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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Inter-Leaflet Phospholipid Exchange Impacts the Ligand Density Available for Protein Binding at Supported Lipid Bilayers

Phospholipid bilayers formed at solid-liquid interfaces have garnered interest as mimics of cell-membranes to model association reactions of proteins with lipid-bilayer-tethered ligands. Despite the importance of understanding how ligand density in a lipid bilayer impacts the protein-ligand association response, relating the ligand-modified lipid fraction to the absolute density of solution-accessible ligands in a lipid bilayer remains a challenge in interfacial quantitative analysis. In this work, confocal-Raman microscopy is employed to quantify the association of anti-biotin IgG with a small fraction of biotinylated lipids dispersed in either gel-phase or liquid-crystalline supported lipid bilayers, deposited on the interior surfaces of wide-pore silica surfaces. We examine the question whether inter-leaflet lipid translocation contributes to the population of solution-accessible biotin ligands on the distal leaflet of a supported lipid bilayer by comparing their protein accumulation response with ligands dispersed in lipid monolayers on nitrile-derivatized silica surfaces. The binding of antibody to biotin ligands dispersed in gel-phase bilayers exhibited an equivalent biotin-coverage response as the accumulation of IgG onto gel-phase monolayers, indicating that gel-phase bilayer symmetry was preserved. This result contrasts with the ~60% greater anti-biotin capture observed at fluid-phase bilayers compared to fluid-phase monolayers prepared at equivalent biotin fractions. This enhanced protein capture is attributed to biotin-capped lipids being transferred from the surface-associated proximal leaflet of the bilayer to the solution-exposed distal leaflet by the inter-leaflet exchange or lipid flip-flop, a facile process in fluid-phase supported lipid bilayers. Here, the results suggest caution in interpreting the results of quantitative studies of protein binding to lipid-tethered ligands dispersed in fluid-phase phospholipid bilayers.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Supported Platinum Nanoparticles Catalyzed Carbon–Carbon Bond Cleavage of Polyolefins: Role of the Oxide Support Acidity

Supported platinum nanoparticle catalysts are known to convert polyolefins to high-quality liquid hydrocarbons using hydrogen under relatively mild conditions. To date, few studies using platinum grafted onto various metal oxide (M x O y ) supports have been undertaken to understand the role of the acidity of the oxide support in the carbon-carbon bond cleavage of polyethylene under consistent catalytic conditions. Specifically, two Pt/M x O y catalysts (M x O y = SrTiO 3 and SiO 2 -Al 2 O 3 ; Al = 3.0 wt %, target Pt loading 2 wt % Pt similar to 1.5 nm), under identical catalytic polyethylene hydrogenolysis conditions (T = 300 degree celsius, P(H 2 ) = 170 psi, t = 24 h; M w = similar to 3,800 g/mol, M n = similar to 1,100 g/mol, D = 3.45, N branch/100C = 1.0), yielded a narrow distribution of hydrocarbons with molecular weights in the range of lubricants (M w = < 600 g/mol; M n < 400 g/mol; D = 1.5). While Pt/SrTiO 3 formed saturated hydrocarbons with negligible branching, Pt/SiO 2 -Al 2 O 3 formed partially unsaturated hydrocarbons (<1 mol % alkenes and similar to 4 mol % alkyl aromatics) with increased branch density (N branch/100C = 5.5). Further investigations suggest evidence for a competitive hydrocracking mechanism occurring alongside hydrogenolysis, stemming from the increased acidity of Pt/SiO 2 -Al 2 O 3 compared to Pt/SrTiO 3 . Additionally, the products of these polymer deconstruction reactions were found to be independent of the polyethylene feedstock, allowing the potential to upcycle polyethylenes with various properties into a value-added product.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Engineering catalyst supports to stabilize PdO x two-dimensional rafts for water-tolerant methane oxidation

