Potatoes and propane are a combustible duo for these YSU students

Students learn that too much fuel can spoil a quality potato launching.
YOUNGSTOWN -- Take a potato, several feet of PVC pipe and some propane, add some freshmen engineering students at Youngstown State University, and what do you get?
A big bang, a potato that soars up to 150 yards, and a fun lesson in the dynamics of combustion.
The potato cannon, or "spud gun,'' was among the numerous exhibits Thursday at the Engineering Careers and Student Design Displays in the lobby of Moser Hall, home to the William Rayen College of Engineering and Technology. The annual event -- which included a 150-pound concrete canoe and robotics and electronics exhibits -- is held to show off what the college has to offer and allow students to display their senior projects.
Mechanical Engineering Professor Hazel Pierson said she introduces to freshmen various concepts of engineering that are all around them.
The spud gun teaches them about the upper and lower limits of combustion and the percentage of combustion energy that is converted into "potato kinetic energy.''
A potato is placed in the 2-inch diameter pipe and syringes of propane are pushed into a combustion chamber at the end of the pipe. When a spark is created in the chamber, combustion occurs, the gas expands and the potato is launched.
"I'm a vegetarian, so I have nothing against potatoes,'' Pierson said. "But they sure are fun to shoot.''
Students learn that if they use too much or too little fuel, or propane, combustion will not occur. The same thing occurs when a car's carburetor gets flooded with gas or gets little or no gas at all, Pierson said.
Devices and improvements
Outside the hall, students Kari Utterback, Travis Moore and Ryan Mercer were showing off their senior project: a device, attached to the back of a tractor, that spreads and secures protective plastic sheeting over rows of newly planted sweet corn.
They didn't invent it, but they did make it better, said Utterback, of Jefferson, Ohio.
As the tractor moves, discs dig out rows of dirt, the plastic is pulled off a large roll and is pushed into the dirt by wheels. Another set of discs pushes dirt atop the edges of the plastic, securing it over two rows of corn at a time, she said.
Mercer's family, who own Catalpa Grove Farms in Columbiana County, came up with the idea for the project and covered the $1,799 cost to create the device, Utterback said.
"It's basically a redesign to make it a more efficient machine,'' she said.
Asked whether the team had received a grade, Utterback said, "Grades will come later. From what we've heard, they [the professors] are impressed.''
Next to the tractor was a moon rover designed by Julia Navoyosky, Nick Mastramico, Bill Hiznay and Mike Keffer. The vehicle was made of a collapsible steel frame that can be folded to fit into a 4-foot-by-4-foot space. Their creation was recently entered in the annual moon rover competition at the U.S. Space & amp; Rocket Center in Huntsville, Ala.
"This is a great opportunity for our students and the public to learn of the opportunities here at Youngstown State University,'' said Jalal Jalali, professor and chair of the Department of Electrical and Computer Engineering. "This is the result of 14 to 16 weeks of hard work."