• 제목/요약/키워드: Affinity techniques

검색결과 65건 처리시간 0.02초

피션트랙 검출기법에 의한 고체 및 액체상태 지질물질의 우라늄 정량과 그 적용성 (Determination of Uranium Concentration in Solid- and Liquid-state Geological Materials by Fission Track Registration Technique and its Applicability)

  • 신성천
    • 암석학회지
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    • 제24권2호
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    • pp.77-90
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    • 2015
  • 피션트랙 검출에 의해 고체 및 액체상태 지질물질 내 우라늄을 정밀정량하는 최적기법을 제안하고 그 적용성을 검증하였다. 우라늄 정량은 중성자 조사에 의해 유도시킨 $^{235}U$의 핵분열 흔적을 트랙 디텍터에 기록하여 고배율 현미경 하에서 계수함으로써 이루어진다. 우라늄-친화력이 좋은 암석(예: 화강암, 석탄)을 분말 펠릿시료로 만들어 건식 검출하면, 그다지 높지 않은 우라늄함량(<5 ppm, 즉 ${\mu}g\;g^{-1}$)에서도 빈번하게 함유된 함-우라늄광물에 기인한 트랙 군집현상으로 인해 시료의 전체평균 함량 결정이 쉽지 않았으며, 트랙 균질부와 군집부를 별도로 검토해야 한다. 시료의 균질성이 유지된다면 백운모-Lexan 디텍터에 의한 중복 측정과 여러 차례 중성자 조사에 의한 반복 측정에서 높은 재현성이 확인되었다. 건고 액체시료 경우에 $10^1ppm$ 수준 및 그 이상의 우라늄함량에서 흔히 나타나는 불균질 현상을 극복하기 위해, 진공 석영튜브를 이용한 습식 검출법을 제안한다. 습식 검출에서 우라늄 균질성은 $10^0ppm$ 수준 이하에서 회복되며, 측정하한은 $10^2ppb$ (i.e. $ng\;g^{-1}$) 수준까지 무난한 것으로 입증되었다.

비점오염 저감시설에 적용되는 여재의 흡착 및 탈착 능력 평가 (Evaluation on the adsorption and desorption capabilities of filter media applied to the nonpoint source pollutant management facilities)

  • 문소연;홍정선;최지연;유기경;김이형
    • 한국습지학회지
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    • 제17권3호
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    • pp.228-236
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    • 2015
  • 도시화는 불투수면의 증가를 초래하여 자연적인 물순환 시스템의 왜곡, 비점오염물질 유출 증가, 하천의 수질악화 및 수생태계 훼손 등의 문제를 발생시킨다. 불투수면 증가로 인한 수리수문학적, 생태학적 및 환경적 영향을 저감하기 위하여 선진국에서는 저영향개발(Low Impact Development, LID)기법을 주요한 대안으로 적용하고 있다. 국내에서도 2012년에 비점오염원관리종합대책을 통하여 LID 기법을 비점오염 관리의 주요 방안으로 추진하고 있다. LID 시설은 물순환 구축을 통한 강우유출수의 유출저감과 함께 식물, 미생물, 여재에서의 다양한 물리화학적 및 생물학적 기작을 이용하여 오염물질을 제거하는 기술이다. 이러한 LID 시설에는 다양한 여재가 사용되고 있으나 여재의 오염물질 저감능력 평가를 위한 흡착과 탈착 특성 등에 대한 종합적인 비교평가가 수행되지 못하고 있다. 따라서, 본 연구에서는 LID 시설에 사용되는 다양한 여재 중에서 모래, 자갈, 바이오세라믹, 우드칩 및 바텀애쉬에 대하여 중금속(Pb, Cu)에 대한 흡착 및 탈착 특성 분석을 통해 여재의 환경성 평가를 수행하였다. 분석결과, 연구에 사용된 모든 여재에서 Pb에 대한 흡착 선호도가 Cu에 비하여 높게 나타났으며 흡착 kinetic 모델에서는 Pseudo second order equation의 적용성이 높게 평가되었고, 흡착등온식 모델에서는 Langmuir-3 isotherm이 높은 적용성을 보였다. 특히 여재 중에서 바이오 세라믹과 우드칩의 경우 Pb에 대한 뛰어난 흡착능을 보이는 것으로 평가되었다. 여재의 탈착 실험 결과 모든 여재에서 환경부 유해물질 기준에 초과하지 않아 LID시설에 다양하게 적용 가능한 것으로 나타났다.

