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        검색결과 1,826

        681.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of Nelumbo nucifera G. (NN) powder on cookie quality characteristics. The cookies were made with various NN powder levels (1, 3, and 5%). Crude fiber, crude ash, and the Mg contents of cookies with added NN powder were higher in concentration than those of the control group. Salinity of NN-powder added groups was not significantly different when it was compared with the control group's salinity. No significant difference among the groups were observed for specific volume, but the width determined by water content in the dough decreased as the amount of added NN powder increased. The L-value of the cookies was significantly larger than that of the control group. The a- and b-values were the highest for the 5% substituted NN flour. According to the sensory evaluation of the cookies, scores for color, flavor, and texture increased with increasing amounts of added NN powder. The overall acceptance of the 3% NN added cookies was greater than that of the 1 and 5% cookies.
        4,000원
        682.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        야콘 분말의 대체량을 0-30%로 달리하여 스펀지 케이크를 제조한 후 물리화학적 및 관능적 품질특성을 비교하였다. 야콘 분말의 대체비율이 증가함에 따라 반죽의 비중은 단계별로 유의적으로 증가하였고 pH는 감소하는 경향을 나타내었다. 한편 케이크의 비체적과 수분함량은 야콘 분말 대체에 따라 유의적으로 감소하였고 굽기 손실은 증가하였다(p<0.05). 부피지수는 감소하는 경향을 보여 야콘 분말 비율이 높아지면 케이크의 부피 또는 높이가 작아짐을 알 수 있었다. 반면 대칭지수는 야콘 분말 대체량에 따른 유의적인 차이를 나타내지 않았다(p > 0.05). 밝기는 나타내는 L*값은 유의적으로 감소하였으며(p < 0.05), 경도는 점차적으로 증가하였으나 20% 및 30% 대체군 사이에 유의적인 차이는 발견되지 않았다. 소비자 기호도 검사결과 대조군, 10% 및 20% 대체군 사이에 전체적인 기호도에 대한 유의적인 차이는 발견되지 않았으나(p > 0.05), 관능품질을 저해하지 않고 야콘 분말의 건강 기능성 효과 등을 고려할 때 20% 대체군이 가장 적절한 것으로 판단된다.
        4,000원
        683.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 아마씨 가루를 밀가루 중량기준 0%, 6%, 12%, 18%의 비율로 첨가한 쿠키를 제조한 다음, 반죽의 밀도, pH, 수분 함량, 쿠키의 퍼짐성, 손실률, 팽창률, 경도, 색도, 관능평가, 과산화물가, 산가 등을 측정하였다. 반죽의 밀도는 대조군과 실험군 간에 유의적인 차이가 없었고 pH는 첨가군이 대조군보다 높게 나타났으며 수분 함량은 낮게 나타났다. 퍼짐성은 아마씨 가루 첨가량이 증가할수록 증가하였고(p<0.05) 손실률은 대조군과 6% 첨가군 간에 유의적인 차이가 없었고 12% 첨가군이 가장 높았으며 18% 첨가군이 가장 낮았다. 팽창률은 대조군과 6%, 12% 첨가군 간에 차이가 없는 반면, 18% 첨가군은 대조군보다 감소하였다. 경도는 아마씨 가루 첨가군이 대조군보다 유의적으로 낮았고(p<0.05) 명도와 황색도는 아마씨 가루 첨가량이 증가할수록 감소하였다. 관능검사결과 아마씨 가루 첨가량이 증가할수록 쿠키의 표면색, 고소한 맛이 강하게 평가되었고 전반적인 기호도는 12% 첨가군이 대조군보다 높은 점수로 평가되었다(p<0.05). 저장 기간에 따른 산화 안정성을 측정한 결과 과산화물가는 모든 시료에서 저장 30일까지 증가하다가 감소하였고 산가는 저장기간 동안 지속적으로 증가하였으며 각 시료 간에 유의적인 차이는 없었다.
