• Journal of Photoscience
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• 제12권3호
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• pp.185-186
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• 2005

The electronic structure of photoskinsensitizing psoralens has been investigated by the ab initio calculations. The photocycloaddition reaction of 8-methoxypsoralen with thymine is studied as a model for the photosensitizing reaction of psoralen with DNA bases. The photocycloadduct was inferred to be a C4-cycloaddition product with the stereochemistry of Syn, H-H, Syn, H-T formed through [2+2] addition reaction between the 3,4-double bonds of 8-methoxypsoralen and 5,6-double bond of thymine base.

• Bulletin of the Korean Chemical Society
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• 제8권5호
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• pp.376-380
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• 1987

The cyclobutane forming photocycloaddition reaction of 5(E)-styryl-1,3-dimethyluracil with some olefins occurs on the 5,6-double bond of uracil ring rather than the expected central double bond via an intermediate, probably the photochemical Diels-Alder type adduct. This intermediate formed on short term irradiation of 5(E)-styryl-1,3-dimethyluracil and 2,3-dimethyl-2-butene solution is converted into the $C_4$-cycloadduct on the prolonged irradiation. Quantum yield of the intermediate formation is not linear with the concentration of 2,3-dimethyl-2-butene probably due to the secondary reaction accompanied with the complex reaction kinetics. The intermediate is formed from the lowest excited singlet state.

• Archives of Pharmacal Research
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• 제18권3호
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• pp.195-202
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• 1995

The thio, thio acetyl, oxime, and several hydrazone and azine derivatives of the antitumor alkaloid acronycine (1) were prepared. NMR spectroscopy was used to study the configurations around the C=N double bond in these acronycine derivatives. In the hydrazones and azines of acronycine the N-N bond assumes a syn configuration to the $C_6-OCH_3$ group, while the NO bond in the oxime and the N-N bond in noracronycine hydrazone and azines assumes an anti configuration.

• 한국결정학회지
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• 제8권1호
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• pp.1-5
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• 1997

표제화합물의 결정구조는 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium, $C_{16}H_{19}N_2$와 tosylate, $C_7H_7SO_3$의 불연속한 이분자체로 구성되어 있다. 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium 분자는 중간에 있는 C=C double bond에서 trans conformation을 가지고 있으며 phenyl 및 pyridyl ring들간의 이면각은 $5.7(2)^{\circ}$을 이루어 전분자는 $0.138(8){\AA}$ 내에서 평면을 이루고 있다. Tosylate 분자들은 거리가 각각 2.855(9) and $2.899(8){\AA}$인 O-H...O 수소결합으로 연결된 이분자체를 나타내고 있다. 이 두 분자간의 가장 가까운 거리는 O(3)와 C(16) 원자간의 $3.10(1){\AA}$이다.

• 자원리싸이클링
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• 제13권3호
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• pp.37-42
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• 2004

폴리염화비닐(PVC)을 0∼2M NaOH 수용액 중에서 반응온도 $200∼250^{\circ}C$, 반응시간 0∼5시간으로 수열 처리한 경우 탈염화수소한 PVC 잔류물의 형상과 구조를 조사했다. 잔류물의 형상은 NaOH 농도에 의해 크게 변화하였다. 수중에서는 잔류물이 응집하고, 표면에서는 약 10$mu extrm{m}$이하의 세공이 생성되었다. 또한 잔류물의 내부는 총총한 망상구조로 되어 있었다. 반면에 NaOH 수용액 중에서는 잔류물의 응집이 거의 관찰되지 않았고 비교적 구상이었다. 그리고 $250^{\circ}C$에서 수중과 NaOH 수용액 중에서의 잔류물의 IR Spectrum을 관찰한 결과 C=C 이중결합에 의한 흡수피크 및 방향환의 생성이 나타났다. 폴리염화비닐을 NaOH용액으로 탈염화수소처리시 잔류물에서는 분자 내 및 분자간에서 환화반응 또는 가교반응이 일어나는 것을 알 수가 있었다.

