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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 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

ETM: Upper Class E Traffic Management

The FAA, along with input from the National Aeronautics and Space Administration (NASA) and industry partners, published an initial Concept of Operations (ConOps) for Upper Class E Traffic Management (ETM). To support the next iteration of the ConOps, NASA Ames Research Center has been investigating several technologies and operating principles that will help enable industry in the system development of a cooperative operating environment. Following in the footsteps of the established Unmanned Aircraft Systems Traffic Management (UTM) concept, ETM will utilize some of the basic system architecture and the community-based theories of cooperation and coordination. The main considerations for ETM as compared to UTM, are the diversity of the vehicle types with varying speed and maneuverability capabilities, the severe stratospheric atmosphere conditions, the potential longevity of the missions, and the assorted operating modes (e.g., transit, loitering, or hovering). TM oriented technologies and proposed operating principles are being tested and assessed in a collaborative evaluation of an initial ETM system in spring of 2024. These slides will be presented to a group of stratospheric operators, informing them on some past work and the next steps in the ETM research.

Upper Class-E Traffic Management (ETM)↗
NASA NTRSDate not supplied

Initial Analysis of Digitally Enabled Cooperative Operations in Class D Terminal Airspace

The primary contribution of this paper is an initial analysis of integrating digitally enabled cooperative operations (or digital operations for short) with Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) operations in the terminal airspace around a Class D airport, specifically around Fort Worth Alliance airport (KAFW). Enabled by connected digital technologies and automated information exchange, digital operations as envisioned would utilize cooperative practices and operator-responsible separation to ensure safety. In the present study, three conflict management configurations for digital operations were analyzed: 1) centralized with a single instance of a conflict management service to model a scenario with only one fleet operator conducting digital operations or all fleet operators utilizing the same service, 2) federated with two different instances to model a scenario with two different fleet operators conducting digital operations, and 3) fully distributed with a different instance for each digital operation. In simulations in which recorded tracks for VFR and IFR operations were played back and digital operations were modeled that would nominally arrive at KAFW once every 20 minutes (given no conflict resolution maneuvers), there were one or fewer losses of separation (LOS) across the three conflict management configurations. The same result was seen in simulations in which digital operations would nominally arrive at KAFW once every 10 minutes. However, in simulations in which digital operations would nominally arrive at KAFW once every 5 minutes, the number of LOS ranged between six and ten. This highlights the need for follow-on research to investigate the extent to which additional capabilities for digital operations, such as complexity management and/or flow organization, may be needed.

digitally enabled cooperative operations, digital ↗
NASA NTRSDate not supplied

Initial Analysis of Digitally Enabled Cooperative Operations in Class D Terminal Airspace

The primary contribution of this paper is an initial analysis of integrating digitally enabled cooperative operations (or digital operations for short) with Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) operations in the terminal airspace around a Class D airport, specifically around Fort Worth Alliance airport (KAFW). Enabled by connected digital technologies and automated information exchange, digital operations as envisioned would utilize cooperative practices and operator-responsible separation to ensure safety. In the present study, three conflict management configurations for digital operations were analyzed: 1) centralized with a single instance of a conflict management service to model a scenario with only one fleet operator conducting digital operations or all fleet operators utilizing the same service, 2) federated with two different instances to model a scenario with two different fleet operators conducting digital operations, and 3) fully distributed with a different instance for each digital operation. In simulations in which recorded tracks for VFR and IFR operations were played back and digital operations were modeled that would nominally arrive at KAFW once every 20 minutes (given no conflict resolution maneuvers), there were one or fewer losses of separation (LOS) across the three conflict management configurations. The same result was seen in simulations in which digital operations would nominally arrive at KAFW once every 10 minutes. However, in simulations in which digital operations would nominally arrive at KAFW once every 5 minutes, the number of LOS ranged between six and ten. This highlights the need for follow-on research to investigate the extent to which additional capabilities for digital operations, such as complexity management and/or flow organization, may be needed.

digitally enabled cooperative operations↗
NASA NTRSDate not supplied

NAS Exploratory Concepts & Technologies (NExCT) Upper Class E Traffic Management (ETM) Collaborative Evaluation #1 (CE-1)

NASA, in partnership with AeroVironment and Aerostar, recently demonstrated a first-of-its-kind air traffic management concept that could pave the way for aircraft to safely operate at higher altitudes. This work seeks to open the door for increased internet coverage, improved disaster response, expanded scientific missions, and even supersonic flight. The concept is referred to as an Upper-Class E traffic management, or ETM. NASA and its partners have developed an ETM traffic management system that allows aircraft to autonomously share location and flight plans, enabling aircraft to stay safely separated. This concept was demonstrated during the recent traffic management simulation in the Airspace Operations Laboratory at Ames, data from multiple air vehicles was displayed across dozens of traffic control monitors and shared with partner computers off site. The study details and the initial results are presented at a regular, informal ETM industry meetings held virtually.

