Hi everybody Andrea here. So I wanted to talk to you guys about the difference between xylitol and fluoride and what every patient should know. A lot of patients have heard about fluoride in a dental office. We apply fluoride to your teeth. That's the stuff where you typically have to wait a half an hour before eating, drinking anything because it is protecting your teeth against cavities, against sensitivities. I tell my patients it's like fluoride or sorry it's like vitamins for your teeth. It's amazing. I apply fluoride to my own teeth every six months. Actually every three months usually. I'm a mobile dental hygienist so I have all of my own supplies and materials. I just do it to myself. It's amazing. But then a lot of patients have not heard about xylitol and xylitol and fluoride work hand in hand. So what is xylitol? I might have heard of xylitol being a natural sweetener. But for your teeth, xylitol actually helps to limit the bacteria in your mouth. If there's no bacteria there's no cavities. If there's no bacteria quite often your plaque is a lot less, your tartar is a lot less. So xylitol is actually needed. For a lot of people though your mouth is fairly basic, fairly healthy so you might not need xylitol. But I feel everybody needs sodium fluoride and that can be maintained by using the right toothpaste twice a day and having your teeth cleaned every six months, at least every six months by your dental hygienist who will also apply a fluoride treatment to your teeth. But for those, and this might be you, for those who get cavities at every dental visit, you have so much plaque, so much tartar, you do brush twice a day, you don't understand how this is happening, or maybe you have cold sensitive teeth all the time. You've tried many things but nothing works. That means you also need xylitol added. There are toothpaste out there that have xylitol and sodium fluoride. You also need both. The xylitol helps to limit the bacteria in the mouth, whereas a sodium fluoride helps to actually protect the teeth so you can't get cavities. If there's a cavity in there already it helps to prevent the cavity from getting worse. So do you see how they work hand in hand xylitol preventing the bacteria and the sodium fluoride helps against cavities. They're both amazing, right? But not a lot of people know that and they just kind of brush twice a day. They wonder why they're getting cavities. It's not always as simple as eating less sugar and brushing better. But there's also mouth washes as well. So if you want to do everything you possibly can, use a toothpaste with xylitol and sodium fluoride but also a mouthwash with xylitol and sodium fluoride. If you're a dental hygienist they can kind of show you what toothpaste are out there that have both because I know the toothpaste aisle, the mouthwash aisle can be very overwhelming because you see all these toothpaste. You see all of these mouth washes and to have to look at the back and look at the ingredients is really, really difficult. I can leave some links for you guys down below but keep in mind I'm not being paid for this video so that company is not sponsoring me. This is just my personal opinion and what I recommend to my patients. So if you guys have any questions let me know to do everything you possibly can use a mouthwash and a toothpaste with xylitol and sodium fluoride. And of course you want to brush twice a day. I love to use the water pick to get in between the teeth. You also want to see your dental hygienists at least once every six months. Okay you guys, let me know if any questions and I'll see you guys in the next video.


Key schedule security for the TLS-103 handshake. Let us start with the TLS handshake. The TLS-103 handshake protocol is a key exchange protocol which allows the client and the server to agree on a symmetric key K, which they can then use to build a secure channel to authenticate and encrypt their communication. And I will now focus on the handshake protocol, so let me remove the secure channel. At the core of the TLS-103 handshake protocol is a one-sided authenticated Divi Helman protocol, so the client sends G to the X, the server sends G to the Y, and then additionally the server sends a signature over G to the X and G to the Y, and then both parties authenticate the transcript with a MAC. Additionally, the client and the server might have a pre-shared key, and if so, then the client sends over the ID of this pre-shared key and a binder value that binds the pre-shared key to the transcript. And then the resulting session key should be secure if the PSK was honest or the Divi Helman secret was honest. So how does this work? We first feed the PSK into some deterministic function indicated by this pink error, and then we run an extract function to get a new key value on which we apply the deterministic blue function. And then additionally, using a label and a transcript, we derive the session key. Now the pre-shared key can either come from some external application or it can be a resumption key which was derived in private session. So in addition to the session key, we also derive a resumption key. And in fact, we derive many other keys, but I'll skip these in this overview. So in our security analysis of the TLS 103 key schedule, we model the key schedule, so we model key derivations, not the protocol flow. And the adversary chooses its own corrupted keys and Divi Helman shares, and it can instruct the model to sample honest keys. So this model is a strong version of selective corruption. And additionally, the adversary instructs the model to perform key derivations with adversarily chosen transcripts that have to satisfy some restrictions. And in this model, we prove that the session keys are pseudorandom and unique. Pseudorandomness holds if the last PSK or Divi Helman's secret were honest, and uniqueness also holds for all dishonest keys, which follows from the restrictions on the transcript. In our security analysis, we assume that the expand function is a pseudorandom function, that the extract function is a dual pseudorandom function. And additionally, we assume collision resistant on the expand function, the extract function, and the hash function involved in the protocol. And additionally, what our analysis brought to light was the need for the salted oracle Divi Helman assumption, which is an assumption where the adversary can choose the salt, because here in this protocol, the pink function is a deterministic function of the pre-shared key. So if the pre-shared key is dishonest, then the adversary has a lot of control over the salt that is used in this extraction step here. For the PRF assumptions and the collision resistance, we did not need to make agile assumptions that talk about relations between different algorithms. But for the salted oracle Divi Helman's, we did need to make an agile assumption because potentially from the same Divi Helman secret, one might extract with pre-shared keys that use different algorithms. I would like to conclude my presentation with a couple of afterthoughts on protocol modifications, which would have made the analysis considerably easier and would have allowed us to rely on a weaker oracle Divi Helman assumption. Firstly, it's very nice for the analysis to include the context early, here by context I refer particularly to the resumption level and the Divi Helman shares. Secondly, it would be a good idea to extract from the Divi Helman secret first before mixing it with other secrets. Including the resumption level explicitly early on in the PSK evaluation prevents collision attacks between resumption PSKs and external PSKs more directly than currently done in TLS. Similarly, extracting from Divi Helman first and then including the Divi Helman shares into the derivation allows us to prevent collision attacks for this kind of Divi Helman key. Additionally, it would allow the analysis to rely on a less strong Divi Helman assumption.


