Results for “Collection 7” — Page 5

DOE OSTI2024

Experimental Observation of a New Attenuation Mechanism in hcp ‐Metals That May Operate in the Earth's Inner Core

Abstract Seismic observations show the Earth's inner core has significant and unexplained variation in seismic attenuation with position, depth and direction. Interpreting these observations is difficult without knowledge of the visco‐ or anelastic dissipation processes active in iron under inner core conditions. Here, a previously unconsidered attenuation mechanism is observed in zinc, a low pressure analog ofhcp‐iron, during small strain sinusoidal deformation experiments. The experiments were performed in a deformation‐DIA combined with X‐radiography, at seismic frequencies (∼0.003–0.1 Hz), high pressure and temperatures up to ∼80% of melting temperature. Significant dissipation (0.077 ≤ Q −1 (ω) ≤ 0.488) is observed along with frequency dependent softening of zinc's Young's modulus and an extremely small activation energy for creep (⩽7 kJ mol −1 ). In addition, during sinusoidal deformation the original microstructure is replaced by one with a reduced dislocation density and small, uniform, grain size. This combination of behavior collectively reflects a mode of deformation called “internal stress superplasticity”; this deformation mechanism is unique to anisotropic materials and activated by cyclic loading generating large internal stresses. Here we observe a new form of internal stress superplasticity, which we name as “elastic strain mismatch superplasticity.” In it the large stresses are caused by the compressional anisotropy. If this mechanism is also active inhcp‐iron and the Earth's inner‐core it will be a contributor to inner‐core observed seismic attenuation and constrain the maximum inner‐core grain‐size to ≲10 km.

Geochemistry & Geophysics↗

DOE OSTI2026

Ionization and temperature measurements in warm dense copper using x-ray absorption spectroscopy

We detail experimental results inferring ionization and temperature for warm dense copper plasmas at several times solid density (15–25 g/cm 3 ) and temperatures of 10–21 eV. Experiments performed at the OMEGA Laser Facility generate uniform warm dense matter conditions via symmetric shock compression of a buried copper layer. The plasma is probed with a laser-generated x-ray source to collect the K-shell x-ray absorption spectrum. Fitting bound-bound absorption contributions from constituent charge states of copper provides an estimated $\overline{Z}$ of approximately 4–7 for these warm dense copper plasmas. We find that these partially ionized plasmas have K-edge shifts of 12–30 eV and bound-bound resonance 1s → 3p absorption shifts of 4–26 eV with respect to the cold K edge. This study provides necessary experimental data to improve ionization and opacity models in the warm dense matter regime.

42 ENGINEERING↗

DOE OSTI2024

Distinct vibrational motions promote disparate excited-state decay pathways in cofacial perylenediimide dimers

A complex interplay of structural, electronic, and vibrational degrees of freedom underpins the fate of molecular excited states. Organic assemblies exhibit a myriad of excited-state decay processes, such as symmetry-breaking charge separation (SB-CS), excimer (EX) formation, singlet fission, and energy transfer. Recent studies of cofacial and slip-stacked perylene-3,4:9,10-bis(dicarboximide) (PDI) multimers demonstrate that slight variations in core substituents and H- or J-type aggregation can determine whether the system follows an SB-CS pathway or an EX one. However, questions regarding the relative importance of structural properties and molecular vibrations in driving the excited-state dynamics remain. Here, we use a combination of two-dimensional electronic spectroscopy, femtosecond stimulated Raman spectroscopy, and quantum chemistry computations to compare the photophysics of two PDI dimers. The dimer with 1,7-bis(pyrrolidin-1′-yl) substituents (5PDI2) undergoes ultrafast SB-CS from a photoexcited mixed state, while the dimer with bis-1,7-(3′,5′-di-t-butylphenoxy) substituents (PPDI2) rapidly forms an EX state. Examination of their quantum beating features reveals that SB-CS in 5PDI2 is driven by the collective vibronic coupling of two or more excited-state vibrations. In contrast, we observe signatures of low-frequency vibrational coherence transfer during EX formation by PPDI2, which aligns with several previous studies. We conclude that key electronic and structural differences between 5PDI2 and PPDI2 determine their markedly different photophysics.

