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Several Hundred Earthquakes Later: Dean Pennington Retires

Published June 29, 2018

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Dr. Wayne Pennington, Research Professor of Geophysical Engineering — Wayne Pennington, Research Professor of Geophysical Engineering & Professor Emeritus, Michigan Tech

As a young boy fascinated by geology, Dr. Wayne Pennington probably never imagined he would personally experience several hundred earthquakes during his lifetime. (Yes, several hundred.) He will retire tomorrow as the dean of engineering and professor of geophysics at Michigan Technological University.

He hasn’t retired from the geosciences, though—at least not yet. Dr. Pennington is a world-recognized expert in earthquakes, oil and gas exploration and development, and the intersection of those fields. He has worked in academia and industry, and conducted field work at sites around the world. In the 1970s he studied tectonic earthquakes in Latin America and Pakistan. In the early 1980s he was on the faculty at The University of Texas at Austin and studied the relationship of earthquakes to oil and gas production. In the early 1990s he worked at the research laboratory for Marathon Oil Company.

Pennington joined Michigan Tech in 1994 as a professor of geophysics. In a 1997 article in The Leading Edge, a journal of the Society of Exploration Geophyscists, he coined a new term, “seismic petrophysics”. It described the first purposeful application of rock physics theory—calibrated by laboratory and well measurements—to the interpretation of seismic data. It was also a turning point among professionals in petroleum exploration. Pennington asserted that a more comprehensive understanding of the geological and fluid factors affecting seismic energy propagation would yield results greater than the sum of the parts.

“Professionals in petroleum resource development know of the exploration expertise here at Michigan Tech in large part because of the research and educational activities of Wayne and his students and collaborators,” says Dr. John Gierke, current chair of the university’s GMES department. “Their efforts are aimed at integrating geological and geophysical understanding, a coupling encompassed in ‘seismic petrophysics’ that bolsters both disciplinary aspects of exploration. The result has been more insightful interpretations and more promising discoveries.”

“The data-driven emphasis of ‘seismic petrophysics’ requires a thorough understanding of the complex interactions of rock and fluid mechanics on the seismic response when exploring for and developing petroleum resources,” says Michigan Tech alumnus Dr. Joshua Richardson, a geophysicist at Chevron Corporation. “This integrated approach allows petroleum to be produced as efficiently and safely as possible.”

As a professor, Pennington taught his students at Michigan Tech how to interpret integrated (geophysical, geological, and engineering) data sets for reservoir characterization. He also used earthquake seismology to teach geology and physics to local middle and high school students. His lab, SPOT, encompassed “the people, the laboratory, the computers, the publications, and the projects associated with seismology, petrophysics, and their union: seismic petrophysics.”

Pennington became chair of Michigan Tech’s Department of Geological and Mining Engineering Sciences in 2004, and then Dean of the College of Engineering in 2013. He continued his research activities as Dean, advising graduate students and publishing research results. He oversaw increases in undergraduate and graduate enrollment, degrees granted, and research expenditures. He hired four outstanding department chairs and promoted interdisciplinary cooperation and research within the college and across campus.

He has held other important positions during his career, including president of the American Geosciences Institute, Jefferson Science Fellow at the US Department of State and USAID, as well as outstanding mentor, advisor, colleague, supervisor, and friend.

During his last few days as Dean, Dr. Pennington generously answered our questions about himself and his plans for retirement.

Hometown:
I was born as the middle child of three to a dairy-farming family outside of Rochester, Minnesota. By the time I was 8 years old, we moved east, settling in Weehawken, New Jersey (above the Lincoln Tunnel into Manhattan). I earned a scholarship to The Peddie School, a private boarding school, for my last three years of high school. So I don’t really have a hometown other than the Copper Country, where I have lived longer than anywhere else.

