• 제목/요약/키워드: electrostatic field

검색결과 301건 처리시간 0.025초

잿빛곰팡이병균(Botrytis cinerea)에 대한 N-Phenyl-O-phenyl-thionocarbamate 유도체들의 살균활성에 관한 3D-QSAR 분석 (3D-QSAR Analysis on the Fungicidal Activity of N-phenyl-O-phenylthionocarbamate Analogues against Gray Mold (Botrytis cinerea))

  • 성낙도;박기한;장석찬;성민규
    • 농약과학회지
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    • 제11권2호
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    • pp.59-66
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    • 2007
  • 감수성(SBC) 및 저항성(RBC) 잿빛곰팡이병균(Botrytis cinerea)에 대한 N-phenyl-O-phenylthionocarbamate 유도체들의 살균활성에 대한 3차원적인 구조와 활성과의 관계(3D-QSAR)를 CoMFA와 CoMSIA 방법으로 검토하였다. 최적화 된 CoMFA 모델의 예측성과 상관성이 CoMSIA 모델보다 양호하였으며 ($r^2$$q^2=CoMFA{\gg}CoMSIA$) SBC 균주에 대한 살균활성 모델이 RBC에 대한 모델보다 양호한 통계값 ($r^2=SBC{\gg}RBC$)을 나타내었다. 또한, CoMFA 모델에서는 정전기장보다 입체장이 큰 영향을 미쳤다. CoMSIA 모델에서는 RBC 및 SBC에 대한 살균활성에 관한 CoMSIA장의 영향은 서로 상이하였으나 수소결합 주게장의 영향은 같았다. 통계적으로 양호한 CoMFA 모델에 의하여 두 균주사이 살균활성에 관한 선택성 요소는 입체장의 차이에 기인하는 것으로 판단된다. 그러므로 N-phenyl 고리상 meta 및 para-치환체의 큰 입체장은 SBC에 대한 살균활성을 향상시킬 것으로 예측되었다.

Recent Developments in Agricultural Sprays : Review

  • No, S. Y.
    • Agricultural and Biosystems Engineering
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    • 제3권1호
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    • pp.44-54
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    • 2002
  • A brief review of current status in the field of agricultural spray and future research challenges are presented. Researches on the pesticides sprays, pollen sprays, postharvest sprays, and biological control agent sprays among the various applications of agricultural spray were selected and reviewed. In the agrochemical sprays, the techniques to increase the deposition such as electrospray and reduce the drift such as introductions of drift retardants and of mechanical means are reviewed. The introduction of mechanical means includes low drift, air-assisted, air inclusion, shield or shroud assisted and pulse flow nozzles. For flat fan nozzles, the data of breakup length and thickness of liquid sheet are essential to understand the atomization processes and develop the transport model to target In the air-assisted spray technology to reduce drift, further works on the effect of application height on drift and air assistance on droplet size should be followed. In addition, methods for quantifying the included air in the air inclusion techniques are required. The atomization characteristics of biopesticides spray are not being elucidated and the formulations of biopesticides should be taken into account the spray characteristics of existing nozzle and sprayer. A few researches on the droplet size of fallout can be found in the literature. A combined technology with electrostatic method into one of method for the reduction of drift may be an effective strategy for increasing deposition and reducing drift. Only an integrated approach involving all stakeholders such as engineers, chemists, and biologists, etc. can result in improved application of agricultural spray.

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다중벽 탄소나노튜브와 금나노입자를 사용한 나노박막의 특성연구 (Characterization of Au-MWNT nanocomposite in thin films)

  • 김정수;배종성;고창현;오원태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.49-49
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    • 2009
  • Nanocomposites of gold nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared by electrostatic interaction. Gold nanopartic1es were stabilized by polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and poly(sodium-4-styrenesulfonate) (PSS) in aqueous medium, and MWNTs were modified by poly(diallyldimethylammonium)chloride (PDDA) in water. The as-perpared Au-MWNT nanocomposites were structurally and electrically characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV/Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclo voltammetry (CV). UV/Vis spectra of Au-MWNT nanocomposites showed the characteristic surface plasmon bands in the range of ~515nm, depending on the stabilizers. There is only slight change on the band shape with variation of stabilizing agents for gold nanoparticles. Through FE-SEM and TEM images, the distribution of gold, nanoparticles on the sidewalls of MWNTs was deliberately investigated on Au-MWNT nanocomposites treated with different stabilizers. XPS and CV showed redistribution of electron densities and changes in the binding energy states of nanopartic1es in nanocomposite respectively.

