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        검색결과 1,826

        261.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A conductive additive is prepared by dispersing multi-walled carbon nanotubes (MWCNTs) on Cu powder by mechanical milling and is distributed in epoxy to enhance its electrical conductivity. During milling, the MWCNTs are dispersed and partially embedded on the surface of the Cu powder to provide electrically conductive pathways within the epoxy-based composite. The degree of dispersion of the MWCNTs is controlled by varying the milling medium and the milling time. The MWCNTs are found to be more homogeneously dispersed when solvents (particularly, non-polar solvent, i.e., NMP) are used. MWCNTs gradually disperse on the surface of Cu powder because of the plastic deformation of the ductile Cu powder. However, long-time milling is found to destroy the molecular structure of MWCNTs, instead of effectively dispersing the MWCNTs more uniformly. Thus, the epoxy composite film fabricated in this study exhibits a higher electrical conductivity than 1.1 S/cm.
        4,000원
        262.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 헴프시드가루 첨가가 쌀쿠키의 품질특성에 미치는 영향을 알아보기 위해 밀가루 사용량 대비 헴프시드가루를 0%, 5%, 10%, 15%로 첨가하여 쿠키를 제조하고, 밀도, pH, 수분함량, 퍼짐성 지수, 색도, 경도 및 항산화 활성을 측정하였다. 쿠키의 밀도는 1.15~1.20 g/mL, pH는 6.29~6.45로 시료 간 유의적인 차이가 없었다. 수분함량은 4.86~5.83%로 헴프시드가루 첨가량이 증가할수록 대체로 감소하였다. 쿠키의 퍼짐성 지수는 대조군이 가장 낮았고, 첨가량이 증가 할수록 높아지는 경향을 나타내었다. 쿠키의 명도(L)는 헴프시드가루 첨가량이 증가함에 따라 감소한 반면에, 황색도(b)와 적색도(a)는 유의적인 차이가 없었다. 소비자 기호도 조사결과. 색과 향은 10% 첨가군이 가장 높은 점수로 평가되었으며, 맛과 조직감은 시료 간 유의적인 차이가 없었다. 전체적인 기호도는 10% 첨가군과 15% 첨가군이 높게 평가되었다. 총 폴리페놀 함량은 대조군이 7.15 mg GAE/100 g으로 가장 낮았고. 첨가군이 12.36~17.17 mg GAE/100 g으로 대조군보다 유의적으로 높게 나타났으며, DPPH radical 소거능은 60.02~ 80.63%로 헴프시드가루 첨가량이 증가할수록 증가하는 경향이었다. 이상의 결과를 종합하여 볼 때 쿠키 제조 시 헴프시드가루를 15%까지 첨가한다면 관능성 및 기능성 측면에서 바람직할 것으로 사료된다.
        4,000원
        263.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the quality characteristics of wet noodles added with sword bean powder(0, 5, 10, 15%) to determine the most preferred noodle recipe for consumer’s desire. The proximate composition of the sword bean powder was as follows: Moisture contents were 13.4±0.08%, protein 30.2±0.12%, fat 0.3±0.09%, protein 1.0±0.11% and carbohydrates 55.1±0.12%, respectively. Total amino acid content of sword bean powder was measured 23,054.266 mg/ 100 g, especially in the order of histidine, glutamic acid and aspartic acid. The flavonoid content of sword bean powder was 17.9750 mg%. Water-binding capacity increased as the level of sword bean powder increased. When viscosity of wheat flours containing sword bean powder was measured by amylograph, the gelatinization point increased significantly as the level of sword bean powder increased, but peak viscosity decreased. As the level of sword bean powder increased, L value decreased, whereas a and b values increased. Weight, water absorption and volume of cooked noodles prepared with wheat flours containing sword bean powder decreased, whereas turbidity of soup increased. For textural properties, addition of sword bean powder increased hardness, springiness, chewiness of cooked noodles, whereas adhesiveness decreased. According to sensory evaluation such as appearance, color, flavor, taste, texture, overall preference, it was revealed noodles with 10% sword bean powder was the most preferred. According to the results, the addition of sword bean powder positively affects the overall sensory evaluation of wet noodle, and 10% is the optimal level for addition.
        4,000원
        264.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The hydrogen reduction behavior of MoO3-CuO powder mixture for the synthesis of homogeneous Mo-20 wt% Cu composite powder is investigated. The reduction behavior of ball-milled powder mixture is analyzed by XRD and temperature programmed reduction method at various heating rates in Ar-10% H2 atmosphere. The XRD analysis of the heat-treated powder at 300oC shows Cu, MoO3, and Cu2MoO5 phases. In contrast, the powder mixture heated at 400oC is composed of Cu and MoO2 phases. The hydrogen reduction kinetic is evaluated by the amount of peak shift with heating rates. The activation energies for the reduction, estimated by the slope of the Kissinger plot, are measured as 112.2 kJ/mol and 65.2 kJ/mol, depending on the reduction steps from CuO to Cu and from MoO3 to MoO2, respectively. The measured activation energy for the reduction of MoO3 is explained by the effect of pre-reduced Cu particles. The powder mixture, hydrogen-reduced at 700oC, shows the dispersion of nano-sized Cu agglomerates on the surface of Mo powders.