Family:
My wife, Laura is a retired schoolteacher, most recently having taught at Hancock’s Barkell Elementary School. Our older son, Matthew, is an MD/PhD anesthesiologist with the University of Washington in Seattle where his wife is a gynecological oncologist; their son has just completed kindergarten. Our younger son, Keith, has degrees in biomedical engineering and business and is currently a PhD candidate in business at the University of Minnesota; his wife is a biomedical quality engineer for a large consulting firm. Both of our sons are Eagle Scouts and graduates of Houghton High School.

Number of times you have visited the site of an earthquake:
I have been in two large damaging earthquakes: in Pakistan in 1974 (the “Pattan” earthquake”) while living there and maintaining a seismic array for Columbia University; and in southern Mexico in 1979 (the “Petatlan” earthquake, magnitude 7.7) while setting up a local seismic array to monitor what turned out to be foreshocks. Including the aftershock series from those events, and many other smaller events, such as rock bursts inside coal mines and volcanic earthquakes on the Aleutian Islands, I have experienced at least several hundred earthquakes. I visited Haiti twice after the 2010 earthquake there; once as a member of a team from the US State Department, and once on a team from the United Nations.

How/Why did you choose geophysics?
I always loved geology, even as a small child. But once I got to college and realized I could do geoscience using math, there was no question of the subdiscipline that beckoned. Field work in exotic locations was also a major draw.

How/Why did you choose Michigan Tech?
When I decided to leave a comfortable job at an oil company research center, having determined that the job I enjoyed there would not exist much longer, I looked for a return to academics at an institution that was the “right” size, where I could merge science and engineering, and where applied research was valued. Michigan Tech was one of the rare institutions that ticked all boxes. Returning to the northern Midwest was attractive, particularly because the earthquake hazard is low here.

Part of the job you enjoyed most as professor, chair and then dean?
All those positions had their positive aspects, but I must say that I missed teaching and working with graduate students once I got a couple years into my position as dean.

Most rewarding aspect of your job?
Retirement. You know the joke about the two happiest days in a boat-owner’s life (the day he buys his first boat, and the day he sells his last boat)? It’s like that: there were many exciting and rewarding aspects in each of my career stages, both in academia and in industry. Starting each new position was exciting, yet so is leaving the last one.

Number of graduate students advised?
I’m not sure, but it numbers in the dozens.

Your biggest goal now?
I have a few short-term goals: attending a bar-tending class to improve my skills at making craft cocktails; continuing to offer training to industry; better understanding induced seismicity from wastewater injection; and evaluating the possibility of writing a book on “seismic petrophysics”. All while maintaining my kayaking and trail-developing skills. I will spend February through May of 2019 on a Fulbright at Curtin University in Perth, Australia, researching ways to better monitor oil and gas production and carbon sequestration.

What advice do you give to new students? New faculty? New chairs? New deans?
Don’t let anything or anyone discourage you. Listen to opinions but make up your own mind. Maintain your integrity above all else.

Best advice you’ve gotten so far about retiring?
I haven’t listened to any of it.

Thank you, Dr. Pennington—we wish you the absolute best in your new endeavors as a professor emeritus and research professor of geophysical engineering!

Words of wisdom written by Dr. Pennington over the years, just a sampling:

Students
“Students these days are a bit different from when I was (or many of you were) sweating over finals and cheering for our teams. They understand the need for natural resources, but are equally concerned about people and the environment, and their own lifestyle choices. They want to know how to make use of natural resources sustainably (leaving no legacy for others to deal with), and how to allow indigenous peoples to benefit from the development. They are concerned with how Earth works, but they want to use that knowledge to directly aid those who live the path of volcanic flows, or in earthquake hazard areas—while learning details about the internal operations and mutual interactions of features from the core to the atmosphere, and beyond. They want to combine engineering applications with natural science observations. In short, they want to ‘do’ and not just ‘learn.’”

Valued colleagues and their retirement
“As many of our long-time faculty retire, they are, in some sense, replaced by new faculty. In another sense, of course, these retiring faculty can never be replaced. Who can claim the legacy of Lloyal Bacon, perhaps the most-loved professor I have ever met? Nobody.”

Teaching
“In most classrooms, the students work on a problem, they get the right answer, and they’re done. But we all know that, in the real world, you work on a project—something unexpected happens—and you have to figure out the problem, explain it to your colleagues, and collectively plan your response to the situation.”

