• Water for future
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• v.14 no.4
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• pp.27-34
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• 1981

The design flow of the urban strom drainage systems has been assessed largely on a basis of empirical relations between rainfall and runoff, and the rational formula has been widely used for the cities in our country. In order to estimate it more accurately, the urban runoff simulation model based on the RRl method has been developed and applied to the sample basin in this study. The rainfall hyetograph of the design stromfor the design flow has been obtained by the determination of the total rainfall and the temporal distributions of that rainfall. The total rainfall has been assessed from the empirical formula of rainfall intensity and the temporal distribution of that rainfall determined on the basis of Huff's method from the historical rainfall data of the basin. The virtual inflow hydrograph to each inlet of the basin has been constructed by computing the series of discharges in each time increment, using design strom hyetograph and time-area diagram. The actual runoff hydrograph at the basin outlet has been computed from the virtual inflow hydrographs by developing a relations between discharge and storage for the watershed. The discharge data for verification of the simulated runoff hydrograph are not available in the sample basin and so the sensitivity analysis of the simulation model has not been possible. The peak discharge for the design of drainage systems has been estimated from the computed runoff hydrograph at the basin outlet and compared to thatl obtained form the rational formula.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.107-111
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• 2004

This study was undertaken to summarize of the efficiencies of the passive treatment system and suggest future studies for the solution of mine drainage problem. Flow rates of mine drainage from the abandoned coal mines are about 80,000 ton/day. Contaminated mine drainages over about 50 ton/day of flow rate were treated by passive treatment facilities such as Successive Alkalinity Producing Systems(SAPS), oxidation pond and oxic wetland. Chemical analysis for 13 passive coal mine treatment facilities showed that SAPS was the core of treatment facilities because the variation of Fe removal rates was relatively smaller than any other processes and re-leaching of Fe was not measured. The performance and life of SAPS depended on decrease in permeability and retention time due to accumulation of sludge. It is inferred that upgrade of design of the passive treatment system and in-situ treatment using underground void will be necessary for the amelioration of the mine drainage with high metal loading rates.

• Korean Journal of Bronchoesophagology
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• v.15 no.2
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• pp.64-70
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• 2009

Descending necrotizing mediastinitis(DNM) can occur as a complication of oropharyngeal and cervical infections that spread to the mediastinum via the cervical spaces. Delayed diagnosis and inadequate mediastinal drainage through a cervical or minor thoracic approach are the primary causes of a high mortality rate. Therefore, We emphasize that aggressive and emergent mediastinal drainage by surgical approach is most important method of DNM treatment. We studied 5cases diagnosed as DNM from 2005 through 2007. All patients underwent emergent surgical drainage of deep neck infection combined with mediastinal drainage through a thoracic approach. Primary oropharyngeal infection lead to DNM in four cases(80%) and odontogenic abscess in one case(20%). The outcomes were favorable 5patients. Overall mortality rate was 0%. The time interval from diagnosis based on manifestation of initial symptoms(oral or pharyngolaryngeal area) to surgical intervention was $7.4{\pm}4.2$days. One patient required reoperation due to remnant mediastinal abscess and pericardial effusion. Early diagnosis and emergent combined drainage with neck and chest incisions, together with broad spectrum intravenous antibiotics, should be considered standard care for this disease. And intensive postoperative care which it is continuous mediastinal irrigation and antibiotics use can significantly reduce the mortality rate.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.2
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• pp.123-134
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• 2013

Urban underground structures at low ground elevations (i.e. shallow substructures) unlike typical tunnel structures are subjected to low overburden and high water pressures. This often causes the underground structures to become damaged. Various conventional methods for the urban underpass structures such as dead weight increasement, round anchors, and tension piles, are significantly conservative and provok concerns about the costly, time-consuming installation process. Recently, permanent drainage system becomes to widely use for supplementing the conventional method's shortcomings, but, it is applied without the considerations for ground conditions and water table. In this study, therefore, numerical analyses are performed with various parameters such as groundwater level, wall height, and ground conditions in order to establish design guidelines for induced drainage system which is a kind of the permanent drainage method constructed at the Y-area. According to the numerical results, the induced drainage system is very effective in reducing the uplift pressure that acts on the base of underpass structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1192-1200
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• 2007