• Composites Research
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• 제19권4호
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• pp.23-30
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• 2006

극저온 추진제 탱크를 개발하는 과정에서 복합재와 알루미늄 라이너를 접합하기 위한 접착제의 선택은 탱크의 안전성과도 직결된 매우 중요한 문제이다. 따라서 적합한 극저온용 접착제를 선택하기 위해 3종류의 접착필름이 선정되었으며 극저온용으로 개발된 탄소섬유/에폭시와 라이너 재료로 사용되는 알루미늄으로 구성된 양면 겹치기 조인트 시편을 제작하였다. 제작된 시편을 극저온 환경챔버를 사용하여 상온과 $-150^{\circ}C$에서 인장실험을 수행하여 각 접착제의 접착강도를 비교하였으며 파손 특성을 분석하였다. 또한 양면 겹치기 조인트 시편의 각 구성재료의 온도에 따른 기계적 물성변화를 측정하였으며 이를 이용하여 ABAQUS를 통한 유한요소해석을 수행하여 양면 겹치기 조인트 시편의 인장시험결과를 분석하였다.

• EDISON SW 활용 경진대회 논문집
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• 제2회(2013년)
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• pp.238-239
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• 2013

We studied the thermal and electron properties of covalent one-dimensional (1D) monatomic linear chains of carbon, particularly carbyne. We found the ${\alpha}$-carbyne (Polyyne, alternating single and triple C-C bond co-existing) is more stable than ${\beta}$-carbyne (Equally-spaced based on C-C double bond) energetically. As investigation of electron density of states (EDOS), polyyne and cumulene had different electronic characteristic, which corresponding metallic and semiconducting respectively. We also calculate the phonon dispersion, phonon density of states (PDOS) and phonon transmission of carbynes.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.745-751
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• 2009

The anchor is used extensively for a cutting slope, an earth retaining wall, an uplift resistance of sub-structures and so on at civil engineering projects and is classified by aim in use, tendon material, and ground/tension fixing type. It can be distinguished extensively into friction type, bearing type, and complex type by ground fixing type. Generally, bond length of friction type anchor has application to 3~10m depending on the friction-resistance characteristics. In this study, 'DEW(double enlargement wedge) bearing type anchor' of new concept is devised. The bond length is about 0.6~0.8m. It can be used on the ground to have the strength characteristics above it of weathered rock. There are merits which are 'period reduction' and 'cost saving' through the minimum of the boring length. In addition, it is so called environmentally friendly Methods because it can reduce the quantity of carbon dioxide through the reducing drilling machine operation time.

• 대한치과보철학회지
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• 제29권2호
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• pp.195-209
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• 1991

When the porcelain fused to metal restorations were fractured at the metal interface, various techniques and materials for intraoral porcelain repair have been suggested. The purpose of this study was to investigate the effect of metal surface treatment method and water storage on the shear bond strength of four porcelain repair systems. : Clearfil(Kuraray), All-bond(Bisco), Superbond C & B(Sun Medical), Panavia OP(Kuraray). After the metal surfaces of the specimens were sandblasted by aluminum oxide or roughened by diamond point, they were stored in double deionized water(24 Hr., $37^{\circ}C$) and thermocycling was performed(24 Hr., 1024 cycles), and again half of specimes were stored in water bath(2 Months, $37^{\circ}C$). Mean shear bond strength and mode of failure were recorded. The results of this study were obtained as follows : 1. Differences were observed between the sandblasted and diamond - treated specimens in Clearfil, All-bond, and Superbond. No statistically significant differences were observed in Panavia. 2. The 2-month storage time significantly affected the bond strength of All-bond and Superbond. No statistically significant differences were observed in Clearfil and Panavia. 3. The failures were observed at the interface between opaque resin and the metal in Clearfil and All-bond. 4. The failures were observed at the interface between opaque resin and veneered resin in Panavia. The failures were observed at the interface between opaque resin and veneered resin in Superbond, but 40% of them were fractured at the interface between the metal and opaque resin after 2-month storage time.

• 한국결정학회지
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• 제15권1호
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• pp.1-4
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• 2004

上記 題目의 化合物, $C_{18}H_{20}O_5S$은 한 對非稱 單位內에 한 個의 分子를 가지고 對稱中心室間群 $P\={1}$로 結晶化 되었다. sulfonate 群內ml S 原子는 O와 C 原子들로 이루워진 四面體 環境을 維特하고 있으며, S-O 二重結合 平均 길이는 1.420(2) ${\AA}$이며 S-O 單一結合 길이는 1.598(2) ${\AA}$이고 S-C 結合 길이는 1.742(3) ${\AA}$이다. C(7)-S-O(3)-C(8) 의 비틀림 角은 100.3(2)$^{\circ}$이며, 두 個의 six-membered rings의 二面角은 42.73(20)$^{\circ}$이다.