• 한국결정학회지
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• 제15권1호
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• pp.44-50
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• 2004

Spinel structured lithium managanese oxide $(LiMn_2O_4)$ powder with well defined facetted morphology was prepared by precipitation-evaporation method. {111}, {110}, and {100} planes are mainly observed in the $LiMn_2O_4$ powder. And powder shape of tetradecahedron and octahedron was observed depending on the calcinations temperature. The observed powder morphology observed seemed to be related to the nonstoichiometry of the oxygen in the $LiMn_2O_4$ spinel structure. Oxygen nonstoichiometry might be responsible for the Jahn-teller effect and structure transition which in turn affects the surface energy of the {111}, {110}, and {100} planes. Powder shape transition from tetradecahedron to octahedron seemed to be related to the surface energy of the {111}, {110}, and {100} planes with oxygen nonstoichiometry.

• 한국세라믹학회지
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• 제47권5호
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• pp.419-425
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• 2010

In order to examine the P.H.C pile raw material using glass forming ceramic. The used materials is ordinary portland cement, waste TFT-LCD glass powder and reactive agent(Ca$(OH)_2$). The first experiment is characteristics analysis of the waste TFT-LCD glass powder, For the second experiment is mortar and concrete compressive strength for using of the concrete file raw material for waste TFT-LCD glass powder. The results of experiment showed that the substitution ratio of 10% waste TFT-LCD glass powder and 1% reactive agent(Ca$(OH)_2$) was excellent at a point of view for the physical characteristic. The study's most important finding is that the recycling of waste TFT-LCD glass powder.

• 한국조리학회지
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• 제21권6호
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• pp.133-146
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• 2015

본 연구는 아사이베리 분말을 첨가한 양갱의 품질특성과 항산화 효과의 측정 및 관능평가를 실시하였다. 아사이베리 분말을 첨가한 양갱의 수분함량은 아사이베리 분말 첨가비율의 증가에 따라 높아졌다. pH와 당도는 아사이베리 분말의 첨가비율이 높아질수록 낮아졌다. 색도는 아사이베리 분말의 첨가비율이 높아질수록 L값과 b값은 낮아졌고, a값은 높아졌다. 조직감은 아사이베리 분말의 첨가비율이 높아질수록 경도, 검성, 응집성, 씹힘성이 낮아졌고, 탄력성은 유의성이 나타나지 않았다. 아사이베리 분말 첨가 양갱의 총 페놀성 화합물 함량과 DPPH 라디컬 소거능은 아사이베리 분말의 첨가비율의 증가에 따라 유의적으로 높아졌다. 아사이베리 분말 첨가 양갱의 관능평가 결과는 아사이베리 분말 4% 첨가구가 맛과 전반적인 기호도에서 우수한 기호도를 나타내었고, 다른 관능 기호도 항목에서도 비교적 양호한 점수를 나타내었다. 이상의 결과들을 고려하였을 때, 양갱의 제조 시에 아사이베리 분말을 첨가하는 것은 양갱의 항산화 효과와 관능 기호도 상승효과를 꾀할 수 있을 것으로 판단되며, 백앙금량 대비 4%의 아사이베리 분말을 첨가하는 것이 항산화 효과 및 관능 기호도 측면에서 가장 적합할 것으로 판단된다.

• 한국식생활문화학회지
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• 제33권1호
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• pp.55-61
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• 2018

This study examined the quality of bread made from a wheat flour, oat powder, and wild carrot powder mixture. The lightness and redness values decreased with increasing amount of wild carrot powder addition, while the yellowness was increased significantly. In a sample of wild carrot powder addition, the total volume was lower than the control. The texture profile analysis of oat bread, such as hardness, gumminess and cohesiveness decreased significantly with increasing amount of wild carrot powder addition. In the case of springiness, the value was not significant. The sensory evaluation of oat bread was significantly different in all analyses. Oat bread (BCB2.0) containing 2.0% (w/w) wild carrot powder showed the highest value in the four sensory evaluation items. Therefore, the 2.0% (w/w) addition of wild carrot powder addition was appropriate. An analysis of the physicochemical active component and DPPH scavenging activity of oat bread revealed a higher total flavonoid and total polyphenol content than normal bread. The DPPH scavenging activity was also 20.3% compared to the wild carrot powder. The availability of wild carrot powder in oat bread could be identified.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권4호
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• pp.153-158
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• 2003

This thesis deal with ferroelectric and ferromagnetic materials. PZT/Ferrite ceramics were made by the making process using PZT powder and garnet ferrite powder. PZT and ferrite are mixed as much 90%-10%, 50%-50%, and so on. After making samples, we are polishing samples until thickness is 0.1~0.2mm. We measured all kinds of samples in room temperature and applied magnetic field from -4500 to 4500 Oersted and conducted test of magnetical and electrical measurement using VSM and lpC resolution electrometer calibrated with RT66A pulsed tester. From this measurement, we can calculate tunability of these samples using C value obtained from P-E loop. As a result, it was able to measure magnetic characteristic when two matter had each other component ratio, and it was compound. However, it confirmed the possibility that was able to have ferroelectric characteristic with you in PZT 90% and ferrite 10%. Therefore, If this thing comes for PZT 50% and ferrite 50% have ferroelectric characteristic as him in a compound sample ore, can use this in an oscillator, supersonic waves detector in addition to a piezoelectric element. It may contribute to multipurpose of an element and demands such as a miniaturization of equipment, efficiency, reduce of a price which can use a characteristic of two components.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.85-88
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• 2005

