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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 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

OpenMSI Arrayed Analysis Tools v2.0

Mass spectrometry imaging (MSI) enables high-resolution spatial mapping of biomolecules in samples and is a valuable tool for the analysis of tissues from plants and animals, microbial interactions, high-throughput screening, drug metabolism, and a host of other applications. This is accomplished by desorbing molecules from the surface on spatially defined locations, using a laser or ion beam. These ions are analyzed by a mass spectrometry and collected into a MSI 'image', a dataset containing unique mass spectra from the sampled spatial locations. MSI is used in a diverse and increasing number of biological applications. The OpenMSI Arrayed Analysis Tool (OMAAT) is a new software method that addresses the challenges of analyzing spatially defined samples in large MSI datasets, by providing support for automatic sample position optimization and ion selection.

BOWEN, BENJAMIN↗
DOE OSTI2021

BETO 2021 Peer Review - Process Monitoring and Predictions of Biorefinery Performance

Online process monitoring coupled with rapid predictive tools will be essential to refineries of the future to provide real-time feedback and process control on new, renewable feeds and their accompanying processes and products. This project will provide refinery operators with tools to predict product component concentrations in minutes from online, slip stream mass spectra, allowing for rapid detection of off-specification product. We will arrive at a template for predictive tool generation through the development of a specific tool as a starting point -- co-processing of pyrolysis oils and vacuum gas oil over fluid catalytic cracking (FCC) catalysts.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

A global significance evaluation method using simulated events

In High-Energy Physics experiments it is often necessary to evaluate the global statistical significance of apparent resonances observed in invariant mass spectra. One approach to determining significance is to use simulated events to find the probability of a random fluctuation in the background mimicking a real signal. As a high school summer project, we demonstrate a method with Monte Carlo simulated events to evaluate the global significance of a potential resonance with some assumptions. This method for determining significance is general and can be applied, with appropriate modification, to other resonances.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

gcxgclab: Two Dimensional Gas Chromatography Preprocessing and Analysis

The goal of gcxgclab is to provide a comprehensive program for preprocessing and analysis of two dimensional gas chromatography data. It is equipped with functions for baseline correction, smoothing, peak identification, peak alignment, identification of EICs, Mass Spectra, targeted analysis, compound identification with NIST and non-targeted analysis, plus plotting and data visualization.

GAMBLE, STEPHANIE↗
DOE OSTI2016

Mass Ordering of Spectra from Fragmentation of Saturated Gluon States in High-Multiplicity Proton-Proton Collisions

The mass ordering of mean transverse momentum $\langle$p T $\rangle$ and of the Fourier harmonic coefficient v 2 (p T ) of azimuthally anisotropic particle distributions in high energy hadron collisions is often interpreted as evidence for the hydrodynamic flow of the matter produced. We investigate an alternative initial state interpretation of this pattern in high-multiplicity proton-proton collisions at the LHC. The QCD Yang-Mills equations describing the dynamics of saturated gluons are solved numerically with initial conditions obtained from the color-glass-condensate-based impact-parameter-dependent glasma model. The gluons are subsequently fragmented into various hadron species employing the well established Lund string fragmentation algorithm of the pythia event generator. Lastly, we find that this initial state approach reproduces characteristic features of bulk spectra, in particular, the particle mass dependence of $\langle$p T $\rangle$ and v 2 (p T ).

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Spectral archives: extending spectral libraries to analyze both identified and unidentified spectra.

