• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.12a
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• pp.111-113
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• 2004

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.15-22
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• 1997

This experiment was performed to examine the immuno-reactive characteristics of fish metal-binding protein, metallothionein (MT), and gain the practical understandings for the proposed use of fish MT as a biomarker. Liver MT induced by Cd in the silver carp was seperated and purified by gel filtration chromatography and ion exchange chromatography. The immuno-reactivity of fish MT was examined with 3 rabbit antisera. Fish MT showed little reactivity with rabbit anti-rat MT antiserum and a weak reactivity with anti-MT peptide antiserum while showed a strong reactivity with rabbit anti-fish MT antiserum. The time-course change of liver MT in the silver carp, after waterborne exposure to 1 ppm of Cd, was checked by Cd-hem method and established competitive ELISA. In both cases, the induction of liver MT showed a good increasing relationship with the exposure days. The results indicate that the fish MT can be developed as a useful biomonitoring means in the toxicological study and for the evaluation of water pollution.

• Elastomers and Composites
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• v.55 no.1
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• pp.20-25
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• 2020

The effect of the isocyanate index (NCO index) on the particle size and particle size distribution of a waterborne polyurethane dispersion (WPUD) with polycarbonate-diol was determined. The WPUDs were prepared using a conventional acetone process with polycarbonate-polyol (M_n = 2028), 4,4'-methylenebis(cyclohexyl isocyanate) (H₁₂MDI), 2,2-bis(hydroxymethyl) propionic acid (DMPA), and dibutyltin dilaurate catalyst. At NCO index values below 1.5, the number average particle diameter of the WPUDs significantly increased with the NCO index, whereas the particle diameter slightly varied at higher NCO indexes. The dependency of the WPUD viscosity on the NCO index exhibited similar behavior to that of the particle size. The relative values of the full width at half maximum of the WPUD particle distribution curves at various NCO indexes were not influenced by the NCO index.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.778-786
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• 2017

In this study, analyzed the changes occurred after adding casein emulsions to water - dispersed polyurethane using polypropylene glycol (PPG). For this purpose, anionic water - dispersed polyurethane containing PPG, IPDI and DMPA and casein emulsion prepared by dissolving casein in distilled water using ammonia water were prepared. As a result of measuring the alkali resistance by using the prepared resin, there was no change in the physical properties. The tensile strength of the sample having a high casein content was measured to be $2.227kgf/mm^2$. Elongation was measured at 474% for samples containing less casein and The abrasion resistance was measured as 46.090 mg.loss of sample containing much casein as a result of the surface roughness measurement.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.246-256
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• 2018

Graphene oxide (GO) reinforced Polyvinyl chloride (PVC)-Waterborne Castor Alkyd (WCA) nanocomposites (PVC/WCA/GO) films were processed through solution blending technique. TGA showed that the thermal stability of PVC/WCA/GO-0.5 films was better than that of PVC/WCA blend film. With incorporation of 0.5 wt.% GO, the tensile strength and elastic modulus of the blend nanocomposite have significantly improved by about 260% and 185%, respectively, compared with neat polymer. The physicomechanical properties of these films suggest that the PVC/WCA/GO nanocomposite films may have a potential scope for their application in packaging industries. The results are supported by characterizations like FTIR, XRD, TEM and FESEM.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.162-163
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• 2021

To prepare the waterborne silicone acrylic resin coatings, acrylic resin was prepared by a radical polymerization. Glass transition temperature(Tg) of the acrylic copolymer was fixed at 30℃ and the contents of tertiary amine monomer(DMAEMA), were varied to be 5, 10, 15 and 20 wt%, hydroxyl monomer, and carboxyl monomer were fixed 10 wt%, and 4 wt% respectively. γ-Glycidoxypropyltrimethoxysilane(GPTMS) containing epoxy group was used for curing agents. The eqivalent ratio of amine to epoxy was 1:1. The prepared coatings exhibited excellent adhesion to various substrates, and various physical properties of the coatings were satisfactory. The gloss retension and color difference were improved at low tertiary amine concentration. The coatings containing 10wt% tertiary amine concentration have especially good weather resistant properties.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• Journal of fish pathology
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• v.26 no.2
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• pp.89-97
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• 2013

