Ayyana Chakravartula and Catherine Sheane on Careers in Engineering

Transcript:

I always did have as a child an interest in wanting to understand how things work and that way that manifested was I took a lot of things apart and I made a lot of things. I do remember in elementary school really getting into the scientific methods for the investigative aspect of it trying to come up with how you thought something was going to turn out. Hi, welcome to the science fair podcast. I'm your host, Susan Keatley. I'm a PhD chemist, writer, and I love talking to scientists. On the science fair podcast, I aim to bring you conversations with scientists doing fascinating, cutting-edge work on all kinds of interesting phenomena, ranging from physics, to chemistry, to biology, and even the nature of science itself. Tune in every Monday for a new episode. For each scientist we interview, first we'll release a mini-episode that connects what the scientist is doing with what's happening in the high school science classroom and then the following week, the full-length interview. So come along and tune in for some science fair. Hello listeners. Welcome to another episode of the Science Fair podcast. I am so thrilled to welcome to fantastic engineers to the podcast today. We have Ayanna, Shaka Bartula, and Catherine Shane, also known as Cat. Ayanna is the failure analysis and strategy lead for the devices and services organization at Google. She leads a team of science detectives who work to understand why things break and how badly they are breaking and basically how our phones and other devices do when people use them in general. The team looks at phones and watches and other hardware that Google makes at all stages of development from prototyping to the field. Before working at Google, Ayanna held positions as a research scientist in engineering consultant and a lecturer at several institutions. She co-authored a textbook on the mechanics of bio materials. She also spent two years teaching eighth grade math as a Teach for America member in New Orleans, Louisiana. Ayanna earned a bachelor's degree in aerospace engineering from Princeton University and a PhD in mechanical engineering from the University of California and Berkeley. Cat is the vice president of environmental, social governance and sustainability at Parsons Corporation. She's responsible for the corporate sustainability strategy at Parsons and leads the client facing sustainability and resilience team in North America. Among her specialties is guiding interdisciplinary teams through climate risk assessments and third party sustainability certifications for large complex civil infrastructure projects. Cat is a passionate sustainability champion with 24 years of experience leading sustainability strategy development action planning and execution of the corporate and project levels. In addition to her time at Parsons, Cat was the sustainability director at Estorino, a Pittsburgh based architecture firm, followed by a role as assistant vice president working in sustainability for PNC bank. Cat earned a bachelor's degree from Princeton University and a master's degree from Carnegie Mellon University, both in civil and environmental engineering and holds a professional engineer's license as well as envision SP and lead APBD+D credentials. And I hope we will get into what those letters mean in the podcast. And full disclosure, Iyana and Cat and I were in the same Acapella singing group in college, the Princeton University Tegressions. I do not think we will be singing on this episode, but you can find our music on available music platforms. You can stream it. Iyana and Cat, welcome to the show. Thanks. Thanks. I wanted to be here. Thank you. So I am going to ask a whole bunch of questions and I think I'm just going to alternate who I ask first and we'll just kind of take it from there. So Iyana, I wanted to start with you. Could you tell us about your path to pursuing a career in science and really maybe share some experiences in childhood in both school and life that sparked and cultivated your interest in science? Yeah. So first of all, I just want to say how fun it is to be on this podcast with people that I have known so long and actually like that we didn't even really know each other as people interested in the sciences. So this is kind of funny to have this conversation when I feel like we could have a long conversation about music. But your question about my path to a career in the sciences, I think for me there were a few options. I was very interested in becoming someone who cuts hair and that's something I thought about a lot. I was interested in becoming an astronaut and then I always did have as a child an interest in wanting to understand how things work and that way that manifested was I took a lot of things apart and I made a lot of things. So we did a lot of I think what you would call now very heavy crafting. So a lot of ceramics and weaving and sewing and designing clothes. I I um I showed my own formal stresses in high school. We sewed our own stuffed animals just like a lot of creating of things in a way that now you know with my own children. So I have three boys ages 12, 14 and 17 and I see them having the opportunity to design things with CAD and 3D print which we didn't of course have when we were that age. But I think those interests led me those were all they were like side hobbies. Things that I did just in my spare time in addition to reading just a ton of books. I was always a reader. But when I started looking at colleges it was really my high school guidance counselor who suggested that I applied at engineering programs which I don't think I was really considering that seriously up to that point. So sometimes when I talk to high schoolers now I'm like I don't know that you need to know as a high schooler what you want to do with your job. And I still think that is still my position but it is true that I didn't like