Science

It’s easy to take that hulking great white beast of a machine in our kitchens for granted, but for the 1.3 billion people in the world who are living without electricity, a working refrigerator is not an option. So a team of students in Canada has invented a cooling device that not only works without any electricity whatsoever, it’s also cheap and portable, making it ideal for those in remote and rural areas who struggle to keep their produce fresh.

"We thought it would be good to decrease the amount of food waste in the world, and we came up with this design because it's easy to build and the materials are relatively cheap," one of the students, Michelle Zhou from the University of Calgary, told CBC News.

Dubbed the WindChill Food Preservation Unit, the device connects an air tube to an evaporation chamber, which connects to a sealed refrigeration chamber that looks a lot like an esky, the contents of which are cooled through the process of evaporative cooling.

A tiny bug is threatening your morning orange juice.

In Florida, the Asian citrus psyllid, an aphid-size creature that feeds on the stems and leaves of citrus trees, cost the juice business $3.6 billion between 2006 and 2012. The real damage from “citrus greening” comes from bacteria spread by the bug, which causes leaves to turn yellow and kills the tree in a few years.

Researchers are looking into new ways to combat the pests, and one project focuses on sound rather than pesticides to disrupt the insects’ mating habits.

“We’re trying hard to cut down on use of pesticides in orange groves, partly because we are worried they’ll build up resistance to pesticides, and that will make things even worse,” said Richard Mankin, a research entomologist with the U.S. Department of Agriculture. He presented findings on acoustic disruption at the meeting of the American Acoustical Society this week in Jacksonville.

When a male psyllid wants to mate, he alerts a female by sitting on a leaf and buzzing his wings to send vibrations along leaves and branches. To disrupt that activity, the researchers created a device containing a piezoelectric buzzer and a microphone wired to a microcontroller.