• Title/Summary/Keyword: Observed discharge

Search Result 1,239, Processing Time 0.023 seconds

Estimation of Design Flood Discharge by Areal Ratio for Ungauged Basin (면적비를 적용한 미계측유역에서의 설계홍수량 산정방안)

  • Lee, Jiho;Park, Jaebeom;Song, Yangho;Jun, Hwandon;Lee, Jungho
    • Journal of Wetlands Research
    • /
    • v.19 no.3
    • /
    • pp.335-344
    • /
    • 2017
  • In this study, We proposed a method to estimate the design flood by area ratio in an ungauged basin. For that, the discharge parameters was determined by calibration of observed data at the watershed outlet and then peak flow was estimated by area ratio. In order to verify suggested method, peak flow was compared the observed discharge of the small river basin and the design flood discharge of river implementation projects. The results were summarized as follows. As a result of comparing the discharge by the area ratio and observed discharge, the difference of peak flows were analysed 14 ~ 25%. When the discharge calculated with area ratio of small river was compared with the design flood discharge of river implementation projects, the relative error was analyzed to be less than 20%. It means that suggested method in this study is appropriate.

Influence of intermixed gas on stable townsend discharge (안정 Townsend 방전에 대한 혼입가스의 영향)

  • 하성철
    • 전기의세계
    • /
    • v.30 no.5
    • /
    • pp.306-312
    • /
    • 1981
  • The Townsend discharge domain is generally observed with stable positive characteristics in N$_{2}$ gas discharge at low pressures differently in the others, which transfer immediately to glow dischage after self-sustaining discharge starts. In this paper, the presence of the stable Townsend discharge, applied voltage-discharge current characteristics and the effect of disgased electrode surface on stable townsend discharge are studied experimentaly in N$_{2}$ gas mixed with 0.05% of No in volume. As the result of this experiment, the stable Townssend discharge is observed only in pure nitrogen with the valve of pd.geq.8[torr.cm] (p=gas pressure, d=gap spacing), but not in gas mixtures. This is considered that No gas in gas mixtures disexcites effectively the metestble state of nitrogen.

  • PDF

Spectroscopic Identification of Isomeric 2,3- and 2,6-Dimethylbenzyl Radicals in Corona Discharge

  • Yoon, Young Wook;Lee, Sang Kuk
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.3
    • /
    • pp.763-767
    • /
    • 2013
  • We resolved the controversial assignments of the visible vibronic bands observed from corona discharge of 1,2,3-trimethylbenzene. The vibronic bands belonging to the jet-cooled 2,6-dimethylbenzyl radical were clearly identified from the spectrum observed from corona discharge of 2,6-dimethylbenzyl chloride. After subtracting the bands of the 2,6-isomer from the spectrum observed from corona discharge of 1,2,3-trimethylbenzene, the vibronic bands of the 2,3-isomer were also identified. By comparing data with the known vibrational data of 1,2,3-trimethylbenzene and the results of ab initio calculations, we determined the electronic energies of the $D_1{\rightarrow}D_0$ transitions and vibrational mode frequencies in the ground electronic states of the 2,3-and 2,6-dimethylbenzyl radicals.

Fabrication of Atmospheric Coplanar Dielectric Barrier Discharge and Analysis of its Driving Characteristics (평면형 대기압 유전장벽방전장치의 제작 및 동작특성분석)

  • Lee, Ki-Yung;Kim, Dong-Hyun;Lee, Ho-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.1
    • /
    • pp.80-84
    • /
    • 2014
  • The discharge characteristics of Surface Dielectric Barrier Discharge (SDBD) reactor are investigated to find optimal driving condition with adjusting various parameter. When the high voltage with sine wave form is applied to SDBD source, successive pulsed current waveforms are observed owing to multiple ignitions through the long discharge channel and wall charge accumulation on the dielectric surface. The discharge voltage, total charge between dielectrics, mean energy and power are calculated from measured current and voltage according to electrode gap and dielectric thickness. Discharge mode transition from filamentary to diffusive glow is observed for narrow gap and high applied voltage case. However, when the diffusive discharge is occurred with high applied voltage, the actual firing voltage is always lower than that with low driving voltage. The $Si_3N_4$, $MgF_2$, $Al_2O_3$ and $TiO_2$ are considered for dielectric protection and high secondary electron emission coefficient. SDBD with $MgF_2$ shows the lowest breakdown voltage. $MgF_2$ thin film is proposed as a protection layer for low voltage atmospheric dielectric barrier discharge devices.

