• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1147-1151
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• 2001

We investigated stabilities of blue pigment extracted from Gardenia jasminoides at various conditions to check its applicability for beverages. Gardenia blue pigment with maximum absorption at 587 nm was obtained from the reaction of glycine and genipin (aglycone of geniposide). The blue pigment was found to be relatively unstable at acidic pH but very stable at alkaline conditions with half-life values of 102 days and 126 days at PH 9.0 and PH 11.0, respectively. The pigment also showed high thermal stability with half-life value of 55, 18, and 2 days at 50, 70, and 9$0^{\circ}C$, respectively. The addition of inorganic ions, sugars, and amino acids to model beverage containing this blue pigment increased retention rate at room temperature while addition of vitamin C decreased the stability. The sensory evaluation of the model beverage showed that inorganic ions and amino acids increased overall acceptability, indicating that the blue pigments of Gardenia jasminoides can be used as a natural colorant for leverage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.27-27
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• 2008

The different concentration Indium doped ZnO:Al films were grown on glass substrates (Corning 1737) at $200^{\circ}C$ by pulsed laser deposition. The indium doping in AZO films shows the critical effect on the crystallinity, resistivity, and optical properties of the films. The AZO films doped with 0.3 atom % indium content exhibit the highest crystallinity, the lowest resistivity of $4.5\times10^{-4}\Omega$-cm, and the maximum transmittance of 93%. The resistivity of the indium doped-AZO films is strongly related with the crystallinity of the films. The carrier concentration in the indium doped-AZO films linearly increases with increasing indium concentration. The mobility of the AZO films with increasing indium concentration was reduced with an increase in carrier concentration and the decrease in mobility was attributed to the ionized impurity scattering mechanism. In an optical transmittance, the shift of the optical absorption edge to shorter wavelength strongly depends on the electronic carrier concentration in the films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.335-335
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• 2008

Phosphate glass samples with various $Cr_2O_3$ and $Er_2O_3$ contents based upon $55P_2O_5\cdot24BaO\cdot10K_2O\cdot4Al_2O_3\cdot6Yb_2O_3$ were prepared. The prepared glass compositions are dehydrated using gas bubble flow method in open system and investigated the effects of the eliminating of OH groups from the glass melts with bubbling time. It was found that the probability of $Er^{+3}$ fluorescence quenching by OH groups oscillations linear depends upon the OH groups absorption coefficients in the maximum of the stretch vibrations band at $3500cm^{-1}$ while $Er^{+3}$ concentration range is between $1.6\times10^{19}$ and $21.2\times10^{19}$ ion/$cm^3$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.10
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• pp.461-466
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• 2006

In the present work, we investigated the photodissolution and photodiffusion effect on the interface of Ag/chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film by measuring the absorption coefficient, the optical density, the resistance change of Ag layer. It was found that the photodissolutioniphotodiffution ratio depends on the magnitude of photon energy absorbed in the chalcogenide thin film and the depth of photodiffution was proportional to the square root of the exposed time. Also, we have investigated the holographic grating formation with P-polarization states on chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film and $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film. Holographic gratings have been formed using He-Ne laser (632.8 nm) which have a smaller energy than the optical energy gap, $E_g\;_{opt}$ of the film, i. e., an exposure of sub-bandgap light $(h{\upsilon} under P-polarization. As the results, we found that the diffraction efficiency on $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film was more higher than that on single $As_{40}Ge_{10}Se_{15}S_{35}$ thin film. Also, we obtained that the maximum diffraction efficiency was 0.27 %, 1,000 sec on $As_{40}Ge_{10}Se_{15}S_{35}\;(1{\mu}m)/Ag$ (10 nm) double layer structure thin film by (P: P) polarized recording beam. It will offer lots of information for the photodoping mechanism and the analyses of chalcogenide thin films.

• Journal of Environmental Health Sciences
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• v.40 no.5
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• pp.407-412
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• 2014

Objectives: The internal dose of ethyl parabens is important in order to evaluate the risk of this chemical. However, there are little PK model data for parabens to apply this. This experiment attempted PK modeling to ascertain PK values. Methods: Twenty mg/kg ethyl paraben was administered orally to Sprague-Dawley rats at the same point in time. The rats were sacrificed at times 0, 15, 30 and minutes, and 1, 2, 4, 8, 12, 24 hours after oral gavage. Blood and urine were collected and pretreated for analysis. Accuracy, precision and LOD (limit of detection) were calculated for this analysis. Ethyl paraben, detected by HPLC-MS, was applied to PK modeling using Berkeley Madonna. Results: This study showed 100.1-103.7% accuracy, 1.4-3.7% precision and a 1.0 ng/mL limit of detection. Orally administered ethyl paraben reached maximum concentration after 30 minutes of dosing in serum and urine of rats. The concentrations were 2,354 ng/mL in serum and 386,000 ng/mL in urine samples. These peak concentrations were excreted after one hour of intubation over 12 hours. For the pharmacokinetic parameters of ethyl paraben revealed using Berkeley Madonna, the absorption rate was 5.539/hour, the excretion rate was 0.048/hour, the half-life was 14.441 hours and AUC was 481,186 ng hour/mL. Conclusion: Orally administered ethyl paraben was absorbed rapidly in rats and excreted in urine. This chemical, ethyl paraben, accumulated in the body but was excreted over 12 hours after dosing.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.18 no.1
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• pp.1-41
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• 1992

