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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Development of New Type-B Containers and the 'Alternative Approach' Disposal of High-Activity Sealed Sources - 17385

The DOE/NNSA Office of Radiological Security (ORS) is undertaking two projects to enable the recovery and disposal of high-activity sealed sources. First, ORS has completed the development, certification, and fabrication of a new Type B package to support the recovery and transportation of high-activity sources commonly used in irradiators and cancer treatment devices. A second design is currently undergoing certification. The new containers will enable DOE/NNSA shipment of nearly 100 percent of all commercially used devices containing Cs-137 and Co-60, which are particularly significant from a National security, public health, and safety standpoint. Second, ORS and the Conference of Radiation Control Program Directors (CRCPD) Source Collection and Threat Reduction (SCATR) are piloting the commercial disposal of a high-activity device under the NRC's revised guidance on concentration averaging and encapsulation. The Cs-137 blood irradiator is being proposed for disposal at the U.S. Ecology facility in Richland, WA. The project is intended to serve as a model for commercial disposal of similar Class C sources that for decades have been without a commercial disposal pathway. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Significant Roles of Surface Hydrides in Enhancing the Performance of Cu/BaTiO 2.8 H 0.2 Catalyst for CO 2 Hydrogenation to Methanol

Abstract Tuning the anionic site of catalyst supports can impact reaction pathways by creating active sites on the support or influencing metal‐support interactions when using supported metal nanoparticles. This study focuses on CO 2 hydrogenation over supported Cu nanoparticles, revealing a 3‐fold increase in methanol yield when replacing oxygen anions with hydrides in the perovskite support (Cu/BaTiO 2.8 H 0.2 yields ~146 mg/h/gCu vs. Cu/BaTiO 3 yields ~50 mg/h/gCu). The contrast suggests that significant roles are played by the support hydrides in the reaction. Temperature programmed reaction and isotopic labelling studies indicate that BaTiO 2.8 H 0.2 surface hydride species follow a Mars van Krevelen mechanism in CO 2 hydrogenation, promoting methanol production. High‐pressure steady‐state isotopic transient kinetic analysis (SSITKA) studies suggest that Cu/BaTiO 2.8 H 0.2 possesses both a higher density and more active and selective sites for methanol production compared to Cu/BaTiO 3 . An operando high‐pressure diffuse reflectance infrared spectroscopy (DRIFTS)‐SSITKA study shows that formate species are the major surface intermediates over both catalysts, and the subsequent hydrogenation steps of formate are likely rate‐limiting. However, the catalytic reactivity of Cu/BaTiO 2.8 H 0.2 towards the formate species is much higher than Cu/BaTiO 3 , likely due to the altered electronic structure of interface Cu sites by the hydrides in the support as validated by density functional theory (DFT) calculations.

He, Yang↗
DOE OSTI2018

Thermomechanical Modeling of Hydride Materials for Tritium Storage Beds (FY18 Report)

Thermomechanical Modeling of Hydride Materials for Tritium Storage Beds This project aims to develop a fundamental modeling capability suitable for the simulation and assessment of various hydride materials and their associated storage vessels and deuterium/tritium delivery methods. If successful, this work will: • Enhance a core competency of SRNL by adding a unique capability to the tritium processing R&D efforts currently performed for NNSA Defense Programs • Optimize the design and operation of future hydrogen storage technologies in anticipation of increased demands and the call for a robust, reliable, resilient, and responsive stockpile • Establish SRNL as a valuable analytic resource for DOE and DoD decision makers and the foreign technology assessment community, which has already shown significant interest in developing such models to assess the likelihood and feasibility of alternative foreign gas (deuterium/tritium) storage and delivery systems that might provide new technical pathways for the U.S. and to determine the performance of alternative foreign systems.

