• 약학회지
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• 제54권1호
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• pp.13-21
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• 2010

The interaction of cadmium (II) ion with quercetin, qurecitrin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to flavonoid have been determined by UV-visible spectroscopy. 1:1 Cd(II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, is due to a ligand-tometal charge transfer. The optimal concentration of Cd(II)-flavonoid complexes showed that complexation reaction could be classified in the following way: 55.27 ${\mu}M$ catechin > 54.72 ${\mu}M$ quercetin > 53.52 ${\mu}M$ quercitrin at the chelating site level. These results suggest that Cd(II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.

• Journal of Biosystems Engineering
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• 제29권4호
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• pp.335-340
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• 2004

This study was conducted to evaluate the internal quality of Korean red ginseng using VIS/NIR transmittance spectra. To classify the internal qualities, partial least squares(PLS) regression was conducted. The main results are as follows: To develop the PLS model, several wave bands were divided and incorporated into the model. Among the bands, the wavelength range of 550-1,020nm, excluded noise signal, showed the best evaluation results. Effect of step size on the performance of quality evaluation showed optimal at 15 steps. In order to enhance the accuracy of quality evaluation, the abnormal spectrum shape was considered first and then the PLS model was applied. Among the 150 samples, 12 samples were evaluated by the spectrum shape. In this study, to develop the optimal PLS regression model, among the 150 samples, 138 samples was used with exception of 12 samples which could evaluate the spectrum shape. The result of quality evaluation was promising as SEC and correlation coefficient were 1.09 and 0.967, respectively, and SEP and correlation coefficient were 1.04 and 0.958, respectively.

• Current Optics and Photonics
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• 제5권5호
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• pp.554-561
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• 2021

Indocyanine green (ICG) is a cyanine dye that has been used in medical diagnostics based on fluorescence imaging, and in medical therapy based on the photothermal effect. It is important to systematically understand the photothermal effect and fluorescence characteristics of ICG simultaneously. By varying a number of conditions such as laser power density, laser irradiation wavelength, concentration of ICG solution, and exposure time of laser irradiation, the intensity properties of fluorescence and the temperature change induced by the photothermal effect are measured simultaneously using a charge-coupled-device camera and a thermal-imaging camera. The optimal conditions for maximizing the photothermal effect are determined, while maintaining a relatively long lifetime and high efficiency of the fluorescence for fluorescence imaging. When the concentration of ICG is approximately 50 ㎍/ml and the laser power density exceeds 1.5 W/cm², the fluorescence lifetime is the longest and the temperature induced by the photothermal effect rapidly increases, exceeding the critical temperature sufficient to damage human cells and tissues. The findings provide useful insight into the realization of effective photothermal therapy, while also specifying the site to be treated and enabling real-time treatment monitoring.

• 약학회지
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• 제46권6호
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• pp.392-397
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• 2002

A simple and sensitive high performance liquid chromatographic method to quantitate ursodeoxycholic acid in crude drug pharmaceuticals was investigated. Ursodeoxycholic acid react with 2-bromoacetyl-6-methoxynaphthalene (Br-AMN) in the presence of triethylamine to form highly fluorescent derivative. The derivatization procedure was performed at 7$0^{\circ}C$ and completed within 30 min. The optimal wavelength of the fluorescence detector are λ$_{ex}$=300 nm and λ$_{em}$ = 460 nm. The LOD of the ursodeoxycholic acid was 25 ng/mι based on the S/N =3, and the LOQ was 80 ng/mι based on S/N = 10. Crude drug pharmaceuticals pretreated by solid phase extraction (Sep-pak $C_{18}$ cartridge) which were shown very good separation and recovery values for the compound.d.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1497_1498
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• 2009

This paper presents the simulation of micro-lens arrays based on dry and wet etching technique. Code V (Optical Research Associates Ltd) simulation was performed to extract optimal design parameters of a Micro-Lens Array(MLA). Thickness of UV adhesive, wavelength of laser source, curvature, and shape of lens surface were chosen for the design parameters. The simulation results showed that focal length of a MLA decreased with the increase of UV adhesive thickness. And the focal length depended on shape of lens surface and length of laser source.

• 약학회지
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• 제53권5호
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• pp.235-240
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• 2009

The interaction of cadmium (II) ion with quercetin was investigated in aqueous solution at different pH. The quercetin/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd(II) ion with 54.72 ${\mu}M$ quercetin (A=1.00793) was formed in 0.2 M $NH_3-0.2$ M $NH_4Cl$ (pH 8.0) buffer solution. 1:1 Cd(II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with quercetin in buffer solution. These results suggest that Cd(II)-quercetin complex has the optimal condition of chelation in basic buffer solution.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.612-615
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• 2003

Maskless laser patterning process is developed using 3rd harmonic Diode Pumped Solid State Laser with near visible wavelength of 355 nm. Photo-sensitive curable polymer is irradiated by UV laser and developed using polymer solvent to obtain quasi-3D patterns. We performed basic experiments for the various process conditions such as laser power, writing speed, laser focus, and polymer optical property to gain the optimal conditions. Experimentally, the patterns of trapezoidal shape were manufactured into dimension of 8${\mu}{\textrm}{m}$ width and 5.4${\mu}{\textrm}{m}$ height. This process could be applied to fabricate a single mode waveguide without expensive mask projection method.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.983-987
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• 2004

We have studied electro-optic characteristics of reflective optically compensated splay (R-OCS) cell. The initial configuration of this cell is in splay form such that a mid director lies parallel to the substrate and around it hybrid structure is formed symmetrically so the optically compensation effect exists. Optimized optical configurations could be achieved by using a single polarizer, a quarter-wave film and a cell with quarter-wane retardation. The optimal cell retardation is 0.34 ${\mu}$m, allowing to have large cell gap. The cell provides high contrast ratio of 80:1 at normal direction and the region with contrast ratio over 5:1 covert up to 160$^{\circ}$ horizontally and vertically at all wavelength range.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.149-149
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• 2011

CdS films were deposited on glass substrates by R.F. magnetron sputtering method and the films were annealed at various substrate temperatures ranging from room temperature to $300^{\circ}C$. Structural properties of the films were studied by X-ray diffraction analysis. The structural parameters as crystallite size have been evaluated. The crystallite sizes were found to increase, and the X-ray diffraction patterns were seen to sharpen by increasing substrate temperatures. X-ray diffraction patterns of these films indicated that they contain both cubic (zincblende) and hexagonal (wurtzite) structures as a mixture. Optical properties of the films were measured at room temperature by using UV/VIS spectrometer in the wavelength range of 190 to 1100nm and optical absorption coefficients were calculated using these data. The energy gap of the films was found to decrease, and the band edge sharpness of the optical absorption was seen to oscillate by annealing. The results show that heat treatments under optimal annealing condition can provide significant improvements in the properties of CdS thin films.

• 한국레이저가공학회지
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• 제17권1호
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• pp.17-21
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• 2014

Head up display is in increasing demand for advanced devices in the modern luxury vehicles. It helps drivers focus on driving environment on the road. While HUD technology with LED has advanced, the brightness in daylight can be still an issue to be resolved. Laser light source is a possible solution to overcome the brightness problem and optimal optics design is required for the best performance. Sample design of optics is proposed and detail procedure of lens design evaluation is presented in this paper. The results were characterized by using a ray tracing method and qualitative analysis for spot and DEE is also presented. The overall error or image distortion remained in the target range of $25{\mu}m$ and the simulated image demonstrated possible use in the automotive applications.