• Title/Summary/Keyword: Pressure Difference

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Comparison of Atmospheric Environmental Factors between Farms with Difference in Paprika Productivity (파프리카 생산성 차이 농가 간 지상부 환경요인 비교)

  • Kim, Ga Yeong;Woo, Seung Mi;Kim, Ho Cheol
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.4
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    • pp.785-789
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    • 2021
  • Paprika productivity is different even in the same quality greenhouse and in the same region. These differences are known to due to differences in various environmental factors. This study was conducted to investigate the difference in the level of various environmental factors between high-productivity (HPF) and low-productivity (LPF) greenhouses. The largest difference between the two greenhouses in the daily or weekly average values of major environmental factors was the CO2 concentration, but the LPF was higher than the HPF, so it was not determined as a factor for the difference in productivity. Correlation analysis among 14 environmental factors showed a high correlation among irradiation or related factors in moisture. The regression coefficients of the linear regression model between vapor pressure deficit and relative humidity were -0.0202kpa in HPF and -0.0262kpa in LPF. In particular, in February and March, the vapor pressure deficit in LPF was 1.5kpa or more, and the cumulative vapor pressure deficit compared to the cumulative irradiation at the early period of cultivation increased rapidly. The reason for the low productivity in LPF is thought to be that the plant was affected by moisture stress due to high vapor pressure deficit and transpiration under low irradiation conditions in the early period of cultivation and in winter.

Comparison of Sphygmomanometer, Fully Automatic Electronic Blood Pressure Meters with Standard Digital Blood Pressure Monitor : Pilot Study (표준전자식 혈압계와 수은혈압계, 전자혈압계의 비교 선행연구)

  • Yahng, J.S.;Lim, H.K.;Cho, D.H.
    • Journal of Biomedical Engineering Research
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    • v.33 no.3
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    • pp.155-162
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    • 2012
  • Devices to measure the blood pressure of patients are being used without any calibration in a hospital. It is an important to show consistent values when any medical devices measure the same patients regardless they are sphygmomanometer or fully automatic electronic blood pressure meter. We compared sphygmomanometer and fully automatic electronic blood pressure meters with standard digital blood pressure monitor (SDBPM) to evaluate the consistency of the small healthy subjects. We measured the blood pressure from six healthy subjects (three of 20~40 years and three of 40~60 years old). Two sphygmomanometer and two fully automatic electronic blood pressure meters were used and compared with the SDBPM. Blood pressures measured from right and left arms each and were compared. All six healthy subjects showed normal blood pressure values. In general, left blood pressure values showed higher values than right side. Comparing SDBPM, with the other monitors, the systolic pressure showed ${\pm}$ 34.8% difference and ${\pm}$ 33.3% for the diastolic pressure. Correlation between SDBPM and Sphygmomanometer was 0.59~0.71, and 0.50~0.70 for fully automated digital BP monitors. It fell in grade-D when we apply the BHS(British hypertension society). AAMI(American association for the advancement of medical instrumentation) also showed unsatisfactory results for the mean value (${\leq}$ 5 mmHg) and standard deviation (${\leq}$ 8 mmHg). We tested sphygmomanometer and fully automatic electronic blood pressure meters and compared with a standard digital blood pressure monitor. All devices showed inconsistent blood pressures. A reliable calibration system is highly needed for all devices in all hospitals.

Clinical Evaluation of the Accuracy of Electronic Home Blood Pressure Measuring Devices (가정용 전자식 혈압계의 정확도에 대한 임상적 평가)

  • Choo Ji-Na
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.9 no.1
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    • pp.101-112
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    • 2002
  • Purpose: This study evaluated the accuracy of electronic devices compared with mercury sphygmomanometer. Of 132 outpatients with electronic devices. 77 who possessed oscillometric cuff devices participated in this study. Method: When the blood pressure was measured, all electronic devices were connected by means of a Y-connector to a mercury sphygmomanometer. Using the simultaneous same arm approach, each comparison was carried out three times at 2-minute intervals. Results: Compared with the mercury sphygmomanometer, the electronic devices underestimated systolic and diastolic blood pressure, respectively by $4.0{\pm}5.8mmHg$ and $2.5{\pm}67mmHg$, which satisfies the standard error range of the American Association for the Advancement of Medical Instrumentation. According to the British Hypertension Society criteria, these differences achieved C grade for both systolic and diastolic pressure. For the graphical analysis, the differences had a tendency to fulfill the permitted error limits in both diastolic and systolic blood pressure. Moreover, the purchase duration was not correlated with the accuracy of electronic devices. Conclusion: These results indicate that difference in blood pressure between electronic devices and mercury sphygmomanometer is within the standard error. Therefore, electronic blood pressure measuring devices may be useful for therapeutic self-management of hypertension.

