Ultrasonic agitation is a very efficient method for deagglomeration and dispersion of ceramic slurries (alumina and barium titanate). The influence of parameters such as acoustic power, temperature, and treatment duration on the dispersion efficiency has been studied. For

In reducing the high operating temperatures (≥800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (≤600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the mai...

Density functional theory calculations are used to investigate the energetics of protons crossing triple phase boundaries based on a metal catalyst, Pd or Ni, and barium zirconate. Our calculations show that the proton transfer reaction at these interfaces is controlled by the terminal layer of the electrolyte in contact with the metallic and gas phases. The hydrogen spilling process onto the e...

The control of crystallization of praseodymium barium copper iron oxide, an intermediate temperature solid oxide fuel cell cathode material, has been demonstrated for the first time using a biotemplated sol-gel synthesis technique. The results obtained showed significant improvement in purity, synthesis time, surface area and simplicity over that previously reported.

The dc and ac electrical properties of PTC barium titanate ceramics were measured in the temperature range from 30 to 450°C. The Heywang's model alone is not sufficient to perform a quantitative analysis of the results. The heterogeneity of the system is taken into account.

Dielectric materials with high permittivity are strongly demanded for various technological applications. While polarization inherently exists in ferroelectric barium titanate (BaTiO3), its high permittivity can only be achieved by chemical and/or structural modification. Here, we report the room-temperature colossal permittivity (~760,000) obtained in xNd: BaTiO3 (x = 0.5 mol%) ceramics derive...

I read Hans Rekers’ 2013 letter about removal of a fractured Nexplanon implant with interest, as I have in my practice come across a Nexplanon implant that was completely fractured through its core and sheath in two discrete locations (Figure 1), a scenario that I had not encountered previously. A 44-year-old woman had had a Nexplanon implant inserted 3 years previously. She was amenorrhoeic fo...

A new rigid tritopic phosphonic ligand, 2,4,6-tris(4-phosphonophenyl)pyridine (H6L), was synthesized and used to assemble isostructural barium (1) and strontium (2) phosphonate metal organic frameworks that exhibit fully reversible and selective water-dependent fluorescence red-shift at room temperature.

We describe the experimental measurement of phase-conjugate reflectivity versus various ratios of input-beam intensities in photorefractive barium titanate and strontium barium niobate crystals. The experimental results are compared with the theoretical prediction from the coupled-wave theory. Three different methods to measure the nonlinear coupling constant of the crystal are also presented a...

background and aims. radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. digital subtraction radiography has recently been used to improve the diagnostic quality of these lesions. the purpose of this study was to compare the ca...