• 제목/요약/키워드: Synthetic Utilization

검색결과 129건 처리시간 0.03초

Simultaneous Utilization of Two Different Pathways in Degradation of 2,4,6-Trinitrotoluene by White Rot Fungus Irpex lacteus

  • 김현영;송홍규
    • 미생물학회지
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    • 제38권4호
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    • pp.250-250
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    • 2002
  • This study confirmed that white rot fungus Irpex lacteus was able to metabolize 2,4,6-trinitrotoluene (TNT) with two different initial transformations. In one metabolic pathway of TNT a nitro group was removed from the aromatic ring of TNT. Hydride-Meisenheimer complexes of TNT (H/sup -/-TNT), colored dark redo were confirmed as the intermediate in this transformation by comparison with the synthetic compounds. 2,4-Dinitrotoluene as a following metabolic product was detected, and nitrite produced by denitration of $H^-$-TNT supported this transformation. In the other TNT pathway, nitro groups in TNT were successively reduced to amino groups via hydroxylamines. Hydroxylamino-dinitrotoluenes and amino-dinitrotoluenes were identified as the intermediates. The activity of a membrane-associated aromatic nitroreductase was detected in the cell-free extract of I. lacteus. This enzyme catalyzed the nitro group reduction of TNT with NADPH as a cofactor, Enzyme activity was not observed in the presence of molecular oxygen.

Fixed Bed Study for a Detritiation Adsorber

  • Kim K. R.;Lee M. S.;Paek S.;Yim S. P,;Ahn D. H.;Chung H.;Shim M. H.
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2005년도 Proceedings of The 6th korea-china joint workshop on nuclear waste management
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    • pp.119-125
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    • 2005
  • A method of predicting the tritium concentration in the air leaving an atmospheric detritiation dryer was modeled for designing a fixed bed dryer and preparing an advanced dryer control. In order to quantify the bed utilization and the dynamic capacity against an inlet humidity and a flow rate, a series of quantitative tests based on the break-through behavior were carried out in an isothermal fixed bed of synthetic zeolites such type as molecular sieve 4A, 5A, 13X and mordenite. The amount of water vapor breaking during the adsorption was estimated to give a breakthrough capacity at the various inlet flow rates and humidity conditions. The molecular sieve 13X exhibited a better adsorption performance at a given bed height.

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고해상도 SAR 영상의 활용기술 동향분석 (Investigation of Applications Technology for High Resolution SAR Images)

  • 윤근원;고진우;이용웅
    • 한국군사과학기술학회지
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    • 제13권1호
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    • pp.105-113
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    • 2010
  • SAR(Synthetic Aperture Radar) has characteristics well-suited for the measurement of geophysical parameters during day and night in all weather conditions. Recently, SAR data with high resolution acquired by satellites became available to the public. In such data, many features and phenomena of geometric structure of man-made objects and natural environments become observable. In this paper, we discuss main considerations including geometric distortion and coregistration for efficient utilization of high resolution SAR images. And, various advanced technologies in SAR application fields are introduced.

Adsorption and Desorption Characteristics of Methyl iodide on Silver ion-Exchanged Synthetic Zeolite at High Temperature

  • Park, Geun-Il;Park, Byung-Sun;Cho, Il-Hoon;Kim, Joon-Hyung;Ryu, Seung-Kon
    • Nuclear Engineering and Technology
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    • 제32권5호
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    • pp.504-513
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    • 2000
  • The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver ion-exchanged zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver ion-exchanged level for the effective removal of methyl iodide at temperature up to 38$0^{\circ}C$. The degree of adsorption efficiency of methyl iodide on silver ion-exchanged zeolite is strongly dependent of silver ion-amount and process temperature. The influence of temperature, methyl iodide concentration and silver ion-exchanged level on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It would be facts that the effective silver ion-exchanged level was about 10 wt%, based on the degree of silver utilization for the removal of methyl iodide.

