• Title/Summary/Keyword: Over discharge

Search Result 937, Processing Time 0.031 seconds

A Numerical Simulations on the Flow over Ogee Spillway with Tainter Gate (테인터수문이 설치된 월류형 여수로에서의 흐름에 대한 수치모의)

  • Kim, Dae-Geun;Park, Jae-Hyun;Lee, Jae-Hyung
    • Journal of Korea Water Resources Association
    • /
    • v.37 no.8
    • /
    • pp.675-685
    • /
    • 2004
  • In this study, overflow behaviors through a partially open tainter gate mounted on a standard ogee spillway were investigated by using the FLOW-3D. The results indicated that the discharge coefficient is in the range of 0.685 to 0.723. A relation of gate-controlled discharge to free discharge was proposed and a reasonable correlation between the free and controlled discharge was obtained. Pressures on the spillway crest and the gate were also investigated. As the gate opening rate decreases with a fixed gate opening height and the gate opening height increases at a fixed gate opening rate, negative pressures on the spillway crest and the dimensionless maximum pressures on the gate increase.

Thermal Characteristics of Foams and Discharge of Fire-Protection Foam Spray Nozzle (폼 분무 노즐 방사 분포 및 폼의 열적 특성 연구)

  • Kim, Hong-Sik;Kim, Youn-Jea
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.29 no.1 s.232
    • /
    • pp.151-158
    • /
    • 2005
  • A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

Changes in parents' health concerns by post-preterm birth period in South Korea: a cross-sectional study

  • Yu Jin Jung;Hun Ha Cho
    • Child Health Nursing Research
    • /
    • v.30 no.2
    • /
    • pp.118-128
    • /
    • 2024
  • Purpose: This study aimed to examine the health concerns of parents regarding their premature infants and to identify changes in these concerns during perinatal period and after discharge. Methods: This was a retrospective study performed at a single tertiary center that enrolled 119 premature infants who were discharged from the neonatal intensive care unit (NICU) and visited the outpatient pediatrics department between December 2018 and October 2021. Data on the concerns of 176 parents regarding enrolled premature infants' health from before birth to 1 week after NICU discharge were obtained from outpatient records. The t test and with the chi-squared test were used to analyze the data for this study. Results: The consistently greatest focus of parents' health concerns was the respiratory system. The second focus of parents' health concerns before discharge was the central nervous system. However, during the first week after NICU discharge, the gastrointestinal system was the second-most frequent focus of parents' health concerns among parents of infants without diseases related to prematurity and infants with older gestational ages. Conclusion: The results of this study offer insights into the health concerns among parents of premature infants. Parental health concerns about premature infants vary over time, from before birth to post-discharge, necessitating supportive interventions to enhance parental understanding of their child's health status.

A Study on Development of Estimation for Discharge Rate Reflecting Water Surface Slope (수면경사를 반영한 하천 유량산정에 관한 연구)

  • Choo, Tai Ho;Hong, Soon Heon;Park, Sang Jin;Kim, Young Hwan
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.2
    • /
    • pp.535-542
    • /
    • 2017
  • There is a big difference of discharge rate between drought and flood period in Korea since the importance of water resources management has come to the fore. To know a river characteristics, it needs to estimate river discharge accurately. River discharge is calculated using the measured velocity of cross section and the estimated area of watercourse as input parameters into continuity equation. Generally, flow rate over a river is estimated from the relation equation between level and discharge, in this case, there are weakness for only the equal depths and the equal discharge estimated. In the present study, therefore, water surface slope was estimated using measured water level of Seongseo water level observation station and measured water level using ADVM at Gangchang Bridge. And then, we developed the discharge calculation equation using water surface slope. A method to easily calculated flow rate from the measured depth of the two points that are suggested by reflecting water surface slope because natural stream is unsteady flow, not uniform flow or not steady flow.

