There’s more to the snap, crackle and pop of Rice Krispies than meets the ear. A recent study by San Diego State University civil engineering professor Julio Valdes used the breakfast cereal to discover a new phenomenon in materials science: Highly porous, brittle materials can deform in different ways depending on compaction velocity. Put another way, the speed at which one crushes a tube full of cereal, for example, can have implications for manufacturing or even assessing the safety of snow after an avalanche.
Valdes and a grad student placed Rice Krispies in an acrylic tube. As a piston crushed the cereal, the experimenter could see the material being compacted, with the piston depressing at different velocities.
Depending on the velocity, they could see three different types of deformation in the cereal. At very low velocities, the cereal exhibited an erratic deformation pattern, crushing at various points within the tube. At very high velocities, it all crushed down fairly uniformly. And at in-between velocities, the researchers saw a rising band in the tube, indicating where the material was being crushed, or deformed. Results of the study were published in the journal “Nature Physics”.
And in case you’re curious, the researchers informally repeated the experiment using Cocoa Puffs and Cocoa Krispies and found the same results. sdsu.edu
Tech device monitors guide dogs’ health
Researchers at N.C. State have developed a device that allows people who are blind to monitor their guide dogs, in order to keep tabs on the health and well-being of their canine companions. The device monitors a dog’s breathing and heart rate and shares the information with the dog’s handler.
The research team previously developed monitoring technologies that are incorporated into a lightweight harness that can be worn by rescue or service dogs.
The researchers developed a specialized handle that attaches to a guide dog’s harness; the handle is equipped with two vibrating motors. One motor, near the handle thumb, vibrates or beats in time with the dog’s heart rate. The second motor in the handle is embedded near the handler’s pinky finger, and vibrates in synch with the dog’s breathing.
A paper on this technology was presented last week at the International Congress on Animal Computer Interaction, in Johor, Malaysia. The lead author is Sean Mealin, a Ph.D. student at N.C. State who is blind and who works with his own guide dog. ncsu.edu
Study: Most top websites track, leak user data
Browsing the Internet feels like a solitary activity but, as a new study in the International Journal of Communication reveals, you may be surprised by just how many companies are observing.
Tim Libert, a doctoral student at the University of Pennsylvania, analyzed the Alexa top 1 million websites, finding that 88 percent leak user data to third parties – sites that would be unfamiliar to most users.
"There’s some suggestion that it’s anonymous data,” said Libert, “but when you have big data sets that can be combined with other big data sets, you can be identified pretty easily.”
Sites that leak user data contact an average of nine external domains, indicating that the activity of a single person visiting a single site may be tracked my multiple entities.
By tracing the unintended disclosure of personal browsing histories on the web, Libert discovered that a handful of U.S. companies receive the bulk of user data worldwide, led by Google, which tracked users on nearly 80 percent of the websites studied. Other top followers on the sites studied include Facebook (32 percent), Twitter (18 percent), ComScore (12 percent), Amazon (12 percent) and AppNexus (12 percent).
While this monitoring of your behavior doesn't signal nefarious activity or a security breach, it does increase the risk of one taking place. Libert: “If your data is being sent to several companies, that creates new potential points of failure where your data could be hacked or leaked,” Libert said. asc.upenn.edu