• 제목/요약/키워드: CO2 production

검색결과 3,849건 처리시간 0.037초

사과의 CA저장 중 에틸렌 및 이산화탄소 생성 (Production of Ethylene and Carbon Dioxide in Apples during CA Stroage)

  • 정헌식;최종욱
    • 한국식품저장유통학회지
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    • 제6권2호
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    • pp.153-160
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    • 1999
  • 후지 사과의 CA 저장 효과를 생리화학적으로 구명하기 위해 저장 조건에 따른 에틸렌과 이산화탄소 생성 및 이들의 연관성 그리고 과육경도와 과피색의 변화를 조사하였다. 저장 산소농도가 낮을수록 ACC oxidase 활성이 억제되어 내부 에틸렌 농도가 낮게 유지되었다. 특히 1% $O_2$+l% $CO_2$ 조건에서는 내부 에틸렌 농도가 1 ppm 이하로 유지되었으며 저장 후 2$0^{\circ}C$의 air에서도 거의 변화가 없었다. 에틸렌 생성에 고농도 이산화탄소의 영향은 구성 산소농도에 의존적이어서 1% 산소에서는 효과가 없거나 생성 증가 효과를, 3% 산소에서는 생성 억제효과를 나타내었다. 내부 에틸렌 농도와 에틸렌 방출량은 밀접한 상관관계을 나타내었다. 내부 이산화탄소 농도도 이산화탄소 방출량과 밀접한 상관관계를 나타내었으며 저장 산소농도가 가장 낮은 조건인 1% $O_2$+l% $CO_2$에서 가장 낮게 유지되었고 저장 후의 증가폭은 다른 조건들과 차이가 없었다. 저장조건에 따른 에틸렌과 이산화탄소 생성량의 연관성은 CA 저장 사과와 단기간 air 저장 사과에서는 존재하였으나 장기간 air 저장 사과에서는 보이지 않았다. 사과의 과육경도와 과피의 녹색은 에틸렌과 이산화탄소의 생성이 억제된 저장조건일수록 손실이 적었다.

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Enhancement of Laccase Production from Wood-Rotting Fungus by Co-Culture with Trichoderma longibrachiatum

  • Jung, Hyun-Chae
    • Journal of the Korean Wood Science and Technology
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    • 제47권2호
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    • pp.210-220
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    • 2019
  • This work aimed to evaluate the influence of culture conditions on laccase production in the co-culture of wood-rotting fungus with Trichoderma sp. The effects of infection extent, infection time, and culture filtrate of Trichoderma sp. on the laccase production by wood-rotting fungus in co-culture were examined. T. rubrum LKY-7 and T. longibrachiatum were selected as fungi which are effective in co-culture for laccase production. A significant increase in laccase activity was observed when T. rubrum LKY-7 was co-cultured with T. longibrachiatum in glucose-peptone liquid medium, yielding an increase of more than 5 times in laccase activity, as compared with control. Laccase production by T. rubrum LKY-7 during co-culturing was significantly influenced by the infection extent and the infection time of T. longibrachiatum. Maximal laccase activity was obtained when T. rubrum LKY-7 culture was infected by T. longibrachiatum after 3 days of cultivation at an inoculum size ratio of 0.5 to 1. The addition of culture filtrate or autoclaved mycelium of T. longibrachiatum to T. rubrum LKY-7 culture did not significantly enhance laccase production by T. rubrum LKY-7 as compared with control (mono cultures of T. rubrum LKY-7).

Synthesis and SAR Studies for the Inhibition of TNF-$\alpha$ Production. Part 2. 2-[3-(Cyclopenthloxy)4-Methoxyphenyl]-Substituted-1-Isoindolinone Derivatives

  • Park, Joon-Seok;Moon, Seong-Cheol;Baik, Kyung-Up;Cho, Jae-Youl;Yoo, Eun-Sook;Byun, Young-Seok;Park, Myung-Hwan
    • Archives of Pharmacal Research
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    • 제25권2호
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    • pp.137-142
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    • 2002
  • This study describes the synthesis and in vitro evaluation of 2-[3- (Cyclopenthloxy) 4-Methoxyphenyl] - Substituted-1-Isoindolinone derivatives substituted on benzene moiety of isoindoline ring for the inhibition of $TNF-{\alpha}$ production. From this study, we have found the 6-C position on isoindolinone ring is an optimal derivatization site. Among the compounds synthesized, 6-ammo-2-[3-(cyclopentyloxy)-4-methoxyphenyl]-1-isoindolinone (6) was the most potent in inhibitory activity of $TNF-{\alpha}$ production in LPS-stimulated RAW264.7 cells.

