Good morning everybody, and it is my pleasure to welcome you all to our panel today on Resiliency for the Home Planet. This is a topic that sort of builds on our visitor, Professor Anna Barroso's talk yesterday when she was talking about vegetation and mountains, rainfall, and ecosystems. We have an exciting panel, by the way, I am Rao Govindaraju. For those of you who do not know me, I am the head of civil engineering, and it is my pleasure to introduce the moderators who will essentially get us started on this. Our first moderator is Professor Aynes Hua, she is a professor in civil engineering and environmental and ecological engineering. Our second moderator is Professor Panayota Karawa, she is the Jack N. K. Hakeemha professor in civil engineering. I think the format is the moderators will get us started, they will tell us a little about the topic. We do want to say that we are live streaming this event, which means people who are watching online are not able to ask questions, so it will be up to us to keep the panelists engaged. So with that, I will hand it over to the moderators. Hello, good morning, and welcome to the panel. I am happy to see everyone here despite our weather outside. So what I would like to do is introduce the panelists, tell you some overarching themes of the panel, and then each panelist is going to speak for three or five minutes or maybe a little bit longer about their own work and how it relates to the theme. So the panelists are Anna P. Barros, Donald Bigger Willett, chair of engineering and department head of civil and environmental engineering, David Yu, assistant professor of civil engineering, Iman Habib, Thomas A. Page professor of civil engineering, co-director of the civil engineering center for applications of UAS for a sustainable environment, CCoS, an associate director of the joint transportation research program, Venkatesh Merwadi, professor of civil engineering with courtesy appointment in agriculture and biological engineering. I want to make a special note and give you some further information about our guest, Dr. Barros, is the Donald Bigger Willett chair of engineering and department head of civil and environmental engineering in the Granger College of Engineering at the University of Illinois at Urbana-Champaign. So she has traveled here to be our guest. Her primary research interests are in hydrology, hydro meteorology and environmental physics with a focus on water cycle processes and regions of complex terrain, remote sensing of the environment and predictability and risk assessment of extreme events. Professor Barros has served in multiple national committees over the years, including the space studies board of the National Research Council, Water Science and Technology Board, Board of Atmospheric Science and Climate and the U.S. National Committee for the International Hydrology Program, IHP of UNESCO. She was a senior fellow at the Energy and Climate Partnership of the Americas from 2011 to 2015 and a founding member of the AAC Committee on Climate Change and Adaptation. Currently, Dr. Barros is the past chair of atmospheric and hydrospheric sciences at AAS and president-elect of the hydrology section of AGU. She was the chief editor of the Journal of Hydro Meteorology for five years and a member of the editorial board of AGU Advances. Professor Barros is a fellow of AGU, AMS, ASC and AAAS and a senior member of IEEE and a member of the National Academy of Engineering. So now I'm going to tell you a little bit about the panel abstract. Why are we here? What are we going to discuss? And here's the abstract. So the backdrop against this panel is that there's a long term economic and societal development that relies on sustainable practices and that can combat the increasing frequency intensity of natural and man-made hazards. Major threats to our well-being on this planet include loss and biodiversity, land degradation and climate change, the cascading effects of disasters and compound extremes cross-social, economic and geographic boundaries. Solutions that leverage the inherent resiliency of the natural environment and reduce risks from hazards at multiple spatial and temporal scales are needed. We seek solutions that promote sustainable and equitable societal recovery. And the panel discussion will shed light on this important topic and discuss innovative solutions to safeguard the planet and build resilience. So with that, I will turn it over to the panelists. Dr. Merwadi is going first. Thank you, Dr. Vain. Good morning, everyone. I'm also happy to see many of you. I'm a faculty member in civil engineering and is my primary area of interest is surface water hydrology. And since coming to Purdue, I have been working on the topic of flooding. So my primary area of interest is flooding. So when we think of flooding, and as Professor Hua mentioned in the abstract, we are experiencing extreme events at increased frequency and they're happening more and more often. And in the past, when we tried to address the issue of flooding as civil engineers, we have been building things. Build dams, build levees. So we call those structural measures. And in order to increase our resiliency, so the goal is, so we know that the floods are not going to go away. They may become more extreme, more frequent. So what do we do? Should we keep building more dams, more levees? And we have learned that they don't always work. We build levees and we think that we are safe because we have this wall that is protecting us. But actually we are less safe because that wall can fail anytime. So we are living under this false sense of security, thinking that we are improving our resiliency. So one of the things that I try to do in my research is how to address this issue in a non-structural way. So there are multiple ways of addressing this issue by not building dams or including structural measures. So there are, as I say, there are many ways to do non-structural measures. So my area of interest is how we can provide better information, accurate information and give more information to public so they are prepared to handle this flood. So towards that goal, what we do is we try to look at multiple pieces of information that is currently available to the public. So one of the pieces of information that many people have these days about flood is our maps from FEMA. So FEMA produced maps and many of us who bought homes, you may have heard from the real estate agent whether you live in the 100-year floodplain or not and if you do, you pay insurance, you buy flood insurance. But the issue with those flood maps are old, they were created using historical data and what we used to call 100-year flood is no longer a 100-year flood. That flood is happening more and more. So those maps are outdated. So what can we do to improve those maps? So that's one of the areas that I work on. The other area that I'm also working on is urban flooding. So there was a mention about urban in the abstract. So how do we improve resiliency in an urban environment? So we know that more and more people are moving in urban areas. You may have heard recent or in the last few years we had Hurricane Harvey in Houston. Houston was flooded, New York was flooded when Hurricane Sandy hit. So we hear about the stories of urban areas getting more and more flooded. So the problem of flooding is very different in rural environment and urban environment. So in rural areas, people can move in urban areas when there is flooding, the whole infrastructure collapses. Everything is connected. When the power station goes out, there is no power. Your trains stop. So there are cascading impacts of these floods when we have extreme events in an urban environment. So one of the things we are also trying to do is how do we simulate those cascading impacts? So if we can predict flood accurately, if we can predict how much water we are going to get at any given location, at any given time, then we can simulate these cascading impacts and give early warning to people who are going to get impacted. So, and then in order to do this, we need a lot of data. We need a lot of computational power and we need, so one of the things we are also trying to do is we don't have data for everything that we want to simulate. So we are also using machine learning and using high performance computing to simulate these environments and simulate the cascading impacts and inform and give better information to public that are going to get impacted from floods. I'll stop there. Thank you. Our next panelist is Dr. Habib. Thank you very much. So good morning, everyone. I'm Aiman Habib and my area of research and discipline is Geometrics and Engineering and basically what we are trying to do is collect data. Exactly, as Venkatesh said, that that's really the most important thing and in order to really ensure the resilience, we have to make sure that you have the right data at the right time, at the right location actually. So this is really where we come in as Geometrics. So I have my cheat sheet notes. So what is really relevant to geospatial data is that right now we are at the stage where we have really unprecedented accessibility to data that we never had at this or we never had the luxury to have this. So just to give you some examples about availability of the data, we talk about global navigation satellite systems. So we have the GPS segment. We have the Russian GLONUS. We have the Chinese Baidu. We have the European Galileo. So right now, we can actually position any point along the surface of the globe at any time with very good reliability. Long, long time at all, I would say, not long time ago, like a few years ago or like 10 years ago, that you have to be very careful when you go out with your GPS to say that I have to have enough constellation of satellites to give me a position. Right now, that's not an issue. With very simple actually smartphone, you have access to lots of satellites actually. Some of our smartphone technology right now are going beyond the GPS to include the GNSS. So they receive signals from non-US positioning satellites. Another advances in our area also which makes the data more accessible is inertial navigation systems. So inertial GPS or GNSS in general is quite good, but you have to work in an open sky. You have to have access to the satellite signals. Now, with inertial navigation systems, these are dead-recording systems. They actually all what they really need to have gravity actually. So by having accessibility to the gravity models, you can really determine positions or changes in your position and the orientation. Nertial navigation systems are becoming quite, quite actually accessible. Now we have IMU units in our smartphones, like just few dollar chips actually. So we are going beyond the stage where we have initial measurement unit, like in the millions and millions of dollars of submarines. Now we have much, much lower cost and good performance units as well. Other data that's becoming quite available right now imaging systems. So we have actually systems that collect visible data, collect thermal data, near infrared, multi-spectral, hyper-spectral data. We have this coming from lots of platforms, just one of these platforms, like high resolution imaging satellites. So right now we have from space, we can collect imagery that give us resolution or level of detail, almost like quarter of a meter on the ground. So the single pixel give us like 25 centimeters. These are available actually for the globe. We have the digital globe. This is high resolution imaging satellites. We have the cube satellites right now are launched by like hundreds and thousands that give us more data that we never had access to it before. We have also a ranging systems or active systems like radar and LiDAR. So as Venkatesh mentioned, we need