Research
“The research we do is conducted through computer modeling, in the laboratory, or in the field—from inside the Earth to outer space and everywhere in between—but it has common goals.”

—Wayne Pennington

Invent It Build It: Six Questions with Hannah Cunningham

Published March 7, 2018

By Kim Geiger

Hannah Cunningham '18 BME, pictured here in the colored-glass walkway at the Aros Art Museum in Denmark. Credit: Taran Schatz — Hannah Cunningham ’18 BME, pictured here in the colored-glass walkway at the Aros Art Museum in Denmark. Credit: Taran Schatz

Hannah Cunningham, a senior majoring in biomedical engineering at Michigan Tech, has been working with kids since she was in high school. Volunteering several times at the Society of Women Engineers’ annual Invent it Build It event for middle school girls was a natural thing for her to do. She took part while attending SWE conferences in Nashville, Philadelphia, and most recently at the National SWE WE17 Conference in Austin, Texas.

Q: What’s it like to volunteer for Invent It Build It?
A: I’ve had a few different roles. I’ve worked directly with the girls as a table leader, I’ve staged materials during the event, and been a “floater” who simply fills in where help is needed with things like registration, grabbing forgotten supplies from the hotel, or pouring oil into cups.

I had the greatest interaction with the girls as a table leader. My primary job was to direct my table of four or five girls through the two activities during the day, while making sure they were thinking critically about the engineering challenge and developing their engineering skills. Luckily, they were middle schoolers, so it was easy to talk with them and learn more about them.

Q: Do you see yourself in any of the participants?
A: The girls who attend are local to the city where the conference is being held. For the most part they’re very similar. They don’t really have any idea what they want to do, but engineering could be their future. At the event they work together on engineering challenges with varying levels of teamwork, but all are capable of providing something to the challenge.

At that age it can be difficult to see your own contribution. It’s even more difficult to respect your own work without comparing it to everyone else’s. This event gives them a chance to build one thing as a team, with each participating in some way.

I try not to remember myself as a middle schooler, but some of the girls definitely remind me of myself. When faced with the project/challenge, they work at it, and work hard, until they’ve come to final product.

Q: Are you involved in any other engineering outreach?
A: While at Michigan Tech I have taught various courses for first and second graders through the Center for Science and Environmental Outreach led by Joan Chadde-Schumaker. When I teach these classes, even if the topic is not related to engineering, such as wildlife exploration, I always make sure to develop a project to include engineering. I believe engineering projects challenge kids’ creativity, teamwork skills and technical skills. Engineering projects are fantastic for any classroom setting and the supplies can be simple, recyclable materials.

Q: What would you like to do when you graduate?
A: I am due to graduate with a BS in biomedical engineering this Spring (!). I plan to pursue an accelerated master’s degree in Kinesiology next year. I wan to finish my research and learn more about biomechanics. I’d like to become involved in a company or university that will allow me to develop and/or research products that can be beneficial for human health. I’m interested in biomechanics, so anything dealing with treating, modifying, or enhancing human movement is fair game.

Q: How has being involved with SWE impacted your life so far?
A: I’ve learned about the many different roles women can have in engineering. SWE has helped me develop my skills as a professional, by offering networking events with professionals and businesses. My own educational path has slowly directed me away from engineering, but I still feel strongly that I can still be involved even if my job title isn’t “engineer”.

Inspired by nature—Getting underwater robots to work together, continuously

Published December 4, 2017

By Kim Geiger

Nina Mahmoudian, Mechanical Engineering-Engineering Mechanics

Imagine deploying multiple undersea robots, all in touch and working together for months, even years, no matter how rigorous the mission, brutal the environment, or extreme the conditions.

It is possible, though not quite yet. “Limited energy resources and underwater communication are the biggest issues,” says Michigan Tech Researcher Nina Mahmoudian. Grants from a National Science Foundation CAREER Award and the Young Investigator Program from the Office of Naval Research are helping Mahmoudian solve those issues and pursue her ultimate goal: the persistent operation of undersea robots.

