Earlier work has confirmed that (i) observers can judge divergent receding lines, placed directly in front of them, to be parallel, and (ii) converging lines which are displaced laterally, so that they are viewed obliquely, can also be judged to be parallel. The former observation is in accord with traditional views of perspective while the latter, which is in accord with the depictions of obje...

The title compound has been isolated as single crystals from the synthesis of propylene carbonate from racemic 1,2-propanediol and carbon dioxide using n-Bu2SnO as a catalyst precursor. The X-ray crystallographic structure analysis revealed the self-assembly of di-n-butyltin(IV) 1,2-propanediolate units, linked together through long-distance Sn–O interactions leading to a one-dimensional polyme...

The spin Hamiltonian parameters for the two Cu centers A1 and A2 in the calcined catalysts CuO–ZnO are theoretically investigated using the high order perturbation formulas of these parameters for a 3d ion in tetragonally elongated octahedra. In the above formulas, the tetragonal field parameters Ds and Dt are determined from the superposition model, by considering the relative axial elongation...

It is well known that glass undergoes elastic and inelastic deformation under a sharp diamond indenter. Although brittle or less brittle behavior of glass must be connected with such mechanical responses of glass under the indenter, there has been limited research on in situ deformation behavior of glass during the loading and unloading indentation cycle. This is because most indentation tests ...

Mackinawite,tetragonal FeS, has been synthesised by reacting iron with Na2S solutions. A Rietveld structure refinement of X-ray powder diffractipn data, recorded using X-rays monochromated from synchrotron radiationwith a wavelength of 0.6023 A, has been performed. The structure has been refined in the tetragonal sJ'.!lcegroup, P4/nmm, and has the following cell parameters: a = 3.6735(4), c = 5...

Recrystallization and structural recovery in α-decay damage in zircon samples have been studied using Raman spectroscopy. Fifteen zircon samples with different degrees of radiation damage have been thermally annealed between 600 K and 1800 K for up to 28 days and 8 hours. The experimental results from this study reveal that recrystallization in the damaged zircon samples is a multi-stage proces...

The Schiff bases (H3L), derived from 2-acetylpyrrole and carbonohydrazide, and its reactions with some transition metal ions (Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)) afforded complexes of formulae [M(H5LA)2(H2O)x]∙2(NO3)∙(CH3CN)z∙(H2O)y-x (M= Co, Ni, Cu or Zn ; 0 ≤ x < y ≤ 3, z = 0 or 1) and {Cd(H4LA)(NO3)}n. These compounds have been characterized by means of elemental analysis, UV–Vis spec...

We present an optimal single-winner preferential voting system, called the “GT method” because of its interesting use of symmetric two-person zero-sum game theory to determine the winner. Game theory is not used to describe voting as a multi-player game between voters, but rather to define when one voting system is better than another one. The cast ballots determine the payoff matrix, and optim...

Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have proved to be important structural ceramics. High strength and fracture toughness make them attractive candidates for a number of demanding applications. It was established that these advantageous properties are strongly influenced by the ceramic microstructure [1]. The relationships between microstructure and mechanical properties ...

Zirconia is a widely used oxide ceramic in various high performance applications due to its attractive mechanical, electrical and thermal properties. In particular, the material 3 mol% yttria stabilized tetragonal zirconia (3YTZ) has been shown to undergo superplastic deformation [1]. One crucial step in the understanding of processes like superplasticity involves the knowledge of appropriate c...