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국립백두대간 수목원의 터핀(terpene)류의 발생특성 (Terpene Emissions from BackDooDaeGan Forest)

  • 이해근;백하주;김정진;김영훈
    • 한국환경과학회지
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    • 제31권12호
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    • pp.1039-1050
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    • 2022
  • Forests are valuable natural resources for people living around the mountains. In particular, the comfortable feeling or healing is one of the most important benefits obtained from forests. This healing can be possible by many aspects of forests, including the landscape, natural sounds, anions, and pleasant aromas. We focused on the volatile organics from forest causing pleasant aromas, phytoncides. Twenty phytoncides were monitored from February to September in a national tree garden (BaekDoDaeGan SooMokWon). Five sites were monitored two times per month and 20 phytoncides were detected. Borneol showed the highest annual average concentration and the order of concentration was borneol > mycene > sabinene > limonene > α-pinene. The average phytoncide concentration was relatively high in spring and summer season when the trees were physiologically active. Daily monitoring showed that the afternoon hours had higher concentrations of phytoncides than the morning hours, which may be due to the stabilized atmospheric conditions at the sites. Among the five sites, coniferous forests gave higher phytoncide emissions than broadleaf tree forests. The current study showed that forests produce several phytoncides that cause a healing effect and a forest bath may be beneficial to the health of visitors to forests.

도시안전맵 웹사이트 구축을 위한 기존 웹사이트 분석연구 (Research for Building an Existing Web Site to Web Site Analysis of Urban Safety Map)

  • 임동현;김현수;김진욱;강부성
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2008년 추계학술발표대회 논문집
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    • pp.222-225
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    • 2008
  • In urban life, an interest in safety and demands for safety information about crimes and traffic are increasing. As well, communication on the internet is so active. In this study, we analyze web sites in US, UK, and JP, which have started safety map services, and then we provide basic material for the introduction of safety map into Korea. According to the analysis result, in US and UK, the safety map web sites are administered by the government and provided to the general public. The geographical area is provided around administrative districts and statistical data. In JP, The safety map web site provide not a one sided service but the service that user can directly take a part in, and also there is an web site for crimes against vulnerable people.

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항우울제와 연관약물의 약물상호작용 (Antidepressants and Related Drug Interactions)

  • 이민수
    • 생물정신의학
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    • 제7권1호
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    • pp.21-33
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    • 2000
  • As the clinical practice of using more than one drug at a time increase, the clinician is faced with ever-increasing number of potential drug interactions. Although many interactions have little clinical significances, some may interfere with treatment or even be life-threatening. This review provides a better understanding of drug-drug interactions often encountered in pharmacotherapy of depression. Drug interactions can be grouped into two principal subdivisions : pharmacokinetic and pharmacodynamic. These subgroups serve to focus attention on possible sites of interaction as a drug moves from the site of administration and absorption to its site of action. Pharmacokinetic processes are those that include transport to and from the receptor site and consist of absorption, distribution on body tissue, plasma protein binding, metabolism, and excretion. Pharmacodynamic interactions occur at biologically active sites. In this review, emphasis is placed on antidepressant medications, how they are metabolized by the P450 system, and how they alter the metabolism of other drugs. When prescribing antidepressant medications, the clinician must consider the drug-drug interactions that are potentially problematic.

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Partial Characterization of Soybean cDNA Encoding CTP: Phosphocholine Cytidylyltransferase

  • Sung Ho Cho
    • Journal of Plant Biology
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    • 제38권4호
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    • pp.359-364
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    • 1995
  • As the first step to elucidate the relationship between the structure and function of CTP:phosphocholine cytidylyltransferase (EC 2.7.7.15) in plants, the partial nucleotide sequence of soybean cytidylyltransferase cDNA was determined using a polymerase chain reaction (PCR). Degenerate oligonucleotide primers were synthesized from the conserved region revealed from the rat and yeast cytidylyltransferase DNA sequences. The catalytic domain region showed 78 and 76% homology with the rat and yeast amino acid sequences, respectivly. The hydropathy profile indicated that the C-terminal non-catalytic portion of the protein was very hydrophilic, and in the region between the catalytic domain and the C-terminal region, there was a large amphipathic $\alpha$-helical domain that was believed to bind the membrane surface in the active formation. There are 7 potential sites for phosphorylation by protein kinase C and 4 potential sites for phosphorylation by Ca2+/calmodulin kinase within the determined sequence.

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Improvement of Glyphosate Resistance through Concurrent Mutations in Three Amino Acids of the Pantoea sp. 5-Enolpyruvylshikimate-3-Phosphate Synthase

  • Liu, Feng;Cao, Yueping
    • Journal of Microbiology and Biotechnology
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    • 제28권8호
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    • pp.1384-1390
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    • 2018
  • Glyphosate inhibits the target enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway. A mutant of EPSPS from Pantoea sp. was identified using site-directed mutagenesis. The mutant showed significantly improved glyphosate resistance. The mutant had mutations in three amino acids: Gly97 to Ala, Thr 98 to Ile, and Pro 102 to Ser. These mutation sites in Escherichia coli have been studied as significant active sites of glyphosate resistance. However, in our research, they were found to jointly contribute to the improvement of glyphosate tolerance. In addition, the level of glyphosate tolerance in transgenic Arabidopsis confirmed the potentiality of the mutant in breeding glyphosate-resistant plants.

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.

