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Vapor-liquid equilibrium measurements have been performed on a set of alcohol/water/salt solutions at atmospheric pressure with a modified Othmer still and a modified Boublik-Benson still. The systems studied are methanol and water with NaCl, NaBr, KCl, and KBr; 1-propanol and water with NaCl, KBr, and NaBr; and 2-propanol with water and NaBr. The measurements are for salt concentrations ranging from infinite dilution to saturation for each water/alcohol solvent mixture

A model for strong aqueous electrolyte solutions based on fluctuation solution theory is introduced. The key thermodynamic quantities in the model—direct correlation function integrals—are evaluated using results from the mean spherical approximation for mixtures of charged hard spheres for the electrostatic part, from hard sphere mixture theory for the excluded volume part and from corrections for infinite dilution properties obtained from experimental data. This model is compared to experimental data on aqueous NaCl and NaBr solutions at room temperature from infinite dilution to 25% salt by weight at pressures of 1 and 250 bar with very encouraging results.

The field‐emission projection microscope has been used to study the field‐emission characteristics of several silicon cold cathodes. The current‐voltage data from nine of these field‐emitter tips were reduced to the more fundamental current density ‐ electric field values after the tip geometry was determined in an electron microscope. Comparison of these results with the available theory by Stratton has shown only limited agreement. Two distinct forms have been found for the relationship between the field‐emitted current I and the applied voltage V when plotted as log10 I vs 104/V. One form is ``nonlinear'' while the other is ``linear,'' and the difference between these appears related to the relative strength of a p layer present on the surface of the silicon field‐emitter. A dependence of the field‐emitted current on the temperature of the silicon tip has been observed.

A 2-year investigation was conducted on eight replicate plots located 30 miles east of Lake Michigan on sand to sandy-clay-loam soil, using 1.8-m-deep lysimeters (4.8 m of volume), consisting of an undisturbed monolith excavated from the soil and containing a bearing (2- to 3-year-old) apple tree each. The aims of this research were to study the leaching rate and migration time of nitrate-N (NO3-N) through the soil profile and to assess the suitability of soil suction tube (SST) water samples to predict the NO3-N leaching rate. The NO3-N concentration in the water collected by the lysimeters ranged from less than 10 mg L (in late summer) to more than 40 mg L (in winter). We calculated that NO3-N lost via leaching in a year amounts up to 141 kg ha, with the most potential for groundwater pollution occurring during the cold and wet season. The application of labeled N ammonium nitrate as fertilizer increased the concentration of NO3-N in the solution collected by SST. Labeled N was found at the bottom of lysimeters 3 months after its application, leaching through the soil profile at a speed of 2 cm day, so that the NO3-N concentration of SST was correlated significantly with NO3-N concentration of lysimeters only when the time of movement was considered. The application of fertilizer did not increase the amount of NO3-N collected by lysimeters, meaning that the NO3-N leaching rate is mostly the result of the breakdown of soil organic matter.