The stone powder sludge occurred at aggregate production process is classified the specified waste, so it is disposed by appropriate method. But the problems of the shortage of the disposal-site, the environment pollution, and the increase of disposal cost can be occurred in handling process, therefore the stone powder sludge is required the development of recycling technique. The stone powder sludge includes SiO2 of about $63\%$. This characteristic is important at the production of hardened specimens under condition of hydro-thermal reaction. In this study, we investigated the strength properties of concrete used stone powder sludge as siliceous material. The test results under condition of hydro-thermal reaction shows the two main facts. The first, the stone powder sludge is affected to fluidity because the surface of the stone powder sludge has characteristics of flakily and angularity. The second, weight content of the stone powder sludge, is not effective factor to the properties of strength.

• 한국안전학회지
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• 제27권4호
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• pp.20-25
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• 2012

The purpose of this study is to analyze the thermal characteristics and to study fire hazard of electric leakage by iron power accumulated on circuit breaker in an iron processing factory. The thermal characteristics were analyzed while current was applied to the powder for ten minutes. Results showed that temperature of iron powder at 100 mA is $160^{\circ}C$ and at 175mA is $240^{\circ}C$. The sparks have occurred as iron powder drops between two(hot line and neutral line) wires and then iron powder explosion occurred while dropping continuously the iron powder on two lines. Those who work in the iron processing industry need to periodically remove and maintain the iron powder. The thermal characteristics in this paper can be used for electrical fire investigation and for basic data of thermal characteristic of leakage current through iron powder at iron processing factories.

• 한국분말재료학회지
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• 제15권1호
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• pp.53-57
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• 2008

The amorphous $Fe_{73}Si_{16}B_7Nb_3Cu_1$(at%) alloy strip was pulverized using a jet mill and an attrition mill to get flake-shaped powder. The flake powder was mixed with dielectric $BaTiO_3$ powder and its dispersant to increase the permittivity. The powders covered with dielectric powders and its dispersant were mixed with a binder and a solvent and then tape-cast to form sheets. The absorbing properties of the sheets were measured to investigate the roles of the dielectric powder and its dispersant. The results showed that the addition of $BaTiO_3$ powders and its dispersant improved the absorbing properties of the sheets noticeably. The powder sheet mixed with 5 wt% of $BaTiO_3$ powder and 1 wt% of dispersant showed the best electromagnetic wave absorption rate because of the increase of the permittivity and the electrical resistance.

• 한국분말재료학회지
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• 제9권5호
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• pp.315-321
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• 2002

Pure tantalum powder has been produced by combining Na as a reducing agent, $K_2TaF_{7}$ as feed material, KCl and KF as a diluent in a stainless steel(SUS) bomb, using the method of metallothermic reduction. The present study investigated the effect of the amount of the diluent and reaction temperature on the characteristics of tantalum powder in the production process. The temperature applied in this study $850^{\circ}C$ and the amount of the additional reductant from +5% of the theoretical amount used for the reduction of the entire $K_2TaF_{7}$. The results showed that as the amount of the diluent increased, the reaction temperature became lower because the diluent prevented a temperature rise. Also, according to the mixture ratio of the feed materials and the diluent changed from 1 : 0.25 to 1 : 2, the particle size decreased from $5\mutextrm{m}$ to $1\mutextrm{m}$ and a particle size distribution which is below 325 mesh in fined powder increases from 71% to 83%. The average size of Tantalum powder, $2-4\mutextrm{m}$, was close to that of the commercial powders($2-5\mutextrm{m}$). Also under this condition, impurities contained in the powder were within the range allowed for the commercial Ta powders.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1396-1400
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• 2007

In this study, poly(iso-butyl methacrylate-co-ethylene glycol dimethacrylate) [poly(iso-BMA-co-EGDMA)] microgel was prepared and used as a face powder additive. The spreading, adhesiveness, and skin reactivity of poly(iso-BMA-co-EGDMA) microgel-containing face powder II were investigated and compared with the same properties of commercially available Silica bead 700-containing face powder I. In the results, the particle size of the poly(iso-BMA-co-EGDMA) microgel was significantly swelled as a result of sebum absorption. Face powder II showed a lower primary irritation index and a higher adhesiveness than did face powder I. Face powder I showed a low sebum absorption ratio and a relatively high rate of sebum absorption, whereas face powder II, contrastingly, exhibited a high sebum absorption ratio and a low rate of sebum absorption, which properties would reduce the phenomena of facial strain and sliminess. These results indicate that poly(iso- BMA-co-EGDMA) microgel has outstanding sebum absorption characteristic and adhesiveness, and thus that it is a good candidate for use as a face powder additive.