• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1265-1272
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• 2007

A solid acid catalyst, NiSO4/CeO2-ZrO2 was prepared simply by promoting ZrO2 with CeO2 and supporting nickel sulfate on CeO2-ZrO2. The support of NiSO4 on ZrO2 shifted the phase transition of ZrO2 from amorphous to tetragonal to higher temperatures because of the interaction between NiSO4 and ZrO2. The surface area of 10-NiSO4/1-CeO2-ZrO2 promoted with CeO2 and calcined at 600 oC was very high (83 m2/g) compared to that of unpromoted 10-NiSO4/ZrO2 (45 m2/g). This high surface area of 10-NiSO4/1-CeO2-ZrO2 was due to the promoting effect of CeO2 which makes zirconia a stable tetragonal phase as confirmed by XRD. The role of CeO2 was to form a thermally stable solid solution with zirconia and consequently to give high surface area and acidity of the sample, and high thermal stability of the surface sulfate species. 10-NiSO4/1- CeO2-ZrO2 containing 1 mol% CeO2 and 10 wt% NiSO4, and calcined at 600 oC exhibited maximum catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation.

• 보존과학회지
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• 제25권2호
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• pp.147-154
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• 2009

경주지역 석조문화재의 주요 부재로 사용된 화강암과 응회암을 대상으로 수용성 염에 의한 풍화초기 암석의 강도와 수증기확산저항도 변화를 연구하였다. 수용성 염으로는 석조문화재에서 자주 검출되며, 용해도가 다른 $Na_2SO_4$와 $CaSO_4{\cdot}2H_2O$를 사용하였다. 휨강도는 응회암시편에서는 염종류와 무관하게 증가했으며, 화강암에서는 감소하였다. 일축압축강도는 응회암을 $CaSO_4{\cdot}2H_2O$로 처리 했을 때 증가하였고, $Na_2SO_4$로 처리 했을 때 감소하였으며, 화강암은 $CaSO_4{\cdot}2H_2O$ 처리 시 약간의 감소가, $Na_2SO_4^{\circ}C$ 처리 때에는 증가경향이 나타났다. 수증기확산저항도는 응회암에서 염종류와 상관없이 증가했고, 화강암은 $CaSO_4{\cdot}2H_2O$로 처리했을 때 증가했다. 연구결과, 염의 집적에 의한 풍화의 초기단계에서는 기계적 강도와 수증기확산저항도가 증가될 수 있음이 확인되었다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 추계학술발표회 초록집
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• pp.38-41
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• 1995

화석연료의 연소에 의하여 방출되는 SO$_2$ 와 NO 에 의한 대기오염의 심각성은 이미 잘 알려져 있으며 그에 따른 배출규제 또한 강화되고 있다. 최근에는 탈황과 탈질을 동시에 처리하는 동시 탈황탈질 공정의 연구가 진행되고 있다. 동시제거 공정은 주로 흡수제/촉매를 토대로 개발되고 있으며 산화구리가 담지된 알루미나 (CuO/${\gamma}$-A1$_2$O$_3$) 흡수제/촉매는 SOx, NOx 동시제거에 효과적인 물질로 알려져 있다. 담지된 CuO 와 담체 A1$_2$O$_3$는 SO$_2$ 와 $O_2$ 존재하에 반응하여 CuSO$_4$ 와 $Al_2$(SO$_4$)$_3$ 가되며 [1] CuSO$_4$ 와 미반응된 CuO 는 NO 제거를 위한 촉매로서의 역할을 하게 된다 [2].

• 시멘트
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• 통권51호
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• pp.20-30
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• 1973

1) electron-microprobe를 응용하여 $CaO-SiO_2-Al_2O_3$ 계에서 생성한 $C_2S$, $C_3S$ 에 존재하는 sulfate의 solid, solution을 정량적으로 구할 수 있었으며 이 결과로 $C_2S$ 에 $Al_2O_3$, $SO_3$ 등이 solid soln 등으로 침적되고 이들이 $C_3S$의 생성을 억제한다는 mechanism이 확인되었다. 2) phase equilibrium(상평형)에 의하면 $Na_2SO_4$, $K_2SO_4$는 mineralizer로서 작용하며 $C_3S$ 의 생성을 돕는다. 그러나 $K_2SO_4$ 와 $Al_2SO_3$ 가 결합상태로 존재할 경우는 1,400 $^{\circ}C$에서 광범위한 liquid를 생성하며 quenching하면 glass질과 $\beta-C_2S$ 만이 얻어지고 $C_3S$ 는 생성되지 않는다. 또 이를 1,250 $^{\circ}C$ 까지 서냉하면 $C_2S$ 와 Ca, K, Al, S, 등을 함유한 새로운 물질이 생성된다. 3) $CaO-SiO_2-Al_2O_3-Fe_2O_3$ 계에서 $C_3S$ 의 생성에 미치는 $Na_2SO_4$, $K_2SO_4$ 의 영향을 실험실적으로 검토한 결과 complex interaction이 확인되었으며 $Na_2SO_4$ 는 어떤 경우에는 mineralizing effect를 상실한다는 재미 있는 사실이 발견되었다.

