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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 1,639 records · Page 91
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Design of a compact hard x-ray split-delay system based on variable-gap channelcut crystals

Free Electron Lasers provide unique opportunities in investigating ultrafast atomic-scale dynamics using X-ray Pump X-ray Probe and two-pulse X-ray Speckle Visibility Spectroscopy techniques. However the performance of these techniques critically relies on maintaining the spatial overlap between the two beams at the sample location while adjusting the temporal separation between the two pulses. This presents major challenges for realizing hard X-ray split-delay optics, i.e an optical arrangement capable of generating two X-ray pulses separated in time from a single X-ray pulse. More specifically, it translates into nanoradian-scale angular precision requirements. We present here a hard X-ray split-delay optics concept using 4 channelcut crystals, where the beam path length difference can be adjusted by the linear translation of two crystals having non-parallel gaps. Having two Bragg reflections from the same monolithic crystal in the opposite direction cancels positioning errors from underlying stages. As a result, this concept has lower motion precision requirements on the hardware, and yet leads to significantly higher output beam angular stability. We present a case study for this concept that covers an energy range from 7 to 12 keV and provides a delay range from -3 to 10 ps at 9 keV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Prototype Demonstration of Gamma- Blind Tensioned Metastable Fluid Neutron/Multiplicity/Alpha Detector – Real Time Methods for Advanced Fuel Cycle Applications

The content of this report summarizes a multi-year effort to develop prototype detection equipment using the Tensioned Metastable Fluid Detector (TMFD) technology developed by Taleyarkhan [1]. The context of this development effort was to create new methods for evaluating and developing advanced methods for safeguarding nuclear materials along with instrumentation in various stages of the fuel cycle, especially in material balance areas (MBAs) and during reprocessing of used nuclear fuel. One of the challenges related to the implementation of any type of MBA and/or reprocessing technology (e.g., PUREX or UREX) is the real-time quantification and control of the transuranic (TRU) isotopes as they move through the process. Monitoring of higher actinides from their neutron emission (including multiplicity) and alpha signatures during transit in MBAs and in aqueous separations is a critical research area. By providing on-line real-time materials accountability, diversion of the materials becomes much more difficult. The Tensioned Metastable Fluid Detector (TMFD) is a transformational technology that is uniquely capable of both alpha and neutron spectroscopy while being “blind” to the intense gamma field that typically accompanies used fuel – simultaneously with the ability to provide multiplicity information as well [1-3]. The TMFD technology was proven (lab-scale) as part of a 2008 NERI-C program [1-7]. The bulk of this report describes the advancements and demonstrations made in TMFD technology. One final point to present before turning to the TMFD demonstrations is the context for discussing real-time monitoring of SNM. It is useful to review the spectrum of isotopes generated within nuclear fuel during reactor operations. Used nuclear fuel (UNF) from a light water reactor (LWR) contains fission products as well as TRU elements formed through neutron absorption/decay chains. The majority of the fission products are gamma and beta emitters and they represent the more significant hazards from a radiation protection standpoint. However, alpha and neutron emitting uranium and TRU elements represent the more significant safeguards and security concerns. Table 1.1 presents a representative PWR inventory of the uranium and actinide isotopes present in a used fuel assembly. The uranium and actinide isotopes (chiefly the Pu, Am and Cm elements) are all emitters of alpha particles and some of them release significant quantities of neutrons through spontaneous fissions

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Genome-Wide Identification, Classification, and Expression Analysis of the Hsf Gene Family in Carnation ( Dianthus caryophyllus )

