• 제목/요약/키워드: Enrichment factors

검색결과 203건 처리시간 0.022초

Measurement of the Elemental Composition in Airborne Particulate Matter Using Instrumental Neutron Activation Analys

  • Chung, Yong-Sam;Lim, Jong-Myoung;Moon, Jong-Hwa;Kim, Sun-Ha;Cho, Hyun-Je;Kim, Young-Jin
    • Nuclear Engineering and Technology
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    • 제36권5호
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    • pp.450-459
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    • 2004
  • For the evaluation of emission sources by air sampling, airborne particulate matter for fine (<2.5 ${\mu}m2$ EAD : $PM_{2.5}$) and coarse partical (2.5-10 ${\mu}m2$ EAD : $PM_{2.5-10}$ fractions were collected using a Gent stacked filter unit low volume sampler and two types of polycarbonate filters. Air samples were collected twice monthly at two regions in and around Daejeon city in the Republic of Korea from January to December 2002. Monthly mass concentration of $PM_{2.5}$ and $PM_{2.5-10}$ were measured and the concentrations of 10 marker elements (Al, Sc, Ti ; Na, Cl ; As, V. Sb, Br, Se) were determined by an instrumental neutron activation analysis. Analytical quality control was corried out using certified reference materials. Enrichment factors were also calculated from the monitoring data to classify the anthropogenic and crustal origins.

뇌가소성과 뇌졸중 재활 (Brain Plasticity and Stroke Rehabilitation)

  • 김식현
    • PNF and Movement
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    • 제6권2호
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    • pp.39-50
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    • 2008
  • Purpose : This article reviewed the advances in the understanding of the effect of motor rehabilitation and brain plasticity on functional recovery after CNS damage. Methods : This is literature study with Pubmed, Medline and Science journal. Results : The inability of CNS neurons to regenerate is largely associated with nonneuronal aspects of the CNS environment. Especially, this neuronal growth inhibition is mediated by myelin associated glycoprotein, olygodendrocyte-myelin glycoprotein, and NOGO. Enriched environment, motor learning, forced limb use have been utilized in scientific studies to promote functional reorganization and brain plasticity. Especially, enriched environment and motor enrichment may prime the brain to respond more adaptively to injury, in part by expressed neurotrophic factors. Conclusions : These reviews suggest that activity-induced neural plasticity occur in damaged brain areas in order to functional reorganization, where it could contribute to motor recovery, and represent a target for stroke rehabilitation.

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학습 평가에 대한 중요도 및 수행도 분석(IPA) - 공과대학 심화프로그램의 전문교양 및 MSC 교과목을 중심으로 - (An Importance and Performance Analysis regarding Classroom Assessment - Professional General Education and MSC curriculum in the Engineering College Enrichment Program -)

  • 노진아;최유현
    • 공학교육연구
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    • 제17권3호
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    • pp.51-58
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    • 2014
  • The main objective of this research lies in estimating how much importance the educators of professional general education and MSC curriculum put on assessment, and, thereafter, take what support should be provided for the efficient assessment of education. The subjects of this research are educators of professional general education and MSC curriculum in the engineering education enrichment program at the 58 universities out of 72 universities where the accreditation for engineering education is implemented. Accordingly questionnaires were distributed to a total of 58 universities among which 136 questionnaires were collected. The data analysis methods, mean and response sample T test, were used in this research. The following conclusions were drawn from the results of this research. First, tile mean of importance and performance in the 'assessment activities' were relatively high. However, in tile assessment, the assessment performance was relatively lower than the assessment importance. Second, the results of the Importance-Performance Matrix in the 'assessment activities' was analyzed by two ways. First, Analyzed with the scale mean, The result means that Keep up the Good Work (KGW) sector included all factors. Second, Analyzed with the actual mean, The result means that KGW sector included 5 factors A, J, B, D, C. Possible Overkill(PO) sector included factors C, I. Low Priority(LP) sector included 4 factors K, E, H, L. Concentrate Here (CH) sector included factor G.

