• 한국가구학회지
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• 제27권2호
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• pp.91-95
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• 2016

This study was conducted to investigate the relationship between water absorption (or hygroscopic property) and growth rate of rubra oak (Quercus rubra) from 5 different origins of seed (Carleton, Simcoe, Chatham, Bancroft, Unknown). Water absorption at cross section of Quercus rubra was $0.43{\sim}0.92g/cm^2$ and the property was not related with growth rate. Overall equilibrium moisture content of rubra oak were 11.35~11.56% and 15.15~15.83% at $40^{\circ}C$ with 75% and 90% relative humidities, respectively. There was no relationship between growth rate and moisture content(hygroscopy) in rubra oak. Based on the results, Rubra oak can be classified as a low hygroscopic wood grade, and thus might be a good raw material for furniture productions owing to its superior dimensional stability.

• 접착 및 계면
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• 제22권1호
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• pp.22-28
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• 2021

여러 방면에서 사용되는 규조토를 이용한 제품은 수분흡수에 최적화되어 있지만 고경도, 가루날림, 거친 표면 느낌 등의 문제점을 지니고 있다. 이를 개선하기 위하여 경도가 낮고 탄성이 우수한 EVA (Ethylene vinyl acetate)를 이용하여 과량의 무기물을 첨가하여 수분 흡수 특성이 우수하면서도 저경도, 고탄성을 지니는 올레핀계 발포체를 제조하였다. 발포체의 수분 흡수 특성을 부여하기 위해 규조토를 첨가하였으며, 수분 흡수/건조 특성은 규조토의 함유량에 따라 약 10~15%의 수분 흡수율과 10~70%의 수분 건조율을 나타내었다. 본 연구를 통해 규조토가 첨가된 수분흡수형 올레핀계 발포체 제조가 가능하였으며, 발포체에 첨가된 규조토는 그 미세구조와 특징으로 인해 수분 흡수와 발산에 큰 영향을 끼친다는 것이 확인되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권2호
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• pp.296-302
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• 2010

If the fiber reinforced plastic is exposed to the moisture for a long period of time, most of moisture absorption occurs on the resin place, thus dropping cohesiveness between the molecules as the water molecules permeated between high molecular chains grant high molecular mobility and flexibility. Also as the micro crack occurs due to the permeation of moisture on the interface of glass fiber and epoxy resin, it is developed to the overall damage of interface place. Hence, the study on absorption is essential as the mechanical and physical properties of fiber reinforced composites are reduced. However, the study on absorption has the inconvenience needing to expose composite materials to fresh water or seawater for 1 month or up to 1 year. Therefore, this study has exposed fiber reinforced composites to fresh water and has developed a model with an accuracy of 98% after comparing the analysis value obtained by using ANSYS while basing on the experimental value of property decline by absorption and the basic properties of glass fiber and epoxy resin used in the experiment.

• 한국의류학회지
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• 제24권5호
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• pp.686-695
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• 2000

Recently, with a growing interest of health and environment, chitosan which was good in no harmful effect to human body and environment, has been watched as the finish treatment of hygiene and pleasantness. The purpose of this study is to develop multifunctional fabric that was improved antimicrobial activity and deodorization rate, water absorption, static voltage and dye absorption by treatment of nylon 6 grafted with acrylic acid added in chitosan. FT-IR spectra of the grafted with acrylic acid added in chitosan shows peaks of COOH and NH2. Antimicrobial activity and deodorization rate of chitosan and grafted with acrylic acid added in chitosan were increased greatly than the control, durability of laundry of grafted with acrylic acid added in chitosan was good. In case of chitosan was dyed acid dyes and grafted with acrylic acid added in chitosan was dyed basic dyes, dye absorption of them were increased than the control. Moisture regain, absorption time and tensile strength of grafted with acrylic acid added in chitosan was increased greatly than the control.

• Journal of Biosystems Engineering
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• 제31권5호
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• pp.389-394
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• 2006

The characteristic of moisture absorption of granular fertilizer was measured at several different opening sizes on the top cover of a hopper in a humid weather. The size of the opening was to represent the degree of looseness of sealing of the top cover of the hopper. The application distribution was characterized by the scattering distance of granular fertilizer with different degree of moisture absorption in a pneumatic granular fertilizer applicator. The moisture absorption rates were 12.92 and 12.26 mg of moisture an hour for one gram of each granular fertilizers of NPK 22-12-12 and 21-17-17, respectively. The moisture absorption increased linearly as the opening size increased. The median value of the scattering distance distribution decreased with time of absorption, however, it decreased very slowly after three hours of absorption.

