• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.72-74
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• 2003

Rf magnetron sputtering을 이용하여 InP, GaAs 기판위에 ZnO 박막을 증착시켰다. 진공 ampul 및 $Zn_3P_2$ 분위기 하에서 열처리 과정을 통해 P와 As을 ZnO 박막내에 도핑하였으며, 박막의 전기적 특성 측정 결과 정공의 농도가 $10^{16}cm^{-3}-10^{19}cm^{-3}$ 으로서 p-형 전기전도도를 나타내었다. XRD 측정을 통하여 ZnO 박막의 내부에 이상이 존재하지 않는다는 것을 확인하였다. 또한 FESEM을 이용하여 p-형 ZnO 박막의 표면을 관찰하였으며 그 위에 n-형 ZnO 박막을 sputtering을 이용하여 증착시켜 I-V 특성을 관찰하였다. 본 실험을 통해 P 및 As의 확산을 통한 p-형 ZnO 박막의 성장이 가능하였으며, I-V 특성으로부터 ZnO의 발광소자 및 자외선 검출기로의 응용이 가능함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.306-311
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• 2002

O-linked N-acetylglucosamine (O-GlcNAc) is an abundant posttranslationally modified compound in eukaryotic cells. Human O-GlcNAc transferase (OGT) was produced as a maltose binding protein (MBP) fusion protein, which showed significant catalytic activity to modify recombinant Sp1, transcription factor. To facilitate the production of O-GlcNAc modified proteins, instead of using the tedious in vitro glycosylation reaction or expression in eukaryotic cells, a MBP-fusion OGT expression vector (pACYC184-MBPOGT) was constructed using pACYC184 plasmid, which could coexist with general prokaryotic expression vectors containing ColE1 origin. By cotransforming pACYC184-MBPOGT and pGEX-2T vectors into Escherichia coli BL21, intracellular O- GlcNAcylated proteins could be obtained by a simple purification procedure. It is expected that this may be a useful tool for production of O-GlcNAc modified proteins.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.4
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• pp.159-163
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• 2010

Co-(0.5 mol%) and Ce-(0~0.3 mol%) doped cubic zirconia ($ZrO_2:Y_2O_3$=64:36 mol%) single crystals grown by a skull melting method were heat-treated in $N_2$ at $1200^{\circ}C$ for 3 hrs. The brown-colored as-grown single crystals were changed into either green or blue color after the heat treatment. Before and after the heat treatment, the YSZ (yttriastabilized zirconia) single crystals were cut for wafer form (${\phi}7mm{\times}t2mm$) and round brilliant cut ($\phi$ 12 mm). The optical and structural properties were examined by UV-VIS spectrophotometer and X-ray diffraction. Absorption by $Ce^{3+}(^2F_{5/2},\;_{7/2}(4f){\rightarrow}^2T_g(5d^1)),\;Co^{2+}(^4A_2(^4F){\rightarrow}^4T_1(^4F)$ or $^4T_1(^4P))$ and $Co^{3+}$, change of ionization energy and lattice parameter were confirmed.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.116-122
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• 2015

Keratinocytes are first barrier against outer challenges on skin. However, it is still largely unknown about effective protectors against ultraviolet B (UVB), and oxidative stress in human keratinocyte, HaCaT cells. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a role in the pathogenesis of skin disorders. Therefore, the purpose of this study was to evaluate the effect of Portulaca oleracea 70% EtOH extracts against hydrogen peroxide (H₂O₂)-induced oxidative stress in human keratinocytes, HaCaT cells. P. oleracea 70% EtOH extracts showed the potent protective effects on H₂O₂-induced toxicity by induced the expression of HO-1 in human keratinocyte, HaCaT cells. Furthermore, P. oleracea 70 % EtOH extracts caused the nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2) in human keratinocytes, HaCaT cells. In addition, we found that treatment with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) reduced P. oleracea 70% EtOH extracts-induced HO-1 expression, and JNK inhibitor (SP600125) also inhibited protective effects by P. oleracea 70% EtOH extracts. Therefore, these results suggest that P. oleracea 70 % EtOH extracts increases cellular resistance to H₂O₂-induced oxidative injury in human keratinocyte, HaCaT cells, presumably through JNK pathway-Nrf2-dependent HO-1 expression.

• Journal of the Korean Mathematical Society
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• v.41 no.2
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• pp.265-294
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• 2004

In this paper, using a simple formula, we evaluate the conditional Fourier-Feynman transforms and the conditional convolution products of cylinder type functions, and show that the conditional Fourier-Feynman transform of the conditional convolution product is expressed as a product of the conditional Fourier-Feynman transforms. Also, we evaluate the conditional Fourier-Feynman transforms of the functions of the forms exp {$\int_{O}^{T}$ $\theta$(s,$\chi$(s))ds}, exp{$\int_{O}^{T}$ $\theta$(s,$\chi$(s))ds}$\Phi$($\chi$(T)), exp{$\int_{O}^{T}$ $\theta$(s,$\chi$(s))d${\zeta}$(s)}, exp{$\int_{O}^{T}$ $\theta$(s,$\chi$(s))d${\zeta}$(s)}$\Phi$($\chi$(T)) which are of interest in Feynman integration theories and quantum mechanics.

