• 한국분말재료학회지
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• 제8권1호
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• pp.20-25
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• 2001

Most of mold manufacturing procedures have been automated by the introduction of NC machine tool and CAD/CAM system. But the three-dimensional surface curvature of the mold must be done by hand work of well-skilled workers. Magnetic abrasive polishing powders were investigated for surface polishing for 3D curvature. This study aims to investigate homogeneously distributed hard phase in Fe matrix and strong bonding between Fe-matrix and hard phase. The NbC powder, $B_4C$ powder and $Al_2O_3$ powder were mixed in Fe-matrix respectively. Mixed Fe-hard phase powders were compacted by press and then these were melted by plasma melting. According to SEM, XRD and OM observation, Fe-NbC magnetic abrsive powder had the most homogeneous distribution and strong bonding. As a result of magnetic polishing, the surface roughness before magnetic polishing, 1 ${\mu}m$ $R_{max}$, was reduced to 0.2 ${\mu}m$ $R_{max}$ over the entire inner surface of the tube.

• 한국식생활문화학회지
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• 제24권4호
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• pp.419-425
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• 2009

This study examined the effects of added amounts of shrimp powder on the physical and sensory properties of Jook for elderly foodservice operation. According to the amylograph data, the composite shrimp flour-wheat flour samples increased the gelatinization temperature, with increasing shrimp-flour content; moreover, initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. As the level of shrimp powder in samples increased, L-values decreased, and a-values and b-values increased. In addition, the Jook had higher viscosity and lower spreadability values as the amount of shrimp powder increased. Sensory characteristics, such as nutty taste, color, viscosity, and overall preference increased significantly with the addition of shrimp powder. In conclusion, to enhance the quality of Jook, a 3% addition of shrimp powder would be the most beneficial.

• 한국결정성장학회지
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• 제17권3호
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• pp.128-132
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• 2007

방전플라즈마 소결법을 적용하여 탄화붕소 세라믹스를 제조하여 그 소결 특성, 미세 구조 및 기계적 특성을 평가하였다. 탄화붕소의 소결에 방전플라즈마 소결법을 적용하여 소결 조제의 첨가 없이 전통적인 소결법보다 낮은 온도에서 99% 이상의 완전 치밀화된 소결체를 제작할 수 있었으며, 탄화붕소 분말의 메탄을 세척을 통하여 분말 표면에 형성되어 있는 $B_2O_3$ 상을 사전에 제거함으로써 결정립의 조대화를 방지하여 균일한 미세구조의 형성을 유도할 수 있었으며 결과적으로 탄화붕소 소결체의 기계적 특성을 향상시킬 수 있었다. 특히 파괴인성의 경우 메탄을 세척을 통하여 30% 이상의 물성 향상을 달성하였다.

• 한국식품영양과학회지
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• 제45권5호
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• pp.711-716
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• 2016

