Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Data staging”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,675 records · Page 93
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

SU-E-J-215: Onboard Split PET Including the Effects of Attenuation, Scatter, and Random Events

Purpose: Positron emission tomography (PET) using split PET geometry was investigated as an on-board system for functional imaging and PET marker tracking, specifically with tomotherapy. The open dual ring PET would allow measurement of both inter and intra-fractional variation, improving the delineation of tumor volume at any stage in the radiation treatment delivery process. We present results from data obtained using Monte Carlo simulations including the effects of attenuation, random events, and scatter. Methods: PET design was accomplished via Monte Carlo simulations with GATE, the Geant4 Application for Emission Tomography. Images were reconstructed using Software for Image Reconstruction (STIR) with a fully 3D ordered subset expectation maximization (OSEM) image reconstruction technique. Results: Monte Carlo simulations of the split PET geometry indicate that including physical factors that degrade image quality such as attenuation, random events, and scatter still prove the feasibility of near real-time PET for both inter and intra-fractional radiation delivery. The image quality of scan times under 1 minute reveals that it is possible to utilize PET scanning and reconstruction during the treatment session intrafractionally. GATE also simulates the depth information but does not correct obliqueness of the path of line of response so the data is much more realistic than the data obtained with ray tracing. Conclusion: Onboard split PET with TomoTherapy can generate quality images under 1 minute scan times without the need to correct for attenuation, scatter, random events, or depth information of the interaction.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Atomistic Simulation of the Fission-Fragment-Induced Formation of Defects in a Uranium–Molybdenum Alloy

The formation of defects in a uranium–molybdenum alloy induced by xenon and zirconium ion irradiation with energies typical of fission fragments has been simulated within the two-temperature atomistic model and Monte Carlo method. This has allowed estimating the total number of primary radiation defects formed at the “thermal spike” stage and in collision cascades for different temperatures. The calculated threshold stopping powers of ions responsible for the formation of defects at the thermal spike stage are in good agreement with the available theoretical and experimental data.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Measurements of the reactor neutron power in absolute units

The neutron power of the reactor of the Yenisei space nuclear power plant is measured in absolute units using the modernized method of correlation analysis during the ground-based tests of the Yenisei prototypes. Results of the experiments are given. The desired result is obtained in a series of experiments carried out at the stage of the plant preparation for tests. The acceptability of experimental data is confirmed by the results of measuring the reactor neutron power in absolute units at the nominal level by the thermal balance during the life cycle tests of the ground prototypes.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2015

Asymmetry of the Balmer-alpha line shape and recovery of the effective hydrogen temperature in the tokamak scrape-off layer

An algorithm for recovering the effective temperature of atoms of hydrogen (and its isotopes) in the tokamak scrape-off layer from the asymmetry of the Balmer-alpha line shape is proposed. The algorithm is based on the parametrization of the asymmetry of the line shape caused by the nonlocal character of neutral hydrogen flux from the wall into the tokamak plasma. The accuracy of the algorithm is tested against the results of simulations of the velocity distribution function of deuterium neutrals in the scrape-off layer by the EIRENE code with the use of the source data on the main plasma component in the quasi-stationary stage of the inductive mode of ITER operation calculated by the SOLPS4.3 (B2-EIRENE) code.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2018

Kinetics of Macrolocalization Patterns of Plastic Flow of Metals

The features of the macroscopic inhomogeneity of plastic deformation in the form of autowaves with a pulsating amplitude are analyzed, and data on the localization of sources of acoustic emission at different stages of plastic flow in the stretching of fcc mono- and polycrystals are presented. The relationship between the local components of the plastic distortion tensor in the strain localization zone is traced. The role of acoustic phenomena accompanying the localization of plastic strain in the development of the process of plastic deformation is considered.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Statistical Regularities of Formation of a Main Crack in a Structurally Inhomogeneous Material under Various Deformation Conditions

