• 제목/요약/키워드: pressure effects

검색결과 7,977건 처리시간 0.031초

The Immediate Effects of Elastic Taping on Center of Pressure and Foot Pressure Distribution

  • Jung-Hee Kim;Jong-Ho Kook;Sang-Mi Lee;Eun-Bin Ko;Song-Yi Han;Yeon-Jeong Kim;Byeong-Jun Min
    • PNF and Movement
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    • 제22권1호
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    • pp.23-30
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    • 2024
  • Purpose: Ankle instability is a common issue in both daily activities and sports, often leading to recurrent injuries. Elastic taping is a non-pharmacological intervention used to improve ankle stability. This study aimed to investigate the immediate effects of elastic taping on ankle stability, center of pressure (COP) movement, and foot pressure distribution. Methods: A single-group pre-posttest design was employed, with 30 participants included in the study. Plantar pressure and COP parameters were measured before and after the application of elastic taping. Taping was administered in three distinct patterns to enhance ankle stability. Results: Immediate effects of elastic taping were evident in COP parameters. Following taping application, there was a significant decrease in COP total displacement, COP area, and COP velocity. However, no significant changes were observed in plantar pressure parameters. Conclusion: The application of elastic taping in this study demonstrated immediate effects on ankle stability and COP parameters, indicating its potential as a viable intervention for improving balance. Further research with larger sample sizes and long-term follow-up is needed to elucidate the sustained effects of elastic taping on ankle stability.

에어댐의 높이가 차체 표면의 압력변화에 미치는 영향 (Effect of the Heights of Air Dam on the Pressure Distribution of the Vehicle Surface)

  • 박종수;김성준
    • 산업기술연구
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    • 제22권B호
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    • pp.27-34
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    • 2002
  • 3-D numerical studies are performed to investigate the effect of the air dam height and approaching air velocities on the pressure distribution of notchback road vehicle. For this purpose, the models of test vehicle with four different air dam heights are introduced and PHOENICS, a commercial CFD code, is used to simulate the flow phenomena and to estimate the values of pressure coefficients along the surface of vehicle. The standard $k-{\varepsilon}$ model is adopted for the simulation of turbulence. The numerical results show that the height variation of air dam makes almost no influence on the distribution of the value of pressure coefficient along upper and rear surface but makes strong effects on the bottom surface. That is, the value of pressure coefficient becomes smaller as the height is increased along the bottom surface. Approaching air velocity makes no differences on pressure coefficients. Through the analysis of pressure coefficient on the vehicle surface, one tries to assess aerodynamic drag and lift of vehicle. The pressure distribution on the bottom surface affects more on lift than the pressure distribution on the upper surface of the vehicle does. The increase of air dam height makes positive effects on the lift decrease but no effects on drag reduction.

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Notchback자동차의 트렁크 높이와 공기속도가 차체 표면의 압력변화에 미치는 영향 (Effect of Trunk Height and Approaching Air Velocity of Notchback Road Vehicles on the Pressure Distribution of the Car Surface)

  • 박종수;최병대;김성준
    • 한국자동차공학회논문집
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    • 제10권6호
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    • pp.178-186
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    • 2002
  • 3-D numerical studies are performed to investigate the effect of the trunk height and approaching air velocities on the pressure distribution of notchback road vehicle. For this purpose, the models of test vehicle with four different trunk heights are introduced and PHOENICS, a commercial CFD code, is used to simulate the flow phenomena and to estimate the values of pressure coefficients along the surface of vehicle. The standard k-$\xi$ model is adopted for the simulation of turbulence. The numerical results say that the height variation of trunk makes almost no influence on the distribution of the value of pressure coefficient along upper surface but makes very strong effects on the rear surface. That is, the value of pressure coefficient becomes smaller as the height is increased along the rear surface and the bottom surface. Approaching air velocity make no differences on pressure coefficients. Through the analysis of pressure coefficient on the vehicle surfaces one tried to assess aerodynamic drag and lift of vehicle. The pressure distribution on the rear surface affected more on drag and lift than pressure distribution on the front surface of the vehicle does. The increase of trunk height makes positive effects on the lift decrease but negative effects on drag reduction.

