• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.1
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• pp.1-9
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• 2020

We evaluated the applicability of baking soda, charco'al, coffee, and green tea as a natural deodorant in Kimchi packaging. Moreover, to evaluate the potential usage of these deodorants in packaging materials and confirm their applicability in high-temperature melt-extrusion processing, the thermal stabilities of the deodorants were investigated, and heat-treated deodorants were evaluated in terms of the deodorizing function compared with non-treated deodorants. Aroma patterns were decreased after deodorizing treatment with all-natural deodorants. Dimethyl disulfide, methyl trisulfide, and diallyl disulfide, the most significant odorous Volatile organic compounds (VOCs) of Kimchi, decreased after treatment with the deodorants. In particular, baking soda and charcoal showed the highest efficiency in removing odorous compounds and VOCs from Kimchi, even after high-temperature processing. The acetic acid removal rates for both baking soda and charcoal were 99.9±0.0%. The heating process increases the deodorizing effects of baking soda. Sensory evaluation results showed that there is a significant increase (p < 0.05) in the overall preference for Kimchi samples packaged with charcoal and baking soda. This study provides useful information for the deodorization effects of natural deodorants for Kimchi smell and their applicability for packaging materials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.55-58
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• 2003

Many researches have been already done on the issues of high temperature deformation and the microstructural evolution. The information has been very useful for the plasticity industry, especially successful for the extrusion. However, the parts made with forging usually have a complex shape. It is difficult to control the distribution of the variables like strain, strain rate and temperature rise due to the working heat during a hot-forging process. Consequently, the microstructural variation could be occurred depending on the plastic deformation history that the forged part would get during a hot forging. In the present study, the microstructural characteristic of a hot-forged 6061 aluminum alloy has been discussed on the aspect of grain size evolution. A forging of 6061 aluminum alloy has been carried out for a complex shape with a dimensional variation. Also, finite element analysis has been done to understand how the deformation variables such as strain, strain rate give an influence on the microstructure of a hot forged aluminum product.

• Transactions of Materials Processing
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• v.22 no.2
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• pp.108-113
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• 2013

This paper demonstrates the lubricant performance in T-shape hot forging of Mg alloys. This processes induces complex plastic material flow of the initial billet such as simultaneous compression and extrusion deformations. Five lubricants with different amounts of graphite are applied to the T-shape forging at temperatures of 300 and $350^{\circ}C$. As the amount of graphite in the lubricant increases, the extruded depth gradually increases, which improves hot forgeability for Mg alloys. However, the lubricant performance decreases as forging temperature increases from 300 to $350^{\circ}C$. As the punch stroke increases, forgeability is considerably influenced by the lubricant. Thus, the selection of lubricants in hot forging of Mg alloys is critical when plastic deformation is severe.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.373-376
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• 2005

In recent years, there has been a growing need fur productivity improvement of ACS wire (Aluminum clad Steel wire) In optical communication market. So, it is necessary to improve the production speed and following quality of ACS wire to reduce the unit cost of the products. In this study, the pre-heating temperature and cladding speed is chosen as the factors can influence the mechanical and metallurgical properties during cladding, and the changing behavior of mechanical property and microstructure by controlling above two factors are investigated. And the bearing length and approach angle in cladding die are selected as the important elements for designing optimum die enabling high speed cladding. So we carried out FE(Finite Element) analysis using the above two elements as variables. This paper aims to understand the change of mechanical properties and microstructure according to the change of each factor during cladding and suggest the optimized cladding condition to get the best quality of OPGW. And also we would like to introduce the optimum die structure that enables high-speed cladding.

• Journal of Powder Materials
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• v.7 no.1
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• pp.35-41
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• 2000

Al2O3$.$SiC particle was prepared was prepared by the self-propagting high temperature sYthesis(SHS) process from a mixture of SiO2, Al and C powders, The fabricated Al2O3$.$SiC particle was applied to 2024Al/(Al2O3$.$SiC)pcomposite as a reinforcement. Aluminum matix composites were fabricares by the powder extrusion method using the synthesized Al2O3$.$SiC particle and commercial 2024Al powder. Theoptimum preparation conditions for Al2O3$.$SiC partticle by SHS process were described. The influence of the Al2O3$.$SiC voiume fraction on the mechanical was composite was also discussed. Despite adiabatic temperature was about 2367K, SHs reaction was completed not by itself, but by using pre-heating. Mean particle size of final particle synthesized was 0.73 ${\mu}$m and most of the particle was smaller than 2${\mu}$m. Elastic modulus and tensile strength of the composite increased with increase the volume fraction of reinforcement but, tensile strength depreciated at 30 vol% of reinforcement.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.1-12
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• 2000

This study summarizes the numerical analyses of a Ti alloy deformation under a back extrusion process. Amongst metallic parts in a small propulsion motor case, a Ti-6Al-4V alloy is used extensively. However, the Ti alloy shows a great deal of shear band formation which often leads to a fracture due to a narrow working temperature window. Moreover, the shear band tends to develop over an area where a contact occurs between the hot work piece and the die wall, due to localized cooling. Thus, heating the dies is often required to overcome the deformation localization. Therefore, it becomes necessary to investigate the internal temperature and strain rate distribution during forging process of a Ti alloy. Furthermore, a shear band analysis is peformed using a finite difference scheme and a comparison is made between steel and Ti alloy.

