• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.286-290
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• 2012

Many diterpenoids from Siegesbeckia species (Compositae) and their anti-inflammatory actions have been examined. In this research, high-performance liquid chromatography-ultraviolet spectrophotometer (HPLC-UV) method was used to compare the quantitative level of kirenol (ent-pimarane-type diterpenoid) in the aerial parts of Korean S. glabrescens and S. pubescens and the Chinese Siegesbeckiae Herba. Fingerprints of the two HPLC chromatograms of Korean S. glabrescens and S. pubescens were similar, but considerably different from Chinese Siegesbeckiae Herba. The content of kirenol in S. pubescens ($16.51{\pm}0.10$ mg/ml dry weight as mean${\pm}$RSD) was higher than S. glabrescens ($13.48{\pm}0.12$ mg/g dry weight). These values were considerably higher than the Chinese Siegesbeckiae Herba ($1.55{\pm}0.74$ mg/g dry weight). Thin layer chromatography (TLC) analysis demonstrated the containing of kirenol in the three plant materials, but the presence of siegeskaurolic acid (entkaurane-type diterpenoid) only in the Chinese Siegesbeckiae Herba.

• Journal of Powder Materials
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• v.11 no.2
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• pp.143-148
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• 2004

In the present study, $TiO_2$ imbedded composite powders have been successfully prepared from the (Cu. Zn)/$TiO_2$ composite salt solution. The composite (Cu, Zn)/$TiO_2$ powders were formed by drying the solution at 200~$600^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting the decomposition ratio of aniline blue with UV-visible spectrophotometer(Shimazu Co., UV-1601). Phase analysis of (Cu, Zn)/$TiO_2$ composite powders was carried out by XRD and DSC, and powder size was measured with TEM. The mean particle size of composite powders was about 100mm. As the reduction temperature increases, a few zinc sulfide and oxide phases was formed and copper oxide phase was reduced. The decomposition ratio of aniline blue was about 80％ under the UV irradiation by the TiO$_2$ phase in the composite (Cu, Zn)/$TiO_2$ powders and similar decomposition ratio of 80％ was obtained at the UV lightless condition by virtue of Cu and Zn compounds.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.3
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• pp.152-158
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• 2009

Various fabrication methods have been used to synthesize sapphire which has qualities of jewelry well beyond the industrial class. Among them, the flux sapphire of Chatham Company which has as high value as jewelry was selected in order to compare natural and synthetic sapphire. First, the WD-XRF (Wavelength dispersive x-ray fluorescence spectrometer) was used to analyze the chemical composition of natural and synthetic sapphire. Although natural sapphire had very diverse chemical compositions, flux sapphire had small quantities of Mo, Pt and Pb elements in addition to the similar chemical ingredients to natural one. Pt is decisive proof of flux sapphire. Next, by investigating spectroscopic characteristics using UV-VIS Spectrophotometer after heat treatment at high temperatures of $1300^{\circ}C$ and $1500^{\circ}C$, the variation of 690 nm absorbance related to $Cr^{3+}$ was detected in the natural sapphire while those of the 690 nm absorbance (related to $Cr^{3+}$) as well as absorbance of 376 nm and 388 nm ($Fe^{3+}$) were seen in the flux sapphire. It was found that the difference in the absorbance variation of flux sapphire is greater than that of natural sapphire after heat treatment. The chemical composition and spectrum analysis were utilized to compare the natural sapphire and the flux synthetic sapphire.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1753-1758
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• 2012

A novel, efficient and controlled protocol for the synthesis and enhanced photocatalytic activity of $Au@TiO_2$ nanocomposite is developed. $TiO_2$ (P25) was pretreated by employing UV light (${\lambda}$ = 254 nm) and the pretreated $TiO_2$ was uniformly decorated by gold nanoparticles (AuNPs) in presence of sodium citrate and UV light. UV pretreatment makes the $TiO_2$ activated, as electrons were accumulated within the $TiO_2$ in the conduction band. These accumulated electrons facilitate the formation of AuNPs which were of very small size (2-5 nm), similar morphology and uniformly deposited at $TiO_2$ surface. It leads to formation of stable and crystalline $Au@TiO_2$ nanocomposites. The rapidity (13 hours), monodispersity, smaller nanocomposites and easy separation make this protocol highly significant in the area of nanocomposites syntheses. As-synthesized nanocomposites were characterized by TEM, HRTEM, TEM-EDX, SAED, XRD, UV-visible spectrophotometer and zeta potential. Dye degradation experiments of methyl orange show that type I ($Au@TiO_2$ nanocomposites in which $TiO_2$ was pretreated with UV light) has enhanced photocatalytic activity in comparison to type II ($Au@TiO_2$ nanocomposites in which $TiO_2$ was not pretreated with UV light) and $TiO_2$ (P25). This shows that pretreatment of $TiO_2$ provides type I a better catalytic activity.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1608-1614
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• 2004

