Search NASA⌕ Search

SEARCH · Search NASA

Results for “SIZE DETERMINATION”

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 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

MLSPICE: Machine Learning based SPICE Modeling Platform for Power Magnetics

Electrical power converters are critical to a wide range of applications ranging from renewable integration to transportation electrification, and can be a key factor determining the size, weight, and efficiency of energy conversion systems. Magnetic components are typically the largest and least efficient components in power electronics. While there have been major strides in the modeling and analysis of power semiconductor devices and circuit simulations, the necessary advances in the design of power magnetics have lagged. In this project, we have transformed the modeling and design of power magnetics with machine learning enabled methods and catalyze simultaneous disruptive improvements for ML-based power electronics design tools. A fully automated open-source machine learning based magnetics modeling platform – the MagNet project - with innovations in full stack have been developed to greatly accelerate the design process and provide new insights to magnetic material and geometry design. The ARPA-E funded MagNet platform contains three major building blocks: 1) a ML-Integrated Data Acquisition System (MIDAS): a highly automated data acquisition testbed which is capable of measuring a large number of magnetic cores with a wide range of electrical circuit excitations; 2) a ML-integrated Core Loss Model (MICLM): a machine-learning trained modeling method for modeling the core loss and saturation effects of magnetic materials for arbitrary excitation waveforms; 3) ML-guided Magnetics SPICE Simulation Tool (PMSPICE): a fully integrated CAD tool which can simulate the magnetics in SPICE. It can help the designers to quickly model the linear and non-linear characteristics of magnetic components and evaluate their behavior in SPICE simulations. The developed MagNet system has fully demonstrated the proposed performance target and has been open sourced to the entire power electronics community to advance the modeling and design of power magnetics from many different angles.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Mu2e Target Thermal Test Project

The Mu2e experiment requires a production target capable of operating under extreme thermal conditions caused by an 8 GeV proton beam. This project’s objective supports the development of the Mu2e Production Target by testing the Stickman model’s thermal behavior. To test this, Angel Flores Luviano has assisted Jonathan Williams in progressing this project by contributing to the development of a Radiative Cooling Test Fixture (RCTF) that will be used to evaluate the thermal behavior of the new production target model. Engineering calculations were performed to analyze thermal performance and pressure drop within the cold well and water cooling circuit, and determine optimal sizing for key components of the water system. An engineering note was made to document the calculations. CAD models of the water circuit piping, thermocouple mount, and radiator chimney were developed, and prototype test rig components were fabricated using 3D printing. Future work will focus on conti nued RCTF development which includes control system integration, heater hardware design, and interfaces that can be scaled up to increase thermal capacity.

Luviano, Angel Flores [Unlisted]↗
DOE OSTI2026

Stochastic tensor contraction for quantum chemistry

Many computational methods in ab initio quantum chemistry are formulated in terms of high-order tensor contractions, whose cost determines the size of system that can be studied. We introduce stochastic tensor contraction to perform such operations with greatly reduced cost, and present its application to the gold-standard quantum chemistry method, coupled cluster theory with up to perturbative triples. For total energy errors more stringent than chemical accuracy, we reduce the computational scaling to that of mean-field theory, while starting to approach the mean-field absolute cost, thereby challenging the existing cost-to-accuracy landscape. Benchmarks against state-of-the-art local correlation approximations further show that we achieve an order-of-magnitude improvement in both total computation time and error, with significantly reduced sensitivity to system dimensionality and electron delocalization. We conclude that stochastic tensor contraction is a powerful computational primitive to accelerate a wide range of quantum chemistry.

Chemical Physics (physics.chem-ph)↗
DOE OSTI2025

Raw Data for: Ultra-Confined Environments May Restrict the Possible Configurations of Supported Metal Complexes

Raw NMR data (1D 2H spectrum and pseudo-2D 2H CODEX spectra) in Bruker topspin format. Raw DRIFTS IR data as text files. Results from the DFT potential energy surface scans (coordinates are in the supporting information of the main publication). Raw BET nitrogen physisorption isotherms and the determined more size distributions.

Perras, Frederic A [Ames National Laboratory]↗
NASA NTRS1967

Impact cratering in granular materials.

Projectile impact cratering in granular materials, noting parameters determining crater size and volume and experimental agreement with hydrodynamic cratering theory

Cook, M. A.↗
NASA NTRS1972

Infrared diameter of IRC + 10216 determined from lunar occultations.

Lunar occultations of IRC + 10216 have been used to determine the size of the regions emitting 2.2-, 3.5-, 4.8-, and 10-micron radiation. The results are interpreted as the first direct measurement of the physical size of a dust shell surrounding a late-type star.

Toombs, R. I.↗
NASA NTRS1972

Atomization of liquid droplets in a convective gas stream.

