• Title/Summary/Keyword: Conduction

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Electrical Conduction Mechanisms of $RuO_2$ Based Thick Film Resistor ($RuO_2$계 후막저항체의 전기전도기구)

  • 구본급;김호기
    • Journal of the Korean Ceramic Society
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    • v.31 no.12
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    • pp.1529-1535
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    • 1994
  • Electrical conduction mechanisms of RuO2-based thick film resistors were investigated with frequency depandence on AC conductivity. Electrical conduction mechanisms of lower resistivity system (100{{{{ OMEGA }}/sq) sintered at 600~90$0^{\circ}C$ were all metallic conduction mechanism. In case of higher resistivity (10K{{{{ OMEGA }}/sq) system, the electrical conduction mechanisms were very depenent on sintering temperature. When sintering temperature was $600^{\circ}C$, the electrical conduction mechamism was ionic, and as increasing the sintering temperature, the electrical conduction mechanism was changed from ionic to hopping conduction mechanism.

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The Electrical Conduction Characteristics of Silicone oils due to Viscosity Variation (점도변화에 따른 실리콘유의 전기전도특성)

  • 조경순;홍진웅;신종열;이충호;이수원
    • Electrical & Electronic Materials
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    • v.10 no.9
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    • pp.945-951
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    • 1997
  • Inorder to investigated electrical conduction characteristics of silicone oils due to viscosity variation we studied the electrical conduction properties at temperature range of 10~110[$^{\circ}C$] and electrical field from 1 to 1.33$\times$10$^4$[V/cm] The viscosity of used specimens was low viscous(1, 2, 5[cSt]) silicone oils. It was shown the ohmic conduction characteristics in low temperature and low field by Ion dipole and humidity included specimen. And we known the conduction mechanism due to electron injection by Schottky's effect in the high temperature an d high field region.

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Medial Plantar Sensory Nerve Conduction Studies in Diabetics: Comparision of Three Different Methods (당뇨병 환자에서의 안쪽 발바닥 감각신경의 신경전도검사: 세 가지 다른 방법의 비교)

  • Kwon, Hyuk-Hwan;Lee, Dong-Kuck;Seok, Jung-Im;Han, Woo-Ho
    • Annals of Clinical Neurophysiology
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    • v.12 no.1
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    • pp.16-20
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    • 2010
  • Background: The medial plantar nerve (MPN) is a distal branch of the posterior tibial nerve, and various methods of nerve conduction study for MPN have been introduced so far. Hemmi et al described a new method (Hemmi's method) for recording medial plantar sensory nerve action potentials (SNAPs), which is considered as a simple and reliable method for measuring medial plantar SNAPs. This study was aimed to establish the normal values for the MPN conduction study among Koreans and to compare the sensitivities of three different methods for MPN conduction study (Hemmi, Oh, and Saeed's method) in detecting evidence of peripheral neuropathy among diabetic patients. Methods: In 27 healthy subjects, MPN conduction study using Hemmi's method was performed and normal values were calculated. In 54 diabetic patients who showed normal routine nerve conduction studies, three different methods for MPN conduction study were performed and diagnostic sensitivity of each method were compared. Results: In normal subjects, the mean medial plantar SNAP amplitude and conduction velocities measured by Hemmi's method were $4.3{\pm}1.0$ uV and $38.3{\pm}6.8$ m/s respectively. Among 54 patients with diabetes who showed normal routine nerve conduction studies, medial plantar SNAP was not obtainable in 28, 31, and 6 patients by Hemmi, Oh and Saeed's method respectively. Conclusions: In terms of the diagnostic sensitivity for detecting diabetic neuropathy, there had been no significant statistical difference between three different methods. Our study suggested that MPN conduction study using Hemmi's method is simple and useful screening test for early diabetic neuropathy, and is comparable with Oh's method.

ZVT single phase power factor correction circuit with low conduction loss and low cost (저도통 손실, 저가의 ZVT 단상 역률 보상 회로)

  • Baek, J.W.;Cho, J.G.;Kim, W.H.;Rim, G.H.;Song, D.I.;Kwon, S.G.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.255-258
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    • 1996
  • A new low conduction loss, low cost zero-voltage-transition power factor correction circuit(PFC) is presented. Conventional PFC which consists of a bridge diode and a boost converter(one switch) always has three semiconductor conduction drops. Two switch type PFCs reduces conduction loss by reducing one conduction drop but the cost is increased because of increased number of active switches. The proposed PFC reduces conduction loss with one switch, which allows low cost. Conduction loss improvement is a little bit less than that of two switch type, but very close up. Operation and features are comparatively illustrated and verified by simulation and experimental results of 1 kW laboratory prototype.

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Effects of Caffeine on Nerve Conduction Velocity (카페인이 신경전도속도에 미치는 영향)

  • Kang, Yun-Jung
    • Journal of Convergence for Information Technology
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    • v.10 no.3
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    • pp.195-199
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    • 2020
  • This study examined the effect of the nervous-system-stimulating caffeine on the nerve conduction velocity. The purpose of this study is to investigate the effect of caffeine that stimulates the nervous system on nerve conduction test. Although both measurement intervals did not show statistically significant differences when comparing the pre- and post-NCV values within the control and individual experimental groups, it was found that the nerve conductivity in the Axilla-Above Elbow section increased significantly after caffeine intake for the experimental group. Caffeine intake, which has increased the nerve conduction velocity (NCV), was determined to play roles in improving motor skills, muscle strength and nerve performance by temporarily increasing the nerve conduction velocity. Through this study, we learned that caffeine has an influence on the peripheral nervous system as it helps to improve the nerve conduction velocity. upon an appropriate amount of caffeine intake. We hope that these results will help develop treatment and diagnostic methods for patients with nerve dysfunction and myofunctional disorders.