• 환경위생공학
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• 제14권1호
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• pp.17-23
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• 1999

This study was performed to survey the $SO_2$ level at several underground spaces connected to 5 subway stations (City Hall, Nam, Seoul stations, Hye Hwa and Ulchiro 1 Ga) in Seoul. The period of survey was from July to November, 1997.The results of the study were as follows; 1. The mean concentration of $SO_2$ was $0.057{\pm}0.015ppm$ in all subway stations. The highest $SO_2$ level among the five stations was $0.067{\pm}0.011 ppm$ at City Hall (P<0.01), and the highest with $0.071{\pm}0.013ppm$ at November (P<0.01).2. In underground shopping centers, the mean concentration of $SO_2$ was $0.112{\pm}0.059ppm$. 3. The mean concentration of $SO_2$ at evening with 0.057 pp and morning with 0.053 ppm were significantly higher than at noon with 0.043 ppm(P<0.05). 4. The $SO_2$ level of floor at Kang Nam station with 0.044 ppm was significantly higher than that of platform with 0.37 ppm(P<0.01). 5. For the City Hall stations, the line #1 and line #2 subway spaces show significantly different level of $SO_2$, 0.042ppm and 0.033 ppm respectively (P<0.05).

• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.830-835
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• 1997

In this study an experimental investigation has been conducted to remove NOx and SO$_2$simultaneously from a combustion flue gases were consisted of NO-SO$_2$-$CO_2$-$N_2$-O$_2$([NO]o:200ppm and [SO$_2$]o:800ppm) and the injection gases used as radical source gases were NH$_3$-Ar-air and CH$_4$-Ar-air. NOx and SO$_2$removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as SO$_2$, NOx and NO$_2$gas detectors. and SEM images after sampling. The results showed that a significant Nucleating Particle Counter(CNPC) and SEM images after sampling. The results showed that a significant aerosol particle formation was observed during a simultaneous NOx and SO$_2$removal operation in corona radical shower systems. The diameter of aerosol particles was in the range of 0.18 to 3.6${\mu}{\textrm}{m}$ with a maximum fraction of particles at particles diameter of 1${\mu}{\textrm}{m}$. The NOx removal efficiency significantly increased with increasing applied voltage and NH$_3$molecule ratio. The SO$_2$removal efficiency was not significantly effected by applied voltage and slightly increased with increasing NH$_3$molecule ratio. It could be found that it is possible to use CH$_4$for NOx and SO$_2$removal by corona radical shower systems.

• Korean Chemical Engineering Research
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• 제45권1호
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• pp.81-86
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• 2007

산업 시설에서 발생하는 $SO_2$를 제거하기 위해 중공사막 기-액 접촉기를 사용하고 있다. 본 연구에서는 기-액 접촉기 내의 중공사막에서의 $SO_2$ 흡수거동 대하여 수학적으로 모델링하고, 그 모델을 유한 요소 분석법을 이용하여 모사하였다. $SO_2$의 분리에 영향을 주는 변수인 기체 유량, 분리막의 물질 전달 계수 및 접촉기의 물리적 특성에 따른 $SO_2$의 분리 효율 및 물질 전달 특성을 알아보았다. 기체의 유속 변화에 따른 중공사막을 통한 $SO_2$ 제거 효율 실험값으로부터 분리막의 물질 전달 계수를 추정하였다. 또한 중공사막 설계에 도움이 되는 자료를 계산할 수 있는 방법을 제시하였다.