        4,000원
        265.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to analyze the proximate components (water, crude ash, crude protein, crude fat, and carbohydrates) and nutritive components (vitamin A, C, E, minerals, amino acids, and fatty acids) of rice flour and develop several rice bread recipes using rice flour. The water, crude ash, crude protein, crude lipid, carbohydrate contents of rice flour were measured to be 8.53%, 0.10 g, 6.80 g, 0.14 g and 84.43 g, respectively. No vitamin A was detected in the rice flour, and vitamin C and E contents were found to be 8.30 and 0.3467 mg/100 g, respectively. Calcium, potassium, magnesium, iron, and sodium contents were measured as 6.23, 65.05, 9.78, 0.17 and 2.84 mg/100 g; the large amount of potassium helps to discharge the sodium. Rice flour has nine kinds of essential amino acids in it; essential amino acids form 45.15% of rice flour’s content. which is higher than 32.3%. Fatty acids were barely detected in the rice powder; saturated fatty acids were measured as 31.25 mg/100 g, and unsaturated fatty acids as 25.54 mg/100 g. Regarding essential fatty acids, linoleic acids were measured as 41.01 mg/100 g, and linolenic acids as 2.20 mg/100 g. The researcher used rice loaf bread as the base and developed rice bread recipes using rice flour to make a total of 11 items: 8 items with 75% rice flour (rice bagel, rice sweet red-bean bread, rice butter roll bread, rice mocha bread, rice buttertop bread, rice custard cream bread, and rice streusel), 2 items with 80% rice flour (stollen and rice hobbang), and 1 item with 85% rice flour (rice donut).
        4,000원
        266.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed in order to examine the functional and quality characteristics of raw noodles with added kale powder. The raw noodles were prepared at a concentration of 4, 8, and 12% (w/w) of the kale, based on flour weight. The antioxidant activity of kale powder, specifically DPPH free radical scavenging, reducing activity, and total phenolic content were found to be 75.16%, 1.24 (O.D.) and 44.47 mg GAE/g, respectively. Using Hunter Lab color values for raw noodle with added kale powder, L (lightness) values decreased with an increased concentration of kale powder, whereas a (redness) values decreased (p<0.001). In a texture analysis, chewiness (p<0.01), gumminess (p<0.001), and cohesiveness (p<0.001) increased significantly as the amount of added kale powder increased. According to sensory evaluations: color, flavor, taste, texture, and overall palatability had the highest score in noodle with 8% kale powder (p<0.001). During periods of storage, moisture contents were decreased when kale powder concentrations increased, but pH did not differ in any of the groups and bacteria cell counts were between 0% and 8%. Kale noodles were observed at 8% then 0%, decreased by 102 log CFU/g. The antioxidant activities of raw noodles with added kale powder were increased by 8%, a 30~50% increase over the control group. These results suggest that kale powder is useful as a functional food resource with antioxidant activities.
        4,000원
        267.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the antioxidant activity of Kochujang following the addition of Omija (Schizandra chinensis Baillon) by-product extract powder. This study specifically investigated the total levels of phenolics and flavonoids, the activities of DPPH and ABTS radical scavenging, and FRAP (ferric reducing antioxidant power). Our results showed that the total phenolic and flavonoid contents of unmodified Kochujang were 4.06 mg TAE/g and 2.87 mg TAE/g, respectively, and that the total phenolic and flavonoid contents of Kochujang with added Omija by-product extract powder were 3.89~5.19 mg TAE/g and 3.11~5.35 mg TAE/g, respectively. As more Omija by-product extract powder was added, the more the total levels of phenolic compounds and flavonoids increased. This study found that DPPH radical scavenging activity in unmodified Kochujang was 25.8% and that in Kochujang with added Omija by-product extract powder was 27.1~39.7% each. These results indicate that Omija by-product extract powder has possibility not only in Kochujang products but also as a functional food with antioxidant activity characteristics. These results also indicate that adding Omija by-product extract powder to Kochujang had significant effects on overall acceptability. Thus, the addition of 5 or 10% of Omija by-product extract powder is desirable for making Kochujang.
