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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

High Frequency Transverse Instabilities in Low NOx Gas Turbines

This program addresses the topic of combustion instabilities under the goal of developing “Low-NOx Combustion Technology for ‘Air-Breathing’ Advanced Turbines”. With recent advances in high-temperature withstanding materials, the push towards higher efficiency has resulted in efforts to design high temperature, low NOx gas turbines. The development of such low NOx systems is often plagued with combustion instabilities. These instabilities manifest with acoustic modes that are longitudinal, transverse or both. A large body of literature and work exists addressing the underlying mechanisms and models for longitudinal instabilities and these have been successfully implemented in the design tools for low NOx gas turbines. The flame response aspect of the thermoacoustic feedback loop was often modeled in an acoustically compact framework since for low frequencies, the flame length scale was small compared to the acoustic wavelength. This enabled simplification where the modeling focused only on the overall flame response and not the local spatial distribution of the flame response. In addition, additional mechanisms such as the direct effect of pressure fluctuations on the flame response could be neglected. In contrast, high frequency instabilities which often are transverse in nature, have received relatively less attention in the literature. The flame is no longer acoustically compact and thus the local distribution of heat release must be accurately understood. The flame responds to velocity fluctuations, equivalence ratio fluctuations as before, but also to pressure fluctuations through kinetic effects. These aspects of high-frequency instabilities make it a challenging problem that requires a detailed elucidation of the underlying mechanisms and creating models for them. In this program we significantly improved the understanding of these instabilities through a combination of experiments (informed by interactions with OEMs), modeling of measured data and reduced order modeling of flame response. The results from the program can be used as basis for robust design tools that are essential for successfully developing gas turbines that operate in an environmentally acceptable manner with mitigation strategies for high-frequency instabilities.

08 HYDROGEN↗
DOE OSTI2023

LANSCE CCL Performance Limits

This report summarizes the performance limits of the LANSCE Coupled-Cavity Linac (CCL). These results are captured or summarized directly from the references cited. This report was written in support of the LANSCE Modernization Project (LAMP). Many factors contribute to the performance limits of the CCL accelerator system. One performance limit is set by the CCL mechanical structure and available cooling. Heating of the structure is ultimately linked to the operating RF duty factor of the CCL. Another performance limit is set by the maximum RF and beam duty factors that can be supported by the 805-MHz klystrons and associated HVDC power supplies. The RF and HVDC systems also set limits for the maximum peak beam current that can be accelerated in the CCL. And finally, a maximum beam current limit is set by the beam dynamics determined by the details of the CCL physics design (number of cells per CCL tank, accelerating gradients, magnetic focusing lattice, beam losses, etc.). This limit can be informed by both simulation results and beam measurement data, if available. A detailed explanation of each performance limit is given in the sections below. The results are summarized in the table below. In all cases, it is assumed that the CCL and the RF system are operating in their nominal beam production configuration – nominal magnet set points and nominal cavity fields, unless otherwise specified.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Sister Rod Destructive Examinations (FY22) Appendix B: Segmentation, Defueling, Metallographic Data and Total Cladding Hydrogen

This report documents work performed under the Spent Fuel and Waste Disposition’s Spent Fuel and Waste Science and Technology program for the US Department of Energy (DOE) Office of Nuclear Energy (NE). This work was performed to fulfill Level 2 Milestone M2SF-23OR010201024, “FY22 Report on ORNL Sibling Rod Testing Results,” within work package SF-23OR01020102 and is an update to the work reported in M2SF-22OR010201047, M2SF-21OR010201032, M2SF-19ORO010201026, and M2SF 19OR010201028. As a part of the DOE-NE High Burnup Spent Fuel Data Project, Oak Ridge National Laboratory (ORNL) is performing destructive examinations (DEs) of high burnup (HBU) (>45 GWd/MTU) spent nuclear fuel (SNF) rods from the North Anna Nuclear Power Station operated by Dominion Energy. The SNF rods, called sister rods or sibling rods are all HBU and include four different kinds of fuel rod cladding: standard Zircaloy-4 (Zirc-4), low-tin (LT) Zirc-4, ZIRLO ® , and M5 ® . Appendix B provides detailed information regarding defueling activities, metallographic imaging and measurements, and total cladding hydrogen measurements.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Progress on Associated-Particle Imaging Algorithms, 2022

