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        검색결과 1,826

        284.
        2018.05 구독 인증기관·개인회원 무료
        In this thesis, it was considered that in durability characteristics of concrete pavements evaluation of strength characteristics as well as abrasion resistance is important as the domestic concrete pavements couldn't fulfill the public needs and cases of damage are increasing. In order to solve such problems, it is intended to compare the abrasion resistance in accordance with the mixing rate of admixtures (silica fume and polymer powder) which are incorporated in the upper layer of two-lift concrete pavement and find the optimum mixing rate for abrasion resistance by focusing on the high performance of concrete pavements through two-lift concrete pavements which use cellular sprayed concrete construction method. Both test results, which were performed based on ASTM C 779 B (dressing wheel abrasion test method) and ASTM C 944 (rotary cutter method) standards in accordance with silica fume and polymer powder mixing rate that was incorporated in the upper layer of two-lift concrete pavement, proofed that the abrasion resistance increased as the mixing rate of silica fume and polymer powder increased. However, it was also confirmed that if the mixing rate of admixtures is excessively increased it will not have an effect and it will rather decrease the abrasion resistance.
        285.
        2018.04 구독 인증기관·개인회원 무료
        The understanding of water vapor sorption and equilibrium in food samples is crucial in the formulation of foods and in their storage stability. In this study, the moisture sorption isotherms of yacon powder was measured by using gravimetric method at 25℃, 35℃, and 45℃ under the relative humidity ranging from 11% to 75%, and nine different isotherm models were used to fit the experimental data and to analyze water vapor sorption on yacon powder. The experimental results showed that water vapor sorption for yacon powder followed a type III shape over the humidity range. The BET monolayer moisture contents values were slightly higher than the values predicted by the GAB model. The monolayer moisture content increased slightly as temperature increased. The surface areas for monolayer moisture sorption decreased with increasing temperature and blanching reduced these values. Through quantifying the relative percentage error (E), coefficient of determination (R2), standard error (SE), and root mean square (RMS) of the isotherm models relative to data, Halsey model was identified to be the best-fitting isotherm to describe the water sorption process in yacon powder.
        286.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고추는 한국에서 매우 중요한 양념 중 하나이다. 하지만 수입 고춧가루와 다진 양념(다대기)에 부과되는 관세율(45%/270%)의 차이로 인해, 다진 양념이 수입된 후, 건 조 및 분쇄 과정을 거쳐 고춧가루로 제작되고 있는 실정 이다. 본 연구에서는 종 특이 PCR 기술과 whole-genome amplification 방법을 접목하여 고춧가루(N=45) 및 다진 양 념(N=5) 제품의 사용원료(고추, 마늘, 양파, 파, 생강)를 분 석하였다. 모니터링 결과, 39개 고춧가루 제품은 표시사항 을 준수하였으며, 6개 고춧가루 및 5개 다진 양념 제품은 제조 기준을 충족시키지 못했다. 따라서 분석 제품의 22% 가 표시사항을 준수하지 못한 것으로 밝혀졌으며, 본 연구에 사용한 분석 방법은 고춧가루 제품에 사용된 원료 분석에 적합한 방법임을 입증하였다.
        4,000원
        287.
        2018.04 구독 인증기관·개인회원 무료
        The goal of this study was to determine moisture sorption isotherms of fermented sea tangle powder (FSTP) at 4 °C, 25 °C, and 37 °C by using the static gravimetric technique in a water activity (aw)rangeof0.11to0.93andtheyexhibittypeIII behavior, typical of food products. At constant aw, an equilibrium moisture content (EMC) decreased with increasing temperature. The EMC increased with increasing aw at constant temperature. These moisture sorption isotherms have been fitted using eight different mathematical models. The Guggenheim-Anderson-de Boer (GAB) model presents the best fit in describing equilibrium moisture content and water activity relationships for the FSTP over the entire range of temperatures. Isosteric heat of sorption (IHS) was determined from the equilibrium sorption data using the Clausius-Clapeyron equation. The IHS decreased from 61.68 to 48.70 kJ/mol with increasing the EMC from 0.14 to 3.22 g/g dry basis, approaching the latent heat of vaporization of pure water (, 45.71 kJ/mol). The obtained IHS indicating intermolecular attractive forces between the moisture vapor and sorption sites is an important factor to predict the drying and storage processes for the FSTP.
