Solution pressure

Major models for the mechanism by which pressure solution occurs can be divided into those that favor dissolution in a thin film of solution as a result of 

The timing of the dolomitization of carbonate rock bodies and emplacement of dolomite cements has been one of the more controversial aspects of the dolomite problem. Most of the basic factors controlling dolomite formation, where were discussed in Chapters 6 and 7, also apply to dolomite formation during the later stages of diagenesis. However, the extended periods of time, the solution compositions likely to be encountered, and the elevated temperature and pressure that occur during deep burial provide highly favorable conditions for dolomite formation. 

Sutured Seam Solution Styolites, Grain Contact Solution Sutures 

Pervasive Solution-Dolomitization Clean limestones without resistant elements 

Uniform stress Non-unitorm Non-uniform Fitted lens and reepon- responsive- stress response 

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This kind of pressure solution / precipitation is active over prolonged periods of time and may almost totally destroy the original porosity. Precipitation of material may also occur in a similar way on the surface of fault planes thus creating an effective seal via a process introduced earlier as diagenetic healing. 

Once the above restrictions on isotope, solubility, chemical lability and paramagnetism are met, then a very wide range of samples can be investigated. Gases can be studied, especially at higher pressures. Solutions for... 

Simonson J M and Mesmer R E 1994 Electrolyte solutions at high temperatures and pressures Solution Calorimetry, Experimental Thermodynamics yo IV, ed K N Marsh and PAG O Hare (Oxford Blackwell)... 

Temperature The temperature of the extraction should be chosen for the best balance of solubility, solvent-vapor pressure, solute diffusivity, solvent selectivity, and sensitivity of product. In some cases, temperature sensitivity of materials of construction to corrosion or erosion attack may be significant. 

Mobile phases with some solvating potential, such as CO2 or ammonia, are necessary in SGC. Even though this technique is performed with ambient outlet pressure, solutes can be separated at lower temperatures than in GC because the average pressure on the column is high enough that solvation occurs. Obviously, solute retention is not constant in the column, and the local values of retention factors increase for all solutes as they near the column outlet. 

Associated gas is natural gas found in contact with oil accumulations in the same reservoir. This gas may be dissolved in the oil under reservoir temperatures and pressure (solution gas) or may form a cap of free gas above the oil in the reservoir (gas cap gas). 

The equation of Krichevsky and Ilinskaya can readily be extended to high-pressure solutions of a gas in a mixed solvent, as shown by O Connell (01) and discussed briefly by Orentlicher (03). This extension makes it possible to predict the behavior of simple multicomponent systems using binary data only. 

In the original equation of van Laar, the effective molar volume was assumed to be independent of composition this assumption implies zero volume-change of mixing at constant temperature and pressure. While this assumption is a good one for solutions of ordinary liquids at low pressures, it is poor for high-pressure solutions of gases in liquids which expand (dilate) sharply as the critical composition is approached. The dilated van Laar model therefore assumes that... 

In the other three membrane processes, for example, in RO, a membrane is mounted in an apparatus so that a two-section compartment is formed. Contaminated water is pressurized and circulated through the high-pressure-solution compartment. Water permeates to the low-pressure side and is removed. The concentrated brine is removed separately. 

Sibley, D. F. and H. Blatt, 1976, Intergranular pressure solution and cementation of the Tuscarora orthoquartzite. Journal of Sedimentary Petrology 46, 881-896. 

Pressure solution The dissolution of deeply buried solids in marine sediments caused by the increase of mineral solubfiity as a result of increasing pressure. 

SPIN-COATING Polymer composition Molecular weight Solvent boiling point Solvent vapor pressure Solution viscosity Solution concentration Spinning speed Acceleration Temperature Humidity Filtration... 

Evidence from drill core and microstructure studies indicate that euhedral, zoned arsenopyrite grains tend to be clustered, and mantled by pyrite (Fig. 4), and their distribution is structurally controlled. These textures are interpreted to represent pressure solution as the main deformation mechanism during Di. This interpretation is supported by serrated pyrite boundaries (Fig. 4) and pyrite-bearing veins. However, locally unstrained euhedral pyrite porphyroblasts overprint Di and D2 structures, implying a late-stage post-D2 growth (Fig. 4). 

