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Developing three-dimensional (3D) graphene assemblies with properties similar to those individual graphene sheets is a promising strategy for graphene-based electrodes. Typically, the synthesis of 3D graphene assemblies relies on van der Waals forces for holding the graphene sheets together, resulting in bulk properties that do not reflect those reported for individual graphene sheets. Here, we report the use of sol-gel chemistry to introduce chemical bonding between the graphene sheets and control the bulk properties of graphene-based aerogels. Adjusting synthetic parameters allows a wide range of control over surface area, pore volume, and pore size, as well as the nature of the chemical cross-links (sp(2) vs sp(3)). The bulk properties of the graphene-based aerogels represent a significant step toward realizing the properties of individual graphene sheets in a 3D assembly with surface areas approaching the theoretical value of an individual sheet.

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The sorption behavior of Eu(III), Sm(III), Np(V), Pu(V), and Pu(IV) in the presence of calcite and as a function of pH and carbonate alkalinity was measured by batch sorption experiments. Eu(III) and Sm(III) sorption is similar, consistent with their observed aqueous speciation and precipitation behavior. For both rare earth elements, sorption decreases at the highest and lowest measured pHs. This is likely the result of speciation changes both of the calcite surface and the sorber. An increase in the equilibrium CO 2 (g) fugacity results in a shift in the sorption behavior to lower pH, consistent with a predicted aqueous speciation shift. Np(V) and Pu(V) sorption exhibited a strong pH dependence. For Np(V), K d s range from 0 to 217 mL/g suggesting that carbonate aqueous speciation as well as changes in the calcite surface speciation greatly affect Np(V) sorption to the calcite surface. Similar behavior was found for Pu(V). Pu(IV) sorption is also strongly pH dependent. Sorption decreases significantly at high pH as a result of Pu-carbonate complexation in solution. A surface complexation model of Sm(III), Eu(III), Np(V), Pu(V), and Pu(IV) sorption to the calcite surface was developed based on the calcite surface speciation model of Pokrovsky and Schott [1]. Sorption data were fit using one or two surface species for each sorber and could account for the effect of pH and CO 2 (g) fugacity on sorption. A relatively poor model fit to Pu(IV) sorption data at high pH may result from our poor understanding of Pu(IV)-carbonate aqueous speciation. While our surface complexation model may not represent a unique solution to the sorption data, it illustrates that a surface complexation modeling approach may adequately describe the sorption behavior of a number of radionuclides at the calcite surface over a range of solution conditions.

The desert locust Schistocerca gregaria behaviorally thermoregulates in order to try and maintain a favoured "set point" body temperature. Locusts infected with the deuteromycete fungal pathogen Metarhizium anisopliae var acridumchoose a significantly elevated temperature. This "behavioral fever" greatly delays the progress of mycosis. We have confirmed this phenomenon and shown that desert locusts also fever when infected with the bacterial pathogen Serratia marcescens. Elevation in the prefered environmental temperature occurs also upon injection with laminarin and lipopolysaccharide (microbial cell wall components). Since such treatments also stimulate the immune system it would appear that "behavioral fever" is probably a feature of the immune response. The eicosanoid biosynthesis inhibitor dexamethasone prevented laminarin invoked fever. This effect was reversable by arachidonic acid. Therefore in common with the febrile response in mammals behavioral fever in insects may be mediated locally by circulating eicosanoids.