• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.325-325
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• 2007

The perovskites in the $LaAlO_3-BaZrO_3$ system (i.e., $(1-x)LaAlO_3-xBaZrO_3$ were fabricated by a solid state reaction and their dielectric properties were investigated. For the compositions of x=0.1~0.9, the mixture of $LaAlO_3$ with a rhombohedral structure and $BaZrO_3$ with a cubic was observed when the sintering was conducted at $1500^{\circ}C$, indicating that the solubility of constituent elements was very low and a narrow solid solution region might exist. The large difference of ionic radii between $La^{3+}$ ion (0.136nm, C.N.=12) and $Ba^{2+}$ ion (0.161nm) or $Al^{3+}$ ion (0.0535nm, C.N.=6) and $Zr^{4+}$ ion (0.072nm) might hinder the mutual substitution. Within the compositions of x=0~0.7, the dielectric constant of the mixture increased with the amount of $BaZrO_3$, i.e., x value, which was in good agreement with the logarithmic mixing rule (In $_{r,i}={\Sigma}v_iln\;_{r,i}$). The increase in $BaZrO_3$ doping decreased $Q{\times}f$ value significantly due to the low $Q{\times}f$ value of $BaZrO_3$ itself, a poor microstructure of the mixture with an increased grain boundary area per volume, and defects in the cation and oxygen sub-lattices which were respectively caused by the evaporation of barium during the sintering process and the substitution of Ba on La-site or Al on Zr-site.

• 한국건설순환자원학회논문집
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• 제7권1호
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• pp.44-49
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• 2019

본 연구는 서로 다른 입도의 단일골재 및 반대 입도의 골재를 혼합한 혼합골재에 리젝트애시(Reject ash=Rj)의 치환율 변화에 따른 콘크리트의 기초적 특성을 분석함으로써 골재 제조공장에서 프리믹스하여 1개의 골재로 납품하는 혼합골재 시스템의 가능성을 분석하였다. 실험연구결과 입도규정의 경우는 혼합골재(CSb+SS)에 Rj를 5% 정도 치환할 경우 입도규정을 만족하는 것으로 나타났다. 유동성인 슬럼프 및 슬럼프 플로와 공기량의 경우에는 Rj의 치환율 증가에 따라 감소하는 것으로 나타났으나, 압축강도의 경우에는 Rj의 치환율이 증가함에 따라 증가하는 것이 확인되었다. 따라서 매립 처분되는 Rj를 5% 정도 혼합골재에 프리믹스하여 활용하면서 감수제 및 AE제 등으로 적정 유동성 및 공기량은 확보하여 준다면 압축강도 증진 등 품질향상에 크게 기여할 것으로 분석되었다.

• 동아시아식생활학회지
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• 제18권1호
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• pp.87-94
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• 2008

In this study, a nanatural fermentation starter formulation was developed for manufacturing bread products by substituting baker's yeast with naturally fermented raisin extract and sourdough. Four experimental groups containing 2.5, 5.0, 7.5, 10% naturally fermented raisin extract per 2,000 g of flour were compared based on quality characteristics, including the fermentation power on dough expansion, specific volume, baking loss, water activity, color, textural characteristics, and internal surface appearance. The activities of the naturally fermented raisin extract were examined in terms of pH changes, total titratable acidity, brix, and viable yeast counts. The raisin extract, which was cultured for 7 days at 30$^{\circ}C$, smelled of alcohol and produced $CO_2$. Yeast were also found in the extract after separation. As the incubation time of the raisin extract and sourdough increased, pH decreased, while total titratable acidity increased. The brix of the raisin extract increased until the $2^{nd}$ day of fermentation, and viable yeast counts increased until the $5^{th}$ day however, these gradually decreased by the $7^{th}$ day. The fermenting power on dough expansion increased in the bread with increasing incubation time. The bread samples containing 7.5% and 10% raisin extract had significantly higher specific volumes than the other samples. Baking loss was minimal with the 2.5% extract substitution. In analyzing the crumb, water activity, redness, and yellowness were highest in the 10.0% raisin extract bread samples, and lightness was maximal in the 5.0% group. In terms of textural characteristics, hardness was lowest with the 2.5% extract substitution. Gumminess, springiness, and chewiness were not significantly different among the bread samples. Cohesiveness was highest at the 7.5% extract substitution level, and resilience was lowest at the 10% level. In conclusion, based on the results, a natural fermentation starter formulated with 2.5% naturally fermented raisin extract (1 part raisins and 1.5 parts water) and 70% sourdough (1 part rye flour and 1 part water) has high potential as a baker's yeast substitute for making naturally fermented bread.

