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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Evaluation of telerobotic systems using an instrumented task board

An instrumented task board was developed at NASA Marshall Space Flight Center (MSFC). An overview of the task board design, and current development status is presented. The task board was originally developed to evaluate operator performance using the Protoflight Manipulator Arm (PFMA) at MSFC. The task board evaluates tasks for Orbital Replacement Unit (ORU), fluid connect and transfers, electrical connect/disconnect, bolt running, and other basic tasks. The instrumented task board measures the 3-D forces and torques placed on the board, determines the robot arm's 3-D position relative to the task board using IR optics, and provides the information in real-time. The PFMA joint input signals can also be measured from a breakout box to evaluate the sensitivity or response of the arm operation to control commands. The data processing system provides the capability for post processing of time-history graphics and plots of the PFMA positions, the operator's actions, and the PFMA servo reactions in addition to real-time force/torque data presentation. The instrumented task board's most promising use is developing benchmarks for NASA centers for comparison and evaluation of telerobotic performance.

Carroll, John D.↗
NASA NTRS1994

Data-Acquisition System With Remotely Adjustable Amplifiers

Improved data-acquisition system has both centralized and decentralized characteristics developed. Provides infrastructure for automation and standardization of operation, maintenance, calibration, and adjustment of many transducers. Increases efficiency by reducing need for diminishing work force of highly trained technicians to perform routine tasks. Large industrial and academic laboratory facilities benefit from systems like this one.

Nurge, Mark A.↗
NASA NTRS2010

Orion Post Landing LiOH and Toxic Sensor Development

The Orion Crew Exploration Vehicle (CEV) lands in the water with most resources depleted. There is a need to provide CO2 control while the cabin remains sealed for two hours post landing and there is a need to verify the outside air is free of ammonia or propellants, which may be venting from the vehicle, prior to opening the cabin. Development of approaches to perform these tasks while minimizing weight, volume, and cost are being investigated. This paper will document the results of those investigations.

Lewis, John F.↗
NASA NTRS2010

Language Model Combination and Adaptation Using Weighted Finite State Transducers

In speech recognition systems language model (LMs) are often constructed by training and combining multiple n-gram models. They can be either used to represent different genres or tasks found in diverse text sources, or capture stochastic properties of different linguistic symbol sequences, for example, syllables and words. Unsupervised LM adaption may also be used to further improve robustness to varying styles or tasks. When using these techniques, extensive software changes are often required. In this paper an alternative and more general approach based on weighted finite state transducers (WFSTs) is investigated for LM combination and adaptation. As it is entirely based on well-defined WFST operations, minimum change to decoding tools is needed. A wide range of LM combination configurations can be flexibly supported. An efficient on-the-fly WFST decoding algorithm is also proposed. Significant error rate gains of 7.3% relative were obtained on a state-of-the-art broadcast audio recognition task using a history dependently adapted multi-level LM modelling both syllable and word sequences

Liu, X.↗
NASA NTRSDate not supplied

Evaluation of Aerobic Capacity in Relation to Simulated Lunar Surface Extravehicular Activities

