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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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Nalu SpinnerLidar Model [Slides]
Develop, verify, and document model capabilities sufficient for comparing field wake measurements from SWiFT with synthetic lidar wake measurements from Nalu-Wind (hereafter referred to as `Nalu').
Cyber Conservative Operations
In an era of increasingly sophisticated and pervasive cyber threats, robust cyber resilience strategies are more critical than ever. This paper introduces the concept of Cyber Conservative Operations, a proactive approach designed to assist critical infrastructure owners and operators in managing risk and maintaining resilience in the face of imminent, yet not occurring, cyber events. By leveraging the principles of Cyber-Informed Engineering (CIE) and the energy sector’s practice of conservative operations, Cyber Conservative Operations offer a framework for planning and executing coordinated active defense and resilience-oriented actions ahead of cyber events. This approach aims to minimize the consequences of digitally-enabled hazards and ensure swift recovery from anticipated cyber threats. Cyber Conservative Operations enhance the ability of owners and operators to execute pre-planned defense and resilience actions, thereby reducing the impact of digitally-enabled hazards. These operations are crucial for addressing impacts that cannot be precisely quantified or forecasted and for preparing organizations for rapid recovery from imminent digital threats. The paper begins with a discussion of conservative operations as applied to the bulk power system (BPS), a current mechanism allowing BPS entities to enact defensive operating plans to mitigate impending grid unreliability. Building on this model, we present a concept for implementing cyber conservative operations at asset owner facilities. The paper concludes with two case studies of cyber conservative operations drawn from high-profile cyber events, illustrating the practical application and benefits of this proactive approach.
Flexible Perovskite-Perovskite PV for Mobile Power Applications (CRADA Final Report)
NLR and Swift Solar, under a Technology Commercialization Fund award, will cooperate to incorporate NLR's new recombination layer into current device architectures, optimize the new wide bandgap material and utilize it in tandem devices, and translate all lab scale work on rigid substrates to flexible substrates.
An equipotential model for auroral arcs - The theory of two-dimensional laminar electrostatic shocks
The two-dimensional current-driven shock theory of Swift (1976) is reformulated in a way that removes previous restrictions on the shock thickness in relation to an ion gyrodiameter and also makes it possible to include effects of finite gyrational energy of the ions. The theory is applied to a shock model consisting of cold streaming electrons of magnetospheric origin and streaming ions of ionospheric origin, and it is shown that shock widths will be slightly less than the gyrodiameter of an ion whose energy is equal to the maximum potential difference across the shock. It is also shown that ions in passing through the shock may gain gyrational energy on the order of 10% of the parallel and the E x B energy gain. The theory also requires that the electron beam flux be largest on field lines where the precipitating electron experiences the largest energy gain.
A note on the nature of the distant geomagnetic tail magnetopause and boundary layer
In the present comparison of recent plasma and magnetic field measurements of the distant geomagnetic tail magnetopause and boundary layer with numerical simulation results for an 'open' boundary, most aspects revealed are consistent with simulation results for conditions in which the normal magnetic field component at the magnetopause is generally small. On the basis of these results, the simulations of Swift and Lee (1982, 1983) are judged to be able to furnish a theoretical basis for understanding many aspects of the distant geomagnetic tail magnetopause and mantle boundary layer.
Ancient Chinese Observations and Modern Cometary Models
Ancient astronomical observations, primarily by Chinese, represent the only data source for discerning the long-term behavior of comets. These sky watchers produced astrological forecasts for their emperors. The comets Halley, Swift-Tuttle, and Tempel-Tuttle have been observed for 2000 years. Records of the Leonid meteor showers, starting from A.D.902, are used to guide predictions for the 1998-1999 reoccurrence.
Lunar Meteoroid Impact Observations and the Flux of Kilogram-sized Meteoroids
Lunar impact monitoring provides useful information about the flux of meteoroids in the hundreds of grams to kilograms size range. The large collecting area of the night side of the lunar disk, approximately 3.8 10(exp 6)sq km in our camera field-of-view, provides statistically significant counts of the meteoroids striking the lunar surface. Over 200 lunar impacts have been observed by our program in roughly 4 years. Photometric calibration of the flashes observed in the first 3 years along with the luminous efficiency determined using meteor showers and hypervelocity impact tests (Bellot Rubio et al. 2000; Ortiz et al. 2006; Moser et al. 2010; Swift et al. 2010) provide their impact kinetic energies. The asymmetry in the flux on the evening and morning hemispheres of the Moon is compared with sporadic and shower sources to determine their most likely origin. These measurements are consistent with other observations of large meteoroid fluxes.
