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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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Anode Overpotential Control via Interfacial Modification: Inhibition of Lithium Plating on Graphite Anodes
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Origin of graphitic filaments on improving the electron field emission properties of negative bias-enhanced grown ultrananocrystalline diamond films in CH{sub 4}/Ar plasma
Microstructural evolution of bias-enhanced grown (BEG) ultrananocrystalline diamond (UNCD) films has been investigated using microwave plasma enhanced chemical vapor deposition in gas mixtures of CH{sub 4} and Ar under different negative bias voltages ranging from −50 to −200 V. Scanning electron microscopy and Raman spectroscopy were used to characterize the morphology, growth rate, and chemical bonding of the synthesized films. Transmission electron microscopic investigation reveals that the application of bias voltage induced the formation of the nanographitic filaments in the grain boundaries of the films, in addition to the reduction of the size of diamond grains to ultra-nanosized granular structured grains. For BEG-UNCD films under −200 V, the electron field emission (EFE) process can be turned on at a field as small as 4.08 V/μm, attaining a EFE current density as large as 3.19 mA/cm{sup 2} at an applied field of 8.64 V/μm. But the films grown without bias (0 V) have mostly amorphous carbon phases in the grain boundaries, possessing poorer EFE than those of the films grown using bias. Consequently, the induction of nanographitic filaments in grain boundaries of UNCD films grown in CH{sub 4}/Ar plasma due to large applied bias voltage of −200 V is the prime factor, which possibly forms interconnected paths for facilitating the transport of electrons that markedly enhance the EFE properties.
120 GeV neutrino physics graphite target damage assessment using electron microscopy and high-energy x-ray diffraction
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Roller Coaster in a Flatland: Magnetoresistivity in Eu-Intercalated Graphite
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Predicting High-Temperature Decomposition of Lithiated Graphite: Part I. Review of Phenomena and a Comprehensive Model
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Diffusivities of Ag, Cs, Sr, and Kr in TRISO fuel particles and graphite
Tri-structural isotropic (TRISO) coated particles have been developed and studied since the late 1950s when the concept of coated particles was invented by Roy Huddle of the United Kingdom Atomic Energy Authority. Several decades of work by half a dozen countries on fission product transport in TRISO fuel through numerous irradiation and heating experiments have led to several recommendations of transport data and to the adoption of various sets of diffusion coefficients. In 1997, the International Atomic Energy Agency (IAEA) gathered all these historical results and issued a technical document (TECDOC-978 [IAEA]) that summarizes these sets of recommended diffusion coefficients. Table 1 shows the reference literature articles for the diffusivities that have historically been recommended by the American and German TRISO fuel development programs and that are summarized in the IAEA report (see section 7 for full references of these articles).
Quantifying Lithium Ion Exchange in Solid Electrolyte Interphase (SEI) on Graphite Anode Surfaces
Solid Electrolyte Interphase (SEI) has been identified as the most important and least understood component in lithium-ion batteries. Despite extensive studies in the past two decades, a few mysteries remain: what is the chemical form of and degree of mobility of Li + in the interphase? What fraction of Li + is permanently immobilized in the SEI, while the rest are still able to participate in the cell reactions via the ion-exchange process with Li + in the electrolyte? This study attempted to answer, in part, these questions by using 6 Li and 7 Li-isotopes to label SEIs and electrolytes, and then quantifying the distribution of permanently immobilized and ion-exchangeable Li + with solid-state NMR and ToF-SIMS. The results showed that the majority of Li + were exchanged after one SEI formation cycle, and a complete exchange after 25 cycles. Ion exchange by diffusion based on concentration gradient in the absence of applied potential also occurred simultaneously. This knowledge will provide a foundation for not only understanding but also designing better SEIs for future battery chemistries.
PREDICTIVE MODEL FOR CHRONIC OXIDATION OF NUCLEAR GRAPHITE UNDER NORMAL OPERATING CONDITIONS OF HIGH TEMPERATURE GAS-COOLED REACTORS
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Assessment of elastic anisotropy in nuclear graphites using laser ultrasonic shear wave birefringence measurements
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Graphite Irradiation Data Analysis
Future ASME Code Development and Reactor Deployment
Performance of Graphite Oxidation with Environment and Specimen Geometry
Introduction -Motive for the study (a modest request) •Issues that must be considered -Pertinent oxidation background information •Three oxidation regimes -ASTM D7542 • The primary parameters for oxidation control -Energy of the System -Atmosphere -Reaction Interface
Battery Grade Graphite Production from Biomass, US DOE SBIR Phase I Final Report, DOE_DE-SC0024994_I_Final_OSTI
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Electrically Conductive Ultrananocrystalline Diamond-Coated Natural Graphite-Copper Anode for New Long Life Lithium-Ion Battery
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