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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 1,405 records · Page 78
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Squeezed coherent states of motion for ions confined in quadrupole and octupole ion traps

Quasiclassical dynamics of trapped ions is characterized by applying the time dependent variational principle (TDVP) on coherent state orbits, in case of quadrupole and octupole combined (Paul and Penning) or radiofrequency (RF) traps. A dequantization algorithm is proposed, by which the classical Hamilton (energy) function associated to the system results as the expectation value of the quantum Hamiltonian on squeezed coherent states. We develop such method and particularize the quantum Hamiltonian for both combined and RF nonlinear traps, that exhibit axial symmetry. We also build the classical Hamiltonian functions for the particular traps we considered, and find the classical equations of motion.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

In situ TEM study of G-phase precipitates under heavy ion irradiation in CF8 cast austenitic stainless steel

Thermally-aged cast austenitic stainless steels (CASS) CF8 was irradiated with 1 MeV Kr ions at 300, 350 and 400°C to 1.88x10^15 ions/cm2 (~3 dpa) at the IVEM-Tandem Facility at the Argonne National Laboratory. Before irradiation, the distribution of G-phase precipitates in the ferrite showed strong spatial variations, and both their size and density were affected by the ferrite-austenite phase boundary and presence of M23C6 carbides. Under 300°C irradiation, in-situ TEM observation showed G-phase precipitates were relatively unchanged in the vicinity of the phase boundary M23C6 carbides, while the density of G-phase precipitates increased with increasing dose within the ferrite matrix. Coarsening of G-phase precipitates was observed in the vicinity of phase boundary M23C6 carbides at 350°C and 400°C.

Duplex stainless steel↗
DOE OSTI2015

Microstructural evolution in NF616 (P92) and Fe–9Cr–0.1C-model alloy under heavy ion irradiation

In this comparative study, in situ investigations of the microstructure evolution in a Fee9Cr ferritic emartensitic steel, NF616, and a Fee9Cre0.1C-model alloy with a similar ferriticemartensitic microstructure have been performed. NF616 and Fee9Cre0.1C-model alloy were irradiated to high doses (up to ~10 dpa) with 1 MeV Kr ions between 50 and 673 K. Defect cluster density increased with dose and saturated in both alloys. The average size of defect clusters in NF616 was constant between 50 and 573 K, on the other hand average defect size increased with dose in Fee9Cre0.1C-model alloy around ~1 dpa. At low temperatures (50e298 K), alignment of small defect clusters resulted in the formation of extensive defects in Fee9Cre0.1C-model alloy around ~2e3 dpa, while similar large defects in NF616 started to form at a high temperature of 673 K around ~5 dpa. Interaction of defect clusters with the lath boundaries were found to be much more noticeable in Fee9Cre0.1C-model alloy. Differences in the microstructural evolution of NF616 and Fee9Cre0.1C-model alloy are explained by means of the defect cluster trapping by solute atoms which depends on the solute atom concentrations in the alloys.

Ferritic-martensitic alloys↗
DOE OSTI2016

Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ high energy X-ray diffraction and X-ray absorption near edge spectroscopy [Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ HEXRD and XANES]

In situ high energy X-ray diffraction (HEXRD) and in situ X-ray absorption near edge spectroscopy (XANES) were carried out to understand the soild state synthesis of Na x MnO 2 , with particular interest on the synthesis of P2 type Na 2/3 MnO 2 . It was found that there were multi intermediate phases formed before NaMnO 2 appeared at about 600 °C. And the final product after cooling process is a combination of O'3 NaMnO 2 with P2 Na 2/3 MnO 2 . A P2 type Na 2/3 MnO 2 was synthesized at reduced temperature (600 °C). The influence of Na 2 CO 3 impurity on the electrochemical performance of P2 Na 2/3 MnO 2 was thoroughly investigated in our work. It was found that the content of Na 2 CO 3 can be reduced by optimizing Na 2 CO 3 /MnCO 3 ratio during the solid state reaction or other post treatment such as washing with water. Lastly, we expected our results could provide a good guide for future development of high performance cathode materials for sodium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2015

Design of surface protective layer of LiF/FeF 3 nanoparticles in Li-rich cathode for high-capacity Li-ion batteries

Advanced lithium-ion batteries for renewable energy storage applications have become a major research interest in recent years. Much better performance can be realized by improvements in the material surface design, especially for the cathode materials. Here, we present a new design for a surface protective layer formed via a facile aqueous solution process in which a nano-architectured layer of LiF/FeF 3 is epitaxially grown on bulk hierarchical Li-rich cathode Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 . Coin cell tests of this material in the voltage range of 2–4.8 V indicated a high reversible capacity (260.1 mA h g -1 at 0.1 C), superior rate performance (129.9 mA h g -1 at 20 C), and excellent capacity retention. Differential scanning calorimetry showed good thermal stability. The enhanced capacity and cycling stability are attributed to the suppression of interfacial side reactions as well as the conversion reaction resulting from the introduction of LiF/FeF 3 as a surface protective layer.

