• Title/Summary/Keyword: moisture adsorption / desorption

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Moisture Adsorption and Desorption Property of the Wallpaper using Natural Substance (천연 물질을 적용한 벽지의 흡·방습 성능에 관한 연구)

  • Hwang, Hye-jin;Kim, Dong-kwon;Jeong, Jae-sik;Bae, Jin-seok
    • Textile Coloration and Finishing
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    • v.27 no.3
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    • pp.210-218
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    • 2015
  • In this study, natural substance and mineral materials was used for architectural interior wallpaper. Because natural substance and minerals are environment-friendly material with moisture adsorption and desorption properties. Natural substance and mineral materials was evaluated in moisture adsorption and desorption properties. Also, in the diatomite, the pores were observed on SEM photographs. Thus, it is supposed that moisture adsorption and desorption properties were influenced by the microstructure of the pore. The wallpaper according to the ratio of the mixture was analyzed for physical properties and moisture adsorption & desorption properties. As a result, we developed a wallpaper having excellent hygrothermal performance.

Hygroscopic Characteristic of Gypsum Boards Using Porous Materials (다공성 원료를 사용한 석고보드의 흡습 특성)

  • Jeong, Eui-Jong;Lee, Jong-Kyu;Cheong, Deock-Soo;Chu, Yong-Sik;Song, Hun
    • Korean Journal of Materials Research
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    • v.19 no.10
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    • pp.538-543
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    • 2009
  • Active clays, Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic gypsum boards. Pohang active clay and Cheolwon diatomite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Moisture adsorption content of gypsum board with 10% active clay(P1) was 62.0 g/m$^2$, and moisture desorption content was 50.2 g/m$^2$. Moisture adsorption content of gypsum board with 10% diatomite(P) was 59.5 g/m$^2$, and moisture desorption content was 49.0 g/m$^2$. Moisture adsorption contents of gypsum boards with porous materials were higher than that moisture desorption contents of gypsum board without porous materials. Correlation coefficient between surface area and moisture adsorption content of gypsum boards was 0.98. Also, correlation coefficient between surface area and moisture desorption content of gypsum boards was 0.97. Moisture adsorption and desorption contents were influenced by surface area and pore volume of the gypsum boards, and surface area had a larger effect on moisture adsorption and desorption.

Hygroscopic Characteristic of Hydrothermal Reacted Panels Using Porous Materials (다공성 원료를 사용한 수열합성 패널의 흡습 특성)

  • Chu, Yong-Sik;Kwon, Choon-Woo;Song, Hoon;Lee, Jong-Kyu
    • Journal of the Korean Ceramic Society
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    • v.45 no.12
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    • pp.832-838
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    • 2008
  • Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic panels. Moisture adsorption and desorption of porous materials were investigated and hydrothermal method was applied to fabricate panels. Cheolwon diatomite and Pohang zeolite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Correlation coefficient between surface area and moisture adsorption content of porous materials was 0.93. Moisture adsorption contents were influenced by surface area and pore volume of panels, and surface area more effected on moisture adsorption. Correlation coefficient between surface area and moisture adsorption content of panels was 0.86. Moisture adsorption content of panel with 10% Pohang zeolite was $180\;g/m^2$ and that of 10% Cheolwon diatomite was $170\;g/m^2$. Moisture desorption content of panel with 10% Pohang zeolite was $105\;g/m^2$. Moisture adsorption contents of panel with porous materials were higher than that of panel without porous materials.

EMC/ERH of Rough Rice and Brown Rice (벼 및 현미의 평형함수율/평형상대습도)

