Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “analytical techniques”

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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Advanced algorithm for orbit computation

Computational and analytical techniques which simplify the solution of complex problems in orbit mechanics, Astrodynamics and Celestial Mechanics were developed. The major tool of the simplification is the substitution of transformations in place of numerical or analytical integrations. In this way the rather complicated equations of orbit mechanics might sometimes be reduced to linear equations representing harmonic oscillators with constant coefficients.

Szenbehely, V.↗
DOE OSTI2020

Report on Progress of correlation of in-situ and ex-situ data and the use of artificial intelligence to predict defects

The Transformational Challenge Reactor (TCR) program is leveraging additive manufacturing (AM) technologies to fabricate nuclear components which will be assembled into a fully functional microreactor core. Compared with traditional manufacturing technologies, AM technologies allow (1) real-time observation of the manufacturing process at a much higher resolution using in-situ monitoring technologies to capture the sensor signatures that scientifically describe each event occurring over time and space and (2) validation of the manufacturing process quality using domain-informed data analytics techniques as a potential qualification and certification methodology for the final component. This report provides an update on the program work on in-situ and ex-situ data correlation and associated data analytics results. Examples are provided to illustrate progress with respect to laser powder bed fusion (L-PBF), binder jetting, computed tomography (CT) reconstruction, and mechanical testing. Elements of the Digital Thread and data management infrastructure are discussed in the main document, and an extensive supplemental appendix is provided detailing the Digital Platform, as well as its implementation and subcomponents. In conclusion, the path forward for the next fiscal year is also discussed.

42 ENGINEERING↗
NASA NTRS1975

Simulation of aircraft crash and its validation

NASA Langley Research Center is engaged in an extensive research and development task aimed at providing the general aviation industry with reliable crashworthy airframe design technology. This paper describes the full-scale crash tests of general aviation airplanes being conducted to generate data on simulated crashes and to study the nonlinear dynamic behavior of aircraft structures. Analytical techniques under development for predicting nonlinear behavior of general airframe structures under crash-loading conditions are also described. Data are presented from the full-scale crash tests as well as comparison of analytical predictions with experimental results on some simplified structures.

Hayduk, R. J.↗
NASA NTRS1994

Friction and Wear Properties of As-deposited and Carbon Ion-implanted Diamond Films

Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 ke V ion energy, resulting in a dose of 1.2310(exp 17) carbon ions/cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40 percent relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and were properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to 10(exp -8)mm(exp 3)/N-m) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4)mm(exp 3/N-m) in ultrahigh vacuum. The carbon ion implanation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, nondiamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine- and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7)mm(exp 3/N-m). Even in ultrahigh vacuum, the presence of the nondiamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6)mm(exp 3)/N-m. Thus, the carbon ion-implanted, fine-grain diamond films can be effectively used as wear-resistant, self-lubricating coatings not only in air and dry nitrogen, but also in ultrahigh vacuum. The wear mechanism of diamond films is that of small fragments chipping off the surface. The size of wear particles is related to the extent of wear rates.

