• Title/Summary/Keyword: Flush-out

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Characteristics of Non-Point Pollution from Road Surface Runoff

  • Lee, Chun-Sik;Jang, Seong-Ho
    • Journal of Environmental Science International
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    • v.19 no.6
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    • pp.665-670
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    • 2010
  • Pollutants from urban pavement consists various kinds of substances which are originated from dry deposition, a grind out tire, corrosive action of rain to pavement and facilities and raw materials of the road etc.. These are major pollutants of urban NPS (Non-point source) during rainfall period. However there is not enough information to control such pollutants for appropriate management of natural water quality. In this study of transportation areas, three monitoring stations were set up at trunk road, urban highway and national road in Gyeongnam province. Runoff flow rate was measured at every 15minutes by automatic flow meters installed at the end of storm sewer pipe within the road catchment area for water quality analysis. Data was collected every 15 minutes for initial two hours of rainfall. Additional samples were collected 1-4 hours interval till the end of rainfall. The monitoring parameters were $COD_{Mn}$, SS, T-N & T-P and heavy metals. The average EMCs of TSS and $COD_{Mn}$ were 62.0 mg/L and 24.2 mg/L on the city trunk road, which were higher than those of urban highway and national road, indicating higher pollutant loads due to activities in the city downtown area beside the vehicle. On the other hand, the average EMC of T-N and T-P were in the range of 2.67-3.23 mg/L and 0.19-3.21 mg/L for all the sampling sites. Heavy metals from the roads were mainly Fe, Zn, Cu and Mn, showing variable EMCs by the type of road. From the TSS wash-off analysis in terms of FF(first flush) index, first flush phenomenon was clearly observed in the trunk road(FF : 0.89-1.43). However, such mass delivery behavior was not apparently shown in urban highway(FF : 0.90-1.11) and national road(FF : 0.81-1.41).

Study on the progressive collapse resistance of CP-FBSP connections in L-CFST frame structure

  • Xiong, Qingqing;Wu, Wenbo;Zhang, Wang;Chen, Zhihua;Liu, Hongbo;Su, Tiancheng
    • Steel and Composite Structures
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    • v.44 no.3
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    • pp.437-450
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    • 2022
  • When the vertical load-bearing members in high-rise structures fail locally, the beam-column joints play an important role in the redistribution of the internal forces. In this paper, a static laboratory test of three full-scale flush flange beam-reinforced connections with side and cover plates (CP-FBSP connection) with double half-span steel beams and single L-shaped columns composed of concrete-filled steel tubes (L-CFST columns) was conducted. The influence of the side plate width and cover plate thickness on the progressive collapse resistance of the substructure was thoroughly analyzed. The failure mode, vertical force-displacement curves, strain variation, reaction force of the pin support and development of internal force in the section with the assumed plastic hinge were discussed. Then, through the verified finite element model, the corresponding analyses of the thickness and length of the side plates, the connecting length between the steel beam flange and cover plate, and the vertical-force eccentricity were carried out. The results show that the failure of all the specimens occurred through the cracking of the beam flange or the cover plate, and the beam chord rotations measured by the test were all greater than 0.085 rad. Increasing the length, thickness and width of the side plates slightly reduced the progressive collapse resistance of the substructures. The vertical-force eccentricity along the beam length reduced the progressive collapse resistance of the substructure. An increase in the connecting length between the beam flange and cover plate can significantly improve the progressive collapse resistance of substructures.

