• Journal of Chest Surgery
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• v.23 no.3
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• pp.572-576
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• 1990

A complete transection of left main bronchus was repaired by end to end anastomosis 5 months after the chest trauma in the Yeungnam University Hospital. The patient was a 36 years old male who had been injured bluntly by a heavy package on the left chest. The initial symptoms and signs were dyspnea, chest pain and subcutaneous emphysema on the left neck, but on admission at our hospital his chief complaint was only mild left chest discomfort. The preoperative chest X-ray findings 5 months after the trauma revealed total collapse of the left lung, deviation of trachea to the left, elevation of left diaphragm, abrupt discontinuation in the course of an air-filled left main bronchus and bronchoscopy showed that the left main bronchus was completely occluded, without any signs of inflammation, approximately 4 cm from the carina. The operation was performed through standard posterolateral thoracotomy incision at the fifth intercostal space. There was not any suppuration within the transected lung but plenty of white mucus which was removed by forceful suction. The transected bronchial edges were debrided and anastomosed primarily by end to end with interrupted nonabsorbable sutures. The suture line was reinforced with a pleural flap. The postoperative course was uneventful and pulmonary function following operation improved progressively and proved the delayed repair to have a reasonable decision.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.371-388
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• 2023

A stratum with a complex composition and a distributed low-permeability soil layer is difficult to remediate quickly because the soil remediation does not proceed easily. For efficient purification, the permeability should be improved and the soil remediation agent (H₂O₂) should be injected into the contaminated section to make sufficient contact with the TPH (Total petroleum hydrocarbons). This study analyzed a method for crack formation and effective delivery of the soil remediation agent based on pneumatic fracturing, plasma blasting, and vacuum suction (the PPV method) and compared its improvement effect relative to chemical oxidation. A demonstration test confirmed the effective delivery of the soil remediation agent to a site contaminated with TPH. The injection amount and injection time were monitored to calculate the delivery characteristics and the range of influence, and electrical resistivity surveying qualitatively confirmed changes in the underground environment. Permeability tests also evaluated and compared the permeability changes for each method. The amount of soil remediation agent injected was increased by about 4.74 to 7.48 times in the experimental group (PPV method) compared with the control group (chemical oxidation); the PPV method allowed injection rates per unit time (L/min) about 5.00 to 7.54 times quicker than the control method. Electrical resistivity measurements assessed that in the PPV method, the diffusion of H₂O₂2 and other fluids to the surface soil layer reduced the low resistivity change ratio: the horizontal change ratio between the injection well and the extraction well decreased the resistivity by about 1.12 to 2.38 times. Quantitative evaluation of hydraulic conductivity at the end of the test found that the control group had 21.1% of the original hydraulic conductivity and the experimental group retained 81.3% of the initial value, close to the initial permeability coefficient. Calculated radii of influence based on the survey results showed that the results of the PPV method were improved by 220% on average compared with those of the control group.

• Journal of the Korean Geotechnical Society
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• v.30 no.1
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• pp.37-47
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• 2014

Unsaturated hydraulic conductivity (HC) is integrated theoretically from soil water retention curves (SWRC) by Mualem capillary model, but the prediction of HC is extremely sensitive to small variation of matric suction near saturation. Near saturation, the Mualem HC based on smooth SWRC decreases abruptly and has problems in the reliability of hydraulic behavior and the stability of numerical solutions. To improve van Genuchten-Mualem (VGM) HC, the van Genuchten SWRC model is modified within range of low matric suction (arbitrary air entry pressure). At an arbitrary air entry pressure, the VG SWRC is linearized in log scale until full saturation. The modified VG SWRC does not affect the fit of actual retention behavior and either the parameters of original VG SWRC fit. Using the modified VG SWRC, the VGM HC is modified to integrate for each interval decomposed by arbitrary air entry pressure. An analytical solution on modified VGM HC is proposed each interval, to protect the rapid change in HC near saturation. For silty soils, VGM models of HC function underestimate the unsaturated permeability characteristics and especially show rapid reduction near saturation. The modified VGM model predicts more accurate HC functions for Korean weathered soils. Furthermore, near saturation, the saturated HC is conserved by the modified VGM model. After 2-D infiltration analysis of an actual slope, the hydraulic behaviors are compared for VGM and the modified models. The prediction by the proposed model conserved the convergence of solutions on various rainfall conditions. However, the solution by VGM model did not converge since the conductivity near saturation reduced abruptly for heavy rainfall condition. Using VGM model, the factor of safety is overestimated in both initial and final stage during heavy rainfall. Stability analysis based on infiltration analysis could simulate the actual slope failure by the proposed model on HC.

