Upconverting nanoparticle micro-lightbulbs designed for deep tissue optical stimulation and imaging
Not Available
77 NANOSCIENCE AND NANOTECHNOLOGY↗
SEARCH · Engineering Papers
Results for “LIGHTBULB”
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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How to Make a Lightbulb That Is a Million Times Smaller Than an Ant [Slides]
Abstract not provided.
36 MATERIALS SCIENCE↗
Helium reionization simulations. I. Modeling quasars as radiation sources
We introduce a new project to understand helium reionization using fully coupled N-body, hydrodynamics, and radiative transfer simulations. This project aims to capture correctly the thermal history of the intergalactic medium as a result of reionization and make predictions about the Lyα forest and baryon temperature–density relation. The dominant sources of radiation for this transition are quasars, so modeling the source population accurately is very important for making reliable predictions. In this first paper, we present a new method for populating dark matter halos with quasars. Our set of quasar models includes two different light curves, a lightbulb (simple on/off) and symmetric exponential model, and luminosity-dependent quasar lifetimes. Our method self-consistently reproduces an input quasar luminosity function given a halo catalog from an N-body simulation, and propagates quasars through the merger history of halo hosts. After calibrating quasar clustering using measurements from the Baryon Oscillation Spectroscopic Survey, we find that the characteristic mass of quasar hosts is M{sub h}∼2.5×10{sup 12} h{sup −1} M{sub ⊙} for the lightbulb model, and M{sub h}∼2.3×10{sup 12} h{sup −1} M{sub ⊙} for the exponential model. In the latter model, the peak quasar luminosity for a given halo mass is larger than that in the former, typically by a factor of 1.5–2. The effective lifetime for quasars in the lightbulb model is 59 Myr, and in the exponential case, the effective time constant is about 15 Myr. We include semi-analytic calculations of helium reionization, and discuss how to include these quasars as sources of ionizing radiation for full hydrodynamics with radiative transfer simulations in order to study helium reionization.
79 ASTRONOMY AND ASTROPHYSICS↗
Fast flavor instability in hypermassive neutron star disk outflows
Here, we examine the effect of neutrino flavor transformation by the fast flavor instability (FFI) on long-term mass ejection from accretion disks formed after neutron star mergers. Neutrino emission and absorption in the disk set the composition of the disk ejecta, which subsequently undergoes r-process nucleosynthesis upon expansion and cooling. Here we perform 28 time-dependent, axisymmetric, viscous-hydrodynamic simulations of accretion disks around hypermassive neutron stars (HMNSs) of variable lifetime, using a 3-species neutrino leakage scheme for emission and an annular-lightbulb scheme for absorption. We include neutrino flavor transformation due the FFI in a parametric way, by modifying the absorbed neutrino fluxes and temperatures, allowing for flavor mixing at various levels of flavor equilibration, and also in a way that aims to respect the lepton-number preserving symmetry of the neutrino self-interaction Hamiltonian. We find that for a promptly-formed black hole (BH), the FFI lowers the average electron fraction of the disk outflow due to a decrease in neutrino absorption, driven primarily by a drop in electron neutrino/antineutrino flux upon flavor mixing. For a long-lived HMNS, the disk emits more heavy lepton neutrinos and reabsorbs more electron neutrinos than for a BH, with a smaller drop in flux compensated by a higher neutrino temperature upon flavor mixing. The resulting outflow has a broader electron fraction distribution, a more proton-rich peak, and undergoes stronger radiative driving. Disks with intermediate HMNS lifetimes show results that fall in between these two limits. In most cases, the impact of the FFI on the outflow is moderate, with changes in mass ejection, average velocity, and average electron fraction of order ~10%, and changes in the lanthanide/actinide mass fraction of up to a factor ~2.
79 ASTRONOMY AND ASTROPHYSICS↗
Energy 101: Lumens
Description: In this edition of Energy 101, we talk about Lumens. When you're shopping for light bulbs, compare lumens to be sure you';re getting the amount of light, or level of brightness, you want.
14 SOLAR ENERGY↗
EBR-I Tour
Sixty years ago, the first light bulb to be lit with nuclear energy got its juice right here in Idaho. Here's a virtual tour of the place where it all happened. To learn more visit http://www.inl.gov/ebr.
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