• Journal of Ginseng Research
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• v.25 no.2
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• pp.82-88
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• 2001

This study was carried out to investigate a point of difference between normal and inferior Korean red ginseng (Naeback red ginseng = red ginseng with white part of clear boundary in phloem and/or xylem of ginseng body, saengnaeback red ginseng red ginseng with white part of indistinct boundary). White part with clear or indistinct boundary in center of ginseng body was observed in inferior red ginseng (naeback and saengnaeback red ginseng), and the differences in the internal color intensity was also found with naked eye. In hunter color values of normal and inferior parts of red ginseng in accordance with particle size, L value was increased with a diminishment in particle size, while a and b value were decreased. Absorbance at visible spectrum did not differ from water and 70% ethanol extract from normal and inferior parts of red ginseng, but absorbance in UV spectrum of extract from naeback part showed higher than those of normal and saengnaeback part. In comparison of intrastructure by electron microscope, the horizontal and vertical section of cortex and pith layer from normal part showed the very dense state, but small holes were found in naeback part of red ginseng by naked eye and electron microscope. The specific surface area of normal, naeback and saengnaeback part appeared 3.02, 3.33 and 6.55 ㎡/g, respectively. From above results, we consider saengnaeback red ginseng is red ginseng in the intermediate process which normal red ginseng changes to naeback red ginseng.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.52-55
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• 1996

The spectra of whole blood EDTA samples from two people were generated using a CARY 5E (UV-VIS-NIR) spectrophotometer from 400 to 1000nm which contain visible and NIR region. Only the data between 400 and 800nm were used to analyze the components of blood. Using the same spectrophotometer, the spectra of Water, normal saline, plasma were generated These spectra were subtracted from each blood sample, and then the first derivative of each of the subtracted data was taken to minimize baseline variations and indicated the wavelength-shift of peak and valley. Normalization and division between two blood samples were used to correlate the quantity ratio of specific components with feature of spectra. Samples were controlled at $30^{\circ}C,\;37^{\circ}C$, ambient temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1363-1368
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• 2008

The extraction and quantitative analysis conditions for astaxanthin from Haematococcus pluvialis, and the structural characteristics of H. pluvialis extract, H. pluvialis hydrolysate and synthetic astaxanthin were investigated using UV/visible and FT-IR spectrometers. Astaxanthin was dissolved in methanol, and then treated to enhance the solubility by sonication for 45 min. With sonication pretreatment, the solubility of astaxanthin increased up to 1.5 times compared to that without sonication. The extracts were hydrolyzed by cholesterol esterase for the analysis of H. pluvialis extract containing astaxanthin ester. A HPLC method using reverse phase C18 column with methanol-water (95:5, v/v) as mobile phase was developed to analyze astaxanthin. After hydrolysis, the absorption spectrum of H. pluvialis hydrolysat was changed to similar pattern to synthetic astaxanthin, confirming the extraction and analysis condition of astaxanthin from H. pluvialis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.6
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• pp.418-424
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• 2000

Pure $TiO_2$and 10 mol % Pb-doped $TiO_2(Pb_xTi_{1-x}O_2$(x = 0.1)) powder and thin films have been prepared by the sol-gel method. Titanium isopropoxide and ethanol are used for pure $TiO_2$, lead acetate trihydrate and titanium triisopropoxide monoacethylacetonate are used for Pb-doped $TiO_2$, respectively. Films are coated on p-type Si(100) wafer and ITO glass substrates by the sol-gel spin-coating method. The powder and multi-coated films are annealed at different temperature (400~$800^{\circ}C$) for phase formation and crystallization. TGA/DTA, XRD analysis, SEM and UV-visible transmission spectroscopy have been used to study the characteristics of the powder and films. XRD results show that the films are polycrystalline, anatase type and oriented predominantly to the A(101) plane. A slight shift in the d-spacing for the Pb-doped film indicates the incorporation of the Pb into $TiO_2$lattice. A shift of the absorption wavelength in the transmission spectrum towards longer wavelength has been observed about $Pb_xT_{1-x}O_2$(x = 0.1) thin film, which indicates a decrease in the bandgap of $TiO_2$upon Pb-doping.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.63-66
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• 2004

