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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 271 records · Page 15

Carbon nanotube (CNT) reinforced 316L stainless steel composites made by laser powder bed fusion: Microstructure and wear response

Carbon nanotube (CNT) reinforced 316L stainless steel (SS) composites were fabricated by laser powder bed fusion (LPBF) additive manufacturing (AM). This study focuses on microstructure evolution, hardness, and wear behavior. The wear behavior for AM 316L SS and 1 wt% CNT/316L SS was studied by a dry sliding test under normal loads of 10, 15, and 25 N. The addition of CNT to 316L SS led to the change of solidification mode from cellular/columnar to dendritic growth, producing grain refinement. Nanoscale dendrites were observed. Although TEM characterization confirmed the existence of CNT in cell interior, most CNT were damaged, resulting in carbon material segregation along cellular/dendritic boundaries. The wear rate was found dramatically decreased due to the improved hardness. Compared to the adhesive and abrasive wear in AM 316L SS, the wear mechanism of CNT/316L composite was adhesion and oxidative wear. Furthermore, enhanced cellular/dendritic boundary strengthening by carbon segregation was the main strengthening mechanism of CNT/316L composite.

36 MATERIALS SCIENCE↗

Si-based materials for lithium-ion batteries VIII. 90% surface-modified Si/C-lithiated polyacrylic acid electrode

X-ray photoelectron spectroscopy was used to analyze a 90% Si/C-lithiated polyacrylic acid electrode fabricated at the Cell Analysis, Modeling, and Prototyping Facility (CAMP), Argonne National Laboratory. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.834 01 nm). An initial survey spectrum together with O 1s, C 1s, and Si 2p are presented. A final survey spectrum was collected to ascertain the amount of beam-induced damage, which appears to be minimal. Finally, the spectra indicate the principal core level photoelectron and Auger electron signals with only minor lithium signal and show the expected silicon-carbon species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure as well contributions related to the binder material.

25 ENERGY STORAGE↗

Progress on Producing an ODS Ferritic Alloy by High Deformation Processing of Reactive Powders

Oxide dispersion-strengthened (ODS) ferritic alloys, such as 14YWT, are considered as benchmarks for fuel cladding and core structural materials in advanced nuclear energy reactor systems that require high temperature strength and creep properties as well as resistance to radiation damage. Unfortunately, the popular processing method of mechanical alloying (MA) is time-consuming, incurs high manufacturing costs, and typically produces anisotropy in the microstructure and mechanical properties of ODS ferritic alloys. These considerations hinder their acceptance in many high-performance, high-temperature materials for advanced nuclear energy reactors. This work package is pursuing an alternative solid-state processing to MA involving high deformation at high temperatures for producing an ODS ferritic alloy for fuel cladding. This report summarizes the concept for this processing method and the progress toward selecting the reactive and ferritic alloy powders, preparing 316L stainless steel cans for filling with blended powder followed by degassing, and choosing the heat treatments and forging parameters for performing the first two forging experiments. The preliminary results of optical microscopy performed on polished samples that were cut in three orthogonal directions revealed remnant porosity in both samples. The analysis of the porosity using ImageJ revealed a lesser amount of ~2.49% in the HiLoMe-1 sample that was processed with the three heat treatments and forging parameters compared to ~5.70% for the Hi-1 sample that was processed with only the first sintering heat treatment and forging parameter. These initial results will provide insights that can be leveraged to improve the densification of the powders in future forging experiments that will be continued into FY24 for determining the optimum heat treatments and forging parameters coupled with detailed microstructure characterization studies for producing the ODS ferritic alloy.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

A Reactive Inkjet Printing Process for Fabricating Biodegradable Conductive Zinc Structures

