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January 24, 2008

Making Pitt Work: Chemistry demonstrator Dave D'Emilio

Pitt’s senior administration grabs most of the headlines. The faculty here get noticed when they bring in research dollars, win teaching awards or publish in their fields.

But behind the scenes, University staff, some 6,500 strong across five campuses, often toil in jobs ranging from the mundane to the esoteric.

This is one in an occasional series profiling University staff, providing a glimpse of some of the less recognized employees whose primary business is making Pitt work.

When Dave D’Emilio takes his place in the front of a lecture hall, professors step aside and students sit up just a bit straighter in anticipation. The arrival of Pitt’s chemistry demonstrator in the classroom means there’s soon going to be something interesting to see.

On a recent morning, D’Emilio took to the front of chemistry professor Leonard Kogut’s class in Chevron Science Center to show how and why a magnesium fire can’t be extinguished using water or even carbon dioxide fire extinguishers.

Clad in a white lab coat accessorized by sneakers and a baseball cap in addition to the requisite safety gloves and glasses, D’Emilio lit a piece of magnesium ribbon, then placed it in an indentation in a block of dry ice — frozen carbon dioxide. He placed another block of dry ice atop the burning metal, quickly increasing the intensity of the burn. As he demonstrated how magnesium can tear the oxygen molecules from water or carbon dioxide and use them to aid in combustion, he accompanied the explosions and flying sparks with details from news stories in which firefighters were faced with such challenges. Then he showed how the fire can be put out with magnesium oxide or ordinary dry sand. Beyond being visually impressive and edifying for a new chemistry student, D’Emilio knows that this particular demonstration imparts what could be practical and perhaps lifesaving information useful to current or future paramedics, nurses or volunteer firefighters who may be among the students in his audiences.

Not every demonstration is so dramatic, D’Emilio admitted, but they do make an impression, he said, adding that he especially likes to put the material into the context of daily life for his listeners.

Kogut, who typically schedules D’Emilio for one or two in-class demonstrations each week, said, “It’s a great benefit to have. The students like him.”

Chemistry professor David Pratt agreed. He frequently turns over a portion of his class time to D’Emilio to help reinforce the basic concepts discussed in class.

Pratt contends that although today’s students are every bit as intelligent as their predecessors, they are falling behind in their knowledge of practical chemistry and exposure to hands-on lab experience as high schools increasingly eliminate labs, either for cost or safety reasons. “Doing demonstrations like this is absolutely essential to students’ education,” he said, adding that the demonstrations D’Emilio gives help students make a connection to the lecture material. “The crucial thing is to keep the class engaged,” Pratt said. The more engaged they are in class, the more enthusiastic they become about the course work, he said.

D’Emilio, himself a visual learner, said, “The more you can show them visibly, it helps,” especially to reinforce textbook and lecture material for those who have little lab experience. “Seeing the equations — to a new learner, they mean nothing,” he said. While his demonstrations reflect concepts that are expressed in formulas and equations, “I try to make things as visual as possible and as non-mathematically-threatening as I can,” he said.

Student evaluations of the demonstrations are “almost always very positive,” and it’s not just about the dramatic visuals such as the fireballs he creates to demonstrate principles of stoichiometry. “They all prefer to have demonstrations to break up the lecture,” D’Emilio said.

In spite of the demonstrator’s undisputed value in the classroom, jobs like his are rare. “It would be nice if every school could have the kind of equipment and personnel devoted to showing these large-scale demonstrations,” he said, noting that only a fraction of even the largest universities have demonstrators.

D’Emilio noted that professors are appreciative of his services “because they only have so much time.” He gathers the materials, does the demonstrations, then packs up the equipment and materials and returns them to their proper places. “It’s more convenient to have me do it,” he said.

Repetition works to D’Emilio’s advantage in making the demonstrations proceed as they should. While professors who do a particular demonstration only once or twice a year may stand a better chance of forgetting small details that help the lesson go smoothly, D’Emilio gets plenty of practice doing basic chemistry demonstrations for multiple classes. “There’s some he’s a little better at than I am,” Kogut admitted. D’Emilio also will prepare demonstration materials for professors who prefer to be do-it-yourselfers, collecting the requisite equipment and supplies on a rolling metal cart that he delivers to the classroom at the appropriate time. Most demonstrations are in Chevron Science Center or Thaw Hall; occasionally he has to push one of the carts to Alumni Hall and back — about a quarter-mile round trip.

D’Emilio has 12-15 class periods each week where he considers himself a regular visitor. In a typical week, he will do 50-70 demonstrations — nearly all for freshman chemistry classes — conducting perhaps five-10 different experiments in a given class period. The only time he gets a breather is when professors are giving major tests. Otherwise, his calendar is kept full by 15-20 instructors and some 50 class periods per week in which he could be called upon to demonstrate or prepare a demonstration.

