• 한국전기전자재료학회논문지
• /
• 제22권4호
• /
• pp.323-326
• /
• 2009

We have developed blue-emitting phosphorescent organic light emitting diodes (OLEDs) using 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and tris (8-quinolinolato)aluminum ($Alq_3$) electron transport layers. As blue dopant and host materials, bis[(4,6-di-fluorophenyl)-pyridinate-N,C2']picolinate (FIrpic) and N,N'-dicarbazolyl-3,5-benzene (mCP) were used, respectively. The driving voltage, current efficiency and emission characteristics of devices were investigated. While the driving voltage was about $1{\sim}2$ V lower in the device with an $Alq_3$ layer, the current efficiency was about 66 % higher in the device with BCP electron transport layer. the blue phosphorescent OLED with BCP layer exhibited higher purity of color, resulting from a relatively weak electroluminescence intensity at 500 nm.

• Archives of Pharmacal Research
• /
• 제9권1호
• /
• pp.45-47
• /
• 1986

Phenylglycine was obtained as the sole metabolite when .alpha.-aminophenylacetonitrile was ted to the culture broth of Aspergillus furmigatus furmigatus. The isolated phenylglycine showed L-configuration with 80% optical purity. Examination of the hydrolysis of the substrate to phenylglycine with cell free extracts, and the supernatant fraction and the particulate fraction both of which were obtained after ultracentrifugation of the cell free extract at 100,000g, indicated that the nitrile group hydrolyzing enzymes, nitrilase existed not only in cytoplasm, but in microsome fractions.

• 통합자연과학논문집
• /
• 제8권2호
• /
• pp.111-116
• /
• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acid esters as nitrobenzoxadiazole (NBD) derivatives was performed using several chiral stationary phases (CSPs) based on polysaccharide derivatives under fluorescence detection. For enantiomer separation by normal HPLC, the non-aqueous derivatization method of ${\alpha}$-amino acid esters for NBD analytes was introduced. Among the six CSPs used in this study, the performance of Chiralpak IA was superior for enantiomer resolution of NBD derivatives of several ${\alpha}$-amino acid methyl esters. Also the convenient analytical method using polysaccharide-derived CSPs developed in this study was applied to determine the optical purity of ${\alpha}$-amino acids esters. It was investigated that the enantiomeric impurity levels of 0.02-1.73% were found after determination of enantiomeric purities of several commercially available L-amino acid methyl esters. It is expected to be quite useful for enantiomer separation of other ${\alpha}$-amino acid esters as NBD derivatives by normal HPLC.

• 공업화학
• /
• 제5권1호
• /
• pp.176-181
• /
• 1994

시판되고 있는 4종류의 Lipase(talpase, paratase M1000L, SP398, SP435)를 이용하여, 2-[1-(1-acetoxy-2, 2, 2-trifluoroethyl)]-5-trimethylsilylfuran(1)을 속도론적 광학분할에 의해서 가수분해반응을 검토했다. 그 결과 Novo Nordish사의 SP435가 속도론적 광학분할능을 가진다는 것을 확인했으며, 본 실험에서는 광학순도 92.4% enantiomeric excess(ee)를 가지는 생성물 2-[1-(2, 2, 2-trifluoro-1-hydroxyethyl)]-5-trimethylsilyfuran(2)를 얻었다.

• 전자공학회논문지D
• /
• 제34D권7호
• /
• pp.62-70
• /
• 1997

In this paper, the optical conditins of a reflective multi-color STN-LCD based on electrical control of birefringence is designed on the poincare sphere. First of all, the angles of polarizer and analyzer for the best color purity are decided in the configuration without a retardation film. A retardation film is introduced for a bright white in the range of the applied voltage. The sretardation and the angle of the retardation film are also decided on the poincare shpere. The test cell is farbricated and its measured spectral transmittance and the CIE chromaticity diagram agree well with simulations.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.788-791
• /
• 2002

The phosphors of high luminous efficiency for PDP application must have high purity, single phase, and dense surface. In this work, the polymeric reaction was applied to preparation of spherical phosphor by aerosol pyrolysis in order to enhance mechanical and optical characteristics. The red phosphor of (Y,Gd)$BO_3$:Eu was prepared from polymeric precursor, in which citric acid and ethylene glycol were used as ion carriers, i.e monomers. For enhancing the luminescence intensity and mechanical characteristics. optimum synthesizing condition were investigated through concentration of monomers, synthetic temperature. doped activator concentrations, and annealing process. The phosphors synthesized with monomers showed quite different morphology from those without monomers. It was observed that polymeric precursor made an effect on particle formation mechanism and status of particles surface. The resultant spherical phosphors show the comparable luminescent properties to the commercial product (product by Nichia co.). Also, they were observed to have the rigid surface.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.491-493
• /
• 2002

Liquid chromatographic direct resolution of racemic naphthyl propionate liquid crystals were successful on a commercial chiral column, (S,S)-Whelk-O1. The very simple procedure can be applied to the intermediate and final products without any structural modification.

• Applied Science and Convergence Technology
• /
• 제25권1호
• /
• pp.1-6
• /
• 2016

Quantum dots (QDs) are considered as excellent color conversion and self-emitting materials for display and lighting applications. In this article, various technologies which can be used to realize white light emission with QDs are discussed. QDs have good color purity with a narrow emission spectrum and tunable optical properties with size control capabilities. For white light emission with a color-conversion approach, QDs are combined with blue-emitting inorganic and organic light-emitting diodes (LED) to generate white emission with high energy conversion efficiency and a high color rendering index for various display and lighting applications. Various device structures for self-emitting white QD light-emitting diodes (QD-LED) are also reviewed. Various stacking and patterning technologies are discussed in relation to QD-LED devices.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2015년도 추계학술대회 논문집
• /
• pp.221-221
• /
• 2015

폐 자원에서 회수한 주석 조금속의 주석 순도 및 불순물 순도, 전해정련 및 진공정련 후 주석 순도를 ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer)분석을 통해 확인하였다. 무기산 전해액에서 전해정련 수행결과 고순도 주석을 확보하였고, 이후 증기압, 온도 및 유지시간 별 진공정련 수행결과 초고순도 주석을 회수할 수 있는 최적화 기술을 도출하였다.

• KSBB Journal
• /
• 제30권4호
• /
• pp.197-201
• /
• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acids and their methyl and ethyl esters as fluorenylmethoxycarbonyl (FMOC) derivatives was performed using a recently developed chiral column (Chiralpak IE) based on polysaccharide derivative under simultaneous UV detection and fluorescence detection. The degree of enantiomer separation of ${\alpha}$-amino acid esters as FMOC derivatives is generally higher than that of the corresponding ${\alpha}$-amino acids. Especially, ${\alpha}$-amino acid methyl esters showed the greatest enantioseparation. As this method developed in this study can be applied to determine the chemical and optical purity of ${\alpha}$-amino acids and esters, it is expected to be quite useful for their chiral separation using Chiralpak IE.