  • Choi B. M.
    • Journal of Biosystems Engineering
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    • v.30 no.2 s.109
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    • pp.95-101
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    • 2005
  • Adsorption and desorption experiments were carried out on rough rice and brown rice (Nampyung) at 5, 15, 25, 35, $45^{\circ}C$ for moisture contents between 8.7 and $25\%$ (db). The method employed was to measure the equilibrium relative humidity (ERH) of air in contact with the grain under static conditions, using an electronic hygrometer The effects of temperature and moisture contents were investigated, and the measured values were fitted to the modified Henderson, the modified Chung-Pfost, the modified Halsey and the modified Oswin model. The ERHs of rough rice and brown rice decreased with an decrease in moisture content and temperature, and the effects of temperature was no significant at moisture content of $25\%$ (db). Equilibrium moisture content (EMC) of brown rice was higher than rough rice at same temperature and relative humidity. Desorption EMC is higher than the adsorption, but there is no significant difference between desorption and adsorption EMC in moisture content near $25\%$ (db) at rough rice and near 9, 21 and $25\%$ (db) at brown rice. The modified Oswin model was the best in describing the adsorption EMC and the modified Chung-Pfost model was the best in describing the adsorption ERH of rough rice. The modified Oswin model was the best in describing the adsorption EMC/ERH of brown rice. The modified Chung-Pfost model was the best in describing the desorption EMC/ERH of rough rice and brown rice.

Performance Evaluation of Water Vapour Adsorption/Desorption Property for a Building Material by Mock up Test (실물시험을 통한 흡방습 건축자재의 성능평가)

  • Kim, Hea Jeong;Song, Kyoo Dong;Lee, Yun Gyu
    • KIEAE Journal
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    • v.9 no.2
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    • pp.53-58
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    • 2009
  • There are increasing developments and uses of functional building materials are recently developed and introduced to the test method for the materials. Especially, moisture problem has a major role are also being established in indoor air quality problems. The purpose of this study is to evaluate the water vapour adsorption/desorption property of a ceiling material. The variation of the temperature and moisture were measured with the application materials by mock up test based on JIS 1470-1. The result shows that water vapour adsorption/desorption property of ceiling material is appeared in changes of moisture adsorption and desorption in comparison with that of a general ceiling material. Therefore, in case of decreasing and increasing in humidity, these materials can be used as an finishing material to sustain comfort condition.

Vapor Permeability and Moisture Gradient on a Paulownia Wood for Inside Material of Furniture Making

  • Lee, Won-Hee
    • Journal of the Korea Furniture Society
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    • v.19 no.6
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    • pp.447-451
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    • 2008
  • This study was carried out to know the difference of vapor transmission on the thickness of Paulownia wood(Paulownia tomentosa). The behavior of moisture transmission of wood thickness direction is generally estimated by vapor permeability and vapor transmission resistance. In general, Paulownia wood is known to use of inside material for furniture making, because of the excellent ability of vapor adsorption and/or desorption. Quarter sawing Paulownia wood material is prepared and the thickness is 6.0mm, 7.0mm, 8.0mm, 9.0mm, 10.0mm, respectively. The measurement of vapor transmission were conducted by the "cup method" in accordance with JIS(Japanese Industrial Standard) Z-0208. The experiment was made in the condition of 49.8mmHg vapor pressure difference and $40^{circ}C$ at constant temperature. From the experiment results, it was considered that Paulownia wood is very stable on moisture variation and any other material conditions. In this experiment we found that the vapor permeability and vapor permeance was reduced with the increase of wood thickness to vapor direction and vapor transmission resistance and specific vapor transmission resistance was increased with the increase of wood thickness to vapor direction. Besides moisture contents of adsorption and desorption side were about 5 percent and 14 percent, respectively. Mean value was 9.5 percent and about 10 percent in dry oven method. Moisture gradient was reduced with the increase of wood thickness for a small moisture difference of adsorption and desorption side.

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Hygroscopic Characteristic of Hydrothermal reacted Panels using Porous Materials (다공성 원료와 수열합성으로 제조한 건축 내장용 패널의 흡방습 특성)

  • Kwon, Choon-Woo;Chu, Yong-Sik;Song, Hun;Lee, Jong-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.705-708
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    • 2008
  • Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic panels. Moisture adsorption and desorption of porous materials were investigated and hydrothermal method was applied to fabricate panels. Cheolwon diatomite and Pohang zeolite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Moisture adsorption contents were influenced by surface area and pore volume of panels, and surface area more effected on moisture adsorption. Moisture adsorption content of panel with 10% Pohang zeolite was 180g/m$^2$and that of 10% Cheolwon diatomite was 170g/m$^2$. Moisture desorption content of panel with 10% Pohang zeolite was 105g/m$^2$. Moisture adsorption contents of panel with porous materials were higher than that of panel without porous materials.

