High pressure environments

Jones, O.E. and Graham, R.A., Shear Strength Effects on Phase Transition Pressures Determined from Shock Compression Experiments, in Accurate Characterization of the High Pressure Environment (edited by Lloyd, E.C., National Bureau of Standards Special Publication 326, US Government Printing Office, Washington, DC, 1971, pp. 229-242. 

H. Kobayashi, T. Tamura, K. Maruta, T. Niioka, and RA. Williams 1996, Burning velocity of turbulent premixed flames in a high pressure environment, Proc. Combust. Inst. 26 389-396. 

Examples of retarders are shown in Table 10-11. They are added to prevent cement from setting too rapidly. These additives are also referred to as set retarders. Cements with retarders to prevent rapid setting may be used at the high-temperature and high-pressure environments of deep wells. Common retarders are lignosulfonate and certain carbohydrate derivatives, such as welan gum, xanthan gum, cellulose, and polyanionic cellulose. 

Suitable grades can withstand multiple heating cycles to 125°C in high-pressure environments. Trade name examples Noryl PPX. .. 

It is commonplace to assume a form of the Gibbs energy function which excludes the pressure variable for solid-state phase transformations, as the magnitude of the PAV term is small at atmospheric pressures. This is of course not the case in geological systems, or if laboratory experiments are deliberately geared to high-pressure environments. Klement and Jayaraman (1966) provide a good review of the data available at the time when some of the earliest CALPHAD-type calculations were made (Kaufman and Bernstein 1970, Kaufman 1974). Much work was also carried out on specific alloy systems such as Fe-C (Hilliard 1963) and the Tl-In system (Meyerhoff and Smith 1963). 

When diesel fuel is injected into the high-pressure environment of a combustion chamber, it must fully penetrate into the pressurized air in order to completely combust. Fuel with a low viscosity does not have enough thrust to penetrate effectively through the pressurized air and disperse completely. The result is a soft, nonpenetrating spray which does not spread throughout the chamber. Poor combustion efficiency and engine power result. 

The rate of sampling with piezoelectric sensors is limited by their physical characteristics and present technology to the millisecond range for applications in the liquid phase. The technique is versatile in that it can be used in a variety of locations. The solid state electronics necessary to operate the piezoelectric sensor are easily miniaturized, and data can be recorded continuously or periodically. A small computer with a reasonable memory could easily record data over long times. There may be some problems in deep-sea locations, simply because of the complications in packaging the sensor for high-pressure environments, although this problem may be surmountable. 

In a later paper (Ref 87) these authors examined the electrical conductivity of the products of pressed cylindrical charges of RDX. They claim that such deton products will be conductive under the existing high pressure environment regardless of whether there is chem reaction. Ershov and coworkers (Refs 83 and 69), on the other hand, claim that the chem reaction zone in a deton can be correlated with the non-equilibrium ionization observed in deton products. They find (Ref 69) that the electrical conductivity of the deton products of RDX goes thru a max of 43 (ohm-m)"1 at 0.3mm behind the deton front. They advance three possible explanations for this observation (1) high d ... 

Piezophile An organism adapted to living in high-pressure environments, such as hydro-thermal vents... 

Chemical and hydrolysis resistance insoluble in all common solvents, has excellent resistance to most of organic and inorganic liquids. It can be used in steam or high pressure environment without any degradation in properties. 

Aerometrics Eclipse is a white light blockage system designed for both liquid and gas systems. The probe head includes a light source, flow cell and photodiode. The processor can accommodate two heads covering the size ranges 2-100 pm, 10-500 pm, 20-1000 pm and 50-2500 pm. The flow cells are compatible with most liquids and can be specially adapted for high-pressure environments. 

As described earlier, the revolution in high pressure liquid chromatography arose from a number of factors a better understanding of the theory of liquid chromatography, development of new supports and the development of new instrumentation specifically designed for use in the high pressure environment. 

Two other metamorphic facies are formed on a regional scale and under unique circumstances. The blueschist facies forms in the low-temperature, high-pressure environment in the upper portion of a subduc-tion zone. Land-derived sediments accumulated deep on the cold ocean floor are driven into an area of high pressure during subduction of an oceanic plate. These rocks often look blue when seen in outcrops. 

Southwest Sciences Santa Fe, NM Diode laser-based sensors for gases, including formaldehyde, in harsh high-temperature, high-pressure environments. DOE... 

Continuous extraction of solids is not easily achieved in a high pressure environment, but can be achieved in certain cases. These favourable cases are met when the solids can be ground to a small size (below 1 mm) and a diluted suspension of the solid material in the solvent can be used. As this possibility is of fundamental importance, an experimentally verified example is treated here in some detail. 

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