Formed under elevated temperature and pressure

FAA FA FBC FC FEBEX FFFF FGD FP FSU FT FTIR FUETAP Flame atomic absorption Fly ash Fluidized bed combustion Filter cake Full-scale engineered barriers experiment (in crystalline host rock) Flow-field flow fractionation Flue gas desulphurization Fission products Former Soviet Union Fourier transforms Fourier transformed infrared spectroscopy Formed under elevated temperature and pressure... 

As Table 17.10 indicates, the G values in Ceramicrete waste forms are lower than in most other grout systems and comparable to that in FUETAP (Formed Under Elevated Temperature and Pressure) concrete. These results indicate that the gas yield is minimal in the Ceramicrete waste forms. 

G. Dole, G. Rogers, M. Morgan, D. Stinton, J. Kessler, S. Robinson, and J. Moore, Cement-based radioactive waste hosts formed under elevated temperatures and pressures (FUETAP concrete) for Savannah River Plant high-level waste. Report No. ORNL/TM-8579 (Oak Ridge National Laboratory, 1983). 

Two principal PS foams that are fabricated are extruded foam and expanded for molded foams. PS foams are light, closed-cell foams with low thermal conductivities and excellent water resistance. They provide for low-temperature insulation and buoyancy media. The extruded PS foam is fabricated as billets and boards. They are made by extruding molten PS containing a blowing agent, under elevated temperature and pressure, into the atmosphere, where the mass expands. Billets and boards can be used directly or can be cut into many different forms.254... 

A second interpretation of carbonaceous chondrites is as primary condensates of the solar nebula. By this view, their hydrolytic alteration is due to melting in cometary nuclei during close passes with the Sun, or due to transient heating events by shock waves or collisions (McSween, 1999). Other carbonaceous chondrites show metamorphic alteration with minerals similar to those in Earth formed during deep burial under elevated temperatures and pressures (Brearley, 1999). Like soils and paleosols on Earth and Mars, carbonaceous chondrites demonstrate the great antiquity of hydrolytic weathering in dilute acidic solutions, presumably of carbonic acid derived from water vapor and CO2. These remain the principal gases released from volcanoes, and soils remain important buffers for this environmental acid. 

Weathering is accelerated because most of the minerals being weathered were formed at elevated temperatures and pressures and are thermodynamically unstable under ambient conditions. Defend this statement with an example that considers the composition of a typical natural water and the theoretical solubility of... 

Pan et al. utilized melted plastics to fabricate microlenses. At the melting temperature, the hot melted plastic is intruded into circularly shaped holes and stopped at the desired depth under elevated temperature and pressure. After cooling down, the microlenses are formed. This is called a hot intrusion process [9]. 

The product of this reaction can be removed as an azeotrope (84.1% amide, 15.9% acetic acid) which boils at 170.8—170.9°C. Acid present in the azeotrope can be removed by the addition of soHd caustic soda [1310-73-2] followed by distillation (2). The reaction can also take place in a solution having a DMAC-acetic acid ratio higher than the azeotropic composition, so that an azeotrope does not form. For this purpose, dimethylamine is added in excess of the stoichiometric proportion (3). If a substantial excess of dimethylamine reacts with acetic acid under conditions of elevated temperature and pressure, a reduced amount of azeotrope is formed. Optimum temperatures are between 250—325°C, and pressures in excess of 6200 kPa (900 psi) are requited (4). DMAC can also be made by the reaction of acetic anhydride [108-24-7] and dimethylamine ... 

Ruthenium Hydroxide,187192 To an 1% aqueous solution of ruthenium chloride heated to 90-95°C is added an 5% lithium hydroxide solution dropwise under vigorous stirring until the pH of the supernatant liquid becomes 7.5-7.8. Addition of a few drops of the lithium hydroxide solution is usually necessary to prevent the pH of the liquid from becoming more acidic on continued stirring for a further 10-20 min. The black precipitate formed is collected on a filter paper, washed repeatedly with hot distilled water until the filtrate becomes almost neutral, and then dried in vacuo at room temperature. The dried hydroxide is pulverized into fine particles and can be used for hydrogenation at elevated temperatures and pressures without prereduction. 

Material supplied to the ocean originates from tlie atmosphere, rivers, glaciers and hydrothermal waters. The relative importance of these pathways depends upon the component considered and geographic location. River runolf commonly constitutes the most important source. Transported material may be either dissolved or particulate, but discharges are into surface waters and confined to coastal regions. Hydrothermal waters are released from vents on the seafioor. Such hydrothermal waters are formed when seawater circulates into the fissured rock matrix, and under conditions of elevated temperature and pressure, compositional changes in the aqueous phase occur due to seawater - rock interactions. This is an important source of some elements, such as Li, Rb and Mn. The atmosphere supplies particulate material globally to the surface of the ocean. In recent years, this has been the most prominent pathway to the World... 

A number of groups have prepared vanadium phosphate catalysts using hydro-thermal synthesis [92, 93, 128-130]. Using standard reaction mixtures, Dong and coworkers [128] showed that at elevated temperatures and pressures different materials are synthesized from those obtained under reflux conditions. Pressure did not seem to affect the product formed, but as the temperature increased to >200°C further reductions occurred and products formed. However, these materials were not found to have enhanced catalytic activity compared to traditionally prepared materials. At lower temperatures, hydrothermal syntheses have produced catalysts with comparable activity to those prepared under standard conditions [92, 93, 129, 130]. Taufiq-Yap and coworkers [129] found an enhancement in activity for hydrothermaUy prepared catalysts and suggested this was due to a modification in the redox behavior of the catalysts evidenced by TPO/TPR experiments. 

Trifluorophosphine complexes of nickel, palladium, and platinum have been obtained by direct reaction of PF3 with the metal at elevated temperatures and pressures (172). Similarly several fluorophosphine complexes of zero-valent nickel can be made under very mild conditions (60°C) using metallic nickel formed by decarboxylation of nickel oxalate... 

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