Infiltration of highly concentrated solutions into unsaturated sand is suspected to be affected by the liquid-gas interfacial tension between the resident water and that of the infiltrating solution. The wetting of non-porous solid surfaces by liquids is commonly quantified by contact angle measurements. However, it is well known that wettability...
A new technique for determining the amount of opal in deep-sea
sediments of any age is described. Using a normative calculation, a
portion of the analytical silica concentration of sediments is subtracted
as non-biogenic in proportion to the concentration of aluminum in the
sample. The ratio of SiO₂:Al₂O₃ used to...
The literature available on the silica content of herbaceous biomass, and its relative mobility in leaching/extraction systems, includes studies that have employed several different methods for silica quantification. This makes comparison of the data difficult. The objective of this thesis research was to determine the quantitative relationships between the measured...
Dissolved silicic acid (Si(OH)4) and biogenic silica (BSiO2) concentrations were measured on four different cruises in the Southern Ocean along 1700 W from late October 1997 to mid-March 1998. These data were used to construct a vertically integrated Si budget in the surface layer from 58° to 68° S. Throughout...
A label-free, photoluminescence (PL) based biosensor for 2,4,6-trinitrotoluene (TNT) detection was developed by functionalizing diatom biosiilica with a TNT-specific single-chain variable fragment (scFv). The scFv loading was estimated to be 0.040±0.003 (μg scFv/μg biosilica). In saturated concentration, TNT binding to scFvbiosilica quenched about 13% of its PL. Dose response follows...
This thesis presents a study of applications and techniques for molecular dynamics simulations. Three studies are presented that are intended to improve our ability to simulate larger systems more realistically. A comparison study of two- and three-body potential models for liquid and amorphous Si0₂ is presented. The structural, vibrational, and...
There is significant interest in the fabrication of nano- and micro-structured silica with spatially ordered features, which exhibit enhanced optoelectronic properties with application to the next generation of display devices, semiconductors, and sensors. Currents methods of fabrication employ top down processes which use extremes of temperature, pressure, and power. There...