The present work describes progress on developing imaging algorithms that use fast neutron signatures acquired using the associated-particle imaging (API) method. The present work complements ongoing work to develop neutron source and detector hardware to enable field inspection by investigating algorithms that are capable of discriminating among critical materials or extracting three-dimensional (3D) geometrical information from single-sided or transmission measurements. The present work is divided into three approaches: 1.Iterative reconstruction of inelastic gamma-ray emissions to perform 3D time-of-flight (TOF) imaging in a single view in either transmission or backscatter configurations. Iterative reconstruction enables image resolution better than the inherent TOF resolution. 2.Decomposition of registered neutron and x-ray radiographs into an assumed material list for each pixel in the image. 3.Material identification using full spectral analysis that includes the emergent neutron and gamma ray energies, times, and angles. Progress for each approach is summarized for fiscal year (FY) 2022.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

Perspectives on AI Architectures and Co-design for Earth System Predictability

Recently, the U.S. Department of Energy (DOE), Office of Science, Biological and Environmental Research (BER), and Advanced Scientific Computing Research (ASCR) programs organized and held the Artificial Intelligence for Earth System Predictability (AI4ESP) workshop series. From this workshop, a critical conclusion that the DOE BER and ASCR community came to is the requirement to develop a new paradigm for Earth system predictability focused on enabling artificial intelligence (AI) across the field, laboratory, modeling, and analysis activities, called model experimentation (ModEx). BER’s ModEx is an iterative approach that enables process models to generate hypotheses. The developed hypotheses inform field and laboratory efforts to collect measurement and observation data, which are subsequently used to parameterize, drive, and test model (e.g., process based) predictions. A total of 17 technical sessions were held in this AI4ESP workshop series. This paper discusses the topic of the AI Architectures and Codesign session and associated outcomes. The AI Architectures and Codesign session included two invited talks, two plenary discussion panels, and three breakout rooms that covered specific topics, including 1) DOE high-performance computing (HPC) systems, 2) cloud HPC systems, and 3) edge computing and Internet of Things (IoT). We also provide forward-looking ideas and perspectives on potential research in this codesign area that can be achieved by synergies with the other 16 session topics. These ideas include topics such as 1) reimagining codesign, 2) data acquisition to distribution, 3) heterogeneous HPC solutions for integration of AI/ML and other data analytics like uncertainty quantification with Earth system modeling and simulation, and 4) AI-enabled sensor integration into Earth system measurements and observations. Such perspectives are a distinguishing aspect of this paper.

58 GEOSCIENCES↗
DOE OSTI2024

Carl T. Hayden Veterans Affairs Medical Center: Smart Buildings Case Study

The purpose of this smart buildings case study is to showcase a leading example of a GEB renovation project in the federal buildings space and provide key information on the technology and control upgrades, costs, and energy and utility bill savings. This case study also provides information and recommendations for selecting energy conservation measures (ECMs) and choosing energy and cost reduction strategies from the energy management team at the site. The findings from this successful GEB project can be used to help pave the way for additional GEB retrofits in the future. The Carl T. Hayden Veterans Affairs (VA) Medical Center in Phoenix, Arizona, demonstrates that GEB strategies and technologies can be realistically deployed today across buildings with substantial energy and cost savings. The project implemented both ECMs and grid-interactive technologies and controls strategies, making it a leading example of a smart, sustainable, and efficient commercial building.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Geant4 Simulations and Experimental Results for the Pacific-Ocean Neutrino Experiment (P-ONE)

The Pacific-Ocean Neutrino Experiment (P-ONE) is an upcoming large-volume neutrino telescope planned to be built off the coast of Vancouver Island, Canada. It aims to detect high-energy neutrinos via the Cherenkov radiation produced in water by secondary particles born from high-energy neutrino interactions. Its first set of detectors is planned to be commissioned this year. However, since the telescope is still in its early stages of development, many tests and simulations must still be run to characterize the efficacy of the detectors. One necessary simulation must be devoted towards examining whether the polarization of the incoming Cherenkov light impacts the strength of the signals by the PMTs, and it must be supported by experimental data. In this report, I detail what I have completed during my SULI internship at the Los Alamos National Lab (LANL); I present the preliminary results of a Geant4 polarization simulation as well as preliminary laboratory measurements that will later be used to inform the future P-ONE design.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2023

