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132 records · Page 8

All sources NASA NTRS DOE OSTI

DOE OSTI2022

Influence of Polar Mutations on the Electronic and Structural Properties of Q A –· in Bacterial Reaction Centers

Reaction centers from Rb. sphaeroides with residue M265 mutated from isoleucine to threonine, serine, and asparagine (M265IT, M265IS, and M265IN, respectively) in the Q A –· state are studied by high-resolution ESEEM and ENDOR spectroscopies to investigate the structural characteristics of these mutants influencing the redox properties of the Q A site. All three mutants decrease the redox midpoint potential (E m ) of Q A by ~0.1 V, yet the mechanism for this drop in E m is unclear. In this work, we examine (i) the hydrogen bonding interactions between Q A –· and residues histidine M219 and alanine M260, (ii) the electron spin density distribution of the semiquinone, and (iii) the orientations of the ubiquinone methoxy substituents. 13 C measurements show no significant contribution of methoxy dihedral angles to the observed decrease in E m for the Q A mutants. Instead, 14 N three-pulse ESEEM data suggest electrostatic or hydrogen bond formation between the mutated M265 side chain and His-M219 N δ may be involved in the observed lowering of the Q A midpoint potential. For mutant M265IN, analysis of the proton hyperfine couplings reveals a weakened hydrogen bond network, resulting in an altered Q A –· spin density distribution. Here, the magnetic resonance study presented here is therefore most consistent with an electrostatic or structural perturbation of the His-M219 N δ hydrogen bond in these mutants as a mechanism for the ~0.1 V decrease in Q A E m .

14 SOLAR ENERGY↗

DOE OSTI2024

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2023

The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2023. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2023 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.

Record of Decision↗

DOE OSTI2025

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2024

The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2024. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2024 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2026

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2025

The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2025. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of the DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, the evaluation of data collected in 2025 continued to indicate that WVDP activities posed no threat to public health or safety, or to the environment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2023

Posiform planting: generating QUBO instances for benchmarking

We are interested in benchmarking both quantum annealing and classical algorithms for minimizing quadratic unconstrained binary optimization (QUBO) problems. Such problems are NP-hard in general, implying that the exact minima of randomly generated instances are hard to find and thus typically unknown. While brute forcing smaller instances is possible, such instances are typically not interesting due to being too easy for both quantum and classical algorithms. In this contribution, we propose a novel method, called posiform planting , for generating random QUBO instances of arbitrary size with known optimal solutions, and use those instances to benchmark the sampling quality of four D-Wave quantum annealers utilizing different interconnection structures (Chimera, Pegasus, and Zephyr hardware graphs) and the simulated annealing algorithm. Posiform planting differs from many existing methods in two key ways. It ensures the uniqueness of the planted optimal solution, thus avoiding groundstate degeneracy, and it enables the generation of QUBOs that are tailored to a given hardware connectivity structure, provided that the connectivity is not too sparse. Posiform planted QUBOs are a type of 2-SAT boolean satisfiability combinatorial optimization problems. Our experiments demonstrate the capability of the D-Wave quantum annealers to sample the optimal planted solution of combinatorial optimization problems with up to 5, 627 qubits.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2020

NDMAS System and Process Description

The U. S. Department of Energy (DOE) has made a significant investment in research to develop the next generation of reactor technologies as well as to improve the performance and lengthen the life cycle of existing nuclear reactors. Data collected to demonstrate new concepts may also be used in the future to support licensing of these technologies. Provenance of these data must be preserved. The Nuclear Data Management and Analysis System (NDMAS) was established to manage and preserve data collected by fuels and materials research conducted by the high-temperature, gas-cooled reactor program. The scope of NDMAS is expanding to include other nuclear research programs that have the shared need to preserve the provenance of research data. Nuclear research funded by DOE is conducted by Idaho National Laboratory (INL), universities, other national laboratories, foreign research partners, and private companies. This research will generate a large amount of data from a variety of sources over a period of many years. Managing the data generated by the research and development projects presents a significant challenge for retaining data integrity and availability.

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