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전기집진장치에서 가스의 물리적인 특성에 따른 포집구역내의 입자포집율 연구 (A Study on the Mass Collection Efficiency in Collector Step of Electrostatic Precipitator by Physical Gas Characterization)

  • 하상안;임경택;신남철
    • 한국환경과학회지
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    • 제7권1호
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    • pp.36-40
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    • 1998
  • This study was carried out to investigate the collection Efficiency of mass in collector step at the different of physical gas characterization. This work has focused on the dependence of the collection efficiency of mass in the collector zone of a two-stage set up field with gas temperature T and the dew point tmeperature. To identify the dependence of the mass collection efficiency on the Bounded plate of the collector zone MP.k by the spectre electric resistance of dust $p_e$. and the relative humidify ${\varphi}$, 20 at- tempts have been made with three different gas temperature ($50{\circ}C, 80{\circ}C, 110{\circ}C$) at different dew point. At the specific electric resistance of dust $p_e$=$10^6{\Omega}m$ which relative humidity corresponds to $\phi$ > 15%, a easy rise of the sounded plate secluded dust mass share was measured atwain. As the result of the higher cohesion imprisonment power due to the adsorbtion of particle, the rinse of the relative humidity developed on the particle surface. Therefore, the collection efficiency of mass was not predominant the high temperature T in the collector zone, neither was the pecific ellectric resistance of dust dependent.

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선량 중첩을 이용한 멀티형 연 X-선 정전기 제거장치의 개발 (Development of Multi-Type Soft X-ray Ionizer using Radiation Dose Overlapped Effect)

  • 이수환;이동훈
    • 한국안전학회지
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    • 제33권2호
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    • pp.28-31
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    • 2018
  • In display and semi-conductor manufacturing process, there are numerous unstable factors such as particle concentration, minimal vibration, changes in magnetic field, or electrostatic that becomes an issue to be managed and controlled. In the recent, X-ray ionization is widely used that is neutralized by separating air or gas molecules in the area where the static must be resolved. The mono-type of X-ray ionizer was not capable to be used in $8^{th}$ generation panels manufacturing plant due to its insufficient ionizing coverage since the panel itself is approximately in $2m{\times}3m$. To resolve the current problem, the development of new type called, "Multi-type X-ray ionizer" has resulted in covering enough ionizing space in $8^{th}$ generation panels industry. Comparing mono and multi types with MCNPX code simulation, the multi one indicates more X-ray flux, efficiency, and ionization performance in comparison with either a mono-type or multi-type in array format. In addition, the ionizing efficiency of overlapping area with multi-type showed 30% higher effectiveness rate as to the ordinary mono-type.

Electrical and Thermo-mechanical Properties of DGEBA Cycloaliphatic Diamine Nano PA and SiO2 Composites

  • Trnka, Pavel;Mentlik, Vaclav;Harvanek, Lukas;Hornak, Jaroslav;Matejka, Libor
    • Journal of Electrical Engineering and Technology
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    • 제13권6호
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    • pp.2425-2433
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    • 2018
  • This study investigates a new organic based material and its dielectric and mechanical properties. It is a comprehensive nanocomposite comprising a combination of various types of nanofillers with hydrophobic silica nanoparticles (AEROSIL R 974) as a matrix modifier and a polyamide nano nonwoven textile, Ultramid-Polyamide 6, pulped in the electrostatic field as a dielectric barrier. The polymer matrix is an epoxy network based on diglycidyl ether of bisphenol A (DGEBA) and cycloaliphatic diamine (Laromine C260). The designed nanocomposite material is an alternative to the conventional three-component composites containing fiberglass and mica with properties that exceed current electroinsulating systems (volume resistivity on the order of $10^{16}{\Omega}{\cdot}m$, dissipation factor tan ${\delta}=4.7{\cdot}10^{-3}$, dielectric strength 39 kV/mm).

