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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 1,333 records · Page 74

Manufacturability and performance response of developed Ni-based alloys for reactor environments

Under the Advanced Materials and Manufacturing Technologies program, two Ni-based alloys fabricated by laser powder bed fusion (LPBF) at ORNL and laser powder directed energy deposition (LP-DED) at INL have been evaluated: γ′-strengthened Haynes 282 and solution-strengthened Inconel 625. Printing defects were observed in the LPBF 282 alloy fabricated using a Renishaw AM250 machine, likely due to particle spattering during printing. For both the LPBF and LP-DED 282 alloys, annealing at 1,180°C for 1 h resulted in partial recrystallization and a bimodal grain distribution, while subsequent aging for 4 h at 800°C led to the formation of a high density of nano size γ′-strengthening precipitates. Creep testing performed at 750°C revealed lower creep life and ductility for the LPBF and LP-DED 282 compared with wrought 282. X-ray computed tomography combined with optical and scanning electron microscopy microstructural characterization revealed crack formation in the LPBF 282 alloy during creep testing, initiated either from printing defects or from creep cavitation at grain boundaries. Creep cavitation and cracking at grain boundaries were also observed for the LP-DED 282 alloy, and optimization of the printing strategies and post heat treatments will be needed to fabricate high performance 282 components for high temperature nuclear applications.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Dosimetric commissioning and quality assurance of scanned ion beams at the Italian National Center for Oncological Hadrontherapy

Purpose: To describe the dosimetric commissioning and quality assurance (QA) of the actively scanned proton and carbon ion beams at the Italian National Center for Oncological Hadrontherapy. Methods: The laterally integrated depth-dose-distributions (IDDs) were acquired with the PTW Peakfinder, a variable depth water column, equipped with two Bragg peak ionization chambers. FLUKA Monte Carlo code was used to generate the energy libraries, the IDDs in water, and the fragment spectra for carbon beams. EBT3 films were used for spot size measurements, beam position over the scan field, and homogeneity in 2D-fields. Beam monitor calibration was performed in terms of number of particles per monitor unit using both a Farmer-type and an Advanced Markus ionization chamber. The beam position at the isocenter, beam monitor calibration curve, dose constancy in the center of the spread-out-Bragg-peak, dose homogeneity in 2D-fields, beam energy, spot size, and spot position over the scan field are all checked on a daily basis for both protons and carbon ions and on all beam lines. Results: The simulated IDDs showed an excellent agreement with the measured experimental curves. The measured full width at half maximum (FWHM) of the pencil beam in air at the isocenter was energy-dependent for both particle species: in particular, for protons, the spot size ranged from 0.7 to 2.2 cm. For carbon ions, two sets of spot size are available: FWHM ranged from 0.4 to 0.8 cm (for the smaller spot size) and from 0.8 to 1.1 cm (for the larger one). The spot position was accurate to within ±1 mm over the whole 20 × 20 cm{sup 2} scan field; homogeneity in a uniform squared field was within ±5% for both particle types at any energy. QA results exceeding tolerance levels were rarely found. In the reporting period, the machine downtime was around 6%, of which 4.5% was due to planned maintenance shutdowns. Conclusions: After successful dosimetric beam commissioning, quality assurance measurements performed during a 24-month period show very stable beam characteristics, which are therefore suitable for performing safe and accurate patient treatments.

