• Fibers and Polymers
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• v.7 no.3
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• pp.235-240
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• 2006

Polyacrylonitrile (PAN) fiber was grafted with casein after alkaline hydrolysis and chlorination reactions of the original fiber. The structures and morphologies of the casein grafted fiber were characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscope (SEM). Moisture absorption, specific electric resistance, water retention value, and mechanical properties were also investigated. The results showed that casein was grafted onto the surface of the PAN fiber and the grafted PAN fiber presented better hygroscopicity compared with the untreated fiber. With proper tensile strength, the modified fiber could still meet the requirement for wearing. A mechanism was proposed to explain the deposit of casein on the synthetic acrylic fiber.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.187-192
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• 1981

In order to increase the dissolution rate on the mixture of sulfamethoxazole and trimethoprim (SMX-TMP), their coprecipitates with polyvinylpyrrolidone (PVP) were studied. Coprecipitates prepared with various ratios of SMX and TMP were examined such as hygroscopicity, apparent solubility, apparent partition coefficient and the dissolution behavior of SMX-TMP's coprecipitates and their physical mixtures. The hygroscopicity of coprecipitates were less than that of physical mixtures. The apparent solubility and dissolution rate of SMX-TMP's coprecipitates were found to be greatly increased. The dissolution rates of SMX and TMP in the coprecipitates were decreased when the ratio of two ingredients to PVP was smaller, and the dissolution rate of SMX was increased when the ratio of SMX to TMP was larger.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1344-1350
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• 2016

The purpose of this study was to evaluate the effect of edible coating on hygroscopicity and quality characteristics of a freeze-dried Actinidia arguta snack. Freeze-dried A. arguta snacks were coated with various edible coating materials such as albumin, dextrin, and whole soy flour. There were no significant effects of coating on major quality properties such as moisture content, water activity, yield, water soluble index, water absorption index, and rehydration properties of all samples. Compared with non-coated samples, edible coated samples effectively inhibited hygroscopicity as a function of hygroscopic time. The samples coated with dextrin showed lower hygroscopicity than the other coated samples. In addition, the effects of edible coating treatment on hardness, total phenolic content, and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity were investigated. Edible coated samples had higher hardness, total phenolic content, and antioxidant activity than the non-coated samples as a function of hygroscopic time. Among edible coating materials, dextrin was the most effective coating material. Dextrin as an edible coating material for freeze-dried A. arguta snack may help to prevent hygroscopicity and extend market quality and shelf-life during storage.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.226-227
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.10a
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• pp.227-228
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.256-257
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• 2008

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.28-42
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• 2017

Moisture transfer characteristics of high emotional garments are important to evaluate wear comfort. Wicking and drying measurement methods are also critical for perspiration absorption and quick dry fabric made of high functional fibers. In this study, the wicking and drying properties of high emotional fabrics made from hybrid composite yarns using CoolMax, Tencel, Bamboo staple fibers and PP. PET CoolMax filaments were also measured and analyzed according to various measuring methods. The wicking property of hybrid composite yarn fabrics by Bireck method was mostly influenced by the structure of hybrid yarns than the absorption rate of constituent fibers; however, both the hygroscopicity of fibers and the composite yarn structure affected the wicking property of the fabrics in the drop method. Concerning drying properties, the KSK 0815B method measuring distilled moisture weight was more relevant to explain the drying characteristics of hybrid yarn fabrics than the KSK 0815A method measuring the time to drying. This study revealed that the drying properties of hybrid yarn fabrics were influenced by the hygroscopicity of constituent fibers, wicking properties of constituent yarns and structure of composite yarns.

• Asian Journal of Atmospheric Environment
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• v.4 no.1
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• pp.55-61
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• 2010

The sensitivity of aerosol light extinction coefficient to the aerosol chemical composition change is estimated by (1) calculating the aerosol water content and chemical concentrations by a gas/particle equilibrium model and (2) calculating the aerosol light extinction coefficient by a Mie theory based optical model. The major chemical species are total (gas and particle phase) sulfuric acid, total nitric acid, and total ammonia which are based on the measurement data at Seoul and Gosan. At Seoul, since there were enough ammonia to neutralize both total sulfuric acid and total nitric acid, the dry ionic concentration is most sensitive to the variation of the total nitric acid level, while the total mass concentration (ionic concentration plus water content) and thus, the aerosol light extinction coefficient are primarily determined by the total sulfuric acid. At Gosan, since the concentration of ambient sulfuric acid was the highest among the inorganic species, sulfate salts determined aerosol hygroscopicity. Thus, both ionic and total mass concentration, and resultant aerosol light extinction coefficient are primarily determined by the sulfuric acid level.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.61-66
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• 1997

Paulownia wood has been used as sound board for Korean traditional musical instruments such as Keomungo(Korean lute), Kayagum(twelve-stringed Korean harp) and Changgu(hour-glass shaped drum), etc. The acoustic properties of wood affected not only by dimensions but also by density and stiffness of wood. Due to inhomogeneity and hygroscopicity of wood. the acoustic properties of wood are inconsistent. To clarify the effect of moisture content and air dry density on acoustic properties, longitudinal vibration experiment was accomplished in 3 moisture content levels of 9.6, 11.1 and 12.5% and in 3 air dry density levels of 0.22, 0.25 and 0.28g/$cm^3$. The results were as follows: As the moisture content increased, the fundamental frequency. specific dynamic Young's modulus and sound velocity decreased, but the internal friction increased so that loss of energy increased. The values in damping of sound radiation were rapidly decreased at 12.5%. It meant that the damping of internal friction was larger than damping of sound radiation at high moisture content. As the air dry density increased, the fundamental frequency, specific dynamic Young's modulus and sound velocity increased, but the internal friction and damping of sound radiation decreased so that loss of energy decreased. And acoustic converting efficiency was hardly influenced by increasing air drying density.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.793-798
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• 2007

During May of 2003, smoke from fires in the Yucatan Peninsula was transported across the Gulf of Mexico and into Texas where it caused significant enhancement in measured aerosol concentrations and reduced visibility. During this event, the formation and growth of aerosol particles has been observed by a differential mobility analyzer (DMA) / tandem differential mobility analyzer (TDMA) system to characterize the size distribution and size-resolved hygroscopicity of the aerosol. The most number concentration is by the particles smaller than 100 nm, but the integrated number concentrations for over 100 nm increased due to the aerosol growth. Hygroscopic growth factor increase from 1.2 to 1.4 for 25, 50, and 100 nm particles during the nucleating period. This distribution and the aerosol properties derived from the TDMA data were used to calculate the growth rate. Particle growth rates were in the range 1-12 nm/hr.