• 제목/요약/키워드: Natural source

검색결과 2,091건 처리시간 0.028초

Cited-by Linking 데이터 기반 자연과학 및 공학 분야 학술논문 인용 패턴 분석 (Citing Pattern Analysis based on Cited-by Linking Data of DOI Journals in the Field of Natural Sciences & Engineering)

  • 서선경;최호남;김병규;최선희;김정환
    • 정보관리학회지
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    • 제33권2호
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    • pp.157-176
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    • 2016
  • Cited-by Linking 서비스는 CrossRef에서 제공하는 주요 서비스 중 하나로 해당 논문이 DOI를 통하여 얼마나 인용되었는지 누적하여 집계된 데이터이다. 이에 본 연구에서는 KISTI의 학술정보통합관리시스템에서 월단위로 구축 관리하는 Cited-by Linking 데이터를 분석하여 자연과학과 공학 분야의 인용 패턴을 규명하고자 하였다. 이를 위해서 전체 기탁된 21만 건 중 자연과학과 공학 분야 총 170,999건(315종)을 분석 대상으로 하고, 2016년 3월까지 누적된 Cited-by Linking 데이터를 수집하였다. 연구의 분석 결과, 첫째, 글로벌하게 인용될 가능성에서 사용 언어는 영향을 미치고 있으며, 둘째, SCIE 및 SCOPUS 등재 여부 역시 인용가능성에 상당 부분 기여하고 있음을 확인하였다. 셋째, 자연과학 분야는 거의 동일한 주제 분야에서 인용을 받고 있으며, 상대적으로 공학 분야는 타주제 분야에서 더 인용 받고 있음을 파악하였다. 이러한 연구의 결과는 자연과학과 공학 분야의 세부주제 분야별 인용 행태를 규명하고, 향후, 인용 행태에 관한 연구에서 유용하게 활용될 것으로 기대한다.

Characteristic Features of Cytotoxic Activity of Flavonoids on Human Cervical Cancer Cells

  • Sak, Katrin
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권19호
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    • pp.8007-8018
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    • 2014
  • Cervical cancer is the most common gynecologic malignancy worldwide and development of new therapeutic strategies and anticancer agents is an urgent priority. Plants have remained an important source in the search for novel cytotoxic compounds and several polyphenolic flavonoids possess antitumor properties. In this review article, data about potential anticarcinogenic activity of common natural flavonoids on various human cervical cancer cell lines are compiled and analyzed showing perspectives for the use of these secondary metabolites in the treatment of cervical carcinoma as well as in the development of novel chemotherapeutic drugs. Such anticancer effects of flavonoids seem to differentially depend on the cellular type and origin of cervical carcinoma creating possibilities for specific targeting in the future. Besides the cytotoxic activity per se, several flavonoids can also contribute to the increase in efficacy of conventional therapies rendering tumor cells more sensitive to standard chemotherapeutics and irradiation. Although the current knowledge is still rather scarce and further studies are certainly needed, it is clear that natural flavonoids may have a great potential to benefit cervical cancer patients.

Production of pullulan by Aureobasidium pullulans HP-2001 with continuous culture

  • 서형필;이유정;김성구;신명교;이진우
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.253-256
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    • 2003
  • In batch culture of A. pullulans HP-2001, maximal production of pullulan was 57.90 g/l at 96 hr. The maximal production of pullulan with 76.55 g/l occurred when substituted solution was 10% (w/v) sucrose, 0.25% (w/v) yeast extract and mineral salts. The maximal production of pullulan was 75.00 g/l with a dilution rate of $0.015\;h^{-1}$. Productivity of pullulan in the continuous culture fed with the fresh medium was higher than that fed with the fresh medium without nitrogen source.

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Biodegradation of Hydrocarbons by an Organic Solvent-Tolerant Fungus, Cladosporium resinae NK-1

  • Oh, Ki-Bong;Mar, Woong-Chon;Chang, Il-Moo
    • Journal of Microbiology and Biotechnology
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    • 제11권1호
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    • pp.56-60
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    • 2001
  • A kerosene fungus of Cladosporium resinae NK-1 was examined for its ability to degrade individual n-alkanes and aromatic hydrocarbons by gas chromatography-mass spectrometry, and its organic solvent-tolerance was investigated by making use of the water-organic solvent suspension culture method. It grew on a wide range of solvents of varying hydrophobicities and it was found to have tolerance to various kinds of toxic organic solvents (10%, v/v) such as n-alkanes, cyclohexane, xylene, styrene, and toluene. A hydrocarbon degradation experiment indicated that NK-1 had a greater n-alkane degrading ability compared to that of the other selected strains. C. resinae NK-1, which could utilize 8-16 carbon chain-length n-alkanes of medium chain-length as a carbon source, could not assimilate the shorter chain-length n-alkanes and aromatic hydrocarbons tested so far. The n-alkane degrading enzyme activity was found in the mycelial extract of the organism.