A new and unique class of nonionic surfactants was synthesized by reacting biological a-tocopherol with ethylene oxide for functional cosmetics. The structures were confirmed by Hl-UMR, FT-lR, TLC and elemental analysis. POV and conjugated diene value study for EPO showed POE(n)TE had antioxidative effect similar to tocopheryl acetate Protective effect on cell membrane in photohemolysis of POE(5)TE, POE(10)TE and POE(18)TE were slightly lower than tocopherol but higher than nonoxynol-12, and POE(10)TE had UV absorption power comparable with tocopherol and homosalate. Biological activity of the hydrophobic group of the new surfactants make them unique and different from those of conventional nonionic surfactants Systematic safety evaluations of POE(n)TEs on the skin and eye proved that they are as safe as tocopherol. The results of physicochemical study showed POE(10)TE had the lowest CMC value, POE(18)TE had the maximum surface tension reduction and the highest foam volume and POE(n)TEs had various HLB values by the degree of ethoxylation. The test resul Is of technological and practical applications of these surfactants for cosmetics showed some POE(n)TEs were superior to conventional surfactants. POE(5)TE in W/O emulsions, POE(10)TE and POE(12)TE in O/W emulsions, POE(12)TE in dispersions, POE(18)TE in solubilizations and POE(50)TE in gelations were shown to be excellent which was considered due to the structural characteristic and formation of liquid crystals of POE(n)TEs. By the development and applications of these excel lent multi-functional surfactants, innovative functional cosmetics were successfully formulated.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1945-1950
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• 2007

Two fluorene-based conjugated copolymers containing hexyl-thiophene derivatives, PF-1T and PF-4T, were synthesized via the palladium-catalyzed Suzuki coupling reaction. The number-average molecular weights (Mn) of PF-1T and PF-4T were found to be 19,100 and 13,200, respectively. These polymers were soluble in common organic solvents such as chloroform, chlorobenzene, toluene, etc. The UV-vis absorption maximum peaks of PF-1T and PF-4T in the film state were found to be 410 nm and 431 nm, respectively. Electrochemical characterization revealed that these polymers have low highest occupied molecular orbital (HOMO) levels, indicating good resistance against oxidative doping. Thin film transistor devices were fabricated using the top contact geometry. PF-1T showed much better thin-film transistor performance than PF-4T. A thin film of PF- 1T gave a saturation mobility of 0.001-0.003 cm2 V?1 s?1, an on/off ratio of 1.0 × 105, and a small threshold voltage of ?8.3 V. To support TFT performance, we carried out DSC, AFM, and XRD measurements.

• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.167-175
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• 2003

There is accumulating evidence for a strong link between nuclear starbursts and AGN. Molecular gas in the central regions of galaxies plays a critical role in fueling nuclear starburst activity and feeding central AGN. The dense molecular ISM is accreted to the nuclear regions by stellar bars and galactic interactions. Here we describe recent observational results for the OB star forming regions in M51 and the nuclear star burst in Arp 220 - both of which have approximately the same rate of star formation per unit mass of ISM. We suggest that the maximum efficiency for forming young stars is an Eddington-like limit imposed by the radiation pressure of newly formed stars acting on the interstellar dust. This limit corresponds to approximately 500 $L_{\bigodot} / M_{\bigodot}$ for optically thick regions in which the radiation has been degraded to the NIR. Interestingly, we note that some of the same considerations can be important in AGN where the source of fuel is provided by stellar evolution mass-loss or ISM accretion. Most of the stellar mass-loss occurs from evolving red giant stars and whether their mass-loss can be accreted to a central AGN or not depends on the radiative opacity of the mass-loss material. The latter depends on whether the dust survives or is sublimated (due to radiative heating). This, in turn, is determined by the AGN luminosity and the distance of the mass-loss stars from the AGN. Several AGN phenomena such as the broad emission and absorption lines may arise in this stellar mass-loss material. The same radiation pressure limit to the accretion may arise if the AGN fuel is from the ISM since the ISM dust-to-gas ratio is the same as that of stellar mass-loss.

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.177-183
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• 2010

We report on the deposition of ZnO films using a metal organic chemical vapor deposition (MOCVD) as a function of pushing pressure and kind of reactant such as oxygen gas and water A diethylzinc (DEZ) is supplied and controlled by Ar pushing pressure through bubbling system. Oxygen gas and water are used as reactant in order to form oxidation. We knew that the surface roughness is related in the process conditions such as reactant kind and DEZ flow rate. A substrate temperature has little role of surface roughness with $O_2$ reactant. However, $H_2O$ reactant makes it to increase over the 20 times. We could get the maximum roughness of 39.16 nm at the 90 sccm of DEZ Ar flow rate, the 8 Pa of $H_2O$ vapor pressure, and the $140^{\circ}C$ of substrate temperature. In this paper, we investigated the ZnO films for the application to the light absorption layer of solar cell layer.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.46-51
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• 1978

One of yellowed rice toxins, luteoskyrin, was investigated with respect to its identification, quantitation and producibility by Penicillium islandicum isolated from deteriorated rice. 1) Luteoskyrin was best resolved by thin-layer chromatography with silica gel G plate impregnated with 0. 5 N oxalic acid and acetone : n-hexane : water (6 : 3 : 1.5, upper layer) solvent system. The isolated yellow spot showed maximum absorption bands at 426 and 448 nm and changed to purple color upon exposure to sunlight for $2{\sim}3$ hours. 2) Detection limit for luteoskyrin was 4 ppm in elution-colorimetry and 0.1 ppm in densitometry after TLC. Assuming that the tolerance for luteoskyrin in rice is set below 3.68 ppm, densitometry is usable for its screening in grain samples 3) Producibility of luteoskyrin by Pen. islandicum was shown to be 11 mg/g mycelial mat in liquid culture and 40 mg/g autoclaved rice.