Assessment and Optimization of Xylanase Production Using Mono-Culture and Co-Cultures of Bacillus subtilis and Bacillus pumilus

  • Chitranshu Pandey;Neeraj Gupta
    • 한국미생물·생명공학회지
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    • 제51권1호
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    • pp.59-68
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    • 2023
  • Xylanase is an industrially relevant enzyme used for the production of xylobiose and xylose. Various methods are used to enhance the microbial yield of xylanase. In the present study, co-culturing of Bacillus subtilis and Bacillus pumilus were investigated using submerged fermentation for xylanase production, which was markedly increased when sal, sagwan, newspaper, wheat bran, and xylan were used as single carbon sources. Maximum xylanase production was reported after 5 days of incubation in optimized media at pH 7.0 and 37℃, resulting in 2.69 ± 0.25 µmol/min by coculture. The 1:1 ratio of sal and sagwan in optimized production media was shown to be suitable for xylanase synthesis in submerged fermentation (SMF). In comparison to mono-culture using B. pumilus and B. subtilis, co-culturing resulted in an overall 3.8-fold and 2.15-fold increase in xylanase production, respectively.

Synthesis and Structure-Activity Relationships of Novel Compounds for the Inhibition of TNF-$\alpha$ Production

  • Park, Joon-Seok;Baik, Kyong-Up;Son, Ho-Jung;Lee, Jae-Ho;Lee, Se-Jong;Choi, Jae-Youl;Park, Ji-Soo;Yoo, Eun-Sook;Byun, Young-Seok;Park, Myung-Hwan
    • Archives of Pharmacal Research
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    • 제23권4호
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    • pp.332-337
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    • 2000
  • This study describes the synthesis, in vitro evaluation and molecular modeling study of novel compounds for the inhibition of TNF-$\alpha$production, Among these compounds, 2-[3-(cyclopentyloxy)-4-methoxyphenyl]-1-isoindolinone (9) was selected as a lead compound and its pyridine derivative 10 was more potent in activity and safer than rolipram.

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The water-energy-food resources and environment: Evidence from selected SAARC countries

  • Mansoor, Abdul;Sultana, Baserat;Shafique, Saima;Zaman, Khalid
    • Advances in Energy Research
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    • 제6권1호
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    • pp.1-15
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    • 2019
  • The objective of the study is to examine the relationship between water resources, energy demand, food production, and environmental pollutants in selected SAARC nations, namely, Bangladesh, India, Pakistan, and Sri Lanka, during the period of 1990-2016. The results show that water, energy, and food (WEF) resources substantially affected air quality in the form of high mass carbon emissions, fossil fuel energy demand, methane discharges, nitrous oxide emissions, and greenhouse gas emissions in these countries. Food production and food deficit largely increase $CO_2$ emissions due to unsustainable production and malnutrition, while land use under cereal production increases $CH_4$ and $N_2O$ emissions. Electricity production escalates $CO_2$ emissions and fossil emissions across countries. The results support the carbon EKC hypothesis, while monotonic increasing function exists in case of fossil fuel energy. The study emphasizes the need to ensure environmental sustainability agenda by adopting cleaner production technologies in WEF resources.

수소생산 공정에서의 CO2 배출처 및 유효포집기술 분석 (Analysis of CO2 Emission and Effective CO2 Capture Technology in the Hydrogen Production Process)

  • 우경택;김봉규;소영석;백문석;박승수;정혜진
    • 한국가스학회지
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    • 제27권3호
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    • pp.77-83
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    • 2023
  • 급격한 산업화에 따른 에너지 사용량의 증가로 대기 중 이산화탄소(CO2)의 농도가 증가하여 기후변화가 가속화되고 있다. 여기에 대응하기 위해 에너지 패러다임 전환이 필요하고, 그 일환으로 수소(H2)가 주목받고 있다. 하지만 현재 대부분(95%)의 수소가 화석연료 기반의 추출수소로 생성되며, 많은 양의 CO2를 배출하고 있다. 이를 그레이수소라 하는데 여기에 CO2포집·이용·저장(CCUS)기술을 적용하여 CO2 배출량을 줄이면 블루수소가 된다. 상용 CO2 포집기술로는 습식법, 건식법, 분리막법이 있는데 각자 장단점을 가지고 있어 배가스 특성분석이 선행되어야 한다. 수소생산기지에서 배출되는 CO2는 수분제거 시 20%를 상회하고 배출량은 중소규모로 분류되어 습식법 보다 분리막법의 적용이 유리할 것으로 판단된다. 또한, LNG 냉열을 사용할 수 있다면 분리막의 포집성능(선택도)이 향상되어 효율적인 CO2 포집 공정 구현이 가능하다. 본 연구에서는 수소생산기지에서 배출되는 배가스를 분석하고 여기에 적합한 CO2 포집기술에 대한 논의가 이뤄질 것이다.