Experimental verification and improvement of heat transfer tube local wall temperature measurement method

  • Jiabao Liu;Xiaxin Cao;Peixun Yang
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4317-4328
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    • 2023
  • To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

Discharge Characteristics of the Indicator Microorganisms of Combined Sewer Overflows (합류식 하수관거 월류수의 지표미생물 배출 특성)

  • Kim, Geonha
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.4
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    • pp.627-635
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    • 2006
  • Combined sewer overflow (CSOs) is a primary diffuse source degrading water quality of urban streams. In this study, CSOs caused by 5 different rainfall events at an urban watershed located in Daejeon city were monitored for the indicator microorganism concentrations. Event mean concentration (EMC) of the indicator microorganisms were: total coliform = $2.46{\times}10^6CFU/100mL$; fecal coliform = $1.01{\times}10^6CFU/100mL$; E.coli = $5.20{\times}10^5CFU/100mL$; and Fecal Streptococci = $6.08{\times}10^5CFU/100mL$. In addition, coliform concentrations were well correlated with suspended solid concentrations and the first flush effects were identified. Settling tests were carried out to estimate removal rate of indicator organisms by sedimentation from CSOs. As microorganisms are discharged in association with suspended solid, ten minutes of settlement can lower 44% of indicator microorganism leading.

Management of Swimming Pool (수영장 관리)

  • Kim Kyong-Ho
    • Journal of environmental and Sanitary engineering
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    • v.4 no.1 s.6
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    • pp.37-42
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    • 1989
  • Management of Swimming pool is focused on Swimming pool samitation in relation with chlorination of swimming water and potable water, disposal of waste and excrement within the boundry of swimming pool that may be summerised as follows: 1. Chlorination of Swimming Water Residual chlorine must be kept within the range of $0.4\~0.6 mg/l$ and in case of chloramine should be $0.7\~1.0mg/l$ while swimming pool is in operation 2. Chlorination of potable Water Residual chlorine must be kept within the rangs of $0.2\~04 mg/l$ at all time 3. Disposal of litters must be kept in the water tight waste bin with fitted lid, and waste should not be overflow -out of the bin. When waste in landfilled, the sufficient amount of cover material should be used daily. 4. Disposal of excrement Toilet must be water-flush type. However, The establishment of pit latrine is unavoidable the excrement must be covered with lime or dirt so that excrement should not be exposed to air.

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Methods of Computing Change Times of Dynamic Workflow Changes

  • Shingo Yamaguchi;Ge, Qi-Wei;Minoru Tanaka
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.645-648
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    • 2000
  • A workflow is a flow of work carried out by multiple people. In order to increase efficiency, it is re-quired to change the current workflow dynamically. Till now, three types of dynamic changes: flush, abort, and synthetic cut-over (SCO) , have been proposed. How- ever, the performance evaluations for dynamic workflow changes have not been undertaken. To do so, measuring the amount of time cost making a single change (called change time) and comparing the methods for obtaining such times become ever important. In this paper, we first define change time and then propose a computation method individually for each change type. Finally, we evaluate the performance of an example net change by computing the change times.

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Phenomenological Study on Experience of Preterm Labor (임부의 조기진통 경험에 대한 현상학적 연구)

  • Ryu, Khyung-Hee;Shin, Hye-Sook
    • Women's Health Nursing
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    • v.15 no.2
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    • pp.140-149
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    • 2009
  • Purpose: The purposes of this phenomenological study were to explore the experience of preterm labor. Methods: The participants were 7 women admitted to two obstetric hospitals in Kyunggi-do Province with preterm labor. Data was collected with MP3 records through individual in-depth interviews and participated observation. The data was analyzed by Giorgi(1985) method. Results: The results were divided into six categories as follows: 1) Inappropriate coping: unexpected event, overwork, lack of insight of preterm labor, 2) Burn out: multiple role, burden, role conflict. 3) Restrictions of lifestyle: uncomfortable hospital environment, wearisomeness, limitations of personal hygiene, 4) Physical discomfort: headache, flush, tremor, palpitations, 5) Psychological distress : concerns about fetus health status, fear of possible preterm delivery, lack of information, financial worries, 6) A transition to new lifestyle: share of household chores, communication with self-help group, careful lifestyle. Conclusion: The findings of this study will offer a better understanding of women's preterm labor experiences and suggest clues to nurses on how to improve the care they provide.

