• Title/Summary/Keyword: Heterogeneous Products

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Hydrogenolysis of CFC-113a$(CF_3CCl_3)$ Catalyzed by Heterogeneous Catalysts in the Liquid Phase (불균일 촉매를 이용한 CFC-113a$(CF_3CCl_3)$의 액상 가수소 분해 반응)

  • Jo, Uk Jae;Lee, Ik Mo;Kim, Hong Gon;Kim, Hun Sik
    • Journal of the Korean Chemical Society
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    • v.38 no.9
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    • pp.695-700
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    • 1994
  • Hydrogenolysis reactions of CFC-113a catalyzed by various heterogeneous catalysts $(Rh/Al_2O_3,\;Pd/C,\;Ni,\;Al_2O_3,\;Active\;carbon)$ were investigated in the liquid and gas phases. In the liquid phase reaction, different catalysts showed different activities, but all catalysts used gave high selectivities toward HCFC-123 over 95%. It was noticeable that the neutral $Al_2O_3$ showed both a high activity and a selectivity in the liquid phase reaction. In the gas phase reaction, transition metals on carbon(Pd/C, Pt/C) were so active for hydrogenolysis of CFC-113a that they even catalyzed the production reaction of overhydrogenated compounds such as $HCFC-133a(CF_3CH_2Cl)\;and\;HFC-143a(CF_3CH_3)$. $Al_2O_3$, which showed the high activity in the liquid phase reaction, did not show a remarkable activity. When $Al_2O_3$ was used in the liquid phase reaction, the hydrogenolysis of CFC-113a proceeded without any side products in THF. However, the same reaction in MeOH produced side products, such as $CH_3OCH_3\;and\;CH_3CH_2OCH_3$ from solvent. Based on this result, including heterogeneous catalysts, it was concluded that the solvent played an important role in the liquid phase reaction.

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A Study on Generalization of Security Policies for Enterprise Security Management System (통합보안관리시스템을 위한 보안정책 일반화에 관한 연구)

  • Choi, Hyun-H.;Chung, Tai-M.
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.823-830
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    • 2002
  • Enterprise security management system proposed to properly manage heterogeneous security products is the security management infrastructure designed to avoid needless duplications of management tasks and inter-operate those security products effectively. In this paper, we propose the model of generalized security policies. It is designed to help security management build invulnerable security policies that can unify various existing management infrastructures of security policies. Its goal is not only to improve security strength and increase the management efficiency and convenience but also to make it possible to include different security management infrastructures while building security policies. In the generalization process of security policies. we first diagnose the security status of monitored networks by analyzing security goals, requirements, and security-related information that security agents collect. Next, we decide the security mechanisms and objects for security policies, and then evaluate the properness of them on the basis of security goals, requirements and a policy list. With the generalization process, it is possible to integrate heterogeneous security policies and guarantee the integrity of them by avoiding conflicts or duplications among security policies. And further, it provides convenience to manage many security products existing in large networks.

3-D Information Model for High-speed Railway Infrastructures (고속철도시설물을 위한 3차원정보모델)

  • Shim, Chang-Su;Kim, Deok-Won;Youn, Nu-Ri
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.241-246
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    • 2008
  • Design of a high-speed railway line requires collaboration of heterogeneous application systems and of engineers with different background. Object-based 3D models with metadata can be a shared information model for the effective collaborative design. In this paper, railway infrastructure information model is proposed to enable integrated and inter-operable works throughout the life-cycle of the railway infrastructures, from planning to maintenance. In order to develop the model, object-based 3-D models were built for a 10km railway among Korea high-speed railway lines. The model has basically three information layers for designers, contractors and an owner, respectively. Prestressed concrete box-girders are the most common superstructure of bridges. The design information layer has metadata on requirements, design codes, geometry, analysis and so on. The construction layer has data on drawings, real data for material and products, schedules and so on. The maintenance layer for the owner has the final geometry, material data, products and their suppliers and so on. These information has its own data architecture which is derived from similar concept of product breakdown structure(PBS) and work breakdown structure(WBS). The constructed RIIM for the infrastructures of the high-speed railway was successfully applied to various areas such as design check, structural analysis, automated estimation, construction simulation, virtual viewing, and digital mock-up. The integrated information model can realize virtual construction system for railway lines and dramatically increase the productivity of the whole engineering process.