CCUS Plume Monitoring: Verifying Surface CSEM Measurements to Log Scale Available

Conference presentation at Society of Petrophysicists and Well Log Analysts (SPWLA) 64th Annual Symposium, Lake Conroe, Texas, June 10–14, 2023. In carbon capture, utilization, and storage (CCUS) monitoring, dynamic plume monitoring and reservoir seal are key issues. Plume monitoring is best addressed with electromagnetics (sensitive to the resistivity contrast) and reservoir leakage with microseismics. A case history from North Dakota illustrates how we can tie surface-controlled source electromagnetic (CSEM) measurements to the three-dimensional (3D) anisotropic models derived from the available logs. This allows us to certify baseline measurements within the context of the borehole information.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2023

Cost of Fish Exclusion Technologies for Hydropower

This dataset compiles data on the costs of environmental mitigations related to fish exclusion for 35 hydropower projects based on documents obtained from the U.S Federal Energy Regulatory Commission (FERC). Data for all measures and their associated project-specific information, including installed and hydraulic capacities, were manually extracted from environmental impact statements and/or environmental assessment (EIS/EA) documents. All data were consolidated in a comma-separated (.csv) file, referred to as the Cost of Fish Exclusion Technologies for Hydropower Database.

13 HYDRO ENERGY↗
DOE OSTI2021

The moderately defficient enzyme: Catalysis-related damage in vivo and its repair

Enzymes have in vivo lifespans. Analysis of lifespans – lifetime totals of catalytic turnovers – suggests that non-survivable collateral chemical damage from the very reactions that enzymes catalyze is a common but underdiagnosed cause of enzyme death. Analysis also implies that many enzymes are moderately deficient in that their active-site regions are not naturally as hardened against such collateral damage as they could be, leaving room for improvement by rational design or directed evolution. Enzyme lifespan might also be improved by engineering systems that repair otherwise fatal active-site damage, of which a handful are known and more are inferred to exist. Unfortunately, the data needed to design and execute such improvements is lacking: there are too few measurements of in vivo lifespan, and existing information on the extent, nature, and mechanisms of active-site damage and repair during normal enzyme operation is too scarce, anecdotal, and speculative to act on. Fortunately, advances in proteomics, metabolomics, cheminformatics, comparative genomics, and structural biochemistry now empower a systematic, data-driven approach to identify, predict, and validate instances of active-site damage and its repair. These capabilities would be practically useful in enzyme redesign and improvement of in-use stability, and could change thinking about which enzymes die young in vivo, and why.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

The moderately defficient enzyme: Catalysis-related damage in vivo and its repair

Enzymes have in vivo lifespans. Analysis of lifespans – lifetime totals of catalytic turnovers – suggests that non-survivable collateral chemical damage from the very reactions that enzymes catalyze is a common but underdiagnosed cause of enzyme death. Analysis also implies that many enzymes are moderately deficient in that their active-site regions are not naturally as hardened against such collateral damage as they could be, leaving room for improvement by rational design or directed evolution. Enzyme lifespan might also be improved by engineering systems that repair otherwise fatal active-site damage, of which a handful are known and more are inferred to exist. Unfortunately, the data needed to design and execute such improvements is lacking: there are too few measurements of in vivo lifespan, and existing information on the extent, nature, and mechanisms of active-site damage and repair during normal enzyme operation is too scarce, anecdotal, and speculative to act on. Fortunately, advances in proteomics, metabolomics, cheminformatics, comparative genomics, and structural biochemistry now empower a systematic, data-driven approach to identify, predict, and validate instances of active-site damage and its repair. These capabilities would be practically useful in enzyme redesign and improvement of in-use stability, and could change thinking about which enzymes die young in vivo, and why.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Spatial Mapping of Riverbed Grain-Size Distribution Using Machine Learning

