• The Journal of Korean Physical Therapy
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• 제17권4호
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• pp.559-567
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• 2005

The purpose of this research is to study how the stretching exercise along with heat and electric therapy can effect on Angle of Lumbar Flexion and Reduction of Pain against the Hamstring Construction Symptom that can be found in the Chronic Low Back Patients. The target of research was 28 person selected out of the patients diagnosed as Lumbar Sprain and Lumbar Syndrome, who have positive from the active test of Hamstring construction and passive test. Their age range is 20 to 60 years old, 14 male and 14 female. As a research method, simple heat and electric therapy was applied to counter part while Hamstring Stretching Exercise including simple heat and electric therapy was applied to the experimental part. After 6 weeks treatment for each part, the results of effect on Angle of Lumbar Flexion and Pain Reduction was compared and analysed on the basis of the gravity angle meter and Visual Analogue Scale (VAS). The outcome of research is as follows: 1. Angle of Lumbar Flextion increased effectively not in the conventional counter group but the experimental group to which Hamstring Stretching was applied simultaneously. 2. remarkable effect was shown in the experimental part applied Hamstring Stretching. Consequently from the results of this study, we could find out the fact that the therapy combined preserve treatment and hamstring stretching not only produced increasing Lumbar Flexion Angle but also was more effective on reducing pain of the patients according to it than the conventional or preserve therapy.

• 대한물리치료과학회지
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• 제9권4호
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• pp.35-44
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• 2002

The purpose of this study was to compare the effect of heat therapy, stretching exercise and to verify which method was most effective for lumbar flexibility improvement. Subjects were 20 apparantly healthy person(male10, female10) who did not have any medical problem. They were randomly divided and assigned into 2 groups: heat therapy, stretching exercise. For testing flexibility, trunk flexion, bunk extension, and Schober-test were performed. Pre-test was done prior to the each group's treatment. Test was done at 2nd week, 4th week and 6th week. There were no significant difference in improvement of trunk flexion and trunk extension after 6 weeks treatment among 2 methods. However in all 2 groups, there were statically significant improvement in flexibility as time go on. The rate of improvement was highest at 2nd week, while this was attenuated afterwards. The Schober-test score changed significantly from pre-test to the mid-test and to the post-test, while there were no significant difference among 2 methods of treatment. With the results above, it was concluded that heat therapy, stretching-exercise were all effective for improving flexibility without any significant priorities.

• 한국재료학회지
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• 제9권1호
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• pp.30-34
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• 1999

A polyacrylonitrile(PAN)-based carbon fiber tow was heat-treated by directly passing electric current through the tow. The effects of the stretching stress applied during high temperature heat-treatment of PAN-based carbon fibers were investigated by measuring the electric resistance changes taking place during the internal resistance heating. The structure parameters characterizing the stacks of carbon layer, such as interlayer spacing, sizes and orientation of the carbon fibers heat-treated with hot-stretching were evaluated as a function of surface temperature of tow during heat treatment in the range of $1000~2400^{\circ}C$. Though the layer extent in the fiber axis direction depends strongly on the electric resistance, the changes in a crystallite parameter is independent of the longitudinal strain.

• The Journal of Korean Physical Therapy
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• 제31권1호
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• pp.56-61
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• 2019

Purpose: The spasticity of stroke patients decreases the ankle range of motion and increases the gastrocnemius muscle tone. This study examined the effects of stretching exercise and far infrared irradiation on the ankle function in stroke patients with spasticity. Methods: This study was conducted on 20 stroke patients admitted to Jesaeng General Hospital, who were divided into a study group (stretching exercise with far infrared) and control group (stretching exercise only). The dorsiflexion range of motion was measured using a smartphone and the medial gastrocnemius muscle tone and stiffness were measured using a Myoton pro. Results: With the exception of the non-paretic gastrocnemius muscle tone in the control group, the medial gastrocnemius muscle tone and stiffness decreased significantly in both groups. In both groups, the dorsiflexion range of motion increased significantly. In addition, the experimental group had a significantly higher dorsiflexion range of motion than the control group. On the other hand, there was no significant difference between the two groups in terms of the medial gastrocnemius muscle tone and stiffness. Conclusion: For stroke patients with spasticity, stretching exercises increased the ankle's range of motion and decreased the gastrocnemius muscle tone. The addition of heat therapy further increased the ankle's range of motion. On the other hand, as the sample size was small, future studies should include more subjects.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제18권3호
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• pp.245-256
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• 2014

This work is focused on the boundary layer and heat transfer characteristics of hydromagnetic flow over a stretching sheet with variable thickness. Steady, two dimensional, nonlinear, laminar flow of an incompressible, viscous and electrically conducting fluid over a stretching sheet with variable thickness and power law velocity in the presence of variable magnetic field and variable temperature is considered. Governing equations of the problem are converted into ordinary differential equations utilizing similarity transformations. The resulting non-linear differential equations are solved numerically by utilizing Nachtsheim-Swigert shooting iterative scheme for satisfaction of asymptotic boundary conditions along with fourth order Runge-Kutta integration method. Numerical computations are carried out for various values of the physical parameters and the effects over the velocity and temperature are analyzed. Numerical values of dimensionless skin friction coefficient and non-dimensional rate of heat transfer are also obtained.

