• Journal of Information Display
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• 제2권3호
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• pp.13-17
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• 2001

The manganese-doped magnesium tin oxide with spinel structure was selected as a green phosphor for FED application and was synthesized by the solid state reaction. Its luminescence properties were investigated under low-voltage electron excitation. The $Mg_2SnO_4$:Mn phosphor showed green emission with the spectrum centered at 500 nm due to energy transfer from $^4T_1$ to $^6A_1$ of $Mn^{2+}$ ion. Optimum Mn concentration was 0.6 mole % and the decay time was shorter than 10 ms.

• 한국식품과학회지
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• 제25권2호
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• pp.165-170
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• 1993

현재 국내에서 유통되고 있는 캔 오렌지 쥬스의 중금속(Pb, Sn) 함량과 쥬스의 개봉 저장중 이들 중금속의 함량변화를 습식 분해 후 추출과정을 거쳐 원자흡광광도계로 분석하였다. 오렌지 쥬스 53개 시료중 중금속의 평균농도는 Pb 0.225 mg/kg, Sn 40.7 mg/kg이었다. 쥬스의 유통기간 경과에 따라 Pb 농도는 거의 증가하지 않았으나 Sn 농도는 한달이 경과할 때마다 평균 0.66 mg/kg씩 증가하는 것으로 나타났다. 개봉한 시료를 그대로 실온과 냉장고에 보관한 결과 Pb 농도는 7일 경과 후에 저장 전의 $1.7{\sim}1.8$배로 증가하였고 Sn 농도는 1일 평균 20%씩 증가하여 7일 경과 후에 저장 전의 악 3배로 증가하였다. 또한 개봉한 시료를 유리 용기에 옮겨 담아 실온과 냉장고에 보관한 결과 Pb와 Sn 농도는 저장기간 중 큰 변화가 없었다. 결론적으로 보아 유통되고 있는 캔 오렌지 쥬스는 권장 유통기한 이내의 제품에서도 Pb 함량이 법적 기준을 초과하는 빈도가 18%나 되므로 생산 공정 또는 유통 기간 중의 규제용 검색을 강화해야 될 것이며 캔 오렌지 쥬스를 개봉한 후에는 Pb나 Sn의 농도가 크게 증가하므로 사용상의 주의를 필요로 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.114-115
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• 2007

In this study, low temperature sintering property of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with sintering adds were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_3O_8$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_3O_3$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. In the case of $H_3BO_3$ addition, the bulk density and dielectric constant were decreased but quality factor was increased with amount of $H_3BO_3$ additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3+xwt%H_3BO_3$ ceramics were moved to positive direction. In another case, SnO addition, the bulk density and dielectric constant were increased but Quality factor was decreased with amount of SnO additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$+ywt%SnO ceramics were shifted to negative direction. The dielectric constant, quality factor and TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with $2wt%H_3BO_3$ and 2.5wt%SnO sintered at $830^{\circ}C$ for 1h, were 28.5, 39,570GHz, $+9.34ppm/^{\circ}C$ and 29.86, 35,80000z, $-0.58ppm/^{\circ}C$, respectively.

• 대한금속재료학회지
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• 제47권12호
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• pp.797-810
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• 2009

A study was made of the effects of a Sn addition on the microstructure and microfracture mechanism of squeeze cast AZ51-xSn magnesium alloys. Microstructural observation, in situ fracture testing, and fractographic observations were conducted on these alloys to clarify the microfracture process. The microstructural analyses indicated that $Mg_2Sn$ particles as well as $Mg_{17}Al_{12}$ particles precipitated mainly along the solidification cell boundaries; the volume fraction of these hard particles increased as the amount of added Sn increased, with increased the strength. From in situ fracture observations of the AZ51-7Sn alloy, coarse precipitates located on the cell boundaries worked as easy crack propagation sites and caused abrupt intercellular fracturing. On the other hand, the overall fracture properties of the AZ51-3Sn alloy improved because crack propagation proceeded into the Mg matrix rather than into the cell boundaries as twins developed actively, as confirmed by an R-curve analysis. These findings suggest that the addition of 3~5 wt.% Sn is effective in improving both the tensile and fracture properties on the basis of well-developed twins, the blocking of crack propagation, and crack blunting.

• 한국지역사회생활과학회지
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• 제27권3호
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• pp.437-449
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• 2016

To provide information on the safety of crude antifungal compounds produced by Bacillus subtilus SN7 isolated from Meju, we carried out an acute (single) oral dose toxicity test and 4 week repeated oral dose determination test on crude antifungal compounds in male and female Sprague Dawley rats. In the acute toxicity test, rats were treated with crude antifungal compounds produced by Bacillus subtilus SN7 orally at increasing dose levels (500, 1,000, and 2,000 mg/kg) and observed for 2 weeks. In the repeated-dose 28-day oral dose determination study, rats were orally administered doses of 500, 1,000, and 2,000 mg/kg daily for 4 weeks. There were no test article-related deaths or abnormal clinical signs in the two studies. In the 4 week repeated oral dose determination test, there were also no significant differences in clinical signs, body and organ weight changes, or any other hematological and biochemical parameters between the control and treated groups. The results suggest that the crude antifungal compounds produced by Bacillus subtilus SN7 up to a dosage level of 2,000 mg/kg are not toxic in male and female rats.

