• Korean Journal of Materials Research
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• v.2 no.6
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• pp.468-476
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• 1992

Stress rupture properties and fracture behavior of Ni microalloyed W were studied using direct load creep tester at 100$0^{\circ}C$, 110$0^{\circ}C$ and 120$0^{\circ}C$ in $H_2$. At the same grain size, 15${\mu}$m, the 100hr. stress rupture strength of W-0.4wt% Ni was 23% higher than that of W-0.2wt%Ni due to the grain growth during test. The minimum creep rate of W-0.2wt%Ni was decreased with an increase in initial grain size. By increasing the Ni content of Ni microalloyed W, rupture time was increased owing to the smaller number and size of cavity. All the specimens showed intergranular fracture by grain boundary sliding and nucleation, growth and coalescence of cavities at grain boundary.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.28-33
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• 2009

Purpose: This retrospective study was designed to evaluate the treatment results of chronic Achilles tendon rupture by Lindholm method. Materials and Methods: Between 2002 and 2006, we performed the reconstruction of the Achilles tendon by using of the gatrocnemius-sloeus fascia known as Lindholm method. Ten cases of ten patients were enrolled in this study (8 men and 2 women). The mean age of the patients at the time of operation was 49 years (range, 32${\sim}$66 years). The mean follow-up duration was 15.2 months (range, 12${\sim}$19 months). The retrospective review of the clinical history, physical examination, the American Orthopedic Foot and Ankle Society (AOFAS) score were conducted. Results: The mean AOFAS score before surgery was 74.10${\pm}$2.56 and that of the latest follow-up was 90.60${\pm}$5.72. The excellent results were six and good results were four patients. Eight patients were normal triceps power and the others were good. The average of heel to floor distance was 4.5 mm less in the operated legs than the contralateral ones in each patient, but there was no significant difference (p>0.05). The average of calf muscle circumference in the mid-leg was 7.5 mm less in the operated legs than the contralateral ones and there was significant difference (p<0.05). The active range of motion of the ankles, mean plantarflexion was 40 degrees and dorsiflexion was 16.8 degrees in operated side. The contralateral side was 43 degrees in plantarflexion and 19 degrees in dorsiflexion. No case showed rerupture of the reconstructed Achilles tendon. One patient had the superficial wound infection which was treated successfully by antibiotic therapy. Conclusion: It was suggested that the overall results of Lindholm method for the chronic Achilles tendon rupture indicated satisfactory outcomes.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.217-222
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• 2012

Purpose: Diaphragmatic rupture following trauma is often an associated and missed injury. This report is about our experience with treating traumatic diaphragmatic rupture (TDR). Methods: From January 2007 to September 2012, 18 patients who had a diaphragmatic rupture due to blunt trauma or penetrating injury underwent an operation for diaphragmatic rupture at our hospital. We retrospectively reviewed their medical records, including demographic factors, initial vital signs, associated injuries, interval between trauma and diagnosis, injured side of the diaphragm, diagnostic tools, surgical method or approaches, operative time, herniated organs, complications, and mortality. Results: The average age of the patients was 43 years, and 16 patients were male. Causes of trauma included motor vehicle crashes (n=7), falls (n=7), and stab wounds (n=5). The TDR was right-sided in 6 patients and left-sided in 12. The diagnosis was made by using a chest X-ray (n=3), and thorax or upper abdominal computed tomography (n=15). Ten(10) patients were diagnosed within 12 hours. A thoracotomy was performed in 8 patients, a video-assisted thoracoscopic surgery in 4 patients, a laparotomy in 3 patients, and a sternotomy in one patient. Herniated organs were the omentum (n=11), stomach (n=8), spleen and colon (n=6), and liver (n=6). Eighteen diaphragmatic injuries were repaired primarily. Seven patients underwent ventilator care, and two of them had pneumonia and acute respiratory distress syndrome. There were no operative mortalities. Conclusion: Early diagnosis and surgical treatment determine the successful management of TDR with or without the herniation of abdominal organs. The surgical approach to TDR is chosen based on accompanying organ injuries and the injured side.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.420-428
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• 2023

Objective: Intraprocedural rupture (IPR) is a fatal complication of endovascular coiling for cerebral aneurysms. We hypothesized that contrast leakage period may be related to poor clinical outcomes. This study aimed to retrospectively evaluate the relationship between clinical outcomes and contrast leakage period. Methods: Data from patients with cerebral aneurysms treated via endovascular coiling between January 2010 and October 2018 were retrospectively assessed. The enrolled patient's demographic data, the aneurysm related findings, endovascular treatment and IPR related findings, rescue treatment, and clinical outcome were analyzed. Results: In total, 2,859 cerebral aneurysms were treated using endovascular coiling during the study period, with IPR occurring in 18 (0.63 %). IPR occurred during initial frame coiling (n=4), coil packing (n=5), stent deployment (n=7), ballooning (n=1), and microcatheter removal after coiling (n=1). Tear sites included the dome (n=14) and neck (n=4). All IPRs were controlled and treated with coil packing, with or without stenting. Flow arrest of the proximal balloon was not observed. Temporary focal neurological deficits developed in two patients (11.1%). At clinical follow-up, 14 patients were classified as modified Rankin Scale (mRS) 0, three as mRS 2, and one as mRS 4. The mean contrast leakage period of IPR was 11.2 min (range: 1-31 min). Cerebral aneurysms with IPR were divided into late (n=9, mean time: 17.11 min) and early (n=9, mean time: 5.22 min) control groups based on the criteria of 10 min of contrast leakage period. No significant between-group differences regarding clinical outcomes were observed after IPR (p=1). Conclusions: In our series, all patients with IPR were controlled with further coil packing or stenting without proximal balloon occlusion within 31 min of contrast leakage. There was no difference in clinical outcomes when the long contrast leakage period group and short contrast leakage period group were compared.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.474-483
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• 2021

