• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.324-329
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• 2008

A coal mine drainage sludge(designated as CMDS) is mainly generated during physicochemical treatment or electrical purification of the drainage abandoned mine that include dissolved heavy metal. To understand the possibility of an application of the dehydrated CMDS as the landfill cover medium of hygienic a reclaimed ground, an laboratory experiment was performed to investigate the physicochemical and geoengineering characteristics of the dehydrated CMDS. To improve the geoengineering characteristics of the dehydrated CMDS, the liquid limit, plasticity limit test, compaction method test, strength test, and hydraulic conductivity test ware performed with the lithification material mixed sludge. When the mixed ratio of the sludge and the lithification material was more than 1:06, the compaction method was A method, the moisture content less than 33.5%, the strength of mixed sludge was $8.2kg\;cm^{-2}$, the hydraulic conductivity was $2.7\times10^{-6}cm\;sec^{-1}$, the sludge was up to the landfill standard of US Environmental Protection Agency (US EPA).

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.143-150
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• 2009

Material functions about effective stress, permeability, coefficient of consolidation and coefficient of volume change has important role to predict consolidation velocity and settlement of soft ground. Modified oedometer for radial drainage is adapted to find out material functions on laboratory tests. Undisturbed sample for laboratory tests were taken from construction sites of industrial complexes on southern coastal area which consists of upper dredged fill and lower original clay layer. For different drainage condition in consolidation process void ratio, effective stress, permeability, coefficient of consolidation and coefficient of volume change has been assessed with results of existing standard oedometer tests. It is worthwhile to note that consolidation material functions could be expressed as regression equation by Stark (2005), heterogeneity for permeability could be assessed from these relationships.

• Journal of the Korean Geosynthetics Society
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• v.15 no.2
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• pp.35-44
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• 2016

PET aggregates were produced by mixing heated PET flakes with frictional soils. Using these artificially-made PET aggregates, horizontal drain tests in the laboratory, pilot scale model tests were conducted for the evaluation of the drainage characteristics of PET aggregates. Laboratory horizontal drain tests were conducted under twenty different conditions varying mixing ratios and surcharged pressures. Moreover, by utilizing the aggregates with a mixing ratio producing the lowest variation in terms of permeability against applied load, large scale tests were performed. Reliability of the test results was evaluated from comparison with the results of the laboratory horizontal drain test.

• KCID journal
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• v.18 no.1
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• pp.4-17
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• 2011

The standard design methodology was suggested to construct wetland system for reducing non-point source pollution from Saemangeum reclaimed paddy land. To set for the design flow and concentrations, runoff and water quality survey were conducted during the irrigation period in 2008 at Gyehwa reclaimed paddy land located at near Saemangeum lake. It is rational that 1ha is the optimum constructed wetland size. To meet this size, the moderate drainage area of reclaimed paddy field was 50ha under the conditions that rainfall is 30mm, average runoff coefficient is 0.83, and runoff capture ratio is 0.6. At these condition, the runoff volume from 50ha was 10,520 $m^3/d$ including base flow during irrigation period. To select the optimum wetland system, several case studies were conducted by focusing on the tidal reclaimed land areas having wetland systems in Seokmun. Pond-Wetland system was selected as the standard model because of showing the highest reduction efficiency. Single variable regression equation were delivered to estimate effluent water concentrations from the designed wetland by using long-term monitoring data from the Seokmun experiment site. The effluent concentration from the designed wetland using these equation were showed moderately range.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.33.1-33.8
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• 2020

Background: We investigated the efficacy of a maxillary Jackson-Pratt (J-P) suction drain for preventing maxillary sinus hematoma and facial swelling after maxillary Le Fort I osteotomy (LF1). Methods: We retrospectively evaluated 66 patients who underwent LF1 at a single institution. Of these, 41 had a J-P suction tube inserted in the mandible and maxilla (maxillary insertion), and 25 had a J-P drain inserted in the mandible only (no maxillary insertion). Facial CT was obtained before and 4 days after surgery. We compared mean midfacial swelling and maxillary sinus haziness by t test and examined correlations between bleeding amount and body mass index (BMI). Results: For the maxillary-insertion group, the ratio of total maxillary sinus volume to haziness (57.5 ± 24.2%) was significantly lower than in the group without maxillary drain insertion (65.5% ± 20.3; P = .043). This latter group, however, did not have a significantly greater midfacial soft tissue volume (7575 mm³) than the maxillary-insertion group (7250 mm³; P = .728). BMI did not correlate significantly with bleeding amount or facial swelling. Conclusions: Suction drainage in the maxilla reduced maxillary sinus haziness after orthognathic surgery but did not significantly reduce midfacial swelling.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.403-410
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• 1979

