• 제목/요약/키워드: Oxygen Deficiency

검색결과 151건 처리시간 0.023초

Saccharomyces cerevisiae에서 myo-Inositol 결핍에 의한 Respiratory capacity의 감소

  • 정경환;이준식
    • 한국미생물·생명공학회지
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    • 제24권4호
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    • pp.485-492
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    • 1996
  • myo-Inositol, a growth factor for Saccharomyces cerevisiae (S. cerevisiae), has been known to be incorporated into phosphatidylinositol (PI), which is a kind of phospholipid in the cell membrane, by a membrane-associated PI-synthesizing enzyme. The deficiency of myo-inositol in S. cerevisiae adversely affected the membrane structure and function. On the basis of biochemical functions of myo-inositol, the effect of deficiency of myo-inositol on the aerobic glucose metabolism was investigated by measuring specific oxygen uptake rate (Q$_{O2}$) used as an indicator representing the respiratory capacity of S. cerevisiae in batch and continuous cultures. The respiratory capacity of aerobic glucose metabolism in S. cerevisiae was also monitored after glucose pulse-addition in a continuous culture (D=0.2, 1/hr), in which glucose was utilized through respiratory metabolism. The deficiency of myo-inositol was found to lead to both the decrease of the maximum specific oxygen uptake rate (Q$_{O2max}$) observed from the batch as well as in the continuous culture experiment and the decrease of the respiratory capacity of aerobic glucose metabolism of S. cerevisiae determined from the glucose pulse-addition experiment, in which the glucose flux into respiratory and fermen- tative metabolism was quantitatively analyzed.

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밀폐공간 질식재해 통계현황 분석 (A Study on Statistics for Accidents in Confined Space in Korea)

  • 유계묵;박현희;정광재
    • 한국산업보건학회지
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    • 제19권4호
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    • pp.363-369
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    • 2009
  • The total number of confined space accident cases from 1999 to 2007 in Korea were 220, causing 353 injuries and 212 casualties. Out of 220 cases, 44(20.0%) occurred in sewage treatment facilities and 40(18.2%) occurred in both manholes and containers. When the main causes of confined space accidents were classified, oxygen deficiency accounted for 69 cases(31.4%), carbon monoxide, 48(21.8%), hydrogen sulfide, 40(18.2%), and organic solvent, 32(14.5%). Improvement of occupational accident statistics is necessary in order to report accurate and precise data for confined space accidents. The structure of confined space must be considered when selecting gas to be measured.

터보냉동기의 HCFC-123 누출에 대한 수치해석 연구 (Numerical Study on the HCFC-123 Leak in Turbo Chiller by using CFD)

  • 서회경;송세욱;황양인;하현철
    • 한국가스학회지
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    • 제18권5호
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    • pp.85-90
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    • 2014
  • 대용량의 공기조화용으로 널리 사용되는 터보냉동기는 냉매로 HCFC-123 가스를 주로 사용하며, HCFC-123은 CFC계 프레온의 대체 냉매제로 독성은 낮으나 환기가 원활하지 않는 밀폐공간이나 작업공간에서 산소결핍으로 인한 질식재해를 유발할 수 있는 것으로 보고되고 있다. 본 연구에서는 2011년 대형할인마트 기계실 내부 터보냉동기 냉매 누출로 인해 작업자 4명이 질식 등의 사유로 사망한 재해 사례를 대상으로 전산유체역학을 이용하여 HCFC-123 누출에 따른 산소농도를 예측함으로써 프레온 가스 누출사고에 대한 원인을 조사하고 대응책을 제시하여 동종 재해의 재발 방지에 도움이 되고자 한다.

산소 결함이 ZnGa_2O_4$:Mn형광체 발광 특성에 미치는 효과 (Effect of oxygen defects on luminescent characteristics of ZnGa_2O_4$:Mn phosphors)

  • 박용규;한정인;곽민기;한종근;주성후
    • E2M - 전기 전자와 첨단 소재
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    • 제9권10호
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    • pp.1040-1046
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    • 1996
  • Low voltage phosphor, ZnGa$_{2}$O$_{4}$:Mn, was synthesized and sintered at the high temperature in Ar or vacuum. By XRD analysis, it is confirmed that poly crystalline ZnGa$_{2}$O$_{4}$:Mn solid solution was formed. From EPMA analysis of the samples prepared in Ar and vacuum, the change of oxygen content was investigated and as a result, it was observed that the oxygen amounts were reduced in ZnGa$_{2}$O$_{4}$:Mn prepared in vacuum. It caused the deficiency in oxygen amounts in the phosphor and then consequently, it results in the formation of the energy level near 513 nm. It contributes to the improvement of the brightness of ZnGa$_{2}$O$_{4}$:Mn.

