Researchers at the University of Michigan have brought a new method into the sound-dampening fold, demonstrating an origami lattice prototype that can potentially reduce acoustic noise on roadways. The technique allows researchers to selectively dampen noise at various frequencies by adjusting the distance between noise-diffusing elements. They report their work this week in the Journal of Applied Physics.
Like a tuning fork struck with a mallet, tiny gold nanodisks can be made to vibrate at resonant frequencies when struck by light. In new research this week, Rice University chemist Stephan Link and colleagues showed how to selectively alter those vibrational frequencies by gathering different-sized nanodisks into groups.
Scientists have reported the first dive depths for Gervais' and True's beaked whales, two of the least known beaked whale species known as mesoplodonts. The study is also the first to use a towed linear hydrophone array to document dive depths for beaked whales, and researchers say it's a promising method to obtain dive depths for other beaked whale species.
Many asymmetric absorbers are currently based on a single-port system, where sound enters one side and is absorbed before a rigid wall. In this design, however, light and air are unable to pass through the system. But new research shows that asymmetric absorption can be realized within a straight transparent waveguide. The waveguide allows light transmission and air flow through the absorber, and is described this week in Applied Physics Letters.
Researchers at the University of Houston were studying the nonlinear transmission of light through an aqueous suspension of gold nanoparticles when they noticed something unexpected. A pulse laser appeared to have forced the movement of a stream of liquid in a glass laboratory cuvette. Their observation led to a new optofulidics principle, explained in a paper published Sept. 27 in the journal Science Advances.
A murmuration of starlings. The phrase reads like something from literature or the title of an arthouse film. In fact, it is meant to describe the phenomenon that results when hundreds, sometimes thousands, of these birds fly in swooping, intricately coordinated patterns through the sky.
Like some bats and marine mammals, people can develop expert echolocation skills, in which they produce a clicking sound with their mouths and listen to the reflected sound waves to 'see' their surroundings. A new study published in PLOS Computational Biology provides the first in-depth analysis of the mouth clicks used in human echolocation.
Computer vision and sound experts at the University of Surrey have demonstrated 'Media Device Orchestration' -- an innovative home audio concept which enables users to enjoy immersive audio experiences by using all available devices in a typical living room.
Sheep, giant pandas, mouse lemurs, and fur seals all have something in common when it comes to communication. All of them produce calls with rapid, vibrato-like fundamental frequency modulation -- commonly known as bleats or trills. Now, researchers reporting in Current Biology think they know why that call feature has arisen multiple times over the course of evolution: it improves the ability of listeners to detect call components that provide important identifying information about a caller.
A powerful shockwave from the H.L. Hunley's own weapon killed the crew of the Confederate combat submarine as it sunk a Union ship. This finding comes from a four-year research project that involved repeatedly setting blasts near a scale model, shooting authentic weapons at historically accurate iron plate and many calculations on human respiration and the transmission of blast energy by Rachel Lance, a 2016 Ph.D. graduate of Duke Engineering.