• Title/Summary/Keyword: water absorption property

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흡.탈수 반복 환경에 있어서 유기도막의 방식성 평가

  • Park, Jin-Hwan;Lee, Geun-Dae;Jeon, Ho-Hwan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.262-268
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    • 2003
  • Organic coatings are widely used to control the corrosion of steel structure. The water in coatings may cause swelling or solvation of coatings, leading to the degradation of coatings. In addition, water affects the permeation of oxygen and other corrosive agents, and consequently the presence of such substances at coating-metal interface promotes corrosion of metal substrate. In this study, the anticorrosive properties of 4 types of coating, such as epoxy-epoxy, epoxy-urethane, urethane-epoxy, urethane-urethane, were evaluated. The evaluation tests were carried out under cyclic water-absorption/desorption conditions, consisting of alternative exposure to diluted 0.001M-LiCl($a_{1120}{\fallingdotseq}1$) and concentrated l0M-LiCl($a_{1120}{\fallingdotseq}0.05$). The anticorrosive performances of coatings were found to decrease in the order of urethane-urethane> urethane-epoxy> epoxy-epoxy coating.

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Effect of rheological properties on chemical absorption of carbon dioxide with MEA

  • Park, Sang-Wook;Kim, Tae-Young;Park, Byoung-Sik;Lee, Jae-Wook
    • Korea-Australia Rheology Journal
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    • v.16 no.1
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    • pp.35-45
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    • 2004
  • Rates of chemical absorption of $CO_2$ in water-in-oil (w/o) emulsion were measured in a flat-stirred vessel at $25^{\circ}C$. The w/o emulsion was composed of aqueous monoethanolamine (MEA) droplets as a dispersed phase and non-Newtonian viscoelastic benzene solutions of polybutene (PB) and polyisobutylene (PIB) as a continuous phase. The liquid-side-mass transfer coefficient ($k_L$) was obtained from the dimensionless empirical equation containing Deborah number expressed as the properties of pseudoplasticity of the non-Newtonian liquid. $k_L$ was used to estimate the enhancement factor due to chemical reaction between $CO_2$ and MEA in the aqueous phase. PIB with elastic property of non-Newtonian liquid made the rate of chemical absorption of $CO_2$ accelerate compared with Newtonian liquid.

Preparation of Porous Ceramics Sound Absorbent Material Using Sewage Sludge Slag (하수슬러지 슬래그를 이용한 다공성 세라믹스 흡음재료 제조)

  • 신대용;한상목
    • Journal of the Korean Ceramic Society
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    • v.40 no.3
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    • pp.273-278
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    • 2003
  • The effects of content and particle size of sewage sludge slag on the sound absorption was investigated and the physical$.$mechanical properties of porous ceramics for sound absorbent material was studied. The physical$.$mechanical properties of specimens have depended on sintering temperature and slag content without particle size effect of slag. As water glass content increase and particle size of slag decrease at the same slag content, physical$.$mechanical properties of them have been improved. The bulk density and compressive strength of specimens with the batch composition of 77∼89 wt% of slag content and particles with 1∼3 mm, and sintered at 1,050$^{\circ}C$ for 2 h were 1.48∼1.71 and 86∼163 kgf/$\textrm{cm}^2$, respectively. The specimens with 1∼3 mm and <1 mm of particles size showed good sound absorption property at low frequency and high frequency region. With increasing thickness of specimens, sound absorption properties at low frequency region were increased.

Effects of Stearic Acid on the Watertightness Properties of the Cementitious Materials (시멘트 재료의 수밀성에 대한 스테아르산의 영향)

  • Na, Seung-Hun;Kang, Hyun-Ju;Song, Myong-Shin
    • Journal of the Korean Ceramic Society
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    • v.46 no.4
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    • pp.365-371
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    • 2009
  • It is well known that the properties of concrete such as the compressive strength, water permeability, water tightness and durability are affected by micro-structure in hardened cement paste. Especially, for durability of concrete, watertightness of cementitious materials is the most critical property among various properties. Recently, many types of materials as organic and/or inorganic materials are used for watertightness of concrete. In this study, The effect of Stearic Acid at $0.5\;wt%{\sim}3.0\;wt%$ adding ratios on the hydration and watertightness property of cement were investigated. And we also discussed the changing of microstructure in hardened cement paste by addition of Stearic Acid. Cement paste with Stearic Acid showed improvement of watertightness by reducing of cement total pore volume and decomposition of Stearic Acid.

Physicochemical and Cooking Characteristics of Non-waxy Soft Brown Rice (연질현미의 이화학적 및 취반 특성)

  • Park, Jihye;Shin, Malshick
    • Korean journal of food and cookery science
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    • v.32 no.5
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    • pp.531-540
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    • 2016
  • Purpose: To improve the cooking quality of brown rice, newly inbred soft rice cultivars were investigated. Methods: The physicochemical properties of brown rice flour and water absorption patterns and cooking characteristics of brown rice grain were compared to Ilmi white and brown rice. Results: General composition and total dietary fiber contents of five rices were significantly different with higher ash, protein, and total dietary fiber contents in soft brown rice than white rice. The hardness of raw rice grain was higher in Ilmi brown rice than in soft brown rice. The water absorption increased rapidly in 30 min of white rice and in 4-6 h of brown rices. The apparent amylose content of soft brown rice was lower than that of Ilmi rice. The initial pasting temperature and all viscosities were significantly different, but the trend was not similar. The textural properties of hardness and roughness were higher, but adhesiveness, cohesiveness, and stickiness were lower in Ilmi brown rice than white and soft brown rices. In sensory preference test, not only textural properties, hardness, adhesiveness, cohesiveness, stickiness, and roughness, but also color, glossiness, and roasted flavor were higher in soft brown rices. Especially soft brown rice B showed the best cooking quality among all rices. Conclusion: The results of the study suggested that soft brown rice is developed for cooking with high nutritional and functional quality.