The peculiarities of the formation of a main crack in the Westerly granite samples under quasistatic uniaxial compression without any lateral upthrust have been studied using the data of acoustic emission (AE) and X-ray computer microtomography (CT). The multifractal analysis of pauses between acoustic emission events and the analysis of the energy distribution functional forms of the AE signal have been performed. According to the computer tomography data, defects form only near a future main crack; i.e., no stage of disperse accumulation of defects over entire sample volume has been revealed. Two stages of the main crack formation have been observed: the first stage is characterized by an exponential energy distribution of AE signals and the second stage is characterized by a power low of the AE signal energy distribution. The multifractal analysis of the pauses between neighboring AE signals demonstrate the transition from the multifractal dynamics of the acoustic emission to the monofractal dynamics when approaching a fracture moment.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Lessons from modENCODE

Consortium aimed to map functional elements—including transcripts, chromatin marks, regulatory factor binding sites, and origins of DNA replication—in the model organisms Drosophila melanogaster and Caenorhabditis elegans. During its five-year span, the consortium conducted more than 2,000 genome-wide assays in developmentally staged animals, dissected tissues, and homogeneous cell lines. Analysis of these data sets provided foundational insights into genome, epigenome, and transcriptome structure and the evolutionary turnover of regulatory pathways. These studies facilitated a comparative analysis with similar data types produced by the ENCODE Consortium for human cells. Genome organization differs drastically in these distant species, and yet quantitative relationships among chromatin state, transcription, and cotranscriptional RNA processing are deeply conserved. Of the many biological discoveries of the modENCODE Consortium, we highlight insights that emerged from integrative studies. We focus on operational and scientific lessons that may aid future projects of similar scale or aims in other, emerging model systems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Adamantine 1.0: A Thermomechanical Simulator for Additive Manufacturing

Adamantine is a thermomechanical simulation code that is written in C++ and built on top of deal.II (Arndt et al., 2023), p4est (Burstedde et al., 2011), ArborX (Lebrun-Grandié et al., 2020), Trilinos (The Trilinos Project Team, 2020), and Kokkos (Trott et al., 2022). Adamantine was developed with additive manufacturing in mind and it is particularly well adapted to simulate fused filament fabrication, directed energy deposition, and powder bed fusion. Adamantine employs the finite element method with adaptive mesh refinement to solve a nonlinear anisotropic heat equation, enabling support for various additive manufacturing processes. It can also perform elastoplastic and thermoelastoplastic simulations. It can handle materials in three distinct phases (solid, liquid, and powder) to accurately reflect the physical state during different stages of the manufacturing process. To enhance simulation accuracy, adamantine incorporates data assimilation techniques (Asch et al., 2016). This allows it to integrate experimental data from sensors like thermocouples and infrared (IR) cameras. This combined approach helps account for errors arising from input parameters, material properties, models, and numerical calculations, leading to more realistic simulations that reflect what occurs in a particular print.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Coupling the System Analysis Module with SAS4A/SASSYS-1

SAS4A/SASSYS-1 is a simulation tool used to perform deterministic analysis of anticipated events as well as design basis and beyond design basis accidents for advanced reactors, with an emphasis on sodium fast reactors. SAS4A/SASSYS-1 has been under development and in active use for nearly forty-five years, and is currently maintained by the U.S. Department of Energy under the Office of Advanced Reactor Technology. Although SAS4A/SASSYS-1 contains a very capable primary and intermediate system modeling component, PRIMAR-4, it also has some shortcomings: outdated data management and code structure makes extension of the PRIMAR-4 module somewhat difficult. The user input format for PRIMAR-4 also limits the number of volumes and segments that can be used to describe a given system. The System Analysis Module (SAM) is a fairly new code development effort being carried out under the U.S. DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM is being developed with advanced physical models, numerical methods, and software engineering practices; however, it is currently somewhat limited in the system components and phenomena that can be represented. For example, component models for electromagnetic pumps and multi-layer stratified volumes have not yet been developed. Nor is there support for a balance of plant model. Similarly, system-level phenomena such as control-rod driveline expansion and vessel elongation are not represented. This report documents fiscal year 2016 work that was carried out to couple the transient safety analysis capabilities of SAS4A/SASSYS-1 with the system modeling capabilities of SAM under the joint support of the ART and NEAMS programs. The coupling effort was successful and is demonstrated by evaluating an unprotected loss of flow transient for the Advanced Burner Test Reactor (ABTR) design. There are differences between the stand-alone SAS4A/SASSYS-1 simulations and the coupled SAS/SAM simulations, but these are mainly attributed to the limited maturity of the SAM development effort. The severe accident modeling capabilities in SAS4A/SASSYS-1 (sodium boiling, fuel melting and relocation) will continue to play a vital role for a long time. Therefore, the SAS4A/SASSYS-1 modernization effort should remain a high priority task under the ART program to ensure continued participation in domestic and international SFR safety collaborations and design optimizations. On the other hand, SAM provides an advanced system analysis tool, with improved numerical solution schemes, data management, code flexibility, and accuracy. SAM is still in early stages of development and will require continued support from NEAMS to fulfill its potential and to mature into a production tool for advanced reactor safety analysis. The effort to couple SAS4A/SASSYS-1 and SAM is the first step on the integration of these modeling capabilities.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