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Simultaneous Utilization of Two Different Pathways in Degradation of 2,4,6-Trinitrotoluene by White Rot Fungus Irpex lacteus

  • Kim, Hyoun-Young;Song, Hong-Gyu
    • Journal of Microbiology
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    • 제38권4호
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    • pp.250-254
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    • 2000
  • This study confirmed that white rot fungus Irpex lacteus was able to metabolize 2,4,6-trinitrotoluene (TNT) with two different initial transformations. In one metabolic pathway of TNT a nitro group was removed from the aromatic ring of TNT. Hydride-Meisenheimer complexes of TNT (H$\^$-/-TNT), colored dark redo were confirmed as the intermediate in this transformation by comparison with the synthetic compounds. 2,4-Dinitrotoluene as a following metabolic product was detected, and nitrite produced by denitration of H$\^$-/-TNT supported this transformation. In the other TNT pathway, nitro groups in TNT were successively reduced to amino groups via hydroxylamines. Hydroxylamino-dinitrotoluenes and amino-dinitrotoluenes were identified as the intermediates. The activity of a membrane-associated aromatic nitroreductase was detected in the cell-free extract of I. lacteus. This enzyme catalyzed the nitro group reduction of TNT with NADPH as a cofactor, Enzyme activity was not observed in the presence of molecular oxygen.

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Forward Mapping of Spaceborne SAR Image Coordinates to Earth Surface

  • Shin, Dong-Seok;Park, Won-Kyu
    • 대한원격탐사학회지
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    • 제18권5호
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    • pp.273-280
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    • 2002
  • This paper describes a mathematical model and its utilization algorithm for calculating the accurate target position on the ellipsoidal earth surface which corresponds to a range-azimuth coordinates of unprocessed synthetic aperture radar (SAR) images. A geometrical model which is a set of coordinate transformations is described. The side-looking directional angle (off-nadir angle) is determined in an iterative fashion by using the model and the accurate slant range which is calculated from the range sampling timing of the instrument. The algorithm can be applied not only for the geolocation of SAR images but also for the high quality SAR image generation by calculating accurate Doppler parameters.

Feeding and Management System to Reduce Environmental Pollution in Swine Production - Review -

  • Han, In K.;Lee, J.H.;Piao, X.S.;Li, Defa
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권3호
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    • pp.432-444
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    • 2001
  • In this manuscript, several effective feeding and management systems to reduce environmental pollution in swine production have been briefly introduced. It is logical that reducing the excretion of nutrients in manure should be the first step to reduce the environmental impact of pig production. it is evident that the excretion of nitrogen and phosphorus can be reduced when more digestible or available feedstuffs are used. Also, it is well known that proper feed processing can reduce anti nutritional factors (ANF) and improve nutrient digestibilities. Supplementation of effective feed additives can reduce excretion of nitrogen and phosphorus due to efficient feed utilization. These include enzymes (e.g., phytase), antibiotics, probiotics, organic acids and growth hormones ($\beta$-agonists and porcine somatotropin). One of the most effective ways to reduce pollutants from swine manure is to use synthetic amino acids in feed manufacturing. Many studies showed that reduction of 2 to 4% unit (U) of dietary protein with supplemental amino acid (AA) could dramatically reduce (15 to 20%) nitrogen excretion. Regarding feeding strategies, it has been recognized that phase feeding regimen could be used to reduce nitrogen and phosphorous excretion by feeding pigs in better agreement with age and physiological state. Feeding barrows and gilts separately, known as split sex feeding, can also decrease excretion of nitrogen and phosphorus. With the increasing concerns on the negative impact of animal production systems on the environment, animal nutritionists and producers should be aware that sustainability of animal agriculture is as important as high production performance. Therefore, some feeding and management strategies described in this manuscript will help to reduce environmental pollution in swine production. Proper combination of feeding regimen and environment-friendly diet formulation through nutritional approach will be more effective to reduce nutrient excretion in swine production system compared to single approach to do so.

리그닌 이양체(二量體) 모델화합물(化合物)의 합성(合成) - Veratrylglycerol-β-vanillylalcohol ether 화합물(化合物) - (Synthesis of Dimeric Lignin Model Compounds - Veratrylglycerol-β-vanillylalcohol ether compounds -)