New experimental results are reported for the atomization of liquid droplets by a high-speed air stream. A series of experiments are described in which water droplets, ranging in diameter from 1000 to 2700 microns, were introduced into the test section of a shock tube and allowed to interact with the convective flow established by the passage of a propagating shock front. A rotating drum camera system was employed to obtain a collection of streak photographs of the atomization process from which the breakup time, the breakup distance, and the ultimate atomized particle size were determined.

Ranger, A. A.↗
NASA NTRS1973

Meteoroid detector

A meteoroid detector is described which uses, a cold cathode discharge tube with a gas-pressurized cell in space for recording a meteoroid puncture of the cell and for determining the size of the puncture.

Mcmaster, L. R.↗
NASA NTRS1974

Economical technique for fragmentation testing

Automatic rifle was modified for remote, single-shot use. To simulate statistically--determined fragment size from rocket-motor casing blunt-nosed bullet was made of same alloy. Cartridge was loaded with enough powder to make bullet reach target at same estimated velocity as shrapnel from rocket casing.

Smith, T. H., III↗
NASA NTRS1975

Evaluation by step response tests of prototype relief valves designed for YF-12 inlet stability bleed system

Two stability bleed system relief valves were tested in a special dynamic test facility. These poppet valves are prototypes for a stability bleed system designed for use in a YF-12 flight inlet. One valve is unshielded, while the other has a special shield to eliminate the flow effect pressures on the piston. The tests determined the size of a damping orifice to be used during wind tunnel tests of the bleed system and verified an analog simulation of the valves. The effects of initial pressure level, pressure step size, and spring rate were investigated.

Dustin, M. O.↗
NASA NTRS1975

Structural optimization with flutter speed constraints using maximized step size

A procedure is presented for the minimization of structural mass while satisfying flutter speed constraints. The procedure differs from other optimization methods in that the flutter speed is exactly satisfied at each resizing step, and the step size is determined by a direct minimization of the objective function (mass) for each set of flutter derivatives calculated. In conjunction with this method, a new move vector is suggested which results in a very efficient resizing procedure.

Oconnell, R. F.↗
NASA NTRS1975

On Similarity Transformation and Geodetic Network Distortions Based on Doppler Satellite Observations

Models used in geodesy to transform two sets of coordinates are studied and distortions in geodetic networks are investigated. Commonly used transformation models are first reviewed and most of them are interpreted. Differences between various models are discussed. Pitfalls in partial solutions are then considered. It is shown that only as many chords and/or directional elements can be used in the computation as are needed to completely determine the size or shape of the polyhedron implied in the set of Cartesian coordinates. Each additional element causes the normal matrix to be singular provided that all correlations between the chords are used. A number of tables and maps indicating distortions in the NAD 27, Precise Traverse M-R '72, AUS, and SAD 69 geodetic datums are also included. The residuals of the coordinates are scanned for systematic patterns after transforming each geodetic system to the NWL9D Doppler system. Also, an attempt is made to show scale distortions in the NAD 27.

Leick, Alfred↗
NASA NTRS1976

The requirements for batteries for electric vehicles

The paper reassesses the role of electric vehicles in the modern transportation system and their potential impact on oil consumption. Three major factors determining the size of this impact are discussed: the market potential, the date of introduction, and the rate of consumer acceptance. The strategy of selecting the battery type for an urban car to introduce in coming years is analyzed. The results of the analysis suggest that the research and development emphasis should be placed on near- and mid-term battery technology. From the standpoint of maximizing both the cumulative impact and the benefits derived in the year 2000, however, a strategy of early introduction of near-term and mid-term cars followed by the far-term vehicles seems to produce the optimum result.

Schwartz, H. J.↗
NASA NTRS1976

Advanced Earth Observation System Instrumentation Study (AEOSIS)

The feasibility, practicality, and cost are investigated for establishing a national system or grid of artificial landmarks suitable for automated (near real time) recognition in the multispectral scanner imagery data from an earth observation satellite (EOS). The intended use of such landmarks, for orbit determination and improved mapping accuracy is reviewed. The desirability of using xenon searchlight landmarks for this purpose is explored theoretically and by means of experimental results obtained with LANDSAT 1 and LANDSAT 2. These results are used, in conjunction with the demonstrated efficiency of an automated detection scheme, to determine the size and cost of a xenon searchlight that would be suitable for an EOS Searchlight Landmark Station (SLS), and to facilitate the development of a conceptual design for an automated and environmentally protected EOS SLS.

Var, R. E.↗
NASA NTRS1977

Hybrid receiver study

The results are presented of a 4 month study to design a hybrid analog/digital receiver for outer planet mission probe communication links. The scope of this study includes functional design of the receiver; comparisons between analog and digital processing; hardware tradeoffs for key components including frequency generators, A/D converters, and digital processors; development and simulation of the processing algorithms for acquisition, tracking, and demodulation; and detailed design of the receiver in order to determine its size, weight, power, reliability, and radiation hardness. In addition, an evaluation was made of the receiver's capabilities to perform accurate measurement of signal strength and frequency for radio science missions.

Stone, M. S.↗