Article history: Received 2 February 2016 Received in revised form 24 May 2016 Accepted 5 June 2016 Available online 11 June 2016 Classical molecular dynamics (MD) simulations were used to study the structural changes in the surfaces of biocompatible phosphate glasseswith compositions (P2O5)0.45(CaO)x(Na2O)0.55−x (x=30, 35, 40) to evaluate their effect on the solubility of the material. Direct ...

The X-band EPR spectra of the UV -, X -, and γ irradiated glasses of the SiO2-Na2O-CaO-P2O5 (Bioglass) and CaO-Ga2O3-GeO2 systems with different chemical compositions have been investigated at temperatures 77 and 300 K. It was shown that the efficiency of generation of the electron and hole centers in glasses of both systems strongly depends on their basic composition and is almost independent ...

This study aims to investigate the activating effect of Na2CO3 and NaOH on the workability and mechanic strength of slag-based alkali activated materials with different alkali contents and water to binder ratios. The heat release during the reaction process of slag activated with sodium carbonate and sodium hydroxide were monitored respectively to analyze the hydration process. Meanwhile, the w...

Shrinkage behavior of a geopolymer cement paste prepared from pumice-type natural pozzolan was studiedby changing parameters of chemical composition including SiO2/Na2O molar ratio of activator and total molar ratiosof Na2O/Al2O3, and H2O/Al2O3. For investigating the effect of curing conditions on shrinkage, hydrothermal curingwas also applied. The obtained results clearly revealed the governin...

[1] Among volcanic hot spots globally, Hawaii has the highest magma flux, yet there is significant controversy surrounding the composition of the mantle sourcing Hawaiian lavas. In order to place constraints on the source lithologies of Hawaiian lavas, we explore relationships between major elements and radiogenic isotopes in tholeiitic, shield-building lavas. Olivine-fractionation corrected la...

The mechanism of lime dissolution in steelmaking slag and the factors that influence rate are highly significant improving efficiency process; however, they yet to be fully understood. Here, effects Al2O3/TiO2/Na2O additives on composition molten were investigated using a rotating cylinder technique. results indicate promotion coefficients at 1400 °C decrease order Na2O > TiO2 Al2O3. Further...

The effect of TiO2 layer applied to the conventional Fe2O3/FTO photoanode to improve the photoelectrochemical performance was assessed from the viewpoint of the microstructure and energy band structure. Regardless of the location of the TiO2 layer in the photoanodes, that is, Fe2O3/TiO2/FTO or TiO2/Fe2O3/FTO, high performance was obtained when α-Fe2O3 and H-TiNT/anatase-TiO2 phases existed in t...

The Brillouin elastic free energy change between thermally annealed and quenched (Na2O)x(SiO2)1−x glasses is found to increase linearly for x > 0.23 (floppy phase), and to nearly vanish at x < 0.18 (stressed-rigid phase). The observed (x) variation closely parallels the mean-field floppy mode fraction f (x) in random networks, and fixes the two (floppy, stressed-rigid) elastic phases. In calori...

Sandstones sampled from Patti Formation, Southern Bida Basin, were studied geochemically using Inductively Coupled Plasma Atomic Emission Spectrophotometer (ICP-AES) and an Mass Spectrometry (ICP-MS) technique to evaluate their weathering tectonic setting as well deduce the paleo-climatic conditions that existed during deposition. Geochemically, SiO2 range 73.9% 86.2%, Al2O3 (6.7%~17.1%), Fe2O3...