to have information about the topography. So one of the effective ways of getting the topography is using active sensors like radar, which is a basic radio detection and ranging on LiDAR and LiD detection and ranging. So for example, radar, these are basically can work anytime day or night, whether like cloud independent. So we can get information about the topography even below the surface of the forest environment. LiDAR can do the same thing. We give us very high resolution. We have huge developments in LiDAR systems. But now we are going beyond what we call linear LiDAR to these photon counting LiDAR that basically we can get LiDAR topographic data from satellite from space. And we have the platforms. So we have the, I would say the imaging satellites. We have the airborne system. We have unmanned aerial vehicles. We have the terrestrial vehicles and we have robotics platforms. We have a wide range of data acquisition systems that we never had access to it. So the opportunities we have right now that we have this unprecedented accessibility to the data. We have convergence of disciplines, the fact that I'm here coming from Geospatial in this panel that talks about environmental and basically the resiliency of the environment. So we have really starting to talk to each other. And also we have the ability right now with these machine learning tools that how we can develop the techniques that allow us to take the synergy of this information. However, this is not really everything is easy now. As I said, there are some challenges. So all Geospatial data are not created equal. So basically right now it is very dangerous. Now I can go with my smartphone and I can create a map. This map is not really the same quality that I would create from high end systems. So developing standards and protocols to tell us how good is the data we have. That's very important because making a decision based on a data that you don't really trust. That's really a big problem. And also like the Geospatial data by nature are heterogeneous. You have imagery, that's raster. You have historical data. You have LiDAR data which is point clouds. And then you have also variability and the resolution. You have LiDAR data at 100 points per square meter in some areas you have only one point per square meter. So how you actually integrate data from these heterogeneous sources is quite, quite challenging. And the last part is basically this, like when we talk about data processing techniques. So again, having too much data sometimes it occurs because if you have a machine learning system and you feed all this data to the system, you might run into these overfitting problems that basically it works so nice to this area that when you go to another area it will not work. So have to make sure that which data is necessary for which piece of information that's very important. So this area of active learning and knowing exactly which useful data for your application, that's quite important. Thank you, Dr. Habib. Yeah, hi, I'm David Yu. So I'm an interdisciplinary scientist researching human environment interactions and how that's mediated by built environment design and how such mesh of interactions shape system level resilience. And I researched that using multiple methods ranging from social experiments to systems modeling. So that's kind of research that I do. So I think what we're dealing with is resilience of social hydrological system or couple of human natural system. And I think, so it's a complex system and so to understand resilience and how resilience emerges from such interactions I think we need to not only think about spatial and time scales of physical processes, but also human scale. I call it human or social scale. So people make decisions at different levels of this so-called human scale, like individual levels, households make decisions to protect their homes. At government level, people make decisions during emergencies, right? But even at like medium level, group level, people can organize and kind of group collective actions group level actions such as voluntary rescue operations. Also in countries like India, Bangladesh, when flood is about to happen, community members all come out and they kind of organize actions to, you know, raise levies by sandbagging. So this kind of like a multi-level social scale actions are critical for resilience. And so we need to understand how such human actions at different levels of human scale interact with built environment design and physical processes at different levels of scale. So in one research, so in one research that I'm doing, I'm looking into this so-called phenomenon of levy effect or safe development paradox. So it's a phenomenon where as a society, experience flooding, let's say every 20 years, 30 years and society decides to invest in levies, structural measures. So the society becomes immune or protected from this, you know, more frequent flooding events. But in the process, so it's good. It's good, everything is protected, but then the system becomes highly vulnerable to flood events that occur every 500 years and the results are much more catastrophic. Whereas if you let people, society experience flooding, moderate level flooding, time to time, people may maintain their awareness of their flood risk and they may be better prepared and maintain that kind of social capacity which is critical for resilience. So in one research that I'm doing, I'm currently doing a social experiment with actual human subjects. And I'm creating a scenario, it's abstract but it captures the reality and in the experiment that I'm doing, I'm kind of testing how risk communication affects this social capacity across generations. So in one treatment of this experiment, I allow human subjects to communicate their knowledge of flood risk in a lively conversational manner. And then, so that knowledge is transferred to next group and then to another group through this lively conversation. In another treatment, I test risk communication in which flood knowledge is transferred through historical documents, like in a more text format. So it's not really lively conversation, but it's written down as if it's in a chronicle document. In another treatment, I have this kind of like a bridge physical infrastructure with engraving of highest water level that was reached. So it's like a physical memory. And so I'm trying to test how this different forms of risk communication affects longevity of people's awareness of flood risk and their ability to cooperate and organize group action. So that's kind of research what I do. And so I think it's not about really, so yeah, we need to enter the discipline of research. So we need to do physical experiments. We need to do modeling, but we also need to understand human behavior, decision-making and how that's affected by physical processes. So that's what I'm doing and that's what I'm interested in. Yeah. Thank you, Dr. Yu. Dr. Barros. Well, thank you very much. It's a real pleasure and an honor to be here in this panel. And as I was listening to my colleagues, I thought I should tell two stories that are somehow related to the point raised here. So when I was younger and I started my career, I was very interested in flooding too. And this was at the time that the big flood of 1993 happened in the Mississippi in St. Louis. And this was a dramatic event. It was a continental scale event. And now when I tell students, you don't remember the flood of 1993, they all were born after that. And so nobody remembers that. But at the time it was a major, major event. And of course the statistics were such that you have historical data.  And it actually was not a 500 year event flood. It becomes suddenly a 130 year flood. And this point is important because we're talking about the communication of risk. And how much data do we actually have to estimate risk? And what does that mean?  And that was because of that flood of 1993. I did a huge literature review. And I found publications from the beginning of the 20th century and actually even late 19th century where engineers were publishing in the meteorology literature including monthly weather review. Engineers from Chicago looking at water distribution and water resources in this region. And they were very worried because they dependent on the lake levels. They were dependent on the lake levels for water resources. And there was a big drought and the lake levels were going down and everybody was very worried about this and so on. And they were already very interdisciplinary. So there's actually very impressive literature from that time looking at climate variability, multi-decadal, decadal climate variability. So much so that in the 1930s there are a couple of publications that sort of, you know, they were doing free analysis by hand. This is before digital free transforms and things like that. And you could almost predict the big flood of 1973. That's how far they went into their decomposition and prediction. But the point here being that somehow after the Second World War and the huge development and suburbs growing everywhere and huge industrial development and so on, it became so easy to design for the design event, right? To anticipate the design event. And somehow, you know, that became sort of a fixed value somewhere. And we gained the successive confidence on what does it mean 100 year flood, right? The 100 year flood can happen on average every 100 years, right? But what all that means is that over a thousand years it could happen 10 times, but it could happen twice in the same month, right? It's not about the frequency, right? And so, but because this idea of climate variability was not really included in the risk analysis, the idea of positioning risk, right? Of understanding, are we on the low cycle of 150 years of the water cycle or are we on the high end of that, right? So if we look, for example, at data from denial where they kept the records of the big floods for, you know, that were so essential, right? For the economy of over 5,000 years. If you look at those records you can clearly identify periods of high variability and these cycles of 100 years up to 300 years and so on. And we forgot about that. So independently of climate change, which of course is very, very important and makes everything more challenging. We also have this, you know, the problem of climate variability and how important it is to actually understand where we are in the climate cycle. And when we think about project life, for example, is it 30 years or 50 years, right? And so I noticed that you mentioned that I was a founding member of the Committee for Adaptation to a Changing Climate to the SCE. And so the story that's interesting about this is that in the 90s, as I was looking at all of these issues I got together with a colleague at Penn State. I was at Penn State at the time in the meteorology program and we wrote a paper about climate variability and extremes and the idea of designing for failure, right? So if we know where we are and it's very expensive then we design for things to fail gracefully and recover. So we tried to publish this paper very badly and nobody would take it. And so it was very interesting because eventually we published it in a journal that perhaps many of you have never heard about, which was the Journal of Professional Issues in Civil Engineering, really obscure. But I'm very proud that we actually published it there and that some editor at the time took this on, right? And that's the point that we were trying to make and this was a time when of course ASC magazine, for example, was publishing some articles saying, oh, don't worry about climate change, it's really nothing there and so on. So somehow I got classified as a climate person in the ASC database. And so when Dick White, who used to be a professor