Publications by authors named "Hal Van Ryswyk"

The reported changes in self-diffusion of small molecules during reactions have been attributed to "boosted mobility". We demonstrate the critical role of changing concentrations of paramagnetic ions on nuclear magnetic resonance (NMR) signal intensities, which led to erroneous measurements of diffusion coefficients. We present simple methods to overcome this problem.

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Bioswales are a type of permeable green infrastructure designed to slow stormwater and clean runoff by sequestering pollutants such as heavy metals. Measurements of dissolved pollutants before and after the bioswale often justify their ability to clean this runoff, but research addressing the physical and chemical sequestration of these pollutants is scarce. Soil samples were taken from an arid bioswale and analyzed for concentrations of aluminum, cobalt, chromium, copper, iron, magnesium, manganese, nickel, lead, vanadium and zinc.

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Two porphyrin-based dyes with carboxylic acid tethers of differing acidity in both protonated and deprotonated forms were examined on ZnO nanotube electrodes. All of the dyes have similar surface coverage, but only the more acidic dye in the acid form injects electrons well; this dye is the only one that corrodes the ZnO. In control experiments on TiO(2) nanoparticle electrodes, both dyes load and inject in protonated and deprotonated forms.

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