quality and housing the poor it becomes quite easy for me to introduce the next Peter which is Senate because I think if there's some one from the last 30 40 years certainly in the English language to start off with because that's the language in which he writes has been a keen observer of the issues of social integration and the relationship between physical form and social integration and therefore equally attentive to the issues of the creation of social exclusion by the structure Richard has and is a professor at the London School of Economics but also teaches at New York University with Professor of Sociology is the chairman of the city's program which is one of the elements obviously which organizes this event together with the Hermarten Society and is also teaching at the IT so it's my pleasure to ask him to reflect on the issues of urban inequality which will then lead on to the next session on housing. Thank you it's a great pleasure to come to Mumbai and turning out to be a very very productive session for your visitors from abroad and hopefully in the informal and informal sessions that we have over remaining to the next day and a half we will be able to articulate a set of common interests and problems that we share. I come to you with one of those problems which was one of the reasons for creating the urban age project itself and that was that problem is that urban design went into a kind of creative decline in the 20th century. The art of making cities became an art that became increasingly crude and unable to respond to the realities of social life in cities as they changed particularly in the 20th century. And part of the point of the urban age is for professionals themselves to recover some of the art of making cities. Something that we have to do by a lot of thought often whereas in the earlier ages this seemed like a kind of almost instinctive practice about making environments. I want to speak to you today about one of the challenges to recovering the art of urban design. And it has to do with dealing with the problem of changes in global capitalism. The kind of visual forms are appropriate to this profound change in the political economy of today's modern world. And in particular what kinds of visual or physical forms are appropriate to dealing with one of probably the greatest of the deficits of this global system which is the increase in inequality that it generates. Excuse me, I haven't spoke about the reformulation of inequality that it's generated in the last two generations. How could a designer go about addressing the phenomenon of inequality? And I just want to share with you in the next 20 minutes some thoughts about this. This is a huge problem and I thought about it in a rather homely way. And it has to do with my thoughts on this recur to the Hippocratic oath that all doctors take. And the Hippocratic oath, as you know, actually not devised by Hippocrates but no matter. But the Hippocratic oath is do no harm. And I think the issue for us has a parallel in the world of urban design. How can we do no harm in design? That is, in this context, how can we not make inequality worse by the things that... The Hippocratic oath is not a negative formulation. Do no harm inspires the doctor to look closely at the conditions of well-being. What Hippocrates did say is that you're likely to treat a patient better if you investigate the fine grain of his condition rather than generalize about his illness. And that, it seems to me, is a wonderful guide for us today in thinking about how we too can take the Hippocratic oath in cities to do no harm and so to make our cities at least more resistant to the pressures of inequality. Let me say, since I have very little time, just to name two features of it that have spread over the blow in the last 30 years, which bear on the problem of urban design. These are features of capitalism which have to do with its time frame as well as its spatiality. The first of them has to do with the phenomenon of what has been called inpatient capital. That is investment in projects, principally in urban projects, in which the investors want a quick return to their investments in which they did not intend to become long-term owners. This behavior in the physical realm is based on a way in which inpatient capital works as stock markets have become globalized. People who invest in stocks and even in bonds are no longer long-term owners who consent to control companies but rather are sitting for short-term gains in the prices of shares. I'm just giving one example of how this works. In the United States, pension funds should be the most conservative of all investors in stocks and bonds. 35 years ago tended to hold stocks for an average of 46 months. As of last year, they tended to hold them for four months. Even the most conservative of investors have become sources of inpatient capital. That has had a profound effect on the way in which these are found. The second issue, a large change in capitalism that bears on our particular problem has to do with the phenomenon of chameleon institutions. So just to say in reacting to these patient capitalists, many managers and many institutions themselves re-engineer themselves over the short term changing their business focuses on how they're organized and where they're organized in order to meet the demands of investors who want short-term returns of investment. That is, the chameleon turns out to be a rather more attractive investment proposition than a change of any sort that affirms that at a fixed purpose, long-term goals meet another steady development. These are unsexy and tend to suffer. Now, both of these aspects, inpatient capital and chameleon institutions, have had an effect on modern cities. For one thing, they both push towards increasing the scale of cities. That is because investors prefer much more to invest in very large cities than they do in medium-sized cities or in small towns. The notion is that the federal character of very large cities is going to produce businesses which are likely to change, take on a chameleon quality and so be investable in.


President Joe Biden has warned that a significant cyber attack on the United States could lead to a real shooting war with a major power. It comes as the US has accused China of being behind cyber attacks on Microsoft's servers. Biden's latest remarks are directed primarily at Russia. I think it's more likely we're going to end up, if we end up in a war, a real shooting war with a major power is going to be as a consequence of a cyber breach of great consequence as increasing exponentially the capabilities. When I was with Mr. Putin, who has a real problem, he is sitting on top of an economy that has nuclear weapons and oil wells and nothing else, nothing else. Our economy is about the 8th smallest in the world now, largest in the world. He knows, he knows he's in real trouble, which makes him even more dangerous in my view. Never ever going to know, never have any notion of what you've done for us, the analyst.


Thank you for having me and thank you for teeing me up so well, Jim, with all the scary talk about cybersecurity and open source. Like I said, I'm gonna be reflecting a little bit on the last year in open source security. Last year, I kind of started off big with the log four shell cybersecurity vulnerability and it continued throughout the entire year. But this problem's been going on for a while. So I'll start out by introducing myself a little bit how I got interested in this space and then teed up with some of the things going on here inside of the Linux Foundation and in the broader open source community about open source security and supply chain security in general. So like you just heard, I've been working on and worrying about the security of open source projects for most of the last decade. I started my career at Google right in the wake of the operation Aurora attack on some of Google's internal infrastructure. Got to help out a little bit and watch the company build some of the best cybersecurity controls I've ever seen in the wake of nation state attacks like that. And then I started working in open source a few years later and I saw a huge shift in security posture that kind of got me worried. All those controls and preventions and source code integrity and provenance and metadata and software inventory like software build materials were missing in this new cloud native container centric Kubernetes focused world. And that got me pretty worried. I started working on a bunch of projects in that space. I found myself as a maintainer of the mini cube project having to look up how to do releases securely and open source. And I was basically told to go buy a Mac mini expense that put it under my desk, install Jenkins and then ship this binary to users all over the world to do their Kubernetes development. And that worried me a lot. So I started looking for alternatives that could help address this problem. This wasn't a very hot topic until recent years. So that's what I'm gonna be talking about. The transition to that why people started caring about cybersecurity and what we're doing about it today. So the state of open source security is actually pretty good. This is something I want to address a little bit here too. A lot of folks worry about open source security because we talk about it so much. But time and time again, the data always shows that open source security is better than proprietary software security or closed source security or any of the other options out there. So getting rid of open source is not an option that we can do. I just want to take that off the table at the start. But we're gonna talk about that a little bit too in some of that data. This last year has been pretty bad in the headlines. It started with that log for shell incident. There have been vulnerabilities every couple of weeks. There was even a very serious one in open SSL a month or so ago that drew a lot of attention. But there has been a lot of progress. I think everybody's probably seen these slides that show scary up until the right diagrams showing vulnerabilities and attacks every single year. I'm not gonna do too much of that. I'm not gonna scare everyone with those slides anymore. There have been a lot of wins and a lot of progress. So I want to make sure we focus on that because a lot of the people here in this room are probably responsible for that. But that doesn't mean it's perfect and we don't need to continue working or continue investing. So I'll talk about some of the things that aren't working and some of the ways we can continue making progress from here. So this is a rough high-level overview of the landscape of open source security. There's plenty more going on, but I like to call out some of these projects because they show kind of the ends of the spectrum and the different types of attacks and things that we have to worry about in open source security. Like I said before, this marks the one week or the one year anniversary this week of Log4Shell, the initial disclosure of that security vulnerability, and that really did shake the software ecosystem. That wasn't the first major software vulnerability in open source and it arguably wasn't even the worst, but it did present kind of a critical storm. The industry had been worried about supply chain security for that whole year because of other attacks, including on proprietary software, like the one on SolarWinds that happened the year before that. At the same time, the Log4Shell vulnerability was incredibly severe. It was about a worst case scenario. It was a critical vulnerability that was very easy to trigger and exploit in one of the most widely used libraries and one of the most widely used programming languages in the world. In fact, Log4Shell, the Log4Shell vulnerability was actually found on the Mars Space Rover, so it wasn't even just on this world. It was actually throughout the entire solar system. But as a positive, this event did lead to kind of a watershed moment in securing the open source supply chain. It drew continued attention that we hadn't seen before. Other attacks in that decade, things like the Heartbleed vulnerability, which led to an initial focus on open source supply chains, didn't really bring the carrying power and attention that we needed to really address this problem. Thankfully, these led to government regulations, mandates both in the United States and Europe and also here in Asia, because we already had this focus on the problem for so long. I'm hopeful that at this point, we can continue to make positive outcomes come out of these vulnerabilities as we address them. Right here within the Linux Foundation, this has led to a huge increase in funding and investment inside of the OpenSSF or the Open Source Security Foundation. Jim did a great job raising a ridiculous amount of money last year to help address this problem. They could just announce over 100 members in the OpenSSF now last week as well. So everyone here is paying attention, everyone is ready to help, we just need to help. Some of the projects here going on in the Linux Foundation where folks can pay attention are the SigStore project, which is part of the OpenSSF, as well as the overall SBOM initiatives. I like to call these out because they address very different risks. SBOMs, which you're gonna hear a lot more about from Kate coming up after this, power the software inventory systems that we use today. These aren't new, they've been around since, I think the initial version of the SPDX specification started in 2010, really focused on software licensing, trying to make it easy and safe to consume software for compliance. It turns out that knowing what versions of packages that you're using inside of your applications is important for way more than just licensing reasons. It's important for security as well. And then on the other end of the spectrum is the Project SigStore and other ones related to it like Salsa or S-L-S-A. These projects help make sure that your supply chain has integrity, that it can't be tampered with, that attackers can't take over, build systems, inject malware, and that the software in your SBOMs is actually the software that you're using and you can trust that data. So these two combined can