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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Development of Material Studies at the LANL UCN Facility Focusing on Actinide Hydriding and Fission Damage

The aging of as-built actinide surfaces in static and dynamic environments is a complex problem of high importance to LANL’s core mission. Many standard material science tools used to study this problem are ideal for highly controlled, lab-made samples. The goal of this work is to use ultracold neutrons to bridge the gap between lab made and as-built surface aging studies. This capability is unique to LANL and will support our core mission.

36 MATERIALS SCIENCE↗
NASA NTRS2007

Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications

Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

Bryant, Robert G.↗
NASA NTRS2019

History of NASA's Determination of Offgassed Products (Test 7)

NASA's Determination of Offgassed Products (Test 7) from materials and assembled articles for spaceflight has evolved since the Apollo program for over 50 years to meet various habitable spacecraft non-metallic programmatic requirements. Now mandated by NASA-STD-6016B Standard Materials and Processes Requirements for Spacecraft, all nonmetallic materials used in habitable flight compartments,with the exception of ceramics, metal oxides, inorganic glasses, and materials used in sealed containers must meet the offgassing requirements of in NASA-STD-6001B Test 7. This manuscript presents the history of Test 7 beginning with the Apollo spacecraft nonmetallic materials selection guidelines and test requirements in 1967

Greene, Benjamin↗
DOE OSTI2019

Determining local thermal transport in a composite uranium-nitride/silicide nuclear fuel using square-pulse transient thermoreflectance technique

Laser-based techniques have become an appealing option for determining the thermal diffusivities (D) and conductivities (k) of nuclear materials that would otherwise prove too hazardous or difficult to measure otherwise. These techniques have enabled non-destructive and non-contact thermal transport measurements with micron-level spatial resolution. In this study, a new time-domain technique known as square-wave pulse thermoreflectance (SPTR) is described and used to determine D values of both uranium sesquisilicide (U 3 Si 2 ) and uranium nitride (UN) phases in a composite fuel. An extensive sensitivity analysis was conducted that identified the optimal measurement parameters of standard materials with a range of thermal transport properties comparable to those of various fuel types. The standards were measured using both SPTR as well as a spatial-domain thermoreflectance technique (SDTR). Several U 3 Si 2 and UN phase regions of polished UN/U 3 Si 2 (70/30 vol.%) samples were measured using both methods, and the resulting calculated D and k values are reported, with both techniques showing excellent agreement between samples. Finally, the ability to use the technique for local diffusivity mapping was demonstrated over a multiphase region, and could be used to determine thermal transport properties in precipitates, secondary phases, and irradiation-damaged regions of post-irradiated fuel samples.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Metal- and covalent-organic frameworks as solid-state electrolytes for metal-ion batteries

Society’s long-standing energy demands have fuelled for centuries the quest for power-dense, portable and economically viable energy carriers. Since the birth of the first rechargeable battery in 1860, emerging battery technologies have provided both answers to these demands as well as additional obstacles. One ubiquitous energy storage device, the metal or metalion battery, offers quintessential examples of both. The strongly reducing nature of Group 1 and 2 metal ions qualifies these elements as viable energy-dense anode materials: standard reduction potentials several volts below that of the standard hydrogen electrode (SHE) allow a thermodynamically favourable oxidation of these metals to readily release electrons that shuttle through an external circuit, generating the electric current that serves as the power supply during battery discharge. Integration of energy-dense materials into devices allows power sources to be compact and portable, by maximizing energy output per unit mass of material. Further, the reversibility of these oxidation events makes possible extensive battery cycling, thus providing a rechargeable power source. Indeed, current Li-ion batteries boast an energy density of 265 Wh kg -1 , with the potential of a 20% improvement, and are operable for over 1000 charge–discharge cycles.

