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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 OSTI2026

ndi

The Nuclear Data Interface (NDI) is an application programming interface (API) that allows access to standard nuclear data parameters while hiding the underlying details of the data libraries and their storage. It allows access to multigroup transport data (neutron and gamma), thermonuclear burn data, dosimetry data, production/depletion chain data, radiochemistry data, and secondary neutron multiplicity data. The name NDI refers to both the code and data formats supported by the code.

Saller, Thomas↗
NASA NTRS2011

Performance Comparison of Wireless Sensor Network Standard Protocols in an Aerospace Environment: ISA100.11a and ZigBee Pro

Standards-based wireless sensor network (WSN) protocols are promising candidates for spacecraft avionics systems, offering unprecedented instrumentation flexibility and expandability. Ensuring reliable data transport is key, however, when migrating from wired to wireless data gathering systems. In this paper, we conduct a rigorous laboratory analysis of the relative performances of the ZigBee Pro and ISA100.11a protocols in a representative crewed aerospace environment. Since both operate in the 2.4 GHz radio frequency (RF) band shared by systems such as Wi-Fi, they are subject at times to potentially debilitating RF interference. We compare goodput (application-level throughput) achievable by both under varying levels of 802.11g Wi-Fi traffic. We conclude that while the simpler, more inexpensive ZigBee Pro protocol performs well under moderate levels of interference, the more complex and costly ISA100.11a protocol is needed to ensure reliable data delivery under heavier interference. This paper represents the first published, rigorous analysis of WSN protocols in an aerospace environment that we are aware of and the first published head-to-head comparison of ZigBee Pro and ISA100.11a.

Wagner, Raymond S.↗
NASA NTRS1994

Earth Observing System (EOS) Communication (Ecom) Modeling, Analysis, and Testbed (EMAT) activiy

This paper describes the Earth Observing System (EOS) Communication (Ecom) Modeling, Analysis, and Testbed (EMAT) activity performed by Code 540 in support of the Ecom project. Ecom is the ground-to-ground data transport system for operational EOS traffic. The National Aeronautic and Space Administration (NASA) Communications (Nascom) Division, Code 540, is responsible for implementing Ecom. Ecom interfaces with various systems to transport EOS forward link commands, return link telemetry, and science payload data. To understand the complexities surrounding the design and implementation of Ecom, it is necessary that sufficient testbedding, modeling, and analysis be conducted prior to the design phase. These activities, when grouped, are referred to as the EMAT activity. This paper describes work accomplished to date in each of the three major EMAT activities: modeling, analysis, and testbedding.

Desai, Vishal↗
NASA NTRS2001

Effective Potential Energies and Transport Cross Sections for Atom-Molecule Interactions of Nitrogen and Nitrogen

The potential energy surfaces for H2-N and N2-N interactions are calculated by accurate ab initio methods and applied to determine transport data. The results confirm that an effective potential energy for accurately determining transport properties can be calculated using a single orientation. A simple method is developed to determine the dispersion coefficients of effective potential energies Effective potential energies required for O2-O collisions are determ=ined. The H2-N, N2-N, O2-H, and O2-O collision integrals are calculated and tabulated for a large range of temperatures. The theoretical values of the N2-N and O2-O diffusion coefficients compare well with measured data available at room temperature.

Stallcop, James R.↗
DOE OSTI2021

Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 1

This document presents a summary and framework of available transport data and other information directly relevant to the development of the groundwater transport model for Central and Western Pahute Mesa (PM) corrective action units (CAU). This model is referred to as the “PM CAU transport model” in this document. Central and Western PM are two areas of the Nevada National Security Site (NNSS) that historically were used for underground nuclear testing. These nuclear tests resulted in groundwater contamination in the vicinity of the underground test areas. As a result, the U.S. Department of Energy (DOE), Environmental Management (EM) Nevada Program is currently conducting a corrective action investigation (CAI) of the PM underground test areas. This work is a part of the Underground Test Area (UGTA) Activity in accordance with the Federal Facility Agreement and Consent Order (FFACO) (1996, as amended).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1995

Computing Properties Of Chemical Mixtures At Equilibrium

Scientists and engineers need data on chemical equilibrium compositions to calculate theoretical thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93 is general program that calculates chemical equilibrium compositions and properties of mixtures for any chemical system for which thermodynamic data are available. Includes thermodynamic data for more than 1,300 gaseous and condensed species and thermal-transport data for 151 gases. Written in FORTRAN 77.

