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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on GaP by Materials Project

GaP is High Pressure Cadmuum Telluride structured and crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Ga3+ is bonded in a linear geometry to two equivalent P3- atoms. Both Ga–P bond lengths are 2.63 Å. P3- is bonded to two equivalent Ga3+ and four equivalent P3- atoms to form a mixture of edge and corner-sharing PGa2P4 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.56 Å) and two longer (2.57 Å) P–P bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaP by Materials Project

GaP is SC16 CuCl, stable at 5GPa structured and crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Ga3+ is bonded to four equivalent P3- atoms to form corner-sharing GaP4 tetrahedra. There are one shorter (2.34 Å) and three longer (2.43 Å) Ga–P bond lengths. P3- is bonded to four equivalent Ga3+ atoms to form corner-sharing PGa4 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaP by Materials Project

GaP crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Ga3+ is bonded in a distorted see-saw-like geometry to four equivalent P3- atoms. There are two shorter (2.52 Å) and two longer (2.54 Å) Ga–P bond lengths. P3- is bonded in a distorted see-saw-like geometry to four equivalent Ga3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Gap Analysis of Supply Chain Cybersecurity for Distributed Energy Resources

A supply chain is the combination of the ecosystem of resources needed to design, manufacture, and distribute a product. In the context of supply chain cybersecurity, the resources that directly influence this ecosystem include software, data, and/or other digital components. Compromised equipment or software in the supply chain may lead to attacks such as financial loss; denial of service; a breach of confidential or proprietary information from a company, its customers, or its suppliers; ransomware that denies operation of automated equipment for payment; and malicious control actions that could damage equipment and endanger personnel. Currently 60.8% of US energy comes from fossil fuels, 18.9% comes from nuclear energy, and the last 20.1% comes from renewable sources. Federal Energy Regulatory Commission order FERC 2222 and Executive Order 14017 on America's Supply Chains are important milestones for safely expanding generation from renewable energy and achieving the goal of a decarbonized U.S. energy sector by 2035. This report analyzes gaps and opportunities in the supply chain currently available to the renewable energy sector, to help stakeholders formulate a coordinated response.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2026

Cybersecurity Standards for Distributed Energy Resources: Gaps and Harmonization Strategy

This report examines cybersecurity standards for Distributed Energy Resources (DERs) in light of their rapid growth and increasing integration into energy systems. It identifies critical gaps in existing frameworks, including inadequate coverage of DER-specific challenges, complexities in implementing comprehensive standards, integration issues with legacy systems, adoption hurdles for newer standards, and a lack of harmonization across regulatory landscapes. The analysis highlights vulnerabilities such as data integrity risks, unauthorized device control, and denial-of-service attacks across various DER technologies like solar PV, wind turbines, energy storage systems, and hydrogen fuel cells. The report proposes a harmonization strategy to address these deficiencies by developing unified cybersecurity requirements, certification programs, and training resources while fostering collaboration among stakeholders such as government agencies, industry groups, DER operators, manufacturers, and research institutions. A phased roadmap is outlined to refine and implement these measures through pilot testing and widespread adoption. Ultimately, the report underscores the urgent need for coordinated efforts to enhance DER cybersecurity and ensure the reliable operation of future energy systems.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Status of Cable Aging Knowledge Gaps Identified in the Expanded Materials Degradation Assessment (EMDA)

This report summarizes research relevant to cable aging knowledge gaps identified in NUREG/CR-7153, “Expanded Materials Degradation Assessment (EMDA) Volume 5: Aging of Cables and Cable Systems” (EMDA Vol. 5), performed since the EMDA Vol. 5 was published in 2014. It begins with a discussion of the status of cables in long-term operation of U.S. nuclear power plants (NPPs) and the most common cables found in NPP containment. Next, the major polymer cable insulations, and the mechanisms of concern for degradation of those polymers in service are reviewed. A description of the environmental qualification (EQ) process historically used for safety-related cables is provided as is a review of the potential concerns with that process highlighted in the EMDA Vol. 5. Research addressing each of these is then reviewed. Finally, three potential strategies to support continued safe operation of aging cables are proposed: advanced condition-based verification, targeted material aging studies, and predictive simulation.

42 ENGINEERING↗
NASA NTRS1997

Electrical signal transmission and gap junction regulation in a bone cell network: a cable model for an osteon

A cable model is formulated to estimate the spatial distribution of intracellular electric potential and current, from the cement line to the lumen of an osteon, as the frequency of the loading and the conductance of the gap junction are altered. The model predicts that the characteristic diffusion time for the spread of current along the membrane of the osteocytic processes, 0.03 sec, is nearly the same as the predicted pore pressure relaxation time in Zeng et al. (Annals of Biomedical Engineering. 1994) for the draining of the bone fluid into the osteonal canal. This approximate equality of characteristic times causes the cable to behave as a high-pass, low-pass filter cascade with a maximum in the spectral response for the intracellular potential at approximately 30 Hz. This behavior could be related to the experiments of Rubin and McLeod (Osteoporosis, Academic Press, 1996) which show that live bone appears to be selectively responsive to mechanical loading in a specific frequency range (15-30 Hz) for several species.