60 APPLIED LIFE SCIENCES↗

Technical Highlight: NREL Tests Integrated Heat Pump Water Heater Performance in Different Climates (Fact Sheet)

This technical highlight describes NREL tests to capture information about heat pump performance across a wide range of ambient conditions for five heat pump water heaters (HPWH). These water heaters have the potential to significantly reduce water heater energy use relative to traditional electric resistance water heaters. These tests have provided detailed performance data for these appliances, which have been used to evaluate the cost of saved energy as a function of climate. The performance of HPWHs is dependent on ambient air temperature and humidity and the logic controlling the heat pump and the backup resistance heaters. The laboratory tests were designed to measure each unit's performance across a range of air conditions and determine the specific logic controlling the two heat sources, which has a large effect on the comfort of the users and the energy efficiency of the system. Unlike other types of water heaters, HPWHs are both influenced by and have an effect on their surroundings. Since these effects are complex and different for virtually every house and climate region, creating an accurate HPWH model from the data gathered during the laboratory tests was a main goal of the project. Using the results from NREL's laboratory tests, such as the Coefficient of Performance (COP) curves for different air conditions as shown in Figure 1, an existing HPWH model is being modified to produce more accurate whole-house simulations. This will allow the interactions between the HPWH and the home's heating and cooling system to be evaluated in detail, for any climate region. Once these modeling capabilities are in place, a realistic cost-benefit analysis can be performed for a HPWH installation anywhere in the country. An accurate HPWH model will help to quantify the savings associated with installing a HPWH in the place of a standard electric water heater. In most locations, HPWHs are not yet a cost-effective alternative to natural gas water heaters. The detailed system performance maps that were developed by this testing program will be used to: (1) Target regions of the country that would benefit most from this technology; (2) Identify improvements in current systems to maximize homeowner cost savings; and (3) Explore opportunities for development of advanced hot water heating systems.

03 NATURAL GAS↗

Automotive Li-Ion Batteries: Current Status and Future Perspectives

Lithium-ion batteries (LIBs) are currently the most suitable energy storage device for powering electric vehicles (EVs) owing to their attractive properties including high energy efficiency, lack of memory effect, long cycle life, high energy density and high power density. These advantages allow them to be smaller and lighter than other conventional rechargeable batteries such as lead–acid batteries, nickel–cadmium batteries (Ni–Cd) and nickel–metal hydride batteries (Ni–MH). Modern EVs, however, still suffer from performance barriers (range, charging rate, lifetime, etc.) and technological barriers (high cost, safety, reliability, etc.), limiting their widespread adoption. Given these facts, this review sets the extensive market penetration of LIB-powered EVs as an ultimate objective and then discusses recent advances and challenges of electric automobiles, mainly focusing on critical element resources, present and future EV markets, and the cost and performance of LIBs. Finally, novel battery chemistries and technologies including high-energy electrode materials and all-solid-state batteries are also evaluated for their potential capabilities in next-generation long-range EVs.

25 ENERGY STORAGE↗

Observations of High-Energy Phenomena with Swift and GLAST

The Swift and CLAST missions promise a great increase in our understanding of the gamma-ray universe. Swift was launched in November 2004 with a primary objective to study gamma-ray bursts. All instruments are performing well and more than 100 GRBs have been studied in detail. Major advances have already been made in the areas of short bursts, high redshift events and afterglow physics. The CLAST mission is scheduled for launch in fall 2007. It features a large new-technology instrument for high energy gamma-ray observations. Thousands of sources will be detected over a 5-10 year lifetime leading to the huge step forward in studies of the energetic gamma-ray sky.

Gehrels, Neil↗

New Whole-House Solutions Case Study: Fort Devens: Cold Climate Market-Rate Townhomes Targeting HERS Index of 40, Harvard, Massachusetts

Achieving aggressive energy efficiency targets requires tight coordination and clear communication among owners, designers, builders, and subcontractors. For this townhome project, MassDevelopment, the quasi-governmental agency owner, selected Metric Development of Boston, teaming with Building America team Consortium for Advanced Residential Buildings (CARB) and Cambridge Seven Architects, to build very high performing market-rate homes. Fort Devens is part of a decommissioned army base in working-class Harvard, Massachusetts, approximately one hour northwest of Boston. The team proposed 12 net zero energy-ready townhomes that were also designed to achieve a Home Energy Rating System (HERS) Index Score of 41 before adding renewables. The team carefully planned the site to maximize solar access, daylighting, and efficient building forms.

