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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Analytical and Performance-Based Evaluation Alternatives to Full-Scope, High-Fidelity Testbeds

One consequence the design and operational differences of advanced reactors is that integrated system validation (ISV) using full-scope, high-fidelity testbed might not be cost-justified or practical. The absence of traditional ISV may pose an issue for the conduct of safety evaluations since it may leave regulators without the information derived from this performance-based testing. The purpose of this research is to identify analytical and performance-based test and evaluation methods that are alternatives to full-scope, high-fidelity testbeds that have traditionally been used for ISV. We developed a method to test validation based on a multi-stage validation (MSV) framework. MSV is an approach to meeting validation objectives through incremental, successive validation activities beginning in the early stages of the design process and continuing through the later stages. MSV doesn't rely solely on late stage validation, rather it accommodates the use of a broad spectrum of analytical and performance-based information and a diversity of testbeds. In addition, MSV embraces the use of information from other types of evaluations and analyses.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2025

Hydrogen Plus Other Alternative Fuels Risk Assessment Models (HyRAM+) Technical Reference Manual (V.6.0)

The HyRAM+ software is an open-source toolkit that provides publicly available models and default input values to enable straightforward and consistent safety assessments for hydrogen and other alternative fuel systems, such as natural gas and propane. The HyRAM+ quantitative risk assessment calculation incorporates annual likelihood of leaks or failures for both compressed gaseous and liquefied flammable fuels, as well as probabilistic models for the effects of heat flux and overpressure. HyRAM

08 HYDROGEN↗
DOE OSTI2025

Feasibility Assessment and Preliminary Design of a Low Cost, Modular Concrete, Suction Pile Support Structure and Heavy Lift Vessel Alternative (CRADA Final Report)

The project goal is to prove the feasibility and advance the development of a low-cost, modular concrete suction pile support structure and heavy lift vessel alternative for offshore wind deployment in the United States. These technology developments are critical to alleviating specific challenges faced by the United States market, including a limited number of Jones Act-compliant installation vessels and environmental restrictions associated with using conventional offshore wind foundations. The first phase of this project is a conceptual design and feasibility assessment of modular concrete substructure options for NREL’s 15 MW reference turbine.

17 WIND ENERGY↗
DOE OSTI2023

2D Seismic Surveys as an Alternative for CO 2 Monitoring in the North Dakota CarbonSAFE Project

Conference presentation for International Meeting for Applied Geoscience & Energy (IMAGE), Houston, TX, August 28 – September 1, 2023. As part of the North Dakota CarbonSAFE project, seismic, controlled-source electromagnetic, and microgravity baseline monitoring surveys were collected to assess the safe, permanent, commercial-scale geologic storage of CO 2 generated by the Milton R. Young coal-fired power plant. Data from five 2D seismic lines were assessed as an alternative to 3D seismic for CO 2 monitoring. 2D and 3D surveys were compared using wave equation-based (WEB)-AVO inversion. The encouraging WEB-AVO results demonstrated that 2D surveys could be included in CO 2 monitoring programs as a cost-effective method.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2025

Community Solar Consolidated Billing: An Exploration of Implementation and Alternatives [Slides]

This presentation is an abridged version of the report it is based on that presents an analysis of the considerations, costs, and benefits surrounding the implementation of utility consolidated billing in community solar programs while also exploring alternatives to achieve similar benefits in its absence. Consolidated billing simplifies the billing process for customers by combining all charges and credits associated with electricity service and community solar subscriptions into a single bill. The potential benefits of consolidated billing implementation include increased transparency, improved customer experience, and ultimately increased retention rates and decreased subscriber acquisition costs. Currently, community solar subscribers often receive two separate bills - one from the utility and one from a third-party community solar provider - potentially causing confusion. Consolidated billing seeks to resolve this by offering a unified bill, which, while beneficial to numerous stakeholders, presents administrative, technical, and financial hurdles that utilities and program administrators must address.

