 I'm Kevin Trumbull of the School of Materials Engineering. I'm here representing the department head Dave Barr, and I'm pleased to introduce Professor Maria Oknouski. She is an associate professor of materials engineering, and she also has a courtesy appointment in nuclear engineering. She's a fellow West Michigander. We actually grew up about 50 miles apart from each other. So she did her graduate work at the University of Illinois, and she joined us here from Idaho National Labs. She's an expert in nuclear materials and also in structural materials and their characterization at the microstructure level. So I'll let her tell you more about that. So she's made great contributions to our teaching programs, both at the graduate and undergraduate level. When our longtime professor, Dan Onda, retired a few years ago, she kind of took over the quantitative microstructure analysis course that's been a Purdue mainstay for many, many years, and she's done a great job with the undergraduate laboratory courses as well. She's had a remarkable number of undergraduate researchers in her labs over the years, so I'll let her take it away. Can you all hear me OK? OK, great. OK, so first of all, thank you very much for the opportunity to speak today, and thank you all for coming. OK, so with that, I will go ahead and get started. And so first of all, as Ivan barked upon this journey here, I firstly and foremostly need to thank my family and friends support along the way. And in the center here, I don't know if the pointer is quite weak, that's my parents there. And they've given me this backbone of basically hard work and perseverance and enabling me to pursue any sort of research or discipline that I was particularly interested in. They didn't push me one way or another, so I really appreciated that. And you'll see, I had a very nonlinear trajectory, and you'll see how that kind of comes into play. I also have two sisters and a younger brother, too, that also supported me quite a bit along the way. And I have four nephews that, as you can maybe see at the bottom there, I'm trying to recruit them to come to Purdue. I'm starting them very early. And then also, I have a couple wonderful brother-in-laws. And of course, my husband here, he's also an associate professor and associate dean in the College of Health and Human Sciences. He's actually taking his group out to lunch today, so he couldn't be here. But at any rate, he's been a tremendous support to me. And then, of course, our dogs. Those are near and dear to our hearts and great emotional support animals, if you will. So OK. So I included this picture here because not just because it's pretty. One, I am an avid scuba diver. I love scuba diving. I'm a certified rescue diver. But it also represents my trajectory, if you will, throughout my academic career. And the reason I chose scuba diving, too, here to indicate that is you really have to be able to control yourself in three dimensions. I was not even on a linear trajectory. I was actually going in multi-dimensions. And you need that buoyancy control for you to navigate around those coral heads effectively and actually see the macro and the micro fauna and flora. OK. So I started out as actually a marine science and biology major. That was my bachelor's degree. So here's where I'm talking about non-linearity, right? A very non-traditional path. I conducted this, my bachelor's degree, at the University of Tampa right in the heart of Tampa. It's a beautiful campus right along the Hillsboro River there. And my research interest was really peaked from the very beginning. I conducted research for four years with a faculty member, Stan Rice. And we were looking at barnacle colonization rates and adhesion strengths on various materials that the Navy had contracted him for. So we didn't know what they were. It was like material X, material Y, and whatnot. So I had to publish, I had published a four-year thesis and also gave a presentation. And so it was like material X, material Y, material Z, because we never knew what they were doing the comparisons. But at any rate, he had developed this sort of clever methodology to measure adhesion strength of materials. And he called it, for the barnacles, a barnacle meter, naturally, right? So every week we would head out to have the picture at the very bottom there of Davis Island. And we would go and count the barnacles, bring them back, and then check their adhesion strength, right, and chart that over four years, essentially. So one of the other things, too, that I'm passionate about is also preserving the environment. And so one of the things that I did as an undergrad was started the recycling program at the University of Tampa. So that's me down there. And yeah, that's black and white. I guess that's what it looks like after you get the scanned in version. They did have color photos then. So, but yeah, I actually dug this out last night. So, but at any rate, we actually had the president of the university out there helping paint some of these bins that we were doing our paper recycling in. So it was a great effort across the university. Okay, so now to the non-linearity. I have this jump, right, between my undergraduate and graduate experience. So now you see I'm pursuing my master's and PhD in nuclear engineering. Well, this had to do because with, I had four years basically where I took some time and worked in basically water quality testing and R&D. And in the R&D component, I had the opportunity to interact with a national laboratory fellow, the highest sort of echelon you can achieve at Pacific Northwest National Laboratory. And he was my mentor. He really kind of was a sort of a guidepost, if you will, for nuclear, right? He really showed me how interesting this could be. And then one of our other collaborators as part of the small R&D company too was from UIUC and he recruited me to come to graduate school. And so there I was. So I had a couple years to catch up on engineering classes. So I took longer than most students. And so it was kind of an interesting endeavor, but I was determined to do that. And I started out and my master's actually doing, actually, simulations, right? Which I'm an experimentalist, right? So you saw, right, the barnacles and whatnot. So, but that's what we have funding for. So it really opened my eyes to the simulation, the capabilities of simulation, but also gave me a deeper understanding of what was happening from the microstructural level that I could then apply to my PhD. So my PhD transitioned more to experimental work, where I'm looking at microstructural evolution that was a radiation