A novel reactive inkjet printing (RIJ) process for fabricating environmentally benign, conductive zinc structures on biodegradable substrates is reported. A precursor consisting of oxidized zinc microparticles is formulated into a viscous ink for high‐resolution, high‐repeatability screen printing. A single RIJ process is performed to selectively dispense an acid‐based oxide etching agent onto the screen‐printed zinc ink to significantly improve its electrical conductivity, up to 4 × 10 4 S m −1 . The RIJ process enables precise control of the amount of deposited etching agent, allowing control of conductivity and avoiding damage caused by excessive acid exposure. The RIJ process deposits the etching agent selectively on the screen‐printed, water‐soluble zinc patterns, thus preserving the print fidelity by avoiding ink smearing that can occur when using a blanket treatment such as submersion. A printed biodegradable antenna with a minimum feature size of 500 μm for use with a batteryless radio frequency identification (RFID) chip is fabricated as demonstration. Due to the higher ink conductivity and improved pattern fidelity, the antenna fabricated by the RIJ process shows a ≈2.2× increase in reading distance compared with a similar antenna that is screen printed and activated using a drop‐casting process.

Sui, Yongkun↗

Si-based materials for lithium-ion batteries VI. 15% surface-modified Si/C-graphite/carbon black/lithiated polyacrylic acid electrode

X-ray photoelectron spectroscopy was used to analyze a 15%Si/C-graphite/carbon black/lithiated polyacrylic acid electrode fabricated at the Cell Analysis, Modeling, and Prototyping Facility (CAMP), Argonne National Laboratory. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.83 401 nm). An initial survey spectrum together with O 1s, C 1s, and Si 2p are presented. A final survey spectrum was collected to ascertain the amount of beam-induced damage, which appears to be minimal. The spectra indicate the principal core level photoelectron and Auger electron signals with only minor nitrogen and lithium signals and show the expected silicon-carbon species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure as well contributions related to the binder material.

17 WIND ENERGY↗

Infrared nanospectroscopy characterization of metal oxide photoresists

Implementation of extreme ultraviolet (EUV) lithography in high-volume semiconductor manufacturing requires a reliable and scalable EUV resist platform. A mechanistic understanding of the pros and cons of different EUV resist materials is critically important. However, most material characterization methods with nanometer resolution use an x-ray photon or electron beam as the probe, which often cause damage to the photoresist film during measurement. Here, we illustrated the use of non-destructive infrared nanospectroscopy [or nano-Fourier-Transform infrared spectroscopy (nano-FTIR)] to obtain spatially resolved composition information in patterned photoresist films. Further, clear evidence of exposure-induced chemical modification was observed at a spatial resolution down to 40 nm, well below the diffraction limit of infrared light. With improvements, such a nano-FTIR technique with nanoscale spatial resolution, chemical sensitivity, and minimal radiation damage can be a promising candidate for the fundamental study of material properties relevant to EUV lithography.

36 MATERIALS SCIENCE↗

Electron emissions and hot spots in dual-phase LXe TPCs

Persistent photon and single-electron emissions - in the form of “electron trains” and localized “hot spots” - have been observed in multiple dual-phase liquid xenon (LXe) time projection chambers (TPCs), often persisting long after ionizing events. Here, we show that these phenomena are naturally explained by photon-triggered single-electron emission from resistive mixed-oxide films on stainless-steel (SS304 or s.s.) wires, which behave as leaky capacitors with long RC time constants at LXe temperature. Positive ions landing on these oxides can further enhance local fields and drive Malter-like electron emission. We outline the materials physics (Cr 2 O 3 /Cr 2 O 3-x /Cr(OH) 3 mosaics), quantify expected time scales (∼1 s under illumination), and demonstrate how small damaged regions with enhanced QE can produce persistent hot spots.

Va'vra, J. [SLAC National Accelerator Laboratory (↗

Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn): High Chemical Flexibility Resulting in Good Nonlinear-Optical Properties

