Interfacial Characteristics of Epoxy Composites Filled with γ-APS Treated Natural Zeolite

이재영,이상근,김상욱,Lee, Jae-Young,Lee, Sang-Keun,Kim, Sang-Wook 한국접착및계면학회 2001 접착 및 계면 Vol.2 No.3

${\gamma}$-APS (${\gamma}$-aminopropyltriethoxysilane)로 표면처리된 천연제올라이트와 에폭시 수지 복합 재료의 표면 자유 에너지, 인상강도 및 계면 모폴로지에 대해 연구하였다. 표면처리하지 천연제올라이트의 표면 자유에너지 성분 중에서 무극성 성분인 Lifshitz-van der Waals 성분, ${\gamma}{\frac{LW}{SV}}$는 $19.22mJ/m^2$이었고, 극성 성분인 Lewis acid-base 성분, ${\gamma}{\frac{AB}{SV}}$는 $15.27mJ/m^2$이 있다. ${\gamma}$-APS의 처리농도가 증가함에 따라 ${\gamma}{\frac{LW}{SV}}$값은 증가하였지만 ${\gamma}{\frac{AB}{SV}}$는 감소하였으며, 이는 ${\gamma}$-APS의 소수성 성분인 알킬기의 영향이 친수성 기인 아민이나 수산기의 영향보다 커지기 때문이다. 인장강도와 Young율은 ${\gamma}$-APS 처리에 의해 개선되었으며, SEM 분석에 의해 계면특성이 향상되었음을 확인하였다. Epoxy composites filled with natural zeolite was prepared to investigate the effects of silane coupling agent, ${\gamma}$-APS (${\gamma}$-aminopropyltriethoxysilane)on the surface free energy, tensile properties and interfacial morphology. The value of Lifshitz-van der Waals component, ${\gamma}{\frac{LW}{SV}}$ for polar was $19.22mJ/m^2$ and increased, while that of Lewis acid-base component, ${\gamma}{\frac{AB}{SV}}$ for polar was $15.27mJ/m^2$ and decreased with the increasing content of ${\gamma}$-APS treatment. It is due that the surface of the zeolite is more coated by hydrophobic of alkyl group than hydrophilic amine or hydroxyl group. The tensile strength and Young's modulus of epoxy system were improved by the treatment with ${\gamma}$-APS due to the strong interface bonding, which was confirmed by SEM.

PET/CT 감쇠보정시 다양한 CT Kernel 적용에 따른 유용성 평가

이재영,성용준,윤석환,박찬록,이홍재,노경운,Lee, Jae-Young,Seong, Yong-Jun,Yoon, Seok-Hwan,Park, Chan-Rok,Lee, Hong-Jae,Noh, Kyung-Wun 대한핵의학기술학회 2017 핵의학 기술 Vol.21 No.2