Heat shock transcription factors (Hsfs) are a class of important transcription factors (TFs) which play crucial roles in the protection of plants from damages caused by various abiotic stresses. The present study aimed to characterize the Hsf genes in carnation (Dianthus caryophyllus), which is one of the four largest cut flowers worldwide. In this study, a total of 17 non-redundant Hsf genes were identified from the D. caryophyllus genome. Specifically, the gene structure and motifs of each DcaHsf were comprehensively analyzed. Phylogenetic analysis of the DcaHsf family distinctly separated nine class A, seven class B, and one class C Hsf genes. Additionally, promoter analysis indicated that the DcaHsf promoters included various cis-acting elements that were related to stress, hormones, as well as development processes. In addition, cis-elements, such as STRE, MYB, and ABRE binding sites, were identified in the promoters of most DcaHsf genes. According to qRT-PCR data, the expression of DcaHsfs varied in eight tissues and six flowering stages and among different DcaHsfs, even in the same class. Moreover, DcaHsf-A1, A2a, A9a, B2a, B3a revealed their putative involvement in the early flowering stages. The time-course expression profile of DcaHsf during stress responses illustrated that all the DcaHsfs were heat- and drought-responsive, and almost all DcaHsfs were down-regulated by cold, salt, and abscisic acid (ABA) stress. Meanwhile, DcaHsf-A3, A7, A9a, A9b, B3a were primarily up-regulated at an early stage in response to salicylic acid (SA). This study provides an overview of the Hsf gene family in D. caryophyllus and a basis for the breeding of stress-resistant carnation.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1975

Condensation time of the solar nebula from extinct I-129 in primitive meteorites

Mineral separates from five carbonaceous chondrites were dated by extinct 16 million year I-129, in an attempt to establish the condensation time of the solar nebula. Two Fe3O4 or Fe3O4-FeS samples from the Murchison and Orgueil meteorites are older than any other material dated thus far, and apparently formed within 200,000 years of each other. The great age, close isochronism, and primitive nature of the samples suggest that the event recorded was the condensation stage of the solar nebula. It provides a suitable zero point for the chronology of the early solar system. The I-129/I-127 ratio during condensation of the nebula was (1.46 plus or minus 0.04) times 0.0001. The recrystallized C4 chondrite Karoonda began to retain Xe-129 1.8 plus or minus 0.5 million years after the above event. This short cooling time implies rapid accretion (not exceeding 1 million years) and a shallow origin (not exceeding 10 km) below the surface of its parent body.-

Lewis, R. S.↗
NASA NTRS1991

U-Th-Pb isotopic systematics of lunar norite 78235

A pristine high-Mg noritic cumulate thought to be relict deep-seated lunar crust is studied with an eye to obtaining evidence of initial Pb isotopic composition and U/Pb ratios of early lunar magma sources and possibly of a primary magma ocean. A leaching procedure was conducted on polymineralic separates to assure the removal of secondary Pb components. The Pb from leached separates do not form a linear trend on the Pb-Pb diagram, indicating open-system behavior either from mixtures of Pb or postcrystallization disturbances. Calculated initial Pb compositions and corresponding U-238/Pb-204 (mu) values are presented, with the assumption of reasonably precise radiometric ages from the literature for norite 78236. The results obtained support the contention that high-Mg suite rocks are coeval with the ferroan anorthosites, both being produced during the earliest stages of lunar evolution.