        288.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a relatively effective process is used to sterilize Escherichia coli on the surface of micro-sized calcium citrate powder using nitrogen and argon as process gases in a low-temperature vacuum plasma treatment. The purpose of this study is to confirm and to introduce the effectiveness of homogeneous surface treatment for the sterilization of fine inorganic powder by the rotatable low-temperature RF plasma system designed by ourselves. The results of the test using 3M petrifilm showed that there were no remarkable spots in the case of the surface of plasma treated powder, whereas the untreated powder showed many blue spots, which indicating that the E. coli was alive. After 5 days, in the same samples, the blue spots were seen to be larger and darker than before, while the plasma-treated powder showed no changes. The results from FE-SEM analysis showed that the E. coli was damaged and/or destroyed by reactive species generated in the plasma space, resulting in the E. coli being sterilized. Furthermore, the sterilization effects according to the selected parameters (N2 and Ar; flow rate 30 and 50 sccm) adapted in this study were mutually similar, regardless of such different process parameters, and this indicates that homogeneous treatment of powder surfaces could be more effective than conventional methods. Therefore, the plasma apparatus used in this study may be a practical method to use in a powerful sterilization process in powder-type food.
        4,000원
        289.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the quality characteristics of Yanggaeng prepared with different concentrations of mealworm powder: 0, 1, 2, and 3%. Regarding the proximate composition, moisture, crude lipid and ash contents showed no significant differences among groups, while crude protein contents increased as the mealworm powder increased. The value of lightness (L) and yellowness (b) were higher in 3% added groups than those of control groups. Consumer acceptance test showed that no significant differences between the controls and added groups were observed in color, smell, taste and overall acceptability. The total polyphenol content ranged from 19.87 to 51.37 mg GAE/100 g, exhibiting the increase with increasing mealworm powder level. DPPH radical scavenging activity and reducing power increased as the amount of mealworm powder increased. In conclusion, it is suggested that mealworm powder can be incorporated into Yanggaeng up to 3% without affecting the sensory quality of Yanggaeng.
        4,000원
        290.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to determine the optimal storage conditions by examining the effects of the storage conditions on the quality of red pepper powder during storage in households. Red pepper powder was stored at room temperature (20oC), refrigeration (2 and -1oC) and frozen (-5 and -20oC) for 3, 6, 9 and 12 months. The ASTA color value, capsanthin content and redness (a*) of the red pepper powders stored at -5 and -20oC were not decreased significantly depending on the storage temperatures until 9 months. The pH of red pepper powder stored at 20oC decreased significantly until 9 months and increased at 12 months. The microbiological quality of the red pepper powder stored at -5 and -20oC was more stable during long-term storage. In the sensory evaluation of red pepper powder stored under all conditions, the overall freshness, redness, hot flavor, moisture release, and edibility decreased with increasing storage period from the control to 12 months. Moisture release increased from 3 months to 12 months. Overall, red pepper should be stored at low temperatures (2 , -1oC) for up to 6 months, and frozen (≥ -5oC) for 6 to 9 months. The optimal temperature for long-term storage (≥9 months) was -20oC.
