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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 OSTI2014

Identification of process related trace level impurities in the actinide decorporation agent 3,4,3-LI(1,2-HOPO): Nozzle–skimmer fragmentation via ESI LC–QTOFMS

We report that 3,4,3-LI(1,2-HOPO) is a chelating ligand and decorporation agent that can remove radioactive lanthanides and actinides from the body. Identification of trace impurities in drug samples is gaining much interest due to their significant influence on drug activity. In this study, trace impurities were detected in manufactured lots of 3,4,3-LI(1,2-HOPO) by a developed method of Liquid Chromatography coupled with photo-diode array UV detection and Electrospray Ionization-Quadrupole Time of Flight Mass spectrometry (LC-QTOFMS), via induced-in-source or collision-induced mass fragmentation (Nozzle-Skimmer Fragmentation). Molecular ions were fragmented within the nozzle-skimmer region of electrospray ionization (ESI) mass spectrometer equipped with a Time of Flight detector. Eight major (detected at levels higher than a 0.1% threshold) and seven minor trace impurities were identified. The respective structures of these impurities were elucidated via analysis of the generated fragment ions using mass fragmentation and elemental composition software. Proposed structures of impurities were further confirmed via isotopic modeling.

3,4,3-LI(1,2-HOPO) ligand↗
DOE OSTI2014

Active-Interrogation Measurements of Fast Neutrons from Induced Fission in Low-Enriched Uranium

A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre (JRC) in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutron to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Unveiling damage mechanisms of chromium-coated zirconium-based fuel claddings at LWR operating temperature by in-situ digital image correlation

Here, we investigate the coupled thermomechanical fracture mechanisms of coated nuclear fuel claddings at Light Water Reactor (LWR) operating temperatures. These coated claddings are a highly attractive, near-term solution, which addresses the demands for accident-tolerant fuel systems and provide greater oxidation resistance. However, the fracture mechanisms of these coatings, which may create channels for oxidation ingression, must be fully understood prior to implementation. Thus, high-temperature expanding plug experiments were conducted on coated cladding specimens at a temperature of 315 °C, consistent with the operating environment of LWRs. Furthermore, in-situ thermomechanical deformation was measured with stereo digital image correlation during heating and mechanical testing to separately resolve contributions of thermal and mechanical strain. Digital image correlation, supported by acoustic emissions (AE) detection, was also leveraged to track cracking activity during loading. Coating fracture was found to initiate at total hoop strains of 0.34%. The thermal deformation of the coated claddings was investigated via finite element simulations, revealing a bidirectional stress-state within the coating with axial and circumferential strains of 0.026 and 0.031%. This bidirectional stress-state was attributed with the generation of off-axis fracture pattern within the coating as identified via post-experiment scanning electron microscopy. Thus, this study unveiled critical, coupled thermomechanical mechanisms governing the coating fracture of coated claddings at LWR temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

Although it is well known that cysteamine is a potent chemical for treating many diseases including cystinosis and it has many adverse effects, the effect of cysteamine on spermatogenesis is as yet unknown. Therefore the objective of this investigation was to explore the effects of cysteamine on spermatogenesis and the underlying mechanisms. Sheep were treated with vehicle control, 10 mg/kg or 20 mg/kg cysteamine for six months. After that, the semen samples were collected to determine the spermatozoa motility by computer-assisted sperm assay method. Blood samples were collected to detect the levels of hormones and the activity of enzymes. Spermatozoa and testis samples were collected to study the mechanism of cysteamine's actions. It was found that the effects of cysteamine on spermatogenesis were dose dependent. A low dose (10 mg/kg) cysteamine treatment increased ovine spermatozoa motility; however, a higher dose (20 mg/kg) decreased both spermatozoa concentration and motility. This decrease might be due to a reduction in steroid hormone production by the testis, a reduction in energy in the testis and spermatozoa, a disruption in the blood-testis barrier, or a breakdown in the vital signaling pathways involved in spermatogenesis. The inhibitory effects of cysteamine on sheep spermatogenesis may be used to model its effects on young male patients with cystinosis or other diseases that are treated with this drug. Further studies on spermatogenesis that focus on patients treated with cysteamine during the peripubertal stage are warranted. - Highlights: • Dose dependent effects of cysteamine on spermatogenesis • A low dose (10 mg/kg) increased spermatozoa motility. • A higher dose (20 mg/kg) decreased both concentration and motility of spermatozoa. • Disruption in the blood-testis barrier caused reduction in concentration and motility.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Host-linked soil viral ecology along a permafrost thaw gradient

