So that's the idea today. I'm gonna be explaining what we've done to actually get into where we are right now, how we are adapting and how we're checking to see how we can make this better for all developers to contribute more. A little bit about myself. Felipe Rubin, I'm a chief architect at CINT. I'll speak a little bit about CINT to give you guys a little bit of context. I've been working with Drupal for the past four years. Since my company started working with Drupal, basically do a lot of large deployments of Drupal, large organizations. So we have a considerable amount of developers, a number of developers in the organization. So CINT, a little bit about the company. We've been doing, like I said, large deployments of Drupal. We've built about 400, Drupal 6, and now Drupal 7 websites across the globe for different organizations and then maintain those sites as well. We have about 300 what are called talents in Drupal so that goes with developers, testers, web designers, screw masters involved in our Drupal project. So that's a large number. And they are spread out across different development centers in Brazil, Argentina, and China. By the way, I didn't say I'm Brazilian. Our company's a Brazilian company, headquartered in Brazil, but offices in all those three locations in the globe. And we have some names here, the people that are part of the company and part of the community. So the whole point of here, it started with with thinking about how we are having our developers involved in the community and what is the potential that we could have them more involved and contributing back to the community. And that has been, there was a session from Angie. I think it's a Montreal or somewhere in Canada session that she did. And she brought this data from Drupal.RDO where we have just a very low percentage of the active users in the community are actually contributing to core. So just 0.1%. And there's a lot of things being cooked in order to reach what they're putting as our target to get to a full 1% in 2014. So that was part of one of the reasons we start thinking about, well, maybe we could be part of this as well as part of our organization.  Basically the majority of the enhancements or each ideas or maybe just fixing, I think don't get back to the community. Just to be honest, I mean, most organizations, and depends on the customer as well. I mean, we as Drupal shops depends, sometimes the customer, like we just saw in the keynote, the customer doesn't want to contribute back for some reason. There's a fear that his code is coming back to the community and that what's gonna be with my competitor, et cetera, especially with large organizations. So it's really a little bit tricky to convince some organizations to do it, but it's really important that we try and talk to them. Of course, we're not coming back with the code for whatever is their business logic or whatever is part of their business, but trying to get whatever is common and make sense to be contributed back. But still, there's a lot of that doesn't go back to the community. There's a lot of frauds, we see thousands of websites. So Drupal is powering several websites in the globe and we don't see that coming back to the community so much. With that in mind, what we want is really to create ways to have almost all developers trying to aim high, really high target, so about 300 people trying to contribute somehow to the community, right? Either coding, translating, documenting, so there's several ways. So we started discussing this and what we could do to make this happen. And for the talk today, what I put together is three things that we've done to make this happen. The first thing is really to try to identify why this is not happening organically, why this is not so natural to developers so they can spend either their work time, like trying to make things faster through all the work, or off work, like off the business hours, really getting engaged with the community and all the learning that they had by doing those projects, trying to contribute back. So why is this happening? So that was the first thing and I'm gonna be talking to you guys about. The second one is really, once we identified why this is happening, we went ahead and we customized our own Drupal ladder. There's a session happening, I think this afternoon, specific about Drupal ladder, I'm gonna be talking a little bit about that, both part of our inspiration too, but we basically customized that and I'll explain why we did a little bit of customization for that. And once we started running this program within the organization, we started measuring the results and really adapting and how we can make this successful throughout the next few years, right? The first thing is why is this happening, right? What is it with the developers and contributing back? Does everyone wants to do that or yeah, I'm part of the community or I don't have the sense of being part of a community. So I'm talking about more Brazil, a little bit detached from Europe, from the US, the whole community that is more active in those countries or continents. But what's going on with the developers and this feeling about contributing back? So start interviewing some developers and there is this feeling of guilty that we're not doing more, we're just getting things from the community using for the projects and not really putting that back so they are eager to contribute back. They have this guilty sentiment but they're just sitting over there in the couch and not really contributing so much. So we identify that they wanna do it. The second thing we realize that some developers or a considerable amount of developers they're waiting for the organization to do something to really get them out of inertia, to get off the couch. So it's kind of a, it's a generic or generalization but there were some developers that are waiting on the company to do something to kick it off or to get this started. So I think, well, this is important so let's think about it. And with those two things, realize that some developers were not getting motivated to continue either participating in the community or even working the project to make a Drupal better in general. So they just would just do their work and would not excel or be better every day. So start people getting distracted and not being committed to the Drupal project. So those are the main things that we found out interviewing the developers. And then we move ahead and start discussing what is preventing them from contributing besides this feeling and waiting for the organization to do something. And then looking at the community, looking at the O. A little bit of these you're down to where should I start, right? There's a bunch of documentation. The O is excellent. I personally think it's great. All the documentation where there has been redesigned. There's a bunch of steps that you've got to follow but it's quite easy. But it's still for newbies, for new developers, they just look around by themselves and if they don't have any help, they kind of start getting lost. What, where should I start? Where? And doing what, first thing first, right?   So there's several ways. You start looking at this bullet list in the O and imagine you're a new developer working with Drupal for quite a long time but you want to contribute back and you got to do by yourself.  I'm sure we can just go ahead and start but some people, they need to get some help to really get things faster. Because as you start doing things, you face a roadblock and you're by yourself and then kind of wanted to give up and so you get distracted easily with so many things that you got to do. So that's another thing we found out. Although there's a great documentation, there's a great step by step, there's still something that needs to be done to get things started and rolling. Another thing which is funny too, but I still, developers starting or they're used to just do their code and just expose internal organization with their coworkers, they're used with their friends and coworkers and then there's a sense that now I have to expose my code to the work, right? And it's kind of, yeah, I don't feel comfortable with that and yeah, we know of course, maybe I'm not doing the best of the code but you know, that's the sense. I mean, that's the idea to really get people to get you better. But still there was this feeling that I don't want to share what I'm doing out there. I'm more comfortable in my couch here, just with my friends helping me out. So we also learned that language is a bit of a challenge too. So despite some other countries, Brazil and I think Argentina too, we don't learn English from the very beginning kindergarten, start learning English as a second language out of the bats, getting better every day. But still, you only get to learn English as you get into your high school. So that's where you start getting more fluent and sometimes it's too late for to really get a better fluence. And once you get into the issue queue, start, I mean, some discussions in the trads, sometimes get fancy or goes all the way discussing the issue in several details using different words. So again, kinds of a little bit of a roadblock for developers that doesn't have, the fluence in the language, right? So there's a bit of a challenge too, I don't think. I think we have, we've got to have one language. English has been working fine, so it's more like something we've got to do at home work to make this better. But it's a challenge. So if we have ways to try to overcome this challenge as well, it should help. Another thing we realized, by again interviewing this Brazilian team, an Argentinian team, it's a, and I believe in the West, I forgot to mention, I believe in the West for the past four years. So I kind of get a difference. I got the difference between cultures, US and Brazil. And to be honest, we don't grow up with the habit or with being incentivated to actually be part of something else, something bigger, regardless of if it's softer or just helping out people somehow. So we don't grow up, especially our generation down in Brazil. We didn't grow up with the sense of contributing so much or helping out so much. Of course, there's exceptions. We see a lot of things