Robotics is one example of next-generation metal casting; Douglas Kelley, assistant professor of mechanical engineering, will explore whether ultrasound can be another way to improve the process. (Photo from KUKA Roboter GmbH, Wikemedia Commons)
Researcher seeks to apply ultrasound
to improve metal casting process
If
ultrasound could take images of molten metal inside a mold — as effectively as it does with a human embryo —
the efficiency of metal casting could be greatly improved, benefiting an industry dominated by small companies and narrow profit margins, says University researcher
Douglas Kelley.
But there is a daunting challenge that he and his collaborator at MIT must first overcome: finding a way for ultrasound signals to
penetrate churning flows of metal, heated to 2,000-3,000 degrees Fahrenheit, and return useful images of what happens as the metal solidifies inside the mold.
This has been "notoriously tricky" to do, Kelley says, often resulting in unexplained echoes and unreliable signals.
Kelley, an assistant professor of mechanical engineering, has
received a $273,000 grant from the National Science Foundation to collaborate on possible solutions with Antoine Allanore, assistant professor of metallurgy at MIT.
There are good reasons to look for next-generation metal casting techniques, Kelley notes. More than 90 percent of U.S. manufactured goods contain cast metal components. Use of ultrasound to monitor conditions inside those molds — as the casting occurs — could provide richly detailed images of the flow patterns of the liquid metal and its solidification patterns.
That, in turn, could help engineers
design more uniform cooling processes, and detect cracks, voids, and impurities before final ingots are produced. Casting companies could achieve "reliability, reproducibility, and productivity never before possible, all at lower cost," Kelley and Allanore noted in their proposal.
Kelley says that the biggest obstacles to obtaining ultrasound images from inside a mold occur at the interfaces between:
1. Different layers of solid and liquid that form as the metal begins to solidify;
2. The metal and the inner surface of the mold;
3. The ultrasound probe and whatever is touching it.
"
Liquid metals have high surface tension, so they often pull away from whatever is next to them," Kelley says. That can cause thin gas layers to form, for example, between the metal and the mold that encloses it. Those gas layers can
distort or completely block ultrasound signals.
The researchers will
explore several approaches that might enable the liquid metal to uniformly adhere to a mold's surface, such as chemical treatments that clean and polish the surface or remove oxidants, or small scale patterning of the surface.
Kelley, whose expertise is in fluid mixing, has worked with flowing metals and ultrasound. Allanore is an expert in electrochemistry and materials science, "so he really knows interfaces and surface chemistry, and how to control and measure what goes on at the small scales with chemistry," Kelley says. "It's a good collaboration."
The NSF funding (Allanore's companion grant is for $170,000) will allow each researcher to hire a PhD student to work on the project.
Kelley recently received an
NSF CAREER award to study how the flow of fluids in liquid metal batteries affects their performance.
"
If we can crack this problem with the ultrasound, it will have immediate synergy for the liquid metals battery project, which also uses ultrasound," Kelley says. "The two projects really complement each other."
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Polar seas store marine carbon more
efficiently that other parts of the ocean
A new study in the
Proceedings of the National Academy of Sciences provides a global picture of the fate of marine carbon, helping confirm the role that polar oceans play in regulating atmospheric carbon. The study found that the
polar seas send organic carbon to the deep sea, where it can no longer trap heat from the sun, about five times as efficiently as compared to other parts of the ocean.
"The high latitudes are much more efficient at transferring carbon into the deep ocean," said first author
Thomas Weber, who did the work as a postdoctoral researcher at the University of Washington and is now an assistant professor of earth and environmental sciences at the University of Rochester. "Understanding how this happens will certainly
allow a more complete prediction of ocean responses to climate change."
Carbon-rich material made of dead plankton clumps together to form marine snow that drifts down through the water and provides food for deeper-dwelling organisms. The continual supply of organic carbon in particles from the surface to the deep sea is known as the "biological pump."
