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.

Nanostructured 3D Electrode Architectures for High‐Rate Li‐Ion Batteries

Abstract: By initially depositing a sub-10 nm-thick SnO2 film, the microstructural evolution that is often considered problematic can be utilized to form Sn nanoparticles on the surface of a 3D current collector for enhanced cycling stability. The work described here highlights a novel approach for the uniform deposition of Sn nanoparticles, which can be used to design electrodes with high capacities and high-rate capabilities.

Dynamic-coarsening behavior of an α/β titanium alloy

Abstract: The dynamic-coarsening behavior of Ti-6Al-4V with an equiaxed α microstructure was established via isothermal hot-compression testing of cylindrical samples cut from an ultra-fine-grain-size (UFG) billet. Compression experiments were conducted at 900 and 955 °C, strain rates between 10−4 and 1 s−1, and imposed true strains between 0 and 1.4. Following deformation, quantitative metallography revealed marked coarsening of the primary α particles at low strain rates (10−4 and 10−3 s−1). The dynamic-coarsening rate followed rn vs time kinetics, in which n was between 2 and 3, or behavior between those of bulk-diffusion and interface-reaction controlled. An examination of the temperature and strain-rate dependence of theoretical coarsening rates, however, strongly suggested that bulk diffusion (with n=3) was more important. The dynamic-coarsening behavior was also interpreted in the context of the observed plastic-flow behavior. At low strain rates, high values of the strain-rate sensitivity (m>0.5) and the overall shape of log stress-log strain rate plots indicated that the majority of the imposed strain was accommodated by grain-boundary sliding (gbs) and only a small amount via dislocation glide/climb processes. In addition, an analysis of the flow hardening that accompanied dynamic coarsening indicated that the flow stress varied approximately linearly with the α particle size, thus providing support for models based on gbs accommodation by dislocation activity in grain-mantle regions.

Impact localization in complex structures using laser-based time reversal

Abstract: This study presents a new impact localization technique that can pinpoint the location of an impact event within a complex structure using a time-reversal concept, surface-mounted piezoelectric tra...

Photolytic-interference-free, femtosecond two-photon fluorescence imaging of atomic hydrogen.

Abstract: We discuss photolytic-interference-free, high-repetition-rate imaging of reaction intermediates in flames and plasmas using femtosecond (fs) multiphoton excitation. The high peak power of fs pulses enables efficient nonlinear excitation, while the low energy nearly eliminates interfering single-photon photodissociation processes. We demonstrate proof-of-principle, interference-free, two-photon laser-induced fluorescence line imaging of atomic hydrogen in hydrocarbon flames and discuss the method’s implications for certain other atomic and molecular species.

Infant Visual Preferences: A Review and New Theoretical Treatment

Abstract: Publisher Summary This chapter focuses on the reason that determines infants' visual preferences at different ages and proposes a quantitative model of preferences based on linear systems techniques and test it against data from several well-known preference experiments The model's predictions agree quite well with observed preferences for a variety of stimuli The success of this model implies that infants' visual preferences are governed simply by a tendency to look at highly visible patterns This account of early preferential looking is thus consonant with the understanding of how the growth of basic sensory mechanisms affects visual perception during the first months of life Linear systems analysis is based on Fourier's theorem This powerful theorem implies that any two-dimensional, time-invariant visual stimulus can be exactly described by combining a set of more basic stimuli These basic stimuli are sine wave gratings A sine wave grating is a pattern of light and dark stripes whose intensity varies sinusoidally with position Sine wave gratings are specified by four parameters—spatial frequency, orientation, phase, and contrast Fourier's theorem implies then that even a complex, two-dimensional visual stimulus, such as the picture of a face, can be described exactly by the combination of a set of gratings of various frequencies, orientations, phases, and contrasts