Secondary Emission Detector Modules for High Energy Physics Experiments

The objectives of this Phase I SBIR project and the corresponding work plan consisted of detector geometry simulations and functional studies of pre-prototypes for both venetian-blind type and MEMS type. Modifications and improvements to the vacuum test station and data acquisition were also made throughout the project. In the final stages of this Phase I, we were able to do initial testing of devices built and we provide in this report the results of these measurements and all corresponding conclusions.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2026

TASTI-GRID: a holistic view of Florida's grid resilience opportunities

In December of 2025, the American Society of Civil Engineers updated Florida’s infrastructure grade to a ”C+” – reflecting overall investments in recent years. With the recommendation to further strengthen the electric grid and establish consistent building standards, extreme weather, aging infrastructure, and population in-migration are still compounding Florida’s grid vulnerabilities. Key challenges related to hurricane and other tropical & marine weather events are not unique to Florida. However, the state’s topography, location, demographics, and variation among rural and urban centers for tourism and industry, demonstrate the need for unique approaches to advancing critical infrastructure resilience, particularly for large concentrations of elderly residents or in areas of historic underinvestment. Florida’s grid asset advancements are credited with a reduction in average power outage durations. Yet, improvements since 2021 have set the stage for future resilience activities – as modernization efforts have greatly improved data collection – enabling better understanding of vulnerabilities and trends across counties and localities (particularly in Central Florida).

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2026

SENTRA: A Modular Computational Graph Framework for Critical Mineral and Materials Supply Chains: Part I: Network Construction Latent-Quantity Estimation, and Temporal Graph Forecasting

Global supply chains for critical minerals and materials are complex, evolving networks of countries, products, production stages, and trade relationships. Existing analytical approaches are limited by fragmented data and static network representations that do not capture the dynamic production dependencies linking raw materials, intermediate products, and final goods across multiple countries. Trade and production statistics provide only a partial view of domestic production, inventories, and material flows, making it difficult to identify indirect sourcing pathways, hidden dependencies, and embedded foreign exposures. This paper introduces the Supply Chain Exposure Network Tracking and Risk Assessment (SENTRA) framework, a modular graph-based computational framework for constructing, analyzing, and forecasting dynamic supply chain networks. As the first paper in a three-part methodological series, it establishes the computational foundation of SENTRA by constructing a temporal attributed multi-relational graph whose nodes represent product–country pairs and whose edges encode observed trade and within-country value-chain relationships. Statistical estimation and constrained optimization recover latent production, final demand, and product input dependency coefficients while enforcing economic accounting constraints. Graph-derived exposure measures quantify direct, transshipment, value-chain, and multi-hop supply chain dependencies independently of the forecasting model. A temporal graph forecasting architecture based on a relational graph neural network then forecasts the evolution of the graph under mass-balance constraints with distribution-free conformal uncertainty quantification. Validation on the global aluminum supply chain shows that the learned graph representations recover economically meaningful supply chain structure, accurately forecast out-of-sample trade relationships, and produce well-calibrated prediction intervals. Subsequent papers apply this computational foundation to exposure assessment, disruption analysis, and scenario-based policy analysis, and extend the framework to multimaterial supply chain modeling and decision support.