The pump had been thought to operate at similar strength throughout the oceans, but the new study found a strong regional pattern. The authors find that about 25 percent of organic particles sinking from the surface in the polar oceans reach at least 1 kilometer (0.6 miles) — the depth required for long-term storage in deep waters. Just 5 percent of sinking carbon in the subtropics makes it that far, while the rest is released into shallower water where it can soon rejoin the atmosphere. For the tropics, the figure is about 15 percent.
Researchers looked at phosphate, a nutrient taken in by plankton in the surface and released with carbon when particles decompose. They then used a computer model of ocean currents to determine the depth at which the nutrient is released.
Why the regional pattern, which came as a surprise? The authors ruled out temperature differences, and instead found that
the size of the organisms that form marine snow seemed to be the key factor. Warm, nutrient-poor subtropical seas act as "marine deserts" where the life that survives is made up of microscopic plankton called picoplankton.
Nutrient-rich polar oceans, and to a lesser degree the equator, can support larger lifeforms — such as self-feeding phytoplankton — that sink more like a proverbial stone.
"Simply because they sink faster, these phytoplankton are more likely to reach the deep ocean before being consumed," Weber said. Read more
here.
NIH supports effort to improve ultrasound's ability
to predict if breast lesions are benign or malignant
Stephen McAleavey, associate professor of biomedical engineering, has
received a $408,368 R21 grant from the National Institutes of Health for his project, "Quantification of Shear Wave Strain Dependence in Breast Tissues."
Many women undergo breast biopsy due to lesions detected with x-ray and ultrasound imaging. The great majority of the biopsies are negative, resulting in needless expense and worry. The goal of McAleavey's project is
to improve the power of ultrasound imaging to predict if a breast lesion is benign or malignant, by using a novel, high-resolution technique to non-invasively map the non-linear mechanical properties of breast tissue.
McAleavey's coinvestigators are
Marvin Doyley, associate professor of electrical and computer engineering;
Linda M. Schiffhauer, associate professor of pathology and laboratory medicine, and
Avice O'Connell, professor of imaging sciences. Read more
here.
Researcher targets arthritis in children
About 300,000 children in the United States live with some form of rheumatic disease. The research of
Homaira Rahimi, assistant professor of pediatrics, is
aimed at helping 70,000 to 100,000 children in the U.S. with juvenile idiopathic arthritis (JIA) — a form of chronic arthritis involving combinations of swelling and pain in one or more joints, rash, fevers, inflammation of other organs (especially the eyes), and periods of remission and flareup, writes Susanne Pritchard Pallo at the
Research@URMC blog.
JIA is an autoimmune disease in which the body's immune system attacks its own tissues, causing inflammation. Anti-tumor necrosis factor (anti-TNF) drugs are commonly used to halt inflammation associated with arthritis in adults and children,
but nearly 40 percent of those populations do not respond to the drugs.
While other kinds of drugs exist for adult arthritis patients, many are not approved for use in children. Because of important ethical regulations and practical barriers to performing research studies on children,
much of what is known about JIA comes from research in adults, which significantly limits the number of medications that are available to children.
That has led researchers to investigate
alternate disease mechanisms and treatment approaches for the many different types of arthritis. For example, drainage of joint fluid via lymphatic vessels is impaired in arthritis. Rahimi is exploring
whether improving drainage of arthritic joints can help patients who are resistant to anti-TNF medications.
She is also investigating
possible links to diet. She has just begun studying the gut microbiome to understand whether certain bacteria in the intestines predispose patients to inflammation in their joints and other parts of their bodies. She suggests
there are "good" and "bad" bacteria that must be kept in balance to combat arthritic inflammation. She is just beginning to test this theory using probiotics, like those touted on yogurt labels.
Rahimi hopes that controlling arthritis with diet may provide parents of arthritic children with natural alternatives in addition to traditional medicines that may carry side effects. However, she warns that
diet may minimize the amount of drugs needed, but is not likely to cure the disease on its own.
