• 제목/요약/키워드: Pressure Resistance

검색결과 2,184건 처리시간 0.029초

근육이완을 포함한 저항운동 프로그램이 농촌 여성노인들의 혈압, 운동빈도 및 체력에 미치는 효과 (Effects of Resistance Exercise Combined to Relax Therapy in Blood Pressure, Frequency of Exercise and Physical Fitness in elderly Women in Rural District)

  • 송민선;이중철;김수근;김남초
    • 성인간호학회지
    • /
    • 제21권5호
    • /
    • pp.458-467
    • /
    • 2009
  • Purpose: This study was object to the effects of a resistance exercise combined with relaxation therapy on blood pressure, frequency of exercise and physical fitness in elderly women. Methods: Seventy three elderly women participated in an exercise program for 12 months. The exercise program consisted of stretching, massage and resistance training using thera-bands twice a week and 50 minutes in every sessions each week. Repeated measures ANOVA were performed using SAS. Results: After the exercise program there was a significant difference in systolic blood pressure, frequency of exercise, body fat, sitting to standing, walking 2 minutes, sitting on a chair and reaching, and standing on one leg with eyes opened. After 6 months, there was a significant decrease in systolic blood pressure and significant increase in frequency of exercise, body fat, sitting to standing and standing on one leg with eyes opened. In 12 months, there was a significant increase in body fat, 2 minutes walking, and sitting in a chair and reaching. Conclusion: Resistance exercise combined with muscle relaxation therapy would have a positive effect on elderly women. We found that it was helpful for the elderly women in terms of physical fitness.

  • PDF

전도성 다공성 구조 압력감지소자 (Pressure Sensitive Device Using Conductive and Porous Structures)

  • 소혜미;박철민;장원석
    • 대한기계학회논문집B
    • /
    • 제38권7호
    • /
    • pp.601-605
    • /
    • 2014
  • 일반적으로 표면적/부피비가 큰 전도성 다공체는 수퍼캐패시터의 전극이나 흡수제, 유연히터 등의 다양한 분야에 적용되어 왔다. 본 논문에서는 이러한 전도성 다공성 구조의 역학적 전기적 특성을 이용하여 고감도 압력센서를 구현하였다. 탄소나노튜브 용액에 스펀지를 적셔 다공체에 전도성을 부여하였으며, 압력에 따른 전도성 다공체의 저항 변화를 측정하였다. 전도성 스펀지에 압력이 가해졌을때, 각각의 탄소나노튜브들은 서로 맞붙게 되어 저항이 최대 20%까지 줄어듦을 확인하였다. 부드럽고 탄성력이 뛰어난 탄소나노튜브 스폰지는 반복적인 압축실험에도 모양의 변형 없이 매우 빠르게 안정화되고 일정한 저항변화를 확인할 수 있었다. 또한 스펀지 압력소자를 유연소자에 적용하기 위하여 탄소나노튜브 트랜지스터와 연결하여 외부압력에 따른 전기적 특성변화를 측정하였다.

중.소형 연미기의 성능평가 및 성능개선에 관한 연구(II) - 중형 연미기에 대하여 - (Performance Evaluation and Improvement of Medium and Small Scale Rice Polishers(II) - medium scale rice polisher -)

  • 정종훈;권홍관
    • Journal of Biosystems Engineering
    • /
    • 제23권5호
    • /
    • pp.445-456
    • /
    • 1998
  • This study was carried out to evaluate the performance of a medium scale rice polisher of 2.5 t/h and to improve its performance for producing the clean rice with high quality. The maximum internal pressure, broken rice ratio. whiteness in the rice polisher were investigated, and the effects of outlet resistance, water spraying rate, shaft revolution speed and rice moisture content on the polishing performance were analyzed to find out proper operating conditions. The conclusions of this study were as follows: 1. In the performance evaluation of the polisher, the broken rice ratio increment of 0.1%, the max. internal pressure of about 11 N/${cm}^2$, and whiteness increment of 2.2~3.7 resulted at the conditions of 20 PS driving power, 950 rpm, 150 cc/min water spraying rate, 44.1 Nㆍcm outlet resistance and about 15% rice moisture content. 2. Though max. internal pressure and whiteness at the 17% rice moisture content were higher than those at the 15% moisture content under the same operating conditions of the polisher, but the broken rice rate at the 17% moisture content was absolutely low compared with that at 15% moisture content. The water spraying effect to reduce broken rice and to increase whiteness was much significant at the 15% moisture content not significant at 17% moisture content. 3. The main parameter of the performance was outlet resistance, and low resistance of about 44.1 Nㆍcm was recommended at the polisher. 4. The proper water spraying rate in the polisher was about 150 cc/min. 5. As the shaft revolution speed decreased from 950 rpm and 800 rpm to 650 rpm, the broken rice ratio increased and whiteness decreased. 6. As the driving power of the polisher increased from 20 PS to 30 PS, the max. internal pressure decreased by about 1~2.5 N/${cm}^2$ and whiteness increased by about 1~2, but the broken rice rate was not changed. 7. The proper operating conditions of the polisher seemed to be the revolution speed of 800-950 rpm, the water spraying rate of about 150 cc/min, the oulet resistance of about 44.1 N.cm and 30 PS driving power.

