• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.481-484
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• 2003

Sulfide minerals contacted with air and water in coal seam cause oxidation reactions. This oxidation reactions make low pH of groundwater and surface water(Acid Drainage). The reddish brown precipitate collected from the cut slope of the study area was estimated using the X-Ray Diffractometer(XRD). XRD results show that the cut slope was affected by Acid Drainage. The cut slope exposured to Acid Drainage become weak about chemical weathering and defile the appearance of the road. Drainage facilities are very important in Cut Slope under Acid Drainage influence. Reactions between Coal seam and water cause chemical weathering and environmental problem. Therefore It is important to control the transfer paths of groundwater and surface water and to install water collecting facilities

• Journal of Power System Engineering
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• v.20 no.5
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• pp.72-77
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• 2016

The present study investigates noise and condensation characteristics of polyvinyl chloride (PVC), which is widely used for drainage piping materials, complex double structure by comparing to those of PVC single structure piping materials. In addition, effects of insulation on drainage noise has been measured experimentally. As the results of the experiments, noise reduction effect of PVC complex double structure is superior to that of PVC single structure in terms of elbow and vertical piping materials which are employed for drainage pipes of toilet bowls and bathtub. The insulation barely have effect on the noise reduction in case of the PVC single structure since there is almost no changes in noise occurrence even though the insulation is applied on both elbow and vertical piping materials. Temperature differences between inside and outside of the pipes have been measures for the PVC single and complex double structures as well. In consequence, outside temperature of the PVC complex double structure is higher than that of the PVC single structure. The condensation occurrence time of the PVC complex double structure shows a distinct difference from that of the PVC single structure, thus, the PVC complex double structure has outstanding effect on preventing the condensation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.485-490
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• 2009

The present study has been conducted to accomplish the investment and analysis, to make the construction manuals, to draw the standards, and to build quality and standards informations of the plumbing/drainage facilities materials. The application plan and the anticipation effect of this results include as follows. (1) The investment and analysis of the plumbing/drainage facilities materials is able to suggest the technology trends and the trends analysis in the construction materials. (2) The quality and standards informations of the plumbing/drainage facilities materials are possible to be the construction faculty and the cost/energy reduction in the construction materials. (3) The standards methods of the plumbing/drainage facilities materials are useful for the reliability guarantee and quality escalation in the construction materials. (4) The standard manuals of the plumbing/drainage facilities materials are applied to the specifications in the construction materials.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.25-33
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• 1999

A great difference in drainage time was observed from the recycled stocks between corrugated container board and its component papers, liner and medium paper. It could be assumed that the different drainage property should be caused from a starch adhesive present in the corrugated board. Thus, three types of starch such as dried Stein-Hall adhesive, cooked starch solution, and its dried film were added to linerboard stock in order to investigate the mechanism of drainage reduction. The water-swollen starch particles derived from Stein-Hall adhesive were drastically deteriorated the drainage time, even though the amount of starch is very small (2% or below). The drainage time of OCC was improved by 25% when amylase was used a new biological treatment. The results from the lab and mill test showed that the starch-degradable enzymatic treatment improves the drainage property as well as the reduction of calcium hardness.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.4
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• pp.47-53
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• 2012

It is needed to install a one-way drainage filter to prevent a seepage from lake or river outside of embankment and to promote a drainage from a flood inside of embankment when dikes such as lake dike, river dike, etc are constructed. However, the results of research for one-way drainage filter are insufficient. Therefore, through the field test of one-way drainage filter, this study checked a function of one-way drainage filter with a test of performance. As a result of field test, water flow in dike was blocked in the interception direction of the section that one-way drainage filter was installed, but water passed to the flow allowance direction of the section. Therefore we confirmed the function of one-way drainage filter. Seepage quantity in the flow allowance direction of the one-way drainage filter section was low as 74.6~80.5 % than that in the section without installation of filter because of a reduction effect of seepage with filter. And seepage quantity of field test was low as 64.3~90.0 % than that in results of seepage analysis because the coefficient of permeability of embankment in field is different from the results of laboratory test. In the future, more study will be needed to solve several problems which are related to fix the filter on slide, durability of filter, etc.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.37-42
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• 2011

Recently, the cause of flood damage has been the local torrential rainfalls rather than a total amount of yearly rainfalls. The domestic design code of drainage pump is being improved by considering the effect of local torrential rainfalls, while there is no consideration on the local torrential rainfalls in the domestic design code of bridge-deck drainage. Compared with the code of Federal Highway Administration in USA, no rational bases are specified in the domestic design code of bridge-deck drainage. This paper proposes the reasonable design guideline for bridge-deck drainage considering the effect of local torrential rainfalls.

