• Title/Summary/Keyword: Pressure Difference

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Measurement of electron density of atmospheric pressure Ar plasma jet by using Michelson interferometer

  • Lim, Jun-Sup;Hong, Young June;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.195.1-195.1
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    • 2016
  • Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

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Comparative Study About The Indirect Blood Pressure (measured by different Instruments and Methods) (측정도구와 방법에 따른 간접혈압측정치의 비교연구)

  • Suh Gil-Hee
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.1 no.1
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    • pp.51-68
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    • 1994
  • One aim of this study was to find out the difference of indirect blood pressure between the types of instruments. The difference of indirect blood pressure was measured with mercury sphygomomanometer and electronic blood pressuremeter. Another was to determine the difference of indirect blood pressure according to width of cuff and site of cuff. Indirect blood pressures were measured with the diaphragmatic side of sphygomomanometer. The subjects were 40 female volunteers, whose arm circumferences were from 22 to 34cm. The data were analyzed by SPSS-PC program and pared t-test was used. The results are summarized as follows ; 1. Mercury sphygomomanometer systolic pressure was higher(average 2.20mmhg) than electronic blood pressuremeter. It was statistically significant(p=0.026). 2. The value of Mercury sphygomomanometer diastolic pressure was lower(2.00mmhg) than electronic's. It was statistically significant(p=0.03) 3. In the mercury sphygomomanometer systolic pressure, the value of standard cuff($12{\times}23cm$) was higher(2.40mmhg) than large one's($14{\times}45cm$). It was statistically significant(p=0.007). 4. In diastolic pressure(K4), the value of standard cuff was higher(0.65mmhg) than large cuff's. It was not statistically significant(p=0.481). In K5, the value of standard cuff($12{\times}23cm$) was higher(0.55mmhg) than large cuff's. It was not statistically significant(p=0.541). 5. Difference according to site of showed that the values of systolic pressure over elbow joint were higher(20.00mmhg, 26.45mmhg) than ones at site of elbow joint. It was significant statistically(p=0.000) and clinically. 6. The values of diastolic pressure(K4) over elbow joint were higher(17.10mmhg, 21.60mmhg) than ones at site of elbow joint. It was significant statistically (p=0.000) and clinically. The values of K5 over elbow joint were higher(17.25mmhg, 22.15mmhg) than ones at site of elbow joint. It was significant statistically(p=0.000) and clinically. I think similar studies about indirect blood pressure according to diseases and positions are necessary. In addition, similar studies, are required about accuracy of method electronic blood pressuremeter according to site of mesurement.

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The Study on the Solution of Stack effect in the Vertical shaft of High-rise Buildings (고층건축물 수직 샤프트 연돌효과 해소방법에 대한 연구)

  • Kim, Jin-Soo;Chang, Hee-Chul
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.242-245
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    • 2007
  • Stack effects occurred in the stairwell, an important evacuation means of the high-rise building, give a big impact on stairwell pressure difference distribution and it could obstruct evacuation from the building, so should be controlled within proper range. Computer simulation was conducted with CONTAMW2.4 to find the solution of stack effects of the high-rise building. It was able to solve the imbalance pressure difference with a pressurization and a depressurization supplied by fans on higher and lower parts of the stairwell.

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Optimum Design of a Micro-fluidic Oscillator (유체 진동자의 최적 설계)

  • 노유정;윤성기;김문언
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.1
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    • pp.22-30
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    • 2004
  • A micro-fluidic oscillator is used to control a linear actuator in a dynamic microsystem. The pressure difference at its two output ports causes the linear actuator to move, and it is a standard of judging the performance of the oscillator. The performance can be improved by optimizing the geometry of the oscillator, which has to enable fluid jet to switch at low inlet velocity. For this, in this study the relationship between the pressure coefficient (difference) and geometric parameters is obtained through the analysis using the software FLUENT. From the results the optimized model that maximize the output pressure difference is obtained by using a cyclic coordinate method that is one of optimization methods. As a result not only the performance is improved, but also the working range is more widen.

Direct Simulation of Acoustic Sound by the Finite Difference Lattice Boltzmann Method (차분격자볼츠만법에 의한 유체음의 직접계산)

  • Kang, Ho-Keun;Ro, Ki-Deok;Lee, Young-Ho
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1827-1832
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    • 2003
  • In this research, the simulation method for acoustic sounds by a uniform flow around a two-dimensional circular cylinder by using the finite difference lattice Boltzmann model is explained. To begin with, we examine the boundary condition which determined with the distribution function $f_i^{(0)}$ concerning with density, velocity and internal energy at boundary node. Very small acoustic pressure fluctuation, with same frequency as that of Karman vortex street, is compared with the pressure fluctuation around a circular cylinder. The acoustic sound' propagation velocity shows that acoustic approa ching the upstream, due to the Doppler effect in the uniform flow, slowly propagated. For the do wnstream, on the other hand, it quickly propagates. It is also apparently the size of sound pressure was proportional to the central distance $r^{-1/2}$ of the circular cylinder. The lattice BGK model for compressible fluids is shown to be one of powerful tool for simulation of gas flows.

