Stimulated by an acetate-amendment field experiment conducted in 2007, anaerobic microbial populations in the aquifer at the Rifle Integrated Field Research Challenge site in Colorado reduced mobile U(VI) to insoluble U(IV). During this experiment, planktonic biomass was sampled at various time points to quantitatively evaluate proteomes. In 2008, an acetate-amended field experiment was again conducted in a similar manner to the 2007 experiment. As there was no comprehensive metagenome sequence available for use in proteomics analysis, we systematically evaluated 12 different organism genome sequences to generate sets of aggregate genomes, or “pseudo-metagenomes”, for supplying relative quantitative peptide and protein identifications. Proteomics results support previous observations of the dominance of Geobacteraceae during biostimulation using acetate as sole electron donor, and revealed a shift from an early stage of iron reduction to a late stage of iron reduction. Additionally, a shift from iron reduction to sulfate reduction was indicated by changes in the contribution of proteome information contributed by different organism genome sequences within the aggregate set. In addition, the comparison of proteome measurements made between the 2007 field experiment and 2008 field experiment revealed differences in proteome profiles. These differences may be the result of alterations in abundance and population structure …

Electrofuels Project: MIT is using solar-derived hydrogen and common soil bacteria called Ralstonia eutropha to turn carbon dioxide (CO2) directly into biofuel. This bacteria already has the natural ability to use hydrogen and CO2 for growth. MIT is engineering the bacteria to use hydrogen to convert CO2 directly into liquid transportation fuels. Hydrogen is a flammable gas, so the MIT team is building an innovative reactor system that will safely house the bacteria and gas mixture during the fuel-creation process. The system will pump in precise mixtures of hydrogen, oxygen, and CO2, and the online fuel-recovery system will continuously capture and remove the biofuel product.

Electrofuels Project: MIT is using carbon dioxide (CO2) and hydrogen generated from electricity to produce natural oils that can be upgraded to hydrocarbon fuels. MIT has designed a 2-stage biofuel production system. In the first stage, hydrogen and CO2 are fed to a microorganism capable of converting these feedstocks to a 2-carbon compound called acetate. In the second stage, acetate is delivered to a different microorganism that can use the acetate to grow and produce oil. The oil can be removed from the reactor tank and chemically converted to various hydrocarbons. The electricity for the process could be supplied from novel means currently in development, or more proven methods such as the combustion of municipal waste, which would also generate the required CO2 and enhance the overall efficiency of MIT’s biofuel-production system.

How will the United States satisfy energy demand in a tightening global energy marketplace while, at the same time, reducing greenhouse gas emissions? Exascale computing -- expected to be available within the next eight to ten years ? may play a crucial role in answering that question by enabling a paradigm shift from test-based to science-based design and engineering. Computational modeling of complete power generation systems and engines, based on scientific first principles, will accelerate the improvement of existing energy technologies and the development of new transformational technologies by pre-selecting the designs most likely to be successful for experimental validation, rather than relying on trial and error. The predictive understanding of complex engineered systems made possible by computational modeling will also reduce the construction and operations costs, optimize performance, and improve safety. Exascale computing will make possible fundamentally new approaches to quantifying the uncertainty of safety and performance engineering. This report discusses potential contributions of exa-scale modeling in four areas of energy production and distribution: nuclear power, combustion, the electrical grid, and renewable sources of energy, which include hydrogen fuel, bioenergy conversion, photovoltaic solar energy, and wind turbines. Examples of current research are taken from projects funded by the U.S. …

Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________

Photosynthetic assimilation of atmospheric carbon dioxide by land plants offers the underpinnings for terrestrial carbon (C) sequestration. A proportion of the C captured in plant biomass is partitioned to roots, where it enters the pools of soil organic C and soil inorganic C and can be sequestered for millennia. Bioenergy crops serve the dual role of providing biofuel that offsets fossil-fuel greenhouse gas (GHG) emissions and sequestering C in the soil through extensive root systems. Carbon captured in plant biomass can also contribute to C sequestration through the deliberate addition of biochar to soil, wood burial, or the use of durable plant products. Increasing our understanding of plant, microbial, and soil biology, and harnessing the benefits of traditional genetics and genetic engineering, will help us fully realize the GHG mitigation potential of phytosequestration.

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Sulfate-reducing bacteria have been extensively studied for their potential in heavy-metal bioremediation. However, the occurrence of elevated nitrate in contaminated environments has been shown to inhibit sulfate reduction activity. Although the inhibition has been suggested to result from the competition with nitrate-reducing bacteria, the possibility of direct inhibition of sulfate reducers by elevated nitrate needs to be explored. Using Desulfovibrio vulgaris as a model sulfate-reducing bacterium, functional genomics analysis reveals that osmotic stress contributed to growth inhibition by nitrate as shown by the upregulation of the glycine/betaine transporter genes and the relief of nitrate inhibition by osmoprotectants. The observation that significant growth inhibition was effected by 70 mM NaNO{sub 3} but not by 70 mM NaCl suggests the presence of inhibitory mechanisms in addition to osmotic stress. The differential expression of genes characteristic of nitrite stress responses, such as the hybrid cluster protein gene, under nitrate stress condition further indicates that nitrate stress response by D. vulgaris was linked to components of both osmotic and nitrite stress responses. The involvement of the oxidative stress response pathway, however, might be the result of a more general stress response. Given the low similarities between the response profiles to nitrate and other stresses, …