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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Preparation of Potassium Acyltrifluoroborates (KATs) from Carboxylic Acids by Copper-Catalyzed Borylation of Mixed Anhydrides**

Here we report the preparation of potassium acyltrifluoroborates (KATs) from widely available carboxylic acids. Mixed anhydrides of carboxylic acids were prepared using isobutyl chloroformate and transformed to the corresponding KATs using a commercial copper catalyst, B 2 (pin) 2 , and aqueous KHF 2 . This method allows for the facile preparation of aliphatic, aromatic, and amino acid-derived KATs and is compatible with a variety of functional groups including alkenes, esters, halides, nitriles, and protected amines.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

PtCo/MWCNTs Prepared by a Microwave‐assisted Polyol Method for Selective Cinnamaldehyde Hydrogenation

Abstract Using microwave irradiation, PtCo alloy nanoparticles were deposited within a few minutes on COOH‐functionalized MWCNT supports. The obtained catalysts were used for selective hydrogenation of cinnamaldehyde, a reaction whose products are widely used in various fields. In the selective cinnamaldehyde hydrogenation to cinnamyl alcohol, microwave‐prepared catalysts (generically, Pt x Co y ‐MW) outperformed a catalyst prepared by the conventional method (Pt 1 Co 2 ‐con). The highest selective hydrogenation to cinnamyl alcohol, 89%, was obtained using Pt 1 Co 2 ‐MW, while Pt 1 Co 2 ‐con showed a selectivity of 76%. Characterization results confirmed that the microwave prepared samples had a stronger interaction between Pt and Co than that in the Pt 1 Co 2 ‐con sample. The alloyed Co altered the electronic structure of Pt, leading to favorable adsorption of the C=O bond by the lone‐pair electrons of its oxygen atom. Moreover, the Pt 1 Co 2 ‐MW sample showed neglectable change in catalytic performance (e. g., cinnamaldehyde conversion and selective hydrogenation to cinnamyl alcohol) during recycling experiments.

Wang, Kaiying↗
DOE OSTI2024

Robust surfactant-assisted one-pot sample preparation for label-free single-cell and nanoscale proteomics

With advanced mass spectrometry (MS)-based proteomics, genome-scale proteome coverage can be achieved from bulk cells. However, such bulk measurement obscures cell to cell heterogeneity, precluding proteome profiling of single cells and small numbers of cells of interest. To address this issue, in recent 5 years there are a surge of small sample preparation methods developed for robust effective collection and processing of single cells and small numbers of cells for in-depth MS-based proteome profiling. Based on their broad accessibility, they can be categorized into two types: specific device- and standard PCR tube- or multi-well plate-based methods. Herein we describe the detailed protocol of our recently developed, easily adoptable, Surfactant-assisted One-Pot (SOP) sample preparation coupled with MS method termed SOP-MS for label-free single-cell and nanoscale proteomics. SOP-MS capitalizes on the combination of a MS-compatible surfactant, DDM (n-Dodecyl-ß-D-maltoside), and standard low-bind PCR tube or multi-well plate for ‘all-in-one’ one-pot sample preparation without sample transfer. With its robust and convenient features, SOP-MS can be readily implemented in any MS laboratory for single-cell and nanoscale proteomics. With further improvements in MS detection sensitivity and sample throughput, we believe that SOP-MS could open an avenue for single-cell proteomics with broad applicability in the biological and biomedical research.

Single-cell proteomics, nanoscale proteomics, SOP-↗
DOE OSTI2022

Preparation of Actinide Targets at Oregon State University

In this paper, we describe the preparation of actinide targets at Oregon State University. The preparation of the actinide fluorides is done by an aqueous precipitation procedure with yields of greater than 90%. A dual glove box system is used for the preparation of the fluorides of the high specific activity actinides and the subsequent vapor deposition. We compare and contrast targets made by vapor deposition and molecular plating. We discuss some new data on the structure of actinide targets.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Apollo Next Generation Sample Analysis (ANGSA): an Apollo Participating Scientist Program to Prepare the Lunar Sample Community for Artemis

