검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 1,836

        341.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the body fat-lowering effect of garlic powder in peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α)-luciferase transgenic mice (TG). In this study, we generated transgenic mice with a PGC-1α promoter (—970/+412 bp) containing luciferase as a reporter gene. Mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (CON), or high-fat diets supplemented with 2% (GP2) or 5% (GP5) garlic powder for an additional 8 weeks. Dietary garlic powder reduced the body weight in the GP2 and GP5 groups, compared to the CON group. Furthermore, garlic supplementation significantly decreased the plasma levels of triglycerides, total cholesterol, and leptin in the GP5 group, compared to the CON group. Specifically, luciferase activity in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) was increased by garlic supplementation in a dose-dependent manner. These results suggest that the body fat-lowering effect of garlic powder might be related to PGC-1α by the increase in luciferase activity in liver, WAT, and BAT. Furthermore, transgenic mice might be useful for evaluating the body fat-lowering effect of various health functional foods.
        4,000원
        342.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the quality characteristics and antioxidant activities of salad dressing prepared with acaiberry powder (0, 1, 3, and 5%). The pH and titratable acidity increased as the acaiberry powder increased. The sugar content showed no significant differences between samples. The viscosity was lowest in the controls and increased with increasing amounts of the acaiberry powder. The lightness and yellowness values decreased, while the redness values increased with increasing amounts of acaiberry powder. The total polyphenol content ranged from 10.26-45.19 mg GAE/100 g, increasing with increased acaiberry powder levels. The antioxidant activities measured via DPPH radical scavenging activity, reducing power and FRAP also increased with increasing acaiberry powder concentrations. Finally, a consumer acceptance test revealed that up to 3% acaiberry powder could be added to salad dressing to provide high antioxidant activity without sacrificing sensory quality.
        4,000원
        343.
        2017.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        An optimum route to fabricate oxide dispersion strengthened ferritic superalloy with desired microstructure was investigated. Two methods of high energy ball milling or polymeric additive solution route for developing a uniform dispersion of Y2O3 particles in Fe-Cr-Al-Ti alloy powders were compared on the basis of the resulting microstructures. Microstructural observation revealed that the crystalline size of Fe decreased with increases in milling time, to values of about 15-20 nm, and that an FeCr alloy phase was formed. SEM and TEM analyses of the alloy powders fabricated by solution route using yttrium nitrate and polyvinyl alcohol showed that the nano-sized Y-oxide particles were well distributed in the Fe based alloy powders. The prepared powders were sintered at 1000 and 1100 oC for 30 min in vacuum. The sintered specimen with heat treatment before spark plasma sintering at 1100 oC showed a more homogeneous microstructure. In the case of sintering at 1100 oC, the alloys exhibited densified microstructure and the formation of large reaction phases due to oxidation of Al.
        4,000원
        344.
        2017.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnS powder was synthesized using a relatively facile and convenient glycothermal method at various reaction temperatures. ZnS was successfully synthesized at temperatures as low as 125 oC using zinc acetate and thiourea as raw materials, and diethylene glycol as the solvent. No mineralizers or precipitation processes were used in the fabrication, which suggests that the spherical ZnS powders were directly prepared in the glycothermal method. The phase composition, morphology, and optical properties of the prepared ZnS powders were characterized using XRD, FE-SEM, and UV-vis measurements. The prepared ZnS powders had a zinc blende structure and showed average primary particles with diameters of approximately 20~30 nm, calculated from the XRD peak width. All of the powders consisted of aggregated secondary powders with spherical morphology and a size of approximately 0.1~0.5 μm; these powders contained many small primary nanopowders. The as-prepared ZnS exhibited strong photo absorption in the UV region, and a red-shift in the optical absorption spectra due to the improvement in powder size and crystallinity with increasing reaction temperature. The effects of the reaction temperature on the photocatalytic properties of the ZnS powders were investigated. The photocatalytic properties of the assynthesized ZnS powders were evaluated according to the removal degree of methyl orange (MO) under UV irradiation (λ = 365 nm). It was found that the ZnS powder prepared at above 175 oC exhibited the highest photocatalytic degradation, with nearly 95 % of MO decomposed through the mediation of photo-generated hydroxyl radicals after irradiation for 60 min. These results suggest that the ZnS powders could potentially be applicable as photocatalysts for the efficient degradation of organic pollutants.
