• Title/Summary/Keyword: Physical relaxation

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Dielectric Relaxation Properties of Organic Ultra Thin Films for Nanotechnology (나노기술을 위한 유기초박막의 유전완화특성)

  • Cho, Su-Young;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05c
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    • pp.9-13
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    • 2004
  • In this paper, evaluation of physical properties about dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DLPC, DMPC using pressure stimulus. As a result, the changed surface pressure, displacement current and the transition forms of dipole moment of phospolipid monomolecular in area per molecular by pressure stimulus were conformed well. It was known that the monolayers by linear relationship for decision of dielectric relaxation time between compressure speed and molecule area By according to the linear relationship relation get that frictional constant, DLPC was $1.89{\times}10^{-19}$[Js] and DMPC was $0.722{\times}10^{-19}$[Js]. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area.

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A Study on the Electrical Physical Properties of Organic Thin Films for Manufacture in Power Device (전력용 소자 제작을 위한 유기박막 전기물성에 관한 연구)

  • Cho, Su-Young;Kim, Young-Keun;Choi, Young-Il;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05c
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    • pp.37-41
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    • 2004
  • In this paper, evaluation of physical properties about dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DLPC, DMPC using pressure stimulus. As a result, the changed surface pressure, displacement current and the transition forms of dipole moment of phospolipid monomolecular in area per molecular by pressure stimulus were conformed well. It was known that the monolayers by linear relationship for decision of dielectric relaxation time between compressure speed and molecule area By according to the linear relationship relation get that frictional constant, DLPC was $1.89{\times}10^{-19}$ [Js] and DMPC was $0.722{\times}10^{-19}$[Js]. lt is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area.

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Effects of PNF Program on Neck Pain, Cervical Range of Motion, Pressure Pain, and Cervical Flexion-Relaxation Ratio in VDT Worker: a Case Study (VDT 직업 종사자의 목 통증, 목뼈 운동범위, 누름통증, 목뼈 굽힘-이완 비율에 PNF 프로그램이 미치는 영향: 증례보고)

  • Kim, Yong-Hun;Jung, Ju-Hyeon
    • PNF and Movement
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    • v.13 no.4
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    • pp.197-202
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    • 2015
  • Purpose: This study aimed to examine the effects of a proprioceptive neuromuscular facilitation (PNF) program on neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in a visual display terminal (VDT) worker. Methods: We recruited a 33-year-old VDT worker diagnosed with chronic VDT syndrome. The subject was treated using a PNF program for 20 minutes a day, three times a week for six weeks. All evaluations were performed every two weeks on the first test day. Results: The PNF program resulted in a significant improvement in the subject's neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio after six weeks, in comparison to the subject's condition before treatment. Conclusion: The PNF program can be used effectively to improve neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in visual display terminal (VDT) workers.

Can Myofascial Release Techniques Reduce Stress Hormones in the Subject of Short Hamstring Syndrome? A Pilot Study

  • Cho, Sunghak
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.4
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    • pp.2237-2243
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    • 2020
  • Background: The myofascial release technique is known to be an effective technique for increasing posterior fascia flexibility in short hamstring syndrome (SHS) subjects. But therapeutic mechanism of myofascial relaxation remains unclear. Recently, the theory of autonomic nervous system domination has been raised, however, a proper study to test the theory has not been conducted. Objectives: To investigate whether the application of the myofascial release technique can induce changes in the autonomic nervous system and affect the secretion of stress hormones and myofascial relaxation. Design: Quasi-experimental study. Methods: Twenty-four subjects with SHS were randomly divided into two groups. In the experimental group, the suboccipital muscle inhibition (SMI) technique was applied to the subjects for 4 min in supine position, and in the control group, the subjects were lying in the supine position only. A forward flexion distance (FFD) was conducted, blood pressure, heart rate, and cortisol levels were measured before and after the intervention and 30 min after intervention to determine myofascial relaxation and stress hormone levels. The evaluation was conducted separately in blind by an evaluator. Results: A FFD decreased in the experimental group, no change in cortisol was observed. On the contrary, a decrease in cortisol appeared in the control group after 30 minutes. Conclusion: The myofascial release technique is an effective treatment to increase the range of motion through posterior superior myofascial chain, but there is no evidence that myofascial release technique can control the autonomic nervous system.

