• Title/Summary/Keyword: Contraction stress

Search Result 200, Processing Time 0.023 seconds

A Clinical Report of Tension Headache (긴장성 두통 환자 치험(治驗) 1례(例) 보고)

  • Lee, Seung-Hee;Jung, In-Chul;Lee, Sang-Ryong
    • Journal of Haehwa Medicine
    • /
    • v.15 no.1
    • /
    • pp.111-115
    • /
    • 2006
  • Tension headache is one of the most common form of headache. It may occur at any age, but is most common in adult and adolescents. One cause of this muscle contraction is a response to stress that induces changes and imbalance on autonomic nerve system. To cure tension headache, getting rid of psychological stress and anxiety have to do first. In this case, we described a 42 years old woman who diagnosed as tension headache. She complained headache with scruff pain, dyspepsia, nausea and coldness of toes. through oriental medical treatment(for example, acupuncture, herbal medicine ect.), her condition was improved.

  • PDF

Vacuum system design using the shear stress limit of clamp and the axial stress associated with bellows contraction (Bellows 수축에 따른 축방향응력과 clamp의 전단응력한계를 이용한 진공 system 설계)

  • Jeong, Jin-Yong;Yu, Yeong-Gun;Im, Jin-Hyeong;Kim, Hyeong-Ju;Choe, Yong-Seop;Ju, Jeong-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2014.11a
    • /
    • pp.306-307
    • /
    • 2014
  • 진공용 장비의 sealing 방법으로 Cu gasket을 이용한 CF type과 O-ring을 이용한 NW type이 있다. 이중 O-ring을 이용한 sealing 방법에는 clamp를 사용하게 되는데 Al 합금으로 제작된 clamp에 bellows의 수축 시 받는 전단응력과 전단응력한계 이상의 힘을 받았을 때의 clamp 파손에 따른 역압에 의한 TMP 손상 분석.

  • PDF

A study on the axial force and displacement characteristics of turnout on a bridge (분기기와 교량의 상호작용 특성에 관한 연구)

  • Yang, Shin-Chu;Kim, In-Jae;Kim, Eun
    • Proceedings of the KSR Conference
    • /
    • 2006.11b
    • /
    • pp.1306-1311
    • /
    • 2006
  • Most of design parameters of Railway Structures are determined by the serviceability requirements, rather than the structural safety requirements. The serviceability requirements come from Ensuring of Running Safety and Ride Comfort of Train, Reduction of Track Maintenance Work Track-Bridge Interaction should be considered in the design of railway structures. In this study, a numerical method which precisely evaluate an axial force in rail and a rail expansion and contraction when turnout exist in succession on a CWR on a ballasted or on a ballastless track of bridge is developed. From the parameter studies using the developed method, additional stress of stock rail almost 25% is generated due to stock and lead rail interaction, even embankment not bridge. In case of ballasted track, additional stress of stock rail on bridge is very greater than on embankment, and therefore require detailed review in bridge design with turnout. Stresses of turnout rails on bridge are very sensitive according to the installed positions. In case of ballastless track, Stresses of turnout rails are similar as those of normal track

  • PDF

Finite element modeling of high Deborah number planar contraction flows with rational function interpolation of the Leonov model

  • Youngdon Kwon;Kim, See-Jo;Kim, Seki
    • Korea-Australia Rheology Journal
    • /
    • v.15 no.3
    • /
    • pp.131-150
    • /
    • 2003
  • A new numerical algorithm of finite element methods is presented to solve high Deborah number flow problems with geometric singularities. The steady inertialess planar 4 : 1 contraction flow is chosen for its test. As a viscoelastic constitutive equation, we have applied the globally stable (dissipative and Hadamard stable) Leonov model that can also properly accommodate important nonlinear viscoelastic phenomena. The streamline upwinding method with discrete elastic-viscous stress splitting is incorporated. New interpolation functions classified as rational interpolation, an alternative formalism to enhance numerical convergence at high Deborah number, are implemented not for the whole set of finite elements but for a few elements attached to the entrance comer, where stress singularity seems to exist. The rational interpolation scheme contains one arbitrary parameter b that controls the singular behavior of the rational functions, and its value is specified to yield the best stabilization effect. The new interpolation method raises the limit of Deborah number by 2∼5 times. Therefore on average, we can obtain convergent solution up to the Deborah number of 200 for which the comer vortex size reaches 1.6 times of the half width of the upstream reservoir. Examining spatial violation of the positive definiteness of the elastic strain tensor, we conjecture that the stabilization effect results from the peculiar behavior of rational functions identified as steep gradient on one domain boundary and linear slope on the other. Whereas the rational interpolation of both elastic strain and velocity distorts solutions significantly, it is shown that the variation of solutions incurred by rational interpolation only of the elastic strain is almost negligible. It is also verified that the rational interpolation deteriorates speed of convergence with respect to mesh refinement.