Seven acentric sulfides Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) were grown by a high-temperature salt flux method. The crystal structures of the Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) compounds were determined by single-crystal X-ray diffraction with the aid of solid-state NMR spectroscopy. The Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi) compounds are isostructural and crystallize in the Ba 6 Ag 4 Sn 4 S 16 structure type. The Sn-containing compound exhibits high structural similarity to Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi) with the presence of an interstitial atomic position partially occupied by Sn atoms. The chemical bonding characteristics of Ba 6 (Cu 2.9 Sn 0.4 )Sn 4 S 16 were understood with electron localization function calculations coupled with crystal orbital Hamilton population calculations. The Ba–S and Cu–S interactions are dominantly ionic, but the Sn–S interactions consist of strong covalent bonding characteristics in Ba 6 (Cu 2.9 Sn 0.4 )Sn 4 S 16 . The monovalent Cu atoms, mixed with certain metals with various oxidation states, significantly shift the optical properties of the Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi) compounds. This results in a good balance between the second-harmonic-generation (SHG) response and laser damage threshold (LDT). Ba 6 (Cu 1.9 Zn 1.1 )Sn 4 S 16 possesses a high SHG response and a high LDT of 2.8 × AGS and 3 × AGS, respectively. Here, a density functional theory calculation revealed that CuS 4 and SnS 4 tetrahedra significantly contribute to the SHG response in Ba 6 (Cu 2 Mg)Sn 4 S 16 , which also confirmed that CuS 4 tetrahedra are crucial for the stability and optical properties of the Ba 6 (Cu x Z y )Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) compounds revealed by electronic structure analysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Si-based materials for lithium-ion batteries II. Surface-modified Si/C/polyethylene glycol powder

X-ray photoelectron spectroscopy was used to analyze Si/C/polyethylene glycol powder obtained from Paraclete Energy, Inc. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.834 01 nm). An initial survey spectrum together with O 1s, C 1s, and Si 2p are presented. A final survey spectrum was collected to ascertain the amount of beam-induced damage, which appears to be minimal. Finally, the spectra indicate the principal core level photoelectron and Auger electron signals, with only minor calcium and nitrogen signal, and show the expected silicon-carbon species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure.

25 ENERGY STORAGE↗

Si-based materials for lithium-ion batteries IX: 70% surface-modified Si/C/polyethylene glycol-carbon black/lithiated polyacrylic acid electrode

X-ray photoelectron spectroscopy was used to analyze a 70% Si/C-carbon black/polyethylene glycol/lithiated polyacrylic acid electrode fabricated at the Cell Analysis, Modeling, and Prototyping Facility (CAMP), Argonne National Laboratory. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.834 01 nm). An initial survey spectrum together with O 1s, C 1s, and Si 2p are presented. A final survey scan was collected to ascertain the amount of beam-induced damage, which appears to be minimal. Finally, the spectra indicate the principal core level photoelectron and Auger electron signals with only minor copper and lithium signals and show the expected silicon-carbon species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure as well as contributions related to the binder material.

25 ENERGY STORAGE↗

Optimized Viewing Techniques to Minimize Radiation Damage From X-ray Imaging Systems

X-ray inspection of ball grid arrays (BGAs) is typically performed at one or more viewing angles to examine adhesion sites for errors such as voids, joint cracking, or head-in-pillow. During this inspection process, the cir cuit board assembly is subject to ionizing radiation exposure, which can cause trapped charge within oxide layers of semiconductor devices. Some x-ray machines allow for programmable inspection routines, which could be used to optimize radiation exposure to semiconductor components. Using Monte Carlo methods, x-ray inspection of a BGA was simulated to determine a range of acceptable viewing angles. Dose rates to circuit board components were estimated at each inspection angle to determine the view resulting in optimized radiation exposure. Results showed that for each BGA, the maximum unobstructed viewing times without exceeding a 5 Gy dose limit to a single part ranged from 82 to 94 minutes. Using a radiation cost function method, optimized viewing across all components was found. Here, it was observed that for a consistent dose limit applied to silicon-based components, performing inspection with BGAs facing the x-ray source was optimal. A third method was applied, assigning individual dose limits based on empirical data from the NASA Goddard Space Flight Center radiation database. This method showed that optimized viewing maximizes the distance between the radiation source and highly sensitive components. It was also observed that cumulative effects from viewing two BGAs will influence viewing angles, causing the optimal view of one BGA to exist nearly 180° from the other.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Voltage cycling as a dynamic operation mode for high temperature electrolysis solid oxide cells

