• 한국전기전자재료학회논문지
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• 제25권7호
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• pp.491-495
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• 2012

The effects of various buffer layers on the $In_2O_3$ transparent conducting films grown on glass substrates by radio-frequency reactive magnetron sputtering were investigated. The $In_2O_3$ thin films were deposited at $400^{\circ}C$ of growth temperature and 100% of oxygen flow rate. The optical, electrical, and structural and morphological properties of the $In_2O_3$ thin films subjected to buffer layers were examined by using ultraviolet-visible spectrophotometer, Hall-effect measurements, and X-ray diffractometer, respectively. The properties of $In_2O_3$ thin films showed different results, depending on the type of buffer layer. As for the $In_2O_3$ thin film deposited on ZnO buffer layer, the average transmittance was 89% and the electrical resistivity was $7.4{\times}10^{-3}\;{\Omega}cm$. The experimental results provide a way for growing the transparent conducting film with the optimum condition by using an appropriate buffer layer.

• 한국어류학회지
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• 제17권2호
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• pp.91-97
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• 2005

1997년부터 2004년까지 우리나라 연안에서 채집된 주둥치속 어류의 주요 계수 계측 형질과 형태적 특징을 분석하여 분류학적으로 검토하였다. 그 결과 한국산 주둥치과 어류는 왜주둥치 Leiognathus elongatus, 줄무늬주둥치 L. fasciatus, 줄주둥치 L. lineolatus, 주둥치 L. nuchalis, 점주둥치 L. rivulatus와 노랑점주둥치 L.bindus 등 모두 1속 6종으로 분류되었다. 이 가운데 L.bindus는 한국산 미기록종으로 확인되어 계수계측치를 제시하고, 국명을 "노랑점주둥치"로 명명하였다. 노랑점주둥치는 체장이 체고의 1.8~1.9배이며, 입은 앞쪽으로 돌출되고, 등지느러미의 2~5 극조 사이의 기조막에 밝은 오렌지색의 반점이 있는 것이 특징이다. 본 연구에서는 한국산 주둥치속 어류 6종에 대한 주요 계수, 계측 형질과 형태적 특징을 기재하고 각 종에 대한 검색표를 제시하였다.

• 천문학회지
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• 제44권3호
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• pp.97-108
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• 2011

The photometric light curves of the W-type W UMa eclipsing contact binary system BB Pegasi have been found to be extremely asymmetric over all the observed 63 years in all wavelengths UBVR. The light curves have been characterized by occultation primary minima. Hence, the morphology of these light curves has been studied in view of these different asymmetric degrees. The system shows a distinct O'Connell effect, as well as depth variation. A 22.96 years of stellar dark spots cycle has been determined for the system. Almost the same cycle (22.78 yr) has been found for the depth variation of MinI and MinII. We also present an analysis of mid-eclipse time measurements of BB Peg. The analysis indicates a period decrement of $5.62{\times}10^{-8}$ day/yr, which can be interpreted in terms of mass transfer at a rate of $-4.38{\times}10^{-8}M_{\odot}$/yr, from the more to the less massive component. The O - C diagram shows a damping sine wave covering two different cycles of 17.0 yr and 12.87 yr with amplitudes equal to 0.0071 and 0.0013 day, respectively. These unequal durations show a non-periodicity which may be explained as a result of magnetic activity cycling variations due to star spots. The obtained characteristics are consistent with similar chromospherically active stars, when applying the Applegate's (1992) mechanism.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.309-316
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• 1992

