Plant Metabolic Engineering is an emerging field that integrates a diverse range of disciplines including plant genetics, genomics, biochemistry, chemistry and cell biology. The Gordon-Kenan Graduate Research Seminar (GRS) in Plant Metabolic Engineering was initiated to provide a unique opportunity for future researcher leaders to present their work in this field. It also creates an environment allowing for peer-review and critical assessment of work without the intimidation usually associated with the presence of senior investigators. The GRS immediately precedes the Plant Metabolic Engineering Gordon Research Conference and will be for and by graduate students and post-docs, with the assistance of the organizers listed.

We report on the evaluation of the performance of two recently developed scintillator materials, LaCl{sub 3}:Ce and LaBr{sub 3}:Ce, at the task of gamma ray spectroscopy. Their performance is compared to a standard scintillator used for gamma ray spectroscopy--a 25 mm diameter 25 mm tall cylinder of NaI:Tl. We measure the pulse height, energy resolution, and full-energy efficiency of production LaBr{sub 3}:Ce and LaCl{sub 3}:Ce scintillation crystals of different sizes and geometries for a variety of gamma-ray energies. Using production rather than specially selected crystals will establish whether immediate large-scale use is feasible. The crystal is excited by gamma rays from one of six isotopic sources ({sup 125}I, {sup 241}Am, {sup 57}Co, {sup 22}Na, {sup 137}Cs, and {sup 60}Co) placed 15 cm away from the scintillator. Our measurements show that both LaCl{sub 3} and LaBr{sub 3} outperform NaI:Tl in almost all cases. They outperform NaI:Tl at all energies for the photopeak fraction and counting rate measurements, and for energy resolution at higher energies (above 200 keV for LaCl{sub 3} and 75 keV for LaBr{sub 3}). The performance of production crystals is excellent and these scintillators should be considered for immediate use in systems where stopping power and energy resolution are …

Uncertainty built into conceptual groundwater flow and transport models and associated parametric uncertainty should be appropriately included when such models are used to develop detection monitoring networks for contaminated sites. We compare alternative approaches of propagating such uncertainty from the flow and transport model into the network design. The focus is on detection monitoring networks where the primary objective is to intercept the contaminant before it reaches a boundary of interest (e.g., compliance boundary). Different uncertainty propagation approaches identify different well locations and different well combinations (networks) as having the highest detection efficiency. It is thus recommended that multiple uncertainty propagation approaches are considered. If several approaches yield consistent results in terms of identifying the best performing candidate wells and the best performing well network for detecting a contaminant plume, this would provide confidence in the suitability of the selected well locations.

We have previously evaluated the ductility behaviors of U-6Nb and pure Ta. One important observation was that both alloys have very stable necking ductility independent of test conditions. In contrast, uniform ductility varied significantly depending upon strain rates and temperatures. In general, higher strain rate and lower temperature reduce the uniform ductility. Using literature data, we have developed two dynamic ductility models to predict the ductility behaviors of pure-Ta and water-quenched U-6Nb respectively under extreme conditions. In this study we further evaluate the aging effect on U-6Nb and the W-addition effect on Ta. For U-6Nb, the objective is to determine whether or not the ductility degradation by low-temperature aging mostly measured in quasi-static condition can still be observed under dynamic loading (high strain rate) condition. For Ta-W alloys, the focus is to identify the key control parameter so that the optimal condition of high-strength/high-ductility of Ta-10W can be achieved for certain defense-related applications.