The treatment of emissions from natural gas engines is an important area of research since methane is a potent greenhouse gas. The benchmark catalysts, based on Pd, still face challenges such as water poisoning and long-term stability. In this work, we report an approach for catalyst synthesis that relies on the trapping of metal single atoms on the support surface, in thermally stable form, to modify the nature of further deposited metal/metal oxide. By anchoring Pt ions on a catalyst support we can tailor the morphology of the deposited phase. In particular, two-dimensional (2D) rafts of PdO x are formed, resulting in higher reaction rates and improved water tolerance during methane oxidation. The results show that modifying the support by trapping single atoms could provide an important addition to the toolkit of catalyst designers for controlling the nucleation and growth of metal and metal oxide clusters in heterogeneous catalysts.

2D raft↗
DOE OSTI2023

Workshop on Establishing and Operating a National Nuclear Security Support Centre Hypothetical Scenario: “Centralia Nuclear Security Support Centre Strategy Implementation Plan”

[This is part of a hypothetical scenario-based exercise for workshop participants, based on the fictitious country "Centralia."] In prior years, as a part of efforts to strengthen and better sustain nuclear security within the State, Centralia requested through the Integrated Nuclear Security Support Plan (INSSP) framework that the International Atomic Energy Agency (IAEA) conduct an expert mission on establishing and operating a national nuclear security support centre (NSSC). After the IAEA conducted the NSSC expert mission, members of the Centralia Committee on Nuclear Security (CNS) agreed to initiate the feasibility determination phase of establishing an NSSC, in line with the systematic process recommended by the IAEA. Centralia Nuclear Regulatory Authority (CNRA), as the designated lead organization for coordinating the feasibility determination process, prepared a Feasibility Report in collaboration with members of the CNS and based on input gathered among relevant national stakeholders. The report was presented to the National Security Advisor (NSA), who reviewed and approved the proposal for Centralia to proceed with establishing an NSSC. After Centralia moved into the planning phase for the Centralia Nuclear Security Support Centre (CNSSC), per REF, the primary stakeholders of the centre jointly developed this strategy implementation plan, which provides an outline of the organizational structure, needs analysis, programme objectives, financial and project management, risk management, and other key aspects of the centre. This document will be reviewed and updated as necessary on a semi-annual basis during the project implementation period of establishing CNSSC.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
NASA NTRS1976

Thermal support for scale support

The thermal design work completed for the Thermal Protection System (TPS) of the Space Shuttle System (TPS) of the space shuttle vehicle was documented. This work was divided into three phases, the first two of which reported in previous documents. About 22 separate tasks were completed in phase III, such as: hot gas facility (HGF) support, guarded tank support, shuttle external tank (ET) thermal design handbook support, etc.

Dean, W. G.↗
NASA NTRS1987

Independent Orbiter Assessment (IOA): Analysis of the life support and airlock support subsystems

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Life Support System (LSS) and Airlock Support System (ALSS). Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The LSS provides for the management of the supply water, collection of metabolic waste, management of waste water, smoke detection, and fire suppression. The ALSS provides water, oxygen, and electricity to support an extravehicular activity in the airlock.

Arbet, Jim↗
NASA NTRS1992

System safety activities supporting an aero-space plane ground support technology

An overview is presented of the specific system safety activities required to support the ground support technology program associated with the design of an aerospace plane. Safe zones must be assessed to ensure that explosive safety requirements are attained to protect the vehicle, personnel, and support and operational facilities. Attention is given to the specific and unique design requirements connected with the utilization of cryogenic fuels as they apply to the design and development of an aerospace plane.

Mattern, Steven F.↗
NASA NTRS1993

Mission Operations Support Area (MOSA) for ground network support

The Mission Operations Support Area (MOSA) has been designed utilizing numerous commercial off the shelf items allowing for easy maintenance and upgrades. At its inception, all equipment was at the forefront of technology. The system was created to provide the operator with a 'State of the Art' replacement for equipment that was becoming antiquated and virtually impossible to repair because new parts were no longer available. Although the Mini-NOCC provided adequate support to the Network for a number of years, it was quickly becoming ineffectual for higher data rate and non-standard missions. The MOSA will prove to be invaluable in the future as more and more missions require Ground Network support.