at UIC and then later on moved on to be the director of the National Institute of Standards, NIST, he was the founding chair actually of this committee and he fought very hard to start this committee. He finally convinced one of the presidents of ASC to form this committee and then they did a search and they identified everybody who had the word climate associated with their name and that's how I got invited to be part of that. So it's really interesting to see and so it took about 15 or 20 years to be identified that way. And so the reason why I'm telling this story is because I'm hoping there's some lots of young people out there maybe listening or and it's important to sort of stick to the ideas that you believe in, right? Sometimes it's not the right time, but the right time comes. And when the right time comes, you're prepared. And so that's the encouragement I'd like to leave here. And the message is also that this is a time for interdisciplinary research, right? It's not enough to just be good at what small area where we are comfortable, but it's good to be humble and go into other fields and learn from what others know and actually develop our own expertise in those fields and that's how we really can push boundaries. So I'd like to encourage that. So some of us have a history of always doing the wrong thing at our doing the right thing at the wrong time maybe. And that's the same thing with artificial intelligence. You know, we were working on this and the GS was actually also a pioneer in hydrology. In the 90s, we were among the very few doing this and not very well received at all, right? And but hey, 25 years later, this is the hot topic of the day. And so I think there's hope in that, right? That it takes time, but eventually things evolve and we have a contribution to make. So I'll just stop there, but I really wanted to emphasize this point of understanding variability that goes beyond just climate change, right? And these cycles, how important they are. And so the idea of positioning risk, how important that is. I'll stop here. Great, thank you very much. Very interesting insights from all our panelists. Thanks for sharing your research, your stories as well. And now it's time for our audience to ask some preferably provocative questions to our panelists. And I would like to open the floor to see if there is any question from the audience. Very good. I'm Bob Jackal here in the environmental area and civil engineering. And I have a question for Dr. Yu. You interested my thought process here. As you mentioned, the infrastructure, the dams and the flood prevention measures that we engineers make happen. And then you also said, perhaps maybe we shouldn't do that because maybe the people would learn how to live with the floods and wouldn't maybe live so close to the river. So that's my general question to you. Can you expand on that? Thank you. Yeah, yeah, thank you, Professor Jackal. Yeah, so there's this notion of living with floods. I think in Netherlands, they have this kind of a concept that they use to guide how they develop lands and build infrastructure. So I know one case in one kind of case that demonstrate how engineers are trying to reflect that in actual landscape design and infrastructure design. So in Arizona, I did my PhD there, they have this, so it doesn't flood often. You know, it's a desert environment, so it doesn't rain often, but sometimes it does and sometimes it causes flooding, yeah. And so I'm aware of that there's this two lakes in a residential area, and I don't know how exactly they did it, but whenever it rains, it floods, but it's done in a way that this flooded water doesn't get into streets of residential area. So these lakes are in a small neighborhood park, and so whenever there's some heavy rain, it floods this neighborhood park, not the houses, residential area. So people can still, like whenever it floods, they can see that there's flooding, although their homes are not affected, they can see flooding can occur and see, you know, inundation level reaching an ankle of a person. And so they can kind of become aware and maintain that kind of potential risk. So I think that's like, that demo shows like this clever park design that somebody did in Arizona to incorporate that, living with floods philosophy in physical landscape design. Okay, thank you very much. Any other questions from our audience? If I may, I actually wanna add something to this. I was thinking as you were asking the question about the Miami Conservancy District, I personally think this is one of the biggest successes in civil engineering before civil engineering as such existed, I think in this country, but what was done in between 1913 after the big flood of March of 1913 and 1920 in Ohio is really a leading example of how society as a whole actually arrived at an agreement with the legislature. And it was the first act that was actually passed by the state legislature to approve this compact between lawmakers and landowners, right, and local governments such that this idea of having these dams that we're built in several, five of them we're built in five years that most of the time are not working. They only work when there's a flood. And in that case, you let the water go and the farmers agreed and the landowners agreed that their land would be flooded when that happened. And so as a result of this in over more than a hundred years, this has been a very safe river system. But what happened there in terms of social impact involving politicians and private sector and so on was really remarkable. And it's a great example for I think for us to follow even though it's over 100 years old. Thanks, Dr. Barros for sharing your REITs experience from civil engineering. Any questions? I'll ask, well, first, somebody had their hand up. To kind of follow up on that theme, I was really interested in your talk yesterday about the experience in Tennessee with the TVA system and the change in climate there. I don't remember all the details, but you kind of talked about how the farmers switched from moving from crops with cattle and so forth and they adapted. Can you talk more about that? Yes, so I don't know if I know actually enough of the social side of the development, but so the first president of the TVA was actually, oh, am I off? Oh, okay, sorry about that. Yes, so the first president of the TVA was actually the person who engineered the Miami Conservancy District. And so the president of the United States at that time was so impressed. This was the time of the new deal. And so after the country had gone through a depression and so on, and they were inspired by the power of what had been done in Ohio because it involved, they brought in about 15,000 workers at the time and their families. They actually built small towns with churches and schools for these workers. And so for five to seven years, that's what they did. They made sure this was not going to happen again. And one of the dams is equivalent to the size of the Giza pyramid. And that's actually a national monument. But so being very impressed with what had been done in Ohio at the time, just the area of the country in Tennessee was really depressed as well. And so the idea of the TVA came in the tales of that. He actually ended up only being there for one year because he apparently was not very interested in managing money.  But so that was the origin. So it was a project that had more in mind than just building dams, right? And it had huge impact in society at the time. This was also, it coincided with the time when Eleanor Roosevelt was really pushing for the national parks. And so this was the same time that the Great Smokies National Park was actually created. And so part of the land was converted into public land, into parkland and so on. So this all happened at the same time. And so those activities that were happening in the mountains and in the foothills of the mountains basically slowly faded away. People found other types of jobs and they moved on to the lower lands and the other areas of the state. And it became really focused on the hydropower and energy production and so on. So I can't get into a lot of the details. You know, I don't, I should know more, but yes. But it was really a project that completely changed also that region of the country, right? And has had a huge impact. I don't think anybody was anticipating that by creating this vast system of dams, which are basically lakes, right, with free water surfaces, that we were changing the landscape in such a dramatic way that it would change clouds, you know, that would change wind fields and that would have such huge impact in the regional climate. I don't think it's well appreciated. What we know, for example, is, and this was really interesting. So we're running weather prediction models, for example. And when we're comparing predictions of surface temperature over that part of the state, they're always very bad, right? The errors are very large. And the reason is because we're not actually representing the processes that are happening in that lake landscape system properly in these models. And that's an indication that we should do a better job with that. Of course, the data that I was showing from the satellites is basically just the evidence that the change has happened. Thank you very much. Yes, you had a question? Let's see. Anybody in the audience? Well, I have an observation and then a question. Okay. I think, David, you, many of you know holds a joint appointment in political science, which is not the first thing you think about in a joint appointment in civil and political science. But I know of many occasions where I have known the technical solution, how to solve a problem, but I have not convinced the society to be able to accept that solution. So perhaps having David with me would have helped a lot. My question is, you spoke about risk, resiliency, and so on. And we're talking about climate change. If you have any thoughts that you could share on how we assess risk, the climate keeps changing and how do we deal with risk-based design in the future? So this is a question for all panelists. Well, I can get started. So at least in the, in the design community for flooding, we always use these 100-year events and we design for 100-year flow. And historically, we, and the idea is that we use historical information to see what has happened in the last 100, 200,000 years. And we assume that whatever happened historically will happen again in the going future. So we call this the stationarity assumption. So what we are finding is that the stationarity assumption doesn't really hold these days, at least in some places. In some places it does hold, in some places it doesn't hold. So the idea is how we can design for the future by including this non-stationarity. So that's one aspect related to climate. But then there are lots of other things that are changing. We are changing land use. More and more people are living in areas that are prone to flooding. So how do we incorporate all those and estimate risk and quantify that risk and communicate? So those are the areas that we are working on to address that point. Thank you, Vikantes. Any other reflections from the panelist? Yes, actually, I was thinking that I talked so much about the Miami Conservancy District and I didn't mention the name of the big thinker who was in charge of that, who was Arthur Morgan, who eventually became president of Antioch College. But I wanted to actually say how the concept of the 100 year flood came up. So when he was doing his work for the Miami Conservancy District, he was told that he should come up with a design that was going to avoid floods forever, right? Whatever that meant at the time. And so he looked very carefully at sediment records and data from previous floods. And based