• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.53-62
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• 2005

The purpose of this study is to improve the seismic behavior of the bracing members. Lee and Goel's (1987) concrete filling in the hollow structural section (HSS) reduced the severity of local buckling and increased the fracture life. However, concrete filling in the HSS did not prevent the occurrence of local buckling in the midsection of the bracing member, which resulted in continuous strength degradation. This study investigated the seismic behavior of the concrete-filled HSS bracing member, which is reinforced by ribs in the midsection of the bracing member. The main variable of the specimens is rib length. The test results showed that buckling mode, cyclic compression strength, and energy dissipation capacity of the bracing members were affected by rib length. Specimen reinforced with ribs with a length of 63% had better structural performance.

• Journal of Veterinary Clinics
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• v.37 no.3
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• pp.157-162
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• 2020

A 6-year-old Thoroughbred mare presented to the Korea Racing Authority Equine Hospital with dropping of the left front fetlock due to an injury sustained while racing. Radiographic examination revealed a comminuted fracture of both proximal sesamoid bones of the affected fetlock. Arthrodesis of the fetlock joint using a broad dynamic compression plate with a tension band wire was performed as a salvage procedure for the future use as a broodmare. After surgery, however, a delayed union of the bones and surgical site infection was present for a prolonged period. Staphylococcus aureus was persistently identified from the surgical site, and antimicrobial therapies were based on antibiotic sensitivity tests, including regional perfusions. The removal and replacement of surgical implants associated with seropurulent discharge was based on coordinating the development of fetlock ankylosis and infection control over 13 months. Firstly, seven screws associated with surgical drainage were replaced and bone morphogenetic protein-2 (BMP-2) and local antibiotics were placed into the surgical site to accelerate bone fusion at postoperative month 7. Further six screws, along with drainage, were removed at postoperative month 10. The plate and screws were removed from the limb due to the progression of bone fusion at postoperative month 13; BMP-2 and local antibiotics were also used. Delayed healing of arthrodesis due to surgical site infection and implant instability were treated by implant removals and antibiotic therapies, and the horse eventually showed improved weight-bearing ability of the affected limb.

• Tuberculosis and Respiratory Diseases
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• v.63 no.4
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• pp.372-377
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• 2007

Tuberculous spondylitis is the most common manifestation of musculoskeletal tuberculosis (TB). The progression of the disease is usually slow and insidious. The main symptom, back pain, is not specific, which frequently results in a delayed diagnosis resulting in neurologic deficits and more advanced vertebral destruction. It is more difficult to diagnose the disease if the involved area is an uncommon sites, such as the upper thoracic, cervical or sacral region. It is important to make an early diagnosis and treatment to achieve a better treatment outcome. We reported a 29 year old female with upper thoracic TB spondylitis(T2-8) and pulmonary TB complaining of back pain that persisted for 5 months and fever. TB spondylitis was not suspected to be due to upper thoracic involvement despite her pulmonary tuberculosis. Chest CT for the evaluation of pulmonary TB found T5 destruction and the paravertebral abscess that was consistent with TB spondylitis. Her spine was examined by MRI, which made an early diagnosis before the neurologic deficit had developed. She was treated with surgical intervention due to the spinal instability and anti-TB medication for 1 year with excellent results.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.12-19
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• 2006

It is positively necessary to study on the stiffness of a 13degree-type impact tester in order to improve the fracture prediction of impact testing in wheels using FE(finite-element) analysis. The 13degree-type impact tester consists of an impact striker, a wheel fixer, a steel plate, and four cylindrical rubbers. Important parts of the tester are the steel plate and four cylindrical rubbers which play a role of absorbing impact energy during impact testing. Because of these buffers, the RF(reaction force) variation of the lower part in the 13degree-type impact tester showed the tendency like a damped harmony oscillation during impact testing. In order to investigate the stiffness of a 13degree-type impact tester, this work measured each stiffness of a steel plate and cylindrical rubbers. The stiffness of a cylindrical rubber was measured using a compressive tester. On the other hand, the stiffness of a steel plate was predicted by simulating experimental method using FE analysis.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.626-639
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• 2003

Statement of problem : Recently, in attempts to reinforce the acrylic resin and to reduce the polymerization shrinkage, it has been reported that adding vinyloligo-silsesquioxane (vinyl-POSS) to PMMA significantly compensates for polymerization shrinkage and somewhat increases the fracture resistance. Purpose : There haven't been any studies on abrasion that can affect the adaptation of the denture in long-term use. In this study abrasion resistance was compared between acrylic resin with vinyl-POSS and commercialized acrylic resin for denture base. In addition, the difference in abrasion resistance according to molding methods was compared. Material and method : Using PaladentR 20 including vinyl-POSS. PaladentR 20, Lucitone 199R, SR IvocapR, denture bases were fabricated using compression molding technique and continuous-pressure injection technique. Surface hardness and abrasion were measured for each group, and the worn surfaces were observed under a scanning electron microscope. Results : 1. When surface hardness was measured for each material and molding technique, there was no statistically significant difference among the materials. (p<0.05) 2. When same denture base material and molding technique were used, the abrasion due to toothpaste solution was 5 times as severe as the abrasion due to soap solution. 3, When toothpaste solution was used, the abrasion decreased in the order of PaladentR20, PaladentR 20 including vinyl-POSS, SR IvocapR, and Lucitone 199R. However statistically significant difference was seen only among PaladentR 20, SR IvocapR, and Lucitone 199R. (p<0.05). 4. When soap solution was used, the abrasion was more severe in PaladentR 20 and including vinyl-POSS PaladentR 20 groups than in SR IvocapR and Lucitone 199R groups. (p<0.05). Conclusion : Addition of vinyl-POSS doesn't improve the abrasion resistance, and the abrasion resistance was similar to those of existing materials. Additional studies under different conditions are needed. For clinical application of vinyl-POSS, further investigations with different requirements and conditions are necessary.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.432-436
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• 2017