Quantitative Estimation of Joint Spacing for Concrete Slab to Prevent Cracking of Drying Shrinkage (건조수축에 따른 균열 방지를 위한 콘크리트 슬래브의 정량적 줄눈 간격 산정)

  • Lee, Su-Jin;Lee, Hoi-Keun;Lee, Seung-Hoon;Won, Jong-Pil
    • Journal of the Korea Concrete Institute
    • /
    • v.23 no.3
    • /
    • pp.289-294
    • /
    • 2011
  • The installation of joint is to prevent random cracking due to drying shrinkage stress of concrete slab. However contraction joint spacing is empirically implemented into slab constructions without detail calculation based on quantitative criteria. In this study, shrinkage strain of concrete due to concrete shrinkage stress was measured to suggest joint spacing based on the study results. The test environmental conditions were applied temperature of $15^{\circ}C$ and relative humidity of 60%. The design compressive strength used was 30 MPa and 40 MPa, which are currently used in concrete slab designs. The drying shrinkage test result was applied to drying shrinkage models (ACI 209R, CEB MC 90, B3, GL 2000 and Sakata). The results showed that the most appropriate model was ACI 209R model. Based on the research findings, quantitative contraction joint spacing locations were calculated.

Influence of Defects on Electrical Characteristics of Distributing Cable Termination (배전급 케이블 종단부의 결점이 전기적 특성에 미치는 영향)

  • Kim, Sang-Hyun;Choi, Jae-Hyeong;Choi, Jin-Wook;Kim, Young-Seok;Kim, Sun-Gu;Baek, Seung-Myeong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.2
    • /
    • pp.190-195
    • /
    • 2009
  • This paper introduces experimental investigates of an electrical accident of the distributing cable termination with simulated a shoddy construction. We prepared two termination kites, one is built-in type, the other is heat contraction type. Also, we manufactured cable termination that have simulated defect by badness construction and investigated their insulation characteristics such as ac (35[kV], 1[min]) and impulse (95[kV], $1.2{\times}50[{\mu}s]$) withstand test. The influence of defects such as thickness decrease, the gap between stress-con of housing and semiconductor and heating time on insulating properties of the termination have been studied. The thickness decrease of an insulator decreases ac breakdown strength suddenly and the breakdown traces of the insulator that is damaged by knife displayed elliptic shape. The gap of between stress-con and semiconductor deteriorates dielectric strength of insulator seriously. In heat contraction type, the ac breakdown voltage became low when the heating time is short.

The Differences in Patellofemoral Compression Force with Different Height (드롭랜딩 시 높이에 따른 슬개대퇴 압박력의 차이)

  • Cho, Joon-Haeng;Kim, Kyoung-Hun;Moon, Gon-Sung;Lee, Sung-Cheol
    • Korean Journal of Applied Biomechanics
    • /
    • v.21 no.3
    • /
    • pp.335-343
    • /
    • 2011
  • Patellofemoral pain syndrome is the most common problem involving the knee, accounting for 25% of knee injuries. Repetitive, overuse activities cause increased force at the patellofemoral joint, resulting in pain during flexion and extension activities. Most research have been conducted in exploring the patellofemoral compressive force in gait, squat and lunges, even though in real cases, possibilities in landing exist. The purpose of this study was to compare the differences in patellofemoral compressive force according to two different height. Sixteen collegiate male students(age: 22.25 ${\pm}$ 3.30 yrs, height: 177.25 ${\pm}$ 4.44 cm, weight: 77.50 ${\pm}$ 8.18 kg) were chosen. The subjects performed drop landings in 45 cm, 60 cm. The findings demonstrated that higher height showed peak knee extension moment, quadriceps contraction force, patellofemoral compressive force with increased VGRF. Regarding the patellofemoral joint compressive force, it increased by quadriceps contraction force with knee flexion during landing, yet, it showed no difference in maximal knee flexion. To minimize patellofemoral joint stress and reduce the likelihood of developing PFPS, we recommend that predesigned quadriceps and hip muscle group strengthening are needed during conditioning and training.