Mcbride, B. J.↗
NASA NTRS1974

A comparison of the cesium and hydrogen hyperfine frequencies by means of Loran-C and portable clocks

A comparison of the hydrogen and cesium hyperfine frequencies is made using a hydrogen maser calibrated directly against the Flexible Bulb Large Storage Box Hydrogen Maser and a Hewlett-Packard portable high performance cesium clock calibrated indirectly against the USNO Master Clock via a Loran-C link. The portable cesium clock is transported from the USNO to Harvard University in operating condition. This allows the evaluation of the portable clock's performance under transport. Data are presented on the epoch and frequency stability of the portable clock under transport as well as the usefulness of a closure measurement in determining clock drift.

Reinhardt, V. S.↗
NASA NTRS1976

Comparison of a linear and a nonlinear washout for motion simulators utilizing objective and subjective data from CTOL transport landing approaches

Objective and subjective data gathered in the processes of comparing a linear and a nonlinear washout for motion simulators reveal that there is no difference in the pilot performance measurements used during instrument landing system (ILS) approaches with a Boeing 737 conventional takeoff and landing (CTOL) airplane between fixed base, linear washout, and nonlinear washout operations. However, the subjective opinions of the pilots reveal an important advance in motion cue presentation. The advance is not in the increased cue available over a linear filter for the same amount of motion base travel but rather in the elimination of false rotational rate cues presented by linear filters.

Parrish, R. V.↗
NASA NTRS1992

Candidate Mission from Planet Earth control and data delivery system architecture

Using a structured, experienced-based approach, Goddard Space Flight Center (GSFC) has assessed the generic functional requirements for a lunar mission control and data delivery (CDD) system. This analysis was based on lunar mission requirements outlined in GSFC-developed user traffic models. The CDD system will facilitate data transportation among user elements, element operations, and user teams by providing functions such as data management, fault isolation, fault correction, and link acquisition. The CDD system for the lunar missions must not only satisfy lunar requirements but also facilitate and provide early development of data system technologies for Mars. Reuse and evolution of existing data systems can help to maximize system reliability and minimize cost. This paper presents a set of existing and currently planned NASA data systems that provide the basic functionality. Reuse of such systems can have an impact on mission design and significantly reduce CDD and other system development costs.

Shapiro, Phillip↗
NASA NTRS1990

High performance VLSI telemetry data systems

NASA's deployment of major space complexes such as Space Station Freedom (SSF) and the Earth Observing System (EOS) will demand increased functionality and performance from ground based telemetry acquisition systems well above current system capabilities. Adaptation of space telemetry data transport and processing standards such as those specified by the Consultative Committee for Space Data Systems (CCSDS) standards and those required for commercial ground distribution of telemetry data, will drive these functional and performance requirements. In addition, budget limitations will force the requirement for higher modularity, flexibility, and interchangeability at lower cost in new ground telemetry data system elements. At NASA's Goddard Space Flight Center (GSFC), the design and development of generic ground telemetry data system elements, over the last five years, has resulted in significant solutions to these problems. This solution, referred to as the functional components approach includes both hardware and software components ready for end user application. The hardware functional components consist of modern data flow architectures utilizing Application Specific Integrated Circuits (ASIC's) developed specifically to support NASA's telemetry data systems needs and designed to meet a range of data rate requirements up to 300 Mbps. Real-time operating system software components support both embedded local software intelligence, and overall system control, status, processing, and interface requirements. These components, hardware and software, form the superstructure upon which project specific elements are added to complete a telemetry ground data system installation. This paper describes the functional components approach, some specific component examples, and a project example of the evolution from VLSI component, to basic board level functional component, to integrated telemetry data system.