A Study of the Heat Conduction Phenomena with a Phase Lag of Heat Flux (열유속 상지연이 존재하는 열전도 현상에 대한 연구)

  • Jin, Chang-Fu;Kim, Kyung-Kun;Chung, Han-Shik;Jeong, Hyo-Min;Choi, Du-Yeol;Choi, Soon-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.5
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    • pp.684-690
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    • 2008
  • In most engineering applications related with the heat conduction phenomena, a conventional Fourier heat conduction equation has been successfully applied and it has supplied quite reasonable results. However, it is well known that the Fourier heat conduction equation is failed in the application to the extremely small space and short time, in other words, a nano-scale system and a pico-second time. In this study, non-Fourier effect was evaluated in the heat conduction by considering the concept of a phase lag model. The results show the existence of a heat wave, which means that the heat is transferred with a finite speed while an infinite speed of heat transfer is assumed in the conventional Fourier heat conduction. In addition, the copper and the gold are tested to evaluate the phase lag time between the heat flux and the temperature gradient. The results show that the gold has the heat wave speed faster than that of the copper consistent with the prediction based on an actual experiment.

Switching conduction characteristics of PI LB Film in MIM junctions (Polyimide(PI)LB막의 MIM구조 소자내에서의 switching전도특성)

  • ;;Mitsumasa Iwamoto
    • Electrical & Electronic Materials
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    • v.8 no.2
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    • pp.176-183
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    • 1995
  • The present work is concerned with the switching conduction characteristics of PI LB films in metal insulator metal sandwiches. By applying various DC voltage bias to MIM junctions, conduction characteristics of junctions can be changed between the high-voltage low-current(off) condition, the low-voltage high-current (on) condition and the medium(mid) condition. Switching conduction characteristics can be also observed in MIM junctions employing some aromatic compounds as insulators. Switching conduction characteristics is assumed to be owing to the existence of aromatic rings, space charge in films, impurities on metal-insulator interface, and difference in work functions of base and top electrodes metal. To study the conduction process of on, off, and mid conductions, we measured I-V, d$^{2}$V/d I$^{2}$-V characteristics of junctions with several different top electrodes under various temperatures. Small conductance changes of junctions can be measured by observing the second derivative, d$^{2}$V/dI$^{2}$, of I-V curve. A dynamical technique is used to get the second derivatives. That is, a finite modulation of the current is applied to the junctions and the second harmonic of the voltage is detected.

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Conduction Mechanism of Charge Carriers in Electrodes and Design Factors for the Improvement of Charge Conduction in Li-ion Batteries

  • Akhtar, Sophia;Lee, Wontae;Kim, Minji;Park, Min-Sik;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
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    • v.12 no.1
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    • pp.1-20
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    • 2021
  • In-depth knowledge of electrode processes is crucial for determining the electrochemical performance of lithium-ion batteries (LIBs). In particular, the conduction mechanisms of charged species in the electrodes, such as lithium ions (Li+) and electrons, are directly correlated with the performance of the battery because the overall reaction is dependent on the charge transport behavior in the electrodes. Therefore, it is necessary to understand the different electrochemical processes occurring in electrodes in order to elucidate the charge conduction phenomenon. Thus, it is essential to conduct fundamental studies on electrochemical processes to resolve the technical challenges and issues arising during the ionic and electronic conduction. Furthermore, it is also necessary to understand the transport of charged species as well as the predominant factors affecting their transport in electrodes. Based on such in-depth studies, potential approaches can be introduced to enhance the mobility of charged entities, thereby achieving superior battery performances. A clear understanding of the conduction mechanism inside electrodes can help overcome challenges associated with the rapid movement of charged species and provide a practical guideline for the development of advanced materials suitable for high-performance LIBs.

Clinical Study of Bell's Palsy with DITI and Nerve Conduction Test(EN0G and EMG) (DITI 및 전기신경전도검사(EN0G 및 EMG)를 이용한 구안와사(Bell's palsy) 환자에 대한 임상적 고찰)

  • Kim, Jin-man;Hong, Chul-hee;Du, In-sun;Hwang, Chung-yeon;Kim, Nam-kwen;Park, Min-chul;Lee, Sang-kwan;Jung, Sang-su;Yoon, Jun-chul
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.16 no.2
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    • pp.189-211
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    • 2003
  • The clinical data and thermographic imaging were analyzed on the 38 cases of Bell's palsy who were treated admission in the Oriental Medicine Hospital of Wonkwang University from January 2002 to May 2003. 38 patients with Bell's palsy were within one week after the onset of the paralysis, and thermal type in the DITI were hypo or hyper generally. Nerve conduction test(ENOG and EMG) examined in two weeks after onset. We studied interaction effect between thermal type and paralysis grade on admission day. We studied each main effect ; paralysis grade on admission day - nerve conduction test, nerve conduction test - thermal type, thermal type - paralysis grade after 4 weeks, paralysis grade on admission day - paralysis grade after 4 weeks, sasang constitution - nerve conduction test. The following results were obtained that interaction effect between thermal type and paralysis grade on admission day showed no significance, each main effect ; paralysis grade on admission day - nerve conduction test, paralysis grade on admission day - paralysis grade after 4 weeks, showed significance, each main effect ; nerve conduction test - thermal type, thermal type - paralysis grade after 4 weeks, sasang constitution - nerve conduction test, showed no significance.

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Thermal analysis of the conduction cooling system for HTS SMES system of 600 kJ class (600kJ급 SMES용 전도냉각시스템 열해석)

  • Hong, Yong-Ju;Yeom, Han-Kil;Park, Seong-Je;Kim, Hyo-Bong;Koh, Deuk-Yong
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.1959-1963
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    • 2007
  • SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution.

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