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Cracking of Rice Caused by Moisture Migration during Storage (쌀의 저장중 수분이동에 의한 균열현상에 관한 연구)

  • Mok, Chul-Kyoon;Lee, Sang-Ki
    • Korean Journal of Food Science and Technology
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    • v.31 no.1
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    • pp.164-170
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    • 1999
  • Cracking of rice caused by moisture migration during storage under different relative humidity conditions was investigated for the establishment of safe storage condition of rice. Rice was cracked when a large difference in equilibrium relative humidity $({\Delta}ERH)$ between the rice and the environment was present. External and internal cracks were generated as the results of moisture desorption and adsorption, respectively. The external cracks by moisture desorption generated in all directions and shaped irregularly, while the internal cracks by moisture adsorption did in radial direction and showed a typical shape. The cracking trend could be analyzed by the Weibull function, and the cracking constant increased with ${\Delta}ERH$. The frequency of cracked rice increased linearly with In $({\Delta}ERH)$. The critical crack-inducing ${\Delta}ERH$ was $11.3{\sim}16.4%$ during desorption and $10.8{\sim}17.1%$ during adsorption. A diagram for the safe storage of rice was developed with respect to the initial moisture content and the water activity of rice.

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Experimental Examinations on the Phenomenon of Transfer and Moisture Diffusion in Wood (목재내(木材內)의 수분확산(水分擴散) 및 전달현상(傳達現象)에 관한 실험적 검정(檢定))

  • Lee, Weon-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.1
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    • pp.75-80
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    • 1996
  • The purpose of this study is to clarify the mechanism of moisture transfer depend on the thickness of the spruce(Picea sitchensis Carr.). Therefore, as the basic research of moisture transmission, the amount of moisture transmission and the moisture distribution in specimens and temperature of it's surfaces in vapor transmission process were investigated. The experiment was conducted in a steady state. and the moisture distribution was measured by knife cutting and weighing the specimens. The following conclusions were obtained ; 1. It can be found that distribution of moisture in the specimen can be approximated by two different straight lines intersecting at nine or ten percent moisture content. The amount of moisture movement defends on the gradient of moisture in the wood. 2. It is investigated that the wood surface moisture contents(MCs) are less for thinner specimens than for thick ones on the absorption side. On the other hand, the wood surface MCs are greater for thinner specimens than for thick ones on the desorption side. The main factor that affects the EMC of wood would be temperature when the relative humidity of atmosphere is constant. The specimen generate heat with the absorption and desorption process. In addition, the velocities of moisture transmission varied with the thicknesses of specimens. If the temperature of wood becomes greater, its MC decreases. Then the difference between surface MC and EMC of adsorption and desorption side becomes greater for thinner specimens. Therefore it is considered that the coefficients of moisture transfer decreases with the increases of the specimens' thicknesses.

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Comparing Performances of Natural Finishing Material for Finish on Earth Wall (흙벽 마감을 위한 천연 마감재 성능 비교 연구)

  • Hwang, Hey zoo;Kang, Nam Yi;Kim, Tae Hoon
    • KIEAE Journal
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    • v.12 no.5
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    • pp.71-76
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    • 2012
  • As reviewed of developments of Korean earth architecture, earth-made buildings have been dwindled gradually since "the new community movement" and earth have been recognized as materials which are not so good to human health and in result, earth-related techniques have been also forgotten. However, recently the earth architecture has been more attracting back many attentions thanks to the people who are interested in health and wellbeing and the earth related techniques or skills got keenly required. The present study has investigated and reproduced earth finishing materials which are based on natural materials as basic stuffs to use them as the finishing materials of the modern earth architecture. For the test, the finishing materials have been divided roughly into sorts of pastes and oils. In case of applying finishing materials onto earth surfaces, the moisture permeability test was conducted to measure a water-absorbing speed, and at the case of using finishing materials for interior works moisture adsorption/desorption test was performed to verify the indoor humidity regulation ability, and further a test to check whether to be stained when contacted with the finishing materials, was conducted. If there is not any stain it might be recognized to be high quality of moisture adsorption/desorption and so seaweed pastes or starches might be used for paste finishing materials and for natural oils, beans are desirable in practical ways. As low-quantity of moisture adsorption materials, linseed oil is most desirable and also beaned water over75% are thought to be useful.