Mays presents to Colorado Ground Water Association

David-Mays- (10-2014)-webOn Wednesday, March 17, David Mays, associate professor of civil engineering, was the guest speaker at the at the Colorado Groundwater Association March meeting. His presentation, “Plume Spreading for Improved Groundwater Remediation,” was well-received by the group.


Groundwater, found in soils and aquifers, represents 99% of the world’s supply of liquid fresh water. It is therefore a crucial component of our water supply, especially in arid states like Colorado. Unfortunately, gravity means that pollution often finds its way into groundwater, necessitating the art, science, and multi-billion dollar business of groundwater remediation.

This talk will describe an ongoing study, using both computer simulations and laboratory experiments, designed to test the simple hypothesis that groundwater remediation can benefit from an engineered approach to promote plume stretching and folding. This work, funded by the National Science Foundation, represents a new approach to the hydraulics of groundwater remediation based on a key idea borrowed from chaos theory: That stretching and folding optimizes mixing in laminar flows.

The lack of turbulent mixing soils and aquifers makes it difficult to blend chemical additives, which is why the National Research Council has observed that groundwater remediation reactions are usually confined to a narrow interface zone between the injected additives and the contaminated groundwater. The goal if this work is to take the literature on fluid mechanics and turn it into an engineered sequence of injections and extractions at wells that, it is hoped, will provide a new paradigm for the hydraulics of groundwater remediation. Accordingly, this talk will provide a brief introduction to chaos theory, and then summarize computer simulations and laboratory experiments designed to demonstrate stretching and folding for plume spreading.


David Mays serves on the faculty of the Department of Civil Engineering at the University of Colorado Denver, located on the Auraria Campus downtown, where he teaches fluid mechanics, pipe network design, and three graduate courses on hydrology. His research program addresses fundamental challenges in groundwater remediation using tools borrowed from complex systems science, including chaos theory (i.e., stretching and folding) and colloid science (i.e., fractal dimensions of permeability-reducing deposits in aquifers). Applications of this research have included pervious concrete, aquifer storage and recovery, and hydrocarbon reservoir engineering. Since joining CU Denver in 2005, Dr. Mays has advised 17 graduate students and published 14 refereed papers and 5 book chapters. More information, including course materials, are available through his website (

Yakacki named college Outstanding Faculty in Research

Yakacki (9-12)-WEBChristopher Yakacki, assistant professor of mechanical engineering, has been selected as the 2015 recipient of the College of Engineering and Applied Science Outstanding Faculty in Research Award. The award, which includes a cash prize and a commemorative plaque, will be presented to Chris at the 2015 Year End Celebration on May 15.

He is also in the running for the campuswide Annual Award for Excellence in Research/Creative Activities.

Congratulations again, and best of luck with the campus-level award.

NSF CAREER Award supports work in smart polymers

Yakacki (9-12)-WEBAssistant Professor of Mechanical Engineering Christopher Yakacki received a 2014 National Science Foundation CAREER Award. Yakacki’s CAREER award project, “A Two-Stage Processing Approach to Shape-Switching Liquid-Crystalline Elastomers for Biomedical Applications,” is a five-year investigation into the development of a reaction mechanism to tailor and manufacture liquid-crystalline elastomers (LCEs) for biomedical applications.

LCEs are a class of smart polymers that can repeatedly change shape and optical properties in response to a stimulus, such as heat or light. Traditionally, LCEs have been difficult to synthesize and manufacture for applications such as biomedical devices. This CAREER award is to investigate a new approach and reaction mechanism to tailor and manufacture these materials for biomedical applications, specifically shape-changing biomedical devices.

Yakacki’s CAREER award will also serve to create summer workshops for local high school students, which will give them a hands-on experience in how smart polymers can be used in biomedical applications. Using this new technology, Yakacki will apply his teaching and industry experience to design and develop interference devices for anterior cruciate ligament (ACL) tears, which also illustrates how the fields of mechanical engineering, materials science, and bioengineering can combine. He hopes to show that engineering isn’t a confined area of study, and that although there are individual degree programs, engineers often solve problems using an interdisciplinary approach. Through this endeavor, Yakacki wants to give students a better look at how a college education can lead to unique, real-world opportunities and experiences.

Study by Kim, Marshall and Pal says 2013 floods could have been less destructive

The severe flooding that devastated a wide swath of Colorado last year might have been less destructive if the bridges, roads and other infrastructure had been upgraded or modernized, according to a new study from the University of Colorado Denver.

“People need to understand the importance and seriousness of infrastructure,” said Jimmy Kim, associate professor of civil engineering and lead author the study. “There is an assumption that a bridge will stand forever and that’s simply not true.”