going to engineering as I call a student and then have worked in engineering pretty much since then. I love the term heavy crafting. Like is that like what a maker is now? I feel like I'm not sure exactly like heavy crafting but that's amazing. Yeah it is I did not know if the maker term would translate on this podcast but yeah I would say it was a maker who was always shy to weave together different things and different media and build things out of them. How about you Kat? I would say that what led me to pursue a career in in science is punctuated by a few different I would say mostly academic moments that I can think of. I do remember in elementary school really getting into the scientific methods for the investigative aspect of it trying to come up with how you thought something was going to turn out and then testing the hypothesis to see whether you could confirm or deny it or maybe even come up with a different result altogether. So I really enjoyed that and I think in junior high when I was getting into pre algebra and algebra the solving for X I think is representative of like something I realized about how my brain works and really wanting to find the answers to things but having a process that you follow to try to get there. So there was a systematic way of thinking that was solidifying for me at that time and then and then I think in high school something that drew me towards the built environment which is where the the majority of my work is today was an architectural drafting course that I took at the the career center what was then the career center in Arlington Virginia which was a location outside of high school that had courses weekly usually courses for in a variety of topics on a variety of topics that you know might not be available in the actual individual high schools in the county. So I took this drafting class and while I didn't know it then and I didn't go into college planning to major in civil engineering or architecture for that matter I do think that that kind of spatial learning and planning of where to put things and how parts and pieces fit together when you're building something physical was another critical or foundational aspect of leading to where I am today. What did you think you would major in when you started college? I put on my applications that I was either going to major in French or chemistry. I loved chemistry in high school. Yeah, Iana and I were having a conversation over the weekend about Avogadro's number and orbitals and how awesome I thought all of that was and then I took one chemistry class at Princeton Turbo Chem you may have heard of it too. Yeah that it wasn't amazing. It it I think two two classes in I said to myself chemistry is not the major for me I need to find something else. So that's when I started taking architecture courses and spoke to my advisor and realized that the engineering space was probably where I would thrive and that turned out to be true. And when I applied I applied to Princeton for engineering. I didn't even know what engineering was, but the law was like, you'll get a good job. I mean, come on. So I'm sure you do, but like, that wasn't a good, there were a series of classes just one after another where I was like, I, this is not the right fit. So I think like to your point, Iana, what you think you want to do in high school often doesn't translate exactly to what you end up doing. - Don't shut it. I mean, what are you, you're 17, you've not seen a lot. Like, I always think about that with my job that this company didn't exist, the field that I'm in. I didn't even know about until after grad school. So how can you know? I mean, I guess that's maybe a wonderful aspect of this podcast is telling people about jobs that they may not know exist, but I mean, I didn't know this job existed. - Did you end up assuming majoring in chemistry? - I did, but then senior year, I got really interested in archaeology and I did an archaeological chemistry, senior thesis and then went to grad school for anthropology. So I was kind of like all over the place. The one thing I will say is that when I was a kid, I made up my own radio station, which I feel like was kind of a precursor to podcasting. - Yeah, so we're doing it now. - So Kat, after graduating, tell us what you did and then how did you decide to go for a graduate degree? And what was that like? - After graduating, I went straight, well, that's not true actually. I applied for a fellowship program in France. So I still did stick with my love of the French language and culture, even though I did not major in it in college. And I found an opportunity to go to an engineering school, a program put on by an engineering school just outside of Paris called the Econopodi Technique. And they were at the time looking for a way of exposing foreign trained engineers to the French engineering educational system, because that particular school was actually a military school. And so long story short, I spent a year in France doing six months of course work and then an internship after that. So that was the first thing I did after school. And that was amazing. I came this close to staying in France, but I wanted to get my professional engineers license in the US and you need to work in the United States for that. So I came back and I went to work at Parsons, which happens to also be where I work now. But my role at that time was as a structural engineer. So my job entailed a lot of field work. So going out and actually looking at structures and evaluating their condition in these regular inspections to advise owners how to better maintain their assets so that they continue to be able to perform the service they were intended to, like crossing rivers or highways or tunnels or things like that. And what got me to, I really enjoyed that work. It's a very nerdy kind of specific job focused on calculations and drawings and seeing how those things actually get built in the real