• 제목/요약/키워드: $CO_2$ levels

검색결과 2,372건 처리시간 0.036초

글리신 금속염 함침 입자상 활성탄의 저농도 이산화탄소 흡착능 평가연구 (Adsorption of Low-level CO2using Activated Carbon Pellet with Glycine Metal Salt Impregnation)

  • 임윤희;;조영민
    • 한국대기환경학회지
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    • 제30권1호
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    • pp.68-76
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    • 2014
  • The present study has evaluated the $CO_2$ adsorption amount of activated carbon pellets (AC). Coconut shell based test AC were modified with surface impregnation of glycine, glycine metal salts and monoethanolamine for low level $CO_2$ (3000 ppm) adsorption. Physical and chemical properties of prepared adsorbents were analyzed and the adsorbed amount of $CO_2$ was investigated by using pure and 3,000 ppm $CO_2$ levels. The impregnation of nitrogen functionalities was verified by XPS analysis. The adsorption capacity for pure $CO_2$ gas was found to reach upto 3.08 mmol/g by AC-LiG (Activated carbon-Lithium glycinate), which has the largest specific surface area ($1026.9m^2/g$). As for low level $CO_2$ flow the primary amine impregnated adsorbent showed 0.26 mmol/g of adsorption amount, indicating the highest selectivity. An adsorbent with potassium-glycine salts (AC-KG, Activated carbon-Potassium glycinate) instead of amine presented with 0.12 mmol/g of adsorption capacity, which was higher than that of raw activated carbon granules (0.016 mmol/g).

CdS 및 CdS:Co2+ 단결정의 성장과 광학적 특성 (Growth and optical properties of undoped and Co-doped CdS single crystals)

  • 오금곤;김남오;김형곤;현승철;박현;오석균
    • 전기학회논문지P
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    • 제51권3호
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    • pp.137-141
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    • 2002
  • CdS and $CdS:Co^{2+}$ single crystals were grown by CTR method using iodine as transport material. The grown single crystals have defect chalcopyrite structure with direct band gap. The optical energy band gap was decreased according to add of Co-impurity. We can observed the Co-impurity optical absorption peaks assigned to the $Co^{2+}$ ion sited at the $T_d$ symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.

CdS 및 $CdS:Co^{2+}$ 단결정의 성장과 광학적 특성 (Growth and optical properties of undoped and Co-doped CdS single crystals)

  • 김남오;방태환;현승철;박광호;박현;오석균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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    • pp.94-97
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    • 2002
  • CdS and $CdS:Co^{2+}$ single crystals were grown by CTR method using iodine as transport material. The grown single crystals have defect chalcopyrite structure with direct band gap. The optical energy band gap was decreased according to add of Co-impurity. We can observed the Co-impurity optical absorption peaks assigned to the $Co^{2+}$ ion sited at the $T_d$ symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.

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자주초롱꽃의 기내 자가영양배양시 $CO_2$농도, 환기횟수 및 광도가 생장에 미치는 영향 (Effect of $CO_2$ Concentration, NAEH and Light Intensity on the Photoautotrophic Growth of Campanula punctata 'Rubriflora' Plantlets In Vitro)

  • 심재남;김경희;정병룡
    • 생물환경조절학회지
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    • 제14권4호
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    • pp.233-238
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    • 2005
  • 자주초롱꽃(Campanula punctata 'Rubriflora')의 자가영양배양시 $CO_2$ 농도,환기횟수 및 광도가 소식물체의 생장에 미치는 영향을 조사하였다. $1,500{\mu}mol{\cdot}m^{-1}$고농도$CO_2$에서는 광도를 높일수록 초장, 엽수가 증가되었으나, 최대근장은 유의성이 인정되지 않았다 엽록소의 함량은 광도가 높을 때보다는 낮은 경우인 $70{\mu}mol{\cdot}m^{-2}s^{-1}$에서 가장 많이 증가되었다 엽면적은 광도가 높을수록 작아지는 경향을 보였으며, $CO_2\;1,500{\mu}mol{\cdot}mol^{-1}$ 환기횟수 $2.8h^{-l},\;PPF\; 220{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$에서 가장 큰 차이로 작게 나타났다. 생체중과 건물중은 $CO_2$ 농도, 환기횟수, PPF가 높을수록 증가되었다. 특히 $CO_2\;1,500{\mu}mol{\cdot}mol^{-1}$, 환기횟수 $2.8h^{-1},\;PPF\; 220{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$에서 가장 크게 증가되었다. 환기횟수의 영향은 전반적으로 적었다. 종합적으로 자주초롱꽃 소식물체의 기내 자가영양배양 차량번식을 위해서는 $CO_2\;1,500{\mu}mol{\cdot}mol^{-1},\;PPF\;220{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$의 조건이 적합하였다.

