PURPOSE To analyze the surface composition of 34 different commercially available titanium dental implants. MATERIALS AND METHODS Surface composition was evaluated by x-ray photoelectron spectroscopy (XPS). Samples were divided into 4 groups, depending on their surface topography (machined, sandblasted, acid etched, or plasma sprayed). RESULTS Statistical analysis of the data showed a clear...

The ablation and oxidation of ZrB₂-based ultra high temperature ceramic (UHTC) composites containing 10%, 15% and 30% v/v SiC were tested under different heat fluxes in a high frequency plasma wind tunnel. Performance was significantly affected by the surface temperature, which was strongly dependent on the composition. Composites containing 10% SiC showed the highest surface temperature (>2300...

Statistical copolymer films that consist of two types of monomers, a sticky and a glassy monomer, are investigated. These model systems of pressure-sensitive adhesive films are probed with X-ray reflectivity and mechanical tack measurements. For the first time, composition profiles along the surface normal in the near-surface region are monitored. The influence of the type of monomers being cop...

Perennial macroalgae within the genus Fucus are known to exude metabolites through their outer thallus surface. Some of these metabolites have pro- and/or antifouling properties. Seasonal fluctuations of natural fouling pressure and chemical fouling control strength against micro- and macrofoulers have previously been observed in Fucus, suggesting that control strength varies with threat. To da...

This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10); RL = conventional brackets, Roth Light Morelli® (n = 10); N...

Nanoporous glass-ceramics were prepared with composition 45CaO-25TiO2-35P2O5 (mol%). Two molar percent of Na2O was added as a flux to the composition. With the aforementioned composition, glass melted and crystallized into glass-ceramics containing β-Ca3(PO4)2 and CaTi4(PO4)6 as the main phases. The differential thermal analysis (DTA) was conducted to determine the suitable temperatures f...

A Monte Carlo simulation of a two-dimensional lattice gas with free boundaries is used to study the effects of surface and size on the chemical potential-composition curves of intercalation compounds. In particular we are interested in electrochemically active nanosize lithium intercalation compounds. Both surface and size effects were found to modify the chemical potential versus composition b...

In this work, we develop a correlative model based on the surface tension data in order to calculate thermodynamic parameters, such as interaction energy between components (Uij), activity coefficients and etc. In the new approach, by using Li et al. (LWW) model, a three-parameter surface tension equation is derived for liquid mixtures. The surface tension data of 54 aqueous and 73 non-aqueous ...

In this study chemical method of dissolution-Precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (RSA), the waste material of rice cultivation. The morphology, particle size, structure and area of specific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and BET...

Water stable isotopes in Greenland ice core data provide key paleoclimatic information, and have been compared with precipitation isotopic composition simulated by isotopically enabled atmospheric models. However, postdepositional processes linked with snow metamorphism remain poorly documented. For this purpose, monitoring of the isotopic composition (δ18O, δD) of near-surface water vapor, pre...