Chemistry↗

DOE OSTI2024

Road to PROSPECT-II

The Precision Reactor Oscillation and SPECTrum (PROSPECT) experiment is based in a segmented liquid scintillator antineutrino detector situated approximately 7 meters from the highly enriched High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Its main goal is to investigate short-baseline antineutrino oscillations. The first phase of data collection, known as PROSPECT-I, was held from 2018 to 2019 and was used for several high-precision analyses, including multiple measurements of the $^{235}U$ antineutrino spectrum and searches for $eV$-scale sterile antineutrino oscillations. The collaboration is now preparing for the second phase, PROSPECT-II, which features an upgraded detector design. This advancement will enhance sensitivity and statistical power, allowing for a broader range of analyses beyond those achieved in PROSPECT-I. As we transition into this new phase, new questions have arisen concerning background simulation and its potential differences from those conducted during the initial phase of the experiment. Moreover, it is essential to ascertain, through simulations, the positive effects that an improved detector could have on the study of oscillations. This information is crucial for justifying the proposed enhancements, and I will cover all of this in the talk.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2025

Source Attribution of Methane Enhancements at the Southern Great Plains Atmospheric Radiation Measurement Site Field Campaign Report

Tower data from 2017 to 2020 revealed that the U.S. Department of Energy’s Southern Great Plains (SGP) Atmospheric Radiation Measurements (ARM) observatory in Oklahoma exhibited significant CH 4 enhancements compared to other U.S. tower sites. On average, near-surface CH 4 at the ARM site was higher, had larger diurnal and seasonal variations, and had sharper near-surface increases at night compared to other tower sites in the U.S. A field campaign was conducted in June 2024 to identify and quantify the surrounding CH 4 emission sources by two researchers from the University of Oklahoma. During the campaign, a mobile measurement was conducted using a LI-COR 7810 tracer gas analyzer mounted on a vehicle during June 23-26, 2024 near the SGP site (within 7 km distance). We sampled CH 4 along predefined routes surrounding a suspected source, i.e., a large animal feeding operation (AFO) farm 5.8 km northwest of the SGP ARM site. Measurements were collected between 04:30 and 09:00 local time when the planetary boundary layer (PBL) was shallow, increasing sensitivity to surface emissions. Driving speed was kept below 5 mph to minimize pressure-related artifacts. CH 4 concentrations downwind of the AFO exceeded 6000 ppb on the early morning of June 26, corresponding to an emission rate of ~95 kg⋅hr -1 estimated using the mass balance method. Additional sources identified during the campaign include nearby open-range cattle and leaks from a nearby natural gas pipeline.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

Road to PROSPECT-II

The Precision Reactor Oscillation and SPECTrum (PROSPECT) experiment is based in a segmented liquid scintillator antineutrino detector situated approximately 7 meters from the highly enriched High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Its main goal is to investigate short-baseline antineutrino oscillations. The first phase of data collection, known as PROSPECT-I, was held from 2018 to 2019 and was used for several high-precision analyses, including multiple measurements of the $^{235}U$ antineutrino spectrum and searches for $eV$-scale sterile antineutrino oscillations. The collaboration is now preparing for the second phase, PROSPECT-II, which features an upgraded detector design. This advancement will enhance sensitivity and statistical power, allowing for a broader range of analyses beyond those achieved in PROSPECT-I. As we transition into this new phase, new questions have arisen concerning background simulation and its potential differences from those conducted during the initial phase of the experiment. Moreover, it is essential to ascertain, through simulations, the positive effects that an improved detector could have on the study of oscillations. This information is crucial for justifying the proposed enhancements, and I will cover all of this in the talk.

