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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Hybrid Biological–Chemical Approach Offers Flexibility and Reduces the Carbon Footprint of Biobased Plastics, Rubbers, and Fuels

A critical challenge for the bioenergy research community has been producing drop-in hydrocarbon fuels and chemicals at yields sufficient to compete with their petroleum-derived counterparts. Biological production of highly reduced compounds poses fundamental challenges. Conversely, glucose, xylose, and sucrose can be fermented to ethanol at near-theoretical yields. Just as olefin crackers are often considered a gateway for petrochemical complexes that produce an array of downstream products, catalytic ethanol upgrading can potentially enable an entire biorefining complex able to produce renewable, low-carbon fuels and chemicals. By doping the Ta 2 O 5 /SiO 2 catalyst with different transition metals, we show herein that Ostromyslensky catalysts can be utilized for direct conversion of ethanol to varying ratios of 1,3-butadiene (1,3-BD), dietheylether (DEE), and ethylene. These results are integrated into the first comprehensive analysis of ethanol conversion to 1,3-BD, DEE, and ethylene that incorporates empirical data with chemical process modeling and life-cycle greenhouse gas (GHG) assessment. We find that the suite of products can replace conventional rubber, plastics, and diesel, achieving as much as a 150% reduction in GHG-intensity relative to fossil pathways (net carbon sequestration). Selecting the route with the greatest ethylene and DEE output can maximize total potential emission reductions.

09 BIOMASS FUELS↗
DOE OSTI2021

The sol–gel autocombustion as a route towards highly CO 2 -selective, active and long-term stable Cu/ZrO 2 methanol steam reforming catalysts

The adaption of the sol-gel autocombustion method to the Cu/ZrO 2 system opens new pathways for the specific optimisation of the activity, long-term stability and CO 2 selectivity of methanol steam reforming (MSR) catalysts. Calcination of the same post-combustion precursor at 400 °C, 600 °C or 800 °C allows accessing Cu/ZrO 2 interfaces of metallic Cu with either amorphous, tetragonal or monoclinic ZrO 2 , influencing the CO 2 selectivity and the MSR activity distinctly different. While the CO 2 selectivity is less affected, the impact of the post-combustion calcination temperature on the Cu and ZrO 2 catalyst morphology is more pronounced. A porous and largely amorphous ZrO 2 structure in the sample, characteristic for sol-gel autocombustion processes, is obtained at 400 °C. This directly translates into superior activity and long-term stability in MSR compared to Cu/tetragonal ZrO 2 and Cu/monoclinic ZrO 2 obtained by calcination at 600 °C and 800 °C. The morphology of the latter Cu/ZrO 2 catalysts consists of much larger, agglomerated and non-porous crystalline particles. Based on aberration-corrected electron microscopy, we attribute the beneficial catalytic properties of the Cu/amorphous ZrO 2 material partially to the enhanced sintering resistance of copper particles provided by the porous support morphology.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Structural and transport properties of CdSe nanorods

The nanorods of cadmium selenide (CdSe) have been synthesized by soft chemical route. The selected area electron diffraction pattern, high resolution TEM and X-ray diffraction pattern indicate the cubic structure of the sample. The band gap of the sample is obtained using Tauc relation to UV-visible spectrum and found to be 1.92 eV. 1{sup st} order and 2{sup nd} order Raman bands are followed to investigate the behaviour of the phonon modes of the materials which is considered to be important to predict the potential of the material to microwave applications. Thermal behaviour of the sample is investigated using differential scanning calorimeter. Kissinger equation is used to calculate the activation energy of the sample, which is found to be 1.67 eV.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1972

Digital canopus tracker digital electronics

Circuitry has been developed for digital control of the Canopus tracker. A feasibility and demonstration breadboard has been constructed using microelectronic integrated circuits. The breadboard contains the digital circuits necessary for closed-digital logic necessary for star acquisition, particle rejection, programmable gate selection, cone angle selection, and routing of the digital roll error signal.