25 ENERGY STORAGE↗
DOE OSTI2020

Initial Temperature Testing of Advanced Manufactured Melt Wire Package

As a part of the In-Pile Instrumentation Program, The Idaho National Laboratory (INL) has recently established in-house capabilities to fabricate and test new advanced manufactured sensors for measuring the peak irradiation temperature inside a nuclear test reactor. Although nuclear test reactors can use standard methods of real-time temperature monitoring, such as thermocouples, the complexity of feedthroughs and attachment complications to collect real-time measurements greatly increases the cost of the experiment. Passive monitoring techniques may be utilized that exploit the melting point of well characterized material (standard melt wires), however, the limited space available for instrumentation during experiments is also a challenge. To accommodate the challenge, INL has expanded its temperature detection instrumentation capabilities paired with the advancement of in-house advanced manufacturing options to include printed melt wires for peak irradiation temperature measurement. The advanced manufactured melt wire package can determine peak temperatures in experiments that can fit the challenging space available during irradiation. Recent results and knowledge from this ongoing work have made it possible to develop unique temperature sensors that can accomplish user specific temperature ranges inside the harsh environments experienced during radiation testing. This report summarizes the initial temperature testing using fabricated melt wires with two different melting temperatures, silver (melting temperature of ~960 °C) and solder (melting temperature of ~160 °C), that were initially tested for their relative melting points using non-standard method of furnace and hot plate testing under normal air conditions. Future work will include more controlled way of testing printed melt wires under inert gas with multiple temperature measurements followed by comparison of standard melt wire package performance for baseline characterization.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

NORM Concentration Determination in Common Materials in an Urban Environment

The United States government performs searches for illicit radiation sources before and during large special events, such as State of the Union addresses, presidential inaugurations, or the recent papal visit. Clear detection of sources is difficult due to natural background radiation, which can vary greatly throughout a given search area. Background radiation is mostly a function of the materials used in roadways, sidewalks, and building exteriors. A team of scientists from Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), the Remote Sensing Laboratory (RSL), and Lawrence Berkeley National Laboratory (LBNL) is exploring the nature and variability of background count rates in order to improve the performance of searches in urban areas. A series of background measurements have been and will continue to be taken at a Military Operations on Urban Terrain (MOUT) environment at the Fort Indiantown Gap (FTIG) National Guard training facility in Pennsylvania. This site replicates a small town with asphalt roads, concrete intersections, buildings, sidewalks, curbs, and gravel parking areas. Unlike an actual urban area, traffic and pedestrian access can be easily controlled to avoid interference with measurements. This paper documents the efforts focused on characterizing the various concentrations of radioactive material found in these materials at the site. The NORM concentrations determined from this work will be incorporated in to a large-scale simulation (a 'virtual test-bed') that can be used to investigate various search techniques and algorithms, detector suite configurations, and to produce representative synthetic data for future work. A combination of measurement and simulation was used to determine the concentration of {sup 40}K and the radioactive nuclides in the uranium series and the thorium series in several materials at the FTIG MOUT site. The predicted concentrations are consistent with other published results, and they matched favorably with synthetic data generated with MCNP6 models using the determined NORM concentrations and estimates of the FTIG environment as described by available construction plans and using standard material assumptions. Future measurements will incorporate lessons learned from this study. More measurements will be made of the concrete intersections at the site. The methodology explained in this report will also be carried out on building materials in an effort to characterize NORM concentrations in these background sources. Other modeling and simulation work that should be conducted includes a robust sensitivity analysis in which the effects of small changes to the model (and measurement) system can be characterized to help bound the uncertainty on the final NORM concentration predictions. (authors)

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Finned-tube-integrated modular thermal storage systems for HVAC load modulation in buildings

While there is considerable focus on latent-based thermal energy storage (TES) systems, the low thermal conductivity of phase change materials (PCMs) remains a critical concern. Many approaches to enhance PCM conductivity either require complicated synthesis processes or are cost prohibitive. In this study, we investigate finned-tube modular TES systems, which are simple in design, easy to manufacture, and cost-effective due to their standard materials and components. The study includes detailed modeling and experimentation of two devices containing similar amounts of PCM but different fin spacings. The study reveals that having more fins does not necessarily increase the TES thermal performance because the reduction in the PCM volume fraction can reduce the TES volumetric and specific energy densities. We find that larger fin spacings provide a higher specific energy for lower C rates (<1C), while smaller fin spacings provide a higher specific energy for higher C rates (>1C).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Status report of advanced cladding modeling work to assess cladding performance under accident conditions