Effects of quadriceps angle on patellofemoral contact pressure

  • Yoo, Yoon-Hyeong;Lee, Sung-Jun;Jeong, Soon-wuk
    • Journal of Veterinary Science
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    • 제21권5호
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    • pp.69.1-69.11
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    • 2020
  • Background: An inappropriate Q angle may affect the biomechanics of the canine patellofemoral joint. Objectives: The purpose of this study was to evaluate the effects of changes in quadriceps angle (Q angle) on patellofemoral joint pressure distribution in dogs. Methods: Eight stifles were positioned at 45, 60, 75, 90, 105, and 120° of flexion in vitro, and 30% body weight was applied through the quadriceps. Patellofemoral contact pressure distribution was mapped and quantified using pressure-sensitive film. For the pressure area, mean pressure, peak pressure, medial peak pressure, and lateral peak pressure, differences between groups according to conditions for changing the Q angle were statistically compared. Results: Increases of 10° of the Q angle result in increases in the pressure area (P = 0.04), mean pressure (P = 0.003), peak pressure, and medial peak pressure (P ≤ 0.01). Increasing the Q angle by 20° increases the pressure area (P = 0.021), mean pressure (P ≤ 0.001), peak pressure (P ≤ 0.01), and medial peak pressure (P ≤ 0.01) significantly, and shows higher mean (P ≤ 0.001) and peak pressures than increasing by 10°. Decreasing the Q angle increases the mean pressure (P = 0.013), peak pressure, and lateral peak pressure (P ≤ 0.001). Conclusions: Both increases and decreases in the Q angle were associated with increased peak patellofemoral pressure, which could contribute to the overloading of the cartilage. Therefore, the abnormal Q angle should be corrected to the physiologically normal value during patellar luxation repair and overcorrection should be avoided.

측뇌실내(側腦室內) Norepinephrine의 가토심박(家兎深博) 급(及) 혈압(血壓)에 미치는 영향(影響) (Effects on intraventricular norepinephrine on blood pressure and heart rate of rabbits)

  • 신승호
    • 대한약리학회지
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    • 제1권1호
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    • pp.53-61
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    • 1965
  • Effects of intraventricular norepinephrine (NE) on rabbit blood pressure and heart rate were investigated. 1) Blood pressure was little affected by small doses of NE (below $500{\mu}g$) but showed marked rise by 1 mg. 2) Heart rate was decreased by intraventriccular NE $(200{\sim}500{\mu}g)$. One mg of NE caused less pronounced bradycardia than with smaller doses. The bradycardia could not be observed in vagotomized or atropinized animals. 3) Intraventricular NE potentiated reflexive bradycardia produced by 5-hydroxytryptamine. 4) Cord-sectioned rabbit showed different responses; the smaller doses $(100{\sim}200{\mu}g)$ produced transitory bradycardia and depression of blood pressure, which followed by tachycardia and pressure rise. The transitory bradycardia and depressor effects were not observed in cord-sectioned and vagotomized rabbit. 5) Treatment of animals with reserpine, guanethidine and hexamethonium changed the effects of intraventricular NE on blood pressure, i.e., in these cases the smaller doses of NE caused maked elevation of blood pressure. 6) From these observations it was inferred that central NE caused stimulation of cardioinhibitory and vasomotor center. The former seemed to be more sensitive to NE than the latter. Susceptibility of the vasomotor center to NE seemed to be influenced by peripheral sympathetic tone.

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채취 시기가 다른 표고버섯의 첨가가 SHR 흰쥐의 혈압 및 혈청 지질 수준에 미치는 영향 (The Supplementary Effects of Harvesting Lentinus edodes at Different Times on Treating Blood Pressure and Serum Lipid Levels in Spontaneously Hypertensive Rats)