Crawford, W. E.↗
NASA NTRS1979

Recommendations of the panels: Panel on flight planning to avoid high ozone

Flights planned or accomplished during certain months of the year at the higher latitudes and altitudes at or above the tropopause are discussed. Cabin ozone level limitations are established, and additional information is required for more accurate and qualtitative forecasting and design data base for operational utilization. Better tropopause heights, ozone concentration and corresponding meteorological data along selected flight routes, and meteorological data were investigated.

Mohnen, V. A.↗
NASA NTRS1985

Analysis of adaptive algorithms for an integrated communication network

Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes.

Reed, Daniel A.↗
NASA NTRSDate not supplied

Reasoning Service Exemplars for NASA’s Data and Reasoning Fabric

Future operations for Urban and Advanced Air Mobility are enabled by a distributed network of reliable and secured data and reasoning services referred to here as a fabric. In the aggregate, such a system must be all encompassing and mission agnostic, but specific use-cases are still needed to improve understanding and drive design paradigms. For this purpose, three reasoning service exemplars for Target Selection and Routing, Trajectory Generation, and Battery Health Management were developed and integrated into a specific NASA proposed data and reasoning fabric. These services were then used to build a mission reasoning application for lightning strike reconnaissance developed in collaboration with the Civil Air Patrol. Autonomous mission execution was then demonstrated using a multivehicle simulation platform with a full envelope 6 Degree-of-Freedom dynamics model for a concept electric Vertical Takeoff and Landing aircraft.

Autonomy↗
DOE OSTI2015

Systems for the Intermodal Routing of Spent Nuclear Fuel

The safe and secure movement of spent nuclear fuel from shutdown and active reactor facilities to intermediate or long term storage sites may, in some instances, require the use of several modes of transportation to accomplish the move. To that end, a fully operable multi-modal routing system is being developed within Oak Ridge National Laboratory s (ORNL) WebTRAGIS (Transportation Routing Analysis Geographic Information System). This study aims to provide an overview of multi-modal routing, the existing state of the TRAGIS networks, the source data needs, and the requirements for developing structural relationships between various modes to create a suitable system for modeling the transport of spent nuclear fuel via a multimodal network. Modern transportation systems are comprised of interconnected, yet separate, modal networks. Efficient transportation networks rely upon the smooth transfer of cargoes at junction points that serve as connectors between modes. A key logistical impediment to the shipment of spent nuclear fuel is the absence of identified or designated transfer locations between transport modes. Understanding the potential network impacts on intermodal transportation of spent nuclear fuel is vital for planning transportation routes from origin to destination. By identifying key locations where modes intersect, routing decisions can be made to prioritize cost savings, optimize transport times and minimize potential risks to the population and environment. In order to facilitate such a process, ORNL began the development of a base intermodal network and associated routing code. The network was developed using previous intermodal networks and information from publicly available data sources to construct a database of potential intermodal transfer locations with likely capability to handle spent nuclear fuel casks. The coding development focused on modifying the existing WebTRAGIS routing code to accommodate intermodal transfers and the selection of prioritization constraints and modifiers to determine route selection. The limitations of the current model and future directions for development are discussed, including the current state of information on possible intermodal transfer locations for spent fuel.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Connected Traveler

The Connected Traveler project is a multi-disciplinary undertaking that seeks to validate potential for transformative transportation system energy savings by incentivizing efficient traveler behavior. This poster outlines various aspects of the Connected Traveler project, including market opportunity, understanding traveler behavior and decision-making, automation and connectivity, and a projected timeline for Connected Traveler's key milestones.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2016

Connected Traveler

The Connected Traveler framework seeks to boost the energy efficiency of personal travel and the overall transportation system by maximizing the accuracy of predicted traveler behavior in response to real-time feedback and incentives. It is anticipated that this approach will establish a feedback loop that 'learns' traveler preferences and customizes incentives to meet or exceed energy efficiency targets by empowering individual travelers with information needed to make energy-efficient choices and reducing the complexity required to validate transportation system energy savings. This handout provides an overview of NREL's Connected Traveler project, including graphics, milestones, and contact information.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

