We Continue the Work of Those
Who Were the First.

  • Electrotechnics
  • Electrical Engineering
  • Light & Lighting
  • Power Engineering
  • Transportation
  • Automation
  • Communication
  • Smart Buildings
  • Industry
  • Innovation

Current issue

ELEKTRO 7/2018 was released on June 27th 2018. Its digital version will be available on July 27th 2018.

Topic: Cables, conductors and cable engineering; Tools, equipment and accessories for work with cables

Main Article
Parametrization of circuit models of Li-accumulators for electromobility
Smart Cities (part 3 – volume 1)

SVĚTLO (Light) 4/2018 was released on July 30th 2018. Its digital version will be available on August 31th 2018.

Refreshing our memory
Eccentric luminaires of René Roubíček from the years1965 till 1977
Bases of photometry – 1st part
Great personage of Czech science of times after Battle at Bílá hora: doctor, naturalist, philosopher and physicist Jan Marek Marci from Kronland

Optical radiation effects and use
The light and circadian rhythms

Weird material shrinks when warm

14.10.2015 | UCONN | today.uconn.edu

Most materials swell when they warm, and shrink when they cool. But UConn physicist Jason Hancock has been investigating a substance that responds in reverse: it shrinks when it warms.

Although thermal expansion, and the cracking and warping that often result, are an everyday occurrence - in buildings, bridges, electronics, and almost anything else exposed to wide temperature swings - physicists have trouble explaining why solids behave that way.

New material shrinks when warm

Research by Hancock and his colleagues into scandium trifluoride, a material that has negative thermal expansion, recently published in Physical Review B, may lead to a better understanding of why materials change volume with temperature at all, with potential applications such as more durable electronics.

The classical way to think about solids like glass, metal, and rock imagines them made of atoms hooked together by springs. The springs stretch and flex in response to heat. But because each spring, when it expands, puts pressure on its neighboring springs - and all those neighboring springs expand the same amount and exert the same pressure on the first spring and all their own neighboring springs - the forces they exert on each other should be symmetrical, and the material should neither expand nor contract.

Read more at UCONN

Image Credit: UCONN

-jk-