• The Korean Journal of Pain
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• v.10 no.1
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• pp.104-108
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• 1997

Spontaneous intracranial hypotension, a syndrome of low CSF pressure, occurs without preceding events such as lumbar puncture, back trauma, operative procedure or medical illness. The most characteristic symptom is an occipital or frontal headache which is aggrevated in the erect position and relieved in the supine position. This syndrome usually resolves spontaneously or with strict bed rest. When the headach persists or is incapacitating, more aggressive treatment may be necessary. Autologous epidural blood patch is highly effective in the management of spontaneous intracranial hypotension. Epidural blood produces an organized clot which effectively tamponade any dural CSF leak. The rapid relief of headache immediately after the infusion of blood occur by some other mechanism, such as an increase in subarachnoid pressure that is known to occur with infusion of fluid into the lumbar epidural space. We report three cases of spontaneous intracranial hypotension successfully treated with epidural blood patch.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.288-290
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• 2010

The common etiologies of pneumocephalus, presence of air in the intracranial cavity, are trauma and cranial surgery. Pneumocephalus after spinal surgery is an unusual postoperative complication. We report the case of a male 59-year-old man who developed a pneumacephalus after posterior lumbar surgery for spinal stenosis. Intraoperatively, a cerebrospinal fluid leak following a dural tear was noted and immediately repaired. The next day, the patient complained of headache and dizziness. Head and lumbar computed tomography scans revealed significant air in the frontal region, several cisterns, intraventricle, and extra-dural area in the spine canal. Symptoms were spontaneously resolved within 2 weeks with conservative management.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1559-1566
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• 1994

Using the finite element method, the contact force, contact band width and temperature distribution of lip seals analyzed for the interference including some nonlinearities such as material nonlinearity, geometrical nonlinearity and nonlinear contact boundary condition. The calculated results showed that the contact stress concentrated on the contact zone between the garter spring and the rubber toward the flex side, the contact edge of lip seals. The high contact forces due to the increased interference separate the sealing gap between the lip edge and the rotating shaft. This may lead to leak the sealed oil.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.322-327
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• 2001

The internal leaks of RCS pressure boundary valves may cause thermal fatigue crack because of the TASCS in RCS branch line. After experienced unisolable piping failures in several PWR plants, many studies have peformed to understand these phenomena and various methods were applied to ensure the structural integrity of piping. In this paper, the cause of unisolable piping failures and the alternatives to prevent recurrence of failure were reviewed. Also, the severity of piping failure including susceptibility of valve leaks was evaluated for the Westinghouse 2-loop plant. The length of turbulent penetration on RHR inlet piping was measured and, thermal fluid analysis and fatigue analysis was performed for this piping. As a means of ensuring the structural integrity, temperature monitoring and specialized UT and other alternatives were compared for the further application.

• Progress in Superconductivity and Cryogenics
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• v.16 no.3
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• pp.15-20
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• 2014

The heavy ion accelerator that will be built in Daejeon, Korea utilizes superconducting cavities operating in 2 K. The cavities are QWR (quarter wave resonator), HWR (half wave resonator), SSR1 (sing spoke resonator1) and SSR2. The main role of the cryomodule is supplying thermal insulation for cryogenic operation of the cavities and maintaining cavities' alignment. Thermal and structural consideration such as thermal load by heat leak and heat generation, cryogenic fluid management, thermal contraction, and so on. This paper describes detailed design considerations and current results have being done including thermal load estimation, cryogenic flow piping, pressure relief system, and so on.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.48-50
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• 2010

Spontaneous intracranial hypotension is often idiopathic. We report on a patient presenting with symptomatic intracranial hypotension and pain radiating to the right leg caused by a transdurallumbar disc herniation. Magnetic resonance (MR) imaging of the brain revealed classic signs of intracranial hypotension, and an additional spinal MR confirmed a lumbar transdural herniated disc as the cause. The patient was treated with a partial hemilaminectomy and discectomy. We were able to find the source of cerebrospinal fluid leak, and packed it with epidural glue and gelfoam. Postoperatively, the patient's headache and log radiating pain resolved and there-was no neurological deficit. Thus, in this case, lumbar disc herniation may have been a cause of spontaneous intracranial hypotension.

