• Archives of Plastic Surgery
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• v.34 no.3
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• pp.358-364
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• 2007

Purpose: A life-threatening hemorrhage resulting from a severe facial fracture is rare, but it needs a prompt and aggressive treatment. Especially, a massive oronasal bleeding combined with midfacial fracture which may result from the rupture of the internal maxillary artery. With the recent advances in the radiologic intervention, its use has increased for managing these life threatening case. We reviewed its usefulness with our experiences and literatures. Methods: A retrospective review was performed to determine the usefulness of the transcatheter arterial embolization in patients with panfacial trauma. If the vital signs were unstable, cardiopulmonary resuscitation was performed. Oronasal bleeding was controlled with nasal packing and electrocautery. All injured regions were studied by radiologic study including CT. Even after primary management, if the oronasal bleeding was persistent, radiologic intervention was performed 10 patients were treated with transcatheter arterial embolization and the bleeding focus controlled by embolization with polyvinyl alcohol and gelfoam. Results: After the intervention, the vital signs became stable and there were no complications from embolization in the follow-up for 6 months. Also patients could recover through appropriate operations. Conclusion: Transcatheter arterial embolization for maxillofacial injury has many advantages for both, the doctor and the patient. First, less pain is induced than a compression device or an operation, which is another way to treat oronasal bleeding. Second, it does not need general anesthesia. And through a single procedure not only we can know the accurate bleeding point, but we can also bleeding by embolization.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.315-322
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• 2008

Valves in power plants are leaking internally by various damages including insertion of foreign objects on seat, seat crack, defects and fatigue crack of stem packing or welds etc. due to severe operating conditions such as high temperature and high pressure for extended period time. Acoustic emission(AE) technology should be applied in order to diagnose precisely and evaluate these valve internal leak. In this paper, results of studies which have accomplished in actual power plant are presented. We have analyzed background noise, AE signal level and frequency spectrum through laboratory tests on the basis of various actual conditions in power plant, and also have considered evaluation methods on the background noise, AE properties and the detectable minimum leak rate according to valve leak conditions through comparing with results of field tests in power plant. As a result of these studies, we conformed that evaluation of internal leak conditions including discrimination of leak or not, and the detectable minimum leak rate is possible, and also it is expected to contribute to safe operation and prevention of energy loss in power plants.

• Journal of Trauma and Injury
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• v.35 no.3
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• pp.215-218
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• 2022

The rectum is the least frequently injured organ in trauma, with an incidence of about 1% to 3% in trauma cases involving civilians. Most rectal injuries are caused by gunshot wounds, blunt force trauma, and stab wounds. A 46-year-old male patient was crushed between two vehicles while he was working. He was hemodynamically unstable, and the Focused Assessment with Sonography for Trauma showed hemoperitoneum and hemoretroperitoneum; therefore, damage control surgery with pelvic packing was performed. A subsequent whole-body computed tomography scan showed a displaced pelvic bone and sacrum fracture. There was evidence of an anorectal full-thickness laceration and urethral laceration. In second-look surgery performed 48 hours later, the pelvis was stabilized with external fixators, and it was decided to proceed with loop sigmoid colostomy. A tractioned rectal probe with an internal balloon was positioned in order to approach the flaps of the rectal wall laceration. On postoperative day 13, a radiological examination with endoluminal contrast injected from the stoma after removal of the balloon was performed and showed no evidence of extraluminal leak. Rectosigmoidoscopy, rectal manometry, anal sphincter electromyography, and trans-stomic transit examinations showed normal findings, indicating that it was appropriate to proceed with the closure of the colostomy. The postoperative course was uneventful. The optimal management for extraperitoneal penetrating rectal injuries continues to evolve. Primary repair with fecal diversion is the mainstay of treatment, and a conservative approach to rectal lacerations with an internal balloon in a rectal probe could provide a possibility for healing with a lower risk of complications.

• Journal of Korean Neurosurgical Society
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• v.50 no.6
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• pp.520-522
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• 2011

Injury to the vertebral artery during anterior cervical discectomy is rare but potentially fatal. We report a case of cerebellar infarction after endovascular embolization for iatrogenic vertebral artery injury at C5-C6 during an anterior cervical discectomy and fusion. A 61-year-old man had an intraoperative injury of the right vertebral artery that occurred during anterior cervical discectomy and fusion at C5-C6. Hemorrhage was not controlled successfully by packing with surgical hemostatic agents. While the patient was still intubated, an emergency angiogram was performed. The patient underwent endovascular occlusion of the right V2 segment with coils. After the procedure, his course was uneventful and he did not show any neurologic deficits. Brain computed tomographic scans taken 3 days after the operation revealed a right cerebellar infarction. Anti-coagulation medication was administered, and at 3-month follow-up examination, he had no neurologic sequelae in spite of the cerebellar infarction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.6
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• pp.364-368
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• 2019

A Le Fort I osteotomy is a common procedure for correcting dental and facial deformities in orthognathic surgery. In rare cases, a delayed hemorrhage can occur as early as several hours or up to 12 weeks, postoperatively. The most frequently involved blood vessels in a delayed hemorrhage are the descending palatine artery, the internal maxillary artery, and the pterygoid venous plexus of veins. Intraoral bleeding accompanied by severe epistaxis in these cases makes it difficult to locate the precise bleeding focus. Eventual uncontrolled bleeding would require Merocel packing or surgical intervention. In general, a severe late postoperative hemorrhage is most effectively managed by angiography and embolization. Herein we describe a delayed hemorrhage case in which the cause was not evident on angiography. We were able to detect the bleeding point through an endoscopic nasal approach and treat it using direct cauterization.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.875-883
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• 2006

