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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Thermodynamic stability of a spin microemulsion in Rashba spin-orbit-coupled bosons

Recent finite-temperature numerical simulations have unveiled a quantum “spin” microemulsion analog, found by raising the temperature of a stripe supersolid phase in a Rashba spin-orbit coupled Bose gas. This microemulsion state is a highly correlated, isotropic normal fluid where atoms self-arrange based on their internal pseudospin into patterns that resemble bicontinuous microemulsions. This finding leaves several open questions regarding the broader accessibility of this phase in experiments. Here, we use equilibrium finite-temperature numerical simulations based on a coherent-state path integral representation to perform a computational investigation into the thermodynamic stability of the spin microemulsion state. Numerical simulations emphasize the requirement of a nearly, but not perfectly, isotropic spin-orbit coupling in order to achieve the microemulsion phase in cold-atom experiments. Moreover, the microemulsion state exists independent of miscibility of the pseudospin components and for a wide range of pseudospin population imbalance, suggesting a high degree of flexibility in choosing the atom and hyperfine states in an experimental realization. Lastly, we demonstrate this feasibility by mimicking a Rashba spin-orbit-coupled 87 Rb experiment in an isotropic harmonic trap, where we confirm the microemulsion's existence via its density profile and equilibrium quasimomentum distribution.

Complex Langevin dynamics↗
DOE OSTI2024

Web Based Beamline Control System (Bluesky Web) v0.1.0

Bluesky Web is a web based interface that provides beam line controls to the end user. It allows users to issue commands to various physical devices at a beam line end station like motors and cameras. It utilizes an open source Python library (Bluesky) as the controller. It uses Bluesky to also allow for running "plans" or a sequence of device operations that can be used when running an experiment. This program is different from other controls technologies because it is intended to be open source and can be accessed from a web browser, as opposed to other paid software that is run as a stand-alone application on a computer.

De Leon, Seij↗
DOE OSTI2024

Highly efficient visible and near-IR photon pair generation with thin-film lithium niobate

Efficient on-chip entangled photon pair generation at telecom wavelengths is an integral aspect of emerging quantum optical technologies, particularly for quantum communication and computing. However, moving to shorter wavelengths enables the use of more accessible silicon detector technology, and opens up applications in imaging and spectroscopy. Here, we present high brightness ((1.6 ± 0.3) × 10 9 pairs/s/mW/nm) visible–near-IR photon pair generation in a periodically poled lithium niobate nanophotonic waveguide. The degenerate spectrum of the photon pairs is centered at 811 nm with a bandwidth of 117 nm when pumped with a spectrally multimode laser diode. The measured on-chip source efficiency of (2.3 ± 0.5) × 10 11 pairs/s/mW is on par with source efficiencies at telecom wavelengths and is also orders of magnitude higher than the efficiencies of other visible sources implemented in bulk crystal or diffused waveguide-based technologies. Further improvements in the brightness and efficiencies are possible by pumping the device with a single-frequency laser, which would also shrink the pair bandwidth. These results represent the shortest wavelength of photon pairs generated in a nanophotonic waveguide reported to date by nearly an octave.

42 ENGINEERING↗
DOE OSTI2020

NREL CITIES Support (CRADA CRD-14-00558 Final Report)

The Technical University of Denmark has received a Grant from the Danish Council for Strategic Research for the project "CITIES - Centre for IT-Intelligent Energy Systems in Cities", a strategic research centre, which involves industrial partners and universities. The Alliance for Sustainable Energy, LLC will participate with DTU as an industrial partner in "CITIES" under this Cooperative Research and Development Agreement (CRADA). The Centre for IT based Intelligent Energy Systems in Cities (CITIES) Project is a Danish national research center focused on work in building short-term operational integrated energy system models that feed longer term plam1ing models, considering the spatio-temporal variations, interactions, dynamics and stochastics in the energy system, from production to consumption. CITIES will harness the extensive expertise and experience of its industrial and academic partners to conduct meaningful research with tangible outputs, including a roadmap to a fossil free future. Decision support tools will be developed to inform stakeholders of the impact of investment, control and policy measures and to identify further opportunities for energy system efficiency. Dissemination and transferring knowledge is a key value to this CRADA, and the use of results by Danish policymakers, industry and society is vital. All participants in the Centre for IT based Intelligent Energy Systems in Cities (CITIES) Project are therefore encouraged to use all means to communicate their findings to society. Wherever possible, and compatible with applicable intellectual property regulations, publications should be produced and disseminated under Open Science, Data, Source and Access principles.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Initial Testing of an In Situ Load Retention Aging Vessel

