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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 271 records · Page 15

Comparative Techno-Economic Analysis of Available Feedstocks for High-Temperature Conversion: Whole Tree Thinnings and Mature Pine Residues

The techno-economic and life cycle implications of utilizing low-cost feedstocks in a high temperature conversion process are of great interest. Here, we investigate the conversion cost impacts of two underutilized feedstocks from the commercial pine industry: 13-year-old whole trees, representing trees removed for the purpose of precommercial thinning, and 23-year-old pine residues, representing a waste stream produced from the deconstruction of mature trees for other purposes. Experimental fast pyrolysis (FP) yields for each feedstock were adjusted to a catalytic fast pyrolysis (CFP) basis and used to estimate process economics by employing published correlations based on rigorous techno-economic modeling. These correlations were used in tandem with results from supply and preprocessing analyses to evaluate the field-to-fuel economics of each feedstock. A small difference in minimum fuel selling price (MFSP) was found between the conversion costs for the two feedstocks, with 23-year-old residues demonstrating a net benefit of $0.27 per gasoline gallon equivalent (GGE) compared to the 13- year-old whole tree thinnings, driven primarily by feedstock supply costs. This suggests that both whole tree thinnings and pine residues may be viable feedstock options for CFP conversion. Life cycle inventories (LCIs) were also generated for each case, enabling a field-to-fuel quantification of the cost and carbon cycle associated with each feedstock.

catalytic fast pyrolysis↗

Technology Maturation of Hot Isostatic Pressing for Nuclear Waste Treatment - 20259

ANSTO is constructing a nuclear waste treatment facility for the immobilization of intermediate-level liquid waste (ILLW) from its nuclear medicine production [1]. This facility shall deploy ANSTO Synroc process technology that converts a liquid waste stream into a durable solid wasteform. Hot Isostatic pressing (HIP) shall be employed to consolidate the dry powdered waste effectively reducing the waste volume and immobilizing the waste components. This paper presents the technology maturation for HIP technology for utilisation in a nuclear waste treatment facility. The HIP has been designed to operate in a remote shielded enclosure, fully integrated with the front-end powder production. Attention has been given in the HIP system design to ensure that it can operate and be maintained to achieve the required production output of the facility. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Combining computational modeling and experimental library screening to affinity-mature VEEV-neutralizing antibody F5

Engineered monoclonal antibodies have proven to be highly effective therapeutics in recent viral outbreaks. However, despite technical advancements, an ability to rapidly adapt or increase antibody affinity and by extension, therapeutic efficacy, has yet to be fully realized. We endeavored to stand-up such a pipeline using molecular modeling combined with experimental library screening to increase the affinity of F5, a monoclonal antibody with potent neutralizing activity against Venezuelan Equine Encephalitis Virus (VEEV), to recombinant VEEV (IAB) E1E2 antigen. We modeled the F5/E1E2 binding interface and generated predictions for mutations to improve binding using a Rosetta-based approach and dTERMen, an informatics approach. The modeling was complicated by the fact that a high-resolution structure of F5 is not available and the H3 loop of F5 exceeds the length for which current modeling approaches can determine a unique structure. A subset of the predicted mutations from both methods were incorporated into a phage display library of scFvs. This library and a library generated by error-prone PCR were screened for binding affinity to the recombinant antigen. Results from the screens identified favorable mutations which were incorporated into 12 human-IgG1 variants. The best variant, containing eight mutations, improved KD from 0.63 nM (parental) to 0.01 nM. While this did not improve neutralization or therapeutic potency of F5 against IAB, it did increase cross-reactivity to other closely related VEEV epizootic and enzootic strains, demonstrating the potential of this method to rapidly adapt existing therapeutics to emerging viral strains.

affinity-maturation↗

Technology Maturation Plan for Catalytic Membrane Reactors Based on Carbon Molecular Sieve Hollow Fiber Membranes for Sustainable and Modular H 2 Production

The overarching objective of the proposed project was to demonstrate a process-intensified approach to economically viable, modular H 2 production from waste biomass using catalytic membrane reactors (CMRs) based on carbon molecular sieve (CMS) hollow-fiber membranes. Specifically, the CMRs were developed to selectively remove H 2 during the high-temperature water-gas shift (WGS) reaction to circumvent thermodynamic limitations on converting CO to CO 2 and H 2 . To this end, our core technical activities were to (1) develop high-performance CMRs based on thermally stable, processible polymer-derived CMS membranes and (2) design and prepare new multicomponent CO 2 -tolerant nano-catalysts using a unique flame-based aerosol process for WGS reaction.

