• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.269-272
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• 2002

UV curing technology becomes important in various sectors of applications due to the high efficiency, environmental protection, and saving of energy. The effect of different proportion of vinylester (VE) and unsaturated polyester (UP) for VE/UP blend system was investigated in context of mechanical properties. The compositions of VE/UP blend were varied within 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0 by weight percent. 1 wt% 1-hydroxy-cyclohexyl-phenyl-ketone was used as photoinitiator. The used intensity of UV light was in the range of $40~70 mW/\textrm{cm}^2$. The flexural strength of vinylester was not sensitive to the intensity of UV light. But the unsaturated polyester was very sensitive to the intensity of UV light. The flexural strength of vinylester was always superior to that of unsaturated polyester. The addition of the vinylester increased the flexural strength of blend system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1773-1777
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• 2010

The Application of UV curing technique for poly (vinyl chloride) (PVC) floor tiles coating has improved the quality of PVC floor. Several formulations were made including acrylated oligomers based on a polyurethane were blended with reactive monomers, photoinitiators and other additives. The used oligomers are commercial aliphatic urethane acrylates. Thin films were prepared on PVC tiles by bar coating with different formulations using UV radiation. The coating resins were characterized by FTIR. The properties of UV-cured films such as gloss and adhesion were examined. The properties of UV-cured films dependent on the influence of composition and processing conditions was studied.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.168-170
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• 2005

The myeolchi-jeot samples were divided into different groups with or without the supplementation with biogenic amines. Subsequently, the samples were placed in an oven at $80^{\circ}C$ for 1 hr to allow the chemical reaction to proceed, and then were analyzed for N-nitrosamine contents using GC-TEA. N-nitrosamine was not detected in any of the myeolchi-jeot samples which had been treated with/without sodium nitrite. On the other hand, the yield of N-nitrosopyrrolidine from 1,000 mg/kg of putrescine and spermidine in the myeolchi-jeot samples (treated with 5 mg/kg of sodium nitrite) was 0.002 and 0.014%, respectively. N-nitrosamine was not produced from any other biogenic amines like, histamine, tyramine, cadaverine and spermine. In addition, curing and heating were the factors which influenced the formation of N-nitrosamine during the nitrosation of biogenic polyamines. For the formation of N-nitrosamine in the food systems, treatment with sodium nitrite and heating at appropriate temperature along with the satisfied supplementation of biogenic polyamines are required.

• Journal of Adhesion and Interface
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• v.4 no.3
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• pp.14-20
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• 2003

In order to study the radiation curing behavior of poly(ethylene glycol 400) dimethacrylate and ethylene glycol dimethacrylate, we investigated the influence of temperature and photoinitiator concentration by photo-DSC. As the number of ethylene glycol unit, the concentration of photoinitiator, and the reaction temperature increased, the reaction speed of PEG400DMA and EGDMA increased. Although the reaction speed of PEG400DMA was lower than EGDMA, the overall conversion of PEG400DMA was high.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.19-25
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• 2006

Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.187-195
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• 2023

A shield was made by mixing materials such as bismuth(Bi) and barium(Ba) with silicon to evaluate its shielding ability. Bismuth was made into a shield by mixing a bismuth oxide(Bi₂O₃) colloidal solution and a silicon base and applied to a fibrous fabric, and barium was made by mixing lead oxide(PbO) and barium sulfate(BaSO₄) with a silicon curing agent and solidifying it to make a shield. The test was conducted according to the lead equivalent test method for X-ray protective products of the Korean Industrial Standard. The experiment was conducted by increasing the shielding body one by one from the test condition of 60 kVp, 200 mA, 0.1sec and 100 kVp, 200 mA, 0.1 sec. At 60 kVp, 2 lead oxide-barium sulfate shields, 2 bismuth oxide 1.5 mm shields, and 5 bismuth oxide 0.3 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. At 100 kVp, 2 lead oxide-barium sulfate shields and 2 bismuth oxide 1.5 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. It was confirmed that when using 2 pieces of lead oxide-barium sulfate and 1.5 mm of bismuth oxide, respectively, it has shielding ability equivalent to that of lead. Bismuth oxide and lead oxide-barium sulfate are lightweight and have excellent shielding ability, thus they have excellent properties to be used as an apron for radiation protection or other shielding materials.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.80-83
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• 2009