  • 조국란;황병호
    • Journal of Forest and Environmental Science
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    • 제12권1호
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    • pp.37-44
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    • 1996
  • Veratrylglycerol-${\beta}$-vanillylalcohol ether 결합 (${\beta}$-O-4 linkage)을 갖는 이양체(二量體) 리그닌 모델화합물(化合物)의 합성(合成)하여 각종 리그닌 반응(反應)의 시료(試料)로서 활용(活用)하고자 3,5-dimethoxyacetophenone을 출발물질(出發物質)로 하여 ${\beta}$-ring에 측소(側銷)를 갖는 이양체(二量體) 리그닌 모델화합물(化合物)(I-IV)을 합성(合成)하였고, 융점측정, $^1H(^{13}C)$-NMR 및 Mass 스펙트라에 의하여 그 화학구조(化學構造)를 동정(同定)하였다. 이 합성화합물(合成化合物)중에서 1-(3,4-dimethoxyphenyl)-2-(2'-methoxy-4'-hydroxymethylphenoxy)ropanediol-1,3[IV]는 매우 중요한 리그닌 이양체(二量體) 화합물(化合物)이다. 이러한 리그닌 합성연구(合成硏究)는 기초적(基礎的)인 연구(硏究)의 중요성(重要性) 뿐만아니라 응용면(應用面)에서도 그 활용도(活用度)가 높을 것이다.

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바이오가스에서 CO2/CH4 활용에 관한 반응최적화 연구 (A Study on the Reaction Optimization for the Utilization of CO2 and CH4 from Bio-gas)

  • 고동현;조욱상;백영순
    • 한국수소및신에너지학회논문집
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    • 제27권5호
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    • pp.554-561
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    • 2016
  • Depending on the Bio-gas sources, main component gases of $CH_4$ and $CO_2$ are shown to be variously present in amounts. For the anaerobic digester, The concentration of $CH_4$ and $CO_2$ in the gases are 60~70 and 30~35 vol%. For the landfill gas, $CH_4$ and $CO_2$ are 40~60 and 40~60 vol%. For the food wastes, $CH_4$ and $CO_2$ are 60~80 and 20~40 vol%, respectively. In this study, maximum conversion rates of $CO_2$ were obtained from the variety of concentrations of $CH_4$ and $CO_2$ by the catalysts of reforming reactions. Moreover, in order to get maximum producing amount of synthetic gas, experimental studies were performed to optimize the reaction variables. On the basis of $CH_4$, 243 ml, R [$CH_4/(O2+CO_2)$] value were varied from 0.8 to 1.35, in the study of $CH_4$ and $CO_2$ reforming reactions. It was shown that the optimal results were obtained for 1.35 of R value. And also, at $850^{\circ}C$ and 1 atm, the production rate of synthetic gas was 90% and the conversion rates of $CH_4$ and $CO_2$ were higher than 99% and 90%, respectively.

탑재비행시험 영상을 적용한 통합비행 시뮬레이션 기법 연구 (Study on Integrated-Flight Simulation Method Using CFT Imagery)

  • 정동길;윤효석;박진현
    • 한국시뮬레이션학회논문지
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    • 제27권1호
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    • pp.111-117
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    • 2018
  • 영상탐색기가 적용된 유도무기체계의 경우 영상 추적 성능이 체계 성능에 큰 영향을 미치기 때문에 유도탄 비행 중 강인한 영상 추적 성능을 확보하는 것이 필수적이다. 유도탄의 실사격 비행시험이 실제 영상 추적 성능을 확인하기 위한 가장 확실한 방법이나, 실사격 시험만으로 영상 추적기법을 실험 및 수정/보완할 경우 매우 큰 비용 손실이 발생하게 된다. 따라서 영상탐색기를 유도탄 비행 궤적을 모의할 수 있는 비행체에 탑재 후 추적 성능을 시험하는 탑재비행시험(CFT; Captive Flight Test)을 수행하게 된다. 하지만 탐색기를 탑재하는 항공기가 유도탄의 완벽한 거동을 모의하는 것은 불가능하기 때문에 탑재 비행시험만으로 체계 성능을 확인할 수는 없다. 본 논문에서는 기존 영상추적기법 단독 성능 확인에만 한정되어 있던 탑재비행시험 영상을 통합비행 시뮬레이션에 적용하여 체계 성능 확인이 가능하도록 한 기법 연구 결과에 대하여 기술하였다. 이 연구는 탑재비행시험 영상의 활용도를 증대시킬 뿐만 아니라, 기존 합성영상 기반의 통합비행 시뮬레이션 기법의 사실성을 보완할 수 있어 다양한 측면에서 체계 성능 검증을 가능하게 하였다.