        4,000원
        345.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most of the red ginseng (RG) products contain active substances derived from hot water or alcohol extraction. Since active substances of RG are divided into two two types: water-soluble and liposoluble, water or alcohol is needed as an extraction solvent and this leads the different extraction yields and components of the active substances. To overcome the limit, whole red ginseng powder can be used and consumed by consumers. In this study, the physicochemical properties and extractable active substance contents of variable-sized RG powder (158.00 μm, 8.45 μm, and 6.33 μm) were analyzed, and dispersion stability was measured to investigate the suitable size of RG powder for industrial processing. In the results, no significant difference was found from the changes in color intensity and thiobarbutric acid tests at 4°C, 25°C, and 40°C for 4 weeks. There was no significant difference on the production of antioxidants and ginsenoside among the samples (p>0.05). In dispersion stability, RG-158.00 μm was precipitated immediately, and the dispersion stabilities between RG-8.45 μm and RG-6.33 μm showed no significant difference. It implies that fine RG is suitable for the production process. With further study, it seemed that the physicochemical effects of RG particle sizes can be clearly revealed.
        4,000원
        346.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanopowders provide better details for micro features and surface finish in powder injection molding processes. However, the small size of such powders induces processing challenges, such as low solid loading, high feedstock viscosity, difficulty in debinding, and distinctive sintering behavior. Therefore, the optimization of process conditions for nanopowder injection molding is essential, and it should be carefully performed. In this study, the powder injection molding process for Fe nanopowder has been optimized. The feedstock has been formulated using commercially available Fe nanopowder and a wax-based binder system. The optimal solid loading has been determined from the critical solid loading, measured by a torque rheometer. The homogeneously mixed feedstock is injected as a cylindrical green body, and solvent and thermal debinding conditions are determined by observing the weight change of the sample. The influence of the sintering temperature and holding time on the density has also been investigated. Thereafter, the Vickers hardness and grain size of the sintered samples have been measured to optimize the sintering conditions.
        4,000원
        347.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This purpose of this study was to investigate cooking characteristics of noodles prepared by adding 0, 2, 4 or 6 percent of Capsosiphon fulvescens to wheat flour containing konjac powder. Water binding capacity was significantly increased with increasing amounts of Capsosiphon fulvescens. Weight and volume of cooked noodles increased significantly in proportion with the amount of Capsosiphon fulvescens. Turbidity of the soup after cooking also increased with the addition of Capsosiphon fulvescens. Brightness(L) and redness(a) were decreased with addition of Capsosiphon fulvescens. Yellowness( b) increased. The color value of cooked noodles was decreased compared with that of wet noodles. Sensory evaluation scores revealed that cooked noodles with 4 percent addition group were highest in terms of color, flavor and overall acceptability. This study validates that addition of Amorphophallus konjac and 4 percent Capsosiphon fulvescens may improve functionality and preference of noodles.
        4,000원
        348.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of Goami 2 on the properties of Garaetteok. The moisture, crude protein, crude lipid and crude ash contents of the rice were 16.02, 5.40, 1.87 and 0.77%, respectively. The amylose contents (32.16%) and total dietary fiber contents (9.03%) were the highest in Goami 2. The water binding capacity of Goami 2 (167.84%) was higher than general rice flour. Using a rapid visco analyzer (RVA), the initial pasting temperature of Goami 2 was found to be the highest; also, the peak viscosities of Goami 2 were higher than general rice powder. To assess the effect of Goami 2 on the quality characteristics of Garaetteok, the rice-cake was made by adding various amounts of Goami 2 (0, 10, 20, 30, and 40% w/w) to rice. It was observed that higher the amount of added Goami 2, lower were the grades. In terms of the color values of Goami 2 addition, the L-values of Garaetteok were lower with increasing amount of Goami 2; addition of 40% Goami 2 had the lowest value. The textural properties (hardness) also showed that tteok containing the greater amounts of Goami 2 were considerably harder compared with the control. Sensory preference tests revealed that addition of less Goami 2 had the highest scores for appearance, color and overall acceptability, and the Goami 2 added was lower than control. Therefore, as compared to others cultivars, rice flour proved the most acceptable for the preparation of Garaetteok with cultivar rice.
        4,000원
        349.