산업단지 내 저층과 고층 아파트의 외기 중 호흡성분진과 일산화탄소 수준 (Ambient Levels of CO and PM10 at Low- and High-floor Apartments in Industrial Complexes)

  • 조완근;이준엽
    • 한국환경과학회지
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    • 제15권8호
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    • pp.719-725
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    • 2006
  • Since low-floor apartments ate vertically closer to patting lots and roadways, it is hypothesized that residents in low-floor apartments may be exposed to elevated ambient levels of motet vehicle emissions compared to residents in high-floor apartments. The present study examined this hypothesis by measuring two motor vehicle source-related pollutants(CO and PM10) in ambient air of high-rise apartment buildings within the boundary of industrial complexes according to atmospheric stability The ambient air concentrations of CO and PM10 were higher for low-floor apartments than for high-floor apartments, regardless of atmospheric stability, The median concentration ratio of the low-floor air to high-floor alt ranged from 1.3 to 2.0, depending upon atmospheric stabilities, seasons and compounds. Moreover, the CO and PM10 concentrations were significantly higher in the winter and in the summer, regardless of the Hoot height. Atmospheric stability also was suggested to be important for the residents' exposure of high-rise apartment buildings to both CO and PM10. The median ratios of surface inversion air to non-surface inversion air ranged from 1.2 to 1.7 and from 1.0 to 1.6 lot PM10 and CO, respectively, depending upon seasons. Conclusively, these parameters(apartment floor height, season, and atmospheric stability) should be considered when evaluating the exposure of residents, living in high-rise apartment buildings, to CO and PM10. Meanwhile, the median PMl0 outdoor concentrations were close to or higher than the Korean annual standards for PM10, and the maximum PM10 concentrations substantially exceeded the Korean PM10 standard, thus suggesting the need for a management strategy for ambient PM 10. Neither the median nor the maximum outdoor CO concentrations, however, were higher than the Korean CO standard.

Coenzyme Q10 첨가 급여가 산란계의 지방대사 연관 유전자 발현에 미치는 영향 (Effects of Coenzyme Q10 on the Expression of Genes involved in Lipid Metabolism in Laying Hens)

