness of component fibers, which was attributed to the reduction of air permeability. It is expected that high value and cost-effective textile products are developed using ultra-fine fibrous wastes and that sound proofing material and oil absorbent f

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Shrinkages of Prefrozen or Presteamed Wood (전처리(前處理) 목재(木材)의 수축율(收縮率) 변화(變化))

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.1
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    • pp.66-71
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    • 1994
  • To increase drying rate and reduce drying degradation, pretreatments such as prefreezing and presteaming have been widely used in wood industries. Presteaming lumbers prior to kiln drying is known positively to improve its permeability, to increase diffusion coefficient and to reduce discoloration, but negatively to increase collapse. Prefreezing lumbers prior to kiln drying is also known to reduce significantly its drying defects and its shrinkages. Thus it is no doubt that the pretreated lumbers shrink diversely from the untreated. In this study the shrinkage behaviors of the pretreated specimens are investigated by drying two tropical hardwoods (Apitong and Taun) in three different dying conditions: high temperature and slow drying rate (drying in a closed cylinder), high temperature and rapid drying rate (drying in an oven) and low temperature and slow drying rate(drying at room temperature). The prefrozen specimens show the least volumetric shrinkages in most drying conditions. The specimens dried in cylinders shrink most among all drying conditions. In general the pretreated specimens reached the 30 % moisture content faster than the untreated by about 30 %.

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Aeration Factor Used To Design The Container Type of Biopile Systems for Small-Scale Petroleum-Contaminated Soil Projects

  • Jung, Hyun-Gyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.2
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    • pp.316-319
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    • 2011
  • Biopiles which offer the potential for cost-effective treatment of contaminated soils are above-ground, engineered systems that use oxygen to stimulate the growth and reproduction of aerobic bacteria for degradation of the petroleum constituents adsorbed to soil in excavated soils. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. Inside the biopile, microbially mediated reactions by blowing or extracting air through the pipes can enhance degradation of the organic contaminants. The influence of a aeration system on the biopile performance was investigated. Air pressure made to compare the efficiency of suction in the pipes showed that there were slightly significant difference between the two piles in the total amount of TPH biodegradation. The normalised degradation rate was, however, considerably higher in the aeration system than in the normal system without aeration, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile.

Development of Washable Wool Using Environmental-friendly Spray UV-cure Finishing Technique - Using Photocrosslinkable Polymerr Dextran-methacrylate- (환경친화적 Spray UV-Cure 가공 기술을 이용한 물세탁 모직물(washable wool)의 개발 -광가교 고분자인 dextran-methacrylate를 이용하여-)

  • 김신희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.11
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    • pp.1507-1515
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    • 2004
  • Washable wool was developed using environmental-friendly spray UV-cure technique. Photocrosslinkable polymer, dextran-methacrylate, was synthesized starting from natural biopolymer, dextran. The aqueous solution of dextran-methacrylate was applied to wool fabric with various concentrations to find out the optimum condition in minimizing felting shrinkage. The wool fabric subsequently cured by 365 nm UV, The effects of UV-cure time and photoinitiator concentration on felting behavior of wool were examined. As the concentration of dextran-methacrylate increased, the felting shrinkage decreased gradually. At concentration 0.5g/ml, the felting shrinkage of wool was negligible. Other properties such as air permeability, moisture content, wrinkle recovery, thickness and wettability were also evaluated. The surface coating of dextran polymer onto wool fiber was identified by SEM.