present a trustworthy supply chain so you can make sure that your software is legally compliant as well as secure from attackers. So starting with S-BOMs or software bill of materials. These are very old, they're not a very new concept, they've been around for a while but they are seeing a huge shift in momentum. We've been doing polls at my company and through the different open SSF working groups to see how widely they're adopted and it's starting to pick up. A year ago, even though the projects have been around, you couldn't really count on, you could count all of the companies actually shipping them to their users on one hand in a lot of the surveys that we did today and that shifted rapidly because of the guidance and requirements from government organizations all over the world. This started early 2022 with some guidance from the US White House and an executive order earlier the year before that from the Biden administration but we're seeing similar ones here in Asia and all across Europe as well, requiring software bill of materials, requiring new cybersecurity standards to be implemented in proprietary applications. That push for security has really expanded the use case of this tooling that's been around for a while. So momentum is pretty hard to ignore at this point. Unfortunately, the S-bomb adoption isn't everywhere yet and we're hoping that it will be over the next couple of years because of the collaboration that we're doing here with tooling inside of the SPDX community and across the broader open source ecosystems just because companies need to produce S-bombs and need to consume S-bombs doesn't mean open source maintainers are really prepared to start producing them yet. It's important that we make sure that burden doesn't fall on maintainers that are already overworked and out of time, as Jim just said. So I wanna touch on this again. This problem is not unique to open source but because open source is open because we can collaborate on it, it does present a whole bunch of unique benefits that will allow us to solve these problems together. This is a common kind of thud or fear uncertainty and doubt point that's brought up a lot and folks worry about a lot when we keep talking about improving open source security. We can't get rid of it. It's too late. It's counterproductive to keep arguing about that. It doesn't help. All of the survey data shows that open source software makes up somewhere between 90 and 96% of modern applications today when you start a Hello World application. You're not building that from scratch.  You have to worry about securing the entire stack from the Linux kernel, the millions of lines of code there all the way up to your application that's serving traffic. Because it is open though, it means we can collaborate and fix all of that together. We don't need to secure all of that privately inside of our own companies. We can work together on all of this. We can't get rid of open source. So let's take advantage of these properties to help secure it together. So some of the wins over the last year. There's been a huge amount of progress just in the last year alone. I think this is a little bit unique because we're seeing a lot of progress driven from standards and legislation that are coming out rather than innovation happening first and then standards getting ratified at the end like traditionally happens here. But cybersecurity tends to take that, tends to require that in order to make progress, unfortunately. I like to think that we can always be proactive and introduce security measures before we really need them. But sometimes it does take these huge security incidents and government regulations to force progress across the entire industry. So diving into these first two with a special focus on what's happening here inside of the Linux Foundation. We've participated here in all of these White House meetings inside of the US and with every other government agency to help shape these standards. When you do have standards and regulations being driven this way, the risk is that they come out wrong. These policy makers are not open source developers for the most part. They don't understand software. And frankly, seeing some of the initial proposals is a little bit terrifying. You can definitely tell that these people do not write software in their day-to-day life. So they are looking to the organizations like this, to companies like your own and to every open source maintainer for input on how to do this correctly. Software developers don't wanna do things insecurely. They want the time, the tooling and the funding to do it the right way. So helping shape these standards is incredibly important. On the standards front, SPDX late last year, early this year, just got ratified as an ISO standard, making it an international standard that can be used, that can be used for compatibility in sharing software, supply chain metadata across companies and around the globe, which is a big win for unlocking adoption across different companies. The open SSF on the resourcing side, resourcing and funding is not required. It's not the only important thing to fix open source security, but it is still critical. People need time, people need tooling, people need hardware, they need CI systems, they need funding to run fuzzers in order to secure these open source libraries. And the open SSF has been a great organization to help provide that so far. Some other highlights, there's a huge effort this year to start requiring multi-factor authentication. There was 80 million GitHub repositories that you mentioned before. Each need to be secured and against phishing and other tampering attacks. As those repositories keep growing, we're gonna struggle to keep up with that. So efforts like multi-factor authentication that can completely prevent entire classes of attacks like phishing are critical there. And through the open SSF we've funded and staffed a whole bunch of giveaways of hardware tokens to open source maintainers to get them the tools they need in order to turn technologies like this on. There's also a multi-language package manager working group that is bringing together folks from the NPM and Python and Maven Central and Rust repositories to talk about how to roll out these package manager security improvements together. It's the first time folks from these different language communities have gotten together to talk about security. And it's been a huge win so far this year. And of course you can't forget the introduction of Rust into the Linux kernel. Memory safety bugs represent a huge, huge outsized amount and percentage of critical security vulnerabilities in every language that is written in memory on safe code. The Android team at Google just released some data last week showing that up to 70% of the critical vulnerabilities in every Android release were due to memory safety. Since the introduction of Rust into the Linux kernel there have been zero memory safety bugs in any of that new Rust code. This is another pattern of introducing a new technology to get rid of an entire class of vulnerabilities so developers don't have to learn and don't have to fix each of these security bugs line for line as open source continues to rise exponentially. So unfortunately there is no single solution to securing open source. Let me start to talk about some of the different initiatives that we need to increase investment in going forward. All of these attacks, all of these problems are very different and unfortunately we can't just take all of that money the open SSF has raised and buy security with that. We don't know how to convert dollars into security yet so we do have to figure out exactly what is going on. We need to look at the root cause not just the symptoms of these security problems that are cropping up in open source figure out how to address them at those roots and it's not going to be one simple fix it's going to be a lot of hard work. And from the company perspective open source security is product security. These investments aren't just for GitHub they aren't just for all of the code on the internet. Funding these improvements letting your teams spend time building fuzzers letting your teams spend time improving security upstream does impact your product security directly. So we do have a long way to go even in spite of those wins. There are a lot of risks to open source code that we need to address because it is open source and a lot of these can address because it is open source. We can fix things because of these unique properties. One of the most challenging ones is the contribution risk. We see this pop up all the time at typo squatting maintainers getting their accounts taken over. One of the great things about open source is that anyone can contribute to it. Unfortunately for anyone that spent a significant amount of time growing up on the internet you quickly realize that not everyone on the internet is a nice person. And just because a project has a bunch of GitHub stars or looks like it's widely used doesn't mean you can necessarily trust those maintainers. We need tooling to better identify malware before it gets consumed inside of our organizations and inside of further upstream projects. Bad actors aren't going to go away on their own. And even though funding isn't the only thing important for open source security, it is still critical. There's a lot of funding available. It's a distribution challenge, making sure that funding can get to the folks that need it and that it can actually be used successfully to improve security in the projects where that funding is distributed to. Knowing all of that, finally wrapping all of this up, knowing all of that requires a deep understanding of the open source that is used inside of companies that is used inside of your projects. A large project like Kubernetes that's probably used in almost every organization here today isn't a single project, even though it's a single organization on GitHub. It has thousands or tens of thousands of dependencies that are maintained by different sets of people. If you don't know about all of those, then security vulnerabilities in those lower level libraries can have just as much of an impact as the final application itself, like we saw with Log4Shell at the end of last year. So using Sbombs, building high quality software build materials, improving software inventory can help us find those critical projects that are farther down the stack, that also need security investments, even though they're not the ones getting all of the attention at these events. So investing in Sbombs and investing in accurate Sbombs is gonna pay dividends for security across all of open source. So where do we go from here? We've talked about some of the wins, some of the problems that we're still facing. A lot's happened this year, but we're not done yet. Well, we need to continue driving education and awareness. If people don't know about the security risks, people don't know how to do things the secure way, then we're gonna keep facing this problem every year as new developers get on board, as new programmers start writing code and shipping it on GitHub and in other open source projects. The education efforts they were doing, 10,000 signups for the secure software development course are massive in educating the future generations on how to build code securely from the start. And we need to continue driving Sbombs usage. Sbombs require a flywheel, people shipping high quality Sbombs and people demanding and making use of the data in these high quality Sbombs before they're really gonna see equity across consumers and suppliers. We need to build better tooling both to produce accurate Sbombs and to give organizations insights into the data they get from Sbombs so they don't just become another security checkbox that get required when procuring something and then throw it into a bin and never looked at it again. Once you've figured out how to do that right, we need to start doing that by default. Developers don't have time to do all of this manually every time they do a release. We need to make Sbombs invisible so we can actually secure the long tail of open source with them. We'll have a bit deeper here before we wrap up. In order to make Sbombs work for everyone, we need to invest in tooling. We need to make that tooling accurate and we need to make the data useful. There's kind of a gap here between open source and proprietary software today or just because something is open source, you can look into the dependencies and get a pretty good idea of what's inside of that. But as software flows through open source products, those products then being used to build other source code, we're losing data, we're losing fidelity there and there's a lot of gaps that we have to fill in in the software supply chains to get a good graph for source code all the way from the top of the stack down to the bottom. This is gonna require composition tools so that we can stitch these Sbombs together as they do transfer across organizations and across projects. And we need to continue improving the standards. The standards are great today but as they start getting used where to start figuring out gaps and the way they get used and to prevent different use cases from this data. Naming is one of the hardest problems in computer science and there's so many different ways to name the same package that they might look like completely different ones and prevent us from doing accurate vulnerability queries and making use of the data in Sbombs. So we need to make sure that we don't think of these as just the checkbox. The way we're gonna do this is with secure by default tool chains. If we do all of this right, folks shouldn't even have to think about Sbombs. I hope a year from now or two years from now we don't have as many talks about Sbombs. I'm sorry, Kate, but I hope that all of this is just built into compilers and tool chains and package managers and we can stop talking about it and we can just go on with our day and build software securely. We need to embed this into tool chains directly. That's some of the work that we're kicking off in the open SSF starting this year. So thank you for having me and thank you for helping improve the security of open source together.


