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Title: Closeout of award DE-FG02-00ER41135


Close out report for DE-FG02-00ER41135

  1. University of Pittsburgh
Publication Date:
Research Org.:
University of Pittsburgh
Sponsoring Org.:
USDOE Office of Science (SC) Nuclear Physics
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Country of Publication:
United States

Citation Formats

Swanson, Eric S. Closeout of award DE-FG02-00ER41135. United States: N. p., 2015. Web. doi:10.2172/1171389.
Swanson, Eric S. Closeout of award DE-FG02-00ER41135. United States. doi:10.2172/1171389.
Swanson, Eric S. 2015. "Closeout of award DE-FG02-00ER41135". United States. doi:10.2172/1171389.
title = {Closeout of award DE-FG02-00ER41135},
author = {Swanson, Eric S.},
abstractNote = {Close out report for DE-FG02-00ER41135},
doi = {10.2172/1171389},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2015,
month = 2

Technical Report:

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  • This entire project was conducted between 1995 and 1999, during which two postdocs and numerous undergraduate students received training in research. Furthermore, the funds from this grant contributed either totally or partially to the publication of 14 refereed journal articles. The focus of this research was to investigate plant nitrogen budget under elevated CO{sub 2} concentration. Of particular interest were the following: (1) Does elevated CO{sub 2} increase root carbohydrate availability? (2) Does such an enhancement increase kinetics of root nitrogen acquisition? (3) Does the effect on kinetics differ between NH{sub 4}{sup +} and NO{sub 3}{sup -}? (4) If theremore » are interspecific differences in (1)-(3), could those variations lead to changes in community composition? This report shows that, although root carbohydrate availability often increases in response to elevated CO{sub 2}, such an increase is neither necessary nor directly related to changes in root N uptake kinetics . The data also show that, depending on species, the effects of elevated CO{sub 2} on root nitrogen uptake kinetics ranges from down regulation to no changes to up regulation. Furthermore, the effects on NH{sub 4}{sup +} are not always similar to the effects on NO{sub 3}{sup -}. Perhaps the most critical finding is the fact that in many instances a change in root N uptake kinetics alone does not provide a reliable prediction of plant N acquisition in response to elevated CO{sub 2}. It is shown that a better examination of whether plant N uptake responds to CO{sub 2} level and whether such a response can be scaled up to community level processes would require integration of knowledge of other root system characteristics. For example, it is well established that mycorrhizal fungi are important regulators of plant N uptake. The data suggest that, while elevated CO{sub 2} affects root N uptake capacity, this effect is highly dependent on the type and level of the mycorrhizal infection. Another root characteristic that significantly affects N uptake and could mask any potential impact of kinetics is root morphology. When all else is equal, increased biomass allocation to roots is the least effective mechanism in adjusting plant N uptake under elevated CO{sub 2}. Finally, plants may be able to reduce their demand for N via increased N use efficiency (NUE). The research conducted here indicates that elevated CO{sub 2} may evoke different responses in NUE depending upon species and that an increased NUE may be one of the most effective mechanisms in optimizing N uptake and growth responses to elevated CO{sub 2}. It is concluded that elevated CO{sub 2} can have a dramatic effect on root N uptake kinetics, but viewed in isolation this observation does not provide a robust assessment of plant N economy under an enriched CO{sub 2} atmosphere. Therefore, future work designed to predict whole-plant N responses to elevated CO{sub 2} must consider other root system adjustment s listed above, collectively.« less
  • As the title of the grant clearly states, this project has explores a unique way that makes use of manmade proteins to turn solar energy into chemical fuels. A major impetus to the work is that there is growing support for the view that two related forces will impact on future livability of Earth. The first is the finite supply of fossil fuels to power the Earth making it prudent to save this resource for the creation of useful chemicals. The second is that burning fossil fuels to generate power releases “greenhouse” gases into the atmosphere. There is mounting evidencemore » that this is a major contribution to the warming trend in the Earth’s atmosphere and biosphere.« less
  • Michigan State University (MSU) activities in support of this grant were made as part of a larger collaboration including Los Alamos National Laboratory, Argonne National Laboratory, and Lawrence Berkeley National Laboratory. The main task of the collaboration was the development of an end-to-end multiparticle beam-dynamics simulation tool for computation of beam losses in the RIA driver linac. As the first part of this task, it was planned to modify PARMTEQ for multicharge-state beam-dynamics simulation in the LEBT and RFQ. The next part of this task was to develop a new multiparticle parallel code to model the superconducting driver linac. Themore » output particle distributions from PARMTEQ could then be used as input for simulations through the superconducting linac, using the new parallel code with different random number seeds. The stripping of heavy ions is proposed for the RIA driver linac to increase acceleration efficiency. MSU developed a complete charge stripping foil model to evaluate the impact of the stripping foil on the beam transverse and longitudinal emittance. The stripping foil model was developed in LANA [1] and included the effects of elastic and inelastic scattering, ionization energy loss, and thickness variation in the stripping foil using the code SRIM [2]. This model was provided to the collaboration for inclusion in the new simulation tools. Benchmarking information in support of the new code development was provided by supplying the collaboration with the MSU driver linac model consisting of input information for LANA and DIMAD [3] The output of simulations using LANA and DIMAD were also provided. As an element of these activities, LANA was modified to provide simulation results with high statistics. The simulation results from the newly developed simulation tools and those of MSU gave statistically equivalent results.« less
  • The final report describes the study aimed at exploring the variable-resolution stretched-grid (SG) approach to decadal regional climate modeling using advanced numerical techniques. The obtained results have shown that variable-resolution SG-GCMs using stretched grids with fine resolution over the area(s) of interest, is a viable established approach to regional climate modeling. The developed SG-GCMs have been extensively used for regional climate experimentation. The SG-GCM simulations are aimed at studying the U.S. regional climate variability with an emphasis on studying anomalous summer climate events, the U.S. droughts and floods.