  • 장인석;문양수
    • 한국가금학회지
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    • 제43권1호
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    • pp.47-54
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    • 2016
  • Coenzyme Q10(CoQ10)은 자연계에 널리 분포하는 화합물로 세포호흡과 항산화제로서 그 기능이 잘 알려졌지만, 최근 유전자들의 발현 조절자로서의 가능성도 제시되었다. 따라서 본 연구는 산란계에서 CoQ10의 첨가 급이가 콜레스테롤과 지방산 대사관련 유전자들의 발현에 미치는 영향을 관찰하고자 실시하였다. Lohmann Brown(40주령) 36수를 CoQ10의 첨가원에 따라 대조군(CON, basal diet(BD)), CoQ10 건조분말 급여군(T1, BD+CoQ10 100 mg/kg 사료) 및 CoQ10 건조분말 유화처리군(T2, BD+micellar of CoQ10 100 mg/kg 사료) 등 모두 3처리구로 설정하여 5주간 사양시험을 실시하였다. 시험 종료 후 각 개체의 간으로부터 total RNA를 추출하고, real-time PCR을 이용하여 유전자들의 발현을 분석하였다. 콜레스테롤 합성 과정에서 주요 조절 효소인 HMGCoA reductase(HMGCR)의 유전자 발현은 대조구에 비하여 CoQ10 분말첨가인 T1과 유화처리된 T2 처리구에서 모두 약 50%씩 억제되었다(p<0.05). 내생 콜레스테롤의 합성을 촉진시키는 전사인자인 SREBP2 mRNA 발현 또한 대조구와 비교해서 T1과 T2에서 각각 30%와 40% 감소하였다(p<0.05). CoQ10의 첨가 급이는 대조구에 비하여 liver X receptor(LXR) 유전자가 약 30~35% 그 발현이 억제되었으며, sterol regulatory element-binding proteins(SREBPs)1 또한 T2에서 약 40% 유전자 발현이 감소하였다(P<0.05). 전사인자인 $PPAR{\gamma}$와 XBP1은 CoQ10에 의하여 약 15~40% 수준으로 효과적으로 억제됨을 확인하였다(p<0.05). 세포 내부로의 에너지 공급원인 포도당의 흡수를 담당하는 GLUT2는 약 35~60% 그리고 GLUT8은 약 25~30%의 유전자발현 각각 감소함을 보였다(p<0.05). CoQ10의 섭취는 중성지방 합성을 위한 지방합성효소(FASN)의 유전자 발현을 분말처리군에서 약 30%, 유화처리군에서 약 65% 억제됨을 확인하였다(P<0.05). 본 연구결과는 CoQ10 첨가급여가 콜레스테롤 및 지방대사 관련 유전자 발현에 영향을 미치며, 세포내 콜레스테롤과 지방의 생성도 억제할 수 있음을 보여주었다.

대기오염도의 공간적 분포 변화 분석 -수도권 지역을 대상으로- (Spatial Distributions of the Ambient Levels of Air Pollutants in Seoul Metropolitan Area)

  • 권오상;안동환;김원희
    • 자원ㆍ환경경제연구
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    • 제13권1호
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    • pp.83-117
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    • 2004
  • 본 연구는 수도권지역 대기오염 측정망의 오염물질별 연평균 오염도 측정치를 이용하여 최근 10년간의 수도권내 대기오염도의 공간적 분포 및 그 변화를 분석하였다. 분석을 위해 커널확률밀도함수를 추정하고, 또한 지니계수와 엔트로피계열의 불평등지수를 계측하였으며, 분석기간중 오염도의 공간적 분포 변화에 대한 통계적 검정을 실시하였다. 분석결과 최근 10년간 수도권 지역의 $SO_2$, $NO_2$, $O_3$와 CO 등 대기오염물질 오염도의 지역격차는 대체로 일정한 수준을 유지하거나 아니면 완화되는 것으로 나타났다. 또한 순위상관 분석 결과 분석기간 중 오염물질의 공간적 분포에 상당한 정도의 동태적 변화가 있었던 것으로 나타났다.

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Effect of Coenzyme Q10 Supplementation in Statin-Treated Obese Rats

  • Choi, Hye-Kyung;Won, Eun-Kyung;Choung, Se-Young
    • Biomolecules & Therapeutics
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    • 제24권2호
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    • pp.171-177
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    • 2016
  • Statins, HMG-CoA reductase inhibitors, are known to cause serious muscle injuries (e.g. myopathy, myositis and rhabdomyolysis), and these adverse effects can be rescued by co-administration of coenzyme $Q_{10}$ ($CoQ_{10}$) with statins. The goal of the current research is to assess the efficacy of combined treatment of $CoQ_{10}$ with Atorvastatin for hyperlipidemia induced by high-fat diet in SD rats. 4-week-old Sprague-Dawley male rats were fed normal diet or high-fat diet for 6 weeks. Then, rats were treated with either Statin or Statin with various dosages of $CoQ_{10}$ (30, 90 or 270 mg/kg/day, p.o.) for another 6 weeks. Compared to Statin only treatment, $CoQ_{10}$ supplementation significantly reduced creatine kinase and aspartate aminotransferase levels in serum which are markers for myopathy. Moreover, $CoQ_{10}$ supplementation with Statin further reduced total fat, triglycerides, total cholesterol, and low-density lipoprotein-cholesterol. In contrast, the levels of high-density lipoprotein-cholesterol and $CoQ_{10}$ were increased in the $CoQ_{10}$ co-treated group. These results indicate that $CoQ_{10}$ treatment not only reduces the side effects of Statin, but also has an anti-obesity effect. Therefore an intake of supplementary $CoQ_{10}$ is helpful for solving problem of obese metabolism, so the multiple prescription of $CoQ_{10}$ makes us think a possibility that can be solved in being contiguous to the obesity problem, a sort of disease of the obese metabolism.