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Making a Transition from the OEM to the OBM in Consumer Goods Industry: Cases of Three Companies in Korea (후발 소비재 기업의 'OEM함정' 탈출과 OBM 이행 과정의 분석: 한국 3개 기업의 사례)

  • Park, Won-Myung;Kim, Sung-Hee;Kim, Yoon-Zi;Lee, Keun
    • Journal of Technology Innovation
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    • v.15 no.2
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    • pp.61-81
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    • 2007
  • A typical small firm in consumer goods sectors of developing countries is an OEM supplier to big MNCs. Lacking design and marketing capability, a small firm relies on the MNCs for survival but their long term growth is not guaranteed as the MNCs are always looking for, and ready to relocate to, cheaper production sites. In this light, we can say that there is something like "OEM trap" from which most firms from LDCs find difficult to move out (Lee 2005). In this situation, one way for long term growth and catch-up is to make a transition to the OBM (own brand manufacturer). But, the transition is not easy or even risky. This paper analyzes the cases of three companies in Korea to find out common features in their successful transition to OBM. They are Aurora World (a flush toy maker), Hankook Chinaware (a chinaware maker), and Hanacobi (a plastic-made food container maker with the Lock-and-Lock brand). These firms can be commonly characterized by 1) arranging access to external knowledge base and steady increase of in-house R&D efforts and capabilities leading to acquisition of formal IPRs and their management, and 2) establishment of global production networks with factories in lower-income countries as well as their own independent global marketing network.

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A Study on the Configuration of Two-Dimensional Waterjet Inlet (이차원 물분사 추진장치 입구면 형상에 관한 연구)

  • J.M. Lew;S.K. Hong;Y.G. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.2
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    • pp.9-21
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    • 1999
  • The waterjet is very widely used today in propulsion system of high speed vessel but manufacturer is limited because of an efficiency and a difficulty of a manufacture on the inlet configuration of the waterjet. The importancy in designing the inlet configuration of the waterjet lies on the minimization of the cavitation which is largely affecting the efficiency. In this paper, the configuration analysis is carried out to find a optimum shape which is minimizing the cavitation using a two dimensional potential-based panel method with an inlet configuration of a flush type. Also, it is developed a direct design method finding an inlet configuration by a given pressure distributions. The numerically obtained optimum shape using this configuration analysis method show a good agreement compared to the Kashiwadani's results. It is carried out a direct design method over a lip and a ramp of an inlet configuration wish pressure distributions obtained a result of the configuration analysis and the results show a good agreement compared to original configuration.

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Interactions between Recipients and Embyos affecting Pregnancy Rates in Bovine Embryo Transfer (수정란 이식에 있어서 수란우와 수정란의 상호작용이 수태율에 미치는 영향)

  • 이정호;박항균;조민희
    • Journal of Embryo Transfer
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    • v.1 no.1
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    • pp.76-80
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    • 1986
  • This study was carried out to investigate the inte actions between recipients and embryos to compare pregnancy rates in bovine embryo transfer, such as synchrony and stage of embryos, synchrony and quality of embryos, synchrony and side of uterine horn, and preservation time and stage of embryos. Fifty-two embryos were transferred by surgically to 42 Holstein heifers, 3 Holstein cows and 7 Korean native heifers from Feb., 1985 to June, 1986. The results were as follows: 1. In the trial of interactions between synchrony and embryo stage, recipients synchronired from- hours to + 12 hours in synchrony and embryos from morulac stage to advanced blastoctyst stages showed reason able pregnancy rate. 2. Excellant (A) and good (B) grade embryos showed good pregnancy rate, 81.8% and 73.3% respectively, but fair (C) grade embryos showed poor, 25% only at the same boundary of recipient synchrony. 3. More recipients had corpus luteum on the right ovary than the left, and also had better pregnancy rate (26/32 vs 13/20,81.3% vs 65%). 4. A good pregnancy rates (over 60%) were obtained with the embryo transferred 17hrs after flush at room temperature or field condition in culture medium.

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