• Journal of the Korean Geotechnical Society
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• v.31 no.8
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• pp.17-28
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• 2015

The purpose of this study is to measure the volumetric water content of unsaturated soils during drying and wetting process by using volumetric pressure plate extractor (VPPE) incorporated with time domain reflectometry (TDR). The VPPE consists of a pressure cell, a pressure regulator, a burette system and a TDR probe. Two samples with different initial void ratios were prepared in the pressure cell, and the air pressure at the range of 0.1 kPa - 50 kPa was applied to adjust the matric suction by the pressure regulator. The burette system was used to measure the volumetric water content change of the sample according to the matric suction. In addition, the TDR probe, installed in the cell, was used to evaluate the dielectric constant from the reflected signal of the electromagnetic wave at the probe. The volumetric water content of specimen was estimated by the empirical equation between the volumetric water content and dielectric constant, which was calibrated with the Jumunjin sand. The test results show that the volumetric water content calculated by TDR probe is strongly correlated to the measured value by burette system. The hysteresis occurs during drying and wetting process. Furthermore, the degree of hysteresis reduces in the repeated process. This study suggests that TDR may be effectively used to evaluate the water content soil for the determination of water characteristic curve of unsaturated soils.

• Horticultural Science & Technology
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• v.17 no.4
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• pp.485-488
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• 1999

This study was conducted to obtain a basic information on the structural and histological characteristics of Gerbera hybrida Hort. leaf injured by american serpentine leafminer (ASL), Liriomyza trifolii, by using light and scanning electron microscope (SEM). Based on the anatomical observation of leaf blade injured by L. trifolii, the injury process could be divided into three stages. In the initial stage, the punctured tiny holes where ASL layed eggs after suction in the upperside of leaf were observed in the palisade parenchyma. In the middle stage, the hatched larvae made mines in the palisade parenchyma only. In the final stage, the mature larvae grew up making the mines bigger, and just before going out from the epidermis, it injured the inside of leaf containing one layer palisade parenchyma and two layers of spongy parenchyma.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1113-1120
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• 2000

Objectives : Despite advance in the surgical treatment of the intracranial aneurysm, we have to be surgical complication. The aim of this report is to evaluate the complication and its management in intracranial aneurysm operation. Methods : We reviewed our exprience with interesting cases of surgical complication of intracranial aneurysm : 1) rebleeding, 2) intra-operative premature rupture, 3) missed aneurysm in angiography, 4) vasospasm. Results : The risk of rebleeding was not related to the patients' initial comdition, but all other intracranial complications occurred significantly more often in patients graded poor compared with patients in good clinical condition. Rebleeding before early surgery remains as major cause of unfavorable outcome. The causes of intraoperative premature ruptures were as follows : 1) dural opening and arachnoid opening(8.3%), 2) hematoma removal(12.5%), 3) brain retraction(16.7%) 4) aneurysm dissection(62.5%). The double suction technique and primary hemostasis using a small piece of cotton or temporary clip resulted in good outcome even in cases with premature rupture. The incidence of missed aneurysm in angiography occurred in 10%. The causes were as thrombosed aneurysm, vasospasm on feeder artery. The most common missed aneurysm is also the most common aneurysm(anterior communicating artery aneurysm). The repeated angiography were documented in missed aneurysm. Balloon angioplasty is superior topapaverine for treatment of proximal vessel vasospasm by viture of a more sustained effect on the vessel. Papaverine can be useful as an adjunct to ballon angioplasty and also for the treatment of distal vessels that are not accessible for ballon angioplasty. Conclusion : The minimization of the complications and active treatment can reduced the mortality and morbidity of ruptured aneurysm patients.

