• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.95-95
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• 2018

강재의 방식법 중 도장은 부식을 억제하는데 효과적이고 편리한 방법으로 선박 및 해양 강 구조물의 방식법으로 사용되고 있다. 한편, 강 구조물의 효율적인 유지관리를 위해서는 방식 도장의 도막 열화도를 평가하고 잔존 수명을 예측하여 최적 시기에 보수도장 혹은 재도장하는 것이 필요하다. 일반적으로 선박 및 해양구조물에 적용되는 도막의 방식 성능 평가 방법으로 해수 침지 시험, 염수 분무 시험, 옥외 폭로 시험 등이 있다. 그러나 이러한 시험들은 그 시험 방법에 따라서 정량적인 평가에 한계가 있음은 물론 장기간 소요되는 등 곤란한 문제점이 있다. 그러므로 선박 및 해양구조물을 비롯하여 교량, 각종 강 구조물의 도장 방식에 사용되는 방식용 도료의 성능을 단기간에 적절하게 평가할 수 있는 가속시험법이 제시되며 연구-사용되고 있다. 그 중 도막 방식 성능을 보다 효율적, 비파괴적, 정량적으로 평가할 수 있는 임피던스 분광법(EIS)과 같은 전기화학적 방법은 상대적으로 시험 기간을 크게 단축시킬 수 있고, 대상 방식 도장의 미세한 성능 차이도 분별 가능하다는 장점이 있다[1]. 따라서 본 연구에서는 선박 및 해양구조물 등 가혹한 부식환경에서 강력한 내구성을 가질 수 있도록 다양한 종류의 표면처리 도장 시편을 제작하여 자외선 조사-염수분무-침지환경 등의 열악한 환경조건 하에서 부식-열화 촉진 시험을 실시하였다. 그리고 그 촉진 열화 과정에서 도막의 외관 상태를 관찰 분석함은 물론 전기화학적 임피던스 분광법을 병행 측정하며 그 표면막의 부식 및 도막 열화도를 비교-종합 평가하였다.본 연구에 사용된 시편은 Al 및 Zn 도금 강판에 에폭시, 에폭시-실리콘 우레탄, 에폭시-우레탄 도장 시편으로 Scribe, No Scribe 및 비교재 Al 및 Zn 도금 시편으로 분류하여 각각 실험을 진행하였다. 즉, 도막 열화 시험은 복합 노화 시험법으로 UV 조사 36 시간(ASTM G53), 염수분무 32 시간(ISO 7253), 수분 응축 10 시간을 1 Cycle로 100 Cycle(7800 시간) 동안 실험을 진행하였다. 이때 도막 열화도 평가는 전기화학적 임피던스 분광법을 이용하여 각 실험 조건별로 주파수에 따른 임피던스(Z) 값을 평가하였다. 즉, 상온 $25^{\circ}C$의 3.5% NaCl 100 ml 수용액에 작동 전극(Working Electrode)과 구리 도선을 통해 연결하였고, 노출 면적은 $1cm^2$로 일정하게 유지 하였으며, 상대 전극(Counter Electrode)은 탄소봉, 기준 전극(Reference Electrode)으로 포화카로멜전극(Saturated Calomel Electrode)을 사용하여 측정하였다. No Scribe 시편의 경우에는 Al 기판 에폭시-실리콘 우레탄 도장 시편이 우수한 도막 저항성을 나타내었으며, 에폭시-우레탄 도장시편은 23사이클 이후의 저항값이 가장 낮게 나타났다. Zn 기판의 경우는 에폭시, 에폭시-실리콘 우레탄, 에폭시-우레탄 도장 시편 모두 저항 값이 유사하였으며, Al 및 Zn 도금 시편은 도장 처리된 시편에 비해 훨씬 낮은 저항 값을 보였다. 또한 Scribe 시편의 경우에는 Al 기판 에폭시-실리콘 우레탄 도장 시편에서 높은 초기 저항 값을 보였으며, 23 사이클 후의 저항 값은 세 종류의 도막에서 약 1~0.1 Gohm 으로 나타났다. 그리고 Zn 기판 에폭시-실리콘 우레탄 도장 시편에서 가장 낮은 도막 저항 값이 나타났다. 이상의 실험을 통해서 본 연구 내용은 실내촉진시험으로 선박 및 해양 강 구조물에 사용되는 다양한 종류의 도막의 열화도를 평가하는 기초 설계 지침으로 응용될 수 있을 것으로 사료된다. 한편, 도막은 노출 환경에 따라 방식 성능이 다르므로 실제 도막의 사용환경을 고려하여 도장 사양별 적용 부위에 따른 적정 가속 실험 방법을 선정할 필요가 있다고 사료된다.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.1-8
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• 2011

