• Title/Summary/Keyword: SK2

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Oxidation of 2,6-Dimethylnaphthalene by Co-Mn-Br Based Homogeneous Catalyst (Co-Mn-Br계 균일촉매를 이용한 2,6-Dimethylnaphthalene의 산화반응)

  • Kim, Dong-Bum;Park, Seungdoo;Cha, Woonou;Roh, Hang-Duk;Kwak, Kyu Dae
    • Applied Chemistry for Engineering
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    • v.10 no.6
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    • pp.863-870
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    • 1999
  • The catalytic performance of Co-Mn-Br system was performed in the 2,6-dimethylnaphthalene(DMN) oxidation at relatively mild reaction conditions such as $160^{\circ}C$ and $6kg/cm^2$. Experiments were conducted using a $2{\ell}$ batch reactor with varying the concentrations of catalysts. The reaction route of DMN oxidation was considered by measuring the concentration of intermediate species. As the intermediate species, 2-formyl-6-naphthoic acid, 2-methyl-6-naphthoic acid and 2-hydroxymethyl-6-methylnaphthalene are found. It was found that the yield of 2,6-naphthalene dicarboxylic acid(NDA) is largely dependent on the Co and Br concentrations. In addition, it was observed that color-b was closely related with Mn concentration in this experimental range. The burning loss of solvent could be reduced by controlling the concentration of Mn and Br. Addition of small amount of Ce and Cu compounds led to increase the NDA yields and decrease the burning amount of solvent.

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Mobile Home Network Service (모바일 홈 네트워크 서비스)

  • Shin Yong-Sik;Lee Jung-Su;Park Yong-Gil;Jung Won-Suk
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.329-331
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    • 2003
  • 본 논문에서는 통합 및 유비퀴터스(Ubiquitous) 환경의 실현을 위한 첫 단계 서비스라 할 수 있는 모발일 홈 네트워크 서비스에 대해 살펴본다. 따라서 모바일 홈 네트워크(mobile Home Network, mHN) 서비스의 개념 및 이를 제공하기 위해 존재하는 가치사슬, 서비스 모델 및 필요기술 등을 제시한다. 본 논문에서는 서비스 모델을 크게 P2P, Semi P2P, 통합형 (Hub & Spoke)으로 구분하여 각 모델의 특징을 살펴본다. 특히, 통합형 모델을 위한 서버의 서비스, 제어 및 관리 기능과 관련 노드들과의 연동을 위한 인터페이스 등을 나타낸다. 뿐만 아니라 댁내와 댁내의 연결 노드인 홈 게이트웨이의 구조 및 기능 들을 살펴보고 마지막으로 다양한 모바일 홈 네트워크 서비스의 예를 제시한다.

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적대적 M&A에 대한 방어(1)

  • Eom, Jae-Min
    • Venture DIGEST
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    • s.103
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    • pp.26-27
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    • 2007
  • 최근 이른바 '장하성 펀드'가 대한화섬 지분을 매집한 후 경영진에 지배구조개선을 요구하면서 주식시장에서 대한화섬의 주가는 상승세를 계속했다. 또한 지난 해 초순에는 세계적인 '기업사냥꾼' 칼 아이칸(Carl Icahn)이 KT&G 지분을 매집하면서 사회적 관심을 모으기도 했다. 무엇보다도, 국민들에게서 적대적 M&A에 대한 인식을 각인시킨 계기는 2003년 3월 소버린 펀드가 분식회계 파장을 계기로 주가가 급락한 (주)SK 주식을 매입하면서부터일 것이다. 당시 소버린 펀드는 불과 2개월만에 (주)SK 주식 14.99%를 매입하였고 우호지분을 규합하여 당시 최태원 회장의 교체를 시도하겠다고 선언하였다. 종국적으로 주주총회에서의 의결권 대결은 당시 (주)SK의 승리로 끝났지만, 그 기간 동안 (주)SK 주가는 고공행진을 계속하였고, 소버린 펀드는 2005년 7월 무려 8,000억 원의 주식 양도차익을 남기고 유유히 시장을 떠났다. 이번 호와 다음 호에서는 2회에 걸쳐 이와 같이 뜨거운 사회적 관심을 모으고 있는 적대적 M&A에 대해 살펴 보고, 이에 대한 방어 방법을 검토해 보고자 한다.

