• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.1
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• pp.32-43
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• 1996

A $CdIn_{2}Te_{4}$ single crystal was grown by modified veritical bridgman method. The $CdIn_{2}Te_{4}$ single crystal was evaluated to be tetragonal by the powder method. The $CdIn_{2}Te_{4}$ single crystal was confirmed to be grown with its c axis along the lengthe of the boule by the Laue reflection method. Hall effect of $CdIn_{2}Te_{4}$ single crystal was estimated by van der pauw method from 293 K to 30 K. Hall data of the sample perpendicular to c axis was $n=8.75{\times}10^{23}electrons/m^{3},\;R_{H}=7.14{\times}10^{-5}m^{3}/C,\;{\sigma}=176.40{\omega}^{-1}m^{-1},\;{$\mu}=3.41{\times}10^{-2}m^{2}/V.s$ and the sample parallel to c axis was $n=8.61{\times}10^{23}electrons/m^{3},\;R_{H}=7.26{\times}10^{-5}m^{3}/C,\;{\sigma}=333.38{\omega}^{-1}m^{-1}\;and\;{$\mu}=2.42{\times}10^{-2}m^{2}/V.s$ for room temperature. The value of Hall coefficient on sample perpendicular or parallel to c axis were positive. There $CdIn_{2}Te_{4}$ single crystal was p-type semiconductor.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.192-197
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• 2010

The spinel compound was obtained by the thermal decomposition of Zn-Co and Zn-Ni gel prepared by sol-gel method using oxalic acid as a chelating agent. The formation of spinel compound has been comfirmed by thermogravimetric analysis (TGA), x-ray powder diffraction (XRD) and infrared spectroscopy (IR). The particle size of 13 nm~16 nm was calculated by Scherrer's equation. The sol-gel method provides a practicable and effective route for the synthesis of the spinel compound at low temperature ($350^{\circ}C$). The kinetic parameters such as activation energy (Ea) and pre-exponential factor (A) for each compound were found by means of the Kissinger method and Arrhenius equation. The decomposition of spinel compound has an activation energy about 155 kJ/mol. Finally, the thermodynamic parameters (${\Delta}G^{\varphi}$, ${\Delta}H^{\varphi}$, ${\Delta}S^{\varphi}$) for decomposition of spinel compound was determined.

• Food Science and Preservation
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• v.10 no.2
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• pp.192-199
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• 2003

To prepare soybean curd utilizing effectively bioactive component of soybean, ultra fine whole soybean flour(UFWSF) was used as a soybean curd material for preparation of uncompressed whole soybean flour curd(UWSFC) in this study. The UWSFC was made with treatment by proteinase and coagulant, and proximate composition, color, textural properties and sensory evaluation of that were analyzed. Protease produced from Aspergillus sojae, bromelain and papain showed soybean curd coagulation ability and the pretense produced from Aspergillus sojae showed the highest soybean curd coagulation ability. When, after first heating and homogenizing, the proteinase was added to soybean milt textural properties of UWSFC were the best. Hunter's L and b values and textural properties (hardness, fracturability springiness, gumminess and chewiness) of UWSFC using proteinase and coagulant were higher than commercial soft soybean curd and adhesiveness and cohesiveness showed contrary tendency.

• Food Science and Preservation
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• v.22 no.5
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• pp.758-767
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• 2015

Red pepper powder sensitive to aflatoxins contamination is major ingredients of kimchi. This study was conducted to investigate the effect of lactic acid bacteria (LAB) on the changes in aflatoxin levels during kimchi fermentation. Baechu kimchi was contaminated with aflatoxins ($B_1$, $B_2$, $G_1$, and $G_2$) and inoculated with LAB (Lactobacillus plantarum and Leuconostoc mesenteroides), and the following characteristics were investigated for 8 weeks: pH, titratable acidity, salinity, microbial properties, and aflatoxin levels. The pH decreased rapidly during storage, and the titratable acidity was increased. The salinity of the samples was shown to increase from 2.30 to 2.40%. The total number of aerobic bacteria and lactic acid bacteria in kimchi inoculated with LAB was significantly higher than that of the others. Yeast and molds were detected at approximately 1~3 log CFU/g during storage. Coliforms were detected in the control after 4 weeks, whereas in other samples they were not detected until after 2 weeks. The aflatoxin levels reduced during kimchi fermentation. The average reduction rate of aflatoxin levels during kimchi fermentation was 8.39%, but in kimchi inoculated with Lac. plantarum and Leu. mesenteroides, the rate were 25.16 % and 27.86%, respectively. These results showed that aflatoxins can be removed by LAB during kimchi fermentation.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1604-1612
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• 1999