happening in Brazil. There's a bunch of people helping, but it's not as big as I see here in Europe, as I see down there in the US as well. So there's also something that it's more, in turn, it's way back that we got to work out to and really help them to get off the couch and make this happen. So that was the investigation we did. So let's analyze and see why this is happening and let's try to come up with some ways. And that's what we did next. We started to think about how we could overcome those challenges and start things to become better in terms of contribution to the community. Another thing that I did mention here that we tried to do something not structured in the past, just getting people together and it wasn't successful. So we had some experience to create a more structured program. And that's what we've done. And it's funny, at the same time it's very good because the inspiration itself came from the community. Myself and Gilmore here, part of my team, and another guy called Caillou. We were at Drupal Con Denver in March, was our first Drupal Con. Although we've been working with Drupal for quite a long time, we haven't actually joined any Drupal Con for the past years. So a shame on us. But being over there and getting, what you guys are getting here, I don't know, how many of you guys is the first Drupal Con? Okay, so you guys will see, I hope you guys will see what is so great about being here and what changed for us being at this first Drupal Con. And that was one of the first things that we kicked off besides other things within the organization. So hopefully you guys will come out of this week with a different view of the community too. But it was great, seeing all the energy happening, everything that we just saw in the keynote, everything that we saw in the opening session was started bubbling to our minds and see we've got to do something about it. There's so many things happening and we're not part of it. We do have our internal community, this amount of developers, 300 developers, and we could do so much more. We could be part of that, right? So we got to do something. We start discussing in Denver in the very few days, the very initial days have been, of course, it's part of the community too. And at the same time, the Drupal Ad Initiative was being kicked off in Denver. Discussions happened before, a few months before. I think it started back in November last year. But the Drupal Ad Initiative was being kicked off. And it's basically, as you guys, again, if you go to the next session about Drupal Ad. And I think in the opening session this morning, they mentioned a little bit about it. It's basically ways for you to start sprints with your team and getting people together in the city and really doing sprints to contribute to core. So it's more specific about core Drupal Way and really having steps where people can, once you start this one, you can go to the next and so forth and so on. So we also got this as an input for us. So what about if we just go ahead and do the Drupal Ad. And implement that right now in Sao Paulo, in Brazil. And we felt that we're not at the level yet. Just go ahead and having developers contributing to core. We felt that we should start a little bit earlier or get one step back and look at the modules to the contribution of modules. There'll be something more comfortable for the developers. And the three of us, besides what the guy's been talking, we happen to be kind of a Call of Duty addicted. And I'm not being paid to do an advertise for this, but there's a new version coming in November. Very excited. And happens to be where we play quite a lot back at the time as well. So beer, Denver, the whole energy of the community, feeling like there's so much we could do more, we could do about it. And also associated with this Call of Duty addicted, we've been playing quite a lot. Was part of this idea. And having fun, as you guys, again, for the newbies, the first time you guys here in Drupal Con, you'll see, I hope you'll see throughout the next couple of days, it's just about having fun throughout the experience. So we thought, well, it has to be fun as well. Right, cannot be something that a, it was really discussion around, it shouldn't be something that organization is structured in like one day a week, everyone just go ahead and do it. Somebody's gonna be supervising that. So it has to be something that is more organically created as well as having fun most of the time, right? So this idea was born. Coming back again to the Call of Duty, Black Ops, what we thought about is creating a program called Call of Drupal Blue Drops. So having me playing pool down there, one of the bars in Denver, and we figured, well, what if we create something with that?  And we all like Call of Duty, it's a very famous game. So what if we do a little joke with that and create something for them to feel motivated to participate? And that's what we did. We basically created a program that idea, the main idea is to really get people into a sprint and really start contributing together. So bringing people, the whole original plan was to get people together on a Saturday. So forget about the work during the week, so just join us on a Saturday. We're gonna be sitting down together in a room. We're gonna be helping each other with peer programming. We're gonna be helping you get started. And by the way, there's this website here, which if you fix a bug, you're gonna start getting some points. I'm gonna show you guys. So we built this website kind of just a couple weeks. We built this Call of Drupal Blue Drops. I don't have the copyright for the image, but we just tweaked some image of the Call of Duty. But the whole idea was starting to build on top of what we could do, what we call as battles. So instead of a sprint, we just a code name would be battle. So we would be joining on a Saturday to battle together against those bugs. And so it's starting to have fun just boiling down the idea and starting to talk to some developers. What do you think about this? Do you think, would you join us? Would you be part of this game with us? And of course, I just wanna make this note as well. It's not like competing, although it's having fun. There's gamification involved. We wanted to bring these elements too, because it's collaboration, that's the whole idea. But with some fun, everyone likes to be part of a game, or most of the people like to be part of a game. So we built this website. Basically, Kayu started this one. I've been helping numerous too, with being the testers and analysts for the requirements, and started to bring more people in for the design as well. But it's quite simple, and I can navigate a little bit later on this one. But the idea is to really have a section where you have the announcements, what's going on, the battles, what's next battle about. A battle, basically like I said, would be a sprint on a day that would be more focused on fixing bugs of this list of modules, or could be a battle specific about the core, or could be a battle, everyone should be creating a new module, or everyone should be translating, or should be documented. That would be the focus of that battle, and on that day, you would get extra points if you focus on what is the battle about. But it could still work out in different things as well. So the whole idea was that, and a game was basically an issue. So we just get issues on DO, just put it here with the link, but that's it, so we can track who's doing what. And we started putting together a leaderboard. And the other nice thing that we did is basically starting putting some tutorials, basically again, links to documentation that already exist to facilitate them. So the dynamics was, or were, we sat down together on Saturday, we started with what we call some sergeants helping out, explaining the website, what it should do, and really once we learned this one very quickly, just go to DO and start playing with DO, get information from there.  Let me, so we start with the first battle. Let's do something, that's the operation, but Killer was the first Saturday. You get double XB points, I don't know who plays Call of Duty here, or played the past a little bit, okay. So there's something similar as well, in some weekends they put together, if you play in that Sunday you're gonna get extra points, or I forgot once. But still, so we got the same ideas. And pretty much the whole gamification, giving badges away, so we're starting discussing, wow, that'll be cool if we start putting some t-shirts. So we did a t-shirt for the first battle, just with the Call of Drupal, Blue Drops logo. But once we start getting badges you can actually stamp them and walk away with the badges. So start like, wow, that'll be so cool, and you guys would love that, and he did. So we started designing some badges, like if we're a bug fixer, we're gonna get points and you can get a badge, model creator, and then we start building like translator, so there'll be basically this. So this is Caio, he's kind of on the top of the rank right now, or second. So he created a module, actually, I think he created three right now after we started the program. Although he has created several modules within our projects, but only now we started having like three modules from him in the community. So once he created a module, we decided it was gonna have like a thousand points and you get a badge right off the bat. So it's not as simple as fixing a minor bug. So we worked out in a logic for those points. Bug fixer, to get this badge, you have to fix five bugs, and then, I mean, so on and so forth. So the idea is that you could always change that. The same thing with the call of duty, you can always change and add more bags, new challenge. The idea is to be flexible enough so we can always keep adding more badges and keep people motivated to contribute. Let me walk out a little bit of the site itself. But yeah, basically the screenshots that I'm just gonna look good here. But there's some layout issues here, but basically, this is a list of tickets or basically the issues that were just copy and paste here. We're still working out some things to basically prevent duplicating information, right? So DO and also here. So we're