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환경음에 대한 계층별 인식 차이에 관한 조사 연구 (The Study on Cognition Difference of Environmental Sounds due to Subject' Classes)

  • 신훈;백건종;송민정;장길수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1187-1190
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    • 2007
  • This study aims to induce acoustic environmental characteristics which could be used for soundscape design by carrying out factor analysis on sound source image and cognition analysis on subjects' responses on selective questions due to class differences. The results of this study are as follows ; Satisfaction rate differences on exterior acoustic environment due to sensitivity and residence year were revealed. After factor analysis of living sound sources' image, it is known that natural sound, traditional sound, socials traffic sound, rural sound, religious sound and the others are main factors. Social traffic sound is the most one that should be eliminated and traditional sound is selected as a most Korean-like sound. Natural sound is evaluated as the most one that should be preserved and the most retrospectively one.

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몰드변압기 소음저감을 위한 진동특성 파악 (The vibration characteristics for noise reduction of mold transformer)

  • 김기원;김양한
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.49-53
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    • 2008
  • This study deals a way to reduce the transformer noises. The first step is to identify the source of the transformer noises. The second step is obtaining the vibration characteristics of transformer; its natural frequencies and mode shapes. Based on these information, an method to reduce the vibration of transformer can be found. The cause of transformer noises is mainly due to the magnetostrictive vibration of a core which is made of ferromagnetic substances. It is well known that the magnetostrictive vibration of a core is unavoidable, and a way to reduce the transformer noise by structural design is needed. It requires understanding the vibration characteristics. The natural frequencies and the mode shapes of transformer are analyzed by performing the modal testing.

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CNG Dual Fuel 디젤기관의 성능과 배출가스 개선을 위한 수소혼합 실험 (Experimental Study to Improve the Performance and Emission of CNG Dual Fuel Diesel Engine Mixed with Hydrogen)

  • 김복석
    • 에너지공학
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    • 제9권2호
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    • pp.83-88
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    • 2000
  • In this study, the performance and pollutant emission of CNG engine using diesel oil as a source of ignition, so called CNG dual fuel diesel engine is considered by experiment. One of the unsolved problems of the natural gas dual fuel engine is that there is too much exhaust of total hydrocarbon (THC) at a low equivalent mixture ratio. To fix it, a natural gas mixed with hydrogen was applied to engine test. The results showed that the higher the mixture ratio of hydrogen to natural gas, the higher the combustion efficiency. and when the amount of the intake air is reached to 90% of WOT, the combustion efficiency was promoted. But, like a case making the injection timing earlier, the equivalent mixture ratio for the knocking limit decrease and the produce of NOx increases.

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화학증착용 천연가스버너 개발 (Development of the Natural Gas Burner for Modified Chemical Deposition Processes)

  • 유현석;이중성;한정옥;최동수
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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    • pp.75-81
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    • 2001
  • MCVD(modified chemical vapor deposition) used in making optical-fiber currently utilizes the hydrogen-oxygen burner as a energy supply source. To improve the productivity and to reduce the manufacturing cost of optical-fiber, a natural gas-oxygen burner has been developed. The manufacturing processes of optical-fiber consist of vapor deposition, collapse and drawing processes. Among these processes, the vapor deposition and the collapse processes are important in terms of improving the productivity and saving the production cost. The vapor deposition and collapse processes are performed by combustion heat and flame force supplied by a burner. So the flame force of the burner used in these processes is required to have an optimal and consistent value in order to allow uniform heating and collapse of quartz tube. In this regard, the momentum ratio of natural gas and oxygen has been optimally determined by modification of a burner and the inlet flow pass also has been modified.

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Natural Organic Matter Removal and Fouling Control in Low-Pressure Membrane Filtration for Water Treatment

  • Cui, Xiaojun;Choo, Kwang-Ho
    • Environmental Engineering Research
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    • 제19권1호
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    • pp.1-8
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    • 2014
  • Natural organic matter (NOM) is a primary component of fouling in low-pressure membrane filtration, either solely, or in concert with colloidal particles. Various preventive measures to interfere with NOM fouling have been developed and extensively tested, such as coagulation, oxidation, ion exchange, carbon adsorption, and mineral oxide adsorption. Therefore, this article aims to conduct a literature review covering the topics of low-pressure membrane processes, NOM characteristics and fouling behaviors, and diverse fouling control strategies. In-depth explanations and discussion are made regarding why some treatment options are able to remove NOM from source water, but do not reduce fouling. This review provides insight for hybridized membrane processes with respect to NOM removal and fouling mitigation in water treatment.

자연저감 모델링 연구 (Evaluation of Natural Attenuation of Petroleum Hydrocarbons in a Shallow Sand Aquifer: a Modeling Study)

  • 이진용;이명재;이강근;이민효;윤정기
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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    • pp.128-131
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    • 2001
  • We evaluated natural attenuation of petroleum hydrocarbons in a shallow aquifer using a modeling study. The studied shallow aquifer was severely contaminated with petroleum hydrocarbons, especially toluene, ethylbenzene and xylenes (i.e, TEX). The exact spill history was not known. Therefor we used a contaminant level in May 1999 (the first sampling date of our integrated study) as an initial contaminant concentration. we calibrated required transport parameters using the contamination levels obtained from groundwater analyses in September of 1999. For fate and transport of the petroleum contaminants, five case 2 with sorption and degradation. case 3 with sorption and degradation (half decay constant compared with case 2), case 4 with degradation but no sorption, and case 5 with sorption but no degradation. For sorption and degradation, a linear sorption isotherm and first order irreversible decay was assumed, respectively and no additional contamination source to groundwater is also assumed.

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