The study was carried out to investigate the quality of the wet noodle added with the powders of nopal and nopalitos from Opuntia ficus-indica. The wet noodles were prepared to the ratio of 3, 6 and 9% (w/w) of the nopal and the nopalitos based on a flour weight. The initial pasting temperature and final viscosity in an amylograph decreased as the increase of the nopal and the nopalitos powders. A cooked weight and volume decreased with the increase of the nopal and the nopalitos powders, while a cooking loss increased. From the sensory evaluation, the wet noodles included 3% nopalitos and 6% nopal powders were similarly evaluated as the noodle used whole wheat flour. Bacterial counts of wet noodle with the nopal and the nopalitos powders were always lower than those of the control. Bacterial counts of wet noodle slowly increased as the increase of the amount of nopal and the nopalitos powders during storage at $4^{\circ}C\;and\;20^{\circ}C$. The methanol extracts from the nopal showed antimicrobial activities against Escherichia coli, Escherichia coli O157 : H7, Salmonella typhimurium, and Bacillus subtilis, while the extracts from the nopalitos showed antimicrobial activity only against Escherichia coli.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.305-313
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• 2010

Mineralogical characteristics of Cu-Co ores from the Central African Copperbelt in the Democratic Repblic of Congo are studied using powder X-ray diffractometer, general area detector X-ray diffractometer, and electron proble microanalyzer. Black ores are mainly composed of heterogenite (cobalt oxide/hydroxide mineral) and malachite (copper carbonate mineral), whereas green ores are only composed of malachite. Heterogenite shows very bright white color under the reflected microscope, and belongs to 3R polytype, because it has d-spacings at $4.39{\AA}$ and $2.316{\AA}$. Since NiO and $Fe_20_3$ content of heterogenite are lower than those of 3R polytype from other localities, it cannot completely exclude the presence of 2H polytype in heterogenite from this study. Malachite is light grey color under the reflected microscope with approximate chemical formula of $Cu_{1.97}Co_{0.02}Fe^{2+}{_{0.01}}CO_3(OH)_2$. Heterogenite and malachite were probably formed at the supergene emichment stage, the last mineralization stage in the Central African Copperbelt. Cobalt seems to be much more emiched in the black supergene (oxy)hydroxide ore than those in the primary sulfide ore.

• Journal of the Korean earth science society
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• v.27 no.3
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• pp.313-327
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• 2006

This study investigated the geochernical characteristics of Mn scale formed in groundwater wells at the Damyang area. The composition of Mn scale consists mainly of MnO and $SiO_2$. The content of Mn ranges from56.61wt.% to 68.69wt.%, and $SiO_2$ content ranges from 1.56wt.% to 10.45wt.%. The contents of Mo and Ba in Mn scale increased with increased depth; whereas, the content of Zn and Pb decreased with increased depth. Birnessite, quartz and feldspars were identified in Mn scales using x-ray powder diffraction studies. The IR absorption bands for Mn scales show major absorption band due to OH stretching, adsorbed molecular water, and birnessite stretching, respectively. In the SEM and EDS analysis, the Mn scale consists of botryoidal, spherical, spherulite, and empty straw structure. Those structure may be precipitated simply due to oversaturation with concentrated Mn content or may be formed through biogenic precipitation by Lepthothrix discophora. Under microanalysis using EDS on those structure surface of Mn scales, the Mn atomic percent range from 28 to 44, and such elements revealed the presence of Si, K, Na, Ca, Cl, Cu, Zn, and Ba.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.141-149
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• 1997