starting to do some, we're starting to do, we're starting to do some automation for importing the issues. So we prevent having the same information to different places as well. So there's a lot of things happening for improving this experience. What else, once you, if there's an issue that you wanna work out and you wanna make sure that we track here, you add a new game, just basically just add what is the title, the status and some details that you wanna discuss. So that helps as well throughout the dynamics on the Saturday, on that day to have people look at the site. And eventually once you close a battle or close a game actually, you start getting points. So that's the leaderboard. So people, some people just fix some bugs. There's two guys that are working the most here. And there are the sergeants too. I'm gonna be speaking a little bit about the sergeants. Some people that are not actually coding so much, they're more supporting. So the senior guys are more supporting the other guys to actually get this done. And one of the challenges that we had as well, as I told you guys, there's three development centers. Myself, Gilmore based in the US, and Kai as well, guys in Brazil. So there's the remote, right? Being remote and still making this happen. So the sprints for Drupal Ladder, their ideas to get to get everyone over there. There's no remote participation so much. Of course you can't have it as well. But there was a bit of a challenge on that too. So Kai was based in Michigan, Louisiana, New Jersey, New Jersey. And those guys are in Brazil just near Sao Paulo as well. That was the first battle. So there was a bit of a challenge with that too. But we use our IRC. So that was great to use the channel. So create a channel for us to share experience as we go through the day. And the other part of the gamification or the fun included once we're done with coding. So we started about 8 a.m. until noon. And then whoever wants to continue coding or fixing bugs, whatever, can do it. But there will be like a PS3 available for everyone to play if they want Brazil, FIFA Soccer, and a Call of Duty of course. And then we will be playing remotely with them as well. And after that beer. So go out for beer. Let's get out together for some beers. That's what I did. And guys, feel free to raise questions if you want or if you wanna leave to the end as well. But that was the problem about basically trying to get people with some incentive to get off the couch or to get out of their comfort zone and start contributing back. And I mentioned all those challenges before, right? So with those guys supporting, the senior guys supporting the other guys, we try to overcome those challenges one by one. So by having people doing pair programming or sitting down together. So where do I start? Oh, I start here. We're gonna first making sure that everything is installed correctly, Drupal version, Git, everything's working fine in your laptop. So there's a bunch of people that wouldn't produce or wouldn't commit anything until the next round or the next battle, right? There was some introduction time spent first. But it was really good for people to really have some direction. So instead of going by themselves to the old, they would have some support from someone that they know or someone that will spend time with him explaining how to do things, how to generate a patch in Git. Some of them have not worked with Git before. Some of our customers, they don't have Git yet. They still work with SVN or other version control systems. So some developers were not experienced with Git yet. So there was a whole introduction to different things as well as part of the program. So okay, so we investigated first. We did something with, we made a call of action. We create a website, very simple one and start running the programs a Saturday in a month. But then we wanted to make sure that things were really happening and we're getting things out of it, right? So we just wanna, we wanted to make this organic. So we wanna make sure that once we kick it off, things will grow by itself. The whole developers of the community, they will start joining the community more. But still, we still have to be monitoring and supporting this as it grows until we can just leave it with them, right? So we wanted to make sure this is not just sinking down or not continuing. Especially because we just started in April, right? So the results are really good. As I'm gonna be showing you guys, it was so cool to see developers just saying, whoa, that's it, generate a patch and upload over there and make a comment, make sure that I put the status. Yeah, that's it, generate the patch, make sure that it's passing the task. That's it, so there was a bunch of guys that had the impression and never went after to find out more about that was easy, right? So they had the impression that was so difficult. Well, you know what, can't you get back? Yeah, I took a look at the documentation, it's hard. So it was really cool to see their faces when they realized, whoa, it's not that hard, it's easy. And the other side effect or the other things that we've realized that they started to get better already. So this is a long thread here happening, but Kyle, by the time he was publishing his module or actually he wanted to move from Sandbox to a full project, so there was the whole process of review. Does anyone know the whole review process, how it works? Okay, all right.  And there isn't so much reviewers in the community is getting better. So you would imagine that you have to get into a line to aid your module to be reviewed. But if you start helping reviewing as well, you get a bonus, so there's a review bonus. So we've learned by doing it, and that was what this thread was all about. And as Kyle was reviewing the other modules, he got better, he learned some things that already are helping him to do a better code. And as this guy's Closy, and I think there was someone else, two guys was reviewing his project, he was getting better too, and making his module better. And finally, I think they took a couple of weeks, finally they approved, and he's so happy with that. He also, there was an initial impression about how difficult that could be, but once he done it for the first time, he's comfortable about spreading the word throughout the other developers now. So they can also be reviewers and start applying their modules to become full projects. So it was really cool. And Kyle himself, again, we've been discussing, well, we wanted to check it out on me. We can see the website that we've built, we can monitor from there the achievements, but we wanted to see if there's more side effects happening, I mean, are people actually going over there and doing some other things? So what he did, he went to our CINT page on DO. There are all the list of developers that in their profile, they associate the company to the profile. So he scammed through the HTML, get all the user names or user IDs, and start searching around what we're doing, what are those guys doing. So while we could see that, yeah, it's taking effect, things are changing, so we see a lot of commits happening, packs being generated, but still, there's a lot of potential as we can see. But it's good for us to see that things are moving around, and we can establish some targets as an organization to see if we can have more people doing that. So this was really cool too. So we had more contributions in those four months than we did in the past two years. Also lessons learned and impressions, right? So a little bit about, I said it's easy to do things. The other funny thing, and sometimes not so funny, was around dealing with people and the realization of is not a system, like I think Drew said or someone said in the opening session, we're dealing with people on the other side. So although you are interacting with the website and the issue queue, it's actually people on the other side. So there were some funny things happening. There were also not so funny things like people would just, I don't know if they were in a bad mood, would not reply politely in the thread, and that scared away some developers. So yeah, I contributed. I was spending my time contributing back. I was helping him, the owner of the module with the bug fix and he wasn't that polite with me. So that didn't help much, but it was just a realization that I was talking about people on the other side. The guy wasn't in a good mood that day or just, that's how he is. And that's part of the community. And it's just, it's not a system that's over there. So you gotta understand that when dealing with the community too. Very important was to have those sergeants, although he's yelling here, but the idea is to be more like a guide. But we wanted to play around with the levels of the army, right, so sergeants, and as you go, private sergeants and so forth, commander, general, et cetera. But the idea was really important to have some key guys, the senior ones that wouldn't fix so much on that day or work so much, but actually help everyone. So that was very important to have the guys, those guys that are first enthusiasts, they have already some experience either. One of the guys, he didn't have any experience at all with the Drupal community, he was more like into the PHP community and even other ones, Mozilla. But he brought in and he started doing program with those guys. He went by himself and learned things and started doing, I'll fix a bug live for you guys in front of everyone and show to you guys how easy it is. So it was very important to have those sergeants spread out into the room so they could help everyone. So it was really key as well. And the last impression that we had is not as hard as it sounds, right? It was just really a matter of starting. And that was basically what most of the developers they would come and say, yeah, I didn't know it was so easy or I didn't know it wasn't so, I mean it wasn't so hard, right? There's, you gotta learn and once you've been through those steps, things get better. But it's really a matter of go and do it, right? Get off the couch and just do it, don't wait. But it needs a little help as well. A little bit about the future, right? So where, so we established this