• Journal of the Korean Ceramic Society
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• v.41 no.5
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• pp.381-387
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• 2004

Recently developed Plasma Display Panels (PDP) require phosphors of high luminance at Vacuum Ultraviolet (VUV) excitation. The present investigation developed new PDP phosphors using combinatorial chemistry method. We applied T $b^{3+}$ -activated yttrium gadolinium phosphates system to our combinatorial fine-tuning technique. As a result, the optimum composition was determined to be (G $d_{0.74}$ $Y_{0.11}$T $b_{0.15}$) $P_{1.15}$ $O_{\delta}$ through the two-step combinatorial screening process including excess phosphorous and Gd replacement. We found that the sample of the optimum composition shows a higher luminescence efficiency at VUV excitation and a shorter decay time than the commercially available Z $n_2$ $SiO_4$:Mn phosphor.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.150-158
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• 1967

When anthracite burns by natural draft the mole percent of carbon monoxide (CO%) contained in exhaust gas is approximately expressed as follows in the early stage of combustion. (CO%)=$\frac{2{\alpha}}{1+{\alpha}}(CO_2%)$ exp $[-\vec{k}(No_2-Nc)^{1/2}{\tau}]$ where ${\alpha}=\frac{-0.395K_p+\sqrt{0.156K^2_p+(0.83+0.21K_p)K_p}}{0.83+0.21K_p}$ and $logK_p =-\frac{8593}{T} + 2.45logT -1.08{\times}10^{-3}T + 1.12{\times}10^{-7}T^2+2.77\vec{k},\;No_2$ and $N_c$ are the rate constant for the reaction ($CO+\frac{1}{2}O_2{\to}CO_2$), mole fraction of oxygen and oxides of carbon contained in the exhaust gas, respectively. From experimental evidence obtained in this work with natural draft combustion of briquettes the percent of carbon monoxide to the total quantity of oxides of carbon produced and rate of air flow into the furnace were: 1.76% and 0.53 l/sec (When lid is used in the furnace) 12.35% and 2.4 l/sec (without use of a lid). is the rate constant for the reaction($CO+\frac{1}{2}O_2{\to}CO_2$) and $N_0,\;and\;N_c$ are respectively the molefraction of oxygen and oxide of carbon contained in the exhaust gas.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.119-120
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• 2003

The experiments were conducted to investigate the effects of supplementary feather meal(FM) and its digest on the taurine content and performance of laying hens. Feeding trial was conducted with 810 78-wk-old ISA-Brown layers for 5wk. The experiment consisted of nine dietary treatments ； T1 ; control(basal diet), T2；Tl + feather meal(FM) 6 ％ diet, T3；T2 + pyridoxin(21 mg/kg) supplemented diet, T4； T1 + H$_2$O$_2$treated FM 6%, T5； T4 + pyridoxin(21 mg/kg) supplemented diet, T6； T1 + cystine(0.25 ％) supplemented diet, T7； T6 + pyridoxin(21 mg/kg) supplemented diet, T8； T1 + synthetic taurine supplemented(0.25％) diet, T9； T1 + synthetic taurine supplemented(0.5 ％) diet. Diets were formulated to be iso-caloric and to meet NRC(1994) requirements of essential nutriente. Birds in treatments T3 showed significantly higher(P＜0.01) egg production, feed intake, feed conversion ratio, egg weight, haugh unit and eggshell strength than those fed other treatments. Supplementation of FM. H$_2$O$_2$treated FM and cystine with or without pyridoxin did not significantly affected taurine content of egg yolk. Only synthetic taurine supplemented diets(T8 and T9) linearly increased(P＜0.01) taurine content of egg yolk.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.1-10
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• 2017

The aim of this study is to investigate the chemical properties and heavy metal concentration of soils in conventional and organic paddy. We sampled and analyzed topsoil (0~15 cm) and subsoil (15~30 cm) of conventional and organic paddy fields in Yongin and Anseong, South Korea. The statistical significance between groups was determined by Duncan's multiple range test and correlation between soil properties was also analyzed. The results show that organic matter (OM) and T-N of conventional paddy soil were higher than those of organic paddy soil. However, higher T-P concentration was observed in organic paddy soil than conventional paddy soil. As, Pb, and Zn concentration in organic paddy soil were statistically lower than those in conventional paddy soil. The couple of water content (WC) & As, OM & T-N, T-P & $P_2O_5$, T-P & Zn, $P_2O_5$ & Zn, and Cr & Ni had a good positive correlation but the couple of WC & T-P, WC & Zn, T-P & As, and As & Zn had a strong negative correlation. It can be concluded that organic farming is beneficial to soil environment by reducing the amounts of organic matter, T-N, As, Pb, and Zn concentration in paddy soil when compared to conventional farming.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1355-1362
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• 2010

This study was carried out in order to observe how the bay sediment would be changed with microbial treatments and a chemical oxidant like $CaO_2$. The sediment during the treatments was analyzed in terms of pH, ORP, volatile organics content, COD, AVS, T-N, and T-P. With $CaO_2$ treatment, pH was kept over 9.66 and ORP ranged from +4.70~+46.0, which meant an aerobic state meanwhile with the microbial treatment those were worse. In addition the chemical treatment showed better environmental index values than the microbial one: volatile organics content and COD values in the former were 12.9% and 37.9% while those in the latter were 4.5% and 18.7%, respectively. AVS and T-P were 71.1% and 100% versus 56.5% and 85.8%, respectively. However, the microbial treatment was better for T-N(66% higher). On the other hand, both treatment at a time enhanced all the environmental indices but COD meantime pH and ORP values were lower than with the chemical treatment only. Thus additional input of an oxygen generator like $CaO_2$ could improve the environmental state of a bay sediment where the biological treatment is going on.