주제목록을 위한 한국용어열색인 시스템의 기능 (Function of the Korean String Indexing System for the Subject Catalog)

  • 윤구호
    • 한국문헌정보학회지
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    • 제15권
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    • pp.225-266
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    • 1988
  • Various theories and techniques for the subject catalog have been developed since Charles Ammi Cutter first tried to formulate rules for the construction of subject headings in 1876. However, they do not seem to be appropriate to Korean language because the syntax and semantics of Korean language are different from those of English and other European languages. This study therefore attempts to develop a new Korean subject indexing system, namely Korean String Indexing System(KOSIS), in order to increase the use of subject catalogs. For this purpose, advantages and disadvantages between the classed subject catalog nd the alphabetical subject catalog, which are typical subject ca-alogs in libraries, are investigated, and most of remarkable subject indexing systems, in particular the PRECIS developed by the British National Bibliography, are reviewed and analysed. KOSIS is a string indexing based on purely the syntax and semantics of Korean language, even though considerable principles of PRECIS are applied to it. The outlines of KOSIS are as follows: 1) KOSIS is based on the fundamentals of natural language and an ingenious conjunction of human indexing skills and computer capabilities. 2) KOSIS is. 3 string indexing based on the 'principle of context-dependency.' A string of terms organized accoding to his principle shows remarkable affinity with certain patterns of words in ordinary discourse. From that point onward, natural language rather than classificatory terms become the basic model for indexing schemes. 3) KOSIS uses 24 role operators. One or more operators should be allocated to the index string, which is organized manually by the indexer's intellectual work, in order to establish the most explicit syntactic relationship of index terms. 4) Traditionally, a single -line entry format is used in which a subject heading or index entry is presented as a single sequence of words, consisting of the entry terms, plus, in some cases, an extra qualifying term or phrase. But KOSIS employs a two-line entry format which contains three basic positions for the production of index entries. The 'lead' serves as the user's access point, the 'display' contains those terms which are themselves context dependent on the lead, 'qualifier' sets the lead term into its wider context. 5) Each of the KOSIS entries is co-extensive with the initial subject statement prepared by the indexer, since it displays all the subject specificities. Compound terms are always presented in their natural language order. Inverted headings are not produced in KOSIS. Consequently, the precision ratio of information retrieval can be increased. 6) KOSIS uses 5 relational codes for the system of references among semantically related terms. Semantically related terms are handled by a different set of routines, leading to the production of 'See' and 'See also' references. 7) KOSIS was riginally developed for a classified catalog system which requires a subject index, that is an index -which 'trans-lates' subject index, that is, an index which 'translates' subjects expressed in natural language into the appropriate classification numbers. However, KOSIS can also be us d for a dictionary catalog system. Accordingly, KOSIS strings can be manipulated to produce either appropriate subject indexes for a classified catalog system, or acceptable subject headings for a dictionary catalog system. 8) KOSIS is able to maintain a constistency of index entries and cross references by means of a routine identification of the established index strings and reference system. For this purpose, an individual Subject Indicator Number and Reference Indicator Number is allocated to each new index strings and new index terms, respectively. can produce all the index entries, cross references, and authority cards by means of either manual or mechanical methods. Thus, detailed algorithms for the machine-production of various outputs are provided for the institutions which can use computer facilities.

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Imaging Neuroreceptors in the Living Human Brain