This is Think Tech Hawaii, the Trinity Matters here. Seven, hike. We're back, Think Tech, and Think Tech Tech Talks. Here we are on the two o'clock block on a given Wednesday, okay? And we're talking about tech today. I love tech. I'm Jay Fidel. And this is Kalvina Saudia, and she is the solutions architect, a solutions architect of Verizon Wireless right here in Hawaii, Neh. Welcome to the show, Kalvina. Thank you for having me. Yeah. It's Kalvina. Kalvina, thank you. So, you know, Verizon, first Verizon, let me get this straight. Wait a minute. Alexa, what is Verizon? Alexa, what is Verizon? Verizon Communications, otherwise known as Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones industrial average. That's big. That's very big. Yeah. How does it feel to work for a big company like that? It feels great. I've been with them 21 years. Wow, wow. Yeah, I started when I was two. And yeah. That's my line. Right, so I love it. It's a great company. So how did you get into the solutions architect job? Right. So, part of Verizon, a lot of people know Verizon as a phone business, right? You think phones, tablets, you think Verizon. You know, our product really is the network. We're all about the network. And so there's a lot of things you can do on our network. There's a lot of devices and solutions that work off our network. So I'm kind of the solution matchmaker, if you will. So you tell me what your needs are, and I'll help to find a solution that works on our network. Well, I have to tell you, full disclosure, I love Verizon. I've been around the horn on most of them, and I came out for Verizon a long time ago. Never change. And Verizon's fast, and it doesn't drop calls, and it does everything I want. So I like Verizon.  We appreciate your business. Yeah. Thank you very much. Yes, yes. So I'm a Samsung rather than an iPhone guy. But the big news is not Samsung these days. It's iPhone right now. Can you give us the big news on iPhone? Right, so Apple actually recently announced the new iPhone 8, which is available now. And then the 10 that's coming out. So a lot of new things. Apple now, they don't just do one. They're going to do one, and I don't know what happened to nine. Yeah, it happened to nine. Yeah, eight, nine, 10. Unlucky number, I think, isn't it? But eight, we know it's a lucky number for the Chinese. But it strikes me that you have the eight. You have the eight plus. You have the 10 all at the same time, all dropping into the market simultaneously. Isn't that confused the public? You know, people who love Apple, they're always wanting the latest and greatest. And that's what Apple is so great at. They're really great at tweaking what they have to really allow the customer to have a just even a better customer experience. So they are number one in terms of sales. So the question is, what's the difference? I'm going to ask you these compare, contrast questions. What's the difference between the eight and the eight plus? OK, so it's size, mostly size, for the eight and the plus. The functionality is the same? Right. Operating system is the same? Right, it's just a matter of the size. And they both have that stainless steel, what I call a surgical steel case? Right, well, and it's actually, the eight, it's glass. The front and the back are glass. It's the most durable glass ever made on a smartphone. And then the band is that aluminum band that goes around it. Yeah, so it makes it durable because when you think glass, you don't think durability. And of course, we have cases. So we always recommend doing the screen protector, doing the case, putting your accessories. I mean, it's an investment. Yeah, and I drop it and all that. Right, so you want to make sure to protect your investment. Yeah, but if I have the insurance and I always get the insurance, why do I care about the case and the glass? Well, your people like to customize it for them because you see all these pinks, pink's my favorite color. So if the phone is not all pink, then I will make it pink with my accessories. All right, so that's...  You're like, which one's mine? That's true. This could be a real problem, too. It could be, right? Yeah. So what else do they have in terms of functionality, the eight and the eight plus? Right, well, a difference from the seven to the eight, you can kind of compare it that way, the camera. I mean, it's a still a 12 megapixel camera, but the display, you know, it's an HD display and the colors are more vibrant. It just makes for, you know, when you take pictures, right, it's all about the quality of the picture and it's about capturing that moment. Did you know that at Apple, at Apple in terms of design, there are 800 people who work on the camera all the time. I did not know that. Wow. Serious. Right, well, that's why they announce a new phone, right? Because those 800 people, we need to justify what they're doing. Well, you know, from a digital media point of view, I mean, you can get pretty much the same kind of picture from an iPhone or Samsung is also very good. You know, as you can from a lot of cameras and the iPhone just put in your pocket. You know, I find it's very interesting.  But everybody was taking their iPhones into museums and taking pictures. So, you know, I noticed that in the Museum of Modern Art there and in the other museum I went to, they don't care anymore. So you want to take a picture, it's okay, don't use flash, but people are taking pictures and pictures on the walls in these museums like left and right. It's really great to do that. Right, it is, you know, I was in Europe and, you know, we're at the Louvre and we're at these museums and of course you're trying to capture it. The only thing they told us is no selfie sticks because it gets in the way of everyone else's pictures. It does. Yeah, so it has an effect on the experience of that part of the world. Right, but now these cameras, you don't need the flash because the camera is so good, it has low lighting. I mean, it does everything. And so that's why, you know, I'm assuming that's why they allowed it in museums now because you don't need the flash to capture a nice quality picture. Right, and, you know, I think another element here is that people do it anyway because it's so easy, surreptitiously, to take a picture with your iPhone. Right, right. You hold it like that. Click. You just need long arms to get you and the subject matter in there. I have some great pictures from the Museum of Modern Art and San Francisco. Right, very nice, nice. I don't have to buy that, you know, $200 book or anything. Right, exactly, exactly. Or sometimes you just take a picture of the book but you don't have to buy the book. Thank you. Okay, so the eight and the eight plus are going to be similar in terms of functionality. Right. It's just a question of size. It depends on how big a screen you want to have. Right, right. And so what is the functionality? How is it different than the functionality, say, in the seven that would make me want to, you know, take the step? Because the seven wasn't that long ago. Right. I need to be convinced. Right. So, well, besides the camera and the processor is faster. So that's important, you know. Is it effect email speed? I'm sorry? Is it effect email speed? It does, well, email is a couple of things, though. It's not just the processor, it's the network.  Hence, you need to get it on Verizon. Yeah, of course, that's why I do that.  What do you call it, five? The speed five. Oh, five G? Five G. Okay, okay. And five G is supposed to be significantly faster than four G, right? Right, right. And so, do you have any idea? Can you share with us, Kelvina? Well, what I can share with, Verizon's already started building out their five G. So, G just stands for generation. So, it's the fifth generation of network technology. And so, with our fourth generation, that's going to be around for a very, very long time. And that actually is what most mobile customers have. Five G is more of a, how should I say it? So, nowadays, stay in a home or in a business, right? And your cabling only can go, fiber can only go up to maybe the street. So, then now what do you do to take it from the street into the building? That costs a lot of money to run that. So, that's where five G would come in. It's more end to end point. It's a range question. Correct. So, it's fast, but it's really only designed for that last mile, if you will, or last segment. So, it's not the typical mobile user. They'll still be using four G. But what five G allows, that's gonna allow for in building. So, stay in hospitals. And you wanna track where something is going from room to room to room. Five G will allow you to do that. Okay. And so, these phones, you know, set up for five G, in other words, when five G comes to my neighborhood, so to speak, then will they take the five G? No, so these phones are not five G. These phones are four G phones. Is it a convertible thing, or I have to wait till the next day or a minute of time? Correct, correct. The phone has to be built to have that five G technology in it. But like I said, you won't really, a typical user won't really need the five G. Sorry, I'm perfectly happy with four G. Yes, yes. Except if you gave me an option of having faster, I would always take faster. Right, right. But even, you know, within four G, it's like for Verizon, when we built our four G, we're the first to build our four G LT technology, we're a couple of years ahead of the competitors. And we had a certain spectrum. It's basically, think of it like a freeway. Okay, so we built so many lanes. Well, everybody wants to get on those lanes, right? I mean, when you get, like the zipper lane, right? If everybody could get in the zipper lane. Dang it's crowded. Right, they'd rather get on the zipper lane. So that was, everybody was getting on four G. And so what Verizon did is then we bought more lanes. We bought a different spectrum, different frequency. But the phones, you had to choose either one. So then Verizon said, well, why not make, you know, have our equipment be able to run on all the lanes? Because now you have a wider pipe, if you will. So that allows everybody to go fast. I want that, yeah. So not all iPhones, the Verizon iPhone will let you go on all of our LTE frequencies, if you will. But the carriers, not everyone's like that. So speed will be affected by, you know, what network you choose to go on. We're taking a break in a minute, you know. But Kevin, I want to cover one other point with you before we take the break. And that's this, you know, people are giving up landlines by the carload. Everybody's giving them up. I mean, in my house, I'm removing all the, I'm removing all the landlines. I want the boxes there and what, nothing. Because I know that we're not gonna go backward to that. You know, we're moving, we're all moving that way. And that means that this phone that you carry around, this one right here, whatever it is, you know, Samsung iPhone, it's gonna be your main mode of transportation.  