... to two physical tests: T 3 CM and British polishing wheel/British pendulum, as well as three chemical/mineralogical tests: Percent silica ASTM C25, percent silica by x-ray diffraction, and loss-on-ignition (LOI). In addition, the bituminous surface courses containing these aggregates were monitored...

... Scanning electron microscopy and energy dispersive spectroscopy analysis were used to characterize the interfacial reaction layer for a system comprised of commercially pure titanium cast into an incompatible silica-containing investment mold. This layer was compared to bulk mold material...

... Silica aerogel is a low-density, transparent and porous solid that achieves vacuum-like insulating performance at a very modest vacuum (0.1 bar). Research is under way to further improve the thermal performance of this already highly insulating material by reducing the internal radiative heat...

... of electronic defect levels within the bandgap of the dielectric materials. electronic defects halfnia HR coatings laser conditioning laser damage silica zirconia Manuscript received 3-20-90 Large Area Laser Conditioning of Dielectric Thin Film Mirrors M.R. Kozlowski, C.R. Wolfe, M.C. Staggs, J.H...

... methods. The cement manufacturer would have to consider other changes to the cement to offset the increase in drying shrinkage. limestone carbonate additions drying shrinkage cement mortar bars silica C-S-H phase Lawrence D. Adams I and Ronald M. Race ~ Effect of Limestone Additions Upon...

... Today synthetic silicas are widely used in pesticide formulation. They cannot be compared with natural occurring products such as diatomaceous earth or clays. Their properties are different. Factors like pH, hydrophilic and hydrophobic character, structuring, etc are important for the use...

...-YAG laser pulses. The results are compared to the properties of the corresponding nonshifting deflectors. We investigated in stacks of Titania, Tantala, Hafnia and Zirconia in conjunction with Silica designed for retardation angles of 45° and 90°. Laser induced damage thresholds are related...

... mirror substrate. However, in both of these applications the silica may be exposed to substantial doses of ionizing radiation, either from the scattered electrons and x-rays from the laser pump or from the natural and/or enhanced on-orbit space radiation environment. This paper reports the effects...

... in the tests. The test data were used to define the general trends of the selected materials in the liquid oxygen impact test, but the conclusions require further verification by additional tests. liquid oxygen threshold levels sensitivity silicon carbide silica impact Jim L. Cunie,^ Roy S. Irani...

... Four coatings, including tungsten carbide wear-resistant and cobalt-base corrosion-resistant materials, were tested for abrasion and erosion performance in silica sand and in Alundum slurries. A 1018 carbon steel sample was also tested for comparison. The abrasion tests were conducted with a wet...

... From about 1940 alkalies have been known as a potentially important species in concrete, despite being a minor cement constituent. The hydration reaction of silica in aggregates in concrete in the presence of alkalies, which may cause deleterious expansion, is chemically similar to the process...

... Crystalline silicon dioxide has been associated with pulmonary lung disease. A number of descriptive terms such as “amorphous silica,” “free silica,” “silica flour,” and “fumed silica” have arisen in the literature as a result of studies related to health and the silicon dioxide forms...

... This paper reviews the immunological aspects of silica and silicosis. Since crystalline silica by itself is nonantigenic, emphasis is placed on how silica can effect immunological consequences, on what immunological abnormalities are observed in both spontaneous and experimental forms...

... confidence level for the following: adsorption at 45 percent and 92 percent relative humidity; alumina + silica (Al 2 O 3 + SiO 2 ) content-expansion coefficient in saturated state; and freeze-thaw loss. Negative significant correlation was obtained between the calcium oxide (CaO) and magnesium oxide (MgO...

... for their durability by magnesium sulfate and freeze-thaw test methods. The silica and the alumina content were determined, as well as the water adsorption after treatment in 3 weight percent chloride salt solution. Isothermal expansion upon wetting of the dry treated and untreated rocks also were studied...

... nitrification nitrite organic compounds periphyton phosphate silica evaluation tests G. G. Ehrlich 1 and K. V. Slack 1 Uptake and Assimilation of Nitrogen in Microecological Systems R E F E R E N C E : Ehrlich, G. G. and Slack, K. V., "Uptake and Assimilation of Nitrogen in Microeeologieal Systems...

... A system consisting of silica fibers embedded in an aluminum matrix has been used to study the properties, behavior, and fabrication methods of a fiber reinforced metal. The stress strain behavior describes an open loop which becomes closed on subsequent stressing within the previously applied...

... microscope. High-silica values were obtained when thiocyanate and citrate were used as electrolytes in electrolyses of the Klinger and Koch type. The anomalous values were traced to oxidation of silica in the steel to silicic acid. Washing the residue with sodium carbonate eliminated this problem...