air tight envelope↗

SISGR -- Domain Microstructures and Mechanisms for Large, Reversible and Anhysteretic Strain Behaviors in Phase Transforming Ferroelectric Materials

This four-year project (including one-year no-cost extension) aimed to advance fundamental understanding of field-induced strain behaviors of phase transforming ferroelectrics. We performed meso-scale phase field modeling and computer simulation to study domain evolutions, mechanisms and engineering techniques, and developed computational techniques for nanodomain diffraction analysis; to further support above originally planned tasks, we also carried out preliminary first-principles density functional theory calculations of point defects and domain walls to complement meso-scale computations as well as performed in-situ high-energy synchrotron X-ray single crystal diffraction experiments to guide theoretical development (both without extra cost to the project thanks to XSEDE supercomputers and DOE user facility Advanced Photon Source).

36 MATERIALS SCIENCE↗

In-situ Spectroscopic and Structural Studies of Electrode Materials for Advanced Battery Applications

Techniques have been developed and implemented to gain insight into fundamental factors that affect the performance of electrodes in Li and Li-ion batteries and other energy storage devices. These include experimental strategies for monitoring the Raman scattering spectra of single microparticles of carbon and transition metal oxides as a function of their state of charge. Measurements were performed in electrolytes of direct relevance to Li and Li-Ion batteries both in the static and dynamic modes. In addition, novel strategies were devised for performing conventional experiments in ultrahigh vacuum environments under conditions which eliminate effects associated with presence of impurities, using ultrapure electrolytes, both of the polymeric and ionic liquid type that display no measurable vapor pressure. Also examined was the reactivity of conventional non aqueous solvent toward ultrapure Li films as monitored in ultrahigh vacuum with external reflection Fourier transform infrared spectroscopy. Also pursued were efforts toward developing applying Raman-scattering for monitoring the flow of charge of a real Li ion battery. Such time-resolved, spatially-resolved measurements are key to validating the results of theoretical simulations involving real electrode structures.

25 ENERGY STORAGE↗

Advanced ion thruster research

A simple model describing the discharge chamber performance of high strength, cusped magnetic field ion thrusters is developed. The model is formulated in terms of the energy cost of producing ions in the discharge chamber and the fraction of ions produced in the discharge chamber that are extracted to form the ion beam. The accuracy of the model is verified experimentally in a series of tests wherein the discharge voltage, propellant, grid transparency to neutral atoms, beam diameter and discharge chamber wall temperature are varied. The model is exercised to demonstrate what variations in performance might be expected by varying discharge chamber parameters. The results of a study of xenon and argon orificed hollow cathodes are reported. These results suggest that a hollow cathode model developed from research conducted on mercury cathodes can also be applied to xenon and argon. Primary electron mean free paths observed in argon and xenon cathodes that are larger than those found in mercury cathodes are identified as a cause of performance differences between mercury and inert gas cathodes. Data required as inputs to the inert gas cathode model are presented so it can be used as an aid in cathode design.

Wilbur, P. J.↗

Harnessing Relativistic Laser Plasmas to Generate Intense Ion Beams: A Plasma Science Frontier White Paper