A Clinical analysis of 64 patients of thoracic empyema was done who received surgical intervention at Dept. of Thoracic Surgery of the Chosun University Hospital in the period of 3 years from September 1976 to October 1979. Following was the results: 1. Seven cases [10.9%] were under the age of 15 years, 16 cases [25%] was between 15-30 years and 41 cases [64.1%] was above the age of 30 years. A proportion of children and adult was 1:8. 2. Male and female ratio was 3:1. Right and left side pleural cavity ratio was 2.4:1. 3. Predisposing factors were pneumonia [35.9%] and pulmonary tuberculosis [28.1%]. 4. Most frequently encountered symptoms were dyspnea, cough, chest pain and fever in order. 5. Etiologic organisms were confirmed in 39 cases [86.7%] which requested in 45 cases. Staphylococcal infections were 11 cases and streptococcal, pneumococcal pseudomonas infection was infected in order. 6. Pneumothorax was associated with empyema on 21 cases [32.8%]; among those 13 cases [61.9%] were tuberculous in nature. 7. Sensitivity test was revealed that Minocin was most very sensitive drug, and next Erythromycin, Gentamycin and Penbrex in order. But most resistant drugs were Penicillin, Kanamycin, Streptomycin and Tetracycline in order. 8. Treatments were combined with antibiotics therapy and several surgical procedures for empyema. 26 cases [40.6%] were treated with closed thoracotomy drainage, 17 cases [26.6%] with open thoracotomy tube drainage and 9 cases decortication and 9 cases thoracoplasty. 9. 2 death cases occurred in 64 cases of thoracic empyema, and 79.7% cases were discharged with recovery and improvement.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.157-166
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• 2012

Most of the roads are paved with impermeable materials such as asphalt concrete and cement concrete, and in the event of heavy rainfall, rainwater directly flows into river through a drainage hole on the pavement surface. This large quantity of rainwater directly spilled into the river frequently leads to the flooding of urban streams, damaging lowlands and the lower reaches of a river. In recent years there has been a great deal of ongoing research concerning water permeability and drainage in pavements. Accordingly, in this research, a porous polymer concrete was developed for permeable pavement by using unsaturated polyester resin as a binder, recycled aggregate as coarse aggregate, fly ash and blast furnace slag as filler, and its physical and mechanical properties were investigated. Also, 3 types of permeable polymer block by optimum mix design were developed and rainfall runoff reduction effects by permeability pavement using permeable polymer block were analyzed based on hydraulic experimental model. The infiltration volume, infiltration ratio, runoff initial time and runoff volume in permeability pavement with permeable polymer block of $300{\times}300{\times}80$ mm were evaluated for 50, 100 and 200mm/hr rainfall intensity.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.619-625
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• 2008

Urban sewer systems are designed to operate in open-channel flow regime and energy loss at square manholes is usually not significant. However, the energy loss at surcharged manholes is considered as one of the major causes of inundation in urban area. Therefore, it is necessary to analyze the head loss associated with manholes, especially in surcharged flow. Hydraulic experimental apparatus which can change the manhole inner profile(CASE I, II, III, and IV) and the invert types(CASE A, B, C) were installed for this study. The experimental discharge was $16{\ell}/sec$. As the ratio of b/D(manhole width/inflow pipe diameter) increases, head loss coefficient increases due to strong horizontal swirl motion. The head loss coefficients for CASE I, II, III, and IV were 0.46, 0.38, 0.28 and 0.37, respectively. Side covers increase considerably drainage capacity at surcharged square manhole when the ratio of d/D(side cover diameter/inflow pipe diameter) was 1.0. The head loss coefficients for CASE A, B, and C were 0.45, 0.37, and 0.30, respectively. Accordingly, U-invert is the most effective for energy loss reduction at surcharged square manhole. This head loss coefficients could be available to evaluate the urban sewer system with surcharged flow.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.73-81
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• 2021

The objective of this study was to analyze the waste nutrient generation loads from hydroponics for three major crops in Gyeongsangnam-do. Study hydroponic farms were selected for the three major crops such as paprika, strawberry, tomato based on the agricultural statistics data and field investigation. The flow amount and water quality for inflow and outflow of study hydroponic farms were monitored and analyzed on a monthly basis. Monitored samples were analyzed in terms of DO, BOD, T-N, T-P, SS, and EC. The generated load of BOD, T-N, and T-P were calculated from the monitored flow and water quality. The monitoring results showed that the drainage ratio for the circular hydroponic farm was lower than the non-circular hydroponic farm because the outflow from the circular hydroponics were much lower than that from the non-circular. The generated load calculation results showed that the BOD tended to have a smaller value than the TMDLs guideline for land, while T-N and T-P showed higher value than that from the TMDLs guideline. In order to effectively manage the pollutant load discharged from the hydroponics farming complex, it is necessary to manage the non-circulating hydroponics farm. To improve water quality, it is necessary to gradually expand the circulating hydroponics farm through policy and economic support.