We were able to predict acid concentration to {plus minus}0.08M HNO{sub 3}. In the presence of Al{sup 3} interference, the prediction dropped to {plus minus}0.29 mols/liter over the range 0 to 9M HNO{sub 3}. Temperature affects the prediction of acid adversely and would have to be modelled out or the sample cell thermostated prior to using this method. 10 refs, 12 figs.(DLC)

The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

This report discusses: The description of the GANG Project and results for prior research; the center for geometry, analysis, numerics and graphics; description of GANG Laboratory; software development at GANG; and mathematical and scientific research activities.

Newsletter focusing on pecan disease and pest control in Texas, including prevention, identification, treatment, and educational opportunities.