Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “SHINE”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3

Component Testing Supporting SHINE Medical Technologies

SHINE is going to be implementing a tritium gas processing system to support their Mo-99 work. They have requested that the Hydrogen Process Group of SRNL does some required testing on the system components before startup. The lab plans on conducting both seismic and valve testing. Test Plan: - Testing 10 1C valves 750,000 cycles or until failure; - Testing intervals will be every couple thousand; - 1C valves will have metal stem tips instead of Polymer due to being in a tritium prone area; - Hope that the valves will still have enough force to create a sufficient seal with metal stem tips; - Goal is for a more cost and space efficient alternative to the 5C valves. Status: - Received half the parts, waiting on the other half due to long procurement times; - Waiting on the LabVIEW program which will perform the testing. Path Forward: - R and DE to change out the stem tips (July 2018); - Assemble Manifold (July 2018); - Perform Testing (August 2018); - Report (September 2018). Since SRNL does not own a shaker table, the test will be conducted at a facility like the NTS Facility in Huntsville, Alabama. Test Plans: - Leak Testing; - Use LabVIEW to monitor for leaks before, during and after seismic testing with an Electronic Pressure Transducer; - If leak is detected, sniff for location using Helium Leak Detector; - Connector Testing; - Use LabVIEW to test for electrical continuity before, during and after seismic testing; - If a connectors continuity is interrupted, further testing will be performed; - Each Pin in faulty connector will be testing to determine specific location of disruption. Path Forward: - Pick a Qualified Vender for testing (July 2018); - Procure the connector plugs (July 2018); - Send components and test plan to facility for testing (August 2018); - Perform Testing (August-September 2018); - Report Results (September 2018)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Shining a spotlight on intact proteins

Cells react to cues from their environment using various mechanisms that include changes in metabolites, gene expression, protein binding partners, protein localization, and protein posttranslational modifications (PTMs), all of which contribute to altered cellular signatures that enable appropriate cellular responses. Given the seemingly infinite number of mechanisms available to affect protein function and modulate biological processes, the question arises as to how cells manage to interpret protein readouts to accomplish the appropriate cell-type specific response to a particular stimulus.

Environmental Molecular Sciences Laboratory↗

Shining light on nanoscale ‘vine-on-stick’ eutectic structures in the Al-Ce-Ni system

Multiphase eutectics often comprise entangled solid phases with nanoscale periodicity, making it difficult to unravel their 3D connectivity using conventional 2D techniques. Among such systems, the three-phase eutectic Al-Al 11 Ce 3 -Al 3 Ni stands out for its ultrafine (∼100 nm) interphase spacing and promising creep resistance, yet its microstructure remains relatively unexplored despite its potential for high-temperature applications. Here, we use scanning hard X-ray microscopy with an unprecedented ∼10 nm pixel size to resolve its 3D morphology. Reconstructions reveal a novel “vine-on-stick” motif, wherein Al 11 Ce 3 wraps around Al 3 Ni pillars. Analysis of phase tortuosities confirms that Al 11 Ce 3 exhibits more convoluted morphologies than Al 3 Ni. No orientation relationship was observed between the two intermetallics, suggesting that growth is controlled by local solute gradients rather than epitaxy. Fragmentation of intermetallics along their longitudinal axis suggests a Rayleigh-type breakup mechanism in solid state. The “vine-on-stick” pattern may generalize to other alloy systems with variable interfacial anisotropies and low mutual solubilities.

36 MATERIALS SCIENCE↗

Shining Light on Halide Perovskites: Teaching Analytical Chemistry Using Flexible, Inquiry-Based Experiments

Two-dimensional (2D) metal halide perovskites are promising next generation semiconducting materials at the forefront of research in solar cells, LEDs, and other devices. Here, we report on an undergraduate intermediate analytical chemistry laboratory experience where students were taught fundamental chemistry concepts, including solubility, complexation, spectroscopy, and microscopy, through the introduction and study of 2D halide perovskite materials. Students explore multiple facets of perovskite synthesis, structure, and properties through a modular set of experiments that students used to form a holistic picture of this material. Importantly, this inquiry-based lab supports students through a guided research process, and students report high interest and learning gains from an end of the semester survey. We further discuss ways to adapt this lab to course, student, equipment, and budget needs. Overall, this laboratory experience teaches and applies the fundamental concepts and tools of analytical chemistry to the contemporary materials research field.

