Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase (3.2.1.52) activity were monitored from inoculation to stationary phase. Regression analysis showed a good linear correlation to...

The basis for some common gypsum wallboard mold remediation practices was examined. The bottom inch of several gypsum wallboard panels was immersed in bottled drinking water; some panels were coated and others were untreated. The panels were examined and tested for a period of 8 weeks. This study investigated: (a) whether mold growth, detectable visually or with tape lift samples, occurs within...

A considerable amount of Hg is retained in flue gas desulfurization (FGD) gypsum from Wet Flue Gas Desulfurization (WFGD) systems. For this reason, it is important to determine the species of Hg in FGD gypsum not only to understand the mechanism of Hg removal by WFGD systems but also to determine the final fate of Hg when FGD gypsum is disposed. In this study, Temperature Programmed Decompositi...

The CEMHYD3D model has been extended at the University of Twente in the last ten years [1,2]. At present the cement hydration model is extended for the use of gypsum. Although gypsum was present in the model already, the model was not suitable for high contents of gypsum and did not include the transitions between the different calcium sulphate phases (anhydrite, hemihydrate and gypsum). Beside...

The CEMHYD3D model has been extended at the University of Twente in last ten years. At present the cement hydration model is extended for the use of gypsum. Although gypsum was present in the model already, the model was not suitable for high contents of gypsum and did not include the transitions between the different calcium sulphate phases (anhydrite, hemihydrate and gypsum). Besides that gyp...

Gypsum karst problems in the Permian and Triassic sequences of England have caused difficult conditions for bridge and road construction. In Northern England, the Ripon Bypass crosses Permian strata affected by active gypsum karst and severe subsidence problems. Here, the initial borehole site investigation for the road was supplemented by resistivity tomography studies. The roadway was reinfor...

The isotopic composition and mass balances of sources and sinks of sulfur are used to constrain the limnological–hydrological evolution of the last glacial Lake Lisan (70–14 ka BP) and the Holocene Dead Sea. Lake Lisan deposited large amounts of primary gypsum during discrete episodes of lake level decline. This gypsum, which appears in massive or laminated forms, displays dS values in the rang...

PURPOSE To demonstrate the noninferiority of a new toothbrush head with retractile bristles compared to traditional toothbrush heads on dental models. METHODS The new toothbrush head, mounted on manual and electrical handles, presents retractile bristle groups that can singularly retract over its entire length and offer calibrated resistance. Fourteen gypsum models of dental arches, twelve wi...

Please cite this article in press as: Brinck, E., Fr doi:10.1016/j.apgeochem.2009.09.001 Gypsum and S are applied to soils being irrigated with Na–HCO3 dominated coalbed natural gas (CBNG) produced water to protect soil structure and fertility. Wyoming law requires beneficial use of produced water and irrigation with CBNG produced water in the semi-arid Powder River Basin is becoming more commo...

Consistent use of high RSC water may deteriorate the physical properties of soil and increases pH and SAR of soil. Continuous use may reduce germination / the establishment of seedling, retards plant growth and leads to a significant reduction in yield. Therefore, a field experiment in microplots was displayed at research plot in St. John’s College, Agra to study the effect of sodic water on th...