Introduction: Individual grains and small lithic clasts in thin-sectioned suevitic breccia samples from the International Continental Scientific Drilling Program (ICDP) Bosumtwi impact crater drillcore LB07A were examined petrographically to evaluate the occurrence , abundance, and characteristics of unshocked and shock-metamorphosed quartz. The analyzed samples were taken across a ~42-m-long (...

A series of column experiments was undertaken to explore the influence of colloid input concentration (2, 1, 0.5, and 0.25 times a reference concentration), colloid size (negatively charged 3.2 and 1.0 microm carboxyl latex), and sand grain size (360, 240, and 150 microm quartz sands) on transport and deposition. A similar mass of stable mono-dispersed colloids was added to each column. For a g...

[1] Previous field-scale experimental data and numerical modeling suggest that the dual-domain mass transfer (DDMT) of electrolytic tracers has an observable geoelectrical signature. Here we present controlled laboratory experiments confirming the electrical signature of DDMT and demonstrate the use of time-lapse electrical measurements in conjunction with concentration measurements to estimate...

Transmissible spongiform encephalopathies (TSEs, prion diseases) are a class of fatal neurodegenerative diseases affecting a variety of mammalian species including humans. A misfolded form of the prion protein (PrP(TSE)) is the major, if not sole, component of the infectious agent RecentTSE outbreaks in domesticated and wild animal populations have created the need for safe and effective dispos...

The mechanisms of phosphate (P) mobilized by wheat were studied with the typically efficient or inefficient genotypes grown in a split-pot experiment. The split-pot was composed of two parts, the lower part was a 2-L plastic pot containing two liters of nutrient solution and the upper part was a PCV tube six cm in diameter by eight cm high and with a nylon net bottom. The tube which was fixed o...

This research focuses on the effects of transients in porewater chemistry on colloid mobilization within water-saturated porous media. We develop a model that couples equations for solute transport with those for colloid release and transport. The model accounts for heterogeneity in the interaction energies between deposited colloids and the mineral grains by dividing the immobile-phase colloid...