Micelle formation and adsorption at the Ti02 interface of a series of polystyrene-polythylene oxide(PS-PEO) block copolymer in aqueous solution was studied using fluorescence probing and small-angle X-ray methods. Further, the stability of aqueous Ti02 dispersion in the presence of copolymer was investigated by microelectrophoresis, optical density and sedimentation measurements. The dissolution of pyrene as fluorescent probe in aqueous surfactant solution leads to a slow decrease of the I1/I3 ratio, as the copolymer concentration increase; I1 and I3 are respectively the intensities of the first and third vibrionic peaks in the pyrene fluorescence emission. The behaviour was due to the characteristics of the copolymers and/or to the copolymer association efficiency in water. Moreover, the adsorption at the plateau level increases with decreasing PEO until chain length. The zeta potential of TiO2 particles decreases with increasing copolymer concentration and reaches a plateau value. Finally, stabilization using block copolymers was more effective with samples having higher weight fractions of PS block.

Spark-Plasma Sintering(SPS) is one of the new sintering methods which takes advantages both inconventional pressure sintering and electric current sintering. It is known that SPS is very effective for the densification of hard-to-sinter materials like refractory metals, intermetallic compounds, glass and ceramics without grain growth. However, a clear explanation for sintering mechanism and an experimental evidence for the formation of weak plasma during SPS are not given yet. In this study, fundamental study on sintering behavior and mechanism of SPS was investiged. For this study, various spherical Fe powders were prepared such as as-received, as-reduced, and as-oxidized and then sintered by SPS facility. In order to confirm the surface cleaning effect during SPS neck region and fracture surface of sintered body was observed and analyzed by SEM/EPMA. Densification behavior was analyzed from the data of deflection along the pressure axis. Some specimens were additionally produced by Hot Pressing and the results were compared with those of SPS.

The synthesis and characteristics of W-Ni-Fe nanocomposite powder by hydrogen reduction of ball milled W-Ni-Fe oxide mixture were investigated. The ball milled oxide mixture was prepared by high energy attrition milling of W blue powder, NiO and for 1 h. The structure of the oxide mixture was characteristic of nano porous agglomerate composite powder consisting of nanoscale particles and pores which act as effective removal path of water vapor during hydrogen reduction process. The reduction experiment showed that the reduction reaction starts from NiO, followed by and finally W oxide. It was also found that during the reduction process rapid alloying of Ni-Fe yielded the formation of -Ni-Fe. After reduction at 80 for 1 h, the nano-composite powder of W-4.57Ni-2.34Fe comprising W and -Ni-Fe phases was produced, of which grain size was35nm for W and 87 nm for -Ni-Fe, respectively. Sinterability of the W heavy alloy nanopowder showing full density and sound microstructure under the condition of 147/20 min is thought to be suitable for raw material for powder injection molding of tungsten heavy alloy.

본 연구에서는 부분산화한 Ti 분말을 첨가한 BaTiO3계 세라믹스를 진공중 1350˚C에서 1 h 소결하여 제조하였다. 공기중 가열후 전기적 성질과 미세조직에 미치는 부분산화한 Ti분말 첨가량의 효과를 조사하였다. 그 결과, 5~7vol%의 부분산화한 Ti분말을 첨가한 반도성 BaTiO3계 세라믹스는 비정항의 변화크기가 105이상인 우수한 PTCR 특성을 나타내었고 또한, 고다공질과 미립화된 조직을 얻을 수 있었다. 5 vol%의 부분산화한 Ti 분말을 첨가한 BaTiO3계 세라믹스의 상대밀도와 입도는 각각 54%, 1.3 μm였다. 부분산화한 Ti 분말의 첨가에 의한 BaTiO3계 세라믹스의 PTCR 특성 발현은 입계에서의 산소 흡착에 기인하였는데, 이는 Heywang모델로써 설명할 수 있었다.

