Since airborne fungi have been known to aggravate indoor air quality, studies on developing anti-fungal filters increase recently. In this study, silver (Ag) nanoparticle was selected as anti-fungal agent. HEPA filter was coated with silver nanoparticles which were generated via spark discharge system operating at atmospheric pressure and temperature. The anti-fungal effect of the Ag-filter was evaluated with the conventional culture assay. When the number of Ag nano particle per a fungal particle in the filter was 1.91X106, the fungicidal efficiency was higher than 99%. As another anti-fungal test, ATP bioluminiscence detection method was also carried out and the results were correlated with those of the culture assay.

Quantum dots(QDs) with their tunable luminescence properties are uniquely suited for use as lumophores in light emitting device. We investigate the microstructural effect on the electroluminescence(EL). Here we report the use of inorganic semiconductors as robust charge transport layers, and demonstrate devices with light emission. We chose mechanically smooth and compositionally amorphous films to prevent electrical shorts. We grew semiconducting oxide films with low free-carrier concentrations to minimize quenching of the QD EL. The hole transport layer(HTL) and electron transport layer(ETL) were chosen to have carrier concentrations and energy-band offsets similar to the QDs so that electron and hole injection into the QD layer was balanced. For the ETL and the HTL, we selected a 40-nm-thick ZnSnOx with a resistivity of 10Ω·cm, which show bright and uniform emission at a 10 V applied bias. Light emitting uniformity was improved by reducing the rpm of QD spin coating.At a QD concentration of 15.0 mg/mL, we observed bright and uniform electroluminescence at a 12 V applied bias. The significant decrease in QD luminescence can be attributed to the non-uniform QD layers. This suggests that we should control the interface between QD layers and charge transport layers to improve the electroluminescence.

본 연구에서는 전하 조절층을 이용하여 녹색 인광 유기발광다이오드의 효율의 향상을 나타냈다. 양극성의 4,4,N,N'-dicarbazolebiphenyl (CBP)를 호스트와 전하 조절층으로 사용하여 발광층 내에서 전하의 이동을 원활하게 할 수 있다. 게다가 전하 조절층의 삽입으로 엑시톤을 효과적으로 발광층 내에 제한하여, 삼중항-삼중항 소멸 현상을 억제할 수 있음을 확인하였다. 발광층의 전체 두께는 유지하고, 전하 조절층의 변화를 준 다섯 개의 소자를 제작하여 최적화된 전하 조절층의 두께를 이용한 Device D는 외부 양자 효율 16.22%와 휘도 효율 55.76 cd/A의 성능을 보였다.

The quantum dots (QD) have unique electrical and optical properties due to quantum dot confinement effect. The optical properties of QDs are decided by various synthesis conditions. In a prior QDs study, a study on the QDs size with synthesis condition such as synthesis time and temperature is being extensively researched. However, the research on QDs size with composition ratio has hitherto received scant attention. In order to evaluate the ratio dependence of CdSe crystal, synthesis ratio of Se precursor is changed from 16.7 mol%Se to 44 mol%Se. As the increasing Se ratio, the band gap was increased. This is caused by red shift of emission. We confirmed optical property of CdSe QDs with composition ratio.

In this study, we investigated the applicability of the photostimulated luminescence(PSL), thermoluminescence( TL) and electron spin resonance(ESR) methods for various foods which are not allowed to be irradiated in Korea. All 15 foods including sesame, almond, peanut, cocoa powder etc. were analyzed. Samples were irradiated at 1~10 kGy using a 60Co gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative(lower than 700). The photon counts irradiated(1 kGy) dried shrimp, roasted peanut and seasoned peanut showed positive(higher than 5,000) and the other samples were negative or intermediate(> 700 and < 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal(single-line) intensity of irradiated foods was higher than non-irradiated foods. In particular, the specific ESR signals of irradiation-induced crystalline sugar, cellulose and bone radical were detected in dried plum, raisin, dried cherry, mango(dried, frozen), rambutan, cocoa(powder), cinnamon, parsley, carrot, broccoli, dried arrow squid, dried pollack and dried shrimp. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods because TL method is not able to detect the irradiated foods rarely composed of minerals. ESR is also a difficult method to detect the changes of ESR signal patterns of food. It is concluded that TL analysis or ESR assay is suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

