• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.264-270
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• 1997

This Study was carried out develop antitumor effect of the n-butanol soluble of fraction of Perilla frutescens on human skin melanoma cells. The antitumor activity of various fractions obtained form n-butanol soluble fraction of Perilla frutescens was evaluated in human skin melanoma cells. The antitumor activity of the n-butanol soluble fraction in human skin melanoma cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, neutral red (NR) assay and sulforhordamine B protein (SRB) assay of colorimetic assay methods. The light microscopic study was carried out to observe morphological changes of cultured human skin melanoma cells. These results were obtained follows; The fractions 5 and 6 of the n-butanol soluble fraction of P frutescens were shown significant antitumor activities. The number of human skin melanoma cells were decreased and tend to form cell cluster by treatment with actions 5 and 7 of the n-butanol soluble fraction of P. frutescens. The fraction 6 of the the n-butanol soluble fraction showed the highest antitumor activity on P. frutescens. These results suggest that the fraction 6 of the n-butanol soluble fraction of P. frutescens may be a valuable choice for the studies on the treatment of human skin tumors.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.103-107
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• 2002

Diphosphine dinuclear gold(I) complexes were synthesized from the reaction of bridged diphosphines and gold ions. As a bridged diphosphine, 1,2-bis(diphenylphosphino)metbane (dppm) or 1,1'-Bis(diphenylphosphino) ferrocene (dppf) was introduced. As anionic ligands, CI was first coordinated to Au, resulting in (diphosphine)$(AuCl)_{2}$. Then, the ligand, SPh, was substituted for Cl in the chloride complex to give (diphosphine)$(AuSPh)_{2}$. As a result, three digold complexes, (dppm)$(AuCl)_{2}$. (I), (dppf)$(AuCl)_{2}$. (II), and (dppf)$(AuSPh_{2}$. (III) were prepared in this study. The thermal properties were investigated at first hand to confirm that the gold complexes were in fact formed. The digold complexes were decomposed above $200^{\circ}C$ while the ligand, dppm or dppf, melts under $180^{\circ}C$ The photoluminescence (PL) spectra of the spin-coated thin films showed the maximum peak at 590, 595, and 540nm for the complex, I, II, and III, respectively. These complexes were found to give the orange color phosphorescence. Therefore, these digold complexes can be candidates for orange-red phosphorescent materials in organic electroluminescent devices (OELD). Further studies on application of the complexes as a dopant in an emitting layer are in progress in our laboratory.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.1 s.145
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• pp.119-127
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• 2006

Recently as a result of excessive development. pollution of the coast and occurrence of a typhoon year after year, fishermen suffer heavy losses in fish farming which is the one of the most important earnings ways. For solution of these problems, we need to go out into the open sea from an inland sea. In this study we suggested new fish cage which makes up for the structural weakness of existing wooden fish cages. It can farm fishes in the open sea of high wave and current with no damages from a typhoon. We substituted TPU(Thermoplastic Polyurethane) air chamber for existing styrofoam flotage which was harmful to the environment and impermanent. We used PE(Polyethylene) pipes for the maintenance of formation and the prevention of buoyancy loss caused by a breakdown of flotage. PE b rackets were designed to combine PE pipes with TPU air-chamber flotage. It has good strength and light weight. As a result of modeling test. it is great in buoyancy, strength and flexibility against wave. Because it can control buoyancy arbitrarily, moreover, we expect that it will reduce damages of a red water by applying it as semi-submerged fish cages.

• The Journal of Traditional Korean Medicine
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• v.15 no.1
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• pp.77-82
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• 2006

Lavandula vera is indispensable member of the herb family, used for perfumes and potpourri. Androgens have profound effects on the physiology of the sebaceous gland. Sebum is secreted due to the effect of androgen, which starts to be secreted at puberty. Using the human sebocyte cell line SZ95. the author investigated the inhibitory effect of Lavandula vera on the lipid production. Light microscopic finding were examined numerous cytoplasmic lipid droplets SZ95 cells by Oil red staining and lipid droplets were increased markedly by testosterone. On the other hand, combined treatment with Lavandula vera and testosterone resulted in a lower lipid droplets than with testosterone alone in a dose-dependent manner. These findings indicate that Lavandula vera acts antagonistically to testosterone and inhibits the lipid synthesis of SZ95 cells at the cellular level.