Miyoshi, Kazuhisa↗
NASA NTRSDate not supplied

Carbothermal Reduction Demonstration (CaRD) Gas Analysis Subsystem Development

The Carbothermal Reduction Demonstration (CaRD) project is currently developing a subscale system to demonstrate the operation and performance of the carbothermal reduction process and quantify the production of molar equivalent oxygen (carbon monoxide (CO) and carbon dioxide (CO2)). Traditionally, gas chromatography (GC) systems are utilized to qualify gases due to their ability to separate the volatile compounds within the gas mixture, followed by quantification of the isolated component of interest. Despite these capabilities, GCs require consumables for their operational mobile phase and consequently are not often considered a flight-forward option. An alternative analytical technique known as mass spectrometry measures the presentence of gas phase molecules based on their mass-to-charge ratio. Residual gas analyzers (RGAs) which utilize mass spectrometry are not traditionally used to quantify analytes, but proper design and calibrations can result in a flight-forward analytical instrument capable of direct quantification of volatile gases of interest. Kennedy Space Center's role for the project is to design a gas analyzer system to detect and quantify the CO and CO2 gas produced during the carbothermal reaction utilizing a commercial version of the Mass Spectrometer Observing Lunar Operations (MSolo) instrument. MSolo is a modified commercial off-the-shelf mass spectrometer which consists of quadrupole mass filter and space rated electronics. MSolo is currently a TRL 6 technology and manifested on the PRIME-1 and VIPER missions. This paper describes leveraging MSolo based instrumentation to develop a gas analysis system for the work outlined in the 2023 International Conference on Environmental Systems (ICES) paper number 313. The design and testing of the brassboard phase of the project will be described along with the current work underway which will cover the design and preliminary test results of the prototype phase.

Ryan Patrick Gott↗
NASA NTRS1980

Accuracy of trace element determinations in alternate fuels

A review of the techniques used at Lewis Research Center (LeRC) in trace metals analysis is presented, including the results of Atomic Absorption Spectrometry and DC Arc Emission Spectrometry of blank levels and recovery experiments for several metals. The design of an Interlaboratory Study conducted by LeRC is presented. Several factors were investigated, including: laboratory, analytical technique, fuel type, concentration, and ashing additive. Conclusions drawn from the statistical analysis will help direct research efforts toward those areas most responsible for the poor interlaboratory analytical results.

Greenbauer-Seng, L. A.↗
DOE OSTI2026

High sensitivity measurement of femtogram-level 238 Pu by thermal ionization mass spectrometry with correction of background 238 U

Low-concentration plutonium isotopic measurements provide a valuable fingerprint to identify possible material origins in the context of environmental contamination monitoring, environmental tracing, nuclear safeguards, nuclear forensics, and treaty monitoring. Thermal ionization mass spectrometry (TIMS) has long been recognized as one of the most sensitive techniques for plutonium isotopic measurement, but has not generally been utilized for 238 Pu determination, especially at low concentrations, due to an isobaric interference from 238 U, prevalent as background. Here, this work demonstrates a new analytical technique for correction of background 238 U from the 238 Pu counts collected during a TIMS analysis. The technique takes advantage of the higher ionization temperature of U relative to Pu and uses a 235 U tracer added after plutonium purification chemistry for 238 U semi-quantitative determination. This technique has been successfully applied to the determination of 238 Pu concentration and the 238 Pu/ 239 Pu ratio in sample types including single-isotope standards, isotopic certified reference materials, matrix-containing environmental reference materials, and simulated nuclear detonation debris. The results have been directly compared on a sample-by-sample basis to alpha spectrometry results. The detection limit by this new technique is 0.23 fg 238 Pu, which was previously unachievable by mass spectrometry and is possible in around 1 h of analysis time post-chemistry compared to weeks of required counting time by alpha spectrometry (at the same atom amount). We also present original, high precision data for Pu isotope concentrations in IAEA-384, Fangataufa Sediment, including 242 Pu results for the first time. The new technique allows measurement of a key isotope, 238 Pu, that was previously not measured in small environmental or nuclear forensics collections.

238Pu↗
NASA NTRS1976

An analytical and experimental evaluation of the plano-cylindrical Fresnel lens solar concentrator

Plastic Fresnel lenses for solar concentration are attractive because of potential for low-cost mass production. An analytical and experimental evaluation of line-focusing Fresnel lenses with application potential in the 200 to 370 C range is reported. Analytical techniques were formulated to assess the solar transmission and imaging properties of a grooves-down lens. Experimentation was based primarily on a 56 cm-wide lens with f-number 1.0. A sun-tracking heliostat provided a non-moving solar source. Measured data indicated more spreading at the profile base than analytically predicted. The measured and computed transmittances were 85 and 87% respectively. Preliminary testing with a second lens (1.85 m) indicated that modified manufacturing techniques corrected the profile spreading problem.