Practice in Relaxation Techniques (이완요법의 실제)

  • Joe, Sook-Haeng
    • Korean Journal of Psychosomatic Medicine
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    • v.9 no.1
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    • pp.93-102
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    • 2001
  • The relaxation response is a state of profound rest, creates physiological responses directly opposite to the stress response. The relaxation response can be used to counteract the harmful effects of stress. The relaxation response can be elicited by a number of techniques such as diaphragmatic breathing, meditation, progressive muscle relaxation, autogenic training, biofeedback, etc. These relaxation methods in any mental or physical conditions associated with distress and even in normal people have useful benefits for stress control and health enhancement. These relaxation techniques are but one part of a comprehensive stress management program, through regular and continuous practice appropriate for each person, they will make an effective role in stress management. In this review, author reviewed how to practically use meditation, progressive muscle relaxation and autogenic training, in more detail. In the treatment of various stress-related disease, especially in psychiatric disorders, the relaxation technique may be a useful complement to conventional treatment and serves as an intervention between stress and disease.

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Dielectric properties of 70/30 mol% P(VDF-TrFE) copolymer thin films with freqeuncy (70/30 mol% P(VDF-TrFE) 공중합체 박막의 주팍수에 따른 유전특성)

  • 윤종현;정무영;박수홍;임응춘;이상희;박상현;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.470-473
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    • 2001
  • In this study, 70/30 mol% P(VDF-TrFE) copolymer thin films were prepared by physical vapor deposition, and dielectric properties with frequency were investigated. From results of TA(Thermal Analysis), the Curie transition temperature and melting temperature were observed at 118.8$^{\circ}C$ and 146$^{\circ}C$, respectively. Therefore, while thin films were prepared, the substrate temperature was varied from 30$^{\circ}C$ to 90$^{\circ}C$. The dielectric constant decreased with increasing frequency. At measuring frequency of 1kHz, the relative dielectric constant increased from 3.643 to 23.998 with increasing substrate temperature from 30$^{\circ}C$ to 90$^{\circ}C$. As a result of dielectric loss factor, ${\alpha}$-relaxation and ${\beta}$-relaxation were observed near at 100Hz and 1MHz, respectively. And the magnitude of ${\alpha}$-relaxation decreased and that of ${\beta}$-relaxation increased with increasing substrate temperature.

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Relaxation Characteristic of the Disordered Lead Scandium Niobate

  • Kim, Yeon Jung
    • Applied Science and Convergence Technology
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    • v.24 no.3
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    • pp.47-52
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    • 2015
  • The correlation between admittance and dielectric spectroscopy of dielectric relaxation in lead scandium noibate, have been investigated. Lead scandium niobate, with composition $PbSc_{0.5}Nb_{0.5}O_3$, was prepared by conventional solid state synthesis. Conductance Y'(G), susceptance Y"(B) and capacitance C of lead scandium niobate as a function of frequency and temperature were measured. From the temperature-dependence of RLC circuit, insight into physical significance of the dielectric properties of lead scandium niobate is obtained. The relative strong frequency dependent of dielectric properties in lead scandium niobate is observed, and the phase transition occurred at a broad temperature region. Also, the value of critical exponent ${\gamma}$=1.6 showed on heating process. The long relaxation times part enlarged diffuse by conductivity effects with increasing temperature, and the ordering between $Sc^{3+}$ and $Nb^{5+}$ in PSN influences complex admittance and dielectric properties. Confirmed the typical characteristic of lead-type relaxor in the Raman spectra of lead scandium niobate and major ranges are between 400 and $900cm^{-1}$.

