• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.54.3-55
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• 2017

The nature and physical environments of SNRs are diverse, and for this reason, the understanding of the properties of nearby SNRs is useful in interpreting the emission from SNRs in remote galaxies where we cannot resolve them. In this regard, the LMC is a unique place to study SNRs due to its proximity, location, and composition compared with our galaxy. We carried out a multi-wavelength study of SNR N63A in the LMC, a young remnant of the SN explosion of one of the most massive (> 40 Msun) stars in a cluster. It is currently expanding within a large H II region formed by OB stars in the cluster and engulfing a molecular cloud (MC). As such, N63A is a prototypical SNR showing the impact of SN explosion on the cluster and its environment. Its morphology varies strongly across the wave bands, e.g. the size in X-ray is three times larger than in optical. However, the bright optical nebula would correspond to a MC swept up by the SNR, and consequently the interaction SNR-MC is limited to the central portion of the SNR. We aimed to study the overall structure of N63A, using near-IR imaging and spectroscopic observations to obtain the physical parameters of the atomic shocks, and also to understand how the SNR- MC interaction works and reveal the structure of the shocked cloud as well as the consequences of the impact of the SNR shock on the MC, comparing information obtained in different wavelengths.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.9
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• pp.988-993
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• 2004

Luminescence characteristics of Ag-doped ZnO as the quantum dot materials to increasing the efficiency on dye-sensitized solar cells (DSC) have been studied. Ag doped ZnO powder was produced by the self-sustaining combustion process using ultrasonic spraying heating method. Luminescence wavelength region of the ZnO by Ag doping was shifted to longer wavelength. Tn the case of the Ag doped ZnO powder, broad luminescence spectrum centered on 600nm was observed. On the other hand, we compared PL data of RTA treated ZnO:Ag film at various temperatures because the front electrode of solar cell was in need of the sintering process. In XRD and PL data for RTA treated film at the 500$^{\circ}C$ showed good property. And, it was found that the grain size wasn't growing but only optical property was changed. According to the result of XRD, PL, absorption, emission spectrum and DV-X${\alpha}$ used in theoretical calculation, it is considered to be possible to use Ag doped ZnO as quantum dot material for improving DSC efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.484-491
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• 2004

C-band pumping effect appears in L-band EDFA because the absorption in C-band occurs dominant under the condition of such a low average population inversion. In this paper, we show how the C-band pumping effect depends on 980nm pump power, the C-band wavelength, and its input power. The C-band pumping is caused by absorbing C-band injection or backward spontaneous emission power through EDF. If the same small signal condition is given by a C-band pump, the C-band pump of a long wavelength is good for the saturation and noise characteristics of L-band signal. Finally, it is considered that in the aspect of saturation characteristics, C-band compensation is not so much efficient as L-band in Gain-Clamped L-band EDFA having a lossy resonator.

• Laser Solutions
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• v.14 no.3
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• pp.7-11
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• 2011

As an active emission display using emissive polymer has had much attention recently, needs for a selective patterning of emissive layer for those displays have been increased abruptly. Therefore, the various laser sources in terms of its wavelength has been used for laser direct patterning. In this work, the feasibility of those processes is examined using numerical analysis and the experimental investigation. A sample has multi-layered structure, emissive polymer on aluminum which is deposited on a glass substrate. Key factors for optimizing the laser patterning of the emissive polymer are considered into the control of ablation products, large-sized particle, and the choice of the appropriate wavelength for minimizing the heat affected zone and the remnant layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.518-521
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• 2002

New luminescent material, 6,11-Dihydroxy-5,12-naphthacenedione$(Alq_2-Ncd)$ was synthesized. And extended efforts have been made to obtain high-performance electro-luminescent(EL) devices, since the first report of organic light-emitting diodes(OLEDs) based on tris-(8-hydroxy-quinoline)aluminum$(Alq_3)$ Current-voltage characteristics, brightness-voltage characteristics, luminous efficiency and quantum efficiency were measured at room temperature. The maximum wavelength of the EL is at around 504nm and the brightness is up to $2702[cd/m^2]$ with the maximum efficiency up to 3.91 [1m/W]. This study indicates not only the sterical effect but also some other effect would be responsible for the change of the emission wavelength.