The synthesis of W-l5wt%Cu nanocomposite powder by hydrogen reduction of ball milled W-Cu oxide mixture was investigated in terms of powder characteristics such as particle size, mixing homogeneity and micropore structure. It is found that the micropores in the ball milled oxide (2-50 nm in size) act as an effective removal path of water vapor, followed by the formation of dry atmosphere at reaction zone. Such thermodynamic condition enhances the nucleation of W phase but suppresses the growth process, being in favor of the formation of W nanoparticles (about 21 nm in size). In addition, the superior mixing homogeneity of starting oxide mixture turned out to Play a significant role for forming extraordinary chemical homogeneity of W-l5wt%Cu nanocomposite powder.

The effect of vacuum annealing on the oxidation behavior of milled WC-15%Co powder mixture has been studied. A cobalt component in the milled powder mixture was oxidized preferentially above 175 in air. The specimens showed a steady increase in weight at 175 but did constant weight followed by rapid increase in specimen weight at the beginning above 20. Oxidation of the milled powder mixture was significantly suppressed by vacuum annealing at 30 for 10 h. Suppression of oxidation by vacuum annealing and different oxidation behaviors of the milled powder mixture between 175 and 20, were attributed to removal of strain energy stored in the cobalt powder during vacuum annealing or oxidation treatment above 20. The role of stored strain energy on oxidation of milled WC-15%Co powder mixture was proved by X-ray diffraction method and differential thermal analysis.

The yields of solvent fractions of irradiated red ginseng powder were increased in the order of petroleum ether(PE)$lt;diethyl ether(DE)$lt;ethyl acetate(EA)$lt;n-butanol (BU)$lt;aqueous fraction(AQ), and did not show any changes in fraction yields by irradiation dose levels. Inhibition activities of lipid peroxide formation were increased in the order of AQ$lt;BU $lt;PE$lt;EA$lt;DE. Inhibition activities of malonaldehyde formation were increased in the order of AQ≤BU$lt;EA$lt;PE$lt;DE. AQ fraction showed little effects on the antioxidative activity and all the activities of the samples did not changed by gamma irradiation. The reverse mutation assay using Salmonella typhunurium (TA98, TA100 and TA102) demonstrated that the nonirradiated and irradiated red ginseng powder extract did not have mutagenic activity (presence of S9 mix or not). The chromosomal aberration test in mammalian animal cell (Chinese hamster lung fibroblast, CHL) showed no significant increase in incidence of structural and numerical aberrations, comparing gamma-irradiated red ginseng powder extracts to nonirradiated red ginseng powder extract in the concentration of the sample producing cytotoxicity(presence of S9 mix or not). Therefore, gamma-irradiatied red ginseng powder (upto 10 kGy) could be safe on the genotoxic point of view.

본 연구는 잠재적인 생균제제 Lactobacillus plantarum P1201에 의한 유색 소립콩 분말 두유의 젖산발효 중 이화학적 특성, 총 페놀릭스와 이소플라본 함량 및 항산화 활성(DPPH와 ABTS 라디칼 소거활성 및 FRAP 환원력) 변화를 연구하였다. 콩 분말 두유의 발효 중 pH는 감소하였으나, 산도, 생균수 및 β-glucosidase 활성은 증가하였다. 총 이소플라본 함량은 풍산나물콩이 다른 유색 소립콩보다 함량이 높았다. 발효과정에서 배당체 이소플라본인 daidzin과 genistin 함량은 감소하였고 이에 상응하여 비배당체 이소플라본인 daidzein과 genistein 함량은 급격히 증가하였다. 특히, 발효 60시간 후 발효된 풍산나물콩 분말 두유의 daidzein과 genistein 함량은 87.37 μg/g and 51.29 μg/g으로 다른 시료들보다 함량이 가장 높았다. 총 페놀릭스 함량은 다른이 다른 유색 소립콩보다 함량이 높았다. 총 페놀릭스 함량은 색 소립콩 분말 두유의 젖산발효 중 0.44-2.92 mg/g(0 h)에서 1.79-3.03 mg/g(60 h)로 급격히 증가하였다. 끝으로, 발효된 콩 분말 두유는 DPPH와 ABTS 라디칼 소거활성 및 FRAP 환원력은 각각 28.7-40.6에서 90-95.3%, 25.1-42.3에서 51.4-82.8% 및 0.73-1.54에서 0.98-1.79(OD593nm)로 증가하였다. 발효된 콩 분말 두유는 유색 소립콩의 가치를 증대시킬 수 있다.

