• 디지털융복합연구
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• 제19권11호
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• pp.341-349
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• 2021

최근 조명 산업이 중요한 분야로 인식되면서 PQR (Photonic Quantum Ring) 소자는 LED(Light Emitting Diode)를 대체할 수 있는 차세대 광원이 될 전망이다. 본 연구에서는 기존 연구와 유사한 결과를 검증하고, 소자의 광특성을 분석하기 위해 광섬유가 연결된 스테이지에 x, y, z 좌표를 입력하면 자동으로 이동하며, 또한, 소자에 광섬유를 근접시키는 NSOM (Near field scanning optical microscopy) 장치를 추가한 측정 시스템을 이용하여 소자의 광특성 실험과 공진 및 어레이 소자의 광특성 시뮬레이션을 통해 조명용 소자로 가능성을 검증하고자 하였다. 이를 위해 메사와 홀 형태가 동시에 존재하는 메사 직경 40㎛, 홀 직경 3㎛의 소자를 제작하여 소자의 근접장으로 PQR 소자는 ㎂에서 동작하며, 메사와 홀 소자는 서로 독립적으로 구동됨을 관찰하였다. 위치에 따른 소자의 광파장 스펙트럼을 측정하여 메사와 홀 소자에 의한 커플링 현상을 처음으로 확인하였다.

• 한국염색가공학회지
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• 제3권1호
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• pp.25-27
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• 1991

New Series of diazaanthraquinone near-infrared dye was synthesised by the ring closure reaction between 2,3-dibromodiazaanthraquinone and potassium 2-aminobenzenethiololate. This dye absorbs near-infrared light at 780 nm.

• Bulletin of the Korean Chemical Society
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• 제20권5호
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• pp.531-534
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• 1999

Irradiation (300 nm UV light) of dibenzoylmethane and 1,4-naphthoquinone in dichloromethane gave 1,5-dike-tone as the major product, along with β-hydroxyketone as the minor product. Anthraquinone and anthrone also added photochemically to dibenzoylmethane to give 1,5-diketones as the major products. In contrast, tetrahalo-1,4-benzoquinones added to dibenzoylmethane to give two types of 1,5-diketones via oxetane and cyclobutane intermediates. Comparison of the potential energy values of the photoproducts reveals that the 1,5-diketones are more stable than the corresponding oxetanes or cyclobutanes due to the ring-strain of the bicyclic compounds.

• Journal of Photoscience
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• 제8권1호
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• pp.9-12
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• 2001

The photoisomerization behavior of benzylideneacetophenones, known as chalcones, was studied. We synthesized the chalcone derivatives that have ether groups at 4 and 4＇ positions. Due to the electron donating ability of the ether oxygen, the bond order of the single bond between two phenyl ring of the chalcone strengthened, which eventually increased the rotational barrier of the single bond. The rotational barrier of the single bond is about 20-22 kcal/mole. Thermal recovery of this process took about 1 min. The UV-visible spectra of these chromophores exhibit two characteristic absorption peaks at 276 nm and 340 nm. The relative intensity of the peaks varies depending on the alkyl chain length of the substituent. Photo-irradiation with the 365 nm light monotonously decreases the 340 nm peak. However, the photo-irradiation with 254 nm light induce two competing processes and produced rather complicated absorption profile.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.166-174
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• 1998

The distribution of oil film thickness in piston were measured by induced fluorescence method. A Xe lamp was used as light source. Coumarine-6 was mixed with oil as the fluorescent dye. Fluorescent signal which is proportional to the oil film thickness was acquired by CCD camera and transmitted to the personal computer as video signal. In order to solve the problem of measurement system, irregular distribution and unstability of light intensity, as well as to know the relationship between the oil film thickness and output signal, three different calibration techniques were used. Motoring and firing tests were performed in a single cylinder research engine with transparent liner. By analyzing the oil film thickness converted from the photographed image, it was observed that each of three piston rings scrapes the oil both upward and downward and oil film thickness is not uniform horizontally at a given piston land. The amount of oil in each land was considerably affected by the engine load. It is thought that the blow-by gas blows the oil down to the crankcase.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.453-459
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• 2013

