• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.4
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• pp.11-21
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• 2000

This study was aimed to establish different drainage types of soil media on the plant growing in rooftop. For this study, experiment plots were installed on the roof of Social Science building, Chongju University, from April, 1998 to September, 1999. (1) Sand and sandy loam as base and check soils, (2) vermiculite as a inorganic soil media (3) "humus sawdust" and "burned rice hull" as organic soil media were used by various mixing ratio Zoysia japonica, was selected for the experiment. The results of this study are as follows : L5B3S2 and L5H3S2 of bad drainage character with a plastic drainage plate combination caused good growth effect on Zoysia japonica examined in 3 types of drainage layer with 5 types of soil media. From this result, it could be suggested that combined design of plastic drainage plate with 2 soil types - L5B3S2 and L5H3S2 - be desirable composition for regarding weight load and plant growth.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.2
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• pp.102-112
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• 2003

This study was carried out to research and develop a shallow green rooftop system which would require low maintenance and therefore could be used for existing rooftops. To achieve these goals, the conceptual model was induced by past studies and the experimental systems were deduced from the conceptual model. On the growth of Sedum sarmentosum grown in these rooftop systems, the effects of artificial substrate type, soil depth, and drainage type were investigated from 3 April to 11 October 2002. Artificial substrates were an alone type and a blending type. The alone type was an artificial substrate formulated by blending crushed porous glass with bark(v/v, 6:4). The blending type was formulated by blending the alone type with loam(v/v, 1:1). Soil depths were 5cm, loom, and 15cm. Drainage types were a reservoir-drainage type and a drainage type. The reservoir-drainage type could keep water and drain excessive water at the same time. The drainage type could drain excessive water but could not keep water. Covering area, total fresh and dry weight, visual quality, and water content per 1g dry matter were measured. All the variables were analyzed by correlation analysis and factor analysis. The results of the study are summarized as follows. The growth increment was higher in the blending type than in the alone type, the highest in loom soil depth and higher in the reservoir-drainage type than in the drainage type. The growth quality was higher in the blending type than in the alone type, the highest in l0cm soil depth, and higher in the drainage type than in the reservoir-drainage type. In consideration of the permissible load on the existing rooftops and the effects of the treatments on the growth increment and quality, the system should adopt the blending type in artificial substrate types, 5~10cm in soil depths, and the drainage type in drainage types. This system will be well-suited to the growth of Sedum sarmentosum, and when the artificial substrate was in field capacity, the weight will be 75~115kg/$m^2$.

• KCID journal
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• v.14 no.1
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• pp.67-79
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• 2007

Concrete repair and reinforcement is a complex process, presenting unique challenges very different from those experience in the field of construction. The purpose of this study is to analyze the pattern and mechanism of deteriorations in irrigation and drainage structure. Damage and deteriorated structures are classified with several types. This provides a survey of crack repair methods, including a summary of the procedures that are being used. It is systematically evaluated with the disintegration on irrigation & drainage structure; drainage sluice gate, pumping station, drainage pumping station. Following the evaluation of the irrigation & drainage structure, a suitable repair and reinforcing procedure can be selected based on this report

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.263-273
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• 2020

With the change of the agricultural environment (increased rice production, decreased rice consumption, and rice production policies), converting paddy fields into upland fields is an increasing trend. In terms of conversion into upland fields, subsurface drainage is one of the most important factors for good field crop growth. This study evaluates the performance of a subsurface drainage culvert system in paddy fields and reclaimed lands. The obtained results are briefly summarized as follows: 1) After a comparative evaluation of several subsurface drainage culvert systems, including excavated subsurface drainage and non-excavated subsurface drainage types, type 3 (non-excavated, perforated drain pipe 50 mm, filter mat B50 cm, subsoiling 70 cm and culvert spacing 5 m) shows relatively high values among four types in terms of effectiveness (subsurface discharge capability) and economic efficiency (construction cost). 2) Type 3 has proven that it is suitable for design standards of discharge capacity through field tests performed in paddy fields (three sites: Gong-geom, Gae-san, Juk-san) and reclaimed lands (two sites: Gum-ho, Mi-am). 3) In the experiment of Sesamum indicum growth according to the existence of a drainage system, Sesamum indicum growth with a subsurface drainage culvert system had good value in terms of plant shoot and root length, shoot fresh and dry weight, and root fresh and dry weight).