Nob1e2-[3-(Cyclopentyloxy)-4-Methoxyphenyl]-1-Isoindolinone Derivatives. PartI: Synthesis and SAR Studies for the Inhibition of TNF-$\alpha$ Production

  • Park, Joon-Seok;Baik, Kyong-Up;Cho, Jae-Youl;Yoo, Eun-Sook;Byun, Young-Seok;Park, Myung-Hwan
    • Archives of Pharmacal Research
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    • 제24권5호
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    • pp.367-370
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    • 2001
  • This study describes the synthesis and in vitro evaluation of noble 2-[3-(cyclopentyloxy)-4-methoxyphenyl]-1-isoindolinone Derivatives for the inhibition of TNF-$\alpa$ production. Among these compounds, 2- [3- (Cyclopentyloxy)- 4- methoxyphenyll- 3- methyl -1 - isoindolinone (5) was the most potent in inhibitory activity of TNF-$\alpa$ production in LPS-stimulated RAW264.7 cells.

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수소/이산화탄소/알곤 혼합 연료의 비예혼합 대향류 화염에서 NO 배출 특성 연구 (A Study of NO Fmission Characteristics in a Non-premixed Counterflow Flame with $H_2/CO_2/Ar$ Blended-fuel)

  • 이기만
    • 한국자동차공학회논문집
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    • 제15권4호
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    • pp.146-153
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    • 2007
  • The detailed chemistry with reaction mechanism of GRI 2.11, which consists of 49 species and 279 elementary reactions, have been numerically conducted to investigate the flame structure and NO emission characteristics in a non-premixed counterflow flame of blended fuel of $H_2/CO_2/Ar$. The combination of $H_2,\;CO_2$, and Ar as fuel is selected to clearly display the contribution of hydrocarbon products to flame structure and NO emission characteristics due to the breakdown of $CO_2$. Radiative heat loss term is involved to correctly describe the flame dynamics especially at low strain rates. All mechanisms including thermal, $NO_2,\;N_2O$, and Fenimore are also taken into account to separately evaluate the effects of $CO_2$ addition on NO emission characteristics. The increase of added $CO_2$ quantity causes flame temperature to fall since at high strain rates diluent effect is prevailing and at low strain rates the breakdown of $CO_2$ produces relatively populous hydrocarbon products and thus the existence of hydrocarbon products inhibits chain branching. It is also found that the ratio of the contribution by Fenimore mechanism to that by thermal mechanism in the total mole production rate becomes much larger with increase in the $CO_2$ quantity and strain rate, even though the absolute quantity of NO production is deceased. Consequently, as strain rate and $CO_2$ quantity increase, NO production by Fenimore mechanism is remarkably augmented.

메탄-공기 대향류확산화염에서 $CO_2$$H_2O$의 첨가가 화염구조와 NOx배출특성에 미치는 화학적 영향 (Chemical effects of added $CO_{2}$ and $H_{2}O$ to major flame structures and NOx emission characteristics in $CH_4$/Air Counterflow Diffusion Flames)

  • 황동진;박정;이경환;길상인
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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    • pp.129-136
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    • 2003
  • Numerical study with momentum-balanced boundary conditions has been conducted to grasp chemical effects of added $CO_{2}$ and $H_{2}O$ to fuel- and oxidizer-sides on flame structure and NO emission behavior in $CH_{4}$/Air counterflow diffusion flames. The dilution with $H_{2}O$ results in significantly higher flame temperatures and NO emission, but dilution with $CO_{2}$ has much more chemical effects than that with $H_{2}O$. Maximum reaction rate of principal chain branching reaction due to chemical effects decreases with added $CO_{2}$. but increases with added $H_{2}O$. The NO emission behavior is closely related to the production rate of OH, CH and N. The OH radical production rate increases with added $H_{2}O$ but those of CH, N decrease. On the other hand the production rates of OR CH and N decrease with added $CO_{2}$. It is found that NO emission behavior is considerably affected by chemical effects of added $CO_{2}$ and $H_{2}O$.

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