• Journal of the Korean Applied Science and Technology
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• v.21 no.3
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• pp.197-203
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• 2004

Acrylic resins ($HSC_s$ : EA/EMA/2-HEMA/CLA) which contain 70% solid content were synthesized by the copolymerization of monomers (2-hydroxyethyl methacrylate, ethyl acrylate, and ethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows : viscosity 245${\sim}$515 cps ; $M_n$ 2670${\sim}$2840 ; and conversions, 83${\sim}$91%, respectively. From the correlation of $T_g$ values, viscosities, and $M_n$ of the HSCs, it was found that viscosity and $M_n$ increased with $T_g$ value.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.818-822
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• 2008

The purpose of this study is to develop realistic painting simulation in real-time as well as to represent the thickness of the deposited paint on the surface. The Gaussian model is used for a painting deposition model to calculate the thickness of paints. For a painting simulation, rather than implementing particle systems, we propose a new heuristic algorithm for painting process based on a few number of rays. After we find the collision points of the rays with an environment, we compute the painted area using flood-fill searching method on the texture map and visualize paint effects. We analyzed time complexity of our method to verify that our system is suitable for real-time VR applications.

• Safety and Health at Work
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• v.4 no.4
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• pp.216-220
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• 2013

A 46-year-old man who had worked as a bumper spray painter in an automobile body shop for 15 years developed lung cancer. The patient was a nonsmoker with no family history of lung cancer. To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during spray painting, sanding, and heat treatment. The results showed that spray painting with yellow paint increased the concentration of hexavalent chromium in the air to as much as $118.33{\mu}g/m^3$. Analysis of the paint bulk materials showed that hexavalent chromium was mostly found in the form of lead chromate. Interestingly, strontium chromate was also detected, and the concentration of strontium chromate increased in line with the brightness of the yellow color. Some paints contained about 1% crystalline silica in the form of quartz.

• Journal of ILASS-Korea
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• v.8 no.1
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• pp.16-22
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• 2003

Zeta potential measurements of colloid particles suspended in a liquid are performed by a Zeta Meter developed. There are many applications of colloid stability in spray technology, paints, wastewater treatment, and pharmaceuticalse. Zeta potentials of charged particles are obtained by measuring the electrophoretic velocities of the particles using video enhanced microscopy and image analysis program. The values of zeta potential of polystyrene latex(PSL), $silica(SiO_2)$M, polyvinylidence difluoride(PVDF), silicon nitride, and alumina particles in deionized (DI) water were measured to be -40.5, -31.9, -25.2, -15.1 and -10.1mV, respectively. The particles having high zeta potential less than -20 mV are stable in DI water, because the double layers of them have strong repulsive forces mutually, and the particles having low zeta potential over -20mV are unstable due to Van Der Waals forces. Silica(>20nm), PSL, aluminum and PVDF particles were found to be stable that would remain separate and well disperse, while silicon nitride and alumina particles were found to be unstable that would gradually agglomerate in DI water.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.1037-1044
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• 2007

Metallic paint is one of the most widely used coating in automotive, cosmetic and other applications because of its well-known ability to give a product realistic look which creates widespread consumer appeal. But, this coating has complicated subsurface structure which includes pigments, flakes, and transparent clearcoat. Though various analytic reflection models are available to simulate appearance of various surfaces, it is difficult to select an appropriate reflection model with faithful parameters for simulating this coating due to the complex subsurface structure of metallic paints. This paper presents a framework for accurate modeling of metallic coating by determining an appropriate reflection model among various existing BRDF (Bidirectional Reflectance Distribution Function) models. The selection of the appropriate model is achieved by measuring BRDF of various metallic paint samples using a BRDF measuring device i.e. gonioreflectometer and fitting an existing model to the measured data. Then, this model is effectively realized by rendering metallic painted surfaces. We believe that this framework can serve as a guide for those who wants to render metallic painted surfaces accurately with analytic BRDF model without expending time on extracting BRDF data using gonioreflectometer from real metallic paint sample.