Hastings, L. J.↗
NASA NTRS2024

Carbothermal Reduction Demonstration (CaRD) Gas Analysis Subsystem Development

The Carbothermal Reduction Demonstration (CaRD) project is currently developing a subscale system to demonstrate the operation and performance of the carbothermal reduction process and quantify the production of molar equivalent oxygen via carbon monoxide (CO) and carbon dioxide (CO2). Traditionally, gas chromatography (GC) systems are utilized to quantify gases due to their ability to separate volatile compounds within the gas mixture, followed by detection of the isolated component of interest. Despite their capabilities, GCs require carrier gas consumables for their operational mobile phase and consequently are not often considered a flight-forward option. An alternative analytical technique known as mass spectrometry measures the presence of gas phase molecules without the need of carrier gas. Residual gas analyzers (RGAs), which are smaller and rugged mass spectrometers, are not traditionally used to quantify analytes as they serve more as a monitoring tool. However, proper application and calibration can result in a flight-forward analytical instrument capable of direct quantification of volatile compounds of interest. Kennedy Space Center's role for the JSC led CaRD project is to design a gas analyzer system to detect and quantify the CO and CO2 gases produced during the carbothermal reaction utilizing a commercial version of the Mass Spectrometer observing lunar operations (MSolo) instrument. MSolo is a modified commercial off-the-shelf RGA, which consists of quadrupole mass filter and space rated electronics. MSolo is currently a TRL 6 technology and manifested on the PRIME-1 and VIPER missions. This paper describes leveraging MSolo based instrumentation to develop a gas analysis system for the work outlined in the 2023 International Conference on Environmental Systems (ICES) paper number 313.

Ryan P Gott↗
DOE OSTI2020

Spin response function technique in spin-transparent synchrotrons

Small perturbative fields in a synchrotron influence both the spin and orbital motion of a stored beam. Their effect on the beam polarization consists of two contributions, a direct kick and an effect of the ring lattice due to orbit perturbation. Spin response function is an analytic technique to account for both contributions. We develop such a technique for the spin-transparent synchrotrons where the design spin motion is degenerate. Several perspective applications are illustrated or discussed. In particular, we consider the questions of the influence of lattice imperfections on the spin dynamics and spin manipulation during an experiment. The presented results are of a direct relevance to NICA (JINR), RHIC (BNL), EIC (BNL) and other existing and future colliders when they arranged with polarization control in the spin-transparent mode.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Near-zero-field magnetoresistance measurements: A simple method to track atomic-scale defects involved in metal-oxide-semiconductor device reliability

We demonstrate the ability of a relatively new analytical technique, near-zero-field magnetoresistance (NZFMR), to track atomic-scale phenomena involved in the high-field stressing damage of fully processed Si metal-oxide-semiconductor field-effect transistors. We show that the technique is sensitive to both the Pb0 and Pb1 dangling bond centers and that the presence of both centers can be inferred through NZFMR via hyperfine interactions with the central 29Si atoms of the dangling bonds. The NZFMR results also provide evidence for the redistribution of mobile hydrogen atoms at the Si/SiO2 interface and also a potential change in the average dipolar coupling constant between electrons in neighboring defects. This work shows that NZFMR offers significant analytical power for studying technologically relevant semiconductor device reliability problems and has advantages in experimental simplicity over comparable techniques.