폐쇄형 묘생산 시스템에서 청색LED, 적색LED, 백색형광등을 인공광원으로 이용한 가운데 파프리카의 육묘시 생장 특성과 정식 후 생장 및 초기 수량을 분석하고자 본 연구가 수행되었다. 폐쇄형 시스템에서 파프리카 육묘용 환경조건은 광주기 16/8h, 평균 PPF 204μmol·m-2·s-1, 기온 26/20℃, 상대습도 70%이었다. 육묘 후 21일째에 백색형광등과 LED 하에서 생장된 파프리카 묘의 엽장, 엽폭, 엽면적 등 잎 관련지표뿐만 아니라 지상부 생체중과 건물중, 엽록소함량 등이 자연광 처리구에 비해서 크게 나타났다. 청색 LED, 적색LED 및 자연광 처리구에서의 엽면적은 대조구인 형광등 처리구와 비교할 때 각각 63%, 63%, 28%에 해당하였다. 또한 청색LED, 적색LED 및 자연광 처리구의 지상부 건물중은 각각 대조구의 64%, 50%, 22%로 나타났다. 정식 후 18일째에 엽수는 대조구에서 44매로 가장 크게 나타났다. 적색LED, 청색LED 및 자연광 처리구의 엽수는 대조구에 비해서 각각 86%, 81%, 48%로서 정식 시기와 비교할 때 엽수의 차이가 줄어들었다. 정식 후 114일째에 초장은 청색LED와 적색LED 처리구에서 상대적으로 작게 나타났다. 이러한 결과는 단색LED 하에서 육묘된 파프리카의 줄기 신장이 정식 후에 억제된 것으로 판단된다. 초기 4주 동안 수확된 파프리카는 청색LED 3.5개/plant, 적색LED 3.3개/plant, 자연광 1.0개/plant으로서 대조구 2.2개/plant에 비해서 각각 159%, 150%, 45%로 나타났다. 초기수량은 적색LED 453g/plant, 청색LED 403g/plant, 자연광 101g/plant으로서 대조구 273g/plant와 비교할 때 각각 166%, 148%, 37%로 나타났다. 한편 적색LED 처리구에서의 평균 중량은 136g으로서 다른 처리구와 비교할 때 상대적으로 큰 과실이 생산되었다. 한편 정식 후 온실에서의 재배기간이 길어짐에 따라 인공광 처리구와 자연광 처리구에서 수량 차이가 없었다. 이러한 결과를 종합하면 LED 또는 형광등을 인공광원으로 이용한 조건에서 육묘된 파프리카의 정식 후 초기 생육이 양호하였으며, 초기 수확이 자연광 처리구에 비해서 1주 정도 빠르게 이루어졌음을 알 수 있다. 따라서 LED 또는 형광등과 같은 인공광원이 파프리카 육묘에 이용될 경우 묘소질의 향상, 조기 수확 및 초기 수량의 증대가 기대된다.

Peri-implantitis (PI) is bacteria-induced inflammatory condition which affects the alveolar bone and soft tissue around implants and may result in the loss of supporting bone. Attenuation of the P. gingivalis lipopolysaccharide (LPS)-induced inflammatory response can be a new therapeutic approach in the treatment of PI. This study was conducted to evaluate the anti-inflammatory effect of 635-nm light-emitting diode (LED) irradiation over MG63 osteoblast-like cell. Scratch was made on MG63 cells with or without LPS, then 635-nm irradiated. The expression of the cyclooxygenase-2 (COX-2) proteins was evaluated with western blot. The production of the prostaglandin E2 (PGE2) and expression of the receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) was measured with enzyme-linked immunoassay, and the cytokine profile was evaluated with the human inflammation antibody array. Wound closure effect presented in the cells treated with LPS was observed more significantly in the cells with 635-nm irradiation than the cells without irradiation. The 635-nm irradiaiton reduced LPS-induced expression of the COX-2 and production of the PGE2. Also, 635-nm irradiation affect the expression of RANKL, OPG, and proinflammatory cytokines. These results indicate that 635-nm irradiation could reduce the alveolar bone resorption induced by LPS stimulation through the inhibition of COX-2 expression and PGE2 production, the suppression of proinflammatory cytokine, and the modulation of RANKL/OPG balance in MG63 cells.

YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of . When the calcination temperatures were larger than , however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and to the spray solution was effective to prepare a spherical and dense structured YAG particles.

Red phosphors Ca1-1.5xWO4:Eux3+ were synthesized with different concentrations of Eu3+ ions by using a solid-statereaction method. The crystal structure of the red phosphors was found to be a tetragonal system. X-ray diffraction (XRD) resultsshowed the (112) main diffraction peak centered at 2θ=28.71o, and the size of crystalline particles exhibited an overalldecreasing tendency according to the concentration of Eu3+ ions. The excitation spectra of all the phosphors were composedof a broad band centered at 275nm in the range of 230-310nm due to O2−→W6+ and a narrow band having a peak at 307nmcaused by O2−→Eu3+. Also, the excitation spectrum presents several strong lines in the range of 305-420nm, which areassigned to the 4f-4f transitions of the Eu3+ ion. In the case of the emission spectrum, all the phosphor powders, irrespectiveof Eu3+ ion concentration, indicated an orange emission peak at 594nm and a strong red emission spectrum centered at 615nm,with two weak lines at 648 and 700nm. The highest red emission intensity occurred at x=0.10mol of Eu3+ ion concentrationwith an asymmetry ratio of 12.5. Especially, the presence of Eu3+ in the Ca1-1.5xWO4:Eux3+ shows very effective use of excitationenergy in the range of 305-420nm, and finally yields a strong emission of red light.

Red phosphors of Gd1-xAl3(BO3)4:Eux3+ were synthesized by using the solid-state reaction method. The phasestructure and morphology of the phosphors were measured using X-ray diffraction (XRD) and field emission-scanning electronmicroscopy (FE-SEM), respectively. The optical properties of GdAl3(BO3)4:Eu3+ phosphors with concentrations of Eu3+ ions of0, 0.05, 0.10, 0.15, and 0.20mol were investigated at room temperature. The crystals were hexagonal with a rhombohedrallattice. The excitation spectra of all the phosphors, irrespective of the Eu3+ concentrations, were composed of a broad bandcentered at 265nm and a narrow band having peak at 274nm. As for the emission spectra, the peak wavelength was 613nmunder a 274nm ultraviolet excitation. The intensity ratio of the red emission transition (5D0→7F2) to orange (5D0→7F1) showsthat the Eu3+ ions occupy sites of no inversion symmetry in the host. In conclusion, the optimum doping concentration of Eu3+ions for preparing GdAl3(BO3)4:Eu3+ phosphors was found to be 0.15mol.

Red-emitting Eu3+-activated (Y0.95-xAlx)VO4 (0<x≤0.12) nanophosphors with the particle size of ~30nm and thehigh crystallinity have been successfully synthesized by a hydrothermal reaction. In the synthetic process, deionized water asa solvent and ethylene glycol as a capping agent were used. The crystalline phase, particle morphology, and thephotoluminescence properties of the excitation spectrum, emission intensity, color coordinates and decay time, of the prepared(Y0.95-xAlx)VO4:Eu3+ nanophosphors were compared with those of the YVO4:Eu3+. Under 147nm excitation, (Y0.95-xAlx)VO4nanophosphors showed strong red luminescence due to the 5D0-7F2 transition of Eu3+ at 619nm. The luminescence intensityof YVO4:Eu3+ enhanced with partial substitution of Al3+ for Y3+ and the maximum emission intensity was accomplished at theAl3+ content of 10mol%. By the addition of Al3+, decay time of the (Y,Al)VO4:Eu3+ nanophosphor was decreased in comparisonwith that of the YVO4:Eu3+ nanophosphor. Also, the substitution of Al3+ for Y3+ invited the improvement of color coordinatesdue to the increase of R/O ratio in emission intensity. For the formation of transparent layer, the red nanophosphors werefabricated to the paste with ethyl celluloses, anhydrous terpineol, ethanol and deionized water. By screen printing method, atransparent red phosphor layer was formed onto a glass substrate from the paste. The transparent red phosphor layer exhibitedthe red emission at 619nm under 147nm excitation and the transmittance of ~80% at 600nm.