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A Research and development of integrated Platform for data security between different smart home devices (안드로이드 기반 스마트 홈 디바이스의 통신 데이터 보안 및 통합 관리 플랫폼 연구개발)

  • Lee, Jeong-Gi;Yang, Chul-Seung;Kim, Jun-Ha;Kim, Kang-Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.5
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    • pp.1173-1179
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    • 2015
  • In this paper is given to implements the Android-based integration platform to provide convenience for gender development and scalability , easy access for the user. Sensor-based smart home-related products have a different way of the data exchange so platform can be integrated easily and connect heterogeneous network products and external data transmission security processing for data communication and supported to enable the integration

Development of Molecular Biological Methods to Analyze Bacterial Species Diversity in Freshwater and Soil Ecosystems

  • Lee, Dong-Hun;Noh, Sung-Ae;Kim, Chi-Kyung
    • Journal of Microbiology
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    • v.38 no.1
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    • pp.11-17
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    • 2000
  • A new method was developed for the rapid analysis of diverse bacterial species in the natural environment. Our method is based on PCR-single-strands-conformation polymorphism (PCR-SSCP) and selective isolation technique of single-stranded DNA. Variable V3 fragments of 16S rDNA were amplified by PCR with bacterial 16S rDNA primers, where one of the primers was biotinylated at the 5'-end. The biotinylated strands of the PCR products were selectively isolated by using streptavidin paramagnetic particles and a magnetic stand, to prevent SSCP analysis producing heteroduplexes from heterogeneous DNA samples. The selected strands were separated by electrophoresis on a polyacrylamide gel, and detected by silver staining. Analysis of PCR products from 8 bacterial strains demonstrated their characteristic DNA band patterns. In addition, changes in the structure of the bacterial community and species diversity in the microcosm treated with phenol could be monitored. After 3 weeks of incubation, phenol and its intermediate, 2-hydroxy-muconic-semialdehyde, were degraded by indigenous bacteria. These dominating bacterial populations were identified as strong bands on an SSCP gel. Therefore, this study provides useful tools for microbial community analysis of natural habitats.

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Characterization of Low-Temperature Enzymatic Reactions through Heterologous Expression and Functional Analysis of Two Beta-Glucosidases from the Termite Symbiotic Bacterium Elizabethkingia miricola Strain BM10

  • Dongmin LEE;Tae-Jong KIM
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.4
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    • pp.270-282
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    • 2023
  • Lower termites need symbiotic microbes for cellulose digestion. Elizabethkingia miricola strain BM10 has been proposed as a symbiotic microbe that assists in low-temperature digestion and metabolism of Reticulitermes speratus KMT1, a termite on Bukhan Mountain, Seoul, Korea. In E. miricola strain BM10, β-glucosidase genes expressed at 10℃ were identified, and the psychrophilic enzymatic characteristic was confirmed by heterogeneously expressed proteins. Crude β-glucosidase in the culture broth of E. miricola strain BM10 showed specific enzymatic properties, and its substrate affinity was 4.69 times higher than that of Cellic CTec2. Among the genes proposed as β-glucosidase, two genes, bglB_1 and bglA_2, whose gene expression was more than doubled at 10℃ than at 30℃, were identified. They were heterogeneously expressed in Escherichia coli and identified as psychrophilic enzymes with an optimal reaction temperature of about 20℃-25℃. In this study, E. miricola strain BM10, a symbiotic bacterium of lower termites, produced psychrophilic β-glucosidases that contribute to the spread of the low-temperature habitat of a lower termite, R. speratus KMT1.

Evaluation and Categorization of Commercially Prepared Enteral Nutrition Formulas

