• 제목/요약/키워드: transformation by-products

검색결과 239건 처리시간 0.022초

화력발전소 비산회를 이용한 제올라이트합성 (Synthesis of zeolite from power plant fly ash)

  • 김재환;연익준;김광렬
    • 환경위생공학
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    • 제12권1호
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    • pp.49-58
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    • 1997
  • A study on the synthesis of zeolite from bituminous coal ESP fly ash as a raw material, which was emitted from the power plant, was carried out to reduce environmental problems and reuse of the industrial wastes. Bituminous coal fly ash was used as the source of silica and alumina. Zeolite was synthesized by hydrothermal reaction in aqueous NaOH solution with sodium aluminate as additive. The objective of this study is to elucidate the effect of several experimental variables on the synthesis of zeolite. The effects of preroasting temperature, mixing speed, leaching alkalinity, and molar ratio of Na$_{2}$O/SiO$_{2}$ and SiO$_{2}$/Al$_{2}$O of the products were investigated. The synthesized zeolite was proved to be NaA, which is known as 4A type, by comparing with SEM images, and X-ray diffraction analysis. And also we know that the transformation of zeolite A take places into other types of zeolites, i.e. Hydroxysodalite, zeolite P, with the variation of leaching alkalinity.

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가중치를 고려한 자동차 서브프레임의 인증 알고리즘 구현 (Development of Registration Algorithm considering Coordinate Weights for Automobile Sub-Frame Assembly)

  • 이광일;양승한;이영문
    • 한국기계가공학회지
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    • 제3권4호
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    • pp.7-12
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    • 2004
  • Inspection and analysis are essential process to determine whether a completed product is in given specification or not. Analysis of products with very complicated shape is difficult to carry out direct comparison between inspected coordinate and designed coordinates. So process called as matching or registrations is needed to solve this problem. By defining error between two coordinates and minimizing the error, registration is done. Registration consists of translation, rotation and scale transformations. Error must be defined to express feature of inspected product. In this paper, registration algorithm is developed to determine pose of sub-frame at assembly with body of automobile by defining error between two coordinates considering geometric feature of sub-frame.

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연면방전 플라즈마를 이용한 톨루엔 처리에 관한 연구 (Toluene Removal Using Surface Discharge Induced Plasma Chemical Process)

  • 부문자;봉춘근;김신도
    • 한국대기환경학회지
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    • 제13권4호
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    • pp.297-305
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    • 1997
  • The experimental study by use of SPCP was fulfilled to remove toluene emitted from various industrial processes. First of all, discharge characteristic was experimented as the change of applied voltage and frequency. Then toluene removal characteristic was tested with the analysis of by-products. As a result, optimum electrical discharge condition was from 20.0 kHz to 25.0 kHz of frequency and from 3.5 kV to 4.0 kV of voltage range. The variation of applied voltage had a more important effect on the removal characteristic of toluene than the frequency variation. The toluene removal efficiency was proportioned to ozone concentration and retention time on discharge plate. It was dropped as increase of toluene concentration, but total treated volume of tolene per power consumption was high. The decomposed toluene was transformed to $CO, CO_2$ and particulates, and the rate of transformation to particulates was higher than CO and $CO_2$ at high toluene concentration. Particulates were increased from 0.017 $\mum$ to 0.3 $\mum$ range of size distribution.

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Factors for Shopping Malls to be Successful in Delhi Ncr (India)

  • Mullick, N.H.
    • 아태비즈니스연구
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    • 제4권1호
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    • pp.25-30
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    • 2013
  • Today a consumer is confused and he looks only for values in relation to the prices spent by him/her in the buying process. He/She relates value in terms product pricing, brand value, his experiences etc. This therefore gives a vast scope for organized retailing that can make products available as per the aspirations of the consumer. For these organized retailers, Shopping Malls are acting as a catalyst and helping them to enhance their growth all over the country. They are providing them the required infrastructure and also helping them to achieve a faster growth. The present study is therefore done visualizing the opportunities available in the Indian market and the issues faced by the mushrooming of Malls in Indian metropolitan cities making their survival difficult due to cut-throat competition. This is also resulting in poor occupation and is not able to find neither the right rentals nor the footfalls.