36 MATERIALS SCIENCE↗
NASA NTRS1971

Aerodynamic characteristics of Lockheed delta-body orbiter and stage-and-one-half launch vehicle

An experimental wind tunnel test program was conducted to investigate the subsonic through high supersonic aerodynamic characteristics of the Lockheed delta lifting body orbiter and stage-and-one-half launch vehicle. Analyses and results of these data are presented. A 0.01-scale model of the LS 200-5 system was designed and fabricated for testing in wind tunnels. Orbiter and launch configurations were tested over a speed range of Mach 0.6 to 2.0, whereas only the orbiter was tested over a speed range of Mach 2.3 to 4.6. Six-component force and moment data, base pressures, and schlieren photos were obtained at various angles-of-attack and sideslip. A 0.03-scale model of the orbiter was also designed, fabricated, and tested in a wind tunnel. Six-component force and moment data, base pressure, and a limited amount of tuft flow visualization data were obtained on a variety of configuration combinations.

Velligan, F. A.↗
NASA NTRS1975

Crop identification technology assessment for remote sensing (CITARS). Volume 10: Interpretation of results

The CITARS was an experiment designed to quantitatively evaluate crop identification performance for corn and soybeans in various environments using a well-defined set of automatic data processing (ADP) techniques. Each technique was applied to data acquired to recognize and estimate proportions of corn and soybeans. The CITARS documentation summarizes, interprets, and discusses the crop identification performances obtained using (1) different ADP procedures; (2) a linear versus a quadratic classifier; (3) prior probability information derived from historic data; (4) local versus nonlocal recognition training statistics and the associated use of preprocessing; (5) multitemporal data; (6) classification bias and mixed pixels in proportion estimation; and (7) data with differnt site characteristics, including crop, soil, atmospheric effects, and stages of crop maturity.

Bizzell, R. M.↗
NASA NTRS1976

Comparisons of cloud cover evaluated from LANDSAT imagery and meteorological stations across the British Isles

The author has identified the following significant results. This stage of the study has confirmed the initial supposition that LANDSAT data could be analyzed to provide useful data on cloud amount, and that useful light would be thrown thereby on the performance of the ground observer of this aspect of the state of the sky. This study, in comparison with previous studies of a similar nature using data from meteorological satellites, has benefited greatly from the much higher resolution data provided by LANDSAT. This has permitted consideration of not only the overall performance of the surface observer in estimating total cloud cover, but also his performance under different sky conditions.

Barrett, E. C.↗
NASA NTRS1978

A Multi-Band Far-Infrared Survey with a Balloon-Borne Telescope

Nine additional radiation sources, above a 3-sigma confidence level of 1300 Jy, were identified at 100 microns by far infrared photometry of the galactic plane using a 0.4 meter aperture, liquid helium cooled, multichannel far infrared balloon-borne telescope. The instrument is described, including its electronics, pointing and suspension systems, and ground support equipment. Testing procedures and flight staging are discussed along with the reduction and analysis of the data acquired. The history of infrared astronomy is reviewed. General infrared techniques and the concerns of balloon astronomers are explored.

Jacobson, M. R.↗
NASA NTRS1979

Predicting dynamic performance limits for servosystems with saturating nonlinearities

A generalized treatment for a system with a single saturating nonlinearity is presented and compared with frequency response plots obtained from an analog model of the system. Once the amplitude dynamics are predicted with the limit lines, an iterative technique is employed to determine the system phase response. The saturation limit line technique is used in conjunction with velocity and acceleration limits to predict the performance of an electro-hydraulic servosystem containing a single-stage servovalve. Good agreement was obtained between predicted performance and experimental data.

Webb, J. A., Jr.↗