rooftops

For years, city officials in Houston fought against those giant inflatable gorillas, placed on rooftops for advertising.

The city passed a law banning them, which was overturned in federal court. When an inflatable gorilla deflated on the roof of a Houston shopping center Thursday, it landed on some lights and set the shopping center on fire.

Solar cells could soon be produced more cheaply using nanoparticle "inks" that allow them to be printed like newspaper or painted onto the sides of buildings or rooftops to absorb electricity-producing sunlight.

Researchers apply the nanoparticle "inks" as a spray on the solar cells. Brian Korgel, a University of Texas at Austin chemical engineer, is hoping to [...]