• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.33-44
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• 2013

Although many studies have been performed for the structural details of orthotropic steel deck, most of them were focused on the trough rib of standard type, but not for orthotropic steel deck with longitudinal rib of open section used at beginning of the deck. In order to investigate the cause of fatigue crack for orthotropic steel deck bridge serviced 31 years with longitudinal rib of open section, in this study, the behavior characteristics of target structural details were analyzed based on measurement data under real traffic condition. Also the typical loading truck passing the target bridges was estimated with the structural analysis detailed, and the stresses and deformation patterns of target structural details were analyzed by performing the detailed structural analysis. Based upon the analysis, retrofitting methods of the fatigue crack were suggested and its validation was examined. From this study, it was clarified that fatigue crack of longitudinal rib with open section were affected with the stress increment by shear deformation in the rib and the occurrence of alternative stress due to moving vehicle. In addition, it was known that it is important to perform fatigue design reflected the local behavior of the structural details.

• Journal of Korean Society of Steel Construction
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• v.17 no.5 s.78
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• pp.593-604
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• 2005

In this paper, the parametric study on the local displacement and the local moment due to a concentrated load is performed for stiffened plates with open ribs and the orthotropic rigidity ratio of stiffened plates is selected as the parameter. For estimating the local behavior, stiffened plates loaded on the center of plates between the ribs were considered and for the global behavior, stiffened plates loaded on the rib at the center of plates were analyzed. The Analyzed results for the local behavior of stiffened plates show that the increasing ratio of the local moment according to rib sizes is constant regardless of rib spaces and the ratio of the local displacement to the global displacement can be expressed as a function of the rib space and the rigidity ratio. The application of functions to examples shows good accuracy in comparison with the local behavior of stiffened plates loaded on the center of plates and the application to the orthotropic analysis of stiffened plates improves accuracy. Therefore, using functions proposed in this study, the local behavior can easily be estimated from the global behavior of stiffened plates with open ribs.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.109-115
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• 2017

Using the computational fluid dynamics (CFD) technique, we performed a numerical simulation in anodesupported solid oxide fuel cell (SOFC). The effect of gas channel/rib width on the cell performance and temperature uniformity was investigated in planar type SOFC. The open source CFD toolbox, OpenFOAM, was used as a numerical analysis tool. As a result, the effect of gas channel/rib width on the cell performance and temperature uniformity was not significant if the oxygen depletion is not occurring. On the other hand, the usage of a wide rib and operation at high current density may lead to performance degradation due to oxygen depletion.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.120-125
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• 2023

Background: Multiple rib fractures are common in blunt chest trauma. Until recently, most surgical rib fixations for multiple rib fractures were performed via open thoracotomy. However, due to the invasive nature of tissue dissection and the resulting large wound, an alternative endoscopic approach has emerged that minimizes the postoperative complications caused by the manipulation of injured tissue and lung during an open thoracotomy. Methods: Our study concentrated on patients with multiple rib fractures who underwent surgical stabilization of rib fractures (SSRF) between June 2018 and May 2020. We found 27 patients who underwent SSRF using video-assisted thoracoscopic surgery. The study design was a retrospective review of the patients' charts and surgical records. Results: No intraoperative events or procedure-related deaths occurred. Implant-related irritation occurred in 4 patients, and 1 death resulted from concomitant trauma. The average hospital stay was 30.2±20.1 days, and ventilators were used for 12 of the 22 patients admitted to the intensive care unit. None of the patients experienced major pulmonary complications such as pneumonia or acute respiratory distress syndrome. Conclusion: Minimally invasive rib stabilization surgery with the assistance of a thoracoscope is expected to become more widely used in patients with multiple rib fractures. This method will also assist patients in a quick recovery.

• Journal of Korea Water Resources Association
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• v.46 no.9
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• pp.947-956
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• 2013

Most of flood protection walls built on the impingement in mountain rivers have been made of concrete. It may cause flood disasters because the smooth wall surface could increase flow velocity. In this study the hydraulic experiments was carried out to evaluate the effect of one side wall with rectangular vertical ribs on flow resistance in open channel. The ratio of the pitch between vertical ribs to its depth, ${\lambda}_{nv}$, was designed so that it include the so-called d type and k type roughness. The range of Froude number, $F_r$, based on hydraulic radius is 0.81~1.12. Flow resistance in the open channel with a rib sidewall depends on the interval length of each ribs and the flow discharge. Maximum flow resistance occurred when ${\lambda}_{nv}$ is 9. In the d type roughness which ${\lambda}_{nv}$ is less than 3, the flow resistance decreases with increase of flow discharge. In the k type roughness which ${\lambda}_{nv}$ is greater than 3, the flow resistance increases with increase of flow discharge. The increments of flow resistance are especially great when ${\lambda}_{nv}$ are 9 and 12. The resistance due to vertical rib is mostly by the shape resistance and the vertical rib on one sidewall of open channel affects on the flow resistance so that the equivalent roughness heights of vertical rib may occur in scale of flow depth. Therefore the vertical ribs may be used to reduce the flow velocity and to move the location of maximum flow velocity from the rib sidewall to the centerward in a cross section of channels.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.411-417
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• 1979

