• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.33-42
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• 1996

This research is to show the application of runoff model and runoff analysis of urban storm drainage network. the runoff models that were used for this research were RRL, ILLUDAS, and SWMM applicative object basin were Geucknak-chun and Sangmu drainage basin located in Seo-Gu, Kwangju. The runoff analysis employed the design storm that distributed the rainfall intensity according to the return period after the huff's method. The result from the comparative analysis of the three runoff models was as follows The difference of peak runoff by return period was 20-30% at Sangmu drainage area of $3.17 Km^2$, while less than 10% at Geucknak-chun drainage area of $12.7 Km^2$. The peak runoff were similar to all models. At the runoff hydrograph the times between rising and descending points were in the sequence of RRL, ILLUDAS and SWMM, but the peak times were similar to all models. The conveyance coefficient to examine the conveyance of the existing drainage network was 0.94-1.37, which means insecure, in Geucknak-chun drainage basin and 0.69-1.16, which means secure, in sangmu drainage basin.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2543-2546
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• 2015

Purpose: Percutaneous transhepatic biliary drainage (PTBD) is a form of palliative care for patients with malignant obstructive jaundice. We here compared the infection incidence between internal-external and external drainage for patients with malignant obstructive jaundice. Methods: Patients with malignant obstructive jaundice without infection before surgery receiving internal-external or external drainage from January 2008 to July 2014 were recruited. According to percutaneous transhepatic cholangiography (PTC), if the guide wire could pass through the occlusion and enter the duodenum, we recommended internal-external drainage, and external drainage biliary drainage was set up if the occlusion was not crossed. All patients with infection after procedure received a cultivation of blood and a bile bacteriological test. Results: Among 110 patients with malignant obstructive jaundice, 22 (52.4%) were diagnosed with infection after the procedure in the internal-external drainage group, whereas 19 (27.9%) patients were so affected in the external drainage group, the difference being significant (p<0.05). In 8 patients (36.3%) in the internal-external group infection was controlled, as compared to 12 (63.1%) in the external group (p< 0.05). The mortality rate for patients with infection not controlled in internal-external group in one month was 42.8%, while this rate in external group was 28.6% (p< 0.05). Conclusion: External drainage is a good choice, which could significantly reduce the chance of biliary infection caused by bacteria, and decrease the mortality rate at one month and improve the long-term prognosis.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.403-411
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• 2013

This study was performed to examine whether it is possible to promote rice growth by midsummer drainage without damage of golden apple snails in environment-friendly rice farming. The effect of drainage on the life of snails was examined in a greenhouse before the filed experiment. Spats (young shells) of snails survived 100% at 12 days after drainage, and 93.3% at 15 days after drainage. The midsized shells survived 100% at 9 days, 93.3% at 12 days, and 86.6% at 15 days after drainage. In the field experiment, 10-days drainage did not affect the snail population and there was no significant difference of weeding activity of snails between the midsummer drainage treatment and the continuous submerged treatment. The plant height and the effective tiller number in the midsummer drainage treatment were higher than those of the continuous submerged treatment. The rice yield of midsummer drainage plot was 511kg/10a, which was 66kg/10a higher than 445kg/10a of continuous submerged plot. In conclusion, midsummer drainage could increase rice growth and yield without damage of golden apple snails in the environment-friendly rice farming.

• Journal of the Korean GEO-environmental Society
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• v.24 no.11
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• pp.25-31
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• 2023

Horizontal drainage, which are representative dewatering method of domestic and foreign slope, are applied to reducing pore water pressure. Accordingly, several previous studies have been conducted, but horizontal drainage are standardized which is an unclean standard for a quantity calculation in filed. Therefore, this study presents field soil and laboratory model box to identify a drainage performance and influencing factors of various horizontal drainage. Furthermore, this study verifies the performance comparison of drainage shape or size according to different particle size distributions. In the outflow results for steady state, the study found that all samples are drained at a constant rate after a minimum of 3 minutes to maximum of 15 minutes. In the case of comparing the outflow per hour (Unit flux) in coarse grained soils, it found that drainage shape and size affect drainage performance. In the result, the future expected to be used basic data that experiment of drainage performance on fine grained soils and determine the quantity.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.99-106
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• 1999

This research was carried out to investigate chemical pretreatment using lime and limestone in treating abandoned mine drainage with anaerobic treatment. If treating lime with abandoned mine drainage, after 2day, pH was increased to 5.6, and $SO_4^{2-}$, Fe, Al, Pb and Mn were removed 5.7%, 63%, 57, 45% and 28%, respectively. It was estimated that lime dosage was 2,000mg/L for increasing to pH 7. If treating limestone with abandoned mine drainage, after 2day, pH was increased to 3.67, and $SO_4^{2-}$, Fe, Al, Pb and Mn were removed 4.7%, 26%, 22% 18% and 8%, respectively. It could be showed that limestone did slowly react with temperature increasing. If treating anaerobic limestone packing column with abandoned mine drainage, for experimental period, average pH was 4.51, and average $SO_4^{2-}$, Fe, Al, Pb and Mn were removed 4.5%, 15.3%, 20.1%, 23.7% and 5.87%, respectively. So, it would not be suitable for abandoned mine drainage. But if utilizing limestone as pretreatment process for treating abandoned mine drainage with SRB, because it did initally neutralize abandoned mine drainage, it could forward to stabilize system.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.75-83
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• 2013