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Zerovalent Iron에 의한 유기염소계 살충제 Endosulfan의 탈염소화 (Dechlorination of Organochlorine Insecticide, Endosulfan by Zerovalent Iron)

  • 신현수;김택겸;김장억
    • 한국환경농학회지
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    • 제28권2호
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    • pp.202-208
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    • 2009
  • 유기염소계 살충제 endosulfan과 이의 토양 중 주 분해산물인 endosulfan sulfate의 ZVI에 의한 분해정도와 분해산물을 조사하였다. ZVI처리에 의해서 수용액내에서 endosulfan과 endosulfan sulfate는 pH가 낮을수록 분해율이 높았으며 pH 3.0에서 ${\alpha}$-endosulfan은 28%, endosulfan sulfate는 90%정도 분해되었고 acetone/water(50/50, v/v) 용액에서는 ${\alpha}$-endosulfan은 65%, endosulfan sulfate는 92%정도 분해되었다. ZVI에 의해 ${\alpha}$-endosulfan 및 endosulfan sulfate는 분해되어 2개의 미확인 물질을 생성하였다. 반응시간에 따른 반응속도와 반감기를 비교해 보면 endosulfan sulfate가 ${\alpha}$-endosulfan에 비해 빠르게 분해되는 양상을 보였다. ZVI의 처리에 인해 ${\alpha}$-endosulfan과 endosulfan sulfate에서 생성된 2개의 미확인 물질은 GC-MS로 분석한 결과, 하나의 $Cl^-$$H^+$로 치환된 구조이성질체로 나타났다.

화강암의 풍화산물에 대한 기계적 풍화지수의 특성에 관한 연구 (A Study on the Indexes and Properties of Mechanical Weathering to Granite Distributed in Korea)

  • 임종호
    • 대한지리학회지
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    • 제28권2호
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    • pp.99-111
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    • 1993
  • 풍화작용은 여러 영역에 의해 지배를 받고 있으며 지형형성작용 중 가장 기본이 된다. 우리나라와 같이 화강암류로 구성된 지역에서는 다른 암석류로 구성된 지역보다 풍화작용이 활발히 진행되어 풍화산물이 많이 존재한다. 본 연구에서는 화강암 풍화산물이 형성된 영역과 기계적 풍화지수 및 특성을 살펴보았다. 그 결과 토화학적 풍화작용은 clayey gruss에서, 지화학적 풍화는 gruss에서, 쪼개짐작용은 풍화암석에서 강하게 작용하고 있었다. 기계적 풍화지수는 일반적으로 clayey gruss 계통은 5내외이고 gruss는 10내외 정도이었다. 그리고 입자붕괴는 풍화작용과 열수작용에 의해 형성되었으며, 세립질로 구성된 식토계통은 주로 열수영역을 많이 받았고 조립질로 구성된 사토계통은 풍화작용을 강하게 받았다.

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Field Gas-Sparging Tests for In Situ Aerobic Cometabolism of Trichloroethylene(TCE)

  • Kim Young;Istok Jonathan D.;Semprini Lewis;Oa Sung-Wook
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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    • pp.54-56
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    • 2006
  • Single-well-gas-sparging tests were developed and evaluated for assessing the feasibility of in-situ aerobic cometabolism of trichloroethylene (TCE), using propane as a growth substrate. To evaluate transport characteristics of dissolved solutes [sulfur hexafluoride (SF6) or bromide (non-reactive tracers), propane (a growth substrate), ethylene, propylene (nontoxic surrogates to probe for CAH transformation activity), and DO], push-pull transport tests were performed. Mass balance showed about 90% of the injected bromide and about 80% of the injected SF6 were recovered, and the recoveries of other solutes were comparable with bromide and slightly higher than SF6. A series of Gas-Sparging Biostimulation tests were performed by sparging propane/oxygen/argon/SF6 gas mixtures, and temporal ground water samples were obtained from the injection well under natural gradient 'drift' conditions. The decreased time for propane depletion and the longer time to deplete SF6 as a conservative tracer indicate the progress of biostimulation. Gas-Sparging Activity tests were performed. .Propane utilization, DO consumption, and ethylene and propylene cometabolism were well demonstrated. The stimulated propane-utilizers cometabolized ethylene and propylene to produce ethylene oxide and propylene oxide, as cometabolic by-products, respectively. Gas-Sparging Acetylene Blocking tests were performed by sparging gas mixtures including acetylene to demonstrate the involvement of monooxygenase enzymes. Gas substrate degradation was essentially completely Inhibited in the presence of acetylene, and no production of the corresponding oxides was also observed. The Gas-Sparging tests supports the evidences that the successive stimulation of propane-oxidizing microorganisms, cometabolic transformation of ethylene and propylene by the enzyme responsible for methane and propane degradation.

