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The Virtual Museum of Minerals and Molecules (VMMM) is a web-based resource presenting interactive, 3-D, research-grade molecular models of more than 150 minerals and molecules of interest to chemical, earth, plant, and environmental sciences. User interactivity with the 3-D display allows models to be rotated, zoomed, and specific regions of interest to be highlighted. The VMMM has been online since 1998 and currently serves 100,000 to 250,000 unique visitors annually from two mirror sites. In concept, it is a blend of a static bricks-and-mortar physical museum with wings, galleries, and displays with dynamic 3-D first-person video games. This museum is virtual not only in the sense that it exists in electronic format but also because the molecular size of the objects makes them colorless and imperceptibly small. To date, molecular visualization has been enabled in browsers using a proprietary third-party plug-in; compatibility with diverse platforms and browsers has been reduced over past years and recourse to open-source, molecular visualization Java applets may be required to avoid technological obsolescence. (Contains 3 figures.)

Energy generation from biomass is an environmentally sound alternative to other energy producing technologies. Pilot studies have indicated that alfalfa (Medicago sativa L.) is a suitable feedstock for energy generation via the gasification process. The resulting ash is a potential liming agent and a source of plant nutrients. A growth chamber study was conducted with three soils to evaluate the potential use of this ash as a soil amendment. Corn (Zea mays L.) received 13 treatments: control, K and/or P fertilizer, seven ash rates (0.6 to 14.6 g ash [kg.sup.-1] soil), and one ash rate with K or P fertilizer. Soil pH increased with ash application on all soils. Ash application increased ammonium acetate-exchangeable K, Ca, and Mg, and Olsen P in soil and decreased DTPA-extractable soil Fe, Mn, Ni, and Pb. Averaged across the three soils, slopes of the cations recovered in plant and soil vs. cations applied in the ash were 0.48, 0.21, and 0.22 of total ash K, Ca, and Mg, respectively ([r.sup.2] > 0.97). Ash significantly increased plant K and Mo, and decreased Mg, Mn, and Zn concentration. Tissue P concentrations were not affected by ash, but increased with P fertilizer. Phosphorus fertilizer increased plant dry mass (DM), but K fertilizer did not, thus K did not limit yield. Alfalfa stem gasification ash is a potential liming agent, a source of K, and would not lead to excessive accumulation of trace elements in soil or plants when applied at rates based on lime or K need.

Dyes are often used as tracers of water and solute flow in soil. However, there has been little published research on the effects of flow velocity on the relative movement of dye and wetting fronts. Recently, the FD&C Blue no. 1 dye has been used as a tracer of preferential water flow paths in soils, and has attractive properties suggesting it will be used increasingly in the future. The objective of this study was to characterize the effects of flow velocity on the adsorption characteristics of the FD&C Blue no. 1. We performed a series of laboratory experiments on the characterization of the equilibrium adsorption isotherm as well as the effect of flow velocity on adsorption characteristics of the FD&C Blue no. I in three horizons of Verndale sandy loam (coarse-loamy over sandy, mixed, frigid Udic Argiboroll). Batch equilibration (24 h) measurements resulted in linearized Freundlich distribution coefficients ([K.sub.d]) of 4.33, 23.95, and 4.59 L [kg.sup.-1] for the Ap, Bt, and C horizons, respectively. Neither organic C nor clay content differences accounted for the variation between horizons. Leaching experiments with a 1 g [L.sup.-1] dye solution and repacked soil columns containing either Ap, Bt, or C horizon material showed that the dye was retarded relative to the wetting front, and that the extent of retardation was inversely related to the time period during which dye solution was applied. Therefore, this dye (and perhaps others) should not be used to make inferences about the movement of water or other solutes until the effect of the application rate is evaluated for the flow conditions in the system(s) of interest.

Mercury contamination in aquatic and wildlife environments was found to be caused by the deposition of human-related emissions and fish product consumption. It was also established that biological aggregation of mercury is triggered by chemical reactions involving trace amounts of mercury in the atmosphere and in bodies of water. Contrary to popular beliefs, the application of diagenic processes is ineffectual in evaluating the causes and determining the sources of mercury contamination.

A study compared three techniques of identifying the degree of excess salt removal during alcohol washing of clays. The three techniques were the AgNO3-Cl test, the assessment of electrical conductivity and the detection of elemental concentrations. Significant amounts of excess Ca and K (around 5 to 10% of CEC) persisted in the clays when the AgNO3-Cl test was first negative. The results confirm the speed and dependability of electrical conductivity as a technique of identifying the completion of excess salt removal.

The distribution of mercury (Hg) within one region can vary considerably rather than necessarily being uniform as is usually thought. Forest floor and soil samples from Minnesota, Wisconsin and Michigan correlated high levels of Hg in the environment with proximity to sources of anthropogenic pollution such as industry. Variations in wet sulfate deposition concomitant to changes in Hg level indicate that the regional differences in Hg are due to human-caused particulate pollution.