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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Zero-Export Feeder Through Transactive Markets

This presentation summarizes how HELICS was used during a collaborative project with Energy Web Foundation and Exelon Corporation. The primary focus of the research was on designing a transactive energy market to accomplish zero export at the feeder head. The market was tested in a HELICS co-simulation framework and showed significant promise for eliminating back feed at the substation even under high renewable energy penetration levels.

blockchain↗
DOE OSTI2024

Aconitic acid exporter (aexA) increases organic acid production in Aspergillus

Recombinant Aspergillus genetically modified to increase expression of g8846, renamed herein as aconitic acid exporter (aexA), are provided, which in some examples are also genetically inactivated for an endogenous cis-aconitic acid decarboxylase (cadA) gene. Such recombinant Aspergillus produce more aconitic acid as compared to native Aspergillus. Also provided are methods of using such recombinant Aspergillus to increase production of aconitic acid and other organic acids, such as citric acid, itaconic acid, and 3-hydroxypropionic acid (3-HP).

Deng, Shuang↗
DOE OSTI2026

Arctic shipping under global change: A case study of offshore oil exports

We explore impacts of sea ice thinning and evolutions in the energy sector on future use of the Northern Sea Route (NSR) versus the Suez Canal Route (SCR), using a case study of shipping oil extracted from the offshore Russian Arctic to China. We combine an integrated human-Earth system model with a shipping cost model to incorporate impacts on both oil production and shipping costs under internally consistent scenarios. We find that the NSR could become cost-competitive with the SCR as sea ice thickness declines, especially in an RCP8.5 scenario, due to decreasing fuel and icebreaker escort costs. In a global energy evolution scenario consistent with RCP2.6, high emissions costs on the longer SCR may outweigh the costs associated with thicker sea ice on the NSR. Our novel framework provides integrated projections of NSR shipping traffic driven by a specific commodity likely to be shipped through the Arctic.

Arctic↗
DOE OSTI2023

Diminishing marginal effect in estimating the dissolved organic carbon export from a watershed

Dissolved organic carbon (DOC) can be initially moved from soils to inland waters with surface runoff, and then mineralized, buried, or eventually delivered to the coastal ocean. This land-to-ocean phase of the DOC flux must be accounted for to comprehensively understand the global carbon cycle. To estimate the terrestrial-aquatic DOC leaching, calculating the product of the riverine DOC concentration and the corresponding river discharge measured at the watershed outlet is a common method. However, it is challenging to frequently and exactly record riverine DOC concentrations, thus the relationship between DOC concentrations and discharges (C-Q relationship) are established and used to interpolate the time-series of DOC concentrations. We found that the widely used time-dependent and time-independent C-Q regression models are weak in representing their altered relationship when the discharge is extremely high, which was named as diminishing marginal effect. In this study, we evaluated the performance of two C-Q regression models and discussed possible reasons for the diminishing marginal effect. We suggest that repeated and long-term measurements of the DOC concentration are required to adequately analyze their relationships, especially during the early spring and seasons with heavy precipitations.

54 ENVIRONMENTAL SCIENCES↗