As a first step in preparing for the return of samples from the Moon by the Artemis Program, NASA initiated the Apollo Next Generation Sample Analysis Program (ANGSA). ANGSA was designed to function as a low-cost sample return mission and involved the curation and analysis of samples previously returned by the Apollo 17 mission that remained unopened or stored under unique conditions for 50 years. These samples include the lower portion of a double drive tube previously sealed on the lunar surface, the upper portion of that drive tube that had remained unopened, and a variety of Apollo 17 samples that had remained stored at -27 °C for approximately 50 years. ANGSA constitutes the first preliminary examination phase of a lunar “sample return mission” in over 50 years. It also mimics that same phase of an Artemis surface exploration mission, its design included placing samples within the context of local and regional geology through new orbital observations collected since Apollo and additional new “boots-on-the-ground” observations, data synthesis, and interpretations provided by Apollo 17 astronaut Harrison Schmitt. ANGSA used new curation techniques to prepare, document, and allocate these new lunar samples, developed new tools to open and extract gases from their containers, and applied new analytical instrumentation previously unavailable during the Apollo Program to reveal new information about these samples. Most of the 90 scientists, engineers, and curators involved in this mission were not alive during the Apollo Program, and it had been 30 years since the last Apollo core sample was processed in the Apollo curation facility at NASA JSC. There are many firsts associated with ANGSA that have direct relevance to Artemis. ANGSA is the first to open a core sample previously sealed on the surface of the Moon, the first to extract and analyze lunar gases collected in situ, the first to examine a core that penetrated a lunar landslide deposit, and the first to process pristine Apollo samples in a glovebox at -20 °C. All the ANGSA activities have helped to prepare the Artemis generation for what is to come. The timing of this program, the composition of the team, and the preservation of unopened Apollo samples facilitated this generational handoff from Apollo to Artemis that sets up Artemis and the lunar sample science community for additional successes.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Neutron capture of UO 2 targets prepared by spin-coating assisted combustion synthesis

Two uranium dioxide (UO 2 ) targets of (414 ± 23) nm and (1092 ± 93) nm thicknesses were prepared on 6061 aluminum alloy and puratronic grade aluminum backing materials. The targets were deposited with a novel method combining spin coating and solution combustion synthesis (SCS). The target layers consisted of small (3–7 nm) UO 2 grains and uniformly distributed ultra-small (1–3 nm) pores. The prepared targets were tested at the Los Alamos National Laboratory’s LANSCE facility for neutron irradiation damage and suitability for neutron capture experiments. The samples showed no signs of target material loss after the irradiation. However, irradiation caused a significant increase in the grain size (4–10 nm), as well as upward mass diffusion and coalescence of the pores due to the thermal spikes. The magnesium in the aluminum 6061 alloy backing also diffused into the UO 2 layer during neutron irradiation. The structural changes in the target after the irradiation do not affect the data from neutron capture. As a result, the new method can be used more broadly to prepare other actinide targets for nuclear physics experiments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Preparation, characterization, and structural studies of new ruthenium(II) and ruthenium(III) complexes incorporating pyrazole ligands

Multimetallic complexes containing disparate metals have been established to have practical utilities. We previously reported a strategy for preparing such species by using combinations of neutral pyrazole (Hpyz, C 3 N 2 H 4 ) and anionic pyrazolyl ligands (pyz, C 3 N 2 H 3 – ), and herein are reported several new complexes that should be capable of incorporating a second metal center. Two of the complexes, [Ru(1,5-cod)(Hpyz) 3 Cl][BPh 4 ] and Ru(1,5-cod)(Hpyz) 2 (pyz) 2 (cod = cyclooctadiene), were prepared from [Ru(cod)Cl 2 ] 2 , while [Ru(tmeda)(Hpyz) 2 Cl 2 ][BF 4 ] (tmeda = tetramethylethylenediamine) was prepared from the neutral Ru(II) complex Ru(tmeda)(Hpyz) 2 Cl 2 via one electron oxidation by the ferricinium ion. The first two complexes, one cationic and the other uncharged, involve Ru(II), while the tmeda complex involves Ru(III). Finally, all three species have been structurally characterized.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Site-specific plan-view (S)TEM sample preparation from thin films using a dual-beam FIB-SEM

