• 한국분말재료학회지
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• 제9권3호
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• pp.148-152
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• 2002

The microstructures and indentation fracture of pressureless-sintered $DyNbO_4$ crystalline were investigated as a basic study for the application of weak phase of fibrous monolithic composites. They were comprised with many lamella twins as well as micro-cracks at the grain boundaries. The hardness at room temperature was remarkably low value(575 Hv) due to the low relative density and existence of microcracks at grain boundaries. The main fracture mode was a typical intergranular fracture, and showed remarkable micro-cracking effect. The heavy plastic deformation was observed around the site of indentation. In addition, the $DyNbO_4$ was expected to apply as a weak phase in the fibrous monolithic composites because of the low hardness and easily plastic deformation that could be led the preferable pulled-out and microcracking toughening under the failure.

• Journal of Korean Neurosurgical Society
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• 제30권12호
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• pp.1439-1442
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• 2001

Solitary fibrous tumor(SFT) is a spindle cell neoplasm that usually arises in the pleura. Its involvement of the meninges is rare but increasingly being reported. Our case was a 33-year-old man who presented with clonic seizure around the right mouth angle and sensory disturbance at the right hand. Radiological studies showed a large extra-axial, dural-based mass in the left fronto-parietal region, typically isointense with gray matter and heterogeneous strong enhancement on T1-weighted images. Histologically, the tumor was composed of spindle-shaped cells growing in fascicles within the collagenous matrix. Immunohistochemical staining demonstrated diffuse CD34 positivity. Awareness of this neoplasm is necessary to accurate diagnosis.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.65-69
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• 2002

An Al film deposited on the Kovar alloy substrate was anodically-bonded to the borosilicate glass, and the bond interfaces was closely investigated by transmission electron microscopy. Al oxide was found to form a layer ~l0 nm thick at the bond interface, and fibrous structure of the same oxide was found to grow epitaxially in the glass from the oxide layer. The fibrous structure grew with the bonding time. The mechanism of the formation of this fibrous structure is proposed on the basis of the migration of Al ions under the electric field. Penetration of Al into glass beyond the interfacial Al oxide was not detected. The comparison of the amount of excess oxygen ions generated in the alkali depletion layer with that incorporated in the Al oxide suggests that the growth of the alkali-ion depletion layer is controlled by the consumption of excess oxygen to form the interfacial Al oxide.

• Journal of Chest Surgery
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• 제20권2호
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• pp.358-366
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• 1987

A case of malignant fibrous histiocytoma [MFH] of left pulmonary artery was reported in the 27 year-old male. He was admitted because of hemoptysis for several times. Chest x-ray revealed nodular lesions in left hilar area and left upper lobe. A left thoracotomy was performed followed left upper lobectomy. The main tumor was originated from the pulmonary arterial bifurcation and proximal portion of the left pulmonary artery. By light microscopy, there were many pleomorphic giant cells, which displayed the storiform pattern. And in those area, dilated or compressed vascular channels were involved by tumor cells, suggesting origin of This tumor. Pulmonary artery angiography and chest CT revealed this tumor was originated from pulmonary artery. It would be the first reported primary malignant fibrous histiocytoma of the pulmonary artery in our country. Postoperative prognosis was uneventful, but recently he was suffered from dyspnea, that was noticed by OVD follow-up for 1 month, probably the heart failure sign due to pulmonary arterial flow obstruction.

• Korea-Australia Rheology Journal
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• 제21권1호
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• pp.71-79
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• 2009

The incomplete saturation and the void formation during the resin infiltration into fibrous porous media in the resin transfer molding process cause failure in the final product during its service. In order to better understand flow behavior during the filling process, a finite-element scheme for transient flow simulation across the micro-structured fibrous media is developed in the present work. A volume-of- fluid (VOF) method has been incorporated in the Eulerian frame to capture the evolution of flow front and the vertical periodic boundary condition has been combined to avoid unwanted wall effect. In the microscale simulation, we investigated the transient filling process in various fiber structures and discussed the mechanism leading to the flow fingering in the case of random fiber distribution. Effects of the filling pressure, the shear-thinning behavior of fluid and the volume fraction on the flow front have been investigated for both intra-tow and the inter-tow flows in dual-scale fiber tow models.