천수만 퇴적물에서 미량금속의 지화학적 특성 (Trace metals in Chun-su Bay sediments)

  • 송윤호;최만식;안윤우
    • 한국해양학회지:바다
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    • 제16권4호
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    • pp.169-179
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    • 2011
  • 본 연구에서는 미량 금속의 농축 가능성이 제기되는 천수만 퇴적물에 대하여 미량 금속의 조절 요인과 농축 정도를 파악하고자 하였다. 천수만 전역에 걸쳐 27개의 표층 퇴적물을 채취하였으며, 입도, 비표면적, 유기탄소 및 탄산칼슘 함량과 주성분 및 미량 금속(Al, Fe, Na, K, Mg, Ca, Ti, Mn, P, S, Ba, Sr, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Cs, Sc, V, Sn) 농도를 분석하였다. 퇴적물의 총 금속 농도는 크게 3 가지 요인(석영, 희석, 탄산칼슘, 굵은 모래 혹은 정장석)에 의해 조절되었는데 V, Co, Cr, Ni, Cu, Zn, As, Cd는 석영 희석 효과(quartz dilution effect)에 의해 Mn 및 As는 석영 희석 효과와 정장석(굵은 모래) 함량의 복합적 요인에 의해 조절되었다. 농축 인자(enrichment factor) 및 약산(1 M HCl) 용출 실험 결과 천수만 퇴적물에서 미량 금속은 농축되지 않았음을 알 수 있었으며 금속의 농도는 퇴적물의 지화학적 특성들로 잘 설명되었다. 특징적으로 As는 조립질 퇴적물에서도 세립질 퇴적물과 유사한 농도를 보여주었는데, 이것은 조립질 퇴적물 내 Mn 산화물(용출 부분) 및 정장석(잔류 부분)과 밀접한 관련이 있는 것으로 해석되었다. 따라서 퇴적물 중 As의 농축 정도를 평가할 경우, 모래질을 포함하는 시료는 모래질 부분을 따로 분리하거나 $16{\mu}m$보다 작은 세립질 퇴적물의 함량이 10% 이상인 시료만을 대상으로 하는 것이 합리적인 것으로 판단된다.

대학도서관조직의 변화요인고 (A study on the factors changing the university library organizations)

  • 윤희윤
    • 한국도서관정보학회지
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    • 제16권
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    • pp.221-249
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    • 1989
  • The purpose of this study is to analyze the factors influencing on the organizational changes of the university libraries. Results of the analysis, that is, factors that cause the library organization to change, are as follows 1. Changes in library size physical facilities, growth and diversity of library collections, change in personnel organization, role enrichment and faculty status for librarians, management pattern of library director, change in financial su n.0, pport. 2. Change in program : change in goals and objectives, expansion of service programs, enhancement of library functions. 3. Library automation : introduction and development of many library automation projects. 4. Introduction of information technology : development and distribution of computer and related software, telecommunication, and new media. 5. Changes in user needs : many-sided demands for collections, spaces, and services. 6. Many other environmental factors related to library organization.

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항알러지와 건강 기능성식품에 의한 식품 알러지 개선방안

  • 임병우;김주영
    • 식품기술
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    • 제15권4호
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    • pp.29-35
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    • 2002
  • To prevent the incidence of type food allergies, removal of food allergens by excluding all foodstuffs containing the allergen(s) or disruption of allergen(s) using proteases has been employed. Though allergen- specific digestion with a protease worked well in the preparation of low allergenic goods, it is often difficult to destroy allergenicity without adversely affecting the nutritive value, taste and rheological properties of foods. In the present study, we represented that herbs component contained both allergy- enhancing and inhibiting factors, in addition to llergens. We also reported that herbal component such as epigallocatechingallate (EGCG) and epicatechingallate (ECG) is possible to be allergy- inhibiting factors, but the exact mechanism by which they alleviate allergic response is left to be clarifying. Document of allergy enhancing factors and enrichment of allergy inhibiting factors may provide a new approach to diminish allergenicity of various foodstufffs. Clarification of the allergic reaction modifying mechanism of food components and optimization of the intake of allergy modifying factor are necessary for decrement of allergenicity of conventional food and prevention of incidents of allergic response

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Risk analysis using PROMETHEE method In Building Construction MANAGEMENT

  • Jang-Young Lee;You-Sang Yoon;Myung-Houn Jang;Sang-Wook Suh
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1364-1369
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    • 2009
  • The building construction projects include a variety of risk factors due to uncertainties. To succeed in the projects, it is important how risks are managed. Risk management is composed of identification, analysis and response. Especially, the risk analysis is important to objectively calculate significance of risk factors. This paper evaluates a method to find priorities of risks using the AHP(Analytic Hierarchy Process). The method has some defects; (1) the consistency becomes weak as the number of pair-wise compared risks is large, and (2) the input and output procedures are complex when risks are added to or removed from a risk database. Thus the paper adopt the PROMETHEE(Preference Ranking Organization METHod Enrichment Evaluations) analysis process which is able to overcome the limitation of the AHP restricted to 9 risk factors. The PROMETHEE method makes the procedure of risk analysis simple, when the risk factors pull out and put in the risk database. The purpose of this study is to prove the possibility of the PROMETHEE analysis process by being compared with AHP.