• Tuberculosis and Respiratory Diseases
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• v.67 no.1
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• pp.59-62
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• 2009

Reexpansion pulmonary edema is not a common phenomenon after chest tube insertion but some reports from 0% to 14%. There are various resulting complications, including acute respiratory distress syndrome. We report a case of focal reexpansion pulmonary edema after chest tube insertion. A 49-year-old male came to the hospital due to ongoing dyspnea and left chest pain for 3 days. On chest X-ray, the patient had a left pneumothrax. We planned to insert a chest tube for symptom relief. To determine whether or not the chest had expanded as a result of the chest tube insertion, the patient underwent repeated chest X-rays the following day. The patient experienced brief respiratory symptoms upon initial suction; a chest PA showed patchy consolidated infiltration at the inserted site. After 5 days of conservative management, the recovered completely.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.272-276
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• 2005

Candida tropicalis, an osmophilic strain isolated from honeycomb, produced xylitol at a maximal volumetric production rate of 3.5 g $l^{-1}$ $h^{-1}$ from an initial xylose concentration of 200 g $l^{-1}$. Even with a very high xylose concentration, e.g., 350 g $l^{-1}$, this strain produced xylitol at a moderate rate of 2.07 g $l^{-1}$ $h^{-1}$. In a fed-batch fermentation of xylose and glucose, 260 g $l^{-1}$ of xylose was added, and xylitol production was 234 g $l^{-1}$ for 48 h, corresponding to a rate of 4.88 g $l^{-1}$ $h^{-1}$. To increase the xylitol production rate, cells were recycled in a submerged membrane bioreactor with suction pressure and air sparging. In cell-recycle fermentation, the average concentration of xylitol produced per recycle round, total fermentation time, volumetric production rate, and product yield for ten rounds were 180 g $l^{-1}$, 195 h, 8.5 g $l^{-1}$ $h^{-1}$, and 85%, respectively. When cell-recycle fermentation was started with the cell mass contratrated two-fold after batch fermentation and was performed for ten recycle rounds, we achieved a very high production rate of 12 g $l^{-1}$ $h^{-1}$. The production rate and total amount of xylitol produced in cell-recycle fermentation were 3.4 and 11 times higher than in batch fermentation, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.653-660
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• 2015

In this study, we conduct power performance and load analyses of two different types of vertical-axis tidal-current turbines using the computational fluid dynamics (CFD) method. To analyze the power output and loads, we perform transient CFD simulations considering the cavitation model using ANSYS CFX. The averaged power output of an H-type rotor was 7.47 kW and 67.6 kW in normal and extreme operating conditions, respectively, which did not satisfy the initial design conditions. However, in the case of the helical-type rotor, the power output under normal and extreme conditions were close to the expected values. The cavitation, which may cause instantaneous power fluctuation, occurred repeatedly at the suction side of the rotors. In order to guarantee a more stable power supply and to prevent fatigue failure, we require a design that minimizes cavitation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.140-147
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• 2011

The injection nozzle of an electro-hydraulic injector for the common rail Diesel fuel injection system is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the slenoid actuator was considered as a prime movers in high pressure Diesel injector. Namely a solenoid-driven Diesel injector with different driving current types, as a general method driven by solenoid coil energy, has been applied with a purpose to develop the analysis model of the solenoid actuator to predict the dynamics characteristics of the hydraulic component (injector) by using the AMESim code. Aimed at simulating the hydraulic behavior of the solenoid-driven injector, the circuit model has been developed as a unified approach to mechanical modeling in this study. As this analytic results, we know the suction force and first order time lag for driving force can be endowed in solenoid-driven injector in controlling the injection rate. Also it can predict that the input current wave exerted on solenoid coil is the dominant factor which affects on the initial needle behavior of solenoid-driven injector than the hydraulic force generated by the constant injection pressure.