• KSBB Journal
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• v.17 no.6
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• pp.586-589
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• 2002

Lipomyces starkeyi KSM 22 produces dextranase and amylase (DXAMase). The addition of 0.02％ (w/v) 2-deoxy-D-glucose or 0.5% (w/v) glycerol into a 1% (w/v) starch medium increased the final activity of DXAMase produced 2.5 fold or 2.4 fold, respectively, compared to that of a 1% (w/v) starch medium. This activity was similar to that produced with 1% (w/v) dextran. The stability of purified OXAMase at 40$\^{C}$ for 3 weeks was tested using the various enzyme stabilizers. With the addition of 25% (v/v) glycerol, 90.9% of initial activity was left after 3 weeks. For practical use, the addition of 1% (v/v) glycerol with 50 mM of CaCl$_2$ or KH$_2$PO$_4$was adequate and maintained 73.4% of the initial activity under the test conditions used.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.182-186
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• 2014

Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of $60mA/cm^2$. The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was $4.44{\sim}5.00{\Omega}{\cdot}cm^2$ and $3.28{\sim}3.75{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was $4.19{\sim}4.42{\Omega}{\cdot}cm^2$ and $4.71{\sim}5.49{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

• Journal of the Korean Ceramic Society
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• v.35 no.12
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• pp.1329-1336
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• 1998

A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

• Journal of Sericultural and Entomological Science
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• v.9
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• pp.21-25
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• 1969

Various formulae for estimation of leaf production in mulberry trees were investigated and obtained. Four varieties of mulberry trees were used as the materials, and four characters. namely branch length (X, 1). branch diameter (X, 2). leaf number per branch (X, 3), and leaf area per branch (X, 4). were studies. The formulae to eatimate the leaf yield of mulberry trees are as follows: 1. Y$_1$v$_1$＝-115.760＋0.068X$_1$＋165.756X$_2$ Y$_1$v$_2$＝-221.500＋1.768X$_1$＋38.152X$_2$ Y$_1$v$_3$＝-253.826-0.116X$_1$＋289.507X$_2$ Y$_1$v$_4$＝ -157.559＋1.063X$_1$＋106.088X$_2$ where Y$_1$v$_1$, Y$_1$v$_2$, Y$_1$v$_3$, Y$_1$v$_4$, are showed the estimated yield of the each variety, namely Gaeryang souban, Ilchirye, Nosang. and Suwon Sang No. 4, respectively. X$_1$ and X$_2$ denote the measured values of branch length and branch diameter, respectively. 2. Y$\sub$7/v$_1$＝-118.478-0.665X$_1$＋184.445X$_2$＋2.346X$_3$ Y$\sub$7/v$_2$＝-217.432＋2.062X$_1$＋35.668X$_2$-1.058X$_3$ Y$\sub$7/v$_3$＝-206. 249-0.739X$_1$＋268.08X$_2$＋2.770X$_3$ Y$\sub$7/v$_4$＝-153.383＋0.009X$_1$＋2.024X$_2$＋0.171X$_3$where Y$\sub$7/v$_1$, Y$\sub$7/v$_2$, Y$\sub$7/v$_3$, Y$\sub$7/v$_4$, are the estimated yield of the each variety, namely Gaeryang. Souban, Ilichirye, Nosang, and Suwon Sang No. 4, respectively. X$_1$, X$_2$, X$_3$, denote the measured values of each character. branch length, branch diameter and leaf number per branch, respectively. 3. Y$\sub$11/v$_1$＝82. 567-1.283X$_1$＋15.501X$_2$＋0.640X$_3$＋3.511X$_4$ Y$\sub$11/v$_2$＝136.411＋0.311X$_1$＋1.921X$_2$-0. 217X$_3$＋0.214X$_4$ Y$\sub$11/v$_3$＝150.2Z7-0.139X$_1$＋11.788X$_2$＋0.143X$_3$＋0.381X$_4$ Y$\sub$11/v$_4$＝160.850＋0.323X$_1$＋66.076X$_2$-0.794X$_3$＋2..614X$_4$ where Y$\sub$11/v$_1$, Y$\sub$11/v$_2$, Y$\sub$11/v$_3$, Y$\sub$11/v$_4$, are the estimated yield values of four varieties, and X$_1$, X$_2$, X$_3$, X$_4$ denote the measured values of four characters. namely branch length, branch diameter. leaf number per branch and leaf area per branch. respectively. The estimation method of mulberry leaf yield by measurement of some characters, branch length. branch diameter. leaf number per branch and leaf area per branch. could be the better method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees than the other methods.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.581-588
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• 2007