This is really interesting because, you know, we need the functionality now because it's gonna do so many things for us. It's a little scary how dependent we are. But here's the thing, you know, I visited your Switch. Have you visited your Switch? Yes, many times. We take a lot of customers on tours of our Switch. We open it up for customers, by the way, to come visit us at our Switch, so. An undisclosed location. Yes, yes. It is a hurricane. If there's a hurricane, I'm at the Switch. Let's just put it down with it. We're gonna have a hurricane one of these days, right?  So how do you prepare your, I love this question. How do you prepare, you know, for the storm? How do you prepare for the aftermath in the storm?  Absolutely, generators. We have generators. We have batteries. We have agreements, you know, contracts to make sure that we're always getting that fuel in there as well. And then we have what we call it a farm. Coats and rats, and it's basically cell on a light truck. That's a coat, you know, a repeater on a truck. Yeah, so that's a rat, you know. So we have different, we call it farm animals for our acronyms, but we're able to roll out generators. We're able to roll out cell sites. Not just when a hurricane comes, but if there's something going on at the stadium, for example, something going on at the convention center. Right, well, we know we're anticipating a high volume of traffic. We're not gonna just say, okay, well, what you get is what you get. We'll make sure that our network can handle the traffic so that customers have a great customer experience. So that's why we're best in Hawaii. Yeah, well. Grated by it for the third year to go.  Of course, the other side of that coin is you have to have batteries so you can, you know, the phone won't go dead. Your phone needs to have, you know, be recharged. Right, right. And you know what happens if you don't recharge it? Yeah, watch this. This is Stink Tech, Hawaii, raising public awareness. A show dedicated to transportation issues and traffic. We identify those areas where we do have problems in the state, but also the show is dedicated to trying to find solutions, not just detail our problems. So join me every other Tuesday on Moving Hawaii Forward. I'm Tim Apacheva. Thank you. I just walked by and I said, what's happening, guys? Okay, Calvena. Yes. I pronounce it right. You got it, right. Saudi Arabia. South here, close. South here. Solution's architect of Verizon, wireless, one of my favorite companies. So, okay. So we talk about the 10 now. Okay. That is, what do you call it? iPhone 10. Right. Preservedly better than the eight and the eight plus. Right. Why do you say that? Right. Well, a couple of different things with the 10. There's not going to be a home button. So that's very different for Apple. How am I going to get used to that? So it's going to be a gestures. There's a facial recognition and gestures. So I'm just making it up, but you can wink and it'll send you a picture. No. But don't wink too hard, you just paid a bill. But so they'll have facial gestures and the no home button. So that's some of the really cool things coming out. So how do I do home? Just wash my hand over it. And does that touch it or just nearby? So nearby, yeah. So it's going to be very fun. I saw a demo of the facial recognition saying that's really something. And it's not just a, you must know more, it's not just a photo of my face. It actually sends out points of light at critical places and they bounce off my face. And that's how it tells it's me. And this makes it harder to cheat on that because that's the identification methodology. So you have to have it sophisticated like that. Does it work? I personally haven't been able to get my hands on one yet. They're, you know, for us employees, we allow the customers to get their phones first. So you get it before I get it. But we do, you know, we'll have them in the stores, of course. When are they coming out exactly? So it's coming out on the third. I'm going to double check it. It's on the third of November. And all three of these phones are coming out on that day? Well, the eight is out already. Already, okay. So we can already, yeah. You can already get your hands on it. And we'll get your hands on it right now. Correct. So the 10 is going to be on the third and we can pre-order it the week prior to that. Okay. So you can start pre-ordering. On the web? Yeah. You can order it. Right. Or you can go into the store. They can help you pre-order it. Or you can talk to one of our business reps. They can help you pre-order it there. So, yeah. I'm really interested in the thing about facial recognition because I think that, you know, it's really a pain, honestly, with my Samsung to go and, you know, make a pattern or enter a password and all that, or worse, not have a pattern or a password and let it stay on all the time.  So you need security, but you also need it to be easy. Right. And this facial thing sounds like a really good idea. Right, right. So it's a way to protect it without touching it. Yeah, right. It's more expensive though. It's $999 and before I walk out to store with a few accessories, I'm talking about real money. Right, right. So there is a cost. However, we do have a trade-in program. So you can trade in any phone. It doesn't even have to be a Verizon phone. It can come from another carrier. We welcome those. How about a junk phone? Really junk phone. The value might not be as much for your trade-in value, but you know, we've seen trade-in values, $390 and up. So you bring in your old phone, the phone you want to trade in, and then Verizon, as long as it's on, it works. And the glasses, it cracked. So that's important. And then we'll go ahead and give you a gift card from Verizon that you can use to apply to purchase the new phone, or you can use it for your bills. So a lot of customers are training it in, and then we can split your payment up. Or make it like an installment contract. Right, right. Can you talk about the differences and the special features that make this? I presume that the pricing on the eight and the eight plus are sort of similar to the pricing on the seven and all that. It's way less than $999. Right, well it's about a $200 difference. So it's about a $200 difference from the eight to the 10. Okay, so it's 800 bucks. Correct. Yes, the eight plus. Right. Yeah, maybe a little less for the eight. Right, right, so, and then versus to the 10. So you're looking at about a $200 difference. Of course there's different sizes in terms of memory. So that's gonna affect your price. But, you know, again, a lot of people are training in their devices. It doesn't have to be an Apple device for an Apple. You can train in a Samsung for an Apple if you want to. You can bring over something else from another carrier. You can, you know, if you have a drawer of phones, you can use that. Why do I want to get the 10 instead of the eight? Why do I want to get a 10 instead of the seven? Why do I want to get the 10 instead of the Samsung eight, which I have now? Right. What's so special about that? Right, right, well, so with the 10, so there's that augmented reality feature too with the camera. So I can take a picture of you and I can put different, just kind of how we're doing here, right, in the studio. I can put different things behind you and, right, kind of augment. Normally when you take a picture, it's just the picture and you have to have a little bit more sophisticated software to be able to change the environment that you're in, change the lighting and all of that. So this will allow you to have that, they call it augmented reality. Yeah, yeah, so you can put a background behind me. It'll identify my image and then change things behind me in any which way, that's pretty good. Correct, yeah. Boy, it's like a great camera you can do. And you can do this on video too, not just the, you know, photograph? Pictures, yeah, so video. I actually, I'm not sure about the video piece of it. I would imagine that so because the technology did this thing. Okay, what else is, what else, you know, impels me, compels me to get the thing. Well, with Apple it's, remember, it's always the camera, it's always about the camera. It's always about that piece of it, you know, what it looks like on the device and the clarity of the picture, just more vibrant, the colors on it. Of course, the home button is big. The facial gestures is really the number one key thing that customers are looking for. How about that? Because without the phone, you actually, the 10 is actually smaller with a bigger screen because you're eliminating the home button. Yeah. Okay, yeah. Now where's the steel? I saw this in the notes here. There's a steel thing, where is it steel? Steel, oh here, surgical grade stainless steel? Right, so just for that durability, right?  