기능성 소재로써 새싹인삼을 첨가한 카스텔라 제조 시 최적 첨가 비율을 결정하기 위하여 새싹인삼을 밀가루 대신 0%, 5%, 10%, 15%의 비율로 첨가하여 새싹인삼이 카스텔라의 품질에 미치는 영향을 검토하였다. 새싹인삼을 첨가한 반죽의 비중은 첨가량이 증가할수록 증가하여 새싹인삼이 첨가된 15% 카스텔라가 가장 높게 나타났으며, 카스텔라의 굽기 손실률도 새싹인삼 첨가량이 증가할수록 점차 증가하는 경향을 나타내었다. 반면, 카스텔라의 중량과 높이는 새싹인삼 첨가량이 증가할수록 유의적으로 감소하는 경향을 나타내었다. 카스텔라의 pH는 새싹인삼 첨가량이 증가할수록 감소하였으나, 당도는 새싹인삼 첨가량이 증가할수록 대조군과의 유의차가 없었다. 카스텔라 crust의 L, a, b 값은 새싹인삼 첨가량이 증가할수록 감소하였고, crumb의 L값과 a값도 첨가량이 증가할수록 감소하였지만, b값은 새싹인삼 첨가량이 증가할수록 증가하였다. 카스텔라의 검성과 씹힘성은 대조군보다 증가하여 15% 첨가군에서 가장 높은 값을 나타냈고, 응집성은 첨가량이 증가할수록 낮은 값을 나타내었다. 반면 경도와 탄력성에서는 유의적인 차이를 나타내지 않았다. 관능검사 결과는 카스텔라의 crust, crumb 색, 촉촉함과 향에서는 대조군과 새싹인삼의 첨가군 간에 유의적인 차이는 없었다. 단맛 및 씹힘성은 새싹인삼의 첨가량이 증가할수록 유의적인 차이는 없었다. 전반적인 기호도는 새싹인삼이 5% 첨가된 카스텔라에서 5.30으로 가장 높게 나타났으며 15% 첨가군이 4.33으로 가장 낮게 나타났다. 이상의 연구결과에서 새싹인삼 첨가에 대한 기능적인 측면과 비용을 고려해볼 때 새싹인삼 5%를 첨가한 카스텔라가 가장 좋은 것으로 나타났다.

• 한국식품조리과학회지
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• 제27권6호
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• pp.681-689
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• 2011

Yakkong germinated for 48 h at $23^{\circ}C$(48G), which showed the highest isoflavone content, was prepared with no heat treatment(48G-NH) or with additional heat treatment entailing 20 min boiling(48G-20B) or 15 min roasting(48G-15R). After being ground, each powder was substituted for rice flour by 10, 20, or 30% in rice cookies and compare with the control(100% rice flour cookies). The rice cookies containing 20 or 30% 48G-NH showed the highest crispness in texture and the lowest spreadability. The rice cookies containing 48G-20B and 48G-15R did not show a change in spreadibility, regardless of substitution level. For the rice cookies with 48G-15R, when the substitution level increased to 30%, the crispness decreased and hardness increased. The rice cookies with 48G-20B showed the lowest crispness regardless of substitution level. In terms of color, rice cookies substituted with Yakkong powder showed lower L and higher a* values than the control, however there were no tendencies related to b* value change. In sensory testing, rice cookies substituted with YK-48G had an improved quality, especially in flavor and texture as well as in function. The most acceptable substitution level was 20% of 48G-15R.

• 한국분말재료학회지
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• 제4권2호
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• pp.113-121
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• 1997

The densification of the compacts of Co+32%Cr+20%W+l.5%C, Co+32%Cr+20%W+3.0%C and Co+32%Cr+20%W+4.5%C sintered under $H_2$ gas or vacuum was investigated. The effect of V and B addition on the densification was also investigated. The densification of these compacts were always incomplete regardless of sintering atmosphere, temperature and time. The amounts of oxygen and carbon in compacts sintered in $H_2$ for 3.6ks at 1523K were 0.105~0.160 mass% and 0.33~0.89 mass%, respectively. And those in vacuum were 0.028~0.032% and 0.957~4.08%, respectively. Relative density(Ds) of Co+29%Cr+17%W+3.0%C compact containing 6%V and Co+32%Cr+20%W+2.97%C compact containing 0.03%B were 99 and 100%, respectively, indicating complete densification by solid phase sintering. Victors hardness of sintered compacts containing 6%V or 0.03%B were 632 and 568, showing 50~60% increase in comparison to those without V or B. These results can be explained in terms of oxidation/reduction of oxides and equilibrium pressure of CO in isolated pore, instead of presence of liquid formation and grain boundary separation from pores due to large grain growth.

