• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.282-285
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• 2009

Selective laser sintering (SLS) is a fast growing process of rapid production fur metallic based parts. To restore damaged mold surface using SLS, single layer experiments of $20{\mu}m$ Fe-Cr powder was performed under various heat input. Process window of $20{\mu}m$ Fe-Cr powder provided feasible process parameters for the smooth regular surface. To estimate coherence between melted powder and basematal, tendency of hardness distribution has been observed. Hardness of melted zone and remelted zone was diversified from 5GPa to 6.5GPa. It is over 2 times compared of hardness of basemetal. Average surface roughness of each direction on surface of melted powder was measured. Experimental results show that the mold restoring process using SLS can be successfully applied in the mold repair industry.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.250-256
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• 2011

The findings of this study into the quality of fresh pasta noodles containing different amounts of the lyophilized citrus peel powder are as follows. The higher the amount of the citrus peel powder in the pasta, the higher was its WRC. The Hunter's values, whether L, a, and b all increased in both cooked and raw noodles. The higher the amount of the citrus peel powder, the less the level of tensions and the lower the setback values. These results suggest that the citrus peel powder might have a controlling effect on retrogradation. As for the characteristics of cooked pasta noodles, the weight decreased; the volume increased; and the moisture absorptive power also increased. The tasters' preferences were in the following order: 3%>0%>5%>7%>1%. In other words, a citrus peel powder content of 3~5% appears to be most appropriate.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.257.2-257
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• 2001

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.174-174
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• 2002

• Journal of the East Asian Society of Dietary Life
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• v.20 no.4
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• pp.589-595
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• 2010

The purpose of this study was to investigate the practical application and optimum conditions for adding functional dropwort, which is rich in physiological activity to Sulgidduk, toward developing dropwort-added dduk as a healthy food. To this end, samples of Sulgidduk with 0, 1, 3, 5 and 7% added dropwort powder were prepared, stored for 2 days at $20^{\circ}C$, after which the water content, chromaticity, and mechanical and sensory quality characteristics were measured. The results were as follows. The water content of nonglutinous rice powder and dropwort powder used for dropwort-added Sulgidduk was 41.73% and 3.5%, respectively. The water content decreased with increasing amounts of dropwort powder the group with 7% added dropwort powder was 33.88%, the lowest. For chromaticity, the L value decreased with increasing amount of dropwort powder with significant differences between groups with different added amounts (p<0.001). The a and b values increased with increasing amount of dropwort powder while they were 7.21 and 29.22, respectively, in the 7% dropwort powder-added group with significant differences between samples (p<0.001). For mechanical quality characteristics hardness decreased with increasing of amount of dropwort powder with significant differences between samples (p<0.001). There was no difference between samples in cohesiveness and springiness. Gumminess increased with increasing amount of dropwort powder with significant differences between samples (p<0.05). Chewiness and adhesiveness had a tendency to decrease with increasing amounts of dropwort powder. Overall acceptability was in the order of 3%, 5%, 1%, 7%, and 0% dropwort powder-added groups. Overall, for dropwort powder added Sulgidduk, the quality of flavor, color and taste was acceptable, compared to other powder-added groups. The 3% dropwort powder-added group was highly rated in general preference making it most desirable for making dropwort powder-added Sulgidduk.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.529-537
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• 2010

To evaluate the effect of pomegranate powder on rice dasik, pomegranate dasik was prepared after supplementation with pomegranate powder(0, 5, 10, 15 and 20%(all w/w)). The proximate components of pomegranate powder was 9.98% moisture content, 1.54% crude protein, 3.50% crude lipid, 16.00% crude fiber and 4.84% crude ash. The moisture content of samples showed no significant difference. The pH values in samples with the pomegranate powder were lower than that of the control group and pH values were significantly decreased with increased pomegranate powder(p<0.05). The lightness(L-value) was significantly decreased as pomegranate powder increased(p<0.05). Redness(a-value) was increased as pomegranate powder increased until 10%. However redness was decreased in samples with more than 15% pomegranate powder. The yellowness(b-value) decreased significantly with the amount of increased pomegranate powder(p<0.05). In the mechanical evaluation, hardness in the groups with pomegranate powder decreased significantly (p<0.05). Adhesiveness was decreased with increased pomegranate powder. Springness in groups with more than 15% pomegranate powder was higher than that of the control group. Cohesiveness and chewiness in groups with pomegranate powder were higher than that of the control group. But no significant difference in gumminess among groups was found. The intensity of color, odor and astringency of dasik with pomegranate powder significantly increased as the amount of supplementation increased(p<0.05). And the preference of taste and overall acceptability significantly increased as pomegranate powder increased(p<0.05). In conclusion, rice disik with 5% of pomegranate powder would be most proper in taste and overall acceptability.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.759-768
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• 2010

