The effects of a number of design parameters have been investigated including the types of cavity insulation, resilient channels, gypsum board thickness, the number of gypsum board layers, stud arrangements, and type of framing. The results have shown that the main factors that affected the performance of stud wall assemblies were the type of insulation and the number of gypsum board layers. In...

Paris (CaS04)2H20. Excessive heat convey it into anhydrous calcium sulphate CaB^< which takes up water very slowly and does D?. harden and set. 2CaS04.2H20 = (CaSW 2H20+3H20. (CaS04)2H20 = 2CaS 04H2U, Commercial plaster of Paris is manufacture from impure gypsum and therefore contains tn impurities present in the gypsum such as alum10^ iron, silicates, carbonates, lime, etc., which be recognize...

iii DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disc...

Mineralogical processes taking place close to equilibrium, or with very slow kinetics, are difficult to quantify precisely. The determination of ultraslow dissolution/precipitation rates would reveal characteristic timing associated with these processes that are important at geological scale. We have designed an advanced high-resolution white-beam phase-shift interferometry microscope to measur...

Human arsenic exposure from rice consumption is a global concern. Due to the vast areas of naturally contaminated soils in rice-producing regions, the only possibility for reducing hazardous exposure is to prevent As uptake and translocation to rice grain. Sulfur inhibits As mobility both in soil and plant, indicating that soil S content may be a primary factor controlling As uptake; indeed, gy...

Introduction: Recent and on-going remote and in situ observations indicate that sulfates are present in significant abundances at various locations on Mars [1-5]. In addition, the scheduled Mars Reconnaissance Orbiter (MRO) will be equipped with an imaging spectrometer (CRISM) that will return hyperspectral data at higher spatial resolution [6] than the OMEGA instrument on the Mars Express Miss...

PURPOSE To evaluate the efficacy of sodium hypochlorite (1 : 10) and iodophor disinfectants on alginate impressions along with their effect on the survived bacterium count on the gypsum cast. MATERIALS AND METHODS Four alginate impression on each dentate patients were made, of which Group I were not washed or disinfected, Group II impressions were merely washed with water, Group III were disi...

This research assessed the use of gypsum (CaSO42H2O) as a skeleton builder for sludge dewatering since polymer conditioning of sludge affected only the rate of water release, not the extent of dewatering. The use of gypsum as a physical conditioner, in association with a polymer, could improve sludge filterability. More significantly, gypsum serves as a skeleton builder, forming a permeable an...

The threat of P transport from land applied manure has resulted in water quality concerns. Research was conducted to evaluate gypsum as a soil amendment applied to grass buffer strips for reducing soluble P in surface runoff. A simulated concentrated flow was created in an established tall fescue (Festuca arundinacea Schreb.) pasture. Poultry litter (PL) was applied at a rate of 250 kg N ha(-1)...