• 제목/요약/키워드: Heterogeneous Products

검색결과 132건 처리시간 0.022초

Synthesis of New Bimetallic Chiral Salen Catalyst Bearing Co(BF4)2 Salt and Its Application in Asymmetric Ring Opening of Epoxide

  • Kim, Yong-Suk;Lee, Choong-Young;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2973-2979
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    • 2010
  • The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.

Polymer Support Immobilized Acidic Ionic Liquid: Preparation and Its Application as Catalyst in the Synthesis of Hantzsch 1,4-Dihydropyridines

  • Jahanbin, Bentolhoda;Davoodnia, Abolghasem;Behmadi, Hossein;Tavakoli-Hoseini, Niloofar
    • Bulletin of the Korean Chemical Society
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    • 제33권7호
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    • pp.2140-2144
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    • 2012
  • A polymer support immobilized acidic ionic liquid was prepared by copolymerization of 3-vinyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate with styrene in the presence of benzoyl peroxide and its primary application as a solid acidic heterogeneous catalyst to the synthesis of Hantzsch 1,4-dihydropyridines through a one-pot three-component reaction of aromatic aldehydes, ethyl acetoacetate and ammonium acetate was investigated. The results showed that this heterogeneous catalyst has high catalytic activity and the desired products were obtained in good to high yields. Moreover, the catalyst was found to be reusable and a considerable catalytic activity still could be achieved after third run.

An Ontology Driven Mapping Algorithm between Heterogeneous Product Classification Taxonomies

  • 김우주;최남혁;최태우
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 2005년도 공동추계학술대회
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    • pp.295-303
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    • 2005
  • Semantic Web and its related technologies have been opening the era of information sharing via Web. In the meantime, there are several huddles to overcome toward the new era and one of the major huddles is information integration issue unless we build and use a single unified but huge ontology which address everything in the world. Particularly in e-business area, information integration problem must be a great concern in search and comparison of products from various internet shopping sites and e-marketplaces. To overcome such an information integration problem, we propose an ontology driven mapping algorithm between heterogeneous product classification and description frameworks. We also perform comparative evaluation of the proposed mapping algorithm against a well-known ontology mapping tool, PROMPT.

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지방질의 과산화와 영양 (Lipid Peroxidation and Its Nutritional Significance)

  • 최홍식
    • 한국식품영양과학회지
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    • 제23권5호
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    • pp.867-878
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    • 1994
  • A general overview of the lipid peroxidation and its nutritional significance are presented ,with emphasis on the reaction mechaisms, peroxidized products, further interaction and nutritional/biological deterioration in a series of oxidative process. Overall mechanism with various factors and elements for initiation , propagation and termination of free radical reaction is reviewed and the primary /secondary products of peroxidized lipids are defined. Since these products are potentially reactive substances that can cause deterioration of proteins /amino acids and vitamins (carotene, tocopherols and ascorbic acid etc), mechanism and actual damages of their deterioration in some foods and biological models are outlined. Especially , chemical changes caused by interaction of peroxidized products (related hydroperoxides, radicals and malonaldehye etc) and protein are emphasized here. And also, the detailed mechanisms on radical scavenging of the these vitamins which are the most prominent natural antioxidants are presented . Additionally , the possible roles of peroxidicaed lipids and their secondary products in the process of aging an carcinogenesis are briefly discussed . However, it is important to not that more detailed and integrated studies on the reaction kinetics, energetics of peroxidation, their decomposed products , biochemical interaction potential damaging/aging / carcinogenic effects, protection from their oxidative spoilage and novel antioxidants in food and heterogeneous biological systems will be essential in order to assessing the implication of lipid peroxidation to human nutrition and health.

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Autoxidation of Cycloalkenes by the System “Molecular Oxygen-bis(acetylacetonato) Cobalt (II) Complex-butyraldehyde”

  • Fang, Zhao;Tang, Rui-Ren;Zhang, Rui-Rong;Huang, Ke-long
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2208-2212
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    • 2009
  • Oxidation of cycloalkenes with $O_2$ promoted by heterogeneous bis(acetylacetonato) cobalt (II) complex catalyst which can be recycled has been performed under mild conditions. It was found that $\beta$-ionone, cyclohexene, 1-methylcyclohexene, and $\alpha$-ionone were efficiently oxidized with $O_2$ in the presence of Co (II) complex and butyraldehyde at $55\;{^{\circ}C}$. A simple treatment of the resulting products led to epoxides as predominant products and a small amounts of allylic oxides, the chemoselectivity for the former being 82.1 - 90.8% with a 70.6 - 98.6% substrate conversion. On the other hand, oxidation of 1-phenylcyclohexene, 1-cyclohex-1-enylethan-1-one, $\alpha$-pinene, and $\beta$-pinene gave allylic oxides as major products.