And so, and just anything else, right, when you buy a nice camera, right, you want it to last and you wanna take care of it, right? And so, because people take it everywhere now. It's like, people don't even carry their car keys all over the place, but they carry a phone all over the place. And if you lose it, your life is over. Right, you lose your car keys, someone has a spare somewhere, right? Someone has all your family jewels on it. Right, right. Well, but now we can back a lot of things up to the cloud. So, you know, that makes, you know, not just with Apple, I'm talking about, you know, that's one of the other solutions we have for Ryzen. We have a third party that allows you to, you know, become truly wireless and back things up to the cloud. I had this experience a couple of months ago. I must have pushed the wrong button and I wound up resetting my phone, resetting my phone. It's all gone, everything, you know? I was in a state, I'll tell you. I found that most of it was on the cloud and I could pull it down again. That was really saved my bacon. Right, right. So, is the operating system on the 10 the same as the eight? Right, so it'll be, right, so right now, with the operating system though, in terms of the chip, yes, but the operating system is always advancing with Apple, right, so that's a, you know, they're gonna push out different softwares. So, by the time the 10 comes out, hey, you never know, maybe they might come out with a newer software, but we're just really excited. Apple always has fun products, but Samsung has great products, Motorola has great products, Google has great products. I think the eight is probably as far as Samsung is gone right now, I know what else is in the pipeline of them. I was looking at a Pixel, a Google Pixel, and I think their first version, Google One, but then called, what's just called the Google Pixel, was breakable, somebody I know dropped one, and whoa, it was the end of the phone, but now it's, I think it's stronger, maybe it's that glass you're talking about in the case. Right, so the two's out, even Motorola, you know, they have, my husband actually has a Motorola, and the reason he got it is because there's mods that you can put on there, and we have the projector mod, so we just slap it on the back, and now, you know, he's watching a movie, and instead of me trying to go over there and watch it with him, we just project it onto the wall, and we just watch a movie on the wall. It's huge. Which phone is this now? The Motorola, so the mods on sale, right, that projector mod? But you can't get that for the iPhone? No, you can't get that for the iPhone.  Right, so, I mean, you have to use a different device, but this one, you know, Motorola, they just, you just put on different backings on there, and so that's one that we really love using, at home, we're on the go, right, so you're not trying to look at, I mean, you can have a nice phone, but the screen only goes so big, right, and so this allows you to do that, and wireless charging, that's the other thing that's big with Apple as well, so this is the eight. All of these Apple phones are big, you've got a wireless, and the 10 as well. Right, so the charger, Apple's wireless charger hasn't come out yet, but Verizon has a wireless charger, so you plug in that charging pad, and then, boom, you just put that phone right on top, so, different carrier, Samsung has a wireless pad, so, again, we have all the accessories you could want, and I mean, the key really is, you know, like, I'm a solutions architect, I'm the matchmaker, you go into our stores, you talk to our business reps, you tell them what you're looking for, and they'll put you in the right device. So what is the thing that people are most looking for? I'm gonna answer this question for myself. Okay. What would you say that people are looking for more than anything else in these smartphones? In the smartphones? What do you think they're looking for? Okay, so I work a lot with our business customers, and with business customers, it's really about going paperless. That's what I find with business customers. You know, all those check boxes, and the checklist they have, and invoices they have, and all of that, you know, they're giving their employees papers to hand around, they're like, can I see things real-time? I wanna be able to track real-time. I wanna know if a delivery was made. I wanna know if something went wrong.  So we even have programs where we can take that off. Your phone completely. Oh, yeah, security, yeah. So security. Limit the functionality, yeah. Right, really to allow for productivity, getting, it's more becoming a tool now. Yeah, and the company gives it, and controls it, and owns it probably, and so that will, it's a company phone. Right. And that's great, and as a company guy, I wouldn't mind giving that to my staff, and having them use it, and the only app on it is, the only apps on it are the one. But here, I'll tell you what I care about most. Okay, what do you care about? Are you sitting down? Okay. Okay, she's sitting down. Battery life. Battery life. So tell me about the battery life on the 80, and the eight plus and the 10. That's really important to me. Right, so great battery, great battery, but guess what? We also have battery bags in here, or we have accessories to elongate your battery, because it really depends on, battery life is important, but the apps do different, depending on what you do on the phone, some people, they say, hey, my battery's great, but other people might go, I need more battery, because it's really up to the customer on what they're doing. They've got a different taste about this. You wanna know what the number one use of data is? No. Instagram. Instagram. Yeah, yeah. That's a little scary. Of course, it would've been more scary if you said Facebook, yeah. Oh yeah. Nowadays, the younger generations talk about the Snapchat, and whatever else now is coming up. Snapchat is even getting old, but it's the social media. Social media is really what a lot of users do on mobile devices, and so because people are using it for advertisement. It's not just, it's keeping in touch with family, friends, and I mean, that's how I find out about what's going on in the world. It's through social media, right? So people are using their phones for that. You realize that all of this started as recently as 2008, which is eight years ago, and our world has changed, our lives have changed, our way of communicating and living and keeping data. The whole enchilada has changed in eight years, and you're part of it. Wow, I want your job. It's great. You know, when I started with the company, I'm gonna age myself here, but when I started with the company, they installed a car phone into my car.  And I was like, wow, but that was the cool thing, right? When you had an antenna in your car.  And with that in mind, there's a case to be made for getting the latest and greatest every time it comes out. I am into that. Right, well, it helps me keep my job. I want you to keep your job. I want you to come back and talk to me some more. I want you to know more about these phones. That's Kalvina, Saudi Arabia. You're very good. Solution's architect of Verizon Wireless. Thank you so much, Kalvina. Thank you so much for having me, Joe. I appreciate it. Yeah.


So, before we get started, can I ask a question? How many people took the chemistry GRE? G.N. Mark raises his hand. Nobody took the chemistry GRE? How many people are going to graduate school? And you guys didn't take the chemistry GRE? Just the general GRE. Just, I'm just, okay. So, most of you know by now the midterm scores are posted and the key is posted. You can pick up your exam in your discussion section. Stephen and G.N. Mark are going to have those for you. Next time, I'll put the cover sheet on the exam properly and you'll get it back electronically. It takes longer actually. It's not the greatest system right now, but that's the way we'll do it. If you have questions about the grading of your exam, don't be afraid to talk to Stephen and G.N. Mark. Those are the two guys who did the grading. And so, ask them first if you have a question or a conflict about the way your exam was graded, then come and see me. We'll work it out. Quiz Force Friday, and in a moment, I'm going to show you that these quizzes are very important to us. I'm going to show you that in just a second. But let me just tell you I looked very carefully about what's going to be on the quiz and what's going to be on it is the stuff at the beginning of the chapter and chapter 15, sort of the first two-thirds of the chapter, which is all the way through page 496. And if I look at the exercises, the stuff that you need to be able to do is sort of in this range of exercises right here, 15.20 is already stuff for next week. Okay, so these first 19 problems in the exercises, any one of those would be a great quiz question. Okay? Now, this is what the histogram looked like for midterm one. I'm not any happier with it than you are. So if you did better than a 49, you actually did pretty well. I mean, in this class, all right, the mean should be a B. All right, of course, that's not the case when you have a straight scale. These are A's, these are B's, and these are lower grades over here. Okay? So I don't know why it didn't go better than this. One concern I have is that you get in the groove of taking the quizzes with the multiple guests and they're pretty straightforward problems, the sort of plug and chug type problems on the quizzes. I mean, let's face it, because they're pretty short, these quizzes, and then when you get to the exam and it's harder problems that have to be worked out, you're just not used to that, maybe, I don't know. Let me just say, if you think I think this material is easy, you're wrong. I mean, I'm not even a physical chemist by training. I'm an analytical chemist. I don't even know why I got assigned to teach this class. I mean, I have enormous difficulty with this material. If you think all the symbols look the same to you, look the same to me, too.  