• Membrane and Water Treatment
• /
• 제10권3호
• /
• pp.223-229
• /
• 2019

Titania modified by 2-ethylimidazole (2-EI) (denoted as $2-EI-TiO_2$) demonstrated visible light photocatalytic activity for the degradation of organic compounds. $2-EI-TiO_2$ was a bright brown powder that exhibited similar crystallinity and morphology with the control $TiO_2$. A diffuse reflectance spectrum indicated that $2-EI-TiO_2$ absorbs visible light of all wavelengths. X-ray photoelectron spectroscopy (XPS) confirmed the cationic state of nitrogen species (e.g. Ti-O-N) on the surface of $2-EI-TiO_2$. Visible light-illuminated $2-EI-TiO_2$ degraded $10{\mu}M$ 4-chlorophenol (4-CP) by approximately 85% in 4 h. The photochemical activity of $2-EI-TiO_2$ was selective in targeting the organic compound. The repeated use of $2-EI-TiO_2$ decreased the photocatalytic activity for the 4-CP degradation. Experiments using radical scavengers and oxidant probes revealed that the oxidation by photogenerated holes is responsible for the degradation of organic compounds by illuminated $2-EI-TiO_2$ and the role of $^{\bullet}OH$ is negligible.

• 한국광학회지
• /
• 제19권4호
• /
• pp.294-301
• /
• 2008

콜레스테릭 액정 컬러 필터의 광학적 특성 분석을 위한 모델링 및 시뮬레이션을 수행하였다. Berreman $4{\times}4$ 행렬법을 사용하여 입사각도별 콜레스테릭 액정 컬러 필터의 반사 스펙트럼을 계산하였고, 이를 광선 추적법에 기초한 조명설계 소프트웨어인 LightTools의 사용자 정의 코팅 파라미터로 입력하였다. LightTools를 이용하여 평면 투과형 콜레스테릭 액정 컬러 필터의 시야각에 따른 색변화를 시뮬레이션 하였다. 5도 간격 이하의 입사각도별 반사 스펙트럼을 LightTools의 사용자 정의 코팅 파라미터로 사용하였을 때, Berreman $4{\times}4$ 행렬법의 결과와 부합하는 결과를 얻을 수 있었다. 또한 반구형 패턴을 갖고 있는 반사형 콜레스테릭 액정 컬러 필터의 시야각에 따른 색변화를 시뮬레이션 하였는데, 본 논문의 시뮬레이션 방법을 비 평면형 구조에도 적용할 수 있음을 확인하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제24권4호
• /
• pp.69-87
• /
• 2018

Purpose: This study has been started with the awareness that light and color are the main visual sensors of the multi-sensory stimulation environment to achieve the therapeutic environment for demented elderly. The purpose of this study therefore is for clarifying the application characteristics of therapeutic light and color for dementia care facilities. Methods: Internal and external literature reviews have been conducted for the investigation into a)disorders and visual system in demented elderly, b)therapeutic effects of light and color, c)heliotherapy, light therapy and color therapy to deduce the therapeutic characteristics of light and color for demented elderly, and finally into d)the application characteristics of it for dementia care facilities. Results: The application characteristics of the therapeutic light and color for dementia care facilities are classified into both qualitative and quantitative characteristics. Qualitative application characteristics of light represented using of daylight, using of lighting approximate to daylight, expansion of iluminance level, equality in iluminance Level, reduction of shadow, and as well as exclusion of blare. Quantitative application characteristics of it represented iluminance level, color temperature and color rendering index prescribed in international lighting standards. Qualitative application characteristics of color represented non-monochromatic color, color contrast, long wavelength of yellow-red colors, exclusion of short wavelength of blue colors and patterns, and as well as different colors for idenfication. Quantitative application characteristics of it represented kontrast(K) prescribed in DIN32975:2009 and light reflectance value(LRV) prescribed in BS8300:2009. Implications: To form dementia care facilities as therapeutic environment both qualitative and quantitative application characteristics of therapeutic light and color in dementia care facilities are needed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1649-1651
• /
• 2008

A novel configured S-IPS LCD has been developed introducing a new compensation film with an anti-reflective layer. This new technology provides wide viewing characteristics as well as excellent visibility under bright indoor lighting or natural lighting.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.966-969
• /
• 2006

