• Journal of Korean Neurosurgical Society
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• v.53 no.1
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• pp.59-61
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• 2013

Authors report a rare case of acute intracranial subdural and intraventricular hemorrhage that were caused by intracranial hypotension resulted from cerebrospinal fluid leakage through an unidentified dural tear site during spinal surgery. The initial brain computed tomography image showed acute hemorrhages combined with preexisting asymptomatic chronic subdural hemorrhage. One burr hole was made over the right parietal skull to drain intracranial hemorrhages and subsequent drainage of cerebrospinal fluid induced by closure of the durotomy site. Among various methods to treat cerebrospinal fluid leakage through unidentified dural injury site, primary repair and spinal subarachnoid drainage are well known treatment options. The brain imaging study to diagnose intracranial hemorrhage should be taken before selecting the treatment method, especially for spinal subarachnoid drainage. Similar mechanism to its spinal counterpart, cranial cerebrospinal fluid drainage has not been mentioned in previous article and could be another treatment option to seal off an unidentified dural tear in particular case of drainage of intracranial hemorrhage is needed.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.419-430
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• 2012

Due to the calculation difficulty on the hydraulic and hydrologic analysis for road drainage facilities design, these analysis techniques are not applicable. This study's result are development of minutely rainfall-intensity equation suitable for road drainage area, verification of rainfall-runoff model joining kinematic wave theory for road drainage area, computational model based GUI for road surface drainage facilities spacing and culvert's size decision and various road drainage channel design. Applicable test on the developed model is proceed, result that in case of road surface dranage facilities spacing is narrower 6~65% than present spacing calculation method, in other case of road cross dranage facilities size is bigger 6~140% than present size decision method.

• Journal of Yeungnam Medical Science
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• v.32 no.1
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• pp.8-12
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• 2015

Background: Enlargement of subdural hematomas is relatively rapid in subacute stage of hematoma with clinical deterioration, which eventually necessitates surgery. The purpose of this study is to investigate the feasibility and safety of burr hole drainage using urokinase for management of patients with subacute subdural hematoma (SASDH). Methods: Nine patients with SASDH were treated by burr hole drainage using urokinase. Under local anesthesia a catheter was inserted into the hematoma through a burr hole. Burr hole drainage was followed by hematoma thrombolysis with instillation of urokinase (10,000 units) every 12 hours. Drainage was discontinued when a significant decrease of hematoma was observed on cranial computed tomography. Results: The patients' median age was 70 years (range, 62-87). The median Glasgow Coma Scale score before surgery was 15 (range, 11-15). Drainage was successfully performed in all patients. All patients had Glasgow Outcome Scale scores of 5 at discharge. There was no surgery-related morbidity or mortality. Conclusion: A burr hole drainage using urokinase could be a safe, feasible and effective minimally invasive method with low morbidity in treatment of selected patients with SASDHs.

• Clinical Endoscopy
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• v.56 no.6
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• pp.795-801
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• 2023

Background/Aims: Endoscopic biliary drainage is the gold standard treatment for cholangitis. The two methods of biliary drainage are endoscopic biliary stenting and nasobiliary drainage. A novel integrated outside biliary stent and nasobiliary drainage catheter system (UMIDAS NB stent; Olympus Medical Systems) was recently developed. In this study, we evaluated the efficacy of this stent in the treatment of cholangitis caused by common bile duct stones or distal bile duct strictures. Methods: We conducted a retrospective pilot study by examining the medical records of patients who required endoscopic biliary drainage for cholangitis due to common bile duct stones or distal bile duct strictures, and who were treated with a UMIDAS NB stent, between December 2021 and July 2022. Results: Records of 54 consecutive patients were reviewed. Technical and clinical success rates were 47/54 (87.0%) and 52/54 (96.3%), respectively. Adverse events were observed in 12 patients, with six patients experiencing pancreatitis as an adverse event, following endoscopic retrograde cholangiopancreatography (ERCP). Regarding late adverse events, five cases of biliary stent migration into the bile duct were observed. Disease-related death occurred in one patient. Conclusions: The outside-type UMIDAS NB stent is an efficacious new method for biliary drainage and can be applied to many indications.

• Journal of the Korean GEO-environmental Society
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• v.24 no.11
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• pp.25-31
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• 2023

Horizontal drainage, which are representative dewatering method of domestic and foreign slope, are applied to reducing pore water pressure. Accordingly, several previous studies have been conducted, but horizontal drainage are standardized which is an unclean standard for a quantity calculation in filed. Therefore, this study presents field soil and laboratory model box to identify a drainage performance and influencing factors of various horizontal drainage. Furthermore, this study verifies the performance comparison of drainage shape or size according to different particle size distributions. In the outflow results for steady state, the study found that all samples are drained at a constant rate after a minimum of 3 minutes to maximum of 15 minutes. In the case of comparing the outflow per hour (Unit flux) in coarse grained soils, it found that drainage shape and size affect drainage performance. In the result, the future expected to be used basic data that experiment of drainage performance on fine grained soils and determine the quantity.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.669-676
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• 2000

