• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1096-1100
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• 2013

The kinetic studies on the reactions of O-methyl (1), O-propyl (3) and O-isopropyl (4) phenyl phosphonochloridothioates with substituted anilines and deuterated anilines have been carried out in acetonitrile at $55.0^{\circ}C$. A concerted $S_N2$ mechanism is proposed for the anilinolyses of 1, 3 and 4. The anilinolysis rates of the phosphonochloridothioates are predominantly dependent upon the steric effects over the inductive effects of the two ligands. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are primary normal with 1 and 3, while secondary inverse with 4. Primary normal and secondary inverse DKIEs are rationalized by frontside and backside nucleophilic attack transition state, respectively. The DKIEs of the phosphonochloridothioates do not have any consistent correlations with the two ligands.

• The Plant Pathology Journal
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• 제15권4호
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• pp.210-216
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• 1999

TREGRO, a computer simulation model of individual tree growth, was applied to estimate ozone ($\textrm{O}_3$) effects on aspen(Populus tremuloides) growth under ambient and 1.7 times ambient $\textrm{O}_3$ of Seoul in 1996. The three highest $\textrm{O}_3$ (Kuui-dong, Ssangmun-dong, Sungsoo-dong) and the two lowest $\textrm{O}_3$ sites (Mapo-dong, Namgajwa-dong) were evaluated. The current ambient $\textrm{O}_3$ did not affect aspen growth compared to simulation without $\textrm{O}_3$. The only effect was 6.6 percent of total assimilated carbonloss at Ssangmun-dong where the level of $\textrm{O}_3$ was greatest among the 21 sites examined. Decrease as much as 50 percent of total carbon gain was calculated at 1.7 times ambient $\textrm{O}_3$ of the three highest sites. The carbon loss by $\textrm{O}_3$ came from biomass of tissues and total nonstructural cabron (TNC) such as starch and sugar. The most sensitive fraction was TNC and the next was root biomass. Foliage mass was not affected by $\textrm{O}_3$. Structural biomass loss was at best 1 to 3 percent at 1.7 times ambient $\textrm{O}_3$ at the two lowest sites. The daily carbon simulation was affected by $\textrm{O}_3$ mainly during Growth Period 4 (Jul. 21-Oct. 26). Correlations between site, dose, and the simulated responses of aspen (tissue biomass, TNC, respiration, and senescence) ranged from -0.703 to -0.973 depending on the plant responses. The ozone effects on poplar in Seoul are not severe currently, but are probably measurable at Ssangmun-dong. However, severe $\textrm{O}_3$ effects on biomass would occur if $\textrm{O}_3$ levels increase to 1.7 times ambient $\textrm{O}_3$ in Seoul. In addition, v could weaken the trees thus increasing susceptibility to pathogens or insects.

• 한국세라믹학회지
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• 제34권1호
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• pp.63-69
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• 1997

출발원료로서 소결마그네시아 클링커 및 천연크롬철광을 사용하여 Cr2O3의 함유량을 약 10-30 중량%의 범위에서 변화시켜 직접결합 마그네시아-크로미아질 내화벽돌의 특성에 미치는 Cr2O3의 영향을 고찰하였다. 상온 꺾임강도 및 고온 꺽임강도는 Cr2O3의 함유량 및 flux 성분의 함유량과는 상관관계가 성립하지 않았으며, 상온 꺾임강도 및 고온 꺾임강도가 가장 우수한 Cr2O3 함유량의 범위는 20중량% 전후였다. 내식성을 좌우하는 주된 요인은 flux성분의 함유량보다는 2차 spinel의 생성량이었으며, 내식성은 2차 spinel의 생성량 증가에 따라 선형적으로 증가하였다. 또한, 내spalling성은 주로 flux 성분의 함유량에 의존하였으며, flux 함유량이 적을수록 내spalling성이 우수하였다.

• 한국재료학회지
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• 제14권2호
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• pp.115-120
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• 2004

Perovskite barium-strontium titanate, $(Ba, Sr)TiO_3$ was prepared and effects of $Sb_2$O$_3$ additives on its PTCR properties were investigated. $The (Ba,Sr)TiO_3$ with 0.05～0.25 mol% $Sb_2$$O_3$ showed semiconducting PTCR behavior and anomalous grain growth was also observed when it was sintered above $1330^{\circ}C$. It was considered that charge compensation by doping 8b203 as well as abnormal grain growth by sintering lead to resistivity reduction from insulating to semiconducting transition.

• 한국세라믹학회지
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• 제24권6호
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• pp.579-585
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• 1987

The effects of flux KCl and dopant Nb2O5 on the PTCR characteristics of BaTiO3 prepared by molten salt synthesis method have been investigated. As the amount of dopant Nb2O5 is over the solubility limit in BaTiO3, the room-temperature resistivity increases, and the PTCR effect and the grain size decrease. The variation of the amount of flux KCl slightly influences on the room-temperature resistivity, PTCR effect and grain size in Nb2O5 doped BaTiO3, but BaTiO3 ceramics prepared by the method of molten salt synthesis show larger PTCR effect than those of conventional calcining of mixed oxides.

