• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.965-971
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• 2001

$\beta$-Ga$_2$O$_3$ nanobelts and nanoparticles were synthesized from mechanically ground GaN powders with thermal annealing in a nitrogen atmosphere and an oxygen atmosphere, respectively. The study of field emission scanning electron microscopy (FESEM) on the microstructures of nanomaterials revealed that the nanobelts synthesized in the nitrogen atmosphere are with the range of 20~1000nm width and 10 ~100nm thickness, and that nanomaterials are nanoparticles with 20~50nm radius obtained by thermal annealing in an oxygen atmosphere. The crystal structure of the $\beta$-Ga$_2$O$_3$ nanobelts and nanoparticles was in this study investigated by X-ray diffractometer (XRD) and high-resolution transmission electron microscope (HRTEM). The formation processes of the nanobelts and nanoparticles will be discussed in this paper.

• KSBB Journal
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• v.17 no.1
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• pp.54-58
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• 2002

Curdlan gel containing various hydrophobic materials was prepared. The homogenized suspension of curdlan and hydrophobic materials was healed at $100^{\circ}C$. The curdlan gel can contain hydrophobic material up to 27%(v/v). When gel was compressed, only water in the gel was removed. When immersed in water, the dried gel absorbed water and became the original wet gel. The syneresis of gel decreased with the concentration of hydrophobic material added. DHA content of dried gel was about 90%. $\beta$-cyclodextrin inclusion complexes containing DHA were prepared with addition of water and ethanol. X-ray diffractograms of complexes showed a specific peak at 7-$8^{\circ}C$ and FT-IR spectrum of complex showed a specific C=O peak at $1745\textrm{cm}^{-1}$. Inclusion complex containing DHA was microcapsulated with curdlan and pullulan.

• Development and Reproduction
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• v.21 no.4
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• pp.391-397
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• 2017

Skeletal deformities are significant problems that affect the growth and commercial value of fish reared in hatcheries. However, studies of bone metabolic process related to skeletal deformities are limited. We investigated the potential correlation between bone deformities and plasma calcium, phosphorus, and estradiol-$17{\beta}$ levels in reared red spotted grouper (Epinephelus akaara) juveniles. We collected E. akaara frys from private farms at 110, 140, 180 and 300 days after hatching (DAH), and classified the normal and deformed fish by observing their external shape and inner frame by soft X-ray. We also analyzed the calcium, phosphorous, and estradiol-$17{\beta}$ levels in their plasma. A comparison between normal and deformed fish, indicated that calcium and estradiol-$17{\beta}$ levels were higher in deformed fish than in the normal at 180 and 300 DAH. The level of phosphorus was also higher in deformed individuals than in normal fish, but only at 300 DAH. These results suggest that skeletal deformities are associated with increases in plasma calcium, phosphorus, and estradiol-$17{\beta}$ levels.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.162-166
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• 1985

Three isozymes of Carboxymethyl Cellulase $(FI^*,\;FII^*,\;FIII)$ and two fractious of ${\beta}-1,4-D-Cellobiohydrolase$(CI, CIl) from Aspergillus niger were purified by Sephadex G-150, DEAE-Sephadex and Sephadex G-75 column chromatography. From the results of enzymatic hydrolysis and X-ray diffraction, ${\beta}-1,4-D-Cellobiohyarolase$ has a high activity toward highly crystalline cellulose such as filter paper and acts synergistically with Cx enzyme.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.59-64
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• 1998

Kim & Beuermann (1995, 1996)have developed a model for the propagation of X-rays from the accreting white dwarfthrough the infalling material and the re-emission of the energy deposited by photo-absorption in the optical (and UV) spectral range. By using this model, we calculate the profiles of the $H_{\gamma}$ emission-line spectrum of intermediate polars. Photoabsorption of X-ray by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle, these dependencies allow us to obtain improved insight into the accretion geometry of the intermediate polars. We present results of our calculations and compare them with the $H{\beta}$ line spectrum(Kim & Beuermann 1996).

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.360-363
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• 1999

• Journal of the Society of Cosmetic Scientists of Korea
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• v.15 no.1
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• pp.51-62
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• 1989

Inclusion complex formation of octyldimethl p-aminobenzoate with $\beta$-cyclodextrin in aqueous solution and in the solid state was studied by the solubility method, spectroscopic(UV, FT-lR) and X -ray diffractometry. The solid complex of octyldimethy p-aminobenzoate with $\beta$-cyclodextrin was obtained in molar ratio of 1 : 2(guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and p -cyclodextrin in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of $\beta$-cyclodextrin inclusion complex.

• Textile Coloration and Finishing
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• v.6 no.2
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• pp.24-29
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• 1994

In order to investigate the crystallization in silk fibroin induced by acid treatment and its photo-yellowing reduction effect. silk fibroin were immersed in PH 3.5~4.0 sulfuric acid and 0.01N hydro-chloric acid at 2$0^{\circ}C$, and the changes of crystallinity were measured by infrared spectroscopy, X-ray diffraction. Yellowness index caused by UV irradiation were also observed. The results are as follows : 1. ${\beta}$-form transition occurs when the silk fibroin are immersed at 2$0^{\circ}C$ in pH 3.5~4.0 sulfuric acid and 0.01N hydro-chloric acid. Formation of new hydrogenbond in molecules on the amorphous region induced ${\beta}$-form structure, and increased crystallinity. 2. Crystallization owing to $\beta$-form transition reduced the initial yellowness index by ultraviolet irradiation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.848-850
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• 2001

In this work, we investigated on the white-colored ribbon fiber synthesized from GaN powder. We convinced the formation of monoclinic phase $\beta$-Ga$_2$O$_3$from the X-ray diffraction pattern on ribbon fiber. The 10 K PL spectrum consisted with the strong emission band caused by self-activated optical center at 3.464 eV with the full-width at half maximum of 48 meV and the impurity related emission bands. Through this work, the optical properties and the electrical conductivity of $\beta$-Ga$_2$O$_3$, it will be useful for the fabrication of optoelctronic devices operating in visible spectrum region.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1283-1292
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• 1994

Ultra-fine $\beta$-SiC powders were fabricated by self-propagating high temperature synthesis process (SHS) using chemical furnace. The dependences of the C powders with different surface areas, the molar ratios of C/Si, the weight ratios of chemical fuel content, and pellet diameter-size on synthesis were investigated. Compositional and structural characterization of these powders was carried out by scanning electron micrograph and X-ray diffraction. The $\beta$-SiC powders which had C/Si mole ratio=1.05, 3 times chemical fuel contents, and pellet diameter=20 mm were optimum for synthesis efficiency. By optimizing process-variables, it is possible to fabricate $\beta$-SiC powders which have little secondary phases ($\alpha$-SiC).