43 PARTICLE ACCELERATORS↗

DOE OSTI2025

Test of lepton flavor universality in semileptonic 𝐵$^+_𝑐$ meson decays in proton-proton collisions at $\sqrt{𝑠}$ = 13 TeV

A measurement of the ratio of branching fractions 𝑅⁢(𝐽/𝜓) =ℬ⁡(𝐵$^+_𝑐$ →𝐽/𝜓⁢𝜏 + ⁢𝜈 𝜏 )/ℬ⁡(𝐵$^+_𝑐$ →𝐽/𝜓⁢𝜇 + ⁢𝜈 𝜇 ) in the 𝐽/𝜓 →𝜇 + ⁢𝜇 − , 𝜏 + →𝜇 + ⁢𝜈 𝜇 ⁢$\bar{𝜈}$ 𝜏 decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment in 2018, corresponding to an integrated luminosity of 59.7 fb −1 . The measured ratio, 𝑅⁢(𝐽/𝜓) = 0.1⁢7$^{+0.18}_{−0.17}⁢$(stat)$^{+0.21}_{−0.22⁢}$(syst)$^{+0.19}_{−0.18}$⁢(theo) =0.17 ± 0.33, agrees with the value of 0.2582 ± 0.0038 predicted by the standard model, which assumes lepton flavor universality. By testing lepton flavor universality, this measurement is a probe of new physics using 𝐵$^+_𝑐$ mesons, which are currently only produced at the LHC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2025

NLR HPC Kestrel Jobs Data

Overview: Anonymized job-level records from the Kestrel HPC system at the National Laboratory of the Rockies (NLR). Each record represents a Slurm batch job with scheduling metadata, resource requests, utilization, energy estimates, and efficiency metrics. Sensitive fields (user, account, job name, submit line, working directory, submit script, and job type) are replaced with 7-character cryptographic hashes. System & Timeframe: Kestrel is located at the NLR campus. Standard compute nodes have 104 cores and 256 GB RAM; bigmem nodes have 2,000 GB. GPU nodes (gpu-h100 partition) use NVIDIA H100 GPUs. Data covers jobs submitted August 2023 through December 2025. Funding provided by the U.S. Department of Energy, EERE. Files: esif.hpc.kestrel.job-anon.zip — Anonymized job records (Hive-partitioned Parquet) datacard.md — Full dataset documentation ~11 million rows, 50 variables. Readable with PyArrow, pandas, DuckDB, Apache Spark, or any Parquet-compatible tool. Data Collection: Jobs collected via sacct with timezone-aware export (SLURM_TIME_FORMAT="%Y-%m-%dT%H:%M:%S%z"), loaded into PostgreSQL. Calculated columns updated via database triggers and batch functions. All timestamps use timestamptz and correctly handle DST transitions. Preprocessing: Anonymization of name, user, account, submit_line, work_dir, submit_script, and job_type via 7-char hex hashes Derived columns: queue_wait, cpu_eff, max/min/avg_mem_eff, energy estimates Simplified job state mapping (e.g., "CANCELLED by 132357" → "CANCELLED") Boolean flags: python_job, reframe_job Temporal decomposition: year, month, day, day_of_week, hour, minute from submit_time Shared node tracking: shared_job_count, nodes_shared, jobs_shared Key Variables: Scheduling: job_id, partition, state_simple, submit_time, start_time, end_time, queue_wait Resources: nodes_req/used, processors_req/used, memory_req, wallclock_req/used, gpus_requested Efficiency: cpu_eff, max/min/avg_mem_eff Energy: cpu_energy_tdp_estimated_max/used_watt_hours, consumed_energy_raw_joules, consumed_energy_raw_watt_hours Sharing: shared_job_count, nodes_shared, jobs_shared Partitions: short, standard, debug, gpu-h100 Job States: CANCELLED, COMPLETED, FAILED, PENDING, RUNNING QoS Levels: normal, high Important Notes: Timestamps include timezone offsets; DST transitions are handled correctly, though adding intervals across DST boundaries requires offset adjustment shared_job_count reflects physical node co-residency, not use of the shared partition Job step records and raw Slurm JSONB fields are excluded Do not attempt to re-identify individuals from hashed fields

