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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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15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CdN by Materials Project

CdN is Molybdenum Carbide MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Cd2+ is bonded to six equivalent N2- atoms to form a mixture of edge, face, and corner-sharing CdN6 octahedra. The corner-sharing octahedral tilt angles are 47°. All Cd–N bond lengths are 2.43 Å. N2- is bonded to six equivalent Cd2+ atoms to form a mixture of distorted edge and corner-sharing NCd6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdN by Materials Project

CdN is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Cd2+ is bonded in a body-centered cubic geometry to eight equivalent N2- atoms. All Cd–N bond lengths are 2.59 Å. N2- is bonded in a body-centered cubic geometry to eight equivalent Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdN by Materials Project

CdN is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Cd2+ is bonded to six equivalent N2- atoms to form a mixture of corner and edge-sharing CdN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Cd–N bond lengths are 2.38 Å. N2- is bonded to six equivalent Cd2+ atoms to form a mixture of corner and edge-sharing NCd6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdN by Materials Project

CdN is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Cd2+ is bonded to six equivalent N2- atoms to form a mixture of distorted edge, corner, and face-sharing CdN6 pentagonal pyramids. All Cd–N bond lengths are 2.44 Å. N2- is bonded to six equivalent Cd2+ atoms to form a mixture of distorted edge, corner, and face-sharing NCd6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn(CdN)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2023

Ubiquitin-like conjugation by bacterial cGAS enhances anti-phage defence

Abstract cGAS is an evolutionarily conserved enzyme that has a pivotal role in immune defence against infection 1–3 . In vertebrate animals, cGAS is activated by DNA to produce cyclic GMP–AMP (cGAMP) 4,5 , which leads to the expression of antimicrobial genes 6,7 . In bacteria, cyclic dinucleotide (CDN)-based anti-phage signalling systems (CBASS) have been discovered 8–11 . These systems are composed of cGAS-like enzymes and various effector proteins that kill bacteria on phage infection, thereby stopping phage spread. Of the CBASS systems reported, approximately 39% contain Cap2 and Cap3 , which encode proteins with homology to ubiquitin conjugating (E1/E2) and deconjugating enzymes, respectively 8,12 . Although these proteins are required to prevent infection of some bacteriophages 8 , the mechanism by which the enzymatic activities exert an anti-phage effect is unknown. Here we show that Cap2 forms a thioester bond with the C-terminal glycine of cGAS and promotes conjugation of cGAS to target proteins in a process that resembles ubiquitin conjugation. The covalent conjugation of cGAS increases the production of cGAMP. Using a genetic screen, we found that the phage protein Vs.4 antagonized cGAS signalling by binding tightly to cGAMP (dissociation constant of approximately 30 nM) and sequestering it. A crystal structure of Vs.4 bound to cGAMP showed that Vs.4 formed a hexamer that was bound to three molecules of cGAMP. These results reveal a ubiquitin-like conjugation mechanism that regulates cGAS activity in bacteria and illustrates an arms race between bacteria and viruses through controlling CDN levels.

Science & Technology - Other Topics↗
DOE OSTI2020

Materials Data on CdCN2 by Materials Project

CdCN2 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three hydrogen cyanide molecules and three CdN sheets oriented in the (0, 0, 1) direction. In each CdN sheet, Cd2+ is bonded in a trigonal non-coplanar geometry to three equivalent N3- atoms. All Cd–N bond lengths are 2.27 Å. N3- is bonded in a trigonal non-coplanar geometry to three equivalent Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdCN2 by Materials Project

CdCN2 crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of three hydrogen cyanide molecules and three CdN clusters. In each CdN cluster, Cd2+ is bonded in a distorted single-bond geometry to one N3- atom. The Cd–N bond length is 2.13 Å. N3- is bonded in a single-bond geometry to one Cd2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Divergent viral phosphodiesterases for immune signaling evasion

Cyclic dinucleotides (CDNs) and other short oligonucleotides play fundamental roles in immune system activation in organisms ranging from bacteria to humans. In response, viruses use phosphodiesterase (PDE)-mediated oligonucleotide cleavage for immune evasion, a strategy whose diversity has not yet been explored. Here, we use a canonical 2H PDE (2H PDE) structure-based search of prokaryotic and eukaryotic viral sequences to identify an exceptional diversity of 2H PDEs across the virome, including enzymes not detectable with sequence search methods alone. Despite active site conservation, biochemical experiments reveal remarkable substrate specificity of these PDEs that corresponds to variations in the core 2H fold. This nuanced specificity allows 2H PDEs to selectively degrade oligonucleotide messengers to avoid interfering with host nucleotide signaling. Together, these findings nominate viral 2H PDEs as key regulators of CDN signaling across the tree of life.