  • Dong-Yeon Kim;Hee-Jae Suh
    • Korean Journal of Community Nutrition
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    • v.3 no.5
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    • pp.729-738
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    • 1998
  • In order to investigate the types of enteral nutrition formulas currently used in hospitals and evaluate and categorize the commercially prepared enteral nutrition formulas formulas available in the domestic market, we asked dietitians working in 6 hospitals in Seoul to complete the questionnaire and obtained compositional characteristics of 12 commercially prepared enteral nutrition formulas. The average proportion of patients receiving the commercially prepared enteral nutrition formulas(60.6%) was greater than that of patients receiving the in-hospital preparations(31.9%). In the group of patients receiving the in-hospital prepared formulas, the enteral feeding was mainly administered orally, whereas, in the group of patients receiving the commercially prepared formulas, tube feeding was the primary route of formula administration. In both groups, however, a greater proportion of patients received the formulas as total replacements of their meals and for the purpose of dietary supplementation. On the basis of major criteria for evaluation of the commercially prepared enteral nutrition formulas, the 6 products out of the 9 nutritionally complete products formulated for the purpose of dietary supplementation were grouped into the same category(standard protein, caloric density of 1kcal/ml, and tube/oral), so they were considered therapeutically comparable. However, the remaining 3 products were different in protein content(high protein) or route of administration(tube only). Of the 3 nutritionally complete products formulated specifically for the purpose of dietary therapy, 2 products were formulated for patients with renal disease, and the one product was formulated for diabetic patients. Therefore, the data in this study showed that the commercially prepared enteral nutriton formulas became an important part of the enteral nutrition for hospitalized patients in Korea, but the domestic market has not yet generated a wide variety of the formulas, not providing many choices for clinicians to manage the diets for their patients. The results of this study would be helpful for clinicians in choosing appropriate products for their patients, for manufactures in developing new products, and for regulatory authorities to establish the regulation for the broad group of heterogeneous products that are marketed and will be developed as medical foods. In addition, the process of maintaining the categories for evaluation of the commercially prepared enteral nutrition formulas should be dynamic because new products may not reasonably fit any of the existing categories.

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Design and Implementation of Security Policy Interpreter for heterogeneous security products (이기종 정보보호제품의 통합정책관리를 위한 인터프리터 설계 및 구현)

  • Hong Chul-eui;Park Jin-sub;Shin Young-sun;Kim Yi-gon
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.22-24
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    • 2005
  • 조직의 네트워크를 관리하기 위해 기관이나 단체에서는 다양한 보안관리 시스템을 운용하고 있다. 그러나 보안관리 시스템기능과 설정방법등이 서로 달라 외부의 공격에 대하기에는 어려움이 많다. 이한 문제점을 해결하기 위해 본 논문에서는 여러 보안관리 시스템 정책이 일관되고, 신속하게 적용될 수 있는 인터프리터를 제안한다. 안한 시스템을 네트워크 관리에 적용할 경우 관리자가 보안관리 시스템의 특별한 설정방법을 숙지하지 않고도 정책을 신속하고 일관되게 적용할 수 있어 외부의 공격으로부터 내부 네트워크를 보다 안전하게 보호할 수 있을 것이다.

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Nanocrystalline Copper Oxide(II)-Catalyzed Alkyne-Azide Cycloadditions

  • Song, Young-Jin;Yoo, Chung-Yul;Hong, Jong-Tai;Kim, Seung-Joo;Son, Seung-Uk;Jang, Hye-Young
    • Bulletin of the Korean Chemical Society
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    • v.29 no.8
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    • pp.1561-1564
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    • 2008
  • Although the use of Cu(II) salts as catalysts without reductants is limited in the cycloaddition of acetylenes with azides, the catalytic system employing average 10 nm CuO(II) nanoparticles in the absence of reductants shows good catalytic activity to form 1,4-disubstituted 1,2,3-triazoles even in wet THF as well as water. It is also noticeable that CuO(II) nanoparticle catalysts can be recycled with consistent activity. A range of alkynes and azides were subject to the optimized CuO(II) nanoparticle-catalyzed cycloaddition reaction conditions to afford the desired products in good yields.

PCR of Gut Contents for a Food Web Study of a Marine Ecosystem

  • Kim, Nack-Keun;Kim, Kyoung-Sun;Kim, Hyun-Woo
    • Fisheries and Aquatic Sciences
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    • v.10 no.4
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    • pp.179-185
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    • 2007
  • Understanding dietary habits is one of the most important factors in studying food webs and other ecological processes. Here we designed universal primers to amplify portions of the 18S and 28S rDNA sequences to examine gut contents using PCR techniques. The gut contents of sailfin sandfish (Arctoscopus japonicus) and pacific squid (Todarodes pacificus) were examined. In total, 11 families of prey were identified with 18S and 28S rDNA using the universal primers. The DNA sequence data indicated that the primer sets successfully amplified a wide spectrum of species and represented gut contents in a relatively convenient way. We found that information in the NCBI database was not yet sufficient to discriminate the species we isolated. In addition, technology for the separation of heterogeneous PCR products and better resolution and quantification protocols would help increase data accuracy.