world. But what led me to my desire to go to graduate school was that I wanted to integrate an environmental component into the infrastructure engineering background and work that I was doing at that time. And I would say that when I was thinking about this, the disciplines were relatively siloed. So environmental engineering was a very specific thing related to water quality and air quality and remediation. And civil engineering was like, OK, let's build bridges and tunnels and roads. And yes, you want to make sure you're treading lightly on the environment, but rarely were those two disciplines integrated. So I was looking for a way of putting those two passions together because I really wanted to be a good steward of the environment, not just in my personal but in my professional life. And so I started looking for programs that had sustainability and environmental components built into a civil engineering curriculum, which was actually quite hard to find. I think it's a lot easier now. Architecture programs did have a lot of sustainability specialties built in because of green building, which was very prominent at the time. This is around like mid 2000s. But the main reason why I ended up at Carnegie Mellon from my master's degree was because they had a sustainability or a green design sub-specialty within the civil and environmental engineering program. And I really wanted to be able to make a shift quickly. And it didn't feel like the staying in the industry was the right way to go. I thought that additional education was going to be what really propelled me in the direction I wanted to go. I would just like to jump in here, though. One of the reasons that cat is the coolest engineer is because she can do it in multiple languages, which is not standard, I think a lot of people. Engineers don't do a lot of study abroad, right? You're like so much coursework. Most people don't get that chance to learn it and do it in other languages very hard. And secondly, because when we were all out of college, cat is sending photos standing on top of bridges. You know, she's even spec'd them with your eyeballs. She's not doing something remote. She was climbing up the cables. It was incredible. That's super cool. I love that perspective, Iana. That was really fun. I will say I miss the fieldwork in a lot of ways. And I know we'll probably get into what our day to day is now, which is very much not climbing on bridges for me anymore. (laughs) Iana, what led you to go for a PhD? And what was it like being a graduate student? So after college, at the end of my undergraduate, I was very burned out. I don't know how you all felt, but I thought, you know, we were pretty hard. We did have a lot of fun saying, but also just the engineering side. It was intense. And so I didn't think that I wanted to go to graduate school, but I didn't know that it would be the best choice for me at that time. So I had committed to doing Teach for America with Will, who's my boyfriend at the time, and is now my husband. And I knew that we were going to go to Louisiana for two years. It was a two-year commitment minimum. And so then I had done some internships in college. My college advisor, my parents, everyone seemed to think that graduate school was an ex-logical thing. And now having gone through, I don't disagree. I do think it's important to go through and get some specialization if you want to work really deeply in one area. And for me, also, I knew I was going to transition fields because I had done my undergraduate and aerospace, and I didn't intend to work in aerospace the opportunities at the time where maybe more weapons-based weapons design, the stuff that I wasn't that interested in. So I knew that I was going to try to generalize a little bit into mechanical. So I was going to have to do more school. So I ended up after Teach for America coming to Cal, studying mechanical engineering and focusing in biomaterials. And I was a little bit worried about maybe being out of practice. And maybe-- I don't know if you felt that way also, because you worked in psych-- being in school is a completely different thing from working in a discipline. And then I was working in a completely different discipline, anyway, teaching. But I was worried about the transition back. I was worried about switching majors. But it all seemed to work out. There's-- I do like school. So I think that was probably returning to something that I enjoy. I am a big nerd, as you can tell by the fact that Kat and I were talking this weekend about a God knows number. So the school part was really fun. The lab work, the hands-on work that you get to do in the things I was doing that I really enjoyed. So yeah, Cal was wonderful. It was a great experience. And also, I think it showed me how different schools teach engineering differently. So as an undergrad, we learned things within one framework. And it's all engineering. I mean, there's an accreditation. So the universities are teaching similar things. But the schools themselves have a lens on the way that they teach things. And for example, I took a material science course as an undergrad that just didn't really click for me. And then I ended up when I went to Cal, taking it again with several different professors and the different-- probably a whole different look at it. And I became very deeply interested in it. So it's like these topics can be taught different ways. And you might latch on to one institution than another. After I was in the other-- the anthropology department for two years, I switched into chemistry at the University of Wisconsin-Madison. And I think because I was older, because I really had a goal. And also, the department was very different. It was a completely different experience of learning chemistry. And that was fascinating to see. Yeah, and I think that's kind of wild, right? Because that's where I ended up then doing a lot of my work. And if I had just based that off of