불소화 에틸렌 프로필렌 나노 입자 분산액을 이용한 3차원 다층 미세유체 채널 제작

민경익 ( Kyoung-ik Min ) 한국화학공학회 2021 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.59 No.4

In this study, fluorinated ethylene propylene (FEP) nanoparticle as an adhesive for fabricating a threedimensional multilayered microfluidic device was studied. The formation of evenly distributed FEP nanoparticles layer with 3 μm in thickness on substrates was achieved by simple spin coating of FEP dispersion solution at 1500 rpm for 30 s. It is confirmed that FEP nanoparticles transformed into a hydrophobic thin film after thermal treatment at 300 ℃ for 1 hour, and fabricated polyimide film-based microfluidic device using FEP nanoparticle was endured pressure up to 2250 psi. Finally, a three-dimensional multilayered microfluidic device composed of 16 microreactors, which are difficult to fabricate with conventional photolithography, was successfully realized by simple one-step alignment of FEP coated nine polyimide films. The developed three-dimensional multilayered microfluidic device has the potential to be a powerful tool such as high-throughput screening, mass production, parallelization, and large-scale microfluidic integration for various applications in chemistry and biology.

타이로신이 풍부한 펩타이드를 사용한 금 나노입자의 손쉬운 합성과 4-니트로페놀의 촉매 환원 응용

허윤미 ( Yun-mi Hur ),민경익 ( Kyoung-ik Min ) 한국공업화학회 2021 공업화학 Vol.32 No.1

본 연구에서는 타이로신이 풍부한 펩타이드, Tyr-Tyr-Gly-Tyr-Tyr (YYGYY)를 환원제 및 안정화제로 사용하여 구형의 금 나노 입자의 간단한 합성 방법을 연구하였다. 펩타이드로 둘러싸인 구형의 다결정 금 나노 입자는 UV 조사 하에서 펩타이드 및 금속 전구체의 농도를 조절하여 3~15 nm 크기로 합성되었다. 합성된 금 나노 입자의 특성을 확인하기 위하여 투과 전자 현미경(TEM), 자외선-가시광선 분광광도계(UV-Vis spectroscopy), 주사 투과 전자 현미경 및 에너지 분산 X선 분광법(STEM-EDS), 푸리에 변환 적외선 분광법(FT-IR), X선 회절 분석법(XRD)을 사용하여 분석하였다. 또한, 합성된 금 나노입자는 4-니트로페놀의 환원 반응을 통해 7.3 × 10^-3 s^-1의 반응속도 상수를 갖는 촉매 활성을 확인하였다. In this study, we studied a facile method for the synthesis of stable and nearly spherical gold nanoparticles using a tyrosine- rich peptide, Tyr-Tyr-Gly-Tyr-Tyr (YYGYY), as both the reducing and capping agent. The peptide coated spherical and polycrystalline gold nanoparticles with diameters from 3 to 15 nm were successfully synthesized by varying the concentration of the peptide and metal precursor under UV irradiation. The nanoparticles were then characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Furthermore, the catalytic activity of gold nanoparticles was confirmed by the reduction of 4-nitrophenol to 4-aminophenol, in which the catalytic reaction rate constant was 7.3 × 10^-3 s^-1.

MICE산업 종사자의 워라벨이 조직몰입과 자아존중감(self-esteem)에 미치는 영향

황유경 ( Hwang Yu-kyoung ),민경익 ( Min Kyung Ik ),김철원 ( Kim Chulwon ) (사)한국마이스관광학회 2021 MICE관광연구 Vol.21 No.4

This study aims to study the effects of work-life balance on organizational commitment and self-esteem by improving workers' quality of life and satisfaction in the MICE industry. The study revealed that work-family balance positively affects organizational commitment in the three elements of work-family balance, work-leisure balance, and work-growth balance in the MICE industry. As a result of hypothesis testing, the study identified that only the work-family balance among the three work-leisure balance factors significantly affected organizational commitment and had a positive (+) effect on self-esteem through organizational commitment. Based on the results of the research, implications for increasing the quality of life for MICE industry workers, securing and maintaining the professional workforce, and bringing positive changes to the MICE industry through a balanced development of work and life were discussed.