on that information, he estimated the largest flood that could happen or basically actually the largest precipitation event that could happen on frozen soil, which was the cause of that flood, and used that and called it the 100 year flood. And that's how it started. So there was no standard risk assessment as we understand it, right? And so he came up with the concept of PMP, which is the probable maximum precipitation. And, but it was really something that took off after this. I don't think he was thinking that he was setting the standards for the next 100 years in how we do things. And so I wanted to stress this notion of non-stationarity and climate variability is the basis also for this. And so the importance of thinking, of integrating the notions of decadal and multi-decadal variability in these considerations. The other thing that I want to mention here is that when you live in a big city, we're very fortunate we don't, maybe some of us here, but if you live in Chicago or in Boston or in New York, sometimes in some neighborhoods, you have the 100 year flood every year. It gets to a certain time of the year. We get a certain time of event and everybody on TV is talking about how it's been really bad. Well, probably the storm water system was designed for the 100 year flood when it was designed. But after that, the population has increased by 50%. The paved area has increased by 100%, et cetera, et cetera. And so now the system is really kind of being, has a very narrow drainage system for a very large contributing area. And so this brings us to something that's very important in civil engineering is the idea that we build infrastructure, it's not forever. Infrastructure systems need to be adaptive and grow with us and change, right? And if you build a hospital in a certain location, the implications of that for the entire system in terms of resilience are very different from building, for example, just a neighborhood, right? And so we need to think about the idea of monitoring risk for infrastructure. And so always be adapting. So making adaptation as part of monitoring, I guess, that's what I'm trying to make the point of having this flexibility. It's hard to conceive when we look at concrete and so on, but that's really what we need to do, I think. Thank you very much. You're very insightful, all of you. Any other questions from the audience? Yes, Eijan? Thank you very much for being here for the panelists. A comment and a question. I'm coming from the structural earthquake engineering side. In earthquake engineering, we look at strong motion seismology. If you focus on a parameter such as peak ground acceleration, we have an understanding of its distribution over time based on observations. But when you look at peak ground displacements, which are also important for high rises that are coming up nowadays, we seem to be getting a power load distribution. So the more observations we make, the larger the mean is and the variance becomes pretty much, I mean, there's no end to it. So I wonder if there's something there with the 100-year event, but my question is generally, we inherit the urban environment when we were born to a place, obviously, for our parents. And with the flexibility of having the right idea at the wrong time, including today, if you were to start a new city and you are not allowed to necessarily move away from a river, flood plain or anything like that, because likewise in earthquake engineering, we cannot always move from the hazard seismic hazard. What would you recommend? What are the areas of engineering ideas that perhaps the new generation of engineers, civil engineers or multidisciplinary engineers should work on or think about and research for new development? Existing problems, we will deal with them and I'm sure they will benefit from it. But if you had this kind of blank sheet of a new city, what are the key things that you think we should pay attention to informing? Stop. Wow. I'm sorry. Go ahead. Go ahead. You asked a very tough question. Thanks, Sahih. So assuming that I cannot tell them, don't do anything that is prone to flooding. So there are some examples. So for example in Holland, so they are building or at least designing houses that you can move up and down. So even if it is flooded, you don't have to move out.  So that's one example. As I mentioned earlier, our infrastructure, everything is very interconnected. So if one thing fails, it leads to failure of lots of other things. So one aspect of the design will be, can whatever you design sustain, despite what happens to other components of the system. So we talk about interdisciplinary and interconnected. So how can whatever we design be resilient in this interconnected system? So maybe that's a sort of generic answer. Yeah, that's a good question, tough question. Sure, I mean, I'm always promoting the need for data. So I would say, make sure that you have sufficient data. And again, for these like design areas, that topograph is not really the only thing that you have to really know information about the type of soil, the soil moisture and so forth. So I think collecting data as much data that gives you more than one piece of information about your site, that would be quite useful. So I can, I think you asked a really hard question that I think it has two answers to that. One of them is the engineering answer, which is we would like to instrument everything we build heavily. Sorry, can you move the microphone? Oh, I'm sorry. We would like to instrument everything we build heavily, we would like to have innovative approaches and technologies like floating structures and so on. You've seen a lot of this Lego based sort of structures, where basically infrastructure is changing or even buildings are changing, depending on the conditions, you can easily lift them or move them around and change pieces and so on. How do we do that in a way that it can be done efficiently and affordably and it's still a good investment. But I think there's also a soft side of this that's very important. And it's about regulation, about codes and standards, about zoning codes, for example, about how we deal with risk, right? How do we grow? And the idea that we need to think about our interconnected systems when we approve a new project, for example, how things fit together, how does risk change actually by growing in a certain way? So those considerations are usually not taken, right? So we do cost benefit analysis, but rarely you hear anybody discussing, for example, if we build a huge hospital, for example, which has been a big problem in the areas of hurricanes, right? In a certain location, what does that mean for energy distribution? What does that mean for water distribution? What does that mean for access, right? For and so on. So thinking about the fact that it should not be about norms that are written for 20 years or approved by the city council and work for all problems in the same way. So I think paying attention to that soft side is really important, in addition to all the creativity and so on that we can have with technology. Okay, thank you all. I would like to perhaps move away from this cost benefit analysis. I'm getting so tired of it. Maybe find something else to quantify, quality of life improvement on the human side. I think we need to move on. And I want to ask a question, our panelists, us being in civil engineering, how do we see our students transforming the world? And what do we do today? So they are the leaders, like you mentioned Professor Barros and Professor Govinda Raju, all of you are leaders, right? How do we make our students leaders on this topic? I would like to see your reflection on that. And do we do enough? Oh yeah, yeah. So I think people need students, young students and also policy makers, decision makers, people in policy space. They need to know complexity thinking, complex systems thinking. We live in a society that's, you know, that's everything is interconnected. Failure in one component of the system leads to cascades and affect other things in a really unexpected way. You know, human response to built environment design of physical hydrological events can be surprising. And so we need to, people need to be trained in complexity science, complex adaptive systems thinking, especially decision makers. And also we need to embrace, I think more and more people are talking about this. Embrace failure, like in designing infrastructure, in designing physical, when we design landscape, we need to not be afraid of failure, but you know, but actually embrace failure and use that as an opportunity to foster social capacity and to raise awareness of general population also policy makers. So, you know, I think young students need to kind of have the mentality, you know, we should not only designed to, you know, get rid of all the risks and failure, but rather we should make designs to embrace failure and use that as an opportunity, actively use that as an opportunity to promote learning and awareness. So that's nice, what I'm thinking, yeah. Thank you, David. Yes. Well, I can add since you spoke about students, so we train students at both undergraduate and graduate level. And I think at the graduate level, we have more control on how we can train them to be leaders, so we can train them in certain way. And I think undergraduate is a place where we need to do more. I feel like we don't do enough to train them to address all these complex issues. And since we are all civil engineers and I see many of our colleagues, so I think we need a major overall of our curriculum if we really want to train our students to be prepared to handle these issues in the future. So thank you. Since we have a visitor from a competitive university, I wanted to bring this up. So I want to be mindful of everybody's time. We have two minutes left. Yes, I'll talk about that. I think this is a very important question. And for example, in the case of risk and extreme events, as you've heard this spring, well, it's not yet, well, it started recently, but this winter spring transition has been especially hard in the Midwest, in the southern part of the country without the tornadoes and extreme events and so on. And for example, the question of whether we're designing structures for the right loading, are we accurately representing these types of loads in how we built structures and so on. So we just actually started a new center at UIUC for resilience for wind extremes, and it's a collaboration actually between civil engineering and atmospheric sciences. And we have our faculty and our students were out there in the field, actually in anticipation of the tornadoes, we knew it was going to be bad. So we had teams of students and faculty who traveled down to the south and so on and be right there so we can make these sorts of measurements of what happens in the boundary layer around structures and so on. So it's recognizing that even though we build wonderful things and civil engineers have been extremely successful, a lot of the things we build are standing and they will be standing for another hundred years and more, but the fact of the matter is that a lot of what we do still needs a lot of research and we could improve significantly what we do. And so it's investing, I think in research, investing in things that maybe are not yet the hot topic of the day, but that will be the hot topic of the day in 10 years. So we try to think ahead and plan for that. And I think there's a lot of opportunity for those sorts of initiatives. Great, thank you everybody. Let's... Thank you. Thank you. We really appreciate your visit, your time and thank you all the panelists. You did a great job sharing your worlds and your passion about civil engineering. So thanks everybody for being here and have a nice rainy day outside there. Bye.


