Fibrous dusts (chrysotile, glass fibers, nemalite, palygorscite, and gypsum) and granular dusts (actinolite, biotite, hematite, pectolite, sanidine, and talcum) were injected intraperitoneally into rats. The fibrous dusts (other than gypsum) resulted in a high incidence of mesothelioma (30 - 67%). Gypsum produced only 5% and granular dusts none at all. It is suggested that the fibrous shape lea...

Lime, gypsum and various gypsum-like by-products have long been applied to soil surfaces as ameliorants of soil acidity and aluminium and manganese toxicity. We examined changes in chemical and mineralogical properties at two different depths in two acid soils one year after the application of gypsum, phosphogypsumþ dolomitic residue, red gypsumþ dolomitic residue, sugar foam, and sugar foamþmi...

Revegetation efforts generally have failed to establish substantial cover on bentonite mine spoil, but certain amendments have shown promise for improving spoil as a plant growth medium. These growthpromoting improvements were at least partially the result of effects of these amendments on spoil chemistry. We undertook this study to determine the effects of selected amendments (gypsum, fertiliz...

Water vapour transport properties of gypsum block are studied in dependence on relative humidity using inverse analysis based on genetic algorithm. The computational inverse analysis is performed for the relative humidity profiles measured along the longitudinal axis of a rod sample. Within the performed transient experiment, the studied sample is exposed to two environments with different rela...

[1] Soil sulfates are present in arid and hyperarid environments on Earth and have been found to be abundant in soils on Mars. Examination of soil gypsum from the Atacama Desert, Chile, the Mojave Desert, United States, and Al-Jafr Basin, Jordan, revealed endolithic cyanobacteria communities just below the surface of soil gypsum samples. Optical and scanning electron microscope observations of ...

Cement is produced by co-grinding clinker, gypsum and other components defined in the Cement Standards like limestone, pozzolans, fly ash and slag. The grinding is usually performed in horizontal ball mills. Gypsum is typically the basic source of sulphates (SO3) in the cement. The effect of gypsum on the cement quality is critical and twofold. It affects two of the main properties of this prod...

The utility of a laboratory diagnostic approach was investigated for a systematic evaluation of the impact of operating conditions, membrane type, and antiscalant effectiveness on membrane mineral salt scale formation. The study focused on low-pressure reverse osmosis (RO) membrane desalting of brackish water with high potential for scaling by calcium sulfate dihydrate (gypsum). Gypsum scale fo...

High levels of accumulated phosphorus (P) in soils of the Delmarva Peninsula are a major source of dissolved P entering drainage ditches that empty into the Chesapeake Bay. The objective of this study was to design, construct, and monitor a within-ditch filter to remove dissolved P, thereby protecting receiving waters against P losses from upstream areas. In April 2007, 110 Mg of flue gas desul...

The dissolution pattern of alpha and beta activity from gypsum sample when leached with 50,100,150ml of rain water,at different time intervals was determined. The dissolution rate increases if the solid to liquid ratio(gypsum to rain water volume) increases.It also increases with time , even though faster in the initial stages, slower in the subsequent stages. The dissolution rates are also inf...