Premo, W. R.↗
DOE OSTI2012

Data Quality Objectives for WTP Feed Acceptance Criteria - 12043

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is under construction for the U.S. Department of Energy by Bechtel National, Inc. and subcontractor URS Corporation (contract no. DE-AC27-01RV14136). The plant when completed will be the world's largest nuclear waste treatment facility. Bechtel and URS are tasked with designing, constructing, commissioning, and transitioning the plant to the long term operating contractor to process the legacy wastes that are stored in underground tanks (from nuclear weapons production between the 1940's and the 1980's). Approximately 56 million gallons of radioactive waste is currently stored in these tanks at the Hanford Site in southeastern Washington. There are three major WTP facilities being constructed for processing the tank waste feed. The Pretreatment (PT) facility receives feed where it is separated into a low activity waste (LAW) fraction and a high level waste (HLW) fraction. These fractions are transferred to the appropriate (HLW or LAW) facility, combined with glass former material, and sent to high temperature melters for formation of the glass product. In addition to PT, HLW and LAW, other facilities in WTP include the Laboratory (LAB) for analytical services and the Balance of Facilities (BOF) for plant maintenance, support and utility services. The transfer of staged feed from the waste storage tanks and acceptance in WTP receipt vessels require data for waste acceptance criteria (WAC) parameters from analysis of feed samples. The Data Quality Objectives (DQO) development was a joint team effort between WTP and Tank Operations Contractor (TOC) representatives. The focus of this DQO effort was to review WAC parameters and develop data quality requirements, the results of which will determine whether or not the staged feed can be transferred from the TOC to WTP receipt vessels. The approach involved systematic planning for data collection consistent with EPA guidance for the seven-step DQO process. Data quality requirements for sample collection and analysis of all WAC parameters were specified during the DQO process. There were eighteen key parameters identified with action limits to ensure the feed transfer and receipt would not exceed plant design, safety, permitting, and processing requirements. The remaining WAC parameters were grouped in the category for obtaining data according to WTP contract specifications, regulatory reporting requirements, and for developing the feed campaign processing sequence. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

WIPP Safety Significant Confinement Ventilation System (SSCVS) HEPA Filtration System - 20165

Construction and major equipment fabrication are underway for a new ventilation exhaust system at the Waste Isolation Pilot Plant (WIPP). The new system will provide continuous High Efficiency Particulate Air (HEPA) filtration of the exhaust from the WIPP underground while meeting the ventilation demands for expanded waste emplacement and mining operations over the next 40 years. The integrated system design provides for reducing the salt, clay and diesel particulates from the exhaust airflow from the mine, prior to full filtration using Nuclear Safety Significant HEPA filters. The SSCVS design and equipment provides for continuous HEPA filtration over a wide range of operating and environmental conditions. The new exhaust system connects to the existing underground exhaust shaft, and the exhaust air flows from the underground through Salt Reduction Units (SRUs) to protect the final filter banks from excessive moisture and rapid salt/dust buildup. Each of the six (6) SRUs consists of a demister to remove entrained moisture, a dry salt remover unit to filter approximately 90% of the entrained salt/dust, and an automated water treatment system to periodically clean the demisters and to remove salt from the SRU filters. At the maximum expected exhaust flowrate of 540,000 Cubic Feet per Minute (CFM) / 255 Cubic Meters per Second (m{sup 3}/s), five (5) salt removal units will be in operation with one unit in standby or maintenance. An in-line variable frequency drive booster fan will offset pressure losses through each SRU and reduce the relative humidity of the air exiting the SRUs. In the event of a high radiation alarm from the underground Continuous Air Monitors (CAMs), the SRUs will be automatically bypassed, which places the SRS and building outside of the Safety Significant confinement boundary. From the SRUs, the exhaust is directed to the HEPA filter banks located in the New Filter Building. The exhaust system is designed to provide continuous HEPA filtration prior to release to the exhaust stack. There are 22 HEPA filter banks rated at 27,000 CFM / 12.75 m{sup 3}/s each. Each filter bank has two stages of pre-filters and two stages of HEPA filters. The filtered air from each of the 22 filter banks discharges into a common concrete plenum, which is maintained under a negative pressure by the main exhaust fans. Six 1,000 HP variable frequency drive exhaust fans are provided on the south side of the plenum. At the maximum expected exhaust flow of 540,000 CFM, four exhaust fans and twenty filter banks will be in operation. The fans discharge vertically to a separate concrete exhaust plenum. The filtered exhaust is routed from the exhaust plenum to a 125-foot-tall exhaust stack via a 13-foot diameter duct. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

A hybrid chemical-biological approach can upcycle mixed plastic waste with reduced cost and carbon footprint

