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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Theory and Simulation of Ultrafast Multidimensional Nonlinear X-ray Spectroscopy of Molecules (Final Report)

Emerging X-ray free electron laser (XFEL) beam sources offer new types of probes of matter with unprecedented spatial and temporal resolutions. These experimental advances must be met by robust theoretical and computational tools that provide predictive modeling capacity of the underlining electronic and structural dynamics. The latter will be essential for the design of sophisticated multi-pulse experiments and for their interpretation. The proposed research effort will focus on developing cutting- edge simulation tools for nonlinear multidimensional X-ray/optical spectroscopies and aims to address key questions in Priority Research Opportunities 1 (Probing and controlling electron motion within a molecule) and 3 (Capturing rare events and intermediate states in the transformation of matter) as mentioned in the BES Roundtable Report “Opportunities for Basic Research at the Frontiers of XFEL Ultrafast Science”. XFEL multidimensional nonlinear techniques, which combine sequences of X-ray and possibly optical pulses, provide a unique experimental toolbox for probing the dynamics of core and valence electronic excitations, as well as material structure. Predictive modeling of these dynamical processes requires the combination of analytical theory for nonlinear interactions of light and matter, robust quantum-chemical methodologies for the accurate description of electronic structure of various materials, and multiscale ab initio electron and nuclear dynamics techniques operating beyond Born-Oppenheimer approximation. These challenges will be addressed with three research thrusts (i) Develop and implement theoretical apparatus for modeling a broad range of multidimensional spectroscopic techniques enabled by present and upcoming XFEL facilities. This thrust also includes the incorporation of a computational module in the DOE supported open-source NWChem computational chemistry package as well as the development of other open-source codes ready for dissemination across a broad user base; (ii) Propose and design new multi-pulse experiments that make use of the capabilities of the incoming LCLS-II facility; (iii) Perform selected applications to specific molecular systems that can be carried out at LCLS-II and demonstrate how these X-ray sources may be used to study nonadiabatic dynamics through conical interactions, electronic correlations in multi-core excitons, and charge transfer/energy transfer processes. The proposed research will be carried out by a multi-disciplinary four-institution research team which combines academia and national laboratories and spans the broad and necessary expertise in theoretical spectroscopy, nonlinear optics, quantum chemistry, molecular non-adiabatic dynamics and code development. The work will be performed in a highly interactive team environment with junior researchers shared between institutions thus cementing cross- disciplinary interactions. The developed simulation tools will be immediately deployed for XFEL facility users, both experimentalists and theorists, via freely distributed codes and databases. Altogether, this project will facilitate establishing XFEL-based multidimensional spectroscopies as a novel diagnostic tool for monitoring electronic and structural dynamics in molecular materials.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2022

Update of CEA DES Criticality-Safety Activities and Perspectives [Slides]

Neutronics staff at CEA DES are in charge of a whole set of modeling and simulation tools for neutronics: nuclear data evaluation and processing, transport codes development, calculation sequences edition, verification, validation and uncertainty analysis. Advanced user groups are in charge of specific nuclear analysis in reactor physics, fuel cycle, criticality-safety, radiation shielding and nuclear instrumentation for CEA and its partners, at all stages of nuclear facilities life cycle. CEA is willing to participate/collaborate on the following issues: detector design, experiments, analysis and evaluation, DH validation by combining TAGS measurements with Fission Yield variance-covariance matrices.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Initiating Event Rates at U.S. Nuclear Power Plants, 2021 Update

Analyzing initiating event rates is important because it indicates trends and patterns of plant performance and provides inputs to several U.S. Nuclear Regulatory Commission (NRC) risk-informed regulatory activities. This report presents an analysis of initiating event frequencies at U.S. commercial nuclear power plants from calendar year 1988 through 2021, as reported in licensee event reports. Engineers with nuclear power plant experience reviewed each event report since the last update to this report to categorize and characterize reactor trips. To be included in this study, an event had to meet all of the following criteria: (1) the event included an unplanned reactor trip (not a scheduled reactor trip on the daily operations schedule), (2) the sequence of events started when the reactor was critical and at or above the point of adding heat, (3) the event occurred at a U.S. commercial nuclear power plant (excluding Fort St. Vrain and LaCrosse), and (4) the event was reported by a licensee event report. Sixteen initiating event groupings are trended and displayed. For some of the categories, relevant events are plotted separately for boiling-water reactors (BWR) and pressurized-water reactors (PWR). P-values are given for the possible presence of a trend over the most recent 10 years. The following trends were identified for the most recent 10 years (2012–2021): • A highly statistically significant decreasing trend was identified for Loss of Offsite Power (p-value = 0.002) • A statistically significant decreasing trend was identified for BWR general transients (p-value = 0.025) • A statistically significant decreasing trend was identified for PWR general transients for the second year in a row (p-value = 0.038).

