• Proceedings of the KSME Conference
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• 2003.04a
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• pp.137-142
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• 2003

In this study, the propagation behavior of fatigue crack effected hole defects was investigated under mixed-mode I+II loading. To create mixed-mode stress field at crack tip, the compact tension shear (CTS) specimen and loading device were used in this tests. The propagation experiments of fatigue crack were performed by changing of the loading application angle(${\phi}$) and the distance(L) estimated from pre-crack tip to hole center located side by side by side with a pre-crack. As L changes, the variation for propagation aspect of fatigue crack, fatigue life and crack propagation rate were examined under mixed-mode loading. Under mixed-mode loading, the propagation rate of fatigue crack increased while the propagation direction changed dramatically because of the interference of hole defects.

• Korean Journal of Materials Research
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• v.9 no.7
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• pp.670-674
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• 1999

Accurate measurements of elastic constants are important from the view points of both science and engineering. The measurement can be viewed from scientific principle as a service tools for analyzing and improving the understanding of the nature of bondings between atoms and between ions. Also, from engineering perspective it would became an important factor to be definitely considered for the design of machinery equipments. In this investigation, two dynamic experimental methods of vibrations (acoustic method and Impulse technique method) are utilized and the results from the both methods are compared to obtain elastic constants data with a high degree of accuracy. The resonance frequencies obtained from the two methods are applied to both Euler and Timoshenko beam equations respectively, to determine the sources for possible differences.

• Preventive Nutrition and Food Science
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• v.10 no.3
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• pp.219-223
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• 2005

[ $\beta-Cryptoxanthin$ ] content was determined in Shiranuhi mandarin fruits harvested at monthly intervals from October to February in Jeju Island. Crude carotenoids were extracted from both peel and flesh of Shiranuhi mandarin fruits and analyzed using TLC and HPLC; $\beta-cryptoxanthin$ was indicated the Rr value of 3.2 and retention time of 23 min, respectively. $\beta-Cryptoxanthin$ contents in both peel and flesh were increased gradually as the citrus fruits ripened fully until harvesting season (February). According to the harvesting time, $\beta-cryptoxanthin$ contents in the peel were $0.15\;mg\%\;(October),\;0.28\;mg\%\;(November),\;0.38\;mg\%\;(December),\;1.23\;mg\%\;(January),\;and\;1.71\;mg\%\;(February).$In the flesh, $\beta-cryptoxanthin$ contents were lower than those of peels, having $0.06\;mg\%\;(October),\;0.08\;mg\%\;(November),\;0.19\;mg\%\;(December),\;0.26\;mg\%\;(January),\;and\;0.65\;mg\%\;(February).$ These results demonstrate that $\beta-cryptoxanthin$ in Shiranuhi mandarin fruits accumulated during ripening of the citrus fruits. In particular, the peels had much higher concentrations of $\beta-cryptoxanthin$ and have potential for use as a functional ingredient.

• Analytical Science and Technology
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• v.12 no.3
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• pp.184-189
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• 1999

$^{51}V$ NMR and cyclic voltammetry studies on the interaction of vanadate and N-benzyliminodiacetate (Bz-IDA) in aqueous solution have been studied. From the NMR spectra two $^{51}V$ NMR peaks resulting at -515.5 and -500.1 ppm, due to the complexations between vanadate(V) and Bz-IDA at pH 5. has been observed. From the cyclic voltammograms the reduction-oxidation of the vanadate(V) complex has been found to be one-electron reaction.

• Imaging Science in Dentistry
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• v.31 no.2
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• pp.117-120
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• 2001

A 66-year-old man visited author's institute complaining of the swelling on the submandibular gland area. Clinically, the exophytic mass penetrated the skin of the submandibular area. On MRI, the lesion occupied the left submandibular space and extended downward, protruding exterior to the subcutaneous fat layer, but the center of the lesion was located on the side of the skin and the growth exterior to the skin was prominent. Demarcation of the lesion and the submandibular gland was unclear. Histopathologically the epithelial nests and keratin production were seen, then the biopsy result was squamous cell carcinoma. The stroma of lesion showed a myxoid characteristic and some ducts showed metaplasia of the ductal cells, which suggested the gland-origin carcinoma. However, lots of keratin production and carcinomatous change of cells continuous to the normal epithelium of the skin, the skin-origin carcinoma invading into the submandibular gland area could not be excluded.