To enhance the photodecomposition of concentrated ammonia into N2, Pt/V-TiO2 photocatalysts were prepared using solvothermal and impregnation methods. Nanometer-sized particles of 0.1, 0.5 and 1.0 mol% V-TiO2 were prepared solvothermally, and then impregnated with 1.0 wt% Pt. The X-ray diffraction (XRD) peaks assigned to V2O5 at 30.20 (010) and Pt metal at 39.80 (111) and 46.20 (200) were seen in the 1.0 wt% Pt/ 10.0 mol% V-TiO2. The particle size increased in the order: pure TiO2, V-TiO2 and Pt/V-TiO2 after thermal treatment at 500 °C, while their surface areas were in the reverse order. On X-ray photoelectron spectroscopy (XPS), the bands assigned to the Ti2p3/2 and Ti2p1/2 of Ti4+-O were seen in all the photocatalysts, and the binding energies increased in the order: TiO2 < Pt/V-TiO2 < V-TiO2. The XPS bands assigned to the V2p3/2 (517.85, 519.35, and 520.55 eV) and V2p1/2 (524.90 eV) in the V3+, V4+ and V5+ oxides appeared over V-TiO2, respectively, while the band shifted to a lower binding energy with Pt impregnation. The Pt components of Pt/ V-TiO2 were identified at 71.60, 73.80, 75.00 and 76.90 eV, which were assigned to metallic Pt 4f7/2, PtO 4f7/2, PtO2 4f7/2, and PtO 4f5/2, respectively. The UV-visible absorption band shifted closer towards the visible region of the spectrum in V-TiO2 than in pure TiO2 and; surprisingly, the Pt/V-TiO2 absorbed at all wavelengths from 200 to 800 nm. The addition of vanadium generated a new acid site in the framework of TiO2, and the medium acidic site increased with Pt impregnation. The NH3 decomposition increased with the amount of vanadium compared to pure TiO2, and was enhanced with Pt impregnation. NH3 decomposition of 100% was attained over 1.0 wt% Pt/1.0 mol% V-TiO2 after 80 min under illumination with 365 nm light, although about 10% of the ammonia was converted into undesirable NO2 and NO. Various intermediates, such as NO2, -NH2, -NH and NO, were also identified in the Fourier transform infrared (FT-IR) spectra. From the gas chromatography (GC), FT-IR and GC/mass spectroscopy (GC/MS) analyses, partially oxidized NO and NO2 were found to predominate over V-TiO2 and pure TiO2, respectively, while both molecules were reduced over Pt/V-TiO2.

• Kyungpook Mathematical Journal
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• v.56 no.2
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• pp.577-582
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• 2016

In this paper we consider all orientation-preserving ${\mathbb{Z}}_4$-actions on 3-dimensional handlebodies $V_g$ of genus g > 0. We study the graph of groups (${\Gamma}(v)$, G(v)), which determines a handlebody orbifold $V({\Gamma}(v),G(v)){\simeq}V_g/{\mathbb{Z}}_4$. This algebraic characterization is used to enumerate the total number of ${\mathbb{Z}}_4$ group actions on such handlebodies, up to equivalence.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.788-794
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• 2009