To establish the exclusive role of hydrogen on burst behaviour of Zircaloy-4 during loss-of-coolant accident transients, an extensive single-rod burst tests were conducted on both unirradiated as-received and hydrogenated Zircaloy-4 cladding tubes at different heating rates and internal overpressures. The visual observations of cladding tubes during bursting as well as post-burst are presented in detail to understand the effect of hydrogen concentration, heating rate, and internal pressure. Impact of hydrogen on burst parameters-burst stress, burst strain, burst temperature-during loss-of-coolant accident transients are compared and discussed. Rupture at multiple locations for hydrogenated cladding at lower internal pressure and higher heating rate is reported for the very first time. A novel burst criterion accounting hydrogen concentration in nuclear fuel cladding is proposed.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1307-1313
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• 2019

Recent analysis results with realistic assumptions provide the variability of operator allowable time for the initiation of aggressive cooldown under small break loss of coolant accident or steam generator tube rupture with total failure of high pressure safety injection. We investigated how plant risk may vary depending on the variability of operators' failure probability of timely initiation of aggressive cooldown. Using a probabilistic safety assessment model of a nuclear power plant, we showed that plant risks had a linear relation with the failure probability of aggressive cooldown and could be reduced by up to 10% as aggressive cooldown is more reliably performed. For individual accident management, we found that core damage potential could be gradually reduced by up to 40.49% and 63.84% after a small break loss of coolant accident or a steam generator tube rupture, respectively. Based on the importance of timely initiation of aggressive cooldown by main control room operators within the success criteria, implications for improvement of emergency operating procedures are discussed. We recommend conducting further detailed analyses of aggressive cooldown, commensurate with its importance in reducing risks in nuclear power plants.

• Journal of Chest Surgery
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• v.25 no.3
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• pp.335-340
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• 1992

Truamatic aortic rupture is usually fatal if left untreated. Prompt diagnosis is the cornerstone of suscessful management. But the usual screening tests are non specific and the accuracy of computerized tomography is low, Aortography which is a time consuming procedure may result in false-positive interpretations and significant morbidity. Recently transesophageal echocardiography provides a rapid, effective and relatively safe means of evaluating the distal aortic arch and also affords the opportunity to evaluate the heart during the same study, which may be of benefit in cases of suspected cardiac injury. The experience with the traumatic aortic ruptured patient and a critical review of the literature suggests that transesophageal echocardiography is a useful technique for the diagnosis of ruptured aorta following blunt chest trauma.

• Journal of Surface Science and Engineering
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• v.24 no.1
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• pp.8-8
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• 1991

To investigate the effects of substrate on transverse-rupture strength(TRS) and bonding strength between substrate and TiC layer coated by CVD, two kinds of substrate (substrate A:WC-9.5wt%Co-MC*[low C], substrate B: WC-6wt% Co-MC*[high C] were studied in terms of Cobalt and C contents respectively. For preparation of test samples the coating parameters of deposition time, deposition temperature and deposition pressure were varied. The result show that the carbon contents in substrates have greater effects on the TRS of the CVD TiC coated cemented carbide than Co contents in substrates.

• Journal of Surface Science and Engineering
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• v.25 no.1
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• pp.8-15
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• 1992

To investigate the effects of substrate on transverse-rupture strength(TRS) and bonding strength between substrate and TiC layer coated by CVD, two kinds of substrate (substrate A: WC-9.5wt% Co-MC＊[low C], substrate B: WC -6wt% Co-MC＊[high C]) were studied in terms of Cobalt and C contents respectively. For preparation of test samples the coating parameters of deposition time, deposition temperature and deposition pressure were varied. The results show that the carbon contents in substrates have greater effects on the TRS of the CVD TiC coated cemented carbide than Co contents in substrates. ＊MC:TiC+TaC

• Journal of the Korean Professional Engineers Association
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• v.25 no.4
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• pp.102-108
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• 1992

This study was carried to find out the soil characteristics of landslide site and to develope landslide prediction method by seismic refraction prospecting. For these aims, landslide condition and travel time were investigated at 68 Landslide sites over the country during 1990 to 1991. The results were as follows. 1. The surface of rupture was included mainly in C layer. Its Hardness was less than 3kg / $\textrm{cm}^2$ at the upper pare of landslide. 2. When the profile line length was 20m, the range of travel time was 40 to 90 msec. The travel time did not differ between bedrocks. 3. Refraction distance ranged from 1 to 7m and mean of that was 2.5m. Travel time was increased according to receiving distance without large variance in the refraction distance but that was appeared large variance out of the refraction distance on slope that has shallow soil depth and discontinuous ground surface. Therefore, the spread distance must be shorten to 10-l5m. 4. The seismic velocity at the first layer(layer of rupture) was less than 500m1sec by degree of weathering and the velocity at the second layer decreased in order of Granite> Granitic gneiss >Sedimentary rock. 5. The first layer observed by seismic refraction was contained C layer that has parent material and weathered rocks of hardness 10-20kg/$\textrm{cm}^2$. 6. Among the range of seismic velocity was less than 200m/sec in 63% of the total plots, 200-300m/sec in 34% and 300-500m /sec in 3%. 7. There was a proportional relationship between seismic prospecting soil depth and executive soil depth, and seismic propection soil depth was about 10 to 20cm deeper than the order.