I'm not gonna lie, I rushed this one, but this is just this one, so you're gonna qualify expert. All that needs to happen is for you to shoot three out of the four, so as long as you're hitting one of each type, you're good. Shooters at the top, need that rain. Your next drill, 25-year-old out there, moving 30 again. The bigger gap between 14 and 15, then there's both of the other ones. Nice. Oh yeah. I would probably suggest this drill. Load your bags.


If you could please introduce yourself. Oh yes, sir. Hi, I'm Sarah Cody. I'm the Historic Preservation Chief for Miami-Dade County. I hope you are. Archaeologists have identified over 16,000 cultural resources in the state of Florida at risk due to the effects of climate change. In Miami, a mere six feet above sea level on average, a natural phenomenon known as the kingtides is causing historic preservationists to rapidly develop solutions for the mitigation of sea level rise and storm surge. The scientific name for a kingtide is a perigee and springtide, and it's essentially when the orbits and alignments of the sun, the moon, and the earth all coincide. And kingtides are the highest predicted ocean tides that take place in the calendar year. They're exceptionally high tides. They cause local flooding, mostly along low-lying coastal areas, and because the average daily water levels continue to rise as the oceans rise, high tides can reach further and extend higher than ever before. And sea level rise induced by climate change is expected to lead to more frequent and higher kingtides over time. Kingtides are part of larger climate change, right? The tides are getting bigger and stronger and more frequent during this part of the year, something we also saw just this week. So I'm actually recording this after the devastation of Hurricane Ian to Southwest Florida. And here in Southeast Florida and in the Miami area, what we're seeing is that the kingtides are actually supercharged by the storm. So we're seeing increased water levels because of the cumulative impact of both Hurricane Ian and of the kingtides. And obviously with climate change, as we all know, hurricanes will get bigger, stronger, and potentially more destructive. The kingtides, they make visible sea level rise encroaching on these historic and prehistoric sites. Without the kingtides, the visualization of the risk would not be as possible. It makes everything more of an emergency. It's more pressing. And it helps other people to understand that sea level rise is happening now and it's not happening in the future. Are the kingtides part of any larger environmental changes within the climate crisis and if they are, how so? Yes. So as we all know, human activities are the main driver for climate change. And in essence, what we're seeing with kingtides is exactly what climate change has done and will continue to do. Increase the sea and groundwater levels. So with that comes increased storm surges, inundation of lower line wetlands, eroding shorelines, and saltwater intrusion into estuaries and aquifers. The kingtides in Florida in particular create massive issues when it comes to red tide and dangerous toxic algal blooms that spread from one coast to the other across these inlets from Lake Okeechobee. So they have created wider environmental problems that are disconnected. So in one way, the toxic algal blooms and eutrophication that we have from sugarcane runoff from pesticides shouldn't be related to climate change, but the kingtides are affecting this hugely in Florida. As a coastal community, Miami and South Florida in general have always been vulnerable to flooding. But we've become more vulnerable to the effects of climate change and sea level rise. And climate change and higher kingtides present a unique challenge to our cultural resources. And that's why the Miami Indian County Office of Historic Preservation has performed a vulnerability assessment to identify which of our historic resources are the most at risk for flooding. And we're currently conducting a vulnerability assessment to do the same for archeological and paleontological sites. One of my favorite sites to visit and work on in Miami-Dade is the Bill Bags Cape Florida State Park. So this park is famous for its lighthouse. People love lighthouses, right? It has the beautiful daymark, which is just the white paint. And I'm interested in preserving this site because it's so much more than just the lighthouse, right? We have thousands of years of occupation ranging from a tequesta middens at the site through its historic buildings. This site was also really important as part of a saltwater railroad. So this was a way that freedom seekers traveled south and east to the Bahamas across the water. So people were trying to escape and find their freedom. And I think that aspect of the site is really interesting, right? And that's something we're losing. Another aspect of the site is that you can really see the impacts of climate change at the site. So there is a US Coast Guard survey marker that was placed there in 1855. And when the survey marker was placed, it was placed on dry land, obviously. And when they relocated it in the 1980s, it was actually underwater out in the middle of this game bay practically. So they have moved it back to dry land. But who knows how long that area will be dry and above the water for. Built in 1825 and sending 100 feet tall, visitors can reach the top of the Cape Florida Lighthouse for a view of Biscayne Bay in Miami by climbing 109 steps. The Cape Florida Lighthouse and its surrounding areas within Bilbag State Park have a long and complex history. During Spanish Florida, this area was a refuge for self-liberated enslaved Africans and a launch point to reach freedom in the Bahamas. After the US acquired Florida from Spain and began the Seminole War, the lighthouse was attacked and its light was extinguished between 1836 and 1846. It was fortified and rebuilt in 1847. While it was briefly recommissioned between 1978 and 1998, it was ultimately replaced by the offshore Fowley Rocks lighthouse in 1878. The Cape Florida Lighthouse and its surrounding areas have already felt the effects of sea level rise, with historic preservationists working hard for decades to ensure it remains standing for future generations. I care about all historic sites and prehistoric sites, but in particular the ones that I care about the most are the ones that are called tequesta sites, particularly in the Everglades and around downtown, that there has been attempts at protecting not always successful and the future of these sites, many of them right on the edge of the Miami River or right on Biscayne Bay. Dating back roughly 2000 years, the Miami Circle was uncovered in 1998 by archaeologist Bob Carr. Before colonization by waves of European and American settlers, South Florida was stewarded by a number of indigenous groups, including the tequesta. Like other cultures native to South Florida, tequesta people were a complex, non-agricultural society who developed ceremonial architecture, were skilled artisans at carving wood and bone, and had wide-ranging trade networks, with some artifacts from the Miami Circle sourced from places as far away as modern-day Missouri and Georgia. The Miami Circle is thought to be the ceremonial complex of a larger tequesta settlement spanning both sides of the river and was the center of an intense preservation battle during its excavation. It is now a public park under the care of the Florida Division of Historic Resources. Archaeologists believe that tequesta people, whose population was already dwindling at the time of European contact, were driven to Cuba by the Spanish. Seminole and Mikosuki people, as well as other survivors of Spanish occupation, continued to use the river for travel and trade into recent history. The site continues to hold a deep spiritual significance for many indigenous people throughout the Americas to this day. It's really difficult to kind of pick one site or pick a few sites to say, oh, we're most interested in preserving this one. All of our designated sites are significant in some way, otherwise they wouldn't be designated. And, you know, the county, we have so many significant historic cultural archeological and paleontological resources that date as far back as 10,000 years. So with that said, I will say that the Deering Estate is a really good example of a significant coastal site. In our vulnerability assessment, it was ranked as the second most vulnerable historic site in the county. And what's particularly interesting about it is that it has very significant historic and archeological resources within the same site. So understanding the political challenges of a sea level rise initiative, working with the Deering Estate to create a pilot project, where we could really show people the plight on county historic resources would be a really valuable way to highlight the significance of these sites and their vulnerability in a changing climate. As a primary tourist attraction in one of the county's most exposed sites, the Deering Estate would really provide an excellent platform to develop some kind of sea level rise outreach program to an audience that's already receptive to the goals of historic preservation. And our office is actually currently working with the Deering Estate and with the University of Florida on a grant funded project to do exactly that. We're going to be doing free modeling of a portion of these states and showing exactly what the site would look like as the sea levels continue to rise. The Deering Estate is an historic house as well as a nature preserve located in South Dade, Miami Dade County. The Stone House was built by industrialist Charles Deering in 1922. In addition to these resources, the Deering Estate's grounds include archeological sites dating to the Seminole War, Florida's Spanish colonial era, the Tequesta Inhabitation of South Florida, and even older time periods. One of Miami's best kept secrets, the Cutler Fossil Site, is also found on the grounds of the Deering Estate. The Cutler Fossil Site is a sinkhole with both paleontological remains from Florida's Ice Age as well as evidence of later human use as a hunting ground. Its human use dates to roughly 9,700 years ago, a time period known in Florida as the Late Archaic Era. The Ice Age animals found at the Cutler Fossil Site include the remains of an American lion, dire wolves, cave bears, and other megafauna. While many of its oldest sites are located on the Atlantic Coastal Ridge, an unusually high outcropping of limestone, the Deering Estate is nonetheless close to sea level and most of its cultural resources are extremely vulnerable to the effects of climate change, hence its participation in Miami Dade's pilot study. While not all of Florida's cultural resources can be saved in their entirety, archaeologists and preservationists are working hard to defend them from storm surge, record sites in detail, and preserve their stories. Because I'm at a university, I have had the fortune of being able to apply for grant money that has helped create the Coastal Heritage at Risk Task Force, where the acronym is CHART, which has brought together people from the Tribal Historic Preservation Office of the Seminole Tribal of Florida, members from the Mikosuki Tribe, as well as academics from across different institutions, museums, county archaeologists, county