• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.193-194
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• 2006

A solid freeform fabrication (SFF) system using selective laser sintering (SLS) is currently recognized as a leading process and SLS extends the applications to machinery and automobiles due to the variousmaterials employed. In order to develop a more elaborate and rapid system for fabricating large objects compared to existing SLS, this study employs a new selective dual-laser sintering (SDLS) process. Also, this paper will address development of an SFF system which employs the dual laser system and the unique scanning device. Experiments were performed to evaluate the effect of a scanning path and fabrication parameters on sintering process and to fabricate the various 3D objects using polymer powder.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.92-100
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• 2013

This study investigated the quality and antioxidative properties of a Korean fried rice cake, Gaeseong-Juak (doughnut of waxy rice) added with Prunus yedoensis Matsumura (PYM) extract, vitamin C and BHT. Gaeseong-Juak was prepared by adding PYM extract at 0, 0.5, 1, and 2% of waxy rice powder. The moisture contents of Gaeseong-juak added with PYM extract varied between 17.50% and 21.70%. Among the samples, the lowest moisture content was 2% Gaeseong-juak added with PYM extract. The contents of the samples obtained from crude protein, crude fat, crude ash were 4.47~4.73, 11.15~12.50, and 0.73~0.82%, respectively. The as the content of PYM extract increased, L-values significantly decreased while a-value and b-value significantly increased (p<0.001). The texture profile analysis of the Gaeseong-Juak was not significantly different at the samples. In the sensory test, the sample containing 0.5% PYM extract obtained good scores. The antioxidative effect of the Gaeseong-Juak significantly increased as the addition level increased, compared to the original Gaeseong-Juak (p<0.001). From these results, we suggest that PYM is a good ingredient for increasing the consumer acceptability and the functionality of Gaeseong-Juak.

• Korean journal of food and cookery science
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• v.31 no.3
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• pp.335-343
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• 2015

The aim of this investigation was to examine the antioxidation, physicochemical, and sensory activity of a Korean steamed-rice cake, Sulgidduk, fortified with water extracts from Moringa oleifera (M. oleifera) leaf. M. oleifera leaf extracts were added to rice powder at rations of 0.1%, 1% and 10%. To examine antioxidation properties, the scavenging activities of DPPH radicals, hydroxyl radicals, ABTS+ radicals, and ferric ion reducing antioxidant power were investigated. M. oleifera extracts significantly increased the antioxidation activities of Sulgidduk in a dose dependent manner (p<0.05). Physicochemical characteristics were measured by proximate composition, color, texture profile analysis, and sensory evaluations. As the concentration of M. oleifera leaf extracts increased, L-values and a-values significantly decreased while b-values increased. Texture profile analysis demonstrated that the control groups showed significantly higher values for hardness, cohesiveness, chewiness, and adhesiveness as compared with groups containing M. oleifera leaf extract (p<0.05). In the sensory evaluation, the sample containing 0.1% of M. oleifera leaf extract obtained the best results in overall preference. Taken together, these results suggest that M. oleifera leaf may have the potential to increase the consumer acceptability and the functionality of Sulgidduk.

• Progress in Superconductivity
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• v.7 no.2
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• pp.174-178
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• 2006

For the practical application on SCFCL, Bi2212 tubes were fabricated by Centrifugal Forming Process (CFP) in terms of many different processing parameters. Typical sizes of tubes were 60, 150 mm in length and 2.5, 3.5, 4.8 mm in thickness. Initially powder was melted by induction heating. The optimum range of melting temperatures and preheating temperature were $1100^{\circ}C$ and $500^{\circ}C$ for 30min respectively. The nominal mold rotating speed was around 1000 RPM. A tube was annealed at $840^{\circ}C$ for 80 hours in oxygen atmosphere. The tube of 50mm x 70mm x 2.5mm, rotated with 1000 RPM showed $I_c=890\;A\;and\;T_c=80$. It was found that the tube processed with faster rate of mold rotation speed, thinner tube thickness and shorter tube length shows better electric characteristics as compared with the tube normally processed. In order to study the uniformity heat and fluid flow analysis tool was adopted along tube.

• Food Quality and Culture
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• v.3 no.1
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• pp.6-10
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• 2009

This study examined the effects of adding Pleurotus ostreatus, Agaricus bisporus and Flammulina velutipes on the quality characteristics of cookies and multiple purposes of wheat powders. The water content, crude protein content, mineral content, color value and sensory evaluation of mushroom cookies and multiple purposes of wheat powders were measured. In the case of cookies, the water content was 1.10-1.24% and crude protein content was 8.20-9.80%. General preferences, such as appearance, color, taste and texture, increased when mushroom was added to the cookies, especially flavor, which showed a much higher preference. In the studies where mushroom was added to wheat powders, the water content was 0.57-0.92% and crude protein content was 11.90-12.80%. The addition of mushroom to both of the cookies and multiple purposes of wheat powders resulted in a remarkable increase in the mineral content, especially Fe, K. In addition, an increase in the amount of added mushrooms resulted in an increase in the hunter L and a values; however, this also resulted in a decrease in the b value.