• 한국식품영양학회지
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• 제24권4호
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• pp.567-576
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• 2011

A study was undertaken to examine the antioxidative activity and the quality attributes of broccoli stem powder pound cakes. Broccoli stem powder was added to the batter at a ratio of 5, 10 and 15% respectively. The antioxidant activity was estimated by DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content in Broccoli stem powder and pounds cakes. Antioxidative activity was highly correlated with the total phenolic and total flavonoids contents of broccoli stem pound cakes respectively($r$=0.937, $r$=0.981). The effect of cake improver on quality characteristics of cake broccoli stem powder and pound cakes were estimated in terms of the specific load volume, hardness, hunter value of crumb and crust and sensory quality of cakes. The specific volume were increased significantly with increasing substitution level of cake improver and broccoli stem powder($p$ <0.01). The lightness were significantly decreased with increases in broccoli stem powder of pound cake crust and crumb($p$ <0.01, $p$ <0.01). The hardness, chewiness and gumminess and cohesiveness were tended to reduce in both of powder. The consumer acceptability score for 5~10% broccoli stem pound cakes ranked significantly($p$ <0.01) higher than those of the other groups in taste, flavor and overall preference. This results showed that cake improver & broccoli stem powder are a good ingredient to increase consumer acceptability and the healthy.

• 한국조리학회지
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• 제22권3호
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• pp.1-10
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• 2016

본 연구는 나문재를 밀가루 중량에 대해서 0%, 2%, 4%, 6%로 대체 첨가하여 스펀지케이크의 특성을 알아보았다. 반죽의 비중은 나문재 첨가량이 증가할수록 유의적으로 증가하였으며, 비용적은 나문재 함량이 많을수록 유의적으로 감소하였다. 무게는 나문재 첨가량이 증가함에 따라 유의적으로 증가하였으며, 굽기 손실은 나문재 첨가량이 증가함에 따라 유의적으로 감소하였다. 조직감에서는 대조구가 가장 낮은 경도와 가장 높은 탄력성을 나타내었다. 관능검사 결과, 조직감을 제외한 모든 항목에서 대조구에 비해 실험군의 수치가 높았으며, 그 중에서 향, 맛, 외관과 전체적인 기호도는 2~4% 첨가구가 가장 높았다.

• 한국식품조리과학회지
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• 제22권1호
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• pp.62-68
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• 2006

백련초 분말의 기능성을 지닌 케이크와 쿠키의 제조를 위해서 밀가루의 1%, 3%, 5%를 백련초 분말로 대체한 후에 케이크와 쿠키의 물리적, 관능적 특성을 평가하였다. 백련초 분말의 첨가로 케이크의 비체적은 유의적으로 증가하였고, 경도는 감소하였으나 유의적 차이는 없었다. 쿠키의 비체적은 대조군과 첨가군 간에 차이가 없었고 반죽내 수분함량에 의해 결정되는 퍼짐성은 첨가량이 많을수록 낮은 값을 보였다. 케이크의 껍질과 케이크 내부 색도 측정 결과, 첨가량이 증가할수록 L값은 낮아졌고, a값과 b값은 증가하였다. 쿠키의 색도 변화 역시 케이크와 동일한 양상이었는데 특히, a값은 시료간 큰 유의성을 보였다. 관능검사 결과, 대조군에 비해 백련초 분말을 첨가한 케이크의 풍미, 색깔, 조직감 등에 대한 평가가 높았고 전체적인 기호도에 대한 평가는 1% 첨가군이 가장 높은 값을 나타내었다. 쿠키의 관능검사에서는 대조군에 비해 맛, 풍미, 색깔, 조직감 등에서 백련초 분말의 첨가량이 증가할수록 높은 값을 나타내었고, 전체적인 기호도 평가 결과는 3% 첨가군이 가장 높은 선호도를 보였다.

