• Title/Summary/Keyword: peak flow rate

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Application of peak load for industrial water treatment plant design (공업용수 정수장 설계시 첨두부하 적용방안)

  • Kim, Jinkeun;Lee, Heenam;Kim, Dooil;Koo, Jayong;Hyun, Inhwan
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.3
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    • pp.225-231
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    • 2016
  • Peak load rate(i.e., maximum daily flow/average daily flow) has not been considered for industrial water demand planning in Korea to date, while area unit method based on average daily flow has been applied to decide capacity of industrial water treatment plants(WTPs). Designers of industrial WTPs has assumed that peak load would not exist if operation rate of factories in industrial sites were close to 100%. However, peak load rates were calculated as 1.10~2.53 based on daily water flow from 2009 to 2014 for 9 industrial WTPs which have been operated more than 9 years(9-38 years). Furthermore, average operation rates of 9 industrial WTPs was less than 70% which means current area unit method has tendency to overestimate water demand. Therefore, it is not reasonable to consider peak load for the calculation of water demand under current area unit method application to prevent overestimation. However, for the precise future industrial water demand calculation more precise data gathering for average daily flow and consideration of peak load rate are recommended.

Clinical Outcome of Educational Program Using Self-monitoring of Peak Expiratory Flow Rate for Asthma Patients (천식 환자에 있어서 최대호기 유속의 자가 모니터링을 이용한 복약지도의 유용성)

  • Lee, Myung Bok;Shin, Hyun Taek;Kim, Sun Young
    • Korean Journal of Clinical Pharmacy
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    • v.9 no.2
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    • pp.97-102
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    • 1999
  • The effects of pharmacist's intervention for asthma patients using self-monitoring of peak expiratory flow rate in medication teaching model was evaluated for 3 months in improving clinical outcomes including emergency visits, hospitalizations, antibiotics use, symptoms and sleep disturbance. Twenty seven patients were enrolled in study and twenty three patients completed the follow-up schedules. The selected patients were given the pre-designed instruction for medication including appropriate use of medication, metered-dose inhaler(MDI) technique, identifying and controling asthma triggers and recognizing early signs of deterioration. There were significant improvements in clinical outcomes, in terms of emergency visits, hopitalizations, antibiotics use, symptoms and sleep disturbance. There were also significant improvements in the MDI use, environmental control, and medication knowledges. There was a progressive increase in peak expiratory flow rate during the three-month intervention. In conclusion, pharmacist's intervention using self-monitoring of peak expiratory flow rate has a significant impact on improving clinical outcomes in asthma patients.

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Effect of Discharge Gas on the Electrical Characteristics of the Glow Discharge Plasma for the Gas Chromatographic Detector (글로우방전 가스크로마토그라프 검출기에서 방전가스의 영향)

  • 박현미;강종성;김효진
    • YAKHAK HOEJI
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    • v.39 no.5
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    • pp.480-486
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    • 1995
  • The change in discharge current of a glow discharge has been shown the potential sensitive detector for gas chromatography. To investigate the effect of carrier gas on the electrical characteristics of the discharge and the peak response, the discharge pressure, gas flow rate, and discharge gap have been studied. The discharge gas included the Ar, He, and N$_{2}$. The gas flow rate has been found one of the important parameters to affect both the electrical characteristics and the peak response.

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Design Flow Velocity Changes According to the Design Flow Determination Methods in the Sanitary Sewer (오수관 설계유량 산정법이 설계유속에 미치는 영향)

  • Hyun, In-hwan;Won, Seung-hyun;Kim, Hyung-jun;Lee, Che-in
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.6
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    • pp.749-757
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    • 2005
  • The present study analyzed actual cases of designed flow estimation method and designed flow rate of sewage pipe lines. In order to examine the effects of peak-hour demand factor estimation with given daily highest peak loading, we analyzed its effects on designed flow rate with changing the peak-hour demand factor from 2.0 to 10.0. The results of this study are as follows. When reviewing the recent designs, we found that 59.4% of pipe line with 250mm and 300mm diameter, which fall under minimum allowable pipeline did not meet the minimum velocity which is specified as 0.6m/sec in design standards. The pipe line that have minimal access population or have very low slope did not satisfy the minimum velocity. In estimating the designed sewage flow, the applied daily highest peak loading and hourly highest peaking loading were the load factor for the entire population of the planned area, and for the peak loading of the initial pipes connected to a very small population, we applied the same factor as that applied to the entire area and, as a result, the hourly highest flow was underestimated. Because, in case of the initial pipes, the method of applying the same peak loading to all subject areas is highly possible to produce underestimated design flow, when estimating the designed flow of the initial pipes connected to a small population need to adopt a rational flow factor according to the size of population. For this, it is considered to investigate and analyze raw data on daily and hourly variation of sewage flow.