induced in basically single crystal iron with and without helium to simulate different types of nuclear reactor regimes. Okay, so those really kind of set the backbone for where I am now today. And I also wanted to thank a number of different collaborators from Los Alamos, Argon, SCKC and Washington State. And also I was a charter member of the World Nuclear University too. So I traveled actually all over the world to conduct experiments at those entities. Okay, so that took me to Idaho National Lab, which is the United States only fully funded DOE any nuclear energy laboratory. And I became directly as a staff member. I was not a postdoc, I was directly hired as a staff member because I came in with previous existing experience too. And they really gave me a lot of freedom, allowed me to expand upon my interests in different realms. But because they're a nuclear laboratory, they had a lot of fuel-based research. So then I started turning my attention more to fuel-based research as opposed to structural and some of the waste materials that I was looking at in my masters and my PhD. So I worked on understanding connections between microstructure of nuclear materials and fuels and their mechanical properties. So this is an example of just optimizing some mechanical properties in a trisorget fuel. This is an example of looking at different types of fabrication methodologies and optimizing residual stress in uranium molybdenum fuel. And one of the things that's really advantageous about being at Idaho National Lab is you can see in the top left-hand corner there, that's the advanced test reactor looking down into the core. So you see that chair and cove radiation there. So it is the most, or is the largest reactor that we can use to test materials in the United States. And so that opened a lot of capabilities for me to propose different types of experiments too that were not available before. And by the way, these are extremely expensive so you need the sort of support at these national labs. They also have amazing fuel handling facilities because this stuff comes out of the reactor and it is hot. I can't just reach over and touch it. Not physically hot, but radioactively hot. So we need to work in these sorts of hot cells that are shown here. That's pretty unique to Idaho National Lab too. And then finally, there was a nuclearization of some of the different types of techniques. Meaning they were shielded, for instance, we could use electron microscopes or focused ion beam combined with an SEM to enable us to pull out some really, really small specimens that we could then take to some of the user facilities. They became, now they weren't as hot, right? They were below the thresholds that needed to be accommodated within the particular user facilities. For instance, at Brookhaven at the advanced photon source at Argonne. Okay, so we continue here. This was kind of setting up some of the work that I've done here at Idaho and also continuing my graduate students now have picked up some of the work that I'd laid the foundation for at INL because it takes a long time to actually design these experiments, the irradiation experiments to actually being able to characterize them sometimes a couple years, sometimes a decade, sometimes multiple decades. So this fuel down here that I show at the bottom it's uranium zirconium fuel. That's nearly 30 years old now. That was my first PhD student that looked at that. So, and that was so hot, right? That was the coolest sample they let us remove from the hot cell to provide perspective. So, how did I make this sort of transition between Idaho National Lab and deciding to come to Purdue? So, I'd had a lot of people throughout my career say, oh, maybe you should become a faculty member, right? And I was like, no, I love the National Lab. At that point I'd worked in over a half a dozen of them across the world and I really liked my position and my flexibility at Idaho National Lab. But I never lost that student engagement. As soon as I started there, I was working with universities, working with graduate students from a number of different entities. By the way, one of these students is probably one of my closest collaborators right now, interestingly. And then I also decided, okay, I'm gonna try my hand at course development and teaching. So, I worked with one of my collaborators at INL and we co-developed a course on nuclear materials too. So, that allowed me to really kind of test the waters and the opportunity presented itself. And so, my husband and I came here to Purdue University. And I started as an assistant professor in 2016. And as I mentioned, we were laying that sort of foundational work to enable my current graduate students and recently graduated graduate students to be able to continue to pursue some of the microstructural evolution studies of these nuclear fuels, for instance. So, on the right-hand side here, we see this sort of 3D phase, avoid evolution of neutron, irradiated uranium zirconium fuel. So, this was something where we took those little, tiny cubes, those 50 by 50 micron cubes I showed you that were pulled out by a focused ion beam. They were cool enough. Now, we could take them to APS at Argon and then do some tomographic imaging. This provided unprecedented insight into the three-dimensional microstructure that was never known. We had no idea the complexity of these systems until we could take a peak three-dimensionally. So, Argon also liked that. That actually ended up on their front page of their website. And so, we were pretty proud of that. That was my first graduate student, Genova Thomas. And so, those different colors there indicate the different phases as well as the different, the porosity that's present within those fuels. One of the other kind of cool things that we were able to do, because we had access to neutrons, right, these nuclear reactors is this 4D, I'll call it quasi-4D microstructural evolution, we were able to examine the same microstructure before and after it was actually neutron irradiated. Pretty darn hard to do because you're trying to do this years apart, you have to have appropriate fiducials and think you can get back to that same point. So, that provided us some insight too in terms of how precipitates can evolve in structural materials. And it's much more complex again than we initially thought in terms of we have nucleation and growth. We have basically shrinkage and dissolution. We have ballistic dissolution from the bombardment of the neutrons and growth of reprecipitation. So, and then finally, this is an ongoing project, if you will. One of the other