“Autonomous underwater vehicles (AUVs) are becoming more affordable and accessible to the research community,” she says. “But we still need multipurpose long-lasting AUVs that can adapt to new missions quickly and easily.”

Mahmoudian has already developed a fleet of low-cost, underwater gliders, ROUGHIEs, to do just that. Powered by batteries, they move together through the water simply by adjusting their buoyancy and weight. Each one weighs about 25 pounds. “ROUGHIE, by the way, stands for Research-Oriented Underwater Glider for Hands-on Investigative Engineering,” adds Mahmoudian.

“My most exciting observation was a Beluga mother and calf swimming together. It’s very similar to our recharge on-the-fly concept.”

—Nina Mahmoudian

“The ROUGHIE’s open control architecture can be rapidly modified to incorporate new control algorithms and integrate novel sensors,” she explains. “Components can be serviced, replaced, or rearranged in the field, so scientists can validate their research in situ.” Research in underwater control systems, communication and networking, and cooperative planning and navigation all stand to gain.

Mahmoudian observes Mother Nature to design robotic systems. “There is so much to learn,” she says. “My most exciting observation was a Beluga mother and calf swimming together. It’s very similar to our recharge on-the-fly concept. The technology is an early stage of development.”

Mahmoudian’s students apply and implement their algorithms on real robots and test them in real environments. They also give back to the community, by teaching middle school students how to design, build, and program their own low-cost underwater robots using a simple water bottle, called a GUPPIE.

“As a girl growing up, I first thought of becoming an architect,” says Mahmoudian. “Then, one day I visited an exhibition celebrating the 30th anniversary of space flight. That’s when I found my passion.” Mahmoudian went on to pursue aerospace engineering in Iran, and then graduate studies at Virginia Tech in the Department of Aerospace and Ocean Engineering. “Underwater gliders share the same physical concepts as airplanes and gliders, but deal with different fluid density and interactions,” she says.

Now at Michigan Tech, Mahmoudian’s work advances the abilities of unmanned robotic systems in the air, on land, and under sea. “Michigan Tech has easy access to the North Woods and Lake Superior—an ideal surrogate environment for testing the kind of autonomous systems needed for long term, challenging expeditions, like Arctic system exploration, or searching for signs of life on Europa, Jupiter’s moon.” She developed the Nonlinear and Autonomous Systems Laboratory (NAS Lab) in 2011 to address challenges that currently limit the use of autonomous vehicles in unknown, complex situations.

More than scientists and engineers, Mahmoudian wants simple, low-cost AUV’s to be available to anyone who may need one. “I envision communities in the Third World deploying low-cost AUVs to test and monitor the safety and quality of the water they use.”

Demand dispatch—Balancing power in the grid in a nontraditional way

Published December 1, 2017

By Kim Geiger

According to the National Renewable Energy Lab (NREL), distributed energy resources like these photovoltaic (PV) systems in a Boulder neighborhood—especially when they are paired with on-site storage—may eventually make large centralized power plants obsolete. Photo Credit: Topher Donahue

Traditionally, in the electric power grid, generation follows electric power consumption, or demand. Instantaneous fluctuation in demand is primarily matched by controlling the power output of large generators.

Sumit Paudyal, Electrical & Computer Engineering

As renewable energy sources including solar and wind power become more predominant, generation patterns have become more random. Finding the instantaneous power balance in the grid is imperative. Demand dispatch—the precise, direct control of customer loads—makes it possible.

Michigan Tech researcher Sumit Paudyal and his team are developing efficient real-time control algorithms to aggregate distributed energy resources, and coordinate them with the control of the underlying power grid infrastructure.

“Sensors, smart meters, smart appliances, home energy management systems, and other smart grid technologies facilitate the realization of the demand dispatch concept,” Paudyal explains.

“The use of demand dispatch has promising potential in the US, where it is estimated that one-fourth of the total demand for electricity could be dispatchable using smart grid technologies.”