Tandem mass spectrometry (MS/MS) experiments yield multiple, nearly identical spectra of the same peptide in various laboratories, but proteomics researchers typically do not leverage the unidentified spectra produced in other labs to decode spectra they generate. We propose a spectral archives approach that clusters MS/MS datasets, representing similar spectra by a single consensus spectrum. Spectral archives extend spectral libraries by analyzing both identified and unidentified spectra in the same way and maintaining information about peptide spectra that are common across species and conditions. Thus archives offer both traditional library spectrum similarity-based search capabilities along with new ways to analyze the data. By developing a clustering tool, MS-Cluster, we generated a spectral archive from ~1.18 billion spectra that greatly exceeds the size of existing spectral repositories. We advocate that publicly available data should be organized into spectral archives rather than be analyzed as disparate datasets, as is mostly the case today.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

A REVISED CALIBRATION OF THE VIRIAL MASS ESTIMATOR FOR BLACK HOLES IN ACTIVE GALAXIES BASED ON SINGLE-EPOCH Hβ SPECTRA

The masses of supermassive black holes (BHs) in broad-line active galactic nuclei (AGNs) can be measured through reverberation mapping, but this method currently cannot be applied to very large samples or to high-redshift AGNs. As a practical alternative, one can devise empirical scaling relations, based on the correlation between broad-line region size and AGN luminosity and the relation between BH mass and bulge stellar velocity dispersion, to estimate the virial masses of BHs from single-epoch spectroscopy. We present a revised calibration of the BH mass estimator for the commonly used Hβ emission line. Our new calibration takes into account the recent determination of the virial coefficient for pseudo and classical bulges.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2010

Dilepton radiation by vector mesons and off-shell partons in the hot and dense medium

According to the dynamical quasiparticle model (DQPM) - matched to reproduce lattice QCD results in thermodynamic limit, - the constituents of the strongly interacting quark-gluon plasma (sQGP) are massive and off-shell quasi-particles (quarks and gluons) with broad spectral functions. In order to address the electromagnetic radiation of the sQGP, we derive off-shell cross sections of qq-bar{yields}{gamma}*, qq-bar{yields}{gamma}*+g and qg{yields}{gamma}*q(q-barg{yields}{gamma}*q-bar) reactions taking into account the effective propagators for quarks and gluons from the DQPM. Dilepton production in In+In collisions at 158 AGeV is studied by implementing these processes into the parton-hadron-string dynamics (PHSD) transport approach. The microscopic PHSD transport approach describes the full evolution of the heavy-ion collision: from the dynamics of quasi-particles in the sQGP phase (when the local energy density is above {approx}1 GeV/fm{sup 3}) through hadronization and to the following hadron interactions and off-shell propagation after the hadronization. A comparison to the data of the NA60 Collaboration shows that the low mass dilepton spectra are well described by including a collisional broadening of vector mesons, while the spectra in the intermediate mass range are dominated by off-shell quark-antiquark annihilation, quark Bremsstrahlung and gluon-Compton scattering in the nonperturbative QGP. In particular, the observed softening of the m{sub T} spectra at intermediate masses (1 GeV {<=} M {<=} 3 GeV) is approximately reproduced.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Corpuscular Diagnosis of the Plasma of Penning Ion Sources

The results of the studies of the energy distribution and atomic-molecular composition of the ions emitted from two Penning ion sources are presented. The transitions between different discharge modes, when the operating pressure and voltage on the anode are changed, are investigated. The energy spectra and mass-charge spectra are measured and the dependences of the fraction of atomic ions on the discharge parameters are determined.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1974

Optical spectra and the mass of SMC X-1

Photographic spectral data are presented for Sanduleak 160, an SMC B-type supergiant with which the strong binary X-ray source SMC X-1 is identified. These data show several important features: (1) Emission is conspicuously present at 4686 A at phases 0.1-0.3 and 0.7-0.85 (where phase 0.0 denotes X-ray eclipse) and undetectable near phase 0.5; (2) the emission has a large amplitude in velocity approximately out of phase with the expected motion of the primary star; (3) the absorption spectrum does not show any detectable change in spectral type throughout the orbit. The basic parameters of the system are studied on the basis of the new data, and a mass of near 2 solar masses is computed for the X-ray object. The data also furnish a number of constraints for models of the system.

Osmer, P. S.↗
NASA NTRS1986

Displaced narrow absorption components in the spectra of mass-losing OB stars - Indications of corotating interaction regions?