A Proposal of Unit Hydrograph Using Statistical Analysis in Oedo Stream, Jeju (통계적 기법을 적용한 외도천의 단위유량도 제안)

  • Lee, Jun-Ho;Yang, Sung-Kee;Jung, Woo-Yul
    • Journal of Environmental Science International
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    • v.24 no.4
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    • pp.393-401
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    • 2015
  • Rainfall-runoff model of Jeju Oedo Stream was used to compute the optimal unit hydrograph by HEC-HMS model that reflecting on watershed characteristics. Each rainfall event was comparatively analyzed with the actual flow measurement using Clark, Snyder and SCS synthetic methods for derived unit hydrograph. Subsequently, the null hypothesis was established as p-value for peak flow and peak time of each unit hydrograph by one-way ANOVA(Analysis of variance) was larger than significance level of 0.05. There was no significant difference in peak flow and peak time between different methods of unit hydrograph. As a result of comparing error rate with actual flow measurement data, Clark synthetic unit graph best reflected in Oedo Stream as compared to other methods, and error rate of Clark unit hydrograph was 0.02~1.93% and error rate at peak time was 0~2.74%.

Radionuclide Urodynamic Studies in Patients with Bladder Outlet Obstruction (방사성핵종 요류역학검사를 이용한 하부요로폐색의 평가)

  • Lee, Jae-Tae;Kim, Kwang-Won;Sohn, Sang-Kyun;Chung, Jin-Hong;Lee, Kyu-Bo;Whang, Kee-Suk;Yoon, Yeo-Deuk;Sohn, Houng-Gyu;Chung, Sung-Kwang
    • The Korean Journal of Nuclear Medicine
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    • v.24 no.1
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    • pp.24-28
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    • 1990
  • Various urodynamic studies have been used in patients with bladder outlet obstruction in order to evaluate the degree of obstruction, the results of therapy and postprostatectomy conditions. Radionuclide urodynamic study was performed in 27 patients with bladder outlet obstruction and 30 normal controls. The parameters evaluated were voiding time, 50% voiding time, average flow rate, peak flow rate, corrected peak flow rate, ejection fraction of the bladder and residual urine. Voiding time, 50% voiding time and residual urine of patients were significantly larger than controls and average flow rate, Peak flow rate, peak corrected flow rate and ejection fraction were significantly lower in patients. This method was noninvasive procedure for determining of voiding parameters and it avoids the extraexamination needs to determine the residual urine.

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Identification of unit hydrograph peak behavior according to changes in precipitation scale in a virtual watershed (가상 유역의 강수 규모 변화에 따른 단위유량도 첨두치의 거동 규명)

  • Yoo, Ju-Hwan;Kim, Joo-Cheol
    • Journal of Korea Water Resources Association
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    • v.56 no.10
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    • pp.655-665
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    • 2023
  • In this study, unit hydrographs are calculated when precipitations of 10 scales instantaneously occurs in a virtual watershed with a constant slope and roughness. Then, the relationship between the peak flow rate and the peak occurrence time of the unit hydrograph was calculated for the precipitation scale, respectively. At this time, the virtual watershed simplified with a rhombic shape, a constant slope, and a flow condition with a certain roughness was applied instead of a natural watershed in order to understand the effect the precipitation scale has on the peak value of the unit hydrograph. And it was assumed that the precipitation in the basin was effective rainfall and the runoff was direct runoff, and the runoff flowed in a straight, uniform flow from the drop point to the outlet. The relationship between the peak flow and the peak occurrence time of the unit hydrograph was calculated in the case of 10 types of precipitation scales of 10 mm, 40 mm, 90 mm, 160 mm, 250 mm, 360 mm, 640 mm, 1,000 mm, 1,210 mm, and 1,690 mm of effective precipitation. A noteworthy achievement of this study is that, even without the storage effect of the watershed, as the scale of precipitation increases, the depth of runoff increases, so the flow rate in the watershed increases and the distance per unit time increases, so the peak flow rate increases and the peak occurrence time increases. This is a nonlinear characteristic of watershed runoff.

