• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.12
• /
• pp.4027-4035
• /
• 1996

Accuracy of gas flow measurements using sonic nozzle and factors which influence on the discharge coefficients of sonic nozzle are investigated with high pressure gas flow standard measurement system. The gas flow measurement system comprises two compressors, storage tank, temperature control loop, sonic nozzle test section, weighing tank, gyroscopic scale and data acquisition system. The experiments are performed at various nozzle throat diameter and inlet pressure. Overall uncertainty of discharge coefficients is estimated to less than .+-.0.2% and most of experimental data fall into this range. Dependence of discharge coefficients on the Reynolds number is good agreement with those suggested in ISO document. The influence of swirl on the discharge coefficients becomes greater as the nozzle throat diameter is enlarged. The discharge coefficient of conical nozzle shows about 4.5% lower discharge coefficients than those of toroidal nozzle, but variation trend with Reynolds number is very similar each other and reproducibility of data is very good.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.1
• /
• pp.90-98
• /
• 2016

Currently government certified test method for an automobile remanufactured products is insufficient. Thus many automotive parts in the remanufacturing market are lacking proper evaluation criteria and production of defective products are causing customer dissatisfaction. In this paper a power steering oil pump, which requires stringent manufacturing standards, is studied by the failure mode and effect analysis approach. The research suggested that the test criteria such as discharge flow characteristic test, tightness test, pulley run-out test, pressure switch operation test, low temperature test and rotation pressure durability test should be performed to evaluate the reliability of remanufactured power steering oil pumps. As a result of tests, the performance of remanufactured power steering oil pump satisfied the evaluation criteria of pressure switch operation test and low temperature test. However, the remanufactured power steering oil pump failed to satisfy the evaluation criteria on discharge performance test, tightness test and pulley run-out test. These performance evaluation tests proved the necessity of standard process for the remanufactured power steering oil pump.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.23 no.4
• /
• pp.46-52
• /
• 1981

The aim at this study has the stochastic hydrological analysis for the annual mean discharge and monthly discharge which were observed at Lobith of River Rhine in the Netherlands from 1901 to 1972. After this study was analysed by computer IBM 370 and Hewlett Parkard 9800, the results were as follows; 1.When 72 data was divided into two groups of subsample data as 36 data, they do not have their properties to be non-homogeneous and inconsistent due to F-test and t-test. 2.The credit limits of the serial correlation coefficient was fluctuated $\pm$0. 231 which was shown in Fig. 3. at significant level 99% by Anderson's test. 3.The correlogram at short term was shown to be no short-term persistence as Fig. 3. 4.Since the correlogram at long term has displayed that Hurst's coefficient was 0.6144 between 0.6 and 0.7, it was to be no long-term persistence. 5.The stochastic model with annual discharge of this River Rhine was shown with $\chi$t=2195+483. 8 $\varepsilon$t as $\chi$t=$\mu$+oet and $\varepsilon$t=$_1$ø$\varepsilon$t-$_1$+ζt where t=1,2,3,..., ζt is an independent series with mean zero and variance (1-ø2), $\varepsilon$t is the dependent series, and 4' is the parameter of the model. 6.The serial correlation coefficient of monthly discharge was explained as $\chi$$_1$ = 0.34 . sin(6-$\pi$t+$\pi$) as Fig.4. and the River Rhine has no large fluctuation and smoothly changed during that time.

• Advances in materials Research
• /
• v.8 no.1
• /
• pp.37-46
• /
• 2019

Electrochemical double layer capacitors (EDLCs) which are fabricated using carbon based electrodes have been emerging at an alarming rate to fulfill the energy demand in the present day world. Activated charcoal has been accepted as a very suitable candidate for electrodes but its cost is higher than natural graphite. Present study is about fabrication of EDLCs using composite electrodes with activated charcoal and Sri Lankan natural graphite as well as a gel polymer electrolyte which is identified as a suitable substitute for liquid electrolytes. Electrochemical Impedance Spectroscopy, Cyclic Voltammetry and Galvanostatic Charge Discharge test were done to evaluate the performance of the fabricated EDLCs. Amount of activated charcoal and natural graphite plays a noticeable role on the capacity. 50 graphite : 40 AC : 10 PVdF showed the optimum single electrode specific capacity value of 15 F/g. Capacity is determined by the cycling rate as well as the potential window within which cycling is being done. Continuous cycling resulted an average single electrode specific capacity variation of 48 F/g - 16 F/g. Capacity fading was higher at the beginning. Later, it dropped noticeably. Initial discharge capacity drop under Galvanostatic Charge Discharge test was slightly fast but reached near stable upon continuous charge discharge process. It can be concluded that initially some agitation is required to reach the maturity. However, the results can be considered as encouraging to initiate studies on EDLCs using Sri Lankan natural graphite.