• 공업화학
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• 제5권2호
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• pp.327-336
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• 1994

본 연구는 아크롤레인의 선택산화반응에서 Mo-V-O와 금속산화물의 기계적 혼합촉매에 대한 synergy 효과를 고찰한 것으로 금속산화물로는 $SnO_2$, ${\alpha}-Sb_2O_4$, $WO_3$, ${\alpha}-Al_2O_3$, CuO, $MnO_2$, $Cu_2O$, MgO, CoO 그리고 ZnO 등을 사용하였다. $SnO_2$나 ${\alpha}-Sb_2O_4$와 Mo-V-O의 혼합물 촉매는 Mo-V-O보다 높은 전화율과 수율을 나타내었는데 이것은 이들이 산소 빈자리에 해리 홉착된 산소를 형성하여 Mo-V-O에 전달하는 상간협동에 의한 것으로 판단된다 그러나 $Cu_2O$, MgO, CuO, $MnO_2$와 Mo-V-O의 혼합물 촉매의 경우 전화율은 증가하였으나 수율은 감소하였고, CoO와 ZnO는 Mo-V-O의 촉매성능을 억제하였다. 각 금속산화물의 역할이 서로 다른 점을 그들의 산화-환원 특성으로 설명하였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.53-53
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• 2018

Thermoelectric materials can convert directly waste heat to electricity and vice versa. The improvement of the thermoelectric efficiency strongly depends on the dimensionless figure of merit, $ZT=S^2{\sigma}T/{\kappa}$, where S is the Seebeck coefficient, ${\sigma}$ is the electrical conductivity, T is the absolute temperature, and ${\kappa}$ is the thermal conductivity. The thermal conductivity consists of the electronic contribution (${\kappa}_e$) and phonon contribution (${\kappa}_{ph}$). It is very challenge to increase the power factor, $S^2{\sigma}$ and to reduce the thermal conductivity simultaneously because the power factor and electronic thermal conductivity are coupled. One strategy is to decrease the phonon thermal conductivity. The phonon thermal conductivity can be decreased by controlling the grain size and structural defects such as dislocations and twinning. In order to achieve enhancements in thermoelectric efficiency, microstructures that can form numerous interfaces have been investigated intensively for controlling the transport of charge carriers and heat carrying phonons. In this presentation, we report the heterogeneous microstructure of $Mg_2Si_{0.6}Sn_{0.4}$ thermoelectric materials and investigation of its influence on thermoelectric properties.

• 한국식품저장유통학회지
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• 제17권3호
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• pp.376-383
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• 2010

견과류 중 sunflower seed, cashew nut, walnut, pistachio, pumpkin seed, ginkgo, hazel nut, pecan을 원료로 하여 지방산 조성 분석 및 sn-2 position 분석, triacylglycerol species의 분석, tocopherol, phytosterol 함량을 분석하였다. 조지방 함량은 hazel nut에서 약 39.60 wt%로 가장 높았으며, walnut 35.25 wt%, pistachio 30.22 wt% 등의 순이었다. GC에 의한 sn-2 위치의 지방산 조성 분석 결과, oleic acid의 함량이 많은 견과류는 cashew nut, pistachio, hazel nut, pecan 이였으며, 특히 ginkgo의 경우 특이적으로 oleic acid의 이성체인 vaccenic acid가 10.72 wt% 나타냄을 확인할 수 있었다. 반면, linoleic acid 등이 높은 견과류는 sunflower seed, walnut, pumpkin seed 이었다. 견과류들의 TAG species의 PN값은 40∼52 사이에 존재하였다. Tocopherol의 함량은 ginkgo, sunflower seed, pumpkin seed 등에서 각각 48.57, 38.35, 31.43 mg/100 g 순으로 높은 함량을 나타내었다. 또한 총 phytosterol의 경우 88.60∼947.20 mg/100 g 사이에 함량을 나타내었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.37-37
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• 2015

합금 조성 및 열-기계적 처리 조건에 따라 제2상의 종류, 분율, 크기 등이 변화하였으며, 이러한 미세조직적 인자의 변화에 따라 부식거동이 변화하였다. 또한 부식환경에 따라 부식거동에 영향을 미치는 여러 인자들의 상호작용이 변화하였으며 이로 인하여 서로 다른 부식환경에서 합금 조성에 따른 부식거동의 차이가 발생하였다.

• Journal of Ginseng Research
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• 제39권2호
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• pp.148-154
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• 2015

Background: Ginseng is known to have antiapoptotic, anti-inflammatory, and antioxidant effects. The present study investigated a possible role of Korean Red Ginseng (KRG) in suppressing dopaminergic neuronal cell death and the cleavage of p35 to p25 in the substantia nigra (SN) and striatum (ST) using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. Methods: Ten-week-old male C57BL/6 mice were injected intraperitoneally with 30 mg/kg of MPTP at 24-h intervals for 5 d, and then administered KRG (1 mg/kg, 10 mg/kg, or 100 mg/kg) once a day for 12 consecutive days from the first injection. Pole tests were performed to assess the motor function of the mice, dopaminergic neuronal survival in the SN and ST was evaluated using tyrosine hydroxylase-immunohistochemistry, and the expressions of cyclin-dependent kinase 5 (Cdk5), p35, and p25 in the SN and ST were measured using Western blotting. Results: MPTP administration caused behavioral impairment, dopaminergic neuronal death, increased Cdk5 and p25 expression, and decreased p35 expression in the nigrostriatal system of mice, whereas KRG dose-dependently alleviated these MPTP-induced changes. Conclusion: These results indicate that KRG can inhibit MPTP-induced dopaminergic neuronal death and suppress the cleavage of p35 to p25 in the SN and the ST, suggesting a possible role for KRG in the treatment of Parkinson's disease.