PET/CT 영상 재구성시 감쇠보정맵을 사용하여 영상재구성에 적용한다. 감쇠보정 맵의 CT parameter을 변경하여 PET/CT 영상 재구성 할 때 적용하여 SUVmax에 어떤 영향을 미치는지 비교 평가해보고자 한다. 장비는 Biograph mCT 64를 사용하였고 Phantom은 NEMA IEC Body Phantom을 사용하였다. 실험을 위해 환자는 2017년 2월에서 3월까지 본원 PET/CT 검사를 시행한 환자 20명을 대상으로 Lung, Liver, Bone에 관심영역을 선택하여 기존 08f AC, 45f medium, 80f ultra sharp 방식의 CT kernel을 적용한 감쇠보정맵을 사용하여 PET/CT 영상 재구성에 도입 후 방사능 농도(kBq/mL), SUVmax, SD(standard deviation) 변화 유무를 평가하였다. Phantom 방사능 농도 측정 결과 B08f AC 대비 B45f 0.96%, B80f 6.58% 증가하였고 B08f AC 대비 B45f 0.86%, B80f 6.54%각각 증가하였고, SD의 경우 B08f AC 대비 B45f 1.27%, B80f 6.96% 증가하였다. 환자에서 부위별 SUV는 Lung에서 B08f AC 대비 B45f 1.6%, B80f 6.6%, Liver에서 B08f AC 대비 B45f 0.7%, B80f 4.7%, Bone에서 B08f AC 대비 B45f 1.3%, B80f 6.2% 증가를 보였다. 부위별 SD는 Lung에서 B08f AC 대비 B45f 6.2%, B80f 15.4%, Liver에서 B08f AC 대비 B45f 2.1%, B80f 11%, Bone에서 B08f AC 대비 B45f 를 사용할 때 2.3%, B80f 14.7% 증가를 보였다. CT Kernel변화에 따라 sharpness noise와 영상의 질은 변화를 보였으나 SUVmax와 SD는 통계적으로 유의한 차이가 없었다.(P>.05). 핵의학 영상은 정량적인 평가가 중요하다 따라서 부위에 따라 CT kernel이 적절하게 조절되고 noise level이 낮은 감쇠보정 맵을 사용하여 PET/CT 재구성시에 적용하여 정량적 평가에 오류를 줄이는 것이 중요하다고 사료되므로 따라서 같은 부위라 할지라도 sharpness noise가 인위적으로 증가된 kernel을 사용하는 것보다 noise가 낮은 kernel을 사용하는 것이 SD편차를 줄이고 정량적인 평가에 오류를 적게 하여 정확한 진단과 SUV 측정에 유용할 것으로 사료된다. Purpose Recently PET/CT image's attenuation correction is used CTAC(Computed Tomgraphy Attenuation Correction). it can quantitative evaluation by SUV(Standard Uptake Value). This study's purpose is to evaluate SUV and to find proper CT kernel using CTAC with applied various CT kernel to PET/CT construction. Materials and Methods Biograph mCT 64 was used for the equipment. We were performed on 20 patients who had examed at our hospital from february through March 2017. Using NEMA IEC Body Phantom, The data was reconstructed PET/CT images with CTAC appiled various CT kernel. ANOVA was used to evaluated the significant difference in the result. Results The result of measuring the radioactivity concentration of Phantom was B45F 96% and B80F 6.58% against B08F CT kernel, each respectively. the SUVmax increased to B45F 0.86% and B80F 6.54% against B08F CT kernel, In case of patient's parts data, the Lung SUVmax increased to B45F 1.6% and B80F 6.6%, Liver SUVmax increased to B45F 0.7% and B80F 4.7%, and Bone SUVmax increased to B45F 1.3% and B80F 6.2%, respectively. As for parts of patient's about Standard Deviation(SD), the Lung SD increased to B45F 4.2% and B80F 15.4%, Liver SD increased to B45F 2.1% and B80F 11%, and Bone SD increased to B45F 2.3% and B80F 14.7%, respectively. There was no significant difference discovered in three CT kernel (P >.05). Conclusion When using increased noise CT kernel for PET/CT reconstruction, It tends to change both SUVmax and SD in ROI(region of interest), Due to the increase the CT kernel number, Sharp noise increased in ROI. so SUVmax and SD were highly measured, but there was no statistically significant difference. Therefore Using CT kernel of low variation of SD occur less variation of SUV.

DGEBA - MDA - SN - Hydroxyl Group System 의 합성 및 복합재료 제조 : 2 . 섬유강화 복합재료의 파괴에너지

이재영,심미자,김상욱 ( Jae Young Lee,Mi Ja Shim,Sang Wook Kim ) 한국공업화학회 1994 공업화학 Vol.5 No.4

유리섬유/탄소섬유/에폭시 수지 hybrid 복합재료의 파괴에너지를 파괴메카니즘 측면에서 연구하였다. 에폭시 수지 매트릭스는 DGEBA(diglycidyl ether of bisphenol A)-MDA(4,4`-methylene dianiline)-SN(succinonitrile)-HQ(hydroquinone)를 사용하였다. 섬유강화 복합재료의 파괴에너지를 연구한 결과, 유리섬유와 매트릭스의 계면에서는 post debond friction energy가 가장 크게 나타났으며, debonding energy와 pull-out energy는 비슷한 값을 나타내었다. 탄소섬유와 매트릭스의 계면에서 파괴가 일어나는 경우에는 pull-out energy가 가장 큰 영향을 나타내었다. The fracture energy of glass fiber/carbon fiber/epoxy resin hybrid composite system was investigated in the aspect of fracture mechanism. Epoxy resin matrix was DGEBA-MDA-SN-HQ system. On the interface of glass fiber and matrix, post debond friction energy provided a major contribution to the fracture energy, and debonding energy and pull-out energy were of the similar value. In the case of fracture on the interface of carbon fiber and matrix, pull-out energy was the major contributor.