• Polymer(Korea)
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• v.38 no.1
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• pp.1-8
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• 2014

The effects of surface color and morphology on the mar behaviors of urethane-acrylate coated surfaces were examined. The superiority of mar resistance was observed in the order of white, red and black-colored samples. This can be explained by a contrast effect. In other words, in case of black colored sample, it takes place the defuse reflection of the incident light on the damaged region where mar damage exerts, leading to whitening phenomenon. Therefore, the damaged region is easily recognized by contrasting the black background. On the other hand, it is difficult for the white-colored sample to perceive the mar-damaged area by the white background acting as protecting coloration. As the gloss of urethane-acrylate coated surface increases, it is observed that there is an increase in the number of carbonyl (-C=O) function group, amount of ethylene and silica. The enhancements of surface rigidity by adding the silica particles and formation of carbonyl function groups by the surface oxidation lead to the increase in mar resistance, while the increase of polyethylene wax is responsible for the improved gloss and smooth-faced surface. Based on the above findings, technical approaches leading the improvement of mar resistance of the urethane-acrylate coated surface are discussed.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.271-276
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• 2018

The effects of activator ion on the structural, morphological, and optical properties of $LaNbO_4:RE^{3+}$ (RE = Dy, Dy/Sm, Sm) phosphors were investigated. X-ray diffraction patterns exhibited that all the phosphors showed a monoclinic system with a main (112) diffraction peak, irrespective of the concentration and type of activator ions. The grain size showed a slightly decreasing tendency as the concentration of $Sm^{3+}$ ions increased. The excitation spectra of the $LaNbO_4:Dy^{3+}$, $Sm^{3+}$ phosphor powders consisted of a strong charge transfer band centered at 259 nm in the range of 220-290 nm and five weak peaks. The emission spectra of the $La_{0.95}NbO_4$:5 mol% $Dy^{3+}$ phosphors exhibited two intense yellow and blue bands centered at 575 nm and 479 nm respectively, which resulted from the $^4F_{9/2}{\rightarrow}^6H_{13/2}$ and $^4F_{9/2}{\rightarrow}^6H_{15/2}$ transitions of $Dy^{3+}$. As the concentration of $Sm^{3+}$ was increased, the intensity of the yellow emission band was gradually decreased, while those of orange and red emission bands centered at 604 and 646 nm began to appear and reached maxima at 5 mol%, and then decreased rapidly with further increases in the $Sm^{3+}$ concentration. These results indicated that white light emission could be realized by controlling the concentrations of the $Dy^{3+}$ and $Sm^{3+}$ ions incorporated into the $LaNbO_4$ host crystal.

• Fashion & Textile Research Journal
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• v.21 no.4
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• pp.509-514
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• 2019

Cotton fabrics were treated with gelatin to enhance dyeability and color strength when using Caesalpinia sappan dye. Gelatin was used as the protein and a pad-dry- cure method was used for the treatment process (2, 4, 6, 8, 10, 12, 14g/l concentration). Pretreated fabrics were mordanted with 10% alum. Fabrics were then dyed with freeze-dried sappan wood water extract powder form. Dyed samples were assessed in regards to dyeing behavior and color fastness. Comparing untreated and gelatin treated samples from the SEM images indicated that the Gelatin treatment (10g/l) resulted in an enhanced surface roughness that was relative to that of untreated cotton. Padding cotton with gelatin at 6g/l concentration afforded dyed fabrics with a 2 times increase in the K/S value over that of untreated fabrics. All dyed samples were red color with a significant enhancement in the sample color strength (K/S) being observed for pretreated samples. pH values favor dye absorption with pH 7 yielding the highest color strength. Dyeing at an elevated temperature resulted in a lower color strength and reddish-dull color. Longer dyeing times created greater color strengths for untreated and gelatin treated cotton. Increased dye concentrations resulted in higher K/S values for both gelatin treated and untreated cotton. As for color fastness, gelatin treated and untreated cotton fabrics dyed with sappan wood extract showed a relatively low rating in washing fastness (color change 1 rating), light fastness (1 rating), and rubbing fastness (wet:1-2, dry:3-4 rating).