Application of UV curing technique for poly vinyl chloride (PVC) floor tiles coating has improved the quality of PVC floor. Various formulations including acrylated oligomers based on a polyurethane were blended with reactive monomers, photoinitiators and other additives. The used oligomers are commercial aliphatic urethane acrylates. Thin films were prepared on PVC tiles by bar coating with different formulations using UV radiation. The coating resins were characterized by FTIR. The properties of UV-cured films such as gloss grade and adhesion were examined. The properties of UV-cured films dependent on the influence of composition and processing conditions was studied. The investigation was conducted to achieve an optimal domain of composition and desired coating effect.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.975-986
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• 2013

This paper dealt with the fabrication and performance evaluation of the electronics housing made of lightweight composite materials, aiming at the enhancement of satellite mass savings by replacing conventional aluminum alloy widely used for satellite avionics with lightweight composite material. For this purpose, a fabrication process was designed to overcome low machinability of CFRP and to minimize the post-treatment. The composite housing with grid-stiffened and monolithic frame was made using co-curing method. Its performance was also evaluated regarding endurance, stiffness, thermal conductivity, electrical grounding, EMI protection and radiation shielding. The composite housing can provide the considerable mass savings over the aluminum housing with same dimension.

• Polymer(Korea)
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• v.39 no.2
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• pp.281-286
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• 2015

UV-cured acrylic copolymer pressure sensitive adhesive (PSA) having different amounts of crosslinking agents were prepared and adhesion properties were investigated. 0.01 wt% of MMT clay was dispersed in 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) monomer mixture containing 0, 0.05, 0.1 and 0.3 wt% 1,6-hexandiol diacrylate (HDDA) for crosslinking. It was investigated that the curing behavior and surface chemistry of PSAs were merely affected by the presence of MMT clays. On the other hand, adhesive properties were influenced by the MMT addition; a cohesive failure was restrained due to improved molecular elasticity even in uncrosslinked acrylic PSAs. However, it was also appeared that combination of 0.3 wt% crosslinking agent and MMT loading might result in the damage of adhesion properties of PSAs possibly due to the lack of chain flexibility. In our studies, it is suggested that the 2-EHA/AA PSAs incorporating 0.01 wt% of MMT and crosslinked with 0.05 wt% of HDDA exhibited the balanced adhesion properties without severe cohesive failure during strip.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.133-140
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• 2005

Purpose : This test is designed to identify the validity of treatment plan by implementing real-time dosimetry by means of dose that is absorbed into PTV and OAR when preparing doses of 3D and POP plans. Materials and Methods : In treatment. error can be calculated be comparing Exp. Dose with the actual dose, which has been converted from 'the reading value obtained by placing diode detector on the area to be measured'. Same test can be repeated using Alderson-Rando phantom. Results : Errors were found: A patient(POP plan): 197.6/199=-1.2%, B patient(3D-plan): 199.9/198.7=+0.6%, C patient: 196/200=-1.5%. In addition, considering the resulted value of measuring OAR besides target-dose for C patient showed 96/200, representing does of 47%, the purpose of protection was judged to be duly accomplished. Also it was acknowledged the resulted value of -3.7% met the targeted dose within the range of ${\pm}5%$. Conclusion : Aimed for identifying the usefulness of pre-treatment dose measurement using diode detector, this test was useful to evaluate the validity of curing because it resulted in the identification of category to be protected as well as t dose. Moreover, it is thought to have great advantage in ascertaining the dose of target, dose of which is not calculated yet. Similar to L-gram before treatment, this test is thought to be very effective so that it can bring great advantages in the aspects such as validity of curing method and post-treatment plan as well.