• Journal of Environmental Science International
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• v.20 no.2
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• pp.163-174
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• 2011

Butyltin compounds in seawater, sediments and organisms inside Jeju Harbor of Jeju Island, Korea, were quantitatively determined to assess the extent of contamination and to evaluate the bioaccumulation in Thais clavigera (gastropod), Liolophura japonica and Cellana nigrolineata. In addition, imposex in T. clavigera was used to assess the sublethal effect of tributyltin compounds and its usage as a specific biomarker for these compounds was also studied. The main species in seawater was tributyltin (TBT) in March and June, monobutyltin (MBT) in August, but in sediments and organisms it was dibutyltin (DBT) and TBT, respectively, irrespective of survey time. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serous effect on the sensitive organisms upon chronic exposure. The high correlations (r>0.7) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints and their sources were negligible. The sedimentary organic matters have little influence on the distribution of BTs in marine environment and the lipid content in T. clavigera showed a significant correlation with TBT concentrations. Measurement of imposex T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of those.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.97-105
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• 2009

Seed storage lipids of plants, essential for seed germination as energy supplier, have been used for humankind and animal as nutrition sources. Fatty acids of vegetable oils have the characters appropriate for industry based on their chain length, the position and the number of double bonds. So they are used as raw materials for lubricants, cosmetics, soaps, paints and plastics or as energy source such as bio-diesel. However, there is a limit that applies vegetable oils from typical oil crops for industrial uses, mainly because of the mixture of five common fatty acids. Therefore, identification of unusual fatty acids for industrial uses from diverse plant resources and metabolic engineering to produce unusual fatty acids have been carried out in Arabidopsis as a model for the study of oilseed biology. Here, we discuss the unusual fatty acids for industrial uses, the genes synthesizing them in lipid metabolism, and the current limits in production of transgenic plants accumulating unusual fatty acid in their seeds. In addition, we describe our work on metabolic engineering of Brassica napus for the production of the unusual fatty acid ricinoleic acid in the seed, because of its industrial uses.

• Journal of the korean society of oceanography
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• v.37 no.2
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• pp.82-89
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• 2002

Butyltins (BTs) were measured in 2 species of shellfish and 16 species of fish collected along the Korean coast. Tributyltin (TBT) was detected in the mussels and oysters of sentinel organisms (20 to 940 ng Sn/g dry wt), indicating widespread contamination of TBT in the Korean coast. The elevated concentrations of TBT in the shellfish found in the sites near harbors or shipyards suggested that antifouling paints are probable major sources of butyltins in these areas. The TBT compound was detected in 12 out of 16 fish samples. The concentrations of TBT in fish muscles wee between 7 and 151 ng Sn/g dry wt, while the level in whole body of anchovy was very high (793 ng Sn/g dry wt). Exposure doses to Korean people via consumption of these marine products wee evaluated. The results suggested that the environmental levels of TBT were below the level of concern.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.517-523
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• 2006

The sustainable development is a key issue in the whole field of economy, culture and society, which can be accomplished by the improvement of environment. Recently, life cycle assessment(LCA) has been applied to reduce environmental impacts preliminarily by evaluating the environmental performance of a product through its life cycle. In this study, life cycle assessment was performed to analyze quantitatively the environmental impact on the interior panel of electric motor unit(EMU). As a result, the interior panel with aluminum showed the most global warming(GW), while that with phenol and plastic showed high fresh water aquatic ecotoxicity(FAET) and marine water aquatic ecotoxicity(MAET), respectively. Global warming was occurred mainly due to the emission of $CO_2$ by energy consumption. FAET and MAET were caused by the pollutants released from acid-washing and paints coating process. Therefore, an environmental-friendly EMU can be designed considering the environmental impacts of interior panel.

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.335-344
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• 2011

The pearlesent pigment has received attention in a diversity of fields like cosmetics, inks, paints and so on. Ferric Ferrocyanide, one of the nano sized pearlescent pigment, is a kind of surface modification pigment that covers a metal oxidized substance or a coloring agent with uniform thickness. Characteristics of pearlescent pigment are various interference color, intense gloss effect and a three-dimensional effect. We synthesised the pearlesent pigment that ferric ferrocyanide can be deposited on the titania/mica surface by hydrothermal synthesis method. The process parameters are concentration of precursor, controlling pH and reaction temperature. The optimun conditions is that amount of iron(III) chloride hexahydrate is 3.1 wt% and amount of potassim ferrocynide trihydrate is 3.6 wt% in the started pH 4.5 at $70^{\circ}C$. The coating rate and coating efficiency of ferric ferrocyanide was about 1.47 % and 96.7 %, respectively. The synthesised pearlesent pigment was characterized by SEM, XRD, FT-IR and EDS.