Recent alluvial sediments in riverbeds play a significant role in controlling hydrologic exchange flows (HEFs) in river systems. The alluvial layer is usually associated with strong heterogeneity in physical properties (e.g., permeability and hydraulic conductivity), which affects local HEFs and therefore biogeochemical processes. The spatial distribution of these physical properties needs to be determined to inform the numerical models used to reveal the realistic hydro-biogeochemical behaviors. Such information can be obtained based on the intrinsic link between sediment grain-size distribution and hydraulic properties where sediment texture information is available. However, grain-size measurements are usually spatially sparse and do not have adequate coverage and resolution, particularly for a relatively large domain such as the Hanford Reach of the Columbia River. In this paper, we adopted machine learning (ML) approaches for categorizing and mapping the spatial distributions of riverbed substrate grain size and filling in missing areas of substrate data using the ML models along the reach. Such ML models for substrate size mapping were trained at 13,372 locations using measured substrate sizes along with observed and simulated attributes, including bathymetric attributes (e.g., elevation, slope, and aspect ratio) from LIDAR and bathymetric surveys, and hydrodynamic properties (e.g., water depth, velocity, shear stress, and their statistical moments). An ensemble bagging-based ML technique, Random Forest, was adopted to identify the most influential factors as predictors to develop the predictive models with over-fitting issues addressed. The models were evaluated with respect to each individual substrate size class and the lumped group, and then used to generate the final substrate size maps covering all the grid cells in the numerical modeling domain.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Searching for multimessenger transients and lensed supernovae with the dark energy survey

Advances in data collection technology for optical astronomy, such as the Dark Energy Camera, have facilitated the collection of some of the largest astronomical datasets in terms of sky area, depth, number of objects, number of observations, and frequency of observations. Consequentially, physical systems that have been historically rare become represented in small, but discoverable, numbers. I have developed techniques to identify rare physical systems (counterparts to high-energy neutrinos, counterparts to gravitational waves, and gravitationally lensed supernovae) that can shed new light on the physical processes that govern the Universe. For each system of interest, I collect new or search archival observations with the Dark Energy Camera, develop selection methodologies to find the system of interest in the observations, and quantify the efficiency of the search using simulations. Each of the three analyses has its own scientific implications: I constrain the observing program required to determine the contribution of supernovae to the diffuse high-energy neutrino flux; I set constraints on the physical properties of an optical counterpart to a compact object merger; and I identify candidate lensed supernovae using a novel machine learning technique. Looking forward, the work presented in this dissertation informs future rare object searches and facilitates measurements of the underlying properties of the Universe during the next era of optical survey astronomy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Efficiency Studies of Fast Neutron Tracking Using MCNP

Fast neutron identification and spectroscopy is of great interest to nuclear physics experiments. Using the neutron elastic scattering, the fast neutron momentum can be measured. Wang and Morris introduced the theoretical concept that the initial fast neutron momentum can be derived from up to three consecutive elastic collisions between the neutron and the target, including the information of two consecutive recoil ion tracks and the vertex position of the third collision or two consecutive elastic collisions with the timing information. Here, we also include the additional possibility of measuring the deposited energies from the recoil ions. In this paper, we simulate the neutron elastic scattering using the Monte Carlo N-Particle Transport Code (MCNP) and study the corresponding neutron detection and tracking efficiency. The corresponding efficiency and the scattering distances are simulated with different target materials, especially natural silicon (92.23%28Si, 4.67%29Si, and 3.1%30Si) and helium-4 (4He). The timing of collision and the recoil ion energy are also investigated, which are important characters for the detector design. We also calculate the ion traveling range for different energies using the software, “The Stopping and Range of Ions in Matter (SRIM)”, showing that the ion track can be most conveniently observed in 4He unless sub-micron spatial resolution can be obtained in silicon.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Gold L-shell emission spectroscopy as a temperature diagnostic in laser-driven experiments

Measurements of plasma conditions within gold hohlraums are challenging but provide important information about hohlraum energy transport. To date, there are no reliable passive diagnostic approaches that produce information about the hohlraum plasma conditions. Gold L-shell emission spectroscopy is a promising method to measure the electron temperature in multi-keV gold hohlraum plasmas. In this study, we compare time-resolved measurements of gold L-shell spectra against a more conventional electron temperature-sensitive diagnostic, K-shell emission from zinc, a mid-Z dopant. The Au L-shell and Zn K-shell spectra are taken simultaneously. The analysis of both sets of data exhibits good agreement with a singular rad-hydro model, suggesting a similar evolution in the mean electron temperature of the hohlraum plasma. These findings support the use of L-shell spectroscopy of gold as a method to study gold plasma conditions.