NASA Discipline Musculoskeletal↗
NASA NTRS2000

Assessment of Zr-Fe-V getter alloy for gas-gap heat switches

A commercial Zr-V-Fe alloy (i.e., SAES Getters trade name alloy St-172) has been assessed as reversible hydrogen storage material for use in actuators of gas gap heat switches. Two prototype actuators containing the SAES St-172 material were built and operated for several thousand cycles to evaluate performance of the metal hydride system under conditions simulating heat switch operation.

metal hydrides gas gap heat switches hydrogen stor↗
NASA NTRS1999

Development of Gas Gap Heat Switch Actuator for the Planck Sorption Cryocooler

We present the general principles of gas gap heat switches that impact their performances for the Planck cryocooler, develop two figures of merit relevant to this application, and present initial characterization results of switches using uranium or ZrNi as the hydriding material.

Gas Gap Heat Switch Actuator Cryocooler↗
NASA NTRS2013

Preparing for Humans at Mars, MPPG Updates to Strategic Knowledge Gaps and Collaboration with Science Missions

The Mars Program Planning Group (MPPG) was an agency wide effort, chartered in March 2012 by the NASA Associate Administrator for Science, in collaboration with NASA's Associate Administrator for Human Exploration and Operations, the Chief Scientist, and the Chief Technologist. NASA tasked the MPPG to develop foundations for a program-level architecture for robotic exploration of Mars that is consistent with the President's challenge of sending humans to the Mars system in the decade of the 2030s and responsive to the primary scientific goals of the 2011 NRC Decadal Survey for Planetary Science. The Mars Exploration Program Analysis Group (MEPAG) also sponsored a Precursor measurement Strategy Analysis Group (P-SAG) to revisit prior assessments of required precursor measurements for the human exploration of Mars. This paper will discuss the key results of the MPPG and P-SAG efforts to update and refine our understanding of the Strategic Knowledge Gaps (SKGs) required to successfully conduct human Mars missions.

Viking↗
NASA NTRS2017

Passive Gas-Gap Heat Switches for Use in Low-Temperature Cryogenic Systems

We present the current state of development in passive gas-gap heat switches. This type of switch does not require a separate heater to activate heat transfer but, instead, relies upon the warming of one end due to an intrinsic step in a thermodynamic cycle to raise a getter above a threshold temperature. Above this temperature sequestered gas is released to couple both sides of the switch. This enhances the thermodynamic efficiency of the system and reduces the complexity of the control system. Various gas mixtures and getter configurations will be presented.

Gas-gap↗
NASA NTRSDate not supplied

Development of Slat-gap and Slat-cove Filler Treatments for Noise Reduction Assessment on the High Lift Common Research Model in the NASA LaRC 14x22

Airframe noise is an important issue during the approach and landing phases of flight because engines are throttled back, and airframe sources become an equal or greater contributor to environmental noise. The leading-edge slat component of the high-lift system for transport aircraft has been identified as a prominent source of airframe noise. Noise production mechanisms and potential treatments to mitigate airframe noise have been areas of active research for nearly three decades. Two promising technologies for slat noise reduction are the slat-gap filler (SGF) and slat-cove filler (SCF). Previous work was done using a 2D section of a transport class aircraft wing to demonstrate their feasibility via benchtop and computational models. A wind tunnel test campaign was recently undertaken to test the SGF and SCF technologies in a flight-like environment by installing dynamically scaled treatments on the 10%-scale High-Lift Common Research Model (CRM-HL), which is representative of a commercial twin-aisle transport aircraft. Advancement of the SGF and SCF technologies to overcome challenges of integration with 3D airframe structures, computational simulations of the CRM-HL predicting the aerodynamic and aeroacoustic performance and structural loads, and design of wind tunnel model hardware with features accommodating noise treatments were conducted in parallel. Details of innovations in the SGF and SCF technologies for 3D airframe feasibility will be described. The loads the treatments must sustain in flight and the influence of those loads on the design is also discussed. Finally, the design of wing leading-edge assemblies to treat the 10% CRM-HL with dynamically scaled SGF and SCF components is presented. The treatments were successfully tested in 2020/2021 providing a demonstration of leading-edge noise reduction using components that would allow slat articulation.

airframe noise reduction↗