• Title/Summary/Keyword: Depth of Discharge

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Sensitivity Analysis of Debris Flow Simulation in Flo-2D Using Flow Discharge and Topographic Information (유량과 지형조건에 따른 Flo-2D에서의 토석류 확산 민감도 분석)

  • Kim, Namgyun;Jun, Byonghee
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.547-558
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    • 2022
  • In August 2020, a debris flow occurred in Gokseon, Jeollanam-do, that resulted in the death of five residents. In this study area, high-resolution 0.03 m topographic information was generated through photogrammetry, and the amount of soil movement/loss was measured. In addition, sensitivity analysis was performed for flow depth, flow velocity, and debris flow area with the program Flo-2D using the difference in simulation parameter that discharge and topographic information. Wth increasing debris flow input discharge, increases were seen in flow depth, flow velocity, and debris flow area, as ell as in the gap in results from high-resolution topographic information and low-resolution topographic information. Also, when high-resolution topographic information was used, the results were similar to the actual (measured) flow direction of the debris flow. Therefore, the application of high-resolution topographic information increases the accuracy of the debris flow analysis results compared with low-resolution information. Results could be further imporved in the future by considering geological information such as yield stress and viscosity.

A Study on Water Environment and Benthic Macroinvertebrate Community in Reclaimed Wastewater Effluent Dominated Stream (하수처리수 방류 하천의 물환경과 저서성 대형무척추동물 군집 생태 연구)

  • Son, Jung-Won;Kwag, Jin-Suk;Cho, Gab-Je;Ryou, Dong-Choon
    • Journal of Korean Society on Water Environment
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    • v.37 no.3
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    • pp.190-203
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    • 2021
  • Water quality, benthic macroinvertebrate communities, and other factors were investigated to explore the effects of the effluent discharge from a sewage treatment plant into Jwagwang stream in Busan in 2019. During the study period, the flow rate of this stream was in the range of 10,400 m3/day to 52,200 m3/day except for the discharge of about 24,000 m3/day of the effluent. After discharge, the flow velocity increased by about 65% and the water depth increased by about 40%. At sites downstream of the discharge point, BOD, COD, TOC, T-N, T-P, and other water quality values were worse than those of the upstream sites. The periphytic algal chlorophyll-a concentrations in the natural substrata were higher than those of the upstream sites, especially in May and August. However, at sites downstream of the discharge point, the individual numbers of Annelida were decreased and individual numbers of the insecta of arthropoda were increased. Also, species numbers and the diversity and dominance indexes were improved in the sites downstream of the discharge point. The functional feeding groups (FFGs) of collector-filterers were increased and the habitat orientation groups (HOGs) of sprawlers, burrowers, and clingers were especially increased at the sites with additional reclaimed wastewater effluent flow. Regardless of the effluent discharge, BMI, an indicator of ecological stream health using benthic macroinvertebrate species, did not show large gaps between the study points. Although the water quality of the sites downstream of the discharge point was much worse than those upstream, their ecosystem soundness was better than those of the upstream sites from an ecological perspective.

Effect of the Freshwater Discharge on Water Quality Variation and in Haechang Bay, Korea (해창만의 수질환경변동 및 담수방류의 영향평가)

  • Lee, Dae-In;Cho, Hyeon-Seo;Lee, Moon-Ok
    • Journal of Environmental Impact Assessment
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    • v.12 no.5
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    • pp.341-348
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    • 2003
  • Seasonal characteristics of water quality and effect of the freshwater discharge during open the tide embankment in Haechang Bay were evaluated. In the freshwater, where interior of the tide embankment, COD and Chl-a exceeded about 4mg/L and $10mg/m^3$, respectively, independent of season, while in the seawater they showed high values in April and July in contrast to the other period due to input of freshwater and increase of phytoplankton, respectively. The content of seawater inorganic nitrogen maintained a relatively high level at inner part of the bay, whereas high values of inorganic phosphorus content was distributed at all over the bay. The limiting factor for algal growth was nitrogen with respect to the N/P ratio. The compass of influence by the freshwater discharge in April was quite different with water pollutants. As a result of the salinity variation with time, the freshwater extended strongly to offshore from the surface layer without mixing with depth when open the tide embankment, and reached within about one hour at a station which is 3.5km from the tide embankment. To effective water quality management of Haechang Bay, discharge rate and pollutant loads should be controlled.

