• 동아시아식생활학회지
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• 제26권1호
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• pp.55-62
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• 2016

As interest in health has recently increased, many researchers have investigated the utilization of functional foods by confectioneries and bakeries. However, research on loaf bread containing beets has not been conducted. To investigate the optimal ratio of beet in loaf bread containing beet powder, characteristics of loaf bread according to 2%(B2), 4%(B4), and 6%(B6) beet powder per wheat flour were examined. The experimental results were as follows. Fermentation rate was reduced as content of beet powder increased compared with the control, whereas pH levels of dough and loaf bread significantly increased as content of beet powder increased. As content of beet powder increased, volume of loaf bread decreased, whereas specific volume increased. There was no significant difference in volume of loaf bread between the samples. As far as color changes are concerned, as content of beet powder increased, L value decreased, whereas a and b values increased with significant differences between the samples. Characteristics were examined by sensory evaluation of loaf bread containing beet powder. Color of inner texture and peel color of loaf bread significantly increased as content of beet powder increased. Size of air pores was largest in B4, and there was no significant difference in the uniformity of loaf bread between the control and experiment groups. As content of beet powder increased, rigidity of bread was reduced. Control showed the highest elasticity, whereas moisture level was highest in B2 with no significant differences between the samples. The flavor of beet was stronger as content of beet powder increased. In the preference test, B4 showed the highest preference scores for texture, flavor, taste, and overall likeness but not appearance. The experimental results showed that B4 among all control and experimental groups had the most suitable baking characteristics and an optimum content of beet powder. Therefore, B4 can be considered as the most appropriate for making loaf bread containing 4% beet powder in terms of physical and sensory characteristics. This is a new product that satisfies overall sensory preferences and has improved functionality.

• 자원리싸이클링
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• 제26권1호
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• pp.16-21
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• 2017

본 연구는 SiC 결정 성장을 위한 원료 분말 합성법에 관한 것이다. ${\beta}-SiC$ 분말들은 높은 온도 조건(>$1400^{\circ}C$)에서 실리콘 분말과 탄소 분말의 반응에 의해서 합성 된다. 이 반응은 진공 상태(또는 Ar 가스 분위기)에서 실리콘+탄소 혼합물이 반응하고 다결정의 SiC 분말을 형성하기 충분한 횟수를 거쳐 그라파이트 도가니 안에서 진행된다. 최종 결과물의 특성들은 X-ray 회절, SEM/EDS, 입도 분석 및 ICP-OES을 통해 분석되었다. 또한, 최종 결과물의 순도는 the Korean Standard KS L 1612에 의거해서 분석했다.

• 산업식품공학
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• 제15권1호
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• pp.34-40
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• 2011

As an attempt to develop a value-added food product, purple sweet potato powder was added in a model system of steamed bread as a healthy food ingredient and physicochemical properties such as moisture content, specific volume, spread ratio, color, texture as well as consumer preferences on the attributes such as uniformity, color, flavor, elasticity, chewiness, taste, and overall preference were evaluated. Moisture content ranged from 44.16 to 44.55% (wet basis) and appeared independent on the level of purple sweet potato (PSP) powder incorporation. As a result of the addition of PSP powder, the specific volume of steamed bread decreased from 3.22 to 2.55 mL/g, and value of 4.5% sample was significantly lower than other samples (p<0.05). On the other hand, spread ratio ranged from 2.01 to 2.53, and appeared to decrease as the PSP powder concentration increased (p<0.05), indicating a significant improvement. Lightness $(L^*)$ decreased significantly as the PSP powder content increased (p<0.05) for both dough and skin of the steamed bread. In addition, an increasing trend in redness ($a^*$-value) and a decreasing trend in yellowness ($b^*$-value) were noticed. Firmness increased significantly with the addition of PSP powder regardless of concentration (p <0.05); however, firmness was not significantly different among samples containing 1.5-4.5% PSP powder (p>0.05). Consumer acceptance test indicated that incorporation of 3% PSP powder in the formulation of steamed breads would be recommended.

• 한국분말재료학회지
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• 제6권3호
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• pp.215-223
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• 1999

The synthesis of $Ni_5Si_2,\;Ni_2Si$ and NiSi has been investigated by mechanical alloying (MA) of Ni-27.9at%Si, Ni-33.3at%Si and Ni-50.0at%Si powder mixtures. As-received and premilled elemental powders were subjected to MA. The as-received Ni powder was spherical and the mean particle size 48.8$\mu$m, whereas the premilled Ni powder was flaky and the mean particle diameter and thickness were found to be 125 and 5$\mu$m, respectively. The mean surface area of the premilled Mi powder particle was 3.5 times as large as that of the as-received Ni powder particle. The as-received Si powder was was 10.0$\mu$m. Self-propagating high-temperature synthesis (SHS) reaction, followed by a slow reaction (a solid state diffusion), was observed to produce each Ni silicide during MA of the as-received elemental powders. In other word , the reactants and product coexisted for a long period of MA of time. Only SHS reaction was, however, observed to produce each Ni silicide during MA of the premilled elemental powders, indicating that each Ni sillicide formed rather abruptly at a short period of MA time. The mechanisms and reaction rates for the formation of the Ni silicides appeared to be influenced by the elemental powder particle size and shape as well as the heat of formation of the products $(Ni_5Si_2$longrightarrow-43.1kJ/mol.at., $Ni_2Si$$\rightarrow$-47.6kJ/mol.at.).