        4,000원
        684.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대두에서 산패취를 발생시키는 lipoxygenase 효소를 비가열 전처리 방법인 초고압 처리 방법을 이용하여 효소의 활성도의 변화를 확인하였다. 연구 결과 초고압 처리에 의해 lipoxygenase 효소의 활성도가 감소하는 것을 확인하였다. 또한 lipoxygenase 효소의 활성도 감소에 의해 대두의 저장성에 미치는 영향을 확인하기 위해 국산 대두와 연해주 대두를 이용하여 저장 실험을 실시하였다. 실험 결과 국산 대두의 경우 초고압 처리에 의해 lipoxygenase 효소의 활성도가 감소하였으나 TBA값에 영향을 주는 자동산화 등의 화학반응에 의해 TBA값이 지속적으로 증가함을 보여주었다. 그러나 연해주 대두의 경우에는 초고압 처리를 한 시료의 TBA값의 증가정도가 상대적으로 낮게 측정된 것을 확인하였다. 이는 연해주 대두가 항산화 성분을 국산콩에 비하여 많이 포함하고 있어 초고압 처리에 의한 lipoxygenase 효소의 불활성과 함께 항산화 성분의 영향으로 TBA값의 저장 중 증가 정도가 낮게 측정된 것으로 판단되어진다.
        4,000원
        685.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유기용매와 초임계유체를 사용하여 대두분말에서 지방성분을 추출하는 공정에서 분말화공정(분쇄)의 시간의 변화에 따른 입자도와 초고압처리에 의한 추출속도를 측정하였다. 대두분말의 입자가 작을수록 추출속도가 향상되었으면 이는 입자의 크기가 작아짐에 따라 전체적인 표면적이 증가하여 고-액추출에서 중요한 반응기작인 물질전달속도를 증가시켰기 때문이라 판단된다. 초고압공정을 적용 시 동일한 입자크기에서 추출속도가 현저히 향상되었으며 이는 대두분말 내부에서 발생하는 확산현상에 대한 저항이 초고압상태에서의 변화로 감소되었기 때문이라 사료된다. 초임계유출에 의한 추출은 수율이 낮은 단점이 있으나 입자의 크기가 큰 상태에서는 초고압처리를 전처리로 사용할 경우 시간당 추출량을 상당부분 증가시킬 수 있음을 보여주었으나, 입자크기가 작을 경우 초고압처리가 영향을 미치지 못함을 보여주었다.
        4,000원
        686.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zr-Ti alloy powders were successfully synthesized by magnesium thermal reduction of metal chlorides. The evaporated and mixed gasses of were injected to liquid magnesium and the chloride components were reduced by magnesium leading to the formation of . The released Zr and Ti atoms were then condensed to particle forms inside the mixture of liquid magnesium and magnesium chloride, which could be dissolved fully in post process by 1~5% HCl solution at room temperature. By the fraction-control of individually injected and gasses, the final compositions of produced alloy powders were changed in the ranges of Zr-0 wt.%~20 wt.%Ti and their purity and particle size were about 99.4% and the level of several micrometers, respectively.
        4,000원
        687.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cemented tungsten carbide has been used in cutting tools and die materials, and is an important industrial material. When the particle size is reduced to ultrafine, the hardness and other mechanical properties are improved remarkably. Ultrafine cemented carbide with high toughness and hardness is now widely used. The objective of this study is synthesis of nanostructured WC-Co powders by liquid phase method of tungstate. The precursor powders were obtained by freezen-drying of aqueous solution of soluble salts, such as ammonium metatungstate, cobalt nitrate. the final compositions were WC-10Co. In the case of liquid phase method, it can be observed synthesis of WC-10Co. The properties of powder produced at various temperature, were estimated from the SEM, BET and C/S analyser.
        4,000원
        688.
        2011.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Inkjet printing was successfully done using Cu nano powder ink after these Cu nano powders were dry-coated with 1-octanethiol for oxidation prevention. 1-octanethiol, which is Self-Assembled Multi-layers (SAMs), was coated approximately 10-nm thick on the surface of Cu nano powders. 1-Octanol, which has the same chain length as that for 1-octanethiol, was used as a solvent to make the ink for inkjet printing. As a result, the fabricated ink was dispersed for about 4 weeks, and after printing and heat treatment at for 4 hours, the resistivity for the printed pattern was measured to be .
        4,000원
        689.
