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511.
Mst. Shamsun Nahar Kiyoshi Hasegawa Shigehiro Kagaya Shigeyasu Kuroda 《Science and Technology of Advanced Materials》2007,8(4):286-291
Fe-doped TiO2 particles responding to visible light were synthesized by impregnation and calcination method using TiO2 particle and Ti element, respectively. The optical and the chemical properties were characterized by measuring the X-ray diffraction (XRD) and UV-visible spectroscopy. The onset of absorption shifted to longer wavelengths on doping TiO2 by the calcination process, which showed a better response as compared to the impregnation method. The photocatalytic reactivity was evaluated by the degradation of phenol with impregnated Fe-doped (0.5% w/w in Fe) and calcined Fe-doped (FexTi1−xO2, x=0.005 (Fe/Ti molar ratio)) TiO2 separately in distilled and tap water. The characterization results have confirmed the advanced possibility of correlation between photoactivity and the special property of sulfur-containing calcined Fe-doped TiO2. In case of the coagulation of the undoped A-I and the Fe-doped B-I, the photoactivity showed a decrease due to the presence of natural electrolytes and due to the high pH of tap water, whereas in the case of the coagulation of calcined Fe-doped TiO2 prepared from sulfides (FexTiS2), the photoactivity showed an increase. In this study, highest catalytic activity was found to be strongly dependent both on catalyst structure and on the type of water used. 相似文献
512.
H. M. Song J. C. Kim J. H. Hong Y. B. Lee J. Choi J. I. Lee W. S. Kim J.‐H. Kim N. H. Hur 《Advanced functional materials》2007,17(13):2070-2076
The fabrication of transparent, flexible, and optically homogeneous magnetic composites containing ferrite (Fe3O4) nanoparticles, liquid crystals (LCs), and siloxane backbones is reported. The transparent magnets are achieved by covalently bonding LCs to the siloxane backbones and then linking them to dopamine‐functionalized ferrite nanocrystals. They exhibit simultaneous high transparency and strong magnetic properties. A remarkable feature of these films is that the surface morphology of the LC‐attached ferrite films can be tuned by an external magnetic field, demonstrating a striped surface in the direction of the field. We show that the LC‐attached film can act as an alignment layer to orient LCs, enabling the development of LC alignment surfaces on the basis of these nanomagnet–LC polymer composites. 相似文献
513.
Chatchai Rodwihok Korakot Charoensri Duangmanee Wongratanaphisan Won Mook Choi Seung Hyun Hur Hyun Jin Park Jin Suk Chung 《材料科学技术学报》2021,76(17):1-10
Functionalization of aniline molecules on zinc oxide(ZnO)nanoparticles is reported using a simple impregnation technique.Functionalized ZnO samples were systematically characterized based on mor-phology,surface and optical properties,and photocatalytic performance towards methyl orange(MO).Aniline functionalization increased the surface charge of the modified ZnO.Compared to pristine ZnO,the aniline-functionalized ZnO yielded faster photodegradation of MO,degrading 98.29% of MO in 60 min and superoxide radicals were the major species during the MO photodegradation reaction.These results indi-cate that the improvement of photocatalytic degradation could be attributed to opposite charge-induced surface adsorption.Hence,protonated amine as a positively charged molecule was expected to increase the surface adsorption of MO(as an anionic dye)on ZnO nanoparticles surfaces,thereby increasing their photocatalvtic degradation performance. 相似文献
514.