When I took that trip last week to Kansas, I was sitting on the airplane with my calculator, working out problems. When I got off the airplane, I had about 10 pages of problems. I'm trying to remember how to do this stuff, all right? So you guys, realistically, you know, if I've got 10 pages and I'm teaching the class, I've had this material before, mind you, I mean, it's just been a while, all right? You guys should have 100 pages of notes, 100 pages of problems worked out in your notebooks at a minimum. Wouldn't you agree? So I'm just saying that I don't know that you don't have 100 pages. But if you don't, right, midterm two is three weeks from Friday and it's going to be just like midterm one in terms of length and difficulty. I mean, I don't think midterm one should have been too difficult, all right? Maybe midterm two will be a little bit less difficult, but it's going to be pretty close to midterm one. And so I'm just telling you, in these three weeks, you need to really buckle down. If you haven't done this 100 pages of problems, I'm really suggesting that you focus on doing the hard problems, working them out. I mean, I think you realize that open book doesn't really buy you very much on this type of exam. I mean, if you don't know, if you're not really familiar with the book because you haven't been paging back and through it, working problems, I mean, if you own the book because you've been doing all these problems, then having the book there is pretty helpful, all right? But if you're opening the book and you're like, gosh, I'm trying to find a problem like this one that's been worked out here in the book, you just don't have time for that on this kind of test. I mean, time is really an issue. Okay, so I know this material is hard. It's really hard for me, too. And the only way around that, and we do need to really learn this stuff, the only way to learn it is to do a lot of problems. That's the only way to learn this stuff. I try to make these good lectures, but these lectures are not going to teach you this material. You've got to work the problems. Okay.  This is how you're doing. All right, I calculated this yesterday morning. No quizzes were dropped in the generation of this score. I didn't drop any quizzes, right? So some of you missed quizzes. Some of you did poorly on one or more quizzes. Everybody, virtually everybody would move to the right on this diagram if we dropped two quizzes or even one. Okay, so actually this histogram is a worst case scenario. It would be further to the right if we had dropped quizzes. Okay, so what this means to us is that the quizzes are, in fact, important. All right, they are moving us from a mean in this range over here to a mean in the low B range. And hopefully, by the end of the quarter, this mean is going to move further to the right after we drop these quizzes and we do better on midterm, too. Right, that's the goal. Okay, so that is actually a low B. And we're hoping that this moves over to the mid B range over here somewhere. And I think that's a realistic objective for us. All right, but it's not going to happen on its own. I mean midterm, too, could be just as bad as midterm one. I hope not. All right, help me out here. Okay, so the way I calculated this, in case you're wondering, is I just added your three quizzes together, quizzes are out of five points. I multiplied by eight, because each quiz is in reality worth 40 points. So that would be 120 plus 100 is 220, right? That's where I got this, so this is scaled from zero to one, right? So that would be 100% of the course points. If you've got 5s in all the quizzes and 100 on the midterm, the midterm was actually worth 110 with the extra credit. Why? You'd be over here somewhere. Okay, in case you're wondering how I calculated it. So you, if you want to, you can drop your own quiz, recalculate your, how am I doing score and see where you compare on this diagram. All right, I understand most folks are going to move to the right a little bit. Okay, so we have this guy, Sadie Carnot. He's interested in steam engines and at the time that he's doing his research, steam engines are about 5% efficient. The Carnot limit for a steam engine turns out you can run a steam engine where the steam is at about 300 degrees C and the cold reservoir, it's not room temperature, it's actually the boiling point of water. That's 100 degrees C, okay? And so in principle, you could operate this thing at sort of 65% efficiency. That's the Carnot limit for a steam engine where the steam's at 300 degrees C and the cold reservoir is the boiling point of water, all right? So that really is quite a bit lower than the Carnot limit. So he was asking two questions, could he do better and would changing the fluid from water to something else, could that help? We haven't really addressed that question yet. Okay? So the question is, what limits does nature place on the amount of work that we can derive from this temperature gradient right here, right? Nature doesn't allow us to get an arbitrary amount of work out of this temperature gradient. There are well-defined limits, that's what we're talking about. That's why this is sort of an important subject. So Carnot derived this thing called the Carnot cycle. Turns out he didn't really talk about entropy in his writings, he never used the word entropy and it actually took a second guy to sort through everything that he had done to reformulate it in a way that's useful to us in terms of what we now call the second law of thermodynamics, all right? But he derived this thing called the Carnot cycle which is the most efficient existing cycle cable of converting any given amount of thermal energy to work, he did that and there's another way to look at this, you know, if you inject a certain amount of work into the process of transferring heat from a cold reservoir to a hotter reservoir, why the temperature difference that you're able to generate using a certain amount of work, that's also, it's the same thing, all right? And so in his cycle, we start here on this isotherm and we do an isothermal expansion and then an adiabatic expansion and isothermal compression and then an adiabatic compression. And the reason we care about this, this looks like a completely artificial thing to be focusing so much attention on, all right? I mean, when are we actually in real life going to want to go from here to here or from here to here or from here to here, all right? Why are we going to care about this cycle? Well, the answer turns out to be that any arbitrary cycle like this thing shown in red here, any arbitrary cycle that you care about can be decomposed into a large number of Carnot cycles, all right? This is a diagram from your book. Here's a Carnot cycle right here, all right? Here's another one right next to it right here, all right? I think if you look at these two Carnot cycles, you can see that this one is going this direction, this one's going this direction. And so the two Carnot cycles that share that edge, all right? What's going on at that edge is just going to cancel, all right? And this edge cancels between these two Carnot cycles and this edge cancels between these two Carnot cycles because what that edge represents is the two cycles going along the same path in opposite directions, all right? And what you're left with after you cancel all of these paths here is you're left with the path on the outside of this thing that doesn't cancel, all right? Because there's nothing, there's no Carnot cycle next to it to cancel it out. And so I think you can see that here there's maybe 30 Carnot cycles, all right? And if you made this 3 million, you could map out this red circle pretty accurately with little tiny Carnot cycles, okay? So the point is, is if we understand how one of these cycles works, we can generalize what we learned from one cycle to this infinite number of cycles or a large number of cycles, okay? So any cyclical process like this is constrained by these Carnot considerations, these Carnot efficiencies that we're talking about. This applies to this, that's why we spend so much time studying it, all right? We constantly bump into this Carnot limit in chemistry, okay? So this is what we said, blah, blah, blah, blah, blah, how efficient is the heat engine, the efficiency is the work that we get out of it divided by the heat that's absorbed from the hot reservoir, that's how the efficiency is defined, okay? So in this case, it would be 5 over 20, we said this on Monday and we can derive then an expression for this efficiency which is 1 minus the temperature of the cold reservoir divided by the temperature of the hot reservoir. Where did we get that equation, all right? Can we derive it? So this is just going back to the stuff that we did on Monday, we can prove that this is right and the way that we do that is we write out the work for each of the cycles, cycle, this should not, I don't mean cycle, I mean path, step, step one is the isothermal expansion and step two is the adiabatic expansion, step three is the isothermal contraction, step four is the adiabatic contraction, okay? And we have equations for each one of these terms and it should be obvious to us that these two terms right here are going to cancel because my goodness they're identical except for the ordering of these limits. TC is here, TC is here, all right? And so if I reverse those limits, I'm just going to put a minus sign in front of one of these integrals and they're going to cancel, all right? So I'm only left with these two guys right here and these volume ratios here are related to one another and that's not obvious, all right? But the way that you can tell that they are is this equation right here which is on page 471 of your book, this describes the relationship between the volume at one point on an adiabat and V1 and T1, volume and temperature and the volume and temperature, this is supposed to be four, that's supposed to be four. So I'm talking about this point one and this point four so that's V4, that should be T4, V1, T1, those two points apply to this, okay? So these, because these two points are both on the same adiabat, this ratio has to be satisfied where gamma is Cp over Cv, okay? And the same thing is true here, did I mess this up? Gosh, oh, sorry, no, this is, actually the way I wrote this is fine, right? This is T2, that's this temperature isotherm right here, this is T1, that's this isotherm right here, and these are the two volumes right here, right? So this, actually this is, okay, sorry, so is this, okay? So if I write these two equations and rearrange them, I get this equality right here and this equality right here, one from each one of those equations. And then, if I divide this guy by this guy, the T1's go away, the T2's go away, right? And I'm left with these volume ratios and so I can