my experience as an undergraduate, I would have driven a different field. I would love for both of you to talk about a day in your life as an engineer. And you can pick a day in your life at any point over the past 20 years or so. Just kind of maybe please clarify what that was and what that looked like. Because I think I kind of think snapshots of careers at different times are fascinating. I don't know. Why don't we start with you? I'll start with my current job, but when I had just joined the team. So when I came into this job as a hands-on lab engineer, my day would be-- well, first of all, I would start with a very long commute. I don't know if you know this, but I live about an hour and a half from where I work. And I have to go in. It's a lab situation so you have to be there. So I would start with a very long commute. But what I like about that is that I use that time to catch up on things that were happening with our team in Asia, things that had sort of happened. Well, we were asleep to get set up for my day so to really set out what the priorities were. So by the time I would get to work, I was very organized with sort of the things that I needed to accomplish with the time that I had. So I would get in. We deal with what's called hardware failure analysis. So devices can be failing at any point in their life cycle, whether it's during development, whether it's in the field. And so our team is called in basically in a case-by-case basis to look at things that are breaking. So, um, In my day, typically, I would either have some open issues that I was dealing with. And so that would involve physical taking a device, opening it up, looking at it under a microscope, maybe doing some analyses to figure out what's happening compositionally to some of the materials in the device, using all these different techniques that we have available in our lab to basically figure out, be a detective and figure out what went wrong. In addition to that work, I have to talk to the team that brought it in to understand what they're concerned about. So it's actually a lot of working with people, talking to the teams that have the issues. There's a fair amount of writing afterwards so like any good scientist doing an experiment, I'm writing up the background, I'm writing up what I saw, I'm writing up conclusions and recommendations and little small things that we can test to see if we're right. And so my days, in those days, it was always a combination of lab work, talking to teams about the work and reporting out. And I really enjoyed those things. And then I would have my hour and half commute coming home. And I would use that to do a lot of the writing and thinking and I feel like I would call it almost like special study time where I would be like not understanding something I had seen and kind of do an investigation to the literature to understand a material or something I was seeing in the analysis. - Because you were on a bus? Is that, am I remembering this correctly? Yes, so you weren't driving for any of this. - I'm not driving, oh yeah, yeah, yeah, yeah. - I do that work. - And very clear, I'm on a Wi-Fi enabled bus during that commute, yeah, not like studying, well, driving. - I'm gonna combine a little bit of the next question to consolidate here. So what about that time that day in the life was surprising to you? - What has been really fun for me about this job and this team is how interdisciplinary it is. So it's never like, I'm a, you know, for example, in graduate school, I only did nano indentation. I only looked at one plastic polyethylene and so that was very specific. I was learning all these things about this one technique and maybe small modifications to the plastic and the work that I'm doing now, it's like there are no limits. I, in those days, I was asked, you know, as often to look at a chemistry aspect as I was an electrical engineering aspect. And even though I had touched all of those tools, probably an undergrad in grad school, in the intervening years probably hadn't used them very much. So it was really expansive getting to run the scanning electron microscope, getting to do things that maybe in a bigger team, we might have set people doing things. Instead, you, in our team, you get to do them with your hands. - How about you, Kat? Can you tell us about a day in the life, including things that you enjoyed and thought were fun and also things that maybe were surprising? - Yeah, it was hard to pick a particular day because the roles that I've held have been quite different from one another, you know, ranging from the early part of my career when I was out in the field a lot to now where I work from home and, you know, 90% of my job is actually not technical, at all. More people management and reading and writing. But I kind of settled on something that was sort of in the middle. So when I lived in Pittsburgh, Pennsylvania, and I was working at Asterrey-No, which was an architecture and engineering. So big A, little E firm. My day started with a bike ride. So I used my commute at that time as a way of not thinking about anything relating to work and just being in my body and getting to and from a place without getting hit by a car, (laughs) which I think I'm gonna shake it. It wasn't really that risky, but any cyclist knows. You gotta keep an eye out for the automobile drivers who don't like you. And then I think upon arrival, there was usually, as we all have, you know, some email, correspondence. It kind of setting up your day, seeing who's asked you for things, looking at your meeting schedule. Because as one progresses into more managerial, stage of the career, the meetings they tend to stack up over the course of the day. But at that time, I would have occasional meetings, check out who I had to talk to, what I wanted to accomplish with it. And then the actual work itself, I would say, was divided into concentrated analysis. And as a sustainability director for