• Title/Summary/Keyword: $SO_2$ reduction

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An Experimental Study on the Evaluation of Thermal Performance of Floor mortar with PCM (PCM을 혼입한 방통 모르타르의 열적 성능 평가에 관한 실험적 연구)

  • Kim, Bo-Hyun;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.5-6
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    • 2011
  • CO2 reduction is the most urgent issue the world is facing. So, there should be a measure to reduce the CO2 emission in construction industry which has more released CO2 gas than other industries. CO2 emission of building depend on using energy. Then efficient energy use process working efficiently at CO2 reduction. Therefore In this study, author find the technical possibility of saving the building energy using the PCM which is able to control heat, storage heat and potential heat. So, it considered that apply to floor heating type which is major heating system of living space in Korea. And evaluate the Using possibility.

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Preparation of Mono-Disperse Ni Powder for Multilayer Ceramic Capacitor by Solution-Reduction Method (용액환원법에 의한 MLCC용 단분산 니켈 미분말의 합성)

  • Kim, Kang-Min;Lee, Jong-Heun;Yoon, Seon-Mi;Lee, Yong-Kyun;Lee, Hyun-Chul;Choi, Jae-Young
    • Journal of the Korean Ceramic Society
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    • v.42 no.10 s.281
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    • pp.649-653
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    • 2005
  • A mono-disperse Ni powders for multilayer ceramic capacitors were prepared in a large scale by solution reduction method using $NiSO_{4}$ $N_{2}$$H_{4}$and NaOH. The exothermic reactions such as Ni-complex formation between highly concentrated $NiSO_{4}$ and $N_{2}$$H_{4}$ and the reduction of $Ni^{2+}$ into Ni provided thermal energy sufficient for spontaneous solution-reduction reaction. Because well-defined Ni particles could be prepared without external heating, the present method was named as 'auto-thermal method'. The formation of Ni­complex, the precipitation of $Ni(OH)_{2}$ gel triggered by NaOH addition, and its reduction into Ni by dissolution-recrystallization route were the reaction mechanism. The preparation of mono-disperse and spherical Ni powder was attributed to uniform distribution of reducing agent $N_{2}$$H_{2}$ within $Ni(OH)_{2}$ gel due to the decomposition of$NiSO_{4}$-$N_{2}$ $H_{4}$ complex.

Tolerance of Several Woody Plants to Sulphur Dioxide

  • Hwangbo, Jun-Kwon;Lee, Chang-Seok;Kim, Joon-Ho
    • Animal cells and systems
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    • v.4 no.4
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    • pp.337-340
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    • 2000
  • The photosynthetic and stomatal responses of several woody plants (Powlonia coreana, Firmiana simplex, Quercus acutissima Q. variabilis and Q. serrata) to SO$_2$ were investigated in order to understand their ecophysiological tolerance to $SO_2$ Of the plants, P, coreana showed the largest reduction in its photosynthesis in response to exposure of 0.4 ppm $SO_2$ for 20 h. Fumigation of 0.7 ppm $SO_2$ for 20 h caused complete leaf necrosis of P. coreana and f simplex, which made them unavailable for the measurement of photosynthesis. Q. variabilis exhibited the smallest reduction in photosynthesis following exposure of 0.7 ppm $SO_2$ for 20 h. Both stomatal- and non-stomatal inhibition of the plants by $SO_2$ were determined according to equations by lkeda et at. (1992). When exposed to 0.4 ppm $SO_2$ for 20 h, F. simplex and P. coreana showed the lowest stomatal and non-stomatal inhibition, respectively, while Q. variabilis and Q. serrata exhibited the lowest stomatal and non-stomatal inhibition, respectively, in response to 0.7 ppm $SO_2$ for 20 h. The data are discussed with regard to resistance mechanisms of other plants to $SO_2$ exposure and implications for restoration of declined Korean forests.

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Relationships between Methane Production and Sulfate Reduction in Reclaimed Rice Field Soils