Evaluation of Water Resistance Properties of Pulp Mold depending on the Types of Raw Materials and the Additives (원료종류 및 첨가제 처리에 따른 펄프몰드의 수분 저항성 평가)

  • Sung, Yong Joo;Kim, Hyung Min;Kim, Dong Sung;Lee, Ji Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.112-119
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    • 2015
  • The pulp mold attract the increasing concern as recyclable, biodegradable, and eco-friendly packaging materials. In order to broaden the applicability of the pulp mold as substitutes of the expanded styrofoam, the properties of various raw materials for the pulp mold were evaluated and the way for improving water resistance properties of the pulp mold were also tested by applying some additives. The higher value in the fines contents and in the water retention value were shown for the TMP (thermomechanical pulp), which resulted in the bulkier pulp mold with the higher moisture absorption property. In case of water resistance properties, the pulp mold made of white ledger stock showed the higher value in water contact angle and very slow water absorption rate. The addition of oil palm EFB fiber showed the improvement in the water resistance of the pulp mold made of UBKP. The effects of various additives on the improvement in the water resistance properties of the pulp mold were tested by using AKD, PVAm, epoxy resin. The application of AKD leaded to the higher increase in the water resistance. The results in this study showed the effects of AKD for the pulp mold could be improved and optimized by the application with fixing agent and by the ageing treatment after production.

An experimental study on the preparation and property of the sintering aggregate using fly ash (플라이애쉬를 이용한 소성골재의 제조 및 특성에 관한 연구)

  • 박대영;김도수;박종현;임채영;노재성
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.239-244
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    • 1998
  • Fusion temperature of fly ash was determined with wasted glass wool and borax using ash fusion determinator, 0.5wt% of bentonite and water glass used as binder, 50wt% of wasted glass wool added to fly ash, fusion temperature of fly ash was 1, 156$^{\circ}C$. Pellet was prepared, and then sintered at 1, 00$0^{\circ}C$ and 1, 10$0^{\circ}C$. Water-absorption rate, specific gravity, porosity and pore structure of sintering aggregate was determined.

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Dyeing Properties and Functionality of Hot-water Extract from Juniperus chinensis Heartwood (향나무 심재 열수추출물의 염색성과 기능성)

  • Nam, Ki Yeon;Lee, Jung Soon
    • Textile Coloration and Finishing
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    • v.25 no.3
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    • pp.181-193
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    • 2013
  • The purpose of this study is to investigate dyeing properties and functionality of cotton and silk fabrics dyed with hot-water extract from Juniperus chinensis heartwood. Water-soluble dye of Juniperus chinensis heartwood extracted with distilled water was expressed YR color series. Dye uptake of cotton continued to increase according to the increase of the dye concentration. Its variation trends were shown to be similar to the isothermal absorption curve of the Freundlich. Dye uptake of silk was better than cotton, increased depending on increasing concentration of the dye, dyeing time and temperature. Its variation trends were shown to be similar to the isothermal absorption curve of the Langmuir. As the pH increased, the dye uptake of fabrics reduced and showed increased on red tinge. Colors of the dyed fabrics were various, depending on dye concentration and the mordant type and mordant concentration. Washing fastness, light fastness and perspiration fastness were not good. However, rubbing and dry cleaning fastness showed relatively good grade. Dyed fabrics of ultraviolet-cut ability and deodorant ability were improved. And dyed fabrics showed antimicrobial abilities of 99.9% against Staphylococcus aureus.

The Change of Comfort Properties of Cotton and Hanjee Fabrics with Natural Dyeing and Functional Mineral Treatment (면섬유 및 한지섬유의 자연염색 및 기능성광물처리에 의한 쾌적성의 변화)

  • Kim, Sung-Hee
    • Fashion & Textile Research Journal
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    • v.12 no.2
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    • pp.219-223
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    • 2010
  • In this study, the comfort properties of cotton and Hanjee fabrics dyed with Inonotus obliquus and treated with illite were evaluated and compared. Results were as follows; 1) W/T values and WC/W values of cotton and Hanjee fabrics were decreased when they were dyed with Inonotus obliquus and treated with illite. 2) Although air permeability of cotton fabrics was higher than that of Hanjee fabrics, air permeability of cotton and Hanjee fabrics dyed with Inonotus obliquus and treated with illite was decreased. 3) Thermal conductivity of cotton and Hanjee fabrics dyed with Inonotus obliquus was increased whereas thermal retain property was decreased. 4) Water absorption of Hanjee fabrics was higher than that of cotton fabrics. Water absorption of cotton and Hanjee fabrics dyed with Inonotus obliquus and treated with illite was increased. 5) Deodorization rate of Hanjee fabrics was greater than that of cotton fabrics.

An Experimental Study on the Relationship Between Physical Property of Recycled Aggregates and an Amount of Mortar Attached to the Original Aggregate (재생골재의 물리적 성질과 모르타르 부착양의 관계에 대한 실험적 연구)

  • Kim Hyun-Ho;Yang Keun-Hyeok;Kang Kyung-In;Jung Sang-Jin;Chung Heon-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.141-144
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    • 2005
  • This paper reports the results of experimental study on the effect of an amount of mortar attached to the surface of original aggregate on the physical properties of recycled aggregates such as specific gravity, and water absorption. An amount of attached mortar was evaluated by hydrochloric acid precipitation method. Test results indicated that a water absorption of recycled aggregates was proportional to the amount of mortar attached to the original aggregate.

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