Bioremediation in situ is heavily dependent on the oxygenic environment which would privide the dwelling microorganism with sufficient oxygen. The situation could be easily resolved with supply of an Oxygen Releasing Compound (ORC). In this paper we prepared that sort of material out of oyster shell powder (mostly calcium carbonate) that prevails every shore areas of the country. We used two different oxidizing methods in the first step of the whole manufacturing process–conventional heating in a furnace and an ultrasound generator to obtain calcium oxide. Then that calcium oxide was further oxidized into calcium peroxide which may release oxygen under a moisturized condition. The oxygen releasing experiments were run to test the performance of our products, and to determine the gas kinetics during the experiments. Interestingly, calcium peroxide derived from ultrasound treatment was much more energy-effective as ORC than that from furnace heating although the heat derived process was better than that of ultrasound in terms of oxygen content and its releasing rate. We also found that most of the data collected from the gas releasing experiments fairly supported an ordinary 1st order kinetics to oxygen concentration, which shaped a sharp discharge of oxygen at the very early moment of each test.

Background: The flowering plant Hippophae rhamnoides L. has been used for many studies on fruit or leaf extracts. This study was conducted to investigate the development of a new cosmetic material from H. rhamnoides fruits and leaves that have by antioxidant, anti-inflammatory and wrinkle improvement activities. Methods and Results: The antioxidant abilities of H. rhamnoides extracts, including of a water-soluble fruit powder (FW), a fatsoluble fruit powder (FF), a supercritical extract of fruit by-product (BS), and a mixture of leaf and fruit (MIX), were investigated in vitro. A DPPH radical assay for antioxidant activity was performed for these fractions alongside assay to evaluate the total phenolic and flavonoid content (TPC and TFC). As expected, the MIX had the highest DPPH radical scavenging activity (RC50 = 10.27㎍/㎖), and the TPC and TFC also were highest in MIX (225.7 ㎎·GAE/g, and 25.18 ㎎·QE/g, respectively). Nitric oxide (NO) production in LPS-induced RAW264.7 cells was estimated and the results indicated an over 75% decrease of NO production in FF and MIX. In other assays, the highest elastase inhibitory activity was found in FW. Conclusions: These results revealed that H. rhamnoides extracts have a high potential for antioxidant, anti-inflammatory and antiwrinkle activities. H. rhamnoides products are suggested to be applied as the functional materials of cosmetic ingredients.

This study was conducted to investigate the effect of Lentinus edodes powder on the quality characteristics and antioxidant of rice cookies. The cookies for this experiment was made by 3 main ingredients including rice powder, flour, Lentinus edodes powder. The proportion of rice powder was fixed to 50% for the total amount of ingredients. The amount of reminded 2 ingredients (flour and Lentinus edodes powder) were varied. The amount of flour was decreased up to 38%, and the addition of Lentinus edodes powder was increased to 4%, 8% and 12%. Density of the dough, hardness, total polyphenol content, DPPH free radical scavenging activity, and reducing power increased with increasing Lentinus edodes powder content. Moisture content, pH of the dough, spread factor, loss rate, leavening rate, and L values of the cookies were decreased with increasing Lentinus edodes powder content. The result of consumer acceptance test revealed that there were no significant differences in smell, taste and overall acceptability, while the preference of color decreased as the amount of Lentinus edodes powder increased. To sum up, the cookies with 12% Lentinus edodes powder can produced the best results in terms of quality and antioxidant potential.

