• 제목/요약/키워드: Intermediate products

검색결과 380건 처리시간 0.027초

난분해 PAHs의 화학적산화에 의한 유사기질동시대사 (Analogue Substrate Cometabolism by Chemical Oxidation of Recalcitrant PAHs)

  • 류선정;박갑성
    • 한국토양환경학회지
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    • 제3권3호
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    • pp.87-92
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    • 1998
  • The effect of chemically oxidized intermediates of Polynuclear Aromatic Hydrocarbon (PAH) compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal The chemical oxidation products can serve as a structually similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

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치면열구전색술 - Advanced technique (Pit and fissure sealing - Advanced technique)

  • 이상호
    • 대한치과의사협회지
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    • 제49권1호
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    • pp.22-32
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    • 2011
  • This paper reviewed the following subheadings and a few selected references in each section were discussed: ${\cdot}$ Sealant placed over caries; is it possible? Initial caries which is not sticky during proving is possible to be placed with sealants. ${\cdot}$ Prophylaxis of fissure; which method is most effective? Mechanical preparation with fissurotomy or resin polishing bur is one of the most effective method to clean the pit and fissure. ${\cdot}$ Glassionomer cement as a sealant; GIC, wheather it released fluoride or not, cannot be as cost-effective as resin-based sealants. ${\cdot}$ Sealant products; Color(white vs opaque), fluoride(containing vs not), filler component(filled vs non-filled) do not influenced the quality and retention of sealants. ${\cdot}$ Use of intermediate bonding agent to improve retention; Intermediate bonding may increase the retention rate of sealants ${\cdot}$ Penetration method of sealants; Several methods including waiting before light curing are recommended.

Ferrate(VI)를 이용한 퍼클로로에틸렌의 분해특성 연구 (Degradation of perchloroethylene by ferrate(VI))

  • 김일규
    • 상하수도학회지
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    • 제29권1호
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    • pp.39-46
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    • 2015
  • The degradation characteristics of perchloroethylene by ferrate(VI) oxidation have been studied. The degradation efficiency of perchloroethylene in aqueous solution was investigated at various values of ferrate(VI) dosage, pH, initial concentration of perchloroethylene and aqueous solution temperature. GC-ECD has been used to analyze the changes of perchloroethylene concentration. The optimum conditions of perchloroethylene degradation were obtained at pH 7.0 and $25^{\circ}C$ of aqueous solution temperature. Also, the experimental results showed that perchloroethylene removal efficiency increased with the decrease of initial concentration of perchloroethylene. Lastly intermediate products were identified by GC-MS techniques. Trichloroethylene and chloroform were identified as reaction intermediates.

Sandwich Intermediate Sitting-atop Complexation between Free Base meso-tetraarylporphyrins and Tellurium(IV) chloride

  • Dehghani, Hossein;Bakhshayesh, Sara;Shaterian, Maryam;Motamedi, Leila
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.815-818
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    • 2010
  • Free base meso-tetraarylporphyrins ($H_2T(X)PP$) react with tellurium(IV) chloride ($TeCl_4$) in mild conditions for formation sandwich intermediate sitting-atop (i-SAT) complexes, [$TeCl_4(H_2T(X)PP)_2$]. $^1H$ NMR, $^{13}C$ NMR, UV-vis, FT-IR and elemental analysis were used for characterization of the products. In the proposed structure of the i-SAT complexes, four pyrroles of each porphyrin ring are tilted alternatively up and down and this appropriates suitable orientation of lone pairs of two pyrrolenine nitrogens for electron donation to a tellurium center. $^1H$ NMR and FT-IR results showed that in the produced complex, hydrogen atoms of porphyrin macrocycles remained on the pyrrole nitrogens.