To improve the sensory acceptability of Kochujang with added Meju powder, Kochujang was prepared with added raw soy powder and roasted soy powder were added instead of Meju powder. These Kochujang were fermented for 45 days at $25{\pm}3^{\circ}C$ and examined for changes in their physicochemical properties and sensory characteristics. Results were as follows. In the moisture content and acidity of Kochujang, the group with added Meju powder was the highest. There were no significant differences in the lightness (L value), although the group with added with Meju powder and raw soy powder were decreased in lightness over days of storage. For redness (a value), the group with added raw soy powder was the highest, and the group with added raw soy powder was decreased with increasing storage days. For yellowness (b value), the group with added roasted soy powder was the highest, and there was no significant difference over storage days. The reducing sugar content of Kochjang to which roasted soy powder was added was the highest, and the amino-nitrogen contents of Kochjang to which Meju powder was added was the highest In sensory evaluation, the Kochjang with added roasted soy powder had the best score in taste and overall acceptability. Therefore, these results suggest that roasted soy powder can be applied to Kochjang for enhanced sensory preference.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.160-166
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• 2007

Response surface methodology (RSM) was used for the optimization of the baking process of cookies made with onion powders (onion cookie). Experiments were carried out according to a central composite design, selecting onion powder content $(1.15{\sim}8.86%)$ and baking temperature $(155.9{\sim}184.1^{\circ}C)$ as independent variables and pH, titratable acidity, moisture content, density, spread factor, CIE color parameters $(L^{\ast}-$, $a^{\ast}-$, and $b^{\ast}-values)$, and hardness as response variables. pH decreased with increasing amount of onion powder and baking temperature. Moisture content also decreased as the baking temperature increased. $L^{\ast}-$ and $b^{\ast}-values$ decreased but $a^{\ast}-values$ increased with increasing onion content and baking temperature. Most polynomial models developed by RSM were highly effective to describe the relationships between the studied factors and the responses. Overall optimization, conducted by overlaying the contour plots under investigation, was able to point out the optimal range of the independent variables within which the six responses were simultaneously optimized. The point chosen as representative of this optimal region corresponded to 4.01% onion powder content and $161.84^{\circ}C$ baking temperature. The predicted dependent or response values in the optimal region were: pH＝6.87, moisture content＝2.77%, $L^{\ast}-value＝68.45$, $a^{\ast}-value＝1.98$, $b^{\ast}-value＝34.64$, and spread factor＝9.41.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1205-1206
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• 2006

Dispersion-strengthened copper with $TiB_2$ was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at $650^{\circ}C$ for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.36-41
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• 2017

The effects of $MgB_4$ addition on the superconducting properties and the microstructure of in situ processed $MgB_2$ bulk superconductors were studied. $MgB_4$ powder of 1-20 wt.% was mixed with (Mg + 2B) powder and then pressed into pellets. The pellets of (Mg + 2B + $xMgB_4$) were heat-treated at $650^{\circ}C$ for 1 h in flowing argon. The powder X-ray diffraction (XRD) analysis for the heat-treated samples showed that the major formed phase in all samples was $MgB_2$ and the minor phases were $MgB_4$ and MgO. The full width at half maximum (FWHM) values showed that the grain size of $MgB_2$ decreased as the amount of $MgB_4$ addition increased. $MgB_4$ particles included in a $MgB_2$ matrix is considered to suppress the grain growth of $MgB_2$. The onset temperatures ($T_{c,onset}$) of $MgB_2$ with $MgB_4$ addition (0-10 wt.%) was between 37-38 K. The 20 wt.% $MgB_4$ addition slightly reduced the $T_{c,onset}$ of $MgB_2$ to 36.5 K. This result indicates that $MgB_4$ addition did not influence the superconducting transition temperature ($T_c$) of $MgB_2$ significantly. On the other hand, the small additions of 1-5 wt.% $MgB_4$ increased the critical current density ($J_c$) of $MgB_2$. The $J_c$ enhancement by $MgB_4$ addition is attributed not only to the grain size refinement but also to the possible flux pinning of $MgB_4$ particles dispersed in a $MgB_2$ matrix.