Goddard's Astrophysics Science Divsion Annual Report 2014
The Astrophysics Science Division (ASD, Code 660) is one of the world's largest and most diverse astronomical organizations. Space flight missions are conceived, built and launched to observe the entire range of the electromagnetic spectrum, from gamma rays to centimeter waves. In addition, experiments are flown to gather data on high-energy cosmic rays, and plans are being made to detect gravitational radiation from space-borne missions. To enable these missions, we have vigorous programs of instrument and detector development. Division scientists also carry out preparatory theoretical work and subsequent data analysis and modeling. In addition to space flight missions, we have a vibrant suborbital program with numerous sounding rocket and balloon payloads in development or operation. The ASD is organized into five labs: the Astroparticle Physics Lab, the X-ray Astrophysics Lab, the Gravitational Astrophysics Lab, the Observational Cosmology Lab, and the Exoplanets and Stellar Astrophysics Lab. The High Energy Astrophysics Science Archive Research Center (HEASARC) is an Office at the Division level. Approximately 400 scientists and engineers work in ASD. Of these, 80 are civil servant scientists, while the rest are resident university-based scientists, contractors, postdoctoral fellows, graduate students, and administrative staff. We currently operate the Swift Explorer mission and the Fermi Gamma-ray Space Telescope. In addition, we provide data archiving and operational support for the XMM mission (jointly with ESA) and the Suzaku mission (with JAXA). We are also a partner with Caltech on the NuSTAR mission. The Hubble Space Telescope Project is headquartered at Goddard, and ASD provides Project Scientists to oversee operations at the Space Telescope Science Institute. Projects in development include the Neutron Interior Composition Explorer (NICER) mission, an X-ray timing experiment for the International Space Station; the Transiting Exoplanet Sky Survey (TESS) Explorer mission, in collaboration with MIT (Ricker, PI); the Soft X-ray Spectrometer (SXS) for the Astro-H mission in collaboration with JAXA, and the James Webb Space Telescope (JWST). The Wide-Field Infrared Survey Telescope (WFIRST), the highest ranked mission in the 2010 decadal survey, is in a pre-phase A study, and we are supplying study scientists for that mission.
Key Accomplishments & Results: Sustainable Wastewater Infrastructure of the Future
This fact sheet summarizes the key accomplishments and results from DOE's Better Buildings Sustainable Wastewater Infrastructure of the Future (SWIFt) Accelerator. The Accelerator was a 3-year effort between DOE and state and local jurisdictions to promote energy data management practices in wastewater operations in an effort to increase energy efficiency in wastewater facilities around the country. Accelerator participants shared implementation plans, and DOE combined the results into a final toolkit.
Taming Metal–Solid Electrolyte Interface Instability via Metal Strain Hardening
Abstract Solid-state lithium metal batteries have emerged as a promising technology for electric vehicles due to their high specific energy and safety potential. Obtaining intimate contact between Li and electrolyte during cell fabrication, however, remains challenging. Adequate fabrication pressure is required to promote close contact, but this pressure can cause Li deformation and penetration into the electrolyte, resulting in poor battery performance. Here, a strategy for addressing this problem is presented by incorporating 3 at% Mg into Li. Unlike pure Li which obeys the Voce hardening law and allows unconstrained deformation, Li–Mg alloy follows the Swift hardening law and strengthens with strain under compression stress. Because of the constrained deformation of Li–Mg, intimate contact with solid electrolytes is possible even at high fabrication pressure (50–65 MPa), resulting in high critical current densities. These findings underscore the importance of understanding Li metal deformation properties to improve solid-state battery performance.
