• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.105-107
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• 2002

a-C:H films were coated on windows of mobile telephone by RF plasma chemical vapor deposition equipment made in our company. Thickness of the coatings is about 0.7 micrometers and they have high hardness, low friction coefficient, good adhesion, high optical transparency and chemical inertness. Knoop hardness of the diamond-like carbon films on glass substrate is 2328 kg/mm$^2$. The adherence between films and substrate is good and shows to be 69 N by scratching test. The optical performance is improved obviously owing to coat the film on it. The index of the coated windows is 2.5, transmission of visible light is larger than 90%, and transmission of ultraviolet light decreases by 30% and the ultraviolet light can be obstructed obviously. The coated glass also has self-clean effect and decontamination ability. The films have hydrophobic character and the soakage angle of water drop is larger than 90 degrees. The windows have fog-proof ability owing to eliminate the capillary phenomena in the inner surface. The physics and chemical properties of the coated windows are steady. Study indicates that the performance of a-C:H coated mobile phone windows are improved notably on wear-resistance, corrosion-proof and optical properties and it is excellent mobile windows protective coatings.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.25-29
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• 2015

The determination of the optimum conditions for the conversion of ergosterol to vitamin $D_2$ in shitake mushrooms (Lentinula edodes) was studied using response surface methodology (RSM). The effects of the three main variables ambient temperature ($20-40^{\circ}C$), exposure time (60-180 min), and irradiation intensity ($0.6-1.8W/m^2$) were investigated. According to the RSM ridge analysis, the optimum conditions were as follows: ambient temperature of $34.2^{\circ}C$, exposure time of 175.6 min, and irradiation intensity of $1.41W/m^2$. Under these optimum conditions, the maximum vitamin $D_2$ content of $117.93{\mu}g/g$ in shitake mushrooms was obtained, which agreed fairly well with the predicted value of $122.60{\mu}g/g$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.50-55
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• 2000

In this paper, Thermally Stimulated Current(TSC) spectrum has been measured in oriented polypropylene of thickness of $40{\mu}m$ which was irradiated by Ultraviolet Ray. As a result of the investigation, four peaks have been observed-two peaks ($A_1$, $A_2$) were appeared in low temperature region($-20{\sim}20^{\circ}C$) and other two peaks ($B_1$, $B_2$) in high temperature region($80{\sim}120^{\circ}C$). Among four peaks $A_1$ and $A_2$ have bee observed in detail. These peaks are shown to be created due to the polarization of diploes from the experimental results which were measured as a function forming voltage, forming time, collecting voltage and heating rate. As the increase of irradiated-time by Ultraviolet ray, the number of dipoles was increased.

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.871-875
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• 1998

High aspect ratio microstructures were fabricated by photolithography. The material for the microstructure was photosensitive glass which has good mechanical and electrical insulation properties. The photosensitive glass was exposed to ultraviolet light at 312nm through a chromium mask in which the structures are drawn. After heat treatment process over $500^{\circ}C$, the photosensitive glass was etched in a 10% hydrofluoric acid solution with ultrasonic conditions. Final dimension of the micro-framework was greatly dependent on the thickness of photosensitive glass, mask pattern, ultraviolet light exposure and etching conditions. The maximum aspect ratio of the micro-framework obtained from this work was over 30.

• Korean Journal of Materials Research
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• v.15 no.8
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• pp.496-502
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• 2005

Green-light emitting $BaMgAl_{10}O_{19}:Mn^{2+}$ (BAM:Mn) phosphor particles were prepared by spray Pyrolysis. The effect of reactor temperature and flow rate of carrier gas in the spray Pyrolysis on the morphology, crystallinity and photoluminescence characteristics under vacuum ultraviolet were investigated. The morphology of the as-Prepared Particles obtained by spray Pyrolysis had spherical shape and non-aggregation characteristics regardless of the reactor temperature. The spherical shape of the as-prepared Particles obtained by spray pyrolysis at low temperature disappeared after Post-treatment. On the other hand the as-Prepared Particles obtained by spray Pyrolysis at $1600^{\circ}C$ maintained spherical shape and non-aggregation characteristics after post-treatment at $1400^{\circ}C$ for 3 h under reducing atmosphere. The BAM:Mn Phosphor Particles Prepared by spray Pyrolysis at different reactor temperatures had pure crystal structure and high photoluminescence intensities under vacuum ultraviolet after post-treatment. BAM:Mn phosphor particles prepared by spray Pyrolysis at low How rate of carrier gas had complete spherical shape and filed morphology and high photoluminescence intensity after post-treatment under reducing atmosphere.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.115.1-115.1
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• 2012

