OBJECTIVE To investigate the variation of the strength of gypsum-bonded dental investments with burnout temperature. METHODS The disc-rupture test was employed at burnout temperatures ranging from 450 to 800 degrees C for four products (Beauty Cast, Cristobalite, Novocast (all WhipMix) and Deguvest California (Degussa)). In this test, an investment disc is created inside an investment mold su...

Two field trials were sampled to investigate the changes to soil solution chemical properties of a yellow sandplain soil with an acidic subsoil following the application of gypsum and lime to the soil surface in 1989. The soils were sandy textured and located in a region of low annual rainfall (300-350 mm). Soil was sampled annually to a depth of 1 m and changes in soil solution composition wer...

today's, adverse effects of off-site erosion, namely damages received from sediment, is a serious bioenvironmental problem. one of the methods for temporary soil stabilization before permanent rehabilitation of vegetation cover, especially on slopes, for mitigating of bioenvironmental contaminants, is using materials having property to cementate the dispersed particles on the soil surface....

In the accretion process of planetesimals, there could be a lot of bodies with heterogeneous internal structures by pressure sintering, melting and gravity differentiation. They might have a core-mantle structure such as silicate core-porous silicate mantle or metal core-rock mantle. Therefore, we should consider a collisional phenomenon not only of a homogenous body but also of a core-mantle b...

This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal ...

combustion flue gas desulfurization (FGD) using lime or limestone are the primary processes employed to reduce sulfur dioxide (SO 2 ) emission from coal combustion. However, these processes generate voluminous solid wastes, i.e., pyrite and gypsum, that are usually landfilled, occupying thousands of acres of land and creating serious land and water pollution problems due to the release of acids...

Sulfur and oxygen isotopes were employed to identify SO42- sources in surface water and groundwater in the Babu subterranean river basin (BSRB). Our study revealed SO42- enrichment in the BSRB waters compared with adjacent areas. The SO42- in some samples originated mainly from precipitation; in others, it was derived mainly from sulfide dissolution in coal seams or from gypsum dissolution. In ...