• Journal of Integrative Natural Science
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• v.3 no.2
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• pp.117-121
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• 2010

Silicon quantum dots base on photoluminescent porous silicon were prepared from an electrochemical etching of n-type silicon wafer (boron-dopped<100> orientation, resistivity of 1~10 ${\Omega}-cm$) and used as a alcohol sensor. Silicon quantum dots displayed an emission band at the wavelength of 675 nm with an excitation wavelength of 480 nm. Photoluminescence of silicon quantum dots was quenched in the presence of alcohol vapors such as methanol, ethanol, and isopropanol. Quenching efficiencies of 21.5, 32.5, and 45.8% were obtained for isopropanol, ethanol, and methanol, respectively. A linear relationship was obtained between quenching efficiencies and vapor pressure of analytes used. Quenching photoluminescence was recovered upon introducing of fresh air after the detection of alcohol. This provides easy fabrication of alcohol sensor based on porous silicon.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.315-319
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• 1999

Properties of both photoluminescence and long-phosphorescent for Eu, Dy-codoped $SrAl_2O_4$ powder phosphor synthesized by solid reaction method were investigated by PL instrument. Two intense peaks in the emission spectrum measured at 10 K are observed near 450 nm (2.755 eV) and 520 nm (2.384 eV) wavelength, but at 300 K the main peak of 520 nm wavelength is presented. After the removal of light excitation (360 nm), the excellent after-glow characteristic of the phosphorescence were obtained as a result of low decay tiem, although the after-glow intensities of phosphor vary exponentially with the times.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3610-3613
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• 2011

CdS nanoparticles (NPs) were synthesized in an aqueous phase in order to investigate their spectral behaviors as efficient fluorescence resonance energy transfer (FRET) donors for various organic dye acceptors. Our prepared CdS NPs exhibiting strong and broad emission spectra between 480-520 nm were able to transfer energy in a wide wavelength region from green to red fluorescence dyes. Rhodamine 6G (Rh6G), rhodamine B (RhB), and sulforhodamine 101 acid (Texas red) were tested as acceptors of the energy transfer from the CdS NPs. The three dyes and synthesized CdS NPs exhibited good FRET behaviors as acceptors and donors, respectively. Energy transfers from the CdS NPs and organic Cy3 dye were compared to the same acceptor Texas red dye at different concentrations. Our prepared CdS NPs appeared to exhibit better FRET behaviors comparable to those of the Cy3 dye. These CdS NPs in an aqueous solution may be efficient FRET donors for various organic dyes in a wide wavelength range between green and red colors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.7
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• pp.650-657
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• 2007

This paper had mentioned about CCP light source application for increasing the efficiency of Xe lamp the mercury-free lamp. In order to increase the efficiency of Xe EEFL, we designed and manufactured the lamp used by mixture gas of Xe, Ne and He. Also, we have analyzed the electrical and optical properties with the firing voltage, sustain voltage, paschen's curve, wall charge, and capacitance. As a result, the firing voltage decreased by increasing the ration of mixture gas. and, It is owing to include the gas with high ionization energy. The firing voltage decreased in condition happening the penning effect, Because the ion of metastable state created from penning effect, Which can encourage the ionization phenomena. Also, the wavelength of 467.12 is increase. because of the energy transition in the wavelength of 147 nm. therefore, we can know about the affection of phosphor with UV emission properties. Through an experiment, Xe 100 % and Xe 75 % confirmed same spectrum properties by each mixture gas ratio. In the case of Xe 50 %, spectrum properties appeared Xe discharge and Ne-He discharge. That analyzed an electrical and optical properties. Therefore, confirmed that is excellent because properties of firing voltage, wall charge, capacitance in Xe 50 %, Ne : He = 9 : 1. We offered parameter in inverter manufacture and lamp manufacture by electrical and optical properties.

• Bulletin of the Korean Chemical Society
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• v.21 no.5
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• pp.483-486
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• 2000

A method is described for the fluorimetric determination of nickel, based on the formation of $Ni(II)-\alpha-(2-Benzimidazolyl)-\alpha'$, $\alpha''$ -(N-5-Nitro-2-Pyridylhydrazone)-toluene complex in the presence of a non-ionic surfactant. The complex has practically no fluorescence in the absence of surfactant, but the addition of Triton X-100 makes possible the fluorimetric determination of low concentrations of Ni(II) as it enhances the fluorescenceintensity of the complex by up to about 5-fold. This method is very sensitive and selectrive for the direct determination of nickel ion. The optimum conditions are a Triton X-100 concentration of 2.0 mL(5.0%, v/v) and pH $9.0\pm0.2(ammonium$ chloride-ammonia buffer). The fluorescence is measured at 337 nm of emission wavelength under 300 nm of excitation wavelength. The fluorescence intensity is a linear function of the concentration of Ni(II) in the range 5-70 ng/mL, and the detection limit is 2.0 nm/mL. The proposed method has been successfully applied to the determination of trace amounts of Ni(II) in food and human hair samples.