preservation boards, as we try to assess what sites are most at risk, and more than anything else, we want to tell the stories of some of these sites before they go underwater. We're trying to assess what sites will disappear and what sort of stories do these sites represent that people otherwise don't even know about as these sites disappear underwater. So here at the Florida Public Archaeology Network, one of the things we try and do annually is actually visit a number of archaeological sites every year during the Kingtides. And what we're hoping to achieve with that is to view what the archaeological site or the historic building might look like in the future as sea levels rise with climate change or what the site might look like with significant flooding during a major storm event. So when we go out to do these visits, sometimes portions of the site can be totally inaccessible due to flooding. Sections of the site might be underwater. It makes it more difficult to do our work during a Kingtide because of obviously the increased amount of water on the site. One of the major programs that the Florida Public Archaeology Network has to address and raise awareness of climate change is our Heritage Monitoring Scouts program. So this was developed by Sarah Miller, who's the director of our Northeast and East Central offices. And it empowers people to document the impacts of climate change to archaeological sites, historic buildings, historic cemeteries, really any of our heritage sites that are being impacted by climate change. Participating in that program is a great way for people to learn more about the day-to-day effects of climate change on specific sites near them. Our past has so much to do with our future, and we have so much we can learn from our past. There's so much more to understand about what came before as we look forward and we think about how do we deal with all of these environmental justice issues, these climate justice issues today as climate change encroaches on us. Things, whether they be an archaeological site, a historic building, or a historical cemetery, all of these things are preserved because people cared enough about them to reach out to legislators, to reach out to leaders in their community and say, this is something that is a critical part of my identity and it needs to be preserved for the future. When we think about climate change, we think about it as something that's going to impact our future, maybe, and it's obviously impacting our present, but it's destroying evidence of our past as well and we're losing the information about who we are and where we come from. It's very important for people to understand that historic preservation is not insular. What I mean by that is historic preservation is an essential part of any field or any project that deals with the built environment. We have to start to get away from thinking of historic preservation as trying to save a particularly beautiful building or a particularly beautiful site and start looking at historic preservation as how can we leverage the power of our historic cultural and archaeological sites in a way that creates better, more equitable and more resilient communities for our residents.


Hey, welcome back everybody, Jeff Frick here with theCUBE. We're at our Palo Alto studio today for a CUBE conversation and we're excited to have from Druva, a very hot company in the storage base, Dave Packer, the VP of Corporate and Product Marketing from Druva, welcome Dave. Thank you, it's great to be here. I appreciate it. Absolutely. So last week, I'm sure you were there, we were there at AWS re-invent. Right. What'd you think? I was a great event, especially for Druva, it was one of these events where we came out as one of the top storage vendors for AWS.  We were in two of them in the top five. And another thing was when we announced our AWS Marketplace introduction of our Phoenix product line which focuses in on server data. And so that was big as we were one of 11 vendors that AWS picked to be part of that program. And what it does is allows organizations to actually go directly to the Marketplace, purchase our product, use it, and basically on a regular basis, renew or do whatever they want to do. So it's actually, it's a new way of doing it. It's really exciting actually. Okay, well let's back up a couple of steps for people that aren't as familiar with Druva. A little bit the history of the company. So you guys are your storage, cloud storage and backup and replication, security. Give us kind of the four one one. Yeah, so we characterize Druva as being cloud information management. Ultimately, we were founded in 2008. Our focus has really been on, how do you help businesses, especially today where data becomes so much more fragmented and dispersed? How do you enable businesses to still have the visibility, the accessibility, the availability of their data? So when you think about it, organizations are faced with end users on laptops or using cloud services or using mobile devices. You have servers. You just have data going everywhere.  There's pesky words like governance, compliance, those types of things. Exactly, I'll come into play still. So the legacy models, which were really designed to be on-premises and try to address those things have fallen short because of the way data's changed so much in the last five years, kind of where it's located and everything. So as Drew was matured as a company, our focus has really been to help businesses and enterprises get that visibility, that manageability over the data in a way that they can kind of bring that all together and get a holistic view on a worldwide global basis if necessary. Right, and you guys took a kind of a cloud approach early on, you kind of saw the benefits of doing that versus kind of the traditional way. Right, so we're really fortunate because being founded in 2008 gave us a huge advantage, which was cloud was just becoming something at that point in time, which from our CTO's office point of view was this is something we need to grab onto and run with and we had the foresight to see that this was gonna be a huge market opportunity. And so we developed to be 100% cloud native. And so what that means is at the end of the day we can provide businesses not only kind of a global reach for their data centers and where they want their data and how they wanna manage it because there's a lot of data regulations out there today that require maybe data to be in Germany or data to be in the UK or the US. And so we wanted to make sure that companies couldn't adhere to those. But also it gives us a form of elasticity and capacity that's unmatched by anything you could do on premises. And I'll give you a case in point is one of the big challenges, especially when you start talking about compliance and you start talking about governance and legal data handling. One of the big issues companies have had in the past is they've depended on systems that require them to build a ton of infrastructure to support. They didn't understand really what it would take to make it happen. They wound up babysitting it a lot. And so the cost just skyrocketed. In the cloud, you can kind of like take that off the table completely. And the elasticity is there so you can get things like real time indexing of data. Things that you wouldn't be able to months before to do the premises. And so we've been able to bring these to bear so companies can have these different ways of managing information all on a single data set. Which when you really think about it, in the old world, I'd have a data set for my archive, I'd have a data set for my backup, I'd have a data set for my governance capabilities and for my search, we merge that all together, single data set, no replication, all in the cloud. Interesting. So I think a big thing that came out of the re-invent show was a couple of people such kind of AWS 2.0, that clearly enterprises have bought into the vision. We saw Andy Jassy and Pat Gelsinger on stage together earlier this year talking about a partnership. So clearly enterprises are now, they get it, right? I'm curious, your perspective is kind of the, one of the early knocks on cloud was the whole security conversation. And how that's evolved over time from your early days where it was probably a big sales objection that you had to overcome to now, in fact, one might argue that it's actually more secure to be at a third party. Yeah, it's an excellent, it's an excellent point. Because I'd agree, three, four years ago when I first started with a company, I actually took on enterprise security as kind of one of the areas I was managing to help the kind of our sales team. And it was a big issue. And it was one of these things where the conversation always came back to security, my data's more secure on premises. But there's two, I'd say there's two things that have evolved. One is, and I'll make a couple points on this, is one is that 99% of the largest breaches in the last three years have been all on-premises systems. And you can go back to something like Sony, which was two years ago, and see one of the things that I challenge is, I talk about it's kind of like the M&M problem, right? Where companies have invested really heavily in security at the perimeter, but internally it's not as strong, right? There's a lot of clear text transmission happening. So if a hacker or even an internal person wants to go in and start misappropriating information or going after it, they have access to all these systems and pretty simply can move from one system to the next. A lot of people don't realize that Sony had to actually have a HIPAA breach notification because when that breach happened, they went into the HR system, they were able to pull data that was relevant to healthcare information and that required a breach notification on that. And so we see that that's one issue companies face. The second is that if I were to go through my top 10 list of customers, they are government contractors, pharmaceutical companies, medical companies, all companies that are heavily regulated and you have a high or maybe a low tolerance for security risks. But in our conversations with them, what they've come back and told us is that when we do our own infosec reviews in our own systems and we started thinking we've got to stand up systems internationally, maybe multiple data centers in the US, there's no way that we can staff it and address all the security issues with the rate of change that these things are happening at and they've fully embraced the cloud. We have customers that back up into GovCloud, which is the AWS specifically for US government agencies. Right, Teresa Carlson's group. Right, and so we're right at actually, Druva's right at the tail end of being FedRAMP certified as well. So these are all things that really attest to how strong the security is in the cloud that everybody's having this confidence. And so it's less of an inhibitor. I think where we do occasionally see it is more internationally. Companies are still trying to get a feel of cloud and what that means to them. It's just funny to me because there's so many places where you need to focus on your competitive differentiator and you outsource the parts that are not your core business. And how can you compete in James Hamilton's thing on Tuesday night with James Hamilton, which I'm sure you attended and he just talked about the