A theoretical study of factors which affect pneumatic nebulizers (nebulizer geometry, capillary diameter, temperature fluctuations, gas pressure, solution viscosity, etc.] has been published by Heineman (24). Ultrasonic nebulization (which produces both smaller droplets and a narrower droplet size distribution] continues to attract attention (93, 95). 

It has therefore been assumed that a virial type of equation can relate the concentration C of the intracrystalline guest to the osmotic pressure (solution thermodynamics) or mean hydrostatic stress intensity (volume filling of pores) (9)... 

In many cases, the linear low-density polyethylene (LLDPE) produced in low-pressure processes competes for the same market as LDPE. For this reason, in Figure 8.2-7 capital- and operation costs of the high-pressure polymerization are compared with those of a low-pressure solution process having the same capacity. Also, the production costs of the low-pressure process are dominated by the costs of the monomer, but some differences can be noted which are typical for the economics of low- and high-pressure processes. 

Above all, the total costs of the low-pressure solution process are 1,393 DM/t compared to 1,491 DM/t of the high-pressure polymerization, which is a difference of 7%. However, it must be mentioned that the average European sales prices of standard film-grades LDPE in recent years have been higher by 100 to 200 DM/t than those of LLDPE [3]. 

Drugs and organic additives can be dissolved in supercritical solvents, while pigments and inorganic additives may be suspended in such systems. It proved to be possible [51] to deposit these components into polymer fibres and films by treating the polymer with such a high-pressure solution or suspension of the additive. The time necessary to deposit a pigment into a polymer fibre in this way proved to be of the order of 15-30 minutes, e.g., for polyester fibres. 

Fig. 11-1. Bubble-point pressure —solution gas-oil ratio correlation Copyright 1947 Chevron Oil Field Research Co., with permission.)...

Figure 11-1, page 297, Bubble-Point Pressure-Solution Gas-Oil... 

Vapor-Removal System. Water vapor may be removed from the freezer by several means a compressor, a steam ejector, a condenser, or absorption into a low vapor pressure solution. A water vapor compressor does not easily permit variable... 

Its function is to expand the pressurized solution to separate the "solvent gas" from dissolved extracted components. If a fixed restrictor is used, the mass flow rate of the fluid changes as a function of pressure (density) mass flow can increase by a factor of 25 as pressure is increased from 80 to 400 bar (24). Not only are the pressure and flow coupled, the coupling is via a static conduit whose dimensions are imprecisely controlled during an extraction (partial plugging by particulates and precipitated components, temperature) and from component to component during maintenance replacements. This results in a lack of control in operating parameters (density) and timed sequences (via flow rate and time). A variable restrictor whose dimensions are set and adjusted by an electronic feedback control loop is an alternative solution. 

Use of HTU and K a Data In estimating the size of a commercial gas absorber or liquid stripper it is desirable to have data on the overall mass-transfer coefficients (or heights of transfer units) for the system of interest, and at the desired conditions of temperature, pressure, solute concentration, and fluid velocities. Such data should best be obtained in an apparatus of pilot-plant or semiworks size to avoid the abnormalities of scale-up. Within the packing category, there are both random and ordered (structured) packing elements. Physical characteristics of these devices will be described later. 

Osmotic pressure, a colligative property, depends on the concentration of solute (neutral molecule or ionic species) that contributes to the osmotic pressure. Solutions of different concentrations having the same solute and solvent system exhibit an osmotic pressure proportional to their concentrations. Thus a constant osmotic pressure, and thereby a constant influx of water, can be achieved by an osmotic delivery system that results in a constant release rate of drug. Therefore, zero-order release, which is important for a controlled release delivery system when indicated, is possible to achieve using these platforms. In 1974,... 

Ghoussoub, J. and Leroy., Y. (2001) Solid-fluid phase transformation within grain boundaries during compaction by pressure solution, J. Mech. Phys. Solids 49, 2385-2430... 

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