Solid Oxide Electrolysis Cells (SOECs) have emerged as a promising technology for the efficient production of H2 via high-temperature electrolysis. However, power input from dynamic energy sources remains a significant challenge for their long-term stability. It is important to analyze the tolerance of cells under dynamic operation conditions. This study focuses on evaluating the impact of voltage cycling on the performance and durability of electrode-supported SOECs. We explore the operational limits and degradation mechanisms of SOECs subjected to various voltage conditions and find that the cells have high tolerance for dynamic voltage. Voltage cycling between 1.3 V and 1.5 V for 9000 cycles does not damage the cell. Conversely, cycling to higher voltages (≥1.7 V) results in accelerated degradation. Advanced characterization is used to screen for various degradation modes post operation. Within the oxygen electrode, XRD and STEM EDS find compositional and phase evolution in all voltage cycled samples including increased decomposition of the air electrode resulting in cation migration. Microstructural analysis of the fuel electrode from nano-CT data shows minimal change throughout the sample set and no evidence of Ni migration, indicating the fuel electrode is stable and not impacted by cycling to higher voltages within the timeframe studied.

Zhu, Zhikuan↗

Magneto mitochondrial dysfunction mediated cancer cell death using intracellular magnetic nano-transducers

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein, magnetic nano-transducers, which convert external magnetic fields into physical stress, are designed to induce mitochondrial dysfunction to remotely kill cancer cells. Spindle-shaped iron oxide nanoparticles were synthesized to maximize cellular internalization and magnetic transduction. The magneto-mechanical transduction of nano-transducers in mitochondria enhances cancer cell apoptosis by promoting a mitochondrial quality control mechanism, referred to as mitophagy. Furthermore, in the liver cancer animal model, nano-transducers are infused into the local liver tumor via the hepatic artery. After treatment with a magnetic field, in vivo mitophagy-mediated cancer cell death was also confirmed by mitophagy markers, mitochondrial DNA damage assay, and TUNEL staining of tissues. This study is expected to contribute to the development of nanoparticle-mediated mitochondria-targeting cancer therapy and biological tools, such as magneto-genetics.

60 APPLIED LIFE SCIENCES↗

A Transformational Natural Gas Fueled Dynamic SOFC for Data Center in-Rack Power (Final Technical Report)

Data centers consume 250TWh or 1% of global electricity use in 2019. This electricity demand is expected to grow exponentially in the future. The current data center power supply relies on electric grids with diesel engines and batteries as backup; the latter is critically important because a sudden loss of power could erase crucial data, causing catastrophic economic loss. However, such a double protection architecture is costly, inefficient and polluting. In search for better in-rack power system, fuel-cell based generators have recently emerged as a promising alternative to diesel engines and batteries because of its potential to be more cost-effective, more efficient and less polluting. Among many types of fuel cells, solid oxide fuel cells stand out to be a front runner because of their ability to directly operate on natural gas that has an existing infrastructure. However, there are several critical challenges facing SOFC generators to meet the rigorous power requirements of data centers: high cost, poor reliability and more importantly, slow response to the datacenters’ dynamic load change. The unexpected overload conditions in data centers can cause fuel starvation; the latter can initiate microcracks in the anode structure, thus jeopardizing the lifetime of the SOFC generator. The current efforts to increase transient power capabilities of traditional SOFCs and therefore protect SOFC stacks from internal damage during transient loading, rely primarily upon mathematical algorithms. One of the challenges to these control methodologies is the physical limitations of the fuel delivery system such as slow response of mass flow controllers to fast power demand.

30 DIRECT ENERGY CONVERSION↗

Si-based materials for lithium-ion batteries III: Surface-modified Si/C/polyvinylidine difluoride powder

X-ray photoelectron spectroscopy was used to analyze Si/C/polyvinylidine difluoride powder obtained from Paraclete Energy Inc. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.834 01 nm). An initial survey spectrum together with F 1s, O 1s, C 1s, and Si 2p are presented. A final survey spectrum was collected to ascertain the amount of beam-induced damage, which appears to be minimal. Finally, the spectra indicate the principal core level photoelectron and Auger electron signals with only minor nitrogen signal and show the expected silicon-carbon and silicon-fluorine species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure.