scale and their networks and laying cable across oceans and all these things that you can't do if your core business is selling insurance or selling cars or doing whatever. Right, well there's a difference between an InfoSec team of 10 and an InfoSec team of 2,000. Right, right, right. It's funny to me. So just another question, Begg. So you're in the storage business and you partner with Amazon. Amazon S3 is like one of their core products. So how does that work with kind of a third-party value add service like you guys within the context of a cloud provider like in Amazon that's got some of the core basics already? Yeah, so that's the way to understand, Druva, is what we're doing is we're helping you get your data, consolidating it and getting insight into that data. And so let's have just a pure storage play. We definitely use Amazon storage, we use S3, S3IA, we use Glacier, we implement what's called auto-tiering. So you're using all that stuff kind of under your covers for your infrastructure. So it's under, we look at, best way to think about it is we look at Amazon like an operating system. And so the operating system provides some database functionality, provides storage functionality, memory, compute. And we're optimizing all those things to provide a customer an application that provides the value that they're looking for. Like Amazon can't manage legal holds for terabytes of data through the legal process. We handle that for customers. Amazon won't provide compliance monitoring. Like as data's coming into our system we can look for healthcare information, we can look for other sensitive data types, PII, PCI type data, we can then provide alerts and information back to an administrator or a compliance manager about what is there, right? And so it's about those insights. And that's why, you know, Druva as a company, why we have done so well. It's, you know, we just were funded back in September for our E-Round, 51 million dollars led by Sequoia Capital.  So I knew at least for 80% of my data was, even if I didn't know everything about it, at least I had some confidence. Today that confidence is down to like 20% because it's, well, it could be an Office 365, it could be in Box, it could be in Salesforce, it could be, you know, you name it, or it could be on somebody's mobile device, right? And if I don't know where it is, that's gonna create big issues for me. And I'll talk about, you know, Advocate Healthcare in Illinois that just in August received a 5.5 million dollar fine for HIPAA violation. Largest HIPAA fine ever allocated out to a company, right? And the reason is- Which basically means they exposed. Right, so, you know, they had to give a breach of notification because healthcare data was compromised, right? And so what companies are starting to realize or experience is that these regulations are becoming tighter. They're becoming much more stricter oversight of them. And probably the scariest one for a lot of organizations where there's a lot of question marks is GDPR, which is the new EU, kind of a sensitive data protection regulation that's analogous to HIPAA in the United States, but covers the whole EU. And anybody who's doing business in the EU has to know, you know, whose data is where, who has it, what the sensitivity is, what the risk is, what the security is on that. And it's unique in the EU because they have a right to be forgotten clause, which means like, hey, if I call and contact you and I say, I don't want you to have any information about me anymore, you've got to go through and forget where all that is and expunge it, right? So it's a real, it's a real challenge. So those are the- You guys deal in those types of problems as well. Right, so you know, we're helping companies get those types of problems to solve too. And then there's the availability cycle.  You know, how do we make sure that data's recoverable, right? And so we solve that challenge.  And IOT and mobile data that's just, you guys have seen that thing just explode, right? Right, right. Yeah, it's funny, we do some stuff with GE and everybody loves to talk about the airplane engine data, right? When the airplane's flying, it gives off so many terabytes, blah, blah, blah. But you know, as it's crossing international borders in Europe, where's the data supposed to go? I think that's kind of an interesting question with data sovereignty. German data, French data, Spanish data. Right, right. Yeah. And those are the sovereignty issues are actually a real big challenge for a lot of businesses.  And you know, we have some best practices companies should follow, especially when they're thinking about adopting cloud in like Germany or, you know, we get questions about Russia or China or Singapore, you know. And each one is, I got its own little nuance, you know. And you have to understand those variations and why the laws were written the way they were. But you know, to your point, you know, yeah, a plane flying, transmitting data, who knows, right? And just to kind of come full circle on the AWS show and the fact that the enterprises have adopted that. So this brings up the concept of the whole hybrid cloud, right? Because there's still legacy applications, legacy vendors, legacy systems that are still running big mission critical applications on-prem. Even if the company itself is doing either USB test dev, now it's Greenfield projects starting to migrate historical things to the cloud. How does that change a challenge for the folks managing that data and how have you guys kind of seen that evolution impact your business? Kind of this hybrid cloud notion, if you will. Yeah, so you know, when we look at hybrid cloud, you know, we fully understand that for the foreseeable future, you know, enterprises are gonna have a lot of workloads on-premises. You know, especially real high transaction systems. It's hard to move those to the cloud. There's a lot of legacy infrastructure there, technology sets. The pesky thing, like the speed of light, which is very slow. Yeah, exactly, right, right.  We have a large portion of our customers, that's all they do is go direct to cloud. We do provide the ability to have caching servers, which is basically a software appliance. Companies can solve that on-premise. It'll cache locally, so the data doesn't have to go direct to clouds. You don't have to worry about the latencies and all those other issues. You can do recovery directly out of the cache, things like that. So, we have ways to address that for those types of environments and those types of systems. One thing we do do, though, that is unique. If you have a very heavy VM environment and you want to do disaster recovery, we can take those images and spin them up in the AWS cloud before you, as well. So, that's a, our Phoenix product actually allows you to take those. We convert them automatically into AMIs. You can configure them for failover. And then we'll actually push them into customers' AWS accounts. So, you get around a lot of the security, manageability issues of failover. So, it's actually, it's a very kind of elegant way of handling that migrations test of replication. So, we're coming to the end of our time and we're coming to the end of 2016. We're answering the calendar here in a couple of weeks. As you look forward to 2017, whether some things you're excited about, what do you look forward to? What's kind of on your roadmap for the next 12 months? You know, I guess the things that really kind of get me kind of like get, you know, passionate about what we do is that I think there's a lot of opportunity to get more from data. That's, you know, you think about where the cloud, if you could massively store a whole enterprise's data set, right? What you can actually pull from that, you know? Whether that's through machine learning, whether that's digging in, search, mining. I think what I'm starting to see is something that companies have been trying to sell for years actually coming to a solution, right? And that's a, I think between that and some of the new technologies we see kind of evolving and microservices, et cetera. Also, the cloud becoming even more cost efficient for customers. You know, one of the things you talked about security, the other thing customers typically will talk about is the cost of cloud. Wow, it's too expensive. It's way more than what I would pay for on premise. And what we try to explain to people is that if you were going with the legacy model that has been retrofitted into the cloud, if you take something that's expensive on premise, you put it on the cloud, it's going to be twice as expensive, right? That's really what's burned a lot of people.  It's all about getting, compressing those cost efficiencies to make it more beneficial to customers. I think we're going to see a lot more of that next year where companies start waking up to, wow, this is actually much more cost effective way for our business. Right, and you can do so much more. Get out of that legacy mindset if you will. All right, Dave. Well, thanks for taking a few minutes to stop by on a Friday morning, a little bit of rain in Palo Alto, which we need more and more and more rain. So he's Dave Packer. I'm Jeff Rick. You're watching theCUBE. We'll catch you next time. Thanks for watching.


if you can bring breathing technique into your life even in a small way you'll see the benefits very quickly so if you can try and learn to breathe through your nose and that perhaps is the biggest thing that people find hardest so just take a couple of minutes every day and breathe through your nose focus on it just breathe through your nose then breathe through your chest and take it in baby steps and incorporate the idea of breathing to start off with into your life and then if you can put aside a few minutes a day as I said for me it's beginning and end of the day because I've got no distractions to practice that breathing so that when you realise the benefits of what it feels like when you're calm hopefully you can put that into practice when you're not feeling so calm when you're feeling challenged you can actually do it with ease


I'm going to show you how to use your Chromebooks built-in web camera to scan QR codes. This is super, super easy. So first thing, on your taskbar at the bottom, go all the way to the left of the circle so you can bring up all of your apps. You can either type camera in your search or just pop it up and it should show up right here in this first screen. Click on the camera icon and remember this is the built-in one. It will open up and you will see choices in the center and you want to go over to where it says scan. So when I click the scan button, it'll automatically default to document. It's trying to read a document. So you can see it trying to read a piece of paper. If I click on the QR code button right there, a QR code scanner comes up and when I swipe my code into it, it will automatically pop up on my screen. And all I have to do is click that. I can also copy it, but if I click the link, it will open up Chrome and go directly where that QR code led you. Super easy. My final tip would be to suggest that every time searching for that camera can be a pain. So if you just go to the bottom when that camera app is open and you two finger press click on it or right click and pin it, that will make it stay on that task bar and you will never lose it and you don't have to go searching for it.