Chesney, J.↗
NASA NTRS1986

Data reduction, management, and analysis software for CID

In an overview of the Data Reduction System, three major steps are examined. First, the raw data tapes were selected from the onboard recorders. These tapes should provide the best quality data for the data reduction software system. These tapes contained 352 channels of data, plus the monitor channels recorded in 8 bit Pulsed Coded Modulation (PCM) words. The next step consists of transcribing the PCM tapes from 8 bit serial digital data to 8 bit parallel digital data. This puts the data in the correct format for processing. The transcription process was accomplished here at LaRC in the Central Data Transportation Facility (CDTF). The last step in this 3 step process is to process the data through the reduction system developed for the Impact Dynamic Research Facility in the early part of 1980. Processing system criteria, system interface routines, and engineering units program that reads digitized data from tapes, and file management programs are discussed.

Davis, C. W.↗
NASA NTRS2009

Developing a Standard Method for Link-Layer Security of CCSDS Space Communications

Communications security for space systems has been a specialized field generally far removed from considerations of mission interoperability and cross-support in fact, these considerations often have been viewed as intrinsically opposed to security objectives. The space communications protocols defined by the Consultative Committee for Space Data Systems (CCSDS) have a twenty-five year history of successful use in over 400 missions. While the CCSDS Telemetry, Telecommand, and Advancing Orbiting Systems protocols for use at OSI Layer 2 are operationally mature, there has been no direct support within these protocols for communications security techniques. Link-layer communications security has been successfully implemented in the past using mission-unique methods, but never before with an objective of facilitating cross-support and interoperability. This paper discusses the design of a standard method for cryptographic authentication, encryption, and replay protection at the data link layer that can be integrated into existing CCSDS protocols without disruption to legacy communications services. Integrating cryptographic operations into existing data structures and processing sequences requires a careful assessment of the potential impediments within spacecraft, ground stations, and operations centers. The objective of this work is to provide a sound method for cryptographic encapsulation of frame data that also facilitates Layer 2 virtual channel switching, such that a mission may procure data transport services as needed without involving third parties in the cryptographic processing, or split independent data streams for separate cryptographic processing.

Biggerstaff, Craig↗
DOE OSTI2021

X-composer: enabling cross-environments in-situ workflows between HPC and cloud

As large-scale scientific simulations and big data analyses become more popular, it is increasingly more expensive to store huge amounts of raw simulation results to perform post-analysis. To minimize the expensive data I/O, "in-situ" analysis is a promising approach, where data analysis applications analyze the simulation generated data on the fly without storing it first. However, it is challenging to organize, transform, and transport data at scales between two semantically different ecosystems due to the distinct software and hardware difference. To tackle these challenges, we design and implement the X-Composer framework. X-Composer connects cross-ecosystem applications to form an "in-situ" scientific workflow, and provides a unified approach and recipe for supporting such hybrid in-situ workflows on distributed heterogeneous resources. X-Composer reorganizes simulation data as continuous data streams and feeds them seamlessly into the Cloud-based stream processing services to minimize I/O overheads. For evaluation, we use X-Composer to set up and execute a cross-ecosystem workflow, which consists of a parallel Computational Fluid Dynamics simulation running on HPC, and a distributed Dynamic Mode Decomposition analysis application running on Cloud. Our experimental results show that X-Composer can seamlessly couple HPC and Big Data jobs in their own native environments, achieve good scalability, and provide high-fidelity analytics for ongoing simulations in real-time.

