• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.212-218
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• 2012

The optical properties of AZO thin films prepared by the RF mangnetron sputtering system was studied to research the dependance of chemical properties of substrate. The substrate was the SiOC film deposited by Inductively coupled plasma chemical vapor deposition with various gas flow rate of $O_2$ and Ar (DMDMOS). In accordance with the increase of Ar gas flow rates, the Si-O bond in the SiOC film increased and then progressed the amorphism. The roughness of AZO grown on SiOC film with high degree of amorphism decreased and then improved the flatness of surfaces. Moreover, the ultra violet emission with high intensity was spontaneously induced in the AZO film growed on SiOC film with high degree of amorphism.

• Korean Journal of Materials Research
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• v.12 no.9
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• pp.735-739
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• 2002

$(Y,Gd)BO_3$: Eu, $Zn_2$$SiO_4$ : Mn and $BaMgAl_{10}$ $O_{17}$ : Eu phosphors used in PDP were continuously irradiated by vacuum ultra violet generated from the penning gas (96%Ar+4%Xe) discharge and then the change of emitting intensity with time was investigated. The brightness of these phosphors decreased exponentially with VUV excitation time. The experimental data showed that the degradation rate increased in the order of $Zn_2$$SiO_4$ : Mn>(Y,Gd)$BO_3$: Eu>$BaMgAl_{10}$ $O_{17}$ : Eu phosphor. This different degradation property of phosphors was interpreted in terms of brightness saturation and stability against VUV irradiation. It was found that the degradation property of $(Y,Gd)BO_3$ : Eu red phosphor synthesized by ultrasonic thermal spray was superior to commercial phosphor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.15-20
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• 2014

Recently, LED (Light Emitting Diode) application research is studying by using a specific wavelength. LED plant factory produced a lot of green plants in a closed spaces, so it should be taken to guard against harmful microbes. Until today, a lot of studies for green plant production in plant factory is proceed but there were no study on harmful microbes in plant factory. Thus, the analysis on sterilization for harmful microbes in plant factory were experimented using UV (Ultra Violet) LED with 282nm of wavelength. As a results on sterilization of three harmful microbes, 50% of sterilization efficiency was achieved after 2.5 hours, 97% was achieved after 12 hours of UV LED irradiation, respectively.

• Journal of Surface Science and Engineering
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• v.50 no.6
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• pp.480-485
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• 2017

Soft mold imprinting method that uses nanostructured polymer mold was investigated for anti-reflection film fabrication. The nanostructured soft mold was polyethylene terephthalate(PET) irradiated by oxygen ion beams. The collisional energy transfer between oxygen ion and the polymer surface induced cross-linking and scission reactions, resulting in self-organized nanostructures with regular patterns of the wavenumber of $5{\mu}m^{-1}$. Post processes including ultra-violet curable resin coating and delamination fabricated anti-reflection films. The imprinted resin surface also showed the consistent wavenumber, $5{\mu}m^{-1}$. Pristine PET, oxygen ion beam treated PET, and imprinted replica sample showed total transmittance of 91.04, 93.25, and 93.57-93.88%, respectively.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3060-3063
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• 1999

We made a multi-layer conveyor sterilizing system using UV rays to prolong a storage period of dried marine products. The system is composed of 5 layer conveyor belt of 3 m long each, thus 15 m long in total. It is designed to radiate UV rays for 10 minutes the dried marine products, and can process 300 kg/hour. Eight UV lamps of 30 cm long and 15 W of power with 254 nm wave length are installed in parallel, 15 cm high above in each belt, and 40 lamps in total. The whole system is covered by 1 mm thick metal plates to block the UV rays except a front side which is covered with 5 mm thick plastic plates coated with UV protection film to survey inside of the system. A sterile ratio is about 99.97% with 10 minutes sterilization using this system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.8
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• pp.508-513
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• 2017

Ultraviolet (UV) photodetectors are used in various industries and fields of research, including optical communication, flame sensing, missile plume detection, astronomical studies, biological sensors, and environmental research. However, general UV detectors that employ Schottky junction diodes and p-n junctions have high fabrication cost and low quantum efficiency. In this study, we investigated the characteristics of materials used to manufacture UV photodetectors in a low-cost solution process that requires easy fabrication of flexible substrates. We fabricated p-type NiO and n-type ZnO substrates with wide band gap by the sol-gel method and compared the characteristics of substrates prepared under different spin-coating and heat-treatment conditions.