Current challenges in hydrate‐based desalination: Kinetic and thermodynamic perspective
Abstract Water scarcity is becoming a severe problem worldwide due to inadequate freshwater resources and swift population growth. Seawater desalination is one of the vital approaches to meet the demand for freshwater. However, energy and associated costs with conventional seawater desalination techniques are incentivizing non‐conventional water desalination processes. Water desalination using gas hydrates formation is one of the emerging non‐conventional processes. In this perspective article, recent advances in hydrate‐based seawater desalination (HBSD) have been critically analyzed to outline a future path towards a clean and efficient hydrate‐based desalination process. It provides a detailed comparison of various processes developed over decades, and measured desalination efficiencies with their process details. Moreover, the current challenges, limitations, and future perspectives of hydrate‐based desalination are also discussed. The study also recapitulates the thermodynamics and kinetics aspects of the hydrate‐based desalination process. In addition, various factors controlling the desalination efficiencies, such as control of the separation of hydrate crystals, salt deposition on hydrate particles, and hydrate morphology, were thoroughly investigated with their proposed process designs. The kinetics of hydrate formation is also assessed, with the possibility of a zero‐induction regime and its consequent impact on hydrate morphology. The current capabilities of the thermodynamics models (Gibbs energy minimization + electrolyte equation of state) were discussed using various commercially available software. Additionally, the role of hydrate promotors is also discussed, which can reduce the higher cost associated with the hydrate‐based desalination process.
Rates of Ligand Exchange around the Bis-Oxalato Complex [NpO 2 (C 2 O 4 ) 2 ] 3- Measured by Using Multinuclear NMR Spectroscopy under Neutral to Semi-Alkaline Conditions [Rates of ligand exchange around the bis-oxalato complex NpO2(C2O4)23- measured using multinuclear NMR at neutral to semi-alkaline conditions]
The kinetics of ligand exchange between the free oxalate ion, C 2 O 4 2- , and the bis-oxalato Np V complex, [NpO 2 (C 2 O 4 ) 2 ] 3- , in aqueous solution are reported by using 13 C and 17 O NMR spectroscopy methods. Rates of exchange were measured in the pH regime of 6.5–9.0, at which speciation is shown to be suitably simple. Because the neptunium(V) complex is paramagnetic, the rates of ligand exchange were estimated by following the width of the 13 C and 17 O signals assigned to the free oxalate ion in solution and by applying the Swift–Connick method for measuring rates of exchange. A set of experiments were conducted in which pH and total oxalate concentration were varied, and the linear dependence of the rate on these parameters was demonstrated. Variable-temperature NMR spectroscopy was also performed to measure activation parameters of complexation. Finally, at pH<8.0, ΔH ≠ =16.9 ±4.9 kJ mol -1 and ΔS≠=-116.3 ±17.1kJ mol -1 K -1 , whereas at pH>8.0 there is almost no dependence on temperature, which is interpreted to indicate that hydrolysis is coupled to ligand exchange under these conditions.
Implementation and Validation of a Generalized Actuator Disk Parameterization for Wind Turbine Simulations Within the FastEddy Model
ABSTRACT Fast and accurate large‐eddy simulation (LES) of the atmospheric boundary layer plays a crucial role in advancing wind energy research. Long‐duration wind farm studies at turbine‐resolving scales have become increasingly important to understand the intricate interactions between large wind farms and the atmospheric boundary layer. However, the prohibitive computational cost of these turbulence‐ and turbine‐resolving simulations has precluded such modeling to be exercised on a regular basis. To that end, we implement and validate the generalized actuator disk (GAD) model in the computationally efficient, graphics processing unit (GPU)–resident, LES model FastEddy. We perform single‐turbine simulations under three atmospheric stabilities (neutral, unstable, and stable) and compare them against observations from the Scaled Wind Farm Technology (SWiFT) facility and other LES codes from the recent Wakebench turbine wake model benchmark. Our idealized LES results agree well with observed wake velocity deficit and downstream recovery across stability regimes. Turbine response in terms of rotational speed, generated power, torque, and thrust coefficient are well predicted across stability regimes and are consistent with the LES results from the benchmark. The FastEddy simulations are found to be at least two orders of magnitude more efficient than the traditional CPU‐based LES models, opening the door for realistic LES simulations of full wind plants as a viable standard practice.
A Review on Micro- and Nanoscratching/Tribology at High Temperatures: Instrumentation and Experimentation
High-temperature micro-/nanomechanics has attracted much interest over the last decade, primarily because of the urgent need to understand the mechanical and tribological properties of advanced engineering materials at micro-/nanoscale and the underlying physics controlling such properties at operationally relevant conditions. Recent years have subsequently witnessed the swift growth and development of new high-temperature micro- and nanoscratching/tribology instruments. Here, we present an overview of fundamental principles and developments in these instruments, discuss pertinent findings on the topic in detail, and outline current challenges and promising future directions in the field.