• 대한임상검사과학회지
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• 제50권2호
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• pp.170-176
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• 2018

본 연구 목적은 산수유 추출물의 항산화 효과를 배양 C6 glioma 세포를 대상으로 조사하였다. 이 같은 목적을 위하여 C6 glioma 세포를 48시간 동안 배양한 후 6가 크롬의 세포독성 및 산수유 추출물의 방어효과를 조사하였다. 이외에 EDA 및 LDH 활성과 같은 항산화 효과를 분석하였다. 본 연구에서 $CrO_3$는 처리농도에 비례하여 세포생존율을 감소시켰다. 또한 이 과정에서 세포를 48시간 동안 20~40 uM로 각각 포함된 배양액에서 처리한 결과 $XTT_{50}$ 값은 33 uM로 나타났다. 항산화제인 CAT는 $CrO_3$로 유도된 세포독성에 의해 감소된 세포생존율을 유의하게 증가시켰다. 한편 산수유 추출물의 보호효과에 있어서, 산수유 추출물은 $CrO_3$만의 처리군에 비하여 세포생존율을 유의하게 증가시켰다. 동시에 산수유 추출물은 EDA와 LDH 활성과 같은 항산화 효과를 보였다. 이와 같은 결과로부터 $CrO_3$의 독성에 산화적 손상이 관련되어 있는 것으로 나타났다. 또한 산수유 추출물은 이의 항산화 효과에 의하여 $CrO_3$의 세포독성을 효과적으로 방어하였다. 결론적으로, 산수유 추출물과 같은 천연소재는 산화적 손상과 관련된 중금속에 의해 유발된 세포독성을 방어 내지는 치료하는데 유용한 치료적 요소의 하나로 생각된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.141-141
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• 1994

• 한국세라믹학회지
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• 제32권9호
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• pp.1056-1064
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• 1995

95Pb(Mg1/3Nb2/3)O3-5PbTiO3 (hereinafter designated as 95PMN-5PT) system was prepared by the columbite-precursor method with 2 mol% excess PbO to compensate the PbO loss during thermal process. The amount of CuO was 1~10 mol%, and the effects of CuO addition on the dielectric properties of this system have been investigated. From the microstructures, XRD analysis and dielectric measurements, the solubility limit of CuO in 95PMN-5PT was found to be around 3 mol%. Lattice parameter and Curie temperature were found to be decreased as the amount of CuO increased up to the solubility limit. This result confirmed that the Cu2+-ions substituted the Pb2+-ions. It was revealed that the addition of CuO on 95PMN-5PT promoted the sinterability and properties. The room temperature dielectric constant, the loss factor and the specific resistivity of the specimens processed with optimum conditions were 23000, 1%, and 8$\times$1011Ω.cm, respectively.

• 대한한의학회지
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• 제18권1호
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• pp.208-217
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• 1997

Experimental studies were done to research the clinical effect of Banhaonpyetang and Banhaonpyetanggarnibang estimated the level of $pO_2,\;pCO_2$, and pH, the concentration of $HCO_{3}-ion$, the lung TBA(thiobarbituric acid) values in blood and oxygen consumption values in blood in $O_{3}-intoxicated$ rats. The results were obtained as follows. 1. Both Banhaonpyetang and Banhaonpyetanggamibang revealed the increasing effect with statistically significant on the blood $pO_2$ level in $O_{3}-intoxicated$ rats 2. Both Banhaonpytang and Banhaonpyetanggarnibang revealed the decreasing effect with statistically significant on the blood $pO_2$ level in $O_{3}-intoxicated$ rats 3. Both Banhaonpyetang and Banhaonphetanggarnibang revealed the decreasing effects with statistically significant on the blood $HCO_{3}level$ in $O_{3}-intoxicated$ rats. 4. Both Banhaonpyetang and Banhaonpyetanggamibang revealed the increasing effects with statistically significant on the blood pH level in. $O_{3}-intoxicated$ rats. 5. Both Banhaonpyetang and Banhaonpyetanggamibang revealed the decreasing effects with statistically significant on the Oxygen consumption values in $O_{3}-intoxicated$ rats. 6. Both Banhaonpyetang and Banhaonpyetanggamibang revealed the decreasing effects with statistically significant on the Lung TBA values in $O_{3}-intoxicated$ rats. According to the above findings, it is suggested that Banhaonpyetang and Banhaonpyetanggamibang retain effectiveness on the lung damages and can be used for treatment of respiratory disease.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
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• pp.98-98
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• 1992