MultiSAGE 모델과 ESG 지표를 적용한 상품 추천 시스템 개발 (Development of Product Recommendation System Using MultiSAGE Model and ESG Indicators)

  • 김현우;김용준;유길상
    • 인터넷정보학회논문지
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    • 제25권1호
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    • pp.69-78
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    • 2024
  • 최근 소비자들은 환경, 사회, 지배구조 관련 정보를 확인하고 더 나은 사회적 가치와 환경 친화적인 제품을 선택하려는 경향이 증가되고 있다. 본 논문에서는 GraphSAGE와 GAT를 결합한 모델인 MultiSAGE를 활용하여 최근 소비 트렌드인 가치소비에 맞추어 ESG 지표를 적용한 상품 추천 시스템을 제안하였다. 이를 위하여 한국 ESG 기준원에서 수집한 2022년 1,033개 기업의 ESG 등급 데이터와 실제 N기업의 쇼핑의 상품 데이터를 Heterogeneous Graph 형식의 데이터로 바꾸는 데이터 처리 과정과 MultiSAGE를 적용하여 머신 러닝에 적용하고, 특정 상품을 입력하면 그 상품의 친환경 대체재를 추천해주는 추천 시스템을 구현하였다. 구현결과, 소비자들은 기업의 ESG지표를 적용한 제품을 쉽게 비교하여 구매할 수 있고, 이를 통해 사회적 가치와 환경친화적인 제품을 추천하는 시스템에 활용될 것으로 기대한다.

Texturometer에 의한 성상별(性狀別) 식품군(食品群)의 Texture 특성(特性) (Textural Characteristics of Various Food Products by Texturometer)

  • 이영화;이관영;이서래
    • 한국식품과학회지
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    • 제6권1호
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    • pp.42-54
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    • 1974
  • 국내에서 널리 이용되고 있는 26종(種)의 식품을 물리적(物理的) 성상(性狀)에 따른 Oldfield 등의 방법으로 분류하고 General Foods사(社)의 Texturometer에 의하여 그들의 특성(特性)을 측정하였다. 그 결과 gel 상(狀) 식품(食品), 불균일(不均一) gel 상(狀) 식품(食品), 지방(脂肪) emulsion 상(狀) 식품(食品), 세포조직상식품(細胞組織狀食品), 섬유상식품(纖維狀食品), 공극고체상(空隙固體狀) 식품(食品)에 따라 측정최적조건, texturometer curve 및 특성치가 다름을 확인하였다. 각 식품(食品)의 texture 특성은 동일한 제품사이에서도 다양성을 보여주고 있었으며 특히 공극고체상(空隙固體狀) 식품(食品)에서 가장 심한 차이를 나타내었다.

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Middleware Architecture for Open Control Systems in the Distributed Computing Environment

  • Lee, Wongoo;Park, Jaehyun
    • Transactions on Control, Automation and Systems Engineering
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    • 제3권3호
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    • pp.190-195
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    • 2001
  • The advance of computer, network, and Internet technology enables the control systems to process the massive data in the distributed computing environments. To implement and maintain the software in distributed environment, the component-based methodology is widely used. This paper proposes the middleware architecture for the distributed computer control system. With the proposed middleware services, it is relatively easy to maintain compatibility between products and to implement a portable control application. To achieve the compatibility between heterogeneous systems, the proposed architecture provides the communication protocols based on the XML with lightweight event-based service.

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Metal-Free Oxidation of Alcohols to Their Corresponding Carbonyl Compounds Using NH4NO3/Silica Sulfuric Acid

  • Zarei, Amin
    • Bulletin of the Korean Chemical Society
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    • 제33권7호
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    • pp.2149-2155
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    • 2012
  • A metal-free and efficient procedure for the oxidation of alcohols into the corresponding carbonyl compounds has been described using ammonium nitrate in the presence of silica sulfuric acid under mild and heterogeneous conditions. The use of non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are among the advantages of this method.

A Novel Endo-β-1,4-xylanase from Acanthophysium sp. KMF001, a Wood Rotting Fungus

  • Yoon, Sae-Min;Kim, Yeong-Suk;Kim, Young-Kyoon;Kim, Tae-Jong
    • Journal of the Korean Wood Science and Technology
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    • 제46권6호
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    • pp.670-680
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    • 2018
  • Acanthophysium sp. KMF001, a wood rotting fungus, produces a strong crude enzyme complex that efficiently produces simple sugars from wood. The transcriptomic analysis of Acanthophysium sp. KMF001 identified 14 genes for putative glycoside hydrolases. Among them, isotig01043 was expressed heterogeneously in Escherichia coli BL21(DE3), and the expressed protein exhibited an endo-${\beta}$-1,4-xylanase activity which showed the optimum reaction at pH 5.0 and $30^{\circ}C$. The enzyme kinetic values of $K_m$ and $V_{max}$ were 25.92 mg/ml and $0.628{\mu}mole/mg/ml$, respectively. The enzymatic characteristics of the expressed xylanase showed a typical fungal xylanase. However, the bioinformatics analysis suggested that the protein encoded by isotig01043 was a novel xylanase based on a low identity when it was compared with the closest protein in the NCBI database and a similar protein domain with GH16_fungal_Lam16A_glucanase, which had not been earlier suggested as a xylanase.