• Title/Summary/Keyword: body stress

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The Effect of Hyangbujapalmultang on The Serum Catecholamine Contents and Body Weight of Rats in Immobilization Stress (향부자팔물탕(香附子八物湯)이 구속(拘束) Stress 흰쥐의 체중(體重) 및 혈장(血漿) Catecholamines 함량(含量)에 미치는 영향(影響))

  • Kim, Byung-Woo;Kim, Sung-Ook
    • The Journal of Internal Korean Medicine
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    • v.22 no.4
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    • pp.683-689
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    • 2001
  • In order to study the anti-stress effect of hyangbujapalmultang, several measures of stress, including body weight changes, organ weight changes and catecholamine changes. The following result have been obtained: 1. The weight loss of contol group was $28.5{\pm}1.8g$, that of sample group was $20.3{\pm}1.6g$. This differance was statistcally significant. 2.The organ weight(Liver,Spleen,Kidney,Adrenal gland) was the only significant change in the spleen, in sample group comparing to control group. 3. The norepinephrine contents of control group was $695.5{\pm}22.7pg/ml$, that of sample group was $607.4{\pm}21.7pg/ml$. This shows significant difference in sample group comparing to contol group. 4. The epinephrine contents of control group was $212.8{\pm}9.8pg/ml$, that of sample group was $182.6{\pm}8.4pg/ml$. This shows significant differance in sample group comparing to control group. 5. The dopamine contents of control group was $504.5{\pm}31.3$, that of sample group was $463.4{\pm}27.8pg/ml$. This shows the value decreased, but none of it is significant. Based on avove results, it may be conculed that hyangbujapalmultang has anti-stress effects.

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Stress Simulation on Suspended Porcelain Insulators with Cement Displacement

  • Han S. W.;Cho H. G.;Park G. H.;Lee D. I.;Choi I. H;Kim T. Y.
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.3
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    • pp.19-24
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    • 2003
  • The experimental and simulation study of insulator failure by cement growth on suspended insulators (16,500kgf) for transmission line was discussed. To get more practical and analytic calculation results, the advanced program was used. This analysis tool was possible to calculate stress behaviors with mechanical loading when cement displacement happened. From simulation results, the. cement displacement changed with linear according to temperature. The shear stress was about $7 kgf/mm^2$ at $0.07\%$ displacement provided from $200^{\circ}C$, then it could be seen that the cement would be fractured even if $0.07\%$ displacement acted, because the cement had about $7-9 kgf/mm^2$ flexure strength. The curve patterns of shear stress with the increase of mechanical loading were changed at $0.02\%$ as a turning point, when the cement displacement was over $0.02\%$ the shear stresses decreased reversely with the increase of mechanical loading. From analysis on porcelain body it was known that there were enough margin to protect the fracture of porcelain body before the cement

Mind-Body Approach in the Area of Preventive Medicine: Focusing on Relaxation and Meditation for Stress Management (예방의학 영역에서 심신의학적 접근의 적용 가능성: 스트레스 관리를 위한 이완과 명상 기법을 중심으로)

  • Kang, Yune-Sik
    • Journal of Preventive Medicine and Public Health
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    • v.43 no.5
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    • pp.445-450
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    • 2010
  • Objectives: Emotional support and a stress management program should be simultaneously provided to clients as effective preventive services for healthy behavioral change. This study was conducted to review various relaxation and meditation intervention methods and their applicability for a preventive service program. Methods and results: The author of this paper tried to find various relaxation and meditation programs through a literature review and program searching and to introduce them. The 'Relaxation Response' and 'Mindfulness Based Stress Reduction (MBSR)' are the most the widely used meditative programs in mainstream medical systems. Abdominal breathing, Progressive Musclular Relaxation (PMR), Relaxative Imagery, Autogenic Training (AT) and Biofeedback are other well-known techniques for relaxation and stress management. I have developed and implemented some programs using these methods. Relaxation and meditation classes for cancer patients and a meditation based stress coping workshop are examples of this program. Conclusions: Relaxation and meditation seem to be good and effective methods for primary, secondary and tertiary preventive service programs. Program development and standardization and further study are needed for more and wider use of the mindbody approach in the preventive service area of medicine.

