• Title/Summary/Keyword: Strain relaxation

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Analysis of Osteopathic Manipulation and Study on Relationship with Chuna Manual Therapy for Meridian Sinew System (정골의학적(Osteopathic) 수기요법 분석 및 경근추나와의 관련성 연구)

  • Kweon, Jeong-Ju;Lim, Hyung-Ho;Song, Yun-Kyung
    • Journal of Korean Medicine Rehabilitation
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    • v.21 no.2
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    • pp.171-188
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    • 2011
  • Objectives : The aim of this study is to analyze the actual investigation and classification of osteopathic manipulation by investigation of the various literature of the inside and outside of the country, and to present the application plan of osteopathy in chuna manual therapy for meridian sinew system. Methods : I referred to the domestic and foreign books about osteopathy and chiropractic. In order to investigate domestic dissertations, I searched 4 Korean medical databases and 4 Korean medical journals of osteopathy. Search terms used were osteopathy, osteopathic, fascia, proprioreceptor, mechanoreceptor, muscle spindle, golgi tendon organ, osteopathic manipulation technics. And I classified all the searched studies into principle and region and etc. In order to investigate foreign dissertations, I search 'NCBI pubmed'. Search terms used were osteopathy, osteopathic technique, osteopathic manipulative technique. Results : 1. Osteopathy do not regard the systems which compose the human body in individual territory, but regard whole. It is diagnosis, prevention and medicine which treats 2. Osteopathic manipulation techniques are classified into direct techniques, indirect techniques, and compound techniques. 3. Osteopathic manipulation techniques are classified into fascia, muscle, ligament-joint in applied region. 4. I could search clinical cases in domestic and foreign study. I found cases about myofascial release technique(MFR), postisometric relaxation(PIR), proprioceptive neuromuscular fascilitation(PNF), muscle energy technique(MET), joint mobilization in domestic studies, and strain-counterstrain technique(SCS), MET, AK in foreign studies. Conclusions : Osteopathic manipulation techniques can be used in diagnosis and treatment of meridian muscle theory, because osteopathy and the oriental medicine have many similarities in theoretical background. So osteopathic manipulation technique can be useful in oriental medicine treatment techniques.

Peridynamic Modeling for Crack Propagation Analysis of Materials (페리다이나믹 이론 모델을 이용한 재료의 균열 진전 해석)

  • Chung, Won-Jun;Oterkus, Erkan;Lee, Jae-Myung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.2
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    • pp.105-114
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    • 2018
  • In this paper, the computer simulations are carried out by using the peridynamic theory model with various conditions including quasi-static loads, dynamic loads and crack propagation, branching crack pattern and isotropic materials, orthotropic materials. Three examples, a plate with a hole under quasi-static loading, a plate with a pre-existing crack under dynamic loading and a lamina with a pre-existing crack under quasi-static loading are analyzed by computational simulations. In order to simulate the quasi-static load, an adaptive dynamic relaxation technique is used. In the orthotropic material analysis, a homogenization method is used considering the strain energy density ratio between the classical continuum mechanics and the peridynamic. As a result, crack propagation and branching cracks are observed successfully and the direction and initiation of the crack are also captured within the peridynamic modeling. In case of applying peridynamic used homogenization method to a relatively complicated orthotropic material, it is also verified by comparing with experimental results.