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Initiating Event Rates at U.S. Nuclear Power Plants: 2022 Update

Analyzing initiating event rates is important because it indicates trends and patterns of plant performance and provides inputs to several U.S. Nuclear Regulatory Commission (NRC) risk-informed regulatory activities. This report presents an analysis of initiating event frequencies at U.S. commercial nuclear power plants from calendar year 1988 through 2022, as reported in licensee event reports. Engineers with nuclear power plant experience reviewed each event report since the last update to this report to categorize and characterize reactor trips. To be included in this study, an event had to meet all of the following criteria: (1) the event included an unplanned reactor trip (not a scheduled reactor trip on the daily operations schedule), (2) the sequence of events started when the reactor was critical and at or above the point of adding heat, (3) the event occurred at a U.S. commercial nuclear power plant (excluding Fort St. Vrain and LaCrosse), and (4) the event was reported by a licensee event report. Sixteen initiating event groupings are trended and displayed. For some of the categories, relevant events are plotted separately for boiling-water reactors (BWR) and pressurized-water reactors (PWR). P-values are given for the possible presence of a trend over the most recent 10 years.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1985

Testing of a failure accommodation system on a highly flexible grid

This paper presents a scheme for on-line failure detection in systems with appreciable structural dynamics. The design is suboptimal because of extensive computational requirements of optimal schemes. To accomplish failure detection, the innovations sequence of a finite order Kalman filter is examined. Because of the heavy dependence of the system on the zero-mean character of the innovations sequence of the filter much attention has been given to the design and evaluation of the Kalman filters used. The filter designs are based on modal models of the structural dynamics. Two modal models were considered, one based on an analytic finite element model and the other based on empirically derived frequency and damping. Experiments using a grid structure are presented which illustrate operation and performance of the filter designs based on these models. The general character of the results presented is that appreciable errors exist in the filter design based on the finite element model. Substantial improvement results if the design model is modified to include empirically derived frequency and damping.

Montgomery, R. C.↗
NASA NTRS2011

Molecular Gas in Young Debris Disks

Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. Interestingly, the debris disk around the young main-sequence star 49 Ceti possesses a substantial amount of molecular gas and possibly represents the missing link between the two phases. Motivated to understand the evolution of the gas component in circumstellar disks via finding more 49 Ceti-like systems, we carried out a CO J = 3-2 survey with the Atacama Pathfinder EXperiment, targeting 20 infrared-luminous debris disks. These systems fill the gap between primordial and old tenuous debris disks in terms of fractional luminosity. Here we report on the discovery of a second 49 Ceti-like disk around the 30 Myr old A3-type star HD21997, a member of the Columba Association. This system was also detected in the CO(2-1) transition, and the reliable age determination makes it an even clearer example of an old gas-bearing disk than 49 Ceti. While the fractional luminosities of HD21997 and 49 Ceti are not particularly high, these objects seem to harbor the most extended disks within our sample. The double-peaked profiles of HD21997 were reproduced by a Keplerian disk model combined with the LIME radiative transfer code. Based on their similarities, 49 Ceti and HD21997 may be the first representatives of a so far undefined new class of relatively old > or approx.8 Myr), gaseous dust disks. From our results, neither primordia1 origin nor steady secondary production from icy planetesima1s can unequivocally explain the presence of CO gas in the disk ofHD21997.

Moor, A.↗
NASA NTRS2012

Supercritical Water Mixture (SCWM) Experiment

The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

Hicks, Michael C.↗
NASA NTRS2011

Cassini Mission Sequence Subsystem (MSS)

This paper describes my work with the Cassini Mission Sequence Subsystem (MSS) team during the summer of 2011. It gives some background on the motivation for this project and describes the expected benefit to the Cassini program. It then introduces the two tasks that I worked on - an automatic system auditing tool and a series of corrections to the Cassini Sequence Generator (SEQ_GEN) - and the specific objectives these tasks were to accomplish. Next, it details the approach I took to meet these objectives and the results of this approach, followed by a discussion of how the outcome of the project compares with my initial expectations. The paper concludes with a summary of my experience working on this project, lists what the next steps are, and acknowledges the help of my Cassini colleagues.

