Arts Everywhere Day
Arts Everywhere Day
A scaled up wave-pendulum machine became a collaboration between the UNC Departments of Mathematics, and Physics & Astronomy. It was unveiled on the lawn in front of Phillips Hall as part of UNCs art festival,Arts Everywhere Day, which is began April 7th.
The device was built by Phil Thompson in the machine shop, designed by UNC Math Grad student Francesca Bernardi and UNC Math Postdoc Dan Harris with funds from the Arts Everywhere program. Of course, we used Carolina Blue, WAY TO GO HEELS! Come see it in action from Noon-Five PM this Friday!, and see if we can improve its tuning by then.
Paul Cornwell Wins Prize
Paul Cornwell Wins Prize
Graduate Student Paul Cornwell was invited to give a talk at the IMACS Nonlinear Waves meeting, March 29 – April 1, 2017, in Athens, GA, and was awarded the Student Paper Prize, for his contribution. Huge Congratulations to Paul!
Metcalfe Gives AMS Lecture
Metcalfe Gives AMS Lecture
Jason Booth, left, and Professor Metcalfe at a later award ceremony.
The American Mathermatical Society held its Fall Southeastern Sectional Meeting on November 12-13, 2016, at North Carolina State University. Jason Metcalfe was one of the presenters during this meeting. Dr. Metcalfe’s talk was entitled: Local Energy Decay for the Wave Equation. His abstract fopllows below. Jason’s Ph.D. students Bob Booth and Katrina Morgan co-organized a special session.
We will discuss local energy decay estimates for the wave equation, which are measures of the extent to which energy from an initial disturbance leaves a given compact set. These have been especially important for the study of wave equations on nontrivial asymptotically flat space-times as other common measures of dispersion, such as Strichartz estimates or pointwise decay estimates, have been shown to follow once local energy decay is available. We will examine obstacles to such decay estimates, namely trapping and eigenfunctions / resonances, and some partial results that can be recovered when these obstacles are present. We will also discuss the stability of such estimates when the background geometry is time-dependent.
Math Members in Science
Math Members in Science
Solute is flowing from left to right in a square and skinny duct. The square case arrives with a gentler buildup, while the skinny case arrives with a more abrupt, sharper front.
Art was created with proportions in mind so spaces would make mathematical sense. Now two mathematicians from the University of North Carolina at Chapel Hill and their team have created art of their own: a method that precisely sculpts how fluids spread chemicals as they travel to hit their target.
The work, which appeared in the November 17, 2016, advance online issue of Science, has profound implications in fields such as medicine, chemistry and environmental management. Anywhere where having the ability to precisely control how drugs, chemicals and pollutants approach their destination is potentially critical for optimizing their effect, potency and lifespan.
“You might want a chemical, for example, to hit its target all at once or you might want it to build up gradually,” said McLaughlin, chair of UNC-Chapel Hill’s department of mathematics. “Until now, scientists had little control on the exact way for a chemical to do that. This work gives them a simple method so that they can achieve either of these goals — or anything in between.”
McLaughlin and his colleague, Roberto Camassa, Kenan Distinguished Professor of Mathematics, revealed that the secret to such control lies solely in the relative dimensions of the tube, not the properties of the fluid or the chemical dissolved within it. Specifically they showed that the relationship between a pipe’s width and height — or aspect ratio — governs the shape of the chemical spread as it flows with the fluid down the tube.
A circle and square are just as wide as they are tall, while an ellipse and rectangle are wider in one dimension than the other. By squishing the tube away from being a perfect circle, the researchers showed that they can change the way that a solute reaches its target: Solute traveling down a skinny pipe barrages its target fast, but if the same solution travels down a fat pipe, the solute crawls slowly upward to its target until the big punch hits at the end.
They found that precisely the same effect occurs in rectangular ducts, such that in skinny ones, solute arrives at the target strong, like a heavy punch; if you stretch the rectangle into a square, the solute reverses its approach, arriving in a slow and gradual upward swing.