TIME-DEPENDENT FRACTURE OF ARTICULAR CARTILAGE: PART 1 - THEORY & VALIDATION

  • Mun, M.S.;Lewis, J.L.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.27-33
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    • 1995
  • A time-dependent large deformation fracture theory is developed for application to soft biological tissues. The theory uses the quasilinear viscoelastic theory of Fung, and particularizes it to constitutive assumptions on polyvinyl-chloride (PVC) (Part I) and cartilage (Part II). This constitutive theory is used in a general viscoelastic theory by Christensen and Naghdi and an energy balance to develop an expression for the fracture toughness of the materials. Experimental methods are developed for measuring the required constitutive parameters and fracture data for the materials. Elastic stress and reduced relaxation functions were determined using tensile and shear tests at high loading rates with rise times of 25-30 msec, and test times of 150 sec. The developed method was validated, using an engineering material, PVC to separate the error in the testing method from the inherent variation of the biological tissues. It was found that the the proposed constitutive modeling can predict the nonlinear stress-strain and the time-dependent behavior of the material. As an approximation method, a pseudo-elastic theory using the J-integral concept, assuming that the material is a time-independent large deformation elastic material, was also developed and compared with the time-dependent fracture theory. For PVC. the predicted fracture toughness is $1.2{\pm}0.41$ and $1.5{\pm}0.23\;kN/m$ for the time-dependent theory and the pseudo-elastic theory, respectively. The methods should be of value in quantifying fracture properties of soft biological tissues. In Part II, an application of the developed method to a biological soft tissue was made by using bovine humeral articular cartilage.

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A Study of Dopant Distribution in SiGe Using Ion Implantation and Thermal Annealing (SiGe에 이온 주입과 열처리에 의한 불순물 분포의 연구)

  • Jung, Won-Chae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.6
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    • pp.377-385
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    • 2018
  • For the investigation of dopant profiles in implanted $Si_{1-x}Ge_x$, the implanted B and As profiles are measured using SIMS (secondary ion mass spectrometry). The fundamental ion-solid interactions of implantation in $Si_{1-x}Ge_x$ are discussed and explained using SRIM, UT-marlowe, and T-dyn programs. The annealed simulation profiles are also analyzed and compared with experimental data. In comparison with the SIMS data, the boron simulation results show 8% deviations of $R_p$ and 1.8% deviations of ${\Delta}R_p$ owing to relatively small lattice strain and relaxation on the sample surface. In comparison with the SIMS data, the simulation results show 4.7% deviations of $R_p$ and 8.1% deviations of ${\Delta}R_p$ in the arsenic implanted $Si_{0.2}Ge_{0.8}$ layer and 8.5% deviations of $R_p$ and 38% deviations of ${\Delta}R_p$ in the $Si_{0.5}Ge_{0.5}$ layer. An analytical method for obtaining the dopant profile is proposed and also compared with experimental and simulation data herein. For the high-speed CMOSFET (complementary metal oxide semiconductor field effect transistor) and HBT (heterojunction bipolar transistor), the study of dopant profiles in the $Si_{1-x}Ge_x$ layer becomes more important for accurate device scaling and fabrication technologies.

Load Transfer Test for Re-tensioning Post-Tension Kit for Prestressed Concrete (프리스트레스트 콘크리트 부재용 재긴장 정착구 하중전달시험)

  • Hur, Jae-Hoon;Lho, Byeong-Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.5
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    • pp.8-14
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    • 2021
  • Post-tensioned prestressed concrete members experience immediate prestress losses as well as time-dependent prestress losses such as creep, dry shrinkage and relaxation. In addition, the stress of the upper and lower parts of the member changes due to the change in dead load due to the replacement of the upper slab and/or pavement. Such changes in fiber stress may affect the safety of the member, and it is necessary to adjust the prestressing force. Therefore, in this study, a screw type of re-tensioning post-tension kit is proposed, and it is verified that the safety against load and the stability against strain are satisfied through the load transfer test specified in EAD160004 and KCI-PS101.