Good morning. So, in the last lecture we looked at how to incorporate the effect of external mass transfer. We are talking about a particle, a catalyst particle around or there is a film around it, this surrounds a catalyst particle which is a hypothetical film and the concentration varies inside a film. Outside of film, the concentration is a bulk concentration. At the surface, the concentration is C A S and inside a particle, of course you have the reaction taking place. You may have effectiveness factor being significantly or being substantially lower than 1 or it can be equal to 1 depending on what is the pore structure and all that. But we are not worried much about that. We have, we are worried about the external mass transfer resistance. So, in that case, the overall rate can be given as if you have a reaction which is first order then R A is equal to minus K C K R C A divided by K C plus K R. Let me quickly tell you what we mean by K C. K C is the mass transfer coefficient, mass transfer coefficient and K R is the reaction rate constant, rate constant. And of course, we are talking about a bulk concentration which would be C A B there because everything we are expressing in terms of the bulk concentration and that is the main purpose or motivation behind deriving this equation. Now, again like I will repeat like if you write expression in this particular form, the units of K C and K R should be same. So, the mass transfer unit, you remember D A divided by delta, what is the unit of D A? D A is say meter square per second or centimeter square per second, delta is meter. So, unit of mass transfer coefficient is meters per second, it is meter per second. Now, the K R that is a rate constant of the first order reaction, it should be in this particular case it should have the same unit as that of the mass transfer coefficient. Now, the K R here is the rate per unit external surface area, rate per unit external surface area. So, if it is a volumetric rate constant, the unit is second inverse whereas, in the case of in this particular case, we have the unit which is equal to K C right fine. Now, let us go ahead and of course, we further try to interpret this by saying that R A is equal to C A B divided by 1 by K C by 1 by K R sorry K R and this is a negative sign here because, we are talking about the rate of reaction for A. Now, depending on the relative magnitudes of these constants reaction is either external mass transfer control or reaction control. So, if K R is very large then R A is equal to K C C A B where C A S is almost 0. If K R is very small or yeah if K R is very small then it is governed by the reaction, the overall rate is governed by the reaction it is going to be like this. In this case C A S is equal to C A B right the rate is expressed in units moles per second meter square very important and meter square is a is a is a cross sectional area external surface external surface and not the internal surface. So, always remember that we have been talking about different surface areas for internal mass transfer, internal diffusion sometimes we express our rate constant in terms of internal surface area which is significantly large substantially large compared to the external surface area. But, right now this is this has a unit of flux that is moles per meter square per second all right. So, let us go ahead now and try and understand is external mass transfer in more detail. Now, external mass transfer suppose external mass transfer is important now it is the rate given by this particular expression. Now, this is a very simple expression where K C is very important is a mass transfer coefficient how do we get it this expression looks quite similar to a first order rate equation when reaction is intrinsically kinetically controlled right adsorption is negligible desorption is negligible at all other adsorption coefficients are smaller. So, the denominator is unit. So, R is equal to minus K C. So, again the expression looks quite similar, but meaning is quite different ok. Now, this K C here in this expression is different from the K R from the K R. Now, K R we know K R is a rate constant which is of course, a frequency factor has a same unit as that of K R. So, if it is per unit external surface this will also be per unit external surface area then exponential minus E by R T. Now, it is very easy or it is it we know how to calculate this or we know how to determine this through the experiments in laboratory I do experiments at different temperatures I get plot for 1 by T versus L N K and this plot the slope will give me delta E or E rather and then you have the intercept giving A of course, this is semi log plot L N K versus 1 by T right. So, you know how to get K R you know how to get A delta E by performing experiments at different temperatures in laboratory and get a value of K R. So, for a normal reaction which is controlled by intrinsic kinetics I do not have any problem designing a reactor. Now, if it is external mass transfer which is playing an important role how do I design a reactor that is a question. So, first of all you need to know the external mass transfer coefficient the value of external mass transfer coefficient under the conditions that you are doing the reaction in fine.  Now, it depends on which parameter as now always remember this relationship easy to know what K c is dependent on. As I said depends on the diffusion coefficient and it depends on delta that is film thickness and this film thickness is in turn the function of say turbulence or how well is the mixing what is the flow pattern. Now, who is going to decide all this this is this in turn decided by the reactor geometry flow patterns are decided by the reactor geometry actual flow rates. So, in term of dimensionless numbers which is the dimensionless number which is important in this case it is a renewal number n r e or r e and is another number which is something to do with the properties like viscosity, then density, then diffusion coefficient this is a dimensionless number in mass transfer which is called as smith number right. So, the mass transfer coefficient depends on these parameters or these particular factors the smith number, renewal number and the reactor geometry. So, there are correlations for mass transfer coefficients. So, what people do know normally that perform experiments under different conditions they know that mass transfer coefficient is going to be function of renewal number is going to be function of smith number. So, what I do is that perform experiments in the laboratory at different values of renewal number different values of smith number under otherwise similar conditions get a functionality get the dependence and that is a correlation for the given reaction geometry. See, I have a tubular reactor say a fixed bed reactor this is the correlation for the mass transfer coefficient. I have a fluidized bed reaction this is the correlation for the mass transfer coefficient. In every correlation you want to see these two numbers, but that correlation is specific to the reactor of interest fine. Now, let us make an analogy because you have probably learned heat transfer before mass transfer. So, we know there is something called as the Nusselt number in heat transfer this is something called as Nusselt number how do we define this? This is something to do the convection or heat transfer coefficient. So, it is nothing but H which is the heat transfer coefficient H then some D now D is a characteristic dimension it can be a diameter it can be a diameter of the tube by k. Now do not do not confuse this k with the rate constant we are talking about heat transfer here. So, this is nothing but a thermal conductivity and this D is not diffusion coefficient this is diameter or some dimension this is the conventional heat transfer coefficient right and this is the Nusselt number which is given by this particular ratio of product of H in D to k. So, Nusselt number tells you about the heat transfer coefficient now this Nusselt number is related to again two numbers a non number and something called as Prandtl number. Now of course, this is not just the product we will see that but there is something some raise to m some m and a some constant a. So, this is a correlation this is a correlation so, you will always see a correlation in this particular form now from reactor to reactor from geometries to geometries these constants would vary right. But the otherwise the terms are same terms are same now you may ask me a question that suppose this is stagnant medium there is no flow. So, Reynolds number which is functional velocity is 0. So, does it mean that there is no heat transfer at taking place does it mean that heat transfer coefficient is 0 that is not true because I have a stagnant medium say water I am heating it from one side it is going to get transferred right. So, for very low values of Reynolds number or for a stagnant medium you have a relationship given by 2 plus a into R e raise to n P raise to m. So, this is a number 2 it so happens that at very low value of Reynolds number Nusselt number becomes equal to 2. Now for mass transfer you have see this is an analogy heat momentum and mass. So, this dimensionless numbers see there is always a counterpart for one number in heat transfer to another number mass transfer. So, which is a counterpart for Nusselt number in mass transfer the counterpart is a number called Sherwood number Sherwood number very important what is the counterpart R e no there is no counterpart. So, R e is there in mass transfer also what is P R P R is C P mu by K where K is thermal conductivity C P is specific it mu is viscosity for P R there is a counterpart in mass transfer which is nothing, but we already mentioned it that is mid number which is given by mu by rho d where d is now the diffusivity d is diffusivity and mu is viscosity. So, mu by rho is kinematic viscosity sometimes you denote it as this mu divided by d I hope it is clear. So, there is an analogy for Nusselt number the analogous number in mass transfer is Sherwood number for P R this analogous number in mass transfer that is Schmidt number. So, like this correlation I will have a similar correlation in mass transfer given as Sherwood number is equal to 2 plus A into Reynolds number raise to M and Schmidt number raise to M. So, I got a relationship and this is the relationship that I want this is something that I am going to use to estimate or to calculate the value of K c because that is what is required for my reactor design. And these constants are known for the given geometry. So, what I will do for example I want to design a fixed bed reactor say fixed bed reactor which is packed with the catalyst and there is a gas or fluid or rather liquid going inside. I will perform experiments well planned well designed experiments to estimate or get a values of Sherwood number for different values of Reynolds and Schmidt number. And once I have this I can estimate the values of this like what I do for normal kinetics I determine rate constant I determine activation energy I determine frequency factor from the laboratory data. So, I am doing a similar thing here I am generating I am generating laboratory data by doing experiments under different conditions that is at different values of Reynolds number and Schmidt number and getting the value of Sherwood number I do not need to do experiments under reactive condition can be a non-reactive also. So, simple example say I will take naphthalene balls naphthalene has a tendency to sublime. So, I will just pass a gas at a certain temperature I will see what happens how much naphthalene gets vaporized what is the rate at which it gets vaporized that depends on the mass transfer camphor. So, the many possibilities you can get a value of mass transfer coefficient. So, need not be the reactive experiments conducted under reactive conditions it can be experiment for just mass transfer just mass transfer from solid to liquid or solid to gas. So, doing such experiments you determine the values of by doing