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A Study on Materialism of University Students (대학생의 물질주의 가치관에 대한 연구)

  • Song, Soon;Shin, Hyoun-Shill
    • Korean Journal of Human Ecology
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    • v.11 no.3
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    • pp.223-235
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    • 2002
  • The purpose of this study was to examine the influences of the materialism of university students. The data were collected for 331 university students. The data were analyzed by the package of SPSS program. The methods of analyses included basic descriptive categorical analysis (frequencies, means, percentages) as well as t-test, one way ANOVA, and multiple regressions. To summarize major findings from the analysis: (1) A significant difference was found in the materialism of university students by the socio-economic variables such as the amount of pocket money. (2) A significant difference was found in the materialism of university students by more self-esteem than life satisfaction. (3) A significant difference was found in the materialism of university students by parent's materialism and competitive achievement pressure. (4) According to the multiple regression analysis, it was found that the materialism of university students was influenced by the order of self-esteem, parent's materialism and competitive achievement pressure.

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Wells Turbine for Wave Energy Conversion -Effect of Trailing Edge Shape-

  • Takasaki, Katsuya;Tsunematsu, Tomohiro;Takao, Manabu;Alam, M M Ashraful;Setoguchi, Toshiaki
    • International Journal of Fluid Machinery and Systems
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    • v.9 no.4
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    • pp.307-312
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    • 2016
  • The present study reported of the use of special shaped blade to reduce the difference in pressure across the Wells turbine for wave energy conversion. The blade profile was composed of NACA0020 airfoils and trailing edge was notched like chevron. Experiments were performed investigating the influence of trailing edge shape on the turbine performance. Four notch depths were used to investigate the effect of depth of cut on the turbine performance. As results, by placing a notch-cut at the trailing edge of the blade, it was possible to reduce the pressure difference across the turbine without lowering the efficiency. In addition, the pressure difference substantially reduced at a constant rate with the increase of the cut ratio.

The Effects of Manual Therapy on Lower Extremity Alignment in Pelvic Malalignment

  • Jeon, Chang Keun;Han, Se Young;Yoo, Kyoung Tae
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.3
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    • pp.1543-1548
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    • 2018
  • The purpose of this study was to analyze the effects of manual therapy on lower extremity alignment in pelvic malalignment. The subjects were 20 adults with pelvic malalignment. They were divided into two groups: manual therapy group (n=10) and stretching exercise group (n=10). Each group performed the intervention two times per week for 4 weeks. The lower extremity alignment was measured by pelvic deviation, functional leg length inequality, and plantar pressure distribution, which were measured between pre- and post-test. In the result of pelvic deviation, there was a significant difference between the pre- and post-test of the manual therapy group and stretching exercise group. In the result of the functional leg length inequality, there was a significant difference between the pre- and post-test of the manual therapy group. In the result of plantar pressure distribution, there was a significant difference between the pre- and post-test of the manual therapy group. These findings suggest manual therapy improves the pelvic deviation, functional leg length inequality, and plantar pressure distribution in the pelvic malalignment.

A Study on the Clothing Pressure variation according to arm movement and ease of basic pattern (신체동작과 의복여유분에 따른 의복압에 대한 탐색적 연구 -견갑골$\cdot$상지를 중심으로-)

  • Cho Jung Mee;Kim Hae Kyuong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.1
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    • pp.11-19
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    • 1987
  • The objectives of this study were: 1. To investigate the relationship between arm movement and clothing pressure in the upper arm and shoulder blade area. 2. To find out the relationship between ease of basic pattern and clothing pressure in the upper arm and shoulder blade area. 3. To study any interaction between arm movement and ease of clothing on the clothing pressure. This study was an experimental research using the measuring devices of clothing pressure. The subjects were the unmarried college women. Arm movements were 3 types($45^{\circ}$, $90^{\circ}$, $135^{\circ}$) to the horizontal direction. The ease of basic pattern in the breast was 3 types(4 cm, 6 cm, 8cm). The statistical analyses used in this study included mean, standard deviation and one-way analysis of variance. The results obtained from this research were as follows; 1. The whole clothing pressure increased as the angle of the arm movement increased. Part of upperarm and shoulder blade above axillar gave high clothing pressure while part of upperarm and shoulder blade above upper breast, low pressure. Difference between highest clothing pressure and lowest clothing pressure increased as the arm movementdid. 2. The whole clothing pressure increased as the ease of the basic pattern in breast decreased. No matter how the ease of basic pattern in the breast area varied, the Points where generally showed high and low pressure were identical. 3. The whole arm pressure increased as the movement angle increased and the ease of pattern in breast area decreased. Difference between highest clothing pressure and lowest clothing pressure increased as the movement angle increased and the ease decreased.