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.86-90
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• 2017

$Tb^{3+}$ or $Eu^{3+}$ or $Ce^{3+}$-doped $CaYAlO_4$ phosphor were synthesized by solid-state method. $CaYAlO_4:Tb^{3+}$ is shown that the $Tb^{3+}$-doping concentration has a significant effect on the $^5D_4/^5D_3{\rightarrow}7F_J$ (J=6,...,0) emission intensity of $Tb^{3+}$. The $CaYAlO_4:Tb^{3+}$ phosphors show tunable photoluminescence from blue to yellow with the change of doping concentration of $Tb^{3+}$ ions. The $CaYAlO_4:Eu^{3+}$ phosphors exhibit a red-orange emission of $Eu^{3+}$ corresponding to $^5D_0$, $_{1,2}{\rightarrow}^7F_J$ (J=4,...,0) transitions. The $CaYAlO_4:Ce^{3+}$ phosphors show a blue emission due to $Ce^{3+}$ ions transitions from the 5d excited state to the $^2F_{5/2}$ and $^2F_{7/2}$ ground states. The decay time of $CaYAlO_4:Tb^{3+}$ phosphors decrease from 1.33 ms to 0.97 ms as $Tb^{3+}$ concentration increases from 0.1 mol% to 7 mol%. The decay time of $CaYAlO_4:Eu^{3+}$ phosphors increase from 0.94 ms to 1.17 ms as $Eu^{3+}$ concentration increases from 1 mol% to 9 mol%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.5
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• pp.387-392
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• 2019

$Dy^{3+}$ and $Eu^{3+}$-co-doped $La_2MoO_6$ phosphor thin films were deposited on sapphire substrates by radio-frequency magnetron sputtering at various growth temperatures. The phosphor thin films were characterized using X-ray diffraction (XRD), scanning electron microscopy, ultraviolet-visible spectroscopy, and fluorescence spectrometry. The optical transmittance, absorbance, bandgap, and photoluminescence intensity of the $La_2MoO_6$ phosphor thin films were found to depend on the growth temperature. The XRD patterns demonstrated that all the phosphor thin films, irrespective of growth temperatures, had a tetragonal structure. The phosphor thin film deposited at a growth temperature of $100^{\circ}C$ indicated an average transmittance of 85.3% in the 400~1,100 nm wavelength range and a bandgap energy of 4.31 eV. As the growth temperature increased, the bandgap energy gradually decreased. The emission spectra under ultraviolet excitation at 268 nm exhibited an intense red emission line at 616 nm and a weak emission line at 699 nm due to the $^5D_0{\rightarrow}^7F_2$ and $^5D_0{\rightarrow}^7F_4$ transitions of the $Eu^{3+}$ ions, respectively, and also featured a yellow emission band at 573 nm, resulting from the $^4F_{9/2}{\rightarrow}^6H_{13/2}$ transition of the $Dy^{3+}$ ions. The results suggest that $La_2MoO_6$ phosphor thin films can be used as light-emitting layers for inorganic thin film electroluminescent devices.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2283-2289
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• 2018

$TiO_2$ microspheres were successfully synthesised by simple solution phase method by using various amount of titanium butoxide as precursor. The prepared $TiO_2$ were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance absorption spectra (UV-DRS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XRD analysis revealed that the as-synthesized $TiO_2$ microsphere poses an anatase phase. The photocatalytic degradation experiments were carried out with three different dyes, such as methylene blue, brilliant black, reactive red-120 for four hours under UV light irradiation. The results show that $TiO_2$ morphology had great influence on photocatalytic degradation of organic dyes. The experimental results of dye mineralization indicated the concentration was reduced by a high portion of up to 99% within 4 hours. On the basis of various characterization of the photocatalysts, the reactions involved to explain the photocatalytic activity enhancement due to the concentration of titanium butoxide and morphology include a better separation of photogenerated charge carriers and improved oxygen reduction inducing a higher extent of degradation of aromatics.