some such experiments determine the values of this a n and m and get a final correlation for the fixed bed reactor and not just fixed bed it can be fluidized bed. So, I have a certain correlation. So, typically for a fixed bed reactor now this value if you are doing it at very large or relatively high velocities then this factor becomes very high compared to this. So, I can neglect this two. So, I may write this as say 0.6 and just typical value for a fixed bed reactor with cylindrical or rather with circular cross section 0.5 S3 raise to 0.33. So, this is a correlation this is a correlation for Sherwood number or in other words this is a correlation from which I determine the value of mass transfer coefficient. How do I determine? I can calculate the reward number for given velocity I can calculate smith number I know diffusion coefficient I know characteristic dimension. So, I know the mass transfer coefficient if I know the Sherwood number how do I define Sherwood number by the way I did not tell you that sorry. So, Sherwood number is something similar to Nusselt number. So, here instead of convective heat transfer coefficient I have a mass transfer coefficient k c into some characteristic dimension if it is a fixed bed reactor with spherical catalyst particles then it is d p divided by instead of conductivity now I have diffusivity I have diffusivity. Now, this is diffusivity here do not get confused with diameter I will use this for diameter while defining Nusselt number, but now it is diffusivity. So, many variables and not many alphabets that is why this is you have same alphabets coming again and again all right Sherwood number. So, once I have the value of Sherwood number from the correlation I know the diffusivity let me denote it as d a for component a I know the particle diameter I can get a value of k c all right now let us see k c depends on what. So, as I said before let it is the something due to the flow pattern flow patterns are decided by the reactor geometry and velocity. So, let say I have a cylindrical reactor a fixed bed reactor how do I determine. So, which which are the parameters or factors or variables rather that I can play with to manipulate value of k c. So, for rate constant for the reaction I change the temperature because I know Arrhenius law tells me that if I increase the temperature k increases drastically. Now, here which are the parameters that I can play with I have already told you Reynolds number and Schmidt number. Now, Schmidt number is what mu by rho d these are all properties of the components that I am using I cannot really change them of course, for the gas phase diffusivities and viscose it is are functions of temperature they vary, but of course, not significantly we will see that later. So, which is the main parameter that I can play with the Reynolds number and Reynolds number in this case the Reynolds number that we are going to define is u that is velocity meters per second d p is a particle Reynolds number. So, let me write it as d r e p particle Reynolds number d p right rho divided by mu or u d p divided by mu kinematic viscosity right. This is how I am defining Reynolds number you know definition on d v rho by mu instead of d now I have d p here because of particle Reynolds number because I am taking particle radius or diameter as a characteristic dimension here to define Reynolds number because that is the that is the most appropriate dimension here as far as the mass transfer coefficient is concerned because I am talking about mass transfer coefficient around the catalytic particle and not for the mass transfer of wall to the fluid inside fluid to the wall I am talking about particle. So, now it is a particle diameter that is the more important fine. So, this is Reynolds number. So, this u u is something that is going to decide a value of s h and hence k c why because s h is a strong function of Reynolds number you already seen that r e raise to 0.5 and what else in all this again there is another parameter that is coming again and again which I can play with is d p is the d p here is the d p here. So, let us put everything together and see how the mass transfer coefficient varies with d p and u together. So, s h is equal to k c right into what d p divided by d a is equal to 0.6. Reynolds number u d p nu raise to 0.5 right into smith number raise to 0.33. So, how is the dependency now this diameter is coming here also here also. So, s h is equal to sorry let me not write s h let me write k c is proportional to u raise to 0.5 and if you take d p here d p raise to 0.5. In other words u by d p raise to 0.5 here it is minus 0.5 because d p comes here. So, this is the relationship or proportionality that I see k c is proportional to u by d p raise to 0.5. Of course, remember this is for fixed bed reactor cylindrical geometry and circular cross section. It may slightly vary here and there, but then I am just showing you the importance of these parameters as far as external mass transfer is concerned.  Now, let me do experiments in laboratories. Now, I know which is a factor that is affecting or making more impact on mass transfer coefficient.  So, I do experiments in laboratory for a fixed bed reactor at different values of u by d p I change u I change d p I do it right. And I plot this graph by getting the rate under otherwise similar conditions. Now, you may ask me like it may vary along the length and all that again same principle probably I will just take small length small length of the catalyst or small amount of the catalyst. So, for that I need to plan experiments very well. So, that I do not bring in other effects. So, under otherwise similar conditions if I perform experiments for different values of u by d p raise to half sorry raise to half and determine the rate say r a or minus r a rather. What am I going to see? Can we predict the nature of this graph? It will come down like this or we go like this remain constant or it will go up come down. What can we say? If I have very small value of u by d p what it means is the mass transfer coefficient is going to be very small. I have a reaction taking place now I am talking about reaction that is taking place on the catalyst inside or outside. Why? Because catalyst is responsible for the reaction I am doing the experiment here say cyclohexane dehydrogenation, cumene decomposition, ethyl benzene dehydrogenation whatever. There are so many reactions possible. I am doing those reactions and I am determining the rate. Now, this where I am going to value of u by d p is very small means if I want to compare intrinsic reaction rate and mass transfer which is going to govern the rate it is the external mass transfer that is going to govern the rate. Why? Because value of external mass transfer is very small remember r a is equal to minus c a for a first order reaction 1 by k c plus upon 1 by k r. So, if k c is very small this is going to govern because this is very large this is going to be 0 or negligible compared to this and the reaction will become mass transfer controlled.  The value of k c will increase the rate will increase because k c will come in the numerator as I go on increasing the value of u by d p k c will increase the rate will increase. So, it is going to be like this I go on increasing now look at the nature then look at the train what is happening here? It is going it is attaining saturation here it is not increasing it further after certain value of u by d p I do not see a rise in rate can you say why or can you explain why? It is all because of the fact that after some value of u by d p the k c becomes so large that now the reaction is controlled by k r.  So, if I change u by d p only k c is changing and because of which I am getting increase in rate, but after some time this k c becomes so large that it will overtake k r and k r starts controlling. So, in this region I have external mass transfer control and in this region I have reaction control. So, this is how it is going to be like. So, you it is quite similar to what we have looked at before as well like for intraparticle diffusion remember that you have two regions if you plot d p versus r and you see that this in this range you have intraparticle and this say you have reaction is a reaction control it is in this case you have intraparticle diffusion control. So, something similar that you are seeing here here it is reaction control here is a mass transfer control. Now you may you may ask me the question where is the intraparticle it is here right now we are just clubbing all those other effects in this remember this graph only tells me that if I am here the reaction is not controlled by external mass transfer it is controlled by either reaction or internal diffusion or adsorption desorption whatever. So, I have already told you while doing this analysis I am clubbing all those effects I am putting together all those effects in this reaction term and external mass transfer is treated separately. Now, for a first order reaction tell me like what will happen if I have some effectiveness factor. So, it is very simple what will I do is this the rate of the reaction is C A 1 by k c plus 1 by k r. Now, if I want to incorporate effectiveness factor also what will I do I do not need to do anything much I need to just do this why because you already seen this is the definition of eta definition of eta. Now, this what I have done is I have isolated effects of now I may call this as k r dash because this is intrinsic when the molecules are near the catalytic site and this is taking care of the pore diffusion effects this means the eta value and why it appears C again look the way they are appearing in this equation. Why eta is appearing as a product and not like this separately 1 by eta or something like that why because diffusion and intrinsic reaction they go in parallel whereas, reaction and mass transfer they are in series. So, when they are in series then you see the effects as to separate terms then parallel you see their product. This is how you should read equations this is how you should read or interpret the final equation that you get see there is no point in biasing this equation is a much in this like if you understand it very well you would be able to write it properly. But of course, remember this is for the first order reaction. So, we have so we know what is mass transfer coefficient we know how it changes with velocity and particle diameter and how do we know that reaction is controlled by mass transfer resistance or by intrinsic reaction. So, now once we know that reaction is controlled by mass transfer coefficient or sorry external mass transfer then how do we design a reactor. So, let us look at that I have a fixed bed reactor which is packed with the catalyst I want to determine the length or height required or weight of the catalyst required to achieve certain conversion. This is our problem this is our problem finally it boils down to this every reactor engineer reaction engineer should think of a reactor design as his final objective all we are doing is to somehow to be able to design this particular reactor that we have in mind fine. So, if I am in this particular region u by d p raise to point 5 I am here then how do I design the reactor. What is the rate equation r a is equal to minus k c a divided by 1 plus k c plus 1 sorry 1 by k c plus 1 by k r and k r is very large compared to k c. So, it is going to be minus k c c a right now what is the unit by the way what is the unit of rate here the unit of rate here we have been using that right from the big thing the unit is moles per meter square second here. Now, I want to design the reactor. So, let me write a mass balance this particular term looks quite similar to the reaction term of course I have to take care of the units fine. So, let me take the differential balance it is like like my normal plug flow reactor what is the equation for the plug flow reactor it is going to be like if I take the balance coming in going out and delta z becoming almost 0. What I have is d f a by d z divided