  • 이성현;박홍주;조용식;조수묵;김미자
    • 한국지역사회생활과학회지
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    • 제15권2호
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    • pp.65-71
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    • 2004
  • Many studies have shown that Letinus edodes has some effect on reducing blood pressure and lipid levels of animals with high pressure and hyperlipidemia. The cost of Letinus edodes varies depending on when it is harvested, and yet there has been no data collected on the bio-functional effects of Letinus edodes harvested at different times. This study was conducted to investigate the supplementary effects of Letinus edodes harvested at different times on blood pressure and blood lipid levels of hypertensive rats. Three kinds of experimental diets - control (CO), early harvested Lentinus deodes (EL), and late harvested Lentinus edodes (LL) - were supplied to spontaneously hypertensive rats (SHR) for eight weeks. The diet intake, body weight, organ weight, and serum lipid levels were subsequently measured. No significant difference was observed in diet intake and in the respective weights of the body, liver, and epididymal fat pad among experimental groups. The levels of systolic and disastolic blood pressure were significantly lower in the LE and LL groups than those in the CO group; and the concentration of serum total cholesterol was also lower in the LE and LL groups than in the CO group. These results confirm that Lentinus edodes reduces blood pressure levels and serum total cholesterol concentration in spontaneously hypertensive rats. But the effects of Lentinus edodes did not differ significantly based on whether the Lentinus edodes was harvested early or late.

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유체 충격압력 시계열의 모델링에 관한 기초 연구 (A Fundamental Study for Time History Modeling of Fluid Impact Pressure)

  • 노인식;이재만;염철웅
    • 대한조선학회논문집
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    • 제47권2호
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    • pp.242-247
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    • 2010
  • To consider effects of essential parameters of water impact pressure on dynamic structural responses of bow bottom structures, a parametric study for a ship bottom panel is carried out. The idealized pressure time history models were assumed by triangular and rectangular shapes in time domain. The main loading parameters are duration time and peak pressure value maintaining the same impulse value. The structural models for local bottom stiffened panels of a container ship are analysed. The natural frequency analysis and transient dynamic response analysis are performed using MSC/NASTRAN. Added mass effects of contacting water are considered and the pressure distributions are assumed to be uniform in the whole water contacting surface. The effects of loading parameters on the structural responses, especially maximum displacements, are considered. Besides the peak pressure value, effects of duration time correlated with natural frequencies are thought to be the important parameters.

Effects of Pressure on Combustion Characteristics of Conical Flameholder

  • Yamamoto, Takeshi;Shimodaira, Kazuo;Kurosawa, Yoji
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.99-105
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    • 2004
  • The effects of pressure on combustion characteristics of the conical flameholder were investigated experimentally in the pressure range from 0.11 ㎫ to 0.40 ㎫. The result shows that the total equivalence ratio of lean limit becomes lower as the combustor inlet pressure rises and NOx emission is proportional to the pressure to the 0.5th power.

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극저온 정압 저널베어링의 성능해석에 관한 연구 : 난류유동, 압력강하, 가변 밀도 및 점도의 영향 (A Study on Performance Analysis of Cryogenic Hydrostatic Journal Bearings : the Effects of Turbulent Flow, Pressure Drop and Variable Liquid Properties)

  • 김성기;강지훈;김경웅
    • Tribology and Lubricants
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    • 제19권3호
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    • pp.139-145
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    • 2003
  • In this paper, static characteristics of a cryogenic hydrostatic journal bearing which has 2-rows staggered recesses are numerically analyzed. The regime of operation of this bearing is fully turbulent with large fluid inertia effects. The turbulent lubrication equation is solved under the assumption that turbulence parameters are decided by the Reynolds numbers. Pressure drop caused by inertia effect at the recess edge is considered in this analysis. Also density and viscosity of working fluid are considered as function of only pressure. Numerical results for a cryogenic Hydrostatic journal bearing show pressure distribution, load capacity, flow rate, and recess pressure. The effects of turbulent flow, pressure drop and variable liquid properties are discussed.

Kurtosis 변화에 따른 Pressure Flow Factor에 관한 연구 (Effects of Kurtosis on the Pressure Flow Factor)

  • 강민호;김태완;구영필;조용주
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제31회 춘계학술대회
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    • pp.243-250
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    • 2000
  • In the partial lubrication regime, the roughness effects are most important due to the presence of interacting asperities. An average Reynolds equation using flow factors is very useful to determine effects of surface roughness on partial lubrication. In this paper, the pressure flow factors for Gaussian and non-Gaussian surfaces are evaluated in terms of kurtosis. The effect of kurtosis on pressure flow factor is investigated using random rough surface generated numerically. The pressure flow factor increases with increasing kurtosis in partial lubrication regime(h/$\sigma$<3). As h/$\sigma$increases, the pressure flow factor approach to 1 asymptotically regardless of kurtosis.

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