  • PDF

Zr-2.5Nb 압력관의 휘어진 CT시편으로 측정한 J 저항곡선의 정확도에 관한 연구 (A Study on Accuracy of J-Resistance Curves Measured with Curved Compact Tension Specimen of Zr-2.5Nb Pressure Tube)

  • 윤기봉;박태규;김영석
    • 대한기계학회논문집A
    • /
    • 제27권11호
    • /
    • pp.1986-1996
    • /
    • 2003
  • Methodology based on the elastic-plastic fracture mechanics has been widely accepted in predicting the critical crack length(CCL) of pressure tubes of CANDU nuclear plants. A conservative estimate of CCL is obtained by employing the J-resistance curves measured with the specimens satisfying plane strain condition as suggested in the ASTM standard. Due to limited thickness of the pressure tubes the curved compact tension(CT) specimens taken out from tile pressure tube have been used in obtaining J-resistance curves. The curved CT specimen inevitably introduce slant fatigue crack during precracking. Hence, effect of specimen geometry and slant crack on J-resistance curve should be explored. In this study, the difference of J integral values between the standard CT specimens satisfying plane strain condition and the nonstandard curved CT with limited thickness (4.2mm) is estimated using finite element analysis. The fracture resistance curves of Zr-2.5Nb obtained previously by other authors are critically discussed. Various finite element analysis were conducted such as 2D analysis under plane stress and plane strain conditions and 3D analysis for flat CT, curved CT with straight crack and curved CT with slant crack front. J-integral values were determined by local contour integration near the crack tip, which was considered as accurate J-values. J value was also determined from the load versus load line displacement curve and the J estimation equation in the ASTM standard. Discrepancies between the two values were shown and suggestion was made for obtaining accurate J values from the load line displacement curves obtained by the curved CT specimens.

공력 저항 측정기를 이용한 방풍펜스 방진막의 공기 투과 저항력 측정 (Measurement of Aerodynamic Properties of Screens for Windbreak Fence using the Apparatus for Testing Screens)

  • 김락우;이인복;홍세운;황현섭;손영환;김태완;김민영;송인홍
    • 한국농공학회논문집
    • /
    • 제55권6호
    • /
    • pp.145-154
    • /
    • 2013
  • Recently, damage occurrence by wind erosion has been increasing in society. In times past, such problems only took place in desert area ; however, in recent years, the wind erosion problem is spreading out to agricultural land. Wind erosion in agricultural land can cause loss of loam soils, the disturbance of the photosynthesis of the crop fields and serious economic losses. To overcome the mentioned problems, installation of windbreak fence can be recommended which function as disturbing strong wind and wind erosion. However, there is still no proper guideline to install the windbreak fence and the installation used to rely on the intuition of the workers due to the lack of related studies. Therefore, this study measured the aerodynamic resistance of screens of the windbreak fence using the apparatus for testing screens. The apparatus for testing screens was designed to measure pressure loss around the screen. Measured pressure loss by wall friction compensated for pressure loss to calculate the aerodynamic resistance of screens. The result of pressure loss by regression analysis derived the aerodynamic coefficient of Darcy-Forchheimer equation and power law equation. The aerodynamic resistance was constant regardless of the overlapped shape when the screen was overlapped into several layers. Increasing the number of layers of the screen, internal resistance increased significantly more, and pressure loss caused by the screen also increased linearly when the wind speed was certain conditions, but permeability had no tendency. In the future, the results of this study will be applied to the computational fluid dynamics simulation. The simulation models will be also validated in advance by wind tunnel experiments. It will provide standard of a design for constructing windbreak fence.