A thermal aging vessel instrumented with load cells was fabricated. The primary function of the vessel is to continuously monitor the in situ load retention of up to three compressed polymer coupons undergoing thermally accelerated aging under nitrogen. A secondary function is to enable gas sampling of the vessel headspace during thermal aging. Heating of the vessel is achieved using a custom heater jacket. To improve upon our conventional aging study methods which require periodic interruption of aging to perform load testing in an Instron machine at room temperature, this technology aims to automate/facilitate data acquisition/analysis, improve data quality, and enable uninterrupted compression of the polymer which represents the service condition. As an example case to assess functionality of the in situ vessel, the load retention of a siloxane elastomer material additively manufactured by direct-ink-writing (DIW) was measured at three different isothermal aging temperatures for ~1 month. Initial compression of the coupons while near the aging temperature was achieved by temporarily opening the heated vessel to access the interior chamber and manually tightening four nuts to drive the heated compression plate down onto the heated coupons. Initial testing demonstrated achievement of the primary load retention monitoring function. Unfortunately, the vessel leaked which prevented gas sampling; an active purge was used to maintain a nitrogen atmosphere. Welded or otherwise sealed joints, which could be implemented in a future design, would likely eliminate leak paths. To apply time-temperature superposition (TTS), a technique used to provide long-term prediction of the load retention from short-term isothermal data, the load retention needed to be calculated relative to the load at an estimated “equilibrium” time, after most of the transient viscoelastic physical relaxation occurred. The peak load immediately after compression could not be used as the load retention basis for two reasons: (1) age-related changes must be isolated from non-age-related physical relaxation before applying TTS and (2) the manual mechanism used to compress the specimens at the aging temperature was neither smooth nor repeatable which affected the peak load value. To better understand the effect of the mode of initial compression on the measured load, and possibly better estimate “equilibrium” physical relaxation times, systematic stress relaxation experiments were performed using an Instron machine with a thermal chamber. At a given temperature, the DIW polymer was compressed to a fixed strain in either a stepped or continuous manner at two different rates, then held at that strain for 24 hrs. The results indicated that, at a given temperature, the different stress relaxation curves appeared to converge to the same curve at some “equilibrium” time when the non-age-related physical relaxation was mostly complete. Though this observation suggests that the discontinuous manual compression employed by the vessel is feasible, a compression mechanism that is rapid, smooth, and repeatable would enhance its use.

36 MATERIALS SCIENCE↗
DOE OSTI2021

High Field Side Launch of RF Waves: A New Approach to Reactor Actuators

Launching radio frequency (RF) waves from the high field side (HFS) of a tokamak offers significant advantages over low field side (LFS) launch with respect to both wave physics and plasma material interactions (PMI). For lower hybrid (LH) waves, the higher magnetic field opens the window between wave accessibility and the condition for strong electron Landau damping, allowing LH waves from the HFS to penetrate into the core of a burning plasma, while waves launched from the LFS are restricted to the periphery of the plasma. The lower of waves absorbed at higher yields a higher current drive efficiency as well. In the ion cyclotron range of frequencies (ICRF), HFS launch allows for direct access to the mode conversion layer where mode converted waves absorb strongly on thermal electrons and ions, thus avoiding the generation of energetic minority ion tails. The absence of turbulent heat and particle fluxes on the HFS, particularly in double null configuration, makes it the ideal location to minimize PMI damage to the antenna structure. The quiescent SOL also eliminates the need to couple LH waves across a long distance to the separatrix, as the antenna can be located close to plasma without risking damage to the structure. Improved impurity screening on the HFS will help eliminate the long-standing issues of high Z impurity accumulation with ICRF.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

