• Journal of Chest Surgery
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• v.41 no.4
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• pp.504-507
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• 2008

Implantable central venous catheters (Chemoport) are increasingly being used for vascular access, parenteral nutrition and administering chemotherapeutic agents. As with most invasive procedures, central venous catheterization is associated with numerous potential complications such as infection, thoromboembolism and occlusion. A rare but serous complication is the catheter fracture. We present here three cases of catheter fracture as a consequence of Pinch off syndrome, and we include a review of the relevant literature.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.151-159
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• 2001

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the ageing evaluation technique by the BI method. The four classes of the thermally aged 1Cr-!mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method within 5%. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.171-176
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• 2000

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the aging evaluation technique by the BI method. The four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• Journal of Acupuncture Research
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• v.39 no.1
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• pp.64-69
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• 2022

The risk of stress fractures is associated with rheumatoid arthritis (RA), which can aggravate bone loss. We report the case of a patient who was on long-term medication for RA presenting with lower extremity pain on the left and swelling without trauma. Magnetic resonance imaging and plain radiographs at the previous hospital showed no signs of fracture, but radiographs performed later, revealed a stress fracture of the left distal tibia. The stress fracture may have occurred due to multiple reasons such as long-term use of methotrexate and glucocorticoids, active RA, postmenopausal state, and immobility. Suspicion of a stress fracture should not be ruled out especially in RA patients with persistent pain, even if the radiographical findings are normal. Additional imaging and follow-ups are essential. The patient's pain was relieved with Korean medicine treatments, which suggests their potential application for stress fractures in RA patients.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.473-481
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• 2006

Predicting fatigue life by numerical methods was almost impossible in the field of rubber materials. One of the reasons is that there is not obvious fracture criteria caused by nonstandardization of material and excessively various way of mixing process. But, tearing energy as fracture factor can be applied to a rubber-like material regardless of different types of fillers, relative to other fracture factors and the crack growth process of rubber could be considered as the whole fatigue failure process by the existence of potential defects in industrial rubber components. This characteristic of fatigue failure could make it possible to predict the fatigue life of rubber components in theoretical way. FESEM photographs of the surface of industrial rubber components were analyzed for verifying the existence and distribution of potential defects. For the prediction of fatigue life, theoretical way of evaluating tearing energy for the general shape of test-piece was proposed. Also, algebraic expression for the prediction of fatigue life was derived from the rough cut growth rate equation and verified by comparing with experimental fatigue lives of dumbbell fatigue specimen in various loading condition.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.31.1-31.5
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• 2015

Background: Pathologic fractures are caused by diseases that lead to weakness of the bone structure. This process sometimes occurs owing to bony change after radiation therapy. Treatment of pathologic fractures may be difficult because of previous radiation therapy. Methods: In this study, we analyzed clinical and radiographic data and progress of five patients with mandibular pathological fractures who had received postoperative radiation therapy following cancer surgery. Result: Patients received an average radiation dose of 59.2 (SD, 7.2) Gy. Four of five patients exhibited bone union regardless of whether open reduction and internal fixation (OR/IF) was performed. Patients have the potential to heal after postoperative radiation therapy. Treatment of a pathologic fracture following postoperative radiation therapy, such as traditional treatment for other types of fractures, may be performed using OR/IF or CR. OR/IF may be selected in cases of significant bone deviation, small remaining bone volume, or occlusive change. Conclusion: Patients have the potential to heal after postoperative radiation therapy.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.3
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• pp.23-44
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• 2020

Objectives The purpose of this study is to evaluate the healing effect of Hyeolbuchugeo-tang (HC) in rats with rib fracture. Methods Rats were randomly divided into 5 groups (naive, control, positive control, HC-L and HC-H). All groups except naive group were subjected to bone fracture of rib. Naive group received no treatment at all. Control group was fed with phosphate buffered saline. Positive control group was orally medicated with tramadol. Experimental group was orally medicated with HC extract (50 mg/kg for low concentration [HC-L], 100 mg/kg for high concentration [HC-H]). X-ray and micro-computed tomography (micro-CT) were conducted to assess the effect of HC. We analysed the level of 2) transforming growth factor-β1 (TGF-β1), Ki67, alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-β, runt-related transcription factor 2 (Runx2) and tartrate resistant acid phosphatase (TRAP) on 7 and 14 days after fracture. ALP, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine was measured for safety assessment. Results X-ray and micro-CT, showed HC enhance bone repair process. Callus formation was increased in experimental group at 7 days after fracture, but decreased at 14 days after fracture. 7 days after fracture, the level of TGF-β1 in experimental group was decreased. The level of Ki67, Runx2 in HC-H, TRAP in HC-L was increased. 14 days after fracture, the level of Ki67 in HC-L and HC-H was decreased. The level of ALP, Runx2, BUN in HC-L, TRAP in HC-L and HC-H was increased. Conclusions Taken together the results, HC promoted healing of bone fracture. In conclusion, HC has a potential to promote healing of bone fracture.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.273-275
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• 2002

The effect of post-weld heat treatment (PWHT) of marine structures steel was investigated at electrochemical viewpoint. In addition, slow strain rate test (SSRT) was carried out to investigate both electrochemical and mechanical properties by PWHT effect during impressed current cathodic protection. The optimum cathodic protection potential by SSRT was -770 mV(SCE). At the applied cathodic protection potential of -770 mV -850 mV(SCE), the fracture morphology was dimple pattern with ductile fracture, while it was transgranular pattern (Q.C: quasi cleavage) under -875 mV(SCE).

• Corrosion Science and Technology
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• v.15 no.5
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• pp.203-208
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• 2016

DC potential drop technique was employed during the slow strain rate tests to study the hot salt stress corrosion crack (HSSCC) initiation at 300 and $400^{\circ}C$. Threshold stresses for HSSCC initiation were found to about 88 % of the yield strength at both temperatures, but the time from crack initiation to final failure (${\Delta}t_{scc}$) decreased significantly with temperature, which reflects larger tendency for brittle fracture and secondary cracking. The brittle fracture features consisted of transgranular cracking through the primary ${\alpha}$ grain and discontinuous faceted cracking through the transformed ${\beta}$ grains.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.3-8
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• 1990

A new finite element technology based on p-version of F.E.M. is discussed with reference to its potential for application to stress intensity factor computations. In linear elastic fracture mechanics, especially cracked cylindrical shells. It is shown that the p-version nutlet is far better suited for computing the stress intensity factors than the conventional h-version models with the help of three test problems. The main advantage of this technology is that the accuracy of approximation can be established without mesh refinement or the use of special procedures.