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1.
L.J. Espinoza-Pérez S. Esquivel-Medina E. López-Honorato 《Ceramics International》2021,47(11):15527-15532
The influence of the microstructure on the corrosion rate of three monolithic SiC samples in FLiNaK salt at 900 °C for 250 h was studied. The SiC samples, labeled as SiC-1, SiC-2, and SiC-3, had corrosion rates of 0.137, 0.020, and 0.043 mg/cm2h, respectively. Compared with grain size and the presence of special grain boundaries (i.e., Σ3), the content of high-angle grain boundaries (HAGBs) appeared to have the strongest influence on the corrosion rate of SiC in FLiNaK salt, since the corrosion rate increased six times as the concentration of high-angle grain boundaries increased from 19 to 32% for SiC-2 and SiC-1, respectively. These results stress the importance of controlling the content of HAGBs during the production process of SiC. 相似文献
2.
Macintosh Katrina A. McDowell Richard W. Wright-Stow Aslan E. Depree Craig Robinson Guy M. 《Nutrient Cycling in Agroecosystems》2021,120(2):121-129
Nutrient Cycling in Agroecosystems - Reducing agriculturally derived diffuse contaminant losses (via non-point sources) from land to water has proven difficult for decades. Owing to the diversity... 相似文献
3.
Wireless Personal Communications - A GPS spoofing attack broadcasts counterfeit signals to resemble standard GPS satellite signals to take control of the correlation peaks of GPS signals to force... 相似文献
4.
5.
Dr. Elena Petit Dr. Lluís Bosch Prof. Anna M. Costa Ignacio Rodríguez-Izquierdo Dr. Daniel Sepúlveda-Crespo Prof. M. Angeles Muñoz-Fernández Prof. Jaume Vilarrasa 《ChemMedChem》2021,16(14):2217-2222
Amides from indole-3-glyoxylic acid and 4-benzoyl-2-methylpiperazine, which are related to entry inhibitors developed by Bristol-Myers Squibb (BMS), have been synthesized with aliphatic chains located at the C7 position of the indole ring. These spacers contain an azido group suitable for the well-known Cu(I)-catalyzed (3+2)-cycloaddition or an activated triple bond for the nucleophilic addition of thiols under physiological conditions. Reaction with polyols (β-cyclodextrin and hyperbranched polyglycerol) decorated with complementary click partners has afforded polyol-BMS-like conjugates that are not cytotoxic (TZM.bl cells) and retain the activity against R5-HIV-1NLAD8 isolates. Thus, potential vaginal microbicides based on entry inhibitors, which can be called of 4th generation, are reported here for the first time. 相似文献
6.
Claudia Paredes Francisco J. Martínez-Vázquez Hamada Elsayed Paolo Colombo Antonia Pajares Pedro Miranda 《Journal of the European Ceramic Society》2021,41(1):892-900
Bioactive ceramic scaffolds for bone regeneration consisting of a three-dimensional mesh of interpenetrating struts with square section were fabricated via Digital Light Processing (DLP). The ability of the technique to manufacture 3D porous structures from β-tricalcium phosphate (β-TCP) powders with different dimensions of struts and pores was evaluated, identifying the possibilities and limitations of the manufacturing process. Small pore sizes were found to seriously complicate the elimination of excess slurry from the scaffold’s innermost pores. The effect of the strut/pore size on the mechanical performance of the scaffolds under compressive stresses was also evaluated, but no significant influence was found. Under compressive stresses, the structures resulted weaker when tested perpendicularly to the printing plane due to interlayer shear failure. Interlayer superficial grooves are proposed as potential failure-controlling defects, which could also explain the lack of a Weibull size effect on the mechanical strength of the fabricated DLP scaffolds. 相似文献
7.
Kyle L. Covington Alexander K. Goroncy Teresa E. Lehmann Zuhao Kou Heng Wang Vladimir Alvarado 《American Institute of Chemical Engineers》2021,67(2):e17074
Microtomography (μCT) and nuclear magnetic resonance (NMR) have been used to characterize porous media for decades. Magnetic resonance imaging (MRI) enables direct visualization of pore architecture and many pulse sequences exist. In this work, we tested the MRI pulse sequence Zero Echo Time (ZTE) to study sandstone and carbonate for its ability to address short relaxation times. We aimed at resolving two fluid conduit scales, that is, pores and fractures. In this research, we study tighter porous systems than those previously reported using ZTE. Additionally, pore cluster analysis (PCA), combined with ZTE, can be used to analyze pore-fracture connectivity of relatively large core plugs. We show that ZTE can resolve two-scale pore systems simultaneously, that is, fractures and pores. By combining time-domain NMR pore-size analysis and PCA, we show that careful selection of resolution is necessary to understand transport in porous media. 相似文献
8.