• 한국입자에어로졸학회지
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• 제5권1호
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• pp.9-16
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• 2009

Pressure drop and particle removal efficiency of two commercial fibrous medium filters were measured with 20~1,000 nm sized aerosolized KCl particles. Pressure drop and particle removal efficiency were also theoretically predicted and the results qualitatively agreed with the experimental data. For this given particle removal efficiency, a filter design method for obtaining minimum pressure drop (and therefore minimum fan power) was suggested in this study by selecting solidity and fiber diameter as parameters. Therefore, by carrying out theoretical and experimental approaches together, this paper introduced a way of finding conditions for low pressure drop and high performance of a fibrous filter, especially if the filter would be used in mechanical ventilation system.

• 한국입자에어로졸학회지
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• 제10권3호
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• pp.99-108
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• 2014

Liquid filtration by membrane filters is essential for the preparation of ultrapure water in semiconductor manufacturing processes. The separation of submicrometer particles suspended in ultrapure water with a laminated fibrous membrane filter was studied numerically and experimentally in the present work. We found that an electrical double layer around a single fiber expanded to a large extent at a low ion concentration, as in ultrapure water, and deformed toward the upstream of the fiber with increasing filtration velocity. Since an increase in the electrical double-layer thickness leads to a decrease in the electrical potential gradient, particles with the same polarity as the fiber approach the fiber more easily and are captured at a high filtration velocity. Experimental results also confirmed that the collection efficiency of polystyrene latex(PSL) particles through a PTFE filter became higher as the filtration velocity increased.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.61-64
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• 2001

This study evaluated the use of endoscopy to examine jaw cysts during the operation. Fifteen jaw cysts were explored with a endoscope immediately before and after enucleation. Endoscopic findings were evaluated and recorded with video tape. Before enucleation, there were many white fibrous floating materials within the cystic cavity. Cystic lining showed smooth and regular appearance with capillary network. However, there were some fibrous scar tissues and irregular architecture in preoperative infection. After enucleation, there were white shiny bony surfaces with fresh vascular network. In some cases, floating fibrous tissues remained after removal.

• 한국주조공학회지
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• 제16권6호
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• pp.523-536
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• 1996

This paper relates to fabrication processing analysis of metal matrix composites by the injection of liquid metal into a fibrous preforms. One dimensional heat transfer analysis during squeeze infiltration process of aluminum base composites has been studied. An analysis method was investigated for the temperature distribution, infiltration velocity and melt infiltration characteristics with the commercial preform with short fiber array. When molten metal is infiltrated in a fibrous preform with random orientation, phase transformation will be occurred in a region such as molten metal, solidified region, preform region and infiltration composites region. a mathematical modelling for a solidification phenomena in fabrication process of metal matrix composites using a squeeze infiltration technique was investigated by the basic relations for liquid metal into a fibrous preform. The temperature distribution of theoretical results was compared with experimental data.

• 대한세포병리학회지
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• 제10권2호
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• pp.151-155
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• 1999

A case of primary malignant fibrous histiocytoma(MFH) of the lung occurring in a 62-year-old man is presented. After preoperative bronchial blushing and washing cytologic diagnosis of poorly differentiated carcinoma, surgical resection and lymph nodes dissection were performed. Subsequent histologic examination revealed a primary MFH. The diagnosis was confirmed by electron microscopic and immunohistochemical examinations. The review of the bronchial brushing and washing cytologic features disclosed many bipolar and a few unipolar spindle tumor cells with a "comel" configuration, mainly single cells, but also forming loose clusters. The nuclei were elongated and hyperchromatic and contained one or more irregular nucleoli. Scattered bizarre, multinucleated tumor giant cells were also present.