website. So the website again is very simple. But the whole importance is the program itself, how we are motivating those guys, how we're trying to bring them and contribute back and monitoring and see how things are failing and how things could be done better. So, and also as part of the future, what I want you guys to leave here is how you guys could try and implement something if not just the Drupal letter but also implement something customized for your organization. So I think it was very important to, as an organization, to kick it off but also to maintain, to keep things running, right? So it's still early in the process, just a couple of months. We wanted to do several different things. There's a bunch of ideas happening. We're getting feedback. So for example, we changed, not only on Saturdays, but people now is looking for doing a Thursday night, Thursday night, for example. So I'm still here at work. I want to continue doing that at night. So we're trying to implement twice a month, one Saturday and then a Thursday as well. So we're getting feedback and improving things so we can continue this, to keep this running. The second thing, as the idea, the whole idea originated in the Drupal Con, we realized that this is really important to really get those guys involved. Meaning it's Brazil, the first Drupal Con, it's gonna be in December. So besides some Drupal camps that happens right now over there, Sao Paulo every now and then happens one, but it's not as big as, again, as I see here, as I see in US happening, it's not as big and that's really important. So they can get a feeling of what we're gonna be seeing here this week. So the feature of our program also depends on all the events that we also want to help with them together in Brazil, in South American general. And eventually I wanna reach out to my team in China to make this happen over there. But what's really important and that's something that we need to take away from here as well is to continue fostering those events. Whatever it is, it's key to have those guys involved so they can get the atmosphere, everything that is happening here. So myself, Gilmore and Kai, we had the lucky to be in Denver and get motivated for that and make this happen. But we need to have those developers in Brazil also joining Drupal Con Sao Paulo so they can see what this is about. So this is important for us to continue, as a community to continue creating those programs or those events. I wanted to make a battle specific for core as well. So as we're getting those developers getting better, we want them to focus one of the Saturdays. Let's work on the core, either D7 or D8. So that's part of the call of Drupal, blue drops evolution to start creating battles for that. Like I said, improving some things on the website itself to prevent duplicating information, trying to automate. Again, we don't wanna create a new deal. We just wanna make sure that we can track and give the achievements and still continue to make this fun for them. And something that came as well is to not be something tied to our organization. So while we started discussing maybe as we grow, we could start doing these universities in Brazil in public locations. We could still, we wanted to rely on sponsorship from our company, meaning food and the room. So those are the two basic things that developers asked. Just give me a room, just give me food. Coffee. Coffee as well, of course, in Brazil. And there's a coffee machine. But yeah, I mean, and I asked very, I mean, what do I need to do, the guys? What, as a representative of the organization, what do I need to do to make this happen? And the guy just said, well, just give me a room. Just give me the infrastructure and food and coffee. We'll make things happen. So it's, and once we thought about it, well, we could do something broader. We can go to the cities called Campinas, just one hour away from Sao Paulo. But we could go to the biggest university in Campinas to then go to Sao Paulo and make this something bigger, different groups, et cetera, but and open up the sites to everyone. So right now it's tied to our organization ID. So you can log in, but we wanted to just cut that and open up to everyone. And ideally you could have more organizations joining so we can get sponsored for, we thought about prizes. So if you get to be the leader for a couple months, you get an iPad, you get an iPhone, something that could still motivate them to contribute. And again, trying not to get into the competition mode. So it's a little bit of a challenge. It's more around everyone collaborating. So the developers themselves, they would bring the idea, what if I'm fixing a bug together? So right now our website's not able to track that. So if you fix a program, you fix the bug together, just one guy's gonna get the achievement. So we wanted to work out to give the achievement for both of them. So we can incentivate and foster collaboration, right? So not to become just a game. So that's pretty much what we've done. So basically we went ahead and investigate what was happening, customize and create our call of Drupal Blue Drops program. Forgot to mention we are also putting some stickers across the room promoting in our organization so we can have the work coming out to Argentina and also China. So trying to make this something broader as well within the company. And we're adapting, changing, seeing the results and trying to make things better so the program doesn't die right. It continues running. And also what we've learned in the end is contributing as we know it's like gravity, all it takes a little push. So this whole get out of the couch, is really more about we gotta give them some help push it so they can get out of the comfort zone or get out of their inertia and we start moving on. So that's what I want you guys to take. That if you see developers in your organization or whatever you work with in different groups or you're friends, there is this little push that maybe is needed for everyone to actually get involved. So that's what the main takeaway that we learned. And that's it guys. That's what I wanted to share with you. I don't know if anyone has a question or anything but I was very straightforward, yep. Being part of the Saturday, we're still about 20, 25 people. Yeah, so it's very early but I wanted to be more. So I'm still not happy but out of those, so 300, I'm sorry? How many sergeants? Sardis we have about four or five, yeah. So that's a good average for those 20, 25. What do we want it to have more?  There's a guy in China contributing with translation. So we moved people around as well. So a Brazilian went to China to help train our developers there. So from there he's contributing to translation too. So it doesn't have to be code. So it could be, as you guys know, there's a bunch of things that can help. So we wanted to foster that, but still in the 20, 25, to get, like I said, I'm aiming high. So to get those 300 somehow to get involved, I have to open up the opportunity so not focus so much in modules. There are web designers so they're more focused, their focus is more on themes as well. So we wanted to have battles specific about themes, maybe doing something responsible design and getting what we're learning in our projects and putting those ideas back into the community. So I don't know, ideally, should have 50 people joining us next year, somehow, not in the same day, but somehow participating in the program, yeah. And you're running two, that's a week, that was actually two a month, yeah. So it's one on a Thursday and then a Saturday, yeah. Still trying to get, I mean ideally, if we can get to that point, that'll be awesome. But we're trying. And something that I didn't mention, as I'm building this, again, I'm representing the organization on that area, on that program, as we build this program and start seeing the results and developers getting better, I wanted to actually get to a point where I can do something or we can do something like actually all those guys are doing, all those companies that have developers dedicated for that. I think it's important as well, especially with the amount of developers we have, with the number of sites we've been doing. I think we even being an outsourcing developing company, not being just a Drupal company, but still, as we're leveraging a lot, we wanted to make this happen. So I'm looking to use this to take to my board and start actually finance or having developers dedicated to contribute by getting some of those sergeants to actually be part of the committee more active or have specific time for that. Anyone else? No? Oh. Yeah, I think it's a really great thing. I was to ask, did you ever think about making the system public as well, so that other, for example, my institution could copy this and instead of setting it up ourselves, we could just use the color Drupal that you made also for us. Yeah, I mean, we didn't think about, I don't know, make a distribution or just packaging and putting it over there. We actually, we used the achievements module. We improved that so we can use that module, but whatever we improved, we gave them back as well to the community. We improved the geo support module, so those issues that are, the way we're creating issues and tracking, so you get subscribed once you, something, someone updates that you get notification. So Kyle became a commentator of the geo support module as well. So to answer a question, we haven't created something that you can just start leverage, but I think it's a good idea. What we discussed here is actually to make the site available to anyone. So to some extent, it's something that are looking for, but if you want to create something for your company without using the central version, that's a good idea. Maybe we can just back it up and just here, you can use everything is already, yeah? Definitely. Maybe we can talk later, yeah? So that's a good idea. As far as I know, online gamers tend to gather into clams. This sounds a bit like we should make a German clan or call of Drupal players.  