Optical lasers with high intensity (> 10 19 W/cm 2 ), high power (> 100 TW) and high energy (> 50 J) are enabling research that is expanding the frontiers of physics. Some of the research opportunities and importance are described in several reports. Here we highlight a prominent one: harnessing relativistic laser plasmas to generate intense ion beams, much more intense than it is possible with conventional particle-acceleration technology. This topic is important in two ways. On the one hand, it represents exceedingly exciting science in plasma physics and extreme electrodynamics (i.e., “high-field” physics). On the other hand, it enables advanced technology for advancing other fields of science, for societal applications (e.g., fast ignition8) and for national defense. There are tremendous opportunities for continued progress in existing laser facilities in the US (with laser intensities up to ~ 10 21 W/cm 2 , such as the Trident Laser Facility) provided modest funding support and reorientation of these lasers as national user facilities. Longer term, there are also great scientific opportunities for the US by extending our capabilities to intensities of ~ 10 22 W/cm 2 and beyond with shaped laser pulses of intermediate duration (~ 100 fs), to complement high intensity, shorter pulse length lasers planned worldwide. Such a complementary US facility would in fact excel in the ion-beam generation mission proposed here. At ~ 10 22 W/cm 2 and beyond, besides meeting the requirements for important societal applications of intense ion beams, novel high-field physics becomes important and amenable to study. That includes e.g., radiation self-force for electrons, and direct coupling of the laser to the ions (not just to electrons and then indirectly to the ions). These new physics in turn may open new technological opportunities, such as x-ray and gamma-ray-beam sources and new ion-acceleration mechanisms. It is hard to overstate the impact of particle accelerators starting in the last century to the present. Accelerators have had profound impact in society, both as a key enabling experimental tool for the modern scientific edifice, as well as for societal applications such as cancer therapy. Conventional accelerator technology is bumping against two main limitations. One is particle energy (at a reasonable size and cost) rooted in the ~ 25 MeV/m gradient limit from electrical breakdown of conventional accelerator structures. The second is beam intensity, limited by current and space-charge stability of conventional (non-neutral) particle beams. The former issue is being addressed in ingenious ways by “dielectric accelerators” which use high-power, low-energy lasers to set up transient-high fields in dielectric microstructures. These devices promise to advance the state of the art in acceleration gradients, but of course cannot address the intensity limitations. Ultimately, the highest performance is going to require a plasma as the acceleration medium. Plasmas can support the highest accelerating potential gradients and the highest currents. Moreover, by delivering neutralized beams (ions co-moving with unbound electrons), the usual current and space-charge limits can be circumvented. Realizing the highest ion energies and intensities requires a high-power density source to drive the system. Intense, high-power, high-energy lasers represent an ideal drive source, provided the physics can be understood and controlled, i.e., a challenge proposed here. To meet that challenge, the science community can build on the significant progress over the last decade, experimentally, computationally and theoretically.

43 PARTICLE ACCELERATORS↗

Systems-To-Atoms (S2A): enabling hydrogen for climate security

The project addresses a critical gap in hydrogen infrastructure by integrating system-level energy models with atomic-scale material simulations in a unified Systems-to-Atoms (S2A) framework. The motivation stems from the need to develop efficient, cost-effective, and durable hydrogen transport and utilization technologies to support decarbonization of hard-to-electrify sectors such as heavy-duty transportation. Current system models lack awareness of material performance mechanisms, while material-scale models do not account for system-level usage and variability. To bridge this divide, the team developed a co-simulation capability linking techno-economic analyses, reactor/process-flow modeling, and molecular-scale catalysis simulations. Applied to hydrogen delivery in California, the framework enabled comparative evaluations of compressed, cryogenic, and liquid organic hydrogen carrier (LOHC) pathways, highlighting how catalyst operation and unit process efficiency influence overall performance. The results demonstrate that no single material or transport mode is universally optimal; instead, heterogeneous solutions tuned to specific operational contexts deliver better performance. The project delivers a new capability for cross-scale material co-design, advancing hydrogen infrastructure readiness and informing DOE and LLNL missions in climate and energy resilience.

organic↗

Advanced Communication Technology Satellite (ACTS) Multibeam Antenna On-Orbit Performance