simplify this into this, all right? And once I've done that, it's obvious that these two logarithmic terms are going to cancel one another, they're the same, okay? So rather than canceling, I can add them, all right? And so I can express them both in terms of V2 and V1 or I could express them both in terms of V3 or V4 if I wanted to, all right? And so this is the expression that I get for the work. Integrated over the whole cycle now, okay? This is the hot reservoir temperature, the cold reservoir temperature in these two volumes, okay? That's the work for the whole cycle, the heat that's transferred in the hot part of the cycle is given by this equation right here, this is just the expression for the isothermal expansion that's occurring in the first step of the cycle, okay? And so the efficiency is just that whole thing divided by that whole thing. According to this equation right here, I just take the total work, divide by the heat that's transferred in the hot part of the cycle, all right, I should get the efficiency. And so when I do that, look, NR is going to cancel when I look at this ratio, right? Log V2 over V1, that's going to cancel, all right? So I'm going to be left with TH minus T over TH and that simplifies right away to that. So we can prove this, we know enough to prove this. Remembering these equations is the hard part but you don't have to remember them, all right? You can look them up, okay? Now, what's the entropy change for each of the four steps of the reversible Carnot cycle? We need a thermodynamic expression for S. Let's say it's this. We'll come back to this later. In other words, the change in the entropy is the change in the heat provided the process is reversible divided by the T that the process is occurring at, all right? Now this reversibility issue, it turns out to be important, that's the reason this is an equal sign, turns out. We'll come to that later, okay? And so if I want to know the delta S for this whole cycle, I can just add up the delta S for these steps. The reason I can do that is because delta S is a state function, okay? And so if I want to know what it is for the whole cycle, I can just add up the delta S for these individual steps and I will get delta S for the whole cycle, all right? Steps 2 and 3, steps 2 and 4, rather, sorry, are adiabatic, right? Step 3 is reversible, isothermal compression, all right? So Q is zero for those two steps, all right? That's why that's zero, all right? The entropy is zero for those adiabatic steps because Q is zero, all right? For the isothermal steps, which are the first one and the third one, all right, these are the entropies, right? Q is not zero, otherwise they'd be adiabatic. And so what can we say about steps 1 and step 3? Well, we can look up Q, all right, for step 1, all right? It's going to be equal to, according to equations that we talked about on Monday and last Wednesday, a week ago, all right? This is the equation that applies to an isothermal change in volume. Hopefully that looks familiar. That was one that you needed for the midterm, all right? What's not totally obvious to me is that Q is equal to minus W, all right, how do we know that this is true? Well, we know that D U equals D Q plus D W, right? We know U doesn't change during any isothermal process, all right? U doesn't change. In other words, the change in U is equal to the constant volume heat capacity. In fact, the constant volume heat capacity is defined as the change in U divided by change in T. That's how the heat capacity is defined. And so the change in U is just the heat capacity times delta T, all right, and it's an isothermal process. Delta T is zero, all right? So we know U's not changing. That means Q's got to equal W. Rather, D Q has got to equal minus D W, right, if U's not changing. So that's why that has to be true. Don't take anything for granted when you're looking at this stuff. I mean, try to prove it to yourself that stuff like this, as simple as that seems, is true. I'm constantly having to do that myself. Okay, so what do we know? Well, we know for step one, V2 is bigger than V1. It's an expansion, right? We're going down that to bigger V. We know W's minus P DV, that's true always, all right?  So delta V is positive, but there's a minus sign, all right? That means Q's got to be positive. If work is negative, Q's got to be positive. In fact, it's got to be the opposite of work. And remember, we're talking about QH. This is the Q at high temperature because we're talking about step one along the top of that isotherm. Okay, and then if you look at this guy, this guy is exactly like this guy except he's happening now at TC, isn't he? And it's a compression, not an expansion. And so, okay, so we've got this equation right here. We've got this equation right here. We're trying to conclude something about this delta S for the whole cycle, the sum of all the four steps. And what we have to remember is that we showed back like 10 slides ago that V2 over V1 equals V3 over V4. And if you make that substitution, these two terms are going to be equal and opposite because check this out. TC is in the numerator. It's going to cancel with TC in the denominator. The same thing with TH, that cancels with that. And so these terms, if that equals that, these two terms are going to be equal to one another, right? Well, that wasn't obvious to me that that had to be true so that's why I went through and added these slides. So that means that this, I mean that's why I had to prove this, that this really is a square box. In other words, the entropy is not changing here or here and the temperature obviously is not changing here and here and so if you make a temperature entropy diagram out of a Carnot cycle, it's a square box. Now, everything that we've said applies to only reversible processes. We've been talking about reversible processes so far.  So what if one or more of these steps are irreversible? The efficiency of irreversible is not, in other words, if the process is irreversible, it's going to be less efficient than a reversible process or at best equal in efficiency, right? Limited, the efficiency of the irreversible process is bounded by, if you will, the efficiency of the reversible process, okay? So what does that mean? Well, it means that if I write the sufficiency in terms of heats, here's the efficiency of the irreversible process here, here's the efficiency of the reversible process here, if it's reversible, now I'm going to write rev on it to make sure that we understand and remember that it's reversible. Okay? So these ones are going to cancel. So we've got this guy right here, all right? And now what you need to remember is that these QCs here, those guys are negative, right? QC and QC reversible are both negative. We showed that back on slide 36. I have no idea what slide this is, 45. How do you know that? Oh, it's down here. Okay, so if I write these Qs as negative, I've got to flip that equality sign around. Here it's greater than, sorry, here it's less than and here it's greater than, right? Greater than or equal to. All right, so if I make these negative, I've got to flip that equality sign around, all right? And these reversible heats can be equated with the temperature of the cold and the hot reservoir, okay? And so if I set this equal to this, I've got to use this greater than or equal to sign. And in other words, if I just cross multiply here, I've got the heat transferred from the cold reservoir divided by its temperature and the heat transferred from the hot reservoir over its temperature and there's a minus sign in front of this guy because it's negative. So for everything that, so this applies to an irreversible process. If I move both of these guys over to the same side, I can put a zero over here and say in general, this has to be true. In other words, if I evaluate these heats from the cold reservoir and the hot reservoir, it's got to be less than or equal to zero. For any irreversible process now or any process, all right? This applies to reversible or irreversible processes because there's an equal sign here. This is called the Clausius inequality. Who's Clausius? All right, so in other words, if I integrate Q over T for a series, you'll recall this is the Q over T that applies for step one. This is Q over T that applies for step three. All right, we've integrated for the whole cycle, all right? So if I integrate over a whole cycle Q over T, that's got to be less than or equal to zero. This is really the most general statement of the Clausius inequality. He's the first German that we've talked about, all right? And what he did is he took Carnot's ideas and translated them into what we now call the second law of thermodynamics. He named entropy and he tried to give it the symbol, you know, good one, but no, sorry, we're going to call it S. I don't know where S, where do you get S out of entropy? Santa? Oh, I don't think so. Now, you can memorialize Clausius with a T-shirt of your own, all right? And you can order this T-shirt online at a website that I will show you, but look at this right here, all right? No, I'm sorry, that was Juul, all right? The energy of the universe is constant, sorry, that wasn't Clausius. So this is totally wrong and I would ask that with me you join in the silent protest by not purchasing one of these $24 T-shirts, yeah, inaccurate and expensive. Okay, so this is the Clausius inequality but the second law of thermodynamics is this, all right? Now, is it obvious to you that this comes from this? Well, it wasn't obvious to me, all right? So let's see if we can figure that out. Now, batteries are dying. Here's how we can show that this is right, all right? State one, state two. We're going to go by some irreversible path between state one and state two and then we're going to go back on a reversible path, all right? Irreversible, reversible, very simple. Now, according to Clausius inequality, these two steps, I can write two terms like this for these two steps. I'm going to go from state one to state two and I'm going to have a DQ over T for that and I'm going to go back from state two to state one except it's going to be reversible and what the Clausius inequality