• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.962-967
• /
• 2011

Radiative properties of alumina particles which is the main element of the plume from booster and kick motor used for increasing thrust and insertion into the orbit is analyzed. In order to derive the wavelength integrated (i.e., gray) emissivity, emission term in radiative transfer equation is rearranged to be able to tie up with the parameters induced from fundamental particle scattering Mie theory. Result shows that derived gray emissivity with optical properties increases with temperature rising.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1075-1078
• /
• 2006

New iridium complex was synthesized and demonstrated a deep red light emission in organic light-emitting diodes (OLEDs). The maximum luminance of 8320 cd/m2 at 15 V and the luminance efficiency of 2.5 cd/A at 20 mA/cm2 were achieved. The peak wavelength of the electroluminescence was at 626 nm with the CIE coordinates of (0.69, 0.30), and the device also showed a stable color chromaticity with various voltages.

• YAKHAK HOEJI
• /
• v.37 no.3
• /
• pp.209-215
• /
• 1993

Basic drugs could be extracted as ion-paired complexes with Lumogallion, Superchrome Garnet Y and their alkyl derivatives from aqueous acid solution, and then determined fluoro-metrically after addition of aluminum ion. The analysis was carried out as follows; To a 1 ml portion of basic drugs (10$^{-9}$~2$\times$0$^{-8}$mole/ml), 1ml of 0.01w/v% fluorescent reagent solution, and 10ml of dichloroethane are added. The mixture is stirred for 1 minute. After standing for a few minutes, the dichloroethane layer is transfered to 1 ml of 0.1w/v% Al(NO$_{3}$)$_{3}$ ethanol solution. After mixing, and standing for 30 minutes at room temperature, the fluorescence intensity is measured with each maximum excitation and emission wavelength. The reagent blank is run through the whole procedure. From the degree of enhancement of fluorescence intensity, hexyl and dodecyl lumogallion and Superchrome Garnet Y were judged to be the useful one of fluorescent reagent for basic drugs analysis.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.153-154
• /
• 2000

Many bioactive photosensitizers have been isolated from plants and some of theses possess antiviral activities which, depend on UVA(320-400nm) and visible light. Many complex quinonoids have been isolated from plants and recently some of them, such as hypericin and hypocrellin, have been shown to possess light-dependent antiviral activities. these compounds only exert their desired biological activities in the presence of long wavelength ultra-violet UVA but these activities are also strongly influenced b chemical structure(Hudson et al, 1995). the importance of light in the use of certain medicinal plant extracts has been appreciated, if not understood, for centuries. Also, many seaweed extracts will effect photo(UVA, visible light) for algicidal activity. (omitted)

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.211-212
• /
• 2000

Organic electroluminescent devices (OELDs) have received a great deal of attention due to their potential application as full-color displays. Europium complexes are known as excellent red light-emitting materials for OELDs since they show intense photoluminescence at around 612 nm with a narrow spectral bandwidth. In this study, a novel europium complex, $Eu(TTA)_3(TPPO)$ was synthesized and its photoluminescent and electroluminescent characteristics were investigated with a device structure of ITO/TPD/$Eu(TTA)_3(TPPO)$/ $Alq_3$/Al, where sharp emission at the wavelength of 615 nm has been observed. Details on the electrical properties of these structures was also discussed.

• Electrical & Electronic Materials
• /
• v.8 no.2
• /
• pp.129-135
• /
• 1995

SiO thin films are deposited by evaporator the refractive index of wave length, photon energy and the absorptive rate of these films are measured by spectroscopic ellipsometer. It is derived the absorptive rate and permitivity of SiO thin films from the equations that calculating the refractive index. And the result show good agreement with the calculated values and experimental values. As a result, the wave length of light is increased in the condition that the angle of incidence is fixed on SiO thin film, the basic absorption and the absorption impurities are found in the low wave length (below 450 nm in this study) and the reflective absorption and conductive absorption is increased by the form of exponential function over the low wavelength. The absorptive rate is increased by increased the angle of incidence and thickness of SiO film for the insulating layer. As the thickness of SiO film is increased, the value of complex permitivity is decreasing and as wave length of incidence is increased., the value of dielectric is linearly increasing.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2007.06a
• /
• pp.197-202
• /
• 2007

Most of seismic reflection prospecting assumes subsurface formation to be homogeneous media. These models are not capable of estimating small scale heterogeneity which is verified by well log data or drilling core. And those synthetic seismograms by homogeneous media are limited to explain various changes at field data. So we developed a inhomogeneous velocity model which can estimate inhomogeneity of background medium to implement numerical modeling from homogeneous medium and inhomogeneous medium on the model. Background medium using three autocorrelation functions in order to generate inhomogeneous velocity media was according to dominant wavelength of background medium and correlation length of random medium. And then we compared shot gathers. The results show that numerical modeling implemented at inhomogeneous medium depicts complex wave propagation of field data.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.5
• /
• pp.272-277
• /
• 2006

The present study is devoted to investigate numerically the optical characteristics of multi-layer thin film structures such as $Si/SiO_2\;and\;Ge/Si/SiO_2$ by using the characteristics transmission matrix method. The reflectivity and the absorptivity rate for thin film structures are estimated for different incident angles of rays and various film thicknesses. In addition, the influence of wavelength on optical characteristics related to complex refractive index is examined. It is found that such wave-like characteristics are observed in predicting reflectivities and depends mainly on film thickness. Moreover, the present study predicts the film thickness for ignoring wave interference effects, and it also discusses the fundamental physics behind optical and energy absorption characteristics appearing in multi-layer thin film structures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.578-581
• /
• 1999

Dot pattern print methods composed of a diffusion film and two prism sheets, have been generally used for backlighting systems of LCDs. However, this methods require complex structures and show high power consumption and optical loss. To improve these disadvantages of conventional backlight units, light guides using highly scattering optical transmissions (HSOT) polymer as scatters, have been introduced. In this study we analyzed multiple scattering effect in light guide by means of Monte carlo simulation based on Mie scattering theory and ray tracing method. As a result it was revealed that scattering intensity depends on the size of scatters. On the other hands, it was shown that scattering efficiency depends on the wavelength of fluorescent lamp as well as the size of scatters.

• Current Optics and Photonics
• /
• v.6 no.1
• /
• pp.10-14
• /
• 2022

Low-threshold optical bistability is essential for practical nonlinear optical applications. Many bistable optical devices based on high-quality-factor resonators have been proposed to reduce the threshold intensity. However, demonstrating high-quality-factor resonance requires complex fabrication techniques. In this work, we numerically demonstrate optical bistability with bound states in the continuum in a simple one-dimensional Si photonic crystal. The designed structure supports bound states in the continuum, producing an ultrahigh quality factor without tough fabrication conditions. The threshold intensity of the designed device is 150 MW/cm² at the optical communication wavelength. This scheme may lead to a new class of nonlinear photonics.