Transient Receptor Potential C4/5 Like Channel Is Involved in Stretch-Induced Spontaneous Uterine Contraction of Pregnant Rat

  • Chung, Seungsoo;Kim, Young-Hwan;Joeng, Ji-Hyun;Ahn, Duck-Sun
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.18 no.6
    • /
    • pp.503-508
    • /
    • 2014
  • Spontaneous myometrial contraction (SMC) in pregnant uterus is greatly related with gestational age and growing in frequency and amplitude toward the end of gestation to initiate labor. But, an accurate mechanism has not been elucidated. In human and rat uterus, all TRPCs except TRPC2 are expressed in pregnant myometrium and among them, TRPC4 are predominant throughout gestation, suggesting a possible role in regulation of SMC. Therefore, we investigated whether the TRP channel may be involved SMC evoked by mechanical stretch in pregnant myometrial strips of rat using isometric tension measurement and patch-clamp technique. In the present results, hypoosmotic cell swelling activated a potent outward rectifying current in G protein-dependent manner in rat pregnant myocyte. The current was significantly potentiated by $1{\mu}M$ lanthanides (a potent TRPC4/5 stimulator) and suppressed by $10{\mu}M$ 2-APB (TRPC4-7 inhibitor). In addition, in isometric tension experiment, SMC which was evoked by passive stretch was greatly potentiated by lanthanide ($1{\mu}M$) and suppressed by 2-APB ($10{\mu}M$), suggesting a possible involvement of TRPC4/5 channel in regulation of SMC in pregnant myometrium. These results provide a possible cellular mechanism for regulation of SMC during pregnancy and provide basic information for developing a new agent for treatment of premature labor.

The Evaluation of 10 week urinary Tract Function Promotion Program for the Elderly Women in the Community (노인 여성의 요로기능증진 10주 프로그램 개발 및 평가)

  • Kim, Jeung-Im
    • Women's Health Nursing
    • /
    • v.9 no.4
    • /
    • pp.439-448
    • /
    • 2003
  • Purpose: This study was accomplished to apply and to evaluate the 10-week Urinary tract Function Promotion for the Elderly Women (UFPE), and to suggest guideline and to be utilized on the community level. Method: Subjects were 30 persons of 16 healthy elderly and 14 hemiplegic elderly. This UFPE was composed of diagnosis of incontinence & evaluation of physical condition, understanding of urogenital system & urinary incontinence management. UFPE was evaluated by subjective urinary condition, intra-vaginal contraction power, continence self-efficacy (CSE), incontinence stress, geriatric depression. The collected data was analyzed using Wilcoxon Matched Signed-Ranks test by SPSS/WIN program. Result: 5 subjects (31.2%) in healthy group and 2 subjects(14.3%) in hemiplegic group have a daytime frequency, 14 subjects(87.5%) in healthy- group and 14 subjects(100%) have a nocturia. After program, subjective urinary condition was increased just only healthy elderly (Z=-2.545, p<0.05), while intra-vaginal contraction power and CSE were increased significantly only in the hemiplegic elderly (Z=-2.57, P<0.05: Z=-2.29, p<0.05). There were barriers not to comply program guidance such as inadequate perception of pelvic floor muscle, forget to do exercise, fatigue. Conclusion: UFPE was effective in increasing subjective urinary condition for healthy elderly and in increasing intra-vaginal contraction power and continence self-efficacy for the hemiplegic elderly women. I suggest that this UFPE be utilized at the health center and elderly center, and public health nurse counsel and guide the elderly's work through phone service.

  • PDF

Effect of Forearm Dynamic Taping on Muscle Activity of Extensor Carpi Radialis Brevis During Wrist Isometric and Isotonic Contraction (아래팔 다이나믹 테이핑 적용에 의한 손목 등척성과 등장성 수축 시 짧은 노쪽손목폄근 근활성도의 변화)

  • Huang, Tian-zong;Kim, Suhn-yeop
    • Physical Therapy Korea
    • /
    • v.28 no.2
    • /
    • pp.93-100
    • /
    • 2021
  • Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal conditions of the upper extremity with pain and wrist extension disability. The tendon which is most affected is the extensor carpi radialis brevis (ECRB). Previous study evaluated the effect of taping technique on patient with LE, but no study investigated the changes of electromyography (EMG) on ECRB when using dynamic taping (DT) technique. Objects: The aim of this study was to investigate the effect of DT technique using dynamic tape on muscle activity of ECRB during wrist isometric extension, isotonic extension and flexion. Methods: Twenty-one healthy subjects volunteered to participate in this study. Subjects were instructed to perform wrist isometric extension, isotonic extension and flexion without and with DT on origin area of ECRB. Wrist isometric extension was performed at 75%, 50% and 25% (%maximal voluntary contraction force), respectively, based on maximum contraction force. Isotonic extension and flexion test used dumbbell. EMG data was collected from ECRB. Results: EMG of ECRB were statistically significant decrease in wrist isotonic extension after DT (p < 0.05). Significant increase in wrist isometric extension during 25% and 50% force task (p < 0.05). Conclusion: This study applied DT technique to suppress the wrist extensor muscles in 21 healthy adults in their twenties. Change in muscle activity was compared in the ECRB muscle during wrist isometric extension, isotonic extension and flexion task. Based on the results of this study, the DT technique applied to the wrist and forearm area can reduce the load on the wrist extensors when the wrist performs various movements during daily life movements or repetitive tasks, and by using these effects, excessive stress is applied to tennis elbow patients.