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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Weather satellite picture receiving stations, APT digital scan converter

The automatic picture transmission digital scan converter is used at ground stations to convert signals received from scanning radiometers to data compatible with ground equipment designed to receive signals from vidicons aboard operational meteorological satellites. Information necessary to understand the circuit theory, functional operation, general construction and calibration of the converter is provided. Brief and detailed descriptions of each of the individual circuits are included, accompanied by a schematic diagram contained at the end of each circuit description. Listings of integral parts and testing equipment required as well as an overall wiring diagram are included. This unit will enable the user to readily accept and process weather photographs from the operational meteorological satellites.

Vermillion, C. H.↗
NASA NTRS1981

NASA/BLM Applications Pilot Test (APT), phase 2. Volume 1: Executive summary

Data from LANDSAT, low altitude color aerial photography, and ground visits were combined and used to produce vegetation cover maps and to estimate productivity of range, woodland, and forest resources in northwestern Arizona. A planning session, two workshops, and four status reviews were held to assist technology transfer from NASA. Computer aided digital classification of LANDSAT data was selected as a major source of input data. An overview is presented of the data processing, data collection, productivity estimation, and map verification techniques used. Cost analysis and digital LANDSAT digital products are also considered.

Source record↗
NASA NTRS1981

NASA/BLM APT, phase 2. Volume 2: Technology demonstration

Techniques described include: (1) steps in the preprocessing of LANDSAT data; (2) the training of a classifier; (3) maximum likelihood classification and precision; (4) geometric correction; (5) class description; (6) digitizing; (7) digital terrain data; (8) an overview of sample design; (9) allocation and selection of primary sample units; (10) interpretation of secondary sample units; (11) data collection ground plots; (12) data reductions; (13) analysis for productivity estimation and map verification; (14) cost analysis; and (150) LANDSAT digital products. The evaluation of the pre-inventory planning for P.J. is included.

Source record↗
NASA NTRS1981

NASA/BLM Applications Pilot Test (APT), phase 2. Volume 3: Technology transfer

Techniques used and materials presented at a planning session and two workshops held to provide hands-on training in the integration of quantitatively based remote sensing data are described as well as methods used to enhance understanding of approaches to inventories that integrate multiple data sources given various resource information objectives. Significant results from each of the technology transfer sessions are examined.

Source record↗
NASA NTRS1985

Automated Portable Test System (APTS) - A performance envelope assessment tool

The reliability and stability of microcomputer-based psychological tests are evaluated. The hardware, test programs, and system control of the Automated Portable Test System, which assesses human performance and subjective status, are described. Subjects were administered 11 pen-and-pencil and microcomputer-based tests for 10 sessions. The data reveal that nine of the 10 tests stabilized by the third administration; inertial correlations were high and consistent. It is noted that the microcomputer-based tests display good psychometric properties in terms of differential stability and reliability.

Kennedy, R. S.↗
NASA NTRS1996

Aeropropulsion Technology (APT). Task 23 - Stator Seal Cavity Flow Investigation

The focus of NASA Contract NAS3-25950 Task 23 was to numerically investigate the flow through an axial compressor inner-banded stator seal cavity. The Allison/NASA developed ADPAC code was used to obtain all flow predictions. Flow through a labyrinth stator seal cavity of a high-speed compressor was modeled by coupling the cavity flow path and the main flow path of the compressor. A grid resolution study was performed to guarantee adequate grid spacing was used. Both unsteady rotor-stator-rotor interactions and steady-state isolated blade calculations were performed with and without the seal cavity present. A parameterized seal cavity study of the high-speed stator seal cavity collected a series of solutions for geometric variations. The parameter list included seal tooth gap, cavity depth, wheel speed, radial mismatch of hub flowpath, axial trench gap, hub corner treatments, and land edge treatments. Solution data presented includes radial and pitchwise distributions of flow variables and particle traces describing the flow character.

