• Korean Journal of Pharmacognosy
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• v.7 no.4
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• pp.233-235
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• 1976

Substances $I{\sim}VII$ are isolated from the root of Glehnia littoralis which has been often used as a subsitute of Bang-Poong in Korea. White needle crystalline substance of $C_{29}H_{50}O$, m.p. $137{\sim}139^{\circ}C$ was confirmed as ${\beta}-sitosterol$ through elemental analysis, derivative synthesis, IR and physicochemical tests. Moreover, it was concluded that white needle crystal of $C_{12}H_{8}O_{4}$, m.p. $188{\sim}189^{\circ}$ was confirmed as bergapten, through a contrast test with standard substance and by UV and IR-spectra. It was found that substance III and VII coincided with the Rf values of imperatorin and umbelliferone and to its colors under the UV-ray, and its similarity to UV-spectrum can be recognized, but their melting points are remarkedly different respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1355-1359
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• 2006

Due to its efficient red emission, $Eu^{3+}$ ion has been doped in various host materials. $GdCa_4B_3O_{10}:Eu^{3+}$ phosphor for red emission has been prepared by solid state reaction. Photoluminescence properties for the phosphor under UV and VUV excitation were investigated. The $GdCa_4B_3O_{10}:Eu^{3+}$ phosphor under both excitation conditions shows typical red emission spectrum centered at 611 nm with several weak peaks due to energy transfer from $^5D_O\;to\;^7F_J(J=1,2,3,4)$ of $Eu^{3+}$ ion. On the other hand, the activator content exhibiting the concentration quenching under UV and VUV irradiation is 10 mole% and 2.5 mole%, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.38-42
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• 1996

The pressure-area isotherm of monolayer at the air-water interface were obtained and the LB films were fabricated onto a quartz slides and quartz crystal by conventional Langmuir-Blodggett(LB) method. The UV absorption spectra of Langmuir-Blodggett(LB) film on quartz slides and spectrum of monolayer formed on quartz crystal have been measured. The photoisomerization of the long-chain fatty avid containing azobenzene were obtained by the application of UV and visible light. The reversibility of photoisomerization were more clear difference when the number of C$\_$n/ increased. At the pressure-area isotherms, the value of surface pressure increment were decreased when the number of C$\_$n/ increased, A surface pressure of 20mN/m was obtained as a proper one for a film deposition. The photoisomerization at LB films were also obtained by application of UV and visible light. So the LB film of long-chain fatty acid containing azobenzene has possibility to being applies to functional molecular devices such as photomemory and light switching.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.141-144
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• 2002

Computer code was developed to design waveguide gratings based on coupled-mode equations and the transfer matrix formalism. The experimental set-up has been constructed for inscribing Bragg gratings in planar waveguides with a phase mask and uv laser beam, which enables alignment and packaging of grating devices as well as in-situ performance measurements. Bragg grating has been fabricated on silica planar waveguides with 0.75% Germanium concentration and its transmittance spectrum was measured to have 95% reflectance at the peak wavelength. Optical losses as the function of the misalignment were measured and their usage is described.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.455-455
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• 2013

$CeO_2$ nanorings were synthesized by using a surfactant free hydrothermal method. The surface morphology, structural and optical properties of the synthesized $CeO_2$ was investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible (UV) spectroscopy measurements. SEM images showed that the surface morphology of the formed $CeO_2$ appeared as nanorings. The XRD pattern of $CeO_2$ nanorings showed the presence of the polycrystalline $CeO_2$ phase readily indexed to the cubic fluorite structure of the $CeO_2$. The mean crystallite size of the $CeO_2$ was calculated using the Scherrer equation from the XRD line broadening of the (111) planes of the cubic $CeO_2$. The UV-Visible spectroscopy spectrum of the $CeO_2$ nanorings exhibited a strong UV absorption band around 350 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.479-482
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• 2000

We investigated UV-vis absorbances to observe photoisimerization and effect of temperature using the mixture solution in chloroform and the LB monolayer mixed with DLPE and 8A5H containing azobenzene which shows reversible cis-trans isomerization irradiated by alternate lights. We could find that the absorption spectrum of the mixtures solution and LB monolayer was reversibly induced to photoisomerization irradiated by Uv of both and visible lights, in addition the absorbance by alternate temperatures.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.155.1-155.1
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• 2015

Nowadays, Plasma has been used in biological, medical such as wound healing, plant grow, killing cancer. When plasma generated, UV light and ROS(Reactive oxygen species), RNS(Reactive nitrogen species) can generated and those things effect to biological material. So we made simple plasma device using needle type of electrode and generated plasma. We used three kinds of gas and measured applied voltage and current. Also we observed optical emission spectrum. Using deuterium ramp, we can observed absorption spectrum and calculated radical density by lambert-beer's law. It is around ~1016cm3. And we can see the time-resolved absorption spectrum from monochromator, PMT(photo multiply tube), IV-converter, oscilloscope.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.59-64
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• 1998

Kim & Beuermann (1995, 1996)have developed a model for the propagation of X-rays from the accreting white dwarfthrough the infalling material and the re-emission of the energy deposited by photo-absorption in the optical (and UV) spectral range. By using this model, we calculate the profiles of the $H_{\gamma}$ emission-line spectrum of intermediate polars. Photoabsorption of X-ray by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle, these dependencies allow us to obtain improved insight into the accretion geometry of the intermediate polars. We present results of our calculations and compare them with the $H{\beta}$ line spectrum(Kim & Beuermann 1996).

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.310-315
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• 2003

The dyeing of cotton fabric with Forsythia koreana NAKAI was investigated. The colorant was extracted with methanol under various concentrations of dyestuffs at $40^\circ{C}$ and $76^\circ{C}$. UV-VIS spectrum was obtained to find the maximum wavelength of colorant. Cotton fabrics were dyed at different temperatures, mordants, in pre and post mordanting methods. The maximum wavelength of spectrum were 390nm, 410nm, 440nm. The highest K/S value was showed at 100% dye concentration, extracted at $76^\circ{C}$ and dyed at $80^\circ{C}$. The mordant effect was not good in the K/S values. The light fastness was increased at Fe-pre mordant and Cr, Fe-post mordant.

• Bulletin of the Korean Chemical Society
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• v.1 no.3
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• pp.98-101
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• 1980

For the first time we have synthesized thiabenzene radical by the reaction of thiopyrylium cation with alkali metals. As might be expected for a free radical, ESR-spectrum of 2,4,6-triphenylthiabenzene radical shows the single signal with g-value of 2.0045. The proton signal of 2,4,6-triphenylthiabenzene radical in nmr spectrum shifts to the higher field than that of 2,4,6-triphenylthiopyrylium cation by ca. 0.5 ppm. From the UV-spectrum of thiabenzene radical the presence of 6${\pi}$ non-benzenoid aromatic system was observed as in the case of thiopyrylium cation. The reactivity of alkali metals with thiopyrylium cation increases in the order of decreasing ionization energy, Li