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In this work we demonstrate by transmission electron microscopy and piezoresponse force spectroscopy that the polarization direction in hydrothermally synthesized lead titanate (PbTiO3) nanorods can be changed from parallel to the nanorod axis to perpendicular to it by a simple heat treatment above the Curie temperature. The heat treatment also introduced 90° domains, caused a rearrangement of the surface and a reduction in the amounts of defects. The polarization of the heat-treated nanorods could be successively switched in the direction perpendicular to the nanorod axis. This control of the polarization in PbTiO3 nanorods opens up possibilities of tailoring the ferroelectric properties and is therefore highly relevant for the use of ferroelectric nanorods in devices. [ABSTRACT FROM AUTHOR]

Abstract: Chemical solution deposition (CSD) offers the opportunity to fabricate very thin electrolyte films at lower temperatures than traditional powder-based methods. CSD methods have not been used much in production of protonic ceramic fuel cells (PCFC) until now. In this contribution we describe thin film deposition of the two proton-conducting materials BaZr0.9Y0.1O3− δ (BZY) and La28− x W4+xO54+ δ (LWO) by spin coating. BZY films deposited on single-crystalline MgO grew epitaxially on the substrate. On a realistic PCFC cermet anode, 800nm thick BZY films could be fabricated with a columnar structure which is promising to circumvent the low conductivity at grain boundaries of BZY. LWO films with some porosity were deposited on platinized Si from an aqueous solution. [Copyright &y& Elsevier]

Physical restraint is used as a last resort emergency measure to calm and safeguard agitated and/or aggressive psychiatric patients. This can sometimes cause injuries, and rare fatalities have occurred. One mechanism of injury and death while in physical restraint is that of severe asphyxiation. We present the case of a hospitalized man in his mid-30s, suffering from schizophrenia. The patient was obese. He became aggressive and had to be manually restrained with a 'takedown.' After having been put in the prone position on the floor with a significant weight load on his body, he lost respiration and consciousness. Subsequently, he was given CPR. He regained consciousness and respiration, while the cyanosis receded in 1-2 min. Psychiatrists and pathologists should be aware that physically restraining a patient in the prone position with a significant weight load on the torso can, in rare cases, lead to asphyxiation. [ABSTRACT FROM AUTHOR]

Abstract: Nanotubes of ferroelectric lead titanate (PbTiO3) have been made by a template-assisted method. An equimolar Pb–Ti sol was dropped onto porous alumina membranes and penetrated into the channels of the template. Single-phase PbTiO3 perovskite nanotubes were obtained by annealing at 700°C for 6h. The nanotubes had diameters of 200–400nm with a wall thickness of approximately 20nm. Excess PbO or annealing in a Pb-containing atmosphere was not necessary in order to achieve single-phase PbTiO3 nanotubes. The influence of the heating procedure and the sol concentration is discussed. [Copyright &y& Elsevier]

CeO 2 surfaces play decisive roles in heterogeneous catalysis of important processes. Here, we investigate adsorption and dissociation of water and migration of protons on internal surfaces of nanoscopic porous CeO 2. Sorption and thermogravimetry confirm literature suggestions that the surface is hydrogenated to Ce3+ ions and protons H+. The following chemisorption is dissociative, yet weak, and physisorption sets in only at the very highest relative humidities, reflecting hydrophobic behaviour. We link sample conductivities to surface protonic conductances via a brick layer model and show that behaviours at high, intermediate, and low temperatures with, respectively, positive, close to zero, and negative apparent activation energies and p H 2 O 1/2, p H 2 O 1, and p H 2 O 3/2 dependences, can be attributed to different models of migration all within the chemisorbed layer, without contribution from physisorbed water. While CeO 2 may special in this respect due to the effect of the hydrogenated surface, we believe the extended models of transport in the chemisorbed layer may apply also to other oxides. Unsaturated chemisorption may play an important role for CeO 2 as catalyst in that the surface is left available for reactant molecules, still with availability of dissociated and mobile protons in the chemisorbed layer and electronic defects by Ce3+ in the surface. Different proton transport mechanisms in chemisorbed water explain surface conductance in porous CeO 2. [Display omitted] • Adsorbed water in porous nanoscopic CeO 2 parameterized by sorption and thermogravimetry. • Hydrogenation of surface by water affects chemisorption and causes hydrophobicity. • Consistent mechanisms of surface protonic migration in chemisorbed water on CeO 2. • Mechanisms supported by p H 2 O dependencies and preexponentials based on a brick layer model. [ABSTRACT FROM AUTHOR]

The atomistic and electronic structure and oxygen stoichiometry of nanocomposites between alumina and graphene oxide were investigated by density functional theory calculations. The nanocomposite was described as interfaces between α-Al 2 O 3 (0001) surfaces and graphene oxide; the latter was defined with oxygen bound as epoxy groups and a C:O atomic ratio of 4:1. The optimized composite structure with 1–3 layers of graphene oxide in between Al 2 O 3 contains bridging Al O C bonds at the interface. Reduction of the composite was investigated by removal of oxygen from the interface Al O C bonds, within the graphene oxide layers and in Al 2 O 3 . It was found that removal of oxygen within the graphene oxide layers is essentially independent of the Al 2 O 3 interface, i.e., the same as in pure graphene oxide. Oxygen was, however, more strongly bound in the interface Al O C bonds by 0.80 eV, and reduction of graphene oxide to graphene is accordingly preferred within the graphene oxide layers rather than at the oxide interface. [ABSTRACT FROM AUTHOR]

Abstract: La0.58Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathodes have been deposited on proton-conducting BaCe0.2Zr0.7Y0.1O3−δ (BCZY27) electrolyte and studied in symmetric cells to investigate the cathode microstructure and electrochemical performance. Three different types of cathodes have been prepared: two prepared from a solution, infiltrated into a screen-printed BZCY27 porous backbone (4 and 12 infiltrations), and one prepared by spray pyrolysis onto a polished electrolyte. In all three cases, LSCF is obtained after annealing at 700°C for 2h. Analysis of the electrochemical impedance spectra between 450°C and 600°C in air, with varying p(H2O), reveals that the charge transfer contribution is the lowest for the backbone-infiltrated cathode while the oxygen dissociation/adsorption contribution is the lowest for the spray-pyrolyzed cathode. The area specific resistances increase with the water vapor pressure. The area specific resistances obtained are 0.61Ωcm2 and 0.89Ωcm2 at 600°C for the spray-pyrolyzed LSCF cell in dry and humidified air, respectively; the corresponding resistances are 0.63Ωcm2 and 0.98Ωcm2 for the 12 times infiltrated LSCF cell. These resistances are the lowest reported for LSCF cathodes on Ba(Ce,Zr)O3-based electrolytes and show the promise of low-temperature fabrication methods for these systems. [Copyright &y& Elsevier]

Abstract: Accelerated climate aging experiments and cup measurements have been performed to investigate the effect of adding TiO2 nanoparticles and nanoclay to acrylic stain coatings against the influence of weathering. The coated specimens resistance toward solar radiation and water spray was evaluated by the discoloration rate from visual assessment and color analysis and by the chemical changes observed by Fourier transform infrared spectroscopy. Furthermore water vapor resistance was examined by the cup measurements. The nanomaterial containing coatings provided in general better protection against the artificial aging than the unmodified coating, showing the nanomaterials may have a natural place in coatings for protection of wood. [Copyright &y& Elsevier]