• Title/Summary/Keyword: Conduction Velocity

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A Study on Surface Drift Velocity in Water Waves (파랑에 의한 수표면 부유속도에 관한 연구)

  • 김태인;최한규;권혁재
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.329-339
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    • 1995
  • To clarify the surface drift velocity in gravity waves. experimental data measured in a two-dimensional wave flume were compared with theoretical values predicted by the Stokes 2nd- and 5th- order theories as well as by the conduction solution or Longuet-Hinggins (1953). Relative water depth and wave height ranged 0.040.13. For a closed flume condition, Stokes 2nd-order theory gives lower values than the experimental data, and the differences increase as both relative water depth and wave height increase. Based on the observed data of the surface drift velocities, a modified Parabolic model of the return current velocity Profile has been suggested, which is Proved to fit better to the existing experimental data of mass transport velocity profiles in a closed wave flume than the models of Longuet-Hinggins (1953) and Stokes wave theories do.

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A Study of Nerve Conduction Velocity of Normal Adults (정상성인의 신경전도속도에 관한 연구)

  • Choi, Kyoung-Chan;Hah, Jung-Sang;Byun, Yeung-Ju;Park, Choong-Suh;Yang, Chang-Heon
    • Journal of Yeungnam Medical Science
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    • v.6 no.1
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    • pp.151-163
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    • 1989
  • Nerve conduction studies help delineate the extent and distribution of the neural lesion. The nerve conduction was studied on upper(median, ulnar and radial nerves) and lower(personal, posterior tibial and sural nerves) extremities in 83 healthy subjects 23 to 66 years of age. and normal values were established(Table 1). The mean motor terminal latency (TL) were : median. 3.6(${\pm}0.6$)milliseconds ; ulnar. 2.9(${\pm}0.5$) milliseconds ; radial nerve. 2.3(${\pm}0.4$) milliseconds. Mean motor nerve conduction velocity(MNCV) along distal and proximal segments: median. 61.2(${\pm}9.1$) (W-E) and 57.8(${\pm}13.2$) (E-Ax) meters per second ; ulnar. 63.7(${\pm}9.1$) (W-E) and 50.(${\pm}10.0$) meters per second. Mean sensory nerve conduction velocity(SNCV) : median. 34.7(${\pm}6.7$) (F-W), 63.7(${\pm}7.1$) (W-E) and 62.8(${\pm}12.3$) (E-Ax)meters per second ; ulnar. 38.0(${\pm}6.7$)(F-W), 63.4(${\pm}7.5$) (W-E) and 57.0(${\pm}10.1$) (E-Ax)meters per second ; radial, 45.3(${\pm}6.8$) (F-W) and 64.2(${\pm}11.0$) (W-E) meters per second ; sural nerve, 43.4(${\pm}6.1$) meters per second. The amplitudes of action potential and H-reflex were also standardized. Mean H latency was 28.4(${\pm}3.2$) milliseconds. And. the fundamental principles, several factors altering the rate of nerve conduction and clinical application of nerve stimulation techniques were reviewed.

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The Effects of Bambusae caulis in liquamen and Bambusae concretio silicae on Blood Sugar Reduction and Improvement of Peripheral Nerve Function in Diabetic Rats Induced with Streptozotocin (죽력(竹瀝)과 천축황(天竺黃)이 Streptozotocin으로 당뇨가 유발된 백서의 혈당강하 및 말초신경기능회복에 미치는 영향)

  • Park, Soo-Gon;Bae, Kil-Joon;Lee, Ook-Jae;Kim, Seon-Jong;Jung, Min-Young
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.1
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    • pp.13-30
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    • 2014
  • Objectives This study was designed to investigate the effects of Bambusae caulis in liquamen and Bambusae concretio silicae on blood sugar reduction and improvement of peripheral nerve function in diabetic rat models. Methods Diabetic rat models induced by streptozotocin were divided into five groups. We fed experimental group I of rats basal diet and administered normal saline (3 ml, 1 time/1 day) for 6 weeks. We fed experimental group II of rats basal diet and administered Bambusae caulis in liquamen (100 mg/kg, 1 time/1 day) for 6 weeks. We fed experimental group III, IV, V of rats basal diet and administered Bambusae concretio silicae (100 mg/kg, 200 mg/kg, 400 mg/kg once a day) for 6 weeks. We investigated weight and glucose level of rats, and carried out touch test, hot plate test, sensory & motor nerve conduction velocity test and immunohistochemical study after 48 hours, 2 weeks, 4 weeks and 6 weeks. Results 1. The weight of all experimental group was gradually decreased. And glucose level was significantly decreased in the experimental group II, III, IV, V as compared with experimental group I. Especially experimental group II, IV, V were significantly decreased as compared with experimental group III. 2. In the quantitative analysis by touch test and hot plate test, mechanical pain threshold and heat pain threshold were significantly decreased in the other experimental groups as compared with experimental group I. Especially experimental group II, IV, V were significantly decreased as compared with experimental group III. 3. In the sensory and motor nerve conduction velocity test, sensory and motor nerve conduction velocity were significantly increased in the other experimental groups as compared with experimental group I. Especially experimental group II, IV, V were significantly increased as compared with experimental group III. 4. In the substance P immunohistochemical study, experimental group II, IV, V showed strong immune response in spinal cord. Conclusions Bambusae caulis in liquamen and Bambusae concretio silicae were probably useful to treat patients with diabetic peripheral neuropathy.