The effects of lipid peroxidation on the fluidity of the lipid bilayers of the human erythrocyte ghosts and egg-lecithin phospholipid liposomes have been studied. For the measurements of the peroxidation extent and the fluidity of the membranes, the thiobarbituric acid-reactive substances and the fluorescence depolarization of 1, 6-diphynyl-1, 3, 5-hexatriene labelled into the membrane were employed, respectively. The lipid peroxidation was performed in hypoxanthine/xanthine oxidase/ferrous ion, and hydrogen peroxide/ferrous ion systems. The results of these experiments show that both of the xanthine oxidase and hydrogen peroxide systems effectively. The lipid peroxidation decreased the fluidity of the membranes, especially at the very early stage of the peroxidation reaction. The decrease in the fluidity of membrane by the lipid peroxidation has been ascribed to the alteration of the polyunsaturated acyl chains of lipids and cross linkages among the membrane components. However, under drastic condition of lipid peroxidation, tdhe fluidity of the membrane rather increased possibly due to the deterioration of the membrane integrity by the peroxidation. Morphological change of the erythrocyte on peroxidation has also been observed.

• Current Optics and Photonics
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• 제3권6호
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• pp.571-576
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• 2019

The morphological changes of anthracnose (fungus) -infected tomato seeds have been studied to identify the infection and characterize its effect. Full-field optical coherence tomography (FF-OCT) has been utilized as a nondestructive but efficient modality for visualizing the effects of fungal infection. The cross-sectional images extracted from a stack of en face FF-OCT images showed significant changes with infection in the seed structure. First of all, the seed coat disappeared with the infection. The thickness of the seed coat of a healthy seed was measured as 28.2 ㎛, with a standard deviation of 1.2 ㎛. However, for infected seeds the gap between surface and endosperm was not appreciably observed. In addition, the measurements confirmed that the dryness of seeds did not affect the internal seed structure. The reconstructed three-dimensional (3D) image revealed that the permeability of the seed coat, which plays the vital role of protecting the seed, is also affected by the infection. These results suggest that FF-OCT has good potential for the identification of fungus-infected tomato seeds, and for many other tasks in agriculture.

• 한국염색가공학회지
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• 제7권2호
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• pp.24-31
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• 1995

The properties of carbon fibers made from PAN are controlled by the heat treatment conditions. The length changes of high strength homo-PAN and co-PAN (acrylonitrile/acrylamide= 98/2wt% ) fibers under constant tensile stress during heat treatment in nitrogen gas were investigated by measuring the shrinkage behavior. In order to elucidate the relation between the length and fine structure change, the measurements of the crystalline orientation and birefringence index etc. were made for the fibers treated under linear heating up to 27$0^{\circ}C$. There are two regions in the length change with heat treatment temperature. The change in the initial period is mainaly due to the relaxation of amorphous molecular chain confined by the fiber-manufacture process. The length change in later period is considered to arise as cyclization reactions. The co-PAN fibers caused a larger shrinkage, while the onset of the shrinkage change in later period is, shifted to lower temperature. Significant morphological changes are shown to precede onset of the cyclization reactions and also during these reactions.

• Korea-Australia Rheology Journal
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• 제13권4호
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• pp.189-196
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• 2001

The phase morphology is an important factor in the rheology of immiscible polymer blends. Through its size and shape, the interface between the two phases determines how the components and the interface itself will contribute to the global stresses. Rheological measurements have been used successfully in the past to probe the morphological changes in model blends, particularly for dilute systems. For more concentrated blends only a limited amount of systematic rheological data is available. Here, viscosities and first normal stress differences are presented for a system with nearly Newtonian components, the whole concentration range is covered. The constituent polymers are PDMS and PIB, their viscosity ratio can be changed by varying the temperature. The data reported here have been obtained at 287 K where the viscosities of the two components are identical. By means of relaxation experiments the measured stresses are decomposed into component and interfacial contributions. The concentration dependence is quite different for the two types of contribution. Except for the component contributions to the shear stresses there is no clear indication of the phase inversion. Plotting either the interfacial shear or normal stresses as a function of composition produces in some cases two maxima. The relaxation times of these stresses display a similar concentration dependence. Although the components have the same viscosity, the stress-component curves are not symmetrical with respect to the 50/50 blend. A slight elasticity of one of the components seems to be the cause of this effect. The data for the more concentrated blends at higher shear rates are associated with a fibrillar morphology.