An optical model based on the optical thin-film theory is derived to calculate the output radiance of small molecules organic light-emitting diodes (OLEDs). We have designed the high efficiency OLEDs using the reflectance phase control of dielectric layers. It is found that OLED with a single $TiO_2$ dielectric layer is a good candidate to enhance the outcoupling efficiency and increase the color purity.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
• /
• pp.91-94
• /
• 2003

In this paper, we present a simple framework to measure BRDF(Bidirectional Reflectance Distribution Function) values of objects and to render them using the values more realistically. There are lots of BRDF measurement methods, but the methods have been separated from the effective rendering of the values. Therefore, we suggest the framework which includes the BRDF measurement methods of objects and the effective rendering methods of the measured BRDF data. Before measuring the BRDFs, we do light sources analysis, camera calibration and display device characterization. After measuring them, we apply them to the characterized display device for rendering effectively and realistically.

• Bulletin of the Korean Chemical Society
• /
• 제12권5호
• /
• pp.477-483
• /
• 1991

In the three-parameter ellipsometry (TPE), also known as reflectance-ellipsometry, the ellipsometric measurements, ${\Psi} and {\Delta}$, are combined with the reflectometric measurement, R, to determine the optical parameters and the thickness of a light-absorbing thin film. The constant ${\Psi}, {\Delta}$ and R surfaces are analyzed graphically to understand the nature of the TPE solutions. A sensitivityanalysis is shown to be useful not only for identifying the film properties which affect most the TPE measurements, but also for estimating errors in film properties arising from the uncertainties in measurements.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.374.2-374.2
• /
• 2016

Volatile organic compounds (VOCs) in the atmosphere are harmful materials which influence indoor air environment and human health. Titanium dioxide ($TiO_2$) is photocatalyst extensively used in degradation of organic compound. To improve the photocatalytic activity in the visible light region, doping with non-metals element or loading noble metals on the surface of $TiO_2$ is generally proposed. In this study, N- doped $TiO_2$ having photocatalytic activity in visible light region was attached noble metal such as Pt, Ag, Pd, Au by coupling method. Catalytic activities of Noble metal coupled $N-TiO_2$ powders were evaluated by the improvement of their photocatalytic activities and the degradation of VOC gas. A UV-Vis spectrophotometer was used to measure the diffuse reflectance spectra of coupled $N-TiO_2$ sample. The photocatlytic activities of as prepared samples were characterized by the decoloration of aqueous MB solution under Xenon light source (UV and visible light). To measure of decomposition VOCs, ethylbenzene was selected for target VOC material and the concentration was monitored under UVLED irradiation in a closed chamber system. Adjusting the initial concentration of 10~12 ppm, to evaluate the removal characteristics by using the coupled $N-TiO_2$.

• 한국정밀공학회지
• /
• 제16권7호
• /
• pp.40-50
• /
• 1999

Recently, a laser displacement sensor is widely used for the manufacturing automation. The sensor is generally composed of a diode laser and a light receiving device. The diode laser emits a laser beam and the receiving device detects the light reflected from the measured object. The object position is obtained based upon triangulation method. As a light receiving device, a PSD is usually utilized since its structure is very simple and rugged and has a high accuracy. Although the theoretical relationship for this sensor had been developed, the characteristics of the sensor have not been much experimentally studied. In this paper, several experimental results will presented. The measurement accuracy is affected by the surface conditions such as the reflectance characteristics, the angle of the object's surface and the laser intensity. In addition, it is found that the PSD and the signal processing circuit have nonlinearities and showed that those nonlinearities can be reduced by controlling the emitting laser intensity.

• Rapid Communication in Photoscience
• /
• 제1권1호
• /
• pp.13-15
• /
• 2012

New porous $TiO_2$ nanostructures with shapes of pearl and rice were synthesized by hydrothermal treatment of $TiO_2$-liposome nanocomposites in acid and base solutions, respectively, as identified by scanning electron microscopy (SEM), transmission electron microscopy (TEM) images and large Brunauer-Emmett-Teller (BET) surface areas. The x-ray diffraction (XRD) patterns and selected area electron diffraction proved them to be well-defined anatase crystals. Their UV-visible reflectance absorption spectra were observed to have low band gap energy (3.03 and 3.07 eV, respectively), exhibiting surface absorption band in the visible range from 400 to 600 nm. The degradation of methylene blue (MB) over the $TiO_2$ nanostructures was observed upon visible-light irradiation, which was found to be very efficient as compared with any other conventional visible-light responsive $TiO_2$ nanostructures.