36 MATERIALS SCIENCE↗
NASA NTRS2014

An Approach for Performance Assessments of Extravehicular Activity Gloves

The Space Suit Assembly (SSA) Development Team at NASA Johnson Space Center has invested heavily in the advancement of rear‐entry planetary exploration suit design but largely deferred development of extravehicular activity (EVA) glove designs, and accepted the risk of using the current flight gloves, Phase VI, for unique mission scenarios outside the Space Shuttle and International Space Station (ISS) Program realm of experience. However, as design reference missions mature, the risks of using heritage hardware have highlighted the need for developing robust new glove technologies. To address the technology gap, the NASA Game‐Changing Technology group provided start‐up funding for the High Performance EVA Glove (HPEG) Project in the spring of 2012. The overarching goal of the HPEG Project is to develop a robust glove design that increases human performance during EVA and creates pathway for future implementation of emergent technologies, with specific aims of increasing pressurized mobility to 60% of barehanded capability, increasing the durability by 100%, and decreasing the potential of gloves to cause injury during use. The HPEG Project focused initial efforts on identifying potential new technologies and benchmarking the performance of current state of the art gloves to identify trends in design and fit leading to establish standards and metrics against which emerging technologies can be assessed at both the component and assembly levels. The first of the benchmarking tests evaluated the quantitative mobility performance and subjective fit of two sets of prototype EVA gloves developed ILC Dover and David Clark Company as compared to the Phase VI. Both companies were asked to design and fabricate gloves to the same set of NASA provided hand measurements (which corresponded to a single size of Phase Vi glove) and focus their efforts on improving mobility in the metacarpal phalangeal and carpometacarpal joints. Four test subjects representing the design‐to hand anthropometry completed range of motion, grip/pinch strength, dexterity, and fit evaluations for each glove design in pressurized conditions, with and without thermal micrometeoroid garments (TMG) installed. This paper provides a detailed description of hardware and test methodologies used and lessons learned.

Aitchison, Lindsay↗
DOE OSTI2018

A roadmap for nuclear energy technology

The prospects for the future use of nuclear energy worldwide can best be understood within the context of global population growth, urbanization, rising energy need and associated pollution concerns. As the world continues to urbanize, sustainable development challenges are expected to be concentrated in cities of the lower-middle-income countries where the pace of urbanization is fastest. As these countries continue their trajectory of economic development, their energy need will also outpace their population growth adding to the increased demand for electricity. OECD IEA’s energy system deployment pathway foresees doubling of the current global nuclear capacity by 2050 to reduce the impact of rapid urbanization. The pending “retirement cliff” of the existing U.S. nuclear fleet, representing over 60 percent of the nation’s emission-free electricity, also poses a large economic and environmental challenge. To meet the challenge, the U.S. DOE has developed the vision and strategy for development and deployment of advanced reactors. As part of that vision, the U.S. government pursues programs that aim to expand the use of nuclear power by supporting sustainability of the existing nuclear fleet, deploying new water-cooled large and small modular reactors to enable nuclear energy to help meet the energy security and climate change goals, conducting R&D for advanced reactor technologies with alternative coolants, and developing sustainable nuclear fuel cycle strategies. Since the current path relying heavily on water-cooled reactors and “once-through” fuel cycle is not sustainable, next generation nuclear energy systems under consideration aim for significant advances over existing and evolutionary water-cooled reactors. Among the spectrum of advanced reactor options, closed-fuel-cycle systems using reactors with fast-neutron spectrum to meet the sustainability goals offer the most attractive alternatives. However, given these circumstances, unless the new public-private partnership models emerge to tackle the licensing and demonstration challenges for these advanced reactor concepts, realization of their enormous potential is not likely, at least in the U.S.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
NASA NTRS2003

Pathways to Colonization

The steps required for space colonization are many to grow from our current 3-person International Space Station, now under construction, to an infrastructure that can support hundreds and eventually thousands of people in space. This paper will summarize the author's findings from numerous studies and workshops on related subjects and identify some of the critical next steps toward space colonization. Findings will be drawn from the author s previous work on space colony design, space infrastructure workshops, and various studies that addressed space policy. In conclusion, this paper will note that significant progress has been made on space facility construction through the International Space Station program, and that significant efforts are needed in the development of new reusable Earth to Orbit transportation systems. The next key steps will include reusable in space transportation systems supported by in space propellant depots, the continued development of inflatable habitat and space elevator technologies, and the resolution of policy issues that will establish a future vision for space development.

Smitherman, David V., Jr.↗
DOE OSTI2016

Mesoporous MoO 3– x Material as an Efficient Electrocatalyst for Hydrogen Evolution Reactions

A unique approach for the synthesis of nonstoichiometric, mesoporous molybdenum oxide (MoO 3– x ) with nanosized crystalline walls by using a soft template (PEO‐ b ‐PS) synthesis method is introduced. The as‐synthesized mesoporous MoO 3– x is very active and stable (durability > 12 h) for the electrochemical hydrogen evolution reaction (HER) under both acidic and alkaline conditions. The intrinsic MoO 3 serves as an HER electrocatalyst without the assistance of carbon materials, noble metals, or MoS 2 materials. The results from transmission electron microscopy and N 2 sorption techniques show that the as‐synthesized mesoporous MoO 3– x has large accessible pores (20–40 nm), which are able to facilitate mass transport and charge transfer during HER. In terms of X‐ray diffraction, X‐ray photoelectron spectroscopy, temperature‐programmed oxidation, and diffusive reflectance UV–vis spectroscopy, the mesoporous MoO 3– x exhibits mixed oxidation states (Mo 5+ , Mo 6+ ) and an oxygen‐deficient structure. The as‐synthesized MoO 3– x only requires a low overpotential (≈0.14 V) to achieve a 10 mA cm −2 current density in 0.1 m KOH and the Tafel slope is as low as 56 mV dec −1 . Density functional theory calculations demonstrate a change of electronic structure and the possible reaction pathway of HER. Oxygen vacancies and mesoporosity serve as key factors for excellent performance.

