• Journal of the Korean GEO-environmental Society
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• v.24 no.8
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• pp.5-11
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• 2023

Due to frequent occurrences of concentrated heavy rainfall caused by abnormal climate conditions in recent years, collapses of steep slopes have been occurring frequently due to surface erosion and increased pore water pressure. Various methods are being applied to prevent slope collapses, such as increasing the resistance to movement and reducing pore water pressure. Research on these methods has been consistently conducted as they provide an efficient response to slope collapses by satisfying both the conditions of resistance to movement and pore water pressure simultaneously. Therefore, in this study, we propose an upward slope reinforcement method by burying drainage materials with an upward slope inclination, instead of the conventional horizontal application. This approach aims to satisfy both slope reinforcement and drainage functions effectively, offering a comprehensive solution for slope stabilization. Furthermore, to determine the optimal burial angle that exhibits the most effective reinforcement and drainage effects of the proposed method, we investigated the reinforcement and drainage effects under conditions where the horizontal drainage materials were set at angles ranging from 0° to 60° in increments of 10° on a representative cross-section. Additionally, indoor model experiments were conducted under the conditions of 40°, which showed the most outstanding drainage effect, and 20°, which exhibited the highest safety factor, to validate the numerical analysis results. The results showed that the burial angle of 40° exhibits a relatively higher drainage effect as with the numerical analysis results, while the angle of 20° results in inadequate drainage and observed slope collapse.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1328-1332
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• 2000

We present a modified method for the treatment of brain abscess. The double lumen extraventricular drainage (EVD) catheter which was developed for the intracerebral hematoma management, was applied for the treatment of brain abscess drainage. We placed the double lumen EVD catheter into the abscess cavity by free-hand technique and irrigated the abscess cavity continuously with antibiotics solution for 7 days. Simultaneous intravenous antibiotics was administered for 4 weeks. The continuous irrigation with double lumen catheter was found to be safe and effective treatment modality in the brain abscess.

• KCID journal
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• v.13 no.2
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• pp.246-253
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• 2006

Experimental laboratory tests were carried out to assess the effect of fine content and salinity of soils on the measurement of TDR(Time Domain Reflectometry). In the test, using soil columm which was made by PVC pipe with the dimension of 25cm height and 20cm diameter, the salinity variation of soil was controlled by the solution which was dissolved NaCl to destilled water in the range of 0-40g.$L^-1$. The fine content of soil was controlled by kaolinite which was mixed with Jumunjin sand in the range of 0-50% to the total dry weight. The water contents of soil tested were measured with the conventional oven dry method beside TDR and compared the these values to figure out the extent of effect. As the results of tests, it was appeared that the water content measurement by TDR can be affected by the salinity level, fine contents, and the degree of saturation of the soil.

• The International Journal of Costume Culture
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• v.4 no.1
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• pp.18-24
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• 2001

Agricultural drainage salt generated during irrigation of crops in San Joaquin Valley, California, exceeds 600,000 tons annually and cumulates in the field in a rapid rate. As a result, the waste is taking out more farmlands for salt storage and disposal, imposing serious concerns to environment and local agricultural industry. In searching for a potential solution to reduce or eliminate the waste, this research explored feasibility of producing a value -added product, sodium sulfate, from the waste and utilizing the product in textile dyeing. The results indicated that sodium sulfate could be produced from the salt and could be purified by a recrystalization method in a temperature range within the highest and lowest daily temperatures in summer in the alley. The recovered sodium sulfate samples, with purities ranging from 67% to 99.91, were compared with commercially available sodium sulfate in direct dyeing of cotton fabrics. The salt samples recovered from Mendata, California (〉98.8% sodium sulfate) cause little color difference in the dyeing with selected direct dyes, and the purified salt (Ⅲ) (99.91% sodium sulfate) is more applicable for direct dyeing of cotton fabrics if it has no other toxic effects. The recovered sodium sulfate from certain areas in the valley could not be employed in direct dyeing due to the high level of impurities in it.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.170-180
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• 2000

The surface-drainage system, which consists of bio-swale and detention-infiltration Basins and carries out the function of temporary detention-infiltration of runoff, is defined as the "natural drainage system". It is an environmentally sound and economically beneficial practice to reduce run-off by retaining it in swales as much as possible and letting run-off infiltrate into the ground. In order to estimate appropriate capacity of swales, it is necessary to know how long will it take for certain depths of water to infiltrate. The ponding times, or infiltration times, of various depths and of various soil textures, could be estimated with the Green-Ampt Infiltration Model. Included soil textures are loamy sand, sandy loam, loam, silty loam, sandy clay loam and clay loam. Ponding depths are from 10cm to 100cm intervals. Newton-Raphson method is used for the solution of the Green-Ampt equation by a computer program. The computer program was written with the FORTRAN Developer 4.0 v.. Selected ponding depth is acceptable when the sum of the ponding time and the breeding time of mosquitoes is less than the tolerance period of innundation of grasses and trees.and trees.