25 ENERGY STORAGE↗

Si-based materials for lithium-ion batteries VII. 70% surface-modified Si/C-carbon black/lithiated polyacrylic acid electrode

X-ray photoelectron spectroscopy (XPS) was used to analyze a 70% Si/C-carbon black/lithiated polyacrylic acid electrode fabricated at the Cell Analysis, Modeling, and Prototyping Facility (CAMP), Argonne National Laboratory. The spectra were obtained using incident monochromatic Al K α radiation at 1486.6 eV (0.834 01 nm). An initial survey spectrum together with O 1s, C 1s, and Si 2p are presented. A final survey spectrum was collected to ascertain the amount of beam-induced damage, which appears to be minimal. Finally, the spectra indicate the principal core level photoelectron and Auger electron signals with only minor copper, nitrogen, calcium, and lithium signals and show the expected silicon-carbon species related to the surface modification process in addition to oxidized carbon and silicon due to atmospheric exposure as well contributions related to the binder material.

25 ENERGY STORAGE↗

Effects of Residual Water on Storage Canister Internal Components

This report describes an evaluation of the spent nuclear fuel cladding and canister internal materials’ corrosion/oxidation due to (inadvertent) residual free water inside a dry storage canister post-dryout. Drying of spent nuclear fuel (SNF) and the impact of (inadvertent) residual water in a SNF canister is being addressed under the DOE-NE Spent Fuel and Waste Science and Technology (SFWST) program to ensure the safe extended dry storage and transportation of commercial SNF. A long-standing understanding has been that the amount of residual water in a storage canister after vacuum drying is not expected to be much more than trace amounts of 0.43 gram mole. However, recent findings from the High Burnup Demonstration project, and an Integrated Research Project show that residual free water well above the amount of approximately 0.43 gm-moles that had been assumed for a 3 torr rebound pressure, may remain within an SNF canister following prototypic drying. In fact, an NRC-NMSS sponsored study considered residual water amount as high as 55 moles. Considering the recent findings and the NRC-sponsored work, this present work was conducted to study the effects of unspecified amount of residual water on oxidation and corrosion of canister internals, i.e., it was assumed that the residual water amount is not limiting. It was assumed that the spent nuclear fuel content in the canister is not exposed to the internal environment, i.e., the packaged canister does not contain any damaged (breached) fuel.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

A physics-informed multi-agents model to predict thermo-oxidative/hydrolytic aging of elastomers

This paper introduces a novel physics-informed multi-agents constitutive model to propose prediction in quasi-static constitutive behavior of cross-linked elastomer and the loss of mechanical performance during environmental aging. The presented model is used to simulate the effect of single-mechanism chemical aging (i.e. thermal-inducedor hydrolytic aging) on the behavior of the material in this hybrid framework. Those environmental single-mechanism damages change the polymer matrix over time due to massive chain scission, chain formations, and changing the arrangement of molecules in the polymer matrix. Here we propose a data-driven super-constrained machine-learned engine to represent damage in the polymer matrix and capture the changes in material behavior, including its inelastic features such as Mullins effect and permanent set in the course of aging. We have simplified the 3D stress–strain tensor mapping problem into a small number of super-constrained 1D mapping problems by means of a sequential order reduction. An assembly of multiple replicated conditional neural-network learning-agents (L-agents) is trained to systematically simplify the high-dimensional mapping problem into multiple 1D problems, each represented by a different type of agent. Our hybrid framework is designed to capture the effect of deformation history, aging time, and aging temperature. The model is validated with respect to a comprehensive set of experiments specifically designed to benchmark model capabilities and also against available data in the literature. Thermodynamic consistency and frame independency have been verified. Besides acceptable predictive abilities, a significant reduction of computational cost to predict behavior at multiple states of deformation is the most significant feature of this model.

42 ENGINEERING↗