• 제목/요약/키워드: concentration condition

검색결과 5,004건 처리시간 0.034초

Serratia marcescens에서 글리옥실산이 Prodigiosin 생합성에 미치는 연구 (Studies on the Effect of Glyoxylate on the Biosynthesis of Prodigiosin in Serratia marcescens)

  • 최병범;방선권
    • 한국식품영양학회지
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    • 제10권4호
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    • pp.475-479
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    • 1997
  • 최소 배지에 여러 아미노산과 대사 산물을 첨가하여 혐기성 조건하에서 배양시킨 Serratia marcescens ATCC 25419 세포 추출무에서 prodigiosin의 생합성을 조사한 결과 아미노산과 대사 산물들은 prodigiosin 생합성을 대조군보다 50-80% 정도 감소시켰다. 글리옥실산은 1-3mM에서 prodigiosin의 생합성을 대조군보다 20-40% 정도 증가시켰고, 특히 5mM의 농도에서는 최대 122% 증가시켰으나, 20-30mM에서 prodigiosin의 생합성을 50-90% 정도 감소시켰다. 한편, 혐기성과 호기성 조건의 피루브산과 $\alpha$-케토부티르산은 호기성 조건의 글리옥실산과 함께 조사한 모든 농도(0.5-30mM)에서 prodigiosin이 생성되지 않았으며 또한, 혐기성 조건하에서 높은 농도(20mM 이상)의 글리옥실산은 S. marcescens의 성장을 현저하게 억제시켰다. 이러한 결과들로부터 글리옥실산은 피루브산과 $\alpha$-케토부티르산과는 다르게 낮은 농도(1-5mM)에서는 S. marcescens의 1, 2차 대사물질로 작용하여 prodigiosin 생합성을 증가시키지만, 높은 온도(20mM 이상)에서는 S. marcescens의 성장을 억제시켜 2차 대사물질인 prodigiosin의 생합성도 억제된다고 사료된다.

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컴퓨터 그랙픽을 이용한 커피숍 녹시율에 관한 시뮬레이션 실험연구 (An Experimental Study on the Greenery Ratio of coffee Shop based the Computer Graphics)

  • 안옥희
    • 한국실내디자인학회논문집
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    • 제17호
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    • pp.60-64
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    • 1998
  • The results of simulation on greenery ratio using CG are as follows: arrangement type of optimal condition and greenery ratio were summarized as below as dispersion type and 5% ratio greenery for 20 pairs of assessment items and these assessment items were classified into 5 factors as a result of factor analysis,. These factors were Harmony Animation Atmosphere texture Peculiarity. Verification results of factors differences according to each condition can be. there was no apparent difference among factors in accordance with gender, In case of arrangement type dispersion type was higher than concentration type in all factors. Based on the above results dispersion type was assessed higher than concentration type the most suitable condition of Harmony Factor was 5% dispersion type Animation Factor was 5% dispersion type Animation Factor was 7% dispersion type Atmosphere Factor was 10% dispersion type Texture Factor was 5% concentration type and $\ulcorner$Peculiarity Factor$\lrcorner$was 7% concentration type.

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소각로 운영조건에 따른 연소배가스 특성 연구 (The study of combustion gas characteristic by incinerator operation condition.)

  • 이건주
    • 유기물자원화
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    • 제18권1호
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    • pp.66-72
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    • 2010
  • 본 연구는 경기도 A지역 자원회수시설에서 연소온도의 변화에 따른 NOx, SOx, CO, HCL, DUST의 발생변화와 보일러 배출가스 온도, 보일러 출구산소 농도, 반건식 반응탑 출구온도, 촉매탑온도, 배출가스 온도의 변화를 분석하였다. SOx, CO, Hcl, DUST는 자원회수시설 내의 연소온도가 상승함에 따라 거의 5 ppm 미만의 일정한 값을 유지한 반면 NOx 는 40 ppm에서 70 ppm으로 증가하는 추세였다. 한편 보일러 배출가스 온도와 촉매탑 온도는 일정치를 유지하였으나 보일러 출구의 산소농도는 조금씩 감소하는 결과를 나타내었다.

