• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.6
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• pp.30-37
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• 1989

The PIN type a-SiC:H/a-Si:H heterojunction solar cells were fabricated by using the rf glow discharge decomposition of $SiH_4$ mixed with $CH_4,B_2,H_6\;and\;PH_3.$ The efficiency of the solar cell of the $SnO_2/ITO$ was higher than that of ITO transparent oxide layer by 1.5%. The P layer was prepared with the thickness of $100{\AA}$ and $CH_4/SiH_4$ ration of 5. The I layer has been deposited on the P layer and it is not pure intrinsic but near N type. So $SiH_4$ mixed with $B_2H_6$ of 0.3ppm was used to change this N type nature to intrinsic having the thickness of 5000${\AA}$. And consecutively, the N layer was deposited with t ethickness of $400{\AA}$ using $SiH_4/PH_3$ mixtures. The solar cell demonstrated 0.94V of $V_{oc'}$ 14.6mA/cm of $J_{sc}$ and 58.2% of FF, resulting the efficiency of 8.0%. To minimize loss by the reflection of light, $MgF_2$ layer was coated on the lgass and the efficiency was improved by 0.5%. Therefore, the solar cell indicated overall efficiency of 8.5%.

• Journal of the Mineralogical Society of Korea
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• v.14 no.2
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• pp.128-136
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• 2001

The K-Ba complete solid solution of 7 synthetic hollandite-type minerals ($K_{2x}$ $Ba_{1-x}$ $Cr_2$/$Ti_{6}$ $O_{16}$ , x=0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0, respectively) are studied by the X-ray powder diffraction and Rietveld refinement to find structural transformation during substitution of $Ba^{2+}$ by $K^{+}$ in A site of the tunnel structure of hollandite. Rietveld indices indicate that $R_{wp}$ with respect to $R^{exp}$ ($R_{wp}$ $R_{exp}$ ) are in the range of 15.66%/20.90% and 14.74%/l9.37%, $R_{B}$ and S(Goodness of Fitness) are 6.45~8.97%, 1.45~1.63, respectively. Unit cell parameters of synthetic hollandites, space group 14/m, are a=10.1194(2)~10.0599(2)$\AA$, c=2.9572(6)~2.9512(7)$\AA$, and V=302.75~298.66$\AA^{3}$. Rutile formed as an impurity in those with more than 50% K contents in hollandite series. Substitution of Ba by K ion in a tunnel structure results in constant decrease of cell parameters, but is not sufficient enough to change the hollandite structure. Our data indicate that transformation of tetragonal 14/m to lower symmetry of monoclinic 12/m in hollandite structure may at least be affected by other cation substitution in same A site and/or by cation substitution in B site.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.100-105
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• 2000

Anionic peroxidases (POD) were isolated from Korean radish (Raphanus sativus L.) root by using fractionation with $(NH_4)_2SO_4$ and CM-cellulose ion exchange chromatography and used as the colorimetric enzyme for glucose determination. The chromogen used in this work was o-tolidine or 4-aminoantipyrine/diethylaniline (4AA/DEA) and the colored products were measured at 630 nm. Korean radish anionic POD showed much better colorimetric reaction of glucose determination with 4AA/DEA than with o-tolidine. The r values of calibration curve for glucose determination by o-tolidine and 4AA/DEA were 0.9983 and 0.9963, respectively. In order to compare the reactivity for substrate oxidation by Korean radish POD and horseradish POD, the Km values against o-dianisidine and guaiacol were measured. Korean radish POD had about 40 fold higher affinity for o-dianisidine and 2 fold higher affinity for guaiacol as revealed by Km values. These results showed that Korean radish POD could be developed as the colorimetric diagnosis reagent for glucose determination with high sensitivity.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2363-2368
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• 2007

A glassy carbon electrode (GCE) modified with phytic acid (PA) and single-walled carbon nanotubes (SWNTs) were investigated by voltammetric methods in buffer solution. The PA-SWNTs/GCE-modified electrode demonstrated substantial enhancements in electrochemical sensitivity and selectivity towards dopamine (DA) in the presence of L-ascorbic acid (AA). The PA-SWNTs films promoted the electron transfer reaction of DA, while the PA film, acting as a negatively charged linker, combined with the positively charged DA to induced DA accumulation in the film at pH under 7.4. However, the PA film restrained the electrochemical response of the negatively charged AA due to the electrostatic repulsion. The anodic peak potentials of DA and AA could be separated by electrochemical techniques, and the interferences from AA were effectively eliminated in the DA determination. Linear calibration plots were obtained in the DA concentration range of 0.1-10 μM and the detection limit of the DA oxidation current was determined to be 0.06 μM at a signal-to-noise ratio of 3. The results indicated that the modified electrode is used to determine DA without interference from AA.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.590-593
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• 2007