• 한국식품조리과학회지
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• 제23권4호통권100호
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• pp.530-536
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• 2007

설탕의 50%를 이소말토올리고당 또는 프락토올리고당으로 대체한 쌀스폰지케이크의 품질 특성을 검토하였다. 올리고당을 사용한 스폰지케이크는 설탕만 사용한 대조군 스폰지케이크에 비해 반죽의 점도는 높고 비중은 낮았다. 올리고당 사용시 스폰지케이크의 굽기 손실은 감소하고 수분함량, 비체적, 부피 지수는 증가하였다. 스폰지케이크 표면 및 내부의 L값은 올리고당을 사용한 스폰지케이크가 대조군에 비해 낮아 더 어두운 스폰지케이크가 만들어진 것을 알 수 있었다. 올리고당을 사용한 스폰지케이크는 대조군에 비해 견고성, 씹힘성, 부서짐성이 낮아졌다. 관능검사에 의하면 올리고당을 사용한 스폰지케이크는 대조군에 비해 표면의 색이 진하고 단맛이 약하며 더 부드럽고 더 촉촉한 것으로 평가되었다. 선호도는 올리고당을 사용한 스폰지케이크가 대조군에 비해 높았으며 이소말토올리고당을 사용한 스폰지케이크가 가장 높은 선호도를 나타내었다.

• 동아시아식생활학회지
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• 제23권5호
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• pp.577-585
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• 2013

This study investigated the physicochemical and sensory characteristics of rice pound cake prepared with various amounts of blueberry powder. The weight of rice pound cakes with additions of 2~8% blueberry powder increased from 418.58 to 420.50 g. The volume and specific loaf volume of rice pound cakes prepared by adding blueberry powder were lower than those of the control. The baking loss rate for the control was 7.72% and that of rice pound cakes prepared by adding blueberry powder decreased by 6.98~6.56%. The moisture contents of rice pound cakes added with blueberry powder were higher than the control. The pH levels for rice pound cakes prepared with blueberry powder ranged between 6.47 and 7.58 and that of the control was 8.11. The microstructural observation by scanning electron microscopy (SEM) showed well developed air cells of control. DPPH radical scavenging activity of the control group was 13.6%, whereas pound cakes prepared by adding blueberry powder ranged from 35.2~78.8%. The "a" value of redness was increased, but L and b value were decreased significantly by additions of blueberry powder. The full textural properties of rice pound cakes were being significantly increased by additions of blueberry powder. Sensory evaluation scores in terms of appearance, flavor, taste, texture and overall preference for pound cakes showed that 4~6% of substituted sample groups were higher than those of others. The results of this study suggest that additions of 4~6% blueberry powder was the best substitution ratio for rice pound cakes.

• 한국식품조리과학회지
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• 제30권3호
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• pp.239-248
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• 2014

This study investigated the physicochemical and sensory characteristics of pound cake prepared with various amounts of dropwort powder. According to the results, the specific gravity of batter prepared with dropwort powder was increased, whereas the pH of batter was decreased significantly with the addition of dropwort powder. Furthermore, the weight of the pound cake prepared by adding 8% dropwort powder had the lowest among all samples. The volume and specific loaf volume of pound cakes prepared by adding dropwort powder were higher than those of the control. The baking loss rate of the control was 5.45% and that of pound cakes prepared by adding dropwort powder was 5.08~7.08%. In addition, the moisture content of pound cakes was found to increase with an increased in the amount of dropwort powder, whereas the pH of pound cakes was found to decrease with an increase in the dropwort powder content. The DPPH radical scavenging activity of the control group was 23.58%, whereas that of pound cakes prepared by adding dropwort powder ranged from 38.77~77.60%. However, the L, a and b values were decreased significantly by the addition of dropwort powder. The hardness, springiness, chewiness and brittleness of pound cakes were decreased significantly by the addition of dropwort powder. Overall, the sensory evaluation scores in terms of appearance, flavor, taste, texture and overall preference for pound cakes were conveyed to be higher in 4~6% of substituted sample groups than those of others. Hence, the results of this study suggest that addition of 4~6% dropwort powder is the best substitution ratio for pound cakes.

• 멤브레인
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• 제25권2호
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• pp.162-170
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• 2015

본 연구에서는 다양한 아민기를 가지는 폴리이미드 소재 및 분리막을 제조하여 그들의 구조의 변화에 따른 기체 투과도를 측정하였으며 동력학(Molecular dynamics; MD) 기술을 이용하여 해당 기체의 시간의 변화에 따른 위치와 속도를 계산하여, 기체분자의 동적 특성을 분석하는데 활용하였다. 투과도 측정결과 합성된 고분자 소재의 경우 고분자 내의 free volume을 증가시키는 치환기를 도입시켰을 경우 기체투과도가 증가되었으나 rigid한 구조가 도입된 폴리이미드는 투과도가 감소되는 경향을 확인하였다. 또한 분자동력학 시뮬레이션을 이용하여 기체투과거동 변화를 분석한 결과 실제 기체투과도 측정결과와 유사한 결과를 나타냄을 확인할 수 있었다.