High-resolution transmission electron microscopy observations and magnetic ac susceptibility measurements have been carried out to study the changes in the magnetic properties of La1−xSrxCoO3 samples (x 0.3) processed at different annealing temperatures, ranging from 1273 to 1573 K. Although neutron diffraction excludes the coexistence of distinct phases with different chemical composition, roo...

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computer code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind ...

An influence of high temperature annealing process (before crystallization) on the atomic structure of two different as-prepared ribbon Cu–Zr–Ti metallic glasses (Cu60Zr20Ti20 and Cu55Zr16Ti29, at. %) was experimentally studied by means of differential scanning calorimetry and in situ hard X-ray diffraction. Results of our experiments prove different atomic structure and behaviour of the glasse...

The paper deals with the curing behaviour of diglycidyl ether of bisphenol-A (DGEBA) using three novel multifunctional aromatic amines having phosphine oxide and amide-acid linkages. The amines were prepared by reacting tris(3-aminophenyl)phosphine oxide (TAP) with 1,2,4,5-benzenetetracarboxylic acid anhydride (P)/4,4-(hexafluoroisopropylidene)diphthalic acid anhydride (F)/3,3,4,4-benzophenonet...

The microcalorimetric studies on the polymerization of acrylonitrile with and without the thermal influence of polyacrylonitrile decomposition provide vital information on its thermal sensitivity and intrinsic safety. The present studies indicate that the exothermicity of polymerization and decomposition of polyacrylonitrile are kept under check by the self-regulatory role of the aqueous medium...

In the crystal structure of the title mol-ecular salt, C5H6N(+)·C6H2N3O8 (-) (systematic name: pyridinium 3-hy-droxy-2,4,6-tri-nitro-phenolate), the pyridin-ium cation and the 3-hy-droxy-2,4,6-tri-nitro-phenolate anion are linked through bifurcated N-H⋯(O,O) hydrogen bonds, forming an R 1 (2)(6) ring motif. The nitro group para with respect to phenolate ion forms an intra-molecular hydrogen bon...

Ceramic thermal barrier coatings are commonly used in gas turbine hot components (e.g., combustor liners/buckets and guide vane platforms). In components that are only partially coated or have cooling-air outlets, coating-end stress singularities may lead to the spallation of the coating. Depending on the geometry of the transition from coated to uncoated material, the severity of the stress si...

A new class of functionalised dicationic ionic liquids, containing a central cationic unit capped by a basic functionality (imidazole), has been synthesised. These salts have been characterised in isotropic solution using proton and 2D-NMR spectroscopy, and their thermal stability has been studied by DSC and TGA. All these novel salts contain the 1-(1-imidazolylmethyl)-3,5-di{1-(3'-octylimidazo...

As was shown in the past by XRD, TEM and RBS measurements, heavy ion irradiation of nanocrystalline ZrO2 samples using 4 MeV Kr + ions causes the formation of a tetragonal zirconia phase that is stable at room temperature [1]. This phase is employed in solid oxide fuel cells and oxygen sensors, but usually has to be stabilized by addition of a second phase, e.g. Y2O3, which is not necessary whe...