Heidegger, N. J.↗
NASA NTRS2003

Aero-Propulsion Technology (APT) Task V Low Noise ADP Engine Definition Study

A study was conducted to identify and evaluate noise reduction technologies for advanced ducted prop propulsion systems that would allow increased capacity operation and result in an economically competitive commercial transport. The study investigated the aero/acoustic/structural advancements in fan and nacelle technology required to match or exceed the fuel burned and economic benefits of a constrained diameter large Advanced Ducted Propeller (ADP) compared to an unconstrained ADP propulsion system with a noise goal of 5 to 10 EPNDB reduction relative to FAR 36 Stage 3 at each of the three measuring stations namely, takeoff (cutback), approach and sideline. A second generation ADP was selected to operate within the maximum nacelle diameter constrain of 160 deg to allow installation under the wing. The impact of fan and nacelle technologies of the second generation ADP on fuel burn and direct operating costs for a typical 3000 nm mission was evaluated through use of a large, twin engine commercial airplane simulation model. The major emphasis of this study focused on fan blade aero/acoustic and structural technology evaluations and advanced nacelle designs. Results of this study have identified the testing required to verify the interactive performance of these components, along with noise characteristics, by wind tunnel testing utilizing and advanced interaction rig.

Holcombe, V.↗
NASA NTRS2005

New Aptes Cross-linked Polymers from Poly(ethylene oxide)s and Cyanuric Chloride for Lithium Batteries

A new series of polymer electrolytes for use as membranes for lithium batteries are described. Electrolytes were made by polymerization between cyanuric chloride and diamino-terminated poly(ethylene oxide)s, followed by cross-linking via a sol-gel process. Thermal analysis and lithium conductivity of freestanding polymer films were studied. The effects of several variables on conductivity were investigated, such as length of backbone PEO chain, length of branching PEO chain, extent of branching, extent of cross-linking, salt content, and salt counterion. Polymer films with the highest percentage of PEO were found to be the most conductive, with a maximum lithium conductivity of 3.9 x 10(exp -5) S/cm at 25 C. Addition of plasticizer to the dry polymers increased conductivity by an order of magnitude.

Tigelaar, Dean M.↗
NASA NTRS2007

Composite Electrolytes for Lithium Batteries: Ionic Liquids in APTES Crosslinked Polymers

Solvent free polymer electrolytes were made consisting of Li(+) and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and crosslinked by a sol-gel process to provide mechanical strength. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer.

Tigelaar, Dean M.↗
NASA NTRSDate not supplied

Micrometer to Atomic Scale Characterisation of Primitive Astromaterials Using A Novel Method, Metis-Fa: A Coordinated Atom Probe Tomography, Transmission Electron Microscopy and NanoSIMS Approach