Alteration of Leaf Surface Structures of Poplars under Elevated Air Temperature and Carbon Dioxide Concentration

  • Kim, Ki Woo;Oh, Chang Young;Lee, Jae-Cheon;Lee, Solji;Kim, Pan-Gi
    • Applied Microscopy
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    • 제43권3호
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    • pp.110-116
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    • 2013
  • Effects of elevated air temperature and carbon dioxide ($CO_2$) concentration on the leaf surface structures were investigated in Liriodendron tulipifera (yellow poplar) and Populus tomentiglandulosa (Suwon poplar). Cuttings of the two tree species were exposed to elevated air temperatures at $27/22^{\circ}C$ (day/night) and $CO_2$ concentrations at 770/790 ppm for three months. The abaxial leaf surface of yellow poplar under an ambient condition ($22/17^{\circ}C$ and 380/400 ppm) had stomata and epicuticular waxes (transversely ridged rodlets). A prominent increase in the density of epicuticular waxes was found on the leaves under the elevated condition. Meanwhile, the abaxial leaf surface of Suwon poplar under an ambient condition was covered with long trichomes. The leaves under the elevated condition possessed a higher amount of long trichomes than those under the ambient condition. These results suggest that the two poplar species may change their leaf surface structures under the elevated air temperature and $CO_2$ concentration condition for acclimation of increased photosynthesis.

Biological nitrogen removal of ammonium-rich industrial wastewater by suspended bacterial growth

  • 임준택;성세현;황석환
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2002년도 생물공학의 동향 (X)
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    • pp.399-402
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    • 2002
  • Industrial wastewater with high ammonium concentration was treated in batch biological systems which was a modified Ludzack- Ettinger process. Up to 78% conversion of $NH_4\;^+-N$ to $NO_x\;^--N$ was achieved in batch culture condition. Under anoxic condition with methanol as the carbon source, the denitrifiers decreased $NO_x\;^--N$ concentration from 608 mg/L to 5.6 mg/L in 22 d. As well as anoxic denitrification of $NO_x\;^-$ to $N_2$, dissimilatory nitrate reduction to ammonium also occurred under the condition as respiratory denitrification.

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도시 대기중에서 반응성 대기오염물질의 농도변화 상관성에 관한 연구 (A Study on the Relationship among the Concentration of Reacting Air Pollutants in Urban Atmosphere)

  • 이화운;김유근;장은숙
    • 한국환경과학회지
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    • 제6권4호
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    • pp.351-357
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    • 1997
  • In the Atmosphere under the various physical and chemical condition different chemical reactions occur and there are a number of air pollutants which are generated by photochemical reaction by absorbing solar energy. Therefor various testing simulation was done as foundation work to develop the numerical model for the prediction of concentration of air pollutants. It was shown change of msjor air pollutants concentration In according to variation of photodissociation speed constant, Kl and Initial condition of air pollutants concentration which plays major role In photochemical reaction. The photochemical reaction model which was used In this study Is found to be useful for understanding relationship among the concentration of reacting air pollutants and the prediction of concentration of air pollutants in urban atmosphere.

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Comparing Bioavailability of Cadmium and Arsenic in Agricultural Soil Under Varied pH Condition

  • Oh, Se Jin;Kim, Sung Chul;Ok, Yong Sik;Oh, Seung Min;Lee, Bup Yeol;Lee, Sang Hwan;Yang, Jae E.
    • 한국토양비료학회지
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    • 제48권1호
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    • pp.57-63
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    • 2015
  • Bioavailability of cadmium (Cd) and arsenic (As) can be different depending on soil pH. For this reason, main purpose of this research was to compare bioavailability of Cd and As in agricultural field under varied soil pH and different extractants. Bioavailable fraction of Cd and As in soil was extracted with $CaCl_2$, $NaNO_3$, DTPA, EDTA, and low molecular weight organic acids (LMWOAs). Soil samples and cultivated crops were collected at the range of soil pH 4.5-8.5 and correlation analysis was conducted between bioavailable fraction of Cd and As in soil and total concentration of Cd and As in crops. Results showed that concentration of Cd and As in acidic soil was ranged $0.002-0.462mg\;kg^{-1}$ and $0.041-4.903mg\;kg^{-1}$ respectively. In alkaline condition, concentration of Cd and As were ranged $0.006-0.351mg\;kg^{-1}$ and $0.039-2.807mg\;kg^{-1}$ respectively. Comparing bioavailable fraction of Cd and As in acidic and alkaline soil condition, higher concentration was measured in acidic condition. Similarly, higher average concentration of Cd and Asin crops was observed in acidic condition (0.398 and $0.751mg\;kg^{-1}$ respectively) than alkaline condition (0.248 and $0.264mg\;kg^{-1}$). Among different extractants, LMWOAs method showed higher correlation ($r^2=0.545$) for Cd in acidic condition indicating that LMWOAs method could be applied for evaluating bioavailability of Cd in acidic soil. However, no high correlation was observed for As in both acidic and alkaline condition. Overall, bioavailable fraction of Cd and As can be higher in acidic condition of soil than alkaline condition resulting higher uptake of Cd and As from soil to crops. Therefore, efficient best management practice (BMPs) for Cd and As in acidic soil should be conducted for minimizing uptake of Cd and As into crops.

