The results of XPS measurements of commercially pure titanium (cp-Ti) before and after chemical treatment are presented. We have measured XPS spectra of core levels (Ti 2p, O 1s, C 1s, F 1s) and valence bands of coarse-grained cp-Ti before and after standard acid treatment accepted in dentistry (in 1% HF and 40% HF for 1 min). It is found, that acid treatment of cp-Ti reduces the content of hyd...

Polarization and electrochemical impedance spectroscopy of p-type 6H-SiC electrodes in an aqueous hydrofluoric acid solution is performed during the formation of porous SiC. The polarization of p-type SiC permits the identification of the flatband voltage, a Tafel-like region, and a limiting current which is attributed to the onset of the electropolishing regime. For some of the potential range...

Heavy metals in sediments have received increasing attention in recent years, partly because of the growing scientific and public awareness of environmental issues, and partly because of the improvement in the analytical techniques for accurately measuring their concentrations. Trace metal determinations in soils and sediments commonly involve some type of mineral acid extraction (wet oxidation...

OBJECTIVE The aim of this study was to evaluate the bond strength between metal brackets and non-glazed ceramic with three different surface treatment methods. MATERIALS AND METHODS Forty-two non-glazed ceramic disks were assigned into three groups. Group I and II specimens were etched with 9.5% hydrofluoric acid. Subsequently in group I, silane and adhesive were applied and in group II, bond...

OBJECTIVE To compare different surface treatments of lithium disilicate-based ceramic on bond strengths to composite. METHODS Lithium disilicate-based ceramic microbars (1 mm × 1 mm × 6 mm) were produced and abraded using diamond (D) or CoJet sandblasting (C), etched using phosphoric acid (P) or hydrofluoric acid (H) and silanised (S). A total of 12 surface treatments were adopted: D, DP, DH,...

In this paper, a tapered tip optical fiber probe sensor for localized refractive index (RI) measurements is presented. This sensor’s interaction with analytes is confined to a few micro-meters which makes it a promising candidate for in-vivo or even intra-cellular RI monitoring. This tapered tip was simply fabricated by etching optical fiber with hydrofluoric acid to a conic shape with a sub-m...

The possibility of a wide range adjustment the hydrophilic-hydrophobic properties silicon wafers is demonstrated by means treatment with hydrofluoric acid, Caro's and various concentrations hydrogen peroxide solutions. By measuring contact angles wetting calculating total, polar, dispersive components surface energy, it has been found that most significant hydrophilization as well maximum incre...

This paper suggests an improved method for the sample preparation to quantify vanadium, chromium, nickel and copper in tool steel high-speed by using flame atomic absorption spectrometry. The suggested prepared two specimen solutions containing different internal standard elements: one included quantifications of vanadium or cobalt quantification chromium another phosphoric acid nickel, after w...