The carbon and nitrogen removal process using PVA-gel (Polyvinyl Alcohol) immobilized microorganisms was studied. The process has been operated under diverse process conditions for 12 months. The process consists of denitrification with internal recycle of 300%, nitrification, aerobic digestion reactors and settling tank. Nitrificatoin and nitrogen removal efficiency according to gel packing ratio and temperature were studied. Yield for Heterotrophs ($Y_H$), decay coefficient for Heterotrophs($b_H$) in aerobic digestion reactor were determined to seize sludge reduction mechanism and compared with typical data of activated sludge process. Then SRT in aerobic digestion reactor was determined on an experimental basis and sludge reduction efficiency was calculated. The process was implemented successfully with sludge reduction efficiency of 92.0~98.5% on a basis of biomass.

• Archives of Craniofacial Surgery
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• v.22 no.3
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• pp.168-172
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• 2021

Posttraumatic pseudoaneurysm of the face is caused by blunt, penetrating, or surgical trauma. Although its incidence is low, pseudoaneurysm rupture can cause a life-threatening, massive hemorrhage. A 48-year-old man visited our emergency center due to a fall-down accident. Three-dimensional computed tomography (CT) showed a comminuted zygomaticomaxillary complex fracture of the left face. After open reduction and internal fixation, the surgical wound healed without any complications. However, the patient was readmitted 10 days after surgery due to pus-like discharge from the wound. Contrast-enhanced CT to find the abscess unexpectedly revealed a pseudoaneurysm in the left retromaxillary area. Massive oral bleeding occurred on the night of re-hospitalization and emergency surgery was done. The bleeding site was identified as a pseudo-aneurysmal rupture of the posterior superior alveolar artery in the retromaxillary area. Hemostasis was achieved by packing Vaseline gauze in the maxillary sinus using an endoscope. Delayed rupture and massive bleeding of posttraumatic retromaxillary pseudoaneurysm after a zygomaticomaxillary fracture is a low-probability, but high-impact event. Therefore, additional contrast-enhanced CT should be considered to evaluate the possibility of a posttraumatic pseudoaneurysm in cases of severe comminuted zygomaticomaxillary fracture.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.56-62
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• 2024

By introducing curing kinetics and chemo-rheology for the epoxy resin formulation for ultra-high voltage gas insulated switchgear (GIS) Insulating Spacers, a study was conducted to simulate the curing behavior, flow and warpage analysis for optimization of the molding process in automatic pressure gelation. The curing rate equation and chemo-rheology equation were set as fixed values for various factors and other physical property values, and the APG molding process conditions were entered into the Moldflow software to perform optimization numerical simulations of the three-phase insulating spacer. Changes in curing shrinkage according to pack pressure were observed under the optimized process conditions. As a result, it was confirmed that the residence time in the solid state was shortened due to the lowest curing reaction when the curing holding pressure was 3 bar, and the occurrence of deformation due to internal residual stress was minimized.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5074-5081
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• 2015

A method for improving the warpage of the plastic part is a method of removing residual stress of the plastic product. that a non-uniform cooling are appeared in the injection molding process make uniform cooling. this study was developed the Rapid heating and cooling device used peltier module for uniform cooling. Make the Rapid heating and cooling device(RCHD), for Traditional water cooling device(TWCD) method and the Rapid heating and cooling method warpage were compared and were analyzed and the materials used amorphous ABS polymer. various warpage were compared for the process parameters such as packing pressure, packing time, resin temperature, mold temperature, In the amorphous ABS polymer, TWCD method has higher warpage than RCHD method and show the result to be a bit more uniform cooling. The distribution state of the ABS polymer was confirmed Through the Scanning electron microscope. In the TWCD method the distribution state of the polymer be densely distributed, and RCHS method be distributed wider than TWCD method. this is that injection molded parts be seen that cooling was made uniformly, As the temperature of the mold is gradually progress, Particles of the polymer is increased this is that internal stress was reduced.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.230-238
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• 2023

Small and medium-sized food manufacturing enterprises are largely reliant on manual labor, from inputting raw materials to palletizing the final product. Recently, there has been a trend toward smartness and digitization through the implementation of robotics and sensor data technology. In this study, we examined the effectiveness of improvement through 3D simulation on two repetitive work processes within a food manufacturing company. These processes involve workers whose speed cannot match the capacity of the applied equipment. Two manual processes were selected: the weighing and packing process performed by workers after skewer assembly, and the manual batch process of counting randomly delivered frozen foods, packing (both internal and external), and palletizing. The production volume, utilization rate, and number of workers were chosen as verification indicators. As a result of the simulation for improving the 3D process, production increased by 13.5% and 56.8% compared to the existing process, respectively. This was particularly evident in the process of applying palletizing robots. In both processes, as the utilization rate and number of input workers decreased, robots could replace tasks with high worker fatigue, thereby reducing work overload. This study demonstrates the potential to visually compare the process flow improvement using 3D simulations and confirms the possibility of pre-validation for improvement.