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.55-67
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• 1986

Inclusion complexation of tiaprofenic acid (TPA) with cyclodextrins $({\alpha}-,\;{\beta}-,\;{\gamma}-CyDs)$ in aqueous solution and in solid phase was investigated by solubility method, measurement of partition coefficient, ultra-violet, circular dichroism, infrared spectroscopies, powder X-ray diffractometry and differential scanning calorimetry. Investigations were made to prepare inclusion complexes of TPA with ${\beta}-CyD$ in solid powdered form by coprecipitation, freeze-drying, spray-drying and co-pulverization methods. The coprecipitation, freeze-drying and spray-drying methods were successful in obtaining inclusion complexes. The results showed that the latter two methods might be originally superior to the former in obtaining powdered inclusion completes. Especially, it was shown by powder X-ray diffractometry that spray-dried ${\beta}-CyD$ alone, TPA-spray-dried ${\beta}-CyD$ physical mixture, and spray-dried $TPA-{\beta}-CyD$ complex were amorphous. The dissolution behaviours of $TPA-{\beta}-CyD$ systems prepared by above four methods were compared with those of TPA alone and $TPA-{\beta}-CyD$ physical mixture, and the rates of dissolution of TPA in pH 1.2 buffer were greatly enhanced by inclusion complexation and copulverization.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.75-86
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• 2004

The objective of the research is to develop agricultural resue technologies of reclaiming the effluents from a municipal wastewater treatment plant and reusing for irrigated rice paddies. The Suwon wastewater treatment plant was selected for wastewater reuse tests. The control was the plots with groundwater irrigation (TR＃1), the treatment (TR＃2) using polluted stream water as it was, and three others using wastewater after treatment. Three levels of wastewater treatments were employed： the effluent from the wastewater treatment plant (TR＃3), sand filtering after treatment plant(TR＃4), and ultra-violet treatment after sand filtering (TR＃5). The randomized block method was applied to wastewater application to paddy rice with five treatments and six replica. The effects of various wastewater treatment levels on water quality, paddy soil, crop growth, yields, and the health hazards were investigated. The primary results indicate that cultivating rice with reclaimed wastewater irrigation did not cause a problem to adverse effects on crop growth and yields. Overall, wastewater could be used as a practical alternative measure for reclaimed wastewater irrigation. However, long-term monitoring is recommended on the effects on soil chemical characteristics and its related health concerns.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.4
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• pp.223-226
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• 2013

In this study, we investigated the electro-optical(EO) characteristic of fringe-field switching(FFS) mode cell by the two kinds of ultraviolet(UV) alignment method on the organic thin film(polyimide: PI). The suitable organic layersfor FFS cell and the aligning capabilities of nematic liquid crystal(NLC) using the in-situ photoalignment method were studied Disclination is observed after conventional photoalignment method for 1h, and in-situ photoalignment method for 1h. Monodomain alignment of the NLC can be observed via in-situ photoalignment method for 2h and 3h. It is considered that NLC alignment is due to photo-depolymerization of the polymer with oblique non-polarized UV irradiation on PI surface. An unstable V-T curve of UV-aligned FFS-LCD with conventional photoalignment method can be achieved. However, a stable V-T curve of UV-aligned FFS-LCD with in-situ photoalignment method(1h), and V-T curve of UV-aligned FFS-LCD with in-situphotoalignment method was much stable comparing with that of other UV-aligned FFS-LCD's. As a result, more stable EO performanceof UV-aligned FFS-LCD with in-situphotoalignment method for 3h is obtained than that of the other UV-aligned FFS-LCD's.

• Polymer(Korea)
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• v.29 no.5
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• pp.508-517
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• 2005

The thermal degradation behavior and reliability analysis were investigated using dynamic thermogravimetric analysis (TGA) and accelerated degradation test (ADT) to characterize the dynamic parameters related to thermal degradation of plastic meterials for household electric appliances. In addition, the weathering of the plastic were performed by ADT using Xenon uc, and the color difference of the samples after ADT were measured with Color Eye 3010 specoophotometer. he activation energy for thermal degradation of the samples increased with increasing the rate of weight loss. The Kim-Park method was found to be more effective analysis in describing thermal degradation of plastic meterials. Plastic materials were very sensitive to ultra-violet rays in faster degradation.