Soils density

Percentage compaction usually is used to measure soil density in a fill situation. Generally, the maximum Proctor specific weight (dry, Ib/ft ), determined by a standard laboratory test, is set up as the standard for the soil. Normally, 90-100% compaction is specified. 

Other important soil properties of the ET landfill cover may be controlled by adequate design and good construction practices. The properties that govern root and plant growth and are important to design of ET landfill covers include soil density, aeration, pH, and nutrients. For a complete list of soil properties refer to Table 25.2. 

The density of soil may control the presence, absence, or density of roots found in a particular soil layer. The density of plant roots in a soil layer determines how much water plants can remove from the layer and its rate of removal. Soil compaction, in addition to inhibiting root growth, reduces soil-water-holding capacity. A model that does not consider the effect of soil density on water balance may produce significant errors in water balance estimates. 

UNSAT-H does not address the effects of soil density on plant growth and water balance. Disadvantages caused by the computational methods used to estimate soil water flow include the following (1) the model requires the user to choose from several submodels to solve the Richards equation this choice should be made by a person with training in advanced soil physics and (2) the model requires the input of several soil parameters that are difficult to estimate for the completed cover soil. 

Examination of Table 25.3 and the comments above clearly demonstrate that both HYDRUS and UNSAT-H are likely to produce very good estimates of water movement within the soil profile. However, they do not estimate snowmelt, model mixed plant communities, directly estimate surface runoff, or consider the effect of soil density on root growth and water use.14... 

Soil density effect on root growth and water use Y N N N... 

To incorporate the isotherms into a geochemical model, we save the parameters into datasets Se04 Kd.dat , Se04 Fr.dat , and Se04Xa.dat . To model the Alemi et al. (1991) configuration, we note that per kg of water there are 500 g of dry soil, or 189 cm3, taking the soil density to be 2.65 g cm-3. 

A satisfactory control of soil densities of Phytophthora spp. and related diseases was documented in several solarization studies (Pinkas et al. 1984 Lopez-Herrera et al. 1997 McGovern et al. 2000 Benlioglu et al. 2005). Pinkerton et al. (2002)... 

Inputs were provided to the cost model for an Alaskan site with an area of 10,000 fU and a soil density of 100 Ib/ft. The specific heat of the soil was 0.20 British thermal units (Btu) per pound per degree Fahrenheit. The HeatTrode centerline distance was 5 ft, and each HeatTrode was installed to a depth of 10 ft (D17162K, p. 12). 

Estimates are based on a wet soil density of 1.8 tons/yd (2.1 tons/m ) based on SITE demonstration results. Costs based on contaminated soil treated. AU costs are rounded to two significant figures, based on the sum of the individual costs before rounding. 

Density—solids Compacted soil density for 1J,Cs, (0Co, 226Ra and... 

If ps (kg m-3) is the bulk soil density, AR (Bq kg-1) the specific activity of radium in the soil, a the emanating coefficient, and A (s-1) the decay constant of radon, then PsARa atoms, or psARaX Bq of radon, enter the interstitial air per m3 of soil volume per second. At depth in the soil, the rates of entry and radioactive decay of radon are equal, so its activity in interstitial air is... 

The influence of emission of some airborne pollutants on an agricultural area has to be investigated. From an area of 10000 square meters, ten soil samples were taken from the surface soil horizon. 1 g of each sample was recently analyzed in the laboratory. This means that the results, for instance a pollutant concentration, obtained from ten 1 g samples are used to estimate the level of pollution in the whole area with a medium depth of the surface horizon of 30 cm and a medium soil density of 1.5 g cm-3. A parent population of more than 109 g has to be assessed from a total sample mass of 10 g The necessity of extrapolation over a range of several orders of magnitude indicates the problems connected with sampling process. 

Soil density ranges from 80 to 130 pounds per cubic feet. 

Particle density distribution of soil (density gradient tube)... 

Multiplying (which also has units of L kg ) by soil density (- 2.4 kg... 

Krauss, M. and Wilcke, W. 2005. Persistent organic pollutants in soil density fractions Distribution and sorption strength. Chemosphere, 59 1507-15. 

Loss of a radioactive soil density gauge or well logging gauge. 

The volatility potential (slope of the vapor pressme vs. concentration in soil organics) of GA is 2.4 x 10" mm Hg/mg/kg and its air-soil partition coefficient (for a soil density of 1.4 g/cm ) of 1 x 10 mg/m (MacNaughton and Brewer, 1994), indicate that GA will evaporate from soil into the air. Results of a field trial with GA showed 10% evaporation in 0.27 horns and 90% evaporation in 4.66 hours (Morrill et al., 1985). 

All soil gases contain a mixture of radon, thoron and actinon. Whilst the half-life of the last (5.4 sec.) is too short to interfere with Rn determinations, Tn is always present in in-situ determinations. To relate Rn and Tn emanations quantitatively to U and Th concentrations is difficult, if not impossible. Too many factors, such as radioactive disequilibrium of the series in the soil as a result of weathering, changes in the emanation efficiency due to soil density and grain size, moisture content, and distribution of radioactive particles, cause erroneous extrapolations. However, precise, quantitative results are not of prime importance in prospecting. The important point is that there be correspondence between Rn in soil emanations and U in the area nearby. That this correspondence exists has been demonstrated numerous times and is discussed in more detail below. 

Assuming that the meteorological conditions described above apply 5% of the time, that the facility operates for 30 years, and that the deposited particles become evenly mixed in the top 10 cm of the soil, calculate the metal concentration in the upper soil in ppm. Use a soil density of 200kg/m. ... 

There is no proof, liowever, that the weathered material has derived from the exact parent rock given in the table. This may explain the excess in soil vol % quartz, which, assuming quartz is not dissolved or precipitated during soil formation and that volume and weight percents are roughly equal, should not exceed about (30/75) x 100 = 40 wt % of the soil. (Densities of quartz, K-feldspar, plagioclase feldspar, and kaolinite are alt 2.60 0.05 g/cm ). 

What field tests can be used to measure soil density... 

Number of sampling points per hectare = 16 Sampling depth=3 m Soil density=2.5 tonnes/m3... 

Cs / Soil Density Detector (MC-1) / Radiation Dispersal Devices ... 

Figure 38-1. Soil density profile. (Courtesy - New Jersey State Police)...

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