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A Study on the Prevalence Rate of Hypertension and the Actual Conditions of Control (일 지역 성인의 고혈압 유병률 및 관리 실태)

  • Kim, Hyeon-Ok
    • Research in Community and Public Health Nursing
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    • v.10 no.1
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    • pp.154-172
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    • 1999
  • In order to analyse the prevalence rate of hypertension and the actual conditions of control, we selected five districts out of eleven eups and myuns in Chinan Country. We administered structured questionaries to 309 adults above the age of 40, computerized the data using SPSS - PC+. More than 40.1% of adults over 40 in Chinan County have health disorders ranging from high blood pressure to hypertension including alert high blood pressure at 36.2%, relatively high. Among general characteristics, differences in the rate of hypertension were influenced by age, occupation and places of residence. Over 71 who are engaged in agriculture, who don't have jobs, who reside in Sungsu, Jungchun, Chinan-eup all have higher hypertension rates than other groups. Accordingly, the control of hypertension should be focused on these people. As a result of the control of blood pressure, the survey showed 93.0% of the subjects were checked mainly at hospitals clinics, health centers subhealth centers and community health posts more than once a year, relatively high level of blood pressure management. However, the difference between their blood pressure measurements at ordinary times and the level of blood pressure at the time of research was quite considerable. Only 47.3% of the subjects diagnosed with high blood pressure and 70.3% of the subjects with normal blood pressure recognized their blood pressure accurately 52.7% of the subjects diagnosed with high blood pressure showed errors in understanding their blood pressure at normal times. Because these errors can cause problems in the control of blood pressure, proper management should be executed through a systematic examination. As a result of the high blood pressure control condition, the average period of hypertension was 74.5( ${\pm}92.8$) months, 92.3% of the subjects were diagnosed with high blood pressure at hospitals clinics, health centers subhealth centers community health posts, but only 29.5% were examined after a general check up on high blood pressure was completed. 70.5% were diagnosed with high blood pressure only after measuring their blood pressure. 14.1% of the subjects were hospitalized because of falls influenced by high blood pressure. 33.3% attended hospitals and health centers regularily for medical treatment and this shows how low the rate of the control of blood pressure. Most people did not undergo medical treatment, because they had no painful symptoms (46.7%), they didn't need to take the medicine(28.9%), or they forget to take the medicine(20.0%). These problems in the control of hypertension were discovered in the process of diagnosing high blood pressure at health medical institutions. Many people did not recognize the need for consistent control of blood pressure. That is, although the diagnosis for high blood pressures performed at hospitals clinics, health centers subhealth centers and community health posts, was 92.3%, more than 70.5% of the subjects were not examined completely with regard to blood pressure. Accordingly, heath medical institutions must diagnose high blood pressure not only by only measuring blood pressure but also by using systematic process of examination. As for the people diagnosed with high blood pressure, one should perform consistent medical approaches and help them to recognize the importance of the continuous control of blood pressure through subject-oriented education. Problems the subjects experienced were the following numbness in the limbs easily paralyzed stitches in their shoulders which felt painful, stiff necks, occiputs felt heavy, headaches when they got up in the morning, felt dizzy when standing and moving their heads and poor eyesight. The rate of knowledge related to high blood pressure was 78.7 points, comparatively low. Whether they had normal blood pressure or hypertension made no difference. These results are not desirable. Adult-oriented education forgot the prevention and management of high blood pressure should be implemented. Hypertensive-oriented education should be especially reinforced. Because there was a difference in the level of knowledge according to age, academic career, occupation or place of residence, education related to hypertension should be intensified and focused on those over the age of 71 those who did not attend school, those who do not have jobs and are engaged in agriculture and residents living in Bugui, Jungchun regions. The degree of healthy life practice in hypertensives is poor, particularly weight control, as opposed to people who have normal blood pressure. It makes no difference in smoking, the amount of daily smoking, drinking, the control of salt because each result means that they are not practicing healthy life or modifying their life-style. The development and programs to improve a healthy life should be executed.

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