• 제목/요약/키워드: Contamination source

검색결과 515건 처리시간 0.027초

Evaluation of Different Bed Disinfectants against the Spread of Common Diseases in Silkworm, Bombyx mori L.

  • Irfan Illahi;S. D. Sharma;K. Chrasekharan;B. Nataraju;M. Balavenkatasubbaiah;T. Selvakumar;V. Thiagarajan;S. B. Dandin
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권2호
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    • pp.191-196
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    • 2003
  • Silkworm body and rearing seat disinfection is an integral part of effective silkworm rearing as it prevents the spread of various diseases through secondary contamination in the rearing bed. Many bed disinfectants are recommended by various research institutes in India. In the present study, eight bed disinfectants viz., Vijetha, Labex, Resham Jyothi, Sanjeevini, Suraksha, Reshamkeet Oushadh, Dithane M45 and Captan recommended by various Sericultural Research Institutions in the country against the spread of common diseases of silkworm were tested to determine their comparative efficacy. For the study, all the treatment batches were introduced with fixed number of specific diseased larvae so as to maintain a constant source of pathogen in the bed and then followed by treatment with respective bed disinfectants. Percent mortality/infection due to each disease was recorded to determine efficacy of bed disinfectant treatment against respective disease. The results show that all the bed disinfectants tested have considerable efficacy against the spread of various diseases in the rearing bed. However, Vijetha was distinctly superior in its efficacy against all four major diseases of silkworm. The study emphasize the role of bed disinfectants in silkworm rearing and the fact that they should be judiciously selected based on the efficacy of the bed disinfectant and the type of disease prevalent in a particular season and area.

잠재적 POPs로서의 과불소화화합물의 환경 내 분포 및 거동: 물성, 환경 내 농도수준, 상 분배 및 장거리이동을 중심으로 (Environmental Distribution and Fate of Perfluorinated Compounds (PFCs) as Emerging POPs: Physico-Chemical Properties, Emission, Contamination Level, Inter-phase Distribution and Long-Range Transport)

  • 김승규
    • Environmental Analysis Health and Toxicology
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    • 제23권3호
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    • pp.143-164
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    • 2008
  • Concern about perfluorinated compounds (PFCs) is growing nationally as well as globally. PFCs could be considered emerging POPs due to their environmentally persistent, bioaccumulative, and potentially harmful properties. Moreover. perfluoroalkylates (PFAs) such as PFOS and PFOA are reported to experience long-range transport (LRT) to the Arctic in spite of their low volatility and strong solubility. The possible pathways contributing to LRT have been proposed but are still in debate in combination with unclear source definition and uncertain physico-chemical properties. The environmental fate of PFCs is more complicated because of the presence of precursors that are degraded to PFAs and are extremely different from their daughters, PFAs. in physico-chemical properties. To what extent and through what pathways are human and wildlife exposed is determined by the environmental fate and distribution of PFCs. To define uncertainties in fate and distribution thus is critical to prevent erroneous policy and/or determination related with exposure and risk reduction. This article aimed to review controversy and/or uncertain issues for the environmental fate and distribution of PFCs and to prospect research topics necessary to dissolve uncertainties.

긴급제언 - 광산폐수에 의한 터널라이닝 손상사례 연구 (A Case Study on Damage of The Tunnel Lining by Mine Waste Water)

  • 이유석;오영석
    • 기술사
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    • 제45권4호
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    • pp.47-56
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    • 2012
  • 석탄합리화정책에 따라 많은 가행 광산들이 폐광을 하게 되고 이러한 폐광산들이 오랜 기간동안 방치되면서 폐광주변에는 지반침하, 침출수배출, 경관 훼손등의 환경오염을 수반하게 된다. 정부차원에서 여러 환경오염 방지대책이 진행중이나 이러한 환경오염 방지대책은 대부분 생태보호적인 관점에서 관심의 대상되어 왔고 우리가 이용하는 사회 인프라시설에 대한 영향은 상대적으로 소홀히 되어 왔다. 광산은 대부분 산악에 위치하며 이러한 위치조건상 폐광산 주변 중요 인프라시설로는 터널이 있을 수 있다. 이에 본 논고에서는 폐광산의 대표적 오염원인 광산폐수가 주변의 공용중인 터널에 미치는 영향의 종류와 사례에 대해 소개하였다.