Upper Class E Traffic Management (ETM)↗
DOE OSTI2011

Measurement of the branching fraction for $\tau\to\eta K\nu_\tau$ and a search for second-class currents in $\tau\to\eta\pi\nu_\tau$ with $\eta\to\pi^ \pi^-\pi0$

The authors report on analyses of tau lepton decays {tau}{sup -} {yields} {eta}K{sup -}{nu}{sub {tau}} and {tau}{sup -} {yields} {eta}{pi}{sup -}{nu}{sub {tau}}, with {eta} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0}, using 470 fb{sup -1} of data from the BABAR experiment at PEP-II, collected at center-of-mass energies at and near the {Upsilon}(4S) resonance. They measure the branching fraction for the {tau}{sup -} {yields} {eta}K{sup -}{nu}{sub {tau}} decay mode, {Beta}({tau}{sup -} {yields} {eta}K{sup -}{nu}{sub {tau}}) = (1.42 {+-} 0.11(stat) {+-} 0.07(syst)) x 10{sup -4}, and report a 95% confidence level upper limit for the second-class current process {tau}{sup -} {yields} {eta}{pi}{sup -}{nu}{sub {tau}}, {Beta}({tau}{sup -} {yields} {eta}{pi}{sup -}{nu}{sub {tau}}) < 9.9 x 10{sup -5}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Measurement of the Tau- to F1(1285) Pi- Nu/Tau Branching Fraction And a Search for Second-Class Currents in Tau to Eta-Prime(958) Pi- Nu/Tau

The {tau}{sup -} {yields} {eta}{pi}{sup -}{pi}+{pi}{sup -}{nu}{tau} decay with the {eta} {yields} {gamma}{gamma} mode is studied using 384 fb{sup -1} of data collected by the BaBar detector. The branching fraction is measured to be (1.60 {+-} 0.05 {+-} 0.11) x 10{sup -4}. It is found that {tau}{sup -} {yields} f1(1285){pi}{sup -}{nu}{tau} {yields} {eta}{pi}{sup -}{pi}+{pi}{sup -}{nu}{tau} is the dominant decay mode with a branching fraction of (1.11 {+-} 0.06 {+-} 0.05) x 10{sup -4}. The first error is statistical and the second systematic. In addition, a 90% confidence level upper limit on the branching fraction of the {tau}{sup -} {yields} {eta}{prime}(958){pi}{sup -}{nu}{tau} decay is measured to be 7.2 x 10{sup -6}. This last decay proceeds through a second-class current and is expected to be forbidden in the limit of isospin symmetry.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Evaluation of proposed Section III Division 5 Class B rules: Piping example problem

Evaluation of proposed Section III Division 5 Class B rules: Piping example problem to be presented include Z pipe geometry and model problem statement, Z pipe loads and design inputs problem statement, Primary Stress Limit overview, Primary stress limit pseudo yield stress calculation, Primary stress limited factored load procedure, Strain limit evaluation composite load cycle, Strain limit evaluation pseudo yield stress, Strain limit evaluation strain limit criteria and ratcheting check, Creep fatigue damage evaluation overview, Creep fatigue damage evaluation alternating stress calculations, Creep fatigue damage evaluation lower bound stress, Creep fatigue damage evaluation stress relaxation history, Creep fatigue damage evaluation damage fractions, and Recommendations to consider for Z-pipe problem.