Method and apparatus for scheduling in a non-uniform compute device

A data processing apparatus, and method of operation thereof, for executing instructions. The apparatus includes one or more host processors, each having a first processing unit, and a multi-level memory system. One or more levels of the memory system are tightly coupled to a corresponding second processing unit. At least one of the host processors includes an instruction scheduler that routes instructions selectively to at least one of the first and second processing units, dependent upon the availability of the processing units and the location, within the memory system, of data to be used when executing the instructions.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

Routing Options for Transporting Commercial Spent Nuclear Fuel in the Continental United States - 17504

The U.S. Department of Energy (DOE) has a goal to develop solutions for the long-term, sustainable management of the nation's spent nuclear fuel and high-level radioactive waste. The DOE is planning for an integrated waste management system to transport, store, and dispose of spent nuclear fuel and high-level radioactive waste from commercial electricity generation, as well national defense activities. The DOE Office of Nuclear Energy (DOE-NE), Office of Spent Fuel and Waste Disposition's (SFWD) Integrated Waste Management (IWM) program is applying integrated waste management system analysis, system engineering, and decision analysis principles to inform future decisions regarding potential future nuclear waste management system architectures. Integrated waste management system architecture analyses are being conducted to support the future deployment of a comprehensive system for managing nuclear waste that considers all aspects of the back-end of the nuclear fuel cycle (transportation, storage, and disposal). One aspect of a potential future nuclear waste management system is transportation of spent nuclear fuel from the fleet of commercial nuclear reactors to destinations where waste management facilities, such as an interim storage facility, would be located. Example rail transportation routes from commercial nuclear reactor sites to various locations in the continental U.S. - chosen as hypothetical locations for future waste management system facilities - were evaluated in 2014 using DOE's GIS-based Stakeholder Tool for Assessing Radioactive Transportation (START). The objective of that evaluation was to identify and parameterize generic transportation routes for use in integrated waste management system analyses, the associated uncertainty in these selections, and the uncertainty associated with different transportation route selection criteria. The analysis presented herein considers rail transportation routes from commercial nuclear reactor sites to hypothetical destinations within the continental U.S. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1974

Applications of ERTS-1 imagery to terrestrial and marine environmental analyses in Alaska

ERTS-1 imagery provides a means of distinguishing and monitoring estuarine surface water circulation patterns and changes in the relative sediment load of discharging rivers on a regional basis. It also will aid local fishing industries by augmenting currently available hydrologic and navigation charts. The interpretation of geologic and vegetation features resulted in preparation of improved surficial geology, vegetation and permafrost terrain maps at a scale of 1:1 million utilizing ERTS-1 band 7 imagery. This information will be further utilized in a route and site selection study for the Nome to Kobuk Road in central Alaska. Large river icings along the proposed Alaska pipeline route have been monitored. Sea ice deformation and drift northeast of Point Barrow, Alaska has been measured and shorefast ice accumulation and ablation along the west coast of Alaska is being mapped for the spring and early summer seasons. These data will be used for route and site selection, regional environmental analysis, identification and inventory of natural resources, land use planning, and in land use regulation and management.

Anderson, D. M.↗
NASA NTRSDate not supplied

Deep Reinforcement Learning based Routing in an Air-to-Air Ad-hoc Network

This paper studies the Multiple Sources and Multiple Destinations (MSMD) routing problem in a dynamic Air-to-Air Ad-hoc Network (AAAN). We consider a spectrum limited scenario where multiple links have to share the same frequency channel so that co-channel interference becomes inevitable. As a result, routing decisions and spectrum access are coupled and must be jointly considered. This paper proposes a deep Q-learning based algorithm to find an optimal routing and channel selection strategy that minimizes the end-to-end communication delay. Specifically, under the assumption that only local information is available to every node, the Deep Q-Network (DQN) is trained offline to learn the optimal routing and channel selection strategy. After the trained DQN is implemented in every node, multiple relay nodes can simultaneously determine their next-hop relay and channel selections in real-time. Simulation results demonstrate the efficacy of our proposed algorithm.