  • Lee, Ju-Hwan;Cho, Kang-Hyun
    • Animal cells and systems
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    • v.8 no.4
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    • pp.281-288
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    • 2004
  • The change in relationships between methane production and sulfate reduction was investigated in reclaimed rice field soils at different time points after reclamation of tidal flat in Korea. Sulfate concentrations of soils in the ca. 60-year-old and 26-year-old reclaimed rice fields were much lower than that in a natural tidal flat. During 60 d of anaerobic incubation, total methane production and sulfate consumption of the soil slurries were 7.0 ${\mu}$mol $CH_4$/g and 8.2 ${\mu}$mol $SO_4^{2-}$/g in the 60-year-old rice field, 5.6 ${\mu}$mol $CH_4$/g and 12.7 mmol $SO_4^{2-}$/g in the 26-year-old rice field, and ca. 0 mmol $CH_4$/g and 22.4 ${\mu}$mol $SO_4^{2-}$/g in a natural tidal flat. Relative percent electron flow through sulfate reduction in the 60-year-old rice field was much lower (50.8%) compared with the 26-year-old rice field (69.3%) and the tidal flat (99.9%). The addition of an inhibitor of methanogenesis (2-bromoethanesulfonate) had no effect on sulfate reduction in the soil slurries of the reclaimed rice fields. However, instant stimulation of methane production was achieved with addition of an inhibitor of sulfate reduction (molybdate) in the soil slurries from the 26-year-old reclaimed rice field. The specific inhibitor experiments suggest that the relationship of methanogenesis and sulfate reduction might become mutually exclusive or syntrophic depending on sulfate content in the soil after reclamation. Sulfate, thus sulfate reduction activity of sulfate-reducing bacteria, would be an important environmental factor that inhibits methane production and determines the major pathway of electron and carbon flow in anaerobic carbon mineralization of reclaimed rice field soils.

Inorgainc fouling and it fouling reduction in direct contact membrane distillation process (직접 접촉식 막 증발공정에서 무기 막오염 특성 분석 및 저감방법)

  • Lee, Tae-Min;Kim, Seung-Hyun
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.2
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    • pp.115-125
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    • 2020
  • This study was aimed to examine inorganic fouling and fouling reduction method in direct contact membrane distillation(DCMD) process. Synthetic seawater of NaCl solution with CaCO3 and CaSO4 was used for this purpose. It was found in this study that both CaCO3 and CaSO4 precipitates formed at the membrane surface. More fouling was observed with CaSO4(anhydrite) and CaSO4·0.5H2O(bassanite) than CaSO4·2H2O(gypsum). CaCO3 and gypsum were detected at the membrane surface when concentrates of SWRO(seawater reverse osmosis) were treated by the DCMD process, while gypsum was found with MED(multi effect distillation) concentrates. Air backwash(inside to out) was found more effective in fouling reduction than air scouring.

The Adsorption of COS with a Modified-Activated Carbon for Ultra-Cleanup of Coal Gas (석탄가스의 초정밀 정제를 위한 변형된 활성탄의 흡착특성 연구)

  • Lee, You-Jin;Park, No-Kuk;Lee, Tae-Jin
    • Clean Technology
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    • v.13 no.4
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    • pp.266-273
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    • 2007
  • The adsorption properties of the activated carbon-based adsorbents were studied to remove COS emitted from $SO_2$ catalytic reduction process on the integrated gasification combined cycle (IGCC) system in this work. Transition metal supported catalysts and mixed metal oxide catalysts were used for the $SO_2$ catalytic reduction. The mechanism of COS produced from the $SO_2$ reduction and the COS concentration s according to the reaction temperature were investigated. In this study, an activated carbon and a modified activated carbon doped with KOH were used to remove the very low concentration of COS effectively. The adsorption rate and the breakthrough time of COS were measured by a thermo gravity analyzer (TGA, Cahn Balance) and a fixed bed flow reactor equipped with GC-pulsed flammable photometric detector (PFPD), respectively. It was confirmed that the COS breakthrough time of the activated carbon doped with KOH was longer than that of an activated carbon. In conclusion, the modified-activated carbon having a high surface area showed a high adsorption rate of COS produced from the $SO_2$ reduction.

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The Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur over Supported Cobalt Catalysts (담지 코발트 촉매를 이용한 SO2의 원소황으로의 환원반응 특성)

  • Park, Joon Hyo;Han, Jong Dae
    • Applied Chemistry for Engineering
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    • v.10 no.8
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    • pp.1129-1135
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    • 1999
  • The reduction of $SO_2$ by CO over supported cobalt catalysts was investigated within the temperature range of $350{\sim}550^{\circ}C$, initial $SO_2$ concentration of 1000~10000 ppm, $CO/SO_2$ molar ratio of 1.0~3.0 and space velocity of $5000{\sim}15000h^{-1}$. Several types of supports such as ${\gamma}-Al_2O_3$, $TiO_2$ were tested. The $SO_2$ conversion and selectivity to elemental sulfur were investigated using a differential fixed bed reactor at atmospheric pressure. The catalyst prepared by wet impregration of 5 wt % cobalt on ${\gamma}-Al_2O_3$ showed $SO_2$ conversion higher than 90% and COS yield lower than 6% at temperature above $400^{\circ}C$. The optimum $CO/SO_2$ molar ratio was investigated as 2.0. At higher $CO/SO_2$ molar ratio, the $SO_2$ conversion became higher but the main product was COS. The effect of $SO_2$ concentration and space velocity over $SO_2$ conversion and COS yield was not appreciable in the experimental range. The activated cobalt phase was detected as $CoS_2$ and the $CoS_2$ phase unchanged even after reaction.