L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders were prepared by both GNP(Glycine-Nitrate Process) and solid state reaction method in various of calcination temperature(800-1000.deg. C) and time in air. Also, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contacts on YSZ(Yttria-Stabilized Zirconia) substrate were prepared by screen printing and sintering method as a function of sintering temperature(1100-1450.deg. C) in air. Sintering behaviors have been investigated by SEM(Scanning Electron Microscope) and porosity measurement. Compositional and structural characterization were carried out by X-ray diffractometer and ICP AES(Inductively Coupled Plasma-Atomic Emission Spectrometry) analysis. Electrical characterization was carried out by the electrical conductivity with linear 4 point probe method. As the calcination period increased in solid state reaction method, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ phase increased. Although L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ single phase was obtained only for 48hrs at 1000.deg. C, in GNP method it was easy to get single and ultra-fine L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders with submicron particle size at 650.deg. C for 30min. The particle size and thickness of L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contact by solid state reaction method did not change during the heat treatment, while those by GNP method showed good sintering characteristics because initial powder size fabricated from GNP method is smaller than that fabricated from solid state reaction method. Based on enthalpy change from thermodynamic data and ICP-AES analysis, it was suggested to make cathode contact in composition of (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$ Mn $O_{3}$ which have little second phase (L $a_{2}$Z $r_{2}$ $O_{7}$) for high efficient solid oxide fuel cells applications. As (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$Mn $O_{3}$ cathode contact on YSZ substrate was sintering at 1250.deg. C the temperature that liquid phase sintering did not occur. It was possible to obtain proper cathode contacts with electrical conductivity of 150(S/cm) and porosity content of 30-40%.m) and porosity content of 30-40%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.373-377
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• 2002

We investigated the quality characteristics of eggs produced from laying hens fed with non-supplemented diets (A) and diets supplemented with 3% (B) and 5% (C) of sea urchin shell powder for efficient applications of sea urchin shell. There was no significant difference in the proximate composition. Ca and Fe contents of (B) and (C) groups were higher than those of (A) group. Contents of phosphorus and magnesium, however, showed no significant differences among the groups. (B) and (C) groups had higher in essential amino acid contents than (A) group except tryptophan. Taurine was detected in all groups. Analysis of fatty acid showed that (B) and (C) groups contained more unsaturated fatty acids. The DHA contents of (A), (B) and (C) groups were 0.56%, 0.68% and 0.89%, respectively. These results show that sea urchin shell possesses the potential as supplement of laying hens diets to produce functional eggs.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.411-420
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• 2017

In this paper, two methods of making the Pd-added $SnO_2$ ($Pd-SnO_2$) powder with pure tetragonal phase by the hydrazine method were suggested and compared in terms of crystal structure, surface morphology, and alcohol gas response. One of the addition methods is to use $PdCl_2$ as a Pd source, the other is to use Pd-based organic with oleylamine (OAM). When Pd concentration was increased from 0 to 5 wt%, the average grain size of $Pd-SnO_2$ made with Pd-OAM were decreased from 32 to 12 nm. In the case of using with $PdCl_2$, grain size of the $PdCl_2$ fell to less than 10 nm. However, agglomerated and extruded surface morphology was observed for the films with Pd addition over 4 wt%. The crack-free $Pd-SnO_2$ thick films were able to successfully fill the $30{\mu}m$ gap of patterned Pt electrodes by optimized ink dropping method. Also, the 2 wt% $Pd-SnO_2$ thick film made with PdCl2 showed gas responses ($R_{air}/R_{gas}$) of 3.7, 5.7 and 9.0 at alcohol concentrations of 10, 50 and 100 ppm, respectively. On the other hand, the prepared 3 wt% $Pd-SnO_2$ thick film with Pd-OAM exhibited very excellent responses of 3.4, 6.8 and 12.2 at the equivalent measurement conditions, respectively. The 3 wt% $Pd-SnO_2$ thick film with Pd-OAM has a specific surface area of $31.39m^2/g$.