Two-photon laser-induced fluorescence study of the CO B 1Σ+ (v' = 0) state in a 4850 K plasma plume: Modified molecular constants, evidence of predissociation, and J'-dependent photoionization.

We report the two-photon absorption laser-induced fluorescence rotational spectrum of the CO B 1Σ+ ← X 1Σ+ Hopfield-Birge system (v' = 0, v″ = 0) Q-branch in an ∼4850 K, atmospheric pressure plasma torch plume at thermal equilibrium in both the quenching-dominated (low laser intensity) and photoionization-dominated (high laser intensity) regimes. We provide a detailed analysis of the photophysics in these two regimes using a rate equation approach and propose modeling considerations for them as well. In the experimental spectra, distinct rotational transitions up to J″ = 83 are observed, allowing analysis over a very large range of rotational states.

Production and characterization of drug-loaded toroidal vortices from a novel ocular drug delivery device.

For the last several decades, the predominant method for delivering medicine to the surface of the eye has been the standard multiuse eye dropper. While being the most popular, this method has significant limitations. Recently, an effort has been made to explore the use of a directed toroidal vortex or "smoke ring" aerosol delivery system that may help overcome these limitations and enable delivery of precise amounts of formulation and drug to the ocular surface.

Naphthalene laser-induced fluorescence measurements at low temperature and pressure.

Few studies on naphthalene vapor fluorescence have been conducted at low temperature and pressure conditions. The current study focuses on conducting measurements of naphthalene quenching and absorption cross section in a temperature- and pressure-regulated test cell with 266 nm laser excitation. The test-cell measurements were of the naphthalene-fluorescence lifetime and integrated fluorescence signal over the temperature range of 100 to 525 K and pressure range of 1 to 40 kPa in air.

Evaluation of the USP dissolution test method A for enteric-coated articles by planar laser-induced fluorescence.

The USP drug release standard for delayed-release articles method A was evaluated using planar laser-induced fluorescence (PLIF). Prior authors have suggested that high pH "hot spots" could develop during the buffer medium addition of the method A enteric test. Additionally, previous studies have shown heterogeneous flow patterns and low-shear regions in the USP Apparatus II dissolution vessel, which may result in poor mixing of the buffer and acid media during the pH neutralization step of the method A enteric test.