the firm, we were looking at how do we execute green building designs and construction practices that support a client's overall sustainability objectives. And so if we were at the early stages of design or the conceptual process that analytical work was looking at all the available information, understanding the client's priorities, and developing a set of strategies that would align with those priorities. And the type of project that it was, is it a hospital, is it a retail construction, is it mixed use with residential and stores, just to align what you were going to do with the needs of the actual built end product. And then another category of work was coordination. So I could come up with what I thought the best strategies were or the sustainability team could, but then we had to talk to the architects, the landscape architecture, the mechanical engineers, the electrical engineers, the client to validate that these things are even possible through the individuals with that subject matter expertise, and then confirming that it rolls up into what our client was looking for in the end. And then I would say the last aspect is similar to what I honestly documentation, because you can have all these conversations, but if you don't write down and create action items and assign roles and responsibilities to people, you have no way of confirming that everyone understands or left the meeting with the same conclusion, as well as a way of tracking progress as you move forward. So analytical work, coordination, documentation. I think it's interesting that both of you as engineers work so much with other people. And it sounds like you need a lot of different people to agree on something, to buy into a plan, and then the writing of it. So I guess, is that something you would have thought of when you were declaring your major as an engineer, or did you think it might be more solitary work? - To your earlier question about what was surprising, I do think that the, as far as the coordination component is concerned, I think that my undergraduate education did emphasize collaboration. So I think that was one good thing. We had a lot of group projects, especially in our senior year. We were never really working in a vacuum on our own. Now one thing I would say was surprising, and I don't know if curricula have changed since we graduated, but the amount of writing, technical writing, and other types of writing that are part of an engineering job, I think was a bit surprising to me. And when I see the individuals I have worked with over the years at more junior levels, I'm not sure that their programs are preparing them for that either. Because doing the analytical work is one thing, but translating it into a form that is succinct and clear for a non-expert audience is a very, it's a very valuable skill, and it's also one that needs to be practiced, I think, because the way I would express something to a fellow engineer is not the same way I would express it to a customer who doesn't know the true nuts and bolts, nor do they care in a lot of ways about the true nuts and bolts. They want to know how it affects them and how they can use that information to make decisions. - Our most little cost. But I think that's the trajectory, right? Is that you're in school, you're learning the content knowledge, and I do think I agree that our undergrad and my graduate experiences talk a lot about collaboration and encouraged communication. They probably could be doing more, but the content stuff is important. And then when you're in the working world, then you start to learn the dependencies where you're like, "I actually do need to be able to talk to this team in a different way," or they're not just gonna take my giving them a spreadsheet of data and make a decision, right? You have to advocate for it and learn how to do that gracefully. And so to me, that makes sense as something that you pick up along years of working in industry, or I'm sure in other fields as well. So I would love to now do kind of like a specific example. So I'd like to ask, can you tell us about a time there was a scientific or engineering challenge? What was the challenge that you had to solve? What made it hard? And I guess this kind of dovetails with the last question, like how did you get a group of people to kind of agree on the approach? Iana, how about we start with you? - I'm gonna take it way back to one of my first jobs, which was at Cambridge Polymer Group, which is a contract research lab. And I guess at the time it was in Boston, and now they do a little bit outside of Boston. But my job at the time there was to work on developing, initially it was working on developing tissue substitutes. So artificial cartilage cartilage is like an extremely difficult material to replicate in a synthetic way, because it has this really intricate sort of layer structure, and it's both tough and strong, but soft and flexible. And it kind of, you know, so all these things make it really hard to just put a single material in there and expect that you would get the same behavior. So we had started by working on an artificial cartilage, but then what that led us to was the desire to characterize cartilage better. Because we realized that the techniques that we were using to characterize a simple hydrogel, or maybe a tougher engineering plastic, you couldn't use on this material, because they're responded in a way. or like aspects of time were important in the way it was hydrated and held. So there was nothing really, there wasn't a tool that really existed for what we wanted to do to characterize cartilage. And so my team worked on developing a characterization tool. And because we were a small company, I had the opportunity to both work on the CAD, buy and make the parts, but also to write the code that ran it, which I hadn't done before that. And so I learned a lot about coding. And basically we built our own tiny load frame, which if you've