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Analysis of Hydrogen Production Cost by Production Method for Comparing with Economics of Nuclear Hydrogen (원자력 수소 경제성 비교를 위한 수소 생산 방법별 생산단가 분석)

  • Lim, Mee-Sook;Bang, Jin-Hwan;Yoon, Young-Seek
    • Transactions of the Korean hydrogen and new energy society
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    • v.17 no.2
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    • pp.218-226
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    • 2006
  • It can be obtained from hydrocarbon and water, specially production of hydrogen from natural gas is most commercial and economical process among the hydrogen production methods, and has been used widely. However, conventional hydrogen production methods are dependent on fossil fuel such as natural gas and coal, and it may be faced with problems such as exhaustion of fossil fuels, production of greenhouse gas and increase of feedstock price. Thermochemical hydrogen production by nuclear energy has potential to efficiently produce large quantities of hydrogen without producing greenhouse gases. However, nuclear hydrogen must be economical comparing with conventional hydrogen production method. Therefore, hydrogen production cost was analyzed and estimated for nuclear hydrogen as well as conventional hydrogen production such as natural gas reforming and coal gasification in various range.

Complete genome sequence of Lactobacillus plantarum SK151 isolated from kimchi (김치로부터 분리한 Lactobacillus plantarum SK151의 유전체 염기서열 해독)

  • Amoranto, Mia Beatriz C.;Oh, Ju Kyoung;Bagon, Bernadette B.;Hwang, In-Chan;Kim, Sang Hoon;Cho, Chun-Sung;Kang, Dae-Kyung
    • Korean Journal of Microbiology
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    • v.54 no.3
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    • pp.295-298
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    • 2018
  • Lactobacillus plantarum is a Gram-positive, facultative heterofermentative, nonspore-forming nonmotile bacterium found in a wide range of environmental niches. Here we present the complete genome sequence of L. plantarum SK151 isolated from kimchi, which shows high adhesion to intestinal epithelial cells. The genome is 3,231,249 bp in length and has a GC content of 44.6%. The genome contains genes related to cell adhesion and a complete operon for riboflavin biosynthesis.

Differential Role of protein Kinase C in Ginsenoside $Rh_2$ - induced Apoptosis in SK-N-BE(2) and C6Bu-1 Cells

  • Young Sook Kim;Sun
    • Proceedings of the Ginseng society Conference
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    • 1998.06a
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    • pp.244-252
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    • 1998
  • Ginsenoside Rh, (G-Rh,) from Panax ginseng induced morphological features of apoptosis and DNA fragmentation as a biochemical marker of apoptosis confirmed by TUNEL reaction and agarose gel electrophoresis in human neuroblastoma SK-N-BE(2) and rat glioma C6Bu-1 cells During apoptosis by G-Rh2, protein kinase C (PKC) isoforms were analysed by immunoblotting. In SK-N-BE(2) cells, the levels of a, p and ${\gamma}$ subtypes were increased by undergoing apoptosis, while PKC e isoform increased early in treatment (3 h and 6 h). In addition, PKC s isoform gradually decreased during apoptosis by G-Rh2 and PKC $\theta$ isoform was detected in neither untreated- nor G-Rh1-treated SK-N-BE(2) cells (data not shown). However, no significant changes in the level of S and s isoforms were observed in C6Bu-1 cells undergoing apoptosis by G-Rh2. These results suggest that PKC subtypes may play differential roles in apoptotic signal pathways and their roles can be cell type-specific in apoptosis induced by G-Rh2.

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Differential Expression of Protein Kinase C Subtypes during Ginsenoside Rh2-Induced Apoptosis in SK-N-BE(2) and C6Bu-1 Cells