I mean, start having clans and they could help each other or compete against each other. Again, what I wanted to, by bringing this to the session today, to the Drupal call, is bring awareness to what we're doing and getting those ideas and eventually with the support from the EA or other groups or you guys, we can start building on top of it. And again, I'm really concerned about not becoming a competition. Yeah, so if somehow we can keep this healthy in a way, I had the opportunity in the past to go to a Drupal, to a Rails conference. One of the things that I liked over there is that they have the heroes, they have an award for what they call Rails heroes in every conference. So they give away prizes for the guys that contributed the most. I saw something in Drupal in our community, but I don't record exactly what was, but it wasn't that broad. So it's not something that would happen here, for example. So if we could get somehow to that point where we could give prizes, not so much for the guys that are dedicated for that, because that's easy, right?  So I think if we can have somehow a way to incentivate that, that'll be great too. And bring their attention to their names. So people with that side as well, one of the ideas, I'm sure you guys got it, it was really for you to become famous to some extent, right? So people like that somehow. So I think it would be a good idea if we could have like a Drupal contribution award or something in our Drupal conference, and we can leverage this way to monitor who's doing what and who's doing better. It's a good idea. Sure. Do you want like companies throughout the world to create Drupal camps and events during this battle to join the battles in some way? I think it's perfectly feasible, yeah. We could use this website in the Drupal camps. Yeah, there's, as you guys can see, there's nothing, we can use that for any type of sprint and anything because it's just a matter of tracking and giving, there will be discussions around, we discussed quite a lot, I mean, how many points if you create a module you should get to get this achievement. Ah, well, what if it's a difficult bug fixing? Should it be the same level or the same points as a module? So we'll probably get to that point. So it's gonna be a little bit hard to get your consensus, but definitely, I don't see any event that we can get together. And as long as we keep this site simple, to my view, and not duplicate information, so that's why we're working to try to automate the link with the O, the better. So you don't have an extra step for doing that, right? So as much as automation we can do to track that back and count those achievements, the better. But definitely we can use for anything, yeah. But if we got the idea and packaging this, I mean, maybe we should just do it next week, patch it up and put it over there available to anyone, just download it, or we can start putting something more generic out there for any Drupal camp to use. That could be something too, yeah. You focus on the focus that you encounter during the work week, your projects, or as it's completely free, you can do more than whatever you want. So that wasn't one of the main lessons learned for the first time we tried last year. Last year, early 2011, we tried to do something and everyone sat down on a Saturday, and yeah, let's fix bugs in the community. Everyone started looking at each other, what do we do now? It's like, where do I start? So one of the key things here is really to first have a battle theme on that day, so that gives some sense of direction where to start, and also to populate that list of issues. So guys, those are the issues that we created based on your feedback. So the first battle, I myself start getting issues from famous modules, views, whatever, things that I know the developers are working on, so I start populating the site. But then we got this feedback that we could try and do more around what I've been working every day. So start getting exit link at all the bunch of modules that we use every day, because developers will be more comfortable to your point, yeah. So the second battle was more around trying to import those issues for those modules and they could focus on that. But at the same time, if you wanna work out something else, it's up to you, I mean. Man, that's true. So another thing is that most of the time when you are working on a project and you find a bug or something like that, people don't know how to contribute it back. So these events, they learn how to contribute back. So in a database, if you can find something, they now know how to contribute it back because they learn how to do this. Yeah, and the idea is to make it so easy for them as they start doing more and more that they can do it as they fix that in a project throughout the day. Just spend maybe 15 or minutes, half an hour maybe, and make this, the patch over there, make the patch pass the test. And that's it, right, and have someone actually reviewing your patch later. So that's also part of the process. But that's how we've done it. But there is some direction that we gotta give.  So you gotta give some direction. So like the Drupal ladder, as you guys, if you go to the session C, really focus on Drupal 8 core. I don't know exactly if they chose a list of, I don't know, one of the core systems or one particular module within the core. But it's really gotta have some focus so people don't get distracted and get blocked, et cetera. And that helps the sergeants, too. So they have an idea of what they need to focus more. How connected have you been to the people that are working in the Drupal website and have managed the issues, cues? I mean, have you talked to them about that? The Drupal, no, no. I wanted to start with this here today. And for now, I'm gonna be having conversations with them and see how we can, so getting those feedbacks I'm getting here, see how we can bring this. Even if we have to somehow get some of those ideas and be part of the O, somehow, if they like it. So I haven't yet. I was waiting to run a couple of rounds. It's a very brand new program, just a couple of months. I wanted to see how successful it was going so I can really bring it to them. That's my next stop. Because when I saw this, what came to my mind at the beginning was what Staggered Change is doing to Drupal answers a bit. I mean, for sure it's more game-ish than Drupal answers. But I was wondering why it's not part of Drupal or end of the issue cues. I mean, sure, everybody should know if you want your batch to be shown in your profile. Or not, but this type of expertise that is showing in the way you're answering should be part of the O. I agree. I think we just went ahead and we wanted to get our developers kicked off right away, all the spirit of Denver that we got. We just built this website quite fast and started to run and get feedback. So I started over there internally and then putting it out there, instead of maybe reaching out with the ideas to the O. Maybe that's the time I should just go in and bring what we did show, really. So instead of just ideas, I can actually show this running and show the results and cook some ideas together with them. So definitely that's what I wanted to do. One more. You mentioned going to the board with some successes and some history and asking for more funding. You also mentioned the sergeants and presumably you yourself, you know, you said, oh, I have to pop away the issue due to the second battle and so on. That's quite a lot of work managing. I mean, I managed by team and code, right? Really don't get a chance to do coding or just together. Yeah, me too. So my question is, did you do this under the radar or did you, you know, did the organization support you initially or? I did under the radar. So I did it at night. So we did, like, of hours meetings with myself, Gilmore and Kyle initially. Yeah, for this, to kick it off, really, you have to personally invest some time. I'm sorry, but can you give us some tips on how to approach your organization? No, I'll let you know. Next couple of months that I want to build in the case, we're going to Drupal Conson, Paul, which is actually, I'm gonna just leave it out there so you guys don't forget. That'll be great to have you guys there. But yeah, I wanted to have CIT present for that. We wanted to help. Is this right, right? Okay, great. And so by St. Paul, I wanted to leverage this. I wanted to have CIT fostering much more and not only CIT, so we work with two large organizations, pharma companies in the globe. One of them is really eager to contribute back. They don't, they can't use their name as you guys know some companies they can't, but they're very eager to have us. So we might even get support from them to actually do it. So that'll be awesome to have not only my organization, but the customers that we work. Because again, we're not a Drupal only company and there's more to it. And we have to dedicate resource for those organizations, et cetera, et cetera. Not building a product, basically building websites for someone else. A little bit of more challenge for the board, but I wanted to get to the level to have somehow not only food and infrastructure, really have people's time to do it. All right. Okay guys, I'll be around. Feel free if you wanna talk later. I'd really like the ideas so we can discuss more, especially like backing up, opening up to, so we can make this broader and even bringing to the O. Maybe we can all go together with them. That'll be great. And please, somewhere source actually. So there's an excellent talk from Angie. That's the link. And again, the session, the deck is on the website. Should be published by the end of the day, I guess. So there's a good session for her that Inspire does as well, to really about finding the time.  Maybe have to find the time to do it and how easy it is actually once we start doing it. And also the whole thing about Drupal Later. Again, there's the whole documentation. There's the website itself, learndrupal.org. So I really recommend you guys just go take a look and start running those prints. If the case customized like we did, we gotta step back, let's focus on the modules, let's focus on something that you guys are more used to, but eventually let's get to the core to reach out to the targets. That's what we want to be. Thank you very much. Appreciate your time, guys. Hi, and then don't forget to, if you guys can.