been an mechanical engineering lab, you've seen those, they're like these, you probably worked with them. Things that can push or pull on a material, and they can measure both the distance and the force that's involved. And then you can use that through various calculations to understand stress and strain. So we got to do that. And it was, that project to me was so satisfying because it was beginning to end. We came up with the need for it. So we had a really clear thing that we needed. We had control over all of the different aspects of how it would do it. And then getting to write, I don't know how much coding you've done, but a lot of times, I think that's where you feel like you're really controlling things as when you write code. And then the machine does what you want. You're like, I have done it. And I think the thing that was really fun about that for me is that it was a huge problem. We did have to understand the cost of it, to understand if it made any sense to even do it. And then in the end, we have this little working tool which is very satisfying. - I had a hard time thinking of a specific instance. I would say in our team right now, one of the challenges that we have that's ongoing is it's less of a problem to be solved and more of a communication of an approach. And I'll see if I can explain what I'm trying to say or what's in my head. When we talk about risks associated with climate change as they relate to something in the built environment, there's not a manual that just says, this is the type of thing you're building. This is where it's located. These are the hazards and these are the risks. Everything is tailored to that. All of the specific circumstances of that particular project. And so I would say climate risk assessments are still, they're certainly not required by code or law in most jurisdictions. Our clients understand that they should probably be thinking about this because if they don't then further down the line when their project is in the operational phase or the service phase, they could experience disruptions that are both could cause safety problems but also cost them a lot of money to repair. So I think the challenge that we have and that we are kind of solving on an ongoing basis is how do you take a set of data and a project type come up with a reasonable set of recommendations that aren't necessarily going to be like the exact right answer. So growing up, the solving for X or the, you know, the scientific method I guess isn't necessarily like as linear a to be type of thing but conversations around risk are challenging because there is no one correct answer. And I think as those of us who are trained as engineers sometimes wanted to be or are taught that there is a one right answer. So I think I haven't figured out the solution except to continue to think and analyze and talk and make and document assumptions so that later on if the assumptions change you can adjust your analysis. So I think it's an iterative process rather than like a single challenge that has a single solution. - Yeah, I think that that is like exactly, you know, I didn't give that example but I think like when I think about things that are really challenging, it is because they are there isn't a right answer. And there are a lot of unknowns. And so you're both modeling, you're using your engineering background, you're using some intuition and at some point landing on a recommendation which is basically go or no go. And then you have to see how it proves out and then you have to adjust the way that you do these things and oftentimes you're doing them kind of live, you're doing it and stuff is in the field from a previous time and you're sort of having to adjust all of the time. And that's something that you do not learn in school because in school you are basically always heading towards like this is the answer, this is the answer, this is the answer. And Kat, I love how you relate it back to solving for X because there's such satisfaction in that. And I'm sure it can be so frustrating. Also, I didn't realize that a climate risk assessment, there's gonna be like so many idiosyncrasies for a particular situation. That's really interesting to me. - Yeah, just, you know, there are certain things that are relatively easy to categorize like what region are you in, what's your proximity to water? But then the availability of climate data varies by region and so yeah, your assumptions are in a lot of ways dependent on what models maybe other people have done in that area. So yeah, it's just trying to fill in the blanks as best you can and document when you assume versus having a reliable source, if you will, but even climate data or climate projections are just projections. They're not predictions. And historic data are not necessarily predictors of what is to come. So just a lot of moving parts. - I would love to connect your work to something that students might learn in a high school science classroom. And, you know, I always say high school science, but it really could be like an advanced middle school classroom or like an introductory college classroom, but some of these really basic concepts in science. Ion, can you think of something that you've worked on that relates to something that high school students are learning and thinking about? And they might be saying, why do I need to know this? - Yes, I have actual students who ask me that in my household frequently. I do find that what surprises them, but doesn't surprise me at all is that I still do use a lot of science and math. Even now, even when I am not in the lab every day, I am using a lot of science and math. So I flipped through the next generation science standards and I found the one on material science, which is called matter and its interactions. And there's this concept with materials called structure property relationships, which is that the microstructure of a material, so a metal, if you get in really, really