Woods, Robert D.↗
NASA NTRS1995

Influence of backup bearings and support structure dynamics on the behavior of rotors with active supports

Progress made in the current year is listed, and the following papers are included in the appendix: Steady-State Dynamic Behavior of an Auxiliary Bearing Supported Rotor System; Dynamic Behavior of a Magnetic Bearing Supported Jet Engine Rotor with Auxiliary Bearings; Dynamic Modelling and Response Characteristics of a Magnetic Bearing Rotor System with Auxiliary Bearings; and Synchronous Dynamics of a Coupled Shaft/Bearing/Housing System with Auxiliary Support from a Clearance Bearing: Analysis and Experiment.

Flowers, George T.↗
NASA NTRS1995

Prioritization of engineering support requests and advanced technology projects using decision support and industrial engineering models

The evaluation and prioritization of Engineering Support Requests (ESR's) is a particularly difficult task at the Kennedy Space Center (KSC) -- Shuttle Project Engineering Office. This difficulty is due to the complexities inherent in the evaluation process and the lack of structured information. The evaluation process must consider a multitude of relevant pieces of information concerning Safety, Supportability, O&M Cost Savings, Process Enhancement, Reliability, and Implementation. Various analytical and normative models developed over the past have helped decision makers at KSC utilize large volumes of information in the evaluation of ESR's. The purpose of this project is to build on the existing methodologies and develop a multiple criteria decision support system that captures the decision maker's beliefs through a series of sequential, rational, and analytical processes. The model utilizes the Analytic Hierarchy Process (AHP), subjective probabilities, the entropy concept, and Maximize Agreement Heuristic (MAH) to enhance the decision maker's intuition in evaluating a set of ESR's.

Tavana, Madjid↗
NASA NTRS1996

Influence of Back-Up Bearings and Support Structure Dynamics on the Behavior of Rotors With Active Supports

This report presents a synopsis of the research work. Specific accomplishments are itemized below: (1) Experimental facilities have been developed. This includes a magnetic bearing test rig and an auxiliary bearing test rig. In addition, components have been designed, constructed, and tested for use with a rotordynamics test rig located at NASA Lewis Research Center. (2) A study of the rotordynamics of an auxiliary bearing supported T-501 engine model was performed. (3) An experimental/simulation study of auxiliary bearing rotordynamics has been performed. (4) A rotordynamical model for a magnetic bearing supported rotor system, including auxiliary bearing effects has been developed and simulation studies performed.(5) A finite element model for a foil bearing has been developed and studies of a rotor supported by foil bearings have been performed. (6) Two students affiliated with this project have graduated with M.S. degrees.

Flowers, George T.↗
NASA NTRS2005

Verification and Validation of NASA-Supported Enhancements to Decision Support Tools of PECAD

This section of the evaluation report summarizes the verification and validation (V&V) of recently implemented, NASA-supported enhancements to the decision support tools of the Production Estimates and Crop Assessment Division (PECAD). The implemented enhancements include operationally tailored Moderate Resolution Imaging Spectroradiometer (MODIS) products and products of the Global Reservoir and Lake Monitor (GRLM). The MODIS products are currently made available through two separate decision support tools: the MODIS Image Gallery and the U.S. Department of Agriculture (USDA) Foreign Agricultural Service (FAS) MODIS Normalized Difference Vegetation Index (NDVI) Database. Both the Global Reservoir and Lake Monitor and MODIS Image Gallery provide near-real-time products through PECAD's CropExplorer. This discussion addresses two areas: 1. Assessments of the standard NASA products on which these enhancements are based. 2. Characterizations of the performance of the new operational products.