        4,000원
        268.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the effects of Boehmerianivea powder on the functional and sensory characteristics of dumpling shell. Various dumpling shell samples were prepared with wheat flour containing different amounts of Boehmerianivea powder. The instrumental characteristics were examined and sensory evaluations were performed. According to the amylograph data, the composite Boehmerianivea powder-wheat flour samples had increased gelatinization temperatures with increasing Boehmerianivea powder content; whereas the initial viscosity at 95oC, viscosity at 95oC after 15 minutes, and the maximum viscosity were reduced. The L, a and b Hunter’s color values decreased with increasing Boehmerianivea powder content. In addition to thecooked weight, the cooked volume and turbidity of dumpling shellincreased with increasing level of Boehmerianivea powder. In terms of the textural characteristics, the addition of Boehmerianivea powder increased the chewiness, smoothness and adhesiveness. The DPPH free radical scavenging activity increased significantly with increasing content of Boehmerianivea powder (p<0.05). Finally, the results of thesensory properties indicated that 5% Boehmerianivea powder had the highest scores. These results suggest that Boehmerianivea powder can be applied to dumpling shells to achieve high quality and functionality.
        4,000원
        269.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The sensory characteristics of a rice processed snack for 6 to 12 month old infants were investigated. The microbiological safety of all samples was also tested. The moisture content of snack of the SW snack was 6.33 significantly higher than in the other snacks (p<0.05). The sensory intensities of RW were highest in glossiness brightness, uniformity, sweet aroma, savory flavor, sweet flavor, chewiness and crispiness. In the; consumer acceptance test, RW showed significantly higher glossiness, uniformity, sweet aroma, savory flavor, sweet flavor, rancid, chewiness, adhesiveness, crispiness and overall acceptance than the other snacks (p<0.05). The aerobic plate counts were negative in all the samples tested. E. coli and pathogenic microorganisms tests were also negative or not detected, showing that all the samples tested were microbiologically safe according to the food code which applies to food manufacturers. Overall, potentially high value products of rice processed snacks for 6 to 12 month old infants were developed and tested They are expected to be utilized and in the competitive and growing infant food industry.
        4,000원
        270.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study focuses on the fabrication of a WC/Co composite powder from the oxide of WC/Co hardmetal scrap using solid carbon in a hydrogen gas atmosphere for the recycling of WC/Co hardmetal. Mixed powders are manufactured by mechanically milling the oxide powder of WC-13 wt% Co hardmetal scrap and carbon black with varying powder/ball weight ratios. The oxide powder of WC-13 wt% Co hardmetal scrap consists of WO3 and CoWO4. The mixed powder mechanically milled at a lower powder/ball weight ratio (high mechanical milling energy) has a more rapid carbothermal reduction reaction in the formation of WC and Co phases compared with that mechanically milled at a higher powder/ball weight ratio (lower mechanical milling energy). The WC/Co composite powder is fabricated at 900℃ for 6 h from the oxide of WC/Co hardmetal scrap using solid carbon in a hydrogen gas atmosphere. The fabricated WC/Co composite powder has a particle size of approximately 0.25-0.5 μm.
        4,000원
        271.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report a method for preparing rare earth oxides (RexOy) from the recycling process for spent Ni-metal hydride (Ni-MH) batteries. This process first involves a leaching of spent Ni-MH powders with sulfuric acid at 90℃, resulting in rare earth precipitates (i.e., NaRE(SO4)2·H2O, RE = La, Ce, Nd), which are converted into rare earth oxides via two different approaches: i) simple heat treatment in air, and ii) metathesis reaction with NaOH at 70℃. Not only the morphological features but also the crystallographic structures of all products are systematically investigated using field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD); their thermal behaviors are also analyzed. In particular, XRD results show that some of the rare earth precipitates are converted into oxide form (such as La2O3, Ce2O3, and Nd2O3) with heat treatment at 1200℃; however, secondary peaks are also observed. On the other hand, rare earth oxides, RExOy can be successfully obtained after metathesis of rare earth precipitates, followed by heat treatment at 1000℃ in air, along with a change of crystallographic structures, i.e., NaRE(SO4)2·H2O → RE(OH)3 → RExOy.
        4,000원
        272.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a new Co10Fe10Mn35Ni35Zn10 high entropy alloy (HEA) is identified as a strong candidate for the single face-centered cubic (FCC) structure screened using the upgraded TCFE2000 thermodynamic CALPHAD database. The Co10Fe10Mn35Ni35Zn10 HEA is fabricated using the mechanical (MA) procedure and pressure-less sintering method. The Co10Fe10Mn35Ni35Zn10 HEA, which consists of elements with a large difference in melting point and atomic size, is successfully fabricated using powder metallurgy techniques. The MA behavior, microstructure, and mechanical properties of the Co10Fe10Mn35Ni35Zn10 HEA are systematically studied to understand the MA behavior and develop advanced techniques for fabricating HEA products. After MA, a single FCC phase is found. After sintering at 900℃, the microstructure has an FCC single phase with an average grain size of 18 μm. Finally, the Co10Fe10Mn35Ni35Zn10 HEA has a compressive yield strength of 302 MPa.