solstice mission↗
DOE OSTI2021

A Robust Yule-Walker Method for Online Monitoring of Power System Electromechanical Modes of Oscillation

Reliable power system operation requires that system operators maintain a satisfactory small-signal stability margin at all times. Mode meters allow system operators to continuously monitor the stability margin by analyzing synchrophasor measurements. Experience with mode meters at the Bonneville Power Administration (BPA) has revealed that mode meters sometimes suffer severe bias following transient disturbances. In this paper, a robust version of the Yule-Walker mode meter algorithm is proposed to mitigate this bias. The robust capability is introduced by modifying the estimator of the autocovariance sequence (ACS) on which the algorithm depends. Tests with field-measured data demonstrate that the robust Yule-Walker (RYW) algorithm significantly outperforms its conventional counterpart and is better able to provide system operators with accurate information about the system's stability margin.

Follum, James D.↗
NASA NTRS1972

Analyses of requirements for computer control and data processing experiment subsystems. Volume 2: ATM experiment S-056 image data processing system software development

The IDAPS (Image Data Processing System) is a user-oriented, computer-based, language and control system, which provides a framework or standard for implementing image data processing applications, simplifies set-up of image processing runs so that the system may be used without a working knowledge of computer programming or operation, streamlines operation of the image processing facility, and allows multiple applications to be run in sequence without operator interaction. The control system loads the operators, interprets the input, constructs the necessary parameters for each application, and cells the application. The overlay feature of the IBSYS loader (IBLDR) provides the means of running multiple operators which would otherwise overflow core storage.

Source record↗
NASA NTRS1977

ADRF experiments using near n.pi pulse strings

Adiabatic demagnetization (ADRF) can be achieved in a dipolar coupled nuclear spin system in solids by applying a string of short RF pulses and gradually modulating the pulse amplitudes or pulse angles. This letter reports an adiabatic inverse polarization effect in solids and a rotary spin echo phenomenon observed in liquids when the pulse angle is gradually changed across integral multiples of pi during a string of RF pulses. The RF pulse sequence used is illustrated along with the NMR signal from a CaF2 single crystal as observed between the RF pulses and the rotary spin echo signal observed in liquid C6F6 for n = 2. The observed effects are explained qualitatively on the basis of average Hamiltonian theory.

Rhim, W. K.↗
DOE OSTI2024

Dissecting neurofilament tail sequence-phosphorylation-structure relationships with multicomponent reconstituted protein brushes

Neurofilaments (NFs) are multisubunit, bottlebrush-shaped intermediate filaments abundant in the axonal cytoskeleton. Each NF subunit contains a long intrinsically disordered tail domain, which protrudes from the NF core to form a “brush” surrounding each NF. Precisely how the tails’ variable charge patterns and repetitive phosphorylation sites mediate their conformation within the brush remains an open question in axonal biology. We address this problem by grafting recombinant NF tail protein constructs NF-Light, -Medium, and -Heavy (NFL, NFM, and NFH) to surfaces, yielding protein brushes of defined stoichiometry that can be phosphorylated in vitro. Atomic force microscopy measurements reveal that brush height depends on composition monotonically but not always linearly for binary NFL:NFM or NFL:NFH systems, and that NFM-based brushes are highly extended, while brushes incorporating the much larger NFH are surprisingly compact even after multisite phosphorylation. Complementary self-consistent field theory (SCFT) predicts multilayer brush morphologies for NFM and phosphorylated NFH brushes. Further experiments and SCFT analysis with designed mutants reveal that N-terminal negative charges in the NFH tail repel phosphorylated residues to generate the multilayer morphology, while the C-terminal charge-neutral region contributes to multilayer brush morphology but not total brush height. Charge-shuffled NFM variants show that charge segregation promotes brush collapse near physiological ionic strengths. Collectively, this study supports a role for NFM in establishing a dynamic range for NF brush conformation, lending insight into previous in vitro and in vivo findings. More broadly, this work establishes a platform for dissecting contributions of disordered protein sequence to conformation at interfaces.