INTRODUCTION Astronauts will need to be physically prepared to successfully execute strenuous Extravehicular Activities (EVA)on the Lunar surface. Compared to Apollo missions, Artemis missions will include EVAs of increased physical demand, frequency, and duration, thus requiring adequate fitness to successfully and safely complete mission objectives and potential contingency scenarios. Currently, aerobic fitness standards for partial gravity (g)surface EVAs are not well supported by high-fidelity EVA analog data. This investigation aims to characterize metabolic demands from Lunar analog EVA simulations in relation to the current NASA standards for celestial partial-g aerobic fitness(aerobic capacity (VO2pk) ≥36.5ml/kg/min). METHODS To evaluate current Lunar EVA aerobic fitness requirements, a pilot study was performed to characterize metabolic ratesduring6 hour simulated EVAs. The EVAs were performed in pressurized MKIII (n=2male) and xEMU (n=3 female) spacesuits offloaded to 1/6 g in the NASA Active Response Gravity Offload System. VO2pk was assessed via graded exercise testing on acycle ergometer and physical workload was quantified as percent ofVO2pk. RESULTS Four out of five subjects did not meet the current NASA celestial surface EVA aerobic standard (3 xEMU, 1MKIII;35.1±0.9 ml/kg/min). During simulated EVAs, subjects (xEMU: 35±1ml/kg/min; MKIII: 44±10ml/kg/min) worked at an average 36%VO2pk(xEMU) and 31% VO2pk(MKIII). For xEMU subjects, the tasks with the greatest average metabolic rates were 2km treadmill traverse(0% grade: 47.2%VO2pk[max 69.1%]), object relocation (45.2%VO2pk[max 60.5%]), and 1.5km traverse (0% grade: 45%VO2pk[max 59.7%]). For MKIII subjects, the tasks with the greatest average metabolic rates were 0.5km treadmill traverse (30% grade: 35.4% VO2pk[max 45.5%]), object relocation(31% VO2pk[max 40.8%]), and treadmill traverse (0% grade: 29.9%VO2pk[max 45.9%]). CONCLUSIONS While average metabolic rates for simulated Lunar EVA fall within sustainable work ranges of30–40% VO2pkand life support system limitations, task-specific metabolic rates exceed this range and may indicate that greater fitness is necessary for more strenuous tasks expected to be performed on the Lunar surface. As few subjects met the standard, more data is needed to adequately evaluate the NASA 3001 standard.

N C Strock↗
NASA NTRS1977

Infrared Imagery of Shuttle (IRIS). Task 1

Assessment of available IR sensor technology showed that the four aerothermodynamic conditions of interest during the entry trajectory of space shuttle can be accommodated by an aircraft flying parallel to the orbiter reentry ground track. Thermal information from the sides of the vehicle can be obtained with degraded performance (temperatures below 800 K) by flying the C-141 aircraft on the opposite side of the shuttle ground track and in the direction opposite that which is optimum for lower surface viewing. An acquisition system using a 6.25-cm aperture telescope and a single indium antimonide detector were designed to meet the acquisition requirements and interface with the 91.5-cm telescope with minimum modification. An image plane system using 600 indium antimonide detectors in two arrays which requires no modification to the existing telescope was also designed. Currently available components were used in a data handling system with interfaces with the experimentors station and the HP2100 computer.

Chocol, C. J.↗
DOE OSTI2016

WE-H-207B-03: MRI Guidance in the Radiation Therapy Clinic: Site-Specific Discussions

In recent years, steady progress has been made towards the implementation of MRI in external beam radiation therapy for processes ranging from treatment simulation to in-room guidance. Novel procedures relying mostly on MR data are currently implemented in the clinic. This session will cover topics such as (a) commissioning and quality control of the MR in-room imagers and simulators specific to RT, (b) treatment planning requirements, constraints and challenges when dealing with various MR data, (c) quantification of organ motion with an emphasis on treatment delivery guidance, and (d) MR-driven strategies for adaptive RT workflows. The content of the session was chosen to address both educational and practical key aspects of MR guidance. Learning Objectives: Good understanding of MR testing recommended for in-room MR imaging as well as image data validation for RT chain (e.g. image transfer, filtering for consistency, spatial accuracy, manipulation for task specific); Familiarity with MR-based planning procedures: motivation, core workflow requirements, current status, challenges; Overview of the current methods for the quantification of organ motion; Discussion on approaches for adaptive treatment planning and delivery. T. Stanescu - License agreement with Modus Medical Devices to develop a phantom for the quantification of MR image system-related distortions.; T. Stanescu, N/A.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Synthesis of Anhydrous Acetates for the Components of Nuclear Fuel Recycling in Dialkylimidazolium Acetate Ionic Liquids [plus supplemental information]