High Field Side Launch of Lower Hybrid Waves: A Scoping Study for ADX

Launching lower hybrid (LH) waves from the high field side (HFS) of a tokamak offers significant advantages over low field side (LFS) launch with respect to both wave physics and plasma material interactions (PMI). The higher magnetic field opens the window between wave accessibility and the condition for strong electron Landau damping, allowing LH waves from the HFS to penetrate into the core of a burning plasma, while waves launched from the LFS are restricted to the periphery of the plasma. The lower parallel refractive index (n) of waves launched from the HFS yields a higher current drive efficiency as well. The absence of turbulent heat and particle fluxes on the HFS, particularly in double null configuration, makes it the ideal location to minimize PMI damage to the antenna structure. The quiescent SOL also eliminates the need to couple LH waves across a long distance to the separatrix, as the antenna can be located close to plasma without risking damage to the structure.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1986

Pioneering the space frontier

The goals and plans of the program for exploration and development of the space frontier recommended by the National Commission on Space for the next 50 years are described. The topics discussed include civilian space goals for 21st-century America, low-cost access to the solar system, opening the space frontier, and American leadership on the space frontier. Papers are presented on advancing science; exploring, prospecting, and settling the solar system; space enterprise and building the technology base; and on an economical, phased approach. In addition, consideration is given to the aspects of conducting an effective science program, government policy and the private sector, international cooperation and competition, 21st-century America, and to what the recommended program will do.

Space Exploration↗
NASA NTRS1995

Satellite Situation Center data system for magnetospheric science planning

Critical problems in planning coordinated observation campaigns for magnetospheric science include the need to predict time intervals when one or more observing satellites or ground stations will be connected along magnetic field lines to other observation sites, or when such sites will be located within magnetospheric regions of common interest. The Satellite Situation Center (SSC) was created at the National Space Science Data Center (NSSDC) during the International Magnetospheric Study in the 1970s to address these problems. The SSC Data System has evolved since that era to support potentially complex queries by SSC staff and has now been opened to NASA Science Internet access via the NSSDC On-line Data Information System (NODIS). The SSC software, ephemeris data base, and access modes are described for the Version 2.1 release in 1993.

Aist-Sagara, L.↗
NASA NTRS2009

The Role of Flux Transfer Events in Solar Wind-Magnetosphere Coupling

Recent global MHD simulations of Flux Transfer Events (FTE's)[Dorelli and Bhattachar ee, JGR, 114, 2009] demonstrate that they are topologically complex flux ropes which extend large distances away from the subsolar magnetopause. Thus, FTE's represent a significant perturbation to the magnetopause magnetic field topology. Specifically, prior to the formation of the first FTE of the simulation, the dayside magnetopause has a relatively simple topology consisting of a single magnetic separator draping northward (even for southward IMF) over the dayside magnetopause (in a manner similar to the "overdraping" which occurs under northward IMF conditions). After the first FTE forms, however, the magnetopause becomes topologically more complex, consisting of multiple separators and braided flux domains. One consequence of this topological complexity is that open flux tubes have direct access to the magnetosphere near the subsolar region (such direct access is not possible during steady separator reconnection). Since the magnetopause topology affects the mapping of the solar wind electric field to the magnetosphere, an interesting question arises: What is the effect of FTE generation on the global magnetospheric convection pattern? In this talk, we address this question by exploring the differences between magnetospheric and ionospheric convection before and after the formation of the first FTE of the simulation.

Dorelli, John C.↗
NASA NTRS2010

Commercial Spacewalking: Designing an EVA Qualification Program for Space Tourism

In the near future, accessibility to space will be opened to anyone with the means and the desire to experience the weightlessness of microgravity, and to look out upon both the curvature of the Earth and the blackness of space, from the protected, shirt-sleeved environment of a commercial spacecraft. Initial forays will be short-duration, suborbital flights, but the experience and expertise of half a century of spaceflight will soon produce commercial vehicles capable of achieving low Earth orbit. Even with the commercial space industry still in its infancy, and manned orbital flight a number of years away, there is little doubt that there will one day be a feasible and viable market for those courageous enough to venture outside the vehicle and into the void, wearing nothing but a spacesuit, armed with nothing but preflight training. What that Extravehicular Activity (EVA) preflight training entails, however, is something that has yet to be defined. A number of significant factors will influence the composition of a commercial EVA training program, but a fundamental question remains: 'what minimum training guidelines must be met to ensure a safe and successful commercial spacewalk?' Utilizing the experience gained through the development of NASA's Skills program - designed to qualify NASA and International Partner astronauts for EVA aboard the International Space Station - this paper identifies the attributes and training objectives essential to the safe conduct of an EVA, and attempts to conceptually design a comprehensive training methodology meant to represent an acceptable qualification standard.