Analytical Chemistry↗

Shining a Light on Some Fundamental Research Opportunities in Semiconductor Photoelectrochemistry

Decades of research in semiconductor photoelectrochemistry have yielded a deep understanding of charge transfer, energetics, and stability at solid−liquid interfaces. Theoretical frameworks developed by Gerischer and contemporaries, together with extensive experimental validation, have clarified the key principles affecting the interfacial kinetics and energetics of semiconductor photoelectrodes. Nevertheless, significant opportunities remain for advances in fundamental understanding of semiconductor photoelectrochemistry. Exciting opportunities include exploiting advances in theory, synthesis, and instrumentation to determine the chemical identity and reactivity of surface states; exerting control of band-edge energetics through molecular-level surface modification processes; and systematically improving emerging photoelectrode protection strategies to enable long-term photoelectrode operation under both oxidative and reductive conditions. Advanced morphologies, such as nanowire and microwire arrays, present new pathways to combine efficient light absorption with effective charge collection and catalyst integration. Unique light−matter interactions during photoelectrochemical deposition of p-type semiconductors readily allow preparation at scale of complex 3D morphologies that are difficult, if not impossible, to access by other methods. Continued exploration of these avenues will expand the fundamental understanding of semiconductor−liquid interfaces and could additionally advance the realization of efficient, stable, and scalable systems for solar fuel generation and other emerging photoelectrochemical applications.

Bean, Paul J. L. [California Institute of Technolo↗

Perovskite Solar Cells Shine in the “Valley of the Sun”

'Perovskite-Based Photovoltaics and Optoelectronic Devices' (Symposium EP3) was one of the most active symposiums in the Material Research Society (MRS) Spring Meeting 2016 (March 28-April 1) held in Phoenix, Arizona -- the 'Valley of the Sun.' A large number of scientists and engineers from academia and industry met together to discuss the progress of perovskite solar cells (PSCs) and the understanding of the critical science related to PSCs. This symposium included 18 invited talks, 67 contributing talks, 130 posters, and more than 300 participants. These numbers clearly indicate that the surge in research interest continues in this emerging solar cell technology. Just a couple of months before this symposium, a new power conversion efficiency (PCE) record of 22.1% was released by Sang Il Seok's group (KRICT/UNIST, South Korea). Such a swift rise of PSC efficiency within only 6 years has been unprecedented in the history of photovoltaic (PV) technology. Of course, several challenges remain (for example, scaled-up fabrication, stability, toxicity, and hysteresis) before PSCs can successfully enter the PV market. However, the perceived huge potential of this future lab-to-market transition has stimulated myriad efforts from both the scientific community and industry. This symposium reported some of the recent achievements in the context of addressing these challenges.

14 SOLAR ENERGY↗

Shining light on the microscopic resonant mechanism responsible for cavity-mediated chemical reactivity

Strong light–matter interaction in cavity environments is emerging as a promising approach to control chemical reactions in a non-intrusive and efficient manner. The underlying mechanism that distinguishes between steering, accelerating, or decelerating a chemical reaction has, however, remained unclear, hampering progress in this frontier area of research. We leverage quantum-electrodynamical density-functional theory to unveil the microscopic mechanism behind the experimentally observed reduced reaction rate under cavity induced resonant vibrational strong light-matter coupling. We observe multiple resonances and obtain the thus far theoretically elusive but experimentally critical resonant feature for a single strongly coupled molecule undergoing the reaction. While we describe only a single mode and do not explicitly account for collective coupling or intermolecular interactions, the qualitative agreement with experimental measurements suggests that our conclusions can be largely abstracted towards the experimental realization. Specifically, we find that the cavity mode acts as mediator between different vibrational modes. In effect, vibrational energy localized in single bonds that are critical for the reaction is redistributed differently which ultimately inhibits the reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Intramolecular sensitization of americium luminescence in solution: Shining light on short-lived forbidden 5f transitions