PAHs 오영 토양의 Fenton 보조 동시산화 (Fenton Reaction Assisted Cooxidation for PAHs Contaminated Soils)

  • 류선정;박갑성
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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    • pp.53-60
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    • 1998
  • The effect of chemically oxidized intermediated of PAH compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal. Dehydrogenase activities for the oxidized PAH studies ware enhanced two to five folds to the unoxidized PAHs studies. The chemical oxidation products can serve as a structually very similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

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Kinetics of the Zn(Ⅱ)-Catalyzed Hydrolysis of 2-Acetylpyridineketoximyl Diphenyl Phosphate

  • 서정훈;김경일
    • Bulletin of the Korean Chemical Society
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    • 제6권4호
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    • pp.230-233
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    • 1985
  • Kinetic data of the Zn(Ⅱ) ion-catalyzed hydrolysis of 2-acetylpyridineketoximyl acetate (S) are measured. The reaction proceeds through the accumulation of an intermediate (I). 2-Acetylpyridineketoxime (Ox) is released in the breakdown step of I. Phenol is not formed as a part of the products, and, therefore, diphenyl phosphate and Ox are produced by the breakdown of I. Based on the dependence of the rates for the formation and the breakdown of I on [Zn(Ⅱ)] and pH, and considering the UV spectral properties of I, the structure of I is tentatively assigned as the penta-covalent intermediate formed by the addition of a water molecule to S.

분산이질환경에서 중소기업형 FMS공유구조에 대한 연구 (A Study on the Sharing Architecture of FMS for Small and Medium Enterprises on Distributed Heterogeneous Environments)

  • 박제웅;김원중
    • 한국해양공학회지
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    • 제17권5호
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    • pp.82-87
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    • 2003
  • A practical method to investigate the sharing architecture of FMS, for small and medium enterprises, on distributed heterogeneous environmental conditions is investigated. Because the industrial FMS model requires a reasonable size for actual work-site flexible operation, the initial facility expense is very heavy. The support for flexible cooperation of FMS, with some external different FMS, can reduce expenditures and provide greater functionality. While most FMS provide their operation process using an adequate mechanism, when used in isolation, such as island of automation, there is increasing demand for FMS that can cooperate. By exchanging intermediate products and information with other external FMS, products can be produced that cannot be produced alone, such as those that require various processes. This study first considers the sharing architecture of FMS for small and medium enterprises, and investigates the effects of the general sharing architecture of FMS on distributed heterogeneous environments, by using transducer approach to agentification. In this study, set-up station or in-out station takes charge of the gateway of intermediate products, and routes them among distributed heterogeneous FMS plants. The transducer approach is applied to web agent and set-up agent established interfaces, with system controller and setup controller. In this study, the FMS-established sharing architecture is able to obtain not only the internal flexibility, but also the external flexibility.

In situ ruminal degradation characteristics of dry matter and crude protein from dried corn, high-protein corn, and wheat distillers grains

  • Lee, Y.H.;Ahmadi, F.;Choi, D.Y.;Kwak, W.S.
    • Journal of Animal Science and Technology
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    • 제58권9호
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    • pp.33.1-33.7
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    • 2016
  • Background: The continuing growth of the ethanol industry has generated large amounts of various distillers grains co-products. These are characterized by a wide variation in chemical composition and ruminal degradability. Therefore, their precise formulation in the ruminant diet requires the systematic evaluation of their degradation profiles in the rumen. Methods: Three distillers grains plus soluble co-products (DDGS) namely, corn DDGS, high-protein corn DDGS (HP-DDGS), and wheat DDGS, were subjected to an in situ trial to determine the degradation kinetics of the dry matter (DM) and crude protein (CP). Soybean meal (SBM), a feed with highly degradable protein in the rumen, was included as the fourth feed. The four feeds were incubated in duplicate at each time point in the rumen of three ruminally cannulated Hanwoo cattle for 1, 2, 4, 6, 8, 12, 24, and 48 h. Results: Wheat DDGS had the highest filterable and soluble A fraction of its DM (37.2 %), but the lowest degradable B (49.5 %; P < 0.001) and an undegradable C fraction (13.3 %; P < 0.001). The filterable and soluble A fraction of CP was greatest with wheat DDGS, intermediate with corn DDGS, and lowest with HP-DDGS and SBM; however, the undegradable C fraction of CP was the greatest with HP-DDGS (41.2 %), intermediate with corn DDGS (2.7 %), and lowest with wheat DDGS and SMB (average 4.3 %). The degradation rate of degradable B fraction ($%\;h^{-1}$) was ranked from highest to lowest as follows for 1) DM: SBM (13.3), wheat DDGS (9.1), and corn DDGS and HP-DDGS (average 5.2); 2) CP: SBM (17.6), wheat DDGS (11.6), and corn DDGS and HP-DDGS (average 4.4). The in situ effective degradability of CP, assuming a passage rate of $0.06h^{-1}$, was the highest (P < 0.001) for SBM (73.9 %) and wheat DDGS (71.2 %), intermediate for corn DDGS (42.5 %), and the lowest for HP-DDGS (28.6 %), which suggests that corn DDGS and HP-DDGS are a good source of undegraded intake protein for ruminants. Conclusions: This study provided a comparative estimate of ruminal DM and CP degradation characteristics for three DDGS co-products and SBM, which might be useful for their inclusion in the diet according to the ruminally undegraded to degraded intake protein ratio.