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국내 비상용수 확보량 산정 방법론에 관한 연구 (Establishment of Methodology for Estimating an Emergency Water)

  • 이태국;채선하;김성수;서인석;김정현;박노석
    • 상하수도학회지
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    • 제26권3호
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    • pp.361-372
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    • 2012
  • In order to establish the methodology for estimating an emergency drinking water supply in Korea, overseas cases and accidents history of cutting off water supply were investigated, and questionnaire was conducted. Investigating accidents history of cutting off water supply in Korea, actual cutting off times of most cases were less than 13hours. Also, cases related with water quality and facility failure have been not enough to derive useful information for estimating an emergency water. From the results of questionnaire and cross-tabulation analysis, about 1,066 lpcd(liter per capita${\cdot}$day) as an emergency water and 14 days as tolerable outages time could be estimated. The results of water quality simulation could tell us that it might take 5-16 days for pollutant matter to travel from 15 contamination points to source water intake point in the selected reservoir(D-dam). This travel time was in good accordance with the estimated tolerable outage time, 14days.

무전극 형광램프의 페라이트 특성변화에 따른 전자계 분포 (The Study on Electromagnetic Distribution of Electrodeless Fluorescent Lamp)

  • 김광수;조주웅;허인성;최용성;박대희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1147-1150
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    • 2003
  • The RF inductive discharge or inductively coupled plasma (ICP) continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology Although most practical ICPs operate at 13.56 (MHz) and 2.65 (MHz), the trend to reduce the operating frequency is clearly recognizable from recent ICP developments. In an electrodeless fluorescent lamp, the use of a lower operating frequency simplifies and reduces cost of rf matching systems and rf generators and can eliminate capacitive coupling between the inductor coil and plasma, which could be a strong factor in wall erosion and plasma contamination. In this study, the configuration of ferrite and fixture which operates at the frequency of 2.65 (MHz) will be discussed, by using the electromagnetic simulation (Maxwell 2D).

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Intrinsic alignments of emission line galaxies at z ~1.4 from the FastSound redshift survey

  • Tonegawa, Motonari;Okumura, Teppei;Totani, Tomonori;Dalton, Gavin;Yabe, Kiyoto
    • 천문학회보
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    • 제42권2호
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    • pp.54.1-54.1
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    • 2017
  • Intrinsic alignments (IA), the coherent alignment of intrinsic galaxy orientations, can be a source of a systematic error of weak lensing surveys. The redshift evolution of IA also contains information about the physics of galaxy formation and evolution. We present the first measurement of IA at high redshift, z~1.4, using the spectroscopic catalog of blue star-forming galaxies of the FastSound redshift survey, with the galaxy shape information from the Canada-Hawaii-France telescope lensing survey. The IA signal is consistent with zero with power-law amplitudes fitted to the projected correlation functions for density-shape and shape-shape correlation components, $A_{\delta+}=-0.0040\pm 0.0754$ and $A_{++}=-0.0159\pm 0.0271$, respectively. These results are consistent with those obtained from blue galaxies at lower redshifts (e.g., $A_{\delta+}=0.0035_{-0.0389}^{+0.0387}$ and $A_{++}=0.0045_{-0.0168}^{+0.0166}$ at z=0.51 from the WiggleZ survey), suggesting no strong redshift evolution of IA. The upper limit of the constrained IA amplitude corresponds to a few percent contamination to the weak-lensing shear power spectrum, resulting in systematic uncertainties on the cosmological parameter estimations by $-0.035<\Delta \sigma_8<0.026$ and $-0.025<\Delta \Omega_{\mathrm m}<0.019$.

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풍력발전기 유지보수로봇을 위한 표면 적응 이동 시스템 (A Surface Adaptive Moving Mechanism for Wind Turbine Blade Maintenance Robot)

  • 김병곤;박소라;전민석;전경태;홍대희
    • 한국정밀공학회지
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    • 제30권9호
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    • pp.969-975
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    • 2013
  • As energy shortage is getting more serious, wind energy source is more promoted around the world. Blade is a key component of wind turbine. Local breakages and/or contamination in the blade bring degradation in aerodynamic efficiency and life-time. However, it is not easy and even dangerous for human workers to access the blade for inspection and maintenance since its size is huge and located at high mountains and rough sea, which are windy places. This paper deals with a novel moving mechanism that efficiently carries human workers or robots to the wind turbine blade. The proposed mechanism utilizes flexible tube with pressurized air that rolls and climbs over the blade surface. So, the tube naturally adapts the changing surface of the blade and acts no harm to it. This paper discusses about its concept, detail design, and advantages. The feasibility of the proposed mechanism is proved through experiments prototype.