• Korean Journal of Materials Research
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• v.12 no.9
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• pp.691-695
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• 2002

A low temperature anode-supported tubular solid oxide fuel cell was developed. The anode-supported tube was fabricated using extrusion process. Then the electrolyte layer and the cathode layer were coated onto the anode tube by slurry dipping process, subsequently. The anode tube and electrolyte were co-fired at $140^{\circ}C$, and the cathode was sintered at $1200^{\circ}C$. The thickness and gas permeability of the electrolyte depended on the number of coating and the slurry concentration. Anode-supported tube was satisfied with SOFC requirements, related to electrical conductivity, pore structure, and gas diffusion limitations. At operating temperature of $800^{\circ}C$, open circuit voltage of the cell with gastight and dense electrolyte layer was 1.1 V and the cell showed a good performance of 450 mW/$\textrm{cm}^2$.

• Korean Journal of Materials Research
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• v.14 no.5
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• pp.368-373
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• 2004

To improve the conventional cathode-supported tubular solid oxide fuel cell (SOFC) from the viewpoint of low cell power density, expensive fabrication process and high operation temperature, the anode-supported tubular solid oxide fuel cell was investigated. The anode tube of Ni-8mol% $Y_2$O$_3$-stabilized $ZrO_2$ (8YSZ) was manufactured by extrusion process, and, the electrolyte of 8YSZ and the multi-layered cathode of $LaSrMnO_3$(LSM)ILSM-YSZ composite/$LaSrCoFeO_3$ were coated on the surface of the anode tube by slurry dip coating process, subsequently. Their cell performances were examined under gases of humidified hydrogen with 3% water and air. In the thermal cycle condition of heating and cooling rates with $3.33^{\circ}C$/min, the anode-supported tubular cell showed an excellent resistance as compared with the electrolyte-supported planar cell. The optimum hydrogen flow rate was evaluated and the air preheating increased the cell performance due to the increased gas temperature inside the cell. In long-term stability test, the single cell indicated a stable performance of 300 mA/$\textrm{cm}^2$ at 0.85 V for 255 hr.

• Polymer(Korea)
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• v.24 no.3
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• pp.366-373
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• 2000

In this study, the PPS/ABS blend system was investigated in order to collectively identify the relationship among blend morphology, chemical compatibilization and thermal property. ABS resin was chemically modified by the incorporation of maleic anhydride through reactive extrusion for enhanced compatibilization, and PPS, ABS and the modified ABS were blend by a sing twin screw extruder. The effect of chemical modification of ABS on the morphological, mechanical, and thermal properities of the resulting blend was examined. A strong interaction was observed between PPS and MABS by optical microsopy as well as scanning electron microscopy, exhibiting a well-dispersed morphological feature. The PPS/MABS blend showing a single glass transition temperature was observed in dynamic mechanical analysis, demonstrating a pseudo-homogeneous phase morphology induced by chemical compatibilization. PPS/MABS blend also exhibited an enhanced thermal stability and heat distortion temperature compared with modified PPS/ABS blend.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1170-1176
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• 2016

The aim of this study was to investigate the effects of screw speed, moisture content, and die temperature on the physical properties of extruded soy protein isolate. Extrusion conditions were moisture content (20 and 25%) and die temperature (120, 130, and $140^{\circ}C$) at a fixed screw speed of 250 rpm. The other extrusion conditions for screw speed (150, 200, 250, 300, and 330 rpm) were a fixed moisture content and die temperature of 30% and $140^{\circ}C$, respectively. Specific mechanical energy input decreased as die temperature increased from 120 to $140^{\circ}C$, whereas specific mechanical energy input increased as screw speed increased from 150 to 330 rpm. Expansion ratio and specific length increased as die temperature increased. Breaking strength decreased as die temperature increased and moisture content decreased. A lower moisture content resulted in a greater color difference. Integrity index increased as die temperature increased from 120 to $140^{\circ}C$ and moisture content decreased from 25 to 20%. Nitrogen solubility index decreased as screw speed increased from 150 to 330 rpm. Nitrogen solubility index was lowest at $2.83{\pm}0.51%$ as screw speed decreased to 150 rpm. In conclusion, moisture content was a more important factor than die temperature for texturization of soy protein isolate.