Climate change threatens to release abundant carbon that is sequestered at high latitudes, but the constraints on microbial metabolisms that mediate the release of methane and carbon dioxide are poorly understood. The role of viruses, which are known to affect microbial dynamics, metabolism and biogeochemistry in the oceans, remains largely unexplored in soil. Here, we aimed to investigate how viruses influence microbial ecology and carbon metabolism in peatland soils along a permafrost thaw gradient in Sweden. We recovered 1,907 viral populations (genomes and large genome fragments) from 197 bulk soil and size-fractionated metagenomes, 58% of which were detected in metatranscriptomes and presumed to be active. In silico predictions linked 35% of the viruses to microbial host populations, highlighting likely viral predators of key carbon-cycling microorganisms, including methanogens and methanotrophs. Lineage-specific virus/host ratios varied, suggesting that viral infection dynamics may differentially impact microbial responses to a changing climate. Virus-encoded glycoside hydrolases, including an endomannanase with confirmed functional activity, indicated that viruses influence complex carbon degradation and that viral abundances were significant predictors of methane dynamics. In conclusion, these findings suggest that viruses may impact ecosystem function in climate-critical, terrestrial habitats and identify multiple potential viral contributions to soil carbon cycling.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Rotaxane probes for protease detection by 129 Xe hyperCEST NMR

In this work, we report a CB6 rotaxane for the 129 Xe hyperCEST NMR detection of matrix metalloprotease 2 (MMP-2) activity. MMP-2 is overexpressed in cancer tissue, and hence is a cancer marker. A peptide containing an MMP-2 recognition sequence was incorporated into the rotaxane, synthesized via CB6-promoted click chemistry. Upon cleavage of the rotaxane by MMP-2, CB6 became accessible for 129 Xe@CB6 interactions, leading to protease-responsive hyperCEST activation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

A Multi-Analysis Approach for Estimating Regional Health Impacts from the 2017 Northern California Wildfires

In the evening of October 8 and early hours of October 9, 2017, high winds in Northern California downed trees and power lines, igniting some of the most devastating wildfires the state had seen, and within hours unhealthy air quality impacted millions of people. We simulated these air quality conditions using fire detection information from the MODIS, VIIRS, and GOES-16 ABI satellite instruments, and applying a set of three WRF–CMAQ simulations, one data fusion, and three machine learning methods. We investigated using the 5-min available GOES-16 fire detection data to simulate timing of fire activity to allocate emissions hourly for the WRF-CMAQ air quality modeling system. Interestingly, this approach did not necessarily improve results compared to the baseline case, which used a default time profile. However, this approach was key to simulating the initial 12-hr explosive fire activity and smoke impacts. The WRF-CMAQ simulations compared well with observational data for the October 8-15 time period and tended to overestimate concentrations October 16-20. To improve these results, we applied three machine learning algorithms. We also had a unique opportunity to evaluate results with temporary monitors deployed specifically for wildfires, and performance was markedly different. For example, at the permanent monitoring locations, the WRF-CMAQ simulations had a Pearson correlation of 0.65, and the data fusion approach improved this (Pearson correlation = 0.95), while at the temporary monitor locations across the WRF-CMAQ, data fusion, and machine learning datasets, the best Pearson correlation was 0.5. The data fusion and machine learning results were biased low and WRF-CMAQ results were biased high. Finally, we applied the optimized PM2.5 exposure estimate in a short-term exposure-response function. Total estimated mortality attributable to PM2.5 exposure during the smoke episode was 83 (95% confidence interval: 0, 196) with 47% of these deaths attributable to wildland fire smoke.

O'Neill, Susan↗
DOE OSTI2011

EVIDENCE FOR ULTRA-FAST OUTFLOWS IN RADIO-QUIET ACTIVE GALACTIC NUCLEI. II. DETAILED PHOTOIONIZATION MODELING OF Fe K-SHELL ABSORPTION LINES