things I'm highlighting is the uranium-zirconium phase diagram. So, we think, oh yeah, phase diagrams, that's easy, right? We know all of these. No, we don't. We realized nobody agrees on the uranium-zirconium phase diagram. And so, we have been doing some in-situ neutron diffraction at Los Alamos and one of my recent PhD students conducted some of these experiments and we're collaborating also with Edwin Garcia in MSC to do machine learning. And now we've come up with a new phase diagram. I didn't put it here because it's not published yet. But that's coming out soon. So, all of these entities here, I'd just like to thank them because those are important user facilities that we go to and conduct our research at. And then, learning and engagement. So, as Kevin mentioned, I've taught a number of different courses here and ranging basically from our intro class which is shown here on this left-hand side. Interestingly, that was understanding the connections between processing and microstructure of ice cream. So, this was actually the first lecture that previous Dean Meng Cheng actually came to. He wasn't, he was a little too busy to stay around and wait for the ice cream though. So, but at least he came. So, it was pretty exciting. And then, this is actually, this is a class that Kevin was just mentioning in terms of the quantitative microstructural analysis. I created a kind of a fun exercise where students are actually using ASTM methodology to determine volume fraction of phases and they get to use candy bars. And so, we do that right around Halloween. So, it's a nice appropriate kind of combination. And then, this is just an example of one of the lab courses that I've taught too. So, the students get to drive their own SEM. And then, of course, here's my little puppy helping write lectures. I mean, he is named after Otto Hahn. So, naturally he's gonna help write the lectures, right? So, and then for engagement, these are some of the ongoing things that I currently have right now. I'm the chair of the user group of the Nuclear Science User Facility. I'm on the user's executive committee for NSLS2 at Brookhaven, for ANS, the Material Science Technology Division Executive Committee, and MINES, which is coming up in about a week and a half, is I'm the co-technical chair there too, and I'll be the chair in four years. So, and then finally, this is just snapshots of our research group kind of in combination of doing research and fun things. We like to combine both. That is a much nicer environment, of course, to work within. And the other thing I was gonna mention too is there's a combination of both undergrads and graduate students shown here. Okay, and then my current grad research group, actually are all these ladies here. They're all in the audience, so thank you all for coming. And then Nate is gonna be joining us in January, but I do want to basically to echo the sentiments of the previous faculty member too. The graduate students and the undergraduates are the ones that do all the work. So thank you all for your hard work. Thank you to those that have already graduated and moved on to other jobs. So, and as you can see, many of them are fellows, various types of fellows, Fulbright, UNLP, NSF, for instance, and have won some other accolades as well. So they're very successful. And then finally, my mentors and funding agencies, I'd like to thank them. So this is Dr. Rice. He was my Barnacleometer developer. And then Dr. Ron Brzezinski, he unfortunately has since passed away, but he was my real inspiration into getting into nuclear engineering. And then Professor Miley recruited me to UIUC, my PhD advisor, Jim Stubbins, who I can always just knock on his door or email him and he's an excellent resource for me, Stumolloy Los Alamos, and then also Elliot and Leah, who are my mentors here. So thank you all for supporting me. And then finally, of course, I have to thank all my funding agencies too, because we obviously need our funding to support our students. And with that, I thank you all for coming and I'd be happy to take any questions. Is that still on? Any questions? Two questions. The first one is, so from marine biology type of major into nuclear engineering, the background is very different. What is the hardest thing you face, you face that it goes through the transition successfully? Right. I think the hardest thing was, I mentioned I spent four years out of academia and getting back into the rigorous study regime was probably the most difficult aspect. My math was very strong, but it still took a little bit of time to basically transition back in. So yeah, it was just re-adapting and re-balancing my life. So yeah. Yeah, the next question is a more technical side. How do you keep the ice cream microstructure stable when you're under the microscope? How do you keep it stable? You put it in a freezer. So this one, they cheated basically, they had used liquid nitrogen too, right, to cool the system. So I think you could see the doer that was sitting on the floor. I don't think I'd crop that part out. So yeah. Thank you. Yeah, thank you. Hello, Professor Maria. And first of all, congratulations to all your achievements. As you stated, you had your majors as marine science in your bachelor's, and then you switched over to nuclear engineering, or like atomic physics during your PhD and your master's. So again, as stated before, this is a dangerous transition if I was in your position, but you took that jump fearlessly. But what made you realize that, you already took a jump? What made you realize that, okay, nuclear physics is going to be my forte, and I'm going to build a career out of this? I mean, what prompted you not to take another jump is my question. Like why did you stick on to nuclear physics? Okay, this is going to be my main domain from now onwards. So thank you for the question. So it's a great question, right? Because it is a bit about finding out what resonates within ourselves in terms of our interests, right? And for me, it was a stepwise process too in terms of, okay, well, I'm going to get my master's first, see what this is like, see if this fit is right for me, right? And you can see, right, I transitioned too from the modeling to the experimental, so I'd back to my true self as an experimentalist. So, but like I said, I just kind of took it in a stepwise process, and by the way, for nuclear engineering, we had to complete a master's and then a PhD. There was no fast track to a PhD either, so it also gives people the opportunity to develop their skills and their interests too. So, yeah. I think we're ready to move on. Thank you.