• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.131-132
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• 2008

Several squarylium dyes, derived from benzothiazole and indoles, were synthesized as a potential NIR dyes with absorption in the 700-900 nm region. These chromophores were induced much more bathochromic shift in the absorption maximum of the compound relative to the neutral parent squarylium dyes which we were described before. The squaryliums offer a convenient way of linking the dye to functional substrates and may be an advantage to be potential chromophores for NIR-absorbing, NIR-Cut-off filter, PDT(Photo Dynamic Therapy) materials.

• Journal of Photoscience
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• v.8 no.1
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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.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1569-1571
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• 1996

The role of ESR spectroscopy in the characterization of functional LB films is discussed. Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly dependant on the combination of dyes. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. In structural studios, ESR is of particular important in the analysis of molecular orientation of LB films. Development of new functional LB films may provide more cases where ESR spectroscopy will clarify the nature of such films.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.193-198
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• 1999

Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of fatty acid. The displacement current was generated from monolayers on the water surface by monolayer compression and expansion. Displacement current was generated when the area per molecule was about $130{\AA}^2$. MDCs were investigated in connection with monolayer compression cycles. It was found that the current pulses were generated over the entire range of molecular area, and the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. We investigated the change in absorption spectra of the fatty acid(8A5H) monolayer LB film due to cis-trans photoisomerization. It was found that the absorption spectrum of the 8A5H LB film was induce to photoisomerization by alternate irradiation with UV and visible light irradiation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.97-100
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• 1994

The present paper is devoted to the physical and electrical characteristics of N-docosyl- quinolinium-TCNQ films compared with the films doped with I$_2$. Iodine affects the degree of charge transfer and the conductivity of the films. The UV-visible absorption spectra of the film doped with I$_2$ shows that the peak of I$_3$ which had electronic transition at 300∼350nm and (TCNQ-)$_2$ dimer absorption disappered. The in-plane electrical conductivity of the films doped with I$_2$ were 1.4${\times}$10$\sub$-6/S/cm, which is two orders of magnitude higher conductivity than undoped LB films. The film structural difference between Y and Z-type may cause the conductivity. Another possible reasons of the structural difference was the overlapping TCNQ anion radical in LB films.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.302-305
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• 2007

During the CareBeijing campaign in September 2006, Imaging Differential Optical Absorption Spectroscopy (IDOAS) measurements were made over the city of Beijing, China using a spatial resolution of 146 pixels horizontally and 61 pixels vertically, each with a field of view of $0.133^{\circ}$ and $0.072^{\circ}$ in the horizontal and vertical directions, respectively. Using Fraunhofer reference spectra (FRS) for the evaluation of data for two consecutive days, the diurnal variation of $NO_2$ distributions was determined from data measured every single hour from 08:00 until 16:00 on September 9 and 10. Both days presented a fairly clear sky with high visibility. The setup allowed detailed images of the low surface $NO_2$ distribution over Beijing. Images with less than a 30-min temporal resolution showed variation of plume dispersal in both horizontal and vertical directions. An in-situ measurement was also conducted. Results from both instruments are interpreted by considering local emission sources and wind conditions.

• Textile Coloration and Finishing
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• v.28 no.3
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• pp.156-163
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• 2016

The 6 novel super hydrophobic bluish-green dyes, showing the maximum absorption at 600~650nm, were synthesized to dye polyolefin fibers such as polypropylene and high strength polyethylene fibers. Their absorption spectra appeared almost the same at visible range, which meant the length of alkyl substituents did not affect on color appearance of the dyes. The optimum length of alkyl group was determined as hexyl substituents from the practical point of view. From the dyeing results, the optimum dyeing condition was $130^{\circ}C$ for 1 hour. The good fastness ratings to washing, rubbing were obtained showing 4-5 for both fibers. Light fastness was obtained also good rating 4 for both fibers.

• Korean Journal of Microbiology
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• v.10 no.3
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• pp.109-116
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• 1972

Three strains among 120 adenineless mutants of Brevibacterium ammoniagenes described in the previous paper were screened out to accumulate UV absorbing substances in the culture broth. It was analyzed to be 5'-inosinic acid and hypoxanthine by means of two dimensional paper chromatography, UV absorption spectra and periodate oxidation. 5'-IMP was isolated from the culture broth of the mutant No. 203 with anion-exchange resin amberite IRA-400 and recrystallized from ethanol. It was proved identical to authentic sample by Infra-red absorption spectrum. The growth responses of the mutant No. 2013 were demonstrated to require adenine, but not with adenosine and 5'-AMP.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.36.1-36.1
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• 2014

The correlation between mass of Type Ia Supernova (SN Ia) host galaxies and Hubble residual is now well-established. The origin of this relation, however, is yet to be understood. We have used low-resolution spectra of early-type hosts from YONSEI (YOnsei Nearby Supernovae Evolution Investigation) project to measure central velocity dispersion and Lick/IDS absorption indices. By using the Evolutionary Population Synthesis (EPS) models, luminosity-weighted mean age and metallicity of host galaxies were determined from $H{\beta}$ and absorption lines. Here we will discuss the correlation between the velocity dispersion, which indicates the mass of galaxies, and mean age of stellar population in our sample of early-type host galaxies.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.651-654
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• 2009

Novel compounds with rod and disc mesogens were synthesized and characterized. The molecular structures were confirmed by FT-IR, $^1H$-NMR spectroscopy and elemental analysis. The optical properties of these molecules were investigated by UV-vis absorption spectroscopy and photo-luminescence spectroscopy. We found that they are a novel series of blue light-emitting molecules. The absorption spectra peaks of these compounds varied from 336 nm-341 nm, while the maximum emissions centered form 410 nm-450 nm in chloroform solution. However, unexpectedly we could not found their biaxiality and mesomorphic properties by POM, conoscopy and DSC method.