        4,000원
        274.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 저지방 소시지의 개발을 위해 밤가루의 지방대체 기능을 평가하기 위하여 실시하였다. 실 험 1은 우선 모델 소시지를 제조하여 지방대체재로써 Soy protein isolate(SPI)와 Konjac flour(KF)를 혼합 사용한 것은 SPI 단독 처리구에 비해 조직감(경도, 검성, 저작성)에서 낮은 값을 보였지만, 지방과 단백질 함량이 높고 수분 함량은 낮은 값을 보였다(p<0.05). 또한 SPI 단독 처리구는 SPI+KF 복합처 리구에 비해 유리수분량이 높은 결과를 나타내었다. 한편 밤가루의 첨가는 조직감(경도, 검성)이 유의적 으로 높아지는 결과를 나타내었다. 실험 2는 지방대체재로써 SPI를 단독으로 사용하고 밤가루의 첨가가 가열 방법의 차이(자비, 훈연)에 따른 효율성을 평가하기 위해 실험을 실시하였다. 자비 소시지는 훈연 소시지에 비해 명도가 높고, 수분 함량이 높았지만, 조직감(경도, 검성, 저작성, 응집성)이 낮게 측정되 었다. 또한 자비 소시지는 훈연 소시지에 비해 가열감량이 적었지만, 유리수분양은 많았다. 제품 소시 지에 밤가루의 첨가는 조직감 중 저작성이 증가하는 경향을 나타내었다.
        4,000원
        275.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        표고 재배용 액체종균 배지조성은 대두박분 배지에 입도가 850 μm이하인 참나무분 0.3% 첨가 시 균사체 건중량이 457 mg으로 다소 높았으며, Laccase 활성도는 참나무분 첨가율별 대두박분 배지에 큰 차이가 없었으나 Cellulase 활성도는 CMC Agar Plate에서 26.4 mm로서 참나무분 첨가율별 대두박분 액체종균 처리구중에서 가장 우수하였다. 액체종균의 통기량이 증가할수록 이산화탄소 발생량이 증가하여 배양 7일째 최대치를 나타내었으며 균사체 건중량은 10일째 3.0g/l로 가장 우수한 것으로 나타났다. 통기량이 증가할수록 이산화탄소 발생량, 균사체 건중량도 증가하였으며 0.6vvm 처리시 배지 증발율이 32%, 균사체 건중량이 3.5g/l로서 우수하였다. 선발된 액체종균을 톱밥 종균과 생산성 비교를 위하여 톱밥재배 봉지배지에 시험한 결과, 액체종균의 생육기간이 톱밥종균에 비해 1일 지연되었으나, 봉지당 유효 개체수와 수량에는 유의적인 차이가 없는 것으로 나타났다.
        4,000원
        276.
        2018.06 구독 인증기관 무료, 개인회원 유료
        아연(zinc) 분말은 철의 부식을 막아주는 희생양극의 기능으로 자동차, 선박 및 철구조물의 부식을 방지하 는데 널리 사용되고 있다. 그러나 아연 분말은 높은 비중 때문에 수지나 용매 내에서 분산성이 저하되고 빠르게 침전이 일어나는 단점을 가진다. 본 연구에서는 실리카(SiOx)를 미세 아연분말의 표면에 코팅함으로써 아연분말의 물성 및 기능을 개선하고자 하였다. 아연분말의 실리카 표면코팅은 졸-겔법을 사용하였고 SEM/EDS의 표면 및 성분분석과 TEM 단면분석을 통하여 불순물이 잔존하지 않는 실리카 코팅이 성공적으로 형성됨과 그 코팅의 두께를 확인 할 수 있었다. 한편 코팅공정의 반복회수와 평균입도 변화와의 관계를 측정하여 2회까지의 반복코팅이 분산안정성을 유지하는데 효과적임을 확인하였다. 이 밖에 실리카 코팅 아연분말의 진비중(true density) 측정을 통해 코팅 공정에 의해 비중이 20% 이상 감소함을 확인하였고 제타포텐셜 측정으로 실리카 코팅에 의해 아연분말의 분산안정성이 4배까지 증가함을 확인하였다. 마지막으로 질산수용액 담지를 통해 실리카 코팅 아연분말의 내산성 향상 또한 확인하였다. 따라서 본 연구에서 제조된 실리카 코팅 아연분말은 방청 안료의 원료로 적합할 것으로 기대된다.
        4,000원