Hello and welcome to This Week in the City. Highlights brought to you from the Public Relations, Media and Marketing Department with the City of Columbia. I'm your host, Alicia Utsi. In our first item for this week, we have a reminder regarding the upcoming municipal election. The City of Columbia's municipal election will be held on Tuesday, November 7. No excuse early voting began on Monday, October 23 and ends on this coming Friday November 3, 2023. Early voting is being held at 2011 Hampton Street and 2020 Hampton Street, Monday through Friday from 8.38am until 5pm. On Monday, October 30, the Planning Commission will meet at 4pm at City Hall in Council Chambers. The meeting will be a hybrid, which means that you can actually attend in person or you may view the meeting on live stream via YouTube and the City's website at ColumbiaSC.gov, which is where you can also find agenda items. Happy Halloween to all and the City is ready with various Halloween events at different parks throughout the City. As you will see on our screen, Halloween events will be held this week on different dates and at different locations. For specific information regarding Halloween events at a local park in your community, contact Parks and Recreation by calling 545-3100 or visit our website at ColumbiaSC.gov and look for the web slider on our homepage for all Halloween events this year. And just as a reminder, on Tuesday, October 31, the pet adoption special for the month of October will be ending. You may adopt the pet for only $13 until October 31 by contacting the Columbia Animal Shelter. On November 1st, join us for an announcement of a new initiative called Blue Zones, which is a partnership between the City of Columbia and Prisma Health. On Wednesday, November 1st, the City of Columbia and Prisma Health introduce the Blue Zones initiative. This will be held at 5pm at the Columbia Metropolitan Convention Center located at 1101 Lincoln Street. For additional details, visit our website at ColumbiaSC.gov and on Friday, get ready for Food Truck Friday, which will be held from 11am until 3pm in the REI parking lot located at the corner of Bull and Colonial. Come up for some of the best food from local food vendors in Columbia. And that wraps up this week in the City. Please contact Public Relations, Media and Marketing for any questions you may have about any of the information we have shared. Please call<PHONE_NUMBER>, email us at PIO at ColumbiaSC.gov or you can follow us on our social media platforms and visit our website for the latest updates from the City of Columbia. And remember, we are Columbia.


It's a difficult concept leadership and so to try and make it as concrete as possible at least to get started Let me let me provide you with a with an expression or a metaphor that I think begins to capture the subtleties and the difficulties involved in the notion of leadership It's the expression of a textu to tango and tango itself as an expression of what or a metaphor of what? Leadership is about at least when it happens well And so imagine you have a dancing space, which is quite crowded and have quite a few couples which are dancing tango together And you as a couple are in the midst of that dancing space and you have to find your way through the space You want to dance together? There are other couples there so in a sense It's like other couples which are present opportunities also threats You have to find your way some places will open up to dance other ones will close down I think that that is a metaphor what it is to be a university that is in the middle of society as it were That has other universities with which it's competing collaborating. There are social actors There's a broader domain within which it has to excel as an organization now What what this means in terms of what it takes to tango? Became clear for me because I actually happen to love to dance tango. I'm not a good dancer. I'm a lousy Dancer and this is not to to be an sort of active self-modesty in the in the framework of this of this meeting I'm not a good dancer. My partner is and Because she's a good dancer. She can compensate for a lot of my my faults And so my tango teacher wasn't particularly happy with me So what he invited me to do was to dance with someone else who didn't Hadn't danced with me and so who wouldn't anticipate turned out to be a dancer who was much much much better than what I was and She was actually several levels above me and So the tango music began I walked up to her I courageously asked her to dance She stood up and then so we got ready and I began to move and nothing happened Niente nothing It was like she was a sack of potatoes and I don't know it was whether she didn't like me I don't know if whether she wasn't in the mood But I had to actually push her into movement and then dancing afterwards was a torture because it was like like Like trying to swim in molasses And when the dancing ended I you know, I was just I was just thought my gosh if this is what tango is about You know, I can't I can't deal with this and In a certain sense, I this was a moment of reflection for me and I thought what went wrong here And what what were my preconceptions about what tango is about in what way were those preconceptions wrong? I think that what this showed me is that in a certain sense if you compare that image of my you know That failed tango to the to the image of the tango couple that is you know effortlessly dancing through the space You would think that that second example of the couple who which is effortlessly dancing through the space and Navigating its position within a complex field that what you have is a guy there who is the leader and someone who follows and That that precisely is because there's someone who follows and someone who leads that it's successful But in a certain sense, I think that that's not really what was what's at stake in leadership I think that the difference between the two situations is that in a certain sense unless who follows also leads and leads by Anticipating and already being prepared to receive and to move in a certain direction Nothing will happen, which is what happened with this partner of mine who acted like a sack of potatoes And so what happens is when you have a good tango couple which are dancing beautifully Is that there's someone who leads but in the very process of leading you're also following and that who follows? also leads and So in a certain sense, yes, there's a leader and there are followers But in a certain sense at each level of the organization Who follows will also have to lead in the sense of anticipating and want to cooperate to take that organization a step further Now this is of course a metaphor Tango and so let me try and generalize it a bit to make it a bit more Concrete in terms of what it means for a larger organization like Tilburg University Let me do so by drawing a distinction which is common or prevalent in common in collective action theory Which is a domain of philosophy. I happen to be a philosopher. It's a distinction between we each and we together But that means is this the the lady and I That just couldn't get our acts together. That was we each Two individuals. They're standing side-by-side, but not really doing anything together and The example of that couple that dances beautifully weaving in and out of the spaces of the opportunities and threats Which are available on that dancing space is we together? now it seems to me that what leadership is about is trying to articulate in a Dialogue with the participants of that we together what it is that we're doing together What is it that we are about as a university in an ever-changing context which brings threats and Opportunities think of the Tango example. You're you are weaving your way through a more or less crowded space Opening up possibilities closing down other possibilities So in a dialogue with those who follow but to the extent that it's a dialogue There's also a leading which is taking place there try to articulate what we are about as an organization And what we are about as an excellent organization And that also therefore means that you have to accept the fact that it and there's a difference with That is not merely about being able to come together and enjoy Tango, it's also the fact that in an organization there will be conflict There will be conflicted in conflicting positions about what it is that we are as a collective and what we ought to be as a collective But I think that what leadership is about is accepting that What we're trying to do is articulate what we are together and who we want to be together But also accepting that we are we each that is to say that there are different perspectives on what it is that joins us together and Wanting to have that moment of we each be part of the articulation of what we are Together it seems to me that this is at the core what we are trying to do in this connected leadership Project and initiative and it seems to me that this is something that doesn't happen only at the level of the rector It doesn't only happen at the level of the board of directors This is something that happens all the way to the collect through through this organization in different ways certainly But throughout the organization as a whole