Congratulations to . . .
Feng (Vankee) Lin, assistant professor of nursing, who will be
presented with the Brilliant New Investigator Award from the Council for the Advancement of Nursing Science. The award recognizes the contributions of scientists early in their research careers who show extraordinary potential to develop sustained programs of research certain to have significant impact on the science and practice of nursing and health care. Lin's
research focuses on
cognitive decline in older populations and those at risk for developing Alzheimer's disease and other forms of dementia. She is the principal investigator on a $2 million National Institute of Nursing grant examining how computer-based brain fitness activities may help slow cognitive and functional decline in older adults with mild cognitive impairment, and last week was awarded a $421,000 grant from the National Institute on Aging to study fatigability among aging populations. Read more
here.
Conference showcases next-generation sports technology
Technology and data analytics are revolutionizing sports — yielding
breakthroughs in training, performance improvement, and injury prevention. To share its advances in sports medicine, technology innovation and research — and to showcase next-generation sports technology from around the nation — the University is hosting the inaugural
dSports Summit on Aug. 16 at Oak Hill Country Club. Athletes and their family members, coaches, trainers, sports medicine physicians, physical therapists, and sports professionals are invited.
"The 'd' in 'dSports' refers to 'digital.' Thanks to wearable devices and sensors, the amount of data on athletic performance and injury has skyrocketed in the last couple of years," says
Michael D. Maloney, professor of orthopaedics and chief of the Division of Sports Medicine.
The summit will show how data can be a useful tool for athletes, their coaches, and their sports physicians, Maloney says.
In addition to technology demonstrations, the day includes
panel discussions and audience Q&A on predicting and preventing ACL injury; diagnosing and treating concussion; tips for athletes who want to achieve peak performance; and elite local athletes discussing their injury and recovery, as well as tips for training and game-day performance.
The event runs from 8 a.m. to 4 p.m. and includes breakfast, lunch, and snacks. Registrants are entered in a drawing to win one of five Fitbits. To learn more, go to
dSportsSummit.org.
PhD dissertation defenses
Esteban Buz , Brain and Cognitive Sciences, "Speaking with a (Slightly) New Voice: Investigating Speech Changes, Communicative Goals, and Learning from Past Communicative Success." 11 a.m., Aug. 8, 2016. 269 Meliora Hall. Advisor: Florian Jaeger.
David Kleinschmidt, Brain and Cognitive Sciences, "Perception in a Variable but Structured World: The Case of Speech Perception." 10 a.m., Aug. 9, 2016. 269 Meliora Hall. Advisor: Florian Jaeger.
Patrick Murphy, Microbiology and Immunology, "Effects of Inflammation on Tissue-resident Macrophage Efferocytosis Responses and Population Dynamics." 1:30 p.m., Aug. 10, 2016. K207 (2-6408). Advisor: Michael R. Elliott.
Xiaojuan Xia, Electrical Engineering, "Quantitative Analysis of the QRS Complex from the Digital Surface Electrocardiogram and its Interest for Predicting the Benefit of Cardiac Resynchronization Therapy." 2 p.m., Aug. 11, 2016. Computer Studies Building 426. Advisor: Jean-Phillippe Couderc.
Mark your calendar
Aug. 16: dSports Summit showcasing next-generation sports technology. 8 a.m. to 4 p.m., Oak Hill Country Club. Read more
here.
Sept. 1: Deadline to apply for pilot funding in support of a major initiative by the Del Monte Institute for Neuroscience to launch an Intellectual and Developmental Disabilities Research Center. Read more
here.
Sept. 22-24: Department of Neurology 50th anniversary celebration, including gala banquet, department updates, and poster and platform presentations showcasing research by current faculty, alumni, fellows and residents. Read more
here.
Please send suggestions and comments to Bob Marcotte. You can see back issues of Research Connections, an index of people and departments linked to those issues, and a chronological listing of PhD dissertation defenses since April 2014, by discipline.