Transparent MgO thin films were deposited on glass substrates by electron beam evaporation of MgO (99.99%) under $O_2$ atmosphere at 150-250 $^{\circ}C$. These films were characterized for their useful properties such as thickness, transmission, and refractive index using ultraviolet / visible (UV/VIS) spectrophotometer, scanning electron microscopy (SEM), and Spectroscopic Ellipsometry. The thickness of MgO films were measured by alpha step instrument and found to be 600 nm to 1000 nm and are meeting the stoichiometry. The transmission spectrum of these films shows transmittance values ${\sim}$92%..

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1298-1300
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• 1994

An ability of $NO_2$ gas detection has been investigated using dilithium phthalocyanine($Li_2Pc$) Langmuir-Blodgett (LB) films. It is a well-known gas sensitive material and has been manufactured under a surface pressure of 30mN/m. A status of deposited films was confirmed by UV-visible absorption spectrum, ellipsometry measurements and current-voltage characteristics. Gas-detection characteristics of the films were studied through an electrical conductivity, response time, recovery time, and reproducibility under 200 ppm of $NO_2$ gases.

• Macromolecular Research
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• v.15 no.6
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• pp.575-580
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• 2007

Water-soluble, chiral conducting, poly(diphenylamine) (PDPA) nanocomposites were synthesized by chemical oxidative polymerization of diphenylamine in the presence of poly(acrylic acid) (PAA) as a template and camphor sulphonic acid (CSA) as the chiral inductor, Composites were formed as stable aqueous dispersions under different experimental conditions, such as DPA to PAA molar ratios, PAA molecular weight, etc. Circular dichroism(CD) spectra of the composites indicated the induction of chirality to PDPA. Compared to simple chiral PANI, the PDPA/PAA/CSA nanocomposites showed a different Cotton effect. The appearance of a CD band in the composite was complimentary to the bisignate, exciton-coupled band in the UV-Visible spectrum. FTIR spectra indicated the intimate mixing of PDPA and PAA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.56-58
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• 2000

We have synthesized the new blue electroluminescent material, Bis(3-N-ethylcarbazolyl)cyanoisophthalidene(BECCIP), and characterized its properties by UV/visible absorption, photoluminescent(PL) and electroluminecent(EL) spectrum. This material is well vacuum-deposited for thin film and has dear surfaced thin film property. The BECCIP shows blue PL and EL spectra at around at 485nm.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.193-198
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• 1999

Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of fatty acid. The displacement current was generated from monolayers on the water surface by monolayer compression and expansion. Displacement current was generated when the area per molecule was about $130{\AA}^2$. MDCs were investigated in connection with monolayer compression cycles. It was found that the current pulses were generated over the entire range of molecular area, and the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. We investigated the change in absorption spectra of the fatty acid(8A5H) monolayer LB film due to cis-trans photoisomerization. It was found that the absorption spectrum of the 8A5H LB film was induce to photoisomerization by alternate irradiation with UV and visible light irradiation.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1333-1335
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• 1997

We have made disperse diazo black D(DBD) thin films using Langmuir-Blodgett(LB) and vacuum-evaporation technique. Physical and optical properties of the films were investigated. Solution was made with a concentration of $10^{-3}mol/{\ell}$ using chloroform. Moving wall apparatus, (NL-LB140S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied UV/visible absorbance spectra and morphology of surface using atomic force microscopy(AFM). Vacuum-evaporated DB D thin films were made at a pressure of $10^{-5}$ torr. The absorption peaks were observed at 200 and 400 nm in the LB films and vacuum-deposited films. We have also studied photoluminescence spectrum of the DBD films.