Rainier Mesa (RM) is a tuffaceous, high-elevation plateau on the Nevada Test Site (NTS) that has been subjected to numerous nuclear tests between 1957 and 1992. Unlike other tests on the NTS located within or just above the saturated zone, tests at the RM T-tunnel complex were conducted within a variably saturated sequence of bedded and non-welded vitric and zeolitized tuff units, located approximately 500 m above the regional groundwater flow system. The low permeability and high porosity of the underlying zeolitized tuff units suggest the downward transport of radionuclides released from these tests are minimal through the tuff matrix. However, numerous faults observed to discharge water into tunnel drifts may serve as preferential pathways for radionuclide migration. Data collected from tunnel drifts indicate that faulting within the zeolitized tuff units is sparse with fractal clustering, and that connectivity between adjacent fault clusters is often weak to non-existent. The sparse fault density at RM, in conjunction with the extreme variability in the spatial distribution of faults, poses challenges not readily addressed by existing upscaling methods that upscale fracture properties as equivalent grid tensors. The unique fault statistics at RM has led to the development of a fracture continuum method designed …

None

Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around large shrubs and are common features in deserts in the southwestern United States. Believed to be an important factor in their formation, the shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, {sup 241}Am, and U in plant mounds at safety test sites. The NAEG studies found concentrations of these contaminants to be greater in shrub mounds than in the surrounding areas of desert pavement. For example, at Project 57 on the NTTR, it was estimated that 15 percent of the radionuclide inventory of the site was associated with shrub mounds, which accounted for 17 percent of the surface area of the site, a ratio of inventory to area of 0.85. At Clean Slate III at the …

For Pt, the best single-element catalyst for many reactions, the question of content and loading is exceedingly important because of its price and availability. Using platinum as a fuel-cell catalyst in automotive applications will cause an unquantifiable increase in the demand for this metal. This big obstacle for using fuel cells in electric cars must be solved by decreasing the content of Pt, which is a great challenge of electrocatalysis Over the last several years we inaugurated a new class of electrocatalysts for the oxygen reduction reaction (ORR) based on a monolayer of Pt deposited on metal or alloy carbon-supported nanoparticles. The possibility of decreasing the Pt content in the ORR catalysts down to a monolayer level has a considerable importance because this reaction requires high loadings due to its slow kinetics. The Pt-monolayer approach has several unique features and some of them are: high Pt utilization, enhanced (or decreased) activity, enhanced stability, and direct activity correlations. The synthesis of Pt monolayer (ML) electrocatalysts was facilitated by our new synthesis method which allowed us to deposit a monolayer of Pt on various metals, or alloy nanoparticles [1, 2] for the cathode electrocatalyst. In this synthesis approach Pt is laid down …

Crystals of slightly soluble materials should be subject of relatively weak attachment/detachment fluctuations on their faces so that steps on that faces have low kink density. These steps are parallel to the most close packed lattice rows and form polygons on a crystal surface. The process responsible for implementation of the classical Gibbs-Thomson law (GTL) for the polygonal step (in two dimensions, 2D) is kink exchange between the step corners. For the 3D crystallites, this mechanism includes step exchange. If these mechanisms do not operate because of slow fluctuations the GTL is not applicable. Physics of these processes and conditions for the GTL applicability are discussed on a simple qualitative level.

Thulium(III) oxide (Tm{sub 2}O{sub 3}) targets prepared by the polymer-assisted deposition (PAD) method were irradiated by heavy-ion beams to test the method's feasibility for nuclear science applications. Targets were prepared on silicon nitride backings (thickness of 1000 nm, 344 {micro}g/cm{sup 2}) and were irradiated with an {sup 40}Ar beam at laboratory frame energy of {approx}210 MeV (50 particle nA). The root mean squared (RMS) roughness prior to irradiation is 1.1 nm for a {approx}250 nm ({approx}220 {micro}g/cm{sup 2}) Tm{sub 2}O{sub 3} target, and an RMS roughness of 2.0 nm after irradiation was measured by atomic force microscopy (AFM). Scanning electron microscopy of the irradiated target reveals no significant differences in surface homogeneity when compared to imaging prior to irradiation. Target flaking was not observed from monitoring Rutherford scattered particles as a function of time.

