A long path dc plasma arc operated in an atmosphere of
argon is described. The arc is easily ignited and operated, and
is inexpensive to use. Samples were introduced into the arc as
solution aerosols. Radially resolved emission measurements are
reported for calcium, copper, and hafnium. The detection limit
for...
Indole-3-carbinol (I3C) is a naturally occurring plant alkaloid, found in significant concentrations in cruciferous vegetables such as broccoli and Brussels sprouts. I3C is an unstable compound that undergoes rapid oligomerization in an acidic environment to form higher order condensation products (I3C-ACPs), such as 3-3'-diindolylmethane (DIM). Both I3C and DIM are...
Atomically-thin graphene sheets have unprecedented characteristics for biosensing applications. These characteristics include mechanical flexibility and strength, optical transparency, electrical sensitivity and biocompatibility. The primary theme of this dissertation is the characterization and application of graphene field-effect transistors (FETs) in biologically-relevant physiological environments.Understanding the interface that forms between an electrolyte and...
Wheat (Triticum aestivum) is a highly valuable crop that makes up a large portion of the world’s food. However, breeding for improved varieties with desirable characteristics can be a challenge. This research examined two different issues wheat breeders deal with throughout the selection process all the way to production of...
A new three-phase argon plasma arc was developed for analytical emission spectroscopy. The power supplied to the plasma arc utilized a simple circuit with three-phase as line voltage stepped down via a transformer to 104Vrms. A three concentric quartz tubing assembly was determined to be the optimum configuration for supplying...
A framework for an empirical parameterization (EP) of heterogeneous nucleation of ice crystals by multiple species of aerosol material in clouds was proposed in a 2008 paper by the authors. The present paper reports improvements to specification of a few of its empirical parameters. These include temperatures for onset of...
Using a graphene field-effect transistor biosensor, we monitored the pH inside a living biofilm
with fast temporal resolution (~ 1 s) over multi-hour time periods. The atomically-thin sensor is
positioned between the biofilm and a supporting silicon oxide surface, providing non-invasive
access to conditions at the base of the biofilm....
Ice concentrations in orographic wave clouds at temperatures between −24° and −29°C were shown to be related to aerosol characteristics in nearby clear air during five research flights over the Rocky Mountains. When clouds with influence from colder temperatures were excluded from the dataset, mean ice nuclei and cloud ice...