Winemaking of musts acidified with up to 3g/L of gypsum (CaSO4 2H2O) and tartaric acid, both individually and in combination, as well as a chemical modeling have been carried out to study the behaviour of these compounds as acidifiers. Prior to fermentation gypsum and tartaric acid reduce the pH by 0.12 and 0.17 pH units/g/L, respectively, but while gypsum does not increase the total acidity an...

In the present study, traditional and hybrid composites were prepared by Hand lay-up molding and investigated. The composites constituents were unsaturated polyester resin as the matrix, 3% and 6% volume fractions of carbon fibers as reinforcement and 3% of Al2O3, Al, Cement and local Gypsum (calcium sulfate anhydrate CaSO4) as filler particles. The investigated physical properties were density...

The internal surface area of hexagonal (soluble) primary anhydrite CaSO4 produced by dehydration of gypsum decreases by about 70 % when the anhydrite is successively subjected to rehydration and dehydration at room temperature in humid air and in vacuum respectively. In the rehydration step, the hemihydrate is formed; its dehydration yields secondary anhydrite. Additional hydration-dehydration ...

A protein concentrate (PC) was obtained from Grouper fish skin and it was used to prepare films with different amounts of sorbitol and glycerol as plasticizers. The best performing films regarding resistance were then modified with various concentrations of CaCl2, CaSO4 (calcium salts), and glucono-δ-lactone (GDL) with the purpose of improving their mechanical and barrier properties. These film...

In three dairy grasslands on peat, minerals were added to manipulate the soil Ca:Mg ratio with or without effect pH. The responses of properties and grass N yield measured. CaCO3 application led higher pHKCl compared untreated control, decreased Ntotal Ctotal, increased P availability. Grass in first year by only 6% reduction Ntotal, but not second year. A pH SOM decomposition, especially soils...

The leaching characteristics of fly ash from a cobalt smelter were studied as a function of pH and time using the pH-static leaching test (CEN/TS 14997, pH range 5-12) coupled with mineralogical investigation and speciation-solubility modelling. Two sets of experiments with different equilibration time (48 h and 168 h) were performed. The leaching of metals showed typical U-shaped curves with t...

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4 x 2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid ...

Anhydrite (CaSO4) phenocrysts from Mount Pinatubo pumices show evidence of having responded dynamically to changing conditions prior to the June 15, 1991 climactic eruption. Micrometer-sized and smaller pyramidal surface growth features and lesser numbers of etch pits on anhydrite surfaces are documented by scanning electron microscopy. Chemical analyses indicate that the pyramids are a CaSO4 p...