Water, volume, void

Let us first consider the synergistic elfect that water has on void stabilization. It is likely that a distribution of air voids occurs at ply interfaces because of pockets, wrinkles, ply ends, and particulate bridging. The pressure inside these voids is not sufficient to prevent their collapse upon subsequent pressurization and compaction. As water vapor diffuses into the voids or when water vapor voids are nucleated, however, there will be an equilibrium water vapor pressure (and therefore partial pressure in the air-water void) at any one temperature that, under constant total volume conditions, will cause the total pressure in the void to rise above that of a pure air void. When the void pressure equals or exceeds the surrounding resin hydrostatic pressure plus the surface tension forces, the void becomes stable and can even grow. Equation 6.5 expresses this relationship... 

Bulk density of soil is the soil weight per unit volume, including water and voids. It is used in converting weight to volume in the mass balance calculations. 

Measure the volume of the filtrate this gives the volume of supernatant water and voids. 

Volume of supernatant water = x ml Volume of resin and voids ml Volume of supernatant water and voids =. ml... 

Mitchell Procedure Mitchell (1977) presented an unpublished consulting report which addressed computing the water content, void ratio, unit weight, and degree of saturation for soils with high salt content. Mitchell defines a readily measured quantity (r) being the mass of the dissolved salt (M J per unit volume of solution which is an easily... 

The apparent specific gravity (G J is the ratio of the mass in air of a unit volume of an impermeable material at a stated temperature to the mass in air of equal density of an equal volume of gas-free distilled water at a stated temperature. In other words, the aggregate apparent specific gravity does not include the volume of water-permeable voids in the aggregate (Asphalt Institute MS-4 2007). 

The clean critical size, reflector savings, and temperature coefficients were measured tor two 1.8% enriched cores with water to uranium volume ratios of 4.4 and 6.0 (excluding control rod water channels and axial water gaps). In addition the clean critical size was obtained for the 1.59% enriched core. The clean critical size and reflector savings were also measured for the 1.8% cores containing 18% and 14% voids (ratio of void to water plus voids), respectively. The voids were obtained by inserting low density (9 Ib/ft ) foamed polyurethane void simulators between fuel rows to obtain a uniform displacement of water. These simulators are coated to reduce wafer absorption to a negligible value. The measurements are summarized in Table I. 

However, it appears that none of the non-destructive tests currently employed directly correlate with any critical failure property. Most industrial test techniques such as through-transmission and pulse-echo ultrasonics, sonic vibration techniques. X-ray radiography, thermal inspection methods, holography, liquid penetrants, etc. basically attempt to find defects in the joint. Such defects may arise from several sources. Some defects arise from porosity, cracks or voids in the adhesive layer or at the interface and are typically filled with air they will simply be referred to as voids in the present discussions. However, during the service life of the joint such voids may fill with water which makes them far more difficult to detect since, for example, water has a much higher acoustic, impedance than air. Also, zero-volume voids, or debonds, may occur when the adhesive and substrate are in contact but no... 

In order to convert the measured reactivity worth of a cubic centimeter of void into worth per percent void volume, the core water volume must be calculated. The core height is 24 in., and it is built in the annular region between a 24-in.-OD and 36-in.-ID tank. The total annular volume is... 

Rapid heating of either borax decahydrate or pentahydrate causes the crystal to dissolve before significant dehydration, and at about 140°C, puffing occurs from rapid vaporisation of water to form particles having as high as 90% void volume and very low bulk density (78). 

Phenohc resins (qv), once a popular matrix material for composite materials, have in recent years been superseded by polyesters and epoxies. Nevertheless, phenohc resins stiU find considerable use in appHcations where high temperature stabiHty and fire resistance are of paramount importance. Typical examples of the use of phenoHc resins in the marine industry include internal bulkheads, decks, and certain finishings. The curing process involves significant production of water, often resulting in the formation of voids within the volume of the material. Further, the fact that phenoHcs are prone to absorb water in humid or aqueous conditions somewhat limits their widespread appHcation. PhenoHc resins are also used as the adhesive in plywood, and phenohc molding compounds have wide use in household appliances and in the automotive, aerospace, and electrical industries (12). 

As a result of the linear expansion, the reduced volume of the dihydrate, and the evaporation of excess water, the percentage of void spaces in plaster is ca 45%, in stone 15%, and in improved stone 10%. Thus, the additional amount of water required for plaster contributes to the volume but not to the strength of the hardened material (105). 

Impression Plasters. Impression plasters are prepared by mixing with water. Types I and II plasters are weaker than dental stone (types III and IV) because of particle morphology and void content. There are two factors that contribute to the weakness of plaster compared to that of dental stone. First, the porosity of the particles makes it necessary to use more water for a mix, and second, the irregular shapes of the particles prevent them from fitting together tightly. Thus, for equally pourable consistencies, less gypsum per unit volume is present in plaster than in dental stone, and the plaster is considerably weaker. 

The amount of material in a mill can be expressed conveniently as the ratio of its volume to that of the voids in the ball load. This is known as the material-to-void ratio. If the solid material and its suspending medium (water, air, etc.) just fill the ball voids, the ratio is 1, for example. Grinding-media loads vary from 20 to 50 percent in practice, and ratios are usually near 1. 

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