Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Microstructure. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Composite batteries: a simple yet universal approach to 3D printable lithium-ion battery electrodes

Abstract: Printable energy storage is anticipated to facilitate innovation in the manufacture of flexible electronics and soft robotics by enabling direct integration of a power source into a system during the fabrication process. To this end, we have established a universal approach to develop 3D printable, free-standing electrodes with an embedded current collector for high-performance Li-ion batteries. This simple approach utilizes a well-dispersed mixture of active material, carbon nanofibers, and polymer to make castable or printable electrode inks. By tuning the ratios of these components in a series of inks, we have observed the effect each parameter had on the resulting rheological, electrochemical, and mechanical properties. Once properly balanced, free-standing electrodes of three common Li-ion battery active materials (i.e., lithium titanate (Li4Ti5O12), lithium iron phosphate (LiFePO4), and lithium cobalt oxide (LiCoO2)) were prepared, each demonstrating excellent cyclability and rate capability. Finally, electrodes were successfully patterned using a direct ink writing method, and a fully-printed, working electrode plus separator electrode assembly were developed.

Anderson light localization in biological nanostructures of native silk

Abstract: Light in biological media is known as freely diffusing because interference is negligible. Here, we show Anderson light localization in quasi-two-dimensional protein nanostructures produced by silkworms (Bombyx mori). For transmission channels in native silk, the light flux is governed by a few localized modes. Relative spatial fluctuations in transmission quantities are proximal to the Anderson regime. The sizes of passive cavities (smaller than a single fibre) and the statistics of modes (decomposed from excitation at the gain–loss equilibrium) differentiate silk from other diffusive structures sharing microscopic morphological similarity. Because the strong reflectivity from Anderson localization is combined with the high emissivity of the biomolecules in infra-red radiation, silk radiates heat more than it absorbs for passive cooling. This collective evidence explains how a silkworm designs a nanoarchitectured optical window of resonant tunnelling in the physically closed structures, while suppressing most of transmission in the visible spectrum and emitting thermal radiation. Light in biological media is known as freely diffusing because interference is negligible. Here, the authors demonstrate Anderson localization of light from quasi-two-dimensional nanostructures in silk fibres.

Self-Assembly of Emissive Nanocellulose/Quantum Dot Nanostructures for Chiral Fluorescent Materials.

Abstract: Chiral fluorescent materials with fluorescent nanoparticles assembled into a chiral structure represent a grand challenge. Here, we report self-assembled emissive needle-like nanostructures through...

Alpha/Beta Heat Treatment of a Titanium Alloy with a Nonuniform Microstructure

Abstract: The effect of alpha/beta solution temperature and cooling rate on the evolution of microstructure during the heat treatment of Ti-6Al-2Sn-4Zr-2Mo-0.1Si (Ti6242Si) with a partially spheroidized starting microstructure of equiaxed + remnant lamellar alpha was established. Experiments comprising induction heating to a peak temperature of 971 °C or 982 °C followed by cooling at a rate of 11 °C/min or 42 °C/min revealed that the volume fraction of the equiaxed alpha grew much more rapidly than the lamellar constituent. These results were explained semiquantitatively using simple diffusion analyses of the growth of either spherical or elliptical particles, taking into account the soft impingement of the concentration fields. Despite the much lower diffusivity of molybdenum, which appears to control the growth of primary alpha in Ti6242Si, the similarity of the overall kinetics compared to those measured previously for Ti-6Al-4V was explained on the basis of the higher supersaturations developed during cooldown in the present alloy.

Degenerate nonlinear absorption and optical power limiting properties of asymmetrically substituted stilbenoid chromophores

Abstract: Two-photon absorption (2PA) spectra (650–1000 nm) of a series of model chromophores were measured via a newly developed nonlinear absorption spectral technique based on a single and powerful femtosecond white-light continuum beam. The experimental results suggested that when either an electron-donor or an electron-acceptor was attached to a trans-stilbene at a para-position, an enhancement in molecular two-photon absorptivity was observed in both cases, particularly in the 650–800 nm region. However, the push–pull chromophores with both the donor and acceptor groups showed larger overall two-photon absorption cross-sections within the studied spectral region as compared to their mono-substituted analogues. The combined results of the solvent effect and the 1H-NMR studies indicated that stronger acceptors produce a more efficient intramolecular charge transfer character upon excitation, leading to increased molecular two-photon responses in this model-compound set. A fairly good 2PA based optical power limiting behavior from one of the model chromophores is also demonstrated.