• Title/Summary/Keyword: Drift current

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Planar Hall Resistance Sensor for Monitoring Current

  • Kim, KunWoo;Torati, Sri Ramulu;Reddy, Venu;Yoon, SeokSoo
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.151-154
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    • 2014
  • Recent years have seen an increasing range of planar Hall resistive (PHR) sensor applications in the field of magnetic sensing. This study describes a new application of the PHR sensor to monitor a current. Initially, thermal drift experiments of the PHR sensor are performed, to determine the accuracy of the PHR signal output. The results of the thermal drift experiments show that there is no considerable drift in the signals attained from 0.1, 0.5, 1 and 2 mA current. Consequently, the PHR sensor provides adequate accuracy of the signal output, to perform the current monitoring experiments. The performances of the PHR sensor with bilayer and trilayer structures are then tested. The minimum detectable currents of the PHR sensor using bilayer and trilayer structures are $0.51{\mu}A$ and 54 nA, respectively. Therefore, the PHR sensor having trilayer structure is the better choice to detect ultra low current of few tens nanoampere.

Late Pleistocene Variation in Intensity of Deep Western Boundary Current from Vertical Change in Size of Terrigenous Silt in the Rekohu Sediment Drift, SW Pacific (남서태평양 리코후 드리프트 퇴적층의 쇄설성 실트입자 크기의 수직적 변화를 이용한 플라이스토세 후기 심해서안경계해류의 세기 변화)

  • Kim, B.K.;Lee, Y.J.;Park, Y.H.;Bahk, J.J.
    • Ocean and Polar Research
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    • v.28 no.4
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    • pp.451-457
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    • 2006
  • Hole 1124 of ODP Leg 181 was located in the Rekohu sediment drift off eastern New Zealand in the southwest Pacific Ocean. Mean gain sizes of sortable silt were measured in two drilled cores (1124A and l124B). Chronostratigraphy of core 1124 was correlated with the well-dated nearby core S931, resulting that the age of core 1124 covers the late Pleistocene spanning about MIS (Marine Isotope Stage) 5. Mean grain size of sortable silt seemed to be relatively large during the glacial period, whereas that of the interglacial period was smaller, although several tephra layers contain some coarse-grained pyroclatic particles. The variation in mean grain size of sortable silt in Rekohu sediment drift during the late Pleistocene indicates that the intensity of Deep Western Boundary Current (DWBC) might have been enhanced during the glacial period as a result of increased production of Antarctic Bottom Water (AABW).

Measurement of the Drift Velocity for Electron Swarm in a Alkali Metal Using a Induced Current Method (유도 전류법을 이용한 알칼리 금속중에서 전자군의 이동속도 측정)

  • Baek, Yong-Hyeon;Ha, Seong-Cheol;Lee, Bok-Hui;Yu, Gwang-Sik
    • Proceedings of the KIEE Conference
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    • 1985.07a
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    • pp.215-218
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    • 1985
  • In this paper, The electron drift velocity was measured from an experimental study of the open end heat pipe system by induced current method as alkali metal vapour was generated in ordinary region of a drift tube. The test condition was alkali metal vapour range from 3.6 to 20.1(Torr), temperature of 667 to 755(K), and E/N of $1{\times}10^{-16}$ to $1{\times}10^{-15}(v.cm^2)$. The results of this study were obtained essentially the same as the extrapolated prediction curve for electron drift velocity in the alkali metal Vapour of J. Lucas et 31 with range of E/N: $1{\times}10^{-17}$ to $1{\times}10^{-16}(v.cm^2)$, and the electron drift velocity was obtained the result an increase in alkali to E/N range from E/N $2.8{\times}10^{-17}$ to $5.6{\times}10^{-16}(v.cm^2)$ (E/N From 2.8 to 50 Td).

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Temperature dependency of magnetic field drifts of HTS pancake coils for NMR/MRI applications

  • Choi, Kyeongdal;Lee, Seyeon;Kim, Woo-Seok;Lee, Sang Min
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.4
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    • pp.44-47
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    • 2013
  • We had proposed a winding method so called "Wind-and-Flip", which enables a persistent current operation of an HTS pancake coil without any electrical joint. In order to improve the magnetic field drift characteristics, a prototype HTS coil with the technique was fabricated, and tested under various temperatures. Because the coil doesn't have any electric terminals for current leads, an HTS background magnet was used to induce the persistent current in the coil by field cooling process. A conduction cooling system with a GM cryocooler was prepared to keep the operating temperatures of the prototype coil much below the 77 K. We investigated the magnetic field drift characteristics under the various operating temperatures by measuring the center magnetic field with a cryogenic Hall sensor. The persistent current mode operation at 20 ~ 50K showed a strong possibility of the winding technique for the application such as MRI or NMR.