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The Relationship of Risk Assessment Using Braden Scale and Development of Pressure Sore in Neurologic Intensive Care Unit (Braden scale을 이용한 신경외과 중환자의 욕창 위험 요인 사정과 욕창 발생과의 관계)

  • Lee, Jong-Kyung
    • Korean Journal of Adult Nursing
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    • v.15 no.2
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    • pp.267-277
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    • 2003
  • Purpose: The purpose of this study was to evaluate the applicability of braden scale to assess pressure ulcer risk patients and to identify additional risk factors of pressure sores in an neurologic intensive care unit. Method: The subjects of this study were 66 patients in neurologic intensive care units. Data was prospectively collected from Sep. to Dec., 2002. Data were analyzed by mean, percentage, t-test, chi-square, discriminant analysis using Spss pc+. Result: The results of this study were as follows: 1) There was a significant difference between scoring of braden scale and pressure ulcer development. The subscales that predicted pressure ulcer development using braden scale only were sensory perception, moisture, mobility, friction & shear. By using these subscales, sensitivity was 86.7%, and specificity was 61.1%, and total hit ratio was 72.7%. 2) Additional pressure ulcer risk factors which showed significance for discriminating two group were protein, albumin, gender, level of consciousness, pattern of bowel elimination. By using the combination of these additional risk factors in addition to the braden scale, total hit ratio increased to 84.8%. Conclusion: This data suggest that albumin, protein, gender, level of consciousness, pattern of bowel elimination in addition to the braden scale should be included in the pressure sore assessment tool.

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A Study of Transitional Performance with Change of Inlet Pressure in Liquid Propellant Rocket Engine (액체로켓엔진에서 입구압 변화에 따른 엔진 성능 변화 고찰)

  • Moon, Yoon-Wan;Park, Soon-Young;Seol, Woo-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.05a
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    • pp.103-106
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    • 2008
  • In this work it was studied that the effect on sub-component of engine considering change of engine inlet pressure caused by variable acceleration during flight of launcher. Also the transitional performance was predicted according to variable acceleration. Engine inlet pressure was defined as summation of propellant head in tank, ullage pressure and pressure difference of line, etc. Therefore consumption of propellant and acceleration of launcher led to change of engine inlet pressure, which affected on discharge pressure of pumps. This effect changed mass flow rate of gas generator and main combustor hence it was observed that engine performance was changed definitely.

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A Study on the Variables Influencing Female College Students' Body Shame and Appearance Change Intention: Comparison of Korea, China and Germany (여대생의 신체수치심과 외모변경의도에 영향을 미치는 변인 연구: 한국, 중국과 독일의 비교)

  • Hong, Keum-Hee
    • Fashion & Textile Research Journal
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    • v.13 no.4
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    • pp.523-530
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    • 2011
  • This study aims to make a comparison between variables influencing female college students' body shame and appearance change intention in individualist culture(Germany) and collectivist culture(Korea, China), that which variable among individual's physical character(BMI), psychological character(public self-image), and sociocultural pressure has the biggest influence in each culture. The findings of the research are as follows. 1. The German group of female college students had the highest BMI, and there were no difference between Korean and Chinese group. Public self-consciousness, sociocultural pressure, ideal appearance attitude, body shame, and appearance change intention were highest in Korea and lowest in Germany. 2. The variables that affected body shame were powerful in the order of sociocultural pressure, appearance internalization, BMI, and appearance awareness in the Korean group of female college students. In the Chinese group, the order was sociocultural pressure, appearance internalization, and public self-consciousness. On the contrary, in the German group the order was appearance internalization, appearance awareness, sociocultural pressure, and public self-consciousness. 3. The variables that affected appearance change intention were powerful in the order of sociocultural pressure, body shame, and appearance awareness in the Korean group of female college students. In the Chinese group, the order was sociocultural pressure, body shame, and appearance awareness, and in the German group, the order was appearance internalization, body shame, and BMI.