08 HYDROGEN↗

TESS Hunt for Young and Maturing Exoplanets (THYME). V. A Sub-Neptune Transiting a Young Star in a Newly Discovered 250 Myr Association

The detection and characterization of young planetary systems offer a direct path to study the processes that shape planet evolution. We report on the discovery of a sub-Neptune-sized planet orbiting the young star HD 110082 (TOI-1098). Transit events we initially detected during TESS Cycle 1 are validated with time-series photometry from Spitzer. High-contrast imaging and high-resolution, optical spectra are also obtained to characterize the stellar host and confirm the planetary nature of the transits. The host star is a late-F dwarf (M⁎ = 1.2Mꙩ) with a low-mass, M dwarf binary companion (M⁎ = 0.26Mꙩ) separated by nearly one arcminute (∼6200 au). Based on its rapid rotation and Lithium absorption, HD 110082 is young, but is not a member of any known group of young stars (despite proximity to the Octans association). To measure the age of the system, we search for coeval, phase-space neighbors and compile a sample of candidate siblings to compare with the empirical sequences of young clusters and to apply quantitative age-dating techniques. In doing so, we find that HD 110082 resides in a new young stellar association we designate MELANGE-1, with an age of 250(+50, -70) Myr. Jointly modeling the TESS and Spitzer light curves, we measure a planetary orbital period of 10.1827 days and radius of R(p) = 3.2 ± 0.1Rꚛ. HD 110082 b’s radius falls in the largest 12% of field-age systems with similar host-star mass and orbital period. This finding supports previous studies indicating that young planets have larger radii than their field-age counterparts.

TESS↗

Refining the Approach to Process Flowsheet Development and Maturation at Hanford - 20049

Rigorous process flowsheet management strategies form the basis of an enduring approach to refining the River Protection Project Integrated Process Flowsheet. Incorporation of lessons learned, recognizing upstream and downstream impacts and understanding barriers to implementation of process flowsheets from the outset of the decision-making process will help future revisions to the River Protection Project Integrated Process Flowsheet be more robust, technically defensible, cost effective, and time efficient, ultimately leading to an improved environmental stewardship of the Hanford site. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Tank Side Cesium Removal System Project and Technology Maturation Program - 20101

Washington River Protection Solutions (WRPS) is the Tank Operating Contractor (TOC) for the U.S. Department of Energy-Office of River Protection (DOE-ORP) on the Hanford Site. The Hanford Site stores an estimated 56 million gallons of mixed radioactive and chemically hazardous waste in large underground tanks. WRPS is in the process of designing the Tank Side Cesium Removal (TSCR) system to produce a Low Activity Waste (LAW) feed from existing mixed Hanford tank waste. The LAW will be transferred to the Waste Treatment and Immobilization Plant (WTP) LAW Vitrification Facility, where it will be immobilized in a durable glass waste form for disposal. The TSCR Project demonstrates a tank-side treatment system for providing feed to the WTP LAW Vitrification Facility. This system removes undissolved solids and cesium from tank waste supernatant using non-elutable ion exchange media to meet the applicable waste acceptance criteria for the WTP. In support of the project, technology testing has been performed to answer design questions and reduce risk. The project scope and technology testing approach are presented. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Coping with cold: Sorghum cold stress from germination to maturity

Abstract Sorghum [ Sorghum bicolor (L.) Moench] is an important crop that is highly drought tolerant but susceptible to low temperatures. Many studies have begun to explore the genetic basis of variation in chilling sensitivity in the sorghum germplasm in an effort to improve sorghum's chilling tolerance. However, differences in genetic maps and updates to the sorghum reference genome have made comparing studies of chilling in sorghum challenging. Here, we review the current state of research on chilling tolerance and susceptibility in sorghum during germination and emergence, vegetative growth, and reproduction and harvest stages. Using the most recent sorghum reference genome (v3.1), we have standardized the locations of quantitative trait loci and marker‐trait associations for chilling tolerance traits across the literature. This revealed substantial overlap between quantitative trait loci/marker‐trait associations identified for similar traits across studies of different sorghum populations. Chromosomes 2, 3, and 6 contained particularly concentrated regions of markers associated with chilling tolerance traits. Although many studies have uncovered genetic variation for chilling responses in the sorghum germplasm, follow‐up studies are needed to confirm and characterize the molecular mechanisms responsible for variation in chilling tolerance in sorghum. We discuss potential molecular mechanisms for cold stress tolerance based on agreements between studies and address the challenges and opportunities for increasing chilling tolerance in sorghum and other next‐generation crops.

59 BASIC BIOLOGICAL SCIENCES↗