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Sustainable animal agriculture in the United States and the implication in Republic of Korea

  • Inkuk Yoon;Sang-Hyon Oh;Sung Woo Kim
    • Journal of Animal Science and Technology
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    • 제66권2호
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    • pp.279-294
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    • 2024
  • Agriculture has played a significant role in the national economy, contributing to food security, driving economic growth, and safeguarding the dietary habits of the population. Korean agriculture has been compelled to focus on intensive farming due to its limited cultivation area, excessive input costs, and the limitations of agricultural mechanization. In the Republic of Korea (R.O.K), the concept of environmentally friendly animal agriculture began to be introduced in the early 2000s. This concept ultimately aims to cultivate sustainable animal agriculture (SAA) through environmentally friendly production practices, ensuring the healthy rearing of animals to supply safe animal products. Despite the government's efforts, there are still significant challenges in implementing environmentally friendly agriculture and SAA in the R.O.K. Therefore, the objective of this review is to establish the direction that the animal agriculture sector should take in the era of climate crisis, and to develop effective strategies for SAA tailored to the current situation in the R.O.K by examining the trends in SAA in the U.S. The animal agriculture sector in the U.S. has been working towards creating a SAA system where humans, animals, and the environment can coexist through government initiatives, industry research, technological support, and individual efforts. Efforts have been made to reduce emissions like carbon, and improve factors affecting the environment such as the carbon footprint, odor, and greenhouse gases associated with animal agriculture processes for animals such as cattle and pigs. The transition of the U.S. towards SAA appears to be driven by both external goals related to addressing climate change and the primary objectives of responding to the demand for safe animal products, expanding consumption, and securing competitiveness in overseas export markets. The demand for animal welfare, organic animal products, and processed goods has been increasing in the U.S. consumer market. A major factor in the transformation of the U.S. animal agriculture sector in terms of livestock specifications is attributed to environmentally friendly practices such as high-quality feed, heat stress reduction, improvements in reproductive ability and growth period reduction, and efforts in animal genetic enhancement.

산청고령토 입도분리시료들의 광물조성 변화와 그 원인 (Mineralogy of Size Fractions in Sancheong Kaolin and Its Origin)

  • 정기영;김수진
    • 한국광물학회지
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    • 제5권1호
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    • pp.22-31
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    • 1992
  • 습식체질법, 퇴적법 및 원심분리법을 이용하여 얻어진 산청고령토의 9개 입도분리시료에 대하여 체계적인 X-선 회절 및 주사전자현미분석을 시행한 결과, 각 입도분의 점토광물 조성은 고령토의 원조직과 관련이 있음을 알 수 있었다. 침전작용에 의하여 생성된 10-$\AA$ 형 할로이사이트, 일라이트 및 침철석은 미세입도분에 농집되고 모광물의 가상으로 생성된 버미큘라이트는 굵은 입도분에 농집된다. 침전작용 및 가상으로 생성된 다양한 유형의 캐올리나이트는 넓은 입도 분포를 보이지만 일반적으로 굵은 입도분에 농집된다. 굵은 입도분의 할로이사이트는 고령토 원래의 방상구조의 파편들인 할로이사이트 또는 하로이사이트와 캐올리나이트의 덩어리들로 존재하며 분쇄, 초음파처리 및 화학처리에 의해 분산되지 않은 것들이다. 체계적인 습식입도분리 실험에 의하여 10-${\AA}$형 할로이사이트와 캐올리나이트의 구분도 가능하였다. 버미큘라이트와 캐올리나이트 등의 굵은 광물은 2${\mu}m$ 이하의 점토입도분에서는 검출되지 않는 반면 일라이트 및 침철석은 그 양이 적은 경우 원시료만의 X-선 회절분석에서는 검출되지 않는다. 따라서 고령토의 광물조성을 이해하기 위해서는 체계적인 습식입도분리 실험이 필수적이다.

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Agricultural Biotechnology in Canada: From Lab to Commercialization

  • Mclaughlin, Murray
    • 식물조직배양학회지
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    • 제24권4호
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    • pp.189-195
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    • 1997
  • Twenty six per cent of Canada's core biotech companies are Ag-biotechnology, compared with five per cent in the United States. Activities include the use of microorganisms, plant cells to create commercially viable products, and transformation of plants to improve specific qualities. Goals ate to increase the world's food supply, enable crops and animals to resist pests and diseases, increase the nutritional content of food, and improve production efficiency. I believe that there are business opportunities in the agriculture sector for Canada and other countries such as Korea to collaborate. These are research to research : institute to institute: business to business, and combinations of these areas. However, for these opportunities to become a reality we need to increase our awareness of each other's activities and needs. My presentation today was not designed with specifics, but to encourage some strategic thinking by both countries on how we can do business together in agriculture and biotechnology.

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