Gast, Matthew A.↗
NASA NTRS2011

Galactic Cosmic Ray Intensity Response to Interplanetary Coronal Mass Ejections/Magnetic Clouds in 1995-2009

We summarize the response of the galactic cosmic ray (CGR) intensity to the passage of the more than 300 interplanetary coronal mass ejections (ICMEs) and their associated shocks that passed the Earth during 1995-2009, a period that encompasses the whole of Solar Cycle 23. In approx.80% of cases, the GCR intensity decreased during the passage of these structures, i.e., a "Forbush decrease" occurred, while in approx.10% there was no significant change. In the remaining cases, the GCR intensity increased. Where there was an intensity decrease, minimum intensity was observed inside the ICME in approx.90% of these events. The observations confirm the role of both post-shock regions and ICMEs in the generation of these decreases, consistent with many previous studies, but contrary to the conclusion of Reames, Kahler, and Tylka (Astrophys. 1. Lett. 700, L199, 2009) who, from examining a subset of ICMEs with flux-rope-like magnetic fields (magnetic clouds) argued that these are "open structures" that allow free access of particles including GCRs to their interior. In fact, we find that magnetic clouds are more likely to participate in the deepest GCR decreases than ICMEs that are not magnetic clouds.

Richardson, I. G.↗
NASA NTRS2019

HDF5 Roadmap 2019-2020

In this talk we will give an overview of the new features of the upcoming HDF5 release 1.12.0, and outline the HDF5 roadmap for the next year. We will demonstrate new open source file drivers to access HDF5 files via Amazon Simple Storage Service (Amazon S3) and on Hadoop Distributed File system (HDFS). We will use this presentation to get feedback on the HDF5 roadmap from the ESDIS users and application developers.

Cloud↗
NASA NTRSDate not supplied

Space Robot Operating System (Space ROS)

Space Robot Operating System (Space ROS) is an open-source software framework for flight-quality robotic and autonomous space systems. It combines the benefits of open-source software and flight software best-practices into a single framework. Space ROS is predicated on ROS2 and is therefore reusable, modular and adoptable. As an open-source framework, it is accessible to the global space community. Space ROS is intended to be compliant with NASA flight software engineering practices in order to facilitate meeting mission and safety standards. Space ROS has fault management and real-time capabilities at its core.

Will Chambers↗
NASA NTRSDate not supplied

Openet: Applications of Satellite-Based Evapotranspiration Data for Water Resources Management in the Western United States

Advancing water security in overallocated river basins globally requires consistent and reproducible information on consumptive use of water that can anchor the development of data-driven solutions to the challenge of balancing water supply and demand. OpenET is a fully automated system for field-scale (30 m), satellite-based mapping of evapotranspiration (ET) at daily, monthly and annual timesteps. OpenET currently provides spatially contiguous data throughout the 23 westernmost states in the continental US, and includes both current information as well as multi-year timeseries of ET. The OpenET consortium has implemented an ensemble of satellite-based ET models (ALEXI/DisALEXI, eeMETRIC, PT-JPL, geeSEBAL, SIMS and SSEBop) on Google Earth Engine, which provides a shared computing platform for collaboration on processing of data from Landsat and other satellites, land cover and meteorological inputs, leading to increased consistency and accuracy across the ensemble of models. Earth Engine also facilitates hosting and distribution of data via open data collections and an application programming interface. We provide updates on the OpenET framework, open data services and data access tools, approach to geographic expansion, recent accuracy assessments, and describe how a user-driven design approach has facilitated successful applications of OpenET data for a wide range of water resource management activities. Applications to date include: use of ET data to improve quantification of ET and consumptive use in Oregon, Utah and the Upper Colorado River Basin; streamlining of water use reporting requirements in the California Delta; support for calculation of water budgets for the implementation of the Sustainable Groundwater Management Act in California; and integration into decision support tools for irrigation management. The use cases demonstrate how satellite-derived ET data that are easily accessed and seen as broadly accepted can accelerate adoption of innovative water management practices at scale, and support advances in the sustainability of water supplies. Uptake and use of data by the OpenET science community has also led to advances in our understanding of the impacts of landcover change, irrigation intensification and wildfire events on hydrology and the water security.