• Journal of Environmental Science International
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• v.29 no.11
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• pp.1109-1123
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• 2020

In this study, the amount of harmful fungi and bacteria contained in the drainage and culture medium from the paprika hydroponic facility is identified. In addition, by proposing the necessity of effective purification of discharged drainage, this study attempted to confirm the possibility of drainage reuse. Finally, this study provides basic data on the basis for calculating the need for purification facilities in the future, as well as improvements in horticulture facility for sustainable agriculture. As a result of the analysis, a total of 12 types of fungi were detected in paprika medium and 10 types of fungi were detected in the drainage, and their densities were 130 and 68, respectively. Among the fungi detected in the media and drainage of the paprika hydroponic facility, the fungi with the highest detection frequency are Fusarium, Phytophthora, and Pythium. In the case of bacteria, a total of 2 types of bacteria were detected in the paprika facilities, and the density was 28 and 23, respectively. Therefore, in order to reuse the drainage and settle the circulating hydroponic cultivation system, a water treatment process capable of appropriate treatment is required.

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.47-57
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• 2018

PURPOSES : The permeable pavement type has been rapidly developed for solving problems regarding traffic noise in the area of housing complex and heavy rainwater drainage in order to account for the climate change. In this regards, the objective of this study is to figure out the characteristics of pavement types. METHODS : The laboratory test for deriving optimum asphalt content (OAC) was conducted using the mixtures of the permeable asphalt surface for the pavement surface from Marshall compaction method. Based on its results, the pavement construction at the test field was conducted. After that, the site performance tests for measuring the traffic noise, strength and permeability were carried out for the relative evaluation in 2 months after the traffic opening. The specific site tests are noble close proximity method (NCPX), Light falling deflectometer test (LFWD) and the compact permeability test. RESULTS : The ordered highest values of the traffic noise level can be found such as normal dense graded asphalt, drainage and porous structure types. In the results from LFWD, the strength values of the porous and drainage asphalt types had been lower, but the strength of normal asphalt structure had relatively stayed high. CONCLUSIONS :The porous structure has been shown to perform significantly better in permeability and noise reduction than others. In addition to this study, the evaluation of the properties and the determination of the optimum thickness for the subgrade course under the porous pavement will be conducted using ground investigation technique in the further research.

• 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 Manufacturing Process Engineers
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• v.16 no.2
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• pp.34-43
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• 2017

Large amounts of household water are required as common households change from the single-residence types of the past to group-residence types. Therefore, the management of reservoirs is urgently required to ensure the supply of clean household water to users. Important considerations for household water include the duration for which the water is stored in the reservoir, the disinfectant's dilution capacity, and the size of the reservoir to allow for the amount of water required for emergencies and firefighting. The drainage efficiency was analyzed in this study using computational fluid analysis for existing rectangular reservoirs and the newly proposed hexagonal reservoir. Thus, it was determined that the centrifugal force generated at the inlet was maintained until the outlet due to the approximately circular shape of the hexagonal reservoir. The findings of this study verified that the centrifugal force improved the flow rate by approximately 35% compared to existing rectangular reservoirs and that drainage was performed efficiently without stagnation zone.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.65-74
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• 2015

In order to design an advanced composite materials drainage pipe structures for an undersea tunnel, mechanical properties for the lamina types of the structural member must be predetermined. It is also reported that the size effect of the specimen is significant. In this study the tensile tests for the lamina types of the structural member are conducted at the room temperature ($20^{\circ}C$) and the seawater temperature ($0^{\circ}C$). In addition, the mechanical properties are predicted by theory based on the rule of mixtures and elasticity solution technique. The predicted mechanical properties are compared with test results obtained by a test method. In the design of an advanced composite materials drainage pipe structural members for an undersea tunnel, the used mechanical properties must be applied at the room temperature with considering the modified factors. These are to be offered the datum for the design an advanced composite materials drainage pipe structures for an undersea tunnel.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.3
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• pp.52-59
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• 2004

The greater Increase of the demand for environmental friendly materials especially for packaging industry leads to the larger interest in the reusable and recycable materials such as pulp mold. Although the pulp mold has great characteristics for packaging, some deficiency compared with other packaging material like EPS(Expandable Polystyrene) need to be overcome, for example, the relative higher cost. In this report, since the water drainage rate at the forming zone of a wet pulp mold process could have a great influence on the economical efficiency not only by increasing machine speed but also reducing the drying energy, the optimum ways for increasing drainage were investigated The mechanism of vacuum drainage In pulp mold forming was successfully evaluated by using RDA(Retention and Darinage Analyzer). Since the conditions of stock were greatly affected by the pulping time of low consistency pulper, the optimum pupling time was investigated with considerations of all stock preparation processes. The change of stock temperature and the addition of polyelectrolyte could improve the vacuum drainage rate. It was founded that the wire mesh types of mold former had a little influence on the retention because of the relatively mild vacuum drainage. However, the bigger size of dewatering hole showed better drainage rate and could reduce the plugging and con lamination of mold.