E.N. Lysenko V.A. Vlasov A.V. Malyshev E.A. Sheveleva A.P. Surzhikov 《Ceramics International》2021,47(17):23935-23941
The effect of dry and wet ball milling of LiFe5O8 ferrite powder on the microstructure and electromagnetic properties of ferrite ceramics was studied using XRD analysis, scanning electron microscopy, dilatometry, thermogravimetry, calorimetry, and measurement of specific magnetization and electrical resistance. The sintering temperature was 1050 °C; the sintering time was 2 h. It was found that ferrite fabricated from dry-milled powder exhibits an ordered α-LiFe5O8 phase with bulk density of 91%. Its saturation magnetization and Curie temperature are 55 emu/g and 628°С, respectively. Specific electrical resistance is 4?106 Ω cm. Wet milling in isopropyl alcohol causes formation of a disordered β-LiFe5O8 phase. Ceramics produced by this method shows higher bulk density (97%) and low porosity, and an order of magnitude lower resistivity. Its saturation magnetization and Curie temperature are 51 emu/g and 607°С, respectively. 相似文献
9.
Mechanical properties and thermal shock in thin ZrO2–Y2O3–Al2O3 films obtained by the sol-gel method
Antonio Díaz-Parralejo M. Ángeles Díaz-Díez José Sánchez-González Antonio Macías-García Juan Pablo Carrasco-Amador 《Ceramics International》2021,47(1):80-86
Thin multilayer coatings of ZrO2–Y2O3–Al2O3 were prepared using the sol-gel method and dip-coating technique in order to advance in the study of what influence the incorporation of Al2O3 has on films of Y2O3-doped ZrO2, investigating its role in the synthesis of the solutions and in the characteristics and properties of the coatings. After the characterization of the solutions used in the process, the microstructure of the films was studied and their mechanical behaviour and resistance to thermal shock were determined so as to optimize the characteristics and functionality of these coatings. With increased alumina content, 3YSZ-Al2O3 (20 mol%), the cubic phase of the zirconia disappeared completely at the sintering temperature used (700 °C), resulting in the tetragonal phase with Al in solution. There was also a decrease in the coatings' hardness and Young's modulus, and an increase in toughness and resistance to thermal shock. These results allow guidelines to be established for the design of multilayer structures that are, tougher, more resistant, and have improved surface properties. 相似文献
10.
Aubrey Makofane David E. Motaung Nomso C. Hintsho-Mbita 《Ceramics International》2021,47(16):22615-22626
The extensive occurrence of textile and pharmaceutical contaminants and their metabolites in water systems has posed significant concerns regarding their possible threat to human health and the environmental system. As a result, herein ZnFe2O4 nanoparticles were synthesized through the use of Monsonia burkeana plant extract. The synthesized nanoparticles were characterized using XRD, FTIR, UV–vis, SEM, EDS, TGA, BET, PL, EPR and VSM. XRD showed that the crystalline structure of ZnFe2O4 nanoparticles with a calculated crystal size of 25.03 nm was formed. FT-IR confirmed the characteristic functional groups contained within the M. burkeana plant were deposited on the formed ferrite nanoparticles. BET analysis confirmed the mesoporous nature of ZnFe2O4 with an average pore diameter of 31.6 nm. Morphological studies demonstrated that the formed nanoparticles had spherical as well as rod-like shapes. ZnFe2O4 photocatalyst illustrated that it may be effortlessly detached by an external magnetic field. The optimum conditions for the 99.8% removal of Methylene Blue was obtained at pH12, within 45min and at the optimum dosage of 25 mg of the catalyst. The as-prepared ZnFe2O4 nanoparticles proved to be easily separated and recycled, and remained efficient even after 5 reuses, proving that the material is highly stable. The ROS studies also demonstrated that electrons are the main factors contributing to the degradation of MB. Upon testing the photocatalytic performance of the sulfonamide antibiotic, sulfisoxazole in water showed a degradation of 67%. This study has shown that these materials can be used in targeting textile and pharmaceutically polluted water. 相似文献