The purpose of this research was to study the marginal adaptation of eight calcium silicate-based materials when used to seal large furcal perforations, compared with one resin-modified glass-ionomer cement by scanning electron microscopy (SEM). Сonclusion:All tested calcium silicate-based materials showed good marginal adaptation and are suitable for large furcal perforation repair.

The isotopic analysis of boron from material that carries only trace amounts of boron requires low boron blank levels. Large efforts are taken to keep blank levels low by purifying reagents. We performed exposure experiments and determined procedure blanks before and after the air-handling system was modified from silicate glass filters to polyethylene/polystyrole and active carbon filters. Our...

this study is focused on synthesis of nano-colloidal silica via alkaline water glass solution. sodium ions of water glass were removed by cation exchanging in a resin column to obtain the silicic acid which was titrated to the solution of sodium silicate. concentration of the colloidal silica and ph value of the solutions were controlled using different concentrations of alkaline sodium silicat...

To create a more cost effective glass while preserving its safety, the composition of soda-lime silicate glass was modified. The amount of Silicon dioxide in the composition was decreased in order to lower the melting point of the glass, thus making the new glass more cost-effective due to lower energy consumption. Calcium oxide and sodium oxide concentrations were increased to raise chemical d...

Silicate glasses are durable materials, but are they sufficiently durable to confine highly radioactive wastes for hundreds of thousands years? Addressing this question requires a thorough understanding of the mechanisms underpinning aqueous corrosion of these materials. Here we show that in silica-saturated solution, a model glass of nuclear interest corrodes but at a rate that dramatically dr...

Glass-ceramics are polycrystalline materials of fine microstructure that are produced by the controlled crystallisation (devitrification) of a glass. Numerous silicate based wastes, such as coal combustion ash, slag from steel production, fly ash and filter dusts from waste incinerators, mud from metal hydrometallurgy, different types of sludge as well as glass cullet or mixtures of them have b...

Introduction: Pt nuggets found in the silicate glass of solubility experiments at low fO2 may be the quench products of Pt in solution in silicate liquid, not mechanical contaminants. Pt solubilities measured in the range of geologically interesting fO2 would then be several orders of magnitude higher than conventionally assumed. Such a finding may remove the perception of "excess" Pt in Earth'...

The influence of a changing glass topology on local mechanical properties was studied in a multitechnique nanomechanical approach. The glass response against sharp contacts can result in structural densification, plastic flow, or crack initiation. By using instrumented indentation testing, the mechanical response was studied in different strain rate regimes for a sodium borosilicate glass (NBS)...

Spontaneous and photo-induced crystallization have been investigated in fluorinated silicate glass by means of X-ray diffraction and optical interferometry. This glass is a photo-sensitive material for high-efficiency phase volume hologram recording. Variations of a refractive index in this glass are controlled by UV irradiation followed by a thermal development which is photo-thermo-refractive...

-The bioactive glass 45S5 (Hench glass), having composition 45 SiO2 24.5 Na2O 24.5 CaO -6 P2O5 (wt %) were prepared with substituted Li2O, K2O, ZnO, MgO, and B2O3 by conventional melting process in an electric globar furnace at 1400±10 OC. The Controlled crystallization were carried out to convert the bioglasses to their corresponding bioglass ceramics. Nucleation and crystallization regimes we...