The Ultraviolet Coronagraph Spectrometer on board the Solar and Heliospheric Observatory (SOHO) observes low ionization state coronal mass ejection plasma at ultraviolet wavelengths. The CME plasmas are often detected in O VI ($3{\times}10^5K$), C III ($8{\times}10^4K$), $Ly{\alpha}$, and $Ly{\beta}$. Earlier in situ observations by the Solar Wind Ion Composition Spectrometer (SWICS) on board Advanced Composition Explorer (ACE) have shown mostly high ionization state plasmas in interplanetary coronal mass ejections (ICME) events, which implies that most CME plasma is strongly heated during its expansion in solar corona. In this analysis, we investigate whether the low ionization state CME plasmas observed by UVCS occupy small enough fractions of the CME volume to be consistent with the small fraction of ICMEs measured by ACE that show low ionization plasma, or whether the CME must be further ionized after passing the UVCS slit. To do this, we determine the covering factors of low ionization state plasma for 10 CME events. We find that the low ionization state plasmas in CMEs observed by UVCS show small covering factors. This result shows that the high ionization state ICME plasmas observed by the ACE results from a small filling factor of cool plasma. We also find that the low ionization state plasma volumes in faster CMEs are smaller than in slower CMEs. Most slow CMEs in this analysis are associated with a prominence eruption, while the faster CMEs are associated with X-class flares.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.327-331
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• 2004

A simple HPLC method with ultraviolet detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation with trichloroacetic acid, chromatographic separation of ciprofloxacin in plasma was achieved at $50^{\circ}C$ with a $C_{18}$ column and methanol-phosphate mixture (pH 2.5), as mobile phase. Quantitative determination was performed by ultraviolet detection at 278 nm. The method was specific and validated with a limit of quantification of 100 ng/ml. The intra- and inter-day coefficients of variation were between 1.67% and 10.55% and accuracy between 92.01 % and 106.09%. The method has been successfully applied in a bioavailability study of 250 mg ciprofloxacin hydrochloride tablet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.569-570
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• 2021

Hydroponic cultivation is of considerable interest to the production of high-quality green plants. However, establishing the planting operating systems in hydroponic cultivation may result in chronic problems, such as the reproduction of harmful bacteria throughout the circulating culture fluid. Extensive research has been conducted on using an ultraviolet sterilization system to prevent culture fluid contamination. In this study, the proposed module, using UV-C LEDs that emit wavelengths between 270 and 285 nm, was designed along with a sensor and controller. The module was set to emit 300, 500, and 700 mW, for different culture fluid flow rates, to investigate its capacity to eliminate Escherichia coli, Clavibacter michiganensis, Pseudomonas cichorii, and Fusarium oxysporum.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.30-38
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• 1995

Anthracnose fungi associated with soybean (Glycine max), small red bean (Vigna angularis), and green bean (Phaseolus radiatus var. aurea) were compared with respect to cultural characteristics, morphological aspects, and pathogenicity. From the legumes, four different species of Colletotrichum were identified based on their morphological characters : C. truncatum, C. destructivum, C. trifolii and C. gloeosporioides. Colonies of Colletotrichum spp.on culture media varied in colour and growth habits depending upon the media and isolates. In general, formation of conidia, setae, and perithecia on water agar leaf medium was better than that on potato dextrose agar medium under near ultraviolet light. In cross inoculation tests, isolates of C. truncatum, c. destructivum, C. trifolii and C. gloeosporioides could infect soybean, small red bean, and green bean at different growth stages. There were some differences in pathogenicity or susceptibility depending on crops tested. C. truncatum was the most virulent and major pathogenic species among the four species.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.68.1-68.1
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• 2014

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual channel imaging spectrograph (S-channel 900-1150 ${\AA}$, L-channel 1350-1710 ${\AA}$, and ${\lambda}/{\Delta}{\lambda}$ ~ 550 for both channels) with large image fields of view (S-channel $4.0^{\circ}{\times}4.6^{\prime}$, L-channel $7.5^{\circ}{\times}4.3^{\prime}$, and angular resolution ~ $5-10^{\prime}$) optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) were made in two campaigns during its perihelion approach between May 8 and 15, 2004. Based on the scanning mode observations in the wavelength band of 1400-1700 ${\AA}$, we have constructed an image of the comet with an angular size of $5^{\circ}{\times}5^{\circ}$, which corresponds to the central coma region. Several important fluorescence emission lines were detected including S I multiplets at 1429 and 1479 ${\AA}$, C I multiplets at 1561 and 1657 ${\AA}$, and the CO $A^1{\Pi}-X^1{\Sigma}^+$ Fourth Positive system; we have estimated the production rates of the corresponding species from the fluxes of these emission lines. The estimated production rate of CO was $Q_{CO}=(2.65{\pm}0.63){\times}10^{28}s^{-1}$, which is 6.2-7.4% of the water production rate and is consistent with earlier predictions. The average carbon production rate was estimated to be $Q_C={\sim}1.59{\times}10^{28}s^{-1}$, which is ~60% of the CO production rate. However, the observed carbon profile was steeper than that predicted using the two-component Haser model in the inner coma region, while it was consistent with the model in the outer region. The average sulfur production rate was $Q_S=(4.03{\pm}1.03){\times}10^{27}s^{-1}$, which corresponds to ~1% of the water production rate.