홍수기 다기능보 운영을 고려한 수리학적 모형 개발

이재영,김기영,신동훈,Lee,Jae Young,Kim,Ki Young,Shin,Dong Hoon 한국방재학회 2014 한국방재학회논문집 Vol.14 No.3

홍수기 다기능보 운영에 따른 수리학적 영향을 검토하기 위해 내부경계조건 처리 및 세굴심 예측을 개선한 수리학적 모형을 개발하였다. 관측수위나 수위-유량관계곡선 설정을 통한 내부경계조건을 채택하고 있는 기존 범용모형에 비해 조절구조물 상하류의 다양한 계산수위 조건을 고려하여 고정보의 월류량과 가동보의 방류량을 계산할 수 있도록 하였으며 하류부 구조물에 미치는 영향을 분석하고자 하상재료의 토양특성치를 반영한 부정류 상태의 시간별 단기세굴심 변화를 예측하였다. 모형의 적용성을 검증하기 위해 기왕의 홍수사상을 적용하여 다기능보 운영에 따른 보 상하류 주요지점의 홍수위 변화와 다기능보의 방류량을 모의한 결과, 관측치를 잘 재현하고 있음을 확인하였다. 다기능보의 다양한 운영조건에 대하여 모의한 결과, 가동보에 의한 수위상승 효과와 고정보에 의한 세굴심 상승효과가 나타났다. 이를 통해 홍수기 가동보의 운영룰에 따라 상하류 홍수위 상승과 하류부 세굴심 발생을 최소화시키는 것이 가능함을 알 수 있었다. An advanced hydraulic model was developed by improving the numerical implementation of internal boundary condition and the prediction of scour depth to analyse hydraulic effects in operation of multi-function weir during the flooding season. The proposed model calculates overflow at fixed weir and gate discharge controlled by movable weir depending on the computed water stages on the upstream and downstream reach compared to conventional model applying internal boundary condition specified as prescribed stage or rating curve. In addition, it can predict time-dependent scour depth considering soil properties under unsteady state in order to investigate the hydraulic effects on bridge structure located downstream. A historical flood event was applied to demonstrate the verification of the model as simulation results were compared with observations on monitoring station. It was shown that the prediction of water stages, gate discharges, and scour depth enable gate operation rule to minimize the effect of flood stage rising by movable weir and scour depth development by fixed weir.

ADHD 학생의 동네환경과 특별활동의 경험에 대한 비교연구

이재영,최범성,강동묵,김지훈,Lee, Jae-Young,Choi, Bum-Sung,Kang, Dong-mug,Kim, Ji-Hoon 대한생물정신의학회 2018 생물정신의학 Vol.25 No.3

Objectives The purpose of this study is to investigate the differences between a attention deficit hyperactivity disorder (ADHD) group and a general student group in terms of the perception of the residential environment and periodic activities outside the classroom. Methods The patient group consisted of 62 outpatients or inpatients at the Department of Pediatric Psychiatry, and 49 patients diagnosed with ADHD were selected. For the control group, 3727 youths in elementary schools, middle schools, and high schools of one city were asked to fill out questionnaires. Of the 1717 respondents who responded to the questionnaires, 245 were selected for a patient-controlled study. The differences between the patient group and the control group were compared using the chi-squared test (${\chi}^2$ test). Results There was a significant difference between the patient group and the control group in areas where students responded by "My neighborhood is dirty and littered (p < 0.05)". There was also a significant difference between the patient group and the control group in terms of having more than one club activity per month (p < 0.05). Conclusions It was found that the patients with ADHD are more aware of perceived negative aspects of the area in which they reside, thus reflecting their anxiety. In addition, it was also found that the patient group did not partake in as many social activities as the control group.