        4,000원
        291.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This purpose of this study is to analyze the effect to autogenous shrinkage of the top-layer material of a two-lift concrete pavement mixing both silica fume and polymer powder. METHODS: The bottom-layer of a two-lift concrete pavement was paved with original portland cement (OPC) with a 20~23 cm thickness. Additionally, the top-layer which is directly exposed to the environment and vehicles was paved with a high-performance concrete (HPC) with a 7~10 cm thickness. These types of pavements can achieve a long service life by reducing joint damage and increasing the abrasion and scaling resistance. In order to integrate the different bottom and top layer materials, autogenous shrinkage tests were performed in this study according to the mixing ratio of silica fume and polymer powder, which are the admixture of the top-layer material. RESULTS: Autogenous shrinkage decreased when polymer powder was used in the mix. Contrary to this, autogenous shrinkage tended to rise with increasing silica fume content. However, the effects were not significant when small amounts of polymer powder were used (3% and 11%). CONCLUSIONS : The durability and compressive strength increase when silica fume is used in the mix. The flexural strength considerably increases and autogenous shrinkage of concrete decreases when polymer powder is used in the mix. As seen from above, the proper use of these materials improves not only durability, but also autogenous shrinkage, leading to better shrinkage crack control in the concrete.
        4,000원
        292.
        2018.04 구독 인증기관·개인회원 무료
        The mature silkworms of Bombyx mori L. have recently been regarded as a potential health supplement due to gaining their edibility for humans via a newly-developed steaming method by the Rural Development Administration in Korea. This study was conducted to investigate the effects of a larval powder of steamed mature silkworms (SMSP) on hair growth/loss in vivo in mice. Topically applied SMSP showed potent hair growth promoting activity. SMSP-treated mice showed increase in hair weight significantly compared with control mice which were not treated with SMSP. Orally administered SMSP also showed hair growth promoting activity, which was lower than that when applied topically. By elucidating the hair loss preventing activity of SMSP, this study will be helpful to increase incomes for sericultural farm households in Korea.
        293.
        2018.04 구독 인증기관·개인회원 무료
        Silkworms, Bombyx mori L., have been traditionally used as an oriental medicine to manage diverse pathological conditions including dermatological problems in East Asia, in addition to the use of their cocoons for making fabrics. The “mature” silkworms of B. mori have recently been regarded as a potential health supplement due to gaining their edibility for humans by a newly-developed steaming method. Therefore, the present study was conducted to investigate the effects of a larval powder of steamed mature silkworms (SMSP) on skin pigmentation and melanogenesis. Orally administered SMSP of pistachio cocoon strain significantly and reduced abnormal pigmentation caused by ultraviolet B on the murine dorsal skin. SMSP also showed a potential anti-melanogenic efficacy in modulating UVB-induced melanogenesis.
        294.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cu-Fe alloys (CFAs) are much anticipated for use in electrical contacts, magnetic recorders, and sensors. The low cost of Fe has inspired the investigation of these alloys as possible replacements for high-cost Cu-Nb and Cu-Ag alloys. Here, alloys of Cu and Fe having compositions of Cu100-xFex (x = 10, 30, and 50 wt.%) are prepared by gas atomization and characterized microstructurally and structurally based on composition and powder size with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Grain sizes and Fe-rich particle sizes are measured and relationships among composition, powder size, and grain size are established. Same-sized powders of different compositions yield different microstructures, as do differently sized powders of equal composition. No atomic-level alloying is observed in the CFAs under the experimental conditions.
        4,000원
        295.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        296.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One-dimensional rutile TiO2 is an important inorganic compound with applicability in sensors, solar cells, and Li-based batteries. However, conventional synthesis methods for TiO2 nanowires are complicated and entail risks of environmental contamination. In this work, we report the growth of TiO2 nanowires on a Ti alloy powder (Ti-6wt%Al- 4wt%V, Ti64) using simple thermal oxidation under a limited supply of O2. The optimum condition for TiO2 nanowire synthesis is studied for variables including temperature, time, and pressure. TiO2 nanowires of ~5 μm in length and 100 nm in thickness are richly synthesized under the optimum condition with single-crystalline rutile phases. The formation of TiO2 nanowires is greatly influenced by synthesis temperature and pressure. The synthesized TiO2 nanowires are characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM).