A Simplified Estimation of Stress Intensity Factor on the Hertzian Contact

  • Jin, Songbo;Kim, Seock-Sam
    • KSTLE International Journal
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    • v.1 no.1
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    • pp.8-11
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    • 2000
  • A surface crack in a semi-infinite body under Hertzian contact was considered. The simplified method used to estimate stress intensity factor K for specimen was extended to the model which is chosen in this paper. Very satisfactory results are obtained comparing with those known and it is proved that the method is more convenient than other methods. The results of the analysis show that due to the presence of $K_I$ for unlubricated condition, mode I fracture is active in the field below the surface and the maximum $K_{I}$ is obtained when the trailing edge of Hertzian contact reaches a position over the crack. The magnitudes of stress intensity factors $K_I$ and $K_Il$ increase with increasing friction forces. For a surface crack perpendicular to the contact surface, the stress intensity factor $K_I$ reaches its maximum value at a depth very close to the surface. Driving forve fer crack initiation and propagation is $K_I$ for unlubricated condition and $K_Il$ for both fluid and boundary lubricated condition.n.

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Study on Durability by Vibration and Fatigue of the Helicopter (헬기의 진동과 피로에 대한 내구성 연구)

  • Han, Moon-Sik;Cho, Jae-Ung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.6
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    • pp.63-69
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    • 2011
  • This study analyzes stress, fatigue and vibration on main rotor and body of helicopter. The maximum stress is shown on adjoint part between body and main rotor at the lower position of main rotor. As the maximum displacement amplitude is happened at 4000Hz, there is no resonance and the state of helicopter becomes safe at hovering without the abnormal air current and the disabled rotor. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample History' with the average stress of 0MPa to $-10^5MPa$ and the amplitude stress of 0MPa to $8.539{\times}10^5MPa$, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study by using the analysis of vibration and fatigue can be effectively utilized for safe and durable design of helicopter.

C]RASH ANALYSIS OF AUTO-BODY STRUCTURES CONSIDERING THE STRAIN-RATE HARDENING EFFECT

  • Kang, W.J.;Huh, H.
    • International Journal of Automotive Technology
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    • v.1 no.1
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    • pp.35-41
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    • 2000
  • The crashworthiness of vehicles with finite element methods depends on the geometry modeling and the material properties. The vehicle body structures are generally composed of various members such as frames, stamped panels and deep-drawn parts from sheet metals. In order to ensure the impact characteristics of auto-body structures, the dynamic behavior of sheet metals must be examined to provide the appropriate constitutive relation. In this paper, high strain-rate tensile tests have been carried out with a tension type split Hopkinson bar apparatus specially designed for sheet metals. Experimental results from both static and dynamic tests with the tension split Hopkinson bar apparatus are interpolated to construct the Johnson-Cook and a modified Johnson-Cook equation as the constitutive relation, that should be applied to simulation of the dynamic behavior of auto-body structures. Simulation of auto-body structures has been carried out with an elasto-plastic finite element method with explicit time integration. The stress integration scheme with the plastic predictor-elastic corrector method is adopted in order to accurately keep track of the stress-strain relation for the rate-dependent model accurately. The crashworthiness of the structure with quasi-static constitutive relation is compared to the one with the rate-dependent constitutive model. Numerical simulation has been carried out for frontal frames and a hood of an automobile. Deformed shapes and the Impact energy absorption of the structure are investigated with the variation of the strain rate.