A series of anhydrous acetate salts with uranium {[C 2 C 1 im][UO 2 (OAc) 3 ] (1), [C 2 C 2 im][UO 2 (OAc) 3 ] (2), and [C 4 C 1 im][UO 2 (OAc) 3 ] (3)}, lanthanides {[C 2 C 2 im] 2 [La(OAc) 5 ] (4) and [C 2 C 1 im] 2 [Nd(OAc) 5 ] (5)}, and strontium {[C 2 C 1 im] n [Sr- (OAc) 3 ] n (6)} (where C 2 C 1 im = 1-ethyl-3-methylimidazolium, C 2 C 2 im = 1,3-diethylimidazolium, C 4 C 1 im = 1-butyl-3-methylimi-dazolium, and OAc = acetate) have been prepared and structurally characterized. Both lanthanides and strontium are common components of the nuclear fuel waste, and their separation from uranium is an important but still challenging task. A new synthetic method with dialkylimidazolium acetate ionic liquids (ILs) as the solvent has been developed for the direct synthesis of homoleptic acetates from the corresponding hydrates and, unexpectedly, hardly soluble f-element oxides. Although the group of characterized compounds shows perfect structural variability, all actinide and lanthanide metal ions form monomeric complex anions where the metal cation coordinates to five ligands including two oxygen atoms in the case of uranium, as is commonly observed for uranyl compounds. Crystallographic analyses revealed that the complex [UO 2 (OAc) 3 ] - anions possess rather standard D 3h symmetry featuring a hexagonal-bipyramidal coordination environment, while the lanthanide anions [Ln(OAc) 5 ] 2- are fully asymmetric and the Ln 3+ cations are 10-coordinated in the form of a distorted bicapped tetragonal antiprism. This is the first report of lanthanide ions coordinated in this fashion. For Sr 2+ , 9-fold coordination through oxygen atoms in the form of a strongly distorted tricapped trigonal prism is observed. Furthermore, the crystallization of anhydrous, homoleptic, anionic acetate complexes from such a large variety of different metal salts appears to be due to the properties of dialkylimidazolium acetate ILs themselves, including enhanced basicity from the high concentration of free anions and their greater affinity for hydrogen-bonding solutes relative to metal cations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Epitaxial stabilization of Sr 3 Ir 2 O 7 thin films

Ruddlesden-Popper type Sr n+1 Ir n O 3n+1 compounds are a major focus of condensed matter physics, where the subtle balance between electron-electron correlation, spin–orbit interaction, and crystal field effect brings a host of emergent phenomena. While it is understandable that a canted antiferromagnetic insulating state with an easy-plane anisotropy is developed in Sr 2 IrO 4 as the two-dimensional limit of the series, it is intriguing that bilayer Sr 3 Ir 2 O 7 , with slightly higher effective dimensionality, stabilizes c-axis collinear antiferromagnetism. This also renders Sr 3 Ir 2 O 7 a unique playground to study exotic physics near a critical spin transition point. However, the epitaxial growth of Sr 3 Ir 2 O 7 is still a challenging task because of the narrow growth window. In our research, we have studied the thermodynamic process during the synthesis of Sr 3 Ir 2 O 7 thin films. We expanded the synthesis window by mapping out the relationship between the thin film crystal structure and the gas pressure. Furthermore, our work thus provides a more accessible avenue to stabilize metastable materials.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

CLOMP v1.5

CLOMP is the C version of the Livermore OpenMP benchmark developed to measure OpenMP overheads and other performance impacts due to threading. For simplicity, it does not use MPI by default but it is expected to be run on the resources a threaded MPI task would use (e.g., a portion of a shared memory compute node). Compiling with -DWITH_MPI allows packing one or more nodes with CLOMP tasks and having CLOMP report OpenMP performance for the slowest MPI task. On current systems, the strong scaling performance results for 4, 8, or 16 threads are of the most interest. Suggested weak scaling inputs are provided for evaluating future systems. Since MPI is often used to place at least one MPI task per coherence or NUMA domain, it is recommended to focus OpenMP runtime measurements on a subset of node hardware where it is most possible to have low OpenMP overheads (e.g., within one coherence domain or NUMA domain).