CBASS↗
DOE OSTI2022

Which “second-best” climate policies are best? Simulating cost-effective policy mixes for passenger vehicles

In the real-world of political opposition and complex market failures, carbon pricing alone will not achieve deep GHG mitigation targets. Hence, in this study, we search for the most cost-effective “second-best” policies. Focusing on the light-duty vehicle sector in the case of Canada, we compare several policies in terms of effectiveness (regarding 2030 GHG goals) and mitigation costs, namely: (i) a carbon tax; (ii) a vehicle emission standard (or VES); (iii) a zero emissions vehicle (ZEV) mandate, and (iv) combinations of all three at various stringencies. In this effort, we apply the AUtomaker-consumer Model (AUM), which endogenously simulates consumer and automaker decisions and technological change. Comparing individual policies, the regulations are about three times more expensive than the carbon tax. Among “second-best” policies, the VES is cheaper than a ZEV mandate at lower stringencies, but at higher stringencies the two are similarly efficient (both incentivize widespread ZEV deployment). In policy mixes, cost-effectiveness is improved by a carbon tax. Specifically, inclusion of a CDN$100–150/tonne tax can achieve targets while being 30–40% less costly than a regulation alone. We suggest that policymakers implement carbon pricing as stringently as politically feasible (for efficiency), complemented by regulations as needed (for efficacy) to meet GHG targets.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

How to design a zero-emissions vehicle mandate? Simulating impacts on sales, GHG emissions and cost-effectiveness using the AUtomaker-Consumer Model (AUM)

We report although numerous studies investigate the impacts of policy on zero-emissions vehicle (ZEV) sales, few address the impacts of a ZEV sales mandate and its particular design features. We use the AUtomaker-consumer Model (AUM) to simulate varying designs of a ZEV mandate in Canada's light-duty vehicle sector, requiring 30% ZEV sales by 2030. Design features include: different penalties for non-compliance, different allocations of credits per ZEV type, and the allowance of banking credits across years. For each policy design, we consider impacts on ZEV adoption, GHG emissions, consumer surplus, automaker profits, and overall policy cost-effectiveness. Results demonstrate trade-offs among the policy designs. Generally, ZEV mandate designs that are more effective at increasing ZEV adoption and decreasing GHG emissions also induce larger reductions in consumer surplus and automaker profits. To achieve the ZEV sales goal, simulations show that a higher non-compliance penalty (CDN$ 10k per credit) is needed. ZEV adoption and GHG reductions are also improved by a “One credit per ZEV” scheme, rather than a “California-style” scheme that gives multiple credits per battery-electric vehicle. Further, allowing automakers to bank credits softens the policy impact on profit and increases automaker compliance in initial years. Across these different design combinations, we find that the most cost-effective design ($CDN/tonne mitigated, including consumer surplus and automaker profits impacts) utilizes a $10k non-compliance penalty and “One credit per ZEV” system that allows banking. Our analysis demonstrates the importance of various ZEV mandate design features, and the complex trade-offs involved among various policy goals.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Engineering endosomolytic nanocarriers of diverse morphologies using confined impingement jet mixing

The clinical translation of many biomolecular therapeutics has been hindered by undesirable pharmacokinetic (PK) properties, inadequate membrane permeability, poor endosomal escape and cytosolic delivery, and/or susceptibility to degradation. Overcoming these challenges merits the development of nanoscale drug carriers (nanocarriers) to improve the delivery of therapeutic cargo. Herein, we implement a flash nanoprecipitation (FNP) approach to produce nanocarriers of diverse vesicular morphologies by using various molecular weight PEG-bl-DEAEMA-co-BMA (PEG-DB) polymers. We demonstrated that FNP can produce uniform (PDI < 0.1) particles after 5 impingements, and that by varying the copolymer hydrophilic mass fraction, FNP enables access to a diverse variety of nanoarchitectures including micelles, unilamellar vesicles (polymersomes), and multi-compartment vesicles (MCVs). We synthesized a library of 2 kDa PEG block copolymers, with DEAEMA-co-BMA second block molecular weights of 3, 6, 12, 15, 20, and 30 kDa. All formulations were both pH responsive, endosomolytic, and capable of loading and cytosolically delivering small negatively charged molecules – albeit to different degrees. Using a B16.F10 melanoma model, we showcased the therapeutic potential of a lead FNP formulated PEG-DB nanocarrier, encapsulating the cyclic dinucleotide (CDN) cGAMP to activate the stimulator of interferon genes (STING) pathway in a therapeutically relevant context. Collectively, these data demonstrate that an FNP process can be used to formulate pH-responsive nanocarriers of diverse morphologies using a PEG-DB polymer system. As FNP is an industrially scalable process, these data address the critical translational challenge of producing PEG-DB nanoparticles at scale. Furthermore, the diverse morphologies produced may specialize in the delivery of distinct biomolecular cargos for other therapeutic applications, implicating the therapeutic potential of this platform in an array of disease applications.