Effect of Difference in Warm-Up Intensity During 75%1RM Bench Press Exercise on Number of Repetitions, Total Work, and RPP

  • Jeong, Hwan Jong;Kim, Ki Hong
    • International Journal of Internet, Broadcasting and Communication
    • /
    • 제13권3호
    • /
    • pp.130-136
    • /
    • 2021
  • The purpose of this study was to investigate the effect of the intensity of warm-up exercise on the physiological response and exercise performance during resistance exercise. For this purpose, 8 male college students with at least 1 year of experience in resistance movement were selected. The warm-up condition was set to NON condition (preparatory exercise not performed), 3 set condition, 6 set condition, and 9 set condition, and the intensity was different for each set. After warm-up, 75% 1RM of main exercise was performed, and blood pressure and heart rate were measured immediately after exercise to measure RPP. The number of repetitions and total work for each condition were measured as the number of repetitions and momentum during the main exercise. The measured data were analyzed by repeated measures two-way ANOVA. As a result, although there was no difference in Rate Pressure Product according to the warm-up conditions, the number of repetitions and total amount of exercise showed the highest in the 3-set condition. Therefore, it is thought that the number and intensity of warm-up exercises should be set appropriately during resistance exercise, and warm-up of 3 sets or more during resistance exercise is thought to decrease exercise performance.

궤도차량의 야지기동성 평가와 토지특성의 영향 (Off-road tractive performance of tracked vehicles and the effects of soil parameters)

  • 김진우
    • 오토저널
    • /
    • 제13권4호
    • /
    • pp.76-84
    • /
    • 1991
  • The off-road tractive performance of tracked vehicles can be evaluated in terms of soil thrust, motion resistance and drawbar pull. The ability to predict accurately ground pressure distribution under track is of importance since the vehicle sinkage and motion resistance are closely related to it. While the formulation of the method for predicting ground pressure distribution follows closely in spirit the ideas outlined for the terrain with linear pressure- sinkage relation case by Garber and Wong, the analysis of various terrain stiffness is magnified by numerical implementation procedure. The effects of soil parameters on tractive forces can be introduced through the terrain-track interaction such as pressure-sinkage and shearing characteristics. It is illustrated by determining the drawber pull-slip relation and corresponding ground pressure distribution for the terrains typically chosen and by comparing the results with the conventional ones based on normal ground pressure. The factorial experiment method is finally adopted for checking the sensitivity of the values of soil parameters on the drawbar pull.

  • PDF

Suction Drain 공법에서 양방향 압력재하에 의한 효율 평가에 관한 연구 (A study on evaluation of duplex loading pressure in Suction Drain Method)

  • 안동욱;채광석;한상재;윤명석;김수삼
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2010년도 춘계 학술발표회
    • /
    • pp.1256-1263
    • /
    • 2010
  • Suction Drain Method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the Vertical Drain Board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or Preloading Method. In this study, ground improvement efficiency of suction drain method was estimated when duplex loading pressure with vacuum and pressure. During suction drain method process, surface settlement and pore pressure were monitored, and cone resistance test as well as water content were also measured after the completion of Suction Drain Method treatment.

  • PDF

주기적인 외부 압력변동에 의한 자연환기성능 연구 (A Study on Natural Ventilation Performance by Periodic Outdoor Pressure Fluctuations)

  • 이승연;염철민;한화택
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2005년도 동계학술발표대회 논문집
    • /
    • pp.27-32
    • /
    • 2005
  • This paper investigates the effects of outdoor pressure fluctuations on natural ventilation through openings of a building envelope. The ventilation airflow rate depends on the magnitude and the period of the pressure fluctuations, the size of the opening compared to the space volume, and the resistance characteristics of the opening. Non-dimensional parameters have been derived, which determine indoor pressure responses due to outdoor pressure fluctuations. The flow regions are categorized into synchronized region, opening resistance region, and transition region depending on the non-dimensional parameters.

  • PDF

커프 압력 조절에 따른 혈류량 변화 평가를 위한 임피던스법의 구현 (Implementation of Impedance Method to Estimate Blood Flow Variation with Cuff Pressure Change)

  • 정도운;배진우;손정만;예수영;최병철;남기곤;김철한;전계록
    • 센서학회지
    • /
    • 제13권6호
    • /
    • pp.462-472
    • /
    • 2004
  • In this study, we measured the blood flow on arm by non-invasive method and implemented a system to measure variation of the blood flow by estimating bio-electrical impedance and arterial pressure according to cuff pressure. The implemented system measured impedance variation according to pressure variation applied by artificial cuff pressure on the measuring position. The system consisted of pressure measuring part and impedance measuring part using 4-electrode method. Pressure measuring part was composed of semiconductor pressure sensor and electronic circuit for signal processing of sensor output signal. In addition, impedance measuring part was composed of constant current source circuit and lock-in amplifier for detecting impedance signal. We conducted experiments of impedance measuring part using standard resistance for performance evaluation of the implemented system. In addition we experimented to estimate variation of the blood flow by measuring impedances of the experimental group. We estimated ratio of the blood flow resistance using mean arterial pressure and variation of the blood flow. As a result the ratio of the blood flow resistance and variation of blood flow were in an inverse relationship with each other and the correlation coefficient was -0.96776.