Sulphate removal from mine water with chemical, biological and membrane technologies.

Chemical, physical and biological technologies for removal of sulphate from mine tailings pond water (8 g SO/L) were investigated. Sulphate concentrations of approximately 1,400, 700, 350 and 20 mg/L were obtained using gypsum precipitation, and ettringite precipitation, biological sulphate reduction or reverse osmosis (RO) after gypsum pre-treatment, respectively. Gypsum precipitation can be widely utilized as a pre-treatment method, as was shown in this study.

Release of fluoride from glass fiber-reinforced composite with multiphase polymer matrix.

This study investigated the suitability of a fluoride containing monomer resin system for use as a copolymer of dental fiber-reinforced composite (FRC) materials. The purpose of the study was to measure the release of fluoride from the test materials. The monomer resin system was either light-polymerized, or light-polymerized and post-cured with heat at 130 degrees C.

Water sorption, solubility and effect of post-curing of glass fibre reinforced polymers.

Different polymer matrices are used for dental glass fibre composites. The aims of this study were to determine water sorption and solubility of glass fibre composites with different polymer matrices. In addition, the effect of post-curing of matrix polymers with heat on the water sorption and solubility values was investigated.

Water sorption and solubility of glass fiber-reinforced denture polymethyl methacrylate resin.

Polymethyl methacrylate (PMMA) absorbs water slowly over a period of time, primarily because of the polar properties of the resin molecules. The aim of this study was to determine the water sorption and solubility of heat-cured and chemical-cured glass fiber (GF) PMMA composite used in dentures. The test specimens (n = 5) were fabricated from experimental, unidirectional, continuous GF reinforcement; the GF concentration of the test specimens was approximately 11% by weight.