1-D ZnO nanowires have been attractive for their peculiar properties and easy growth at relatively low temperature. The length, diameter, and density of ZnO nanowires were determined by the several synthetic parameters, such as PEI concentration, growth time, temperature, and zinc salt concentration. The ZnO nanowires were grown on the<001> oriented seed layer using the hydrothermal process with zinc nitrate and HMTA (hexamethylenetetramine) and their structure and optical properties were characterized. The morphology, length and diameter of the nanowires were strongly affected by the relative and/or absolute concentration of Zn2+ and OH-1 and the hydrothermal temperature. When the concentrations of the zinc nitrate HMTA were the same as 0.015 M, the length and diameter of the nanowires were 1.97μm and 0.07μm, respectively, and the aspect ratio was 28.1 with the preferred orientation along the<001> direction. XRD and TEM results showed a high crystallinity of the ZnO nanowires. Optical measurement revealed that ZnO nanowires emitted intensive stimulated UV at 376 nm without showing visible emission related to oxygen defects.

광섬유 직물 기반 스마트 의류가 국, 내외로 개발되고 있는 실정이며, 기존의 일반적인 광섬유는 직물화가 어렵고 내구성, 내수성이 결여되어 세탁 및 유지 관리의 한계로 인해 에칭된 광섬유사의 표면에 합성수지를 코팅 처리하는 '내수성 광섬유사 가공 기술'이 최근 개발 되었다. 본 연구에서는 제직 후 측광가공 된 유연 광섬유 직물을 대상으로 광섬유사 길이에 따른 특성과 광원 색채에 따른 발광 특성을 분석, 평가하여 디지털 컬러 의류의 적용 적합성을 파악하고자 한다. 이를 위하여 광섬유사 길이에 따른 총 4가지 유연 광섬유 직물시료를 제직하여, 이를 대상으로 광원 색채에 따른 유연 광섬유 직물의 휘도, 물리적 가시도, 지각적 가시도를 측정함으로써 발광특성을 분석하였다. 그 결과, 10cm인 유연 광섬유 직물과 녹색 광원을 사용한 경우가 최대가시거리 100m로 디지털 컬러 의류 즉, 안전보호 기능의 산악복 적용에 가장 적합한 발광효과를 보이는 것으로 나타났다. 그러므로 본 연구의 결과는 앞으로 유연 광섬유 직물 적용 의류 개발과 관련된 후속 연구의 자료로서 활용될 수 있을 것으로 기대된다.

Red-orange phosphors Gd1-xPO4:Eux3+ (x=0, 0.05, 0.10, 0.15, 0.20) were synthesized with changing theconcentration of Eu3+ ions using a solid-state reaction method. The crystal structures, surface morphology, and optical propertiesof the ceramic phosphors were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), andphotoluminescence (PL) spectrophotometry. The XRD results were in accordance with JCPDS (32-0386), and the crystalstructures of all the red-orange phosphors were found to be a monoclinic system. The SEM results showed that the size ofgrains increases and then decreases as the concentration of Eu3+ ionincreases. As for the PL properties, all of the ceramicphosphors, irrespective of Eu3+ ion concentration, had orange and red emissions peaks at 594nm and 613nm, respectively. Themaximum excitation and emission spectra were observed at 0.10mol of Eu3+ ion concentration, just like the grain size. Anorange color stronger than the red means that 5D0→7F1 (magnetic dipole transition) is dominant over the 5D0→7F2 (electricdipole transition), and Eu3+ is located at the center of the inversion symmetry. These properties contrasted with those of a redphosphor Y1-xPO4:Eux3+, which has a tetragonal system. Therefore, we confirm that the crystal structure of the host materialhas a major effect on the resulting color.