The study was carried out to investigate the changes of hematological parameters induced by waterborne exposure of chromium (Cr) in the mullet, Mugil cephalus. The mullet was exposed to sub-chronic concentrations of chromium (0, 25, 50, 100, $200{\mu}g/L$ Cr) for 4 weeks. The major hematological findings were significant decreases in the red blood cell (RBC) count and hematocrit value in mullet exposed to ${\geq}50{\mu}g/L$ Cr. Although serum calcium concentration was significantly reduced at ${\geq}50{\mu}g/L$ Cr, magnesium concentration was found to be significantly increased at ${\geq}100{\mu}g/L$ Cr. The serum glucose and total protein concentrations were significantly increased at $200{\mu}g/L$ Cr. However, serum triglyceride concentration did not show any noticeable changes in the range of $25{\sim}200{\mu}g/L$ Cr of chromium compared to control group during the experimental period. A significant increment of GOT (glutamic oxalate transminase) and GPT (glutamic pyruvate transminase) activities was noticed at ${\geq}100{\mu}g/L$ Cr. These results indicate that hematological and serum biochemical changes in the mullet by waterborne exposure to chromium are affected at more than $50{\mu}g/L$ Cr.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.122-130
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• 2004

Crude oil is complex mixture of thousands of different organic compound formed from a variety of organic materials that are chemically converted under differing geological conditions over long periods of time. Also oil composition varies according to crude source, refining, processing, handling and storage. The oil fingerprint method is application of specific knowledge of petrochemicals and use of sophisticated analytical equipment and techniques to identify the source(s) of oil pollution. KNMPA currently utilizes three primary analytical techniques: Gas Chromatography (GC), Fluorescence Spectroscopy(FL) and Infrared Spectroscopy(IR). Of all these techniques, GC technique are most widely used. Gas Chromatography is used as a primary analytical method because high reliableness, high separating efficiency and repeatability, but it is timeconsumable. The study results of identification of waterborne spilled oil by Fast Gas Chromatograph method showed that analytical time is cut down to 30minutes in comparison with packed column method and chromatograms represent high resolution and high repeatability.

• Journal of Life Science
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• v.21 no.6
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• pp.819-828
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• 2011

To inspect norovirus contamination of groundwater in south eastern areas of Korea, a systematic survey of groundwater in Busan, Ulsan, and Gyeongsangnam-do was performed for two years from 2009 to 2010. For this purpose, we first optimized the nested reverse transcription-PCR condition by designing two sets of primers for the detection of norovirus genogroups, GI and GII. Of 145 samples, 21 (25.9%) and 15 (23.4%) were norovirus positive in the dry season (April to June) and wet season (July to August), respectively. The detection frequencies of norovirus in Busan, Ulsan, and Gyeongsangnam-do were 15%, 7%, and 32%, respectively, reflecting a geographical difference in their distribution. The GI and GII isolates were 5 and 31, respectively, indicating the prevalence of GII in the tested areas. According to phylogenetic analysis of their nucleotide sequences, all of the GI isolates were identified to genotype GI.5 whilst the GII isolates were divided into two genotypes, GII.3 and GII.4. Neither physical-chemical parameters such as pH, temperature, oxidation-reduction potential, and dissolved oxygen, nor microbial indicators of water quality such as total bacteria, total coliforms, and Escherichia coli were statistically correlated with contamination of norovirus in the groundwater. Interestingly, however, the presence of norovirus was closely correlated with low turbidity (<0.50 NTU). The present study suggests that periodical monitoring of norovirus in groundwater is necessary to prevent epidemic waterborne diseases and to secure better sanitary conditions for public health.