To fully evaluate the atomic structure, and associated properties of materials using transmission electron microscopy, examination of samples from three non-collinear orientations is needed. This is particularly challenging for thin films and nanoscale devices built on substrates due to limitations with plan-view sample preparation. In this work, a new method for preparation of high-quality, site-specific, plan-view TEM samples from thin-films grown on substrates, is presented and discussed. Here, it is based on using a dual-beam focused ion beam scanning electron microscope (FIB-SEM) system. To demonstrate the method, the samples were prepared from thin films of perovskite oxide BaSnO 3 grown on a SrTiO 3 substrate and metal oxide IrO 2 on a TiO 2 substrate, ranging from 20–80 nm in thicknesses using molecular beam epitaxy. While the method is optimized for the thin films, it can be extended to other site-specific plan-view samples and devices build on wafers. Aberration-corrected STEM was used to evaluate the quality of the samples and their applicability for atomic-resolution imaging and analysis.

BaSnO3↗
DOE OSTI2025

A Reduced-Temperature Process for Preparing Atomically Clean Si(100) and SiGe(100) Surfaces with Vapor HF

Silicon processing techniques such as atomic precision advanced manufacturing (APAM) and epitaxial growth require surface preparations that activate oxide desorption (typically >1000 °C) and promote surface reconstruction toward atomically clean, flat, and ordered Si(100)-2 × 1. Here, in this study, we compare the aqueous and vapor phase cleaning of Si and Si/SiGe surfaces to prepare APAM-ready and epitaxy-ready surfaces at lower temperatures. Angle resolved X-ray photoelectron spectroscopy (ARXPS) and Fourier transform infrared (FTIR) spectroscopy indicate that vapor hydrogen fluoride (VHF) cleans dramatically reduce carbon surface contamination and allow the chemically prepared surface to reconstruct at lower temperatures, 600 °C for Si and 580 °C for a Si/Si 0.7 Ge 0.3 heterostructure, into an ordered atomic terrace structure indicated by scanning tunneling microscopy (STM). After thermal treatment and vacuum hydrogen termination, we demonstrate STM hydrogen desorption lithography (HDL) on VHF-treated Si samples, creating reactive zones that enable area-selective chemistry by using a thermal budget similar to CMOS process flows. We anticipate that these results will establish new pathways to integrate APAM with Si foundry processing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Reaction of Hydrazine with Solution- and Vacuum-Prepared Selectively Terminated Si(100) Surfaces: Pathways to the Formation of Direct Si–N Bonds

Here, the reactivity of liquid hydrazine (N 2 H 4 ) with respect to H-, Cl-, and Br-terminated Si(100) surfaces was investigated to uncover the principles of nitrogen incorporation into the interface. This process has important implications in a wide variety of applications, including semiconductor surface passivation and functionalization, nitride growth, and many others. The use of hydrazine as a precursor allows for reactions that exclude carbon and oxygen, the primary sources of contamination in processing. In this work, the reactivity of N 2 H 4 with H- and Cl-terminated surfaces prepared by traditional solvent-based methods and with a Br-terminated Si(100) prepared in ultrahigh vacuum was compared. The reactions were studied with X-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy, and the observations were supported by computational investigations. The H-terminated surface led to the highest level of nitrogen incorporation; however, the process proceeds with increasing surface roughness, suggesting possible etching or replacement reactions. In the case of Cl-terminated (predominantly dichloride) and Br-terminated (monobromide) surfaces, the amount of nitrogen incorporation on both surfaces after the reaction with hydrazine was very similar despite the differences in preparation, initial structure, and chemical composition. Density functional theory was used to propose the possible surface structures and to analyze surface reactivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Rapid Postgrafting Reaction to Prepare Quaternized Polycarbazoles

We report a rapid postgrafting reaction to prepare alkyl ammonium functionalized polycarbazoles from a commercially available monomer. This novel synthetic approach provides benefit to preparing the high molecular weight quaternized polycarbazoles within 1 h of Friedel–Crafts polycondensation, avoiding the synthesis and purification step to prepare a functionalized monomer. The postgrafting reaction produces hexyl alkyl ammonium functionalized polycarbazole with 100% grafting degree. However, the postgrafting reaction produced only 60% grafting with propyl alkyl ammonium due to the competitive elimination reaction because of the higher acidity of β-hydrogen in the propyl alkyl group resulting from the proximity of the bromide and ammonium groups. The hexyl alkyl ammonium functionalized polycarbazole has a high hydroxide conductivity of 103 mS cm –1 at 80 °C and showed excellent alkaline stability with less than 3% loss of ion group after 1 M NaOH treatment at 80 °C for 500 h. In conclusion, this study highlights that the postgrafting reaction provides a pathway for the scale-up synthesis of quaternized aryl ether-free polyaromatics.