The objective of this paper is to evaluate the performance of low $CO_2$ asphalt binder properties using LEADCAP$^{(R)}$(Low Energy and Carbon Asphalt Pavement) additive as function of various aging methods such as RTFO(Rolling thin film oven), Ultraviolet(UV) lay. In order to simulate the short-term aging of asphalt binder that occurs during the hot-mixing asphalt process, the Rolling Thin Film Oven(RTFO) was used. Asphalt binder using LEADCAP$^{(R)}$ is prepared by addition of a photoinitiator activated by ultraviolet lay. The mechanical and rheological properties of the asphalt binder were estimated using UTM(Universal Testing Machine) and DSR(Dynamic Shear Rheometer). The test results showed that the asphalt binder using LEADCAP$^{(R)}$ additive was improved the rutting resistance at testing temperature ($70^{\circ}C$) and increased tensile strength at low temperature. Also, Thermal analysis shows that the Melting Point(Tm) of asphalt binder using LEADCAP$^{(R)}$ additive was constant although the asphalt binder was aged by Ultraviolet.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.67-72
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• 2014

Minimal broth containing nicotine as a sole carbon source (MB/N) was used to isolate novel nicotine-degrading bacterial strains from tobacco plants and field soils. Comparative analysis of 16S rRNA gene sequence, phenotypic test and morphological tests showed that the position of these isolates were in the genus Arthrobacter of the family Micrococcaceae. The highest 16S rRNA gene sequence similarity of the isolate NU11 and NU15 to type strains in the genus Arthrobacter were Arthrobacter equi (98.2%) which was presumably a novel strain and Arthrobacter nicotinovorans (99.8%), respectively. Both strain NU11 and NU15 showed rod shaped, Gram-positive characteristics and catalase activity, but did not show oxidase activity. The novel strain NU11 was found to degrade efficiently nicotine in MB/N medium by the analysis of UV absorption spectra and could be used as an organism in bioremediation technique.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.969-972
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• 2000

Quality characteristics and functional properties of four kinds of propolis collected from 4 different regions were compared. Ethanol extract of propolis (EEP) showed high absorbance of UV at 208 ~ 212 nm and at 292~294 nm. Total flavonoid contents of 4 propolis were at a range of 16.30~21.87 mg/g However, no significant difference in the flavonoid content was observed among four kinds of sample. All EEP showed the high antimicrobial activities, especially against Salmonella typhimurium. Hydrogen donating activities of the EEP were high appear 65.94 to 78.67% in all samples. The EEP from Sunchon showed the highest activity of hydrogen donation among samples. All extracts had the higher nitrite-scavenging activity than 0.1% BHT. Compared to control, a significant decrease in lipid oxidation was found in all 4 extracts.

• Elastomers and Composites
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• v.44 no.1
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• pp.63-68
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• 2009

Recently, much attention has focused on the permanent deformation of roads in hot summer and cracks in cold winter, which are detrimental to safe driving. This leads to necessity of modification of asphalt to resist those deformation. In this study, a type of modified asphalt was prepared by addition of a photoinitiator which is activated by ultraviolet lay. The mechanical and rheololgical properties of photoinitiator-modified asphalt were examined using UTM and rheometer. Results showed that the modified asphalt was effected by ultraviolet and thus tensile strength and storage modulus increased, due to molecular attraction, with initiator content and irradiation dose. Thermal analysis showed less weight loss upon photoinitiator-modification and this indicated that the molecular attraction is the result of cross linking reaction between asphalt molecules induced by photoinitiator. According to long term ultraviolet curing test, properties of the photoinitiator-modified asphalt did not decrease or even increase for 20 years. This indicates that useful life of the asphalt could be extended by addition of photoinitiator.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.142-149
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• 2010

Development of alternative testing methods for the replacement of hazardous reagents with less hazardous ones is strongly enforced because exposure of human and environment to hazardous reagents are restricted and hazardous reagents are gradually prohibited from using in various testing methods. Thus, in this study, we developed 8 monographs from the Korean Pharmaceutical Codex by substituting the use of the hazardous reagents including ICH class 1 such as benzene, chloroform and dioxane to the use of less toxic ones like ICH class 2 or 3 reagents. We also improved their qualification and quantification performance. Among 8 monographs, the 6 newly developed TLC methods for the identification of nifedipine, oxolamine citrate, ketoprofen lysinate, chlorquinaldol, retinol acetate, and riboflavin showed a clear spot of corresponding material without any interference in spite of the replacement with ICH class 2 or 3 reagents. For the quantification of domperidone and trimebutine, HPLC methods were developed for the substitution of UV/VIS spectrometry and titrimetry, respectively. These HPLC methods were validated for the linearity, recovery, reproducibility, and inter-laboratory variations. In conclusion, the newly developed methods could be expected to become valuable tools for revising the Korean Pharmaceutical Codex.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.339-347
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• 2015

