• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.15-19
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• 1995

This study was made of the effects from exposure to air temperature and amount of solar radiation during the wilting period on the sunburn of burley tobacco. Tobacco stalks were cult with one hour interval from 8:00 to 16:00, and were left on the field to expose to weather, and tobacco single leaf placed under 4 temperatures regimes in indoor. Sun-burn of the leaves was occurred when the leaves were exposed to temperature higher than 33$^{\circ}C$, and to solar radiation more than 800w/$m^2$ between 11:00-15:00 in a day during the curing season. The leaf temperature was increased until 52$^{\circ}C$ under the weather condition. The tobacco leaves were also burned without solar radiation when the leaves were exposed to high temperature until 5$0^{\circ}C$ of leaf temperature. Sun-bum was increased at upper leaves and at higher moisture content of leaf.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2613-2619
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• 2020

This work investigated the gamma-ray shielding performance, and the physical and mechanical properties of poly (methyl methacrylate) (PMMA) composites embedded with 0-44.0 wt% bismuth trioxide (Bi₂O₃) fabricated by the fast ultraviolet (UV) curing method. The results showed that the addition of Bi₂O₃ had significantly improved the gamma shielding ability of PMMA composites. Mass attenuation coefficient and half-value layer were examined using five gamma sources (Cs-137, Ba-133, Cd-109, Co-57, and Co-60). The high loading of Bi₂O₃ in the PMMA samples improved the micro-hardness to nearly seven times that of the pure PMMA. With these enhancements, it was demonstrated that PMMA/Bi₂O₃ composites are promising gamma shielding materials. Furthermore, the fast UV curing exerts its great potential in significantly shortening the production cycle of shielding material to enable rapid manufacturing.

• Polymer(Korea)
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• v.39 no.2
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• pp.256-260
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• 2015

The addition of montmorillonite (MMT) in the UV curable polyurethane diacrylate based resins was investigated to fabricate nanocomposites with improved mechanical properties and water sorption behavior using different photoinitiator systems. As a result, it was observed that 1 wt% of clay loading fairly improved tensile resistance and water uptake behavior. It can be also confirmed that dual photoinitiator system consisted of benzyldimethyl ketal and bisacyl phosphine oxide exhibited enhanced energy absorption band 340~450 nm even with 3 wt% of MMT concentration, which may affect the curing behavior of nanocomposite especially in our UV lamp system.

• Journal of Fashion Business
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• v.11 no.6
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• pp.52-61
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• 2007

To increase the ultraviolet radiation (UVR) protection of cotton fabric, ultraviolet protection (UVP) materials were treated onto cotton fabric using a new technique, UV-curing. A photocrosslinkablepolymer, poly(ethylene glycol) dimethacrylate was used as a UV-curable resin in the presence of a small amount of photoinitiator. Two kinds of UVP materials were used, UV-absorber, 2,2'-dihydroxy-4-methoxy benzophenone, and UV-scatterer, $TiO_2/ZnO$ Pad-dry-cure method in employing these materials onto cotton was also conducted to compare the effectiveness and the washfastness of UVP treatment between curing methods. UVP treated cotton fabric showed a moderate increase in UVP in case of 2,2'-dihydroxy-4-methoxy benzophenone treatment and a high increase in case of $TiO_2/ZnO$. UV-curing method increased the washfastness of UVP property of $TiO_2/ZnO$ treated cotton fabrics. However, in case of 2,2'-dihydroxy-4-methoxy benzophenone, similar wash fastnesses of UV-cured and pad-dry-cured cotton were observed. It can be presumed that 2,2'-dihydroxy-4-methoxy benzophenone was not significantly affected by water since its hydrophobicity. In short, UV-curing of UVP materials onto cotton was successfully done, and treated cotton fabrics showed the increased UVP properties and an increased washfastness in some extent.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.159-173
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• 2012