Application of a new portable microscopic somatic cell counter with disposable plastic chip for milk analysis 总被引:2,自引:0,他引:2
Moon JS Koo HC Joo YS Jeon SH Hur DS Chung CI Jo HS Park YH 《Journal of dairy science》2007,90(5):2253-2259
The somatic cell count (SCC) is one of the international standards for monitoring milk quality, and it is a useful indicator of mastitis. The current reference method for determining the SCC in raw milk is direct microscopic analysis, but this method requires well-trained staff to maintain its accuracy and reproducibility. To overcome these inconveniences, we developed a portable system (the C-reader system) that utilizes the capillary flow of a microfluidic chamber by surface modification of the hydrophilicity. The microfluidic technology of disposable microchips allows for low consumption of reagents, and a combination of ready-to-use reagents makes the daily work easier. The repeatability test of the C-reader using 10 composite bovine milk samples satisfied the recommended values for SCC equipment. In addition, an acceptable accuracy level of the natural logarithmic-transformed SCC [ln(SCC/1,000): ± 0.059 to 0.112] was achieved using composite raw milk samples and various somatic cell standard solutions from the American Eastern Laboratory and the Korean National Veterinary Research and Quarantine Service. After testing 875 composite milk samples, the C-reader showed a high correlation coefficient (R2 = 0.935 to 0.964) and a low mean difference value in log-transformed SCC (−0.088 to 0.004) compared with 3 automatic commercialized somatic cell counters (Fossomatic 4000, Somacount 150, and Somascope). In conclusion, the C-reader system is a new, easy-to-use automatic on-farm method with acceptable repeatability and accuracy for measuring SCC in large dairies and smaller laboratories. 相似文献
515.
516.
In order to investigate the influence of HCS on the hydrogen occupation site of Mg2Ni alloy, the thermal desorption technique has been applied to Mg2Ni hydride made by hydriding combustion synthesis (HCS). Mg2Ni was made under low temperature in a short time by the HCS compared to conventional melting process. At various initial hydride wt% from 0.91 to 3.52, the sample was heated to 623 K at a rate of 1.0 K/min. The starting temperature of the evolution of hydrogen goes higher as the initial hydride wt% increases. Only one peak is shown in the case of the small initial hydride wt%. But two peaks appeared with increasing initial hydride wt%. The activation energies obtained by the first and second peaks are 113.0 and 99.5 kJ/mol respectively. The two site occupation model by Darriet et al. was proved. The influence of HCS on the hydrogen occupation site of Mg2Ni alloy is nonexistent. 相似文献
517.
Merits of distributed medium access control specified by WiMedia Alliance such as distributed nature and high data rate make it a favorite candidate standard for high rate wireless personal area network. However, the current WiMedia MAC standard has not considered supporting Quality of Service (QoS) even though QoS parameters such as a range of service rates are provided to each traffic stream (TS). Therefore, we propose a fair and QoS-aware resource allocation method that provides a fair and maximized QoS for all TSs according to the current traffic load condition and differentiates SoQ among different QoS classes while guaranteeing fairness of SoQ within a QoS class in a fully distributed manner. Even in case that the traffic load varies, each device independently recognizes the changes and calculates fair and maximum allowable service rates for TSs. From the simulation results, it is proven that the proposed method achieves high capacity of TSs and fair QoS provisioning under various traffic load conditions. 相似文献
518.
519.
Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer that has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by API test. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the nonpathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by L. lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against nonpathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely destroyed by protease XIV. The inhibitory activities of lacticin BH5 were detected during treatments up to 100 degrees C for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. It demonstrated a typical bactericidal mode of inhibition against M. flavus ATCC 10240. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3 to 3.5 kDa, by the direct detection of bactericidal activity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 相似文献
520.
Chi-Sung Jeon Yong-Ha Jeong Sung-Tae Hong Md. Tariqul Hasan Huynh Ngoc Tien Seung-Hyun Hur Yong-Jai Kwon 《Journal of Mechanical Science and Technology》2014,28(2):499-504
Graphite/aluminum metal matrix composite (MMC) joints are successfully fabricated by friction stir spot welding (FSSW). During lap-joining processes of aluminum alloy sheets by FSSW, graphite/water colloid is applied between the tool shoulder and the upper plate. The Raman spectrum of the FSSW joint confirms that graphite/aluminum MMC is successfully induced in the stir zone. Quasi-static shear tests and micro hardness measurements of the FSSW joint also show that the strength and toughness of the joint are significantly improved by inducing graphite/aluminum MMC in the stir zone. The results of the present study suggest that the mechanical properties of structural components joined by spot welds can be easily enhanced by adopting MMC joints by FSSW, instead of changing the material or increasing the number of joints. 相似文献