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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Development of In-Situ Chlorine Generator for Metal Purification (End of Contract Report)

It has been demonstrated that rare-earth and actinide metals can be purified via conversion to chlorides and heating to volatilize impurities. To this end, BYU has been working towards designing, building, and testing a system that incorporates the chlorine gas generation method into the chloride volatility process. The efforts made towards the project tasks listed in the Statement of Work are addressed in the following sections. Finally, a report on information related to this project that has been published or presented is addressed. By the end of the contract period, small-scale tests using LaCl 3 -CaCl 2 to generate Cl 2 had been conducted, the produced Cl 2 was successfully reacted with Ce foil to create CeCl 3 , initial designs for the large-scale apparatus were completed, and manufacturing for the large-scale apparatus had begun.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Smart Contracts for Power Grid Applications Using the Advanced DLT Cyber Grid Guard Testbed

In this study is presented two power system applications with distributed ledger technology (DLT) and smart contracts (SC) that were assessed in a Cyber-Grid-Guard System (CGGS) advanced testbed, with protective relays, power meters, communication devices, DLT devices, synchronized time source, clock displays and real time simulator. This CGGS testbed was set in the Advanced Protection Lab, 252 lab space of the Grid Research Integration and Deployment Center (GRID- C), at Oak Ridge National Laboratory. In power grids, customer-owned distributed energy resources (DERs) are more frequent than in the past, and the numbers of points of interconnection (POI) with customer-owned DERs have increased. Disruptive operation from DERs presents a risk to grid operations, and protective relays located at the POI are used to isolate out-of-tolerance or poorly behaving of DERs. Ensuring the integrity of data from the relays at the POI, and DLT could enhance the security of the power grids. The first application is a SC to define and control the allowable total power factor (TPF) of the DER (wind farm) output, and the terms of the SC are implemented using DLT with a CGGS for a customer-owned DER. The TPF SC was implemented by the CGGS using DLT. The experimental model was performed with a real-time simulator using a CGGS and relay in-the-loop. The data collected from the CGGS were used to execute the TPF SC. The TPF limits were between +0.9 and +1.0, and the breakers’ operation in the POI was controlled by the relay using the SC. The events were collected from the real-time simulator, CGGS, and SEL 700GT relay to validate a successful application of the TPF SC using DLT. The second application is a SC to measure and control the allowable voltage service limits (VSL) by the CGGS using DLT. The tests were performed by using a real-time simulator, CGGS and relay in-the-loop. The data was collected from the CGGS that executed the SC. The main constraints were defined based on ANSI C84.1 service voltage limits, and the operation of the breakers in the POI. The events were collected from the CGGS, and SEL 700GT relay to assess a successful operation of the VSL SC using DLT.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Reactive-transport modeling of fracture flow to quantify the changes in flow pathways from matrix thermal contraction and mineral precipitation and dissolution; influence of grid resolution

A series of reactive-transport models of Enhanced Geothermal Systems (EGS) were constructed using the reactive transport code PFLOTRAN to examine the effect of matrix thermal contraction and mineral dissolution/precipitation on fracture flow in the context of grid cell size and model complexity. It was found that for thermal drawdown at production well, the impact of fracture zone grid cell size is negligible.

Gatz-Miller, Hannah Sarah↗
DOE OSTI2022

Contracting and Expanding Binary Black Holes in 3D Low-mass AGN Disks: The Importance of Separation

LIGO/Virgo has detected several binary black hole (BBH) merger events that may have originated in the accretion disks of active galactic nuclei (AGNs). These events require individual black hole masses that fall within the pair instability supernova mass gap, and therefore these black holes may have been grown from hierarchical mergers. AGN disks are a prime environment for hierarchical mergers and thus a potential location for the progenitors of BBH gravitational wave events. Understanding how a BBH embedded in an AGN disk interacts with the surrounding environment is thus crucial for determining whether this interaction can lead to its merger. However, there are few high-fidelity simulations of this process, and almost all are two-dimensional. We present the results from 3D, high-resolution, local shearing-box simulations of an embedded BBH interacting with an AGN disk. In these first simulations of their kind, we focus on determining the mass accretion rate and the orbital evolution rate at different BBH separations. We find that circular, equal-mass BBHs with separations greater than 10% of their Hill radius contract while accreting at a super-Eddington rate. At smaller separations, however, our 3D simulations find that BBHs expand their orbits. This result suggests that it may be difficult for an AGN disk to push a BBH to merger, but we discuss several mechanisms, including MHD turbulence and radiative and mechanical feedback, which could alleviate this difficulty.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

Athena: High-Performance Sparse Tensor Contraction Sequence on Heterogeneous Memory

Sparse tensor contraction sequence has been widely employed in many fields, such as chemistry and physics. However, how to efficiently implement the sequence faces multiple challenges, such as redundant computations and memory operations, massive memory consumption, and inefficient utilization of hardware. To address the above challenges, we introduce Athena, a high-performance framework for SpTC sequences. Athena introduces new data structures, leverages emerging Optane-based heterogeneous memory (HM) architecture, and stage parallelism. In particular, Athena introduces shared hash table-represented sparse accumulator to eliminate unnecessary input processing and data migration; Athena uses a novel data-semantic guided dynamic migration solution to make the best use of the Optane-based HM for high performance; Athena also co-runs execution phases with different characteristics to enable high hardware utilization. Evaluating with 12 datasets, we show that Athena brings 327-7362× speedup over the state-of-the-art SpTC algorithm. With the dynamic data placement guided by data semantics, Athena brings performance improvement on Optane-based HM over a state-of-the-art software-based data management solution, a hardware-based data management solution, and PMM-only by 1.58×, 1.82×, and 2.34× respectively.