Science & Technology - Other Topics↗
DOE OSTI2022

Bioinformatics and 3D Structural Analysis of the Coronavirus Main Protease Active Site Diversity

Coronaviruses (Coronaviridae) such as SARS‐CoV‐2 (severe acute respiratory syndrome coronavirus) and MERS‐CoV (Middle East respiratory syndrome coronavirus) have been the source of recent outbreaks and global health concerns. While vaccines have been essential for controlling the SARS‐CoV‐2 (COVID‐19) pandemic, it is uncertain whether they will be effective against future coronavirus strains. Therefore, identification or design of a broad‐spectrum drug that targets highly conserved regions of the main protease of multiple coronavirus strains is essential in the long term. As part of a virtual summer research experience with the RCSB PDB, bioinformatics tools were employed to predict and construct 3D models of the coronavirus main protease (MPro) using SARS‐CoV‐2 as the template, with a focus on mutational trends and active sites. This study focused on the active sites of MPro, a cysteine protease essential for viral assembly and replication. Sequence alignments and structure modeling of MPro structures has identified conserved regions across multiple coronavirus strains. Inhibition of MPro halts coronavirus replication, making it an ideal drug target, and studies of MPro may foster and accelerate the discovery of high affinity broad‐spectrum drugs.

Wu Wu, Amy↗
DOE OSTI2025

Future Circular Collider Feasibility Study Report

In response to the 2020 Update of the European Strategy for Particle Physics , the Future Circular Collider (FCC) Feasibility Study was launched as an international collaboration hosted by CERN. This report describes the FCC integrated programme , which consists of two stages: an electron-positron collider (FCC-ee) in the first phase, serving as a high-luminosity Higgs, top, and electroweak factory; followed by a proton-proton collider (FCC-hh) at the energy frontier in the second phase. The FCC-ee is designed to operate at four key centre-of-mass energies: the Z pole, the WW pair production threshold, the ZH production peak, and the top/anti-top production threshold—each delivering the highest possible luminosities to four experiments. Over 15 years of operation, FCC-ee will produce more than 6 trillion Z bosons, 200 million WW pairs, nearly 3 million Higgs bosons, and 2 million top anti-top pairs. Precise energy calibration at the Z pole and WW threshold will be achieved through frequent resonant depolarisation of pilot bunches. The sequence of operation modes between the Z, WW, and ZH substages remains flexible. The FCC-hh will operate at a centre-of-mass energy of approximately 85 TeV—nearly an order of magnitude higher than the LHC—and is designed to deliver 5 to 10 times the integrated luminosity of the upcoming High-Luminosity LHC. Its mass reach for direct discovery extends to several tens of TeV. In addition to proton-proton collisions, the FCC-hh is capable of supporting ion-ion, ion-proton, and lepton-hadron collision modes. This second volume of the Feasibility Study Report presents the complete design of the FCC-ee collider, its operation and staging strategy, the full-energy booster and injector complex, required accelerator technologies, safety concepts, and technical infrastructure. It also includes the design of the FCC-hh hadron collider, development of high-field magnets, hadron injector options, and key technical systems for FCC-hh.

Benedikt, M. [European Organization for Nuclear Re↗
NASA NTRS1978

Mars meteorology - Three seasons at the surface

We summarize some meteorological results from Viking for northern summer, autumn and winter. Little Sol-to-Sol meteorological change was observed during summer, except for secular pressure change. However, a regular sequence of weather disturbances, interpreted as baroclinic waves, appeared primarily at VL-2 during autumn and winter. The number of Rossby waves present at a given instant is calculated to be 4 and 6 for these seasons. The extreme regularity and low wave number make these systems closely resemble the baroclinic waves of rotating annulus experiments.

Ryan, J. A.↗
NASA NTRS1997

Identification of the prooxidant site of human ceruloplasmin: a model for oxidative damage by copper bound to protein surfaces

Free transition metal ions oxidize lipids and lipoproteins in vitro; however, recent evidence suggests that free metal ion-independent mechanisms are more likely in vivo. We have shown previously that human ceruloplasmin (Cp), a serum protein containing seven Cu atoms, induces low density lipoprotein oxidation in vitro and that the activity depends on the presence of a single, chelatable Cu atom. We here use biochemical and molecular approaches to determine the site responsible for Cp prooxidant activity. Experiments with the His-specific reagent diethylpyrocarbonate (DEPC) showed that one or more His residues was specifically required. Quantitative [14C]DEPC binding studies indicated the importance of a single His residue because only one was exposed upon removal of the prooxidant Cu. Plasmin digestion of [14C]DEPC-treated Cp (and N-terminal sequence analysis of the fragments) showed that the critical His was in a 17-kDa region containing four His residues in the second major sequence homology domain of Cp. A full length human Cp cDNA was modified by site-directed mutagenesis to give His-to-Ala substitutions at each of the four positions and was transfected into COS-7 cells, and low density lipoprotein oxidation was measured. The prooxidant site was localized to a region containing His426 because CpH426A almost completely lacked prooxidant activity whereas the other mutants expressed normal activity. These observations support the hypothesis that Cu bound at specific sites on protein surfaces can cause oxidative damage to macromolecules in their environment. Cp may serve as a model protein for understanding mechanisms of oxidant damage by copper-containing (or -binding) proteins such as Cu, Zn superoxide dismutase, and amyloid precursor protein.