• Tunnel and Underground Space
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• v.18 no.1
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• pp.10-19
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• 2008

Most of flooding cases in tunnels are associated with huge inrushes of water due to the fracture zone with very high water head. To find out the causes and countermeasures for flooding cases, a dozen of tunneling cases are studied. Case studies presented here show that if the flooding had been forecasted and pre-drained prior to the tunnel excavation, such accidents could have been prevented. From this observation, we suggest a new horizontal drainage system with pre-investigation and pre-drainage concept. Seepage analyses are performed to analyze the water head reduction effect on the tunnel face by drainage pipes during the construction of subsea tunnels. Drainage system analyses are performed to analyze performance of the drainage system. These analysis results show that the suggested horizontal pre-drainage system provides a clear drainage and water head reducing effect. Finally, the proposed system can be a new alternative to the present water controlling methods applied to subsea tunnels.

• Archives of Plastic Surgery
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• v.48 no.6
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• pp.583-589
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• 2021

Background In prosthesis-based breast reconstruction patients, the drain tends to be kept in place longer than in patients who undergo only mastectomy. Postoperative arm exercise also increases the drainage volume. However, to preserve shoulder function, early exercise is recommended. In this study, we investigated the effect of early exercise on the total drainage volume and drain duration in these patients. Methods We designed a prospective randomized trial involving 56 patients who underwent immediate breast reconstruction following mastectomy using tissue expanders. In each group, the patients were randomized either to perform early arm exercises using specific shoulder movement guidelines 2 days after surgery or to restrict arm movement above the shoulder height until drain removal. The drain duration and the total amount of drainage were the primary endpoints. Results There were no significant differences in age, height, weight, body mass index, or mastectomy specimen weight between the two groups. The total amount of drainage was 1,497 mL in the early exercise group and 1,336 mL in the exercise restriction group. The duration until complete removal of the drains was 19.71 days in the early exercise group and 17.11 days in the exercise restriction group. Conclusions Exercise restriction after breast reconstruction did not lead to a significant difference in the drainage volume or the average time until drain removal. Thus, early exercise is recommended for improved shoulder mobility postoperatively. More long-term studies are needed to determine the effect of early exercise on shoulder mobility in prosthesis-based breast reconstruction patients.

• Journal of the Korean Geosynthetics Society
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• v.15 no.1
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• pp.11-19
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• 2016

This paper presents the results of a scale model test to the effect of heat exchanger drainage method in retaining wall of weathered granite soil. Purpose to rise in the temperature of the heat wires inside the weathered granite soil is preventing the collapse of the retaining wall and drainage smoothly moved to the drainage layer. Especially using a spray gun to simulate the rainfall since the rainfall drainage work is important for the rainfall effect on soil, find the difference about displacement of the retaining wall, change of volume water content, drainage, earth pressure and change in the strain of the geosynthetic was effected to heat exchanger within the soil. The result from applying the heat exchanger method decreased the earth pressure and displacement of the wall and increased drainage of water.

• KCID journal
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• v.19 no.1
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• pp.64-76
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• 2012

Recently, it has been increased disaster of crops and agricultural facilities with climate change such as regional storm, typhoon. However agricultural facilities have unsafe design criteria of improving drainage corresponding to this change. This study has analyzed the impact that inundation area and magnitude of drainage-facility is decided based on fixed- and unfixed-duration precipitation by applying revised design criteria of drainage for climate change. The result was shown that 1-day and 2-days rainfall for 20-years return period has increased about 11.4%, 4.4% respectively by changing fixed- to unfixed duration. And the increase rate of design flood was 15.0%. The result was also shown that Inundation area was enlarged by 6.6% as well as increased inundation duration under same basic condition in designed rainfall between fixed- and unfixed-duration. According to the analysis, it is necessary for pump capacity in unfixed-duration to be increased by 70% for same effect with fixed-duration. Therefore, when computing method of probability precipitation is changed from fixed one to unfixed-duration by applying revised design criteria, there seems to be improving effect in drainage design. Because 1440-minutes rainfall for 20-years return period with unfixed-duration is more effective than 1-day rainfall for 30-years return period with fixed-duration. By applying unfixed-duration rainfall, capacity of drainage facilities need to be expanded to achieve the same effects (Inundation depth & duration) with fixed-duration rainfall. Further study is required for considering each condition of climate, topography and drainage by applying revised design criteria.