        2011.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, by using tin chloride solution as a raw material, a nano-sized tin oxide powder with an average particle size below 50 nm is generated by a spray pyrolysis process. The properties of the generated tin oxide powder depending on the inflow speed of the raw material solution are examined. When the inflow speed of the raw material solution is 2 ml/min, the majority of generated particles appear in the shape of independent polygons with average size above 80-100 nm, while droplet-shaped particles show an average size of approximately 30 nm. When the inflow speed is increased to 5 ml/min, the ratio of independent particles decreases, and the average particle size is approximately 80-100 nm. When the inflow speed is increased to 20 ml/min, the ratio of droplet-shaped particles increases, whereas the ratio of independent particles with average size of 80-100 nm decreases. When the inflow speed is increased to 100 ml/min, the average size of the generated particles is around 30-40 nm, and most of them maintain a droplet shape. With a rise of inflow speed from 2 ml/min to 5 ml/min, a slight increase of the XRD peak intensity and a minor decrease of specific surface area are observed. When the inflow speed is increased to 20 ml/min, the XRD peak intensity falls dramatically, although a significant rise of specific surface area is observed. When the inflow speed is increased to 100 ml/min, the XRD peak intensity further decreases, while the specific surface area increases.
        4,000원
        690.
        2011.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nanostructured cobalt materials have recently attracted considerable attention due to their potential applications in high-density data storage, magnetic separation and heterogeneous catalysts. The size as well as the morphology at the nano scale strongly influences the physical and chemical properties of cobalt nano materials. In this study, cobalt nano particles synthesized by a a polyol process, which is a liquid-phase reduction method, were investigated. Cobalt hydroxide (Co(OH)2), as an intermediate reaction product, was synthesized by the reaction between cobalt sulphate heptahydrate (CoSO4·7H2O) used as a precursor and sodium hydroxide (NaOH) dissolved in DI water. As-synthesized Co(OH)2 was washed and filtered several times with DI water, because intermediate reaction products had not only Co(OH)2 but also sodium sulphate (Na2SO4), as an impurity. Then the cobalt powder was synthesized by diethylene glycol (DEG), as a reduction agent, with various temperatures and times. Polyvinylpyrrolidone (PVP), as a capping agent, was also added to control agglomeration and dispersion of the cobalt nano particles. The optimized synthesis condition was achieved at 220˚C for 4 hours with 0.6 of the PVP/Co(OH)2 molar ratio. Consequently, it was confirmed that the synthesized nano sized cobalt particles had a face centered cubic (fcc) structure and with a size range of 100-200 nm.
        4,000원
        691.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spherical nanosized cobalt powder with an average size of 150-400 nm was successfully prepared at room temperature from cobalt sulfate heptahydrate (). Wet chemical reduction method was adopted to synthesize nano cobalt powder and hypophosphorous acid () was used as reduction agent. Both the HCP and the FCC Co phase were developed while concentration ranged from 0.7 M to 1.1 M. Secondary phase such as and were also observed. Peaks for the crystalline Co phase having HCP and FCC structure crystallized as increasing the concentration of , indicating that the amount of reduction agent was enough to reduce . Consequently, a homogeneous Co phase could be developed without second phase when the ratio exceeded 7.
        4,000원
        692.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the current study, the effects of particle size on compaction behavior of water-atomized pure iron powders are investigated. The iron powders are assorted into three groups depending on the particle size; 20-45 , 75-106 , and 150-180 for the compaction experiments. The powder compaction procedures are processed with pressure of 200, 400, 600, and 800 MPa in a cylindrical die. After the compaction stage, the group having 150-180 of particle size distribution shows the best densification behavior and reaches the highest green density. The reason for these results can be explained by the largest average grain size in the largest particle group, due to the low plastic deformation resistance in large grain sized materials.
        4,000원
        696.
        2011.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effect of solvent on the fabrication of Ni-free Fe-based alloy nano powders by employing the PWE (pulsed wire evaporation) in liquid and compared the alloy particles fabricated by three different methods (PWE in liquid, PWE in Ar, plasma arc discharge), for high temperature oxidation-resistant metallic porous body for high temperature soot filter system. Three different solvents (ethanol, acetone, distilled water) of liquid were adapted in PWE in liquid process, while X-ray diffraction (XRD), field emission scanning microscope (FE-SEM), and transmission electron microscope (TEM) were used to investigate the characteristics of the Fe-Cr-Al nano powders. The alloy powder synthesized by PWE in ethanol has good particle size and no surface oxidation compared to that of distilled water. Since the Fe-based alloy powders, which were fabricated by PWE in Ar and PAD process, showed surface oxidation by TEM analysis, the PWE in ethanol is the best way to fabricate Fe-based alloy nano powder.
        4,000원
        697.