Derived from renewable feedstocks, such as biomass, polylactic acid (PLA) is considered a more environmentally friendly plastic than conventional petroleum-based polyethylene terephthalate (PET). However, PLA must still be recycled, and its growing popularity and mixture with PET plastics at the disposal stage poses a cross-contamination threat in existing recycling facilities and results in low-value and low-quality recycled products. Hybrid upcycling has been proposed as a promising sustainable solution for mixed plastic waste, but its techno-economic and life cycle environmental performance remain understudied. We propose a hybrid upcycling approach using a biocompatible ionic liquid (IL) to first chemically depolymerize plastics and then convert the depolymerized stream via biological upgrading with no extra separation. Here we show that over 95% of mixed PET/PLA was depolymerized into the respective monomers, which then served as the sole carbon source for the growth of Pseudomonas putida, enabling the conversion of the depolymerized plastics into biodegradable polyhydroxyalkanoates (PHAs). In comparison to conventional commercial PHAs, the estimated optimal production cost and carbon footprint are reduced by 62% and 29%, respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Single field double inflation and primordial black holes

Within the framework of scalar-tensor theories, we study the conditions that allow single field inflation dynamics on small cosmological scales to significantly differ from that of the large scales probed by the observations of cosmic microwave background. The resulting single field double inflation scenario is characterised by two consequent inflation eras, usually separated by a period where the slow-roll approximation fails. At large field values the dynamics of the inflaton is dominated by the interplay between its non-minimal coupling to gravity and the radiative corrections to the inflaton self-coupling. For small field values the potential is, instead, dominated by a polynomial that results in a hilltop inflation. Without relying on the slow-roll approximation, which is invalidated by the appearance of the intermediate stage, we propose a concrete model that matches the current measurements of inflationary observables and employs the freedom granted by the framework on small cosmological scales to give rise to a sizeable population of primordial black holes generated by large curvature fluctuations. We find that these features generally require a potential with a local minimum. We show that the associated primordial black hole mass function is only approximately lognormal.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Characterization of DESI fiber assignment incompleteness effect on 2-point clustering and mitigation methods for DR1 analysis

We present an in-depth analysis of the fiber assignment incompleteness in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1). This incompleteness is caused by the restricted mobility of the robotic fiber positioner in the DESI focal plane, which limits the number of galaxies that can be observed at the same time, especially at small angular separations. As a result, the observed clustering amplitude is suppressed in a scale-dependent manner, which, if not addressed, can severely impact the inference of cosmological parameters. We discuss the methods adopted for simulating fiber assignment on mocks and data. In particular, we introduce the fast fiber assignment (FFA) emulator, which was employed to obtain the power spectrum covariance adopted for the DR1 full-shape analysis. We present the mitigation techniques, organised in two classes: measurement stage and model stage. We then use high fidelity mocks as a reference to quantify both the accuracy of the FFA emulator and the effectiveness of the different measurement-stage mitigation techniques. This complements the studies conducted in a parallel paper for the model-stage techniques, namely the θ-cut approach. We find that pairwise inverse probability (PIP) weights with angular upweighting recover the “true” clustering in all the cases considered, in both Fourier and configuration space. Notably, we present the first ever power spectrum measurement with PIP weights from real data.

cosmological simulations↗
DOE OSTI2025

MINE: maximally informative next experiment—toward a new GWAS experimental design and methodology

Abstract The computational methodology of Genome Wide Association Studies (GWAS) currently has several limitations: (i) the number of observations (rows) on a quantitative trait tends to be smaller than the number of single nucleotide polymorphisms (SNPs) (columns) in the design matrix; (ii) each SNP is usually modeled separately, failing to acknowledge interaction between each other (ie epistasis); (iii) there is implicit linkage disequilibrium (LD) between neighboring SNPs due to their linkage. To overcome these issues, we developed a tool that uses ensemble methods to fit mixed linear models to GWAS data, and these ensemble methods include the development of a new experimental design approach in GWAS, which uses the resultant models and data to select the next informative experiment over time. This new adaptive and staged approach for GWAS experimental design was developed and tested in a 3 yr adaptive model-guided discovery experiment against a fixed classical design. In Sorghum bicolor a total of 79, 86, and 78 accessions were tested in years 1, 2, and 3, respectively out of 343 accessions available in the Bioenergy Association Panel (BAP) each identified for 232,303 SNPs, 1 every 2–3 kb in the genomes. We demonstrated the feasibility of MINE enacted with 8 people in the field per year over 3 yr vs in 1 large classical design enacted with 20 people in 1 yr. The MINE results for chromosomal regions identified controlling dry weight were confirmed against results from previous sorghum GWAS experiments and 1 large classical design for the BAP panel.

