• Title/Summary/Keyword: tension pressure

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Bibliographic Studies on the Tetrodotoxin(TTX) (복어 독(Tetrodotoxin)에 관한 문헌적 고찰)

  • Hwang, Tae-Joon;Kwon, Gi-Rok;Choe, Ick-Seon
    • Journal of Pharmacopuncture
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    • v.3 no.2
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    • pp.1-25
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    • 2000
  • We were trying to study the validity of Puffer fish's poison(Tetrodotoxin- TTX) to make a traditional Korean Medical treatment. The following conclusions were made after literary studies. 1. The first record of the puffer fish dates back 2000 years ago in the Chinese text Book of Mountain and Sea and other texts from the similar period. 2. Puffer fish's poison IS known as tetrodotoxin which is an amino perhydroquinazoline compound. It has a chemical formula of $C_{11}H_{17}N_3O_8$ in the hemiacetal structure and has the molecular weight of 319. 3. Tetrodotoxin (TTX) plays a role as potent neurotransmitter blocker by blocking the $Na^+$ -gate channel which hinders the influx of $Na^+$ ion into the cell. 4. Symptoms of the puffer fish poisoning ranges from blunted sense in the lips and tongue, occasional vomiting in the first degree to sudden descending of the blood pressure, apnea, and other critical conditions in the fourth degree. Intoxication of the puffer fish poison progresses at a rapid pace as death may occur after an hour and half up to eight hours in maximum. Typical death occurs after four to six hours. 5. Ways to treat the puffer fish poisoning include gastric irrigation, induce vomiting, purgation, intravenous fluid injection, and correcting electrolytic imbalance and acidosis. In cases of dyspnea, apply oxygen inhalation and conduct artificial respiration. 6. Tetrodotoxin (TTX) may be applied in treating brain disorders, ocular pain, excess pain in the large intestine and ileum, and relieving tension of the skeletal museles, neuralgia, rheumatism, arthritis, and etc. 7. In terms of Oriental medicine, the puffer fish poison has characteristics of sweet, warm, and poisonous. It's known efficacies are to tonify weakness, dispel damp, benefit the lower back, relieve hemorrhoid, kills parasites, remove edema, and so forth. And the puffer fish eggs processed with ginger are said to be effective against tuberculosis and lung cancer, thus, it's validity must be investigated and further research should be followed.

Study on the Development of Reinforced Earth Retaining Wall (보강옹벽개발연구)

  • 유용환
    • Geotechnical Engineering
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    • v.2 no.3
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    • pp.51-66
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    • 1986
  • The design of fabric reinforced retaining wall structure was discussed in this article. It was confirmed that the reinforced retaining earth wall which was designed by new theoretical formulae developed this time was stable structurally and economically. The plastic fabric filter which was placed in layers behind the facing element reduced the lateral earth pressure on the wall elements in comparison with a conventional retaining earth walls. The reinforcing characteristics of earth wall was governed by the spacing of fabric layers, effective length of fabrics, particle distribution and compaction, and thus it is essential that, in the construction field, the reinforcing strips should be selected in order to develop the maximum friction forces bet.eon soil and fabric filters. The maximum tensile stress developed from the reinforcing strips was appeared at a little far distance from the back of skin element and it was not well agreed with the Rankine's theory but distributed well as a symmetrical shape against the point of the maximum tensile stress. The total length of the different layers should be sufficient so that the tension in the fabric strip could be transferred to the backfill material. Also the total stability of reinforced earth wall should be checked with respect to a failure surface which extended blond the different lathers.

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A preliminary simulation for the development of an implantable pulsatile blood pump

  • Di Paolo, Jose;Insfran, Jordan F.;Fries, Exequiel R.;Campana, Diego M.;Berli, Marcelo E.;Ubal, Sebastian
    • Advances in biomechanics and applications
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    • v.1 no.2
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    • pp.127-141
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    • 2014
  • A preliminary study of a new pulsatile pump that will work to a frequency greater than 1 Hz, is presented. The fluid-structure interaction between a Newtonian blood flow and a piston drive that moves with periodic speed is simulated. The mechanism is of double effect and has four valves, two at the input flow and two at the output flow; the valves are simulated with specified velocity of closing and reopening. The simulation is made with finite elements software named COMSOL Multiphysics 3.3 to resolve the flow in a preliminary planar configuration. The geometry is 2D to determine areas of high speeds and high shear stresses that can cause hemolysis and platelet aggregation. The opening and closing valves are modelled by solid structure interacting with flow, the rhythmic opening and closing are synchronized with the piston harmonic movement. The boundary conditions at the input and output areas are only normal traction with reference pressure. On the other hand, the fluid structure interactions are manifested due to the non-slip boundary conditions over the piston moving surfaces, moving valve contours and fix pump walls. The non-physiologic frequency pulsatile pump, from the viewpoint of fluid flow analysis, is predicted feasible and with characteristic of low hemolysis and low thrombogenesis, because the stress tension and resident time are smaller than the limit and the vortices are destroyed for the periodic flow.