G009가 Peroxidizers에 의해 유발된 지질 과산화에 미치는 영향 (Effect of G009 on Lipid Peroxidation Induced by Peroxidizer in Rats)

  • 이준우;정훈;이승목;김기남;한만덕;이승룡;김수웅;강상모
    • Biomolecules & Therapeutics
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    • 제4권3호
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    • pp.244-250
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    • 1996
  • In this study, the anti-lipidperoxidative effects of G009, a polysaccharide extracted from Ganoderma lucidum IY009, was determined in ascorbic acid-$Fe^{2+}$-adenosine 5-diphosphate-intoxicated rat. In a model of ascorbic acid-Fe$^{2+}$-adenosine 5-diphosphate-induced hepatotoxicity in rat, G009 exhibited anti-lipidperoxidative effect in rat liver homogenate, and that malondialdehyde values of the liver homogenate inhibited from 48.1% to 74.8% in comparison to controls (p<0.05). The malondialdehyde formation in serum inhibited 66.5% at 100 mg/kg of G009. Also, serum levels of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase in peroxidizer-induced rats treated with G009 was decreased compared with control. Especially, the formation of lipid peroxides in serum was related to glutamic pyruvic transaminase levels. These results suggest that G009 has a protective effect on ascorbic acid-$Fe^{2+}$-adenosine 5-diphosphate-induced hepatic injury through an inhibition of lipid peroxidation in liver.r.

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Comparison of Model-simulated Atmospheric Carbon Dioxide with GOSAT Retrievals

  • Shim, Chang-Sub;Nassar, Ray;Kim, Jhoon
    • Asian Journal of Atmospheric Environment
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    • 제5권4호
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    • pp.263-277
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    • 2011
  • Global atmospheric $CO_2$ distributions were simulated with a chemical transport model (GEOS-Chem) and compared with space-borne observations of $CO_2$ column density by GOSAT from April 2009 to January 2010. The GEOS-Chem model simulated 3-D global atmospheric $CO_2$ at $2^{\circ}{\times}2.5^{\circ}$ horizontal resolution using global $CO_2$ surface sources/sinks as well as 3-D emissions from aviation and the atmospheric oxidation of other carbon species. The seasonal cycle and spatial distribution of GEOS-Chem $CO_2$ columns were generally comparable with GOSAT columns over each continent with a systematic positive bias of ~1.0%. Data from the World Data Center for Greenhouse Gases (WDCGG) from twelve ground stations spanning $90^{\circ}S-82^{\circ}N$ were also compared with the modeled data for the period of 2004-2009 inclusive. The ground-based data show high correlations with the GEOS-Chem simulation ($0.66{\leq}R^2{\leq}0.99$) but the model data have a negative bias of ~1.0%, which is primarily due to the model initial conditions. Together these two comparisons can be used to infer that GOSAT $CO_2$ retrievals underestimate $CO_2$ column concentration by ~2.0%, as demonstrated in recent validation work using other methods. We further estimated individual source/sink contributions to the global atmospheric $CO_2$ budget and trends through 7 tagged $CO_2$ tracers (fossil fuels, ocean exchanges, biomass burning, biofuel burning, net terrestrial exchange, shipping, aviation, and CO oxidation) over 2004-2009. The global $CO_2$ trend over this period (2.1 ppmv/year) has been mainly driven by fossil fuel combustion and cement production (3.2 ppmv/year), reinforcing the fact that rigorous $CO_2$ reductions from human activities are necessary in order to stabilize atmospheric $CO_2$ levels.