        2017.08 KCI 등재 구독 인증기관·개인회원 무료
        This study added stevia leaf powder at ratios of 0.5, 1.0, 1.5, and 2.0 percent to Omija-pyun (Schisandra chinensis Jelly) as a natural low-calorie sweetener instead of sugar which is added to Omija-pyun in considerable amounts to evaluate quality characteristics and antioxidant activities compared to the control group with the addition of sugar. Moisture content of Omija-pyun expanded by increasing the measurement of stevia leaf powder (p<0.001), pH (p<0.01) and sugar content (p<0.001) decreased. L-values and b-values revealed a tendency to increase by adding more stevia leaf powder, but a-value revealed a tendency to decrease (p<0.001). Hardness (p<0.001) and chewiness (p<0.05) decreased by adding more stevia leaf powder. Based on the consumer preference evaluation, Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of color and flavor (p<0.001). The control group and Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of taste and texture (p<0.001). There were significant differences in the organoleptic properties except hardness between the samples by quantitative descriptive analysis. The control group revealed the highest preference in terms of redness and transparency, and redness and transparency tended to decrease by adding more stevia leaf powder (p<0.001). Organoleptic properties on bitterness and sourness were enhanced by adding more stevia leaf powder in the principal component analysis (PCA). Regarding antioxidant properties, total phenol compounds and flavonoid contents of Omija-pyun increased by adding more stevia leaf powder, and DPPH radical scavenging capacity also increased (p<0.001). Based on results, it is preferable to serve Omija-pyun with the addition of 1.0 percent stevia leaf powder instead of sugar within the context of quality and antioxidant activity.
        350.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe3O4/Fe/graphene nanocomposite powder is synthesized by electrical wire explosion of Fe wire and dispersed graphene in deionized water at room temperature. The structural and electrochemical characteristics of the powder are characterized by the field-emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, field-emission transmission electron microscopy, cyclic voltammetry, and galvanometric discharge-charge method. For comparison, Fe3O4/Fe nanocomposites are fabricated under the same conditions. The Fe3O4/Fe nanocomposite particles, around 15-30 nm in size, are highly encapsulated in a graphene matrix. The Fe3O4/Fe/graphene nanocomposite powder exhibits a high initial charge specific capacity of 878 mA/g and a high capacity retention of 91% (798 mA/g) after 50 cycles. The good electrochemical performance of the Fe3O4/Fe/graphene nanocomposite powder is clearly established by comparison of the results with those obtained for Fe3O4/Fe nanocomposite powder and is attributed to alleviation of volume change, good distribution of electrode active materials, and improved electrical conductivity upon the addition of graphene.
        4,000원
        351.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Titanium alloys have high specific strength, excellent corrosion and wear resistance, as well as high heatresistant strength compared to conventional steel materials. As intermetallic compounds based on Ti, TiAl alloys are becoming increasingly popular in the aerospace field because these alloys have low density and high creep properties. In spite of those advantages, the low ductility at room temperature and difficult machining performance of TiAl and Ti3Al materials has limited their potential applications. Titanium powder can be used in such cases for weight and cost reduction. Herein, pre-forms of Ti-Al-xMn powder alloys are fabricated by compression forming. In this process, Ti powder is added to Al and Mn powders and compressed, and the resulting mixture is subjected to various sintering temperature and holding times. The density of the powder-sintered specimens is measured and evaluated by correlation with phase formation, Mn addition, Kirkendall void, etc. Strong Al-Mn reactions can restrain Kirkendall void formation in Ti-Al-xMn powder alloys and result in increased density of the powder alloys. The effect of Al-Mn reactions and microstructural changes as well as Mn addition on the high-temperature compression properties are also analyzed for the Ti-Al-xMn powder alloys.
        4,000원
        352.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe-6.5 wt.% Si alloys are widely known to have excellent soft magnetic properties such as high magnetic flux density, low coercivity, and low core loss at high frequency. In this work, disc-shaped preforms are prepared by spark plasma sintering at 1223 K after inert gas atomization of Fe-6.5 wt.% Si powders. Fe-6.5 wt.% Si sheets are rolled by a powder hot-rolling process without cracking, and their microstructure and soft magnetic properties are investigated. The microstructure and magnetic properties (saturation magnetization and core loss) of the hot-rolled Fe-6.5 wt.% Si sheets are examined by scanning electron microscopy, electron backscatter diffraction, vibration sample magnetometry, and AC B–H analysis. The Fe-6.5 wt.% Si sheet rolled at a total reduction ratio of 80% exhibits good soft magnetic properties such as a saturation magnetization of 1.74 T and core loss (W5/1000) of 30.7 W/kg. This result is caused by an increase in the electrical resistivity resulting from an increased particle boundary density and the oxide layers between the primary particle boundaries.