• Korean Journal of Adult Nursing
• /
• v.13 no.2
• /
• pp.291-304
• /
• 2001

The purpose of this study was to develop Intensive Care Unit (ICU) admission and discharge criteria that would lead to the appropriate utilization of ICU resources and nursing services. For this study, a conceptual framework was developed through a review of the literature. Then in order to identify the overall health condition of patients in the ICU, and to draw up preliminary criteria, the medical records of 58 patients who were admitted to the ICU of Y Medical Center in Seoul between March, 1999 to February, 2000 of were analyzed. Two expert validity tests were done for the preliminary criteria for admission and discharge with 21 patients over 18 years of age who were admitted patients and for 12 patients who were discharged between May 30, 2000 and June 5, 2000 a clinical validity test was also done. After this process, the final admission and discharge criteria were developed. The results of this study are summarized as follows: 1. After a review of the literature, there were 9 categories for admission criteria cardiologic, gastrointestinal, neurologic, endocrine, post-op care of major surgery, vital signs, laboratory values, and a category of miscellaneous items. Discharge criteria had 3 categories which were vital signs, laboratory values, and a category of miscellaneous items. 2. From the medical records of the 58 patients who were admitted to the ICU, 45 items for preliminary criteria for admission and 17 for discharge were identified. 3. The two expert validity tests showed that of the 45 items 29 admission items received over 75 percent agreement. The 16 admission items which received less than 75 percent agreement were revised or deleted from the admission criteria. Of the 17 discharge items, 11 had over 75 percent agreement and 6 less then 75 percent agreement. These were revised or deleted from the discharge criteria. 4. In the clinical validity test, 14 admission items showed more than 75 percent agreement and 11 discharge items more than 83 percent agreement. 5. The final criteria consisted of 29 items for admission and 11 items for discharge. Since patients being considered for admission to the ICU have complex problems, there is a need to make the decision based on more than a single issue. This tool will insure that the ICU nursing care and treatment resources are appropriately used by allowing a multi-professional health team to make admission and discharge decisions.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1969-1971
• /
• 2004

For evaluation of partial discharge performances of electrical power appratus such as Insulator, circuit breaker and transformer and so on, Partial discharge measuring system(ERA) consisted of PD detector including amplifier, coupling capacitor, PD calibrator and voltage divider are used PD measuring system is very important factor which affect the test result and show reliability of test result in test laboratory, In this paper, we describe tracebility and uncertainty of PD measuring system in test laboratory based on IEC 60270.

• Proceedings of the KIEE Conference
• /
• 2005.10a
• /
• pp.169-172
• /
• 2005

The simulation of Hydraulic pressure distribution of discharge tube with globular beads and the removal characteristic of Escherichia coli by the discharge tube with globular beads were estimated. The removal characteristic of Escherichia coli was related to the input voltage because the electric field is increased according to input voltage. As the passing amount of test water in discharge tube is increased, the removal ratio of Escherichia coli was increased because passing numbers of electric field section is increased.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.2
• /
• pp.53-60
• /
• 2008

A test was conducted using two high density discharge lamps, the H2D and the structurally new H4D. They were tested for luminous illumination and luminous temperature in the day and night time. The test was conducted without crippling the performance of the H2D by adding a magnetic actuator, enabling it to move left to right, and up and down. By making these modifications we constructed a sample of the H4D. We compared the H2D and the H4D sample's luminous illumination and luminous temperature by using a photometer and a digital thermometer in the day and night time. We discovered that the H2D and H4D performed similarly from the data we gathered. Now we know the H4D has potential use and extensive research needs to be made to gather more detailed data.

• The KSFM Journal of Fluid Machinery
• /
• v.16 no.5
• /
• pp.11-17
• /
• 2013

This study is aimed to construct a marine small hydro power plant using discharge water of fish farm in Jeju Haengwon-ri. The difference of design methods between marine small hydro power plant and land small hydro power plant is to consider the tides. Moreover, ground condition should be examined because gushout sea water comes out from the ground at high tide in Jeju as the ground of Jeju beach consists of basalt stone. From the field test of the turbine generator after construction of the power plant, output power and efficiency of the turbine generator shows good conformance to the required conditions.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.7
• /
• pp.1375-1379
• /
• 2009

Insulation tests have been performed on two generator stator bars under accelerated aging under a laboratory environment. Electrical stress was applied to stator bar No.1, and electrical and thermal stresses were applied to stator bar No.2. Nondestructive stator insulation tests including the ac current, dissipation factor($tan{\delta}$), and partial discharge tests have been performed on both bars as the bars were aged for 11460 hours. Experimental test results show that ${\Delta}I$, ${\Delta}tan{\delta}$, and partial discharge of No. 1 and No.2 stator bars increased with increased in aging time. It has been concluded from the test that the stator insulation of the two generators are in good condition.