close, looks one way, a plastic looks a different way, a ceramic with a red glass, look a different way, and all of those, the microstructure of them contributes to the way that they act at the macro scale. So different plastics, or let's say this is the same plastic. So the chemistry is the same, but different amounts of crystallinity or different molecular weights are the difference between a wax in your candle, like something which you can kind of smush with your hands and melts really easily to the kind of plastic that's used in your skis, which is something which is rigid and strong. And so that all has to do with structure property relationships, which is part of what you can study in high school chemistry right now. And Kat, how about you? What's something you work on that relates to what students might be learning? The example that I came up with is related to the earlier part of my career when I was out in the field doing structural inspections on steel and concrete-based structures. So corrosion is one of the leading causes, maybe the leading cause to structural degradation in bridges and tunnels. So corrosion being this gradual degradation of a material usually a metal that is resulting from a chemical reaction between the material itself and environmental conditions to which it's exposed. So water, obviously, also air, oxygen, and sometimes pollutants or other chemicals that might be introduced into the environment. So rusting steel or iron, the reddish, flaky substance that you see appear on the surface of that metal is an example of corrosion. So how it relates to structural engineering is when you design a steel structure, one of the key components to that design is the coating system. What are you going, you can't just build a bridge out of steel and then not put anything on the surface because it will rapidly deteriorate or more rapidly deteriorate than if you apply a coating system. That could be a paint. There's some more sophisticated coating systems that are usually three layers with different chemical compositions, basically to prevent or slow down the intrusion of air and water. And in the case of a lot of transportation structures salt in environments where there are harsh winters and ice and snow that you want to melt, the substances that are used to remove those, the ice and snow from the road are corrosive to the structure typically. And that's another reason why with concrete structures, when you have steel reinforcing inside, you need to have at least a certain thickness of concrete over top of the steel because concrete doesn't operate well in tension, which is another concept that students might learn about in physics class. But that means that concrete when you pull on it is going to crack. The steel reinforcement on the inside is kind of what keeps it together. But when the concrete cracks and water gets in, then the steel can corrode and break off bigger pieces of the concrete. So corrosion is definitely something that engineers are highly aware of, structural engineers, when they're designing things and need to take it. to protect from. - Concrete is not impermeable to water, right? - So I would say, yes, it is unless it's cracked. So the matrix of Portland cement, sand, aggregates, and mixtures, it has porous components, but it's only if there's a crack can the water sort of travel through the matrix. - I was thinking about how you can set concrete in water. But you're right. - Okay, okay. - Yes, you set concrete in water because the water is needed to catalyze the chemical reaction that makes everything turn solid. - Iana, with microstructure, I just thought of this, was there ever a time where you discovered that something was breaking or not working, and maybe just a adjustment of the microstructure or the replacement of the material would fix it? Can you tell us about that? - So that happens all the time. So when a material is cracking, there's basically three ways to think about that. There are flaws in it, like actual manufacturing flaws. So starter cracks or dings or something, which you can only inspect and look for and sort of say, like if it has a flaw bigger than this, we're not going to include it. And that depends on your inspection method. There are materials, the microstructural things that you can change, and then there's the design that you can change to put it under less stress in the first place. Those are sort of the triangle of how you can figure out. You can adjust one of those three things to solve your cracking problem. Like you can look for smaller flaws, you can make it less stress, you can fix the material. So if you want to focus on fixing the material, if it's a plastic, for example, you might say, can I give it a longer molecular weight? So plastics are these strings of sort of chains that are all the same, and they can be shorter. They can be long. If they're longer, they are stronger. They will entangle more. The plastic will do a better job under load. So when you mold things out of plastic, and if you do that poorly, it's very, the one of the most common degradation modes is that the chains will get shorter. So if you just have a plastic, and you do a bad job molding it, there's molecular weight degradation, and then the thing cracks really easily. And so what you do in that situation is you actually just do a better job molding it. Maybe you do it at a lower pressure, or you do some things to protect the plastic before you mold it, or you change the temperature. So if the plastic can be in the part with the molecular weight ear excite, and the molecular weight ear expecting, then it will be stronger. So you don't really have to change the material, but you have to just change how you're making, or how you're molding it. Exactly. Processing of it. Changing a material is not a small thing. If you change the chemistry of a material. So like in a medical device, for example, if I were implanting something in you, and