X-ray absorption line spectroscopy has recently shown evidence for previously unknown Ultra-fast Outflows (UFOs) in radio-quiet active galactic nuclei (AGNs). These have been detected essentially through blueshifted Fe XXV/XXVI K-shell transitions. In the previous paper of this series we defined UFOs as those highly ionized absorbers with an outflow velocity higher than 10,000 km s{sup -1} and assessed the statistical significance of the associated blueshifted absorption lines in a large sample of 42 local radio-quiet AGNs observed with XMM-Newton. The present paper is an extension of that work. First, we report a detailed curve of growth analysis of the main Fe XXV/XXVI transitions in photoionized plasmas. Then, we estimate an average spectral energy distribution for the sample sources and directly model the Fe K absorbers in the XMM-Newton spectra with the detailed Xstar photoionization code. We confirm that the frequency of sources in the radio-quiet sample showing UFOs is >35% and that the majority of the Fe K absorbers are indeed associated with UFOs. The outflow velocity distribution spans from {approx}10,000 km s{sup -1} ({approx}0.03c) up to {approx}100,000 km s{sup -1} ({approx}0.3c), with a peak and mean value of {approx}42,000 km s{sup -1} ({approx}0.14c). The ionization parameter is very high and in the range log {xi} {approx} 3-6 erg s{sup -1} cm, with a mean value of log {xi} {approx} 4.2 erg s{sup -1} cm. The associated column densities are also large, in the range N{sub H} {approx} 10{sup 22}-10{sup 24} cm{sup -2}, with a mean value of N{sub H} {approx} 10{sup 23} cm{sup -2}. We discuss and estimate how selection effects, such as those related to the limited instrumental sensitivity at energies above 7 keV, may hamper the detection of even higher velocities and higher ionization absorbers. We argue that, overall, these results point to the presence of extremely ionized and possibly almost Compton-thick outflowing material in the innermost regions of AGNs. This also suggests that UFOs may potentially play a significant role in the expected cosmological feedback from AGNs and their study can provide important clues on the connection between accretion disks, winds, and jets.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Stellar mass functions of galaxies at 4 < z < 7 from an IRAC-selected sample in COSMOS/UltraVISTA: Limits on the abundance of very massive galaxies

We build a Spitzer IRAC-complete catalog of objects complementing the K{sub s}-band selected UltraVISTA catalog with objects detected in IRAC only. To identify massive (log(M{sub ∗}/M{sub ⊙})>11) galaxies at 4 4 massive galaxies by 83%, implying a rapid growth of massive galaxies in the first 1.5 Gyr of cosmic history. The stellar-mass complete sample includes one candidate of a very massive (log(M{sub ∗}/M{sub ⊙})∼11.5), quiescent galaxy at z∼5.4 with MIPS 24 μm detection, suggesting the presence of an obscured active galactic nucleus. Finally, we show that the observed number of 4<z<7 massive galaxies matches the number of massive galaxies at 3<z<6 predicted by current galaxy formation models.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Electromagnetic energy calibration of the SoLid detector with horizontal muons

SoLid is a neutrino experiment at very-short baselinesearching for active-to-sterile oscillations of reactorantineutrinos. The detection principle is based on the pairing oftwo types of solid scintillators: polyvinyl toluene and $^{6}$Li:ZnS(Ag), which is a new technology used in this field ofPhysics. In addition to good neutron-gamma discrimination, thissetup allows the detector to be highly segmented; the basicdetection unit is a 5 cm cube. High segmentation provides numerousadvantages including precise localisation of the Inverse Beta Decay(IBD) products, the derivation of an antineutrino energy estimatorbased on the isolated positron energy, and a powerful backgroundreduction tool that relies on the topological signature of thesignal. Finally, the system is read out by a network ofwavelength-shifting fibres coupled to photosensors. A relativeelectromagnetic calibration is performed with horizontal cosmicmuons. This source poses the simplest calibration problem in which asingle detection unit is involved. In addition, large muon energydeposits allow us to perform a calibration at the most detailedlevel (i.e. per fibre) and to accurately define the fraction ofenergy escaping to neighbouring detection cells. A statisticalprecision at the sub-percent level is reached. The paper alsodiscusses two methods to calibrate the absolute energy scale andpresents their implementation and results. The first method relieson horizontal muons, though the precision is limited to around 10%because of the uncertainty in the energy distribution of suchmuons. A novel, alternative method based on the radioactiveamericium-beryllium source is proposed. It takes advantage of theelectron-positron pair-production process and provides a calibrationpoint at 3.4 MeV (i.e. in the core of the IBD positronspectrum). The paper is concluded with various cross-check includinga determination of the energy spectrum of the standard cosmogenicbackground candle: $^{12}$B.