14 SOLAR ENERGY↗
DOE OSTI2026

Comparing Synthetic Routes and Thermal Characteristics of Alternate APO Variants

Low density, high-strength, temperature-resistant foams see widespread application in the aerospace and weapons fields due to their excellent qualities as structural supports. In these demanding environments, the most common formulation is a three-phase syntactic foam containing APOCure-601, BMI, and carbon or glass microballoons. Of these, APOCure-601 and BMI form the polymer resin amino-poly(oxadiazole) bismaleimide (APO-BMI), also known as Legacy APO or S-1,2-Ethyl-APO. In manufacturing this foam, the selective laser sintering (SLS) additive manufacturing technique is quickly gaining prominence, over more traditional injection molding since SLS allows for 3D printing of materials and reduces overall cost and waste production. That said, SLS also requires a narrow window between the melt and cure temperatures for a successful print. SLS printing of APO-BMI is therefore difficult since the compound possesses a broad window between its melting and curing temperatures, and also requires several post-cure steps or complete polymerization. This work explores synthesis optimization and thermal characteristics for variant Apo-BMI structures by observing the effect that alternative heteroatoms in the APO linkages, geometries 0f the BMI groups, and bridge structure identities impart on the resultant material. Synthetic methods for these altered structures were established in batch, with some others further converted to continuous flow chemistry, a method that produces materials in a continuous stream and is highly reproducible and readily scaled. Additionally, each structural change significantly altered the melt and cure properties for each APO variant, which is advantageous for SLS manufacturing.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

An Alternative Conceptual Model for the Spent Nuclear Fuel–Water Interaction in Deep Geologic Disposal Conditions

For the long-term safety assessment of direct disposal of spent nuclear fuel in deep geologic repositories, knowledge on the radionuclide release rate from the UO 2 matrix is essential. This work provides a conceptual model to explain the results of leaching experiments involving used nuclear fuel or simulant materials in confirmed reducing conditions. Key elements of this model are: direct effect of radiation from radiolytic species (including defects and excited states) in the solid and in the first water layers in contact with its surface; and excess H 2 may be produced due to processes occurring at the surface of the spent fuel and in confined water volumes, which may also play a role in keeping the spent fuel surface in a reduced state. The implication is that the fractional radionuclide release rate used in most long-term safety assessments (10 -7 year -1 ) is over estimated because it assumes that there is net UO 2 oxidation caused by radiolysis, in contrast with the alternative conceptual model presented here. Furthermore, conventional water radiolysis models and radiation chemical yields published in the literature are not directly applicable to a heterogeneous system such as the spent fuel–water interface. Suggestions are provided for future work to develop more reliable models for the long-term safety assessment of spent nuclear fuel disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Mutations in the Second Alternative Oxidase Gene: A New Approach to Group Aspergillus niger Strains

Alternative oxidase is a terminal oxidase in the branched mitochondrial electron transport chain of most fungi including Aspergillus niger (subgenus Circumdati, section Nigri). A second, paralogous aox gene (aoxB) is extant in some A. niger isolates but also present in two divergent species of the subgenus Nidulantes—A. calidoustus and A. implicatus—as well as in Penicillium swiecickii. Black aspergilli are cosmopolitan opportunistic fungi that can cause diverse mycoses and acute aspergillosis in immunocompromised individuals. Amongst the approximately 75 genome-sequenced A. niger strains, aoxB features considerable sequence variation. Five mutations were identified that rationally affect transcription or function or terminally modify the gene product. One mutant allele that occurs in CBS 513.88 and A. niger neotype strain CBS 554.65 involves a chromosomal deletion that removes exon 1 and intron 1 from aoxB. Another aoxB allele results from retrotransposon integration. Three other alleles result from point mutations: a missense mutation of the start codon, a frameshift, and a nonsense mutation. A. niger strain ATCC 1015 has a full-length aoxB gene. The A. niger sensu stricto complex can thus be subdivided into six taxa according to extant aoxB allele, which may facilitate rapid and accurate identification of individual species

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Gravitational Fluctuations as an Alternative to Inflation II. CMB Angular Power Spectrum

Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum P(k) and the CMB temperature angular power spectrum C l ’s to high accuracy is often considered a triumph of inflation. In our previous work, we presented an alternative explanation for the matter power spectrum based on nonperturbative quantum field-theoretical methods applied to Einstein’s gravity, instead of inflation models based on scalar fields. In this work, we review the basic concepts and provide further in-depth investigations. We first update the analysis with more recent data sets and error analysis, and then extend our predictions to the CMB angular spectrum coefficients C l , which we did not consider previously. Then we investigate further the potential freedoms and uncertainties associated with the fundamental parameters that are part of this picture, and show how recent cosmological data provides significant constraints on these quantities. Overall, we find good general consistency between theory and data, even potentially favoring the gravitationally-motivated picture at the largest scales. We summarize our results by outlining how this picture can be tested in the near future with increasingly accurate astrophysical measurements.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Early time solution as an alternative to the late time evolving dark energy with DESI DR2 BAO