Phenoxy, Phenylthio 및 Benzyloxy-기가 치환된 Quinolone 유도체들의 항트리파노소마 활성에 대한 3D-QSAR 분석 (3D-QSAR Analysis on the Antitrypanosomal Activity of Phenoxy, Phenylthio or Benzyloxy Group Substituted Quinolone Analogues)

  • 명평근;강나나;김상진;성낙도
    • 약학회지
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    • 제54권4호
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    • pp.288-294
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    • 2010
  • Three dimensional quantitative-structure relationships (3D-QSARs) models between structures of phenoxy, phenylthio or benzyloxy substituted quinolone analogues and their antitrypanosomal activity against Chagas disease (Trypanosoma cruzi) were derived and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The optimized CoMFA 1 model ($q^2$=0.528 and $r^2$=0.964) showed the best statistical results. According to the optimized CoMFA 1 model, the antitrypanosomal activities were dependent on the steric (60.0%) and electrostatic (36.2%) factors of quinolone derivatives. From the contour maps, it is predicted that the activity will be increased when sterically favored groups were located in $R_4$ and $R_5$ position and sterically disfavored groups were located in $R_2$ position. Also, the positively charged groups on $R_2$ would be able to increase the antitrypanosomal activities.

하폐수처리에서 질소 제거를 위한 미생물 전기화학 기술의 동향 (Trends of microbial electrochemical technologies for nitrogen removal in wastewater treatment)

  • 채형원;최용훈;김명운;김영진;정석희
    • 상하수도학회지
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    • 제34권5호
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    • pp.345-356
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    • 2020
  • The removal of organic carbon and nutrients (i.e. N and P) from wastewater is essential for the protection of the water environment. Especially, nitrogen compounds cause eutrophication in the water environment, resulting in bad water quality. Conventional nitrogen removal systems require high aeration costs and additional organic carbon. Microbial electrochemical system (MES) is a sustainable environmental system that treats wastewater and produces energy or valuable chemicals by using microbial electrochemical reaction. Innovative and cost-effective nitrogen removal is feasible by using MESs and increasing attention has been given to the MES development. In this review, recent trends of MESs for nitrogen removal and their mechanism were conclusively reviewed and future research outlooks were also introduced.

IGFET 채널 전류 밀도의 공간 변조 현상에 관한 연구 (Space Modulation of the Channel Current Density in IGFET by the Polarized Metal Gates)

  • 라극환
    • 대한전자공학회논문지
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    • 제21권4호
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    • pp.31-36
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    • 1984
  • 지난 수십년동안 많은 자학자들에 의해 초고주파대에서 부성 임피던스를 갖는 반도체 소자들이 개발되어 왔으나 이 소자들은 진공관 소자에 비하여 매우 낮은 출력으로 동작되고 있다. 그러므로 본 논문에서는 절연된 반도체 위에 주기적인 복수 게이트를 가진 MOSFET를 제안하여 연구하였다. 채널에 인하여 게이트상에 전압분포를 유기하고 이와같이 게이트 사이에 야기된 전위차는 채널에서 캐리어의 속도 또는 전류밀도의 공간변조를 일으키게 됨을 입증하여 이 소자가 고출력의 초고주파용 소자로 동작할 수 있는 가능성을 연구한다.

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Use of Conformational Space Annealing in Molecular Docking

  • Lee, Kyoung-Rim;Czaplewski, Cezary;Kim, Seung-Yeon;Lee, Joo-Young
    • 한국생물정보학회:학술대회논문집
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    • 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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    • pp.221-233
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    • 2004
  • Molecular docking falls into the general category of global optimization problems since its main purpose is to find the most stable complex consisting of a receptor and its ligand. Conformational space annealing (CSA), a powerful global optimization method, is incorporated with the Tinker molecular modeling package to perform molecular docking simulations of six receptor-ligand complexes (3PTB, 1ULB, 2CPP, 1STP, 3CPA and 1PPH) from the Protein Data Bank. In parallel, Monte Carlo with minimization (MCM) method is also incorporated into the Tinker package for comparison. The energy function, consisting of electrostatic interactions, van der Waals interactions and torsional energy terms, is calculated using the AMBER94 all-atom empirical force field. Rigid docking simulations for all six complexes and flexible docking simulations for three complexes (1STP, 3CPA and 1PPH) are carried out using the CSA and the MCM methods. The simulation results show that the docking procedures using the CSA method generally find the most stable complexes as well as the native -like complexes more efficiently and accurately than those using the MCM, demonstrating that CSA is a promising search method for molecular docking problems.

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