• Journal of the Korean Society for Heat Treatment
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• v.34 no.2
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• pp.60-65
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• 2021

In this study, the effect of pressure type and foaming agent on the microstructural change of Al foam produced by powder compact processing was investigated. Better foaming characteristic is easily obtained from extrusion process with strong plastic deformation and preheating than that by uniaxial pressing with preheating. In current powder compact foaming process using TiH2/MgH2 mixture as a foaming agent, a temperature of 670℃ and addition of 30% MgH2 in TiH2 foaming agent was chosen as the most suitable foaming condition. The aluminum (Al) foams with maximum porosity of around 70%, relatively regular pore size and distribution were successfully produced by means of the powder metallurgy method and extrusion process.

• Transactions of Materials Processing
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• v.16 no.7
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• pp.530-537
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• 2007

This paper is concerned with the analysis of plastic deformation of bimetal co-extrusion process. Two sets of material combination have been adopted for analysis, i.e. combinations of Cu/Al and Fe/Al. In the first set of material combination, the selected materials are AA 1100 aluminum alloy as hard material and CDA 110 as soft one. This type of material selection is to examine the effect of hard core and soft sleeve and vice versa on the deformation pattern in terms of plastic zone and velocity discontinuity along the contact surface between construction materials. Four different cases of co-extrusion process in terms of material combination and interference bonding were simulated to investigate the effect of material arrangement between core and sleeve, and of bonding on the plastic zones and velocity discontinuity. In the other set of material combination, model materials used as core and sleeve were AA 1100 and AISI 1010, which are relatively soft and hard, respectively. Process parameters except diameter ratio of core to sleeve material such as semi-die angle, reduction in area in global sense and die comer radius have been set constant throughout the simulation to concentrate our effort on the analysis of influence of diameter ratio on deformation behavior such as deformation zone, surface expansion, exit velocity discontinuity between composite materials, and extrusion forces.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.406-412
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• 2014

In this study, flat-tubular-type alumina filters were manufactured using alumina powder of two sizes ($2.4{\mu}m$ ALM-44 and $0.4{\mu}m$ AP 400) by an extrusion process. The manufactured alumina filter was sintered at $1200-1600^{\circ}C$ for 1 h. As particle size increased, the largest pore size, average pore size and porosity increased; but density and linear shrinkage decreased. The alumina filter fabricated using ALM-44 powder sintered at $1500^{\circ}C$ was confirmed as the best water treatment filter after investigation of the bending strength, water permeability and impurity-removal efficiency of the experimental filters. This flat-tubular-type alumina filter is expected to be useful not only for direct water treatment, but also for use as a support filter during coating processes, to control pore size.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.455-462
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• 2000

The characteristic of “Korea LRT Carbody” is designed by using AED(All Extrusion Design) method. This is developed in Europe and be introduced in this paper minutely. The window type of “Korea LTR” has no supported frame, so the passengers ensure the outside view widely. The passenger's door will designed by plug type - This is the first time in Korea. In this report we have an object to the strength analysis for the carbody design. For the purpose of safety and lightening, we are going to research the section of thickness through optimization design.

• Composites Research
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• v.12 no.5
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• pp.87-97
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• 1999

A clad material is a different type of the typical composites which are composed of two or more matericals joined at their interface surface. The advantge of cald material is that the combination of different materials can satisfy both the need of good mechanical properties and the other demand of user such as electrical properties instantaneously. This paper is concerned with the direct and indirect extrusion processes of copper-clad aluminum rod. Extrusion of copper-clad aluminum rod was simulated using a commercially available finite element package of DEFORM. The simulations were performed for copperclad aluminum rod to predict the distributions of temperature, effective stress, effective strain rate and mean stress for sheath thicknesses, die exit diameters and die temperatures.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.3 no.1
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• pp.37-48
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• 2008

Objective : In treatment of lumbar spine herniation of nucleus pulpous, the different result in accordance with difference of sex, age, medical history, part, or type. Methods : After 49 patients who were diagnosed as HNP of L-spine were grouped by sex, age, medical history, part, or type, they were compared and analyzed on the basis of difference between measuring VAS and ODI as they were hospitalized and as they were discharged. Results : 1. In terms of differences by gender, males' average degree of VAS improvement was 63.92 and females' average degree of VAS improvement was 59.8. Also, Males' average ODI improvement index was 12.36 and females' average ODI improvement index was 12.5. 2. In terms of differences by age, Teens recorded highest degree of VAS improvement and ODI improvement index. 3. In terms of differences by medical history, Most acute or acute patients showed higher degree of VAS improvement and ODI improvement index than subacute or chronic patients. 4. There were no significant distinguishing markscomparing between one diseased part and other. 5. As the research that focused on different type, Extrusion type had better improvement by medical treatment than Protrusion type. Conclusion : This research drew the result as above, but recognizable statistical relation could not be found in the result. Therefore there needs much sustainable research to deduce meaningful result.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.2.1-2.10
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• 2018

Objectives: To determine the effect of size and insertion depth of irrigation needle on the amount of apical extruded debris and the amount of penetration depth of sealer using a confocal laser scanning microscope (CLSM). Materials and Methods: Twenty maxillary premolars were assigned to 2 groups (n = 10), according to the size of needle tip, 28 G or 30 G. Buccal roots of samples were irrigated with respective needle type inserted 1 mm short of the working length (WL), while palatal roots were irrigated with respective needle type inserted 3 mm short of the WL. Prepared teeth were removed from the pre-weighed Eppendorf tubes. Canals were filled with F3 gutta-percha cone and rhodamine B dye-labeled AH 26 sealer. Teeth were transversally sectioned at 1 and 3 mm levels from the apex and observed under a CLSM. Eppendorf tubes were incubated to evaporate the irrigant and were weighed again. The difference between pre- and post-weights was calculated, and statistical evaluation was performed. Results: Inserting needles closer to the apex and using needles with wider diameters were associated with significantly more debris extrusion (p < 0.05). The position of needles and level of sections had statistically significant effects on sealer penetration depth (p < 0.05 for both). Conclusions: Following preparation, inserting narrower needles compatible with the final apical diameter of the prepared root canal at 3 mm short of WL during final irrigation might prevent debris extrusion and improve sealer penetration in the apical third.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.54-54
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• 2008

• The monthly packaging world
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• s.81
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• pp.152-160
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• 2000

CHEMICAL PRIMER와 ADHESION PROMOTOR라는 말은 자주 같은 뜻으로 서로 교환되어서 사용되어 왔다. 접착력의 촉진은 분명히 PRIMER로서 얻어지는 두드러진 특징 중에 하나이지만, PRIMER는 내화학성을 더하여 주는 추가적인 가치를 부여해준다. 이 발표문에서는 PRIMER의 TYPE와 접착에 영향을 주는 요인을 다루고 있다. 접착력과 내화학성은 코로나처리, 적용 COATING량, 적용방법 및 건조에 영향을 받는다. 압출수지온도,

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.515-523
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• 2010

Porous SiC candle filter preforms were fabricated by extrusion and ramming process. To fabricate SiC candle filter preform, commercially available F180 mesh ($85\;{\mu}m$) $\alpha$-SiC powder and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as the starting materials. The candle type preforms were fabricated by vacuum extrusion and ramming process, and sintered at $1400^{\circ}C$ 2 h in air atmosphere. Corrosion test of the sintered candle filter specimens as forming method was performed at $600^{\circ}C$ for 2,400 h in simulated IGCC syngas atmosphere. The effect of forming method on mechanical properties, pore distribution, microstructure and crystalline phase was investigated.