This study is to evaluate moisturizing effect and durability of UV A/B blocking activity with multiple (W/O/W) emulsion system. Most of the sun protective products come to be hot issue having both high SPF and long-lasting activity as using special products when is going out, mountain climbing and sports. Also, many consumers prefer the products which have the excellent waterproofing activity of sun care cosmetics as well as the non-sticky feeling that carried out the study of the sensorial science and texture preference. Therefore, development of the specific formulation using this multiple (W/O/W) emulsion technology, it has O/W type hydro skin feel having soft and moist texture when it is treated on the skin. Finally, this formulation is instantly changed to W/O type feel after adsorbed into the skin. The purpose of this study is to get high SPF lasting effect having high water resistance tactivity with high functional multiple (W/O/W) emulsion cream. We used major ingredients, UV-B absorbers were selected with ethylhexyl methoxycinnamate, isoamyl-p-methoxycinnamate, ethylhexylsalicylate, and octocrylene, UV-A absorbers were selected with butylmethoxydibenzoylmethane, bis-ethylhexyloxyphenol methoxy phenyltriazine. SPF effect of O/W type cream was 34.1. SPF effect of W/O/W type cream was 40.6 (increased about 19%). Water resistance effect after 4 hours, SPF effect of O/W type cream was 3.6 (quickly drop down). SPF effect of W/O/W type cream having 81.0 % waterproofing effect was 32.7 (decreased about SPF 7.9). Moisturizing effect of O/W cream at first was superior comparing multiple emulsion. But after 3 hours quickly was drop-down. Moisturizing effect of multiple emulsion was high comparing O/W type and other sun block creams after 4 hours was constantly maintaining water-content.

• Journal of Life Science
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• v.14 no.1
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• pp.1-7
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• 2004

The root of Stnchys Sieboldif MIQ was extracted three times with methanol and extract was found to contain 3.02% of polyphenols and 1.97% of flavonoids. DPPH radical scavenging method, ferric thiocyanate method, and nitrite scavenging ability method were employed to investigate the constituents of the extract and to measure their activity on antioxidation. The fraction extracted by ethylacetate showed higher anti oxidation value than that of $\alpha-tocopherol$, butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) at the same concentration. UV-VIS spectral data of the extract by ethylacetate that was isolated on a silica gel column proved adsorption maxima in the range of 280∼330 nm. The fraction ES-RS that has $\lambda_{max}(nm)$ of band 1, 325nm and band II, 289nm exhibitd the strongest activity on antioxidation. ES-R5 fraction showed similar pattern to flavones by the analysis of UV-VIS spectral data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.317-327
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• 2013

Air pollution and artificial heat of urban areas have caused the urban heat island in which asphalt pavements absorb solar heat during the daytime and release the heat at night. Hence, in order to improve the environment of urban areas, it is necessary to examine cooling pavements that can reduce heat on road pavements in urban areas. The application of temperature insulation paints on road pavements require to reduce black brightness for visibility, to increase the reflection rate of infrared light and minimize the reflection rate of visible light. In the study, one part of Acrylic-emulsion was used as a main binder, and the changes in black brightness and the changes of addition ratio (0%, 15%, 30%) of hollow ceramics, as well as kinds of paints (carbon black pigment, mixed mineral pigment) were selected as the main experimental factors. The performance of temperature reduction of cooling pavements was analyzed through the reflection rate of spectrum, the reflection rate of solar heat, and the lamp test. Abrasion resistance, UV accelerated weather resistance, and sliding resistance were tested in real situations. In addition, the performance of heat reduction of testing pavements covered with high-reflection paints was analyzed by using an infrared camera. As the test results, when using mixed mineral paints and hollow ceramic of 30%, the reflection rate of spectrum was 43% in the area of near-infrared ray and 17% in the area of visible light at black brightness of $L^*$=42.89 and the reflection rate of solar heat was 27.5%. Total color difference was ${\Delta}E$=0.27 in the test of UV Accelerated Weather Resistance, indicating almost no changes in color. BPN was more than 53 when scattering #2 and #4 silica sand of more than $0.12kg/m^2$. In Taber's abrasion resistance test, abrasion loss was up to 86.4mg at 500 rotations. The performance of heat reduction was evaluated using an infrared camera at the test section applying high-reflection paints to asphalt pavements, in which the results showed that the temperature was reduced by $12.7^{\circ}C$ on CI-30-40 cooling pavements ($L^*$=38.76) and by $14.2^{\circ}C$ on CI-30-60 cooling pavements ($L^*$=57.12).

• Analytical Science and Technology
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• v.11 no.2
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• pp.96-104
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• 1998

A photodiode array multichannel detector system for capillary electrophoresis was developed. The photodiode array detector for capillary electrophoresis (CE-PDA) has 1024 photodetectors and can analyze sample by measuring UV/VIS absorption spectrum in 275~675 nm wavelength range. The CE-PDA instrument can get a spectrum in 30 ms during sample separation and can be programmed by a PC to control various experimental conditions required for sample analysis. The performance of the multichannel CE-PDA instrument was tested using L-ascorbic acid and alizarin yellow GG mixture. The reproducibility test of the CE-PDA system showed 5.6% RSD.