D’Emilio’s home base is a narrow office tucked beneath the main stairway in Chevron Science Center. Metal carts with demonstrations in various stages of preparation are lined up like grocery carts in a checkout line. Tanks of various gases and foam chests used to transport dry ice are tucked into nooks and crannies. Models of molecules made from colorful balls and rods lie in a jumble atop a row of cabinets that hold demonstration materials and equipment.

Close at hand are myriad odds and ends that can be used to demonstrate scientific principles on a moment’s notice. An empty soda pop bottle isn’t so empty — it’s filled with air. And when its label is removed and a bit of alcohol is sprayed inside, it becomes a bottle rocket that offers insight into how combustion chambers work. Lighting a candle beneath a pancake turner, D’Emilio can show by the ring-shaped carbon pattern left on the metal that flames are hollow. These and many more simple object lessons in waiting are all within easy reach.

Most important is the white board on which D’Emilio keeps his weekly calendar. Each week, professors submit their requests for demonstrations. D’Emilio marks them on the board, noting the professor, the date, time and experiments requested. He prepares as much as he can ahead of time to allow for the last-minute changes or that invariably come.

In addition to showing about 1,000 Pitt students each term the basics of how chemistry works, he also offers demonstrations for younger students. When the University is not in session, the chemistry department occasionally invites middle or high school students to campus for demonstrations of scientific principles. In addition, D’Emilio does occasional outreach presentations at the Carnegie Science Center or in conjunction with former Pitt colleague Garry Warnock, who now leads Carnegie Mellon University’s chemistry and physics outreach van team.

D’Emilio’s path to the University was a meandering one. A child of the Sputnik era, he enjoyed science and has accumulated a broad scientific background over the years. He has done cancer research, scientific equipment sales and taught chemistry at a technical school. Drafted into the Vietnam War, he later spent several decades in the Army reserve. The military was encouraging officers who had science degrees to get back into the classroom. “I thought it was a good idea,” he said, but after taking graduate classes and student teaching, he decided that teaching full-time wasn’t for him.

“I never thought I’d be back in chemistry,” he admitted, but when he saw the demonstrator’s position open in 1991, he jumped at it. While his position admittedly involves teaching, “It’s a lot more enjoyable that I don’t have to give tests,” he said. “The students like me a lot more.”

Although some days are tiring due to the physical work, there’s less paperwork. Plus, teachers in an ordinary classroom can’t regularly offer special effects. D’Emilio can and, in doing so, keeps the attention of kids of all ages.

“It is more fun to be a sort of Mr. Wizard,” he said.

It was Pitt’s chemistry van that brought D’Emilio to the University. When he first arrived, he worked with chemistry professor Henry Bent, who started a van program to take science on the road to local elementary and middle schools. “When I first took the job, I didn’t expect to be in front of the classroom,” D’Emilio said, although he has no fear of public speaking, coming, as he says, from “a family of talkers” that includes several teachers. Initially, he wasn’t even the principal speaker in the 90-minute science road shows, although he eventually became the lone presenter in 1997, continuing until 2001 when funding dried up and Pitt’s van program ended. D’Emilio said he’s lost track of exactly how many presentations he’s done, but admits he can present by heart many of the regular demonstrations on general topics such as “atoms exist,” or “electrons move,” or can easily accommodate an impromptu request or last-minute addition from a professor.

Among his favorite demonstrations is one in which balloons are filled with different gases and ignited — a lesson in balancing equations. The size of the fireball each gas creates when it burns is dependent on the number of oxygen atoms the gas combines with during combustion.

His job isn’t without its hazards. “I have ended up inside a fireball,” he admitted. During the balancing equations demonstration, the balloons are tethered overhead and lit with a torch attached to a three-foot pole.But in one demonstration a gas-filled balloon sagged and a cross draft blew the fireball his way. D’Emilio got singed.

“Everything is potentially dangerous,” he said. “You can have an accident with the simplest, safest thing.” He notes that he takes precautions, practices a lot and always keeps a fire extinguisher handy, in addition to wearing appropriate safety gear.

“I want to model to the students. Getting people to wear goggles and masks in the lab is hard. Nobody thinks they’re going to have an accident. If students don’t see you wearing them, why should they?”

When demonstrations go awry for whatever reason, they provide teaching opportunities as well. “Kids get a kick out of things when they don’t work,” he said. And glitches are inevitable. “Sooner or later, something doesn’t work,” D’Emilio said, recounting times when seemingly small details — a bad cork or a leak in tubing — made demonstrations fail. “It’s a learning opportunity to explain why things go wrong. … Usually there is a chemical or physical reason,” he said, happy for the chance to explain.

—Kimberly K. Barlow

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