36 MATERIALS SCIENCE↗
NASA NTRS2006

Canadian Led X-ray Polarimeter Mission CXP

We propose a Canadian-led X-ray Polarimetry Mission (CXP), to include a scattering X-ray Polarimeter and sensitive All-Sky X-ray Monitor (ASXM). Polarimetry would provide a new observational window on black holes, neutron stars, accretion disks and jets, and the ASXM would offer sensitive monitoring of the volatile X-ray sky. The envisioned polarimeter consists of a hollow scattering beryllium cone surrounded by an annular proportional counter, in a simple and elegant design that is reliable and low-risk. It would be sensitive in the 6-30 keV band to approx. 3% polarization in approx. 30 Galactic sources and 2 AGN in a baseline 1-yr mission, and have sensitivity greater than 10 times that of the previous X-ray polarimeter flown (NASA's OSO-8, 1975-78) for most sources. This X-ray polarimeter would tackle questions like, Do black holes spin?, How do pulsars pulse?, What is the geometry of the magnetic field in accreting neutron stars? Where and how are jets produced in microquasars and AGN?, What are the geometries of many of the most famous accretion-disk systems in the sky? This will be done using a novel and until-now unexploited technique that will greatly broaden the available observational phase space of compact objects by adding to timing and spectroscopy observations of polarization fraction and position angle as a function of energy. The All-Sky X-ray Monitor would scan for transients, both as potential targets for the polarimeter but also as a service to the worldwide astronomical community. The entire CXP mission could be flown for $40- 60M CDN, according to estimates by ComDev International, and could be built entirely in Canada. It would fall well within the CSA's SmallSat envelope and would empower the growing and dynamic Canadian High-Energy Astrophysics community with world leadership in a potentially high impact niche area.

Kaspi, V.↗
NASA NTRS2010

Calibration for Thrust and Airflow Measurements in the CE-22 Advanced Nozzle Test Facility

CE-22 facility procedures and measurements for thrust and airflow calibration obtained with choked-flow ASME nozzles are presented. Six calibration nozzles are used at an inlet total pressure from 20 to 48 psia. Throat areas are from 9.9986 to 39.986 sq. in.. Throat Reynolds number varies from 1.8 to 7.9 million. Nozzle gross thrust coefficient (CFG) uncertainty is 0.25 to 0.75 percent, with smaller uncertainly generally for larger nozzles and higher inlet total pressure. Nozzle discharge coefficient (CDN) uncertainty is 0.15 percent or less for all the data. ASME nozzle calibrations need to be done before and after research model testing to achieve these uncertainties. In addition, facility capability in terms of nozzle pressure ratio (NPR) and nozzle airflow are determined. Nozzle pressure ratio of 50 or more is obtainable at 40 psia for throat areas between 20 and 30 sq. in.. Also presented are results for two of the ASME nozzles vectored at 10deg, a dead-weight check of the vertical (perpendicular to the jet axis) force measurement, a calibration of load cell forces for the effects of facility tank deflection with tank pressure, and the calibration of the metric-break labyrinth seal.

Werner, Roger A.↗
NASA NTRS2021

A Geodetic and Positioning Thematic Layer - Identifying tools to connect the GGRF and IGIF

Effective and sustainable modernization of a nation’s geodetic framework relies on the ability of the relevant organizations and other stakeholders to communicate, integrate, and align both their strategic objectives and operational planning with the United Nations Committee of Experts on Global Geospatial Information Management (UN GGIM) Sub-Committee on Geodesy’s (SCoG) roadmap for a Global Geodetic Reference Frame (GGRF) for Sustainable Development. In addition, to implement geodetic modernization initiatives through multiple government agencies, a holistic country action plan (CAP) for geospatial information management must incorporate pertinent geodetic outcomes and outputs. Presently, the CAP framework and principles used by nations is the UN GGIM Integrated Geospatial Information Framework (IGIF). From engagement with geospatial and survey communities across emerging nations in the Asia Pacific region, it is evident more assistance and coordination is necessary to articulate, integrate and connect geodetic organizational strategies with the requirements of the GGRF roadmap; the strategic pathways of the IGIF; and resourcing for a meaningful and relevant multi-faceted CAP. One of the supporting mechanisms for such planning or preparation, which representatives of the International Federation of Surveyors (FIG) Asia Pacific Capacity Development Network (AP CDN) and the UN SCoG Education, Training and Capacity Building (ETCB) working group are considering, is a policy framework and guide for a “Geodetic and Positioning Thematic Layer” (GPTL). Essentially, this “thematic layer”, in terms of the GGRF and IGIF, aims to provide a comprehensive understanding of, and a toolbox for, the “why, what, how, and who” of geodesy and positioning. This discussion paper will provide background and insights for a GPTL dedicated to recognizing, and aligning the geodetic capacity development needs with broader geospatial information management issues and applications. The paper will also outline a rigorous, participatory, and inclusive consultation process for the design and development of a thematic layer. Furthermore, as the intention of the authors is to prepare a forthcoming “white paper” that will concisely describe the issues of a GPTL and initiatives for an appropriate guide and/or policy framework, this paper will seek feedback on: the potential scientific, social, environmental and political benefits of modernizing geodetic infrastructure and systems; the challenges associated with the GGRF roadmap; leveraging the geodesy-relevant elements of each IGIF strategic pathway; the importance of collaborative efforts; and the capacity development needs and resources in relation to governance, technology and people.

SARIB, Rob↗