Abreu, Y. [Antwerp U.]↗
DOE OSTI2017

Proton capture reaction cross section measurements on Er 162 as a probe of statistical model calculations

It is crucial to measure reaction cross sections relevant to the astrophysical γ process so that theoretical reaction rates can be tested and validated with experimental data. Here, the total cross sections for the 162 Er(p,γ) 163 Tm and the 162 Er(p,n) 162 Tm reactions have been measured by the activation method in center-of-mass energies from 3.973 to 8.944 MeV and from 5.962 to 8.944 MeV, respectively. The nucleus 162 Er is the heaviest p nuclide to be measured by the activation method using γ -ray spectroscopy, so far. It is important to note that the energy range for the (p,γ) reaction measurement covers a large fraction of the astrophysically relevant energy region between 2.71 and 5.34 MeV. The targets were prepared by evaporating 28.2 % isotopically enriched 162 Er 2 O 3 powder onto carbon backing foils, and bombarded with proton beams provided by the FN Tandem Accelerator at the University of Notre Dame. The reaction yields have been determined by the observed activity of produced radioactive isotopes, which was detected offline by a high-purity germanium detector. The results are presented and compared with calculations from two statistical model codes: NON-SMOKER and TALYS.

150 ≤ A ≤ 189↗
DOE OSTI2024

Data-driven background model for the CUORE experiment

Here, we present the model we developed to reconstruct the CUORE radioactive background based on the analysis of an experimental exposure of 1038.4 kg yr. The data reconstruction relies on a simultaneous Bayesian fit applied to energy spectra over a broad energy range. The high granularity of the CUORE detector, together with the large exposure and extended stable operations, allow for an in-depth exploration of both spatial and time dependence of backgrounds. We achieve high sensitivity to both bulk and surface activities of the materials of the setup, detecting levels as low as 10 nBq kg −1 and 0.1 nBq cm −2 , respectively. We compare the contamination levels we extract from the background model with prior radio-assay data, which informs future background risk mitigation strategies. The results of this background model play a crucial role in constructing the background budget for the CUPID experiment as it will exploit the same CUORE infrastructure.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Search for sterile neutrino mixing using three years of IceCube DeepCore data

Here, we introduce a search for a light sterile neutrino using three years of atmospheric neutrino data from the DeepCore detector in the energy range of approximately 10–60 GeV. DeepCore is the low-energy subarray of the IceCube Neutrino Observatory. The standard three-neutrino paradigm can be probed by adding an additional light (Δ$m^{2}_{41}$~1 eV 2 ) sterile neutrino. Sterile neutrinos do not interact through the standard weak interaction and, therefore, cannot be directly detected. Yet, their mixing with the three active neutrino states leaves an imprint on the standard atmospheric neutrino oscillations for energies below 100 GeV. A search for such mixing via muon neutrino disappearance is presented here. The data are found to be consistent with the standard three-neutrino hypothesis. Thus, we derive limits on the mixing matrix elements at the level of |U μ4 | 2 <0.11 and |U τ4 | 2 <0.15 (90% C.L.) for the sterile neutrino mass splitting Δ$m^{2}_{41}$=1.0 eV 2 .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

SU-C-204-05: Simulations of a Portal Imaging System for Conformal and Intensity Modulated Fast Neutron Therapy

Purpose: The University of Washington Medical Center offers neutron therapy for the palliative and definitive treatment of selected cancers. In vivo field verification has the potential to improve the safe and effective delivery of neutron therapy. We propose a portal imaging method that relies on the creation of positron emitting isotopes (11C and 15O) through (n, 2n) reactions with a PMMA plate placed below the patient. After field delivery, the plate is retrieved from the vault and imaged using a reader that detects annihilation photons. The spatial pattern of activity produced in the PMMA plate provides information to reconstruct the neutron fluence map needed to confirm treatment delivery. Methods: We used MCNP to simulate the accumulation of 11C activity in a slab of PMMA 2 mm thick, and GATE was used to simulate the sensitivity and spatial resolution of a prototype imaging system. BGO crystal thicknesses of 1 cm, 2 cm and 3 cm were simulated with detector separations of 2 cm. Crystal pitches of 2 mm and 4 mm were evaluated. Back-projection of the events was used to create a planar image. The spatial resolution was taken to be the FWHM of the reconstructed point source image. Results: The system sensitivity for a point source in the center of the field of view was found to range from 58% for 1 cm thick BGO with 2 mm crystal pitch to 74% for the 3 cm thick BGO crystals with 4 mm crystal pitch. The spatial resolution at the center of the field of view was found to be 1.5 mm for the system with 2 mm crystal pitch and 2.8 mm for the system with the 4 mm crystal pitch. Conclusion: BGO crystals with 4 mm crystal pitch and 3 cm length would offer the best sensitivity reader.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2013

Influence of metal impurities on recombination activity of dislocations in multicrystalline silicon