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2024

Virus ecology and 7‐year temporal dynamics across a permafrost thaw gradient

Abstract Soil microorganisms are pivotal in the global carbon cycle, but the viruses that affect them and their impact on ecosystems are less understood. In this study, we explored the diversity, dynamics, and ecology of soil viruses through 379 metagenomes collected annually from 2010 to 2017. These samples spanned the seasonally thawed active layer of a permafrost thaw gradient, which included palsa, bog, and fen habitats. We identified 5051 virus operational taxonomic units (vOTUs), doubling the known viruses for this site. These vOTUs were largely ephemeral within habitats, suggesting a turnover at the vOTU level from year to year. While the diversity varied by thaw stage and depth‐related patterns were specific to each habitat, the virus communities did not significantly change over time. The abundance ratios of virus to host at the phylum level did not show consistent trends across the thaw gradient, depth, or time. To assess potential ecosystem impacts, we predicted hosts in silico and found viruses linked to microbial lineages involved in the carbon cycle, such as methanotrophy and methanogenesis. This included the identification of viruses of Candidatus Methanoflorens, a significant global methane contributor. We also detected a variety of potential auxiliary metabolic genes, including 24 carbon‐degrading glycoside hydrolases, six of which are uniquely terrestrial. In conclusion, these long‐term observations enhance our understanding of soil viruses in the context of climate‐relevant processes and provide opportunities to explore their role in terrestrial carbon cycling.

Microbiology↗

DOE OSTI2026

Ionization-based search for magnetic monopoles using the NOvA Far Detector

We report a search for highly ionizing magnetic monopoles in the cosmic-ray flux using a 2713-day dataset collected during 2015–2025 with the NOvA Far Detector, a 14-kt segmented detector located on Earth’s surface in Minnesota, United States. The search is sensitive to monopoles across a wide range of speeds, 7 × 10 −4 < 𝛽 < 0.995, and is sensitive to masses as low as 2 × 10 5 GeV for the fastest monopoles. No signal was observed. With the detector’s large surface area and minimal overburden, we achieve the strongest flux limits reported to date in several regions of speed and mass. For heavy monopoles with masses above 10 13 GeV that are able to reach the detector from above or—crossing Earth—from below, we find a flux limit 𝜙 90% < 2 × 10 −16 cm −2 s −1 sr −1 (90% confidence level) for monopoles with 0.005 < 𝛽 < 0.8. Across the same range of speeds, we report a limit 𝜙 90% < 8 × 10 −16 cm −2 s −1 sr −1 for light monopoles with masses above 10 8 GeV that can reach the detector from above.

magnetic monopoles↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

2003 Interstate 595 Vehicle Trip-Length Study

# 2003 Interstate 595 Vehicle Trip-Length Study The 2003 Vehicle Trip-Length Study focused on Interstate 595 between Davie Road and University Drive in Florida. Survey participants answered questions about their trip's origin and destination—including the type of location such as work, home, store, etc.—the on- and off-ramps used, how many people were in the car, and the type of vehicle. The survey also collected household demographic data such as annual household income, available vehicles, the number of people living in their household, and the number of workers in their household above the age of 16. It also asked if they would use proposed bus-only lanes or train service along the corridor, if available. ## Data Collection Agency The survey was conducted by and for the Florida Department of Transportation. ## Survey Methodology The survey was conducted via mail and online in March 2003. ## Survey Records, Data, and Documentation Survey records include 7,917 participants. Origin and destination locations include street addresses, nearest intersections or landmarks, city, state, zip code, and latitude/longitude.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