Pulse-Sequence Analysis of Discharges in Air, Liquid and Solid Insulating Materials

  • Suwayno, Suwayno;Mizutani, Teruyoshi
    • Journal of Electrical Engineering and Technology
    • /
    • v.1 no.4
    • /
    • pp.528-533
    • /
    • 2006
  • Electrical discharges may occur in gas, liquid as well as solid insulating materials. This paper describes the investigation results on the discharges in air, silicone oil and low density polyethylene (LDPE) using needle plane electrode system under AC voltage of 50 Hz. The experimental results showed that for discharge in air (corona), discharge pulses were concentrated around the peak of applied voltage at negative half cycle. For silicone oil positive as well as negative discharges were observed which concentrated around the peak of applied voltage. The positive pulse number was smaller but the magnitude was higher than that of negative discharge. Discharges in void took place at wider range of phase of applied voltage. The unbalance in pulse number and magnitude similar to that of oil discharges were observed. For electrical treeing in LDPE, the discharges were spread before the zero cross of the applied voltage up to the peak at both positive and negative half cycles. The discharge pulse sequence analysis indicated that the PD occurrence in air, oil and void were strongly affected by the magnitude of applied voltage. However, for electrical treeing it was observed that the discharge occurrence was strongly affected by the time derivative of the applied voltage (dv/dt).

A Stochastic Nonlinear Analysis of Daily Runoff Discharge Using Artificial Intelligence Technique (인공지능기법을 이용한 일유출량의 추계학적 비선형해석)

  • 안승섭;김성원
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.39 no.6
    • /
    • pp.54-66
    • /
    • 1997
  • The objectives of this study is to introduce and apply neural network theory to real hydrologic systems for stochastic nonlinear predicting of daily runoff discharge in the river catchment. Back propagation algorithm of neural network model is applied for the estimation of daily stochastic runoff discharge using historical daily rainfall and observed runoff discharge. For the fitness and efficiency analysis of models, the statistical analysis is carried out between observed discharge and predicted discharge in the chosen runoff periods. As the result of statistical analysis, method 3 which has much processing elements of input layer is more prominent model than other models(method 1, method 2) in this study.Therefore, on the basis of this study, further research activities are needed for the development of neural network algorithm for the flood prediction including real-time forecasting and for the optimal operation system of dams and so forth.

  • PDF

Clustering Analysis with Spring Discharge Data and Evaluation of Groundwater System in Jeju Island (용천수 유출량 클러스터링 해석을 이용한 제주도 지하수 순환 해석)

  • Kim Tae-Hui;Mun Deok-Cheol;Park Won-Bae;Park Gi-Hwa;Go Gi-Won
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2005.04a
    • /
    • pp.296-299
    • /
    • 2005
  • Time series of spring discharge data in Jeju island can provide abundant information on the spatial groundwater system. In this study, the classification based on time series of spring discharge was performed with clustering analysis: discharge rate and EC. Peak discharges are mainly observed in august or september. However, double peaks and late peaks of discharge are also observed at a plenty of springs. Based on results of clustering analysis, it can be deduced that GH model is not appropriate for the conceptual model of Groundwater system in Jeju island. EC distributions in dry season are also support the conclusion.

  • PDF

Surface flashover discharge and partial discharge of polymer film in liquid helium (액체 He중 고분자 film의 연면 및 부분방전 연구)

  • 김상현;김현희;정순용;최효상
    • Electrical & Electronic Materials
    • /
    • v.9 no.9
    • /
    • pp.942-948
    • /
    • 1996
  • Electrical properties such as surface flashover discharge and discharge degradations of insulating materials for superconducting cable have been investigated. It is found that the surface voltage is proportional to $l^{0.7}$ (l: discharge length) in liquid helium (LHe). V-t characteristic in LHe was a n=5.5 that was less than liquid nitrogen (L $N_{2}$). After applied AC voltage, the surface condition of polymer films was observed non-eroded areas and eroded areas. The eroded area is depending on the applied voltage. In case of LHe, the crack was observed.d.

  • PDF

A study on the arc discharge characteristics of liquid insulating materials for electrical discharge machine (방전가공기용 액체 절연재료의 아크 방전 특성 연구)

  • 김상현;김해종;마대영;신태민
    • Electrical & Electronic Materials
    • /
    • v.8 no.5
    • /
    • pp.564-571
    • /
    • 1995
  • This paper deals with the arc discharge characteristics of kerosene oil as a basic study on electrical discharge machine. Using needle electrode the discharge voltage, discharge current, discharge energy and the shape of discharge crater are measured. In consequence, it becomes clear that the discharge crater(depth, height, diameter) is depending on the discharge energy. Rapid increase in depth, height and diameter of discharge crater was observed during initial discharge, where discharge energy is large. However, rather slow decrease of those values was found when discharge energy is low or N is more than 3. As the ratio of $I_p$$T_on$ increase, the shape of discharge crater gets near circle. The protuberances of the discharge crater were not formed by the melted needle electrode but by the that of work piece.

  • PDF

Discharge Characteristics of Counter Electrode Discharge Cells of PDP

  • Kim, Young-Jin;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.477-479
    • /
    • 2006
  • In this study, a stripe type counter electrode discharge cell for PDP was attempted to realize high luminance efficiency and low firing voltage for fine pitch discharge cells. The cells were prepared using electroplated Cu/Ni electrodes coated with glass dielectric layer. The discharge behaviors of such cells were observed. These results indicate that the counter electrode discharge cells have different discharge behavior compared with coplanar cells, which may affect the luminance efficiency of the panel.

  • PDF