—Sumit Paudyal

Coordination and control in real time is crucial for the successful implementation of demand dispatch on a large scale. “Our goal is to enable control dispatch distributed resources for the very same grid-level applications—frequency control, regulation, and load following—traditionally provided by expensive generators,” adds Paudyal.

“We have solved the demand dispatch problem of thermostatically-controlled loads in buildings and electric vehicle loads connected to moderate-size power distribution grids. The inherent challenge of the demand dispatch process is the computational complexity arising from the real-time control and coordination of hundreds to millions of customer loads in the system,” he adds. “We are now taking a distributed control approach to achieve computational efficiency in practical-sized, large-scale power grids.”

Vital signs—Powering heart monitors with motion artifacts

Published November 14, 2017

By Kim Geiger

More than 90 percent of US medical expenditures are spent on caring for patients who cope with chronic diseases. Some patients with congestive heart failure, for example, wear heart monitors 24/7 amid their daily activities.

Michigan Tech researcher Ye Sarah Sun develops new human interfaces for heart monitoring. “There’s been a real trade-off between comfort and signal accuracy, which can interfere with patient care and outcomes,” she says. Sun’s goal is to provide a reliable, personalized heart monitoring system that won’t disturb a patient’s life. “Patients need seamless monitoring while at home, and also while driving or at work,” she says.

Sun has designed a wearable, self-powered electrocardiogram (ECG) heart monitor. “ECG, a physiological signal, is the gold standard for diagnosis and treatment of heart disease, but it is a weak signal,” Sun explains. “When monitoring a weak signal, motion artifacts arise. Mitigating those artifacts is the greatest challenge.”

Sun and her research team have discovered and tapped into the mechanism underlying the phenomenon of motion artifacts. “We not only reduce the in uence of motion artifacts but also use it as a power resource,” she says.

Their new energy harvesting mechanism provides relatively high power density compared with traditional thermal and piezoelectric mechanisms. Sun and her team have greatly reduced the size and weight of an ECG monitoring device compared to a traditional battery-based solution. “The entire system is very small,” she says, about the size of a pack of gum.

“We not only reduce the influence of motion artifacts but also use it as a power resource.”

—Ye Sarah Sun

Unlike conventional clinical heart monitoring systems, Sun’s monitoring platform is able to acquire electrophysiological signals despite a gap of hair, cloth, or air between the skin and the electrodes. With no direct contact to the skin, users can avoid potential skin irritation and allergic contact dermatitis, too—something that could make long-term monitoring a lot more comfortable.

Where rubber becomes the road—Testing sustainable asphalt technologies

Published November 14, 2017

By Kim Geiger

Zhanping You research team — A Michigan Tech research team led by Zhanping You tests a new, cooler way to make rubberized asphalt.

Over 94% of the roads in the United States are paved with asphalt mix. Each year, renovating old highways with new pavement consumes about 360 million tons of raw materials. It also generates about 60 million tons of old pavement waste and rubble.

Zhanping You, Civil & Environmental Engineering

Recycling these waste materials greatly reduces the consumption of neat, unmodified asphalt mix and lowers related environmental pollution. But blending recycled asphalt pavement (RAP) with fresh asphalt mix presents several challenges, potentially limiting its usefulness.

Not to Michigan Tech researcher Zhanping You. “One noticeable issue of using RAP in asphalt pavement is the relatively weaker bond between the RAP and neat asphalt, which may cause moisture susceptibility,” he explains. “Modifying the asphalt mix procedure and selecting the proper neat asphalt can effectively address this concern.”

You tests a variety of recycled materials to improve asphalt pavement performance. Crumb rubber, made from scrap tires, is one such material. “Crumb rubber used in asphalt reduces rutting and cracks, extends life, and lowers noise levels. Another plus—building one mile of road with crumb rubber uses up to 2,000 scrap tires. Hundreds of millions of waste tires are generated in the US every year,” he adds.