Scoping simulations performed using a severe accident code can be applied to investigate the influence of advanced materials on beyond design basis accident progression and to identify any existing code limitations. In 2012 an effort was initiated to develop a numerical capability for understanding the potential safety advantages that might be realized during severe accident conditions by replacing Zircaloy components in light water reactors (LWRs) with silicon carbide (SiC) components. To this end, a version of the MELCOR code, under development at the Sandia National Laboratories in New Mexico (SNL/NM), was modified by replacing Zircaloy for SiC in the MELCOR reactor core oxidation and material properties routines. The modified version of MELCOR was benchmarked against available experimental data to ensure that present SiC oxidation theory in air and steam were correctly implemented in the code. Additional modifications have been implemented in the code in 2013 to improve the specificity in defining components fabricated from non-standard materials. An overview of these modifications and the status of their implementation are summarized below.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

FIBER LASER CONSTRUCTION AND THEORY INCLUDING FIBER BRAGG GRATINGS Photonic Crystal Fibers (PCFs) and applications of gas filled PCFs

The principles used in fiber lasers have been around for a while but it is only within the past few years that fiber lasers have become commercially available and used in high power laser applications. This paper will focus on the basic design principles of fiber lasers, including fiber Bragg gratings, principles of operation, and forms of non-linear effects. It will describe the type and associated doping of the fiber used and difficult designs used to guide energy from the pump to the active medium. Topics covered include fiber laser design, fiber Bragg gratings, materials used, differences in quantum energy loss, thermo-optical effects, stimulated Raman scattering, Brillouin scattering, photonic crystal fibers and applications of gas filled Photonic Crystal Fibers (PCFs). Thanks to fiber lasers, the energy required to produce high power lasers has greatly dropped and as such we can now produce kW power using a standard 120V 15A circuit. High power laser applications are always requiring more power. The fiber laser can now deliver the greater power that these applications demand. Future applications requiring more power than can be combined using standard materials or configurations will need to be developed to overcome the high energy density and high non-linear optical scattering effects present during high power operations.

47 OTHER INSTRUMENTATION↗
DOE OSTI2016

Characterization of low concentration uranium glass working materials

A series of uranium-doped silicate glasses were created at (Lawrence Livermore National Laboratory) LLNL, to be used as working reference material analogs for low uranium concentration research. Specifically, the aim of this effort was the generation of well-characterized glasses spanning a range of concentrations and compositions, and of sufficient homogeneity in uranium concentration and isotopic composition, for instrumentation research and development purposes. While the glasses produced here are not intended to replace or become standard materials for uranium concentration or uranium isotopic composition, it is hoped that they will help fill a current gap, providing low-level uranium glasses sufficient for methods development and method comparisons within the limitations of the produced glass suite. Glasses are available for research use by request.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1971

Formation of free radicals during mechanical degradation of elastomers.

Solithane 113 (an amorphous polyurethane elastomer) was prepared by curing equal proportions of castor oil and trifunctional isocyanate for 6 hr 45 min at 170 F. The sample material was mechanically degraded by grinding below and above its glass transition point at liquid nitrogen and room temperatures. The EPR spectra of ground samples were recorded and the number of free radicals were determined by a computer double-integration of the recorded spectra and by a comparison of the values with those of a standard material. Curves of EPR spectra suggest that different molecular mechanisms may be active in degradation of this material below and above its glass transition temperature.