제주지역 외국인 국제회의 참가자 수요예측에 따른 음식업의 경제적 파급효과 분석

오정학 ( Jeong Hak Oh ),민경익 ( Kyoung Ik Min ) (사)한국마이스관광학회(구 한국컨벤션학회) 2010 MICE관광연구 Vol.10 No.2

The number of international conference holding in Korea is rapidly increased. From 2000 to 2008, the number of holding international meeting is increased 292 to 634, 217%, also foreign participants are increased. As a result, Government and local governments are giving their best efforts to encourage it. For this reason, the effects to local economy by holding international meeting and participants demanding forecast are essentially needed for efficiency of building infrastructures and preparing holding international visitors. This point of view, this study aim to predict expenditure of participants and find out effects towards food service industry based on 2011 international visitors in Jeju. For demanding forecast, KTO annual report of 2000 to 2008 Jeju area the number of international meeting foreign participants is used. Using this data, this study analyzed through the second regression model. Also it analyzed Production, Income, Employment, Added value, Multiplier effects of indirect tax based on 2007 Bank of Korea regional input-output table. The result of demanding forecast shows that 2011 Jeju area will have 29,000 international comers for participating international meetings and through this, This study predict food service industry would gain 8,459 millions sales profit. The result of the regional I-O model indicate that food service industry would generate 10,968 million Won of output impact, 2,036 million Won of income impact, 5,599 million Won of value-added impact, 1,138 million Won of tax, and 287 full-time jobs throughout direct and in direct effects.

다이타이로신 공유결합으로 자기조립된 펩타이드 나노입자의 합성

허윤미 ( Yun-mi Hur ),민경익 ( Kyoung-ik Min ) 한국화학공학회 2021 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.59 No.1

In this study, a method of self-assembly of peptides based on irreversible covalent bonds was studied by mimicking a biological covalent bond, dityrosine bond. A tyrosine-rich short peptide monomer having the sequence of Tyr-Tyr-Leu-Tyr-Tyr (YYLYY) was selected to achieve a high-density of dityrosine bond. The peptide nanoparticles covalently self-assembled with dityrosine bonds were synthesized by one-step photo-crosslinking of a peptide using a ruthenium catalyst under visible light. The effect of the concentration of each component for the size of the peptide nanoparticle was studied using dynamic light scattering, UV-Vis spectroscopy, and transmission electron microscopy. As a result, the synthesis conditions for size of the peptide nanoparticles ranging from 130 nm to 350 nm were optimized.

금-펩타이드 하이브리드 나노입자의 제조와 메틸렌 블루의 촉매 환원 응용

허윤미 ( Yun-mi Hur ),민경익 ( Kyoung-ik Min ) 한국공업화학회 2021 공업화학 Vol.32 No.2

본 연구에서는 타이로신이 풍부한 펩타이드, Tyr-Tyr-Leu-Tyr-Tyr (YYLYY)를 이용하여 금 나노입자를 담지한 균일한금-펩타이드 계층적 초분자 구조체의 합성에 대해 연구하였다. 펩타이드의 광가교 반응을 통해 다이타이로신 결합으로 자기조립된 펩타이드 나노입자를 합성하였고, 타이로신의 생체 광물화 특성을 이용하여 금-펩타이드 하이브리드 나노입자를 친환경적 방법으로 합성하였다. 합성된 금-펩타이드 하이브리드 나노입자는 투과 전자 현미경(TEM), 주사투과 전자 현미경(SEM), 동적 광산란(DLS), 자외선-가시광선 분광광도계(UV-Vis spectroscopy), 에너지 분산 X선 분광법(STEM-EDS), X선 회절 분석법(XRD)을 통해 분석하였다. 또한 합성된 금-펩타이드 하이브리드 나노입자는 메틸렌블루의 환원 반응에서 13.4 × 10^-3 s^-1의 반응속도 상수를 가지는 촉매 특성을 확인하였다. In the present work, we studied a method for the synthesis of uniform gold-peptide hierarchical superstructures using tyrosine rich peptide, Tyr-Tyr-Leu-Tyr-Tyr (YYLYY). Peptide nanoparticles self-assembled by dityrosine bonds were synthesized through the photo-crosslinking reaction of the peptide, and gold-peptide hybrid nanoparticles were synthesized using biomineralization properties of tyrosine in a green synthetic manner. The synthesized gold-peptide hybrid nanoparticles were then characterized by transmission electron microscopy, scanning electron microscopy, dynamic light scattering, UV-vis spectroscopy, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy, and X-ray diffraction. Furthermore, the catalytic activity of gold-peptide hybrid nanoparticles was confirmed by the reduction reaction of methylene blue where the catalytic reaction rate constant was 13.4 × 10^-3 s^-1.