97 MATHEMATICS AND COMPUTING↗
NASA NTRS1993

NASA technology applications team: Applications of aerospace technology

This report covers the activities of the Research Triangle Institute (RTI) Technology Applications Team for the period 1 October 1992 through 30 September 1993. The work reported herein was supported by the National Aeronautics and Space Administration (NASA), Contract No. NASW-4367. Highlights of the RTI Applications Team activities over the past year are presented in Section 1.0. The Team's progress in fulfilling the requirements of the contract is summarized in Section 2.0. In addition to our market-driven approach to applications project development, RTI has placed increased effort on activities to commercialize technologies developed at NASA Centers. These Technology Commercialization efforts are summarized in Section 3.0. New problem statements prepared by the Team in the reporting period are presented in Section 4.0. The Team's transfer activities for ongoing projects with the NASA Centers are presented in Section 5.0. Section 6.0 summarizes the status of four add-on tasks. Travel for the reporting period is described in Section 7.0. The RTI Team staff and consultants and their project responsibilities are listed in Appendix A. Appendix B includes Technology Opportunity Announcements and Spinoff! Sheets prepared by the Team while Appendix C contains a series of technology transfer articles prepared by the Team.

Source record↗
NASA NTRS1994

Definition of ground test for verification of large space structure control

Under this contract, the Large Space Structure Ground Test Verification (LSSGTV) Facility at the George C. Marshall Space Flight Center (MSFC) was developed. Planning in coordination with NASA was finalized and implemented. The contract was modified and extended with several increments of funding to procure additional hardware and to continue support for the LSSGTV facility. Additional tasks were defined for the performance of studies in the dynamics, control and simulation of tethered satellites. When the LSSGTV facility development task was completed, support and enhancement activities were funded through a new competitive contract won by LCD. All work related to LSSGTV performed under NAS8-35835 has been completed and documented. No further discussion of these activities will appear in this report. This report summarizes the tether dynamics and control studies performed.

Glaese, John R.↗
NASA NTRS2003

Origin of Outer Solar System

We feel that at the present moment the available theoretical models of the Kuiper belt are still in advance of the data, and thus our main task has been to conduct observational work guided by theoretical motivations. Our efforts over the past year can be divided into four categories: A) Wide-field Searches for Kuiper Belt Objects; B) Pencil-beam Searches for Kuiper Belt Objects; C) Wide-field Searches for Moons of the Outer Planets; D) Pencil-beam Searches for Faint Uranian and Neptunian Moons; E) Recovery Observations. As of April 2002, we have conducted several searches for Kuiper belt objects using large-format mosaic CCD camera on 4-meter class telescopes. In May 1999, we used the Kitt Peak 4-meter with the NOAO Mosaic camera we attempted a search for KBOs at a range of ecliptic latitudes. In addition to our wide-field searches, we have conducted three 'pencil-beam' searches in the past year. In a pencil-beam search we take repeated integrations of the same field throughout a night. After preprocessing the resulting images we shift and recombine them along a range of rates and directions consistent with the motion of KBOs. Stationary objects then smear out, while objects moving at near the shift rate appear as point sources. In addition to our searches for Kuiper belt objects, we are completing the inventory of the outer solar system by search for faint satellites of the outer planets. In August 2001 we conducted pencil beam searches for faint Uranian and Neptunian satellites at CFHT and CTIO. These searches resulted in the discover of two Neptunian and four Uranian satellite candidates. The discovery of Kuiper belt objects and outer planet satellites is of little use if the discoveries are not followed by systematic, repeated astrometric observations that permit reliable estimates of their orbits.

