• Journal of the Korean Ceramic Society
• /
• v.34 no.7
• /
• pp.758-766
• /
• 1997

Non-brittle fracture behaviour of the two composite structures made of two different brittle materials was investigated using 3-point bending test. First, the layered and fibrous macro-composites were fabricated using the material easily formed, yet showing a brittle fracture behaviour similar to ceramics. The layered and fibrous Al2O3 /Al2O3 composites with weak interface were also fabricated using plate of 2 mm thickness and rod of 3 mm diameter respectively. Comparison of the mechanical properties between these two structures was performed in the lights of flexural strength and work of fracture for the composites consisting of Al2O3 and simulated materials respectively. The strength ratio of layered structure to the monolith of same volume was 0.6 and the ratio of fibrous one was about 0.2 for the composites made of simulated brittle material. The ratio of the work of fracture of the fibrous to the layered was 0.47. For Al2O3/Al2O3 composites, the strength ratio of layered and fibrous structures to the monolith with same volume were about 0.6 and 0.2 respectively. The ratio of work of fracture of the fibrous to the layered was 0.6. These confirmed that the layered structure was superior to the fibrous one in terms of flexural strength and work of fracture.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.31.1-31.7
• /
• 2020

Background: Fibrous dysplasia (FD) is a rare, sporadic, and benign congenital condition in which normal cancellous bone is replaced by fibro-osseous tissue with immature osteogenesis. FD localized in the cranial and facial bones is called craniofacial fibrous dysplasia (CFD). Cystic degeneration in CFD cases is rare; cystic degeneration appearing in both the maxilla and the mandible FD lesion is even rarer. The aim of this article was to report a case of fibrous dysplasia of the mandible and maxilla complicated by nonspecific cystic degeneration. Case presentation: A 30-year-old woman presented with a rare case of non-specific cystic degeneration in a mandible and maxilla FD lesion that occurred 11 years after surgery. She was diagnosed with polyostotic CFD and underwent maxillary and mandibular bone contouring. Cyst enucleation under general anesthesia was performed in the mandibular region due to pain and discomfort. Conclusions: In cases involving non-aggressive and non-invasive FD cystic degeneration in focal areas, conservative treatment is recommended. However, if cystic degeneration of FD develops rapidly and causes discomfort, pain, or dysfunction, surgical treatment should be considered.

• Macromolecular Research
• /
• v.15 no.5
• /
• pp.424-429
• /
• 2007

A procedure for the surface hydrolysis of an electrospun poly(${\epsilon}$-caprolactone) (PCL) fibrous scaffold was developed to enhance the adhesion and proliferation of osteoblasts. The surface hydrolysis of fibrous scaffolds was performed using NaOH treatment for the formation of carboxyl groups on the fiber surfaces. The hydrolysis process did not induce deformation of the fibers, and the fibers retained their diameter. The cell seeding density on the NaOH-treated PCL fibrous scaffolds was more pronounced than on the non-treated PCL fibers used as a control. The alkaline phosphatase activity, osteocalcin and a mineralization assay strongly supported that the surface-hydrolyzed PCL fibrous scaffolds provided more favorable environments for the proliferation and functions of osteoblasts compared to the non-treated PCL fibrous scaffolds use as a control.

• Journal of Korean Neurosurgical Society
• /
• v.56 no.1
• /
• pp.58-60
• /
• 2014

Spinal meningiomas typically adhere to the dura matter. Non-dural based spinal meningiomas are rare and most are clear cell meningiomas. We report here the first case of a fibrous meningioma with non-dural attachment. The patient was a 49-year-old female, who complained of numbness in the legs and a gait disturbance. Magnetic resonance imaging revealed a $1.7{\times}1.4-cm$ mass in the C7-T1 intra-dural extramedullary space, showing peripheral gadolinium enhancement without a "dural tail sign". A complete microsurgical resection was performed. The mass was covered with a white membrane but was not adhered to the dura, and its appearance was consistent with a neurilemmoma. The histopathological diagnosis was fibrous-type meningioma. The recovery of the patient was uneventful. No surgical complications and no recurrence of the tumor had occurred at the 6-month follow-up.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.41 no.4
• /
• pp.82-90
• /
• 2009