EFFECT OF LOW - POWER LASER IRRADIATION ON PAIN RESPONSE (저출력 레이저조사가 동통반응에 미치는 영향)

  • Kim, Sung-Kyo;Yoon, Soo-Han;Lee, Jong-Heun
    • Restorative Dentistry and Endodontics
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    • v.16 no.2
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    • pp.85-98
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    • 1991
  • The aim of this study was to investigate the effect of low - power laser used in the medical field for various purposes to suppress pain responses evoked by noxious electrical or mechanical stimuli. After both inferior alveolar nerves and the left anterior digastric muscle of cats under general anesthesia were exposed, a recording electrode for the jaw opening reflex was inserted into the anterior digastric muscle. The right inferior alveolar nerve was dissected under a surgical microscope until the response of the functional single nerve could be evoked by the electrical stimulation of the dental pulp or oral mucosa. The electrical stimulus was applied with a rectangular pulse of 10 ms duration for measuring the threshold intensity of a single nerve fiber in the inferior alveolar nerve which responds to stimulation of dental pulp and oral mucosa. Then a pulse of 1 ms duration was applied for determination of conduction velocity. A noxious mechanical stimulus to the oral mucosa was applied by clamping the receptive field with an arterial clamp. The Ga-As diodide laser(wave length, 904 nm ; frequency, 1,000 Hz) was irradiated to the prepared tooth cavity, inferior alveolar nerve and oral mucosa as a pulse wave of 2 mW for 6 minutes. This was followed by a continuous wave of 15 mW for 3 minutes. The action potential of the nerve and EMG of the digastric muscle evoked by the noxious electrical stimulus and nerve response to noxious mechanical stimulus were compared at intervals of before, immediately after, and at 5, 10, 20, 40, 60 minutes after laser irradiation. The results were as follows: The conduction velocity of the intrapulpal $A{\delta}$- nerve fiber recorded from the inferior alveolar nerve before irradiation had a mean value of $6.68{\pm}2.07m/sec$. The laser irradiation did not affect the conduction velocity of the AS - nerve fiber and did not change the threshold intensity or amplitude of the action potential either. The EMG of the digastric muscle evoked by noxious electrical stimulation to the tooth was not changed by the laser irradiation, whether in latency, threshold intensity or amplitude. The laser irradiated to the receptive field of the oral mucosa which was subjected to noxious stimuli did not affect the amplitude of the action potential or the frequency either.

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Effects of Anesthetics on Somatosensory Evoked Potentials (SEPs) in Dogs (마취제가 개의 Somatosensory Evoked Potentials (SEPs)에 미치는 영향)

  • Hong, Yeon-Jung;Jeong, Seong-Mok;Nam, Tchi-Chou
    • Journal of Veterinary Clinics
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    • v.19 no.3
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    • pp.277-282
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    • 2002
  • This study was designed to evaluate the effects of anesthetics on waveform of SEPs and to authorize possible anesthetic protocol for measurement of the somatosensory evoked potentials (SEPs). Thirteen anesthetic methods were used. The SEPs were recorded on two channels (between the 5th and 6th lumbar vertebra as the channel 1 and between the 11th and 12th thoracic vertebra as the channel 2) following stimulation of posterior tibial nerve. ID analyze SEPs wave, latency and conduction velocity were measured. Among thirteen anesthetic methods, standard SEPs waveforms were observed in dogs anesthetized with following six methods: Acepromazine + Thiepfntal Na + Isoflurane, Acepronazine + Propofol + Isoflurane, Diazepam + Xylazine, Xylazine + Ketamine, Acepromazine + Propofol infusion and Propofol infusion. Above six methods could be used with sufficient anesthetic depth. The differences of latency and conduction velocity among six groups were minimal compared to general waveform of SEPs. These results indicate that the six anesthetic methods can be used for recording SEPs in the dog. In particular, Diazepam + Xylazine and XylaBine + Ketamine as injectable anesthesia are considered more convenient than other four methods in veterinary medicine.