In this study, the photophysical properties and solution thermodynamics of water soluble trivalent americium (Am III ) complexes formed with multidentate chromophore-bearing ligands, 3,4,3-LI(1,2-HOPO), Enterobactin, and 5-LIO(Me-3,2-HOPO), were investigated. The three chelators were shown to act as antenna chromophores for AmIII, generating sensitized luminescence emission from the metal upon complexation, with very short lifetimes ranging from 33 to 42 ns and low luminescence quantum yields (10 –3 to 10 –2 %), characteristic of Near Infra-Red emitters in similar systems. The specific emission peak of Am III assigned to the 5 D 1 → 7 F 1 f–f transition was exploited to characterize the high proton-independent stability of the complex formed with the most efficient sensitizer 3,4,3-LI(1,2-HOPO), with a log β 110 = 20.4 ± 0.2 value. In addition, the optical and solution thermodynamic features of these Am III complexes, combined with density functional theory calculations, were used to probe the influence of electronic structure on coordination properties across the f-element series and to gain insight into ligand field effects.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Advances in vat photopolymerization: early-career researchers shine light on a path forward

Vat photopolymerization (VP) has emerged as a promising additive manufacturing technique to allow rapid light-based fabrication of 3D objects from a liquid resin. Research in the field of vat photopolymerization spans across multiple disciplines from engineering and materials science to applied chemistry and physics. This perspective brings together early-career researchers from various disciplines in academia and national laboratories around the world to summarize the most recent advancements with special emphasis on the research highlighted as part of the Gordon Research Conference (GRC) 2024 meeting on Additive Manufacturing of Soft Materials. We provide an outlook on next-generation polymer processing methods from synthesis of novel materials to multimodality manufacturing and performance engineering. Further, this article combines the ideas of many of these junior researchers to present a vision for the future of the field by highlighting the challenges and opportunities that lie ahead.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Lasers will shine in future warfare

High-power radio and microwave beams join cost-effective, solid-state lasers on US military’s horizon.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Strong evidence that the galactic bulge is shining in gamma rays

There is growing evidence that the Galactic Center Excess identified in the Fermi-LAT gamma-ray data arises from a population of faint astrophysical sources. We provide compelling supporting evidence by showing that the morphology of the excess traces the stellar over-density of the Galactic bulge. By adopting a template of the bulge stars obtained from a triaxial 3D fit to the diffuse near-infrared emission, we show that it is detected at high significance. The significance deteriorates when either the position or the orientation of the template is artificially shifted, supporting the correlation of the gamma-ray data with the Galactic bulge. In deriving these results, we have used more sophisticated templates at low-latitudes for the Fermi bubbles compared to previous work and the three-dimensional Inverse Compton (IC) maps recently released by the GALPROP team. Our results provide strong constraints on Millisecond Pulsar (MSP) formation scenarios proposed to explain the excess. We find that an admixture formation scenario, in which some of the relevant binaries are primordial and the rest are formed dynamically, is preferred over a primordial-only formation scenario at 7.6σ confidence level. Our detailed morphological analysis also disfavors models of the disrupted globular clusters scenario that predict a spherically symmetric distribution of MSPs in the Galactic bulge. For the first time, we report evidence of a high energy tail in the nuclear bulge spectrum that could be the result of IC emission from electrons and positrons injected by a population of MSPs and star formation activity from the same site.

79 ASTRONOMY AND ASTROPHYSICS↗

SAX J1808.4$-$3658, an accreting millisecond pulsar shining in gamma rays?

We report the detection of a possible gamma-ray counterpart of the accreting millisec- ond pulsar SAXJ1808.4–3658. The analysis of ~6 years of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (Fermi-LAT) within a re- gion of 15° radius around the position of the pulsar reveals a point gamma-ray source detected at a significance of ~6σ (Test Statistic TS = 32), with position compatible with that of SAXJ1808.4–3658 within 95% Confidence Level. The energy flux in the energy range between 0.6 GeV and 10 GeV amounts to (2.1 ± 0.5) × 10 -12 erg cm -2 s -1 and the spectrum is well-represented by a power-law function with photon index 2.1±0.1. We searched for significant variation of the flux at the spin frequency of the pulsar and for orbital modulation, taking into account the trials due to the uncertain- ties in the position, the orbital motion of the pulsar and the intrinsic evolution of the pulsar spin. No significant deviation from a constant flux at any time scale was found, preventing a firm identification via time variability. Nonetheless, the association of the LAT source as the gamma-ray counterpart of SAXJ1808.4–3658 would match the emission expected from the millisecond pulsar, if it switches on as a rotation-powered source during X-ray quiescence.

79 ASTRONOMY AND ASTROPHYSICS↗