Holman, Matthew J.↗
NASA NTRS2010

Effect of Target Location on Dynamic Visual Acuity During Passive Horizontal Rotation

The vestibulo-ocular reflex (VOR) generates eye rotation to compensate for potential retinal slip in the specific plane of head movement. Dynamic visual acuity (DVA) has been utilized as a functional measure of the VOR. The purpose of this study was to examine changes in accuracy and reaction time when performing a DVA task with targets offset from the plane of rotation, e.g. offset vertically during horizontal rotation. Visual acuity was measured in 12 healthy subjects as they moved a hand-held joystick to indicate the orientation of a computer-generated Landolt C "as quickly and accurately as possible." Acuity thresholds were established with optotypes presented centrally on a wall-mounted LCD screen at 1.3 m distance, first without motion (static condition) and then while oscillating at 0.8 Hz (DVA, peak velocity 60 deg/s). The effect of target location was then measured during horizontal rotation with the optotypes randomly presented in one of nine different locations on the screen (offset up to 10 deg). The optotype size (logMar 0, 0.2 or 0.4, corresponding to Snellen range 20/20 to 20/50) and presentation duration (150, 300 and 450 ms) were counter-balanced across five trials, each utilizing horizontal rotation at 0.8 Hz. Dynamic acuity was reduced relative to static acuity in 7 of 12 subjects by one step size. During the random target trials, both accuracy and reaction time improved proportional to optotype size. Accuracy and reaction time also improved between 150 ms and 300 ms presentation durations. The main finding was that both accuracy and reaction time varied as a function of target location, with greater performance decrements when acquiring vertical targets. We conclude that dynamic visual acuity varies with target location, with acuity optimized for targets in the plane of motion. Both reaction time and accuracy are functionally relevant DVA parameters of VOR function.

Appelbaum, Meghan↗
DOE OSTI2025

Passive Temperature Sensors for Nuclear Applications

In April 2007, the Department of Energy (DOE) designated the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF) to advance US leadership in nuclear science and technology. By attracting new users from universities, laboratories, and industry, this program supports basic and applied nuclear research to help address the nation's energy security needs. In support of this program, the Idaho National Laboratory (INL) established in-house capabilities to develop, fabricate, test, and qualify new and enhanced temperature sensors for irradiation testing. This effort is continuing today through the DOE?s Advanced Sensors and Instrumentation (ASI) program. Although most efforts emphasize sensors capable of providing real-time data, selected tasks have been completed to enhance passive sensors for irradiations where instrumentation leads cannot be included. These sensors include silicon carbide (SiC) monitors, melt wires and the sublime temperature monitor. SiC monitors are available to detect peak irradiation temperatures between 200°C and 800°C in reactor locations where instrumentation leads cannot be used. SiC monitors may be evaluated using specialized equipment installed at INL?s Measurement Sciences Laboratory (MSL). A melt wire inventory is also maintained at MSL. This inventory contains wires for specific use in irradiation experiments ranging in temperatures from 30°C to 1500°C. Melt wires and SiC monitors have had decades of research and application. Recent research has produced a passive monitor known as the sublime temperature monitor. This passive sensor has the capability of recording temperature gradients. This paper will discuss passive temperature sensors currently being researched and implemented under the ASI program.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

Discovering a Transferable Charge Assignment Model Using Machine Learning

Partial atomic charge assignment is of immense practical value to force field parametrization, molecular docking, and cheminformatics. Machine learning has emerged as a powerful tool for modeling chemistry at unprecedented computational speeds given accurate reference data. However, certain tasks, such as charge assignment, do not have a unique solution. We use a machine learning algorithm to discover a new charge assignment model by learning to replicate molecular dipole moments across a large, diverse set of nonequilibrium conformations of molecules containing C, H, N, and O atoms. The new model, called Affordable Charge Assignment (ACA), is computationally inexpensive and predicts dipoles of out-of-sample molecules accurately. Furthermore, dipole-inferred ACA charges are transferable to dipole and even quadrupole moments of much larger molecules than those used for training. We apply ACA to dynamical trajectories of biomolecules and produce their infrared spectra. Additionally, we find that ACA assigns similar charges to Charge Model 5 but with greatly reduced computational cost.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