  • Kim, Young-Sook;Jin, Sung-Ha;Lee, You-Hiu;Park, Jong-Dae;Kim, Shin-Il
    • Archives of Pharmacal Research
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    • v.23 no.5
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    • pp.518-524
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    • 2000
  • We examined the modulation of protein kinase C (PKC) subtypes during apoptosis induced by ginsenoside Rh2 (G-Rh2) in human neuroblastoma SK-N-Bl(2) and rat glioma C6Bu-1 cells. Apoptosis induced by C-Rh2 in both cell lines was confirmed, as indicated by DNA fragmentation and in situ strand breaks, and characteristic morphological changes. During apoptosis induced by G-Rh2 in SK-N-BE(2) cells, PKC subtypes $\alpha$, $\beta$ and $\gamma$ were progressively increased with prolonged treatment, whereas PKC $\delta$ increased transiently at 3 and 6 h and PKC $\varepsilon$ was gradually down-regulated after 6 h following the treatment. On the other hand, PKC subtype $\beta$ markedly increased at 24 h when maximal apoptosis was achieved. In C6Bu-l cells, no significant changes in PKC subtypes $\alpha$, $\gamma$, $\delta$, $\varepsilon$ and $\beta$ were observed during apoptosis induced by G-Rh2. These results suggest the evidence for a possible role of PKC subtype in apoptosis induced by G-Rh2 in SK-N-BE(2) cells but not in C6Bu-1 cells, and raise the possibility that G-Rh2 may induce apoptosis via different pathways interacting with or without PKC in different cell types.

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Cytotoxic and Mutagenic Effects of Cinnamomum cassia Bark-Derived Materials

  • LEE , HOI-SEON;KIM, SUN-YEOU;LEE, CHI-HOON;AHN, YOUNG-JOON
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1176-1181
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    • 2004
  • The cytotoxic activities of Cinnamomum cassia (Blume) bark-derived materials toward six human HeLa epithelioid cervix, A549 lung, SK-OV-3 ovarian, SK-MEL-2 melanoma, XF-498 central nerve system, and HCT-15 colon tumor cell lines were evaluated by using sulforhodamine B assay and compared to those of the anticancer agents, cisplatin and mitomycin C. The biologically active constituent of the Cinnamomum bark was characterized as trans­cinnamaldehyde by spectroscopic analysis. The cytotoxic activity of cinnamaldehyde against HeLa, SK-MEL-2, and HCT -15 cell lines was comparable to that of cisplatin and mitomycin C. The compound showed lower activity against A549, SK-OV-3, and XF-498 cell lines than the anticancer agents. Eugenol exhibited moderate activity against SK-OV­3, XF-498, and HCT-15 tumor cells, and trans-cinnamic acid, cinnamyl alcohol, $\alpha-pinene,\;and\;\beta-pinene$ showed little or no activity against model tumor cells. Cinnamaldehyde was not mutagenic against four strains (TA 98, TA 100, TA 1535, and TA 1537) of Salmonella typhimurium (Castel and Chalm). These results indicate at least one pharmacological action of C. cassia.

Comparison of Food and Nutrient Consumption Status between Displaced North Korean Children in South Korea and South Korean Children (한국 거주 북한이탈 어린이와 남한 어린이의 식품 및 영양소 섭취 현황 비교)

  • Lee, Soo-Kyung;Nam, So-Young
    • Korean Journal of Community Nutrition
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    • v.17 no.4
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    • pp.407-418
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    • 2012
  • Many displaced North Koreans (NK) are living in South Korea (SK); however nutrition research with the displaced NK is limited. This study examined food and nutrient consumption status of displaced NK children (6-18 year-old) currently living in SK. A total of 154 children were recruited, and a pre-tested dietary behavior questionnaire, food frequency questionnaire, 24-hr recall method were used. Sex- and age-matched SK children (n = 462) randomly selected from 2009-2010 Korea National Health and Nutrition Examination Survey were used as the comparison group. This study found that more NK children skipped breakfast (37%) and dinner (11%), and ate breakfast (38.8%) and dinner (18.2%) without family members than SK children. Many NK children reported that they rarely ate bread, rice cake, hamburger, pizza, fried food, candy. NK children consumed significantly less energy and nutrients (except calcium) and obtained more energy from fat and protein than SK children. Overall index of nutrient quality in NK children, however, was generally good. Length of stay in SK and breakfast skipping rates were significantly associated with lower diet quality. Therefore, nutrition education with displaced NK children should target those who recently came to SK. How to incorporate "new" foods, generally high in energy, sugar, or fat, in healthy ways and importance of breakfast should be emphasized. The growth patterns of the displaced NK children who were born and raised in food-deprived environments and will grow in food-affluent environments of SK should be monitored for health promotion of the NK children and for nutrition policy of the future united Korea.