• Journal of the Korean Society of Food Culture
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• v.33 no.2
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• pp.133-141
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• 2018

This study investigated the quality characteristics and antioxidant activities of Makgeolli (a traditional Korean rice wine) made with Etteum bell flower root (0.5, 1, 1.5, and 2% with steamed rice) during fermentation. The pH values of Makgeolli with Etteum bell flower root powder decreased after 3 days of fermentation and then increased after 5 days of fermentation. Sugar content decreased after 3 days of fermentation. Color evaluation showed the L values of these drinks decreased during fermentation, whereas a and b values both increased. The alcohol content of Makgeolli increased after fermentation, reaching a maximum concentration of 7.90-8.07% by the end of fermentation. Total phenolic compound contents and DPPH radical scavenging activities increased as the ratio of Etteum bell flower root increased. Sensory scores of Makgeolli fermented with 1.5% Etteum bell flower root ware greater than those of Makgeolli prepared by other treatments. Therefore, Makgeolli added with 1.5% Etteum bell flower root added considered to be the most suitable for manufacturing.

• The Korean Journal of Food And Nutrition
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• v.24 no.2
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• pp.173-179
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• 2011

The principal objective of this study was to develop processed food with the effect of extract from Angelica gigas Nakai by assessing the quality characteristics of cookies. Cookie samples were prepared with shredded extract from Angelica gigas Nakai at varied levels of 0, 1, 3, and 5%. The pH of dough decreased significantly with the added extract from Angelica gigas Nakai and the density increased significantly in the 5% added group(p<0.05). The spread factor decreased significantly as the added extract from Angelica gigas Nakai increased(p<0.05). The Hunter color's L value in cookies significantly decreased and the a, b values in cookies increased(p<0.05). The hardness of cookies significantly increased added extract from Angelica gigas Nakai increased(p<0.05). The acid value and peroxide value were lower in added Angelica gigas Nakai extract groups than in the control group as the storage period of cookies passed. The results of sensory characteristics demonstrated that 1% added Angelica gigas Nakai extract showed the highest degree of preference among all the items of added Angelica gigas Nakai extract(color, odor, taste, hardness, crispness and overall quality) and the added Angelica gigas Nakai extract indicated possibilities for developments of Angelica gigas Nakai extract cookies.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.495-501
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• 2020

In this study, zirconium fumarate of metal-organic framework (MOF-801) was solvothermally synthesized at 130 ℃ and characterized through powder X-ray diffraction (PXRD) analyses and porosity measurements from N₂ sorption isotherms at 77 K. The ability of MOF-801 to act as an adsorbent for the phosphate removal from aqueous solutions at 25 ℃ was investigated. The phosphate removal efficiency (PRE) obtained by 0.05 g/L adsorbent dose at an initial phosphate concentration of 60 ppm after 3 h was 72.47%, whereas at 5 and 20 ppm, the PRE was determined to be 100% and 89.88%, respectively, after 30 min for the same adsorbent dose. Brunauer-Emmett-Teller (BET) surface area and pore volume of the bare MOF-801 sample were 478.25 ㎡/g and 0.52 ㎤/g, respectively, whereas after phosphate adsorption (at an initial concentration of 60 ppm, 3 h), the BET surface area and pore volume were reduced to 331.66 ㎡/g and 0.39 ㎤/g, respectively. The experimental data of kinetic (measured at initial concentrations of 5, 20 and 60 ppm) and isotherm measurements followed the pseudo-second-order kinetic equation and the Freundlich isotherm model, respectively. This study demonstrates that MOF-801 is a promising material for the removal of phosphate from aqueous solutions.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.200-202
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• 1987

Sintered CdS films on glass substrate with low electrical resistivity and high optical transmittance have been prepared by coating and sintering method. All-polycrystalline CdS/CdTe solar cells with different microstructure and properties of CdTe layer were fabricated by coating a number of CdTe slurries, which consisted of Cd and Te powders, an appropriate amount of propylene glycol and 2 or 7.5 w/o $CdC1_2$, on the sintered CdS films and by sintering the glass-CdS-(Cd+Te) composites at various temperature. To explore the dependence of the solar efficiency on the preparation conditions of the CdTe layer, Cd powder with an average particle size of $0.3{\mu}m$ or $5{\mu}m$ was prepared. The use of Cd with finer particles forms more dense or uniform microstructure of the nuclear of CdTe during the heating. Therefore the use of Cd with finer particles improves the efficiency of the sintered CdS/CdTe solar cell by improving the microstructure of sintered CdTe layer. But the difference of solar efficiency by varing a particle size of Cd is decreased with increasing amount of $CdC1_2$ in the (Cd+Te) layer. All-polycrystalline CdS/CdTe solar cells with an efficiency of 10.2% under solar irradiation have been fabricated using a Cd with finer particles.

• Transactions on Electrical and Electronic Materials
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• v.5 no.2
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• pp.55-60
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• 2004

High-temperature Superconductor(HTS) tubes were fabricated in terms of different chemical compositions and various SrSO$_4$additions by centrifugal forming method. For powder melting by induction the optimum range of melting temperatures and preheating temperature were 1050$^{\circ}C$, 1100$^{\circ}C$ and 550$^{\circ}C$ for 30 min, respectively. The mould rotating speed was 1000 rpm. A tube was annealed at 840$^{\circ}C$ for 72 hours in oxygen atmosphere. The plates like grains more than 20 $\mu\textrm{m}$ were well developed along the rotating direction of mould regardless of initial chemical compositions and the amounts of SrSO$_4$in Bi2212. The specimen with Bi2212 composition exhibited T$\_$c/ of 83 K, while the specimens fabricated with other compositions are lower than 60 K. The measured I$\_$c/ and J$\_$c/ at 77 K(B = 0 T) in Bi2212 with 7 % SrSO$_4$ composition were about 680 A and 380 A/$\textrm{cm}^2$.