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한국이 탐사 중인 해저광물자원의 희유금속 함량과 의미 (Rare Metal Contents and Their Implications of Seabed Mineral Resources Explored by Korea)

  • 박상준;문재운;이경용;지상범
    • 자원환경지질
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    • 제43권5호
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    • pp.455-466
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    • 2010
  • 한국이 현재 탐사하고 있는 해저광물자원의 유형은 망간단괴, 망간각, 다금속황화광체 등으로 구분된다. 망간단괴에 함유되어 있는 주요 희소금속은 Pt로 지각함량 대비 최대 400 배까지 부화되어 있다. 망간단괴의 총 희토류 함량은 0.037~0.302 REO %, 평균 0.12 REO %를 보인다. 망간각의 주요 희소금속은 Te 및 Pt로 각각 10800 배, 150배 정도의 부화량을 보인다. 총 희토류 함량은 0.013-0.387 REO %, 평균 0.18 REO %로 망간단괴 보다 다소 높은 함량을 보인다. 다금속화황광체의 주요 희소금속은 Se 및 In으로 각각 1300 배, 110 배의 높은 부화량을 보이며, 금(0.8~26.3 g/t), 은(0.9~348.0 g/t) 등의 귀금속이 함유된다. 해저광물자원에 함유되어 있는 희유금속은 채광 예상 금속 종인 Co, Ni, Cu 등의 채광 경제성을 높여 줄 것으로 생각되며 첨단산업을 위한 희유금속 확보 차원에서 의미가 있다.

미량 중금속의 농축 및 정량을 위한 폴리에틸렌이민-폴리메틸렌폴리페닐렌 이소시안에이트에 토대한 킬레이트 수지의 합성에 관한 연구(II) : 루빈산이 결합된 카르복시메틸화된 폴리아민-폴리우레아 수지 (Studies on the Polyethylenimine-Polymethylenepolyphenylene Isocyanate Backbone Chelating Resin Synthesis for the Trace Heavy Metals Enrichment and Analysis(II) : Rubeanic Acid Loaded Carboxymethylated Polyamine-Polyurea Resin)

  • 정용순;이강우;황종연;임광수
    • 분석과학
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    • 제6권5호
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    • pp.435-442
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    • 1993
  • 루빈산이 결합된 카르복시메틸화된 폴리아민-폴리우레아(RCCPPI) 수지가 클로로카르복시메틸화된 폴리아민-폴리우레아(CCPPI) 수지와 루빈산으로부터 1단계 반응에 의하여 합성되었다. 이 수지의 구조는 적외선 분광광도법, 원소분석 및 시차열분석법으로 확인되었다. 이 수지에 대한 중금속 흡착특성은 용액의 pH를 변화시키면서 뱃치법에 의하여 분포계수($K_d$)를 측정하고, 프론탈크로마토그래피법으로 관류점을 측정하여 조사하였다. 중금속 이온용액을 이 수지로 충진된 관에 통과시킴에 의하여 고농도의 나트륨, 칼슘 및 아세트산염 용액 중에 존재하는 미량 중금속 이온을 최적 pH에서 농축 및 회수 정량할 수 있었다. 농축 인자는 25 이상이었고 흡착된 중금속들은 0.025M EDTA 용액(pH 9.0)으로 회수 정량하였다.

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공업지역 대기 중 입자에 함유된 미량금속의 화학종별 분석 (Chemical Speciation of Trace Metals in Airborne Particles at An Industrialized Site)

  • 정기호;이지영;문지용;이성인
    • 한국환경과학회지
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    • 제15권6호
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    • pp.503-511
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    • 2006
  • Airborne particles collected from a heavily industrialized site were analyzed by chemical speciation of seven trace metals: Pb, Cd, Cr, Cu, Ni, Zn, and As. The average concentrations were as follows: $Zn,\;502.0{\pm}230.7;\;Pb,\;176.5{\pm}310.9;\;Cu,\;111.9{\pm}82.7;\;As,\;38.0{\pm}31.0;\;Cr,\;21.5{\pm}24.4;\;Cd,\;20.8{\pm}17.4;\;and\;Ni,\;11.4{\pm}8.4\;ng/m^3$. The median enrichment factor (EF) values of Cd (7,280), As (1,030), Cu (215), Zn (214), and Pb (143), with respect to iron, were much larger than 100. We observed that Cd was found in the soluble and exchange- able form (56.9%), and that Pb and Cr were found in carbonates, oxides and the reducible form (69.8% and 61.1%, respectively). These two forms, which are the most easily absorbed into human body tissue, predominated in most of the trace metals investigated in this study.