Design and Development of Micro Combustor (II) - Design and Test of Micro Electric Spark discharge Device for Power MEMS - (미세 연소기 개발 (II) - 미세동력 장치용 미세 전극의 제작과 성능평가 -)

  • Gwon, Se-Jin;Lee, Dae-Hun;Park, Dae-Eun;Yun, Jun-Bo;Han, Cheol-Hui
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.4
    • /
    • pp.524-530
    • /
    • 2002
  • Micro electric spark discharge device was fabricated on a FOTURAN glass wafer using MEMS processing technique and its performance of electron discharge and subsequent formation of ignition kernel were tested. Micro electric spark device is an essential subsystem of a power MEMS that has been under development in this laboratories. In a combustion chamber of sub millimeter scale depth, spark electrodes are formed by electroplating Ni on a base plate of FOTURAN glass wafer. Optimization of spark voltage and spark gap is crucial for stable ignition and endurance of the electrodes. Namely, wider spark gaps insures stable ignition but requires higher ignition voltage to overcome the spark barrier. Also, electron discharge across larger voltage tends to erode the electrodes limiting the endurance of the overall system. In the present study, the discharge characteristics of the proptotype ignition device was measured in terms of electric quantities such as voltage and currant with spark gap and end shape as parameters. Discharge voltage shows a little decrease in width of less than 50㎛ and increases with electrode gap size. Reliability test shows no severe damage over 10$\^$6/ times of discharge test resulting in satisfactory performance for application to proposed power MEMS devices.

Ecological Characteristics of Marine Algal Communities at the Discharge Canals of Three Nuclear Power Plants on the East Coast of Korea (동해안 3개 원전 배수로 해조군집의 생태적 특성)

  • Kim, Young-Hwan;Ahn, Jung-Kwan
    • ALGAE
    • /
    • v.20 no.3
    • /
    • pp.217-224
    • /
    • 2005
  • The species composition and biomass of marine algae at the discharge canals of three (Gori, Wolseong and Uljin) nuclear power plants on the east coast of Korea were investigated seasonally from February 1992 to October 2000. As a result, 103-107 species of marine algae were found at the discharge canals during the past nine years. In general, algal communities established at the discharge canals were less diverse than those at the intake canals and control sites. 43 species (6 blue-green, 9 green, 10 brown and 18 red algae) of marine algae occurred more than 1/6 frequency and thus can be categorized as warm tolerant species. Among these, two green (Urospora penicilliformis, Cladophora albida), four brown (Sphacelaria divaricata, S. rigidula, Sargassum coreanum, S. fulvellum) and four red algae (Stylonema alsidii, Bangia atropurpurea, Hypnea charoides, Chondria crassicaulis) are recorded as warm tolerant marine algae for the first time in Korea during this study. Enteromorpha compressa, Padina arborescens, Amphiroa zonata and Ahnfeltiopsis flabelliformis were common species found more than 50% frequency at the discharge canals of all three nuclear power plants investigated. Dominant species in biomass were Padina arborescens and Amphiroa zonata. Results showed that, as a whole, the red algae appeared as predominant algal group at the discharge canals of all three nuclear power plants on the east coast of Korea. However, the biomass proportion of dominant algae at the discharge canals of each nuclear power plant varied over the year during the past nine years.

Smoking Relapse and Related Factors Within One Year Among Successes of the Smoking Cessation Clinics of Public Health Centers (보건소 금연클리닉 금연성공자의 1년내 재흡연과 관련요인)

  • Kim, Mi-Jag;Jeong, Ihn-Sook
    • Journal of Preventive Medicine and Public Health
    • /
    • v.44 no.2
    • /
    • pp.84-92
    • /
    • 2011
  • Objectives: This study aimed to investigate smoking relapse and the related factors within 1 year after discharge from the smoking cessation clinics (SCCs) of public health centers (PHCs). Methods: Data were collected with a structured questionnaire from 395 people who success fully stopped smoking at 4 SCCs in Busan between May and June 2009, and this data were analyzed by Kaplan-Meier survival curves and the Cox proportional hazard model. Results: The rate of smoking relapse within 1 year after discharge from SCCs was 39.2% and this decreased rapidly over 6 months after discharge. The factors related to smoking relapse within 1 year after discharge from SCCs were being female (HR, 2.11; 95% CI, 1.17 to 3.82), a trial of smoking cessation with any assistants (HR, 1.95; 95% CI, 1.19 to 3.19), more than 7 ppm of exhaled CO2 on the SCCs' registration (HR, 1.81; 95% CI, 1.24 to 2.64), use of pharmacotherapy after discharge from SCCs (HR, 2.00; 95% CI, 1.36 to 2.93), alcohol drinking more than once a week after discharge from SCCs (HR, 3.32; 95% CI, 2.15 to 6.78), and a perceived barrier (HR, 1.21; 95% CI, 1.14 to 1.30) after discharge from the SCCs. Conclusions: According to the results, at least 6 months follow-up after discharge from SCCs of public health centers is recommended to reduce the rate smoking relapse. It is also recommended to strengthen the education on how to overcome barriers such as drinking in the course of smoking cessation clinics.