        4,000원
        297.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to evaluate the quality characteristics of functional Dasik prepared with a mixture of freeze-dried mealworm (Tenebrio molitor) powder and dried pollack powder along with assessment of the general and fatty acid compositions of mealworms. General compositions, except for moisture content of freeze-dried mealworm powder, were higher than those of raw mealworms. The ratios of saturated fatty acids and unsaturated fatty acids of freeze-dried mealworm powder and raw mealworms were 1:3.31 and 1:3.19, respectively. Amounts of oleic acid, which was the most abundant among unsaturated fatty acids, of freeze-dried mealworm powder and raw mealworms were 41.12 and 37.84%, respectively. For color values, greater content of freeze-dried mealworm powder in functional Dasik resulted in lower L and b scores, whereas a value increased. In the case of mechanical properties, greater content of freeze-dried mealworm powder resulted in significant reduction of hardness, chewiness, and gumminess. In the case of sensory evaluation, color, taste, and overall quality of DPMD50, which was prepared with a 1:1 ratio of freeze-dried mealworm powder and dried pollack, were the highest. It was concluded that DPMD50 is a nutritious combination of edible insects and fish for protein fortification for growth and the elderly.
        4,000원
        298.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to expand the application of oxide dispersion-strengthened (ODS) steel, a composite material is manufactured by adding mechanically alloyed ODS steel powder to conventional steel and investigated in terms of microstructure and wear properties. For comparison, a commercial automobile part material is also tested. Initial microstructural observations confirm that the composite material with added ODS steel contains i) a pearlitic Fe matrix area and ii) an area with Cr-based carbides and ODS steel particles in the form of a Fe-Fe3C structure. In the commercial material, various hard Co-, Fe-Mo-, and Cr-based particles are present in a pearlitic Fe matrix. Wear testing using the VSR engine simulation wear test confirms that the seatface widths of the composite material with added ODS steel and the commercial material are increased by 24% and 47%, respectively, with wear depths of 0.05 mm and 0.1 mm, respectively. The ODS steel-added composite material shows better wear resistance. Post-wear-testing surface and cross-sectional observations show that particles in the commercial material easily fall off, while the ODS steel-added material has an even, smooth wear surface.
        4,000원
        299.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study on the decolorization method of salt-fermented anchovy sauce using activated carbon was carried out. The anchovy sauce filtered with a diatomaceous membrane after heating at 85℃ for 20 min was reacted with 3.0% (w/w) activated carbon with pH 4.5 at 55℃ for 2 hr. The color difference value and turbidity related to the decolorizing effect showed excellent improvement results with a difference of 23% and 88%, respectively. The overall taste and color preference of decolorized anchovy sauce were significantly increased in shrimp sauce by 0.4-0.5 points (p<0.05). In order to minimize the precipitation of amino acid during storage, 1% silicon dioxide or gelatin was mixed and filtered after the activated carbon reaction. Turbidity, as index of sedimentation, was improved by 15% at 30℃ for 2 weeks. The recycle system with activated carbon coated membrane filter reduced the processing time and cost on decolorization of anchovy sauce. When the concentrated anchovy sauce was recirculated, the amount of total protein as an indicator of taste compounds was increased by 125%, which is 1.8% compared to the conventional 0.8%, indicating that it is highly useful as a liquid seasoning.
        4,000원
        300.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The pH, acidity, viscosity, viable cell counts of lactic acid bacteria, and Hunter color value of yoghurt and also over-run and melting-down of yoghurt ice cream added with rice or puffed rice powder in instead of sugar were investigated. For the pH of yoghurt and ice cream, the control’s was higher than others’. The pH of rice powder and short grain was higher than that of puffed and long rice powders, respectively. Yoghurt acidity was consistent with the pH. Higher viscosity of yoghurt and over-run of ice cream were observed in the puffed rice powder with more gelatinization and the short rice powder with more amylopectin. Yoghurt and ice cream of the long rice powder showed higher viable cell counts than others. Lower Hunter “L” and “a” values of the puffed rice powder may be due to high temperature and pressure. Lower melting-down of higher over-run samples (p<0.05) might be caused by air insulation. Rice powder and puffed rice powder could be a good substitute for table sugar in yoghurt and ice cream production.
        4,000원