Needs for Post-hospital Education among Parents of Infants and Toddlers with Congenital Heart Disease

  • Lee, Bo Ryeong;Koo, Hyun Young
    • Child Health Nursing Research
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    • v.26 no.1
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    • pp.107-120
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    • 2020
  • Purpose: This study was conducted to investigate the educational needs of parents of infants and toddlers with congenital heart disease (CHD) after hospital discharge. Methods: Qualitative content analysis was conducted of in-depth interviews of eight parents, and the results of an online survey of 171 parents were analyzed quantitatively. Results: Only 16.4% of parents reported that they had received education after hospital discharge on how to provide care for a child with CHD at home. The main reason why parents did not receive education on this topic was that they did not have sufficient opportunities or information (75.5%). In addition, 97.1% of parents stated that they needed educational programs that would be available at home after discharge. In terms of specific educational content, parents expressed the highest needs for education on the symptoms of CHD and ways to cope with them, the prognosis of CHD, and the growth and development of infants and toddlers with CHD. Conclusion: The study showed that parents' educational needs were high in many ways. However, the information and educational opportunities offered after discharge were insufficient compared to those needs. Further research is needed to develop post-hospital educational programs that meet their needs.

Discharge Coefficient of Side Weir for Various Curvatures Simulated by FLOW-3D (FLOW-3D를 이용한 다양한 곡률에 대한 횡월류 위어의 유량계수 산정)

  • Jeong, Chang Sam
    • Journal of Korean Society of Disaster and Security
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    • v.8 no.1
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    • pp.5-13
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    • 2015
  • In this study, the lateral overflow discharge coefficients for the curvatures of side weir on meandering channel were analyzed. The side weir installed in accordance with the variation of the radius of curvature of the central angle bends with $180^{\circ}$. FLOW-3D model is applied to calculate the discharge coefficients of the side-weir on meandering and straight channels and the characteristics of the discharge coefficients are analysed. In order to verify the numerical model, the results from the hydraulic experiment conducted by the former research are compared with the results simulated by FLOW-3D in the same conditions. The discharge coefficients are calculated for the ratio between curvature ($R_c$) and channel width (b), and the ratio between over flow discharge of the straight channel ($Q_{wc}$) and the meandering channel ($Q_{wc}$) are compared. As the result, the discharge coefficients depend on the weir depth on upstream, and the radius of curvature, so that the discharge coefficients of side weir on the meandering channel can be estimated by them on the straight channel.

Discharge Nursing Needs of Patients having Surgery with Gastric Cancer (위암 수술 환자의 퇴원 간호요구)

  • Lee, Jong-Kyung;Lee, Mi-Soon
    • Korean Journal of Adult Nursing
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    • v.15 no.1
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    • pp.22-32
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    • 2003
  • Purpose: The purpose of this descriptive study was to identify the discharge nursing needs of patients who received gastrectomy. Method: The subjects of this study consisted of 100 patients who had gastric surgery in 4 university hospitals in chungnam province. The instrument for this study was developed by the researcher based on literature through in-depth interviews. Data was collected from October 4 to October 30, 2000. Result: The results were as follows: Discharge nursing needs were classified in 8 main categories. The 8 categories were 'emotional and spiritual support', 'nutrition and diet control', 'medication', 'treatment planning and follow up care', 'activity level', 'symptom management' 'health seeking behavior' and 'social support'. The total mean score for nursing needs was 3.89. 'Nutrition and diet control' was the highest degree of nursing needs and 'activity level' was the lowest degree of nursing needs. There were significant differences in degrees of nursing needs between different ages(F=2.74, p=.048), level of education(F=2.91, p=.038) and period since diagnosis(F=4.46, p=.037). Conclusion: This study looked at 8 categories of discharge nursing needs. Patients identified 'nutrition and diet control' as the highest need and 'activity level' as the lowest need. Further research needs to be done to identify discharge educational needs for various age groups, educational level and for patients with varing lengths of diagnosis time to surgery.

