• Journal of the Korean Electrochemical Society
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• v.1 no.1
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• pp.55-59
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• 1998

The water absorption in protective coatings, which may greatly influence the durability of these coatings, was studied using quartz crystal microbalance and electrochemical impedance technique. The water absorption in protective coatings and the change of coating capacitance with concentration of electrolyte were measured. The water absorption in coatings seems to be driven by osmotic pressure, and larger amount of water was absorbed in thinner coatings at initial stage of absorption. The amount of water absorbed in coatings changed with the type and crosslinking density of resin used in coating formulation. When water absorption and desorption of coating occured by exposing the coatings to electrolyte solutions of different concentration, increase in impedance caused by desorption of water was found to be higher in the case of thinner film.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.52-61
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• 1991

In this paper, the difference of the property of absorption and desorption for five species in semi-steady state are studied. The species used are listed in Table 1 and the dimension of specimen was $8\times8{\times}T$(Tangential direction)cm and tested in various conditions. A change of average moisture content with time were measured in each cycles. The results obtained are summarized as follows. When the relative humidity in air was maximum or minimum, the distribution of moisture In wood of all specimens were illustrated by exponential curves of decrease or increased from lace 10 center of wood. From the consideration of coefficient of decrease(C), the amount of moisture change of spruce was larger than the others. The pheonomenon was considered no relation to the specific gravity in air dry, but the wood structures. The velocity of the absorption and desorption for species decreased in the order spruce(Picea sitchensis) neodobam(Fagus crenata), solsong(Tsuga heterophylla), meranti(Shorea sp.) and kaesoo(Cercidiphyllum japoicum). In case of constant temperature and water vapor pressure is changed. the amount of absorbed moisture was larger than that of constant water vapor pressure and temperature vaned. In this fact, it is considered that the property of sorption of wood is strongly influenced by vapor pressure gradient than temperature gradient.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.557-566
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• 2019

Radial and tangential water diffusion in Eucalyptus globulus wood was investigated using three mature trees from a forest in Khemis Sahel (North Morocco). Absorption and desorption kinetics experiments were conducted at ambient temperature ($25^{\circ}C$) and $30^{\circ}C$, respectively, and a relative humidity of 60%. The diffusion coefficients in the two directions were determined under imposed hygrothermal conditions; they were greater in the radial direction for the absorption as well as desorption processes. Convective drying under load, preceded by reconditioning and followed up by balancing, revealed the drying conditions that corresponded to the appropriate drying schedules for E. globulus wood. This was verified by measuring the cracks and bowsbefore and after drying of boards.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.424-429
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• 2016

In this study, the carbonized boards were manufactured from different types of wood-based panel and then their moisture absorption/desorption properties were investigated and compared. The carbonization temperature was maximum $600^{\circ}C$ with 2 h maintains. Test results showed higher absorption/desorption capacity on carbonized plywood than carbonized MDF, PB, and OSB, respectively. However, carbonized MDF, OSB, and plywood had similar absorption/desorption rate per hour. It means carbonized OSB and plywood can transfer moisture into deeper side and then possibly hold more amount of water. Based on SEM images, carbonized OSB and plywood showed more like wood structure, while carbonized MDF and PB had only wood fiber or/and chunk of wood fragments. Therefore, original wood structure may affect moisture absorption/desorption capacity. In order to manufacture high moisture absorbing/desorbing carbonized board, wood structure should be considered and then carbonized.

• Journal of the Korean Society of Safety
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• v.13 no.4
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• pp.206-212
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• 1998

The water permeation in protective coatings, which may greatly influence the corrosion protective property of these coatings, was studied using the electrochemical impedance spectroscopy technique. During the absorption of water in protective coatings immersed in electrolyte solution, the change of coating capacitance with concentration of electrolyte was determined from impedance measurements. When water absorption or desorption of coatings occured by exposing the coatings to electrolyte solutions of different concentration, increase in impedance caused by desorption of water was found to be higher in the case of thicker film. The amount of water absorbed in coatings changed with concentration of electrolyte. The water taken up in coatings from the solution of lower electrolyte concentration was deserted by contact with the solution of higher concentration. The uptake of water in protective coatings varied depending on the type of coating ingredient especially binder.

• Journal of Ocean Engineering and Technology
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• v.18 no.1
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• pp.75-79
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• 2004

Organic coatings are widely used to control of the corrosion of a steel structure. The water in coatings may cause the coatings to swell, leading to the degradation of the 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 the 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 conducted under cyclic water-absorption/desorption conditions, consisting of alternative exposure to diluted 0.001M-LiCl(a$H_2O$≒1) and concentrated 10M-LiCl(a$H_2O$≒0.15). The anticorrosive performance of coatings was found to decrease in the order of urethane-urethane > urethane-epoxy > epoxy-epoxy coating.

• 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.

• Journal of Ginseng Research
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• v.6 no.1
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• pp.30-37
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• 1982

This study was conducted to investigate the water vapor permeability of packaging film, Al- foil laminated paper, and sorption properties of dehydrated and powdered foods. The results are as fellows. 1. Absorption rate of each products was greately affeoted by physicochemical properties of foods rather than initial moisture contents of the products. 2. The absorption rate of each products were in the order of freeze dried coffee, spray dried coffee, freeze drie4 ginseng extract, spray dried ginseng extract, ginger tea, black tea, citrus juice Powder and ssang wha tea. 3. Most of the products such as freeze dried coffee, spray dried coffee, freeze dried ginseng extract, ginger tea and black tea have shorter than a month of shelf life. 4. The stability of the products were greatly affected by its desorption properties than the degree of desorption of moisture. 5. Water vapor permeability of packaging materials which are laminated Al-foil with polythylene and glassin paper were mainly affected of thickness of Al-foil and polyethylene.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.624-629
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• 2012

To capture and recover carbon dioxide ($CO_2$), we impregnated honeycomb made of ceramic paper with $K_2CO_3$ and its absorption characteristics of $CO_2$ were investigated. The absorption amount of $CO_2$ on the honeycomb absorbent impregnated with $K_2CO_3$ was 13.8 wt% at a constant temperature ($70^{\circ}C$) and relative humidity (66%) condition. Because the absorption amount of $CO_2$ achieved almost the same loading ratio of $K_2CO_3$ (17.6 wt%), the absorption reaction of $CO_2$ by $K_2CO_3$ on the honeycomb absorbent seems to be going smoothly. In addition, $CO_2$ absorption breakthrough characteristics of the honeycomb absorbent were analyzed at the temperature range of $50{\sim}80^{\circ}C$, and the water vapor was fed to an absorption column before the feeding of $CO_2$ or simultaneously with $CO_2$. As a result, the absorption capacity of $CO_2$ was more enhanced using the water vapor supplying before $CO_2$ than that of simultaneous supplying. It was confirmed by temperature programmed desorption analysis that the $KHCO_3$ produced by the absorption reaction of $K_2CO_3$ and $CO_2$ is regenerated by the desorption of $CO_2$ at a temperature of about $128^{\circ}C$.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.27.1-27.1
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• 2011