• 한국세라믹학회지
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• 제33권11호
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• pp.1285-1291
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• 1996

Using Cr2O3 Al and graphite powders as starting materials Cr3C2 was synthesized by combustion synthesis process according to the following reaction : 3Cr3C2 +4C+6Allongrightarrow2Cr3C2 +3Al2O3. The synthesis was conducted at 2 atm in an argon atmosphere. in this study main-product was monolithic phase of Cr3C2 /Cr7C3 mixture and sub-product was slag state of $\alpha$-Al2O3. Single phase of Cr3C2 was obtained when crushed main-product was heat-treated at 120$0^{\circ}C$ for 3h in vacuum state with addition of 2.5wt% C. The obtained Cr3C2 powder can be used as plasma-arc deposit material because the flowability index of powder with the size of 9-50${\mu}{\textrm}{m}$ was 66.

• 한국세라믹학회지
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• 제48권1호
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• pp.106-109
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• 2011

In order to fabricate 8YSZ thick film by silk screen printing, YSZ(yttria-stabilized zirconia) commercial powder was used as starting materials. Paste for screen printing was made by mixing 8YSZ powder and organic vehicles. 8YSZ thick film was formed on $Al_2O_3$ substrate. The crystal structure, and microstructure were investigated. Grain size of 8YSZ was increased with increasing calcination temperature and rapid grain growth was shown after calcination at $1300^{\circ}C$. Microstructure showed the mixture of large and small grain size after $1400^{\circ}C$ sintering. Shrinkage rate of 8YSZ thick film sintered at $1400^{\circ}C$ was more than 40%.

• Journal of Ginseng Research
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• 제10권2호
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• pp.218-232
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• 1986

In this review quality improvement, new products and processing of ginseng are discussed. Ginseng products are generally classified into two types; the dried product without significant change in original shape of fresh ginseng and various processed ginseng products in liquid or solid types prepared by addition of either ginseng extract of ground powder. The dried ginsengs are generally made 4 years old fresh ginseng roots for production of white ginseng and 6 years old ones for red ginseng. The processed ginseng products, such as ginseng drinks, extracts, teas, powders, capsules or tablets are prepared by addition of extract or powder of the ginseng roots which contain relatively high amount of saponin. At present, more than 200 items of 40 types of products are commercially available in over 70 countries in the world, Since consummers preference on the quality of ginseng products as an health food differs with their cultural background of each country, new products development and quality improvement should be investigated with concerning the particular preference of the consummers of various country. It has been generally found that the Orientals has higher product acceptance on strong ginseng flavor while the Westerners generally prefers the products having mild ginseng odor and taste. Recently consummers are asking for supplemented type of ginseng products with various medical herbs and vital materials instead of ginseng alone. Therefore future work on product development should be emphasized to meet the consummers demand and preference.

• 한국세라믹학회지
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• 제43권8호
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• pp.472-478
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• 2006

The effect of compositional and processing variables on a nitriding reaction of silicon powder compact and subsequent post sintering of RBSN (Reaction-Bonded Silicon Nitride) was investigated. The addition of a nitriding agent enhanced nitridation rate substantially at low temperatures, while the formation of a liquid phase between the nitriding agent and the sintering additives at a high temperature caused a negative catalyst effect resulting in a decreased nitridation rate. A liquid phase formed by solely an additive, however, was found to have no effect on nitridation for the additive amount used in this research. The original site of a decomposing pore former was loosely filled by a reaction product ($Si_3N_4$), which provided a specimen with nitriding gas passage. For SRBSN (Sintered RBSN) specimens of high porosity, only a marginal dimensional change was measured after post sintering. Its engineering implication for near-net shaping ability is discussed.

• 한국표면공학회지
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• 제42권4호
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• pp.186-189
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• 2009

In this study, niobium powder was made from potassium heptafluoroniobite($K_2NbF_7$) using sodium(Na) as a reductant and KCl, KF as a diluent based on the hunter metallothermic reduction method. The excesses of reductant were varied from 0%, 3%, 5% and 7%. When 7% excess of sodium was used, the un-reacted sodium remained in the reacted product. The niobium powder has been achieved by reducing 50 g of $K_2NbF_7$ with 5% sodium excess in a charge at a reduction temperature of $850^{\circ}C$. The proportion of fine fraction decreased appreciably and the yield of niobium powder improved from 65% to 85% with the increase of sodium excess. The average particle size of niobium powder is improved from 0.2 microns to 0.3 microns in the 5% excess sodium.

• 한국세라믹학회지
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• 제44권3호
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• pp.152-156
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• 2007

Tungsten carbide powder was synthesized by SHS (self-propagating high-temperature synthesis). Except $WO_{3}$, each concentration of raw material ($WO_{3},\;Mg,\;NaCl,\;Na_{2}CO_{3},\;C$) was investigated. Final product was characterized by XRD and SEM. X-ray data demonstrated that the $NaCl+Na_{2}CO_{3}$ combined mixture has superiority in the WC formation process. Single phase and submicrometer WC powder was synthesized at the temperature below $1600^{\circ}C$. The role of sodium salts in combustion process was discussed, and chemical mechanism of WC formation was proposed. WC powder prepared by salt-assisted combustion synthesis has a size $0.2{\sim}3\;{\mu}m$ and low agglomeration degree.