No abstract

No abstract

An analytical model that incorporates effects of light scattering was developed for dual-beam photothermal deflection spectroscopy. Thermal gradients induced by a modulated excitation beam deflect an optical probe beam which was treated as being of finite dimensions. Mechanisms by which thermal gradients produce refractive index gradients are discussed, with an explicit expression for dn/dT being derived. Experimental studies with suspensions of small latex particles in Nd(3+) solutions demonstrated that the model accurately predicts both the shape of the deflection signal and the attenuation of the signal due to light scattering. The absolute magnitude of the observed signal is approximately predicted by theory.

This report covers the investigation of mechanisms for the retardation of U(VI) migration. It describes (1) the measurement of the solubility of UO22+as afunction of pH and equilibration time, (2) the calculation of solubility using solution thermochemical data, (3) the measurement of the sorption of UO22+by silica as a function of pH and supporting electrolyte concentration, and (4) attempts to simulate the uranium sorption isotherms in terms of the U solution thermochemical data, measured properties of the silica and proposed sorption reaction mechanisms.

erators are fed with air ( 31)) that its effect on ozone measurements can be neglected.For these reasons, the sensor here described appears to be well suited for ozone monitoring in general applications of this reagent, such as chemical syntheses or disinfection and preservation procedures. ACKNOWLEDGMENTWe thank S. Sitran of CNR-IPELP (Padova) for skillful experimental assistance.