• Corrosion Science and Technology
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• v.2 no.4
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• pp.194-196
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• 2003

In this paper, a newest kind of anti-atmospheric corrosion method is introduced. This method does not adopt organic coating, plastic layer or metal plating, instead it adopts a kind of aqueous emulsion containing numerous tine solid compounds that are absorbed onto the component surface, which play the role of anti-electrochemical corrosion.

• Magazine of RCR
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• v.16 no.1
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• pp.8-11
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• 2021

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.282-286
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• 2017

Beta tricalcium phosphate (${\beta}-TCP$) is one of allogenic bone substitute which is known to have interconnected pores that draws cell and nutrients for bone generation. It has been resulted in good outcomes for bone defect coverage or augmentation. However, several studies have also reported negative outcomes and associated complications including unexpected formation of cystic mass, continuous pain and secretion. We present the case of a 36-year-old man with a right cheek cystic mass who had a history of right zygomaticomaxillary (ZM) complex fracture and surgical correction with ${\beta}-TCP$ powder insertion to ZM bone defect. Excisional biopsy under local anesthesia revealed calcified mass in a sinus tract which was found to be connected to the ZM bone defect site in postoperative computed tomography image. Further excision under general anesthesia was performed to remove the sinus tract and fine granules which filled the original defect site. Pathologic report revealed bony spicules and calcification materials with chronic foreign body reaction. Postoperative complications and recurrence were not reported.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.129-137
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• 2008

An active application of concrete track is being expected far the future constructions of Korean railroad. In comparison with the existing ballasted tract, a concrete track is very susceptible for the settlement, since its rehabilitation requires much time and cost. When a concrete track is constructed on fine-grained subgrade soil, excessive cumulative plastic settlements due to repetitive train road may occur. In this case, the settlement of the concrete track may be effectively reduced by installing a small number of small-diameter piles beneath the track. This paper presents the effect of pile installation on the reduction of cumulative plastic settlement of concrete track. A method combining experiential equation and numerical method is proposed. Using an existing experiential equation and the estimated earth pressure distribution, the cumulative plastic strain was calculated. From the results, it is verified that the effects of the pile installation is significant to effectively reduce the cumulative plastic settlement of concrete track. The reduction effects of the cumulative plastic settlement according to the pile number and pile arrangement are presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.10
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• pp.1492-1499
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• 2004

In this paper, defect formation in ring rolling is revealed by computer simulation of ring rolling processes. The rigid-plastic finite element method is employed for this study. An analysis model having relatively fine mesh system near the roll gap is used for reducing the computational time and a scheme of minimizing the volume change is applied. The formation of the central cavity formation defect in ring rolling of a taper roller bearing outer race and the polygonal shape defect in ring rolling of a ball bearing outer race has been simulated. It has been seen that the results are qualitatively good with actual phenomena.

• Transactions of Materials Processing
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• v.18 no.2
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• pp.116-121
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• 2009

Formability and other mechanical properties of sheet metals are strongly dependent on the texture. It was studied to improve the formability of the Al alloy(AA3003) sheets which were rolled under the non-lubrication condition and subsequent heat treated. In the non-lubrication rolled and subsequent heat treated Al alloy sheet, the variation of the plastic strain ratios were investigated in this study. Non-lubrication rolled Al sheets showed a fine grain size and after subsequent heat treated specimens showed that the $\beta$-fiber texture component was increased. The plastic strain ratios of the non-lubrication rolled and subsequent heat treated Al alloy sheets were about two times higher than those of the original Al sheets. These could be related to the formation of $\beta$-fiber texture components through the non-lubrication rolling and subsequent heat treatment in Al sheet.

• Transactions of Materials Processing
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• v.18 no.7
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• pp.513-518
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• 2009

Large load is required in forging of large-scale components which becomes a critical restriction in practice. In the present study, two methods of incremental forging were investigated for the purpose of reducing the load required for forging of large and thick plates. The forging was applied primarily to obtain fine grains by imposing large amount of plastic deformation to the plates. One was to use nine strokes with a flat die and the other was to use three strokes with a curved die. The die moves vertically in the former while it moves vertically as well as rolls horizontally in the latter. Deformation of the slab in each case was analyzed by rigid-plastic finite element method and as a result, variations of load and slab holding force, and distributions of effective strain and thickness were predicted.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.805-810
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• 2003

It is the real circumstance in the country that not only the data and special books but also people who have an expert knowledge are short of the field of the study about plastic wastes, so that to build the Database carrying out gathering info of that is the present question obviously. The business on recycling plastic, for some reason or other, is one of the best ways as called bright prospect industry to prevent environmental pollution and obtain economical outcome by using limited resources. Plastic wastes with construction industry especially using Polymer may have a good effect on the environment and human beings and have a fine view to produce functional and Eco-friendly concrete as well. In this study, Chemical resistance and Water Absorption test in Polymer concrete using bentonite as a shrinkage control agent was made an experiment by comparing with influence on concrete strength and used to offer some valuable data about Polymer concrete.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.43-44
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• 2006

The production method of micro sacrificial plastic mold insert metal injection molding, namely ${\mu}-SPiMIM$ process has been proposed to solve specific problems involving the miniaturization of MIM. Two types of sacrificial plastic molds (SP-mold) with fine structures were used: 1) PMMA resist, 2) PMMA mold injected into Ni-electroform, which is a typical LIGA (${\underline{L}}ithographie-{\underline{G}}alvanoformung-{\underline{A}}bformung$) process. Stainless steel 316L feedstock was injection-molded into the SP-molds with multi-pillar structures. This study focused on the effects of metal particle size and processing conditions on the shrinkage, transcription and surface roughness of sintered parts.

• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.807-812
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• 1998

Mechanical properties of two types of polycrystlline {{{{ { { Ti}_{3 }SiC }_{2 } }} with different grain size were investigated. A fine grain {{{{ { { Ti}_{3 }SiC }_{2 } }} has a higher fracture strength and hardness. Plot of strength versus Vickers indentation load indicated that {{{{ { { Ti}_{3 }SiC }_{2 } }} has a high flaw tolerance. Hertzian indentation test using a spherical indenter was used to study elastic and plastic behavior in {{{{ { { Ti}_{3 }SiC }_{2 } }}. Indentation stress-strain curves of each material are made to evaluate the plasticity of {{{{ { { Ti}_{3 }SiC }_{2 } }} Both find and coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} showed high plasticity. In-dentation stress-strain curve of coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} deviated even more from an ideal elastic limit in-dicating exceptional plasticity in this material. Deformation zones were formed below the contact as well as around the contact area in both materials but the size of deformation zone in coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} was much larger than that in fine grain {{{{ { { Ti}_{3 }SiC }_{2 } }} Intragrain slip and kink would account for high plasticity. Plastic behavior of {{{{ { { Ti}_{3 }SiC }_{2 } }} was strongly influenced by grain size.