says is, hey, if there are any irreversible steps, that's not the equal sign goes away, all right? See how that's less than or equals to? Equals only applies if everything's reversible, all right? So if this is just this, sorry, this is just going to be less than zero now because of this guy, okay? So since the second step is, so since this is reversible, we know it's equal to DS only because it's reversible, all right? And so I can flip these limits here. If I flip these limits, I think you'll agree I've got to make this plus sign a minus sign, right? And now I can move this guy over to the other side and when I've done that, I just derived this equation right here, all right? So this is the second law of thermodynamics, all right? It says that, well, okay, so what does it say? Look, it makes, it says there's three kinds of processes. First of all, if DS is greater than DQ over T, integrate it over the whole cycle, all right? That cycle can be spontaneous and if it's greater than DQ over T, it's also irreversible, all right? If these two things are equal to one another, it's reversible and if DS is less than DQ over T, it doesn't happen spontaneously. You can make it happen, all right, but it doesn't happen spontaneously. Did it just get yellow again? Oh, what's going on? Okay, if we're talking about an isolated system, an isolated system is one where there's no heat flow and in and out, no mass flow either, okay? And so if I want to understand what these inequalities translate into in an isolated system, I just substitute zero for Q, all right, because there's no heat that can go in and out of the system if it's isolated, okay? And so all of these inequalities just turn into I just substitute zero for this, boom, I get this, okay? So the second law of thermodynamics allows us to classify a process as one that occurs spontaneously or one that doesn't, very important to us as chemists. Okay, what are some examples? Here's some simple examples and this is the kind of problem that's right at the beginning of the exercises from exercise one to exercise 19, all right, if you're going to be looking at the reversible phase transition, vaporization, sublimation, melting, all occur at a particular temperature and with a defined enthalpy, all right, delta H. In this case, the phase transition occurs, if the phase transition occurs reversibly, delta S is equal to delta H over T. So for example, here we have a plot of entropy on this axis and temperature on this axis. We are heating a frozen solid, all right, entropy increases until we get to a phase transition where melting occurs and there's a stepwise increase in the entropy at the melting point, all right, what is that delta S? It's that, all right, if we know the delta H, we just take this temperature, all right, we can calculate what that stepwise increase in entropy is and now we're heating the liquid. The entropy continues to go up, now we get to the boiling point and by golly there's going to be a different delta H that applies there, delta H vaporization, all right, we divide by that temperature, we get that change in the entropy right there, okay, so these stepwise increases in entropy happen as we're heating a solid through these phase transitions, all right, melting and boiling. There could also be reversible heating or cooling of a gas, right, DS is DQ reversible over T, that means the heat capacity can be used to calculate the DQ, multiply that by DT or integrate, divide that by T and we're going to get DS, all right, we use the constant pressure heat capacity if it's a constant pressure process or constant volume heat capacity, if it's a constant volume process, that part's pretty easy, okay, so if I evaluate this integral, all right, it's an integral of 1 over T so I'm going to get log T final over T initial, all right, that's what the delta S is going to be equal to and so S goes up with the logarithm of this ratio, so here's what that looks like, here's delta S plotted against that ratio right there, Tf over Ti, all right, this is a logarithmic increase, these are just different heat capacities, okay, entropy goes up, all right, that's why when you look at this diagram right here, here we're talking about a gas, all right, in principle that's what this is right here, all right, it's the entropy going up for this gas as we heat it, all right, it's happening in accordance with this equation right here, all right, which would predict a logarithmic increase in the entropy with temperature, all right, so we can calculate that very easily, we've got these, we've got this equation right here, we can also talk about the expansion or compression of a gas, right, dQ is minus dw is pdV, so the change in the entropy is just Q over T, again dQ over T rather and in this case it's dQ is pdV and so if the gas is ideal why we can recast that in this form right here, we can just talk about the final and the initial volume and we can use that equation to calculate the change in the volume, so at constant Tv is inversely proportional to p, all right, so I can express this in terms of volume or in terms of pressure, either one, all right, so I can calculate the delta S for that process too, that's another example from the beginning of chapter 15, those exercises, okay, so because S like uses state function you can add da, da, da, multi-brunch, yes, so any random process that you're thinking about, you can break up into steps yourself, you can decompose any process you want into steps, calculate the delta S for those steps, you will always get the right final delta S because it's a state function, it doesn't matter what path you take, right, you will get the same right delta S if you calculate the delta S of each path correctly and add them, calculate the entropy change when argon gas is 25 degrees C in one ATM in a container in volume 100 cubic centimeters is compressed of five cubic centimeters will simultaneously be heated to 45, so we compress the gas, we compress argon and we heat it, okay, we don't have any equation for heating and compressing but we have equations for each one by itself and so we can just heat and then compress, or compress and then heat, add them up, so the total S for this process is just going to be the delta S for compressing plus the delta S for heating, this is process one, we'll call it isothermal compression, we'll do that first, we'll compress first and then we'll heat without changing the volume. Isothermal compression, we expect delta S to be negative for that based on the equations that I just showed you and delta S for the isofolumetric heating, that's going to be positive, remember that's that logarithmic increase, right, entropy goes up logarithmically with temperature, all right, so in this case we don't know if this is going to be a spontaneous transformation or not, we don't know if delta S is going to be positive or negative because we've got one term that's positive, one term that's negative, we don't know which one's bigger, okay, so it's useful to actually think that through and just say, you know, if these were both positive or both negative, you could say, all right, delta S is definitely going to be overall positive or overall negative, okay, so process one is compression to constant temperature, that's this equation right here and all I've done is substituted for the number of moles, I've just substituted PV over RT because I don't know, it doesn't tell me how many moles I've got but I can calculate that from the information I've got here, all right, I can just cancel these Rs, oops, better not, all right, they don't cancel for gosh sakes because I need this to be moles and that is Joules per Kelvin per mole, right, it's different Rs, this one's 0.08206, this one is 8.31451, okay, and if I do the dimensional analysis by Golly, yeah, that's the way I need it to be because I want the units to be Joules per Kelvin, right, be a little careful, okay, so if I plug the numbers in 1 atm, 0.1 liters, 0.08206, 298.15, 8.31451, volumes, boom, boom, boom, minus 0.102 Joules per Kelvin, good, we expected it to be minus, all right, do I have any intuition about the size of this number, zero, I have absolutely no clue if that makes sense, I mean, the fact that it's not 10 of the 20 reassures me a little, all right, so I don't know, now we're going to do step two, all right, that's the equation that we need for step two because we're only changing the temperature at constant volume, that's the heat capacity right there, all right, for an ideal gas which we can expect argon to behave pretty darn ideally, I think you'd agree, we know what that heat capacity is going to be for constant volume, it's 3R over 2, that's the constant volume heat capacity of any ideal gas, that's the number of moles, all right, 3R over 2, yes, units will be yes, we need to multiply by mole, all right, so always think about the units, all right, the units of this heat capacity if they're 3R over 2 are joules per Kelvin per mole, so I've got to multiply by moles to get rid of that because I want the units to be joules per Kelvin, okay, and so that's the same number of moles that we used before, that's the constant volume heat capacity, we know the initial and final temperatures are, yes, yes, yes, yes, yes, yes, yes, yes, yes, Kelvin temperatures and this is the delta S that we calculated, it's a lot smaller, all right, it's positive, we expected it to be positive, okay, and so then the total delta S is just the sum, that's the, what did we do first? Heated, and then we change the volume, right? No, we can, what did we, oh, change the volume for, then we, sorry, yes, all right, okay, and so that's the sum of those two things, minus 0.0987 joules per Kelvin, do I have any clue whether that number makes sense? No, I really don't have any intuition about these entropy changes, all right, but I can say, because that's a minus sign that this is not a spontaneous process, all right, that's what the minus sign tells me, it's not a spontaneous process, and we care about the magnitude too, but the most important thing is to understand that, okay, oh, my goodness, it's exhausting, isn't it, okay, so study for the quiz on Friday, we'll see you then.