it was made of Teflon, I actually can't just change that in for another material and say I'm subbing like for like, because the other parts of the environment will react differently to different chemistries. So that's probably a bigger change in what you might do first, is try to work on aspects of the microstructure. When going back to your question about concrete, Ayanna, I think your instinct is correct, because concrete has these inherent, it's inherent porosity, it's not waterproof. So I just wanted to clarify it's, it's water resistant, and you can, similar to steel, apply sealants. Well, that's what I was wondering. Like if we're reinforcing everything with steel, and water can get into it, is that a flood? Obviously, it's not, because things are still standing, but I didn't, I didn't think about sealing. But I was thinking about like salt in places with like harsh winters, where like, so I live in Maryland, winters are not harsh, but the salting, from the amount of salt you would think we are like in Canada. There is so much salt dumped on the roads every time there's some light dusting, and I always think like, how is this? It's damaging the road, the bridges, cars, like it is, it is such a harsh chemical, when you put it like in those quantities, frequently, during three months of the winter. It causes a whole slew of problems, and beyond the ones you just described, it's also really bad for the environment. So, yeah, because waterways, surfacing groundwater can only kind of handle a certain amount of saturation of salt, and so it's more of, it's, what do they say? It's, um, dilution, not like the, the solution to pollution is dilution. Yeah, you'll notice that cat and I both live in places where we don't see any snow at all. So I'm kind of like, I kind of remember what you're talking about with salt, but, well, and when I was in Pittsburgh, that's why everyone's cars, you know, the underside of their cars just got deteriorated so much more quickly because of that, all of this, the salt that was getting, you know, built up from the wheels, or thrown up from the wheels into the, undercarriage of the car. Are there special East Coast car coatings that you do on the bottom to protect? That is a good question. We would have to ask my friend Rachel, who is a paint specialist, so for our last question, I would like to ask you, what advice do you have for students who might be interested in engineering? They think they find engineering cool. How could they learn more? What can they do? I think that most people are interested in engineering. I think that most people, I think people tend to think, oh, I don't like math or science, I'm not going to like engineering. I don't think that's true. I think that most people, like knowing the answer to a problem, like all of these different things that people do around mysteries and, you know, problem solving and puzzles, like all of that, you can find in engineering. So, and I do think it is good jobs. Like there's always a need for people to look at the ways things are breaking. There's always a need to understand bridges and making new buildings. And so, I have found it to be a really fun and dynamic field. So, I would tell people to stick with it. And to really follow the aspects and the threads of engineering that are fun to them. But my most important advice is to find really good people to work with that you can learn from. And, and do that as you're looking for mentorship in school, in your jobs, in the people that you have around you. Because that to me is the probably the thing that keeps you the most sane. And, and able to grow in a way that you probably want. How about you, Cap? Hi, I echo what Ayanna says about the people component. And, what I'll add to that is it's, is that you don't have to do it alone. I think they're, at least what I see in some of the more junior members of my team. And others in the early stages of their career is that they think they have a lot of work to do. And, I think they're, at least what I see in some of the more junior members of my team. And others in the early stages of their career is that they think they have to figure it out all by themselves. Now, yes, you want to use your brain and try to devise a solution. But if you can't, you should always ask for help. And that goes for how you want to evolve your career to how you might solve a specific problem. But I think beyond that, I would say, I see myself as somewhat of a generalist. I happen to have focused on civil engineering in my undergrad and then took that add a layer to it in my graduate degree. But I don't consider myself someone who is very experienced in one very small thing. And I think sometimes in the engineering world, it seems like you have to be super specialized in order to be successful. And I would say that that's not, that's one way, but that's not the only way. And so if you are someone who sees things from a more global perspective and can connect the dots, I think a career in engineering can be very applicable to someone like that. Because it isn't just, I'm a civil or I'm mechanical or I'm a landscape person or I'm an electrical engineer. It's knowing how all those things connect together, which I think can take someone to the next level. I mean, I could like literally ask you 50 more questions, but it is four o'clock. And I want to be respectful of our time. Pat and Iana, thank you so much for coming on the show today. Thank you. It was so fun to talk to you. Yes, thank you very much. It was really fun. Thank you for listening to today's episode of Science Fair. Please rate and review the podcast on the podcast player of your choice. Also, please fill out a listener feedback form. You can find a link to the form in the show notes of this podcast or on the Science for Podcast website. Also linked to in the show notes. Finally, we are looking for episode sponsors. 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