Introduction: Presolar grains preserve isotopic, chemical and microstructural records of physical and chemical processing, and formation mechanisms within a vast range of evolved stellar systems, the interstellar medium, solar nebula and their parent bodies. These evolutionary records are preserved at the micrometric to atomic scale, requiring coordinated studies to expand our understanding of evolutionary processes occurringthroughout ours and external stellar systems [1]. NanoSIMS enabled rapid in situ identification and isotopic characterisation of presolar grains and their stellar origins using 17O/16O and 18O/16O, and 13C/12C isotopic ratios [1]. Coordination with transmission electron microscopy (TEM) revealed crystallographic and localised contextual relationships and quantitively constrained their major and minor compositions [1]. However, trace elements cannot be quantified, the most sensitive geochemical tracers of environmental conditions, essential to unravelling the chemical record of their evolutionary pathway and parent stellar systems [2-3] . Furthermore, owing to the combination of technical limitations (only 5 – 7 isotopes can be measured per NanoSIMS run) and their small grain sizes of 100 nm < 3 μm (with rare exceptions in nanodiamonds (2 nm ≤) and SiC (< 40 μm)), the number of measurable isotopes per grain volume is limited [1,3] . Through more comprehensive isotopic studies of presolar grains, NanoSIMS studies have shown the importance of the latter, identifying Fe and Mg as important indicators of nuclear synthetic processing and their stellar origins, respectively [4- 5]. Coordination of NanoSIMS and Atom Probe Tomography (APT) revealed morphological signatures, and isotopic and chemical signatures at major to trace levels without requirements for preselection of elements [6]. However, crystallographic signatures in localized contextual relationships cannot be measured. Consequently, coordination of NanoSIMS, TEM and APT is essential to gain access to almost all contextual, structural and geochemical signatures within each presolar grain.Transmission electron microscopy requires a 100 nm thin lamella which is unstable in APT and would not produce any viable data. Atom probe tomography requires a needle-shaped specimen which when measured in TEM removes the local context, impacts the quality of the TEM diffraction images due to the shank angle of the needle, and can alter the chemistry of beam sensitive materials from the higher degree of surface exposure at the tip. To address these issues, we developed METIS-Fa (Multi-technical measurements of Electron Transparent materials using an Indium Sandwich - a FIB approach). A novel method which enables coordination of NanoSIMS, TEM and APT for generalized and targeted studies of individual grains, including beam sensitive materials, without compromising sample preparation requirements for TEM and APT. This method requires only indium and a Focus Ion Beam (FIB), minimizing the movement of fragile materials while still enabling preparation of TEM lamella into APT needles. Samples: Initial experimental development and testing of the method occurred at Astromaterials Research and Exploration Science (ARES), Johnson Space Centre (JSC), NASA and APT measurements and needle preparation occurred at JdLC, Curtin University. Synthetic silicate samples were used as analogs for presolar silicates when performing a trial run of the method. Samples were extracted from a polished thin section created at JSC, NASA, comprised of 38 wt.% Si, 17 wt.% FeO, 13 wt.% MgO, 12 wt.% Al, 11 wt.% Ca based on electron microprobe analysis (EMPA) [8] . Experimental details, pressure and temperature conditions were presented in [8] and references therein. Testing of the capability to target individual grains in mineral matrices using this method for acquisition in APT, measured matrix regions in meteoritic thin sections of primitive meteorites. These meteorites and their identified presolar grains for future targeted studies are detailed in [9]. Techniques: The TEM-FIB lamella were prepared using a FIB. An e-beam assisted pt deposition was used as a protective coating for the synthetic and meteoritic samples. When targeting individual grains, a secondary e-beam assisted pt deposition button is placed over the desired grain before the protective coating to denote its location. A JEOL 2500SE field-emission TEM was used for high-resolution imaging, energy-dispersive X-ray (EDX) and electron diffraction data.TheMETIS-Fa method was experimentally designed, tested and executed using a FIB at ARES, JSCNASA. Needles for APT were prepared using the Tescan Lyra3 GM Dual Beam Focus Ion Beam (FIB) Field Emission SEM (FE-SEM) at the JdLC, Curtin University. Atom probe tomography measurements were conducted using a CAMECA Local Electrode Atom Probe, LEAP 4000X HR. Two pure indium needles were analyzed initially to constraining acquisition parameters and stability under the beam. Manual acquisition was required to maintain evaporation of specimen’s at the apex and monitor interactions with measurement parameters. Experimental Design: Indium foil is pressed onto an Al stub with a pneumatic press and mounted into the FIB adjacent to the TEM-FIB lamella of interest. Using a FIB, two indium slices (5 μm x ~300 nm x 3 μm) are extracted from indium foil and aligned with the TEM-FIB lamella before touching the TEM-FIB lamella. Each slice is then attached through cold welding to the FIB-TEM lamella. This approach eliminates the need for chemical treatments and proved effective for aligning the Indium within the region of interest for APT, holding it in place for up to 4 days during testing.Once both indium slices are attached within their pre-determined region per grain targeting requirements, they are gradually melted onto the FIB-TEM lamella.When targeting a specific grain, measurements should be taken of the pt button and its distance from edge to edge of the lamella before and after sandwiching. A secondary button should be placed over the same region after the Indium slices have been attached to improve precision when preparing APT needles. Results: Figure 1 shows two indium slices melted onto a FIB-TEM lamella, adding additional bulk for preparation into APT needles as shown in Figure 2 [7] . The latter was essential so samples could be measured in TEM and APT without compromising sample preparation requirements and consequently data quality and acquisition stability. METIS-Fa proved effective forimproving geometry. Figure 3 shows a successful APTrun of the synthetic silicate. EMPA, TEM and APTshowed no chemical alterations. During targetingtesting, a solar silicate grain was successfully identifiedand measured in TEM, and prepared into an APTneedle. However, the indium was melted too long during sample preparation, causing expansion andformation of internal porosity leading to sample loss.Conclusion: METIS-Fa greatly expands the number of isotopic and chemical signatures measured per grain volume, and enables measurements of contextual, structural, crystallographic, isotopic and geochemical signatures within individual grains. Gaining access to such a vast range of evolutionary signatures required for expanding our understanding of external stellar and planetary systems and the evolution of our solar system. This method was designed for application to a vast range of phases including being sensitive materials and thus provides a way for coordination of NanoSIMS, TEM and APT not just for the study of presolar grains and by extension primitive astromaterials, but studies in a vast range of other fields including the geosciences and material sciences.Acknowledgments: Thankyou to ARES, JSC, NASA; JdLC Curtin University and Space Science Technology Centre for the use of laboratory facilities and funding [confirm].