A general rainfall outflow in urban drainage has early time of concentration because urban drainage areas are most paved area. In general, rainfall outflow is flowed in drainage pump station and is discharged to rivers in urban areas. However it is excluded through drainage pumps about a heavy rainfall which exceed the design rainfall and the rainfall outflows increase the urban inundation risk. A current pump operation is control according to water level of collecting well or reservoir in drain pump station. But recently, the localized downpours are happened frequently in urban drainage and the current pump stations are frequently incapable of the heavy rainfall outflows. In this study, a real urban inundation was simulated and the drain capacity of drain pump station was evaluated by analysis about flood-factor in urban underground passage. Then the analysis about the inundation was done by the simulation about the real rainfall which cause the inundation. Also, in the simulation the inundation risk and the evaluation of flood-factor were analyzed according to change of the pump operation rule.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.1
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• pp.67-74
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• 2004

This study was carried out to investigate the characteristics of handsheets made from nonwoody New-Zealand hemp (Phormium tenax) fibers that was not used before in Korea. The results were as follows : 1. Physical properties of bleached phormium fiber were satisfactory for handsheet forming. Specially, tensile strength was improved by adding bleached phormium fiber. 2. Opacity of handsheet with phormium pulp was fine, therefore it can be useful fiber to improve opacity of light-weight printing paper. 3. Filler retention rate was improved when phormium pulp was added, while drainage time was increased. 4. Phormium fiber has good characteristics as pulp for paper manufacture. So it can be valuable non-wood fiber resource if drainage problem is solved.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.899-904
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• 1990

One hundred and nine Patients with thoracic empyema were treated at the Chosun university hospital from Jul. 1983 to Sep. 1989. Seventy-nine[72.5%] of the empyemas were adults and 30[27.5%] patients were under fifteen-year children. 29 patients[26.6%] were associated with pulmonary tuberculosis, 23[21.1%] occurred as pneumonia, and 13[11.9%] were unknown. The cardinal symptoms were dyspnea, chest pain, fever, coughing. When used as the initial mode of drainage, repeat thoracentesis was successful in only 46 of 93 cases[49. 5%]. Rib resection, however, provided cure or controlled in 7 cases[100%]. And decortication showed high cure rate in 19 of 24 cases[79.2%] Eventual control or cure of empyema was achieved in 90 patients[89.6%], whereas 7 patients[6.4%] died [3 from their empyema and 4 with empyema as an active problem at the time of death]. of all empyema-caused deaths occurred in patients who underwent chest tube drainage as the most invasive treatment modality. Chest tube drainage was often inadequate and more aggressive management was likely to result in fewer treatment failure and fewer total procedure. Early rib resection was recommended.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.1
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• pp.52-60
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• 1999

Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.193-199
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• 2005

The objective of this study was to investigate the characteristics of adhesion and detachment of algae on various materials of drainage canal in the sedimentation basin. The influence of surface washability, surface roughness, phosphorous concentration was studied using stainless steel, cement block and ceramic panel. The algae attached content of cement block was higher than that of the ceramic coating panel. The attachment varied significantly with respect to exposure time and different materials. the attachment was higher on rough surface (cement block) when compared to smooth surfaces. The content of attached algae increased with increasing phosphorous concentration in water. The detachment efficient of algae was higher on ceramic panel.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.99-108
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• 2018

An oil-tolerant and salt-resistant aqueous foam system was screened out as a possible lubricant to enable cold heavy oil transportation. The microstructures and viscoelasticity and effects of heavy oil, salt and temperature on the foam stability were investigated and new rheological and drainage models were established. The results indicate the foam with multilayered shells belongs to a special microcellular foam. The viscoelasticity could be neglected due to its low relaxation time. The drainage process can be divided into three stages. The foam with quality of 67.9% maintains great stability at high oil and salt concentrations and appropriate elevated temperature.