• 제목/요약/키워드: Field effects

검색결과 7,552건 처리시간 0.042초

현장실험을 통한 침사구의 효과 분석 (Field Experimental Analysis of Effects of Sediment Traps)

  • 최경숙;장정렬
    • 한국관개배수논문집
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    • 제21권1호
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    • pp.99-108
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    • 2014
  • This study investigated the effects of NPS(non point source) pollution reduction of sediment traps through field experiments. Various sizes of 4 sediment traps were applied in a upland field located in Gunwi and assessed the infiltration and storage effects as well as NPS pollution reduction effects of this technique. The characteristics of deposited soil in the sediment traps were also analyzed including distribution of particle size, soil texture, and chemical properties. The results showed that slightly different composition of soil particle size from each sediment trap with high proportion of 0.15mm and 0.25mm ranges of soil particle diameters, while the loamy sand is the main types of deposited soils in the sediment traps. Decreased NPS pollution were observed from the water quality analysis of the samples taken from the sediment traps. Further research need to be proceeded continuously to improve this technique in order to utilize on upland fields for management of agricultural NPS pollutions.

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핵비등에서 기포의 동특성에 대한 전기장의 효과 (Effects of an Electric Field on the Dynamic Characteristics of Bubbles in Nucleate Boiling)

  • 권영철;장근선;권정태;김무환
    • 설비공학논문집
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    • 제12권11호
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    • pp.963-971
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    • 2000
  • In order to investigate the effects of an electric field on EHD(Electro-hydrodynamic) nucleate boiling hat transfer characteristics in a nonuniform electric field under saturated pool boiling, the basic study has been performed experimentally. In the present study, the working fluid is R-113 and the plate-wire electrode system is used to generate a steep electric field gradient. Boiling parameters are investigated by using a high speed camera. The electric field distribution around a wire is obtained to understand the effect of an electric field on bubble departure/movement. The experimental results show EHD effects are much more considerable when the applied voltage increases. Bubbles depart away from the heated wire in radial direction. It is confirmed that the mechanisms of EHD nucleate boiling are closely connected with the dynamic behavior of bubbles. The boiling parameters are significantly changed by the electric field strength. With increasing applied voltages, the bubble size decreases and the nucleation site density, bubble velocity and bubble frequency increase.

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Effects of Training Contents on the Work Effectiveness of Learning Workers in the Software field

  • Yoo, Hang-Suk;Seo, Jeong-Man
    • 한국컴퓨터정보학회논문지
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    • 제24권6호
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    • pp.29-35
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    • 2019
  • In this paper, the effects of educational contents on job behavior, the effects of job behavior on job effectiveness and the effects of educational contents on job effectiveness were studied when working in the Software field. For this purpose, a questionnaire survey was conducted on the learning workers who conducted the training in the IT field, and 302 valid questionnaires were used for the analysis. The research model was set up to test exploratory factor and confirmatory factor analysis and hypothesis, and the research hypothesis was tested by applying structural equation. The effects of job behavior on job effectiveness were positively related to job satisfaction, customer orientation, and organizational commitment.

Polarity Effects of Dielectric Anisotropy on Electro-Optical Characteristics of Fringe Field Twisted Nematic Mode

  • Shin, Sung-Sik;Jhun, Chul-Gyu;Kim, Woo-Young
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.288-288
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    • 2009
  • We have studied polarity effects of dielectric anisotropy effects on electro-optical characteristics of a twisted nematic mode driven by fringe electric field, which has wide viewing angle characteristics. Our device is designed as normally black mode between parallel polarizers. The perfect polarization conversion of incident light, which passes through a polarizer, is achieved, when it passes through the twisted liquid crystal (LC) layer. If an electric field is applied, the LC molecules with a positive (or negative) dielectric anisotropy rotate parallel (or perpendicular) to the horizontal component of a fringe electric field as increasing transmittance. From the calculated results, enhanced transmittance of the fringe field-twisted nematic (FF-TN) mode with positive dielectric anisotropy of + 8.2 can be obtained.