The textural properties of doughs mixed with L-ascorbic acid (AA), trypsin hydrolyzed gluten peptide (THGP), and a mixture of AA-THGP were investigated using texture analyzer under the fermentation of the full formula and the freezing process. The full formula dough (FFD) required a shorter mixing time than the flour and water formula dough (FWD). The maximum resistance (Rmax) values of both the unfrozen and frozen doughs were lower for the FFD. The effects of AA and THGP additions were not significant (p<0.01) in FFD, however, they were significant in FWD. The freezing effect was significant (p<0.0001) for FFD, indicating that yeast fermented dough was much more sensitive to damage from freezing, which subsequently affected dough strength. Additions of AA (p=0.0026) and THGP (p=0.0097) had a significant effect on the extensibility (E-value) of unfrozen FWD, where THGP increased and AA decreased the E-value. However, freezing did not significantly effect the extensibilities of FWD (p=0.64) or FFD (p=0.21). The area of FFD was lower than the area of FWD for both the unfrozen and frozen doughs. However, the frozen dough mixed with THGP alone had the largest area overall. The addition of additives did not result in significantly different (p<0.01) areas under the curve, except in the frozen FFD. Freezing caused a statistically significant difference in the area of FWD (p=0.0045).

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.315-327
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• 2002

Al-pillared clay was synthesized by constructing pillars of aluminum oxides at the interlayer of montmorillonite in bentonite. XRD, DTA and chemical analyses of Al-pillared clay were performed to examine mineralogical properties. Batch adsorption experiments were also conducted to determine the adsorption properties of this synthesized clay for phosphate ions. XRD analyses showed that the interlayer space of Al-pillared clay expanded to 18.03 $\AA$ at room temperature and shifted to $17 \AA$ after heating to $550^{\circ}C$. A small change in interlayer space after heating indicates high thermal stability. The interlayer expansion by glycerol was also very small. From DTA analyses, pillared clay showed the characteristic endothermic peaks at 270 and $420^{\circ}C$ , which might be caused by dehydration in framework of pillars between interlayers. Adsorption experiment revealed that Al-pillared clay had an excellent adsorption capacity to the phosphate ions, whereas montmorillonite had very low adsorption capacity to phosphate ions. In phosphate solution concentration up to 300 mg/L, 2 g of pillared clay could uptake almost 100% of phosphate ions from 20 mL of solution. After heat treatment of the phosphate adsorbed pillared clay at 50$0^{\circ}C$ to remove phosphate, the calcined pillared clay could adsorb phosphate ions with a little decreased adsorption efficiency. This fact indicates that Al-pillared clay can be recycled for the adsorption of phosphate ions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.490-495
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• 2009

This study investigated the changes of physicochemical characteristics and antioxidant activity of heated radish (Raphanus sativus L.). Raw radish was heated at various temperatures ($110{\sim}150^{\circ}C$) for 2 hr. The heated radish was extracted with 70% ethanol and then fractionated with hexane, ethyl acetate, and aqueous. Total polyphenol contents, $IC_{50}$ value of electron donating ability (EDA), and total antioxidant activity (AEAC) increased with increasing heating temperature. The maximum total polyphenol content was $256.26{\pm}9.61$ mg/100 g at $150^{\circ}C$ (control: $27.90{\pm}1.28$ mg/100 g), $IC_{50}$ value was $1.34{\pm}0.004$ mg/mL at $150^{\circ}C$ (control: $34.93{\pm}0.039$ mg/mL), and AEAC was $53.10{\pm}1.155$ mg AA eq/g at $150^{\circ}C$ (control: $6.721{\pm}0.122$ mg AA eq/g). The ethyl acetate fraction showed higher total polyphenol contents and stronger antioxidant activities than hexane and aqueous fractions. Total polyphenol content was 133.62 mg/100 g (at $140^{\circ}C$), $IC_{50}$ values of EDA and AEAC content were 0.39 mg/mL (at $150^{\circ}C$) and 183.72 mg AA eq/g (at $140^{\circ}C$), respectively.