UV-Curing technology can be classified into two categories for radical curing and cation curing. It also has mainly focused on surface finishing technology to improve functionality of various substrates such as plastics and metals. On the other hand, EB technology has dealt with cross-linking reactions as well as polymerization process to create novel functional materials. Both technologies have advantages in energy utilizing efficiency and environmental friendly when compared to conventional thermoset coatings. Consequently, UV cured coatings also permits a reduction in the $CO_2$ and VOCs emitted in the drying and curing process. This review mainly shows radical curing technology which is commonly used in UV curing coatings and also describes the technology trends of cation curing which has been attracted attention recently.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.726-729
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• 2000

The entitled report revealed that ZnO phosphor samples treated at different temperatures under a given reduction atmosphere show the radiation brightness increase with increase of temperature up to about 900$^{\circ}C$ but become decreasing beyond the temperature. The brightness deterioration with curing temperature at higher temperatures was explained by the decrease of excess zinc ions resulted from their evaporation. The comments will open possibility for different discussions on the experimental result by introducing numerical relationships between the concentration of the native defects and the curing condition.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.1
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• pp.39-52
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• 2004

A novel evaluation method is investigated for measuring the ability of acid amplification of acid amplifier. The method is based on the measurement of conductivity change by the acid generation according to UV radiation. It is found that the decrease of conductivity is caused by photopolymerization of epoxy monomer during UV curing process of ink film and the by the rate of UV curing. In this paper, the novel acid amplifiers were synthesized and measured thermal stability by means of DSC. It was found that mono-type acid amplifiers were more stable than di-type. It is possible to make the dynamical evaluation the curing rate of UV curable ink in curing process by this method.

• Nuclear Engineering and Technology
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• v.5 no.1
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• pp.3-12
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• 1973

Some physical and chemical properties of wood-plastic combinations(W.P.C.) made of domestic soft woods such as pinus densiflora, pinus rigida and poplus deltoides were measured. The rates of improvement in properties were roughly proportional to the contents of polymer or polymer mixtures in W.P.C. For the W.P.C. obtained by means radiation curing and containing 80% of polymer or polymer mixture, the hardness and water absorptirity were improved 2.2 times and 4 times those of the original wood, respectively. The improvement of hardness was especially remarkable in the W.P.C. made of pinus densiflora and polystyrene(120%) to show 7 times increased hardness. For the W.P.C. obtained by means of thermal curing and containing 80% of polymer or polymer mixture, the hardness and water absorptivity were improved 2.4 times and 3.4 times those of the non-treated woods, respectively. These data indicate that the properties of W.P.C. prepared by means of radiation curing are not much different from those of W. p. C. prepared by means of thermal curing. Both of acid resistancy and alkali resistancy of the W.P.C. were also improved remarkably in comparison with the non-treated wood.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6464-6471
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• 2014

The UV curing method is a popular process for lens molding on a unit wafer. This process, however, has several drawbacks including wafer adhesion during the ejection process after curing, errors in lens shape and wafer warpage due to material shrinkage during the curing process, and lens centering errors on both sides of a wafer. Among these, the lens shape error and warpage are influenced directly by the UV curing process due to factors including the UV radiation uniformity, the degree of cure according to UV intensity, and the shrinkage characteristics of the material. Therefore, a theory is needed not only to understand the change in the material characteristics, such as the shrinkage rate due to the curing reaction, but also to establish a model. In addition, an analysis system is needed to realize the model. This study proposes a new analysis method for the wafer lens molding process by Comsol modeling. This method was verified by comparing the results with those of the actual process.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.15-16
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• 2009

Poly(vinyl alcohol) was crosslinked by UV irradiation in the presence of water soluble photoinitiators. The crosslinking of PVA films with 1,2,3,4-Butanetetracarboxylic acid(BTCA) and sodium phosphinate monohydrate(SPM) was also achieved via thermal curing. Different factors in the crosslinking including thermal and radiation methods were studied. Gel fraction of PVA films increased with increasing photoinitiator concentration. The maximum gel fraction on the crosslinking method was reached about 81%. The glass transition and maximum decomposition temperature improved by both thermal and radiation crosslinking.