The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

New organic light-emitting diodes with structure of indium-tin-oxide[ITO]/N,N'-diphenyl-N, N'-bis-[4-(phenyl-m-tolvlamino)-phenyl]-biphenyl-4,4'-diamine[DNTPD]/1,1-bis-(di-4-poly-aminophenyl) cyclohexane[TAPC]/bis(10-hydroxy-benzo(h)quinolinato)beryllium[Bebq2]/Bebq2:iridium(III)bis(2-phenylquinoline-N,C2')acetylacetonate[(pq)2Ir(acac)]/ET-137[electron transport material from SFC Co]/LiF/Al using the selective doping of 5%-(pq)2Ir(acac) in a single Bebq2 host in the two wavelength (green, orange) emitter formation were proposed and characterized. In the experiments, with a 300Å-thick undoped emitter of Bebq2, two kinds of devices with the doped emitter thicknesses of 20Å and 40Å in the Bebq2:(pq)2Ir(acac) were fabricated. The device with a 20Å-thick doped emitter is referred to as "D-1" and the device with a 4Å-thick doped emitter is referred to as "D-2". Under an applied voltage of 9V, the luminance of D-1 and D-2 were 7780 cd/m2 and 6620 cd/m2, respectively. The electroluminescent spectrum of each fabricated device showed peak emissions at the same two wavelengths: 508 nm and 596 nm. However, the relative intensity of 596 nm to 508 nm at those wavelengths was higher in the D-2 than in the D-1. The D-1 and D-2 devices showed maximum current efficiencies of 5.2 cd/A and 6.0 cd/A, and color coordinates of (0.31, 0.50) and (0.37, 0.48) on the Commission Internationale de I'Eclairage[CIE] chart, respectively.

최근 IT 융합 기술이 글로벌 시장의 핵심 화두로 떠오르면서, 스마트 의류 분야에서도 '의류+서비스 제공(service provider)' 기능을 갖는 PSS형 제품 디자인에 대한 수요가 크게 증가하고 있다. 본 연구에서는PSS형 제품 디자인의 일환으로서 안전보호 기능의 산악복 용도에 적합한 발광특성을 지닌 유연 광섬유 기반 직물 디스플레이의 제직구성을 모색하고, 이를 적용한 산악복 모형 디자인을 제시하였다. 이를 위하여 제직 구성, 즉 직물조직과 광섬유 밀도가 다른 총 15개 광섬유 직물 디스플레이 시료를 제직하여, 이를 대상으로 각각의 휘도를 측정함으로써 발광특성을 분석하였다. 그 결과, '주자직 2:1', '주자직 3:1' 및 '능직 2:1', '능직 3:1'인 경우가 안전보호 기능을 위한 산악복으로서 적용이 가장 적합한 발광효과를 보이는 것으로 나타났다. 발광특성에 관한 분석 결과 및 최근 스포츠 패션 트렌드를 기초로 하여, 유연 광섬유 직물 디스플레이 적용 산악복 모형 디자인을 전개하였다.

Bi co-doped ZnS:Mn,Bi yellow phosphors for white light emitting diodes were prepared by the conventional solidstate reaction method. The optical and structural properties of ZnS:Mn,Bi phosphors were investigated by x-ray diffraction, scanning electro microscopy and photoluminescence. ZnS:Mn,Bi phosphors showed XRD patterns of hexagonal structure. The photoluminescence of ZnS:Mn,Bi phosphors showed spectra extending from 480 to 700 nm, peaking at 580 nm. The photoluminescence of 580 nm in the ZnS:Mn,Bi phosphors was associated with the 4T1 → 6A1 transition of the Mn2+ ions. The highest photoluminescent intensity of the phosphors under 405 nm and 450 nm excitation was obtained at Bi concentration of 7mol%. The optimum mixing conditions with epoxy and yellow phosphor for white light emitting diodes were observed in a ratio of epoxy:yellow phosphor of 1:3.5. The CIE chromaticity of the white LED at the 1:3.5 ratio was X = 0.3454 and Y = 0.2449.

Organic light emitting diode(OLED) has been developed fast from 1963 when electric light emitting phenomenon was discovered. PMOLED(passive matrix OLED) is producted earlier than AMOLED(active matrix OLED). PMOLED is mainly mounted at sub display, but AMOLED is mounted at main display. Nowadays AMOLED is expanded to PMP(portable multimedia players), navigation and TV market. Even thought OLED's market is opening to many applications, OLED's life is worried until now. If we know about OLED's real life, we need time to test so much time over 20,000hrs. Realistically, there is difficult to test such as long time with products from the information-technology sector having a short life cycle. In this paper, we study about OLED's accelerated test to reduce life test by current. We can design OLED's accelerated life model by the result of test. The model consists of design variables like ratio of light emitting, organic material structure, condition of aging, etc. In conclusion, this model can be applied to study about organic material, machine and manufacturing process etc, and also it's possible to develop a method of manufacturing process & materials, so we need to study on the subject of this paper continuously.