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Antibacterial effect of natural dyed fabrics using Artemisia princeps extract against antibiotic-resistant strains (쑥 추출액을 이용한 천연염색 직물의 항생제 내성균주에 대한 항균효능)

  • Choi, Nayoung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.4
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    • pp.95-103
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    • 2021
  • This study aims to examine the antibacterial effects of cotton and silk fabrics naturally dyed with Artemisia princeps extract on antibiotic-resistant strains of bacteria. The concentrated natural dye of the Artemisia princeps extract was made at the liquor ratio of 1:10 at 40-60℃ for 60 minutes. The concentration of FeSO4·7H2O, Al2(SO4)3, and CuSO4 5H2O mordant was 3% (owf), and the liquor ratio was 1:20. In order to experiment on the antimicrobial activity of the naturally dyed fabrics, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, was used by breeding it in Brain Heart Infusion Agar (BHA) containing Oxacillin (2㎍/ml), Fungizone (2.5㎍/ml), and Brain Heart Infusion broth (BHI; Detroit, MI, USA). As a result of examining the bacterial growth reduction rate on dyed cotton and silk fabrics against antibiotic-resistant strains, it was found that the copper mordant in cotton fabric shows the highest antibacterial activity with a bacterial growth reduction rate of 99.9%, and the non-mordant cotton fabric shows the lowest antibacterial activity with a reduction rate of 18.6%. In the case of the naturally dyed silk fabric, it indicates the highest reduction rate of strains in the Al mordanting (94.9%), and Cu mordanting (99.9%).

An Experimental Study on the Comparison between Sasang Herbal Medicine for So-Eum and So-Yang Type Using Issatchenkia orientalis (KCTC 7277) (Issatchenkia orientalis (KCTC 7277)를 이용한 소음인과 소양인 약재의 비교 실험연구)

  • Park, Young Joo;Choi, Ji Eun;Kang, Young Min;Kim, Jong Yeol
    • KSBB Journal
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    • v.32 no.1
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    • pp.46-53
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    • 2017
  • There are four types (So-Eum, So-Yang, Tae-Eum, Tae-Yang type) in Sasang constitutional medicine (SCM). In SCM, not only people but also herbal medicine are classified into four types. To date, there has been very little evidence of experimental classifications in SCM. So, we adapted Issatchenkia orientalis in two different culture media made from the herbal medicines for So-Eum and for So-Yang type. And the adapted Issatchenkia orientalis was inoculated into another eight culture media made from the herbal medicines for So-Eum and for So-Yang type. The mass reduction was measured every 12 hours for 2 days. Then, we analyzed the statistical differences of herbal medicines for So-Eum and for So-Yang type. There were significant differences of variables (R: rate of change in mass reduction, S: convex degree of mass reduction graph) in herbal medicine media for So-Eum (p=0.001, 0.001, respectively.). Suggesting a microbiological method of Sasang medicine research, current study may contribute to the establishment of experimental Sasang constitutional herbal medicine.

Development and Evaluation on a Model for Reducing SO2: Case Study on Global 2100 Model (산성비 원인물질인 이산화황 저감모형 구축과 평가에 관한 연구: Global 2100 모형을 중심으로)

  • Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.6 no.2
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    • pp.93-102
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    • 1997
  • Acid rain below pH 5.6 is responsible for 40% of annual precipitation in Korea and it is more serious especially in major cites. Because of that, it is urgent to make measures to reduce the emission of $SO_2$, one of the major air pollutants causing acid rain. The national total emission of $SO_2$ in 1994 was estimated as 1.6 million tons. The $SO_2$ emission in 2020, is expected to increase up to 3.2 million tons, about 2 times that of 1994 under Business-As-Usual scenario. We could take various $SO_2$ reduction measures such as installing desulfurization facilities, the supply of low-sulfur oil and clean fuel(LNG), energy savings, upgrading of production process. However, it is necessary to check the economic feasibility and the attainability to reduction target with a dynamic optimization mode, "Global 2100 Model". The cost-benefit analyses for the measures using the revised "Global 2100 Model" clearly revealed that the desulfurization facilities should be introduced to reduce the $SO_2$ concentration to 0.01 ppm with fuel substitution. If the introduction of desulfurization facilities is delayed, We can not attain the goal of Ministry of Environment before the year of 2012, even in the case that almost all the fuels would be substituted with LNG.

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