Unbalance load current of Operating in Parallel of Lead acid batteries connection condition (납 축전지 병렬운전시 발생하는 전류 불평형 현상분석 및 대책)

  • 반한식;곽철훈;최규하;목형수
    • Proceedings of the KIPE Conference
    • /
    • 1999.07a
    • /
    • pp.210-213
    • /
    • 1999
  • A battery is the device that transforms the chemical energy into the direct-current electrical energy directly without a mechanical process. Unit cells are connected in series to obtain the necessary voltage, while being connected in parallel to organize capacity for load current and to decrease the internal resistance for corresponding the sudden shift of the load current. The circular-current, however, could be occurred when the system is driven in parallel. As a result, the new batteries are heated by over-change and discharge, and the over charge current makes to increase the rust of the positive grid and consequently the shortened life of the new batteris would be shown. In this paper, the internal resistance of charge and discharge will be balanced, through inserting the resistance into the system by way of calculation of the changed amount of internal resistance.

  • PDF

Reconstruction Characteristics of MgO (111) Textured Protective Layer by Over-Frequency Accelerated Discharge in AC Plasma Display Pannel

  • Kwon, Sang-Koo;Kim, Jeong-Ho;Moon, Seung-Kyu;Kim, Hyun-Ha;Park, Kyu-Ho;Kim, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08a
    • /
    • pp.224-227
    • /
    • 2007
  • The reconstruction characteristics of MgO (111) textured protective layer by over-frequency accelerated discharge in AC-PDP were investigated and correlated to the variations of electronic structures. The reconstruction process and exaggerated grain growth (EGG) were explained by defect-assisted 2-D nucleation and growth mechanism combined with charged cluster model.

  • PDF

A Multilevel Analysis about the Impact of Patient's Willingness for Discharge on Successful Discharge from Long-term Care Hospitals (퇴원 의지가 요양병원의 성공적 퇴원에 미치는 영향에 대한 다수준 분석)

  • Ghang, Haryeom;Lee, Yeonju
    • Health Policy and Management
    • /
    • v.32 no.4
    • /
    • pp.347-355
    • /
    • 2022
  • Background: Since November 2019, long-term care hospitals have been able to provide patients with discharging programs to support the elderly in the community. This study aimed to identify both patient- and hospital-level factors that affect successful community discharge from long-term care hospitals. Methods: A multilevel logistic regression model was performed using hospitals as a clustering unit. The dependent variable was whether a patient stayed in the community for at least 30 days after discharge from a long-term care hospital. As for the patient-level independent variables, an agreement between a patient and the family about discharge, length of hospital stay, patient category, and residence at discharge were included. The number of beds and the ratio of long-stay patients were selected for the hospital-level factors. The sample size was 1,428 patients enrolled in the discharging program from November 2019 to December 2020. Results: The number of patients who were discharged to the community and stayed at least for 30 days was 532 (37.3%). The intraclass correlation coefficient was 22.9%, indicating that hospital-level factors had a significant impact on successful community discharge. The odds ratio (OR) of successful community discharge increased by 1.842 times when the patients and their families agreed on discharge. The ORs also increased by 3.020 or 2.681 times, respectively when the patients planned to discharge to their own house or their child's house compared to those who didn't have a plan for residence at discharge. The ORs increased by 1.922 or 2.250 times when the hospitals were owned by corporate or private property compared to publicly owned hospitals. The ORs decreased by 0.602 or 0.520 times when the hospital was sized over 400 beds or located in small and medium-sized cities compared to less than 200 bedded hospitals or located in metropolitan cities. Conclusion: The results of the study showed that the patients' and their family's willingness for discharge had a great impact on successful community discharge and the hospital-level factors played a significant role in it. Therefore, it is important to acknowledge and support long-term care hospitals to involve active in the patient discharge planning process.