On The Seasonal Variations Of Surface Current In The Eastern Sea Of Korea (August 1979 - April 1980)

  • Lee, Jae Chul;Chung, Whang
    • 한국해양학회지
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    • v.16 no.1
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    • pp.1-11
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    • 1981
  • The seasonal variations of surface current patterns in the Japan Sea were drawn out from the results of drift bottle experiments, current measurements and hydrographic observations during 1979∼1980. The North Korean Cold Current(NKCC) and the East Korean Warm Current(EKWC) were common features of circulation in the eastern sea of Korea. The intrusion of NKCC along the Korean coast became strong in summer(average velocity of 47.4cm/sec off Jumunjin and 23.4cm/sec near Jugbyeon) when the Tsushima Current was strong. But there was no indication of the NKCC in November 1979. Dynamic topography(August & November 1979) and satellite picture(November 1979) seemed to show the topographic steering of EKWC beginning off Janggigab. Drift bottles arrived at the Japaness coast were affected significantly by the strong Tsushima Current in summer and by the predominant northwesterlies in winter instead of weak current.

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Dependency of Tunneling Field-Effect Transistor(TFET) Characteristics on Operation Regions

  • Lee, Min-Jin;Choi, Woo-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.11 no.4
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    • pp.287-294
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    • 2011
  • In this paper, two competing mechanisms determining drain current of tunneling field-effect transistors (TFETs) have been investigated such as band-to-band tunneling and drift. Based on the results, the characteristics of TFETs have been discussed in the tunneling-dominant and drift-dominant region.

Electrical Drift Mobility in the Cholesteryl Benzoate (Cholestric 액정 Cholesteryl Benzoate에서 Drift Mobility측정)

  • 강태원;김화택
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.15 no.2
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    • pp.19-21
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    • 1978
  • The electrical drift mobility of charge carrier of Cholesteryl Benzoate was measured by Polarity inversion method in the temperature range 140~ 185$^{\circ}C$. with a view to revealing the mechanism of charge carrier transport. The electrical drift mobility of charge carrier of that increased from 2.5$\times$10-7$\textrm{cm}^2$/V.sec to 2.0$\times$10-6$\textrm{cm}^2$/v.sec as the temperature increased. As a result of the experiment, the mechanism of current transport is believed to be ionic mechanism.

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Evaluation of Optical Characteristics by Panel Current Analysis for Charged Particle Type Display (대전입자형 디스플레이의 패널전류 분석에 의한 광특성 평가)

  • Park, Sun-Woo;Kwon, Ki-Young;Chang, Sung-Keun;Kim, Young-Cho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.10
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    • pp.844-849
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    • 2009
  • The moving behavior of particle with voltage biasing is studied by analyzing the displacement current generated in electrodes and the drift current by moving particles in cell gap. These currents are ascertained by optical reflectivity on the panel. We obtained the saturated current after a peak in threshold voltage which is coincide with reflectivity of 80%. These saturated optical reflectivity and its drift current offer optimum q/m of particles and driving voltage and can be analytically studied on grey scale methods. Especially regional analysis is useful to aging and driving voltage and the understanding of operating mechanism of charged particle type display.

Recent Developments in Agricultural Sprays : Review

  • No, S. Y.
    • Agricultural and Biosystems Engineering
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    • v.3 no.1
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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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Fragility assessment of buckling-restrained braced frames under near-field earthquakes

  • Ghowsi, Ahmad F.;Sahoo, Dipti R.
    • Steel and Composite Structures
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    • v.19 no.1
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    • pp.173-190
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    • 2015
  • This study presents an analytical investigation on the seismic response of a medium-rise buckling-restrained braced frame (BRBF) under the near-fault ground motions. A seven-story BRBF is designed as per the current code provisions for five different combinations of brace configurations and beam-column connections. Two types of brace configurations (i.e., Chevron and Double-X) are considered along with a combination of the moment-resisting and the non-moment-resisting beam-to-column connections for the study frame. Nonlinear dynamic analyses are carried out for all study frames for an ensemble of forty SAC near-fault ground motions. The main parameters evaluated are the interstory and residual drift response, brace displacement ductility, and plastic hinge mechanisms. Fragility curves are developed using log-normal probability density functions for all study frames considering the interstory drift ratio and residual drift ratio as the damage parameters. The average interstory drift response of BRBFs with Double-X brace configurations significantly exceeded the allowable drift limit of 2%. The maximum displacement ductility characteristics of BRBs is efficiently utilized under the seismic loading if these braces are arranged in the Double-X configurations instead of Chevron configurations in BRBFs located in the near-fault regions. However, BRBFs with the Double-X brace configurations exhibit the higher interstory drift and residual drift response under near-fault ground motions due to the formation of plastic hinges in the columns and beams at the intermediate story levels.