Wang, Dali↗
NASA NTRS1975

Space Transportation System Payloads Data and Analysis

The background, current developments and future plans for the Space Transportation System Payloads Data and Analysis (SPDA) activities at Marshall Space Flight Center are reviewed. It is shown how the payload data bank and future planned activities will interface with the payloads community and Space Transportation System designers. The interfaces with the STS data base include NASA planning, international planning, payload design, shuttle design, user agencies planning and information, and OMB, Congress and others.

Peterson, J. D.↗
DOE OSTI2025

Hund’s flat band in a frustrated spinel oxide

Electronic flat bands associated with quenched kinetic energy and heavy electron mass have attracted great interest for promoting strong electronic correlations and emergent phenomena such as high-temperature charge fractionalization and superconductivity. Intense experimental and theoretical research has been devoted to establishing the rich nontrivial metallic and heavy fermion phases intertwined with such localized electronic states. Here, in this study, we investigate the transition metal oxide spinel LiV 2 O 4 , an enigmatic heavy fermion compound lacking localized f orbital states. We use angle-resolved photoemission spectroscopy and dynamical mean-field theory to reveal a kind of correlation-induced flat band with suppressed interatomic electron hopping arising from intra-atomic Hund’s coupling. The appearance of heavy quasiparticles is ascribed to a proximate orbital-selective Mott state characterized by fluctuating local moments as evidenced by complementary magnetotransport measurements. The spectroscopic fingerprints of long-lived quasiparticles and their disappearance with increasing temperature further support the emergence of a high-temperature “bad” metal state observed in transport data. This work resolves a long-standing puzzle on the origin of heavy fermion behavior and unconventional transport in LiV 2 O 4 . Simultaneously, it opens a path to achieving flat bands through electronic interactions in d-orbital systems with geometrical frustration, potentially enabling the realization of exotic phases of matter such as the fractionalized Fermi liquids.

36 MATERIALS SCIENCE↗
NASA NTRS1977

Tripropellant engine study

Work conducted was devoted to three main tasks. Thermochemical equilibrium performance data were assembled to establish the expected performance calculations of the mode 1 engine propellant combinations and thermodynamic and transport data for the products of combustion. Turbine drive gas characteristics were also established. Thrust chamber and nozzle cooling studies were devoted to the evaluation of H2, C3H8, CH4, and RP-1 as coolants in the existing SSME cooling circuit geometry. It was found that all these candidate coolants are feasible without limiting the desired operating conditions with the exception of RP-1, which would limit the maximum P(c) to 2000 psia. RP-1 could be used, however, to cool the nozzle only without imposing the chamber pressure limit. A total of 15 candidate engine system cycles were selected and a preliminary engine system balance was conducted for 12 of these systems to establish component operating flowrates, pressures and temperatures. It was found that the staged combustion cycles employing fuel rich LOX/hydrocarbon turbine drive gases are power limited.

Wheeler, D. B.↗
NASA NTRS1987

Data storage systems technology for the Space Station era

The paper presents the results of an internal NASA study to determine if economically feasible data storage solutions are likely to be available to support the ground data transport segment of the Space Station mission. An internal NASA effort to prototype a portion of the required ground data processing system is outlined. It is concluded that the requirements for all ground data storage functions can be met with commercial disk and tape drives assuming conservative technology improvements and that, to meet Space Station data rates with commercial technology, the data will have to be distributed over multiple devices operating in parallel and in a sustained maximum throughput mode.

Dalton, John↗
NASA NTRS1983

Thermal conductivity behavior of boron carbides

Knowledge of the thermal conductivity of boron carbides is necessary to evaluate its potential for high temperature thermoelectric energy conversion applications. The thermal diffusivity of hot pressed boron carbide B/sub 1-x/C/sub x/ samples as a function of composition, temperature and temperature cycling was measured. These data in concert with density and specific heat data yield the thermal conductivities of these materials. The results in terms of a structural model to explain the electrical transport data and novel mechanisms for thermal conduction are discussed.

Wood, C.↗