Devries, K. L.↗
NASA NTRS2002

Flywheel Rotor Safe-Life Technology

Since the 1960s, research has been conducted into the use of flywheels as energy storage systems. The-proposed applications include energy storage for hybrid and electric automobiles, attitude control and energy storage for satellites, and uninterruptible power supplies for hospitals and computer centers. For many years, however, the use of flywheels for space applications was restricted by the total weight of a system employing a metal rotor. With recent technological advances in the manufacturing of composite materials, however, lightweight composite rotors have begun to be proposed for such applications. Flywheels with composite rotors provide much higher power and energy storage capabilities than conventional chemical batteries. However, the failure of a high speed flywheel rotor could be a catastrophic event. For this reason, flywheel rotors are classified by the NASA Fracture Control Requirements Standard as fracture critical parts. Currently, there is no industry standard to certify a composite rotor for safe and reliable operation forth( required lifetime of the flywheel. Technical problems hindering the development of this standard include composite manufacturing inconsistencies, insufficient nondestructive evaluation (NDE) techniques for detecting defects and/or impact damage, lack of standard material test methods for characterizing composite rotor design allowables, and no unified proof (over-spin) test for flight rotors. As part of a flywheel rotor safe-life certification pro-ram funded b the government, a review of the state of the art in composite rotors is in progress. The goal of the review is to provide a clear picture of composite flywheel rotor technologies. The literature review has concentrated on the following topics concerning composites and composite rotors: durability (fatigue) and damage tolerance (safe-life) analysis/test methods, in-service NDE and health monitoring techniques, spin test methods/ procedures, and containment options. This report presents the papers selected for their relevance to this topic and summarizes them.

Ratner, J. K. H.↗
DOE OSTI2023

Generalized analytical and numerical modeling of optical second harmonic generation in anisotropic crystals and complex heterostructures using #SHAARP package

Optical second harmonic generation (SHG) is a nonlinear optical effect widely used for nonlinear optical microscopy and laser frequency conversion. The closed-form analytical solution of the nonlinear optical responses is essential for evaluating the optical responses of new materials whose optical properties are unknown a priori. Many approximations have therefore been employed in the existing analytical approaches, such as slowly varying approximation, weak reflection of the nonlinear polarization, transparent medium, high crystallographic symmetry, Kleinman symmetry, easy crystal orientation along a high-symmetry direction, phase matching conditions and negligible interference among nonlinear waves, which may lead to large errors in the reported material properties. To avoid these approximations, here we have developed an open-source package named Second Harmonic Analysis of Anisotropic Rotational Polarimetry (#SHAARP) for single interface (si) and in multilayers (ml) for homogeneous crystals. The reliability and accuracy are established by experimentally benchmarking with both the SHG polarimetry and Maker fringes predicted from the package using standard materials. SHAARP.si and SHAARP.ml are available through GitHub https://github.com/Rui-Zu/SHAARP and https://github.com/bzw133/SHAARP.ml, respectively.

complex systems↗
NASA NTRS1985

NASA/aircraft industry standard specification for graphite fiber toughened thermoset resin composite material

A standard specification for a selected class of graphite fiber/toughened thermoset resin matrix material was developed through joint NASA/Aircraft Industry effort. This specification was compiled to provide uniform requirements and tests for qualifying prepreg systems and for acceptance of prepreg batches. The specification applies specifically to a class of composite prepreg consisting of unidirectional graphite fibers impregnated with a toughened thermoset resin that produce laminates with service temperatures from -65 F to 200 F when cured at temperatures below or equal to 350 F. The specified prepreg has a fiber areal weight of 145 g sq m. The specified tests are limited to those required to set minimum standards for the uncured prepreg and cured laminates, and are not intended to provide design allowable properties.

Source record↗
DOE OSTI2016

Dynamic fragmentation of cellular, ice-templated alumina scaffolds

Here, we examine the dynamic failure of ice-templated freeze-cast alumina scaffolds that are being considered as biomimetic hierarchical structures. Three porosities of alumina freeze-cast structures were fabricated, and a systematic variation in microstructural properties such as lamellar width and thickness was observed with changing porosity. Dynamic impact tests were performed in a light-gas gun to examine the failure properties of these materials under high strain-rate loading. Nearly complete delamination was observed following impact, along with characteristic cracking across the lamellar width. Average fragment size decreases with increasing porosity, and a theoretical model was developed to explain this behavior based on microstructural changes. Using an energy balance between kinetic, strain, and surface energies within a single lamella, we are able to accurately predict the characteristic fragment size using only standard material properties of bulk alumina.

36 MATERIALS SCIENCE↗