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The Solar Nebular on Fire: A Solution to the Carbon Deficit in the Inner Solar System

  • 이정은
    • 천문학회보
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    • 제35권1호
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    • pp.91.1-91.1
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    • 2010
  • Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon grains in the Solar Nebula. We present a solution wherein primordial carbon grains are preferentially destroyed by oxygen atoms ignited by heating due to stellar accretion at radii < 5 AU. This solution can account for the bulk carbon deficiency in the Earth and meteorites, the compositional gradient within the asteroid belt, and for growing evidence for similar carbon deficiency in rocks surrounding other stars.

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간질성 폐질환의 연구 동향 (Research Trends of Interstitial Lung Disease)

  • 손지우;이정욱;이병순;노운섭;이병주;신조영;이시형
    • 대한한의정보학회지
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    • 제13권1호
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    • pp.26-38
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    • 2007
  • Interstitial lung disease (ILD) is characterized by progressive scarring of the lung leading to restriction and diminished oxygen transfer. Clinically, the presenting symptoms of ILD are nonspecific (cough and progressive dyspnea on exertion) and are often attributed to other diseases, thus delaying diagnosis and timely therapy. In this study, I analyzed the 10 chinese papers of interstitial lung diseases(ILD). The etiology are body resistance weakness(本虛) and pathogenic factor prevailing(標實). The body resistance weakness(本虛) including deficiency of the lung(肺虛), deficiency of the kidney(腎虛), deficiency of the spleen(脾虛), deficiency of Qi and Yin(氣陰兩虛), pathogenic factor prevailing(標實) including stagnation of phlegm(痰濁), blood stasis(瘀血), noxious heat(熱毒). As an treatment aim at supplementing lung and kidney(益肺腎), resolving phlegm and blood stasis(化痰瘀).

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넙치 육상수조 양식에 있어 편조류 Cochlodinium polykrikoides의 구제를 위한 화학적 처리 (Experimental Chemical Treatments for the Control of Dinoflagellate Cochlodinium polykrikoides in the Land-based Culture of Olive Flounder Paralichthys olivaceus)

  • 류호영;심정민;방종득;이주
    • 한국양식학회지
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    • 제11권3호
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    • pp.285-294
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    • 1998
  • When Cochlodinium polykrikoides came into the culture tanks through influent cultivated water during the red tides, hundred thousands of commercial flounders were concomitantly killed and many culturists suffered from a great deal of financial loss in the east coast of Korea. It is charactrized by high sinking rate after sunset and the formatino of clump which results in oxygen deficiency by its respiration at tank bottom under condition. We investigated the efficacy of hydrogen peroxide and chlorine dioxide, known to form radicals, for extermination of red tide organism C. polykrikoides. When C. polykrikoides seawater with a density of 6,000 cells/$m\ell$ was treated with 14, 28 and $42mg/\ell$ of hydrogen peroxide, its survival rate was markedly decreased to 9.8, 0.8 and 0.3% respectively immediately after 6 hours of treatments whereas when it was treated with 1.5, 2.1 and $3.0mg/\ell$ chlorine dioxide, its survival rate showed 87.7, 81.3 and 80.1 and 80.1% respectively at the same treatment time. Hydrogen peroxide was the effective agent since it has scarcely injured the cultured olive flounder when exposed to the tested concentration range of $14~28mg/\ell$ with the extermination of almost3 C. polykrikoides during the experimental period of 5 days and has shown the oxygen increase of approximately $1.23mg/\ell$ 2 hours immediately after the flounder by C. polykrikoides in the land-based culture tank is assumed to be not by the toxicity of itself but by oxygen dificiency from the rapid respiration of dinoflagellate clump sunken to the tank bottom.

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SAW 필터용 ZnO 압전 박막의 전기적 특성 (Electrical Characteristics of ZnO Piezo-electric Thin film for SAW filter)

  • 이동윤;윤석진
    • 한국전기전자재료학회논문지
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    • 제18권10호
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    • pp.909-916
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    • 2005
  • The structural and electrical property of RF magnetron sputtered ZnO thin film have been studied as a function of RF power, substrate temperature, oxygen/argon gas ratio and film thickness at constant sputtering power, sputtering working pressure and target-substrate distance. To analyze a crystallo-graphic properties of the films, $\theta$/2$\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity and surface roughness highly depended on oxygen/argon gas ratio. The resistivity of ZnO thin film(6000 ${\AA}$) rapidly increased with increasing oxygen ratio and the resistivity value of $9 {\ast} 10^7 {\Omega}cm$ was obtained at a working pressure of 10 mTorr with the same oxygen/argon gas ratio. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with the same oxygen/argon gas ratio showed the excellent roughness value of 28.7 ${\AA}$. With increase of the substrate temperature, The C-axis preferred orientation of ZnO thin film increases and the resistivity decreases due to deviation from the stoichiometric ZnO due to oxygen deficiency.