• 한국전기전자재료학회논문지
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• 제26권9호
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• pp.656-661
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• 2013

In this study, the moisture content, charge discharge current, electrostatic capacity and dielectric loss tangent are measured for the specimen of bisphenol type epoxy resin which is mixed with squared amorphous silica filler and dipped in hot water of $50^{\circ}C$ for 169 days. The results of this study are listed below. The longer of deposition day, the charge and discharge current was increased. It is considered that the reason is because there was water attack through the squared silica surface. The longer of deposition day, the absorption rate of all specimens was increased. It found that the absorption rate reached saturated state after 100 days. The higher frequency and the longer of deposition day, the $tan{\delta}$ was decreased. Also, It found that the $tan{\delta}$ and electrostatic capacity of the specimen which is mixed with squared filler are greater.

• Journal of the Korean Wood Science and Technology
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• 제44권3호
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• pp.424-429
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• 2016

본 연구에서는 중밀도섬유판, 파티클보드, 배향성스트랜드보드, 합판을 이용하여 탄화보드를 제조하고 각각의 흡방습 특성을 살펴보았다. 탄화보드는 $600^{\circ}C$에서 2시간 동안 열분해하는 조건으로 제조되었다. 그 결과, 탄화합판, 탄화OSB, 탄화MDF, 탄화파티클보드 순으로 높은 흡방습 성능을 나타내었다. 흡습률 및 방습률은 탄화파티클보드를 제외한 나머지 탄화보드들 간에 큰 차이는 발견하지 못했다. 이것은 목질재료가 탄화됨으로서 탄소로 변환되어 수분을 흡착하는데 높은 능력을 가졌지만 수분이 내부구조로까지의 이동에 있어서는 목재 본래의 구조에 영향을 받는다는 것을 의미한다. 따라서 목재의 구조의 특성을 살려 탄소화 했을 때 높은 흡방습 특성을 가진 탄화보드를 제조할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.994-996
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• 1999

Hygrothermal aging at the elevated temperature induces the long-term degradation of the epoxy resin. We investigated the effects of hydrothermal stress on the dielectric breakdown phenomena of epoxy composite filled with natural zeolite. The cured specimens absorbed the moisture in the autoclave at $120^{\circ}C$. $T_g$ of the deteriorated composite by moisture absorption decreased. The dielectric breakdown strength decreased with the moisture absorption cycle. It was concluded that the thermal stress and the high water-vapour-pressure deteriorated the natural zeolite filled epoxy resin system, consequently and the tree growth rate increased.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.892-901
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• 2018

Because of excellent electrical properties, epoxy resin is widely used in packaging and casting power equipment. Moisture and temperature in the environment are inclined to seriously affect the insulation tolerance of epoxy resin. This work focuses on the aging characteristics of epoxy resin in hygrothermal environment. Scanning electron microscopy images show that there are micro-crack, micro-slit and holes inside aged samples. The moisture absorption process undergoes three equilibrium stages and it does not follow the Fick's second law. Observing the change of hydrogen bonds in the infrared spectra of the dried samples, it is found that chemically moisture absorption immerges when the physical moisture absorption entered the third equilibrium stage. By Debye equation to fit the imaginary part of the dielectric constant, it is concluded that the uniformity of water molecule has a great influence on the electrical conductivity loss. Furthermore, the polarization loss can be more easily affected by water molecules than small free molecules. After the aged samples being dried, their real and imaginary part of the dielectric constant descend, but their original electrical properties cannot completely restored. After chemical moisture absorption appears inside the material, the residual space charges increase significantly and the charge dissipation rate slow down obviously.

• 한국의류산업학회지
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• 제23권6호
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• pp.836-843
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• 2021

Recently, with an increase of interest in hygiene of textile products, research related to finishing technology to impart various functionalities, such as antibacterial and deodorizing properties, has also required. Therefore, in this study, the improvement of comfort was examined by analyzing the change of moisture characteristics and antibacterial and deodorizing properties of underwear fabric by chitosan microcapsule(CH-M) finishing. The results revealed that moisture absorption time of the fabric shortened, diffusion rate increased, while absorption rate slightly increased because of microcapsule finishing. In addition, the one-way transfer capacity of the microcapsule finished fabric was 17.69, which improved moisture transfer to one side, while OMMC showed the values of 0.32 and 0.37 for untreated and finished fabrics, respectively, which slightly increased after finishing. In the case of untreated fabric, antibacterial activity was 89.0% against Staphylococcus aureus and 70.3% against Klebsiella pneumoniae; however, both strains showed 99.9% antibacterial activity by CH-M finishing. An excellent bacterial reduction rate was also observed. In the case of the CH-M finished fabric, there was a deodorization effect exceeding 99% up to 120 minutes, and it showed an excellent deodorization effect of more than 99% even after 10 repeated washings.