42 ENGINEERING↗
DOE OSTI2016

A new class of renewable thermoplastics with extraordinary performance from nanostructured lignin-elastomers

In this study, a new class of thermoplastic elastomers has been created by introducing nanoscale-dispersed lignin (a biomass-derived phenolic oligomer) into nitrile rubber. Temperature-induced controlled miscibility between the lignin and the rubber during high shear melt-phase synthesis allows tuning the material s morphology and performance. The sustainable product has unprecedented yield stress (15–45 MPa), strain hardens at large deformation, and has outstanding recyclability. The multiphase polymers developed from an equal-mass mixture of a melt-stable lignin fraction and nitrile rubber with optimal acrylonitrile content, using the method described here, show 5–100 nm lignin lamellae with a high-modulus rubbery interphase. Molded or printed elastomeric products prepared from the lignin-nitrile material offer an additional revenue stream to pulping mills and biorefineries. Research was sponsored by the Technology Innovation Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. TEM (J.C. and C.D.T.) and SAXS (J.K.K.) experiments were conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

36 MATERIALS SCIENCE↗
DOE OSTI2024

A Class of Sodium Transition-Metal Sulfide Cathodes With Anion Redox

Sodium-ion batteries (SIBs) are entering commercial relevance as a sustainable and low-cost alternative to lithium-ion batteries. Improving the energy density of SIBs is critical to enable their widespread adoption. Here, in this work, a new class of cathode materials Na 6 M S 4 ( M = Co, Mn, Fe, and Zn) that exhibit high charge-storage capacity is reported. Using Na 6 CoS 4 as a prototypical example, a six-electron conversion reaction dominated by anion redox is observed, confirmed through various electrochemical and spectroscopic techniques. After the initial cycle, Na 6 CoS 4 delivers a high capacity of 392 mA h g -1 with a long lifespan of over 500 cycles. The reaction involves, initially, the transformation of crystalline Na 6 CoS 4 to a nearly amorphous structure consisting of mainly CoS and sulfur nanoparticles, which then reversibly cycles between nearly amorphous a-CoS/S and a-Na 6 CoS 4 . Such anion-redox-driven conversion-type cathodes hold the potential to enable energy-dense, stable SIBs.

25 ENERGY STORAGE↗
DOE OSTI2018

Design of the First‐in‐Class, Highly Potent Irreversible Inhibitor Targeting the Menin‐MLL Protein–Protein Interaction

Abstract The structure‐based design of M‐525 as the first‐in‐class, highly potent, irreversible small‐molecule inhibitor of the menin‐MLL interaction is presented. M‐525 targets cellular menin protein at sub‐nanomolar concentrations and achieves low nanomolar potencies in cell growth inhibition and in the suppression of MLL‐regulated gene expression in MLL leukemia cells. M‐525 demonstrates high cellular specificity over non‐MLL leukemia cells and is more than 30 times more potent than its corresponding reversible inhibitors. Mass spectrometric analysis and co‐crystal structure of M‐525 in complex with menin firmly establish its mode of action. A single administration of M‐525 effectively suppresses MLL‐regulated gene expression in tumor tissue. An efficient procedure was developed to synthesize M‐525. This study demonstrates that irreversible inhibition of menin may be a promising therapeutic strategy for MLL leukemia.

Xu, Shilin↗
DOE OSTI2024

A New Class of Oxyhalide Solid Electrolytes NaNbCl 6‐2x O x for Solid‐state Sodium Batteries

Abstract Sodium‐based batteries are gaining momentum due to the abundance and lower cost of sodium compared to lithium. Solid‐state sodium batteries can also provide further safety advantages. However, sodium‐based solid‐state electrolytes (SSEs) that meet all the rigorous requirements, such as high ionic conductivity, oxidative stability with the cathode, and ease of processability, are lacking. We present here a new class of sodium‐based oxyhalide electrolytes NaNbCl 6‐2x O x with a facile mechanochemical synthesis. The oxyhalide NaNbCl 4 O exhibits close to two orders of magnitude higher ambient‐temperature sodium‐ion conductivity (1.03×10 −4 S cm −1 ) compared to the halide counterpart NaNbCl 6 (3×10 −6 S cm −1 ). Structural motifs unique to the oxygen content in NaNbCl 6‐2x O x are identified with 23 Na and 93 Nb magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and x‐ray diffraction (XRD). Solid‐state sodium batteries assembled with NaNbCl 4 O electrolyte and the cobalt‐ and nickel‐free layered Na 0.70 Fe 0.3 Mn 0.65 Al 0.05 O 2 cathode exhibit a maximum discharge capacity of 155 mAh g −1 with good cycle life at ambient temperature.