Microstructure and Work Hardening Behavior of Micro-plasma Arc Welded AISI 316L Sheet Joint
The aim of this research is to investigate the microstructural changes and work hardening behavior of AISI 316L 0.5-mm-thick sheet due to micro-plasma arc welding. AISI 316L similar sheets were welded in single-pass square butt joint configuration. The microstructure in the fusion zone typically contains a variety of complex δ-ferrite-austenitic structure, which significantly increased hardness value compared to the base material because of rapid solidification of the weld pool. Systematic tensile test was performed to investigate strain rate sensitivity of the welded joint under quasi-static loading conditions. The multistage work hardening behavior was determined by Kocks–Mecking (K–M) model and differential Crussard–Jaoul analysis. In both the cases, stage III work hardening behavior and stage IV work hardening behavior were observed. The stress–strain curves of welded specimen at different strain rates were analyzed in terms of Hollomon, Ludwik and Swift equations to determine work hardening exponent values. The welded joints were ruptured in the transition zone of heat affected and fusion zones. The fractographic observation exhibited variation in dimple and void density over strain rate from 0.0001 to 0.0015 s{sup −1}.
Integrating Carbon Nanomaterials with Metals for Bio-sensing Applications
Age structure in most developed countries is changing fast as the average lifespan is increasing significantly, calling for solutions to provide improved treatments for age-related neurological diseases and disorders. In order to address these problems, a reliable way of recording information about neurotransmitters from in vitro and in vivo applications is needed to better understand neurological diseases and disorders as well as currently used treatments. Likewise, recent developments in medicine, especially with the opioid crisis, are demanding a swift move to personalized medicine to administer patient needs rather than population-wide averages. In order to enable the so-called personalized medicine, it is necessary to be able to do measurements in vivo and in real time. These actions require sensitive and selective detection of different analytes from very demanding environments. Current state-of-the-art materials are unable to provide sensitive and selective detection of neurotransmitters as well as the required time resolution needed for drug molecules at a reasonable cost. To meet these challenges, we have utilized different metals to grow carbon nanomaterials and applied them for sensing applications showing that there are clear differences in their electrochemical properties based on the selected catalyst metal. Additionally, we have combined atomistic simulations to support optimizing materials for experiments and to gain further understanding of the atomistic level reactions between different analytes and the sensor surface. With carbon nanostructures grown from Ni and Al + Co + Fe hybrid, we can detect dopamine, ascorbic acid, and uric acid simultaneously. On the other hand, nanostructures grown from platinum provide a feasible platform for detection of H 2 O 2 making them suitable candidates for enzymatic biosensors for detection of glutamate, for example. Tetrahedral amorphous carbon electrodes have an ability to detect morphine, paracetamol, tramadol, and O-desmethyltramadol. With carbon nanomaterial-based sensors, it is possible to reach metal-like properties in sensing applications using only a fraction of the metal as seed for the material growth. We have also seen that by using nanodiamonds as growth catalyst for carbon nanofibers, it is not possible to detect dopamine and ascorbic acid simultaneously, although the morphology of the resulting nanofibers is similar to the ones grown using Ni. This further indicates the importance of the metal selection for specific applications. However, Ni as a continuous layer or as separate islands does not provide adequate performance. Thus, it appears that metal nanoparticles combined with fiber-like morphology are needed for optimized sensor performance for neurotransmitter detection. This opens up a new research approach of application-specific nanomaterials, where carefully selected metals are integrated with carbon nanomaterials to match the needs of the sensing application in question.
Operation and Performance of a Mass-Selective Cryogenic Linear Ion Trap
We report on the performance of a cryogenic 2D linear ion trap (cryoLIT) that is shown to be mass-selective in the temperature range of 17–295 K. As the cryoLIT is cooled, the ejection voltages during the mass instability scan decrease, which results in an effective mass shift to lower m/z relative to room temperature. This is attributed to a decrease in trap radius caused by thermal contraction. Additionally, the cryoLIT generates reproducible mass spectra from day-to-day, and is capable of performing stored waveform inverse Fourier transform (SWIFT) mass isolation of fragile N{sub 2}-tagged ions for the purpose of background-free infrared dissociation spectroscopy. .