Luo, Zhu↗
DOE OSTI2013

Fluid geochemistry at the Raft River geothermal field, Idaho, USA: New data and hydrogeological implications

Following a period of exploration and development in the mid-late 1970’s, there was little activity at the Raft River geothermal field for the next ~20 years. U.S. Geothermal Inc. acquired the project in 2002, and began commercial power generation in January 2008. From mid-2004 to present, U.S. Geothermal Inc. has collected geochemical data from geothermal and monitoring wells in the field, as well as other shallow wells in the area. An additional sampling program was completed in July 2010 to measure a wider range of trace elements and key water isotopes (δ 18 O, δD, and 3 H (Tritium)) in the field. The data indicate that the fluid geochemistry in the field is spatially variable and complex, with two distinct deep geothermal fluid types (high vs. low K, Na, Cl, Ca, Li, F concentrations) and two groundwater fluid types. These differences have been interpreted to reflect deep structural controls on fluid pathways in the field, which has compartmentalized the fluids and limited the degree of mixing between them.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Confinement of Lewis Acid–Base Sites by Microporous Silica Layers on Titania for Enhanced Alkanol Dehydration Reactivity

Alkanol dehydration offers a pathway to upgrade biomass-derived short-chain oxygenates into alkenes, essential chemical building blocks widely used in industrial applications. Transition metal oxides with Lewis acid-base site pairs are attractive catalysts due to their high reactivity and cost-effectiveness. This work demonstrates a synthetic pathway to manipulate local environments around active Lewis acid-base pairs in anatase TiO 2 to enhance their reactivity in alkanol dehydration. Microporous SiO 2 layers with an average pore diameter of ~0.6 nm and a controlled thickness of 0.8-33 nm are deposited on anatase TiO 2 powders by using a molecular templated SiO 2 deposition method. The Lewis acid-base strength of accessible Ti-O pairs remains unchanged, as shown by temperature-programmed surface reactions of surface-bound formic acid-derived species and temperature-programmed desorption of pyridine. However, measured alkanol dehydration rates on confined Ti-O pairs are much higher (by up to 7-fold) than those on TiO 2 . The extent of rate enhancements depends on the reactant size and functional group positioning, suggesting that the rate enhancements reflect the interactions between the guest molecules (reactants and transition states) and the surrounding SiO 2 micropore environments. By providing a detailed synthetic procedure to tailor the local environments around active sites in bulk oxides, this approach offers an additional avenue for enhancing catalytic performance.

09 BIOMASS FUELS↗
NASA NTRS2012

Benchmarking Evaluation Results for Prototype Extravehicular Activity Gloves

The Space Suit Assembly (SSA) Development Team at NASA Johnson Space Center has invested heavily in the advancement of rear-entry planetary exploration suit design but largely deferred development of extravehicular activity (EVA) glove designs, and accepted the risk of using the current flight gloves, Phase VI, for unique mission scenarios outside the Space Shuttle and International Space Station (ISS) Program realm of experience. However, as design reference missions mature, the risks of using heritage hardware have highlighted the need for developing robust new glove technologies. To address the technology gap, the NASA Game-Changing Technology group provided start-up funding for the High Performance EVA Glove (HPEG) Project in the spring of 2012. The overarching goal of the HPEG Project is to develop a robust glove design that increases human performance during EVA and creates pathway for future implementation of emergent technologies, with specific aims of increasing pressurized mobility to 60% of barehanded capability, increasing the durability by 100%, and decreasing the potential of gloves to cause injury during use. The HPEG Project focused initial efforts on identifying potential new technologies and benchmarking the performance of current state of the art gloves to identify trends in design and fit leading to establish standards and metrics against which emerging technologies can be assessed at both the component and assembly levels. The first of the benchmarking tests evaluated the quantitative mobility performance and subjective fit of four prototype gloves developed by Flagsuit LLC, Final Frontier Designs, LLC Dover, and David Clark Company as compared to the Phase VI. All of the companies were asked to design and fabricate gloves to the same set of NASA provided hand measurements (which corresponded to a single size of Phase Vi glove) and focus their efforts on improving mobility in the metacarpal phalangeal and carpometacarpal joints. Four test subjects representing the design ]to hand anthropometry completed range of motion, grip/pinch strength, dexterity, and fit evaluations for each glove design in both the unpressurized and pressurized conditions. This paper provides a comparison of the test results along with a detailed description of hardware and test methodologies used.