• 천문학회지
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• 제43권6호
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• pp.191-200
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• 2010

We present the Korea Institute for Advanced Study Value-Added Galaxy Catalog (KIAS VAGC), a catalog of galaxies based on the Large Scale Structure (LSS) sample of New York University Value-Added Galaxy Catalog (NYU VAGC) Data Release 7. Our catalog supplements redshifts of 10,497 galaxies with 10 < $r_P\;{\leq}\;17.6$ (1455 with 10 < $r_P\;{\leq}\;14.5$) to the NYU VAGC LSS sample. Redshifts from various existing catalogs such as the Updated Zwicky Catalog, the IRAS Point Source Catalog Redshift Survey, the Third Reference Catalogue of Bright Galaxies, and the Two Degree Field Galaxy Redshift Survey have been put into the NYU VAGC photometric catalog. Our supplementation significantly improves spectroscopic completeness: the area covered by the spectroscopic sample with completeness higher than 95% increases from 2.119 to 1.737 sr. Our catalog also provides morphological types of all galaxies that are determined by the automated morphology classification scheme of Park & Choi (2005), and related parameters, together with fundamental photometry parameters supplied by the NYU VAGC. Our catalog contains matches to objects in the Max Planck for Astronomy (MPA) & Johns Hopkins University (JHU) spectrum measurements (Data Release 7). This new catalog, the KIAS VAGC, is complementary to the NYU VAGC and MPA-JHU catalog.

• 한국재료학회지
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• 제25권7호
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• pp.358-363
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• 2015

We present an excellent detection for nitrogen monoxide (NO) gas using polycrystalline ZnO wire-like films synthesized via a simple method combined with sputtering of Zn metallic films and subsequent thermal oxidation of the sputtered Zn nanowire films in dry air. Structural and morphological characterization revealed that it would be possible to synthesize polycrystalline hexagonal wurtzite ZnO films of a wire-like nanostructure with widths of 100-150 nm and lengths of several microns by controlling the sputtering conditions. It was found from the gas sensing measurements that the ZnO wire-like thin film gas sensor showed a significantly high response, with a maximum value of 29.2 for 2 ppm NO at $200^{\circ}C$, as well as a reversible fast response to NO with a very low detection limit of 50 ppb. In addition, the ZnO wire-like thin film gas sensor also displayed an NO-selective sensing response for NO, $O_2$, $H_2$, $NH_3$, and CO gases. Our results illustrate that polycrystalline ZnO wire-like thin films are potential sensing materials for the fabrication of NO-sensitive high-performance gas sensors.

• Macromolecular Research
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• 제12권5호
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• pp.534-539
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• 2004

Two biopolymers, silk fibroin (SF) and chitosan, were conjugated by tyrosinase (EC 1.14.18.1), a polyphenolic oxidase, to improve their physicochemical properties, such as their thermal properties and morphological stabilities in organic solvents. The crosslinking between SF and chitosan took place mainly through Michael addition reactions. A main reaction between the amino groups in chitosan and o-quinone, the oxidation product of the tyrosyl residue in SF, was confirmed by UV spectroscopy. Measurements of viscosity and light scattering indicated that the crosslinked SF/chitosan conjugate was compact: it had a smaller particle size because of tight bonding forces between the SF and chitosan molecular chains. Thermal decomposition of SF/chitosan conjugates crosslinked by tyrosinase occurred at higher temperatures. The adhesiveness of the SF/chitosan conjugates decreased steadily as the crosslinking reaction progressed. We propose that this new crosslinking method be used for the preparation of silk fibroin/chitosan conjugates using tyrosinase. We expect that SF/chitosan conjugates crosslinked by tyrosinase can be used preferentially in biomedical applications because of its unique properties and non-toxicity.