The estimation of consolidation rate is one of the important factors in the construction on soft clayey deposits. A number of researches are carried out to predict the consolidation behavior in field, however, most of the results show the discrepancies between the prediction and observation. This paper analyzes consolidation behavior of normally consolidated clay in K/sub o/ condition with 2-dimensional drainage by use of the numerical methods. Elastic and elastic-plastic finite element analyses are compared in terms of the dissipation of excess pore pressure. These results are also compared with Terzaghi-Rendulic's equation that is implemented by finite difference method. The consolidation time calculated by using elastic model is found to be similar to the result of Terzaghi-Rendulic's equation. The consolidation predicted by MCC model takes more time than other cases. Initial increase of excess pore pressure in radial drainage can be shown, however, this phenomenon does not have a significant effect on tile final consolidation time.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.1
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• pp.48-53
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• 2010

Commercial micro pulps(Arbocel) were coated with three kinds of polymers using spray method. These coated micro pulps were used to papermaking additives to evaluate retention, drainage and physical properties of paper. The retention and drainage were improved with addition of polymer coated micro pulp. The bulk index of paper was also increased, but tensile and tear strength were decreased slightly, probably due to weakening of internal bonding. These results showed that the use of polymer coated micro pulp was an effective method to improve retention, drainage and bulk index of paper.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.373-375
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• 2003

The subway, a typical electrified transit, is operated by the 1500 V DC-powered system with the overhead positive feeder and the rails negative return. This return path would bring about considerable stray current circuits, that is, from the bottom of rails to sell and then to the station ground, unless the rail-to-soil resistance is sufficiently high. The stray current can cause electrolytic corrosion of subway metallic structures and adjacent underground utilities. In this paper, we reports on-site investigation of the stray current condition, especially influenced by drainage method. The drainage method including both forced drainage and polarized drainage, extensively adopted as a countermeasure for electrolytic corrosion of underground pipelines, was found out to exert a harmful influence upon rail components as well as the pipelines.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.125-131
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• 2011

This research aims to investigate the cause of the occurrence of a weak road drainage section scientifically and specifically through a site survey for a poorly drained section occurring due to rainfalls during road operation. This paper deeply reviewed the existing research results and current situation data on the poorly drained sections accumulated in Korea Expressway Corporation in order to investigate the cause of the occurrence of a weak road drainage section, and deeply verified and analyzed the weak sections for the road surface drainage facilities and the other road drainage facilities by visiting the expressway controlled by the 6 local headquarters and 33 branches of Korea Expressway Corporation. As a result of site surveys for the weak road drainage sections, i) in a road surface section, occurrence of ponding in the road shoulder pavement due to slope changes, bad collection of water in the collecting well at a median strip, shortage of road shoulder dike height, and inferior construction, etc. was analyzed to be the main cause of the occurrence of poorly drained sections, and ii) in a road neighborhood section, the occurrence of pavement height difference in a main road and shoulder section due to inferior ditches on a slope and the bad drain age at the inlet and outlet of a culvert due to soil deposits, debris, etc. were analyzed to be the main cause of the occurrence of weak sections. Proposed as a plan to improve the poorly drainage section of road were i)calculation of capacity through material changes at the ditch, enhancement of vertical sections and hydraulic analysis in terms of construction and other aspects, ii)derivation of a combined slope considering a slope and a vertical linearity and maintenance of proper distance between drainage structures in a vertical concave section in terms of geometrical structure, and iii)calculation of the drainage facility installation interval using a minutely rainfall intensity formula and a non-uniform flow analysis technique in terms of hydraulics and hydrologics and prompt removal of rainfalls from the road surface according to a linear drainage method.

• Geomechanics and Engineering
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• v.24 no.5
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• pp.479-490
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• 2021

Pre-drainage of groundwater in the roof aquifer by boreholes is the main method for prevention of roof water disaster, and the drop in the water level during the drainage leads to the variation of the local stress in the overlying strata. Based on a multitude of boreholes for groundwater drainage from aquifer above the 1303 mining face of Longyun Coal Mine, theoretical analysis and numerical simulation are used to investigate the local stress variation in the process of borehole drainage. The results show that due to the drop in the water level of the roof aquifer during the drainage, the stress around the borehole gradually evolved. From the center of the borehole to the outside, a stress-relaxed zone, a stress-elevated zone, and a stress-recovered zone are sequentially formed. Along with the expansion of drainage influence, the stress peak in the stress-elevated zone also moves to the outside. When the radius of influence develops to the maximum, the stress peak position no longer moves outward. When the coal mining face advances to the drainage influence range, the abutment pressure in front of the mining face is superimposed with the high local stress around the borehole, which increases the risk of stress concentration. The present study provides a reference for the stress concentration caused by borehole drainage, which can be potentially utilized in the optimal arrangement of drainage boreholes in underground mining.