The discovery of displaced narrow components (DNCs) in an increasingly large number of stars of various spectral types suggests that an explanation of these features may contribute significantly to understanding of winds from stars of all types. The reported properties of DNCs are summarized here with a view to evaluating one particular scenario for DNC formation which involves corotating interaction regions (CIRs) in the stellar wind. The relevant features of the CIR scenario are summarized, and the extent to which DNC properties support the CIR scenario is discussed.

Mullan, D. J.↗
NASA NTRS1989

Photometric phase functions of common geologic minerals and applications to quantitative analysis of mineral mixture reflectance spectra

The mass fractional abundance of components in intimately mixed, particulate surfaces is calculated from laboratory reflectance spectra using Hapke's (1981) model for bidirectional reflectance. It is found that a simplified version of the model is accurate to within 7 percent for mixtures not containing low albedo components. The model is not appropriate for mixtures with very low and high albedo components. Consideration is given to the possible improvement of the method's accuracy by using an empirical single-particle phase function to describe the scattering characteristics of all minerals, or by solving for the single-particle phase function of the minerals involved exactly using extensive bidirectional reflectance measurements and Hapke's equations for bidirectional reflectance. Also, the results are used to examine the general scattering behavior of particulate mineral surfaces.

Mustard, John F.↗
DOE OSTI2022

CFM-ID 4.0 – a web server for accurate MS-based metabolite identification

The CFM-ID 4.0 web server (https://cfmid.wishartlab.com) is an online tool for predicting, annotating and interpreting tandem mass (MS/MS) spectra of small molecules. It is specifically designed to assist researchers pursuing studies in metabolomics, exposomics and analytical chemistry. More specifically, CFM-ID 4.0 supports the: 1) prediction of electrospray ionization quadrupole time-of-flight tandem mass spectra (ESI-QTOF-MS/MS) for small molecules over multiple collision energies (10 eV, 20 eV, and 40 eV); 2) annotation of ESI-QTOF-MS/MS spectra given the structure of the compound; and 3) identification of a small molecule that generated a given ESI-QTOF-MS/MS spectrum at one or more collision energies. The CFM-ID 4.0 web server makes use of a substantially improved MS fragmentation algorithm, a much larger database of experimental and in silico predicted MS/MS spectra and improved scoring methods to offer more accurate MS/MS spectral prediction and MS/MS-based compound identification. Compared to earlier versions of CFM-ID, this new version has an MS/MS spectral prediction performance that is ~22% better and a compound identification accuracy that is ~35% better on a standard (CASMI 2016) testing dataset. CFM-ID 4.0 also features a neutral loss function that allows users to identify similar or substituent compounds where no match can be found using CFM-ID’s regular MS/MS-to-compound identification utility. Finally, the CFM-ID 4.0 web server now offers a much more refined user interface that is easier to use, supports molecular formula identification (from MS/MS data), provides more interactively viewable data (including proposed fragment ion structures) and displays MS mirror plots for comparing predicted with observed MS/MS spectra. These improvements should make CFM-ID 4.0 much more useful to the community and should make small molecule identification much easier, faster, and more accurate.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1977

A versatile detector system to measure the change states, mass compositions and energy spectra of interplanetary and magnetosphere ions

An instrument is described for measuring the mass and charge state composition as well as the energy spectra and angular distributions of 0.5 to 350 kev/charge ions in interplanetary space and in magnetospheres of planets such as Jupiter and earth. Electrostatic deflection combined with a time-of-flight and energy measurement allows three-parameter analysis of output signals from which the mass, charge states, and energy are determined. Post-acceleration by 30 kV extends the energy range of the detector system into the solar wind and magnetosphere plasma regime. Isotopes of H and He are easily resolved as are individual elements up to Ne and the dominant elements up to and including Fe. This instrument has an extremely large dynamic range in intensity and is sensitive to rare elements even in the presence of high intensity radiation, and is adapted for interplanetary, deep-space, and out-of-the-ecliptic missions, as well as for flights on spacecraft orbiting Jupiter and earth.