        2011.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effect of wire diameter and applied voltage on the fabrication of Ni-free Fe-based alloy nano powders by employing the PWE (pulsed wire evaporation) in liquid, for high temperature oxidation-resistant metallic porous body for high temperature particulate matter (or soot) filter system. Three different diameter (0.1, 0.2, and 0.3 mm) of alloy wire and various applied voltages from 0.5 to 3.0 kV were main variables in PWE process, while X-ray diffraction (XRD), field emission scanning microscope (FE-SEM), and transmission electron microscope (TEM) were used to investigate the characteristics of the Fe-Cr-Al nano powders. It was controlled the number of explosion events, since evaporated and condensed nano-particles were coalesced to micron-sized secondary particles, when exceeded to the specific number of explosion events, which were not suitable for metallic porous body preparation. As the diameter of alloy wire increased, the voltage for electrical explosion increased and the size of primary particle decreased.
        4,000원
        698.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 느타리, 노랑느타리, 분홍느타리, 버들송이의 건조분말을 이용하여 두부에 적합한 첨가량을 구명하고자 수행되었다. 버섯 첨가량에 따른 두부수율은 대조(무첨가)구에 비해 느타리 3~12%, 노랑느타리 3, 6%, 분홍느타리 3, 6%, 버들송이 3, 6% 첨가시에 수율이 높았고, 버들송이는 9%이상 첨가시 고형이 되지 않았다. 경도는 느타리버섯 3, 6%, 노랑느타리 3%, 분홍느타리 3%, 버들송이 3% 첨가시에 높았다. 버섯의 첨가량이 많을수록 명도는 낮아졌으며, 적색도는 분홍느타리 첨가비율이 높을수록 증가 하였지만 노랑느타리는 황색도가 증가하지 않았다. 버섯두부의 기호도조사결과 느타리버섯은 6~12%, 노랑느타리버섯은 3%, 분홍느타리 3%, 버들송이 3, 6% 첨가시 기호도가 우수한 것으로 나타났다. 이상의 결과 수율과 경도가 높고 기호도가 우수한 두부에 제조에 적합한 버섯의 적정 첨가량은 느타리버섯 6%, 노랑느타리, 분홍느타리, 버들송이 각3%로 판단된다.
        4,000원
        699.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Freeze-dried Ecklonia cava powder was incorporated into cookie dough at 5 levels (0%, 1.5%, 3%, 4.5%, and 6%, w/w) by replacing equivalent amount of wheat flour of the cookie dough. After aging and sheeting, cookies were baked at 185oC for 14 min in a convection oven. The baked cookies were cooled to room temperature for 30 min and packed in airtight bags prior to all measurements. Lightness (L*) decreased significantly as the E. cava powder content increased (p<0.05) and a decreasing trend in both redness (a*-value) and yellowness (b*-value) was observed. On the other hand, firmness increased significantly with an increase in E. cava powder content (p<0.05). Increases in E. cava powder concentration up to 6% in the cookie formulation significantly increased the intensities of all sensory attributes such as color, flavor, taste, and firmness (p<0.05). Correlation analysis indicated that the E. cava concentration correlated significantly with most of the properties except for a*-value (p<0.01, 0.05, or 0.001). Properties such as firmness and sensory color and firmness correlated positively while L*- and b*-values correlated negatively with E. cava concentration. Sensory color correlated negatively with L*- and b*-values. Sensory firmness correlated positively with mechanically measured firmness.
        4,000원
        700.
        2011.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nano-technology is a super microscopic technology to deal with structures of 100 nm or smaller. This technology also involves the developing of TiO2 materials or TiO2 devices within that size. The aim of the present paper is to synthesize WOx doped nano-TiO2 by the Sonochemistry method and to evaluate the effect of different percentages (0.5-5 wt%) of tungsten oxide load on TiO2 in methylene blue (MB) elimination. The samples were characterized using such different techniques as X-ray diffraction (XRD), TEM, SEM, and UV-VIS absorption spectra. The photo-catalytic activity of tungsten oxide doped TiO2 was evaluated through the elimination of methylene blue using UV-irradiation (315-400nm). The best result was found with 5 wt% WOx doped TiO2. It has been confirmed that WOx-TiO2 could be excited by visible light (E<3.2 eV) and that the recombination rate of electrons/holes in WOx-TiO2 declined due to the existence of WOx doped in TiO2.
        4,000원