Electrodeposition of a Single Phase Cu2O Film by Current Pulsed Methods

이재영,남종우,탁용석,엄성현,강진욱 ( Jae Young Lee,Sung Hyun Um,Jin Wook Kang,Chong Woo Nam,Yong Sug Tak ) 한국공업화학회 1997 한국공업화학회 연구논문 초록집 Vol.1990 No.3

국내 부지 특성을 고려한 오염토양 정화기술매칭기준안

이재영,이민희,유목련,Lee, Jae-young,Lee, Minhee,Yu, Mokryun 한국지하수토양환경학회 2016 지하수토양환경 Vol.21 No.6

The programmable logic array to match the treatment technology to the soil contaminated site based on the site properties in Korea was developed. Based on the previous technology screening system of FRTR (Federal Remediation Technology Roundtable) in USA, total 9 evaluation factors indicating the site characteristics were used for the technology matching process and 8 factors among them were quantitatively weighed in the order of importance. The class interval for each evaluation factor was linearly distributed to give the weighed score and 8 scores were summed up to prioritize the treatment technology. The optimal treatment technology for a specific site was determined according to the total score acquired from 8 evaluation factors used in this technology matching process. The reliability test for the developed technology matching system was done by using information of two real cleanup sites in Korea, suggesting that this guideline will be available to determine the most effective treatment technology to cleanup the soil contaminated site and also to assist the government or the company to design a successful and cost-effective site cleanup plan in Korea.

QCA 를 이용한 CO2 의 전기화학적 환원에 따른 구리전극의 특성 연구

이재영,탁용석 ( Jae Young Lee,Yong Sug Tak ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

Kissinger Equation 과 Fractional Life 법에 의한 DGEBA / MDA / MN 계와 DGEBA / MDA / MN / HQ 계의 경화반응 속도론

이재영,심미자,김상욱 ( Jae Young Lee,Mi Ja Shim,Sang Wook Kim ) 한국공업화학회 1994 공업화학 Vol.5 No.4

DGEBA/MDA/MN계와 이 계에 촉매로서 hydroquinone(HQ)를 첨가한 계의 경화반응 속도론을 Fractional life법 및 Kissinger equation에 의해 연구함으로써 HQ가 경화반응 속도에 미치는 영향을 연구하였다. 경화반응 온도가 증가함에 따라 반응속도는 증가하였고, 반응차수는 약간의 변화가 있을 뿐 경화온도에 따른 경향성은 없었다. 촉매로 HQ를 첨가한 계가 첨가하지 않은 계보다 반응속도는 크게 증가하였고, 활성화 에너지는 13% 감소하였다. 이는 HQ의 히드록 시기가 에폭사이드기, 아민기와 반응하여 전이상태를 형성함으로써 에폭사이드 고리를 쉽고 빠르게 개환시켜 주기 때문이다. Cure kinetics of DGEBA/MDA/MN system with and without HQ were studied by Fractional life method and Kissinger equation. And the effect of HQ as a catalyst was studied As cure temperature increased, the reaction rate increased and reaction order was almost constant. The activation energy of the system with HQ was lower about 13% and the reaction rate was higher than that of the system without HQ. It was because hydroxyl group of HQ formed a transition state with epoxide group and amine group and opened the epoxide ring easily and rapidly.

유한요소해석을 이용한 알루미나 정전척의 글라스 기판 흡착 특성 연구

이재영,장경민,민동균,강재규,성기현,김혜동,Lee, Jae Young,Jang, Kyung Min,Min, Dong Kyun,Kang, Jae Gyu,Sung, Gi Hyun,Kim, Hye Dong 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.4

In this research, the attractive force of Coulomb type electrostatic chuck(ESC), which consisted of alumina dielectric, on glass substrate was studied by using the finite element analysis. The attractive force is caused by the high electrical resistance which occurs in contact region between glass substrate and dielectric layer. This research tries the simple geometrical modeling of ESC and glass substrate with air gap. The influences of the applied voltage, and air gap are investigated. When alumina dielectric with 1014 Ω·cm, 1.5 kV voltage, and 0.01 mm air gap were applied, electrostatic force in this work reached to 4 gf/㎠. This results show that the modeling of air gap is essential to derive the attractive force of the ESC.