• Fire Science and Engineering
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• v.27 no.5
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• pp.19-25
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• 2013

The fire took place in the synthetic heat transfer fluid boiler. This study uses simulation to investigate the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is more or less unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120 kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The simulation shows that the temperature is $767^{\circ}C$ in the low part of the third pass. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. The temperature rises to $183^{\circ}C$ in the low part of the burner. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner.

• Advances in pediatric surgery
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• v.2 no.2
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• pp.143-147
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• 1996

Spontaneous perforation of the bile duct in children is a very rare disorder. We experienced a 6 year-old girl with spontaneous perforation of the right hepatic duct. The patient was initially misdiagnosed as hepatitis because of elevation of liver enzyme and then as appendicitis because of fluid collection in the pelvic cavity demonstrated by ultrasonogram. A laparoscopic exploration was done and no abnormal findings were detected except bile-stained ascites. Peritoneal drainage was performed and the patients seemed to improve clinically. Abdominal pain, distention and high fever developed after removal of the drains. DISIDA scan showed a possible of bile leak into the peritoneal cavity. ERCP demonstrated free spill of dye from the right hepatic duct. At laparotomy, the leak was seen in the anterior wall of the right hepatic duct 2cm above the junction of the cystic duct and common hepatic duct. The perforation was linear in shape and 0.8cm in size. The patient underwent cholecystectomy, primary closure of the perforation and T-tube choedochostomy. We could not identify the cause of the perforation; however, the T-tube cholangiography taken on the 42nd postoperative day showed a little more dilatation of the proximal common bile duct compared with the cholangiography taken on the 14th day. Long-term follow-up of the patient will be necessary because of the possibility for further change of the duct.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.60-64
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• 2015

Objective : To present the incidence and management of dural tears and cerebrospinal fluid leakage during corrective osteotomy [Pedicle Subtraction Osteotomy (PSO) or Smith-Petersen Osteotomy (SPO)] for ankylosing spondylitis with kyphotic deformity. Methods : A retrospective study was performed for ankylosing spondylitis patients with fixed sagittal imbalance, who had undergone corrective osteotomy (PSO or SPO) at lumbar level. 87 patients were included in this study. 55 patients underwent PSO, 32 patients underwent SPO. The mean age of the patients at the time of surgery was 41.7 years (21-70 years). Of the 87 patients, 15 patients had intraoperative dural tears. Results : The overall incidence of dural tears was 17.2%. The incidence of dural tears during PSO was 20.0%, SPO was 12.5%. There was significant difference in the incidence of dural tears based on surgical procedures ( PSO vs. SPO) (p<0.05). The dural tears ranged in size from 12 to $221mm^2$. A nine of 15 patients had the relatively small dural tears, underwent direct repair via watertight closure. The remaining 6 patients had the large dural tears, consequently direct repair was impossible. The large dural tears were repaired with an on-lay graft of muscle, fascia or fat harvested from the adjacent operation site. All patients had a successful repair with no patient requiring reoperation for the cerebrospinal fluid leak. Conclusion : The overall incidence of dural tears during PSO or SPO for ankylosing spondylitis with kyphotic deformity was 17.2%. The risk factor of dural tears was complexity of surgery. All dural tears were repaired primarily using direct suture, muscle, fascia or fat graft.

• Journal of Rhinology
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• v.25 no.2
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• pp.123-129
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• 2018

Background and Objectives: Endoscopic repair of cerebrospinal fluid (CSF) leak can avoid morbidity of open approaches and has shown a favorable success rate. Free mucosal graft is a good method, and multi-layered repair is more favorable. The inferior turbinate has been commonly utilized for the free mucosal graft, but we newly designed it as a bone-periosteal-mucosal composite graft for multilayered reconstruction. Subjects and Method: Four subjects with a skull base defect were treated with this method. The inferior turbinate was partially resected including the conchal bone and was trimmed according to defect size. Both bony parts and periosteum were preserved on the basolateral side of the mucosa as a composite graft. The graft was applied to the defect site using an overlay technique. Results: All cases were successfully repaired without any complications. Three of them had a defect size greater than 10-12 mm, and the graft stably repaired the CSF leakage. Conclusion: Endoscopic repair of CSF leakage using inferior turbinate composite graft is a simple and easy method and would be favorable for defect sizes greater than 10 mm.