Good morning, we welcome you to this session, where we will discuss the energy transfer in continuation of our earlier discussion and the concept of impulse and reaction machines and the definitions of efficiencies of hydraulic or fluid machines. So, let us start from the discussion on energy transfer again, which we have already recognized in the earlier class that the head which is being transferred by the fluid to the machine can be written in three distinct components, which we have already seen. One is the change in the dynamic head that is due to the change in the absolute velocity of the fluid. Another component is the change due to the motion of the rotor from one radial location to other radial location. This is usually called as centrifugal head due to the change in the centrifugal head for which the static head or the pressure head of the fluid is changed and another is due to the change of the relative velocity of the fluid with respect to the rotor from its outlet to inlet, which is the change also in the static head or the pressure head of the fluid. Now, here with this concept we can identify different types of fluid machines. One type of fluid machines is axial flow machines, where the main direction of the fluid flow is in the along the axis of the rotation of the rotor. Just you see here, just if this be the rotor, let us write here this be the rotor and if this is the axis of rotation, if we consider two vanes mounted on the rotor disk, then the fluid inlet velocity if it is like this and the fluid discharges this direction, then we see that the inlet and outlet conditions of the fluid are such that the main flow direction is along the axial direction of the fluid. The most important thing is that the inlet and outlet of the fluid does not vary in their radial location from the axis of rotation. That means you see that throughout this radius there is a change in the radius from this point to this point, but throughout there is an inflow and here also throughout there is an outflow. That means we can take a representative point or representative plane of inflow at some radial location, for example which may be the mean of this height. Similarly, at the exit we can take a representative point or representative section, which is at some mean height from the root to the tip of the plate. Therefore, the inflow and outflow of the fluid does not vary in their radial location from the axis of rotation. So, what happens in this case with respect to this equation we can simply tell that for axial flow machines u 1 is equal to u 2. That means change of static head due to the change in the rotor velocity, because of a change in the radial location for inlet to outlet does not take place. That means there is no centrifugal head transfer between the fluid and the rotor in axial flow machines. Now, this component if we come whether there will be a change in the static head due to the change in the relative velocity of fluid from with respect to the rotor between outlet and inlet that depends upon the passage here you see that depends upon the area of the passage as the fluid flows through this passage. For example, this two vanes whether the area is converging or diverging in the direction of flow or not. So, that depends upon the setting of the blades if the blades are set and their curvatures are such that if the passage that is the passage that means the area normal to the flow is converging one then what will happen the relative velocity in the outlet will be more compared to that at the inlet for which the pressure at the outlet will be less compared to that at the inlet. That means the fluid will release this pressure that means fluid will release this pressure energy which will be contributed as a positive term to the energy or head transfer to the rotor.  Well now we come to another class of machines according to their direction of flow radial flow machines now radial flow machines are machines where the main direction of the flow is in the radial direction and here what happens the radial location of the fluid that inlet and outlet changes there may be two possibilities one is the radial inward flow another is the radial outward flow. In radial inward flow the fluid flows inward radially inward that means the inlet of the fluid is at a higher radial location from the axis of rotation of the rotor let I write this as rotor and it is discharged at a radial location which is lower than that at the inlet that means the main direction of flow is in radially inwards just the opposite one is the radial outward flow where the main direction of flow is radially outwards that means the inlet position is at a radial location which is lower than that at the outlet location from the rotor axis.  So, if you see here you see that in this case we get a positive value of this quantity which means the centrifugal heat is being released by the fluid which means the pressure is being released by the fluid pressure here is lower pressure here is higher because the centrifugal head which we discussed earlier is higher here and it is lower here. So, while the fluid flows radially inward it releases its pressure energy or the centrifugal head and that is being transferred to the rotor. So, in case of turbine for these reasons the radial flow in case of radial flow turbines the flow is radially inward. Similarly, in case of radial outward flow we can write that u 1 is less than u 2 because here 1 is here at this section and the outlet section is at a higher radial location.  So, this happens in case of pumps or compressors. So, therefore, in pumps of compressors to utilize the centrifugal head in the useful energy we make the designs such that the fluid flows radially outward. This pumps and compressors are radially outward flow machines for turbines the radially inward flow machines provided they are radial flow machines. Nevertheless there are axial flow machines pumps and compressors also after this I now come to the definition of impulse and reaction machines. Now, if we look to this equation again we see that there is a distinct difference between the first term and other two terms which we have discussed the first term is known at the change in the dynamic head. That means due to the change due to its absolute velocity and these two terms represent the change in the static heads. That means change in the pressure head one is due to the change in the radial position and another is due to the change in the pressure. Now, the proportions of the change in the head due to this dynamic one and the static one is a very important parameter in the design of fluid machines and this relative proportion between the changes in dynamic and static head is characterized by a very important parameter known as degree of reaction. Let us denoted by a symbol r degree of reaction r. So, degree of reaction is defined as change in static head change in static head change in static head in the rotor in the rotor divided by change in total head which means what fraction of the total head is being changed by the static head. So, if we recall the expression we can write the change in static head is one by two g times u one square minus u two square this changes I write with the positive sign as that delivered by the fluid with the usual convention and then v r two square minus v r one square and divided by the h. That means what fraction of h r represents is responsible for the change in the static head well with these definitions we can define or we can divide the fluid machines into very two important categories one is known as impulse machines impulse machines another is reaction machines. Now, impulse machines are those machines where the degree of reaction r is 0 which means there is no change in the static head. That means the change in the total head that means the total head transferred between the fluid and the rotor whether it is transferred by the fluid or the rotor to the rotor or by the rotor to the fluid is only by the change in the dynamic there is no change in the static head. So, very first consequences first consequence of this impulse machine where r is 0 is that if you look back again in this equations if there is no change in the static head. So, if we consider first the two terms would be independently 0 then u 1 has to be u 2 that means the impulse machine has to be has to be an axial one has to be an axial one again there should not be any change in the relative velocity of the fluid which means that an impulse machine the flow passage should be uniform in cross section to the direction of the flow. So, that the flow velocity that means the relative velocity of the fluid with respect to the machine should not change for which the pressure of the fluid will remain constant and this constant in pressure of the fluid in the rotor makes a simplification for the design of an impulse machine is that impulse the rotor of the impulse machine may be made open it may not need any casing. For example, it may be open to atmospheric pressure. So, that there may be a change in the absolute velocity, but throughout the flow the pressure will be constant at atmospheric pressure and one of the impulse hydraulic machines rotor is made like that. So, therefore, this is a simple design for impulse machine. So, we can write therefore, for impulse machine the pressure will be constant for impulse machine we write for impulse machine for impulse machine the outcome is axial flow that means u 1 is equal to u 2 pressure in course of flow through rotor rotor is constant which means v r 2 is equal to v r 1. So, therefore, r is 0 in this case since the dynamic change in the static head is 0, but you can argue one thing theoretically I must tell in many books you will not find this statement that you can tell sir why independently it will be 0 some of this made me may be made 0 for which an axial flow machine is not a immediate outcome of an impulse machine impulse machine may be a reaction type where the two effects may be opposing to each other that means it may be a radial inward flow. So, that the head is released by the fluid and at the same time passage may be made such diverging passage. So, head may be gained by the fluid. So, static head released by the fluid due to the change in the centrifugal head may be balanced by the static head gained by the fluid due to the change in the pressure two opposing effect, but that design is very difficult. So, usually it is not done in practice though theoretically one may conceive that that the two components may give an opposing effect to cancel each other, but according to that the design of a radial flow impulse machine is difficult. So, you may note here a very important thing that is why the impulse machine is always an axial flow machine. So, next we come to the reaction machine. So, it is very simple that as impulse machine is defined where the degree of reaction is zero that means the static head change in the rotor is zero reaction machines are those machines where along with the change in the dynamic head static head of the fluid also changes. That means there is a provision for the change in the static either by virtue of the change in the radial location of the fluid in course of its flow from inlet to outlet along with the change in the pressure because of a change in the relative velocity due to a varying area passage of the flow while it flow which takes place through the vane passages or blade passages. So, therefore according to this definition we can write reaction machines react this r is greater than zero or rather we can write more explicitly zero less than r less than one because the maximum value of r will be always less than one. So, therefore this is the definition or difference between impulse and reaction machines. Now, this concept of impulse and reaction machines before coming to the description of actual machines can be well understood by this very interesting, but simple examples of two popular fluid systems. You see one here is a simple paddle as you know the simple paddle these are certain straight blades which are being rotated by a flow of water jet which is coming from a fixed nozzle. You see the nozzle is fixed where high pressure water enters into the nozzle and it flows through a convergent duct which converts the high pressure low velocity fluid to a low pressure and high velocity fluid and it comes