Aitchison, Lindsay↗
NASA NTRS2020

Airborne Science Mission Capabilities of the NASA DC-8 and Possible Alternative Aircraft

Age-related concerns associated with operating the 50-year-old NASA Airborne Science Program DC-8 Flying Laboratory aircraft are raising concerns about the prospects of someday retiring the NASA DC-8. Given that eventuality, this study examines how current and anticipated science requirements can be incorporated with aeronautical performance and cost metrics for assessing, comparing, and down-selecting candidate replacement aircraft. A literature review of NASA DC-8 missions and interviews with current DC-8 science users provides context for the initial phase of this study and offers a pathway for collecting aircraft specifications. Performance models are developed and calibrated against published range-payload data for various mission fuel and payload weight combinations. The models are extended to three airborne science missions, with payload weights ranging from 30,000-52,000 lb and mission ranges up to 5,050 nmi. Results point towards the 767-200ER aircraft as a top contender offering a bit more experimenter floor-space, payload capacity, and range than the NASA DC-8, and to the U.S. Navy P-8 aircraft as a viable option offering perhaps not too much less of those items, with the relative benefit of using less fuel per mission.

Thomas A Ozoroski↗
DOE OSTI2018

Intraocular miR-211 exacerbates pressure-induced cell death in retinal ganglion cells via direct repression of FRS2 signaling

Highlights: • miR-211 expression is upregulated in aqueous humor samples from glaucoma patients. • Oxidative stress induces miR-211 expression in retinal ganglion cells (RGCs). • miR-211 potentiates high pressure-induced RGCs death via distinct MAPK pathways. • miR-211 directly targets Frs2 3′UTR in RGCs. MicroRNAs (miRNAs) are emerging as important regulators of neurodegenerative diseases. However, research into ocular intracellular miRNAs, though possessing great potential to uncover novel and valuable therapeutic targets for glaucoma, is only at an early stage. Here we show that expression levels of miR-211 were significantly induced in aqueous humor (AH) samples from patients with glaucoma when compared to normal AH samples. Notably, oxidative stress-elicited miR-211 potentiated high pressure-induced retinal ganglion cells (RGCs) death by impairing ERK activation but enhancing P38 activation, an effect mediated by direct downregulation of fibroblast growth factor receptor substrate 2 (Frs2) signaling pathway in a sequence complementarity-dependent fashion. In support of the concept of a fundamental connection between miR-211 upregulation and augmented pressure-induced cell death in RGCs, we showed that ectopic expression of the exogenous FRS2 was sufficient to neutralize the miR-211-induced decrease in the cell viability and significantly improved miR-211-inhibited cell survival, in high pressure-challenged RGC-5 cells. Together, our findings show that miR-211 negatively modulates cell survival programs upon high pressure challenge by regulating Frs2 signaling, and they define roles for miR-211/Frs2 cascade in a regulatory feedback loop that mediates the pathogenesis of glaucoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Site-Specific Imaging of Elemental Steps in Dehydration of Diols on TiO 2 (110)

The conversion of diols on partially reduced TiO 2 (110) at low coverage was studied using variable-temperature scanning tunneling microscopy, temperature programmed desorption and density functional theory calculations. We find, that below ~230 K, ethane-1,2-diol and propane-1,3-diol molecules adsorb predominantly on five-fold coordinated Ti5c atoms. The dynamic equilibrium between molecularly bound and dissociated species resulting from O-H bond scission and reformation is observed. As the diols start to diffuse on the Ti5c rows above ~230 K, they dissociate irreversibly upon encountering bridging oxygen (O b ) vacancy (VO’s) defects. Two dissociation pathways, one via O-H and the other via C-O bond scission leading to identical surface intermediates, hydroxyalkoxy, O b -(CH 2 )n-OH (n = 2, 3) and bridging hydroxyl, HO b , are seen. For O-H bond scission, the O b -(CH 2 )n-OH is found on the position of the original VO, while for C-O scission it is found on the adjacent Ob site. Theoretical calculations suggest that the observed mixture of C-O/O-H bond breaking processes are a result of the steric factors enforced upon the diols by the second OH group that is bound to a Ti5c site. At room temperature, rich dissociation/reformation dynamics of the second, Ti5c-bound O-H leads to the formation of dioxo, Ob-(CH 2 )n-OTi, species. Above ~400 K, both O b -(CH 2 )n-OH and Ob-(CH 2 )n-OTi species convert into a new intermediate, that is centered on Ob row. Combined experimental and theoretical evidence shows that this intermediate is most likely a new dioxo, O b -(CH 2 ) 2 -Ob, species. Further annealing leads to sequential C-Ob bond cleavage and alkene desorption above ~ 500 K. Simulations find that the sequential C-O bond breaking process follows a homolytic diradical pathway with the first C-O bond breaking event accompanied by a non-adiabatic electron transfer within the TiO 2 (110) substrate.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2000