• Journal of Embryo Transfer
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• v.10 no.1
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• pp.53-63
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• 1995

The effects of different protein sources (serum vs bovine serum albumin), growth factors (EGF and PDGF) and co-culture with various type of somatic cel1s (BOEC, MEF and BRL) on the in vitro development of in vitro matured / in vitro fertilized bovine oocytes were examined, and the viability of frozen/thawed embryos derived from IVM /IVF was examined. Cell numbers of blastocysts were also counted. In Experiment 1, CR$_1$aa with serum was superior to CR$_1$aa with BSA in producing morulae plus blastocysts from IVM /IVF oocytes(24.4% vs 30.4%, p>0.05). In Experiment 2, more morulae plus blastocysts(42.3%) were produced in CR$_1$aa containing long /ml EGF than in the control CR$_1$aa(33.3%). In Experiment 3, 2- to 8-cell embryos derived from IVM /IVF oocytes were randomly allotted to one of 4 culture groups : a) CR$_1$aa ; b) CR$_1$aa + ing /ml PDGF ; CR$_1$aa + Sng /ml PDGF ; CR$_1$aa + lOng /ml PDGF ; culture resulted in 21.3, 51.2, 41.4 and 45.9%(p<0.05), respectively, developing into morulae and blastocysts. In Experiment 4, 0 and Sng /ml PDGF added to CR$_1$aa coculture with BRL or BOEC yielded 47.5, 42.5, 33.8 and 41.6% morulae and blastocysts, respectively. In Experiment 5, the proportion of embryos into morulae and blastocysts was highest in CR$_1$aa with MEF coculture group(50.9%) compared to any other group(CR$_1$aa, 22.3%; CR$_1$aa+BRL, 32.9%; CR$_1$aa+BOEC, 33.8%, p>0.05). In Experiment 6, survival rate of blastocysts produced by in vitro fertilization when cryoprotectant was removed in 0.7M glycerol+0.7M sucrose and 0.7M sucrose solution for 10 min. after thawing at 2$0^{\circ}C$ (Exp. H, 58.8%) was slightly higher than when cryoprotectant was removed 10%, 6.7% and 3.3% glycerol for 10 min. after thawing at 37$^{\circ}C$ (Exp. I, 54.3%). These study indicate that growth factors and somatic cell co-culture can increase the proportion of embryos that develop into morulae and blastocysts without an increase in the cell number and frozen /thawed method employed this experiment was not different.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.535-537
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• 2023

We report the draft genome sequence of Bacillus thuringiensis serovar aizawai AS23, an insecticidal strain targeting lepidopteran pests, which was isolated from the rhizosphere of Korean melon (Cucumis melo L.). The genome of strain AS23 comprising 6,846,584 bp with a G + C content of 34.83% was assembled to 11 contigs obtained using hybrid assembly. Additionally, we mined the genome for pesticidal genes, identifying several insecticidal genes, including Cry1Aa3, Cry1Ca9, Cry1Da2, Cry1Ia44, Cry2Ab41, Cry9Ea9, Spp1Aa1, and Vip3Aa86.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1422-1428
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• 2000

This investigation was conducted to evaluate the shrimp flesh (SF) and shrimp by-product (SB) of the most abundant shrimp species (Metapenaeus affinis, Penaeus semisulcatus and Penaeus monodon) caught in Central Vietnam, with the emphasis on yield, gross and amino acid (AA) composition and effect of heat treatment. The results showed that the mean edible SF and SB (head and shells with tail) yields of the three shrimp species averaged 56.7 and 43.3%, respectively, of the total wet body weight, with the M. affinis generating the highest by-product yield (45.7%) and P. semisulcatus (40.6%) the lowest. Significant differences in dry matter (DM), crude protein (CP) and ash content were found between SF and SB. The DM content of SF (21.5%) was lower than of SB (24.9%) and the ash content (on a DM basis) of the SB in all shrimp species was more than three times that of the SF (p<0.05), whereas the CP content was almost twice as high in the SF as compared with the SB (p<0.05). The SB of the three species contained (on a DM basis) between 44.0 and 49.8% CP (p<0.05) and between 13.5 and 18.1% chitin (p<0.05). The Ca content of SB differed also between species (p<0.05). On average, the sum of AA in SB corresponded to 89.3% of the CP and essential AA accounted for about 50% of the total AA. The most abundant AA were arginine, aspartic and glutamic acids, which accounted for 33% of the total AA. Minor, but significant differences in some AA concentrations of SB between species were observed (p<0.05). With the exception of the DM and ether extract content, all other chemical constituents of entire shrimp, SF and SB were not significantly affected by heat treatment (p>0.05).