Engineering topics

Foster, Justin

Publications and source records attributed to Foster, Justin.

3 records

DOE OSTI2018

Effect of Acyl Activating Enzyme (AAE) 3 on the growth and development of Medicago truncatula

The Acyl-Activating Enzyme (AAE) 3 gene encodes an oxalyl-CoA synthetase that catalyzes the conversion of oxalate to oxalyl-CoA in a CoA and ATP-dependent manner. Although the biochemical activity of AAE3 has been established, its biological role in plant growth and development remains unclear. To advance our understanding of the role of AAE3 in plant growth and development, we report here the characterization of two Medicago truncatula AAE3 (Mtaae3) mutants. Characterization of a Mtaae3 RNAi mutant revealed an accumulation of calcium oxalate crystals and increased seed permeability. These phenotypes were also exhibited in the Arabidopsis aae3 (Ataae3) mutants. Unlike the Ataae3 mutants, the Mtaae3 RNAi mutant did not show a reduction in vegetative growth, decreased seed germination, or increased seed calcium concentration. In an effort to clarify these phenotypic differences, a Mtaae3 Tnt1 mutant was identified and characterized. This Mtaae3 Tnt1 mutant displayed reduced vegetative growth, decreased seed germination, and increased seed calcium concentration as well as an accumulation of calcium oxalate crystals and increased seed permeability as found in Ataae3. Overall, the results presented here show the importance of AAE3 in the growth and development of plants. In addition, this study highlights the ability to separate specific growth and development phenotypes based on the level of AAE3 gene expression.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Fabrication of a glancing-angle-deposited distributed polarization rotator for ultraviolet applications

Glancing-angle–deposited thin films are used to fabricate half-wave plates in a 1-D striped geometry, forming alternating regions of linearly polarized light on a single 100-mm-diam substrate. MgO is selected for fabricating the birefringent films for use in vacuum, based on its formation of isolated columns that avoid potential tensile-stress failure of the porous film. While large-area tests have shown high defect densities for fluences <10 J/cm 2 , small-spot laser-damage testing has shown resistance to fluences up to 30 J/cm 2 (351-nm, 5-ns pulse). Here, an amorphous silica film is investigated to match the optical thickness in the intermediate regions in an effort to fabricate a polarization-control device to reduce focal-point modulation (“beam smoothing”) in high-intensity laser systems. Ongoing efforts to improve the laser-damage threshold and minimize optical losses caused by scatter are essential to realizing a practical device. Scalability of the process to meter-scale substrates is also explored.

47 OTHER INSTRUMENTATION↗

DOE OSTI2012

Case for Open-Source PEV Charge Management Data Framework

The future growth of electrified transportation could be enhanced through interaction with smart grid system architectures. This paper summarizes current literature regarding plug-in electric vehicle - renewables integration and highlights areas of need to implement such integration at a multi-utility scale. Future smart grid implementations hold the key to transferring information and control parameters between distributed and centralized decision agents. The discussion highlights the opportunity to leverage federal investments in grid renovation and electric vehicle introduction to create system-wide value from improved reliability and reduced fossil fuel consumption. An approach to scaling a previously defined 'green signal' methodology for electric vehicles will be detailed across a utility grid balancing region. The research will include a synopsis of the communications opportunities and challenges of coordinating the responses of many resources. The results are expected to show that, with some variation in the charge profiles of individual vehicles, the aggregate set can interface with grid management methods to significantly influence the ability to integrate distributed and centralized renewables to improve environmental quality.

24 POWER TRANSMISSION AND DISTRIBUTION↗