        4,000원
        353.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was carried out to enhance the availability of blackberry. Since it is difficult to use blackberry as a fresh fruit, we investigated the quality characteristics of blackberry powder obtained by various drying methods (freeze drying and hot-air drying at 40~80℃). The L- and b-values of freeze-dried powder was higher than hot-air dried powder. The pH (3.2) was lowest and the acidity (14.4%) was highest in freeze-dried powder. In freeze drying, the brix degree was 65.7 °Bx, but it increased from 54.7 °Bx to 68.5 °Bx with increasing temperature during hot air drying. The total polyphenol and flavonoids contents were the highest in freeze-dried powder, at 9.3 and 6.2 mg/g, respectively. The levels increased as temperature increased in hot air drying. Anthocyanin content in freeze-dried powder was 8.51 mg/g, while it sharply decreased to 1.17~2.45 mg/g in hot-air drying. Vitamin C content in freeze drying (979.4 μg/g) was higher than that in hot-air drying (48.3~303.2 μg/g). The sample concentration required for 50% reduction of DPPH free radical scavenging (RC50) was 79.7 μg/mL in freeze drying, and showed high antioxidant activity. Also it decreased from 122.4 μg/mL to 87.7 μg/mL with temperature increase during hot air drying. We therefore conclude from the above results that freeze drying is more suitable for the production of blackberry powder, because this method showed high value of chromaticity, total polyphenol, flavonoid, anthocyanin content, vitamin C and antioxidant activity.
        4,000원
        354.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An agricultural waste, pomegranate (Punica granatum L.) peel is known to be rich in total phenolics, which are flavonoids having strong antioxidant effects. In this study, pomegranate peel sponge cakes were prepared with varying ratios of freeze dried pomegranate peel powder (0, 1, 3, 5, 7% (w/w)) to examine their effect on quality characteristics, retrogradation and antioxidant activities. The specific gravity and moisture contents of 3, 5, and 7% pomegranate peel powder showed higher values than the control and 1% group. Addition of pomegranate peel powder increased the batter yield, while there was a significant decrease in baking loss. Increasing pomegranate peel powder content significantly decreased the lightness (L) (from 75.03 to 57.04) and pH values, whereas redness (a), yellowness (b) and ΔE were increased. Increasing concentration of the peel powder also increased the hardness and chewiness, while the springiness and cohesiveness decreased. Considering the Avrami equation, Avrami exponene (n) decreased from 1.8055 (control) to 0.9199 (7% pomegranate peel powder). Time constant (1/k) was lowest in control (at 17.64) and highest in the 7% group (39.84). Total polyphenol, flavonoid content, DPPH and ABTS radical scavenging activities significantly increased with increments in the content of pomegranate peel powder. A sensory evaluation by the 7-point scaling method showed that the sponge cake containing 7% pomegranate peel powder had the highest scores in color, flavor, sweetness, chewiness and overall acceptability. Hence, it is considered that sponge cake supplemented with 7% pomegranate peel powder is the most appropriate for quality characteristics, retrogradation and antioxidant activities.
        4,500원
        355.
        2017.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Photoelectron-hole separation efficiency plays an important role in the enhancement of the photocatalytic activity of photocatalysts towards the degradation of organic molecules. In this study, TiO2/TiOF2 heterostructured composite powders with suitable band structures, which structures are able to separate photoelectron-hole pairs, have been synthesized using a simple and versatile ultrasonic spray pyrolysis process. In addition, their phase volume fractions have been controlled by varying the pyrolysis temperature from 400 oC to 800 oC. The structural and optical properties of the synthesized powders have been characterized by X-ray diffraction, scanning electronic microscopy and UV-vis spectroscopy. The powder with a phase volume ratio close to 1, compared with single TiOF2 and other composite powders with different phase volume fractions, was found to have superior photocatalytic activity for the degradation of rhodamine B. This result shows that the TiO2/TiOF2 heterostructure promotes the separation of the photoinduced electrons and holes and that this powder can be applicable to environmental cleaning applications.
        4,000원
        356.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the antioxidant, physicochemical, and sensory characteristics of dried type sodium-reduced bibimbap using dandelion complex powder (DCP). DCP is known to add moisture to the skin and relieve symptoms of atopic dermatitis. The sodium content of the standard sample was 1,110.87 mg per serving. The sodium was significantly reduced by 30%, resulting in 762.62 mg of sodium for the reduced sodium group (p<0.05). The ash contents of the standard sample group with DCP showed the highest value (3.17%) in all samples and was affected by minerals of DCP (p<0.05). The total flavonoid contents and ABTS radical scavenging activity, indicators of antioxidant, anticancer and antibacterial activities, showed significantly high activities with addition of DCP (p<0.05). In the sensory results, bulgogi and savory flavor of the samples with DCP showed significantly higher values, and samples with DCP received the highest scores for after-taste. All samples were confirmed to be microbiologically safe according to the food code applied to food manufacturers. Pathogenic microorganisms tests were either negative or not detected in all samples.
