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Current issue

ELEKTRO 11/2016 was released on November 7th 2016. Its digital version will be available on December 1st 2016.

 

Topic: Switchboards and switchboard engineering; Rotating electrical machines and power electronics; Maintenance of EE

 

Main Article

Lithium traction batteries for electric mobility (part 1)

Printed edition of SVĚTLO (Light) 5/2016 was released on September 19th 2016. Its digital version will be available immediately.

 

Standards, regulations and recommendations

Regulation No 10/2016 (Prague building code) from the view of building lighting technology

 

Lighting installations

PROLICHT CZECH – supplier of lighting for new SAP offices

Hold up the light to see in work your work

Modern and saving LED lifting of swimming pool hall

Sound-proof metamaterial inspired by spider webs

12.09.2016 | Phys.org | www.phys.org

A team of researchers from Italy, France and the UK has designed an acoustic metamaterial (which is a material made of periodically repeating structures) influenced by the intricate spider web architecture of the golden silk orb-weaver, also called the Nephila spider.

By modeling different versions of the new spider-web-inspired acoustic metamaterial, the researchers demonstrated that the new design is more efficient at inhibiting low-frequency sound and is more easily tuned to different frequencies than other sound-controlling materials. Combined with the stiffening mechanical properties and the heterogeneity of spider silk, the tunable acoustic properties demonstrated here suggest that spider-web-inspired metamaterials could lead to a new class of applications for controlling vibrations. Possibilities include earthquake protection for suspended bridges and buildings, noise reduction, sub-wavelength imaging, and acoustic cloaking.

New acoustic metamaterial

The metamaterial is highly tunable because its geometry is defined by five parameters—which is more than traditional acoustic materials—and each of these parameters can be independently controlled to produce a vast number of designs that respond to different acoustic frequencies. The frequency range that is inhibited by these materials is called the band gap, and here the researchers showed that spider-web-inspired acoustic metamaterials can have wide band gaps, with large ranges of tunability.

Read more at Phys.org

Image Credit: M. Miniaci

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