First principles calculations are employed to provide a fundamental understanding of the relationship between the reactivity of synthetic calcium silicate phases and their electronic structure. Our aim is to shed light on the wide range of hydration kinetics observed in different phases of calcium silicate. For example, while the dicalcium silicate (Ca2SiO4) phase slowly reacts with water, the ...

A layered silicate, KHSi2O5, was synthesized via a hydrothermal method using an amorphous silicon dioxide (SiO2) block, which is industrial waste. This silicate used as host compound for ion-exchange reactions with Ag+ and Cu2+ ions, the antibacterial properties of ion-exchanged compounds were investigated. The crystal structures retained during reaction; however, in case Cu2+, small amount Cu(...

The aim of this study was to evaluate the influence of a calcium silicate-based sealer (iRoot SP), with or without a core material, on bond strength to radicular dentin, in comparison with various contemporary root filling systems. Root canals of freshly extracted single-rooted teeth (n = 60) were instrumented using rotary instruments. The roots were randomly assigned to one of the following ex...

the relationship between female oviposition preference and offspring performance is a key area of study on the evolution of host specificity. this study investigates host prefer-ence of the polyphagous hover fly syrphus ribesii (diptera: syrphidae) and compares it with some components of its offspring`s performance. females and offspring were tested on six naturally used aphid hosts (blackberry...

Polycrystalline Er-Sc silicates (Er x Sc2-x Si2O7 and Er x Sc2-x SiO5) were fabricated using multilayer nanostructured films of Er2O3/SiO2/Sc2O3 deposited on SiO2/Si substrates by RF sputtering and thermal annealing at high temperature. The films were characterized by synchrotron radiation grazing incidence X-ray diffraction, cross-sectional transmission electron microscopy, energy-dispersive X...

The structure of haiweeite, Ca[(UO2)2Si5O12(OH)2](H2O)3, Z = 4, orthorhombic, a 7.125(1), b 17.937(2), c 18.342(2) Å, V 2344.3(7) Å3, space group Cmcm, has been solved by direct methods and refined by full-matrix least-squares techniques to an agreement index (R1) of 4.2% for 1181 unique observed reflections (|Fo| ≤ 4 F) collected using MoK X-radiation and a CCDbased area detector. The structur...

The study of the O and C isotope composition calcite from nepheline syenites, ijolites carbonatites Chik intrusion intrusions Erzin–Tarbagatay group Sangilen (Eastern Siberia, Russia) showed derivation alkaline melts enriched with a carbonate component host marbleized sedimentary rocks. calculations that about 40% initial mass carbonates involved in interaction silicate have remained after deca...

To test whether exoplanets are similar to Earth, knowledge of their host star composition is essential. Stellar elemental abundances and planetary orbital data show that the ~5,000 known minerals, exoplanetary silicate mantles contain mostly olivine, orthopyroxene, clinopyroxene, ± quartz magnesiowüstite at extremes, while wholly exotic mineralogies unlikely. Understanding geology requires a be...

Porous silica materials made by low-temperature sol-gel process are promising host matrixes for encapsulation of biomolecules. To date, researchers have focused on sol-gel routes using alkoxides such as tetramethyl orthosilicate (TMOS) and tetraethyl orthosilicate (TEOS) for encapsulation of biomolecules. These routes lead to formation of alcohol as a byproduct that can have a detrimental effec...

2.0 μm emission properties of Er3+/Ho3+ codoped silicate glasses were investigated pumped by 980 nm LD. Absorption spectra were determined. Intense mid-infrared emissions near 2 μm are observed. The spectral components of the 2 μm fluorescence band were analyzed and an equivalent model of four-level system was proposed to describe broadband 2 μm emission. Low OH- absorption coefficient (0.23 cm...