        4,000원
        357.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transparent conducting electrodes (TCEs) are attracting considerable attention as an important component for emerging optoelectronic applications such as liquid crystal displays, touch panels, and solar cells owing to their attractive combination of low resistivity (< 10-3 Ω cm) and high transparency (>80%) in the visible region. The solutionbased process has unique properties of an easy fabrication procedure, scalability, and low cost compared to the conventional vacuum-based process and may prove to be a useful process for fabricating TCEs for future optoelectronic applications demanding large scale and flexibility. In this paper, we focus on the introduction of a solution-based process for TCEs. In addition, we consider the powder materials used to fabricate solution-based TCEs and strategies to improve their transparent conducting properties.
        4,200원
        358.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Harmonic structure materials are materials with a core–shell structure having a shell with a small grain size and a core with a relatively large grain size. They are in the spotlight because their mechanical properties reportedly feature strength similar to that of a sintered powder with a fine grain size and elongation similar to that of a sintered powder with a coarse grain size at the same time. In this study, the tensile properties, microstructure, and stretchflangeability of harmonic structure SUS304L made using powder metallurgy are investigated to check its suitability for automotive applications. The harmonic powders are made by mechanical milling and sintered using a spark plasma sintering method at 1173 K and a pressure of 50 MPa in a cylindrical die. The sintered powders of SUS304L having harmonic structure (harmonic SUS304L) exhibit excellent tensile properties compared with sintered powders of SUS304L having homogeneous microstructure. In addition, the harmonic SUS304L has excellent stretch-flangeability compared with commercial advanced high-strength steels (AHSSs) at a similar strength grade. Thus, the harmonic SUS304L is more suitable for automotive applications than conventional AHSSs because it exhibits both excellent tensile properties and stretch-flangeability.
        4,000원
        359.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        복분자, 갈근 및 녹차 추출분말이 각각 1%(w/w)로 첨가된 조미액으로 제조된 한우 육포의 품질특성 및 항산화 활성을 비교하였다. 복분자, 갈근 및 녹차 추출분말이 첨가된 조미액의 항산화 활성은 무첨 가구에 비해 유의적으로 높았다. 식물류 추출분말이 첨가된 육포의 전단가는 대조구에 비해 유의적으로 낮았으며, 색차(ΔE)는 시료 간에 미미하였으며, 전반적인 기호도는 녹차 추출분말이 첨가된 육포 (G-BJ)에서 다소 높게 평가되었다. 육포의 저장과정 중 수분활성도는 저장 2주째에 대조구에서 유의적 으로 증가되었으나, 식물 추출분말이 첨가된 육포는 저장 1주에 비해 유의적인 증감을 보이지 않았다. 저장 4주 경과 후에는 모든 시료에서 수분활성도가 다소간 증가되는 경향이었다. 식물 추출분말이 첨가 된 육포를 4주간 실온에 저장하는 동안 지질과산화물의 함량은 유의적으로 증가하였다. G-BJ는 4주간 저장되었을 때 2주간 저장된 시료에 비해 유의적인 증가 현상을 보이지 않았다. 식물 추출분말이 첨가 된 육포의 항산화 활성은 대조구에 비해 유의적으로 높았으며, 특히 G-BJ에서 가장 높았다. 한우 육포 의 제조 시 식물 추출분말의 첨가는 육포의 전단가 감소와 항산화 활성을 증가시킴으로써 육포의 품질 향상에 효과적일 것으로 예상된다.
        4,600원
        360.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Porous polytetrafluoroethylene (PTFE) thin films are fabricated by spin-coating using a dispersion solution containing PTFE powders, and their crystalline properties are investigated after thermal annealing at various temperatures ranging from 300 to 500°C. Before thermal annealing, the film is densely packed and consists of many granular particles 200-300 nm in diameter. However, after thermal annealing, the film contains many voids and fibrous grains on the surface. In addition, the film thickness decreases after thermal annealing owing to evaporation of the surfactant, binder, and solvent composing the PTFE dispersion solution. The film thickness is systematically controlled from 2 to 6.5 μm by decreasing the spin speed from 1,500 to 500 rpm. A triboelectric nanogenerator is fabricated by spin-coating PTFE thin films onto polished Cu foils, where they act as an active layer to convert mechanical energy to electrical energy. A triboelectric nanogenerator consisting of a PTFE layer and Al metal foil pair shows typical output characteristics, exhibiting positive and negative peaks during applied strain and relief cycles due to charging and discharging of electrical charge carriers. Further, the voltage and current outputs increase with increasing strain cycle owing to accumulation of electrical charge carriers during charge-discharge.
        4,000원