Effects of Norepinephrine and Neuropeptide Y on the Contractility of Small Mesenteric Artery from 2K1C and DOCA-Salt Hypertensive Rats

  • Nam, Sang-Chae;Kang, Seong-Su;Kim, Won-Jae;Lee, Jong-Un
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.1
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    • pp.55-61
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    • 2000
  • The present study was conducted to investigate the possible role of the sympathetic nervous system in two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension. 2K1C and DOCA- salt hypertension were made in Sprague-Dawley rats. Four weeks after induction of hypertension, systolic blood pressure measured in conscious state was significantly higher in 2K1C $(216{\pm}18\;mmHg)$ and DOCA-salt $(205{\pm}29\;mmHg)$ groups than that in control $(128{\pm}4\;mmHg).$ The third branches (<300 ${\mu}m$ in outer diameter) of the mesenteric artery were isolated and cut into ring segments of $2{\sim}3$ mm in length. Each ring segment was mounted in tissue bath and connected to a force displacement transducer for measurement of isometric tension. The arterial rings were contracted by application of norepinephrine (NE) in a dose-dependent manner. The amplitude of the NE-induced contraction of the vessels was significantly larger in hypertension than in control. The NE-induced contraction was significantly enhanced by neuropeptide Y (NPY) in hypertension. Reciprocally, NPY-elicited vasocontraction was increased by NE in hypertension. These results suggest that the sympathetic nervous system contributes to the development of 2K1C and DOCA-salt hypertension.

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A Study on Performance of Initial Blowoff Flow for a Fuel Pump with Various Temperature and Composition Condition in LPG Engine (자동차용 LPG 펌프의 온도 및 연료조성에 따른 초기토출성능에 관한 연구)

  • Park, Cheol-Woong;Kim, Chang-Up;Choi, Kyo-Nam
    • Journal of the Korean Institute of Gas
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    • v.12 no.2
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    • pp.12-17
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    • 2008
  • The In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG (Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. In this study, experiments are performed to get initial performance and efficiency of the fuel pump under different condition of the temperature and composition of fuel. The characteristics of vane type fuel pump were investigated to access the applicability on LPLi engine.

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Oxygen Diffusion According to the Fitting Conditions of Contact Lens (콘택트렌즈의 피팅조건에 따른 산소확산)

  • Kim, Dae Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.3
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    • pp.35-43
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    • 2008
  • Purpose: This review article was written to investigate how the various factors, such as lacrimal thickness, CL's thickness and Dk, affects the influx of $O_2$ diffusion into the cornea. Methods: A mathematical model was proposed to analyze the oxygen diffusion reaching the cornea through the tear layers and contact lens based on Fick's law and the principle of continuity of the diffusion flux through the each layers. Results: The model predicts how the parameters such as the thickness of tear layer on the cornea, both the Dk and thickness of contact lenses etc., affect the oxygen tension at cornea and oxygen flux entering the cornea. Conclusions: It is found that either too flat or too tightly fitted contact lenses can cause the oxygen deficiency at/inside the periphery of the cornea because of the reduction of oxygen flux resulted from too thickened tear layer.

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Analysis and Design of Shoes Using Non-Linear Finite Element Method (비선형 유한요소법을 이용한 신발 해석 및 설계)

  • Kim, B.S.;Moon, B.Y.
    • Elastomers and Composites
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    • v.38 no.3
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    • pp.195-205
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    • 2003
  • This paper presents an analytic method and a design technique for golf shoes with air-cycled pump in the midsole. The golf shoes are modeled using the finite element method for better design by considering the configuration of the midsole and the outsole, which compose the golf shoes. Also the optimum size and shape of air-cycled pump in the midsole is examined. The values or standard human pressure for boundary conditions are adopted for the FEA(Finite Element Analysis). The unknown constants of the strain energy function of Ogden type are observed in accordance with the axial tension test. By the commercial FEM software for nonlinear analysis, MARC V7.3, the strains and the values of volume change for the midsole and the outsole are obtained, respectively. It can be concluded that results obtained by FEM in the midsole and the outsole are different depending on the characteristic of elastomer The results reported herein provide better understanding of analyzing the golf shoes. Moreover, it is believed that those properties of the results can be utilized in the shoes industry to develop the effective design method.