Genetics & Heredity↗
DOE OSTI2025

Efficient lattice QCD computation of radiative-leptonic-decay form factors at multiple positive and negative photon virtualities

In previous work [D. Giusti, Methods for high-precision determinations of radiative-leptonic decay form factors using lattice QCD, Phys. Rev. D 107, 074507 (2023)], we showed that form factors for radiative leptonic decays of pseudoscalar mesons can be determined efficiently and with high precision from lattice QCD using the “three-dimensional (3D) method,” in which three-point functions are computed for all values of the current insertion time and the time integral is performed at the data-analysis stage. Here, we demonstrate another benefit of the 3D method: the form factors can be extracted for any number of nonzero photon virtualities from the same three-point functions at no extra cost. We present results for the $D_s → ℓνγ*$ vector form factor as a function of photon energy and photon virtuality, for both positive and negative virtuality, for a single ensemble with 340 MeV pion mass and 0.11 fm lattice spacing. In our analysis, we separately consider the two different time orderings and the different quark flavors in the electromagnetic current. We discuss in detail the behavior of the unwanted exponentials contributing to the three-point functions, as well as the choice of fit models and fit ranges used to remove them for various values of the virtuality. While positive photon virtuality is relevant for decays to multiple charged leptons, negative photon virtuality suppresses soft contributions and is of interest in QCD-factorization studies of the form factors.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Process Modeling of U-10wt% Mo Alloys Using Integrated Computational Materials Engineering

Low-enriched uranium alloyed with 10 wt% molybdenum (U-10Mo) has been identified as a promising alternative to highly enriched uranium as fuel for the nation’s high-performance research reactors. Manufacturing the U-10Mo alloy consists of multiple complex thermomechanical processes, which is highly challenging for computational modeling. The integrated computational materials engineering (ICME) concept supports building a microstructure-based framework to investigate the effect of manufacturing processes on the material microstructure. In this report, an ICME model that combines homogenization, hot rolling, annealing, and cold rolling is presented as an example of implementing the ICME concept for modeling the manufacturing processes of the U-10Mo alloy. The integrated model enables information to be passed between the different model components, leading to an improved prediction and a better understanding of microstructure across multiple processes. The integrated model was also implemented to investigate the variation of chemical composition, thickness of the zirconium interlayer, grain growth, and carbide redistribution and fracture of U-10Mo during the thermomechanical processes. With the homogenization model, a molybdenum concentration map can be reconstructed from any given microstructure, and the homogenization time needed to reach a desired homogenization level can also be approximated. The microstructure-based finite-element rolling model, shows that the homogenization process reduces the nonuniformity in the thickness of the zirconium interlayers on the U-10Mo. With the output from the rolling model, a statistical analysis of second-phase hard particles was conducted to quantify the particle redistribution and interparticle spacing between carbides during the deformation. Also, new stringer identification criteria were proposed to predict the correlation between stringer volume fractions and hot-rolling reduction. A macro-finite-element method hot-rolling model showed that higher reduction passes can be achieved within the mill separation force range, and a new “aggressive” rolling schedule was proposed. The model also showed the importance of can material on the quality of rolled foils, with stronger can materials resulting in hot-rolled U-10Mo free of defects (waviness, dog-boning). The deformation-induced recrystallization model demonstrated capability to use inputs from deformation simulations of strain accumulation in U-10Mo samples to predict grain growth behavior of the fuel during thermal treatment stages. Finally, a plane-strain compression mode simulated particle fracture and calculates the void volume fraction generated during cold rolling. The macro-finite-element method cold-rolling model showed that smaller diameter rolls are necessary to achieve the desired foil thickness.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