“That was the big surprise,” said Camassa. “We stumbled upon this incredible disconnect between two different geometries. It’s one of nature’s universal principles governing the shape of solute spreading and it can be used to optimize results in many industries that deal with chemicals dissolved in fluid flows.”
The implications reach far and wide, particularly in microfluidic devices, which contain miniaturized components for routing and processing very small amounts of fluids. They are used in health care for making small, biological test kits or for precisely manufacturing drugs. This new work can be used to optimize microfluidic devices for any particular goal. For example, researchers can potentially optimize the delivery of cancer drugs or antibiotics to minimize damage to surrounding tissues and thus minimize side effects.
Economics also play a big role, explained McLaughlin and Camassa, who are both in UNC-Chapel Hill’s College of Arts and Sciences.
Precision elliptical pipes may be difficult and expensive to manufacture. But the new work shows that rectangular pipes, which are easier and cheaper to produce, can do the same job, delivering a fluid with calculated precision given the right aspect ratio. As a bonus, rectangular ducts stretch solute much less than ellipses, an effect that can be important in delivering more highly concentrated substances, another factor when considering cost and shape of a pipe.
The team, including graduate students Manuchehr Aminian and Francesca Bernardi, and postdoctoral scholar Daniel Harris, has revealed one of nature’s universal principles governing how fluids spread solute in microfluidic environments.
“It’s sort of a slam dunk, having analysis, computation and experiment, all these approaches confirming each other,” said McLaughlin. “It says that this phenomenon is really there and can be used for far-reaching applications.”
Story by Thania Benios, UNC Communications
World Maths Day
World Maths Day
Congratulations to Professor Idris Assani for being one of 54 mathematicians to be selected by the Royal Society as Inaugural Fellows of the American Mathematical Society.
Assani on Africa STEM Projects
Assani on Africa STEM Projects
UNC mathematics professor Idris Assani has been a consultant on Science, Technology, Engineering and Mathematics, STEM, projects in Africa for the World Bank since 2013. He will travel to Benin, his home country, Cameroon, and Burkina Faso in November to check on the progress of the Africa Centres of Excellence, a project led by the World Bank in partnership with the Association of African Universities.
The centers partner with existing universities to strengthen their capacity to deliver high quality training and applied research and to encourage students to pursue STEM degrees. “The World Bank provides them with financial support to help them enhance their STEM, health or agricultural research to have an impact on the development of the region,” Assani said. “In Burkina Faso, for example, one of the projects they’ve been working on involves water management and recycling, waste management, the impact on agriculture and environment. There is another center in Nigeria focused on health that has made major contributions to fight against the Ebola virus.”
There are about 40 centers throughout Africa, with World Bank funding for the project set to end in 2018. Assani said one of the reasons he was attracted to the project was its emphasis on results and sustainability. “We help them develop concrete and effective evaluation plans, then we visit to make sure the plans are happening,” he said. “The financing is based on results. … If only 10 or 15 percent manage to sustain themselves, I’ll be happy.” Assani called the centers a “landmark project for the World Bank.”
Assani came to UNC’s College of Arts and Sciences in 1988, after completing two years as a postdoctoral fellow in the department of mathematics at the University of Toronto in Canada. In 1986, he completed his “Doctorate es Sciences” at the University of Paris, France. In 2012, he became an inaugural fellow of the American Mathematical Society and also served on its selection committee that year.
“This is a great opportunity for Africa,” he said. “I came from Benin to North America to do research, and there are many people with the brain power to do that.”
Assani strongly believes that the mathematics department should be involved in global outreach. He brought two students from Ghana to UNC, both of whom graduated with master’s degrees between 2008 and 2011. He also organizes the Ergodic Theory Workshop every year since 2002 with continuous National Science Foundation support, and invites many scholars from all over the world, including Africa and Latin America. While mathematics might seem to be an abstract concept, he believes that the skills developed in training can be crucial in addressing complex problems. “The analytical mindset can help you get significant results and structure solutions, and that’s what most of these countries need,” Assani said.