Nicole D Nevill↗
NASA NTRSDate not supplied

A New Coordinated NanoSIMS, Transmission Electron Microscopy and Atom Probe Tomography Approach For the Characterization of Primitive Astromaterials

Presolar grains are remnants of evolved stellar systems preserved within primitive extraterrestrial materials. They are important for studying physical and chemical processing, and formation mechanisms occurring within the interstellar medium, Solar Nebula and their parent stellar environments [1]. Our recent work has shown coordinated nano-scale Secondary Ion Mass Spectrometry (NanoSIMS) and Atom Probe Tomography (APT) can show isotopic and chemical signatures at major to trace levels, morphological signatures, and regional contextual relationships [2,3]. Previous studies have shown Transmission Electron Microscopy (TEM) of Focus Ion Beam (FIB) TEM lamella, can provide localized contextual relationships, crystallographic information and chemical information [1]. Coordinating NanoSIMS, TEM, and APT could gain access to almost all contextual, structural and geochemical signatures within each presolar grain. However, this has proved challenging owing to the preparation requirements for TEM and APT. For example, studying specimen prepared as APT needles in TEM removes the local context, the higher degree of surface exposure can alter the chemistry of beam sensitive materials, and the shank angle of the needle can impact the quality of TEM diffraction images. We designed a new FIB method which takes a 100 nm thick FIB-TEM lamella and sandwiches it between two indium slices (5 μm x ~300 nm x 3 μm). The indium is melted onto the lamella surface using the electron beam (Fig 1). This process adds bulk to the lamella, making it more amenable to APT needle formation (Fig 2). Consequently, samples can be prepared per the optimal requirements for each technique improving data quality, acquisition stability, and access to the signatures and relationships summarised earlier. This technique can be used for measuring multiple phases across a TEM lamella and targeting an individual phase. For example, a presolar grain identified in NanoSIMS could be targeted, studied in TEM and then indium sandwiched with its precise location in the TEM lamella marked using a Pt button for preparation of an APT needle and atomic scale acquisition. [1] A. M. Davis (2014) Meteorites and cosmochemical processes, 1. [2] Nevill N. et al. (2023) LPSC, 54, #1707. [3] Nevill N. et al. (2023) LPSC, 54, #1714.

NanoSIMS↗
NASA NTRS1985

Automatically-Programed Machine Tools

Software produces cutter location files for numerically-controlled machine tools. APT, acronym for Automatically Programed Tools, is among most widely used software systems for computerized machine tools. APT developed for explicit purpose of providing effective software system for programing NC machine tools. APT system includes specification of APT programing language and language processor, which executes APT statements and generates NC machine-tool motions specified by APT statements.

Purves, L.↗