I can hire one half of the working class to kill the other half.~Jay Gould

VSEPR

by: hhex65

Fri Apr 27, 2012 at 08:00:00 AM MST

Check out the new tab Real Molecules in the Molecule Shapes or Molecule Shapes: Basics sims. By clicking on the link, you can compare the VSEPR (Valence Shell Electron Pair Repulsion) model to real molecules.

Valence shell electron pair repulsion (VSEPR) rules are a model in chemistry used to predict the shape of individual molecules based upon the extent of electron-pair electrostatic repulsion.

The premise of VSEPR is that the valence electron pairs surrounding an atom mutually repel each other, and will therefore adopt an arrangement that minimizes this repulsion, thus determining the molecular geometry. The number of electron pairs surrounding an atom, both bonding and nonbonding, is called its steric number.

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metamaterial

by: hhex65

Thu Apr 26, 2012 at 09:00:00 AM MST

Scientists in England and Spain have constructed what may be the first practical metamaterial that manipulates visible light.

Metamaterials are engineered to interact with light in unnatural ways. Most metamaterials are constructed of repeating features that interact with electromagnetic waves to give the material both a negative electric permittivity and a negative magnetic permeability.

Electric permittivity is a measure of how resistant a material is to electric fields forming within it; the higher the permittivity, the smaller the electric field that forms per unit of charge.

Magnetic permeability is similar, but the higher a material's permeability is, the larger the magnetic field it can support.

Materials with both negative permittivity and permeability have a negative index of refraction, so they bend light the wrong way.
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CES: Award Winning Exhibit Designs Send the right Marketing Message

by: hhex65

Wed Apr 25, 2012 at 08:00:00 AM MST

CES was strong in the eureka tech this year whilst the pure imagination zone helped launch attendees through the air across 10,000 square feet. Innovations and emerging attractions captured the will of a diverse audience. The Sands Convention was a central theme in the Salt Bilge keynote. The keynote was a look back at the 2006 International CES where Blu-ray Disc was first conspicuous.

A display prototype whose screen can retain many of the other manufacturers' specs provided the edge in the standards competition between HD innovations and hardcore HD movies. Even after several months without electricity Hillcrest Labs won the "Best Of Making It" with a television to be controlled with natural gestures.

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