We developed a real-time method for detecting and tracking moving objects from unmanned aerial vehicles, UAVs. This method uses a single camera to estimate the camera's motion between two consecutive frames, which is compared to the real optical flow directly calculated from the video feed. This comparison allows us to identify dynamic pixels and group them into dynamic objects. These objects are then tracked over time and space, allowing us to filter out false detections and misdetections. Our algorithm was tested on a quad-rotor platform using a commercial camera, demonstrating its effectiveness. This article was authored by Bruce McDonald, Antonio Barrientos, Jamie Del Cerro, and others.


Well, we're waiting to get ready. Let's get a chance going. Let's do Vermont will fight for immigrant rights. Vermont will fight for immigrant rights. Vermont will fight for immigrant rights. Vermont will fight for immigrant rights. Vermont will fight for immigrant rights. Vermont will fight for immigrant rights. for immigrant rights. We'll long, we'll fight for immigrant rights. We'll long, we'll fight for immigrant rights. We'll long, we'll fight for immigrant rights. So last thing we're going to do is somewhere. So we need Betsy and Brian. If you guys can come up here, please. That'll save us some time for transition once we get moving. Brian's here. Thanks, Brian. All right. So, first of all, we just want to welcome everybody and tell you thank you so much for coming tonight. It is so important that you are here. We're here to send a strong message to Burlington City Council and let them know that we expect them to take a stand for immigrant rights in our city. It's a situation that was limit collaboration between Burlington Police Department and immigration authorities. Burlington, and it's our job to stand up and ask the city council to do the right thing. That's why we're here tonight. It's a agenda that the city council president determined to quote, more time sensitive. Of the city council to get us to go away, to sit down, to be quiet, that that is not the case. Our momentum is here to sign up to speak and use your voice to make a two minute public comment about why this issue is so vital to our community and it cannot wait. It's for public comment. That's right. We're gonna talk about that. Your being here tonight is so important because it's gonna show city council that regardless of whether we're on the agenda tonight, we're here to make sure this issue gets the attention and the time and the space that it deserves at this meeting tonight. We've heard our campaign this group is working on and we need all the support we can get. This is what local grassroots activism looks like and it's how change happens. Thank you everybody for coming out tonight on behalf of BTV Cop Watch. We stand here in solidarity with immigrants who are such a vital part of our community. Here in Burlington, and Chittenden County, and throughout Vermont, it's an anxiety and frustration that people are suffering at the hands of ICE and Border Patrol. Our thoughts are with everyone impacted and I'm hopeful we can find a way to show up for you in a meaningful way moving forward. I'd like to thank the organizers and community voices for immigrant Rice, NoMoth Polymigra and Microdustice for doing the important work of building on Vermont's barren and partial policing policy here in Burlington. I'm hopeful that we can make an impact at some point whenever they take up this vote. The clear message that immigrants are welcome in the community. But I do know that what happens, I do know that it began when I told you about what happens in this building behind me to solve our problem. At the end of the day, we don't have a criminal justice system that's practiced at holding the police accountable for much. We've already seen too many instances of law enforcement agencies apparently disregarding statewide fifth policy. We haven't been able to trust the Vermont State Police. We haven't been able to trust the Chittenden County Sheriff's Office. And I'm not ready to trust the Burlington Police Department. But I do trust us. I trust that we can step up, organize ourselves and get out into the community to provide oversight in real time. We want people to vote and do this work. If you're interested in doing that work and you'd like some company, you can please reach out to myself. And I don't know if anybody else in the crowd is wearing this BTB cop watch hat, but we are on Facebook, we're on Twitter, and we have a training coming up on March 2nd, and which is a great way to get involved. But if filming the police isn't your thing, we would have a lot of stuff for people to do behind the scenes. So if you're interested, please reach out. Thank you all so very much. Yeah, thank you guys. All right. Okay. I'm also pulling me back to Burlington for the last couple of months. I'm really excited to be back in town and hopefully be back in town when they actually present the Vice President of Vermont AFL-CIO, one of the largest labor unions here in Vermont. So, the Vermont AFL-CIO is proud to stand in solidarity with our brothers, sisters, and comrades in the fight for justice, for immigrant workers in our state. We take enormous inspiration from the bravery demonstrated by members of migrant justice who have shown that it is possible to organize and win under the most difficult of circumstances. Ben and Jerry's wouldn't back them up. The farm workers have organized, mobilized, rallied, made noise, and refused to back down. Of all workers, of all backgrounds throughout this state to organize. They have placed before the Burlington City Council no collaboration between the police and ICE. Racial profiling by the police, we need to have to worry that a routine trip to a health clinic or the grocery store will end in deportation. Exactly what this Polynegra collaboration means, the maintenance of a climate of fear aimed at isolating and disempowering immigrant workers. So, welcome in our state and in the labor movement. We recognize that an injury to want is an injury to all. We recognize that a victory against racial profiling and the scapegoating of immigrants is a victory for all workers. We look like. We thank migrant justice for demonstrating that it is possible to fight for dignity and better working conditions. And we pledge our solidarity for this and all other fights of working people standing up for equality, livable wages, and humane working conditions. Obreros unidos, jamás serás vencidos. Yay! Here's United. We'll never be defeated. My name is Rosie Alfaro, and I'm part of the Migrant Justice Coordinating Committee. We're so grateful that all of you are here tonight that we're here together despite the cold and the poor conditions. Thank you for being out here tonight. And we're so grateful that all of you are here tonight that we're here together despite the cold and the poor conditions. Thank you for being out here tonight. And I'm here representing a community that could not be here tonight. Many of them because they are working on farms in this moment. And we're here because we demand that the city of Burlington say no mass poli migra, no more collaboration between police and immigration agents. And so we're calling on the city, we demand that the city pass the no mass poli migra policy so that we no longer live in fear of being detained. We want to be able to leave our homes without the fear, without the terror that an encounter with a police officer will result in our deportation. We want an end to arrest and deportations caused by police. We want to be able to live in peace and without fear. So once more I want to thank each and every one of you for being out here tonight and for being in this struggle together because we know that when we are united we cannot be defeated. Sign up to speak. Now, if you have not done this before or you're unsure about it, we have some things to help you along. When you head in, there are going to be folks in orange vest who are going to show you where to sign up. And if you're not totally sure what to say, we also have talking points that can get you started. But there's no wrong way to speak. We just ask that you speak from your heart, use your voice, remember that the people on the city council represent you and they need to know how you feel about this issue. Also makes a great point, if you are an immigrant or otherwise uncomfortable, you don't need to give your real name. We have the, here we want to say thank you to so much. The people know we're here, we've got energy, they did not be.