AAAN↗
NASA NTRSDate not supplied

Deep Reinforcement Learning based Routing in an Air-to-Air Ad-hoc Network

This paper studies the Multiple Sources and Multiple Destinations (MSMD) routing problem in a dynamic Air-to-Air Ad-hoc Network (AAAN). We consider a spectrum limited scenario where multiple links have to share the same frequency channel so that co-channel interference becomes inevitable. As a result, routing decisions and spectrum access are coupled and must be jointly considered. This paper proposes a deep Q-learning based algorithm to find an optimal routing and channel selection strategy that minimizes the end-to-end communication delay. Specifically, under the assumption that only local information is available to every node, the Deep Q-Network (DQN) is trained offline to learn the optimal routing and channel selection strategy. After the trained DQN is implemented in every node, multiple relay nodes can simultaneously determine their next-hop relay and channel selections in real-time. Simulation results demonstrate the efficacy of our proposed algorithm.

AAAN↗
NASA NTRS2002

Onboard Determination of Vehicle Glide Capability for Shuttle Abort Flight Managment (SAFM)

When one or more main engines fail during ascent, the flight crew of the Space Shuttle must make several critical decisions and accurately perform a series of abort procedures. One of the most important decisions for many aborts is the selection ofa landing site. Several factors influence the ability to reach a landing site, including the spacecraft point of atmospheric entry, the energy state at atmospheric entry, the vehicle glide capability from that energy state, and whether one or more suitable landing sites are within the glide capability. Energy assessment is further complicated by the fact that phugoid oscillations in total energy influence glide capability. Once the glide capability is known, the crew must select the "best" site option based upon glide capability and landing site conditions and facilities. Since most of these factors cannot currently be assessed by the crew in flight, extensive planning is required prior to each mission to script a variety of procedures based upon spacecraft velocity at the point of engine failure (or failures). The results of this preflight planning are expressed in tables and diagrams on mission-specific cockpit checklists. Crew checklist procedures involve leafing through several pages of instructions and navigating a decision tree for site selection and flight procedures - all during a time critical abort situation. With the advent of the Cockpit Avionics Upgrade (CAU), the Shuttle will have increased on-board computational power to help alleviate crew workload during aborts and provide valuable situational awareness during nominal operations. One application baselined for the CAU computers is Shuttle Abort Flight Management (SAFM), whose requirements have been designed and prototyped. The SAFM application includes powered and glided flight algorithms. This paper describes the glided flight algorithm which is dispatched by SAFM to determine the vehicle glide capability and make recommendations to the crew for site selection as well as to monitor glide capability while in route to the selected site. Background is provided on Shuttle entry guidance as well as the various types of Shuttle aborts. SAFM entry requirements and cockpit disp lays are discussed briefly to provide background for Glided Flight algorithm design considerations. The central principal of the Glided Flight algorithm is the use of energy-over-weight (EOW) curves to determine range and crossrange boundaries. The major challenges of this technique are exo-atmospheric flight, and phugoid oscillations in energy. During exo-atmospheric flight, energy is constant, so vehicle EOW is not sufficient to determine glide capability. The paper describes how the exo-atmospheric problem is solved by propagating the vehicle state to an "atmospheric pullout" state defined by Shuttle guidance parameters.

Straube, Timothy↗
DOE OSTI2015

Analysis of travel logistics for transportation of used nuclear fuel in the continental United States - 15179

The US DOE Office of Nuclear Energy is conducting planning activities within the Nuclear Fuels Storage and Transportation Planning Project (NFST) to lay the groundwork for implementing interim storage, including associated transportation, per the Administration's Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste, and to develop a foundation for a new nuclear waste management organization. Integrated waste management system architecture analyses are being conducted to support the future deployment of a comprehensive system for managing nuclear waste that consider all aspects of the back-end of the nuclear fuel cycle (transportation, storage, and disposal). One aspect of a potential future nuclear waste management strategy is the transportation of spent nuclear fuel to an away from reactor interim storage facility. Transportation routes from commercial nuclear reactor sites to various locations in the continental U.S. chosen as hypothetical locations for a future interim storage facility were evaluated using Stakeholder Tool for Assessing Radioactive Transportation (START). The objective of this evaluation was to identify and parameterize generic transportation routes for use in integrated waste management system analyses that include an interim storage facility, the associated uncertainty in these selections, and the uncertainty associated with different transportation route selection criteria. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