Welcome to the first lecture of this course, electronic materials, devices and fabrication. In this course, we will look at semiconductor materials, we will study their properties, mostly the electronic properties. We will then use these semiconductor materials to form devices. So, these devices could be made from two semiconductors, they could be made from a semiconductor and a metal or even a semiconductor, an insulator and a metal. We will also look at devices for some optical applications like say LEDs and solar cells. Finally, we will look at the current micro fabrication industry, where we will form integrated circuits made of these devices from semiconductors. Towards the end of the course, we will also look at some alternate fabrication techniques, where we use a bottom up approach to fabricate devices, rather than the top down approach that is currently followed. When we think of electronic materials, the first property that comes to mind is resistance. Resistance or resistivity, if you will, can be used in order to separate materials into three categories. The first one is conductors, then you have semiconductors and then finally, you have insulators. Since, we will be mostly dealing with metals as conductors, I will also write them as just metals. When we think of resistance, the unit of resistance is ohm and the symbol is omega. Resistance is related to both the voltage and the current by what is known as Ohm's law. Ohm's law states the voltage is nothing but the current times the resistance. Another way of writing it is resistance is voltage over current. The unit of voltage is just Ohm's. The unit of current is ampere. Now, resistance depends upon the dimensions of the sample. So, if you have a thinner material or if you have a wire with a smaller diameter, then the resistance is higher. So, we need to think of a parameter that does not depend upon the dimensions of the sample and this parameter is called resistivity. Resistivity is typically given as rho and it is related to the resistance by where R is the resistance, A is the cross sectional area and L is the length of the sample. The unit of resistivity is Ohm meter. You can also have Ohm centimeter. 1 over the resistivity is called conductivity. The unit of conductivity is nothing but Ohm inverse and meter inverse. So, we have introduced two concepts, right. One is the resistivity, the other is the conductivity. We also said we have three types of materials, conductors, semiconductors and insulators and the difference between them is because of the difference is the resistivity values. So, let us look at some typical values for resistivity for all these three types. Let us start with metals or conductors. In typical examples of metals, copper, gold, platinum, silver, what are some of their typical resistivities? So, rho unit is Ohm meter. In the case of copper, it is 15.7 times 10 to the minus 9. For gold, it is 22.8. 10 to the minus 9 is common for all four. Platinum is slightly higher, it is 98. Silver is actually a better conductor than copper, but silver is also expensive. So, when we look at metals, we have conductivity or we have resistivity of around 10 to the minus 9 Ohm meter. Let us next look at semiconductors. Some examples of semiconductors, germanium, silicon, zinc oxide, gallium arsenide, some of the typical values of resistivity. Silicon is around 0.1 to 10 to the 3. Zinc oxide is 10 to the minus 2 to the minus 4. Slower, gallium arsenide minus 6 to minus 2. In all of these cases, I have given a range of values. The actual resistivity or the conductivity depends upon the impurity level and also the crystal in state, whether you have a single crystal or a poly crystal. So these are some of the values for resistivity in the case of semiconductors. What about insulators? Examples of some typical insulators, you could say wood, water. We say it is deionized water. So there are no dissolved salts, glass and quartz. These are some typical values. So 10 to the 5 in the case of glass, the resistivity is around 10 to the 10, 10 to the 14 depending upon if you have some doping agents in glass or not or some impurities. In case of quartz, it is even higher. So what we essentially see is a wide range of resistivity depending upon whether you are a metal or you have a semiconductor or you have an insulator. So the question is how to understand this difference in these values. In order to do that, we need to look at the band gap of the material and how the band gap evolves. Our focus will be mainly on metals and semiconductors, but whatever concepts we develop, we can equally apply them to insulators. So let us go ahead and look at how band gap evolves starting with a metal. When you have an individual atom, the energy levels are usually sharp and distinct. The question really is what happens when all these atoms come together to form a solid? So let us start with the simplest atom that we know. That is the hydrogen atom. Hydrogen atom has one electron and it has one proton in the nucleus. The one electron is in the vocation and the atomic configuration for hydrogen is 1s1. What happens when we have two hydrogen atoms come together? When we have two hydrogen atoms, you have two 1s atomic orbitals that come together. These interact and give you two molecular orbitals. So your two hydrogen atoms have two atomic orbitals which give you two molecular orbitals. For sake of brevity, I will call atomic orbitals as AO and molecular orbitals as MO. Let us denote these atomic orbitals by the symbol psi of 1s. 1s refers to the fact that you have the electron in the 1s shell. In quantum mechanics, psi represents the wave function of the electron. If you have two hydrogen atoms A and B, you will have two atomic orbitals. Let us call them psi 1sA and psi 1sB. Now in order to form molecular orbitals, these two wave functions psi 1sA and psi 1sB need to be put together and there are two ways of doing it. You could add both of them. This is called a bonding orbital and it is denoted by sigma. You can subtract them and this is called the anti-bonding orbital. In terms of energy, the bonding orbital sigma has a higher energy than the anti-bonding orbital and I am going to denote this as sigma star. So I will call this sigma star. We can also depict this pictorially. So let us take two hydrogen atoms. So at the center, you have the nucleus and outside you have the electron A and B. Each of them has an atomic orbital, so an atomic wave function. So this one is psi 1s of A, which is the atomic orbital for A and psi 1s for B. In both of these cases, I have chosen an exponential function for the atomic orbitals. There is a way of showing that it is actually an exponential function but we would not go into it. As far as we are concerned, we have an orbital that is exponentially decreasing away from the nucleus and we will keep it at that. So now we have two atomic orbitals. We can either add them or subtract them. If you add them, the resultant wave function looks something like this. So you have a minimum between the two atoms and then you have a maximum at the two nucleus. So this is your bonding orbital. We will call it sigma. You can also subtract them, in which case this is the anti-bonding orbital that is sigma star. If you look at it, sigma does not go to 0 at all. It goes to a minimum between the two atoms. On the other hand, sigma star goes to a 0 between the two atoms and this is called a node. So the sigma has zero nodes and the sigma star has one node. So we say that the sigma has a lower energy than sigma star. The bonding orbital is more stable than the anti-bonding. Another way to represent this compactly is to consider your two atomic orbitals A and B. Each has one electron. When these two merge, they form both a bonding and an anti-bonding orbital. So your bonding orbital has a lower energy, that is your sigma. Your anti-bonding orbital has a higher energy, that is sigma star. Each orbital can take two electrons of opposite spin. So both electrons go to the sigma. Thus, when you form a hydrogen molecule from two hydrogen atoms, the overall energy of the system is lower. So it is favorable to form H2 when two hydrogen atoms come together. You can also show this diagram by means of an energy versus bond length diagram. In that particular plot, you will have energy on the y-axis and we will have bond length on the x-axis. So energy is bond length. When the two hydrogen atoms are far apart, typically we say that the hydrogen atoms are at infinity, then what we have is simply the atomic orbitals. So I will show them here, which is the 1S orbital and it has one electron. Then you start to bring your hydrogen atoms together. So as you start to come together, they will see the effect of each other. Ultimately, the atomic orbitals will mix and give you your molecular orbitals sigma and sigma star. So for this, we will have some equilibrium distance. So let me call this equilibrium distance. So it is the equilibrium distance for the two hydrogen atoms in the molecule. So you now have the atoms come together. They form two molecular orbitals. One is sigma. The other is sigma star. So sigma is the lower energy, which is the bonding. Sigma star has a higher energy that is anti-bonding and both electrons go into sigma. So this is the picture as far as hydrogen is concerned. We can use the same diagram to explain why helium 2 will not form. In the case of helium, it is a noble gas. It has two electrons in the 1S shell. If two helium atoms come together, so you have two electrons here. You have two electrons here. Once again, both the 1X, you can think of mixing and forming a bonding and an anti-bonding. So this is your sigma. This is your sigma star. So now we have a total of four electrons. Two electrons will go into sigma, but two electrons also go into the anti-bonding that is sigma star. So the overall energy of helium 2 is higher than just two helium atoms. So that is why you will not have helium 2. This picture is good enough as long as we have two atoms. Now what if I had three hydrogen atoms? Let us look at that. So let us say we have three hydrogen atoms A, B and C. So your atomic orbitals are psi 1S A, psi 1S B, psi 1S C. When we have two atoms, we said they form two molecules. Now when we have three atoms, you are going to get three molecular orbitals. There are three ways of obtaining these molecular orbitals. The first one is to just add all three. This is the lowest energy. You can also do one subtraction. This is the lowest energy. This has the highest energy and then you have one more in between them. So in this particular case, the contribution from the second hydrogen atom is neglected because it is times 0. So all you have is psi 1S A and minus psi 1S C. So let me just write that down.  