Adding crumb rubber to asphalt mix has its own share of problems. “When crumb rubber is blended into asphalt binder, the stiffness of the asphalt binder is increased. A higher mixing temperature is needed to preserve the flowability. Conventional hot-mix asphalt uses a lot of energy and releases a lot of fumes. We use a foaming process at lower temperatures that requires less energy and reduces greenhouse gas emissions.”

“Building one mile of road with crumb rubber uses up to 2,000 scrap tires. Hundreds of millions of waste tires are generated in the US every year.”

—Zhanping You

You and his team integrate state-of-the-art rheological and accelerated-aging tests, thermodynamics, poromechanics, chemical changes, and multiscale modeling to identify the physical and mechanical properties of foamed asphalt materials. With funding from the Michigan Department of Environmental Quality, they have constructed test sections of road in two Michigan counties to monitor field performance.

Another possible solution is asphalt derived from biomass. You’s team used bio oil in asphalt and found it improved pavement performance. They’re also investigating nanomaterial-modified asphalt. “Soon we’ll have mix recipes to adapt to all environmental and waste supply streams,” he says.

The holy grail of energy storage—Solving the problems of lithium anodes

Published November 14, 2017

By Kim Geiger

Samsung exploded phone — A damaged Samsung Galaxy Note 7 after its lithium battery caught fire. Photo Credit: Shawn L. Minter, Associated Press

State-of-the-art mechanical characterization of pure lithium metal, performed at submicron-length scales, provides signifcant physical insight into critical factors that limit the performance of next generation energy storage devices.

Erik Herbert, Michigan Tech — Erik Herbert, Materials Science & Engineering

Compared to competing technology platforms, a pure lithium anode potentially offers the highest possible level of volumetric and gravimetric energy density. Gradual loss of lithium over the cycle life of a battery prevents the full fruition of this energy technology.

Michigan Tech researchers Erik Herbert, Stephen Hackney, and their collaborators at Oak Ridge National Laboratory and the University of Michigan are investigating the behavior of a lithium anode accessed through, and protected by, polycrystalline superionic solid electrolytes. Their goals: Mitigate the loss of lithium; prevent dangerous side reactions; and enable safe, long-term, and high-rate cycling performance.

“We want to maintain efficient cycling of lithium in a battery over many cycles, something that’s never been done before,” says Herbert. “The fundamental challenge is figuring out how to maintain a coherent interface between the lithium anode and the solid electrolyte. Defects formed in the lithium during cycling determine the stability and resistivity of the interface. Once we see how that happens, it will reveal design rules necessary to successfully fabricate the solid electrolyte, and the battery packaging.”

The team is launching parallel efforts to address these issues. Herbert, for his part, wants to learn exactly how lithium is consumed on a nanoscale level, in real time. “We want to know why the interface becomes increasingly resistive with cycling, how the electrolyte eventually fails, how defects in the lithium migrate, agglomerate, or anneal with further cycling or time, and whether softer electrolytes can be used without incursion of metallic lithium into the electrolyte,” he says. “We also want to learn how processing and fabrication affect interface performance.”

“We want to maintain efficient cycling of lithium in a battery over many cycles, something that’s never been done before.”

– Erik Herbert

Surface of the polycrystalline lithium film, with over 100 residual impressions from targeted test sites

To answer these questions, Herbert conducts nano-indentation studies on vapor-deposited lithium films, various sintered solid electrolytes, and lithium films in fully functional solid-state batteries.

“The data from these experiments directly enable exam-ination of the complex coupling between lithium’s micro-structure, its defects, and its mechanical behavior,” says Herbert. “So far we’ve gained a better understanding of the mechanisms lithium utilizes to manage pressure (stress) as a function of strain, strain rate, temperature, defect structure, microstructural length scale, and in-operando cycling of the battery.”

Atomic resolution image of a spinel intergrowth lithium ion battery electrode particle and associated convergent beam electron diffraction pattern. The ordered dots all over the black triangle (the particle) are atomic columns, with a convergent beam electron diffraction pattern in white at the top.

Michigan Tech’s FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM) positions Michigan Tech faculty on the leading edge of new imaging capability for structural and chemical analysis at the nano-scale.