Read more about the African Centers of Excellence.
Mucha Receives Award
Mucha Receives Award
The Office of Postdoctoral Affairs at the University of North Carolina at Chapel Hill, is pleased to announce that Peter Mucha, Ph.D., Bowman and Gordon Gray Professor of Mathematics, was one of the recipients of the Inaugural Outstanding Postdoc Mentor Award. The award recognizes a faculty member or advisor who has engaged in exceptional mentoring of postdoctoral scholars as evidenced by the following:
Has advocated for postdoctoral scholars.
Has been accessible and provided open lines of communication to postdoctoral scholars.
Has created a supportive environment for research; has shown respect for the postdoctoral scholars’ goals, and assisted them in fulfilling those goals.
Has provided guidance in research career and assisting the postdoctoral scholars in building a professional network through generous sharing of contacts.
Has demonstrated a sustained commitment to creating a productive working environment that enhances the overall postdoctoral experience.
The recipients were welcomed to attend the National Postdoctoral Appreciation Week luncheon on Friday, September 23, 2016 at noon, in the lobby of the FedEx Global Education Center. Each recipient will be presented with a plaque in recognition of being selected as an outstanding mentor during our Annual Postdoctoral Awards for Research Excellence in November. Congratulations!
J. Burton Linker In Memoriam
J. Burton Linker In Memoriam
Joe Burton Linker Jr, 92, born in Durham NC, raised in Chapel Hill NC, passed away on 7/21/2016. He was a resident of Carol Woods Retirement Community to which he came after having been away from Chapel Hill for 47 years.
Joe was the son of math Professor Dr. Joe Burton Linker and Ione Markham Linker. In 1944 he graduated from UNC-CH with a BS in Physics, and was then immediately commissioned as Ensign USNR. He received technical radar training at Harvard and MIT, and was assigned Pacific Ocean sea duty as radar officer on a naval cruiser as World War II came to an end.
Returning to graduate school after active duty he was an Instructor in UNC’s Department of Mathematics, while simultaneoulsy taking graduate physics courses, pending entering NC State Engineering School. In 1949 he completed his MS in Electrical Engineering and began his technical career at General Electric’s Electronics Laboratory in Syracuse NY.
Joe was honored to be made of member of Eta Kappa Nu, a member of Sigma Xi, and later, a Senior Member of IEEE. He was soon licensed as a professional Engineer in New York, and was a graduate of General Electric’s high recognized 3-year graduate Advanced Engineering “ABC” Course.
Jones New Kruskal Lecturer
Jones New Kruskal Lecturer
Congratulations to Professor Chris Jones for being selected as the Martin Kruskal Lecturer for 2016. The SIAM Activity Group on Nonlinear Waves and Coherent Structures, SIAG/NWCS, awards this prize for a notable body of mathematics and contributions in the field of nonlinear waves and coherent structures. The prize honors Martin David Kruskal for his fundamental contributions in many areas of mathematics and science, including his single most celebrated contribution, the discovery and theory of solitons.
The members of the selection committee were Mariana Haragus, Chair, Alejandro Aceves, Peter Miller, and Robert Pego. They wish to recognize you for your “outstanding contributions to the stability analysis of traveling waves and seminal work on geometric singular perturbation theory and spectral theory.” Their citation continues: “As an inspiring mentor of young researchers, he has made a mark in the applied mathematics community.” The prize will be awarded at the 2016 SIAM Conference on Nonlinear Waves and Coherent Structures, NW16, to be held August 8-11, 2016, in Philadelphia, Pennsylvania. As part of the award, he is invited to present a plenary lecture, the Martin Kruskal Lecture, at NW16.