철재형 이안제의 설계외력 산정기법 검증을 위한 실해역 시험

권혁민,권오균,한유식,윤강훈,Kweon. Hyuck Min,Kwon. Oh Kyun,Han. Yu Sik,Yoon. Kang Hun 한국방재학회 2012 한국방재학회논문집 Vol.12 No.1

철재형 이안제는 구조형식이 단조롭고 설계가 용이하며 퇴적파랑을 통과시키는 등 장점이 많아 기존의 중력식 방파제의 대안으로서 기대된다. 철재형 이안제의 설계기법은 권혁민 등(2011), 권오균 등(2011), 이정렬 등(2011)이 보고한 바 있다. 권혁민 등(2011)은 철재형 이안제의 설계외력을 산정함에 있어서 유의파고에 상당하는 규칙파를 사용하고 말뚝의 심도설계를 위한 연직상향력은 수평판의 지점별 최대압력분포로부터 산정할 것을 제안하였다. 본 연구는 제안된 외력산정기법의 실해역 검증을 위하여 수행되었다. 또한 본 연구에서는 설계상 가능한 구조물에 대하여 실해역 실험을 통하여 축조 과정 기술 확보, 파괴 여부 판정, 철거 가능성을 검증하고자 한다. 철재형 이안제에 사용된 소파판은 <TEX>$9m{\times}12m$</TEX>(길이<TEX>${\times}$</TEX>폭)의 크기이고, 강관말뚝은 직경 711 mm, 두께 12 mm, 길이 23.2 m이다. 실해역 실험 결과, 본 구조물의 축조는 기존의 장비로 약 8시간 만에 1셀의 시공이 가능하고, 유의파고 5.83 m의 외력에 대하여 말뚝의 수평 및 수직 상호변위는 매우 작게 발생하였으며, 철거는 양호한 기후조건에서 2일이 소요되었다. 본 실해역 시험을 통하여 권혁민 등(2011)의 철재형 이안제에 작용하는 외력산정기법이 유용하며 말뚝의 인발력에 대한 마찰 안전율이 약 2.0에 상당하다는 것을 알았다. 또한 철재형 이안제는 설계, 시공, 철거가 간단하며, 소파판의 착탈식 운영방식으로 해안의 사정에 따라 모래포집량 조절이 가능할 수 있다는 기대를 높이게 되었다. The steel-type breakwater has the merits of structural simplicity and passing the long period wave for beach accretion. So, it has been expected to be a key tool for the strategic beach protection technology. The design methodology of the steel-type breakwater was published by Kweon et al.(2011), Kwon et al.(2011), Lee et al.(2011). For the analysis of the resistant friction load acting on the pile, Kweon et al. proposed the estimation method of the design up lift force acting on the dual horizontal plate. With a train of regular wave corresponding to the significant one, they integrated the distribution of the biggest pressure at each point. For the verification of the estimation method of the load on the pile, the study is carried out the experiment in a real sea state. Moreover, the construction procedure, the displacement, joint checking and removal possibility of the steel-type breakwater are discussed. The constructed breakwater has the horizontal wave energy dissipator of <TEX>$9m{\times}12m$</TEX>(<TEX>$length{\times}width$</TEX>) and pile diameter of 711 mm, thickness of 12 mm, length of 23.2 m. The construction took about 8 hours for 1 cell composed of 9 piles and 1 horizontal dual plate. There is a little vertical and horizontal displacement of pile attacked by the maximum wave height of 5.83 m. The removal of 1 cell took about 2 days. This study shows the merits of the easier design, faster construction and simpler removal of the steel-type breakwater. The structure could be estimated as a stable one because it has the horizontal dissipator on which acting a little compression and a little uplift force due to the perforated holes. Moreover, the easier removal could make it possible to manage the coastal line as depending on the conditions of erosion or accretion sand volume.