Emission spectroscopy↗
DOE OSTI2020

High-Frequency Signature-Based Fault Detection for Future MV Distribution Grids: Preprint

Increased deployment of Distributed Energy Resources (DERs) and microgrids are significantly changing the operation of distribution grid. Increasing penetration of power electronics based DERs also raise several operational problems such as protection coordination issues, voltage raise, recloser synchronization, stability, and frequency control. Legacy systems are designed for unidirectional power flow. Bidirectional power flows, and varying short circuit levels are some of the major challenges in implementing these legacy protection schemes for future power grid with high penetration of power electronics based DERs. Inverter based DER’s can contribute to a maximum of 2 p.u. fault current. Interconnection standards might require even lower fault current contribution. If these protection related challenges are not addressed, it will result in limiting the penetration of DERs in distribution feeders. In this paper, the feasibility of high frequency signature generated by transients is evaluated to identify and locate faults in a distribution system. The paper will discuss the need for an accurate line modeling approach to accurately capture the high frequency signatures. These high frequency signatures are naturally occurring electromagnetic transients for events such as switching events in the network, faults events, etc. This is different than that implemented in transmission systems as the proposed approach utilizes advanced signal processing techniques to retrieve valuable information from the high frequency signatures generated during faults and does not just rely on time delay measurements between reflections of the high frequency signals. In the full paper, information of a modified IEEE distribution feeder test system to accurately model the high frequency signatures will be provided. The distribution lines will be modeled using universal line modeling (ULM) technique in an electromagnetic transients program (EMTP) modeling platform. Different test cases will be simulated and these test cases will include different fault types, multiple fault locations, capacitor bank switching, etc. The feeder system modeled for these simulations will also include power electronics based DERs. Additionally, experimental results demonstrating the high frequency signatures generated due to a transient event in a medium voltage (13.8 kV) distribution line will also be presented in the full paper. Furthermore, the analysis combined with simulation and experimental results in the full paper will help demonstrate the feasibility and efficacy of the proposed protection scheme. The developed protection scheme will not just help solve problems generated by bidirectional current flow, varying short-circuit current capacity, but also help in proliferation of DERs in distribution systems.

41 EE - Solar Energy Technologies Office (EE-4S)↗
DOE OSTI2021

Two-dimensional correlation analysis for x-ray photoelectron spectroscopy

Abstract X-ray photoelectron spectroscopy (XPS) measures the binding energy of core-level electrons, which are well-localised to specific atomic sites in a molecular system, providing valuable information on the local chemical environment. The technique relies on measuring the photoelectron spectrum upon x-ray photoionisation, and the resolution is often limited by the bandwidth of the ionising x-ray pulse. This is particularly problematic for time-resolved XPS, where the desired time resolution enforces a fundamental lower limit on the bandwidth of the x-ray source. In this work, we report a novel correlation analysis which exploits the correlation between the x-ray and photoelectron spectra to improve the resolution of XPS measurements. We show that with this correlation-based spectral-domain ghost imaging method we can achieve sub-bandwidth resolution in XPS measurements. This analysis method enables XPS for sources with large bandwidth or spectral jitter, previously considered unfeasible for XPS measurements.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Scorpius injector emittance measurements with solenoid scans

A classic scan solenoid can establish that the injector meets emittance requirements. Incorporating an aperture plate can validate predictions of much lower emittance. Measurements of beam parameters on the injector and ITS can inform predictions for the full LIA. Injector beam data is needed to tune the full LIA for initial turn-on and operation. Emittance measurements on the Scorpius injector are difficult because the beam is space-charge dominated. Emittance measurements on Scorpius injector and ITS will need large beam size to prevent overheating.

43 PARTICLE ACCELERATORS↗