You can depict this pictorially again by taking three hydrogen atoms. So in the first case, you are adding all three orbitals together. So these are A, B and C. This is psi 1. So you are adding all three. This one, the function does not go to 0 anywhere. So you have zero nodes. In the case of psi 2, we said that the function goes to 0 at atom B. That is why there was only contribution from A and C. This is psi 2. So it has one node. And in the case of psi 3, we have two nodes. So this is the lowest energy with zero nodes. Then you have one node which has a higher energy. Finally, psi 3 that has the highest energy. For this case also, we can draw an energy versus bond length diagram. If we do the energy versus bond length for three hydrogen atoms, what we have are three orbitals, psi 1 with the lowest, psi 3 with the highest and then psi 2 in the middle. Now we have three electrons. Two electrons will go to psi 1 and one electron will go to psi 2. So this is what will happen if you have three hydrogen atoms. Now if you have four hydrogen atoms, you will have four molecular orbitals. You will have four lines here. If you have five, you will have five lines here. So thus, as the number of atoms increases, you will have more lines on your energy versus bond length diagram. So ultimately, we can say, if you have n atoms, it could be n hydrogen atoms, then you will have n molecular orbitals. Each molecular orbital can take two electrons of opposite spin. So 2 times n energy states and the number 2 comes because you can have two electrons of opposite spin. So this is the picture you have developed using hydrogen. We also showed how helium will not form. What if we increase the complexity a bit further and then look at lithium? When we have lithium, lithium has three electrons. So the electronic configuration is 1S2, 2S1. The 1S shell in lithium is an inner shell. So this is an inner shell. The inner shell is usually not involved in bonding. So we would ignore the effect of the inner shell. So what you are interested in is the 2S1 electron. So this again has one electron in the 2S shell. So this is similar to a hydrogen atom. So we can use the same argument for lithium as in the case of hydrogen. So if you have n lithium atoms taking only the 2S electron into account, you will have n atomic orbitals which will give you 2n energy states. Again why 2? Because each energy state or each molecular orbital can have two electrons. Once again, we can draw an energy versus bond length diagram for lithium. So we have energy on the y-axis, bond length on the x-axis. So energy, bond length. Then you have the equilibrium spacing here. This is the equilibrium spacing of the lithium atoms when they come together to form a solid. So you have the 1S2 which is an inner shell. It has two electrons. As I said, the inner shell does not take part in bonding. So it remains a straight line. It does not form a band. Now you have the 2S1. If you have n lithium atoms, the 2S1 of all of those lithium atoms come together to form n molecular orbitals. So once again, we can draw this picture where we will have n lines here. In this particular case, I have drawn 1, 2, 3, 6 lines. So in this particular case, n is 6. The spacing between these lines depend upon n and it also depends on the equilibrium distance. So what is a typical value of n? n is usually a very large number. For example, if we take lithium, lithium has an atomic weight of 7 grams per mole. So if you have 7 grams of lithium, you have 1 mole and 1 mole has 6.023 times 10 to the 23 atoms. This is nothing but the Avogadro number. So your typical value of n, if you had 7 grams of material is approximately 6 times 10 to the 23. So if you have 6 times 10 to the 23 lithium atoms coming together to form a solid, you have 6 times 10 to the 23 molecular orbitals. Each of them can take 2 electrons. So you have 10 times or 12 times 10 to the 23 energy states and this is a really large number. So what this means is the spacing between the individual energy states is really small. If you go back to the diagram, the diagram where we drew here and had n equal to 6 and drew 6 lines, if you have n equal to 23, 10 to the 23, you are essentially drawing 10 to the 23 of these lines. So what I am trying to say is for really large ends, these become continuous and what we have is an energy band. So we can redraw the energy band diagram for lithium taking into fact that you no longer have individual molecular orbitals, but you have an energy band. So in this case, your energy is on the y-axis. We reference an energy level called 0, which is the vacuum level. So let me call this the vacuum level and this has the value 0. So everything can be referenced to the vacuum level. So you have an energy band that is half full. So in this case, these are all the full states and these are all the empty states. So how do we arrive at the fact that the energy band is half full? If you go back to the energy versus the bond length diagrams, energy versus bond length, you have lithium which is 2S1, you have a 1S inner shell, you have 2S1. So this is the energy band here and there are a total of 2N states, but each lithium atom will only contribute one electron. So you have only N electrons. So hence only half of this band is full. So we can erase the top half. So you have a situation where you have half of the band that is full, half of the band that is empty. This is the same thing I have shown here. You have half a band that is full and half a band that is empty. This energy state that separates the full and the empty regions, I have labeled it as EF. EF is called the Fermi energy. Now this is a very important term. The Fermi energy at 0 Kelvin separates the full and empty states. So Fermi energy separates the full and empty states. This is the most often used working definition for Fermi energy. When we come to semiconductors, we will try to modify this definition a little, but as far as you are dealing with metals, we will use this. So let us just put some numbers here. So in the case of lithium, this energy is 0. The Fermi energy is at minus 2.5EV, which means you need 2.5EV of energy in order to excite an electron from the Fermi level to the vacuum level. EB is the bottom of the valence band. In the case of lithium, EB has a value of minus 7.2EV. So the units of energy that I use here EV is called electron volts. EV is called electron volts is related to the energy in joules by the expression 1.6 times 10 to the minus 19 joules. So 1EV is 1.6 times 10 to the minus 19 joules. This is the picture as far as lithium is concerned. So in the case of lithium, you have a 2S shell that is half full. So you also have a band that is half full. What about magnesium or beryllium? So beryllium has an atomic number of 4. So it has an electronic configuration 1S2, 2S2. Magnesium is below beryllium in the periodic table, has an electronic configuration 1S2, 2S2, 2P6 and 3S2. Once again for both of these elements, these are the inner shell. So your outer shell is essentially an S2 configuration. This configuration is the same as in the case of helium. We saw that helium has a 1S2 configuration. So the question is how will beryllium or magnesium form metals or form solid because we know they do and helium does not. The reason is in the case of both beryllium and magnesium, you also have the P shells and the P shells are empty. So here you have a 2P0. In the case of magnesium, you have a 3P0. So what you have when you form a solid is a mixing between the empty 2P0 and the full 2S2. In the case of magnesium, you have a mixing between the empty 3P0 and the full 3S2 and that is the reason why you have an unfilled state and why these are metals. So this once again, we can show this pictorially using the energy versus the bond distance diagram. So let us use the example for beryllium. You have energy on the y-axis and then bond length on the x-axis and we have some equilibrium distance. The 1S shell is an inner shell that will not take part in bonding. You have a 2S2 shell that is full and you have a 2P0 that is empty.  So what you have is a mixing of the 2S and the 2P so that this whole thing which is a mixture of the 2S and the 2P forms a band. Then you can fill in the electrons in this band so that these are all the filled states and these are all the empty states and the energy separating the filled and the empty states is your Fermi energy. So that is the reason why beryllium or magnesium even though they have a full 2S2, electronic configuration are still considered metals because they have mixing between the S and the P so that now they have a band that is half full and half empty. This band which is caused by interaction of the electrons in the outermost shell is called the valence band. It is caused by the interaction between the outer shell electrons. There is also a conduction band. In the case of metals, the valence band and the conduction band are both the same. So in the case of metals, you have both valence and a conduction band and they are both the same. In the case of semiconductors, you will find that the valence and the conduction band are different and there is a gap between them. This is what we call the band gap. So in today's class, we have looked at how metals form. So how you can start with individual atoms and then these atoms come together to form molecular orbitals. The case of metals, you find that these molecular orbitals ultimately form a band and these bands are not completely full. There are always some empty states are available and this is why metals are such good conductors because these electrons which are there in these bands can acquire energy and go to these empty states and thus can move freely within the metal and this makes metals very good conductors. In next class, we will start to look at semiconductors and we will see how we have a band gap in semiconductors. We will also look at different classifications of semiconductor.