A new field facility was used to study CO2 migrationprocesses and test techniques to detect and quantify potential CO2leakage from geologic storage sites. For 10 days starting 9 July 2007,and for seven days starting 5 August 2007, 0.1 and 0.3 t CO2 d-1,respectively, were released from a ~;100-m long, sub-water table (~;2.5-mdepth) horizontal well. The spatio-temporal evolution of leakage wasmapped through repeated grid measurements of soil CO2 flux (FCO2). Thesurface leakage onset, approach to steady state, and post-release declinematched model predictions closely. Modeling suggested that minimal CO2was taken up by groundwater through dissolution, and CO2 spread out ontop of the water table. FCO2 spatial patterns were related to well designand soil physical properties. Estimates of total CO2 discharge along withsoil respiration and leakage discharge highlight the influence ofbackground CO2 flux variations on detection of CO2 leakagesignals.

This article examines the future role of energy efficiency as a resource in the Western United States and Canada, as envisioned in the most recent resource plans issued by 16 utilities, representing about 60percent of the region's load. Utility and third-party administered energy efficiency programs proposed by 15 utilities over a ten-year horizon would save almost 19,000 GWh annually, about 5.2percent of forecast load. There are clear regional trends in the aggressiveness of proposed energy savings. California's investor-owned utilities (IOUs) had the most aggressive savings targets, followed by IOUs in the Pacific Northwest, and the lowest savings were proposed by utilities in Inland West states and by two public utilities on the West coast. The adoption of multiple, aggressive policies targeting energy efficiency and climate change appear to produce sizeable energy efficiency commitments. Certain specific policies, such as mandated energy savings goals for California's IOUs and energy efficiency provisions in Nevada's Renewable Portfolio Standard had a direct impact on the level of energy savings included in the resource plans. Other policies, such as revenue decoupling and shareholder incentives, and voluntary or legislatively mandated greenhouse gas emission reduction policies, may have also impacted utilities' energy efficiency commitments, though the effects of …

The authors have developed a new target platform to study propagation and backscatter of a frequency-doubled (2{omega}) laser beam through large-scale length plasmas at ignition-design densities, intensities and temperatures above 3 keV. The plasma is created by heating a gas filled hohlraum target with 37 heater beams that deliver a total energy of up to 15 kJ in a 1 ns square pulse. They measure a factor of two higher temperatures than in open geometry gasbag targets investigated earlier. This new temperature regime with a measured beam transmission of up to 80% suggests we can expect good laser coupling into ignition hohlraums at the National Ignition Facility (NIF) using 2{omega} light.

I discuss the ridge phenomena observed in heavy ion collisions at RHIC. I argue that the ridge may be due to flux tubes formed from the Color Glass Condensate in the early Glasma phase of matter produced in such collisions.

Storage of large amounts of carbon dioxide (CO{sub 2}) in deep geological formations for greenhouse gas mitigation is gaining momentum and moving from its conceptual and testing stages towards widespread application. In this work we explore various optimization strategies for characterizing surface leakage (seepage) using near-surface measurement approaches such as accumulation chambers and eddy covariance towers. Seepage characterization objectives and limitations need to be defined carefully from the outset especially in light of large natural background variations that can mask seepage. The cost and sensitivity of seepage detection are related to four critical length scales pertaining to the size of the: (1) region that needs to be monitored; (2) footprint of the measurement approach, and (3) main seepage zone; and (4) region in which concentrations or fluxes are influenced by seepage. Seepage characterization objectives may include one or all of the tasks of detecting, locating, and quantifying seepage. Each of these tasks has its own optimal strategy. Detecting and locating seepage in a region in which there is no expected or preferred location for seepage nor existing evidence for seepage requires monitoring on a fixed grid, e.g., using eddy covariance towers. The fixed-grid approaches needed to detect seepage are expected …

A 55 gallon wastewater drum lid was found to be bulged during storage in a remote area. Drum samples were obtained for analysis. The interior surface of these samples revealed blistering and holes in the epoxy phenolic drum liner and corrosion of the carbon steel drum. It is suspected that osmotic pressure drove permeation of the water through the epoxy phenolic coating which was weakened from exposure to low pH water. The coating failed at locations throughout the drum interior. Subsequent corrosion of the carbon steel released hydrogen which pressurized the drum causing deformation of the drum lid. Additional samples from other wastewater drums on the same pallet were also evaluated and limited corrosion was visible on the interior surfaces. It is suspected that, with time, the corrosion would have advanced to cause pressurization of these sealed drums.