Computational Study on the Heat Transfer Prediction Hypersonic Flows (극초음속 유동의 열전달 예측에 관한 수치해석적 연구)

  • Nagdewe, Suryakant;Kim, H.D.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.27-30
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    • 2007
  • In recent years, scientific community has found renewed interest in hypersonic flight research. These hypersonic vehicles undergo severe aero-thermal environments during their flight regimes. One of the most important topics of research in hypersonic aerodynamics is to find a reasonable way of calculating either the surface temperature or the heat flux to surface when its temperature is held fixed. This requires modeling of physical and chemical processes. Hyperbolic system of equations with stiff relaxation method are being identified in recent literature as a novel method of predicting long time behavior of systems such as gas at high temperatures. In present work, Energy Relaxation Method (ERM) has been considered to simulate the real gas flow over a 2-D cylinder. Present heat flux results over the cylinder compared well with the experiment. Thus, real gas effects in hypersonic flows can be modeled through energy relaxation method.

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Physiological characterization of mechanism on UV light-induced photorelaxation in isolated rat aorta (쥐의 적출 대동맥에 자외선 조사로 유발된 photorelaxation 기작의 생리학적 특성)

  • Lee Han-Ki;Hong Yong-geun;Kim Kyung
    • The Journal of Korean Physical Therapy
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    • v.15 no.2
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    • pp.146-156
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    • 2003
  • Isolated rat thoracic aorta which is pharmacologically precontracted by phenylephrine induces photorelaxation when exposed to long wave length UV-light. The aim of the present study was to characterize the mechanism of UV-light induced by photorelaxation in the rat aorta. 1. UV light relaxed both endothelium-intact and -denuded rat aortic rings contracted by phenylephrine. The magnitude of relaxation on UV light was dependent on the exposure time and slightly greatly in endothelium-denuded rings than in endothelium-intact preparations. 2. L-NAME (10 nM - 100 $\mu$M) but not D-NAME completely inhibited the photorelaxation in a concentration dependent manner. 3. The UV-induced relaxation was inhibited by methylene blue (1 - 100 uM), and verapamil (100 nM), and removal of extracellular $Ca^{2+}$. In contrast, UV-light induced photorelaxation was potentiated by $N^{w}$-nitro-L-arginine (L-NNA) treatment. These results suggest that UV light-induced photorelaxation may be due to nitric oxide from exogenously administered L-arginine as well as endogenous nitric oxide donors such as amino acid and arginine derivatives

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Effect of 1Hz Motor Nerve Electrical Stimulation on Joint Range of Motion

  • Jong Ho Kang
    • Physical Therapy Rehabilitation Science
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    • v.11 no.4
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    • pp.409-413
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    • 2022
  • Objective: This study aims to compare the range of motion of the joints by applying the contraction and relaxation techniques used in manual therapy as electrical stimulation treatment. Based on this, we would like to propose the possibility of using motor nerve electrical stimulation therapy for musculoskeletal physical therapy. Design: Single-arm interventional study Methods: Active and passive straight leg raising tests were performed on 20 healthy men and women in their 20s to measure the angle of hip joint flexion. Then, the electrical stimulation time was set to 10 seconds and 5 seconds of rest, and motor nerve electrical stimulation of 1 Hz was applied with the maximum strength that could withstand the hamstring muscles for 10 minutes. After electrical stimulation, straight leg raising tests again to confirm the range of motion of the hip joint flexion. Results: As a result of this study, it was confirmed that the joint range of motion was significantly improved for both active and passive straight leg raising tests after application of motor nerve electrical stimulation(p<.05). Conclusions: With a strong electrical stimulation treatment of 1 Hz, the effect similar to the contraction and relaxation technique used in manual therapy was confirmed through the joint range of motion. In the future, motor nerve electrical stimulation therapy can be used for musculoskeletal physical therapy to provide a new approach for patients with reduced pain and joint range of motion due to muscle tension.