To assess the condition of stator insulation, nondestructive tests were performed on twenty five coil groups and twenty six motors. The stator windings has nominal ratings of 6.6kV and are classified into five coil groups ;one group with healthy insulation and four groups with four different types of artificial defects. After completing nondestructive tests, the AC voltage applied to the stator windings was gradually increasing until insulation failure in order to obtain the breakdown voltage. No.1, No.2 and No.6 of 6.6kV motors failed near rated voltage of 14kV, 8.7kV and 14kV, respectively. The breakdown voltage of three motors was lower that expected for good quality coils(14.2kV) in 6.6kV motors. No.3 and No.6 of 4.16kV motors failed near rated voltage of 5.6kV and 4.2kV, respectively. Almost all of failures were located in a line-end coil at the exit from the core slot. The breakdown voltages and the types of defects showed strong relation to the stator insulation tests such as in the case of AC current, dissipation factor(tan${\delta}$) and partial discharge magnitude.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.4
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• pp.284-288
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• 2002

The authors examined the response of electrocardiogram (ECG) to Mirror carp, Cyprinus carpio of body length. The experiments were performed of three classes (10~15, 15~20 and 20~25cm) were given to fishes with an electrode inserted into their bodies and then their ECGs were recorded continuously for 30 minutes in 16-18$^{\circ}C$. The results which are divided into by day and by night and then analyzed by fishes' conditions are as follows; 1 In case of body length 10~15 cm, the average heart rate 43.4 beat/min by day and 45.9 beat/min by night, the average action potential 4.38 $mutextrm{V}$ by day and 3.64 $mutextrm{V}$ by night, in narcotism condition(0~9 min). the average heart rate 69.4 beat/min by day and 67.4 beat/min by night, the average action potential 3.82 $mutextrm{V}$ by day and 3.50 $mutextrm{V}$ by night, in stable condition(9~30 min). 2. In case of body length 15～20 cm, the average heart rate 42.2 beat/min by day and 45.4 beat/min by night, the average action potential 4.13 $mutextrm{V}$ by day and 3.95 $mutextrm{V}$ by night, in narcotism condition(0-5 min). the average heart rate 67.6 beat/min by day and 65.3 beat/min by night, the average action potential 4.58$mutextrm{V}$ by day and 4.61 $mutextrm{V}$ by night, in stable condition (5~30 min). 3. In case of body length 20～25 cm, the average heart rate 47.5 beat/min by day and 47.5 beat/min by night, the average action potential 4.81 $mutextrm{V}$ by day and 4.20 $mutextrm{V}$ by night, in narcotism condition(0-4 min). the average heart rate 67.5 bea/min by day and 64.8 beat/min by night, the average action potential 5.31 $mutextrm{V}$ by day and 4.90 $mutextrm{V}$ by night, in stable condition (4~30 min).

• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.532-537
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• 1986

The kinetics of the reaction of $[Mo_2O_4(H_2O)_6]^{2+}$ with $VO_2^+$ have been studied at $25^{\circ}C$ by spectrophotometric method. Stoichiometry of the oxidation of$ [Mo_2O_4(H_2O)_6]^{2+}$ is followed as $Mo_2^V + 2V^V {\rightleftharpoons} 2Mo^{VI} + 2V^{IV}$. Observed rate constants are dependent on $ [H^+]\;and\;[VO_2^+]$. Mechanism for the redox of $[Mo_2O_4(H_2O)_6]^{2+}\;and\;VO_2^+$ is proposed and discussed.

• Journal of fish pathology
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• v.19 no.1
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• pp.35-43
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• 2006

To analyze the safety of shellfish from the Vibrio vulnificus contamination, we investigated the multiplication of V. vulnificus in oysters keeping at different temperatures with or without shell. The numbers of V. vulnificus contaminated in oysters were more than that in artificial sea water (ASW) after artificial infection. The storage-temperature had an effect on multiplication of V. vulnificus in oysters, because the number of V. vulnificus was started to increase rapidly from just after keeping at 25℃ but no significant variation was observed at 4℃ throughout the experiment periods. In different salinity, using ASW of 5, 15, 35 ‰, the number of V. vulnificus was decreased at both 25℃ and 4℃. However, the rate of decreasing at 4℃ was faster than that 25℃. Additional, changed salinity also influenced to the decreasing rate of V. vulnificus keeping 4℃ as the highest rate in 35 ‰ ASW.