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Effects of Nitrogen Gas Ratio on Nitride Layer and Microhardness of Tool Steel(SKH51) in Plasma Nitriding (플라즈마질화시 방전가스중 질소가스의 비율이 공구강(SKH51)의 질화층 및 미소경도에 미치는 영향)

  • Kim, Deok-Jae;Lee, Hae-Ryong;Gwak, Jong-Gu;Jeong, U-Chang;Jo, Yeong-Rae
    • Korean Journal of Materials Research
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    • v.12 no.6
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    • pp.447-451
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    • 2002
  • Pulsed DC-plasma nitriding has been applied to form nitride layer having only a diffusion layer. The discharge current with the variation of discharge gases is proportional to the intensity of $N_2^+$ peak in optical emission spectroscopy during the plasma nitriding. The discharge current, microhardness in surface of substrate and depth of nitride layer increased with the ratio of $N_2\;to\;H_2$ gas in discharge gases. When the ratio of $N_2\;to\;H_2$ is lower than 60% in the discharge gases, high microhardness value of 1100Hv nitride layer which contains no compound layer has been formed.

Monitoring of Outlet Discharge and Water Quality from a Small Agricultural Reservoir (소규모 농업용 저수지의 통관 방류량 및 수질 측정)

  • Choi, Jin-Kyu;Son, Jae-Gwon;Koo, Ja-Woong;Yoon, Kwang-Sik;Kim, Young-Ju
    • Journal of Korean Society of Rural Planning
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    • v.6 no.2 s.12
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    • pp.73-81
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    • 2000
  • This study was carried out to measure the amount of outlet discharge and analyse the water quality from an agricultural reservoir. Joongpyong reservoir was selected as the monitoring site. Daily discharge was determined by measured water level data of delivery canal and the stage-discharge relation curve. The measured water discharge through culvert outlet of Joongpyong reservoir was 593,200m3 which was equivalent to irrigation depth 1,186mm during irrigation period in 1999. And water samples were taken from the surface water of reservoir and delivery canal, periodically. Temporal variation of water quality constituents such as water temperature, pH, EC, total nitrogen, total phosphorus were investigated. The result showed that pH was ranged 6.9 7.8, total nitrogen 1.39 4.11mg/L, total phosphorus 0.007 0.036 mg/L, respectively.

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The Change in Diffusion Coefficient and Wear Characteristic in Carbonitriding Layer of SCM415 Steel (침탄질화 처리된 SCM415강의 깊이에 따른 확산 및 마모특성 변화)

  • Lee, Su-Yeon;Youn, Kuk-Tea;Huh, Seok-Hwan;Lee, Chan-Gyu
    • Journal of Surface Science and Engineering
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    • v.44 no.5
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    • pp.207-212
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    • 2011
  • In this study, the change in diffusion coefficient and wear characteristic with depth in the carbonitriding layer of SCM415 steel was discussed. To determine the diffusion coefficient, depth profile of carbon was measured from the surface using the Glow Discharge Spectrometer. In otherwise, measurements of carbide fraction, micro vickers hardness of surface and observation of microstructure have been implemented through the SEM image. $Fe_3$(C,N) layer and effective depth were increased as the time for carbonitriding takes longer. According to wear experiment, the results showed that wear resistance was improved by $Fe_3$(C,N) layer and effective depth.

Development of Inspection Technology for the Depth Sizing on Surface Flaw of Pump Diffuser Vane (펌프 Diffuser Vane 표면결함 깊이측정 기법 개발)

  • Park, Cher-Young;Kim, Jin-Hoi
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.4 no.2
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    • pp.46-49
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    • 2008
  • NDE(Nondestructive examination) detects a flaw or discontinuity in materials. Flaws detected by the pre-service or in-service examinations shall be sized for the purpose of analysis and repair. A flaw that is initiated from the surface is difficult to determine its depth by NDE. The depth of the surface flaw can be measured using an ultrasonic diffracted wave. To find the optimum standard for ultrasonic parameter(For example, frequency & size of transducer), a mock-up test and simulation were established and studied. This inspection technology may show the depth sizing possibility of the flaw down to nearly two(2) mm.

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