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Effect of Hot Environment on the Body Temperature and Plasma Cortisol Concentration in Ruminant (高溫環境이 反芻家畜의 체온 및 혈장 Cortisol 농도에 미치는 影響)

  • Chung, Tae-Young;Yang, Young-Jik;Lee, Sang-Rak;Yoon, Hee-Sup
    • Journal of Animal Environmental Science
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    • v.1 no.1
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    • pp.39-45
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    • 1995
  • Temperatures of blood and skin, respiratory rate and plasma cortisol concentration in sheep at a warm (average ambient temperature of $15.3^{\circ}C$) and a hot (average ambient temperature of $27.0^{\circ}C$ environment were measured to investigate the effect of hot environment on the physiological responses in ruminant. Temperatures of core, mean skin and mean body in sheep were tended to increase at day time and to decrease at night time at both warm and hot environment, while 24-hr average for those temperatures were significantly higher at hot environment than at warm environment (P<0.05). The calculated body heat content was higher in sheep at hot environment than at warm environment (P<0.05). Respiratory rate and plasma cortisol concentration had no significant differences between warm and hot environment, suggesting that sheep were not stress by the hot environment in this experiment. It is, therefore, suggested that sheep were well adopted to hot environment by increasing body heat content against heat stress.

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Crack Analysis of Creep Material Containing Rigid Inclusion with Line Crack Shape (직선 균열 강체 함유물을 내포하는 크?재료의 균열 해석)

  • 이강용;김종성
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.7
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    • pp.91-97
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    • 1998
  • The analysis model is the infinite body consisted of power law creep material containing a rigid inclusion with line crack shape subjected to the arbitrarily directional stress on an infinite boundary. The crack analysis is performed using the complex pseudo-stress function. The strain rate intensity factor is determined in the closed form as new fracture mechanics parmeter which represents the magnitudes of stress and strain rate near the tip in power law creep material.

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Propagation Characteristics of a Surface Crack on a Semi-Infinite Body Due to Frictional Heating (마찰열에 의한 반무한체 표면균열의 전파특성)

  • Park, Jun-Ho;Park, Eun-Ho;Kim, Chae-Ho;Kim, Seock-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3126-3134
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    • 1996
  • In this paper, to examine the propagation of inclined surface crack due to frictional heating, analytic model is considered as the semi-infinite elastic body subjected to the thermo-mechanical loading of an asperity moving with a high speed. Considering the moving of frictional heat source and convection on a semi-infinite surface having inclined crack, theoretical analysis was carried out to estimate the propagation characteristics of thermo-mechanical crack. Numerical results showed that stress intensity factor $K_\prod/P_0\sqrt{c}$ is increasing with increasing velocity and frictional coefficient, inclined degree, decreasing crack length and the maximum value of it is positioned at the trailing edge. So it is shown that the propagation probability of surface crack is high at the trailing edge of contact area as increasing velocity and frictional coefficient, inclined degree, as decreasing crack length.

Algorithm of solving the problem of small elastoplastic deformation of fiber composites by FEM

  • Polatov, Askhad M.;Khaldjigitov, Abduvali A.;Ikramov, Akhmat M.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.305-321
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    • 2020
  • In this paper is presented the solution method for three-dimensional problem of transversely isotropic body's elastoplastic deformation by the finite element method (FEM). The process of problem solution consists of: determining the effective parameters of a transversely isotropic medium; construction of the finite element mesh of the body configuration, including the determination of the local minimum value of the tape width of non-zero coefficients of equation systems by using of front method; constructing of the stiffness matrix coefficients and load vector node components of the equation for an individual finite element's state according to the theory of small elastoplastic deformations for a transversely isotropic medium; the formation of a resolving symmetric-tape system of equations by summing of all state equations coefficients summing of all finite elements; solution of the system of symmetric-tape equations systems by means of the square root method; calculation of the body's elastoplastic stress-strain state by performing the iterative process of the initial stress method. For each problem solution stage, effective computational algorithms have been developed that reduce computational operations number by modifying existing solution methods and taking into account the matrix coefficients structure. As an example it is given, the problem solution of fibrous composite straining in the form of a rectangle with a system of circular holes.