A Study on the Correlation of Cold Hypersensitivity and Digestive Function (여성의 냉한 정도와 소화기능의 상관성에 관한 연구)

  • Nam, Eun-Young;Lee, Jeong-Im;Kim, Gyeong-Mi;Kim, Hyung-Jun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.27 no.1
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    • pp.140-151
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    • 2014
  • Objectives: Cold hypersensitivity has been regarded to be associated with digestive function. This study is aims to evaluate the correlation between digestive function and coldness of hands. Methods: We made a research of 80 women who is in ${\bigcirc}{\bigcirc}$ University. The patients were subjected to thermometer, and those with thermal difference between upper arm and palm were diagnosed with cold hypersensitivity. The patients were divided into two group by cold hypersensitivity group (n=20), and non-cold hypersensitivity group (n=19), and 39 women are mesured by Nepean dyspepsia index-Korean version (NDI-K) to evaluate the severity of functional dyspepsia. Results: There was no difference between two groups on age, height, weight. In functional dyspepsia symptom score, 6 symptoms (Pain in upper abdomen, Burning in upper abdomen, Cramps in upper abdomen, Pressure in upper abdomen, Vomiting, Bad breath) out of 15 were significantly increased in cold hypersensitivity group compared with non-cold hypersensitivity group. And in quality of life score, 3 domains (Tension/sleep, Interference with daily activities, Knowledge/control) out of 5, and total quality of life score were significantly decreased in cold hypersensitivity group compared with non-cold hypersensitivity group. Conclusions: This study shows the correlation between cold hypersensitivity and digestive function.

Research on the impact effect of AP1000 shield building subjected to large commercial aircraft

  • Wang, Xiuqing;Wang, Dayang;Zhang, Yongshan;Wu, Chenqing
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1686-1704
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    • 2021
  • This study addresses the numerical simulation of the shield building of an AP1000 nuclear power plant (NPP) subjected to a large commercial aircraft impact. First, a simplified finite element model (F.E. model) of the large commercial Boeing 737 MAX 8 aircraft is established. The F.E. model of the AP1000 shield building is constructed, which is a reasonably simplified reinforced concrete structure. The effectiveness of both F.E. models is verified by the classical Riera method and the impact test of a 1/7.5 scaled GE-J79 engine model. Then, based on the verified F.E. models, the entire impact process of the aircraft on the shield building is simulated by the missile-target interaction method (coupled method) and by the ANSYS/LS-DYNA software, which is at different initial impact velocities and impact heights. Finally, the laws and characteristics of the aircraft impact force, residual velocity, kinetic energy, concrete damage, axial reinforcement stress, and perforated size are analyzed in detail. The results show that all of them increase with the addition to the initial impact velocity. The first four are not very sensitive to the impact height. The engine impact mainly contributes to the peak impact force, and the peak impact force is six times higher than that in the first stage. With increasing initial impact velocity, the maximum aircraft impact force rises linearly. The range of the tension and pressure of the reinforcement axial stress changes with the impact height. The perforated size increases with increasing impact height. The radial perforation area is almost insensitive to the initial impact velocity and impact height. The research of this study can provide help for engineers in designing AP1000 shield buildings.

Correlation between contraction ratio, endurance, and muscle tone of cervical muscles

  • Hong, Ji-Hee;Lee, Dong-Hyeon;Kim, Seong-Eun;Seo, Dong-kwon
    • Physical Therapy Rehabilitation Science
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    • v.9 no.4
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    • pp.302-308
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    • 2020
  • Objective: The endurance and strength of deep neck flexor (DNF) muscles have a major role on the function and stability of the cervical spine. In recent years, there has been a lack of research that have investigated the muscle tone of the superficial neck muscles. The purpose of this study was to examine the relationship of between contraction ratio of the DNF and sternocleidomastoid (SCM) muscles, DNF endurance, and muscle tension of the neck muscles. Design: Cross-sectional study. Methods: Forty-seven subjects (male=20, female=27) participated in this study. The muscle tone of the upper trapezius (UT), SCM, and suboccipital (SO) muscle was measured using a contact soft tissue tone-measuring instrument. For the contraction ratio of the SCM and longus colli muscle, the thickness of the relaxation and maximum contraction state of the SCM and longus colli muscles were assessed using a diagnostic ultrasound measuring instrument and a pressure biofeedback unit. The deep neck flexor endurance test (DNFET) was performed in a cranio-cervical flexion posture. The correlations between the measured variables were investigated. Results: The relationship between the DNFET and SO tone showed a significant negative correlation (p<0.05). The relationship between the DNFET and contraction ratio showed a significant positive correlation (p<0.01). There was no significant correlation between the DNFET and SCM and UT tone. Conclusions: This study confirmed that there is a relationship between DNF endurance, DNF activation, and SO tone. The information on the results of this study may be used as a reference that can be actively applied in the clinical environment.