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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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The recent advances and new insights resulting thereof in applying defect engineering to improving the thermoelectric performance and mechanical properties of inorganic materials are reviewed.
Microbial lipid metabolism is an attractive route for producing oleochemicals. The predominant strategy centers on heterologous thioesterases to synthesize desired chain-length fatty acids. To convert acids to oleochemicals (e.g., fatty alcohols, ketones), the narrowed fatty acid pool needs to be reactivated as coenzyme A thioesters at cost of one ATP per reactivation – an expense that could be saved if the acyl-chain was directly transferred from ACP- to CoA-thioester. Here, we demonstrate such an alternative acyl-transferase strategy by heterologous expression of PhaG, an enzyme first identified in Pseudomonads, that transfers 3-hydroxy acyl-chains between acyl-carrier protein and coenzyme A thioester forms for creating polyhydroxyalkanoate monomers. We use it to create a pool of acyl-CoA’s that can be redirected to oleochemical products. Through bioprospecting, mutagenesis, and metabolic engineering, we develop three strains of Escherichia coli capable of producing over 1 g/L of medium-chain free fatty acids, fatty alcohols, and methyl ketones.
Oil sorghum (OS) has been developed by engineering grain (TX430) and sweet (Ramada) genetic backgrounds to accumulate triacylglycerols (TAG) in vegetative tissues as an energy-dense feedstock for sustainable aviation fuel (SAF) and other biofuels. This study evaluated two TX430 OS lines (TxHO-2, TxHO-3) and two Ramada OS lines (RmHO-1, RmHO-2) alongside wild-type (WT) lines in NE and IL over 2 years (2023–2024) to quantify genotype × environment effects on agronomic performance and TAG accumulation. Across four environments, TX430 OS lines showed average TAG concentrations of 15.0 g kg−1 in leaves and 12.8 g kg−1 in stems, approximately 19-fold higher than WT. Ramada OS lines accumulated 26.1 g kg−1 in leaves and 12.3 g kg−1 in stems, approximately 25-fold and 13-fold increases over WT, respectively. OS lines in TX430 exhibited an 18% reduction in biomass (8.4 vs. 9.9 Mg ha−1 for WT), while Ramada OS lines had similar WT biomass (18.3 vs. 19.9 Mg ha−1 for WT). Among TX430 OS lines, TxHO-2 achieved the highest TAG yield (190 kg ha−1), while RmHO-1 led the Ramada lines (335 kg ha−1) due to higher biomass and similar TAG concentration. Enhanced TAG accumulation increased N, P, and K removal in TX430 lines but not in Ramada lines. Structural carbohydrate and ash concentration were unaffected. Overall, results confirm vegetative lipid accumulation as a viable strategy for high-biomass sorghum, supporting its potential as a dual-purpose feedstock for SAF. Future work should focus on minimizing biomass yield penalties and improving nutrient use efficiency in oil sorghum systems.
Engine-integrated secondary injection side-force generation for hydrogen-fueled rocket engine
High lift characteristics of variable-sweep transport model with blended engine-fuselage and engine-mounted horizontal tails
Low-speed characteristics of variable-sweep supersonic transport model with blended engine fuselage and engine-mounted tails
Surveys of engineering school needs in field of biomechanical and human factors engineering education
Computer and engine performance study of jet engine generalized parameter fuel control
Thermodynamic performance test analyses for Apollo spacecraft ascent, descent, and service propulsion system engines to define hypergol engine restart limits
Cold flow and hot firing test details for Apollo spacecraft ascent, descent, and service propulsion system engines to define hypergol engine restart limits
Fluid mechanics and engine dynamics and start-up experiments simulating thermal environment in nuclear light bulb engine
Coupled supersonic inlet-engine control using overboard bypass doors and engine speed to control normal shock position
Validating gas generator method of calculating jet engine thrust, and evaluation of XB-70-1 engine performance at ground static conditions
Engineering methods for predicting temperatures and velocities in vicinity of vertical lift engines of jet V/STOL aircraft operating near ground
Effects of engine inlet disturbances on engine stall performance
Supersonic inlet engine control using engine speed as primary variable for controlling normal shock position
Turbofan engine designs and tests for engine noise reduction
Low pressure turbofan rotor, stator, frame, and exhaust nozzle designs for turbofan engine noise reduction including acoustics and engine tests