Electrical and Thermal Properties of Soils Research Papers (original) (raw)
Soil resistivity measurements are an important parameter employed in the designing earthing installations. Thus, the knowledge of soil resistivity with respect to how it varies with related parameters such as moisture content, temperature... more
Soil resistivity measurements are an important parameter employed in the designing earthing installations. Thus, the knowledge of soil resistivity with respect to how it varies with related parameters such as moisture content, temperature and depth, at the intended site, is very vital in order to determine how the desired earth resistance value can be attained and sustained over the life of the installation with the lowest cost and effort. The relationship between corrosion and soil resistivity has been investigated in this work. Various soil samples; Sand, Gravel, Loam, Clay, and Silt, were collected from different spot within the vicinity of Ogbomosho land, Nigeria. The resistivity of the soil sample was determined through the Wenner method. The result shows that clay sample has resistivity ranging between 500 and 2000 Ω cm which indicates high corrosion potential while sand sample with resistivity in the range of 10,000 to 500,000 Ω cm indicates low corrosion potential. Corrosion of the soil samples was found to be enhanced by low resistivity and low hydraulic conductivity in soils. .
The paper presents a mechanical model for non-isothermal behaviour of unsaturated soils. The model is based on an incrementally non-linear hypoplastic model for saturated clays and can therefore tackle the non-linear behaviour of... more
The paper presents a mechanical model for non-isothermal behaviour of unsaturated soils. The model is based on an incrementally non-linear hypoplastic model for saturated clays and can therefore tackle the non-linear behaviour of overconsolidated soils. A hypoplastic model for non-isothermal behaviour of saturated soils was developed and combined with the existing hypoplastic model for unsaturated soils based on the effective stress principle. Features of the soil behaviour that are included into the model, and those that are not, are clearly distinguished. The number of model parameters is kept to a minimum, and they all have a clear physical interpretation, to facilitate the model usefulness for practical applications. The step-by-step procedure used for the parameter calibration is described. The model is finally evaluated using a comprehensive set of experimental data for the thermo-mechanical behaviour of an unsaturated compacted silt.
Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in toluene with an overall yield from c.a. 7% to 20%. A significant difference in the absorption of μ -waves by the expanded graphite and... more
Few layer graphene (FLG) was synthesized by μ -wave assisted exfoliation of expanded graphite in toluene with an overall yield from c.a. 7% to 20%. A significant difference in the absorption of μ -waves by the expanded graphite and toluene allowed a rapid heating of the medium. The number of FLG sheets varies from 3 to 12, while the lateral size of the sheets exceeds few μ ms. The obtained FLG exhibits very low resistance with average value of 1.6 k Ω (500 Ω minimum) which is comparable to that of high quality graphenes synthesized by CVD methods, and lower than numbers of exfoliated graphenes.