• Archives of Craniofacial Surgery
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• v.18 no.3
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• pp.207-210
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• 2017

Sarcoidosis is a systemic inflammatory disease characterized by non-caseating granulomas of unknown origin. Of the fewer than 6% of sarcoidosis cases that occur in subcutaneous tissue, most occur on the face or forearm, but rarely in the toe. A 33-year-old man was admitted to our institute with a 2-cm mass on his chin and a 0.5-cm mass on his right fourth toe. Based on preoperative ultrasonography, epidermal cysts were suspected, and histopathological tests were performed after removing the masses. Histopathologically, the chin and toe tissue samples showed chronic granulomatous inflammation, without necrosis, indicative of sarcoidosis. Chest computed tomography revealed a large number of small nodules in both the interlobar fissures and the peribronchial area, and a large number of small lymph nodes in both the hilar and interlobar node areas. On the basis of the histopathologic and imaging findings, the patient was diagnosed with sarcoidosis. This very rare case of sarcoidosis, occurring in both chin and toe, suggests that thorough evaluation is needed to find other mass when we find sarcoidosis in facial area.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.49-54
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• 2010

An integrated machining center is developed for high precision and productivity manufacturing. The developed machine is composed of the high precision spindle using ball bearings, the high stiffness bed and the three axis CNC controller with the high resolution AC servo motor. In this paper, structural and modal analysis for the developed machine are carried out to check the design criteria of machine. The analysis is carried out by FEM simulation with using the commercial software, CATIA V5, ANSYS and ARMD. The simulation model of machine is made by shell and solid finite elements. This study also presents the measurement system on the modal analysis of an integrated machining center. The weak part of the machine is found by the analytical evaluation. The results provide with the structural modification data for good dynamic behaviors. And the safety of machine is confirmed by the modal analysis of modified machine design. As this study results can be trustworthy with the analysis of ANSYS and CATIA, integrated machining center can be successfully developed.

• Archives of Craniofacial Surgery
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• v.22 no.5
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• pp.280-284
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• 2021

Primary cutaneous marginal zone B-cell lymphoma (PCMZL) is an uncommon type of malignant lymphoma that mainly occurs in the trunk and upper extremity, with less frequent incidence observed on the head. Herein, we report the early diagnosis and treatment of a rare case of facial PCMZL in an Asian patient. A 51-year-old man presented with masses on the forehead and nose tip, which he had incidentally discovered 2 months previously. The masses appeared as a papule on the forehead and a patch on the nose. There were no signs of infection or bleeding, and the patient reported no other symptoms. After complete surgical excision, PCMZL was diagnosed based on the permanent biopsy. The histopathological findings revealed lymphoid aggregations with multifocal granulomas. Further treatment and follow-up were conducted at the hematology and oncology department. Despite its rarity in Asian populations, cutaneous lymphoma should be included in the differential diagnosis of facial masses. Early diagnosis and treatment based on a physical examination, imaging study, and excisional biopsy are important for a favorable prognosis.

• 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.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.435-440
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• 2022

Mucormycosis is a rare, invasive fungal infection that progresses aggressively and requires prompt surgery and appropriate treatment. The number of cases of mucormycosis in coronavirus disease 2019 (COVID-19) patients has recently increased, and patients with uncontrolled diabetes mellitus are particularly at an elevated risk of infection. This report presents a case of mucormycosis-related osteomyelitis of the maxilla in a 37-year-old man with diabetes mellitus. The patient complained of severe and persistent pain in the right maxilla, accompanied by increased tooth mobility and headache. On contrast-enhanced computed tomographic images, gas-forming osteomyelitis of the right maxilla was observed. Destruction of the maxilla and palatine bone then proceeded aggressively. Sequestrectomy was performed on the right maxilla, and the histopathological diagnosis was mucormycosis. Further investigation after the first operation revealed the patient's history of COVID-19 infection.