We report a first-principles simulation study of phase transitions in KNO3, using our recently developed method for treating ionic molecular solids. With the interionic potentials calculated from ab initio electron charge densities of the ions, our structural static relaxation gave close fits to both the normal room-temperature (α-phase) and the ferroelectric (γ-phase) structures. Our supercell...

We carried out reversed piston-cylinder experiments on the equilibrium paragonite = jadeite + kyanite + H2O at 700 C, 1.5–2.5 GPa, in the presence of H2O-NaCl fluids. Synthetic paragonite and jadeite and natural kyanite were used as starting materials. The experiments were performed on four different nominal starting compositions: X(H2O)=1.0, 0.90, 0.75 and 0.62. Reaction direction and extent w...

Ni6(N2H4)6(SO4)4(OH)2(H2O)8](SO4)(H2O)10 complex was prepared according to literature report. The reaction between aforementioned complex via sodium alkoxides as a reactants, were carried out in the solid state. The [Ni6(N2H4)6(SO4)4(OH)2(H2O)8](SO4)(H2O)10 undergoes an intramolecular two electrons oxidation-reduction reaction at room temperature and metallic nickel nanoparticles (Ni1-Ni5) was ...

A new bis-N,N'-(5-methylimidazol-4-ylmethyl) derivative of a 14-membered tetraazamacrocycle, L1, has been synthesized. The protonation constants of this compound and the stability constants of its complexes with divalent first-row transition metal ions and Fe3+ were determined at 298.2 K in aqueous 0.10 mol dm(-3) KNO3. Compound L1 exhibits high overall basicity, which is mainly conferred by th...

    Background: The use of positive end-expiratory pressure (PEEP) can have an important role as one of the ways to prevent and treat atelectasis, but it seems that there is still no consensus about its beneficial level. The aim of this study was to determine the effect of different levels of PEEP on the incidence of atelectasis after heart surgery.    Methods: This is...