Novel anthracene derivatives carrying coumarin moiety for organic light emitting diodes

권혁민,박종욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

4-Methyl-7-(10-phenyl-anthracen-9-yl)-chromen-2-one (PhAC), 4-Methyl- 7-(10-naphthalen-1-yl-anthracen-9-yl)-chromen-2-one (1-NAC), 4-Methyl- 7-(10-naphthalen-2-yl-anthracen-9-yl)-chromen-2-one (2-NAC), and 7-Anthracen-9-yl-4-methyl-chromen-2-one (AC) were synthesized through Suzuki aryl-aryl coupling reaction. Four compounds were used as emitting layer (EMLs) in non-doped OLEDs with the following structures: ITO/2-TNATA(60 nm)/NPB(15 nm)/EMLs(35 nm)/Alq3(20 nm)/ LiF(1 nm)/Al(200 nm). Non-doped devices showed luminescence efficiency of 2.14, 2.07, 1.52, and 1.12 cd/A at a current density of 10 mA/㎠.

N-Type Indenofluorenedione Field-Effect transistors with high efficiency and stability

권혁민,박종욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

We developed high-performance stable n-type organic field-effect transistors (OFETs) using indenofluorenediones with different numbers of fluorine substituents (MonoFIF-dione, DiF-IF-dione, and TriF-IF-dione). Top-contact OFETs were fabricated via the vacuum deposition of indenofluorenediones as the semiconducting channel material on polystyrenetreated SiO₂/Si substrates. TriF-IF-dione FETs with Au source/ drain contacts exhibited good device performances, with a fieldeffect mobility of 0.16 ㎠/(V s), an on/off current ratio of 106 , and a threshold voltage of 9.2 V. We found that the electrical stability for OFETs based on indenofluorenedione improved with the number of fluorine substituents, which was attributed to higher activation energies for charge trap creation. Moreover, the TriF-IF-dione FETs yielded excellent environmental stability properties, because the LUMO energy levels were relatively low, compared with those of the MonoF-IF-dione FETs.

Novel Thermal Latent Metal Catalyst Using Titanium and Organic Ligand for Urethane Polymerization

권혁민,박종욱 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.1

지오그리드로 보강된 투수성 연성포장 보조기층제 영구변형을 고려한 층두께 산정 비교 연구

권혁민,오정호,한신인 한국도로학회 2015 한국도로학회논문집 Vol.17 No.1

PURPOSES : The objective of this study is to evaluate the effectiveness of a geogrid reinforced subbase of permeable flexible pavement structures with respect to permanent deformation. METHODS : Experimental trials employing a repeated triaxial load test scheme were conducted for both a geogrid reinforced subbase material and a control specimen to obtain the permanent deformation properties based on the VESYS model. Along with this, a finite elementbased numerical analysis was conducted to predict pavement performance with respect to the rutting model incorporated into the analysis. RESULTSAND CONCLUSIONS: The results of the experimental study reveal that the geogrid reinforcement seems to be effective in mitigating permanent deformation of the subbase material. The permanent deformation was mostly achieved in the early stages of loading and then rapidly reached equilibrium as the number of load applications increased. The ultimate permanent deformation due to the geogrid reinforcement was about 1.5 times less than that of the control specimen. Numerical analysis showed that the permeable, flexible pavement structure with the geogrid reinforced subbase also exhibits less development of rutting throughout the service life. This reduction in rutting led to a 20% decrease in thickness of the subbase layer, which might be beneficial to reduce construction costs unless the structural adequacy is not ensured. In the near future, further verification must be conducted, both experimentally and numerically, to support these findings.

Design of fluorescent blue emitting materials according to analyses of chemical structures and its effects

권혁민,박종욱 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.1

Highly efficient chrysene emitters based on side groups optimized for dark blue emission

권혁민,박종욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Diphenylamine substituted with methyl groups was used as a side group to realize high efficiency chrysene dark blue emitters. Three chrysene derivatives substituted with side groups were successfully synthesized: tetra-otolylchrysene-6,12-diamine (o-DPAC), tetra-mtolylchrysene- 6,12-diamine (m-DPAC), and tetra-p-tolyl-chrysene-6,12- diamine (p-DPAC). The maximum PL emission wavelengths of the three materials in solution and in a film were shortest for o-DPAC and longest for p-DPAC. The highly twisted structure of o-DPAC showed the narrowest FWHM (47 nm) in the deep blue region with a PLmax of 449 nm in the film state. The hree synthesized materials showed excellent thermal stability with a high Td over 370 °C. EML was applied to a non-doped OLED device considering the band gap of synthesized materials. Among the synthesized materials, the m-DPAC device achieved excellent EL performance of CIE x, y (0.14, 0.09), 4.89 cd/A, 3.60 lm/W, and an EQE of 6.18%.