Recently the Dark Energy Spectroscopic Instrument (DESI) provided constraints on the expansion history from their Data Release 2 (DR2). The DESI baryon acoustic oscillation (BAO) measurements are well described by a flat $\Lambda$CDM model, but the preferred parameters are in mild ($2.3\sigma$) tension with those determined from the cosmic microwave background (CMB). The DESI collaboration has already explored a variety of solutions to this tension relying on variations in the late-time evolution of dark energy. Here we test an alternative -- the introduction of an ``early dark energy'' (EDE) component. We find that EDE models can alleviate the tension, though they lead to differences in other cosmological parameters that have observational implications. Particularly the EDE models that fit the acoustic datasets prefer lower $\Omega_m$, higher $H_0$, $n_s$ and $\sigma_8$ in contrast to the late-time solutions. We discuss the current status and near-future prospects for distinguishing amongst these solutions.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Tracking alternative versions of the galactose gene network in the genus Saccharomyces and their expansion after domestication

In this yeast, the study of trait variation at the population level led to the detection of distinct sets of GAL structural genes. Besides the reference version, present in most strains, alternative highly divergent alleles supporting faster growth on galactose were recently uncovered in strains associated with dairy products and also in some wild strains.

Genetics↗
DOE OSTI2020

Combustor assembly for low-emissions and alternate liquid fuels

Implementations of a combustor assembly yield low emissions, require low power, are suitable for alternate liquid fuels, including highly viscous fuels, and are scalable for various heat release rates. The combustor assembly includes a fuel injector and a swirler. The fuel injector may include a choke portion and a spacer. The choke portion is disposed just upstream of an outlet of a liquid fuel conduit and prevents atomizing gas from interrupting continuous flow of the liquid fuel through the liquid fuel conduit. The spacer is disposed downstream of the outlet to precisely control the gap and thus, bifurcation of atomizing gas flow, between the outlet of liquid fuel conduit and an inlet of an orifice plate. The swirler is disposed radially outwardly and adjacent the fuel injector and includes a plurality of angled vanes.

42 ENGINEERING↗
DOE OSTI2020

Fuel injector including a lobed mixer and vanes for injecting alternate fuels in a gas turbine

A fuel injector for injecting alternate fuels having a different energy density in a gas turbine is provided. A first fuel supply channel (18) may be fluidly coupled to a radial passage (22) in a plurality of vanes (20) that branches into passages (24) (e.g., axial passages) to inject a first fuel without jet in cross-flow injection. This may be effective to reduce flashback in fuels having a relatively high flame speed. A mixer (30) with lobes (32) for injection of a second fuel may be arranged at the downstream end of a fuel delivery tube (12). A fuel-routing structure (38) may be configured to route the second fuel within a respective lobe so that fuel injection of the second fuel takes place radially outwardly relative to a central region of the mixer. This may be conducive to an improved (e.g., a relatively more uniform) mixing of air and fuel.

42 ENGINEERING↗
DOE OSTI2020

Systems and methods for augmenting a satellite based navigation system with alternative position and timing data

Various technologies pertaining to integrating a positioning or timing solution from an alternative position, navigation, or timing (PNT) system into a satellite-based-navigation system are described herein. The PNT system generates a position/timing (P/T) solution that indicates a current position or current time of the PNT system. The P/T solution is provided as input to a simulation of a satellite constellation of the satellite-based-navigation system, and a constellation signal is generated based on the simulation and the P/T solution. The constellation signal is formatted according to a navigation signal format of the satellite-based-navigation system such that when the constellation signal is provided to a receiver of the satellite-based-navigation system, the receiver computes a P/T solution that indicates the current position or the current time identified by the PNT system.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2021

Method and apparatus for ion mobility separations utilizing alternating current waveforms

Methods and apparatuses for ion manipulations, including ion trapping, transfer, and mobility separations, using traveling waves (TW) formed by continuous alternating current (AC) are disclosed. An apparatus for ion manipulation includes a surface to which are coupled a first plurality of continuous electrodes and a second plurality of segmented electrodes. The second plurality of segmented electrodes is arranged in longitudinal sets between or adjacent to the first plurality of electrodes. An RF voltage applied to adjacent electrodes of the first plurality of electrodes is phase shifted by approximately 180° to confine ions within the apparatus. An AC voltage waveform applied to adjacent electrodes within a longitudinal set of the second plurality of segmented electrodes is phase shifted on the adjacent electrodes by 1°-359° to move ions longitudinally through the apparatus for separation.

Garimella, Venkata B. S.↗
DOE OSTI2022

MOPED: An Alternative Workflow for HERON

MOPED is an alternate workflow to HERON. Preliminary tests display computational advantages of MOPED in terms of run time. While maintaining these advantages, solution convergence remained similar.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