Development and physiological assessments of multimedia avian esophageal catheter system

  • Nakada, Kaoru;Hata, Jun-ichi
    • Journal of Multimedia Information System
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    • v.5 no.2
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    • pp.121-130
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    • 2018
  • We developed multimedia esophageal catheters for use with birds to measure and record ECG and angular velocity while anesthesized, at rest, and in flight. These catheters enable estimates of blood pressure based on readings given by an angular velocity sensor and by RR intervals of ECG affected by EMG. In our experiments, the catheters had the following characteristics: 1. Esophageal catheters offer a topological advantage with 8-dB SNR improvement due to elimination of electromyography (EMG). 2. We observed a very strong correlation between blood pressure and the angular velocity of esophageal catheter axial rotation. 3. The impulse conduction pathway (Purkinje fibers) of the cardiac ventricle has a direction opposite to that of the mammalian pathway. 4. Sympathetic nerves predominate in flight, and RR interval variations are strongly suppressed. The electrophysiological data obtained by this study provided especially the state of the avian autonomic nervous system activity, so we can suspect individual's health condition. If the change of the RR interval was small, we can perform an isolation or screening from the group that prevent the pandemics of avian influenza. This catheter shall be useful to analysis an avian autonomic system, to perform a screening, and to make a positive policy against the massive infected avian influenza.

Small-scale effects on wave propagation in curved nanobeams subjected to thermal loadings based on NSGT

  • Ibrahim Ghoytasi;Reza Naghdabadi
    • Advances in nano research
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    • v.16 no.2
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    • pp.187-200
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    • 2024
  • This study focuses on wave propagation analysis in the curved nanobeam exposed to different thermal loadings based on the Nonlocal Strain Gradient Theory (NSGT). Mechanical properties of the constitutive materials are assumed to be temperature-dependent and functionally graded. For modeling, the governing equations are derived using Hamilton's principle. Using the proposed model, the effects of small-scale, geometrical, and thermo-mechanical parameters on the dynamic behavior of the curved nanobeam are studied. A small-scale parameter, Z, is taken into account that collectively represents the strain gradient and the nonlocal parameters. When Z<1 or Z>1, the phase velocity decreases/increases, and the stiffness-softening/hardening phenomenon occurs in the curved nanobeam. Accordingly, the phase velocity depends more on the strain gradient parameter rather than the nonlocal parameter. As the arc angle increases, more variations in the phase velocity emerge in small wavenumbers. Furthermore, an increase of ∆T causes a decrease in the phase velocity, mostly in the case of uniform temperature rise rather than heat conduction. For verification, the results are compared with those available for the straight nanobeam in the previous studies. It is believed that the findings will be helpful for different applications of curved nanostructures used in nano-devices.

The simulation of electrons swarm parameter in He gas is used by Boltzman equation (볼츠만 방정식을 이용한 Helium 가스의 전자군 파라미터 시뮬레이션)

  • 송병두;하성철;김대연
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.155-158
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    • 1998
  • This paper is calculated at electron swarm simulation by Back Prolongation of Boltzmann equation for range of E/N values from 0.1~200[Td], pressure P= 1.0[Torr], temperature T=300[ 。K], the electron swarm parameter(drift velocity, longitudinal . transverse diffusion coefficients, characteristic energy, etc) in He gas is used by electron collision cross section, particularly explicate the simulation technique, and consider electrical conduction characteristic of He gas.

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Real time muscle fatigue monitoring by adaptive filtering algorithm (적응 필터링 알고리즘에 의한 근육 피로도의 실시간 측정)

  • 최영환;홍기릉;김성환
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.713-716
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    • 1987
  • A new approach to the real-time measurement of muscle fatigue by using adaptive filtering algorithm is proposed. Unlike previously reported methods, it can estimate the muscle fatigue at every sample as the EMG signal statistics change. As a result, the muscle conduction velocity ranged between 4.2-5m/s at low tension and 3-4m/s at fatigue state.

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