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Thursday, July 19, 2012
Undergrads Research in Mentors' Labs
Text by Jean Florman
When Samantha Westerhof was exploring her college options, she visited five Big 10 universities.
While she felt the University of Iowa might be a perfect fit, it was a comment from College of Engineering director of admissions Jane Dorman that sealed the deal.
“She told me that engineering students at Iowa are encouraged to become involved in more than just engineering,” says Westerhof, who in addition to a stellar academic career, has participated in a social sorority, the Society of Women Engineers, and the student chapter of the American Institute of Chemical Engineers. And as if that weren’t enough, the chemical and biochemical engineering senior also has devoted much of her time since January 2011 to researching the fate and effect of a variety of commercially produced nanoparticles on the growth of poplar trees. The preliminary results have surprised and intrigued Jerald Schnoor, Allen S. Henry Chair in Engineering, professor of civil and environmental engineering and the director of the lab where Westerhof works.
Through years of research and real-world applications, Schnoor has demonstrated the ability of poplar trees to help clean up Superfund and other polluted sites by degrading organic pollutants and stabilizing some toxic metalloids like arsenic. His current nanomaterials research is funded by an Environmental Protection Agency/National Science Foundation joint program.
Westerhof heard about Schnoor’s research and decided it would be a good fit for her given her academic trajectory and environmental commitment.
“I’ve always been environmentally conscious and interested in issues of sustainability, and this process of phytoremediation by poplar trees really intrigued me,” says Westerhof, whose two grandfathers, two uncles, and mother are engineers. “I was ooking for a job and wanted something related to environmental issues, so I emailed Professor Schnoor to see if he had any openings in his lab. He emailed me right back and asked when I could meet with him.”
Schnoor gave Westerhof major responsibility for examining the impact of nanoparticles such as cerium oxide, iron oxide, and ilver on poplar trees. Often contained in sunscreens, cosmetics, and other household products, these metals can eventually find their way into the soil and runoff water. Poplar trees have proven to be superb “research subjects” because they grow quickly, can be examined in the lab or the natural world, and take up and store some chemicals.
Westerhof begins each experimental cycle by planting poplar cuttings in large plastic tubs, two dozen cuttings to a tub.
After three weeks, the foot-tall seedlings are exposed to various concentrations of elements. A week later, Westerhof cuts up he leaves and stems, dries them in an oven, and uses a mass pectrometer to determine concentrations of elements as low as one-part-per-trillion in each seedling. She and Schnoor agree that the preliminary results have been quite surprising.
“Dissolved silver nitrate kills the trees within 48 hours,” she says, “but every nanoparticle actually seems to have helped the plants.”
“The preliminary results are fascinating,” Schnoor agrees, “because it appears that at low concentrations, the particles actually stimulate the growth and transpiration of the plants.
Now we’re trying to understand the mechanism of this phytostimulation, which would be a major finding.”
Westerhof presented her findings at the 2011 American Institute of Chemical Engineers meetings where she won first place in the student environmental poster division. Although she says “there have been a few research hiccups” that required her to hange some protocols, she has come to love lab work.
“Professor Schnoor has given me a lot of freedom to work on my own,” she says, “and working in the lab has been a fantastic pportunity. Before, I never even considered graduate school.
Now I’m going to spend the summer applying to graduate schools. And of course Iowa is on that list.”
According to Sean Plenner, in Bill Eichinger’s lab you learn by doing—and sometimes that means you learn by failing.
Since spring semester of his sophomore year, Plenner has conducted research in an IIHRHydroscience & Engineering lab where he designed and built a simple, effective, and relatively inexpensive laser instrument that can measure river sediment deposition and scour patterns with millimeter precision.
Along the way, Plenner also co-authored two papers, presented a poster at the 2011 American Geophysical Union (AGU) national conference, and was mentored by the lab director, William D. Ashton Professor of Civil Engineering William Eichinger.
On the first day of Plenner’s sophomore civil engineering practice course, Eichinger briefly discussed his laser research. By the final day in the semester, Plenner was intrigued enough to ask his professor if he needed any help in the lab. Eichinger’s response: “When do you want to start?” Plenner jumped at the chance to do undergraduate research, and today, the graduating senior says working in the lab was transformative and fun. But it wasn’t easy.
“For quite a while, I didn’t know what to do or how to do it,” he says. “I wasn’t familiar with the lab equipment and really had no idea how to do research. But Professor Eichinger would rather have you try and fail than just tell you the answer. It was really hard, but he seemed to have confidence in me, so I kept pushing myself.”
“If I’d known the answers, I would have told him,” chuckles Eichinger, who believes students learn to be creative by doing the hard work of problem solving, “The key thing in engineering is to figure out why something doesn’t work as well as we hoped nd then improve it. With each iteration of the instrument, we learned to do it better.”
“Sean came up with clever, innovative ways to make the laser instrument faster, lighter, more accurate, and more capable,” Eichinger says. “When coupled with his data analysis software, the instrument is far more capable than anything I had envisioned when we began.”
The “candy-store” nature of the lab also enhanced the experience for a young engineer. “The labs in IIHR have every tool anyone could ever need,” Plenner says, “as well as the people to help me build the equipment. I’ve had a ton of fun working there.”
For his laser mapping instrument, Plenner developed analytic software capable of scanning underwater to create three dimensional topographic images. IIHR director and Edwin B. Green Chair in Hydraulics Larry Weber and research engineer Marian Muste have applied Plenner’s mapping device to study scour effects below a dam and around a bridge pier. Although private companies have built similar devices, Plenner’s instrument is considerably less expensive and more robust. He estimates his two-laser system would cost around $20,000, compared to the least expensive commercial alternative, which costs five times more. Recognizing the cost value of Plenner’s instrument as well as how easily a researcher can set it up, scan a target subject, and process the incoming data, engineers at other institutions have inquired whether it is available for purchase.
Plenner, however, is more interested in continuing his research at Iowa as he begins graduate work toward a Master’s degree in the fall. In addition to the academic life, he also is very interested in partnering with communities around the world to help improve water quality and enhance environmental sustainability. He has participated in a three-week winter term course that visited an area in India where overexploitation of aquifers has resulted in salinization of the soil. During a recent “alternative Spring Break” trip to Costa Rica, he and other UI students built a bus stop and worked to mitigate flooding that frequently washes out a local road.
The range of Plenner’s undergraduate liberal arts courses helped situate his engineering life in a cultural and historical context. He is living proof of the value of an education for “engineering…and something more.”