The influence of Fe, Cu, and Ni atoms introduced by means of high-temperature diffusion on the recombination properties of dislocations in multicrystalline silicon is investigated by the electron-beam induced-current (EBIC) method. It is shown that the influence of all three impurities is qualitatively similar. Recombination activity of dislocations remains lower than the detection limit in the EBIC mode both for starting samples and after the diffusion of transition metals. The behavior of dislocations is interpreted under the assumption that dislocations are already impurity-saturated in starting samples.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Elucidating Cathode Degradation Mechanisms in LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811)/Graphite Cells Under Fast Charge Rates Using Operando Synchrotron Characterization

Li-ion batteries capable of extreme fast charging (XFC) are in demand to facilitate widespread electric vehicle (EV) adoption. While the impact of fast charge on the negative electrode has been studied, degradation of state-of-the-art NMC811 under XFC conditions has not been studied in detail. Herein, cathode degradation is probed in NMC811/graphite batteries by analysis of structural and chemical changes for recovered samples previously cycled under XFC conditions and during typical cycling. NMC surface reconstruction, as determined by soft X-ray absorption, was not detected for recovered electrodes. Furthermore, bulk redox activity from X-ray absorption near edge structure measurements showed more change in the oxidation state of Ni and Co under the 1C charge rate compared to the 4C rate consistent with the electrochemistry. Increased unit cell volume contraction under the 1C rate as determined by operando X-ray diffraction suggests that higher charge rates may provide a protective effect on the cathode by reducing structural distortion due to less delithiation.

25 ENERGY STORAGE↗
DOE OSTI2011

SALTSTONE VAULT CLASSIFICATION SAMPLES MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT/ACTINIDE REMOVAL PROCESS WASTE STREAM APRIL 2011

Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained by SRNL on April 5, 2011 (Tank 50H sampling occurred on April 4, 2011) during 2QCY11 to determine the non-hazardous nature of the grout and for additional vault classification analyses. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. Additional inorganic species determined by B&W TSG-RACL include aluminum, boron, chloride, cobalt, copper, fluoride, iron, lithium, manganese, molybdenum, nitrate/nitrite as Nitrogen, strontium, sulfate, uranium, and zinc and the following radionuclides: gross alpha, gross beta/gamma, 3H, 60Co, 90Sr, 99Tc, 106Ru, 106Rh, 125Sb, 137Cs, 137mBa, 154Eu, 238Pu, 239/240Pu, 241Pu, 241Am, 242Cm, and 243/244Cm. B&W TSG-RACL provided subsamples to GEL Laboratories, LLC for analysis for the VOCs benzene, toluene, and 1-butanol. GEL also determines phenol (total) and the following radionuclides: 147Pm, 226Ra and 228Ra. Preparation of the 2QCY11 saltstone samples for the quarterly analysis and for vault classification purposes and the subsequent TCLP analyses of these samples showed that: (1) The saltstone waste form disposed of in the Saltstone Disposal Facility in 2QCY11 was not characteristically hazardous for toxicity. (2) The concentrations of the eight RCRA metals and UHCs identified as possible in the saltstone waste form were present at levels below the UTS. (3) Most of the inorganic species measured in the leachate do not exceed the MCL, SMCL or TW limits. (4) The inorganic waste species that exceeded the MCL by more than a factor of 10 were nitrate, nitrite and the sum of nitrate and nitrite. (5) Analyses met all quality assurance specifications of US EPA SW-846. (6) The organic species (benzene, toluene, 1-butanol, phenol) were either not detected or were less than reportable for the vault classification samples. (7) The gross alpha and radium isotopes could not be determined to the MCL because of the elevated background which raised the detection limits. (8) Most of the beta/gamma activity was from 137Cs and its daughter 137mBa. (9) The concentration of 137Cs and 90Sr were present in the leachate at concentrations 1/40th and 1/8th respectively than in the 2003 vault classification samples. The saltstone waste form placed in the Saltstone Disposal Facility in 2QCY11 met the SCHWMR R.61-79.261.24(b) RCRA metals requirements for a nonhazardous waste form. The TCLP leachate concentrations for nitrate, nitrite and the sum of nitrate and nitrite were greater than 10x the MCLs in SCDHEC Regulations R.61-107.19, Part I A, which confirms the Saltstone Disposal Facility classification as a Class 3 Landfill. The saltstone waste form placed in the Saltstone Disposal Facility in 2QCY11 met the R.61-79.268.48(a) non wastewater treatment standards.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