Liu, Jiawen↗
DOE OSTI2022

Federal Energy Savings Performance Contracts Frequently Asked Questions on the Scope of 42 U.S.C. § 8287 et. seq.

The U.S. Department of Energy's Federal Energy Management Program (FEMP) is issuing this document to provide clarifications and guidance on issues commonly raised regarding the scope of 42 U.S.C. § 8287 et seq. This document is intended to supplement FEMP's extensive collection of materials that are available to assist federal agencies execute successful energy savings performance contracting (ESPC) projects.

42 U.S.C. § 8287 et. seq.↗
DOE OSTI2024

Leveraging Energy Sales Agreements (ESA) Under ESPC ENABLE and DOE's IDIQ Contract

There is an increasing interest in solar photovoltaics, battery energy storage systems, and geothermal heat pumps to help meet decarbonization and resilience goals. However, facility managers may not know that energy sales agreement (ESA) contracting can be an effective, efficient, and lower cost way to procure and install these projects. FEMP, national labs, and agency partners will discuss best practices and examples that attendees may be able to leverage at their own sites.

DOE FEMP↗
DOE OSTI2021

Blockchain-Based Smart Contracts Use for Photovoltaic Energy Trade Transactions

In recent decades, interest in renewable energy via solar energy has increased, especially in California and Nevada. In a region that can produce enough solar power for self-use, prosumers must use or sell surplus energy. Solar energy self-consumption is essential in modern energy transactions in the grid. This paper proposes an approach towards grid services that includes photovoltaic hardware to store the excess energy in battery storage. Such energy can then be sold to power companies while the transaction is handled using blockchain. Software, security architecture and data flow requirements based on the Ethereum Blockchain are included. Furthermore, this solution protects the private information of seller and buyer and secures transactions.

14 SOLAR ENERGY↗
DOE OSTI2023

Graphically Contracted Function Construction with the Recursive Pairwise Merge Algorithm

A new implementation of a recursive pairwise merge algorithm to construct a GCF from a list of CSF expansion coefficients is presented. The essential new feature is the preallocation of some work arrays used within the intermediate steps of the merge procedure. This results in roughly an order of magnitude improvement in overall efficiency and also approximately eliminates a factor of n, the molecular orbital dimension, from the original implementation. Initial application of this merge procedure to a series of H m molecules shows that the GCF wave functions can be represented well both with delocalized canonical Hartree-Fock orbitals and with localized molecular orbitals. Finally, for a given wave function complexity, as measured by the average facet count, $\bar{\text {f}}$, the delocalized Hartree-Fock orbitals show smaller errors for small $\bar{\text {f}}$ values, while the localized orbitals show smaller errors for larger $\bar{\text {f}}$ values.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Appropriations and Financing: Strategic Use of Funding for Performance Contracts

42 U.S.C. § 8253 Sections 432 and 512 (EISA of 2007) authorize agencies to use appropriations, private financing, or a combination of appropriations and private financing to comply with its requirements. With this flexibility in mind, federal agencies should evaluate funding options early and employ a strategy that optimizes the impact of existing appropriations and financing options. Maximize value to government through strategic use of appropriations and energy savings, an optimal set of infrastructure improvements that meet site needs and program objectives, and an actionable plan for sustained performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Blockchain Smart Contract Reference Framework and Program Logic Architecture for Transactive Energy Systems

This paper proposes a reference framework for a transactive energy market based on blockchain. The framework was designed based on the engineering requirements of a distribution-scale market; including participant needs, expected market transactions, and the cybersecurity constructs required to support a fair, secure and efficient market operation. It leverages the existing blockchain primitives to provide clear value propositions to the transactive market, including identity management (access control), data security (integrity), resiliency (decentralization, scalability and performance). The validity of the proposed framework is demonstrated using a real-time 5-min double-auction market. The results highlight its benefits while providing strong validation of applicability to blockchain within transactive energy systems.

Gourisetti, Sri Nikhil Gupta↗
DOE OSTI2021

Ionic Contraction across the Lanthanide Series Decreases the Temperature-Induced Disorder of the Water Coordination Sphere

In liquid, temperature affects the structures of lanthanide complexes in multiple ways that depend upon complex interactions between ligands, anions, and solvent molecules. The relative simplicity of lanthanide aqua ions (Ln 3+ ) make them well suited to determine how temperature induces structural changes in lanthanide complexes. In this work, we performed a combination of ab initio molecular dynamics (AIMD) simulations and extended X-ray absorption fine structure (EXAFS) measurements, both at 25 and 90 °C, to determine how temperature affects the first- and second-coordination spheres of three Ln 3+ (Ce 3+ , Sm 3+ , and Lu 3+ ) aqua ions. AIMD simulations show first lanthanide coordination spheres that are similar at 25 and 90 °C, more so for the Lu 3+ ion that remains as eight-coordinate than for the Ce 3+ and Sm 3+ ions that change their preferred coordination number from nine (at 25 °C) to eight (at 90 °C). The measured EXAFS spectra are very similar at 25 and 90 °C, for the Ce 3+ , Sm 3+ , and Lu 3+ ions, suggesting that the dynamical disorder of the Ln 3+ ions in liquid water is sufficient such that temperature-induced changes do not clearly manifest changes in the structure of the three ions. Both AIMD simulations and EXAFS measurements show very similar structures of the first coordination sphere of the Lu 3+ ion at 25 and 90 °C.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