Batch 형태 LPCVD법에 의한 폴리실리콘의 인농도 및 Rs 특성에 관한 연구 (A Study on the Phosphorous Concentration and Rs Property of the Doped Polysilicon by LPCVD Method of Batch type)

  • 정양희;김명규
    • 한국전기전자재료학회논문지
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    • 제11권3호
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    • pp.195-202
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    • 1998
  • The LPCVD system of batch type for the massproduction of semiconductor fabrication has a problem of phosphorous concentration uniformity in the boat. In this paper we study an improvement of the uniformity for phosphorous concentration and sheet resistance. These property was improved by using the nitrogen process and modified long nozzle for gas injection tube in the doped polysilicon deposition system. The phosphorous concentration and its uniformity for polysilicon film are measured by XRF(X-ray Fluorescence) for the conventional process condition and nitrogen process. In conventional process condition, the phosphorous concentration, it uniformity and sheet resistance for polysilicon film are in the range of 3.8~5.4$\times$10\ulcorner atoms/㎤, 17.3% and 59~$\Omega$/ , respectively. For the case of nitrogen process the corresponding measurements exhibited between 4.3~5.3$\times$10\ulcorner atoms/㎤, 10.6% and 58~81$\Omega$/ . We find that in the nitrogen process the uniformity of phosphorous concentration improved compared with conventional process condition, however, the sheet resistance in the up zone of the boat increased about 12 $\Omega$/ . In modified long nozzle, the phosphorous concentration, its uniformity and sheet resistance for polysilicon films are in the range of 4.5~5.1$\times$10\ulcorner atoms/㎤, 5.3% and 60~65$\Omega$/ respectively. Annealing after $N_2$process gives the increment of grain size and the decrement of roughness. Modification of nozzle gives the increment of injection amount of PH$_3$. Both of these suggestion result in the stable phosphorous concentration and sheet resistance. The results obtained in this study are also applicable to process control of batch type system for memory device fabrication.

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보관상태가 자동차용 고분자전해질 연료전지의 성능 감소에 미치는 영향 (Effects of Storage Condition on Degradation of Automotive Polymer Electrolyte Membrane Fuel Cells)

  • 조은애
    • 전기화학회지
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    • 제13권4호
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    • pp.277-282
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    • 2010
  • 자동차용 고분자전해질 연료전지의 열화는 시동 또는 정지 시에 'reverse-current condition'이라 불리는 현상에 의해 촉진된다. 연료전지 자동차의 운전 종료 후 장시간동안 주차를 해 두면, 대기 중의 공기가 스택 내로 서서히 유입되어 시간이 경과함에 따라 산소분압이 점차 높아져 궁극적으로는 연료극과 공기극의 유로가 모두 공기로 충진된다. 이때 재시동하면서 연료극으로 수소가 공급되면, 연료극 유로 내에 수소와 공기가 공존하게 되고, 연료극에 공기가 존재하는 부위의 공기극에 1.4 V 이상의 높은 전압이 발생하는데, 이를 reverse-current condition 이라고 하며 공기극의 탄소담지체와 백금 촉매 산화의 원인으로 작용한다. 본 연구에서는 재시동시 스택 내에 존재하는 산소의 농도에 따른 열화 현상을 규명하고자 하였다.

온열환경과 인삼(Panax Ginseng)이 Rat의 체온, 혈액학적 변화, 면역반응에 미치는 영향 (Effect of Heating Condition and Panax Ginseng on Body Temperature, Hematological Changes, and Immune Response in Rat)

  • 이서라;이인희;김민지;류재환
    • 대한한방내과학회지
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    • 제35권1호
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    • pp.59-69
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    • 2014
  • Objectives : This study was designed to test the effect of heating condition and Panax ginseng on body temperature, hematologicala changes, and immune response. Methods : The extract from Panax ginseng was made by the pharmacy department of Kyung Hee Oriental Medical Hospital. The animals were divided into four groups; control, room temperature Panax ginseng (G), $28^{\circ}C$ heating, and $28^{\circ}C$ heating Panax ginseng (heating G). Each group has 8 Sprague-Dawley rats. We measured body weight & temperature twice a week. After 2 weeks of experiment, serum lipid level, WBC, differential count, lymphocyte proliferation and immune cytokine concentration were measured. Results : 1. Simultaneous application of heating condition and Panax ginseng induced decreased body weight and increased body temperature. 2. Simultaneous application of heating condition and Panax ginseng induced decreased AST, ALT and BUN. 3. Simultaneous application of heating condition and Panax ginseng tended to decrease TNF-${\alpha}$ concentration, while application of room temperature and Panax ginseng tended to increase TNF-${\alpha}$ concentration. Conclusions : Simultaneous application of heating condition and Panax ginseng decreseas body weight, increases, body temperature and has a tendency to decrease TNF-${\alpha}$ concentration.