Next Generation Dairy Processing Science and Technology: Functional and Rational in Dairy Industry

  • Charchoghlyan, Haykuhi
    • Journal of Dairy Science and Biotechnology
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    • 제33권3호
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    • pp.167-170
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    • 2015
  • The dairy industry, as part of the broader agricultural sector, is classified as a basic industry to the Korea economy. Basic industries provide income to a region by producing an output, purchasing production inputs, services and labor. An integrated, multidisciplinary approach for the next generation of dairy products with added health benefits represent the direct economic contribution. The commercialization of "nutritional" functional foods can only be successful if the consumer is confident in the scientific validity of the claims. Modern biotechnologies such as genomics, genetic expression and biomarkers of health performance suggested to whole dairy products, such as fluid milk, butter, cheese, ice cream and frozen dessert products (German, 1999). The following definition makes the point that dairy products can provide a nutritional value beyond the basic nutritional requirements: 1) The dairy industry has the opportunity to improve the health and well-being of its customers and/or to reduce their risk of disease through dairy products with added activities. 2) Functional dairy products are those that can be demonstrated to benefit target functions in the body in a way that improves the state of health and /or reduces the risk of disease. They are food products that are consumed as part of a normal diet rather than pills or supplements. 3) Dairy products based on functionality will need to link the scientific basis of such functionality to the communication of its benefit to the general public. 4) Both the efficacy and the safety of the food components with health benefits will require evidence based on the measurement of scientific biomarkers relevant to their biological responses and health end points. 5) Sound evidence from human studies based on intermediate health end points using accepted biomarkers will provide the basis for promotional messages divided into two categories-enhanced function and reduced risk of disease. 6) Success in solving key scientific and technological challenges will only be achieved by interdisciplinary research programs to exploit the scientific concepts in functional dairy science.

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Triglycine 수용액에 미치는 감마선의 영향 3. 감마선에 의한 분해산물에 관하여 (The Effect of Gamma-Irradiation on Aqueous Solutions of Triglycine 3. Mechanism for Gamma-ray Induced Degradation Products)

  • 강만식
    • 한국동물학회지
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    • 제7권2호
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    • pp.1-5
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    • 1964
  • 산소 용존하의 triglycine 수용액을 ${\gamma}-선으로$ 조사하여 carbonly 화합물, glycine, ammonia, ECO_2$ 및 수소를 검출하였다. 이 수용액계에서 일어나는 방사선화학반응을 초과정과 분해산물을 가지고 논의하였다. Triglycine 분자는 먼저 중간생성물을 이루게 되고 이것이 carbonyl 화합물과 acid amide 로 분해하게 된다. 이들은 일차적 또는 이차적으로 free radical 의 작용에 의하여 acetamide, glycie, glyoxylic acid, formic acid, oxalic acid, ammonia 및 ECO_2$ 로 분해하게 된다. 또한 radical-radical 결합에 의하여 생성물이 생길 미확인반응의 가능성도 있으며 타당한 물질평행은 앞으로의 연구에 기대한다.

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