A study on the Low Resistance Aluminum-Molybdenum Alloy for stretchable metallization (스트레처블 배선용 저저항 알루미늄-몰리브데늄 합금에 대한 연구)

  • Min-Jun-Yi;Jin-Won-Bae;Su-Yeon-Park;Jae-Ik-Choi;Geon-Ho-Kim;Jong-Hyun-Seo
    • Journal of the Korean institute of surface engineering
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    • v.56 no.2
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    • pp.160-168
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    • 2023
  • Recently, investigation on metallization is a key for a stretchable display. Amorphous metal such as Ni and Zr based amorphous metal compounds are introduced for a suitable material with superelastic property under certain stress condition. However, Ni and Zr based amorphous metals have too high resistivity for a display device's interconnectors. In addition, these metals are not suitable for display process chemicals. Therefore, we choose an aluminum based amprhous metal Al-Mo as a interconnector of stretchable display. In this paper, Amorphous Forming Composition Range (AFCR) for Al-Mo alloys are calculated by Midema's model, which is between 0.1 and 0.25 molybdenum, as confirmed by X-ray diffraction (XRD). The elongation tests revealed that amorphous Al-20Mo alloy thin films exhibit superior stretchability compared to pure Al thin films, with significantly less increase in resistivity at a 10% strain. This excellent resistance to hillock formation in the Al20Mo alloy is attributed to the recessed diffusion of aluminum atoms in the amorphous phase, rather than in the crystalline phase, as well as stress distribution and relaxation in the aluminum alloy. Furthermore, according to the AES depth profile analysis, the amorphous Al-Mo alloys are completely compatible with existing etching processes. The alloys exhibit fast etch rates, with a reasonable oxide layer thickness of 10 nm, and there is no diffusion of oxides in the matrix. This compatibility with existing etching processes is an important advantage for the industrial production of stretchable displays.

Effects of Cooling on Repeated Muscle Contractions and Tendon Structures in Human (냉각이 반복된 근수축과 사람의 건 구조에 미치는 영향)

  • Chae, Su-Dong;Jung, Myeong-Soo;Horii, Akira
    • The Journal of Korean Physical Therapy
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    • v.18 no.6
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    • pp.1-11
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    • 2006
  • Purpose: This study compared the effects of non-cold and cold conditions on the viscoelastic properties of tendon structures in vivo. Methods: Seven male subjects perfomed plantar flesion exercise with maximal isokinetic voluntary contraction, which consisted of muscle contraction for 6 see and relaxation for 60 secs, 10 times for 1 set, Totally 10 sets were repeated. Before and after each task, the elongation of the tendon and aponeurosis of the medial gastrocnemius muscle (MG) was directly measured by ultrasonography. (The relationship between the estimated tendon force and tendon elongation.) Tendon cross-sectional area and ankle joint moment arm were obtained from magnetic resonance imaging (MRI). The tendon force was calculated from the joint moments and the tendon moment arm and stress was obtained by dividing force by cross-sectional areas (CSA). The strain was measured from the displacements normalized to tendon length. Results: After cooling, the tendon force was larger in cold than non-cold. The value of the tendon stiffness of MVC were significantly higher under the cold condition than under the non-cold condition. The maximal strain and stress of $7.4{\pm}0.7%$ and $36.4{\pm}1.8$ MPa in non-cold and $7.8{\pm}8.5%,\;31.8{\pm}1.1$ MPa in cold (P<0.05). Conclusion: This study shows for the first time that the muscle endurance in cooling increases the stiffness and Young's modulus of human tendons. The improvement in muscle endurance with cooling was directly related to muscle and tendon.

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A Proposal of Autogenous Deformation and Self-induced Restrained Stress Test Using Thermal Analysis Results to Predict Early-Age Cracks of Externally Restrained Concrete Members (외부구속 콘크리트 부재의 초기균열 예측을 위해 온도해석 결과를 이용한 자가변형 및 구속응력 측정 실험의 제안)

  • Byun, Jong-Kwan;Kang, Won Ho;Kang, Jeong-Kil;Bae, Seong-Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.1
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    • pp.1-10
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    • 2018
  • It is difficult to predict the early-age cracks of strain restrained concrete members due to environmentally sensitive parameters. A new method is proposed to predict the cracks by test of autogenous deformation and self-induced restrained stress of specimens which simulates early-age crack state by hydration heat of the'Wall-On-Foundation'members. For this purpose, thermal analysis of entire structure considering the environmental condition is performed at first, and the specimens are set up where hydration heat was electronically controlled according to the analysis results. By measuring free deformation and force to compensate the autogenous strain including relaxation, feasibility of cracks can be estimated. The proposed method can predict the occurrence of cracks better than the material test of the early age concrete which has large variance. The method of this study is particularly useful when it is used as a preliminary experiments to predict the crack more precisely before full-scale concrete placement in construction of large structures.