Carbon blocks were prepared by compression molding process using the mixture of isotropic cokes and binder pitches, which were reformed with different ${\beta}$-resin contents from pyrolysis fuel oil. Physical and chemical properties and also thermal behavior of binder pitches were investigated through elemental analysis, FT-IR and thermogravimetric analysis, respectively. The adhesion of binder pitches to isotropic coke particles was evaluated from SEM images of the fracture surface of carbon blocks. From these results, it is shown that the adhesion between the cokes and binder was enhanced by increasing the ${\beta}$-resin content of binder pitches. The density of the carbon block after carbonization also increased from 1.325 to $1.383g/cm^3$ by increasing the ${\beta}$-resin content of binder pitches from 1.4 to 20.1%.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.407-411
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• 1996

Stereotactic radiofrequency dorsal root ganglionotomy can be very useful procedures for the treatment of pain emanating from the lumbar segmental nerves. This procedure is reserved for patients who have failed conservative interventional treatments and in whom open surgical intervention is not an option. The advantages of the radiofrequency lesion method are presented, excellent control of the lesion process using temperature monitoring to quantify the lesion size, prevent boiling, and to produce differential destruction of neural tissue. The afferent fibers in the ventral root which are spared by dorsal rhizotomy but nerve fibers with their cells in the ganglion from either dorsal or ventral root can be destructed with stereotactic radiofrequency ganglionotomy. This technique is performed using a 100 mm cannula with a 5 mm active tip. Repeated lateral fluoroscopic view should be taken to make sure that cannlua still resides within the superior, dorsal quadrant or the foramen. With the cannula in this position, electrostimulation is performed and good paresthesia on the leg should be noted with 0.3 and 0.5 volt at 50 Hz stimulation. At 2Hz stimulation distinct dissociation between motor and sensory should be shown. Percutaneous lumbar ganglionotomy have carried out under local anesthesia on inpatient basis in 6 patients. A series of 5 patients with metastatic cancer pain and a patient with compression fracture have been relieved of pain without serious complications.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.4
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• pp.69-79
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• 1992

To estimate soil behavior and structural characteristics under the conditions of cyclic loading, freezing & thawing and initial state, several testing was performed and obtained following results. 1.After repeated freezing and thawing processes, original soil structure was destroyed and changed to globular structure from honeycomb or tube in its structure types. Also above processes resulted increasing the soil compression strain while decreasing the failure stress in stress-strain relationship and reached the soil structure into the mode of brittle fracture. Under cyclic loading conditions, soil cluster which was originally dispersed structure colloided with each other, seperated, and finally the soil failed due to the effect of overcompaction. 2.Through the stabilization processes seperated by four steps, the structure of soil skeleton was changed to quite different globular type. The degree of compressibility of soil was decreased in the normally consolidated zone, while the strength against external load increased due to soil particle stabilization. 3.Soil stress-strain chracteristics were largely influenced by repeated up and down processes of temperature. The maximum deformation was obtained in the case of temperature between 0 10˚C by the reseon of particle cluster reformation. 4.Soil compressibility was largely influenced by the optimum moisture content. Under freezing process, swelling could be found and its magnitude was proportional to the density of soil. 5.Density of soil was decreased as increasing the number or repeated freezing and thawing processes and the largest decreasing rate was found at the first turning point from freezing to thawing cycle.

• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.187-192
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• 2005

Objective: Spinal myeloma has been treated with radiation therapy and chemotherapy. However, the role of surgery was not fully evaluated. This study is performed to evaluate the efficacy of surgery in the treatment of spinal myeloma. Methods: 22 patients who were treated with surgery for spinal myeloma from August 1999 to April 2003 were analyzed. Radiological finding, surgical methods and result were reviewed in retrospective study. For compression fracture due to myeloma infiltration, percutaneous vertebroplasy(PVP) was done. Decompression surgery with or without fixation was performed for patients with neurologic deficit. The modalities of surgery consist of PVP (14 cases), corpectomy and fixation (7 cases), and laminectomy and epidural mass removal (3 cases). To evaluate clinical outcome, visual analogue pain score and Frankel neurological scale were used. Results: In 14 cases of PVP, total 57 vertebral segments were treated including 21 thoracic vertebral bodies and 36 lumbar vertebral bodies. Pain relief was achieved in all cases. The pain score changed from 7.7 (preoperatively) to 2.5 (postoperatively). And pain relief effect was maintained over than one year. Frankel grade improved in decompression cases. Conclusion: Surgical treatment can alleviate pain and improve neurologic deficit immediately in spinal myeloma patients.

• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.711-723
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• 2012

Structural tests were performed to investigate the structural performance of concrete-filled steel tube column using different strength steels in their flange and web with high-strength steel HSA800 and mild steel SM490, respectively. The test parameters included the strength of column flange and infill concrete, and effect of concrete infill. Connection between different grade steels were welded using the electrode appropriate for mild steel and verified its performance. To evaluate the behavior of test specimens, eccentric loading tests were performed and the results were compared with the prediction by current design codes. Axial load and moment carrying capacity of test specimens increased with the yield strength of compression flange and weld fracture occurred after the specimen shows full strength. The prediction result for axial load-bending moment relationship and effective flexural stiffness gave good agreement with the test result.