Shape-dependent control of cell growth, differentiation, and apoptosis: switching between attractors in cell regulatory networks

Development of characteristic tissue patterns requires that individual cells be switched locally between different phenotypes or "fates;" while one cell may proliferate, its neighbors may differentiate or die. Recent studies have revealed that local switching between these different gene programs is controlled through interplay between soluble growth factors, insoluble extracellular matrix molecules, and mechanical forces which produce cell shape distortion. Although the precise molecular basis remains unknown, shape-dependent control of cell growth and function appears to be mediated by tension-dependent changes in the actin cytoskeleton. However, the question remains: how can a generalized physical stimulus, such as cell distortion, activate the same set of genes and signaling proteins that are triggered by molecules which bind to specific cell surface receptors. In this article, we use computer simulations based on dynamic Boolean networks to show that the different cell fates that a particular cell can exhibit may represent a preprogrammed set of common end programs or "attractors" which self-organize within the cell's regulatory networks. In this type of dynamic network model of information processing, generalized stimuli (e.g., mechanical forces) and specific molecular cues elicit signals which follow different trajectories, but eventually converge onto one of a small set of common end programs (growth, quiescence, differentiation, apoptosis, etc.). In other words, if cells use this type of information processing system, then control of cell function would involve selection of preexisting (latent) behavioral modes of the cell, rather than instruction by specific binding molecules. Importantly, the results of the computer simulation closely mimic experimental data obtained with living endothelial cells. The major implication of this finding is that current methods used for analysis of cell function that rely on characterization of linear signaling pathways or clusters of genes with common activity profiles may overlook the most critical features of cellular information processing which normally determine how signal specificity is established and maintained in living cells. Copyright 2000 Academic Press.

Review↗
DOE OSTI2021

Search for New Isotope Production Pathways

The isotope group at Jefferson Lab is carrying out R&D for producing medically interesting radioisotopes, especially those with theranostic (therapeutic and diagnostic) attributes. Here the search for viable production mechanisms has been expanded to multi-step reactions where a daughter is produced from the target and decays into a medically interesting granddaughter radioisotope. It is difficult to find efficient production routes when investigating both the initial excitation reaction as well as the decay routes leading to medically interesting isotopes. The overall goal of this project is to create a structured code in Python to find these decay routes by automatically exploring the large number of isotopes and their possible decay modes. The program structure is described, and preliminary results are presented.

Dabill, L.↗
DOE OSTI2018

Species-Selective Pyrimidineamine Inhibitors of Trypanosoma brucei S-Adenosylmethionine Decarboxylase

New therapeutic options are needed for treatment of human African trypanosomiasis (HAT) caused by protozoan parasite Trypanosoma brucei. S-Adenosylmethionine decarboxylase (AdoMetDC) is an essential enzyme in the polyamine pathway of T. brucei. Previous attempts to target this enzyme were thwarted by the lack of brain penetration of the most advanced series. In this study, we describe a T. brucei AdoMetDC inhibitor series based on a pyrimidineamine pharmacophore that we identified by target-based high-throughput screening. The pyrimidineamines showed selectivity for T. brucei AdoMetDC over the human enzyme, inhibited parasite growth in whole-cell assay, and had good predicted blood–brain barrier penetration. The medicinal chemistry program elucidated structure–activity relationships within the series. Features of the series that were required for binding were revealed by determining the X-ray crystal structure of TbAdoMetDC bound to one analog. The pyrimidineamine series provides a novel starting point for an anti-HAT lead optimization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and other contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in the subsurface; a primary concern of the DOE Environmental Remediation Science Division (ERSD) and Subsurface Geochemical Research (SBR) Program.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