Multi-Phenylated Carbazole emitters for OLED via Diels-Alder Reaction

권혁민,박종욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

We synthesized multi-phenylated carbazole derivatives such as 3,6-Bis [(2,3,4,5-tetraphenyl)phenyl]-9-ethylcarbazole(BTPEC) and 3,6-Bis(7,10- diphenyl-fluoranthene)-9- ethlycarbazole(BDPEC), through Diels-Alder reaction. These products were identified by NMR, Fab-Mass analysis. Electro-optical properties of these materials were characterized by cyclic voltammetry and, UV-visible and photoluminescence spectra. The maximum absorbance of BTPEC appeared at 307 nm and BDPEC showed maximum absorbance of 307 nm and 388 nm. And two compounds also exhibited PL peaks at 389 nm and 483 nm. When we used these two materials as hole injection layer and hole transport layer in OLED device, the devices showed about 3 cd=A and 2 cd=A, respectively.

회전하는 수조에서 나타나는 순압성 소용돌이의 패턴과 트라이폴라 소용돌이의 구조적 회전

권혁민,오영록,김태연 한국지구과학회 2013 한국지구과학회지 Vol.34 No.3

In this study, the patterns of barotropic vortices and their structural rotation were investigated through laboratory experiments. Both stable and unstable barotropic vortices were formed in a rotating water tank with a rotating circular plate depending on the diameter, direction, and speed of rotating circular plate. The patterns of stable vortices turned out to be tripolar, triangular, rectangular, and monopolar vortex. These vortex patterns were affected by the gap between the circular plate and the wall of the water tank. Many unstable vortices were formed by anticyclonically and highly rotating circular plate. These results were caused by the centrifugal instability. The structural angular velocity of the tripolar vortex increased with the tangential velocity of the circular plate. The anticyclonic tripolar vortex had higher structural angular velocity than the cyclonic vortex. The tripolar vortex in the water tank was very similar with the real oceanic tripolar vortex from the view point of the Rossby number and the structural rotation. 회전하는 수조에서 나타나는 순압성 소용돌이의 패턴과 구조 회전에 대한 연구를 수행하였다. 소용돌이는 수면 위에 접촉된 원판을 수조에 대해 상대적으로 회전시키는 방법을 통해 만들어졌다. 회전원판의 크기, 회전방향, 회전속력에 따라 트라이폴라 소용돌이, 삼각형 소용돌이, 사각형 소용돌이, 커다란 원형 소용돌이가 안정하게 나타났고, 모양이 계속 변하는 불안정한 소용돌이도 나타났다. 회전원판과 수조 벽 사이의 간격이 안정한 소용돌이의 패턴에 큰 영향을 주었고 불안정한 소용돌이는 원판이 시계방향으로 빠르게 회전할 때 주로 나타났는데, 그 원인은 원심력적 불안정성이었다. 한편, 트라이폴라 소용돌이에서 나타난 전체 패턴의 구조적 회전 각속도는 원판 가장자리의 선속도에 비례하였고, 고기압성 트라이폴라 소용돌이가 저기압성 보다 더 큰 구조 회전 각속도를 가졌다. 로스비 수와 구조회전의 관점에서 볼 때, 해양에서 발견된 트라이폴라 소용돌이와 본 실험에서 나타난 트라이폴라 소용돌이는 유사하였다.

Electroluminescence properties and synthesis of novel deep blue emitting 6,12-dihydro-diindeno[1,2-b;10,20-e]pyrazine derivatives

권혁민,박종욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

A Deep blue emissive material with a new core structure containing indenopyrazine was synthesized; A non-doping device using one of these materials as a blue emitter was found to exhibit high external quantumn efficiency of 4.6% and magnificiant color purity of (0.154, 0.078) as well as narrow emission band of 47nm FWHM.