Reconstruction Change of Si(5 5 12) Induced by Selective Bi Adsorption (Bi의 선택적 흡착으로 유도된 Si(5 5 12) 표면의 재구조변화)

  • Cho Sang-Hee;Seo Jae-M.
    • Journal of the Korean Vacuum Society
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    • v.15 no.2
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    • pp.152-161
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    • 2006
  • In order to test the capacity of Si(5 5 12) as a potential template for nanowire fabrication, Bi/Si(5 5 12) system has been studied by STM. With Bi deposition, Si(5 5 12) has been transformed to Si(3 3 7) terrace. Initially Bi atoms selectively replace Si-dimers and Si-adatoms with Bi-dimers and Bi-adatoms, respectively. With extended Bi adsorption, Bi-dimers adsorb on the pre-adsorbed Bi-dimers and Bi-atoms. These dimers in the second layer form Bi-dimer pairs having relatively stable $p^3$ bonding, Finally, the Bi-dimer adsorbs on the Bi-dimers in the second layer and saturates. It can be deduced that both surface transformation to (3 3 7) and site-selective Bi adsorption are possible due to substrate-strain relaxation through inserting Bi atoms into subsurface of Si substrate.

Effects of Intermittent Sciatic Nerve Stimulation on the Soleus and Medial Gastrocnemius Muscle Atrophy in Hindlimb Suspended Rats

  • Park, Byung-Rim;Cho, Jung-Shick;Kim, Min-Sun;Chun, Sang-Woo
    • The Korean Journal of Physiology
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    • v.26 no.2
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    • pp.159-166
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    • 1992
  • The present study was designed to evaluate effects of intermittent electrical stimulation of the sciatic nerve on the atrophic response of antigravity muscles, such as the soleus (slow m.) and medial gastrocnemius (fast m.) muscles. Rats (Sprague-Dawley, 245-255g) were subjected to a hindlimb suspension and divided into three groups : one was with hindlimb suspension (MS) and another with hindlimb suspension plus intermittent electrical stimulation of the sciatic nerve (HS ES). Control group (CONT) was kept free without strain of the hindlimb. After 7 days of hindlimb suspension, the soleus and medial gastrocnemius muscles were cut at their insertion sites, and were then connected to the force transducer to observe their mechanical properties. Optimal pulse width and frequency of electrical stimulation were 0.2ms, 20Hz for the soleus muscle and 0.3ms, 40Hz for the medial gastrocnemius muscle under supramaximal stimulation. Body weight and circumference of the hindlimb were significantly decreased in HS and HS-ES groups compared with the control group. In HS-ES group, however, the weight of the soleus muscle was not different from that in the control group while the weight of the medial gastrocnemius muscle was lower than that in the control group. In HS group, mechanical properties of muscle contraction including contraction time, half relaxation time, twitch tension, tetanic tension, and fatigue index of both muscles were significantly decreased compared with the control group except for twitch tension and tetanic tension of medial gastrocnemius muscle. The degree of atrophy of the soleus muscle in HS group was more prominent than that of the medial gastrocnemius muscle. Twitch tension and fatigue index of the soleus muscle and fatigue index of the medial gastrocnemius muscle in HS-ES group were not different from those of the control group. While mechanical properties of the soleus muscle examined were all significantly increased in HS-ES group compared with HS group, only contraction time and fatigue index of the medial gastrocnemius muscle were significantly increased in HS-ES group. These data indicate that intermittent electrical stimulation may be useful in prevention of muscle atrophy.

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