out with a high velocity fluid jet. So, water is used. So, water jet which makes this wheel to move this gives a very good example of an impulse machine. So, this nozzle and this wheel can be thought of as a fluid machine here I like to tell you one thing a fluid machine as a whole consist two parts one is the fixed part known as stator another is the moving part known as rotor. So, as far as the definition of the degree of reaction is that it is the proportion of the energy transfer that takes place rotor because the energy transfer takes place only in the rotor energy transfer means the transfer of stored energy to mechanical energy or mechanical energy to stored energy. So, therefore, here we see if this two constitutes a fluid machines. So, in the rotor the fluid pressure is throughout constant that means it is atmospheric pressure. So, the transfer of fluid energy or head to this rotor of the moving part of the fluid machines which is the paddle wheel is because only of the change in its absolute velocity and this is known as the impulse action by which the water jet is capable of rotating the paddle wheel. This is an example of impulse machine here you notice one thing that the pressure initially in the machine the input is the pressure energy of the water, but this pressure is being totally exploited in terms of the kinetic head or the velocity of the water in the fixed part of the fluid machines. That means nozzle when it strikes the rotor rotor is open. So, its pressure remains same and there is no change in this static head. Now, next you see another very interesting example well the interesting example of a reaction machine. If you consider a lawn sprinkler what is the lawn sprinkler probably you know that it has got two nozzles mounted on two arms of a rotating device. That means if you make free and if the water at high pressure enters into this system like this and it flows through these two arms is the two pipes and comes out from the two nozzles in the form of high velocity jet. Then due to the change in the angular momentum that means if you can find out the momentum of the fluid here it is take the moment about this axis and of course of this makes gives a turning moment for which it rotates. So, if you make it free it will rotate that means the energy is being transferred from the fluid to this lawn sprinkler. So, this way lawn sprinkler can be thought of a fluid machine where you utilize the high pressure energy of the fluid at the extreme inlet to develop the work output from the lawn sprinkler which is capable of rotating if you keep it free. Now in this case you see that this nozzles where the fluid pressure is changed from high pressure to low pressure it also moves. That means in this case nozzle was the stationary part, but here nozzle is the part of the rotor. So, therefore, you see while the fluid flows through the rotor both the absolute velocity of the fluid changes there is an increase in the absolute velocity and at the same time the relative velocity is changed. How we can realize it because there is a change in the pressure because pressure here is high pressure here is high pressure here is high only in the nozzle part which is also moving pressure is changed. That means in the rotor both the absolute velocity and the pressure of the fluid is changed. That means we get both the change in the dynamic and the static at in the rotor where in this case there is only a change in the dynamic. So, lawn sprinkler is a very good example of a fluid machine a reaction fluid machine the very good example of a reaction fluid machine while a paddle fluid is a very good, but simple example of a impulse fluid machine. Now next I come to the definition of efficiencies of fluid machines efficiencies efficiencies of fluid machines eta efficiency as you know the efficiency of any system is defined as in the output to input. So, similarly for a fluid machine the efficiency is defined in a generalized sense at the useful energy delivered useful energy useful energy delivered that is the output energy divided by the energy supplied. So, this is the basic definition of efficiency of a fluid machine that is the useful energy delivered divided by energy supplied. Now there are two types of efficiencies that are defined in fluid machines one is hydraulic efficiency afterwards we will refer to these two types of efficiencies. So, you must know the definition at this juncture that one is hydraulic efficiency eta h symbolize that another is overall efficiency overall efficiency eta o. Now hydraulic efficiency concerns about the energy transfer between the fluid and the rotor and overall efficiency concerns about the energy transfer between the fluid and the shaft coupling. The difference between these two is the energy that is being absorbed by the mechanical system like bearings couplings that means it is the energy which is lost in the transmission in the mechanical transmission. Well we can understand this better if we see that if we can think in this way that let us consider turbine in case of turbines in case of turbines. Let us see that let this is the turbine let this is the turbine you know in case of turbine what is the input energy is the stored energy of the fluid as we recognized earlier that is the stored energy of the fluid yes. Now this stored energy of the fluid here we consider the turbine rotor rather you write it sorry is the rotor r rotor simply rotor we are doing it for turbines. So, it is the rotor rotor of the turbine rotor of the turbine stator plus rotor you can write s plus r that means stator plus rotor the total machine. So, it comes to the stator and rotor then what happens just from the rotor we get useful or we get the mechanical energy out that means the rotor delivers the mechanical energy to whom it is delivered to the shaft to a mechanical to a mechanical transmission system. Yes that includes everything mechanical transmission it goes to the shaft it goes to the shaft and the shaft gives are the work w s that is the shaft work known as shaft work or this is the work delivered at the shaft coupling that means the work delivered coupling you can very well understand it that rotor due to its motion when the fluid flows through the rotor the energy is transferred to the rotor and immediately rotor delivers some work. So, hydraulic efficiency concerns with that transfer then that work is being transmitted through mechanical transmission system to the shaft where we get finally, from the shaft as the shaft work what delivered at the coupling at shaft. So, therefore hydraulic efficiency according to its definition is w by e s that means it is dealing with this conversion from the stored mechanical stored energy of the fluid to the mechanical energy or output given by the rotor whereas, the overall efficiency the input is same e s, but the output is the final shaft work that means which takes care of the losses in the mechanical transmission system the loss is due to bearing glands shaft couplings all this thing. So, if you see that that from the two what is eta o by eta h eta o by eta h will be w s by w that means this is the ratio between these two which can be defined as eta m that is mechanical efficiency mechanical is very simple to mechanical engineers that overall efficiency for a work producing device is the hydraulic efficiency into mechanical efficiency which takes care of the hydraulic losses as it flows through the turbine for which there is a discrepancy between these two quantities and the mechanical loss which takes care of the discrepancy between these two things because of the mechanical friction similar is the case for pumps and compressor if you see that pumps and compressors pumps and compressors the concept is same here what happens the mechanical energy e m is being first put as the input energy through at shaft coupling at shaft coupling that means the extreme output terminal for the turbines is the extreme input terminal for the pumps and compressor that means here also we can consider the mechanical transmission mechanical transmission well after which this mechanical energy goes to the stator plus rotor of the compressor that means as a whole the fluid machine the compressors are pumped and final output point and if at the final output point we get the stored energy of the fluid that means this is the useful energy delivered useful okay e sorry i am sorry correct correct it is e s i am sorry e s useful energy correct useful energy delivered that means in case of pumps or compressors as we know the useful energy delivered is the stored energy of the fluid so in this case we see that this mechanical energy is being changed when it comes to stator and rotor due to the mechanical losses due to friction in this mechanical transmission system let this energy is e so therefore in this case what is hydraulic efficiency hydraulic efficiency concerns with the energy transfer between the fluid and the rotor so therefore the hydraulic efficiency will be e s that is the stored fluid energy that is the useful energy delivered in this circumstances divided by the energy which is being received by the rotor similarly the overall efficiency which deals with the energy transfer between the fluid and the shaft coupling that means the output is the same in both the cases the useful energy delivered stored energy in the fluid but now input will be the extreme at the extreme terminal point where the input comes initially that is a shaft coupling e m that is the mechanical so in a similar fashion we can write that eta o by eta h is e by e m it remains the same that means it is this energy which is being received by the rotor divided by the energy which is being fed at the shaft coupling which is nothing but the mechanical efficiency and takes care of the losses in the mechanical system mechanical transmission system so we have now recognized the different efficiencies in a fluid machine is the hydraulic efficiency which concerns the energy transfer between the fluid and the shaft coupling that difference between which is taken care of by the mechanical friction or the friction in the mechanical system well so we will I will stop here next class I will discuss the principle of similarity now I request you so if you can you please read and the principle of similarity as well as the principle of similarity so if you can you please read and the principle of similarity as already you have read earlier make a recapitulation of that so I will start from a basic recapitulation recapitulation of principle of similarity and then I will discuss the application of principle of similarity in fluid machines which is very important in designing any equipment for our engineering applications the principle of similarity ok well thank you