Kmiec, Steven↗
DOE OSTI2017

Design of the First-in-Class, Highly Potent Irreversible Inhibitor Targeting the Menin-MLL Protein–Protein Interaction

The structure-based design of M-525 as the first-in-class, highly potent, irreversible small-molecule inhibitor of the menin-MLL interaction is presented. M-525 targets cellular menin protein at sub-nanomolar concentrations and achieves low nanomolar potencies in cell growth inhibition and in the suppression of MLL-regulated gene expression in MLL leukemia cells. M-525 demonstrates high cellular specificity over non-MLL leukemia cells and is more than 30 times more potent than its corresponding reversible inhibitors. Mass spectrometric analysis and co-crystal structure of M-525 in complex with menin firmly establish its mode of action. A single administration of M-525 effectively suppresses MLL-regulated gene expression in tumor tissue. An efficient procedure was developed to synthesize M-525. This study demonstrates that irreversible inhibition of menin may be a promising therapeutic strategy for MLL leukemia.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

A New Class of Oxyhalide Solid Electrolytes NaNbCl 6‐2x O x for Solid‐state Sodium Batteries

Abstract Sodium‐based batteries are gaining momentum due to the abundance and lower cost of sodium compared to lithium. Solid‐state sodium batteries can also provide further safety advantages. However, sodium‐based solid‐state electrolytes (SSEs) that meet all the rigorous requirements, such as high ionic conductivity, oxidative stability with the cathode, and ease of processability, are lacking. We present here a new class of sodium‐based oxyhalide electrolytes NaNbCl 6‐2x O x with a facile mechanochemical synthesis. The oxyhalide NaNbCl 4 O exhibits close to two orders of magnitude higher ambient‐temperature sodium‐ion conductivity (1.03×10 −4 S cm −1 ) compared to the halide counterpart NaNbCl 6 (3×10 −6 S cm −1 ). Structural motifs unique to the oxygen content in NaNbCl 6‐2x O x are identified with 23 Na and 93 Nb magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and x‐ray diffraction (XRD). Solid‐state sodium batteries assembled with NaNbCl 4 O electrolyte and the cobalt‐ and nickel‐free layered Na 0.70 Fe 0.3 Mn 0.65 Al 0.05 O 2 cathode exhibit a maximum discharge capacity of 155 mAh g −1 with good cycle life at ambient temperature.

Kmiec, Steven↗
DOE OSTI2015

Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates

Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups—Mannich phenols and general bases—that are capable of reactivating OPC-inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Sulfono-g-AApeptides as a New Class of Nonnatural Helical Foldamer

Foldamers offer an attractive opportunity for the design of novel molecules that mimic the structures and functions of proteins and enzymes including biocatalysis and biomolecular recognition. Herein we report a new class of nonnatural helical sulfono-g-AApeptide foldamers of varying lengths. The crystal structure of the sulfono-g-AApeptide monomer S6 illustrates the intrinsic folding propensity of sulfono-g-AApeptides, which likely originates from the bulkiness of tertiary sulfonamide moiety. The two-dimensional solution NMR spectroscopy data for the longest sequence S1 demonstrates a 10/16 right-handed helical structure. Optical analysis using circular dichroism further supports welldefined helical conformation of sulfono-g-AApeptides in solution containing as few as five building blocks. Future development of sulfono-g-AApeptides may lead to new foldamers with discrete functions, enabling expanded application in chemical biology and biomedical sciences.

2D NMR spectroscopy↗
DOE OSTI2017

Development of a New Structural Class of Broadly Acting HCV Non-Nucleoside Inhibitors Leading to the Discovery of MK-8876

Studies directed at developing a broadly acting non-nucleoside inhibitor of HCV NS5B led to the discovery of a novel structural class of 5-aryl benzofurans that simultaneously interact with both the palm I and palm II binding regions. An initial candidate was potent in vitro against HCV GT1a and GT1b replicons, and induced multi-log reductions in HCV viral load when orally dosed to chronic GT1 infected chimpanzees. However, in vitro potency losses against clinically relevant GT1a variants prompted a further effort to develop compounds with sustained potency across a broader array of HCV genotypes and mutants. Ultimately, a biology and medicinal chemistry collaboration led to the discovery of the development candidate MK-8876. MK-8876 demonstrated a pan-genotypic potency profile and maintained potency against clinically relevant mutants. It demonstrated moderate bioavailability in rats and dogs, but showed low plasma clearance characteristics consistent with once-daily dosing. Herein we describe the efforts which led to the discovery of MK-8876, which advanced into Phase 1 monotherapy studies for evaluation and characterization as a component of an all-oral direct-acting drug regimen for the treatment of chronic HCV infection.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