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뇌 확산강조 자기공명영상에 대한 정량적, 성적 평가: 1.5 T와 3.0 T 기기 비교 (Quantitative and Qualitative Evaluation of Brain Diffusion Weighted Magnetic Resonance Imaging: Comparision with 1.5 T and 3.0 T Units)

  • 구은회;동경래
    • 방사선산업학회지
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    • 제10권4호
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    • pp.227-230
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    • 2016
  • DWI of biological effects are independent of magnetic field strength in various regions. High field strength, however, does affect the signal to noise ratio (SNR) and artifacts of diffusion weighted imaging (DWI) images, which ultimately will influence the quantitative of diffusion imaging. In this study, the effects of field strength on DWI are reviewed. The effects of the diseases also are discussed. Comparing DWI in cerebellum, WM, GM, Hyperacute region measurements both as a function of field strength (1.5T and 3.0T). Overall, the SNR of the DWI roughly doubled going from 1.5 T to 3.0 T. In summary, DWI studies at 3.0 T is provided significantly improved DWI measurements relative to studies at 1.5T.

A cylindrical shell model for nonlocal buckling behavior of CNTs embedded in an elastic foundation under the simultaneous effects of magnetic field, temperature change, and number of walls

  • Timesli, Abdelaziz
    • Advances in nano research
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    • 제11권6호
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    • pp.581-593
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    • 2021
  • This model is proposed to describe the buckling behavior of Carbon Nanotubes (CNTs) embedded in an elastic medium taking into account the combined effects of the magnetic field, the temperature, the nonlocal parameter, the number of walls. Using Eringen's nonlocal elasticity theory, thin cylindrical shell theory and Van der Waal force (VdW) interactions, we develop a system of partial differential equations governing the buckling response of CNTs embedded on Winkler, Pasternak, and Kerr foundations in a thermal-magnetic environment. The pre-buckling stresses are obtained by applying airy's stress function and an adjacent equilibrium criterion. To estimate the nonlocal critical buckling load of CNTs under the simultaneous effects of the magnetic field, the temperature change, and the number of walls, an optimization technique is proposed. Furthermore, analytical formulas are developed to obtain the buckling behavior of SWCNTs embedded in an elastic medium without taking into account the effects of the nonlocal parameter. These formulas take into account VdW interactions between adjacent tubes and the effect of terms involving differences in tube radii generally neglected in the derived expressions of the critical buckling load published in the literature. Most scientific research on modeling the effects of magnetic fields is based on beam theories, this motivation pushes me to develop a cylindrical shell model for studying the effect of the magnetic field on the static behavior of CNTs. The results show that the magnetic field has significant effects on the static behavior of CNTs and can lead to slow buckling. On the other hand, thermal effects reduce the critical buckling load. The findings in this work can help us design of CNTs for various applications (e.g. structural, electrical, mechanical and biological applications) in a thermal and magnetic environment.

Fringe Field Effects on Transient Characteristics of Nano-Electromechanical (NEM) Nonvolatile Memory Cells

  • Han, Boram;Choi, Woo Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권5호
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    • pp.609-614
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    • 2014
  • The fringe field effects on the transient characteristics of nano-electromechanical (NEM) memory cells have been discussed by using an analytical model. The influence of fringe field becomes stronger as the size of a cell decreases. By using the proposed model, the dependency of NEM memory transient characteristics on cell parameters has been evaluated.

Cross Correlated Effects of Radiation Damping and the Distant Dipolar Field with a Pulsed Field Gradient in Solution NMR

  • Chung Kee-Choo;Ahn Sang-Doo
    • 한국자기공명학회논문지
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    • 제10권1호
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    • pp.46-58
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    • 2006
  • With a simple pulse sequence ($\pi/2$-{gradient, duration T}-acquisition) in solution NMR, detected signal has slowly grown up to percents of the equilibrium magnetization. The source of this unusual resurrection of dephased magnetization after a crushed gradient is cross-correlated effects of radiation damping and the distant dipolar field, which has been demonstrated by a numerical simulation and theoretical analysis.

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자기장이 전해복합연마공정에 미치는 영향 (Effects of Magnitic Field on Electrochemical Polishing Process)

  • 김정두;최민석;김동섭
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.108-112
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    • 1994
  • The paper describes the effects of magnetic field on the electrochemical polishing process in the view of ionic in the electrolyte. Theoretical background was suggested how magnetic field increases the material removal efficiency and surface finishing ability Magnetic field changes the jonic movement in the electrolyte from linear motion to curved or complex oscillating one, thus increases the electrolytic current density and, as the results, the finishing efficiency.

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