(Phys.org) —Artifacts from the Middle Stone Age, which lasted from about 200,000 to 50,000 years ago, provide us with the earliest glimpses of modern human art and culture. Previously, scientists thought an increase in ...
Two years ago, Martin Rinard's group at MIT's Computer Science and Artificial Intelligence Laboratory proposed a surprisingly simple way to make some computer procedures more efficient: Just skip a bunch of steps. Although ...
Computer Sciences
May 23, 2012
16
0
It is almost night on the island of Puerto Rico. Astronomer Joanna Rankin raises her head toward the sky. A few of the brightest stars shine through blue cracks in a ragged dome of gray clouds. To her back, a jungle throbs ...
Astronomy
Dec 1, 2011
3
0
(PhysOrg.com) -- Just as photons are bundles of light energy, plasmons are energy packets of plasma oscillations—oscillations of the electron density in a solid body, which are known as surface plasmons when occurring ...
Optics & Photonics
Jan 27, 2011
3
0
A perforation is a small hole in a thin material or web. There is usually more than one perforation in an organized fashion, where all of the holes are called a perforation. The process of creating perforations is called perforating, which involves puncturing the workpiece with a tool.
Perforations are usually used to allow easy separation of two sections of the material, such as allowing paper to be torn easily along the line. Packaging with perforations in paperboard or plastic film is easy for consumers to open. Other purposes include filtrating fluids, sound deadening, allowing light or fluids to pass through, and to create an aesthetic design.
Various applications include packaging films (to allow the contents to breathe), medical films, micro perforated plate and sound and vapor barriers.
This text uses material from Wikipedia, licensed under CC BY-SA