NASA Discipline Regulatory Physiology↗
DOE OSTI2020

Impact of Inverter Based Resource Negative Sequence Current Injection on Transmission System Protection

This report documents the results of analysis performed to investigate the impact of inverter-based resource (IBR) response to unbalanced faults on transmission system protective relay dependability and security. Electromagnetic transient (EMT) simulations were performed to simulate IBR response to these faults using existing manufacturer-developed EMT models for four separate IBRs. The study team was composed of IBR manufacturers, relay manufacturers, transmission providers, reliability coordinators and industry consultants with experience in EMT simulation and system protection. The results indicate that under certain conditions, IBR response can result in protective relay misoperations if current protection practices, which were developed based on conventional power sources, are not adapted to the characteristics of IBRs.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRSDate not supplied

Spaceflight Autonomous Multigenerational Microbial Sequencer in Support of Plant-Growth Systems

The CubeSat platform has proven successful in obtaining meaningful life science information when biological payloads are incorporated. Examples include: 1) the first-ever CubeSat with a biological payload, GeneSat-1, which demonstrated decreased growth rates for flight samples of Escherichia coli in low Earth orbit (Parra et al. 2008); 2) PharmaSat, demonstrated that Saccharomyces cerevisiae in the microgravity environment exhibits a significant level of metabolic activity even at high doses of applied antifungal (Ricco et al. 2011); 3) O/OREOS, which used Bacillus subtilis(bacteria) to demonstrate for the first time that microorganisms can be loaded in a dried, dormant form and then rehydrated and grown in orbit months after launch (Nicholson et al. 2011; Ehrenfreund et al. 2014; 4) the SporeSat payload, which investigated Ceratopteris richardii(fern spores) using lab-on-a-chip devices (BioCDs) and minicentrifuges to produce artificial gravitational forces in ground studies (Park et al. 2017), with demonstration of the BioCD and minicentrifuge in space; 5) EcAMSat, the first CubeSat to be directly deployed from the ISS for an experiment assessing antibiotic resistance of E. coli in the microgravity environment (Padgen et al. 2020); 6) BioSentinel, exposed a culture of yeast to galactic cosmic radiation (GCR) and solar particle events while in heliocentric orbit to measure the rate of double-strand-break repair using DNA-repair-deficient mutants. This effort measures the metabolic parameters of yeast in a deep-space environment compared to Earth ambient conditions using a 3-color LED detection system (Ricco et al. 2020; Padgen et al. 2021). We aim to expand this list to include a Spaceflight Autonomous Multigenerational Microbial Sequencer (SAMMS). SAMMS will allow for the genome level understanding of changes in growth and metabolic activity for any organism. While microbes are suitable for early studies in our proposed platform because of their small size, small and relatively less-complicated genomes, fast generation times, and relevance to life support systems; multicellular organisms can similarly be evaluated for their genetic response to the spaceflight environment. The Spaceflight Autonomous Multigenerational Microbial Sequencer (SAMMS) will enable autonomous sequencing of biological samples in plant production units, cislunar orbit and on the lunar surface to examine spaceflight effects (ie. radiation, altered gravity, reduced pressures) on plant and microbial genomes.On this team a Kennedy Space Center (KSC) space crop production and water systems microbiologist/molecular biologist works with a Johnson Space Center (JSC) International Space Station (ISS) microbial sequencing expert and an Ames Research Center (ARC) CubeSat Engineering team to convert an automated Oxford Nanopore librarypreparation and sequencing method to a fluidic CubeSat payload system. The Oxford Nanopore MinION sequencing platform has proven successful in the spaceflight environment onboard the ISS (Stahl-Rommel et al. 2021). Further long-duration spaceflight and exposure to high levels of radiation will cause genotypic effects in biological organisms that may affect their function. Monitoring the adaption of a population to the spaceflight environment and any subsequent beneficial mutations will allow for the harnessing of organisms best suited for use in life support systems. This will ensure that the selected life support-essential microorganisms maintain their intended specified function over generations of culturing in the relevant spaceflight environment without becoming hazardous to crew or spacecraft systems.

Aubrie E Orourke↗