by ac that is cross sectional area plus r a into ac let me define all these terms is equal to 0. Now, it would be very clear for see in normal plug flow reaction plug flow is like d a f a by d v d a f a by d v plus r a sorry it should be minus here is equal to 0. See remember like for a normal plug flow reactor d a f a by d v is equal to r a this is what we have been using reaction engineering part 1 right see the difference here it is the same equation except the fact that instead of r a I have r a into ac why because the unit of r a here is per unit area and here it is per unit volume right. Now, look at this units here f a is moles per second this has unit meter cube right. So, it is same as r a into ac right. So, same as this. So, r a also has a unit moles per second meter cube. So, this fellow this particular term will also have the same unit moles per meter cube second, but you already say that r a has the unit moles per meter square second I would not I am I am multiplying it by ac to bring it to this unit. So, what is the unit of ac? Ac has a unit meter square per meter cube. So, how do I define ac? Ac is the mass transfer area per unit volume volume of what? Volume this volume volume of the contactor volume of the contactor volume of the reactor. So, this volume is volume of reactor. So, how much mass transfer area I am providing per unit volume of the reactor that becomes very very important right. So, how so ac now let us talk about ac, ac is interfacial area or mass transfer area empty area rather. So, in the reactor I have this particles which area am I talking about I am talking about this area which is at the external surface right. So, it is easy know I know how many particles I have I know what is the particle diameter I know void age for a fixed bed. So, from that I can calculate this. So, it is nothing but the property of the reactor and the packing that I am using the catalytic packing that I am using. So, it is something that is given to you or it needs to be found out depending on what is given and what is to be found out right. So, for a given the extent of conversion I can get a value of ac that is required or for ac given I can calculate a conversion. So, it is quite similar to what we did for reactor design again go back to your reaction engineering part 1 for the given volume I calculate conversion or for given conversion I calculate volume or later what we did was like when was late was expressed per unit weight of the catalyst I said fine if you have conversion given you can calculate a weight of the catalyst required or if the weight of the catalyst is given you calculate a conversion. Now, here in this problem I am calculating the area required for the mass transfer for the given conversion or for the given area I can calculate a conversion. Now, this area depends on what area depends on the amount of catalyst that I am taking it depends on the particle diameter and a wattage because it is per unit volume of the reactor volume the reactor right. So, this is the meaning of interfacial area per unit volume interfacial area sorry I should have interfacial area per unit volume nothing else is important here because the entire reaction the rate of the reaction is governed by the external mass transfer. So, it does not depend on the pore structure it does not depend on the activity of the catalyst I have already I have already concluded by doing experiments that it is governed by external mass. So, nothing to do with the temperature of course, like temperature will slightly make an impact on diffusivity and all, but catalytic activity pore structure pore volume tortuosity adsorption coefficients none of them are making impact on the rate it is external mass transfer. So, which are the parameters then remember the equation for the mass transfer coefficient Sherwood number ok. So, Reynolds number and Schmidt number for the given properties diffusivity viscosity and density it is the velocity and the particle diameter all right. So, A c is a very important parameter here and when if you look at the equation you have this which is similar to a normal plug flow equation only difference is I have this correction here term of A c because I am expressing R A per unit area. So, let us go ahead and derive this further F A can be converted to concentration this can be written as say F A F A will be multiplication of flow rate and concentration right. So, it is this can be written as D C A into E U divided by or D by D Z of C A into U U is the velocity it would be volumetric flow rate, but since area is there volumetric flow rate divided by area is velocity plus R A into A c is equal to 0. You can have a separate notation for R A because the way we are defining right now it is per unit area as long as you remember the units of R A that are being used you do not have to worry much about it. So, here I am multiplying it by A c means it is per unit area fine. So, I can take U out of the derivative if it is constant now you know when it is constant in there is no pressure drop velocity is not changing as we go from inlet to outlet temperature is not changing isothermal conditions. So, many assumptions are there, but if I am allowed to do that then I take U out D C A by D Z plus R A A c is equal to 0. Now, suppose I substitute for R A now what is R A? R A is equal to minus K c into C A minus C A S right remember C A C A B minus C A S sorry C A B here it is C A S linear difference between these two and if it is external mass transfer control you know approximately this is equal to 0 right. So, since C A B is very large compared to C A S this becomes 0. So, I can I can say this as C A B minus C A S sorry C A B here it is C A S linear difference between these two and if it is external mass transfer control you know approximately this is equal to 0 right. So, since C A B is very large compared to C A S this becomes 0. So, I can I can say this I can simplify this further rate fine. So, let us substitute for R A what I get here is minus U D C A by D Z is equal to K c K small k c that is the mass transfer coefficient C A B or C A C A B C A B here and then A C. Now, I am working in terms of bulk concentrations. So, earlier also I should have written C A B let me do that C A B bulk concentration C A B here everywhere you can make C A B is a bulk concentration that I am working with fine. So, this is a very familiar equation right. We know as Z increases C A B goes down. Now, this looks like our normal rate equation for a first order reaction only difference is there it is intrinsic rate constant. Now, I have a mass transfer coefficient multiplied by interfacial area per unit volume right. So, I can solve this equation analytically C A by C A 0 is equal to exponential minus K C A C divided by U into Z. This is how the concentration varies of course, you need to know the boundary condition what is that boundary condition at Z is equal to 0 C A is equal to C A 0. If I use this boundary condition for this differential equation is O D ordinary differential equation I get this profile of concentration along Z. Let us all are known once I start my experiment or reactor right. So, this is quite similar to what we have got before for a first order reaction in a plug flow reactor only difference that you should remember is that meaning of these constants are different mathematically they look similar fine. Now, so as the length increases from 0 to 1 what is L L is a length of the reactor C A by C A 0 goes like this a typical plug flow type behavior I can I can convert this equation I can convert this equation to conversion form and you know how to do that 1 upon 1 minus x is equal to K C A C divided by U into L that means for the given length what is the conversion. So, substitute L for Z in that equation in this equation substitute L for Z in this equation what is C A C A is equal to C A 0 minus sorry C A 0 to 1 minus x all right again I can write B here sorry I keep forgetting that, but it is like you know the meaning of it C A B is equal to C A 0 clear. So, I get a relationship between length and conversion length and conversion I need to know K C I need to know A C I need to know U velocity. Now, this K C will again I have spent enough time how will you get this K C K C will be obtained from the correlations Sherwood number Sherwood number fine. Now, so you have this correlations given may be we can solve some problem later, but before that let us quickly look at one nice example given in Fogler's book all right before that like let me talk about every time we have been talking about porous catalysts and all that, but then if you remember first or second lecture on catalytic introduction to catalysis I said that different types of catalysts apart from porous there are some non porous catalysts also where you can have a gauze or you can have a plate or you can have a monolith where pore diffusion is not important reaction takes reaction is so fast or you do not need many many catalytic species or atoms for the reaction to for them to catalyser reaction. So, I can just take a gauze a wire gauze or I can take a foil or which reaction will take say alcohol to aldehyde silver gauze you have ammonia to nitric acid reaction is instantaneous, but then there is a competition between intrinsic reaction and mass transfer because once the once the reactant reaches the catalytic site reaction takes place immediate. So, most of the times these reactions are governed by mass transfer they are governed by mass transfer. So, you have to identify the area for the mass transfer how much area you are providing and that is good enough or that tells you about a rate of mass transfer if you are increase the mass transfer rate or overall rate because rate is governed by mass transfer you can increase the area available or you can increase the overall number and you may get higher rate fine. So, there is one example or a case study that is given in Fogler's book which is quite good. So, I thought I will just discuss that now you have two reactors say fixed bed reactors I want to put them in series and I will I will realize certain conversion here right I will realize certain conversion here. Now, instead of using this reactors in series I may use them in parallel I may use them in parallel right what are you going to see now parallel means I am going to split my feed in two parts equally and these reactors are also of equal length let us assume that and I do this. So, the conversion here x 1 and conversion here x 2 are they going to be same are they going to be different if at all x 1 is higher than x 2 or x 1 is lower than x 2 we need to see that. Now, we already seen in reaction engineering part 1 that for normal reactions which are governed by intrinsic kinetics this does not matter for a first order reaction this does not matter irrespective of fact that you put it they put them in series of parallel you get a same conversion.  And if the reaction is controlled by mass transfer the same volume now which is provided for the same feed it is likely that this combination is going to give me higher rate compared to this of higher conversion compared to this so x 1 is going to be greater than x 2 you can prove that. So, x 1 is likely to be greater than x 2 so do it as homework let us see what happens look at equations for the write down the equations the plug flow reactor or whatever like you are not plug flow your tubular reactor just now we have derived that you just derived this know this is the equation that we have derived now this equation you write it for every reactor reactor 1 reactor 2 sum them up and similar thing you can do it for these two simultaneous and see what happens you will realize that because the velocity is higher here than here for every reactor here individual reactor the mass transfer coefficient is large because the number is large the reaction rate here is higher compared to these two. So, this is going to give you better conversion than this all right. So, we will continue this discussion later and we will solve some examples thank you.