PURPOSES: In this study, flood mitigation effect of drainage asphalt concrete pavement were analyzed by a SWMM 5.0 program in order to evaluate the low impact development (LID) based on the drainage asphalt concrete pavements. METHODS: In order to determine the porosity parameters of drainage asphalt concretes, the specimen mixtures were manufactured using the conditions presented in the previous study. The numerical simulation was conducted using the SWMM 5.0 program considering the flood mitigation effect of drainage asphalt concrete pavements. The effect of flood reduction can be observed when drainage asphalt concrete pavements were applied to Mokgamcheon watershed. The flood mitigation effect analysis of Mokgamcheon watershed as well as continuous simulation of subwatershed runoff were performed through this study. RESULTS : The analysis of drainage asphalt concrete pavements was carried out for evaluating the effect on runoff, resulting in: the peak flow decreases up to 1.26~9.53% after drainage asphalt concrete pavements applied in the SWMM 5.0 program furthermore, the discharge decreases up to 0.55~4.11%. CONCLUSIONS: As a result, the reduced peak flow and discharge were found through the SWMM 5.0 program. It can be concluded that the flood is effectively reduced when the drainage asphalt concrete pavements are used.

• KCID journal
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• v.21 no.1
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• pp.32-44
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• 2014

In Korea, global warming caused by the climate changes impacted on weather system with increase in frequency and intensity of precipitation, and the rainfall pattern changes significantly by regional groups. Furthermore, it is expected that the regional and annual fluctuation ranges of the rainfall in the future would be more severe. Nowadays, agricultural drainage system designed by the existing standard of 20-year return period and 2 days of fixation time cannot deal with the increment rainfall such as localized heavy rain and local torrential rainfalls. Therefore, it is required to reinforce the standard of the drainage system in order to reduce the agricultural flood damage brought by unusual weather. In addition, it is needed to improve the standard of agricultural drainage design in order to cultivate farm products in paddy fields as facility vegetable cultivation and up-land field crop have been damaged by the moisture injury and flooding. In order to prepare for the changes of rainfall pattern due to climate changes and improve the agricultural drainage design standards by the increase of cultivating farm products, the purpose of this study is to examine the impact of climate changes, the changes of relative design standard, and the analytic situation of agricultural flood damages, to consider the drainage design standard revision, and finally to prepare for enhanced agricultural drainage design standards.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.4
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• pp.125-136
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• 1996

In order to investigate the characteristics of gravity drainage for geotextile, small-scale model tests for the geotextile chimney drain of earth dam which is a typical type of gravity drainage were carried out using 15 kinds of nonwoven and composite geotextiles. According to the results of this study, the drainage discharge of geotexgile drain generally increases with exponential function as hydraulic head increases and the increasing rate is greater in the coarser soil of dam material. It has a trend to increase when the construction slope of geotextile drain is steeper and the number of layers of geotextile is more. The relationship between the transmissivity of geotextile and the drainage discharge has positive correlation and the rate of increase is greater in the coarser soil. The geotextile products must be carefully selected in consideration of transmissivity of geotextile when the soil to be drained is coarser and the seepage flow is relatively high. Most of staple fiber nonwoven geotextile used in this study are found to be appropriate for drainage purpose. Among them, the composite geotextile the type of which geotextile is evaluated to be the most excellent material. But the geotextile of low permeability such as filament thermal bonded and filament spunbonded nowovens closely examined their transmissivity especially to be used for drainage function.

• Journal of the Korean Geosynthetics Society
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• v.7 no.1
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• pp.31-37
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• 2008

The settlement occurring during landfill construction often causes a damage of drainage system. Clogging can reduce the hydraulic conductivity of the Leachate Collection and Drainage System, which results in the increase of leachate level within the landfill. Consequently, the insulation ability of leachate will be decreased. The main purpose of this project is to estimate a newly designed reinforced drainage geotextile (RDG) combining non-woven fabrics with geogrid for minimizing the destruction of drainage layer as well as evaluating RDG's application in the leachate collection and drainage system. Thus, the project observed the permittivity changes of RDG, and evaluated the drainage ability using RDG in the leachate collection and drainage system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.11
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• pp.789-796
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• 2007

It has been noted, in case of the apartments in collective form, the drainage noise from cleaning of toilet causes many problems in the basement and adjacent rooms, mainly hampering the pleasant housing environment. The problems are increasingly raised by civil complaints with the public offices. Therefore, if the drainage noise generates when wash out of toilet bowl is grasped how the characteristics change according to the sorts of drainpipe, it is considered that the establishment of an effective sound insulation countermeasure could be possible when a civil petition against the drainage noise of apartment house is submitted hereafter. On such viewpoint, this study measured and analyzed the characteristics of drainage noise per the type of drainage pipe, according to KS A ISO $1996-1{\sim}3$, with the horizontal branch pipe and riser pipes in the drainage noise experiment chamber which has the characteristics of the anechoic room. In the result, the pipe type with excellent noise reduction function. The result of this study is considered to become available as fundamental data, to take actions on reduction of drainage noise of the ceiling piping method.