This study was performed to evaluate the accuracy, validation and applicability of UV spectrophotometer (UV), Ion Chromatography (IC), and Detector tube (DT) methods for measuring ammonia (NH3) concentration in a swine confinement house and swine slurry storage tank. The mean values of $NH_{3}$ emitted from the house and slurry were 5.333 ppm and 42.192 ppm for the IC method; 4.13 ppm and 36.29 ppm for the Detector tube; and 5.417 ppm and 34.193 ppm for the UV method. The accuracy and the correlation of an ammonia level analyzed by the IC method compared to the UV method were 98% and 0.998($R^{2}$) in the swine confinement house and 94% and 0.997($R^{2}$) in the swine slurry storage tank. On the other hand, those of ammonia level measured by the Detector tube compared to the UV method were 77% and 0.957($R^{2}$) in the swine confinement house and 82% and 0.941($R^{2}$) in the swine slurry storage tank. This indicated that the accuracy and the correlation of the IC method compared to the UV method were higher than those of the Detector tube method compared to the UV method. Therefore, it was concluded that the IC method was more accurate in measuring ammonia concentration in a swine house and a swine slurry storage tank. The Detector tube method should not be applied to the swine slurry storage tank in which ammonia concentration is generally higher than 30 ppm because low accuracy is caused by a gross space between scales inscribed in the Detector tube.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.463-471
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• 2004

The Fabry-Perot interferometer filters for UV meter were designed using the design program of optical thin films. From the data obtained, two filters were fabricated. The transmittance of two filter were measured by spectrophotometer in order to analysis their optical property. The transmittance was controlled by the thickness of Ag reflector and the wavelength of the transmission was controlled by the thickness of $SiO_2$ spacer. The two UV filters were fabricated by the RF magnetron sputtering which are the multilayers of [air/$SiO_2$(174.6 nm)|Ag(78 nm)|$SiO_2$(68 nm)|Ag(78 nm)|Cr(5 nm)|glass] and [air/$SiO_2$(174.6 nm)|Ag(S8 nm)|$SiO_2$(56 nm)|Ag(58 nm)|Cr(S nm)|glass]. One filter has the maximum transmittance of 6% at the about 370nm and it has the transmittance of below 0.2% at 400nm. The other filter can be found that the transmittance is increased as the thickness of Ag is decreased and the wavelength of the transmission is controlled by the thickness of $SiO_2$ spacer layer.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.2
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• pp.149-158
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• 2013

L-ascorbic acid, the representative antioxidants, has a great effect on skin whitening, collagen synthesis, and anti-aging, but has low oxidative stability during storage. Therefore, in this study, thermal and oxidation properties of L-ascorbic acid under various storage conditions (powder, aqueous phase, changes of temperature, UV-irradiation, and inflow of external air etc.) were investigated. And the storage stability of ingredient was validated in the double-spaced pouch by analysing oxidation properties under each storage conditions (powder phase and blended with essence). In oder to analyze the thermal properties, TGA, DSC, and FT-IR analysis were carried out and UV-visible spectrophotometer & redox titration were used in parallel for oxidation property analyses. From the result of experiment, L-ascorbic acid was oxidized fast when it contained lots of metallic ion, hydroxy ion in aqueous solution under high temperature, UV-irradiation & inflow external air, whereas it was not oxidized for a long time when it was stored as pure powder although it has same condition as heating up, UV-irradiation & inflow external air. Based on this result, retention period of cosmetics which is using L-ascorbic acid, less stable material in oxidation can be innovatively increased when using double-spaced pouch that is designed and produced for separating storage of active ingredients.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.375-381
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• 1996

Five crystal modification of droperidol were prepared by recrystallization. They were characterized by UV spectrophotometer, DSC, and X-ray crystallography. Their dissolution pa tterns were also investigated. After storage of 2 months at 100% humidity, all polymorphic modifications were transformed.

• Journal of the Korean Applied Science and Technology
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• v.14 no.2
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• pp.65-70
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• 1997

The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was $600nm{\sim}612nm$. But it was identified that only methanol can be used to photographic emulsion.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.146-151
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• 2000

To evaluate anticaries and antiinflammation of Aloe vera peel, antimicrobial substances were extracted from Aloe vera peel and identified. The antimicrobial active substances of water extract were successfully purified with solvent fractionation, silica gel column chromatography, preparative thin layer chromatography and UV spectrophotometer. Two purified active substances were identified as aloe-emodin and barbaloin by Mass Spectrometer, 1H-NMR and FT-IR.