“
“Temperature-dependent dielectric permittivity of 0.94(Bi1/2Na1/2) TiO3-0.06BaTiO(3) (BNT-6BT) lead-free piezoceramics was studied to disentangle the existing unclear issues over the crystallographic aspects and AICAR inhibitor phase stability of the system. Application of existing phenomenological relaxor models enabled the relaxor contribution to the entire dielectric permittivity spectra to be deconvoluted. The deconvoluted data in comparison with the temperature-dependent dielectric

permittivity of a classical perovskite relaxor, La-modified lead zirconate titanate, clearly suggest that BNT-6BT belongs to the same relaxor category, which was also confirmed by a comparative study on the temperature-dependent polarization hysteresis loops of both materials. Based on these results, we propose that the low-temperature dielectric anomaly does not involve any phase transition such as ferroelectric-toantiferroelectric.

Supported by transmission electron microscopy and X-ray diffraction experiments at ambient temperature, we propose that the commonly observed Selleck SBC-115076 two dielectric anomalies are attributed to thermal evolution of ferroelectric polar nanoregions of R3c and P4bm symmetry, which coexist nearly throughout the entire temperature range and reversibly transform into each other with temperature. (C) 2011 American Institute of Physics. [doi:10.1063/1.3645054]“
“Diesel exhaust is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to diesel exhaust

and diesel exhaust particles (DEP) have contributed to understanding health effects. Such acute exposure studies of healthy subjects to diesel exhaust and DEP demonstrate a pro-inflammatory effect in the lung and systemically but only at higher concentrations (with a threshold dose approximating PLX3397 order 300 mu g/m(3)). Unexpectedly, there appears to be a lack of an inflammatory response to diesel exhaust and DEP in asthmatic individuals. Controlled human exposure studies of cardiovascular effects show that, comparable to other particle-associated exposures, diesel exhaust has a capacity to precipitate coronary artery disease. In addition, there is a relationship between diesel exhaust and DEP exposure and vascular endpoints; these effects in diesel exhaust may be diminished with removal of DEP. Many extra-pulmonary health effects of diesel exhaust exposure, including systemic inflammation, pro-thrombotic changes, and cardiovascular disease, are considered consequent to pro-inflammatory events and inflammation in the lung. Future research will focus on the relative importance of diesel exhaust components, potential interactions between components and other pollutants, effects in sensitive individuals, and effects of longer or repeated exposures.