The NASA Lewis Research Center's Advanced Communication Technology Satellite (ACTS) was launched in September 1993. ACTS introduced several new technologies, including a multibeam antenna (MBA) operating at extremely short wavelengths never before used in communications. This antenna, which has both fixed and rapidly reconfigurable high-energy spot beams (150 miles in diameter), serves users equipped with small antenna terminals. Extensive structural and thermal analyses have been performed for simulating the ACTS MBA on-orbit performance. The results show that the reflector surfaces (mainly the front subreflector), antenna support assembly, and metallic surfaces on the spacecraft body will be distorted because of the thermal effects of varying solar heating, which degrade the ACTS MBA performance. Since ACTS was launched, a number of evaluations have been performed to assess MBA performance in the space environment. For example, the on-orbit performance measurements found systematic environmental disturbances to the MBA beam pointing. These disturbances were found to be imposed by the attitude control system, antenna and spacecraft mechanical alignments, and on-orbit thermal effects. As a result, the MBA may not always exactly cover the intended service area. In addition, the on-orbit measurements showed that antenna pointing accuracy is the performance parameter most sensitive to thermal distortions on the front subreflector surface and antenna support assemblies. Several compensation approaches were tested and evaluated to restore on-orbit pointing stability. A combination of autotrack (75 percent of the time) and Earth sensor control (25 percent of the time) was found to be the best way to compensate for antenna pointing error during orbit. This approach greatly minimizes the effects of thermal distortions on antenna beam pointing.

Source record↗

Novel Power Electronics Three-Dimensional Heat Exchanger: Preprint

Electric drive systems for vehicle propulsion enable technologies critical to meeting challenges for energy, environmental, and economic security. Enabling cost-effective electric drive systems requires reductions in inverter power semiconductor area. As critical components of the electric drive system are made smaller, heat removal becomes an increasing challenge. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a heat flux improvement of a factor of two, and a package heat density improvement over 30%, which achieved the thermal performance targets.

30 DIRECT ENERGY CONVERSION↗

An innovative and advanced coupled neutron transport and thermal hydraulic method (tool) for the design, analysis and optimization of VHTR/NGNP prismatic reactors

This project will develop a 3D, advanced coarse mesh transport method (COMET-Hex) for steady- state and transient analyses in advanced very high-temperature reactors (VHTRs). The project will lead to a coupled neutronics and thermal hydraulic (T/H) core simulation tool with fuel depletion capability. The computational tool will be developed in hexagonal geometry, based solely on transport theory without (spatial) homogenization in complicated 3D geometries. In addition to the hexagonal geometry extension, collaborators will concurrently develop three additional capabilities to increase the code’s versatility as an advanced and robust core simulator for VHTRs. First, the project team will develop and implement a depletion method within the core simulator. Second, the team will develop an elementary (proof-of-concept) 1D time-dependent transport method for efficient transient analyses. The third capability will be a thermal hydraulic method coupled to the neutronics transport module for VHTRs. Current advancements in reactor core design are pushing VHTRs toward greater core and fuel heterogeneity to pursue higher burn-ups, efficiently transmute used fuel, maximize energy production, and improve plant economics and safety. As a result, an accurate and efficient neutron transport, with capabilities to treat heterogeneous burnable poison effects, is highly desirable for predicting VHTR neutronics performance. This research project’s primary objective is to advance the state of the art for reactor analysis.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Liquid Organic Battery Development: Cooperative Research and Development Final Report, CRADA Number CRD-14-540

Battery electric vehicles (BEV) have the potential to significantly reduce consumption of gasoline and emission of greenhouse gases. However, the commercial success of mass-market, long-range BEVs requires battery technology with a challenging combination of technical metrics -- specific energy, safety, fast recharge capability, cycle life, and cost. The NREL team proposes a robust, liquid-phase battery design utilizing a high-energy organic redox couple capable of decoupling these metrics via electrode exchange to provide the necessary combination of performance characteristics. The overall objective of this project is to demonstrate a functioning prototype and determine its ability to meet RANGE performance targets in large-scale production. Three main tasks described below will work towards this goal with the individual objectives of (1) identifying a robust, high-performance redox couple-solvent-additive combination, (2) designing and demonstrating a functional cell, and (3) analyzing the concept's potential performance and cost in future mass-production scenarios.