Kim along with co-authors Wesley Marshall, and Indrani Pal, both assistant professors of civil engineering, examined the causes of the flooding and its impact on infrastructure.

The stage was set for the deluge when an unusual low pressure system generated a steady plume of monsoonal moisture flow from the Pacific Ocean toward Colorado’s Front Range communities.

The rain began on Sept. 9, 2013 and didn’t stop until the 16th. In just days, places like Boulder County received three-quarters of its yearly precipitation, the study said. Bridges collapsed, roads failed and homes were swept away.

According to the study, 120 bridges now need structural repair. Many were damaged by rushing water which washed out backfill soil and exposed bridge foundations.

Kim said new `scour control’ methods, aimed at reducing these washouts, should be developed to help bridges withstand future flooding.

“You can do that by upgrading existing piers (columns) supporting the bridge or changing current design approaches” he said. “The Colorado Department of Transportation is currently working on improving scour design for bridge structures.”

The researchers also suggested improving roads made of concrete or bituminous material like asphalt since they often disintegrate when flooded. Kim said fiber, nano-particles or polymeric admixtures could be added to these construction materials to increase tensile strength and flexibility while reducing cracking.

The study noted the successful use of geographic information systems (GIS) to help supply up-to-the-minute mapping and alerts about flood damage.

“The production of such data and maps extended well beyond the typical GIS community and included local news affiliates and even the City of Boulder itself,” said study co-author Wesley Marshall.

For example, on September 27, 2013, Boulder launched a `Community Flood Assessment’ crowd-sourced map using the Crowdmap application. The city asked users to submit flood reports via the website or smartphone apps. They were also asked how deep the flooding was and if they lost power. Video and photos could be uploaded to locate the event on an interactive map.

“Such efforts were not only useful during the recovery efforts but will continue to be used toward helping increase the resiliency of Colorado during such events,” Marshall said.

Overall, the researchers revealed a much wider problem.

From 1980 to 2007, about 90 percent of all global disasters were caused by flooding either by rain, tsunami, hurricane or some other natural event.

At the same time, the American Society of Civil Engineer’s 2013 Report Card for America’s Infrastructure gave the country a dismal D+. The group said $3.6 trillion was needed by 2020 to address the most serious problems.

In Colorado, the report card says, 70 percent of major roads are poor or mediocre and 566 bridges are structurally deficient.

“Reconstruction is very expensive and should be the last resort,” Kim said. “But we can repair or strengthen existing systems less expensively. We are looking at a growing national problem, one that will only get worse if we ignore it.”

The study was published last week in the Proceedings of the Institution of Civil Engineers.

This research was also featured on Channel 7 News and Colorado Public Radio.

Nikki Farnsworth receives F32 Postdoctoral Individual National Research Service Award

Farnsworth_pic Nikki Farnsworth, a postdoctoral fellow mentored by Richard Benninger in the Department of Bioengineering, has been awarded a 3-year F32 fellowship from the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) totaling $165,354. Nikki will study the dysregulation of pancreatic islet electrical activity during conditions associated with the progression of type1 diabetes, and ways to control this regulation to protect against beta cell decline.

Dr. Emily Gibson of Bioengineering secures $1M NSF grant to build unique microscope

Dr Emily Gibson

Bioengineering faculty member Emily Gibson is awarded a $1 million dollar NSF grant for development of a unique fluorescent microscope allowing visualization of dynamic cellular processes at resolutions approaching the size of  protein complexes (tens of nanometers).  Diego Restrepo, Professor of Cell and Developmental Biology, Director of the Center for Neuroscience, is co-PI of the grant and Dr. Stephanie Meyer, Research Associate in the Department of Bioengineering is key personnel.  The technology development grant will fund a 5 year effort to build the microscope making CU Denver the only place in the country with such capability for research.  The research projects enabled by the new instrument include studies of the dynamic organization of protein complexes in synapses upon control of neural plasticity, studies of the molecular-level mechanisms of odor transduction by direct stimulation of the transduction pathway, and methods for writing/reading bits at sub-diffraction dimensions in high density data storage materials.

More Grant News for Bioengineering’s Dr. Benninger

ImageDr. Richard Benninger and colleague Dr. Moshe Levi (Renal Medicine) were awarded a shared instrument grant from the NIH to purchase a new Zeiss LSM780 confocal two-photon microscope equipped with a fluorescence lifetime imaging detector. This microscope will allow researchers to view fluorescent proteins and biomarkers in live cells and autofluorescence-based disease signatures in intact tissue with unparalleled sensitivity.