This review focuses on the scope and significance of community college student attrition. It examines the theoretical models that explain and attempt to predict student attrition. It also suggests areas and opportunities for future researchers in this field.

In the following paper, we discuss new methods to trap and manipulate airborne liquid aerosol droplets. We discuss the single gradient force trapping of water aerosols in the 2-14 micron diameter range using both 532 nm and 1064 nm light, as well as the holographic optical trapping of arrays of aerosols. Using this holographic technique, we are able to show controlled aerosol coagulation. We also discuss two techniques based on the radiation pressure trapping of aerosols, namely the dual beam fibre trap and the controlled guiding of aerosols using Bessel beams. We conclude with a discussion of new topics for study based upon these techniques and some possible applications.

A vertically oriented zero order Bessel light beam is shown to create a one-dimensional array of trapped particles over extended (millimeter) distances. The particles take up equilibrium positions over the entire length of the beam and this is a consequence of the interplay between optical scattering and the self-healing properties of the Bessel beam. This work has analogies to recent studies of optically bound matter and allows for the simple creation of one-dimensional particle chains and their subsequent spectroscopic analysis.

We demonstrate a method for the optical trapping of solid aerosol particles. Suspension of silica particles in ethanol allows their delivery to the trapping volume using a commercial medical nebulizer. The ethanol quickly evaporates, leaving the solid particles trapped in air. We use the technique to make comparisons between aerosol and colloid tweezing through power spectra analysis of the particle's positions fluctuations for identical particles trapped in a water or air suspending medium.