25 ENERGY STORAGE↗

Hot Weather Impacts on Electric School Buses

School bus fleets considering electric school buses can use this resource to learn how hot weather impacts them, and learn how to optimize bus performance when temperatures rise.

ADVANCED PROPULSION SYSTEMS↗

RLUOB Celebration

Los Alamos National Laboratory's newest facility, the Radiological Laboratory Utility Office Building (RLUOB), is also its first to achieve both the Leadership in Energy and Environmental Design (LEED) status and LEED Gold certification from the U.S. Green Building Council (USGBC). From its robust design to its advanced scientific equipment, RLUOB is essential to the Laboratory's national security mission in support of the National Nuclear Security Administration's (NNSA) nuclear weapons program. At more than 200,000 square feet, this building is the only radiological facility within the Department of Energy to have attained LEED Gold, which contributes to NNSA's achievement towards the high performance sustainable building goals outlined in Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance. 'As we celebrate RLUOB being completed almost one year ahead of schedule and having achieved LEED certification at the Gold level, we approach our plutonium mission at Los Alamos and NNSA with a great sense of achievement,' said Don Cook, NNSA's deputy administrator for defense programs. 'RLUOB adds a major component to NNSA's plutonium support capability and RLUOB demonstrates our commitment in helping to deliver President Obama's nuclear security agenda which includes ensuring the safety, security and effectiveness of the nuclear deterrent without testing.' The facility contains laboratories for analytical chemistry and materials characterization of special nuclear material, along with space for offices, training and emergency operations. Its multi-functional purpose makes RLUOB a unique project for which LEED certification was sought. 'LEED certification was a huge goal and one we sought from the very beginning of this project,' said Laboratory Director Charlie McMillan. 'It's an important step forward, allowing us to advance national security science in modern, safer, more efficient infrastructure.' The Laboratory's project team and its contractor partners, especially in coordination with Jacobs Engineering, focused on green design and construction in LEED categories, such as sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality and innovation in design. RLUOB's features include: (1) Building envelope design (orientation, materials and insulation) yielded a 20 percent improvement in energy performance; (2) Incorporation of building materials with 24 percent recycled content; (3) Diversion of 72 percent of construction-generated materials through reuse, recycle and salvage; (4) Roofing comprised of 93 percent highly-reflective materials to reduce heat island effects; (5) High efficiency, gas-fired hot water boilers, air-cooled chillers, thermal storage systems and variable frequency drives for compressors, fans and pumps; (6) Energy efficient lighting for interiors, exteriors, process glove boxes and fume hoods; (7) Water efficient fixtures resulting in 30 percent reduction in usage; (8) Low emission paints and carpeting for improved indoor air quality; (9) Landscaping that doesn't require permanent irrigation; (10) Enhanced building system commissioning; and (11) Comprehensive transportation alternatives, including public transportation, bicycle storage and changing rooms, and a refueling station for government vehicles using alternative fuels. 'RLUOB's LEED certification demonstrates tremendous leadership in green building,' says Rick Fedrizzi, president and CEO of USGBC. 'The urgency of our mission has challenged the industry to move faster and reach further than ever before, and RLUOB serves as a prime example of just how much we can accomplish.'

25 ENERGY STORAGE↗

Advances in ambient temperature secondary lithium cells

The goal of the NASA/OAST sponsored program on the development of ambient-temperature secondary lithium cells for future space applications is to develop cells with a 100 W h/kg specific energy and capable of 1000 cycles at 50-percent depth of discharge. This paper examines the performance potentials of Li-TiS2, Li-MoS3, Li-V6O13, and Li-NbSe3 electrochemical systems at ambient temperature, together with cycle life and safety characteristics. Of these four, the Li-TiS2 system was found to be the most promising in terms of achievable specific energy and cycle life. Major advances made on the development of secondary lithium cells, which are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly, are summarized.

Subbarao, S.↗