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

Gate-free state preparation for fast variational quantum eigensolver simulations

Abstract The variational quantum eigensolver is currently the flagship algorithm for solving electronic structure problems on near-term quantum computers. The algorithm involves implementing a sequence of parameterized gates on quantum hardware to generate a target quantum state, and then measuring the molecular energy. Due to finite coherence times and gate errors, the number of gates that can be implemented remains limited. In this work, we propose an alternative algorithm where device-level pulse shapes are variationally optimized for the state preparation rather than using an abstract-level quantum circuit. In doing so, the coherence time required for the state preparation is drastically reduced. We numerically demonstrate this by directly optimizing pulse shapes which accurately model the dissociation of H 2 and HeH + , and we compute the ground state energy for LiH with four transmons where we see reductions in state preparation times of roughly three orders of magnitude compared to gate-based strategies.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

[18F]Tosyl fluoride as a versatile [18F]fluoride source for the preparation of 18F-labeled radiopharmaceuticals

Abstract Positron emission tomography (PET) is an in vivo imaging technology that utilizes positron-emitting radioisotope-labeled compounds as PET radiotracers that are commonly used in clinic and in various research areas, including oncology, cardiology, and neurology. Fluorine-18 is the most widely used PET-radionuclide and commonly produced by proton bombardment of 18 O-enriched water in a cyclotron. The [ 18 F]fluoride thus obtained generally requires processing by azeotropic drying in order to completely remove H 2 O before it can be used for nucleophilic radiofluorination. In general, the drying step is important in facilitating the radiofluorination reactions and the preparation of 18 F-labeled PET radiotracers. In this communication, we have demonstrated the feasibility of using [ 18 F]tosyl fluoride ([ 18 F]TsF) as a versatile [ 18 F]fluoride source for radiofluorination to bypass the azeotropic drying step, and we have developed a continuous flow solid-phase radiosynthesis strategy to generate [ 18 F]TsF in a form that is excellent for radiofluorination. [ 18 F]TsF shows high reactivity in radiofluorination and provides the features suitable for preparing PET radiotracers on a small scale and exploring novel radiolabeling technologies. Thus, using [ 18 F]TsF as a [ 18 F]fluoride source is a promising strategy that facilitates radiofluorination and provides a convenient and efficient solution for the preparation of 18 F-labeled radiopharmaceuticals that is well matched to the emerging trends in PET imaging technologies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Effects of Serum and Compound Preparation Methods on Delayed Repolarization Evaluation With Human iPSC-CMs

Abstract Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been widely used in the Comprehensive in vitro Proarrhythmia Assay (CiPA). The notable difference of the electrophysiological (EP) responses of hiPSC-CMs in serum and serum-free media (SFM) is puzzling and may impact regulatory decision-making on the cardiac safety of candidate drugs in inducing QT prolongation and torsade de pointes (TdP). In this study, we compared the EP responses of hiPSC-CMs to 10 CiPA compounds and moxifloxacin in serum and SFM; explained the potential reason behind the different EP responses—abiotic compound loss to plastic tubes/plates of hydrophobic compounds prepared in SFM; and investigated the impact of compound preparation methods on drug bioavailability in exposure media, which affects the TdP risk prediction of drugs tested in serum-containing and SFM. For assays to be conducted in SFM, awareness of abiotic compound loss of hydrophobic compounds in serum-free preparations is critical for delay repolarization evaluation and data extrapolation from in vitro to in vivo.