• Kyungpook Mathematical Journal
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• 제60권4호
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• pp.853-867
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• 2020

The aim of this study was to analyze the momentum and heat transfer of a rotating nanofluid with conducting spherical dust particles. The fluid flows over a stretching surface under the influence of an external magnetic field. By applying similarity transformations, the governing partial differential equations were trans-formed into nonlinear coupled ordinary differential equations. These equations were solved with the built-in function bvp4c in MATLAB. Moreover, the effects of the rotation parameter ω, magnetic field parameter M, mass concentration of the dust particles α, and volume fraction of the nano particles 𝜙, on the velocity and temperature profiles of the fluid and dust particles were considered. The results agree well with those in published papers. According to the result the hikes in the rotation parameter ω decrease the local Nusselt number, and the increasing volume fraction of the nano particles 𝜙 increases the local Nusselt number. Moreover the friction factor along the x and y axes increases with increasing volume fraction of the nano particles 𝜙.

• 한국잠사곤충학회지
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• 제15권1호
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• pp.31-35
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• 1973

생사의 항장성에 관여하는 기본적인 성질은 강력 신도 및 탄성이다. 그리고 이들 3자간의 적당한 조화가 생사의 특성을 발현한다. 또 생사의 이러한 역학적 거동은 이를 구성하고 있는 견사가 지배하는 것이다. 이러한 견지에서 저자는 견사의 신장변형과정에서의 항장성에 관하여 연구하고 다음과 같은 결과를 얻었다. 1. 견층별견사의 인장강력은 내층견사가 외층 및 중층견사보다 높았다. 2. 견건조과정에 있어서 견층 sericin의 습열변성은 견사의 인장강력을 변화시킨다. 3. 신장과정에 있어서 견사의 변형량이 증가하면 elasticity index가 감소한다. 4. 다습열에 의한 견층 sericin의 변성은 견사의 elasticity 를 감소시킨다.

• Composites Research
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• 제26권2호
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• pp.123-128
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• 2013

PVDF(polyvinylidene fluoride) 섬유는 습식방사방법을 적용하여 제조하였다. PVDF 분자 내 압전 특성과 밀접한 관련을 갖는 ${\beta}$형태의 결정 함량을 높이기 위하여, 본 연구에서는 습식방사 된 섬유에 1단계 연신, 2단계 어닐링 공정으로 구성하여 후 처리를 도입하였다. 후 처리는 PVDF 고분자의 유리전이 온도($T_g$)와 용융온도($T_m$) 사이의 온도범위에서 진행하여, 최대의 ${\beta}$형태 결정을 생성 할 수 있는 열처리 조건을 최적화 하였다. 제조된 PVDF 섬유 내 분자 배향 특성과 결정 구조를 확인하기 위하여 적외선 분광 광도계(FT-IR)와 X선 회절 분석기(XRD)를 이용하여 분석하였으며, 전자현미경(SEM)을 통하여 섬유의 표면을 관찰하여 섬유의 평균직경을 확인하였다. 분석 결과, 후 처리 공정이 PVDF 결정 구조의 영향을 미치며, ${\beta}$형태의 결정 비율을 증가시킨다는 것을 확인하였다. 더불어 ${\beta}$형태 결정 향상으로 인해 기계적 강도가 증가되었으며, 압전 특성 향상까지 기대할 수 있었다.

• Journal of Magnetics
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• 제21권1호
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• pp.153-158
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• 2016

This paper aims to discuss the Non Darcy boundary layer flow of non-conducting viscous fluid with magnetic ferroparticles over a permeable linearly stretching surface with ohmic dissipation and mixed convective heat transfer. A magnetic dipole is applied "a" distance below the surface of stretching sheet. The governing equations are modeled. Similarity transformation is used to convert the system of partial differential equations to a system of non-linear but ordinary differential equations. The ODEs are solved numerically. The effects of sundry parameters on the flow properties like velocity, pressure, skin-friction coefficient and Nusselt number are presented. It is deduced the frictional resistance of Lorentz force decreases with stronger electric field and the trend reverses for temperature. Skin friction coefficient increase with increase in ferromagnetic interaction parameter. Whereas, Nusselt number decrease.

• 한국결정성장학회지
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• 제9권1호
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• pp.64-69
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• 1999

PANrP 탄소섬유의 고온연신에서의 변형 거동을 검토하기 위해서, 일정 하중하에서 내부저항 가열법에 의해 $1200^{\circ}C$부터 $2200^{\circ}C$까지 열처리 온도를 변화시키며 섬유의 strain 변화를 측정하였다. 부하된 응력이 증가함에 따라서 strain 변화가 크게 발생하며 또한 열처리 온도 약 $1700^{\circ}C$를 경계로 해서 그 온도 이상과 이하 사이에는 큰 차이를 보였다. 각 응력에 있어서의 strain 속도 변화로부터 얻어진 활성화 에너지는 70 MPa 및 322 MPa에 대하여 각각 67.46 및 52.27 kJ/mol로써, 큰 응력의 경우가 작은 응력을 부하하는 것 보다 섬유구조 발달에 있어서 더욱 효과적이라는 것을 알았다.