Barium enemas are one of the most commonly requested radiological examinations. Here in Bristol the enemas are carried out in double contrast, which is becoming widely accepted as the standard examination of the colon (Thoeni and Margulis 1978). However there are several problems which have to be overcome if an optimal double contrast examination is to be obtained. The colon must be free of its...

Geoengineering is the deliberate large-scale manipulation of environmental processes that affects the Earth's climate, in an attempt to counteract the effects of climate change. Injecting sulfate aerosol precursors and designed nanoparticles into the stratosphere to (i.e., solar radiation management [SRM]), has been suggested as one approach to geoengineering. Although much is being done to unr...

We report the solution-based synthesis of single-crystalline nanorods composed of barium titanate (BaTiO3) and strontium titanate (SrTiO3), which yields well-isolated nanorods with diameters ranging from 5 to 60 nm and lengths reaching up to >10 mum. Electron microscopy and diffraction measurements show that these nanorods are composed of single-crystalline cubic perovskite BaTiO3 and SrTiO3 wi...

This study reports the synthesis of morphology-controlled BaTiO(3) nanostructures such as spherical, cube-shaped and rod-shaped BaTiO(3) using a molten-salt synthesis method. This method synthesized products from a reaction of BaO/BaCO(3) and TiO(2) with a eutectic mixture of NaCl-KCl flux at 700 degrees C for 1 h. The experiment used powder X-ray diffraction, field emission scanning electron m...

The effect of reduction and re-oxidation firing on the PTCR properties of Sm-doped barium titanate ceramics was investigated for the application in multilayered PTC thermistors. The lattice parameters a, and c decreases monotonically with increasing oxygen concentration in the re-oxidation atmosphere, which seems to be related with an electrostatic Coulomb interaction between an oxygen vacancy ...

Effects of montmorillonite and barium titanate nanofillers V. Tomer, G. Polizos, E. Manias, and C. A. Randall Department of Materials Science and Engineering, Materials Research Laboratory, Center of Dielectric Studies (CDS), The Pennsylvania State University, University Park, Pennsylvania 16802, USA Department of Materials Science and Engineering, Polymer Nanostructures Laboratory, Center for ...

Substantial softening in the bulk modulus (a factor of five) and a negative Poisson ratio (-0.25) have been observed via broadband viscoelastic spectroscopy in the vicinity of the Curie point of a barium titanate ceramic. These effects were observed under electrical short-circuit conditions at low deformation frequencies. Softening was less in an electric open circuit or at higher frequencies. ...

Barium titanate single crystals had been placed in 0.01M NaOH solution to deposit hydrogen on their electrodes through the electrolysis of water. Two kinds of time-dependent changes in dielectric properties of the single crystals were observed: One occurred in the course of hydrogen deposition and the other lasted for a long period of time after the deposition. The diffusion of hydrogen and in ...

The thioborate phase Ba7(BS3)4S was synthesized from solid state reaction and its crystal structure determined by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group C2/c (No. 15) with a = 10.1750(15) A, b = 23.970(4) A, c = 10.1692(15) A, beta = 90.095(2) degrees, and Z = 4. The structure consists of isolated trigonal planar (BS3)3- anions, and isolated S2-...

We prepared magnesia, tantalum oxide, and barium titanate based tunnel junction structures and investigated their memristive properties. The low amplitudes of the resistance change in these types of junctions are the major obstacle for their use. Here, we increased the amplitude of the resistance change from 10% up to 100%. Utilizing the memristive properties, we looked into the use of the junc...