Moxim, Stephen J. (ORCID:0000000309659904)↗
NASA NTRS1989

Historical review of missile aerodynamic developments

The development of missiles from early history up to about 1970 is discussed. Early unpowered missiles beyond the rock include the spear, the bow and arrow, the gun and bullet, and the cannon and projectile. Combining gunpowder with projectiles resulted in the first powered missiles. In the early 1900's, the development of guided missiles was begun. Significant advances in missile technology were made by German scientists during World War II. The dispersion of these advances to other countries following the war resulted in accelerating the development of guided missiles. In the late 1940's and early 1950's there was a proliferation in the development of missile systems in many countries. These developments were based primarily on experimental work and on relatively crude analytical techniques. Discussed here are some of the missile systems that were developed up to about 1970; some of the problems encountered; the development of an experimental data base for use with missiles; and early efforts to develop analytical methods applicable to missiles.

Spearman, M. Leroy↗
NASA NTRS1994

Light stable isotope analysis of meteorites by ion microprobe

The main goal was to develop the necessary secondary ion mass spectrometer (SIMS) techniques to use a Cameca ims-4f ion microprobe to measure light stable isotope ratios (H, C, O and S) in situ and in non-conducting mineral phases. The intended application of these techniques was the analysis of meteorite samples, although the techniques that have been developed are equally applicable to the investigation of terrestrial samples. The first year established techniques for the analysis of O isotope ratios (delta O-18 and delta O-17) in conducting mineral phases and the measurement of S isotope ratios (delta S-34) in a variety of sulphide phases. In addition, a technique was developed to measure delta S-34 values in sulphates, which are insulators. Other research undertaken in the first year resulted in SIMS techniques for the measurement of wide variety of trace elements in carbonate minerals, with the aim of understanding the nature of alteration fluids in carbonaceous chondrites. In the second year we developed techniques for analyzing O isotope ratios in nonconducting mineral phases. These methods are potentially applicable to the measurement of other light stable isotopes such as H, C and S in insulators. Also, we have further explored the analytical techniques used for the analysis of S isotopes in sulphides by analyzing troilite in a number of L and H ordinary chondrites. This was done to see if there was any systematic differences with petrological type.

Mcsween, Harry Y., Jr.↗
NASA NTRS1996

Friction and Wear Properties of As-Deposited and Carbon Ion-Implanted Diamond Films

Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 keV ion energy, resulting in a dose of 1.2 x 10(exp 17) carbon ions per cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40% relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and wear properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to lO(exp -8) mm(exp 3) N(exp -1) m(exp -1)) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4) mm(exp 7) N(exp -1) m(exp -1)) in ultrahigh vacuum. The carbon ion implantation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, non-diamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7) mm(exp 3) N(exp -1) m(exp-1)). Even in ultrahigh vacuum, the presence of the non-diamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6) mm(exp 3) N(exp -1) m(exp -1). Thus, the carbon ion-implanted, fine-grain diamond films can be effectively used as wear-resistant, self-lubricating coatings not only in air and dry nitrogen, but also in ultrahigh vacuum.

Miyoshi, Kazuhisa↗
NASA NTRS1997

The NASA B-757 HIRF Test Series: Flight Test Results

In 1995, the NASA Langley Research Center conducted a series of aircraft tests aimed at characterizing the electromagnetic environment (EME) in and around a Boeing 757 airliner. Measurements were made of the electromagnetic energy coupled into the aircraft and the signals induced on select structures as the aircraft was flown past known RF transmitters. These measurements were conducted to provide data for the validation of computational techniques for the assessment of electromagnetic effects in commercial transport aircraft. This paper reports on the results of flight tests using RF radiators in the HF, VHF, and UHF ranges and on efforts to use computational and analytical techniques to predict RF field levels inside the airliner at these frequencies.