Micro-droplet cell을 이용한 Fe-17Cr 합금의 공식 발생에 대한 연구 (A Study on the Initiation of Pitting Corrosion of Fe-17Cr Alloy Using Micro-Droplet Cell Technique)

  • 김재중;이재봉
    • 대한금속재료학회지
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    • 제46권12호
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    • pp.809-816
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    • 2008
  • The influences of various parameters such as inclusions, surface roughness, exposed areas and chloride ion concentrations on the initiation of pitting of Fe-17Cr alloy were investigated, using micro-droplet cell technique. Micro-droplet cell allows one to align the micro-electrode to the desired spot of the working electrode and measure directly local currents with the potentiodynamic polarization. Micro electrochemical tests were carried out at the inclusions after EDX analysis of inclusion. EDX analysis identified inclusions as Cr-oxides. It was found that some active inclusions among Cr-oxide inclusions acted as initiation sites for pitting corrosion. In addition, the rougher surface and the denser chloride ion concentration offered easier pit initiation sites, causing the more susceptible to pitting corrosion.

Vapor-Phase Chlorination of Chlorobenzene over Solid-Acid Catalysts

  • 장향자;최평호;박상언
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.507-511
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    • 1995
  • Catalytic chlorination of chlorobenzene was studied in vapor phase using various solid-acid catalysts such as silica-alumina, alumina, zeolite and a modified clay prepared by impregnating bentonite with ferric chloride. The conversions of both chlorine gas and chlorobenzene showed high over silica-alumina, alumina and modified clay catalysts. However relatively large amounts of polychlorinated benzene derivatives were also observed. The active species of catalytic activity in chlorination of chlorobenzene in vapor phase were proved to be as Lewis acid sites by in-situ IR experiments. The strength of Lewis acid sites which were effective for the vapor-phase chlorination seemed to be having Hammett acidity Ho >-3.0. The selectivity to dichlorobenzenes was proved to be high over the zeolite catalyst due to their shape-selective properties. p-Dichlorobenzene or dichlorobenzene selectivities were improved more or less by changing the reaction conditions.

Important Parameters Related With Fault for Site Investigation of HLW Geological Disposal

  • Jin, Kwangmin;Kihm, You Hong;Seo, Dong-Ik;Kim, Young-Seog
    • 방사성폐기물학회지
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    • 제19권4호
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    • pp.533-546
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    • 2021
  • Large earthquakes with (MW > ~ 6) result in ground shaking, surface ruptures, and permanent deformation with displacement. The earthquakes would damage important facilities and infrastructure such as large industrial establishments, nuclear power plants, and waste disposal sites. In particular, earthquake ruptures associated with large earthquakes can affect geological and engineered barriers such as deep geological repositories that are used for storing hazardous radioactive wastes. Earthquake-driven faults and surface ruptures exhibit various fault zone structural characteristics such as direction of earthquake propagation and rupture and asymmetric displacement patterns. Therefore, estimating the respect distances and hazardous areas has been challenging. We propose that considering multiple parameters, such as fault types, distribution, scale, activity, linkage patterns, damage zones, and respect distances, enable accurate identification of the sites for deep geological repositories and important facilities. This information would enable earthquake hazard assessment and lower earthquake-resulted hazards in potential earthquake-prone areas.

지속의도와 과거행위가 핵심 사용자의 지식공유 지속여부 및 빈도에 미치는 효과: 네이버 지식인 사례 (Influences of Continuance Intention and Past Behavior on Active Users' Knowledge Sharing Continuance and Frequency: Naver Knowledge-iN case)

  • 강민형
    • 지식경영연구
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    • 제21권3호
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    • pp.67-87
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    • 2020
  • 사용자가 컨텐츠의 소비자에 그치는 것이 아니라 생산자 역할까지 담당하는 웹 2.0 시대에는 사용자의 지속적 컨텐츠 생산이 온라인 사이트의 성공에 핵심 요소가 된다. 온라인 Q&A 사이트는 웹 2.0 트렌드의 대표적 사례로, 고품질의 지식을 반복적으로 공유하는 핵심 사용자들이 지속적으로 지식을 공유하도록 하는 것이 사이트의 성패를 결정짓는다. 본 연구는 핵심 사용자의 지식공유 지속행위를 유발하는 두가지 경로, 즉 지속의도로 대표되는 정교한 의사결정 과정(elaborate decision process)와 과거행위로 대표되는 자동화된 인지적 과정(automated cognitive process)을 제안하였다. 네이버 지식인의 핵심 사용자 337인의 주관적 의도 데이터와 객관적 온라인 행동 데이터를 수집한 뒤, 지속의도와 과거행위의 직접효과 및 둘 간의 조절효과를 검증해 보았다. 종속변수로 이전 연구에서 주로 사용되었던 지식공유 빈도를 측정하는 것과 더불어, 특정 기간 이상 답변활동이 없을 경우 지식공유를 중단한 것으로 판단하는 지식공유 지속여부를 측정하였다. 콕스비례위험 회귀분석과 음이항 회귀분석을 사용하여 지속의도와 과거행위가 지속행위의 두가지 유형에 미치는 효과를 살펴본 결과, 지식공유 지속여부에는 과거행위만 유의한 영향력을 보였으며, 지식공유 빈도에는 지속의도와 과거행위 모두 유의한 영향력을 보였다. 또한, 과거행위가 지속의도의 지식공유 빈도에 대한 영향력을 부정적으로 조절하는 것까지 확인할 수 있었다. 온라인 Q&A 사이트에서 핵심 사용자들의 지식공유 행위를 지속시키기 위해서는 꾸준한 지식공유를 통해 습관화 과정을 거치는 것이 중요하며, 지식공유 빈도를 높이고자 할 경우에는 습관화와 더불어 지식공유 지속의도를 높일 수 있는 적절한 혜택의 마련이 필요하다.