Phosphorus eaters—Using bacteria to purify iron ore

Published September 13, 2017

By Kim Geiger

Many iron ore deposits around the world are extensive and easy to mine, but can’t be used because of their high phosphorus content. Phosphorus content in steel should generally be less than 0.02 percent. Any more and steel becomes brittle and difficult to work.

Beneficiation plant processing, which treats ore to make it more suitable for smelting, only works if the phosphorus mineral grains are bigger than a few micrometers in size. Often, phosphorus is so finely disseminated through iron ore that grinding and physically separating out the phosphorus minerals is impractical.

Michigan Tech researcher Tim Eisele is developing communities of live bacteria to inexpensively dissolve phosphorus from iron ore, allowing a low-phosphorus iron concentrate to be produced. “For finely dispersed phosphorus, until now, there really hasn’t been a technology for removing it,” he says.

Phosphorus is critical to all living organisms. Eisele’s experiments are designed so that organisms can survive only if they are carrying out phosphorus extraction. He uses phosphorus-free growth media.

“We’ve confirmed that when there is no iron ore added to the media, there is no available phosphorus and no bacterial growth.”

– Tim Eisele

Eisele is investigating two approaches, one using communities of aerobic organisms to specifically attack the phosphorus, and another using anaerobic organisms to chemically reduce and dissolve the iron while leaving the phosphorus behind. He obtained organisms from local sources—his own backyard, in fact, where natural conditions select for the types of organisms desired. Eisele originally got the idea for this approach as a result of the high iron content of his home well water, caused by naturally-occuring anaerobic iron-dissolving organisms.

On the right, anaerobic bacteria dissolve iron in the ferrous state. On the left, recovered electrolytic iron. — In the beaker on the right, anaerobic bacteria dissolve iron in the ferrous state. On the left, recovered electrolytic iron.

Eisele cultivates anaerobic and aerobic organisms in the laboratory to fully adapt them to the ore. “We use mixed cultures of organisms that we have found to be more effective than pure cultures of a single species of organism. Using microorganism communities will also be more practical to implement on an industrial scale, where protecting the process from contamination by outside organisms may be impossible.”

Verification and validation—Predicting uncertainties early on

Published August 2, 2017

By Kim Geiger

Shabakhti Research

Mahdi Shabakhti — Mahdi Shahbakhti
Mechanical Engineering–Engineering Mechanics

The verification and validation (V&V) process for a typical automotive vehicle and powertrain electronic control unit takes approximately two years, and costs several million dollars. V&V are essential stages in the design cycle of an industrial controller, there to remove any gap between the designed and implemented controller. Computer modeling has brought about improvements over the years, but the gap remains.

Michigan Tech researcher Mahdi Shahbakhti has made significant progress to remove that gap, using system models to easily verify controller design. His solution features an adaptive sliding mode controller (SMC) that helps the controller deal with imprecisions in the implementation of the system.

The research is funded by the National Science Foundation GOALI program, or Grant Opportunities for Academic Liaison with Industry. Shahbakhti’s team and fellow researchers from the University of California, Berkeley, and Toyota USA in Ann Arbor, Michigan are nearing the end of their three-year collaborative GOALI project.

“Analog-to-digital conversion (ADC) is one of the main sources of controller implementation imprecisions, mostly due to sampling and quantization,” says Shahbakhti. “Our approach mitigates ADC imprecisions by first identifying them in the early stages of the controller design cycle. We first developed a mechanism for real-time prediction of uncertainties due to ADC and then determined how those uncertainties propagated through the controller. Finally we incorporated those predicted uncertainties into the discrete sliding mode controller (DSMC) design.”

“Analog-to-digital conversion (ADC) is one of the main sources of controller implementation imprecisions, mostly due to sampling and quantization.”

– Mahdi Shahbakhti

Shahbakhti and his team tested an actual electronic control unit at Michigan Tech in a real time processor-in-the-loop setup. Their approach significantly improved controller robustness to ADC imprecisions when compared to a baseline sliding controller. In a case study controlling the engine speed and air-fuel ratio of a spark ignition engine, the DSMC design with predicted uncertainty provided a 93 percent improvement compared to a baseline sliding controller.