share-ripping twenty twenty-two lead pro set multi-sport uh... ten box case number two random it's style type in the hits as we go along with a random at the end to see who's getting what thanks for joining everybody good luck school some fire this stuff is so much fun first case spray see we get here was truly is multi-sport we had tennis iris tennis boxing uh... soccer hockey basketball football and baseball that's that's most of the sports most of them office here nice product though all the cards are in case they are mad this is exactly how he started the last one it's a cal ripken junior auto this time we got a number six of fifteen nice cal and it's just infield's auto ice fields precious and you keep that guys in his football spilling up quickly for tonight and it's style cases three and four break tonight that's at the shop back home it's going to trail and so those seven twenty five now we don't want to shrink this space so we had a bigger for the uh... it's really it's back to the creek you could be it's and do a lot of some times legends lorence taylor harry karstin lorence taylor harry karstin do a lot of sepals also that for daytime guys we've just got to nc football p y t cases left that's all we've got for daytime here and a pretty house auto non-numbered nice prospectus so we got his first woman autos for the coming from in a couple months here spray the house and harling holland auto not number the card there ice-arrowing holland you guys think man city is going to take the uh... premier league title next year with holland and he was pretty good and marcus allen auto one of five marcus allen one of five wow i'd be remember gometto auto huge card non-numbered this stuff is crazy stuff's uh... dig but this auto is color-match on this one and i'd see number of guys three of six three of six on the but this auto and a joel montana auto joel montania it's just getting better you think he's still so underrated it's not isn't eric dickerson auto with the goggles on seventeen twenty full photo there eric dickerson like rendition of a photo and a damey lillard auto very nice damey lillard i'm back there the year for basketball is going to be damey lillard when rice auto seven forty five when rice seven forty five yeah we got a triple auto the nation's all kogan joe montana magic johnson he's hit their good luck on this one montana and magic y'all take a rich a weight box auto weight box a tourney dorsett auto three of five store cents uh... these are stinger this year and then sami sosa auto not number sami sosa and niomi osaka auto not number nice osaka she was in both cases today except it's a cherry west auto four twenty five the osaka outside of uh... outside of serena she'd be the name of women's tennis for sure and tennis in general for twenty five jerry west and a d on sanders d on sanders yeah i was like better an adult joke of it serena osaka d on sanders right let's go ahead go ahead and do the random i guess so we're gonna roll the dice you're randomized names and it is a amount of time some of us i'm a side-by-side it's not what seven times one three four six seven each down to matthew b and seven times on the hits here three four five six seven uh... door set down to hogan montana johnson shane h tony dorsett matthew b erling holland randy marcus allen joe lillard and d on sanders mark l the uh... dick but this tj brady house uh... that's supposed to be hunk u change that before it boasts a cow ripken nick g wade boggs melissa r and aomi osaka marco with justin fields joseph k glenn rice june a erick diggerson joe l joe montana terry west erick k taylor and person do a lot of george m tre lance erick b have even number go met up mark l sammy sosa and matthew p hogan montana and johnson triple the results posted to site thanks to everybody moving on to basketball now


After more than five hours of meeting in Kaduna Governor's of Nigeria's 19th Northern State have decided to say no to the collection of value added tax by states and this is at variance with the resolution of the southern counterparts. The Northern Governor's forum is handing its decision on two stands. One is that the matter is in court. The second is that VAT is not a production tax like excise and but terminal tax paid by the consumer. The Northern State Governor's forum considered the ongoing national debate on collection of value added tax VAT as responsible leaders while we are concerned by the fact that the matter is subject to this. We however for the purposes of educating the public make the following observations. A. The judgment of the federal high court calls to question the constitutionality of VAT withholding tax, education tax, Nigeria Delta Development Commission, National Information Technology Development Agency, 13 percent derivation, National Economic Development Council and many other currently levied and collected by the federal government of Nigeria and the federal inland revenue service. B. Rivers and Lagos state government had enacted their own VAT laws and the southern governor's forum has expressed support for this cause of action. C. VAT is being confused by these state governments as a sales tax. If every state enacted is on VAT law, multiple taxation will result in increase of prices of goods and services and collapse in interstate trade. VAT is not a production tax like excise but terminal tax which is paid by the ultimate consumer. The Northern Governor's are also against the zoning of the presidency to the south. According to them anybody from any region can run and 25 percent of votes cast in two thirds of states should determine the president elect in a runoff. For a power shift to any three political zone in the south with a view to promoting unity and peace in the nation notwithstanding their comments the forum unanimously condemned the statement by the southern governor's forum that the presidency must go to the south. The statement is quite contradictory with the provision of the constitution of the federal republic of Nigeria 1999 as amended that the elected president shall score the majority vote he score at least 25 percent of the votes cast in two thirds states of the federation. C. in the case of runoff simple majority win the election will win the election. Hit the notification button so you get notified about fresh news updates.


With Mike Vrable what you see is exactly what you get. He is tough. He is sarcastic. Okay listen Timmy, we're going like a minute in between plays. So we're gonna have to go a hell of a lot harder than that. He is very funny. He is unafraid. Mike can be grumpy. Yes. Let's go Special Teams jog through. Gunners. You're over there. You're not a gunner. 465 is not gunner material. Go win a job man. But he can also be encouraging. Good ball. Good ball Malik. Oh good ball. He's not easy. That's true but it's not because he is unrealistic. He wants your best. He believes that he can get it out of everyone. 1, 2, 3.