A little daunting this morning. I've got two mics on. I've got a vega mic and the, I guess they're afraid you wouldn't be able to hear me. So Gardner, thank you for that kind introduction and Dr. Rom, I also need to add my appreciation because I know how much work it is to bring together this many people and and I am not just honored, but quite happy to be here for the third conference on women peace and security. The theme for this year's conference critical pathways stimulating and safeguarding components of women peace and security You've you've done great work. You've got wonderful panels lined up covering a range of issues related to this topic But how does one actually build a critical pathway and what does it take? I'll start with a story about a man who was new to his neighborhood He wanted to get himself acquainted with his surroundings So he decided to walk down the street and as he was walking he came across another man carefully building a foundation He watched the man expertly lay the mortar smooth it with a spade and place his brick Wow, he said that's nice work. Thank you says the man I'm a bricklayer and my work has to be absolutely perfect So the man keeps walking around the street thinking the whole time about how impressive the bricklayer was Until he gets to the end of the road and sees the corner of a building being built Though unfinished it is one of the most beautiful structures He has ever seen and he is astonished that it was even better than the earlier work Wow, he says to the man next to the corner. That's amazing work. Thank you says the second bricklayer It's important work. I'm building a hospital Purpose Purpose matters to us and purpose is the reason we serve and purpose transforms bricks into hospitals When we consider critical pathways for woman peace and security, we have to think about the end goal What is our purpose and what will our bricks become on December 10th? 1948 the United Nations adopted the Universal Declaration of Human Rights This was one of the most important bricks in the foundation of global women's rights The first article states that all human beings are born free and Equal in dignity and rights and with this document the United Nations defined its purpose to safeguard The universal rights of all human beings Yet despite this charter human rights eludes millions of women across history and around the world Women have been died have been denied rights voting property and freedom of expression more bricks are needed The United Nations placed an important brick in 2000 when the Security Council adopted resolution 1325 After numerous conferences and increasing conflict around the globe this resolution finally addressed the dichotomies women faced in the 20th century increasingly the target of violence and increasingly denied participation in efforts to end war So vice being the means to end that violence and secure the peace Resolution 1325 changed the way the international community approached issues regarding to peace and security For the first time we talked about conflict not as something happening to women But as something that requires the active involvement of women from conflict to resolution In the 15 years since the resolutions implementation the UN documented reasons why it's vital to involve women in peacekeeping and security roles These roles empower women in the host community and they help make the peacekeeping force Approachable to women women are able to interview survivors of gender-based violence They mentor female cadets at police and military academies and they are able to interact with women in societies Where women are prohibited from speaking to men Here in the United States. We placed our own brick four years ago with the implementation of a national action plan And this whole of government approach to fully implement resolution 3025 across the country We recognize that when women become equal partners in all aspects of peace building and conflict Prevention many of the challenges we face can be addressed The effort to fully execute the national action plan is the purview of all the branches of our government and In order to ensure women are equal partners in all aspects of peace and security The military must be a part of the interdependent inter-agency efforts as Military service members our work can have great influence on international diplomacy Policing and often literally help others build homes schools and bridges Brick by brick sailors Marines soldiers and airmen are all doing the hard work enunciated in our national action plan Yet we still need more bricks in order to ensure the plan is a strong foundation for change Tragically since World War two more than 90% of the casualties and conflict have been civilians and more than 70% Of those are women and children yet around the world women have limited roles in defense peacekeeping and humanitarian assistance Unfortunately, the only role commonly accepted for women is that of being a casualty If our purpose is to build a society where all women enjoy their inherent universal human rights Women must be involved across the range of peace and security issues To accomplish this women must build with bricks from three crucial areas defense diplomacy and development a Future edifice of strength can be envisioned by the stories of three proud women who have done incredible work The first comes from Afghanistan in defense Latifah Nabizata and her sister did not grow up playing with dolls. They grew up playing pilot There was only one problem Her country of Afghanistan had never had a female pilot and despite their initial shock the girls parents were supportive Which was vital for their success at the time when women in Afghanistan didn't even work outside the home in 1988 Latifah and her sister Laluma were accepted to the Afghan Air Force Academy at that time No women had ever graduated from the institution and in addition to that burden They had to endure men throwing stones at them in school and frequent intimidation, but they did not run They took these stones and paved their own way. They graduated in 1991 Realizing their dream and becoming helicopter pilots Latifah's favorite flights involved those where she would be among women Sometimes she would land in Afghan villages and be surrounded by women Latifah recounts that these village women showed an incredible interest in me and my success I hope I encourage them to follow their own dreams She even continued flying after the birth of her daughter Malayla Within months Colonel Nabizata was back in the helicopter There were no childcare options for her so she brought her daughter along She explained Malayla has grown up in a helicopter and sometimes I think she's not my daughter She's the helicopter's daughter Now Malayla goes to school during the day But Latifah has asked the military to establish a kindergarten to assist other women in the military the children Time in the helicopter seems have made an impression on her daughter Malayla She says she wants to be a pilot like her mother And Colonel Nabizata serves as an outstanding example of the tenacity and determination with which women have pursued a Role in the defense of their nation in a country with very few examples and of women and positions of strength The courage of Colonel Nabizata gives women a reason to dream to strive and to never give up She has proudly taken her brick and placed it in the future for a more secure Afghanistan And diplomatic inspiration comes from Great Britain Catherine Ashton worked for most of her life on issues of nuclear disarmament Education and training and families She's had one of the most remarkable diplomatic careers of the 21st century in 2009 Lady Ashton was appointed the European Union's first high representative for foreign affairs and security policy She was the source of ridicule by some who said this woman was out of her league Yet she proved her doubters wrong after her first year of work in 2013 She helped Serbia and Kosovo reach a deal normalizing relations after decades of conflict in July 2013 She visited Egypt in the midst of the Arab Spring one of the first of the Western diplomats to do so and in November 2013 She chaired negotiations with Iran that led to the Geneva interim agreement on the Iranian nuclear program in the span of just seven Months she taken on some of the most difficult issues in the world and produced unbelievable results Judge me on what I do, and I think you will be pleased she says Women and diplomatic leadership roles provide essential perspective to some of the most deep-seated conflicts around the world Brick by brick Lady Ashton and women like her build the structure of a more peaceful world in Development is the story of a girl who grew up in a refugee camp in Uganda She always dreamed of going home in 1994 genocide ripped Rwanda apart at the seams Alosia and Yamba and many women like her fought to end the genocide and raise a country out of corruption poverty and disease in a country that afforded very few rights to women and Yamba did not hesitate to risk her life to save her people in 1994 at the age of 30 She was appointed Rwanda's minister for gender and family promotion one of the first females in government after the war She was also created a national women's movement which lobbied the new Rwandan government for greater female representation And she grew to be an influential force in national affairs Thanks to her efforts progress has been remarkable Two decades after genocide females comprised 64% of parliament making Rwanda the only country in the world with a majority female representation Half of the country's 14 Supreme Court justices are women Every indicator from malaria contraction rates to sanitation to poverty has dramatically improved Rwanda leads many of the sub-saharan African nations in achieving the Millennium Development Goals set by the United Nations In Yamba's life's work was to ask how do we tap into the population through education through economic empowerment and political Opportunities for the women then they will serve and contribute Before her death in illness in 2012 She placed her brick for the future of Rwanda and inspired thousands of Rwandans to do the same Latifah Navazada Baroness Ashton and Alocia Yamba are sources of inspiration for bricklayers They show us that anything is possible with purpose and with action We must remember our purpose as we go through our own lives We must remember that we can lay bricks that put an end to destructive cycles of violence We can lay bricks that support leadership opportunities for women. We can lay bricks that create lasting security The future must include a citizen walking around a secure neighborhood Who comments to the bricklayer on the wonderfulness of the edifice and in that future that bricklayer? She must respond back. It is important work. I and building a nation Thank you