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In this work, a type of glass foam for artificial floating island applications was produced from solid waste glass by using powder sintering technology at a low temperature using Li 2 CO 3 as the foaming agent. The effects of Li 2 CO 3 content and foaming temperature on the microstructure, crystalline phase composition and macroscopic properties of glass foams were investigated. The results showed that the optimal glass foam with homogeneous porous structure, low bulk density (0.32 g/cm 3 ), and high compressive strength (2.64 MPa) could be prepared under conditions of 7 wt% Li 2 CO 3 content and sintering at 750 °C. In addition, the water and acid resistance experiments for the obtained optimized samples indicated that the final product possessed excellent chemical stability. [ABSTRACT FROM AUTHOR]

The role of rare earth oxides (CeO 2 and Y 2 O 3 ) in the microstructures and properties of vitrified diamond composites was comprehensively investigated. The results revealed that the incorporation of appropriate amounts of CeO 2 or Y 2 O 3 could not only decrease the refractoriness but also increase the fluidity of vitrified bonds. In comparison with composites containing Y 2 O 3 , composites doped with CeO 2 possessed lower porosity and coefficient of thermal expansion. When adding 4 wt.% rare earth oxides, the flexural strength and thermal conductivity of composites containing CeO 2 simultaneously achieved the maximums, 102.5 MPa and 4.37 W·m − 1 ·k − 1 , respectively, which highly surpassed the values of composites without additives and composites containing Y 2 O 3 . In general, the difference of CeO 2 and Y 2 O 3 on properties of composites was mainly attributed to the different accumulation effects of corresponding cations. CeO 2 played greater impact than Y 2 O 3 on the properties of vitrified diamond composites. [ABSTRACT FROM AUTHOR]

The microstructures and properties of vitrified diamond composites, which are composed of diamond grains and vitrified bonds with varying Cu and Zn doping amounts, were comprehensively investigated in this work. The results including TG curves indicated that compared with Zn, Cu powders were more beneficial to prevent the oxidation of diamond. Both of them could consume oxygen and be oxidized to CuO or ZnO, which would enter into the glass network but not damage the structure. Hence, the vaporization of metals, especially Zn, would remain tiny voids and the lower refractoriness could easily lead the glass to foam. The incorporation of Cu or Zn in appropriate amounts (4 wt.%) not only decreased the refractoriness of vitrified bonds but also increased the wettability between diamond grains and vitrified bonds. The flexural strength of the diamond composites incorporating 4 wt.% Cu could reach 60.35 MPa, which increased by about 19.6% than the basic diamond composite and its growth rate was also higher than the value of composites containing 4 wt.% Zn (7.8%). In general, the addition of Cu played greater role than Zn on the protection of diamond grains and properties of vitrified diamond composites. [ABSTRACT FROM AUTHOR]

We propose a Bayesian hierarchical model for multiple comparisons in mixed models where the repeated measures on subjects are described with the subject random effects. The model facilitates inferences in parameterizing the successive differences of the population means, and for them, we choose independent prior distributions that are mixtures of a normal distribution and a discrete distribution with its entire mass at zero. For the other parameters, we choose conjugate or vague priors. The performance of the proposed hierarchical model is investigated in the simulated and two real data sets, and the results illustrate that the proposed hierarchical model can effectively conduct a global test and pairwise comparisons using the posterior probability that any two means are equal. A simulation study is performed to analyze the type I error rate, the familywise error rate, and the test power. The Gibbs sampler procedure is used to estimate the parameters and to calculate the posterior probabilities. [ABSTRACT FROM AUTHOR]

Vitrified bonded SiC composite ceramics were prepared using a simple powder blending, forming, and sintering process. The effect of SiC particle size on the mechanical and dielectric properties of vitrified bonded SiC composite ceramics was investigated. Vitrified bonds wet and coat SiC particles during sintering and form continuous bonding networks upon cooling. The vitrified bonds render the ceramics high flexural strength and act as impedance mismatching modification layer between SiC particles and air. With varying SiC particle size, the microstructure, and properties of the vitrified bonded SiC composite ceramics change accordingly and at 7 μm, it reaches optimal microstructure, a highest flexural strength of 67.85 MPa and highest reflection loss. However, the dielectric loss of composite ceramics decreases as the SiC particle size increases. [ABSTRACT FROM AUTHOR]