• Water Engineering Research
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• v.2 no.4
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• pp.269-276
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• 2001

The project concentrates on an hydrological analysis. The analysis consists of rainfall, infiltration, Determination of runoff and sediment yield. The risque of erosion and the control measures are related to the slopes and land use. Therefore the first approach to erosion must be correct land use based on land classification. Basically there are two types of mechanical protection works; Drainage and Storage. Realization of a drainage system will be very costly and therefore temporary storage is preferred. For farmland in flat areas hardly any measures are needed. For farmland on slopes temporary storage can be effected by applying tillage with ridges within contour bunds. Along roads infiltration pits should be constructed and in areas with houses, the solution to avoid runoff will be water harvesting.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.208-213
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• 2011

Seoul Metropolitan Rapid Transit Corporation has 148's stations. Total length is 152km and most of the station is located in the basement and Groundwater occur inflow of 700,000 tons per day. Groundwater is treated as a natural flow way instead of artificial ways. Therefore, most of the collection wells is located in the low place or station for the efficient induction and collecting water. Manhole overtopping is occurring frequently because groundwater is concentrated in the drain pipe near the collecting well and heavy rainfall in summer. As a result, ballast contamination and radon levels are increased in tunnel. This paper introduces a solution is increasing overflow in tunnel, which introduces drainage system of non-motorized that uses differencial head between collecting well and manhole.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.224-229
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• 1998

This study was conducted to develop the simple and convenient irrigation control model which can maintain the appropriate rates of irrigation and drainage of nutrient solution according to the environmental conditions and growth stages in soilless culture of cucumber. In order to obtain fundamental data for development of the model, investigation of the actual state of soilless culture practices was carried out. Most irrigation systems of soilless culture were controlled by the time clock. Evapotranspiration of cucumber in soilless culture was investigated and correlations with environmental conditions were analyzed, and its prediction model was developed. A irrigation control model based on the time clock control and there were considered seasons, weather conditions, and growth stages was developed. Applicability of the model was tested by simulation. Drainage rates of irrigation system controlled by conventional time clock, integrated solar radiation, and the developed model were 61%, 20%, and 32%, respectively in cucumber perlite culture.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.125-128
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• 2010

A large quantity of purified water sludge is generated in modern cities around the world. Dewatering is essential to reduce the volumes transported off-site for disposal. Traditionally employed methods such as solar drying methods are time-consuming. There are urgent demands for developing alternatives to dewater the sludge in a less time-consuming manner. In this paper, siphon method is proposed to dewater the high-water-content sludge with plastic drainage plate installed horizontally. A group of comparative tests are conducted to preliminarily investigate the dewatering behavior of the purified water sludge with siphon and solar drying methods, respectively. On the basis of the test results, the availability and effectiveness of the new method is verified. It may provide an innovative solution to treat the purified water sludge more effectively.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.129-133
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• 2000

The objective of this study was to invetigate the coagulation effects of landfill leachate by using Acid Mine Drainage(AND). The coagulation efficiency was investigated by mixing landfill leachate with F $e^{+3}$ solution earned by oxidation of pyrite(AMD). In the results of this experiment, it was found that the amount of removed COD and SS was approximately 30% respectively by mixing at the ratio of AMD three to leachate one. And it showed highest turbidity removal efficiency at all mixing ratio. Concentration of Fe was decreased with increasing mixing ratio, however it was increased inversely at mixing ratio 4. Optimal mixing ratio was 3 at the results obtained by leachate coagulation experiments. Also removal efficiency at mixing ratio 3 corresponded to 500mg/$\ell$ of FeC $l_3$ dosage. it was suggested that pretreatment by mixing of AMD and leachate remove both suspended organic material of leachate and metal of AMD.