Applications↗
DOE OSTI2021

Ion beam mill etch depth monitoring with nanometer-scale resolution

A method for measuring conductance of a material real-time during etching/milling includes providing a fixture having a socket for receiving the material. The socket is attached to a printed circuit board (PCB) mounted on one side of a plate that has at least one opening for providing ion beam access to the material sample. Conductive probes extend from the other side of the PCB to contact and span a target area of the material. A measurement circuit in electrical communication with the probes measures the voltage produced when a current is applied across the material sample to measure changes in electrical properties of the sample over time.

Cybart, Shane A.↗
DOE OSTI2024

Geospatial Data Platform for All

Spatiotemporal data has evolved in scale due to augmented use in cross-domain applications. Simultaneously, there is substantial growth in the availability of Geographic Information Systems (GIS) data provided by the United States Geological Survey (USGS) along with other federal, state, county, or local agencies through open-data portals and public access APIs. However, data availability does not equate with accessibility. Large-scale analyses and applications require robust, performant data management with co-location of data storage and computing. The insufficiency of data management infrastructure compels researchers to adopt ad hoc project- specific GIS data storage solutions (e.g., copying data to High-Performance computer file systems). As an ad hoc storage strategy does not scale, it hampers cross-domain analyses causing difficulty in data reuse and utilizing existing code bases. Furthermore, GIS data is complex and requires expertise to analyze and manipulate due to its intricate data structures and data-specific projection transformations. Despite the challenges, we recognize that derived GIS data products, e.g., satellite or LIDAR-based images, can be used in downstream applications such as AI by domain, but non-GIS experts. To address the data needs and overcome the challenges, we are working towards a GIS Data Platform focused on efficient data storage, data discovery and access, and an API to enable common workflows. We propose a knowledge-graph (KG) approach for data discovery, whereby datasets are semantically linked to higher- level constructs such as projects and research areas. The semantic data links enable researchers to explore datasets in a top-down approach by specifying relevant and meaningful terms (assists in finding hidden data). An advantage is that the nodes and edges in a knowledge graph create built-in semantic documentation. Deeper spatiotemporal connections between data sources can be encoded via Graph Neural Networks (GNN) (Zhang et al., 2021). The KG approach can be extended to integrate the data itself in a Virtual KG (VKG). Our work will derive inspiration from large-scale VKG efforts that have been undertaken or are currently underway as part of the OpenStreetMap project (Ding et al., 2021). For DOE Data Days, we share the proposed geospatial data platform hybrid (cloud/on-prem) architecture, our work-to-date on storing, retrieving, and transforming LiDAR and raster data relevant to two important NREL use-cases, including the Renewable Energy Potential (reV) Model, and present our proposal for a KG based data discovery engine.

data platform↗
DOE OSTI2024

Navigating Urban Mobility: Evaluating Infrastructure Strategies for Enhanced Energy-Efficient Access for Micromobility

Cities and communities continue to expand pedestrian and bicycle infrastructure as part of their sustainable mobility and post-pandemic recovery plans. However, the emergence of micro-mobility (e.g., electric bicycles) has created new challenges for urban transport planning. As the popularity of micro-mobility modes has grown, so have safety concerns due to rising injuries, thus challenging many cities to come up with regulatory measures that enable efficient access while minimizing negative impacts from micro-mobility. Leveraging the Open-Source Tool (Mobility Energy Productivity metric), powered by an open-source dataset (OpenStreetMap), and enhanced through the incorporation of perceived discomfort (level-of-traffic stress), this research study focuses on evaluating the accessibility implications of infrastructure planning and regulatory measures for micro-mobility. Five scenarios pertaining to level of traffic stress, sidewalk access, traffic calming, and bike lane coverage were tested in the Denver-Aurora region in Colorado. Maximum improvements in energy-efficient access are realized when allowing sidewalks for micro-mobility use. Cities and planning agencies could leverage this information to assess sidewalk use policies for micro-mobility, while ensuring pedestrian safety and ADA access. Results indicate that expansion of bicycle lane coverage yields 11% accessibility benefits for micro-mobility compared to implementing traffic calming measures yielding 3% accessibility improvements. Further, it was observed most of the population in the Denver-Aurora region is experiencing lower accessibility in-part due to presence of a high-stress connections in the network. Although not generalizable, the use of open-source data and access calculation methodology, make this analysis reproducible and transferable to other locations.

ADVANCED PROPULSION SYSTEMS↗