In phtosynthetic light harvesting complexes, the electronic transition energies of chlorophylls are influenced by the Coulombic interaction with nearby molecules. Variation of the interactions caused by structural inhomogeneity in biological environment results in a distribution of disordered electronic transition energies of chlorophylls. In order to provide a practical guide to predict qualitative tendency of such distribution, we model four porphyrin derivatives including chlorophyll a molecule interacting with an external positive charge and calculate their transition energies using the time dependent density functional method. It is found that ${\pi}-{\pi}^*$ transition energies of the molecules are generally blue-shifted by the charge because this stabilizes occupied molecular orbitals to a greater extent than unoccupied ones. Furthermore, new transitions in the visible region emerge as a result of the red-shift in energy of an unoccupied Mg orbital and it is suggested that light-induced electron transfer may occur from the tetrapyrrole ring to the central magnesium when the molecules are interacting with a positive charge.

• 한국광학회지
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• 제3권2호
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• pp.86-91
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• 1992

Synchrotron 방사광으로 부터 soft X-ray, 광에너지 300-1200eV, 영역의 특정 파장을 선택할 수 있는 단색화 장치의 설계에 대하여 알아보았다. C.T.Chenㅡ이 새로운 제안에 의해 건설되어 그 성능이 기존의 여러 단색화 장치보다 우수하다고 알려진 Brookhaven National Laboratory의 CEM(cylindrical element monochromator) 형태인 Dragon beam line을 모델로 하여 PLS(Pohang Light Source) 방사광 가속기의 구조에 맞게 광학적 설계시 고려해야할 조건을 조사하였다.

• Journal of Photoscience
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• 제9권2호
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• pp.350-352
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• 2002

We examined the bacteriochlorophyill/bacteriopheophytin ratios in several species of purple bacteria containing only LHI. The pigment ratios depended greatly on species. Further, Rhodospirillum rubrum showed wide variation when grown under different light intensity, and Rhodobium marinum showed significant variation from culture to culture even under the same light conditions. The protein ratios of a/RC and $\beta$/RC estimated by SDS-PAGE of chromatophores of Rsp. rubrum and Rbi. marinum exhibited the ratio of $\beta$/$\alpha$ > 1. These findings gave us the novel idea that there are two types of LHl; one is a C-shaped open antenna composed by $\alpha$$\beta$ units surrounding a RC, and another is a small closed ring antenna composed by $\alpha$$\beta$ units located peripherally in a variable ratio to the core complex like LH2.

• 한국생산제조학회지
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• 제24권4호
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• pp.448-454
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• 2015

In this paper, the band structural design that is typically in a line was arranged in a ring shape, so as to configure the high power LED lighting in such a way as to form a concentrated light distribution angle of less than 15 degrees. The parabolic aluminized reflector PAR38 that facilitates design using area and the area of the optical system to the same extent, applied a multiple light-source condenser lens optical system for the control of integration. The LED used here implemented a single linear light source using ans LED module with ans LED, flip-chip chip-scale package. The optical system was designed based on the energy star standard.

• 한국구조물진단유지관리공학회 논문집
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• 제23권6호
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• pp.120-131
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• 2019

본 연구에서는 빛 감성친화형 콘크리트에 광촉매를 적용하여 대기질 및 실내공기질을 개선하기 위한 LEFC 블록을 개발하고자 하였다. LEFC에 광촉매를 적용하게 되면 자외선 입사면 반대편에서도 투과로 인한 자외선이 존재하여 광촉매가 반응함으로써 일반 건축 자재를 적용한 경우보다 광촉매 반응효율이 크게 상승한다. 따라서 광촉매를 LEFC에 적용하기 위해 슬럼프, J-ring, L-box 테스트를 통한 자기충전성능을 평가하여 최적 배합을 결정하였고, 압축 및 휨 강도 시험을 통해 역학성능을 평가하였다. 그리고 TiO2 분포도를 확인하기 위해 SEM과 EDS 분석을 실시하였다. ALC골재와 단열재 적용으로 광촉매 사용량을 줄이고 단위중량을 감소시키는 방안을 활용하여 광촉매 효율을 증가시키는 빛투과 콘크리트 블록을 제작하였고, 향후 건조수축 등의 문제점 개선 및 NOx 제거 실험을 통한 LEFC 블록 성능 평가를 진행하고자 한다.