During the period of 4 years from August 1, 1975 to August 1, 1979, authors have experienced 100 cases of multiple rib fractures by nonpenetrating injury at Department of Thoracic Surgery, Paik Foundation Hospital in Seoul, Korea. 1. The ratio of male to female patients with multiple rib fracture was 2.6:1 with male predominance and 84% of the total cases were between 20 and 50 years of age. 2. The most common cause of multiple rib fracture was traffic accident and falls accounted for the next largest group. 3. The most common site of rib fracture was 4th rib to 7th rib level on both hemithorax [52%]. 4. Associated injuries were cerebral contusion in 26%, clavicular fracture in 22%, long bone fracture in 22%, pelvic bone fracture in 10%, and scapular fracture in 8%. 5. Early complications and/or result of the multiple rib fractures were lung contusion in 23 cases, subcutaneous emphysema in 21 cases, hemothorax in 21 cases, hemopneumothorax in 6 cases, and flail chest in 12 cases. 6. The flail chests were managed by strapping the chest with adhesive plaster, external traction of flail segment with towel clip, ventilatory assistance for marginal clinical indications, and in cases of complicated with intrathoracic hemorrhage, wire fixation of flail segment through open thoraco-tomy. 7. The principles of therapy for hemothorax and/or pneumothorax were rapid reexpansion of the lungs by thoracentesis [11%] and closed thoracostomy [22%], but open thoracotomy had to be done on 3 cases because of massive bleeding or intrapleural hematoma and diaphragmatic rupture. 8. The over all mortality was 4% [4 among 100 cases] and the cause of all deaths was head injury.

• Steel and Composite Structures
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• v.42 no.6
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• pp.843-853
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• 2022

The fatigue behavior of welded open rib-to crossbeam joints (ORCJ) in orthotropic bridge structures is investigated using a traction structural stress method. The fatigue behaviors of welded open rib-to crossbeam joints have been a subject of study for decades for ensuring operational safety and future design improvement. A mesh-insensitive combination of traction structural stresses in ORCJ was obtained considering the effect of in-plane shear stress and validated by fatigue test results. The proposed method is advantageous for predicting fatigue cracks that initiate from the crossbeam cutout and propagate along the crossbeam. The investigations carried out with the proposed approach reveal that the normal structural stress decreases with the propagation of fatigue cracks, while the ratio of shear stress to normal stress increases. The effect of shear structural stress is significant for the analysis of fatigue behavior of ORCJ in multiaxial stress states.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.179-185
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• 2017

Purpose: Rib fracture is the most common complication of blunt thoracic trauma. We investigated the effect of rib fracture on pulmonary function in the conservatively treated patients. Methods: From January 2000 to February 2017, we reviewed the records of 72 patients with rib fracture and pulmonary function tests were performed. According to the number of rib fractures, patients were classified into two groups: less than six fractured ribs (group A) and more than six fractured ribs (group B). The groups were compared concerning demographics, underlying diseases, associated thoracic injuries, surgery, mechanical ventilator times, days spent in the intensive care unit and pulmonary function test. Results: There were no statistically significant differences in the demographic data between the two groups. Mean hospitalization was 13.5 days in group A and 27.0 days in group B (p<0.001). There was no statistically significant difference between the two groups in the pulmonary function test. Conclusions: We conclude that pulmonary function is restored by conservative treatment in patients with rib fractures even if the number of rib fractures increases. In patients with multiple rib fractures, studies comparing open rib fixation and conservative treatment of long term pulmonary function are required.

• Journal of Trauma and Injury
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• v.30 no.2
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• pp.63-65
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• 2017

Standard open procedures for resection of the first rib in thoracic outlet syndrome can prove to be quite difficult with extensive incisions. A minimal invasive procedure can also be painstaking, but provides an attractive alternative to the more radical open procedures. We report the details of the technique with direct video footage of the procedure performed in a 41-year-old man with thoracic outlet syndrome done entirely by thoracoscopic methods.

• Journal of Chest Surgery
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• v.17 no.1
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• pp.110-117
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• 1984

A clinical evaluation was performed on 76 cases of chest injury experienced at department of Chest Surgery, Capital Armed Forces General Hospital during the past 3 years period from January 1981 to August 1983. 1.The most common cause of the chest trauma was gun shot by which 26 cases were injured among 44 cases [57.9%] of penetrating injury. Remaining 32 cases [42.1%] were injured by non-penetrating blunt trauma. 2.Hemopneumothorax was observed in 60 cases [78.9%], those were caused by both penetrating [65%] and non-penetrating [35%] injuries. 3.Rib fracture was found in 58.7% of total cases and with rib fracture, clavicle fracture was combined at 19.6% and sternal fracture, at 8.7%. 4.Most common symptoms were chest pain and dyspnea, and most common signs were breath sound diminution and subcutaneous emphysema. 5.Common site of rib fracture was from 4th rib to 8th rib [69.4%]. 6.In 58 cases [76.3%], patients were treated with operation including open thoracotomy [25 cases]. 7.Overall mortality was 5.3%[4 cases] and causes of death were septic shock and respiratory failure.