Ross, Kenton W.↗
NASA NTRS2006

Verification and Validation of NASA-Supported Enhancements to PECAD's Decision Support Tools

The NASA Applied Sciences Directorate (ASD), part of the Earth-Sun System Division of NASA's Science Mission Directorate, has partnered with the U.S. Department of Agriculture (USDA) to enhance decision support in the area of agricultural efficiency-an application of national importance. The ASD integrated the results of NASA Earth science research into USDA decision support tools employed by the USDA Foreign Agricultural Service (FAS) Production Estimates and Crop Assessment Division (PECAD), which supports national decision making by gathering, analyzing, and disseminating global crop intelligence. Verification and validation of the following enhancements are summarized: 1) Near-real-time Moderate Resolution Imaging Spectroradiometer (MODIS) products through PECAD's MODIS Image Gallery; 2) MODIS Normalized Difference Vegetation Index (NDVI) time series data through the USDA-FAS MODIS NDVI Database; and 3) Jason-1 and TOPEX/Poseidon lake level estimates through PECAD's Global Reservoir and Lake Monitor. Where possible, each enhanced product was characterized for accuracy, timeliness, and coverage, and the characterized performance was compared to PECAD operational requirements. The MODIS Image Gallery and the GRLM are more mature and have achieved a semi-operational status, whereas the USDA-FAS MODIS NDVI Database is still evolving and should be considered

McKellipo, Rodney↗
NASA NTRS2010

Life Support and Habitation Systems: Crew Support and Protection for Human Exploration Missions Beyond Low Earth Orbit

Life Support and Habitation Systems (LSHS) is one of 10 Foundational Domains as part of the National Aeronautics and Space Administration s proposed Enabling Technology Development and Demonstration (ETDD) Program. LSHS will develop and mature technologies to sustain life on long duration human missions beyond Low Earth Orbit that are reliable, have minimal logistics supply and increase self-sufficiency. For long duration exploration missions, further closure of life support systems is paramount, including focus on key technologies for atmosphere revitalization, water recovery, waste management, thermal control and crew accommodation that recover additional consumable mass, reduce requirements for power, volume, heat rejection, crew involvement, and which have increased reliability and capability. Other areas of focus include technologies for radiation protection, environmental monitoring and fire protection. Beyond LEO, return to Earth will be constrained. The potability of recycled water and purity of regenerated air must be measured and certified aboard the spacecraft. Missions must be able to recover from fire events through early detection, use of non-toxic suppression agents, and operation of recovery systems that protect on-board Environmental Control and Life Support (ECLS) hardware. Without the protection of the Earth s geomagnetic field, missions beyond LEO must have improved radiation shielding and dosimetry, as well as warning systems to protect the crew against solar particle events. This paper will describe plans for the new LSHS Foundational Domain and mission factors that will shape its technology development portfolio.

Barta, Daniel J.↗
NASA NTRS2021

Developing a Sustainable, User-Friendly Literature Database to Support the Microgravity Simulation Support Facility (MSSF) at NASA's Kennedy Space Center (KSC)

Established in 2017, the Microgravity Simulation Support Facility (MSSF) at NASA’s Kennedy Space Center is the only centralized, dedicated facility supporting ground microgravity research in the United States. The MSSF offers the research community the ability to conduct simulated microgravity research with experimental conditions functionally resembling those aboard the International Space Station (ISS) and in other flight-based experimental environments. Since its inception, the MSSF has supported numerous studies and has since collected an extensive library of relevant and pertinent literature. The goal of our research was to develop and implement a sustainable, user-friendly literature database to better house this literature at the MSSF. To achieve this, our team focused on sorting, optimizing, and analyzing preexisting literature libraries to determine a best suitable and sustainable platform for the MSSF. After establishing initial database platforms, the team worked to develop descriptive and structural metadata categories to best sort the literature, which was followed by rigorous testing and optimization of the database as it was implemented. The MSSF has now been outfitted with a reliable, accessible database that effectively houses literature and provides diverse analysis to the user. Our team is continuing to test and update our platform and parameters as we aim for the formal implementation, expansion, and evolution of our database to better sustain future research ventures at the MSSF and beyond.

Database Development↗