Properties of glasses are typically controlled by judicious selection of the glass-forming and glass-modifying constituents. Through an experimental and computational study of the crystalline, molten, and amorphous [Ca12Al14O32](2+) ⋅ (e(-))2, we demonstrate that electron anions in this system behave as glass modifiers that strongly affect solidification dynamics, the glass transition temperatu...

The process of biodeterioration of optical glass was studied after being induced by an auxiliary material (lubricant 4CKP) used in the production of optical instruments. It was determined that the lubricant can initiate growth of conidia of Aspergillus niger fungus. Acid spawn metabolites cause deterioration of the glass surface. Measurements of laser light beam transmittance through the glass ...

We have calculated the T0 curves for several Al-rare-earth binary alloys to assess the importance of the transport-based resistance to crystallization in the overall glass formation process and the general effectiveness of thermodynamic prediction of glass-forming ability. Our results show that the experimentally observed glass-forming compositions for Al-(Ce, Gd, Ho, Nd, Y, Dy) alloys strongly...

S. Krum, F. Pešlová, Czech Technical University in Prague, Faculty of Mechanical Engineering Prague, Czech Republic, J. Kliber VŠB TU Ostrava, Czech Republic Corrosion resistant steels are used for the prod uction of parts exposed to corrosive environment and also to thermo-mechanical loads. Steel molds in the glass manufacture industry with their functional surfaces simultaneously exposed to t...

The present study aimed to compare the fluoride (F-) release pattern of a nanofilled resin-modified glass ionomer cement (GIC) (Ketac N100 - KN) with available GICs used in dental practice (resin-modified GIC - Vitremer - V; conventional GIC - Ketac Molar - KM) and a nanofilled resin composite (Filtek Supreme - RC). Discs of each material (n=6) were placed into 4 mL of deionized water in sealed...

The aim of this study was to assess the microhardness of 5 glass ionomer cements (GIC) - Vidrion R (V, SS White), Fuji IX (F, GC Corp.), Magic Glass ART (MG, Vigodent), Maxxion R (MR, FGM) and ChemFlex (CF, Dentsply) - in the presence or absence of a surface protection treatment, and after different storage periods. For each GIC, 36 test specimens were made, divided into 3 groups according to t...

Although glass is usually considered as a very stable archaeological material, it can undergo severe degradation. Soda-lime glass, the most common glass throughout ancient times, is particularly sensitive to this problem. The glass surface absorbs moisture from its environment and the contact with CO2 causes Na2O and NaOH to convert to Na2CO3, which is extremely hygroscopic. The subsequent unst...

PURPOSE The objective of this study was to assess the microleakage of the new conventional glass ionomer, Fuji IXgp in comparison to another conventional glass ionomer (Fuji II), a resin modified glass ionomer (Vitremer) and a composite resin (TPH) in primary and permanent teeth. METHODS Twenty-five extracted human premolars and 13 primary molars were used. Preparations were made on the cente...

Crack propagation across interlayers separating adjoining brittle plates in flexure was studied using a model glass/epoxy/glass system. A transverse starter crack in the center glass plate was made to propagate to the nearest epoxy interface, where it arrested. System failure occurred at some higher load by crack reinitiation from pre-existing flaws in the adjoining glass surface, not by contin...

The critical aims of glass envelope design and development must be to enable measures upon glass buildings to prevent uncontrolled heating of the building surfaces, increase emissivity and the impacts of this heat conduction into the building interior spaces. Current glass envelopes depend upon hybrid facades, double skin glass facades; solar shading; passive solar energy systems (transparent i...