Movement of liquid

Internal diffusion may be defined as the movement of liquid or vapor through a sohd as the result of a concentration difference. 

Liquid Diffusion The movement of liquids by diffusion in soUds is restricted to the equihbrium moisture content below the point of atmospheric saturation and to systems in which moisture and solid are mutually soluble. The first class apphes to the last stages in the diying of clays, starches, flour, textiles, paper, and wood the second class includes the diying of soaps, glues, gelatins, and pastes. 

The movement and storage of solids is usually more expensive than the movement of liquids and gases, which can be easily pumped down a pipeline. The best equipment to use will depend on a number of factors ... 

Electroosmosis is an electrokinetic effect, so a direct electric potential causes a movement of liquid through stationary particles. From primary electrode reactions,... 

The streaming potential (Dorn effect) relates to a movement of liquid that generates electric potential, and electroosmosis occurs when a direct electric potential causes movement of the liquid. The sedimentation potential relates to sedimentation (directed movement) of charged particles that generates electric potential, and electrophoresis occurs when a direct electric potential causes a movement of charged particles. 

With regard to the movement of liquid versus particles under direct current, electrophoresis is the reverse of the effect of electroosmosis.33 If particles move through a liquid that is stationary, this is called electrophoresis conversely, if the liquid moves through particles that are stationary, that is called electroosmosis. 

A pipe transporting liquid is shown in Figure 4-6. A pressure gradient across the pipe is the driving force for the movement of liquid. Frictional forces between the liquid and the wall of the pipe convert kinetic energy into thermal energy. This results in a decrease in the liquid velocity and a decrease in the liquid pressure. 

Dike An embankment or ridge, natural or man made, used to control the movement of liquids, sludges, solids or other materials. An overflow dike would be constructed in a fashion to allow the uncontaminated water to flow unobstructed over the dike keeping the contaminant behind the dike. An underflow dike allows the uncontaminated water to flow unobstructed under the dike keeping the contaminant behind the dike. 

Manual sampling techniques can introduce error by virtue of variations in strength and size of the human hand, from analyst to analyst. As a result, the pulling velocity through the filter may vary considerably. Too rapid a movement of liquid through the filter can compromise the filtration process itself. 

Sarr MG, Kelly KA. Patterns of movement of liquids and solids through canine jejunum. Am J Physiol 1980 239 G497—G503. 

This free movement of liquid through the silica gel allows for complete solution of the absorbed substances. 

Pulsed volume is the product of the amplitude, frequency, and cross-sectional area of the column, representing therefore the rate of movement of liquid by pulsing. It is expressed, for example, as cubic foot per hour (sometimes as cubic foot per hour per square foot). 

Impervious graphite centrifugal pumps, pipe fittings, and valves were developed because most chemical processes require the movement of liquids. Graphite pipe and fittings in sizes ranging from 25 to 635 mm ID are used to convey corrosive fluids. 

The nature and sizing of equipment depends on the economic values and proportions of the phases as well as certain physical properties that influence relative movements of liquids and particles. Pressure often is the main operating variable so its effect on physical properties should be known. Table 11.1 is a broad classification of mechanical processes of solid-liquid separation. Clarification is the removal of small contents of worthless solids from a valuable liquid. Filtration is applied to the recovery of valuable solids from slurries. Expression is the removal of relatively small contents of liquids from compressible sludges by mechanical means. 

Figures la and lb represent typical gas-liquid and liquid-liquid interfaces at equilibrium. Assuming that gas, G, consists of ail and vapor of the liquid. L. at equilibrium, there is continuous movement of liquid molecules through the gaseous interfacial region Rq because rates of evaporation and condensation at the interface 1q are equal (Fig. 1), Liquid...

Electro-osmosis - the movement of liquid relative to a stationary charged surface (e.g. a capillary or porous plug) by an applied electric field (i.e. the complement of electrophoresis). The pressure necessary to counterbalance electro-osmotic flow is termed the electro-osmotic pressure. 

The ions in the mobile part of the double layer show a net movement in a direction opposite to that of the particle under the influence of the applied electric field. This creates a local movement of liquid which opposes the motion of the particle, and is known as electrophoretic retardation. It is allowed for in the Henry equation. 

The hollow nano-objects may be synthesized by the joint evaporation of carbon and a metal component in liquid. These nano-objects are formed when products get into the zone of high plasma temperatures repeatedly. This process may be presented as that proceeding in two stages. At the first stage a metal crystal with the more thermally stable surface film forms. At the second stage the product gets repeatedly into the zone of high temperatures (up to 12000 K) due to the turbulent movement of liquid with this product within the reactor (Fig. 3). This results in evaporation of metal from the thermally stable shell and formation of the nano-scaled hollow structure (Fig. 4). 

The major movement of liquid and gaseous raw materials and products within a plant to and from the point of shipment is done by pipeline. Many petroleum plants also transport raw materials and products by pipeline. When this is done, local and federal regulations must be strictly followed in the design and specification of the pipeline. 

Foam can be obtained also by simultaneous movement of liquid and gas in a tube, filled up with spherical particles (for example, polystyrene grains [46], beadpacks [49]), in coarse-pored medium [47] or movement through natural soil, such as sand packs) [48]. These ways of foam formation are used in modelling of enhanced oil recovery processes or controlling porous media permeability to gas [e.g. 48,50],... 

The methods of avoiding maldistribution during the drying step are as follows (1) dry the monolith evenly, (2) dry in a time less than that needed for the liquid to redistribute, (3) prevent any movement of liquid, and (4) prevent any movement of the catalyst precursor. 

When drying (or, in freeze drying, solidification and then drying) of the solvent takes more than a few minutes, it is highly recommended to dry (freeze) horizontally, while continuously rotating the monolith around its axis to prevent movement of liquid by gravity. 

The following terms are generally used to describe the pulse action Frequency is the rate of application of the pulse action, cycles/time. Amplitude is the linear distance between extreme positions of the liquid in the column (not of the pulser) produced by pulsing. Pulsed volume = amplitude x frequency X column crosssectional area = volumetric rate of movement of liquid, expressed as volume/time or vol-ume/(time-area). 

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