양배추 분말 첨가량을 0-15%로 달리하여 스펀지 케이크를 제조하고 물리적 품질특성, 항산화 활성, 관능적 특성 및 제조적성을 조사하였다. 물리적 품질특성은 양배추 분말 첨가량이 증가할수록 반죽의 비중, 굽기손실율은 증가하였고, 케이크 crumb과 crust의 색도, 부피지수, 비용적은 감소하였다. 대칭성지수, 균일성지수는 대조구와 유의적인 차이가 없었다. 케이크의 경도는 양배추 분말 첨가량이 증가할수록 증가하였고, 응집성은 감소하였으며 탄력성, 점착성, 부서짐성은 유의적으로 차이가 없었다. 케이크의 항산화 활성을 나타내는 총 폴리페놀 함량, DPPH 라디칼 소거능, 환원력 등은 양배추 분말 첨가량이 증가할수록 증가하였다. 관능평가에서 색상, 향미, 조직감은 대조구보다 양배추 분말 5-15% 첨가구가 유의적으로 낮은 선호도를 보였고 맛은 양배추 분말 5% 첨가구가 5.18로 가장 높은 선호도를 나타내었으며 전체적인 기호도는 10% 첨가구가 5.02로 가장 높게 나타났다. 전반적인 품질특성을 조사한 결과는 양배추 분말 5% 첨가구가 비중, 부피지수, 비용적, 경도, 응짐성 등이 대조구와 유사한 경향을 보였고 생리활성 증가로 인한 항산화 활성과 맛에서 대조구보다 우수한 결과를 나타내었다. 이상의 결과로 양배추 분말 첨가 스펀지 케이크 제조를 위한 양배추 분말의 첨가 범위는 5-10%가 적절한 것으로 판단되었으며, 최적 첨가량은 5%인 것으로 나타났다.

본 연구에서는 기능성이 밝혀져 있는 여주 분말을 첨가 하여 쌀누룩을 제조하고 이 누룩을 이용하여 막걸리를 제조 하였다. 여주 분말-쌀누룩(BMP-RN)은 BMP를 0, 0.5, 1.0 및 2.0%로 쌀에 첨가하여 제조하였고, 막걸리 발효가 진행 되는 동안 발효 특성, 미생물 특성 및 항산화 특성을 확인하 였다. 막걸리 발효 중 pH는 담금 직후(발효 0일째) 각각 4.52(0% BMP-RN), 4.93(0.5%), 4.80(1.0%) 및 4.88(2.0%)에 서 발효 7일째 4.15, 4.30, 4.57 및 4.77로 감소하였고, 이에 상응하여 총산은 0.60~0.78%에서 1.18-1.42%로 증가하였 다. 가용성 고형분은 발효 초기(0일째) 2.2~4.4 oBrix에서 발효 종기(7일째)8.6~9.3 oBrix로 증가하였고 알코올 함량 은 발효 종기 13.0%로 증가하였다. 한편, 수용성 phenolics 함량은 발효 0일째 각각 0.92~1.41 mg/mL에서 발효 종기(7 일째) 1.85~2.48 mg/mL로 증가하였고 이에 상응하여 DPPH 와 ABTS 라디칼 소거활성 및 FRAP 환원력은 각각 발효 0일째 46.95~70.04%, 55.33~74.13% 및 0.629~1.243에서 발 효 7일째 54.98~83.4%, 70.34~92.39% 및 0.964~1.455로 증 가하였다. 여주 분말 첨가 막걸리가 여주 분말 무첨가 막걸 리(일반 막걸리)보다 수용성 phenolics 및 항산화 활성이 높았다. 이 결과로 여주-쌀누룩을 이용하여 기능성 막걸리 제조가 가능할 수 있을 것으로 판단되었다.