Density and Water Content

The nuclear backscatter densitometer may be used either as a conventional gamma-gamma log of the type used for petroleum exploration (Threadgold, 1980) or in a smaller version for use by itself in bays and harbors to determine the bulk density of the very soft top soils or in conjunction with a cone penetrometer (Nieuwenhuis and Smits, 1982). 

An alternate method exists to determine in situ bulk density usually only in very shallow water such as bays and estuaries, without the necessity of using radioactive isotopes. To accomplish the electrical resistivity of the soil and also of the pore water (to correct for variations in salinity) is measured using two probes (Rietsema and Viergever, 1979). This is a convenient measurement, although the equipment may be somewhat complicated to use because of having to use two separate probes to obtain one measurement in addition, the laboratory calibration procedure is not simple. What appears to be a more versatile device has been described by Bennett et al. (1983). 

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TG data, water contents and densities for phases in Portland... 

Compaction is the oldest, and in its many forms the most used, method for modifying soil properties. On large projects, shallow compaction processes begin with laboratory tests which define the related water content and density that will provide adequate support for the proposed use. Economic factors then determine the type of equipment to be used, from among those which can produce the desired results. Field density tests are then used to measure the progress of field work, and to verify that design values have been attained. 

The mixed oxides cannot be handled as loose bulk. material because the water content and density could not be assured. 

Transport properties of hydrated PFSA membranes strongly depend on nanophase-segregated morphology, water content, and state of water. In an operational fuel cell, these characteristics are indirectly determined by the humidity level of the reactant streams and Faradaic current densities generated in electrodes, as well as the transport properhes of catalyst layers, gas diffusion layers, and flow... 

So HB, Nye PH. 1989. The effect of bulk density, water content and soil type on the diffusion of chloride in soil. Journal of Soil Science 40 743-749. 

Millet determined self-diffusion coefficients for Na and Cs+ ions in hydrated 1200 EW membranes using conductivity measurements and the Einstein equation, D+ = u+kT, where u+ is the absolute mobility of the given cation. u+ can be derived from the equivalent conductivity according to A = 0+IC+ = Fu+, where 0+ is the specific conductivity, C+ is the cation concentration (calculated on the basis of the dry membrane density, EW, and the water content), and F is the Faraday constant. The values of D+ determined via these conductivity measurements... 

In contrast to soft biologies, whose mechanical properties primarily depend upon the orientation of collagen fibers, the mechanical properties of mineralized tissues, or hard biologies, are more complicated. Factors such as density, mineral content, fat content, water content, and sample preservation and preparation play important roles in mechanical property determination. Specimen orientation also plays a key role, since most hard biologies such as bone are composite structures. For the most part, we will concentrate on the average properties of these materials and will relate these values to those of important, man-made replacement materials. 

Cannon powder is manufactured by kneading in an edge runner followed by pressing the cake to a high density. Afterwards the mass is corned, moistened to 3-3.5% water content and pressed again into cakes at a pressure of 100 kg/cm2. 

Figure 6. Charge storage utilization versus current density at —20°C for various initial water contents and electrode thickness, (reproduced with permission from Thompson et al.10)...

Highly water soluble drugs, as they are typical for oral administration, can be released from polymer beads with low (< 10%) water- but high ethanolswelling capacity at controlled rates, for up to 8 hours. The release of oxprenolol-HCl (77% water solubility) and diclofenac Na (2.6% water solubility) from drug loaded monoliths is a function of water content and crosslink density. By partial extraction of the drug loaded beads the release can be further slowed down and, in the case of oxprenolol-HCl, delayed for several hours the delay is dependent on water content of the polymer and is the result of the formation of a hydrophobic surface membrane. 

Starch slurry make-down systems are designed to prepare a uniform suspension, using batch or continuous systems. In modem paper mills, automated batch or continuous systems are used. Water content and bulk density will affect the flow of dry starch.90 In the batch slurry system, weighed increments of starch are drawn from the silo and periodically added to a measured quantity of water in the make-up tank. The suspension is screened and automatically pumped to a larger storage tank on demand by a level transmitter. Continuous make-down of starch slurry is accomplished by simultaneously feeding starch and water at controlled rates into the slurry make-down tank. The dry starch is metered with a volumetric screw feeder. The slurry is screened before dispersion by batch or continuous cooking. 

The weight and strength properties of wood, together with the behavior of wood in response to weather, chemical treatment, fire, or microbial organisms, are influenced greatly by the wood s water content and the mass of wood tissue per unit volume (its density). The physical characteristics of wood tissue at given levels of moisture and density will be given specific attention in Chapter 3. However, some basic aspects of wood physics are included here to provide a more comprehensive introduction to the technical nature of solid wood. 

Some other authors also reported [32] higli velocity of detonation 8500 8510 m/s with cartridges of 6.4 cm diameter, pressed to density 1.59 1.6, Price [33] found that the infinite charge diameter detonation velcKity can be expressed by the equation D = 5390 (p HN 100) where p UN is the density in g/cm. Kurbangalina and Tinokhin [34] found that the critical diameter increases with an increase of water content and the rate of detonation can vary from 2000 to 8000 m/s. 

Hemic Organic Material. Moderately decomposed with intermediate bulk density, fiber content, saturated water content, and variable acidity. 

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