• 공업화학
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• 제22권1호
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• pp.67-71
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• 2011

$Li/SO_2Cl_2$ 전지의 양극활물질은 $SO_2Cl_2$인데 이 물질은 전해액의 용매이기도 하다. 이를 일컬어 catholyte (cathode와 electrolyte의 합성어)라 칭하는데 전지의 방전이 진행됨에 따라 소진된다. 따라서 전지 제작 시 투입되는 $SO_2Cl_2$의 특성은 전지의 용량을 결정하는 중요 변수이다. 또한, $Li/SO_2Cl_2$ 전지의 transition minimum voltage (TMV)와 전압지연 편차는 전해액과 리튬의 반응에 의하여 형성된 부동화 막과 관련되는데 이 부동화 막은 전해액 내 불순물(수분 또는 중금속 이온)이 있을 경우 이의 성장이 촉진된다. 따라서 전해액을 정제시키는 기술과 이를 평가하는 방법의 정립은 반드시 필요하다. 본 연구에서는 $LiAlCl_4/SO_2Cl_2$전해액을 $AlCl_3$와 LiCl을 이용하여 제조하였고 제조된 전해액을 이온전도도계와 색도계 및 FT-IR을 이용하여 농도와 수분, 금속함량 등을 평가하였다.

• 한국환경과학회지
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• 제16권2호
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• pp.187-195
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• 2007

Long-term passive diffusive samplers(PDS) have been used to measure $NO_2\;and\;SO_2$ concentrations at 21 sampling sites in Daejeon, Korea during the period of January 2000 - December 2002. The spatial distributions of annual $NO_2\;and\;SO_2$ concentrations were mapped. Average annual $NO_2$ concentration over the sampling period was $28.5{\pm}12.5\;ppb$, ranging from 1.2 to 81.7 ppb. Average annual $SO_2$ concentration over the sampling period was $7.7{\pm}4.8\;ppb$, ranging from 0.6 to 26.8 ppb. On average, $NO_2$ concentration was approximately 5.8%(1.6 ppb) larger in 2002. $SO_2$ concentration was decreased by 13%(1.1 ppb) during the sampling period. The seasonal variation of $NO_2\;and\;SO_2$ concentration was observed with a tendency to be higher in fall and winter. $NO_2\;and\;SO_2$, concentrations measured at different site types(patterns of land use) show significant difference. The observed difference in concentration was associated with difference in emissions of $NO_2$ from motor vehicles and $SO_2$ by non-traffic fuel consumption for heating.

• Journal of Plant Biology
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• 제25권3호
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• pp.135-151
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• 1982

This investigation was carried out to clarify the changes of pigments and soluble protein, and photosystem II activity in the leaves of barley (${SO}_2$-sensitive) and corn (${SO}_2$-resistant) seedlings induced by the ${SO}_2$ fumigation (10, 50ppm). The pH changes of the leaf extract, the content of sulfite and sulfate, the activities of catalase, peroxidase, and polyphenoloxidase were compared in the leaves of barley and corn seedlings induced by ${SO}_2$ fumigation. The results are summarized as follows: An appreciable effect of pH change of leaf extract by ${SO}_2$ fumigation was observed in barley leaves (pH 6.10 to 5.18), but only a small change occurred in corn leaves (pH 5.66 to 5.50). The same pattern of pH changes was recorded when the solution of 0.2N HCl was added to leaf extract, providing lower buffering capacity of the barley leaves than corn leaves. After 2 hours of exposure to 10 ppm ${SO}_2$, the contents of ${SO}^{2-}_3$ and ${SO}^{2-}_4$ were increased in barley leaves, while only ${SO}^{2-}_4$ increased in corn leaves. After fumigation with 10ppm ${SO}_2$ for 2 hours, barley leaves showed significant decreases in activities of catalase, to 17% peroxidase, to 58%, and polyphenoloxidase, to 88%. Corn leaves showed increases in activities of peroxidase, to 136%, and polyphenoloxidase, to 128%. Absorption spectra of pigments obtained from ${SO}_2$-fumigated leaves were gradually decreased with the fumigation time increases, but the decrease was more significant in barley leaves. Fumigation with 50ppm ${SO}_2$ for 2 hours induced the greatest decomposition in carotenoid, followed by chlorophyll a and then chlorophyll b in barley leaves. The ratio of chlorophyll a/b was decreased from 4.1 to 3.6 in barley leaves, but in corn leaves it was maintained almost a constant level(4.9-4.8). The rate of decomposition of chlorophyll and carotenoid in corn leaves was very slow than those in the barley leaves. Fumigation with 50 ppm ${SO}_2$ for 2 hous, decreased the protein content of barley leaves to 59%, and that of corn leaves to 89%, and the extent of decrease in protein content was greater than that of pigments in barley and corn leaves. The rate of DCIP9dichlorophenol indophenol) photoreduction in ${SO}_2$-fumigated leaves was decreased to 18 and 67% in barley and corn leaves, respectively. However, DCIP photoreduction was considerably recovered about 32 and 92% with the addition of DPC(diphenylcarbazide) as an exogenous electron donor in barley and corn leaves, respectively.