• Journal of Magnetics
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• 제1권2호
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• pp.75-81
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• 1996

Study on the HDDr Characteristics of Nd16Fe76-xB8Zrx (x=0-2.0) Alloys and the Magnetic Properties of the HDDR Materials Nd16Fe76-xB8Zrx (where x=0-2.0) have been studied to see the effect of Zr addition on HDDR characteristics. A particular emphasis was place upon the anisotropy of the HDDR material. Anisotropy of the HDDR powder material has been evaluated by comparing the remanence values of the aligned sample measured along the aligning direction and the direction perpendicular to it. The HDDR characteristics of the alloys were investigated by means of DAT and TPA. Magnetic chracterisation of the HDDR processed materials was performed using a VSM and a TMA. The magnetic domain structure of the HDDR materials was examined by means of polarised microscope using a solid HDDR processed material. It has veen found that small addition (0.1 at %) of Zr to Nd-Fe-B-type alloy retards thedisproportionatio kinetics of the hydrogenated material. Desorption characteristic of the disproportionated materials has been found not to be affected significantly by the Zr addition. The Zr addition has been found to facilitate size of the powder. As the particle size decreases, the intrinsic coercivity decreases radically, and this is explained in terms of structural damage and/or oxidation caused during mechanical milling. It has also been found that the degree of alignment representing the anisotropic character of the HDDR powder is enhanced with decreasing particle size. Alloys with compositions based on

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.61-66
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• 2006

The objective of this study was to compare the color and microstructure of powder, redness, brownness, and antioxidative activity in extruded ginseng, white ginseng and red ginseng extracts. The colors of extruded dry ginseng powder (moisture content 30%, barrel temperature $110^{\circ}C$, and screw speed 200 rpm) were similar to those of red ginseng. Intact cell wall structure was examined in dried root ginseng at $70^{\circ}C$ (A), white ginseng with skin (D), white ginseng without skin (E), and red ginseng (F) under a scanning electron microscope. The cell wall was not detected in samples B and C (dry ginsengs extruded with 25% and 30% moisture contents, respectively). Intact starch granules were detected in samples A, D, and E under a scanning electron microscope. Melted starch granules were detected in samples B, C, and F. Colors (L, a, b) of 50% EtOH extracts were similar in samples C and F. Browniness and redness of extracts were high in extruded dry ginseng and red ginseng extracts. Extruded dry ginseng (B) showed higher electron donation ability and phenolic content than the other samples.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1084-1085
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• 2006

We studied formation of nanostructured $TiB_2$-Cu composites under shock wave conditions. We investigated the influence of preliminary mechanical activation (MA) of Ti-B-Cu powder mixtures on the peculiarities of the reaction between Ti and B under shock wave. In the MA-ed mixture the reaction proceeded completely while in the non-activated mixture the reagents remained along with the product . titanium diboride. The size of titanium diboride particles in the central part of the compact was 100-300 nm.

• 한국조리학회지
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• 제22권3호
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• pp.108-120
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• 2016

본 연구에서는 복숭아 분말의 첨가량을 달리하여 젤리를 제조한 후 젤리의 물리화학적 품질특성(pH, 색도, 외관색상, 경도)과 소비자 기호도(색, 향미, 씹힘성, 맛, 전체적 기호도)를 비교 분석하였다. 젤리의 pH는 증가하였다(p<0.001). 명도를 나타내는 $L^*$값은 복숭아 분말의 첨가량이 증가할수록 유의적으로 감소하였고(p<0.001), 적색도를 나타내는 $a^*$값과 황색도를 나타내는 $b^*$값은 유의적으로 증가하였다(p<0.001). 복숭아 분말 첨가 젤리의 DPPH 라디칼 소거능에 대한 결과는 복숭아 분말 첨가량이 많을수록 DPPH 라디칼 소거능이 증가하였다. 소비자 검사결과, 15% 첨가군이 모든 평가항목에서 유의적으로 높은 평가를 받아 젤리의 관능적 품질을 최대한 유지하면서 복숭아 분말의 기능적 이점을 최대한 활용하기 위한 젤리의 최적첨가 농도는 15%가 가장 적합한 것으로 판단된다.