Iron fluoride↗
DOE OSTI2020

Unravelling high-temperature stability of lithium-ion battery with lithium-rich oxide cathode in localized high-concentration electrolyte

Lithium (Li)-rich manganese (Mn)-rich oxide (LMR) cathode materials, despite of the high specific capacity up to 250 mAh g-1 suffer from instability of cathode/electrolyte interfacial layer at high working voltages, causing continuous voltage decay and capacity fading, especially at elevated temperatures. In various battery systems, localized high-concentration electrolytes (LHCEs) have been widely reported as a promising candidate to form effective electrode/electrolyte interphases. Here, an optimized LHCE is studied in graphite (Gr)-based full cells being cycled at 25, 45 and 60 °C with the reference of a conventional LiPF6-based electrolyte. It is revealed that the LHCE can effectively suppress continuous electrolyte decompositions and mitigate the dissolution of Mn ions due to the formation of more protective electrode/electrolyte interphases on both anode and cathode, which, in turn, lead to significantly improved cycling stability and enhanced rate capability under the selected temperatures. The mechanistic understanding on the failure of the conventional LiPF6-containing electrolyte and the function of the LHCE in Gr||LMR cells under high temperatures provides valuable perspectives of electrolyte development for practical application of LMR cathodes in high energy density batteries over a wide temperature range.

Localized high-concentration electrolyte, Lithium-↗
DOE OSTI2018

Application of multiplexed ion mobility spectrometry towards the identification of host protein signatures of treatment effect in pulmonary tuberculosis

Rationale: The monitoring of TB treatments in clinical practice and clinical trials relies on traditional sputum-based culture status indicators at specific time points. Accurate, predictive, blood-based protein markers would provide a simpler and more informative view of patient health and response to treatment. Objective: We utilized sensitive, high throughput multiplexed ion mobility-mass spectrometry (IM-MS) to characterize the serum proteome of TB patients at the start of and at 8 weeks of rifamycin-based treatment. We sought to identify treatment specific signatures within patients as well as correlate the proteome signatures to various clinical markers of treatment efficacy. Methods: Serum samples were collected from 289 subjects enrolled in CDC TB Trials Consortium Study 29 at time of enrollment and at the end of the intensive phase (after 40 doses of TB treatment). Serum proteins were immunoafinity-depleted of high abundant components, digested to peptides and analyzed for data acquisition utilizing a unique liquid chromatography IM-MS platform (LC-IM-MS). Linear mixed models were utilized to identify serum protein changes in the host response to antibiotic treatment as well as correlations with culture status end points. Results: A total of 10,137 peptides corresponding to 872 proteins were identified, quantified, and used for statistical analysis across the longitudinal patient cohort. In response to TB treatment, 244 proteins were sig- ni?cantly altered. Pathway/network comparisons helped visualize the interconnected proteins, identifying up regulated (lipid transport, coagulation cascade, endopeptidase activity) and down regulated (acute phase) processes and pathways in addition to other cross regulated networks (inflammation, cell adhesion, extracellular matrix). Detection of possible lung injury serum proteins such as HPSE, significantly downregulated upon treatment. Analyses of microbiologic data over time identified a core set of serum proteins (TTHY, AFAM, CRP, RET4, SAA1, PGRP2) which change in response to treatment and also strongly correlate with culture status. A similar set of proteins at baseline were found to be predictive of week 6 and 8 culture status. Conclusion: A comprehensive host serum protein dataset reflective of TB treatment effect is defined. A repeating set of serum proteins (TTHY, AFAM, CRP, RET4, SAA1, PGRP2, among others) were found to change significantly in response to treatment, to strongly correlate with culture status, and at baseline to be predictive of future culture conversion. If validated in cohorts with long term follow-up to capture failure and relapse of TB, these protein markers could be developed for monitoring of treatment in clinical trials and in patient care.

Kedia, Komal↗