Toxicology↗
DOE OSTI2022

Quantum state preparation by adiabatic evolution with custom gates

Quantum state preparation by adiabatic evolution is currently rendered ineffective by the long implementation times of the underlying quantum circuits, comparable to the decoherence time of present and near-term quantum devices. These implementation times can be significantly reduced by realizing these circuits with custom gates. Using classical computing, we model the output of a realistic two-qubit processor implementing the adiabatic evolution of a two-spin system by means of custom gates. This modeled output is then compared with the results of quantum simulations solving the same problem on IBM Quantum (IBMQ) systems. Additionally, when used to emulate the behavior of the IBMQ quantum circuit, our realistic model yields state fidelities ranging from 65% to 85%, similar to the actual performance of a diverse set of IBMQ devices. When we reduced the implementation time by using custom gates, however, the loss of fidelity was reduced by at least a factor of 4, allowing us to accurately extract the energy of the target state. This improvement is enough to render adiabatic evolution useful for quantum state preparation for small systems or as a preconditioner for other state preparation methods.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Preparing angular momentum eigenstates using engineered quantum walks

Coupled angular-momentum eigenstates are widely used in atomic and nuclear physics calculations and are building blocks for spin networks and the Schur transform. To combine two angular momenta J 1 and J 2 , forming eigenstates of their total angular momentum J=J 1 +J 2 , we develop a quantum-walk scheme that does not require inputting O(j 3 ) nonzero Clebsch–Gordan (CG) coefficients classically. In fact, our scheme may be regarded as a unitary method for computing CG coefficients on quantum computers with a typical complexity of O⁡(j) and a worst-case complexity of O⁡(j 3 ). Equivalently, our scheme provides decompositions of the dense CG unitary into sparser unitary operations. Our scheme prepares angular-momentum eigenstates using a sequence of Hamiltonians to move an initial state deterministically to desired final states, which are usually highly entangled states in the computational basis. In contrast with usual quantum walks, whose Hamiltonians are prescribed, we engineer the Hamiltonians in su⁡(2)×su⁡(2), which are inspired by, but different from, Hamiltonians that govern magnetic resonances and dipole interactions. To achieve a deterministic preparation of both ket and bra states, we use projection and destructive interference to double pinch the quantum walks, such that each step is a unit-probability population transfer within a two-level system. We test our state preparation scheme on classical computers, reproducing tables of CG coefficients. Finally, we also implement small test problems on current quantum hardware.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2025

Spatiotemporal quenches for efficient critical ground state preparation in the two-dimensional transverse field Ising model

Quantum simulators have the potential to shed light on the study of quantum many-body systems and materials, offering unique insights into various quantum phenomena. Although adiabatic evolution has been conventionally employed for state preparation, it faces challenges when the system evolves too quickly or the coherence time is limited. In such cases, shortcuts to adiabaticity, such as spatiotemporal quenches, provide a promising alternative. This paper numerically investigates the application of spatiotemporal quenches in the two-dimensional transverse field Ising model with ferromagnetic interactions, focusing on the emergence of the ground state and its correlation properties at criticality when the gap vanishes. We demonstrate the effectiveness of these quenches in rapidly preparing ground states in critical systems. Our simulations reveal the existence of an optimal quench front velocity at the emergent speed of light, leading to minimal excitation energy density and correlation lengths of the order of finite system sizes we can simulate. These findings emphasize the potential of spatiotemporal quenches for efficient ground state preparation in quantum systems, with implications for the exploration of strongly correlated phases and programmable quantum computing.

2-dimensional systems↗
DOE OSTI2025

State preparation of lattice field theories using quantum optimal control

Here, we explore the application of quantum optimal control (QOC) techniques to state preparation of lattice field theories on quantum computers. As a first example, we focus on the Schwinger model, quantum electrodynamics in 1+1 dimensions. We demonstrate that QOC can significantly speed up the ground state preparation compared to gate-based methods, even for models with long-range interactions. Using classical simulations, we explore the dependence on the interqubit coupling strength and the device connectivity, and we study the optimization in the presence of noise. While our simulations indicate potential speedups, the results strongly depend on the device specifications. In addition, we perform exploratory studies on the preparation of thermal states. Our results motivate further studies of QOC techniques in the context of quantum simulations for fundamental physics.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