AI doped ZnO thin film deposited with $O_2$ gas flow rate (산소 가스 유량비에 따라 제작한 Al이 도핑된 ZnO 박막)

  • Cho, Bum-Jin;Keum, Min-Jong;Kim, Kyung-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.67-68
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    • 2006
  • We prepared the AZO thin film with different $O_2$ gas flow rate. the AZO thin films were deposited on glass substrate at room temperature, working gas pressure of 1mTorr. the electrical, structural and optical properties of AZO thin films were investigated by using Hall Effect measurement system, X-ray Diffractometer (XRD) and UV-VIS spectrometer. From the results, we could obtain that AZO thin film with low resistivity of $8.5{\times}10^{-4}{\Omega}cm$ was exhibited in specific $O_2$ gas flow rate. Also, the transmittance of over 80% in visible range was observed in specific $O_2$ gas flow rate. In all of the AZO thin film with the transmittance of over 80%, diffraction peak of (002) direction was observed, while amorphous peak was observed in the AZO thin film with the low transmittance.

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Compensation of Peak Expiratory Air Flow Rate Considering Initial Slope in Velocity Type Air Flow Transducer (속도계측형 호흡기류센서에서 상승시간을 고려한 최고호기유량의 교정 기법)

  • Cha, Eun-Jong;Lee, In-Kwang;Kim, Seong-Sik;Kim, Wan-Suk;Park, Kyung-Soon;Kim, Wun-Jae;Kim, Kyung-Ah
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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    • pp.867-872
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    • 2009
  • Peak expiratory flow rate(PEF) is one of the most important diagnostic parameters in spirometry. PEF occurs in a very short duration during the forced expiratory maneuver, which could lead to measurement error due to non-ideal dynamic characteristic of the transducer. In such case the initial slope of the flow rate signal determines the accuracy of the measured PEF. The present study considered this initial slope as a parameter to compensate PEF. The 26 standard flow rate signals recommended by the American Thoracic Society(ATS) were flown through the air flow transducer followed by simultaneous measurements of PEF and maximum transducer output$(N_{PEF})$. $N_{PEF}$-PEF satisfied a quadratic equation in general, however, two signals (ATS #2 and #26) having large initial slopes deviated from the fitting equation to a significant degree. The relative error was found to be in a linear relationship with the initial slope, thus, $N_{PEF}$ was appropriately compensated to provide accurate PEF with mean relative error less than only 1%. The 99% confidence interval of the mean relative error was less than a half of the error limit of 5% recommended by ATS. Therefore, PEF can be very accurately determined by compensating the transducer output based on the initial slope, which should be a useful technique for air flow transducer calibration.

The Effect of Twenties Female Caffeine Addiction on Cardiorespiratory Capacity (카페인 중독이 20대 성인 여성의 심장호흡기계능력에 미치는 영향)

  • Yoon, Young-Jeoi
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.8
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    • pp.197-202
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    • 2020
  • In this study, we investigate the effect of twenties female caffeine addiction on cardiorespiratory capacity. For this study, we divided 35 female students at H university into caffeine addict group(n=17) and none caffeine addict group(n=18). Measure maximal oxygen uptake, maximal energy consumption and METs using Cycle Ergometer to assess cardiac capacity. Measure peak inspiratory pressure, peak inspiratory flow rate, peak inspiratory capacity, average inspiratory pressure, average inspiratory flow rate, average inspiratory capacity using Power Breathe K5 to assess respiratory capacity. As a result, cardiac capacity showed a statistically significant decrease in maximal oxgen uptake and METs compared caffeine addict group to none caffeine addict group(p<.001). respiratory capacity showed a statistically significant decrease in peak inspiratory pressure(p<.05), peak inspiratory flow rate(p<.01), average inspiratory pressure(p<.01), average inspiratory flow rate(p<.01), compared caffeine addict group to none caffeine addict group. Combining the results of the study, we could see that caffeine addiction reduces the cardiorespiratory capacity in twenties female. Therefore, it could be used as a basis date to prevent caffeine addiction for twenties female.