Toyota works closely with the research team to integrate GOALI project results into the design cycle for its automotive controllers. The company provided team members with an initial week of training on its V&V method of industrial controllers, and also participates with Shabakhti’s team in online biweekly meetings. “The concept of this project is fundamental and generic—it can be applied to any control system, but complex systems, such as those in automotive applications, will benefit most,” notes Shahbakhti.

What’s in the air? Understanding long-range transport of atmospheric arsenic

Published August 2, 2017

By Kim Geiger

Coal-fired power plant on the Navajo Nation near Page, Arizona

Once emitted into the atmosphere, many air pollutants are transported long distances, going through a series of chemical reactions before falling back to the Earth’s surface. This makes air pollution not just a local problem, but a regional and a global one.

Shiliang Wu — Shilliang Wu, Geological & Mining Engineering & Sciences, Civil & Environmental Engineering

“If you’d been living in London in December 1952, you’d probably remember what air pollution can do—in just a couple of weeks, a smog event killed thousands of people,” says Michigan Tech researcher Shilliang Wu.

“Today, photos of air pollution in China and India flood the Internet,” he adds. “Air pollution remains a significant challenge for the sustainability of our society, with detrimental effects on humans, animals, crops, and the ecosystem as a whole.”

An assistant professor with a dual appointment in Geological and Mining Engineering and Sciences, and Civil and Environmental Engineering, Wu examines the impacts of human activities on air quality, along with the complicated interactions between air quality, climate, land use, and land cover. Using well-established global models, he investigates a wide variety of pollutants including ozone, nitrogen oxides, volatile organic compounds, aerosols, mercury, and arsenic.

Wu’s research team recently developed the first global model to simulate the sources, transport, and deposition of atmospheric arsenic including source-receptor relationships between various regions. They were motivated by a 2012 Consumer Reports magazine study, which tested more than 200 samples of rice products in the US and found that many of them, including some organic products and infant rice cereals, contained highly toxic arsenic at worrisome levels.

“Our results indicate that reducing anthropogenic arsenic emissions in Asia and South America can significantly reduce arsenic pollution not only locally, but globally.”

– Shilliang Wu

“Our model simulates arsenic concentrations in ambient air over many sites around the world,” says Wu. “We have shown that arsenic emissions from Asia and South America are the dominant sources of atmospheric arsenic in the Northern and Southern Hemispheres, respectively. Asian emissions are found to contribute nearly 40 percent of the total arsenic deposition over the Arctic and North America. Our results indicate that reducing anthropogenic arsenic emissions in Asia and South America can significantly reduce arsenic pollution not only locally, but globally.”

Wu’s model simulation is not confined to any region or time period. “We can go back to the past or forward to the future; we can look at any place on Earth. As a matter of fact, some of my colleagues have applied the same models to Mars,” he says, adding: “In any case, the atmosphere is our lab, and we are interested in everything in the air.”

Category: Features

“My most exciting observation was a Beluga mother and calf swimming together. It’s very similar to our recharge on-the-fly concept.”

“The use of demand dispatch has promising potential in the US, where it is estimated that one-fourth of the total demand for electricity could be dispatchable using smart grid technologies.”

“We not only reduce the influence of motion artifacts but also use it as a power resource.”

“Building one mile of road with crumb rubber uses up to 2,000 scrap tires. Hundreds of millions of waste tires are generated in the US every year.”

“We want to maintain efficient cycling of lithium in a battery over many cycles, something that’s never been done before.”

“We’ve confirmed that when there is no iron ore added to the media, there is no available phosphorus and no bacterial growth.”

“Analog-to-digital conversion (ADC) is one of the main sources of controller implementation imprecisions, mostly due to sampling and quantization.”

“Our results indicate that reducing anthropogenic arsenic emissions in Asia and South America can significantly reduce arsenic pollution not only locally, but globally.”