GM과 non-GM 작물의 공존제도의 정착을 위한 포장의 격리거리에 관한 고찰 (Debates on the isolation distances to segregate fields with GM crops from fields with non-GM crops for the establishment of their coexistence)

  • 이신우
    • Journal of Plant Biotechnology
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    • 제36권3호
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    • pp.261-267
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    • 2009
  • The coexistence policy of GM and non-GM crops is still on the debates in EU since “the recommendation on guidelines for the development of national strategies and best practices to ensure the coexistence of GM crops with conventional and organic farming” has been reported in 2003. The major issues are maximum tolerance level of GMO admixture and minimum isolation distances of GM fields with others including conventional, organic and seeds production. Majority of member states in EU proposed that the tolerance level of GMO admixture must be more strictly controlled, in particular in the fields for organic crops and seeds production. To this end, it was proposed that minimum isolation distances to segregate GM crops from fields with organic crops and seeds production need to be further extended than those of conventional crops since cross pollination with other crops adjacent GM fields is known as the most prevalent source for GMO contamination. In these circumstances, it is strongly suggested that the current legislations need to be revised including the minimum isolation distances of fields for each species before field cultivation for a commercial GM crop is approved for the first time in South Korea.

Real-time Assay of Toxic Lead in In Vivo Living Plant Tissue

  • Ly, SuwYoung;Kim, Nack Joo;Youn, Minsang;Kim, Yongwook;Sung, Yeolmin;Kim, Dohoon;Chung, Tackhyun
    • Toxicological Research
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    • 제29권4호
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    • pp.293-298
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    • 2013
  • A method of detecting lead was developed using square wave anodic stripping voltammetry (SWASV) with DNA-carbon nanotube paste electrode (CNTPE). The results indicated a sensitive oxidation peak current of lead on the DNA-CNTPE. The curves were obtained within a concentration range of 50 $ngL^{-1}-20mgL^{-1}$ with preconcentration time of 100, 200, and 400 sec at the concentration of $mgL^{-1}$, ${\mu}gL^{-1}$, and $ngL^{-1}$, respectively. The observed relative standard deviation was 0.101% (n = 12) in the lead concentration of 30.0 ${\mu}gL^{-1}$ under optimum conditions. The low detection limit (S/N) was pegged at 8 $ngL^{-1}$ ($2.6{\times}10^{-8}M$). Results showed that the developed method can be used in real-time assay in vivo without requiring any pretreatment and pharmaceutical samples, and food samples, as well as other materials requiring water source contamination analyses.

6 MeV 전자선의 물팬텀 속의 선량분포에 관한 모의계산 (The Simulation on Dose Distributions of the 6 MeV Electron Beam in Water Phantom)

  • 이정옥;정동혁;문성록
    • 대한방사선기술학회지:방사선기술과학
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    • 제23권2호
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    • pp.75-79
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    • 2000
  • This study was performed for the clinical applications applying the Monte Carlo methods. In this study we calculated the absorbed dose distributions for the 6 MeV electron beam in water phantom and compared the results with measured values. The energy data of electron beam used in Monte Carlo calculation is the energy distribution for 6 MeV electron beam which is assumed as a Gaussian form. We calculated percent depth doses and beam profiles for three field sizes of $10{\times}10,\;15{\times}15$, and $20{\times}20\;cm^2$ in water phantom using Monte Carlo methods and measured those data using a semiconductor detector and other devices. We found that the calculated percent depth doses and beam profiles agree with the measured values approximately. However, the calculated beam profiles at the edge of the fields were estimated to be lower than the measured values. The reason for that result is that we did not consider the angular distributions of the electrons in phantom surface and contamination of X-rays in our calculations. In conclusion, in order to apply the Monte Carlo methods to the clinical calculations we are to study the source models for electron beam of the linear accelerator beforehand.

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