ParaChoice Model

Sandia National Laboratories' (SNL's) Parametric Choice Model (ParaChoice) supports the U.S. Department of Energy Vehicle Technologies Office (VTO) mission. Using early-stage research as input, ParaChoice supports the informed development of technology that will improve affordability of transportation, while encouraging innovation and reducing dependence on petroleum. Analysis with ParaChoice enables exploration of key factors that influence consumer choice, as well as projecting the effects of technology, fuel, and infrastructure development for the vehicle fleet mix. Because of the distinct differences between requirements, needs, and use patterns for light duty vehicles (LDVs) relative to heavy duty vehicles (HDVs), this project separately models the dynamics of each of these segments to accurately characterize the factors that influence technology adoption.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

Lab and Field Warming Similarly Advance Germination Date and Limit Germination Rate for High and Low Elevation Provenances of Two Widespread Subalpine Conifers

Accurately predicting upslope shifts in subalpine tree ranges with warming requires understanding how future forest populations will be affected by climate change, as these are the seed sources for new tree line and alpine populations. Early life history stages are particularly sensitive to climate and are also influenced by genetic variation among populations. Here, we tested the climate sensitivity of germination and initial development for two widely distributed subalpine conifers, using controlled-environment growth chambers with one temperature regime from subalpine forest in the Colorado Rocky Mountains and one 5 °C warmer, and two soil moisture levels. We also tracked germination rate and timing, rate of seedling development, and seedling morphology for two seed provenances separated by ~300 m elevation. Warming advanced germination timing and initial seedling development by a total of ~2 weeks, advances comparable to mean differences between provenances. Advances were similar for both provenances and species; however, warming reduced the overall germination rate, as did low soil moisture, only for Picea engelmannii. A three-year field warming and watering experiment planted with the same species and provenances yielded responses qualitatively consistent with the lab trials. Altogether these experiments indicate that in a warmer, drier climate, P. engelmannii germination, and thus regeneration, could decline, which could lead to declining subalpine forest populations, while Pinus flexilis forest populations could remain robust as a seed source for upslope range shifts.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2009

Apollo Spacecraft and Saturn V Launch Vehicle Pyrotechnics/Explosive Devices

The Apollo Mission employs more than 210 pyrotechnic devices per mission.These devices are either automatic of commanded from the Apollo spacecraft systems. All devices require high reliability and safety and most are classified as either crew safety critical or mission critical. Pyrotechnic devices have a wide variety of applications including: launch escape tower separation, separation rocket ignition, parachute deployment and release and electrical circuit opening and closing. This viewgraph presentation identifies critical performance, design requirements and safety measures used to ensure quality, reliability and performance of Apollo pyrotechnic/explosive devices. The major components and functions of a typical Apollo pyrotechnic/explosive device are listed and described (initiators, cartridge assemblies, detonators, core charges). The presentation also identifies the major locations and uses for the devices on: the Command and Service Module, Lunar Module and all stages of the launch vehicle.

Interbartolo, Michael↗
DOE OSTI2018

Oxidation and extraction of Am(VI) using a monoamidic extractant in 3D printed centrifugal contactors

In this study, a series of tests were performed using centrifugal contactors to evaluate the separation of Am(VI) from cerium, as well as to determine the efficiency of the contactors. All experiments were performed using 2-cm, acrylic 3D-printed centrifugal contactors. Solvent extraction tests were performed using 1 M N,N-di(2-ethylhexyl)butyramide (DEHBA)/dodecane and a nitric acid feed solution spiked with 243 Am and 139 Ce and oxidized with 60 mg mL -1 sodium bismuthate. Approximately 72 % of the Am was extracted with a single contactor stage. Co-stripping of Am and Ce was demonstrated but attempts at selective stripping were not successful. Lastly, successful recycle of the used organic phase was demonstrated. Contactor efficiencies of 95-100% were obtained.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