None

PVODE is a high-performance ordinary differential equation solver for the types of initial value problems (IVPs) that arise in large-scale computational simulations. often, one wants to compute sensitivities with respect to certain parameters in the IVP. They discuss the use of automatic differentiation (AD) to compute these sensitivities in the context of PVODE. Results on a simple test problem indicate that the use of AD-generated derivative code can reduce the time to solution over finite difference approximations.

Poly(N-vinylpyrrolidone) (PVP) capped platinum and rhodium nanoparticles (7-12 nm) have been studied with UV-VIS, FTIR and Raman spectroscopy. The absorption bands in the region 190-900 nm are shown to be sensitive to the electronic structure of surface Rh and Pt atoms as well as to the aggregation of the nanoparticles. In-situ FTIR-DRIFT spectroscopy of the thermal decay of PVP stabilized Rh and Pt nanoparticles in H{sub 2} and O{sub 2} atmospheres in temperatures ranging from 30 C-350 C reveal that decomposition of PVP above 200 C, PVP transforms into a 'polyamidpolyene' - like material that is in turn converted into a thin layer of amorphous carbon above 300 C. Adsorbed carbon monoxide was used as a probing molecule to monitor changes of electronic structure of surface Rh and Pt atoms and accessible surface area. The behavior of surface Rh and Pt atoms with ligated CO and amide groups of pyrrolidones resemble that of surface coordination compounds.

The National Compact Stellarator Experiment's (NCSX) modular coils presented a number of engineering and manufacturing challenges due to their complex shapes, requirements for high dimensional accuracy and high current density requirements due to space constraints. Being the first of their kind, these coils required the implementation of many new manufacturing and measuring techniques and procedures. This was the first time that these manufacturing techniques and methods were applied in the production of coils at the laboratory. This resulted in a steep learning curve for the first several coils. Through the effective use of procedures, tooling modifications, involvement and ownership by the manufacturing workforce, and an emphasis on safety, the assembly team was able to reduce the manufacturing times and improve upon the manufacturing methods. This paper will discuss the learning curve and steps that were taken to improve the manufacturing efficiency and reduce the manufacturing times for the modular coils without forfeiting quality.

The deposition of films under normal and off-normal angle of incidence has been investigated to show the relevance of non-sticking of and self-sputtering by energetic ions, leading to the formation of neutral atoms. The flow of energetic ions was obtained using a filtered cathodic arc system in high vacuum and therefore the ion flux had a broad energy distribution of typically 50-100 eV per ion. The range of materials included Cu, Ag, Au, Ti, and Ni. Consistent with molecular dynamics simulations published in the literature, the experiments show, for all materials, that the combined effects of non-sticking and self-sputtering are very significant, especially for large off-normal angles. Modest heating and intentional introduction of oxygen background affect the results.

None

CO oxidation is one of the most studied heterogeneous reactions, being scientifically and industrially important, particularly for removal of CO from exhaust streams and preferential oxidation for hydrogen purification in fuel cell applications. The precious metals Ru, Rh, Pd, Pt, and Au are most commonly used for this reaction because of their high activity and stability. Despite the wealth of experimental and theoretical data, it remains unclear what is the active surface for CO oxidation under catalytic conditions for these metals. In this communication, we utilize in situ synchrotron ambient pressure X-ray photoelectron spectroscopy (APXPS) to monitor the oxidation state at the surface of Rh nanoparticles during CO oxidation and demonstrate that the active catalyst is a surface oxide, the formation of which is dependent on particle size. The amount of oxide formed and the reaction rate both increase with decreasing particle size.

There are two major science programs at the Relativistic Heavy Ion Collider (RHIC). These are the heavy ion program, which collides beams of fully stripped ions, and the polarized proton program. A wide variety of stripper foils and carbon targets are used throughout the RHIC accelerator chain to facilitate these collisions. Each stripper and target has unique properties and functions. Those characteristics will be discussed, as well as recent efforts to improve their performance.