Gloeckler, G.↗
DOE OSTI2013

Finite unified theories and their predicitions

All-loop Finite Unified Theories (FUTs) are very interesting N = 1 supersymmetric Grand Unified Theories (GUTs) realising an old field theory dream, and moreover have a remarkable predictive power due to the required reduction of couplings. The reduction of the dimensionless couplings in N = 1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exist RGI relations among dimensional couplings that guarantee the vanishing of all beta-functions in certain N = 1 GUTs even to all orders. Additional developments in the soft supersymmetry breaking sector of N = 1 GUTs and FUTs lead to exact RGI relations, i.e. reduction of couplings, in this dimensionful sector of the theory, too. Based on the above theoretical framework phenomenologically consistent FUTs have been constructed. Here we review two FUT models based on the SU(5) gauge group. Confronting their predictions with the top and bottom quark masses and other experimental constraints a light Higgs-boson mass in the range M{sub H} ∼ 121–126 GeV has been predicted, in striking agreement with the recent experimental results from ATLAS and CMS. Furthermore naturally a relatively heavy s-spectrum emerged with coloured supersymmetric particles above ∼1.5 TeV in agreement with the non-observation of those particles at the LHC. Restricting further the parameter space of the best version of the SU(5) FUT according to the reported accuracy of the Higgs boson mass and B-physics observables we find predictions for the rest of the Higgs masses and the s-spectrum.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

MS2Planner: improved fragmentation spectra coverage in untargeted mass spectrometry by iterative optimized data acquisition

Motivation: Untargeted mass spectrometry experiments enable the profiling of metabolites in complex biological samples. The collected fragmentation spectra are the metabolite’s fingerprints that are used for molecule identification and discovery. Two main mass spectrometry strategies exist for the collection of fragmentation spectra: data-dependent acquisition (DDA) and data-independent acquisition (DIA). In the DIA strategy, all the metabolites ions in predefined mass-to-charge ratio ranges are co-isolated and co-fragmented, resulting in multiplexed fragmentation spectra that are challenging to annotate. In contrast, in the DDA strategy, fragmentation spectra are dynamically and specifically collected for the most abundant ions observed, causing redundancy and sub-optimal fragmentation spectra collection. Yet, DDA results in less multiplexed fragmentation spectra that can be readily annotated. Results: We introduce the MS2Planner workflow, an Iterative Optimized Data Acquisition strategy that optimizes the number of high-quality fragmentation spectra over multiple experimental acquisitions using topological sorting. Our results showed that MS2Planner increases the annotation rate by 38.6% and is 62.5% more sensitive and 9.4% more specific compared to DDA. Availability and implementation MS2Planner code is available at https://github.com/mohimanilab/MS2Planner. The generation of the inclusion list from MS2Planner was performed with python scripts available at https://github.com/lfnothias/IODA_MS.

47 OTHER INSTRUMENTATION↗
NASA NTRS2011

Application of Laser Mass Spectrometry to Art and Archaeology

REMPI laser mass spectrometry is a combination of resonance enhanced multiphoton ionization spectroscopy and time of flight mass spectrometry, This technique enables the collection of mass specific optical spectra as well as of optically selected mass spectra. Analytes are jet-cooled by entrainment in a molecular beam, and this low temperature gas phase analysis has the benefit of excellent vibronic resolution. Utilizing this method, mass spectrometric analysis of historically relevant samples can be simplified and improved; Optical selection of targets eliminates the need for chromatography while knowledge of a target's gas phase spectroscopy allows for facile differentiation of molecules that are in the aqueous phase considered spectroscopically indistinguishable. These two factors allow smaller sample sizes than commercial MS instruments, which in turn will require less damage to objects of antiquity. We have explored methods to optimize REMPI laser mass spectrometry as an analytical tool to archaeology using theobromine and caffeine as molecular markers in Mesoamerican pottery, and are expanding this approach to the field of art to examine laccaic acid in shellacs.

Gulian, Lase Lisa E.↗