Moeller, Karl J.↗
NASA NTRS2012

The Importance of Meteorite Collections to Sample Return Missions: Past, Present, and Future Considerations

While much of the scientific community s current attention is drawn to sample return missions, it is the existing meteorite and cosmic dust collections that both provide the paradigms to be tested by these missions and the context for interpreting the results. Recent sample returns from the Stardust and Hayabusa missions provided us with new materials and insights about our Solar System history and processes. As an example, Stardust sampled CAIs among the population of cometary grains, requiring extensive and unexpected radial mixing in the early solar nebula. This finding would not have been possible, however, without extensive studies of meteoritic CAIs that established their high-temperature, inner Solar System formation. Samples returned by Stardust also revealed the first evidence of a cometary amino acid, a discovery that would not have been possible with current in situ flight instrument technology. The Hayabusa mission provided the final evidence linking ordinary chondrites and S asteroids, a hypothesis that developed from centuries of collection and laboratory and ground-based telescopic studies. In addition to these scientific findings, studies of existing meteorite collections have defined and refined the analytical techniques essential to studying returned samples. As an example, the fortuitous fall of the Allende CV3 and Murchison CM2 chondrites within months before the return of Apollo samples allowed testing of new state-of-the-art analytical facilities. The results of those studies not only prepared us to better study lunar materials, but unanticipated discoveries changed many of our concepts about the earliest history and processes of the solar nebula. This synergy between existing collections and future space exploration is certainly not limited to sample return missions. Laboratory studies confirmed the existence of meteorites from Mars and raised the provocative possibility of preservation of ancient microbial life. The laboratory studies in turn led to a new wave of Mars exploration that ultimately could lead to sample return focused on evidence for past or present life. This partnership between collections and missions will be increasingly important in the coming decades as we discover new questions to be addressed and identify targets for for both robotic and human exploration . Nowhere is this more true than in the ultimate search for the abiotic and biotic processes that produced life. Existing collections also provide the essential materials for developing and testing new analytical schemes to detect the rare markers of life and distinguish them from abiotic processes. Large collections of meteorites and the new types being identified within these collections, which come to us at a fraction of the cost of a sample return mission, will continue to shape the objectives of future missions and provide new ways of interpreting returned samples.

Welzenbach, L. C.↗
DOE OSTI2026

Forensic characterization of surrogate nuclear explosion debris: radiochemical and spectroscopic strategies for method validation

Surrogate nuclear explosion debris (SNED) has emerged as a critical platform for advancing post-detonation nuclear forensic analysis in the absence of readily accessible historic materials. SNED enables controlled investigation and validation of analytical methodologies used to interrogate the chemical, isotopic, radiological, and microstructural signatures preserved in nuclear explosion debris. This review presents an integrated assessment of destructive and non-destructive analytical techniques commonly employed within decision-driven nuclear forensic workflows. Each technique is discussed individually while highlighting how it contributes to different stages of post-detonation analysis. Core methods – including gamma and alpha spectrometry, ICP-MS, TIMS, SIMS, SEM-EDS, XRF, LIBS, vibrational spectroscopy, and X-ray absorption spectroscopy – are critically evaluated with respect to forensic maturity, information content, and matrix limitations. Emphasis is placed on the role of SNED in benchmarking multi-modal workflows and identifying gaps in reproducing heterogeneity, fractionation, and radiation-driven evolution relevant to forensic attribution.

X-ray spectroscopic methods↗
NASA NTRS1983

The response of vegetation to geochemical conditions

An understanding of the factors of vegetation response to changes in the geochemistry of the environment may give exploration geologists and other researchers an additional and effective tool for rock type discrimination. The factors of vegetation response can be grouped into three principal categories: structural or morphological factors, taxonomic factors which include indicator flora as well as vegetation assemblages, and spectral factors which represent the manner in which the vegetation interacts with electromagnetic radiation. The response of these factors over areas of anomalous mineralization is often unique and may be due to nutrient deficiencies and/or imbalances, toxicity and stress caused by anomalous mineral concentrations in the soil, low water retention, and plant competition. The successful use of geobotanical techniques results from the integration of the geobotanical observations with other techniques. The use of remote sensing in such a program must be predicated on those factors which can be discriminated within the constraints of the spatial, spectral, radiometric, and temporal resolutions of the sensing system and with appropriate analytical techniques.

Mouat, D. A.↗