Clay content (fraction < 2 μm) is one of the most important soil properties. It controls soil hydraulic properties like wilting point, field capacity and saturated hydraulic conductivity, which in turn control the various fluxes of water in the unsaturated zone. In our study site, the Kairouan plain in central Tunisia, existing soil maps are neither exhaustive nor sufficiently precise for water...

Clay fractions in soils from a transect of the Mazama ash deposit (6600-yr-old) contained more than 80% amorphous material. Instrumental neutron activation analysis was used to compare the trace element composition of the soil clay with the unweathered volcanic glass. The clay fractions had only 10% as much Na as the volcanic glass. Conversely, the rare earth element concentrations were about t...

The clay and non-clay minerals have been identified by XRD analysis. The non-clay minerals include quartz, crystobalite, orthoclase, microcline, plagioclase, calcite, siderite and dolomite, and the clay minerals include kaolinite (52.39%), illite (36.39%) and illite-smectite mixed layer minerals (11.21%). Kaolinite is the most dominant component in the clay mineral assemblages. The clay mineral...

High density polyethylene (HDPE)/bamboo composites with different nanoclay and maleated polyethylene (MAPE) contents were fabricated by melt compounding. The compounding characteristics, clay dispersion, HDPE crystallization, and mechanical properties of the composites were studied. The equilibrium torque during compounding decreased with use of clay masterbatch and increased with the addition ...

Column experiments were conducted to study chemical factors that influence the release of clay (kaolinite and quartz minerals) from saturated Ottawa sand of different sizes (710,360, and 240 microm). A relatively minor enhancement of clay release occurred when the pH was increased (5.8 to 10) or the ionic strength (IS) was decreased to deionized (DI) water. In contrast, clay release was dramati...

19 Clay-polymer composites were designed for use in filtration processes for disinfection 20 during the course of water purification. The composites were formed by sorption of 21 polymers based on starch modified with quaternary ammonium ethers onto the 22 negatively charged clay mineral bentonite. The performance of the clay-polymer 23 complexes in removal of bacteria was strongly dependent on...

a series of tests and also numerical analyses were conducted to explore the mechanical behavior of a mixture of coarse gravelsize particles floating in a matrix of silt, sand or clay. the research is a step forward in an ongoing investigation on behavior of composite clay, which is used as the core material of some large embankment dams all over the world. after providing the reader with an ove...

SUPERCRITICAL CARBON DIOXIDE PROCESSING OF NANO CLAYS ANDPOLYMER/CLAY NANOCOMPOSITESbyMIHAI MANITIUAugust 2010Advisor: Rangaramanujam KannanCo-Advisor: Esin GulariMajor: Chemical EngineeringDegree: Doctor of Philosophy Effective dispersion of the fillers in a polymer matrix and improvement of polymer clayinteractions are two key challenges in the field of...

-Clay-modified electrode research indicates that adsorbed complexes are electroactive if the adsorption sites are clay edges. Interlayer adsorbed complexes may be electroactive ifa charge shuttle is added or if interlayer swelling is large. Conductivity of the film towards anionic species depends upon the swelling of the clay, which depends on the electrolyte concentration and speciation. The d...

The segmental dynamics of rigid, intermediate, and mobile molecular components in carboxyl terminated polybutadiene (CTPB)/ organo−clay (C18−clay) systems was characterized by fully refocused H NMR FID. In addition, H DQ NMR experiments allowed semiquantitative monitoring of changes in segmental dynamics near the interface. Both methods suggest a critical concentration of 60 wt % CTPB, indicati...