  • Wagner Jr Henry N.;Dannals Robert F.;Frost J. James;Wong Dean F.;Ravert Hayden T.;Wilson Alan A.;Links Jonathan M.;Burns H. Donald;Kuhar Michael J.;Snyder Solomon H.
    • 대한핵의학회지
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    • 제18권2호
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    • pp.17-23
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    • 1984
  • For nearly a century it has been known that chemical activity accompanies mental activity, but only recently has it been possible to begin to examine its exact nature. Positron-emitting radioactive tracers have made it possible to study the chemistry of the human mind in health and disease, using chiefly cyclotron-produced radionuclides, carbon-11, fluorine-18 and oxygen-15. It is now well established that measurable increases in regional cerebral blood flow, glucose and oxygen metabolism accompany the mental functions of perception, cognition, emotion and motion. On May 25, 1983 the first imaging of a neuroreceptor in the human brain was accomplished with carbon-11 methyl spiperone, a ligand that binds preferentially to dopamine-2 receptors, 80% of which are located in the caudate nucleus and putamen. Quantitative imaging of serotonin-2, opiate, benzodiazapine and muscarinic cholinergic receptors has subsequently been accomplished. In studies of normal men and women, it has been found that dopamine and serotonin receptor activity decreases dramatically with age, such a decrease being more pronounced in men than in women and greater in the case of dopamine receptors than serotonin-2 receptors. Preliminary studies in patients with neuropsychiatric disorders suggests that dopamine-2 receptor activity is diminished in the caudate nucleus of patients with Huntington's disease. Positron tomography permits quantitative assay of picomolar quantities of neuro-receptors within the living human brain. Studies of patients with Parkinson's disease, Alzheimer's disease, depression, anxiety, schizophrenia, acute and chronic pain states and drug addiction are now in progress. The growth of any scientific field is based on a paradigm or set of ideas that the community of scientists accepts. The unifying principle of nuclear medicine is the tracer principle applied to the study of human disease. Nineteen hundred and sixty-three was a landmark year in which technetium-99m and the Anger camera combined to move the field from its latent stage into a second stage characterized by exponential growth within the framework of the paradigm. The third stage, characterized by gradually declining growth, began in 1973. Faced with competing advances, such as computed tomography and ultrasonography, proponents and participants in the field of nuclear medicine began to search for greener pastures or to pursue narrow sub-specialties. Research became characterized by refinements of existing techniques. In 1983 nuclear medicine experienced what could be a profound change. A new paradigm was born when it was demonstrated that, despite their extremely low chemical concentrations, in the picomolar range, it was possible to image and quantify the distribution of receptors in the human body. Thus, nuclear medicine was able to move beyond physiology into biochemistry and pharmacology. Fundamental to the science of pharmacology is the concept that many drugs and endogenous substances, such as neurotransmitters, react with specific macromolecules that mediate their pharmacologic actions. Such receptors are usually identified in the study of excised tissues, cells or cell membranes, or in autoradiographic studies in animals. The first imaging and quantification of a neuroreceptor in a living human being was performed on May 25, 1983 and reported in the September 23, 1983 issue of SCIENCE. The study involved the development and use of carbon-11 N-methyl spiperone (NMSP), a drug with a high affinity for dopamine receptors. Since then, studies of dopamine and serotonin receptors have been carried out in over 100 normal persons or patients with various neuropsychiatric disorders. Exactly one year later, the first imaging of opitate receptors in a living human being was performed [1].

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고전 서사무가를 활용한 재외동포의 문화 교육 방안 연구 - <바리공주>와 <심청전>을 중심으로 - (Cultural Education Methods for Overseas Koreans Using Classical Narratives: Focusing on Princess Bari and The Tale of Shim Cheong)

  • 강명주
    • 대순사상논총
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    • 제47집
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    • pp.173-202
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    • 2023
  • 본 연구는 재외동포 후속세대 학습자를 대상으로 고전 서사 <바리공주>와 <심청전>을 활용한 문화 교육 방안을 모색하고자 한다. 거주국에서 태생한 재외동포 후속세대 학습자의 비율이 늘어나고 있는 만큼 세대교체의 변화를 반영한 재외동포의 교육 방안이 요구되는 시점이다. 특히 재외동포 다수의 학습 동기를 고려하여 정체성 정립을 위한 문화 교육 방안을 제언하고자 하였다. 교육 자료로는 고전 서사<바리공주>와 <심청전>을 텍스트로 삼았다. 두 텍스트에 나타나는 통과의례적 구조가 주인공의 '존재론적 위치의 변화'를 보여준다는 점에서 정체성 교육에 유의미할 것으로 보았기 때문이다. 바리와 심청은 가부장적 세계에서 부유하던 여성 주체다. 그들이 부모와의 관계로 이루어진 세계에서 벗어나는 탈영토화의 과정을 거쳐 새로운 관계를 통해 스스로를 재정립하는 서사를 거주국의 질서에서 부유하는 재외동포가 가체험해 봄으로써 정체성을 성찰할 수 있도록 하였다. 인간의 본래적 자아를 긍정하는 작품 서사에 자기 서사를 합치함으로써 '나'를 구성하는 것들을 긍정할 수 있도록 인식의 변화를 유도할 수 있기 때문이다. 궁극적으로는 고전 작품 서사에 대한 심층적 이해와 작품서사 주체와의 일체감을 통해 자기 서사를 진단하고 혼종적 '주체'의 긍정성을 확보하는 방향으로 교육 방안을 제언하고자 하였다. 이는 자연스럽게 모국에 대한 문화에도 관심과 유대감을 높일 수 있는 계기가 될 수 있을 것이다.