It is very important to utilize effectively fibrous waste paper in terms of cost savings, environmental effects, and governmental policies. The quality of final products and runnability of papermaking process are primarily affected by constitutions of fibrous raw materials. In specific, board grade paper depends directly on compositions of waste paper bales. At present, the raw materials of board grade paper are mainly derived from lots kinds of wastepaper. Some papermaking countries, like EU, USA and Japan have advanced classification and management systems of recycled fiber, but Korea has not yet organized systematically. In this study, evaluation of wastepaper bale compositions and their fiber properties were carried out for effective utilization of fibrous raw materials for board grade paper production. 3 kinds of wastepaper bales were classified to fibrous or non-fibrous materials. In case of fibrous materials, KOCC, kraft sack paper and white duplex board matters were main component in total weight basis, and in case of non-fibrous materials, vinyl, plastic and cloth matters were main component, in turns. 3 representative kinds of waste paper were disintegrated and classified, and then prepared to handsheet for evaluation of recycled fiber property. Consequently, fines and ash content of waste paper, isolated from KOCC and white duplex board were higher than that of kraft sack paper. pH values of all kinds of waste fibers were neutral or weak alkaline.

• Journal of Chest Surgery
• /
• v.24 no.6
• /
• pp.595-604
• /
• 1991

Pleural mesothelioma is usually divided into two forms of localized and diffuse type. Localized pleural fibrous mesothelioma is uncommon mesodermal neoplasm, which may occurs in both sexes and at the age of 50 years. This type of mesothelioma is usually asymptomatic and detected on routine chest X-ray and made fibrous tissue and shows of collagen fibers microscopically. Most localized fibrous mesothelioma arises from the visceral pleura and is well encapsulated and pedunculated mass. CT findings included well delineated, often lobulated, non-calcified soft tissue masses in close relation to a pleural space, associated pleural thickening, and absence of chest wall invasion and a peripheral or fissure location. Three cases of localized pleural fibrous mesothelioma diagnosed by resectional surgery were reported with the review of literature.

• Advances in concrete construction
• /
• v.4 no.1
• /
• pp.37-47
• /
• 2016

The objective of the present work is to evaluate the influence of two different methods of improving the ductility of Reinforced Concrete Frames and their influence on the full range behavior of the frames with M40 grade of concrete. For this purpose one fourth scale reinforced concrete square frames are experimentally tested subjected to static cyclic loading for three cases and monotonic loading for one case. The parameters are varied as method introducing ductility to the frame viz. (i) by using conventional concrete (ii) adding 1% of steel fibres by volume of concrete at hinging zones (iii) using self-compacting concrete with fibres at hinging zones. The energy absorption by ductile and non-ductile frames has been compared. The behavior of frames tested under cyclic loading have revealed that there is a positive trend in improvement of ductility of frames when fibrous concrete is used along with self-compacting concrete.

• The Korean Journal of Ceramics
• /
• v.4 no.3
• /
• pp.171-175
• /
• 1998

$Al_2O_3$-TiC composites were prepared from aluminum, titanium oxide, and carbon fibers by self-propagating high-temperature synthesis(SHS). After the SHS reaction, the TiC phase in the sample was found either fibrous or non-fibrous shape. The fraction of the fibrous TiC phase varied with the amount of $Al_2O_3$ diluent addition. The optimum amount of diluent to make fibrous carbide was determined to be 30%. The fibers were hollow inside and made of multiple grains with a composition of titanium carbide. The hollow fiber formation mechanism was suggested and discussed. The synthesized powders were consolidated to dense composites by hot pressing at $1750^{\circ}C$ under 30 MPa.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.4
• /
• pp.264-268
• /
• 2016

Benign fibrous histiocytoma (BFH) is a rare benign primary skeletal tumor that occurs commonly in the long bones, spine and pelvis. BFH constitutes a diagnostic challenge because it shares clinical background, radiological characteristics, and histological features with other fibrous lesions such as non-ossifying fibroma, giant cell tumor. We present a case of BFH with cystic change that occurred in the distal femur. We did not identify any case of BFH with cystic change involving the majority of the lesion that occurred in the metaepiphysis of the long bone.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.3
• /
• pp.50-58
• /
• 2005

It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.