Study on the Injection Characteristics using Injection Rate in a Direct-injection Gasoline Injector with Multi-hole (분사율을 이용한 직접 분사식 다공 가솔린 인젝터의 분사특성 연구)

  • Park, Jeonghyun;Shin, Dalho;Park, Su Han
    • Journal of ILASS-Korea
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    • v.21 no.1
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    • pp.20-28
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    • 2016
  • This paper presents an experimental study on the GDI injector with Bosch method. The injection characteristics, such as the injection quantity, the injection rate, the maximum velocity of the nozzle exit and the injection delay were studied through the change of the injection pressure, the tube pressure and energizing duration in injection rate measurement device using nheptane. The injection quantity is increased by increasing injection pressure, decreasing tube pressure or increasing energizing duration. As the difference of the injection quantity changed, the shape of injection rate was moved with a constant form. The maximum velocity of the nozzle exit showed a tendency to increase as the injection pressure is increased. However, tube pressure did not affect. Overall, it was confirmed that the closing delay is longer than the opening delay in all conditions. As the injection pressure increased, the result has a tendency to decrease the closing delay, it did not affect the opening delay. Reduction of the closing delay showed the reduction of the injection duration. the tube pressure and energizing duration did not affect the injection delay (opening delay, closing delay).

Estimation of Non- Invasive Blood Pressure Using Peripheral Plethysmograph (말초혈관 혈류 측정을 이용한 비관혈적 혈압 추정법에 대한 연구)

  • Jeong In-cheol;Shin Tae-min;Yoon Hyung-Ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.8
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    • pp.504-509
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    • 2005
  • This paper presents a new method for obtaining the noninvasive and unrestrained blood pressure readings noninvasively and unrestrainedly using based on reflected wave arrival time(RAT) in the volume of pulse. Since this new method employs only volume pulse, is more rapider and simpler than the method using pulse transit time(PTT) because it only employs the volume of pulse. Blood pressure, PTT and RAT were acquired from 15 healthy subjects. Each subjects were performed forty trials of each measurement. As a result of those trials, the mean error between oscillometric and RAT measurements for systolic blood pressure was $4.55\pm5.64mmHg$. This result showed quite equal with the mean error between oscillometric and PPT measurf:ments, $4.22\pm5.30mmHg$, However, it was not obtained a satisfactory result in the relativity of oscillometric to both RAT and PPT measurements for diastolic blood pressure because of personal difference. To conclude, the method of systolic blood pressure estimation noninvasively and unrestrainedly using by RAT may be used as the method by PTT. Nevertheless, additional studies would be necessary for the RAT/PTT estimation of diastolic blood Pressure measurement.

Study on the pressure self-adaptive water-tight junction box in underwater vehicle

  • Huang, Haocai;Ye, Yanying;Leng, Jianxing;Yuan, Zhuoli;Chen, Ying
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.4 no.3
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    • pp.302-312
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    • 2012
  • Underwater vehicles play a very important role in underwater engineering. Water-tight junction box (WJB) is one of the key components in underwater vehicle. This paper puts forward a pressure self-adaptive water-tight junction box (PSAWJB) which improves the reliability of the WJB significantly by solving the sealing and pressure problems in conventional WJB design. By redundancy design method, the pressure self-adaptive equalizer (PSAE) is designed in such a way that it consists of a piston pressure-adaptive compensator (PPAC) and a titanium film pressure-adaptive compensator (TFPAC). According to hydro-mechanical simulations, the operating volume of the PSAE is more than or equal to 11.6 % of the volume of WJB liquid system. Furthermore, the required operating volume of the PSAE also increases as the gas content of oil, hydrostatic pressure or temperature difference increases. The reliability of the PSAWJB is proved by hyperbaric chamber tests.

Study on Development of Inducing Airflow Duct System for Kitchen Hood Using Ejector Method (이젝터 기술을 활용한 주방후드용 기류유인 덕트 시스템의 개발에 관한 연구)

  • Son, Yu-Ra;Hong, Seong-Gyu;Yang, Jeong-Hoon
    • Journal of the Korean Solar Energy Society
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    • v.39 no.6
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    • pp.27-40
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    • 2019
  • Kitchen hoods are limited in discharging all contaminants produced during cooking. Contaminants that have not been discharged can rise to the upper part of the kitchen and become stacked. To solve this problem, there is a way to increase the air volume of the kitchen hood, but there are limits, so a new system is required. This study proposes the Duct System (IADK : Inducing Airflow Duct system for Kitchen hood )through 3D printers and experiments. To do this, the pressure is measured to verify the three levels of air volume provided by the kitchen hood. To check the degree of loss of flow in the existing kitchen hood system, install flexible ducts alone to measure the pressure. Change the internal diameter and type of connection of the IADK and measure the pressure. The air pressure, static pressure difference, and loss factor are calculated and analyzed using the pressure measured through the experiment.